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1.
Cult Med Psychiatry ; 48(2): 384-400, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38652343

RESUMO

Neurodegenerative diseases (ND) pose significant challenges for biomedicine in the twenty-first century, particularly considering the global demographic ageing and the subsequent increase in their prevalence. Characterized as progressive, chronic and debilitating, they often result in higher mortality rates compared with the general population. Research agendas and biomedical technologies are shaped by power relations, ultimately affecting patient wellbeing and care. Drawing on the concepts of bio- and necropolitics, introduced by philosophers Foucault and Mbembe, respectively, this perspective examines the interplay between the territoriality and governmentality around demographic ageing, ND and death, focussing on knowledge production as a dispositif of power by highlighting the marginal role that the phenomenon of mortality plays in the ND research landscape. We propose a shift into acknowledging the coloniality of knowledge and embracing its situatedness to attain knowledge 'from death', understood as an epistemic position from which novel approaches and practices could emerge.


Assuntos
Doenças Neurodegenerativas , Humanos , Doenças Neurodegenerativas/mortalidade
2.
Rev Esp Quimioter ; 30(3): 213-223, 2017 Jun.
Artigo em Espanhol | MEDLINE | ID: mdl-28537063

RESUMO

OBJECTIVE: Invasive fungal disease (IFD) is an important cause of morbidity and mortality in haematological patients. Antifungal prophylaxis (AFP) is indicated for a number of clinical scenarios in this group of patients. The aim of this study was to reach a consensus on IFD prophylaxis in haematological patients in order to optimize their management. METHODS: A committee of experts in haematology and infectious diseases compiled a survey of 79 items with controversial aspects about antifungal prophylaxis in haematological patients. The survey was evaluated in two rounds by a panel of experts following a modified Delphi methodology. RESULTS: Forty-four experts in haematology and infectious diseases answered the survey. After two evaluation rounds, consensus was reached in 67 of the 79 items (84.8%), specifically 48 items were consensually agreed on (60.7%) and 19 were disagreed on (24.0%). Consensus was reached on prophylaxis candidates profiles and questions related to indications, mechanisms of action, spectrum of activity, toxicity and interactions of antifungal were elucidated. The usefulness of micafungin in IFD prophylaxis was particularly analysed. The consensus reached was that micafungin is an antifungal to be considered in this context as its safety profile and lower interaction potential may be advantageous. CONCLUSIONS: A broad consensus was found in the management of IFD prophylaxis in the haematological patient. This consensus provides practical indications about its optimal management and can help determine the profile of patients eligible for this type of intervention.


Assuntos
Antifúngicos/uso terapêutico , Doenças Hematológicas/complicações , Infecções Fúngicas Invasivas/prevenção & controle , Antifúngicos/efeitos adversos , Consenso , Técnica Delphi , Equinocandinas/uso terapêutico , Pesquisas sobre Atenção à Saúde , Neoplasias Hematológicas , Humanos , Hospedeiro Imunocomprometido , Lipopeptídeos/uso terapêutico , Micafungina
3.
Ann Ig ; 15(1): 83-91, 2003.
Artigo em Italiano | MEDLINE | ID: mdl-12666327

RESUMO

The aim of this study is to analyse the condition of the elderly of Rome through a multidimensional instrument to determine their assistance needs. To this purpose a sample composed by 693 over 65 subjects was selected (430 women and 263 men). The Geriatric Functional Rating Scale of Grauer was administered to them. The questionnaire is divided into 7 sections (physical health, mental health, functional skills, support to the collectivity, type of housing, social relationships and economic situation); they enable to evaluate the dependency level of each subject. On the base of each area score a total score is obtained which divides the elderly into three categories according to their assistance need. The whole information collected in the single areas led to a definition of non self-sufficiency for 4.9% of the interviewed people and of partial self-sufficiency for 5.3%, the rest of the sample turned out composed by subjects able to live in an autonomous way. This sample of elderly (about 10%) is that on which it is possible to intervene with social and/or health home care plans in order to limit institutionalization.


