Impact of gender in early structural changes of contrast induced nephropathy in rats / Impacto do gênero em alterações estruturais precoces da nefropatia induzida por contraste em ratos

Abstract Introduction: Contrast-induced nephropathy (CIN) is a major iatrogenic cause of acute kidney injury. Experimental studies have shown that intravascular injection causes intense vacuolization of the contrast agent in the proximal renal tubules cells, preceding the increase in serum creatinine, and that the female may be at a higher risk for CIN. Objective: To study the early kidney histomorphometric changes in contrast-induced nephropathy according to the gender. Methods: Twenty previously uninephrectomized Wistar rats were divided into 4 groups (n = 5): control males; control females; contrast exposed males; and contrast exposed females. The animals were sacrificed immediately after contrast administration and kidney tissue samples were collected for histomorphometric analysis. The research project was approved by the Research Ethics Committee of the School of Medicine of Universidade Federal Fluminense. Results: There was a more intense presence of microvacuoles in proximal tubules in the rats exposed to contrast than in the control groups. Such proximal tubular vacuolation was more intensive in the female rats (p = 0.001). Conclusion: Proximal tubular vacuolation is a very early change in CIN and is more intensive in female than in male rats.

Resumo Introdução: A nefropatia induzida por contraste (NIC) é uma das principais causas iatrogênicas de lesão renal aguda. Estudos experimentais têm demonstrado que a injeção intravascular do agente de contraste provoca vacuolização intensa nas células dos túbulos renais proximais, que precede o aumento da creatinina sérica, e que a fêmea podem estar em maior risco de CIN. Objetivo: Estudar as primeiras mudanças histomorfométricas renais na nefropatia induzida por contraste de acordo com o gênero. Métodos: Vinte ratos Wistar anteriormente uninefrectomizados foram divididos em 4 grupos (n = 5): machos de controle; fêmeas de controle; machos expostos ao contraste e fêmeas expostas ao contraste. Os animais foram sacrificados imediatamente após a administração de contraste e amostras de tecido de rim foram coletadas para análise histomorfométrica. O projeto de pesquisa foi aprovado pelo Comitê de Ética em Pesquisa da Faculdade de Medicina da Universidade Federal Fluminense. Resultados: Houve presença mais intensa de microvacuolização em túbulos proximais nos ratos expostos ao contraste do que nos grupos de controle. Tal vacuolização tubular proximal foi mais intensa nos ratos do sexo feminino p = 0,001). Conclusão: Vacuolização do tpubulo proximal é uma mudança precoce na CIN e é mais intensa em ratos fêmeas do que em ratos machos.

Time since death from degenerative changes in the Kidney.

Time since death is made out from gross postmortem changes like cooling of the body, postmortem staining, rigor mortis, decomposition etc. In the present study Histological changes in the Kidney tissue were studied at various postmortem intervals in the human body died due to road traffic accidents. This study is conducted in the Department of Forensic Medicine in collaboration with Department of Pathology, G.S.V.M. Medical College, Kanpur, U.P. A total of 45 cases are taken belonging to both sexes i.e. 36 males and 9 females were studied. These are of different age groups. All road traffic accidents are taken into account. In this study control can not be taken because the histological changes of tissue after death is influenced a great deal by atmospheric temperature and humidity besides other external and internal factors. Therefore these must be taken into account in all studies of postmortem interval whether histological, biochemical or physical.

Gentamicin-induced preconditioning of proximal tubular LLC-PK1 cells stimulates nitric oxide production but not the synthesis of heat shock protein

