Search

Loss-of-function variants in SYNGAP1 cause a developmental encephalopathy defined by cognitive impairment, autistic features, and epilepsy. SYNGAP1 splicing leads to expression of distinct functional protein isoforms. Splicing imparts multiple cellular functions of SynGAP proteins through coding of distinct C-terminal motifs. However, it remains unknown how these different splice sequences function in vivo to regulate neuronal function and behavior. Reduced expression of SynGAP-α1/2 C-terminal splice variants in mice caused severe phenotypes, including reduced survival, impaired learning, and reduced seizure latency. In contrast, upregulation of α1/2 expression improved learning and increased seizure latency. Mice expressing α1-specific mutations, which disrupted SynGAP cellular functions without altering protein expression, promoted seizure, disrupted synapse plasticity, and impaired learning. These findings demonstrate that endogenous SynGAP isoforms with α1/2 spliced sequences promote cognitive function and impart seizure protection. Regulation of SynGAP-αexpression or function may be a viable therapeutic strategy to broadly improve cognitive function and mitigate seizure.

El siguiente artículo realiza un recorrido teórico sobre el juego, a través de diferentes autores que describen su naturaleza, características, aplicaciones e impacto en las personas. Esto con el fin de reflexionar acerca de los elementos extrapolados a los videojuegos; una extensión de la práctica del juego llevado a cabo en un ambiente digital.

Resumen: Introducción: Un porcentaje de pacientes intervenidos de cirugía cardiaca presentan fracaso cardiorrespiratorio refractario a medidas convencionales, y precisan soporte circulatorio y respiratorio con membrana de oxigenación extracorpórea (ECMO) en el postoperatorio. Métodos: En los últimos 20 años, 119 pacientes pediátricos precisaron ECMO en nuestro centro.El 46% de los pacientes fueron neonatos, con una edad media de 15,4 meses y un peso de 6,9 kg.La principal indicación (60%) fue incapacidad de destete de la circulación extracorpórea. Resultados: De los 119 pacientes intervenidos se consiguió un éxito de destete en el 63%, con un porcentaje de supervivencia del 50%. A partir del año 2009, se consigue el destete en el 78% de los pacientes, con supervivencia del 66%.Los factores de riesgo asociados con mortalidad en el análisis univariante fueron: sexo masculino, periodo neonatal, la primera etapa (antes de 2009), cardioplejía St. Thomas, tiempo de circulación extracorpórea, no drenaje de cavidades izquierdas, duración de la ECMO menos de 2 días o más de 5, y el uso de dispositivo diferente de la centrífuga de segunda generación.El 47% de los pacientes necesitaron algún tipo de reintervención. Conclusiones: Se trata de una serie amplia de ECMO poscardiotomía en la edad pediátrica, con buenos resultados de destete y supervivencia, especialmente en la última década (66% de supervivencia).La mitad de los pacientes necesitaron algún tipo de reintervención, por lo que es muy importante la búsqueda de lesiones residuales postoperatorias. Abstract: Introduction: A percentage of patients undergoing cardiac surgery present with cardiorespiratory failure refractory to maximal conventional therapy during the post-operative period, and require circulatory and respiratory support with extracorporeal membrane oxygenation (ECMO). Methods: A total of 119 paediatric patients required ECMO after cardiotomy in our institution.Just under half (46%) of the patients were neonates, with a mean age of 15.4 months and mean weight of 6.9 kg.The main indication (60%) was the impossibility to wean the patient off extracorporeal circulation. Results: Of the 119 patients, weaning off ECMO was achieved in 63%, with a survival rate of 50%. As of 2009, weaning rate was 78%, with 66% survival.The risk factors associated with mortality in the univariate analysis were: male gender, neonatal period, and the first era (before 2009), as well as St. Thomas Cardioplegia, extracorporeal circulation time, no left cavities drainage, ECMO duration of less than two days or more than 5, and the use of a device different from the second generation centrifuge pump.Just under half (47%) of the patients needed some type of re-intervention. Conclusions: This is a wide series of post-cardiotomy ECMO in patients of paediatric age, with good weaning and survival results, especially in the last decade (66% survival).Some type of re-intervention was required by 47% of the patients, making it very important to look actively for residual post-operative residual lesions. Palabras clave: Oxigenación por membrana extracorpórea, Poscardiotomía, Cardiopatía, Congénita, Factores de riesgo, Keywords: Extracorporeal membrane oxigenation, Post-cardiotomy, Heart disease, Congenital, Risk-factors

