Biomedical subjects

Z Wang

Publications and source records attributed to Z Wang.

At least 415 records · Page 23Linked to original sources

PubMed2001

[Role of protein kinase in the proliferation of human embryonic pulmonary fibrolasts stimulated by the supernatants of crocidolite-exposed alveolar macrophages].

In order to study the role of protein kinase in the proliferation of lung fibroblasts induced by crocidolite. An in vitro model was established by rabbit alveolar macrophage (AM) and human embryonic pulmonary fibroblasts (HEPF). Using MTT color response method to measure HEPF proliferation, the influence of the inhibitor or activator of protein kinase (PKA, PKC and TPK) on the proliferation of crocidolite-induced HEPF were investigated. TiO2 was taken as negative control and SiO2 positive control. The results showed that the inhibitors of PKA, PKC and TPK could all inhibit the proliferation of HEPF induced by crocidolite, their activators could also promote the proliferation of HEPF. There all existed significant dose-effect relationships (P < 0.01), and the intensity in crocidolite group was inhibited or activated more than that in the controls. Through acting intensity analysis, the intensity was found as follows: TPK > PKC > PKA. It was suggested that TPK, PKC and PKA signal pathways were all involved in the process of the proliferation of crocidolite-induced HEPF, but TPK maybe played a key role in this process. This study provide leads for further research on identifying the bioactive factors of proliferation of crocidolite-induce HEPF.

Animals↗

PubMed2001

Genotype and severity of long QT syndrome.

Sudden cardiac death occurs in the United States with an incidence greater than 300,000 persons per year. The underlying cause of death is commonly considered to be due to primary or secondary arrhythmias. In cases in which no structural heart disease can be identified, the long QT syndromes (LQTS) are now commonly considered as likely causes. Multiple genes causing LQTS have been identified thus far, all encoding cardiac ion channels. These include two potassium channel alpha-subunits (KVLQT1, HERG), two potassium channel beta-subunits (minK, MiRP1), and one sodium channel gene (SCN5A). The purpose of this review is to describe the current understanding of the molecular genetics of LQTS and the resultant phenotypes.

Chromosome Mapping↗

PubMed2001

[Relationship between the dynamic expression of scavenger receptor on Kupffer cells and endotoxin-induced hepatic injury].

OBJECTIVE: To observe the change of scavenger receptor (SR) expression on Kupffer cells and study its role in pathogenesis of liver injury in mice. METHODS: 1mg/kg or 10 mg/kg of E.Coli 026: B6 LPS was bolus injected via i.a.to reproduce an animal model for this experiment. The change of SR on Kupffer cells was determined with immunohistochemistry. TNF-alpha and IL-6 level in hepatic tissue were assayed using ELISA. RESULTS: The expression of SR on Kupffer cells was aggressively downregulated in a LPS does dependent fashion. TNF-alpha, IL-6 level in hepatic tissue and ALT, TBIL in plasma were significantly negatively correlated with the expression of SR. CONCLUSIONS: With the down-regulation of SR expression on Kupffer cells, the clearance of endotoxin by Kupffer cells is decreased and the activation of Kupffer cells by endotoxin is accordingly enhanced. SR expression is closely related to hepatic injury.

Animals↗

PubMed2001

Field monitoring of toxic organic pollution in the sediments of Pearl River estuary and its tributaries.

Field monitoring of the toxic organic compounds (PCBs, PAHs, organochlorine pesticides) in the top sediments of Pearl River Estuary and its up-streams were made. It was found that the highest concentrations of these toxic organic compounds occurred in the sediment sampled at Macau inner harbor (ZB013), which is a sink of suspended fine particles transported from the upstream waterways. Because of the affinity of the hydrophobic organic compounds (PAHs, PCBs) for the solid phase, these fine particle depositions led to accumulation of these compounds in the sediment of Macau. The atmospheric dry deposition may be another source of the toxic organic pollution in the sediment.

Air Movements↗

PubMed2001

[Removal of TOC and Ames mutagens from drinking water using AC-NF process].

Expermental results of the effect and mechanism of removing TOC and Ames mutagens from drinking water using AC-NF process showed that the adsorptive ability of AC was limited, depending on the characters of AC and the organic matters in drinking water. But AC can be used as the pretreatment of NF to ensure to meet the requirement of membrane feed. NF can remove the majority of total organic carbon and Ames mutagens effectively to ensure the safety of drinking water. The MR values of TA98 and TA100 of NF permeate were below 2 under the tested doses, and the results of Ames test of NF permeates were completely negative. Therefore, it is feasible to combine AC and NF to obtain the high-grade drinking water.

