434 research outputs found
A randomized phase 1b cross-over study of the safety of low-dose pioglitazone for treatment of autosomal dominant polycystic kidney disease
Background: Autosomal dominant polycystic kidney disease (ADPKD) is one of the most common monogenetic disorders in humans and is characterized by numerous fluid-filled cysts that grow slowly, resulting in end-stage renal disease in the majority of patients. Preclinical studies have indicated that treatment with low-dose thiazolidinediones, such as pioglitazone, decrease cyst growth in rodent models of PKD.
Methods: This Phase 1b cross-over study compared the safety of treatment with a low dose (15 mg) of the peroxisome proliferator-activated receptor-γ (PPAR-γ) agonist pioglitazone or placebo in PKD patients, with each treatment given for 1 year. The study monitored known side effects of PPAR-γ agonist treatment, including fluid retention and edema. Liver enzymes and risk of hypoglycemia were assessed throughout the study. As a secondary objective, the efficacy of low-dose pioglitazone was followed using a primary assessment of total kidney volume (TKV), blood pressure (BP) and kidney function.
Results: Eighteen patients were randomized and 15 completed both arms. Compared with placebo, allocation to pioglitazone resulted in a significant decrease in total body water as assessed by bioimpedance analysis {mean difference 0.16 Ω [95% confidence interval (CI) 0.24-2.96], P = 0.024} and no differences in episodes of heart failure, clinical edema or change in echocardiography. Allocation to pioglitazone led to no difference in the percent change in TKV of -3.5% (95% CI -8.4-1.4, P = 0.14), diastolic BP and microalbumin:creatinine ratio.
Conclusions: In this small pilot trial in people with ADPKD but without diabetes, pioglitazone 15 mg was found to be as safe as placebo. Larger and longer-term randomized trials powered to assess effects on TKV are needed
How fair versus how long: An integrative theory‐based examination of procedural justice and procedural timeliness
Although studies have linked procedural justice to a range of positive attitudes and behaviors, the focus on justice has neglected other aspects of decision‐making procedures. We explore one of those neglected aspects: procedural timeliness—defined as the degree to which procedures are started and completed within an acceptable time frame. Do employees react to how long a procedure takes, not just how fair it seems to be? To explore that question, we examined the potential effects of procedural timeliness using six theories created to explain the benefits of procedural justice. This integrative theory‐based approach allowed us to explore whether “how long” had unique effects apart from “how fair.” The results of a three‐wave, two‐source field study showed that procedural timeliness had a significant indirect effect on citizenship behavior through many of the theory‐based mechanisms, even when controlling for procedural justice. A laboratory study then replicated those effects while distinguishing procedures that were too fast versus too slow. We discuss the implications of our results for research on fostering citizenship behavior and improving supervisors’ decision‐making procedures
LSD but not lisuride disrupts prepulse inhibition in rats by activating the 5-HT2A receptor
Compounds that activate the 5-HT2A receptor, such as lysergic acid diethylamide (LSD), act as hallucinogens in humans. One notable exception is the LSD congener lisuride, which does not have hallucinogenic effects in humans even though it is a potent 5-HT2A agonist. LSD and other hallucinogens have been shown to disrupt prepulse inhibition (PPI), an operational measure of sensorimotor gating, by activating 5-HT2A receptors in rats.
We tested whether lisuride disrupts PPI in male Sprague–Dawley rats. Experiments were also conducted to identify the mechanism(s) responsible for the effect of lisuride on PPI and to compare the effects of lisuride to those of LSD.
Confirming a previous report, LSD (0.05, 0.1, and 0.2 mg/kg, s.c.) reduced PPI, and the effect of LSD was blocked by pretreatment with the selective 5-HT2A antagonist MDL 11,939. Administration of lisuride (0.0375, 0.075, and 0.15 mg/kg, s.c.) also reduced PPI. However, the PPI disruption induced by lisuride (0.075 mg/kg) was not blocked by pretreatment with MDL 11,939 or the selective 5-HT1A antagonist WAY-100635 but was prevented by pretreatment with the selective dopamine D2/D3 receptor antagonist raclopride (0.1 mg/kg, s.c).
The effect of LSD on PPI is mediated by the 5-HT2A receptor, whereas activation of the 5-HT2A receptor does not appear to contribute to the effect of lisuride on PPI. These findings demonstrate that lisuride and LSD disrupt PPI via distinct receptor mechanisms and provide additional support for the classification of lisuride as a non-hallucinogenic 5-HT2A agonist
Proteins on the catwalk: modelling the structural domains of the CCN family of proteins
The CCN family of proteins (CCN1, CCN2, CCN3, CCN4, CCN5 and CCN6) are multifunctional mosaic proteins that play keys roles in crucial areas of physiology such as angiogenesis, skeletal development tumourigenesis, cell proliferation, adhesion and survival. This expansive repertoire of functions comes through a modular structure of 4 discrete domains that act both independently and in concert. How these interactions with ligands and with neighbouring domains lead to the biological effects is still to be explored but the molecular structure of the domains is likely to play an important role in this. In this review we have highlighted some of the key features of the individual domains of CCN family of proteins based on their biological effects using a homology modelling approach
Induction by transforming growth factor-β1 of epithelial to mesenchymal transition is a rare event in vitro
INTRODUCTION: Transforming growth factor (TGF)-β1 is proposed to inhibit the growth of epithelial cells in early tumorigenesis, and to promote tumor cell motility and invasion in the later stages of carcinogenesis through the induction of an epithelial to mesenchymal transition (EMT). EMT is a multistep process that is characterized by changes in cell morphology and dissociation of cell–cell contacts. Although there is growing interest in TGF-β1-mediated EMT, the phenotype is limited to only a few murine cell lines and mouse models. METHODS: To identify alternative cell systems in which to study TGF-β1-induced EMT, 18 human and mouse established cell lines and cultures of two human primary epithelial cell types were screened for TGF-β1-induced EMT by analysis of cell morphology, and localization of zonula occludens-1, E-cadherin, and F-actin. Sensitivity to TGF-β1 was also determined by [(3)H]thymidine incorporation, flow cytometry, phosphorylation of Smad2, and total levels of Smad2 and Smad3 in these cell lines and in six additional cancer cell lines. RESULTS: TGF-β1 inhibited the growth of most nontransformed cells screened, but many of the cancer cell lines were insensitive to the growth inhibitory effects of TGF-β1. In contrast, TGF-β1 induced Smad2 phosphorylation in the majority of cell lines, including cell lines resistant to TGF-β1-mediated cell cycle arrest. Of the cell lines screened only two underwent TGF-β1-induced EMT. CONCLUSION: The results presented herein show that, although many cancer cell lines have lost sensitivity to the growth inhibitory effect of TGF-β1, most show evidence of TGF-β1 signal transduction, but only a few cell lines undergo TGF-β1-mediated EMT
The reproductive biology and effective pollinators of the endangered beardtongue \u3ci\u3ePenstemon penlandii \u3c/i\u3e(Scrophulariaceae)
Penland\u27s beardtongue, a rare endemic plant of the Colorado Plateau, displays a mixed breeding system. Plants are partially self-compatible but set more fruits when cross-pollinated than when self-pollinated. Fruit production is significantly increased by pollinators. However, in two years of study there was no indication that fruit set was being limited by inadequate pollinator visitation. Pollinator effectiveness was judged by correlating bee behavior at the flowers with analysis of the pollen carried on bee bodies. The most important pollinators were native megachilid bees, particularly in the genus Osmia. The bees that pollinate Penland\u27s beardtongue are essential to its reproduction and must be preserved along with this rare plant
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