Biomedical subjects

S Zhu

Publications and source records attributed to S Zhu.

At least 109 records · Page 6Linked to original sources

PubMed2000

Polymorphisms in the IL4, IL4RA, and FCERIB genes and asthma severity.

BACKGROUND: Genetic polymorphisms have been associated with asthma and asthma severity. OBJECTIVE: We sought to determine whether 3 polymorphisms were associated with severe asthma indicated either by the occurrence of a fatal (or near-fatal) asthma attack or by severe airflow obstruction. METHODS: We obtained DNA and clinical data from asthmatic subjects who either died or nearly died during an asthma attack and from a group of subjects with mild-to-moderate asthma who had never experienced a fatal or near-fatal asthma episode. These groups were compared with a group of nonatopic nonasthmatic control subjects. The level of airflow obstruction (FEV(1) percent predicted) in the subjects with mild-to-moderate asthma was used as an additional measure of disease severity. The subjects were genotyped for the IL4*C-589T promoter polymorphism and the IL4RA*Q576R and the FCERIB*E237G amino acid substitutions. RESULTS: The results showed that the FCERIB*E237G and IL4RA*Q576R polymorphisms were not associated with fatal or near-fatal asthma. However, the IL4*-589T allele was significantly increased in the subjects with fatal or near-fatal asthma compared with nonasthmatic subjects (odds ratio [OR], 1.8; P =.02) and subjects with mild-to-moderate asthma (OR, 1.9; P =.02). There was no interaction between the IL4*-589T and IL4RA*576R alleles. Of the 3 polymorphisms, only the IL4RA*576R allele was associated with severe airflow obstruction (OR, 8.2; P =.01). CONCLUSION: These data suggest that the IL4*-589T allele is a risk factor for life-threatening asthma and that the IL4RA*576R allele is a risk factor for a low level of lung function in asthmatic subjects.

Airway Obstruction↗

PubMed2000

Evidence for the existence of insect defensin-like peptide in scorpion venom.

Insect defensin refers to a group of antibacterial peptides derived from a variety of insect species as well as from scorpion and possessing a three-dimensional structure highly similar to that of scorpion toxins. A full-length cDNA encoding an insect defensin-like peptide was isolated from the venom gland cDNA library of the Chinese scorpion Buthus martensii Karsch. The precursor, the overall organization of which is similar to that of insect defensins, consists of 61 amino acid residues with a putative signal peptide of 15 residues, a propeptide of 7 residues, and a mature peptide of 39 residues (named BmTXKS2). The positions of six cysteines and a conserved glycine in mature BmTXKS2 are the same as those in LqDef, the first defensin found in scorpions, which suggests these peptides should present a similar cysteine-stabilized alphabetamotif. Phylogenetic analysis further shows that the structure of BmTXKS2 is closer to that of ancient defensins (e.g., LqDef and AaDef, two insect defensins present in the scorpion hemolymph) than to scorpion toxins.

Amino Acid Sequence↗

PubMed2000

Comparative chemopreventive mechanisms of green tea, black tea and selected polyphenol extracts measured by in vitro bioassays.

Black tea extracts (hot aqueous, polyphenols and theaflavins) and green tea extracts (hot aqueous, polyphenols, epicatechin, epicatechin gallate, epigallocatechin and epigallocatechin gallate) were tested in nine standardized cell culture assays for comparative cancer chemopreventive properties. Most black and green tea extracts strongly inhibited neoplastic transformation in mouse mammary organ cultures, rat tracheal epithelial cells and human lung tumor epithelial cells. Nearly all tea fractions strongly inhibited benzo[a]pyrene adduct formation with human DNA. Induction of phase II enzymes, glutathione-S-transferase and quinone reductase, were enhanced by nearly all tea fractions, while glutathione was induced by only a few fractions. Ornithine decarboxylase activity was inhibited by nearly all the green tea fractions, but none of the black tea fractions. 12-O-tetradecanoylphorbol-13-acetate-induced free radicals were inhibited by most tea fractions. These results provide strong evidence of both anti-mutagenic, anti-proliferative and anti-neoplastic activities for both black and green tea extracts. Such anticancer mechanisms may well be responsible for the cancer preventive efficacies seen in both experimental and human studies.

