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1.
Epidemiol Infect ; 142(7): 1411-21, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24029072

RESUMO

In Ontario, Canada, the number of Salmonella Enteritidis (SE) cases increased over the years 2005-2010. A population-based case-control study was undertaken from January to August 2011 for the purpose of identifying risk factors for acquiring illness due to SE within Ontario. A total of 199 cases and 241 controls were enrolled. After adjustment for confounders, consuming any poultry meat [adjusted odds ratio (aOR) 2·24, 95% confidence interval (CI) 1·31-3·83], processed chicken (aOR 3·32, 95% CI 1·26-8·76) and not washing hands following handling of raw eggs (OR 2·82, 95% CI 1·48-5·37) were significantly associated with SE infection. The population attributable fraction was 46% for any poultry meat consumption and 10% for processed chicken. Poultry meat continues to be identified as a risk factor for SE illness. Control of SE at source, as well as proper food handling practices, are required to reduce the number of SE cases.


Assuntos
Infecções Comunitárias Adquiridas/epidemiologia , Infecções por Salmonella/epidemiologia , Salmonella enteritidis/isolamento & purificação , Adolescente , Adulto , Animais , Estudos de Casos e Controles , Galinhas , Criança , Pré-Escolar , Infecções Comunitárias Adquiridas/microbiologia , Ovos/microbiologia , Comportamento Alimentar , Feminino , Desinfecção das Mãos , Humanos , Lactente , Masculino , Carne/microbiologia , Pessoa de Meia-Idade , Análise Multivariada , Razão de Chances , Ontário/epidemiologia , Fatores de Risco , Infecções por Salmonella/microbiologia , Inquéritos e Questionários , Adulto Jovem
2.
Vox Sang ; 104(1): 46-54, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22827736

RESUMO

BACKGROUND AND OBJECTIVES: G-CSF-mobilized peripheral blood stem cells have long replaced marrow as the major source for allogeneic transplants. Conclusive evidence questioning the long-term safety of G-CSF for donors has not been provided, but the cumulative number of followed donors remains insufficient to rule out rare adverse events. A long-term active follow-up study of G-CSF-mobilized healthy volunteer donors was therefore performed. PATIENTS AND METHODS: Two hundred and three successive donors were evaluated pre-apheresis, subjected to G-CSF-mobilization/apheresis, and actively followed for 5 years by the same physicians and laboratories. Follow-up laboratory work included standard biochemical/haematological tests and T-cell phenotyping. RESULTS: Donor epidemiology was typical for reported stem cell donor cohorts. Acute adverse effects of G-CSF and apheresis were mild and transient, consistent with the previous reports. Mean circulating CD34(+) cells after nine doses of G-CSF were 124 per µl. Other biochemical/haematological parameters were also altered, consistent with G-CSF treatment. Spleen enlargement was modest. At first follow-up, all clinical and laboratory parameters had normalized. Leucocyte/lymphocyte counts and CD4/CD8 ratios were the same as during premobilization work-up and remained unchanged throughout. A single severe but likely unrelated adverse event, a case of papillary thyroid carcinoma, was reported. CONCLUSION: The studies add an observation time of almost 500 donor years to the growing body of evidence of the long-term safety of G-CSF for allogeneic donor stem cell mobilization.


Assuntos
Remoção de Componentes Sanguíneos/métodos , Segurança do Sangue , Fator Estimulador de Colônias de Granulócitos/metabolismo , Mobilização de Células-Tronco Hematopoéticas/métodos , Adulto , Antígenos CD34/biossíntese , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD8-Positivos/citologia , Feminino , Filgrastim , Seguimentos , Fator Estimulador de Colônias de Granulócitos/farmacologia , Humanos , Estudos Longitudinais , Contagem de Linfócitos , Masculino , Fenótipo , Estudos Prospectivos , Proteínas Recombinantes/farmacologia , Células-Tronco/citologia , Linfócitos T/citologia , Doadores de Tecidos , Transplante Homólogo/métodos
3.
Physiol Int ; 2021 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-33835941

