Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
1.
Gan To Kagaku Ryoho ; 51(7): 775-778, 2024 Jul.
Artigo em Japonês | MEDLINE | ID: mdl-39191699

RESUMO

BACKGROUND: Cancer patients are often complicated by weight loss and malnutrition, thus it is important to provide nutritional therapy in parallel with disease treatment. This study examined the significance of early intervention by NST for cancer patients. METHODS: Seventy-five cancer patients out of 281 patients who underwent NST intervention between July 2021 and June 2022 were included. Intervention outcomes, such as energy and protein sufficiency(=intake/target), and final evaluation by a NST nutritionist at the end of the intervention("improvement"/"unchanged"/"disease progression"/ "death"), were compared between patients who received NST intervention within 7 days from admission(Group A)and after 7 days from admission(Group B). RESULTS: Nutritional sufficiency at the end of NST intervention was higher in Group A for both energy and protein, and the proportion of"improvement"was higher in Group A for the final evaluation by a NST nutritionist. Patients' situation(pre-initial treatment/post-chemotherapy/post-surgery/worsening nutritional status during follow-up)was biased between 2 groups, however Group A showed better results for nutritional sufficiency rate and final evaluation in each subgroup of patients' situation. CONCLUSION: Early intervention may improve the effectiveness of NST for cancer patients. It is important to extract subjects and start NST intervention at early timing.


Assuntos
Neoplasias , Humanos , Neoplasias/terapia , Masculino , Feminino , Idoso , Pessoa de Meia-Idade , Estado Nutricional , Idoso de 80 Anos ou mais , Adulto
2.
PLoS One ; 18(7): e0288051, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37410783

RESUMO

BACKGROUND: Women's childbirth experience of interpersonal care is a significant aspect of quality of care. Due to the lack of a reliable Cambodian version of a measurement tool to assess person-centered maternity care, the present study aimed to adapt the "Person-Centered Maternity Care (PCMC) scale" to the Cambodian context and further determine its psychometric properties. METHODS: The PCMC scale was translated into Khmer using the team translation approach. The Khmer version of PCMC (Kh-PCMC) scale was pretested among 20 Cambodian postpartum women using cognitive interviewing. Subsequently, the Kh-PCMC scale was administered in a survey with 300 Cambodian postpartum women at two governmental health facilities. According to the COnsensus-based Standards for the Selection of health status Measurement Instruments (COSMIN) standard, we performed psychometric analysis, including content validity, construct validity, criterion validity, cross-cultural validity, and internal consistency. RESULTS: The preliminary processes of Kh-PCMC scale development including cognitive interviewing and expert review ensured appropriate levels of content validity and acceptable levels of cross-cultural validity of the Kh-PCMC scale with four-point frequency responses. The Scale-level Content Validity Index, Average (S-CVI/Avg) of 30-item Kh-PCMC scale was 0.96. Twenty items, however, performed optimally in the psychometric analysis from the data in Cambodia. The 20-item Kh-PCMC scale produced Cronbach's alpha of 0.86 for the full scale and 0.76-0.91 for the subscales, indicating adequately high internal consistency. Hypothesis testing found positive correlations between the 20-item Kh-PCMC scale and reference measures, which implies acceptable criterion validity. CONCLUSIONS: The present study produced the Kh-PCMC scale that enables women's childbirth experiences to be quantitatively measured. The Kh-PCMC scale can identify intrapartum needs from women's perspectives for quality improvement in Cambodia. However, dynamic changes in and diverse differences of cultural context over time across provinces in Cambodia require the Kh-PCMC scale to be regularly reexamined and, when needed, to be further adjusted.


Assuntos
Serviços de Saúde Materna , Humanos , Gravidez , Feminino , Camboja , Reprodutibilidade dos Testes , Parto , Inquéritos e Questionários , Psicometria , Instalações de Saúde
3.
PLoS One ; 18(1): e0265784, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36595538