Animals↗

PubMed2000

Carbon dioxide enhances nitration of surfactant protein A by activated alveolar macrophages.

We assessed whether reactive oxygen-nitrogen intermediates generated by alveolar macrophages (AMs) oxidized and nitrated human surfactant protein (SP) A. SP-A was exposed to lipopolysaccharide (100 ng/ml)-activated AMs in 15 mM HEPES (pH 7.4) for 30 min in the presence and absence of 1.2 mM CO(2). In the presence of CO(2), lipopolysaccharide-stimulated AMs had significantly higher nitric oxide synthase (NOS) activity (as quantified by the conversion of L-[U-(14)C]arginine to L-[U-(14)C]citrulline) and secreted threefold higher levels of nitrate plus nitrite in the medium [28 +/- 3 vs. 6 +/- 1 (SE) nmol. 6.5 h(-1). 10(6) AMs(-1)]. Western blotting studies of immunoprecipitated SP-A indicated that CO(2) enhanced SP-A nitration by AMs and decreased carbonyl formation. CO(2) (0-1.2 mM) also augmented peroxynitrite (0.5 mM)-induced SP-A nitration in a dose-dependent fashion. Peroxynitrite decreased the ability of SP-A to aggregate lipids, and this inhibition was augmented by 1.2 mM CO(2). Mass spectrometry analysis of chymotryptic fragments of peroxynitrite-exposed SP-A showed nitration of two tyrosines (Tyr(164) and Tyr(166)) in the absence of CO(2) and three tyrosines (Tyr(164), Tyr(166), and Tyr(161)) in the presence of 1.2 mM CO(2). These findings indicate that physiological levels of peroxynitrite, produced by activated AMs, nitrate SP-A and that CO(2) increased nitration, at least partially, by enhancing enzymatic nitric oxide production.

Carbon Dioxide↗

PubMed2000

Polymorphisms of the IL-4, TNF-alpha, and Fcepsilon RIbeta genes and the risk of allergic disorders in at-risk infants.

Polymorphisms in the TNF-alpha (A-308G), IL-4 (C-589T), and Fcalpha RIbeta (E237G) genes have been associated with asthma and related phenotypes. To determine the predictive value of these polymorphisms we have assessed their relative risk (RR) for the development of atopy, asthma, and rhinitis in a high-risk infant population that is being followed longitudinally from birth. DNA was extracted and genotyped for 373 infants and 572 parents for each polymorphism. Phenotypic data were collected for atopy and allergic diseases in the infants at 12 mo of age. The prevalence of these phenotypes in the 281 white infants was compared in each genotypic group. There were no differences in the prevalence of any phenotype between genotypes of the TNF-alpha and Fcalpha RIbeta polymorphisms. However, we found that the IL4-589*T allele was associated with "probable" asthma (RR = 4.1) and that homozygotes for the IL4-589*T allele had an increased risk for the development of rhinitis (RR = 2.4). Using the transmission disequilibrium test, an association of IL4-589*T with atopy was found. We conclude that IL-4-589*T, but not TNF-alpha-308*2 or Fcalpha RIbeta*G, is a risk factor for the development of atopy, asthma, and rhinitis by 12 mo of age.

Asia↗

PubMed2000

Protein nitration, metabolites of reactive nitrogen species, and inflammation in lung allografts.

