Search PubMed⌕ Search

Biomedical subjects

Q Shao

Publications and source records attributed to Q Shao.

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

[Serum levels of levonorgestrel during long-term use of Norplant].

OBJECTIVE: (1) Assessment of longest effective contraceptive duration of Norplant (containing levonorgestrel, LNG) by serum levonorgestrel levels. (2) To observe the possible relationships between the serum LNG levels of long-term use (5 years) and body weight. METHODS: To determine serum LNG levels in 230 women among 1,356 cases at various intervals between 1 and 11 years after implantation using RIA kits provided by WHO. RESULTS: The average serum levels of LNG in users of Norplant at the 1st, 3rd, 5th years were 1,273.5, 924.0 and 739.6 pmol/L respectively. From the 5th to 7th years average serum LNG levels showed almost a linear decline, and from the 7th through 10th year it did not show much changes. The average serum LNG level was (511.1 +/- 209) pmol/L. A significant negative correlation was found between serum LNG levels and body weight at the 5th years. CONCLUSION: One set of Norplant implants may provide effective contraception for 8-10 years in women with body weights less than 60 kg.

Adult↗
PubMed1999

[Long-term efficacy of transurethral electrovaporization of the prostate for symptomatic benign prostatic hyperplasia].

OBJECTIVE: To observe long-term efficacy of transurethral electrovaporization of the prostate for symptomatic benign prostatic hyperplasia. METHODS: Two types of electrode of transurethral electrovaporization of the prostate (TVP) were performed on 150 patients of symptomatic BPH (mean age 74.8 years). The patients were assessed at baseline for both efficacy and followup at 36 months. Efficacy parameters evaluated included operation time (minutes), I-PSS and quality of life score, digital rectal examination, transrectal ultrasound, urodynamics and postvoid residual urine. RESULTS: 36 months after operation, I-PSS was decreased from 24.8 to 5.4 and the quality of life score also was decreased from 4.9 to 2.1. The mean peak uroflow was increased from 9.8 to 18.5 ml/s and postvoid residual urine was decreased from 108 ml to 22 ml (P < 0.05). The mean operation time was 44.7 min. Urodynamic results of 139 cases (92.7%) showed no bladder outlet obstruction, the remaining 11 cases showed severe bladder outlet obstruction to mild obstruction after 36 months. Hematuria was the only complication of our procedure. CONCLUSIONS: Significant clinical improvement is maintained with minimal morbidity. The long-term efficacy and safety of TVP is satisfactory. TVP is a potential useful procedure for transurethral resection of the prostate.

Aged↗
PubMed1999

[Observations on prostate histology in 50 young and middle aged men. Its implication on clinical pathological diagnosis].

OBJECTIVE: To investigate the morphology and the relationship between the prostate and the adjacent structures in order to clarify its significance in histopathological diagnosis. METHODS: By means of light microscopy, and in part by electron microscopy and immunohistochemistry, the histology of 50 normal prostates were observed. RESULTS: The parenchymal component can be divided into four zones, i.e. peripheral zone, central zone, transitional zone and periurethral gland region, each characterized by its own anatomical and histological features. CONCLUSION: This 4 zone division of prostate has more clinical significance than the traditional division of the prostate. A good knowledge of the normal structure of the prostate has great practical significance in pathologic diagnosis.

Acid Phosphatase↗
PubMed1999

[Hygienic appraisal on apartment houses in the western district of Beijing].

A survey on the essential factors of building hygiene of 12 apartment houses in the Western District of Beijing was presented. The site environment layout of rooms, illumination, ventilation, microclimate, indoor air quality, floor area per person, necessary equipped facilities etc, in the apartment, and its hygienic appraisal were assessed. The results and appraisal of the study showed that almost all the essential factors of building hygiene complied with the requirements of the national hygienic standards for air pollutants in indoors and in hotels. On the other hand, there existed some shortcomings, such as the gas appliance for heating water produced large amount of pollutants in the kitchen it there was no proper ventilation for it. Suggestions for their improvements were put forward. The appraisal is useful for improving the living conditions in apartment houses and also useful for the design and construction.

