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H Qiang

Publications and source records attributed to H Qiang.

16 recordsLinked to original sources
PubMed2001

Serum cholesteryl ester transfer protein concentrations in healthy Chinese subjects and cardio-cerebrovascular disease patients.

Serum cholesteryl ester transfer protein (CETP) concentration was measured in 1128 healthy Chinese subjects using a "sandwich" enzyme immunoassay and was 1.84 +/- 1.55 mg/l (mean +/- S.D.). The frequency distribution of CETP in healthy subjects was markedly skewed towards low concentrations. The CETP concentration in females was significantly higher than that in males (2.40 +/- 1.65 mg/l vs. 1.49 +/- 1.37 mg/l, P < 0.001). There was a weak inverse correlation between the CETP concentration and age (r = -0.19, P < 0.001). The CETP concentrations were significantly higher in 117 myocardial infarction (MI) survivors and 110 stroke patients than that in 335 healthy, age-matched males (1.98 +/- 1.68 173 +/- 1.45, and 1.40 +/- 1.37 mg/l respectively, P < 0.01), while no relation was found between CETP concentration and lipids concentration in MI, stroke and healthy group.

Cardiovascular Diseases↗
PubMed2001

Relationship between endogenous estrogen concentrations and serum cholesteryl ester transfer protein concentrations in Chinese women.

BACKGROUND: CETP plays an important role in HDL metabolism and in the reverse cholesterol transport pathway. METHODS: The relationship between the changes of endogenous estrogen and the concentration of cholesteryl ester transfer protein (CETP) in the serum of Chinese women was investigated. Serum concentrations of estradiol (E(2)), follicle-stimulating hormone (FSH), CETP and lipid profile were determined in 196 Chinese women (52 premenopausal with ages ranging from 18 to 40 years, 57 perimenopausal from 41 to 60 years, and 87 postmenopausal from 61 to 81 years). RESULTS: Serum CETP concentration was significantly lower in postmenopausal women compared with those in perimenopausal and premenopausal women (1.39+/-1.06, 2.36+/-1.50 and 2.31+/-1.25 mg/l, respectively, P<0.0001). Even in the women around the menopausal, CETP concentration in postmenopause was significantly lower than that in premenopause (1.93+/-1.33 vs. 3.42+/-1.35 mg/l, P<0.01). In addition, CETP concentration had a highly positive correlation with serum concentration of E(2) (r=0.243, P<0.001), while negative correlation of CETP concentration with serum concentration of FSH was found (r=-0.273, P<0.001). CONCLUSIONS: Estrogen may affect the concentration of CETP.

Adolescent↗
PubMed2001

Inhibitory effects of rosa roxburghii tratt juice on in vitro oxidative modification of low density lipoprotein and on the macrophage growth and cellular cholesteryl ester accumulation induced by oxidized low density lipoprotein.

BACKGROUND: Rosa roxburghii tratt juice (RRTJ) administration has been shown to significantly ameliorate atherosclerotic diseases in cholesterol-fed animals. However, the mechanism for the antiatherogenic effect of RRTJ is not clear. METHODS: We investigated the effects of RRTJ on in vitro oxidative modification of LDL and on LDL-induced macrophage growth and cellular cholesteryl ester (CE) accumulation. The effects of RRTJ on LDL oxidative modification were assessed by relative electrophoretic migration, thiobarbituric acid-reactive substance (TBARS) content, and the formation of conjugated dienes. The inhibition of RRTJ on oxidized LDL (Ox-LDL)-induced murine peritoneal macrophage growth was evaluated by a cell-counting assay and an MTT assay. The effect of RRTJ on Ox-LDL-induced cellular CE accumulation was examined after macrophages were incubated with Ox-LDL in the presence of RRTJ. To clarify the mechanism of the inhibitory effect of RRTJ on Ox-LDL-induced CE accumulation in macrophages, its capacity for cholesterol efflux from macrophage-derived foam cells were examined. RESULTS: We showed that RRTJ significantly reduced LDL oxidative susceptibility. In addition, RRTJ effectively suppressed Ox-LDL-induced macrophage growth and especially Ox-LDL-induced CE accumulation in murine peritoneal macrophages by promoting cellular cholesterol efflux. CONCLUSION: These results indicated that RRTJ exerted its antiatherogenic effects largely due to its ability to inhibit the oxidative modification of LDL and to suppress the formation of foam cells.

