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Biomedical subjects

C S Wang

Publications and source records attributed to C S Wang.

At least 19 recordsLinked to original sources
PubMed2006

Interferon-based combination anti-viral therapy for hepatitis C virus after liver transplantation: a review and quantitative analysis.

Recurrence of hepatitis C virus (HCV) infection after liver transplantation (LT) is universal. However, the efficacy, tolerability and safety of combination interferon and ribavirin (IFN-RIB) or peginterferon and ribavirin (PEG-RIB) anti-viral therapies post-LT are uncertain. We performed a comprehensive search of major medical databases (1980-2005) and conference proceedings (1996-2005). The main outcome measure was sustained virological response (SVR, undetectable HCV RNA) at 6 months. Summary estimates were calculated using random-effects models. Twenty-seven IFN-RIB and 21 PEG-RIB studies were included. IFN-RIB was associated with a pooled SVR rate of 24% (95% CI, 20-27%), while PEG-RIB was associated with an SVR rate of 27% (23-31%). Pooled discontinuation rates were 24% (21-27%) with IFN-RIB and 26% (20-32%) with PEG-RIB. The pooled rate of acute graft rejection was 2% (1-3%) with IFN-RIB and 5% (3-7%) with PEG-RIB. IFN-RIB and PEG-RIB therapies in HCV infection post-LT were associated with similar but overall low SVR and were poorly tolerated. The rate of acute rejection was small. The therapeutic advantage of PEG-RIB therapy observed in non-transplant chronic HCV infection appears to be attenuated post-LT. Clinical trials are needed to evaluate reasons for this post-transplant therapeutic disadvantage and to find strategies to ameliorate them.

Antiviral Agents↗
PubMed2005

Quantum coherence in an optical modulator.

Semiconductor quantum well electroabsorption modulators are widely used to modulate near-infrared (NIR) radiation at frequencies below 0.1 terahertz (THz). Here, the NIR absorption of undoped quantum wells was modulated by strong electric fields with frequencies between 1.5 and 3.9 THz. The THz field coupled two excited states (excitons) of the quantum wells, as manifested by a new THz frequency- and power-dependent NIR absorption line. Nonperturbative theory and experiment indicate that the THz field generated a coherent quantum superposition of an absorbing and a nonabsorbing exciton. This quantum coherence may yield new applications for quantum well modulators in optical communications.

Journal Article↗
PubMed2003

Studies on epizootic iridovirus infection among red sea bream, Pagrus major (Temminck & Schlegel), cultured in Taiwan.

Since 1993, an epizootic viral disease has occurred in net-cage cultured red sea bream, Pagrus major (Temminck & Schlegel), in Peng-hu Island located on the south-western coast of Taiwan. The diseased fish exhibited abnormal swimming and were lethargic, but few visible external signs were observed. The cumulative mortality because of the disease sometimes reached 50-90% over 2 months. Histopathogical studies of the affected fish showed enlarged basophilic cells in the gill, kidney, heart, liver and spleen. These necrotic cells were Feulgen-positive and stained blue using Giemsa. Transmission electron microscopy revealed icosahedral virions in the cytoplasm of the necrotic cells. The viral particles consisted of a central nucleocapsid (75-80 nm) and envelope, and were 120-150 nm in diameter. These results suggest that the virus belongs to the Iridoviridae. Using polymerase chain reaction (PCR), approximately 570 bp fragments were produced from the viral DNA using as a template 1-F and 1-R primers derived from red seabream iridovirus (RSIV) from red sea bream in Japan. Similar results were also obtained using nested-PCR with different primer sets (1-F, 2-R and 2-F, 1-R). Although the size and some features of epizootics of this virus differed from RSIV in Japan, it shows close genetic affinities with the latter and it is suggested that RSIV has been introduced to Taiwan.

Animals↗
PubMed2002

Removal of dissolved natural organic matter from source water with alum coagulation.

