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Biomedical subjects

H Wu

Publications and source records attributed to H Wu.

At least 199 records · Page 11Linked to original sources
PubMed2001

Kinetics of chromatid break repair in G2-human fibroblasts exposed to low- and high-LET radiations.

The purpose of this study is to determine the kinetics of chromatid break rejoining following exposure to radiations of different quality. Exponentially growing human fibroblast cells AG1522 were irradiated with gamma-rays, energetic carbon (290 MeV/u), silicon (490 MeV/u) and iron (200 MeV/u, 600 MeV/u). Chromosomes were prematurely condensed using calyculin A. Prematurely condensed chromosomes were collected after several post-irradiation incubation times, ranging from 5 to 600 minutes, and the number of chromatid breaks and exchanges in G2 cells were scored. The relative biological effectiveness (RBE) for initial chromatid breaks per unit dose showed LET dependency having a peak at 55 keV/micrometers silicon (2.4) or 80 keV/micrometers carbon particles (2.4) and then decreased with increasing LET. The kinetics of chromatid break rejoining following low- or high-LET irradiation consisted of two exponential components. Chromatid breaks decreased rapidly after exposure, and then continued to decrease at a slower rate. The rejoining kinetics was similar for exposure to each type of radiation, although the rate of unrejoined breaks was higher for high-LET radiation. Chromatid exchanges were also formed quickly.

Cell Line↗
PubMed2001

Comparison of chromosome aberration frequencies in pre- and post-flight astronaut lymphocytes irradiated in vitro with gamma rays.

If radiosensitivity is altered in a microgravity environment, it will affect the accuracy of assessing astronauts' risk from exposure to space radiation. To investigate the effects of space flight on radiosensitivity, we exposed a crewmember's blood to gamma rays at doses ranging from 0 to 3 Gy and analyzed chromosome aberrations in mitotic lymphocytes. The blood samples were collected 10 days prior to an 8-day Shuttle mission, the day the flight returned, and 14 days after the flight. After exposure, lymphocytes were stimulated to grow in media containing phytohaemagglutinin (PHA) and mitotic cells were harvested for chromosome analysis using a fluorescence in situ hybridization (FISH) with whole chromosome specific probes. The dose response of total exchanges showed no changes in the radiosensitivity after the mission.

Astronauts↗
PubMed2001

Anti-human platelet tetraspanin (CD9) monoclonal antibodies induce platelet integrin alpha IIb beta 3 activation in a Fc receptor-independent fashion.

OBJECTIVES: To characterize the activation of platelet integrin alpha IIb beta 3 induced by two anti-human platelet tetraspanin monoclonal antibodies (mAbs), HI117 and SJ9A4, and investigate their potential mechanism of action. METHODS: Using 125I-labeled human fibrinogen (Fg), specific Fg binding to human platelets induced by HI117 and SJ9A4 was measured. RESULTS: HI117 and SJ9A4 (10 micrograms/ml and 20 micrograms/ml) induced specific Fg binding to human platelets, suggesting that the two mAbs evoked activation of platelet integrin alpha IIb beta 3. Further study indicated that HI117 and SJ9A4 induced integrin alpha IIb beta 3 activation independent of platelet Fc-receptors, and that HI117 and SJ9A4-induced integrin alpha IIb beta 3 activation was inhibited by pretreatment of platelets with sphingosine, aspirin, apyrase, and/or PGI2. CONCLUSIONS: Anti-platelet tetraspanin (CD9) mAbs, HI117 and SJ9A4, can induce platelet integrin alpha IIb beta 3 activation independent of Fc-receptors. Three signaling pathways, namely thromboxane, secreted ADP, and cAMP pathways, may be involved in the process, with protein kinase C activation presumably being the common step of the three pathways.

Antibodies, Monoclonal↗
PubMed2001

[Association of single nucleotide polymorphisms in code region of beta2-adrenoceptor gene with hypertension in Chinese population].

OBJECTIVE: To detect single nucleotide polymorphisms(SNPs) existing in code region of beta(2)-adrenoceptor(2-AR) gene and to investigate association of the identified SNPs with essential hypertension in Chinese Han population. METHODS: Beta(2)-AR gene was sequenced with fluorescent labelling automatic sequencing method in unrelated Chinese Han population from Dabie Mountain in Anhui Province. Genotype of the SNPs were typed with PCR-RFLP method. RESULTS: Two SNPs were identified in length of 774bp, at position + 1053 with G-->C substitution and + 1239 with A-->G substitution respectively. The frequency of genotype of the two SNPs complied well with the Hardy-Weinberg equilibrium in normal group. Distribution of genotype AA, GA, GG of the SNPs at locus + 1239 in hypertension group was significantly different from that in normal group (chi(2) = 6.70, df = 2, P < 0.05). No significant difference was observed in distribution of genotypes of the SNPs at locus + 1053 between the two groups. CONCLUSION: These results indicate that the SNPs at locus + 1239 of beta(2)-AR gene is associated with EH. The SNPs at position + 1053 was not linked to hypertension.