Animals↗
PubMed2001

Mutagenesis of the rapamycin producer Streptomyces hygroscopicus FC904.

Rapamycin (RPM) is produced by Streptomyces hygroscopicus FC904 isolated from soil in Fuzhou, China. It is a triene macrolide antibiotic with potential application as an immunosuppressant and drug for human gene therapy. In an attempt to improve rapamycin production, mutation and screening of the parent culture have been carried out. Thousands of survivors were obtained after mutagenesis by NTG (3 mg/ml) and UV (30 W, 15 cm, 30 seconds) of spore suspensions. None showed improved production of RPM. We determined the susceptibility to antibiotics of S. hygroscopicus FC904 by two fold dilutions of antibiotics in oatmeal agar plates. It was found that the strain was resistant to penicillin, erythromycin, RPM, tetracycline and chloramphenicol, but susceptible to mitomycin C (MIC, 10 microg/ml) and aminoglycosides such as gentamicin (MIC, 0.1 microg/ml), kanamycin (MIC, 0.1 microg/ml) and streptomycin (MIC, 0.3 microg/ml). Protoplasts of strain FC904 were prepared after finding the best conditions for their formation. They were treated with gentamicin, erythromycin, mitomycin C and NTG. Surprisingly, gentamicin was especially effective for obtaining higher RPM-producing mutants. Mutant C14 was selected by exposing the protoplasts of the parent strain FC904 to 1 microg/ml of gentamicin at 28 degrees C for 2 hours. A higher RPM-producing mutant (C14-1) was obtained from the protoplasts of mutant C14 treated with gentamicin, and its titer was 60% higher than that of the parent strain FC904 by HPLC analysis. Another improved mutant (C14-2) was obtained from the spores of mutant C 14 treated with 1 microg/ml of gentamicin plus 2 mg/ml of NTG at 28 degrees C for 2 hours. Mutant C14-2 had a titer 124% higher than FC904. The possible mechanism for the effect of gentamicin by using protoplasts or spore suspensions will be discussed, i.e. the possibility of gentamicin being a mutagen or a selective agent.

Anti-Bacterial Agents↗
PubMed2000

Reciprocal interactions between perisynaptic Schwann cells and regenerating nerve terminals at the frog neuromuscular junction.

The perisynaptic Schwann cell (PSC) has gained recent attention with respect to its roles in synaptic function, remodeling, and regeneration at the vertebrate neuromuscular junction (NMJ). Here we test the hypothesis that, following nerve injury, processes extended by PSCs guide regenerating nerve terminals (NTs) in vivo, and that the extension of sprouts by PSCs is triggered by the arrival of regenerating NTs. Frog NMJs were double-stained with a fluorescent dye, FM4-64, for NTs, and fluorescein isothiocyanate (FITC)-tagged peanut agglutinin (PNA) for PSCs. Identified NMJs were imaged in vivo repeatedly for several months after nerve injury. PSCs sprouted profusely beginning 3-4 weeks after nerve transection and, as reinnervation progressed, regenerating NTs closely followed the preceding PSC sprouts, which could extend tens to hundreds of microns beyond the original synaptic site. The pattern of reinnervation was dictated by PSC sprouts, which could form novel routes joining neighboring junctions or develop into new myelinated axonal pathways. In contrast to mammals, profuse PSC sprouting in frog muscles was not seen in response to axotomy alone, and did not occur at chronically denervated NMJs. Instead, sprouting coincided with the arrival of regenerating NTs. Immunofluorescent staining revealed that in muscle undergoing reinnervation 4 weeks after axotomy, 91% of NMJs bore PSC sprouts, compared to only 6% of NMJs in muscle that was chronically denervated for 4 weeks. These results suggest that reciprocal interactions between regenerating NTs and PSCs govern the process of reinnervation at frog NMJs: regenerating NTs induce PSCs to sprout, and PSC sprouts, in turn, lead and guide the elaboration of NTs.

Animals↗
PubMed2000

The role of perisynaptic Schwann cells in development of neuromuscular junctions in the frog (Xenopus laevis).

