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1.
J Intern Med ; 280(5): 518-531, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27445256

RESUMO

BACKGROUND: The long-term consequences of autoimmune diabetes in adults (AIDA) are largely unexplored. OBJECTIVE: To investigate the risk of myocardial infarction (MI) in AIDA compared to type 2 diabetes, taking into consideration the effects of socio-economic and lifestyle factors, the metabolic syndrome and glycaemic control. METHODS: A total of 62 995 participants including 207 individuals with AIDA (onset ≥35 years and anti-GAD positive) and 2322 individuals with type 2 diabetes (onset ≥35 years and anti-GAD negative), from the population-based Norwegian HUNT study, were followed for a first MI during the period 1995-2008. We identified 2614 MIs by hospital records or the National Cause of Death Registry. Cox proportional hazard models were used to estimate the risk of MI by diabetes subgroups after adjustment for age and socio-economic and lifestyle factors. RESULTS: AIDA amongst women was associated with a nearly fourfold increased risk of MI [hazard ratio (HR) 3.63, 95% confidence interval (CI) 2.21-5.96) compared to nondiabetic participants, whereas no excess risk was found in men with AIDA (HR 1.30, 95% CI 0.70-2.52). By contrast, type 2 diabetes was associated with an increased MI risk in both men (HR 1.92, 95% CI 1.62-2.26) and women (HR 2.39, 95% CI 1.98-2.89). The metabolic profile was more favourable in patients with AIDA than in those with type 2 diabetes, but glycaemic control was worse. Multivariable models and sensitivity analyses suggest that these results were robust. CONCLUSIONS: Women with AIDA were more likely to develop MI, compared to men with AIDA and both men and women with type 2 diabetes. Further investigations are warranted to confirm this gender difference.


Assuntos
Doenças Autoimunes/complicações , Diabetes Mellitus Tipo 2/complicações , Infarto do Miocárdio/complicações , Glicemia/metabolismo , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/imunologia , Feminino , Seguimentos , Humanos , Estilo de Vida , Masculino , Síndrome Metabólica/complicações , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Fatores Sexuais , Fatores Socioeconômicos
2.
Eur J Vasc Endovasc Surg ; 43(3): 308-12, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22240337

RESUMO

OBJECTIVES: Although international guidelines state that supervised exercise therapy (SET) should be offered to all patients with intermittent claudication (IC), SET appears to be underutilised in clinical practice. The aim of this study was to document current opinions of Dutch vascular surgeons on SET as treatment option for peripheral arterial occlusive disease (PAOD). MATERIALS AND METHODS: Vascular surgeons and fellows in vascular surgery were asked to complete a 24-question survey either at the 2011 Annual Meeting of the Dutch Society for Vascular Surgery or online. RESULTS: Ninety-one participants, including 83 vascular surgeons (51% of all Dutch vascular surgeons), completed the survey. The respondents would refer 75.4% of newly diagnosed patients with IC for SET. SET was considered less useful in patients with IC and major (cardiopulmonary) co-morbidity or a significant iliac artery stenosis. In critical limb ischaemia, the combination of SET and angioplasty was considered useful in 71.9%. Respondents regarded patient satisfaction (63.3%) and improvement in pain-free or maximal walking ability (26.6%) as clinically most relevant goals of SET. Most (84.4%) agreed that SET should also include lifestyle management. CONCLUSION: Although the vast majority of Dutch vascular surgeons consider SET as an important treatment option for PAOD, SET should receive more emphasis in clinical practice since arguments not to refer for SET are outdated. Furthermore, vascular surgeons agree that lifestyle management should be integrated in SET.


Assuntos
Arteriopatias Oclusivas/reabilitação , Atitude do Pessoal de Saúde , Terapia por Exercício/estatística & dados numéricos , Especialidades Cirúrgicas/estatística & dados numéricos , Atividades Cotidianas/classificação , Adulto , Angioplastia/estatística & dados numéricos , Arteriopatias Oclusivas/diagnóstico , Arteriopatias Oclusivas/terapia , Feminino , Humanos , Claudicação Intermitente/reabilitação , Masculino , Pessoa de Meia-Idade , Países Baixos/epidemiologia , Vigilância da População , Comportamento de Redução do Risco , Inquéritos e Questionários
3.
Sci Rep ; 10(1): 20416, 2020 11 24.
Artigo em Inglês | MEDLINE | ID: mdl-33235261

