Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 62
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Crit Rev Food Sci Nutr ; : 1-19, 2022 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-36377721

RESUMO

As a nutrient rich emulsion extracted from plant materials, plant-based milk (PBM) has been the latest trend and hot topic in the food industry due to the growing awareness of consumers toward plant-based products in managing the environmental (carbon footprint and land utility), ethical (animal well-fare) and societal (health-conscious) issues. There have been extensive studies and reviews done to discuss the distinct perspective of PBM including its production, health effects and market acceptance. However, not much has been emphasized on the valuable antioxidants present in PBM which is one of the attributes making them stand apart from dairy milk. The amounts of antioxidants in PBM are important. They offered tremendous health benefits in maintaining optimum health and reducing the risk of various health disorders. Therefore, enhancing the extraction of antioxidants and preserving their activity during production and storage is important. However, there is a lack of a comprehensive review of how these antioxidants changes in response to different processing steps involved in PBM production. Presumably, antioxidants in PBM could be potentially lost due to thermal degradation, oxidation or leaching into processing water. Hence, this paper aims to fill the gaps by addressing an extensive review of how different production steps (germination, roasting, soaking, blanching, grinding and filtration, and microbial inactivation) affect the antioxidant content in PBM. In addition, the effect of different microbial inactivation treatments (thermal or non-thermal processing) on the alteration of antioxidant in PBM was also highlighted. This paper can provide useful insight for the industry that aims in selecting suitable processing steps to produce PBM products that carry with them a health declaration.

2.
J Cell Biol ; 110(3): 617-24, 1990 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-2307701

RESUMO

Immunologically cross-reactive isoforms of the cytoskeletal element protein 4.1 have been identified in many tissues in which they exhibit heterogeneity of molecular weight, abundance, and intracellular localization. To examine the basis for isoform production in erythroid and nonerythroid tissues, we have compared the structure and expression of cDNAs isolated from human erythroid and nonerythroid sources. We have encountered cDNAs representing many distinct mRNA sequences. These exhibit complete nucleotide sequence homology along most of their lengths. Differences were confined to five sequence blocks designated Motifs I-V, which were present or absent in each mRNA moiety. Motif I was expressed only in erythroid cells; it encodes 21 amino acids in a well-characterized spectrin/actin binding domain. Motif II, located near the COOH terminus of the 80-kD "erythroid" protein 4.1 molecule is present in the vast majority of transcripts from both erythroid and nonerythroid cells. Motifs IV and V alter the 5' untranslated region: simultaneous insertion of Motif IV and deletion of Motif V in the untranslated region inserts a new initiator methionine and establishes a contiguous open reading frame encoding a novel 135-kD protein 4.1 molecule. By immunochemical analysis we have identified the longer isoform in cells. Our results are most consistent with tissue-specific alternative mRNA splicing of transcripts of the protein 4.1 gene to yield numerous isoforms. These isoforms exhibit tissue specificity and alter strategic portions of the molecule. Moreover, we describe a novel high molecular weight form of protein 4.1 that arises by splicing events which allow translation at an upstream site.


Assuntos
Proteínas do Citoesqueleto , Genes , Proteínas de Membrana/genética , Neuropeptídeos , RNA Mensageiro/genética , Sequência de Aminoácidos , Sequência de Bases , Linhagem Celular , DNA de Neoplasias/genética , Membrana Eritrocítica/metabolismo , Biblioteca Gênica , Humanos , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Sondas de Oligonucleotídeos , Especificidade de Órgãos , Peptídeos/síntese química , Biossíntese de Proteínas , Mapeamento por Restrição
3.
Lett Appl Microbiol ; 48(5): 560-5, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19291216

RESUMO

AIMS: To compare bacterial populations and antimicrobial resistance patterns between clinical and sewage isolates from a regional hospital in northern Taiwan. The dissemination of antibiotic-resistant bacteria from hospital compartments to the hospital sewage treatment plant was examined. METHODS AND RESULTS: A total of 1020 clinical isolates and 435 sewage isolates were collected between July and September 2005. The percentages of Gram-negative bacteria from the clinical and sewage isolates were 87.2% and 91.0%, respectively (P = 0.033). Escherichia coli were the leading bacterial isolates in both groups. Antimicrobial susceptibility testing showed a significant difference (P < 0.001) in resistance to ampicillin (85.6% vs 94.1%), ampicillin/sulbactam (31.7% vs 55.4%), cefazolin (29.2% vs 71.5%) and cefuroxime (20.7% vs 61.9%) between clinical and sewage coliform isolates, respectively. CONCLUSIONS: The sewage isolates had higher antimicrobial resistance rates than the clinical isolates from the same hospital. SIGNIFICANCE AND IMPACT OF THE STUDY: The low efficacy of the hospital sewage treatment may contribute to the dissemination of multidrug resistant bacteria from this hospital compartments to the environment. Practices which limit the disposal of antimicrobial agents into the wastewater system may be the possible measure to prevent the selection of multidrug-resistant bacteria from sewage treatment plants.


Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Infecções Bacterianas/microbiologia , Farmacorresistência Bacteriana Múltipla , Esgotos/microbiologia , Bactérias/isolamento & purificação , Hospitais de Ensino , Humanos , Taiwan
4.
Mol Cell Biol ; 20(20): 7813-25, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11003675

RESUMO

Using a yeast two-hybrid system, we isolated a novel human centrosomal protein, CPAP (centrosomal P4.1-associated protein), which specifically interacts with the head domain of the 135-kDa protein 4.1R isoform (4.1R-135). Sequence analysis revealed that the carboxyl terminus of CPAP has 31.3% amino acid identity with human Tcp-10 (a t-complex responder gene product). Interestingly, most of the sequence identity is restricted to two conserved regions. One carries a leucine zipper, which may form a series of heptad repeats involved in coiled-coil formation; the other contains unusual glycine repeats with unknown function. Immunofluorescence analysis revealed that CPAP and gamma-tubulin are localized within the centrosome throughout the cell cycle. CPAP cosediments with gamma-tubulin in sucrose gradients and coimmunoprecipitates with gamma-tubulin, indicating that CPAP is a part of the gamma-tubulin complex. Furthermore, functional analysis revealed that CPAP is localized within the center of microtubule asters and may participate in microtubule nucleation. The formation of microtubule asters was significantly inhibited by anti-CPAP antibody. Together, these observations indicate that CPAP may play an important role in cell division and centrosome function.


Assuntos
Centrossomo/química , Proteínas do Citoesqueleto , Proteínas de Membrana , Proteínas Associadas aos Microtúbulos/metabolismo , Neuropeptídeos , Proteínas/metabolismo , Tubulina (Proteína)/metabolismo , Sequência de Aminoácidos , Citosol/química , Biblioteca Gênica , Humanos , Microscopia de Fluorescência , Proteínas Associadas aos Microtúbulos/química , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/isolamento & purificação , Microtúbulos/metabolismo , Dados de Sequência Molecular , Testes de Precipitina , Ligação Proteica , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Proteínas/genética , RNA Mensageiro/metabolismo , Sequências Repetitivas de Aminoácidos , Alinhamento de Sequência , Análise de Sequência de DNA , Células Tumorais Cultivadas , Técnicas do Sistema de Duplo-Híbrido
5.
Free Radic Biol Med ; 24(7-8): 1130-8, 1998 May.
Artigo em Inglês | MEDLINE | ID: mdl-9626567

RESUMO

The major physiological role of glucose-6-phosphate dehydrogenase (G6PD) is to provide NADPH, which is required for reductive biosynthesis and for detoxification of free radicals and peroxides in mature red blood cells. To study the function of G6PD in non-erythroid cells, we examined the sensitivity of NIH3T3 cells transfected with a plasmid containing human G6PD cDNA to tert-butyl hydroperoxide (TBH) and paraquat. Two transfected clones which had a sixteen-fold (H7 clone) and six-fold (H6 clone) increase in their intracellular G6PD activity were compared with control cells transfected with a vector alone. Cells with high-level expression of human G6PD were 2.3 (H6) to 3.7 (H7) times more resistant to TBH than control cells. The antioxidant (anti-TBH) abilities in H6 and H7 cells were revealed by (1) a significant increase in the intracellular level of NADPH and glutathione, (2) a reduction of fluorescent intensity of the oxidant-sensitive dye, 2',7'-dichlorofluorescin diacetate, and (3) a significant reduction in the production of oxidized adducts generated by lipid peroxidation. In contrast, cells overexpressing G6PD were very sensitive to paraquat, a superoxide-producing herbicide. The concentrations of paraquat required to produce a 50% decrease in cell viability of H7, H6 and control cells were 0.80 mM, 1.14 mM, and 2.19 mM, respectively. The cytotoxicity of paraquat correlated with the expression level of NADPH in the cells. In this study, overexpression of human G6PD in NIH3T3 cells had different effects on the toxicity of TBH vs. paraquat. Reduction of NADP+ to NADPH by G6PD protects cells from oxidative damage by TBH, but appears to enhance the toxicity of paraquat.