RESUMO

Aging is a multifactorial process, which is considered as a decline over time. It is increasingly clear that there is a gender difference in aging and in the prevalence of age-related diseases as well. We aimed to examine the effects of the aging process in the colonic tissue of female Wistar rats aged 10 weeks (young) and 13 months (middle-aged) at an early stage, according to three main symptoms associated with aging: a decrease in the efficacy of the proteasome and muscle function and an increase in oxidative stress. The aging process was found to cause a significant decrease in ubiquitin C-terminal hydrolase ligase (UCHL-1) and a significant increase in 3-nitrotyrosine (3-NT), total glutathione (GSH), calcium (Ca2+), calcitonin gene-related peptide (CGRP) and superoxide dismutase (SOD) activity in middle-aged animals. In summary, it is suggested that the reduced activity of the proteasomal degradation system may be the result of the diminished expression of the UCHL-1 enzyme and the decreased levels of ubiquitin; furthermore, we found some key targets which may help to better understand the fundamental aging process.

5.
J Comp Pathol ; 171: 38-52, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31540624

RESUMO

Psittacines (e.g. parrots, macaws and cockatoos) are common companion animals that are also kept in zoos and private breeding collections. Despite this popularity, long-term, comprehensive studies of diagnostic data from captive psittacines are rare. This study was conducted to assess trends in disease prevalence and to describe causes of morbidity and mortality in psittacines submitted for post-mortem examination to the veterinary hospital and diagnostic laboratory at the University of Guelph, Ontario, Canada. Post-mortem reports of 1,850 psittacines from 1998 to 2017 were assessed and included 110 species from 45 genera. Birds were often diagnosed with infectious disease processes (n = 823; 44.5%), including viral (n = 428; 23.1%), bacterial (n = 284; 15.4%) and fungal (n = 161; 8.7%). Non-infectious disease processes (n = 1,076; 58.2%) were most commonly degenerative (n = 465; 25.1%), metabolic (n = 392; 21.2%) or haemodynamic (n = 270; 14.6%). Exploratory statistical analyses, used to guide further research, revealed significant correlations and associations among disease processes and genera, age categories and sex. This 19-year retrospective study is the first to be conducted in Canada for psittacine birds and provides a broad overview of disease prevalence that can be used as a baseline to inform other studies addressing common and uncommon diseases affecting these birds in the future.


Assuntos
Doenças das Aves/epidemiologia , Infecções/veterinária , Psittaciformes , Animais , Doenças das Aves/diagnóstico , Infecções/diagnóstico , Infecções/epidemiologia , Ontário/epidemiologia , Prevalência , Estudos Retrospectivos
6.
Br J Pharmacol ; 153(5): 983-91, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18157165

RESUMO

BACKGROUND AND PURPOSE: Leukotriene B(4) (LTB(4)), formed by the sequential actions of the 5-lipoxygenase (5-LO) and leukotriene A(4) hydrolase (LTA(4)H), is a pro-inflammatory mediator implicated in the pathogenesis of inflammatory bowel disease. However, inhibitors of 5-LO have not proved to be consistent in their therapeutic efficacy in colitis. Another approach to inhibiting LTB(4) synthesis is through the use of inhibitors of LTA(4)H, such as the novel, potent and selective compound, JNJ 26993135. EXPERIMENTAL APPROACH: The effect of oral administration of JNJ 26993135 has been evaluated in a rat model of colitis provoked by colonic instillation of trinitrobenzenesulphonic acid (TNBS). The extent and severity of the macroscopic inflammatory response, the colonic levels of myeloperoxidase (MPO) and LTB(4) and of the pro-inflammatory cytokines, tumour necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) were measured. KEY RESULTS: Oral administration of JNJ 26993135 (5, 15 and 30 mg kg(-1), twice a day) dose-dependently reduced both the extent and intensity of the colonic inflammatory damage observed 3 days after TNBS challenge. JNJ 26993135 also dose-dependently reduced the elevated colonic levels of LTB(4), as well as the inflammatory biomarkers, MPO, IL-6 and TNF-alpha. This dosing regimen was supported by the pharmacokinetic profile of JNJ 26993135, along with the demonstration of the inhibition of ex vivo production of LTB(4) in whole blood following oral administration. CONCLUSIONS AND IMPLICATIONS: These results with JNJ 26993135 in the rat TNBS model support the role of LTB(4) in colitis and the potential value of targeting LTA(4)H for the treatment of inflammatory bowel diseases.


