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Biomedical subjects

J Ma

Publications and source records attributed to J Ma.

At least 145 records · Page 8Linked to original sources
PubMed2001

[A case-control study of risk factors for type 2 diabetes mellitus].

OBJECTIVE: The prevalence of type 2 diabetes mellitus is increasing so to investigate the relation between insulin resistance and development of type 2 diabetes mellitus. METHODS: A 1:1 pair-matched case-control study was conducted with diagnostic criteria recommended by WHO. Controls matched with cases by age, sex, race and resident place. Information on demographic, history of disease, life-style were obtained through questionnaire. Variables including fasting blood glucose (FBG), fasting blood insulin (FBI), total cholesterol (TC), triglyceride (TG), waist-to-hip ratio (WHR), waist-to-thigh ratio (WTR) were measured for every subject. Conditional logistics regression was used for data analysis. RESULTS: The results showed that insulin resistance, history of hypertension and waist-to-hip ratio were associated with type 2 diabetes mellitus. The values of OR were 1.530 (95% CI: 1.234-1.896), 4.833 (95% CI: 1.966-11.703), 21.996 (95% CI: 5.461-88.593), respectively. CONCLUSION: Insulin resistance was risk factor causing type 2 diabetes mellitus, independent of other risk factors.

Case-Control Studies↗
PubMed2001

[Study of the association between human papillomavirus infection and cervical cancer in Xianguan county, Shanxi province].

OBJECTIVE: To investigate human papillomavirus (HPV) prevalence in the high incidence areas of cervical cancer in Shanxi and to study the association between HPV infection and cervical cancer. METHODS: Cells exfoliated from cervix (collected by clinician) and from vagina (collected by subject herself) of 1997 women aged 35-45 from Xiangyuan county, Shanxi province were analyzed blindly by Hybrid Capture Assay (HC-II), which could detect 13 HPV types of high-risk. Unconditional logistics regression model was used to analyze the relation between HPV and cervical cancer/cervical intraepithelial neoplasia (CIN). Kappa coefficient was used to compare the agreement of the two tests. RESULTS: HPV DNA detection rate in the population was 20.8% while HPV infection rates increased with the seriousness of cervical lesions (chi 2 = 444.04, P = 0.000). Rates of the two groups (35-39 and 40-45) had no significant difference (20.9%: 20.6%, chi 2 = 0.03, P = 0.86). Unconditional logistic regression analysis showed, when comparing with the normal subjects, the risk odds ratio of HPV infection with cervical cancer/high grade CIN and low grade CIN were 254.2 and 26.4 respectively, with attributable risk proportions (ARP) 98.1% and 83.6% respectively. The sensitivity of self-collected vaginal swabs assayed for HPV DNA was lower than that of clinician-collected cervical samples assayed for HPV DNA (84%: 98%, chi 2 = 5.92, P = 0.015). No significant difference in specificity was seen between them (86%: 85%, chi 2 = 0.00, P = 0.997) and there was fair agreement between the two tests (kappa = 0.74). CONCLUSION: High-risk HPV infection in female genital tract was the major risk factor of cervical cancer and CIN in the areas. Prevention and control of cervical cancer should be focused on avoiding HPV infection, screening women for HPV infection and monitoring population infected by high-risk HPV. Self-collected vaginal swabs assayed for HPV DNA seemed a more practical method in primary screening for cervical cancer.

Adult↗
PubMed2001

Low incidence of severe aGVHD and accelerating hemopoietic reconstitution in allo-BMT using lenograstim stimulated BM cells.

