Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 47
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Clin Exp Dermatol ; 41(2): 183-9, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25976154

RESUMO

BACKGROUND: Interleukin (IL)-33 is a recently identified cytokine, which is a member of the IL-1 family and binds to a heterodimeric receptor comprising ST2 (suppression of tumorigenicity 2) and IL-1 receptor accessory protein. Serum levels of IL-33 have been reported to be upregulated in various T helper (Th)1/Th17-mediated diseases, such as rheumatoid arthritis and inflammatory bowel disease. IL-33 expression is increased in lesional skin in patients with psoriasis, but serum levels in patients with psoriasis have not yet been studied. AIM: To study serum IL-33 levels in patients with psoriasis, a Th1/Th17-mediated skin disease, before and after anti-tumour necrosis factor (TNF)-α therapy. METHODS: Serum IL-33 levels were measured in patients with psoriasis vulgaris (PV), psoriatic arthritis (PsA) or pustular psoriasis (PP), and compared with those of healthy controls. Associations between serum IL-33 levels and serum TNF-α, IL-6, vascular endothelial growth factor and C-reactive protein levels were also studied. In addition, the effect of IL-33 stimulation on IL-6, IL-8, TNF-α and VEGF secretion by human keratinocyte was analysed. RESULTS: Serum IL-33 levels in patients with PV, PsA and PP were significantly higher than those in healthy controls. Serum IL-33 levels correlated with serum TNF-α levels in patients with psoriasis, and decreased after anti-TNF-α therapy. IL-33 stimulated IL-6 and IL-8 secretion by human keratinocytes. CONCLUSIONS: These results suggest that serum IL-33 levels generally reflect increased inflammation in patients with psoriasis.


Assuntos
Interleucina-33/metabolismo , Psoríase/metabolismo , Adulto , Análise de Variância , Proteína C-Reativa/metabolismo , Estudos de Casos e Controles , Citocinas/metabolismo , Feminino , Humanos , Interleucinas/metabolismo , Queratinócitos/metabolismo , Masculino , Pessoa de Meia-Idade , Psoríase/sangue , Fator de Necrose Tumoral alfa/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo
3.
Dis Esophagus ; 21(4): 288-97, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18477249

RESUMO

Radiotherapy plays a key role in the control of tumor growth in esophageal cancer patients. To identify the patients who will benefit most from radiation therapy, it is important to know the genes that are involved in the radiosensitivity of esophageal cancer cells. Hence, we examined the global gene expression in radiosensitive and radioresistant esophageal squamous cell carcinoma cell lines. Radiosensitivities of 13 esophageal cancer cell lines were measured. RNA was extracted from each esophageal cancer cell line and a normal esophageal epithelial cell line, and the global gene expression profiles were analyzed using a 34 594-spot oligonucleotide microarray. In the clonogenic assay, one cell line (TE-11) was identified to be highly sensitive to radiation, while the other cell lines were found to be relatively radioresistant. We identified 71 candidate genes that were differentially expressed in TE-11 by microarray analysis. The up-regulated genes included CABPR, FABP5, DSC2, GPX2, NME, CBR3, DOCK8, and ABCC5, while the down-regulated genes included RPA1, LDOC1, NDN, and SKP1A. Our investigation provided comprehensive information on genes related to radiosensitivity of esophageal cancer cells; this information can serve as a basis for further functional studies.


Assuntos
Carcinoma de Células Escamosas/genética , Neoplasias Esofágicas/genética , Tolerância a Radiação/genética , Carcinoma de Células Escamosas/radioterapia , Linhagem Celular Tumoral , Neoplasias Esofágicas/radioterapia , Perfilação da Expressão Gênica , Humanos , Microscopia Confocal , Análise de Sequência com Séries de Oligonucleotídeos , Radioterapia
4.
Dis Esophagus ; 21(1): 15-20, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18197934