Assuntos
Idoso , Avaliação Geriátrica , Atividades Cotidianas , Idoso de 80 Anos ou mais , Interpretação Estatística de Dados , Dependência Psicológica , Feminino , Necessidades e Demandas de Serviços de Saúde , Humanos , Entrevistas como Assunto , Masculino , Cidade de Roma , Apoio Social
4.
Environ Pollut ; 116(2): 203-14, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-11806448

RESUMO

A previous investigation on fish-farm biodeposition effects on benthos, carried out in the Gaeta Gulf (northwestern Mediterranean Sea), revealed a strong impact on meiofaunal assemblages. This study implements these findings by examining in detail the nematode assemblage and its response to organic enrichment from the start of a fish farm activity to the conclusion of the fish rearing cycle. Density, community structure and individual size were utilised for univariate (genus, trophic diversity and abundance patterns) and multivariate analyses (MDS) in order to identify the best descriptors of impact and the response of the nematode assemblages. Nematodes displayed significantly reduced densities, diversity and richness in sediments beneath fish farms. The impact of biodeposition was evident not only from structural community parameters but also in terms of functional indices. Forty-five days after starting fish farming, an increase of the nematode individual biomass was observed. MDS ordination pointed out the presence of two different nematode communities in disturbed sediments and in the control site. These results were substantiated by the analysis of the temporal changes of k-dominance curves, the maturity index and, to a lesser extent, by the index of trophic diversity. Some nematode genera were highly sensitive to biodeposition (Setosabatieria, Latronema and Elzalia) and disappeared almost completely in farm sediments, whereas other genera largely increased their dominance (Sabatieria, Dorylaimopsis and Oxystomina). This study indicates that nematodes are very sensitive to this kind of environmental disturbance. The use of simple tools, such as the k-dominance analysis and maturity index, are recommended for monitoring of aquaculture impact.


Assuntos
Aquicultura , Nematoides , Poluentes da Água/efeitos adversos , Animais , Biomassa , Peixes , Sedimentos Geológicos , Compostos Orgânicos , Dinâmica Populacional
5.
Mar Environ Res ; 52(4): 301-21, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11695652

RESUMO

Field studies were carried out to determine and compare the impact of organic loads due to the biodeposition of a mussel farm on the water quality and sediment in a coastal area of the Tyrrhenian Sea (Western Mediterranean). A total of five environmental and five microbial parameters were examined from March, 1997 to February, 1998 on a monthly basis at three stations: the first was located under the mussel farm, the second located at about 40 m away from the mussel farm, while the third designed as a control was at about 1-km. No clear changes in the physical characteristics of the water masses were observed, comparing the three sampling sites and the water column generally showed homogeneous conditions (in terms of temperature and salinity). Changes in density of aerobic heterotrophic bacteria, Escherichia coli and Enterococci in the water column are apparently independent from changes in environmental parameters. At all stations a constant significant correlation between temperature and presumptive Vibrio parahaemolyticus was reported suggesting that this abiotic factor exerted a major control on this bacterial group and its distribution in the water column is not related to the biodeposition of the mussel farm. The major impact identified was on the sediment where variations in bacterial abundance was observed. In the Mussel station sediment enrichment of organic compounds, and the consequent modification of the characteristics of the benthic environment, determined an increase in aerobic heterotrophic bacteria, and particularly of vibrios density (on average about 60%), suggesting that these bacteria are good indicators of organic enrichment.


Assuntos
Aquicultura , Bactérias , Bivalves , Microbiologia da Água , Poluentes da Água/análise , Animais , Monitoramento Ambiental/métodos , Sedimentos Geológicos , Compostos Orgânicos , Dinâmica Populacional
6.
Res Q Exerc Sport ; 72(2): 117-24, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11393874

