oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Uterine Reperfusion Ischemia and Use of Elastic Tourniquet  [PDF]
J. F. Nnang Essone, F. Ovono Abessolo, A. Tsagoulela, G. Edjo Nkhilli, P. Assoumou, J. A. Bang Ntamack, E. Anyunzok, U. Minkobame, J. F. Meye, E. Ngou Milama
Journal of Biosciences and Medicines (JBM) , 2019, DOI: 10.4236/jbm.2019.72009
Abstract: Introduction: In humans, it has not been established that the use of elastic tourniquet (ET) during myomectomies, whose delivery times do not exceed 90 minutes, which is responsible for ischemia reperfusion (I/R) systemic. Objectives: To study the plasma variations of markers of I/R during myomectomies performed with ET, whose exposure time does not exceed 90 minutes. Population and methods: Plasma créatinin phosphokinase kinase (CPK) and gluthatione peroxydase (GPX) levels of patients with ET myoma (M + G +, n = 19), taken before, during and after exposure, were compared to those of women operated on myoma without tourniquet (M + G -, n = 15), carriers of unoperated myomas (M + G0, n = 20) and controls (M0G0, n = 18). The duration of exposure of the ET was determined, and perioperative variations of GPX, Ca2+, K+ and CPK between M + G + and others groups were analyzed (p < 0.005). Results: The average duration of exposure of the ET was 51.56 ± 14.12 [30 - 88] min. In M + G +, prior to insertion, CPK was 71.64, GPX 3.537, Ca2+ 3.000, K+ 3.934, and did not vary from those of M + G - (CPK = 59.354, GPX = 3.205, Ca2+ = 2.525, K+ = 3.788), M + G0 (CPK = 71.640, GPX = 2.759, Ca2+ = 3.004, K+ = 3.934) and M0G0 (CPK = 57.2, GPX = 2.306, Ca2+ = 2.879, K+ = 3.705). Conversely, during the posture (CPK = 95.665, GPX = 3.645, Ca2+ = 3.642, K+ = 4.757) and after the release of the ET (CPK = 135.443, GPX = 3.694, Ca2+ = 3.892, K+ = 5.322), these rates were higher among the M + G + compared to the M + G0 and M0G0, but did not differ from those of the M + G - during (CPK = 91.270, GPX = 3.413, Ca2+ = 3.068, K+ = 4.257) and after release (CPK = 137.776, GPX = 3.632, Ca2+ = 3.148, K+ = 5.075). Conclusion: The plasmatic concentration of ischemia (CPK, K+) and reperfusion (GPX, Ca2+) biomarkers does not differ between M + G + and M + G -, but is elevated relatively to controls (M0G0), but also to M + G0’s group. These results show that, for exposure times not exceeding 90 minutes, the elastic tourniquet is probably not the cause of the increase in plasma I/R markers observed in M + G + women. Moreover, these data suggest that the variations of the markers observed during the different surgical stages within each of the two groups of women M + G + and M + G - compared to those of the controls (M0G0) and unoperated myomas
The Effects of Dexmedetomidine on Ischemia Reperfusion Injury in Patients Undergoing Arthroscopy Under Spinal Anesthesia  [cached]
Senem Koruk,Ayse Mizrak,Recai Kaya,Berna Ugur
Eurasian Journal of Medicine , 2010,
Abstract: Objective: Ischemia and reperfusion injury due to tourniquet application during arthroscopy is a well known problem. This study aimed to compare the effects of dexmedetomidine and ketamine on hemodynamic and respiratory variables and on total anti-oxidant status (TAS), total oxidant status (TOS) and malondialdehyde (MDA) as markers of ischemia-reperfusion injury. Materials and Methods: This study was approved by a local ethics committee. The study was performed on patients undergoing arthroscopic operation under spinal anesthesia. Thirty patients were randomized into two groups: Group D (dexmedetomidine; n=15) and Group K (Ketamine; n=15). Spinal anesthesia at the L2-4 level was achieved using a 25G spinal needle with hyperbaric bupivacaine at a dose of 12-15 mg in all patients. In Group D, patients were sedated with dexmedetomidine at a dose of 0.3-0.5 μg/kg/h, while Group K received ketamine at a dose of 1-1.5 mg/kg/h. Hemodynamic parameters, oxygen saturation, Ramsey sedation scale (RSS), and TAS, TOS, and MDA levels were recorded. Results: Demographic parameters, TAS, TOS and MDA levels were similar between groups. In Group K, the TOS levels after tourniquet removal were significantly lower than at baseline and during the use of the tourniquet. Preoperative hemodynamic and respiratory variables were similar in both groups. Blood pressure values were decreased compared to baseline but these decreases were not statistically significant. Conclusion: In patients undergoing arthroscopy under spinal anesthesia, dexmedetomidine had effects similar to ketamine, led to insignificant alterations in hemodynamic and respiratory variables during surgery and had comparable effects on ischemia-reperfusion injury. Thus, we think that dexmedetomidine can be a safe alternative to ketamine as an intraoperative sedative.
