Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.106
Filtrar
1.
Cell Mol Biol (Noisy-le-grand) ; 62(12): 74-78, 2016 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-27894404

RESUMO

Streptozotocin (STZ), a naturally occurring chemical, is toxic to the various kinds of cells such as insulin-producing beta cells. However, the beneficial effect of STZ on neuronal cells such as neurite outgrowth-inducing activity has been unknown. In this study, we examined the effect of STZ on neurite outgrowth in mouse neuronal Neuro2a cells. STZ (0.01 mM~5 mM) exerted remarkable neurite outgrowth-inducing activity in Neuro2a cells in a concentration dependent manner. STZ also had the same neurite outgrowth-inducing activity as that of retinoic acid (RA), which is well known neurite outgrowth inducer. As with the result of RA treatment, STZ administration increased MAP2-positive cells. The MAP2-positive cells reflect neurite outgrowth-induced cells. STZ (0.01 mM~5 mM) did not induce cell death, but significantly decreased cell proliferation. The serine/threonine kinase Akt, a downstream target of phosphatidylinositol-3 kinase (PI3K), was transiently phosphorylated at Ser473 and at Thr303 by STZ (5 mM) administration. Glycogen synthase kinase 3ß (GSK3ß), which has been reported to be inactivated by Akt, was also transiently phosphorylated at Ser9 by STZ (5 mM) administration. In addition, a blocker of PI3K, LY294002 (10 µM), significantly attenuated STZ-induced neurite outgrowth. These results suggest that STZ induces neurite outgrowth via activation of PI3K-Akt signaling pathway and GSK3ß inhibition.


Assuntos
Glicogênio Sintase Quinase 3 beta/metabolismo , Crescimento Neuronal/efeitos dos fármacos , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos , Estreptozocina/farmacologia , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cromonas/farmacologia , Immunoblotting , Camundongos , Morfolinas/farmacologia , Neurônios/citologia , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase , Fosforilação/efeitos dos fármacos
2.
Tissue Antigens ; 83(1): 45-8, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24355007

RESUMO

A genetic polymorphism of the newly discovered interferon-λ 4 (IFNL4) gene was associated with hepatitis C virus (HCV) clearance in individuals of African ancestry. To assess whether a dinucleotide variant of IFNL4 (ss469415590) also affected treatment outcome of antiviral therapy in Japan, we genotyped 213 patients with chronic genotype 1 HCV infection and 176 healthy subjects. The ΔG allele was associated with treatment failure [odds ratio (OR) 4.73, P = 0.019], as was the IFL3 rs8099917 single nucleotide polymorphism (SNP) (OR 5.06, P = 0.068). The correlation between ss469415590 and rs8099917 was high (r(2) = 0.92, D' = 0.98). Multivariate analysis revealed that the rs8099917 SNP was independently associated with treatment failure (OR 5.28, P = 0.009). Therefore, ss469415590 may be another predictive marker of antiviral therapy outcome in the Japanese population.


Assuntos
Hepatite C Crônica/genética , Hepatite C Crônica/terapia , Interferon-alfa/uso terapêutico , Interleucinas/genética , Ribavirina/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Genótipo , Hepatite C Crônica/diagnóstico , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Polimorfismo Genético , Resultado do Tratamento , Adulto Jovem
3.
J Nutr Health Aging ; 26(6): 590-597, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35718868

RESUMO

OBJECTIVES: To investigate the predictive value of the BIA-derived phase angle with respect to the functional prognosis and baseline sarcopenia in patients undergoing post-stroke rehabilitation. DESIGN: Retrospective cohort study. SETTING AND PARTICIPANTS: Overall, 577 Japanese patients admitted to a post-acute care hospital from 2016 to 2020 were recruited. MEASUREMENTS: Body composition analysis, which included BIA-derived phase angle and skeletal muscle mass, was performed using bioelectrical impedance analysis (BIA). Study outcomes included physical function assessed using the Functional Independence Measure (FIM-motor) and the level of dysphagia assessed using the Food Intake LEVEL Scale (FILS). Sarcopenia was defined as the loss of skeletal muscle mass and decreased muscle strength. Receiver operating characteristic curves were used to calculate the optimal cutoff value of BIA-derived phase angle to diagnose sarcopenia. Multivariate analyses were used to determine whether the BIA-derived phase angle at admission was associated with outcomes at discharge and baseline sarcopenia. RESULTS: After enrollment, 499 patients (mean age: 74.0 ± 13.1 years; 52.0% men) were examined. The median FIM-motor and FILS scores at admission were 47 (20-69) and 8 (7-10), respectively. Sarcopenia was observed in 43.2% of patients. After adjusting for potential confounders, BIA-derived phase angle was positively associated with FIM-motor scores at discharge (ß = 0.134, P < 0.001), FIM-motor score gain (ß = 2.504, P < 0.001), and FILS scores at discharge (ß = 0.120, P = 0.039). BIA-derived phase angle was negatively associated with the sarcopenia diagnosis at baseline (odds ratio = -0.409, P < 0.001); its cutoff value was 4.76° (sensitivity 0.800, specificity 0.790, P < 0.001) for sarcopenia diagnosis in men and 4.11° (sensitivity 0.735, specificity 0.829, P < 0.001) in women. CONCLUSION: BIA-derived phase angle was positively associated with the recovery of physical function and dysphagia level and negatively associated with baseline sarcopenia in patients undergoing post-stroke rehabilitation. The BIA-derived phase angle cutoff for sarcopenia diagnosis was 4.76° for men and 4.11° for women.


