ABSTRACT
Abstract Purpose: To evaluate whether combining hypothermia and remote ischemic preconditioning (RIPC) results in protection from ischemia-reperfusion (IR). Methods: Thirty-two Wistar rats underwent right nephrectomy and were randomly assigned to four experimental protocols on the left kidney: warm ischemia (group 1), cold ischemia (group 2), RIPC followed by warm ischemia (group 3), and RIPC followed by cold ischemia (group 4). After 240 minutes of reperfusion, histological changes in the left kidney, as well as lipid peroxidation and antioxidant enzyme activity, were analyzed. The right kidney was used as the control. Serum creatinine was collected before and after the procedures. Results: RIPC combined with hypothermia during IR experiments revealed no differences on interventional groups regarding histological changes (p=0.722). Oxidative stress showed no significant variations among the groups. Lower serum creatinine at the end of the procedure was seen in animals exposed to hypothermia (p<0.001). Conclusions: Combination of RIPC and local hypothermia provides no renal protection in IR injury. Hypothermia preserves renal function during ischemic events. Furthermore, RIPC followed by warm IR did not show benefits compared to warm IR alone or controls in our experimental protocol.
Subject(s)
Animals , Male , Rats , Reperfusion Injury/prevention & control , Oxidative Stress/physiology , Ischemic Preconditioning/methods , Hypothermia, Induced/methods , Kidney/blood supply , Superoxide Dismutase/metabolism , Rats, Wistar , Combined Modality Therapy , Disease Models, Animal , Cold Ischemia , Warm Ischemia , Kidney/pathologyABSTRACT
Abstract Purpose: To evaluate whether their combination was more effective than either alone in decreasing renal damage due to ischemia/reperfusion (I/R) injury in rats. Methods: Thirty-two Wistar rats were assigned to four groups. Following right nephrectomy, their left kidneys were subjected to warm ischemia (IR), cold ischemia (TH+IR), intraperitoneal injection of 10 mg/kg melatonin (MEL+IR), or injection of 10 mg/kg melatonin followed by cold ischemia (MEL+TH+IR). Eight randomly assigned right kidneys constituted the control group. After 240 min of reperfusion, left nephrectomy was performed for histopathological evaluation, lipid peroxidation, and measurement of antioxidant enzyme activity. Serum was collected to measure urea and creatinine concentrations. Results: Histopathological damage induced by ischemia and reperfusion was more attenuated in the MEL+TH+IR group than in the MEL+IR and TH+IR groups (p<0.037). Superoxide dismutase activity was significantly higher (p<0.029) and creatinine (p<0.001) and urea (p<0.001) concentrations were significantly lower in the MEL+TH+IR group than in the MEL+IR and TH+IR groups. Conclusion: The combination of melatonin (MEL) and topical hypothermia (TH) better protects against renal I/R injury than does MEL or TH alone.
Subject(s)
Animals , Male , Rats , Reperfusion Injury/prevention & control , Hypothermia, Induced/methods , Kidney/blood supply , Melatonin/therapeutic use , Superoxide Dismutase/metabolism , Reperfusion Injury/pathology , Rats, Wistar , Combined Modality Therapy , Oxidative Stress , Disease Models, Animal , Malondialdehyde/metabolismABSTRACT
Abstract Purpose: Topical hypothermia and local ischemic preconditioning have been shown to reduce renal ischemia-reperfusion (I/R) injury individually. We examined whether combination of both strategies lessens renal I/R injury. Methods: Post right nephrectomy, 40 male Wistar rats were randomly assigned to five experimental protocols performed in the left kidney: topical hypothermia without ischemia (TH), warm ischemia (IR), ischemic preconditioning followed by warm ischemia (IPC+IR), cold ischemia (TH+IR), and ischemic preconditioning followed by cold ischemia (IPC+TH+IR). Eight randomly assigned right kidneys constituted the control group. After 240 min of reperfusion, the left kidney was retrieved to evaluate histological changes, lipid peroxidation and antioxidant enzymes activity. Serum was collected to evaluate urea and creatinine. Results: IPC+TH+IR group revealed no difference to any other group subjected to ischemia in relation to histological changes, lipid peroxidation and antioxidant enzymes activity. Creatinine was lower in IPC+TH+IR group compared with IPC+IR, but showed no difference compared to TH+IR group. Conclusions: Combination of local ischemic preconditioning (IPC) and topical hypothermia conferred no protection in renal I/R injury. Moreover, local IPC solely followed by warm ischemia impaired renal function more than warm ischemia alone.
