Necrotizing amebic colitis in an elder patient: an unexpected autopsy finding.

Necrotizing amebic colitis is an uncommon amebiasis complication associated with high mortality. We present a case of necrotizing amebic colitis in an old patient whose diagnosis was revealed at postmortem examination. An 81-year-old man died at home without medical attention. The postmortem examination revealed ulcers involving the entire colon and intestinal perforation. The ulcers were large, geographic, and necrotizing, extending from the cecum to the rectum. The histological examination disclosed the infectious etiology by showing amebic trophozoites at the base of the ulcers. No extra-intestinal lesions were found. No information about previous episodes of dysentery or travel could be obtained. The potential role of aging or drug-causing immunosuppression and the evolution of chronic and latent intestinal infection to a severe and invasive form of amebiasis is discussed. This case reinforces the value of postmortem examination for diagnosing diseases not clinically identified.

Necrotizing amebic colitis in an elder patient: an unexpected autopsy finding

ABSTRACT Necrotizing amebic colitis is an uncommon amebiasis complication associated with high mortality. We present a case of necrotizing amebic colitis in an old patient whose diagnosis was revealed at postmortem examination. An 81-year-old man died at home without medical attention. The postmortem examination revealed ulcers involving the entire colon and intestinal perforation. The ulcers were large, geographic, and necrotizing, extending from the cecum to the rectum. The histological examination disclosed the infectious etiology by showing amebic trophozoites at the base of the ulcers. No extra-intestinal lesions were found. No information about previous episodes of dysentery or travel could be obtained. The potential role of aging or drug-causing immunosuppression and the evolution of chronic and latent intestinal infection to a severe and invasive form of amebiasis is discussed. This case reinforces the value of postmortem examination for diagnosing diseases not clinically identified.

ANCA-associated vasculitis following Oxford-AstraZeneca COVID-19 vaccine in Brazil: Is there a causal relationship? A case report.

This article presents a case of rapidly progressive glomerulonephritis following the Oxford-AstraZeneca COVID-19 vaccine in a female patient 58 years old. After 5 days, she presented fatigue, paleness, arthralgia on hands, knees, ankles, foamy urine, and elevated blood pressure. Exams showed serum creatinine of 2.2 mg/dL (baseline creatinine of 1.0 mg/dL). Urinalysis revealed hematuria, and her 24-h urinary protein excretion was 4.4 g. Additional exams showed hypercholesterolemia, severe anemia, and normal serum albumin. Testing of antineutrophil cytoplasmic antibodies anti-myeloperoxidase was positive at a titer of 1/80. Serum and urine protein electrophoresis and other exams showed no alterations. She was started on steroid pulse therapy after worsening kidney function, reaching serum creatinine of 3.3 mg/dL. A kidney biopsy revealed crescentic glomerulonephritis with glomerular sclerosis, fibrous crescents, interstitial fibrosis, and tubular atrophy. Induction therapy was given with intravenous cyclophosphamide 0.5 g/m2 for 6-monthly pulses, followed by maintenance therapy with oral azathioprine at 2 mg/kg and prednisone tapering. The patient did not develop any complications during the induction therapy, and is currently on maintenance therapy with a serum creatinine of 1.87 mg/dL.

Candida tropicalis Systemic Infection Redirects Leukocyte Infiltration to the Kidneys Attenuating Encephalomyelitis.

Environmental factors, including infections, are strongly associated with the pathogenesis of multiple sclerosis (MS), which is an autoimmune and demyelinating disease of the central nervous system (CNS). Although classically associated with bacterial and viral agents, fungal species have also been suspected to affect the course of the disease. Candida tropicalis is an opportunistic fungus that affects immunocompromised individuals and is also able to spread to vital organs. As C. tropicalis has been increasingly isolated from systemic infections, we aimed to evaluate the effect of this fungus on experimental autoimmune encephalomyelitis (EAE), a murine model to study MS. For this, EAE was induced in female C57BL/6 mice 3 days after infection with 106 viable C. tropicalis yeasts. The infection decreased EAE prevalence and severity, confirmed by the less inflammatory infiltrate and less demyelization in the lumbar spinal cord. Despite this, C. tropicalis infection associated with EAE results in the death of some animals and increased urea and creatinine serum levels. The kidneys of EAE-infected mice showed higher fungal load associated with increased leukocyte infiltration (CD45+ cells) and higher expression of T-box transcription factor (Tbx21) and forkhead box P3 (Foxp3). Altogether, our results demonstrate that although C. tropicalis infection reduces the prevalence and severity of EAE, partially due to the sequestration of leukocytes by the inflamed renal tissue, this effect is associated with a poor disease outcome.