In this study, the effectiveness of enhanced alum coagulation for removal of natural organic matter (NOM) at various alum dosages and pH conditions was assessed for three source waters. Results from the laboratory jar tests at various conditions were compared. Tested pH ranged from 5.0 to 8.0, with alum dosages ranging from 60-120 mg l(-1) for removal of dissolved NOM with various concentration of dissolved organic carbon (DOC) and alkalinity. Alum coagulation profiles of the three source waters were also compared. For Cheng-Kung Water Treatment Plant (high DOC, high alkalinity), laboratory tests showed 50% DOC removal with alum dosage of 70-110 mg (-1). after acidifying the raw water to pH = 6. For Tai Lake Water Treatment Plant (high DOC, low alkalinity), laboratory tests showed that the highest DOC removal (approximately 50%) was achieved at an alum dosage of 80 mg l(-1) at pH = 8 (natural condition). However, alum coagulation showed little DOC removal for source water from Kee-Lung River (low DOC, low alkalinity). Higher alkalinity in Cheng-Kung Reservoir accounts for the necessity to acidify the raw water before enhanced coagulation for optimum DOC removal.

Alum Compounds↗
PubMed2001

Expression of cathepsin D, stromelysin-3, and urokinase by reactive stromal cells on breast carcinoma prognosis.

BACKGROUND: Current literature suggests that several proteases act in a cascade to mediate remodeling of the extracellular matrix and favor cancer progression. Others and the authors of this study recently identified cathepsin D, stromelysin-3, and urokinase plasminogen activator (uPA) expression by reactive stromal cells as significant factors of poor prognosis in breast carcinoma. The authors evaluated the joint effect of protease expression on cancer aggressiveness. METHODS: Protease expression was analyzed by immunohistochemistry (cathepsin D) and in situ hybridization (stromelysin-3 and uPA) on formalin fixed paraffin embedded specimens from 557 breast carcinomas without distant metastasis at diagnosis and with an average of 10 years of follow-up. RESULTS: Of the 557 breast carcinomas, 80 (14.3%) expressed all 3 proteases, and 134 (24%) expressed none of them. An adjusted Cox model revealed significantly worse distant metastasis free survival (DMFS) with expression of all three proteases (P < 0.0001). The DMFS of patients whose tumor lacked at least one of the three proteases was similar to that of patients without any protease expression, irrespective of the type or number of proteases missing. CONCLUSIONS: This study suggests that proteases expressed by reactive stromal cells are interdependent and that a breach in the protease pathway may impair breast carcinoma progression.

Breast Neoplasms↗
PubMed2001

Using the prevalence of an elevated serum alanine aminotransferase level for identifying communities with a high prevalence of hepatitis C virus infection.

BACKGROUND: Antibody to hepatitis C virus (anti-HCV) is a widely accepted method for the diagnosis of HCV infection. However, it is too expensive to use in large-scale health surveys. OBJECTIVE: To investigate the use of the serum alanine aminotransferase (ALT) level to predict the prevalence of HCV infection. PATIENTS AND METHODS: A sample of 6095 residents aged 35 years old or older in a small township of southern Taiwan, Republic of China, were examined in a community health survey. These persons were walk-ins to the government-sponsored stations after an intensive health promotion for this survey. Blood samples were obtained and analyzed for serum ALT levels. The presence of hepatitis B surface antigen and anti-HCV were determined by enzyme immunoassay methods. RESULTS: The overall prevalences of hepatitis B surface antigens(+), anti-HCV(+), and elevated ALT levels were 11.8%, 15.0%, and 7.5%, respectively. Among the 13 villages in this community, the prevalence of hepatitis B surface antigen(+) ranged from 6.8% to 17.3%, anti-HCV(+) ranged from 7.2% to 37.6%, and an elevated ALT level ranged from 5.8% to 16.5%. A strong positive correlation was found between the prevalence of an elevated ALT level and anti-HCV(+) (r= 0.91, Spearman rank correlation; P<.001). However, nearly 0 correlation (r= -0.05, P=.87) was obtained between the prevalence of an elevated serum ALT level and hepatitis B surface antigen(+). CONCLUSION: The prevalence of an elevated serum ALT level in a community is a strong indicator of its prevalence of anti-HCV(+), even in areas where there is a similar prevalence of hepatitis B virus infection. This result is useful for economically identifying hyperendemic communities with HCV infection.

