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Biomedical subjects

F He

Publications and source records attributed to F He.

At least 73 records · Page 4Linked to original sources
PubMed2000

Neurotoxic effects of insecticides--current and future research: a review.

The clinical manifestations and mechanism of acute effects of organophosphate, carbamate and pyrethroid insecticides on the central and peripheral nervous systems are reviewed. The controversies of persistent effects following acute pesticide poisoning and the effects of long-term low level pesticide exposure are discussed. Based on the current issues of insecticide neurotoxicity, future research needs are recommended.

Agricultural Workers' Diseases↗
PubMed2000

Anticancer treatment of endostatin gene therapy by targeting tumor neovasculature in C57/BL mice.

Antiangiogenesis strategy has been widely recognized as a viable approach to fight cancer. Considering the high cost and inconvenience of protein therapy of endostatin (ES), which is a potent antiangiogenic protein, we attempted to explore the inhibitory effect of ES gene therapy on tumor growth and metastasis. In this experiment, Lewis lung carcinoma (LLC)-bearing C57/BL mice were used to evaluate the antitumor effect of ES gene therapy and its impairment of tumor neovasculature. The data showed that the ectopic ES in circulation expressed by intramuscular administration of formulated ES-encoding plasmid DNA significantly suppressed primary tumor growth and lung metastasis in LLC-bearing C57/BL mice. Hence, our results demonstrated the inhibitory effect of ES gene therapy on angiogenesis-dependent tumor growth and metastasis.

Angiogenesis Inhibitors↗
PubMed2000

[Production of phage-displayed single chain variable fragments of monoclonal antibody MGb1].

OBJECTIVE: To lay a foundation for obtaining a tumor-targeting vehicle for in vivo study on diagnosis and treatment of gastric carcinoma by generating single chain variable fragments (ScFv) of monoclonal antibody MGb1 directed against the cancer. METHODS: mRNA was isolated from MGb1-producing mouse hybridoma cell line, and the variable regions of heavy and light chain cDNAs were amplified separately and assembled into ScFv DNAs with a specially constructed linker DNA by PCR. The ScFv DNAs were ligated into the phagemid vector pCANTAB5E and the ligated sample was transformed into competent E. coli TG1. The transformed cells were infected with M13KO7 helper phage to yield recombinant phage, which display ScFv fragments as a fusion with gene 3 protein on the tips of the phage M13. After two rounds of panning with gastric carcinoma cell line KATO III highly expressing MGb1-binding antigen, the phage clones displayed ScFv fragments of the antibody were selected by enzyme-linked immunosorbent assay (ELISA) from the enriched phages. The affinity of the positive phage clones was detected by competition ELISA. RESULTS: The VH, VL and ScFv DNAs were about 340 bp, 320 bp and 750 bp respectively. 17 phage clones displayed ScFv of MGb1 were selected from 40 enriched phage clones. 4 out of the 17 phage clones could strongly compete with the original hybridoma antibody MGb1 for binding to the antigen expressed on KATOIII cells. CONCLUSION: The phage-displayed ScFv fragments of monoclonal antibody MGb1 are successfully produced by phage antibody technology, which may be useful to widen the range of application of the antibody.

Animals↗
PubMed2000

[Cloning of mouse endostatin and primary analysis on its biological activity].

The mouse endostatin cDNA was cloned by the total RNA of Chinese Kunming mouse liver as template with RT-PCR. The results of sequencing showed one base pair difference. The ctg was replaced by gtg(L22545 in GenBank) at position 278 base pair, causing the encoded amino acid from reported Val to Leu in this experiment. This new endostatin cDNA was registered in GenBank with an accession number of AF257775. The recombinant eukaryotic expression plasmid pSecTag2-ES was then constructed and transfected into COS-7 cells for transient expression. The results of testing by Western blotting showed an expression fragment in supernatants of pSecTag2-ES transfected COS-7 cells at 48 and 72 hours of transfection. Cultured HUVECs were used to detect the biological effect of supernatants in pSecTag2-ES transfected COS-7 after 48 hours of transfection. 3H incorporation assay showed an obvious inhibition of endothelial cell prolifetation. The results demonstrated primary that the cloned endostatin cDNA had biological activity.

