Biomedical subjects

C Zhang

Publications and source records attributed to C Zhang.

At least 181 records · Page 10Linked to original sources

PubMed2001

[Experiment observations of the germicidal effects of disinfectants on Vibro cholerae of El Tor biotype in different water bodies].

OBJECTIVE: To study the germicidal effect of disinfectant on vibro cholerae of El Tor biotype in different water bodies and to set a guidelines for disinfection in the epidemic foci of cholera. METHODS: The suspension quantitative bactericidal test was used to examine the germicidal effects of four kinds of disinfectants, including Chlorine compound disinfectant, Indophor, Chlorine dioxide and Glutarldehyde, on vibro cholerae of El Tor biotype in waste water from residential areas and hospitals, and water from ditches, rivers and seas. RESULTS: When germicidal rate for Vibrio Cholerae of El-Tor biotype in the five different kinds of water bodies reached to 100% in five minutes, concentrations of Chlorine compound disinfectant, Indophor, Chlorine dioxide and Glutaraldehyde were 25.0-250.0 mg/L, 100.0-250.0 mg/L, 10.0-25.0 mg/L and 100-500 mg/L, respectively. CONCLUSIONS: Germicidal effects of the four kinds of disinfectants on Vibrio Cholerae of El-Tor biotype differed, and so did germicidal effect of each of the same disinfectant on it in the five different kinds of water bodies. Concentrations of disinfectants needed to disinfected waste water was higher than that to disinfect natural water.

Chlorine Compounds↗

PubMed2001

Relationship between gene polymorphism of the PAI-1 promoter and myocardial infarction.

OBJECTIVE: To investigate the association between gene polymorphism of the plasminogen activator inhibitor-1 (PAI-1) and myocardial infarction (MI) in Chinese. METHODS: PAI-1 genotyping with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and allele specific polymerase chain reaction (ASPCR) was performed in 87 myocardial infarction patients and 92 unrelated healthy controls. All subjects' clinical features and PAI-1 activity were tested. RESULTS: There were two polymorphisms within the promoter, a G/A single base substitution polymorphism upstream at -844 bp, and a single guanosine deletion/insertion 4G/5G polymorphism -675 bp upstream from the start of transcription. Significant differences between the patients and the controls were observed neither for the frequencies of the GG, GA and AA genotypes nor for the PAI-1 activities of these three types. But for the 4G/5G polymorphism, there were significant differences between patients and controls for the frequencies of the 4G/4G, 4G/5G and 5G/5G genotypes (P < 0.05). In the MI group, the PAI-1 activity of the 4G/4G type was significantly higher than that of the 5G/5G type (P < 0.05). Further more, a positive correlation between the glucose level and PAI-1 activity was found (r = 0.34, P = 0.02). CONCLUSION: This study indicates that the 4G/5G gene polymorphism of PAI-1 is associated with myocardial infarction, that 4G/4G type is probably an important hereditary risk factor, and that glucose has functional importance in regulating PAI-1 activity.

Adult↗

PubMed2001

Pathogen of root surface caries in the elderly.

OBJECTIVE: To study the pathogen of root surface caries in the elderly. METHODS: Plaque samples from the experimental group and the control group were collected. After culturing in selective and non-selective media, the different bacteria were isolated. The counts and the positive rates of total bacteria, porphyromonas group, pervotella group, streptococcus mutants group, actinomyces group and lactobacillus group were compared. RESULTS: The counts of total bacteria, streptococcus mutants, actinomyces and lactobacillus of the experimental group were higher than those of the control group. The positive rates of actinomyces and lactobacillus of the experimental group were significantly higher than those of the control group. CONCLUSION: Actinomyces and lactobacillus are the main related pathogens of root surface caries in the elderly.

Actinomyces↗

PubMed2001

[Expression level of c-erbB-2 protein correlates with the prognosis of patients with colorectal cancer].

