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Biomedical subjects

X L Wang

Publications and source records attributed to X L Wang.

At least 19 recordsLinked to original sources
PubMed1995

Angiotensin-converting enzyme genotype in children and coronary events in their grandparents.

BACKGROUND: It has been suggested that the insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene is an independent risk factor for coronary artery disease. The D/D genotype, which is associated with higher levels of circulating ACE than the I/D or I/I genotype, has been found significantly more frequently in patients with myocardial infarction and also in individuals with a parental history of myocardial infarction. METHODS AND RESULTS: We explored the distribution of the ACE genotype in 404 school children, aged 6 to 13 years, and related the distribution to the number of their grandparents who had had vascular events. We found a significant association between the number of grandparents who had had coronary events and the ACE genotype (P = .01). In children with two or more grandparents who had had coronary events, there was an excess of both D/D (odds ratio = 2.8 [95% confidence interval = 1.16-6.56]) and I/D (odds ratio = 1.4 [95% confidence interval = 0.62-3.25]) genotypes compared with I/I genotypes. In addition, there was an association between the ACE genotype and lipoprotein(a) levels in children (P = .07). Both the ACE genotype and lipoprotein(a) were found to contribute significantly (P = .0042) and independently to family history of coronary artery disease, with the ACE genotype proving to be more predictive than lipoprotein(a) levels. CONCLUSIONS: We conclude that the I/D polymorphism of the ACE gene is an important independent risk factor for coronary artery disease and is more predictive that lipoprotein(a). The I/D polymorphism is not only associated with a parental history of myocardial infarction but also with coronary artery disease in second-degree relatives. A further study to explore the relation between the I/D polymorphism and circulating levels of lipoprotein(a) is indicated.

Adolescent↗
PubMed1995

C to T and/or G to A transitions are responsible for loss of a MspI restriction site at the 5'-end of the human apolipoprotein AI gene.

We detected the loss of a MspI restriction site by a C to T transition at +83 bp and a G to A transition at +84 bp of the 5'-end non-coding region of the human apolipoprotein AI gene. This base change occurred at the "hot spot" (CCGG) for methylation, which may be important in the regulation of gene expression. The population frequency for the loss of the MspI site is 6.1%.

Alleles↗
PubMed1995

Study of the optimal duration of preoxygenation in children.

STUDY OBJECTIVE: To determine the optimal length of preoxygenation in children. DESIGN: Random design and comparison among groups. SETTING: Operating room of a plastic surgery hospital of the Chinese Academy of Medical Sciences and the Peking Union Medical College. PATIENTS: Forty healthy, ASA status 1 children (age 2 to 7 yrs), undergoing elective plastic surgery. INTERVENTIONS: Children in Group 1 breathed 100% oxygen (O2) for 1 minute. Group 2 children breathed 100% O2 for 2 minutes. Group 3 and Group 4 children breathed 100% O2 for 3 minutes. Anesthesia was induced with midazolam 0.3 mg/kg, fentanyl 5 micrograms/kg. Muscle relaxation was achieved with vecuronium 0.1 mg/kg (Groups 1, 2, and 3) or succinylcholine 1.5 mg/kg (Group 4). MEASUREMENTS AND MAIN RESULTS: Oxygen saturation (SpO2) was measured by pulse oximeter. The oximeter probe was applied to the right big toe. After preoxygenation, the times for SpO2 to decrease to 98% (T98), 95% (T95), and 90% (T90), respectively, were recorded during the apneic period. T98, T95, and T90 were significantly shorter in Group 1 than in Group 2 or Group 3. There was no statistically significant difference among Groups 2, 3, or 4 regarding T98, T95, and T90. The times for SpO2 to decrease from 95% to 90% were similar among the four groups. CONCLUSIONS: 2 minutes of preoxygenation in children can provide the maximum benefit of denitrogenation and achieve 2 minutes of safe apea. 95% and 99% confidence intervals were 69 to 100 and 59 to 100, respectively. Succinylcholine had only a slight effect on the safe apneic period.

