Biomedical subjects

B Zhang

Publications and source records attributed to B Zhang.

At least 145 records · Page 8Linked to original sources

PubMed2001

Identification of SNPs in human gamma aminobutyric acid A receptor gamma2 gene.

Gamma aminobutyric acid (GABA) is a major inhibitory neurotransmitter. Because of its importance and diverse functions, studies of single nucleotide polymorphisms in the GABA receptor genes are of great significance, which may produce useful molecular markers for genetic analysis of neurological disease, and possibly lead to the discovery of pathogenic mutations. We identified eleven SNPs in the entire exon regions, immediate intron regions and promoter region of human GABA receptor gamma2 gene by direct sequencing. In this discovery, 2 non-synonymous cSNPs and 1 splicing variant are found.

Evolution, Molecular↗

PubMed2001

[Chromosomal aberration analyzed by comparative genomic hybridization in nasopharyngeal carcinoma].

OBJECTIVE: To identify genetic alteration in primary sporadic nasopharyngeal carcinoma(NPC) in Hunan. METHODS: Comparative genomic hybridization was applied to investigate the genomic imbalance in a series of 20 cases of primary nasopharyngeal carcinomas. RESULTS: The common chromosomal alterations included gains of chromosomes 1q, 2, 3q, 7q,8q,12 as well as losses of chromosomes 3p, 9p, 11q, 16q. CONCLUSION: There are multiple regions of chromosomes with copy number changes in NPC. The tumor suppressor genes and oncogenes on these regions may be involved in the development and progress of nasopharyngeal carcinoma.

Chromosome Aberrations↗

PubMed2001

[Adenovirus-mediated transfer of human wild-type p53, GM-CSF, and B7-1 genes efficiently produces growth suppression and apoptosis of hepatocellular cells in vitro].

OBJECTIVE: To investigate the tumor suppressor activity of recombinant adenovirus vector expressing the human wild-type p53, GM-CSF, and B7-1 proteins (designated as BB-102) in human hepatocellular carcinoma cells (HCC) in vitro. METHODS: The wild-type p53 BEL-7402, mutant p53 HLE, and HuH-7 HCC cell lines were infected with BB-102 at MOI of 50 in vitro. Immunohistochemical assay was used to determine p53 expressed by BB-102. Tumor suppressor activity of the expressed p53 was identified by terminal deoxynucleotidy I transferase (TdT) assay in BB-102-infected HCC cell lines. RESULTS: p53 protein was found to express in a dose-dependent manner in BB-102-infected HCC cell lines. The proliferation of HCC cell lines were suppressed significantly at the average rates of 58.5%, 81.5%, and 71.1% for BEL-7402, HLE, and HuH-7 respectively from 4 to 10 days, accompanying inducing apoptosis in BB-102-infected HCC cell lines. CONCLUSIONS: Besides the expression of B7-1 and GM-CSF, BB-102 is able to express p53 protein in independent manner and exerts its anti-tumor activity, which suggests that BB-102 may be useful for gene therapy against HCC in vivo.

Adenoviridae↗

PubMed2001

[Clinical efficacy of double autologous hematopoietic stem cell transplantation in the treatment of adult acute lymphoblastic leukemia].

OBJECTIVE: To evaluate the clinical efficacy of double autologous hematopoietic stem cell transplantation (DAHSCT) in adult acute lymphoblastic leukemia and analyse the affecting factors. METHODS: Thirteen adult acute lymphoblastic leukemia (ALL) patients received the first AHSCT in 12 months after complete remission (CR). The first conditioning regimen was Vp16,600-1000 mg or Ara-C 2-4 g/m2, CTX 120 mg/kg, total body irradiation(TBI) 7.5-9.0 Gy and in 6 patients BCNU 125 mg was added. All the patients received the second AHSCT in 4 to 10 months after the first AHSCT. The second conditioning regimen was Vp16,600-1000 mg or Ara-C 2-4 g/m2, Mel 140 mg/m2, CTX 120 mg/kg. RESULTS: All engrafted patients had rapid hematopoietic reconstitution. There was no AHSCT related death. The median follow-up duration was 837 days. Seven of the 13 DAHSCT patients were alive. The 3 year disease-free survival (DFS) was (53.8 +/- 7.7)%. Those who had more lymphoblasts in bone marrow at the second AHSCT than that at the first AHSCT had greater probability of relapse. CONCLUSION: It suggested that DAHSCT could be used as an important treatment owing to its low AHSCT related death and relatively long DFS.

Adolescent↗

PubMed2001

Induction of apoptosis by superoxide anion and the protective effects of selenium and Vitamin E.

