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Biomedical subjects

W Zhang

Publications and source records attributed to W Zhang.

At least 667 records · Page 37Linked to original sources
PubMed1999

[Changes of serum biochemical parameters during hypothermia and hypoxia in rats].

OBJECTIVE: To study the effects of hypothermia and hypoxia on serum biochemical parameters. Method Acute hypobaric hypoxia experiment in cold environment was carried out in 48 healthy Wistar rats to observe changes of hepatic, cardiac and renal functions. RESULT: Hepatic, cardiac and renal functions changed non-prominently after acute hypoxia exposure under cold condition. Under hypoxic exposure of the same degree, serum lactic dehydrogenase(LDH), alanine transaminase(ALT), blood urea nitrogen (BUN) and creatinine (Cr) increased more significantly at 10 degrees C than those at 20 degrees C (P < 0.01) while creatine kinase (CK) decreased significantly at 10 degrees C than that at 20 degrees C. CONCLUSION: After acute hypoxia in cold environment, the changes in cardiac function did not simply equal to the changes by cold environment plus changes by acute hypoxia.

Alanine Transaminase↗
PubMed1999

Effects of Curcuma Longa on proliferation of cultured bovine smooth muscle cells and on expression of low density lipoprotein receptor in cells.

OBJECTIVE: To investigate the inhibitory effects of aqueous turmeric extract (AqT) and serum of rats orally treated with ethanol extract of turmeric (SeT) on proliferation of vascular smooth muscle cells (VSMC) and its effects on the expression of low density lipoprotein receptor (LDL-R) antigen on the surface of smooth muscle cells. METHODS: Enzyme-linked immunosorbent assay (ELISA) for the expression of LDL-R protein and thiazolyl blue (MTT) assay for the proliferation of VSMC were used in this study. RESULTS: Both aqueous turmeric extract (AqT) and serum of rats orally treated with ethanol extract of turmeric (SeT) could inhibit 10% serum activated proliferation of VSMC. The inhibition shown in both experiments was dose-dependent with an inhibitory rate of 18.9% at 20 mg/ml AqT and rate of 20.1% at 10% SeT respectively. AqT up-regulated the expression of LDL-R protein with a highest rate at 5 mg/ml AqT in 3% lipoprotein deficient serum (LPDS). SeT did not show significant effect on the expression of LDL-R on the surface of VSMC. CONCLUSION: The extracts of turmeric may be extended to decrease the risk of atherosclerosis (AS).

Animals↗
PubMed1999

Mifepristone in treating ectopic pregnancy.

OBJECTIVE: To explore the effect of mifepristone in treating ectopic pregnancy. METHODS: Thirty-eight patients with ectopic pregnancy and without tubal rupture or tubal abortion, aged between 23 and 46 years, were studied. The stage of amenorrhoea ranged from 34 to 51 days. The patients took mifepristone at a dosage 2 times anti-early pregnancy dosage. The symptoms, and serum human chorionic gonadotropin (beta-hCG) levels were monitored, and ultrasonic examination performed at regular intervals. RESULTS: Thirty-seven of 38 patients were cured, the success rate being 97.4%. CONCLUSION: Mifepristone is safe and effective to treat ectopic pregnancy.

Abortifacient Agents, Steroidal↗
PubMed1999

[The endocytic routes of exogenous antigen in murine dendritic cells and macrophages].

