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1.
Scand J Rheumatol ; 49(4): 301-311, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32286129

RESUMO

OBJECTIVE: The complement cascade, especially the alternative pathway of complement, has been shown in basic research to be associated with anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV). We aimed to elucidate relationships between serum complement components and clinical characteristics in AAV. METHOD: In a nationwide prospective cohort study (RemIT-JAV-RPGN), we measured the serum levels of C1q, C2, C3, C3b/iC3b, C4, C4b, C5, C5a, C9, factor B, factor D, factor H, factor I, mannose-binding lectin, and properdin in 52 patients with microscopic polyangiitis (MPA) and 39 patients with granulomatosis with polyangiitis (GPA). RESULTS: The properdin level of MPA and GPA was significantly lower than that of healthy donors. The properdin level was negatively correlated with the Birmingham Vasculitis Activity Score (BVAS) (ρ = -0.2148, p = 0.0409). The factor D level at 6 months was significantly positively correlated with the Vasculitis Damage Index (VDI) at 6, 12, and 24 months (ρ = 0.4207, 0.4132, and 0.3115, respectively). Patients with a higher ratio of C5a to C5 had higher neutrophil percentage and serum immunoglobulin G levels, and significantly lower creatinine levels. Cluster analysis divided the MPA and GPA patients into three subgroups. A principal component (PC) analysis aggregated 15 types of complements into alternative pathway-related PC 1 and complement classical pathway and common pathway-related PC 2. CONCLUSIONS: The serum levels of properdin and factor D were correlated with the BVAS and the VDI in MPA and GPA, respectively. Our analyses suggested the pathological heterogeneity of MPA and GPA from the aspect of complement components.


Assuntos
Proteínas do Sistema Complemento/metabolismo , Granulomatose com Poliangiite/sangue , Poliangiite Microscópica/sangue , Idoso , Proteína C-Reativa/metabolismo , Estudos de Casos e Controles , Análise por Conglomerados , Feminino , Granulomatose com Poliangiite/tratamento farmacológico , Granulomatose com Poliangiite/etiologia , Humanos , Imunossupressores/uso terapêutico , Masculino , Poliangiite Microscópica/tratamento farmacológico , Poliangiite Microscópica/etiologia , Pessoa de Meia-Idade , Análise de Componente Principal , Estudos Prospectivos , Recidiva , Indução de Remissão
2.
J Eur Acad Dermatol Venereol ; 34(6): 1324-1330, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31923338

RESUMO

BACKGROUND: The Japanese guidelines for the management of pemphigus (JG) were published in 2010. However, further progress in the treatment of pemphigus requires their validation. OBJECTIVES: To examine the efficacy and safety of treatments based on the JG. METHODS: A retrospective study of 84 Japanese patients with moderate to severe pemphigus, who were initially treated in accordance with the JG and then followed up for >2 years, was performed in a single centre. Treatment typically consisted of 0.5-1 mg prednisone (PSL)/kg/day accompanied by 100 mg azathioprine/day as a steroid-sparing agent. RESULTS: In 83 of the 84 patients (98.8%), complete remission on minimal therapy (≤10 mg PSL/day and concomitant immunosuppressive agent) was achieved. The time between initiation of therapy and remission was 13.9 ± 9.4 months. In 78 patients (92.9%), remission was accomplished within the 2-year follow-up. The 32 patients with recalcitrant disease (38.1%) received additional treatment. Relapse occurred in 12 patients (14.3%) either during tapering of the PSL dose (six patients) or after achieving remission (six patients). Adverse events, mostly liver enzyme elevation, infections and diabetes, occurred in 67 patients (79.8%). One patient (1.2%) died during the observation period after gastrointestinal haemorrhage. CONCLUSIONS: Our results suggested that the elderly and patients requiring additional therapies were at higher risk of adverse events, including severe infections, and should thus be monitored carefully. This study provided clinical data that could inform revised guidelines and contribute to the evaluation of future novel therapies.