Assuntos
Glucosefosfato Desidrogenase/genética , Glucosefosfato Desidrogenase/metabolismo , Paraquat/toxicidade , Peróxidos/toxicidade , Células 3T3 , Animais , Antioxidantes/metabolismo , Sobrevivência Celular/efeitos dos fármacos , DNA Complementar/genética , Expressão Gênica , Glutationa/metabolismo , Humanos , Peroxidação de Lipídeos/efeitos dos fármacos , Camundongos , NADP/metabolismo , Transfecção , terc-Butil Hidroperóxido
6.
J Immunol Methods ; 120(2): 151-7, 1989 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-2661691

RESUMO

Two novel immunization methods (intrasplenic and intra-inguinal lymph node) have been developed for the production of polyclonal and monoclonal antibodies in mice. Freund's complete adjuvant and antigen were mixed in the ratio of 1:2 (v/v). Various concentrations of human serum albumin (HSA) were used as antigen. No primary immune response was induced with 0.1 microgram of HSA in either of the methods studied. Intrasplenic immunization resulted in the strongest primary immune responses using all other doses of HSA. The primary immune response induced by intrasplenic immunization with 0.5 microgram of HSA was higher than any response induced by subcutaneous immunization with various doses of HSA. Inguinal lymph node immunization was less effective than intrasplenic immunization but better than subcutaneous immunization with 1-50 micrograms of HSA. Comparisons were also made of the efficacy of different adjuvants when inducing primary immune responses with 1 microgram of HSA. Freund's complete adjuvant resulted in a much stronger response than Freund's incomplete adjuvant and alum. Both intrasplenic and inguinal lymph node immunization using 1-5 micrograms of HSA were able to induce strong primary immune responses. Secondary immunization with either method or intravenous injection 3 days before fusion resulted in a higher frequency of specific monoclonal antibodies.


Assuntos
Anticorpos Monoclonais , Antígenos/administração & dosagem , Técnicas Imunológicas , Adjuvantes Imunológicos , Animais , Formação de Anticorpos , Especificidade de Anticorpos , Relação Dose-Resposta Imunológica , Hibridomas/microbiologia , Injeções Subcutâneas , Linfonodos/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Albumina Sérica/administração & dosagem , Albumina Sérica/imunologia , Baço/imunologia
7.
Chest ; 102(3): 783-5, 1992 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1516403

RESUMO

We report a pair of identical twins with HC with varying extent of left ventricular hypertrophy and some degree of left ventricular outflow tract obstruction. The diagnosis of identical twins was based on the same sex, blood typings, HLA typings and hybridization patterns to four hypervariable DNA probes. Identical twins are derived from a single zygote and are genetically homogeneous human beings. The present report suggests that heterogeneity in the morphologic expression of HC may not be solely attributed to genetic factors. Environmental factors also may play an important role.


Assuntos
Cardiomiopatia Hipertrófica/genética , Doenças em Gêmeos/genética , Gêmeos Monozigóticos/genética , Adulto , Cardiomiopatia Hipertrófica/diagnóstico por imagem , Ecocardiografia , Humanos , Masculino , Função Ventricular Esquerda/fisiologia , Obstrução do Fluxo Ventricular Externo/diagnóstico por imagem
8.
DNA Cell Biol ; 17(10): 823-33, 1998 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9809744

RESUMO

We have analyzed the general protein kinase expression profile in mouse sperm and eggs. A total of 41 different kinases were identified. In this study, we describe two novel protein kinases, designated AIE1 (mouse) and AIE2 (human), which share high amino acid identities with the serine/threonine (S/T) kinase domain of yeast Ip11, fly aurora, and frog Eg2. Mutations in Ip11 and aurora have been reported to cause abnormal chromosome segregation and centrosome separation. Both AIE1 and AIE2 contain a typical S/T kinase domain (251 aa) flanked by a short polypeptide at both ends. Two other AIE-related kinases (STK-1 and IAK1/Ayk1) were also identified in mature mouse oocytes. The central kinase domain of AIE1 revealed 77.6% and 66.3% identity with that of STK-1 and IAK1/Ayk1, but much less homology was found in the sequence outside the kinase domain. Northern blot analysis revealed that both AIE1 and AIE2 are specifically expressed in testis, whereas STK-1 and IAK1/Ayk1 are expressed in many tissues rich in proliferating cells. An in vitro kinase assay showed that AIE1 can phosphorylate casein, AIE1 itself, and an uncharacterized cellular protein (p16). The kinase activity of AIE1 can be destroyed by heat inactivation. In summary, we suggest that AIE is a new member of the S/T kinase family, which may be regulated in a fashion distinct from other AIE-related kinases.


