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Biomedical subjects

D Zheng

Publications and source records attributed to D Zheng.

At least 55 records · Page 3Linked to original sources
PubMed2000

[The common C677T polymorphism in the methylenetetrahydrofolate reductase gene is associated with neural tube defects and preeclampsia].

OBJECTIVE: To assess whether methylenetetrahydrofolate reductase(MTHFR) gene C677T polymorphism is associated with neural tube defects and preeclampsia. METHODS: Twenty- four mothers who had given birth to normal children, 27 mothers who had given birth to NTDs children, 120 normal women, and 57 women who had suffered from preeclampsia were genotyped for C677T polymorphism by using PCR/RFLP method. RESULTS: (1) VV genotype frequency in the normal mothers group it was 0.13, while in the NTDs mothers group it was 0.33; mothers with VV genotype were at 3 times increased risk to have a NTDs child, compared with the normal mothers. (2) In the normal women group VV genotype frequency was 0.15, while in the preeclampsia women group it was 0.31; women with VV genotype were at 2.5 times increased risk to have preeclampsia, compared with the normal women. CONCLUSION: The authors believe that MTHFR VV genotype is associated with the development of NTDs and preeclampsia.

Female↗
PubMed2000

Muscle glucose transporter (GLUT 4) gene expression during exercise.

Among the many effects of exercise is the induction of glucose transporter (GLUT 4) expression in skeletal muscle. In this review, we examine the intracellular signals that may mediate the exercise-induced increase in GLUT4 gene transcription. This induction is likely to be dependent upon intracellular calcium concentrations and the energy charge of the muscle.

AMP-Activated Protein Kinases↗
PubMed2000

Aristolochic acid I-induced apoptosis in LLC-PK1 cells and amelioration of the apoptotic damage by calcium antagonist.

OBJECTIVE: To examine the effect of different concentrations of aristolochic acid I (AAI) in inducing apoptosis of cultured porcine renal cell line LLC-PK1 and to investigate the relationship between intracellular free calcium concentration ([Ca++]i) and LLC-PK1 apoptosis induced by AAI and the influence of a calcium antagonist, lacidipine on apoptosis and [Ca++]i. METHODS: LLC-PK1 cells were treated in different groups: a. the normal group without treatment; b. the group with AAl alone (0.01 g.L-1, 0.02 g.L-1, 0.04 g.L-1, 0.08 g.L-1); c. the group with lacidipine alone (10 ng.L-1, 10(2) ng.L-1, 10(3) ng.L-1); d. the group with AAI (0.04 g.L-1) plus lacidipine (10 ng.L-1, 10(2) ng.L-1, 10(3) ng.L-1). Light microscopy, agarose gel electrophoresis, Annexin-V-Flous apoptosis detection kit and flow cytometry using propidium iodide staining to identify or quantify the apoptosis of LLC-PK1 cells. Mean [Ca++]i was measured by laser confocus microscopy using Fluo-3/AM staining. RESULTS: A series of morphologic changes that were characteristic of apoptosis, Annexin-V-Flous staining positive apoptotic cells and "DNA ladder" were identified in AAI (0.02 g.L-1-0.08 g.L-1) treated LLC-PK1 cells. Quantitative analysis of apoptotic cells showed that the percentage of apoptotic cells in AAI (0.02 g.L-1, 0.04 g.L-1 or 0.08 g.L-1) group was significantly higher than that in normal group (5.3%, 48.5%, 78.7% vs 2.6%, P < 0.001). Mean [Ca++]i was significantly higher in cells treated with AAI (0.04 g.L-1) than that in normal cells (58.01 +/- 18.89 vs 22.66 +/- 4.78, P < 0.001). In group treated with AAI plus lacidipine (102 ng.L-1, 103 ng.L-1), mean [Ca++]i was significantly lower than that treated with AAI alone (35.47 +/- 12.85, 28.55 +/- 10.16 vs 58.01 +/- 18.89, P < 0.001). And the percentage of apoptotic cells in group treated with AAI plus lacidipine (10(2) ng.L-1, 10(3) ng.L-1) was also significantly lower than that treated with AAI alone (19.0%, 27.8% vs 34.7%, P < 0.001). CONCLUSIONS: High concentrations of AAI may induce apoptosis of LLC-PK1 cells. The mean [Ca++]i in AAI-treated LLC-PK1 cells was increased significantly, suggesting that the increase of [Ca++]i may be related to apoptosis in LLC-PK1 cells. Lacidipine may decrease the raised mean [Ca++]i levels caused by AAI and the percentage of apoptotic cells, and lacidipine may ameliorate AAI-induced apoptotic damage by inhibiting the increase of [Ca++]i in LLC-PK1 cells.

