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Gallbladder agenesis is a rare anatomic congenital abnormality caused by the cystic bud failing to develop into the gallbladder. Gallbladder agenesis has a variable presentation, with 50% of patients presenting with symptoms mimicking biliary colic and 35% being incidentally discovered during surgery or autopsy, while another 15% can present with fatal fetal anomalies. In this article, we present a case of gallbladder agenesis in a young woman who presented with biliary-colic-like symptoms suggesting cholecystitis. The gallbladder was not well visualized on ultrasonography, simulating chronic cholecystitis due to shrunken or contracted bladder. Further imaging with computed tomography (CT) and magnetic resonance cholangiopancreatography (MRCP) helped in the successful diagnosis of gallbladder agenesis and helped prevent unnecessary surgical intervention. Due to the lack of clinical suspicion diagnosing gallbladder agenesis preoperatively is still rare. Persistent symptoms are often associated with biliary colic pain leading to surgery. Conservative management consists of using antispasmodic medications. MRCP may be required to rule out gallbladder agenesis and avoid unnecessary surgery. Gallbladder agenesis can present with symptoms similar to cholecystitis. If the gallbladder is not visualized well on the ultrasound, an additional radiological examination is required. Clinicians' understanding of the condition helps to accurately diagnose the condition preoperatively using the appropriate investigations, thereby minimizing the operative risk to the patient.

The molecular composition of myelin membranes determines their structure and function. Even minute changes to the biochemical balance can have profound consequences for axonal conduction and the synchronicity of neural networks. Hypothesizing that the earliest indication of myelin injury involves changes in the composition and/or polarity of its constituent lipids, we developed a sensitive spectroscopic technique for defining the chemical polarity of myelin lipids in fixed frozen tissue sections from rodent and human. The method uses a simple staining procedure involving the lipophilic dye Nile Red, whose fluorescence spectrum varies according to the chemical polarity of the microenvironment into which the dye embeds. Nile Red spectroscopy identified histologically intact yet biochemically altered myelin in prelesioned tissues, including mouse white matter following subdemyelinating cuprizone intoxication, as well as normal-appearing white matter in multiple sclerosis brain. Nile Red spectroscopy offers a relatively simple yet highly sensitive technique for detecting subtle myelin changes.

BackgroundAmyotrophic lateral sclerosis (ALS) is a disabling and rapidly progressive neurodegenerative disorder. Increasing age is an important risk factor for developing ALS, thus the societal impact of this devastating disease will become more profound as the population ages. A significant hurdle to finding effective treatment has been an inability to accurately quantify cerebral degeneration associated with ALS in humans. Advanced magnetic resonance imaging (MRI) techniques hold promise in providing a set of biomarkers to assist in aiding diagnosis and in efficiently evaluating new drugs to treat ALS.MethodsThe Canadian ALS Neuroimaging Consortium (CALSNIC) was founded to develop and evaluate advanced MRI-based biomarkers that delineate biological heterogeneity, track disease progression, and predict survival in a large and heterogeneous sample of ALS patients.FindingsCALSNIC has launched two studies to date (CALSINC-1, CALSNIC-2), acquiring multimodal neuroimaging, neurological, neuropsychological data, and neuropathological data from ALS patients and healthy controls in a prospective and longitudinal fashion from multiple centres in Canada and, more recently, the United States. Clinical and MRI protocols are harmonized across research centres and different MR vendors.InterpretationCALSNIC provides a multicentre platform for studying ALS biology and developing MRI-based biomarkers.FundingCanadian Institutes of Health Research, ALS Society of Canada, Brain Canada Foundation, Shelly Mrkonjic Research Fund

The article published by Kevin Cowart in this issue of the Journal of Diabetes Science and Technology (JDST) is a detailed overview of the clinical trial data and analysis used to demonstrate the safety and effectiveness of the Eversense continuous glucose monitoring (CGM) System for regulatory approval and clinical acceptance. The article describes the published study results for safety, accuracy, reliability, ease of insertion/removal, adverse events, and ease of diabetes patient-use for controlling their glucose levels short and long term. The author nicely compares Eversense CGM System safety and performance with the short-term subcutaneous tissue CGM systems being commercialized by Dexcom, Medtronic Diabetes, and Abbott Diabetes. This comparison may help the clinician define which type of patient with diabetes might benefit the most from the long-term implantable CGM system. The majority of studied patients describe a positive experience managing their diabetes with the Eversense CGM System and request implantation of a new sensor 90 or 180 days later.