RESUMO

Persons with rheumatoid arthritis (RA) have increased risk of myocardial infarction (MI). Overlapping associations with MI of weighted genetic risk scores (wGRS) for coronary artery disease (CAD) and RA is unknown in a population-based setting. Data from the prospective Nord-Trøndelag Health Study (HUNT2: 1995-1997 and HUNT3: 2006-2008) were used. wGRS added each participant's carriage of all risk variants weighted by the coefficient from published association studies. Published wGRS for CAD and RA were analysed in Cox regression with MI as outcome, age as analysis time, and censoring at the first MI, death, or 31.12.2017. 2609 of 61,465 participants developed MI during follow-up (mean 17.7 years). The best-fitting wGRS for CAD and RA included 157 and 27 single-nucleotide polymorphisms, respectively. In multivariable analysis including traditional CAD risk factors, the CAD wGRS was associated with MI [hazard ratio = 1.23 (95% CI 1.18-1.27) for each SD increase, p < 0.0001] in RA patients (n = 433) and controls. The RA wGRS was not significant (p = 0.06). Independently from traditional risk factors, a CAD wGRS was significantly associated with the risk for MI in RA patients and controls, whereas an RA wGRS was not. The captured genetic risk for RA contributed little to the risk of MI.


Assuntos
Artrite Reumatoide/genética , Infarto do Miocárdio/genética , Polimorfismo de Nucleotídeo Único , Adulto , Idoso , Estudos de Casos e Controles , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Noruega , Estudos Prospectivos , Análise de Regressão
4.
Science ; 170(3956): 464-6, 1970 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-4918259

RESUMO

Dividing cells of chick embryonic fibroblasts and of mouse embryonic fibroblasts (3T3) in tissue culture are electrically coupled to their interphase neighbors. Recordings from many such cells suggest that this coupling persists throughout the division cycle of the mitotic cell.


Assuntos
Membrana Celular/fisiologia , Técnicas de Cultura , Fibroblastos/citologia , Potenciais da Membrana , Animais , Embrião de Galinha , Embrião de Mamíferos/citologia , Junções Intercelulares , Camundongos , Microscopia Eletrônica de Varredura , Microscopia de Contraste de Fase , Mitose
5.
Cancer Res ; 49(7): 1829-35, 1989 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-2924322

RESUMO

The occupational and environmental hazards of nickel exposure are of great concern in environmental medicine. Nickel workers have increased risk of cancer of the nose, lung, larynx, and possibly the kidney. In the present investigation we have studied the effects of nickel ions on fetal human kidney cortex explants. The explants were continuously exposed to 5 micrograms/ml NiSO4. After 70-100 days in culture foci of phenotypically altered cells appeared. Immortalized cell lines were established and demonstrated to be of human epithelial origin. Tumorigenicity was not induced, but the cells demonstrated decreased requirement for serum, increased plating efficiency and saturation density, and formation of colonies in soft agar. Chromosome changes in the treated cells were observed. Worth mentioning are change in ploidy (3n) and abnormalities of chromosomes 1, 7, 9, 11, 13, 14 and 20; increased numbers of chromosome 17; and loss of normal chromosomes 20 and 22.


Assuntos
Transformação Celular Neoplásica/efeitos dos fármacos , Rim/efeitos dos fármacos , Níquel/toxicidade , Carcinógenos Ambientais/toxicidade , Células Cultivadas , Aberrações Cromossômicas , Epitélio/efeitos dos fármacos , Epitélio/ultraestrutura , Humanos , Rim/ultraestrutura
6.
Open Heart ; 3(1): e000363, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26925243

RESUMO

OBJECTIVE: Symptoms of anxiety and depression often co-exist with cardiovascular disease (CVD), yet little is known about the association with left ventricular (LV) subclinical dysfunction. We aimed to study the cross-sectional associations of previous, current and repeated depression or anxiety symptoms, with sensitive indices of LV systolic and diastolic function, based on tissue Doppler (TD) and speckle tracking (ST) imaging methods. METHODS: A random selection of 1296 individuals free from known CVD, hypertension and diabetes were examined with echocardiography at baseline of the third Nord-Trøndelag Health Study, (HUNT3, 2006-2008). The primary outcomes were LV diastolic function (e') and LV systolic function (longitudinal global strain). The primary exposures were self-report on the Hospital Anxiety and Depression Scale (HADS). Associations between outcomes and baseline exposures were available for 1034 (80%), and with previous and repeated exposures for 700 participants who also participated in HUNT2 (1995-1997). RESULTS: Previous and repeated depression symptoms, but not current depression, were linearly associated with a reduction in e'. The average sum of two repeated HADS-D scores 10 years apart had the strongest effect on e' (-8.3%; 95% CI -13.9% to -2.7%) per 5 units. We observed a sex difference between depression symptoms and longitudinal global strain (p for interaction 0.019), where women had a marginal negative effect. Anxiety symptoms, neither previous, current nor repeated were associated with subclinical LV dysfunction. CONCLUSIONS: In a healthy sample, confirmed free of CVD, past and repeated depression symptoms were associated with subclinical LV dysfunction. Thus, depression symptoms might represent a modifiable risk factor for future CVD.

