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Biomedical subjects

Ming Chen

Publications and source records attributed to Ming Chen.

At least 109 records · Page 6Linked to original sources
PubMed2004

Effect of different vibration frequencies on heart rate variability and driving fatigue in healthy drivers.

OBJECTIVE: This investigation was to assess the effect of different vibration frequencies on heart rate variability (HRV) and driving fatigue in healthy subjects during simulated driving, by the use of power spectrum analysis and subjective evaluation. MATERIALS AND METHODS: Sixty healthy subjects (29.6+/-3.3 years) were randomly divided into three groups, A, B and C, and the subjects of each group participated in the simulated driving for 90 min with vertical sinusoidal vibration (acceleration 0.05 g) of 1.8 Hz (group A), 6 Hz (group B) and no vibration (group C), respectively. Low-frequency (LF) and high-frequency (HF) components of HRV, reflecting sympathetic and parasympathetic activities, and the LF:HF ratio, indicating sympathovagal balance, were measured throughout all periods. All indices of HRV were calculated in the pre-experiment period, mid-experiment period and end-experiment period, and were analyzed by repeated measures analysis of variance. Subjective responses to a questionnaire were obtained after the simulated task for the three groups. RESULTS: Significant differences in all indices of HRV were observed between different experiment periods and between any two groups. The ratings of subjective fatigue exhibited significant differences between any two groups. CONCLUSION: The drivers' fatigue ratings were associated with vibration frequencies in simulated driving. The study quantitatively demonstrated that different effects on autonomic nerve activities were induced by different vibration frequencies.

Adult↗
PubMed2004

STCDB: Signal Transduction Classification Database.

The Signal Transduction Classification Database (STCDB) is a database of information relative to the classification of signal transduction. It is based primarily on a proposed classification of signal transduction and it describes each type of characterized signal transduction for which a unique ST number has been provided. This document presents, in its first version, the classification of signal transduction in eukaryotic cells. Approved classifications are available for web browsing at http://www.techfak.uni-bielefeld.de/~ mchen/STCDB.

Animals↗
PubMed2004

Trisomy 13 mosaicism: study of serial cytogenetic changes in a case from early pregnancy to infancy.

We report a patient whose chorionic villus sampling showed a nonmosaic trisomy 13 [46,XX,der(13;13)(q10;q10)]. Subsequent amniocentesis and cordocentesis showed varying percentages of abnormal cells (77 and 78% in two amniocentesis; 14% in cordocentesis) and mosaic trisomy 13 was impressed. Prenatal fetal ultrasound scanning revealed only mild structural abnormalities (echogenic cardiac foci, transient lemon head, transient skin oedema). The mother chose to continue the pregnancy. Karyotyping of the cord blood, peripheral blood, umbilical cord, urine, and chorion were performed postpartum. The process of correction appeared to exist in the placenta (indirect evidence from coexistence of trisomy 13 [46,XX,der(13;13)(q10,q10)], euploidy [46,XX], aneuploidy [46,XX,-13, +mar], and monosomy 13 [45,XX,-13] in the chorion at birth). The baby had survived beyond eight months of age at the time of submission. Few structural abnormalities except low-set ears, absence of the 12th rib, and cardiomegaly with ventricular septal defect, were noted postnatally. The growth reached 95th percentile at the age of one month. Development milestones were not delayed at serial evaluations. Her ventricular septal defect was corrected surgically at the age of six months. Karyotypes of her skin fibroblasts, blood lymphocytes, and cardiac tissue were all normal [46,XX] at the time of surgery. Difficulties of the genetic counseling are also discussed.

Adult↗
PubMed2004

Reducing the effects of driving fatigue with magnitopuncture stimulation.

The purpose of this study was to assess the effects of reducing driving fatigue with magnitopuncture stimuli on Dazhui (DU14) point and Neiguan (PC6) points using heart rate (HR), reaction time (RT) testing, right rate (RR), critical flicker fusion frequency (CFF) and subjective evaluation. Forty healthy subjects were randomly divided into two groups: study and control groups. All subjects were required to be well rested before the experiment. The subjects were engaged in high speed driving at a constant vehicle velocity of 80 km/h continuously for 3h on a test course simulating an expressway. During the driving magnitopunctures (Haci Five Elements Needle, 250 mT, made by Haci Company limited) were applied to the Dazhui (DU14) point and Neiguan (PC6) points for the study group when the subject performed the task for 2.5h, and for the control group magnitopunctures were applied to non-acupuncture points during the same time session. The results of this study show a significant effect of magnitopuncture stimuli on RT, RR and CFF. Subjective evaluation also exhibited significant differences (P < 0.05) between the two groups after the driving task. The findings showed that magnitopuncture stimuli on DU14 point and PC6 points could reduce the effects of driving fatigue.

