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Biomedical subjects

Y Zeng

Publications and source records attributed to Y Zeng.

At least 127 records · Page 7Linked to original sources
PubMed1998

[Quantitative analysis of motor unit potential in patients with dermatomyositic disease].

To diagnose dermatomyositic disease well, we adopted the method of EMG in an investigation of 37 patients. Their electrophysiologic parameters of 220 muscles were determined. The results showed that the parameters, including the average DUR, AMP, RISE, AREA, AR/AM and SI of motor unit potentials (MUPs) were significantly lower than those of the controls (P < 0.05 or P < 0.01), especially AREA and SI (P < 0.01). But no remarkable difference was found between the muscles on the two sides of the diseased extremties. These findings suggest that quantitative analysis of MUPs is of importance to diagnosis of dermatomyositic disease and the parameters such as AREA and SI may provide more valuable information.

Action Potentials↗
PubMed1998

[Clinical study on qingning oral liquid in treating senile chronic obstructive pulmonary disease with pulmonary hypertension].

OBJECTIVE: To evaluate the clinical effect of Qingning Oral Liquid (QNOL) in treating senile chronic obstructive pulmonary disease (COPD) with pulmonary hypertension. METHODS: Forty patients with mean pulmonary artery pressure (mPAP) more than 2.67 kPa (by impedance rheogram) were divided randomly into two groups. Twenty cases of QNOL group treated by conventional therapy with QNOL cases ml three times a day for 30 days and the other 20 cases treated with conventional therapy alone were taken as control group. Impedance cardiogram and pheopneumogram, blood gas analysis, mean systemic arterial pressure (mSAP), plasma tissue plasminogen activator(tpA) and plasminogen a ctivator inhibitor (PAI) activity were examined before and after treatment. RESULTS: After treatment, the mPAP of QNOL group lowered for 23.80 +/- 2.31%, the cardiac output, stroke volume and cardiac index of patients were improved, tPA activity elevated and PAI activity decreased. As compared with before treatment and the control group, these changes were significant statistically. The mSAP, PaO2 and PaCO2 were not significantly changed after treatment (P > 0.05). The change of mPAP showed negatively correlated with tPA activity (r = -0.554) and positively correlated with PAI activity (r = 0.608, P < 0.05). CONCLUSIONS: QNOL has a selective effect on pulmonary hypertension, its mechanism might be correlated to the elevating plasma tPA and the lowering of PAI activity.

Aged↗
PubMed1998

Effects of simulated weightlessness and gamma-irradiation on myocardial cells and osteoblasts.

The effects of simulated weightlessness and gamma-irradiation on the structure and function of the myocardial cells and osteoblasts were investigated with a rotating clinostat and 2 Gy 60Co gamma-irradiation. The results showed: (1) Under the simulated weightlessness (SWL), the diameter of the myocardial cells decreased 40%. And the long-short diameter proportion decreased 70%, (P < 0.01); SWL affected the cell skeleton and the distribution of microfilament became ununiform, the orientation was unclear; SWL had significant effects on osteoblast disintegration and proliferation. The disintegration function decreased and the proliferation process was inhibited; (2) 2 Gy 60Co gamma-ray irradiation had significant effects on Lactate Dehydrogenase (LDH) activity and Superoxide Dismutase (SOD), Malonaldehyde (MDA) content in the myocardial cells, (P < 0.05) (5) A synergistic effect was observed between irradiation and SWL.

Animals↗
PubMed1998

[Clinical studies on the dental and occlusal conditions of molars with vertical cracking of the root].

OBJECTIVE: To study the contributing factors inducing vertical cracking of the root of molars. METHODS: The dental, periodontal, and occlusal conditions of molars with vertical root cracking were studied in 34 cases (39 teeth). RESULTS: The age range of patients was 40-60 years. The crackings occurred mostly at mesial or mesio-buccal roots, their periodontal conditions were much more worse than those roots without cracking and manifested by deep pocket. The abrasion of the occlusal surfaces was more severe than those molars with no cracking, their contact areas were unstable and deviated buccallly. The direction of force during chewing was therefore horizontal, viz., mesio-distally and bucco-lingually. CONCLUSION: The vertical root cracking of molars is associated with traumatical occlusal contact due to severe abrasion which increases the loading during chewing.

