Search PubMed⌕ Search

Biomedical subjects

Hui Liu

Publications and source records attributed to Hui Liu.

At least 181 records · Page 10Linked to original sources
PubMed2003

Emerging HIV-1 epidemic in China in men who have sex with men.

China is currently undergoing a serious HIV-1 epidemic in intravenous drug users, sex workers, and former plasma donors. Little is known, however, about HIV-1 risk in Chinese men who have sex with men. In this study of seroprevalence in such men in Beijing, we recorded 15 (3.1%, 95% CI 1.8-5.1) of 481 men infected with HIV-1. Overall, 238 (49%) of participants reported unprotected anal intercourse during the previous 6 months. HIV-1 seropositivity was independently associated with being older than 39 years and having had more than 20 male sexual partners. Most men older than 39 years had been married. Our findings suggest the potential for spread of HIV-1 between men who have sex with men and to their heterosexual partners.

Adolescent↗
PubMed2003

p250GAP, a neural RhoGAP protein, is associated with and phosphorylated by Fyn.

Fyn is a member of the Src-family protein tyrosine kinases and plays important roles in both neurons and oligodendrocytes. Here we report association of Fyn with p250GAP, a RhoGAP protein that is expressed predominantly in brain. p250GAP interacts with Fyn both in vitro and in vivo. p250GAP is tyrosine phosphorylated by Fyn when co-expressed in HEK293T cells. This phosphorylation appears to enhance the interaction between p250GAP and Fyn. Furthermore, the level of tyrosine phosphorylation of p250GAP increases upon differentiation of the oligodendrocyte cell line CG4. Given that Fyn activity is up-regulated during oligodendrocyte maturation, the results argue that p250GAP is phosphorylated by Fyn in oligodendrocytes. Tyrosine phosphorylation of p250GAP by Fyn would regulate its RhoGAP activity, subcellular localization, or interactions with other proteins, leading to morphological and phenotypic changes of oligodendrocytes.

Cell Differentiation↗
PubMed2003

Asymmetric transfer hydrogenation of prochiral ketones in aqueous media with new water-soluble chiral vicinal diamine as ligand.

[reaction: see text] An easily accessible water-soluble chiral o-sulfonated 1,2-diphenylethlenediamine 2 and its mono-N-tosylated derivative 3 were synthesized for the first time. The ruthenium-complex-catalyzed reduction of prochiral ketones in aqueous media has been examined by using 3 as ligand and sodium formate as the source of hydrogen. The asymmetric transfer hydrogenation of omega-bromo acetophenones was achieved, in which only formate displacement occurred when formic acid/triethylamine azeotrope was used as the hydrogen donor.

Journal Article↗
PubMed2003

Cold ischemic injury, aortic allograft vasculopathy, and pro-inflammatory cytokine expression.

BACKGROUND: The aim of this study was to understand the role of ischemic preservation injury and pro-inflammatory cytokine expression in the progression of allograft vasculopathy. METHODS: Using the rat aortic transplant model, grafts were stored at 4 degrees C for either 1 or 24 h. Graft vasculopathy was assessed at 4 and 8 weeks after transplantation. Intra-graft cytokine expression was measured at days 1, 3 and, 7 after transplantation. RESULTS: At 4 weeks, intimal hyperplasia of allografts was greater than isografts (P<0.05). At 8 weeks, all groups had an increase in graft vascular disease compared to the 4-week groups (P<0.05). Allografts preserved for 24 h displayed a greater degree of vessel-wall reaction than both isograft groups and allografts stored for 1 h (P<0.05). An increased expression of the cytokines, TNF-alpha, TGF-beta, IL-2, INF-gamma, IL-1, and IL-6 was noted in the allografts stored for 24 h compared to similarly treated isografts (P<0.05). CONCLUSIONS: Prolonged ischemic preservation injury induced vascular disease in both isografts and allografts. The vessel wall reaction increased over time and was greater in allografts than isografts. The enhanced expression of T cell- and macrophage associated cytokines in allografts compared to isografts, suggested that early pro-inflammatory cytokine expression played an important role in progression of allograft vasculopathy.