Acupuncture Points↗
PubMed2004

Radiation therapy concurrent with weekly paclitaxel for locoregionally advanced nasopharyngeal carcinoma: outcomes of a phase I trial.

PURPOSE: The purpose of this study was to define the maximum tolerated dose (MTD) by describing the dose-limiting toxicity (DLT) of paclitaxel given as a 3-hour intravenous infusion concurrently with conventional radiotherapy in patients with locoregionally advanced nasopharyngeal carcinoma (NPC). MATERIALS AND METHODS: Patients with locoregionally advanced NPC were enrolled into a dose-escalating study. Toxicity was graded according to Common Toxicity Criteria 2.0. MTD was defined when 2 of 6 patients developed DLT. The starting dose of paclitaxel was 20 mg/m2 once weekly, with a subsequent dose escalation of 10 mg/m2 in cohorts of 3 new patients. Radiation therapy was administered in a conventional technique over 7 weeks in 2.0-Gy/daily fractions for 5 days/wk up to total doses of 68-70 Gy. RESULTS: From November 2000 to June 2001, 16 patients completed chemoradiotherapy. On the first-dose level (20 mg/m2), no patient experienced DLT. On the next dose level with 30 mg/m2, 1 patient experienced DLT with grade 3 mucositis, which lasted for 5 weeks, and among the additional 3 patients, no one developed DLT. On the third dose level with 40 mg/m2, 1 patient developed grade 3 mucositis and another grade 3 dermatitis, and both of them lasted more than 3 weeks. To make the trial more credible, another 4 patients were added to the 30-mg/m2 level, and no DLT occurred. Thus, the accrual of patients stopped. CONCLUSION: Combined modality with paclitaxel given weekly, as a 3-hour infusion concomitant to conventional radiotherapy, is feasible for locoregionally advanced NPC. The dose recommended for a phase II trial is 30 mg/m2 with mucositis and dermatitis as DLT, and other toxicity is mild.

Adult↗
PubMed2004

Web-based information retrieval system for the prediction of metabolic pathways.

Analysis of metabolic pathways is a central topic in understanding the relationship between genotype and phenotype. The rapid accumulation of biological data provides the possibility of studying metabolic pathways both at the genomic and metabolic levels. Our motivation is to develop a conceptual framework and computational system that will allow retrieval of metabolic information and prediction of metabolic pathways. In this paper, we introduce a metabolic pathway prediction framework that extracts metabolic information from biological databases via the Internet, and builds metabolic pathways with data sources of genes, sequences, enzymes, metabolites, etc. It provides an easy-to-use interface to retrieve, display, and manipulate metabolic information. The system has been implemented into PathAligner, available at http://bibiserv.techfak.uni-bielefeld. de/pathaligner/.

Computer Simulation↗
PubMed2004

Effect of conjugated equine estrogen in combination with two different progestogens on the risk factors of coronary heart disease in postmenopausal Chinese women in Taiwan: a randomized one-year study.

BACKGROUND: To compare the effect of hormone replacement therapy (HRT) using estrogen plus dydrogesterone or estrogen plus medroxyprogesterone acetate (MPA) on the risk factors for coronary heart disease (CHD) in postmenopausal women. METHODS: A randomized, prospective 1-year clinical trial was designed. All of the postmenopausal women (n = 279) received sequential conjugated equine estrogen (CEE) at a dose of 0.625 mg/day for 25 days (days 1-25) of each month. These women were also randomly assigned to receive either dydrogesterone 10 mg/day (E + D group, n = 140) or MPA 5 mg/day (E + P group, n = 139) for 14 days (days 12-25) of each month. Serum biochemical markers, lipoproteins, plasma prothrombin time (PT), partial prothrombin time (PPT) and antithrombin III-antigen (ATIII-Ag) were analyzed at baseline, and after 6 and 12 months of treatment. RESULTS: Liver function, renal function, PT and PPT did not change significantly during the 12-month trial. The E + D group had a more pronounced increase in high density lipoprotein cholesterol (HDL-C) than the E + P group (10.6% vs. 2.7%) after 12 months of treatment (p < 0.05). Both groups showed reduced concentrations of total cholesterol (T-CHO), low density lipoprotein cholesterol (LDL-C) and ATIII, whereas triglyceride (TG) was increased at the end of the trial (without intergroup difference). CONCLUSIONS: Our study demonstrated a favorable effect on lipoprotein profiles with both hormone replacement therapy regimens. Dydrogesterone appears to be superior to medroxyprogesterone acetate from the perspective of modification of coronary heart disease risk factors.