Nephrotoxicity is the main side effect of antibiotics such as gentamicin. Preconditioning has been reported to protect against injuries as ischemia/reperfusion. The objective of the present study was to determine the effect of preconditioning with gentamicin on LLC-PK1 cells. Preconditioning was induced in LLC-PK1 cells by 24-h exposure to 2.0 mM gentamicin (G/IU). After 4 or 15 days of preconditioning, cells were again exposed to gentamicin (2.0 mM) and compared to untreated control or G/IU cells. Necrosis and apoptosis were assessed by acridine orange and HOESCHT 33346. Nitric oxide (NO) and endothelin-1 were assessed by the Griess method and available kit. Heat shock proteins were analyzed by Western blotting. After 15 days of preconditioning, LLC-PK1 cells exhibited a significant decrease in necrosis (23.5 ± 4.3 to 6.5 ± 0.3%) and apoptosis (23.5 ± 4.3 to 6.5 ± 2.1%) and an increase in cell proliferation compared to G/IU. NO (0.177 ± 0.05 to 0.368 ± 0.073 ìg/mg protein) and endothelin-1 (1.88 ± 0.47 to 2.75 ± 0.53 pg/mL) production significantly increased after 15 days of preconditioning compared toG/IU. No difference in inducible HSP 70, constitutive HSC 70 or HSP 90 synthesis in tubular cells was observed afterpreconditioning with gentamicin. The present data suggest that preconditioning with gentamicin has protective effects on proximal tubular cells, that involved NO synthesis but not reduction of endothelin-1 or production of HSP 70, HSC 70, or HSP 90. We conclude that preconditioning could be a useful tool to prevent the nephrotoxicity induced by gentamicin.

Experimental model for the study of chronic renal ischemia in rats: morphologic, histological and ultra-structural analysis

PURPOSE: To evaluate a model of chronic renal ischemia in rats and to characterize the effects on renal tissue. METHODS: 168 Wistar rats were divided into two equal groups, control (GC) and ischemia (GI). The animals of the GI (n=84) were submitted to partial ligation of the left renal artery, and the animals of GC (n=84) stayed with the renal artery intact. In seven successive and identical periods of time, in weekly intervals, 12 animals of each group were submitted to nephrectomy, with morphometric determinations and histological and ultra-structural analysis. RESULTS: The GI presented progressive reduction in renal weight, volume and cortical thickness observed from the 7th day of the experiment, reaching maximum degree in the 49th day (p < 0.05). The proximal tubular atrophy in the GI was observed in 75/84 analysis (89,2 percent), with highly significant difference among the groups starting from the 7th day (p=0 .0009) and in the other periods of the experiment (p=0 .00001). The most prevalent interstitial alteration was the infiltrate, present in 98,8 percent of the GI, with highly significant difference among the groups in the whole experiment (p=0 .00001). Ultra-structural analysis didn't demonstrate glomerular lesions, evidencing that the glomerule preserves its intact architecture during chronic ischemia. CONCLUSION: The model showed that chronic renal ischemia in rats provokes progressive renal atrophy, with preservation of glomerular structure.

OBJETIVO: Avaliar um modelo de isquemia renal crônica em ratos e caracterizar os efeitos no tecido renal. MÉTODOS: Utilizaram-se 168 ratos Wistar divididos em dois grupos iguais, controle (GC) e isquemia (GI). Os animais do GI (n=84) foram submetidos à ligadura parcial da artéria renal esquerda, e os animais do GC (n=84) permaneceram com a artéria renal intacta. Em sete períodos de tempo sucessivos e iguais, em intervalos semanais, 12 animais de cada grupo foram submetidos à nefrectomia, com determinações morfométricas e análises histológica e ultra-estrutural. RESULTADOS: O GI apresentou redução progressiva no peso, volume e espessura cortical renal a partir do 7° dia do experimento, atingindo grau máximo no 49° dia (p < 0.05). A atrofia tubular proximal no GI ocorreu em 75/84 análises (89,2 por cento), com diferença altamente significativa entre os dois grupos a partir do 7° dia (p=0.0009) e nos demais períodos do experimento (p=0.00001). A alteração intersticial mais comum no GI foi o infiltrado, presente em 98,8 por cento, com diferença altamente significativa entre os dois grupos (p=0.00001). A análise ultra-estrutural não demonstrou lesões glomerulares, evidenciando que os glomérulos preservam sua arquitetura intacta durante a isquemia crônica. CONCLUSÃO: O modelo mostrou que a isquemia renal crônica em ratos provoca atrofia renal progressiva, com preservação da estrutura glomerular.

