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Biomedical subjects

S Zheng

Publications and source records attributed to S Zheng.

At least 145 records · Page 8Linked to original sources
PubMed1998

[The study of endothelin and endothelin receptors in cyclic human endometrium].

OBJECTIVE: To determine the distribution of endothelin (ET) peptide and endothelin as well as their receptors (ETaR and ETbR) mRNA in human cycling endometrium in order to assess possible role of ET in endometrial reproductive physiology. METHODS: Twenty-three endometrial specimens from gynecological surgery for benign conditions were studied by means of immunohistochemistry, in situ hybridization and computer quantitative image analysis. RESULTS: The expression of ET peptide and ET mRNA in human endometrium varies throughout the menstrual cycle, increasing gradually from proliferative phase to secretory phase, with maximal levels in the pre-menstrual phase. Stromal expression is lower than in glandular epithelium and remains relatively constant in the menstrual cycle. ETaR and ETbR mRNA are detected in normal human endometrium, higher in glandular epithelial cells than in stromal cells. ETaR mRNA expression has no obvious cyclic changes, but ETbR mRNA expressions are higher in secretory endometrium than in proliferative endometrium. The ratio of ETaR/ETbR has also cyclic changes. CONCLUSION: Changes of Expression of ET and ET receptors in the endometrium throughout the menstrual cycle suggest that ET might be important in endometrial regeneration and repair following menstruation, and probably plays a role as the paracrine control of the uterine vascular bed.

Adult↗
PubMed1998

[The changes of sex steroid receptors and morphology in Norplant treated endometrium].

OBJECTIVE: To study the relationship between the changes of sex steroid receptors as well as endometrial morphology and abnormal uterine bleeding induced by Norplant. METHODS: Immunohistochemistry, Western Blot, in situ hybridization and computer image analysis were employed to demonstrate the expression of estrone receptor(ER) progesterone receptor(PR) protein and mRNA as well as morphometric analysis of the endometrium in Norplant users. RESULTS: The content of DNA and the numbers of spiral arterioles decreased in Norplant treated endometrium. The percentage of glandular area in Norplant endometrium was much lower than that in cyclic endometrium. A statistically significant correlation was observed between the percentage of area of glands and abnormal uterine bleeding, as well as serum estrogen(E2) level, but E2 level had no direct relationship with the bleeding abnormality. As the time growing, the percentage of glandular area increased. Immunostaining and relative concentration of glandular and stromal ER in Norplant treated endometrium were significantly weaker and less than all the stage of cyclic endometrium. However, PR, especially stromal PR immunostaining was very intense, which was the same or more than that in all the stage of cyclic endometrium. In situ hybridization detected that the ER and PR mRNA was lower in Norplant treated endometrium than that in cyclic endometrium. The ER mRNA expression was more less abundant than PR mRNA expression. CONCLUSION: These results suggested that poor repair and regeneration of endometrium(especially glands and spiral arterioles) and abnormal expression of ER and PR may be related to pathogenesis of abnormal uterine bleeding induced by Norplant implant.

Adult↗
PubMed1998

[Rejection of non-immunogenic tumor cells transfected with costimulatory molecule B7 after treatment with IFN-gamma in vitro].

OBJECTIVE: To explore immuno-gene-therapy of non-immunogenic tumor. METHODS: Non-immurogenic tumor cells B16 were transfected with B7-1 gene. The B7-1 gene transfected B16 cells (B7+ B16) were treated with recombinant murine interferon-gamma (rmIFN-gamma) in vitro, and then inoculated to C57BL/6 mice. RESULTS: While B7+ B16 cells grew progressively in syngeneic mice, tumorigenicty was significantly reduced when B7+ B16 cells were treated with rmIFN-gamma before inoculation to mice. Flow cytometric analysis of the rmIFN-gamma treated B7+ B16 cells showed significant up-regulation of MHC class I expression. CONCLUSION: For non-immunogenic tumor if the expressions of MHC class I molecules is low, providing co-stimulatory molecule B7 is not enough to reduce tumorigenicity. The B7-1 gene transfected B16 cells become non-tumorigenic or weakly tumorigenic when their MHC class I is up-regulated.

