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Biomedical subjects

Q Liu

Publications and source records attributed to Q Liu.

At least 271 records · Page 15Linked to original sources
PubMed2000

Selecting anti-HBsAg fab phage antibodies from the phage antibody library.

OBJECTIVE: Selecting Fab phage antibodies to HBsAg from the phage antibody library. METHODS: The phages displaying antibody fragments were subjected to three rounds of panning with HBsAg coated in solid phase. RESULTS: The eluted phages were enriched nearly 80-fold, and the percentage of recombinant clones increased from 17% to 100% after the third round of panning. The HBsAg specific monoclonal antibodies were determined by ELISA. These antibodies combined specifically with HBsAg, but not with BSA and HAV antigens. CONCLUSION: Our work on constructing human immunoglobulin combinatorial library and selecting anti-HBsAg Fab phage antibodies would be beneficial to the further study on the production of soluble Fab antibodies.

Bacteriophages↗
PubMed2000

Effect of thromboxane synthase inhibitor, CS-518, on propranolol-induced bronchoconstriction in guinea pigs.

Beta-adrenoreceptor antagonists, such as propranolol, can provoke severe bronchoconstriction in asthmatic subjects. Recently we developed an animal model of propranolol-induced bronchoconstriction and investigated the involvement of chemical mediators in this reaction. The purpose of this study was to elucidate the role of thromboxane A2 in the development of propranolol-induced bronchoconstriction after allergic bronchoconstriction. Passively sensitized guinea pigs were anesthetized and treated with diphenhydramine hydrochloride and were then artificially ventilated. Propranolol at a concentration of 10 mg/ml was inhaled 20 min after an aerosolized antigen challenge. A potent and selective thromboxane A2 synthase inhibitor, CS-518, in doses of 0.01, 0.1 and 1 mg/kg and vehicle were administered intravenously 15 min after the antigen challenge. Another study was performed in naive guinea pigs; ascending doses of methacholine (12.5, 25, 50, 100 and 200 microg/ml) were inhaled for 20 sec at 5-min intervals, 10 min after intravenous administration of CS-518. Propranolol inhaled 20 min after the antigen challenge caused bronchoconstriction in sensitized guinea pigs. CS-518 administered 15 min after the antigen challenge significantly inhibited propranolol-induced bronchoconstriction in a dose-dependent manner, while CS-518 did not influence the dose-dependent response to inhaled methacholine in naive guinea pigs. We conclude that thromboxane A2 contributes to the development of propranolol-induced bronchoconstriction following allergic reaction in our guinea pig model.

Adrenergic beta-Antagonists↗
PubMed2000

Prevention of falls and fall-related fractures through biomechanics.

Falls and fall-related injuries are a major health problem for elderly people. Biomechanical studies provide important insight into the cause of such events and reveal new techniques for preventing them. The topics reviewed in this article include balance recovery, safe landing responses, impact forces during falls, and fracture prevention through exercise programs, hip pads, and energy-absorbing floors.

Accidental Falls↗
PubMed2000

Therapeutic drug monitoring of paclitaxel (Zisu) in cancer patients.

We monitored the therapeutic drug paclitaxel (Zisu) and studied its anticancer activity and side effects in 11 cancer patients. After intravenous infusion of 135 to 185 mg/m2 of paclitaxel, Cmax ranged from 2.17 to 9.17 mg/L and AUC ranged from 4.37 to 16.01 mg/h/L. A significant individual difference in pharmacokinetic parameters was found. Among the 11 patients, 6 achieved a partial remission and one patient had a mild response. The Cmax of the patients who achieved PR and MR was higher in comparison to the patients with no response. In 4 of the 6 PR patients, Cmax was above 4.38 mg/L. In four of the NR patients, Cmax was equal to or below 4.04 mg/L. These results suggested a relationship between Cmax and the cancer response rate. No significant relationship could be found between Cmax and the nadir of the white blood cells and platelets.

Adult↗
PubMed2000

[The application of fluorescence in situ hybridization performed on the decolorized G-banding chromosomes in detecting the marker chromosomes of gastric cancer].

OBJECTIVE: Using a rapid, accurate method that detects the marker chromosomes of gastric cancer and enhancing the ability of discriminating complicated chromosome rearrangements of gastric cancer. METHODS: The improved method of fluorescence in situ hybridization(FISH) performed on the decolorized G-banding chromosome was used. RESULTS: The changes of two marker chromosomes (M1, M2) of the cell line(SGC-7901) of gastric cancer and one marker chromosomes(M3) of one primary gastric cancer were respectively analyzed by this method. The M1, M2 and M3 had complicated structural chromosome aberrations: del(7)(p15)/del(7)(q22), t(1;3)(p11;q11) and del(7)(q32). CONCLUSION: This method showed strong signals, low backgrounds and well-repetitions. It may play an important part in exploring the chromosome rearrangements in the process of pathogenesis and development of gastric cancer.