protective effect of co- supplementation of propolis and vitamin B6 against gentamicin induced nephrotoxicity on proximal tubules in albino rat

Thirty albino rats were used in this work. Rats were divided into five groups, six rats each. Sham control group [Group A] were injected intraperitoneaily, with 5ml of 0.9% NaCI for ten successive days. Gentamicin group [Group B] rats were injected with gentamicin, intraperitoneally, at a dose of 100 mg /kg/day for a period of 10 days. Gentamicin and Vit. B6 group [Group C] rats were injected with gentamicin in the same dose simultaneously with Vit. 36 [2.5 mg/Kg/ day] for ten successive days. Gentamicin and Propolis group [Group D] rats were intraperitoneally injected with same does of gentamicin and propolis 10% solution and given orally by gastric gavage in a dose of 100 mg/kg/day for ten days. Gentamicin, vitamin B6 and propolis group [Group E] rats were injected intraperitoneally with gentamicin, vitamin B6 with the same previous doses and propolis of the same dose orally for ten successive days. On the 11[th] day, the animals were sacrificed. Samples of blood were analyzed for blood urea and serum creatinine. Excised kidneys were fixed in 10% phosphate buffered formalin, dehydrated with ascending grades of ethanol, cleared and, then, embedded in paraffin. The paraffin embedded tissue was cut at 6 Um section and stained with haematoxyline and eosin stains. Small specimens of the kidneys were prepared for ultrathin sections and examined under electron microscope. Gentamicin administration produced a significant increase in serum creatinine [P < 0.001 Vs control] which was avoided by simultaneous vitamin B[6] and propolis treatment for 10 days [P < 0.001]. Vitamin B6 or propolis treatment reduced gentamicin induced elevation in serum creatinine, but still significant over than that of the control by day eleven. The re-suits of the blood urea nitrogen determination were similar. Light microscopic examination of the renal tissues from gentamicin treated rats revealed severe histopathological changes of the proximal convoluted tubules, whereas specimens obtained from group C, or Group D - treated rats revealed only mild changes. In group E rats treated with both vitamin B[6] and propolis, histological examination revealed a normal renal parenchymal picture without any sign of inflammatory or degenerative changes. This finding was further validated by electron microscopic examination. In electron microscopic examination, the cells of the proximal convoluted tubules from group B contained multiple large lysosomes, the mitochondria lost their cristae, some luminal microvilli were disrupted. The protective effect of vitamin B6 against gentamicin-induced nephrotoxicity was supported by electron microscopic examination. While vitamin B6 and propolis-treated rats showed milder histopathological findings similar to that of control. Proximal tubular epithelial cells were regaining normal structure. In a few areas, the tubular cells were lower with few organelles and rudimentary villi. There was little protection by propolis alone against the nephrotoxic effects of gentamicin treatment. The present study could conclude that co-administration of vitamin B6 and propolis has beneficial effects on renal preservation in gentamicin induced nephrotoxicity

A Case of IgA kappa Light Chain Deposition Disease and Combined Adult Fanconi Syndrome with Auer rod-like Intracytoplasmic Inclusions in Plasma Cells and Proximal Renal Tubular Cells / 대한진단검사의학회지

We report a case of IgA kappa light chain deposition disease and combined adult Fanconi syndrome with Auer rod-like intracytoplasmic inclusions in plasma cells and proximal renal tubular cells in a 54-yr-old female. Cytochemical stainings revealed a strong acid phosphatase activity of the inclusions and weak periodic acid-Schiff positivity, whereas the reactions for peroxidase and alpha-naphthyl acetate esterase were negative. An immunostaining verified IgA-kappa inside the plasma cells. Kidney biopsy revealed Bence Jones cast nephropathy with kappa light chain positivity, and Congo red staining was negative. Electron microscopy showed needle-shaped crystals located in tubular epithelial cells.

