Biomedical subjects

G Wang

Publications and source records attributed to G Wang.

At least 163 records · Page 9Linked to original sources

PubMed2001

Presence of DNA fragmentation and lack of neuroprotective effect in DFF45 knockout mice subjected to traumatic brain injury.

BACKGROUND: Apoptosis plays an important pathophysiologic role in neuronal cell loss and associated neurologic deficits following traumatic brain injury (TBI). DNA fragmentation represents one of the characteristic biochemical features of neuronal apoptosis and is observed after experimental TBI. DFF45 and DFF40 are essential for DNA fragmentation in various models of apoptosis. MATERIALS AND METHODS: We used mice deficient in DFF45 and wild-type controls. Oligonucleosomal DNA fragmentation induced by TBI was analyzed using in vivo and in vitro assays. Expression and integrity of DFF45 and DFF40 proteins was assessed by Western analysis. Other outcome measurements included neurologic scoring, learning/memory tests, lesion volume measurements (MRI), and assessment of cell viability in vitro among others. RESULTS: We compared the effects of controlled cortical impact (CCI) trauma in DFF45 knockout mice and wild-type controls. Analysis of TBI-induced DNA fragmentation in brain cortex from wild-type and DFF45 knockout mice indicates that, although somewhat delayed, oligonucleosomal cleavage of DNA occurs after TBI in DFF45 knockout mice. DFF45 knockouts showed no significant differences in behavioral outcomes or lesion volumes after TBI as compared to wild-type controls. Using an in vitro reconstitution system, we also demonstrated that cleavage of DFF45 by caspase-3 is not sufficient for DNA fragmentation induced by protein extracts from rat brain cortex. We found that endonuclease activity induced in rat brain cortex following TBI depends on the presence of Mg2+ and Ca2+, but is not inhibited by Zn2+. Primary neuronal cultures from DFF45 knockouts failed to show DNA laddering in response to staurosporine, but did show prominent, albeit delayed, DNA fragmentation following treatment with etoposide. In contrast, primary neurons from wild-type animals demonstrated marked DNA fragmentation following treatment with staurosporine or etoposide. CONCLUSIONS: The results of this study suggest that, in addition to DFF45/40, other endonucleases may be essential for chromatin degradation during neuronal apoptosis in adult brain after TBI.

Animals↗

PubMed2001

[Effect of grazing on microbiological processes of N2O production in grassland soils].

A laboratory incubation study on effect of grazing on microbiological processes of N2O production in Aneurolepidium chinese grassland soils by using the acetylene-inhibition method was firstly conducted and the seasonal variations of related bacteria groups and N2O fluxes were analyzed. Results suggested that grazing behavior altered the soil structure which were benefit to microbiological denitrification so that N2O emission from this steppe soil was reduced. It was the heterotrophic nitrification that is the key microbiological process for N2O production in the non-grazing and grazing semi-arid typical grassland soils in Inner Mongolia. The reasons why N2O flux from Inner Mongolia semi-arid typical grassland soils was lower were also explained in this paper.

Animals↗

PubMed2001

[Screening and characterization of human phage antibody to hepatitis C core antigen].

OBJECTIVE: To screen and characterize human phage antibody (ScFv) against hepatitis C core antigen. METHODS: The recombinant phages were panned by core antigen that was coated in a microtiter plate. After three rounds of biopanning, 48 clones were determined specific to core antigen. The specificity of each ScFv colone was determined by ELISA. The coding gene for HCV protein ScFv has been sequenced. RESULTS: Phage antibody for HCV core protein had a specific combination character with core antigen of hepatitis C virus. The DNA sequence data showed that the ScFv gene included 774 bp. CONCLUSIONS: Human single chain antibody to hepatitis C core antigen has been identified by means of the phage display technology.

Amino Acid Sequence↗

PubMed2001

[Relation between activities of hepatic and gastric alcohol dehydrogenases and formation of chronic alcoholic liver diseases].