OBJECTIVE: To study the expression level of c-erbB-2 gene in colorectal cancer and its correlation to prognosis. METHODS: In 173 colorectal carcinoma patients, c-erbB-2 protein was examined immunohistochemically and patients' prognosis was evaluated by retrospective analysis combined with follow-up data. RESULTS: The immunohistochemical staining of c-erbB-2 protein was found in the cytoplasm and membrane with a positive rate of 52% in tumor tissue. The 1-, 3-, 5- and 10-year survival rate of patients with negative c-erbB-2 expression was 98.7%, 92.4%, 87.1% and 84.1% respectively; that of the patients with weakly positive c-erbB-2 expression was 94.5%, 76.1%, 72.3% and 68.3%, respectively. In contrast, that of patients with strongly positive c-erbB-2 expression was 91.0%, 43.5%, 36.8% and 23.4%, respectively. The survival rates among the three groups of patients were statistically different. Multivariate survival analysis by Cox regression model showed that c-erbB-2 expression level was a risky prognostic factor for colorectal cancer. CONCLUSION: The expression level of c-erbB-2 protein is an independent prognostic factor in colorectal carcinoma.

Adult↗

PubMed2001

Comparison of estrogen and androgen levels after oral estrogen replacement therapy.

OBJECTIVE: To assess the extent of accumulation of circulating estrone (E1), total and free estradiol (E2) and estrone sulfate (E1S) levels in postmenopausal women receiving prolonged oral E2 therapy and to determine the effect of increased estrogenicity on free testosterone levels. STUDY DESIGN: Descriptive study involving 14 healthy postmenopausal women during a three-year period. Group 1 (n = 7) took a placebo. Group 2 (n = 7) took 1 mg micronized E2 daily. Blood samples were taken at one, two and three years. E2, E1 and total testosterone were quantified by radioimmunoassay (RIA) following extraction and celite chromatography. Free testosterone and E2 were calculated. Sex hormone-binding globulin (SHBG) and E1S were quantified by RIA. RESULTS: In the control group, none of the hormone levels changed significantly. Free testosterone decreased 49% in women taking E2 replacement as compared to a 7% decline in women taking placebo. In women taking E2 replacement, E1, E2, E1S, free E2 and SHBG levels increased 10, 6, 51, 2 and 2 times, respectively, between baseline and year 3. CONCLUSION: E1, E2 and E1S levels significantly increased with E2 replacement. Free testosterone levels decreased with E2 replacement. Testosterone replacement may be warranted when giving postmenopausal women estrogen replacement therapy.

Administration, Oral↗

PubMed2001

Early diagnosis and monitoring of active HCMV infection in children with systemic lupus erythematosus.

OBJECTIVE: To investigate the prevalence and features of active human cytomegalovirus (HCMV) infection in children with systemic lupus erythematosus (SLE) and evaluate the diagnostic value of the HCMV using antigenemia assay, serum polymerase chain reaction (PCR) and serology test. METHODS: Twenty-one SLE children undergoing immunosuppressive therapy were enrolled in this study. Immunofluorescence assay, PCR and serology tests were used to determine HCMV pp65 and p72 antigens in leukocytes, HCMV DNA in sera, and HCMV specific IgM and IgG antibodies, respectively. As a control group, twenty-one immunocompetent children with skeletal malformation were involved in this study. Statistical analysis was performed using Chi-square test or Fisher's exact test (Systat, USA), P values less than 0.05 were considered significant. RESULTS: Active HCMV infection was diagnosed in 28.6% (6/21) of SLE patients, with none in the control group; the difference between the two groups was significant (P = 0.027). Two out of 6 SLE patients developed active HCMV infection before immunosuppressive therapy and the remaining 4 patients developed SLE after immunosuppressive therapy. Among the 21 SLE children, HCMV pp65 antigenemia was detected in 5 patients, p72 antigenemia in 3 patients, serum HCMV DNA in 9 patients, serum HCMV-specific IgM in 2 patients, and IgG in 19 patients. The sensitivity and specificity for diagnosis of active HCMV infection were 83.3% and 100%, respectively for pp65 antigenemia; 50% and 100% for p72 antigenemia; 100% and 80% for serum PCR; 33.3% and 100% for HCMV IgM serology; 50% and 100% for HCMV IgG serology. CONCLUSIONS: Compared with the control group, active HCMV infection is much more frequent in SLE children, and can occur before treatment with immunosuppressive agents, but most often occur after immunosuppressive therapy. In comparison with the other techniques used in this study, the pp65 antigenemia assay seems to be a better method for the early diagnosis and monitoring of active HCMV infection in children with SLE.