RESUMO

BACKGROUND: In Cambodia, the importance of valuing women's childbirth experiences in improving quality of care has been understudied. This is largely because of absence of reliable Khmer tools for measuring women's intrapartum care experiences. Generally, cross-cultural development of those tools often involves translation from a source language into a target language. Yet, few earlier studies considered Cambodian cultural context. Thus, we developed the Cambodian version of the Person-Centered Maternity Care (PCMC) scale, by culturally adapting its original to Cambodian context for ensuring cultural equivalence and content validity. METHODS: Three rounds of cognitive interviewing with 20 early postpartum women were conducted at two governmental health facilities in Cambodia. Cognitive interviewing was composed of structured questionnaire pretesting and qualitative probing. The issues identified in the process of transcribing and translating audio-recorded cognitive interviews were iteratively discussed among study team members, and further analyzed. RESULTS: A total of 14 issues related to cultural adaptations were identified in the 31 translated questions for the Cambodian version of the PCMC scale. Our study identified three key findings: (i) discrepancies between the WHO recommendations on intrapartum care and Cambodian field realities; (ii) discrepancies in recognition on PCMC between national experts and local women; and (iii) challenges in correctly collecting and interpreting less-educated women's views on intrapartum care. CONCLUSION: Not only women's verbal data but also their non-verbal data and cultural contexts should be comprehensively counted, when reflecting Cambodian women's intrapartum practice realities in the translated version. This is the first study that attempted to develop the tool for measuring Cambodian women's experiences during childbirth, by addressing cross-cultural issues.


Assuntos
Serviços de Saúde Materna , Humanos , Feminino , Gravidez , Camboja , Período Pós-Parto , Parto , Instalações de Saúde
4.
Somatosens Mot Res ; 36(4): 298-301, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31722637

RESUMO

Purpose: Given that walking speed declines with ageing and decreasing walking speed restricts activities of daily living (ADL), it is important for the old to maintain walking speed in order to prevent affecting ADL. Although skin cold stimulation (SCS) facilitates instantaneous muscle activity, which occurs during walking, the effects of SCS on muscle activity during walking remain unclear. Thus, the present study aimed to investigate the effect of SCS during walking in older adults.Methods: Seventeen community-dwelling healthy older adults (73 ± 6 years old) participated in this study. Walking speed at a comfortable pace and the electromyographic (EMG) activity of the vastus lateralis (VL) and biceps femoris (BF) were measured. SCS, which maintains the skin temperature at 25 °C, was applied to the front of the thigh during the procedures. Walking speed, root mean square EMG (rmsEMG) and mean power frequency (MPF) were compared under SCS and control conditions.Results: SCS significantly increased the walking speed (p < 0.01) and the rmsEMG of the vastus lateralis (p = 0.032). No change in the rmsEMG of the BF was observed, and SCS had no effect on MPF of both the VL and BF. Furthermore, a significant relationship was observed between these changes (r = 0.619, p = 0.042).Conclusion: SCS increased the EMG activity of the VL while increasing walking speed. Our results suggest that SCS is an effective strategy that can be included in daily life in order to improve walking ability of older adults.


Assuntos
Envelhecimento/fisiologia , Músculo Quadríceps/fisiologia , Temperatura Cutânea/fisiologia , Velocidade de Caminhada/fisiologia , Atividades Cotidianas , Idoso , Idoso de 80 Anos ou mais , Temperatura Baixa , Eletromiografia , Feminino , Humanos , Masculino , Estimulação Física
5.
J Occup Health ; 58(1): 47-55, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26498978

RESUMO

OBJECTIVES: We studied the physical and mental conditions of 8 healthy young female ambulance paramedics working 24-hour shifts during their menstrual cycle, including assessment of cardiac autonomic nervous system activity by heart rate variability power spectral analysis. METHODS: The autonomic activity during the awake period of on- and off-duty days in the follicular, late luteal, and menstruation phases was measured. Questionnaires regarding fatigue and menstrual distress were administered and correlated with the autonomic profile. RESULTS: While degrees of fatigue significantly increased after work, the changes in autonomic activity during the awake period on on-duty days were not significantly different from those on off-duty days (LF/HF, p=0.123; HF/(HF+LF), p=0.153). As for the sleeping period, there were no significant differences. Although the Menstrual Distress Questionnaire (MDQ) revealed the presence of mild menstrual discomfort in the late luteal and menstruation phases, no significant difference was observed in the autonomic profile of the three menstrual cycle phases. No significant correlation was observed between the degree of menstrual distress and autonomic profile, though there was a significant correlation in the late luteal phase between degree of menstrual distress and fatigue after work (p<0.01). CONCLUSION: These results showed that, while subjects experienced menstrual discomfort and fatigue after work, their autonomic profile did not alter in the menstrual cycle. It is suggested that healthy young female ambulance paramedics may tolerate 24-hour shifts, though attention should be paid to subjective menstrual symptoms and fatigue.