7.
Arterioscler Thromb Vasc Biol ; 21(7): 1124-30, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11451740

RESUMO

Although the accumulation of cholesterol and other lipidic material is unquestionably important in atherogenesis, the reasons why this material progressively accumulates, rather than being effectively cleared by phagocytic cells such as macrophages, are not completely understood. We hypothesize that atheromatous lesions may represent "death zones" that contain toxic materials such as oxysterols and in which monocytes/macrophages become dysfunctional and apoptotic. Indeed, cathepsins B and L, normally confined to the lysosomal compartment, are present in the cytoplasm and nuclei of apoptotic (caspase-3-positive) macrophages within human atheroma. The possible involvement of oxysterols is suggested by experiments in which cultured U937 and THP-1 cells exposed to 7-oxysterols similarly undergo marked lysosomal destabilization, caspase-3 activation, and apoptosis. Like macrophages within atheroma, intralysosomal cathepsins B and L are normally present in the cytoplasm and nuclei of these oxysterol-exposed cells. Lysosomal destabilization, cathepsin release, and apoptosis may be causally related, because inhibitors of cathepsins B and L suppress oxysterol-induced apoptosis. Thus, toxic materials such as 7-oxysterols in atheroma may impair the clearance of cholesterol and other lipidic material by fostering the apoptotic death of phagocytic cells, thereby contributing to further development of atherosclerotic lesions.


Assuntos
Apoptose , Arteriosclerose/patologia , Macrófagos/patologia , Artérias/enzimologia , Artérias/patologia , Arteriosclerose/enzimologia , Catepsina B/imunologia , Catepsina B/fisiologia , Catepsina L , Catepsinas/imunologia , Catepsinas/fisiologia , Linhagem Celular , Cisteína Endopeptidases , Humanos , Hidroxicolesteróis/farmacologia , Imuno-Histoquímica , Lisossomos/enzimologia , Macrófagos/enzimologia , Macrófagos/ultraestrutura , Células U937
8.
Free Radic Biol Med ; 23(4): 616-26, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9215807

RESUMO

Acridine orange (AO) is a lysosomotropic weak base, a metachromatic fluorochrome, and a photosensitizer, as well. Living cells that are exposed for a short period of time to this compound at low concentration, and under ordinary culture conditions, accumulate the drug within their acidic vacuolar compartment, giving rise to a mainly red, granular fluoresence upon excitation with blue light. When AO-loaded cells are irradiated with intense blue light, AO soon starts to leak from late endosomes and lysosomes, partially shifting the fluorescence to a green, nuclear and diffuse cytosolic, one. This AO-relocalization is a consequence of photo-oxidation of the lysosomal membranes, which initially results in disruption of their proton-gradients and later, in leakage into the cytosol of a host of hydrolytic enzymes--as was here demonstrated by immunocytochemistry--which are capable of causing cellular damage. Most fibroblasts survived minor photo-oxidation, with a period of reparative autophagocytosis. Severe photo-oxidation, which resulted in severe lysosomal damage, caused cellular necrosis; whereas moderate stress, resulting in only partial lysosomal leakiness lead to apoptosis with TUNEL-positive nuclei and shrunken cytoplasm. The findings of the present study show that photo-oxidative damage to the membranes that surround the acidic vacuolar compartment, is an event that results in release of proteolytic and DNA-fragmenting enzymes into the cytosol, which may induce either necrosis, apoptosis, or reparable sublethal damage, depending on the magnitude of lysosomal rupture. Furthermore, the results strongly suggest that proteases and endonucleases of lysosomal origin may induce apoptosis if relocalized from the acidic vacuolar compartment into the cytosol.


Assuntos
Apoptose , Fibroblastos/ultraestrutura , Membranas Intracelulares/química , Membranas Intracelulares/fisiologia , Luz , Lisossomos/ultraestrutura , Laranja de Acridina , Catepsina D/análise , Catepsina D/metabolismo , Linhagem Celular , Humanos , Masculino , Microscopia Eletrônica , Microscopia Eletrônica de Varredura , Oxirredução
9.
Free Radic Biol Med ; 19(6): 813-22, 1995 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8582654