OBJECTIVES: To investigate the efficacy of accelerating hemopoietic reconstraction and reducing a graft versus host disease (GVHD) in Allo-BMT receiving lenograstim stimulated donor marrow and to assess the preliminary biological mechanism. METHODS: The donors for thirty patients (study group) with leukemia were given lenograstim 3-4 micrograms.kg-1.d-1 for seven days prior to marrow harvest. The results of subsequent engraftment in the recipients was compared with fifteen donors without G-CSF (control group). Five donors themselves were studied to assess the effects of lenograstion on hematopoietic progenitor cells and lymphocyte subsets in BM. RESULTS: The stimulated bone marrow contained a higher number of nucleated cells, CFU-GM and CD34+ cells (P < 0.01). The hematopoetic reconstitution was accelerated. Until granulocyte counts exceeded 0.5 x 10(9)/L and plalete counts exceeded 20 x 10(9)/L, the days were 16.7 +/- 3.2 and 18.4 +/- 3.0 days as compared with those of the control group (22.5 +/- 5.1 and 26.3 +/- 5.9 days respectively, P < 0.01). The incidence of grade II-IV aGVHD was very low, only one case with grade II aGVHD on the skin in the study group. Four out of fifteen patients (26.7%) in the control group had grade II-IV aGVHD (P < 0.05). The number of T lymphocyte subsets in the harvested BM stimulated by G-CSF changed. In comparison with the control group, CD4+ decreased and CD8+ increased significantly (P < 0.01). The changes of progenitor cells and T lymphocyte subsets in BM from pre- to post-G-CSF stimulation indicated that the percentage of CD4+ cells reduced (P < 0.05), that of CD8+ cells, and that of CD34+ increased (P < 0.01). The incidence of chronic GVHD and relapse of leukemia were not different significantly between both groups. CONCLUSIONS: Allogenic bone marrow transplant (Allo-BMT) donors given G-CSF can accelerate engraftment and minimize the incidence of severe aGVHD. There is a trend in favour of improved transplant-related complications.

Acute Disease↗
PubMed2001

[A field evaluation of the epidemiological efficacy of an attenuated live hepatitis A vaccine (H2 strain)].

OBJECTIVE: To evaluate the epidemiological efficacy of an attenuated live hepatitis A vaccine (H2 strain). METHODS: A randomized and controlled field trial was carried out in part of Zhengding County and the Jiaoqu District of Shijiazhuang city. There were about 37,000 children in these areas involved in the study and they were randomly divided into a vaccine group and a control group according to the months they were born. Children in the vaccine group were given a dose of 10(6.5) TCID50/ml attenuated live hepatitis A vaccine while those in the control group were given nothing. As soon as the children in the vaccine group had been vaccinated, all the subjects were carefully followed up for hepatitis A cases. RESULTS: In the 3.5 years of follow-up, there were 20 hepatitis A cases in the control group and the incidence rate was 136.4 per 100,000 population. There was only one hepatitis A case in the vaccine group and the incidence rate was 8.1 per 100,000 population. The difference of the incidence rates between the two groups was highly significant (P < 0.001) and the protective efficacy of the vaccine was 94.4% (95% CI: 67.1%-100%). CONCLUSION: The protective efficacy of the vaccine was excellent and the vaccine is suitable to be widely used.

Child↗
PubMed2001

[Counter-effect of intermittent +Gz exposures on vasoreactivity in decline in hind body arteries of rats under simulated weightlessness].

Objective. To investigate the counter-effect of intermittent artificial gravity, the present study examined vasoreactivity changes of femoral and mesenteric arteries in rats subjected to simulated weightlessness plus standing or centrifugation. Method. Forty male Sprague-Dawley rats were divided into simultaneous control (CON), simulated weightlessness (SUS), simulated weightlessness plus 1 h standing (STD1), simulated weightlessness plus 1.5 G centrifugation (1.5 G), and simulated weightlessness plus 2.6 G centrifugation (2.6 G) groups. Responses of arteries to vasoconstrictor were examined in vitro using isolated femoral and mesenteric arterial rings. Result. The contractile responsiveness to KCl or PE of femoral and mesenteric arterial rings isolated from SUS significantly decreased as compared with CON. And those of STD1 and the two centrifuged groups significantly enhanced as compared with that of SUS. Whereas there was no difference among STD1, 1.5 G, 2.6 G and CON. Conclusion. Simulated weightlessness may result in decreased contractile responses to KCl and PE of rat femoral and mesenteric arteries. Both STD1, 1.5 G, and 2.6 G prevented the decrease of contractile response to KCl and PE of femoral arteries.

Animals↗
PubMed2001

[A novel Fe/AC desulphurizer at low temperature].