This study investigated nitration and chlorination of epithelial lining fluid (ELF) proteins in patients (n = 29) who had undergone lung allotransplantation. We assayed lung lavage nitrotyrosine (NT) and chlorotyrosine (CT) by HPLC. We measured NT, nitrate (NO(3)(-)), and nitrate (NO(2)(-)) in bronchoalveolar lavage fluid (BALF) and total nitrite (NO(2)(-) + NO(3)(-)) in serum of another group of lung transplant patients (n = 82). In the first group (n = 29), percent nitration of tyrosines (Tyr) (NT/total Tyr x 100) in BALF proteins was: patients, 0.01 (0.00-0.12)%; median (25th-75th% confidence interval), and control subjects 0.01 (0.00-0.02)%. CT (CT/ total Tyr x 100) occurred only in the patients' BALF: 0.01 (0. 00- 0.02)%. In the second group (n = 82), nitrotyrosine (NT) was detected by ELISA in the BALF of patients: 9 (0-41) pmol/mg pro and control subjects: 28 (26-33). Total nitrite (NO(2)(-) + NO(3)(-)) in BALF of the patients: 3.3 (1.9-5.1) microM significantly exceeded that in control subjects: 1.3 (0.8-1.3) microM; p = 0.0133. Serum nitrite also was significantly higher in patients: 37 (26-55) microM than control subjects: 19 (17-20) microM; p = 0.0037. Airway inflammation in transbronchial biopsies (B score) correlated with NT in BALF (p = 0.0369). Lung transplants have increased airway concentrations of reactive nitrogen species (RNS) metabolites. NT, a marker of peroxynitrite (ONOO(-)), is related to the degree of airway inflammation in lung transplants.

Adult↗

PubMed2000

Cyclophosphamide prevents systemic keratinocyte growth factor-induced up-regulation of surfactant protein A after allogeneic transplant in mice.

We reported that systemic keratinocyte growth factor (KGF) given before bone marrow transplantation (BMT) prevents allogeneic T cell-dependent lung inflammation assessed on Day 7 post-BMT, but the antiinflammatory effects of KGF were impaired in mice injected with both T cells and conditioning regimen of cyclophosphamide (Cy). Intratracheal KGF is known to stimulate the expression of surfactant protein A (SP-A), an oxidant-sensitive T cell immunomodulator produced by alveolar type II cells. We hypothesized that systemic KGF up-regulates SP-A after allogeneic BMT, and the addition of Cy may interfere with the ability of KGF to enhance SP-A production. The subcutaneous administration of recombinant human KGF (5 mg/kg on Days -6, -5, and -4 pre-BMT) increased SP-A protein and mRNA in allogeneic T cell-recipient irradiated mice measured on Day 7 post-BMT. In contrast, the same KGF treatment in irradiated mice given T cells and Cy failed to up-regulate SP-A mRNA and protein expression. In mixed lymphocyte reaction experiments designed to simulate the in vivo model, the addition of human SP-A (5-50 microg) to alloactivated T cells suppressed the production of interleukin-2 in a dose-dependent fashion. We conclude that the systemic pre-BMT injection of KGF in recipients of allogeneic T cells up-regulates SP-A, which may contribute to the early antiinflammatory effects of KGF. The protective KGF-mediated SP-A production is abolished in mice given alloreactive T cells plus Cy.

Animals↗

PubMed2000

Quantification of the tip movement of lithotripsy flexible pneumatic probes.

PURPOSE: We developed an optical system to quantify in vitro tip movement of the Lithoclastdouble dagger flexible probe, and correlated various physical parameters of the vibrating probe tip with resultant stone fragmentation. MATERIALS AND METHODS: A noncontact optical measurement system was developed to quantify in vitro tip movement of the Lithoclast flexible probe. This system and an in vitro fragmentation model were used to determine the tip displacement, velocity, impact momentum, impact energy and stone fragmentation of the flexible probe at 5 deflection angles between 0 and 48 degrees, and the 2 pneumatic pressure levels of 2.0 and 2.5 bar. RESULTS: An increase in maximum probe tip displacement, velocity, impact momentum and energy, and stone fragmentation was seen as the pneumatic pressure was increased from 2.0 to 2.5 bar. A progressive decrease in these parameters was demonstrated as the probe tip was deflected, especially at deflection angles greater than 24 degrees. Impact momentum appears to be the physical parameter most closely correlated with stone fragmentation efficiency. CONCLUSIONS: The optical measurement system and in vitro fragmentation model developed allow one to quickly and reliably assess the performance of flexible pneumatic probes in vitro. This system can be used for general bench testing and basic research that can provide critical information for the design of more effective and efficient flexible pneumatic lithotripsy probes.

