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Biomedical subjects

H Zhang

Publications and source records attributed to H Zhang.

At least 451 records · Page 25Linked to original sources
PubMed2001

[Meta-analysis of risk factors on lung cancer in non-smoking Chinese female].

OBJECTIVE: To evaluate the risk factors of lung cancer in non-smoking Chinese women. METHODS: The results of 7 case-control studies from 1990 to 1999 were analyzed by Meta-analysis method in this study. The cumulative cases and controls were 1 115 and 1 520, respectively. Der Simonian and Nan Laid model were applied to process data. RESULTS: The pools OR values of family history of lung cancer, personal history of non-neoplastic lung disease, cooking oil fume pollution, coal pollution and exposure to environmental tobacco smoking (ETS) were 2.87, 2.79, 2.52, 1.42 and 1.64 respectively. CONCLUSION: Family history of lung cancer and personal history of non-neoplastic lung disease might serve as the most important risk factors of female lung cancer in China. There appeared also significantly positive relationship between female lung cancer and the degree of cooking oil fume pollution or pollution of coal burning. The effect on lung cancer of exposure to ETS was uncertain in this study which calls for further investigation. Bias and confounding factors were also discussed in this study.

Air Pollution, Indoor↗
PubMed2001

[Preparation of genetically engineered retinal pigment epithelial cells capable of secreting nerve growth factor].

OBJECTIVE: To develop genetically engineered retinal pigment epithelial (RPE) cells which are able to express bioactive nerve growth factor (NGF) steadily and efficiently and to combine gene therapy with retinal transplantation techniques to treat retinal degeneration. METHODS: Replication-deficient retrovirus-plasmid recombinant pLXSN-NGF was constructed via subclone and clone, and then packaged into pT67 cells to obtain virion containing a secretable form of NGF gene. We evaluated titer of the retroviral recombinant with NIH 3T3 cells and then transduced NGF gene into cultured RPE cells by the retroviral recombinant. We also analyzed the expression of NGF gene in transduced and untransduced RPE cells via reverse transcription (RT)-PCR and Western blot. The bioactivity of expressed NGF were evaluated by stimulating PC 12 cells with conditioned medium from transduced and untransduced RPE cells. RESULTS: The titer of replication-deficient retroviral recombinant reached 1.2 x 10(7) cfu/ml. NGF protein and mRNA were detected in the conditioned medium from transduced RPE cells, but not from the normal RPE cells. Marked neurite process outgrowth from PC 12 cells was observed after being stimulated with the conditioned medium from transduced RPE cells. CONCLUSIONS: RPE cells are able to be transduced by replication-deficient retrovirus with high efficiency, and secret bioactive NGF at a high level, which might be an ideal candidate for engineered cells.

3T3 Cells↗
PubMed2001

[The characteristics of bcl-2 and PCNA expression in the lens epithelium of human being].

OBJECTIVE: To investigate the characteristics of bcl-2 (gene inhibiting apoptosis) and proliferating cell nuclear antigen (PCNA) expression and their relation to the proliferation of lens epithelium. METHODS: The expression of bcl-2 and PCNA were detected by immunohistochemical streptavidin-peroxidase (SP) method. RESULTS: The expression of bcl-2 and PCNA in the lens epithelium of fetus and children was higher than that of the elderly, especially in the region of the lens equator. CONCLUSION: The over-expression of bcl-2 and PCNA in the lens epithelium of fetus and children suggests that bcl-2 and PCNA might be related to the development of cataract.

Adolescent↗
PubMed2001

[Gene rearrangement and p53 expression in defining the nature of angioimmunoblastic lymphadenopathy].

OBJECTIVE: To investigate gene rearrangement and p53 expression in defining the nature of angioimmunoblastic lymphadenopathy. METHODS: DNA was extracted from paraffin-embedded tissue blocks of 44 angioimmunoblastic lymphadenopathy (AIL) patients and analyzed with polymerase chain reaction (PCR) for IgH and TCRgamma gene rearrangement. Immunohistochemistry staining was used to detect p53 protein expression. Thirty-five cases were followed-up. RESULTS: 12 out of 44 cases (27.3%) showed TCRgamma gene rearrangement and 2 (4.5%) showed IgH gene rearrangement. Rearrangement of both IgH and TCRgamma genes were detected in 2 cases (4.5%). 14 cases (31.8%) showed p53 positive expression, among which 12 showed positive rearrangement and 2 showed negative (P < 0.01). Eight out of 11 patients of positive gene rearrangement died in one year, while only 3 patients were still alive at the eighteenth month of follow-up, three of 24 patients of negative gene rearrangement were found dead at the time of the one year follow-up, while the rest 21 patients were alive and the longest survival time was 96 months. CONCLUSIONS: Gene rearrangement can define the pathological nature of AIL. The expression of p53 is highly related to gene rearrangement, and thus an important immunological marker in research on AIL.