Activated coke was used to support Fe2O3(Fe/AC) for flue gas SO2 removal. Reaction conditions on DeSOx activity were investigated. The results show that Fe/AC had higher activity than AC or Fe2O3 at temperature of 120 degrees C-250 degrees C. H2SO4 and Fe2(SO4)3 were formed after Fe/AC sorbed SO2, H2O and O2 increased the amount of SO2 adsorption. Fe/AC derived from AC of higher BET surface area had higher DeSOx activity. Fe/AC was suitable to be used at GHSV below 800 L/(kg.h).

Air Movements↗
PubMed2001

[Immunogenicity and long-term persistence of anti-HAV in groups with different attenuated and inactived hepatitis A vaccine dosage].

OBJECTIVE: This study was carried out to assess the long-term persistence of antibodies against hepatitis A in different vaccine dosage groups. METHODS: One hundred and sixty-six susceptibles aged form 6 to 8 years old were selected in Zhengding county, and were divided into 4 different dose groups. Each group received 10(6.17)TCID(50), 10(6.52)TCID(50), 10(6.83)TCID(50) of attenuated hepatitis A vaccine or 10(6.83)TCID(50) of the same vaccine but treated with 60 degrees C for 3 hours. All subjects were bled at month 3, 12, 24, 36 and 48. All serum specimens were tested for antibodies to HAV using Abbott-IMx mEIA reagent. Part of the tested negative serum specimens were retested by neutralization assay for 10(6.52)TCID(50) and 10(6.83)TCID(50) dosage groups at 4 years after vaccination. RESULTS: The seroconversion rate and GMT 3 months after vaccination in each dosage group showed a significant dose-response relationship. Antibody levels reached the peak at month 3 in each group but declined dramatically within one year and the decline slowed down thereafter. The serocoversion rate and GMT in 10(6.83)TCID(50) dose group 4 years after vaccination was significant higher than those of other dosage groups. Positive rates of neutralizing antibodies in B and C dosage group were 60.0% and 83.3% respectively. CONCLUSION: The immunogenicity and long-term persistence were related to the attenuated hepatitis A vaccine titer. The vaccine, whose titer was 10(6.83)TCID(50), had good immunogenicity and long-term persistence. Booster dose was not needed within short time after initial vaccination.

Child↗
PubMed2001

[The characteristics of multifocal electroretinogram in normal subjects in China].

OBJECTIVE: To test the characteristics of multifocal ERG in normal Chinese subjects and to provide reference values in clinical application. METHODS: The multifocal ERGs by using VERIS 4.0 visual evoked response imaging system were tested for 42 subjects (48 eyes). Their ages ranged from 11 to 67 years (mean, 40.7 years). The stimulative visual angles subtended plus minus 26.6 horizontally and plus minus 22.1 vertically. Burian-Allen contact lens electrode was used to record the responses from 103 retinal locations in 8 min (16 segments). RESULTS: With age increasing, the latencies of N(1) wave and P(1) wave delayed, there were statistically significant differences of the latencies between < 50 year group and greater-than-or-equal 50 year group (t > 2.01, P < 0.05), and the amplitude densifies of N(1) wave and P(1) wave decreased with wide inter-individual variation. The amplitude densities of N(1) wave and P(1) wave were greatest at the central fovea, they were (44.88 plus minus 13.30) nV/deg(2), (70.90 plus minus 17.77) nV/deg(2) respectively, the densities reducing towards more peripheral location. The amplitude sum of N(1) wave at the upper retina were greater than that at the lower retina, and the amplitude densities and sums of N(1) wave and P(1) wave at superior-temporal quadrant were greater than that at inferior-nasal quadrant. CONCLUSION: Our results suggest multifocal ERG be able to reflect the visual function at different retinal locations correctly and objectively and provide normal reference limits.

Adolescent↗
PubMed2001

[Safety and immunogenicity of a new inactivated hepatitis A vaccine].