Acute aortic wall injury caused by aortic cross-clamping: morphological and biomechanical study of the aorta in a swine model of three aortic surgery approaches.

BACKGROUND: Aortic cross-clamping and balloon occlusion of the aorta could lead to damage to the aorta wall. OBJECTIVE: The aim of this study was to investigate changes to the aorta wall related to the method used to interrupt flow (clamping or balloon) in the different techniques available for aortic surgery. METHODS: Experiments were performed on 40 female pigs, weighing 25-30kg, which were randomly allocated to 4 study groups: S (n=10), no intervention (sham group); C (n=10), midline transperitoneal laparotomy for infrarenal abdominal aortic access with 60 min of cross-clamping; L (n=10), laparoscopic infrarenal abdominal aortic surgery with 60 min of cross-clamping; EV (n=10), remote proximal aortic control with transfemoral arterial insertion of aortic occlusion balloon catheter, inflated to provide continued aortic occlusion for 60min. After euthanasia, the aortas were removed and cross-sectioned to obtain histological specimens for light microscopic and morphometric analyses. The remaining longitudinal segments were stretched to rupture and mechanical parameters were determined. RESULTS: We observed a reduction in the yield point of the abdominal aorta, decrease in stiffness and in failure load in the aortic cross-clamping groups (C and L) compared with the EV group. CONCLUSIONS: Aortic cross-clamping during open or laparoscopic surgery can affect the mechanical properties of the aorta leading to decrease in resistance of the aorta wall, without structural changes in aorta wall histology.

Lesão aguda da parede arterial provocada pelo método de interrupção temporária de fluxo em diferentes vias de cirurgia aórtica: estudo morfológico e biomecânico da aorta de porcos / Acute aortic wall injury caused by aortic cross-clamping: morphological and biomechanical study of the aorta in a swine model of three aortic surgery approaches

Resumo Contexto O clampeamento aórtico e a oclusão da aorta com balão poderiam levar a lesões na parede aórtica. Objetivo O objetivo deste estudo foi verificar as alterações da parede aórtica relacionadas ao método de interrupção de fluxo (cample ou balão) em diferentes técnicas disponíveis para cirurgia de aorta. Métodos Os experimentos foram realizados em 40 porcos fêmeas pesando de 25-30 kg, alocados para quatro grupos: S (n = 10), nenhuma intervenção (sham); C (n = 10), laparotomia mediana transperitoneal para acesso à aorta abdominal infrarrenal com tempo de clampeamento de 60 minutos; L (n = 10), cirurgia laparoscópica da aorta abdominal infrarrenal com tempo de clampeamento de 60 minutos; EV (n = 10), controle aórtico proximal com inserção de cateter-balão para oclusão aórtica por acesso femoral, inflado a fim de promover oclusão aórtica contínua por 60 minutos. Após a eutanásia, as aortas foram removidas e seccionadas para obtenção de espécimes histológicos destinados a análises morfométricas e por microscopia de luz. Os fragmentos longitudinais restantes foram estirados até a ruptura, e determinaram-se padrões mecânicos. Resultados Observou-se redução do limite de proporcionalidade da aorta abdominal, diminuição da rigidez e da carga de ruptura nos grupos submetidos a campleamento aórtico (C e L) em comparação ao grupo EV. Conclusões O campleamento aórtico durante cirurgia aberta ou laparoscópica pode afetar as propriedades mecânicas da aorta, ocasionando redução de resistência da parede aórtica sem desencadear alterações na estrutura histológica da parede aórtica.

