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Biomedical subjects

J Tang

Publications and source records attributed to J Tang.

At least 217 records · Page 12Linked to original sources
PubMed1999

[Genetic polymorphisms of five STR loci in a Chinese Han population].

OBJECTIVE: To understand the allele structure and genetic polymorphism at five STR loci in Chinese Han population, and construct a preliminary database. METHODS: EDTA-blood specimens were collected from the unrelated individuals. The DNA samples were extracted with Chelex method and were amplified by PCR technique. The PCR products were analyzed using both the PAGE horizontal electrophoresis with discontinuous buffer system and the automated fluorescence detection approach. RESULTS: Four STRs consist of simple repeat motifs, while one STR contains a complex repeat structure. The STR polymorphisms at all of the five loci have been observed in Chinese Han population. CONCLUSION: The obtained data are beneficial to understanding the population genetics of the five STR loci in Chinese Han population. As a simple approach, the PAGE horizontal electrophoresis can be employed for typing the five STR markers.

Alleles↗
PubMed1999

The impact of codon 54 variation in intestinal fatty acid binding protein gene on the pathogenesis of diabetes mellitus in Chinese.

OBJECTIVE: To investigate whether or not the intestinal fatty acid binding protein gene (FABP2)-Ala54Thr variation is related to non-insulin dependent diabetes mellitus (NIDDM), obesity, dyslipidemia and glucose stimulated insulin secretion (GSIS) in Chinese. METHODS: The FABP2-Ala54Thr variation was detected by PCR/Hhal digestion in 231 Chinese subjects (116 with normal glucose tolerance (NGT), 54 with impaired glucose tolerance (IGT) and 61 with NIDDM). Plasma glucose, insulin and C-peptide levels before and after 75 g glucose load as well as fasting lipid profile were determined. RESULTS: (1) The Ala54 and Thr54 allele frequencies in Chinese were 0.71 and 0.29 respectively; (2) The FABP2-Ala54Thr variation was neither associated with fasting and post-challenged plasma glucose levels nor with NIDDM; (3) This variation was neither associated with fasting lipid profile nor with obesity; (4) The IGT subjects with genotype Thr54(+) (Thr54 homozygotes and heterozygotes) had lower fasting, 2-hour and total C-peptide levels and smaller AUC representing lesser C-peptide secretion after glucose challenge than those with genotype Thr54(-) (Ala54 homozygotes) (P = 0.04, 0.03, 0.01 and 0.01 respectively). The serum insulin levels changed in the same tendency. CONCLUSIONS: The glucose stimulated insulin secretion (GSIS) reserve of islet beta-cells is more limited in subjects with FABP2-Thr54(+) genotype than in those with FABP2-Thr54(-) genotype. It suggests that FABP2-codon 54 variation might contribute to the insufficient insulin secretion in the development of NIDDM in Chinese.

Alanine↗
PubMed1999

Hyperhomocysteinemia and hyperlipidemia in coronary heart disease.

OBJECTIVE: To examine the relationship between coronary heart disease (CHD) and serum lipid, plasma homocysteine (HCY) as well as the factors related to HCY metabolisms. METHODS: The mutation of the 677C-->T transition of 5, 10-methylenetetrahydrofolate reductase (MTHFR) was determined by PCR-based assay. Whole-blood and plasma folate and plasma vitamin B12, as cofactors of MTHFR, were determined by radio-immunologic assay. Plasma HCY was determined by HPLC. RESULTS: Patients with CHD had elevated plasma HCY concentrations (17.38 +/- 1.94 mumol/L vs 10.25 +/- 1.57 mumol/L, P < 0.01). In patients with myocardial infarction (MI) and family history (FH) of CHD, plasma HCY were elevated even higher (P < 0.05). Plasma HCY concentrations had significant non-linear inverse correlation with plasma folate and B12 concentrations, i.e. the lower the serum folate or B12 concentrations, the higher the plasma HCY concentrations (P < 0.01). Patients with homozygous mutants had higher plasma HCY concentrations. Patients with CHD had increased serum Chol and LDL-C and Apo-B levels (P < 0.01, P < 0.05 and P < 0.05 respectively). But plasma HCY concentrations had no correlation with serum lipid levels. 24.1% of the patients had high lipid and high HCY level, 25.9% had high lipid level and normal HCY level, 20.4% had normal lipid and high HCY level, and 29.6% had normal lipid and HCY level. CONCLUSIONS: HCY may have strong association with the genesis of CHD. Low plasma folate and B12 concentrations may induce Hyperhomocysteinemia [HH(e)]. Plasma HCY concentrations have no correlation with serum lipid levels, so HCY may be an independent risk factor. CHD may be induced by different mechanisms and can be classified into hyperlipidemia, HH (e) and normolipidemia, and normohomocysteinemia.