RESUMO

5-Fluorouracil (5-FU) is a key drug in the treatment of esophageal squamous cell carcinoma (ESCC). Gene expression of 5-FU metabolic enzymes such as thymidylate synthase (TS), thymidine phosphorylase (TP), dihydropyrimidine dehydrogenase (DPD) and orotate phosphoribosyl transferase (OPRT), has recently been investigated in order to predict the 5-FU sensitivity of several cancers. We examined the relationship between such gene expression and 5-FU sensitivity in 25 ESCC cell lines. TS, DPD, TP and OPRT mRNA levels were assessed by real-time polymerase chain reaction. The 50% inhibitory concentrations (IC50) of 5-FU in 25 ESCC cell lines were determined by cell proliferation assay. IC50 values for 5-FU ranged from 1.00 to 39.81 micromol/L. There were significant positive correlations between IC50 and TS mRNA expression (R(2) = 0.5781, P < 0.0001) and DPD mRNA expression (R(2) = 0.3573, P = 0.0016). There were no correlations between IC50 and TP or OPRT mRNA expression. TS and DPD mRNA expression levels may be useful indicators in predicting the anti-tumor activity of 5-FU in ESCC.


Assuntos
Antimetabólitos Antineoplásicos/farmacologia , Di-Hidrouracila Desidrogenase (NADP)/metabolismo , Fluoruracila/farmacologia , Orotato Fosforribosiltransferase/metabolismo , Timidina Fosforilase/metabolismo , Timidilato Sintase/metabolismo , Carcinoma/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Di-Hidrouracila Desidrogenase (NADP)/genética , Neoplasias Esofágicas/metabolismo , Expressão Gênica/efeitos dos fármacos , Humanos , Concentração Inibidora 50 , Orotato Fosforribosiltransferase/genética , RNA Mensageiro/efeitos dos fármacos , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Timidina Fosforilase/genética , Timidilato Sintase/genética
5.
Dis Esophagus ; 19(6): 454-8, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-17069588

RESUMO

NDRG1 (N-myc downstream regulated gene-1) was reported to be necessary for p53-mediated apoptosis and to be regulated by PTEN (phosphatase and tensin homolog). In several cancers, it was suggested to be a tumor suppressor gene. Its significance in esophageal squamous cell carcinoma (ESCC) has not been studied. The objective of this study was to clarify the relation between clinicopathological and biologic factors in esophageal carcinoma and to determine the prognostic significance of the expression of NDRG1. Expression of NDRG1 mRNA was quantified by real-time reverse transcription polymerase chain reaction using a Lightcycler in 47 esophageal ESCC specimens. The data were analyzed with reference to clinicopathological factors. Among the esophageal cancer tissues, NDRG1 mRNA expression was significantly lower in tumors of more advanced pathological stage (0-I vs. II-IV; P = 0.0027) and local tumor invasion (T1-2 vs. T3-4; P = 0.0136). Patients who had low NDRG1 mRNA expression had a significantly shorter survival after surgery compared with patients who had high NDRG1 mRNA expression (log-rank test, P = 0.0478). Impaired NDRG1 expression may lead to more aggressive invasion of ESCC.


Assuntos
Carcinoma de Células Escamosas/metabolismo , Proteínas de Ciclo Celular/metabolismo , Neoplasias Esofágicas/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patologia , Proteínas de Ciclo Celular/genética , Progressão da Doença , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/patologia , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Estadiamento de Neoplasias , Prognóstico , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sobrevida , Regulação para Cima/fisiologia
6.
Eur Surg Res ; 34(4): 306-12, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12145557

RESUMO

We studied the effect of hyperthermia pretreatment on subsequent small intestinal ischemia and reperfusion (I/R) injury in the rat. Systemic hyperthermia has been reported to induce heat shock proteins (HSPs) in several organs [1-6]. We examined the expression of HSP72 in the small intestinal mucosa using Western blotting and immunohistochemistry. We monitored energy metabolism using magnetic resonance spectroscopy continuously during a 60-min ischemia and the following 120 min of reperfusion. Expression of HSP72 in the small intestine was significantly increased at 6-8 h after hyperthermia. Intestinal ischemia was induced by clamping the superior mesenteric artery. Heating of the rat conferred substantial resistance to the I/R injury. In the untreated rats, beta-ATP decreased during ischemia (37.1 +/- 15.5% of the pre-ischemic value) and recovered on reperfusion, but reached only approximately 50% of the pre-ischemic value after 120 min of reperfusion. However, beta-ATP in the pretreated rats was maintained during ischemia at significantly higher levels and on reperfusion reached approximately 80% of the pre-ischemic value. These results indicate that hyperthermia protects the rat intestine from the I/R injury by unknown mechanisms which may include the induction of HSPs.


