5-HT3 Receptor-independent Inhibition of the Depolarization-induced 86Rb Efflux from Human Neuroblastoma Cells,TE671, by Ondansetron

The 5-HT₃-receptor antagonist, ondansetron, has been shown to have positive effects in selected in-vivo models of memory impairment and anxiety. The exact mechanisms underlying such bioactivities are unknown. In the present work, an ⁸⁶Rb efflux bioassay was used to show that ondansetron has a unique ability to block voltage-gated potassium channels in TE671 human neuroblastoma cells. This intrinsic potassium-channel-blocking (KCB) property is relatively weak (IC50 20 (M), but is not shared by other 5-HT₃-receptor ligands including zatosetron, MDL 72222, LY 278, 584, zacopride, 1-phenylbiguanide, and ICS 205–930 (tropisetron). Pre-incubation of the target neuroblastoma cells with several 5-HT-receptor ligands including 5-hydroxytryptamine, 8-OH-DPAT, ketanserin, 2-methyl-5-HT, as well as a number of potent 5-HT₃ agonists and antagonists and two selective neurotoxins, failed to abolish the KCB action of ondansetron. A preliminary structure-activity relationship analysis indicates that the KCB activity of ondansetron is almost entirely attributable to its structural nucleus, 2,3-dihyro-9-methyl-4(lH)-carbazolone. It is hypothesized that the KCB action of ondansetron is mediated through receptors other than 5-HT₃ receptors. The KCB activity of ondansetron may be a significant factor in the in-vivo cognition-enhancing activities of this compound, conceivably due to depolarization of the hippocampal synaptic membranes and a consequent augmentation of neurotransmission.     

Vaccine-associated paralytic poliomyelitis in a patient with MHC class II deficiency.

Vaccine-associated paralytic poliomyelitis (VAPP) is a rare complication of oral polio vaccine. We describe a fatal case of VAPP in an 8-month-old boy with Major Histocompatibility Class II deficiency. The isolated poliovirus was a Sabin type 2-type 1 recombinant that showed 1.4% VP1 divergence from Sabin type 2.     

Impact of Intracranial Pressure Monitor–Guided Therapy on Neurologic Outcome After Spontaneous Nontraumatic Intracranial Hemorrhage

Objectives: Intracranial pressure (ICP) monitors have been used in some patients with spontaneous intracranial hemorrhage (ICH) to provide information to guide treatment without clear evidence for its use in this population. We assessed the impact of ICP monitor placement, including external ventricular drains and intraparenchymal monitors, on neurologic outcome in this population.Materials and MethodsIn this secondary analysis of the Minimally Invasive Surgery Plus Alteplase for Intracerebral Hemorrhage Evacuation III trial, the primary outcome was poor outcome (modified Rankin Scale score 4-6) and the secondary outcome was death, at 1 year from onset. We compared outcomes in patients with or without an ICP monitor using unadjusted and adjusted logistic regression models. The analyses were repeated in a balanced cohort created with propensity score matching.ResultsSeventy patients underwent ICP monitor placement and 424 did not. Poor outcome was seen in 77.1% of patients in the ICP-monitor subgroup compared with 53.8% in the no-monitor subgroup (p<0.001). Of patients in the ICP-monitor subgroup, 31.4% died, compared with 21.0% in the no-monitor subgroup (p=0.053). In multivariate models, ICP monitor placement was associated with a >2-fold greater risk of poor outcome (odds ratio 2.76, 95% CI 1.30–5.85, p=0.008), but not with death (p=0.652). Our findings remained consistent in the propensity score-matched cohort.ConclusionThese results question whether ICP monitor–guided therapy in patients with spontaneous nontraumatic ICH improves outcome. Further work is required to define the causal pathway and improve identification of patients that might benefit from invasive ICP monitoring.     