OBJECTIVE: To investigate the role of hepatic and gastric alcohol dehydrogenases (ADH) in different pathologic stages of alcoholic liver disease (ALD). METHODS: Thirty-nine rats were divided into either model or control group at random. The ALD model was established by infusing alcohol into the stomach. The activity varieties of hepatic and gastric ADH were observed by optical microscopy after hepatic and gastric tissues had been stained by enzyme histo-cytochemistry assay and the activity alterations were also determined with a LUZEX-F analysis instrument as a semi-quantitative method. RESULTS: The activity of hepatic ADH gradually increased, but gastric ADH gradually decreased in ALD. There was a significant difference between model group and control one (P<0.05). CONCLUSIONS: The activity alterations of the hepatic and gastric ADH may play an important role in the onset and development of ALD.

Alcohol Dehydrogenase↗

PubMed2001

[Phosphorus behavior in soil-water system of paddy field and its environmental impact].

A field experiment with rice showed that P fertilizer application increased the concentrations of resin P in soil and total P in soil surface water, and both of them declined subsequently over time. Compared with applying mineral P fertilizer only, the integrated application of mineral-P and manure resulted in a higher resin P level within 20 days after P application. The total P concentration in soil surface water in the treatment of integrated application of mineral-P and manure was 3.4 times higher than that in the treatment of mineral-P fertilizer application only after 7 days of P application, and also, was 2.8 times higher than that in the treatment where P application rate was doubled. The potential of Ploss from surface water in the treatment of integrated application with manure was more than that in the treatment of applying-P fertilizer only. The effect of applied P sorts on P concentration in soil surface water could be ignored after 33 days of P application. Two drainages were conducted for rice growth, which caused the net P loss loading and its apparent P loss ratio in range of -0.038-0.076 kg.m-2 and 0.034-0.100%, respectively. To minimize P loss from rice production area, field drainage should be avoided in the initial week of P-fertilizer application or field harrowing.

Environment↗

PubMed2001

[Effect of elevated atmospheric CO2 concentration on Rhopalsiphum padi population under different soil water levels].

With the aim of forecasting the wheat-aphid relationships under different precipitation in the future atmospheric CO2 environment, the effects of different atmospheric CO2 concentration on Rhopalsiphum padi population under different soil water levels in Open-Top chambers were studied. The results showed that Rhopalsiphum padi population grew constantly with the continuous rising of atmospheric CO2 and it grew more quickly when CO2 concentration increased from 350 microliters.L-1 to 550 microliters.L-1. In each CO2 concentration treatment, R. padi population were distinct under different soil water level, and they were the highest under 60% of field water capacity treatment. When CO2 concentration increased from 350 microliters.L-1 to 550 microliters.L-1, the increase of R. padi population under 60% of field water capacity treatment was higher than that under 40% and 80% treatment. When CO2 concentration increased from 550 microliters.L-1 to 700 microliters.L-1, the increases of R. padi population under 60% and 40% soil water treatments were the same and both higher than that under 80% treatment. These results suggested that R. padi population would grow more quickly from the beginning to the middle of the 21st century and bring more damages to the wheat in arid and semiarid area.

Animals↗

PubMed2001

[Effect of Zn2+, Cd2+ and their combined on Ca, Fe and Mn uptake by wheat seedlings].

The effect of Zn, Cd and their combination on Ca, Fe and Mn uptake by wheat seedlings was studied with solution culture. The result shows the Zn and Cd contents of wheat increased with increasing concentrations of Zn2+ and Cd2+ in solution, while there was a difference between single and compound treatments. Zn affected Cd uptake by wheat, and Cd inhibited Zn uptake. The uptake of Ca and Mn reduced with the increase of Zn2+ and Cd2+ in solution. The uptake of Fe increased with increasing Zn2+ and Cd2+ concentrations in single treatment, while decreased in compound treatment. The interactive effect of Zn and Cd was also related to the parts of plants.