Assuntos
Pessoal Técnico de Saúde/psicologia , Sistema Nervoso Autônomo/fisiopatologia , Ritmo Circadiano/fisiologia , Tolerância ao Trabalho Programado/fisiologia , Adulto , Ambulâncias , Fadiga/fisiopatologia , Fadiga/psicologia , Feminino , Voluntários Saudáveis , Frequência Cardíaca/fisiologia , Humanos , Japão , Ciclo Menstrual , Doenças Profissionais/fisiopatologia , Doenças Profissionais/psicologia , Estresse Psicológico/fisiopatologia , Estresse Psicológico/psicologia , Tolerância ao Trabalho Programado/psicologia , Adulto Jovem
6.
Res Vet Sci ; 92(2): 327-32, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21477828

RESUMO

The infection of the feline T-lymphocyte cell line FeT-J with the feline immunodeficiency virus (FIV) Petaluma strain led to the establishment of nonvirus-producing cells. One clone (C15) obtained by limiting dilution was found to express FIV in response to chemical inducers of retroviruses. The chemical treatment of C15 cells led to not only FIV protein synthesis but also an augmentation of viral production. Examination of the C15 cell derivatives obtained by recloning revealed that 10-40% of treated cells constitutively expressed FIV antigens, whereas 100% with expressed FIV antigen in response to the inducer. Chemical induction resulted in more than a 100-fold increase in infectious viral production. The results suggest that a majority of FeT-J cells that are infected with FIV exist in a non-productive state. Establishing a cell line that can be non-productively infected by FIV may help determine the mechanisms of FIV latency.


Assuntos
Síndrome de Imunodeficiência Adquirida Felina/virologia , Vírus da Imunodeficiência Felina/fisiologia , Linfócitos T/virologia , Ativação Viral/fisiologia , Animais , Gatos , Linhagem Celular , Citometria de Fluxo , Imunofluorescência , Linfócitos T/citologia , Latência Viral/fisiologia
7.
Mol Cell Biochem ; 363(1-2): 357-66, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22193458

RESUMO

Migraine is a multifactorial disease with various factors, such as genetic polymorphisms and personality traits, but the contribution of those factors is not clear. To clarify the pathogenesis of migraine, the contributions of genetic polymorphisms and personality traits were simultaneously investigated using multivariate analysis. Ninety-one migraine patients and 119 non-headache healthy volunteers were enrolled. The 12 gene polymorphisms analysis and NEO-FFI personality test were performed. At first, the univariate analysis was performed to extract the contributing factors to pathogenesis of migraine. We then extracted the factors that independently contributed to the pathogenesis of migraine using multivariate stepwise logistic regression analysis. Using the multivariate analysis, three gene polymorphisms including monoamine oxidase A (MAOA) T941G, methylenetetrahydrofolate reductase (MTHFR) C677T, and tumor necrosis factor beta (TNF-ß) G252Α, and the neuroticism and conscientiousness scores in NEO-FFI were selected as significant factors that independently contributed to the pathogenesis of migraine. Their odds ratios were 1.099 (per point of neuroticism score), 1.080 (per point of conscientiousness score), 2.272 (T and T/T or T/G vs G and G/G genotype of MAOA), 1.939 (C/T or T/T vs C/C genotype of MTHFR), and 2.748 (G/A or A/A vs G/G genotype of TNF-ß), respectively. We suggested that multiple factors, such as gene polymorphisms and personality traits, contribute to the pathogenesis of migraine. The contribution of polymorphisms, such as MAOA T941G, MTHFR C677T, and TNF-ß G252A, were more important than personality traits in the pathogenesis of migraine, a multifactorial disorder.