OBJECTIVE: The purpose of this study is to investigate the effect of superoxide anion on the apoptosis of cultured fibroblasts and the protective role of selenium and Vitamin E. METHODS: Cultured fibroblasts (NIH3T3), with or without selenium or vitamin E in the medium, were treated by superoxide anion produced by xanthine/xanthine oxidase reaction system and changes in cell structure and DNA were observed microscopically and electrophoretically. RESULTS: Apoptosis was observed when superoxide anion at a concentration of 5 nmol/L or 10 nmol/L had acted on the fibroblasts for 5-10 h. Selenium and Vitamin E in the medium inhibited the apoptosis significantly when their concentrations reached 1.15 mol/L and 2.3 mol/L respectively. CONCLUSION: Selenium and vitamin E have protective effect against the apoptosis induced by superoxide anion. The effect of selenium is more remarkable than that of vitamin E.

Antioxidants↗

PubMed2001

Genotypes and polymorphisms of mutant CCR5-delta 32, CCR2-64I and SDF1-3' a HIV-1 resistance alleles in indigenous Han Chinese.

OBJECTIVE: To evaluate the frequencies and polymorphisms of CCR5-delta 32, CCR2-64I and SDF1-3' A alleles conferring resistance to HIV-1 infection in Chinese population from Han ethnic origin. METHODS: This cohort was comprised of 1251 subjects (915 men and 336 women) aged 15-80 years and none was HIV-1 positive. Genotyping of allelic CCR5-delta 32, CCR2-64I and SDF1-3' A variants was performed using PCR or PCR/RFLP assay, and further confirmed by direct DNA sequencing. RESULTS: Our finding shows that the delta 32 deletion mutation in the CCR5 gene does occur in this population and can be inherited in a Mendelian fashion in indigenous Han Chinese at a very low frequency of 0.00119 (n = 1254). The frequencies of mutant CCR2-64I and SDF1-3' A alleles were 0.20023 (n = 1251) and 0.2873 (n = 893), in this population, which are higher than those found in American Caucasians. Furthermore the polymorphisms of CCR2-64I and SDF1-3' A alleles in the Han Chinese population were different from those in American Caucasians. Statistical analysis showed that the genotype distribution of CCR5-delta 32, CCR2-64I and SDF1-3' A alleles was in equilibrium according to the Hardy-Weinberg equation. CONCLUSION: The CCR5-delta 32 mutation may not be a major resistant factor against HIV-1 infection in indigenous Han Chinese. The significance of higher frequencies of CCR2-641 and SDF1-3' A alleles (0.20023 and 0.2791) in the Han population remains to be clarified in HIV-1-positive carriers and AIDS patients.

Acquired Immunodeficiency Syndrome↗

PubMed2001

[Technique of implanting 17 alpha-methyltestosterone to induce the sex reversal of Epinephelus malabaricus].

This paper discussed the method of implanting 17 alpha-methyltestosterone to induce the sex reversal of Epinephelus malabaricus, which included chemical treatment, dosage and operating on the fish. After twice implanting of exogenous hormone, the mature females of 3 years old were transformed into functional males. Sperm could be squeezed from 58% of the fish on 139 days after operating, and from 100% on 301 days. When the functional males were used for artificial breeding, the parent fish spawned in a natural way, and 71.03 million larvae were hatched in the two years of 1999-2000. The larvae were used for rearing of fish fry, from which normally growing young fish was get. It is believed that the method of implanting exogenous hormone to induce the sex reversal of E. malabaricus is easy and stable, which can satisfy the requirement of artificial breeding in factories.

Animals↗

PubMed2001

[Correction of nasal deformity in unilateral cleft lip of adult cases].

OBJECTIVE: Nasal deformities are very common in unilateral cleft lip cases. They are morphology of alar collapse, nasal floor depression and deviation of the septum. METHODS: Our operation procedure includes correction and replacement of the septum to the middle position, mobilization and suspension of the displaced alar cartilage and use of a "C" flap, nasal sill flap or a flap of the lip scar tissue to increase the length of columella on the cleft side. An implant or autograft of suitable size is placed, if necessary, in the nasal bridge or/and the nasal floor. RESULTS: Postoperative follow-up for 1-12 months showed that the results are satisfactory. CONCLUSIONS: Correction of septum deformity, and increase of the length of the columella on the cleft side are important. An extensive mobilization and reposition of the alar cartilage must be done for obtaining a symmetric nasal projection. If necessary, a fine implant or self-tissue is placed in the nasal bridge and nasal floor, which would make the result much better.

Adult↗

PubMed2001

[Survey on the high risk behaviors related to acquired immunologic deficiency syndrome and sexually transmitted diseases among men who have sex with men in mainland China].