Abstract Background Aortic cross-clamping and balloon occlusion of the aorta could lead to damage to the aorta wall. Objective The aim of this study was to investigate changes to the aorta wall related to the method used to interrupt flow (clamping or balloon) in the different techniques available for aortic surgery. Methods Experiments were performed on 40 female pigs, weighing 25-30kg, which were randomly allocated to 4 study groups: S (n=10), no intervention (sham group); C (n=10), midline transperitoneal laparotomy for infrarenal abdominal aortic access with 60 min of cross-clamping; L (n=10), laparoscopic infrarenal abdominal aortic surgery with 60 min of cross-clamping; EV (n=10), remote proximal aortic control with transfemoral arterial insertion of aortic occlusion balloon catheter, inflated to provide continued aortic occlusion for 60min. After euthanasia, the aortas were removed and cross-sectioned to obtain histological specimens for light microscopic and morphometric analyses. The remaining longitudinal segments were stretched to rupture and mechanical parameters were determined. Results We observed a reduction in the yield point of the abdominal aorta, decrease in stiffness and in failure load in the aortic cross-clamping groups (C and L) compared with the EV group. Conclusions Aortic cross-clamping during open or laparoscopic surgery can affect the mechanical properties of the aorta leading to decrease in resistance of the aorta wall, without structural changes in aorta wall histology.

Long-term outcomes of the Atypical Hemolytic Uremic Syndrome after kidney transplantation treated with eculizumab as first choice.

INTRODUCTION: The treatment of choice for Atypical Hemolytic Uremic Syndrome (aHUS) is the monoclonal antibody eculizumab. The objective of this study was to assess the efficacy and safety of eculizumab in a cohort of kidney transplant patients suffering from aHUS. METHODS: Description of the prospective cohort of all the patients primarily treated with eculizumab after transplantation and divided into the therapeutic (onset of aHUS after transplantation) and prophylactic use (patients with previous diagnosis of aHUS undergoing kidney transplantation). RESULTS: Seven cases were outlined: five of therapeutic use and two, prophylactic. From the five cases of therapeutic use, there was improvement of the thrombotic microangiopathy in the 48 hours following the start of the drug and no patient experienced relapse during an average follow-up of 21 months in the continuous use of eculizumab (minimum of 6 and maximum of 42 months). One patient died at 6 months, due to Aspergillus infection. From the two cases of prophylactic use, one patient experienced relapsed thrombotic microangiopathy after 4 months and another patient remained asymptomatic after 16 months of follow-up, both on chronic treatment. DISCUSSION: The therapeutic use of eculizumab showed to be effective, with improvement of the microangiopathy parameters and persisting up to the end of the follow-up, without relapses. The additional risk of immunosuppression, leading to opportunistic infections, was well tolerated. The prophylactic use showed to be effective and safe; however, the doses and intervals should be individualized in order to avoid relapsed microangiopathy, especially in patients with factor H mutation.

Emphysematous pyelonephritis in a transplanted kidney

Emphysematous pyelonephritis is a rare infection characterized by necrosis and gas accumulation in the renal parenchyma, adjacent tissues, and/or urinary collecting system. This entity is rarely reported in transplanted kidneys. Computed tomography imaging is necessary for diagnosis and risk classification. The authors described the case of a 58-year-old man who underwent a kidney transplant and presented sepsis from a urinary tract infection. An abdominal tomography showed some characteristics of emphysematous pyelonephritis associated with an abscess. A graft biopsy, performed 45 days after the transplant, failed to show signs of infection, and tubule-interstitial and vascular rejection were ruled out. The patient had a poor outcome, and a nephrectomy was needed, the pathological analysis of which yielded the diagnosis of chronic pyelonephritis with necrotizing papillitis. The patient became hemodynamically unstable and died. The authors highlight the current tomographic criteria for the diagnosis and treatment of emphysematous pyelonephritis and question the validity of accepting the same standards used to guide the treatment of patients without transplants, and call attention to the importance of the clinical status for the indication of nephrectomy in cases of emphysematous pyelonephritis.

Emphysematous pyelonephritis in a transplanted kidney.

Emphysematous pyelonephritis is a rare infection characterized by necrosis and gas accumulation in the renal parenchyma, adjacent tissues, and/or urinary collecting system. This entity is rarely reported in transplanted kidneys. Computed tomography imaging is necessary for diagnosis and risk classification. The authors described the case of a 58-year-old man who underwent a kidney transplant and presented sepsis from a urinary tract infection. An abdominal tomography showed some characteristics of emphysematous pyelonephritis associated with an abscess. A graft biopsy, performed 45 days after the transplant, failed to show signs of infection, and tubule-interstitial and vascular rejection were ruled out. The patient had a poor outcome, and a nephrectomy was needed, the pathological analysis of which yielded the diagnosis of chronic pyelonephritis with necrotizing papillitis. The patient became hemodynamically unstable and died. The authors highlight the current tomographic criteria for the diagnosis and treatment of emphysematous pyelonephritis and question the validity of accepting the same standards used to guide the treatment of patients without transplants, and call attention to the importance of the clinical status for the indication of nephrectomy in cases of emphysematous pyelonephritis.

