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G Qin

Publications and source records attributed to G Qin.

At least 37 records · Page 2Linked to original sources
PubMed1999

[Identification and characterization of HIV-1 subtype D strain in China].

OBJECTIVE: Through sequence analysis of HIV-1 gag, tat and env regions, the subtype D HIV-1 had been identified appering in China. METHODS: The blood was collected from HIV-1 infected individual (SC9 712) in Sichuan Province. The peripheral blod mononuclear cells (PBMCs) were isolated from the blood by ficoll and the genomic DNA was extracted. The gag gene, the C2-V3 of the env gene and the first exon of tat gene were amplified by nested-PCR and sequenced directly. RESULTS: The genetic distance respectively is 7.56% in tat gene between SC9 712 and UG274A, 9.59% and 9.94% in gag gene between SC9 712 and K31 and VI203, 13.86% in env gene between SC9 712 and MAL. On the phylogenetic tree the SC9 712 HIV-1 strain clustered with the Africa subtype D strains UG274A, K31, VI203 and MAL. The above data demonstrated that SC9 712 was subtype D HIV-1 strain. Epidemiological data showed that SC9 712 virus was from a person who had worked in Africa. CONCLUSION: The results indicated that the person who came back from Africa had transmitted the subtype D of HIV-1 from Africa to China.

Base Sequence↗
PubMed1999

Role of the scavenger receptor MARCO in alveolar macrophage binding of unopsonized environmental particles.

Alveolar macrophages (AMs) avidly bind and ingest unopsonized environmental particles and bacteria through scavenger-type receptors (SRs). AMs from mice with a genetic deletion of the major macrophage SR (types AI and AII; SR-/-) showed no decrease in particle binding compared with SR+/+ mice, suggesting that other SRs are involved. To identify these receptors, we generated a monoclonal antibody (mAb), PAL-1, that inhibits hamster AM binding of unopsonized particles (TiO2, Fe2O3, and latex beads; 66 +/- 5, 77 +/- 2, and 85 +/- 2% inhibition, respectively, measured by flow cytometry). This antibody identifies a protein of approximately 70 kD on the AM surface (immunoprecipitation) that is expressed by AMs and other macrophages in situ. A cDNA clone encoding the mAb PAL-1-reactive protein isolated by means of COS cell expression was found to be 84 and 77% homologous to mouse and human scavenger receptor MARCO mRNA, respectively. Transfection of COS cells with MARCO cDNA conferred mAb-inhibitable TiO2 binding. Hamster MARCO also mediates AM binding of unopsonized bacteria (67 +/- 5 and 47 +/- 4% inhibition of Escherichia coli and Staphylococcus aureus binding by mAb PAL-1). A polyclonal antibody to human MARCO identified the expected approximately 70-kD band on Western blots of lysates of normal bronchoalveolar lavage (BAL) cells (>90% AMs) and showed strong immunolabeling of human AMs in BAL cytocentrifuge preparations and within lung tissue specimens. In normal mouse AMs, the anti-MARCO mAb ED31 also showed immunoreactivity and inhibited binding of unopsonized particles (e.g., TiO2 approximately 40%) and bacteria. The novel function of binding unopsonized environmental dusts and pathogens suggests an important role for MARCO in the lungs' response to inhaled particles.

Amino Acid Sequence↗
PubMed1999

Effects of environmental aerosols on airway hyperresponsiveness in a murine model of asthma.

Increased morbidity in persons suffering from inflammatory lung diseases, such as asthma and bronchitis, has been associated with air pollution particles. One hypothesis is that particles can cause an amplification of the pulmonary inflammation associated with these diseases, thus worsening affected individuals' symptoms. This hypothesis was tested in a murine model of asthma by inhalation exposure to (1) concentrated air particles (CAPs), (2) the leachate of residual oil fly ash (ROFA-S), and (3) lipopolysaccharide (LPS). Allergen-sensitized mice (ip ovalbumin, OVA) were 21 days old when challenged with an aerosol of 3% OVA in phosphate-buffered saline (PBS) for 10 min (controls were challenged with PBS only) for 3 days. On the same days, mice were further exposed to 1 of 3 additional agents: CAPs (or filtered air) for 6 h/day; LPS (5 microg/ml, or PBS) for 10 min/day; or ROFA-S (leachate of 50 mg/ml, or PBS) for 30 min on day 2 only. At 24 h later, mice challenged with OVA aerosol showed airway inflammation and airway hyperresponsiveness (AHR) to methacholine (Mch), features absent in mice challenged with PBS alone. Both OVA- and PBS-challenged mice subsequently exposed to ROFA-S showed increased AHR to Mch when compared to their respective controls (OVA only or PBS only). In contrast, when OVA-challenged mice were further exposed to CAPs or LPS, no changes in AHR were seen in comparison to mice challenged with OVA only. Bronchoalveolar lavage (BAL) analysis and histopathology 48 h postexposure showed OVA-induced allergic inflammation. No significant additional effects were caused by CAPs or ROFA-S. LPS, in contrast, caused significant increases in total cell, macrophage, and polymorphonuclear cell numbers. The data highlight discordance between airway inflammation and hyperresponsiveness.