Assuntos
Transtornos de Deglutição , Sarcopenia , Reabilitação do Acidente Vascular Cerebral , Atividades Cotidianas , Idoso , Idoso de 80 Anos ou mais , Transtornos de Deglutição/etiologia , Transtornos de Deglutição/reabilitação , Feminino , Humanos , Masculino , Estudos Retrospectivos , Sarcopenia/diagnóstico
4.
Skin Health Dis ; 2(1): e78, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35665216

RESUMO

Background: The activation of melanocortin 1 receptor (MC1R) on melanocytes stimulates the production of eumelanin. A tridecapeptide α melanocyte-stimulating hormone (αMSH) is known to induce skin pigmentation. Objectives: We characterised the properties of a novel oral MC1R agonist dersimelagon (MT-7117) with respect to its specific binding to MC1R, downstream signalling and eumelanin production in experimental models. Methods: The competitive binding and production of intracellular cyclic adenosine 3', 5'-monophosphate in cells expressing recombinant melanocortin receptors were examined. A mouse melanoma cell line B16F1 was used for the evaluation of in vitro melanin production. The in vitro activity of MT-7117 was determined with αMSH and [Nle4, D-Phe7]-αMSH (NDP-αMSH) as reference comparators. The change of coat colour and skin pigmentation were evaluated after repeat administration of MT-7117 by oral gavage to C57BL/6J-Ay/+ mice and cynomolgus monkeys, respectively. Results: MT-7117 showed the highest affinity for human MC1R compared to the other melanocortin receptors evaluated and agonistic activity for human, cynomolgus monkey and mouse MC1R, with EC50 values in the nanomolar range. In B16F1 cells, MT-7117 increased melanin production in a concentration-dependent manner. In vivo, MT-7117 (≥0.3 mg/kg/day p.o.) significantly induced coat colour darkening in mice. MT-7117 (≥1 mg/kg/day p.o.) induced significant skin pigmentation in monkeys and complete reversibility was observed after cessation of its administration. Conclusions: MT-7117 is a novel oral MC1R agonist that induces melanogenesis in vitro and in vivo, suggesting its potential application for the prevention of phototoxic reactions in patients with photodermatoses, such as erythropoietic protoporphyria and X-linked protoporphyria.

5.
Nat Med ; 2(1): 90-3, 1996 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8564850

RESUMO

Synthetic vascular prostheses are foreign bodies, so that blood coagulation can occur on their luminal surfaces, causing graft occlusion very frequently in prostheses of small diameter. A vascular prosthesis needs angiogenesis for endothelialization of the luminal surface, as endothelial cells have natural and permanent antithrombogenic properties. To induce capillary growth into the graft, we developed a method of transplanting bone marrow cells, which are primitive, strong enough to survive, and create blood cells, resulting in the inducement of capillary growth. In an animal experiment, marrow cells were infiltrated into the walls of long-fibril expanded polytetrafluoroethylene (ePTFE) vascular grafts. The grafts were implanted in the abdominal aortic position of 24 dogs autologously. Marrow cells survived and continued exogenous hemopoiesis for up to six months and were immunohistochemically reactive to basic fibroblast growth factor (bFGF). All the grafts older than three weeks had complete endothelialization and maintained their patency. Twenty grafts without bone marrow were implanted as controls. Endothelialization was present at anastomotic sites, but other areas were covered with fresh thrombi. Four out of seven control grafts were patent with endothelial cell lining at six months, but three were occluded and one of the four grafts was still covered with a thrombus layer. Bone marrow with its unique native properties produced autocrine angiogenicity in the graft.


