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3.
Br J Pharmacol ; 157(7): 1250-62, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19563534

RESUMO

BACKGROUND AND PURPOSE: TAK-242, a novel synthetic small-molecule, suppresses production of multiple cytokines by inhibiting Toll-like receptor (TLR) 4 signalling. In this study, we investigated the target molecule of TAK-242 and examined its therapeutic effect in a mouse sepsis model. EXPERIMENTAL APPROACH: Binding assay with [(3)H]-TAK-242 and nuclear factor-kappaB reporter assay were used to identify the target molecule and binding site of TAK-242. Bacillus calmette guerin (BCG)-primed mouse sepsis model using live Escherichia coli was used to estimate the efficacy of TAK-242 in sepsis. KEY RESULTS: TAK-242 strongly bound to TLR4, but binding to TLR2, 3, 5, 9, TLR-related adaptor molecules and MD-2 was either not observed or marginal. Mutational analysis using TLR4 mutants indicated that TAK-242 inhibits TLR4 signalling by binding to Cys747 in the intracellular domain of TLR4. TAK-242 inhibited MyD88-independent pathway as well as MyD88-dependent pathway and its inhibitory effect was largely unaffected by lipopolysaccharide (LPS) concentration and types of TLR4 ligands. TAK-242 had no effect on the LPS-induced conformational change of TLR4-MD-2 and TLR4 homodimerization. In mouse sepsis model, although TAK-242 alone did not affect bacterial counts in blood, if co-administered with ceftazidime it inhibited the increases in serum cytokine levels and improved survival of mice. CONCLUSIONS AND IMPLICATIONS: TAK-242 suppressed TLR4 signalling by binding directly to a specific amino acid Cys747 in the intracellular domain of TLR4. When co-administered with antibiotics, TAK-242 showed potent therapeutic effects in an E. coli-induced sepsis model using BCG-primed mice. Thus, TAK-242 may be a promising therapeutic agent for sepsis.


Assuntos
Sepse/tratamento farmacológico , Sulfonamidas/farmacologia , Receptor 4 Toll-Like/fisiologia , Animais , Sítios de Ligação , Ligação Competitiva , Linhagem Celular , Chlorocebus aethiops , Escherichia coli , Genes Reporter , Humanos , Ligantes , Lipopolissacarídeos/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Mycobacterium bovis , Fator 88 de Diferenciação Mieloide/fisiologia , NF-kappa B/genética , Conformação Proteica , Multimerização Proteica , Estrutura Terciária de Proteína , Ensaio Radioligante , Sepse/microbiologia , Transdução de Sinais/efeitos dos fármacos , Sulfonamidas/uso terapêutico
4.
Br J Dermatol ; 147(2): 368-70, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12174115

RESUMO

Exercise-induced anaphylaxis (EIA) is a form of physical urticaria that is induced by exercise. A 16-year-old Japanese boy had a 4-year history of recurrent wealing and dyspnoea after physical exercise such as jogging, playing handball or riding a bicycle in winter. The episodes were not associated with ingestion of foods including wheat or soya bean. A provocation test, with 15 min of exercise and 2 min of cold stimulation immediately before or immediately after the exercise, elicited a weal that was localized to the test area. A challenge test with ingestion of boiled soya beans and exercise did not elicit a weal. Therefore, in this case, cold exposure, but not food ingestion, was essential for inducing EIA. Cold-dependent EIA is different from cold urticaria, food-dependent EIA, cholinergic urticaria and cold-induced cholinergic urticaria, and may be a distinct entity.