Assuntos
Trifosfato de Adenosina/metabolismo , Hipertermia Induzida , Intestino Delgado/metabolismo , Traumatismo por Reperfusão/patologia , Traumatismo por Reperfusão/terapia , Animais , Metabolismo Energético , Proteínas de Choque Térmico HSP72 , Proteínas de Choque Térmico/metabolismo , Intestino Delgado/patologia , Espectroscopia de Ressonância Magnética , Masculino , Isótopos de Fósforo , Ratos , Ratos Wistar , Traumatismo por Reperfusão/metabolismo
8.
Int J Cancer ; 95(2): 92-5, 2001 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-11241318

RESUMO

Survivin, a new member of the inhibitor-of-apoptosis (IAP) family, has been reported to be expressed in many cancers but not in differentiated normal tissue. Its expression in esophageal cancer, however, has not been reported. We investigated 51 esophageal cancers and their adjacent normal epithelial tissues for mRNA expression of survivin by RT-PCR. The survivin expression in esophageal cancer tissue was significantly higher than that in normal esophageal tissue (0.211 +/- 0.226 vs. 0.057 +/- 0.135, p < 0.0001). pN4 tumors had significantly higher survivin expression than the pN0-3 tumors (p = 0.0093). Fourteen patients with advanced esophageal cancer had received chemotherapy prior to surgery. The survivin expression in the cancer tissue in patients who achieved a partial response (PR) was significantly lower than that in patients with no change (NC) and in patients with progressive disease (PD; 0.099 +/- 0.134 vs. 0.320 +/- 0.222, p = 0.0434). The median survival for patients with high survivin expression (9.0 months) was less than that for patients with low survivin group expression (30.0 months, p = 0.0023). Survivin expression was one of the significant predictors of survival on univariate analysis (hazard ratio 2.471; 95% confidence interval 1.104-5.533). The results suggest that survivin expression may provide prognostic information in patients with esophageal cancer.


Assuntos
Neoplasias Esofágicas/tratamento farmacológico , Neoplasias Esofágicas/metabolismo , Neoplasias Esofágicas/mortalidade , Proteínas Associadas aos Microtúbulos , Biossíntese de Proteínas , Fatores Etários , Idoso , Antimetabólitos Antineoplásicos/uso terapêutico , Antineoplásicos/uso terapêutico , Cisplatino/uso terapêutico , Neoplasias Esofágicas/diagnóstico , Esôfago/metabolismo , Feminino , Fluoruracila/uso terapêutico , Seguimentos , Humanos , Proteínas Inibidoras de Apoptose , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Proteínas de Neoplasias , Prognóstico , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores Sexuais , Survivina , Fatores de Tempo , Resultado do Tratamento
9.
J Cereb Blood Flow Metab ; 20(5): 829-33, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10826533

RESUMO

Thioredoxin is a small, multifunctional protein with a redox-active disulfide/dithiol in the active site. Thioredoxin plays several important biologic roles both in intracellular and extracellular compartments with its redox-regulating and reactive oxygen intermediates scavenging activities. We assayed the seizure response and the excitotoxic hippocampal injury in thioredoxin transgenic and wild-type C57BL/6 mice. Seizure score after kainic acid treatment was significantly lower in thioredoxin transgenic mice. Seven days after kainic acid administration, the damage in the hippocampal CA1 and CA3 regions was significantly attenuated in thioredoxin transgenic mice. Thioredoxin and redox regulation play an important role in excitotoxic brain damage.


Assuntos
Hipocampo/efeitos dos fármacos , Hipocampo/patologia , Ácido Caínico/farmacologia , Neurotoxinas/farmacologia , Tiorredoxinas/farmacologia , Animais , Sequestradores de Radicais Livres/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos/genética , Neurônios/efeitos dos fármacos , Neurônios/patologia , Oxirredução/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Tiorredoxinas/genética
10.
Proc Natl Acad Sci U S A ; 96(11): 6054-9, 1999 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-10339540

RESUMO

A sensitive assay using biotinylated ubiquitin revealed extensive ubiquitination of the large subunit of RNA polymerase II during incubations of transcription reactions in vitro. Phosphorylation of the repetitive carboxyl-terminal domain of the large subunit was a signal for ubiquitination. Specific inhibitors of cyclin-dependent kinase (cdk)-type kinases suppress the ubiquitination reaction. These kinases are components of transcription factors and have been shown to phosphorylate the carboxyl-terminal domain. In both regulation of transcription and DNA repair, phosphorylation of the repetitive carboxyl-terminal domain by kinases might signal degradation of the polymerase.