Assuntos
Prótese Vascular , Transplante de Medula Óssea , Sobrevivência de Enxerto , Neovascularização Fisiológica , Animais , Aorta Abdominal , Materiais Biocompatíveis , Transplante de Medula Óssea/fisiologia , Capilares/crescimento & desenvolvimento , Cães , Endotélio Vascular/crescimento & desenvolvimento , Fator 2 de Crescimento de Fibroblastos/análise , Fator 2 de Crescimento de Fibroblastos/biossíntese , Hematopoese , Imuno-Histoquímica , Politetrafluoretileno , Fatores de Tempo , Transplante Autólogo
6.
BJS Open ; 5(5)2021 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-34518870

RESUMO

BACKGROUND: Studies evaluating the outcomes after laparoscopic resections of transverse colon cancers are scant. This manuscript aimed to compare surgical and oncological outcomes after laparoscopic (Lap) and open procedures for transverse colon carcinomas. METHODS: All consecutive patients who underwent resection for a cancer located in the transverse colon between 2003 and 2019 were reviewed. Patients were categorized according to the surgical approach (Lap versus open) and groups were compared. Outcome measures were the short-term results, complications and functional recovery; moreover, recurrence-free survival (RFS) and overall survival (OS) rates were compared overall and after propensity score matching (PSM) based on age, sex, ASA classification, BMI, carcinoembryonic antigen (CEA) level, use of postoperative chemotherapy, location of tumour, stage and grading, operation time, blood loss and complications. RESULTS: Of 248 transverse resections reviewed, 146 (81 Lap and 65 open) were selected for data analysis. Blood loss, fluid intake and the incidence of wound infection were significantly lower and the hospital stay was significantly shorter in the Lap group (P < 0.001). The operation time and incidence of complications (Clavien-Dindo classification grade 3 or above) did not differ significantly between the two groups. Mean follow-up was of 75.4 months in the Lap group and 78.6 months in the open group. Regression analyses showed that OS was associated with the postoperative carcinoembryonic antigen (CEA) level (hazard ratio 1.18 (95 per cent c.i. 1.10 to 1.27); P < 0.001), BMI (hazard ratio 0.81 (95 per cent c.i. 0.68 to 0.96); P = 0.017), operation time (hazard ratio 0.99 (95 per cent c.i. 0.97 to 1.00; P = 0.010), and postoperative chemotherapy (hazard ratio 0.27 (95 per cent c.i. 0.08 to 0.96); P = 0.042), while RFS was associated with the postoperative CEA level (hazard ratio 1.13 (95 per cent c.i. 1.07 to 1.20); P < 0.001). PSM selected 42 patients for data comparison of long-term results, and showed no significant differences between groups (RFS: P = 0.530; OS: P = 0.561). CONCLUSION: Lap and open resections for transverse colon cancer provided similar outcomes in terms of severe post-operative complication and long-term results.


Assuntos
Colo Transverso , Neoplasias do Colo , Laparoscopia , Colo Transverso/cirurgia , Neoplasias do Colo/cirurgia , Humanos , Pontuação de Propensão , Estudos Retrospectivos
7.
Infect Prev Pract ; 3(3): 100151, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34647007

RESUMO

BACKGROUND: Periodic point prevalence surveys (PPSs) provide a method for assessing changes in healthcare-associated infections (HAIs) and antimicrobial use over time. Following the introduction of an antimicrobial stewardship programme at Nagoya University Hospital (Aichi, Japan) a five-year PPS study was performed to highlight any epidemiological changes. METHODS: One-day PPSs were performed annually in July at Nagoya University Hospital. Data on patient characteristics, medical devices, active HAIs and antimicrobial use were collected using a standard data-collection form. RESULTS: A total of 4339 patients were included. Over the five-year study period the median patient age was 62 years, median duration of hospital admission was nine days, 9% of patients had an HAI and 35.2% received at least one antimicrobial. Overall there were 406 HAIs (95% confidence interval, 369-447) with surgical site infection, pneumonia and febrile neutropenia occurring most frequently. Enterobacterales were the most common pathogens (N = 78, 28.6%) and 32.1% were third-generation cephalosporin-resistant. Meropenem was the most frequently prescribed antimicrobial for HAIs. Surgical antimicrobial prophylaxis changed drastically, with shorter durations and a marked reduction in oral cephalosporin use. However, antimicrobials for medical prophylaxis gradually increased. CONCLUSIONS: This five-year PPS study shows consistent data for patient background, HAIs and causative pathogens and highlights changes in antimicrobial use during the era of the National Action Plan on Antimicrobial Resistance. To describe the epidemiology of Japanese hospitals by PPS, multicentre PPSs including in community hospitals should be performed annually.