Assuntos
Benzotiazóis/farmacologia , Colite/tratamento farmacológico , Inibidores Enzimáticos/farmacologia , Epóxido Hidrolases/antagonistas & inibidores , Inflamação/tratamento farmacológico , Piperidinas/farmacologia , Administração Oral , Animais , Benzotiazóis/administração & dosagem , Benzotiazóis/farmacocinética , Colite/induzido quimicamente , Colite/fisiopatologia , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Sistemas de Liberação de Medicamentos , Inibidores Enzimáticos/administração & dosagem , Inibidores Enzimáticos/farmacocinética , Inflamação/etiologia , Interleucina-6/metabolismo , Masculino , Peroxidase/efeitos dos fármacos , Peroxidase/metabolismo , Piperidinas/administração & dosagem , Piperidinas/farmacocinética , Ratos , Ratos Wistar , Índice de Gravidade de Doença , Ácido Trinitrobenzenossulfônico , Fator de Necrose Tumoral alfa/efeitos dos fármacos , Fator de Necrose Tumoral alfa/metabolismo
7.
Acta Neurochir (Wien) ; 150(3): 265-71, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18288441

RESUMO

The effects of the non-peptide vasopressin V(2) receptor antagonist 5-dimethylamino-1-[4-(2-methylbenzoylamino)benzoyl]-2,3,4,5-tetrahydro-1H-benzazepine hydrochloride (OPC-31260) on the cerebral oedema induced by general cerebral hypoxia were studied in rats. The general cerebral hypoxia was produced by bilateral common carotid ligation in Sprague-Dawley rats of the CFY strain. By 6 h after the ligation, half of the rats had died, but the survival rate was significantly higher following OPC-31260 administration. Electron microscopic examinations revealed typical ischaemic changes after the carotid ligation. The carotid ligation increased the brain contents of water and Na(+) and enhanced the plasma vasopressin level. The increased brain water and Na(+) accumulation was prevented by OPC-31260 administration, but the plasma vasopressin level was further enhanced by OPC-31260. These results demonstrate the important role of vasopressin in the development of the disturbances in brain water and electrolyte balance in response to general cerebral hypoxia. The carotid ligation-induced cerebral oedema was significantly reduced following oral OPC-31260 administration. The protective mechanism exerted by OPC-31260 stems from its influence on the renal vasopressin V(2) receptors. These observations might suggest an effective approach to the treatment of global hypoxia-induced cerebral oedema in humans.


Assuntos
Antagonistas dos Receptores de Hormônios Antidiuréticos , Benzazepinas/farmacologia , Edema Encefálico/tratamento farmacológico , Edema Encefálico/fisiopatologia , Isquemia Encefálica/complicações , Isquemia Encefálica/fisiopatologia , Animais , Benzazepinas/uso terapêutico , Água Corporal/efeitos dos fármacos , Água Corporal/metabolismo , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/patologia , Edema Encefálico/etiologia , Isquemia Encefálica/patologia , Modelos Animais de Doenças , Rim/efeitos dos fármacos , Rim/metabolismo , Masculino , Microscopia Eletrônica de Transmissão , Ratos , Receptores de Vasopressinas/metabolismo , Sódio/metabolismo , Taxa de Sobrevida , Resultado do Tratamento , Vasopressinas/metabolismo , Equilíbrio Hidroeletrolítico/efeitos dos fármacos , Equilíbrio Hidroeletrolítico/fisiologia
8.
Surg Endosc ; 21(6): 1020-2, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17332958

RESUMO

BACKGROUND: Intraoperative cholangiography (IOC) during laparoscopic cholecystectomy (LC) is used to assess the anatomy of the biliary tree and to detect any stones contained within it. Intraoperative cholangiography may be performed either routinely or more selectively in cases where there is a high suspicion of choledocholithiasis or for those patients whose anatomy appears unclear at operation [8]. In cases where significant inflammation is present, the cystic duct may be short, thickened, or dilated and thus difficult to manipulate to obtain a satisfactory IOC. METHODS: We describe a safe, simple, reliable technique to control the "difficult" cystic duct during IOC with a vascular vessel loop instead of a surgical clip to obtain good control and avoiding extravasation of dye during IOC. The feasibility, safety, and results of this technique are described. RESULTS: During a 1-year period, this technique has been used in 10 patients, and it was successful in all attempted cases, with a good quality IOC obtained on the first attempt. The cystic duct was then occluded in all cases using a Vicryl "0" endoloop. One patient had a common bile duct stone and this patient received postoperative endoscopic retrograde pancreatography (ERCP). All patients were discharged home with no complications. In cases where a short, thickened, or dilated cystic duct was present, ductal control during IOC was easily obtained using a vascular vessel loop. CONCLUSIONS: This is a safe, reliable, less traumatic, readily available, and inexpensive method that provides a secure way of handling the "difficult" cystic duct.