Fluorescence microscopy was used to study the behavior of perisynaptic Schwann cells (PSCs) in relation to motor nerve terminals and postsynaptic clusters of acetylcholine receptors, during the development of the neuromuscular junction (NMJ) in the frog Xenopus laevis. Pectoral (supracoracoideus) muscles were labeled with monoclonal antibody 2A12 for Schwann cells, the dye FM4-64 for nerve terminals (NTs), alpha-bungarotoxin for acetylcholine receptors (AChRs), and Hoechst 33258 for cellular nuclei, in animals from tadpole stage 57 to fully grown adults. When muscle fibers first appeared in stage 57, NMJs consisted of tightly apposed NTs and AChRs and were only partially covered with PSCs or their processes. Within a few stages, PSCs fully occupied and overgrew the NMJs, extending fine sprouts between a few micrometers and hundreds of micrometers beyond the borders of the junction. Sprouts of PSCs were most abundant during the time when secondary myogenesis, synaptogenesis, and synaptic growth occurred at their highest rates. PSCs were recruited to NMJs during synaptic growth, at rates between 1.3 PSCs/100 microm junctional length early on and 0.4 PSCs/100 microm later. Shortly after metamorphosis, PSC sprouts disappeared and NMJs acquired the adult appearance, in which PSCs, NTs, and AChRs were mostly congruent. The results suggest that, although PSCs may not be required for initial nerve-muscle contacts, PSCs sprouts lead synaptic growth and play a role in the extension and maturation of developing NMJs.

Age Factors↗
PubMed2000

Construction and analysis of cDNA library of Necator americanus third stage larvae.

OBJECTIVE: To obtain the genetic information on Necator americanus and to search for the purpose genes. METHODS: mRNA was isolated from the third stage larvae of Necator americanus maintained in hamsters. Double strand cDNA was synthesized and ligated to lambda ZAPII vector to construct the cDNA library. Expressed sequence tages (ESTs) were obtained by single pass sequencing of randomly isolated cDNA clones from the established library. RESULTS: A cDNA library of N. americanus was successfully constructed with high recombinant efficiency. The titer of unamplified library was 1 x 10(7). The insert size was about 750-3,000 bp. Of 11 ESTs obtained from the library, 7 have a significant homology with certain functional genes. CONCLUSION: A high quality and high representative cDNA library of N. americanus was constructed at the first time and some functional genes were identified from the library by ESTs.

Animals↗
PubMed1999

Enzyme-linked immunoelectrotransfer blotting analysis of human serologic responses to infective hookworm larval antigen.

OBJECTIVE: To explore the possibility of using specific antigens for immunodiagnosis of hookworm disease in endemic area. METHOD: Infective third-stage larvae of the canine hookworm, Ancylostoma caninum (A. caninum), were prepared as the source of antigen. Enzyme-linked immunoelectrotransfer blotting (EITB) was employed as an immunodiagnostic method. RESULTS: Two immunodominant bands of hookworm antigens (42 kDa and 55 kDa) were recognized by the sera of hookworm-infected patients (serum dilution 1:200; antigen centrifuged at 36,000 r/m for 20 minutes, but not by sera from negative controls. CONCLUSION: The 42 kDa and 55 kDa A. caninum antigens might be the specific antigens that could be used for immunodiagnosis of hookworm disease in endemic area.

Ancylostoma↗
PubMed1999

Length of protection by murine vaccination with living infective third-stage hookworm larvae.

OBJECTIVE: To determine the length of protection by murine immunization with living third-stage hookworm larvae (L3) as measured by reduction in worm burden and host serologic antibody responses. METHODS: Outbred male (Kunming strain) mice were immunized subcutaneously with 500 L3 once every 2 weeks for a total of immunization for 3 times, and then challenged orally with 1000 L3 for 1 to 8 weeks after the final immunization. Host protective immunity was determined both by the reduction in worm burden as measured by the number of L3 recovered from murine lungs 48-hour post-challenge, as well as by measurement of circulating antibodies. Histopathological responses were also examined. Non-immunized mice served as negative controls. RESULTS: The protection by L3 immunization declined over time. One or 2 weeks after the final immunization, worm burdens were reduced 72% and 77.5% after challenge respectively. In contrast, only 37% reduction in worm burden was observed when the L3 challenge was delayed by 4 weeks and protection was almost entirely lost when there was an 8 week delay between the time of final immunization and challenge. The reduced level of protection over time partially correlated with diminishing L3-specific antibody responses. Host inflammation in the lungs of immunized mice also diminished. CONCLUSION: The protection afforded by living L3 immunization is maximal for the first two weeks after immunization, but then declines significantly over the ensuing weeks.

Ancylostoma↗
PubMed1998

Perisynaptic Schwann cells at neuromuscular junctions revealed by a novel monoclonal antibody.