Charcoal↗

PubMed2001

[Study on interactions between TPO molecules tested with yeast two-hybrid system].

OBJECTIVE: To explore the interactions between TPO molecules and their locations. METHODS: Full-length TPO, TPO(N) and TPO(C) were inserted respectively into the plasmids of the yeast two-hybrid system. Six different recombinant plasmids were generated. Every 2 recombinant plasmids were transformed into the yeast cell SFY526. The possible interactions between TPOs were then tested by the bioactivity of beta-galactosidase. RESULTS: There are interactions between full-length TPO themselves TPO(N) themselves and TPO with TPO(N), but not between TPO(C)themselves, TPO with TPO(C) and TPO(N) with TPO(C). CONCLUSION: Naturally, the molecular interaction domain of TPO may exist in the N terminus but not in the C terminus.

Thrombopoietin↗

PubMed2001

[Quantitative analysis of cell fusion caused by glycoprotein of paramyxoviruses with reporter gene method].

OBJECTIVE: To establish a kind of quantitative assay method for analyzing the reporter gene assay for fusion was established. METHODS: Two populations of BHK21 cells were infected with vTF-7 recombinant and wild-type vaccinia viruses respectively and transfected with paramyxovirus F and HN cDNA and plasmid pG1NT7 beta-gal respectively. After 16 h, the two cell populations were removed from the wells by trypsinization. Equal numbers of the two populations were mixed in wells of a 96-well flat-bottom plate after washing and pelleting. After 15 hours' incubation at 37 degrees C, the cells were lysed with Nonidet P-40 and A values were read at 570 nm with an ELISA reader supported by SOFTMAX software. RESULTS: Reporter gene method had a close relationship with cell count method, r = 0.9890(P < 0.01). Positive and negative coincidence rates were 100%. The best main reaction conditions are as follows: substrate concentration, 16 mmol/L; color reaction time, 20-25 min; amount of DNA for transfection, 1 microgram; cell numbers for each population, 1 x 10(5). CONCLUSION: Reporter gene method is a kind of very sensitive, specific and repeatable quantitative analysis for cell fusion and can be used in the studies on membrane fusion caused by any viruses.

Cell Fusion↗

PubMed2001

[Study of EEG processing system and EEG wavelet transform].

In this paper are reported our studies on the time and frequency characteristics of wavelet transform, the EEG signals processing through wavelet transform, the EEG analysis and reconstruction results. The related EEG processing system design and implementation are given in detail. This system may be applied to EEG feedback research and EEG monitoring.

Computers↗

PubMed2001

[Using self-assembled monolayers to understand the interactions of surfaces with cells].

It is important to understand the interactions of surfaces with cells. Self-assembled monolayers formed on the adsorption of long-chain alkanethiols to the surface of gold or alkylsilanes to hydroxylated surfaces and their patterned surfaces permit of understanding and controlling over the surface-cell interactions at the molecular scale. The present paper reviewed the latest research in using patterned self-assembled monolayers to understand surface-cell interactions.

Alkanes↗

PubMed2001

[Effects of phenytoin on structural aberration of human sperm chromosomes in vitro].

OBJECTIVE: To detect the mutagenic effects of phenytoin on human sperm chromosomes. METHODS: The mutagenic effects of phenytoin at 10, 20 and 40 microgram/ml were tested by an in vitro testing system of human sperm chromosomes, with leomycin A5 as a positive control and mutagen-free solution as the blank control. RESULTS: The frequencies of sperm with structural chromosomal aberrations and breakages of sperm chromosomes in the groups of 10 microgram/ml, 20 microgram/ml and 40 ug/ml of phenytoin were all higher than those in the blank control, but only in the group of 40 ug/ml, the elevated frequencies were statistically significant (P<0.005, P<0.05). CONCLUSION: Phenytoin has probably mutagenic potential effect on human sperm cells.

Adult↗

PubMed2001

[Allografting for massive bone defect: bone and soft tissue reconstruction and postoperative rehabilitation].