Assuntos
Colangiografia/métodos , Colecistectomia Laparoscópica/métodos , Ducto Cístico/cirurgia , Doenças do Sistema Digestório/cirurgia , Adulto , Idoso , Estudos de Viabilidade , Feminino , Humanos , Cuidados Intraoperatórios , Masculino , Pessoa de Meia-Idade
9.
Homo ; 68(5): 398-409, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29066093

RESUMO

Abdominal fat accumulation is a major risk factor for cardiometabolic morbidity and mortality. The purpose of the study is to assess the possibility of developing accurate estimation equations based on body measurements to determine total abdominal (TFA), subcutaneous (SFA) and visceral fat area (VFA). Hungarian volunteers (n=198) aged between 20 and 81 years were enrolled in the study, which was conducted between July and November 2014. All persons underwent anthropometric measurements and computer tomographic (CT) scanning. Sex-specific multiple linear regression analyses were conducted in a subgroup of 98 participants to generate estimation models, then Bland-Altman's analyses were applied in the cross-validation group to compare their predictive efficiency. The variables best predicting VFA were hip circumference, calf circumference and waist-to-hip ratio (WHR) for males (R2=0.713; SEE=5602.1mm2) and sagittal abdominal diameter (SAD), WHR, thigh circumference and triceps skinfold for females (R2=0.845; SEE=3835.6mm2). The SFA prediction equation included SAD, thigh circumference and abdominal skinfold for males (R2=0.848; SEE=4124.1mm2), body mass index and thigh circumference for females (R2=0.861; SEE=5049.7mm2). Prediction accuracy was the highest in the case of TFA: hip circumference and WHR for males (R2=0.910; SEE=5637.2mm2), SAD, thigh circumference and abdominal skinfold for females (R2=0.915; SEE=6197.5mm2) were used in the equations. The results suggested that deviations in the predictions were independent of the amount of adipose tissue. Estimation of abdominal fat depots based on anthropometric traits could provide a cheap, reliable method in epidemiologic research and public health screening to evaluate the risk of cardiometabolic events.


Assuntos
Gordura Abdominal/anatomia & histologia , Adiposidade , Antropometria/métodos , Gordura Abdominal/diagnóstico por imagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Bioestatística , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade Abdominal/diagnóstico por imagem , Obesidade Abdominal/patologia , Fatores de Risco , Tomografia Computadorizada por Raios X , Relação Cintura-Quadril , Adulto Jovem
10.
Neuroscience ; 141(4): 1919-24, 2006 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-16814932

RESUMO

Effects of chronic estrogen treatment on the survival rate of newly integrated interneurons were studied in the olfactory bulb of adult (250-300 g) female rats. Ovariectomized rats received 17-beta estradiol dissolved in sesame oil (i.p., 100 microg/100 g body weight [b.w.]) during six consecutive days, and on day 6 they were also injected with the mitotic marker 5-bromo-2-deoxyuridine (BrdU, i.p., 50 mg/kg b.w.) in every 2 hours during 8 hours. After 21 days of survival animals were killed and the density of BrdU-immunoreactive cells was analyzed in the granule cell and glomerular layer both in the main and accessory olfactory bulb. A significant decrease was found in the density of BrdU-labeled cells in both layers examined in the accessory olfactory bulb of ovariectomized and estradiol-treated rats when compared with those of ovariectomized and vehicle-treated animals. In the main olfactory bulb, in contrast, no difference was observed in the density of BrdU-immunoreactive cells in either of the two layers. Our results suggest that cells destined to the glomerular and granule cell layers react in the same way to chronic estrogen treatment, and the effect of estradiol is region specific, at least, within the olfactory bulb. 17-Beta estradiol reduces the density of newly generated cells in the accessory olfactory bulb, an area involved in the perception of pheromones, thus having a role in regulating sexual behavior, while the rate of integration and survival of newly born cells in the first relay station of the main olfactory pathway, i.e. the main olfactory bulb, remains unchanged.