Assuntos
RNA Polimerase II/química , RNA Polimerase II/metabolismo , Ubiquitinas/metabolismo , Amanitinas/farmacologia , Núcleo Celular/metabolismo , Quinases Ciclina-Dependentes/antagonistas & inibidores , Cisteína Endopeptidases/metabolismo , Inibidores Enzimáticos/farmacologia , Glutationa Transferase/metabolismo , Células HeLa , Humanos , Cinética , Substâncias Macromoleculares , Complexos Multienzimáticos/metabolismo , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/metabolismo , Fosforilação , Complexo de Endopeptidases do Proteassoma , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/metabolismo , Moldes Genéticos , Transcrição Gênica
11.
Proc Natl Acad Sci U S A ; 96(7): 4131-6, 1999 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-10097175

RESUMO

Thioredoxin (TRX) plays important biological roles both in intra- and extracellular compartments, including in regulation of various intracellular molecules via thiol redox control. We produced TRX overexpressing mice and confirmed that there were no anatomical and physiological differences between wild-type (WT) mice and TRX transgenic (Tg) mice. In the present study we subjected mice to focal brain ischemia to shed light on the role of TRX in brain ischemic injury. At 24 hr after middle cerebral artery occlusion, infarct areas and volume were significantly smaller in Tg mice than in WT mice. Moreover neurological deficit was ameliorated in Tg mice compared with WT mice. Protein carbonyl content, a marker of cellular protein oxidation, in Tg mice showed less increase than did that of WT mice after the ischemic insult. Furthermore, c-fos expression in Tg mice was stronger than in WT mice 1 hr after ischemia. Our results suggest that transgene expression of TRX decreased ischemic neuronal injury and that TRX and the redox state modified by TRX play a crucial role in brain damage during stroke.


Assuntos
Infarto Cerebral/prevenção & controle , Regulação da Expressão Gênica , Ataque Isquêmico Transitório/patologia , Tiorredoxinas/metabolismo , Animais , Antioxidantes/metabolismo , Encéfalo/irrigação sanguínea , Encéfalo/patologia , Encéfalo/fisiopatologia , Infarto Cerebral/genética , Infarto Cerebral/patologia , Circulação Cerebrovascular , Glutationa Peroxidase/genética , Humanos , Ataque Isquêmico Transitório/genética , Ataque Isquêmico Transitório/prevenção & controle , Masculino , Camundongos , Camundongos Transgênicos , Proteínas Proto-Oncogênicas c-bcl-2/genética , Superóxido Dismutase/genética
12.
Kyobu Geka ; 50(10): 838-43, 1997 Sep.
Artigo em Japonês | MEDLINE | ID: mdl-9301178

RESUMO

The thoracoscopic surgery for two benign esophageal diseases, esophageal leiomyoma and esophageal diverticulum, were successfully performed. Case 1 was a 37-year-old female with esophageal leiomyoma that was located at 30 cm from the incisor of the left anterior esophagus. The tumor was enucleated under the thoracoscopy, combined mini-thoracotomy for 3 cm in length. It was useful enough to rotate the left side to the right with two slings traction for better visualization of lesion site. After resection, the proper muscle layer of the esophagus was closed. Case 2 was a 70-year-old male, who complained of dysphagia because of esophageal diverticulum. It was 8 cm in size and located at 28 cm from the incisor of the right wall of the esophagus. It was also resected under the thoracoscopy, combined mini-thoracotomy for 3 cm in length. Intraluminal esophagoscope was useful to dissect safely and confirm the intralumen of the diverticulum. Its neck was divided parallel to the longitudinal axis of the esophagus by two endo-staplers. And then, the muscle layer was closed. It was suggested that esophageal leiomyoma and esophageal diverticulum were suitable for thoracoscopic surgery.