RESUMO

The purpose of this study was to examine the psychometric properties of child- and teacher-reported curl-up (CU) scores in children ages 10-12 years in both a norm-referenced (NR) and criterion-referenced (CR) framework. Eighty-four children, 36 boys and 48 girls, performed the FITNESSGRAM (Cooper Institute for Aerobics Research, 1992) CU test on 2 days separated by 48-72 hr. Two video cameras were used to record students' CU performances. Two students performed the CU at the same time, with each child's performance recorded by one camera. The test was terminated when the child stopped due to fatigue or after two form errors occurred. Teacher-reported scores were the average of two independent ratings of each video performance, while child-reported scores came from data collected and recorded by the children. Single trial norm-referenced reliability was R = .75 for girls and R = .80 for boys for teacher-reported CU and R = .69 and R = .70 for child-reported CU for girls and boys, respectively. CR reliability was examined using P, proportion of students who consistently passed or failed the test across 2 days, and km, defined as reliability with chance removed. For teacher-reported scores, P = .89 and km = .78 for boys and P = .81 and km = .62 for girls. For child-reported scores, P = .86 and km = .72 for boys, while P = .79 and km = .58 for girls. For teacher-reported data, 39% of boys passed and 50% failed the test on both days, while for girls the percentages were 27% pass and 54% fail. For child-reported data, 64% of boys passed and 22% failed on both days, while 54% of girls passed and 25% failed. NR validity was examined by correlating teacher and child-reported scores. The resultant coefficient was r = .42 (95% CI = .11-.66) for boys and r = .67 (95% CI = .58-.74) for girls. Additionally, child-reported scores were significantly higher than teacher-reported scores. CR validity was examined with a contingency coefficient, and results indicated C = .55 with 44% false master errors for boys and C = .65 with 29% false master errors for girls. The findings of this study suggest that while NR reliability estimates were moderate for teacher-reported scores, single trial estimates suggest that child-reported CU should be viewed with caution. In regard to CR reliability, both teacher-reported and child-reported reliability were moderate. However, there were marked differences between teacher- and child-reported scores, with children reporting higher percentages of students passing and lower percentage of student failing the test when compared with scores reported by teachers. Validity was rather moderate when viewed in either a NR and CR framework. It is suggested that problems with child-reported scores may be due to the need for additional practice or simplification of the testing protocol.


Assuntos
Aptidão Física , Análise de Variância , Criança , Teste de Esforço , Feminino , Humanos , Masculino , Psicometria , Padrões de Referência , Reprodutibilidade dos Testes
7.
Environ Pollut ; 112(3): 427-34, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11291449

RESUMO

Bacterial and meiofaunal abundance and biomass and their response to the disturbance induced by fish-farm biodeposition were investigated from March to October 1997 on a monthly basis at two stations of the Gaeta Gulf (Tyrrhenian Sea, Mediterranean Sea). The biopolymeric fraction of the organic matter was characterized by high concentrations which was similar at both fish-farming-impacted and control stations. Similarly, bacteria accounted for a small fraction of the biopolymeric organic carbon (< 1%), while the contribution due to auto-fluorescent cell biomass (i.e. prokaryotic and eukaryotic cells displaying auto-fluorescence) to the total biopolymeric carbon was quantitatively negligible (< 0.1%). Benthic bacteria appear to be sensitive to organic enrichment as their abundance increased significantly beneath the cage, whilst numbers of meiofauna was lower than in the control. Changes occurred also in terms of individual nematode biomass that increased as result of the biodeposition. A particularly useful tool appeared to be represented by the ratio of benthic auto-fluorescent cells to bacterial abundance, bacteria to meiofaunal biomass and auto-fluorescent cells to meiofauna biomass. All these parameters described well the impact due to biodeposition on the benthic environment as their ratios displayed significantly higher values in farm sediments, but recovered rapidly (15 days) to values observed in the control (i.e. undisturbed conditions) immediately after cage removal. Changes observed in the present study highlight that the increased organic loading determined a shift of the relative contribution of the different benthic components to the total biopolymeric carbon, so that in highly impacted systems total benthic biomass becomes increasingly dominated by microbial components.


