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Biomedical subjects

Z Ding

Publications and source records attributed to Z Ding.

At least 73 records · Page 4Linked to original sources
PubMed1999

Differential expression of antiapoptotic gene BAG-1 in human breast normal and cancer cell lines and tissues.

BAG-1 is an antiapoptotic protein that binds to and enhances the antiapoptotic activity of Bcl-2. It binds several growth factor and hormone receptors and modulates their function. BAG-1 was also shown recently to be expressed as four protein isoforms, p50, p46, p33, and p29, through alternative translation initiation. Although many apoptosis-associated genes have been linked to oncogenesis of human breast cancer, the role of BAG-1 has not been fully elucidated. In this study, we examined the expression of BAG-1 RNA or protein isoforms and its interacting antiapoptotic proteins, Bcl-2 and BcI-X(L), in breast normal and tumor cell lines and tissues by Northern or Western blot analysis. We provide convincing evidence that both BAG-1 RNA and protein are overexpressed in human breast cancer cell lines. More importantly, we found that the expression of two isoforms of BAG-1, p46 and p33, was also much higher in breast primary tumors. The expression of Bcl-2 and Bcl-X(L) correlated with that of BAG-1 in breast normal and carcinoma cell lines but not tissues. Our study suggests that BAG-1 isoforms may serve as a molecular marker, independent of Bcl-2 and Bcl-X(L), for human breast cancer.

Adenocarcinoma↗
PubMed1999

Effect of tumor necrosis factor-alpha and interleukin-2 on spleen lymphocyte migration in mouse skin.

Tumor necrosis factor-alpha (TNF-alpha) and interleukin-2 (IL-2) are reported to enhance lymphocyte binding to endothelial cells in vitro. We examined these two agents on lymphocyte migration in vivo. Spleen lymphocytes were radiolabeled with tritiated uridine (3H-UR) and then injected i.v. into mice. Each cytokine (TNF-alpha or IL-2) or both cytokines were then injected intradermally on the back of mice. The results demonstrated that TNF-alpha stimulates lymphocyte migration in vivo in dose-dependent fashion. Kinetic analysis demonstrated that migration with TNF-alpha started at 3 h, peaked at 6 h, followed by a gradual decline back to baseline at 24 h. IL-2, on the other hand, was nearly inactive, and did not augment lymphocyte migration over and above that induced by TNF-alpha when both cytokines were injected together.

Animals↗
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

Interaction between gene p53 and oncogene mdm2 in human glandular lung cancer cell line GLC-82.

OBJECTIVE: To study the interaction between oncogene mdm2 and wp53 in human glandular lung cancer cell line GLC-82. METHODS: By lipofectamine-mediated DNA transfection, wp53 and mdm2 were transfected separately or co-transfected into GLC-82 cells via retrovival vector pDOR-neo, a carrier of wp53 and mdm2. RESULTS: The growth of GLC-82 cells was blocked and their DNA synthesis inhibited by wp53, its colony-forming rate in soft agar culture and the tumorigenicity in nude mice declined and mdm2 antagonized the function of wp53. CONCLUSION: After the recombinant vector pDOR-mdm2 was transfected into GLC-82 cells containing wp53, mdm2 partially deprives wp53 of its function of inhibiting the growth of GLC-82 cells.

Adenocarcinoma↗
PubMed1999

[Prediction of the outcome of dysplasia of esophageal epithelium by high resolution image analysis].

OBJECTIVE: To predict the outcome of dysplasia of esophageal epithelium by means of high resolution image analysis(HRIA). METHODS: Asymptomatic adults were examined for balloon cytology of the esophagus in 1983 from Heshun Commune of Linxian County. Ninety three cases of severe dysplasia and 122 cases of mild dysplasia of the esophagus were selected for this study. By means of an Axiomat-microscope equipped with TV-camera, 100 normal nuclei of well-preserved cells in the intermediate layer of Pap-stained squamous epithelium were randomly examined. RESULTS: Of the 93 cytologically diagnosed severe dysplasia cases, 24, 14 and 7 progressed to carcinoma in 3, 5 and 9 years, respectively. In the other 48 cases, dysplasia remained stable or regressed to normal. The other cases were used as the control. According to chromatin features, correct diagnosis of cases was achieved by HRIA in 75.0%(18/24), 85.7%(12/14) and 85.7%(6/7) of the cases examined, respectively (P < 0.001). Of the 122 cytologically diagnosed mild dysplasia, 16, 13 and 12 cases progressed to carcinoma in 3, 5 and 9 years, respectively. The other 81 cases remained stable or regressed to normal. Correct diagnosis was made by HRIA in 93.8%(15/16), 76.9%(10/13) and 83.3%(10/12) of the cases examined, respectively (P < 0.001). CONCLUSION: Chromatin nuclear features examined by HRIA can predict the outcome of precancerous lesions and discriminate progressor from non-progressor ones. It can be used as surrogate endpoint biomarkers for the evaluation of efficacy of chemoprevention trial.