Membranous nephropathy PLA2R+ associated with Chagas disease.

Chagas disease (CD) - a tropical parasitic disease caused by the protozoan Trypanosoma cruzi - is a major health problem in Latin America. The immune response against the parasite is responsible for chronic CD lesions. Currently, there are no reports of an association between CD and membranous nephropathy (MN). The detection of the phospholipase A2 receptor (PLA2R) as a target antigen in idiopathic MN can improve the differential diagnosis of primary and secondary forms of MN. The authors report the case of a male patient with positive serology for CD who presented sudden death and underwent autopsy. Histological sections of the heart showed multifocal inflammatory infiltrate composed mainly of mononuclear cells, leading to myocardiocytes necrosis and interstitial fibrosis. The kidneys showed a MN with positive expression for PLA2R. As far as we know, this is the first report of a case of primary MN in a patient with CD, with severe chronic cardiomyopathy and heart failure.

Mononuclear inflammatory infiltrate and microcirculation injury in acute rejection: role in renal allograft survival.

This study aimed at investigating associations between monocytes/macrophages (Mo) infiltration and three important criteria associated with acute antibody-mediated rejection: C4d staining, microcirculation injury, and graft survival time. By quantitative analysis, Mo were counted in peritubular capillaries and in the interstitial compartment (peritubular/interstitial Mo), and they were also identified in glomeruli (glomerular Mo). The study included 47 patients who received renal allograft between 1991 and 2009. Capillaritis and glomerulitis were classified by the Banff scoring system, and C4d and Mo were analyzed by immunohistochemistry. In the quantitative analysis, the mean values of 50 Mo per 10 high-power fields (HPF) and 4 Mo per glomerulus were used as cut-off points for the peritubular/interstitial and glomerular compartments, respectively. Positive C4d cases were associated with the groups of biopsies with a mean value ≥50 Mo per 10 HPF (p = 0.01) and ≥4 Mo per glomerulus (p = 0.02). The group with a mean value ≥4 Mo per glomerulus also showed association with the presence of glomerulitis (p = 0.02). Peritubular/interstitial Mo did not associate with glomerulitis. Capillaritis did not show association with peritubular/interstitial or glomerular Mo. As regards graft survival, the infiltration of Mo in glomeruli interfered with allograft survival (p = 0.01). The group with a mean value of ≥4 glomerular Mo presented worse survival at the time of the 1-year follow-up. According to the literature, our data showed that infiltration of mononuclear cells was associated with C4d staining, microcirculation injury, and glomerulitis, in particular, and that glomerular macrophages could influence renal allograft survival.

Treatment of adriamycin-induced nephropathy with erythropoietin and G-CSF.

BACKGROUND: Granulocyte colony-stimulating factor (G-CSF) and Erythropoietin (EPO) are known to stimulate the growth and differentiation of progenitor cells to prevent acute renal injury. This study aimed to assess the use of growth factors to mobilize stem cell in a mouse model of adriamycin-induced chronic kidney disease. METHODS: All animals were injected with adriamycin for kidney injury and allocated into three treatment groups (G-CSF, EPO and G-CSF + EPO), and a control group (adriamycin alone). RESULTS: Number of atrophic sites, glomerulosclerosis rate and interstitial fibrosis severity score were assessed in all groups. In all treatment groups, histologic parameters did not significantly differ, but were lower than in the control group (P<.001). Scal and CD34 expressions among treatment groups showed no statistically significant difference, but were higher than in the control group (P<.0001). CD105 expression was higher in EPO and G+EPO as compared to G-CSF and the control group (P<.0001), with no statistically significant difference between the latter two groups (P = NS). CONCLUSION: G-CSF and EPO had a histologic protective effect, while treatment with EPO + G-CSF had no additive effects in a model of adriamycin-induced chronic kidney disease.