Angiogenesis Inhibitors↗
PubMed2000

[Clinical analysis of 20 cases of adenoidal hypertrophy in adult].

OBJECTIVE: To discuss the diagnosis and properly treatment to the adult adenoidal hypertrophy. METHOD: To do nasal endoscopic and pathologic exam to all the 20 symptomatic patients before conservative or operative treatment. RESULT: The results of exam under endoscope were that 8 patients were hypertrophy I, 8 hypertrophy II, 4 hypertrophy III. Pathologic exam: 7 acute and chronic inflammation, 13 chronic inflammation with hyperplasia. TREATMENT: 10 of them received conservative treatment all have negative result. 6 received traditional operation, 2 of them reoccurred within 1 year. 4 received adenoidectomy and microwave treatment under nasal endoscope, all have good result in the next 1 year. CONCLUSION: Some adults have different sizes of adenoidal hypertrophy. This hypertrophy is different with children's under the pathologic microscope. Operative treatment especially the nasal endoscopic adenoidectomy and microwave treatment is a safe and effective method.

Adenoidectomy↗
PubMed2000

[Studies on Euphorbia fischeriana diterpenoide lactones inhibitory effect on human tumor cells in vitro].

In this paper, two diterpenoide lactones 16-hydroxypseudojolkinolide B and jolkinolide B were isolated from Euphorbia fischeriana Steud. They showed inhibitory effect on human tumor cells both the K562 cell and CNE2 cell and significant dose-effect relationship. The IC50 values of 16-hydroxypseudojolkinolide B on the two human tumor cells were near to that of ADM's.

Antineoplastic Agents, Phytogenic↗
PubMed2000

[Characteristic immunodeficiency syndrome of rapid fatal type of simian immunodeficiency virus infected monkeys].

OBJECTIVE: To observe the characteristic immunodeficiency syndrome of the rapid fatal type of simian immunodeficiency virus (SIV) infected monkeys. METHODS: Eighty rhesus monkeys and 4 cynomolgus monkeys were intravenously inoculated with SIVmac or SIVmac251. The virus isolation and viral titer, estimation by indirect immunofluroresence and viral antibody were determined periodically from monkeys' plasma; lymph node biopsies were performed for pathohistological examination. RESULTS: Twelve out of 84 macaque (14.2%) died of rapid progressive type after inoculation of SIVmac and SIVmac251 in the duration 3 to 4 months. Dying monkeys showed persistent high viremia and low level titre antibody. Eight of 10 pathohistological changes showed severe depletion of lymphoid tissue in spleen and lymph nodes, there were remarkable immunodeficiency with opportunity infection. The other two monkeys appeared moderate lymphoid tissue deletion and hyperplasia without opportunity infections. The survived monkeys' (72/84) lymph nodes biopsies revealed hypoplasia of lymphoid tissue. CONCLUSIONS: The characteristic immunodeficiency syndrome of rapid fatal type of simian immunodeficiency virus infected monkeys could be made with persistent high viremia, low level antibody, severe lymphoid tissue deletion in lymph nodes and spleen, as well as complicated opportunity infections.

Acute Disease↗
PubMed1999

Biological monitoring of exposure to pesticides: current issues.

Biological monitoring is becoming an increasingly important element of field studies designed to assess the risk from occupational pesticide exposure for preventive purposes. Selection of suitable biomarkers of exposure to pesticides, development of detection methods, validation of measurement and interpretation of results are of utmost concern among current issues. This paper provides an overview on the research strategies and application of biological monitoring of pesticide exposure.

