Biomedical subjects

W Zhang

Publications and source records attributed to W Zhang.

At least 541 records · Page 30Linked to original sources

PubMed2000

[Retrospective cohort study on the prognosis of chronic myeloid leukemia].

OBJECTIVE: To evaluate the prognostic factors of chronic myeloid leukemia (CML). METHODS: Survival curves were plotted according to the Kaplan-Meier method. Variables associated with prognosis were analyzed by Logrank test. A multivariate analysis of prognostic factors was performed using stepwise Cox model. RESULTS: Of the total 158 patients, the median survival time was 1,480 days. 5 years survival rate was 47.1% (95% CI, 36.7% - 56.9%). 10 years was 24.8% (95% CI, 15.0% - 35.8%). The predominant blastic crisis type is myeloblastic, myelomonocytic or monocytic(77.5%). The period from chronic phase to blastic phase was equal in myelosuppressive therapy group, non- myelosuppressive therapy group or altretamine (HMM) group. After evaluated by stepwise Cox's regression model, age>or=50 years, bone marrow blasts>or=0.05, bone marrow basophilic>or=0.05, Ph chromosome negative and HMM treatment were associated with poor prognosis. Hydroxyurea was always associated with longer survival. CONCLUSION: Age, Ph chromosome, bone marrow blasts and basophilic, and various treatment affected the survival of CML.

Adult↗

PubMed2000

[The role of matrix vesicles during development of the mineralizing tissues of tooth germ and craniofacial bone].

OBJECTIVE: To evaluate the role of matrix vesicles (MVs) during the development of mineralizing tissues. METHODS: The ultrastructure of MVs of tooth germ, calvarial bone and mandibular bone were observed by transmission electron microscopy in fetal Wistar rat. RESULTS: (1) The MVs were formed by osteoblast of the secret type, dentinoblast and process; (2) There was a mature process of the MVs in the extracellular matrix. The appearance of the hydroxyapatite (HAP) was a major mature feature; (3) HAP formed initially in the MVs entered into collage matrix and eventually mineralized; (4) The shifting sign of HAP from MVs to the surface of collage fibril was observed. CONCLUSIONS: The MVs played an important role in the biomineralization, but the special arrange pattern of mature collage fiber provided a suitable environment and a model to the growth of HAP for further mineralization.

Animals↗

PubMed2000

[Experimental and clinical study of gentamicin-loaded chitosan drug delivery system].

OBJECTIVE: To conduct a clinical study and release test for a drug delivery system (DDS) of gentamicin-loaded chitosan bar in attempt to extend its clinical application. METHODS: The diffusion behavior of gentamicin from chitosan DDS was detected using in vitro, in vivo release test. Eighteen cases of chronic osteomyelitis were treated by chitosan DDS. The clinical result was evaluated by wound healing and clinical and X-radiographic manifestation. RESULTS: Concentration of gentamicin about 926.7 microg/bar/day was released from DDS within the first 24 hours by in vitro diffusion test. It fell and sustained by 25th day with rate of 4.0 microg x bar(-1) x day(-1). In in vivo study, serum gentamicin concentration reached its peak level (0.92 microg/ml) 24 hours after implantation. No increase was observed in the concentration of BUN and Cr. In all bone tissue around the bar, 8 weeks after oderation the gentamicin concentration exceeded the minimum inhibitory concentration for the common causative organisms of osteomyelitis. The follow up time was 24.8 months (6 - 34). The initial cure ratio was 2/18 and the recurrence ratio zero. CONCLUSION: The gentamicin-loaded chitosan bar is a good DDS with sustained antibiotic effect in vivo and in vitro. It is an effective method for the treatment of bone infection.

Animals↗

PubMed2000

[Transposition of bilateral pedicled adrenal gland for the treatment of Cushing's disease].