Assuntos
Linfotoxina-alfa/genética , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Transtornos de Enxaqueca/genética , Transtornos de Enxaqueca/psicologia , Monoaminoxidase/genética , Personalidade , Polimorfismo Genético , Adulto , Estudos de Casos e Controles , Distribuição de Qui-Quadrado , Feminino , Frequência do Gene , Predisposição Genética para Doença , Humanos , Japão , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Transtornos de Enxaqueca/enzimologia , Transtornos de Enxaqueca/imunologia , Análise Multivariada , Razão de Chances , Testes de Personalidade , Medição de Risco , Fatores de Risco , Inquéritos e Questionários
8.
Arch Biochem Biophys ; 506(1): 83-91, 2011 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-21081108

RESUMO

Sphingolipids act as signaling mediators that regulate a diverse range of cellular events. Although numerous sphingolipid functions have been studied, little is known about the effect of sphingolipids on monocyte differentiation into macrophages. Here, we report that two lysosphingolipids, sphingosylphosphorylcholine (SPC) and lysosulfatide (LSF), inversely affect macrophagic differentiation of monocytic cell lines, U937 and THP-1. Molecular analyses revealed that SPC enhances, whereas LSF suppresses, phorbol ester-induced classical (M1-polarized) differentiation to macrophages. The expression of CD11b, a macrophage marker, was induced in accordance with the activation status of the Raf/MEK/ERK signaling pathway in which SPC and LSF had opposite effects. Pharmacological inhibition of this pathway aborted the differentiation, indicating that this signaling pathway is required. Consistently, SPC promoted, while LSF inhibited, monocyte adhesion to fibronectin, through the phosphatidylinositol-3-kinase (PI3K)/Akt signaling pathway. The effects of SPC on Raf/MEK/ERK and PI3K/Akt signaling were dependent on G(i/o), whereas the SPC-induced calcium influx was dependent on G(q). Thus SPC utilizes G-protein coupled receptor. In contrast, the effects of LSF were independent of G(i/o) and G(q). These results suggest that SPC enhances, whereas LSF suppresses, monocyte differentiation into macrophages through regulating the Raf/MEK/ERK and PI3K/Akt signaling pathways via distinct mechanisms.


Assuntos
Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Monócitos/citologia , Monócitos/efeitos dos fármacos , Fosforilcolina/análogos & derivados , Psicosina/análogos & derivados , Esfingosina/análogos & derivados , Sequência de Bases , Cálcio/metabolismo , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/genética , Diferenciação Celular/fisiologia , Linhagem Celular , Primers do DNA/genética , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/metabolismo , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/metabolismo , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Macrófagos/metabolismo , Monócitos/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilcolina/metabolismo , Fosforilcolina/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Psicosina/metabolismo , Psicosina/farmacologia , Receptores de Lisoesfingolipídeo/metabolismo , Transdução de Sinais/efeitos dos fármacos , Esfingosina/metabolismo , Esfingosina/farmacologia , Acetato de Tetradecanoilforbol/farmacologia , Células U937 , Quinases raf/metabolismo
9.
Biol Pharm Bull ; 33(10): 1751-3, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20930387

RESUMO

We investigated the possible association of serotonin (5-HT) 2A receptor gene A-1438G polymorphism in Japanese patients with migraine. Genotyping of 5-HT(2A) A-1438G polymorphism was performed by polymerase chain reaction-restriction fragment length polymorphism in patients with migraine (male 17 : 3 with aura and 14 without aura, female 65 : 17 with aura and 48 without aura) and controls (male 31, female 84). The distribution of 5-HT(2A) A-1438G genotype frequency between migraine patients and controls did not differ. These results suggest that the A-1438G polymorphism of the 5-HT(2A) receptor gene is not a direct risk factor for migraine; however, the incidence of the A/A genotype between migraine with aura (MA) and without aura (MO) was significantly different. The 5-HT(2A) A-1438G polymorphism may be involved in determining the subtypes of migraine in Japanese.


Assuntos
Transtornos de Enxaqueca/genética , Enxaqueca com Aura/genética , Polimorfismo de Nucleotídeo Único , Receptor 5-HT2A de Serotonina/genética , Adulto , Feminino , Predisposição Genética para Doença , Humanos , Japão , Masculino , Pessoa de Meia-Idade
10.
Bioorg Med Chem ; 18(11): 3720-5, 2010 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-20409718

RESUMO

Siglec-2 is a mammalian sialic acid binding protein expressed on B-cell surfaces and is involved in the modulation of B-cell mediated immune response. We synthesized a unique starfish ganglioside, AG2 pentasaccharide Galfbeta(1-3)Galpalpha(1-4)Neu5Acalpha(2-3)Galpbeta(1-4)Glcp, and found that the synthetic pentasaccharide binds to human Siglec-2 by performing (1)H NMR experiments. Saturation transfer difference NMR experiments indicated that the C7-C9 side-chain and the acetamide moiety of the central sialic acid residue were located in the binding face of human Siglec-2. We determined the binding epitope of AG2 pentasaccharide to human Siglec-2, as the Galpalpha(1-4)Neu5Acalpha(2-3)Galp unit.


