Biomedical subjects

Gang Hu

Publications and source records attributed to Gang Hu.

At least 91 records · Page 5Linked to original sources

PubMed2004

Ocular vaccinia following exposure to a smallpox vaccinee.

PURPOSE: To describe the presentation and management of the first identified case of ocular vaccinia infection associated with the current smallpox vaccination program. DESIGN: Case report. METHODS: Vaccinia virus was isolated by cell culture of a conjunctival swab. Direct staining with fluorescein isothiocyanate-labeled vaccinia antibody and polymerase chain reaction testing confirmed the diagnosis. RESULTS: In February 2003, a 26-year-old woman developed right preseptal cellulitis and blepharoconjunctivitis following contact with a vaccinated member of the military. The preseptal cellulitis resolved with antibacterial therapy, and the conjunctival infection was treated successfully with a 14-day course of topical trifluridine and a single dose of intravenous vaccinia immune globulin. CONCLUSIONS: To facilitate rapid diagnosis and appropriate treatment, clinicians must maintain a high index of suspicion for ocular smallpox vaccine-associated adverse reactions in vaccine recipients and their close contacts.

Adult↗

PubMed2004

Effects of impaired fasting glucose and impaired glucose tolerance on predicting incident type 2 diabetes in a Chinese population with high post-prandial glucose.

AIMS: To ascertain which impaired glucose homeostasis at baseline is predictive of conversion to type 2 diabetes in both men and women in a high-risk non-diabetic population. METHODS: The screening survey for type 2 diabetes was conducted in 1994, and a follow-up study of 627 high-risk non-diabetic individuals at baseline was carried out in 1999 in Beijing area. A total of 70 men and 76 women developed diabetes during the 5-year follow-up. RESULTS: After adjustment for age, body mass index, smoking, systolic blood pressure, family history of diabetes, total cholesterol, triglycerides, antihypertensive medication, occupation, education, urine albumin excretion rate, and fasting insulin, the odds ratios for incidence of diabetes were 1.00, 2.04 (95% CI 0.84-4.97), 7.82 (2.66-23.00), 9.38 (3.30-26.69) in men with normal glucose, isolated IFG, isolated IGT, and both IFG and IGT, respectively. In women, the corresponding odds ratios were 1.00, 2.19 (0.91-5.30), 1.62 (0.72-3.67), and 8.79 (2.98-25.93), respectively. CONCLUSIONS: This study shows that combined IFG and IGT at baseline is a strong risk predictor for the development of diabetes in both men and women. Isolated IGT is also a predictor of diabetes in Chinese men.

Asian People↗

PubMed2004

Low physical activity as a predictor for total and cardiovascular disease mortality in middle-aged men and women in Finland.

AIMS: To investigate separately for men and women whether moderate or high leisure time physical activity, occupational physical activity, and commuting activity are associated with a reduced cardiovascular disease (CVD) and all-cause mortality, independent of CVD risk factors and other forms of physical activity. METHODS AND RESULTS: Prospective follow-up of 15,853 men and 16,824 women aged 30-59 years living in eastern and south-western Finland (median follow-up time 20 years). CVD and all-cause mortality were lower (9-21%) in men and women (2-17%) who were moderately or highly physically active during leisure time. Moderate and high levels of occupational physical activity decreased CVD and all-cause mortality by 21-27% in both sexes. Women spending daily 15 min or more in walking or cycling to and from work had a reduced CVD and all-cause mortality before adjustment for occupational and leisure time physical activity. Commuting activity was not associated with CVD or all-cause mortality in men. CONCLUSION: Moderate and high levels of leisure time and occupational physical activity are associated with a reduced CVD and all-cause mortality among both sexes. Promoting already moderate levels of leisure time and occupational physical activity are essential to prevent premature CVD and all-cause mortality.

Adult↗

PubMed2004

Joint effects of physical activity, body mass index, waist circumference and waist-to-hip ratio with the risk of cardiovascular disease among middle-aged Finnish men and women.

