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Biomedical subjects

B Zhang

Publications and source records attributed to B Zhang.

At least 505 records · Page 28Linked to original sources
PubMed1996

Negative regulation of peroxisome proliferator-activated receptor-gamma gene expression contributes to the antiadipogenic effects of tumor necrosis factor-alpha.

Recent studies indicate that a peroxisome proliferator-activated receptor, PPAR gamma, functions as an important adipocyte determination factor. In contrast, tumor necrosis factor-alpha (TNF alpha) inhibits adipogenesis, causes dedifferentiation of mature adipocytes, and reduces the expression of several adipocyte-specific genes. Here, we report that treatment of 3T3-L1 adipocytes with TNF alpha resulted in a time- and concentration-dependent decrease in PPAR gamma mRNA expression to the level detected in preadipocytes. PPAR gamma mRNA levels were reduced by 95% with 3 nM TNF alpha treatment for 24 h. Half-maximal effects were seen after 3 h treatment with 3 nM TNF alpha or with 50 pM TNF alpha (24-h exposure). Parallel reductions in PPAR gamma protein levels were also observed after treatment of 3T3-L1 adipocytes with TNF alpha. Using a ribonuclease protection assay, both alternatively spliced PPAR gamma isoforms (gamma 1 and gamma 2) were shown to be negatively regulated by TNF alpha. The down-regulation of PPAR gamma by TNF-alpha preceded the diminution in expression of other adipocyte-specific genes including CCAAT/enhancer binding protein and adipocyte fatty acid-binding protein (aP2). The effect of TNF alpha was specific for the gamma-isoform of PPARs, since the expression of PPAR delta mRNA was not affected by treatment with TNF alpha. Low level constitutive expression of PPAR gamma in 3T3-L1 adipocytes (at levels approximately 2- to 3-fold higher than in preadipocytes) partially blocked the inhibitory effect of TNF alpha on aP2 and adipsin expression. These findings support the following conclusions: 1) PPAR gamma expression is necessary for the maintenance of the adipocyte phenotype. 2) PPAR gamma, but not PPAR delta, expression is sufficient to attenuate TNF alpha-mediated effects on adipocyte phenotype. 3) Reduced PPAR gamma gene expression is likely to represent an important component of the mechanism by which TNF alpha exerts its antiadipogenic effects.

3T3 Cells↗
PubMed1996

[The effects of LTA and plaque on the periodontal tissue of the Guinea pig]

40 Guinea pigs were divided into 4 groups.The gingival sulcus of 2 mandibular incisors were irrigated with LPS(Lipopolysaccharide),LTA (Lipoteichoicacid),PL(Subgingival plaque) and NS(Normal saline solution) respectively.2 animals were sacrificed in group of 5 successively at 1,2,3,6,8 week after irrigation.Microscopic examination demonstrated:Only a few penetration of inflammatory cells lay in the gingival tissue in NS control group.Significant infiltrate associated with evident crystal resorption were noted at 1st week and active remodeling took place at 4th,5th week in LPS group.Enhancing accumulations of plaque calculus with weak inflammation could be seen in LTA group.Not only accumulations of plaque and calculus but also penetration of inflammation with resorption of bone were seen in PL group.Their effects on the periodontal tissue of Guinea pig showed evident different.These findings served further expression the possible mechanisms of periodontal diseases.

Journal Article↗
PubMed1996

Medium-term effects of betaxolol monotherapy and combination therapy with nitrendipine on lipoprotein and apolipoprotein metabolism in patients with mild to moderate essential hypertension.