RESUMO

The cytotoxicity of hydrogen peroxide is, at least partly, mediated by the induction of intralysosomal iron-catalyzed oxidative reactions with damage to lysosomal membranes and leakage of destructive contents. We hypothesize that minor such leakage may be nonlethal, and the ensuing cellular degeneration repairable. Consequently, we investigated, using a model system of cultured J-774 cells, the effects of hydrogen peroxide in moderate concentrations on cellular viability, lysosomal membrane integrity, morphology, and ATP and reduced glutathione concentrations. These parameters were initially estimated directly after a 30 min exposure to a bolus dose of hydrogen peroxide in phosphate buffered saline at 37 degrees C, and then again following subsequent recovery periods of different lengths under ordinary culture conditions. All cells survived an exposure to 250 microM hydrogen peroxide for 30 min, whereas 350 and 500 microM exposure was lethal to a small fraction of cells. The oxidative stress caused early, time- and dose-dependent, partial relocalization of the lysosomotropic weak base acridine orange from the lysosomal compartment to the cytosol. This phenomenon is known to parallel leakage of damaging lysosomal contents such as hydrolytic enzymes. There were also signs of cellular damage in the form of surface blebbing and increased autophagocytosis, more marked with the higher doses of hydrogen peroxide. Also found was a rapid depletion of ATP and GSH. These alterations were all reversible, as long as cells were exposed to nonlethal amounts of hydrogen peroxide. Based on these and previous findings, we suggest that lysosomes are less stable organelles than has hitherto been assumed. Restricted lysosomal leakage might be a common event, for example, during sublethal oxidative stress, causing reversible, degenerative alterations, which are repaired by autophagocytosis.


Assuntos
Peróxido de Hidrogênio/farmacologia , Lisossomos/efeitos dos fármacos , Laranja de Acridina , Trifosfato de Adenosina/metabolismo , Animais , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/ultraestrutura , Sobrevivência Celular/efeitos dos fármacos , Citoplasma/efeitos dos fármacos , Citoplasma/ultraestrutura , Radicais Livres , Glutationa/metabolismo , Peróxido de Hidrogênio/administração & dosagem , Membranas Intracelulares/efeitos dos fármacos , Membranas Intracelulares/metabolismo , Ferro/metabolismo , Linfoma Difuso de Grandes Células B , Lisossomos/ultraestrutura , Camundongos , Microscopia Eletrônica , Microscopia Eletrônica de Varredura , Oxirredução , Estresse Oxidativo , Células Tumorais Cultivadas
10.
Free Radic Biol Med ; 28(2): 208-18, 2000 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-11281288

RESUMO

We have previously shown that oxidized low-density lipoprotein (LDL) induces damage to the macrophage lysosomal membranes, with ensuing leakage of lysosomal contents and macrophage cell death. Cholesterol oxidation products (ChOx) have been reported to be the major cytotoxic components of oxidized LDL/LDL- and also to stimulate cholesterol accumulation in vascular cells. In the present study, we characterized the initial events during macrophage damage induced by cholesterol oxidation products (ChOx). Within 24 h of exposure, ChOx caused lysosomal destabilization, release to the cytosol of the lysosomal marker-enzyme cathepsin D, apoptosis, and postapoptotic necrosis. Enhanced autophagocytosis and chromatin margination was found 12 h after the exposure to ChOx, whereas apoptosis and postapoptotic necrosis was pronounced 24 and 48 h after the exposure. Some lysosomal vacuoles were then filled with degraded cellular organelles, indicating phagocytosis of apoptotic bodies by surviving cells. Because caspase-3 activation was detected in the ChOx-exposed cells, lysosomal destabilization may associate with the leakage of lysosomal enzymes, and activation of the caspase cascade. MnSOD mRNA levels were markedly increased after 24 h of exposure to ChOx, suggesting associated induction of mitochondrial protection repair or turnover. We conclude that ChOx-induced damage to lysosomes and mitochondria are sequelae to the cascade of oxysterol cytotoxic events. The early disruption of lysosomes induced by ChOx, with resultant autophagocytosis may be a critical event in apoptosis and/or necrosis of macrophages/foam cells during the development of atherosclerotic lesions.