Antithrombin III↗
PubMed2004

Obesity, emerging risk in China: trend of increasing prevalence of obesity and its association with hypertension and hypercholesterolaemia among the Chinese.

1. The aim of the present study was to investigate the trend of the prevalence of obesity in China and its association with hypertension and hypercholesterolemia. 2. A multicentre cross-sectional study was conducted in Chinese men and women aged 48-56 years between 1985 and 2000. In the report, three study periods were classified as survey 1 (1985), survey 2 (1988-1989) and survey 3 (1997-2000) in order to describe the long-term trend. 3. The results show that: (i) mean body mass index (BMI), prevalence of obesity (BMI > or = 28 kg/m2) and overweight (BMI > or = 25 and < 28 kg/m2) increased significantly from 1985 to 2000 in both sexes (P < 0.001); (ii) similar to the trend for BMI, the prevalence of hypertension and hypercholesterolaemia (total cholesterol (TC) > or = 220 mg/dL) also increased significantly from 1985 to 2000 (P < 0.001); (iii) partial correlation and multiple linear regression analyses indicated that increased BMI was significantly positively correlated with blood pressure and TC and negatively correlated with serum high-density lipoprotein-cholesterol (P < 0.01 or P < 0.001); and (iv) multiple logistics regression analysis models indicated that obese subjects had a 3.9-fold higher risk of being hypertensive (relative risk (RR) 4.9; 95% confidence interval (CI) 3.4-7.3) compared with those subjects who had a BMI less than 25 kg/m2. The corresponding RR (95% CI) of obesity for hypercholesterolaemia was 2.63 (1.57-4.40). 4. In conclusion, the results highlight the epidemic of obesity, an emerging risk in China. Great efforts must be made to alter this unwelcome trend.

Asian People↗
PubMed2004

Serum and lymphocyte levels of heat shock protein 70 in aging: a study in the normal Chinese population.

Heat shock proteins (Hsps) have been reported to play an important role in both physiological and pathological processes. Hsps also may serve as biomarkers for evaluating disease states and exposure to environmental stresses. Whether Hsp levels in serum and lymphocytes are correlated with age and sex is largely unknown. In this study, we analyzed serum Hsp70 (the most abundant mammalian Hsp) levels by using Western dot blot in 327 healthy male donors aged between 15 and 50 years. We also investigated the association between Hsp70 levels and age in lymphocytes of 80 normal individuals aged between 40 and 77 years because various chronic diseases increase after the age of 40 years. Our data showed that serum Hsp70 levels were positively correlated with age in subjects aged between 15 and 30 years (P < 0.05) but negatively correlated with age in subjects aged between 30 and 50 years (P < 0.05). Serum Hsp70 levels were the highest in individuals aged between 25 and 30 years among all age groups. In the lymphocyte study there also was a significant age-related decrease in Hsp70 levels in lymphocytes of individuals older than 40 years. The Hsp70 levels were negatively correlated with age (r = -3.708, P < 0.0001) but not with sex (r = -10.536, P = 0.452). This suggests that both serum and lymphocyte Hsp70 levels are age-related and that these may be linked to age-related stress. Thus, age is an important factor in using serum and lymphocyte Hsp70 as biomarkers to evaluate the disease states or exposure to environmental stresses (or both).

Adolescent↗
PubMed2004

PathAligner: metabolic pathway retrieval and alignment.