Aged↗
PubMed2001

[Apoptotic cells and related factors in ovariectomized rat osteoporosis model].

OBJECTIVE: To investigate the status of apoptosis of osteoblast, osteoclast and the relative factors. METHODS: Apoptotic cells were examined using in situ end labeling technique. Expressions of bcl-2, Fas and transforming growth factor(TGF) beta1 were observed with immunohistochemical method. RESULTS: Positive expression rate (40.5 +/- 5.2)% of apoptosis cells was significantly increased in the osteoblast, but the expression rate of apoptosis cells (8.4 +/- 1.2)% was significantly decreased in the osteoclast of the post-ovariectomy rats than in the sham-operated rats. The expression of Fas was decreased in osteoclast (20.0%) and increased in osteoblast (80.0%) of the post-ovariectomized rats. The expression of TGFbeta1 was significantly decreased in the osteoclast (0) and the osteoblast (20.0%) of the post-ovariectomized rats. The above-mentioned targets in post-ovariectomized rats treated with nylestriol/levonorgestrel were close to those sham-operated rats (P > 0.05). CONCLUSIONS: Bone loss in the post-ovariectomized rats is attributable to the lower level of estrogen so that the apoptosis cells were decreased in osteoclast but were increased in osteoblast. As a result, the process of bone absorption prevails over that of bone formation. Expression of TGFbeta1 depends on stimulation of estrogen. TGFbeta1 may stimulate apoptosis of osteoclast and restrain apoptosis of osteoblast. Fas can induce the apoptosis of osteoclast.

Animals↗
PubMed2001

[Study on anti-inflammatory, analgesic and antipyretic effects of bagmaking tea of sanyaku].

OBJECTIVE: To observe anti-inflammatory, analgesic and antipyretic effects of the Bagmaking Tea of Sanyaku in rats. METHODS: mouse torsion modle induced by glacial acetic acid, mouse auricle swelling model induced by xylene and rat fever model induced by baker yeast were used. RESULTS: Bagmaking Tea of Sanyaku could inhibit mouse torsion action, mouse auricle swelling and rat fever. CONCLUSION: Bagmaking Tea of Sanyaku possessed anti-inflammatory, analgesic and antipyretic effects.

Analgesics↗
PubMed2001

[Role of fibronectin in rat pulmonary fibrosis].

OBJECTIVE: To study the roles of fibronectin (FN) played in rat pulmonary fibrosis. METHODS: The dynamic change of FN was observed in bleomycin-induced rat pulmonary fibrosis using immunohistochemical technique. Northern blot analysis and immunocytochemistry techniques were performed to detect the expression of type I, III procollagen mRNA and their relevant proteins in cultured rat pulmonary fibroblasts (PFbs) after FN treatment. RESULTS: (1) The pulmonary tissue of rats which received bleomycin showed continuously strong positive reaction with anti-FN. (2) The expression of type I, III procollagen mRNA in rat PFbs enhanced at 2 h after FN treatment, and reached their peaks at 6 h, 12 h respectively. The expression of type I, III procollagen proteins detected by immunocytochemistry was also increased after the FN treatment (P < 0.01). Anti-integrin alpha(5) monoclonal antibody could partially inhibit the effect of FN on enhancing the expression of type I, III procollagen in PFbs (P < 0.05). CONCLUSIONS: FN could up-regulate the synthesis of type I, III procollagen mainly by enhancing the transcriptions of procollagen genes.

Animals↗
PubMed2001

[Effect of calcium hydroxide on human pulp cell intracellular calcium ion in vitro].

OBJECTIVE: To investigate the influence of calcium hydroxide to intracellular calcium ion of human pulp cells in vitro. METHODS: The sixth generation of human pulp cells were maintained in RPMI 1640 medium supplemented with Fluo-3 probe and Ca (OH)2 for restimulation. The intracellular calcium ion concentration was detected by laser confocal microscope. RESULTS: The intracellular calcium ion level in Ca (OH)2 pretreatment group increased after Ca (OH)2 stimulation, while it didn't response to Ca (OH)2 stimulus in group without Ca (OH)2, CaCl2 or NaHCO4 pretreatment. CONCLUSION: It is important to pretreat the pulp cells with Ca(OH)2 in order to increase the intracellular calcium.

Calcium↗
PubMed2001

[Mechanical properties of weld area soldered by lasers and structural changes in hot reaction zone].

