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Biomedical subjects

M Xie

Publications and source records attributed to M Xie.

At least 73 records · Page 4Linked to original sources
PubMed1997

[Human rotavirus infection in perinatal transmission].

OBJECTIVE: To investigate the perinatal infection of human rotavirus (HRV) in pregnant women and the effect on their neonates. METHODS: HRV was examined by RT-PCR in cervical secretion and feces of 250 pregnant women and fecal samples of their neonates on the third postpartum day. RESULTS: In pregnant women the HRV prevalence was 26.0% in feces and 8.8% in cervical secration, respectively. The infection rate of the 250 neonates in the first three days after birth was 4.4%, 15.6% and 22.0%, respectively. The HRV infection rate in neonates of infected mothers was 52.31%. CONCLUSION: The infected mothers may be an important source for HRV infection of neonates. HRV transmitted via the labor tract and intrahospital transmission were the main sources for the neonatal infection.

Female↗
PubMed1997

[A preliminary study on p53 gene expression and infection of human papilloma virus in laryngeal squamous cell carcinoma].

Using immunohistochemical techniques with p53 monoclonal antibody DO-7 and polymerase chain reaction with type specific primers, we detected the expression of p53 of laryngeal and hypopharyngeal squamous cell carcinoma (L-HSCC) in 42 patients, tissues around tumor in 25 patients, human papilloma virus (HPV) 16/18 DNA in paraffinembedded carcinoma tissues from 13 patients with laryngeal squamous cell carcinoma (LSCC). The results showed that overexpression of p53 was detected in 54.8% (23/42) of L-GSCC and 20% (5/25) of hyperlasia epithelia, respectively. There was no correlation of p53 overexpression with clinical stages and histological grading of tumors (P > 0.05). HPV16 DNA encoding E6 protein was detected in 23.1% (3/13) LSCC tissues by PCR. The results suggest that overexpression of p53 and HPV infection are not only associated with pathogenesis of this kind of cancer but also cooperated during carcinogenesis.

Aged↗
PubMed1996

[Effects of ding zhi pills on the scopolamine-induced impairment of passive avoidance in rats].

The Ding Zhi Pills described in "Thousand-Golden-Prescriptions" have better memory improving effect than those described in "Prescriptions People's Welfare Pharmacy". A combination of Poria, Radix Polygalae and Rhizoma Acori Graminei could enhance the pharmacologic effect of Radix Ginseng. Cinnabaris, described in "Prescriptions People's welfare Pharmacy", as one of the compositions in Ding Zhi Pills, does not improve the impairment of learning and memory, and therefore seems to have no meaning in the Ding Zhi Pills.

Animals↗
PubMed1995

Streptolysin-O induces release of glycosylphosphatidylinositol-anchored alkaline phosphatase from ROS cells by vesiculation independently of phospholipase action.

Streptolysin-O (SLO), a cholesterol-binding agent, was used for studies on the release of glycosylphosphatidylinositol (GPI)-anchored alkaline phosphatase (AP) from ROS cells. Treatment of cells with SLO resulted in a time- and concentration-dependent release of AP into the extracellular medium. This release was potentiated by Ca2+ and bovine serum, but not by GPI-specific phospholipase D (GPI-PLD) purified from bovine serum. The released AP distributed to the detergent phase after Triton X-114 phase separation. This result suggested that the released AP contained an intact GPI anchor, and thus both proteolysis and anchor degradation by anchor-specific hydrolases, including GPI-PLD, as the potential mechanisms for SLO-mediated AP release were ruled out. The released AP sedimented at 100,000 g. A substantial amount of lipids was detected in the 100,000 g pellet. Cholesterol and sphingomyelin were enriched in SLO-released material, compared with intact cells. These results were consistent with vesiculation as the mechanism for SLO induction of AP release. Two other cholesterol-binding agents, saponin and digitonin, were also able to release AP, possibly by a similar vesiculation mechanism, whereas others, including nystatin, filipin and beta-escin, failed to elicit any AP release. Eight GPI-anchored proteins were identified in ROS cells, and all were substantially enriched in the vesicles released by SLO. Taken together, these results do not provide any support for the hypothesis that the clustering of GPI-anchored proteins in the plasma membrane is responsible for their resistance to GPI-PLD cleavage.

Alkaline Phosphatase↗
PubMed1995

Analysis of linear oligogalacturonic acids by negative-ion electrospray ionization mass spectrometry.

Linear oligogalacturonic acids (1,4-linked alpha-D-galacturonic acid oligomers), obtained by partial acid hydrolysis of orange polygalacturonides, were studied by negative-ion electrospray ionization mass spectrometry, without prior sample derivatization. After preparative separation using high-resolution anion-exchange chromatography, some fractions enriched in uronic acids were desalted, transferred into a methanol+water solution adjusted to pH 10, and directly submitted to electrospray ionization mass spectrometry in the negative-ion recording mode. Clear molecular mass assignments of the oligomers, covering a degree of polymerization between 4 and 7, were obtained.