MOTIVATION: Analysis of metabolic pathways is a central topic in understanding the relationship between genotype and phenotype. The rapid accumulation of biological data provides the possibility of studying metabolic pathways at both the genomic and the metabolic levels. Retrieving metabolic pathways from current biological data sources, reconstructing metabolic pathways from rudimentary pathway components, and aligning metabolic pathways with each other are major tasks. Our motivation was to develop a conceptual framework and computational system that allows the retrieval of metabolic pathway information and the processing of alignments to reveal the similarities between metabolic pathways. RESULTS: PathAligner extracts metabolic information from biological databases via the Internet and builds metabolic pathways with data sources of genes, sequences, enzymes, metabolites etc. It provides an easy-to-use interface to retrieve, display and manipulate metabolic information. PathAligner also provides an alignment method to compare the similarity between metabolic pathways. AVAILABILITY: PathAligner is available at http://bibiserv.techfak.uni-bielefeld.de/pathaligner.

Algorithms↗
PubMed2004

P-selectin cell adhesion molecule in inflammation, thrombosis, cancer growth and metastasis.

P-selectin (CD62P) is a member of the selectin family of cell adhesion molecules. It is expressed on stimulated endothelial cells and activated platelets and mediates leukocyte rolling on stimulated endothelial cells and heterotypic aggregation of activated platelets onto leukocytes. It also mediates heterotypic aggregation of activated platelets to cancer cells and adhesion of cancer cells to stimulated endothelial cells. Using P-selectin knockout mice, the importance of P-selectin-mediated cell adhesive interactions in the pathogeneses of inflammation, thrombosis, growth and metastasis of cancers has been clearly demonstrated. Here we will summarize the current knowledge and highlight the important progress in the biomedical research of P-selectin biology, providing a suitable target for therapeutic interventions developed through both experimental and bioinformatic approaches.

Animals↗
PubMed2004

[A study on the mutation of P gene region including YMDD motif in hepatitis B virus].

OBJECTIVE: To investigate the primary structure and heterogenenity of P gene region including YMDD motif in hepatitis B virus. METHODS: From serum samples collected from 4 patients who had never been treated with anti-viral drugs, DNA fragments of 1057bp long of P gene were amplified and cloned into pUC19. Twenty positive clones were chosen randomly from each sample. The YMDD motif mutation was detected by mismatched PCR-RFLP. Finally last ten positive clones of two samples were sequenced. RESULTS: Nucleotide mutation rates among clones of Sample 1 and 2 were 0.3% - 1.1%, 0.4% - 1.7%, respectively. Among 80 clones, the variations from YMDD to YMGD were revealed in two clones. CONCLUSION: There are HBV quasispecies in the P gene region including YMDD motif of hepatitis B virus and a novel mutation of YMDD motif in the sera of patients without being therapied by anti-viral drugs.

Adult↗
PubMed2004

[Expression of soluble intercellular adhesion molecule-1 in peri-implant sulcular fluid].

OBJECTIVE: To investigate the expression of soluble intercellular adhesion molecule-1(sICAM-1) in peri-implant sulcular fluid (PISF) of different health conditions. METHODS: According to the health condition and plaque adhesion around dental implant, 51 titanium implants of 30 partly edentulous patients were divided into 3 groups: healthy group(H), gingivalis group(G) and peri-implantitis group(P). The clinical parameters included peri-implant pocket depth(PPD), gingival blood index (GBI), modified plaque index (mPLI) and sICAM-1. We used periopaper strips to collect PISF and an ELISA technique to measure the levels of sICAM-1. RESULTS: The PPD levels of H, G and P groups were (2.64 +/- 1.00) mm, (3.65 +/- 0.60) mm and (4.39 +/- 1.46) mm respectively. The sICAM-1 levels in the three groups were (348.10 +/- 313.27) ng/ml, (898.30 +/- 501.14) ng/ml and (1149.36 +/- 1035.78) ng/ml. The sICAM-1 levels of PISF in the inflammatory groups and plaque adhesion groups were significantly higher than that in the healthy group and non-plaque adhesion group (P < 0.05). The PPD level in inflammatory groups was also significantly higher than that in healthy group. CONCLUSION: Both the patients with peri-implantitis and the healthy controls showed the presence of sICAM-1 in PISF. Plaque accumulation might trigger the up-regulation of sICAM-1 levels, and the onset of inflammation would enhance the up-trend.

Adult↗
PubMed2004

[Investigation of the expression of calcitonin receptor mRNA in human osteoclasts on deciduous teeth].