Animals↗
PubMed2000

[Clinical study on hemorrheologic changes for metastatic state of gastric cancer and its relationship with syndrome-type in traditional Chinese medicine].

OBJECTIVE: To explore the hemorrheologic changes of gastric cancer in various stages, and the relationship between different phases and Syndrome-types. METHODS: Sixty-three gastric cancer patients and 30 healthy controls matching in sex and age were studied. According to the phases of tumor and the differentiation standards of deficiency and excess syndrome in TCM, the patients were divided into 6 groups: Non-metastasis (NM), lymphnode metastasis (LM), distant metastasis (DM) groups, and Deficiency (D), Excess (E), mixed deficiency and excess (DE) groups. The hemorrheology criteria including whole blood viscosity (BV), plasma viscosity (PV), hematocrit (HCT), fibrinogen (Fib), platelet count (PC), platelet aggregation rate (PAR) were measured. RESULTS: The value of BV, PV, Fib, PC and PAR in gastric cancer groups were higher significantly (P < 0.05, P < 0.01) than those in the healthy control group, but BV, PV in the LM and DM groups were higher than those in the healthy control group significantly (P < 0.05), while difference between NM group and the healthy control group was insignificant (P > 0.05). Hypercoagulability state presented in all the three Syndrome Type groups of gastric cancer patients, but the difference in some criteria between D and E group were significant (P < 0.05, P < 0.01); and DE groups was greatly higher than D and E groups in high-shear BV, Fib and PC (P < 0.05, P < 0.01). CONCLUSION: The value of BV, PV Fib, PC and PAR could be regarded as good referential parameters in reflecting the condition of evil excess.

Adult↗
PubMed2000

[The disinfection efficiency comparison of different treatments on dental impression and gypsum casts].

OBJECTIVE: In this study, the disinfecting efficiency of five disinfecting methods to three bacterial: Staphylococcus epidermidis, Streptococcus sanguis and Bacillus subtilis were evaluated. METHODS: Germ free impressions and gypsum casts were divided into three teams contained 16 impressions and 5 gypsum casts for each one. Each team was smeared with each one of the three bacterial solutions. Then four disinfecting methods were administrated on these impressions separately, 2% glutaraldehyde immersion, 2% glutaraldehyde spray, 5% Eric immersion, 5% Eric spray. And ozone treatment was administrated on gypsum casts. Control teams were set up. After the treatment the impressions and gypsum casts were sampled at standard sites. The colonies were counted after culture and were used to deduce the germicidal ratio as the standard of disinfecting efficiency. RESULTS: There was no difference between the efficiencies of five disinfecting methods for Streptococcus sanguis and Staphylococcus epidermidis. But for B. subtilis, the immersion methods have the highest efficiency among the methods and the ozone treatment has the least efficiency. CONCLUSION: 2% glutaraldehyde immersion, spray, 5% Eric immersion, spray are all effective disinfecting methods for impressions and ozone treatment is an effective method in disinfecting the gypsum casts.

Bacillus subtilis↗
PubMed2000

[Expression and kinase activity of B-Raf and Raf-1 in leukemia cell lines].

OBJECTIVE: To study expression and kinase activity of B-Raf and Raf-1 kinases in several leukemia cells and normal peripheral blood lymphocytes. METHODS: Western blot was carried out to detect expression of B-Raf and Raf-1 in peripheral blood lymphocytes and leukemia cells. Kinase activities of Raf-1 and B-Raf were analyzed by immunoprecipitation and Western blot. RESULTS: The expression levels of Raf-1 were similar in tested leukemia cells and normal peripheral blood lymphocytes, and Raf-1 protein was all minimally tyrosine-phosphorylated. B-Raf expressed in all tested leukemia cells, but not in normal peripheral blood lymphocytes, and B-Raf was highly activated in Jurkat and K562 leukemia cells. CONCLUSION: The abnormal expression and kinase activity of B-Raf in leukemia cells might be related to leukemia etiologically.