Assuntos
Temperatura Baixa/efeitos adversos , Exercício Físico , Hipersensibilidade/etiologia , Adolescente , Diagnóstico Diferencial , Teste de Esforço/efeitos adversos , Humanos , Hipersensibilidade/diagnóstico , Masculino , Anafilaxia Cutânea Passiva , Testes Cutâneos
5.
Cardiovasc Res ; 52(3): 500-8, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11738067

RESUMO

OBJECTIVE: Beraprost sodium (BPS), a prostacyclin (PGI(2)) analogue, has been reported to exhibit beneficial effects on atherosclerosis in both human and animal models. To clarify the underlying mechanism, we investigated the effects of BPS on neointimal formation after balloon injury in the canine coronary artery. Furthermore, we determined its anti-atherosclerotic effects in cultured smooth muscle cells (SMCs). METHODS: Adult beagle dogs (10-12 kg) were fed on a high-cholesterol diet (10 g/day) and underwent balloon-denudation of the coronary artery. The dogs were divided into two groups: a BPS-treated group (20 microg/kg per day) and a control group. Twenty-eight days after injury, the dogs were killed and the coronary arteries were examined morphometrically. Three days after injury, the proliferative activity in the medial layer of the coronary artery was evaluated by 5-bromo-2'-deoxyuridine (BrdU) incorporation, and p27(Kip1), a cyclin-dependent kinase (cdk) inhibitor, expression was examined by immunohistochemistry. We also examined the effects of BPS on SMC proliferation based on BrdU incorporation and cell cycle analysis. In addition, p27(Kip1) regulation was evaluated in primary-cultured SMCs. RESULTS: BPS administration decreased the intima/media ratio (I/M) by 88% in the control group. Three days after injury, BPS attenuated the proliferation rate of the cells in the media of the coronary artery by 35%, and maintained p27(Kip1) expression, which declined in the control cells. In the cultured proliferating SMC, BPS prevented the down-regulation of p27(Kip1). The 8-bromo-cyclic adenosine monophosphate (8-br-cAMP), a cAMP analogue, had similar actions as BPS in the regulation of p27(Kip1). The proliferation of cultured SMC was inhibited in a dose-dependent manner, and cell cycle arrest in the G1 phase was induced by BPS. CONCLUSIONS: Our data suggest that BPS inhibits neointimal formation after balloon denudation in the coronary artery through its inhibitory effect on SMC proliferation by preventing p27(Kip1) down-regulation.


Assuntos
Angioplastia Coronária com Balão/efeitos adversos , Reestenose Coronária/patologia , Epoprostenol/análogos & derivados , Epoprostenol/farmacologia , Músculo Liso Vascular/patologia , Transdução de Sinais/efeitos dos fármacos , Vasodilatadores/farmacologia , Animais , Ciclo Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Reestenose Coronária/tratamento farmacológico , Vasos Coronários , AMP Cíclico/metabolismo , Cães , Epoprostenol/uso terapêutico , Feminino , Citometria de Fluxo , Modelos Animais , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/metabolismo , Vasodilatadores/uso terapêutico
6.
J Biol Chem ; 276(27): 24704-12, 2001 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-11320097

RESUMO

Cytochrome oxidase subunits I, II, and III, the mitochondrial DNA-encoded proteins, are inserted across the inner membrane by the Oxa1p-containing translocator in a membrane potential-dependent manner. Oxa1p is also involved in the insertion of the cytoplasmically synthesized precursor of Oxa1p itself into the inner membrane from the matrix via the conservative sorting pathway. The mechanism of insertion of the other mitochondrially synthesized proteins, however, is unexplored. The insertion of the mitochondrial DNA-encoded subunit 8 of F(1)F(0)-ATPase (Su8) across the inner membrane was analyzed in vitro using the inverted inner membrane vesicles and the Escherichia coli lysate-synthesized substrate. This assay revealed that the N-terminal segment of Su8 inserted across the membrane to the intermembrane space and assumed the correct trans-cis topology depending on the mitochondrial matrix fraction. This translocation reaction was similar to those of Sec-independent, direct insertion pathways of E. coli and chloroplast thylakoid membranes. (i) It required neither nucleotide triphosphates nor membrane potential, and hydrophobic forces drove the process. (ii) It did not require protease-sensitive membrane components facing the matrix space. (iii) It could be inserted across liposomes in the correct topology in a matrix fraction-dependent manner. Thus, a novel mechanism conserved in bacteria and chloroplasts also functions in the insertion of Su8 across the mitochondrial inner membrane.