Assuntos
Espectroscopia de Ressonância Magnética/métodos , Oligossacarídeos/química , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/química , Sítios de Ligação , Epitopos , Gangliosídeos/química , Humanos , Ligação Proteica , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/imunologia , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/metabolismo
11.
J Feline Med Surg ; 12(4): 269-77, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19896878

RESUMO

The infection of feline thymic lymphoma 3201 cells with a cell culture-adapted Petaluma strain of feline immunodeficiency virus (FIV) led to the establishment of survivor cells designated as 3201-S after a productive infection associated with extensive cell killing. 3201-S cells were free of FIV DNA, and were found to express CXCR4, a coreceptor for infection but not CD134, a primary receptor. When 3201-S cells were reinfected with FIV, viral DNA was transiently detectable for 5 days postinfection, indicating that 3201-S cells cannot support the FIV replicative cycle. Furthermore, comparative studies found that in contrast to SDF-1alpha-responsive 3201 cells, 3201-S cells did not show a flux of Ca(2+) in response to SDF-1alpha, implying that CXCR4 is not functionally active on 3201-S cells. These results suggest that 3201 cells can be heterogeneous in the phenotype of the CXCR4 expressed, and this heterogeneity may account for the differences in susceptibility to FIV. Determining the mechanism(s) within 3201-S cells that restrict FIV could result in therapeutic strategies against FIV infection.


Assuntos
Quimiocinas CXC/metabolismo , DNA Viral/metabolismo , Vírus da Imunodeficiência Felina/metabolismo , Linfócitos/virologia , Receptores CXCR4/metabolismo , Animais , Cálcio/metabolismo , Gatos , Linhagem Celular Transformada , Quimiocina CXCL12 , Genes env , Vírus da Imunodeficiência Felina/genética , Vírus da Imunodeficiência Felina/imunologia , Receptores CXCR4/fisiologia , Regulação para Cima
12.
J Vet Med Sci ; 71(12): 1623-8, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20046030

RESUMO

The concentrations of branched-chain amino acids (BCAA; valine, leucine, isoleucine) were determined in plasma of 7 healthy thoroughbred mares and their foals from birth (0 week) to 24 weeks of age, using automated high-performance liquid chromatography. In foals, the concentrations of plasma valine were significantly high (p<0.05) at 16, 20 and 24 weeks. The concentrations of plasma leucine were significantly high (p<0.05) at 1 and 3 weeks. The concentrations of plasma isoleucine were significantly high (p<0.05) from 1 to 24 weeks. In mares, the concentrations of plasma valine were significantly high (p<0.05) at 16 and 24 weeks. The concentrations of plasma leucine and isoleucine were significantly high (p<0.05) at 16 weeks. It was clear that the concentrations of plasma BCAA in foals and mares were at different levels at various times after birth. Since mares and foals were kept in health during this study, we could get the base data of the concentrations of BCAA in plasma of healthy foals and mares from birth to 24 weeks.


Assuntos
Envelhecimento , Aminoácidos de Cadeia Ramificada/sangue , Cavalos/sangue , Animais , Animais Recém-Nascidos , Feminino , Cavalos/crescimento & desenvolvimento
13.
FEBS Lett ; 582(10): 1444-50, 2008 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-18381075

RESUMO

To understand physiological roles of tissue mast cells, we established a culture system where bone marrow-derived immature mast cells differentiate into the connective tissue-type mast cell (CTMC)-like cells through modifying the previous co-culture system with Swiss 3T3 fibroblasts. Our system was found to reproducibly mimic the differentiation of CTMCs on the basis of several criteria, such as granule maturation and sensitivity to cationic secretagogues. The gene expression profile obtained by the microarray analyses was found to reflect many aspects of the differentiation. Our system is thus helpful to gain deeper insights into terminal differentiation of CTMCs.