AIMS: To assess joint associations of physical activity and different indicators of obesity (body mass index, waist circumference, and waist-to-hip ratio) with the risk of cardiovascular disease (CVD). METHODS AND RESULTS: The study comprised 18,892 Finnish men and women aged 25-74 years without history of coronary heart disease, stroke, or heart failure at baseline. Physical activity, different indicators of obesity, education, smoking, blood pressure, total and high-density lipoprotein cholesterol and history of diabetes were measured at baseline. An incident CVD event was defined as the first stroke or coronary heart disease event or CVD death based on national hospital discharge and mortality register data. The median follow-up time was 9.8 years. Physical activity had a strong, independent, and inverse association with CVD risk in both genders. All obesity indicators had a significant direct association with CVD risk after adjustment for age, smoking, education and physical activity. Further adjustment for the obesity-related risk factors weakened the associations and they remained statistically significant in men only. Physical activity and the obesity indicators both predicted CVD risk in men, but in women the joint effect was inconsistent. CONCLUSION: Both regular physical activity and normal weight can reduce the risk of CVD. Physical inactivity seems to have an independent effect on CVD risk, whereas obesity increases the risk partly through the modification of other risk factors.

Adult↗

PubMed2004

A new spatiotemporally chaotic cryptosystem and its security and performance analyses.

A one-way-coupled chaotic map lattice is proposed for cryptography of self-synchronizing stream cipher. The system performs basic floating-point analytical computation on real numbers, incorporating auxiliarily with few simple algebraic operations on integer numbers. Parallel encryption (decryption) operations of multiple chaotic sites are conducted. It is observed that the system has high practical security, fast encryption (decryption) speed with software realization, and excellent reliability against strong channel noise, and its overall cryptographic properties are considerably better than both known chaotic cryptosystems and currently used conventional cryptosystems, including the advanced encryption standard.

Models, Statistical↗

PubMed2004

The metabolic syndrome defined by factor analysis and incident type 2 diabetes in a chinese population with high postprandial glucose.

OBJECTIVE: The aim of this study was to examine how the major components of the metabolic syndrome relate to each other and to the development of diabetes using factor analysis. RESEARCH DESIGN AND METHODS: The screening survey for type 2 diabetes was conducted in 1994, and a follow-up study of nondiabetic individuals at baseline was carried out in 1999 in the Beijing area. Among 934 nondiabetic and 305 diabetic subjects at baseline, factor analysis was performed using the principle components analysis with varimax orthogonal rotation of continuously distributed variables considered to represent the components of the metabolic syndrome. Fasting insulin was used as a marker for insulin resistance. Of the 559 subjects without diabetes at baseline, 129 developed diabetes during the 5-year follow-up. Factors identified at baseline were used as independent variables in univariate and multivariate logistic regression models to determine risk factor clusters predicting the development of diabetes. RESULTS: Four factors were identified in nondiabetic and diabetic subjects. Fasting insulin levels, BMI, and waist-to-hip ratio were associated with one factor. Systolic and diastolic blood pressures were associated with the second factor. Two-hour postload plasma glucose (2-h PG) and serum insulin and fasting plasma glucose were associated with the third factor. Serum total cholesterol and triglycerides were associated with the fourth factor. The first and the third factors predicted the development of diabetes. In diabetic patients at baseline, the combination of systolic and diastolic blood pressure was the most important factor, and urinary albumin excretion rate clustered with fasting and 2-h PG levels. CONCLUSIONS: Insulin resistance alone does not underlie all features of the metabolic syndrome. Different physiological processes associated with various components of the metabolic syndrome contain unique information about diabetes risk. Microalbunuria is more likely to be a complication of type 2 diabetes or hypertension than a marker for the metabolic syndrome.

Adult↗

PubMed2004

Inhibitory effects of 1-methyl-4-phenylpyridinium on glutamate uptake into cultured C6 glioma cells.