Assuntos
Permeabilidade da Membrana Celular/efeitos dos fármacos , Colesterol/análogos & derivados , Colesterol/farmacologia , Lisossomos/ultraestrutura , Macrófagos/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Catepsina D/metabolismo , Linhagem Celular , Cromatina/efeitos dos fármacos , Cromatina/ultraestrutura , Citosol/enzimologia , Cinética , Lisossomos/efeitos dos fármacos , Macrófagos/ultraestrutura , Camundongos , Oxirredução , Superóxido Dismutase/genética , Fatores de Tempo , Transcrição Gênica/efeitos dos fármacos
11.
FEBS Lett ; 470(1): 35-9, 2000 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-10722841

RESUMO

Controlled lysosomal rupture was initiated in lysosome-rich, macrophage-like cells by the synthetic lysosomotropic detergent, O-methyl-serine dodecylamide hydrochloride (MSDH). When MSDH was applied at low concentrations, resulting in partial lysosomal rupture, activation of pro-caspase-3-like proteases and apoptosis followed after some hours. Early during apoptosis, but clearly secondary to lysosomal destabilization, the mitochondrial transmembrane potential declined. At high concentrations, MSDH caused extensive lysosomal rupture and necrosis. It is suggested that lysosomal proteases, if released to the cytosol, may cause apoptosis directly by pro-caspase activation and/or indirectly by mitochondrial attack with ensuing discharge of pro-apoptotic factors.


Assuntos
Amidas/farmacologia , Apoptose/fisiologia , Detergentes/farmacologia , Lisossomos/fisiologia , Serina/análogos & derivados , Animais , Apoptose/efeitos dos fármacos , Caspase 3 , Caspases/metabolismo , Linhagem Celular , Permeabilidade da Membrana Celular/efeitos dos fármacos , Ativação Enzimática , Humanos , Membranas Intracelulares/efeitos dos fármacos , Lisossomos/efeitos dos fármacos , Camundongos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/fisiologia , Serina/farmacologia , Células U937
12.
Antioxid Redox Signal ; 1(3): 305-15, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-11229442

RESUMO

Reactive oxygen intermediates (ROI) may be involved in the destruction of pancreatic beta-cells during the development of insulin-dependent diabetes mellitus (IDDM). To investigate the possible role of lysosomes in this process, normal mouse beta-cells were cultured as monolayers at D-glucose concentrations of 1.6 (pronounced crinophagy), 11 or 28 mM (minimal crinophagy), subjected to a low level of oxidative stress and returned to standard culture conditions. Some cultures were exposed to desferrioxamine (Des) before the oxidative stress. As a result of such stress, many of the cells' lysosomes ruptured with consequent apoptosis or necrosis. Cells kept at 1.6 mM glucose were rich in secretory granules, showed crinophagy/autophagy, were very sensitive to oxidative stress, and had the least stable lysosomes. Cells kept at 28 mM glucose did not show crinophagy, contained fewer secretory granules, were less sensitive to oxidative stress, and had more stable lysosomes. Des-treated cells behaved almost as cells not exposed to oxidative stress at all. The findings suggest that iron may occur together with zinc within the secretory granules and that it sensitizes crinophagic lysosomes to oxidative stress. The stress that was applied in this study may be comparable to what occurs within the vicinity of activated macrophages during autoimmune insulitis.


Assuntos
Apoptose , Ilhotas Pancreáticas/citologia , Lisossomos/metabolismo , Estresse Oxidativo , Animais , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Células Cultivadas , Desferroxamina/farmacologia , Glucose/administração & dosagem , Glucose/farmacologia , Histocitoquímica , Peróxido de Hidrogênio/farmacologia , Membranas Intracelulares/efeitos dos fármacos , Ilhotas Pancreáticas/efeitos dos fármacos , Ilhotas Pancreáticas/metabolismo , Ilhotas Pancreáticas/ultraestrutura , Lisossomos/efeitos dos fármacos , Lisossomos/ultraestrutura , Camundongos , Camundongos Endogâmicos , Microscopia Eletrônica , Microscopia de Fluorescência , Necrose , Estresse Oxidativo/efeitos dos fármacos , Vesículas Secretórias/efeitos dos fármacos , Vesículas Secretórias/metabolismo
13.
Atherosclerosis ; 58(1-3): 27-37, 1985 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-4091883

RESUMO

The formation of craters under in vitro hypoxic conditions in the human venous endothelium was studied by scanning-(SEM) and transmission electron microscopy (TEM). Craters are a result of collapsed intracytoplasmatic vesicles which is probably due to extraction of fluid during processing. Thus craters are thought to be artefacts of preparation. This investigation indicates that fusion of caveolae is involved in intracytoplasmatic vesicle formation. A new quantitative method is described for studying endocytosis. Whole vein wall preparations immersed in isotonic saline (approximately 1 h) revealed reduced endocytotic activity in the luminal plasma membrane (LPM) of endothelial cells compared to the basal plasma membrane (BPM), where the endocytotic activity was increased.