OBJECTIVE: To evaluate the results of limb function and the methods of bone and soft tissue reconstruction of patients treated with allografting. METHODS: From May 1992 to January 1999, 90 patients suffered from bone malignant tumor were treated with allografting in different methods of internal fixations. The average follow-up was 37.5 months. The limb postoperative function, complications related to different surgical methods were compared according to Enneking evaluation system. RESULTS: Skin necrosis, infection, non-union, fracture of allograft were the main complications which affect patients' limb postoperative functions. Of the 90 fresh-frozen allografting procedures, the final results of operation showed that hip joints and knee joints were better than the shoulder joints. More than 80% of the patients treated with interlocked intramedullary nail and allograft-prosthesis combination led to an over-all result that was excellent and good. Interlocked intermedullary nail was of recommended method of internal fixation. Early exercises of operative limbs could promote function recovery. CONCLUSION: Using of interlocked intramedullary nail and allograft-prosthesis combination are of recommended operation method and can be applied with better results, and early exercises of operative limbs will lead to better functions.

Adolescent↗

PubMed2001

[Changes of lipid peroxidation in liver fibrogenesis induced by dimethylnitrosamine and drugs' intervention].

OBJECTIVE: To investigate the pathological actions of lipid peroxidation implicated in liver fibrogenesis induced by dimethylnitrosamine (DMN), and the mechanism of Fuzheng Huayu 319 decoction (319 decoction) and interferon-gamma (IFN-gamma) actions against liver fibrosis. METHODS: A liver fibrotic model was induced by intraperitoneal injection of DMN in rats, and treated with 319 decoction and IFN-gamma, respectively. The liver sections were stained with HE and ponceau for collagens, and the liver functions were assayed. The contents of hepatic hydroxyproline (Hyp) and malondialdehyde (MDA) and the activities of superoxide dismutase (SOD) were measured. The correlation among SOD, MDA and Hyp was analyzed. RESULTS: In the models, hepatic collagens proliferated remarkably and fibrous septa were formed. Serum ALT activities increased. Both Hyp and MDA enhanced obviously, but SOD decreased markedly. SOD was significantly negatively correlated with MDA and Hyp, respectively (r=-0.70, -0.73, P<0.01), and MDA was significantly positively correlated with Hyp (r=0.88, P<0.01). While both 319 decoction and IFN-gamma attenuated collagen proliferation and deposition, decreased ALT level, increased SOD activity, but decreased MDA and Hyp contents. CONCLUSIONS: DMN can cause hepatic lipid peroxidation, which is closely involved in liver fibrogenesis induced by DMN. The effect against hepatic lipid peroxidation is one of the important mechanisms of 319 decoction and IFN-gamma actions against liver fibrosis.

Animals↗

PubMed2001

[Cloning and sequence analysis of light chain gene of human antibody against HBV pre-S2].

OBJECTIVE: To obtain the gene of light chain of human antibody against HBV pre-S2. METHODS: A human antibody against HBV pre-S2 displayed on phage was obtained from the constructed human immunoglobulin phage displaying library through four rounds panning of "adherence-elution-amplification" with Pre-S2 (120aa-145aa) short peptide synthesized and help phage. The positive clone of anti-pre-s2 was characterized by ELISA competitive inhibition assay. The plasmid from the positive clone was amplified by PCR with designed oligonucleotide primers of kaph light chain. The light chain fragment was amplified with PCR and plasmid pUC18 digested by restriction endonuclease SacI & XbaI, respectively, then it was subcloned into the plasmid pUC18 and was transformed into E.coli XL1-blue sensitized by CaCl2. The recombinant plasmid pUC18-kaph was sequenced. RESULTS: The competitive inhibition rate of the positive clone of anti-pre-S2 was 65% at 1:50 dilution. Sequence was compared with data in gene bank through internet and analyzed with Blast. According to the sequence and ELISA competitive inhibition assay the integral gene of kaph light chain of human antibody against HBV-PreS2 was obtained. Its variable region located on 1-328bp including three hypervariable regions (82-105bp, 145~177bp, 274~309bp) and four frame regions (1-81bp, 106-144bp, 178-273bp, 310-328bp). Its constant region was located on 329-645bp. CONCLUSIONS: The HBV pre-S2 kaph light chain is screened from phage antibody displaying library by antigen-antibody special response.

Base Sequence↗

PubMed2001

[CT appearance and its diagnosis value in liver cancer after transcatheter oily chemoembolization combining with high intensity focused ultrasound therapy].