Assuntos
Pênfigo , Idoso , Azatioprina/uso terapêutico , Quimioterapia Combinada , Humanos , Imunossupressores/uso terapêutico , Pênfigo/tratamento farmacológico , Prednisona/uso terapêutico , Estudos Retrospectivos , Resultado do Tratamento
3.
Thorac Cardiovasc Surg ; 59(1): 34-9, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21243570

RESUMO

BACKGROUND: To perform a minimally invasive repair for pectus excavatum safely, accurate knowledge of the anatomy of the retrosternal region is crucial. This study was carried out to provide more information on this region. METHODS: 1. Using 32 human cadavers, the vascular structure in the retrosternal region was studied. 2. The pleura, transverse thoracic ligament, pericardium, and diaphragm were taken from 10 fresh cadavers, and their thicknesses and breaking strengths were measured. RESULTS: Thick vessels connecting the internal mammary vessels and anterosuperior phrenic vessels were present in a certain number of cadavers. This presence of a vascular communication was observed in 44 % of left thoracic cavities and 12.5 % of right thoracic cavities. The breaking strengths of the pericardium and diaphragm were found to be nearly ten times greater than that of the pleura. CONCLUSIONS: Care should be taken not to injure vessels connecting the internal mammary vessels and anterosuperior phrenic vessels when performing retrosternal undermining of the xiphoid region. Since the pericardium is much thicker than the pleura, injury of the pericardium can be avoided by careful undermining.


Assuntos
Tórax em Funil/cirurgia , Procedimentos Ortopédicos/métodos , Parede Torácica/anormalidades , Parede Torácica/cirurgia , Toracoscopia , Tórax/patologia , Cadáver , Tórax em Funil/patologia , Humanos , Procedimentos Cirúrgicos Minimamente Invasivos , Resultado do Tratamento
4.
J Synchrotron Radiat ; 17(6): 813-6, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20975230

RESUMO

The understanding of and in situ observation of the transport and distribution of water in carbon-paper gas diffusion layers (GDLs) using non-destructive imaging techniques is critical for achieving high performance in polymer electrolyte fuel cells (PEFCs). To investigate the behavior of water in GDLs of PEFCs, phase-contrast X-ray imaging via X-ray interferometric imaging (XII) and diffraction-enhanced imaging (DEI) were performed using 35 keV X-rays. The XII technique is useful for the radiographic imaging of GDLs and in situ observations of water evolution processes in operating PEFCs. DEI provides a way for tomographic imaging of GDLs in PEFCs. Because high-energy X-rays are applicable to the imaging of both carbon papers and heavy materials, which make up PEFCs, phase-contrast X-ray imaging techniques have proven to be valuable for investigation of GDLs.

5.
Biochimie ; 176: 110-116, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32623049

RESUMO

Obesity is a major health problem worldwide. Overweight and obesity directly affect health-related quality of life and also have an important economic impact on healthcare systems. In experimental models, obesity leads to hypothalamic inflammation and loss of metabolic homeostasis. It is known that macroautophagy is decreased in the hypothalamus of obese mice but the role of chaperone-mediated autophagy is still unknown. In this study, we aimed to investigate the role of hypothalamic chaperone-mediated autophagy in response to high-fat diet and also the direct effect of palmitate on hypothalamic neurons. Mice received chow or high-fat diet for 3 days or 1 week. At the end of the experimental protocol, chaperone-mediated autophagy in hypothalamus was investigated, as well as cytokines expression. In other set of experiments, neuronal cell lines were treated with palmitic acid, a saturated fatty acid. We show that chaperone-mediated autophagy is differently regulated in response to high-fat diet intake for 3 days or 1 week. Also, when hypothalamic neurons are directly exposed to palmitate there is activation of chaperone-mediated autophagy. High-fat diet causes hypothalamic inflammation concomitantly to changes in the content of chaperone-mediated autophagy machinery. It remains to be studied the direct role of inflammation and lipids itself on the activation of chaperone-mediated autophagy in the hypothalamus in vivo and also the neuronal implications of chaperone-mediated autophagy inhibition in response to obesity.