Assuntos
Segregação de Cromossomos , Óvulo/enzimologia , Proteínas Quinases/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas Tirosina Quinases/genética , Espermatozoides/enzimologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular , Sequência Consenso , Drosophila/enzimologia , Feminino , Homeostase , Humanos , Masculino , Camundongos , Dados de Sequência Molecular , Especificidade de Órgãos , Filogenia , Biossíntese de Proteínas , Proteínas Quinases/biossíntese , Proteínas Quinases/química , Proteínas Serina-Treonina Quinases/biossíntese , Proteínas Serina-Treonina Quinases/química , Proteínas Tirosina Quinases/biossíntese , Proteínas Tirosina Quinases/química , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Saccharomyces cerevisiae/enzimologia , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Transcrição Gênica
9.
DNA Cell Biol ; 19(11): 679-88, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11098217

RESUMO

We previously reported two novel testis-specific serine/threonine kinases, Aie1 (mouse) and AIE2 (human), that share high amino acid identities with the kinase domains of fly aurora and yeast Ipl1. Here, we report the entire intron-exon organization of the Aie1 gene and analyze the expression patterns of Aie1 mRNA during testis development. The mouse Aie1 gene spans approximately 14 kb and contains seven exons. The sequences of the exon-intron boundaries of the Aie1 gene conform to the consensus sequences (GT/AG) of the splicing donor and acceptor sites of most eukaryotic genes. Comparative genomic sequencing revealed that the gene structure is highly conserved between mouse Aie1 and human AIE2. However, much less homology was found in the sequence outside the kinase-coding domains. The Aie1 locus was mapped to mouse chromosome 7A2-A3 by fluorescent in situ hybridization. Northern blot analysis indicates that Aie1 mRNA likely is expressed at a low level on day 14 and reaches its plateau on day 21 in the developing postnatal testis. RNA in situ hybridization indicated that the expression of the Aie1 transcript was restricted to meiotically active germ cells, with the highest levels detected in spermatocytes at the late pachytene stage. These findings suggest that Aie1 plays a role in spermatogenesis.


Assuntos
Genes/genética , Proteínas Serina-Treonina Quinases/genética , Sequência de Aminoácidos , Animais , Aurora Quinase C , Aurora Quinases , Sequência de Bases , Northern Blotting , Bandeamento Cromossômico , Mapeamento Cromossômico , DNA/química , DNA/genética , DNA/isolamento & purificação , Éxons , Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Hibridização In Situ , Hibridização in Situ Fluorescente , Íntrons , Masculino , Camundongos , Camundongos Endogâmicos , Dados de Sequência Molecular , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Alinhamento de Sequência , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Homologia de Sequência do Ácido Nucleico , Testículo/enzimologia , Testículo/crescimento & desenvolvimento
10.
Adv Exp Med Biol ; 241: 81-95, 1988.
Artigo em Inglês | MEDLINE | ID: mdl-3223413

RESUMO

Protein 4.1 in red cells is an important submembrane linking protein that binds to spectrin actin complexes at one end of its structure and to transmembrane proteins, such as glycophorin, at the other. Protein 4.1 thus contributes to the strength and flexibility of the erythrocyte membrane, a fact dramatically exemplified by the appearance of hereditary hemolytic anemias in patients with absent or abnormal protein 4.1. Recently, protein 4.1 forms have been discovered in many non-erythroid tissues. Their intracellular locations raise the possibility that these isoforms might have different functions. We have thus conducted comparative analysis of erythroid and non-erythroid protein 4.1 forms by cloning and sequencing erythroid and lymphoid protein 4.1 cDNAs. The lymphoid protein 4.1 isoforms exhibit at least five nucleotide sequence motifs that appear to be either inserted or deleted relative to the erythroid mRNA sequence by alternative splicing of a common mRNA precursor. One of these motifs, located within the spectrin-actin binding domain, is found only in erythroid cells and is specifically produced during erythroid cell maturation. The selective expression of this alternatively spliced mRNA during erythroid maturation implies the existence of a lineage specific splicing mechanism whose activity is triggered by terminal maturation. Two motifs alter the 5' untranslated region of the "prototypical" erythroid mRNA in such a way as to permit synthesis of a novel larger isoform. This form appears to localize preferentially in the nucleus. We thus conclude that a single gene gives rise to multiple protein 4.1 isoforms with potentially diverse locations and functions.


