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Biomedical subjects

G L Xu

Publications and source records attributed to G L Xu.

33 records · Page 2Linked to original sources
PubMed1991

[Investigation of human cytomegalovirus infection in 103 cases with history of abnormal pregnancy].

Human cytomegalovirus (HCMV)-IgG, IgM antibodies were detected by indirect ELISA in 103 serum specimens from women with history of abnormal pregnancy. The results showed that the positive rates of HCMV-IgG and IgM of abnormal pregnant women were 90.29% and 13.59% respectively. The positive rate of HCMV-IgM in abnormal pregnancies was higher than that of normal pregnancies (4.07%, P less than 0.001). This suggested that the probability of abnormal pregnancy in HCMV-IgM positive women was higher than the negative ones. Thus detecting HCMV-IgM by ELISA could be used not only in early diagnosis of active HCMV infection in pregnant women, but also a way to prevent this delivery of malformed babies.

Adult↗
PubMed1990

Lumbar facet joint capsule: appearance at MR imaging and CT.

The joint spaces and synovium of the lumbar facet joints extend beyond the articular surfaces of the joint in the majority of adults. The authors correlated magnetic resonance (MR) imaging, computed tomographic (CT), and axial cryomicrotome sections of 66 facet joints in nine cadavers. Extensions of the synovium and joint space along the superior and inferior articular processes, under the ligamentum flavum, and into the ligamentum flavum could be recognized with use of MR and, less successfully, CT. The injection of a paramagnetic contrast medium into the facet joint facilitated visualization of the capsule on MR images. On the ventral aspect of the lumbar facet joint, MR images showed regions of high signal intensity where the joint space extended into the ligamentum flavum or between the ligamentum flavum and lamina. On the dorsal aspect of the joint, MR demonstrated prominence of the fibrous joint capsule where the joint space extended under it along the inferior articular process or along the superior articular process. The variable appearance of the ventral and dorsal aspects of the lumbar facet joint on CT and MR images is due to extension of the synovium and joint space.

Adult↗
PubMed1990

Effects of selenium on RNA synthesis and content in rat pancreas.

In order to investigate the effect of selenium supplementation on RNA in the rat pancreas, the rate of in vitro incorporation of [3H]uridine into RNA by pancreas slices derived from two groups of rats fed either a low-selenium diet or a diet supplemented with 0.25 mg/kg selenium as selenite was examined. The RNA and lipid peroxide contents and glutathione peroxidase activity in homogenates from the pancreas were also determined. After feeding for 12-14 weeks, the rates of [3H]uridine incorporation were significantly higher in the pancreatic tissue from the selenium-supplemented diet group. Concomitantly, an increase in glutathione peroxidase activities and RNA content, and a reduction of lipid peroxides, were also found in the pancreatic tissue of the selenium-supplemented group. The results suggest that selenium supplementation at a level of 0.25 mg/kg selenium could promote RNA synthesis with an increase in glutathione peroxidase activity and a decrease of lipid peroxides.

Animals↗
PubMed1989

Continuous fermentation with yeast (Shizosaccharomyces pombe) floccules for ethanol production.

This paper describes an experimental study of continuous fermentation of saccharified starch solution to produce ethanol with yeast particles of a highly flocculent strain of Schizosaccharomyces pombe, which were treated as immobilized microbial cells. Observations were initially made on yeast floccule characteristics during fermentation. An aeration-type fluidized-bed bioreactor that retained virtually all the yeast particles was built and operated continuously for 3 months. Bioreactor operation was found to be quite favorable for this fermentation system. The yeast concentration exceeded 40 g (dry mass)/liter; delivery of a limited amount of supplementary oxygen enhanced throughput to give levels as high as 20-24 g/liter.hr. The kinetic equations were also determined.

Ethanol↗
PubMed1989

CT diagnosis of lacunae.

Lacuna, a special small infarction in deep regions of the brain, is difficult to diagnose clinically. Of 182 stroke patients receiving CT scanning, 23 were diagnosed as having lacuna. 34 foci found on CT were distributed in the internal capsule, basal ganglia, thalamus and pons, with diameters varying from 3 to 22 mm. Combined CT and clinical findings showed that motor hemiplegia was present in 12 patients, pure sensory stroke in 1, sensory-motor stroke in 9, and the lock-in syndrome in 1.20 (87%) of the 23 patients partly or completely fulfilled the criteria for the lacuna syndrome. The detection of lacunae depends on the property of instrument, the method of scanning, and the thickness of slice. By showing some minor infarctions, CT has offered the possibility of diagnosis of lacunae.

Adult↗
PubMed1989

[A study on cytomegalovirus infection in 199 pregnant women and their infants].