Assuntos
Divertículo Esofágico/cirurgia , Endoscopia/métodos , Neoplasias Esofágicas/cirurgia , Leiomioma/cirurgia , Adulto , Idoso , Feminino , Humanos , Masculino , Toracoscopia
13.
J Immunol ; 158(7): 3108-17, 1997 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-9120263

RESUMO

Thiol compounds, such as L-cysteine and glutathione (GSH), play crucial roles in the regulation of lymphocyte proliferation. In this study, we analyzed the effect of L-cystine and GSH depletion on lymphocyte survival and investigated the regulatory roles of adult T cell leukemia (ATL)-derived factor (ADF)/human thioredoxin (hTRX) in relation to these low m.w. thiols. MT-1, MT-2, and Jurkat cells underwent apoptosis when cultured in the L-cystine- and GSH-free medium within 18 to 24 h. Dichlorofluorescin oxidation assay indicated that the apoptosis in MT-1 and MT-2 cells was preceded by an increase in the level of intracellular hydrogen peroxide (H2O2). The addition of catalase and recombinant ADF/hTRX (rADF) partially blocked the apoptosis in a dose-dependent manner. rADF has been also shown to enhance the internalization of L-cystine into MT-2 cells in a dose-dependent manner, whereas oxidized rADF or mutated rADF that has no insulin-reducing activity failed to do so. Furthermore, culture in the L-cystine- and GSH-free medium lowered the cellular GSH content of PHA blasts, which was restored dose-dependently by rADF. These data suggest that the inability to neutralize oxidative stress results in the apoptosis of lymphoid cells under L-cystine- and GSH-depleted conditions. The protective effects of rADF may be explained by direct scavenging action on H2O2 (catalase-like activity) or by indirect neutralizing effects on the pro-oxidant status through enhancing the L-cystine internalization and elevating the intracellular GSH content.


Assuntos
Apoptose/efeitos dos fármacos , Cistina/farmacologia , Citocinas/farmacologia , Glutationa/farmacologia , Linfócitos/efeitos dos fármacos , Proteínas de Neoplasias/farmacologia , Oxidantes/farmacologia , Compostos de Sulfidrila/farmacologia , Tiorredoxinas/farmacologia , Catalase/farmacologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Meios de Cultura , Cistina/deficiência , Citocinas/genética , Glutationa/deficiência , Humanos , Peróxido de Hidrogênio/metabolismo , Linfócitos/metabolismo , Peso Molecular , Proteínas de Neoplasias/genética , Oxirredução , Proteínas Recombinantes/farmacologia , Compostos de Sulfidrila/metabolismo
14.
J Clin Lab Anal ; 10(5): 257-61, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8887004

RESUMO

Four different monoclonal antibodies against recombinant adult T-cell leukemia-derived factor (ADF), identical to thioredoxin, were established and used for the determination of ADF concentration in serum. Using two of the monoclonal antibodies, we developed a two-step enzyme-linked immunosorbent assay (ELISA) for ADF. This ELISA showed a highly specific reactivity on ADF with no cross-reactivity to several proteins with homologue sequence on the active center. The detection limit of the assay was 2.0 ng/ml (mean +/- 2 SD). The intra- and interassay coefficients of variation (CV) were 0.81-3.74% (n = 8) and 4.78-6.97% (n = 7), respectively. The normal value of ADF mean concentration from 145 healthy donors was 40.8 ng/ml.


Assuntos
Citocinas/sangue , Proteínas de Neoplasias/sangue , Adulto , Animais , Anticorpos Monoclonais/imunologia , Reações Cruzadas , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Pessoa de Meia-Idade , Valores de Referência
15.
Thorax ; 50(4): 387-91, 1995 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7785012