Follow-Up Studies↗
PubMed2001

[Pathomorphologic features of clinical stage A prostate carcinoma and causes for misdiagnosis and missed diagnosis].

OBJECTIVE: To study the pathomorphologic features and causes for misdiagnosis and missed diagnosis of clinical stage A prostate carcinoma. METHODS: Prostate samples from a series of 1 020 prostate resections performed in five Shanghai hospitals were obtained, from which 50 clinical stage A carcinoma were studied by immunohistochemistry, according to tumor differentiation and their volume, they were divided into stage A1 and A2 disease. The pathomorphologic features of stage A1 and A2 disease were compared, and the causes for misdiagnosis were analysed. RESULTS: Stage A1 cancer were well- or moderately well-differentiated, of low volume and tended to be multifocal; Stage A2 cancers were poorly differentiated, of high volume, diffuse infiltration and with high grade prostatic intraepithelial neoplasia. 8 cases were misdiagnosed of which 7 cases were stage A1 and misdiagnosed as benign proliferous small gland lesions and 1 case of A2 disease was misdiagnosed as epithelioid histiocytic reactive proliferation. CONCLUSIONS: Stage A1 cancer tended to be initiated in the transition zone and the central zone of the hyperplastic prostate. Stage A2 cancers were mostly middle grade to high grade cancers initiated in the peripheral region and then invaded the central area. The lower incidence of stage A carcinoma in China is related to the small amount of biopsy tissue, careless microscopic observation, or lack of the ability to diagnose stage A1 cancer.

Aged↗
PubMed2001

[Studies of intercellular communication in human rhabdomyosarcoma cell lines of different metastatic potential].

OBJECTIVE: To investigate the relationship between intercellular communication and three human rhabdomyosarcoma (RMS) cell lines of different metastatic potential. METHODS: Indirect immunofluorescent staining and laser scanning confocal microscope (ISCM) were used to detect connexin 43 (CX43), a molecule related with gap junctional intercellular communication (GJIC). Fluorescence redistribution after photobleaching (FRAP) was used to detect function of GJIC. RESULTS: A high level of CX43 protein expression was revealed in normal human myoblasts. CX43 protein was mainly localized on the surface of cells and sometimes in cytoplasm. CX43 expression was decreased in RMS cells. Both the detection rates and fluorescent intensity of CX43 decreased when the metastatic potential of RMS increased (P < 0.05). In contrast to normal, the fluorescence recovery rates of the RMS cells decreased and there was a negative correlation between the function of GJIC and malignancy of RMS cell lines (P < 0.05). CONCLUSION: Varying degrees of GJIC inhibition may correlate with different metastatic potential of RMS. This may help to determine the malignant behavior of RMS and be used as a prognostic index of RMS.

Animals↗
PubMed2001

[Sequential intensified immunosuppressive therapy combining with hematopoietic growth factors in the treatment of severe aplastic anemia].

OBJECTIVE: To explore more effective regimen for reducing early mortality of severe aplastic anemia (SAA) and improving therapeutic effectiveness. METHODS: Antilymphocyte globulin/antithymocyte globulin (ALG/ATG) and cyclosporine A (CsA) (sequential intensified immunosuppressive therapy, SIIST), with or without hematopoietic growth factors (HGFs) were administered to 73 SAA patients in a prospective randomized clinical trial to test the effectiveness of the addition of HGFs for the patients. RESULTS: The response rate of SIIST with HGFs group was significantly higher than that of SIIST alone group (89.2% vs 63.9%), with lower rates of early infection (24.3% vs 55.3%) and mortality (4.0% vs 16.7%), shorter duration of cytopenia and blood transfusion dependence and faster recovery of bone marrow hematopoiesis. The addition of HGFs to SIIST was tolerated well in all patients. There was no difference in the treatment outcome of the two groups with GM-CSF plus Epo or G-CSF plus Epo. CONCLUSION: The use of HGFs in combination with SIIST could reduce early infection and mortality rates and, therefore, improve the response rates in SAA patients.

Adolescent↗
PubMed2001

[Effect of inhibition of telomerase activity on cisplatin-induced apoptosis in K562 cells].

