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Biomedical subjects

Z Li

Publications and source records attributed to Z Li.

At least 595 records · Page 33Linked to original sources
PubMed2000

[Relationship between folate, vitamin B12, total plasma homocysteine and mutation of reductase].

OBJECTIVE: To study relationship between serum and red blood cell (RBC) folate, serum vitamin B(12) (VB(12)), total plasma homocysteine (tHcy), thermolabile genotypes, and activity of methylene-tetrahydrofolate reductase (MTHFR). METHODS: Thirty-four non-pregnant and healthy mothers who gave birth to babies with neural tube defects (NTDs) and 42 mothers to normal babies previously were chosen. Plasma tHcy, RBC and serum folate, serum VB(12), activity of MTHFR and thermolabile genotypes were determined for all of them. RESULTS: There was no significant difference in plasma tHcy, RBC and serun folate between case and control groups. Serum VB(12) was significantly lower in mothers of babies with NTDs than in those with normal ones. Plasma tHcy correlated with RBC folate inversely (P < 0.05). Mean plasma tHcy for thermolabile homozygous mutation of MTHFR was significantly higher than that for either heterozygous mutation or wild homozygous mutation (P < 0.001). There was no significant difference in serum folate between groups with varied MTHFR genotypes. Plasma tHcy was slightly greater in those with lower serum folate than in those with higher one, and correlated inversely with activity of MTHFR. CONCLUSIONS: Increase in plasma tHcy correlates with homozygous mutation of thermolabile MTHFR and decrease in activity of MTHFR. Higher level of folate in the body can interfere the relationship between plasma tHcy and activity of MTHFR.

Adult↗
PubMed2000

[The effects of escharectomy en masse during shock stage on the secretion of cytokines from macrophage in scalded rats].

OBJECTIVE: To explore the effects of the plasma from rats undergoing escharectomy en masse during shock stage on the secretion of TNFalpha, IL-6 and IL-8 by macrophage. METHODS: Rats inflicted by 30% III degree scald were employed as the model. Sixty-three rats were randomly divided into escharectomy (E) and scald (C) groups. The plasma contents of TNFalpha, IL-6 and IL-8 in rats in two groups were determined. The plasma from rats in two groups was respectively co-cultured with rat peritoneal macrophages for 6 hours and the TNFalpha, IL-6 and IL-8 in the supernatants of the culture were assayed. RESULTS: Plasma contents of TNFalpha, IL-6 and IL-8 were evidently increased in both E and C groups. But the contents of these cytokines in E group decrease and were much lower than those in C group at 12 postburn hour. The sera from two groups of rats could all stimulate the secretion of TNFalpha, IL-6 and IL -- 8 from peritoneal macrophages, but the serum from C group possessed stronger stimulating ability than that from E group. CONCLUSION: Escharectomy en masse during shock stage could weaken the ability of burn sera to induce the secretion of TNFalpha, IL-6 and IL-8 by macrophages. It was therefore beneficial to the prevention of postburn development of systemic inflammatory response syndrome.

Animals↗
PubMed2000

[The significance of the adhesion of CD(34)(+) stem/progenitor cells to fibronectin in the pathogenesis of chronic myelogenous leukemia].

OBJECTIVE: To investigate the significance of the adhesion of CD(34)(+) stem/progenitor cells to fibronectin in the pathogenesis of chronic myelogenous leukemia (CML). METHODS: (1) Integrin beta(1) chain (CD(29)) and alpha(4) chain (CD(49d)) expressions on CD(34)(+) cells were measured by flow cytometry in 30 untreated CML patients in chronic phase (CML-CP) and 10 healthy donors. (2) The adhesion function of immunomagnetic beads selected CD(34)(+) cells to fibronectin was detected by crystal violet staining in 5 untreated CML-CP patients and 5 healthy donors. (3) The effect of fibronectin on CFU-GM colony formation of bone marrow cells in 3 CML patients and 3 healthy donors was observed by limited dilution liquid microculture. RESULTS: (1) There was no significant difference in CD(29) and CD(49d) expressions on CD(34)(+) bone marrow cells between CML patients and healthy donors. (2) The adhesion of CD(34)(+) bone marrow cells to fibronectin decreased significantly in CML patients as compared with that in healthy donors (P < 0.01). (3) The CFU-GM colony formation was significantly inhibited by fibronectin in healthy donors (P < 0.01), but not in CML patients. CONCLUSION: The adhesion function abnormality of CML CD(34)(+) bone marrow cells to fibronectin may underlie the abnormal proliferation of CML progenitors.

