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Biomedical subjects

L Zhang

Publications and source records attributed to L Zhang.

At least 505 records · Page 28Linked to original sources
PubMed2001

[Production of transgenic lamb integrated with modified human anti-trypsin gene].

This experiment is to produce the human mAAT(modified anti-trypsin) which cures the emphysema specifically through mammalian galactophore of transgenic goat. 56 goats were selected as donor for superovulation by FSF + LH microinjection in this experiment. The pronucleic embryos were injected with human mAAT gene after fertilization in vivo, and transferred to the donors or receptors directly. The superovulation was better in March and May than in December with the number of ovulation of 19.50, 21.70 and 16.06, and number of fertilized embryos of 4.31, 6.48 and 3.57 per-animal respectively. The pregnant rates were 18.18% and 25% respectively after transferred to donors and receptors with natural estrus. The donors also can be used as the embryo receptor with no remarkable decrease of pregnant rate. 29 lamb were labored. 4 positive transgenic lamb were checked by PCR, PCR-Southern and Southern analysis. The integrated efficiency of foreign DNA was 13.79% with microinjection of high copy number of foreign DNA fragment.

Animals↗
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

[An investigation of the bio-tribological performance of diamond-like carbon/ultrahigh molecular weight polyethylene couple].

OBJECTIVE: To evaluate the friction property of diamond-like carbon (DLC) film/Ti6Al4V gradient material sliding against UHMWPE couple. METHOD: Tests of this couple were made under dry sliding and lubrication of Hank's solution and 0.9% NaCl solution respectively, and they were compared with the friction property of Ti6Al4V sliding against UHMWPE couple. The tests were performed on an SRV friction and wear tester by means of surface-contact and coefficients of friction were recorded real-time. RESULT: DLC film could reduce the friction coefficient evidently. The coefficients of friction reduced 24%, 5.0%, 10% than these of Ti6Al4V under dry sliding and lubrication of Hank's solution and 0.9% NaCl solution respectively. Mechanism of friction was also studied by observing scanning electrical microscopy (SEM) morphology of frictional surfaces. CONCLUSION: Friction-reduction mechanism of DLC film/Ti6Al4V could be resulted from amorphous structure of DLC film which was smooth and hard.

Biocompatible Materials↗
PubMed2001

[Determination of +Gz tolerance end-point by steady state visual evoked potential].

OBJECTIVE: To study the possibility of applying steady-state visual evoked potential (SSVEP) to detect the end-point of +Gz tolerance. METHOD: When a subject was exposed to +Gz acceleration on a human centrifuge, the SSVEP signals (evoked by LED lamps triggered by 8 Hz pulse train) were recorded. The characters of SSVEP in frequency domain were extracted by adaptive filtering, and a modified T2circ statistic was used to determine the visual obstruct objectively. RESULT: SSVEP had strong relationship with visual obstruct of the subjects during +Gz exposure. CONCLUSION: SSVEP might be used as an objective criterion for determination of end-point of +Gz tolerance and an index of the degree of symptoms as well. But, multi-parameter method seemed still necessary to get reliable estimations.

Acceleration↗
PubMed2001

[Studies of the determination of glycyrrhizin acid kali salt by HPLC and the pharmacokinetics].

To find a practive and quick method determining GK concentration in blood by HPLC and to study its pharmacokinetics. GK from Glycyrrhiza uralensis Fisch was extracted and purified. GK were administered to mice by i.v. and ig. The Concentration of GK in blood at expected time was determined by HPLC. The data was dealed with by 3 P 87 programe. The concentration-time curve of i.v. 0.1% GK 40 mg/kg is in accordance with tow-compartment model. t1/2 alpha = 5.128 min, t1/2 beta = 51.196 min, AUC = 7477.642 (micrograms/ml).min, Cl(s) = 0.0956 microgram/min(microgram/ml). The c-t curve of ig. 2.2% GK 500 mg/kg is in accordance with tow compartment model, t1/2 alpha = 15.97 min, t1/2 beta = 200.05 min, AUC = 2453.96(micrograms/ml).min, Cl(s) = 3.642 micrograms/min(micrograms/ml). HPLC is a quick and practive method to determin the concentration of GK in blood.

Animals↗
PubMed2001

Experiences from a collaborative project on the prevention of disability in leprosy patients in Shandong Province, the People's Republic of China.