[Clinical and laboratorial characteristics associated with biopsy proved hypertensive nephroangiosclerosis]. / Características clínicas e laboratoriais associadas à nefroangioesclerose hipertensiva confi rmada por biópsia renal.

INTRODUCTION: Hypertensive nephroangiosclerosis is a major cause of chronic kidney disease requiring dialysis. Clinical characteristics that distinguish a patient with hypertension that evolves to nephroangiosclerosis from another that keeps stable renal function are not well established because of the difficulty in ensuring that the carriers of that disease are not actually suffering from glomerulonephritis or other kidney diseases. Thus, our objective was to identify clinical or laboratory features that distinguish the patients who developed chronic renal failure from hypertension, confirmed by renal biopsy, of those who, even with arterial hypertension, did not develop nephroangiosclerosis. METHODS: We conducted a retrospective comparison of clinical and laboratory data of 15 patients with hypertensive nephroangiosclerosis confirmed by renal biopsy and 15 hypertensive patients from the outpatient clinic of the Hypertension Center, whose lack of nephroangiosclerosis was defined as absence of proteinuria. The groups were matched for age and gender. RESULTS: Among the evaluated variables, duration of hypertension, pulse pressure, blood glucose, uric acid, creatinine and frequency of use of diuretics and sympatholytic differed statistically between the two groups. All these variables were higher in nephroangiosclerosis patients. CONCLUSION: This study links biopsy proven hypertensive nephroangiosclerosis with metabolic features, hypertension intensity and duration, corroborating the idea that primary prevention of hypertension, postponing its initiation, a more intensive hemodynamic control (when hypertension is well established) and metabolic control of these patients have the potential to prevent hypertensive nephroangiosclerosis.

Características clínicas e laboratoriais associadas à nefroangioesclerose hipertensiva confi rmada por biópsia renal / Clinical and laboratorial characteristics associated with biopsy proved hypertensive nephroangiosclerosis

INTRODUÇÃO: A nefroangioesclerose hipertensiva é importante causa de doença renal crônica com necessidade de diálise. As características que distinguem um portador de hipertensão arterial que evolui com nefroangioesclerose de outro que mantém função renal estável não são bem estabelecidas, devido à dificuldade em assegurar que os portadores daquela doença não sejam, na verdade, portadores de glomerulopatias ou outras doenças renais confundíveis. Dessa maneira, o objetivo deste trabalho foi identificar características clínicas ou laboratoriais que distingam os pacientes que desenvolveram doença renal crônica a partir da hipertensão, confirmada por biópsia renal, daqueles que, mesmo apresentando hipertensão arterial, não desenvolveram nefroangioesclerose. MÉTODOS: Realizou-se comparação retrospectiva de dados clínicos e laboratoriais de 15 portadores de nefroangioesclerose hipertensiva confirmada por biópsia renal e 15 hipertensos oriundos do ambulatório do Centro de Hipertensão Arterial, cuja ausência de nefroangioesclerose foi definida pela ausência de proteinúria. Os grupos foram pareados quanto à idade e gênero. RESULTADOS: Dentre as variáveis avaliadas, tempo de hipertensão arterial, pressão de pulso, glicemia, ácido úrico, creatinina e frequência de uso de diuréticos e simpatolíticos diferiram estatisticamente entre os dois grupos. Todas essas variáveis apresentaram valores maiores no grupo com nefroangioesclerose hipertensiva. CONCLUSÃO: O presente estudo associa a nefroangioesclerose hipertensiva, confirmada por biópsia, com alterações metabólicas, duração e intensidade da hipertensão e corrobora a ideia de que a prevenção primária da hipertensão arterial, postergando o seu início, o controle pressórico mais estrito, quando a hipertensão já está estabelecida, bem como o controle metabólico têm a potencialidade de prevenir o desenvolvimento de nefroangioesclerose hipertensiva.

