Use of scanning electron microscopy for the evaluation of intestinal epithelium integrity

Propõe-se, neste trabalho, o uso de microscopia eletrônica de varredura para avaliar perda de epitélio intestinal da mucosa intestinal de pintos machos e fêmeas submetidos a prolongado jejum pós-eclosão de água e ração. Dois segmentos do duodeno, jejuno e íleo por ave foram coletados e processados pelo método de rotina para microscopia eletrônica de varredura. Seis diferentes graus de perda de epitélio intestinal foram determinados: grau 0, vilos normais, sem extrusão; grau 1, vilos com pequenos pontos de extrusão; grau 2, vilos com perda de epitélio no ápice; grau 3, vilos com perda de epitélio na região apical; grau 4, vilos com perda de epitélio em sua metade superior; grau 5: vilos sem epitélio; grau 6: vilo quebrado. As três regiões intestinais das fêmeas apresentaram aproximadamente 90% de seus vilos normais (graus 0 e 1), enquanto nos machos ocorreu 38% de vilos normais no duodeno e jejuno e 85% no íleo. Além disso, machos apresentaram graus mais acentuados de perda de epitélio (graus 3, 4, 5 e 6) que as fêmeas (grau 3). Os dados indicaram que a mucosa intestinal de pintos machos é mais sensível a prolongado jejum pós-eclosão que a de pintos fêmeas. A microscopia eletrônica de varredura pode ser usada como um método de rotina seguro para a caracterização e quantificação de perda de epitélio intestinal.

Kinetics of cellular component in inflammatory response induced by different stimuli in the swim bladder of pacu, Piaractus mesopotamicus Holmberg 1887 (Characidae)

The present study assessed the kinetics of cell accumulation at the site of inflammation induced by thioglycolate, Escherichia coli lipopolysaccharide (LPS) and heat-inactivated Aeromonas hydrophila, in the pacu, Piaractus mesopotamicus (Characidae), swim bladder. A quantitative, as well as qualitative, assessment was done of all the cells present in the exudate at 6, 24, and 48 h (n = 8) after inoculation of inflammatory agents. The results show that the thioglycolate was the irritant to induce higher total inflammatory cell accumulation when compared to the control group, 6 h after insult (P < 0.05). Inoculation of heat-inactivated Aeromonas hydrophila induced progressive accumulation of total inflammatory cells, with cell number peaking after 24 h and being significantly higher than observed in the other groups (P < 0.05). Injection of LPS also induced greater cell accumulation when compared to the control group (P < 0.05), although in lower numbers than those induced by the other two irritants. All irritants injected induced significantly greater accumulation of lymphocytes and thrombocytes when compared to the control group (P < 0.05).

Aspectos clínicos e patológicos em frangos de corte (Gallus gallus domesticus) infectados experimentalmente com oocistos esporulados de Eimeria acervulina Tyzzer, 1929

No presente estudo, sinais clínicos e alterações patológicas foram avaliados por 30 dias em frangos de corte, linhagem Cobb, machos, com dez dias de idade, infectados com Eimeria acervulina. Foram utilizados 192 animais distribuídos em 3 grupos: grupo A inoculado com 1x10(6) oocistos esporulados; grupo B inoculado com 1x10(5) oocistos esporulados; grupo C inoculado com água destilada. Os sinais clínicos observados foram anorexia, diarréia e apatia. As alterações patológicas macroscópicas observadas foram: enterite, hiperemia seguido de congestão intestinal, excesso de exsudato mucoso no lúmen do intestino delgado, palidez e desidratação muscular, alto acúmulo de bile na vesícula biliar e deposição de gordura hepática. A atrofia de vilosidades e alta presença de células inflamatórias foram as alterações microscópicas observadas no epitélio intestinal. Na análise histopatológica do fígado observaram-se infiltrados inflamatórios e deposição de gordura. Os resultados demonstraram que frangos de corte infectados experimentalmente com E. acervulina apresentam progressivas lesões intestinais de intensidade variável e que essas anormalidades são as principais causas de redução no desenvolvimento da ave.