Introducción. La arteria laberíntica transcurre a través del meato acústico interno hasta llegar al oído interno, aportando allí su irrigación. Se han descrito dos posibles variantes anatómicas de su origen: como rama directa de la arteria basilar o como rama de la arteria cerebelosa anteroinferior. Objetivo. Identificar la prevalencia del origen de la arteria laberíntica. Materiales y métodos. Se realizó un estudio analítico descriptivo con métodos cuantitativos sobre el origen de la arteria laberíntica en una muestra de 29 encéfalos obtenidos por muestreo a conveniencia. Resultados. Se determinó que la arteria laberíntica se originó de la arteria basilar en 22 (75.9%) encéfalos; en los 7 (24.1%) restantes esta surgía como rama de la arteria cerebelosa anteroinferior. Conclusión. El origen de la arteria laberíntica en la muestra seleccionada tiene una mayor prevalencia en la arteria basilar respecto a la arteria cerebelosa anteroinferior, hallazgo que se asemeja a algunas investigaciones contrastadas con este estudio.

Introducción: En el presente trabajo se exponen algunas consideraciones de los autores sobre la pesquisa activa ante la COVID-19 en el Consultorio Médico de la Familia # 9 del Policlínico Manuel Díaz Legra, del municipio de Holguín. Se abordan los antecedentes en nuestro país, el concepto de pesquisa activa, las peculiaridades con la epidemia y su comportamiento en un área de salud. Se presentan los resultados preliminares de las pesquisas realizadas y el diagnóstico temprano de enfrentamiento al COVID-19. También se exponen los requisitos utilizados para el empleo efectivo de las pesquisas elaboradas por el equipo básico de salud (EBS) del Consultorio Médico de la Familia (CMF), junto a la docente y estudiantes de Medicina. Método: Se siguió el método histórico-lógico, con apoyo en la técnica de revisión documental. Se consultaron los partes diarios publicados por el Ministerio de Salud Pública (MINSAP) correspondientes a los días que abarca el estudio, entre marzo - mayo del 2020, disponibles en el sitio web: Infomed. Además se confeccionaron modelos de control y seguimiento, tablas y gráficos para explicar la situación del área de salud del Consultorio Médico en el período que se analiza. Conclusiones: La aplicación efectiva de las pesquisas activas permitió la prevención, identificación e ingreso temprano de los casos en sus diferentes variantes y la baja mortalidad en el área del consultorio a consecuencia del coronavirus. Incidió en estos resultados la incorporación de los estudiantes de Medicina. Se constató la significación de la exploración clínica unida a la epidemiológica y de la congruencia con las evidencias científicas disponibles. Palabras clave: Consultorio Médico de la Familia, estudiantes de Medicina, Pesquisa Activa, COVID-19, peculiaridades.

Introducción: La simulación como herramienta docente se está estableciendo como una prioridad en los currículos de nuestra especialidad en determinados países, principalmente anglosajones, y cada vez se están desarrollando escenarios más sofisticados y completos. Métodos: Se ha fomentado la creación de un equipo multidisciplinar con profesores de universidad, estudiantes de Medicina y médicos con el objetivo de mejorar la docencia del Grado en Medicina y valorar su potencial exportación a la formación especializada en Cirugía Cardiovascular. Resultados: Los alumnos de Medicina participantes demostraron una clara mejoría en la asimilación de información, así como en sus habilidades clínico-prácticas, conforme se fueron estableciendo escenarios de simulación. Del mismo modo, esta herramienta permitió una evaluación objetiva tanto de los resultados in situ como de la evolución temporal de los mismos. Conclusiones: Dado el rendimiento positivo en estudiantes de Medicina, y debido a la cada vez mayor dificultad en la formación de residentes en nuestros hospitales (cuestiones ético-legales, escasez de tiempo de formación, complejidad de casos), se debería plantear la creación de un grupo de Simulación a nivel nacional para valorar la inclusión de la misma en el currículo de la especialidad.