Assuntos
Autofagia Mediada por Chaperonas/efeitos dos fármacos , Dieta Hiperlipídica/efeitos adversos , Hipotálamo/metabolismo , Neurônios/metabolismo , Obesidade/metabolismo , Ácido Palmítico/farmacologia , Animais , Linhagem Celular , Hipotálamo/patologia , Camundongos , Neurônios/patologia , Obesidade/induzido quimicamente , Obesidade/patologia , Ácido Palmítico/metabolismo
6.
Benef Microbes ; 10(7): 801-810, 2019 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-31965845

RESUMO

The aim of this study was to analyse hypoxia-associated dendritic cells (DCs) in colitic mice and the effects of probiotics on interleukin (IL)-10 production in inflammatory DCs under hypoxic conditions. Extensive hypoxia was observed in the colonic mucosa of dextran sodium sulphate-induced colitic mice. Flow cytometric analysis demonstrated that hypoxia-inducible factor-1α+ DCs in colonic lamina propria (CLP) lymphocytes and mesenteric lymph nodes (MLN) were more abundant in colitic mice than those in controls. Among three subsets of DCs, i.e. plasmacytoid DCs, conventional DCs (cDCs), and monocyte-derived DCs (mDCs), cDCs and mDCs were more abundant in CLP of colitic mice. Bone marrow-derived Flt-3L-induced DCs (Flt-DCs) but not bone marrow-derived GM-CSF-induced DCs (GM-DCs), incubated with 1% O2 exhibited an inflammatory phenotype, with higher CD86, IL-6, and tumour necrosis factor-α expression, and lower IL-10 levels than those in Flt-DCs incubated with 21% O2. The hypoxia-induced decrease in IL-10 expression in Flt-DCs was restored by Bifidobacterium bifidum JCM 1255T promoted IL-10 expression through the p38 pathway under normoxic conditions. The anti-inflammatory effects of B. bifidum JCM 1255T in Flt-DCs were mediated through different cellular mechanisms under hypoxic and normoxic conditions. B. bifidum JCM 1255T could be used therapeutically for its anti-inflammatory effects.


Assuntos
Células Dendríticas/patologia , Hipóxia/imunologia , Inflamação , Interleucina-10/biossíntese , Oxigênio/metabolismo , Probióticos , Animais , Diferenciação Celular , Células Cultivadas , Colite/induzido quimicamente , Colo/patologia , Células Dendríticas/imunologia , Feminino , Hipóxia/induzido quimicamente , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Linfonodos/imunologia , Linfonodos/patologia , Camundongos , Camundongos Endogâmicos BALB C , Mucosa/imunologia , Mucosa/patologia
7.
Immunohematology ; 23(4): 146-9, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-18284304

RESUMO

The low-prevalence MNS blood group antigenTSEN is located at the junction of glycophorin A (GPA) to glycophorin B (GPB) in several hybrid glycophorin molecules. Extremely rare people have RBCs with a double dose of the TSEN antigen and have made an antibody to a high-prevalence MNS antigen. We report the first patient who is heterozygous for GYP.JL and Mk. During prenatal tests,an alloantibody to a high-prevalence antigen was detected in the serum of a 21-year-old Hispanic woman. The antibody detected an antigen resistant to treatment by papain, trypsin, alpha-chymotrypsin, or DTT. The antibody was strongly reactive by the IAT with all RBCs tested except those having the MkMk, GP.Hil/GP.Hil, or GP.JL/GP.JL phenotypes. The patient's RBCs typed M+N-S+/-s-U+, En(a+/-), Hut-, Mi(a-), Mur-, Vw-, Wr(a-b-), and were TSEN+, MINY+. Reactivity with Glycine soja suggested that her RBCs had a decreased level of sialic acid. Immunoblotting showed the presence of monomer and dimer forms of a GP(A-B) hybrid and an absence of GPA and GPB. Sequencing of DNA and PCR-RFLP using the restriction enzyme RsaI confirmed the presence of a hybrid GYP(AB). The patient's antibody was determined to be anti-EnaFR. She is the first person reported with the GP.JL phenotype associated with a deletion of GYPA and GYPB in trans to GYP.JL.