Acetylcholinesterase↗
PubMed1999

Identification and characterization of receptor for mammalian hepatopoietin that is homologous to yeast ERV1.

Hepatopoietin (HPO) is a novel polypeptide mitogen specific for hepatocytes and hepatoma cell lines, which is derived from liver and supports its regeneration. To determine whether HPO acts via a receptor-based signal transduction, recombinant human hepatopoietin was labeled by iodination and used to characterize its binding activity by specific displacement test and Scatchard analysis in primarily cultured rat hepatocytes and human hepatoma Hep-G2 cells. The binding was saturable and specific because it was replaceable by HPO but not by epidermal growth factor, transforming growth factor-alpha, or insulin. Scatchard analysis indicated the presence of a single class of high affinity receptor with dissociation constant (Kd) of 2 and 0.7 pM, and a receptor density of about 10, 000 sites/cell and 55,000 sites/cell in the rat hepatocytes and human hepatoma cells, respectively. The Kd values were consistent with the half-maximum dose of HPO activity. Affinity cross-linking of the receptor with 125I-HPO revealed a polypeptide of molecular mass approximately 90 kDa by SDS-polyacrylamide gel electrophoresis. Thus, the molecular mass of the HPO receptor was calculated to be about 75 kDa. These data demonstrated the existence of an HPO receptor in hepatocytes and hepatoma cells, which may account for biological effect.

Animals↗
PubMed1999

[Effect of dimethoate on the expression of c-fos gene in skeletal muscle].

To elucidate the effect of organophosphate pesticides on the expression of immediate early gene in skeletal muscle, the concentrations of c-fos mRNA and protein were measured by RT-PCR and western dot blot techniques. The result showed that c-fos mRNA and protein were significantly increased in skeletal muscle of rat after dosing with dimethoate. These results indicated that c-fos might act as transcription factor and regulate other gene expression during the early period of organophosphate intoxication.

Animals↗
PubMed1999

CeReS-18 inhibits growth and induces apoptosis in human prostatic cancer cells.

BACKGROUND: Polypeptide growth factors are positive and negative regulators of prostatic growth and function, and many positive regulators of growth in the prostate have been extensively studied. However, very few inhibitors of prostate cell proliferation have been identified. We have isolated a unique 18-kDa sialoglycopeptide (CeReS-18) which inhibits cell proliferation of three separate lines of human prostate cancer cells, as well as inducing cellular cytotoxicity via an apoptotic pathway unrelated to the Bcl-2 family of proteins. METHODS: Cell cycle inhibition was analyzed by direct cell counts with a Coulter (Miami, FL) cell counter. Apoptotic cells were analyzed by electron microscopy, annexin V-fluorescein isothiocyanate (FITC) staining, fluorescence microscopy, and propidium iodide uptake measured with a fluorescence-activated cell sorter. Expression of the proteins of the Bcl-2 family was detected by Western blot analysis. RESULTS: We found that CeReS-18 inhibits cell proliferation of androgen-responsive, LNCaP.FGC human prostate cancer cells, as well as of androgen-nonresponsive DU-145 and PC3 human prostate cancer cells. Furthermore a, fivefold increase over the inhibitory concentration of CeReS-18 elicited a cytotoxic response by all three cell lines. We thus characterized the cytotoxic mechanism as apoptotic in nature, and we measured the expression of several members of the Bcl-2 family in PC3 cells upon treatment with CeReS-18. CONCLUSIONS: The data indicate that CeReS-18 is a potent inhibitor of cellular progression through the cell cycle by both androgen-responsive and androgen-nonresponsive human prostate cancer cells. In addition, treatment of both types of cells with increased concentrations of CeReS-18 induces cellular cytotoxicity, characterized as apoptosis.

Annexin A5↗
PubMed1999

Effect of IL-1 beta and TNF-alpha on the expression of monocyte chemotactic protein-1 in endometriotic cells.