Assuntos
Bromodesoxiuridina/metabolismo , Estrogênios/farmacologia , Neurônios/efeitos dos fármacos , Bulbo Olfatório/citologia , Análise de Variância , Animais , Contagem de Células/métodos , Feminino , Imuno-Histoquímica/métodos , Neurônios/metabolismo , Bulbo Olfatório/efeitos dos fármacos , Ovariectomia/métodos , Ratos , Ratos Wistar , Fatores de Tempo
11.
J Immunol Methods ; 167(1-2): 245-51, 1994 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-8308280

RESUMO

Different Percoll density gradients were used to purify granulocytes from Long-Evans, Fischer, Sprague-Dawley, and Fischer/Long-Evans hybrid rats. Three different discontinuous gradient types were developed which permitted the separation of polymorphonuclear leukocytes (PMNLs) from the peripheral blood of the different rat strains. Our purification techniques were compared to each other in terms of purity and yield. Purities of 97.7 +/- 0.6%, 97.0 +/- 1.1%, 96.4 +/- 1.2% and 96.7 +/- 1.1% were achieved for the granulocyte fractions of LE, F344, SD and FL/F1 rats, respectively. The superoxide production of the isolated cells was also investigated and it was established that the granulocytes could be activated by phorbol-12-myristate-13-acetate (PMA).


Assuntos
Separação Celular , Neutrófilos , Animais , Separação Celular/métodos , Centrifugação com Gradiente de Concentração , Quimera , Neutrófilos/efeitos dos fármacos , Ratos , Ratos Endogâmicos F344 , Ratos Endogâmicos , Ratos Sprague-Dawley , Superóxidos/metabolismo , Acetato de Tetradecanoilforbol/farmacologia
12.
Cancer Lett ; 139(2): 173-6, 1999 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-10395175

RESUMO

Epidemiological data seem to be equivocal on the probable increase in cancer incidence in populations exposed to asbestos-fibre contaminated drinking water. Although animal experiments failed to demonstrate carcinogenicity of oral asbestos exposure, the large surface area of the fibres, however, creates the possibility of cogenotoxic action with adsorbed water-borne organics. In our animal model, rats were gavaged with untreated UICC crocidolite and anthophyllite fibres and fibres that had been allowed to adsorb benzo[a]pyrene molecules from aqueous solutions. Peritoneal macrophages and intestine, parietal peritoneum and omentum samples were obtained from the animals after 24 h. The alkaline single-cell microgel electrophoresis assay (comet assay) was performed on cells isolated from the solid tissues. Tail moment was applied as a basis of evaluation following image analysis. Our results indicate high levels of DNA strand breaks in the cells prepared from the omentum and intestine. We could also demonstrate a significant potentiating effect of the adsorbed carcinogen on the induction of DNA damage in the omentum. The parietal peritoneum and macrophages were not involved in the early genotoxic alterations under study. Our results support the molecular model of asbestos cocarcinogenesis, including both asbestos-induced deletions and mutations caused by a mutagen carried by the same fibres.


Assuntos
Amiantos Anfibólicos/toxicidade , Benzo(a)pireno/toxicidade , Carcinógenos/toxicidade , Cocarcinogênese , Dano ao DNA , Animais , DNA/análise , DNA/efeitos dos fármacos , DNA/metabolismo , Modelos Animais de Doenças , Sinergismo Farmacológico , Eletroforese/métodos , Feminino , Concentração de Íons de Hidrogênio , Intestinos/efeitos dos fármacos , Macrófagos Peritoneais/efeitos dos fármacos , Omento , Especificidade de Órgãos , Peritônio/efeitos dos fármacos , Ratos , Ratos Endogâmicos F344
13.
Cancer Lett ; 105(2): 181-5, 1996 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-8697442

RESUMO

Early cytogenetic action of oral exposure to UICC anthophyllite, an amphibole type of asbestos, was studied in Fischer-344 rats. The animals were gavaged with a suspension of untreated fibres (50 mg/kg) and fibres which had been allowed to adsorb benzo[alpha]pyrene molecules from aqueous solutions of 0.25-2.5 micrograms/ml. HPLC measurements indicated effective adsorption of the benzo[alpha]pyrene molecules on the fibres. The authors consider this system a suitable model for the drinking of water containing asbestos fibres and organic micropollutants. The formation of micronuclei and sister chromatid exchanges was studied in bone marrow samples taken from animals 24 h after oral administration of suspensions. Whereas anthophyllite fibres failed to induce cytogenetic alterations, fibres pretreated with the polycyclic aromatic solutions caused dose-dependent increase in the sister chromatid exchange frequencies. The observed cytogenetic impact can be explained by a local action of carcinogen molecules accumulated and subsequently transported. The results support the hypothesis that epidemiological evidence of carcinogenicity of asbestos in potable water may rather be explained by cogenotoxic action of the asbestos fibres and biologically active organic micropollutants adsorbed on their surface.