Cadmium↗

PubMed2001

[Characteristics of nitrobenzene containing wastewater catalytic oxidation degradation by Fenton reagent].

Through the alteration of the concentration of catalyst and oxidant, the rulers and dynamics of nitrobenzene oxidized by Fenton reagent in different concentrations were studied. The correlativity of the reaction time and relatively remain nitrobenzene was analyzed by the unitary linear regress equation. The result of the analysis proves that the coefficient was over the critical constant. The oxidation of nitrobenzene by Fenton reagent was in conformity with first-order dynamics model and the reaction rate constant was got at the same time. The idea, using the complex of Fe as the catalyst replacing Fe2+ in the Fenton Reaction, not only got a higher reaction velocity and efficiency, but also had a distinct exclusive to the degradation of nitrobenzene. The remove velocity of nitrobenzene was improved from 17.48 mg/(L.min) to 71.22 mg/(L.min), the remove rate in 5 minutes was from 9.74% to 91.79%. The nonhomogeneous catalyst made by the artificial zeolite with Fe-complex adsorbed had the same catalyzing behavior. In addition, ultraviolet radiation can also improves the Fenton reaction to some degree. These research works could demonstrate the good application potentiality of Fenton reagent in treating wastewater.

Catalysis↗

PubMed2001

[Study on anodic oxidation and hydrothermal treatment of titanium implants with thin hydroxyapatite layers: an implantational test in rabbits].

OBJECTIVE: To learn bone response to commercially pure titanium implants with anodic oxidation followed by hydrothermal treatment in vivo. METHODS: Tweleve rabbits were averagely divided into three groups. And 36 implants (9 polished, 9 roughened by grit-blasting, 9 treated with anodic oxidation followed by heat treatment and 9 treated with anodic oxidation followed by hydrothermal treatment) were randomly implanted into femur bones of each group rabbits. Implants were harvested at 4 W, 8 W and 16 W respectively. Slice about 30 microns thick were ground with a grinding machine and stained with 1% toluidine blue. The bone-implant interface was observed with light microscopy and scanning electron microscopy. Implant surface element contents were also detected with EDAX. RESULTS: Woven bone rapidly transferred to lamellae bone at 8 weeks for anodic oxidized implants followed by hydrothermal treatment, which appeared little woven bone and no hydroxyapatite debris between the interfacial zone at 16 weeks. In addition, Ca and P contents increased much more for hydrothermal treated implants after implantation compared with polished implants. CONCLUSIONS: Anodic oxidation followed with hydrothermal treatment of a titanium fixture could speed up woven bone transferring the lamellae bone at early time of implantation, which meant thin HA layers could accelerate bone healing at the implanted site and might shorten healing time. This superiority need more research in the future.

Animals↗

PubMed2001

[Use of microsatellites in zygosity diagnosis of twins].

OBJECTIVE: To diagnose zygosity of twins by microsatellite polymorphism. METHODS: One hundred and eighty-four samples, including 69 pairs of twins with the same gender and 6 pairs of twins with different gender were recruited. Seventeen sib pairs were also collected for controls. Nine highly polymorphic microsatellite loci were amplified by polymerase chain reaction (PCR) using fluorescence-labeled primers and the products were sized by automated fragment analysis after electrophoresis and laser detection. Zygosity was diagnosed by comparing the concordance of the genotype of the 9 markers. RESULTS: Sixty-three pairs of monozygotic (MZ) and 12 pairs of dizygotic (DZ) twins were assigned their zygosity by comparison of polymorphism of 9 microsatellite loci. Within each of the 63 monozygotic (MZ) pairs there was complete concordance. However, within each of the 12 dizygotic pairs and other 17 sib pairs, discordant loci were found. With five or six markers, the probability that any twin pair was MZ if all markers were concordant was 99% or 99.6%, respectively. With all the nine markers, the probability that any twin pair was MZ if all markers were concordant was 99.95%. CONCLUSION: The technology of gene scan and genotyping provides a rapid and reliable approach to zygosity detection.