Anesthesia↗
PubMed1995

Polymorphisms of the apolipoprotein E gene and severity of coronary artery disease defined by angiography.

In a recent study, we could account for only about 50% of the variance in angiographically determined severity of coronary artery disease (CAD) with use of lipid and clinical variables as predictors. To explore the possible contribution of the apolipoprotein (apo) E polymorphisms to the severity of CAD (rather than to its occurrence), we studied 424 white patients aged 65 years or less consecutively referred for coronary angiography. Among the 304 male and 120 female patients, there were 110 with no significant CAD and 118 with one, 96 with two, and 100 with three significantly diseased major coronary arteries (> 50% luminal obstruction). The allele frequencies were 0.068 for E2, 0.759 for E3, and 0.172 for E4. The E2 frequency was slightly lower and E4 higher than the frequencies reported for healthy white populations (E2: 0.072 to 0.130; E4: 0.136 to 0.160). There was a clear association between the apo E genotype and the number of significantly diseased vessels (regression coefficient = .12, P = .008). The frequency of the E4 allele increased linearly with the increase in CAD severity in both sexes (for none, one, two, and three significantly diseased vessels; female patients: 0.136, 0.161, 0.200, and 0.324; male patients: 0.136, 0.167, 0.132, and 0.229, respectively, P < .01). The frequencies of the E2 allele, on the other hand, decreased with increasing severity (for none, one, two, and three significantly diseased vessels; female patients: 0.091, 0.018, 0.050, and 0.029; male patients: 0.073, 0.089, 0.072, and 0.054, respectively, P < .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Apolipoproteins E↗
PubMed1995

[Experimental study on effect of sanchaning in treating primary trigeminal neuralgia].

Sanchaning is an empirial prescription in treating primary trigeminal neuralgia (PTN). Pills of this prescription have been applied to animal models in an experimental study and their effects were compared with that of distilled water as well as carbamazepine, a common Western medicine for curing PTN. The indexes, including the attack number of PTN of the model animals, the duration of the spontaneous reaction and the positive time of the induced response, showed that Sanchaning differed significantly from distilled water in treating PTN (P < 0.01), but slightly differed from that of carbamazepine (P < 0.05). The sequential trial has identified that Sanchaning could be used effectively to inhibit PTN and has the same effect as carbamazepine. But further study should be carried out to investigate the mechanism of its function in relieving PTN.

Animals↗
PubMed1995

[Effect of yishen jianpi drugs on T lymphocyte subsets, soluble interleukin-2 receptor and red blood cell immunity of senile deficiency syndrome patients].

UNLABELLED: To evaluate the effect of Yishen Jianpi drugs (YJD) on immunological function of the Senile Deficiency Syndrome (SDS) patients, T lymphocyte subsets, soluble interleukin-2 receptor (SIL-2 R), the red blood cell immunity, the rate of red blood cell C 3b receptor rosette (RBC-C 3 bRR) and red blood cell immune complex rosette (RBC-ICR) were dynamically investigated in 31 SDS patients as well as in normal controls. RESULTS: the percentage of CD3, CD4 and CD4/CD8 ratio and the rate of RBC-C 3 bRR in SDS were all significantly lower than that of control (P < 0.01). The further analysis also revealed that between the immunological indices of CD4/CD8 ratio and SIL-2 R in SDS patients were markedly negative correlated (r = -0.572, P < 0.01) while positive correlated (r = 0.435, P < 0.02) markedly between CD4/CD8 and RBC-C 3 bRR. After treatment with YJD, in comparing pretreatmentally, all the above-mentioned immunological indices, following the relief of clinical manifestation of SDS, they were corresponding negatively changed, and there were marked significance (P < 0.01) except red blood cell immunity. It suggested that YJD would markedly improve and/or regulate immunological function in SDS.

Aged↗
PubMed1994

Studies on the properties of myo-inositol-1,4,5-trisphosphate 5-phosphatase and myo-inositol monophosphatase in bovine iris sphincter smooth muscle: effects of okadaic acid and protein phosphorylation.

