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Biomedical subjects

T Zhang

Publications and source records attributed to T Zhang.

At least 235 records · Page 13Linked to original sources
PubMed1998

Cryptosporidium parvum infection of human intestinal xenografts in SCID mice induces production of human tumor necrosis factor alpha and interleukin-8.

The protozoan parasite Cryptosporidium parvum invades intestinal epithelial cells and can cause life-threatening diarrhea in immunocompromised individuals. Despite the clinical importance of this organism, much remains to be learned about the pathogenesis of C. parvum-induced diarrhea. To explore the role of the intestinal inflammatory response in C. parvum disease, using C. parvum oocysts we infected human intestinal xenografts in severe combined immunodeficient (SCID) mice. Seven days after infection, we found levels of human tumor necrosis factor alpha and interleukin-8 in C. parvum-infected human intestinal xenografts that were significantly higher than those seen in uninfected control xenografts. These results demonstrate that human intestinal cells produce proinflammatory cytokines in response to C. parvum infection and establish SCID-HU-INT mice as a model system to study the interactions of C. parvum with the human intestine.

Animals↗
PubMed1998

Results of the nationwide epidemiologic survey of Kawasaki disease in 1995 and 1996 in Japan.

OBJECTIVE: The objective of the study is to describe recent epidemiologic patterns of Kawasaki disease based on information included in patient records that had been obtained through a nationwide hospital survey in Japan. METHODS: A questionnaire and diagnostic criteria for Kawasaki disease that had been approved by the Kawasaki Disease Research Committee were sent to all pediatric departments of hospitals (2638 hospitals) with a bed capacity of at least 100. The subjects all were new patients who were treated during a 2-year period from 1995 to 1996. RESULTS: A total of 12 531 children contracted the disease during the observation period. The incidence was 102.6 for 1995 and 108.0 for 1996 per 100 000 children younger than age 5 years. The male:female ratio was 1.37. The age distribution pattern showed a peak near 6 months of age. Geographic variations in the incidence suggested the existence of local outbreaks. Cardiac sequelae were seen in 12% of the patients. CONCLUSION: More than 6000 patients suffered from Kawasaki disease each year, and its annual incidence is increasing steadily. The probable existence of local outbreaks is worthy of note. Other epidemiologic patterns were unchanged from previous years.

Age Distribution↗
PubMed1998

[Prevalence of peptic ulcer and its associated factors in elderly people in Beijing].

Survey on the prevalence rate of peptic ulcer (PU) and its associated factors in 3440 elderly people aged 60 or above, living in some area of Beijing is reported in the paper. The survey was carried out from July to October, 1993 through administration of household questionnaire. Result showed that the prevalence rate of PU was 4.1%, higher among males (5.3%) than in females (2.9%). There were more, younger, elderly and more farmers living in mountainous areas suffered from the disease than, older, elderly and rural farmers or urbanial residents. It is demonstrated that depression, intelle ctual work, cigarette smoking, heavy alcohol intake and higher educational level were correlated with the occurrence of the disease in the elderly. Neither dietary structure or light alcohol intake was found to be associated with prevalence of PU with statistical significance. We revealed that the prevalent rates of PU in the elderly were different according to age, sex, geographic area, educational level and professional aspects. The influence of psychological factors to the prevalence rate of PU should also be considered.

Aged↗
PubMed1998

Enhanced expression of HLA class I molecules in human hepatocellular carcinoma cells transduced with gamma-interferon gene.

OBJECTIVE: To investigate the expression of exogenous gamma-interferon gene in human hepatocellular carcinoma cells following retroviral transduction and the effect on the expression of surface HLA class I molecules. METHODS: Retroviral vector pLXSN was used to introduce human gamma-interferon (IFN-gamma) gene into four different human hepatocellular carcinoma cell lines (HCC). The G418-resistant colonies were isolated and cloned. The integration and expression of IFN-gamma gene were determined by PCR and RT-PCR analysis. A bioassay method was used to test the amount of IFN-gamma secreted by gene modified HCC cells. The expression of HLA class I molecules in HCC cells were analyzed by flow cytometry using indirect fluorescence staining. RESULTS: Four different HCC cell lines were successfully transduced with human IFN-gamma gene using retroviral vector. The integration and expression of IFN-gamma gene were shown only in the transduced cells. All four genetically modified HCC cells can secrete varied amount of IFN-gamma and demonstrate a significant up-regulation of surface HLA class I antigens. One specific HLA class I antigen, HLA-A2, has almost the same degree of increase as that of the total HLA class I molecules after transduction with IFN-gamma gene. CONCLUSIONS: Gene modification with IFN-gamma gene can significantly enhance the expression of HLA class I molecules in HCC cells and may increase its immunogenicity. These gene modified tumor vaccines can be helpful in tumor biotherapy.