Assuntos
Aquicultura , Biomassa , Cianobactérias/crescimento & desenvolvimento , Sedimentos Geológicos/microbiologia , Nematoides/crescimento & desenvolvimento , Animais , Clorofila/análise , Clorofila A , Contagem de Colônia Microbiana , Cianobactérias/isolamento & purificação , Sedimentos Geológicos/parasitologia , Itália , Nematoides/isolamento & purificação , Pigmentos Biológicos/análise
8.
Hepatology ; 26(1): 9-21, 1997 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9214446

RESUMO

We evaluated cytotoxic effects of different unconjugated and glycine- and taurine-conjugated bile salts (BS) against bile duct epithelial cells in isolated bile ductule fragments and isolated perfused rat liver. Ultrastructural morphometric studies were performed in polarized rat bile ductule fragments exposed in vitro to increasing concentrations (10-100 micromol/L) of lithocholate (LCA), deoxycholate (DCA), chenodeoxycholate (CDCA), cholate (CA), ursodeoxycholate (UDCA), their taurine-conjugates, and glycoconjugates of cholic (GCA) or chenodeoxycholic acid (GCDCA) for 20, 30, or 75 minutes. To evaluate the cytotoxicity of unconjugated hydrophobic bile salts against biliary epithelium (BDE) in the whole liver, livers were isolated from rats with impaired taurine-conjugation capacity (beta-alanine treatment) and perfused for 70 minutes with 2 micromol/min LCA (n = 6), CDCA (n = 6), CA (n = 6), or 0.5 micromol/min tauro-LCA (n = 4). In isolated bile ductule fragments, hydrophobic unconjugated bile salts (LCA, CDCA, DCA) induced a marked damage of intracellular organelles, mainly mitochondria. The damage started at a concentration of 10 micromol/L and became prominent at concentrations higher than 50 micromol/L. No damage of the apical and basolateral membrane was seen and tight junctions appeared intact. UDCA, taurine and glycoconjugated bile salts failed to induce any evident ultrastructural alteration. In taurine-depleted isolated livers, perfused with LCA, CDCA, or CA, bile duct epithelial cells showed no evidence of intracellular damage, despite the increased biliary excretion of unconjugated BS. Marked alterations of the apical cell membrane were seen only in livers perfused with LCA and in isolated segments of the biliary epithelium. In contrast with biliary epithelium, hepatocytes showed prominent subcellular damage with CA and CDCA, and profound alterations of the canalicular membrane with LCA and tauro-LCA. We have shown that, in vitro, BDE cells are not damaged by taurine- or glycine-conjugated BS, but they are very sensitive to cytotoxicity of hydrophobic unconjugated BS. Such sensitivity is not present in the whole liver, probably because of the specificity of BS transport processes, the microvascular architecture of the bile ductal system, and the presence in bile of a physiological surfactant, such as phospholipids.


Assuntos
Ácidos e Sais Biliares/toxicidade , Ductos Biliares/efeitos dos fármacos , Fígado/efeitos dos fármacos , Animais , Aspartato Aminotransferases/metabolismo , Bile/metabolismo , Ácidos e Sais Biliares/química , Ácidos e Sais Biliares/metabolismo , Ductos Biliares/patologia , Ductos Biliares/ultraestrutura , Membrana Celular/ultraestrutura , Ácido Quenodesoxicólico/farmacologia , Ácido Cólico , Ácidos Cólicos/farmacologia , Ácido Desoxicólico/farmacologia , Epitélio/efeitos dos fármacos , Epitélio/patologia , Epitélio/ultraestrutura , Complexo de Golgi/ultraestrutura , Técnicas In Vitro , L-Lactato Desidrogenase/metabolismo , Ácido Litocólico/farmacologia , Fígado/patologia , Fígado/ultraestrutura , Microscopia Eletrônica , Mitocôndrias/ultraestrutura , Consumo de Oxigênio , Ratos , Ratos Sprague-Dawley , Taurina/fisiologia , Ácido Ursodesoxicólico/farmacologia
9.
J Clin Invest ; 96(2): 665-75, 1995 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-7635959