Assuntos
Endocitose , Veias/ultraestrutura , Membrana Celular/fisiologia , Membrana Celular/ultraestrutura , Endotélio/fisiologia , Endotélio/ultraestrutura , Humanos , Hipóxia/patologia , Hipóxia/fisiopatologia , Técnicas In Vitro , Microscopia Eletrônica , Veias/fisiologia
14.
Exp Gerontol ; 34(8): 943-57, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10673148

RESUMO

To test whether heavy accumulation of ceroid/lipofuscin can disturb important functions of the lysosomal system, AG-1518 human fibroblasts, ceroid/lipofuscin-loaded (following prolonged culture at normobaric hyperoxia) or not, were exposed to amino acid starvation. Ceroid/lipofuscin-loading resulted in decreased cellular survival. Also, there was an inverse relationship between amounts of ceroid/lipofuscin and the survival time of individual cells within the same cultures. Ceroid/lipofuscin-loaded fibroblasts displayed diminished autophagocytotic capacity, as demonstrated by electron microscopy and by treatment of cell cultures with NH4Cl (which inhibits autophagocytotic degradation by increasing intralysosomal pH) for 1 week before ensuing starvation. The latter treatment increased survival of control cells (due to deposition of nondegraded autophagocytosed material before start of starvation), but not that of ceroid/lipofuscin-loaded cells. Moreover, when NH4Cl treatment was combined with starvation, both groups of cells showed approximately the same shortened survival times, testifying to the causal relationship between diminished autophagocytosis and decreased survival of starving ceroid/lipofuscin-loaded cells. We hypothesize that large amounts of undegradable ceroid/lipofuscin within the acidic vacuolar compartment may interfere with lysosomal function, resulting in poor renewal of long-lived proteins and worn-out/damaged organelles, decreased adaptability, and cell death.


Assuntos
Aminoácidos/deficiência , Autofagia/fisiologia , Ceroide/metabolismo , Fibroblastos/fisiologia , Lipofuscina/metabolismo , Sobrevivência Celular/fisiologia , Células Cultivadas , Fibroblastos/metabolismo , Fibroblastos/ultraestrutura , Humanos , Microscopia Confocal , Microscopia Eletrônica , Valores de Referência , Fatores de Tempo
15.
J Thorac Cardiovasc Surg ; 108(3): 556-66, 1994 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8078349

RESUMO

Hypercholesterolemia is an important contributor to the development of intimal hyperplasia and superimposed accelerated atherosclerosis in vein bypass grafts. This study examines the effect of dietary modification of serum cholesterol on the development of intimal hyperplasia and vasomotor function of vein grafts. Thirty male New Zealand White rabbits had a right carotid vein bypass graft and were put to death 28 days after the operation. Twenty animals received a 1% cholesterol diet for 4 weeks before the operation. In 10 animals this diet was continued until harvest (hypercholesterolemia group). In another 10 animals the diet was changed to standard rabbit chow on the day of the surgical procedure and continued until harvest (cholesterol reduction group). The last 10 animals were control subjects. Vein grafts were harvested either for histologic study or for in vitro isometric tension studies. Cumulative dose response curves to norepinephrine, serotonin, bradykinin, and endothelin-1 were determined. After in situ pressure fixation, intimal thicknesses of the vein grafts were measured by videomorphometry. The change in diet produced a 74% reduction in serum cholesterol concentration within 28 days. There was a 26% reduction in the intimal thickness of vein graft intimal hyperplasia and the macroscopic disappearance of atheromatous lesions from the graft wall, which are always observed in vein grafts from the hypercholesterolemia group. Cholesterol reduction did not change hypercholesterolemia-induced agonist supersensitivity. Therefore, cholesterol reduction slows the formation of intimal hyperplasia in vein grafts but does not prevent the persistence of the hypercholesterolemia-associated smooth muscle phenotype.


Assuntos
Hipercolesterolemia/fisiopatologia , Músculo Liso Vascular/fisiologia , Túnica Íntima/patologia , Vasoconstrição , Veias/transplante , Animais , Colesterol/sangue , Colesterol na Dieta , Hiperplasia , Técnicas In Vitro , Masculino , Microscopia Eletrônica de Varredura , Músculo Liso Vascular/patologia , Coelhos , Túnica Íntima/fisiologia , Túnica Íntima/ultraestrutura , Vasoconstrição/efeitos dos fármacos , Vasoconstritores/farmacologia , Veias/patologia , Veias/fisiologia
16.
APMIS ; 107(8): 747-61, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10515125