INTRODUCTION: Hypertensive nephroangiosclerosis is a major cause of chronic kidney disease requiring dialysis. Clinical characteristics that distinguish a patient with hypertension that evolves to nephroangiosclerosis from another that keeps stable renal function are not well established because of the difficulty in ensuring that the carriers of that disease are not actually suffering from glomerulonephritis or other kidney diseases. Thus, our objective was to identify clinical or laboratory features that distinguish the patients who developed chronic renal failure from hypertension, confirmed by renal biopsy, of those who, even with arterial hypertension, did not develop nephroangiosclerosis. METHODS: We conducted a retrospective comparison of clinical and laboratory data of 15 patients with hypertensive nephroangiosclerosis confirmed by renal biopsy and 15 hypertensive patients from the outpatient clinic of the Hypertension Center, whose lack of nephroangiosclerosis was defined as absence of proteinuria. The groups were matched for age and gender. RESULTS: Among the evaluated variables, duration of hypertension, pulse pressure, blood glucose, uric acid, creatinine and frequency of use of diuretics and sympatholytic differed statistically between the two groups. All these variables were higher in nephroangiosclerosis patients. CONCLUSION: This study links biopsy proven hypertensive nephroangiosclerosis with metabolic features, hypertension intensity and duration, corroborating the idea that primary prevention of hypertension, postponing its initiation, a more intensive hemodynamic control (when hypertension is well established) and metabolic control of these patients have the potential to prevent hypertensive nephroangiosclerosis.

Prevention of experimental diabetes by Uncaria tomentosa extract: Th2 polarization, regulatory T cell preservation or both?

ETHNOPHARMACOLOGICAL RELEVANCE: Uncaria tomentosa (Willd.) DC (Rubiaceae) is a species native to the Amazon rainforest and surrounding tropical areas that is endowed with immunomodulatory properties and widely used around the world. In this study we investigated the immunomodulatory potential of Uncaria tomentosa (UT) aqueous-ethanol extract on the progression of immune-mediated diabetes. MATERIALS AND METHODS: C57BL/6 male mice were injected with MLDS (40 mg/kg) and orally treated with UT at 10-400mg/kg during 21 days. Control groups received MLDS alone or the respective dilution vehicle. Pancreatic mononuclear infiltrate and ß-cell insulin content were analyzed by HE and immunohistochemical staining, respectively, and measured by digital morphometry. Lymphocyte immunophenotyping and cytokine production were determined by flow cytometry analysis. RESULTS: Treating the animals with 50-400mg/kg of UT caused a significant reduction in the glycemic levels, as well as in the incidence of diabetes. The morphometric analysis of insulitis revealed a clear protective effect. Animals treated with UT at 400mg/kg presented a higher number of intact islets and a significant inhibition of destructive insulitis. Furthermore, a significant protection against the loss of insulin-secreting presented ß-cells was achieved, as observed by a careful immunohistochemical evaluation. The phenotypic analysis indicated that the groups treated with higher doses (100-400mg/kg) presented CD4(+) and CD8(+) T-cell values similar to those observed in healthy animals. These same higher doses also increased the number of CD4(+)CD25(+)Foxp3(+) regulatory T-cells. Moreover, the extract modulated the production of Th1 and Th2, with increased levels of IL-4 and IL-5. CONCLUSIONS: The extract was effective to prevent the progression of immune-mediated diabetes by distinct pathways.

Uncaria tomentosa aqueous-ethanol extract triggers an immunomodulation toward a Th2 cytokine profile.

Uncaria tomentosa (Willd.) DC (Rubiaceae) is a large woody vine that is native to the Amazon and Central American rainforests and is used widely in traditional medicine for its immunomodulatory and antiinflammatory activities. The present work used in vivo immunotoxic and in vitro immunomodulatory experiments to investigate the effects of a pentacyclic oxindole alkaloid extract from U. tomentosa bark on lymphocyte phenotype, Th1/Th2 cytokine production, cellular proliferation and cytotoxicity. For the in vivo immunotoxicity testing, BALB/c male mice were treated once a day with 125, 500 or 1250 mg/kg of U. tomentosa extract for 28 days. For the in vitro protocol, lymphocytes were cultured with 10-500 µg/mg of the extract for 48 h. The extract increased the cellularity of splenic white pulp and the thymic medulla and increased the number of T helper lymphocytes and B lymphocytes. Also, a large stimulatory effect on lymphocyte viability was observed. However, mitogen-induced T lymphocyte proliferation was significantly inhibited at higher concentrations of U. tomentosa extract. Furthermore, an immunological polarization toward a Th2 cytokine profile was observed. These results suggest that the U. tomentosa aqueous-ethanol extract was not immunotoxic to mice and was able to modulate distinct patterns of the immune system in a dose-dependent manner.