Assuntos
Glicoforinas/química , Glicoforinas/imunologia , Isoanticorpos/sangue , Isoantígenos/química , Sistema do Grupo Sanguíneo MNSs/genética , Fenótipo , Adulto , Sequência de Bases , Tipagem e Reações Cruzadas Sanguíneas/métodos , Membrana Eritrocítica/química , Membrana Eritrocítica/imunologia , Eritrócitos/química , Eritrócitos/imunologia , Feminino , Genótipo , Hemaglutinação/imunologia , Humanos , Recém-Nascido , Isoanticorpos/imunologia , Polimorfismo de Fragmento de Restrição/imunologia , Gravidez , Espanha
8.
Oncogene ; 35(25): 3249-59, 2016 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-26477314

RESUMO

The MST1R gene is overexpressed in pancreatic cancer producing elevated levels of the RON tyrosine kinase receptor protein. While mutations in MST1R are rare, alternative splice variants have been previously reported in epithelial cancers. We report the discovery of a novel RON isoform discovered in human pancreatic cancer. Partial splicing of exons 5 and 6 (P5P6) produces a RON isoform that lacks the first extracellular immunoglobulin-plexin-transcription domain. The splice variant is detected in 73% of xenografts derived from pancreatic adenocarcinoma patients and 71% of pancreatic cancer cell lines. Peptides specific to RON P5P6 detected in human pancreatic cancer specimens by mass spectrometry confirm translation of the protein isoform. The P5P6 isoform is found to be constitutively phosphorylated, present in the cytoplasm, and it traffics to the plasma membrane. Expression of P5P6 in immortalized human pancreatic duct epithelial (HPDE) cells activates downstream AKT, and in human pancreatic epithelial nestin-expressing cells, activates both the AKT and MAPK pathways. Inhibiting RON P5P6 in HPDE cells using a small molecule inhibitor BMS-777607 blocked constitutive activation and decreased AKT signaling. P5P6 transforms NIH3T3 cells and induces tumorigenicity in HPDE cells. Resultant HPDE-P5P6 tumors develop a dense stromal compartment similar to that seen in pancreatic cancer. In summary, we have identified a novel and constitutively active isoform of the RON tyrosine kinase receptor that has transforming activity and is expressed in human pancreatic cancer. These findings provide additional insight into the biology of the RON receptor in pancreatic cancer and are clinically relevant to the study of RON as a potential therapeutic target.


Assuntos
Transformação Celular Neoplásica/genética , Células Epiteliais/metabolismo , Ductos Pancreáticos/citologia , Receptores Proteína Tirosina Quinases/genética , Adenocarcinoma/genética , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Processamento Alternativo , Animais , Western Blotting , Células COS , Linhagem Celular , Linhagem Celular Tumoral , Membrana Celular/metabolismo , Transformação Celular Neoplásica/metabolismo , Chlorocebus aethiops , Citoplasma/metabolismo , Éxons/genética , Humanos , Isoenzimas/genética , Isoenzimas/metabolismo , Camundongos Endogâmicos NOD , Camundongos Knockout , Camundongos SCID , Microscopia Confocal , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Fosforilação , Receptores Proteína Tirosina Quinases/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transplante Heterólogo
9.
Biochim Biophys Acta ; 1418(2): 320-34, 1999 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-10320683

RESUMO

OBJECTIVE: To study the interaction between salicylate and class 1 antiarrhythmic agents. METHODS: The effects of salicylate on class 1 antiarrhythmic agent-induced tonic and phasic block of the Na+ current (INa) of ventricular myocytes and the upstroke velocity of the action potential (Vmax) of papillary muscles were examined by both the patch clamp technique and conventional microelectrode techniques. RESULTS: Salicylate enhanced quinidine-induced tonic and phasic block of INa at a holding potential of -100 mV but not at a holding potential of -140 mV; this enhancement was accompanied by a shift of the hinfinity curve in the presence of quinidine in a further hyperpolarized direction, although salicylate alone did not affect INa. Salicylate enhanced the tonic and phasic block of Vmax induced by quinidine, aprindine and disopyramide but had little effect on that induced by procainamide or mexiletine; the enhancing effects were related to the liposolubility of the drugs. CONCLUSIONS: Salicylate enhanced tonic and phasic block of Na+ channels induced by class 1 highly liposoluble antiarrhythmic agents. Based on the modulated receptor hypothesis, it is probable that this enhancement was mediated by an increase in the affinity of Na+ channel blockers with high lipid solubility to the inactivated state channels.