Assuntos
Diferenciação Celular , Mastócitos/citologia , Mastócitos/fisiologia , Modelos Biológicos , Animais , Células da Medula Óssea/citologia , Técnicas de Cultura de Células , Diferenciação Celular/genética , Células Cultivadas , Feminino , Perfilação da Expressão Gênica , Histamina/análise , Mastócitos/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Análise de Sequência com Séries de Oligonucleotídeos , Peptídeo Hidrolases/metabolismo , Peritônio/citologia , Células Swiss 3T3
15.
PLoS One ; 2(11): e1232, 2007 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-18043739

RESUMO

BACKGROUND: Glycan biosynthesis occurs though a multi-step process that requires a variety of enzymes ranging from glycosyltransferases to those involved in cytosolic sugar metabolism. In many cases, glycan biosynthesis follows a glycan-specific, linear pathway. As glycosyltransferases are generally regulated at the level of transcription, assessing the overall transcriptional profile for glycan biosynthesis genes seems warranted. However, a systematic approach for assessing the correlation between glycan expression and glycan-related gene expression has not been reported previously. METHODOLOGY: To facilitate genetic analysis of glycan biosynthesis, we sought to correlate the expression of genes involved in cell-surface glycan formation with the expression of the glycans, as detected by glycan-recognizing probes. We performed cross-sample comparisons of gene expression profiles using a newly developed, glycan-focused cDNA microarray. Cell-surface glycan expression profiles were obtained using flow cytometry of cells stained with plant lectins. Pearson's correlation coefficients were calculated for these profiles and were used to identify enzyme genes correlated with glycan biosynthesis. CONCLUSIONS: This method, designated correlation index-based responsible-enzyme gene screening (CIRES), successfully identified genes already known to be involved in the biosynthesis of certain glycans. Our evaluation of CIRES indicates that it is useful for identifying genes involved in the biosynthesis of glycan chains that can be probed with lectins using flow cytometry.


Assuntos
Testes Genéticos/métodos , Glicosiltransferases/genética , Análise de Sequência com Séries de Oligonucleotídeos , Polissacarídeos/biossíntese , DNA Complementar/genética , Citometria de Fluxo , Perfilação da Expressão Gênica , Glicosiltransferases/metabolismo
16.
Mol Cell Biol ; 27(8): 3008-22, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17296732

RESUMO

Sialic acid (Sia) is a family of acidic nine-carbon sugars that occupies the nonreducing terminus of glycan chains. Diversity of Sia is achieved by variation in the linkage to the underlying sugar and modification of the Sia molecule. Here we identified Sia-dependent epitope specificity for GL7, a rat monoclonal antibody, to probe germinal centers upon T cell-dependent immunity. GL7 recognizes sialylated glycan(s), the alpha2,6-linked N-acetylneuraminic acid (Neu5Ac) on a lactosamine glycan chain(s), in both Sia modification- and Sia linkage-dependent manners. In mouse germinal center B cells, the expression of the GL7 epitope was upregulated due to the in situ repression of CMP-Neu5Ac hydroxylase (Cmah), the enzyme responsible for Sia modification of Neu5Ac to Neu5Gc. Such Cmah repression caused activation-dependent dynamic reduction of CD22 ligand expression without losing alpha2,6-linked sialylation in germinal centers. The in vivo function of Cmah was analyzed using gene-disrupted mice. Phenotypic analyses showed that Neu5Gc glycan functions as a negative regulator for B-cell activation in assays of T-cell-independent immunization response and splenic B-cell proliferation. Thus, Neu5Gc is required for optimal negative regulation, and the reaction is specifically suppressed in activated B cells, i.e., germinal center B cells.


Assuntos
Anticorpos Monoclonais/imunologia , Linfócitos B/imunologia , Centro Germinativo/imunologia , Ativação Linfocitária/imunologia , Ácido N-Acetilneuramínico/metabolismo , Ácidos Neuramínicos/metabolismo , Animais , Linfócitos B/citologia , Células CHO , Proliferação de Células , Cricetinae , Cricetulus , Epitopos/imunologia , Marcação de Genes , Humanos , Lectinas/metabolismo , Ligantes , Camundongos , Oxigenases de Função Mista/deficiência , Oxigenases de Função Mista/genética , Fosfotirosina/metabolismo , Polissacarídeos/metabolismo , Ratos , Receptores de Antígenos de Linfócitos B/metabolismo , Lectinas Semelhantes a Imunoglobulina de Ligação ao Ácido Siálico , Sialiltransferases/metabolismo , Baço/imunologia , beta-D-Galactosídeo alfa 2-6-Sialiltransferase
17.
Clin Endocrinol (Oxf) ; 62(4): 458-65, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15807877