AIM: To investigate the effect of 1-methyl-4-phenylpyridinium (MPP+) on the glutamate uptake into cultured C6 glioma cells. METHODS: The glutamate uptake into C6 glioma cells was measured by radio-ligand binding assay method. The effect of MPP+ on the morphology of C6 glioma cells was observed under phase contrast microscopy; apoptosis of C6 glioma cells were measured by FITC-labeled Annexin V staining and flow cytometry. Cell viability was measured by MTT method. RESULTS: MPP+ inhibited glutamate uptake into C6 glioma cells. However, MPP+ failed to induce any morphological changes of C6 glioma cells, and exposure to MPP+ had no effect on the viability and the apoptotic percentage of C6 glioma cells. Incubation with 12-O-tetradecanoylphorbol -13-acetate (TPA), a protein kinase C activator, caused a significant increase in glutamate uptake and completely reversed MPP+-induced inhibitory effect on glutamate uptake. CONCLUSION: The present results indicate that glutamate transporters may have important pathogenetic implications in Parkinson disease. MPP(+)-induced inhibition of glutamate uptake was due to the dysfunction of glutamate transporters; TPA enhanced glutamate uptake and completely reversed the inhibitory effect of MPP+.

1-Methyl-4-phenylpyridinium↗

PubMed2004

Protective effects of nicotine against glutamate-induced neurotoxicity in PC12 cells.

This study aimed to assess whether nicotine prevented glutamate neurotoxicity in PC12 cells, and to identify the molecular mechanisms of any effects. The results showed that glutamate neurotoxicity in PC12 cells could be prevented by treatment with nicotine at concentrations of 10 nmol x l(-1) - 1 mmol x l(-1). This effect was in turn found to be inhibited by the application of the nicotinic acetylcholine receptor (nAChR) antagonist mecamylamine. Nicotine significantly decreased the basal level of intracellular free Ca(+2) and enhanced the buffering action on Ca(+2) overload induced by high concentrations of glutamate (5 mmol x l(-1)). In addition, nicotine treatment up-regulated the mRNA and protein expression of apoptosis-related factors including bcl-2 mRNA and protein, but down-regulated the expression of bax mRNA and protein. It is concluded that the protective effects of nicotine against the neurotoxicity induced by glutamate are mediated by nAChRs, due to the increased buffering action on Ca(+2)and the modulation of apoptotic processes.

Animals↗

PubMed2004

Proteomic response analysis of endothelial cells of human coronary artery to stimulation with carbachol.

AIM: To identify the molecular basis of the endothelial target for acetylcholine (ETA). METHODS: Proteomic methods were used to monitor changes in protein expression in the first 10 h following the stimulation of human coronary endothelial cells with carbachol 100 micromol/L. Thirty proteins showing the largest changes were identified by mass spectrometry. RESULTS: Based on analysis with Image Master 2-D Elite software, about 623 protein spots were detected in control cells and 825 protein spots in carbachol-treated cells, the matching rate was 68.1 %. Among all the detected spots, 39 were up-regulated and 29 were down-regulated, showing detectable changes varied from 1.7-3.8 folds. Forty one spots in the peptide mass fingerprints were successfully obtained. The most interesting feature was that all the four newly synthesized proteins belonged to the heat shock protein family. CONCLUSION: These identified proteins played key roles in the molecular mechanism of ETA.

Acetylcholine↗

PubMed2004

[Effects of iptakalim on the proliferation of cultured rabbit pulmonary arterial smooth muscle cells induced by endothelin-1].

OBJECTIVE: To explore the effects of iptakalim on the proliferation of rabbit pulmonary arterial smooth muscle cell(PASMC) induced by endothelin-1(ET-1) in vitro. METHODS: The experimental models of proliferation of rabbit PASMC induced by ET-1 in vitro were established and [(3)H]-thymidine ([(3)H]-TdR) incorporation and flow cytometric analysis(FCA) were used. RESULTS: The value of [(3)H]-TdR incorporation in ET-1 group was increased 1.468 times higher than that in control group. Iptakalim at the concentrations of 10(-7) mol/L, 10(-6) mol/L, 10(-5) mol/L lowered [(3)H]-TdR incorporation by (19.8 +/- 4.6)%,(41.2 +/- 9.5)%, (54.7 +/- 10.1)%, declined the total of the DNA synthesis (S) and the mitotic phase (G(2)/M) ratios by (36.6 +/- 5.7)%, (42.6 +/- 4.9)%, (66.3 +/- 4.7)%, and increased the static phase (G(0)/G(1)) ratio by (14.4 +/- 3.0)%, (17.9 +/- 2.6)%, (27.9 +/- 3.2)%, respectively, compared with the value of the cells treated with ET-1 only (P < 0.01). Glibenclimide abolished the effect of iptakalim on [(3)H]-TdR incorporation. CONCLUSION: Iptakalim has an inhibitory effect on PASMC proliferation induced by ET-1 through activating ATP sensitive potassium (K(ATP)) channels.