The inflammatory response in the central nervous system involves activated microglia. Under normal conditions they remove damaged neurons by phagocytosis. On the other hand, neurodegenerative diseases are thought to involve chronic microglia activation resulting in release of excess glutamate, proinflammatory cytokines and reactive oxygen species, leading to neuronal death. System xC- cystine/glutamate antiporter (SXC), a sodium independent heterodimeric transporter found in microglia and astrocytes in the CNS, imports cystine into the cell and exports glutamate. SXC has been shown to be upregulated in neurodegenerative diseases including multiple sclerosis, ALS, neuroAIDS Parkinson's disease and Alzheimer's disease. Consequently, SXC inhibitors could be of use in the treatment of diseases characterized by neuroinflammation and glutamate excitotoxicity. We report on the optimization of a primary microglia-based assay to screen for SXC inhibitors. Rat primary microglia were activated using lipopolysaccharides (LPS) and glutamate release and cystine uptake were monitored by fluorescence and radioactivity respectively. LPS-induced glutamate release increased with increasing cell density, time of incubation and LPS concentration. Conditions to screen for SXC inhibitors were optimized in 96-well format and subsequently used to evaluate SXC inhibitors. Known SXC inhibitors sulfasalazine, S-4CPG and erastin blocked glutamate release and cystine uptake while R-4CPG, the inactive enantiomer of S-4CPG, failed to inhibit glutamate release or cystine transport. In addition, several erastin analogs were evaluated using primary microglia and found to have EC50 values in agreement with previous studies using established cell lines.

It remains unclear to what extent neurodevelopmental disorder (NDD) risk genes retain functions into adulthood and how they may influence disease phenotypes. SYNGAP1 haploinsufficiency causes a severe NDD defined by autistic traits, cognitive impairment, and epilepsy. To determine if this gene retains therapeutically-relevant biological functions into adulthood, we performed a gene restoration technique in a mouse model for SYNGAP1 haploinsufficiency. Adult restoration of SynGAP protein improved behavioral and electrophysiological measures of memory and seizure. This included the elimination of interictal events that worsened during sleep. These events may be a biomarker for generalized cortical dysfunction in SYNGAP1 disorders because they also worsened during sleep in the human patient population. We conclude that SynGAP protein retains biological functions throughout adulthood and that non-developmental functions may contribute to disease phenotypes. Thus, treatments that target debilitating aspects of severe NDDs, such as medically-refractory seizures and cognitive impairment, may be effective in adult patients.

Astrocyte dysfunction and excessive activation of glutamatergic systems have been implicated in a number of neurologic disorders, including periventricular leukomalacia (PVL) and cerebral palsy (CP). However, the role of chorioamnionitis on glutamate homeostasis in the fetal and neonatal brains is not clearly understood. We have previously shown that intrauterine endotoxin administration results in intense microglial ‘activation’ and increased pro-inflammatory cytokines in the periventricular region (PVR) of the neonatal rabbit brain. In this study, we assessed the effect of maternal inflammation on key components of the glutamate pathway and its relationship to astrocyte and microglial activation in the fetal and neonatal New Zealand white rabbit brain. We found that intrauterine endotoxin exposure at gestational day 28 (G28) induced acute and prolonged glutamate elevation in the PVR of fetal (G29, 1 day post-injury) and postnatal day 1 (PND1, 3 days post-injury) brains along with prominent morphological changes in the astrocytes (soma hypertrophy and retracted processes) in the white matter tracts. There was a significant increase in glutaminase and N-Methyl-d-Aspartate receptor (NMDAR) NR2 subunit expression along with decreased glial L-glutamate transporter 1 (GLT-1) in the PVR at G29, that would promote acute dysregulation of glutamate homeostasis. This was accompanied with significantly decreased TGF-β1 at PND1 in CP kits indicating ongoing neuroinflammation. We also show for the first time that glutamate carboxypeptidase II (GCPII) was significantly increased in the activated microglia at the periventricular white matter area in both G29 and PND1 CP kits. This was confirmed by in vitro studies demonstrating that LPS activated primary microglia markedly upregulate GCPII enzymatic activity. These results suggest that maternal intrauterine endotoxin exposure results in early onset and long-lasting dysregulation of glutamate homeostasis, which may be mediated by impaired astrocyte function and GCPII upregulation in activated microglia.