Adult↗
PubMed1998

[Establishment and primary study of an assay for the detection of EB virus specific cytotoxic T lymphocytes].

In our study, a non-radioactive cytotoxicity assay by using a Balb/C (H-2d) mice, P815(H-2d) cells and lactate dehydrogenase (LDH) system was established, in order to detect EB virus specific cytotoxic T lymphocytes(CTLs). In this study, we detected both the changes of primary CTLs and secondary stimulated CTLs. Spleen CTL activity assay showed that the levels of primary and secondary CTLs in recombinant EBV-LMP1 vaccinia virus group were more higher than that in control group, at the same time, obvious enhancement of EBV-LMP1 specific CTL activity was observed in experimental group immunized by Baculovirus system expressing EBV-LMP1 protein when compared with the normal mice group. This work proved that the LDH assay can be used to detect cytotoxic T lymphocytes.

Animals↗
PubMed1998

[Study on the relationship between provenance, leaf type and quality in Magnolia officinalis].

An analysis of effective ingredients in 20 to 29 year old Magnolia officinalis of three different leaf types coming from various sources shows that the content of phenols differ extremely significantly in various leaf types which are a key to determination of quality of Magnolia officinalis also varies significantly among different sources which only have a significant effect on the content of magnolol. Varieties and types cultivated in different places are responsible for the variation in content of magnolol. The conclusions obtained from this study coincide with the traditional insight into quality of Magnolia officinalis.

Biphenyl Compounds↗
PubMed1998

[The expression of human leukocyte antigen from peripheral blood of patients with herpetic keratitis].

PURPOSE: To understand the correlation between the expression of human leukocyte antigen from peripheral blood and herpetic keratitis so as to find the pathogenesis of HSK. METHODS: The expression of HLA-ABC, HLA-DR, HLA-DP, HLA-DQ from peripheral blood of 32 cases with herpes simplex keratitis (the stromatic and ulcer herpetic keratitis are 16 cases respectively), comparing with the normal people, were investigated by flow cytometry. RESULTS: The expression rate of HLA-ABC from peripheral blood of patients with herpetic keratitis (both the stromatic and ulcer groups) was lower, and the expression of HLA-DR and HLA-DP was higher than normal people. No difference was found between the stromatic and the ulcer herpetic keratitis in the expression of HLA-ABC, HLA-DR, HLA-DP, HLA-DQ. CONCLUSION: The immune model in patients with herpetic keratitis is different from normal people. The individual with this kind of immune model can not destroy the infected virus effectively, also show autoimmunization to cornea.

Adult↗
PubMed1997

A major DNA binding protein encoded by BALF2 open reading frame of Epstein-Barr virus (EBV) forms a complex with other EBV DNA-binding proteins: DNAase, EA-D, and DNA polymerase.

A major 135-kDa DNA binding protein (mDBP) encoded by the BALF2 open reading frame of Epstein-Barr Virus (EBV) is known to be an essential protein for the induction of the lytic cycle. The present investigation was carried out to know whether this protein forms a complex in vivo with other viral DNA binding proteins (DBP) involved in DNA replication: DNA polymerase, EA-D (diffused early antigen), and DNAase. Immunoprecipitation assays followed by mono- and two-dimensional electrophoresis showed that mDBP forms a complex with these three DBP. Other complexes were also found such as EA-D/DNAase, DNA polymerase/DNAase, and DNA polymerase/EA-D. The complexed forms already exist in the early stage of EBV cycle before DNA synthesis is induced in the EBV producer P3HR-1 cell line. The exonuclease activity encoded by DNAase was found to be inhibited when this enzyme complexed with mDBP, while the EBV DNA polymerase retained its activity in the complexed form with mDBP. Our results suggest that these complexes already present before DNA synthesis are necessary for EBV DNA synthesis.

Antigens, Viral↗
PubMed1997

Purification and specificity of beta1,2-xylosyltransferase, an enzyme that contributes to the allergenicity of some plant proteins.