Animals↗
PubMed2003

Expression, purification and functional characterization of a recombinant scorpion venom peptide BmTXKbeta.

BmTXKbeta, a scorpion toxin isolated from the Chinese scorpion Buthus martensii Karsch (BmK), was expressed as a GST fusion protein in BL21 (DE3) strain. The recombinant GST-BmTXKbeta protein was purified by affinity chromatography. When treated with enterokinase, the GST-BmTXKbeta fusion protein released an approximate 6.5kDa protein which was the expected size for correctly processed. About 2mg purified recombinant BmTXKbeta protein (rBmTXKbeta) was produced from 1l bacterial culture, using this expression and purification system. The function of rBmTXKbeta was studied on the rabbit atrial myocyte by whole-cell patch clamp technique. The results showed that rBmTXKbeta inhibited the transient outward current (I(to)) of rabbit atrial myocyte with recovery after washout and the inhibition was concentration-dependent. The rBmTXKbeta prolonged the action potential duration of rabbit atrial myocyte in a concentration-dependent manner, whereas it did not affect the action potential amplitude.

Action Potentials↗
PubMed2003

A novel assay system implicates PtdIns(3,4)P(2), PtdIns(3)P, and PKC delta in intracellular production of reactive oxygen species by the NADPH oxidase.

Activated neutrophils assemble an NADPH oxidase enzyme complex to produce superoxide for microbial killing. Much of the initial oxidase assembly occurs on intracellular granules, followed by movement of the oxidase to phagolysosomes and the plasma membrane. We have developed a novel assay system using Streptolysin-O permeabilized neutrophils that recapitulates the initial intracellular activation process while maintaining the ultrastructural features of this granulocytic cell type. Using this system, we biochemically dissect molecular events and signaling pathways involved in NADPH oxidase assembly and demonstrate specific roles for PKC delta, PI(3,4)P(2)/PI(3,4,5)P(3), and PI(3)P in the PMA-dependent intracellular activation process. This system should be of great utility for the study of cell signaling events that regulate the intracellular production of reactive oxygen species by neutrophils.

Adenosine Triphosphate↗
PubMed2003

The KRAB domain of zinc finger gene ZNF268: a potential transcriptional repressor.

Nearly one-third of Krupple-type C2H2 zinc finger proteins have a krupple-associated box (KRAB) domain, which may act as a transcriptional repressor. ZNF268, which was novelty isolated from early human embryo, is a typical krupple-type C2H2 zinc finger protein with a conserved KRAB domain. In this report, the KRAB domain of ZNF268 is identified to localize in the nucleus and has transcriptional repressor activity.

Amino Acid Sequence↗
PubMed2003

Metaphase II nuclei generated by germinal vesicle transfer in mouse oocytes support embryonic development to term.

BACKGROUND: Cytoplasmic defects are thought to cause aneuploidies in oocytes and embryos and oocyte 'reconstruction' by germinal vesicle (GV) transfer may circumvent such defects. In mice 'reconstructed' oocytes undergo meiosis and fertilize normally, but early embryonic development is compromised if their ooplasm matured in vitro. This study employs sequential MII spindle and/or pronucleus (PN) transfer to assess the embryonic potential of MII nuclei that form following GV transfer. METHODS AND RESULTS: Mouse embryos generated by these procedures were transferred to the oviducts of pseudopregnant mice to monitor pregnancy outcome. Following GV transfer, the resultant metaphase II (MII) nuclei were activated either in situ or transferred and activated in ooplasts from in-vivo matured oocytes. When exchanged with the female PN of a fertilized zygote, only the PNs that developed in in-vivo matured ooplasts generated live offspring. Viable offspring also resulted when MII nuclei were transferred to in-vivo matured ooplasts and fertilized by insemination with sperm or by artificial activation and male PN transfer. Significantly, the offspring displayed normal fertility as adults. CONCLUSION: This report of live births following GV transfer in mice illustrates the importance of the maturational history of the ooplasm at PN formation for normal embryonic and fetal development.

Animals↗
PubMed2003

RNA and DNA, which contain two GGAGG segments connected with UUUU or TTTT sequences, form entirely different quadruplex structures.