Glutamate carboxypeptidase II (GCP-II) is a brain metallopeptidase that hydrolyzes the abundant neuropeptide N-acetyl-aspartyl-glutamate (NAAG) to NAA and glutamate. Small molecule GCP-II inhibitors increase brain NAAG, which activates mGluR3, decreases glutamate, and provide therapeutic utility in a variety of preclinical models of neurodegenerative diseases wherein excess glutamate is presumed pathogenic. Unfortunately no GCP-II inhibitor has advanced clinically, largely due to their highly polar nature resulting in insufficient oral bioavailability and limited brain penetration. Herein we report a non-invasive route for delivery of GCP-II inhibitors to the brain via intranasal (i.n.) administration. Three structurally distinct classes of GCP-II inhibitors were evaluated including DCMC (urea-based), 2-MPPA (thiol-based) and 2-PMPA (phosphonate-based). While all showed some brain penetration following i.n. administration, 2-PMPA exhibited the highest levels and was chosen for further evaluation. Compared to intraperitoneal (i.p.) administration, equivalent doses of i.n. administered 2-PMPA resulted in similar plasma exposures (AUC0-t, i.n./AUC0-t, i.p. = 1.0) but dramatically enhanced brain exposures in the olfactory bulb (AUC0-t, i.n./AUC0-t, i.p. = 67), cortex (AUC0-t, i.n./AUC0-t, i.p. = 46) and cerebellum (AUC0-t, i.n./AUC0-t, i.p. = 6.3). Following i.n. administration, the brain tissue to plasma ratio based on AUC0-t in the olfactory bulb, cortex, and cerebellum were 1.49, 0.71 and 0.10, respectively, compared to an i.p. brain tissue to plasma ratio of less than 0.02 in all areas. Furthermore, i.n. administration of 2-PMPA resulted in complete inhibition of brain GCP-II enzymatic activity ex-vivo confirming target engagement. Lastly, because the rodent nasal system is not similar to humans, we evaluated i.n. 2-PMPA also in a non-human primate. We report that i.n. 2-PMPA provides selective brain delivery with micromolar concentrations. These studies support intranasal delivery of 2-PMPA to deliver therapeutic concentrations in the brain and may facilitate its clinical development.

The cystine-glutamate antiporter (system xc-) is a Na+-independent amino acid transporter that exchanges extracellular cystine for intracellular glutamate. It is thought to play a critical role in cellular redox processes through regulation of intracellular glutathione synthesis via cystine uptake. In gliomas, system xc- expression is universally up-regulated while that of glutamate transporters down-regulated, leading to a progressive accumulation of extracellular glutamate and excitotoxic cell death of the surrounding non-tumorous tissue. Additionally, up-regulation of system xc- in activated microglia has been implicated in the pathogenesis of several neurodegenerative disorders mediated by excess glutamate. Consequently, system xc- is a new drug target for brain cancer and neuroinflammatory diseases associated with excess extracellular glutamate. Unfortunately no potent and selective small molecule system xc- inhibitors exist and to our knowledge, no high throughput screening (HTS) assay has been developed to identify new scaffolds for inhibitor design. To develop such an assay, various neuronal and non-neuronal human cells were evaluated as sources of system xc-. Human glioma cells were chosen based on their high system xc- activity. Using these cells, [14C]-cystine uptake and cystine-induced glutamate release assays were characterized and optimized with respect to cystine and protein concentrations and time of incubation. A pilot screen of the LOPAC/NINDS libraries using glutamate release demonstrated that the logistics of the assay were in place but unfortunately, did not yield meaningful pharmacophores. A larger, HTS campaign using the 384-well cystine-induced glutamate release as primary assay and the 96-well 14C-cystine uptake as confirmatory assay is currently underway. Unexpectedly, we observed that the rate of cystine uptake was significantly faster than the rate of glutamate release in human glioma cells. This was in contrast to the same rates of cystine uptake and glutamate release previously reported in normal human fibroblast cells.