OBJECTIVE: To study the CT appearances of liver cancer after transcatheter oily chemoembolization (TOCE) combining with high intensity focused ultrasound (HIFU) therapy. METHODS: Fifty cases of clinically-proved liver cancer were included into this study. For each case, CT scanning before and after TOCE, HIFU treatment was performed. The volumes of the masses were measured. The appearances of the oily deposition and the density, shape, border of the lesions were observed. RESULTS: The lesions became smaller in 38 cases (38/50, 76%) after the treatment. The differences were detected statistically in the ratio of the tumor shrinkage between the single TOCE therapy and the combined treatment (P<0.05). The ratio of the tumor shrinkage was closely correlative with the quantity of the oily deposition, but not with the diameter of the tumor before treatment. The lowered densities were showed in 30 cases (30/50, 60%) and the borders became regular and clear in 16 cases after HIFU therapy. CONCLUSIONS: TOCE combining with HIFU therapy in the patients with liver cancer can make the tumor smaller. CT is of great value in the evaluation of efficacy and prognosis.

Adult↗

PubMed2001

[EROD induction in liver microsome of carp(Cyprinus carpio) by nitroaromatic hydrocarbons in vitro].

Nine nitroaromatic hydrocarbons (NAHs) induction of EROD activity was investigated by an in vitro assay based on carp (Cyprinus carpio) hepatic microsome system. All nine NAHs tested were found to induce the activity of EROD. There was dose-effect relationship between EROD activity and concentrations of NAHs. It was found that EROD activity was different, when different groups substituted at the same position of benzene ring, or the same group was at different position of benzene ring.

Animals↗

PubMed2001

Systematic analysis of bulk blue ballpoint pen ink by FTIR spectrometry.

A classifying method on bulk blue ballpoint pen ink has been studied by Fourier transform infrared (FTIR) spectroscopy. By using this method, a total of 108 blue ink samples have been divided into two groups depending on their main component. Spectral characteristics of these inks such as frequency and absorbance are described by way of artificial intelligence of pattern recognition, and 35 subgroups from the 108 inks are distinguished by their correlation coefficient (lambda). Under heat or exposure to ultraviolet light a mode of change in the age of the inks has been obtained. This approach has provided a reliable and nondestructive method for the characterization of bulk ballpoint writing ink, and more importantly, it might be a basis for dating of the blue ballpoint pen ink.

Journal Article↗

PubMed2001

Rapid detection and differentiation of Newcastle disease virus isolates by a triple one-step RT-PCR.

A triple one-step RT-PCR was developed to screen and differentiate virulent from avirulent Newcastle disease virus (NDV) isolates. Three sets of oligonucleotides were designed, each specific for amplifying NDV fusion protein gene-specific RNA from virulent, avirulent or all isolates respectively. The sensitivity of one-step RT-PCR was determined using viral RNA extracted from serially diluted NDV-infected allantoic fluid and found to be 10(-5) HA units. Application of one-step RT-PCR to various NDV samples, including wild-type virulent isolates and avirulent vaccine strains, demonstrated the potential for rapid identification (3-4 h) of NDV isolates as well as the differentiation of virulent from avirulent strains.

Animals↗

PubMed2001

[Effects of emodin on hepatic fibrosis in rats].

OBJECTIVE: To investigate the effect of emodin on hepatic fibrosis in rats and study its possible mechanism. METHODS: The rat hepatic fibrotic model was induced by the subcutaneous injection of 40% CCl(4) (twice a week for 6 weeks). The fibrotic rats were treated with low-dose, mediate-dose and high-dose emodin (20, 40 and 80 mg/kg body weight, once a day for 42 days). Liver function, serum hyaluronic acid, laminin, and liver hydroxyproline were determined, Histopathological changes were examined by optical microscopy. The expression of alpha-smooth muscle actin (alpha-SMA) in liver tissue were detected by immunohistochemical techniques. RESULTS: Compared with model group, it revealed that in emodin-treated rats: (1) Liver functions was improved, alanine transaminase (ALT) and alkaline phosphatase (AKP) obviously reduced (P<0.05 or <0.01), total protein (TP) and albumin (ALB) significantly increased (P<0.05 or <0.01). (2) Serum hyaluronic acid and laminin markedly reduced (P<0.05 or <0.01). (3) Liver hydroxyproline were significantly decreased (P<0.05 or <0.01). (4) The degrees of fibrosis were reduced (P<0.05). (5) The expression of alpha-SMA in liver tissue were ameliorated. CONCLUSIONS: Emodin has an effect on hepatic fibrosis in rats. The effect may be related to slowing hepatocyte injury and inhibiting liver alpha-SMA expressions.

Actins↗