89 results on '"Lawrence KM"'
Search Results
2. Increased utilization of the hybrid procedure is not associated with improved early survival for newborns with hypoplastic left heart syndrome: a single-centre experience.
- Author
-
Chen JM, Ittenbach RF, Lawrence KM, Hunt ML, Kaplinski M, Mahle M, Fuller S, Maeda K, Nuri MAK, Gardner MM, Mavroudis CD, Mascio CE, Spray TL, and Gaynor JW
- Subjects
- Humans, Infant, Newborn, Female, Male, Retrospective Studies, Hypoplastic Left Heart Syndrome surgery, Hypoplastic Left Heart Syndrome mortality, Norwood Procedures mortality, Norwood Procedures methods, Norwood Procedures statistics & numerical data, Hospital Mortality trends
- Abstract
Objectives: The primary objectives were to examine utilization of the Hybrid versus the Norwood procedure for patients with hypoplastic left heart syndrome or variants and the impact on hospital mortality. The Hybrid procedure was 1st used at our institution in 2004., Methods: Review of all subjects undergoing the Norwood or Hybrid procedure between 1 January 1984 and 31 December 2022. The study period was divided into 8 eras: era 1, 1984-1988; era 2, 1989-1993; era 3, 1994-1998; era 4, 1999-2003; era 5, 2004-2008; era 6, 2009-2014; era 7, 2015-2018 and era 8, 2019-2022. The primary outcome was in-hospital mortality. Mortality rates were computed using standard binomial proportions with 95% confidence intervals. Rates across eras were compared using an ordered logistic regression model with and adjusted using the Tukey-Kramer post-hoc procedure for multiple comparisons. In the risk-modelling phase, logistic regression models were specified and tested., Results: The Norwood procedure was performed in 1899 subjects, and the Hybrid procedure in 82 subjects. Use of the Hybrid procedure increased in each subsequent era, reaching 30% of subjects in era 8. After adjustment for multiple risk factors, use of the Hybrid procedure was significantly and positively associated with hospital mortality., Conclusions: Despite the increasing use of the Hybrid procedure, overall mortality for the entire cohort has plateaued. After adjustment for risk factors, use of the Hybrid procedure was significantly and positively associated with mortality compared to the Norwood procedure., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)
- Published
- 2024
- Full Text
- View/download PDF
3. The AMDS Stent Reduces Postoperative Distal Anastomotic New Re-Entry (DANE) Tears, But Will It Reduce the Need for Late Aortic Reintervention?
- Author
-
Lawrence KM and Desai N
- Subjects
- Humans, Stents, Aorta surgery, Treatment Outcome, Retrospective Studies, Blood Vessel Prosthesis, Postoperative Complications prevention & control, Postoperative Complications surgery, Blood Vessel Prosthesis Implantation, Aortic Aneurysm, Thoracic surgery, Endovascular Procedures
- Published
- 2024
- Full Text
- View/download PDF
4. Contemporary outcomes of open repair of acute complicated type B aortic dissection.
- Author
-
Lau C, Soletti GJ, Lawrence KM, Rahouma M, Iannacone E, Gambardella I, Gaudino M, and Girardi LN
- Subjects
- Humans, Treatment Outcome, Postoperative Complications, Retrospective Studies, Risk Factors, Risk Assessment, Aortic Aneurysm, Thoracic diagnostic imaging, Aortic Aneurysm, Thoracic surgery, Aortic Aneurysm, Thoracic complications, Blood Vessel Prosthesis Implantation adverse effects, Aneurysm surgery, Aortic Dissection diagnostic imaging, Aortic Dissection surgery, Endovascular Procedures adverse effects
- Abstract
Objective: Open repair of acute complicated type B aortic dissection (ACTBAD), required when endovascular repair is not possible, is historically considered high-risk. We analyze our experience with this high-risk cohort compared with the standard cohort., Methods: We identified consecutive patients undergoing descending thoracic or thoracoabdominal aortic aneurysm (TAAA) repair from 1997 to 2021. Patients with ACTBAD were compared with those having surgery for other reasons. Logistic regression was used to identify associations with major adverse events (MAEs). Five-year survival and competing risk of reintervention were calculated., Results: Of 926 patients, 75 (8.1%) had ACTBAD. Indications included rupture (25/75), malperfusion (11/75), rapid expansion (26/75), recurrent pain (12/75), large aneurysm (5/75), and uncontrolled hypertension (1/75). The incidence of MAEs was similar (13.3% [10/75] vs 13.7% [117/851], P = .99). Operative mortality was 5.3% (4/75) vs 4.8% (41/851) (P = .99). Complications included tracheostomy (8%, 6/75), spinal cord ischemia (4%, 3/75), and new dialysis (2.7%, 2/75). Renal impairment, urgent/emergent operation, forced expiratory volume in 1 second ≤50%, and malperfusion were associated with MAEs, but not ACTBAD (odds ratio: 0.48, 95% confidence interval [CI]: [0.20-1.16], P = .1). At 5 and 10 years, there was no difference in survival (65.8% [95% CI: 54.6-79.2] vs 71.3% [95% CI: 67.9-74.9], P = .42, and 47.3% [95% CI: 34.5-64.7] vs 53.7% [95% CI: 49.3-58.4], P = .29, respectively) or 10-year reintervention (12.5% [95% CI: 4.3-25.3] vs 7.1% [95% CI: 4.7-10.1], P = .17, respectively)., Conclusions: In an experienced center, open repair of ACTBAD can be performed with low rates of operative mortality and morbidity. Outcomes similar to elective repair are achievable even in high-risk patients with ACTBAD. In patients unsuitable for endovascular repair, transfer to a high-volume center experienced in open repair should be considered., (Copyright © 2023 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)
- Published
- 2023
- Full Text
- View/download PDF
5. Noonan syndrome associated with hypoplastic left heart syndrome.
- Author
-
Lawrence KM, Burstein DS, Ahrens-Nicklas R, Gaynor JW, and Nuri MA
- Subjects
- Humans, Mutation, Genetic Association Studies, Phenotype, Noonan Syndrome complications, Noonan Syndrome diagnosis, Noonan Syndrome genetics, Hypoplastic Left Heart Syndrome complications, Hypoplastic Left Heart Syndrome genetics
- Abstract
Noonan syndrome is an inherited disorder caused by alterations in the RAS-MAPK pathway. There have been several identified genotype-phenotype associations made with respect to congenital cardiac lesions and Noonan syndrome variants, but limited data exist regarding single ventricle disease in this population. Here, we report two patients with PTPN11 -related Noonan syndrome and hypoplastic left heart syndrome variants.
- Published
- 2023
- Full Text
- View/download PDF
6. Radiographic and histologic characterisation of white matter injury in a sheep model of CHD.
- Author
-
Lawrence KM, Radaelli E, McGovern PE, Licht DJ, Davey MG, Flake AW, Gaynor JW, and Vossough A
- Subjects
- Sheep, Animals, Humans, Gestational Age, Brain diagnostic imaging, Brain pathology, Fetus pathology, White Matter diagnostic imaging, Brain Injuries
- Abstract
Nearly one in five children with CHD is born with white matter injury that can be recognised on postnatal MRI by the presence of T1 hyperintense lesions. This pattern of white matter injury is known to portend poor neurodevelopmental outcomes, but the exact aetiology and histologic characterisation of these lesions have never been described. A fetal sheep was cannulated at gestational age 110 days onto a pumpless extracorporeal oxygenator via the umbilical vessels and supported in a fluid environment for 14.5 days. The fetus was supported under hypoxic conditions (mean oxygen delivery 16 ml/kg/day) to simulate the in utero conditions of CHD. At necropsy, the brain was fixed, imaged with MRI, and then stained to histologically identify areas of injury. Under hypoxemic in utero conditions, the fetus developed a T1 hyperintense lesion in its right frontal lobe. Histologically, this lesion was characterised by microvascular proliferation and astrocytosis without gliosis. These findings may provide valuable insight into the aetiology of white matter injury in neonates with CHD.
- Published
- 2023
- Full Text
- View/download PDF
7. Genomic and epigenomic responses to aspirin in human colonic organoids.
- Author
-
Witonsky D, Bielski MC, Li J, Lawrence KM, Mendoza IN, Usman H, and Kupfer SS
- Subjects
- Humans, Colon metabolism, Chromatin metabolism, Transcription Factors metabolism, Organoids, Epigenomics, Aspirin metabolism
- Abstract
Aspirin (ASA) is a proven chemoprotective agent for colorectal cancer, though mechanisms underlying these effects are incompletely understood. Human organoids are an ideal system to study genomic and epigenomic host-environment interactions. We use human colonic organoids to profile ASA responses on genome-wide gene expression and chromatin accessibility. Human colonic organoids from one individual were cultured and treated in triplicate with 3 mM ASA or vehicle control (DMSO) for 24 h. Gene expression and chromatin accessibility were measured using RNA- and ATAC-sequencing, respectively. Differentially expressed genes were analyzed using DESeq2. Top genes were validated by qPCR. Gene set enrichment was performed by SetRank. Differentially accessible peaks were analyzed using DiffBind and edgeR. Peak annotation and differential transcription factor motifs were determined by HOMER and diffTF. The results showed robust transcriptional responses to ASA with significant enrichment for fatty acid oxidation and peroxisome proliferator-activated receptor (PPAR) signaling that were validated in independent organoid lines. A large number of differentially accessible chromatin regions were found in response to ASA with significant enrichment for Fos, Jun, and Hnf transcription factor motifs. Integrated analysis of epigenomic and genomic treatment responses highlighted gene regions that could mediate ASA's specific effects in the colon including those involved in chemoprotection and/or toxicity. Assessment of chromatin accessibility and transcriptional responses to ASA yielded new observations about genome-wide effects in the colon facilitated by application of human colonic organoids. This framework can be applied to study colonic ASA responses between individuals and populations in future studies.
- Published
- 2023
- Full Text
- View/download PDF
8. With increasing data, can guidelines continue to overlook the Ross in adults?
- Author
-
Lawrence KM, Courelli V, Tauber K, and Ibrahim M
- Subjects
- Adult, Aortic Valve surgery, Humans, Treatment Outcome, Aortic Valve Insufficiency surgery, Heart Valve Prosthesis Implantation, Pulmonary Valve surgery
- Published
- 2022
- Full Text
- View/download PDF
9. Chronic hypoxemia induces mitochondrial respiratory complex gene expression in the fetal sheep brain.
- Author
-
Moon JK, Lawrence KM, Hunt ML, Davey MG, Flake AW, Licht DJ, Chen JM, Kilbaugh TJ, Gaynor JW, and Beiting DP
- Abstract
Objective: The molecular pathways underlying hypoxemia-induced alterations in neurodevelopment of infants with congenital heart disease have not been delineated. We used transcriptome analysis to investigate differential gene expression induced by hypoxemia in an ovine artificial-womb model., Methods: Mid-gestation fetal sheep (median [interquartile range] 109 [107-112] days' gestation) were cannulated via the umbilical vessels, attached to a pumpless, low-resistance oxygenator circuit, and incubated in a sterile, fluid environment for 22 [21-23] days. Fetuses were maintained with an oxygen delivery of 20-25 mL/kg/min (normoxemia, n = 3) or 14-16 mL/kg/min (hypoxemia, n = 4). Transcriptional profiling by RNA sequencing was carried out on left frontal brains and hypoxemia-regulated genes were identified by differential gene expression analysis., Results: A total of 228 genes whose expression was up or down regulated by ≥1.5-fold (false discovery rate ≤0.05) were identified. The majority of these genes were induced in hypoxemic animals compared to normoxemic controls, and functional enrichment analysis identified respiratory electron transport as a pathway strongly upregulated in the brain during chronic hypoxemia. Further examination of hypoxemia-induced genes showed robust induction of all 7 subunits of the mitochondrial NADH:ubiquinone oxidoreductase (complex I). Other hypoxemia-induced genes included cytochrome B, a component of complex III, and ATP6, ATP8, both of which are components of complex V., Conclusions: Chronic fetal hypoxemia leads to upregulation of multiple mitochondrial respiratory complex genes critical for energy production and reactive oxygen species generation, including complex I. These data provide valuable insight into potential pathways involved in chronic hypoxemia-induced neuropathology and offers potential therapeutic targets for fetal neuroprotection in fetuses with congenital heart defects., (© 2022 The Authors.)