ATP-Binding Cassette Transporters↗

PubMed2004

[Fetal ECG monitoring system based on MCU processing].

In order to monitor the fetus in labor, the signal characteristic from fetal scalp electrode is researched, An adaptation algorithm and a peak to peak detecting technology are adopted in signal processing, and an adaptation gain control method is used to eliminate disturber from base-line shift. A fetal ECG monitoring system is designed on the basis of C8051F020 MCU.

Adult↗

PubMed2004

[Iptakalim enhances astrocytic glutamate uptake activity].

AIM: To investigate the effect of iptakalim (Ipt), a novel ATP-sensitive potassium channel opener (KATPCO), on astrocyte glutamate uptake activity. The mechanism of action involved was also examined. METHODS: Primary cultures of astrocytes were prepared from cerebral cortexes of 1 to 2 days old Sprague-Dawley rats. Cultures were preincubated with iptakalim of various concentrations with the absence or presence of 6-hydroxydopamine (6-OHDA, 50 micromol x L(-1)). Then, the cells were treated with pinacidil (10 micromol x L(-1), K+ channel opener) instead of iptakalim and pretreated with glibenclamide (20 micromol x L(-1), ATP-sensitive K+ channel inhibitor) before pinacidil or iptakalim was added into the medium so that the mechanism of action of iptakalim could be analysed. Astrocyte glutamate uptake activity was determined by intracellular concentration of 3H labeled D,L-glutamate, using isotope techniques. RESULTS: Both iptakalim and pinacidil were shown to increase glutamate uptake activity of astrocytes and reverse inhibitory effect induced by 6-OHDA. But the increased and reversed effects of iptakalim or pinacidil on astrocytic glutamate uptake were found to be completely antagonized by glibenclamide. CONCLUSION: These data indicated that iptakalim can enhance astrocytic glutamate uptake activity due to its K+ channel opening properties and lessen glutamate excitotoxicity. Iptakalim may be useful for the therapy of Parkinson's disease.

Animals↗

PubMed2003

Relationship of physical activity and body mass index to the risk of hypertension: a prospective study in Finland.

Prospective studies on physical activity in relation to the risk for hypertension are scant, particularly in women. This study aimed at finding out whether regular physical activity can reduce the risk of hypertension in both men and women, and in subjects with and without overweight. We prospectively followed 8302 Finnish men and 9139 women aged 25 to 64 years without a history of antihypertensive drug use, coronary heart disease, stroke, and heart failure at baseline. Both single and joint associations of physical activity and body mass index with the risk of hypertension were examined using Cox proportional hazard models. During a mean followup of 11 years, there were 1600 incident cases of drug-treated hypertension. Multivariate-adjusted hazards ratios of hypertension associated with light, moderate, and high physical activity were 1.00, 0.63, and 0.59 in men (Ptrend<0.001), and 1.00, 0.82, and 0.71 in women (Ptrend=0.005), respectively. This association persisted both in subjects who were overweight and in those who were not. Multivariate-adjusted hazards ratios of hypertension based at different levels of body mass index (<25, 25 to 29.9, and > or =30) were 1.00, 1.18, and 1.66 for men (Ptrend<0.001), and 1.00, 1.24, and 1.32 for women (Ptrend=0.007), respectively. Further adjustment for baseline systolic blood pressure did not affect the protective effect associated with physical activity, but it weakened markedly the association between body mass index and hypertension. The present study indicates that regular physical activity and weight control can reduce the risk of hypertension. The protective effect of physical activity was observed in both sexes regardless of the level of obesity.