Alanine Transaminase↗
PubMed2001

Ultrasound-guided core needle biopsy as an initial diagnostic test for palpable breast masses.

PURPOSE: To determine the role of ultrasound (US)-guided core needle biopsy as an initial diagnostic test for palpable breast masses. MATERIALS AND METHODS: Ninety-eight consecutive patients, each with a palpable breast mass, were referred for US-guided core biopsy by a multidisciplinary team of physicians who specialize in the care of breast diseases. All palpable breast masses were clearly visible on high-resolution US. Ninety-nine core needle biopsies were performed under local anesthesia with use of freehand technique, mostly in an outpatient setting. Core needle path through each mass was documented in two orthogonal sections. A mean of 3.4 tissue core samples (range, 1-7) were obtained in each patient. RESULTS: Core needle biopsy resulted in the diagnosis of 66 malignancies, two cases of atypical ductal hyperplasia (ADH), and 30 benign diseases of the breast. Surgery with curative intent was performed in 63 breast malignancies and excisional biopsies were performed for 10 benign diseases (two cases of ADH and eight benign lesions). Twenty-five breast masses were managed nonoperatively: chemotherapy was performed in three locally advanced breast cancers and 3-year follow-up was conducted for 22 benign lesions. Malignancies were correctly diagnosed in all cases. No malignancy was discovered at surgery or during clinical follow-up of ADH and no benign breast lesions were diagnosed by core needle biopsy. US-guided core needle biopsy is 100% sensitive and specific for palpable breast malignancies, with no false-positive results. A puncture site ecchymosis was the only morbidity or complication noted. CONCLUSION: US-guided core needle biopsy is a safe and accurate first diagnostic test for palpable breast masses that require tissue proof.

Adult↗
PubMed2001

Characteristics of males who father babies born to adolescents versus older adult women in Taiwan.

PURPOSE: To identify characteristics of males who father babies born to adolescent mothers in southern Taiwan. METHODS: This was a population-based cross-sectional study of male partners of 1,145 primigravidas (555 adolescent primigravidas and 590 adults) in Kaohsiung County, Taiwan, which compared their reports of their male partners' characteristics. Data were collected by a questionnaire that included demographic characteristics, health behavior problems, and attitudes toward the pregnancy. RESULTS: In multiple logistic regression analyses, the males who father babies born to adolescent primigravidas achieved a lower level of education; a greater age discrepancy between themselves and the mothers; a greater unemployment rate; less financial independence; more smoking, drinking, and drug abuse; less supportive attitude toward pregnancy; poorer attendance at childbirth; less provision of postpartum care for mothers and infants; and greater domestic violence than adult primigravidas (p < .05). These negative findings persist even after stratification by age discrepancy. Male partners of the adolescent mothers with an age difference of 5 years or more were more likely to report drug abuse and domestic violence than those of adult primigravidas. CONCLUSIONS: Males who father babies born to adolescent primigravidas were found to have many negative characteristics that place their partners and offspring at risk. Questions asked of or about the father of the baby during prenatal visits may help identify pregnant adolescents who need support during pregnancy and after delivery.

Adolescent↗
PubMed2001

Selective culture of epithelial cells from primary breast carcinomas using irradiated 3T3 cells as feeder layer.