- Published
- 2022
- Full Text
- View/download PDF
10. Urocortin-1 Is Chondroprotective in Response to Acute Cartilage Injury via Modulation of Piezo1.
- Author
-
Jones RC, Lawrence KM, Higgins SM, Richardson SM, and Townsend PA
- Subjects
- Cell Death, Chondrocytes metabolism, Humans, Ion Channels metabolism, Urocortins metabolism, Urocortins pharmacology, Cartilage, Articular metabolism, Osteoarthritis etiology, Osteoarthritis metabolism
- Abstract
Post-traumatic OA (PTOA) is often triggered by injurious, high-impact loading events which result in rapid, excessive chondrocyte cell death and a phenotypic shift in residual cells toward a more catabolic state. As such, the identification of a disease-modifying OA drug (DMOAD) that can protect chondrocytes from death following impact injury, and thereby prevent cartilage degradation and progression to PTOA, would offer a novel intervention. We have previously shown that urocortin-1 (Ucn) is an essential endogenous pro-survival factor that protects chondrocytes from OA-associated pro-apoptotic stimuli. Here, using a drop tower PTOA-induction model, we demonstrate the extent of Ucn's chondroprotective role in cartilage explants exposed to excessive impact load. Using pathway-specific agonists and antagonists, we show that Ucn acts to block load-induced intracellular calcium accumulation through blockade of the non-selective cation channel Piezo1 rather than TRPV4. This protective effect is mediated primarily through the Ucn receptor CRF-R1 rather than CRF-R2. Crucially, we demonstrate that the chondroprotective effect of Ucn is maintained whether it is applied pre-impact or post-impact, highlighting the potential of Ucn as a novel DMOAD for the prevention of injurious impact overload-induced PTOA.
- Published
- 2022
- Full Text
- View/download PDF
11. Chronic foetal hypoxaemia does not cause elevation of serum markers of brain injury.
- Author
-
Omann C, Lawrence KM, Hunt ML, Moon JK, Buchanan J, Licht DJ, Ittenbach RF, McGovern P, Chen JM, Davey M, Hjortdal VE, Flake AW, and Gaynor JW
- Subjects
- Animals, Biomarkers, Female, Fetus, Glial Fibrillary Acidic Protein, Humans, Hypoxia, Oxygen metabolism, Pregnancy, Sheep, Brain Injuries complications, Myelin Basic Protein analysis, Myelin Basic Protein metabolism
- Abstract
Objectives: The objective of this study was to investigate changes in serum biomarkers of acute brain injury, including white matter and astrocyte injury during chronic foetal hypoxaemia. We have previously shown histopathological changes in myelination and neuronal density in fetuses with chronic foetal hypoxaemia at a level consistent with CHD., Methods: Mid-gestation foetal sheep (110 ± 3 days gestation) were cannulated and attached to a pumpless, low-resistance oxygenator circuit, and incubated in a sterile fluid environment mimicking the intrauterine environment. Fetuses were maintained with an oxygen delivery of 20-25 ml/kg/min (normoxemia) or 14-16 ml/kg/min (hypoxaemia). Myelin Basic Protein and Glial Fibrillary Acidic Protein serum levels in the two groups were assessed by ELISA at baseline and at 7, 14, and 21 days of support., Results: Based on overlapping 95% confidence intervals, there were no statistically significant differences in either Myelin Basic Protein or Glial Fibrillary Acidic Protein serum levels between the normoxemic and hypoxemic groups, at any time point. No statistically significant correlations were observed between oxygen delivery and levels of Myelin Basic Protein and Glial Fibrillary Acidic Protein., Conclusion: Chronic foetal hypoxaemia during mid-gestation is not associated with elevated serum levels of acute white matter (Myelin Basic Protein) or astrocyte injury (Glial Fibrillary Acidic Protein), in this model. In conjunction with our previously reported findings, our data support the hypothesis that the brain dysmaturity with impaired myelination found in fetuses with chronic hypoxaemia is caused by disruption of normal developmental pathways rather than by direct cellular injury.
- Published
- 2022
- Full Text
- View/download PDF
12. Contrast-Enhanced Brain Ultrasound Perfusion Metrics in the EXTra-Uterine Environment for Neonatal Development (EXTEND): Correlation With Hemodynamic Parameters.
- Author
-
Lawrence KM, Coons BE, Sridharan A, Davey MG, Flake AW, and Didier RA
- Subjects
- Animals, Brain diagnostic imaging, Contrast Media, Disease Models, Animal, Humans, Perfusion, Sheep, Ultrasonography, Benchmarking, Hemodynamics
- Abstract
Objectives: Contrast-enhanced ultrasound (CEUS) can provide quantitative perfusion metrics and may be useful to detect cerebral pathology in neonates and premature infants, particularly in extrauterine environments. The effect of hemodynamics on cerebral perfusion metrics is unknown, which limits the clinical application of this technology. We aimed to determine associations between systemic hemodynamics and concurrently measured brain perfusion parameters in an animal model of extrauterine support., Methods: Nine fetal lambs were transferred to an extrauterine support device. Lumason® ultrasound contrast (0.1-0.3 ml) was administered via the umbilical vein and 90-second cine clips were obtained. Time-intensity-curves (TICs) were generated and time-dependent and area-under-curve (AUC) parameters were derived. Associations between brain perfusion metrics and hemodynamics including heart rate (HR) and mean arterial pressure (MAP) were evaluated by multilevel linear mixed-effects models., Results: Eighty-six ultrasound examinations were performed and 72 examinations were quantifiable. Time-dependent measurements were independent of all hemodynamic parameters (all p ≥.05). Oxygen delivery and mean blood flow were correlated with AUC measurements (all p ≤.01). Physiologic HR and MAP were not correlated with any measurements (all p ≥.05)., Conclusion: Detected aberrations in time-dependent CEUS measurements are not correlated with hemodynamic parameters and are thought to reflect the changes in cerebral blood flow, thus providing a promising tool for evaluation of brain perfusion. CEUS brain perfusion parameters are not correlated with physiologic HR and MAP, but AUC-dependent measurements are correlated with oxygen delivery and blood flow, suggesting that CEUS offers additional value over standard monitoring. Overall, these findings enhance the applicability of this technology., (© 2021 American Institute of Ultrasound in Medicine.)
- Published
- 2021
- Full Text
- View/download PDF
13. Small Intestinal Levels of the Branched Short-Chain Fatty Acid Isovalerate Are Elevated during Infection with Heligmosomoides polygyrus and Can Promote Helminth Fecundity.
- Author
-
Kennedy MHE, Brosschot TP, Lawrence KM, FitzPatrick RD, Lane JM, Mariene GM, Wasmuth JD, and Reynolds LA
- Subjects
- Animals, Disease Models, Animal, Lipid Metabolism, Mice, Fatty Acids, Volatile metabolism, Host-Parasite Interactions, Intestinal Mucosa metabolism, Intestinal Mucosa parasitology, Nematospiroides dubius physiology, Strongylida Infections metabolism, Strongylida Infections parasitology
- Abstract
Heligmosomoides polygyrus is a helminth which naturally infects mice and is widely used as a laboratory model of chronic small intestinal helminth infection. While it is known that infection with H. polygyrus alters the composition of the host's bacterial microbiota, the functional implications of this alteration are unclear. We investigated the impact of H. polygyrus infection on short-chain fatty acid (SCFA) levels in the mouse intestine and sera. We found that helminth infection resulted in significantly upregulated levels of the branched SCFA isovaleric acid, exclusively in the proximal small intestine, which is the site of H. polygyrus colonization. We next set out to test the hypothesis that elevating local levels of isovaleric acid was a strategy used by H. polygyrus to promote its own fitness within the mammalian host. To test this, we supplemented the drinking water of mice with isovalerate during H. polygyrus infection and examined whether this affected helminth fecundity or chronicity. We did not find that isovaleric acid supplementation affected helminth chronicity; however, we found that it did promote helminth fecundity, as measured by helminth egg output in the feces of mice. Through antibiotic treatment of helminth-infected mice, we found that the bacterial microbiota was required in order to support elevated levels of isovaleric acid in the proximal small intestine during helminth infection. Overall, our data reveal that during H. polygyrus infection there is a microbiota-dependent localized increase in the production of isovaleric acid in the proximal small intestine and that this supports helminth fecundity in the murine host.
- Published
- 2021
- Full Text
- View/download PDF
14. Attrition between the superior cavopulmonary connection and the Fontan procedure in hypoplastic left heart syndrome.
- Author
-
Lawrence KM, Ittenbach RF, Hunt ML, Kaplinski M, Ravishankar C, Rychik J, Steven JM, Fuller SM, Nicolson SC, Gaynor JW, Spray TL, and Mascio CE
- Subjects
- Age Factors, Female, Heart Transplantation, Humans, Hypoplastic Left Heart Syndrome diagnostic imaging, Hypoplastic Left Heart Syndrome mortality, Hypoplastic Left Heart Syndrome physiopathology, Infant, Male, Retrospective Studies, Risk Assessment, Risk Factors, Time Factors, Treatment Outcome, Fontan Procedure adverse effects, Fontan Procedure mortality, Heart Bypass, Right adverse effects, Heart Bypass, Right mortality, Hypoplastic Left Heart Syndrome surgery
- Abstract
Objective: We investigated the incidence and predictors of failure to undergo the Fontan in children with hypoplastic left heart syndrome who survived superior cavopulmonary connection., Methods: The cohort consists of all patients with hypoplastic left heart syndrome who survived to hospital discharge after superior cavopulmonary connection between 1988 and 2017. The primary outcome was attrition, which was defined as death, nonsuitability for the Fontan, or cardiac transplantation before the Fontan. Subjects were excluded if they were awaiting the Fontan, were lost to follow-up, or underwent biventricular repair. The study period was divided into 4 eras based on changes in operative or medical management. Attrition was estimated with 95% confidence intervals, and predictors were identified using adjusted, logistic regression models., Results: Of the 856 hospital survivors after superior cavopulmonary connection, 52 died, 7 were deemed unsuitable for Fontan, and 12 underwent or were awaiting heart transplant. Overall attrition was 8.3% (71/856). Attrition rate did not change significantly across eras. A best-fitting multiple logistic regression model was used, adjusting for superior cavopulmonary connection year and other influential covariates: right ventricle to pulmonary artery shunt at Norwood (P < .01), total support time at superior cavopulmonary connection (P < .01), atrioventricular valve reconstruction at superior cavopulmonary connection (P = .02), performance of other procedures at superior cavopulmonary connection (P = .01), and length of stay after superior cavopulmonary connection (P < .01)., Conclusions: In this study spanning more than 3 decades, 8.3% of children with hypoplastic left heart syndrome failed to undergo the Fontan after superior cavopulmonary connection. This attrition rate has not decreased over 30 years. Use of a right ventricle to pulmonary artery shunt at the Norwood procedure was associated with increased attrition., (Copyright © 2020. Published by Elsevier Inc.)