BACKGROUND: To evaluate the safety and immunogenicity of a new inactivated hepatitis A virus (HAV) vaccine. METHODS: In a randomized controlled trail thirty-one HAV-seronegative adults were enrolled and randomly assigned to either study group or control group. Subjects in the study group were given 1000 units of the new inactivated HAV vaccine, with a booster at 3 months. Subjects in the control group were given 720 ELISA units Havrix, produced by SmithKline Beecham Biologicals, with a subsequent dose at 3 months. Local and systematic reactions and serum response to the vaccines were compared between the two groups. RESULTS: Mild local reactions were noted in one subject from the study group and two from the control group after primary vaccination. Mild systematic reactions were reported in two subjects from each group after primary vaccination and in one subject from the study group after booster vaccination. Seroconversion rates were 94%, 100%, and 100% in the study group at 1, 3, and 4 (1 month after booster) month, respectively. The corresponding figures were 73%, 80% and 100% in the control group. Geometric mean antibody titers were 139.2 mIU/ml, 137.7 mIU/ml, and 1 066.7 mIU/ml at 1, 3, and 4 months,respectively, in the study group,and 104.3 mIU/ml, 111.3 mIU/ml, and 760.7 mIU/ml in the control group. CONCLUSIONS: The new inactivated hepatitis A vaccine was safe and highly immunogenic.

Adolescent↗
PubMed2001

[A computer-aid study on the craniofacial features of Archang race in Yunnan province of China].

OBJECTIVE: Archang race is one of special minoritis in Yunnan province of China. However, there is not former report about overall craniofacial features in Archang race, therefore a computerized measurement on craniofacial features of Archang race was established in this study. METHODS: On the basis of the principles of random sampling, the craniofacial features of 196 normal adults of Archang race coming from Longchuan County, Dehong Dai Jingpo nationality autonomous prefecture in Yunnan province of China were investigated using the craniofacial video-computerized measurement system which was developed by us. RESULTS: Totally 41 measured items and 17 indexes of craniofacial features were obtained from male and female adults of Archang race. On the basis of 5 indexes, the people were classified according to the head, facial, and nose forms. CONCLUSION: The results of this study are of great importance in terms of that the reference is not only significant for anthropology, ethnology, but also for medicine and industry.

Aged↗
PubMed2001

[Determination of rutin and quercetin in mulberry leaves by high performance capillary electrophoresis].

Rutin and quercetin are the main effective components of mulberry leaves with the functions of controlling the increase of fat in serum and controlling the formation of arterio-sclerosis. In this article a high performance capillary electrophoretic(HPCE) method was used to separate and determine rutin and quercetin in mulberry leaves collected from different periods, different places and different kinds in Xinjiang. Electrophoretic conditions were as follows: a capillary tube (75 microns i.d. x 57 cm (effective length, 50 cm)), with 10 mmol/L dihydrogen sodium phosphate-20 mmol/L sodium borate containing 15% methanol as the running buffer (pH 8.62) and an applied voltage of 20 kV, at 25 degrees C, detected at a wavelength of 245 nm. Under the optimum conditions, rutin and querctin were separated successfully from other components within 12 minutes. The corrected peak areas of rutin and quercetin increased linearly with the increase of their concentrations in the range of 4.4 mg/L-28.8 mg/L and 1.8 mg/L-145.8 mg/L respectively. The corresponding regression equations for rutin and quercetin were Y = 71.60 rho + 30.51 (r = 0.9991) and Y = 315.17 rho - 929.70 (r = 0.9949) respectively, and the recoveries were 95.64% and 99.36%. The analytical results demonstrate the method is simple, quick and well reproducible, and can be used as a reliable tool for the quality control of mulberry leaves.

Drugs, Chinese Herbal↗
PubMed2001

[Peripheral effector mechanism hypothesis on cardiovascular dysfunction after spaceflight].

In the years of 1990's, we systematically studied the adaptational changes in structure and function of both the heart and the vessels during simulated weightlessness. In our serial work, the tail-suspension rat model was used to simulate the microgravity-induced cephalad shift and redistribution of blood. On the basis of the facts we observed and the more recent advances in space and ground-based studies in 1990's, we put forward a hypothesis to offer a possible explanation for the frequent occurrence of postflight cardiovascular dysfunction. It states that, in addition to the factor of hypovolemia, the microgravity-induced adaptational changes in the structure and function of the two main effectors of the cardiovascular system, i.e., the arterial smooth muscle and the cardiac muscle might be one of the most important mechanisms accounting for postflight cardiovascular dysfunction.

Cardiovascular System↗
PubMed2001

[Mitochondrial permeability transition pore regulates the apoptosis in MGC-803 induced by the extract of glycyrrhiza uralensis Fisch].