DNA↗

PubMed2001

[The polymorphism of (CAG)n repeats within androgen receptor gene among Chinese male population].

OBJECTIVE: To investigate the polymorphism of (CAG)n repeats within androgen receptor (AR) gene among normal Chinese male population. METHODS: dsDNA cycle sequencing and[alpha-(32)PdCTP] incorporated asymmol/Letric PCR-denaturing polyacrylamide gel electrophoresis(PAGE) were used to determine the number of (CAG)n repeats in normal men (n=107). RESULTS: The number of polymorphic (CAG)n repeats ranges from 11 to 29; the most frequent repeat is 22(20/107); the less frequent repeats are 23(15/107), 24(11/107), 21(11/107) and 20(8/107). CONCLUSION: The AR gene (CAG)n exhibits polymorphism among normal male population and the present work could serve as a basis for further exploration of its pathological and genetic significance.

Adolescent↗

PubMed2001

[An experimental study on the change in cardiac sympathetic neuroelectrophysiology in severely scalded rats during early postburn stage].

OBJECTIVE: To investigate the mechanism and the rule of the change in cardiac sympathetic neuroelectrophysiology in severely scalded rats during early postburn stage, so as to explore the relationship between the change and postburn severe cardiac injury. METHODS: Forty-four Sprague-Dawley rats were randomly divided into normal (n = 6), sham injury (n = 8) and scalded (n = 20) groups. The rats in scalded group were inflicted by 30% TBSA III degree burn on the backs. The electric discharge activity of cardiac sympathetic nerve was observed and recorded by neuroelectrophysiological technique. The changes in ECG and myocardial mechanic indices were simultaneously observed. RESULTS: The activity of efferent cardiac sympathetic nerve increased immediately after scalding, but that of the afferent nerve increased obviously after about 90s incubation period. The activity of efferent nerve further increased after the increase of afferent activity, and this increase in both efferent and afferent nerves lasted for about 3 hours and decreased evidently thereafter. The change of afferent nerve was earlier than that of efferent nerve. The average electric discharge activity of cardiac sympathetic nerve increased with obvious fluctuation, which exhibited intermittent burst pattern at 1 PBH in some rats, in which frequent ventricular extrasystole appeared accompanying with the simultaneous increase in electric discharge burst in 4 rats. The postburn LVDP and +/- dp/dtmax in rats decreased significantly. CONCLUSION: The activities of both efferent and afferent cardiac sympathetic nerve increased dramatically in the early postburn stage. The change in efferent nerve activity could be affected to some degree by that of afferent nerve. This implied that the increase of the neuroelectrophysiological activity of cardiac sympathetic nerve might be one of the causes of early severe postburn cardiac injury.

Animals↗

PubMed2001

Prevention and treatment of hepatitis B relapse after liver transplantation.

OBJECTIVES: To investigate the effect of orthotopic liver transplantation (OLT) on hepatitis B(HB)-related diseases and the efficiency of prevention and treatment with lamivudine on recurrence of hepatitis B posttransplant in China. METHODS: Orthotopic liver transplantation (OLT) under veno-venous bypass was performed in 10, of whom 9 males had hepatitis B and 1 female had hepatocellular cancer (HCC) without HB pretransplant. Eight of the 9 males had fulminant hepatitis B (FHB) and they all had preoperative serious jaundice, ascites and coagulopathy. Six had encephalopathy; 1 was associated with acute renal failure, and 1 with gastrointestinal hemorrhage. Seven of the 10 patients had lamivudine to prevent reinfection with hepatitis B. RESULTS: Of the 8 patients who have survived for 2-12 months, 7 have survived for 6-12 months. Two died, one of recurrent FHB and the other from multi-organ failure (MOF). Seven preoprative HB patients of the 8 survivors have excellent liver function through 1 has positive HBsAg 6 months after OLT. One of the 8 survivors, the female with HCC pretransplant, suffered hepatitis B 6 months after OLT and her hepatic function has been gradually improving with lamivudine therapy. CONCLUSIONS: OLT is an effective therapy for certain cases of FHB and HCC and lamivudine may prevent recurrence of hepatitis B after OLT.