Assuntos
DNA Mitocondrial/metabolismo , Membranas Intracelulares/metabolismo , ATPases Translocadoras de Prótons/metabolismo , Sequência de Aminoácidos , Animais , Complexo IV da Cadeia de Transporte de Elétrons , Eletroforese em Gel de Poliacrilamida , Escherichia coli , Potenciais da Membrana , Proteínas Mitocondriais , Dados de Sequência Molecular , Proteínas Nucleares/metabolismo , Conformação Proteica , Processamento de Proteína Pós-Traducional , ATPases Translocadoras de Prótons/genética , Ratos
7.
Nihon Koshu Eisei Zasshi ; 48(1): 16-27, 2001 Jan.
Artigo em Japonês | MEDLINE | ID: mdl-11235122

RESUMO

PURPOSE: This article examines the demand for influenza vaccination in Japan. METHODS: Original date were obtained from a survey conducted by the authors. Two approaches, usual demand analysis and conjoint analysis, were employed. The second approach, conjoint analysis, uses people's statements on how they would respond to different hypothetical situations. In this research, we ask people whether they wish to be vaccinated given different circumstances such as costs of vaccination, degree of convenience, and outbreak news. RESULTS: In the demand analysis, the vaccination rate during the 1999-2000 season was found to have increased by 0.8 percentage points compared to that of the previous season. The rate increased by 1.0 to 3.5 percentage points among the group of people who experienced influenza in the previous season. The vaccination rate also increased by 31-47 percentage points for those who were vaccinated in the previous season. A 10 percentage increase in household income decreased the demand for vaccination by 2 percentage points. Although household income was significant in only with the largest sample, this result may indicate that the time or opportunity cost for vaccination decreases the vaccination demand. In the conjoint analysis, the financial cost was significantly negative. When the cost was reduced from the current level of 6,000 yen to free of charge, the vaccination rate would increase by 43.5 percentage points. Were vaccination available at night or during holidays,! or at school or work, the rate would increase by 11 percentage points, or 16 percentage points, respectively. Most of all, news of influenza prevalence was very influential in increasing the desire for vaccination by 33 percentage points. Vaccination experience and last year's influenza experience were both significantly positive, increasing the rate by 22 and 8 percentage points, respectively. CONCLUSIONS: In the demand analysis, influenza experience and history of vaccination during the 1999-2000 season were found to be influential regarding the decision for vaccination. From the conjoint analysis, providing vaccination of night or during holidays, as well as at work or at schools would increase the demand. News of influenza outbreaks were also found to increase the vaccination demand. Higher income, however, was found to have a negative influence, suggesting that opportunity costs may be an important factor for some individuals. Habit formation effects through a history of vaccination plays quite an important role in vaccination demand.


Assuntos
Vacinas contra Influenza , Adulto , Atitude , Feminino , Humanos , Pessoa de Meia-Idade , Vacinação
8.
J Biol Chem ; 276(10): 7246-57, 2001 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-11073942

RESUMO

Rag A/Gtr1p are G proteins and are known to be involved in the RCC1-Ran pathway. We employed the two-hybrid method using Rag A as the bait to identify proteins binding to Rag A, and we isolated two novel human G proteins, Rag C and Rag D. Rag C demonstrates homology with Rag D (81.1% identity) and with Gtr2p of Saccharomyces cerevisiae (46.1% identity), and it belongs to the Rag A subfamily of the Ras family. Rag C and Rag D contain conserved GTP-binding motifs (PM-1, -2, and -3) in their N-terminal regions. Recombinant glutathione S-transferase fusion protein of Rag C efficiently bound to both [(3)H]GTP and [(3)H]GDP. Rag A was associated with both Rag C and Rag D in their C-terminal regions where a potential leucine zipper motif and a coiled-coil structure were found. Rag C and D were associated with both the GDP and GTP forms of Rag A. Both Rag C and Rag D changed their subcellular localization, depending on the nucleotide-bound state of Rag A. In a similar way, the disruption of S. cerevisiae GTR1 resulted in a change in the localization of Gtr2p.