Subject(s)
Animals , Male , Rats , Reperfusion Injury/prevention & control , Ischemic Preconditioning/methods , Hypothermia, Induced/methods , Kidney/pathology , Lipid Peroxidation , Reperfusion Injury/pathology , Reperfusion Injury/blood , Random Allocation , Rats, Wistar , Disease Models, Animal , Kidney/blood supply , Kidney/chemistry , NephrectomyABSTRACT
PURPOSE: To evaluate whether topical renal hypothermia (TRH) at different levels of temperature has protective effects on lung tissue after renal I/R, through an analysis of organ histology and inflammatory markers in lung tissue. METHODS: Twenty-eight male Wistar rats were randomly allocated across four groups and subjected to renal ischemia at different levels of topical renal temperature: normothermia (no cooling, 37°C), mild hypothermia (26°C), moderate hypothermia (15°C), and deep hypothermia (4°C). To induce I/R, the vessels supplying the left kidney of each animal were clamped for 40 minutes, followed by reperfusion. After four hours, another procedure was performed to harvest the tissues of interest. TNF-α, IL-1β and myeloperoxidase activity were measured in lung tissue. Histological analysis was performed in hematoxylin and eosin-stained lung specimens. RESULTS: Induction of renal I/R under deep topical hypothermia resulted in a significant decrease in lung concentrations of TNF-α compared with normothermic I/R (p<0.05). A trend toward significant correlation was found between lung IL-1β concentration and intensity of hypothermia (Spearman r=−0.37; p=0.055). No difference was found in myeloperoxidase activity or histologic injury between groups. CONCLUSION: Topical renal hypothermia reduces activation of the inflammatory cascade in the lung parenchyma. However, tissue-protective effects were not observed. .
Subject(s)
Animals , Male , Hypothermia, Induced/methods , Interleukin-1beta/metabolism , Kidney/blood supply , Lung/blood supply , Peroxidase/metabolism , Reperfusion Injury/metabolism , Tumor Necrosis Factor-alpha/metabolism , Cold Temperature , Enzyme-Linked Immunosorbent Assay , Kidney/pathology , Lung/pathology , Random Allocation , Rats, Wistar , Reproducibility of Results , Reperfusion Injury/etiology , Time FactorsABSTRACT
PURPOSE:To design an animal model of ischemia-reperfusion (I/R) in kidneys and evaluate the role that predetermined ranges of local hypothermia plays on markers of stress-oxydative as well as on histologic sections. METHODS: Twenty eight male rats Wistar, under general anesthesia, undergone right nephrectomy (G0, control group) followed by left kidney ischemia during 40 min. Four temperatures groups were designed, with seven animals randomized for each group: normothermic (G1, ±37ºC), mild hypothermia (G2, 26ºC), moderate hypothermia (G3, 15ºC) and deep hypothermia (G4, 4ºC). Left kidney temperature was assessed with an intraparenchymal probe. Left nephrectomy was performed after 240 min of reperfusion. After I/R a blood sample was obtained for f2-IP. Half of each kidney was sent to pathological evaluation and half to analyze CAT, SOD, TBARS, NO3, NO2. RESULTS:Histopathology showed that all kidneys under I/R were significantly more injured than the G0 (p<0.001). TBARS had increased levels in all I/R groups compared with the G0 (p<0.001). CAT had a significant difference (p<0.03) between G1 and G4. Finally, no difference was found on SOD, NO3, NO2 nor on f2-IP. CONCLUSION: This model of I/R was efficient to produce oxidative-stress in the kidney, showing that 4ºC offered significant decrease in free radicals production, although tissue protection was not observed.