Humans↗
PubMed1999

A PCR method for typing B-L beta II family (class II MHC) alleles in broiler chickens.

Certain haplotypes of the major histocompatibility (B) complex are strongly associated with resistance or susceptibility to several infectious diseases in Leghorn chickens. Identification of chicken haplotypes based on the nucleotide sequence of B complex loci could provide more precise identification of haplotypes than traditional serological methods. We report the development and application of polymerase chain reaction with sequence specific primers (PCR-SSP) to type broiler chicken B haplotypes based on the DNA sequence of B-L beta II family genes. Five well-defined standard B haplotypes from White Leghorns and 12 recently characterized B haplotypes from a broiler breeder line were used to develop the test system. The B-L beta II family loci were amplified from genomic DNA by B-L beta II family specific primers and then characterized by PCR-SSP. In total, ten pairs of primers, derived from the sequences of expressed B-L beta II family alleles, were used in the PCR typing test to discriminate the chicken B haplotypes identified previously by serological means. The PCR-SSP showed that each haplotype had a different amplification pattern, except those haplotypes known or suspected to have the same B-L beta alleles. Cloning and sequencing of the family specific PCR products indicated that two loci in the B-L beta II family, presumably B-L beta I and B-L beta II, were amplified. Finally, B-L beta PCR-SSP typing was used in combination with B-G RFLP analyses to characterize unusual (variant) B serotypes; the results indicate that some of these are natural recombinants within the B complex.

Alleles↗
PubMed1999

Regulation of skeletal muscle UCP-2 and UCP-3 gene expression by exercise and denervation.

The factors that regulate gene expression of uncoupling proteins 2 and 3 (UCP-2 and UCP-3) in skeletal muscle are poorly understood, but both genes are clearly responsive to the metabolic state of the organism. Therefore, we tested the hypothesis that denervation and acute and/or chronic exercise (factors that profoundly affect metabolism) would alter UCP-2 and UCP-3 gene expression. For the denervation studies, the sciatic nerve of rat and mouse hindlimb was sectioned in one leg while the contralateral limb served as control. Northern blot analysis revealed that denervation was associated with a 331% increase (P < 0.001) in UCP-3 mRNA and a 200% increase (P < 0. 01) in UCP-2 mRNA levels in rat mixed gastrocnemius (MG) muscle. In contrast, denervation caused a 53% decrease (P < 0.001) in UCP-3 and a 63% increase (P < 0.01) in UCP-2 mRNA levels in mouse MG. After acute exercise (2-h treadmill running), rat UCP-3 mRNA levels were elevated (vs. sedentary control) 252% (P < 0.0001) in white gastrocnemius and 63% (P < 0.05) in red gastrocnemius muscles, whereas UCP-2 levels were unaffected. To a lesser extent, elevations in UCP-3 mRNA (22%; P < 0.01) and UCP-2 mRNA (55%; P < 0.01) levels were observed after acute exercise in the mouse MG. There were no changes in either UCP-2 or UCP-3 mRNA levels after chronic exercise (9 wk of wheel running). These results indicate that acute exercise and denervation regulate gene expression of skeletal muscle UCPs.

Animals↗
PubMed1999

Effect of endurance exercise on myosin heavy chain gene regulation in human skeletal muscle.

The purpose of this study was to determine the effect of endurance-oriented exercise on myosin heavy chain (MHC) isoform regulation in human skeletal muscle. Exercise consisted of 1 h of cycle ergometer work per day at 75% maximal oxygen consumption for seven consecutive days. Muscle was obtained before the first bout of exercise, 3 h after the first bout of exercise, and before and 3 h after the final exercise bout on day 7 (n = 9 subjects). No changes in MHC mRNA (I, IIa, IIx) were evident after the first exercise period. There was, however, a significant (P < 0.05) decline (-30%) in MHC IIx mRNA 3 h after the final training bout. An interesting finding was that a higher pretraining level of MHC IIx mRNA was associated with a greater decline in the transcript before (r = 0.68, P < 0.05) and 3 h after (r = 0.82, P < 0.05) the final exercise bout. These findings suggest that MHC IIx mRNA is downregulated during the early phase of endurance-oriented exercise training in human skeletal muscle but only after repeated contractile activity. Pretraining MHC IIx mRNA content may influence the magnitude of this response.