Assuntos
Proteínas de Ligação ao GTP , Proteínas Monoméricas de Ligação ao GTP/química , Proteínas Monoméricas de Ligação ao GTP/genética , Proteínas de Saccharomyces cerevisiae , Motivos de Aminoácidos , Sequência de Aminoácidos , Sítios de Ligação , Linhagem Celular , Núcleo Celular/metabolismo , Dimerização , Relação Dose-Resposta a Droga , Proteínas Fúngicas/química , Proteínas Fúngicas/metabolismo , Glutationa Transferase/metabolismo , Guanosina Difosfato/metabolismo , Guanosina Trifosfato/metabolismo , Células HeLa , Humanos , Immunoblotting , Leucina/química , Microscopia de Fluorescência , Modelos Genéticos , Dados de Sequência Molecular , Proteínas Monoméricas de Ligação ao GTP/metabolismo , Nucleotídeos/metabolismo , Testes de Precipitina , Ligação Proteica , Estrutura Terciária de Proteína , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Recombinantes/metabolismo , Saccharomyces cerevisiae/metabolismo , Homologia de Sequência de Aminoácidos , Fatores de Tempo , Transfecção , Técnicas do Sistema de Duplo-Híbrido , beta-Galactosidase/metabolismo
9.
Opt Lett ; 26(16): 1256-8, 2001 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-18049578

RESUMO

We present a new, simple, inexpensive, and highly precise approach to excited-state fluorescence-lifetime-based measurements. The detection system consists of a closed-loop optoelectronic arrangement containing a radio frequency resonance amplifier, a fluorescence excitation light source, a fiber-optic delay line, and a photodetector. The system exhibits auto-oscillations in the form of intensity modulation. The oscillation frequency varies with the modulation phase shift of the fluorescent light. This frequency is used as the detection parameter, which is advantageous because frequency may be measured easily, inexpensively, and with high precision. This technique is well suited for chemical or biosensor applications.

10.
Am J Physiol Cell Physiol ; 279(4): C999-1007, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11003580

RESUMO

Migration and proliferation of smooth muscle cells (SMC) contribute to neointimal formation after arterial injury. However, the relation between migration and proliferation in these cells is obscure. To discriminate between migration and proliferation, we employed a migration assay of SMC at different phases of the cell cycle. Serum-deprived SMC were synchronized in different phases of the cell cycle by addition of serum for various periods of time. Migration induced by platelet-derived growth factor B-chain homodimer was maximal in SMC that were predominantly in the late G(1) (G(1b)) phase. In addition, in nonsynchronized SMC, 65-75% of SMC that had migrated were in the G(1b) phase. Phosphorylated myosin light chain was enriched around the cell periphery in SMC in the G(1b) phase compared with SMC in the other cell cycle phases. Interestingly, the Triton X-100-insoluble fraction of myosin was remarkably decreased in G(1b)-enriched SMC. These findings suggest that migratory activity of SMC may be coupled with the G(1b) phase. The phosphorylation and retention of myosin might explain some of the properties responsible for increased migration.


Assuntos
Movimento Celular/fisiologia , Fase G1/fisiologia , Músculo Liso Vascular/citologia , Músculo Liso Vascular/metabolismo , Actinas/química , Actinas/metabolismo , Animais , Becaplermina , Adesão Celular/fisiologia , Movimento Celular/efeitos dos fármacos , Células Cultivadas , Proteínas do Citoesqueleto/metabolismo , DNA/metabolismo , Fibronectinas/metabolismo , Citometria de Fluxo , Quinase 1 de Adesão Focal , Proteína-Tirosina Quinases de Adesão Focal , Humanos , Interfase/fisiologia , Músculo Liso Vascular/efeitos dos fármacos , Cadeias Leves de Miosina/química , Cadeias Leves de Miosina/metabolismo , Octoxinol/química , Octoxinol/farmacologia , Paxilina , Fosfoproteínas/metabolismo , Fosforilação/efeitos dos fármacos , Fator de Crescimento Derivado de Plaquetas/farmacologia , Proteínas Tirosina Quinases/metabolismo , Proteínas Proto-Oncogênicas c-sis , RNA/metabolismo , Coelhos , Solubilidade/efeitos dos fármacos
11.
J Cardiol ; 35(2): 103-11, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10713931