Ceramide is a bioactive lipid that plays an important role in stress responses leading to apoptosis, cell growth arrest and differentiation. Ceramide production is due in part to sphingomyelin hydrolysis by sphingomyelinases. In brain, neutral sphingomyelinase 2 (nSMase2) is expressed in neurons and increases in its activity and expression have been associated with pro-inflammatory conditions observed in Alzheimer's disease, multiple sclerosis and human immunodeficiency virus (HIV-1) patients. Increased nSMase2 activity translates into higher ceramide levels and neuronal cell death, which can be prevented by chemical or genetic inhibition of nSMase2 activity or expression. However, to date, there are no soluble, specific and potent small molecule inhibitor tool compounds for in vivo studies or as a starting point for medicinal chemistry optimization. Moreover, the majority of the known inhibitors were identified using bacterial, bovine or rat nSMase2. In an attempt to identify new inhibitor scaffolds, two activity assays were optimized as screening platform using the recombinant human enzyme. First, active hits were identified using a fluorescence-based high throughput compatible assay. Then, hits were confirmed using a 14C sphingomyelin-based direct activity assay. Pharmacologically active compounds and approved drugs were screened using this strategy which led to the identification of cambinol as a novel uncompetitive nSMase2 inhibitor (Ki = 7 μM). The inhibitory activity of cambinol for nSMase2 was approximately 10-fold more potent than for its previously known target, silence information regulator 1 and 2 (SIRT1/2). Cambinol decreased tumor necrosis factor-α or interleukin-1 β-induced increases of ceramide and cell death in primary neurons. A preliminary study of cambinol structure and activity allowed the identification of the main structural features required for nSMase2 inhibition. Cambinol and its analogs may be useful as nSMase2 inhibitor tool compounds to prevent ceramide-dependent neurodegeneration.

Resumen: La ciprofloxacina es un antibiótico de importancia crítica para la salud humana. El aumento de la resistencia de Escherichia coli a ciprofloxacina es un problema de salud pública global por su importancia en el tratamiento de infecciones urinarias complicadas y otras infecciones graves; sin embargo, su prescripción es alta en el caribe colombiano. El objetivo fue determinar la tendencia de resistencia de E. coli a ciprofloxacina en un hospital colombiano de alta complejidad. A partir de reportes de antibiogramas, los aislados fueron categorizados según los criterios del Instituto de Normas Clínicas y de Laboratorio de los Estados Unidos para cada año estudiado; se calcularon proporciones y se exploraron diferencias en la sensibilidad con pruebas χ2. Se utilizó la prueba de Cochran-Armitage para evaluar la tendencia de la resistencia. Valores de p ≤ 0,05 se consideraron significativos. Se analizaron 6.848 aislados, encontrándose una resistencia de 49,31%. Según el origen, la resistencia más alta fue en muestras comunitarias (51,96% - IC95%: 50,51; 53,41), y por tipo de muestra, en piel y tejidos (61,76% - IC95%: 56,96; 66,35) y orina (48,97% - IC95%: 47,71; 50,23). Se halló una tendencia al aumento en la resistencia por año (p < 0,0001), en muestras comunitarias (p = 0,0002) y en orina (p < 0,0001). La resistencia a ciprofloxacina es alta y tiende al aumento en comunidad y en orina, superando el límite establecido para su uso a nivel ambulatorio, lo que es preocupante por la alta prescripción de fluoroquinolonas en la localidad.

Surgical resection remains a definitive treatment for prostate cancer. Yet, prostate cancer surgery is performed without image guidance for tumor margin, extension beyond the capsule and lymph node positivity, and without verification of other occult metastases in the surgical field. Recently, several imaging systems have been described that exploit near-infrared (NIR) fluorescent light for sensitive, real-time detection of disease pathology intraoperatively. In this study, we describe a high-affinity (9 nM), single nucleophile-containing, small molecule specific for the active site of the enzyme PSMA. We demonstrate production of a tetra-sulfonated heptamethine indocyanine NIR fluorescent derivative of this molecule using a high-yield LC/MS purification strategy. Interestingly, NIR fluorophore conjugation improves affinity over 20-fold, and we provide mechanistic insight into this observation. We describe the preparative production of enzymatically active PSMA using a baculovirus expression system and an adenovirus that co-expresses PSMA and GFP. We demonstrate sensitive and specific in vitro imaging of endogenous and ectopically expressed PSMA in human cells and in vivo imaging of xenograft tumors. We also discuss chemical strategies for improving performance even further. Taken together, this study describes nearly complete preclinical development of an optically based small-molecule contrast agent for image-guided surgery.