- Published
- 2021
- Full Text
- View/download PDF
15. Genomic and epigenomic active vitamin D responses in human colonic organoids.
- Author
-
Li J, Witonsky D, Sprague E, Alleyne D, Bielski MC, Lawrence KM, and Kupfer SS
- Subjects
- Chromatin drug effects, Chromatin genetics, Chromatin metabolism, Chromatin Immunoprecipitation Sequencing methods, Humans, Male, Middle Aged, RNA-Seq methods, Time Factors, Transcriptional Activation, Vitamin D3 24-Hydroxylase genetics, Vitamins pharmacology, Calcitriol pharmacology, Colon metabolism, Epigenomics methods, Genomics methods, Organoids metabolism, Transcriptome drug effects
- Abstract
Active vitamin D, 1α,25(OH)
2 D3 , is a nuclear hormone with roles in colonic homeostasis and carcinogenesis; yet, mechanisms underlying these effects are incompletely understood. Human organoids are an ideal system to study genomic and epigenomic host-environment interactions. Here, we use human colonic organoids to measure 1α,25(OH)2 D3 responses on genome-wide gene expression and chromatin accessibility over time. Human colonic organoids were cultured and treated in triplicate with 100 nM 1α,25(OH)2 D3 or vehicle control for 4 h and 18 h for chromatin accessibility, and 6 h and 24 h for gene expression. ATAC- and RNA-sequencing were performed. Differentially accessible peaks were analyzed using DiffBind and edgeR; differentially expressed genes were analyzed using DESeq2. Motif enrichment was determined using HOMER. At 6 h and 24 h, 2,870 and 2,721 differentially expressed genes, respectively (false discovery rate, FDR < 5%), were identified with overall stronger responses with 1α,25(OH)2 D3 . Similarly, 1α,25(OH)2 D3 treatment led to stronger chromatin accessibility especially at 4 h. The vitamin D receptor (VDR) motif was strongly enriched among accessible chromatin peaks with 1α,25(OH)2 D3 treatment accounting for 30.5% and 11% of target sequences at 4 h and 18 h, respectively (FDR < 1%). A number of genes such as CYP24A1, FGF19, MYC, FOS , and TGFBR2 showed significant transcriptional and chromatin accessibility responses to 1α,25(OH)2 D3 treatment with accessible chromatin located distant from promoters for some gene regions. Assessment of chromatin accessibility and transcriptional responses to 1α,25(OH)2 D3 yielded new observations about vitamin D genome-wide effects in the colon facilitated by application of human colonic organoids. This framework can be applied to study host-environment interactions between individuals and populations in the future.- Published
- 2021
- Full Text
- View/download PDF
16. Off-Pump Explant of a Left Ventricular Assist Device Using a Recovery Plug in a Pediatric Patient.
- Author
-
Geoffrion TR, Lawrence KM, O'Connor MJ, and Chen JM
- Subjects
- Adolescent, Echocardiography, Heart Failure diagnosis, Heart Failure physiopathology, Heart Ventricles diagnostic imaging, Humans, Magnetic Resonance Imaging, Cine methods, Male, Device Removal methods, Heart Failure surgery, Heart Ventricles surgery, Heart-Assist Devices adverse effects, Recovery of Function
- Abstract
Though the numbers remain small, the use of continuous-flow left ventricular assist devices as a bridge to recovery in pediatric patients has been increasing. Select patients may have sufficient myocardial recovery to allow for device removal. Here, we describe a 13-year old requiring left ventricular assist device implantation for myocarditis who was referred for explant of the device after recovery. This was performed via thoracotomy, without cardiopulmonary bypass, using a newly developed titanium recovery plug that is custom designed to fit the HeartMate 3., (Copyright © 2021 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)
- Published
- 2021
- Full Text
- View/download PDF
17. Erratum to 'Cathepsin K inhibitors prevent matrix-derived growth factor degradation by human osteoclasts'.
- Author
-
Fuller K, Lawrence KM, Ross JL, Grabowska UB, Shiroo M, Samuelsson B, and Chambers TJ
- Published
- 2021
- Full Text
- View/download PDF
18. Impaired host resistance to Salmonella during helminth co-infection is restored by anthelmintic treatment prior to bacterial challenge.
- Author
-
Brosschot TP, Lawrence KM, Moeller BE, Kennedy MHE, FitzPatrick RD, Gauthier CM, Shin D, Gatti DM, Conway KME, and Reynolds LA
- Subjects
- Animals, Disease Models, Animal, Female, Gastrointestinal Microbiome, Intestines microbiology, Intestines parasitology, Male, Mice, Mice, Inbred BALB C, Mice, Inbred C57BL, Salmonella Infections complications, Salmonella typhi, Coinfection microbiology, Coinfection parasitology, Disease Resistance physiology, Helminthiasis complications, Intestinal Diseases, Parasitic complications, Nematospiroides dubius physiology, Salmonella physiology
- Abstract
Intestinal helminth infection can impair host resistance to co-infection with enteric bacterial pathogens. However, it is not known whether helminth drug-clearance can restore host resistance to bacterial infection. Using a mouse helminth-Salmonella co-infection system, we show that anthelmintic treatment prior to Salmonella challenge is sufficient to restore host resistance to Salmonella. The presence of the small intestine-dwelling helminth Heligmosomoides polygyrus at the point of Salmonella infection supports the initial establishment of Salmonella in the small intestinal lumen. Interestingly, if helminth drug-clearance is delayed until Salmonella has already established in the small intestinal lumen, anthelmintic treatment does not result in complete clearance of Salmonella. This suggests that while the presence of helminths supports initial Salmonella colonization, helminths are dispensable for Salmonella persistence in the host small intestine. These data contribute to the mechanistic understanding of how an ongoing or prior helminth infection can affect pathogenic bacterial colonization and persistence in the mammalian intestine., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2021
- Full Text
- View/download PDF
19. Fetoscopic insufflation modeled in the extrauterine environment for neonatal development (EXTEND): Fetoscopic insufflation is safe for the fetus.
- Author
-
Coons BE, Lawrence KM, Didier R, Sridharan A, Moon JK, Rossidis AC, Baumgarten HD, Kim AG, Mejaddam AY, Ozawa K, De Bie F, Davey M, and Flake AW
- Subjects
- Animals, Carbon Dioxide administration & dosage, Female, Fetus surgery, Pregnancy, Sheep, Fetal Diseases surgery, Fetoscopy, Insufflation, Meningomyelocele surgery
- Abstract
Background: Minimally invasive fetal surgery, or fetoscopy, is an alternative to open fetal surgery to repair common birth defects like myelomeningocele. Although this hysterotomy-sparing approach reduces maternal morbidity, the effects of in utero insufflation on the fetus are poorly understood. Our purpose was to determine the optimal fetal insufflation conditions., Methods: Fetal sheep at gestational age 104 to 107 days were studied under insufflation conditions in utero and ex utero. The ex utero fetuses were cannulated via their umbilical vessels into a support device, the EXTra-uterine Environment for Neonatal Development (EXTEND). EXTEND fetuses were exposed to four different insufflation conditions for four hours: untreated carbon dioxide (CO
2 ) (n=5), warm humidified (whCO2 ) (n=4), whCO2 with the umbilical cord exposed (n=3), and whCO2 without amniotic fluid (skin and cord exposed) (n=3)., Results: In utero insufflation led to significant increases in fetal CO2 and reductions in fetal pH. Ex utero insufflation with whCO2 did not lead to changes in fetal blood gas measurements or cerebral perfusion parameters. Insufflation with whCO2 with an exposed umbilical cord led to reduced umbilical blood flow., Conclusions: Insufflation with warm humidified CO2 with an amniotic fluid covered umbilical cord is well tolerated by the fetus without significant changes in hemodynamics or cerebral perfusion parameters., Type of Study: Basic science LEVEL OF EVIDENCE: N/A., (Copyright © 2020. Published by Elsevier Inc.)- Published
- 2021
- Full Text
- View/download PDF
20. Quantitative contrast-enhanced ultrasound of the brain on twin fetal lambs maintained by the extrauterine environment for neonatal development (EXTEND): initial experience.
- Author
-
Sridharan A, Lawrence KM, Martin-Saavedra JS, Davey MG, Flake AW, and Didier RA
- Subjects
- Animals, Brain diagnostic imaging, Female, Gestational Age, Humans, Sheep, Ultrasonography, Contrast Media, Fetus
- Abstract
Background: With the development of an artificial environment to support the extremely premature infant, advanced imaging techniques tested in this extrauterine system might be beneficial to evaluate the fetal brain., Objective: We evaluated the feasibility of (a) performing contrast-enhanced ultrasound (CEUS) and (b) quantifying normal and decreased brain perfusion in fetal lambs maintained on the extrauterine environment for neonatal development (EXTEND) system., Materials and Methods: Twin premature fetal lambs (102 days of gestational age) were transferred to the EXTEND system. Twin B was subjected to sub-physiological flows (152 mL/kg/min) and oxygen delivery (15.9 mL/kg/min), while Twin A was maintained at physiological levels. We administered Lumason contrast agent into the oxygenator circuit and performed serial CEUS examinations. We quantified perfusion parameters and generated parametric maps. We also recorded hemodynamic parameters, serum blood analysis, and measurements across the oxygenator. Postmortem MRIs were performed., Results: No significant changes in hemodynamic variables were attributable to CEUS examinations. On gray-scale images, Twin B demonstrated ventriculomegaly and progressive parenchymal volume loss culminating in hydranencephaly. By CEUS, Twin B demonstrated decreased peak enhancement and decreased overall parenchymal perfusion when compared to Twin A by perfusion parameters and parametric maps. Changes in perfusion parameters were detected immediately following blood transfusion. Postmortem MRI confirmed ultrasonographic findings in Twin B., Conclusion: In this preliminary experience, we show that CEUS of the brain is feasible in fetal lambs maintained on the EXTEND system and that changes in perfusion can be quantified, which is promising for the application of CEUS in this extrauterine system supporting the premature infant.
- Published
- 2021
- Full Text
- View/download PDF
21. Littermate-Controlled Experiments Reveal Eosinophils Are Not Essential for Maintaining Steady-State IgA and Demonstrate the Influence of Rearing Conditions on Antibody Phenotypes in Eosinophil-Deficient Mice.
- Author
-
FitzPatrick RD, Kennedy MHE, Lawrence KM, Gauthier CM, Moeller BE, Robinson AN, and Reynolds LA
- Subjects
- Animals, Biomarkers, Cytokines metabolism, Flow Cytometry, Immunoglobulin A blood, Immunoglobulin A, Secretory immunology, Mice, Mucous Membrane immunology, Mucous Membrane metabolism, Plasma Cells immunology, Plasma Cells metabolism, Eosinophils immunology, Eosinophils metabolism, Immunoglobulin A immunology
- Abstract
Conflicting data has emerged regarding a role for eosinophils in IgA production, with some reports that eosinophils support both secretory and circulating IgA levels during homeostasis. Previous studies have compared antibody levels between wildtype and eosinophil-deficient mice, but these mice were obtained from different commercial vendors and/or were not littermates. Thus, the possibility remains that extrinsic environmental factors, rather than an intrinsic lack of eosinophils, are responsible for the reports of reduced IgA in eosinophil-deficient mice. Here we used wild-type and eosinophil-deficient (ΔdblGATA) mice that were purchased from a single vendor, subsequently bred in-house and either co-housed as adults, co-reared from birth or raised as littermates. We found no differences in the levels of secretory IgA or in the numbers of small intestinal IgA-producing plasma cells between wild-type and ΔdblGATA mice, demonstrating that under controlled steady-state conditions eosinophils are not essential for the maintenance of secretory IgA in the intestinal tract. While we found that levels of IgM and IgE were significantly elevated in the serum of ΔdblGATA mice compared to co-reared or co-housed wild-type mice, no significant differences in these or other circulating antibody isotypes were identified between genotypes in littermate-controlled experiments. Our results demonstrate that eosinophils are not required to maintain secretory or circulating IgA production and the absence of eosinophils does not impact circulating IgG1, IgG2b, IgM, or IgE levels during homeostasis. These findings emphasize the importance of optimally controlling rearing and housing conditions throughout life between mice of different genotypes., (Copyright © 2020 FitzPatrick, Kennedy, Lawrence, Gauthier, Moeller, Robinson and Reynolds.)
- Published
- 2020
- Full Text
- View/download PDF
22. The Effects of Nitric Oxide in Oxygenator Sweep Gas During Extracorporeal Circulation in a Neonatal Ovine Model.
- Author
-
Rossidis AC, Lawrence KM, Mejaddam AY, Kim AG, Baumgarten HD, Coons BE, Young K, Monos S, Hwang G, Flake AW, and Davey MG
- Subjects
- Animals, Animals, Newborn, Disease Models, Animal, Platelet Count, Sheep, Blood Platelets drug effects, Extracorporeal Membrane Oxygenation methods, Nitric Oxide pharmacology, Platelet Activation drug effects
- Abstract
Extracorporeal membrane oxygenation is a life-saving intervention, but bleeding complications are frequent. Given that the combination of platelet loss and dysfunction is a major contributor to this acquired bleeding diathesis, efforts to combat these phenomena are of great clinical importance. In this study, we investigated the effects of nitric oxide (NO) added to the sweep gas of an extracorporeal circuit in a neonatal ovine model. Eight lambs (age 9.6 ± 1.9 days) were cannulated via the neck vessels and maintained on a pumpless arteriovenous extracorporeal membrane oxygenation circuit with blood flow restricted to 100 ml/min for 72 hours. All animals were heparinized, and a subset (n = 4) also received NO in the sweep gas at a concentration of 200 ppm. We observed no adverse effects from NO administration, and methemoglobin levels remained unchanged. Platelet counts significantly declined in all animals over the course of the study; however, mean counts were higher in the NO-treated group, and this difference was statistically significant at 24 hours (62 ± 3% vs. 32 ± 7% of baseline, P < 0.01). Likewise, mean plasma levels of beta-thromboglobulin, a marker of platelet activation, were lower in the NO-treated group, and this difference was also significant at the 24 hour time point (9.5 ± 2.2 vs. 19.7 ± 6.5 pg/mL/10 platelets, P < 0.05). We conclude that 200 ppm NO can be safely blended into the oxygenator sweep gas of a low-flow extracorporeal circuit and that it may transiently attenuate platelet consumption and activation.