The main drawback of the selective culture of human mammary epithelial cells from primary breast cancer is the overgrowth of tumor-associated stromal fibroblasts. This drawback may be overcome by using, in primary culture, lethally irradiated 3T3 cells which act as a feeder layer to maintain tumor-derived epithelial cell proliferation. These 3T3 cells, exposed to 60 Gy at confluence, form a specific cellular substrate which constitutes an obstacle to fibroblast attachment. Enzyme-disaggregated breast cells from six primary breast carcinomas were cocultured over lethally irradiated but living 3T3 cells. The method led to the purification of tumor-derived epithelial cells from all six cancer samples, and long-term culture was obtained in one. The epithelial nature of these purified tumor-derived epithelial cells was demonstrated by their general morphology and by the expression of cytokeratins and Epithelial Membrane Antigen. These results confirm the stimulatory effect of a this stromal feeder layer on breast epithelial cell growth and show that this stromal feeder layer can also control the fibroblast overgrowth. Our results provide an alternative approach in the selective culture of epithelial cells from primary breast carcinoma.

3T3 Cells↗
PubMed2001

Risk factors for low birth weight among first-time mothers in southern Taiwan.

BACKGROUND AND PURPOSE: Low birth weight (LBW) greatly affects infant development, the family, and health care financial systems. Nonetheless, the risk factors for LBW in Taiwan have not been investigated. The purpose of this study was to determine the risk factors for LBW in Kaohsiung County. METHODS: In this cross-sectional study, we recruited 1,147 first-time mothers, including all adolescent mothers (< 20 years old) who gave birth during the period from June 1994 through May 1995 and all adult mothers (> or = 20 years old) who gave birth in January and February 1995. The subjects were interviewed during home visits or by telephone by public health nurses in each township. Logistic regression analysis was used to identify the risk factors for LBW in adolescent and adult mothers. RESULTS: The prevalence of LBW in the study population was 6.2%, ranging from 7.6% in adolescent mothers to 4.9% in adult mothers. Univariate analysis showed that mothers who had low pregravid weight (< 45 kg), infrequent prenatal visits (< 10), anemia, low gestational weight gain (< 10 kg), or habits of alcohol consumption or cigarette smoking were more likely to give birth to LBW infants. In logistic regression analysis, after controlling for covariates, the significant risk factors for LBW were low gestational weight gain (< 10 kg) and low pregravid weight (< 45 kg) for adolescent mothers. Infrequent prenatal visits (< 10) was the only significant risk factor for adult mothers. CONCLUSIONS: In this study, the risk factors for LBW among adolescent and adult mothers were different. This suggests that programs for prevention of LBW should be tailored according to maternal age, begin before conception, and continue with enhanced surveillance during prenatal visits.

Adolescent↗
PubMed2000

Establishment and characterization of a new cell line derived from a human primary breast carcinoma.

A new cell line, designated HDQ-P1, was successfully established from a primary ductal infiltrating mammary carcinoma by using a 3T3 feeder layer lethally irradiated to 60 Gy. The HDQ-P1 cells have been grown in culture for over 115 passages and have a doubling time of 60 hours. Characterization of the cell line was performed. This included morphology by light and transmission electron microscopy, karyotype, growth rate, telomerase expression, tumor antigen expression, xenograft implantation into nude mice, colony formation in soft agar, TP53 sequencing, and gene copy number of C-MYC, C-ERBB-2, and C-H-RAS oncogenes. The epithelial nature of this cell line was confirmed by ultrastructural analysis, expression of cytokeratins, and epithelial membrane antigen. The HDQ-P1 cells possess an extensively rearranged and polyploid karyotype, with an average of 20 recurrent marker chromosomes. Scatchard analysis demonstrated that both primary tumor and HDQ-P1 cells were estrogen- and progesterone-receptor negative. The HDQ-P1 cells had the same expression of human telomerase reverse transcriptase as other established breast cancer cell lines such as MDA-MB-231, SK-BR-3, and MCF-7. Direct DNA sequencing showed a point mutation which yielded to a stop codon at the amino acid 213 in exon 6 of the TP53 gene. A five-fold amplification of C-MYC was observed in HDQ-P1 cells. No amplification of C-ERBB-2 and C-H-RAS genes were observed. This cell line presents unique characteristics and may prove to be a good experimental model for investigating breast cancer biology.