The enzyme that transfers D-xylose from UDP-xylose to the beta-linked mannose of plant N-linked oligosaccharides was purified about 51,000-fold to apparent homogeneity from soybean microsomes. On SDS gels, two proteins of 56 and 59 kDa were detected and both were labeled to the same extent by the photoaffinity label, 5-N3-UDP-[32P]xylose. Labeling of both proteins was inhibited by cold UDP-xylose, but not by UDP-glucose. The amount of 5-N3-UDP-[32P]xylose that bound to the two protein bands was greatly increased in the presence of oligosaccharide acceptors. The best acceptor for xylose transfer and for stimulation of UDP-xylose binding was GlcNAc2Man3GlcNAc2-T, but GlcNAc1Man3GlcNAc2, with the GlcNAc on the 3-branch, was also a good acceptor and a good stimulator. A number of other N-linked oligosaccharides were poor acceptors, especially those with galactose units at the nonreducing termini. Many of the properties of this enzyme have been described, and the product of the reaction of UDP-xylose and GlcNAc2Man3(GlcNAc)2 was characterized as GlcNAcbeta1, 2Manalpha1, 6(GlcNAcbeta1,2Manalpha1,3)(Xylbeta1,2)Manbeta1, 4GlcNA c2-T by chemical and NMR methods.

Allergens↗
PubMed1997

Epstein-Barr virus in synergy with tumor-promoter-induced malignant transformation of immortalized human epithelial cells.

It is difficult to study how Epstein-Barr virus (EBV) causes transformation of human epithelial cells. The major difficulty is that cultured human epithelial cells do not express EBV receptor (complement receptor 2, CR2), hence EBV cannot infect such epithelial cells directly. In order to investigate the role of EBV in the transformation of human epithelial cells, pSG-CR2-Hyg carrier was transfected into immortalized human epithelial cells (293 cells) to express EBV receptor. EBV could infect these CR2-positive cells directly, and expressed EBV antigens. EBV-infected epithelial cells grew in piles with multiple cellular layers and lost contact inhibition in vitro. In soft-agar culture containing 12-0-tetradecanoylphorbol 13-acetate (TPA), EBV-infected 293 cells formed more and larger colonies. When EBV-infected 293 cells were transplanted subcutaneously into nude mice, and treated with TPA, poorly differentiated carcinoma was induced. These results suggest that EBV could induce the malignant transformation of immortalized human epithelial cells in synergy with TPA.

Animals↗
PubMed1997

Migration in the urban-rural hierarchy of China: insights from the microdata of the 1987 National Survey.

Microdata from the 1987 National Population Survey are used to analyze internal migration in China in the 1980s. The focus is on the impact of migration policies on rural-urban migration. "There are two main findings. First, although the migration policy resulted in a very low migration level and systematic distortions in migration schedules, its encouragement of downward migrations was very ineffective, whereas its control on rural-to-urban migrations was partially weakened by the strong upward aspirations of rural families awakened by recent economic reform. Consequently, net in-migration contributed substantially to the growth both of city and of town populations. Second, although the level of education had a strong positive effect on the migration propensities both of males and of females in general, it had a strong negative effect on the migration propensities of females at the time of marriage, a finding which suggests that the families at subsistence income level tended to marry their daughters to grooms in other communities in order to reduce the risk of familial income shortfalls."

Asia↗
PubMed1997

A multi-dimensional model for projecting family households--with an illustrative numerical application.

"This paper develops a multi-dimensional model for projecting households and population. The model is constructed to ensure consistency between the demographic events occurring to males and females as well as to parents and children. The model permits projection of characteristics of households, their members, and population structure, using data that are usually available from conventional sources. Unlike the traditional headship-rate method, our model can closely link the projected households with demographic rates. The model includes both nuclear and three-generation households, so that it can be used for countries where nuclear households are dominant and for countries where nuclear and three-generation households are both important. The illustrative application to China, although brief, provides some policy-relevant information about future trends of Chinese household size, structure, and the age and sex distribution of the population, with a focus on the elderly."

Age Distribution↗
PubMed1997

Homonojirimycin and N-methyl-homonojirimycin inhibit N-linked oligosaccharide processing.