Air Pollution, Indoor↗
PubMed1999

[Study on proteins of allele by using the microisoelectric focusing].

Clear protein electrophoresis pattern of single pollen grain from Cucurbita pepo L. was obtained with isoelectric focusing and supersensitive stain technique. The results showed that there were two special distributing protein bands near acidity pole. In species I, the two protein bands were a little near to acidity pole and in species II, that was a little far from acidity pole. In species III, the two protein bands distributed either like species I or like species II and the distributed ratio was 1:1. Moreover, we discuss how to identify relative purity of gene with the sorts of the special proteins.

Alleles↗
PubMed1998

Ca2+ mobilization in adult rat cardiomyocytes by angiotensin type 1 and 2 receptors.

The role of angiotensin II (AngII) in the regulation of heart function under normal and pathological conditions has been well documented. Although two types of AngII receptors (AT1 and AT2 receptors) are found in equal proportions in the rat heart, most studies have focused primarily on AT1 receptor-coupled events. In this study, the contribution of both types of AngII receptors to cardiac function was evaluated by measuring intracellular calcium ([Ca2+]i) levels at ambient temperature in freshly isolated adult rat ventricular cardiomyocytes. Exposure of cardiomyocytes to AngII (0.01 to 10 microM) resulted in an immediate and sustained increase in [Ca2+]i in a concentration-dependent manner. The increase in [Ca2+]i in cardiomyocytes by AngII was blocked by either losartan or compound PD123319 (1-[[4-(dimethylamino)-3-methylphenyl]methyl]-5-(diphenylacetyl)- 4,5,6,7-tetrahydro-1H-imidazo[4,5-c]pyridine-6-carboxylic acid), non-peptide antagonists of the AT1 and AT2 receptors, respectively. The specificity of the action of these antagonists was verified by their inability to alter the basal levels of [Ca2+]i as well as KCl- or ATP-induced increases in [Ca2+]i. AngII was also observed to initiate spontaneous beating activity in cardiomyocytes, which was prevented by both losartan and compound PD123319 in a concentration-dependent manner (0.01 to 10 microM). These data indicate that the activation of both AT1 and AT2 receptors may stimulate a signalling pathway that influences [Ca2+]i and spontaneous beating activity in cardiomyocytes.

Adenosine Triphosphate↗
PubMed1998

Mechanism of depression in cardiac sarcolemmal Na+-K+-ATPase by hypochlorous acid.

Oxidative stress during pathological conditions such as ischemia-reperfusion is known to promote the formation of hypochlorous acid (HOCl) in the heart and to result in depression of cardiac sarcolemmal (SL) Na+-K+-ATPase activity. In this study, we examined the direct effects of HOCl on SL Na+-K+-ATPase from porcine heart. HOCl decreased SL Na+-K+-ATPase activity in a concentration- and time-dependent manner. Characterization of Na+-K+-ATPase activity in the presence of different concentrations of MgATP revealed a decrease in the maximal velocity (Vmax) value, without a change in affinity for MgATP on treatment of SL membranes with 0.1 mM HOCl. The Vmax value of Na+-K+-ATPase, when determined in the presence of different concentrations of Na+, was also decreased, but affinity for Na+ was increased when treated with HOCl. Formation of acylphosphate by SL Na+-K+-ATPase was not affected by HOCl. Scatchard plot analysis of [3H]ouabain binding data indicated no significant change in the affinity or maximum binding capacity value for ouabain binding following treatment of SL membranes with HOCl. Western blot analysis of Na+-K+-ATPase subunits in HOCl-treated SL membranes showed a decrease (34 +/- 9% of control) in the beta1-subunit without any change in the alpha1- or alpha2-subunits. These data suggest that the HOCl-induced decrease in SL Na+-K+-ATPase activity may be due to a depression in the beta1-subunit of the enzyme.

Adenosine Triphosphate↗
PubMed1998

Electrocardiographic Changes and Mortality Due to Myocardial Infarction in Rats With or Without Imidapril Treatment.