Calibration↗

PubMed2000

[Side effects after treatment with a-interferon in children with chronic viral hepatitis].

OBJECTIVE: This paper aimed at a long-term observation on side effects of alpha- IFN treatment in children with chronic viral hepatitis. METHODS: A randomized trial of 261 alpha-IFN treated chronic hepatitis children (183 with hepatitis B, 78 with hepatitis C) in comparison with 114 adults was carried out to observe side effect of alpha-IFN treatment 5-6 years in average and 10 years the longest. Mean age of children was 8.7 years, with 203 males and 58 females. RESULTS: Early stage side effects were low to moderate fever and endemic influenza symptoms, which in children were more less than in adults (P < 0.001). Side effects did not relate to viral pathogeny (HB or HC) and pathological changes (< or = G2, > or = G3) in child patient. Slightly poor appetite, slight hair loss, rash and tinnitus would disappear gradually needed no treatment. Serum Bil, Bun, Cr, T3, T4 and TSH were normal in all patients. There was no long-term side effects. CONCLUSIONS: alpha-IFN treatment for viral hepatitis in children is safe.

Adult↗

PubMed2000

[Effect of temperature and food on Spodoptera litura population].

The relationship between temperature and development of Spodoptera litura was simulated by the sine model V(T) = A + B sin(C0 + C1eC3T + C2e-C3T), and the threshold temperature and thermal requirement for its development at different stages were estimated by the direct optimum method. The model for the relationship between temperature and survival rate was fitted by the experimental data. The theoretical optimum temperature for the development of eggs, young instar larvae, old instar larvae and pupae was 26.7, 24.7, 24.9 and 25.8 degrees C, respectively. The life table parameters under different feed conditions (cabbage, lotus, sweet potato, soybean leaves) were estimated by the method of bisexual life table with age-structure. At temperature 25 degrees C, the intrinsic rates of increase under the four different feed conidtions were 0.1836, 0.1719, 0.1778 and 0.1206, respectively.

Animals↗

PubMed2000

[Treatment of ischemic necrosis of femoral head by focal cleaning and bone graft].

OBJECTIVE: To explore a simple and effective method for the treatment of ischemic necrosis of femoral head. METHODS: The anterior region of hip joint was exposed by anterior hip route, a 1.5 cm x 1.0 cm hole was made at the upper region of the femoral neck just below the head. The necrotic bone and sclerotic bone were completely cleaned by drill and curettage until the fresh cancellous bone was exposed. After irrigation, the bone cavity was filled tightly by iliac bone graft until the collapsed femoral head recovered its normal shape. Traction and continuous passive motion(CPM) were performed at the early stage after operation. RESULTS: Twenty cases with 29 femoral head ischemic necrosis (Marcus III to IV stage) were treated by above methods. After 1 to 3 years follow-up, the results were all satisfactory. The pain disappeared, and the functions of the hip joint were all excellent with almost normal walking and squatting. CONCLUSION: The necrotic bone and the sclerotic bone can be removed by this method, thus optimal conditions for the reconstruction of blood supply is obtained. Abundant cancellous bone graft in the residual bone cavity can support the round shape of the femoral head. CPM is very important in the repair of hyaline cartilage and prevention of joint stiffness. It is a simple and effective method in treating femoral head ischemic necrosis.