8.
J Exp Med ; 173(5): 1083-9, 1991 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-1708808

RESUMO

The complement system augments the humoral immune response to low concentrations of antigen. This effect may be partly mediated by complement receptors on the surface of B lymphocytes that bind immunogenic complexes bearing fragments of C3 and C4. We have shown by immunoprecipitation analysis that the two complement receptors expressed by B lymphocytes, complement receptor 1 (CR1) and CR2, form a detergent-sensitive complex on the surface of tonsillar B lymphocytes and on K562 erythroleukemia cells that were co-transfected with cDNAs encoding CR1 and CR2. The CR1/CR2 complex is distinct from the CR2/CD19 complex and may assist B cell activation by efficiently capturing C3b-containing immunogens and maintaining such immunogens on the B cell after CR1 and factor I-mediated cleavage to iC3b and C3dg. The complement activating immunogen may then trigger signal transduction by the CR1/CR2 complex, the CR2/CD19 complex, or membrane immunoglobulin.


Assuntos
Antígenos de Diferenciação de Linfócitos B/metabolismo , Linfócitos B/metabolismo , Receptores de Complemento/metabolismo , Antígenos CD19 , Antígenos de Diferenciação de Linfócitos B/genética , Antígenos de Diferenciação de Linfócitos B/fisiologia , Linfócitos B/fisiologia , Linfócitos B/ultraestrutura , DNA/genética , Humanos , Leucemia Eritroblástica Aguda/metabolismo , Leucemia Eritroblástica Aguda/patologia , Leucemia Eritroblástica Aguda/fisiopatologia , Tonsila Palatina/citologia , Testes de Precipitina , Receptores de Complemento/genética , Receptores de Complemento/fisiologia , Receptores de Complemento 3b , Receptores de Complemento 3d , Transdução de Sinais/fisiologia , Transfecção/genética
9.
J Exp Med ; 178(4): 1407-17, 1993 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-7690834

RESUMO

The CD21/CD19/TAPA-1 complex of B lymphocytes amplifies signal transduction through membrane immunoglobulin (mIg), recruits phosphatidylinositol 3-kinase (PI3-kinase), and induces homotypic cellular aggregation. The complex is unique among known membrane protein complexes of the immune system because its components represent different protein families, and can be expressed individually. By constructing chimeric molecules replacing the extracellular, transmembrane, and cytoplasmic regions of CD19 and CD21 with those of HLA-A2 and CD4, we have determined that CD19 and TAPA-1 interact through their extracellular domains, CD19 and CD21 through their extracellular and transmembrane domains, and, in a separate complex, CD21 and CD35 through their extracellular domains. A chimeric form of CD19 that does not interact with CD21 or TAPA-1 was expressed in Daudi B lymphoblastoid cells and was shown to replicate two functions of wild-type CD19 contained within the complex: synergistic interaction with mIgM to increase intracellular free calcium and tyrosine phosphorylation and association with the p85 subunit of PI3-kinase after ligation of mIgM. The chimeric CD19 lacked the capacity of the wild-type CD19 to induce homotypic cellular aggregation, a function of the complex that can be ascribed to the TAPA-1 component. The CD21/CD19/TAPA-1 complex brings together independently functioning subunits to enable the B cell to respond to low concentrations of antigen.


Assuntos
Antígenos CD/fisiologia , Antígenos de Diferenciação de Linfócitos B/fisiologia , Antígenos de Diferenciação/fisiologia , Antígenos de Superfície/fisiologia , Linfócitos B/metabolismo , Proteínas de Membrana/fisiologia , Receptores de Complemento 3d/fisiologia , Antígenos CD/química , Antígenos CD19 , Antígenos de Diferenciação de Linfócitos B/química , Sequência de Bases , Linhagem Celular , Dados de Sequência Molecular , Oligodesoxirribonucleotídeos , Receptores de Complemento 3b/fisiologia , Proteínas Recombinantes de Fusão/metabolismo , Transdução de Sinais , Tetraspanina 28 , Células Tumorais Cultivadas
10.
J Exp Med ; 174(6): 1451-60, 1991 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-1836011