5,10-Methylenetetrahydrofolate Reductase (FADH2)↗
PubMed1999

[Genetic polymorphisms of homocysteine metabolism related enzymes in patients with coronary heart disease].

OBJECTIVE: To study genetic polymorphisms of methylenetetrahydrofolate reductase (MTHFR) C677T and cystathionine beta-synthase(CBS) T833C related to homocysteine metabolism in patients with coronary heart disease (CHD). METHODS: 209 patients with CHD and 101 controls were selected. MTHFR genetic C677T polymorphism was determined by PCR-RFLP, and CBS T833C polymorphism by ARMS method. Plasma homocysteine levels were detected with HPLC. RESULTS: The frequencies of MTHFR T homogenetic type and heterogenetic type (27.8% and 45.4%) in case group were higher than those in normal group(22.8% and 34.6%). There were significant differences in the frequencies of genotypes and alleles between two groups (P < 0.05). C homogenotype of CBS gene was found in 21 patients, and 2 in the normal group. There were evident differences in the frequencies of genotypes and alleles of the two groups (P < 0.001). Moreover, plama homocysteine levels were markedly higher in patients with MTHFR or CBS genetic mutation than those in patients without mutation (P < 0.05). CONCLUSIONS: Hyperhomocysteinemia is an independent risk factor of CHD. MTHFR and CBS are the main enzymes related to homocysteine metabolism. Their genetic mutations are possibly important mechanism of hyperhomocysteinemia and coronary heart disease.

Adult↗
PubMed1999

[Association of serum leptin concentrations with blood pressure].

OBJECTIVE: To explore the relationship between serum leptin, hypertension, body mass index (BMI) and energy metabolism. METHODS: Serum leptin concentrations were measured by radioimmunoassay. Blood pressure (BMI) blood sugar (Glu), triglycerides (TG), total cholesterol (TC), LDL, HDL, BUN, Cr and Ur were determined in 64 men with essential hypertension (EHT) and 54 male normotensives (NT). The correlation between leptin and other parameters were analyzed. RESULTS: (1) Serum leptin concentrations n = 118 (3.3 +/- 1.9) micrograms/L in 118 subjects were significantly correlated with SBP, DBP, BMI, Glu, TG, TC and LDL(P < 0.05-P < 0.001). (2) Serum leptin concentrations were strongly correlated with BMI in both EHT and NT groups (P < 0.001). The concentration level was significantly higher in EHT group n = 64 (3.8 +/- 1.9) micrograms/L than in NT group n = 54, (2.8 +/- 1.3) micrograms/L, P < 0.01). The difference in serum leptin concentrations between the two groups disappeared when BMI and age were corrected by analysis of covariance. In NT group, serum leptin concentrations were correlated with SBP (P < 0.05). (3) If the cases of overweight, underweight, hyperglycemia, hyperglyceridemia were excluded, serum leptin concentrations were still highly correlated with BMI, but no longer related to blood pressure. CONCLUSION: Serum leptin concentrations are not directly related to blood pressure, but the concentration levels are actually correlated with the degree of obesity and energy metabolism.

Blood Pressure↗
PubMed1999

Serum leptin levels and adiposity in adult Chinese: a preliminary observation.