Endocrine mucin–producing sweat gland carcinoma (EMPSGC) is a slow-growing, rare variant of mucinous carcinoma most commonly presenting on the eyelid.1, 2 Its rarity, inflammatory characteristics, and slow-growing nature all increase the risk of misdiagnosis.2 We present a case of a EMPSGC initially diagnosed as a chalazion. Conservative treatment was attempted on multiple occasions and over an extended period, despite a lack of clinical response. This treatment caused a delay in diagnosis and appropriate treatment for this rare malignant lesion. Our case illustrates EMPSGC as a lesion that can masquerade as a chalazion or hordeolum.

This short comunication is a comment on recently published article in AAS by Ylikoski et al. The article stressed the importance of hyperglycemia control awareness and the difficulty of implementation even in a modern hospital setting. 1 When participating in a research study, patients usually get more attention, but despite the research setting in this study, hyperglycemia accrued in over 80% of patients, and none of the hyperglycemic patients were treated according to the hospital guidelines. We are intrigued that 14 years after we presented similar data at the American Society of Anesthesiologists meeting in 2006 (ASA 2006) “Glucose Management in Orthopedic Surgery Patients” not much has changed. We reported that 51 patients had high blood glucose (BG) values (≥15.5 mmol/l), but in only 47% of these cases was the primary physician alerted to assess the patient for a possible change in therapy, as it was the standard protocol in our hospital. Moreover, only four patients (8%) had their glucose management adjusted. On the day of surgery, 21 patients had a BG ≥11.1 mmol/l. However, no cases were canceled including two patients with a BG >16.7 mmol/l. One patient was not diagnosed in the medical record as having diabetes although his preoperative BG was 20.4 mmol/l. Furthermore, his BG was not checked on the morning of the surgery, and yet his first BG was 19.9 mmol/l the night of surgery and 26 mmol/l at 4 am on the first postoperative day. Insulin was not started until 9 am when his BG was 30.5 mmol/l. This emphasizes the importance of glucose control even in patients who are not diagnosed as having diabetes.

Subcutaneous (s.c.) glucose sensors have become a key component in type 1 diabetes management. However, their usability is limited by the impact of foreign body response (FBR) on their duration, reliability, and accuracy. Our study gives the first description of human acute and subacute s.c. response to glucose sensors, showing the changes observed in the sensor surface, the inflammatory cells involved in the FBR and their relationship with sensor performance.Twelve obese patients (seven type 2 diabetes) underwent two abdominal biopsies comprising the surrounding area where they had worn two glucose sensors: the first one inserted 7 days before and the second one 24 h before biopsy procedure. Samples were processed and studied to describe tissue changes by two independent pathologists (blind regarding sensor duration). Macrophages quantification was studied by immunohistochemistry methods in the area surrounding the sensor (CD68, CD163). Sensor surface changes were studied by scanning electron microscopy. Seven-day continuous glucose monitoring records were considered inaccurate when mean absolute relative difference was higher than 10%.Pathologists were able to correctly classify all the biopsies regarding sensor duration. Acute response (24 h) was characterized by the presence of neutrophils while macrophages were the main cell involved in subacute inflammation. The number of macrophages around the insertion hole was higher for less accurate sensors compared with those performing more accurately (32.6 ± 14 vs. 10.6 ± 1 cells/0.01 mmThe accumulation of macrophages at the sensor-tissue interface is related with decrease in accuracy of the glucose measure.