We determined solution structure of d(GGAGGTTTTGGAGG) (D14) in the presence of Na+ ions by NMR. Two molecules of D14 form a quadruplex strucure with parallel and antiparallel strand alignments. The quadruplex is formed by four helical GGAGG segments and two diagonal TTTT loops at the top and bottom of the helix. This quadruplex structure is entirely different from that of r(GGAGGUUUUGGAGG) (R14), which has been previously determined by NMR. In the case of RNA, R14 forms an intra-strand parallel quadruplex with a UUUU loop a t lateral position ofthe helix and two such molecules form a dimer by stacking. The factors determining the type of RNA and DNA quadruplexes are discussed.

Base Sequence↗
PubMed2003

Potential utility of various protease inhibitors for improving the intestinal absorption of insulin in rats.

The aim of the investigation was to study the effects of protease inhibitors on the absorption of insulin in-situ from closed small and large intestinal loops in rats and to investigate the mechanism of various protease inhibitors in different intestinal loops. The intestinal absorption of insulin was evaluated by its hypoglycaemic effect and serum insulin level in the presence or absence of luminal contents. No marked hypoglycaemic effect was observed after administration of insulin alone in either region in the presence or absence of luminal contents. A significant hypoglycaemic effect of insulin was obtained in the large intestinal loop in the presence or absence of luminal contents when insulin was co-administered with bacitracin (20, 30 mM), sodium glycocholate (20, 40 mM), bestatin (29 mM), leupeptin (21 mM) and cystatin (0.8 mM). In contrast, there was no hypoglycaemic effect in the small intestinal loop in the presence of luminal contents following small intestinal co-administration of insulin with these protease inhibitors. The effectiveness of protease inhibitors was susceptible to their categories, concentrations and activity of proteolytic enzymes in different regions. The degree of improving insulin absorption in intestine was in the order of leupeptin>sodium glycocholate>bacitracin>bestatin>cystatin. At the same time, the percutaneous enhancement effect was observed in the presence of either sodium glycocholate or bacitracin. These results suggest that protease inhibitors could increase the insulin efficacy more effectively in the large intestine than in the small intestine.

Animals↗
PubMed2003

[Research and development on the dynamic system for detecting the force of acupuncture needle during the acupuncture process in the clinical practice of traditional Chinese medicine].

Manipulations are essential to the acupuncture curative effect. With the technique limited, the researches on acupuncture manipulations can only be carried out with respect to the senses and experience of doctors and patients, thus seriously impeding the modernization and internationalization of acupuncture. Both the modern integration technology of transducer and the biomechanical principles are applied to develop a detection system that can measure the interaction force between the manipulator and the manipulated patient on the needle at each kind of manipulation. Through clinical practice, the force waveforms acting on needle with the manipulations of symmetrical twirling-rotating and symmetrical lifting-inserting were recorded so as to realize the quantitative, objective and real-time detection of the force during the acupuncture process, which provided a new experimentation means and analysis method for the improvement of clinical curative effect and quantitative research of acupuncture and meridians.

Acupuncture↗
PubMed2003

Effect of preoperative transcatheter arterial chemoembolization on apoptosis of hepatocellular carcinoma cells.

OBJECTIVE: To evaluate the effect of preoperative transcatheter arterial chemoembolization(TACE) on apoptosis of hepatocellular carcinoma (HCC) cells. METHODS: A total of 136 patients with HCC underwent liver resection. One to five courses of TACE prior to liver resection were performed in 79 patients (TACE group), in which one to four courses of chemotherapy alone were performed in 11 patients (group A), one to five courses of chemotherapy combined with iodized oil were performed in 33 patients (group B), one to three courses of chemotherapy combined with iodized oil and gelatin sponge were performed in 23 patients group C) and one to three courses of chemotherapy combined with iodized oil, ethanol and gelatin sponge were performed in 12 patients (group D). The other 57 patients only received liver resection (non-TACE group). The extent of apoptosis was analyzed by transferase-mediated dUTP nick end labeling (TUNEL) staining. The expressions of Bcl-2 and Bax protein were detected by immunohistochemical method. RESULTS: The apoptotic index(AI) and level of Bax protein in HCC cells were significantly higher in groups A, B, C and D than those in the non-TACE group (P < 0.05). The level of Bcl-2 protein and ratio of Bcl-2 to Bax protein of HCC cells were significantly lower in Groups A, B, C and D than those in the non-TACE group (P < 0.05). CONCLUSION: Preoperative TACE regimens may enhance apoptosis of HCC cells by up-regulating the expression of Bax protein and down-regulating the expression of Bcl-2 protein and ratio of Bcl-2 to Bax protein expression.

