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H Tai

Publications and source records attributed to H Tai.

At least 19 recordsLinked to original sources
PubMed2004

Polymorphisms in the IL-6 receptor (IL-6R) gene: strong evidence that serum levels of soluble IL-6R are genetically influenced.

We have investigated the association of the recently identified IL6R polymorphisms with the serum levels of soluble IL-6 receptor (sIL-6R). sIL-6R is generated by shedding of the membrane-bound receptor (IL-6Ralpha) or alternative mRNA splicing. In total, 115 healthy volunteers were genotyped, with 70 of them analyzed for sIL-6R levels. Using the PCR/RFLP methods, two important polymorphic sites were selected for genotyping: the 48892A/C (D358A) in exon 9 and the -183G/A in the promoter region. In exon 9, C allele carriers had higher sIL-6R level (P<0.0001) showing that this sequence variation, which corresponds to the proteolytic cleavage site of IL-6Ralpha, strongly influences the serum sIL-6R levels. In the promoter region, G allele carriers had lower sIL-6R levels (P<0.0082) compared with the A allele carriers. This could be attributed to the linkage disequilibrium (D'=0.54, chi2=51.3, P<0.0001) between the -183G/A and the 48892A/C gene polymorphisms.

Adult↗
PubMed2003

Single-nucleotide polymorphism in the CD14 promoter and periodontal disease expression in a Japanese population.

It has been reported that there is a relationship between a single-nucleotide polymorphism (SNP) in the promoter region of the CD14 gene at position -159 (C-->T) and infectious diseases. The aim of the present study was to test the hypthesis that expression of this SNP correlates with periodontal disease in a Japanese population. The CD14 genotype was determined in 163 subjects with periodontitis and in 104 age- and gender-matched control subjects without periodontitis. The genotype distribution and allele frequency within the periodontitis patients were not significantly different from those of control subjects. There was, however, a significant difference in the genotype distribution between young patients (< 35 yrs) and older patients (>/==" BORDER="0"> 35 yrs). These findings suggest that CD14 -159C/T polymorphism is not related to the development of periodontitis in a Japanese population, but that, within the periodontitis subjects, expression of the SNP may be related to early disease activity.

Adult↗
PubMed2002

A simple model for straggling evaluation.

Some straggling models had largely been abandoned in favor of Monte Carlo simulations of straggling which are accurate but time consuming, limiting their application in practice. The difficulty of simple analytic models is the failure to give accurate values past 85% of the particle range. A simple model is derived herein based on a second order approximation upon which rapid analysis tools are developed for improved understanding of material charged particle transmission properties.

Alpha Particles↗
PubMed2001

Overexpression of 3-ketoacyl-acyl-carrier protein synthase IIIs in plants reduces the rate of lipid synthesis.

A cDNA coding for 3-ketoacyl-acyl-carrier protein (ACP) synthase III (KAS III) from spinach (Spinacia oleracea; So KAS III) was used to isolate two closely related KAS III clones (Ch KAS III-1 and Ch KAS III-2) from Cuphea hookeriana. Both Ch KAS IIIs are expressed constitutively in all tissues examined. An increase in the levels of 16:0 was observed in tobacco (Nicotiana tabacum, WT-SR) leaves overexpressing So KAS III when under the control of the cauliflower mosaic virus-35S promoter and in Arabidopsis and rapeseed (Brassica napus) seeds overexpressing either of the Ch KAS IIIs driven by napin. These data indicate that this enzyme has a universal role in fatty acid biosynthesis, irrespective of the plant species from which it is derived or the tissue in which it is expressed. The transgenic rapeseed seeds also contained lower levels of oil as compared with the wild-type levels. In addition, the rate of lipid synthesis in transgenic rapeseed seeds was notably slower than that of the wild-type seeds. The results of the measurements of the levels of the acyl-ACP intermediates as well as any changes in levels of other fatty acid synthase enzymes suggest that malonyl-ACP, the carbon donor utilized by all the 3- ketoacyl-ACP synthases, is limiting in the transgenic plants. This further suggests that malonyl-coenzyme A is a potential limiting factor impacting the final oil content as well as further extension of 16:0.

3-Oxoacyl-(Acyl-Carrier-Protein) Synthase↗
PubMed2001

Analysis of single nucleotide polymorphisms in the 5'-flanking region of tumor necrosis factor-alpha gene in Japanese patients with early-onset periodontitis.