Animals↗
PubMed2000

Choline plus cytidine stimulate phospholipid production, and the expression and secretion of amyloid precursor protein in rat PC12 cells.

The amyloid precursor protein (APP) is a transmembrane protein anchored in the membrane lipid bilayer. Choline and cytidine are major precursors of cell membranes, and are regulatory elements in membrane biosynthesis. We examined the levels of cellular APP holoprotein and secreted APPs when rat PC12 cells are stimulated to undergo increase in membrane phospholipids by choline+cytidine (2+2, 5+5, 10+10 or 50+50 microM) treatment. We now show that as phospholipids levels are increased by supplemental choline and cytidine treatment, the levels of cell-associated APP also rise stoichiometrically; these treatments also caused major (up to 6. 8-fold) increases in the amounts of secreted APP released into the cell medium, and also stimulated increased process formation. These results show that choline plus cytidine increase both phospholipid levels, and the expression and secretion in PC12 cells. It appears that agents that stimulate cellular membrane biosynthesis may be used to stimulate the secretion of neurotrophic APPs and neurite formation in neurodegenerative disorders such as Alzheimer's disease.

Alzheimer Disease↗
PubMed2000

Aspiration in chest compression alone without mechanical ventilation in the head down position in dogs.

BACKGROUND: Previous work by the authors has shown that chest compressions alone without mechanical ventilation during cardiopulmonary resuscitation in the natural supine position was associated with pulmonary aspiration in dogs. The purpose of this investigation was to test the hypothesis that a head down position may prevent aspiration during chest compressions alone and whether oxygenation can be improved by simply insufflation of oral oxygen 10 min after cardiac arrest. METHODS: Cardiac arrest was induced in ten mongrel dogs which were anesthetized and paralysed. Eight underwent chest compressions alone in different head down positions using an automatic compressor at 9 kg compression force and 3 cm compression depth. The study was composed of two parts. Part 1 evaluated the effect of insufflation of 10 l/min O2, into the mouth of the dogs, 10 min after initiation of resuscitation, using chest compressions alone. Part 2 was designed to test our hypothesis that the head down position may protect the lungs from aspiration during chest compression alone. The mouths of the dogs were filled with mixed barium and the dogs underwent serial episodes of chest compressions, for 10 min each, in the 20 degree head down, 10 degree head down and the natural supine positions. Chest X-rays with antero-posterior and lateral views were taken to evaluate pulmonary aspiration. Two additional dogs underwent direct chest compression alone in the natural supine position and the time of chest compression was shortened to 5 min. RESULTS: All dogs in the natural position showed evidence of pulmonary aspiration of barium, five or six of the dogs showed tracheal aspiration in the 10 degree head down position, while no any barium was visualized in the tracheo-broncheal trees of the dogs in the 20 degree head down position. Supplemental oxygen in the mouth improved the mean PaO2 from 67 +/- 26 to 160 +/- 97 mmHg during chest compressions alone. CONCLUSION: Chest compression alone without mechanical ventilation in the supine position caused pulmonary aspiration in the unprotected airway in dogs. This complication could be prevented by adopting a 20 degree head down position. The 10 degree head down position seemed to reduce the severity of the pulmonary aspiration, but not enough to eliminate the danger altogether. Supplemental oxygen in the mouth can improve oxygenation in chest compressions alone.

Administration, Oral↗
PubMed2000

Status and natural course of GB virus C/hepatitis G virus infection among high-risk groups and volunteer blood donors in Taiwan.