RESUMO

CR1/CR2 chimeric receptors in which various short consensus repeats (SCRs) of CR1 were attached to CR2 were transiently expressed on COS cells, and assessed for the binding of polymerized C3b (pC3b) and anti-CR2 by immunofluorescence. Of COS cells expressing chimeras containing SCR 1-4, 1-3, 2-4, 1-2, and 2-3 of the long homologous repeats (LHRs) -B or -C, 96%, 66%, 23%, 0%, and 0%, respectively, bound pC3b. K562 cells were stably transfected with wild-type CR1, deletion mutants of CR1, and the CR1/CR2 chimeras, respectively, and assayed for binding of 125I-pC3b. The dissociation constants (Kd) for pC3b of wild-type CR1 and the LHR-BD and -CD constructs were in the range of 1.0-2.7 nM, and of the CR1/CR2 chimeras containing SCRs 1-4, 1-3, and 2-4 of LHR-B or -C were 1.8-2.4, 6-9, and 22-36 nM, respectively. The factor I-cofactor function of the CR1/CR2 chimeras paralleled the C3b-binding function of the constructs. A CR1/immunoglobulin (Ig) chimeric protein was prepared by fusing SCRs 1-4 of LHR-B to the heavy chains of a murine F(ab')2 anti-nitrophenacetyl (NP) monoclonal antibody. The (CR1)2-F(ab')2 chimera, which retained its specificity for NP, was as effective as soluble, full-length CR1 in binding pC3b, serving as a cofactor for factor I-mediated cleavage of C3b, and inhibiting activation of the alternative pathway, indicating that the bivalent expression of these SCRs reconstitutes the alternative pathway inhibitory function of CR1. The feasibility of creating CR1/Ig chimeras makes possible a new strategy of targeting complement inhibition by the use of Ig fusion partners having particular antigenic specificities.


Assuntos
Complemento C3b/metabolismo , Proteínas Inativadoras do Complemento/farmacologia , Fragmentos Fab das Imunoglobulinas/fisiologia , Receptores de Complemento/metabolismo , Proteínas Recombinantes de Fusão/farmacologia , Animais , Antígenos de Diferenciação de Linfócitos B/metabolismo , Sequência de Bases , Sítios de Ligação , Via Alternativa do Complemento , Humanos , Camundongos , Dados de Sequência Molecular , Receptores de Complemento 3b , Receptores de Complemento 3d , Sequências Repetitivas de Ácido Nucleico
11.
J Exp Med ; 173(1): 55-64, 1991 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-1702139

RESUMO

The complement system augments the humoral immune response, possibly by a mechanism that involves the B lymphocyte membrane receptor, CR2, which binds the C3dg fragment of C3 and triggers several B cell responses in vitro. The present study demonstrates that CR2 associates with a complex of membrane proteins that may mediate signal transduction by ligated CR2. Monoclonal antibodies to CR2 immunoprecipitated from digitonin lysates of Raji B lymphoblastoid cells a membrane complex containing CR2, approximately equimolar amounts of CD19, which is a member of the immunoglobulin superfamily, and three unidentified components: p130, p50, and p20. The complex, which was immunoprecipitated also with anti-CD19, could be dissociated by Nonidet P-40, accounting for its absence in previous studies of CR2. Expression of recombinant CR2 and CD19 in K562 erythroleukemia cells led to formation of a complex that contained not only these two proteins but also p130, p50, and p20, and another component, p14. These unidentified components of the CR2/CD19 complex coimmunoprecipitated with CD19 and not with CR2 from singly transfected cells, indicating primary association with the former. CD19 replicated the capacity of CR2 to interact synergistically with mIgM for increasing free intracellular Ca2+, suggesting that the complex mediates this function of CR2. Therefore, CR2 associates directly with CD19 to become a ligand-binding subunit of a pre-existing signal transduction complex of the B cell that may be representative of a family of membrane protein complexes. This interaction between the complement and immune systems differs from that between immunoglobulin and Clq by involving membrane rather than plasma proteins, and by having complement involved in the afferent phase of the immune response.