Assuntos
Amiantos Anfibólicos/toxicidade , Medula Óssea/efeitos dos fármacos , Carcinógenos/toxicidade , Administração Oral , Animais , Amiantos Anfibólicos/administração & dosagem , Amiantos Anfibólicos/química , Benzo(a)pireno/química , Células da Medula Óssea , Carcinógenos/administração & dosagem , Cromatografia Líquida de Alta Pressão , Citogenética/métodos , Eritrócitos/efeitos dos fármacos , Feminino , Hematopoese/efeitos dos fármacos , Mitose/efeitos dos fármacos , Testes de Mutagenicidade , Ratos , Ratos Endogâmicos F344 , Troca de Cromátide Irmã/efeitos dos fármacos
14.
Cancer Lett ; 60(3): 199-203, 1991 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-1756509

RESUMO

In vivo rodent cytogenetics may provide an important basis for an animal model for the assessment of the carcinogenic potential of antitumor drugs in man. In this paper, genotoxic alterations (i.e. sister chromatid exchanges and micronuclei) caused by different cytostatic protocols in CBA/Ca mice are described. The strongest sister chromatid exchange inducing effects were shown by the ABVD (doxorubicin-dacarbazine-bleomycinvinblastine) group and combinations containing cyclophosphamide. Compounds which affect the mitotic spindle induced only micronuclei, but not sister chromatid exchanges.


Assuntos
Antineoplásicos/toxicidade , Carcinógenos/toxicidade , Testes para Micronúcleos , Mutagênicos/toxicidade , Troca de Cromátide Irmã/efeitos dos fármacos , Animais , Medula Óssea/efeitos dos fármacos , Medula Óssea/patologia , Relação Dose-Resposta a Droga , Humanos , Masculino , Metáfase , Camundongos , Camundongos Endogâmicos CBA , Testes de Mutagenicidade
15.
Cancer Lett ; 128(2): 165-9, 1998 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-9683278

RESUMO

Recently, there has been concern that ingested asbestos may cause an increase in cancer incidence in populations exposed to fibre-contaminated drinking water. Although animal experiments failed to demonstrate carcinogenicity of the oral asbestos exposure, the high adsorption capacity of the fibres creates the possibility of cocarcinogenic action with adsorbed organics. In a simple in vivo model we demonstrated earlier that UICC crocidolite and anthophyllite asbestos fibres were able to adsorb carcinogen molecules from aqueous solutions. When orally administered, these fibres increased the sister chromatid exchange frequency in bone marrow cells of rats. In the present study we tried to follow the desorption and metabolization processes of carcinogenic benzo[a]pyrene molecules transported by the ingested fibres using the highly sensitive Salmonella/Ames mutagenicity assay. The bacterial test was performed on concentrated serum and urine samples of the treated animals by using the TA98 and 100 strains in the presence and absence of liver microsomal and deconjugating enzymes. All sets of urine and serum samples failed to show mutagenic activity indicating a lack of both desorption in the serum and the ability of the liver to metabolize. Considering our results, the cytogenetic impact demonstrated earlier in the bone marrow can be explained by a local action of accumulated and transported carcinogen molecules.