Assuntos
Antiarrítmicos/farmacologia , Ventrículos do Coração/efeitos dos fármacos , Músculos Papilares/efeitos dos fármacos , Salicilatos/farmacologia , Bloqueadores dos Canais de Sódio , Potenciais de Ação , Animais , Células Cultivadas , Sinergismo Farmacológico , Cobaias , Microeletrodos , Técnicas de Patch-Clamp , Quinidina/farmacologia
10.
Br J Pharmacol ; 104(1): 25-30, 1991 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1664763

RESUMO

1. Sodium current (INa) blockade by TYB-3823, a newly synthesized antiarrhythmic agent, was investigated in isolated single ventricular myocytes by use of the whole cell patch-clamp technique. 2. TYB-3823 blocked INa under steady-state conditions (Kd,rest = 500 microM, Kd,i = 4.9 microM), findings consistent with a shift in the steady state INa availability curve to more negative potentials. 3. TYB-3823 produced use-dependent block at 2 Hz in conjunction with increase in pulse duration (5-300 ms), that was markedly enhanced at less negative holding potentials. 4. The time course of the onset of block was accelerated and the degree of use-dependent block was decreased at more negative holding potential. The time course of the onset of block was accentuated with enhancing block at more positive holding potentials. 5. The time course of recovery from use-dependent block was accelerated at more negative holding potentials but was accentuated at more positive holding potentials. 6. These results suggest that both tonic block and use-dependent block of sodium channels in cardiac tissue might result from an interaction of TYB-3832 with sodium channels mainly in the inactivated channel states and the kinetics of the interaction between drug and receptor may be modulated by the inactivation gate.


Assuntos
Antiarrítmicos/farmacologia , Guanidinas/farmacologia , Miocárdio/metabolismo , Canais de Sódio/metabolismo , Animais , Cobaias , Coração/efeitos dos fármacos , Técnicas In Vitro , Miocárdio/citologia , Canais de Sódio/efeitos dos fármacos
11.
Cancer Lett ; 48(3): 189-95, 1989 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-2514040

RESUMO

Formation of DNA-adducts by 3-BHA or its metabolites, i.e., tert-butyl-1,4-benzoquinone (TBQ) and 5-methoxy-3-tert-butyl-1,2-benzoquinone (3-TBOQ), as well as DNA-adduct formation by 4-nitroquinoline-N-oxide (4NQO), in rat forestomach were examined by an enzymatic 32P-postlabeling assay. Four DNA-adducts were clearly detected in the forestomach after treatment of rats with 4NQO. The sensitivity was 1.9 certain adducts per 10(8) normal nucleotides. On the contrary, no DNA adducts were detected in the forestomach of rats given either a single or repeated oral administration (5 days) of 3-BHA, TBQ or 3-TBOQ. The analyses were carried out under conditions which could detect the DNA-adducts produced by reaction of TBQ with calf thymus DNA in vitro. The results suggest that formation of aromatic adducts in vivo by 3-BHA, TBQ or 3-TBOQ in the rat forestomach-DNA is not evident or at least below the detection limits of the current bioassay.


Assuntos
Benzoquinonas , Hidroxianisol Butilado/metabolismo , DNA/metabolismo , Mucosa Gástrica/metabolismo , 4-Nitroquinolina-1-Óxido/metabolismo , Animais , Masculino , Radioisótopos de Fósforo , Quinonas/metabolismo , Ratos , Ratos Endogâmicos F344 , Compostos de Sulfidrila/metabolismo
12.
Environ Health Perspect ; 14: 15-28, 1976 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-789062

