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Biomedical subjects

G Ye

Publications and source records attributed to G Ye.

At least 37 records · Page 2Linked to original sources
PubMed1999

[The modulation of collagen synthesis and expressions of type I and III collagen mRNAs in aorta smooth muscle cell by PDGF and heparin].

OBJECTIVE: The effect of platelet derived growth factor (PDGF) and heparin on the modulation of human aorta smooth muscle cell(hASMC) proliferation, collagen synthesis, expressions of type I and III collagen mRNAs as well as transforming growth factor-beta (TGF-beta) mRNA were investigated. METHODS: 3H-TdR and 3H-proline incorporation and Northern blot analysis were done. 3H-TdR and 3H-proline incorporation was statistically analyzed with t test among different experimental groups. RESULTS: In comparison to the control group, PDGF possessed the ability in promoting markedly the DNA synthesis (3H-TdR incorporation: PDGF group vs control, P < 0.01), synthesis and secretion of collagen protein (3H-proline incorporation of SMC and medium: PDGF group vs control, P < 0.01), expressions of type I and type III collagen mRNAs, and transforming growth factor mRNA in hASMC. Whereas heparin significantly decreased the DNA synthesis (heparin group vs control, P < 0.01), synthesis and secretion of collagen protein (heparin group vs control, P < 0.01) of hASMC in vitro. Heparin also inhibited the promoting effect of PDGF on DNA synthesis, the synthesis and secretion of collagen protein, and reduced the up-regulation of expressions of type I and type III collagen mRNAs as well as TGF-beta mRNA that stimulated by PDGF. CONCLUSIONS: PDGF could promote the collagen synthesis through upregulating type I and type III collagen mRNA expressions while heparin just inhibiting SMC DNA and collagen synthesis effected in the way of anti-atherosclerosis.

Anticoagulants↗
PubMed1998

[Kinetic effect of testosterone or estradiol on iodine absorption in castrating rat intestine].

OBJECTIVE: To observe the effect of testosterone or estradiol on iodine absorption in rat intestine. METHOD: 50 male adult Wistar rats were divided into 5 groups randomly. 50 females were divided into another 5 groups. Among them, 4 groups were bilaterally testectomized or ovariectomized, 1 group was sham-operated. 7 days after operation, the castrated rats received testosterone (male rats) or estradiol (female rats) at different dosages by intramuscular injection for three days. Then the kinetics of iodine absorption in jejunum and ileum were observed by perfusion in situ. When finished, serum were obtained for detecting TSH, T4 and testosterone or estradiol. RESULTS: In castrated male rats, the value of K12 reduced, K21 increased, K02 reduced, and SP1/2 (the half time of the slow phase) prolonged, implying that the ability of iodine absorption reduced. It reflected that testosterone could promote iodine absorption in intestine in physiological condition. In castrated female rats, the situation was different from that in male rats, the value of K12 increased, K21 reduced, K02 increased, and SP1/2 shortened in jejunum, implying that the ability of iodine absorption increased. It reflected that estradiol could inhibit iodine absorption in intestine in physiological condition. The levels of serum TSH and T4 were not changed significantly in this experiment. CONCLUSION: In physiological condition, testosterone can promote iodine absorption, while estradiol has the inhibiting effect. The results indicate that gonadol hormone maybe one factor which can influence iodine absorption in intestine. It may explain the phenomenon that the incidence of goiter is different between males and females partly.

Animals↗
PubMed1998

The effect of class II major histocompatibility complex expression on adherence of Helicobacter pylori and induction of apoptosis in gastric epithelial cells: a mechanism for T helper cell type 1-mediated damage.

Helicobacter pylori infection is associated with gastric epithelial damage, including apoptosis, ulceration, and cancer. Although bacterial factors and the host response are believed to contribute to gastric disease, no receptor has been identified that explains how the bacteria attach and signal the host cell to undergo apoptosis. Using H. pylori as "bait" to capture receptor proteins in solubilized membranes of gastric epithelial cells, class II major histocompatibility complex (MHC) molecules were identified as a possible receptor. Signaling through class II MHC molecules leading to the induction of apoptosis was confirmed using cross-linking IgM antibodies to surface class II MHC molecules. Moreover, binding of H. pylori and the induction of apoptosis were inhibited by antibodies recognizing class II MHC. Since type 1 T helper cells are present during infection and produce interferon (IFN)-gamma, which increases class II MHC expression, gastric epithelial cell lines were exposed to H. pylori in the presence or absence of IFN-gamma. IFN-gamma increased the attachment of the bacteria as well as the induction of apoptosis in gastric epithelial cells. In contrast to MHC II-negative cell lines, H. pylori induced apoptosis in cells expressing class II MHC molecules constitutively or after gene transfection. These data describe a novel receptor for H. pylori and provide a mechanism by which bacteria and the host response interact in the pathogenesis of gastric epithelial cell damage.