RESUMO

To elucidate mechanisms of glucagon-induced bicarbonate-rich choleresis, we investigated the effect of glucagon on ion transport processes involved in the regulation of intracellular pH (pHi) in isolated rat hepatocyte couplets. It was found that glucagon (200 nM), without influencing resting pHi, significantly stimulates the Cl-/HCO3- exchange activity. The effect of glucagon was associated with a sevenfold increase in cAMP levels in rat hepatocytes. The activity of the Cl-/HCO3- exchanger was also stimulated by DBcAMP + forskolin. The effect of glucagon on the Cl-/HCO3- exchange was individually blocked by two specific and selective inhibitors of protein kinase A, Rp-cAMPs (10 microM) and H-89 (30 microM), the latter having no influence on the glucagon-induced cAMP accumulation in isolated rat hepatocytes. The Cl- channel blocker, NPPB (10 microM), showed no effect on either the basal or the glucagon-stimulated Cl-/HCO3 exchange. In contrast, the protein kinase C agonist, PMA (10 microM), completely blocked the glucagon stimulation of the Cl-/HCO3- exchange; however, this effect was achieved through a significant inhibition of the glucagon-stimulated cAMP accumulation in rat hepatocytes. Colchicine pretreatment inhibited the basal as well as the glucagon-stimulated Cl-/HCO3- exchange activity. The Na+/H+ exchanger was unaffected by glucagon either at basal pHi or at acid pHi values. In contrast, glucagon, at basal pHi, stimulated the Na(+)-HCO3- symport. The main findings of this study indicate that glucagon, through the cAMP-dependent protein kinase A pathway, stimulates the activity of the Cl-/HCO3- exchanger in isolated rat hepatocyte couplets, a mechanism which could account for the in vivo induced bicarbonate-rich choleresis.


Assuntos
Antiporters/efeitos dos fármacos , Bile/metabolismo , Colagogos e Coleréticos/farmacologia , Glucagon/farmacologia , Fígado/efeitos dos fármacos , Trocadores de Sódio-Hidrogênio/efeitos dos fármacos , Sulfonamidas , Animais , Bicarbonatos/metabolismo , Bucladesina/farmacologia , Células Cultivadas , Antiportadores de Cloreto-Bicarbonato , Cloretos/metabolismo , Colchicina/farmacologia , Colforsina/farmacologia , AMP Cíclico/análogos & derivados , AMP Cíclico/farmacologia , Proteínas Quinases Dependentes de AMP Cíclico/antagonistas & inibidores , Proteínas Quinases Dependentes de AMP Cíclico/fisiologia , Concentração de Íons de Hidrogênio , Líquido Intracelular/efeitos dos fármacos , Isoquinolinas/farmacologia , Masculino , Nitrobenzoatos/farmacologia , Ratos , Ratos Wistar , Sódio/metabolismo , Acetato de Tetradecanoilforbol/farmacologia , Tionucleotídeos/farmacologia
10.
Dig Dis Sci ; 40(7): 1592-600, 1995 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7628290

RESUMO

We investigated whether S-adenosyl-L-methionine (SAMe) influences the inhibitory effect of ethanol on bile secretion and ethanol hepatotoxicity in the isolated perfused rat liver. SAMe (25 mg/kg intramuscularly three times a day) was administered for three days consecutively. Liver was then isolated and perfused with taurocholate to stabilize bile secretion and exposed to 1% ethanol for 70 min. The effect of ethanol on bile flow, bile salt biliary secretion, oxygen liver consumption, AST and LDH release in the perfusate, and hepatic concentration of glutathione, malondialdehyde, and diene conjugates was compared between SAMe-treated livers (N = 11) and paired controls (N = 11). Control experiments without ethanol were also performed (N = 6). Exposure to 1% ethanol induced a significantly (P < 0.03) higher inhibition of bile flow (-35% vs 17%) and bile salt secretion (-28% vs 16%) in untreated compared with SAMe-treated livers. During 1% ethanol exposure, the release of LDH and AST in the perfusate was significantly lower (P < 0.02) in SAMe-treated livers. Oxygen liver consumption was markedly inhibited by 1% ethanol administration (P < 0.02 vs controls without ethanol), an effect almost totally prevented by SAMe treatment (P < 0.02 vs ethanol controls). The hepatic concentration of total glutathione was significantly (P < 0.02) decreased by 1% ethanol exposure, but this effect was less pronounced in SAMe-treated than in untreated controls (P < 0.02). The hepatic levels of malondialdehyde and diene conjugates were not significantly changed by ethanol exposure in either SAMe-treated or control livers in comparison to ethanol-free controls.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Colestase/induzido quimicamente , Colestase/prevenção & controle , Etanol/antagonistas & inibidores , Hepatopatias Alcoólicas/prevenção & controle , S-Adenosilmetionina/farmacologia , Animais , Bile/efeitos dos fármacos , Bile/fisiologia , Ácidos e Sais Biliares/metabolismo , Etanol/toxicidade , Glutationa/metabolismo , Injeções Intramusculares , L-Lactato Desidrogenase/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Malondialdeído/metabolismo , Consumo de Oxigênio/efeitos dos fármacos , Perfusão , Ratos , Ratos Wistar , S-Adenosilmetionina/administração & dosagem
11.
Ital J Gastroenterol ; 27(6): 335-9, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-8563001