OBJECTIVE: To understand the high risk behaviors related to acquired immunologic deficiency syndrome (AIDS) and sexually transmitted diseases (STDs) among men who have sex with men (MSM) in mainland China. METHODS: A self-administrated anonymous mail survey was carried out in MSM throughout the mainland of China in 1999. RESULTS: One thousand eight hundred questionnaires were mailed out and 729 effective questionnaires were collected. The response rate was 40.5%. The average age of subjects was 31 years old. Their average age at first sexual intercourse with a man was 18.6 years old. Average number of male sexual partners were 39.2 out of which 75.7% reported having had anus-intercourse. In the latest year, 63.6% reported ever having sex with strange men, 39.8% reported ever having group sex, 9.3% reported having sold sex and 3.8% having bought sex. 50% of them reported ever having sex with women. One hundred thirty-three reported having been diagnosed STD. Sixty-two reported having tested for HIV antibody and 11 were positive. Two-thirds reported ever using a condom when having sex. CONCLUSION: High risk sexual behaviors were prevalent among MSM in mainland China with HIV infection rate already reaching a high level. Women having sex with MSM are at a greater risk of HIV infection.

Acquired Immunodeficiency Syndrome↗

PubMed2001

[Characterisation of transient outward potassium current (Ito1) in hypertrophied right ventricular myocytes from children with tetralogy of Fallot].

OBJECTIVE: To investigate whether a transient outward potassium current exists in children hypertrophy ventricular myocytes and to characterize its basic electrophysiological properties. METHODS: Currents were recorded using whole-cell patch-clamp technique from enzymatically isolated ventricualr myocytes obtained from hearts of 10 patients aged 0.4-5 with tetralogy of Fallot (F4) ranging in age 0.4-5 years. RESULTS: In almost all cells studied, a Ito1 could be recorded on depolarization to between -20(-)+60 mV under conditions in which Ca2+ current was blocked. The current density is 4.7 PA/PF +/- 0.6 PA/PF at 60 mV. Its inactivation time constants under tested potential 0, 20, 40, 60 mV were 123 ms +/- 6 ms, 131 ms +/- 11 ms, 122 ms +/- 6 ms, 122 ms +/- 6 ms Half-maximal activation occurred at 4.1 mV +/- 2.8 mV. Half-maximal steady-state inactivation was -41 mV +/- 4 mV. Recovery from inactivation was voltage-dependent and the time course was 83 ms +/- 4 ms. CONCLUSION: A moderate Ca(2+)-independent transient outward K+ current is present in hypertrophied human ventricular myocytes from children with tetralogy of Fallot, its basic characteritics are similar to Ito1 observed in other species and human atria.

Child, Preschool↗

PubMed2001

Effects of free radicals and amyloid beta protein on the currents of expressed rat receptors in Xenopus oocytes.

OBJECTIVE: To investigate the effects of free radicals (FRs) and amyloid beta protein 1-40 (A beta 1-40) on the functions of expressed neurotransmitter receptors (NRs) in Xenopus oocytes. METHODS: Total RNA and messenger RNA (mRNA) was prepared from 3-month-old Wistar rat brain tissues with Promega kits and microinjected into maturated Xenopus oocytes (stages V-VI) with 50 nl (50 ng) for each oocyte. The microinjected oocytes were incubated with modified Bath's solution at 19.0 degrees C +/- 1.0 degree C for receptor expression and their currents were recorded with double electrode voltage clamp technique. Superoxide anion free radicals (SAFRs) were produced via a reaction system (HPX/XO) with hypoxanthine (HPX, 0.05 mol/L) and xanthine oxidase (XO, 0.1 U/L). In order to observe the effects of A beta and SAFRs on the expressed glutamate receptor, HPX/XO and A beta 1-40 were added to incubation solution at 12 h, 24 h and 96 h before recording. RESULTS: The results showed that the oocytes expressed functional NRs originating from rat brain tissues. These NRs included muscarinic acetylcholine (mACh), glutamate (Glu), dopamine (DA), serotonin (5-HT) and gamma-aminobutyric acid (GABA). The current characteristics of expressed receptors were inward currents carried by chloride ion with their equibrilium potentials close to -22 mV. The extent of effect on the current of expressed glutamate receptor from rat brain was different among different A beta concentrations and incubation times. A beta 1-40 at a concentration of 20 nmol/L had little effect on the currents of expressed rat brain glutamate receptors up to 24 h of incubation period; but the currents of glutamate receptor were significantly decreased (25% off, P < 0.01) in the treatment of 60 nmol/L A beta 1-40 over 24 h. Moreover, when 20 nmol/L A beta 1-40 was co-incubated over 12 h with SAFRs produced by the reaction system of HPX/XO, it was found that the currents of expressed rat brain glutamate receptors had been changed markedly. When the oocytes were co-treated with 60 nmol/L A beta 1-40 and SAFRs over a period of 12 h, the currents of glutamate receptor significantly decreased (21% off, P < 0.05), and the decreased percentage reached 52% over 24 h co-treatment with 60 nmol/L A beta 1-40 and SAFRs. In addition, vitamin E had a partial effect against this inhibitory effect. CONCLUSION: The results suggest that A beta has a kind of inhibitory effect upon the current of the glutamate receptor, similar to the effects of free radicals. The effects can be antagonized by vitamin E. These imply that A beta may play a role via inhibiting receptor function in the pathophysiology of Alzheimer's disease.