- Published
- 2020
- Full Text
- View/download PDF
23. Inhaled Nitric Oxide Is Associated with Improved Oxygenation in a Subpopulation of Infants with Congenital Diaphragmatic Hernia and Pulmonary Hypertension.
- Author
-
Lawrence KM, Monos S, Adams S, Herkert L, Peranteau WH, Munson DA, Hopper RK, Avitabile CM, Rintoul NE, and Hedrick HL
- Subjects
- Administration, Inhalation, Female, Hernias, Diaphragmatic, Congenital complications, Humans, Hypertension, Pulmonary complications, Infant, Male, Retrospective Studies, Treatment Outcome, Hernias, Diaphragmatic, Congenital drug therapy, Hypertension, Pulmonary drug therapy, Nitric Oxide administration & dosage, Oxygen metabolism
- Abstract
Objectives: To determine which patients with congenital diaphragmatic hernia (CDH) and pulmonary hypertension (PH) benefit from inhaled nitric oxide (iNO) treatment by comparing characteristics and outcomes of iNO responders to nonresponders., Study Design: We performed a retrospective chart review of infants with CDH treated at our center between 2011 and 2016. In a subset of patients, iNO was initiated for hypoxemia or echocardiographic evidence of extrapulmonary right to left shunting. Initial post-treatment blood gases were reviewed, and patients were classified as responders (increased PaO
2 >20 mm Hg) or nonresponders. Baseline characteristics, echocardiograms and outcomes were compared between groups with Fisher exact tests and Mann-Whitney t tests, as appropriate., Results: During the study period, 95 of 131 patients with CDH (73%) were treated with iNO. All patients with pretreatment echocardiograms (n = 90) had echocardiographic evidence of PH. Thirty-eight (40%) patients met treatment response criteria. Responders had significant improvements in PaO2 (51 ± 3 vs 123 ± 7 mm Hg, P < .01), alveolar-arterial gradient (422 ± 30 vs 327 ± 27 mm Hg, P < .01), and PaO2 to FiO2 ratio (82 ± 10 vs 199 ± 15 mm Hg, P < .01). Nonresponders were more likely to have left ventricular systolic dysfunction (27% vs 8%, P = .03) on echocardiogram. Responders were less likely to require extracorporeal membrane support (50 vs 24%, P = .02)., Conclusions: iNO treatment is associated with improved oxygenation and reduced need for ECMO in a subpopulation of patients with CDH with PH and normal left ventricular systolic function., (Published by Elsevier Inc.)- Published
- 2020
- Full Text
- View/download PDF
24. The EXTrauterine Environment for Neonatal Development Supports Normal Intestinal Maturation and Development.
- Author
-
Baumgarten HD, Wright CM, Rossidis AC, Lawrence KM, Kim AG, Mejaddam AY, McGovern PE, Orr MN, Coons BE, Butt Z, Li H, Hwang G, Radu A, Brown LJ, Rubenstein RC, Peranteau WH, Davey M, Heuckeroth RO, and Flake AW
- Subjects
- Animals, Animals, Newborn, Disease Models, Animal, Enterocolitis, Necrotizing immunology, Female, Fetus immunology, Humans, Ileum immunology, Infant, Newborn, Intestinal Mucosa embryology, Intestinal Mucosa immunology, Premature Birth immunology, Sheep, Umbilical Cord blood supply, Enterocolitis, Necrotizing prevention & control, Extracorporeal Membrane Oxygenation methods, Fetal Organ Maturity immunology, Ileum embryology, Premature Birth therapy
- Abstract
Background and Aims: The Extra-Uterine Environment for Neonatal Development (EXTEND) aims to avoid the complications of prematurity, such as NEC. Our goal was to determine if bowel development occurs normally in EXTEND-supported lambs, with specific emphasis on markers of immaturity associated with NEC., Methods: We compared terminal ileum from 17 pre-term lambs supported on EXTEND for 2- 4 weeks to bowel from age-matched fetal lambs that developed in utero. We evaluated morphology, markers of epithelial integrity and maturation, enteric nervous system structure, and bowel motility., Results: EXTEND-supported lamb ileum had normal villus height, crypt depth, density of mucin-containing goblet cells, and enteric neuron density. Expression patterns for I-FABP, activated caspase-3 and EGFR were normal in bowel epithelium. Transmural resistance assessed in Ussing chambers was normal. Bowel motility was also normal as assessed by ex vivo organ bath and video imaging. However, Peyer's patch organization did not occur normally in EXTEND ileum, resulting in fewer circulating B cells in experimental animals., Conclusion: EXTEND supports normal ileal epithelial and enteric nervous system maturation in pre-term lambs. The classic morphologic changes and cellular expression profiles associated with NEC are not seen. However, immune development within the EXTEND supported lamb bowel does not progress normally., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2020
- Full Text
- View/download PDF
25. Prenatal hypoxemia alters microglial morphology in fetal sheep.
- Author
-
Lawrence KM, McGovern PE, Mejaddam A, Rossidis AC, Baumgarten H, Kim AG, Grinspan JB, Licht DJ, Radaelli E, Rychik J, Peranteau WH, Davey MG, Flake AW, and Gaynor JW
- Abstract
Objective: Neuroimmune cells, particularly microglia and astrocytes, play a critical role in neurodevelopment. Neurocognitive delays are common in children with congenital heart disease, but their etiology is poorly understood. Our objective was to determine whether prenatal hypoxemia, at levels common in congenital heart disease, induced neuroimmune activation to better understand the origins of neurobehavioral disorders in congenital heart disease., Methods: Eight fetal sheep at gestational age 109 ± 3 days (term ∼145 days) were cannulated onto a pumpless extracorporeal oxygenator via the umbilical vessels and supported in a fluid environment for 22 ± 2 days under normoxic (n = 4) or hypoxic (n = 4) conditions. Control fetuses (n = 7) were harvested at gestational age 133 ± 4 days. At necropsy, brains were stained with ionized calcium-binding adaptor molecule 1 and glial fibrillary acidic protein antibodies to quantify microglia and astrocytes, respectively, in gray and white matter in frontotemporal and cerebellar sections. Microglia were classified into 4 morphologic types based on cell shape. Data were analyzed with 1-way analysis of variance or Fisher exact test, as appropriate., Results: Oxygen delivery was significantly reduced in hypoxic fetuses (15.6 ± 1.8 mL/kg/min vs 24.3 ± 2.3 mL/kg/min; P < .01). Rates of apoptosis were similar in hypoxic, normoxic, and intrauterine control animals in all examined areas. There were also no differences between groups in area occupied by glial fibrillary acidic protein-labeled astrocytes or ionized calcium-binding adaptor molecule 1-labeled microglia in all examined areas. However, round microglia were significantly increased in hypoxic animals compared with normoxic animals (33% vs 6%; P < .01) and control animals (33% vs 11%; P < .01)., Conclusions: Prenatal hypoxemia altered microglial morphology without significant gliosis. Additional studies characterizing these mechanisms may provide insight into the origins of neurobehavioral disabilities in children with congenital heart disease., (Copyright © 2019. Published by Elsevier Inc.)
- Published
- 2020
- Full Text
- View/download PDF
26. A Rabbit Model for Optimization of Amniotic Fluid Components in the EXTrauterine Environment for Newborn Development (EXTEND) System.
- Author
-
Baumgarten HD, Hartman HA, Butt Z, Ozawa K, Rossidis AC, Lawrence KM, Kim AG, Davey M, and Flake AW
- Subjects
- Animals, Disease Models, Animal, Female, Fetal Weight, Intestines, Pregnancy, Rabbits, Amniotic Fluid, Fetal Development
- Abstract
In this model article, we present a protocol for continuous amniotic fluid exchange in rabbits using a novel system to test the effects of growth factor-deficient, artificial amniotic fluid on bowel development., Background: Ideally, the EXTrauterine Environment for Neonatal Development (EXTEND) will provide physiologic support to the extreme premature infant. An important component of that environment is the amniotic fluid. Thus, we developed an animal model to study the growth factors found within amniotic fluid and inform design of a synthetic fluid to optimize fetal development., Methods: We designed a model of amniotic fluid exchange within the pregnant rabbit, continuously removing the natural fluid from around 2 fetuses per doe and replacing it with a physiologic electrolyte solution during the final 100 h of gestation. Two fetuses from the contralateral uterine horn were used as sham-operated controls. Thirty-eight fetuses were analyzed, 19 in each group. We analyzed the fetal growth and bowel development., Results: Ultrasound after 100 h of exchange showed equivalent fluid volumes, p = 0.63. Cultures were negative for bacterial colonization. Final fluid protein concentrations were 11.6% that of control fluid (mean 1,451 ± 224.2 vs. 12,491 ± 849.2 μg/mL). There was no significant difference in fetal growth, with experimental weights 91.4% of control weights, p = 0.07. Fetal bowel weights (90.1%, p = 0.16) and lengths (94.2%, p = 0.49) were also not significantly less compared to controls. There was no significant difference in villous height or crypt depth measurements between the groups, and absorptive capacity of the bowel was not different between groups, p = 0.44., Conclusion: This animal model allows for manipulation of the components of amniotic fluid. Marked reduction of natural amniotic fluid proteins during gestation does not appear to significantly impair fetal growth or bowel development. Further work with this model will assess the importance of amniotic fluid components for normal development to inform design of a synthetic fluid for use during EXTEND., (© 2020 S. Karger AG, Basel.)
- Published
- 2020
- Full Text
- View/download PDF
27. Chronic intrauterine hypoxia alters neurodevelopment in fetal sheep.
- Author
-
Lawrence KM, McGovern PE, Mejaddam A, Rossidis AC, Baumgarten H, Kim A, Grinspan JB, Licht DJ, Didier RA, Vossough A, Radaelli E, Rychik J, Song L, Peranteau WH, Davey MG, Flake AW, and Gaynor JW
- Subjects
- Animals, Apoptosis, Brain metabolism, Brain pathology, Brain Diseases blood, Brain Diseases pathology, Capillaries pathology, Chronic Disease, Disease Models, Animal, Female, Fetal Blood metabolism, Fetal Development, Fetal Hypoxia blood, Fetal Hypoxia pathology, Gestational Age, Myelin Sheath metabolism, Oxygen blood, Pregnancy, Sheep, Domestic, Brain growth & development, Brain Diseases physiopathology, Capillaries physiopathology, Fetal Hypoxia physiopathology, Neovascularization, Physiologic, Neurogenesis, Neurons metabolism, Neurons pathology
- Abstract
Objective: We tested the hypothesis that chronic fetal hypoxia, at a severity present in many types of congenital heart disease, would lead to abnormal neurodevelopment., Methods: Eight mid-gestation fetal sheep were cannulated onto a pumpless extracorporeal oxygenator via the umbilical vessels and supported in a fluid-filled environment for 22 ± 2 days under normoxic or hypoxic conditions. Total parenteral nutrition was provided. Control fetuses (n = 7) were harvested at gestational age 133 ± 4 days. At necropsy, brains were fixed for histopathology. Neurons were quantified in white matter tracts, and the thickness of the external granular layer of the cerebellum was measured to assess neuronal migration. Capillary density and myelination were quantified in white matter. Data were analyzed with unpaired Student t tests or 1-way analysis of variance, as appropriate., Results: Oxygen delivery was reduced in hypoxic fetuses (15.6 ± 1.8 mL/kg/min vs 24.3 ± 2.3 mL/kg/min, P < .01), but umbilical blood flow and caloric delivery were not different between the 2 groups. Compared with normoxic and control animals, hypoxic fetuses had reduced neuronal density and increased external granular layer thickness. Compared with normoxic and control animals, hypoxic fetuses had increased capillary density in white matter. Cortical myelin integrity score was lower in the hypoxic group compared with normoxic and control animals. There was a significant negative correlation between myelin integrity and capillary density., Conclusions: Chronic fetal hypoxia leads to white matter hyper-vascularity, decreased neuronal density, and impaired myelination, similar to the neuropathologic findings observed in children with congenital heart disease. These findings support the hypothesis that fetal hypoxia, even in the setting of normal caloric delivery, impairs neurodevelopment., (Copyright © 2019. Published by Elsevier Inc.)
- Published
- 2019
- Full Text
- View/download PDF
28. Reply.
- Author
-
Hopper RK, Rogers R, Lawrence KM, and Hedrick HL
- Subjects
- Epoprostenol analogs & derivatives, Humans, Hernias, Diaphragmatic, Congenital, Hypertension, Pulmonary
- Published
- 2019
- Full Text
- View/download PDF
29. Chronically Hypoxic Fetal Lambs Supported by an Extra-Uterine Device Exhibit Mitochondrial Dysfunction and Elevations of Hypoxia Inducible Factor 1-Alpha.