Antigens, CD34↗
PubMed2000

[Effects of holothuria glycosaminoglycan on the expression of tissue factor and thrombomodulin in stimulated endothelial cells].

OBJECTIVE: To study the mechanism of antithrombotic effects of holothuria glycosaminoglycan (GAG). METHODS: Endothelial cells from human umbilical vein which were pre-induced with 1 mg/L lipopolysaccharide, were treated by GAG (1 mg/L, 5 mg/L, and 10 mg/L, respectively) and 5 mg/L heparin as a control for 6 hours. Procoagulant activity (PCA), the expressions of tissue factor (TF) antigen and thrombomodulin (TM) antigen and their mRNA transcriptions were investigated. RESULTS: GAG could down-regulate the expression of TF antigen and mRNA, up-regulate the expression of TM antigen and mRNA, down-regulate the PCA of stimulated endothelial cells. CONCLUSION: Down-regulating TF expression and up-regulating TM expression of stimulated endothelial cells may be one of the mechanisms of GAG antithrombosis.

Animals↗
PubMed2000

[Retroviral-mediated high efficient in vitro expression of human coagulation factor VIII].

OBJECTIVE: To develop a retroviral-mediated high efficient expression system of human coagulation factor VIII. METHODS: The retroviral vector LNC-VIIIBD was generated by cloning a B-domain-deleted FVIII cDNA (760aa - 1639aa) into retroviral vector pLNCX. Several cell lines including NIH3T3, CHO, COS-7 and human hepatic cell line L-02 were infected with viral supernatant from the highest productive PA317 clones. The antigen and procoagulant activity of human FVIII in the cell culture medium were measured by ELISA assay and one-stage method, respectively. RT-PCR was performed for the detection of F VIII BD mRNA. RESULTS: Human FVIII was expressed in all four target cells. The highest expression was observed in NIH3T3, the procoagulant activity of secreted FVIII was up to 1.6 U, and the FVIII antigen was 500 ng by 10(6) cells/ml in 24 hours, respectively. CONCLUSION: The constructed retroviral vector was able to generate high level expression of human FVIII in some cell lines, and it might have potential utility in the gene therapy for Hemophilia A.

3T3 Cells↗
PubMed2000

[Influence of pravastatin on expression of platelet CD(62P) and CD(41) in patients with hypercholesterolemia in vitro and in vivo].

OBJECTIVE: To study in vitro and in vivo effect of hypercholesterolemia (HC) on expression of platelet CD(62P) and CD(41) and their changes after treatment with pravastatin. METHODS: Twenty patients with HC were given 10 - 20 mg/d pravastatin orally for 4 - 8 weeks. Changes of blood cholesterol and expression of platelet CD(62P) and CD(41) were detected by flow cytometry. RESULTS: After 4 and 8 weeks' treatment, blood cholesterol level and platelet aggregation function decreased. The expression of CD(62P) average fluorescence intensity decreased from 31.8 +/- 7.8 to 27.2 +/- 6.9 and 26.8 +/- 4.9; CD(62P) (%) from (31.3 +/- 9.3)% to (26.4 +/- 7.4)% and (25.3 +/- 9.1)% (P < 0.05); CD(41) from 483.2 +/- 263.9 to 348.1 +/- 192.4 and 306.8 +/- 128.0 (P < 0.05), respectively. Similar results were obtained in vitro study. CONCLUSION: Improvement of platelet function and expressions of CD(62P) and CD(41) in HC patients after prevastatin treatment may be resulted from enhancing arteriosclerosis regression. It suggested from the in vitro result that pravastatin might play a direct effect on platelet function.

Adult↗
PubMed2000

[Long-term expression of MHC-I gene in recipient mice].