Shandong Province (present population 89 million) in the People's Republic of China established a leprosy control programme in 1955. Between that year and the end of 1999, allowing for death and migration, the cumulative number of cases registered was 53,618, including 120 cases on multiple drug therapy (MDT) and 18,248 who had completed satisfactory courses of dapsone monotherapy and/or MDT. Of this latter group, 9500 cases (52%) suffered from visible disabilities (grade 2 of the WHO classification). Prevalence and incidence rates of leprosy have decreased dramatically since 1955 and, on average, only 50-70 new cases are now being detected annually in the entire province. Leprosy is thus no longer a public health problem, but the existence of such a large number of patients with grade 2 disabilities is clearly a matter of serious concern. This paper describes a pilot project to investigate the potential of health personnel in the leprosy programme and the dermatology and sexually transmitted diseases services to (a) prevent deterioration of existing disabilities in ex-patients through self-care and (b) prevent new neuritis in patients on MDT through early detection and the use of steroids.

Adult↗
PubMed2001

[Analysis of inductive factors, diagnosis and treatment of 21 cases with pregnancy accompanied with pulmonary edema].

OBJECTIVE: To investigate the inductive factors, the prevention and treatment methods of pulmonary edema during pregnancy. METHODS: The clinical materials of 21 cases of pregnancy with pulmonary edema treated in our hospital from Jan. 1985 to Jan. 2000 were analysed retrospectively. RESULTS: Among 21 patients, 26 pulmonary edema attacked, 9 of them had upper have respiratory diseases, thirteen cases caused by improper infusion. Fourteen cases were well controlled quickly with antiplasm nifedipine, myocardial strength and diuretics. If the symptoms could not be controlled properly, vasodilators were applicated. We had 16 cesarean section under epidural anaesthesia, one vaginal birth, and the other one birth by forceps. CONCLUSIONS: Pulmonary edema in pregnancy usually followed with acute heart failure caused by sever pregnancy induced hypertension. We should pay more attention to the indications of it. During treatment, we should give vasodilators properly, so as to prevent pulmonary edema.

Adult↗
PubMed2001

Lake sediment resuspension and caused phosphate release--a simulation study.

Intact sediment cores and wet/dried surficial sediments sampled from the two sublakes in Taihu Lake, Meiliang Bay and Wuli Lake, were incubated in the laboratory to determine the effects of resuspension on internal phosphorus loading by simulating different resuspension events. Soluble reactive phosphorus (SRP) release from undisturbed core sediment sampled in the Meiliang Bay and Wuli Lake in July 1998 was 1.53 mg/m2 and 2.24 mg/m2 within 4 days, respectively. However during one hour experimental simulation of resuspension, SRP increased by 0.041 mg/L and 0.077 mg/L in the above cores, which indicate that a typical resuspension event in the lake would be accompanied by the release of 10.77 mgSRP/m2 and 23.1 mgSRP/m2, respectively. The internal phosphorus loading induced by resuspension is estimated to be 8-10 times greater than the release from undisturbed sediment. SRP release from the dried sediments during simulation of resuspension was mainly dependent on the disturbing intensity. Only when the wind strength gets to certain level, the influence of wind speed on phosphorus release appears significant, indicating that an exchangeable P pool, capable of altering equilibrium conditions in the lake areas, is built up under strongly wind-exposed resuspension events.

Geologic Sediments↗
PubMed2001

Enteric transmission of transfusion-transmitted virus.

OBJECTIVE: To detect the virus in the feces and sera of patients in an outbreak of enterically transmitted non-A, non-E hepatitis, and this review covers the epidemiologic features and experimental infection of this novel virus. DATA SOURCES: Data sources come from our own work on this subject, published and unpublished. STUDY SELECTION: Mainly our own work is included, and related literature is collected. RESULTS: In an outbreak of enterically transmitted non-A-E hepatitis among students, a total of 381 cases (60.7%) were documented. Viral fragments identical to transfusion transmitted virus (TTV) were detected in both serum and stool samples. Asymptomatic virus carriers among the staff had positive serum (32.1%) and feces (24.6%), clearly a potential source of infection. This viral infection prevalence in 2 remote villages in northern and southern China was 9.2% and 10.6%, respectively, suggesting that China is an endemic area. In this study, groups of 3 Rhesus monkeys were infected via oral or intravenous inoculation with patient feces. Two additional monkeys were infected by passage. The virus was detected in serum, peripheral blood mononuclear cell (PBMC), liver, spleen and small intestine, while the virus positive single strand, which might be a replicative intermediate, was only in liver, intestine and PBMC of all animals. CONCLUSIONS: This nonenveloped DNA virus might be transmitted both by blood and enteric routes. Considering its wide distribution and high prevalence, we suppose that nonparenteral transmission is more important.