In bovine iris sphincter, myo-inositol 1,4,5-trisphosphate (IP3) 5-phosphatase and myo-inositol 1-phosphate (IP1) monophosphatase are mainly localized in the microsomal and soluble fractions, respectively. Studies on the properties of these enzymes can be summarized as follows. (1) The microsomal IP3 5-phosphatase hydrolyzed IP3 to myo-inositol 1,4-bisphosphate with an apparent Km of 28 microM and Vmax of 32 nmol/min per mg protein. The IP1 monophosphatase in the soluble fraction hydrolyzed IP1 into free inositol with an apparent Km of 89 microM and Vmax of 7 nmol/min per mg protein. (2) IP3 5-phosphatase and IP1 monophosphatase had optimal pH values at 8.0 and 7.0, respectively. (3) Both enzymes required Mg2+ and their highest specific activities were at a cation concentration of 2 mM. (4) Ca2+ (> 0.5 microM) exerted an inhibitory effect on IP3 5-phosphatase activity, and marked inhibition (47%) was observed at a concentration of 10 microM. Higher concentrations of the cation (> 100 microM) were required to inhibit IP1 monophosphatase. (5) IP1 monophosphatase, but not IP3 5-phosphatase, was inhibited by Li+. Li+ had no effect on the contractile response in this smooth muscle. (6) Both enzymes were inhibited by ATP and by the thiol-blocking agent, disulfiram. In addition, thimerosal, a thiol reagent, also inhibited the IP3 5-phosphatase activity. (7) Protein phosphorylation of the microsomal and soluble fractions with PKA or PKC had no effect on the activities of these enzymes. (8) Okadaic acid, a protein phosphatase inhibitor, had no effect on the activity of IP3 5-phosphatase. However, in the intact iris sphincter the toxin significantly reduced the carbachol-induced IP3 production, 1,2-diacylglycerol formation, measured as phosphatidic acid, and caused muscle relaxation.

Animals↗
PubMed1994

Run-down of calcium current is related to intracellular sodium.

Run-down of Ca2+ current was studied in isolated guinea pig ventricular cells and it was found to be attenuated by intracellular sodium. Calcium currents were recorded after activation of Na+ channels by a step pulse. The "run-down" in 30 min was significantly reduced compared with control cells. When NaCl (0.1-10 mM) diffused from the micropipette into the cells, run-down of Ca2+ current was also significantly attenuated. However, the resulted increase of intracellular Na+ did not affect voltage dependent activation of Ca2+ current, but the duration of the action potential was shortened slightly.

Action Potentials↗
PubMed1994

Experimental study on anti-tumor effect of splenocytes induced by anti-CD3 McAb, PHA and IL-2.

The proliferation of splenocytes from healthy adults was induced by anti-CD3 McAb, PHA and IL-2. The proliferative capability and anti-tumor activity as well as phenotypes of the splenocytes cultured in different medium systems were studied. The results showed that anti-CD3 McAb and PHA not only enhanced the proliferation of splenocytes induced by IL-2, but also produced synergism if used simultaneously. The expressions of CD4 and Tac of cellular surface markers were increased after splenocytes were induced by anti-CD3 McAb and PHA. The results of anti-tumor activity of LAK cells suggested that PHA had the capability to promote anti-tumor activity of LAK cells by both direct and indirect pathways, but anti-CD3 McAb indirectly promoted anti-tumor activity of LAK cells by enhancing splenocyte proliferation.

Antibodies, Monoclonal↗
PubMed1994

The relationship between infant and parent Lp(a) levels.