BACKGROUND: Early-onset periodontitis (EOP) is considered to have a genetic basis, which has not been clearly defined. The tumor necrosis factor-alpha (TNF-alpha) gene polymorphism as one of the genetic factors may influence the expression of several chronic inflammatory diseases. The aim of the present study was to evaluate whether the polymorphisms in the 5'-flanking region of the TNF-alpha gene are associated with Japanese EOP patients. METHODS: Forty-six Japanese, generalized EOP (G-EOP) patients and 104 Japanese healthy subjects were identified according to established clinical criteria. Twenty healthy subjects were analyzed by nucleotide sequence to screen polymorphisms of the 5'-flanking region of the TNF-alpha gene. Then, all subjects were analyzed by polymerase chain reaction and sequence-specific oligonucleotide probe (SSOP) methods. RESULTS: We determined 5 single nucleotide polymorphisms at positions -1031 (T/C), -863 (C/A), -857 (C/T), -308 (G/A), and -238 (G/A) in the 5'-flanking region of the TNF-alpha gene. There were no significant differences in the genotype and allele frequency when we compared G-EOP patients to healthy subjects. Because the frequency of polymorphic alleles at positions -308 and -238 was very low in this study population, we demonstrated the existence of 4 detected haplotypes and 6 detected genotypes concerning 3 single nucleotide polymorphisms (-1031, -863, and -857). The frequency of the H1/H3 (TCC/TCT)-detected genotype tended to decrease in G-EOP patients compared to healthy subjects, but was not statistically significant. CONCLUSION: These findings suggest there is no significant association between polymorphisms in the 5'-flanking region of the TNF-alpha gene and susceptibility to G-EOP in Japanese patients.

5' Flanking Region↗
PubMed2000

Involvement of nuclear receptor coactivator SRC-1 in estrogen-dependent cell growth of MCF-7 cells.

Steroid hormones regulate cell growth and function through the transcriptional control of target genes by their cognate nuclear receptors. These receptors bind to ligands and associate with transcriptional cofactors to stimulate transcription. SRC-1, one of the nuclear receptor coactivators, is known to interact with nuclear receptors and enhance transactivation function in a ligand-dependent manner. In this study, to assess the function of SRC-1 in cell growth regulated by nuclear receptor ligands, we established a stable transformant cell line overexpressing human SRC-1 and studied the action of 17beta-estradiol (E(2)) on cell growth as well as the expression of E(2)-responsive genes in MCF-7 cells. We found that SRC-1 overexpression potentiates cell growth stimulated by E(2) in accordance with enhancement of transcriptional activation of exogenous and endogenous E(2)-responsive genes. These findings clearly indicate the importance of nuclear receptor coactivators for the activities of steroid/lipophilic vitamins in cell growth and gene expression.

Adenocarcinoma↗
PubMed1999

Purification and identification of p68 RNA helicase acting as a transcriptional coactivator specific for the activation function 1 of human estrogen receptor alpha.

The estrogen receptor (ER) regulates the expression of target genes in a ligand-dependent manner. The ligand-dependent activation function AF-2 of the ER is located in the ligand binding domain (LBD), while the N-terminal A/B domain (AF-1) functions in a ligand-independent manner when isolated from the LBD. AF-1 and AF-2 exhibit cell type and promoter context specificity. Furthermore, the AF-1 activity of the human ERalpha (hERalpha) is enhanced through phosphorylation of the Ser(118) residue by mitogen-activated protein kinase (MAPK). From MCF-7 cells, we purified and cloned a 68-kDa protein (p68) which interacted with the A/B domain but not with the LBD of hERalpha. Phosphorylation of hERalpha Ser(118) potentiated the interaction with p68. We demonstrate that p68 enhanced the activity of AF-1 but not AF-2 and the estrogen-induced as well as the anti-estrogen-induced transcriptional activity of the full-length ERalpha in a cell-type-specific manner. However, it did not potentiate AF-1 or AF-2 of ERbeta, androgen receptor, retinoic acid receptor alpha, or mineralocorticoid receptor. We also show that the RNA helicase activity previously ascribed to p68 is dispensable for the ERalpha AF-1 coactivator activity and that p68 binds to CBP in vitro. Furthermore, the interaction region for p68 in the ERalpha A/B domain was essential for the full activity of hERalpha AF-1. Taken together, these findings show that p68 acts as a coactivator specific for the ERalpha AF-1 and strongly suggest that the interaction between p68 and the hERalpha A/B domain is regulated by MAPK-induced phosphorylation of Ser(118).