RESUMO

Angiographical demonstration of coronary collateral circulation may suggest the presence of residual viable myocardium. The development of coronary collaterals was judged according to Rentrop's classification in 37 patients with old anteroseptal myocardial infarction and 13 control patients with chest pain syndrome. The subjects with myocardial infarction were divided into 2 groups: 17 patients with the main branch of the left coronary artery clearly identified by collateral blood flow from the contralateral coronary artery [Coll(+)group, male/female 10/7, mean age 56.6 years]and 20 patients with obscure coronary trunk [Coll(-)group, male/female 16/4, mean age 54.9 years]. Thallium-201 myocardial scintigraphy and examination of local myocardial metabolism were carried out by measuring the flux of lactic acid under dipyridamole infusion load. Coronary stenosis of 99% or total occlusion was found in only 5 of 20 patients (25%)in the Coll(-)group but in 16 of 17 patients(94%)in the Coll(+)group(p < 0.001). Redistribution of myocardial scintigraphy was found in 11 of 15 patients(73%)in the Coll(+)group, but only 3 of 18 patients (17%)in the Coll(-)group(p < 0.01). The myocardial lactic acid extraction rate was--13.2 +/- 17.0% in the Coll(+)group, but 9.1 +/- 13.2% in the Coll(-)group(p < 0.001). These results suggest that coronary collateral may contribute to minimizing the infarct area and to prediction of the presence of viable myocardium.


Assuntos
Circulação Colateral , Circulação Coronária , Infarto do Miocárdio/metabolismo , Adulto , Idoso , Angiografia Coronária , Feminino , Humanos , Ácido Láctico/metabolismo , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/diagnóstico por imagem , Infarto do Miocárdio/fisiopatologia , Cintilografia
12.
Obstet Gynecol ; 96(5 Pt 1): 775-8, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11185485

RESUMO

BACKGROUND: We describe our experience using a new self-retaining atraumatic abdominal retractor for minilaparotomy performed either alone or in conjunction with laparoscopy. TECHNIQUE: Minilaparotomy was performed by a conventional technique and the self-retaining abdominal wall retractor (Dexterity Protractor) was placed for the duration of the open surgery. EXPERIENCE: The device was employed in 72 consecutive cases in which minilaparotomy was performed either alone or in conjunction with laparoscopy. Indications for minilaparotomy included extensive myomectomies and tubal ligation reversals in fertility patients, hysterectomies, adnexal surgery, appendicitis, and either planned or incidental concomitant bowel surgery. No allergic reactions to the plastic device were noted. Postoperative evaluation demonstrated no evidence of wound infections, nerve injuries, seromas or dehiscence in the short term, nor hernia formation or other complications in the long term. CONCLUSION: The Dexterity Protractor permitted effective retraction of the abdominal wall. The device provided gentle retraction around the entire incision, excellent surgical exposure, and a barrier to specimens containing bacterial or potentially malignant cells. The method of application was uncomplicated and well-suited to abdominal walls of varying thickness. The utilization of this device was not associated with wound-related complications in this study of patients.