OBJECTIVE: To analyse and measure the welding depths and strengths of three kinds of welding materials under different laser welding conditions as well as the structural changes of the heat affected zone. METHODS: Under different voltages and pulse duration three kinds of measuring sticks, including Co-Cr alloy, Ni-Cr alloy and pure titanium were welded and their strengths were compared with that of control group. At the same time, the structure of the heat-affected zone was analysed by means of the gold-phase method. RESULTS: The welding depth and strength of Co-Cr alloy were in direct proportion to the setting voltage, with averages of 335MPa (250V) to 573MPa(330V). At the heat-affected zone, the crystal particle was small and the end point of welding by laser bean presented the shape of the mountain peak and the interval of finger shape. The center of measuring sticks had a black zone with the circle shape. The setting voltage was in direct proportion to the welding depth of pure titanium and in inverse proportion to the welding strength with averages of 221MPa(250V) to 154MPa (330V). The crystal particle in the heat affected zone grew large and the solid phase expanded, the interval of the crystal oxidised, and the structure showed honeycomb changes. CONCLUSION: The laser welding is favourable to the welding properties of Co-Cr and Ni-Cr alloys, but its effect on the welding properties of pure titanium needs further discussion.

Biomechanical Phenomena↗
PubMed2001

[Expression of matrix metalloproteinase-2 in rat pulmonary fibrosis].

OBJECTIVE: To study the role of matrix metalloproteinase-2 (MMP(2)) in rat pulmonary fibrosis. METHODS: (1) Dynamic changes of MMP(2) expression were observed in bleomycin-induced rat pulmonary fibrosis by use of immunohistochemical technique. (2) RT-PCR was carried out to show the dynamic changes of MMP(2) mRNA expression of isolated pulmonary fibroblasts (PFbs) during rat pulmonary fibrosis. (3) Northern blot analysis and immunocyto chemistry techniques were performed to detect the expression of MMP(2) mRNA and their relevant protein in cultured rat PFbs after treatment with transforming growth factor 1 (TGF beta(1)). RESULTS: (1) On day 1-7th after receiving bleomycin, the infiltrated pulmonary macrophages and septa mesenchymal cells showed positive reaction with anti-MMP(2) and an increase in number. After 14 days and on 28 th of bleomycin treatment, the number of positive staining macrophages and mesenchymal cells were decreased respectively. (2) The gene expression of MMP(2) mRNA of PFbs were enhanced after bleomycin treatment from the Day 1 and decreased by Day 28. (3) The expression of MMP(2) mRNA and their relevant protein were enhanced in rat PFbs after TGF beta(1) treatment. CONCLUSIONS: Over expression of MMP(2) in pulmonary tissue may be an important factor in the initiation of pulmonary fibrogenesis.

Animals↗
PubMed2001

[Effects of pyracantha fortuneana extract on blood coagulation].

OBJECTIVE: To study the effect of the Pyracantha fortuneana extract and its defferent polar fractions on blood coagulation. METHODS AND RESULTS: The Pyracantha fortuneana extract could noticeably shorten the coagulation time of glass slide in mice (P < 0.05) after oral administration, and also shorten the recalcification time and prothrombin time in vitro (P < 0.01, P < 0.05), while in three polar fractions of the extract, the effects of the chloroform phase that could shorten the coagulation time of glass slide in mice(P < 0.01) after oral administration, and also shorten the recalcification time and prothrombin time in vitro (P < 0.01) are more noticeable than that of the acetic ether phase (P < 0.01, P < 0.05). The petroleum ether phase has no above-mentioned effect (P > 0.05). CONCLUSION: The Pyracantha fortuneana extract can reduce the blood coagulation. Both the chloroform phase and the acetic ether phase of the extract have activity of blood coagulation, but the petroleum ether phase does not.

Animals↗
PubMed2001

[Discovery of natural variant strain of HIV1 in env gene C2-V3 encoded PND of membrane protein].

OBJECTIVE: To sequence and analyze the env gene C2-V3 region of proviral genome from a HIV1 isolate(WWBH7) which was obtained from Huadong Area in China. METHODS: The env gene C2-V3 DNA fragment was amplified by nested-primer PCR with genome DNA of eripheral blood mononuclear cells from a confirmed HIV1 infected individual as a template. The amplified DNA fragment was inserted into pGEM-T vector. The recombinant plasmid was confirmed by restriction enzyme analysis. The inserted DNA fragment was sequenced by ABI737 autosequencer and analyzed by PROSIS software. RESULTS: The HIV1 strain was the derivatives of HIV1 B subtype. But there was mutation of 192 bp fragment repeated insertion at env C2-V3 region of the HIV1 strain compared with standard HIV1 B subtype such as SF2 strain. The mutation brought about a double V3 region in gene encoded PND (principal neutralizing domains). The DNA sequence was registered in GenBank (AF220245). CONCLUSIONS: This was a natural mutated variant strain of HIV1 whose genome showed a 192 bp repeated insertion at C2-V3 region of env gene encoded PND of membrane protein.