Carbohydrate Sequence↗
PubMed1995

[Selenium content of tea from different provinces of the People's Republic of China].

In the People's Republic of China there are wide regions where many people suffer from strong selenium deficiency. In order to elucidate the possibilities to compensate this state of need by the national drink, the selenium contents of 31 tea samples from nine provinces of the PR China were determined by hydride generation atomic absorption spectrometry (HG-AAS). The Se contents of the ten analyzed tea samples from one region with soils containing high selenium amounts range from 83 ng/g to 7530 ng/g. These results are in contrast to the Se contents of the remaining tea samples from other regions, which range from 28 to 573 ng/g. The extractable part of selenium in the tea drink ranges between 7% and 27% without significant difference among different tea samples. The accuracy of Se determination was tested by using one tea standard reference material. The daily consumption of one "Se tea" examined in this study assures that people who suffer from a Se deficiency resume enough of it. Drinking normal quantities of this tea an intoxication by Se is not to be expected.

China↗
PubMed1995

Attenuation of hepatic neutrophil sequestration by anti-CINC antibody in endotoxic rats.

Cytokine-induced neutrophil chemoattractant (CINC) is a member of the chemokine alpha sub-family. It is induced in rats by tumor necrosis factor-alpha (TNF-alpha), interleukin-1, and lipopolysaccharide and is implicated in neutrophil infiltration in response to inflammatory stimuli. We tested the hypothesis that pretreatment with anti-CINC antibody or by cobra venom factor attenuates hepatic neutrophil accumulation induced by a 90 min infusion of Escherichia coli endotoxin. Changes in the expression of CD11b/c and CD18 and in plasma TNF-alpha levels were also investigated. Cultured hepatocytes and Kupffer cells of endotoxic rats produced significantly more CINC than those of saline-infused controls. CINC generation by Kupffer cells was much lower than generation by hepatocytes. Pretreatment with anti-CINC antibody or cobra venom factor significantly reduced hepatic neutrophil sequestration, but did not affect the up-regulation of CD11b/c and CD18 expression on liver-sequestered neutrophils or plasma TNF-alpha levels. We conclude that CINC-mediated hepatic neutrophil accumulation may not be necessarily associated with up-regulation of neutrophil adhesion molecules or elevated circulating TNF-alpha levels. Attenuation of hepatic neutrophil sequestration by anti-CINC antibody is likely based on blocking of the chemotactic activity of CINC and thus diminishing the chemotactic gradient established in the liver.

Animals↗
PubMed1995

[Effects of bio-mineral food additive on health].

Spartina alterniflora, one kind of bio-mineral food additive and special nutrient liquid, rich in bioactive materials, was extracted from a marsh plant grown in beach. It can enhance immune function of animals and human bodies, increase the tolerance to hypoxia in rats, prolong life span of fruit flies, and increase activity of human serum superoxide dismutase.

Adjuvants, Immunologic↗
PubMed1995

[Clinical research of compound salviae miltiorrhizae injection for severe pancreatitis].

Compound salviae miltiorrhizae injection was administered after operation for 28 cases of severe pancreatitis, and 13 cases were taken as a control group. The results showed that: (1) the difference was not obvious in the morbidity of complications between the two groups, but the mortality (3.6%) of the trial group was significantly lower than that (30.8%) of the control group (P < 0.05); (2) Hematocrit was clearly decreased from 46.1 +/- 5.2% to 33.2 +/- 3.9% in the trial one (P < 0.05), but platelet and hemoglobin showed no statistical significance. It is concluded that compound salviae miltiorrhiza injection might improve hemorheologic abnormalities of the disease, promote the recovery of the pancreatic tissue, and correct the serious complications such as adult respiratory distress syndrome etc.

Adult↗
PubMed1994

Expression and secretion of glycosylphosphatidylinositol-specific phospholipase D by myeloid cell lines.