- Author
-
Rossidis AC, Baumgarten HD, Lawrence KM, McGovern PE, Mejaddam AY, Li H, Hwang G, Young K, Peranteau WH, Davey MG, Gaynor JW, and Flake AW
- Subjects
- Animals, Female, Fetal Hypoxia blood, Placental Insufficiency blood, Pregnancy, Sheep, Fetal Hypoxia metabolism, Hypoxia-Inducible Factor 1, alpha Subunit blood, Membrane Potential, Mitochondrial physiology, Placental Insufficiency metabolism
- Abstract
Introduction: We have recently developed an extra-uterine environment for neonatal development (EXTEND) capable of supporting premature fetal lambs and have been able to replicate hypoxic in utero conditions by controlling fetal oxygen delivery. In this study, we investigated the fetal mitochondrial response to hypoxia., Methods: Eight premature fetal lambs were delivered via hysterotomy and transitioned to extra-uterine support for 3 weeks. The lambs were divided into 2 groups: normoxic fetuses which maintained physiologic oxygen delivery and hypoxic fetuses in which oxygen delivery was significantly reduced. Control fetuses were delivered via hysterotomy but not cannulated. Measurements of mitochondrial membrane potential (MMP) were performed in peripheral blood mononuclear cells., Results: There were no significant differences in MMP between normoxic EXTEND fetuses and controls. Hypoxic fetuses had significantly more depolarized mitochondria compared to normoxic fetuses overall, and these changes were specifically appreciated in weeks 1 and 2, but not by week 3. Hypoxic fetuses had significantly elevated levels of HIF-1α compared to normoxic fetuses in the first 2 weeks., Discussion: Normoxic fetal lambs supported by EXTEND demonstrate normal mitochondrial function as evidenced by equivalent membrane potentials compared to control fetuses. Hypoxic fetuses exhibit mitochondrial dysfunction, though they do show evidence of adaptation after 3 weeks of hypoxic exposure., (© 2018 S. Karger AG, Basel.)
- Published
- 2019
- Full Text
- View/download PDF
30. Use of prostaglandin E1 to treat pulmonary hypertension in congenital diaphragmatic hernia.
- Author
-
Lawrence KM, Berger K, Herkert L, Franciscovich C, O'Dea CLH, Waqar LN, Partridge E, Hanna BD, Peranteau WH, Avitabile CM, Hopper RK, Rintoul NE, and Hedrick HL
- Subjects
- Echocardiography methods, Female, Humans, Hypertension, Pulmonary complications, Infant, Newborn, Male, Natriuretic Peptide, Brain blood, Philadelphia, Registries, Retrospective Studies, Treatment Outcome, Alprostadil therapeutic use, Hernias, Diaphragmatic, Congenital complications, Hypertension, Pulmonary drug therapy, Vasodilator Agents therapeutic use
- Abstract
Background/purpose: Prostaglandin E1 (PGE) has been used to maintain ductus arteriosus patency and unload the suprasystemic right ventricle (RV) in neonates with congenital diaphragmatic hernia (CDH) and severe pulmonary hypertension (PH). Here we evaluate the PH response in neonates with CDH and severe PH treated with PGE., Methods: We performed a retrospective chart review of CDH infants treated at our center between 2011 and 2016. In a subset, PGE was initiated for echocardiographic evidence of severe PH, metabolic acidosis, or hypoxemia. To assess PH response, we evaluated laboratory data, including B-type natriuretic peptide (BNP) and echocardiograms before and after PGE treatment. Categorical and continuous data were analyzed with Fisher's exact tests and Mann-Whitney t-tests, respectively., Results: Fifty-seven infants were treated with PGE a mean 17 ± 2 days. BNP levels declined after 1.4 ± 0.2 days of treatment and again after 5.2 ± 0.6 days. After 6 ± 0.8 days of treatment, echocardiographic estimates of severe PH by tricuspid regurgitation jet velocity, ductus arteriosus direction, and ventricular septum position also improved significantly. Treatment was not associated with postductal hypoxemia or systemic hypoperfusion., Conclusions: In patients with CDH and severe PH, PGE is well tolerated and associated with improved BNP and echocardiographic indices of PH, suggesting successful unloading of the RV., Type of Study: Treatment study., Level of Evidence: Level III., (Copyright © 2018. Published by Elsevier Inc.)
- Published
- 2019
- Full Text
- View/download PDF
31. Erythropoietin Prevents Anemia and Transfusions in Extremely Premature Lambs Supported by an EXTrauterine Environment for Neonatal Development (EXTEND).
- Author
-
Mejaddam AY, Hornick MA, McGovern PE, Baumgarten HD, Lawrence KM, Rossidis AC, Hwang G, Young K, Abdulmalik O, Partridge EA, Peranteau WH, Davey MG, and Flake AW
- Subjects
- Animals, Drug Evaluation, Preclinical, Oxygen blood, Sheep, Anemia prevention & control, Erythropoietin therapeutic use, Intensive Care, Neonatal methods
- Abstract
Background: We recently developed an EXTrauterine Environment for Neonatal Development (EXTEND) that provides physiologic support for premature lambs. Here, we assess the efficacy of exogenous erythropoietin (EPO) to prevent anemia and transfusions on EXTEND., Materials and Methods: Lambs were cannulated at 0.7 gestation and supported on EXTEND for up to 4 weeks. The lambs were divided into three groups: (1) No EPO, (2) Low EPO (300 U kg-1 per day), and (3) High EPO (800 U kg-1 per day). Daily hematocrit and weekly complete blood count were assessed., Results: The mean percentage change in hematocrit from baseline was significantly different between the groups (No EPO -23.6 ± 7.8% vs. Low EPO -16.6 ± 6.4% vs. High EPO +2.6 ± 6.6%; p = 0.02). This occurred despite a greater median number of blood transfusions in the No EPO group (5 vs. 1 vs. 0; p = 0.02). EPO administration was associated with a higher mean corpuscular volume (MCV; p < 0.01) and reticulocyte count (p = 0.02). The High EPO group was comparable to in utero control fetuses with respect to hematocrit (p = 0.49), MCV (p = 0.24), and reticulocyte count (p = 0.68)., Conclusions: EPO (800 U kg-1 per day) prevents anemia, eliminates transfusions, and restores normal red blood cell indices in premature lambs supported by EXTEND., (© 2019 S. Karger AG, Basel.)
- Published
- 2019
- Full Text
- View/download PDF
32. Premature Lambs Exhibit Normal Mitochondrial Respiration after Long-Term Extrauterine Support.
- Author
-
Rossidis AC, Angelin A, Lawrence KM, Baumgarten HD, Kim AG, Mejaddam AY, Coons BE, Hartman HA, Hwang G, Monos S, Peranteau WH, Davey MG, Murdock D, Wallace DC, and Flake AW
- Subjects
- 8-Hydroxy-2'-Deoxyguanosine blood, Animals, Animals, Newborn, Bilirubin blood, Biomarkers blood, Cell Respiration, Female, Fetal Monitoring, Gestational Age, Oxygen Consumption, Oxygenators, Membrane, Pregnancy, Premature Birth metabolism, Premature Birth physiopathology, Sheep, Domestic, Time Factors, Artificial Organs, Energy Metabolism, Extracorporeal Membrane Oxygenation instrumentation, Mitochondria metabolism, Premature Birth therapy
- Abstract
Background: In an effort to mitigate the major morbidities and mortality associated with extreme prematurity, we have developed an EXTrauterine Environment for Neonatal Development (EXTEND) designed to provide physiologic support of extremely premature infants., Objectives: We have previously shown that long-term, physiologic support of premature fetal lambs is possible with EXTEND, but in this study, we sought to demonstrate bioenergetic equipoise at the tissue level., Methods: Four premature fetal lambs were delivered by hysterotomy at gestational ages (GA) of 105-107 days (term ∼145 days), cannulated via the umbilical vessels, and transitioned to support on EXTEND for 3-4 weeks. Five control fetuses were age-matched to the GA of experimental fetuses at the time of study end (128-134 days GA) and immediately sacrificed after hysterotomy. Mitochondria were isolated from the heart, liver, kidney, and skeletal muscle of fetuses at the time of sacrifice, and oxygen consumption rates (OCRs) were measured., Results: There were no differences in basal mitochondrial OCR between EXTEND and control fetuses for heart, kidney, or skeletal muscle. For liver, the basal OCR was higher in EXTEND fetuses compared to controls. There were no differences in physiologic maximal OCR or reserve capacity for any tissue analyzed., Conclusions: Fetal lambs supported by EXTEND demonstrate physiologic mitochondrial function as evidenced by adequate basal and physiologic maximal cellular respiration as well as preserved reserve capacity., (© 2019 S. Karger AG, Basel.)
- Published
- 2019
- Full Text
- View/download PDF
33. Fetal hypoxemia causes abnormal myocardial development in a preterm ex utero fetal ovine model.
- Author
-
Lawrence KM, Hennessy-Strahs S, McGovern PE, Mejaddam AY, Rossidis AC, Baumgarten HD, Bansal E, Villeda M, Han J, Gou Z, Zhao S, Rychik J, Peranteau WH, Davey MG, Flake AW, Gaynor JW, and Bartoli CR
- Subjects
- Animals, Cardiovascular Diseases embryology, Disease Models, Animal, Female, Fertility, Fetal Heart physiology, Humans, Hypoxia embryology, Infant, Newborn, Oxygen, Pregnancy, Sheep, Cardiovascular Diseases etiology, Fetus, Hypoxia complications, Maternal-Fetal Exchange, Myocardium pathology, Uterus
- Abstract
In utero hypoxia is a major cause of neonatal morbidity and mortality and predisposes to adult cardiovascular disease. No therapies exist to correct fetal hypoxia. In a new ex utero fetal support system, we tested the hypothesis that hypoxemic support of the fetus impairs myocardial development, whereas normoxic support allows normal myocardial development. Preterm fetal lambs were connected via umbilical vessels to a low-resistance oxygenator and placed in a sterile-fluid environment. Control normoxic fetuses received normal fetal oxygenation, and hypoxemic fetuses received subphysiologic oxygenation. Fetuses with normal in utero development served as normal controls. Hypoxemic fetuses exhibited decreased maximum cardiac output in both ventricles, diastolic function, myocyte and myocyte nuclear size, and increased myocardial capillary density versus control normoxic fetuses. There were no differences between control normoxic fetuses in the fetal support system and normal in utero controls. Chronic fetal hypoxemia resulted in significant abnormalities in myocyte architecture and myocardial capillary density as well as systolic and diastolic cardiac function, whereas control fetuses showed no differences. This ex utero fetal support system has potential to become a significant research tool and novel therapy to correct fetal hypoxia.
- Published
- 2018
- Full Text
- View/download PDF
34. Treprostinil Improves Persistent Pulmonary Hypertension Associated with Congenital Diaphragmatic Hernia.
- Author
-
Lawrence KM, Hedrick HL, Monk HM, Herkert L, Waqar LN, Hanna BD, Peranteau WH, Rintoul NE, and Hopper RK
- Subjects
- Antihypertensive Agents administration & dosage, Dose-Response Relationship, Drug, Epoprostenol administration & dosage, Female, Follow-Up Studies, Humans, Hypertension, Pulmonary etiology, Hypertension, Pulmonary physiopathology, Infant, Infant, Newborn, Male, Retrospective Studies, Treatment Outcome, Epoprostenol analogs & derivatives, Hernias, Diaphragmatic, Congenital complications, Hypertension, Pulmonary drug therapy, Pulmonary Wedge Pressure drug effects, Registries
- Abstract
Objective: To evaluate the effect of continuous treprostinil in infants with severe pulmonary hypertension associated with congenital diaphragmatic hernia (CDH) on specific markers of pulmonary hypertension severity and to report the safety and tolerability of treprostinil., Study Design: We conducted a retrospective cohort study of infants with CDH-associated pulmonary hypertension treated with treprostinil from January 2011 to September 2016. Severity of pulmonary hypertension was assessed by echocardiogram and serum B-type natriuretic peptide (BNP) by using time points before initiation and 24 hours, 1 week, and 1 month after treprostinil initiation. Fisher exact tests, Wilcoxon-rank sum tests, and mixed-effects models were used for analysis., Results: Seventeen patients were treated with treprostinil for a median of 54.5 days (IQR 44.3-110 days). Compared with the concurrent CDH population (n = 147), infants treated with treprostinil were more likely to require extracorporeal support (76.5% vs 25.2%, P < .0001), to have a longer hospital stay (144 vs 60 days, P < .0001), and to need longer mechanical ventilator support (76.5 vs 30.9 days, P < .0001). Following treprostinil initiation, there was a significant reduction in BNP at 1 week (1439 vs 393 pg/mL, P < .01) and 1 month (1439 vs 242 pg/mL, P = .01). Severity of pulmonary hypertension by echocardiogram improved at 1 month (OR 0.14, CI 95% 0.04-0.48, P = .002). Despite these improvements, overall mortality remained high (35%). There were no adverse events related to treprostinil, including no hypotension, hypoxia, or thrombocytopenia., Conclusions: In this cohort, treprostinil use was associated with improved severity of pulmonary hypertension assessed by echocardiogram and decreased BNP, with no significant side effects., (Copyright © 2018 Elsevier Inc. All rights reserved.)