Adenocarcinoma↗
PubMed1999

[pncA gene mutations in clinical isolates of tubercle bacillus by polymerase chain reaction-direct sequencing method: in relationship to pyrazinamide resistance].

We screened clinical isolates of tubercle bacillus for mutations in the pncA gene, which encodes pyrazinamidase (PZase), by polymerase chain reaction (PCR)-direct sequencing method. Sixty-eight strains of tubercle bacillus were isolated from 32 patients with pulmonary tuberculosis. The patients were treated with antituberculous agents including pyrazinamide (PZA) for 2 months. Thirty-two of the 68 strains were isolated from sputum samples collected from the patients before treatment; 29 strains and 7 strains were collected after 1 month and 2 months of treatment, respectively. The pncA genes in these strains, were assessed for mutations by direct sequencing of PCR products using an automated sequencer. Similarly, we examined two clinical isolates (ka567 and minami22) of tubercle bacillus, determined to be deficient in PZase activity by the Wayne method. A PZA-sensitive strain (H37Rv, ATCC27294), and a PZA-resistant strain (H37Rv-PZA-R, ATCC35828) were used as negative and positive controls for mutations in the pncA gene, respectively. None of the 68 strains demonstrated any mutations in the pncA gene; however, the 2 PZase-deficient strains had missense mutations in the pncA gene resulting in an amino acid substitution from His82 to Arg in clone ka567, and from Ala171 to Val in clone minami22.

Adult↗
PubMed1998

Transport of light ions in matter.

A recent set of light ion experiments are analyzed using the Green's function method of solving the Boltzmann equation for ions of high charge and energy (the GRNTRN transport code) and the NUCFRG2 fragmentation database generator code. Although the NUCFRG2 code reasonably represents the fragmentation of heavy ions, the effects of light ion fragmentation requires a more detailed nuclear model including shell structure and short range correlations appearing as tightly bound clusters in the light ion nucleus. The most recent NUCFRG2 code is augmented with a quasielastic alpha knockout model and semiempirical adjustments (up to 30 percent in charge removal) in the fragmentation process allowing reasonable agreement with the experiments to be obtained. A final resolution of the appropriate cross sections must await the full development of a coupled channel reaction model in which shell structure and clustering can be accurately evaluated.

Carbon↗
PubMed1998

[Msp I and Rsa I RFLPs of vWF gene in Chinese Han people].

OBJECTIVE: To study the Msp I and Rsa I restriction fragment length polymorphisms (RFLPs) in the 5' region of human von Willebrand factor gene in Chinese Han people. METHODS: A 226 bp amplified fragment of human vWF gene from 52 unrelated individuals and a 322 bp amplified fragment from 48 individuals were analyzed by Msp I or Rsa I digestion. RESULTS: Complete linkage disequilibrium was observed at both Msp I and Rsa I sites in vWF gene in Chinese Han people. The frequencies at the two sites were 0.20/0.80 for Msp I+/Msp I- and 0.93/0.07 for Rsa I+/Rsa I-. The theoretical heterozygous rates were 36% and 10%, respectively. CONCLUSION: The Msp I and Rsa I RELPs of vWF gene are useful for genetic counseling and prenatal diagnosis of vWD in Chinese Han people.

Alleles↗
PubMed1998

Sma I, Hha I, Msp I and Rsa I restriction fragment length polymorphisms in the von Willebrand factor gene of Chinese population.