Assuntos
Amiantos Anfibólicos/toxicidade , Benzo(a)pireno/toxicidade , Carcinógenos/toxicidade , Cocarcinogênese , Mutagênicos/toxicidade , Animais , Amiantos Anfibólicos/metabolismo , Asbesto Crocidolita/metabolismo , Asbesto Crocidolita/toxicidade , Benzo(a)pireno/metabolismo , Carcinógenos/metabolismo , Feminino , Testes de Mutagenicidade , Mutagênicos/metabolismo , Ratos , Ratos Endogâmicos F344
16.
J Physiol Paris ; 94(1): 63-6, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10761691

RESUMO

Vasopressin is a stress hormone released from the posterior pituitary. In humans suffering from central diabetes insipidus, this release of vasopressin is diminished. It was shown previously that the congenitally vasopressin-deficient Brattleboro homozygous rat is less sensitive to various ulcerogenic stimuli. In this study, we investigated the incidence of gastroduodenal ulceration in vasopressin deficient patients. Data on patients aged 20-70, hospitalized in Hungary between 1992 and 1995 were compared with those on the total population in this age group (6,681,020 in 1994). Subjects with central diabetes insipidus were selected separately (815 cases). Gastroduodenal ulceration was compared in subjects with an intact vasopressin release and vasopressin-deficient patients. The frequencies of gastroduodenal ulceration were also examined separately in male and female subjects. In the total population, the frequency of gastroduodenal ulceration was lower in vasopressin-deficient cases (2.22% versus 0.61%; P < 0.005). Among normal-vasopressin subjects, males have a higher risk of gastroduodenal ulceration than females (3.04% versus 1.46%, respectively; P < 0.001). Among vasopressin-deficient subjects, a similar male:female ratio was observed, but it was not significant (P = 0.36). In comparison to the normal-vasopressin population, the incidence of gastroduodenal ulceration was reduced among vasopressin-deficient males and females by 77% (P < 0.01) and by 82% (P < 0.05), respectively. In conclusion, endogenous vasopressin has a significant harmful action towards the human gastroduodenal mucosa. Peptide and non-peptide vasopressin receptor antagonists might have a potential therapeutic benefit in the treatment (as an adjuvant) and prevention of gastroduodenal ulceration.


Assuntos
Úlcera Duodenal/prevenção & controle , Úlcera Gástrica/prevenção & controle , Vasopressinas/deficiência , Adulto , Idoso , Úlcera Duodenal/epidemiologia , Úlcera Duodenal/etiologia , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Razão de Chances , Valores de Referência , Fatores de Risco , Distribuição por Sexo , Úlcera Gástrica/epidemiologia , Úlcera Gástrica/etiologia , Vasopressinas/metabolismo
17.
J Physiol Paris ; 93(6): 491-4, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10672994

RESUMO

The actions of the female sex steroid, oestradiol on cysteamine-induced mucosal ulceration has been evaluated in female Wistar rats. Administration of cysteamine (400 mg x kg(-1), s.c.) provoked macroscopic gastroduodenal mucosal injury (assessed planimetrically) and an increase in microvascular permeability (assessed by the extravasation of radiolabeled albumin) in the stomach and duodenum, determined 24 h later. Ovariectomy (2 weeks before cysteamine) reduced gastroduodenal macroscopic injury, and albumin extravasation following cysteamine challenge. Administration of oestradiol (1-5 mg x kg(-1), as an i.m. depot 1 week before cysteamine) dose-dependently augmented gastric and duodenal macroscopic mucosal lesions and microvascular permeability provoked by cysteamine. These findings indicate that oestradiol can exacerbate gastroduodenal ulceration and microvascular injury.


Assuntos
Cisteamina , Estradiol/farmacologia , Úlcera Péptica/induzido quimicamente , Úlcera Péptica/patologia , Animais , Feminino , Mucosa Gástrica/efeitos dos fármacos , Mucosa Gástrica/patologia , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/patologia , Ovariectomia , Ratos , Ratos Wistar
18.
Regul Pept ; 98(1-2): 49-54, 2001 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-11179778

RESUMO

The effects of dopamine (DA) or DA-active drugs on the synthesis of neurohypophyseal (NH) hormones were studied in 13-14 day cultures of isolated NH tissue from rats. The following DA-active compounds were used (10(-6) M in each medium): DA, apomorphine (APM), Pro-Lys-Gly (PLG), butaclamol (B), haloperidol (HP), chlorpromazine (CPZ) and sulpiride (SP). The oxytocin (OT) and vasopressin (VP) contents of the condensed media were determined by RIA after a 1 or 2 h incubation. Significantly increased contents of OT and VP were detected in the tissue culture media following DA, APM or PLG administration. This elevation of NH hormone production could be blocked by previous administration of B or the DA receptor antagonists HP, CPZ or SP. The application of B after DA agonists proved ineffective. The results indicate that NH hormone production can be directly influenced by the DA-ergic system. The DA-ergic control of NH hormone secretion in rats can occur independently of the hypothalamus, at the level of the posterior pituitary.