RESUMO

The influence of the hydrophobic-hydrophilic properties of bile salts (BS) on acute ethanol hepatotoxicity was investigated. Bile flow, biliary BS secretion and enzyme (LDH,AST) release in the perfusate were measured before and after exposure to low (0.1%) or high (1%) doses of ethanol in in vitro isolated livers perfused with 1 microM/min taurocholate (TCA), tauroursodeoxycholate (TUDCA) or taurodeoxycholate (TDCA). Ethanol promotes a rapid decrease of basal bile flow and BS secretion in TCA-perfused livers [-28% of basal values with 0.1% (N = 6), and -35% with 1% ethanol (N = 6)]. Bile flow and BS secretion were minimally decreased by ethanol in livers perfused with a hydrophilic BS (TUDCA) [-8% decrease of basal values with 0.1% ethanol (N = 6), and -10% with 1% ethanol (N = 9); p < 0.02 vs TCA-perfused livers]. In contrast, when livers were perfused with a hydrophobic BS (TDCA), ethanol showed a higher cholestatic effect than either TCA- or TUDCA-perfused livers. Enzyme release in the perfusate was not modified by 0.1% ethanol, while 1% ethanol promoted a 4-5 fold increase in LDH and AST release in the perfusate of TCA-perfused livers with respect to a mere 2-fold increase in TUDCA-perfused livers and a 6-7 fold increase in TDCA perfused livers (p < 0.03). In conclusion, we showed that TUDCA almost completely counteracts the cholestatic and cytolitic effects promoted by ethanol in the isolated perfused rat liver.


Assuntos
Bile/fisiologia , Etanol/toxicidade , Fígado/efeitos dos fármacos , Ácido Tauroquenodesoxicólico/fisiologia , Ácido Taurocólico/fisiologia , Ácido Taurodesoxicólico/fisiologia , Animais , Fígado/fisiologia , Masculino , Perfusão , Ratos , Ratos Wistar
12.
Hepatology ; 21(4): 1120-9, 1995 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7705787