Assuntos
Antígenos de Diferenciação de Linfócitos B/fisiologia , Linfócitos B/imunologia , Receptores de Complemento/fisiologia , Antígenos CD/metabolismo , Antígenos CD/fisiologia , Antígenos CD19 , Antígenos de Diferenciação de Linfócitos B/metabolismo , Digitonina , Humanos , Imunoglobulina M/metabolismo , Leucemia Eritroblástica Aguda , Substâncias Macromoleculares , Proteínas de Membrana/metabolismo , Receptores de Complemento/metabolismo , Receptores de Complemento 3d , Transdução de Sinais/imunologia , Transfecção
12.
J Exp Med ; 186(8): 1389-93, 1997 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-9334379

RESUMO

Several members of the chemokine receptor family have been shown to function in association with CD4 to permit human immunodeficiency virus type 1 (HIV-1) entry and infection. The CXC chemokine receptor CXCR4/fusin is a receptor for pre-B cell growth stimulating factor (PBSF)/stromal cell-derived factor 1 (SDF-1) and serves as a coreceptor for the entry of T cell line-tropic HIV-1 strains. Thus, the development of CXCR4 antagonists or agonists may be useful in the treatment of HIV-1 infection. T22 ([Tyr5,12,Lys7]-polyphemusin II) is a synthesized peptide that consists of 18 amino acid residues and an analogue of polyphemusin II isolated from the hemocyte debris of American horseshoe crabs (Limulus polyphemus). T22 was found to specifically inhibit the ability of T cell line-tropic HIV-1 to induce cell fusion and infect the cell lines transfected with CXCR4 and CD4 or peripheral blood mononuclear cells. In addition, T22 inhibited Ca2+ mobilization induced by pre-B cell growth stimulating factor (PBSF)/SDF-1 stimulation through CXCR4. Thus, T22 is a small molecule CXCR4 inhibitor that blocks T cell line-tropic HIV-1 entry into target cells.


Assuntos
Fármacos Anti-HIV/farmacologia , Peptídeos Catiônicos Antimicrobianos , HIV-1/efeitos dos fármacos , Peptídeos/farmacologia , Receptores CXCR4/antagonistas & inibidores , Linfócitos T/virologia , Células 3T3 , Sequência de Aminoácidos , Animais , Glioma , HIV-1/fisiologia , Células HeLa , Humanos , Camundongos , Dados de Sequência Molecular , Osteossarcoma , Linfócitos T/efeitos dos fármacos , Células Tumorais Cultivadas
13.
Heredity (Edinb) ; 104(4): 387-92, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20010960

RESUMO

Differences in mating time between populations can give rise to premating reproductive isolation. Tephritid fruit flies exhibit large variation in mating time among intra- or inter-specific populations. We previously cloned the clock gene period from two strains of melon fly, Bactrocera cucurbitae; in one the individuals mate early during the day, whereas in the other the individuals mate later. These strains were originally established by divergent artificial selection for developmental time, 'short' and 'long', with early and late mating times, respectively. The deduced amino acid sequences of PERIOD proteins for these two strains were reported to be identical. Here we cloned another clock gene cryptochrome (cry) from the two strains, and found two stable amino acid substitutions in the strains. In addition, the allele frequency at the two polymorphic sites of cry gene correlated with the circadian locomotor period (tau) across strains, whereas the expression pattern of cry mRNA in the heads of flies taken from the short strain significantly differed from that from the long strain. These findings suggest that variation in the cry gene is related to differences in the circadian behaviour in the two strains, thus implying that the cry gene may have an important role in reproductive isolation.


Assuntos
Criptocromos/genética , Comportamento Sexual Animal/fisiologia , Maturidade Sexual/genética , Tephritidae/genética , Animais , Sequência de Bases , Proteínas CLOCK/genética , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Especiação Genética , Masculino , Dados de Sequência Molecular , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Homologia de Sequência de Aminoácidos , Maturidade Sexual/fisiologia , Especificidade da Espécie , Tephritidae/crescimento & desenvolvimento , Fatores de Tempo
14.
Eur J Vasc Endovasc Surg ; 39(6): 739-44, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20096610

RESUMO

We report our experience treating four patients with acutely bleeding angiomyolipoma (AML) of sizes between 4 and 12 cm who were managed with endovascular embolisation with a mean follow-up of 10 months. In our case series, we demonstrate that endovascular embolisation in the acute setting for bleeding AMLs is a viable treatment option. AML should be in the differential diagnosis of acutely bleeding renal masses, even when there is no fat assessed by computed tomography (CT) imaging in the renal mass.