OBJECTIVE: To compare the endocytic routes of exogenous antigen in murine dendritic cells (DC) and macrophages. METHODS: Murine bone marrow-derived DC and peritoneal macrophages were pulsed with HRP-5 nm colloidal gold for 10 minutes and chased for 0-120 minutes in culture medium. Intracellular distribution of 5 nm colloidal gold was explored by means of cellular enzymatic-chemistry of acidic phosphatase and MHC II cellular immunochemistry under electron microscope. RESULTS: After 10 minutes pulse with HRP-5 nm colloidal gold and then 30 minutes of chase, most of HRP-5 nm colloidal gold internalized by DC entered into MHC II positive MIICs, but a little entered into acidic phosphatase-positive lysosomes. In contrast to DC, most of lysosomes of macrophages were accessed by HRP-5 nm colloidal gold, and a small portion of HRP-5 nm colloidal gold entered into MIICs. After 60 minutes of chase, 5 nm colloidal gold could hardly be seen within macrophages, whereas most of 5 nm colloidal gold retained in DC. CONCLUSION: The endocytic route of exogenous antigen in DC apparently differs from that in macrophages. Most of antigens taken by macrophages enter into lysosomes within 30 minutes. In the case of DC, most of internalized antigens enter into MIICs, which may be related to their unique antigen-presenting function. In addition, macrophages seem to have more powerful capacity of scavenging exogenous antigen than DC.

Animals↗
PubMed1999

[Enhanced antitumor effects induced by lymphotactin gene-modified dendritic cells after pulsed with tumor antigen peptide].

OBJECTIVE: To evaluate the potent effects of lymphotactin on tumor immunogene therapy and to improve the therapeutic efficacy of dendritic cells (DCs)-based vaccine, the protective and therapeutic effects of tumor antigen peptide-pulsed lymphotactin gene-modified dendritic cells were investigated. METHODS: In the tumor model of 3LL Lewis lung carcinoma, mouse bone marrow DCs transduced with mouse lymphotactin gene by adenovirus vector (Ltn-DC) were pulsed with MHC-I-restricted, 3LL cell-specific tumor peptide Mut 1 (FEQNTAQP), and used to vaccinate syngeneic mice or to treat the preestablished tumor-bearing mice with spontaneous pulmonary metastases. RESULTS: Immunization with Mut 1 peptide-pulsed Ltn-DC induced specific CTL against 3LL cells and induced protective antitumor immunity, which rendered the immunized mice resistant completely to 3LL tumor challenge. In vivo depletion of immune cell subsets with mAbs demonstrated that the protective immunity induced by Mut1 peptide-pulsed Ltn-DC in the induction phase was dependent on both CD4+ T cells and CD8+ T cells rather than NK cells, and in the effector phase on CD8+ T cells rather than CD4+ T cells or NK cells. CD28/CTLA4 pathway of T cell costimulation and IFN-gamma were also necessary for induction of antitumor immunity by Ltn-DC pulsed with Mut1 peptide. Treatment with Mut1 peptide-pulsed Ltn-DC significantly inhibited the 3LL spontaneous pulmonary metastases of the preestablished tumor-bearing mice and exhibited obvious therapeutic effects. CONCLUSIONS: Our data suggest that Ltn gene modified DCs are more potent in the induction of protective and therapeutic antitumor immunity through the preferential chemotaxis of DCs on T cells. Vaccination with tumor antigen-pulsed Ltn-DC may be a novel approach to immunotherapy of cancer.

Animals↗
PubMed1999

[Investigation of serum immunosuppresive acidic protein levels in gynecological tumor].

OBJECTIVE: To study the clinical significance for measureing serum immunosuppresive acidic protein (IAP) levels to diagnoze and follow up survey patients with the gynecological tumor. METHODS: Serum IAP levels were determined by IAP-single radial immunodiffusion test in 235 patients with gynecological tumor, 38 patients had benign ovary tumor, 41 were malignant ovary tumor, 66 hysteromyoma, 34 cervical carcinoma, 16 endometrial carcinoma, 27 received chemotherapy, and 13 had tumor recurrence. The control group consisted of 50 health women. RESULTS: The serum IAP level was (889 +/- 208) mg/L in malignant ovary tumor, and higher than that of the health women and benign ovary tumor, (P < 0.01). In patients with cervical carcinoma and endometrial carcinoma, the IAP level was (741 +/- 213) and (763 +/- 209) mg/L respectively, and higher than that of the health women and benign ovary tumor (P < 0.01). After chemotherapy, the serum IAP level of malignant ovary tumor was decreased. In patients with recurrence of ovary tumor, the IAP levels was increased to compare with the health women (P < 0.01), the incidence of the abnormal value was 100%. CONCLUSION: Detecting IAP level of the gynecological tumor may be an auxiliary index for monitoring gynecological tumor and identifying whether it is benign or malignant.