Glycosylphosphatidylinositol (GPI)-specific phospholipase D (GPI-PLD) is abundant in mammalian plasma. It could potentially regulate the surface expression of GPI-anchored proteins, but it remains to be established which tissue(s) or cell type(s) are the principal sources of the circulating enzyme. Here we report that all the myeloid cell lines tested, including K562 (multipotential blast), KG-1 (human myeloblast), HL-60, NB4, PLB-985 (human promyelocyte), U937 (human promonocyte), THP-1 (human monocyte) and J774, RAW264.7 (mouse monocyte/macrophage), contained GPI-degrading activity. T.l.c. analysis of reaction products confirmed the activity as a phospholipase D. These cells also exhibited positive immunofluorescent staining with an anti-GPI-PLD monoclonal antibody. The expression of GPI-PLD activity was not substantially reduced when the cells were cultured in either serum-free medium or GPI-PLD-depleted regular medium. Both granulocytic and monocytic differentiation of myelomonoblastic lines (e.g. HL-60) induced by dimethyl sulphoxide or phorbol diester respectively was accompanied by a 2-3-fold increase in GPI-PLD activity. J774 and HL-60 cells secreted GPI-PLD into the medium constitutively. Taken together, these data suggest that myeloid cells are a potential contributor to the circulating GPI-PLD pool. As leucocytes express many important GPI-anchored surface antigens, these cells may prove to be a valuable model system for studying the physiological functions of GPI-PLD.

Animals↗
PubMed1994

Identification and characterization of an ecto-(lyso)phosphatidic acid phosphatase in PAM212 keratinocytes.

Intact PAM212 keratinocytes were found to preferentially degrade exogenous phosphatidic acids (PA) containing short fatty acid chains. The product of this degradation was inorganic phosphate (Pi), suggesting that the enzyme was a phosphatase. Systematic studies using enzymatically synthesized PA and lysophosphatidic acid (lysoPA) demonstrated that the sn-2 fatty acid chain length was the determining factor for suitability of PA as substrate for this cell-associated enzyme. Thus 1-acyl-2-lyso-PA provided the best substrate for this enzyme while long-chain PA were poor substrates. The enzyme was effectively inhibited by NaF and Na3VO4, but was insensitive to inhibitors of alkaline phosphatase or other nonspecific phosphatases. The enzyme activity was solubilized from intact cells by proteinases, such as trypsin and papain, and the reaction product Pi was distributed exclusively in the extracellular medium, suggesting that this (lyso)PA phosphatase is an ectoenzyme. These results unequivocally demonstrated the presence of a (lyso)PA phosphatase located at the cell surface. This novel ectoenzyme may provide a mechanism for the inactivation of the potent bioactive phospholipid, lysoPA.

Animals↗
PubMed1994

Solvent isotope effects and the nature of electrophilic catalysis in the action of the lactate dehydrogenase of Bacillus stearothermophilus.

Deuterium oxide at atom fractions of deuterium from 0.0 to 0.97 has an effect of less than 20% on the kinetic term kcat/KmB (believed to reflect the transition state for the hydride-transfer step) for the reduction of pyruvic acid by NADH at 55 degrees C, with catalysis by the tetrameric form of the lactate dehydrogenase of Bacillus stearothermophilus. This observation suggests that the hydride-transfer event is not assisted by protonic bridging to the carbonyl group being reduced. The results are consistent with protonic bridging only if an opposing isotope effect is present, for example from a generalized conformation or solvation change. The results are consistent with other forms of electrophilic catalysis.

Deuterium Oxide↗
PubMed1994

Optimization of the contact damping and stiffness coefficients to minimize human body vibration.

In this paper, a lumped mass human model is used to minimize the energy absorption at the feet/hip level when the body is subjected to vertical vibration. The contact forces are assumed unknown. By coupling the dynamic response of the body with certain objective criteria, the optimum damping and stiffness coefficients of shoes/chairs are sought. The optimization technique is based on the quasi-Newton and finite-difference gradient method and is used to seek optimum coefficients of the contact forces in the solution of the body's response in the frequency domain. The criteria of acceleration, displacement and internal forces response area swept for a range of 0-15 Hz form the basis of our simulation study. In the seated/standing postures it is found that for each criteria the frequency response shifts the peak of resonance of each body segment response from 4.5/3.67 Hz to 2.5/2.255 Hz. In addition, the total energy reduces drastically when the contact conditions are optimum. The method presented in this paper is useful in modeling the medium of contacts and especially in controlling the effects of human body vibration.

Compliance↗
PubMed1994

Hepatic neutrophil sequestration in early sepsis: enhanced expression of adhesion molecules and phagocytic activity.

