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Biomedical subjects

S Wen

Publications and source records attributed to S Wen.

At least 55 records · Page 3Linked to original sources
PubMed1997

Epstein-Barr virus (EBV) infection in salivary gland tumors: lytic EBV infection in nonmalignant epithelial cells surrounded by EBV-positive T-lymphoma cells.

To elucidate the association of Epstein-Barr virus (EBV) and salivary gland tumors, 114 cases of tumors of major salivary glands were investigated. EBV DNA was detected in all 6 cases of undifferentiated carcinoma and all 3 cases of T-cell lymphoma, but not in other tumor tissues. In situ hybridization studies for EBV DNA and EBV-encoded small RNA 1 (EBER1) showed specific localization of the EBV sequences to the undifferentiated carcinoma cells and T-lymphoma cells. Moreover, intense DNA signals were detected on nonneoplastic epithelial cells of T-lymphoma tissues. These epithelial cells were negative for EBER1 and expressed BZLF1, BALF2, and gp350/220 proteins associated with virus production. In contrast, nonmalignant epithelial cells surrounded by undifferentiated carcinoma cells showed no evidence of EBV infection or virus replication. These results indicate that there is an unusual association of salivary gland T-cell lymphomas with lytic EBV replication of nonmalignant epithelial cells.

Carcinoma↗
PubMed1997

[Experimental and clinical studies on sternocleidomastoid myoperiosteal flap for laryngotracheal reconstruction].

In order to explore the value of sternocleidomastoid myoperiosteal flap for laryngotracheal reconstruction, eight dogs were included in the experimental study. After resecting the anterior body of the cricoid cartilage and tracheal tissue, the sternocleidomastoid myoperiosteal flap was used to close the defect immediately. All dogs were killed at two, four, six and eight months after operation. It was found that the sternocleidomastoid myoperiosteal flap had incorporated completely into the defect. Histologic studies by light and scanning electron microscopies showed complete epithelialization with no granuloma formation on surface of the flap and apparent metaplastic new bone formed in the periosteum which was crucial to the stability of the air way and long-term success of the procedure. Five patients who underwent subglottic and tracheal reconstruction with sternocleidomastoid myoperiosteal flap were successfully decannuated and had normal exercise tolerance. The results indicate that the sternocleidomastoid myoperiosteal flap is an ideal transplant for laryngotracheal reconstruction.

Adolescent↗
PubMed1997

Sputum microscopy results at two and three months predict outcome of tuberculosis treatment.

OBJECTIVE: To assess the importance of monitoring sputum conversion as an early treatment indicator of treatment success. METHODS: Retrospective analysis of sputum conversion in a cohort of 'cured' tuberculosis patients. RESULTS: Of 65 (95%) patients whose sputum converted in the third month of treatment, 62 were cured; only 21 of 35 (60%) patients whose sputum was still positive at the end of three months of treatment were ultimately cured. CONCLUSION: Sputum conversion during the third month of treatment is an important predictor of treatment success; failure to convert predicts treatment failure.

Antitubercular Agents↗
PubMed1997

[Human parvovirus B19 infection in perinatal transmission and abnormal fetuses].

OBJECTIVE: To investigate the perinatal infection of human parvovirus B19 in pregnant women and their fetuses. METHODS: 350 sera of normal pregnant women and 9 sera of abnormal fetuses were investigated by polymerase chain reaction (PCR) to check the parvovirus B19 DNA. RESULTS: The prevalence of parvovirus B19 DNA was 1.14% and 0.28% in the sera of normal pregnant women and umbilical cords, respectively. Parvovirus B19 DNA was detected in 6 sera of pregnant women and umbilical cords from 9 abnormal fetuses parvovirus DNA could be detected by in situ hybridization in the nuclei of immature hematopoetic cells within fetal brain or spleen whose PCR tests were positive. CONCLUSION: The results suggest that parvovirus B19 infection do exist in pregnant women and their neonates as well as fetuses in our country. PCR and in situ hybridization could provide more sensitive, more accurate and specific methods for clinical pathologic diagnosis and epidemic investigation.