Adult↗
PubMed1999

[Pathological changes of intracranial arteries in cerebral infarction].

OBJECTIVE: To investigate the cause and severity of intracranial arterial lesions in extensive cerebral infarction (CI). METHODS: 78 consecutive autopsy cases were studied. They included 58 cases of CI and 20 cases of other diseases as control. Medium-sized intracranial arteries and their main branches, small intracerebral arteries, and arterioles were examined with light microscopy. Quantitative analysis was made with computer. RESULTS: CI due to embolism was seen in 33/58 (56.9%) cases, thrombosis in 11/58 (19%), and unknown etiology in 14/58 (24.1%). The mean LA-VA ratios of the medium-sized intracranial arteries and their main branches, small intracerebral arteries and arterioles were lower in the CI patients than in the controls (P < 0.01). Atherosclerotic narrowing of the distal part of M1 segment of both lateral cerebral middle arteries, the basilar arteries and the main branches in the patients with thrombosis was markedly more severe than in those with embolism (P < 0.05, P < 0.01). CONCLUSION: Patients with CI have arterial lesions of different levels but the principal portions of cerebral artery lesions are the medium-sized intracranial arteries and their main branches. Thrombosis and embolism with medium, severe atherosclerotic narrowing of several arteries may play an important role in causing extensive CI in the middle aged and the elderly.

Aged↗
PubMed1999

[Protein tyrosine kinase activation in the repair of rat gastric mucosa after damage].

OBJECTIVE: To investigate the possible role of protein tyrosine kinase (PTK) and its effect on nuclear protein phosphorylation and activating protein 1 (AP-1) activity in the rat gastric epithelial restitution. METHODS: Rat gastric mucosae were damaged with 20 mmol/L Deoxysodium cholate (DOC). Mucosal scrapings from the oxyntic gland area were obtained 3 hours after damage. The cellular membrane and nuclear fractions were dissociated from the extraction of the mucosal scrapings to assay the activity of PTK and AP-1, and the phosphorylation of nuclear protein. Different blockers, including Tyrphostin-51 for PTK and PD098059 for mitogen-activated protein kinase kinase (MAPKK), were used to study the signaling control for a better understanding of the mechanisms of gastric reepithelium. RESULTS: 20 mmol/L DOC caused moderate damage in rat gastric mucosae. PTK activity 3 hours after damage was 1 time that of the primary level, while nuclear protein phosphorylation level was increased about 4 folds. Tyrphostin-51 and PD098059 inhibited such effects by 85.3% and 61.6%, respectively. AP-1 activity was also greatly elevated after gastric mucosal damage and the effect was attenuated by both Tyrpsotin-51 and PD098059. CONCLUSION: PTK activation improves the rat gastric mucosal repair ability in the early phase after damage through the promotion of nuclear protein phospharylation and the increase in AP-1 activity. The effect of PTK is greatly magnified when the signals fly into the cellular nuclea, mainly through MAPK pathway.

Animals↗
PubMed1999

[Reconstitution and protection of murine hematopoiesis by second transplantation with bone marrow cells containing mutant human DHFR gene from primary generation murine].

OBJECTIVE: To observe the effect of donor murine bone marrow, which was transfected in vivo with mutant hDHFR gene, on the reconstitution and protection of hematopoiesis of lethally irradiated recipient mice. METHODS: Mice bone marrow transduced in vivo with mutant hDHFR gene were used for transplantation. After whole bodily irradiated (8.5-9.0 Gy) and then transplanted with the transduced marrow, the recipients were treated with methotrexate (4 mg/kg twice a week for the first week; and then 10 mg/kg twice a week). The survival rate and blood picture of the recipients as well as the integration and expression of hDHFR gene were studied by using PCR and Southern blotting. RESULTS: The hematopoiesis of the recipient mice could be reconstituted and protected from lethal toxicity of high dose methotrexate. It was confirmed that hDHFR gene was integrated into hematopoietic cell as well as some tissues genomic DNA and expressed successfully in the recipients. CONCLUSION: Donor mice bone marrow transfected with mutant hDHFR gene can effectively reconstitute and protect hematopoiesis in lethally irradiated recipient mice.