Animals↗
PubMed1997

Expression of B7-1 and B7-2 costimulatory molecules by human gastric epithelial cells: potential role in CD4+ T cell activation during Helicobacter pylori infection.

Human gastric mucosal epithelial cells display class II MHC, the expression of which is increased during Helicobacter pylori infection. These observations suggest that the gastric epithelium may participate as antigen-presenting cells (APC) during local immune responses. The increase in class II MHC expression occurs in parallel with an elevation in gastric CD4+ T cell numbers within and adjacent to the epithelium. Since the expression of either B7-1 (CD80) or B7-2 (CD86) on APC is required for the activation of T cells, it was important to establish human gastric epithelial cells expressed those surface ligands. The expression of B7-1 and B7-2 was detected on human gastric epithelial cell lines and freshly isolated epithelial cells from gastric biopsies with specific antibodies. B7-2 expression was higher than B7-1 at both protein and transcript levels and was increased after crosslinking class II MHC molecules on IFNgamma-treated epithelial cells and in cells pretreated with the combination of IFNgamma and H. pylori. Similarly, B7-2 expression was higher on gastric epithelial cells from H. pylori-infected tissues compared with those from uninfected specimens. To determine the function of these molecules on gastric epithelial cells, antibodies to B7-1 and B7-2 were shown to reduce the ability of the cells to stimulate alloreactive CD4+ T cells. These observations are the first to demonstrate that B7-1 and B7-2 are expressed on mucosal epithelial cells in situ. Thus, the expression of B7-1 and B7-2 by epithelial cells may allow them to act as APC in regulating local responses such as those that occur during infection with H. pylori.

Antigens, CD↗
PubMed1997

Taurine inhibits rat substantia nigra pars reticulata neurons by activation of GABA- and glycine-linked chloride conductance.

Whole-cell recordings from rat midbrain slices showed that bath application of taurine (30 microM-10 mM) reversibly hyperpolarized and inhibited the firing of substantia nigra pars reticulata neurons. These effects were mediated by an increase in membrane chloride conductance. Taurine cross-desensitized with GABA and glycine. Strychnine competitively antagonized the actions of glycine and taurine but not that of GABA. On the other hand, the responses to taurine and glycine were not sensitive to bicuculline. These findings suggest that taurine inhibits SNR neurons by opening GABA and glycine-linked chloride channels.

Animals↗
PubMed1997

Antigen presentation of mucosal pathogens: the players and the rules.

A vast number of infectious pathogens gain entry into the host through mucosal surfaces, which have a much greater total surface area than the skin. Since the mucosa is continuously exposed to those pathogens, the development of an effective local immune response is of utmost importance. An obligatory step in the development of most immune responses is the presentation of antigens by specialized accessory cells, termed antigen-presenting cells (APC) to T lymphocytes. The recognition of antigens by T cells is largely determined by how the antigens are handled by the APC. Complex antigen-processing events generate a selected set of peptides which ultimately become associated with MHC molecules. The type of MHC molecules that bind the peptides in turn determine what T lymphocyte subset recognizes the peptides. Thus, an understanding of the molecular and cellular processes preceding the T cell recognition event is a prerequisite for understanding how mucosal immune responses develop, as well as for investigating alternative approaches to vaccine development and therapeutic strategies to control autoimmune diseases. This review discusses the cell biology of antigen processing and how various APC populations may participate in mucosal responses.

Animals↗
PubMed1997

[Operative treatment of vesical diverticula].