Ketamine anesthesia reduces intestinal ischemia/reperfusion injury in rats  [cached]
Carlos Rodrigo Cámara, Francisco Javier Guzmán, Ernesto Alexis Barrera, Andrés Jesús Cabello, Armando Garcia, Nancy Esthela Fernández, Eloy Caballero, Jesus Ancer
World Journal of Gastroenterology , 2008,
Abstract: AIM: To investigate the effects of ketamine anesthesia on the motility alterations and tissue injury caused by ischemia/reperfusion in rats.METHODS: Thirty male Wistar rats weighing 200-250 g were used. Ischemia was induced by obstructing blood flow in 25% of the total small intestinal length (ileum) with a vascular clamp for 45 min, after which either 60 min or 24 h of reperfusion was allowed. Rats were either anesthetized with pentobarbital sodium (50 mg/kg) or ketamine (100 mg/kg). Control groups received sham surgery. After 60 min of reperfusion, the intestine was examined for morphological alterations, and after 24 h intestinal basic electrical rhythm (BER) frequency was calculated, and intestinal transit determined in all groups.RESULTS: The intestinal mucosa in rats that were anesthetized with ketamine showed moderate alterations such as epithelial lifting, while ulceration and hemorrhage was observed in rats that received pentobarbital sodium after 60 min of reperfusion. Quantitative analysis of structural damage using the Chiu scale showed significantly less injury in rats that received ketamine than in rats that did not (2.35 ± 1.14 vs 4.58 ± 0.50, P < 0.0001). The distance traveled by a marker, expressed as percentage of total intestinal length, in rats that received pentobarbital sodium was 20% ± 2% in comparison with 25.9% ± 1.64% in rats that received ketamine (P = 0.017). BER was not statistically different between groups.CONCLUSION: Our results show that ketamine anesthesia is associated with diminished intestinal injury and abolishes the intestinal transit delay induced by ischemia/reperfusion.
Prevention of renal ischemia/reperfusion injury in rats using acetylcysteine after anesthesia with isoflurane
Mansano, André Marques;Vianna, Pedro Thadeu Galv?o;Fabris, Viciany Erique;Silva, Leopoldo Muniz da;Braz, Leandro Gobbo;Castiglia, Yara Marcondes Machado;
Acta Cirurgica Brasileira , 2012, DOI: 10.1590/S0102-86502012000400010
Abstract: purpose: to evaluate the effect of n-acetylcysteine, as a renoprotective agent, when administered early after anesthesia induction, against ischemia/reperfusion injury in rats anesthetized with isoflurane. methods: eighteen male wistar rats weighing > 300g were anesthetized with isoflurane. the internal jugular vein and the left carotid artery were dissected and cannulated. the animals were randomly divided into gacetyl, receiving intravenous n-acetylcysteine, 300mg/kg, and gisot, isotonic saline. after 30 minutes, right nephrectomy was performed and the left renal artery was clamped during 45 minutes. the animals were sacrificed after 48 hours and blood samples were taken after anesthetic induction and upon sacrificing of the animals to evaluate blood creatinine. the kidneys were sent for histological analysis. results: the variation in serum creatinine was 2.33mg/dl ± 2.21 in gacetyl and 4.38mg/dl ± 2.13 in gisot (p=0.074). two animals presented intense tubular necrosis in gacetyl, compared to 5 in gisot. only gacetyl presented animals free of tubular necrosis (two) and tubular degeneration (one). conclusion: after renal ischemia/reperfusion, the rats which were given n-acetylcysteine presented less variation in serum creatinine and milder kidney injuries than the control group.