The objective of this study was to assess the medium-term effects of betaxolol, a long-acting, lipid-soluble, cardioselective, beta-adrenergic antagonist, alone and in combination with nitrendipine on blood pressure (BP) and metabolism of lipid, lipoprotein and apolipoprotein in patients with mild to moderate hypertension. Forty-seven patients (21 men, 26 women, average age 54 years) participated in an open controlled clinical trial. After a 4-week washout period, all of the patients received betaxolol monotherapy at a dose of 5-10 mg daily for 6 months (Phase I). From month 7 through month 12 (Phase II), half of the total patients (Group B, n = 23) with diastolic blood pressure (DBP) of 95 mm Hg or more at the end of Phase I were also given nitrendipine (10-20 mg, once daily), while the remaining patients (Group A, n = 24) continued to receive only betaxolol. Systolic blood pressure (SBP), DBP, and heart rate (HR) were monitored once monthly. Serum lipid profiles were measured at study entry and after 6 and 12 months of therapy. Betaxolol significantly reduced SBP, DBP, and HR in both groups during Phase I, and the reductions in SBP and DBP were markedly less in Group B than in Group A. During Phase II, the additional reduction of SBP and DBP to levels similar to those in Group A was achieved by betaxolol in combination with nitrendipine, and HR was slightly but significantly increased. Betaxolol monotherapy reduced serum levels of high density lipoprotein cholesterol (HDL-C) and increased levels of triglyceride, apolipoprotein (apo) C-II and apo C-III. Combination therapy with betaxolol and nitrendipine increased serum apo A-I but did not affect other lipid profiles. Our results indicate that betaxolol is an effective antihypertensive drug which has a preferable effect on HR and HDL profiles when combined with nitrendipine.

Adrenergic beta-Antagonists↗
PubMed1996

[Prevention and treatment effect of niacin on FES: experimental study].

OBJECTIVE: On the basis of fat embolism syndrome animal model injected with homologous dog bone marrow fat, we probed into the prevention and treatment effect of niacin on FES. METHODS: Fourteen dogs were divided into experimental group and control group. In the experimental group, the dogs were injected with homologous dog bone marrow fat accompanied by niacin injection 4 mg/kg. 8 hr intravenously for 48 hours, while in the control group, only bone marrow fat was injected. PaO2, FFA, triglyceride, platelet counts, fat drops in the blood clots of vein were examined at different times. Finally, morphology and pathology of the lungs were observed. RESULTS: There were a slower decrease in PaO2 and platelet counts and no obvious increase in triglycerides and FFA in the experimental group. The amount and diameter of fat drops in the blood clots of vein and in the lungs were less in the experimental group than in the control. Pathological examinations of the lungs demonstrated much less injuries in the experimental group. CONCLUSION: Good prevention and treatment effect of niacin on fat embolism syndrome is suggested.

Animals↗
PubMed1996

Short-term effects of a high-sucrose diet on plasma lipid, lipoprotein cholesterol, tissue lipoprotein lipase and hepatic triglyceride lipase in rats.

Short-term (2 weeks) effects of a high-sucrose diet on plasma lipids, lipoproteins, tissue lipoprotein lipase (LPL) and hepatic triglyceride lipase (HTGL) activities were investigated in rats. Three days of sucrose feeding significantly increased plasma TG (42 +/- 3 mg/dl vs. 56 +/- 2 mg/dl, p = 0.032), while TC increased significantly after 10 days of the diet (50 +/- 2 mg/dl vs. 62 +/- 2 mg/dl, p = 0.0001). HDL-C increased significantly after 3 days of sucrose feeding (36.2 +/- 0.9 mg/dl vs. 42.4 +/- 2.7 mg/dl, p = 0.011). Although LDL-C tended to decrease on days 3, 7 and 10, these changes were not significant. The plasma glucose level did not change during the study. Increased LPL activity in adipose tissue and decreased enzyme activities in skeletal and heart muscles were observed. Adipose tissue LPL returned to the baseline value after 14 days of the diet treatment, while LPL in skeletal and heart muscles remained at the decreased level. HTGL and HTGL/total liver lipase activities were significantly increased after 14 days of the diet. The different responses of lipase activities in various tissues may help to regulate serum lipid and lipoprotein levels in sucrose-fed rats.