Adult↗

PubMed2003

A unilateral 6-hydroxydopamine lesion decreases the expression of metabotropic glutamate receptors in rat substantia nigra.

Loss of dopaminergic neurons in the substantia nigra pars compacta (SNc) in Parkinson's disease (PD) leads to augmentation of glutamatergic activity in the subthalamic nucleus (STN). Moreover, antagonizing excitotoxicity has yielded mostly symptomatic improvements in experimental animals of PD. Therefore, we used immunocytochemistry to examine the effect of unilateral 6-hydroxydopamine lesions of SNc on the expression of metabotropic glutamate receptors (mGluR1a, 2/3, 5, 4, 8) and tyrosine hydroxylase (TH). 6-Hydroxydopamine causes a fall in the number of mGluRs and TH in the lesioned lateral substantia nigra. Pharmacological activation of group II or III mGluRs or blockade of group I mGluRs for 1 week significantly increased the expression of the same group receptors. The alteration in the receptor expression may be a compensatory mechanism developed after mGluRs ligands neuroprotective treatment.

Animals↗

PubMed2003

Suppression of spiral waves and spatiotemporal chaos by generating target waves in excitable media.

A method for suppressing spiral waves and spatiotemporal chaos in excitable media is proposed. Applying suitable periodic force to a single point, we can successfully suppress spiral waves as well as spatiotemporal chaos by generating target waves. After we turn off the external force, target waves finally disappear and the whole system which was in the state of spiral wave or spatiotemporal chaos goes to the spatially homogeneous steady state. It is shown that our control method is not sensitively model dependent. It works for a model for catalytic CO oxidation on platinum as well as for a model for cardiac muscle.

Journal Article↗

PubMed2003

Analytical solution of space probability distributions of particles in a one-dimensional ring.

Spatial probability distributions of a few particles having nonidentical masses in one-dimensional space with both periodic and fixed boundary conditions are analytically computed in statistical equilibrium states, and explicit solutions of the probability distributions are obtained. Some nontrivial interesting features of the probability distributions are predicted and fully confirmed by numerical simulations. The realization of a microcanonical equilibrium state of the system is justified by the agreement between the theoretical predictions and numerical observations.

Journal Article↗

PubMed2003

Determination of dissociation constants of anthrocycline by capillary zone electrophoresis with amperometric detection.

Although daunorubicin, pharmorubicin and idarubicin are important drugs in medical and in pharmaceutical research, the dissociation constants (K(a)) of these substances are frequently not known. A method based on a non-linear model enabling the efficient determination of the K(a) of the three drugs by capillary zone electrophoresis with amperometric detection (CZE-AD) has been demonstrated. The pK(a) values obtained through the method were in agreement with the values by typical spectrophotometric method.

Antibiotics, Antineoplastic↗

PubMed2003

Physical activity during leisure and commuting in Tianjin, China.

OBJECTIVE: To investigate physical activity during leisure time and commuting among persons aged 15-69 years in the urban population of Tianjin, China, and to assess its associations with demographic and health-related characteristics. METHODS: In 1996 a cross-sectional survey of 2002 males and 1974 females provided information on physical activity during leisure time and commuting and on demographics and health behaviours. FINDINGS: No leisure-time physical activity was engaged in by 67% of females and 61% of males. However, only 4% of females and 9% of males reported an absence of physical activity during commuting. The mean duration of leisure-time physical activity for the whole population was about 10 min per day. The average commuting time on foot or by bicycle was about 30 min. Leisure-time physical activity was more frequent among highly educated people, people with high incomes, white-collar workers, married people, non-smokers, or people commuting on foot or by bicycle than among other people. Persons with low incomes, male blue-collar workers and married people were more likely than others to engage in 30 min or more per day of physical activity on foot or by bicycle when commuting. CONCLUSION: People in Tianjin engaged in a high level of physical activity when commuting and a low level of leisure-time physical activity.

Adolescent↗