Assuntos
Antagonistas de Dopamina/farmacologia , Dopamina/farmacologia , Ocitocina/metabolismo , Hipófise/metabolismo , Vasopressinas/metabolismo , Animais , Apomorfina/farmacologia , Butaclamol/farmacologia , Clorpromazina/farmacologia , Técnicas de Cultura , Agonistas de Dopamina/farmacologia , Sinergismo Farmacológico , Haloperidol/farmacologia , Masculino , Neuroglia/efeitos dos fármacos , Neuroglia/metabolismo , Ocitocina/efeitos dos fármacos , Hipófise/efeitos dos fármacos , Ratos , Ratos Wistar , Sulpirida/farmacologia , Vasopressinas/efeitos dos fármacos
19.
Eur J Pharmacol ; 364(2-3): 115-22, 1999 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-9932713

RESUMO

The effects of the non-peptide vasopressin V2 receptor antagonist, 5-dimethylamino-1-[4-(2-methylbenzoylamino)benzoyl]-2,3,4,5-tetrah ydro-1 H-benzazepine hydrochloride (OPC-31260) on the cerebral oedema induced by subarachnoid haemorrhage were studied in rats. Subarachnoid haemorrhage induced significant water retention after water loading, increased the brain content of water and Na+ and increased plasma vasopressin levels. The water retention and brain water and Na+ accumulation were prevented by OPC-31260 administration, but the plasma vasopressin levels were further enhanced by OPC-31260. These results demonstrate the important role of vasopressin in the development of antidiuresis and disturbances in brain water and electrolyte balance in response to subarachnoid haemorrhage. The subarachnoid haemorrhage-induced cerebral oedema was significantly reduced following oral OPC-31260 administration. The protective mechanism exerted by OPC-31260 stems from its influence on renal tubular function: it blocks the renal vasopressin V2 receptors. These observations might suggest a new, effective approach to the treatment of subarachnoid haemorrhage-induced cerebral oedema in humans.


Assuntos
Antagonistas dos Receptores de Hormônios Antidiuréticos , Benzazepinas/farmacologia , Edema Encefálico/prevenção & controle , Hemorragia Subaracnóidea/fisiopatologia , Animais , Água Corporal/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/fisiopatologia , Edema Encefálico/fisiopatologia , Diurese/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ingestão de Líquidos/efeitos dos fármacos , Masculino , Concentração Osmolar , Potássio/metabolismo , Ratos , Ratos Wistar , Sódio/metabolismo , Micção/efeitos dos fármacos , Urina , Vasopressinas/sangue , Vasopressinas/efeitos dos fármacos
20.
Eur J Pharmacol ; 337(2-3): 275-8, 1997 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-9430425

RESUMO

The sexual dimorphism of gastroduodenal ulceration is suggested on the basis of clinical and experimental observations. This difference probably relates to the actions of endogenous sexual steroids. In the present study, the role of testosterone was evaluated in the generation of gastroduodenal mucosal injury provoked by cysteamine (400 mg/kg, s.c.). We found that macroscopic mucosal damage and microvascular (125)I-human serum albumin leakage (2 microCi/kg, i.v.) developed in the stomach and duodenum of male rats 24 h after the administration of cysteamine. This mucosal injury was prevented by orchidectomy and by the pretreatment with the antiandrogen, cyproterone acetate (12 mg/kg per day for 8 consecutive days). It was also shown that pretreatment with testosterone (4-20 mg/kg per week) dose-dependently aggravated cysteamine-induced gastroduodenal mucosal injury. Our results thus suggest an aggressive role of testosterone in the generation of cysteamine-induced gastroduodenal ulceration.


Assuntos
Permeabilidade Capilar/efeitos dos fármacos , Mucosa Gástrica/efeitos dos fármacos , Úlcera Péptica/fisiopatologia , Testosterona/metabolismo , Antagonistas de Androgênios/farmacologia , Animais , Acetato de Ciproterona/farmacologia , Cisteamina/toxicidade , Mucosa Gástrica/irrigação sanguínea , Masculino , Microcirculação , Orquiectomia , Úlcera Péptica/induzido quimicamente , Ratos , Ratos Wistar , Testosterona/toxicidade
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