Animals↗
PubMed2001

Developmental morphology of blood and lymphatic capillary networks in mammalian hearts, with special reference to three-dimensional architecture.

The development of blood and lymphatic capillaries in the cardiac ventricles was studied using the rat and monkey hearts from later gestation to adulthood. For scanning electron microscopy, the tissue was treated with ultrasonication followed by HCl in order to remove epicardial mesothelial cell, subepicardial connective tissue and basement membrane. At the end of fetal life and neonate, the blood capillaries ran in parallel between the bundles consisting of several cardiac myocytes with small size. Endothelial extensions were found frequently. Numerous pericytes with short processes were observed on the capillary wall. Blood capillaries in the pubertal myocardium ran between cardiac myocytes to form a dense network. Processes of pericytes became elongated along the capillaries. In the adult, the capillaries showed occasionally Y-shaped branching and H-shaped anastomoses. The lymphatic capillaries were identified by large, variable sizes and absence of pericytes. In early postnatal rats, they appeared in the subepicardial region. In young and adult animals, the lymphatic capillary networks with relatively dense reticular meshes surrounded the bundles of several myocytes. It was noted that numerous nerve fibers were in close to the lymphatic capillary wall.

Aging↗
PubMed2001

Effect of lysophosphatidylcholine on expression of vascular endothelial growth factor in ECV304 cells.

AIM: To determine the effect of lysophosphatidylcholine (LPC) on the expression of vascular endothelial growth factor (VEGF) in human umbilical veins endothelial cell line (ECV304). METHODS: VEGF protein production from ECV304 cells was determined by enzyme-linked immunosorbent assay (ELISA). VEGF protein and its receptor were also examined by immunohistochemical staining. After culturing for 24 h with LPC, VEGF mRNA expression in ECV304 was examined by in situ hybridization. RESULTS: Cultured ECV304 cells could express VEGF receptor and a strong expression of VEGF receptor was induced by LPC 5 mg/L. LPC upregulated VEGF protein secreted from the ECV304 cells in a time- and concentration-dependent manner and LPC also stimulated VEGF mRNA expression in the ECV304 cells. CONCLUSION: LPC could induce a strong expression of VEGF in ECV304 cells.

Cell Line↗
PubMed2001

Effect of scopoletin on PC3 cell proliferation and apoptosis.

AIM: To investigate the effect of scopoletin on cell proliferation and apoptosis of PC3 cells. METHODS: Cell growth curve, MTT assay, and acid phosphatase activity (ACP) were used to determine cell proliferation. Coomassie brilliant blue assay was used to measure the content of protein in cells. Light microscope, transmission electronmicroscope, and fluorescence microscope were used to observe scopoletin-induced morphological changes. Apoptosis rate and cell cycle distribution were determined by flow cytometry. RESULTS: The IC50 of scopoletin for inhibiting PC3, PAA, and Hela cell proliferation was (157 +/- 25), (154 +/- 51), and (294 +/- 100) mg/L, respectively. Scopoletin induced a marked time- and concentration-dependent inhibition of PC3 cell proliferation. Scopoletin reduced the protein content and decreased the ACP level in PC3 cells in a concentration-dependent manner. Cells treated by scopoletin showed typical morphologic changes of apoptosis by light microscope, fluorescence microscope, and transmission electronmicroscope. Apoptosis rate was 0.3 %, 2.1 %, 9.3 % and 35 % for scopoletin 0, 100, 200, and 400 mg/L, respectively, and cells in G2 phase decreased markedly after being treated with scopoletin. CONCLUSION: Scopoletin inhibited PC3 proliferation by inducing apoptosis of PC3 cells.

Apoptosis↗
PubMed2001

[Effect of soil moisture and wetting-drying on Mn release in Ca(NO3)2-amended soils].