Animals↗
PubMed1999

[Homozygous deletion and methylation of p16 and p15 gene in acute leukemia].

OBJECTIVE: To investigate the frequency of p16 and p15 gene inactivation in acute leukemia and to evaluate its clinical significance. METHODS: Fifty-six patients with newly diagnosed acute leukemia was studied. PCR technique was used to detect homozygous deletion of p16 and p15 gene, restriction enzyme-PCR technique was used to detect gene methylation, and TdT-mediated dUTP-digoxygenin end-labeling (TUNEL) technique was used to detect cell apoptosis. RESULTS: p16 and/or p15 gene inactivation was detected in 33 of the 56 patients, including 23/38 (60.5%) of the ALL patients (T-ALL 12/16, B-ALL 11/22) and 10/18 (55.5%) of the ANLL patients. For All patients, methylation was the major pathway of p16 and p15 gene inactivation. Patients with p16 and/or p15 gene inactivation had a delayed apoptosis, a poor response to chemotherapy, a lower remission rate and a shortened remission duration. CONCLUSION: The inactivation of p16 and p15 gene plays a key role in the pathogenesis of acute leukemia.

Apoptosis↗
PubMed1999

[Expression of multidrug resistance-associated protein in human non-small cell lung cancer].

OBJECTIVE: To investigate the expression of the multidrug resistance-associated protein(MRP) gene and MRP in human non-small-cell lung cancer tissues and to determine whether such expression was related to cell type, differentiation, tumour size, lymph node metastasis and prognosis. METHODS: 92 paraffin-embeded lung tumor samples (43 squamous cell carcinoma, 49 adenocarcinoma) and 16 fresh non-small-cell lung cancer samples were examined by using immunohistochemistry method and the reverse transcription-polymerase chain reaction (RT-PCR) technology respectively. RESULTS: The expression of MRP mRNA and MRP were detectable in 31% (5-16) and 54% (50/92) of non-small-cell lung cancer specimens respectively. Eighteen(42%) squamous cell carcinoma specimens and thirty-two(65%) adenocarcinoma specimens showed positive immunostaining for MRP(P < 0.05). The expression of MRP was not related to tumour size, lymph node metastasis and cell differentiation significantly(P > 0.05). The five-year survival rate after operation of patients with MRP-positive tumours and MRP-negative tumours were 16% (8/50), 52% (22/42) respectively. Patients with MRP-positive tumours had shorter survival time than the MRP-negative patients significantly(P < 0.01). CONCLUSIONS: Adenocarcinoma had higher MRP expression than squamous carcinoma significantly, positive MRP immunostaining appears to be an independent indicator of poor prognosis in NSCLC.

Adult↗
PubMed1999

[Immunohistochemical study of angiogenesis of axillary lymph node metastasis in human breast carcinoma].

OBJECTIVE: To study angiogenesis of axillary lymph node metastases (including micrometastatic foci and metastatic tumors) in breast carcinoma and the relationship between microvessel density (MVD) and metastasis. METHODS: Thirty-seven breast cancer tissues and 121 metastatic axillary lymph nodes were collected from breast cancer patients and studied immunohistochemically. MVD was counted by means of microvideo system under 100x magnification. The diameter of each micrometastasis was measured with a micrometer. RESULTS: The mean diameter of 13 micrometastatic foci was 210 +/- 37 microns. No blood vessel formation was found. MVD of the primary tumor and that of metastatic tumor in the axillary lymph node was 93.8 +/- 21.8 and 89.3 +/- 18.4, respectively (P > 0.05). The distribution of microvessels of the metastatic tumor in the lymph node and that of the primary tumor was similar, being higher at the periphery than at the center. CONCLUSION: Micrometastatic foci of breast carcinoma in the axillary lymph node do not have new blood vessel formation. Their further growth, however, depends on neo-angiogenesis. Treatment based on inhibition of angiogenesis may be efficacious in the prevention of micrometastatic foci from developing into metastatic tumor in lymph node.

Axilla↗
PubMed1999

[The expression of MRP gene relates to the pathological features of lung cancer].

OBJECTIVE: To evaluate the expression of MRP gene and its relation to pathological features in lung carcinoma. METHODS: A series of 35 resected primary lung cancer tissues from 9 post-chemotherapy and 26 untreated patients and adjacent normal lung tissues and 28 lymph node tissues were analyzed for MRP gene expression by RT-PCR method. RESULTS: Positive expression rate of MRP gene was 54% in 35 cases with primary lung cancer, 14% in tissues adjacent to the carcinoma site and the difference was significant (P < 0.005), the positive rate of MRP gene expression in metastatic lymph node tissues was 53%. In 9 cases of pre-operative chemotherapy, the positive expression rate of MRP gene was higher than that in 26 cases without chemotherapy. Nineteen of 35 tumors were found to show positive expression of MRP gene, comprising 11 of 18 adenocarcinoma, 9 of 15 squamous cell cancer. The relapse or metastasis rate with MRP-positive cases was higher(55%) than that with MRP-negative (15%) by follow-up of these patients. CONCLUSIONS: There are overexpression of MRP gene in primary lung cancer tissues. Preoperative chemotherapy may play inductive role in lung cancer multidrug resistance. The positive expression of MRP gene in lung cancer tissues is in accord with its lymph node tissues. Positive expression of MRP gene does not necessarily be associated with tumor size, clinical type and TNM stages, but it could be regarded as one poor prognostic factor.

Biomarkers, Tumor↗
PubMed1999

[Expression of multidrug resistance-associated protein (MRP) and lung resistance protein (LRP) in human rectal carcinomas and its clinical significance].

OBJECTIVE: To investigate the expression and clinical significance of multidrug resistance-associated protein(MRP) and lung resistance protein(LRP) in rectal carcinoma. METHODS: Fiftyseven paraffin embeded primary rectal carcinoma specimens were examined by immunohistochemical staining. RESULTS: Of the 57 tumour specimens examined, 28(49.1%) and 24(42.1%) were positively immunostaned for MRP and LRP, respectively. Co-expression of the two proteins was observed in 10(17.5%) specimens. Positive immunostaning of either of the two proteins was not correlated with cell differentiation and Dukes stage (P > 0.05). Patients with MRP-positive tumours had shorter survival than MRP-negative patients (P < 0.05). No such correlation was found for LRP expression, nor was found between MRP and LRP expression. CONCLUSION: Positive MRP expression in rectal carcinoma appears to be an independant factor of prognostic significance. To examine its expression may help guide rational comprehensive therapy of rectal carcinoma.

Adult↗
PubMed1999

[Histocytopathological study on gastric mucosa of spleen deficiency syndrome].

OBJECTIVE: To explore the pictures of gastric mucosa of Spleen deficiency syndrome, and the relationship between the degree of pathological changes of gastric mucosa and types of Spleen deficiency syndrome. METHODS: One hundred and eighty-eight Spleen deficiency patients with organic diseases of heart, lung, liver, gallbladder, pancreas, intestine and kidney excluded were examined their gastric mucosa. Tests of histopathology and subcellular ultrastructure were conducted by using optical microscope, electron scanning microscope, electron transmission microscope and histochemical staining methods. RESULTS: The gastric mucosa of Spleen Qi deficiency and Spleen Yang deficiency patients could either be affected with organic lesion (type G) or unaffected (type F); the gastric mucosa of Spleen Yin deficiency and Spleen deficiency with Qi stagnation were both affected by gastric lesions, and the degree of their lesions was more serious than that of Spleen Qi deficiency of type G and Spleen Yang deficiency of type G, P < 0.05-0.01. CONCLUSION: Pathological changes did not necessarily occur in the gastric mucosa of Spleen deficiency patients; the degree of pathological changes was relevant with the evolution of Spleen deficiency types.

Adult↗