Cell surface macromolecules such as receptors and ion channels serve as the interface link between the cytoplasm and the extracellular region. Their density, distribution, and clustering are key spatial features influencing effective and proper physical and biochemical cellular responses to many regulatory signals. In this study, the effect of plasma-membrane receptor clustering on local cell mechanics was obtained from maps of interaction forces between antibody-conjugated atomic force microscope tips and a specific receptor, a vascular endothelial growth factor (VEGF) receptor. The technique allows simultaneous measurement of the real-time motion of specific macromolecules and their effect on local rheological properties like elasticity. The clustering was stimulated by online additions of VEGF, or antibody against VEGF receptors. VEGF receptors are found to concentrate toward the cell boundaries and cluster rapidly after the online additions commence. Elasticity of regions under the clusters is found to change remarkably, with order-of-magnitude stiffness reductions and fluidity increases. The local stiffness reductions are nearly proportional to receptor density and, being concentrated near the cell edges, provide a mechanism for cell growth and angiogenesis.

SUMMARYPurpose: Compelling evidence supports the presence of P450 enzymes (CYPs) in the central nervous system (CNS). However, little information is available on the localization and function of CYPs in the drug-resistant epileptic brain. We have evaluated the pattern of expression of the specific enzyme CYP3A4 and studied its co-localization with MDR1. We also determined whether an association exists between CYP3A4 expression and cell survival. Methods: Brain specimens were obtained from eight patients undergoing resection to relieve drug-resistant seizures or to remove a cavernous angioma. Each specimen was partitioned for either immunostaining or primary culture of human endothelial cells and astrocytes. Immunostaining was performed using anti-CYP3A4, MDR1, GFAP, or NeuN antibodies. High performance liquid chromatography-ultraviolet (HPLC-UV) analysis was used to quantify carbamazepine (CBZ) metabolism by these cells.CYP3A4 expression was correlated to DAPI) condensation, a marker of cell viability. Human embryonic kidney (HEK) cells were transfected with 4¢,6-diamidino-2-phenylindole (CYP3A4 to further evaluate the link between CYP3A4 levels, CBZ metabolism, and cell viability. Key Findings: CYP3A4 was expressed by blood-brain barrier (BBB) endothelial cells and by the majority of neurons (75 ± 10%). Fluorescent immunostaining showed coexpression of CYP3A4 and MDR1 in endothelial cells and neurons. CYP3A4 expression inversely correlated with DAPI nuclear condensation. CYP3A4 overexpression in HEK cells conferred resistance to cytotoxic levels of carbamazepine. CYP3A4 levels positively correlated with the amount of CBZ metabolized. Significance: CYP3A4 brain expression is not only associated with drug metabolism but may also represent a cytoprotective mechanism. Coexpression of CYP3A4 and MDR1 may be involved in cell survival in the diseased brain.

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It has long been held that chronic seizures cause blood-brain barrier (BBB) damage. Recent studies have also demonstrated that BBB damage triggers seizures. We have used the BBB osmotic disruption procedure (BBBD) to examine the correlation between BBB opening, pattern of white blood cells (WBCs) entry into the brain and seizure occurrence. These findings were compared to results from resected epileptic brain tissue from temporal lobe epilepsy (TLE) patients.We confirmed that a successful BBB osmotic opening (BBBD) leads to the occurrence of acute epileptiform discharges. Electroencephalography (EEG) and time-joint frequency analysis reveal EEG slowing followed by an increase in the 10-20 Hz frequency range. Using green fluorescent protein (GFP)-labeled WBCs (GFP-WBCs) suspended in Evans Blue we found that, at time of BBB-induced epileptiform discharges, WBCs populated the perivascular space of a leaky BBB. Similar results were obtained at time of pilocarpine seizure. No frank WBCs extravasation in the brain parenchyma was observed.In TLE brain specimens, CD45-positive leukocytes were detected only in the vascular and perivascular spaces while albumin and IgG extravasates were parenchymal. The pattern was similar to those observed in rats.Our data suggest that neither acute-induced nor chronic seizures correlate with WBC brain parenchymal migration while albumin and IgG brain leakage is a hallmark of acute and chronic seizures.

; for the PCORnet Bariatric Study Collaborative IMPORTANCE Bariatric surgery can lead to substantial improvements in type 2 diabetes (T2DM), but outcomes vary across procedures and populations. It is unclear which bariatric procedure has the most benefits for patients with T2DM. OBJECTIVE To evaluate associations of bariatric surgery with T2DM outcomes. DESIGN, SETTING, AND PARTICIPANTS This cohort study was conducted in 34 US health system sites in the National Patient-Centered Clinical Research Network Bariatric Study. Adult patients with T2DM who had bariatric surgery between January 1, 2005, and September 30, 2015, were included. Data analysis was conducted from April 2017 to August 2019. INTERVENTIONS Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG). MAIN OUTCOME AND MEASURES Type 2 diabetes remission, T2DM relapse, percentage of total weight lost, and change in glycosylated hemoglobin (hemoglobin A 1c). RESULTS A total of 9710 patients were included (median [interquartile range] follow-up time, 2.7 [2.9] years; 7051 female patients [72.6%]; mean [SD] age, 49.8 [10.5] years; mean [SD] BMI, 49.0 [8.4]; 6040 white patients [72.2%]). Weight loss was significantly greater with RYGB than SG at 1 year (mean difference, 6.3 [95% CI, 5.8-6.7] percentage points) and 5 years (mean difference, 8.1 [95% CI, 6.6-9.6] percentage points). The T2DM remission rate was approximately 10% higher in patients who had RYGB (hazard ratio, 1.10 [95% CI, 1.04-1.16]) than those who had SG. Estimated adjusted cumulative T2DM remission rates for patients who had RYGB and SG were 59.2% (95% CI, 57.7%-60.7%) and 55.9% (95% CI, 53.9%-57.9%), respectively, at 1 year and 86.1% (95% CI, 84.7%-87.3%) and 83.5% (95% CI, 81.6%-85.1%) at 5 years postsurgery. Among 6141 patients who experienced T2DM remission, the subsequent T2DM relapse rate was lower for those who had RYGB than those who had SG (hazard ratio, 0.75 [95% CI, 0.67-0.84]). Estimated relapse rates for those who had RYGB and SG were 8.4% (95% CI, 7.4%-9.3%) and 11.0% (95% CI, 9.6%-12.4%) at 1 year and 33.1% (95% CI, 29.6%-36.5%) and 41.6% (95% CI, 36.8%-46.1%) at 5 years after surgery. At 5 years, compared with baseline, hemoglobin A 1c was reduced 0.45 (95% CI, 0.27-0.63) percentage points more for patients who had RYGB vs patients who had SG. CONCLUSIONS AND RELEVANCE In this large multicenter study, patients who had RYGB had greater weight loss, a slightly higher T2DM remission rate, less T2DM relapse, and better long-term glycemic control compared with those who had SG. These findings can help inform patient-centered surgical decision-making.