Adult↗
PubMed1996

Flow velocity of single lymphatic capillaries in human skin.

The purpose of this study was to investigate the previously unknown flow velocity in single lymphatic capillaries of humans in the supine position. Fifteen healthy subjects (10 women and 5 men; mean age 35.8 +/- 13.1 yr) were studied. Ten microliters of fluorescein isothiocyanate-dextran (150,000 mol wt) were injected into the subepidermal layer of the foot dorsum. The filling of the microlymphatics from the resulting depot was visualized by fluorescence video microscopy and stored on videotape. Flow velocity in the microlymphatics was determined on the video screen by direct measurement of the advancement of dyed lymph during a given time. The following median velocities were obtained: 0.51 mm/s (0.27 and 0.61 mm/s for lower and upper quartiles, respectively) for velocity during initial network filling and 9.7 microns/s (6.9 and 14.2 microns/s for lower and upper quartiles, respectively) for resting velocity at the end of the filling period. Mean lymphatic capillary diameter was 54.8 +/- 8.2 microns, and mean network extension was 8.3 +/- 3.2 mm. The high filling velocities are probably due to increased interstitial pressure and volume caused by dye microinjection, whereas the values measured during the end of network filling seem to approach resting flow velocities.

Adult↗
PubMed1996

Association of Epstein-Barr virus (EBV) with Sjögren's syndrome: differential EBV expression between epithelial cells and lymphocytes in salivary glands.

The association of Epstein Barr virus (EBV) with Sjögren's syndrome (SS) is still in dispute. This study is aimed to investigate the existence of EBV genomes and their products in salivary glands of SS. Salivary gland samples were surgically obtained from Chinese patients. EBV DNA was detected in three of seven cases by dot blot hybridization and in four of seven cases by in situ hybridization. The EBV-encoded small RNA-1 (EBER1) was detected in two of seven cases by in situ hybridization. The immunohistochemical staining of EBV proteins showed that the EBV latent membrane protein-1 was detected in four of seven cases and that BZLF1, BALF2, and gp350/220 proteins associating with virus production were not expressed. In eight controls, no positive signal was observed by these methods. DNA in situ hybridization identified ERV on both epithelial cells and lymphocytes. On the other hand, EBER1-positive signals were exclusively localized on lymphocytes. These results indicate that two forms of EBV infection may exist in salivary glands of SS. One is EBER1-positive latency in lymphocytes, the other is EBER1-negative latency in epithelial cells. Frequent EBV detection in salivary glands of SS suggests that EBV plays a role in the genesis of SS.

Adult↗
PubMed1996

[Analysis of short-term effects of short-course intermittent chemotherapies of the World Bank Loaned Project].

OBJECTIVE: To explore the characteristic features of sputum conversion during short-course intermittent chemotherapies and the measures of keeping high cure rates. METHODS: 1,350 smear positive pulmonary tuberculosis cases in the ten research pilot counties of Liaoning province from 1992 to 1993 were selected to receive short-course intermittent chemotherapies under full-course supervision. The project was supported by the World Bank. The sputum specimens of the cases were regularly examined. The effects of the chemotherapies and the measures of keeping high cure rate were evaluated according to the situation of sputum conversion. RESULTS: The cure rates of initial and relapse smear positive cases were 92.5% and 74.6% respectively. It is also found that the therapeutic effects were affected by the situation of sputum conversion at the end of intensive phase. The cure rate of the cases who failed in initial treatment and continued retreatment was only 54%, which was obviously lower than that of the other retreatment cases. CONCLUSION: Strengthening the treatment and management at the intensive phase can increase the cure rate. It is recommended that more rational regimens should be studied and provided to those who fail in initial treatment to improve the therapeutic effects.

Antibiotics, Antitubercular↗
PubMed1995

Microcapsules through polymer complexation. Part 3: Encapsulation and culture of human Burkitt lymphoma cells in vitro.

