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Long-term Function (long-term + function)
Selected AbstractsThe Long-Term Effects of Reconciliation in Japanese Macaques Macaca fuscataETHOLOGY, Issue 11 2001Nicola F. Koyama With one exception, all previous studies of reconciliation in non-human primates (friendly reunion between former opponents) have focused on demonstrating the immediate, short-term effects despite the widely held view that reconciliation has a long-term function of repairing social relationships following aggression. To investigate this long-term function I compared mean interaction rates between opponents during the 10 d following reconciled and non-reconciled conflicts to baseline levels of interaction. Aggression rates during the 10 d after non-reconciled conflicts were significantly higher than the baseline rate, whereas after reconciled conflicts aggression was minimal. Similarly, grooming, proximity and approach rates during the 10 d after non-reconciled conflicts were significantly lower than the baseline rate whereas grooming, proximity and approach rates in the 10 d after reconciled conflicts were restored to baseline levels. These results indicate that there are consequences to not reconciling with a former opponent and highlight the fact that these may be costly in terms of increased risk of long-term aggression and reduced affiliation. The data support predictions from the Relationship-Repair Hypothesis suggesting that reconciliation functions as a mechanism for the repair of social relationships damaged by aggression. [source] Corrosion aspects of metallic implants , An overviewMATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 11 2008A. Balamurugan Abstract The ability to replace or augment diseased body parts totally or partially has improved both the quality and life span of human population. The decline in surgical risks during recent decades has encouraged the development of more complex procedures for prosthetic implantation. Additionally, a variety of extracorporeal devices, such as the heart, lung and blood dialysis machines are used routinely, but these prosthetic elements have several limitations. Hence, research projects are currently underway to overcome the limitations of synthetic materials by developing formulations with varying properties, such as asymptomatic, long-term function in the human physiological environment, etc., to meet the needs of biomedical surgeons. This review focuses on the several biomaterials corrosion and its measures to prevent corrosion. [source] Engineering physiologically controlled pacemaker cells with lentiviral HCN4 gene transferTHE JOURNAL OF GENE MEDICINE, Issue 5 2008Gerard J. J. Boink Abstract Background Research on biological pacemakers for the heart has so far mainly focused on short-term gene and cell therapies. To develop a clinically relevant biological pacemaker, long-term function and incorporation of autonomic modulation are crucial. Lentiviral vectors can mediate long-term gene expression, while isoform 4 of the Hyperpolarization-activated Cyclic Nucleotide-gated channel (encoded by HCN4) contributes to pacemaker function and responds maximally to cAMP, the second messenger in autonomic modulation. Material and Methods Action potential (AP) properties and pacemaker current (If) were studied in single neonatal rat ventricular myocytes that overexpressed HCN4 after lentiviral gene transduction. Autonomic responsiveness and cycle length stability were studied using extracellular electrograms of confluent cultured monolayers. Results Perforated patch-clamp experiments demonstrated that HCN4-transduced single cardiac myocytes exhibited a 10-fold higher If than non-transduced single myocytes, along with slow diastolic depolarization, comparable to pacemaker cells of the sinoatrial node, the dominant native pacemaker. HCN4-transduced monolayers exhibited a 47% increase in beating rate, compared to controls. Upon addition of DBcAMP, HCN4-transduced monolayers had beating rates which were 54% faster than baseline and significantly more regular than controls. Conclusions Lentiviral vectors efficiently transduce cardiac myocytes and mediate functional gene expression. Because HCN4-transduced myocytes demonstrate an increase in spontaneous beating rate and responsiveness to autonomic modulation, this approach may be useful to create a biological pacemaker. Copyright © 2008 John Wiley & Sons, Ltd. [source] Blockade of KATP Channels Reduces Endothelial Hyperpolarization and Leukocyte Recruitment upon Reperfusion After HypoxiaAMERICAN JOURNAL OF TRANSPLANTATION, Issue 4 2009M. Figura Ischemia/reperfusion injury in renal transplantation leads to slow or initial nonfunction, and predisposes to acute and chronic rejection. In fact, severe ischemia reperfusion injury can significantly reduce graft survival, even with modern immunosuppressive agents. One of the mechanisms by which ischemia/reperfusion causes injury is activation of endothelial cells resulting in inflammation. Although several therapies can be used to prevent leukocyte recruitment to ischemic vessels (e.g. antiadhesion molecule antibodies), there have been no clinical treatments reported that can prevent initial immediate neutrophil recruitment upon reperfusion. Using intravital microscopy, we describe abrogation of immediate neutrophil recruitment to ischemic microvessels by the KATP antagonist glibenclamide (GlyburideÔ). Further, we show that glibenclamide can reduce leukocyte recruitment in vitro under physiologic flow conditions. ATP-regulated potassium channels (KATP) are important in the control of cell membrane polarization. Here we describe profound hyperpolarization of endothelial cells during hypoxia, and the reduction of this hyperpolarization using glibenclamide. These findings suggest that