Adult↗
PubMed1999

[Long-term effect of treating patients with precancerous lesions of the esophagus].

OBJECTIVE: To report long term therapeutic effect in patients with esophageal pre-cancerous lesions in high-risk area of esophageal cancer. METHODS: The therapeutic trial enrolled 2,531 cases of severe dysplasia and 3,393 cases of mild dysplasia. A 2-arm randomized, placebo-controlled design was used in which the participants received Zeng Sheng Ping (ZSP, an herbal composite), retinamide or placebo for cases with severe dysplasia and riboflavin or placebo for those with mild dysplasia. RESULTS: Treatment with ZSP and retinamide decreased malignant transformation rate of severe dysplasia by 52.2% and 43.2%, respectively after 5 years of treatment. When the treatment had been discontinued for 4 years, the rate of malignat transformation was decreased by 42.1% and 38.2% respectively, which remained significantly higher than that of the placebo-treated control. Riboflavin treatment was continued for 9 years. At the end of 5-year medication, the malignant transformation rate decreased by 34.8%, which was not significantly different from that of the placebo control. When the treatment was continued up to 9 years, the rate was further decreased to 37.0%, which became statistically significant. CONCLUSION: ZSP, retinamide and riboflavin treatment can effectively prevent esophageal dysplasia from transforming into carcinoma.

Adult↗
PubMed1999

[Detecting microorganisms in soil by PCR and molecular hybridization].

PCR and molecular hybridization provide new methods to detect microorganisms in environment. A simple, sensitive protocol was developed to detect Bacillus thuringiensis HD-1 in soil by PCR and Southern Blotting in this study. Methods of extracting DNA from soil and purification were compared. By a modified total DNA extraction from soil and purification, followed by PCR and Southern Blotting, strain HD-1 released into soil can be detected with a sensitivity of 2.2 x 10(2) cells/g soil. By using other specific primers, this detection protocol can be widely used in the research of ecology and risk assessment of genetically engineered microorganisms released into environment.

Bacillus thuringiensis↗
PubMed1998

Human BAG-1/RAP46 protein is generated as four isoforms by alternative translation initiation and overexpressed in cancer cells.

Previously, a Bcl-2-interacting protein, BAG-1, was cloned from mouse cells and was shown to interact with several other proteins and to be important for inhibition of apoptosis. Human BAG-1 (hBAG-1) cDNA, recently isolated by us and two other groups, has been shown to be identical to a hormone receptor-binding protein, RAP46. However, different molecular masses of hBAG-1 protein products were noted by these three groups. Here we demonstrated that hBAG-1 protein was expressed as four isoforms, designated p50, p46, p33 and p29, with apparent molecular masses of 50 kDa, 46 kDa, 33 kDa and 29 kDa, respectively. Deletion, site-directed mutagenesis and in vitro transcription/translation analysis showed that the four protein products of hBAG-1 were expressed by alternative initiation from four different start codons through a leaky scanning mechanism. Furthermore, we demonstrated that the distinct forms of hBAG-1 have different subcellular localizations, suggesting that they may have distinct functions in the cells. Characterization of hBAG-1 RNA and protein also showed that hBAG-1 was overexpressed in human cervical, breast and lung cancer cell lines. Taken together, these data clarify the conflicting observations reported in the literature and suggest that hBAG-1 is expressed as four forms of protein products, which may play a differential role in apoptosis and oncogenesis of human cells.

Alternative Splicing↗
PubMed1998

Unusual properties of thermally sensitive oligomer-enzyme conjugates of poly(N-isopropylacrylamide)-trypsin.