Adult↗
PubMed2003

[A serial study of in cytogenetic change and morphology on the tetra-arsenic tetra-sulfide treatment in untreated or recurrent acute promyelocytic leukemia].

OBJECTIVE: To study the morphologic and cytogenetic change in acute promyelocytic leukemia (APL) patients during the tetra-arsenic tetra-sulfide (TATS) treatment and the mechanism of TATS. METHODS: The bone marrow cells of 13 newly diagnosed and 7 recurrent APL patients were studied through FISH and morphology during the TATS treatment by special and repeated marrow culture. RESULTS: Cytomorphological study of 8 cases (6 untreated and 2 recurrent) showed that TATS could differentiate APL cells forward to mature granulocytes. There was obvious correlation between the reduced t (15; 17) positive cells and the reduced APL cells (r range 0.7298 - 0.9989). Except one patient with t (11; 17), 19 (13 untreated and 7 recurrent) with translocation t (15; 17) achieved clinical CR including 16 who achieved cytogenetic CR. CONCLUSION: TATS has a differentiation-inducing effect on untreated and recurrent APL, with haematological CR and cytogenetic CR achieved. Measurement of t (15; 17) positive cells by FISH technique can reflect the change of APL cells objectively.

Adult↗
PubMed2003

[Selectivity and tolerance of sea urchin (Hemicentrotus pulcherrimus) to environmental change].

An experimental ecological study of sea urchin (Hemicentrotus pulcherrimus) sampled from coastal waters of Qingdao was focused on the fundamental ecological factors such as temperature, salinity, light intensity and substratum. The results showed that the suitable ecological range of temperature was from 8 degrees C to 22 degrees C, and the selectivity to temperature was changed with the previous living temperatures. Hemicentrotus pulcherrimus was a kind of stenohaline creature. Its optimum ecological range of salinity was from 30 to 35. The results also showed that Hemicentrotus pulcherrimus liked to select weak light environment (< 50 lux), especially under non-food condition. Hemicentrotus pulcherrimus had the positive substratum-selectivity to coarse sand and the negative substratum-selectivity to silver sand.

Animals↗
PubMed2003

[A randomised clinical trial to study the effects of raloxifene hydrochloride on bone mineral density, biochemical markers of bone metabolism and serum lipids in postmenopausal women].

OBJECTIVE: To determine the effect of raloxifene hydrochloride (RLX) on bone mineral density (BMD), biochemical markers of bone metabolism and lipid metabolism in Chinese postmenopausal women. METHODS: This was a multicenter, randomized, double blind placebo controlled study in China with a total of 204 postmenopausal women [mean age (60 +/- 5) years (x +/- s) and weight (63 +/- 9) kg (x +/- s)] treated with either RLX 60 mg (n = 102) or placebo (n = 102) daily for 12 months. BMD, serum lipid and bone markers were determined before and after drug administration. RESULTS: Compared to placebo, RLX produced a significant increase in both total lumbar spine and total hip BMD. For the lumbar spine, percentage increase in total BMD was 2.30% with RLX compared to a decrease of 0.08% with placebo (P < 0.001). Corresponding values for total hip BMD were 2.46% increase for RLX and 1.07% for placebo (P < 0.05). For biochemical markers of bone metabolism, serum osteocalcin and C-telopeptide, percentage decrease were 27.6% and 24.0% in raloxifene-treated subjects. Corresponding values in placebo were 10.6% decrease and 15.8% increase (RLX compared to placebo, both P < 0.001). For total cholesterol and low-density lipoprotein cholesterol, percentage decrease were 6.4% and 34.6% in the raloxifene-treated group. Corresponding values in placebo were 1.4% increase and 19.1% decrease (RLX compared to placebo, both P < 0.001). No differences were found for high-density lipoprotein cholesterol or triglyceride levels between the two groups. Only 5 subjects discontinued early due to an adverse event (3 in the RLX group and 2 in the placebo group). CONCLUSIONS: This study confirms that RLX exerts positive effects on the skeleton, increasing BMD and decreasing biochemical markers of bone metabolism, and decreased total cholesterol and low-density lipoprotein cholesterol in postmenopausal women in China.

