Endocrinologic, neurologic, and visual morbidity after treatment for craniopharyngioma

Craniopharyngiomas are locally aggressive tumors which typically are focused in the sellar and suprasellar region near a number of critical neural and vascular structures mediating endocrinologic, behavioral, and visual functions. The present study aims to summarize and compare the published literature regarding morbidity resulting from treatment of craniopharyngioma. We performed a comprehensive search of the published English language literature to identify studies publishing outcome data of patients undergoing surgery for craniopharyngioma. Comparisons of the rates of endocrine, vascular, neurological, and visual complications were performed using Pearson’s chi-squared test, and covariates of interest were fitted into a multivariate logistic regression model. In our data set, 540 patients underwent surgical resection of their tumor. 138 patients received biopsy alone followed by some form of radiotherapy. Mean overall follow-up for all patients in these studies was 54 ± 1.8 months. The overall rate of new endocrinopathy for all patients undergoing surgical resection of their mass was 37% (95% CI = 33–41). Patients receiving GTR had over 2.5 times the rate of developing at least one endocrinopathy compared to patients receiving STR alone or STR + XRT (52 vs. 19 vs. 20%, χ2P < 0.00001). On multivariate analysis, GTR conferred a significant increase in the risk of endocrinopathy compared to STR + XRT (OR = 3.45, 95% CI = 2.05–5.81, P < 0.00001), after controlling for study size and the presence of significant hypothalamic involvement. There was a statistical trend towards worse visual outcomes in patients receiving XRT after STR compared to GTR or STR alone (GTR = 3.5% vs. STR 2.1% vs. STR + XRT 6.4%, P = 0.11). Given the difficulty in obtaining class 1 data regarding the treatment of this tumor, this study can serve as an estimate of expected outcomes for these patients, and guide decision making until these data are available

Acute and chronic effects of the incretin enhancer vildagliptin in insulin-resistant rats

The enzyme dipeptidyl peptidase-IV (DPP-4) inactivates the incretin hormone glucagon-like peptide-1 (GLP-1). Because GLP-1 has therapeutic effects in patients with type 2 diabetes, but its potential is limited by a short half-life, DPP-4 inhibition is a promising approach to diabetes treatment. This study examined acute (single dose) and chronic (once-a-day dosing for 21 days) effects of the DPP-4 inhibitor vildagliptin (0.03-10 mg/kg) on plasma DPP-4 activity, intact GLP- 1, glucose, and insulin after an oral glucose load in insulin-resistant Zucker fatty rats and acute effects in mildly insulin-resistant high-fat-fed normal rats. A single oral dose of vildagliptin in Zucker rats produced a rapid and dose-related inhibition of DPP-4: the minimum effective dose (MED) was 0.3 mg/kg. Glucose-induced increases of intact GLP- 1 were greatly but similarly enhanced by vildagliptin at doses >= 0.3 mg/kg. Postload glucose excursions decreased, and the insulinogenic index (Delta insulin/Delta glucose at 10 min) increased, with an MED of 0.3 mg/kg and a maximally effective dose of 3 mg/kg. The effects of vildagliptin after chronic treatment were nearly identical to those of acute administration, and vildagliptin had no effect on body weight. In fat-fed normal rats, vildagliptin (3 mg/kg) also decreased postload glucose excursions and increased the insulinogenic index, but these effects were smaller than those in Zucker rats. Thus, vildagliptin is an orally effective incretin enhancer with antihyperglycemic activity in insulin-resistant rats and exhibits no tachyphylaxis. GLP-1-mediated augmentation of glucose-induced insulin release seems to make the major contribution to the antidiabetic properties of vildagliptin

The effect of 1,3-diaryl-[1H]-pyrazole-4-acetamides on glucose utilization in ob/ob mice

This article provides evidence of a new class of compounds, 1,3-diaryl-[1H]-pyrazole-4-acetamides, initially identified from their ability to increase glucose transport in an adipocyte and muscle cell line and ultimately demonstrating dramatic glucose lowering in ob/ob Mice, a diabetic animal model. The lead compound, 1, possessed some behavioral-like effects which were removed by structural variation during the course of this investigation. Specifically, 11 g (RI = meta-CF3, Ar2 = 4 ' biphenyl, R3 = diethylamide) illustrated the potency of this series with ED50 values for glucose lowering in ob/ob mice of 3.0 mg/kg/day. Concomitant with its effect on glucose lowering, 11g also caused a 50% reduction in insulin levels consistent with an agent that increases whole body insulin sensitivity. 11g showed favorable pharmacokinetic data with acceptable absorption, negligible metabolism, and good duration of action. 11g demonstrated no appreciable adipogenic effect through PPAR gamma agonism, a characteristic of the thiazolidinediones (TZD), and so represents a potentially new class of agents for the treatment of diabetes

Extracellular chaperones and proteostasis

There is a family of currently untreatable serious human diseases that arise from the inappropriate misfolding and aggregation of extracellular proteins. At present our understanding of mechanisms that operate to maintain proteostasis in extracellular body fluids is limited but has significantly advanced with the discovery of a small but growing family of constitutively secreted extracellular chaperones (ECs). The available evidence strongly suggests that these chaperones act as both sensors and disposal-mediators of misfolded proteins in extracellular fluids, thereby normally protecting us from disease pathologies. It is critically important to further increase our understanding of the mechanisms that operate to effect extracellular proteostasis, as this will be essential knowledge upon which to base the development of effective therapies for some of the world\u27s most debilitating, costly and intractable diseases