Biomedical subjects

H Wang

Publications and source records attributed to H Wang.

At least 1,441 records · Page 80Linked to original sources

PubMed1998

An experimental study on rhBMP-2 composite bone substitute for repairing craniomaxillary bone defects.

OBJECTIVE: To measure bone regenerative effects in animal calvarial or mandibular critical-size defects using recombinant human bone morphogenetic protein-2 (rhBMP-2) combined with four selected carriers. MATERIALS AND METHODS: The composite bone grafts were obtained by combining rhBMP-2 with chitin, coral, coral-based porous HA (CHA), and xenogeneic cancellous bone, respectively. These materials were implanted on the calvarial or mandibular defect of rabbits and on the calvarial defect of rats. Each carrier material was also studied as a control group. The animals were examined 2, 4, 8, and 12 weeks after implantation by radiography, histology (under light microscope and scanning electron microscope), immunohistochemistry, and biomechanics. RESULTS: The results showed that the composite graft was absorbed gradually after it was implanted into the defect, during which time new bone was formed within the combined material in the defect site; the amount of new bone increased as time elapsed. At 12 weeks the composite was replaced completely by bone except in the CHA group. In contrast, a large amount of fibrous tissue, and little new bone, formed on the area of the bone defect when the carrier material alone was implanted. CONCLUSIONS: All materials tested seem to be suitable carriers for rhBMP-2, which plays a very important role in new bone formation. These composite bone substitutes may be ideal materials for repairing various bone defects in the craniomaxillofacial region.

Animals↗

PubMed1998

Study on hydroxyapatite-coated titanium implants used as orthodontic anchorage--an experimental investigation of implant stability and peri-implant neck tissue in dogs.

OBJECTIVE: Hydroxyapatite-coated titanium endosseous implants as orthodontic anchorage were studied. METHODS: These implants, installed in the mandibles of two dogs, were loaded with the orthodontic force of 150 g for 3 months. The stability of the implant and peri-implant neck tissue were investigated with radiograph and index evaluation. RESULTS: No implants were mobile, loosened or dislocated at the 3-month follow-up. The soft tissue around the cervical part of the implants had slight inflammation because of poor oral hygiene and stimulation of residual foods attached to the stainless steel spring. However, no resorption of marginal alveolar bone was found under sustained orthodontic force. CONCLUSIONS: The HA-coated titanium implant can be used as anchorage for short-term orthodontic treatment.

Alveolar Bone Loss↗

PubMed1998

Saccharides as osmotic agents in peritoneal dialysate: determination of molecular weight essential for more efficient fluid removal.

Glucose has widely been used as an osmotic agent in continuous ambulatory peritoneal dialysis (CAPD) but owing to its low molecular weight (MW), ultrafiltration (UF) in a 6-hour dialysate exchange does not appear sufficient. Thus, in the present study, a search was made to find saccharides that would ensure optimal UF, exceeding that obtained with glucose in a 6-hour dwell period. Rats were intraperitoneally infused with peritoneal dialysate (20 mL/body) containing the same molar concentrations (75.5 mM, 126 mM, or 204 mM) of various osmotic agents including glucose (monosaccharide, MW = 180.16) at concentrations of 1.36%, 2.27%, and 3.86%; maltose (disaccharide, MW = 342.30) at concentrations of 2.58% and 4.32%; maltotriose (trisaccharide, MW = 504.44), at concentrations of 3.81% and 6.36%; and maltopentaose (pentasaccharide, MW = 828.72) at concentrations of 6.26% and 10.4%. Intraperitoneal-fluid volume was measured at 1, 2, 3, 4, and 6 hours. With glucose as the osmotic agent, maximal UF was noted at 2 to 4 hours. UF was more efficient at 6 hours with maltotriose or maltopentaose as the osmotic agent. Even with a trisaccharide or pentasaccharide (molecular weights of 500 to 830), UF at 6 hours was found more efficient, as evidenced by the delay in peritoneal absorption. Fluid removal in 6 hours should be greater when using a dialysate containing oligosaccharides such as maltotriose or maltopentaose in place of glucose.

Animals↗

PubMed1998

In vitro and in vivo generation and kinetics of glycosylation products in peritoneal dialysis effluents.