Methacrylic acid (MAA) based polyelectrolytes were complexed with protonated or quaternized dimethylaminoethyl methacrylate (DMAEMA) containing polyelectrolytes to form microcapsules in vitro. Anchorage independent human Burkitt lymphoma (Raji) cells were successfully cultured in the presence of dissolved MAA containing polymer. Capsule morphology was investigated by light microscopy and by scanning electron microscopy (SEM). Capsules based on quaternized DMAEMA containing polymer were found to be more stable than capsules containing protonated DMAEMA functionality. Raji cells were successfully encapsulated in both systems and divided to confluence; thereafter sufficient pressure was exerted to burst open the capsules. Cells released from these capsules appeared to suffer no discernible trauma and were successfully isolated and subcultured to confluence.

Burkitt Lymphoma↗
PubMed1995

The significance of PCNA and p53 protein in some oral tumors.

The expression of PCNA and p53 protein was evaluated in a total of 75 cases of benign and malignant lesions of the oral cavity, comprising 50 squamous cell carcinomas (SCCs), 14 leukoplakias, and 11 pleomorphic adenomas. The DNA histogram of 20 SCCs was measured by flow cytometry. p53-positive cells were frequently seen in SCCs, but were rare in leukoplakias and pleomorphic adenomas. The PCNA labeling index (LI) was higher in SCCs than in other benign lesions. The expression rate of p53 protein was markedly elevated in SCCs obtained from smoking patients, when compared to nonsmoking patients. DNA ploidy did not show a close relationship with PCNA and p53 expression. The mean value of PCNA LI for 22 cases carrying positive p53 protein was 52.3%, which was higher than that of p53 protein negative cases (35.7%). The Kaplan-Meier survival curve of the patients who were negative for p53 was significantly more favorable than for patients who were positive for p53 (P < 0.01, Cox-Mantel test). These results suggest that PCNA and p53 LI are markers for the malignant potential of the oral mucosa, and are a useful indicator suggesting a poor prognosis.

Actuarial Analysis↗
PubMed1995

Cytoplasmic expression of p53 protein and its morphological features in salivary gland lesions.

An immunohistochemical study of p53 protein was carried out on 45 salivary gland lesions using a monoclonal antibody, Bp53-12, raised to the intracellular domain of the p53 protein. p53 protein expression was found in 34.4% of 32 salivary gland carcinomas. Nuclear p53 expression was detected in tumor cells but not in non-neoplastic cells, except in one salivary duct carcinoma. The perinuclear cytoplasm of luminal duct cells was specifically positive for the antibody used here. Cytoplasmic p53 expression was observed mostly in non-neoplastic cells. There was a tendency for the cytoplasmic staining of p53 protein to be observed in the normal cells adjacent to p53-positive carcinomas, but none of the normal cells were positive in the tissues surrounding p53-negative carcinomas. Cytoplasmic expression of p53 protein in salivary gland tissues seems to be correlated with tumorigenesis.

Animals↗
PubMed1995

A fluorescence in situ hybridization (FISH) analysis with centromere-specific DNA probes of chromosomes 3 and 17 in pleomorphic adenomas and adenoid cystic carcinomas.

Aberrations of chromosomes 3 and 17 were studied by FISH using centromere-specific DNA probes in 11 salivary adenoid cystic carcinomas (ACC) and 8 salivary pleomorphic adenomas (PA), with 3 lymph nodes as controls. Two hybridized signals were detected in 92.8 +/- 2.7% of controls, 73.2 +/- 7.0% of PA and 66.8 +/- 7.9% of ACC cells for chromosome 3, and in 90.4 +/- 2.3% of controls, 59.5 +/- 25.0% of PA and 44.8 +/- 20.2% of ACC for chromosome 17. More than 3 hybridized signals, which indicate polysomy, were observed in 3.1% of controls, 15.5% of PA and 22.9% of ACC cells for chromosome 3, and in 1.2% of controls, 10.3% of PA and 23.1% of ACC cells for chromosome 17. A single hybridized signal was much more frequent for chromosome 17 than for chromosome 3. These findings suggest that polysomy of both chromosomes occurs during the development of salivary gland tumors, and its frequency is increased in adenoid cystic carcinoma as compared to pleomorphic adenoma. In addition, monosomy of chromosome 17 could possibly be significant in salivary gland tumors.