Assuntos
Abdome/cirurgia , Procedimentos Cirúrgicos em Ginecologia/instrumentação , Laparotomia/instrumentação , Desenho de Equipamento , Feminino , Humanos
13.
Biochem Biophys Res Commun ; 262(1): 211-5, 1999 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-10448094

RESUMO

Smooth muscle cell (SMC) migration plays an important role in restenosis after angioplasty. Myosin phosphorylation is necessary for cell migration. Fasudil is an inhibitor of protein kinases, including myosin light chain kinase and Rho associated kinase, thereby inhibiting myosin phosphorylation, and it has been clinically used to prevent vasospasm following subarachnoid hemorrage. Based on these findings, we examined the anti-migrative action of fasudil. In SMC (SM-3), fasudil (1-100 microM) inhibited SMC migration in a dose-dependent manner (p < 0.001). Fasudil suppressed actin stress fiber formation dose dependently. In rabbit carotid artery, fasudil (10 mg/kg/day) markedly reduced intimal hyperplasia 14 days following balloon injury. Cell kinetic study showed that fasudil did not affect proliferation but enhanced cell loss in the media after injury. We concluded that fasudil reduced neointimal formation after balloon injury through both inhibiting migration and enhancing cell loss of medial SMC.


Assuntos
1-(5-Isoquinolinasulfonil)-2-Metilpiperazina/análogos & derivados , Movimento Celular/efeitos dos fármacos , Músculo Liso Vascular/citologia , Inibidores de Proteínas Quinases , Túnica Íntima/patologia , 1-(5-Isoquinolinasulfonil)-2-Metilpiperazina/farmacologia , Citoesqueleto de Actina/efeitos dos fármacos , Citoesqueleto de Actina/metabolismo , Actinas/metabolismo , Animais , Aorta , Lesões das Artérias Carótidas , Cateterismo , Contagem de Células/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Humanos , Hiperplasia/patologia , Masculino , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/lesões , Músculo Liso Vascular/patologia , Coelhos , Fatores de Tempo , Túnica Íntima/efeitos dos fármacos , Túnica Íntima/lesões , Cicatrização/efeitos dos fármacos
14.
Atherosclerosis ; 132(1): 53-9, 1997 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-9247359

RESUMO

In vascular smooth muscle cells (SMCs), proliferation and migration contribute to lesion formation after arterial injury. In the cell cycle, several cyclin-dependent kinases (cdks) inhibitors are implicated in the regulating of cyclin-cdk activity such as p21Cip1, p16Ink4 and p27Kip1. Although Cip1 inhibits SMC proliferation, its effects on SMC migration are unknown. To test the hypothesis that Cip1 inhibits SMCs migration and proliferation, we transfected the Cip1 gene into a strain of rabbit aortic SMCs (SM3 cells). Both the spreading and the attachment of Cip1-transfected SM3 cells to extracellular matrices (ECMs) were inhibited compared to that of vector-transfected cells. In the modified Boyden's chamber assay the effect of fibronectin on the migratory activity of Cip1-transfected SM3 cells was significantly less than that of vector transfected cells in response to PDGF-BB. These data suggested that Cip1 inhibited both the migration and proliferation of SMC.


Assuntos
Ciclinas/fisiologia , Músculo Liso Vascular/citologia , Actinas/análise , Animais , Aorta , Adesão Celular , Divisão Celular , Movimento Celular , Células Cultivadas , Inibidor de Quinase Dependente de Ciclina p21 , Ciclinas/genética , Citoesqueleto/química , Coelhos , Receptores de Fibronectina/análise , Proteínas Recombinantes de Fusão/fisiologia , Transdução de Sinais , Transfecção , Vinculina/análise
15.
Jpn Circ J ; 60(9): 715-8, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8902592

RESUMO

We report here an 88-year-old male who had been treated with antiarrhythmic drugs because of occasional premature ventricular contraction. The plain chest X-ray film showed a heavily calcified mass within the cardiac silhouette. Transthoracic echocardiography revealed a mobile tumor in the left atrium, which had not prolapsed through the mitral valve into the left ventricle. Transthoracic echocardiography also revealed a tumor in the right atrium. Magnetic resonance imaging of the heart showed that these tumors were attached to the atrial septum by a stalk. The patient had had no history of systemic embolization, syncopal attack or heart failure caused by these tumors. Considering his advanced age, a conservative treatment was agreed upon. At present, he is 93 year-old and in good health. Although the surgical treatment of cardiac tumors has progressed to the point where it represents low risk, even for elderly patients, our present case suggests that some cases of atrial tumors may have a good prognosis even with conservative treatment.