To investigate the clinical significance of monocyte chemotactic protein-1 (MCP-1) produced by endometriotic tissues, the endometriotic tissues were taken from 15 patients with endometriosis. MCP-1 mRNA and MCP-1 protein were determined by dot blot analysis and enzyme linked immunosorbent assay (ELISA) in endometriotic cells cultured with or without interleukin-1 beta (IL-1 beta, 2 micrograms/L), tumor necrosis factor-alpha (TNF-alpha, 20 g/L). After exposure to IL-1 beta or TNF-alpha, the expression of MCP-1 mRNA in the endometriotic cells (8.635 +/- 0.826, 7.031 +/- 0.970, respectively) were significantly higher than that in the control group (4.482 +/- 0.435, P < 0.05); The expression of MCP-1 protein in IL-1 beta and TNF-alpha group was 4.52 +/- 0.09 micrograms/L, 2.87 +/- 0.27 micrograms/L, respectively, which were significantly higher than 1.74 +/- 0.16 micrograms/L in control (P < 0.01). The results suggested that IL-1 beta and TNF-alpha could up-regulate the expression of MCP-1 in endometriotic cells, which might be related to the development of endometriosis.

Cells, Cultured↗
PubMed1999

Overexpression of truncated Nmd3p inhibits protein synthesis in yeast.

The yeast NMD3 gene was identified in a two-hybrid screen using the nonsense-mediated mRNA decay factor, Upf1p, as bait. NMD3 was shown to encode an essential, highly conserved protein that associated principally with free 60S ribosomal subunits. Overexpression of a truncated form of Nmd3p, lacking 100 C-terminal amino acids and most of its Upf1p-interacting domain, had dominant-negative effects on both cell growth and protein synthesis and promoted the formation of polyribosome half-mers. These effects were eliminated by truncation of an additional 100 amino acids from Nmd3p. Overexpression of the nmd3delta100 allele also led to increased synthesis and destabilization of some ribosomal protein mRNAs, and increased synthesis and altered processing of 35S pre-rRNA. Our data suggest that Nmd3p has a role in the formation, function, or maintenance of the 60S ribosomal subunit and may provide a link for Upf1p to 80S monosomes.

Amino Acid Sequence↗
PubMed1999

The inhomogeneous conductivity property of cranial tissues and its representation in numerical head models.

The inhomogeneous conductivity of cranial tissues is discussed in this paper. A novel approach for including detailed tissue inhomogeneity is proposed and developed using pseudo-conductivity values which are derived from the limited data available from physiological experiments. Simulation studies of the effects caused by the inclusion of inhomogeneity in the EEG forward problem are also presented in this paper. The results suggest that the accurate representation of the tissue inhomogeneity improves the quality of the computed EEG forward solution. Conclusions about the effects of inhomogeneity on the potential distribution are given.

Brain↗
PubMed1999

[The profile of low bone mass in amenorrhea with elevated follicle stimulating hormone].

OBJECTIVE: To observe the characteristics of low bone mass in amenorrhea with elevated follicle stimulating hormone(FSH). METHODS: Amenorrhea patients with elevated FSH: primary amenorrhea (PA) 18 cases, secondary amenorrhea (SA), 171 cases and age matched control with normal menstruation (Nor) 180 cases. The descriptive parameters were: estradiol (E2), alkaline phosphatase (ALP), urinary excretion of calcium to creatinine ratio (Ca/Cr), the cortical bone mineral density (CBMD) at right radius measured by single photon absorptimetry (SPA) and the trabecular bone mineral density (TBMD) at lumbar vertebra body measured by quantitative computerized tomography (QCT). RESULTS: The experiment had shown the average E2 level in amenorrhea patients to be < 150 pmol/L. Significantly higher ALP and Ca/Cr values than the Nor group. In the SA group, the CBMD value was (655 +/- 69) mg/cm2, which was significantly lower than the Nor group's value of (677 +/- 56) mg/cm2 (3.2% lower, P < 0.01). The TBMD value is (145 +/- 26) mg/cm3, which is significantly lower than the Nor group's value of (192 +/- 28) mg/cm3 (24.5%, P < 0.001). The disparity with the Nor group was even greater in the PA group (11.1% and 35.7% lower, respectively). The BMD of the amenorrhea patients were negatively linearly correlated with their amenorrhea age. CONCLUSIONS: The serum estradiol level in amenorrhea patients with high FSH was so low that their bone turnover was increased which led to the insufficient bone accumulation and dramatically dropping of TBMD. Its extent was related to the initial age and the duration of ovarian failure.