Adult↗

PubMed2001

Effect of ipratropium bromide on airway and pulmonary muscarinic receptors in a rat model of chronic obstructive pulmonary disease.

OBJECTIVE: To observe the level of muscarinic receptors in airway and lung tissues, and the effect of inhaled ipratropium bromide on these receptors in a rat model of chronic obstructive pulmonary disease (COPD). METHODS: This model was developed by exposure of rats to 250 ppm SO2 gas, 5 h/d, 5 d/wk, for a period of 7 wk. The COPD rats inhaled 0.025% aerosolized iratropium bromide for 20 min, 2 times daily, in an airtight chamber. Muscarinic receptors in airway and lung tissues of normal rats, ipratropium bromide-treated COPD rats and the recovering COPD rats were measured by the radio-ligand binding assay. RESULTS: Airway/lung pathology and pulmonary function tests showed that chronic SO2 exposure caused pathophysiologic changes similar to those observed in human COPD. The density (0.038 +/- 0.011, pmol/mg protein) and affinity (Kd, 23 +/- 11 pmol/L) of muscarinic receptors in airway and lung tissues of COPD rats were not changed compared with those of normal control rats (0.030 +/- 0.008 and 29 +/- 19, respectively, P > 0.05). Densities of the muscarinic receptors were not changed after inhalation of ipratropium bromide for 5 days, but increased significantly after inhalation for 30 days, as compared with those of the untreated COPD rats. The muscarinic receptors returned the normal levels at day 6 after cessation of ipratropium bromide treatment. There were no differences among different groups of rats in equilibrium dissociation constants (Kd). CONCLUSION: A rat model of COPD with pathophysiologic changes similar to the human counterpart was developed using chronic SO2 exposure. There was no significant change in the number and function of muscarinic receptors in airway and lung tissues of the COPD rats, but upregulation of the muscarinic receptors was observed after long-term inhalation of ipratropium bromide.

Animals↗

PubMed2001

Apolipoprotein E gene polymorphism and its association with human longevity in the Uygur nationality in Xinjiang.

OBJECTIVE: To study the relationship between apoE alleles and life-span. METHODS: Apolipoprotein E genotypes were determined in 164 unrelated Uygurs including 35 persons aged 90 years or older, 71 men aged 20-35 and 54 men with myocardial infarction by using polymerase chain reaction-restriction fragment length polymorphism. Apolipoprotein E gene polymorphism was analyzed among three groups. RESULTS: There was statistically significant difference in the epsilon 4 allele frequencies among three groups. The epsilon 4 allele frequency in olds was the lowest (0.057), while in patients suffering from myocardial infarction (MI) was the highest (0.213). In MI patients the average age of first attack in epsilon 4 allele carriers was significantly younger than that of non-carries, 51.3 and 58.3 years, respectively (P < 0.05). CONCLUSION: ApoE genotype may have some impact on human longevity.

Adult↗

PubMed2001

The association between PPP1R3 gene polymorphisms and type 2 diabetes mellitus.