The burden of hypoglycemia on healthcare utilization, costs, and quality of life among type 2 diabetes mellitus patients

ObjectiveTo assess the burden of hypoglycemia among type 2 diabetes patients on antidiabetic drugs with or without use of insulin.Research Design and MethodsWe used mail surveys, administrative claims data, and enrollment information from a sample of adult commercial health plan enrollees (n = 813) with type 2 diabetes during a 12-month period. Patients' experience of hypoglycemia, its impact on patient perspectives and healthcare utilization were the outcomes evaluated.ResultsA greater percentage of patients in the antidiabetic with insulin cohort reported experiencing hypoglycemia compared with patients from sulfonylurea (SU) without insulin and non-SU without insulin cohorts (50% vs. 21% and 12%, respectively; p < 0.01 for both comparisons). While 71% of the sample reported experiencing hypoglycemic symptoms with 28% confirmed by low blood glucose levels, only 10% of the patients had evidence of hypoglycemia event in the claims database. Patients with confirmed hypoglycemia had the highest Hypoglycemia Fear Survey behavior score (8) and worry subscale score (14). Significant differences were noted between the confirmed hypoglycemia and no hypoglycemia cohorts for the 12-item Short Form Health Survey's Mental Component Score (p < 0.001) and Physical Component Score (p = 0.002), and for the EQ-5D index (p < 0.001). Diabetes-related annualized mean total healthcare costs were significantly higher for confirmed hypoglycemia vs. no hypoglycemia cohorts (p = 0.004).ConclusionsSymptomatic hypoglycemia is a more significant burden among type 2 diabetes patients treated with antidiabetic drugs than is estimated by administrative claims data and needs to be considered when choosing therapy.     

Hypertriglyceridemia is associated with insulin levels in adult cystic fibrosis patients

BackgroundRecent studies have identified hypertriglyceridemic cystic fibrosis patients (CF-TG). However, whether hypertriglyceridemia is associated with an altered metabolic profile remains unknown.ObjectiveTo characterize CF-TG and determine whether triglycerides (TG) levels are associated with metabolic alterations.Methods210 adult CF subjects from the Montreal Cystic Fibrosis Cohort without known diabetes were included in the analysis. All subjects underwent an OGTT to assess glucose tolerance, insulin secretion (insulin AUC) and insulin sensitivity (Stumvoll index). Fasting lipid profiles, pulmonary function (%FEV₁) and BMI were determined. Hypertriglyceridemia (TG > 1.7 mmol/L) was observed in 20 CF patients. These subjects were matched for age, sex and glucose tolerance category with 20 CF patients (CF-normal-TG) and 20 healthy controls that had TG levels below 1.7 mmol/L. Pearson correlations were performed in the complete study sample (n = 210) to examine the associations between TG levels and other parameters.ResultsThe prevalence of hypertriglyceridemia was 9.5%. Compared to CF-normal-TG, CF-TG subjects displayed significantly higher %FEV_1, insulin AUC (AUC_0–120, AUC_0–30, AUC_30–120), cholesterol levels and a higher ratio of total cholesterol to HDL-cholesterol. Pearson analysis demonstrated that TG levels were associated with BMI, %FEV₁, fasting insulin, insulin AUC_0–120 and AUC_30–120, Stumvoll index, cholesterol levels and the ratio of total cholesterol to HDL-cholesterol. All these correlations remained significant after correction for BMI except %FEV₁.ConclusionTG levels are associated with a mild alteration of the metabolic profile. Whether these changes will increase the long-term risk of CF patients in developing cardiometabolic complications remains to be investigated.     

Synthesis and anticholinesterase activity of new substituted benzo[d]oxazole‐based derivatives

A series of novel benzo[d]oxazole derivatives ( 6a–n ) have been synthesized and biologically evaluated as potential inhibitors of acetylcholinesterases (AChE) and butyrylcholinesterase (BChE). The chemical structures of all final compounds were confirmed by spectroscopic methods. In vitro studies showed that most of the synthesized compounds are potent acetylcholinesterase and butyrylcholinesterase inhibitors. Among them, compounds 6a and 6j strongly inhibited AChE and BChE activities with IC₅₀ values of 1.03–1.35 and 6.6–8.1 μm , respectively. Docking studies also provided the binding modes of action and identified hydrophobic pi forces as the main interaction.