OBJECTIVE: To investigate the expression of calcitonin receptor mRNA in the osteoclasts of the resorbing deciduous teeth. METHODS: After fixing the collected deciduous teeth, toluidine blue was performed and tartrate-resistant acid phosphatase (TRAP) staining was used to identify the osteoclasts on the resorbing surface of human deciduous teeth and in situ hybridization of calcitonin receptor mRNA to show its existence. RESULTS: There were a number of TRAP positive osteoclasts on the root surface which showed the expression of calcitonin receptor mRNA. CONCLUSION: On the resorbing surface of human deciduous teeth there are osteoclasts that express calcitonin receptor mRNA, so it is feasible to use this kind of osteoclast to test the effect of external factors on the expression of CTR mRNA.

Humans↗
PubMed2004

[Evaluation of telomerase activation in laryngeal mucosa adjacent to carcinoma].

OBJECTIVE: To investigate telomerase activity in laryngeal nonmalignant mucosa adjacent to carcinoma and discuss its effect on extension and recurrence of laryngeal carcinoma. METHOD: Telomerase repeat amplification protocol was used and combined with histological examination. RESULT: The positive percentage of telomerase activation was even higher in laryngeal nonmalignant mucosa distant toward surgically negative margin of carcinoma than in laryngeal carcinomas themselves (P<0.05). CONCLUSION: Telomerase activation occurred probably before the morphologic alteration, which may imply expansion of the cells with potential of malignant transformation.

Adult↗
PubMed2004

[Observation of osteoclasts on the root surface during human deciduous teeth resorption].

OBJECTIVE: To observe osteoclasts on the resorbing surface of human deciduous teeth. METHODS: After fixing the collected deciduous teeth, we prepared the tooth slices without decalcification, treated them with HE and TRAP dyestuff, and observed the osteoclasts under light and scanning electron microscope. RESULTS: There were large quantity of various forms of overlapping and huge osteoclasts with many nuclei and silk-like protuberances on the resorbing surface of deciduous teeth. The multinucleated osteoclasts align on the surface of coarse dentin. CONCLUSION: On the resorbing surface of human deciduous teeth there are large amount of osteoclasts which can be used as a source of studying human osteoclast.

Humans↗
PubMed2004

[Incidence of deep venous thrombosis (DVT) in patients undergoing thoracotomy and changes of hemostasis].

OBJECTIVE: To survey the incidence of deep venous thrombosis (DVT) in high risk patients undergoing thoracotomy and observe the changes of hemostatic activity. METHODS: Fifty-two consecutive patients (ages that ranged from 35 to 79, 34 men and 18 women) with lung or esophagus cancer were enrolled into this prospective trial. The patients included underwent major thoracic surgery from February 2003 to April 2003. Bilateral lower extremity duplex ultrasonography for DVT screening was performed 3-10 days post surgery in all 52 patients and 57 matched clinic normal controls. Venous blood was collected to determine fibrinogen (FIB), D-dimer(D-D), plasminogen activator inhibitor (PAI), antithrombin (AT)i thrombin antithrombin complex (TAT), prothrombin time (PT), international normalized ratio (INR), and activated partial thromboplastin time (APTT) immediately before surgery, the third and tenth days postoperatively. No patient had a prior thromboembotic history. Risk factors for DVT were evaluated. RESULTS: Of the 52 patients, 28 (53.8%) had an acute postoperative DVT detected in the calf. One patient died of suspected pulmonary embolism postoperatively. Plasma levels of FIB and D-D increased significantly up to 7 d after operation. AT level decreased significantly 3 d after operation and returned to normal 7 d latter. TAT increased significantly 3 d post operation and decreased to normal on day 7. PAI level was lowered 3 d after surgery, but increased significantly on day 7 compared with that on day 3. With the addition of risk factors related to thrombosis, the incidence of DVT was increased correspondingly. CONCLUSION: Of the patients undergoing major thoracic surgery,53.8% of them had a postoperative DVT by postoperative screening duplex ultrasound. In Chinese population, incidence of DVT appears to be high without prophylaxis, which is similar to other reports of westerners. These patients had a number of risk factors for the development of DVT, which include older age, overweight, hypertension, diabetes, and history of thromboembolism, etc. Prophylactic measures should be taken against postoperative venous thromboembolism in major thoracic surgery with high risk, including early mobilization, anticoagulant therapy with heparins, and intermittent pneumatic compression (IPC).

Adult↗