Animals↗
PubMed1998

[Effect of up-regulation of S-AdoMet synthetase on taxol-induced apoptosis in human breast cancer cells].

OBJECTIVE: To investigate the gene regulation of taxol-induced apoptosis. METHODS: Northern blot hybridization, enzyme activity assay of S-AdoMet synthetase and flow cytometry were performed in the investigation of expression in the mRNA level and biological action of S-AdoMet synthetase in taxol-induced apoptosis in human breast cancer cell line (BCap 37). RESULTS: Up-regulation of S-AdoMet synthetase expression was resulted by taxol treatment and the expression peaked at 48 hours. Moreover, the up-regulation of S-AdoMet synthetase was associated with cytotoxicity of antimicrotubule agents including taxol and colchicine. Inhibition rate of S-AdoMet synthetase activity by 1% DMSO was 34% in taxol-treated cells and 14% in taxol-untreated cells compared to control groups, respectively. Posttreatment with 1% DMSO following pretreatment with individual antitumor agent for 3 hr promoted apoptotic cell death of taxol-, colchicine-, and adriamycin-treated BCap37 cells. CONCLUSION: The induction of apoptosis enhanced by post-treatment with DMSO in taxol-treated cells is probably linked to its inhibition on enzyme activity of S-AdoMet synthetase, suggesting that the increased expression of S-AdoMet synthetase possibly plays an important role in protecting cells from DNA fragmentation in taxol-induced apoptosis.

Antineoplastic Agents, Phytogenic↗
PubMed1998

Growth regulation of ovarian cancer cell line HO-8910 by transforming growth factor beta 1 in vitro.

OBJECTIVE: To further understand the role of growth regulation of human ovarian cancer cells by transforming growth factor (TGF) beta 1. METHODS: The cell proliferation, cAMP synthesis, gene expression, and induction of programmed cell death (PCD) in human epithelial ovarian cancer cell line HO-8910 cells exposed to TGF beta 1 in vitro were studied. RESULTS: TGF beta 1 inhibited cell growth and DNA synthesis, and induced G0/G1 arrest in cell cycle. It could also trigger PCD in cells. This induction of PCD may occur within G0/G1 phase. Meanwhile, the assay also showed that TGF beta 1 could inhibit the mRNA expression of c-myc, EGFR and TGF beta 1 genes in cells. CONCLUSIONS: TGF beta 1 can not only act as an autocrine to inhibit cell proliferation, but also trigger PCD in HO-8910 cells. These functions may be fulfilled through some specific signal transduction pathways.

Apoptosis↗
PubMed1998

[Experimental study of Yishou tiaozhi tablet on inhibiting hyperlipemia and atherosclerosis].

OBJECTIVE: To observe the effect of Yishou Tiaozhi tablet on lipid-metabolism and aortic intimal atherosclerotic plaque coverage in rabbit's model of experimental hyperlipemia and atherosclerosis. METHODS: Thirty-two rabbits were divided randomly into four groups, group A, B, C and D, 8 in each group. Forage with cholesterol and lipid plus 1.59 g/kg of Yishou Tiaozhi tablet was fed to the group A every day; to the group B, 22.54 mg/kg gypenoside tablet was added to forage with cholesterol and lipid; to the group C, forage with cholesterol and lipid was fed; and to the group D, ordinary forage only. Biochemical parameters were measured and pathomorphological examination were carried out 6 weeks later. RESULTS: (1) Yishou Tiaozhi tablet obviously lowered the levels of serum TC, TG, AI, ApoB, LP (a), ox-LDL, HYP, plasma Ca2+, TXB2 and increased the levels of serum HDL-ch, ApoA1, ApoA1/APoB, plasma 6-keto-PGF1 alpha(P < 0.01). (2) Pathomorphological examination showed that in the group A aortic intimal atherosclerotic plaque area and arterial intima thickness obviously reduced, smooth muscle cell hyperplasia and elastic fibers were not seen. CONCLUSION: Yishou Tiaozhi tablet can inhibit experimental hyperlipemia and atherogenesis. It is an ideal and effective medicine in preventing and treating hyperlipemia and atherosclerosis.