OBJECTIVE: To explore the effect of human telomerase reverse transcriptase (hTERT) gene antisense oligodeoxynucleotide (ASODN) on telomerase activity and cisplatin-induced apoptosis in K562 cells. METHODS: Telomerase activity was analyzed by using polymerase chain reaction enzyme-linked immunoassay (PCR-ELISA), expression levels of hTERT protein by immunofluorescence and apoptosis by DNA gel electrophoresis and flow cytometry. RESULTS: There was a marked decrease in both the percentage of hTERT protein positive cells and the telomerase activity in ASODN treated cell as compared with that in control and sense oligodeoxynucleotide (SODN)-treated cells; but no difference between the latter two groups. Agarose gel electrophoresis of genomic DNA from K562 cells treated with ASODN and cisplatin combination for 72 h showed typical DNA ladder; neither did DNA from K562 cells treated with SODN plus cisplatin nor cisplatin alone. Apoptosis rates of K562 cells treated with ASODN for 24 h and then with cisplatin for 72 h were significantly increased. There was statistically significant difference in the percentage of apoptotic cells between hTERT ASODN plus cisplatin group and SODN plus cisplatin or cisplatin alone group. CONCLUSION: The hTERT gene ASODN could inhibit telomerase activity of K562 cells whereby it enhanced cisplatin-induced apoptosis of the cells.

Antineoplastic Agents↗
PubMed2001

[Protective effects of Chinese herb-compound on cellular immunological function (correction of funcion) in tail-suspended rats].

Objective. To observe the protective effects of two kinds of Chinese herb-compounds (Dan-huang-ci compound and Shen-chuan-shu compound) on cellular immunology in tail-suspended rats. Method. The rats were divided into: 1) normal control group; 2) tail-suspended group; 3) tail-suspended + Dan-huang-ci compound; and 4) tail-suspended + Shen-chuan-shu compound. Ability of lymphocyte proliferation and production of IL-2 in rats in the four groups were compared after 21 d. Result. The immunological function of tail-suspended control group decreased significantly as compared with normal control group. Shen-chuan-shu compound could improve immunological function of tail-suspended rats obviously. Conclusion. Shen-chuan-shu compound could enhance cellular immunological function in rats under simulated weightlessness.

Animals↗
PubMed2001

[The development of nanoparticles on DNA isolation and purification].

Magnetic nanoparticle is a new solid-support of affinity chromatography. The particle size is small and it has super-paramagnetism. It has large surface area and it can be endowed many reaction groups such as streptavidin, antibody or DNA fragments. The target DNA can be separated in magnetic field. The magnetic nanoparticle is applied in the biomolecular field gradually and it has a very broad prospect of appliance.

Antibodies↗
PubMed2001

[Cloning of HAL1 gene and characterization for salt tolerance tomato].

The HAL1 gene was cloned by PCR strategy and confirmed by sequencing. Its open read frame is 879 bp, encoding a peptide of 294 amino acids (32 kD Protein). A chimaeric construct of HAL1 and Npt II (neomycin phosphotransferase II) was constructed and introduced into commercial cultivars of tomato (Zhong SU No. 5: Lycopersicon escullentum) by Agrobacterium tumefacien-mediated gene transformation. Transformants were selected for their ability to grow and root on media containing kanamycin. Transformation was confirmed by analysis of PCR, Southern blot and RT-PCR. The salt tolerance of transgenic tomato is evaluated by comparing the fresh weight, dry weight, Na+, K+ content of transgenic tomato and control tomato. It is concluded that the over-expressing of HAL1 in tomato could enhance the salt tolerance of the transgenic tomato.

Cloning, Molecular↗
PubMed2001

[Validation and comparison of ISO standard method for the examination of fluoride in drinking water].

The validation of ISO standard method for the examination of fluoride in drinking water was introduced. The test for compensating interference, standard curves, accuracy, precision and the minimum detection limit etc were included. The comparison between ISO method and others was made. The results indicated that the ISO method was better in anti-interference, wider linear range and higher precision. The points designed were reasonable. The method is superior to other methods in the same kind, and it should be adopted and extended.

Fluorides↗
PubMed2001

[Prospective study of combination of interferon-alpha with ribavirin for treatment of chronic hepatitis C in children].

OBJECTIVE: To explore more efficacious therapy for chronic hepatitis C in children. METHODS: With combination of recombinant interferon-alpha/ribavirin therapy, we treated 15 children, with viral sera and biopsy-proven chronic hepatitis C, who did not respond to the treatment of interferon-alpha alone and had frequently relapse, with the disease courses of 5-9 years (mean 4.5 years). Mean age of the children (12 males and 3 females) was 6.8 years (6 months-10 years). 14 patients had blood transfusion history. RESULTS: HCV RNA in 12 patients was negative after combined treatment of 3 months (1.5-5 months). None of the patients treated had skin rash and severe adverse reaction. Transient fever and influenza-like symptoms with combined therapy were similar to those with interferon-alpha therapy alone. Hemoglobin level decreased slightly in 9 patients (mean decrease by 5 g/L; max, 20 g/L). Reticulocytes elevated slightly. White blood cells, platelets, Bun and Cr were normal in all the patients. CONCLUSION: Our results show that combination of interferon-alpha with ribavirin for treatment of hepatitis C in children is efficacious, safe and reliable. It deserves popularization.