Assuntos
Átrios do Coração/patologia , Neoplasias Cardíacas , Idoso , Idoso de 80 Anos ou mais , Calcinose , Humanos , Masculino
16.
Brain Res ; 720(1-2): 93-100, 1996 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-8782901

RESUMO

beta-Amyloid protein (A beta) is the major component of the senile plaques in Alzheimer's disease (AD), and microglial cells have been shown to be closely associated with these plaques. However, the roles of A beta and microglial cells in pathogenesis of AD remain unclear. Incubation of rat microglial cells with A beta(1-40) caused a significant increase in nitrite, a stable metabolite of nitric oxide (NO), in culture media, while there was no detectable increase in nitrite in astrocyte-rich glial cells or cortical neurons after incubation with A beta(1-40). Nitrite production by microglial cells was also induced by A beta(1-42), but not A beta(25-35). An inhibitor of NO synthase, NG-monomethyl-L-arginine (NMMA), as well as dexamethasone and actinomycin D, dose-dependently inhibited this nitrite production. Among the various cytokines investigated such as interleukin-1, interleukin-6, tumor necrosis factor-alpha and interferon-gamma (IFN-gamma), only IFN-gamma markedly enhanced A beta-dependent nitrite production. Cultured cortical neurons were injured by microglial cells stimulated with A beta in a dose-dependent manner in the presence of IFN-gamma. Neurotoxicity caused by the A beta plus IFN-gamma-stimulated microglial cells was significantly attenuated by NMMA. Thus, although further investigations into the effect of A beta on human microglial cells are needed, it is likely that A beta-induced NO production by microglial cells is one mechanism of the neuronal death in AD.


Assuntos
Peptídeos beta-Amiloides/fisiologia , Peptídeos beta-Amiloides/toxicidade , Microglia/metabolismo , Neurotoxinas/toxicidade , Óxido Nítrico/biossíntese , Animais , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios não Esteroides/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Córtex Cerebral/citologia , Inibidores Enzimáticos/farmacologia , Interferon gama/farmacologia , Microglia/efeitos dos fármacos , Microglia/enzimologia , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico Sintase/biossíntese , Fragmentos de Peptídeos/toxicidade , Ratos , Ratos Sprague-Dawley , Esteroides , Estimulação Química , ômega-N-Metilarginina/farmacologia
18.
Biochem Biophys Res Commun ; 193(2): 540-5, 1993 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-8512556

RESUMO

An enhanced chemiluminescence reaction has been incorporated into an enzyme immunoassay (EIA) for human basic fibroblast growth factor (hbFGF). We developed a new luminol derivative, designated L-012 and a new enhancer, 4-(4-hydroxyphenyl)thiazole. Using these compounds, the detection limit of hbFGF was improved to 0.1 pg/assay, which was 10-20 and 2 times better than the o-phenylenediamine colorimetric and luminol chemiluminescence assays, respectively. The average concentration of bFGF in sera from 25 normal volunteers was 5.9 pg/ml. On the other hand, serum bFGF levels were elevated in renal, lung and brain tumor patients. The data presented here indicate that the serum bFGF level could be a useful diagnostic marker for these tumors. Furthermore, these new compounds could easily be applied to any other EIA that uses horse radish peroxidase to improve sensitivity.