In our previous studies, we have discovered that the extract of glycyrrhiza uralensis Fisch (EGUF) can induce obvious apoptosis in gastric cancer cell Line MGC-803. Here, further investigation was carried on about the time-lapse changes of mitochondria transmembrane potential, intracellular free calcium ions, DNA electrophoresis, plasma membrane permeability and chromatin condensation during the apoptotic process of MGC-803 induced by EGUF and the influences of MPT-specific inhibitor Cyclosporin A(CsA) on these changes. Enhancement of plasma membrane permeability with PI staining, increase of intracellular free calcium ion and decrease of mitochondria transmembrane potential are early events in apoptotic cascades, prior to the appearances of apoptotic peak, chromatin condensation and DNA ladder. CsA significantly inhibited enhancement of plasma membrane permeability, change of intracellular free calcium ions and decrease of mitochondria transmembrane potential, also greatly delayed the progress of apoptosis. Thus, our results suggest that calcium and CsA-sensitive MPT is involved in the apoptosis of MGC-803 induced by EGUF.

Apoptosis↗
PubMed2001

The electroretinogram in patients with retinal vascular occlusion.

PURPOSE: To measure and analyze the electroretinogram (ERG) in patients with retinal vascular occlusion. METHOD: Fifty-eight cases (59 eyes) of retinal vascular occlusion and the fellow eyes of 47 cases were tested with Ganzfeld ERG. The scotopic and photopic ERG, and oscillatory potentials were tested according to the ERG standard of ISCEV. RESULTS: The abnormal rates of OPs and b wave were higher in retinal vascular occlusion. The abnormal ERG appeared mostly in CRVO among four types of retinal vascular occlusion. The comparisons of some amplitudes and latencies between the fellow eyes and the affected eyes showed statistically significant difference. CONCLUSION: The oscillatory potentials and b waves have important roles in evaluating the retinal function of patients with retinal vascular occlusions. There are some clinical significance for comparing ERG between the affected eye and the fellow eye.

Adolescent↗
PubMed2001

[The development of computerized cardiac programmable stimulator].

This paper introduces a fully computerized cardiac programmable stimulator. With the visual interface of computer, the configuration and control of stimulation will be realized conveniently. Meanwhile, the current status and the waves during stimulation will be displayed in window real-time, which improved the visualization and availability in medical application. It has been proved that this system is simpler in operation and more functional than traditional cardiac programmable stimulators, and therefore it is valuable in medical applications.

Electric Stimulation↗
PubMed2001

[The development of body posturography device using inclinometer technique].

A kind of body posturography device using inclinometer technique is described in this paper. Comparing with a device using gravimeter technique it shows following advantages: 1) As the signal of body sway angle is obtained by the incline-sensor, it is easy to test subject's balance function on the multifarious body supporters; 2) When the platform of the global bottom is used, the subject may come into contact with ground at one point, so as to weaken significantly subject's somatosensory of moving center of gravity.

Algorithms↗
PubMed2001

[Differentiation and malignant suppression induced by mouse erythroid differentiation and denucleation factor on mouse erythroleukemia cells].

OBJECTIVE: To investigate the roles of mouse erythroid differentiation and denucleation factor (MEDDF), newly cloned in our laboratory, in erythroid terminal differentiation. METHODS: Mouse erythroleukemia cells (MEL) were transfected with eukaryotic expression plasmid pcDNA-MEDDF. The changes of cell growth rate, mitotic index and colony-forming rate in semi-solid medium were investigated. The expressions of c-myc and beta-globin genes were analysed by semi-quantitative RT-PCR. RESULTS: MEL cells transfected with pcDNA-MEDDF showed significant lower growth rate, mitotic index, and colony-forming rate in semisolid medium(P < 0.01). The percentage of benzidine-positive cells was 32.8% after transfection. The expression of beta-globin in cells transfected with pcDNA-MEDDF was 3.43 times higher than that of control (MEL transfected with blank vector, pcDNA3.1), and the expression of c-myc was decreased by 66.3%. CONCLUSIONS: MEDDF can induce differentiation of MEL cell, and suppress its malignancy likely.

Activins↗