We reviewed the results of operative management of 31 patients with vesical deverticula, and introduce a simple technique for treating large bladder diverticula. In the 31 patients with vesical diverticula analysed, 23 were followed up for at least six months. Of the 31 patients, 25 were male and 6 female. The average age was 54.2 years. Diverticula was secondary to bladderoutlet obstruction. Seven cases had intradiverticular tumors, and 9 stones in the sac. The diagnosis of vesical diverticula was usually made by cystogram or ultrasonography. The operative indications for vesical diverticula included stone formation, intradiverticular tumor, ureteral obstruction, incomplete empting diverticulum and urine retention due to large diverticula. The combined extravesical and intravesical method was often used. 26 patients underwent both operations for outlet obstruction and vesical diverticula at the same time. Of the 23 followed-up cases, 21 had no symptoms of the urinary tract. Five of the 7 patients with intradiverticular tumor died within 2.5 years; one of the rest survived for 2 years, and the others for 6 years. Two patients with large vesical diverticula received intravesical separation of diverticula. No complications encountered in this simple, time-saving and safe procedure. Cystograms revealed normal condition. The choice of operative techniques to treat vesical diverticula varies with each individual patient. The technique of intravesical separation of vesical diverticula is suitable for large, adhesive and posterior diverticula.

Adult↗
PubMed1997

Health promotion of adolescents.

China has been making progress in adolescence health care, carrying out directed investigations and academic exchanges, as well as training. Since 1949, both growth and development of Chinese children and adolescents have accelerated significantly. Menarche and the secondary sex characteristics of girls now appear earlier than before. The average age of menarche is 12.5 years (1991) and boys average first emission is 14.33 years (1991). In China, the commonly encountered adolescent health problems are menstruation hygiene, menstruation dysfunction, emission, masturbation, teenage pregnancy, acne, obesity, smoking, alcohol drinking, drug abuse, and suicide. Causes of death of adolescents in China has significantly changed, all deaths caused by infectious diseases have dropped significantly. Of all death causes today, accidental injury is the leading one. Sexually transmitted diseases and tuberculosis have shown a rebound recently. The rate of smoking among middle school students in Beijing increased from the 1980s to 1990s, with male students' smoking at significantly higher rates than female students. Adolescents is a transitional period from dependent childhood to independent adulthood. Good physical and mental health of children and adolescents makes for good health in adulthood, therefore adolescence is a very important period in one's life. We need to go a step further and develop more detailed data on adolescent health and provide more health care for adolescents.

Adolescent↗
PubMed1997

Action of autonomic drugs on the in vivo bladder base and proximal urethra in dog.

OBJECTIVE: To investigate the effects of autonomic drugs on the in vivo bladder base and proximal urethra in order to provide some reference materials for clinical usage of these drugs in the treatment of bladder outlet dysfunction. METHODS: In 35 dogs, the bladder base was separated from the bladder body and closed to constitute a small chamber. The changes of the pressure in the bladder base chamber and proximal urethra were recorded synchronously before and after administration of autonomic drugs. All data were analyzed with Student's t test. RESULTS: The bladder base had little response to acetylcholine (Ach) which however promoted a contraction of the proximal urethra. The effect of Ach on the proximal urethra was antagonized by phentolamine, but not by atropine. Isoprenaline resulted in relaxation of the bladder base, though it had little effect on the urethra. Norepinephrine (NE) produced contraction of the bladder base and urethra, while phentolamine caused a reduction in the bladder base and urethral pressure, and blocked the response of the bladder outlet region to NE. Angiotensin amide (AII) caused contraction of the bladder base and urethra, which was not obliterated by phentolamine. CONCLUSIONS: The cholinergic drug has no influence on the in vivo canine bladder base, but causes a contraction of the proximal urethra through indirect activation of alpha-receptors. The alpha-adrenergic agents have great effects on the bladder base and urethra by acting on alpha-receptors within the musculature in the outlet region. The beta-adrenoceptor agonist results in relaxation of the bladder base, but it has no effect on the urethra.

Acetylcholine↗
PubMed1997

[Sex education in 6th and 7th grade girls].