Since atherogenesis may begin in childhood, and elevated serum lipoprotein(a) (Lp(a)) concentrations increase cardiovascular risk, we explored the early expression of the apolipoprotein(a) (apo(a)) gene and relationships between infants' and parents' serum levels. In a consecutive series of 1032 babies aged 3-5 days the distribution of apo(a) levels was positively skewed as in adults but with lower levels: 50th and 95th percentiles were the equivalent of 30 mg/l and 130 mg/l of Lp(a) in serum. Concentrations were re-measured in 51 infants when aged 8.5 +/- 2 months together with parental values. Levels at 3-5 days and 8.5 months were highly correlated (r = 0.73, P < 0.0001, n = 51) with a twofold increase at 8.5 months. Regression coefficients between 8.5 months concentrations and those of fathers, of mothers and the average level of both parents were 0.439, 0.521 and 0.93, respectively (P < 0.0001 for each), and infant and parental levels were then not different. The positive and negative predictive values of first post-natal week capillary blood apo(a) measurements detecting a parent with serum Lp(a) above 300 mg/l were 95% and 70%. We conclude that the apo(a) gene is virtually fully expressed before 1 year during which apo(a) levels track closely and are predictive of parental values. Childhood Lp(a) measurements may identify families at enhanced cardiovascular risk and facilitate targeted prevention.

Adult↗
PubMed1994

A protease activation mutant, MVCES1, as a safe and potent live vaccine derived from currently prevailing Sendai virus.

Sendai virus fresh isolates were shown to be antigenically different from the prototype Fushimi strain that had long been passaged in embryonated chicken eggs. Phylogenetic analysis of the hemagglutinin-neuraminidase genes also revealed the difference between these two virus groups. Both trypsin-resistant and elastase-sensitive mutations were additionally introduced to an LLC-MK2-cell-adapted and attenuated mutant derived from one of the fresh isolates. This protease activation mutant (MVCES1) showed the same antigenicity as the fresh isolates, and as a result of a single cycle of growth in lungs, it could confer better protection on mice against challenge infection with the currently prevailing Sendai virus than TR-5, which is a trypsin-resistant mutant derived from the Fushimi strain. The eligibility of MVCES1 as an attenuated live vaccine of Sendai virus is discussed.

Amino Acid Sequence↗
PubMed1994

Determinants of severity of coronary artery disease in Australian men and women.

BACKGROUND: Factors predicting the occurrence of premature coronary artery disease (CAD) may not be quantitatively the same as those predicting CAD severity, particularly in women, in whom there have been few studies. METHODS AND RESULTS: To determine factors predictive of severity of CAD and of angina pectoris, we documented atherogenic variables and the extent of CAD at angiography in 594 consecutively studied men and women aged 65 years or less. Severity was assessed from the number of involved major coronary arteries with significant (> 50%) luminal obstructions and from a coronary disease severity score. We related severity to quantitative and categorical atherogenic variables and assessed severity of angina (no angina, stable angina, or unstable angina) at the time of study in the same way. There were eight variables independently predictive of severity: in descending order of relative importance, male gender, diabetes, smoking dose, ratio of total cholesterol to high-density lipoprotein cholesterol (TC/HDL-C), lipoprotein(a) [Lp(a)], age, positive family history, and hypertension. These correctly classified 43.3% of patients into no-, one-, two-, and three-vessel disease categories and accounted for 25.8% of variance of severity. Among 246 patients not taking lipid-lowering or beta-blocking drugs, these variables (in slightly different order) correctly classified 49.2% of patients and accounted for 36% of the variance. Among men (n = 427), seven significant variables correctly classified 39.3% of patients compared with 54.5% in women (n = 167). For those not taking the above drugs, these proportions were 49.4% and 65.4%, respectively. Among the quantitative variables, total smoking dose was the most predictive independent variable irrespective of current or ex-smoking habit and was more predictive in women than in men; of the lipid variables, high TC/HDL-C (or low HDL-C) and high Lp(a) were consistently highly predictive for all patients and in the subgroup analyses. Patients with unstable angina had higher coronary severity scores and Lp(a) levels and were more likely to have diabetes, hypertension, or a positive family history. CONCLUSIONS: We conclude that the quantitative variables most relevant to severity of premature CAD and to its prevention in Australian men and women are total amount of lifetime smoking, TC/HDL-C (or HDL-C), and Lp(a) and that patients with unstable versus stable angina usually have more severe disease and higher Lp(a).

Cholesterol↗
PubMed1994

Altered alpha 1-adrenoceptor density and alpha 1A/alpha 1B ratio in rat hearts after propranolol treatment.