Antiviral Agents↗
PubMed2001

[Molecular cloning and expression in E. coli of the surface-exposed lipoprotein LipL41 gene of Leptospira lai].

OBJECTIVE: To construct a recombinant expressive plasmid using LipL41 gene of leptospira lai for further research of subunit vaccine of leptospira. METHODS: A pair of oligonucleotide primers were designed based on the sequence of LipL41 of leptospira kirschneri RM 52 in Genbank. With genomic DNA of leptospira lai 017 as template, a fragment was amplified by PCR and DNA sequencing analysis showed this fragment to be the gene that encodes LipL41. A recombinant vector was constructed using plasmid pGEX1 lambda T and the expression of LipL41 gene was tested. RESULTS: The production of PCR was LipL41 gene. The recombinant plasmid was constructed and testified by nuclease digestion and PCR, and LipL41 gene could express in E. coli. CONCLUSION: The recombinant plasmid has been constructed successfully and LipL41 gene can express stably at high level.

Bacterial Outer Membrane Proteins↗
PubMed2001

[Expression and significance of TGF-beta 1 in nasal polyps].

OBJECTIVE: To study the expression and significance of transforming growth factor-beta 1(TGF-beta 1) in nasal polyps. METHOD: Expression of TGF-beta 1 in nasal polyps from 34 patients and middle turbinates from 30 patients with deviation of nasal septum were prospectively studied with immunohistochemistry. Each tissue section was observed under optical microscope. RESULT: 1. The TGF-beta 1 positivity in extracellular matrix and in cells in the stroma was significantly higher in nasal polyps than in middle turbinates (P < 0.01). 2. The distribution and shape of TGF-beta 1 expressing cells in nasal polyps was similar to that of eosinophil, their positivities were significantly correlative (P < 0.05). 3. The positivity of TGF-beta 1 did not correlate with clinical type of nasal polyps (P > 0.05), eosinophil infiltration correlated significantly with clinical type of nasal polyps(P < 0.05). CONCLUSION: 1. The TGF-beta 1 may contribute to some of the pathologic changes observed in nasal polyps, such as thickening of the epithelial basement membrane and stromal fibrosis. 2. Eosinophils in nasal polyps represent a major source of TGF-beta 1. 3. Eosinophils infiltration may play a prominent role in the development and recurrence of nasal polyps.

Adolescent↗
PubMed2001

[The clinical value of the TSGF pre and post-therapy in patients with nasopharyngeal carcinoma(NPC)].

OBJECTIVE: To investigate the role of TSGF (tumor supplied group of factor) in early diagnosing and predicting in patients with NPC. METHOD: EBV-IgA and level of TSGF were measured before therapy and 1 month, 1 year after therapy in 35 patients with NPC, and the relationship between them was researched. RESULT: The diagnostic sensitivity of TSGF and EBV-IgA was 91%, 97% respectively, there is no significant relation between them. After treatment, the level of TSGF in PD (progression disease) patient remained higher, but had a significantly drop in RR(including the CR, PR and SI)) patient. CONCLUSION: Results suggested that TSGF may be useful in diagnosing and prediction of NPC.

Adult↗
PubMed2001

[Determination of carfentrazone-ethyl(F8426) residue in soil and wheat by wide-bore capillary gas chromatography].

An efficient method for determining F8426 of Affinity 40 DF in soil and wheat is described. F8426 was extracted from the soil and the wheat sample with acetone-water (80:20, volume ratio), and the extract was partitioned with petroleum ether. Then the upper layer was concentrated and cleaned up on a micro-column of Florisil and activated carbon mixture. Finally F8426 was separated from other interfering components through wide-bore capillary gas chromatographic column (OV-1701, 12 m x 0.53 mm i.d.), and was detected by electron capture detector (ECD). The lowest detection limit for F8426 was 0.02 ng. The lowest detectable concentrations in wheat and soil was 2 micrograms/kg and 1 microgram/kg respectively. The average recovery and coefficient of variation of this method were 89.60%-97.53% and 4.42%-8.67% respectively. This method is simple, sensitive and suitable for residue analysis of F8426.

Chromatography, Gas↗