RESUMO

When cultured NIT-1 cells were subjected to a low level of oxidative stress (30 microM hydrogen peroxide for 15 min at 37 degrees C) several of their lysosomes ruptured, as demonstrated by intravital staining with the lysosomotropic weak base acridine orange. Such rupture is due to intralysosomal, iron-catalyzed oxidative reactions, since it was largely prevented by previous endocytotic uptake of desferrioxamine. The resultant limited leakage of lysosomal hydrolytic enzymes into the cytosol could be important for an apoptotic-type degradation/fragmentation process within initially intact plasma membranes. In contrast, extensive lysosomal rupture leads to necrosis. The development of the damage process was followed by light- and electron microscopy; and by the TUNEL-reaction. As a result of the applied oxidative stress, which is comparable to that expected to occur within the microenvironment surrounding activated macrophages under oxidative burst (e.g. during autoimmune insulitis), about 90% of the cells eventually died due to post-apoptotic secondary necrosis. The few surviving cells phagocytosed the debris from their fragmented neighbours and began to divide about 24 h after the insult. Thus the sensitivity to oxidative stress varies, perhaps as a consequence of varying amounts of intralysosomal redox-active iron, as we have found to be the case in several other cellular systems. Since the NIT-1 cells are highly differentiated, and in many ways like beta cells, we consider our result to be of value for the understanding of beta-cell death during the development of insulin-dependent (Type I) diabetes mellitus (IDDM).


Assuntos
Apoptose , Estresse Oxidativo , Trifosfato de Adenosina/metabolismo , Caspase 3 , Caspases/metabolismo , Linhagem Celular Transformada , Estudos de Avaliação como Assunto , Humanos , Peróxido de Hidrogênio/farmacologia , Insulinoma , Líquido Intracelular/metabolismo , Membranas Intracelulares/efeitos dos fármacos , Membranas Intracelulares/fisiologia , Células Jurkat , Lisossomos/efeitos dos fármacos , Microscopia Confocal , Microscopia Eletrônica , Células Tumorais Cultivadas
17.
Surgery ; 116(3): 557-68, 1994 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8079186

RESUMO

BACKGROUND: Previous studies in animals and human beings have shown that vein bypass grafts exhibit diminished endothelium-dependent relaxation and the development of intimal hyperplasia. This study examines the effect of L-arginine on experimental vein graft endothelial cell function and the development of intimal hyperplasia. METHODS: Common carotid vein bypass grafts were performed in 24 New Zealand White rabbits: 12 were controls and 12 received L-arginine (2.25%) orally 7 days before operation and thereafter until harvest 28 days after operation. Intimal and medial dimensions were determined by planimetry on pressure-fixed vessels. Relaxation to acetylcholine, serotonin, calcium ionophore (A23187), and sodium nitroprusside was performed on precontracted vessel rings. RESULTS: Arginine-treated vein grafts showed a 47% reduction in mean intimal thickness (p < 0.001) compared with controls. By scanning and transmission electron microscopy, all vein grafts showed a confluent endothelium. In contrast to control grafts, which do not relax to acetylcholine and serotonin, arginine-treated vein grafts relaxed in response to both agonists. There was a significant increase (p < 0.05) in the maximal relaxation to calcium ionophore (A23187) in arginine-treated vein grafts compared with control grafts. Non-endothelium-dependent responses to sodium nitroprusside were equivalent in all vein grafts. CONCLUSIONS: This study shows that oral L-arginine supplementation significantly reduces intimal hyperplasia and preserves nitric oxide-mediated relaxation in experimental vein grafts, suggesting a role for nitric oxide in the regulation of the cellular events that lead to intimal hyperplasia.


Assuntos
Arginina/uso terapêutico , Oclusão de Enxerto Vascular/prevenção & controle , Veias Jugulares/transplante , Túnica Íntima/patologia , Animais , Arginina/farmacologia , Artéria Carótida Primitiva/cirurgia , Relação Dose-Resposta a Droga , Oclusão de Enxerto Vascular/fisiopatologia , Hiperplasia/tratamento farmacológico , Veias Jugulares/efeitos dos fármacos , Veias Jugulares/fisiologia , Óxido Nítrico , Coelhos , Túnica Íntima/efeitos dos fármacos , Túnica Íntima/fisiologia , Vasoconstrição/efeitos dos fármacos , Vasodilatação/efeitos dos fármacos
18.
Surgery ; 114(2): 258-70; discussion 270-1, 1993 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8342130

RESUMO

BACKGROUND: The reversibility of the morphologic and functional alterations that occur in veins transplanted into the arterial circulation was examined in this study. METHODS: Common carotid vein bypass grafts (VG) were performed in 20 male New Zealand White rabbits. Ten VG and jugular veins (CV) were harvested after 14 days, and ten VG were reimplanted as venovenous bypass grafts (REV) and harvested after an additional 14 days. Vessels were taken for structural or isometric tension studies to norepinephrine, serotonin, and bradykinin and to acetylcholine and sodium nitroprusside after precontraction. RESULTS: There was a decrease in the thickness of the intima (p = 0.02) and the media (p = 0.002) in REV compared with VG. In REV, sensitivity to norepinephrine decreased (p = 0.0007) with a reduced maximal tension to norepinephrine (p = 0.02) and to serotonin (p = 0.0001). Bradykinin sensitivity increased in REV (p = 0.003 vs VG) and was greater than in CV. Only the precontracted CV and REV relaxed to acetylcholine. All tissues relaxed to sodium nitroprusside. CONCLUSIONS: This study suggests that intimal hyperplasia can be reversed with restoration of endothelium-dependent relaxing factor-mediated relaxation but that only a partial regression of the contractile abnormalities can be achieved.