Amino Acid Sequence↗
PubMed2001

[Cloning, sequencing of beagle E-selectin genomic DNA and comparison of it with other species].

OBJECTIVE: Selectins are a group of members of Cell Adhesion Molecular family; they play very important roles in inflammation and neovascularization. The aim of this study is to clone, sequence Beagle E-selectin genomic DNA and make homogeneous analyses to compare it with those of other animals. METHODS: Twelve fragments of genomic DNA of Beagle E-selectin were obtained by PCR, and the 12 fragments were cloned in T-vector. At last, the genomic DNA sequences of Beagle E-selectin were obtained through gene sequencing, assembling and base calling, and the gene structure was analyzed. RESULTS: The sequence of Beagle E-selectin genomic DNA that contained the whole open reading box was acgured. The results of homogeneous analyses showed a great extent of E-selectin gene homology among human, porcine and dog. CONCLUSION: The demonstration of a large extent of the gene homology has substantiated in this connection the important roles of E-selectin in transplantation immunity and neoplasm development.

Animals↗
PubMed2001

[Nutritional status assessment of patients with oral maxillofacial cancers].

OBJECTIVE: The objective of the study is to evaluate the nutritional status of patients with oral maxillofacial cancer. METHODS: The nutritional status was evaluated using seven easily determined variables and multi-factor nutritional index in 50 hospitalized patients with oral maxillofacial cancer from 1990 to 1992. RESULTS: Fifty-six percent of patients had protein-energy malnutrition. The high incidence of protein-energy malnutrition was found in those patients without adequate dietary intake. CONCLUSION: Patients with oral maxillofacial cancer usually have protein-energy malnutrition. The reason is that the patients always have an inadequate dietary intake.

Adolescent↗
PubMed2001

[An experimental study on the blood vessel sclerosing therapeutic agents for cavernous hemangiomas].

OBJECTIVE: This study was designed to test what are the suitable drugs for sclerotherapy and investigate the formation mechanism of cavernous hemangiomas. METHODS: A total of 84 rabbits were selected for this study, and divided into 6 groups, including one control group and five experimental groups. We selected auricular veins of rabbits as the location of injection. The rabbits of the control were injected with physiological saline, and the rabbits of the experimental groups were injected respectively with various drugs, including 5% sodium morrhuate, 10% alum, pinyungmycin, leurocristine and the combination of pinyungmycin and dexamethasone. Histopathological changes were analyzed after 3, 7, 14, 21, 28, 35 days of sclerotherapy. RESULTS: According to histopathological changes of tissue, 5% sodium morrhuate, 10% alum, and the combination of pinyungmycin and dexamethasone produced better eutherapeutic effects, when comparing with other methods. However, 5% sodium morrhuate caused tissue necrosis of the injection site. CONCLUSION: The combined therapy of pinyungmycin and dexamethasone produced excellent sclerotic effects. Whatever drugs causing serious damage of HVEC may contribute to the therapy for cavernous hemangiomas.

Animals↗
PubMed2001

[Development of a gas chromatographic column system for the on-line analysis of trace tetrahydrofuran in hexane].

A gas chromatographic system using home-made 7 microns thick cross-linked dimethylpolysiloxane columns for the on-line analysis of trace tetrahydrofuran in hexane in a rubber production facility was developed. The experimental parameters of the column system, including the temperature, flow rate as well as the back-flushing and heart-cutting program were investigated. The total column-switching program was suggested. The system has been successfully operated for more than one year with good resolution, stability and precision (RSD < 5%) in analyzing trace tetrahydrofuran (0-250 x 10(-6), V/V) for industrial process control in the rubber production facility.

Chromatography, Gas↗
PubMed2001

[Primary restoration for congenital malformation of external and middle ear].

OBJECTIVE: To promote the hearing, improve the appearance, shorten the therapeutic course in congenital malformation of external and middle ear, the program of primary restoration has been designed. METHOD: Under general or local anaesthesia a Z-shaped incision is made in skin. After turn up the flap A (defective ear) and flap B(retroauricular skin), a periosteal flap C with pedicle in front is made and elevated from mastoid. Then made frameworklize on mastoid and perform tympanoplasty. Once the myringograft is put properly the flap C is turn into the mastoidal cavity to serve as the lining of anterior wall. Flap A is sutured with the edge of retroauricular incision to serve as the lower part of new auricle. Then use the flap B to wrap a siliceous frame to make the upper part of new auricle. Finally, the naked walls of mastoidal cavity are lined with free skin graft and the cavity is packed with vaseline gauze for two weeks. RESULT: Two cases of congenital malformation of external and middle ear were treated with the procedure mentioned above and were followed up for one and 3 years respectively. Both effects of shape and hearing were good. CONCLUSION: The primary restoration for congenital malformation of external and middle ear designed by the authors is an excellent method worthy to be recommended.

Adolescent↗