RESUMO

Synthetic pyrethroidal compounds undergo biodegradation in mammals both oxidatively and hydrolytically, and depending on the type of compound, either of the pathways may predominate. Thus, (+) - or (+/-) -trans isomers of the chrysanthemumate ester of primary alcohols such as fenothrin, furamethrin, proparthrin, resmethrin, and tetramethrin (and possibly permethrin, too) are metabolized mainly through hydrolysis of the ester linkage, with subsequent oxidation and/or conjugation of the component alcohol and acid moieties. On the other hand, the corresponding (+)-cis enantiometers and chrysanthemumate of secondary alcohols like allethrin are resistant to hydrolytic attack, and biodegraded via oxidation at various sites of the molecule. These rapid metabolic degradations, together with the presumable incomplete absorption from the gastrointestinal tract, would generally contribute to the low acute toxicity of synthetic pyrethroids. These compounds are neither skin irritants nor skin sensitizers, and inhalation toxicity as well as dermal toxicity are fairly low. Neither is teratogenic in rats, mice, and/or rabbits or mutagenic on various bacterial strains. Subacute and chronic feeding of higher amounts of the compounds to rats invariably causes some histopathological changes in liver; however, these are neither indicative nor suggestive of tumorigenicity. Based on existing toxicological information, the present recommended use patterns might afford sufficient safety margin on human population. However, in extending usage to agricultural pest control, much more extensive investigations should be forthcoming from both chemical and biological aspects, since there is scant information on the fate of these pyrethroids in the environment. Also several of the compounds may be very toxic to certain kinds of fish and arthropods.


Assuntos
Piretrinas , Administração Oral , Aerossóis , Animais , Biodegradação Ambiental , Daphnia , Cães , Meio Ambiente , Peixes , Cobaias , Camundongos , Mutagênicos , Piretrinas/administração & dosagem , Piretrinas/metabolismo , Piretrinas/toxicidade , Coelhos , Ratos , Pele/efeitos dos fármacos , Teratogênicos , Fatores de Tempo
13.
J Exp Psychol Gen ; 117(1): 3-20, 1988 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-2966229

RESUMO

Survival duration and health quality are fundamentally important aspects of health. A utility model for survival duration and health quality is a model of the subjective value of these attributes. We investigate the hypothesis that the utility (subjective value) of survival duration and health quality is determined by a multiplicative model. According to this model, there are separate subjective scales for the utility of survival duration and health quality. If F(Y) equals the utility of surviving Y years, and G(Q) equals the utility of living in health state Q, then the multiplicative model proposes that F(Y)G(Q) equals the utility of surviving Y years in health state Q. This model provides a simple explanation for several intuitively compelling relationships. First, the distinction between better-than-death and worse-than-death health states corresponds to the assignment of positive or negative utilities to different health states. Second, a zero duration of survival removes any reason to prefer one health state over any other, just as multiplying the utility of health quality by zero eliminates differences between the utilities of different health states. Third, the subjective difference between Y years in pain and Y years free from pain increases as Y increases as if the difference in utility between pain and no pain were being multiplied by the utility of surviving Y years. A critical prediction of the multiplicative model is the hypothesis that preferences between gambles for health outcomes satisfy a property called utility independence. Individual analyses revealed that most subjects satisfy utility independence, thereby supporting the multiplicative utility model. Some subjects appear to violate a fundamental assumption of utility theory: They appear to violate the assumption that a single utility scale represents both the ordinal preference relations between certain outcomes and the subjective averaging that underlies the utility of gambles. The violation is inferred from an inconsistency between preferences for multiattribute outcomes when they are viewed as certain outcomes and when they are viewed as the outcomes of gambles.


Assuntos
Doença Crônica/terapia , Qualidade de Vida , Papel do Doente , Atividades Cotidianas , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dor/psicologia
14.
J Biochem ; 130(5): 597-603, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11686921

RESUMO

When human erythrocytes were preincubated at 37-52 degrees C under atmospheric pressure before exposure to a pressure of 200 MPa at 37 degrees C, the value of hemolysis was constant (about 43%) up to 45 degrees C but became minimal at 49 degrees C. The results from anti-spectrin antibody-entrapped red ghosts, spectrin-free vesicles, and N-(1-pyrenyl)iodoacetamide-labeled ghosts suggest that the denaturation of spectrin is associated with such behavior of hemolysis at 49 degrees C. The vesicles released at 200 MPa by 49 degrees C-preincubated erythrocytes were smaller than those released by the treatment at 49 degrees C or 200 MPa alone. The size of vesicles released at 200 MPa was independent of preincubation temperature up to 45 degrees C, and the vesicles released from 49 degrees C-preincubated erythrocytes became smaller with increasing pressure up to 200 MPa. Thus, hemolysis and vesiculation under high pressure are greatly affected by the conformation of spectrin before compression. Since spectrin remains intact up to 45 degrees C, the compression of erythrocytes at 200 MPa induces structural changes of spectrin followed by the release of large vesicles and hemolysis. On the other hand, in erythrocytes that are undergoing vesiculation due to spectrin denaturation at 49 degrees C, compression produces smaller vesicles, so that the hemolysis is suppressed.