Air Pollutants↗
PubMed1999

[A study on major chemical components of Uvaria grandiflora].

OBJECTIVE: To make clear the chemical constituents of Uvaria grandiflora (Annonaceae). METHODS: Purification was performed using sephadex LH-20 permeation and silica gel chromatography. Structures of the purified components were determined on the basis of 1H, 13C NMR analysis and also by comparison with those of authentic compounds. RESULTS: Two major triterpenes, suberosol and lupeol, were identified. CONCLUSION: This paper is the first report on the identification of suberosol and lupeol from the gunus Uvaria.

Pentacyclic Triterpenes↗
PubMed1998

Enhancement of aflatoxin B1-induced enzyme altered hepatic foci in rats by treatment with carbon tetrachloride.

The effect of carbon tetrachloride (CCl4) on aflatoxin B1 (AFB1)-induced enzyme altered hepatic foci has been examined in young male Fischer rats given AIN-76A diet. A single i.p. dose of AFB1 (0.2 mg/kg body wt) was given to rats 24 h after partial hepatectomy. Two weeks later, CCl4 (0.8 ml/kg body wt) was injected i.p. once a week for 9 weeks. Animals were sacrificed 24 h after the last dose of CCl4 and glutathione S-transferase placental form (GST-P) and gamma-glutamyl transpeptidase (GGT) positive hepatic foci were analyzed by immunohistochemical and histochemical methods, respectively. Ten weeks after AFB1 dosing, treatment with CCl4 increased the number of AFB1-induced enzyme altered foci several fold and produced a ten to twenty-fold increase in area and volume. GST-P was more sensitive than GGT in detecting AFB1-induced enzyme altered foci. Treatment with AFB1 or CCl4 produced mild hepatic fibrosis in zones 1 and 3 respectively, whereas both treatments produced severe fibrosis in zones 1 to 3 areas. Treatment with CCl4 after AFB1 dosing lowered hepatic GSH levels by 20% and increased lipid peroxidation by 40%. It appears that CCl4, by being an effective enhancer of AFB1-induced enzyme altered hepatic foci in the rat, may mimic cirrhosis observed in human hepatocellular carcinoma.

Aflatoxin B1↗
PubMed1998

Antifungal alkaloids and limonoid derivatives from Dictamnus dasycarpus.

From the root bark of Dictamnus dasycarpus (Rutaceae), four limonoid derivatives, two furoquinoline alkaloids, five limonoids, two sesquiterpenes and three steroids were isolated and their structures elucidated on the basis of various spectroscopic methods. Among the identified compounds, one was determined to be a new natural product, 6 beta-hydroxyfraxinellone, while six compounds were found to be active against the plant pathogenic fungus Cladosporium cucumerinum. The relationship between the structures of limonoid derivatives and their inhibitory activity against fungal growth was investigated.

Alkaloids↗
PubMed1998

[Subtype and sequence analysis of the C2-V3 region of gp120 genes among HIV-1 strains in Sichuan province].

Nine DNA fragments of HIV-1 env gene were amplified by PCR from uncultured peripheral blood mononuclear cells (PBMCs) obtained from HIV-1 sero-positive intravenous drug users (IDUs) in Sichuan province, in mid 1996. Their C2-V3 region (about 450 bp) was sequenced. Sequence analysis showed that there were two HIV-1 subtypes B and C, with 1.4% and 2.6% gene divergence inside each subtype, in Sichuan. The 5 subtype B strains, when comparing with sequences of several reference HIV-1 strains, were found similar to these identified in Thailand, Myanma and Yunnan province. The nucleotide sequence divergence between them was ranged from 3.6% to 4.3%. Meanwhile, the 4 subtype C strains except sc3, were most close to those found in India as well as in Yunnan province, and both their nucleotide sequence divergence was 3.1%. The sc3 strain belonged to subtype C but had larger genetic distance, between 10.1%-17.2%. Above results suggested a recent epidemic of both subtype HIV-1 strains in Sichuan provine and they were very close to those identified in Yunnan province: The subtype C strain of sc3 is special and its source remains not clear.