Amyloid beta-Peptides↗

PubMed2001

Angiotensin II type-1 receptor antagonist, CS-866, reduces blood pressure without affecting glucose/insulin metabolism in cholesterol-fed rabbits.

CS-866 is an angiotensin II type-1 receptor antagonist, the effects of which on systolic blood pressure (BP) and glucose/insulin metabolism are investigated under hyperlipidaemic conditions produced by cholesterol feeding. Thirty-two female Japanese White rabbits (two months old) were assigned randomly into a CS-866-treated group (n = 17) fed a food admixture that contained 0.03% CS-866 and 0.2% cholesterol, or into a control group (n = 15) fed a food admixture containing 0.2% cholesterol only. Systolic BP was measured by an ear-cuff method. Glucose and insulin metabolism was characterised quantitatively from the results of an intravenous glucose tolerance test by a minimal model technique reported previously. After six months treatment, systolic BP in the CS-866-treated group was lower than in the control group (105 +/- 14 mmHg versus 115 +/- 18 mmHg; P <0.05), as assessed by analysis of variance and the Wilcoxon rank-sum test. No significant differences were seen in plasma aldosterone concentration, plasma renin activity, or angiotensin-converting enzyme activity between the groups. Administration of CS-866 for six months did not affect either glucose tolerance or insulin sensitivity. Other model parameters such as basal (steady-state) insulin and glucose concentration, first- and second-phase post-hepatic insulin delivery to glucose, and insulin clearance rate constant were unaffected. In conclusion, CS-866 treatment reduced systolic BP without affecting glucose/insulin metabolism under hyperlipidaemic conditions produced by cholesterol feeding.

Angiotensin Receptor Antagonists↗

PubMed2001

Protective effect of ischemic preconditioning on liver.

OBJECTIVE: To study the protective effect of ischemic preconditioning (IPC) on the hepatic ischemia reperfusion injury. METHODS: The model of rat liver subjected to ischemia/reperfusion (I/R) injury was made. All 24 mice were divided randomly into 3 groups and anesthetized by 2% sodium pentobarbital (30-40 mg/kg). The enzyme activity of AST, ALT, LDH, SOD and the content of LPO were assayed respectively. Specimens were observed under transmission electron microscope. RESULTS: IPC prevented the increase of ALT, AST and LDH in the blood and that of LPO in the tissues (P<0.05), and maintained high level of SOD in the tissues (P<0.05). CONCLUSIONS: IPC has protective effect on the liver function.

Animals↗

PubMed2001

[A clinical investigation on the relationship between nitric oxide and elevation of intraocular pressure in glaucoma].

OBJECTIVE: To investigate the role of nitric oxide (NO) in the process of intraocular pressure (IOP) elevation in glaucoma. METHODS: The levels of NO in plasma and in aqueous humor which were obtained from 16 patients with acute angle closure glaucoma (10 female, 6 male), 29 cases with cataract (13 female, 16 male) and 30 normal volunteers (13 female, 17 male) were detected by high performance liquid chromatography and expressed with the total NO(2) and NO(3). RESULTS: It was found that the mean level of NO in the plasma in glaucoma group was (l,390.78 +/- 302.95) ng/L that was significantly lower than that in the normal group (2 969.37 +/- 862.85) ng/L (t = 2.853, P < 0.01). But in cataract group it was (4,234.89 +/- 1,495.23) ng/L that was significantly higher than that in the normal group (t = 4.471, P < 0.01). There was no significant difference in the level of NO in the aqueous humor between glaucoma group (2,052.03 +/- 694.74) ng/L and normal group (1,405.83 +/- 602.70) ng/L (t = l.862, P > 0.05). But in cataract group the mean level of NO (2, 454.67 +/- 655.13) ng/L in the aqueous humor was increased remarkably in comparison with that in the normal group (t = 2.752, P < 0.01). The rate of the mean content of NO in normal aqueous humor and plasma (aqueous/plasma) was 47.3%, and that in cataract group, 57.96% (P > 0.05). But in glaucoma group, the rate was 144.0%. CONCLUSION: The content of nitric oxide in the plasma and aqueous humor is related to the elevation of IOP in cases with acute angle closure glaucoma.