Assuntos
Óxido Nítrico/fisiologia , Vasodilatação , Veias/transplante , Animais , Bradicinina/farmacologia , Endotélio Vascular/patologia , Endotélio Vascular/ultraestrutura , Histamina/farmacologia , Hiperplasia , Técnicas In Vitro , Masculino , Norepinefrina/farmacologia , Coelhos , Serotonina/farmacologia , Vasodilatação/efeitos dos fármacos , Veias/patologia
19.
J Hosp Infect ; 41(2): 123-32, 1999 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10063474

RESUMO

In Norway, infections caused by methicillin resistant Staphylococcus aureus (MRSA) are still uncommon. From December 1993 to January 1997, MRSA was isolated from 22 people in Oslo county; 17 patients and five carriers (healthcare workers). A cluster of ten people (five patients and five healthcare workers) were associated with an outbreak at two hospitals in Oslo. The five patients were all admitted to the same intensive care unit (ICU) at Ullevål University Hospital between May-July 1995 (they were not transferred from abroad) and treated for acute neurological lesions. After surgery, four of them (one died) were transferred to another hospital for rehabilitation and training. The presence of MRSA was discovered in the patients and the five healthcare workers during the 10 months June 1995-March 1996. All cluster strains showed an unusual antibiotic resistance pattern in vitro, with a relatively low degree of methicillin resistance, resistance to fusidic acid, but sensitivity to all other anti-staphylococcal agents. A clonal spread of this fusidic acid resistant MRSA was supported by strain typing using pulsed-field gel electrophoresis (PFGE), which showed that all ten cluster strains belonged to one type or its subtype.


Assuntos
Antibacterianos , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/microbiologia , Surtos de Doenças/estatística & dados numéricos , Ácido Fusídico , Resistência a Meticilina , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus , Adolescente , Adulto , Idoso , Análise por Conglomerados , Infecção Hospitalar/tratamento farmacológico , Eletroforese em Gel de Campo Pulsado , Feminino , Humanos , Lactente , Controle de Infecções , Unidades de Terapia Intensiva , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Noruega/epidemiologia , Transferência de Pacientes , Centros de Reabilitação , Sorotipagem , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/classificação , Staphylococcus aureus/genética
20.
J Epidemiol Community Health ; 48(3): 248-53, 1994 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8051522

RESUMO

STUDY OBJECTIVE: To elicit lay concepts of health and to see whether these are related to various sociodemographic factors, as has been suggested by previous smaller studies. DESIGN AND SETTING: A total of 196 people aged 18 and over were selected, as a representative sample of the general population, from the electoral registers of Walsall and Dudley in the West Midlands. Respondents were interviewed in their own homes in the autumn of 1989. MEASUREMENTS: Open ended and structured questions were used to elicit concepts of health. The three main stages consisted of an unprompted section in which respondents were asked to describe the features of good or poor health in themselves or others; a prompted section in which they were asked to rate 37 health statements using a series of categories from "very important" to "not at all important"; and a section in which they were asked to indicate which of six groups of statements, each representing a particular concept of health, best represented their own notions of health. RESULTS: Health was seen as multidimensional. Irrespective of whether respondents addressed health in self or health in others, or good or poor health, the biomedical dimension remained an important one. The manner by which concepts of health are elicited may provide some explanation as to why so many and varied concepts are alleged to be held by different subgroups of the population (notably different social classes). CONCLUSIONS: The differences found in this study between models of health employed by different subgroups of the general population have not been as great as has previously been suggested in the published reports. This is encouraging for those using existing health status measurements.


Assuntos
Atitude Frente a Saúde , Indicadores Básicos de Saúde , Classe Social , Adolescente , Adulto , Fatores Etários , Idoso , Doença/psicologia , Escolaridade , Inglaterra , Feminino , Humanos , Renda , Masculino , Estado Civil , Saúde Mental , Pessoa de Meia-Idade , Ocupações , Aptidão Física , Fatores Sexuais
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