Subject(s)
Animals , Male , Rats , Hypothermia, Induced , Ischemia/metabolism , Kidney/blood supply , Oxidative Stress/physiology , Reperfusion Injury/metabolism , Biomarkers , Free Radicals/metabolism , Kidney/metabolism , Kidney/pathology , Lipid Peroxidation , Models, Animal , Nephrectomy , Nitric Oxide/metabolism , Random Allocation , Rats, Wistar , Reperfusion Injury/pathology , Time FactorsABSTRACT
Recentemente, o transplante renal passou a ser uma modalidade terapêutica aceita para o tratamento de pacientes renais crônicos terminais infectados pelo HIV. Para tal, há necessidade de estabilidade de parâmetros clínicos e laboratoriais relacionados à infecção pelo HIV e do uso de terapia antiretroviral de elevada eficiência. Neste relato, apresentamos os dois primeiros casos no Brasil de pacientes portadores de infecção pelo HIV transplantados com órgãos de doadores falecidos realizados com sucesso em nossa instituição. As interações entre os imunossupressores e as drogas antiretrovirais, as coinfecções, o perfil de risco cardiovascular e a elevada incidência de rejeição aguda permanecem os maiores problemas a serem equacionados nestes pacientes.
Recently kidney transplantation has become an accepted treatment modality for the treatment of HIV infected patients with end-stage renal diseases. For such treatment it is required stability of clinical and laboratory parameters related to HIV infection and the use of highly active antiretroviral therapy. In this report we present the first two cases in Brazil of patients with HIV infection transplanted with organs from deceased donors performed successfully in our institution. The interactions between immunosuppressive and antiretroviral drugs, the co-infections, cardiovascular risk profile and the high incidence of acute rejection remain the major problems to be dealt with in these patients.
Subject(s)
Adult , Female , Humans , Middle Aged , HIV Seropositivity/complications , Kidney Transplantation , Kidney Failure, Chronic/complications , Kidney Failure, Chronic/surgery , HospitalsABSTRACT
Objectives: We are proposing the adaptation of a method for the assessment of the activity of 5 alpha-reductase type 1 and type 2 isoenzymes in human prostate tissue to be used in studies of the relationship of enzymatic activity and cancer. Material and Methods: We have been developing a method, based on Thomas et al., 2003 which consists of collecting human prostate samples and performing 5 alpha-reductase activity assessment. We are proposing a method based on samples obtained from prostate biopsies, according to a pilot study developed by Oliveira et al. 2006. We have obtained two samples of the same prostate area, and our idea is to send one of these samples for pathological examination and another for 5 alpha-reductase evaluation. Herein we have showed the feasibility of this assay. Through a thin layer chromatography with 14C-testosterone and NADPH (nicotinamide adenine dinucleotide phosphate) cofactor, we have obtained radioactive spots which were detected by autoradiography. The areas associated with testosterone and its metabolite DHT (dihydrotestosterone) were scrapped and counted with a scintillation chamber. Results: We believe that it is possible to demonstrate the activity of 5 alpha-reductase through the adaptation of this biochemistry method. Conclusions: This method is feasible and can be utilized to assess 5 alpha-reductase type 1 and type 2 activity in prostate tissue samples.
Subject(s)
Humans , Male , Adult , Androgens , Prostatectomy , Prostatic NeoplasmsABSTRACT
Estudos prévios sugerem que o tempo de lazer diminui progressivamente durante o curso médico, e que a reduçäo de qualidade de vida pode se refletir na reduçäo do desempenho curricular. Näo há relatos de associaçäo entre a quantidade de lazer e a performance acadêmica. Para avaliar essa associaçäo, foi realizdo estudo de corte transversal controlado, onde se aferiram as horas semanais de lazer e o escore de desempenho acadêmico de 77 estudantes da Faculdade de Medicina da Universidade Federal do Rio Grande do Sul. Observou-se ausência de associaçäo entre lazer e desempenho (risco relativo de 1,1 e P=0,9553). Houve uma discreta correlaçäo positiva entre a valorizaçäo do conceito e as horas semanais de lazer (r=-0,23 +/-0,22). Estes resultados permitem concluir que näo foi observada associaçäo entre horas semanais de lazer e desempenho