Chromosome Aberrations↗
PubMed2000

The relationship of angiotensin-converting enzyme gene to essential hypertension and drug treatment in Chongqing.

OBJECTIVE: To measure and discuss the association of the angiotensin converting enzyme (ACE) gene insertion/deletion(I/D) polymorphism with essential hypertension and drug treatment in Chongqing. METHODS: Polymerase chain reaction(PCR) method was used to amplify the sixteenth intron of the ACE gene for the analysis of 114 healthy controls and 75 patients with essential hypertension. At the same time, 49 patients with essential hypertension were randomly divided into two groups for a placebo-controlled crossover comparison of ACEI versus CCB. RESULTS: The frequency of homozygous alleles DD and the frequency of deletion alleles were significantly higher in the essential hypertension group than in the healthy controls(P>0.005). The blood pressure decreased more in the DD genotype subjects when treated with the ACEI but decreased less when treated with the CCB (15.91 vs 12.43, P<0.1). The blood pressure decreased more in the II genotype subjects when treated with the CCB but decreased less when treated with the ACEI (16.55 vs 9.6, P<0.05). CONCLUSION: The results indicate that a deletion (DD) polymorphism of the ACE gene is associated with essential hypertension in Chongqing. Detection of the ACE genotype in clinics is helpful to the selection of antihypertensive drugs.

Adult↗
PubMed2000

Inverted-repeat DNA: a new gene-silencing tool for seed lipid modification.

Post-transcriptional gene silencing (PTGS) has been successfully used to modify seed lipids in oilseed crops like soybean, canola and sunflower. Conventionally, PTGS has been induced by transforming the plants with either antisense or co-suppression constructs targeted against key seed lipid biosynthesis genes. A major drawback of this approach has been the recovery of only a modest proportion of silenced individuals from large populations of transgenic plants. In this report we show that inverted-repeat DNA constructs containing an intron encoding RNA with a hairpin structure can induce PTGS with very high frequency.

Arabidopsis↗
PubMed2000

Genetic modification of cotton seed oil using inverted-repeat gene-silencing techniques.

Inverted-repeat-based gene constructs targeted against two key cotton seed-specific fatty acid desaturase genes, ghSAD-1, encoding stearoylacvl carrier protein delta9-desaturase and ghFAD2-1, encoding microsomal omega-6 desaturase, were transformed into cotton. The expression of ghSAD-1 and ghFAD2-1 in the inverted-repeat orientation resulted in increased levels of stearic and oleic acids, respectively. Interestingly, the content of palmitic acid in both high-stearic and high-oleic lines was substantially reduced. These materials offer the promise of developing cotton seed oil products with greatly improved nutritional appeal to consumers.

Cottonseed Oil↗
PubMed2000

Sequence diversity of serine repeat antigen gene exon II of Plasmodium falciparum in worldwide collected wild isolates.

Field isolates of Plasmodium falciparum collected from endemic areas of Southeast Asia, Solomon Islands, tropical African countries and Brazil were analyzed for the genetic diversity of the exon II of serine repeat antigen gene (SERA) by sequencing of genomic DNA. Of sixty-nine isolates, as compared to the reported FCR3, K1 and Honduras-1 types of exon II sequences, 5, 9 and 20 new allelic forms were found in 23 isolates of the FCR3 type, 36 of the K1 type and 10 of the Honduras-1 type. A group of novel non-synonymous substitutions, 4 new insertions and 3 new deletions of octamer units were found in the octamer repeat region (OR) of the exon II, and most of them clustered within a 40-residues domain. An octamer "SNPVSSEP" revealed in the OR was confirmed as a new repeat unit. Based on the sequences of the serine repeat region (SR) of the exon II, the allelic forms of the Honduras-1 type were conjectured to be the recombinant forms between the K1 type and FCR3 type. The allelic forms of K1 type with less or more repeat serine residues in the serine stretch of the SR than the reported 21 serine residues had most of the variations in the OR. Moreover, a biased geographical distribution of allelic forms was observed. Isolates from African and Southeast Asian countries accounted for most of the new allelic forms (29/33). All of the three types were detected in Southeast Asia but none of the FCR3 type in Africa. One of two groups of FCR3 new allelic forms was found solely in Brazil while another was mainly in Solomon Islands.

Alleles↗
PubMed2000

[Effect of lanthanum on growth and biochemical property of Sclerotinia sclerotiorum].

The study shows that La2O3 at a concentration of 30-450 mg.L-1 could inhibit the growth of S. sclerotiorum in both solid and liquid media and the inhibition effect was increased with its increasing concentration. The activity of pectinase produced by S. sclerotiorum in liquid medium was also increased with increasing La2O3 concentration.