This study aimed to generate a probe for perisynaptic Schwann cells (PSCs) to investigate the emerging role of these synapse-associated glial cells in the formation and maintenance of the neuromuscular junction (NMJ). We have obtained a novel monoclonal antibody, 2A12, which labels the external surface of PSC membranes at the frog NMJ. The antibody reveals PSC fine processes or "fingers" that are interposed between nerve terminal and muscle membrane, interdigitating with bands of acetylcholine receptors. This antibody also labels PSCs at the avian neuromuscular junction and recognizes a 200 kDa protein in Torpedo electric organs. In frog muscles, axotomy induces sprouting of PSC processes beyond clusters of acetylcholine receptors and acetylcholinesterase at denervated junctional branches. PSC branches often extend across several muscle fibers. At some junctions, PSC sprouts join the tips of neighboring branches. The average length of PSC sprouts is approximately 156 microm at 3-week denervated NMJs. PSC sprouting is accompanied by a significant increase in the number of Schwann cell bodies per NMJ. Following nerve regeneration, nerve terminals reinnervate the junction along the PSC processes. In vivo observations of normal frog muscles also show PSC processes longer than nerve terminals at some junctional branches. The results suggest that nerve injury induces profuse PSC sprouting that may play a role in guiding nerve terminal regeneration at frog NMJs. In addition, antibody 2A12 reveals the fine morphology of PSCs in relation to other synaptic elements and is a useful probe in elucidating the function of these synapse-associated glial cells in vivo.

Animals↗
PubMed1998

Protective immunity in mice elicited by living infective third-stage hookworm larvae (Shanghai strain of Ancylostoma caninum).

OBJECTIVE: To elucidate the mechanisms of protective immunity in mice elicited by living hookworm (Ancylostoma caninum third-stage infective larvae (L3). METHODS: The number of migrating infective larvae recovered from the lungs was used as an endpoint for vaccine immunity. The timing of maximal L3 lung entry was determined by counting the number of lung larvae at several time points after infection with 500 or 1000 L3. Mice were immunized either orally or subcutaneously with 500 L3, followed by two boosts of L3 once every two weeks. The immunized mice were challenged orally with 500 L3 one week after the final boost. To evaluate the protective immunity, the number of L3 recovered from the lungs of the immunized mice during the time of maximal larval entry was compared with that of controls. Host immunity was also evaluated by comparing circulating anti-L3 antibodies between immunized and controlled mice, using both enzyme immunoassays and immunoblotting techniques, and by lung histopathology. RESULTS: The peak time of larval entry into the lungs occurred 48 hours after infection. Mice immunized either orally or subcutaneously with L3 exhibited a marked reduction (90.2% and 86.2% respectively) in the number of recovered lung larvae in comparison to controls (P < 0.01). The protection might be associated with circulating anti-L3 antibodies, including antibodies directed against 132-200 kDa L3 antigens, as well as three major antigens ranging from 28 to 51 kDa. Larvae migrating through the lungs of vaccinated mice showed cuticular damages accompanied with host-inflammatory cell invasion. CONCLUSIONS: Immunization with living L3 protects mice against lung invasion after challenged with hookworm infection. Vaccine immunity is associated with circulating antibodies against L3 antigens and lung inflammatory responses. The mouse model is potentially useful for developing a hookworm vaccine.

Ancylostoma↗
PubMed1994

Effect of albendazole on the larvae and eggs of Necator americanus in golden hamster.

When golden hamsters infected with adult Necator americanus were treated ig with albendazole(Alb) 75 or 150 mg/kg, the efficacy rates were 83.8% and 100%, respectively. Three days before treatment, the mean numbers of larvae recorded from the incubation of feces from 2 treated groups were 29,716 +/- 3,299 and 28,256 +/- 118 per gram of feces, while in the control group, it was 8,828 +/- 2,659. Within 3 days after treatment, no larva was detected in the 2 treated groups, but in the control group the mean larva number was 9,066 +/- 7,416. Furthermore, in 2 treated groups none or only a few degenerated eggs could be found using saturated saline solution method. when infected golden hamsters were treated ig with Alb at a single dose of 150 or 300 mg/kg on day 3, 7 or 14 after infection with the third stage larvae, the egg positive rates in the feces were 0-9.1%, while the worm reduction rates were 96.8-100%.

Albendazole↗
PubMed1993

Hole lifetimes in

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Journal Article↗