China↗
PubMed1998

[Misdiagnosis of tired fracture of distal segment of femur].

OBJECTIVE: To improve the diagnosis of tired fracture of the distal segment of femur, and to avoid its misdiagnosis. METHOD: Misdiagnosis of 5 patients with tired fracture of distal segment of the femur was reviewed. RESULT: Five male patients, aged 18 to 23 years had the lesion for 3 to 6 weeks. They had long tough experience of sports. The lesion was considered at first as osteosarcoma by radiograph and biopsy. It was eventually diagnosed as tired fracture of distal segment of the femur. Symptoms were relieved or disappeared after proper treatment. Follow-up for 7 to 18 months showed good results. CONCLUSION: The key to avoid misdiagnosis and mistreatment of the fracture is to know its causes, morphological features of fracture healing, and correct pathologic diagnosis.

Adolescent↗
PubMed1997

p53 protein expression in patients with hepatocellular carcinoma from the high incidence area of Guangxi, Southern China.

Mutation of the p53 gene has been reported in hepatocellular carcinoma (HCC) occurring worldwide. The most frequent p53 mutation has been found in HCCs in regions with high hepatitis B virus (HBV) infection and intake of aflatoxin B1 (AFB1). The aim of our study was to examine p53 protein expression in HCCs from a high incidence area of Guangxi, Southern China, where HBV infection and dietary intake of AFB1 are high. Immunohistochemical staining of p53 protein was carried out using a polyclonal rabbit antibody (CM-1). Serial sections were also stained for hepatitis B surface antigen and core antigen. p53 Protein expression was detected in 13 (43.3%) of the 30 HCCs. Expression of p53 was found in 25.0% (1/4) of the < or = 5.0 cm diameter HCCs, in 36.8% (7/19) of the 5.1-10.0 cm diameter HCCs and in 71.4% (5/7) of the >10.0 cm diameter HCCs. Expression of p53 was observed more in moderately and poorly differentiated than in the well differentiated HCCs and more frequently seen in HCCs from younger patients. These data indicate that there is a close association between p53 protein expression and tumor size, histological grade and age of patients. Twenty-seven out of 30 cases (90.0%) were positive for HBV. No significant association between p53 expression and sex. HBV infection, cirrhosis or alpha-fetoprotein has been found.

Adult↗
PubMed1997

Inhibition of aflatoxin B1-induced initiation of hepatocarcinogenesis in the rat by green tea.

Several studies have demonstrated that green tea (GT) inhibits various chemically induced cancers in experimental animals. In the present study, effect of GT has been examined on the initiation of aflatoxin B1 (AFB1)-induced hepatocarcinogenesis in the rat. Young male Fischer rats were given AIN-76A diet with or without 0.5% instant GT powder in their drinking water for 2 or 4 weeks. Initiation was examined by hepatic AFB1-DNA binding in vivo, AFB1 metabolism in vitro and by the appearance of AFB1-induced glutathione S-transferase placental form (GST-P)-positive hepatocytes detected by immunohistochemical method. There was no influence of GT feeding on microsome-mediated AFB1 binding to exogenous DNA. However, GT feeding enhanced microsome-mediated formation of non-toxic hydroxylated metabolites of AFB1 by 2-3-fold. Hepatic nuclear AFB1-DNA binding in vivo was significantly inhibited by about 20-30% in animals pretreated with GT: AFB1-induced GST-P positive single hepatocytes were inhibited significantly by 60-70% in rats pretreated with GT. These results suggest that feeding of GT inhibits initiation of AFB1-induced hepatocarcinogenesis in the rat by modulation of AFB1 metabolism, thereby inhibiting AFB1-DNA binding and AFB1-induced GST-P-positive hepatocytes.

Aflatoxin B1↗
PubMed1996

Studies on bioactive saponins from Chinese medicinal plants.