Assuntos
Proteínas do Citoesqueleto , Eritrócitos/fisiologia , Linfócitos/fisiologia , Proteínas de Membrana/genética , Neuropeptídeos , Sequência de Bases , Clonagem Molecular , DNA/genética , Regulação da Expressão Gênica , Humanos , Dados de Sequência Molecular , Biossíntese de Proteínas , RNA Mensageiro/genética , Homologia de Sequência do Ácido Nucleico
11.
Ann Nucl Med ; 5(3): 83-7, 1991 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1764343

RESUMO

Radioiodination of synthetic human secretin on its N-terminal histidyl residue was not difficult when a greater amount of Chloramine T and a longer reaction time were employed to achieve better incorporation of 125I. The radioiodinated tracer for an optimal radioimmunoassay required purification. The combination of Sep-pak C18 Cartridge and high performance liquid chromatography for the purification of 125I-secretin in our study revealed that the Sep-pak cartridge was a preliminary step in removing unlabeled radioactive iodide, the reactant, and labeled materials unadsorbed to the cartridge. The eluate eluted from the Sep-pak containing high radioactivity and high immunoreactivity to the antibody were selected for further purification by HPLC which eliminated undesirable radiolabeled substances with lower immunoreactivity. The purified radiolabeled secretin was used in developing a sensitive radioimmunoassay.


Assuntos
Radioisótopos do Iodo , Marcação por Isótopo/métodos , Secretina , Humanos , Técnicas In Vitro , Radioimunoensaio
12.
Chin Med J (Engl) ; 111(5): 416-21, 1998 May.
Artigo em Inglês | MEDLINE | ID: mdl-10374350

RESUMO

OBJECTIVE: Familial hypertrophic cardiomyopathy (FHCM) is a primary myocardial disease characterized by unexplained ventricular hypertrophy. The application of the techniques of reverse genetics has identified at least five chromosomal loci as the major causes for FHCM in diverse ethnic populations, suggesting substantial genetic heterogeneity for FHCM. Recently, the defective gene loci of two Chinese families with FHCM have been mapped to chromosome 11 and 14q1, respectively. For further understanding of the molecular basis of FHCM in Chinese, we analyzed the linkage between four other Chinese kindreds and DNA markers from chromosome 14q1. METHODS: Six unrelated Chinese families with FHCM, including two previously reported, were studied. Totally 90 family members were included for analysis. DNA from 80 individuals was extracted and polymerase chain reactions were performed using the primers designed according to the sequences derived from the alpha and beta myosin heavy chain gene. Totally four polymorphisms were studied, including three polymorphic microsatellite sequences and one single strand conformation polymorphism. Genetic linkage analysis were performed using the Linkage program. RESULTS: In the six studied families, 39 of the 90 family members were found to be affected diagnosed either by echocardiography or by clinical evaluation. The pattern of inheritance in all six studied families was most consistent with an autosomal dominant trait with a high degree of penetrance. Genetic linkage analysis using polymorphisms on the alpha and beta MHC genes showed a combined maximal lod score of 6.2 for trinucleotide repeat polymorphism AMHC-I 15 at theta = 0.00 for three studied families without recombination. Exclusion of linkage to the chromosome 14q1 location was noted in two of three other families with the maximal lod score of -2 or less. CONCLUSIONS: These results provide further evidence that FHCM in Chinese is genetically heterogeneous. Chromosome 14q1 locus, probably the beta myosin heavy chain gene, is important as the molecular basis for FHCM in Chinese.