Reversible soluble-insoluble oligomer-enzyme conjugates have been prepared by conjugating a thermally sensitive oligomer, poly(N-isopropylacrylamide) [poly(NIPAAm)] to trypsin. The conjugates can catalyze enzymatic reactions in solution and then may be separated from the solution by thermal precipitation. One special feature of the conjugates is that every poly(NIPAAm) chain has only one end attachment to the enzyme, so that the loss of enzymatic activity due to steric hindrance should be minimized. Conjugates with various numbers of oligomer chains per trypsin molecule were prepared. Surprisingly, the conjugates increased in enzymatic activity with increasing oligomer conjugation to the native trypsin. The trypsin active sites in the conjugates were accessible to large molecules, such as soybean trypsin inhibitor (MW = 21,500). The enzyme conjugates were more stable than native trypsin, both in solution and in the precipitated phase. On the other hand, the conjugates lost enzymatic activity faster than native trypsin when the temperature was repeatedly cycled through the lower critical solution temperature (LCST) of the poly(NIPAAm). The recovery of the conjugates by thermal precipitation in each cycle was over 95% even after 14 cycles through the LCST.

Acrylamides↗
PubMed1998

Coronary hemodynamics in endothelial NO synthase knockout mice.

For the specific analysis of endothelial NO synthase (eNOS) function in the coronary vasculature, we generated a mouse homozygous for a defective eNOS gene (eNOS-/-). Western blot as well as immunohistochemical staining revealed the absence of eNOS protein in eNOS-/- mice. Aortic endothelial cells derived from eNOS-/- mice displayed only background levels of NOx formation compared with wild-type (WT) cells (88 versus 1990 pmol NOx x h-1/mg protein-1). eNOS-/- mice were hypertensive (mean arterial pressure, 135 +/- 15 versus 107 +/- 8 mm Hg in WT) without the development of cardiac hypertrophy. Coronary hemodynamics, analyzed in Langendorff-perfused hearts, showed no differences either in basal coronary flow or in maximal and repayment flow of reactive hyperemia. Acute NOS inhibition with Nomega-nitro-L-arginine methyl ester (L-NAME) in WT hearts substantially reduced basal flow and reactive hyperemia. The coronary response to acetylcholine (ACh) (500 nmol/L) was biphasic: An initial vasoconstriction (flow, -35%) in WT hearts was followed by sustained vasodilation (+190%). L-NAME significantly reduced vasodilation in WT hearts (+125%) but did not alter the initial vasoconstriction. In eNOS-/- hearts, the initial vasoconstriction was augmented (-70%), whereas the ACh-induced vasodilation was not affected. Inhibition of cyclooxygenase with diclofenac converted the ACh-induced vasodilation into vasoconstriction (-49% decrease of basal flow). This effect was even more pronounced in eNOS-/- hearts (-71%). Our results demonstrate that (1) acute inhibition of eNOS reveals a role for NO in setting the basal coronary vascular tone as well as participation in reactive hyperemia and the response to ACh; (2) chronic inhibition of NO formation in eNOS-/- mutant mice induces no changes in basal coronary flow and reactive hyperemia, suggesting the activation of important compensatory mechanisms; and (3) prostaglandins are the main mediators of the ACh-induced vasodilation in both WT and eNOS-/- mice.

Animals↗
PubMed1998

Relation between the structural asymmetry of coronary branch vessels and the angle at their origin.

The relationship between the geometry of branch points on the left anterior descending coronary artery, and the morphometry of the proximal portions of the daughter vessels, was examined. The geometry at 23 branch points on 15 human hearts was derived from multiplane contrast angiograms, and the morphometry at 29 sites along the daughter vessels was obtained from transverse sections using computerized techniques. The angle of the branch at which the daughter originated was positively correlated with the maximum thicknesses of the intima and media, and with their circumferential asymmetry. The results suggest that large branch angles may favor eccentric intimal thickening, a phenomenon which may predispose to lipid accumulation and atherosclerosis.

Cadaver↗
PubMed1998

Glutamate receptors on postganglionic sympathetic axons.

The present study demonstrates that approximately 36% of postganglionic sympathetic axons in gray rami express receptors for the N-methyl-D-aspartate receptor 1 subunit of the N-methyl-D-aspartate receptor and 10% express the glutamate receptor 1 subunit of the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor. If these receptors are active, glutamate released from primary afferent terminals could activate these receptors resulting in the release of noradrenaline and other substances from postganglionic sympathetic neurons. This interaction would constitute a non-synaptic, sensory-sympathetic, peripheral reflex that might be important in local vascular control and in pain states that have a sympathetic component.

Animals↗
PubMed1998

Variability of the planarity of the human aortic bifurcation.

The susceptibility of vascular branches to atherosclerosis is believed to be due in part to the unusual fluid dynamic environments that the vessel wall experiences in these regions. As vascular geometry is a primary determinant of the local haemodynamic environment, it is of interest to quantitate the geometric features of vascular branches and their variability. The present research focusses on branch planarity, using axial magnetic resonance images of the aortic bifurcations of 20 healthy subjects. The in vivo images were processed to obtain vector representations of the vessel axes at the bifurcation, from which the planarity of the bifurcation was derived using a novel robust definition. Three-dimensional reconstructions of the bifurcations were rendered using computer graphics techniques to demonstrate the variability of the planarity of this region of the vasculature; this variability might be related to variable predispositions to atherosclerosis at the aortic bifurcation.

Aorta, Abdominal↗
PubMed1998

Oxidative and malondialdehyde modification of low-density lipoprotein: a comparative study of binding and degradation by macrophages and endothelial cells.

Comparative study of oxidatively modified low-density lipoprotein (Ox-LDL) and malondialdehyde-modified low-density lipoprotein (MDA-LDL) is important for further understanding the biological properties of Ox-LDL, such as its toxic effects, immunogenicity and multiplicity of scavenger receptor binding. In this study, the characteristics of Ox-LDL and MDA-LDL binding and degradation were compared. The results show that when their degree of modification (as determined by relative electrophoretic mobility) was similar, the binding and degradation of Ox-LDL by the macrophage cell line P388D1 were greater than those of MDA-LDL. The binding and degradation of Ox-LDL by macrophages and human umbilical vein endothelial cells increased with the degree of modification. In addition, Ox-LDL or MDA-LDL could competitively inhibit binding of labelled Ox-LDL or labelled MDA-LDL to their respective macrophage receptors, and could partially inhibit each other.

Animals↗
PubMed1998

Computer-assisted design and manufacture of posterior full crowns.

OBJECTIVE: To build an experimental system for the computer-assisted design (CAD) of full crowns and to obtain data for computer-assisted manufacturing (CAM) of full crowns. MATERIALS AND METHODS: Three steps are involved in building the system: measuring the prepared tooth, the adjacent mesial and distal teeth, and the opposing teeth by means of digital speckle correlation; reconstructing the shape of the measured teeth; and developing CAD for full crowns. The standard shape of the corresponding tooth was modified to fit the defective tooth on the basis of buccolingual and occlusal-gingival distance as well as the occlusal relationship of the defective tooth. RESULTS: CAD for full crowns was developed and was obtained for CAM of posterior full crowns. CONCLUSIONS: The CAD method for full crowns is convenient and economical and can be used for anterior and posterior crown design, copying, and veneer.

Bicuspid↗
PubMed1998

[National epidemiological study on obesity of children aged 0-7 years in China 1996].

OBJECTIVE: To study on obesity of children aged 0-7 years in 11 cities in 1996. METHODS: The sampling size was 208, 513. The children were divided into 9 groups: birth-, 1 mo-, 6 mo-, 1 yr, 2 yr-, 3 yr, 4 yr-, 5 yr-, 6-7 yr. RESULTS: The prevalence of overweight was 4.2% (M4.2%, F4.2%); and of obesity, 2.0%(M2.2% F1.9%). The obesity to overweight ratio (ORR) was 2.1%(M1.9%, F2.2%). The adiposity rebound age (ARA) was 5 years. The adiposity rebound ratio (ARR) was 3.2 for ARR1 (M2.9%, F.5%) and 2.0 for ARR2 (M1.7%, F2.4%) in obese children and 3.5 for ARR1 (M 3.5, F3.5) and 2.5 for ARR2 (M2.8, F2.8) in overweight children respectively. The secular trend of prevalence of childhood obesity during 1986-1996 showed that the prevalence of obesity increased annually at 9.1% (M10%, F8.7%). CONCLUSION: The obesity has already been a severe health and social problem of preschool children in China. The increment of prevalence of obesity during 1986-1996 has been out of control. The earlier of ARA and the larger of OOR is an important risk factor of increasing of obesity. 1 year and 5 years after birth, predicted by ARR, are two critical periods of obesity control in preschool children in China.

Child↗
PubMed1998

[Production of purified Japanese encephalitis vaccine from Vero cells with roller bottles].

OBJECTIVE: To study the production process of purified Japanese encephalitis (JE) vaccine from Vero cells cultivated in roller bottles to improve the quality of JE vaccine. METHODS: The 15 L roller bottles were used for propagation of Vero cells and JE virus, then the virus was inactivated, concentrated, treated by protamine sulphate, purified by sucrose gradient density centrifugation and lyophylized as final product. RESULTS: Three batches of high quality lyophylized vaccine were produced and the quality control tests of vaccine for human use had been passed. CONCLUSION: Using roller bottles to cultivate continuous cell line-Vero cells for JE vaccine production is feasible.

Animals↗