Dexmedetomidina e S(+)-cetamina em lesão de isquemia e reperfusão no rim de rato / Dexmedetomidine and S(+)-ketamine in ischemia and reperfusion injury in the rat kidney

PURPOSE: To investigate blood creatinine and renal histology in rats anesthetized with S(+)-ketamine (keta) or dexmedetomidine (dex) and submitted to kidney ischemia/reperfusion injury (IRI). METHODS: Under intraperitoneal (ip) S(+)-ketamine, 20 male Wistar rats were divided into two groups (n=10): maintenance with iv S(+)-ketamine or dex (keta and dex groups), and submitted to right (R) nephrectomy and left (L) renal artery clamping for 45 min. Blood creatinine was measured before ischemia (T1) and 48h after reperfusion (T2), when L nephrectomy was performed. Histological analysis was performed in all kidneys. RESULTS: Blood creatinine was significantly higher at T2 in both groups, but dex group results were lower than those of keta group. Histological changes: between groups, R kidneys did not differ; there were significant high scores for vascular dilation: keta L kidneys; for vascular congestion, tubular dilation, and necrosis: L kidneys from both groups; for tubular degeneration: keta R kidneys. CONCLUSION: S(+)-ketamine plus IRI were aggressive to rat kidneys, according to histological changes, and dexmedetomidine may have not totally protected the kidneys from these injuries, despite the better results of blood creatinine.

OBJETIVO: Investigar a creatinina sanguínea e histologia renal em ratos anestesiados com S(+)-cetamina (ceta) ou dexmedetomidina (dex) e submetidos à lesão de isquemia/reperfusão renal (IR). MÉTODOS: Sob S(+)-cetamina intraperitoneal (ip), 20 ratos Wistar machos foram distribuídos em dois grupos (n=10): manutenção com S(+)-cetamina ou dexmedetomidina, iv, (grupos ceta e dex), e submetidos à nefrectomia direita (D) e clampeamento da artéria renal esquerda (E) por 45 min. A creatinina sanguínea foi dosada antes da isquemia (T1) e 48h após a reperfusão (T2), quando foi realizada nefrectomia E. Houve análise histológica de todos os rins. RESULTADOS: A creatinina foi significativamente maior em T2 em ambos os grupos, porém menor com a dexmedetomidina. Alterações histológicas: entre grupos, os rins Ds não diferiram; houve escores altos significativos para dilatação vascular: rins Es do grupo ceta; para congestão vascular, dilatação tubular, necrose: rins Es de ambos os grupos; para degeneração tubular: rins Ds do grupo ceta. CONCLUSÃO: S(+)-cetamina e IR foram agressivas histologicamente para rins de ratos e a dexmedetomidina pode não ter protegido totalmente os rins dessas lesões, apesar dos melhores resultados de creatinina.

Dexmedetomidine and S(+)-ketamine in ischemia and reperfusion injury in the rat kidney / Dexmedetomidina e S(+)-cetamina em lesão de isquemia e reperfusão no rim de rato

PURPOSE: To investigate blood creatinine and renal histology in rats anesthetized with S(+)-ketamine (keta) or dexmedetomidine (dex) and submitted to kidney ischemia/reperfusion injury (IRI). METHODS: Under intraperitoneal (ip) S(+)-ketamine, 20 male Wistar rats were divided into two groups (n=10): maintenance with iv S(+)-ketamine or dex (keta and dex groups), and submitted to right (R) nephrectomy and left (L) renal artery clamping for 45 min. Blood creatinine was measured before ischemia (T1) and 48h after reperfusion (T2), when L nephrectomy was performed. Histological analysis was performed in all kidneys. RESULTS: Blood creatinine was significantly higher at T2 in both groups, but dex group results were lower than those of keta group. Histological changes: between groups, R kidneys did not differ; there were significant high scores for vascular dilation: keta L kidneys; for vascular congestion, tubular dilation, and necrosis: L kidneys from both groups; for tubular degeneration: keta R kidneys. CONCLUSION: S(+)-ketamine plus IRI were aggressive to rat kidneys, according to histological changes, and dexmedetomidine may have not totally protected the kidneys from these injuries, despite the better results of blood creatinine.(AU)