OBJECTIVE: To explore the possibility of long-term expression of transferred MHC-I gene in recipient mice. METHODS: MHC-I gene of the donor mouse (C(57)BL/6) was transferred into the recipient (BALB/c) hematopoietic cells by retrovirus-mediated gene transfer technique, and the gene transferred cells were reinfused into the recipient mice. PCR, RT-PCR and FACS were used to assay the long-term expression of MHC-I gene in the recipient mice. RESULTS: The gene transferred mice hematopoietic cells and their G418-resistant CFU-GM were demonstrated to be able to express the MHC-I gene. The cells proliferation and differentiation had no change. The MHC-I gene could be expressed for a longer period in the recipient mice. CONCLUSION: This experiment makes ready for the further research on inducing transplantation tolerance through MHC-I gene transfer.

Animals↗
PubMed2000

[Clinical study on treatment of infantile rotaviral enteritis with Psidium guajava L].

OBJECTIVE: To observe the clinical effect of olium Psidium guajava (PG) in treating infantile rotaviral enteritis. METHODS: Sixty-two patients of rotaviral enteritis were randomly divided into the treated group treated with PG and the control group treated with Gegen Qinlian decoction. The time for ceasing diarrhea, the content of Na+ in blood, the content of Na+ and glucose in stool, and the rate of negative conversion of human rotavirus (HRV) antigen were observed. RESULTS: The rate of recovery in 3 days of the treated group was 87.1%, significantly higher than that of the control group (58.1%, P < 0.05). The time of ceasing diarrhea of the treated group (25.1 +/- 9.5 hr) was significantly shorter than that of the control group (38.7 +/- 15.2 hr, P < 0.01). The content of Na+ and glucose in stool was reduced obviously in the treated group, while the reduction in the control group was insignificant, the treated group was superior to the control group significantly (P < 0.05). The rate of negative conversion of HRV in feces of the treated group was 87.1%, significantly better than that of the control (58.1%, P < 0.05). CONCLUSION: The treatment with PG has good curative effect on infantile rotaviral enteritis.

Adolescent↗
PubMed2000

[MTHFR gene expression in EB virus transformed human B lymphoblasts].

In order to detect the expression of N5, N10-methylene-tetra hydrofolate reductase(MTHFR) gene in Epstein-Barr virus(EBV) transformed human B lymphoblast, as well as the cDNA sequence, human peripheral blood was transformed by EBV to build B lymphoblast cell line. Total RNA was isolated from the cell culture. Variant segments of MTHFR cDNA were amplified using RT-PCR protocol and analysed by polyacrylamide gel electrophoresis(PAGE). One of the cDNA segments was sequenced. Results showed MTHFR gene was expressed in human B lymphoblast cell line. The cDNA sequence was almost the same as that of human liver cDNA from Genbank.

B-Lymphocytes↗
PubMed2000

[Measurement of content of collagen type IV and laminin in tissue of oral squamous cell carcinoma and its clinical significance].

OBJECTIVE: To investigate the relationship between the content of collagen type IV (ColIV) and laminin (LN) in tissue of oral squamous cell carcinoma and the clinicopathological parameters. METHODS: 30 patients with oral squamous cell carcinoma came into the study, 6 normal mucosa tissue came from patients who underwent orthogathic operations. The extraction solution was prepared by homogenizing of cancer and normal mucosa tissue in extraction buffer. The content of ColIV and LN in tissue of oral squamous cell carcinoma were measured by radioimmunoassay and represented by amount of per milliliter extraction solution. Mode of invasion (MI) was divided into 4 types basing on the relationship between normal and cancer tissue. The results of measurement of content of ColIV and LN were expressed using mean +/- s, whose correlation with clinicopathological parameters was evaluated by using Student t test. RESULTS: The MI classification showed that type I consisted of 4 cases, and type II comprised 12 cases. 5 and 9 cases belonged to type III and type IV respectively. The content of LN and ColIV in tumor tissue were 1.02 +/- 0.11 micrograms/ml and 1.83 +/- 0.21 micrograms/ml respectively, and the content of LN and ColIV in normal tissue were 1.98 +/- 0.23 micrograms/ml and 2.87 +/- 0.45 micrograms/ml respectively. There was significant difference between the content of ColIV and LN in normal and tumor tissue, and the content of ColIV and LN in normal tissue was much higher than that in cancer tissue (P < 0.05, P < 0.01). No relationship was found between the variation of ColIV and LN content and location and pathological grade of squamous cell carcinoma (P > 0.05), but it was found the content of LN and ColIV in patients with neck lymph node metastasis were greater than that in patients without metastasis (P < 0.05). Content of LN and ColIV also showed negative relationship with the MI index. CONCLUSION: The assay of LN and ColIV in tumor might be useful for diagnosis of metastasis of oral squamous cell carcinoma, and moreover, the relationship between ColIV and LN and MI also gives the suggestion that ColIV and LN may play some roles in preventing the invasion of oral squamous cell carcinoma.

Adult↗
PubMed2000

[A surface reacted layer study of titanium-zirconium alloy after dental casting].

OBJECTIVE: To investigate the influence of the mold temperature on the surface reacted layer of Ti-Zr alloy castings. METHODS: Ti-Zr alloy was casted into a mold which was made of a zircon (ZrO2.SiO2) for inner coating and a phosphate-bonded material for outer investing with a casting machine (China) designed as vacuum, pressure and centrifuge. At three mold temperatures (room temperature, 300 degrees C, 600 degrees C) the Ti-Zr alloy was casted separately. The surface roughness of the castings was calculated by instrument of smooth finish (China). From the surface to the inner part the Knoop hardness and thickness in reacted layer of Ti-Zr alloy casting was measured. The structure of the surface reacted layer was analysed by SEM. Elemental analyses of the interfacial zone of the casting was made by element line scanning observation. RESULTS: The surface roughness of the castings was increased significantly with the mold temperature increasing. At a higher mold temperature the Knoop hardness of the reactive layer was increased. At the three mold temperature the outmost surface was very hard, and microhardness data decreased rapidly where they reached constant values. The thickness was about 85 microns for castings at room temperature and 300 degrees C, 105 microns for castings at 600 degrees C. From the SEM micrograph of the Ti-Zr alloy casting, the surface reacted layer could be divided into three different layers. The first layer was called non-structure layer, which thickness was about 10 microns for room temperature group, 20 microns for 300 degrees C and 25 microns for 600 degrees C. The second layer was characterized by coarse-grained acicular crystal, which thickness was about 50 microns for three mold temperatures. The third layer was Ti-Zr alloy. The element line scanning showed non-structure layer with higher level of element of O, Al, Si and Zr, The higher the mold temperature during casting, the deeper the Si permeating and in the second layer the element Si could also be found. CONCLUSION: The mold temperature is one of the major factors influencing to casting quality. In order to reduce the surface reacted layer of Ti-Zr alloy castings, the lower mold temperature and the investment without Si should be chosen.

Dental Alloys↗
PubMed2000

[A clinical study on PA-MSHA vaccine used for adjuvant therapy of lymphoma and lung cancer].

The objective of this study was to evaluate the effectiveness and safety of pseudomonas aeruginosa MSHA vaccine (PA-MSHA vaccine) used as an immune modulator. The study was carried out after the design of a non-blind, randomized controlled trial. The malignant lymphoma patients were divided into experiment group (45 cases) and control group (43 cases). Likewise were distributed the lung cancer patients: 44 cases in experiment group and 45 cases in control group. The two experiment groups received chemotherapy + PA-MSHA vaccine. The two control groups were given chemotherapy alone. The results showed that the clinical efficacy rate was 95.56% for the exp. group and 69.77% (P < 0.01) for the control group of the malignant lymphoma cases; the clinical efficacy rate was 59.09% for the exp. group and 42.22% (P < 0.01) for the control group of the lung cancer cases. The infection rate was 17.78% for the exp. group and 37.21% (P < 0.05) for the control group of the malignant lymphoma cases; the infection rate was 15.91% for the exp. group and 40.00% (P < 0.05) for the control group of the lung cancer cases. The comprehensive immune effectiveness rates for the exp. group and control group of the malignant lymphoma cases were 77.78% and 23.26% (P < 0.01) respectively. The comprehensive immune effectiveness rates for the exp. group and control group of the lung cancer cases were 84.09% and 35.56% (P < 0.01) respectively. Adverse reactions were found in 5 cases, of which, one was given medical care while the others automatically recovered. These results indicate that PA-MSHA vaccine, as a new kind of immune modulator, can improve the effectiveness of treatment for tumor with low adverse reaction rate.