Assuntos
Angiomiolipoma/terapia , Cateterismo/métodos , Embolização Terapêutica/métodos , Hemorragia/terapia , Neoplasias Renais/terapia , Doença Aguda , Adulto , Angiografia , Angiomiolipoma/complicações , Angiomiolipoma/diagnóstico , Diagnóstico Diferencial , Feminino , Seguimentos , Hemorragia/diagnóstico , Hemorragia/etiologia , Humanos , Neoplasias Renais/complicações , Neoplasias Renais/diagnóstico , Masculino , Pessoa de Meia-Idade , Nefrectomia , Espaço Retroperitoneal , Tomografia Computadorizada por Raios X
15.
Cell Mol Biol (Noisy-le-grand) ; 56 Suppl: OL1447-52, 2010 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-21215240

RESUMO

Preconditioning of sublethal ischemia implies a cytoprotective mechanism against subsequent ischemia­induced cell death; however, the precise mechanism by which preconditioning protects against ischemic injury is not known. In the present study, we clarified whether pretreatment with a sublethal concentration of H2O2 could counter subsequent H2O2-induced cytotoxicity and also investigated the mechanisms of the cytoprotective effect of a sublethal concentration of H2O2. Using the MTT reduction assay and Calcein-AM staining assay, we showed that pretreatment with H2O2 (10 µM, 24 hr) of COS7 cells partially protected cells against subsequent H2O2 (6 mM, 1 hr) - induced cytotoxicity. The phosphorylation of Akt/PKB, a downstream target of phosphatydylinositol-3 kinase (PI3K), at Ser473 was augmented by H2O2 (10 µM) administration. This augmentation peaked at 10 minutes after H2O2 (10 µM) treatment and fell to the basal level at 24 hr. A blocker of PI3K, LY294002, significantly attenuated H2O2 (10 µM, 24 hr) - induced cytoprotection. In addition, pretreatment with LY294002 reduced H2O2 (10 µM, 10 min)-induced phosphorylation of Akt at Ser473. These findings suggest that a sublethal concentration of H2O2 exerts a cytoprotective effect against subsequent H2O2-induced cell death and that this cytoprotective effect of H2O2 is mediated by activation of the PI3K-Akt signaling pathway.


Assuntos
Peróxido de Hidrogênio/toxicidade , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Animais , Apoptose , Células COS , Chlorocebus aethiops , Cromonas/química , Cromonas/farmacologia , Citoproteção/efeitos dos fármacos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Morfolinas/química , Morfolinas/farmacologia , Fosforilação , Fatores de Tempo
16.
Nature ; 405(6784): 328-30, 2000 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-10830957

RESUMO

Organic solid-state synthesis allows formation of products that are difficult or impossible to produce by conventional methods. This feature, and the high degree of reaction selectivity that can be achieved, is a direct result of the control over the relative orientation of the reactants afforded by the solid state. But as the successful development of 'topochemical reactions' requires the careful design of suitable reactant crystals, the range of both reactions and products amenable to this approach has been limited. However, recent advances in organic crystal engineering, particularly the rational design of complex solid architectures through supramolecular preorganization, have renewed interest in topochemical reactions. Previously, we have orientated muconate monomers--diene moieties with a carboxylate group on each end--using long-chain n-alkylammonium ions, such that the topochemical photopolymerization of the solid-state reactants produces layered crystals of stereoregular and high-molecular-mass polymers. Here we show that these polymer crystals are capable of repeated, reversible intercalation by conversion to the analogous poly(carboxylic acid), followed by transformation into a number of poly(alkylammonium muconate)s upon addition of the appropriate amine. Introduction of functional groups into these crystals may allow the design of organic solids for applications such as molecular recognition, separation and catalysis, thereby extending the range and practical utility of current intercalation compounds.

17.
Proc Biol Sci ; 276(1659): 1037-45, 2009 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-19129104

RESUMO

Using baited camera landers, the first images of living fishes were recorded in the hadal zone (6000-11000 m) in the Pacific Ocean. The widespread abyssal macrourid Coryphaenoides yaquinae was observed at a new depth record of approximately 7000 m in the Japan Trench. Two endemic species of liparid were observed at similar depths: Pseudoliparis amblystomopsis in the Japan Trench and Notoliparis kermadecensis in the Kermadec Trench. From these observations, we have documented swimming and feeding behaviour of these species and derived the first estimates of hadal fish abundance. The liparids intercepted bait within 100-200 min but were observed to preferentially feed on scavenging amphipods. Notoliparis kermadecensis act as top predators in the hadal food web, exhibiting up to nine suction-feeding events per minute. Both species showed distinctive swimming gaits: P. amblystomopsis (mean length 22.5 cm) displayed a mean tail-beat frequency of 0.47 Hz and mean caudal:pectoral frequency ratio of 0.76, whereas N. kermadecensis (mean length 31.5 cm) displayed respective values of 1.04 and 2.08 Hz. Despite living at extreme depths, these endemic liparids exhibit similar activity levels compared with shallow-water liparids.