Ascomycota↗
PubMed2000

[Expression of MAGE-3 gene product in non-small cell lung cancer].

OBJECTIVE: To study the expression of MAGE-3 antigen in non-small cell lung cancer (NSCLC). METHODS: The expression of MAGE-3 antigen was examined in formalin fixed, paraffin embedded sections of NSCLC by LSAB immunohistochemical technique. RESULTS: MAGE-3 antigen was detected in 31 of 104 (29.8%) patients with primary NSCLC. The frequency of MAGE-3 expression was significantly correlated to the absence of metastasis (P < 0.05) and better survival rate (P < 0.01). There was no significant relationship between MAGE-3 expression and histological type of NSCLC. CONCLUSION: MAGE-3 antigen expression in NSCLC correlates with better prognosis. It is a candidate molecular target for specific immunotherapy for NSCLC patients.

Adult↗
PubMed2000

[Clinical observation on therapeutic effect of xinyikang oral liquid in treating 92 patients of viral myocarditis].

OBJECTIVE: To observe the clinical effect of Xinyikang Oral Liquid (XYK) in treating viral myocarditis patients of Qi-Yin Deficiency and Evil-Toxin Encroaching Heart Type. METHODS: Randomized controlled method was adopted, the 92 cases in the XYK group received XYK and 30 cases in the control group received Qidong Yixin oral liquid treatment for 4 weeks as a therapeutic course. Their symptoms, signs, white blood cell count (WBC), erythrocyte sedimentation rate (ESR), lactate, aspartate aminotransferase (AST) dehydrogenase (LDH), creatine phosphokinase (CPK), creatine phosphokinase isoenzyme (CPK-MB), electrocardiogram (ECG) and dynamic ECG changes before and after treatment were observed. RESULTS: The improvement on chest stuffiness, short breath, fatigue and spontaneous perspiration in the treatment group was better than those in the control group (P < 0.05) and XYK showed obvious improving effect on ESR, AST, LDH, CPK and CPK-MB (P < 0.01 or 0.05). There was no adverse reaction or side-toxic effects revealed in using XYK. CONCLUSION: XYK has significant therapeutic effect in treating viral myocarditis.

Adolescent↗
PubMed2000

[Detection of Escherichia coli strains harboring pathogenicity island of Yersinia enterolitica in diarrheal patients and animals in China].

OBJECTIVE: To investigate the prevalence of Escherichia coil strains harboring high pathogenicity island of Yersinia enterocolitica in diarrhea patients, animals, food samples and resulted clinical symptoms. METHODS: Colony hybridization, DNA dot hybridization and polymerase chain reaction (PCR) were used. RESULTS: HPI - harboring E. coli were found in the strains isolated in various provinces of China. The isolation rates were 27.05% (436/1,612) in the strains isolated from diarrhea patients, 10.23% (9/88) in the strains isolated from food samples and 5.71% (16/280) in the strains isolated from feces of cattle and pigs. Typical clinical symptoms of diarrhea caused by HPI - harboring E, coli were inappetency, abdominal pain, shiver and vapidity. Patient's temperature was usually normal or low. Over six episodes of diarrhea was frequently observed, of which most were unformed stools with mucous. CONCLUSION: E. coli strains harboring high - pathogenicity - island of Yersinia species were frequently isolated from diarrhea patients, animals and food samples as well, which might be one of the major causes of diarrhea in China.

Animals↗
PubMed2000

[Mechanism of recombinant human growth hormone accelerating burn wound healing in burn patients].

OBJECTIVE: To investigate the mechanism of recombinant human growth hormone (rhGH) in acceleration of burn wound healing. METHODS: Thirty three severe burn patients were enrolled in this study and randomly divided into rhGH group (n = 18) and placebo control group (n = 15). The rhGH was administered subcutaneously in the dose of 0.1 mg . kg(-1) at 10 pm every evening in rhGH group for 14 days, while normal saline was used as a placebo in the control group. The serum concentration of GH and IGF-1 were assayed with ELISA method, and the proliferation index (PI) and S-phase fraction (SPF) of wound tissue was analyzed by flow cytometry (FCM). The expression of PCNA, EGFR and CK was assessed by immunohistochemical stains. RESULTS: Serum concentrations of GH and IFG-1 increased significantly after rhGH administration. The PI and SPF of wound tissue were obviously higher than those before rhGH administration and those in the control group. The expressions of PCNA, EGFR and CK was enhanced. In addition, the epidermis of healed wound was thicker in rhGH group than that in the control group. CONCLUSION: The application of rhGH in burn patients could improve the serum concentration of GH and IFG-1, promote DNA synthesis and PCNA and EFGR expression of epithelium, so that re-epithelialization of the burn wound could be accelerated.