Adult↗
PubMed1999

Impact of hyperinsulinemia on myosin heavy chain gene regulation.

The purpose of this study was to determine whether hyperinsulinemia alters myosin heavy chain (MHC) gene expression in human skeletal muscle. A biopsy from the vastus lateralis was obtained in young, lean [age 24.6 +/- 1.0 (SE) yr, body fat 11.9 +/- 1.9%, body mass index 26.1 +/- 1.1 kg/m2; n = 10] men before and after 3 h of hyperinsulinemia (hyperinsulinemic-euglycemic clamp). Muscle was analyzed for mRNA of type I, IIa, and IIx MHC isoforms. Hyperinsulinemia (mean of 1,065.7 +/- 9.8 pmol/l during minutes 20 to 180) did not change (P > 0.05) the mRNA concentration of either the type I MHC or type IIA MHC isoforms. In contrast, type IIX MHC mRNA increased (P < 0.05) with hyperinsulinemia compared with the fasted condition. These data indicate that hyperinsulinemia rapidly increases type IIx MHC mRNA in human skeletal muscle.

Adult↗
PubMed1999

The role of the renin-angiotensin and cardiac sympathetic nervous systems in the development of hypertension and left ventricular hypertrophy in spontaneously hypertensive rats.

To elucidate the relationship between the development of left ventricular hypertrophy (LVH) in hypertension and the development of both the cardiac sympathetic nervous and renin-angiotensin systems, as measured by norepinephrine and angiotensin II levels, respectively. In this longitudinal study, we compared blood pressure (BP), left ventricular weight, and norepinephrine (NE) and angiotensin II (Ang II) concentrations, in Spontaneously Hypertensive Rats (SHR) and age-matched Wistar-Kyoto (WKY) rats at 5, 10, 15, 20, and 28 wk of age. Blood pressure, plasma and ventricular Ang II and tissue NE were measured by the tail-cuff method, radioimmunoassay, and high-performance liquid chromatography (HPLC), respectively. At 5 wk, systolic blood pressure was the same in both strains. But the left ventricular plus septum weight to body weight (LVSW/BW) ratio was higher in SHR than in WKY rats (p < 0.01), which finding may have been related to the increased cardiac tissue NE concentration, and this increase tended to parallel the rise in blood pressure. Both left ventricle and forelimb muscle NE concentrations were significantly higher in SHR than in WKY rats at 5, 10, and 15 wk of age (p < 0.01, respectively), and were similar at 20 and 28 wk of age. The heart and plasma Ang II levels decreased with age, which results were in keeping with the known developmental tendencies of the biological aging progress. There was no significant difference in plasma Ang II levels between the two strains from 5 to 20 wk, whereas these levels were remarkably higher in WKY than in SHR rats at 28 wk (p< 0.01). Otherwise, the left ventricular tissue Ang II concentrations were significantly higher in SHR than in WKY rats at the late stage (from 15 to 28 wk), which may have contributed to the late-stage cardiac hypertrophy. These results suggested that the sympathetic nervous system (SNS) and the renin-angiotensin-system (RAS) in SHR may contribute to the pathogenesis of hypertension and LVH at the early and late stages, respectively.

Animals↗
PubMed1999

An A/G polymorphism in the promoter of mitochondrial aldehyde dehydrogenase (ALDH2): effects of the sequence variant on transcription factor binding and promoter strength.