There are indications that advanced glycosylation end-products (AGEs) may affect in some manner the functions of the peritoneum. Only a few reports discuss the actual generation of glycosylated proteins and the intraperitoneal kinetics involved during continuous ambulatory peritoneal dialysis (CAPD). To demonstrate the formation of AGEs and their time-courses in peritoneal dialysis (PD) effluents, measurements were made of furosine, carboxymethyl lysine (CML), and pentosidine as glycosylation markers in vitro and in vivo using PD effluents obtained every 2 hours for up to 8 hours from 3 nondiabetic CAPD patients. Furosine and CML were found to be generated relatively early (within 6 hours), and their de novo formation was markedly enhanced subsequent to glucose addition. Furosine and CML production increased in proportion to glucose concentration. Pentosidine production did not change with time for up to 24 hours, and was not induced by glucose during this period. Carboxymethyl lysine production appeared to be suppressed in vitro with the addition of serum protein. Furosine in the intraperitoneal dialysate was initially the same as that in the plasma, but increased to twice as much in just 2 hours in vivo. Production of CML increased, but apparently was suppressed with leakage of plasma protein into the dialysate; this possibly may have been due to dilutional or antiglycation effects in the plasma. No stimulation of pentosidine production could be detected in the intraperitoneal dialysate even at 8 hours. The initiation of glycosylation of peritoneal proteins, with generation of furosine and CML but not pentosidine, is clearly shown by the present results to occur relatively early in the intraperitoneal dialysate, i.e., within a matter of hours.

Adult↗

PubMed1998

[Alteration of peritoneal lymphocyte transformation and its interleukin-2 release in patients with infertility and endometriosis].

OBJECTIVE: To study the relationship between alteration of peritoneal lymphocyte transformation activity, its interleukin-2 (IL-2) release and infertility associated with endometriosis. METHODS: Peritoneal fluid was collected from 15 infertile patients with endometriosis (endometriosis group) and 13 normal fertile women (control group). Lymphocyte transformation activity were determined in peritoneal fluid by morphometry. IL-2 contents were determined in peritoneal fluid and supernatants of cultured pelvic lymphocytes by biological method. RESULTS: Lymphocyte transformation activity reinforced (P < 0.001) and IL-2 contents increased in peritoneal fluid and supernatant of cultured pelvic lymphocyte in the endometriosis group than those in the control group (P < 0.01, P < 0.001 respectively). There is significant positive correlation between lymphocyte transformation rate and IL-2 activity of cultured supernatant in endometriosis group (P < 0.001). CONCLUSION: The increase of IL-2 content in the samples of endometriosis may play an important role in infertility with endometriosis.

Adult↗

PubMed1998

[Effects of static magnetic fields on free radical metabolism of human body].

The effects of static magnetic fields at 150 to 155 mT on the activities of superoxide dismutase (SOD) and the contents of maglonydiadehyde (MDA) in the serum and the activities of glutathione peroxidase (GSH-Px) in the whole blood were observed in the healthy volunteers. The results showed that the activities of SOD and GSH-Px were significantly increased, and the content of MDA was significantly decreased in short term at the observed magnitude of static magnetic fields. The results suggest that the function of the free radical metabolism of human body could be improved by static magnetic fields at that magnitude.

Adolescent↗

PubMed1998

[The combined effects of MCYST and water organic pollutants on the co-induction of SHE cell transformation and expression of Ras P21 protein].

The authors studied the combined carcinogenic activities of MCYST and organic pollutants in water of Dianshan Lake, using in vitro Syrian hamster embryo (SHE) cell transformation and immunohistochemical assays. The results showed that MCYST alone could not induce SHE cell transformation, but it increased the effects of low dose organic pollutants in cell transformation in a dose-dependent manner. In the cells isolated from type II transformed foci, ras P21 protein showed a positive immunohistochemical staining. It suggests MCYST may be a tumor promoter, which has a synergistic carcinogenic activity organic pollutants in water and the activation of ras oncogene may be one of the factors inducing malignant transformation.

Animals↗

PubMed1998

[HA-coated titanium implants used as orthodontic anchorage. An experimental investigation of implant stability and peri-implant neck tissue in dogs].

This study was aimed at the feasibility of using HA-coated titanium endosseous implants as orthodontic anchorage. These implants installed in dog's mandibles were loaded with the orthodontic force of 150 g for 3 months. The stability of the implant and the peri-implant neck tissue were investigated with radiograph and index evaluation. The findings demonstrated that no implant was mobile or loose or dislocated. The soft tissue around the cervical part of the implants had a slight inflammation because of bad oral hygiene and the stimulation of residual food attached to the stainless string. However, no resorption of marginal alveolor bone was found under sustained orthodontic force. The above results suggest that the HA-coated titianium implant can be used as anchorage for short-term orthodontic treatment.