Assuntos
Cardiomiopatia Hipertrófica/genética , Heterogeneidade Genética , Mutação de Sentido Incorreto , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Substituição de Aminoácidos , Povo Asiático , China , Cromossomos Humanos Par 14 , Saúde da Família , Feminino , Ligação Genética , Humanos , Masculino , Pessoa de Meia-Idade , Cadeias Pesadas de Miosina/genética , Linhagem
13.
J Formos Med Assoc ; 96(10): 779-83, 1997 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9343976

RESUMO

Mature, circulating mammalian erythrocytes have a finite lifespan. The molecular mechanism that determines removal of cells from the circulation remains unknown, but probably involves recognition of senescence antigens by phagocytes, either directly or via an antibody/complement-mediated pathway. It has been proposed that the major senescence antigen in aged erythrocytes is derived from the band 3 protein, the main transmembrane glycoprotein in erythrocytes. Other possible mechanisms for red cell aging include mechanical fatigue, ATP depletion, calcium accumulation, and the generation of reactive oxygen species (ROS). ROS, which damage proteins and initiate lipid peroxidation, can be generated either inside erythrocytes through the hemoglobin oxidation pathway or outside (eg, by stimulated macrophages). The ROS theory of red cell aging has been widely accepted, yet it lacks direct supporting evidence. To test this hypothesis, two critical techniques have been established in this laboratory. First, we determine the lifespan of erythrocytes in vivo using a fluorescent cell labeling technique. Second, transgenic mice have been produced which express high levels of the human antioxidant enzymes, superoxide dismutase and glucose-6-phosphate dehydrogenase, in their erythrocytes. These two techniques will be very useful for the evaluation of the free radical theory of red cell aging.


Assuntos
Envelhecimento Eritrocítico , Espécies Reativas de Oxigênio/metabolismo , Animais , Radicais Livres , Humanos , Camundongos , Camundongos Transgênicos
14.
J Formos Med Assoc ; 96(12): 948-54, 1997 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9444913

RESUMO

Glucose 6-phosphate dehydrogenase (G6PD) deficiency is a common genetic disease affecting 3% of the total Chinese population in Taiwan. To investigate the molecular basis of this deficiency, we analyzed blood samples from G6PD-deficient newborns using a nonradioactive polymerase chain reaction coupled with single-stranded conformation polymorphism (PCR-SSCP) analysis. We identified two novel G6PD mutations in Chinese. The first, G6PD Miaoli, involved a C-->G substitution at nucleotide (nt) 519, producing a Phe173 to Leu change in the protein. The second mutation (G6PD Keelung) involved a C-->T change at nt 1387, resulting in an Arg463 to Cys substitution. The F8C/G6PD (coagulation factor VIIIc) haplotype that spans the Xq28 region from the gene for coagulation factor VIIIc to the gene for G6PD was also investigated in Chinese using PCR and restriction enzyme digestion. Of the 16 possible haplotypes, only four were found, which suggests that these four polymorphic sites are in strong linkage disequilibrium. Analysis of the association of G6PD mutations with F8C/G6PD haplotype revealed that nt 517, 592, 835, and 1387 mutations are linked to haplotype VI+VII, whereas the nt 519 mutation is linked to haplotype III. The finding that some G6PD mutations are associated with a particular F8C/G6PD haplotype may be useful for future population studies.


Assuntos
Deficiência de Glucosefosfato Desidrogenase/genética , Glucosefosfato Desidrogenase/genética , Haplótipos , Mutação , Feminino , Humanos , Masculino
15.
J Formos Med Assoc ; 96(2): 73-82, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9071831

RESUMO

A rapid and simple method using restriction enzymes to detect the restriction fragment length polymorphism (RFLP) pattern of hypervariable segment 1 in the D-loop region of human mitochondrial DNA (mtDNA) was developed. We first focused on the investigation of variations of DNA sequence in the D-loop region among Chinese subjects, as well as on the determination of RFLP patterns of each restriction enzyme. Seven restriction enzymes were used to digest a 618 bp polymerase chain (PCR) reaction product of the D-loop region of mtDNA. Frequency distribution of RFLP patterns of each restriction enzyme among 145 unrelated Chinese subjects in Taiwan was also established. For the purposes of practical forensic application, a routine typing system was designed on the basis of the RFLP data. Two short hypervariable, mtDNA fragments, which were contained within the 618 bp region, were selected for this purpose. In this haplotyping system, a 281 bp PCR-amplified DNA product was analyzed by five restriction enzymes: Mnl I, Nla III, Rsa l, Mse I and Hinf I, and a 237 bp fragment was analyzed by Kpn I. The RFLP patterns were determined by agarose gel electrophoresis of the restriction enzyme-digested DNA fragments. Six restriction enzymes. Mul I, Nla III, Rsa I. Msc I, Hinf I and Kpn 1, defined eight, four, four, five, two and four polymorphic patterns, respectively among the 145 Chinese subjects. The RFLP patterns of restriction fragments for each individual were systematically analyzed and the mtDNAs of the 145 Chinese subjects were grouped into 52 haplotypes. This PCR-RFLP haplotyping system revealed a high degree of variability and diversity of segment I in the D-loop region of human mtDNA. The power of discrimination and allelic diversity values were 0.923 and 0.929, respectively. Successful application of this haplotyping system in a murder case is also discussed.