BACKGROUND: Various angiotensin-converting enzyme inhibitors are known to improve heart function and prolong survival in patients and animals after myocardial infarction. Because myocardial infarction is known to induce arrhythmias, this study tested the hypothesis that early treatment with the angiotensin converting enzyme inhibitor imidapril reduces mortality during acute myocardial infarction because of protective effects against arrhythmogenesis. METHODS AND RESULTS: Rats were randomly divided into four groups: sham control, myocardial infarction, sham plus imidapril, and myocardial infarction plus imidapril. Myocardial infarction was produced by ligation of the left anterior descending coronary artery. Treated rats received imidapril (1 mg/kg/day) through a gastric tube beginning 1 hour after coronary occlusion; control rats received tap water. Electrocardiogram (ECGs) were recorded 1, 3, 7, and 21 days postocclusion. Infarct size and scar weight were determined at 21 days in the myocardial infarction groups with and without imidapril treatment. ECGs of untreated rats showed ST-segment changes, abnormal Q waves, premature ventricular complexes, and QT(c) prolongation 1-21 days after coronary occlusion. Total mortality in 21 days averaged 35% in untreated rats; mortality within 48 hours was 30%. On the other hand, imidapril-treated rats showed fewer ST-segment changes, fewer abnormal Q waves, and a decreased incidence of premature ventricular complexes after coronary occlusion; the ST-segment and QT(c) interval returned to basal values within 1 week after occlusion. Imidapril treatment did not affect the ECG pattern in sham-treated control animals. Total mortality in the imidapril-treated group in 21 days after infarction was 22.5%; mortality within 48 hours was 20% (P <.05 compared with the untreated infarction group). Infarct size and scar weight caused by coronary occlusion did not differ in the untreated and imidapril-treated groups. CONCLUSIONS: Early treatment with imidapril markedly decreases mortality in rats after acute myocardial infarction. The lower mortality is not associated with a decrease in infarct size but is consistent with a protective effect of the drug against arrhythmogenesis.

Journal Article↗
PubMed1997

Differential changes in sympathetic activity in left and right ventricles in congestive heart failure after myocardial infarction.

Although congestive heart failure subsequent to myocardial infarction is known to be associated with increased sympathetic activity, very little information regarding changes in the sympathetic nerves in the left and right ventricles at various stages after infarction is available. Male Sprague-Dawley rats were subjected to coronary artery ligation and studied 4 and 8 weeks later; these animals had mild and moderate stages of congestive heart failure. A sham group, without coronary ligation, was used as control. Four weeks after myocardial infarction, plasma and ventricular (left and right) epinephrine (EPI), unlike norepinephrine (NE), were markedly increased. Whereas plasma catecholamine (EPI and NE) levels were increased 8 weeks after infarction, NE concentration in the left ventricle was unchanged but EPI concentration was increased in comparison with sham control. The right ventricle showed an increased level of both NE and EPI 8 weeks after infarction. Measurement of the rate of change in the specific activity of NE (NE turnover) in the left and right ventricles 8 weeks after infarction revealed an increase in NE turnover in the left ventricle, without any changes in the right ventricle. The concentration of EPI, unlike NE, was increased in the kidney, spleen, and brain 8 weeks after coronary occlusion. These results are interpreted to mean that congestive heart failure caused by myocardial infarction is associated with differential changes in the status of sympathetic nerves in the left and right ventricles; sympathetic activity is increased only in the left ventricle, whereas the right ventricle may play an adaptive role by increasing catecholamine stores during the development of heart failure.

Animals↗
PubMed1997

Adolescent dieting: healthy weight control or borderline eating disorder?