RESUMO

OBJECTIVE: Persistent hyperinsulinaemic hypoglycaemia of infancy (PHHI) is a disorder of glucose metabolism that is characterized by dysregulated secretion of insulin from pancreatic beta-cells. This disease has been reported to be associated with mutations of the sulfonylurea receptor SUR1 (ABCC8) or the inward-rectifying potassium channel Kir6.2 (KCNJ11), which are two subunits of the pancreatic beta-cell ATP-sensitive potassium channel. PATIENTS AND METHODS: In 14 Japanese PHHI patients, all exons of SUR1 and Kir6.2 genes were analysed by polymerase chain reaction (PCR) and direct sequencing. Four patients responded to diazoxide, and nine patients underwent a subtotal pancreatectomy. Histologically, seven patients were diagnosed to have a focal form and two a diffuse form of the disease. RESULTS: We found nine novel mutations in the SUR1 gene and two in the Kir6.2 gene. In the SUR1 gene mutations, three were nonsense mutations (Y512X, Y1354X and G1469X), one was a one-base deletion in exon 7, and two were missense mutations in the nucleotide-binding domain 2 (K1385Q, R1487K). The other three mutations occurred in introns 14, 29 and 36, which might cause aberrant splicing of RNA. Two siblings in one family were heterozygotes for a missense mutation, K1385Q, which was maternally inherited. In Kir6.2 gene screening, one patient was found to be a compound heterozygote of a missense mutation (R34H) and a one-base deletion (C344fs/ter). CONCLUSION: The novel mutations reported here could be pathological candidates for PHHI in Japan. They also reveal that SUR1 and Kir6.2 mutations in the Japanese population exhibit heterogeneity and that they occurred at a frequency similar to other genetic populations.


Assuntos
Hiperinsulinismo Congênito/genética , Ilhotas Pancreáticas/enzimologia , Mutação , Canais de Potássio/genética , Transportadores de Cassetes de Ligação de ATP/genética , Trifosfato de Adenosina/metabolismo , Povo Asiático , Membrana Celular/metabolismo , Hiperinsulinismo Congênito/metabolismo , Marcadores Genéticos , Genótipo , Heterozigoto , Humanos , Recém-Nascido , Japão , Mutação de Sentido Incorreto , Linhagem , Mutação Puntual , Polimorfismo Conformacional de Fita Simples , Canais de Potássio Corretores do Fluxo de Internalização/genética , Receptores de Droga/genética , Receptores de Sulfonilureias
18.
Nagoya J Med Sci ; 67(3-4): 101-8, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17375476

RESUMO

Malignant transformation of cells is frequently associated with an augmented production of hyaluronan and the subsequent formation of a hyaluronan-matrix. In v-Src-transformed cells, hyaluronan directly activate cell motility in a tumor-specific manner. Despite its importance, the mechanism by which v-Src activates hyaluronan production remains unclear. Here we report that multiple signaling pathways are required for the augmented production of hyaluronan. Either the expression of a dominant negative Ras or the treatment of cells with manumycin A, a Ras farnesyltransferase inhibitor, was able to suppress hyaluronan production. In contrast, expression of MEK1EE, a constitutive form of MEK1, activated both hyaluronan synthase expression and hyaluronan production. AG-490, a Jak-2 inhibitor, or LY294002, a PI3K inhibitor, similarly suppressed the augmented production of hyarulonan. Taken together, our results suggest the involvement of multiple signaling pathways, including Ras-dependent and independent ones, in augmented hyaluronan production by v-Src.


Assuntos
Ácido Hialurônico/biossíntese , Proteína Oncogênica pp60(v-src)/genética , Transdução de Sinais/fisiologia , Animais , Linhagem Celular , Cromonas/farmacologia , Dimetil Sulfóxido/farmacologia , Inibidores Enzimáticos/farmacologia , Flavonoides/farmacologia , Expressão Gênica/efeitos dos fármacos , Glucuronosiltransferase/genética , Glucuronosiltransferase/metabolismo , Hialuronan Sintases , Immunoblotting , Isoenzimas/genética , Isoenzimas/metabolismo , Janus Quinase 2/antagonistas & inibidores , Janus Quinase 2/genética , Janus Quinase 2/metabolismo , MAP Quinase Quinase 1/antagonistas & inibidores , MAP Quinase Quinase 1/genética , MAP Quinase Quinase 1/metabolismo , Morfolinas/farmacologia , Mutação , Proteína Oncogênica pp60(v-src)/metabolismo , Polienos/farmacologia , Alcamidas Poli-Insaturadas/farmacologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais/efeitos dos fármacos , Fatores de Tempo , Tirfostinas/farmacologia
19.
Endocr J ; 50(1): 9-20, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12733705

