Biomedical subjects

S Yang

Publications and source records attributed to S Yang.

At least 127 records · Page 7Linked to original sources

PubMed2001

Grtp1, a novel gene regulated by growth hormone.

An in vitro model of GH-responsive cells was subjected to microarray analysis to identify a novel gene regulated by GH. This 258 amino acid protein, we term GH Regulated TBC Protein-1 (GRTP1), contains the TBC signature motif of GTPase activator proteins of Rab-like small GTPases. Northern blot analysis revealed a 1.3 kb major mRNA species, most abundant in testes. TaqMan assay confirmed that in the mouse, Grtp1 is expressed at highest levels in testes, with lesser abundance in intestine, kidney, lung, and liver. In the testis, expression of Grtp1 significantly increases post-pubertally. Administration of GH to mice increased levels of GRTP1 mRNA in testes (140%), but decreased GRTP1 mRNA abundance in kidney (50%) and liver (25%). Grtp1 was localized to mouse proximal chromosome 8. Orthologs of this protein are present in human, mouse, rat, and drosophila suggesting that GRTP1 has an important biological role(s).

Amino Acid Sequence↗

PubMed2001

Stromal PRs mediate induction of 17beta-hydroxysteroid dehydrogenase type 2 expression in human endometrial epithelium: a paracrine mechanism for inactivation of E2.

Progesterone stimulates the expression of 17beta-hydroxysteroid dehydrogenase (HSD) type 2, which catalyzes the conversion of the potent estrogen, E2, to an inactive form, estrone, in epithelial cells of human endometrial tissue. Various effects of progesterone on uterine epithelium have recently been shown to be mediated by stromal PRs in mice. We describe herein a critical paracrine mechanism whereby progesterone induction of 17beta-HSD type 2 enzyme activity, transcript levels, and promoter activity in human endometrial epithelial cells are mediated primarily by PR in endometrial stromal cells. Medium conditioned with progestin-pretreated human endometrial stromal cells robustly increased 17beta-HSD type 2 enzyme activity (2-fold) and mRNA levels (13.2-fold) in Ishikawa malignant endometrial epithelial cells. In contrast, direct progestin treatment of Ishikawa epithelial cells gave rise to much smaller increases in enzyme activity (1.2-fold) and mRNA levels (4-fold). These results suggest that progesterone- dependent paracrine factors arising from stromal cells are primarily responsible for the induction of epithelial 17beta-HSD type 2 expression in the endometrium. We transfected serial deletion mutants of the -1,244 bp 5'-flanking region of the 17beta-HSD type 2 gene into Ishikawa cells. No progesterone response elements could be identified upstream of the 17beta-HSD type 2 promoter. Stromal PR-dependent induction of the 17beta-HSD type 2 promoter was mediated by a critical regulatory region mapped to the -200/-100 bp sequence. Direct treatment of Ishikawa cells with progestin gave rise to a maximal increase in the activity of -200 bp/Luciferase construct only by 1.2-fold, whereas medium conditioned by progestin-pretreated endometrial stromal cells increased promoter activity up to 2.4-fold in a time- and concentration-dependent manner. The stimulatory effect of medium conditioned by progestin-pretreated stromal cells was enhanced strikingly by increasing stromal cell PR levels with the addition of estrogen. This epithelial-stromal interaction was specific for endometrial epithelial cells, since 17beta-HSD type 2 could not be induced in malignant breast epithelial cells by media conditioned with progestin-treated breast or endometrial stromal cells. In conclusion, progesterone regulates the conversion of biologically active E2 to estrone by inducing the 17beta-HSD type 2 enzyme in human endometrial epithelium primarily via PR in stromal cells, which secrete factors that induce transcription mediated primarily by the -200/-100 bp 5'-regulatory region of the 17beta-HSD type 2 promoter.

17-Hydroxysteroid Dehydrogenases↗

PubMed2001

[Comparison of denaturing high performance liquid chromatography with direct sequencing in the detection of single nucleotide polymorphism].

OBJECTIVE: Investigate the sensitivity and accuracy of the denaturing high performance liquid chromatography(DHPLC) technique for the detection of single nucleotide polymorphism(SNP). METHODS: Forty-one samples were detected by both DHPLC and direct sequencing. RESULTS: The comparison demonstrated that DHPLC detected all heterozygous sequences found by direct sequencing. No false-positive signals were seen in the cases of homozygous sequences. Furthermore, no false-negative results were ever obtained with heterozygous mutations or polymorphisms, or both. CONCLUSION: DHPLC is a potent method for SNP identification especially SNP typing in large scale screening.

Chromatography, High Pressure Liquid↗

PubMed2001

[Diagnostic value of five serum markers for liver fibrosis].

OBJECTIVE: To research the diagnostic value of serum hyaluronic acid (HA), type III procollagen (PCIII), type IV collagen (CIV), laminin (LN), and transforming growth factor-beta(1) (TGF-beta(1)) for liver fibrosis in patients with chronic hepatitis. METHODS: Serum levels of HA, PCIII, CIV, LN and TGF-beta(1) in 116 patients with chronic hepatitis and cirrhosis were investigated and compared with hepatic histological findings of 87 patients. RESULTS: The correlation between serum HA and histologically assessed grade of inflammatory activity was weak (r=0.393, P<0.05). The correlation between serum HA, PCIII, LN, TGF-beta(1) and histologically assessed stage of liver fibrosis were all moderate (r=0.584, 0.454, 0.441 and 0.612, respectively, P<0.05), while that between serum CIV and histologically assessed stage of liver fibrosis was weak (r=0.319, P<0.05). As shown by the ROC curves in cases of chronic hepatitis, the ability to differentiate patients with cirrhosis from those without cirrhosis was greater for serum HA than that for serum PCIII, CIV, LN, and TGF-beta(1) (the areas under the curves=0.904 vs 0.784, 0.815, 0.805, 0.828, P<0.05). The ability of serum HA, LN and TGF-beta(1) to differentiate patients with extensive liver fibrosis from those with no or mild liver fibrosis exceeded that of serum PCIII and CIV (the areas under the curves=0.849, 0.819, 0.836 vs 0.702, 0.721, P<0.05). To discriminate the stage of liver fibrosis, serum HA and TGF-beta(1) were selected from the five markers by Bayes discriminate analysis. If S(1), S(2) and S(3) were not required to be discriminated, discrimination between the three stages showed significant difference (P<0.05). The predictive accurate percentage was 72.90%. CONCLUSIONS: The five markers all have the ability not only to judge liver cirrhosis, in which the ability of serum HA is the best, but also to differentiate chronic hepatitis with extensive liver fibrosis from that with no or mild liver fibrosis, in which the ability of serum HA, LN, TGF-beta(1) is stronger than the other two. It is useful for detection of serum HA and TGF-beta(1) at the same time to discriminate the histologically assessed stage of fibrosis. Serum HA and TGF-beta(1) can be helpful in discriminating patients of chronic hepatitis with "no liver fibrosis", "liver fibrosis but no cirrhosis" and "liver cirrhosis", but cannot discriminate them accurately as the histologically assessed stage of fibrosis. They cannot displace liver biopsy for the judgement of liver fibrosis.

Adult↗

PubMed2001

[A simple and rapid new method for SNP typing by single-tube bi-directional allele specific amplification].

OBJECTIVE: To establish a new method for single nucleotide polymorphism(SNP) typing based on allele specific PCR: single-tube bi-directional amplification (SB-ASA), and study the influence on specific extension by introducing a mismatch at the third 3'terminal base of allele specific primers. METHODS: Two allele specific primers, with a mismatch introduced at the third 3'terminal base, were both included in PCR system; they extended in opposite directions and amplified two allele specific fragments different in size. The genotype was determined by observing the length of amplified fragments after agarose electrophoresis. The proper ranges of annealing temperature (Ta) under which primers can specifically extend were achieved by observing the amplification status at different temperatures. RESULTS: SB-ASA was successfully used to type 36 samples for four different kinds of SNPs. Typing results were completely consistent with those by directional sequencing. Proper Ta ranges of two primers were expanded respectively from 64-69 degrees centigrade to 46-66 degrees centigrade and from 60-62 degrees centigrade to 56-61 degrees centigrade by introducing a mismatch at the third 3'terminal base. CONCLUSION: SB-ASA is a simple, rapid and efficient new method for SNP typing. During allele specific PCR reaction, specific primers with a mismatch at the third 3'terminal base have more power to identify two alleles.

Alleles↗

PubMed2001

Clinical study on treatment of chronic renal failure with shenshuailing.

The therapeutic effects of Shenshuailing Kou Fu Ye (SKFY [symbol: see text], the Oral Liquid for Renal Failure) and Shenshuailing Guan Chang Ye (SGCY [symbol: see text], the Enema for Renal Failure) were evaluated in treatment of chronic renal failure, with coateg aldehyde oxystarch as the controls. The changes in the clinical symptoms, serum creatinine, blood urea nitrogen and creatinine clearance rate were observed. The total effective rate in the former was 90.46%, and the latter 60.43%.

Aged↗

PubMed2001

[Seroepidemiologic study on hemorrhagic fever with renal syndrome virus in the migration areas of the Three-Gorges Reservoir Chongqing, Region, Yangtze River].

OBJECTIVE: To ascertain both the immune level and latent infection status among the migrants from the Three-Gorge Reservoir, Chongqing Region. METHODS: Epidemiological survey and seroepidemiologic study were performed on the spots. Sera HFRSV-IgG antibody of migrations was detected with the indirect immunofluorescent assay technique(IIFAT). RESULTS: Three in 5 migration areas were seral HFRSV-antibody-positive, i.e. Baitao Town of Fuling Section, Wansheng Village of Fengjie County and Dachang Town of Wushan County, which not only will be evacuated, but also be taken for relocation. However the antibody titer was not high, with positive rates of HFRSV-IgG Ab 0.9%, 3.3% and 3.5% respectively. The other two areas attributed to relocation, HFRSV-IgG-antibody were negative. CONCLUSIONS: This article confirmed that covert infection rate of HFRS in 5 migration areas was not high. The immune level remained low. Hence, it is very necessary to enhance the immunity of the immigrants.

China↗

PubMed2001

Stimulation by melittin of Na+-Ca2+ exchange current in ventricular myocytes of guinea pigs.

AIM: To study the mechanism of calcium overload induced by melittin in myocytes. METHODS: Whole cell patch-clamp technique was applied for recording the currents. RESULTS: Mel 0.05, 0.1 micromol/L increased the peak amplitude of I(Na) (nA) from -2.1+/-0.8 to -3.2+/-1.0 (n=7, P < 0.05) and -3.7+/-1.5 (n=7, P < 0.05) respectively at testing potential of -40 mV. Mel 0.05, 0.1, 0.2 micromol/L had no significant effect on I(Ca), but enhanced I(Na-Ca) (pA) from 53+/-21 to 427+/-256 (n=5, P < 0.05), 349+/-147 (n=5, P<0.01) and 320+/-97 (n=5, P < 0.05) respectively at a testing potential of +50 mV. CONCLUSION: The stimulating effect of Mel on I(Na-Ca) rather than the effect on I(Ca) contributes to the calcium overload of myocytes.

Animals↗

PubMed2001

Inhibitory effect of melittin on Na+,K+-ATPase from guinea pig myocardial mitochondria.

AIM: To investigate the effect of melittin (Mel) of Na+,K+-ATPase activity and it's kinetic mode of action on guinea pig myocardial mitochondria. METHODS: Effect of Mel on heart mitochondrial Na+,K+-ATPase activity was determined with colorimetry method. RESULTS: Mel inhibited Na+,K+-ATPase in a concentration and time dependent manner, IC50 was 2.60 micromol/L. Kinetic studies of interaction between Mel and K+, Na+, ATP revealed that inhibitory effect of Mel was competitive with K+, but not with Na+ and ATP. CONCLUSION: Mel polypeptide potently inhibits Na+,K+-ATPase, possibly by binding to the K+ site.

Animals↗

PubMed2001

Effects of melittin on isolated papillary muscles of guinea pig.

AIM: To investigate the effect of melittin (Mel) on papillary muscles of guinea pigs. METHODS: Contraction of papillary muscles were examined by conventional method and action potentials (AP) were recorded by standard glass microelectrode technique. RESULTS: Mel (0.5, 3 micromol/L) significantly increased the contractility of guinea pig papillary muscles while 5 micromol/L exerted dual action with a transient decrease followed by an increase of the contractility. Mel shortened the functional refractory period (FRP) at concentrations of 0.5, 3, and 5 micromol/L and increased the automaticity induced by adrenaline (Adr) at 3 and 5 micromol/L. Mel shifted the duration-intensity curve upward at 3 micromol/L. It shortened the action potential duration (APD) of fast action potential (FAP), decreased the action potential amplitude (APA) and resting potential (RP) at 0.5 and 3 micromol/L. As to slow action potential (SAP), Mel 0.8 micromol/L shortened APD20 and APD50, and decreased APA and RP. CONCLUSION: Mel increased the contractility and automaticity of papillary muscles, shortened the FRP, decreased the excitability, shortened the APD, and decreased APA and RP of AP.

Action Potentials↗

PubMed2001

[Diagnosis and treatment of spontaneous spinal epidural hematoma].

OBJECTIVE: To evaluate the cause of hemorrhage of spontaneous spinal epidural hematoma (SSEH), its clinical manifestations, MR images, treatment, and prognosis. METHODS: Based on literature review, we retrospectively analysed 6 patients with SSEH in terms of pathogenic mechanism, clinical features, neurological function, and the interval between the onset of SSEH and surgery and prognosis. RESULTS: SSEH was liable to occur in young people, and most of cases were acute. MR imaging showed semilunar space occupying mass in the posterior or posteriolateral part inside the spinal canal. The outcome was closely related to the interval between the onset and surgery, whereas it was not related to age, site and size of the hematoma. The better neurological state before surgery and the shorter interval between onset and operation, the better outcome in such patients. CONCLUSIONS: SSEH may be originated from venous bleeding. The process at onset and clinical manifestation depends on the blood supply of the spinal cord. The optimal diagnostic method is MR imaging. Decompression of spinal cord in time is the key procedure for improving the patients' outcome.

Adolescent↗

PubMed2001

[A novel gene mutation in a congenital protein S deficiency pedigree].

OBJECTIVE: To study the phenotype and genotype of a protein S (PS) deficiency pedigree. METHODS: Detection of total and free PS antigen was carried out by ELISA, PS activity by coagulation assay, amplification of exon I-XII fragments of PS gene by polymerase chain reaction (PCR), changes of denaturing cDNA by single-strand conformation polymorphism (SSCP) and gene mutation by DNA sequencing. RESULTS: In the 9 members of the pedigree, free PS was between 10.3%-45.5% (normal range 55%-128%) and PS activity between 13%-37% (normal range 70%-130%), but total PS was normal. A G to T change in exon X of the protein S gene was identified. This mutation resulted in a substitution of stop codon for Ser. CONCLUSION: It was demonstrated that the proband is heterozygosity and the existance of G163 T change in exon X of the protein S gene led to a substitution of stop codon for Ser. This mutation is a novel undescribed mutation.

Adult↗

PubMed2001

[Physiology and development of two Roegneria kamoji populations stressed by copper].

Roegneria kamoji grown copper tailings had weak stem, short height, and thick leave color, while its counterpart on normal soil was the opposite. Exposed to copper, R. kamoji had a decreased chlorophyll content. A certain concentration of copper could promote the seed germination of R. kamoji, and the extract of copper tailings did not decrease the seed germination rate, but deferred the germination. Root growth test indicated that when the concentration of copper was 0.125 mg.L-1, the rooting of R. kamoji was promoted. If the concentration was more than 0.25 mg.L-1, the rooting was inhibited significantly. R. kamoji colonized on normal soil wase more sensitive to copper than that on Cu-polluted soil.

Chlorophyll↗

PubMed2001

[Influence of Adam Schall's changing calendar on Yun - qi theory in the early Qing Dynasty].

The Yun - qi theory is closely related to the calendar system. In Chinese history, the change of the calendar system by Adam Schall von Bell in early Qing Dynasty was a disputable event. Studying its effect on Yun - qi theory, we find out the issue of changing the order of Zi and Shen lunar mansions, which annoyed many Chinese astronomers and scholars, had no significant influence on Yun - qi theory. As for the new calculation system of clepsydra and solar terms, these changes increased the accuracy of the Yun - qi calendar.

Astronomy↗

PubMed2001

[Human telomerase RNA (hTR) expression in lung cancer in the Gejiu and Xuanwei regions of Yunnan].

OBJECTIVE: To investigate the correlation between the expression of hTR in and the pathogenesis of lung cancer in Gejiu and Xuanwei regions of Yunnan province. METHODS: By use of in situ hybridization, the expression of hTR gene was observed in 81 cases of lung cancer tissues including 24 cases of Gejiu Tin miners (GTM), 36 cases of Xuanwei farmers (XF) and 21 cases of other regions. RESULTS: hTR was detected in 65.4% (53/81) of the lung cancer cases. The positive rate of hTR in GTM, XF and other regions was 66.7% (16/24), 58.3% (21/36) and 76.2% (16/21) respectively. Positive hTR expression was not found in normal bronchial and alveolar epithelia, but was found in highly proliferating type II alveolar epithelial cells adjacent to the carcinoma (12.3%, 10/81). No significant difference was observed with regard to the positive rate of hTR expression among three different regions. There was no statistically significant correlation between the expression of hTR, the patients' sex, age and the differentiation degree of the tumor, but the expression of hTR was correlated with histological type and lymph node metastasis (P < 0.05). CONCLUSION: The expression of hTR is a prevailing event in lung cancer and therefore can be used as an indicator of lung malignancy.

Adult↗

PubMed2001

Pathogen of root surface caries in the elderly.

OBJECTIVE: To study the pathogen of root surface caries in the elderly. METHODS: Plaque samples from the experimental group and the control group were collected. After culturing in selective and non-selective media, the different bacteria were isolated. The counts and the positive rates of total bacteria, porphyromonas group, pervotella group, streptococcus mutants group, actinomyces group and lactobacillus group were compared. RESULTS: The counts of total bacteria, streptococcus mutants, actinomyces and lactobacillus of the experimental group were higher than those of the control group. The positive rates of actinomyces and lactobacillus of the experimental group were significantly higher than those of the control group. CONCLUSION: Actinomyces and lactobacillus are the main related pathogens of root surface caries in the elderly.

Actinomyces↗

PubMed2001

Increased expression of Hsp70 and co-localization with nuclear protein in cells infected with the Hantaan virus.

OBJECTIVE: To investigate the effect of Hantaan virus infection on the expression of stress genes. METHODS: Techniques of virus infection, Western blot, immunohistochemistry, dual-immunofluorecsence staining, laser scanning confocal microscopy, RNA dot blot and in situ hybridization were used. RESULTS: Expression of heat shock protein 70 (Hsp70) was observed in cells infected with HTV as well as the translocation of Hsp70 from cytoplasm to nucleoli following virus infection. The variable distribution of Hsp70 was related to the various time after infection. Double-label indirect immunofluorescence of nuclear protein (NP) and Hsp70 in infected cells demonstrated co-localization of these proteins in the cytoplasm. CONCLUSION: Overexpression of Hsp70 can be induced directly by Hantaan virus, which may be associated with virus protein assembly. The Hantaan virus proteins co-localize with, and possibly form a physical complex with cellular Hsp70 in infected cells.

Animals↗

PubMed2001

Myocardial protection with pinacidil induced hyperpolarized arrest during cardiopulmonary bypass.

OBJECTIVE: To investigate the myocardial protective effects of pinacidil-induced hyperpolarized arrest and compare with those afforded by conventional depolarized hyperkalemic arrest. METHODS: Eighteen dogs were equally divided into three groups: normothermic hyperpolarized group (Group A), hypothermic hyperpolarized group (Group B), and hyperkalemic group (Group C). Pinacidil (50 mumol/L) containing 37 degrees C St. Thomas solution (K+ 5 mmol/L, 10 ml/kg), pinacidil (50 mumol/L, Sigma, USA) containing 4 degrees C St. Thomas solution (K+ 5 mmol/L, 10 ml/kg) and 4 degrees C standard St. Thomas solution (K+ 16 mmol/L, 10 ml/kg) were infused respectively through the aortic root after aortic-clamping. Heart arrest and its recovery, ultrastructure of the myocardium, the level of serum myocardial enzymes, and lipid peroxide and adenine nucleotide of the myocardium were measured. Hemodynamics during ischemia and after reperfusion were observed. RESULTS: The percentages of normal mitochondria and glycogen did not change much during ischemia (except at 60 min) and after reperfusion in B Group, but declined markedly in Group C 30 min and 60 min after ischemia and 20 min after reperfusion (P < 0.01). In Group A, they were lower than those of Group B before ischemia, but higher than those of Group C. The recoveries of CO, SV, CI, LVSW, RVSW and MAP in Group B were significantly better than those in other two groups 15 min and 30 min after reperfusion (P < 0.05 and 0.01, respectively). However, they were still better in Group A than those in Group C (P < 0.05 and 0.01, respectively). The onset of heart arrest was faster in Groups C and B than that in Group A. Highly elevated serum myocardial enzymes were observed 60 min after ischemia and 20 min after reperfusion in Group C, while they were only mild in the hyperpolarized groups, especially in Group B, and their recoveries were rapid. Adenine nucleotides of the myocardium were better preserved in Group B than in other two groups 30 min, 60 min after ischemia, and 20 min after reperfusion (P < 0.05 and 0.01, respectively). They were also much better in Group A than in Group C (P < 0.05 and 0.01, respectively). Lipid peroxide of the myocardium were significantly lower in Group B than in other groups 20 min after reperfusion (P < 0.01), and they were lower in Group A than in Group C (P < 0.05). CONCLUSIONS: Myocardial protection for global ischemia during cardiopulmonary bypass (CPB) could be achieved with hyperpolarized heart arrest induced by pinacidil, an ATP-sensitive potassium channel opener, especially in the hypothermic state. The protection is weaker in normothermia but is still superior to that with traditional depolarized hyperkalemic arrest.

Adenine Nucleotides↗