Abdominal sepsis was produced by cecal ligation and puncture (CLP) in rats to observe neutrophil (PMN) migration into the liver and assess the functional alteration in circulating PMNs, liver sequestered PMNs, and Kupffer cells. 7 h following CLP, rats demonstrated severe leukopenia and major amount of PMNs sequestered into the liver (17.0 +/- 5.5 x 10(6) vs. 3.1 +/- 1.6 x 10(6) in sham-operated rats, p < .01). Light microscopic evidence demonstrated the presence of such PMNs in the sinusoids and in the liver parenchyma. By 20 h following CLP, the number of PMNs in the liver was not different from sham controls. CD11b/c expression on circulating PMNs was significantly upregulated from 1.6 +/- .3 to 7.8 +/- .9 mean channel fluorescence (MCF) in 7 h CLP rats. Liver-sequestered PMNs showed further enhancement of CD11b/c expression to 10.4 +/- 1.9 MCF than the circulating PMNs. However, in the late septic rats, CD11b/c expression on circulating PMNs 2.9 +/- .5 MCF returned to the control level of 1.9 +/- .7 MCF. Liver-sequestered PMNs and Kupffer cells in septic rats exhibited remarkably enhanced phagocytic activities 53.0 +/- 10.8 and 56.9 +/- 7.7% phagocytosis, respectively, regardless of the suppression of phagocytosis in circulating PMNs (16.0 +/- 5% phagocytosis). In 7 h CLP rats, liver-sequestered PMNs exhibited a significantly higher level of superoxide anion generation 21.8 +/- 12.2 nmol/30 min/10(6) cells than did Kupffer cells (4.2 +/- 3.0 nmol/30 min/10(6) cells). These results demonstrate that the liver is a target organ for neutrophil sequestration during the septic response.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

[A measurement of liver volume and its changes in post-hepatitic cirrhosis].

By use of the computerized digital image processing system, the liver volume in vivo was successfully measured and the three dimensional image of the liver rebuilt in 62 cases of posthepatitic cirrhosis and 15 noncirrhotics. It was found (1) The liver volume of 474.64 +/- 115.28cm3/m2 in Chinese cirrhotics is significantly smaller than that of the control (P < 0.001); (2) In most cases, patients in class I of the liver function have a larger liver volume; (3) Patients with smaller liver volume have poor tolerance to surgery with a critical value of 400cm3/m2; (4) the liver volume considerably reduced after shunt plus devascularization but did not change after devascularization only.

Anthropometry↗
PubMed1994

Strain complex of Schistosoma japonicum in the mainland of China.

The present paper deals with studies on the characteristics of Schistosoma japonicum isolated from five localities in the mainland of China. The following items were observed and compared including morphometric data, susceptibility of six mammalian hosts, prepatent period, compatibility between larvae and snail hosts, size of hepatic granuloma produced by eggs, immunoreactions in experimental animals, sensitivity to praziquantel, SDS-PAGE protein pattern and its antigenicity analysis, DNA hybridization and genetic variation and differentiation by analysis with multilocus enzyme electrophoresis. By means of these multidisciplinary methods, from morphological to molecular level, the following conclusions may be drawn from our results. The evidence indicates firstly that S. japonicum in the mainland of China comprises a strain complex with several components of geographically distributed strains. At least four distinct strains exist, ie Yunnan, Guangxi, Sichuan and Anhui-Hubei. Characteristics of each strain are distinct and the results of these studies lead to discussion on the problem of the intraspecific and interstrain differentiation of S. japonicum in the mainland of China.

Animals↗
PubMed1993

Phospholipase D activity in phagocytic leucocytes is synergistically regulated by G-protein- and tyrosine kinase-based mechanisms.

The regulation of phospholipase D (PLD)-type effector enzymes by G-proteins and protein kinases/phosphatases was characterized in the U937 human promonocytic leucocyte line. PLD activity was assayed by measuring (in the presence of 1% ethanol) the accumulation of phosphatidylethanol in cells permeabilized with beta-escin, a saponin-like detergent. Basal PLD activity was very low when cells were permeabilized and incubated in cytosol-like medium containing micromolar [Ca2+]. When this medium was supplemented with exogenous MgATP or guanosine 5'-[gamma-thio]triphosphate (GTP[S]), PLD activity increased by 9- and 14-fold respectively. Cells permeabilized in the absence of exogenously added MgATP, but in the presence of 1 microM vanadate/100 microM H2O2, also exhibited a modest 12-fold increase in PLD activity. However, the simultaneous presence of either GTP[S] plus exogenous MgATP or GTP[S] plus vanadate/H2O2 (and endogenous MgATP) induced similar 60-75-fold increases in the rate and extent of phosphatidylethanol accumulation. These latter effects of vanadate/H2O2 were strongly correlated with the very rapid accumulation of multiple tyrosine-phosphorylated proteins. Other studies utilized cells which were permeabilized in the presence of GTP[S] and then washed before assay of PLD. These cells retained approximately 60% of the MgATP-regulatable PLD activity (EC50 approximately = to 100 microM MgATP) observed in freshly permeabilized non-washed cells. In the absence of GTP[S] pre-treatment, washed cells retained minimal PLD activity. Genistein, a tyrosine kinase inhibitor, significantly attenuated the ability of MgATP to stimulate PLD activity and accumulation of tyrosine-phosphorylated proteins in the washed GTP[S]-treated cells. These data suggest that PLD activity in myeloid leucocytes involves co-ordinate regulation by both G-protein(s) and tyrosine phosphorylation.

Adenosine Triphosphate↗