A study on the effects of two moisture levels (200 and 400 g.kg-1) and wetting-drying on the solubility of Mn in Ca(NO3)2-amended soils showed that water regime was a factor affecting Mn availability. Easily reducible Mn was transformed into soluble and exchangeable Mn, when soil water content was high. Salt had a definite effect on the transformation of easily reducible Mn. NO3- could decrease soil redox potential, and inhibit the transformation of easily reducible Mn. Wetting-drying significantly(alpha < 0.05) decreased the content of soil water-soluble and exchangeable Mn, while Ca(NO3)2 increased the insolubility of Mn, which might eventually lead to the deficiency of soil Mn.

Calcium Compounds↗
PubMed2001

[Association between dopamine transporter gene polymorphism and Parkinson's disease].

OBJECTIVE: To detect the association between dopamine transporter gene polymorphism and Parkinson's disease (PD). METHODS: The authors analyzed the difference in the distribution of the variable number tandem repeat (VNTR ) polymorphism within the 3' untranslated region of the DAT gene between 85 normal controls and 128 PD patients that were further divided into the senile subgroup (aged >50 years at onset of PD ) and the early-onset subgroup (aged </=50 years). RESULTS: There were significant differences in genotypic and allelic distribution between the control group and the PD group. The senile PD was strongly associated with the 7-copy allele and weakly with the 10-copy allele, and the early onset PD was mainly associated with the 9-copy allele. CONCLUSION: The findings not only support an association between DAT gene and PD but also suggest the relationship of the 3'VNTR polymorphism of DAT gene with the age at the onset of PD.

Adolescent↗
PubMed2001

Chimera formation of platelet GP II b Bak a/b by intrauterine transplantation of fetal liver stem cells.

OBJECTIVE: To investigate whether artificial heterozygous chimeras of platelets can be established by intrauterine transplantation of fetal liver stem cells and evaluate its potential use for the treatment of Glanzmann thrombasthenia. METHODS: Platelet glycoprotein (GP) II b Bak a/b (or GP II b I le843Ser) was used as a genetic marker. A homozygous 16-week-old Bak a/a fetus (as donor) and a homozygous 16.5-week-old Bak b/b fetus (as recipient) were screened from 42 pregnant women hospitalized for abortion. PCR with allele specific primers and FOK I digestion based on PCR products were used. Aborted donor fetal liver cell suspensions were prepared and intrauterine transplantation was carried out by infusion of 4 ml fetal liver cells (22 x 10(5)) into the recipient umbilical vein under ultrasonic visualization. RESULTS: At gestation termination (abortion), 21 days after transplantation, chimera GP II b Bak a/b of the recipient were detected by FOK 1 digestion based on PCR from DNA and RT-PCR from platelet RNA. CONCLUSION: Intrauterine transplantation of fetal liver cell may provide an effective way for curing GT or other inherited diseases.

Adult↗
PubMed2001

Th1/Th2 type cytokines in hepatitis B patients treated with interferon-alpha.

OBJECTIVE: To investigate the relationship between the expression of Th1/Th2 type cytokines and the effect of interferon-alpha therapy. METHODS: Th1/Th2 type cytokines were assayed by enzyme-linked immunosorbent assay (ELISA) and reverse transcription polymerase chain reaction (RT-PCR) on 23 patients with chronic hepatitis B who were treated with interferon-alpha. RESULTS: Levels of IFN-gamma in the supernatant of peripheral blood mononuclear cells (PBMC) cultures from the patients with hepatitis B were slightly lower than those of controls (P = 0.07). However, the levels of IL-4 were higher than those of controls (P = 0.01). Cytokines measurements during IFN-alpha treatment showed a trend to decreasing levels of IL-4 at 4, 12, and 24 weeks. Levels of IFN-gamma were slightly increased following IFN-alpha treatment (P = 0.09). In patients with a complete response to IFN-alpha, the levels of IFN-gamma were higher at 24 weeks following IFN-alpha treatment than that of pre-treatment (P = 0.04), and the levels of IL-4 decreased markedly at 12 and 24 weeks (P = 0.02, 0.03, respectively). mRNA expression positively correlated with the level of Th1/Th2 type cytokines in the supernatant. CONCLUSION: The expression of Th2 type cytokines is predominant in patients with chronic hepatitis B. Interferon-alpha therapy can modulate the balance of Th1/Th2 type cytokines, and this is related to its clinical effect. Levels of Th1/Th2 type cytokines could be a predictor of clinical response during Interferon-alpha treatment.

Antiviral Agents↗