OBJECTIVE: To establish normal serum leptin levels in Chinese and investigate the relationship between serum leptin levels and body fat, gender, age and androgen. METHODS: Serum leptin levels were measured in 77 lean (BMI < 25) and 28 overweight or obese (BMI > or = 25) subjects by a radioimmunoassay (RIA) method. RESULTS: The serum leptin levels in lean Chinese were 2.15 +/- 1.46 ng/ml in male and 7.85 +/- 3.60 ng/ml in female, which are similar to those of Caucasians, while in overweight or obese ones, the levels were 4.87 +/- 3.47 ng/ml and 16.59 +/- 6.92 ng/ml respectively, lower than those in Caucasians. A 2-3 times higher leptin concentrations were found in women than in men in both conditions. Even when the number of lean males was expanded to 79 subjects aged from 17-80 years, no significant leptin-age relationship was found. Despite 25% of obese subjects manifested a relative deficiency of leptin, as a whole, leptin levels in both men and women were significantly correlated with BMI (r = 0.69, P < 0.001 in male and r = 0.63, P < 0.001 in female). CONCLUSIONS: Serum leptin levels in Chinese lean people are similar to those in Caucasians and in both lean and obese groups, the leptin levels are correlated with BMI, suggesting that the great majority of the obese patients are resistant to endogenous leptin. Those who are relatively deficient of leptin may become a group of good candidates for leptin treatment in the future.

Adult↗
PubMed1999

[Alternation of the level of plasma calcitonin gene related peptide and endothelin-1 in liver cirrhosis].

OBJECTIVE: To investigate the level of plasma calcitonin gene related peptide (CGRP) and endothelin-1 (ET-1) to assess their role on portal hypertension formation and progression and liver function injury in liver cirrhosis and the possible relation between them. METHODS: CGRP and ET-1 were measured in plasma samples collected from 24 healthy controls and 61 liver cirrhosis patients. RESULTS: Plasma CGRP and ET-1 level were significantly higher in cirrhotic patients than those in healthy controls. Comparisons of the levels of plasma CGRP and ET-1 in group of patients with different liver function were shown as follows: Child C > Child B > Child A. An analysis among the groups showed that plasma CGRP and ET-1 were markedly higher in the groups with esophageal varices accompanied by severe or moderate ascites (LC(4)) and with simple severe or moderate ascites (LC(3)) than in the groups with esophageal varices accompanied by mild or no ascites (LC(2)). The levels were also significantly higher in group LC(2) than those in group without varices and ascites (LC(1)). No statistical difference of plasma CGRP and ET-1 levels was found between group LC(1) or Child A and normal controls. There was positive correlation between plasma CGRP and ET-1. The increased concentration of both of them correlated negatively with the declined level of plasma albumin. CONCLUSION: The increase of plasma CGRP and ET-1 is closely associated with the severity of liver cirrhosis and the formation and progression of portal hypertension. The disturbance of the balance between plasma CGRP and ET-1 may contribute to the pathologic process of liver injury.

Adult↗
PubMed1999

[Association of Gln223Arg variant in leptin receptor gene with metabolic abnormalities and hypertension in type II diabetes mellitus in Shanghai "Han" population].

OBJECTIVE: To investigate the association of Gln223Arg variant in leptin receptor gene with metabolic abnormalities and hypertension in type II diabetes mellitus. METHODS: The genotypes of Gln223Arg variant in leptin receptor gene were determined by polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP) assay in 359 unrelated subjects of Shanghai "Han" population (including 193 subjects with normal glucose tolerance and 166 type II diabetic patients). The clinical data were also analyzed. The parameters for regional adipose tissue distribution were measured by magnetic resonance imaging (MRI). RESULTS: Significant difference of genotype frequency of Gln223Arg variant in leptin receptor gene was observed between hypertensive and normotensive type II diabetic male patients (P = 0.008). "A" allele was associated with increased systolic blood pressure (P = 0.0026) and diastolic blood pressure (P = 0.0084) in type II diabetic male patients. Logistic regression analysis showed that this gene variant was an independent risk factor of type II diabetic male patients accompanied with hypertension (P = 0.0031), and it was associated with elevation of systolic blood pressure (P = 0.0054). The odds ratio of hypertension in type II diabetic male patients with "A" allele was 2.825 (95% CI 1.418, 5.627). CONCLUSION: Gln223Arg variant in leptin receptor gene is associated with hypertension in type II diabetic male patients, especially with elevation of systolic blood pressure.