Animals↗
PubMed1998

[Observation on sleep improvement under noise environment by wearing earplugs].

Sleep experiments were done in 6 subjects under 3 conditions. (1) Quiet, background noise level lower than 45dB (A); (2) Noisy with earplugs, ambient noise level 90dB (A); (3) Noisy, ambient noise level 90dB (A), and subjects wearing earplugs. EEG, REM and EMG during sleep were recorded. Sleep latency, times and duration of waking up, sleep rate of each stage and total sleep rate were analyzed. It shows that sleep under noise condition can be improved by wearing earplugs.

Adult↗
PubMed1998

[Diagnostic significance of cuticular patterns on corolla surface from Pueraria spp].

OBJECTIVE: To provide reference materials for the classification and identification of Pueraria spp. by studying the cuticular patterns on corolla surface. METHOD: The cuticular patterns of corolla were observed under SEM (scanning electron microscope). RESULT: The species of the genus Pueraria are defferent from each other in cuticular patterns. CONCLUSION: The diagnostic characters of the cuticular patterns on corolla surface can be used for the classification and identification of Pueraria spp.

Fabaceae↗
PubMed1998

[Human interleukin-13 cDNA cloning and expression].

OBJECTIVE: To construct an efficient expression system for HIL-13 in prokaryotic cells. METHODS: After Amplified by RT-PCR, The cDNA fragment encoding HIL-13 was inserted into pGEX-2T plasmid and expressed under induced condition. RESULTS: HIL-13 cDNA was obtained. Recombinant plasmid pGEX-2T HIL-13 was constructed and sequenced, the inserted fragment of the recombinant plasmid was confirmed to be HIL-13 cDNA. HIL-13 was expressed as a fusion protein with glutathione-s-transferase (GST-HIL-13, MW = 39,000). CONCLUSIONS: (1) HIL-13 cDNA has been obtained from T lymphocytes. (2) The rate of expression of HIL-13 in prokaryotic cells is about 37%.

Amino Acid Sequence↗
PubMed1998

[Studies on developmental enamel defects in the primary dentition of children with histories of low birth weight and prematurity and their susceptibility to dental caries].

OBJECTIVE: From the clinical and experimental aspects, to study the susceptibility of dental enamel defects to dental caries in the primary dentition. METHODS: One hundred and seventy-six children (aged 3-8) with histories of low birth weight and premature birth were studied about the relationship of dental enamel defect to caries. Four exfoliated hypoplastic anterior deciduous teeth were studied about the solubility of dental enamel in order to compare the solubility of the defective enamel with that of the normal enamel in the same teeth. RESULTS: The prevalence of both enamel opacity and enamel hypoplasia was significantly interrelated to prevalence of dental caries in those particular teeth. The solubility of the hypoplastic enamel powder was higher than that of the normal enamel in the same teeth. It took shorter time for the hypoplastic enamel powder to attain an equilibrium than the normal did. CONCLUSION: The defective enamel was much easier attacked by caries.

Birth Weight↗
PubMed1998

[Study on human eye ciliary muscule cell culture and biologic characteristics].

PURPOSE: We cultured human ciliary muscle [HCM] cells to study their growth, ultrastructure, immunohistochemistry and functional characters. METHODS: HCM cells from 10 young donor eyes were cultured with collagenase IV digestion procedures in vitro, the cells were identified by eletronmicroscope and immunohistochemistry assay, their function were studied by single-cell-contraction assay. RESULTS: The cells were passed and grew in Hill-Valley pattern after conflunet; abundant filaments were presented under electronmicroscope. In Desmin protein immunohistochemistry study, the cultured cells were stained positive; in tissue sections, HCM cells stained positive, vascular smooth muscle stained positive weakly, but fibroblast cells and endothelial cells stained negative. 10(-3) M Carbachol could induce the cultured cells contract, this effect was antagonized by 10(-3) M Atropine. CONCLUSION: We successfully cultured HCM cells, which were able to contract.

Cells, Cultured↗
PubMed1997

Identification and characterization of a novel plant phospholipase D that requires polyphosphoinositides and submicromolar calcium for activity in Arabidopsis.

Phospholipase D (PLD; EC 3.1.4.4) has been proposed to be involved in a number of cellular processes including transmembrane signaling and membrane deterioration. PLD previously described from various plant sources generally requires millimolar ranges of calcium for optimal activity. In this study, we genetically suppressed the expression of this conventional PLD in Arabidopsis by introducing an antisense PLD cDNA. However, both the antisense transgenic and wild-type plants showed comparable PLD activity in the presence of submicromolar concentrations of calcium and phosphatidylinositol 4, 5-bisphosphate using phosphatidylcholine as a substrate. This new PLD activity was partially stimulated by phosphatidylinositol 4-phosphate, but not by other phospholipids, including phosphatidylinositol, phosphatidylserine, phosphatidylglycerol, phosphatidic acid, or phosphatidylcholine. Its requirement for polyphosphoinositides was further supported by its ability to be inhibited by neomycin. The polyphosphoinositide-dependent PLD requires calcium for activity, but no magnesium. The calcium stimulation was observed in the nanomolar range and reached a plateau at 5 microM calcium. The findings of this study demonstrate the presence of different PLDs that are regulated in a distinct manner in plants. The potential significance of a PLD that is regulated by polyphosphoinositides and physiological concentrations of Ca2+ is discussed.

Arabidopsis↗
PubMed1997

Studies of a second family with the Quebec platelet disorder: evidence that the degradation of the alpha-granule membrane and its soluble contents are not secondary to a defect in targeting proteins to alpha-granules.

We recently described a Quebec family with an autosomal dominant bleeding disorder characterized by mildly reduced-low normal platelet counts, an epinephrine aggregation defect, multimerin deficiency, and proteolytic degradation of several, soluble alpha-granular proteins. Similar clinical features led us to investigate a second family with an unexplained, autosomal dominant bleeding disorder. The affected individuals had reduced to normal platelet counts, absent platelet aggregation with epinephrine, and multimerin deficiency. Their platelet alpha-granular proteins factor V, thrombospondin, von Willebrand factor, fibrinogen, fibronectin, osteonectin, and P-selectin were proteolyzed and comigrated with the degradation products found in patients from the other family. However, their platelet albumin, IgG, external membrane glycoproteins, CD63 (a lysosomal and dense granular protein), calpain, and plasma von Willebrand factor were normal, indicating restriction in the proteins proteolyzed. Electron microscopy studies indicated preserved alpha-granular ultrastructure, despite degradation of soluble and membrane alpha-granular proteins. Immunoelectron microscopy studies of the patients' platelets indicated that fibrinogen, von Willebrand factor, P-selectin, multimerin, and factor V were within alpha-granules, with normal to reduced labeling for these proteins. Pathologic proteolysis of alpha-granular contents, rather than a defect in targeting proteins to alpha-granules, may be the cause of the protein degradation in the Quebec platelet disorder.

Adult↗
PubMed1997

Mucosal protection from intestinal ischemia-reperfusion reduces oxidant injury to the lung.

The authors investigated whether amelioration of intestinal mucosal injury, due to ischemia-reperfusion (I/R), with oxygenated perfluorocarbon (PFC) would reduce an oxidant-generated lung injury. The small intestine is increasingly recognized as a primary effector of distant organ injury. Clinical and experimental studies suggest oxidant species and activated neutrophils as the agents responsible for lung injury after intestinal I/R. The role of intestinal mucosal injury has not been defined. Oxygenated PFC was perfused through the lumen of the intestine during periods of I/R. Portal venous effluent was examined for reactive oxygen species and lung tissue was examined for lipid peroxidation. Luminal perfusion of oxygenated PFC during intestinal I/R reduced oxidant species in the portal blood. This correlated with a reduction in lung lipid peroxidation. Oxygenated PFC prevented intestinal mucosal injury resulting from induced I/R. Amelioration of mucosal injury reduced oxidant generation in the portal venous circulation that was proportional to the reduction in measured lung injury. Protection of the mucosa with intraluminal oxygen may prevent I/R-associated lung injury.

Animals↗
PubMed1997

Characterization of colorectal-cancer-related cDNA clones obtained by subtractive hybridization screening.

In an attempt to seek out new factors that are related to colorectal carcinogenesis at the molecular level, subtractive hybridization between cDNA of normal mucosal tissues and mRNA of colorectal carcinoma tissues was performed. Subsequent screenings of the cDNA libraries, constructed from normal mucosal tissues, using the "subtractive probes" generated a total of 46 clones that were expressed in normal mucosa but were either expressed at a significantly reduced level or not expressed at all in cancer tissues. Partial nucleotide sequences of all of these cDNA clones were determined, and sequence homology analyses were performed with the Genbank database. Of the 46 cDNA samples, 44 contained substantial sequence homologies with 32 immunoglobulin gene fragments, a helix-loop-helix basic phosphoprotein gene, an acidic ribosomal phosphoprotein P2 gene, a BLR1 gene for Burkitt's lymphoma receptor 1 gene, D5S419 DNA segment containing (C-A) repeats, a glucokinase (GCK) gene, a Na+, K+-ATPase alpha-subunit gene, a histocompatibility system HLA-DR heavy-chain gene, a dystrophic gene, a mucin (MUC2) gene, a mu-glutathione S-transferase gene, a Menkes disease protein gene, and a 40-kDa keratin intermediate filament precursor gene. The remaining two cDNA clones (now registered under GenBank accession numbers U17714 and U20428) showed few (less than 60%) sequence homologies with any known sequences in the GenBank database and, therefore, may represent novel genes whose expression was down-regulated in human colorectal carcinomas. The possible clinical significance of these findings and the involvement of these two genes in the carcinogenesis of colorectal as well as other cancers are being investigated.

Base Sequence↗
PubMed1997

The relationship between 67KD laminin receptor expression and metastasis of hepatocellular carcinoma.

The 67KD laminin receptor (LN-R) that binds laminin (LN) is involved in the metastasis cascade. Using immunohistochemical technique, in situ hybridization and reverse transcription polymerase chain reaction (RT-PCR), we studied LN-R protein and RNA levels in 30 cases of human hepatocellular carcinoma (HCC) to further understand its role in the metastasis of HCC. In our 14 cases of HCC with metastasis, its positive rates were 71.4%, 57.1%, 85.7% respectively, whereas its positive expression in 16 cases without metastasis were 31.3%, 18.8%, 50.0% respectively. The significant difference was found between these two groups. The results suggest that the 67KD LN-R expression plays a very important role in the metastasis of HCC.

Basement Membrane↗
PubMed1997

Oxygenated intraluminal perfluorocarbon protects intestinal muscosa from ischemia/reperfusion injury.

Ischemia/reperfusion (I/R) injury to the intestinal mucosa occurs in several commonly encountered clinical situations, such as necrotizing enterocolitis and nonocclusive mesenteric insufficiency. No clinically feasible technique is available for mucosal preservation during ischemia. The goal of this work was to determine whether the continuous intraluminal flow of oxygenated perfluorocarbon (PFC) could protect mucosal integrity and function in a rat model of intestinal I/R injury. Rats were subjected to ischemia by clipping the superior mesenteric artery (SMA) for 60 minutes. Reperfusion was achieved by release of the clip for 120 minutes. Animals were divided into 4 groups: Sham (laparotomy alone), I/R (I/R alone), I + PFC/R (PFC was administered during the ischemic interval only), I/R + PFC (PFC was delivered only during reperfusion). Tissue sections were examined blindly to assess mucosal integrity, and mucosal dissacharidase activities were measured to assess function. Oxygenated PFC, when administered during ischemia alone, ameliorated I/R-induced mucosal injury; however, when it was delivered during reperfusion alone, the mucosal injury worsened. When oxygenated PFC was administered throughout I/R, the degree of mucosal injury was similar to the I + PFC/R group, and dissacharidase activities were preserved when compared with the I/R group. Intraluminal perfusion of oxygenated PFC during ischemia preserves mucosal function and integrity, and may offer a new treatment modality for a variety of mesenteric ischemic disorders.

Animals↗