In our recent studies on bioactive saponins, two Chinese medicinal plants: Mussaenda pubescens Ait.f (Rubiaceae) and Clematis chinensis Osbeck (Ranunculaceae), were investigated. Of the two medicinal plants, M. pubescens is a Chinese folk medicine which has been used as a diuretic, antiphlogistic, diaphoretic and antipyretic agent, and has also been used to detoxify mushroom poisons and to terminate early pregnancy. Clematis chinensis is a Chinese traditional medicine which has been used as an analgesic, diuretic, antitumor, antiinflammatory and insecticidal agent for ages. As a result of our studies, eighteen saponins were identified from M. pubescens, among which seventeen were new compounds, while eleven saponins were isolated from C. chinensis, three of which were new compounds. In the course of our structural studies, mass fragment analysis in FAB-mass spectra and 1H- and 13C-NMR spectra were used to determine the structures of the sapogenin and oligosaccharide moieties. In those more complicated and minor saponins, various 2D-NMR experiments were carried out on 400-, 500- or 600-MHz NMR instruments, which permitted the identification of new sapogenins in glycoside form. In addition, it was also possible to assign all the proton and carbon signals of the sugar units on the basis of 1H-1H DQF COSY, TOCSY and HMQC spectra, which further permitted the establishment of linkage sites and sequences among the sugar units and aglycones by means of NOESY, ROESY and HMBC spectra. When the proton signals of sugar units are overlapped seriously in 1H-NMR spectra, peracetylation is a very helpful technique which can spread proton signals in wider range, thus simplifying their assignment by means of 2D-NMR spectra. When some of the sugar proton signals of a peracetylate are also overlapped coincidentally, alternation of deuterated solvents for measuring NMR spectra can circumvent the difficulties. Pharmacological tests indicated that mussaendoside O, the most abundant saponin from M. pubescens, can inhibit significantly the secretions of the lachrymal and salivary glands induced by galanthamine, and can also inhibit the contraction of the isolated longitudinal muscle strip from guinea pig ileum evoked by an M-Ach receptor agonist (carbachol, 10(-6) M) at concentrations of 10(-4) and 10(-5) M. From these results, the saponin should be an antagonist of the M-Ach receptor, and was presumed to be responsible for its antitoxicity activity toward some mushroom poisons of medicinal plant origin. In addition, mussaendoside O also showed immunopromotive and hemolytic activities.

Animals↗
PubMed1996

Saponins from Mussaenda pubescens.

From the hydrophilic fractions of aerial parts of Mussaenda pubescens, three new saponins named mussaendosides D, E and H, along with a known saponin, mussaendoside S, were isolated. Their structures were elucidated on the basis of chemical and spectral evidence.

Carbohydrate Sequence↗
PubMed1996

Saponins from Clematis chinensis.

From ethanol extracts of the roots of Clematis chinensis, a new saponin, named clematichinenoside C, was isolated and its structure was established as 3-O-beta-D-glucopyranosyl-(1-4)-beta-D-ribopyranosyl-(1-3)-alpha-L - rhamnopyranosyl-(1-2)-alpha-L-arabinopyranosyl oleanolic acid 28-O-alpha-L-rhamnopyranosyl-(1-4)-beta-D-glucopyranosyl- (1-6)-beta-D-glucopyranosyl ester by spectroscopic and chemical means. In addition, one known saponin, huzhongoside B, was identified in the plant.

Carbohydrate Sequence↗
PubMed1996

Saponins from Mussaenda pubescens.

Two new triterpenoid saponins, named mussaendosides G and K, were isolated from aerial parts of Mussaenda pubescens by normal and reverse phase chromatography. On the basis of chemical and spectroscopic methods, their structures have been elucidated as heinsiagenin A 3-O-{alpha-L-rhamnopyranosyl(1-->2)-[beta-D-glucopyranosyl (1-->6)]-beta-D-glucopyranosyl(1-->2)}-alpha-L -rhamnopyranosyl(1-->4)-O-beta-D-glucopyranoside and 3 beta,19 alpha-dihydroxyl-olean-12-en-24, 28-dioic acid-24,28-di-O-beta-D-glucopyranoside, respectively.

Carbohydrate Conformation↗
PubMed1996

[The pulmonary function in scoliotic patient].

This paper investigated preoperative pulmonary functions in 134 scoliotic patients, of whom 32 cases was followed up for their postoperative pulmonary functions. The results show that the bigger the Cobb of the scoliosis, the greater the damages of the pulmonary functions. Congenital scoliosis is more severely affected by pulmonary functions than idiopathic scoliosis. There was no significant difference among the different sections of scoliosis with regard to their effect on the pulmonary functions. The authors concluded that the Harrington Instrumentation improved pulmonary functions in scoliosis.

Adolescent↗