Cytomegalovirus (CMV) infection is common in human, and exerts harmful effects during pregnancy upon fetuses. In order to get a clear knowledge of CMV infection rate in pregnant women and their infants and of the relationship between maternal infection and congenital infection in our city, we tried to detect the CMV specific IgG and IgM in 199 paired serum samples of mother and infant. The results showed that 183 maternal serum samples and 179 umbilical cord serum samples were CMV-IgG positive, a positive rate of 92% and 90% respectively. While 6 maternal serum samples and 7 umbilical cord serum sample were CMV-IgM positive, a positive rate of 3.0% and 3.5% respectively. The close correlation of CMV-IgM levels between mothers and their babies indicates that the infant may acquire congenital infection from his CMV-IgM positive mother.

Antibodies, Viral↗
PubMed1987

Plasma selenium content, platelet glutathione peroxidase and superoxide dismutase activity of residents in Kashin-Beck disease affected area in China.

The activity of platelet glutathione peroxidase, of platelet and erythrocyte superoxide dismutase and the concentration of plasma selenium and vitamin E were measured in two groups of residents in the Kashin-Beck disease affected area and in three from a non-affected area. Average plasma selenium levels and platelet glutathione peroxidase activity were significantly lower in the endemic area than in the non-endemic area, indicating that the residents in the endemic area are indeed in a low selenium status. There existed a significantly positive correlation, r = 0.94, n = 78, p less than 0.001, between platelet glutathione peroxidase activity and plasma selenium concentration over a range from 2 to 79 micrograms/L (mean values 5 to 66 micrograms/L). Platelet glutathione peroxidase also correlated well with plasma selenium in each group of residents with varying plasma selenium levels, demonstrating that determination of glutathione peroxidase activity in platelets can be used as an indicator for assessing low selenium status in humans. No significant difference of vitamin E levels was observed between the residents in the endemic and non-endemic areas. There were no statistically significant differences in the activity of superoxide dismutase between each two groups studied, showing that superoxide dismutase does not undergo a compensatory increase in the residents of low selenium status.

Adolescent↗
PubMed1986

Biosynthesis of prostaglandins by isolated and cultured airway epithelial cells.

The metabolism of arachidonic acid to prostaglandins and thromboxane by freshly isolated and cultured respiratory tract epithelial cells was examined by HPLC methods. Homogenates prepared from freshly isolated rat and rabbit tracheal epithelial cells did not convert arachidonic acid to prostaglandins. Rat tracheal epithelial cells however, did convert arachidonic acid to uncharacterized metabolites possibly hydroxyfatty acids. In contrast, rat tracheal epithelial cells grown in culture for 9 days acquired the capacity to convert arachidonic acid to PGE2 and related products while cultured rabbit tracheal epithelial cells converted arachidonic acid to TXB2. The conversion of arachidonic acid to PGE2 by rat tracheal cells was studied at various times in culture. The formation of PGE2 appeared to parallel the growth of the cultures. In contrast to freshly isolated rat tracheal cells, enriched rat Clara cell fractions were able to convert 14C-arachidonic acid to prostacyclin (PGI2) ans measured by HPLC analysis of its stable end product 6-keto PGF1 alpha. PGI2 was also the major metabolite of arachidonic acid produced by enriched rat alveolar type II cell fractions. PGF2 alpha, and hydroxyfatty acids were also formed. These results suggest that arachidonic acid metabolism differs in various types of respiratory tract cells and that maintenance of such cells in culture alters the pattern of arachidonic acid metabolism.

Animals↗
PubMed1983

Glutathione peroxidase (EC 1.11.1.9), glutathione-S-transferase (EC 2.5.1.13), superoxide dismutase (EC 1.15.1.1) and catalase (EC 1.11.1.6) activities in tissues of ducklings deprived of vitamin E and selenium.

Vitamin E and selenium deficiencies were produced in the Pekin duckling (Anser cinerens) and were characterized by the development of lesions after 14 d in gizzard, intestine, heart and skeletal muscle. The activities of glutathione peroxidase (EC 1.11.1.9), using hydrogen peroxide and cumene hydroperoxide as substrates, glutathione-S-transferase (EC 2.5.1.13), superoxide dismutase (EC 1.15.1.1) and catalase (EC 1.11.1.6) were measured in homogenate supernatant fractions of liver, heart, intestine, gizzard and skeletal muscle of deficient ducklings and of control birds given vitamin E or Se or both. Glutathione peroxidase activities were dramatically lower in tissues of Se-deficient ducklings, and this was unaffected by vitamin E. No adaptive changes were seen in the activity of the other enzymes, even after 21 d when the deficiency was severe. It appeared likely that the variability of the enzyme activities, other than glutathione peroxidase, in the different tissues studied might explain differences among the tissues in susceptibility to peroxidative damage.

Animals↗