Dose-dependent effect of Resveratrol on bladder cancer cells: Chemoprevention and oxidative stress

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of raloxifene on the vaginal epithelium of postmenopausal women

Objective: The objective was to analyze the effect of raloxifene oil the vaginal epithelium of postmenopausal women.Study design: In this non-randomized clinical trial, 80 women (mean age = 60.6 years) were prospectively studied. Forty patients received 60 mg/day of raloxifene (RG), and 40 women constituted it non-treated control group (CG), paired by age and time since menopause. The treated group consisted of patients with osteoporosis of the lumbar spine. Those with a diagnosis of infection ill the lower genital tract and using hormone therapy (HT) up to 6 months prior to the study were excluded. Vaginal smears were collected at baseline and after 6 months of intervention. The vaginal maturation value (VMV) was determined, and counts of superficial, intermediate and parabasal cells were performed. Smears were analyzed by only one cytopathologist who was blinded to patient data. The t-test, Wilcoxon test, and Chi-Squared test were used in the statistical analysis.Results: The study groups were homogeneous regarding age, time since menopause, parity, HT use, smoking, and body mass index. No statistically significant differences were observed in VMV median values (RG, 39.7 and 35.7; CG, 50.0 and 50.0, respectively) or in the percentage of superficial, intermediate and parabasal cells between the groups at baseline and after 6 months (p > 0.05). There was no significant correlation between VMV and age, time since menopause, previous HT use, or body mass index, in either of the groups.Conclusion: Treatment with raloxifene for 6 months has no effect on the maturation of the vaginal epithelium ill postmenopausal women with osteoporosis. (C) 2008 Elsevier B.V. All rights reserved.

Effects of uracil calculi on cell growth and apoptosis in the BBN-initiated Wistar rat urinary bladder mucosa

The different potential of initiated and non-initiated urinary bladder mucosa (UBM) to develop neoplasia was quantitatively evaluated in the male Wistar rat. Initiation of carcinogenesis was accomplished with N-butyl-N- (4-hydroxybutyl) -nitrosamine (BBN). Stimuli for cell proliferation and apoptosis were obtained by exposure followed by withdrawal of 3% Uracil in the diet. The proliferation index (PI) was estimated in UBM immunostained for the proliferating nuclear cell antigen (PCNA). The apoptotic index (AI) and the density of papillary/nodular hyperplasia (PNH) were estimated in hematoxilin-eosin stained sections. PNH was the main proliferative response to the mechanical irritation by uracil, irrespective of previous initiation with BBN. Uracil exposure induced higher PI and PNH density in the initiated rats. After uracil withdrawal, there was a significant increase of the AI in both uracil-treated groups, which correlated well to the respective PNH density. However, at the end of the experiment, PNH incidence and density were significantly higher in the BBN-initiated mucosa, which also presented 18% incidence of papillomas and 27% of carcinomas. Therefore, under prolonged uracil calculi trauma, the UBM of BBN-initiated Wistar rats gives rise to epithelial proliferative lesions that progress to neoplasia through acquired resistance to apoptosis. (C) 1999 Wiley-Liss, Inc.

Chemopreventive property of dietary ginger in rat urinary bladder chemical carcinogenesis

The modifying potential of ginger on the development of preneoplasia and tumors in the male Wistar rat urinary bladder was investigated in a 36-week-long initiation-promotion assay for chemical carcinogenesis. Groups G1 to G3 were given 0.05% N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN) in drinking water for 5 weeks and a 3% uracil meal for the subsequent 3 weeks. Groups G4 and G5 were treated with 3% uracil only for the same period. After these steps, groups G2, and G3 and G4 were fed for 26 weeks a ginger extract mixed at 0.5 and 1.0% in a basal diet, respectively. Thirty six weeks after the beginning of the experiment all rats were killed. The multiplicity of urothelial lesions (hyperplasia and neoplasia) was significantly lower (P = 0.013) in group G3 than in groups G1 and G2. The results suggest that 1.0% ginger meal exerts a protective effect on the post-initiation stage of rat chemically-induced urothelial carcinogenesis.