Aged↗
PubMed2003

Effects of raloxifene hydrochloride on bone mineral density, bone metabolism and serum lipids in postmenopausal women: a randomized clinical trial in Beijing.

OBJECTIVE: To determine the effects of raloxifene hydrochloride (RLX) on bone mineral density (BMD), bone metabolism markers and serum lipids in healthy postmenopausal women in Beijing. METHODS: A multicenter, randomized, double-blind, placebo-controlled study was conducted in a total of 204 healthy postmenopausal women (age 59.5 +/- 5.0 years and weight 62.8 +/- 8.7 kg) treated with either RLX 60 mg (n = 102) or placebo (n = 102) daily for 12 months. BMD, serum lipids, and bone markers were measured before and after drug administration. RESULTS: Compared with placebo, RLX produced a significant increase in both total lumbar spine and total hip BMD. For the lumbar spine, percentage increase in total BMD was 2.3% with RLX compared with a decrease of 0.1% with placebo (P < 0.001). Corresponding values for total hip BMD were a 2.5% increase for RLX and a 1.1% increase for placebo (P = 0.011). For biochemical markers of bone metabolism, serum osteocalcin and C-telopeptide, percentage decreases were 27.65% and 24.02% in RLX-treated subjects. Corresponding values in placebo were a 10.64% decrease and a 15.75% increase (RLX compared with placebo, both P < 0.001). For total cholesterol and low-density lipoprotein cholesterol levels, percentage decreases were 6.44% and 34.58% in the RLX-treated group. Corresponding values in placebo-treated patients were a 1.44% increase and a 19.07% decrease (RLX compared with placebo, both P < 0.001). No differences were found for high-density lipoprotein cholesterol or triglyceride levels between the two groups. Only 5 subjects discontinued early owing to an adverse event (3 in the RLX group and 2 in the placebo group). CONCLUSIONS: This study confirms that RLX exerts positive effects on the skeleton, increasing BMD and decreasing biochemical markers of bone metabolism, and has a positive effect on the overall serum lipid profile in postmenopausal women in China.

Aged↗
PubMed2003

A follow-up study of 69 discharged SARS patients.

Sixty-nine patients with severe acute respiratory syndrome (SARS) discharged from Guangdong Provincial TCM Hospital were followed up from January to April 2003 during which the patients were asked to fill the questionnaire form and at the same time received blood routine examination, hepatic, renal, pulmonary and immune function tests, and spiral computerized tomography (CT) of the chest, color B-ultrasonography of the heart with the collected data treated by descriptive analysis and deductive analysis. The results showed that in the 69 followed-up patients, impairment of the hepatic function was found in 5 cases, hypoimmune state in 18, impediment of ventilation in the distal air passages with normal major air passages in 15, increased residual volume in 40, mild disturbance of pulmonary diffusion function in 14, incomplete absorption of inflammatory exudates, focal or multiple interstitial lesions, pulmonary interstitial fibrosis and pleural adhesion in 24; increased resistance or mild systolic hypertension in the pulmonary circulation, and segmental ischemia of the left myocardium in 34; and decreased visual acuity in 2. According to TCM differentiation 24 cases belonged to the type of deficiency of both qi and yin, 8 deficiency of both the heart and spleen, 37 depression of the liver and deficiency of the spleen, 18 intermingling with damp-heat, and 7 intermingling with stagnant blood. Some patients still had psychological problems. The study indicates that though clinically cured and discharged from hospital, some SARS patients have functional impairment of the heart, lung and liver, hypoimmune state as well as psychological problems, and need to be treated accordingly for a complete recovery. A rationale for suggested TCM treatment is expounded.

Diagnosis, Differential↗