Dieting in adolescent girls is ubiquitous but its health significance is uncertain. On the one hand it might be seen as promoting healthy weight control and on the other it might be considered as a risk factor for eating disorders. Dieting levels were systematically assessed in a representative group of 2525 Australian teenagers and classified using item response theory. In this group, 38% of girls and 12% of boys were categorised as intermediate dieters; 7% of girls and 1% of boys fell into a group of extreme dieters. Body mass carried a strong positive association with intermediate dieting. Most female dieters, nevertheless, fell within a normal weight range. Psychiatric morbidity was the clearest factor associated with extreme dieting and 62% of extreme dieters reported high levels of depression and anxiety. Extreme dieting might reasonably be viewed as lying on a spectrum with clinical eating disorders. Most dieting is unjustified on the grounds of appropriate weight control and appears to reflect a widespread striving of teenage girls towards body shapes at the lower end of age-adjusted norms.

Adolescent↗
PubMed1997

Fura-2 fluorescent technique for the assessment of Ca2+ homeostasis in cardiomyocytes.

Ca2+ homeostasis plays a pivotal role in maintaining cell growth and function. Many heart diseases are related to the abnormalities in Ca2+ mobilization and extrusion. Ca2+-sensitive fluorescent dyes have been used successfully to estimate intracellular free Ca2+ ([Ca2+]i) level and the mechanisms of Ca2+ movements in living cells. This article is focused on the methodology involving the use of Fura-2/AM or free Fura-2 to measure agonist-induced Ca2+ mobilization as well as the mechanisms of changes in [Ca2+]i in cardiomyocytes. Methods involving Fura-2 technique for the measurement of Ca2+ extrusion from the cells and Ca2+ reuptake by sarcoplasmic reticulum (SR) are also described. The prevention of KCl-induced increase in the intracellular Ca2+ is shown by chelating the extracellular Ca2+ with EGTA or by the presence of Ca2+-channel inhibitors such as verapamil and diltiazem. The involvement of SR in the ATP-induced increase in intracellular Ca2+ is illustrated by the use of Ca2+-pump inhibitors, thapsigargin and cyclopiazonic acid as well as ryanodine which deplete the SR Ca2+ storage. The use of 2-nitro-4-carboxyphenyl N,N-diphenyl carbamate (NCDC), an inhibitor of inositol 1,4,5-trisphosphate (IP3) production, is described for the attenuation of phosphatidic acid (PA) induced increase in Ca2+-mobilization. The increase in intracellular Ca2+ in cardiomyocytes by PA, unlike that by KCl or ATP, was observed in diabetic myocardium. Thus, it appears that the Fura-2 method for the measurement of Ca2+ homeostasis in cardiomyocytes is useful in studying the pathophysiology and pharmacology of Ca2+ movements.

Animals↗
PubMed1996

Neuropeptide Y modulation of sympathetic activity in myocardial infarction.

OBJECTIVES: We examined the possible effect of neuropeptide Y in modulating central sympathetic activity after myocardial infarction in rats. BACKGROUND: Previous studies have shown the coexistence of neuropeptide Y and norepinephrine in the brain and a possible functional interaction between the two. Neuropeptide Y inhibits the release of norepinephrine at the presynaptic level and can be considered to act as a neuromodulator. METHODS: Two groups of rats were examined in this study-an experimental group, defined as those rats undergoing left coronary artery ligation, and a sham group without coronary artery ligation, serving as the control group. The animal in both groups underwent microdialysis in the paraventricular nucleus at 2, 4 and 8 weeks after operation. Microdialysis samples were collected with and without injecting neuropeptide Y in the paraventricular nucleus. The concentration of norepinephrine was determined by injecting purified microdialysate samples during high performance liquid chromatography. To explore the receptor's possible role, autoradiographic localization of neuropeptide Y receptors in the paraventricular nucleus was also carried out in the experimental and sham groups. RESULTS: The concentration of norepinephrine measured in the samples was decreased by 50% with neuropeptide Y in 2- and 4-week old rats after infarction, but by only 20% (p < 0.05) in 8-week old rats after infraction. The diminished inhibitory effects of neuropeptide Y on norepinephrine release was associated with increased sympathetic activity, as reflected by plasma norepinephrine; 8-week old rats after infarction had almost a 100% (p < 0.05) increase in their plasma norepinephrine level compared with the sham group. Autoradiography revealed a significant decrease in density of neuropeptide Y receptors in the paraventricular nucleus in 8-week old rats after infarction (p < 0.05). CONCLUSIONS: The data presented in this report suggest that the reduction of the inhibitory activation of neuropeptide Y on sympathetic release may contribute to elevated norepinephrine levels after myocardial infarction.