Adolescent↗

PubMed2001

[Differential diagnosis of pulmonary nodules by using enhanced CT with iodinated contrast material].

OBJECTIVE: To evaluate pulmonary nodules by using enhanced CT. METHODS: 89 patients with pulmonary nodules included 63 pulmonary carcinomas and 26 benign pulmonary nodules. Thin-slice CT was performed before injection, 35 s, 2 min and 5 min after injection of 100 ml of contrast material at 2 ml/s. The maximum level of enhancement and the enhanced patterns were recorded. RESULTS: Lung carcinomas enhanced significantly more than benign nodules. 27 lung carcinomas showed the sign of enhanced spots and twigs; 51 lung carcinomas and 4 benign nodules showed inhomogeneous enhancement; 3 lung carcinomas and 4 benign nodules had homogeneous enhancement; 5 tuberculomas and 1 inflammatory pseudotuma appeared ring enhancement; 12 tuberculomas showed nonenhancement. CONCLUSION: Enhanced CT is a valuable method to differentiate pulmonary carcinomas from benign pulmonary nodules.

Adult↗

PubMed2001

[Influence of HLA class I molecules expression on tumor cell resistance to NK lysis and the IFN-gamma regulatory effect].

OBJECTIVE: To investigate the relation between the NK lysis and HLA molecules expressed on the target cells as well as the regulatory effect of IFN-gamma. METHODS: The level of HLA-ABC molecules on seven human tumor cell lines were detected through the indirect immune fluorescence stain. NK lysis changes were observed after the blocking of HLA molecules on the target cells with the anti-HLA monoclonal antibodies or treating target cells with IFN-gamma. RESULTS: 1. Most of the tumor cell lines showed a complete or partial loss of HLA-ABC molecules, 2. After the HLA molecules had been marked on the target cells with the anti-HLA-ABC antibodies, the tumor cell susceptibility to the lysis of NK cells attack increased significantly and 3. After having being treated with IFN-gamma 500 U/ml for more than 48 hours, the HLA-ABC molecule levels on K562, M21 and PG cells went up. At the same time, their susceptibility to NK lysis was reduced. However, the resistance to Karpas, HL60 and HT29 NK lysis demonstrated a noticeable increase. The IFN-gamma promoted the apoptosis of HL60 and HT29 cells. CONCLUSION: The NK cells are capable of recognizing the HLA molecules on the target cells and show no lysis in providing a negative signal with the KIRs, an effect which the anti-HLA monoclonal antibodies are able to eliminate. IFN-gamma can be applied to make up for the loss of HLA molecules on some of the tumor cells, it can also facilitate some of the tumor cells' apoptosis.

Animals↗

PubMed2001

[The combined occluding effect of fluor protector and Nd:YAG laser irradiation on human dentinal tubules].

OBJECTIVE: To evaluate the combined occluding effect of fluor protector and Nd:YAG Laser irradiation on human dentinal tubules. METHODS: Twenty-four dentin specimens with exposed dentinal tubule orifices treated by 37% H3PO4 were randomly divided into four groups. Group B, C and D were vanished by fluor protector, group A served as a control. Group D was lased by Nd:YAG laser. Group C and D were brushed with normal force. RESULTS: Under SEM, group A showed numerous exposed dentinal tubule orifices, the diameter of which is 2-3 microns. Group B showed closure of dentinal tubule orifices. Group C showed that most of the fluor protector were brushed away and group D showed over 80% of the dentinal tubule orifices were occluded. CONCLUSIONS: Fluor protector combined with Nd:YAG laser can make most of the dentinal tubule orifices occluded even after brushed.

Combined Modality Therapy↗

PubMed2001

[Evaluation on the cytotoxicity of Gallium alloy by MTT-assay].

OBJECTIVE: To test the cytotoxicity of Gallium alloy, a new mercury-free dental restorative material. METHODS: L-929 mouse fibroblasts were used to detect the cell relative proliferation rate of Gallium alloy and high-copper amalgam by MTT-assay. RESULTS: The results indecated that the relative growth rate induced by Gallium alloy was high (93.0% +/- 4.9% 2ds, 102.0% +/- 3.5% 4ds, 107.2% +/- 4.2% 7ds), and the cytotoxicity of Gallium alloy was 0 grade according to the Test Standard of Shanghai Medical Biomaterial, meaning Gallium alloy had no significant cytotoxicity and the relative growth rate of Gallium alloy was higher than that of high-copper amalgam. The high-copper amalgam showed medium cytotoxicity. CONCLUSION: Gallium alloy has no significant cytotoxicity.

Alloys↗

PubMed2001

[Effect of Rheum palmatum decoction on increasing intelligence].

OBJECTIVE: To observe the nootropic effect of Rheum palmatum decoction in mice. METHOD: Step-down test. RESULTS: Rheum palmatum decoction could increase learning and memory ability of old mice and also improve the impairments of memory acquisition, memory consolidation and memory retrieval induced by scopalamine, NaNO2 and 40% EtOH respectively in mice. CONCLUSION: Rheum palmatum decoction contains the substances of increasing intelligence which may be substantial basis of the decoctions mainly containing Rheum palmatum theraping aphasia from apoplexy, senile dysmnesis, sequel from brain trauma, etc.

Animals↗

PubMed2001

Functional specialization of CK2 isoforms and characterization of isoform-specific binding partners.

In mammals, protein kinase CK2 has two isozymic forms of its catalytic subunit, designated CK2alpha and CK2alpha'. CK2alpha and CK2alpha' exhibit extensive similarity within their catalytic domains but have completely unrelated C-terminal sequences. To systematically examine the cellular functions of each CK2 isoform in mammalian cells, we have generated human osteosarcoma U2-OS cell lines with the expression of active or inactive versions of each CK2 isoform under the control of an inducible promoter. Examination of these cell lines provides evidence for functional specialization of CK2 isoforms at the cellular level in mammals with indications that CK2alpha' is involved in the control of proliferation and/or cell survival. To understand the molecular basis for functional differences between CK2alpha and CK2alpha', we have undertaken studies to identify proteins that interact specifically with each isoform of CK2 and could contribute to the regulation of their independent functions. A novel pleckstrin-homology domain containing protein, designated CK2-interacting protein 1 (i.e. CKIP-1) was isolated using the yeast two hybrid system as a protein that interacts with CK2alpha but not CK2alpha'. When expressed in cells as a fusion with green fluorescent protein, CKIP-1 localizes to the cell membrane and to the nucleus. In this study, we present evidence from deletion analysis of CKIP-1 suggesting that a C-terminal region containing a putative leucine zipper has a role in regulating its nuclear localization. Collectively, our data supports a model whereby CKIP-1 is a non-enzymatic regulator of CK2alpha that regulates the cellular functions of CK2alpha by targeting or anchoring CK2alpha to specific cellular localization or by functioning as an adapter to integrate CK2alpha-mediated signaling events with components of other signal transduction pathways.

Binding Sites↗

PubMed2001

[Preparation and characteristics of human adherent natural killer cells induced by rhIL-15].

OBJECTIVE: This work was to do preliminary study on the characteristics and preparation of rhIL-15 induced adherent human natural killer cells (A-NK). METHODS: Natural killer cells (NK cells) were first separated by centrifugation on Ficoll-Hypaque gradients, plastic adherence and nylon wool column adherence. Then, they were further purified by Percoll discontinuous density gradient centrifugation and T cell panning. Fluorescence-activated cell scan (FACScan) was applied to evaluate the natural killer cells and assess their degree of purification. Then, the purified NKs were incubated in the presence of rhIL-2 (6,000 U/ml) or rhIL-15 (6,000 U/ml) and changed into adherent NK cells. In the next step, the adherent kinetics, proliferation and cytotoxicity of A-NKs obtained by two different cytokines were analyzed by cell counting, MTT and reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: The adherent percentage, cytotoxity and proliferation of A-NKs generated in rhIL-15 culture were higher than those in rhIL-2. CONCLUSION: IL-15 is a better stimulator than IL-2 to induce adherent natural killer cells.

Cell Adhesion↗

PubMed2001

[DNA ploidy analysis and Ki-67 examination on renal neoplasms: investigation of degree of malignancy and biological behavior of small renal tumors].

OBJECTIVE: To investigate the degree of malignancy and the biological behavior of small renal tumors and provide a pathological basis for clinicians in determination of further treatment and prognosis. METHODS: Flow cytometry and immunohistochemical studies were performed on 48 small tumors with diameters less than 3 cm. and 39 renal cell carcinomas with diameters larger than 3 cm in comparison to assess their DNA ploidy status and Ki-67 PR (proliferation rate). RESULTS: Of the 48 small renal tumors, 6 adenoma were all diploid with low PR (< 1%). Aneuploid rate of 42 small renal tumors with clear and granular cell type was 16.7%, showing no statistical difference with the 33.3% aneuploid rate of 39 large renal cell carcinomas. 42 small renal tumors had a lower mean PR than large renal cell carcinoma. DNA ploidy correlated closely with nuclear grade, stage and histological type. There existed a close relation between PR and grade. CONCLUSION: Small renal tumors consist of both adenoma and carcinoma, therefore tumor size can not be used as a criterion in their differential diagnosis. DNA ploidy and Ki-67 PR are important indicators for predicting the biological behavior and prognosis of renal parenchymal tumors.

Adenocarcinoma, Clear Cell↗

PubMed2001

[Detection and analysis of SYT-SSX fusion gene in synovial sarcoma].

OBJECTIVE: To demonstrate that a characteristic SYT-SSX fusion gene resulting from chromosomal translocation t (X; 18) (p11; q11) was detectable in archival paraffin-embedded synovial sarcoma tissues. METHODS: SYT-SSX fusion transcripts in 20 synovial sarcomas (histologic subtypes, 15 monophasic and 5 biphasic) were detected and analyzed by the reverse-transcriptase polymerase chain reaction and compared with the results from relevant pathological data. RESULTS: A specific SYT-SSX RT-PCR product was found in 19 of 20 (95%) synovial sarcomas tested and of the 13 tumors containing SYT-SSX2, 10 were monophasic. CONCLUSION: SYT-SSX fusion transcripts are considered as a defining diagnostic marker of synovial sarcomas and the subtypes of SYT-SSX fusion transcripts (SYT-SSX1 and SYT-SSX2) may yield prognostic information.

Adolescent↗

PubMed2001

[Autologous dendritic cells eliciting cytotoxicity of bone marrow cells against chronic granulocytic leukemia].

OBJECTIVE: To investigate the activity of bone marrow cells activated by autologous dendritic cells (DC) to mediate cytotoxicity against chronic granulocytic leukemia (CGL) cells. METHODS: DC were separated from bone marrow mononuclear cells (BMMNC) of two CGL patients in hematological remission and harvested after 3 days of culture in IMDM containing autologous plasma, rhGM-CSF and rhTNFalpha at 37 degrees C, 5% CO(2) humidified atmosphere. BMMNC obtained from the patients were divided into 3 groups to set up Dexter systems: the control group, rhIL-2 containing, and the third group having DC added at day 4. After 10 days of culture, non-adherent cells were harvested and the changes of immunological phenotype and the percentage of P210 positive cells were analyzed. The cytotoxicity were assayed with two-colour flow cytometry. The non-adherent cells from all the 3 systems served as effector cells, those from control system as target cells. RESULTS: The cytotoxic activity against target cells was greater in the DC-activated effector cells than that in rhIL-2-activated ones. The percentages of death cells in target cells were 63.12% versus 42.59% (case 1) and 61.60% versus 21.46% (case 2), respectively. In addition, there was a marked increase in the death cell percentage in the DC-activated effector cells themselves after incubation with target cells. This phenomenon was not found in the rhIL-2-activated effector cells. The percentage of P210 positive cells was significantly lower in non-adherent cells after 10 days of culture in Dexter system, comparing with that in non-cultured BMMNC. The least P210 positive cells were found in those cultured with DC and the less in those with rhIL-2. CONCLUSION: Autologous DC were able to activate bone marrow cells to generate cytotoxicity against CGL cells. Their effect was greater than that of rhIL-2. These activated bone marrow cells might mediate graft versus leukemia effect in vivo.

Bone Marrow Cells↗

PubMed2001

[Alteration of immunological properties of bacterial lipopolysaccharide by calcium hydroxide treatment].

OBJECTIVE: To study alteration of immunological properties of LPS by Ca(OH)2 treatment, and to establish an experimental model in which ThP-1 cell line was cultured in vitro to observe the alteration of immunological properties of LPS. METHODS: ThP-1 cell line was used to establish a culture model in vitro. Amount of TNF-alpha released from stimulated cells acted as the index on immunological properties of the stimuli and alteration of immunological properties of LPS by Ca(OH)2 treatment. RESULTS: Within the range of observed LPS concentrations (10 micrograms/L-10 mg/L), the original immunological properties of LPS decreased significantly after treatment by Ca(OH)2 for a week (P < 0.001). When pH > or = 12.30, the amount of TNF-alpha excreted by monocyte did not differ significantly from the control group (P > 0.05). CONCLUSIONS: After treatment by Ca(OH)2 for a week, the original immunological properties of LPS decreased significantly. High pH value of Ca(OH)2 played a critical role during the alteration of immunological properties of LPS.

Calcium Hydroxide↗

PubMed2001

[Study of the changes and effect of VEGF and bFGF in early stage of maxillofacial blast injury in rabbits].

OBJECTIVE: The aim of this study is to determine the content of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in the wound fluid during maxillofacial soft tissue blast injury, and to evaluate their effects on angiogenesis of wound healing. METHODS: The rabbit model of maxillofacial blast injury was made by KTY-04 blasting cap. The content of VEGF and bFGF in wound fluid which was collected by using polying alcohol (PVA) sponge, were detected by ELISA. The distributions of VEGF and bFGF in the wound tissue were observed by using the techniques of in situ hybridization and immunohistochemistry. RESULTS: In the wound fluid of maxillofacial blast injury, the content of VEGF was rising steadily at the first week after injury. Comparing with natural sera, it showed difference from the first day after injury, and showed obvious different from the third day (P < 0.01), on which the content was 2.9 ng/ml +/- 2.7 ng/ml. It reached the peak on the seventh day after injury. The bFGF level in wound fluid was 565 pg/ml +/- 436 pg/ml, the peak value was gained at the sixth hour after injury. In the following days, it declined close to the serum level three to five days after injury, and then moved up slightly on the seventh day after injury. The expression of VEGF was located in epithelial cells, vascular endothelial cells and some chronic inflammatory cells. The mRNA transcription of bFGF was present in fibroblasts, endothelial cells and macrophages. CONCLUSION: VEGF and bFGF take part in two angiogenic cascades with synergistic action in maxillofacial blast injury. The bFGF stimulates the initial angiogenesis and induces the production of VEGF. The subsequent and more prolonged angiogenic stimuli can be mediated by VEGF.

Animals↗