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Biomedical subjects

M Zhang

Publications and source records attributed to M Zhang.

At least 649 records · Page 36Linked to original sources
PubMed1998

Telomerase Activation in Malignant Bone Tumors.

Background: Telomerase is a ribonucleoprotein that can reconstitute the ends (telomeres) of chromosomes after cell division and thus circumvent the cumulative damage that occurs during mitotic cycles of cells. A unique association has been established between telomerase activity and neoplastic transformation and cellular immortalization. The measurement of telomerase activity has also been considered to be a diagnostic marker for human malignant tumors; however, little is known about the status of telomerase activity in malignant bone tumors. Methods and Results: Thirty-five human bone sarcomas and adjacent noncancerous tissues were subjected for the first time by the modified telomeric repeat amplification protocol (TRAP)-silver staining assay for telomerase activity. The results showed that telomerase activity was present in 82.9% (29/35) of malignant bone tumors. Twenty-two of 26 (84.6%) osteosarcomas, 3 of 5 (60%) chondrosarcomas, 2 of 2 (100%) malignant fibrous histiocytomas, and 2 of 2 (100%) rhabdomyosarcomas contained telomerase activity. In contrast, there was no telomerase activity in 19 adjacent noncancerous tissues. Conclusions: The findings suggest that telomerase might play an important role in the development of malignant bone tumors. The detection of telomerase in malignant bone tumors may have value in increasing the accuracy of diagnosis of malignant bone tumors.

Journal Article↗
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

[A prospective study on post-transfusion hepatitis G virus infection].

OBJECTIVE: To study the incidence of post-transfusion hepatitis G virus (HGV) infection in our country and the relationship between it and post-transfusion hepatitis B (HB) and C (HC). METHODS: Hepatitis B surface antigen, hepatitis Be antigen, antibodies against HBsAg, HB core antigen HBe and HC virus, HCV RNA and HGV RNA were detected for 138 patients with blood transfusion before and after ther surgical operations. RESULTS: There occurred 53 cases of post-transfusion hepatitis virus infection, 48 with HCV infection and two with HBV infection (including one of super-infection with HBV and HCV). HGV infection could be found with nested reverse transcription polymerase chain reaction in seven cases, three of them co-infected with HCV all with elevated activity of serum alanine transaminase (ALT). But, ALT was kept normal in the patients with simple HGV infection. HGV RNA could be detected for one month to half a year. Residual donor's blood for five of the seven patients with post-transfusion HGV infection was available for examination, and HGV RNA was detected positive in at least one of the donor's blood for 3 cases. CONCLUSION: No clinical manifestation with viral hepatitis and no elevation in activity of serum ALT were found in blood donors and blood transfusion patients with infection of simple HGV, which did not conform to the view that HGV was an important hepatitis virus.

Adolescent↗
PubMed1998

Radioimmunoassay of human cardiac acidic isoferritin: a new index for hepatic cancer.

OBJECTIVE: To investigate human cardiac acidic isoferritin as a specific index of hepatic cancer. METHODS: Acidic isoferritin was isolated and purified from human heart muscle. A radioimmunoassay for the acidic isoferritin in human serum has been developed, on the equilibrium method. The antiserum was obtained from rabbits immunized with purified acidic isoferritin. The 125I-acidic isoferritin was prepared by the chloramine-T method. The data were processed using the automated smoothed spline function data processing program. RESULTS: The intra- and inter-assay CV of acidic isoferritin RIA were 1.65% and 9.71%, respectively, and the recovery rate was 102%. The antiserum provided a linear response from 7.0 to 369.6 micrograms/L with ED50 of 27.50 micrograms/L. The cross reactivity with AFP, CEA, lactoferrin and transferrin was negligible, and that with ferritin was 1.74%. The serum acidic isoferritin concentration showed a considerable variation in different sex and age groups. The serum acidic isoferritin was measured in liver diseases including hepatic cancer, hepatic cirrhosis and acute and chronic hepatitis. Its sensitivity for diagnosis of hepatic cancer was 73.05%, independent from the severity of hepatic injury. In 8 malignant tumors studied, acidic isoferritin appeared the most valuable in the diagnosis of hepatic cancer, with its positive, negative, false positive and false negative rates all being ideal. CONCLUSIONS: Acidic isoferritin may turn to be a rather specific index of hepatic cancer. Combination of monitoring both acidic isoferritin and AFP would raise the positive detection and specificity in the diagnosis of hepatic cancer.

Biomarkers, Tumor↗
PubMed1998

[Three dimensional observation on revascularization and study on bone metabolism of allogenic transplanted mandible].

In order to observe stereological correlation between new vessels and surrounding tissue, 6 rabbits were used for the following experiments. The mandible defect model was made by cutting 1 cm x 0.5 cm bone from both right and left side of mandible. Then, the left defect was repaired by the bone segment from the right side, and the right defect was repaired by frozen allogenic bone segment. One month later, the metabolism of the bone segments was observed by nuclein scintiphotography. The revascularization of the bone segments was observed by vascular corrosion cast method. It was shown that new vessels from host soft tissue could penetrate the periosteum of allogenic transplanted bone, along the absorbing path, ingrowth into the bone. The metabolism of the bone was active. It was suggested that the vessel growth from host to the graft is one of the main patterns of revascularization.