Animals↗
PubMed1996

Effect of hepatocyte growth factor/scatter factor on lipogenesis in adult rat hepatocytes in primary culture.

Hepatocyte growth factor (HGF)/scatter factor is known to be the most potent mitogen for hepatocytes. In this paper, we report that lipogenesis in primary cultured rat hepatocytes treated with 10 ng/ml of recombinant human HGF (rhHGF) for 24 h was stimulated, as measured by the incorporation of 3H2O into long-chain fatty acids, to more than twice as much as the control. Insulin (0.1 microM) was more effective than rhHGF but rhHGF did not show an additive or synergistic effect when added to insulin. We also showed that treatment with rhHGF increased the activities of glucose-6-phosphate dehydrogenase (G6PDH) and malic enzyme, key enzymes which supply NADPH for lipogenesis, and acetyl-CoA carboxylase, the rate-limiting enzyme of lipogenesis. The increase in G6PDH and acetyl-CoA carboxylase activities was accompanied by increases in the levels of mRNA for the enzymes. These results suggest that HGF is involved in liver regeneration not only by stimulation of cell proliferation but also by acceleration of differentiation of hepatocytes.

Acetyl-CoA Carboxylase↗
PubMed1996

Menarche and the onset of depression and anxiety in Victoria, Australia.

STUDY OBJECTIVE: Psychiatric disorder often begins at adolescence. This study aimed to examine the associations between puberty and social circumstances and the adolescent rise in depression and anxiety. DESIGN: A two stage cluster sampling procedure was used to identify a representative group of Australian secondary school students in years 7 (age 12-13 years), 9 (14-15 years), and 11 (16-17 years) of 45 Victorian schools. The computerised clinical interview schedule (CIS) was used to evaluate psychiatric morbidity. MAIN RESULTS: A total of 2525 subjects completed the survey - an overall participation rate of 83%. Levels of depression and anxiety increased with the secondary school years and girls had significantly higher rates at each school year level. For boys, the clearest independent associations with depression and anxiety were rising school year level and high parental educational achievement. For girls menarchal status emerged as the strongest predictor. Associations with age and school year level, evident on univariate analysis, did not persist when the recency of menarche was taken into account. After addition of measures of perceived social stress to a multivariate model, a significant association between depression/anxiety and parental divorce disappeared but the association with menarche persisted. CONCLUSIONS: Menarche marks a transition in the risk of depression and anxiety in girls. The pattern of findings is consistent with a biological mediation of this association.

Adolescent↗
PubMed1996

Phosphatidic acid increases intracellular free Ca2+ and cardiac contractile force.

Although phosphatidic acid (PA) is mainly formed due to the hydrolysis of phosphatidylcholine by myocardial phospholipase D, its functional significance in the heart is not fully understood. The present study was designed to determine the effects of PA on intracellular free Ca2+ level ([Ca2+]i) in freshly isolated adult rat cardiomyocytes by using fura 2-acextoxmethylester and free fura 2 technique. Addition of PA at concentrations of 1-200 microM produced a concentration-dependent increase in [Ca2+]i from the basal level of 117 +/- 8 nM; maximal increase in [Ca2+]i was 233 +/- 50 nM, whereas median effective concentration (EC50) for PA was 45 +/- 1.2 microM. This increase in [Ca2+]i was abolished by the removal of extracellular Ca2+ with ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid and was partially attenuated by Ca2+ channel blockers, verapamil or diltiazem. Preincubation of cardiomyocytes with cyclopiazonic acid and thapsigargin or with ryanodine [to deplete sarcoplasmic reticulum (SR) Ca2+] attenuated the PA-induced increase in [Ca2+]i by 66, 37, and 43%, respectively. Furthermore, the response of [Ca2+]i to PA was blunted by 2-nitro-4 carboxyphenylcarbonate, an inhibitor of phospholipase C, but was unaffected by staurosporine, a protein kinase C inhibitor. PA was also observed to induce Ca2+ efflux from the myocytes. In addition, an injection of PA (0.34 microgram/100 g body wt i.v.) in rats produced a significant increase of the left ventricular developed pressure as well as the maximum rates of cardiac contraction and relaxation within 5 min. These data suggest that the PA-induced increase in [Ca2+]i in cardiomyocytes is a consequence of both Ca2+ influx from the extracellular source and Ca2+ release from the intracellular SR stores. Furthermore, these in vitro data suggest the possibility that PA may regulate [Ca2+]i and contractile parameters in the heart.