Effects of Diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea] on the urinary bladder of male Wistar rats

Diuron (3-(3,4-dichlorophenyl)-1,1-dimethylurea) is a substituted urea herbicide widely used on agricultural crops such as soy, cotton and sugar cane. In a previous long-term study this herbicide exerted carcinogenic activity on the urinary bladder mucosa of male Wistar rats. In general, the genotoxic and mutagenic potentials of Diuron are considered to be negative. The present study aimed to evaluate the mode of action of Diuron on the urinary bladder mucosa of male Wistar rats. Six-week old male Wistar rats were fed pelleted Nuvilab diet mixed with Diuron at 125, 500 and 2500 ppm. As a positive control, 8.3% sodium saccharin (NaS) was fed in the diet. Preceding the sacrifice of the animals at the 20th week, urinary pH was measured and the genotoxic potential of Diuron was evaluated by the comet assay. Histological urothelial lesions in the urinary bladder and in the renal pelvis mucosa, cell proliferation/apoptosis evaluations, and scanning electron microscopy (SEM) of the urinary bladder mucosa were also performed. No DNA changes were found in urothelial or peripheral blood cells, and urinary pH was comparable to controls in all Diuron groups. In the urinary bladder urothelium, the incidence of simple hyperplasia (SH) by light microscopy was significantly increased (7/10; p < 0.005) in the 2500 ppm Diuron group but not at the lower doses. By SEM, three of five animals treated with 2500 ppm Diuron showed urothelial cell necrosis and hyperplasia. In the renal pelvis, the incidence of SH was significantly increased in the Diuron 500 and 2500 ppm and in the NaS 8.3% groups. Cell proliferation was significantly increased in the Diuron 2500 ppm, (p < 0.05) and NaS 8.3% (p < 0.05) groups. The results indicate that a high dietary concentration of Diuron is associated with urothelial necrosis and continuous regenerative cell proliferation that leads to urothelial hyperplasia. (c) 2006 Elsevier B.V.. All rights reserved.

Morphologic changes in the urethral epithelium in an ethanol-drinking rat strain (UChA and UChB)

The extreme use of ethanol causes metabolic and pathologic changes in testes and urogenital system in different animal species. The enzyme alcohol dehydrogenase (ADH) catalyses the conversion of ethanol into carcinogenic metabolite acetaldehyde which is partly excreted into the urine. However, papers relating the chronic ethanol consumption to the urethral morphology are unknown. This work evaluates the toxic effect of the chronic ethanol ingestion on the urethral epithelium of UChA and UChB rats. Conventional techniques of histology, histochemistry, immunohistochemistry and ultrastructural analysis were used. The analysis showed the presence of lipid drops and intercellular spaces in the epithelial cells in the urethra of UChA and UChB rats compared to control rats. Urethral neuroendocrine cell were observed and characterized for presenting vesicles containing electron-dense granules associated with nervous fibers. We conclude that the chronic consumption of ethanol induces the presence lipid drops in the epithelial cells of the urethra of UChA and UChB rats. The NE cells of the urethra of UChA and UChB rats did not show alterations under chronic effect of the ethanol. (C) 2007 Elsevier Ltd. All rights reserved.

Absence of DNA damage in multiple organs (blood, liver, kidney, thyroid gland and urinary bladder) after acute fluoride exposure in rats

Fluoride has been widely used in dentistry as a caries prophylactic agent. However, there has been some speculation that excess fluoride could cause an impact on genome integrity. In the current study, the potential DNA damage associated with exposure to fluoride was assessed in cells of blood, liver, kidney, thyroid gland and urinary bladder by the single cell gel (comet) assay. Male Wistar rats aging 75 days were distributed into seven groups: Groups 1 (control), 2, 3, 4, 5, 6 and 7 received 0 (deionized water), 10, 20, 40, 60, 80 and 100 mgF/Kg body weight from sodium fluoride (NaF), respectively, by gastrogavage. These groups were killed at 2 h after the administration of the fluoride doses. The level of DNA strand breaks did not increase in all organs evaluated and at all doses of NaF tested, as depicted by the mean tail moment. Taken together, our results suggest that oral exposure to NaF did not result in systemic genotoxic effect in multiple organs related to fluoride toxicity. Since DNA damage is an important step in events leading to carcinogenesis, this study represents a relevant contribution to the correct evaluation of the potential health risk associated with chemical exposure.

Potential effects of the herbicide Diuron on mammary and urinary bladder two-stage carcinogenesis in a female Swiss mouse model

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Toxicogenomic activity of gemcitabine in two TP53-mutated bladder cancer cell lines: special focus on cell cycle-related genes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)