Adult↗
PubMed1999

[Dynamic effect of the blood glucose and insulin on serum leptin concentration during oral glucose tolerance test].

OBJECTIVE: To investigate the effects of internal change of plasma glucose and serum insulin levels on serum leptin concentrations during oral glucose tolerance test (OGTT) in normal subjects and type II diabetics (DM). METHODS: Plasma glucose, serum insulin and leptin concentrations were measured simultaneously in 50 age, sex and body mass index matched non-diabetic (non-DM) and 50 DM subjects who were undergoing OGTT. RESULTS: The fast serum leptin concentrations were (3.88 +/- 0.64) microg/L in DM males and (8.30 +/- 1.06) microg/L in DM females. Respectively they were (5.01 +/- 0.64) microg/L and (10.48 +/- 1.30) microg/L in non-DM group. No significant difference was revealed. Comparing with the non-DM group, the glucose curve was elevated and the insulin releasing curve was characterized by a low response and a delayed peak in DM group. As for the leptin releasing curve, both groups showed a decreasing trend, which seemed to be more evident in DM group. CONCLUSION: Leptin concentration does not increase with the release of insulin. On the contrary, it shows a diurnal rhythmic descending trend, suggesting that in vivo, the insulin effect on serum leptin concentration is relatively weak and not able to affect the day-time descending trend of leptin levels.

Blood Glucose↗
PubMed1999

[Detection and proliferation of hemorrhagic fever virus in chigger mites].

OBJECTIVE: To study the impact of Leptotromhidium scutellaris as a vector in transmission of hemorrhagic fever. METHODS: Reverse transcription-polymerase chain reaction (PCR) and in situ hybridization technique were used to detect RNA of hemorrhagic fever with renal syndrome virus (HFRSV). TCID(50)/ml of HFRSV were titrated for larva and nymph of chigger mites periodically. RESULTS: RNA of HFRSV was detected in the tissues of chigger mites, such as ovary cells, etc. by PCR and in situ hybridization. Titration of TCID(50)/ml showed that HFRSV could be transmitted transstadially and proliferated in chigger mites. CONCLUSION: It provides direct evidence at molecular level for the role of chigger mite as a vector in transmission of HFRSV with theoretical and practical importance in prevention of HFRS.

Animals↗
PubMed1999

[Preservation of hearing and facial nerve function after Gamma knife therapy for acoustic neurinomas].

Thirty-five patients with acoustic neurinomas were treated by Gamma knife from Sept. 1995 to Oct. 1997. Neuroimaging studies performed in 21 patients with more than 12 months showed that tumor size decreased in 9(43%) cases, unchanged in 11(51%) cases, and increased in 1(15%) case. The tumor growth control and regression rates were 95% and 43%, respectively. Some hearing was preserved in four patients (36%) who had hearing prior to Gamma knife treatment. There was new transient facial weakness in five patients(23%), and there was new trigeminal neuropathy after treatment in one patient (4.8%). These findings indicate that Gamma knife therapy is a safe and effective management for acoustic neurinomas, especially in preventing facial function and hearing.

Adolescent↗
PubMed1999

[Methodological study on the assay of glycosylphosphatidylinositol-specific phospholipase D activity in serum].