OBJECTIVE: To study the therapeutic method of Cushing's disease. METHODS: 16 patients with Cushing's disease were treated by transposition of bilateral pedicled adrenal gland into the dorsal subcutaneous tissues. RESULTS: These patients were followed up for 4 to 48 months. No relapse was observed and 3 patients with hypoadrenocorticism were given small doses of steroid. CONCLUSIONS: This procedure may be a rational and satisfactory technique for the treatment of Cushing's disease.

Adolescent↗

PubMed2000

[An experimental study on treatment of limbal alkali burn by allograft transplantation with cultured stem cells on amniotic membrane].

OBJECTIVE: To study the treatment of rabbit limbal alkali burn by cultured limbal stem cells growing on amniotic membrane for allograft transplantation. METHODS: After the primary culture of the rabbit corneal stem cells, they were cultured on amniotic membrane in DMEM/HamF12 medium for one week. Corneal stem cells and amniotic membrane were transplanted on the limbal and scleral area of the rabbit model with alkali burn. The corneal changes were observed by a slitlamp everyday, and the corneal pathological changes were examined. RESULTS: Cultured rabbit corneal stem cells continued to proliferate, differentiate and form multiple cell layers on amniotic membrane. After transplantation with cultured stem cells and amniotic membrane, the rabbit epithelium showed corneal phenotype and progressive decrease of vascularity and stromal infiltration in the limbal and peripheral zone. Pathological examination verified that the limbal and peripheral corneal epithelium was composed of multilayer cells, the neo-vascularization was reduced and stromal inflammatory cells were decreased. CONCLUSIONS: Allograft transplantation with cultured limbal stem cells can restore corneal epithelial cell composition, decrease neovascularization, maintain limbal cellular barrier function and provide better condition for keratoplasty later.

Alkalies↗

PubMed2000

[Point mutations of N-ras oncogene and abnormal expression of rasp21, p53 proteins in orbital rhabdomyosarcoma].

OBJECTIVE: The point mutations of N-ras oncogene and the abnormal expression of rasp21 and p53 proteins in orbital rhabdomyosarcoma (RMS) were analyzed in order to explore the role of oncogene mutations in the pathogenesis of orbital RMS and its relation to patients' prognosis. METHOD: 21 human orbital RMS tissues were analyzed by dot-blot hybridization and immunohistochemistry using synthetic specific oligonucleotide probes and mutant rasp21, p53 monoclonal antibodies. RESULTS: The second base mutation of codon 12 of the N-ras oncogene was found in 4 patients. The third base mutation of codon 61 was found in 5 patients. The mutant rate was 33.3%. By immunohistochemistry analysis, the overexpression of rasp21 and p53 protein level was found in 42.9% and 76.2% respectively. The prognosis of patients with overexpression of ras p21, p53 was worse than that of normal expression (P < 0.01). CONCLUSION: The mutants of ras and p53 oncogene play important roles in the pathogenesis of orbital RMS, and the abnormal expression of their protein products is related to patients' prognosis.

Adolescent↗

PubMed2000

[Toxic effects of aluminum on human embryonic cerebral neurocytes in vitro studies].

OBJECTIVE: To study the toxic effect of aluminum on human embryonic cerebral neurocytes in vitro studies. METHODS: Human embryonic cerebral neurocytes were divided into three groups (control, low Al and high Al groups). The growth, development and morphology of neurocytes were observed by light and electron microscopy. The protein, DNA, lipid peroxide (LPO) contents and the activity of neuron-specific enolase (NSE) and cholinesterase (CHE) of neurocytes were detected. RESULTS: The number of viable cells in high Al group was significantly lower than that in the control group (P < 0.05). The number of swelling, degenerated and necrotic cells was significantly increased in high Al group. The DNA content and the activity of NSE and CHE of neurocytes were significantly decreased with the increase of Al concentrations (P < 0.05). The LPO content of neurocytes in the high Al group was significantly higher than that in the control group (P < 0.05). There was a positive correlation between the Al dose and LPO content of neurocytes (P < 0.05). The electron microscopy study showed that the membrane structure of cell was damaged in the high Al group and the arrangement of microtubules in the processes was disordered. CONCLUSIONS: The growth, development and function of human embryonic cerebral neurocytes was inhibited in the high Al group. The neurotoxicity of Al may be caused by lipid peroxidation and the damage of cell membrane.

Aluminum↗

PubMed2000

[Telomerase activity in human non-small cell lung cancer (NSCLC)].

OBJECTIVE: To investigate the activity of telomerase in human non-small cell lung cancer (NSCLC) and the correlation of telomerase activity with the cancer development. METHODS: Totally 48 cases of NSCLC tissues were studied accompanied with 7 cases of normal lung tissues and 12 samples of lung tissues adjacent to the tumor. The telomerase activity was detected using Telomerase PCR ELISA kit. Statistics study included chi(2)-test and the exact probabilities. The significance level chosen was P value less than 0.05 (P < 0.05), and all tests were two-sided. RESULTS: 75% (36/48) of NSCLC tissues possessed the expression of telomerase activity and only 8.33% (1/12) of tissues adjacent to tumor and none of the normal lung tissue enabled to express telomerase activity. The statistical difference was significant (P < 0.05). No significant difference was found between different histological types of NSCLC, however, the frequency of telomerase expression differed significantly between tumors of well/mordeately differentiated and poorly differentiated; stage I and stage II/III. CONCLUSION: Telomerase activity might be a good marker in estimating the occurrence, development and diagnosis of NSCLC.

Adenocarcinoma↗

PubMed2000

[Inhibition of hTR activity for suppression of lung cancer cell proliferation using antisense phosphorothioate oligonucleotides].

OBJECTIVE: Telomerase activity was measured in 8 lung tumor cell lines and transfected antisense phosphorothiate oligodeoxynucleotides (anti-PS-ODN) of hTR as therapeutic agents into target cell LTEP-a-2 to investigate the inhibitory effect on telomerase activity and tumor cell growth. METHODS: 1. Telomerase activity assay in 8 human lung tumor cell lines using telomerase PCR ELISA. 2. Synthesized anti-PS-ODNs of hTR and random PS-ODN transfected with Clonfectin into LTEP-a-2 cell lines for 72 hr. 3. Measure telomerase activity by telomerase PCR ELISA, SDH activity by MTT assay and cell growth. RESULTS: Eight cell lines showed positive expression of telomerase activity. Various anti-PS-ODNs could inhibit telomerase activity, SDH activity and cell growth. The inhibition became more marked with the increase of anti-PS-ODNs concentrations. Concentrations of 5 - 40 micromol/L anti-PS-ODNs of hTR specifically reduced the telomerase activity by 25.7% - 84.0%. PS-ODNs of anti-hTR were also able to reduce SDH activity by 19.4% - 74.7% at 5 - 40 micromol/L. The dose of 5 - 40 micromol/L PS-ODNs of anti-hTR had the ability to inhibit cell growth by 14.8% - 72.5%. The results indicate that random sequence of PS-ODN(9) failed to inhibit telomerase, SDH activity and cell growth. A statistically significant difference exists between random PS-ODN and three anti-PS-ODNs (P < 0.01). CONCLUSIONS: Human lung tumor cell lines express high telomerase activity. PS-ODNs of anti-hTR had the ability to inhibit telomerase and reduce LTEP-a-2 cell growth and metabolism.

Adenocarcinoma↗

PubMed2000

[Construction and transient expression of an Ala 737-->Glu mutant of vWF].

OBJECTIVE: To study the functional change of an Ala737-->Glu substitution mutant of vWF and the molecular pathological mechanism of this mutant in the type 2A vWD. METHODS: The expression plasmid pSVvWF containing full-length cDNA of vWF was used to site direct mutagenesis by polymerase chain reaction (PCR) and transitorily expressed in the COS-7 cells, vWF: Ag in the supernatant and the cell lysate between wild type and pSVAla737Glu vWF were measured. vWF polymers of the platelet of the patient with the mutation and response to DDAVP treatment of the patient were observed. RESULTS: vWF: Ag level of pSVAla 737Glu vWF was 76.4% and 98.8% of the wild types in the supernatant and cell lysate, respectively. The polymer pattern of extracellular pSVAla737Glu vWF was indistinguishable from that of the wild type, containing all kinds of molecular weight. Increased vWF antigen levels was observed in the patients after DDAVP treatment. CONCLUSION: This mutant did not change the assembly and secretion of vWF. The mutant of vWF Ala737-->Glu resulted in Group II type 2A vWD.

Animals↗

PubMed2000

[Quantitative determination of EAIgG by ABC-ELISA and its clinical significance].

OBJECTIVE: To explore a method for diagnosis of autoimmune hemolytic anemia (AIHA) and evaluate its clinical significance. METHODS: Erythrocyte associated IgG (EAIgG) was quantified in 60 healthy people, 44 patients with warm antibody AIHA (WAIHA), 108 non-immune anemia and 44 other immune diseases (total 256 cases) by using ABC-ELISA were estimated. RESULTS: EAIgG in WAIHA patients were significantly higher than those in other groups (P < 0.01). In the 44 WAIHA patients, 38 were Coombs positive and 6 Coombs negative. EAIgG in Coombs negative was significantly high. The dynamic changes of EAIgG in 12 WAIHA patients were observed during treatment. When patient's condition got better, Hb and RBC increased and EAIgG decreased. CONCLUSION: Quantitative detection of EAIgG is an index in the diagnosis of WAIHA, especially in AIHA with negative Coombs' test. It is also a useful factor for evaluating therapeutic effect and prognosis in WAIHA.

Adolescent↗

PubMed2000

[GABA inhibits progesterone production of luteal cells of rat ovary].

In the present work we report that GABA inhibits progesterone production and increases the amount of hydroxyl radical in cultured rat luteal cells. The inhibitory effect of GABA on progesterone production may be mediated by adenylate cyclase system and GABA(A) receptor, but not through protein synthesis pathway.

Adenylyl Cyclases↗

PubMed2000

[Re-evaluation of proteinuria and qualitive methods for diagnosis of diabetic nephropathy].

This study was aimed to re-evaluate the proteinuria quantitative and qualitative methods for diagnosis of diabetic nephropathy (DN). 136 cases were divided into two groups of proteinuria negativeness and postiveness by the results of urine routine examination. The clinical and biochemical indices and the frequencies of other diabetic complications of the two groups were compared. The results showed that the blood glucose and glycated Hb in the two groups were increased, especially in the proteinuria negative group (P < 0.01 and 0.05, respectively). There was a high prevalence of hypertension and other diabetic complications in the two groups, and it was higher in the positive group than in the negative group (P < 0.05 and 0.01, respectively). The frequencies of hyperlipoproteinemia in the two groups were over 40%, but no significant defference was observed between them (P > 0.05). There was correlation between hypertension and proteinuria (P < 0.01) but no correlation between diabetic retinopathy and proteinuria. The prevalence of azotemia in the proteinuria negative group was 17.07%. These suggest that the amount of proteinuria can not completely reflect the duration and severity of DN. Negative proteinuria in routine examination cannot rule out DN. For diagnosis of DN, it is necessary to think about all data on blood glucose, blood lipid, blood pressure and the change in fundus oculi.

Adolescent↗

PubMed2000

[The effect of cardiopulmonary bypass on expression of myocardial nitric oxide synthase in patients for valve replacement].

The objective of this study was to assess the effect of cardiopulmonary bypass (CPB) on expression of nitric oxide synthase (NOS) in patients for valve replacement. Ten adult patients were included in this study. CPB was initiated with a bubble oxygenator, aorta was clamped, and cold crystalliod cardioplegia was delivered into the aortic root. The myocardium of atrial appendage was obtained pre-CPB and 45 minutes post-CPB. The expression of three kinds of NOS isoenzymes was assessed by immunohistochemistry and microcomputerized image analysis. The results demonstrate that there are expression of nNOS (nervous NOS), iNOS (inducible NOS) and eNOS (endothelial NOS) in the atrial myocardium of patients for valve replacement. Compared with the expressions of NOS pre-CPB, the post-CPB expression of nNOS increased and that of eNOS decreased (P < 0.05), but no significant change in expression of iNOS was noted(P > 0.5). We belive that the decreased expression of eNOS may be related with the deficiency of nitric oxide release and may be responsible for tissue damage during CPB.

Adult↗

PubMed2000

[Analysis on skin allergy of rural residents in Anqing area].

To investigate the allergy reaction of rural residents against 12 categories sensibiligen, 9,232 sensibiligen peasants from rural areas of Anqing were observed by 12 categories sensibiligen in skin(methods: point thron). If the diameter of papule erygthema was bigger than that of histamines of control, the reaction was considered to be positive. All cata was analyzed by sas software. The results showed that the allergy reaction degrees were different among the groups with different genders and ages. Family susceptibility was noticed.

China↗

PubMed2000

[Effect of chromium gluconate on body weight, serum leptin and insulin in rats].

In order to observe the effect of chromium on rat body weight, serum leptin and insulin, eight groups of rats were randomly fed diets (basal diet or high-fat diet) with different levels of chromium gluconate [proximally Cr(III) 1,2 and 3 mg/kg BW]. All rats were weighted once a week. By the end of the 8th week, all rats were decapitalized and the levels of serum leptin and insulin were tested by RIA method. The ratio of liver, spleen, kidney and testickle to body weight were calculated. The average body weight and the levels of leptin and insulin of high-fat-diet groups were significantly higher than those of the basal-diet group (P < 0.05), but the insulin and leptin of groups with chromium were significantly lower than their corresponding control groups without chromium(P < 0.05). It was concluded that chromium could cause weight loss slightly and reduce the levels of insulin and leptin.

Animals↗

PubMed2000

[Hygienic status of deep fried oils in 1998 and the contrast with 10 years ago].

The hygienic status and influence factors of deep fried oil were studied. The samples from 29 individual producers, 38 state-operated or cooperated restaurants and 30 joint-invested enterprises were collected to investigate the hygienic condition on the spot, and to analyze the acid value(AV), carbonyl value (COV) and polar compound(PC) with national standard methods(GB). The data showed that the degree of rancidity of the deep fried oils varied with different types of oil, refinement of oil and the kind of fried food. Comparing with the results obtained a decade ago, COV was decreased while PC was increased. It was suggested: (1) to specify some types of oil for flying foods; (2) to develop some quick methods for checking fried oil; (3) to improve the method for detecting PC for solid oil at ordinary (indoor) temperature; (4) to study the quality and safety of fried foods prepared by solid oils.

Acids↗

PubMed2000

[Studies on thymidine kinase gene (TK) and GCV system for treatment of human retinoblastoma (RB)].

The antitumor effect of herpes simplex virus thymidine kinase (HSV-TK)/GCV system on human retinoblastoma (RB) was studied here. A retroviral vector with tk gene (pLXSN-TK) was transduced into packaging cell line PA317. Recombinant retroviral was obtained and employed to infect human RB cells. The in vitro efficacy of TK/GCV was evaluated by survival rate of RB cells with and without TK transduced 5 days after treated with GCV. A nude mouse model with heteroplantation of human RB was established to examine the in vivo efficacy. Mice with RB were given an in situ injection of retrovirus followed by treatment with GCV for 14 days (50 mg/kg). The RB/TK cells in tissue culture dish showed far more sensitive to GCV than RB cells. The tumors in RB mice with TK gene transduced were much smaller than those in control. The results indicate that HSV-TK/GCV system can suppress growth of RB both in vitro and in vivo. It could be a valuable method for treatment of RB patients.

Animals↗