control of endothelial membrane potential during ischemia may be an important therapeutic tool in avoiding ischemia/reperfusion injury, and therefore, enhancing transplant long-term function. [source] A novel diketopiperazine improves functional recovery given after the onset of 6-OHDA-induced motor deficit in ratsBRITISH JOURNAL OF PHARMACOLOGY, Issue 4 2009RVM Krishnamurthi Background and purpose:, Cyclo-L-glycyl-L-2-allylproline (NNZ-2591), a modified diketopiperazine, is neuroprotective and improves long-term function after hypoxic-ischaemic brain injury in rats. The present studies were designed to examine both the neuroprotective and neurotrophic actions of NNZ-2591 on neurochemical and behavioural changes in a rat model of Parkinson's disease. Experimental approach:, To examine its protective effect, either NNZ-2591 (20 ng·day,1) or saline was given intracerebroventricularly for 3 days starting 2 h after 6-hydroxydopamine (6-OHDA) induced unilateral striatal lesion. In a subsequent experiment either NNZ-2591 (0.2, 1 and 5 mg·day,1, s.c.) or saline was administered daily for 14 days starting 2 weeks after the lesion. Behavioural and neurochemical outcomes were examined using the adjusting step test and immunohistochemical staining. Key results:, Cyclo-L-glycyl-L-2-allylproline given 2 h after the lesion reduced the degree of motor deficit compared with the saline-treated group. Delayed treatment with NNZ-2591, initiated after the onset of motor deficit, significantly improved motor function from week 7 onwards compared with the saline-treated group. Neither treatment regime altered nigrostriatal dopamine depletion. NNZ-2591 significantly enhanced the expression of doublecortin-positive neuroblasts in the sub-ventricular zone. Conclusions and implications:, These studies reveal that early treatment with NNZ-2591 protects against the motor deficit induced by 6-OHDA and that treatment initiated after the establishment of motor impairment significantly improves long-term motor function. These effects of NNZ-2591 on functional recovery were independent of dopamine depletion and also appeared not to be symptomatic as the improved motor function was long-lasting. NNZ-2591 has potential as a therapeutic agent for neurodegenerative disorders. Mandarin translation of abstract [source] Use of lidocaine metabolism to test liver function during the long-term follow-up of liver transplant recipientsCLINICAL TRANSPLANTATION, Issue 3 2004Filoména Conti Abstract:, Background/Aims:, The aim of this study was to assess the usefulness of the monoethylglycinexylidide (MEGX) test to monitoring the long-term function of liver allografts. Methods:, MEGX production was measured prospectively in 60 consecutive liver transplant recipients undergoing their annual review. Results:, Median MEGX values in liver recipients (54 ng/mL; range 10,146) were lower than those found in healthy controls (78 ng/mL; range 44,118). MEGX values correlated negatively with alanine aminotransferase (ALT) activity (p = 0.004) and with the overall histological score (p = 0.01), and positively with sulfobromophthalein (BSP) and indocyanine green (ICG) clearances (p = 0.0002 and p = 0.002, respectively). A stepwise decline was observed with worsening liver fibrosis, from 71 ± 5 ,g/L in patients with no fibrosis to 27 ± 9 ,g/L in patients with bridging fibrosis (p = 0.002). BSP and ICG clearances correlated more closely than the MEGX test with the overall histological score (p = 0.001 and p = 0.001, respectively) and portal fibrosis (p = 0.002 and p = 0.001). Conclusions:, The measurement of MEGX formation is a simple and non-invasive method to monitor liver graft function. It may constitute a valuable tool for assessing the degree of fibrosis. [source] Cold ischaemia time added to kidneys can be minimized by completing the final cross-match before organs are taken from the operating roomCLINICAL TRANSPLANTATION, Issue 2003Christopher F Bryan Abstract:,Purpose: Minimizing the amount of cold ischaemia time (CIT) added to cadaveric kidneys before their transplantation is an important goal since longer CIT is associated with worse long-term graft outcome. Our organ procurement organization (OPO) and HLA laboratories have taken the approach of performing the histocompatibility testing, including the final cross-match, as early in the donor process as possible. Methods: The data in this study were collected from all consecutive final cross-matches done for cadaveric kidney (n = 113) and simultaneous pancreas + kidney (SPK) (n = 25) transplants done with organs recovered from donors in the Midwest Transplant Network OPO from 1 January 2001 to 9 May 2002. We evaluated the time the final cross-match was completed from when the kidneys from that donor were taken from the operating room (OR) and compared that time with CIT. Results: For kidney transplants, 72% of the final cross-matches were complete before the kidneys were taken from the OR. The CIT of that group (10.4 ± 3.8 h) was significantly lower than that of the group of kidney transplant patients whose final cross-match was done after the kidneys were taken from the OR (15.5 ± 5.8 h) (P < 0.001). Similarly, for SPK transplants, 88% of the final cross-matches were completed before the organs left the OR and the CIT of that group (10.2 ± 3.4 h) was less than in the group whose final cross-match was done after the organs left the OR (14.3 ± 4.8 h) (P > 0.1). Conclusions: These data show that the practice of completing the final cross-match as early in the donor process as possible helps to minimize the amount of cold ischaemia time added to the kidneys and pancreata before transplantation. That should reduce the detrimental influence that longer CIT has on short- and long-term function in kidney as well as SPK transplantation. [source] | |||||||||||||