- Published
- 2018
- Full Text
- View/download PDF
35. Clear cell and endometrioid carcinomas: are their differences attributable to distinct cells of origin?
- Author
-
Cochrane DR, Tessier-Cloutier B, Lawrence KM, Nazeran T, Karnezis AN, Salamanca C, Cheng AS, McAlpine JN, Hoang LN, Gilks CB, and Huntsman DG
- Subjects
- Carcinoma, Endometrioid pathology, Cells, Cultured, Cilia metabolism, Cilia pathology, Endometrial Neoplasms pathology, Epithelial Cells pathology, Female, Fluorescent Antibody Technique, Humans, Immunophenotyping methods, Neoplastic Stem Cells metabolism, Neoplastic Stem Cells pathology, Stem Cells pathology, Tissue Array Analysis, Biomarkers, Tumor metabolism, Carcinoma, Endometrioid metabolism, Cell Differentiation, Cell Lineage, Cystathionine gamma-Lyase metabolism, Endometrial Neoplasms metabolism, Epithelial Cells metabolism, Stem Cells metabolism
- Abstract
Endometrial epithelium is the presumed tissue of origin for both eutopic and endometriosis-derived clear cell and endometrioid carcinomas. We had previously hypothesized that the morphological, biological and clinical differences between these carcinomas are due to histotype-specific mutations. Although some mutations and genomic landscape features are more likely to be found in one of these histotypes, we were not able to identify a single class of mutations that was exclusively present in one histotype and not the other. This lack of genomic differences led us to an alternative hypothesis that these cancers could arise from distinct cells of origin within endometrial tissue, and that it is the cellular context that accounts for their differences. In a proteomic screen, we identified cystathionine γ-lyase (CTH) as a marker for clear cell carcinoma, as it is expressed at high levels in clear cell carcinomas of the ovary and endometrium. In the current study, we analysed normal Müllerian tissues, and found that CTH is expressed in ciliated cells of endometrium (both eutopic endometrium and endometriosis) and fallopian tubes. We then demonstrated that other ciliated cell markers are expressed in clear cell carcinomas, whereas endometrial secretory cell markers are expressed in endometrioid carcinomas. The same differential staining of secretory and ciliated cells was demonstrable in a three-dimensional organoid culture system, in which stem cells were stimulated to differentiate into an admixture of secretory and ciliated cells. These data suggest that endometrioid carcinomas are derived from cells of the secretory cell lineage, whereas clear cell carcinomas are derived from, or have similarities to, cells of the ciliated cell lineage. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd., (Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.)
- Published
- 2017
- Full Text
- View/download PDF
36. Chondroprotection by urocortin involves blockade of the mechanosensitive ion channel Piezo1.
- Author
-
Lawrence KM, Jones RC, Jackson TR, Baylie RL, Abbott B, Bruhn-Olszewska B, Board TN, Locke IC, Richardson SM, and Townsend PA
- Subjects
- Autocrine Communication, Calcium metabolism, Cartilage, Articular metabolism, Cell Survival drug effects, Cells, Cultured, Chondrocytes cytology, Chondrocytes metabolism, Cyclic AMP metabolism, Humans, Paracrine Communication, Peptide Fragments pharmacology, Peptides, Cyclic pharmacology, Protein Conformation, Pyrimidines pharmacology, Pyrroles pharmacology, Signal Transduction, Urocortins metabolism, Cartilage, Articular cytology, Ion Channels chemistry, Ion Channels metabolism, Receptors, Corticotropin-Releasing Hormone metabolism, Urocortins genetics
- Abstract
Osteoarthritis (OA) is characterised by progressive destruction of articular cartilage and chondrocyte cell death. Here, we show the expression of the endogenous peptide urocortin1 (Ucn1) and two receptor subtypes, CRF-R1 and CRF-R2, in primary human articular chondrocytes (AC) and demonstrate its role as an autocrine/paracrine pro-survival factor. This effect could only be removed using the CRF-R1 selective antagonist CP-154526, suggesting Ucn1 acts through CRF-R1 when promoting chondrocyte survival. This cell death was characterised by an increase in p53 expression, and cleavage of caspase 9 and 3. Antagonism of CRF-R1 with CP-154526 caused an accumulation of intracellular calcium (Ca
2+ ) over time and cell death. These effects could be prevented with the non-selective cation channel blocker Gadolinium (Gd3+ ). Therefore, opening of a non-selective cation channel causes cell death and Ucn1 maintains this channel in a closed conformation. This channel was identified to be the mechanosensitive channel Piezo1. We go on to determine that this channel inhibition by Ucn1 is mediated initially by an increase in cyclic adenosine monophosphate (cAMP) and a subsequent inactivation of phospholipase A2 (PLA2 ), whose metabolites are known to modulate ion channels. Knowledge of these novel pathways may present opportunities for interventions that could abrogate the progression of OA.- Published
- 2017
- Full Text
- View/download PDF
37. Urocortin suppresses endometrial cancer cell migration via CRFR2 and its system components are differentially modulated by estrogen.
- Author
-
Owens GL, Lawrence KM, Jackson TR, Crosbie EJ, Sayan BS, Kitchener HC, and Townsend PA
- Subjects
- Cell Line, Tumor, Cell Movement, Cell Proliferation, Endometrial Neoplasms genetics, Estrogen Receptor alpha metabolism, Estrogen Receptor beta metabolism, Female, Humans, Neoplasm Invasiveness, Receptors, Corticotropin-Releasing Hormone genetics, Urocortins genetics, Endometrial Neoplasms metabolism, Estrogen Receptor alpha genetics, Estrogen Receptor beta genetics, Estrogens pharmacology, Receptors, Corticotropin-Releasing Hormone metabolism, Urocortins metabolism
- Abstract
Urocortin (UCN1) peptide shares structural and functional homology with corticotropin-releasing factor (CRF). UCN1 is significantly reduced in endometrial adenocarcinoma compared to healthy controls. However, there are no data which evaluate the effects of UCN1 in the endometrium, or how it is modulated. We used proliferation and transwell assays to determine the effect of UCN1 on the proliferation and migration of Ishikawa and HEC1A cells. We also determined the expression levels of UCN1 and its receptors produced by estrogen receptor agonists, and the effect of UCN1 on estrogen receptor expression, using quantitative polymerase chain reaction. UCN1 suppressed migration of endometrial cancer cells in vitro. This effect appears to be specific to CRF receptor 2 (CRFR2), as selective antagonism of CRFR2 but not CRFR1 completely eliminated suppression of migration. Activation of ERA reduced UCN1 expression, but only had a small effect on the expression of CRFR1. However, expression of CRFR2 was more notably reduced at both the mRNA and protein levels by activation of ERB. UCN1 in turn reduced both ERA and ERB expression, as assessed by real-time quantitative PCR. We demonstrate that UCN1 significantly suppresses the migration of endometrial cancer cells but has no effect on their proliferation. Thus, loss of UCN1 in endometrial cancer may promote invasion and metastatic spread. There is a complex relationship between the UCN1 system and estrogen receptors, which may provide insights into endometrial carcinogenesis, a disease known to be driven by estrogen excess., (© 2016 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)
- Published
- 2017
- Full Text
- View/download PDF
38. Evaluation of multiple putative risk alleles within the 15q13.3 region for genetic generalized epilepsy.
- Author
-
Damiano JA, Mullen SA, Hildebrand MS, Bellows ST, Lawrence KM, Arsov T, Dibbens L, Major H, Dahl HH, Mefford HC, Darbro BW, Scheffer IE, and Berkovic SF
- Subjects
- Chromosomes, Human, Pair 15, DNA Copy Number Variations, Female, Gene Frequency, Genetic Loci, Humans, Male, Pedigree, Polymorphism, Genetic, Alleles, Epilepsy, Generalized genetics, Genetic Predisposition to Disease, alpha7 Nicotinic Acetylcholine Receptor genetics
- Abstract
The chromosome 15q13.3 region has been implicated in epilepsy, intellectual disability and neuropsychiatric disorders, especially schizophrenia. Deficiency of the acetylcholine receptor gene CHRNA7 and the partial duplication, CHRFAM7A, may contribute to these phenotypes and we sought to comprehensively analyze these genes in genetic generalized epilepsy. We analyzed using DHPLC, Sanger sequencing and long range PCR, 174 probands with genetic generalized epilepsy with or without intellectual disability or psychosis, including 8 with the recurrent 15q13.3 microdeletion. We searched CHRNA7 and CHRFAM7A for single sequence variants, small copy number variants, and the common 2-bp deletion in CHRFAM7A. We identified two novel and one reported missense variants. The common 2-bp deletion was not enriched in patients compared to controls. Our data suggest that missense mutations in CHRNA7 contribute to complex inheritance in genetic generalized epilepsy in a similar fashion to the 15q13.3 microdeletion. They do not support a pathogenic role for the common 2-bp CHRFAM7A deletion., (Copyright © 2015 Elsevier B.V. All rights reserved.)
- Published
- 2015
- Full Text
- View/download PDF
39. PRIMA1 mutation: a new cause of nocturnal frontal lobe epilepsy.
- Author
-
Hildebrand MS, Tankard R, Gazina EV, Damiano JA, Lawrence KM, Dahl HH, Regan BM, Shearer AE, Smith RJ, Marini C, Guerrini R, Labate A, Gambardella A, Tinuper P, Lichetta L, Baldassari S, Bisulli F, Pippucci T, Scheffer IE, Reid CA, Petrou S, Bahlo M, and Berkovic SF
- Abstract
Objective: Nocturnal frontal lobe epilepsy (NFLE) can be sporadic or autosomal dominant; some families have nicotinic acetylcholine receptor subunit mutations. We report a novel autosomal recessive phenotype in a single family and identify the causative gene., Methods: Whole exome sequencing data was used to map the family, thereby narrowing exome search space, and then to identify the mutation., Results: Linkage analysis using exome sequence data from two affected and two unaffected subjects showed homozygous linkage peaks on chromosomes 7, 8, 13, and 14 with maximum LOD scores between 1.5 and 1.93. Exome variant filtering under these peaks revealed that the affected siblings were homozygous for a novel splice site mutation (c.93+2T>C) in the PRIMA1 gene on chromosome 14. No additional PRIMA1 mutations were found in 300 other NFLE cases. The c.93+2T>C mutation was shown to lead to skipping of the first coding exon of the PRIMA1 mRNA using a minigene system., Interpretation: PRIMA1 is a transmembrane protein that anchors acetylcholinesterase (AChE), an enzyme hydrolyzing acetycholine, to membrane rafts of neurons. PRiMA knockout mice have reduction of AChE and accumulation of acetylcholine at the synapse; our minigene analysis suggests that the c.93+2T>C mutation leads to knockout of PRIMA1. Mutations with gain of function effects in acetylcholine receptor subunits cause autosomal dominant NFLE. Thus, enhanced cholinergic responses are the likely cause of the severe NFLE and intellectual disability segregating in this family, representing the first recessive case to be reported and the first PRIMA1 mutation implicated in disease.