After rats were treated with propranolol (50 mg.kg-1, bid, ip) for 7 d, the density of alpha 1-adrenoceptors in the rat myocardial cell membranes increased from 137 +/- 25 to 178 +/- 30 fmol/mg protein determined by receptor radioligand assay. Whereas the KD value was not significantly changed, the relative proportion of alpha 1A-adrenoceptor subtype increased from 19 +/- 6 to 31 +/- 8%. The affinities of two subtypes to 5-methylurapidil were not obviously changed after propranolol treatment. It was suggested that alpha 1A-subtype was more important in alpha 1-receptor mediated alterations after beta-adrenoceptor blockade.

Adrenergic alpha-Antagonists↗
PubMed1994

[Comprehensive evaluation of inheritance and environmental factors in the etiology of primary liver cancer].

A1:1 matched case-control study was carried out in 152 cases with primary liver cancer (PLC) and 152 controls to identify the risk factors associated with it and its cumulative mortality in their second- and third-degree relatives. Results showed cumulative mortality of PLC in the relatives of the cases (0.46%) was significantly higher than that of controls (0.07%). Cumulative mortality of PLC in consanguineous relatives of the cases (0.55%) was significantly higher than that in non-consanguineous ones (0.08%). Cumulative mortality of PLC decreased regularly with family relation (consanguinity) drifting apart. Genetic factors still played an important role independently in the etiology of PLC with multiple regression and stratification analyses studying genetic and environmental factors as a whole. This laid a theoretical basis to study further the association between genetic factors and PLC incidence.

Case-Control Studies↗
PubMed1994

[On the central inhibition action of tetrahydroberberine without relevance to GABA receptors].

Using an earthworm (Eisenia foetida) dorsal muscle preparation, it was shown that tetrahydroberberine (THB, 10(-7)-10(-4) mol/L) did not affect both GABA and ACh receptors. DA receptor antagonist haloperidol (HAL) also exerted no effect. Owing to the blocking action of isonicotinyl hydrazine (INH) and thiosemicarbazide (TSC) on biosynthesis of GABA, and of picrotoxin (PT) and bicuculline (Bic) on the GABA-BZ receptor complex mediated transmission, all these agents could induce convulsion in mice. This action could be antagonized by amino- oxyacetic acid (AOAA) and benzodiazepine (BZ), but not by DA receptor antagonists THB and HAL. All the above observations indicate that the GABA inhibition is not involved in the central action of THB.

Animals↗
PubMed1994

[An experimental study on dental pulp histology after the inferior alveolar nerve damage and autogenous nerve graft].

The dental pulpal histology was studied experimentally in rabbits after the inferior alveolar neurovascularity damage and nerve graft. The results revealed that the dental vitality was gradually repaired at different intervals after the inferior alveolar neurovascularity damage. In the early damaged period the pulpal blood vessels were reduced in number and some of them were swollen and permeable, in the late period the structure of the microvascular system became normal and abundant. The pulpal architecture was altered in the initial stage and with the tendency to repair gradually. The pulpal axon degenerated in early stage and reinnervated later. The authors indicate that there are no evident affections for dental pulpal tissues whatever the inferior alveolar neurovascularity is damaged and repaired. This has an important clinical value to define the dental pulp vitality in mandibular subapical osteotomy and tumor resection.

Animals↗
PubMed1994

[Preliminary screening of Chinese herbal medicine in inhibiting Helicobacter pylori].

At present Helicobacter pylori (HP) was taken to be closely related to chronic atrophic gastritis and peptic ulcer. 226 patients with symptoms of upper digestive tract by endoscope were examined and chronic atrophic gastritis and peptic ulcer were diagnosed. Mucous membrane from gastric antrum was taken and cultured, and found that 136 cases of 226 patients were HP positive and the rate of positiveness was 60.18%. 200 kinds of Chinese herbal medicine were selected to investigate its inhibitory action on HP. Results indicated that 38 among 200 kinds of Chinese herbal medicine had inhibitory effects on HP, which provided evidence for diagnosis and treatment of chronic atrophic gastritis and peptic ulcer, also for inhibition of HP growth.

Adolescent↗