Gentamicin Induced Apoptosis of Renal Tubular Epithelial (LLC-PK1) Cells

Nephrotoxicity is a major limiting factor in the use of aminoglycoside antibiotics, the mechanisms for which are still speculative. To clarify the mechanisms of renal tubular cell death induced by aminoglycosides, we examined the renal proximal tubule-like cell line, LLC-PK1, after inducing apoptosis through a chronic treatment with gentamicin (GM). Changes in the expression of the Fas were also investigated. On flow cytometric analysis, 5.7 +/- 3.3% of the control cells appeared in a region of decreased forward light scatter and increased side light scatter, where both indices represent the characteristics of apoptotic cell death. Compared to the control, treatment with 10 mM of GM for 15 days significantly increased the proportion of cells in the apoptotic region to 23.9 +/- 8.5%. This finding was supported by electrophoretic analysis of the DNA extracted from the GM-treated cells, where a series of bands corresponding to integer multiples of 180 to 200 base pairs was visualized. However, the 15-day GM treatment did not cause a significant elevation in the expression of the 45 kD Fas protein, the cell surface molecule that stimulates apoptosis, by Western blot analysis. In conclusion, long-term exposure to GM induces apoptosis of the renal tubular epithelial cells, and this process may contribute to some of the aminoglycoside nephrotoxicities. Further studies are needed on the mechanism(s) of apoptosis induced by GM.

Histogênese da doença renal policística autossômica dominante: estudo imuno-histoquímico / Histogenesis of the cysts in the autosomal dominant polycystic kidney disease. Immunohistochemistry study

A histogênese dos cistos na doença policística autossômica dominante (DRPAD) foi investigada em 33 pacientes por imuno-histoquímica. A idade média dos pacientes foi 46,4 anos e a relaçäo masculino:feminino foi 16:17. A maioria dos pacientes apresentou hipertensäo arterial (88 por cento), insuficiência renal crônica (92 por cento) e hematúria (70 por cento). Aneurismas cerebrais, diverticulose colônica e cistos hepáticos e pancreáticos foram encontrados em 56 por cento dos casos. O peso médio dos 53 rins estudados foi 1468 g e o diâmetro médio dos cistos foi 4,2 cm. Em 4 casos, material histológico de 1 dos rins näo esteve disponível. Os anticorpos e lectinas utilizados para identificar os diferentes segmentos dos néfrons foram: vimentina (Vim)-epitélio parietal da cápsula glomerular (G); Lotus tetragonolubus (LTA) e anti-antígeno CD 15 (Cd 15)-túbulo proximal (TP); anti-proteína de Tamm-Horsfall (PTH)-túbulo distal (TD), e anti-antígeno epitelial de membrana (EMA), anti-citoceratina (Ck) 19, Ulex europaeus (UEA-I), Arachis hypogaea (PNA), Dolichos biflorus (DBA) e Glycine maximum (SBA)-túbulo distal (TD) e ducto coletor (DC). Em estudo piloto, analisaram-se 3 rins normais obtidos de autópsias (rins controles-RC) e áreas preservadas de 2 rins com DRPAD (áreas de controle interno-CI), obtendos-e em todos os casos coloraçäo de: G por Vim, TP-LTA e CD15; TD-PTH; TD e DC-EMA, Ck 19, UEA-I, PNA e DBA. Näo houve coloraçäo com SBA. Os 49 rins com DRPAD produziram o seguinte perfil imuno-histoquímico: i) áreas preservadas: anti-Vim-G=82 por cento; LTA-TP=96 por cento; anti-CD 15-anti-Ck 19-TD e Dc=86 por cento e 89 por cento dos casos, respectivamente; ii) Áreas císticas: LTA, anti-CD 15, anti-PTH, anti EMA e anti-Ck 19=7 por cento, 6 por cento, 18 por cento, 97 por cento e 95 por cento dos casos, respectivamente. Näo houve coloraçäo com anti-Vim. Os resultados indicaram que os cistos em casos de DRPAD têm perfil imuno-histoquímico de túbulos distais e ductos coletores.

Síndrome de Reye: relato de caso / Reyes's syndrome: a case report

Os autores apresentam e discutem o estudo de um caso de síndrome de Reye, do ponto de vista clínico, neurológico, laboratorial e das verificaçöes anátomo-patológicas