RESUMO

BACKGROUND: Active oxygen species are thought to play a part in ischaemia reperfusion injury. The ability of a novel agent, human thioredoxin (hTRX), to attenuate lung damage has been examined in a rat model of ischaemia reperfusion injury. METHODS: Twenty eight animals were studied. At thoracotomy the left main bronchus and the left main pulmonary artery were clamped for 75 minutes and the lung was then reperfused for 20 minutes. Phosphate buffered saline was administered intravenously to nine control animals and hTRX (30 micrograms/g body weight) was given intravenously to another group of nine animals. Two experiments were carried out. The first (Exp 1) was a time matched pair experiment (five treated, five controls), and the second (Exp 2) was performed under controlled conditions (four treated, four controls; temperature 25 degrees C, humidity 65%). In another 10 nonischaemic rats and those in Exp 1 biochemical measurements of lipid peroxide, superoxide dismutase, and glutathione peroxide levels were performed. RESULTS: In both experiments rats perfused with hTRX survived longer than controls. In Exp 1 the arterial oxygen tension (PaO2) on air in the hTRX group was higher at 20 minutes than at one minute after reperfusion. In Exp 2 PaO2 at 20 minutes was higher in the hTRX group than in the controls. Lipid peroxide, superoxide dismutase, and glutathione peroxide levels in the control group were higher than in the hTRX group and in the non-ischaemic groups. Histological examination showed less thickening and oedema of the alveolar walls in the hTRX group than in controls. CONCLUSIONS: These results suggest that hTRX is effective as a radical scavenger and can limit the extent of ischaemia reperfusion injury of the lungs of experimental animals.


Assuntos
Sequestradores de Radicais Livres/uso terapêutico , Pulmão/efeitos dos fármacos , Traumatismo por Reperfusão/tratamento farmacológico , Tiorredoxinas/uso terapêutico , Animais , Glutationa Peroxidase/análise , Humanos , Peróxidos Lipídicos/análise , Pulmão/química , Masculino , Oxigênio/sangue , Ratos , Ratos Wistar , Traumatismo por Reperfusão/sangue , Superóxido Dismutase/análise
16.
Biotechnol Bioeng ; 44(10): 1255-60, 1994 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-18618552

RESUMO

Synechococus sp. strain Miami BG 043511 exhibits very high H(2) photoproduction from water, but the H(2) photoproduction capability is lost rapidly with the age of the batch culture. The decreases of the capability coincides with the decrease of cellular glucose (glycogen) content. However, H(2) photoproduction capability can be restored by the addition of organic substrates. Among 40 organic compounds tested, carbohydrates such as glucose, fructose, maltose, and sucrose were effective electron donors. Among organic acids tested, only pyruvate was an effective electron donor. Among alcohols tested, glycerol was a good electron donor. These results demonstrate that this unicellular cyanobacterium exhibits a wide substrate specificity for H(2) photoproduction but has a different substrate specificity compared to photosynthetic bacteria. The maximum rates of H(2) photoproduction from a 6-day-old batch culture with 25 mmol of pyruvate, glucose, maltose, sucrose, fructose, and glycerol were 1.11, 0.62, 0.50, 0.47, 0.30, and 0.39 micromoles per mg cell dry weight per hour respectively. Therefore, this cyanobacterium strain may have a potential significance in removing organic materials from the wastewater and simultaneously transforming them to H(2) gas, a pollution free energy. The activity of nitrogenase, which catalyzes hydrogen production, completely disappeared when intracellular glucose (glycogen) was used up, but it could be restored by the addition of organic substrates such as glucose and pyruvate. (c) 1994 John Wiley & Sons, Inc.

17.
Biotechnol Bioeng ; 44(7): 854-8, 1994 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-18618853

RESUMO

The capability of hydrogen photoproduction under high cell density conditions was examined using synchronously grown cells of nitrogen-fixing Synechococcus sp. Miami BG 043511. Optimum hydrogen yield was obtained when vessels (25 ml) contained 0.2 to 0.3 mg chlorophyll (a) in 3-mL cell suspension. During a 24-h incubation period, an initial phase of hydrogen and carbon dioxide production and a subsequent phase of carbon dioxide uptake and oxygen accumulated as major products after 24 h. after the initial 24-h. After the initial 24-h incubation, as high as 7.4 and 3.7 L (at standard condition) of hydrogen and oxygen, respectively, accumulated in vessels with 22-ml gas phase. This indicated that the pressure in the flask increased to 1.5 atmosphere. Energy conversion efficiency based on photosynthetically active radiation (25 W/m(2)) was about 2.6%. However, increased pressure somehow reduced the duration of hydrogen production. Duration of hydrogen and oxygen production was prolonged by periodical (24-h interval) gas replacement during incubation. (c) 1994 John Wiley & Sons, Inc.