Homonojirimycin (HNJ) and N-methylhomonojirimycin (MHNJ) were tested as inhibitors of the purified glycoprotein processing enzymes, glucosidase I and glucosidase II. MHNJ was a reasonably good inhibitor of glucosidase I (Ki = 1 x 10(-6) M) and was about three times as effective on this enzyme as was HNJ. On the other hand, HNJ inhibited glucosidase II with a Ki of about 1 x 10(-6) M, whereas MHNJ was three times less effective (Ki = 3 x 10(-5) M). However, the butyl derivative of HNJ had very low activity toward these two processing glucosidases. HNJ and its methyl derivative were also tested in vivo using influenza virus-infected MDCK cells, and measuring the inhibition of N-linked oligosaccharide processing of the viral envelope glycoproteins. With 100 micrograms/ml of MHNJ in the medium, essentially all of the N-linked oligosaccharide chains of the virus were of the "high-mannose" type with the major structure being characterized as Glc3Man9(GlcNAc)2. Similar results were obtained with HNJ although this compound was less effective in vivo as well as in vitro. These results are in keeping with these inhibitors being effective at the glucosidase I step. Both inhibitors were also tested in MDCK cell cultures to determine whether they affected the in vivo synthesis of proteins, or of lipid-linked saccharides. In contrast to deoxynojirimycin, which has been reported to inhibit the formation of lipid-linked saccharides, no effects were seen on either the incorporation of mannose into lipid-linked saccharides or the incorporation of leucine into protein.

1-Deoxynojirimycin↗
PubMed1997

[Significance of p16 and C-myc expression in the laryngeal squamous cell carcinoma].

OBJECTIVE: To study the clinical significance of p16 and C-myc expression in the laryngeal squamous cell carcinoma (LSCC). METHOD: Immunohisto-chemical detection of p16 proteins and C-myc proteins, in 47 cases of LSCC and 6 cases of normal tissues from the larynx, were conducted in paraffin-embeded sections. RESULTS: No staining was found in 6 cases of normal tissue; The positive expression of p16 and C-myc proteins expression rates did not correlate with sex, age and position of the tumors (P > 0.05); but related to the staging and grade of LSCC (P < 0.05). The expression of C-myc proteins were higher in the case with lymph nodal metastasis than that without lymph nodal metastasis (P < 0.05). CONCLUSION: The expression of p16 and C-myc protein may play an important role in the development of LSCC, and may be a new indicator to assess the prognosis of LSCC.

Adult↗
PubMed1997

[Effects of simulated weightlessness and overweight on the growth of osteoblast cultured in vitro].

A special rotator designed for this experiment was used to simulate the gravitational conditions. 3 groups of osteoblast cells were cultured under simulated hypogravity, normal (1 g) or hypergravity acceleratively (3 g) for 7 d. Changes of cell shape and speed of cell division were observed. The results showed that cells cultured under simulated hypogravity became round and cells divided slowly as compared with 1g group. While cells cultured under 3 g divided more actively and many growth spots appeared in the culture bottle.

Biophysical Phenomena↗
PubMed1997

Changes in the divorce rate and age distribution in China since the 1980s.

"The divorce rate in China during the 1980s was much higher than before for a number of reasons. In order to understand this phenomenon, the authors will make a comparison between the divorce rates, and the age and duration of the marriage at the time of divorce in the early 1980s and in the late 1980s and early 1990s."

Asia↗
PubMed1997

[Serological survey of human T lymphotropic virus type I (HTLV-1) IgG antibody in south region of Xinjiang].

Human T lymphotropic virus type-1 (HTLV-1) is endemic in southwestern Japan, Seychelles Islands, Caribbean basin, Brazil, and Sub Saharan Africa. Recently, the prevalence of HTLV-1 of domestic source has been reported from Beijing, Fujian and so forth. The object of our study is to know whether the prevalence of HTLV-1 is present in Xinjiang. We collected 2642 serm samples of various ages and different nationalities (Uigur, Han and Khalkhas) from south region of Xinjiang and tested for determination of HTLV-1 IgG antibody by IFA. The results showed that the total positive rate of HTLV-1 IgG was 0.34% (9/2642), of which Uigur nationality was 0.74% (8/1082), Khalkhas nationality was 0.21 (1/471), Han nationality was zero (0/1089). This data indicated that there are HTLV-1 infection among the population of Xinjiang and especially in Uigur and Khalkhas. Why did the minority nationalities have relatively high frequency of HTLV-1 infection? This needs to be studied further.

Adolescent↗