OBJECTIVE: To study Sma I, Hha I, Msp I and Rsa I restriction fragment length polymorphisms in vWF gene of Chinese population. METHODS: The vWF gene from 52 unrelated individuals of Han Nationality, 44 of Yi tribe, 42 of Dai tribe was analyzed by polymerase chain reaction and digestion of the endonucleases of Sma I, Hha I, Msp I and Rsa I. RESULTS: The allele frequencies were 0.38:0.62 for Sma I+:Sma I- and 0.38:0.62 for Hha I+:Hha I-; 0.20:0.80 for Msp I+:Msp I-; 0.93:0.07 for Rsa I+:Rsa I- in Chinese Han population. The theoretical heterozygous rates were 0.46, 0.46, 0.36 and 0.13 of these polymorphisms, respectively. The allele frequencies were 0.43:0.57 for Sma I+:Sma I- and 0.43:0.57 for Hha I+:Hha I-, 0.26:0.74 for Msp I+:Msp- in Yi tribe and 0.36:0.64 for Sma I+:Sma I- and Hha I+:Hha I-, 0.17:0.83 for Msp I+:Msp I- in Dai tribe. The theoretical rates were 0.49 for Sma I and Hha I and 0.38 for Msp I in Yi tribe; and 0.45 for Sma I and Hha I, 0.28 for Msp I in Dai tribe, respectively. CONCLUSIONS: The allele frequencies and theoretical rates of these polymorphisms in vWF gene are different between Chinese populations and Caucasians. They should be useful for the carrier detection and prenatal diagnosis in vWD families of Chinese.

Alleles↗
PubMed1997

Structure--activity studies for alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropanoic acid receptors: acidic hydroxyphenylalanines.

Antagonists of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropanoic acid (AMPA) receptors may have therapeutic potential as psychotropic agents. A series of mononitro- and dinitro-2- and 3-hydroxyphenylalanines was prepared, and their activity compared with willardiine, 5-nitrowillardiine, AMPA, and 2,4,5-trihydroxyphenylalanine (6-hydroxydopa) as inhibitors of specific [3H]AMPA and [3H]kainate binding in rat brain homogenates. The most active compounds were highly acidic (pKa 3-4), namely, 2-hydroxy-3,5-dinitro-DL-phenylalanine (13; [3H]AMPA IC50 approximately equal to 25 microM) and 3-hydroxy-2,4-dinitro-DL-phenylalanine (19; [3H]AMPA IC50 approximately equal to 5 microM). Two other dinitro-3-hydroxyphenylalanines, and 3,5-dinitro-DL-tyrosine, were considerably less active. Various mononitrohydroxyphenylalanines, which are less acidic, were also less active or inactive, and 2- and 3-hydroxyphenylalanine (o- and m-tyrosine) were inactive. Compounds 13 and 19, DL-willardiine (pKa 9.3, [3H]AMPA IC50 = 2 microM), and 5-nitro-DL-willardiine (pKa 6.4, [3H]AMPA IC50 = 0.2 microM) displayed AMPA >> kainate selectivity in binding studies. Compound 19 was an AMPA-like agonist, but 13 was an antagonist in an AMPA-evoked norepinephrine release assay in rat hippocampal nerve endings. Also, compound 13 injected into the rat ventral pallidum antagonized the locomotor activity elicited by systemic amphetamine.

Animals↗
PubMed1997

Characterization of HIV-related periodontitis in AIDS patients: HIV-infected macrophage exudate in gingival crevicular fluid as a hallmark of distinctive etiology.

In an attempt to clarify the immunobiological events featuring periodontitis lesions of AIDS patients in the late stage of the disease, peripheral blood (PB) and gingival crevicular fluid (GCF) leucocytes from periodontitis lesions of 23 late-stage AIDS patients were analysed by three-colour flow cytometry for detection and identification of intracytoplasmic p24+ cell fractions. The cells were reacted with CD14 and CD68 for mononuclear phagocytes or with CD4 and CD14 for Th cells, then with anti-p24 MoAb. To detect HIV proviral sequences and intracellular p24 RNA sequences, genomic DNA and cellular RNA from leucocytes were extracted for semi-nested polymerase chain reaction (PCR) amplification. CD68+/p24+ and CD14+/CD68+/p24+ fractions were larger in GCF than in PB (P<0.0001; P < 0.003). CD14+/p24+ fraction was lower in GCF than in PB (P < 0.05). The fluorescence intensities (FI) for intracellular p24 in CD68+ and CD14+/CD68+ cells were higher in GCF than in PB (P < 0.003; P < 0.02), whereas those of CD14+ macrophages did not differ. The p24 FI of CD68+ macrophages in GCF correlated with CD4+ lymphocyte counts in PB (P < 0.005). p24 FI levels of CD14+ monocytes in GCF and PB significantly correlated (P < 0.02), whereas that of CD68+ macrophages did not. PCR and reverse transcriptase (RT)-PCR of cellular DNA and RNA yielded positive signals, demonstrating viral integration and production in GCF leucocytes. These results show that periodontitis lesions in AIDS patients can be characterized by a rapid macrophage turnover, and these HIV-infected macrophage exudates in GCF may be considered as a within-mouth source of virus.

Acquired Immunodeficiency Syndrome↗
PubMed1997

Transcriptional induction of cyclooxygenase-2 in osteoblasts is involved in interleukin-6-induced osteoclast formation.

Interleukin-6 (IL-6) induces osteoclast-like cell (osteoclast) formation in a dose-dependent fashion in cocultures of mouse bone marrow cells and osteoblastic cells when soluble IL-6 receptor (sIL-6R) is present. Simultaneous treatment with submaximal doses of IL-1alpha and IL-6 with sIL-6R caused marked induction of osteoclast formation and PGE2 synthesis. These effects were suppressed by adding neutralizing antibodies against IL-1alpha or IL-6R and were totally abolished by adding nonsteroidal antiinflammatory drugs, such as indomethacin and a selective cyclooxygenase-2 (COX-2) inhibitor (NS398). In mouse osteoblastic cells, both IL-1alpha and IL-6 with sIL-6R markedly induced messenger RNA expression of COX-2, but not COX-1, as determined by Northern blot analysis, and luciferase activity in cells stably transfected with a COX-2 promoter-luciferase fusion construct. IL-6 and sIL-6R, when added separately, did not stimulate COX-2 messenger RNA expression. Simultaneous addition of IL-1alpha and IL-6 with sIL-6R to osteoblast cultures cooperatively induced transcription of COX-2, which was associated with a marked increase in COX activity measured by the conversion of arachidonic acid into PGE2. The increased PGE2 synthesis by osteoblasts may play an important role in osteoclastogenesis induced by submaximal doses of IL-1 and IL-6.

Aging↗
PubMed1997

[Relationship between the activity of serum adenosine deaminase including its isozymes and lymphocyte subpopulation in patients with pulmonary tuberculosis].

Adenosine deaminase (ADA) is one of the enzymes in the purine metabolism and divided into two isozymes, ADA-1 and ADA-2. It is known that the activity of this enzyme is elevated in the sera of patients with pulmonary tuberculosis, sarcoidosis and other diseases, however there are few reports about the change of the activity of this enzyme under treatment. It is often said that this enzyme may have its origin in T lymphocyte, but it remains to be proved. That goes for each of two isozymes, too. In this study, we investigated the activity of serum total ADA, ADA-1 and ADA-2 in patients with pulmonary tuberculosis on admission and after three months' treatment. We also studied the correlation of lymphocyte subpopulation with these enzymes. The activity of total ADA, ADA-1 and ADA-2 was significantly higher in the sera of patients with pulmonary tuberculosis than in those of healthy persons. ADA-2 activity correlated significantly and negatively with the number of CD3+ lymphocytes and CD4+ lymphocytes. The change rate of ADA-2 activity during three months' treatment correlated significantly and negatively with the change rate of CD4/8. These results may suggest that there is a close correlation between the activity of ADA-2 and lymphocyte subpopulation in the sera of patients with pulmonary tuberculosis. ADA-1 activity did not correlate with lymphocyte subpopulation significantly, but it decreased significantly after three months' treatment. The activity of ADA-1 also may have certain relations with the disease process of pulmonary tuberculosis.

Adenosine Deaminase↗
PubMed1997

[Lung cancer with a sarcoid-like reaction in the primary tumor].

An 80-year-old woman was admitted to the hospital because of a nodular lesion in the right upper lobe of the lung. Transbronchial biopsy was performed and adenocarcinoma of the lung was confirmed by pathological examination. The tumor was resected by right upper lobectomy and was found to be a moderately differentiated tubular adenocarcinoma. Numerous non-caseating epithelioid cell granulomas were also found intermingled with the cancer cells. Metastasis was apparent in several regional lymph nodes but no granulomatous lesions were found in any lymph node, regardless of metastasis. These findings were compatible with a "sarcoid-like reaction" because there was no clinical evidence of generalized sarcoidosis or pulmonary mycobacterial infection. Although sarcoid-like reactions are occasionally associated with cancer, formation of an epithelioid cell granuloma inside the primary tumor is very rare. All the reported cases of a sarcoid-like reaction within the primary lung tumor so far were with adenocarcinoma. The sarcoid-like reaction may be a local immune response to the cancer cells.

Adenocarcinoma↗