OBJETIVO: Investigar a creatinina sanguínea e histologia renal em ratos anestesiados com S(+)-cetamina (ceta) ou dexmedetomidina (dex) e submetidos à lesão de isquemia/reperfusão renal (IR). MÉTODOS: Sob S(+)-cetamina intraperitoneal (ip), 20 ratos Wistar machos foram distribuídos em dois grupos (n=10): manutenção com S(+)-cetamina ou dexmedetomidina, iv, (grupos ceta e dex), e submetidos à nefrectomia direita (D) e clampeamento da artéria renal esquerda (E) por 45 min. A creatinina sanguínea foi dosada antes da isquemia (T1) e 48h após a reperfusão (T2), quando foi realizada nefrectomia E. Houve análise histológica de todos os rins. RESULTADOS: A creatinina foi significativamente maior em T2 em ambos os grupos, porém menor com a dexmedetomidina. Alterações histológicas: entre grupos, os rins Ds não diferiram; houve escores altos significativos para dilatação vascular: rins Es do grupo ceta; para congestão vascular, dilatação tubular, necrose: rins Es de ambos os grupos; para degeneração tubular: rins Ds do grupo ceta. CONCLUSÃO: S(+)-cetamina e IR foram agressivas histologicamente para rins de ratos e a dexmedetomidina pode não ter protegido totalmente os rins dessas lesões, apesar dos melhores resultados de creatinina.(AU)

Dexmedetomidine and S(+)-ketamine in ischemia and reperfusion injury in the rat kidney.

PURPOSE: To investigate blood creatinine and renal histology in rats anesthetized with S(+)-ketamine (keta) or dexmedetomidine (dex) and submitted to kidney ischemia/reperfusion injury (IRI). METHODS: Under intraperitoneal (ip) S(+)-ketamine, 20 male Wistar rats were divided into two groups (n=10): maintenance with iv S(+)-ketamine or dex (keta and dex groups), and submitted to right (R) nephrectomy and left (L) renal artery clamping for 45 min. Blood creatinine was measured before ischemia (T1) and 48h after reperfusion (T2), when L nephrectomy was performed. Histological analysis was performed in all kidneys. RESULTS: Blood creatinine was significantly higher at T2 in both groups, but dex group results were lower than those of keta group. Histological changes: between groups, R kidneys did not differ; there were significant high scores for vascular dilation: keta L kidneys; for vascular congestion, tubular dilation, and necrosis: L kidneys from both groups; for tubular degeneration: keta R kidneys. CONCLUSION: S(+)-ketamine plus IRI were aggressive to rat kidneys, according to histological changes, and dexmedetomidine may have not totally protected the kidneys from these injuries, despite the better results of blood creatinine.

Glibenclamide effects on renal function and histology after acute hemorrhage in rats under sevoflurane anesthesia.

INTRODUCTION: Hypovolemia from hemorrhage evokes protective compensatory reactions, such as the renin-angiotensin system, which interferes in the clearance function and can lead to ischemia. This study was designed to evaluate the effects of glibenclamide, a K(+)(ATP) channel blocker, on renal function and histology in rats in a state of hemorrhagic shock under sevoflurane anesthesia. MATERIAL AND METHODS: Twenty Wistar rats were randomized into two groups of 10 animals each (G1 and G2), only one of which (G2) received intravenous glibenclamide (1 microg.g(-1)), 60 min before bleeding was begun. Both groups were anesthetized with sevoflurane and kept on spontaneous respiration with oxygen-air, while being bled of 30% of volemia in three stages with 10 min intervals. There was an evaluation of renal function - sodium para-aminohippurate and iothalamate clearances, filtration fraction, renal blood flow, renal vascular resistance - and renal histology. Renal function attributes were evaluated at three moments: M1 and M2, coinciding with the first and third stages of bleeding; and M3, 30 min after M2, when the animals were subjected to bilateral nephrectomy before being sacrificed. RESULTS: Significant differences were found in para-aminohippurate clearance, G1 < G2, and higher renal vascular resistance values were observed in G1. Histological examination showed the greater vulnerability of kidneys exposed to sevoflurane alone (G1) with higher scores of vascular and tubular dilatation. There were vascular congestion and tubular vacuolization only in G1. Necrosis and signs of tubular regeneration did not differ in both groups. CONCLUSION: Treatment with glibenclamide attenuated acutely the renal histological changes after hemorrhage in rats under sevoflurane anesthesia.