Abstract Background Salmonellosis is a major cause of morbidity and mortality and one of the most frequent etiologies of diarrhea in the world. Mortality due to Salmonellosis in Latin America still poorly understood, and there is a lack of studies that evaluate resistance and clinical manifestations. The aims of this study were to characterize patients infected with Salmonella spp. seen in a university hospital in Colombia between 2012 and 2021, to evaluate trends in antibiotic resistance and to determine the proportion of overall mortality and related factors. Methods Retrospective observational study. All patients with microbiological diagnosis of Salmonella spp. were included. The sociodemographic, clinical and microbiological characteristics were described, and the proportion of antibiotic resistant isolates per year was estimated. The prevalence of mortality according to age groups was calculated. Log binomial regression models were used to establish factors associated with mortality. Results Five hundred twenty-two patients were analyzed. Salmonellosis accounted for 0.01% of all medical consultations. The median age was 16 years old. The most common clinical presentation was gastroenteric syndrome (77.1%) and symptoms included diarrhea (79.1%), fever (66.7%), abdominal pain (39.6%) and vomiting (35.2%). Of the Salmonella spp. isolates, 78.2% were not classified, 19.1% corresponded to non-typhoidal Salmonella and 2.7% to Salmonella typhi. Mortality occurs in 4.02% of the patients and was higher in patients with hematologic malignancy (11.6%). When analyzing by age group, the proportion of deaths was 2.8% in patients aged 15 years or younger, while in those older than 15 years it was 5.4%. Factors associated to mortality where bacteremia (aPR = 3.41 CI95%: 1.08—10.76) and to require treatment in the ICU (aPR = 8.13 CI95%: 1.82—37.76). In the last 10 years there has been a steady increase in resistance rates to ciprofloxacin, ampicillin, ampicillin/sulbactam and ceftriaxone, reaching rates above 60% in recent years. Conclusions Despite improved availability of antibiotics for the treatment of salmonellosis in the past decades, mortality due to salmonellosis continues occurring in children and adults, mainly in patients with hematological malignancies and bacteremia. Antibiotic resistance rates have increased significantly over the last 10 years. Public health strategies for the control of this disease should be strengthened, especially in vulnerable populations.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can infect human cells by first attaching to the ACE-2 receptor via its receptor-binding domain (RBD) in the spike protein. Here, we report the influence of N-glycosylation sites of the RBD and the membrane (M) protein on IgG antibody binding in serum samples from patients infected with the original SARS-CoV-2 strain in Germany. The RBDs of the wildtype, alpha, beta, gamma, and kappa variants expressed in HEK293S GnTI− cells were all N-glycosylated at Asn331, Asn334, Asn343, and Asn360 or Asn370, whereas the M-protein was glycosylated at Asn5. An ELISA using a coated RBD and probed with anti-RBD IgG antibodies gave a sensitivity of 96.3% and a specificity of 100% for the wildtype RBD, while the sensitivity decreased by 5% to 10% for the variants of concern, essentially in the order of appearance. Deglycosylation of the wildtype RBD strongly reduced antibody recognition by ~20%, considering the mean of the absorbances recorded for the ELISA. This effect was even stronger for the unglycosylated RBD expressed in Escherichia coli, suggesting structural changes affecting epitope recognition. Interestingly, the N-glycosylated M-protein expressed in HEK293S GnTI− cells gave good sensitivity (95%), which also decreased to 65% after deglycosylation, and selectivity (100%). In conclusion, N-glycosylation of the M-protein, the RBD, and most likely the spike protein are important for proper antibody binding and immunological assays, whereas the type of N-glycosylation is less relevant.

En atención del auge de los sistemas de cumplimiento, denominados compliance y su paulatina inserción en los diferentes ordenamientos jurídicos, el presente trabajo busca explorar la existencia de un sistema de compliance tributario en Colombia.

En atención al auge de los sistemas de cumplimiento surgidos en las corporaciones en el mundo, denominados compliance y su paulatina inserción en los diferentes ordenamientos jurídicos, el presente trabajo busca explorar las bases filosóficas y jurídicas de su creación como criterio de funcionamiento empresarial y social en la realidad actual.