Animals↗

PubMed1998

[Effects of mifepristone on ICE expression and Fas expression in early pregnant chorionic villi].

This study addressed the question whether mifepristone has any effect on apoptosis in early pregnant chorionic villi. Interleukin 1 beta converting enzyme(ICE) expression and Fas expression in early pregnant villi and their changes following mifepristone administration were detected by immunohistochmical method and computer image analysis. During early pregnancy, ICE and Fas were expressed in all component chorionic cells, predominantly syncytiotrophoblasts. ICE stained cytoplasma. Fas stained mainly cytoplasma, and in partial trophoblastic cells, Fas was expressed on membrane and nucleus. In the villi from the pregnant women who received mifepristone for 2 days, expression of Fas increased markely; the ratio of positive nuclear staining cells were significantly raised, but the immunostaining intensity of ICE was slightly increased. These results suggest that mifepristone may terminate early pregnancy via increasing the expression of Fas and promoting apoptosis in the chorionic villi.

Abortifacient Agents, Steroidal↗

PubMed1998

[Improving the bonding strength of castable ceramic crowns].

To study the influence of bonding agent on fracture strength of Plat-II castable ceramic crowns bonded to molars, we tested the specimens in vitro with Panavia 21 resin bonding agent and porcelite dual cure cement. The results showed that the fracture loading (845.8 +/- 137.1 N) of crowns bonded with Panavia 21 bonding agent was higher than that (534.0 +/- 58.7 N) of crows bonded with porcelite dual cure cement. The difference between the two agents was statistically significant (P < 0.05). The crowns bonded with Panavia 21 agent had higher strength than bite forces. These suggest that costable ceramic crowns could be bonded with Panavia 21 resin agent in clinical practice.

Crowns↗

PubMed1998

[MMC conditioning regimen (Melphalan, MeCCNU and cyclophosphamide) followed by allogeneic peripheral blood stem cells transplantation for chronic myeloid leukemia].

This paper reports 3 cases of allogeneic peripheral blood stem cell transplantation (Allo-PBSCT) for the patients with chronic myeloid leukemia (CML). The patients received MMC preparative regimen with high dose chemotherapy (Melphalan 170 mg/m2, p.o. on Day-5, MeCCNU 400 mg/m2, p.o. on Day-4, and Cyclophosphomide 60 mg/kg/day, i.v. on Days-3 and -2). The HLA-identical sibling donors received filgrastim (rhG-CSF) for mobilization at a dose of 300 micrograms/day for 6 days. Leukaphereses were done at the 6th day of mobilization. A median of 8000 ml (2 times total blood volume) of blood was processed the collecting: 2.5-4.5 x 10(8)/kg MNC, 12.8-20.0 x 10(6)/kg CD34+ cells (including 4.8-7.5 x 10(6)/kg CD34+CD33-, 8.0-13.0 x 10(6)/kg CD34+CD33+), and 3.5-4.3 x 10(5)/kg CFU-GM. Cyclosporin A and methotrexate were used for GVHD prophylaxis. Hematopoitic function recovered as for 14-20 days to > 0.5 x 10(9)/L of neutrophil count, and for 16-34 days to > 20 x 10(9)/L of platelet count. At day + 100, chromosome analysis of bone marrow cells showed that complete chimera without ph1 positive chromosome in Cases 1 and 3, and a partial chimera with 73% donor karyotype in Case 2. All patients now are in disease free survival. No episode of acute graft versus host disease (GVHD) developed. It was concluded that HLA matched sibling allogeneic PBSCT result in rapid hematopoitic reconstitution and the MMC conditioning regimen is effective both in leukemic cells eradication and in immunosuppression for stem cells engraftment, and the drug related toxicity could be tolerated by patients.

Adult↗

PubMed1998

Field activity cost estimates for the first 3 years of the World Bank Loan Project for schistosomiasis control in China.

The World Bank Loan Project for schistosomiasis in China commenced field activities in 1992. In this paper, we describe disease control strategies for levels of different endemicity, and estimate unit costs and total expenditure of screening, treatment (cattle and humans) and snail control for 8 provinces where Schistosoma japonicum infection is endemic. Overall, we estimate that more than 21 million US dollars were spent on field activities during the first three years of the project. Mollusciciding (43% of the total expenditure) and screening (28% of the total) are estimated to have the most expensive field activities. However, despite the expense of screening, a simple model predicts that selective chemotherapy could have been cheaper than mass chemotherapy in areas where infection prevalence was higher than 15%, which was the threshold for mass chemotherapy intervention. It is concluded that considerable cost savings could be made in the future by narrowing the scope of snail control activities, redefining the threshold infection prevalence for mass chemotherapy, defining smaller administrative units, and developing rapid assessment tools.

Animals↗

PubMed1998

[The effect of 25 micrograms misoprostol on induction of labor in late pregnancy].

OBJECTIVE: To determine the efficacy and safety of 25 micrograms misoprostol for labor induction in the third trimester of pregnancy. METHODS: 48 term pregnant women with single pregnant vertex present intact membrane were selected in study group. All case in study group indications for labor induction, without contra-indication of labor induction and misoprostol. The 48 women were randomly assigned A(25 micrograms) and B(50 micrograms) misoprostol groups. Misoprostol was placed in the posterior vaginal fornix every 4 to 6 hours. The maximum dose in 24 hours is 200 micrograms. Misoprostol was not given after either spontaneous rupture of membrane or beginning of active labor. RESULT: The sucesess rate of induction labor was groups 77.8%, 81.0% in group A and B, respectively. The average duration from administration of misoprostol to start of labor in two groups was 796.9 +/- 359.9 minutes and 807.4 +/- 405.2 minutes, respectively; the average duration from start of misoprostol use to vaginal delivery was 978.6 +/- 464.4 minutes, 977.5 +/- 421.4 minutes, respectively. The incidence of vaginal delivery had no statistics significant difference between two groups (P > 0.05). The incidence of hypertonic uterine contraction or hypertonic contractionchysystole with abnormal pattern of fetal monitoring in group A was lower than that of group B, but there was no significant difference (P > 0.05). CONCLUSION: 25 micrograms misoprostol is an efficient and safe dosage for labor induction in term pregnancy.

Adult↗

PubMed1998

[Effect of EBV latent membrane protein 1 gene isolated from human nasopharyngeal carcinoma cell line SUNE on the growth of immortalized epithelial cells].

OBJECTIVE: To study the effect of EBV latent membrane protein (LMP1) gene isolated from human nasopharyngeal carcinoma cell line SUNE on the growth of epithelial cells and the role of LMP1 in the genesis of nasopharyngeal carcinomas. METHODS: EBV LMP1 gene eukaryotic expression plasmid was transfected into human embryo kideney epitheial cells. Expression of LMP1 protein in the transfected cells was detected. Dynamic cell growth status, growth rate, ability of colony formation in soft agar and the tumorigenicity of the transfected cells in nude mice were studied. RESULTS: The LMP1 gene transfected cells grew vigorously and rapidly, lost contact inhibition, formed more colonies in soft agar, developed tumors in nude mice. CONCLUSION: LMP1 gene could alter the biological behaviours of epithelial cells, promote cell proliferation and transformation, and endows the transfected cells with growth characteristics like tumor cells.

Animals↗

PubMed1998

[Expression of signal-regulatory protein alpha (SIRP alpha) in hepatocellular carcinoma].

OBJECTIVE: To investigate the association between signal-regulatory protein alpha (SIRP alpha) and hepatocellular carcinoma (HCC). METHODS: Thirty-six pairs of HCC and the surrounding noncancerous hepatic tissues, one normal liver cell line and 4 HCC cell lines were used to extract the total RNA and then to prepare the mRNA. The expression of SIRP alpha was determined by Northern blot analysis. The results were analyzed in association with the pathologic characteristics of each sample. RESULTS: SIRP alpha expressed at low level in 20 of 36 HCC samples and 2 of 4 HCC cell lines. Of the two major hybridization signals, a 3.9 kb transcript in HCC samples was 2-4 times lower than that in the surrounding noncancerous hepatic tissues, whereas a 2.5 kb transcript was 4-6 times as low. Furthermore, a hybridization signal slightly longer than 3.9 kb, being absent in the surrounding noncancerous hepatic tissue, appeared in 9 of the 20 HCC samples. Low level expression of SIRP alpha was observed in all of the 5 HCC samples that had intrahepatic or portal metastasis. CONCLUSION: The expression of SIRP alpha, especially 2.5 kb transcript, was down-regulated in HCC, and an unknown mumber or a variant of SIRP family existed in some tumor tissues. SIRP alpha protein may play an important role in hepatic oncogenesis and metastasis of HCC.

Antigens, Differentiation↗

PubMed1998

[Regulative effect of nuclear factor kappa B on the expression of intercellular adhesion molecular-1 in human mesangial cells].

OBJECTIVE: To study the regulative effect of nuclear factor kappa B (NF-kappa B) on the expression of intercellular adhesion molecular-1(ICAM-1) in human mesangial cells (HMC) by interleukin I-1 beta (IL-1 beta). METHODS: Activation of NF-kappa B was measured by electrophoresis mobility shift assay (EMSA). ICAM-1 expression was detected by Northern Blot and Cell ELISA. RESULTS: rhIL-1 beta (10 ng/ml) could rapidly stimulate activation and translocation of NF-kappa B, and also could enhance the expression of ICAM-1 in mRNA (0.14 vs 0.35) and protein (0.92 +/- 0.10 vs 1.35 +/- 0.11, P < 0.01) level. After pretreatment with 100 mumol/L L-1-chlor-3-(4-tosylamido)-4-phenyl-2 butanon (TPCK), an inhibitor of NF-kappa B, both ICAM-1 levels of mRNA and protein stimulated by rhIL-1 beta were blocked by about 50% in these cells (0.46 +/- 0.05 vs 1.29 +/- 0.12, P < 0.01) compared with the rhIL-1 beta-stimulated group. CONCLUSION: These results suggest that NF-kappa B is one of the signaling factors for IL-1-stimulated ICAM-1 expression in HMC. It may modulate the immune-inflammatory process in glomerular diseases.

Glomerular Mesangium↗

PubMed1998

[Antisense to cyclin D1 inhibits the proliferation of glomerular mesangial cells].

OBJECTIVES: To investigate the role of Cyclin D1 in the proliferation of glomerular mesangial cells. METHODS: We first detected the expression of Cyclin D1 protein in mesangial cells by using immunohistochemical method, set up a retroviral vector mediated genetransfer system expressing Cyclin D1 antisense RNA with recombinating techniques, and assay the proliferating situation of genetransferred mesangial cells by MTT method and flow cytometry respectively. RESULTS: Cyclin D1 protein was expressed in the nuclei of cultured mesangial cells in vitro. The exgoenous gene was transducted into mesangial cells mediated by retrovirus and transcripted and expressed antisense RNA in high effiency. The response of antisense Cyclin D1 genetransferred mesangial cells to Endothelin-1 (OD570)(18 hr 0.105 +/- 0.009 vs 6 hr 0.096 +/- 0.013) was not significant (P > 0.05), but normal cells (18 hr 0.259 +/- 0.080 vs 6 hr 0.100 +/- 0.007) and only vector transferred cells (18 hr 0.278 +/- 0.020 vs 6 hr 0.097 +/- 0.008) were significant (P < 0.01). The progression of cell cycle was prevented from G1 to S phase by antisense Cyclin D1, and the percentage of cells of S phase in antisense Cyclin D1 genetransferred cells (12.70 +/- 3.39) was significantly reduced (P < 0.01) as compared with normal cells (29.98 +/- 3.26). CONCLUSIONS: Cyclin D1 is a key regulatory protein of G1 progressing of cell cycle of mesangial cells, and the cellular proliferation stimulated by Endothelin-1 can be suppressed prominently in antisense Cyclin D1 gene transducted mesangial cells.

Animals↗

PubMed1998

[Sulfonylurea receptor gene polymorphism is associated with non-insulin dependent diabetes mellitus in Chinese population].

OBJECTIVE: To test the role of Sulfonylurea receptor gene(SUR) in the pathogenesis of NIDDM in Chinese population. METHODS: We studied the polymorphisms of the SUR gene in intron 24 and exon 22 by polymerase chain reaction(PCR) and appropriate restriction enzyme (PCR-RFLP) in 86 NIDDM patients with at least two first degree diabetic relatives and 148 normal control subjects. RESULTS: The frequency of "c" allele of intron 24 in NIDDM patients was significantly increased as compared with that in the control subjects (68.02% vs. 55.41, P = 0.007), and the frequency of the "cc" genotype of intron 24 in the NIDDM group was also significantly higher than that in the control group (41.86% vs. 27.7%, P = 0.013, OR = 4.39, CI: 1.52-12.66). The polymorphism of exon 22 described in the Caucasian population was not detected. CONCLUSION: The association of the polymorphism of SUR gene with NIDDM in different races suggests that the SUR gene or nearby gene may play an important role in the genetic susceptibility of NIDDM.

ATP-Binding Cassette Transporters↗