INTRODUCTION: The strong protective effect of the ALDH2*2 mutation on risk of alcoholism suggests that other mutations that reduce mitochondrial aldehyde dehydrogenase (ALDH) activity in the liver might also deter drinking. This study describes a polymorphic locus found in the promoter of the ALDH2 gene that affects expression of reporter constructs. METHODS: Polymerase chain reaction (PCR)-based sequencing was used to search for polymorphisms. The ability of the promoter variants to bind transcription factors apolipoprotein A regulatory protein 1 (ARP-1) and chicken ovalbumin upstream promoter-transcription factor (COUP-TF) was tested in gel retardation assays using in vitro synthesized transcription factors. The variant promoters were tested for transcriptional activity using a heterologous promoter system and transient transfection assays. RESULTS: A common polymorphism (A or G) in the human ALDH2 promoter region was found at -361 base pair (bp) from the translation start site. This polymorphism was found at different frequencies in African Americans, Caucasians, and Asians. The polymorphism occurs adjacent to the core binding motif for the transcription factors COUP-TF and ARP-1. Competition and binding affinity determinations did not show differences in the ability of these two sequences to bind the factors. Reporter genes containing these elements upstream of a basal thymidine kinase promoter had similar activity when transfected into a fibroblast (CV-1) cell line. However, the reporter containing the G allele was more active than that containing the A allele in hepatoma (H4IIEC3) cells. CONCLUSIONS: The -361 bp A/G polymorphism is common in all racial groups tested. The G allele was more active than the A allele in a transfection assay. The basis for this difference is not known. If the differences in activity of the promoter constructs were paralleled by differences in ALDH2 enzyme activity in the liver, this polymorphism could affect risk of alcoholism.

Aldehyde Dehydrogenase↗
PubMed1999

[Molecular clonging of the human dimethyglycine dehydrogenase-like gene (DMGDHL1) from the sarcosinemia critical region at 9q34].

Through the analysis of EST database, we obtained one human EST (GenBank: H28856) which showed significant similarity with the partial coding sequence of rat dimethylglycine dehydrogenase gene. This EST was mapped to 9q34 due to 95.6% identity with one genomic sequence (GenBank: AC002295). A pair of primers (HRP-1/HRP-2) designed on the sequence of the EST were coupled with the primers (lambda gt10-5/lambda gt10-3) on the vector flanking cloning site respectively to amplify the 5' and 3' cDNA beyond the EST. New primers designed based on novel cDNA sequence overlapped with the sequence within EST H28856 were used for amplification with lambda gt10-5 and lambda gt10-3 by the similar way as above untill a complete ORF was obtained. Finally, a 1,970 bp sequence (termed as dimethylglycine dehydrogenase like gene isoform I, DMGDHL1a) containing a 1,428 bp complete coding sequence from the live cDNA library and 1,475 bp sequence (isoform II, termed as DMGDHL1b) containing a 1,296 bp complete coding sequence from the fetas live cDNA library were obtained. Fourteen exons were identified in isoform I and the first nine exons of isoform II which shared with isoform I could be determined too. The last 105 bp cDNA sequence of isoform II could not be found in the public database, indicating a very large intron (> 123 kb) existed between exon 9 and exon 10 of isoform II. DMGDHL1 showed highly homology on both cDNA and amino acid level with rat dimethylglycine dehydrogenase (60% identity in 135 bp and 35% identity in 436 residues respectively). It was reported that human sarcosinemia gene was mapped at 9q34. Therefore it could be a good candidate gene for the sarcosinemia.

Amino Acid Sequence↗
PubMed1999

[The effect of chlamydia trachomatis infection in pregnant women on pregnant outcome and neonates].

OBJECTIVE: To determine the prevalence of chlamydia trachomatis (CT) in pregnant women and its effect on pregnant outcome and neonate. METHODS: Specimen of cervical swab were collected and detected for CT by polymerase chain reaction (PCR) method meanwhile relevant factors were investigated. Pregnant outcome and neonatal situation were also followed up. RESULTS: The infection rates of CT in pregnant women were 35.90%. The Incidence of abnormal pregnant outcome (premature delivery and abortion) was significantly higher in CT positive groups (24.72%) than that in negative groups (12.20%) (P < 0.05). Incidence of neonatal conjunctivitis and pneumonia were significantly higher in CT positive groups (17.98%) than that of negative groups (0.61%) (P < 0.01). There was statistically significant difference in the prevalence of low birth weight (< 2,500 g) between the two groups (13.48% versus 4.88%) (P < 0.05), and mode of delivery also had influence on neonatal morbidity. CONCLUSION: Prevalence of CT infection in pregnant women is rather common, and it may cause adverse pregnancy outcome.