Adult↗

PubMed2000

[Functional status of p53 and chemosensitivity of colon cancer cell lines].

OBJECTIVE: To study the functional status of tumor suppressor gene p53 in relation to chemotherapeutic sensitivity in colon cancer cell lines. METHODS: With the use of functional assay (FASAY) of p53, the existing p53 status (wt, mt) of 6 colon cancer cell lines was determined. The difference in chemotherapeutic sensitivity of colon cancer cells with wild-type p53 was compared with those with mutated type p53 by MTT method, followed by cytometic analysis of cell cycle. RESULTS: The chemotherapeutic sensitivity of Lovo and LS 174T cancer cell lines with wild-type p53 was 5-10 times higher than that of 4 other cell lines with mutated p53. Selective apoptosis and cell cycle arrest in G1 phase occurred when treated with adriamycin. CONCLUSION: The functional status of p53 in human colon cancer cell lines directly affects their sensitivity to chemotherapeutic agents.

Antibiotics, Antineoplastic↗

PubMed2000

[Seeking behavior of patients with mental disorders and interfering factors].

OBJECTIVE: To approach different help-seeking behavior and its effects on patients with mental illness. METHODS: We investigated the patients first seeking help in psychiatry department, by applying the scale of help-seeking behavior of mental illness. RESULTS: There were significant differences among different mental disorders. 50% patients with mania, 66% with schizophrenia, and about 90% with depression or neurosis first went to general hospital when their illness began. About 80% patients considered their symptoms as normal, temperament, and mood problems. The course of one-third patients was one year, and most patients were treated with traditional herbs, west drugs and tests. Nearly 10% patients with depression, neurosis and schizophrenia spent more then 10 000 yuan before seeking the doctor in psychiatry. CONCLUSION: Now then it is still a main problem for patients with mental disorders in seeking behavior. We suggest that the propaganda of the knowledge of mental health should be paid more attention, especially for the people in community and doctors in general hospital.

Bipolar Disorder↗

PubMed2000

[X-linked thin basement membrane nephropathy was linked with COL4A5 gene].

OBJECTIVE: To genetically analyze 9 thin basement membrane nephropathy (TBMN) pedegrees using microsatellite marker 2B6 and DXS101 closely linked with COL4A5 gene located on chromosome X. METHODS: Genomic DNA was extracted. Highly polymorphic microsatellite markers (2B6 and DXS101) closely linked with COL4A5 gene located on chromosome X were amplified with PCR. Nine TBMN families were analysed. RESULTS: Three of 9 TBMN families were linked with COL4A5 gene on chromosome X (lod score = 2.7, theta = 0.00). CONCLUSION: X-linked TBMN is linked with COL4A5 gene on chromosome X.

Adult↗

PubMed2000

[The recognition of the epidemic area of tsutsugamushi disease on Nan Peng Lie Island in China and the strategy of prevention].

OBJECTIVE: To investigate the region for the epidemic area of tsutsugamushi disease. METHODS: Epidemiological studies, Orientia tsutsugamushi isolation, and preventive measures were used. RESULTS: The region belonged to epidemic area of south subtropical zone. The main host was found Rattus norvegicu. The main biological vector was Leptotrombidium deliens. The seasonal trends of the quantity of Rattus norvegicu and Leptotrombidium deliens were consistent with the incidence change of the disease in the region. Orientia tsutsugamushi has been isolated from Rattus norvegicu and Leptotrombidium deliens. Data showed that Orientia tsutsugamushi isolated strains mainly belongs to Karp. Sero-epidemiological data showed that antibodies of Orientia tsutsugamushi are 100.0% positive in the residents of the region and 4.0% in army men. After taking comprehensive preventive measures, the incidence was descending. CONCLUSION: Nan Peng Lie island was proved an epidemic area of tsutsugamushi disease.

Animals↗

PubMed2000

[An experimental study on cerulenin induced apoptosis of human colonic cancer cells].