Assuntos
DNA Mitocondrial/genética , Medicina Legal , Haplótipos , Reação em Cadeia da Polimerase , Feminino , Humanos , Masculino , Polimorfismo de Fragmento de Restrição
16.
J Formos Med Assoc ; 95(1): 69-72, 1996 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8640101

RESUMO

In forensic DNA typing, evidential samples generally involve limited amounts of DNA and so should be carefully utilized. Although polymerase chain reaction (PCR) of variable number of tandem repeats (VNTR) alleles is the prevailing method for forensic identification, the fidelity of amplification of heterozygous VNTR alleles with large disparities in length needs to be carefully examined. Reports in the literature and our own observations have demonstrated that PCR artifacts, bogus alleles and allelic drop-out of VNTRs, are related to the amount of genomic DNA, the number of amplification cycles and the length of alleles amplified. Two small (< 1 kb) hypervariable VNTRs (Apo B and HVR-Ig) markers used for forensic identification were chosen to study these relationships. The results revealed that PCR amplification for the heterozygous VNTR alleles with wide disparity in length (> 400 bp) easily produced the allelic drop-out problem and therefore, led to the false results; and the allelic fragment of PCR products was preferentially lost after only 2 cycles of overamplification. We also further established the relationship between the optimal number of amplification cycles and the amount of genomic DNA in the reaction mixture. In our routine forensic screening this relationship has been successfully applied to determine the optimal number of amplification cycles and to avoid the allelic drop-out problem and achieve fidelity of PCR-VNTR amplification. It has also been used to investigate forensic casework.


Assuntos
Alelos , Repetições Minissatélites/genética , Técnicas de Amplificação de Ácido Nucleico , Reação em Cadeia da Polimerase/métodos , Apolipoproteínas B/genética , Sequência de Bases , DNA/genética , Reações Falso-Negativas , Reações Falso-Positivas , Humanos , Região Variável de Imunoglobulina/genética , Dados de Sequência Molecular
17.
J Formos Med Assoc ; 91(1): 9-14, 1992 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-1352342

RESUMO

The optimal sensitivity of a radioimmunoassay depends on the purity of the radiolabeled antigen. The conventional purification methods are not complete and are time consuming. The combination of a Sep-pak C18 cartridge and high performance liquid chromatography (HPLC) for the purification of 125I-labeled insulin in our study revealed that the Sep-pak cartridge can serve as the preliminary step to remove unreacted radioactive iodide, the reactants, and labeled but presumably damaged materials unadsorbed to the cartridge. The fractions eluted from the Sep-pak containing high radioactivity and high immunoreactivity to the antibody were chosen for further purification by HPLC to eliminate undesirable radiolabeled substances with a lesser immunoreactivity. The purified radiolabeled insulin was used to develop a sensitive radioimmunoassay with detecting limits of 0.03 microU/mL per tube.


Assuntos
Insulina/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Humanos , Insulina/análise , Insulina/imunologia , Radioisótopos do Iodo , Marcação por Isótopo , Radioimunoensaio
18.
Chin J Physiol ; 35(1): 55-65, 1992.
Artigo em Inglês | MEDLINE | ID: mdl-1330453

RESUMO

The effects of estradiol and thyroxine (T4) on the spontaneous and thyrotropin-releasing hormone (TRH)-stimulated release of thyroid-stimulating hormone (TSH) and prolactin (PRL) in vitro from rat anterior pituitary glands (APs) were studied. Rats were ovariectomized (Ovx) and thyroidectomized (Tx) following injection of either thyroxine (20 micrograms/kg, sc) or saline and either estradiol benzoate (EB, 0.4 micrograms/kg, sc) or peanut oil daily for 42 days. Twenty hours after the last injection, all rats were decapitated. The blood samples were collected and the APs were bisected and incubated with or without TRH (1 or 1000 ng/ml) at 37 degrees C for 4 h. Serum TSH concentration was reduced by T4 injection but not altered by EB replacement. The concentration of serum PRL was increased by EB. Injection of both T4 and EB reduced the serum PRL level as compared with the PRL levels in Ovx-Tx rats injected with T4 or EB alone. The spontaneous release of TSH in vitro from APs of OVx-Tx rats was not altered by the replacement of T4, EB, or both. The TSH response to TRH (1000 ng/ml) was not influenced by EB treatment, but higher in T4-treated than in vehicle-treated group. Injection of both EB and T4 prevented the stimulatory effect of T4 alone on TSH response. Both spontaneous and TRH-stimulated releases of PRL in vitro were enhanced by EB injection. Administration of T4 did not affect the basal release of PRL, but stimulated the PRL response to TRH (1000 ng/ml). Injection of EB plus T4 caused a higher PRL response to TRH as compared with that in the rats injected with EB or T4 alone. These results suggest an antagonistic interaction between estradiol and thyroxine on the in vitro release of TSH in response to TRH and a synergetic interaction between these two hormones on PRL response to TRH. The interaction between estradiol and thyroxine on serum prolactin and TSH levels was not reflected by the interaction between these two hormones on the anterior pituitary gland.