18.
Immunol Lett ; 41(2-3): 155-61, 1994 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8002031

RESUMO

Adult T-cell leukemia (ATL)-derived factor (ADF), originally defined as an inducer of interleukin-2 receptor/alpha-chain (IL-2R/p55) of human T-lymphotropic virus type I (HTLV-I) positive T cells, is a human homologue of redox-active coenzyme thioredoxin (Trx) of Escherichia coli. In this study, an enzymatic assay system based on the dithiol-dependent insulin-reducing activity of ADF/Trx was established (insulin-reducing assay) to determine the amount of ADF/Trx in human serum using NADPH and Trx reductase purified from human placenta. Insulin-reducing activity was detected in all of the serum samples from healthy volunteers (n = 30) screened by this assay, with a mean +/- SD of 10.9 +/- 2.4 U/l. This mean value corresponds with the concentration of 223 ng recombinant ADF/Trx (rADF/Trx)/ml. Human serum is known to contain several redox-active proteins with ADF/Trx motifs. To differentiate the contribution of these proteins and ADF/Trx to the insulin-reducing activity, the anti-rADF/Trx monoclonal antibody (mAb)-conjugated affinity column-depleted sera obtained from an identical source was used for analysis. The affinity column-depleted sera demonstrated a loss of over 99% of the original activity, while control column depleted sera lost less than 4%. Furthermore, the amount of affinity-purified ADF/Trx molecules eluted from the same column almost corresponded with the amount estimated by the insulin-reducing activity.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Citocinas , Proteínas de Neoplasias/sangue , Tiorredoxinas/sangue , Adulto , Sequência de Aminoácidos , Anticorpos Monoclonais , Cromatografia de Afinidade , Feminino , Humanos , Immunoblotting , Insulina/química , Masculino , Dados de Sequência Molecular , Oxirredução , Tiorredoxina Dissulfeto Redutase
20.
Respiration ; 61(2): 99-104, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-8008996

RESUMO

The formation of reactive oxygen species (ROS) is a major factor responsible for reperfusion injury in lungs. Adult T cell leukemia derived factor (ADF), a polypeptide made of 104 amino acids, is induced by a variety of stresses including X-ray, ultraviolet, H2O2, and mitogen. ADF has a reducing activity, which catalyzes the proton transfer between thiol-radical of cystein-containing proteins. Furthermore, ADF has a protective activity of ROS which are formed by xanthine oxidase and other alternative pathways in vitro. Using a rat in vivo model of lung ischemia, we examined the protective effect of recombinant human ADF (rhADF) against ischemia reperfusion injury of the lung. Ischemia, lasting for 75 min, was induced in the left lung of rats at 23 degrees C. The lung was then reperfused. These animals were divided into two groups: group 1 (n = 6, treatment with normal saline) and group 2 (n = 6, treatment with 28 micrograms/g of rhADF). One minute after the beginning of reperfusion, arterial oxygen tension (PaO2) decreased significantly in both groups (p < 0.01), without any significant intergroup difference (55.5 +/- 9.8, 49.8 +/- 8.6 mm Hg, respectively). Twenty minutes after reperfusion, PaO2 was significantly higher (p < 0.05) in group 2 (113.0 +/- 8.1 mm Hg) than in group 1 (72.3 +/- 13.6 mm Hg). The wet/dry weight ratio was significantly higher in group 1 (7.31 +/- 0.54) than in group 2 (5.82 +/- 0.36). Histologically, lung injury tended to be milder in group 2 than in group 1. These results suggest that rhADF has a protective effect against ischemia reperfusion injury of the rat lung.


Assuntos
Citocinas , Pneumopatias/patologia , Proteínas de Neoplasias/farmacologia , Traumatismo por Reperfusão/patologia , Animais , Dióxido de Carbono/sangue , Pulmão/patologia , Pneumopatias/sangue , Tamanho do Órgão , Oxigênio/sangue , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Proteínas Recombinantes/farmacologia , Traumatismo por Reperfusão/sangue , Traumatismo por Reperfusão/fisiopatologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...