Adipose Tissue↗
PubMed1996

Influence of lipopolysaccharide and interleukin-2 on proliferation and synthesis of sulfated macromolecules in cultured rat glomerular epithelial cells.

OBJECTIVE: To investigate the effects of lipopolysaccharide (LPS) and human recombinant interleukin-2 (hrIL-2) on the synthesis of sulfated macromolecules in cultured rat GECs. METHODS: With 3H-thymidine (3H-TdR) and 35S-Na2SO4 dual isotope labelling technique, the proliferation and synthesis of sulfated macromolecules in cultured rat GECs were estimated according to the 3H-TdR uptake and 35SO4(2-)-contents in cell layers respectively. RESULTS: Both LPS (6.25-50.0 micrograms/L) and hrIL-2 (2.5-10.0 kU/L) decreased the uptake of 3H-TdR by GECs (P < 0.05). As for incorporation of 35SO4(2-) into cell layers, the results that both means and adjusted means in hrIL-2 groups were lower than those in controls (P < 0.05) implied that hrIL-2 could inhibit the synthesis of basement membrane HSPG while LPS hindered incorporation through its inhibitory effect on cell proliferation. CONCLUSIONS: We may infer from these results that LPS-like proinflammatory mediators could increase the subpopulation of large pores in capillary wall through the reduction of cell-associated HSPG, and IL-2-like cytokines could contribute to the development of proteinuria through its inhibitory effect on the production of basement membrane HSPG in immune-mediated glomerular disorders.

Animals↗
PubMed1996

[Angioimmunoblastic lymphadenopathy and angioimmunoblastic T-cell lymphoma].

To investigate the clinicopathological changes of angioimmunoblastic lymphadenopathy (AILD) and angioimmunoblastic T-cell lymphoma (AITL), 5 cases of AILD and AITL were analyzed by using immunohistochemistry and Polymerase chain reaction (PCR) methods. The clinical manifestations included general lymphadenopathy, hepatosplenomegaly, fever and hematologic abnormalities. The diagnosis and differentiation of AILD and AITL were depended on the histopathologic features of lymphnodes biopsy. The presence of clusters of clear cells with variable atypia and positivity of T-cell marker were the most important diagnostic criterion for AITL. PCR analysis of TCR-beta rearrangement and EBV-genome was performed on 4 of 5 cases. All of the cases showed clonal rearrangement of TCR-beta and 3 of them were EBV-DNA positive. The results suggest that AILD might be a prelymphomatous lesion, related to EBV infection with a high incidence of developing to malignant lymphoma.

Adult↗
PubMed1996

[Investigation of health status in workers exposed to low-level benzene].

In order to know the health status in workers exposed to low-level benzene, 323 air samples were collected from five workshops of the Corporation, where low-level benzene was emitted from aromatic hydrocarbon devices. Results showed air benzene levels ranged from 0.05-29.25 mg/m3, with an average of 4.57 +/- 6.16 mg/m3, and the highest in the benzene-producing workshop. Four hundred and thirty-seven workers closely-exposed to benzene in five workshops and 150 controls were selected and their peripheral white blood cell count and micronucleus of lymphocytes were determined. Result showed that 1. peripheral white blood cell count of the exposed workers was within the normal range, but obviously lower than that of the controls; 2. proportion of lymphocytic micronucleus was higher in exposed workers than that in unexposed ones, and there was significant difference in it between workers in benzene-producing workshop than that in controls; 3. white blood cell count lowered and proportion of lymphocytic micronucleus increased in the workers, with the increase of air benzene level in the five workshops. All these demonstrate that low-level benzene is harmful to the exposed workers, especially to their genetic materials.

Adult↗
PubMed1996

[Determination of genkwanin in flos Genkwa by HPLC].

In this paper, the method for determining genkwanin in Flos Genkwa was established by HPLC. Detected at 332nm on a Lichrosorb 5 RP-18 column with a mobile phase of methanol-water-acetic acid (65:35:5), the content of genkwanin in Flos Genkwa was determined to be 0.16%. The recovery rate was 95.46% and RSD 1.15%.

Antitussive Agents↗
PubMed1996

[Gene expression of bFGF and intimal hyperplasia of autologous vein grafts in rats].

OBJECTIVE: To establish a model of autologous vein graft through translating jugular vein to aortic artery in 80 Wistar rats, and detect gene expression of basic fibroblast growth factor (bFGF). METHOD: In situ hybridization and reverse transcription polymerase chain reaction (RT-PCR) were used. RESULTS: The expression of bFGF mRNA was more decreased than that of normal artery and vein after transplantation, up to 1 week, the level of bFGF gene expression decreased to the lowest (P < 0.05). Two weeks after transplantation, bFGF transcripts recovered. CONCLUSION: bFGF released from dead and damaged cells of autologous vein graft not only is an important factor that promotes SMC proliferation, but also is a potent stimulator of endothelial regrowth.

Animals↗
PubMed1996

[Morphological changes in intracranial and extracranial arteries of autopsy cases of cerebrovascular diseases].

OBJECTIVE: To determine the distribution and severity of arterial lesions of intracranial and extracranial arteries in stroke patients in Chinese. METHODS: We studied 120 consecutive autopsy cases including 100 cases of stroke (50-80 years) and 20 cases of cancer as controls (50-80 years). Medium intracranial arteries and their primary branches, small intracerebral arteries, arterioles and extracranial carotid arteries (from 16 cases only) were examined with light microscopy. RESULTS: The stroke patients had significantly lower mean LA-VA ratios of the medium sized intracranial arteries and their primary branches, small intracerebral arteries and arterioles than the controls (P < 0.001). The stroke patients had higher mean VW-VR ratios of these arteries than the controls (P < 0.001). Atherosclerotic narrowing of the medium sized intracranial arteries and their primary branch were more severe than those of the extracranial caotid arteries. Moreover, the proximal portion of the primary branch arteries was much more severe than that of extracranial caotid arteries (P < 0.01, P < 0.05) in the stroke patients. CONCLUSION: Stroke patients had atherosclerotic lesions of the intracranial medium sized arteries and their primary branches and sclerotic lesions of the small intracerebral arteries and arterioles. These pathological changes resulted in thickening arterial walls and narrowing arterial lumens.

Aged↗
PubMed1996

[Prognosis of patients with breast cancer related to the timing of operation during menstrual cycle: a report of 218 patients].

We have finished a retrospective study of 218 premenopausal patients who underwent primary surgery for operable breast carcinoma between March 1958 and December 1984. All these patients had available records of menstrual data and had been followed-up for more than 10 years. U-nivariate analysis showed that the menstrual timing of operation, as other known prognostic factors (tumor size, node status, histological grade, TNM classification, adjuvent systemic therapy, etc), had an influence on the patients' outcome. Multivariate analysis by Cox regression model indicated that disease-free rate and overall survival rate of patients operated during the periovulatory phase (days 7-20, 123 cases) were significantly superior to those during the perimenstrual phase (days 1-6 and 21-40, 95 cases) (P < 0.01). There were no significant differences in prognosis between patients who received their operations during the follicular phase (days 4-14, 96 cases) and those during the luteal phases (days 15-40, 122 cases) (P > 0.1). We suggest that the adequate timing of operation should be further determined by prospective, randomized clinical study.

Adult↗
PubMed1996

[A prospective study of early detection for primary liver cancer].

In order to evaluate the effectiveness of early detection for primary liver cancer (PLC), a randomized, prospective study was performed in Shanghai from 1992 to 1995. The study population was 35 through 55 years of age, with serum evidence of HBV infection or tory of chronic hepatitis. Seventeen thousand nine hundred and twenty individuals were randomly to allocated screening group and control group. In the screening group, every individual was checked up by serum AFP test and ultrasound every 6 months and in the control group, they were unchecked. After a mean time of 1.2 years, 38 patients with PLC in the screening group were detected while 18 patients with PLC occur in the control group. In patients from the screening group, 76.8% were in subclinical stage, 70.6% of them were treated by surgical resection with 1-, 2-year survival rate of 88.1% and 77.5%, respectively. However, in the control group, none of patients was in subclinical stage, none of the tumors resected, and none of patients survived over 1 year. The lead time was estimated to be 0.45 years. The cost for detecting an early stage PLC patient is RMB 12,600 (US$1,500). The study indicates that screening in the high risk population of PLC can detect patients in early stage, increase the resection rate and the survival rate. Screening program for PLC carried out in high risk populations is thus recommended.

Adult↗
PubMed1996

[Repairing bone defect with autogenous periosteal pieces in coagulum: experimental study and clinical application].

A 1.5 cm-long bony defect was established in rabbits one each on both sides. The defected area was filled with coagulum of peripheral blood or bone marrow blood, then autogenous pieces of the periosteum was put in the coagulum on one side, while the other side was served as the control without periosteal autograft. The osteogenetic capacity of the periosteum and the influence of different blood coagulum were evaluated by means of X-ray film, histology, the contents of calcium and phosphate in new osteocytes in the defected area, bone tissue morphometry, and computer-assisted image analysis. The autograft of the periosteum had osteogenetic effect. Autologous bone marrow blood had potential osteogenetic capacity, which however, was weaker than that of the periosteum. Peripheral blood coagulum did not have any osteogenetic effect. We have successfully used the periosteum-bone marrow blood complex (bone marrow blood as a carrier) in 12 patients.

Adult↗
PubMed1996

[Surgical treatment of difficult patent ductus arteriosus and related operative complications].

Sixty-nine patients with difficult patent ductus arteriosus (PDA) were retrospectively studied. The PDA included window type (9 patients), aneurysms of the ductus arteriosus(13), large ductus(15), false aneurysms(3), calcified(3), recurrence of ductal patency(5), endarteritis(5) and severe pulmonary hypertension(16). Surgical procedures included ligation of PDA in 51 patients, ligation with Dacron pledget or ribbon in 9, division of PDA under temporary cardiopulmonary bypass in 5. Ruptures of PDA or aorta in 4 patients were repaired respectively with Dacron patch(2) and conduit (2). There were 2 early deaths (2.9%). The mean follow-up was 119 months clinically. All surviors were free from symptoms andcardiac murmur. We conclude that satisfied surgical results rely mainly on proper operative techniques according to different situations of difficult PDA. Surgical correction with Dacron patch or conduit seems to be a simple, safte and reliable method in dealing with the rupture of PDA or aorta.

Adult↗
PubMed1996

[SMC proliferation and its distribution in autologous vein grafts].

SMC proliferation in intimal hyperplasia is a major cause of graft failure. We induced experimental jugular vein to aortic autograft in 120 Wistar rats, and analyzed the SMC proliferation and its distribution in the graft by flow cytometry (FCM) and immunohistochemistry of proliferating cellular nuclear antigen (PCNA) from 2 hours, 6 hours, 24 hours to 1 week, 2 weeks and 4 weeks. Although the number was not apparently increased in autologous vein graft at early stage, SMC proliferation had started. At 1 week after transplantation, the activity of SMC proliferation increased to a maximum, and returned to baseline level 4 weeks. At early stage, the distribution of SMC proliferation located in the media, but at middle stage, both intima and media all presented a relatively higher proliferative activity. The intima formation occurred by the migration of a large population and the proliferation of a relatively small subpopulation of SMC. Therefore, control of SMC proliferation, and migration of autologous vein grafts must be within two weeks after transplantation.

Animals↗