- Published
- 2015
- Full Text
- View/download PDF
40. Urocortin--from Parkinson's disease to the skeleton.
- Author
-
Lawrence KM, Jackson TR, Jamieson D, Stevens A, Owens G, Sayan BS, Locke IC, and Townsend PA
- Subjects
- Animals, Arthritis genetics, Arthritis metabolism, Humans, Osteoporosis genetics, Osteoporosis metabolism, Parkinson Disease genetics, Urocortins genetics, Parkinson Disease metabolism, Urocortins metabolism
- Abstract
Urocortin (Ucn 1), a 40 amino acid long peptide related to corticotropin releasing factor (CRF) was discovered 19 years ago, based on its sequence homology to the parent molecule. Its existence was inferred in the CNS because of anatomical and pharmacological discrepancies between CRF and its two receptor subtypes. Although originally found in the brain, where it has opposing actions to CRF and therefore confers stress-coping mechanisms, Ucn 1 has subsequently been found throughout the periphery including heart, lung, skin, and immune cells. It is now well established that this small peptide is involved in a multitude of physiological and pathophysiological processes, due to its receptor subtype distribution and promiscuity in second messenger signalling pathways. As a result of extensive studies in this field, there are now well over one thousand peer reviewed publications involving Ucn 1. In this review, we intend to highlight some of the less well known actions of Ucn 1 and in particular its role in neuronal cell protection and maintenance of the skeletal system, both by conventional methods of reviewing the literature and using bioinformatics, to highlight further associations between Ucn 1 and disease conditions. Understanding how Ucn 1 works in these tissues, will help to unravel its role in normal and pathophysiological processes. This would ultimately allow the generation of putative medical interventions for the alleviation of important diseases such as Parkinson's disease, arthritis, and osteoporosis., (Copyright © 2014 Elsevier Ltd. All rights reserved.)
- Published
- 2015
- Full Text
- View/download PDF
41. Weight and fat distribution in patients taking valproate: a valproate-discordant gender-matched twin and sibling pair study.
- Author
-
Petty SJ, Kantor S, Lawrence KM, Berkovic SF, Collins M, Hill KD, Makovey J, Sambrook PN, O'Brien TJ, and Wark JD
- Subjects
- Abdominal Fat drug effects, Absorptiometry, Photon, Adult, Anticonvulsants therapeutic use, Blood Pressure drug effects, Body Composition drug effects, Diseases in Twins drug therapy, Epilepsy drug therapy, Female, Humans, Leptin blood, Male, Sex Factors, Siblings, Twins, Dizygotic, Twins, Monozygotic, Valproic Acid therapeutic use, Anticonvulsants adverse effects, Body Fat Distribution, Valproic Acid adverse effects, Weight Gain drug effects
- Abstract
Objectives: Chronic treatment with valproate (VPA) is commonly associated with weight gain, which potentially has important health implications, in particular increased central fat distribution. We utilized a VPA-discordant same-sex, twin and matched sibling pair study design to primarily examine for differences in fat distribution between patients with epilepsy treated with VPA compared to their matched twin or sibling control. Weight, blood pressure, and leptin levels were assessed., Methods: Height, weight, waist and hip measurements, exercise, blood pressure (BP), and serum leptin levels were measured. Body composition was measured using dual-energy x-ray absorptiometry (DXA). Abdominal fat was expressed as a percentage of the abdominal region (AFat%); and of whole body fat (WBF); (AFat%WBF). Mean within-pair differences were assessed (VPA-user and nonuser). Restricted maximum likelihood (REML) linear mixed model analysis was fitted to examine associations of anthropometrics, zygosity, gender, menopausal status, VPA dose and duration, with weight and AFat%., Results: We studied 19 pairs of VPA-discordant, gender-matched (five male, 14 female) twins and siblings. Mean (standard deviation, SD) duration of therapy for VPA users was 11.0 (7.4) years. There were no statistically significant within-pair differences in age, height, weight, body mass index (BMI), BP, leptin level, WBF, AFat%, or AFat%WBF. For pairs in which VPA-user was treated for >11 years there were statistically significant mean within-pair differences in AFat%, (+7.1%, p = 0.03, n = 10 pairs), mean BP (+11.0 mm Hg, p = 0.006, n = 8 pairs); but not in AFat%WBF. VPA duration was positively associated with weight (estimate +0.98 kg/per year of VPA, p = 0.03); VPA treatment duration and dose were not significantly associated with AFat%., Significance: This study demonstrated a relationship between long-term VPA use and abdominal adiposity (AFat%), which could have significant health implications. We recommend ongoing monitoring of weight, BMI, and blood pressure for patients taking VPA., (Wiley Periodicals, Inc. © 2014 International League Against Epilepsy.)
- Published
- 2014
- Full Text
- View/download PDF
42. Urocortin protects chondrocytes from NO-induced apoptosis: a future therapy for osteoarthritis?
- Author
-
Intekhab-Alam NY, White OB, Getting SJ, Petsa A, Knight RA, Chowdrey HS, Townsend PA, Lawrence KM, and Locke IC
- Subjects
- Base Sequence, Cell Survival, Cells, Cultured, Chondrocytes drug effects, Cytoprotection, DNA Primers genetics, Gene Expression, Humans, Nitric Oxide Donors pharmacology, Receptors, Corticotropin-Releasing Hormone metabolism, S-Nitroso-N-Acetylpenicillamine pharmacology, Urocortins genetics, Apoptosis, Chondrocytes physiology, Nitric Oxide physiology, Osteoarthritis drug therapy, Urocortins metabolism
- Abstract
Osteoarthritis (OA) is characterized by a loss of joint mobility and pain resulting from progressive destruction and loss of articular cartilage secondary to chondrocyte death and/ or senescence. Certain stimuli including nitric oxide (NO) and the pro-inflammatory cytokine tumor necrosis factor α (TNF-α have been implicated in this chondrocyte death and the subsequent accelerated damage to cartilage. In this study, we demonstrate that a corticotrophin releasing factor (CRF) family peptide, urocortin (Ucn), is produced by a human chondrocyte cell line, C-20/A4, and acts both as an endogenous survival signal and as a cytoprotective agent reducing the induction of apoptosis by NO but not TNF-α when added exogenously. Furthermore, treatment with the NO donor S-nitroso-N-acetyl-D-L-penicillamine upregulates chondrocyte Ucn expression, whereas treatment with TNF-α does not. The chondroprotective effects of Ucn are abolished by both specific ligand depletion (with an anti-Ucn antibody) and by CRF receptor blockade with the pan-CRFR antagonist α-helical CRH(9-41). CRFR expression was confirmed by reverse transcription-PCR with subsequent amplicon sequence analysis and demonstrates that C-20/A4 cells express both CRFR1 and CRFR2, specifically CRFR1α and CRFR2β. Protein expression of these receptors was confirmed by western blotting. The presence of both Ucn and its receptors in these cells, coupled with the induction of Ucn by NO, suggests the existence of an endogenous autocrine/paracrine chondroprotective mechanism against stimuli inducing chondrocyte apoptosis via the intrinsic/mitochondrial pathway.
- Published
- 2013
- Full Text
- View/download PDF
43. Genetics of febrile seizure subtypes and syndromes: a twin study.
- Author
-
Eckhaus J, Lawrence KM, Helbig I, Bui M, Vadlamudi L, Hopper JL, Scheffer IE, and Berkovic SF
- Subjects
- Child, Child, Preschool, Diseases in Twins diagnosis, Diseases in Twins epidemiology, Female, Follow-Up Studies, Humans, Infant, Male, Registries, Retrospective Studies, Seizures, Febrile diagnosis, Seizures, Febrile epidemiology, Diseases in Twins genetics, Seizures, Febrile genetics, Twins, Dizygotic genetics, Twins, Monozygotic genetics
- Abstract
Purpose: Febrile seizures (FS) are the most common seizure syndrome. A strong genetic component has been well established through family and twin studies; however, such studies have not examined the genetics of different FS types (simple, complex, febrile status epilepticus) and sub-syndromes (true FS, febrile seizures plus (FS+), 'FS with later epilepsy'). Here we used a community-based twin sample to analyze genetic factors within different FS subtypes and FS syndromes., Methods: Twin pairs were ascertained from the twin database of the Epilepsy Research Centre. A retrospective chart review was conducted and follow-up attempted for all subjects. Casewise concordance values were calculated for the different subgroups and intra-pair variation was analyzed., Key Findings: One hundred and seventy-nine twin pairs with FS were identified. Overall casewise concordance for FS in monozygotic (MZ) twins (0.62) was greater than in dizygotic (DZ) twins (0.16, p<0.0001). A greater concordance amongst MZ pairs than DZ twin pairs was also observed for all FS subtypes and FS sub-syndromes, particularly in twins with FS+. Within concordant MZ pairs, we did not observe the co-occurrence of FS and FS+., Significance: These results suggest a strong genetic contribution to different FS subtypes and sub-syndromes. They also support the existence of distinct genetic factors for different FS subtypes and sub-syndromes, especially FS+. This information is important for the strategic planning of next generation sequencing studies of febrile seizures., (Copyright © 2013 Elsevier B.V. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
44. Autosomal dominant vasovagal syncope: clinical features and linkage to chromosome 15q26.
- Author
-
Klein KM, Bromhead CJ, Smith KR, O'Callaghan CJ, Corcoran SJ, Heron SE, Iona X, Hodgson BL, McMahon JM, Lawrence KM, Scheffer IE, Dibbens LM, Bahlo M, and Berkovic SF
- Subjects
- Adolescent, Adult, Age of Onset, Child, Child, Preschool, DNA genetics, Electrocardiography, Electroencephalography, Female, Gene Dosage, Genes, Dominant, Genetic Linkage, Genome-Wide Association Study, Haplotypes, Humans, Male, Microsatellite Repeats, Monte Carlo Method, Mutation physiology, Pedigree, Phenotype, Syncope, Vasovagal physiopathology, Syncope, Vasovagal psychology, Young Adult, Chromosomes, Human, Pair 15 genetics, Syncope, Vasovagal genetics
- Abstract
Objective: To establish the occurrence of an autosomal dominant form of vasovagal syncope (VVS) by detailed phenotyping of multiplex families and identification of the causative locus., Methods: Patients with VVS and a family history of syncope were recruited. A standardized questionnaire was administered to all available family members and medical records were reviewed. Of 44 families recruited, 6 were suggestive of autosomal dominant inheritance. Genome-wide linkage was performed in family A using single nucleotide polymorphism genotyping microarrays. Targeted analysis of chromosome 15q26 with microsatellite markers was implemented in 4 families; 1 family was too small for analysis., Results: Family A contained 30 affected individuals over 3 generations with a median onset of 8 to 9 years. The other families comprised 4 to 14 affected individuals. Affected individuals reported typical triggers of VVS (sight of blood, injury, medical procedures, prolonged standing, pain, frightening thoughts). The triggers varied considerably within the families. Significant linkage to chromosome 15q26 (logarithm of odds score 3.28) was found in family A. Linkage to this region was excluded in 2 medium-sized families but not in 2 smaller families. Sequence analysis of the candidate genes SLCO3A1, ST8SIA2, and NR2F2 within the linkage interval did not reveal any mutations., Conclusions: Familial VVS, inherited in an autosomal dominant manner, may not be rare and has similar features to sporadic VVS. The chromosome 15q26 locus in family A increases the susceptibility to VVS but does not predispose to a particular vasovagal trigger. Linkage analysis in the remaining families established likely genetic heterogeneity.
- Published
- 2013
- Full Text
- View/download PDF
45. Early onset absence epilepsy: 1 in 10 cases is caused by GLUT1 deficiency.
- Author
-
Arsov T, Mullen SA, Damiano JA, Lawrence KM, Huh LL, Nolan M, Young H, Thouin A, Dahl HH, Berkovic SF, Crompton DE, Sadleir LG, and Scheffer IE
- Subjects
- Adolescent, Adult, Animals, Child, Child, Preschool, Cohort Studies, DNA Mutational Analysis, Evolution, Molecular, Female, Glucose Transporter Type 1 genetics, Humans, Male, Monosaccharide Transport Proteins deficiency, Carbohydrate Metabolism, Inborn Errors complications, Epilepsy, Absence etiology, Epilepsy, Absence genetics, Mutation genetics
- Abstract
Glucose transporter 1 (GLUT1) deficiency caused by mutations of SLC2A1 is an increasingly recognized cause of genetic generalized epilepsy. We previously reported that >10% (4 of 34) of a cohort with early onset absence epilepsy (EOAE) had GLUT1 deficiency. This study uses a new cohort of 55 patients with EOAE to confirm that finding. Patients with typical absence seizures beginning before 4 years of age were screened for solute carrier family 2 (facilitated glucose transporter), member 1 (SLC2A1) mutations or deletions. All had generalized spike-waves on electroencephalography (EEG). Those with tonic and/or atonic seizures were excluded. Mutations were found in 7 (13%) of 55 cases, including five missense mutations, an in-frame deletion leading to loss of a single amino acid, and a deletion spanning two exons. Over both studies, 11 (12%) of 89 probands with EOAE have GLUT1 deficiency. Given the major treatment and genetic counseling implications, this study confirms that SLC2A1 mutational analysis should be strongly considered in EOAE., (Wiley Periodicals, Inc. © 2012 International League Against Epilepsy.)