Abortion, Spontaneous↗
PubMed1999

All-trans retinoic acid reduces intimal thickening after balloon angioplasty in atherosclerotic rabbits.

OBJECTIVE: To investigate the effects of oral administration of all-trans retinoic acid (ATRA) on inhibition of intimal thickening after balloon angioplasty in the rabbit iliac artery atherosclerotic model. METHODS: Iliac atherosclerosis was induced in 24 rabbits, and balloon angioplasty was performed. At angioplasty, 24 rabbits were randomly divided into four groups (n = 6 per group): Group 1: controls not receiving oral ATRA administration; Group 2: receiving oral ATRA (0.6 mg.kg-1.d-1) administration beginning 1 week prior to angioplasty and continuing for 4 weeks; Group 3: receiving oral ATRA (0.6 mg.kg-1.d-1) administration beginning immediately after angioplasty and continuing for 4 wk; Group 4: receiving oral ATRA (0.6 mg.kg-1.d-1) administration beginning 1 wk after angioplasty and continuing for 4 wk. Values of cross-sectional area, ratio of intimal/medial area and thickness were determined by a computer-based morphometric system, and cell proliferative activity was assessed by 3H-thymidine incorporation. RESULTS: Both the cross-sectional area and the ratio of intimal/medial area and thickness were significantly reduced by ATRA administration compared with control group (P < 0.01). The inhibitory effect is less potent when ATRA is administered 1 week before angioplasty. The ATRA inhibitory effect when administered 1 week after angioplasty is not different significantly form that when administered immediately after angioplasty. The 3H-thymidine incorporation was also decreased in ATRA-treated rabbits compared with controls (P < 0.01). CONCLUSIONS: Oral ATRA administration can be effective in inhibiting intimal thickening after balloon angioplasty. It is reasonable that ATRA should be administered immediately after angioplasty.

Angioplasty, Balloon↗
PubMed1999

[Light and electron microscope observations of heart and vascular tissues in animals acutely infected with tubercle bacilli].

The objective of this study was to observe the heart and vascular pathological lesions of some animals acutely infected with H37Rv tubercle bacilli. C57 BL/6N mice and rabbits were used for the establishment of the models. Light sections were stained with HE, Z-N, MCT and BCGS-P. Ultrathin sections were stained with uranyl and lead citrate and examined by electron microscope. The results showed that tubercle bacilli were present in heart and vascular tissues. Myocardial fibre, pericardium and vascular tissues had various degrees of lesions. The lesions of myocardial fibre and pericardium were more serious than that of the vascular tissues. These findings suggest that the toxin of the tubercle bacilli can damage the tissues of the infected animals, and the excessive reproduction can be also a factor detrimental to the infected tissues.

Acute Disease↗
PubMed1999

[Overexpression of Bcl-2 inhibited T lymphocyte apoptosis mediated by CD3 epsilon molecule].

OBJECTIVE: To study the role of bcl-2 gene overexpression in T lymphocyte apoptosis mediated by CD8 epsilon chimera molecule. METHODS: The cells expressed CD8 epsilon chimera molecule were transfected with a bcl-2 expression vector. The cells with Bcl-2 overexperssion were selected by G418 and limited dilution, and then treated with anti-CD8 antibody. The cell death was evaluated with flow cytometry. RESULTS: It was shown that there were only 2.6% of cells with Bcl-2 overexpression died by apoptosis. Comparing with Jurkat and TJK cells without Bcl-2 expression, in which there were 6.1% and 33.7% of cell death respectively, suggesting that Bcl-2 overexpression remarkbly inhibited apoptosis of the T lymphocytes mediated by CD8 epsilon chimera molecule. CONCLUSIONS: Bcl-2 overexpression could block T lymphocyte apoptosis mediated by CD3 epsilon molecule and the mechanisms remained to be clarified in detail.

Antibodies, Monoclonal↗