OBJECTIVE: To detect the relationship between the polymorphism of the glycogen-targeting regulatory subunit of the skeletal muscle glycogen-associated protein phosphatase 1 (PPP1R3) gene and type 2 diabetes by case-control study. METHODS: We genotyped the PPP1R3 gene Asp905Tyr polymorphism and a common 3'-untranslated region AT (AU)-rich element (ARE) polymorphism in 101 type 2 diabetic patients and 101 controls by oligonucleotide ligation assay (OLA) and polyacrylamide gel elecrophoresis, respectively. RESULTS: Subjects with Tyr/Tyr genotypes whose body mass index (BMI) < 25 were used as the reference group. Those whose BMI > or = 25 with Asp905 had a 3.66-fold increase (95% CI: 1.48-9.06, P = 0.005) in type 2 diabetes risk. No association was found between 3'UTR ARE polymorphism and type 2 diabetes mellitus (OR = 1.15; 95% CI: 0.62-2.14, P = 0.65). CONCLUSION: A joint effect between the Asp905 and BMI increases the risk of type 2 diabetes, and Asp905Tyr and ARE polymorphism of PPP1R3 gene are not the major diabetogenic gene variants in Chinese population.

AT Rich Sequence↗

PubMed2001

[The clinical features and prognostic factors of 22 patients with primary central nervous system lymphoma].

OBJECTIVE: The authors present a retrospective analysis of 22 patients with primary central nervous system lymphoma(PCNSL) in order to provide a reasonable basis for the diagnosis and treatment of the disease. METHODS: This report involves a clinicopathological study of 22 patients with histologically proven PCNSL, all diagnosed between January 1993 and May 2000. Univariate and multivariate regression analysis are used to determine prognostic factors significantly associated with an unfavorable or favorable impact on survival. RESULTS: The cohort included 11 men and 11 women whose median age at diagnosis was 49.5 years. At the end point of follow-up, 11 died. The median survival time for the patients in study was 14.5 months. With univariate and multivariate regression analysis, prognostic factors significantly associated with survival included intrathecal injection(P = 0.005) and local/diffuse neurological deficit (P = 0.031). CONCLUSION: There continues to be a significantly increasing incidence of PCNSL. This survey throws light on the clinical and prognostic features of this uncommon disease. Through univariate and multivariate regression analysis the authors highly recommend a therapeutic regime including surgery, intrathecal injection and chemotherapy, especially those drugs capable of passing blood-brain barrier, for example high dose MTX.

Adolescent↗

PubMed2001

Alpha 1-antitrypsin and alpha 1-acid glycoprotein reduce the sensitivity of human dermal fibroblast to endotoxin.

OBJECTIVE: To test the hypothesis that acute phase reactants, such as alpha 1-antitrypsin and alpha 1-acid glycoprotein, could protect mammalian cells from further damage. METHODS: Human dermal fibroblasts (5 x 10(4)) were cultured with DMEM plus 10% FBS at 37 degrees C in a 5% CO(2) incubator. Different doses of LPS (lipo polysaccharide) and/or acute phase reactants were added. After 24 hours, the cultured supernatant was aspirated, the cells were washed, fixed and stained by methylene blue. The unbound stain was washed off. The stained cells were solubilize d in 0.1 ml of 1% Triton X-100. The absorbance of each well was measured us ing an ELISA spectrophotometer. The concentration of LPS which decreased the absorbance to 70% of the control (LPS-free) cultures was defined as LD(30). RESULTS: In order to achieve LD(30) in the presence of acute phase proteins, it was necessary to alter the LPS concentrations. The LD(3 0) of LPS treated with 0, 0.5, 2, 10 mg/ml antitrypsin and 0, 0.5, 2, 10 mg/ml glycoprotein was 5.4, 6.5, 7.6, 14.2 mg/ml and 5.2, 5.9, 6.9, 10.5 mg/ml, respectively. Statistically, with the treatment of more than 2 mg/ml antitrypsin or glycoprotein, LD(30) increased significantly. CONCLUSIONS: Our data show that fibroblasts are susceptible to the direct toxicity of LPS. Alpha 1-antitrypsin and alpha 1-acid glycoprotein can reduce the toxicity and/or increase the tolerance of mammalian cells to LP S.

Acute-Phase Reaction↗