BACKGROUND: Hemophilia, thalassemia and uremia patients are at risk of parenterally transmitted infectious agents. The status and nature of the course of GB virus C/hepatitis G virus (GBV-C/HGV) infection among these groups and blood donors in Taiwan was investigated. METHODS: Serum GBV-C HGV-RNA and antibodies to GBV-C/HGV envelope-2-protein (anti-E2) were determined in 500 blood donors and in 44 hemophilia, 37 thalassemia and 85 uremia patients. Phylogenetic analysis was performed. RESULTS: The prevalence of GBV-C/HGV-RNA and anti-E2, respectively, was 38.6 and 27.3% in hemophilia patients, 27.0 and 27.3% in thalassemia patients, 14.1 and 10.6% in uremia patients and 3.4 and 7.2% in blood donors. The prevalence of GBV-C HGV exposure was 59.1 and 51.4% in hemophilia and thalassemia patients, respectively, which was significantly higher than that for uremia patients (22.4%; P < 0.01) and blood donors (10.2%; P < 0.001). The anti-E2 seroconversion rate was 66.7% in blood donors and 47.4, 36.8 and 34.6% in thalassemia, uremia (P < 0.05 compared with blood donors) and hemophilia (P < 0.01 compared with blood donors) patients, respectively. Discrepancies in the prevalence of GBV-C HGV and hepatitis C virus infection were found among the three risk groups. Phylogenetic analysis showed that 51 of 56 GBV-C HGV isolates clustered in group 3; the remaining five were of group 2a. Twelve of 39 viremic patients in the risk groups cleared the virus during the 4 year follow-up period; seven developed concomitant anti-E2 reactivity. CONCLUSIONS: GB virus C hepatitis G virus infection is epidemic among risk groups and GBV-C HGV group 3 is the major strain in Taiwan. In the risk groups, approximately 18% of infections resolve with concomitant anti-E2 seroconversion within 4 years.

5' Untranslated Regions↗
PubMed2000

Active ion secretion and permeability of rabbit maxillary sinus epithelium, impact of staphylococcal enterotoxin B.

The aim of this study was to investigate the impact of staphylococcal enterotoxin B (SEB), a model superantigen, on the physiologic functions of rabbit maxillary sinus epithelium. Rabbit sinus mucosae were separated under a surgical microscope and mounted in Ussing chambers to record short-circuit current, conductance, and permeability to horseradish peroxidase. The results showed that SEB evoked increases in sinus epithelial cell baseline short-circuit current, conductance, and permeability to horseradish peroxidase. When tumor necrosis factor-alpha (TNF-alpha) was added to the Ussing chambers, we got results similar to those obtained by SEB stimulation in vitro; the effects of SEB on sinus epithelial cells could be blocked by pretreatment with anti-TNF-alpha antibody. These results demonstrate that SEB is able to alter the function of sinus epithelial cells and to affect the capability of the epithelial defensive barrier, which may be mediated by TNF-alpha.

Animals↗
PubMed2000

A pollen-specific and desiccation-associated transcript in Lilium longiflorum during development and stress.

A cDNA clone encoding a desiccation-induced protein (LLA23) has been isolated from the mature pollen of a Lilium longiflorum cDNA library. Sequence analysis revealed significant similarity between the predicted LLA23 polypeptide, particularly at the C-terminal half of the sequence and a group of water-deficit/ripening-induced proteins. The expression of LLA23 gene is pollen-specific and the transcript accumulates only at the later stage of pollen maturation prior to anthesis. Premature drying of developing pollen confirmed that the accumulation of LLA23 transcripts was associated with desiccation. The LLA23 proteins decreased their levels when pollen/pollen tubes grew in the germination buffer. Treatments of pollen with abscisic acid (ABA) and polyethylene glycol (PEG)-8000 during germination greatly retarded the disappearance of LLA23 proteins and mRNAs. The LLA23 transcripts decreased their levels in pollen tubes grown both in vitro and in vivo, but the disappearance of LLA23 transcripts in tube cells grown in vivo was slower than those grown in vitro. In situ localization using anti-chicken immunoglobulin G conjugated with gold particles confirmed that LLA23 was located in the cytoplasm of pollen grains. The protective function of the desiccation-related proteins in the cytoplasm of pollen grains is proposed.

Amino Acid Sequence↗