- Published
- 2012
- Full Text
- View/download PDF
46. Glucose transporter 1 deficiency in the idiopathic generalized epilepsies.
- Author
-
Arsov T, Mullen SA, Rogers S, Phillips AM, Lawrence KM, Damiano JA, Goldberg-Stern H, Afawi Z, Kivity S, Trager C, Petrou S, Berkovic SF, and Scheffer IE
- Subjects
- Adult, Aged, Animals, DNA Mutational Analysis, Evolution, Molecular, Female, Follow-Up Studies, Genotype, Glucose Transporter Type 1 deficiency, Humans, Male, Middle Aged, Monosaccharide Transport Proteins deficiency, Monosaccharide Transport Proteins genetics, Mutation genetics, Phenotype, Young Adult, Carbohydrate Metabolism, Inborn Errors complications, Carbohydrate Metabolism, Inborn Errors genetics, Epilepsy, Generalized etiology, Epilepsy, Generalized genetics, Glucose Transporter Type 1 genetics
- Abstract
Objective: We examined whether glucose transporter 1 (GLUT1) deficiency causes common idiopathic generalized epilepsies (IGEs)., Methods: The IGEs are common, heritable epilepsies that usually follow complex inheritance; currently little is known about their genetic architecture. Previously considered rare, GLUT1 deficiency, due to mutations in SLC2A1, leads to failure of glucose transport across the blood-brain barrier and inadequate glucose for brain metabolism. GLUT1 deficiency was first associated with an encephalopathy and more recently found in rare dominant families with epilepsy and paroxysmal exertional dyskinesia (PED). Five hundred four probands with IGEs and 470 controls underwent SLC2A1 sequencing. Glucose transport was assayed following expression of SLC2A1 variants in Xenopus oocytes. All available relatives were phenotyped, and SLC2A1 was sequenced., Results: Functionally validated mutations in SLC2A1 were present in 7 of 504 (1.4%) probands and 0 of 470 controls. PED, undiagnosed prior to study, occurred in 1 proband and 3 of 13 relatives with mutations. The IGEs in probands and relatives were indistinguishable from typical IGE. Three cases (0.6%) had mutations of large functional effect and showed autosomal dominant inheritance or were de novo. Four (0.8%) cases had a subtle functional effect; 2 showed possible dominant inheritance, and 2 did not. These alleles leading to subtle functional impairment may contribute to complex, polygenic inheritance of IGE., Interpretation: SLC2A1 mutations contribute to approximately 1% of IGE both as a dominant gene and as a susceptibility allele in complex inheritance. Diagnosis of GLUT1 deficiency has important treatment (ketogenic diet) and genetic counseling implications. The mechanism of restricted glucose delivery differs from the current focus on IGEs as ion channel disorders., (Copyright © 2012 American Neurological Association.)
- Published
- 2012
- Full Text
- View/download PDF
47. Hormone-stimulated modulation of endocytic trafficking in osteoclasts.
- Author
-
Stenbeck G, Lawrence KM, and Albert AP
- Abstract
A precise control of vesicular trafficking is crucial not only for osteoclastic bone resorption, but also for the crosstalk between osteoclasts and osteoblasts, which regulates bone homeostasis. In addition to the release of growth factors and modulators, such as glutamate, flux through the intracellular trafficking routes could also provide the osteoclast with a monitoring function of its resorption activity. To establish the signaling pathways regulating trafficking events in resorbing osteoclasts, we used the bone conserving hormone calcitonin, which has the unique property of inducing osteoclast quiescence. Calcitonin acts through the calcitonin receptor and activates multiple signaling pathways. By monitoring trafficking of a fluorescent low molecular weight probe in mature, bone resorbing osteoclasts we show for the first time that calcitonin blocks endocytosis from the ruffled border by phospholipase C (PLC) activation. Furthermore, we identify a requirement for polyunsaturated fatty acids in endocytic trafficking in osteoclasts. Inhibition of PLC prior to calcitonin treatment restores endocytosis to 75% of untreated rates. This effect is independent of protein kinase C activation and can be mimicked by an increase in intracellular calcium. We thus define an essential role for intracellular calcium levels in the maintenance of endocytosis in osteoclasts.
- Published
- 2012
- Full Text
- View/download PDF
48. Familial adult myoclonic epilepsy: recognition of mild phenotypes and refinement of the 2q locus.
- Author
-
Crompton DE, Sadleir LG, Bromhead CJ, Bahlo M, Bellows ST, Arsov T, Harty R, Lawrence KM, Dunne JW, Berkovic SF, and Scheffer IE
- Subjects
- Adolescent, Adult, Age Factors, Child, Child, Preschool, Chromosome Mapping, Chromosomes, Human, Pair 2, Electroencephalography, Electromyography, Evoked Potentials, Somatosensory genetics, Female, Humans, Italy, Male, Memory Disorders genetics, Middle Aged, Phenotype, Reflex genetics, Tremor etiology, Tremor genetics, Young Adult, Epilepsies, Myoclonic complications, Epilepsies, Myoclonic genetics, Family Health, Genetic Linkage, Memory Disorders etiology, Recognition, Psychology physiology
- Abstract
Background: Familial adult myoclonic epilepsy (FAME) is an autosomal dominant syndrome characterized by a core triad of cortical tremor, multifocal myoclonus, and generalized tonic-clonic seizures., Objectives: To expand the phenotypic spectrum of FAME, to highlight diagnostic pointers to this underrecognized disorder, and to refine the FAME2 genetic locus., Design: Observational family study., Setting: The study was coordinated in a tertiary academic hospital, with data acquired in diverse primary, secondary, and tertiary care settings., Participants: Consenting members of a single large family., Results: A 6-generation FAME kindred of European descent was ascertained in New Zealand and Australia. Affected family members (N = 55) had fine hand tremor, with onset typically in adolescence (median age, 15 years; age range, 4-60 years). Proximal myoclonus was present in 44 of 55 (80%), arising later than hand tremor (median age, 17 years; age range, 5-60 years). Generalized tonic-clonic seizures occurred in 8 of 55 (15%), with a median age at onset of 43.5 years (age range, 18-76 years). Neurophysiological testing confirmed features of cortical reflex myoclonus. Genetic mapping narrows the FAME2 (OMIM 607876) locus on chromosome 2 to a 13.3-megabase interval, harboring 99 known protein-coding genes., Conclusions: The most common FAME phenotype in this large family is mild postural hand tremor resembling essential tremor, combined with subtle proximal myoclonus. Generalized tonic-clonic seizures are uncommon and occur around sleep onset following severe generalized myoclonus.
- Published
- 2012
- Full Text
- View/download PDF
49. Urocortin is a novel regulator of osteoclast differentiation and function through inhibition of a canonical transient receptor potential 1-like cation channel.
- Author
-
Combs CE, Fuller K, Kumar H, Albert AP, Pirianov G, McCormick J, Locke IC, Chambers TJ, and Lawrence KM
- Subjects
- 3T3 Cells, Actin Cytoskeleton drug effects, Actin Cytoskeleton metabolism, Actin Cytoskeleton ultrastructure, Animals, Animals, Newborn, Bone Marrow Cells cytology, Bone Marrow Cells drug effects, Bone Marrow Cells metabolism, Bone Marrow Cells ultrastructure, Bone Resorption pathology, Bone Resorption physiopathology, Bone Resorption prevention & control, Bone and Bones cytology, Bone and Bones ultrastructure, Calcium Signaling, Cattle, Cell Differentiation, Cell Movement, Cells, Cultured, Gene Expression Regulation, Membrane Transport Modulators pharmacology, Mice, Osteoclasts drug effects, Osteoclasts ultrastructure, RNA, Messenger metabolism, Receptors, Corticotropin-Releasing Hormone antagonists & inhibitors, Receptors, Corticotropin-Releasing Hormone genetics, TRPC Cation Channels antagonists & inhibitors, TRPC Cation Channels genetics, Urocortins genetics, Osteoclasts cytology, Osteoclasts metabolism, Receptors, Corticotropin-Releasing Hormone metabolism, TRPC Cation Channels metabolism, Urocortins metabolism
- Abstract
This study investigated the role of urocortin (UCN), a member of the corticotrophin-releasing factor (CRF) family of peptides, in osteoclast maturation and function. We found that 10(-7) M UCN significantly (P<0.05) suppressed osteoclast differentiation from bone marrow precursor cells in culture and reduced the expression of several osteoclastic markers. Furthermore, UCN potently suppressed osteoclast bone resorption, by significantly inhibiting both the plan area of bone resorbed by osteoclasts and actin ring formation within osteoclasts at 10(-9) M (P<0.05), with complete inhibition at 10(-7) M (P<0.001). UCN also inhibited osteoclast motility (10(-7) M) but had no effect on osteoclast survival. Osteoclasts expressed mRNA encoding both UCN and the CRF receptor 2β subtype. Pre-osteoclasts however, expressed CRF receptor 2β alone. Unstimulated osteoclasts contained constitutively active cation channel currents with a unitary conductance of 3-4 pS, which were inhibited by over 70% with UCN (10(-7) M). Compounds that regulate calcium signalling and energy status of the cell, both crucial for osteoclast activity were investigated. The non-selective cation channel blockers, lanthanum (La(3)(+)) and gadolinium (Gd(3)(+)), inhibited actin ring formation in osteoclasts, whereas modulators of voltage-dependent Ca(2)(+) channels and K(ATP) channels had no effect. These findings show for the first time that UCN is a novel anti-resorptive molecule that acts through a direct effect on osteoclasts and their precursor cells.
- Published
- 2012
- Full Text
- View/download PDF
50. Familial mesial temporal lobe epilepsy: a benign epilepsy syndrome showing complex inheritance.
- Author
-
Crompton DE, Scheffer IE, Taylor I, Cook MJ, McKelvie PA, Vears DF, Lawrence KM, McMahon JM, Grinton BE, McIntosh AM, and Berkovic SF
- Subjects
- Adolescent, Adult, Child, Child, Preschool, Epilepsy, Complex Partial diagnosis, Epilepsy, Temporal Lobe diagnosis, Female, Humans, Male, Middle Aged, Pedigree, Syndrome, Young Adult, Diseases in Twins genetics, Epilepsy, Complex Partial genetics, Epilepsy, Complex Partial physiopathology, Epilepsy, Temporal Lobe genetics, Epilepsy, Temporal Lobe physiopathology, Inheritance Patterns genetics
- Abstract
Temporal lobe epilepsy is the commonest partial epilepsy of adulthood. Although generally perceived as an acquired disorder, several forms of familial temporal lobe epilepsy, with mesial or lateral seizure semiology, have been described. Descriptions of familial mesial temporal lobe epilepsy have varied widely from a benign epilepsy syndrome with prominent déjà vu and without antecedent febrile seizures or magnetic resonance imaging abnormalities, to heterogeneous, but generally more refractory epilepsies, often with a history of febrile seizures and with frequent hippocampal atrophy and high T₂ signal on magnetic resonance imaging. Compelling evidence of a genetic aetiology (rather than chance aggregation) in familial mesial temporal lobe epilepsy has come from twin studies. Dominant inheritance has been reported in two large families, though the usual mode of inheritance is not known. Here, we describe clinical and neurophysiological features of 20 new mesial temporal lobe epilepsy families including 51 affected individuals. The epilepsies in these families were generally benign, and febrile seizure history was infrequent (9.8%). No evidence of hippocampal sclerosis or dysplasia was present on brain imaging. A single individual underwent anterior temporal lobectomy, with subsequent seizure freedom and histopathological evidence of hippocampal sclerosis was not found. Inheritance patterns in probands' relatives were analysed in these families, together with 19 other temporal lobe epilepsy families previously reported by us. Observed frequencies of epilepsies in relatives were lower than predicted by dominant Mendelian models, while only a minority (8/39) of families could be compatible with recessive inheritance. These findings strongly suggest that complex inheritance, similar to that widely accepted in the idiopathic generalized epilepsies, is the usual mode of inheritance in familial mesial temporal lobe epilepsy. This disorder, which appears to be relatively common, and not typically associated with hippocampal sclerosis, is an appropriate target for contemporary approaches to complex disorders such as genome-wide association studies for common genetic variants or deep sequencing for rare variants.
- Published
- 2010
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.