Carcinoma, Hepatocellular↗
PubMed1998

[Reversal of cancer multidrug resistance by Chinese medicine Ams-11, Fw-13 and Tul-17].

The aim of this project was to find some kinds of Chinese materia medica as effective agents for in vitro reversal of cancer multidrug resistance. Based on the present authors' previous researches, thirty-two kinds of Chinese medicine as research meterials were selected and examined. Using cell growth inhibit assay, the authors found that three of them--Ams-11, Fw-13 and Tul-17 in the doses free from cytotoxity could enhance the sensitivity of multidrug resistant cells to anti-cancer drugs in a dose-dependent way. It seemed that these three kinds of Chinese medicine might be potential effective reversal agents.

Cell Survival↗
PubMed1998

[Molecular biological evidence for the genetic stability of in vivo passaged doxorubicin resistant cell line S-180R].

OBJECTIVE: To assess the genetic stability of doxorubicin resistant sarcoma 180 cell line(S-180R) after in vivo passages. METHODS: Flow cytometry, Southern blot, Northern blot and RT-PCR were used to examine genes and molecules related to drug resistance. RESULTS: The drug-efflux of S-180R was nearly 100-fold as high as that of the parental cells. The ratio of half peak width to peak height was 0.23 as compared to 0.56 measured two years before when the S-180R cell line was initially established. The mdr-1 gene was significantly amplified and transcribed while the transcription of topoisomerase II alpha gene was decreased. However there was no increase in mRNA expression of the multidrug resistance associated protein(MRP). CONCLUSION: Compared with the initially established S-180R, its resistance to doxorubicin is not only maintained but in fact has been increased since in vivo passage for 2 years. The major mechanism is amplification and over-expression of mdr-1 gene, but decreased topoisomerase II alpha also contributes. S-180R is an ideal experimental model for the study of doxorubicin resistance and its reversion.

ATP-Binding Cassette Transporters↗
PubMed1998

[Influence of fry-processing on outward character and inner quality of volatile oil containing drugs such as fructus Viticis, etc].

According to the requirement of outward character in processing traditional Chinese drugs, five volatile oil containing drugs Fructus Viticis, Rhizoma Atractylodis Macrocephalae, Rhizoma Cyperi, Fructus Foeniculi and Fructus Aurantii were fry-processed. The conditions of frying technology were measured; the amounts of volatile oil before and after processing were determined with accurate volatile oil extractor; and the volatile oil in Rhizoma Atractylodis Macrocephalae and Fructus Aurantii was analyzed by means of GC.

Apiaceae↗
PubMed1998

[A study of prognostic factors in breast cancer: histological grading].

OBJECTIVE: To study the significance of histological grading as a prognostic factor in breast cancer. METHODS: According to the grading systems of Bloom-Richardson and Elston, 476 cases of invasive ductal carcinoma (IDC) with more than 5 year follow-up were assessed for grade I (GI, 72 cases), grade II (G II, 216 cases) and grade III (G III, 188 cases). RESULTS: The 5 year survival rate for IDC G I, G II and G III were 81.9% (59 cases), 63.4% (137 cases) and 49.5% (93 cases) respectively. CONCLUSION: Histological grading of IDC is as good a prognostic factor as their clinical stage.

Breast Neoplasms↗
PubMed1998

[The role of cytokeratin 7 in the differential diagnosis of primary ovarian carcinoma and metastatic ovarian carcinoma originated from the gastrointestinal tract].

OBJECTIVE: To assess the role of cytokeratin 7 monoclonal antibody in the differential diagnosis of primary ovarian carcinoma and metastatic ovarian carcinoma originated from the gastrointestinal tract. METHODS: Immunohistochemical study using cytokeratin 7 monoclonal antibody and ABC kit. RESULTS: All the 46 cases of primary ovarian carcinoma were CK 7 positive, while in the metastatic ovarian carcinoma of intestinal origin, all cases remained negative for CK7. Half of the 34 cases of metastatic ovarian carcinoma of gastric origin were CK 7 positive. The positive result of CK7 was significantly higher in the primary ovarian carcinoma than in each group of the metastatic ovarian carcinoma (P < 0.001). CONCLUSION: CK 7 is seemed to be a useful antibody in the differential diagnosis of ovarian carcinoma.

Antibodies, Monoclonal↗
PubMed1998

[Clinical observation on preventing and treating coronary atherosclerotic heart disease with tongmai jiangzhi oral liquid].

OBJECTIVE: To observe the clinical effect of Tongmai Jiangzhi Oral Liquid (TJOL) on blood lipid, lipid peroxidation, prostaglandin metabolism in treating coronary heart disease and angina pectoris with hyperlipidemia. METHODS: Forty-one cases in treated group and 24 in control group were treated with TJOL and Capsulae Oenoth Erae Biennisolei (COEB) for one month respectively. Serum lipid, apolipoprotein, plasma malonyldialdehyde (MDA), superoxide dismutase (SOD), thromboxane B2(TXB2), 6-keto-prostaglandin F1 alpha and blood glutathione peroxidase (GSH-Px) were measured before and after treatment. RESULTS: After treatment with TJOL, the total effective rate was 87.80% in relieving angina and 50.00% in improving ECG. Other data showed that the levels of serum TC, TG, apoB, plasma MDA, TXB2 and TXB2/6-keto-prostaglandin F1 alpha ratio lowered and levels of apoA, GSH-Px, serum HDL-C, apoA1/apoB increased (P < 0.05-P < 0.001). CONCLUSIONS: TJOL could effectively lower blood lipid, reduce injury caused by free radicals, regulate prostaglandin metabolism and treat coronary heart disease. By this study, an effective prescription of Chinese herbal medicine was offered for prevention and treatment of coronary heart disease.

Adult↗
PubMed1998

[Experimental study of hirudo and Salvia miltiorrhiza on smooth muscle cell hyperplasia after balloon angioplasty].

OBJECTIVE: To find the preventive method of restenosis after transluminal angioplasty (TA). METHODS: Sixty rabbit iliac arteries of 30 rabbits were divided randomly into three groups, group A, B and C, 20 in each. After experimental atherosclerotic stenosis and TA performing, ordinary forage plus 2 g of hirudo powder was fed to the group A every day, to the group B, 2 g Salvia miltiorrhiza powder was added and to the group C, ordinary forage only. Angiography and pathomorphological examination were carried out 30 days later. RESULTS: (1) Hirudo significantly reduced the thickness of iliac intima as compared with the other two groups (P < 0.05), the thickness in the group A, B and C was 40.1 +/- 9.8 microns, 48.2 +/- 8.2 microns and 69.3 +/- 9.2 microns respectively. (2) The incidence of restenosis after TA in both group A (31.4%) and group B (48.4%) were significantly lower than that in the group C (62.8%, P < 0.05). And significant difference was also found in comparison of group A and group B (P < 0.05). (3) Ultrastructure change examined by transmission electron microscopy showed that less rough endoplasmic reticulum and more myofilaments in well differentiated smooth muscle cell (SMC) of the arterial intima in the group A and B, while in the group C, more rough endoplasmic reticulum, more synthetic cells were seen in SMC. CONCLUSIONS: Hirudo and red sage root could effectively inhibit the hyperplasia of SMC in arterial intima and reduce the intima thickness and the incidence of restenosis after TA significantly, thus might play a role in the prevention of restenosis after TA. The effect of hirudo is more potent than that of red sage root.

Angioplasty, Balloon, Coronary↗
PubMed1998

[Separation of alkaloids in tea by high-speed counter-current chromatography].

Alkaloids extracted from the green tea were separated by high-speed counter-current chromatography. A series of experiments have been performed to investigate effects of different solvent system. A system of CHCl3-CH3OH-NaH2PO4(23 mmol/L) = (4:3:2) was selected, in which the upper phase was used as the stationary phase, and the lower phase as mobile phase. When acidity of solvent system is pH 5.6, three chemical components are very efficiently isolated by one injection of 50 mg sample mixture. Analyzing the eluted fractions by TLC, we know that one is caffeine, and the other is theophylline. In comparing the separation results by high-speed counter-current chromatography with those by TLC, the advantages of this method is verified. It should find wide applications of this technology for the separation of crude mixture of plant components.

Alkaloids↗
PubMed1998

[Chemical shifts of CrKbeta peaks in XRF spectra by Si(Li) spectrometry].

The energies of CrKbeta X-Rays in metel Cr, Cr2Os and K2CrO4, which are excited respectively by gamma-ray 59.6keV from radioactive source 241Am, have been measured by Si(Li) spectrometry. It is shown in the experiment that the peak of CrKbeta X-ray in K2CrO4 shifts 2.12 +/- 0.27eV compared to that in metel Cr.

English Abstract↗
PubMed1998

[Geographical distribution of medical expenditure for the aged insured by National Health Insurance in secondary medical care areas in Japan].

PURPOSES: To determine what factors affect medical expenditure for the aged insured by the National Health Insurance among secondary medical care areas. METHOD: The original data of municipalities were combined and converted into the data of secondary medical areas. The original data included medical expenditure of the aged in 1994, medical supply factors per 100,000 population (numbers of doctors, numbers of general beds in hospitals, numbers of clinics, etc.) and socio-economic factors (income, proportion of employees for three sectors of industries, population density, average size of family, etc.). Medical expenditures for inpatients and outpatients were used separately as independent variables. The medical supply and socio-economic factors have been used as dependent variables. Multiple regression models were applied to clarify the differences in the contributing factors between inpatient and outpatient. RESULTS: 1. The maximum inpatient and outpatient medical expenditures for the aged are respectively 4 times and 2.6 times more expensive than minimum expenditures among secondary medical care areas. 2. The numbers of beds, income per capita, numbers of doctor, average size of family, proportion of employees for third level industry and income accounted for 57.4% of variance in inpatient medical expenditure of the aged. 3. The proportion of employees for first level industry, the numbers of beds and average members of family accounted for 21.4% of variance in outpatient medical expenditure of the aged. 4. Medical expenditure for inpatients related with medical supply and socioeconomic factors differently from that of outpatients.

Aged↗
PubMed1998

Dissociation of creatine kinase under different denaturation conditions.

Dissociation of dimeric creatine kinase under different denaturation conditions was investigated using the cleavable cross-linker 3, 3;-dithiobis(succinimidyl propionate). The results show that at low denaturant concentrations or at low denaturation temperatures the creatine kinase was mostly inactivated, but the enzyme was still either in the dimeric state or very slightly dissociated. It appears, therefore, that for several denaturation conditions, inactivation of the enzyme is not due to the dissociation of the active dimer.

Animals↗
PubMed1997

The mammalian protein (rbet1) homologous to yeast Bet1p is primarily associated with the pre-Golgi intermediate compartment and is involved in vesicular transport from the endoplasmic reticulum to the Golgi apparatus.

Yeast Bet1p participates in vesicular transport from the endoplasmic reticulum to the Golgi apparatus and functions as a soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) associated with ER-derived vesicles. A mammalian protein (rbet1) homologous to Bet1p was recently identified, and it was concluded that rbet1 is associated with the Golgi apparatus based on the subcellular localization of transiently expressed epitope-tagged rbet1. In the present study using rabbit antibodies raised against the cytoplasmic domain of rbet1, we found that the majority of rbet1 is not associated with the Golgi apparatus as marked by the Golgi mannosidase II in normal rat kidney cells. Rather, rbet1 is predominantly associated with vesicular spotty structures that concentrate in the peri-Golgi region but are also present throughout the cytoplasm. These structures colocalize with the KDEL receptor and ERGIC-53, which are known to be enriched in the intermediate compartment. When the Golgi apparatus is fragmented by nocodazole treatment, a significant portion of rbet1 is not colocalized with structures marked by Golgi mannosidase II or the KDEL receptor. Association of rbet1 in cytoplasmic spotty structures is apparently not altered by preincubation of cells at 15 degrees C. However, upon warming up from 15 to 37 degrees C, rbet1 concentrates into the peri-Golgi region. Furthermore, rbet1 colocalizes with vesicular stomatitis virus G-protein en route from the ER to the Golgi. Antibodies against rbet1 inhibit in vitro transport of G-protein from the ER to the Golgi apparatus in a dose-dependent manner. This inhibition can be neutralized by preincubation of antibodies with recombinant rbet1. EGTA is known to inhibit ER-Golgi transport at a stage after vesicle docking but before the actual fusion event. Antibodies against rbet1 inhibit ER-Golgi transport only when they are added before the EGTA-sensitive stage. These results suggest that rbet1 may be involved in the docking process of ER-derived vesicles with the cis-Golgi membrane.

Amino Acid Sequence↗
PubMed1997

IL-18 protects mice against pulmonary and disseminated infection with Cryptococcus neoformans by inducing IFN-gamma production.

We examined the effects of a newly identified cytokine, IL-18, originally designated as IFN-gamma-inducing factor, in a mouse model of pulmonary and disseminated infection with a highly virulent strain of Cryptococcus neoformans. Administration of murine rIL-18 enhanced elimination of live micro-organisms from the lungs, prevented fungal dissemination to the brain, reduced the level of serum cryptococcal capsular polysaccharide Ags, and increased the survival rate of infected mice. Histologic examination of lung sections of infected and PBS-treated mice showed a poor cellular inflammatory reaction and a large number of multiplying C. neoformans yeast cells in alveolar spaces. In contrast, massive infiltration of inflammatory cells, consisting mainly of mononuclear cells, characterized sections of lungs of infected animals treated with IL-18. Treatment with IL-18 also increased the level of serum IFN-gamma. In addition, the protective effect of IL-18 on cryptococcal infection was abrogated by administration of neutralizing anti-IFN-gamma mAb. Finally, we examined the effect of neutralizing anti-IL-18 Ab on cryptococcal infection to define the physiologic role of this cytokine in host defense using another weakly virulent strain of C. neoformans, which induced the expression of IL-18 mRNA in the infected lungs. Administration of this Ab exacerbated the infection, as shown by the increased lung burden. Our results indicate that IL-18 plays an important role in host defense against infection with C. neoformans.

Animals↗