To explore pathogenesis in a young Gerstmann-Sträussler-Scheinker Disease (GSS) patient, the corresponding mutation, an eight-residue duplication in the hydrophobic region (HR), was inserted into the wild type mouse PrP gene. Transgenic (Tg) mouse lines expressing this mutation (Tg.HRdup) developed spontaneous neurologic syndromes and brain extracts hastened disease in low-expressor Tg.HRdup mice, suggesting de novo formation of prions. While Tg.HRdup mice exhibited spongiform change, PrP aggregates and the anticipated GSS hallmark of a proteinase K (PK)-resistant 8 kDa fragment deriving from the center of PrP, the LGGLGGYV insertion also imparted alterations in PrP's unstructured N-terminus, resulting in a 16 kDa species following thermolysin exposure. This species comprises a plausible precursor to the 8 kDa PK-resistant fragment and its detection in adolescent Tg.HRdup mice suggests that an early start to accumulation could account for early disease of the index case. A 16 kDa thermolysin-resistant signature was also found in GSS patients with P102L, A117V, H187R and F198S alleles and has coordinates similar to GSS stop codon mutations. Our data suggest a novel shared pathway of GSS pathogenesis that is fundamentally distinct from that producing structural alterations in the C-terminus of PrP, as observed in other prion diseases such as Creutzfeldt-Jakob Disease and scrapie., Author summary Prion diseases can be sporadic, infectious or genetic. The central event of all prion diseases is the structural conversion of the cellular prion protein (PrPC) to its disease associated conformer, PrPSc. Gerstmann-Sträussler-Scheinker Disease (GSS) is a genetic prion disease presenting as a multi-systemic neurological syndrome. A novel mutation, an eight amino acid insertion, was discovered in a young GSS patient. We created transgenic mice expressing this mutation and found that they recapitulate key features of the disease; namely PrP deposition in the brain and a low molecular weight proteinase K (PK) resistant internal PrP fragment. While structural investigations did not reveal a gross alteration in the conformation of this mutant PrP, the insertion lying at the boundary of the globular domain causes alterations in the unstructured amino terminal portion of the protein such that it becomes resistant to digestion by the enzyme thermolysin. We demonstrate by kinetic analysis and sequential digestion that this novel thermolysin resistant species is a precursor to the pathognomonic PK resistant fragment. Analysis of samples from other GSS patients revealed this same signature, suggesting a common molecular pathway.

As an extension of the brain, the spinal cord has unique properties which could allow us to gain a better understanding of CNS pathology. The brain and cord share the same cellular components, yet the latter is simpler in cytoarchitecture and connectivity. In Alzheimers research, virtually all focus is on brain pathology, however it has been shown that transgenic Alzheimers mouse models accumulate beta amyloid plaques in spinal cord, suggesting that the cord possesses the same molecular machinery and conditions for plaque formation. Here we report a spatial-temporal map of plaque load in 5xFAD mouse spinal cord. We found that plaques started to appear at 11 weeks, then exhibited a time dependent increase and differential distribution along the cord. More plaques were found in cervical than other spinal levels at all time points examined. Despite heavy plaque load at 6 months, the number of cervical motor neurons in 5xFAD mice is comparable to wild type littermates. On detailed microscopic examination, fine beta amyloid-containing and beta sheet-rich thread-like structures were found in the peri-axonal space of many axons. Importantly, these novel structures appear before any plaque deposits are visible in young mice spinal cord and they co-localize with axonal swellings at later stages, suggesting that these thread-like structures might represent the initial stages of plaque formation, and could play a role in axonal damage. Additionally, we were able to demonstrate increasing myelinopathy in aged 5xFAD mouse spinal cord using the lipid probe Nile Red with high resolution. Collectively, we found significant amyloid pathology in grey and white matter of the 5xFAD mouse spinal cord which indicates that this structure maybe a useful platform to study mechanisms of Alzheimers pathology and disease progression. Funding Agencies|Dr. Frank Leblanc Chair for Spinal Cord Research; Canadian Institutes of Health Research (CIHR); Canada Research Chairs (CRC); Alberta Prion Research Institute (APRI)

In the present era of near-continuous glucose monitoring (CGM) and automated therapeutic closed-loop systems, measures of accuracy and of quality of glucose control need to be standardized for licensing authorities and to enable comparisons across studies and devices. Adequately powered, good quality, randomized, controlled studies are needed to assess the impact of different CGM devices on the quality of glucose control, workload, and costs. The additional effects of continuing glucose control on the general floor after the ICU stay also need to be investigated. Current algorithms need to be adapted and validated for CGM, including effects on glucose variability and workload. Improved collaboration within the industry needs to be encouraged because no single company produces all the necessary components for an automated closed-loop system. Combining glucose measurement with measurement of other variables in 1 sensor may help make this approach more financially viable.