Beneficial effect of the oxygen free radical scavenger amifostine (WR-2721) on spinal cord ischemia/reperfusion injury in rabbits
Fany Chronidou, Efstratios Apostolakis, Ioannis Papapostolou, Konstantinos Grintzalis, Christos D Georgiou, Efstratios N Koletsis, Menelaos Karanikolas, Panagiotis Papathanasopoulos, Dimitrios Dougenis
Journal of Cardiothoracic Surgery , 2009, DOI: 10.1186/1749-8090-4-50
Abstract: Eighteen male, New Zealand white rabbits were anesthetized and spinal cord ischemia was induced by temporary occlusion of the descending thoracic aorta by a coronary artery balloon catheter, advanced through the femoral artery. The animals were randomly divided in 3 groups. Group I functioned as control. In group II the descending aorta was occluded for 30 minutes and then reperfused for 75 min. In group III, 500 mg Amifostine was infused into the distal aorta during the second half-time of ischemia period. At the end of reperfusion all animals were sacrificed and spinal cord specimens were examined for superoxide radicals by an ultra sensitive fluorescent assay.Superoxide radical levels ranged, in group I between 1.52 and 1.76 (1.64 ± 0.10), in group II between 1.96 and 2.50 (2.10 ± 0.23), and in group III (amifostine) between 1.21 and 1.60 (1.40 ± 0.19) (p = 0.00), showing a decrease of 43% in the Group of Amifostine. A lipid peroxidation marker measurement ranged, in group I between 0.278 and 0.305 (0.296 ± 0.013), in group II between 0.427 and 0.497 (0.463 ± 0.025), and in group III (amifostine) between 0.343 and 0.357 (0.350 ± 0.007) (p < 0.00), showing a decrease of 38% after Amifostine administration.By direct and indirect methods of measuring the oxidative stress of spinal cord after ischemia/reperfusion, it is suggested that intra-aortic Amifostine infusion during spinal cord ischemia phase, significantly attenuated the spinal cord oxidative injury in rabbits.Paraplegia remains the most devastating complication following descending thoracic or thoraco-abdominal aortic surgery, with incidence rate from 4% to 33% [1]. It is known that spinal cord ischemia from hypoperfusion during temporary aorta cross clamping, as well as the sacrifice of some intercostals branches contributing to the form of Adamkiewicz's artery, are the cause of this complication. The clinical evidence that some patients recover with no neurological dysfunction only to develop delayed-onse
Experimental ischemia and reperfusion in equine small colon
Faleiros, R.R.;Alves, G.E.S.;Santos, R.L.;Marques Junior, A.P.;Macoris, D.G.;
Arquivo Brasileiro de Medicina Veterinária e Zootecnia , 2001, DOI: 10.1590/S0102-09352001000300012
Abstract: the effects of ischemia and reperfusion were studied in the small colon of 12 horses. under general anesthesia, arterial pressure and arterial hemoglobin oxygen saturation values were maintained constant and within the normal physiological range. after celiotomy, the small colon was exposed and three segments were demarcated. total arterial venous ischemia was induced in two segments during 90 (group a) and 180 (group b) minutes. the third segment was the control group. full-thickness biopsy specimens, for histopathology, were obtained at the end of the ischemia periods and at 90 (groups a and b) and 180 minutes (group a) of reperfusion. the mucosa and the submucosa were evaluated by semiquantitative morphological assessment such as epithelial detachment, edema and hemorrhage, and by quantitative morphological assessment such as percentual depth of mucosal loss (ml) and mucosal crypt:interstitium ratio (c:i). after ischemia, lesions such as ml, c:i, epithelial detachment and mucosal edema were more intense in group b when compared to group a. in both groups after reperfusion there were significant increases in ml, c:i, epithelial detachment and submucosal edema. the results showed aggravation of the mucosal lesions in the reperfusion period in equine small colon, and the model was considered adequate for experimental purposes.
Antioxidants and Myocardial Ischemia: Reperfusion Injuries  [PDF]
Jan-Kan Chen,Shu-Er Chow
Chang Gung Medical Journal , 2005,
Abstract: Animal studies have demonstrated that restoration of bloodflow to severely ischemic myocardium is a prerequisite formyocardial salvage. However, it has been shown that therestoration of blood flow to ischemic myocardium may beassociated with deleterious changes of the myocardium, includingarrhythmias, enzyme release, and contractile dysfunction.These changes were considered to be additional injuries to themyocardium manifested at the time of reperfusion. The reperfusionwas accompanied by a burst of oxygen free radical generationand their role as main mediators of the reperfusioninjury have been well accepted. Reactive oxygen species(ROS) and cellular redox status regulate many important cellularactivities. The role of antioxidant as a therapy for reperfusioninjury has thus been tried with mixed and mostly negativeresults. Further studies are needed if the antioxidant therapiesfor ischemia reperfusion injury were to be effective.
Neuroprotection in Acute Ischemia and Ischemia/Reperfusion in Rat Retina  [PDF]
Renato Guizzo,Marcelo Araujo Rodrigues Cairrao,Joaquim Coutinho-Netto,Antonio Renato Meirelles e Silva
International Journal of Pharmacology , 2005,
Abstract: We compared qualitative and quantitatively the neuroprotective effects of ketamine, nimodipine and lamotrigine in rat retinas submitted to acute ischemia and ischemia followed by reperfusion. Ischemia was induced by increasing of intraocular pressure above systolic blood pressure for 60 min. In reperfusion, intraocular pressure was reduced to normal levels for 45 min. Histological evaluation was performed by computer-assisted measurements from histologic sections. Ischemic retinas revealed a decrease in cells densities, cytoplasm vacuolization, pyknotic nuclei, edema and cell disorganization, when compared to contralateral-control eyes. Further, ischemia/reperfusion showed more evident retinal damage when compared to ischemic retinas. Lamotrigine pretreatment (25 mg kg-1) protected neurons mainly in ganglinar cell layer. Nimodipine pretreatment (20 μg kg-1) protected neurons of ganglion cell layer in ischemia and in ischemia/reperfusion the inner nuclear layer. Ketamine pretreatment (20 mg kg-1) protected neurons mainly in outer nuclear layer and inner nuclear layer in ischemia and ischemia/reperfusion. Present results suggest that lamotrigine, nimodipine and ketamine have potential neuroprotective properties in acute ischemia and ischemia/reperfusion models and all of them may have therapeutic implications for retina.