Assuntos
Pressão do Ar , Citoesqueleto/química , Membrana Eritrocítica/metabolismo , Eritrócitos/metabolismo , Calefação , Hemólise/fisiologia , Espectrina/química , Humanos , Pressão Osmótica , Conformação Proteica , Desnaturação Proteica , Espectrina/metabolismo
15.
Obstet Gynecol ; 63(5): 639-44, 1984 May.
Artigo em Inglês | MEDLINE | ID: mdl-6425749

RESUMO

To investigate the changes in pituitary responsiveness to hypothalamic releasing hormones during the periparturitional period, women undergoing labor and vaginal delivery were stimulated with thyrotropin-releasing hormone. The percentage of incremental changes in prolactin and thyroid-stimulating hormone were significantly lower in pregnant women at term than in nonpregnant control subjects. Evidence of augmented release of prolactin was disclosed after the onset of active labor. The percent increases in prolactin and thyroid-stimulating hormone were significantly higher at 24 hours post partum than at term. Administration of thyrotropin-releasing hormone to the gravid patient in active labor caused a brisk response in fetal thyroid-stimulating hormone, although the increase in fetal prolactin remained low. These findings suggest that the changes in serum triiodothyronine (T3) significantly influence the release of prolactin and thyroid-stimulating hormone in response to thyrotropin-releasing hormone during the periparturitional period.


Assuntos
Trabalho de Parto , Período Pós-Parto , Prolactina/sangue , Hormônio Liberador de Tireotropina/farmacologia , Tireotropina/sangue , Adulto , Relação Dose-Resposta a Droga , Feminino , Humanos , Infusões Parenterais , Gravidez , Hormônio Liberador de Tireotropina/administração & dosagem , Tiroxina/sangue , Tri-Iodotironina/sangue
16.
Eur J Pharmacol ; 409(1): 81-4, 2000 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-11099703

RESUMO

The effects of the selective serotonin (5-hydroxytryptamine (5-HT)) reuptake inhibitor fluvoxamine, given alone or in combination with the benzodiazepine anxiolytic diazepam on the defensive freezing behavior of mice in the conditioned fear stress paradigm were examined. Fluvoxamine (5-20 mg/kg, i.p.) induced a dose-dependent reduction in freezing behavior. In contrast, while low doses of diazepam (0.125 and 0.25 mg/kg, i.p.) reduced the freezing behavior, such effects were not observed with high doses of diazepam (0.5 and 1 mg/kg, i.p.). In the combination study, fluvoxamine (20 mg/kg, i.p. ) did not reduce the freezing behavior in mice that had been pretreated with diazepam (0.125-1 mg/kg, i.p.). None of the doses of fluvoxamine and diazepam used in the present study had any effects on motor activity under non-stressed conditions. These results suggest that benzodiazepines may negatively influence the clinical efficacy of selective 5-HT reuptake inhibitors in the treatment of anxiety disorders.


Assuntos
Ansiolíticos/farmacologia , Antidepressivos de Segunda Geração/farmacologia , Comportamento Animal/efeitos dos fármacos , Diazepam/farmacologia , Medo/psicologia , Fluvoxamina/farmacologia , Estresse Psicológico/psicologia , Animais , Condicionamento Psicológico/efeitos dos fármacos , Masculino , Camundongos
17.
Eur J Pharmacol ; 153(2-3): 285-8, 1988 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-2846319

RESUMO

The depression of Vmax of the action potential in guinea-pig ventricular muscle by aprindine and quanidine was compared. Aprindine caused a more pronounced rate-dependent block (Kd = 10(-6) M at 3.3 Hz) than did quinidine (Kd = 1.6 X 10(-5) M at 3.3 Hz). Aprindine shifted the relationship between Vmax and resting potential to a more negative potential (mean 9.2 mV: 10 microM) than did quinidine (mean 5.7 mV: 10 microM). In addition, aprindine caused a more pronounced resting block (Kd = 1.3 X 10(-5) M) than quinidine (Kd = 8.6 X 10(-5) M). It is concluded that aprindine has a higher affinity for activated and/or inactivated and resting state channels than quinidine, making channels unavailable for conduction upon activation.