Animals↗
PubMed1998

[Distribution of Mg2+ and Ca2+ in serum and lymphocyte of the patients with arrhythmia].

The distributions of Mg2+ and Ca2+ in serum and lymphocyte from 51 arrhythmic patients (15 cases of atrial premature beat, 12 cases of atrial fibrillation, 24 cases of ventricular premature beat) and 30 healthy subjects were detected by flame atomic absorption spectrophotometry. The results showed that the distribution of Mg2+ of the arrhythmia cases was significantly lower than that of the control group (P < 0.01) and the concentration of Ca2+ in lymphocytes of arrhythmia case group was significantly higher than that of the control group (P < 0.01). The above distribution of Mg2+ and Ca2+ was somewhat related to the degree of heart failure. It is suggested that the lower distribution of Mg2+ in lymphocytes may cause arrhythmias.

Arrhythmias, Cardiac↗
PubMed1998

[Study of a new type of material substituted for human hard tissues-hydroxyl poly calcium sodium phosphate: histologic report implants in mandible of animals].

This study was aimed to evaluate the histocompatibility of hydroxyl poly calcium sodium phosphate (HPPA) preliminarily. HPPA and hydroxylapatite were implanted in the mandibular defect in dogs. The implant-bone interface was observed by using stereomicroscope and decalcified histologic sections. The result demonstrates that HPPA has well-osseous integrated property after being implanted into bone tissues. This suggests that HPPA might be a new material of future excellence in substitution for human hard tissues.

Animals↗
PubMed1998

[The comparison of radiosensitivity between uterine cervical squamous carcinoma and adenocarcinoma].

OBJECTIVE: To compare the radiosensitivity of uterine cervical squamous carcinoma and adenocarcinoma. METHODS: The shrinkage of tumor and the radiation-induced damage were compared between cervical squamous carcinoma and adenocarcinoma after twice afterloading radiotherapy. Proliferating cell nuclear antigen index (PI), detected immunohistochemically, was compared before and after radiotherapy between the two tumors. RESULTS: Patients of squamous carcinoma with tumor shrinkage 50% or more accounted for 70% (21/30) and patients of adenocarcinoma accounted for 27% (4/15), which was statistically significant (P < 0.01). The radiation-induced damage grade II b-III accounted for 60% (18/30) in squamous carcinoma and for 20% (3/15) in adenocarcinoma, which was statistically significant (P < 0.05); PI decreased from 53.50% +/- 4.34% to 39.30% +/- 4.02% after radiotherapy in squamous carcinoma (P < 0.001), while PI decreased from 35.47% +/- 3.83% to 31.80% +/- 3.06% in adenocarcinoma (P > 0.05). CONCLUSIONS: The radiosensitivity of cervical squamous carcinoma is higher than that of adenocarcinoma. The decrease of PI after radiotherapy may be a biological basis of radiosensitivity for uterine cervical squamous carcinoma.

Adenocarcinoma↗
PubMed1998

[Effect on endothelin and cytokines on the pathogenesis of coronary heart disease].

The plasma levels of endothelin(ET), serum levels of tumor necrosis factor(TNF) and interleukin-6(IL-6) in 35 patients with coronary heart disease(CHD) and 20 healthy people were studied by radioimmunoassay and enzymebinded immunosorbent assay(ELISA). The results showed that the plasma ET level and the serum TNF level in the CHD group, especially the acute myocardial infarction(AMI) group, were much higher than those of the control group (P < 0.01). There was no obvious statistical difference on IL-6 levels between the narrowed coronary artery group and the control group (P > 0.05). But the serum level of IL-6 in the AMI group was significantly higher than that of the other groups (P < 0.01). These findings indicate that ET and cytokine levels may play an important role on the pathogenesis of coronary heart disease.

Adult↗
PubMed1998

[Comparative studies of the pharmacokinetics of 131I-3H11 after different routes of administration].

OBJECTIVE: To study the pharmacokinetics of 131I-3H11, a mAb to gastric cancer, by different routes of administration. METHODS: Three groups of rabbits were injected with 131I-3H11 through ear vein(i.v.), portal vein(pv) and into the peritoneal cavity(i.p.), respectively. At various time intervals, blood samples from the ear vein and portal vein, and the peritoneal fluid were collected and their radioactivities determined. RESULTS: (1) The radioactivity of ear vein blood and portal vein blood was the same in the i.v. group. In the peritoneal cavity, it was 1/3 of that in the blood. (2) In pv group, radioactivity of the portal vein blood was higher than that of the ear vein blood, but the difference became insignificant 30 min later. In the peritoneal cavity, it was 1/3 of that in the blood. (3) In i.p. group, radioactivity in the peritoneal cavity was highest, its peak activity was 37.2-fold and 5.4-fold as high as that of the venous blood, respectively. That in the portal vein blood was 6.9 times higher than in the ear vein blood. CONCLUSION: There is a significant pharmacokinetic advantage for i.p. over i.v. and pv routes of administration for the prevention and treatment of peritoneal recurrence and liver metastsis of gastrointestinal cancers after surgical resection.

Animals↗
PubMed1998

[Community investigation of the activities of daily living (ADL) and medical conditions of the elderly in Shanghai].

OBJECTIVE: To study the ADL status and prevalence of medical conditions in aged population in Shanghai, and to analyze the impact of dementia syndrome and other illnesses to ADL performance. METHODS: Both the Chinese version of ADL scale (five items) and the list of self-reported illnesses questionnaire (32 conditions) were used in the survey. After screening and case-identification, 3745 noninstitutionalized aged residents, who were 65 years and older, were included in the analysis sample. A separate multiple logistic regression model was used in both groups (65-74 years and over-75), observing the effect of age, gender, education and medical conditions (as control variables) on ADL dependence. RESULTS: The prevalence rate of functional dependence in ADL was 8.28%, and the prevalence curve was doubled steeply along with each ten years. The most prevalent medical conditions (> 20%) were hypertention, heart disease, cataract/glaucoma and artheritis/rheumatism, whereas, dementing disorder was 4.61%. Of all illnesses, stroke, Parkinson's disease, dementia, diabetes and emphysema were the most important predictors of ADL dependence in both aged groups. In the group more than 75 years old, cancer, arteriosclerosis and hypertension seemed to be strongly related to ADL dependence, dementia syndrome was one of the remarkable risk factors. CONCLUSION: Dementing disorders such as Alzheimer's disease may lead to severe disturbance of ADL performance in the aged, therefore, the community rehabilitative measures and health care services should be stressed by the society to improve the quality of life of the elderly.

Activities of Daily Living↗
PubMed1998

[Auditory P300 in assessing cognitive dysfunctions of Alzheimer's disease and schizophrenia].

OBJECTIVE: To investigate the value of auditory P300 in assessing cognitive dysfunctions of aged patients with Alzheimer's disease(AD) or schizophrenia. METHODS: An'oddball' paradigm was used to elicit the auditory P300 from 39 patients diagnosed as having Alzheimer's disease according to DSM-III-R, 34 aged schizophrenics and 40 normally age-matched subjects, by using a Dantec Concerto SEEG-16 instrument. RESULTS: The variability of P300 waveform increased in AD patients, who presented reduced N1 latency elicited by frequent stimuli. The P3 amplitude of the AD patients was lowered by 14% compared with that of schizophrenics, and by 60% than compared with that of normal controls. Compared with the normal controls, schizophrenics presented reduced N1, P2, N2 and P3 latencies, and their P3 amplitude was decreased by 54%. CONCLUSION: The auditory P300 is of value in assessing the cognitive dysfunctions of AD patients and aged schizophrenics.

Aged↗
PubMed1998

[Brain evoked potentials in patients with Alzheimer's disease and schizophrenia: a comparative study].

OBJECTIVE: To investigate the differences of visual evoked potentials(VEP) and auditory evoked potentials(AEP) between patients with Alzheimer's disease and schizophrenics. METHODS: Both VEP and AEP were elicited from 39 patients with Alzheimer's disease, 34 aged schizophrenics and 40 normally age-matched subjects. RESULTS: The variability of waveforms of both VEP and AEP became increased within the AD group. The AD patients presented significantly delayed latencies (N2 and P3 of VEP; P1, N1, P2, N2 and P3 of AEP) as compared to the normal controls. The P2 amplitude of VEP of AD patients was 32% lower than that of schizophrenics and 57% lower than that of the controls. The P2 amplitude of AEP of AD patients was 36% lower than that of schizophrenics and 70% lower than that of the controls. Compared with the normal controls, the schizophrenics showed reduced VEP-P2 latency, prolonged N2 and P3 latencies of both VEP and AEP. The P2 amplitudes of VEP and AEP of schizophrenics were decreased by 16% and 20% respectively as compared to the normal controls. CONCLUSION: The variations of VEP and AEP are a referential tool for diagnosing Alzheimer's disease and schizophrenia.

Aged↗
PubMed1998

[Vascular endothelial growth gene therapy for narrowing of rabbit iliac artery].

OBJECTIVE: To study the mechanism of renarrowing and vascular endothelial growth factor (VEGF) gene therapy to prevent the restenosis caused by balloon angioplasty. METHODS: According to the special function of VEGF that promepts the proliferation of endothelial cell (EC), we constituted an eukaryotic expression vector of pcDNA3/VEGF, and added the pcDNA3/VEGF to the surface of polylysine-balloon. We examined the results of the test by in situ blot, eletromagnetic blood flow mechine, scanning eletromicroscope, and light microscope. RESULTS: There was higher expression of VEGF mRNA and iliac artery intima in the VEGF gene group. The extent of endothelialization was larger, the ratio of intima to media (I/M) was smaller, and the blood flow was more sufficient than in the vector control group. CONCLUSION: VEGF gene local delivery could stimulate the proliferation of EC, accelerate the endothelialization of injury-artery, and inhibite the proliferation of smooth muscle cell (SMC).

Angioplasty, Balloon↗