OBJECTIVES: To help the students to know the basic knowledge on sexual health of adolescent, to have a positive attitude toward the phenomenon occurred during the adolescence; and to promote the health behaviors of girls. METHODS: Three hundred and sixty-three 6th and 7th grade girls from Fuxin city were involved. These girls were divided into experimental group and control by class. Pretest, post-test one month after education, and follow-up test four months after education were conducted respectively. RESULTS: After education, the score of basic knowledge on sexual health of the girls in the experimental group increased from 4.86 to 17.20. The score of positive attitude toward menstruation increased from 31.8 to 42.3. The percentage of the girls who had healthful and optimistic emotion during the menstruation increased from 43.5% to 82.9%. The percentage of the girls who visited hospital if they had reproductive diseases increased from 54.3% to 87.6%. The percentage of the girls who often wash the external genitals during menstruation increased from 50.9% to 79.0%. The ability of avoiding sexual harassment and abuse was enhanced. The follow-up test showed that the effects of sex education lasted. During the whole experimental process, no student who had sexual intercourse was discovered. CONCLUSION: Sex education in 6th and 7th grade girls is essential, feasible and effective in China.

Child↗
PubMed1997

[AFP, uE3, beta-hCG levels applied for prenatal diagnosis of Down's syndrome].

OBJECTIVE: To investigate the relationship between fetal trisomy 21 and alpha fetoprotein (AFP), unconjugated oestriol (uE3) and beta human chorionic gonadotropin (beta-hCG) levels in maternal serum, amniotic fluid and fetal serum. METHOD: AFP, uE3 and beta-hCG levels in maternal serum, amniotic fluid and fetal serum from 17 pregnancies with fetal trisomy 21 and 131 unaffected control pregnancies were measured between 16 to 28 weeks gestation using radioimmunoassay. RESULTS: In these pregnancies with fetal trisomy 21, the AFP and uE3 levels in maternal serum, amniotic fluid and fetal serum were lower than those in controls; but beta-hCG levels were higher (P < 0.05). CONCLUSION: To measure maternal serum AFP, uE3 and beta-hCG levels will be useful in prenatal detection of trisomy 21.

Adult↗
PubMed1997

[Influence of prenatal exposure to low levels of lead on the neuro-behavioral development of neonates].

OBJECTIVES: To study the effects on the neuro-behavioral development of neonates exposed to low levels of lead in utero. METHODS: 131 neonates were selected and their umbilical blood lead level was determined by Atomic Absorption Spectrometer. The neurobehavioral-cognitive performance of neonates was evaluated by Neonatal Behavioral Neurological Assessment (NBNA). RESULTS: NBNA scores in neonates with blood lead levels greater than or equal to 0.29 mumol/L were markedly lower than those with less than 0.14 mumol/L, and the difference was highly significant. CONCLUSION: Blood lead levels of less than 0.48 mumol/L could still have harmful effects on the development of children.

Child Development↗
PubMed1997

[Effects of nicotine on expression of c-fos-like protein in hippocampal formation in mice].

Expression of c-fos-like protein in hippocampal formation of mice, who were trained in a step-down test, was studied with immunohistochemical techniques to study the effects of nicotine on their learning and memory. Results showed that difference of their learning achievements (with number of errors in the test as an indicator) in a five-minute step-down test between trial and control groups did not reach statistical significance, but expression of c-fos-like protein in hippocampal formation in trial mice two hours after administration of nicotine was significantly different from that in controls. Number of positive c-fos cells in hippocampal CA3 and dentate gyrus of the mice treated with 2 mg/kg of nicotine was significantly greater than that in those treated with 1 mg/kg (P < 0.01), and there was no difference in it between those treated with 1 mg/kg of nicotine and controls treated with normal saline. It suggests that 2 mg/kg of nicotine may damage their learning and memory in mice.

Animals↗
PubMed1997

[A prevalence study on risk factors of cardiovascular disease during childhood].

A small size of sample for risk factors of cardiovascular disease, such as blood pressure, plasma lipids profile, obesity, dietary status, and family history of cardiovascular disease, etc. were studied in children aged eight to eleven years. Results showed that prevalence of hypertension, systolic blood pressure > 16.0 kPa (120 mmHg) or/and diastolic blood pressure > 10.7 kPa (80 mmHg), in them was 7.2 percent, blood lipid level in 21.9 percent of the children exceeded the recommended criteria of dietary intervention, and prevalence of simple obesity was 11.7 percent. The most prominent problem in dietary status was high cholesterol intake, with a daily intake of 483.4 mg in average, and 72 percent of the children exceeded 300 mg daily, as compared with previous data, and they exposure to higher level of risk factors for cardiovascular disease. It suggests that it is necessary to strengthen surveillance for risk factors of cardiovascular disease and intervention.

Cardiovascular Diseases↗