Assuntos
Aprindina/farmacologia , Indenos/farmacologia , Músculos Papilares/efeitos dos fármacos , Quinidina/farmacologia , Potenciais de Ação/efeitos dos fármacos , Animais , Estimulação Elétrica , Cobaias , Técnicas In Vitro , Cinética , Potenciais da Membrana/efeitos dos fármacos , Músculos Papilares/fisiologia , Canais de Sódio/efeitos dos fármacos , Canais de Sódio/metabolismo
18.
Eur J Pharmacol ; 154(2): 197-202, 1988 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-3229441

RESUMO

We studied the effects of mianserin on the action potentials of papillary muscle from the guinea-pig. Mianserin (above 10 microM) reduced the maximum rate of the rise (Vmax) of the action potential, and shifted the Vmax-Em relationship to more negative potentials. The compound also depressed the slow action potentials of K+-depolarized papillary muscles. It is concluded that relatively high concentrations of mianserin had an inhibitory action on the electrophysiological properties of both the fast- and slow-response fibers of the heart.


Assuntos
Coração/efeitos dos fármacos , Mianserina/farmacologia , Potenciais de Ação/efeitos dos fármacos , Animais , Cobaias , Coração/fisiologia , Técnicas In Vitro , Potenciais da Membrana/efeitos dos fármacos , Músculos Papilares/efeitos dos fármacos
19.
Eur J Pharmacol ; 179(3): 447-51, 1990 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-2163858

RESUMO

Under whole cell patch conditions, 1389-S blocked the INa in guinea-pig ventricular myocytes under steady state conditions (Kdrest = 30 microM, Kdi = 2.4 microM) with a shift of the inactivation curve to the hyperpolarizing direction. Both brief and long conditioning pulses could produce a use-dependent block of 1389-S. These results suggest that 1389-S had a higher affinity to the inactivated than to the rested state under steady state conditions and had a higher affinity to the activated state during train pulses as well as to the inactivated state, making channels unavailable for conduction upon activation.


Assuntos
Miocárdio/metabolismo , Propanolaminas/farmacologia , Canais de Sódio/efeitos dos fármacos , Animais , Estimulação Elétrica , Cobaias , Coração/efeitos dos fármacos , Coração/fisiologia , Técnicas In Vitro , Miocárdio/citologia
20.
Toxicology ; 43(2): 139-47, 1987 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-3810657

RESUMO

The mechanism of the carcinogenic or toxic action of BHA on rat forestomach was examined by studies on the excretion and tissue distribution of radioactivity in F344 male rats given tert-butyl- or methoxy-labelled 3-BHA orally. Within 2 days after a single oral dose of labelled BHA at 1 g/kg body wt, 87-96% of the 14C was excreted, mainly in the urine with smaller amounts in the feces and expired air. More 14C was found in the tissues of rats given the methoxy-labelled compounds. The distributions of 14C in the forestomach and the glandular stomach were similar. At 168 h after treatment, more 14C was found in the forestomach of rats given 2-BHA than in that of rats given 3-BHA. These results indicate that excretion of BHA is rapid, that 4-O-methyl demethylation may take place readily and that demethylated methyl group may become distributed non-specifically in tissues. The carcinogenic or toxic action of BHA on the forestomach does not seem to be due accumulation of BHA in the forestomach.


Assuntos
Ar/análise , Hidroxianisol Butilado/metabolismo , Fezes/análise , Animais , Testes Respiratórios , Hidroxianisol Butilado/urina , Feminino , Masculino , Ratos , Ratos Endogâmicos F344 , Distribuição Tecidual
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