OBJECTIVE: To investigate whether cerulenin could induce apoptosis and suppress the proliferation of human colonic cancer cells. METHODS: Cell morphology, microculture tetrazolium assay (MTT), agarose gel electrophoresis and flow cytometry assays were performed to identify the inhibitory effect on cell proliferation and the induction of apoptosis in human colonic cancer cells (LoVo). RESULTS: Cerulenin was able to induce LoVo cells death via apoptosis. Cerulenin also inhibited the proliferation of LoVo cells in vitro and was dose-dependent. Nuclear DNA of apoptotic cells displayed ladder bands characteristic of internucleosomal DNA fragmentation and apoptotic peak. The inhibitory effect of cerulenin on proliferation of LoVo cells was associated with cell cycle arrest from S to G(2)-M phase transition and with induction of apoptosis. In contrast, cerulenin could not affect the proliferation of human fibroblasts in vitro. CONCLUSION: The fatty acid synthase inhibitor, cerulenin, enables to induce cell apoptosis and to suppress the growth of human colonic cancer cells by inhibition of the synthesized fatty acids endogenously in the cancer cells.

Apoptosis↗

PubMed2000

[Cerulenin inhibits growth of human colonic carcinoma in nude mice].

OBJECTIVE: To determine the effects of fatty acid synthase inhibitor, cerulenin, on tumor growth of human colonic carcinoma (LoVo) in nude mice. METHODS: The transplantable colonic carcinoma cell line LoVo model was established in BALB/CA-nu/nu mice by subcutaneous implantation. Cerulenin was administrated by i.p. injection (80 mg/kg, 160 mg/kg each time) for 10 times. 17 days later the mice were killed and tumor size evaluated. RESULTS: The size of tumors in cerulenin-treated group were significantly smaller than in control group and were similar to that of the 5-Fu treated group. Transmission electronic microscopy (TEM) revealed that death of LoVo cells treated by cerulenin was associated with apoptosis characterized by cell shrinkage, condensation and chromosome fragmentation. bcl-2 oncoprotein expression rate was significantly lower in cerulenin-treated group in comparing with the control group. The expression rate of bax was the opposite to that of bcl-2. CONCLUSIONS: Cerulenin effectively suppresses the growth of human colonic carcinoma cells in vivo. The mechanism of cell death may be correlated with apoptosis, and bcl-2 and bax gene may play an important role in regulating cerulenin-induced apoptosis.

Animals↗

PubMed2000

[Protection of beta-carotene and vitamin C on the transformation of human lung fibroblasts cell induced by nickel sesquioxide].

In order to study the protection of beta-carotene and vitamin C against the transformation of human lung fibroblasts (HLF) cell induced by nickel sesquioxide, HLF cells were treated repeatedly by different concentrations of Ni2O3 in vitro. beta-carotene (5.4 mg/L) and vitamin C(1.8 mg/L) were added into the media containing Ni2O3(1.0 mg/L) respectively. The identification of malignancy of the transformation of HLF cell was carried out by the tests of ConA and the growth on semisolid agar culture. The results showed that Ni2O3 could induce the malignant transformation of HLF cell. The transformed cell proliferated rapidly. The transformed colonies exhibited in extensively random orientation and the cells were crossingover. The frequency of transformation showed a dose-response relation at the experimental concentrations. The transformed cell could be agglutinated by lower concentration of ConA and could grow in semisolid agar. The frequencies of transformation of HLF cell exposed to beta-carotene and vitamin C were decreased significantly. The cells could not be agglutinated by ConA and not grow in semisolid agar. It was concluded that Ni2O3 could induce strongly the malignant transformation of HLF cell and might be carcinogenic to human. The protection of beta-carotene and vitamin C on the transformation of HLF cell induced by Ni2O3 was observed. The increase of foods riched in beta-carotene and vitamin C was suggested for workers exposed to nickel.

Antioxidants↗