Endoscopic third ventriculostomy versus ventriculoperitoneal shunt in pediatric and adult population: a systematic review and meta-analysis

Neurosurgical Review - Treatment options for hydrocephalus include endoscopic third ventriculostomy (ETV) and ventriculoperitoneal shunt (VPS). Some ambiguity remains regarding indications, safety,...     

Novel Stable Isotope Analyses Demonstrate Significant Rates of Glucose Cycling in Mouse Pancreatic Islets

A polymorphism located in the G6PC2 gene, which encodes an islet-specific glucose-6-phosphatase catalytic subunit, is the most important common determinant of variations in fasting blood glucose (FBG) levels in humans. Studies of G6pc2 knockout (KO) mice suggest that G6pc2 represents a negative regulator of basal glucose-stimulated insulin secretion (GSIS) that acts by hydrolyzing glucose-6-phosphate (G6P), thereby reducing glycolytic flux. However, this conclusion conflicts with the very low estimates for the rate of glucose cycling in pancreatic islets, as assessed using radioisotopes. We have reassessed the rate of glucose cycling in pancreatic islets using a novel stable isotope method. The data show much higher levels of glucose cycling than previously reported. In 5 mmol/L glucose, islets from C57BL/6J chow-fed mice cycled ∼16% of net glucose uptake. The cycling rate was further increased at 11 mmol/L glucose. Similar cycling rates were observed using islets from high fat–fed mice. Importantly, glucose cycling was abolished in G6pc2 KO mouse islets, confirming that G6pc2 opposes the action of the glucose sensor glucokinase by hydrolyzing G6P. The demonstration of high rates of glucose cycling in pancreatic islets explains why G6pc2 deletion enhances GSIS and why variants in G6PC2 affect FBG in humans.     

Post–COVID-19 Syndrome (Long Haul Syndrome): Description of a Multidisciplinary Clinic at Mayo Clinic and Characteristics of the Initial Patient Cohort

ObjectiveTo describe characteristics of a series of patients reporting prolonged symptoms after an infection with coronavirus disease 2019 (COVID-19).Patients and MethodsThis study describes the multidisciplinary COVID-19 Activity Rehabilitation Program, established at Mayo Clinic to evaluate and treat patients with post–COVID syndrome, and reports the clinical characteristics of the first 100 patients receiving evaluation and management during the timeframe of June 1, 2020, and December 31, 2020.ResultsThe cohort consisted of 100 patients (mean age, 45.4±14.2 years; 68% women; mean body mass index, 30.2 kg/m²; presenting a mean of 93 days after infection). Common preexisting conditions were respiratory (23%) and mental health, including depression and/or anxiety (34%). Most (75%) had not been hospitalized for COVID-19. Common presenting symptoms ware fatigue (80%), respiratory complaints (59%), and neurological complaints (59%) followed by subjective cognitive impairment, sleep disturbance, and mental health symptoms. More than one-third of patients (34%) reported difficulties in performing basic activities of daily living. Only 1 in 3 patients had returned to unrestricted work duty at the time of the analysis. For most patients, laboratory and imaging tests showed no abnormalities or were nondiagnostic despite debilitating symptoms. Most patients required physical therapy, occupational therapy, or brain rehabilitation. Face-to-face and virtual care delivery modalities were feasible.ConclusionMost of the patients did not have COVID-19–related symptoms that were severe enough to require hospitalization, were younger than 65 years, and were more likely to be female, and most had no preexisting comorbidities before severe acute respiratory syndrome coronavirus 2 infection. Symptoms including mood disorders, fatigue, and perceived cognitive impairment resulted in severe negative impacts on resumption of functional and occupational activities in patients experiencing prolonged effects.     

Successful allotransplantation of encapsulated islets in pancreatectomized canines for diabetic management without the use of immunosuppression

BACKGROUND: Pancreatic islet transplantation has shown great success in the treatment of diabetic patients. However, the required immunosuppressive therapy exposes patients to serious side effects. METHODS: We have designed a novel five-component/three-membrane capsule and encapsulation system to protect the transplanted islet cells from immune system attack while allowing the influx of molecules and nutrients necessary for cell function/survival and efflux of the desired cellular product, specifically insulin, for making recipients healthy. RESULTS: We transplanted encapsulated canine pancreatic islets into the peritoneal cavity of pancreatectomized canines. Transplantation normalized fasting blood glucose levels in nine out of nine dogs for up to 214 days with a single transplantation. Retransplantation was assessed in three animals and encapsulated islets were effective in providing fasting glycemic control after the initial transplantation had run its course. No immunosuppression or anti-inflammatory therapy was used. CONCLUSION: This advancement in transplantation may lead to an alternative approach for islet transplantation treatment for diabetic patients. This approach may also benefit patients suffering from other hormone deficiency diseases including liver disease and Parkinson's disease.     

An in vitro assessment of bioaccessibility of arsenicals in rice and the use of this estimate within a probabilistic exposure model

In this study, an in vitro synthetic gastrointestinal extraction protocol was used to estimate bioaccessibility of different arsenicals present in 17 rice samples of various grain types that were collected across the United States. The across matrix average for total arsenic was 209 ng/g±153 (\[xmacr]±2σ). The bioaccessibility estimate produced an across matrix average of 61%±19 (\[xmacr]±2σ). The across matrix average concentrations of inorganic arsenic (iAs) and dimethylarsinic acid (DMA) were 81?ng/g±67.7 and 41 ng/g±58.1 (\[xmacr]±2σ), respectively. This distribution of iAs concentrations in rice was combined with the distribution of consumption patterns (from WWEIA) in a Stochastic Human Exposure and Dose Simulator model to estimate population-based exposures. The mean consumption rate for the population as a whole was 15.7 g per day resulting in a 0.98 μg iAs per day exposure. The mean consumption rate for children 1-2 years old was 7 g per day resulting in a 0.48 μg iAs per day exposure. Presystemic biotransformation of DMA in rice was examined using an in vitro assay containing the anaerobic microbiota of mouse cecum. This assay indicated that DMA extracted from the rice was converted to dimethylthioarsinic acid, although a second oxygen-sulfur exchange to produce DMDTA was not observed.