Adjuvants, Immunologic↗
PubMed2000

[Genetical analysis on cross incubation of Beauveria bassiana].

Heterokaryon of Beauveria bassiana was formed during the cross incubation of two vegetative compatible strains with genetic markers of actidione resistance and 34 degrees C tolerance. The chromosome(s) or its fragment successive losses, recombination and segreation led to haploidization during the conidia formation period. After at least 4 generations of parasexual cycle, the genetic character of heterokayon could get to relative stable. Genetic marker and RAPD analysis indicated that the combinants showed the phenomenon of preferential selection of one parental type by unrandom chromosome lossing and the gene of the other parental strain was suppressed or lost completely. Different culture medium, in vivo or in vitro, and different mixture ratio of original strain spores could affect parasexual process and then the preferential selection. The results also demonstrated the heterosis effect of cross culture.

Chromosome Deletion↗
PubMed2000

[The identification of BmNPV gp64 envelope gene].

gp64 glycoprotein, an abundant and the only membrane glycoprotein encoded by the baculovirus genome, contains a signal peptide sequence at N-terminus, a transmembrane anchor at c-terminus and a ectodomain between them. The efficient signal sequences and the transmembrane anchor sequences of AcMNPV gp64 gene have been exploited in baculovirus expression system. Using 1.3 kb AcMNPV gp64 gene coding sequence as the probe, the nucleotide sequence of BmNPV gp64 gene was determined, and a 1530 nucleotide open reading frame flanked by an AT-rich sequence was identified that could encode a polypeptide with 509 amino acid residues. Computer analysis indicated BmNPV gp64 gene is 84.3% identical to AcMNPV at the level of nucleotide sequence and 94.7% identical at the level of predicted amino acid sequence.

Amino Acid Sequence↗
PubMed2000

[The researches on titanium and titanium alloy in dental use].

Although titanium and titanium alloy have been used in dental field for several years because of their excellent biocompatibility, corrosion resistance and mechanical properties, many practical problems remain to be solved. This review focuses on the practical problems and the prospects of the researches on titanium, including the development of new titanium alloy, the surface treating, the corrosion in oral, and the processability.

Corrosion↗
PubMed2000

[Antitumor effect of the extract of birch bark and its influence to the immune function].

OBJECTIVE: To study the antitumor effect of extract of birch bark (EBB) and its influence to the immune function of the tumor-bearing mice. METHOD: EBB was administered orally and the tumor inhibiting effects were observed in tumor-bearing mice. Experiment of the immune function are to examine thymocytes (spleen) index, reaction of spleen to ConA and activity of NK cell. RESULTS: EBB showed antitumor effect in vivo to B16, S180 and Lewis lung cancer in mice. EBB can significantly prolong survival period of bearing tumor mice. EBB can enhance thymocytes and spleen index in C57 BL/6 mice. EBB can enhance splenic lymphocytes translate and activit of NK cell (P < 0.05). CONCLUSION: EBB have antitumor effect and enhance immune function in bearing tumor mice.

Adjuvants, Immunologic↗
PubMed2000

[Effects of cultivating measures on root rot of Panax notoginseng].

OBJECTIVE: To probe into the effects of cultivating measures on root rot of Panax notoginseng for the integrate control. METHOD: Field investigation on the planting plots was conducted. CONCLUSIONS: Effects of cultural system on root rot are obvious, (1) The rotation period should be more than eight years; (2) Improper fertilizer application is one important fact of the root rot occuring; (3) The light transmitting rate is one important fact; (4) Laying film and using sun-shade shed can reduce the root rot.

Fertilizers↗