Aged↗

PubMed2001

High-throughput techniques for compound characterization and purification.

A new paradigm in drug discovery is the synthesis of structurally diverse collections of compounds, so-called libraries, followed by high-throughput biological screening. High-throughput characterization and purification techniques are required to provide high-quality compounds and reliable biological data, which has led to the development of faster methods, system automation and parallel approaches. This review summarizes recent advances in support of analytical characterization and preparative purification technologies. Notably, mass spectrometry (MS) and supercritical fluid chromatography (SFC) are among the areas where new developments have had a major impact on defining these high-throughput applications.

Chromatography↗

PubMed2001

[Bone-inducing activity of human bone morphogenetic protein-2 102 peptide].

To analyze the bone-inducing activity of C terminal of hBMP-2 and get a new recombinant product of hBMP-2, the gene encoding 102 aa of hBMP-2 mature peptide C terminal was cloned and expressed in E. coli and the first Cys was mutated with Ser. The fragments encoding the target peptide were amplified and cloned into heat-inducible expression vector pDH and transformed into E. coli DH5 alpha. After induction, a new protein bond appeared on the SDS-PAGE. The expressed products amounted to 30% of the total bacterial protein, which existed in the form of inclusion body. The products of bacterial lysates were purified through the ion-exchange chromatography. The denatured proteins were dialysed and diluted directly into the refolding buffer. The renatured products were implanted into mouse thigh muscles to analyze their bone-inducing activity respectively. The results of histological assay showed that the 102 peptide of hBMP-2 could ectopically induce formation of bone, while the mutated 102 peptide of hBMP-2 could not. It suggested hBMP-2 102 peptide still had bone-inducing activity. The first Cys of hBMP-2 mature peptide might be necessary for integrity of three pairs of disulfide bond, and also essential for bone-inducing activity of hBMP-2.

Animals↗

PubMed2001

[Analysis and applications of a PrP antibody elicited by synthesized human PrP peptides].

BACKGROUND: To further study the immuno-reactivity and specificity of a PrP antibody elicited by synthesized human PrP peptides. METHODS: Construction of a plasmid which expresses a N-terminus deleted human PrP protein and purification of this truncated protein. The prepared PrP antibody was tested for reaction with various prokaryotic expressed human PrP proteins,including the full-length protein,the N-terminus-and C-terminus-truncated proteins with Western blot. The antibody was also used in the immunofluorescence assays to identify the PrP proteins expressed from the cell lines transfected with human PrP genes. Moreover,the brain tissues from scrapie agents-infected hamsters and a CJD patient were extracted and the proteinase K-resistant PrP-res were analyzed with the prepared antibody. RESULTS: The PrP-peptide elicited antibody could recognize both prokaryotic and eukaryotic expressed human PrP proteins, as well as the PrP-res proteins in the brain tissues both from the scrapie-infected hamsters and CJD patient. CONCLUSIONS: The tested antibody possesses eligible immuno-reactivity and specificity and can be used for diagnosis of CJD in the clinical work.

Animals↗

PubMed2001

[Developmental toxicity of Al(NO3)3 on rat embryos].

The developmental toxicity and its mechanism of Al(NO3)3 on embryos in SD rats were studied. On the 9.5th day of gestation, the embryos were incubated in a whole-embryo culture system with Al(NO3)3 at concentrations of Al3+ from 0.6 to 9.0 micrograms/ml in culture media for 48 hrs. Viable embryos were evaluated by Brown's morphological scoring system, and the diameter of yolk sac, crown-rump, head length and the dry weight of embryos were measured. There was a dose-dependent relations of decreasing embryo development with increasing concentrations of Al3+. Yolk sac diameter, head length, dry weight and heart, forelimb as well as neural tube scores decreased significantly at 1.2 micrograms/ml (P < 0.05). When embryos were exposed to Al3+ at > or = 3.0 micrograms/ml, the embryonic development and morphological differentiation were obviously inhibited(P < 0.05); meanwhile, the incidence of dysmorphogenesis significantly increased, including neural tube defects and dorsiflexion teratogenesis. The results suggested that aluminum might be a developmental toxicant and dysmorphogenesis agent.

Aluminum Compounds↗