Assuntos
Ecossistema , Comportamento Alimentar/fisiologia , Peixes/fisiologia , Atividade Motora/fisiologia , Animais , Crustáceos , Oceano Pacífico
18.
Science ; 289(5476): 116-9, 2000 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-10884225

RESUMO

The molecular nature of sweet taste receptors has not been fully explored. Employing a differential screening strategy, we identified a taste receptor gene, Tre1, that controls the taste sensitivity to trehalose in Drosophila melanogaster. The Tre1 gene encodes a novel protein with similarity to G protein-coupled seven-transmembrane receptors. Disruption of the Tre1 gene lowered the taste sensitivity to trehalose, whereas sensitivities to other sugars were unaltered. Overexpression of the Tre1 gene restored the taste sensitivity to trehalose in the Tre1 deletion mutant. The Tre1 gene is expressed in taste sensory cells. These results provide direct evidence that Tre1 encodes a putative taste receptor for trehalose in Drosophila.


Assuntos
Proteínas de Drosophila , Drosophila melanogaster/genética , Genes de Insetos , Receptores de Superfície Celular/genética , Receptores Acoplados a Proteínas G , Paladar , Trealose , Animais , Animais Geneticamente Modificados , Southern Blotting , Clonagem Molecular , DNA Complementar , Drosophila melanogaster/química , Feminino , Hibridização in Situ Fluorescente , Masculino , Dados de Sequência Molecular , Mutação , Estrutura Terciária de Proteína , Receptores de Superfície Celular/química , Receptores de Superfície Celular/metabolismo
19.
Tissue Cell ; 41(1): 75-8, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18656218

RESUMO

Immunohistochemical techniques were employed to examine orexin-like immunoreactivities in the pituitary of the Nile tilapia (Oreochromis niloticus). Rabbit anti-orexin-A serum and mouse anti-orexin-B monoclonal antibodies were used as primary antibodies. Orexin-B immunoreactive cells corresponded to luteinizing hormone (LH)- or thyroid-stimulating hormone (TSH)-containing cells, and all LH- and TSH-containing cells were immunoreactive for orexin-B. However, we found no orexin-A immunoreactive cells in the pituitary. In the Nile tilapia, an orexin-B-like substance may be secreted from LH- or TSH-containing cells and may regulate pituitary function, rather than the orexin-A-like substance in the pituitaries of Japanese seaperch and medaka.


Assuntos
Ciclídeos/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Hormônio Luteinizante/metabolismo , Neuropeptídeos/metabolismo , Hipófise/metabolismo , Tireotropina/metabolismo , Animais , Imunofluorescência , Imuno-Histoquímica , Masculino , Orexinas
20.
Transplant Proc ; 41(3): 816-9, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19376360

RESUMO

We evaluated the effects of a substrate in the biosynthesis of nitric oxide (NO)-l-arginine (LARG)-on hepatic lesions caused by ischemia/reperfusion (I/R) injury in rabbit livers. Rabbits were pretreated with LARG (150 mg/kg IV) or saline solution 0.9% (SS) before the hepatic I/R procedure. The effects of LARG on hepatic injury were evaluated before and after I/R. The warm hepatic I/R procedure produced profound acute liver injury, as indicated by elevated values of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactic dehydrogenase (LDH), as well as a high apoptotic cell count. All changes were attenuated by treatment with LARG before the hepatic I/R procedure. These results suggested that LARG produced protective effects on hepatic I/R lesions. This protective effect of LARG was probably associated with blocking generation of superoxide anions during the hepatic I/R procedure.


Assuntos
Arginina/uso terapêutico , Hepatopatias/prevenção & controle , Traumatismo por Reperfusão/prevenção & controle , Alanina Transaminase/sangue , Alanina Transaminase/efeitos dos fármacos , Animais , Aspartato Aminotransferases/sangue , Aspartato Aminotransferases/efeitos dos fármacos , L-Lactato Desidrogenase/sangue , L-Lactato Desidrogenase/efeitos dos fármacos , Circulação Hepática/efeitos dos fármacos , Masculino , Óxido Nítrico/metabolismo , Coelhos , Traumatismo por Reperfusão/enzimologia , Traumatismo por Reperfusão/patologia , Vasoconstrição/efeitos dos fármacos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA