Biomedical subjects
Publications and source records attributed to Qing Zhang.
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Explore the source record for details and available documents.
Glial cell line-derived neurotrophic factor (GDNF) has received much attention as potential therapeutic agent for the treatment of neurodegenerative diseases. It will be very important to discover the molecular mechanism of this factor and its specific GFRalpha co-receptor. Based on the principle of molecular evolution that site-specific functional importance is relevant to the pressure it undergoes under natural selection, evolutionary trace method was used to identify the functional epitopes in GDNF and GFRalpha families. Some trace residues had been proved to be important in ligand-receptor binding, especially in rat GFRalpha1, where alanine scanning mutagenesis confirmed that sites N(152)N(153), R(259), S(316)N(317)S(318) and Q(247)D(248)S(249) were critical for GFRalpha1 binding to GDNF or Ret and thus affected the formation of GDNF-GFRalpha1-Ret complex.
OBJECTIVE: To investigate the material foundation of the fusion of bcr and abl genes, and to explore the pathogenesis of chronic myeloid leukemia. METHODS: By FISH combined with laser confocal scanning microscopy, the three-dimension (3D) distribution of bcr and abl genes in the interphase nuclei of normal and irradiated IM-9 cells was studied in each cell cycle phases. RESULTS: abl and bcr genes distributed non-randomly in the interphase nuclei of IM-9 cells. abl gene preferably located at the outer layer and bcr near the core of the nucleus. The two genes were drawn near each other most in G(0) phase. The relative distance between the homologous genes was greater at proliferation phase than at quiescence phase. After irradiation, the relative distances from the two genes to the core and between the two genes were shortened, with the shortest distance between the two genes in S phase. CONCLUSION: Irradiation could change the 3D-distribution of abl and bcr genes in the interphase nuclei of IM-9 cell and accelerate them to draw near each other.
OBJECTIVE: To evaluate the prescription of antipyretic analgesic and anti-inflammatory drugs by the medical staff of Nanfang Hospital. METHODS: Drug utilization index (DUI) was used to analyze the prescriptions of antipyretic analgesic and anti-inflammatory drugs to out-patients in the fourth quarter of 2001. RESULTS AND CONCLUSION: In 71.4% of the prescriptions, the DUI ranged from 0.9 to 1.1, indicating basically justified utilization of antipyretic analgesic and anti-inflammatory drugs in Nanfang Hospital though with occasional abuses of somiton tablets. We urge more careful application of these drugs and their compound preparations, especially in infant patients.
With the development of the technology in medical informatics area, Health Level Seven (HL7) Standard for electronic data exchange in all healthcare environments has become a widely used standard. To bring it into practice in China, we developed an HL7 gateway. The gateway is used to connect two different medical information systems, a Hospital Information System (HIS) and a Laboratory Information Management System (LIMS), via the HL7 message exchanging. The system verified the feasibility of HL7 standard and made a good example for further research and development.
OBJECTIVE: To improve the life quality of cancer patients with metastasis to long bone and to select suitable surgical treatment. METHODS: Fifty two patients with metastasis 27 men and 25 women, were treated from 1990 to 1999. Their average age was 56.8 years (33 - 74). In 16 patients with multiple lesions, underwent surgery at bone shaft (29 patients) and bone epiphysis (26). Thirty patients were treated for pathologic fracture and the rest for impending fracture. Operations included limb-salvage (51 patients) and amputation (4) Limb salvage consisted of intralesional curettage (3 patients), intramedullary nailing reconstruction (29), endoprosthesis (18), and temporary spacer (1). 21 patients accepted postoperative chemotherapy or radiotherapy. RESULTS: Follow-up of 52 patients for a mean of 28.2 months (2 - 122 months) showed pain relief (41 patients), (75%) and full or part weight-bearing stability (36) 69%. Local tumor recurrence occurred in 11 patients. CONCLUSIONS: Surgical treatment can effectively improve the life quality of patients with metastasis to long bone. The metastatic lesions should be resected with wide or radical margin for the patients with kidney, breast, prostate and thyroid cancer.
OBJECTIVE: To investigate the prevalence of sleep apnea-hypopnea syndrome (SAHS) among adults aged over 30 yr in Chengde city of Hebei province. METHODS: 1 168 subjects (over 30 yr) were derived from a random sample of the population among the Shuangqiao district in Chengde city. All subjects were asked at home to answer questions about their snoring, daytime sleepiness, and habits of smoking and drinking. According to the degree of snoring, 127 moderate and severe snorers were measured by portable PSG for a whole night and the prevalence of SAHS was estimated according to AHI and ESS scores. RESULTS: 1 168 subjects (95.42%) answered the questions. The prevalence of snoring was 53.76%. The prevalence of moderate and severe snoring (>or= second degree) was 28.25%. The prevalence of snoring increased with age before the age of 70. The prevalence of snoring in males was significantly higher than that in females. Smoking and drinking groups were associated with a higher prevalence of snoring. The prevalence of snoring was higher in drivers (42.00%) than that in other populations. The estimated prevalence of SAHS according to both the AHI > 5 and the ESS >or= 9 was 4.63%. CONCLUSIONS: The estimated prevalence of SAHS among adults aged over 30 yr in Chengde city was 4.63%. It means that SAHS needs better understanding and more study.
OBJECTIVE: To study the concentration of stresses at the cervix with simulating restoration of tooth defects. METHODS: A two-dimensional finite element model of a mandible first premolar with defect from longitudinal section was developed. The model was simulatedly restored, respectively by composite resin and glass ionomer cement, and then investigated stress variation in the cervical area. RESULTS: In the restored models, both of materials improved the concentration of stresses at the cervical area. The composite resin and the glass ionomer cement restorations made the maximum principal stresses declined respectively to 36.2 MPa and 42.5 MPa, which were close to the value of normal tooth in the deepest area of defects. CONCLUSION: The concentration of stresses are improved in the cervical area with teeth defects restored.
OBJECTIVE: To analyze the prognostic factors in patients with refractory acute myeloid leukemia, so as to provide theoretical basis for choosing an appropriate chemotherapy. METHODS: This study included 48 patients with refractory acute myeloid leukemia who received two standard DA regimens followed by chemotherapy with median dose of Ara-C and mitoxantrone. The factors such as age, gender, responses to the standard chemotherapy, cytogenetic abnormalities, blast cell counts in the bone marrow, peripheral blood cell counts, extramedullary infiltration exhibition and LDH were examined in light of their respective impact on the patients' survival. Cox regression model was used to analyze the prognostic factors. RESULTS: The results revealed that the factors such as achievement of the first complete remission after standard induction chemotherapy, the remission duration longer than 6 months, favorable cytogenetic abnormalities, blast cell counts less than 50% in bone marrow, absence of severe anemia, absence of liver or pancreatic enlargement or central nerves system (CNS) leukemia, and LDH less than 360 U/L, all indicated favorable prognosis of the patients. Age, gender, white cell counts in periphery blood or lymphadenopathy were not related to the survival of the patients. CONCLUSION: The patients with favorable prognostic factors should receive intensive chemotherapy for prolonged survival; allogeneic bone marrow transplantation should be performed as soon as possible in patients with unfavorable prognostic factors.
OBJECTIVE: To establish a mouse model of acute hematopoietic failure and explore the pathological basis of platelet changes in bone marrow suppression. METHODS: An initial large dose of cyclophosphamide (200 mg/kg) was injected through the tail veins of the mice, follow by daily intraperitoneal injection starting on the next day for 7 d. The number and morphology of the cells in the peripheral blood and bone marrow were observed by means of cell counting and smear, respectively, with the platelet aggregation determined using ADP. The coagulation time was measure by turbidimetry. RESULTS: The amount of platelets, erythrocytes, leukocytes and the nucleated cells in mice bone marrow was significantly lowered in the mouse models in comparison with the control mice, and the normal hematopoietic tissues were depressed. The blood platelets in the models were lowered by 49%, an amplitude of declination significantly greater than that occurring in the erythrocytes and leukocytes (by 28% and 25% respectively). Though the mean platelet volume and percent platelet aggregation underwent no obvious changes, the coagulation time was significantly shortened. CONCLUSION: The methods we described for establishing mouse models of hematopoietic failure induced by cyclophosphamide is rapid and highly efficient, and may facilitate ready preparation of mouse models of thrombocytopenia which respond strongly to cyclophosphamide without blood platelets function impairment.