Absorptiometry, Photon↗
PubMed1999

[Investigation of the apoptosis and proliferation in endometriotic cells].

OBJECTIVE: To clarify whether apoptosis is involved in endometriosis and the effects of estradiol, progesterone and mifepristone on the expression of epidermal growth factor receptor(EGFR) in cultured human endometriotic cells. METHODS: Apoptosis index and bcl-2 gene expression were examined in cultured ectopic endometrial cells from women with endometriosis (n = 15 samples) and compared with eutopic endometrial cells from non-endometriosis cases(n = 11 samples). Apoptotic cells were detected by flowcytometry; bcl-2 gene expression demonstrated by in situ hybridization technique. The cultured endometriotic cells were stimulated by estradiol(E2, 10 nmol/L), progesterone(P, 100 nmol/L), and P + mifepristone(P 100 nmol/L + mifepristone 1,000 nmol/L) respectively for 5 days, the expression of EGFR mRNA of endometriotic cells were determined by reverse transcript polymerase chain reaction (RT-PCR) method. RESULTS: The apoptosis index was significantly decreased in the ectopic endometrial cells [(2.74 +/- 1.54)%] as compared to eutopic endometrial cells [(9.97 +/- 1.26)%] (P < 0.05). bcl-2 expression in endometriotic cells was significantly increased compared with the eutopic endometrial cells (P < 0.05). The expression of EGFR mRNA in E2, P group was 1.10 +/- 0.19 and 1.28 +/- 0.24 respectively, which were significantly higher than that of control(0.90 +/- 0.10, P < 0.01). In P + mifepristone group it was 0.63 +/- 0.11, significantly lower than that of control(P < 0.001). CONCLUSION: The resistance of endometriotic cells to apoptosis may be fundamental in the aetiology and (or) pathophysiology of endometriosis. Estradiol and progesterone promote hyperplasia and differentiation of endometriotic cells while mifepristone inhibits.

Adult↗
PubMed1999

[Determination of monocyte chemotactic protein-1 in cultured endometriotic cells].

OBJECTIVE: To investigate the clinical significance of monocyte chemotactic protein-1 (MCP-1) produced by endometriotic tissues. METHODS: Expressions of MCP-1 mRNA and MCP-1 protein were determined by dot blot analysis, immunohistochemical method [streptavidin biotin-peroxidase complex (SABC)] and enzyme linked immunosorbent assay (ELISA) methods in cultured endometriotic cells with median (controls) or with interleukin-1 beta(IL-1 beta) 2 ng/ml (IL-1 beta group), and tumor necrosis factor-alpha(TNF-alpha) 20 mg/ml(TNF-alpha group) respectively. The endometriotic tissues were sourced from 15 patients with endometriosis. Meanwhile, the MCP-1 protein content of cultured supernatent was also measured. RESULTS: After exposured to IL-1 beta or TNF-alpha, the expression of MCP-1 mRNA and MEP-1 protein in the endometriotic cells were significantly higher than that in the control group (P < 0.01, P < 0.05 respectively); so was the MCP-1 protein content of supernatent. CONCLUSIONS: IL-1 beta and TNF-alpha can up-regulate the expression of MCP-1 in endometriotic cells, which may be related to the development of endometriosis.

Adult↗