A method for the assay of glycosylphosphatidylinositol-specific phospholipase D(GPI-PLD) activity in human serum was established by using glycosylphosphatidylinositol(GPI) anchored placental alkaline phosphatase(PLAP) as a substrate. Serum GPI-PLD activity was determined both qualitatively and quantitatively by PEG/dextran and triton-X-114 partitioning respectively, and some kinetic properties of its enzymatic reaction were also studied. This method revealed a satisfactory reproductivity(CV = 3.6%) and a high sensitivity(2 microliters serum was sufficient). In addition, it is practical, economical, and feasible to be widely applied. The activities of GPI-PLD measured by this method in 100 normal subjects ranged from 30% to 50% (in terms of the percentage of converting GPI anchored PLAP substrate to the anchor-free product).

Adult↗
PubMed1999

[Analysis of the relationship between the facial skin temperature and blood flow].

The relationship between the blood flow of temperal or facial artery and facial skin temperature was studied in 30 patients with facial nerve paralysis. The facial skin temperature was recorded by infrared thermography, and the blood flow was measured by ultrasonic Doppler flowetry. The results showed, in the same facial region, the greater the volume of blood flow was, the higher the skin temperature stood. After acupuncture on the facial points, the facial blood flow increased and the facial skin temperature rose. The ratios between the increase in facial skin temperature and the in increase in blood flow were 0.9538-1.2835(degrees:ml/second) in four facial regions. These indicate the presence of certain quantitative relationship between the facial blood flow and the skin temperature.

Adult↗
PubMed1999

[C677T genetic polymorphism of methylenetetrahydrofolate reductase in premature coronary heart disease].

OBJECTIVE: Methylenetetrahydrofolate reductase (MTHFR) is an important factor responsible for hyperhomocysteinemia. The relation of MTHFR gene C677T polymorphism and premature coronary heart disease was studied. METHODS: MTHFR C677T genetic polymorphisms in 67 patients with premature coronary heart disease were detected by PCR-RFLP technique. RESULTS: In case group, the frequency of T homogenic type was 34.3% (23/67), heterogenic type 43.3% (29/67) and C homogenic type 22.4% (15/67). T allele frequency was 55.9% (75/134) while C allele frequency 44.1% (59/134) in case group. There were significant differences in MTHFR genotype and allele frequencies between cases and controls (chi 2 = 6.82 and 5.41 respectively, P < 0.05). CONCLUSIONS: It was suggested that MTHFR gene C677T mutation was a possible risk factor of Chinese premature coronary heart disease.

Adult↗
PubMed1999

Peripheral tissue distribution of orphanin FQ precusor mRNA in stroke-prone spontaneously hypertensive rats.

The heptadecapeptide orphanin FQ (OFQ) is a recently discovered neuropeptide that exhibits structural features reminiscent of the opioid peptides and that is an endogenous ligant to a G protein-coupled receptor sequentially related to the opioid receptors. OFQ was originally isolated from brain, but the presence of OFQ in peripheral tissues, especially in cardiovascular system, has not been clarified. The present study was designed to investigate the peripheral tissue distribution of OFQ precusor mRNA in stroke-prone spontaneously hypertensive rats (SHRSP) and compare the difference of OFQ precusor mRNA expression in aorta or cultured vascular smooth muscle cells (VSMCs) between SHRSP and wistar-Kyoto normotensive (WKY) rats. By using quantitative reverse transcription-polymerase chain reaction (RT-PCR), OFQ precusor mRNA was detected in aorta and ovary at high levels comparable with the amounts found in brain. Moderate expression was found in testis, while a little OFQ precusor mRNA could be detected in atrium. All other peripheral tissues examined from SHRSP, including ventricle, liver, lung and kidney, showed no expression of OFQ precusor mRNA. In the vascular system, OFQ precusor mRNA was expressed in aorta, pulmonary artery, renal artery and vein at high levels comparable with the amounts found in brain. We also found that OFQ precusor mRNA levels were much higher in aorta or cultured VSMCs from SHRSP than those from WKY rats. In conclusion, the present study has shown that OFQ precusor mRNA is present in some peripheral tissues, especially in cardiovascular and reproductive system, suggesting that OFQ possibly involves in the regulation of cardiovascular and reproductive functions.

Animals↗