Animals↗
PubMed1996

[A phase III multicentre study on medical termination of early pregnancy with two regimens of mifepristone followed by PG05].

OBJECTIVE: To compare use-effectiveness and side-effects of medical termination of early pregnancy by oral administration of separated doses of mifepristone 150 mg or single dose of mifepristone 200 mg followed by PG05 1 mg vaginally in 4500 healthy pregnant women with amenorrhea < or = 49 days in a phase I multicentre study. METHODS: All subjects were recruited in 30 clinics after obtaining informed consents. RESULTS: The complete, incomplete abortion and continuous pregnancy rates were 88.6%, 8.1%, 1.7% and 92.0%, 5.8%, 0.8% in single dose and separated doses groups, respectively. The efficacy of termination of early pregnancy by mifepristone 150 mg in separated doses was higher than that in single dose of mifepristone 200 mg when both in combination with PG05 1 mg (P < 0.01). One case of allergic rash was noted after administration of mifepristone. No severe side-effects were observed except bleeding problems. 65 cases received emergency vacuum aspiration and 7 of them received blood transfusion due to heavy bleeding. In addition, 2 cases of ectopic pregnancies required blood transfusion as heavy bleeding caused by exfetation disruption. There was no significant difference in to the time to start bleeding and the days of bleeding lasted between two treatment groups. However, there was a significant positive correlation (P < 0.001) between diameters of SAC and the days of bleeding lasted. CONCLUSIONS: Logistic regression analysis suggested that subject's age, gravidity and days of amenorrhea have significant effects on abortion efficacy. 75.2% of subjects are satisfactory in self-assessment of the treatment, and 81.8% of subjects will choose medical abortion method in case they need to terminate undesired early pregnancy in the future.

Abortifacient Agents, Nonsteroidal↗
PubMed1995

Myosin light chain phosphorylation in cardiac hypertrophy and failure due to myocardial infarction.

The regulatory myosin light chain (MLC) is phosphorylated in cardiac muscle by Ca2+/calmodulin dependent myosin light chain kinase (MLCK) and is considered to play a modulatory role in the process of force generation. In order to determine changes in MLC phosphorylation in cardiac hypertrophy and heart failure, the relative content of MLCK and MLC phosphorylation in the cardiac muscle from both sham control and experimental rats were assessed at 4 and 8 weeks following ligation of the left coronary artery. Changes in the relative MLCK content were measured by electrophoresis and immunoblot assay whereas phosphorylated and unphosphorylated MLC were separated by non-denaturing 10% acrylamide/urea gel and identified by Western blotting. The relative amount of MLCK was increased by 20-35% in the viable left ventricle, right ventricle and septum from the 8-week experimental rats in comparison to the respective control values. The MLC phosphorylation increased significantly in the right ventricle and septum but decreased markedly in the viable left ventricle from 8-week experimental rats in comparison to the control values. No appreciable changes in the relative amount of MLCK and MLC phosphorylation were seen between control and experimental rats at 4 weeks. These results suggest duration and region specific changes in the levels of MLCK and MLC phosphorylation in cardiac hypertrophy and heart failure subsequent to myocardial infarction.

Animals↗