Adenoma, Pleomorphic↗
PubMed1995

Reproductive isolation between Drosophila lini and its siblings.

Courtship behavior and reproductive isolation between nine strains of Drosophila lini and its siblings from Taiwan (TWN), Dinghushan (DHS) and Nankunshan (NKS) in China, and Pyinoolwin (MMY) and Yangon (RGN) in Myanmar were investigated. No premating and postmating isolation between the Taiwan and mainland China strains were found. Crosses between mainland China (DHS and NKS) or the TWN strain and the MMY or RGN strain produced fertile F1 hybrid females and sterile F1 hybrid males. Crosses between MMY strains and RGN strains which showed strong premating isolation produced either no F1 hybrids, or fertile F1 hybrid females and sterile males in some cases. These results suggest the existence of at least three genetically distinct sibling species of D. lini.

Animals↗
PubMed1995

[Inhibition of hepatitis B viral gene expression and replication in vitro by targeted antisense oligonucleotides].

We chose the 2.2. 15 cells as an in vitro cell culture assay system, and identified the surface antigen subtype of hepatitis B virus (HBV) DNA in the cells, by using the amplification of polymerase chain reaction and directed sequencing of amplified products. According to the result of the sequencing, a 16-mer phosphorothioate analogue of the antisense oligonucleotide (PS-ASON) directed against the HBV U5-unique region was synthesized and then linked with two liver-targeting ligands. The galactosylated human serum albumin coupled poly-L-lysine and the galactosylated poly-L-lysine. The effect of different modifications of ASONs on the expression of HBV gene was compared by using the 2.2. 15 cells. In the same experimental conditions, the inhibitary effects of surface antigen (HBsAg) and antigen (HBeAg) by PS-ASON were 70% and 58% respectively, and those of HBsAg and HBeAg by ligand-PS-ASONs were 90%-96% and 78%-82%. In the same time, the amount of HBV NDA in culture supernatant and cells was depressed significantly. Thus, the ligands targeted ASON to the hepatocytes were more effective inhibitors of HBV gene expression. ASONs were effective and specific inhibitors of HBV replication and expression, caused the dose-dependent inhibition of viral proteins and had no effect on cellular alpha-fetoprotein synthesis and no cytotoxicity.

Base Sequence↗
PubMed1995

[Retrograde insertion of a spherical headed silicon tube through nasolacrimal duct].

PURPOSE: Chronic dacryocystitis or obstruction of nasolacrimal duct is one of the common and refractory eye diseases. The present operations have large destruction to lacrimal passage and unsatisfactory effects. The purpose of this research is to explore a simple and easy surgical method that makes small injuries and good curative effects. METHODS: Prob a self-made lumbar puncture needle (No. 7) through the lacrimal drainage system, inject fluid and put a thread into the inferior meatus. Guided by the thread, a special robe is retrogradely pulled through the nasolacrimal duct to dilate the meatus to about 3 mm. Then a silicon tube with a spherical head was inserted in the same may. RESULTS: 37 cases with chronic dacryocystitis or obstruction of nasolacrimal duct were treated by the method and followed up from 6 to 17 months. The result showed that the naso meatus was unobstructed postoperatively. The curative rate was 83.7%, which is better than that of other surgical methods. CONCLUSION: This operation is simple and painless for patients; has good curative effects and no severe complications: seldomly injures the normal lacrimal drainage system; can be done repeatedly or replaced by dacryocystorhinostomy if the procedure fails and will become the primarily elected method th treat the patients with chronic dacryocystitis and obstruction of the nasolacrimal duct.

Adult↗