Adult↗
PubMed2000

[Autologous bone marrow transplantation for patients with chronic myelogenous leukemia after in vitro purging of the graft with bcr/abl antisense oligodeoxynucleotides].

OBJECTIVE: To investigate the efficacy of autologous bone marrow transplantation (ABMT) for patients with chronic myelogenous leukemia (CML) after in vitro purging of the graft with bcr/abl antisense oligodeoxynucleotides (AS-ODN). METHODS: Five CML patients, 2 in chronic phase (CP), 1 in accelerated phase (AP) and 2 in blast crisis (BC), all confirmed the presence of b3a2 bcr/abl mRNA by RT-PCR (reverse transcriptase-polymerase chain reaction). Patients had received 2 courses of intensive chemotherapy for "in vivo purging" before bone marrow harvesting. The autologous bone marrow cells were concentrated by CS3000plus and then incubated with 18-mer phosphorothioate bcr/abl AS-ODN (40 - 60 microg/ml, for 48 - 60 h). Conditioning regimens were TBI + Cy (total body irradiation + cyclophosphamide) or MAC + CCNU. RESULTS: After intensive chemotherapy, ph(+) cells in bone marrow reduced to 34% (24% - 46%) and the numbers of bcr/abl mRNA (+) CFU-GM to 45.6% (33% - 58%). After bcr/abl AS-ODN in vitro purging, two patients were bcr/abl mRNA negative and three positive with the number of bcr/abl mRNA (+) CFU-GM markedly reduced. Delayed hematopoietic reconstitutions were observed in all patients after ABMT. During a more than 2 years follow-up period, three patients obtained major cytogenetic remission (MCR) and lasted for 9 - 12 months and the durations of CP after ABMT were longer than that before ABMT. One of this three in BC before ABMT being survived disease-freely for 37 months with bcr/abl mRNA (-) after ABMT. Another patient in BC had a short duration of MCR and relapsed at +7 months. One patient died from severe infection and bleeding at day +74 because of delayed reconstitution. CONCLUSION: ABMT with bcr/abl AS-ODN purged graft can result in quite long duration of MCR and prolonged CP in some patients with CML.

Adolescent↗
PubMed2000

[Effect of sub-acute low level exposure to lead on cellular immune function in rats].

In order to observe the influence of low level exposure to lead on cellular immune functions in rats, sixty rats were randomly divided into six groups and were received diets with different levels of lead for eight weeks. Blood lead, serum tumor necrosis factor-alpha(TNF-alpha) level and the distribution of T lymphocyte subsets were measured. The pathological and ultrastructural changes of spleen were investigated. It was shown that lead exposure resulted in a significant increase of blood lead and decrease of the number of CD4 T-cells. But no significant difference was found in CD8 T-cell among all groups. Serum TNF-alpha at the lowest exposure group was significantly increased but that in other groups was lower than the control group. Electron microscopy for splenic immune cells indicated no significant difference between the lowest lead exposure group and the control group. The mitochondria of other groups were swollen, vaculated and pyknotic, endoplasmic reticulum were swollen and degranulated, nuclear chromatin were loosen. It was suggested that sub-acute exposure to lead, even at relative low exposure, would impair cell-mediated immunity and be harmful to spleen and thymus.

Animals↗
PubMed2000

[Cloning and tissue expression pattern analysis of the human citrate synthase cDNA].

Tricarboxylic acid (TCA) cycle is an important way to generate ATP, which is widely distributed in the cells of animal, plant or microorganism. It catalyses the catabolism of sugar as well as protein and fat. Citrate synthase plays a key role in regulating TCA cycle and is responsible for catalysing the synthesis of citrate from oxaloacetate and acetyl CoA. Screening of genomic informatics was performed by using pig citrate synthase cDNA as a probe and a contig which is 1636 bp long and has highly homologous to the pig citrate synthase cDNA was obtained from selected ESTs with the ASSEMBLY program. According to the sequence of this contig, a pair of primers was designed and used to amplify cDNA libraries. A 1492 bp cDNA containing an open reading frame encoding 466 amino acids was cloned from human testis and skeletal muscle cDNA libraries. The deduced amino acid sequence of the cDNA showed 95%, 92% and 60.9% identity to pig, chicken and yeast citrate synthase respectively. Because the deduced amino acids sequence contains a highly conserved motif of citrate synthase from three different species, it is believed that this cDNA may be a transcript of human citrate synthase gene. Northern analysis showed that the human citrate synthase was expressed at high level in heart and muscle, at middle level in brain, kidney and pancreas tissues, not detectable in thymus and small intestine tissues, and at low level in other nine tested human tissues.

Amino Acid Sequence↗