In this work we develop an ordinary differential equations (ODE) model of physiological regulation of glycemia in type 1 diabetes mellitus (T1DM) patients in response to meals and intravenous insulin infusion. Unlike for the majority of existing mathematical models of glucose-insulin dynamics, parameters in our model are estimable from a relatively small number of noisy observations of plasma glucose and insulin concentrations. For estimation, we adopt the generalized smoothing estimation of nonlinear dynamic systems of Ramsay et al. [J. R. Stat. Soc. Ser. B Stat. Methodol. 69 (2007) 741-796]. In this framework, the ODE solution is approximated with a penalized spline, where the ODE model is incorporated in the penalty. We propose to optimize the generalized smoothing by using penalty weights that minimize the covariance penalties criterion (Efron [J. Amer. Statist. Assoc. 99 (2004) 619-642]). The covariance penalties criterion provides an estimate of the prediction error for nonlinear estimation rules resulting from nonlinear and/or nonhomogeneous ODE models, such as our model of glucose-insulin dynamics. We also propose to select the optimal number and location of knots for B-spline bases used to represent the ODE solution. The results of the small simulation study demonstrate advantages of optimized generalized smoothing in terms of smaller estimation errors for ODE parameters and smaller prediction errors for solutions of differential equations. Using the proposed approach to analyze the glucose and insulin concentration data in T1DM patients, we obtained good approximation of global glucose-insulin dynamics and physiologically meaningful parameter estimates., Comment: Published in at http://dx.doi.org/10.1214/13-AOAS706 the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org)

The management reporting and assessment of glycemic control lacks standardization. The use of different methods to measure the blood glucose concentration and to report the performance of insulin treatment yields major disparities and complicates the interpretation and comparison of clinical trials. We convened a meeting of 16 experts plus invited observers from industry to discuss and where possible reach consensus on the most appropriate methods to measure and monitor blood glucose in critically ill patients and on how glycemic control should be assessed and reported. Where consensus could not be reached, recommendations on further research and data needed to reach consensus in the future were suggested. Recognizing their clear conflict of interest, industry observers played no role in developing the consensus or recommendations from the meeting. Consensus recommendations were agreed for the measurement and reporting of glycemic control in clinical trials and for the measurement of blood glucose in clinical practice. Recommendations covered the following areas: How should we measure and report glucose control when intermittent blood glucose measurements are used? What are the appropriate performance standards for intermittent blood glucose monitors in the ICU? Continuous or automated intermittent glucose monitoring - methods and technology: can we use the same measures for assessment of glucose control with continuous and intermittent monitoring? What is acceptable performance for continuous glucose monitoring systems? If implemented, these recommendations have the potential to minimize the discrepancies in the conduct and reporting of clinical trials and to improve glucose control in clinical practice. Furthermore, to be fit for use, glucose meters and continuous monitoring systems must match their performance to fit the needs of patients and clinicians in the intensive care setting., JOURNAL ARTICLE, SCOPUS: re.j, info:eu-repo/semantics/published

Molecular genetic analyses of experimental crosses provide important information on the strength and nature of post-mating barriers to gene exchange between divergent populations, which are topics of great interest to evolutionary geneticists and breeders. Although not a trivial task in long-lived organisms such as trees, experimental interspecific recombinants can sometimes be created through controlled crosses involving natural F 1 's. Here, we used this approach to understand the genetics of post-mating isolation and barriers to introgression in Populus alba and Populus tremula, two ecologically divergent, hybridizing forest trees. We studied 86 interspecific backcross (BC 1) progeny and 350 individuals from natural populations of these species for up to 98 nuclear genetic markers, including microsatellites, indels and single nucleotide polymorphisms, and inferred the origin of the cytoplasm of the cross with plastid DNA. Genetic analysis of the BC 1 revealed extensive segregation distortions on six chromosomes, and 90% of these (12 out oF 13) favored P. tremula donor alleles in the heterospecific genomic background. Since selection was documented during early diploid stages of the progeny, this surprising result was attributed to epistasis, cyto-nuclear coadaptation, heterozygote advantage at nuclear loci experiencing introgression or a combination of these. Our results indicate that gene flow across porous species barriers affects these poplars and aspens beyond neutral, Mendelian expectations and suggests the mechanisms responsible. Contrary to expectations, the Populus sex determination region is not protected from introgression. Understanding the population dynamics of the Populus sex determination region will require tests based on natural interspecific hybrid zones. © 2011 Macmillan Publishers Limited All rights reserved.