Lipid peroxidation and renal injury in renal ischemia/reperfusion: Effect of Benincasa cerifera
Bhalodia Y,Vaghasiya J,Malaviya S,Jivani N
International Journal of Green Pharmacy , 2009,
Abstract: To investigate the role of the methanolic fruit extract of Benincasa cerifera on lipid peroxidation (LPO) and renal pathology in ischemia/reperfusion (I/R).In experimental methodology, both renal pedicles were occluded for 60 min followed by 24 h of reperfusion. B. cerifera (500 mg/kg/day) was administered orally for 5 days prior to induction of renal ischemia and was continued for 1 day after ischemia. At the end of the reperfusion period, rats were sacrificed. Sham-operated rats followed same procedure except renal arteries occlusion. LPO and histopathological analysis were done in renal tissue. Serum creatinine and urea levels were measured for the evaluation of renal function. In ischemia/reperfusion (I/R) rats, malondialdehyde (MDA) levels were increased significantly when compared with sham-control rats. Histological changes showed tubular cell swelling, interstitial oedema, tubular dilation and moderate-to-severe necrosis in epithelium of I/R rat as compared to sham control. The methanolic fruit extract of B. cerifera could attenuate the heightened MDA levels. I/R-induced renal injury was markedly diminished by administration of B. cerifera These results indicate that the methanolic fruit extract of B. cerifera attenuate renal damage after I/R injury of the kidney by potent antioxidant or free radical scavenging activity.
Comparative Effects of Verapamil, Nicardipine, and Nitroglycerin on Myocardial Ischemia/Reperfusion Injury  [PDF]
Hitoshi Yui,Uno Imaizumi,Hisashi Beppu,Mitsuhiro Ito,Munetaka Furuya,Hirofumi Arisaka,Kazu-Ichi Yoshida
Anesthesiology Research and Practice , 2011, DOI: 10.1155/2011/521084
Abstract: The aim of this experiment was to establish whether verapamil, nicardipine, and nitroglycerin have (1) infarct size-limiting effects and (2) antiarrhythmic effects in in vivo rabbit hearts during ischemia/reperfusion. Rabbits received regional ischemia by 30?min of left anterior descending coronary artery occlusion followed by 3 hours of reperfusion under ketamine and xylazine anesthesia. The animals were randomly assigned to the following 4 treatment groups: a control group, a verapamil group, a nicardipine group, and a nitroglycerin group. A continuous infusion of verapamil, nicardipine, or nitroglycerin was initiated 5?min prior to ischemia. Infarct size/area at risk decreased in verapamil, and nitroglycerin. The incidence of ischemia-induced arrhythmia decreased in nicardipine, verapamil and nitroglycerin. The incidence of reperfusion-induced arrhythmias decreased in verapamil and nitroglycerin. From the present experimental results, verapamil and nitroglycerin rather than nicardipine did afford significant protection to the heart subjected to ischemia and reperfusion in a rabbit model. 1. Introduction Myocardial ischemia/reperfusion injury and its prevention have become the focus of considerable attention. It was reported that intracellular calcium overload is a recognized common pathway that can explain ischemia/reperfusion injury [1]. Several studies have shown that -type calcium antagonists have beneficial effects on the ischemic myocardium by inhibiting transmembrane calcium influx in cardiac and vascular smooth muscle [2, 3]. On the other hand, previous experimental studies have investigated effects of nitric oxide (NO) donors to reduce myocardial ischemia/reperfusion injury [4, 5]. This cardioprotection is due to the mechanism that nitroglycerin is converted in vascular smooth muscle cells to NO and relaxes vascular muscle of the large veins and coronary arteries. As a result, nitroglycerin can reduce preload and also provide an increased blood flow to the heart. It is clear that calcium antagonists and NO donors have cardioprotective effects. However, there is no study examining the intensity of myocardial protection of these drugs as indexes of infarct size and arrhythmias. The aim of this experiment was to establish whether verapamil, nicardipine, and nitroglycerin have infarct size-limiting effects and antiarrhythmic effects in in vivo rabbit hearts during ischemia/reperfusion. 2. Materials and Methods The present study was performed in accordance with the Guidelines of Animal Care and Use Committee of Kanagawa Dental College. 2.1.
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.