RESUMO

We investigated whether bile salts (BS) with different hydrophobic-hydrophilic properties interact with ethanol on bile secretion, enzyme (aspartate transaminase [AST], lactate dehydrogenase [LDH]) release in the perfusate, liver ultrastructure, and vesicular exocytosis in the isolated perfused rat liver. Ethanol (0.1 or 1%) promoted a rapid decrease of bile flow and BS secretion in livers perfused with taurocholate (TCA), the physiologic BS in the rat (-28% decrease of baseline values with 0.1% and -34% with 1% ethanol). The inhibitory effect of ethanol on bile flow and BS secretion was significantly (P < .02) attenuated by perfusing liver with the hydrophilic BS, tauroursodeoxycholate (TUDCA), and it was exacerbated (P < .02) by perfusion with the hydrophobic BS, taurodeoxycholate (TDCA). The release of AST and LDH in the perfusate was unaffected by 0.1% ethanol, but increased threefold to fivefold by 1% ethanol in TCA-perfused livers. This cytolitic effect of ethanol was not observed in TUDCA-perfused livers, but it was enhanced (P < .03) by perfusion with TDCA. No ultrastructural abnormalities were found in either TCA- or TUDCA-perfused livers, with or without 1% ethanol. Only minimal changes were found in livers perfused with TDCA alone, but, in the presence of TDCA, 1% ethanol induces marked mitochondrial damage. The biliary excretion of the fluid phase marker horseradish peroxidase was inhibited by ethanol, an effect reversed by TUDCA (P < .02) and exacerbated by TDCA (P < .04). In conclusion, this study demonstrates that hydrophilic BS such as TUDCA counteract the inhibitory effect of ethanol on bile secretion and vesicular exocytosis as well as the ethanol-induced cytolitic effect in the isolated perfused rat liver. In the presence of hydrophobic BS such as TDCA, the exposure to ethanol promotes a marked inhibition of bile secretion and vesicular exocytosis as well as prominent mitochondrial damage.


Assuntos
Ácidos e Sais Biliares/farmacologia , Etanol/toxicidade , Fígado/efeitos dos fármacos , Animais , Aspartato Aminotransferases/metabolismo , Bile/efeitos dos fármacos , Bile/metabolismo , Ácidos e Sais Biliares/metabolismo , L-Lactato Desidrogenase/metabolismo , Fígado/fisiologia , Fígado/ultraestrutura , Masculino , Perfusão , Ratos , Ratos Wistar , Ácido Tauroquenodesoxicólico/farmacologia , Ácido Taurocólico/farmacologia , Ácido Taurodesoxicólico/farmacologia
13.
Hepatology ; 21(2): 450-9, 1995 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-7843720

RESUMO

This study investigated the effect of Brefeldin A (BFA) on the transcytotic vesicular pathway labeled with horseradish peroxidase (HRP) in both isolated rat hepatocyte couplets (IRHC) and the isolated perfused rat liver (IPRL). To evaluate the role of the transcytotic vesicular pathway on bile secretion, the effect of BFA on bile secretion in the IPRL was then investigated. In the basolateral area of IRHC, BFA showed no effect on the density and percentage of area of HRP-labeled vesicles. However, HRP-labeled vesicles tended to accumulate in the juxtanuclear area of BFA-treated hepatocytes (P < .001 vs. controls). In the pericanalicular area, on the other hand, HRP-labeled vesicles were depleted compared with controls (P < .001). In keeping with these findings, although the early peak remained unchanged, BFA inhibited as much as 50% of the late peak of HRP excretion in bile, after a pulse load of HRP in the IPRL. Bile flow and the biliary secretion of bile salts (BS) and phospholipids were not modified by BFA in isolated livers perfused without BS in the perfusate or with 1 mumol/min taurocholate (TCA). In BFA-treated livers, peak bile flow and BS output decreased by 20% (P < .05 vs. controls) only when a 5 mumol TCA bolus was administered. In conclusion, this study demonstrates that BFA inhibits the transcytotic vesicular pathway in the liver. However, BFA has no significant effect on bile secretion either in basal conditions or during perfusion with physiological amounts of BS. BFA slightly decreases bile flow and BS output only after an overload of BS, providing evidence against the physiological relevance of the transcytotic vesicular pathway in the process of bile formation.


Assuntos
Bile/metabolismo , Ciclopentanos/farmacologia , Junções Intercelulares/efeitos dos fármacos , Junções Intercelulares/fisiologia , Fígado/efeitos dos fármacos , Fígado/fisiologia , Inibidores da Síntese de Proteínas/farmacologia , Animais , Bile/efeitos dos fármacos , Bile/fisiologia , Transporte Biológico Ativo/efeitos dos fármacos , Brefeldina A , Células Cultivadas , Peroxidase do Rábano Silvestre/metabolismo , Técnicas In Vitro , Fígado/citologia , Fígado/ultraestrutura , Masculino , Microscopia Eletrônica , Ratos , Ratos Sprague-Dawley , Ácido Taurocólico/farmacologia
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