To assess the age-related changes in kinetic properties of the cardiac Na+ channel, whole-cell voltage-clamp (v-c) experiments were conducted using 3-, 10- and 17-day-old embryonic chick ventricular heart cells. In line with the first-order kinetic model, kinetic parameters for the activation and inactivation of the channel were determined from the v-c results. Simulation studies using kinetic parameters so determined have reproduced the current-voltage relations and the steady-state inactivation characteristics observed in cells in the three age groups. The rate of depolarization of the simulated action potentials was also comparable to that experimentally recorded. In conclusion, the steady-state Na+ conductance can play a significant role in the automatic depolarizations observed in young embryonic ventricular cells.
Baek, Seon Ha
Oh, Kook-Hwan
Kim, Sejoong
Kim, Dong Ki
Joo, Kwon-Wook
Oh, Yun Kyu
Han, Byoung Geun
Chang, Jae Hyun
Chung, Wookyung
Kim, Yon Su
Na, Ki Young
BACKGROUND: The clinical benefits of bioimpedance spectroscopy (BIS)-guided fluid management in patients on hemodialysis have been widely demonstrated. However, no previous reports have evaluated the effect of regular and serial BIS-guided fluid management on the residual renal function (RRF) in patients on peritoneal dialysis (PD). Therefore, we will evaluate the clinical efficacy of BIS-guided fluid management for preserving RRF and protecting cardiovascular events in patients on PD.; METHODS/DESIGN: This is a multicenter, prospective, randomized controlled trial. A total of 138 participants on PD will be enrolled and randomly assigned to receive either BIS-guided fluid management or fluid management based only on the clinical information for 1 year. The primary outcome is the change in the glomerular filtration rate (GFR) between months 0 and 12 after starting treatment. The secondary outcomes will include GFR at month 12, time to the anuric state (urine volume <100 ml/day), and fatal and nonfatal cardiovascular events during treatment.; DISCUSSION: This is the first clinical trial to investigate the effect of BIS-guided fluid management on RRF and for protecting against cardiovascular events in patients on PD.; TRIAL REGISTRATION: Clinical Trials.gov number NCT01887262, June 24, 2013.=20
Cristiane Matté
Siomara C Monteiro
Thiago Calcagnotto
Caren S Bavaresco
Carlos Alexandre Netto
Angela T.S Wyse
In the present Study we determined the effect of chronic administration of homocysteine on Na+,K+-ATPase activity in synaptic membranes from parietal, prefrontal and cingulate cortex of young rats. We also studied the in vitro effect of homocysteine on this enzyme activity and on some oxidative stress parameters, namely thiobarbituric acid-reactive substances (TBA-RS) and total radical-trapping antioxidant potential (TRAP) in the same cerebral structures. For the in vivo studies, we induced elevated levels of homocysteine in blood (500 muM), comparable to those of human homocystinuria, and in brain (60 nmol/g wet tissue) of young rats by injecting subcutaneously homocysteine (0.3-0.6 mumol/g of body weight) twice a day at 8 It intervals from the 6th to the 28th postpartum day. Controls received saline in the same volumes. Rats were killed 12 It after the last injection. Chronic administration of homocysteine significantly decreased (50%) Na+,K+-ATPase activity in parietal, increased (36%) in prefrontal and did not alter in cingulate cortex of young rats. In vitro homocysteine decreased Na+,K+-ATPase activity and TRAP and increased TBA-RS in all cerebral structures studied. It is proposed that the alteration of Na+.K+-ATPase and induction of oxidative stress by homocysteine in cerebral cortex may be one of the mechanisms related to the neuronal dysfunction observed in human homocystinuria. Copyright 2004 ISDN. Published by Elsevier Ltd. All rights reserved.
This paper discusses several aspects of a /Xam Bushman story in which a man brings home a lion cub and insists that it is a dog. The paper seeks to demonstrate that the text is capable of eliciting a range of important critical questions. It argues that the call to exegesis is inherent in most forms of literature, including those that are often treated as folklore or mythology. The paper suggests that there are several aspects of the story that accord with current critical concerns. It concentrates on just two of these: the tension between character and identity in the text and the different modes of knowledge that are present in it. The paper does not attempt to provide an exhaustive or authoritative analysis of the story. Instead it contends that the interpretative possibilities in /Xam literature are more extensive than some of the ways in which it is read would suggest.
Francieli M. Stefanello
Renata Franzon
Clovis M. D. Wannmacher
Moacir Wajner and Angela T. S. Wyse
Homocystinuria is an inborn error of sulphur amino acid metabolism, resulting in accumulation of tissue homocysteine. This disease is characterized predominantly by vascular and nervous system dysfunction. In the present study we investigated the in vitro effects of homocysteine, the main metabolite accumulated in homocystinuria, on platelet Na+,K+-ATPase and serum butyrylcholinesterase (BuChE) activities of young rats. Platelet and serum of 29-day-old Wistar rats were incubated in the absence (control) or presence of homocysteine (0.01–0.5 mM). Results showed that Na+,K+-ATPase and BuChE activities were significantly inhibited by homocysteine. It is proposed that inhibition of Na+,K+-ATPase and BuChE activities might be one useful peripheral marker for the neurotoxic effects of homocysteine.
Estela Natacha Brandt Busanello
Carolina Maso Viegas
Anelise Miotti Tonin
Mateus Grings
Alana Pimentel Moura
Anderson Büker de Oliveira
Paula Eichler
Moacir Wajner
This paper discusses several aspects of a /Xam Bushman story in which a man brings home a lion cub and insists that it is a dog. The paper seeks to demonstrate that the text is capable of eliciting a range of important critical questions. It argues that the call to exegesis is inherent in most forms of literature, including those that are often treated as folklore or mythology. The paper suggests that there are several aspects of the story that accord with current critical concerns. It concentrates on just two of these: the tension between character and identity in the text and the different modes of knowledge that are present in it. The paper does not attempt to provide an exhaustive or authoritative analysis of the story. Instead it contends that the interpretative possibilities in /Xam literature are more extensive than some of the ways in which it is read would suggest.