RESUMO

To elucidate its effect on proinsulin processing, we introduced the expression of a Pittsburgh type-mutant, alpha1-protease inhibitor M/R (alpha1-PIM/R) and its chimera protein with growth hormone (GH) (GHalpha1-PIM/R) into MIN6 cells. In metabolic labeling and chasing experiments with [3H]-Leu and [35S]-Met, proinsulin appeared in the medium during stimulatory secretion only from MIN6 clones expressing GHalpha1-PIM/R and, surprisingly, alpha1-PIM/R, but not from the clones of either the control or alpha1-PI. The major part of alpha1-PIM/R was secreted through the constitutive pathway and about 10% of total secreted alpha1-PIM/R in the chase periods entered the regulated pathway. On the other hand, GHalpha1-PIM/R was mainly transported to the secretory granules and about 80% of the total secreted GHalpha1-PIM/R in the chase periods was secreted during stimulatory secretion. In the first 3 h chase periods without stimulation, only alpha1-PIM/R and no GHalpha1-PIM/R appeared in the medium, thus suggesting that alpha1-PIM/R might be transported through a constitutive-like pathway for those periods. The alpha1-PI, which had no inhibitory effect on proinsulin processing, showed similar secretion pathways to those of alpha1-PIM/R. This implies that some part of alpha1-PIM/R and alpha1-PI entered the regulated pathway, not due to any specific interaction between the processing endoproteases and serine protease inhibitors, but due to some type of passive transport in a nonselective manner. The inhibitory effect of alpha1-PIM/R in the regulated secretory pathway was slightly but clearly evident when it was expressed in MIN6 beta-cells.


Assuntos
Ilhotas Pancreáticas/metabolismo , Ilhotas Pancreáticas/fisiologia , alfa 1-Antitripsina/genética , Animais , Northern Blotting , Linhagem Celular Tumoral , Furina/genética , Hormônio do Crescimento/genética , Imuno-Histoquímica , Insulinoma , Ilhotas Pancreáticas/citologia , Camundongos , Camundongos Transgênicos , Mutação , Proinsulina/metabolismo , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Vesículas Secretórias/metabolismo , alfa 1-Antitripsina/metabolismo
20.
Biochemistry ; 42(14): 4300-9, 2003 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-12680784

RESUMO

Although the induction of glutathione S-transferase (GST) activity by tert-butylhydroquinone (tBHQ) has been well-documented in several cell culture systems and rodent experiments, the exact mechanism responsible for its inducibility is still not thoroughly understood. To more precisely define the molecular mechanism of GST induction by tBHQ, we examined the one-electron oxidation and glutathione (GSH) reaction potentials of tBHQ as compared to its analogue, 2,5-di-tert-butylhydroquinone (DtBHQ). tBHQ and DtBHQ showed similar one-electron oxidation potentials, including free radical quenching (antioxidant), oxidative conversion of both compounds to a benzoquinone form, and Cu(2+)-dependent superoxide generation. On the other hand, the reduced GSH level was observed by the addition of tBHQ, but not DtBHQ, suggesting that tBHQ acts as an electrophile while DtBHQ does not. The data were consistent with the observation that tBHQ more potently induced the GSTP1 gene expression in RL34 cells than DtBHQ did. Moreover, we indeed detected the GSH-tBHQ conjugates in the cells exposed to tBHQ using an electrochemical detector-high-performance liquid chromatography technique. Thus, we conclude that an electrophilic quinone oxidation product that reacts with intracellular nucleophiles including protein thiol or GSH plays a major role in the GSTP1 gene expression.


Assuntos
Glutationa Transferase/biossíntese , Hidroquinonas/farmacologia , Linhagem Celular , Indução Enzimática , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Glutationa Transferase/genética , Glutationa Transferase/metabolismo , Oxirredução
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA