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Biomedical subjects

S Ye

Publications and source records attributed to S Ye.

At least 145 records · Page 8Linked to original sources
PubMed1995

European Atherosclerosis Research Study: genotype at the fibrinogen locus (G-455-A beta-gene) is associated with differences in plasma fibrinogen levels in young men and women from different regions in Europe. Evidence for gender-genotype-environment interaction.

The European Atherosclerosis Research Study (EARS) compares genetic and environmental factors in the offspring of fathers with myocardial infarction before the age of 55 years (designated cases) and control subjects from five different regions of Europe. Genotype was determined for a G-A polymorphism 455 bp upstream from the start of transcription of the beta-fibrinogen gene. In 585 cases and 1106 control subjects, the relative frequency of the A allele was similar (0.223 and 0.217, respectively), with small and nonsignificant differences in frequency observed among the five regions. Because of evidence for an interaction between a number of factors and genotype in the determination of plasma fibrinogen levels (in particular among female cases who reported use of oral contraceptives), the data were analyzed without adjusting for covariates except for age and region, and analyses were carried out excluding women taking oral contraceptives (n = 297). In agreement with previous reports, in all regions the A allele was associated with elevated plasma fibrinogen levels, with the strongest and most consistent effects being seen in men. In nonsmokers, after adjusting for the effects of age and region, male cases and control subjects with genotype A/A had mean fibrinogen levels 0.49 and 0.33 g/L higher, respectively, than those with genotype G/G, whereas those with genotype G/A had intermediate levels (P < .01). In female nonsmokers there was a similar but smaller and nonsignificant effect (A/A levels higher than G/G by 0.12 and 0.07 g/L, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

The codon usage of the nisZ operon in Lactococcus lactis N8 suggests a non-lactococcal origin of the conjugative nisin-sucrose transposon.

An 11.6 kb area downstream from the structural gene of nisin Z in the conjugative nisin-sucrose transposon of Lactococcus lactis subsp. lactis N8 was cloned and sequenced. Analysis of the sequence revealed eight open reading frames, nisZBTClPRK, followed by a putative rho-independent terminator (delta G degrees = -4.7 kcal/mol). The C-terminal hydrophilic domain of the NisK protein is homologous to the C-termini of several histidine kinases of bacterial two-component regulator systems, such as SpaK from Bacillus subtilis and KdpD and RcsC of Escherichia coli. The nisin Z biosynthetic genes were highly similar with the genes of the nisin A operons having, however, a 0-3% difference in the amino acid sequences of the individual proteins. The codon usage of eleven genes within the same conjugative transposon was calculated and found to be strikingly different from that of other lactococcal genes. This, together with the low GC-content (32%) compared to the 38% (G+C) of the lactococcal chromosome in general strongly suggests a non-lactococcal origin of this transposon.

Amino Acid Sequence↗
PubMed1995

[Effect of tetramethylpyrazine on lymphocytes proliferation response of murine splenocytes].

The effect of tetramethylpyrazine (TMP) on lymphocytes proliferation response (LPR) detected by 3H-TdR incorporation into murine monocytes. The results showed that TTMP at the concentration of 100-1000 micrograms/ml inhibited LPR in normal mice and B14-melanoma bearing mice in vitro the effect was dose-dependent. It was also found TTMP could stimulate LPR to Con A at the concentration of 1 micron/ml in normal mice, and at the concentration of 100-1000 micrograms/ml in B16-melanoma bearing mice. But TTMP inhibited LPR to Con A at the concentration of 100-1000 micrograms/ml in normal mice. The restoration of LPR to PHA and increasing 3H-TdR incorporation into splenocytes were found in vivo in B16-melanoma bearing mice after treatment with TTMP. The data indicates that TTMP has an immune modulation.

Adjuvants, Immunologic↗
PubMed1995

[Flow cytometry used to distinguish between complete and partial hydatidiform moles].

The nuclear ploidy of 14 placentas was determined by flow cytometry. All histologically classified complete moles (4 cases), hydropic villi (4 cases) and control placentas (3 cases) were diploid; whereas two of three histologically classified partial moles were triploid. The remaining case classified as partial mole was diploid, most likely a complete mole. It was concluded that DNA flow cytometric analysis offers an informative supplement to the histological interpretation of hydropic placentas.

DNA, Neoplasm↗
PubMed1995

[Endoscopic mucosectomy for resection of early gastric cancer and precancerous lesions].

The authors collected 14 cases of early gastric cancer located in the mucosa and precancerous lesions which were resected with endoscopic mucosectomy. These lesions were as follows: 6 cases were early cancer (IIc type: 4 cases; IIa type: 2 cases); 3 cases were severe dysplasia; 5 cases were adenoma, Yamada I type. The size of all the lesions was less than 20mm. Four cases of early gastric cancer were resected completely. Two cases were resected incompletely, but radical gastrectomy was performed one month after endoscopic mucosectomy. All the three cases of severe dysplasia had complete resection. But two of them received resection twice. Five cases of adenoma were also resected completely. The criteria of complete endoscopic resection were those reported in the Japanese literature. All cases have been followed up for 4-41 months; endoscopic and histological studies showed that there were no residual and recurrent cancer cells. The complete resection rate was 85.7% (12/14). The results suggest that endoscopic mucosectomy can be applied to the patients with early gastric cancer located in the mucosa and precancerous lesions less than 20mm in size, which can be resected completely. This method is safe, entails less complications and is especially suitable for the old and weak patients.

Adenoma↗
PubMed1995

The 4G/5G genetic polymorphism in the promoter of the plasminogen activator inhibitor-1 (PAI-1) gene is associated with differences in plasma PAI-1 activity but not with risk of myocardial infarction in the ECTIM study. Etude CasTemoins de I'nfarctus du Mycocarde.

We have investigated the interrelationships of plasma PAI-1 activity, the PAI-1 4G/5G polymorphism and risk of myocardial infarction (MI) in the ECTIM study, a case-control study of MI based in Belfast, Lille, Strasbourg and Toulouse. Mean PAI-1 levels in cases were similar across all centres but in controls, levels in the French centres were significantly higher. Only in Belfast were PAIl1 levels higher in cases (11.7 AU/ml) than controls (10.5 AU/ml). The PAI-1 4G allele frequency was similar in cases and controls (0.55 and 0.54). In all groups, 4G homozygotes had the highest mean plasma PAI-1 level (4G4G vs 5G5G; cases overall: 14.2 vs 12.1AU/ml; controls overall: 15.0 vs 12.6AU/ml), with the heterozygotes generally intermediate. The data from Belfast are consistent with the literature implicating PAI-1 level as an MI risk factor. In ECTIM, the PAI-1 4G/5G polymorphism is not a genetic risk factor for MI but is associated with PAI-1 activity. Thus homozygosity for the 4G allele may predispose to elevated PAI-1 and impaired fibrinolysis, perhaps requiring interaction with other genetic or environmental factors to influence MI risk.

Adult↗
PubMed1995

[Gastric cancer with P53 overexpression and nm23 low-expression has high potential for lymph node metastasis].

By using SP immunohistochemical methods, the correlation of the expression of P53 and nm23 with the biologic behavior and lymph node metastasis in gastric carcinomas was studied. Abnormalities of P53 expression were found in 49% of the 88 primary gastric carcinomas. A significant correlation was found between P53 overexpression and the depth of invasion and the proliferative activities (Pearson Contingency Coefficient P = 0.32 and 0.35, P < 0.05, respectively). The metastatic rate of tumours stained positively for P53 (93%) were higher than in those with negative P53 staining (60%, P < 0.05). Meanwhile, a significant correlation of low expression of nm23 with the depth of cancer invasion was found (Pearson Contingency Coefficient P = 0.28, P < 0.05). nm23 low-expressive tumours were associated with a higher incidence of metastasis to lymph nodes (93%) than were nm23-normal expressive (49%, P < 0.05). The contributions of P53 overexpression and nm23 low-expression to the lymph nodal metastasis were the independent joint action. It is suggested that P53 overexpression and nm23 low-expression might play significant role in lymph node metastasis and invasion and proliferation in the primary gastric carcinomas.

Adenocarcinoma↗
PubMed1995

[The study of growth factors in human colostrum].

OBJECTIVE: To characterize and identify the growth factors in human colostrum and to evaluate the importance of breast-feeding. METHODS: The activity of growth factors in human colostrum was determined by technique of 3H-TdR incorporation into cultured NIH-3T3 cells. The acid growth factor (CAGF) and basic growth factor (CBGF) were purified from human colostrum by a sequence of chromatography. The study of stability and SDS-PAGE was applied to identify the CAGF and CBGF. RESULTS: 0.5% (v/v) of human colostrum and 3.0% (v/v) of bovine serum had the same activity in stimulating DNA synthesis. The specific activity of human colostrum in stimulating DNA synthesis was 20 times greater than that of bovine serum. The activity of growth factors in human colostrum was higher than that in human milk or bovine colostrum, and only human colostrum contained two different kinds of growth factors--CAGF and CBGF. CONCLUSIONS: Human colostrum contains two kinds of growth factors. CAGF is epidermal growth factor like (EGF-like) growth factor and the CBGF is platelet differentiation growth factor like (PDGF-like) growth factor. The effects of human colostrum on promoting baby growth and development is stronger than that of human milk and bovine colostrum.

3T3 Cells↗
PubMed1994

Polymorphism in the promoter region of the apolipoprotein AI gene associated with differences in apolipoprotein AI levels: the European Atherosclerosis Research Study.

The effect associated with the substitution of adenine (A) for guanidine (G) in the promoter region of the apolipoprotein AI gene (-75 bp) with plasma apo AI and high-density lipoprotein (HDL) levels was investigated in the European Atherosclerosis Research Study (EARS). This is a study of healthy offspring (cases) of fathers who had suffered premature myocardial infarction (MI) before age 55 years (n = 565) and age- and sex-matched controls (n = 1,078) from 12 European countries, divided into 5 regions based on geography and language. The frequency of the polymorphism was not significantly different among the regions and the relative frequency of the rare A allele was similar in cases and controls (0.159 vs. 0.142) combining data from all regions. Individuals with one or more A allele had significantly higher plasma apo AI levels (P < 0.05) than individuals homozygous for the G allele. This effect was consistent in all regions. The data were analyzed separately in males and females. In females, those with one or more A allele had significantly higher apo AI levels (P = 0.05) than individuals homozygous for the G allele, and this raising effect of the A allele was greater in cases than controls for both apo AI (5.23% vs. 1.56%) and HDL (4.48% vs. 1.89%). In males, the A allele was associated with higher levels of apo AI and HDL, but the effect was much smaller and the differences did not reach statistical significance. In the females, where the effect of the A allele was strongest, the effect on apo AI associated with genotype was evident in non-smokers, and individuals with one or two A alleles had 3.6% higher apo AI and 3.14% higher HDL levels than individuals homozygous for the G allele. However, in the female smokers the raising effect of the A allele was greatly reduced (0.56%). Thus genetic variation in the promoter region of the apo AI gene is associated with differences in apo AI and HDL levels in healthy individuals throughout Europe, but the effect is modulated by gender, environmental factors such as smoking, and a family history of MI.

Adenine↗
PubMed1994

[Effect of prednisolon, vincristine and mitoxantrone on glucocorticoid receptor in HL-60 cell line].

The effects of prednisolon, vincristine and Mitoxantrone on glucocorticoid receptor (GCR) content and affinity were examined in HL-60 cell line with a whole-cell assay in vitro. The fall in GCR number was observed following a short time exposure to prednisolon, vincristine or Mitoxantrone alone. The significant decrease occurred in a dose-dependent (10(-8)-10(-6) mol/L) and time-dependent manner. The treatment of HL-60 cells with 10(-6) mol/L led to a decrease in the affinity of whole cell GCR for [3H]Dex, but vincristine had no that effect. Synergia in GCR content was found during the treatment of HL-60 cells with prednisolon plus Mitoxantrone or prednisolon plus vincristine. The significance of these effects is discussed.

Dose-Response Relationship, Drug↗
PubMed1993

The glucocorticoid receptor precludes the binding of a transcriptional repressor protein to the long terminal repeat of the mouse mammary tumor virus.

The long terminal repeat (LTR) of the mouse mammary tumor virus was used as a template to examine the dual binding parameters of the glucocorticoid-receptor (GR) and a repressor protein termed Inhibitory Factor 1 (IF1). The receptor binds specifically to the glucocorticoid response element and precludes the binding of IF1 to its juxtaposed binding site within the LTR. When the two DNA targets are separated by the insertion of an additional 52 base pairs, coincident binding of both proteins is observed. Gel retention assays reveal three distinct nucleoprotein complexes. The first complex consists of the receptor and the LTR, the second is comprised of IF1 and DNA and the third is a multiprotein-DNA complex consisting of the GR, IF1 and DNA, migrating at a higher molecular weight position. The inhibition of IF1 binding by the presence of prebound GR leads to the repression of transcription of juxtaposed genes. The GR may act to block access of a sequence, used by the cell to titrate repressor proteins and facilitate the onset of gene expression.

Animals↗
PubMed1993

Positive regulation of tRNA gene expression by the mouse mammary tumor virus-long terminal repeat in vitro.

The mouse mammary tumor virus long terminal repeat (MMTV-LTR) participates in the control of gene expression by providing a series of important DNA binding sites at which trans-acting factors interact. Among these factors are the steroid receptor, nuclear factor I (NFI) and the TATA box factor (TFIID). The binding of these proteins facilitates the assembly of a transcriptionally competent complex, that includes RNA polymerase II, and activates the expression of juxtaposed genes in cis. A particular DNA sequence, distinct from previously identified regulatory elements, was found in the present study to activate gene expression in trans. The sequence is located between nucleotides +3 and +43 near the 3' terminus of the LTR. This sequence binds a protein that may actively repress the expression of genes that are not located immediately in cis. This protein was purified by ion exchange chromatography and has an approximate molecular weight of 31,000 daltons, as judged by SDS-PAGE. Gel retardation experiments reveal that progressively larger protein--DNA complexes are formed when the amount of this factor is increased relative to the DNA binding site. Furthermore, this protein was found to preferentially aggregate DNA molecules containing the LTR sequence between bases +3 and +43. These results reveal the existence of a unique modulatory role for the LTR in regulating gene expression in trans.

Animals↗
PubMed1993

A study of the structure, function and distribution of beta 5 integrins using novel anti-beta 5 monoclonal antibodies.

Here, we have utilized six new anti-human beta 5 monoclonal antibodies to perform a detailed investigation of the structure, function and distribution of beta 5 integrins. Monoclonal anti-beta 5 specificity was confirmed by reactivity with beta 5-transfected CHO cells, by direct binding to the beta 5 subunit (immunoblotting), and by immunodepletion experiments using polyclonal anti-beta 5 serum. The beta 5 subunit was predominantly associated with the alpha v subunit, although on some cell lines, the level of beta 5 exceeded that of alpha v for unknown reasons. Cell adhesion studies showed that the adhesive function of beta 5 could be stimulated, inhibited or unaltered by different anti-beta 5 monoclonal antibodies. The beta 5 subunit was involved in adhesion to both vitronectin and fibronectin and, at least for K562 cells, fibronectin appeared to be the preferred ligand. Flow-cytometry studies showed that the beta 5 subunit was expressed at moderate to high levels on all adherent cell lines examined, was absent from all lymphoid cell lines, and was only weakly expressed on myeloid cell lines. Staining of thymic sections showed the distribution of beta 5 on blood vessels, Hassal's corpuscles, cortical and medullary stromal cells, and basement membranes. Skin sections showed beta 5 on the basal layer of the epidermis and on some dermal blood vessel walls, and kidney sections showed staining of glomerular regions, juxta glomerular apparatus, proximal convoluted tubules and collecting tubules, and at least one anti-beta 5 antibody also stained epithelial cells of proximal tubules.

Animals↗
PubMed1993

Nude mouse interim host model for human parathyroid grafts. Part IV. Human PTG xenograft rejection in a mouse B lymphocyte system.

An interim host model for human parathyroid gland (PTG) grafts has been established. In this experiment, the proliferation of mouse blood vessels and infiltration of mouse B lymphocytes into human PTG grafts were successively observed. The results showed that within 10 d of interim hosting, when PTG grafts were still nourished by permeable factors, scattered mouse B lymphocyte infiltration was already apparent. As time went by, B lymphocyte infiltration and IgG secretion became more obvious. At 60-90 d interim hosting, an intact human-mouse tissue "chimera" was formed. Thereafter, human PTG grafts were gradually fragmented and absorbed. The theoretical significance and clinical value of this rejection phenomenon are discussed.

Animals↗
PubMed1993

Prevalence and epidemiologic correlates of sexually transmitted Chlamydia trachomatis infection in a selected population.

The incidence of Chlamydia trachomatis genitourinary infection was found by enzyme immunoassay antigen detection to be 10.0% in patients attending a sexually transmitted disease (STD) clinic, 3.0% in clients visiting an obstetrics-gynecology clinic, 20.8% in female prostitutes, and 1.3% in sexually active men. Predisposing factors for chlamydial infection were young age, multiple sexual partners, history of STDs, and coinfection with other STDs. Abnormal vaginal discharge and cervices in women, but not urethral manifestations in men, were significantly associated with chlamydial infection. Urethral gram stain had a certain value in identifying men infected with C. trachomatis.

Adult↗
PubMed1993

[Prevalence of antibody to hepatitis C virus in 177 drug addicts].

Antibody to hepatitis C virus (anti-HCV) was measured by enzyme-linked immunosorbent assay (ELISA) in 167 intravenous drug addicts, 10 oral drug addicts, 49 patients without liver disease and 58 blood donors. It was found that the prevalent rate of anti-HCV in these groups were 92.2%, 10%, 2.0% and 1.7%, respectively. It is also noted that the prevalence of anti-HCV for intravenous drug addicts was significantly higher than that for oral drug addicts, patients without liver disease, and blood donors (P < 0.001). There was no significant difference among the later three groups. It is indicated that intravenous drug addicts are high-risk group of HCV infection. Injecting drug with injectors of HCV carrier, injectors and/or solvent not being sterilized may contribute to prevalence of HCV in these groups. It is similar that the distributions of HCV infection in intravenous drug addicts with different trait.

Adolescent↗