Assuntos
Biomarcadores Tumorais/sangue , Fator 2 de Crescimento de Fibroblastos/sangue , Neoplasias/sangue , Anticorpos Monoclonais , Neoplasias Encefálicas/sangue , Humanos , Técnicas Imunoenzimáticas , Indicadores e Reagentes , Neoplasias Renais/sangue , Neoplasias Hepáticas/sangue , Medições Luminescentes , Luminol/análogos & derivados , Neoplasias Pulmonares/sangue , Valores de Referência , Neoplasias Gástricas/sangue , Neoplasias da Bexiga Urinária/sangue
19.
Glycoconj J ; 9(6): 307-14, 1992 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1305423

RESUMO

The properties of a rat brain glucuronyltransferase, which is presumed to be associated with the biosynthesis of the HNK-1 epitope on sulfoglucuronyl glycolipids, are described. The enzyme required divalent cations for reaction, with maximal activity at 10 mM Mn2+, and exhibited a dual optimum at pH 4-5 and pH 6 depending upon the buffer used, with the highest activity at pH 4.5 in MES buffer. This enzyme strictly recognized the Gal beta 1-4GlcNAc terminal structure, and was highly specific for neolacto (type 2) glycolipids as acceptor. The enzyme was localized specifically in the brain, and was barely detected in other issues, including the thymus, spleen, liver, kidney, lung, and sciatic nerve fibres. Phosphatidylinositol and phosphatidylserine increased the enzymatic reaction 4.4- and 2.3-fold, respectively, whereas phosphatidylcholine slightly decreased the rate.


Assuntos
Encéfalo/enzimologia , Glucuronosiltransferase/análise , Animais , Encéfalo/crescimento & desenvolvimento , Cátions Bivalentes/farmacologia , Glucuronosiltransferase/química , Concentração de Íons de Hidrogênio , Cinética , Fosfolipídeos/farmacologia , Ratos , Ratos Wistar , Especificidade por Substrato
20.
J Biol Chem ; 267(13): 9229-35, 1992 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-1577757

RESUMO

The Gal/GalNAc-specific lectin on rat peritoneal macrophages (macrophage asialoglycoprotein binding protein, M-ASGP-BP) is structurally similar to rat hepatic asialoglycoprotein-binding protein (ASGP-BP) or rat hepatic lectin (RHL) and is highly homologous with the major component of RHL, RHL-1 (Ii, M, Kurata, H., Itoh, N., Yamashina, I., and Kawasaki, T. (1990) J. Biol. Chem. 265, 11295-11298). We found in this study that transfection with a cDNA clone that encodes a single polypeptide, M-ASGP-BP, was sufficient for the expression of an endocytic receptor for asialoorosomucoid (ASOR) on the COS-1 cell surface. The Kuptake value for ASOR for the transfected cells was 12.5 nM, which is similar to that for peritoneal macrophages (23 nM), and the number of ASOR bound on the cell surface was 1-8 x 10(5)/cell, this value being hundreds of times larger than that for peritoneal macrophages. 125I-ASOR bound on the surfaces of the transfected cells was rapidly internalized on incubation at 37 degrees C, and after 90 min of incubation, most of the radioactivity was recovered in acid-soluble degraded products from the medium. These results confirmed that the cDNA cloned in our previous study does in fact encode M-ASGP-BP and also that the single polypeptide chain can form a homooligomeric receptor (probably a hexamer or octamer) exhibiting high affinity for ASOR. The latter property was distinct from that of the hepatic ASGP-BP in that simultaneous transfection of two cloned cDNAs that encode RHL-1 and RHL-2/3 was required to produce an active ASOR receptor (McPhaul, M., and Berg, P. (1986) Proc. Natl. Acad. Sci. U. S. A. 83, 8863-8867). This M-ASGP-BP expression system may serve as a simple model with which to investigate the molecular mechanisms underlying carbohydrate-mediated endocytosis.


Assuntos
Assialoglicoproteínas/metabolismo , Clonagem Molecular , Lectinas/genética , Macrófagos/metabolismo , Receptores Imunológicos/genética , Animais , Receptor de Asialoglicoproteína , Cromatografia Líquida , DNA , Imunofluorescência , Vetores Genéticos , Testes de Precipitina , Ratos , Receptores Imunológicos/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Transfecção
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