Assuntos
Estradiol/farmacologia , Prolactina/metabolismo , Tireotropina/metabolismo , Tiroxina/farmacologia , Animais , Feminino , Técnicas In Vitro , Hormônio Luteinizante/sangue , Ovariectomia , Ratos , Ratos Endogâmicos , Receptores de Neurotransmissores/efeitos dos fármacos , Receptores do Hormônio Liberador da Tireotropina , Tireoidectomia
19.
J Forensic Sci ; 40(2): 228-35, 1995 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-7602283

RESUMO

The detection of genetic polymorphism has become increasingly important in forensic science as well as in medical genetics. In this report, we describe a systematic flow chart system for HLA-DQA1 genotyping by an improved PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism) method coupled with the PRSM (PCR-mediated restriction site modification) method. This flow chart typing system can easily discriminate between a total of eight reported DQA1 alleles commonly found in Chinese. We have applied this flow chart typing system in a forensic case as well as in the determination of the frequencies of the eight DQA1 alleles in 121 unrelated Taiwan Chinese subjects. Our results show that the flow chart DQA1 genotyping is a simple, fast, and accurate system which, in the future, may be considered as an alternative method for routine individual identification in forensic casework, and for paternity testing and tissue typing in medical genetics.


Assuntos
Povo Asiático/genética , DNA/análise , Medicina Legal/métodos , Antígenos HLA-DQ/genética , Alelos , Sequência de Bases , Genótipo , Cadeias alfa de HLA-DQ , Cabelo/química , Humanos , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Taiwan
20.
J Physiol Pharmacol ; 64(5): 535-43, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24304567

RESUMO

The purpose of the present study was to explore the effect of arecoline on phytohemagglutinin (PHA)-stimulated interleukin-2 (IL-2) secretion, the expression of alpha7-nicotinic acetylcholine receptors (α7-nAChRs), prostaglandin E2(PGE2) protein, and IL-2 mRNA in human lymphocyte cells (Jurkat cell line). The IL-2 and PGE2 were determined by enzyme-linked immunosorbent assay (ELISA). The expressions of phosphorylated extracellular signal-regulated kinase (ERK) and α7-nAChRs were determined by Western blotting. The level of IL-2 mRNA was determined by reverse-transcriptase polymerase chain reaction (RT-PCR). Arecoline, in a dose-dependent manner, significantly decreased IL-2 and PGE2 secretion by Jurkat cells incubated with 0 or 5 µg/ml 5 µg/ml PHA. PGE2 also significantly inhibited IL-2 secretion by Jurkat cells in a dose-dependent manner. In addition, reduced expression of PHA-induced ERK phosphorylation was observed in Jurkat cells treated with arecoline. PHA-enhanced IL-2 mRNA expression was also inhibited by arecoline. These results imply that arecoline inhibits the release of PGE2 and PHA-induced IL-2 secretion by Jurkat cells and that these effects seem to occur, at least in part, either through the attenuation of ERK in conjunction with a decrease of PHA-induced IL-2 mRNA expression. These results imply that arecoline inhibits the protein expression of α7-nAChRs , the release of PGE2 and PHA-induced IL-2 secretion by Jurkat cells.


Assuntos
Arecolina/farmacologia , Dinoprostona/metabolismo , Interleucina-2/antagonistas & inibidores , Receptor Nicotínico de Acetilcolina alfa7/metabolismo , Proliferação de Células/efeitos dos fármacos , Humanos , Interleucina-2/genética , Interleucina-2/metabolismo , Células Jurkat , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Fosforilação/efeitos dos fármacos , Fito-Hemaglutininas , RNA Mensageiro/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA