Biomedical subjects

H Wang

Publications and source records attributed to H Wang.

At least 919 records · Page 51Linked to original sources

PubMed2000

[An experimental investigation between osseointegration and stability of implants used as orthodontic anchorage in dogs].

OBJECTIVE: To investigate the relation between osseointegration and stability of three kinds of implants used as orthodontic anchorage in dogs. METHODS: HA-coated, titanium coated, and uncoated titanium implants were inserted into each femur of two dogs. After heal period of three months, the orthodontic force of 200 g was applied by means of Ni-Ti springs, which were connected to the two adjacent implants, for two months. The position change of implants was measured and calculated. The shear bond strength of interface between implant and bone was measured with push-test. The interface was observed with scanning electronic microscope. RESULTS: The distance changes of HA-coated, T-coated and uncoated groups were (-0.50 +/- 1.78) mm, (-0.05 +/- 1.76) mm and (0.29 +/- 1.77) mm, respectively, which showed no statistical difference. The shear strength values were (2.88 +/- 0.55) MPa, (1.89 +/- 0.81) MPa and (2.14 +/- 0.49) MPa, respectively. HA-coated implant contacted with bone closely and the bond strength was the highest. The other two implants were found no significant difference in bond strength. CONCLUSION: The osseointegration was found at the interface among all three kinds of implants and bone and no displacement was found during application of clinical orthodontic force.

Animals↗

PubMed2000

[The role of bcl-2 and bax genes and programmed cell death in the temporomandibular joint development].

OBJECTIVE: To evaluate the roles of bcl-2, bax gene and programmed cell death(PCD) in the TMJ development. METHODS: PCD, expression of both mRNA and protein of bcl-2 and expression of bax protein were observed by Tdt-mediated dUIP nick end labeling (TUNEL), mRNA in situ hybridization and immunohistochemical staining in TMJ of SD rats during series prenatal and postnatal developmental periods. RESULTS: PCD was involved in condylar cartilage in development of different periods. The cells of PCD were mainly located in proliferative zone and the area between prehypertrophic zone and late hypertrophic zone. bcl-2mRNA was expressed with high levels in proliferative and prehypertrophic zones and very few matured chondrocytes expressed bcl-2. The expression of bcl-2 protein showed the same distribution as bcl-2mRNA, but gradually decreased in late hypertrophic zone, compared with strong expression of Bax throughout condylar cartilage. CONCLUSIONS: PCD of condylar cartilage is regulated by bcl-2 and bax gene, the number and site of PCD are attributed to the change of bcl-2 and bax gene, and bcl-2 is an important gene in maintaining survival of chondrocytes during the proliferation, differentiation and maturation.

Animals↗

PubMed2000

[An analysis on need and demand for dental service in urban residents of Beijing].

OBJECTIVE: To analyze the needs and demands for dental services in urban residents of Beijing, and to forecast developmental trends of dental demand in the future. METHODS: There were 1,517 subjects examined by a stratified, clustering, random sampling, and a questionnaire survey were completed. RESULTS: The prevalence of oral diseases was 97.6%, but only 31.5% of subjects visited the dentist in a year, the total number of residents who had need of dental care were 4,412,010 more than that of demand level. Potential demand was mainly due to the negative awareness of people and problem from service provider. It was predicted that, if the potential demand caused by awareness and service provider were satisfied, the demand for dental care would increase by 69.4% and 13.2%, respectively. By the year of 2005, the demand will increase by 1.14%, and the value will be 3.76% in 2010. CONCLUSIONS: A substantial discrepancy is found between oral disease presence and demand for dental service. The levels of demand are also irrational. The large potential demand is caused by both receiver and provider's factors. At last, the future demand for dental care is forecasted under three hypothesis.

China↗

PubMed2000

[Effects of shuanglong pill on mRNA expression of platelet-derived growth factor A and monocyte chemoattractant protein-1 mRNA].

OBJECTIVE: To explore the molecular mechanism of Shuanglong Pill (SLP) in intervening atherosclerosis, mainly the effect of SLP on the mRNA expression of the platelet-derived growth factor-A (PDGF-A) and the monocyte chemoattractant protein-1 (MCP-1). METHODS: Using the hyperlipoprotein serum (HLS) of cultured rabbits' aortic smooth muscle cell (SMC) to build the atherosclerotic cell model, and medicated serum acting on the cell model by serum pharmacologic method. The effect of SLP medicated serum on the level of PDGF-A, MCP-1 mRNA expression were observed and analysed by means of reverse transcriptase-polymerase chain reaction assay. RESULTS: It was found that HLS stimulated mRNA expression of the PDGF-A and the MCP-1, but the medicated serum of SLP lowered their expression level. CONCLUSION: SLP could inhibit the function of cellular auto-secreting growth factor, it is one of the possible pharmacologic mechanism in intervening atherosclerosis.

Animals↗

PubMed2000

[Cytokine-induced release of plasminogen activator inhibitor-1 by human pleural mesothelial cells].

OBJECTIVE: To investigate the effects of inflammatory cytokines on the production of plasminogen activator inhibitor-1 (PAI-1) by human pleural mesothelial cells (HPMC). METHODS: Six primary cultures of HPMC isolated from patients with exudative pleural effusion were incubated in DMEM/F12 medium to examine the effect of interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNFalpha) or transforming growth factor-beta1 (TGF-beta1) on the fibrinolytic properties of HPMC in vitro. The purity of the cell population was assessed by morphologic, ultrastructural and immunohistochemical characteristics. PAI-1 activity in the conditioned media of third passage HPMC was detected using chromogenic substrate method. RESULTS: As compared with the controls, PAI-1 activity in the conditioned media of HPMC increased significantly by stimulation with IL-1beta, TNFalpha or TGF-beta1 for 24 hours at the level of 0.20 microg/L (IL-1beta: q = 3.38, P < 0.05; TNFalpha: q = 4.41, P < 0.05; TGF-beta1: q = 22.03, P < 0.01), 2.00 microg/L (IL-1beta: q = 12.28, P < 0.01; TNFalpha: q = 16.60, P < 0.01; TGF-beta1: q = 19.23, P < 0.01) and 20.00 microg/L(IL-1beta: q = 24.30, P < 0.01; TNFalpha: q = 25.00, P < 0.01; TGF-beta1: q = 49.30, P < 0.01). Furthermore, HPMC responses to TGF-beta1 were significantly greater than those to IL-1beta or TNFalpha. CONCLUSION: These results suggest that inflammatory cytokines might mediate the release of PAI-1 by HPMC in vivo, affect the deposition of fibrin within the pleural cavity and favor fibrogenesis.

Adult↗

PubMed2000

[Effects of all-trans retinoic acid and arsenic trioxide on tissue factor expression of acute promyelocytic leukemia cells].

OBJECTIVE: To investigate the effects of all-trans retinoic acid (ATRA) and arsenic trioxide (As(2)O(3)) on both tissue factor (TF) expression and procoagulant activity (PCA) of acute promyelocytic leukemia (APL) cells in vivo and in vitro. METHODS: The PCA of APL blasts freshly isolated from the APL patients treated with ATRA or As(2)O(3) was detected using a one-stage clotting assay; the TF antigen was detected by ELISA and TF mRNA by RT-PCR. The maturation sensitivity (NB4) or resistant subclones (NB4-R1) of the promyelocytic NB4 cell line as well as U937 cells transfected with pMSCV-PML-RARa treated with or without ATRA or As(2)O(3) were also examined. RESULTS: Both ATRA and As(2)O(3) time-dependently down-regulated the TF antigen, its mRNA transcription and membrane PCA of APL cells in vivo and in vitro. The TF antigen level in PML-RARa(+) U937 cells was significantly higher than that in U937 cells transfected with retrovirus vector (890 pg/8 x 10(5) +/- 80 pg/8 x 10(5) cell and 728 pg/8 x 10(5) +/- 86 pg/8 x 10(5) cell, respectively). Both ATRA and As(2)O(3) down-regulated the TF antigen of the U937 cells transfected with or without PML-RARa. CONCLUSION: Tissue factor expression and PCA of APL cells can be down-regulated by ATRA and As(2)O(3). By down-regulating the TF expression, As(2)O(3) might also be used to improve the DIC-related hemorrhage of APL. It is also suggested that elevated TF antigen in the PML-RARa(+) U937 cells may be related with the fusion protein PML-RARa, while the down-regulation effect of ATRA and As(2)O(3) on the TF expression of U937 cells might not be involved in the fusion protein.

Adolescent↗

PubMed2000

[Genome-wide loss of heterozygosity analyses in primary hepatocellular carcinoma].

OBJECTIVE: To investigate genome-wide loss of heterozygosity (LOH) and its clinical significance in primary hepatocellular carcinoma (HCC) in southern China. METHODS: LOH on 22 autosomes was investigated with 382 sets of microsatellite markers in 65 cases of HCC. RESULTS: The average rate of informative loci was 68.1%. More than 30% LOH was detected in loci on 17p (54.1%), 4q (48.1%), 16q (43.8%), 1q (38.3%), 8p (37.2%), 13q (33.7%), and 3p (30.8%). The frequency of LOH on D4S2964 (4q13-21) in HBsAg-positive cases was significantly higher than that in HBsAg-negative cases (P < 0.05). Cases with LOH on loci both D3S3681 (3p14-21) and D17S938 (17p13) had significantly higher rates of postoporative recurrence than those without LOH on these two loci (91% and 83% vs 52% and 65%, respectively). The 3-year survival rate was significantly lower in cases with LOH than in those without LOH on D17S938 (P < 0.05). CONCLUSIONS: LOH status in HCC patients in southern China is similar to that reported in other countries and areas. However, we first identified the high frequency of LOH on chromosome 3p in HCC. Furthermore, the infection of hepatitis B virus (HBV) may be correlated with the loss of some tumor suppressor genes on D4S2964 (4q12-13), and some tumor suppressor genes may reside on loci D3S3681 (3p12) and D17S938 (17p13), relating with tumor recurrence and prognosis.

Adolescent↗

PubMed2000

[Effects of mifepristone on estrogen and progestin receptors in human uterine leiomyoma].

OBJECTIVES: To study the effects of mifepristone on estrogen receptors (ER) and progestin receptors (PR) in human uterine leiomyoma and myometrium. METHODS: 20 patients with uterine leiomyoma who had surgical indication received 25 mg of mifepristone daily for 90 days beginning on the first day of menstrual cycle. Ultrasound examination, serum hormonal parameters, liver and renal function, electrolyte, complete blood count were monitored prior to and at the end of treatment. Hysterectomy or myomectomy was performed just when the treatment finished. Leiomyomata and myometrial tissue were obtained for immunohistochemical ER and PR analyses using monoclonal antibody. Control group included 20 patients who had matched age, weight, size and position of leiomyoma, and operated in the follicular phase of the cycle. RESULTS: After 90 days of mifepristone treatment, the leiomyoma volume decreased by (37.3 +/- 19.0)% and the uterine volume decreased (27.4 +/- 21.9)%. Hormonal parameters were within the levels of follicular phase. ER and PR positive rate in leiomyoma but not in myometrium of study group were significantly less than those of control group (P < 0.001). The positive rate of ER and PR of control group and PR of study group in leiomyoma were significantly higher than those in myometrial tissue of both groups (P < 0.05). ER of study group in leiomyoma was similar to myometrial tissue (P > 0.05). CONCLUSIONS: Mifepristone is a safe and effective drug for treating uterine leiomyoma. It can significantly decrease ER and PR in leiomyoma but not in myometrial tissue.

Adult↗

PubMed2000

[Synergistic efficacy of adenovirus-mediated bcl-Xs gene therapy and cisplatin in ovarian cancer cell].

OBJECTIVE: To observe the presence of synergistic efficacy between adenovirus-mediated bcl-Xs (Adv-bcl-Xs) gene therapy and cisplatin (CDDP) in ovarian cancer cell. METHODS: NuTu-19 cells were infected by different titers of Adv-bcl-Xs and treated with CDDP in the meantime. Percentage of cell proliferation was measured by methyl thiazolyl tetrazolium and cell cycles were measured by flow cytometry 3 days later. Graphical representations of the statistical analyses for their interaction in tumor cells. RESULTS: The statistical results and Graphical representations of the statistical modeling showed that the synergistic antiproliferative activity was present (P < 0.01). CONCLUSION: There was synergistic efficacy between Adv-bcl-Xs gene and CDDP for the inhibition of ovarian cancer cell.

Adenoviruses, Human↗

PubMed2000

[The inhibitory effect of bcl-2 antisense oligodeoxynucleotide/RNA on the growth of cervical carcinoma in vitro].

OBJECTIVE: To study the therapeutic effect of bcl-2 antisense oligodeoxynucleotide (ODN)/RNA human cervical carcinoma in vitro. METHODS: To transfect bcl-2 antisense ODN/RNA into Hela cells with antisense technology and observe the growth and apoptotic modulation of Hela cells. RESULTS: The expression of bcl-2 protein and mRNA was higher in Hela cells; the bcl-2 specific antisense ODN significantly decreased bcl-2 protein expression and inhibit the growth of Hela cells. The strongest inhibitory effect was at 24 hours after transfection, the optimal concentration of antisense ODN was 10 micromol/L. The results indicated that the inhibitory effect of bcl-2 antisense ODN on cell growth and survival rate is dose dependent; the recombinant retroviral vector pDOR-AB can transfer antisense bcl-2 gene into the genome of Hela cells, bcl-2 protein and mRNA expressions were significantly decreased after transfected, it demonstrated bcl-2 antisense RNA can significantly inhibit the growth of Hela cells and induce their apoptosis. CONCLUSION: The results demonstrate the feasibility of bcl-2 gene as a target for antisense gene therapy of human cervical carcinoma and provide the theoretical foundation and experimental evidence for further study in vivo.

Apoptosis↗

PubMed2000

[Investigation of prognostic factor and treatment mode for undifferentiated cervical carcinoma].

OBJECTIVE: To analyse the prognostic factor and investigate the treatment mode for undifferentiated cervical carcinoma. METHODS: The recurrent rate, the metastatic rate and the survival rate were analysed retrospectively for 146 patients with stage I-II cervical carcinoma of poor differentiation treated with radical operation, operation/chemotherapy, operation/radiotherapy, operation/chemotherapy/radiotherapy from Jan. 1990 to Oct. 1998. RESULTS: The recurrent rate of patients treated with radical operation/chemotherapy (18.18%) or radical operation/radiotherapy (24.32%) was lower than that of patients only treated with radical operation (36.36%) or operation/chemotherapy/radiotherapy (42.11%) for the cases of stage II or deep muscle invasion (P < 0.05). The recurrent rate of patients treated with radical operation/radiotherapy (22.22%) was lower than that of patients only treated with radical operation (2/2) for the cases with local lymphaden positive (P < 0.05). The investigation also showed that the distant metastatic rate of patients treated with radical operation/chemotherapy was 0.00%, which was lower than that of patients treated with radical operation 5.56% (P < 0.05). The 3-year survival rate was 100.00% and 88.53% respectively for the cases only treated with radical operation/chemotherapy or operation/radiotherapy; and it was lower for the cases treated with radical operation 76.74% (P < 0.05). CONCLUSIONS: The prognosis of undifferentiated cervical carcinoma is related to the lymph node metastasis, the International Federation of Gynecology and Obstetrics stage and the treatment methods. The local recurrent rate and distant metastasis might be reduced by 2 courses of chemotherapy or radiotherapy post-operatively. The recurrent rate could not be reduced effectively by the combination therapy of operation/chemotherapy/radiotherapy.

Adult↗

PubMed2000

[Total meso-rectal excision in low anterior resection with double stapling technique].

OBJECTIVE: To elucidate the value of total meso-rectal excision (TME) in low anterior resection with double stapling technique. METHODS: During January 1993 to October 1998, 306 cases of rectal lesions were treated by total meso-rectal excision in low anterior resection (LAR) with double stapling technique. Among the patients with rectal cancer, 235 (78.86%) were treated by low anterior resection and 97 (41.28%) by ultra-low anterior resection. RESULTS: No operative death was noted, and anastomotic leakage occurred in 9 (2.94%) patients. Ureter injury occurred in 2 (0.65%) patients. 32 (10.46%) patients suffered from anastomotic stenosis, 31 mm diameter of stapler for 27 (12.68%) patients and 33 mm diameter of stapler for 5 patients (5.38%). Local recurrence occurred in 20 (6.71%) patients: Dukes'B 4 (2.33%) patients, Dukes'C 9 (12.5%) patients, and Dukes'D 7 (53.85%) patients. CONCLUSIONS: Total meso-rectal excision can effectively reduce the local recurrence rate after LAR with double stapling technique. Since the recurrence is closely related to the stage of the disease, early detection, early diagnosis and early treatment are extremely important.

Adult↗

PubMed2000

[Early soft tissue coverage in treatment of severe open tibial fractures].

OBJECTIVE: To study the role of early soft tissue coverage in the treatment of severe open tibial fractures. METHODS: 76 open tibial fractures of type III b were divided into early group (0 - 7 days), subacute group (8 - 30 days), and late group(> 30 days) according to the coverage time of soft tissue. Complications such as infection and nonunion were compared. RESULTS: The infection and nonunion rates of early group were lower than those of the subacute and late groups. The average time to union of the early group was less than that of the subacute and late groups. CONCLUSIONS: Early soft tissue coverage can reduce the complications and the time to union of severe open tibial fractures. The time for "early" coverage should be limited in 1 week. The opportunity of nosocomial infection will increase after 1 week.

Adolescent↗

PubMed2000

[Primary non-specific ureteritis].

OBJECTIVE: To better understand primary non-specific ureteritis. METHODS: The etiological, clinical, and pathological manifestations, diagnosis, and treatment of 3 cases of primary non-specific ureteritis were discussed. RESULTS: Preoperative diagnosis failed. Uretero-ureterostomy was performed in 2 cases, and ureteroneocystostomy in one. The patients were free from hydronephrosis and ureteral dilatation. CONCLUSIONS: Diagnosis depends on pathological manifestations, differentiation from secondary non-specific ureteritis, ureteral tuberculosis, negative X-ray of ureteral stone and ureteral carcinoma. Surgical intervention is effective with good prognosis.

Adult↗

PubMed2000

[A study on the expression of p16 protein and bcl-2 protein in cutaneous eyelid tumors].

OBJECTIVE: To investigate the relationship between p16 (tumor suppressor) and bcl-2 (apoptosis inhibitor) gene expression and the incidence and development of eyelid malignant tumors. METHODS: Streptavidin-biotin-peroxidase complex immunohistochemical method was used to study the expression of p16 gene and bcl-2 gene in 96 cases with eyelid malignant tumors. RESULTS: In the 96 cases, including 40 cases of basal cell carcinoma (BCC), 33 squamous and 23 sebaceous carcinomas, their p16 protein positive (nuclear staining) rates were 70.0%, 54.6% and 56.5% respectively. The p16 positive rate was negatively correlated to the degree of tumor histological differentiation, and the rate difference between the high differentiated carcinoma and the low differentiated one was significant (P < 0.05). bcl-2 protein positive expression was detected in the cytoplasm. All of the 40 BCCs were bcl-2 positive and nearly all the tumor cells showed positive cytoplasmic expression, while in the 33 specimens of squamous cell carcinoma, only did one show positive focal reaction and the staining in other 32 cases was relatively faint. None of the 23 sebaceous carcinoma expressed bcl-2. CONCLUSIONS: The expression of p16 protein is related to the occurrence and degree of differentiation of eyelid malignant tumors. The over-expression of bcl-2 protein suggests that suppression of apoptosis might play a role in the tumorigenesis of BCC.

Adult↗

PubMed2000

[An epidemiological study on acute diarrhea during a filed exercise in PLA unit in an area in southern China].

OBJECTIVE: To explore the epidemiological characteristics and risk factors of acute diarrheal disease during a filed exercise. METHODS: Epidemiological study of a certain artillery acute diarrheal disease during a filed exercise and multiple linear stepwise regression analysis, multiple stepwise discriminate analysis were used. RESULTS: Result showed that the incidence rate of training troops was significantly higher than that of the local troops at the corresponding period (7.32% vs 0.98% P<0.05). The incidence rate among officers was significantly lower than that of the soldiers (0.99% vs 8.20% P<0.05). The incidence rate was significantly higher at the beginning of assemble for training but smooth and steady afterwards with several outbreaks. There was highly significant difference in the incidence rate of 39 companies. Regression and discrimination analysis suggested that the incidence rate was correlated with the density of flies and average boiled water volume provided everyday. The correct classifying rate of the discrimination was 91.9% in total. CONCLUSION: These results provided a basis for prevention of acute diarrheal disease during filed exercise of military action.

Acute Disease↗

PubMed2000

[Gena types of Shigella enterotoxins of S. flexneri 2a].

OBJECTIVE: To identify homogenous clones of S. flexneri 2a, using gene distribution polymorphism of Shigella enterotoxin 1 (set 1) and Shigella enterotoxin 2 (set 2) in a Shigellosis outbreak caused by S. flexneri 2a. METHODS: In addition to field epidemiological investigation, 43 strains of S. flexneri 2a were determined by polymerase chain reaction (PCR). RESULTS: The 43 strains (1 from food, 1 from a carrier, 41 from patients) were divided into 3 clones (set1 +/set2 + for 39 strains, set1 -/set2 + for 1, set1 +/set2 - for 3 strains). CONCLUSION: This outbreak was caused by S. flexneri 2a. The route of transmission was contaminated-food borne. Some sporadic cases were noticed during the outbreak. The method used in this study was satisfactory to the identification of S. flexneri 2a.

China↗

PubMed2000

[Study on the genetic difference of SEO type Hantaviruses].

OBJECTIVE: To understand the genetic type of Hantaviruses and the difference between them caused by rodents in Beijing and to furhter explore the source of the infectious factors. METHODS: Hantavirus RNA, isolated from lungs of rodents captured in Beijing and positive with Hantavirus antigens with frozen sectioning and Immunofluorescent assay, were reverse-transcribed and amplified with PCR with Hantavirus-specific primers. RESULTS: Five of the PCR amplifications were discovered and sequenced with 300 bp sequence data of M segments (from 2003 - 2302nt according cDNA of seoul 8039 strain). Nucleotide sequence homology showed that they were sequences of SEO-type Hantavirus. Compared with SEO type Hantavirus, the nucleotide sequence homology of these samples was more than 94% while the homology of amonia acid sequence was more than 98%. When compared with HNT type Hantavirus, the homology of nucleotide sequence became less than 72% with the homology of amonia acid sequence less than 81%. Similar to other Hantavirus of SEO type, their nucleotide sequences and deduced amino acid sequences were highly preserved. Phylogenetic tree analysis showed that the five viruses could be divided into at least 4 branches. CONCLUSION: It was quite likely that there were at least two sub-type SEO viruses with 4 branches that were circulating in Beijing.

DNA, Viral↗