OBJECTIVE: To investigate the changes of sugar chain structures of alkaline phosphatase (ALP) in hepatoma tissue and its relation to the invasiveness of hepatocellular carcinoma (HCC). METHODS: The binding ratios of ALP from 9 normal liver tissues, 16 hepatoma tissues and 16 noncancerous tissues surrounding hepatoma were analysed by affinity chromatography on various lectin columns including leukoagglutinating phytohemagglutinin (L-PHA), lentil lectin (LCA), Datura stramonium agglutinin (DSA), erythroagglutinating phytohemagglutinin (E-PHA) and Sambucus nigra bark agglutinin (SNA). RESULTS: The binding ratios of ALP on L-PHA (22.94%+/-5.30%), DSA (55.97%+/-13.72%), LCA (38.16%+/-8.87%), E-PHA (11.56%+/-4.81%) and SNA (69.80%+/-13.71%) in HCC tissues were significantly increased (P<0.01) compared with that in normal liver tissues (L-PHA 5.89%+/-2.75%, DSA 36.20%+/-11.58%, LCA 17.90%+/-6.71%, E-PHA 5.38%+/-2.20%, SNA 57.32%+/-11.27%), respectively. t values between the two groups were 8.94, 3.64, 5.94, 3.62 and 2.32, respectively. L-PHA-binding ratio (25.84%+/-4.67%) of ALP in HCC with invasiveness was significantly higher than that (18.10%+/-3.64%) without invasiveness (t=3.71, P<0.01). CONCLUSION: The changes of ALP sugar chain structures occur in HCC tissue. b1-6 branching sugar chain structure of ALP is related to the invasiveness of HCC.
OBJECTIVE: To investigate the way of diagnosis and therapy of parosteal osteosarcoma. METHODS: A retrospective review was conducted of 48 patients treated at our department between June 1964 and December 2001. The average age of patients in this study was 29.2 years (13 - 47 years). Thirty-two of the patients were female; sixteen were male. The single most common site is the posterior aspect of the distal femur (in 36 patients), followed by the femur shaft (in 6 patients), the proximal tibia (in 2 patients), etc. Nine patients had been operated on before referral to our department. RESULTS: The average follow-up period from the first operation was 5.2 (0.25 - 24) years. In 36 of the 39 patients in whom a limb-salvage procedure was performed, a segment of the tumor-bearing bone was excised along with the tumor, whereas in 3 patients only the subadjacent cortex was excised with the tumor. In the limb-sparing group, the reconstruction was achieved by means of attenuated tumor bone or allograft in 23 cases, by endoprosthetic replacement in 9 cases, and by allograft replacement in 4 cases. The local resections were wide in 35 cases, and marginal in 13 cases. After marginal surgery, local recurrence occurred in 5/13 patients, whereas it occurred in 3/35 patients treated with wide resection. Pulmonary metastases developed in 6 patients, four patients died, and 2 patients are alive with disease. There were 4 cases of fractures of bone grafts. Four patients developed an infection. Long-term survival rate is 85.8%. For tumors that invaded the medullary canal there was no statistical association with local recurrence or metastasis. There is statistical significance between surgical margin and local recurrence. CONCLUSIONS: Wide surgical excision alone is adequate treatment for patients with conventional parosteal osteosarcoma. A tumor-free margin remains the critical factor determining overall prognosis. When a marginal excision was knowingly done to preserve a major neurovascular bundle, the risk of recurrence was less than when it was done to shell-out a presumptively benign lesion. Repeated recurrence probably increases the risk of dedifferentiation and thereby worsens the prognosis. Recurrent lesions with multiple soft-tissue satellite nodules or involvement of the neurovascular structures may however require amputation to provide sufficient local control when a wide margin cannot be achieved. An individualized resection will be performed in the future probably under the help of the advanced technique of image to distinguish the reactive zone from the normal tissue precisely.
OBJECTIVE: To investigate the epidemiological characteristus of human caliciviruses (HuCVs) among children under 5 years of age with acute diarrhea and to estimate the disease burden in Lulong county. METHODS: HuCVs were detected by enzyme linked immunosorbent assay (ELISA) and reverse transcription-polymerase chain reaction (RT-PCR). Some PCR amplicons were cloned and sequenced. Phylogenetic tree was constructed for strain characterization. The rate of HuCVs-attributed hospitalization was estimated according to the positive rate of HuCVs detection in fecal specimens collected from hospitalized diarrhea patients. RESULTS: Between July 1999 and June 2001, 708 fecal specimens were collected, of which 393 rotavirus-negative and 5 rotavirus-positive specimens were detected for HuCVs. Thirty-one point six percentage of fecal specimens from patients with diarrhea was HuCVs positive. Among inpatients, HuCVs positive rate was 17.5%. HuCVs detection was mainly distributed in 3 - 17 mouth-old children, in winter. All 11 strains belonged to NLV GII in which 6 strains GII-3, 2 strains GII-4 and 3 strains GII-7, and they shared 55.1% - 100% nucleotide identity. NLV GII-4 and GII-7 were identified in 2000, while NLV GII-3 and GII-7 in 2001. The preliminary estimate of HuCVs-attributed hospitalization rate was 3.6 per thousand. CONCLUSION: Human caliciviruses with different genotypes circulated among children in Lulong county with GII NLVs were the prevalent strains. The disease burden of HuCVs was second to rotavirus.
OBJECTIVE: To study the mucociliary transport function of rhinitis sicca and atrophic rhinitis, and to explore the standard of diagnosis. METHOD: The MTR of normal control group, the rhinitis sicca group and the atrophic rhinitis were determined by using saccharin, and then compared. Then MTR of rhinitis sicca treatment group were compared before and after treatment. RESULT: The MTR of normal group: (9.15 +/- 0.86) mm/min; the rhinitis sicca group: (5.84 +/- 0.48) mm/min and the atrophic rhinitis group: (3.36 +/- 0.07) mm/min. There were significant difference among them (P < 0.05). 25 patients of rhinitis sicca were treated by administering the pill of Gelomyrtol forte in 2 weeks. The MTR of rhinitis sicca were no significant difference before and after treatment (P > 0.05). CONCLUSION: Rhinitis sicca is a separate nasal disease, which is different from atrophic rhinitis. It is important to find an effective treatment for the disease.
OBJECTIVE: To review the progress in the study of chemical ingrediens, pharmacological effects and clinical application of Allium macrostemon Bunge. METHOD: Documents of experimental and clinical study on A. macrostemon in recent 10 years were consulted and summarized. RESULT: A. macrostemon had many active ingredients, pharmacology effects and wild clinical application. CONCLUSION: The results provide a rational foundation for the further development and utilization of A. macrostemon.
OBJECTIVE: To investigate the impact of HDL on oxLDL-induced apoptosis of endothelial cells and relevant mechanisms. METHODS: Human umbilical venous endothelial cells (ECV-304) were exposed to oxLDL or oxLDL + HDL. The apoptosis of the endothelial cells was checked by the Flow cytometry and DNA electrophoresis, while caspase-3 activity was meaured simultaneously. RESULTS: The apoptosis rates induced by 100 microg/ml and 200 microg/ml of oxLDL were 28.40 + 5.30% and 34.7 +/- 4.64%, with caspase-3 activity of 166. 01 +/- 16.44 and 263.74 +/- 46.62 pmol/(min x mg pro), respectively. The DNA electrophoresis showed typical ladders. With exposure to HDL (200 mixrog/ml), the above apoptosis rates dropped to 8.06 +/- 2.35% and 9.40 +/- 2.58% respectively. There were no apoptotic ladders while the caspase-3 activities were significantly reduced (67.73 +/- 14.83 and 111.26 +/- 27.13 pmol/(min x mg pro). CONCLUSIONS: HDL can significantly reduce the apoptosis of cultured endothelial cells induced by oxLDL. This effect may be mediated via suppression of caspase-3 activity.
OBJECTIVE: The aim of the present study was to investigate the association between a polymorphism of the aldosterone synthase gene CYP11B2 and left ventricular structure and function in Chinese Han people. METHODS: One handred and ten persons aged 20 to 49 years were studies by echocardiography to assess left ventricular size, mass and function. The subjects were genotyped with the use of PCR-RFLP. RESULTS: Three genotypes for aldosterone synthase at position -334 in the transcriptional regulatory region were found: TT, TC and CC. The distribution of sex and arterial blood pressure was homogeneous in the aldosterone synthase genotype groups. No significant associations of echocardiographic LV dimensions, mass and function with a specific aldosterone synthase genotype were noted. CONCLUSION: The above data are not in favor of a significant association between the polymorphisms of aldosterone synthase gene CYP11B2 and the LV structure and function in Chinese normal Han people.