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Biomedical subjects

S C Wu

Publications and source records attributed to S C Wu.

At least 55 records · Page 3Linked to original sources
PubMed2000

Myocardial-directed overexpression of the human beta(1)-adrenergic receptor in transgenic mice.

The beta(1)-adrenergic receptor (AR) is the dominant subtype in non-failing and failing myocardium. beta(1)-AR signaling, by the endogenous neurotransmitter norepinephrine, is central to the regulation of myocardial contractility. In heart failure, the beta(1)-AR undergoes subtype-selective downregulation which may protect against the increased cardiac adrenergic drive associated with this pathophysiological state. To examine the hypothesis that chronically increased beta(1)-AR mediated signaling has adverse myocardial effects, transgenic mice overexpressing the human beta(1)-AR in a cardiac-selective context were produced, utilizing an alpha-myosin heavy chain (MHC) promoter. In these mice, beta(1)-AR protein abundance was approximately 24-46-fold (1-2 pmol/mg protein) that of wild-type mice. Histopathological examination of young (4 months old) and old (approximately 9 months old) transgenic mouse hearts consistently demonstrated large areas of interstitial replacement fibrosis, marked myocyte hypertrophy and myofibrilar disarray. In addition, increased expression of the pre-apoptotic marker, Bax, was observed coincident with regions of fibrosis accompanied by an increased apoptotic index, as measured by TUNEL assay. Older non-transgenic mice exhibited a slight tendency towards a decreased fractional shortening, whereas older beta(1)-AR transgenic mice had a marked reduction in fractional shortening (%FS approximately 30) as determined by echocardiography. Additionally, older beta(1)-AR transgenic mice had an increased left ventricular chamber size. In summary, cardiac-directed overexpression of the human beta(1)-AR in transgenic mice leads to a significant histopathological phenotype with no apparent functional consequence in younger mice and a variable degree of cardiac dysfunction in older animals. This model system may ultimately prove useful for investigating the biological basis of adrenergically-mediated myocardial damage in humans.

Animals↗
PubMed2000

The agreement between self-reporting and clinical diagnosis for selected medical conditions among the elderly in Taiwan.

A cross-sectional survey was conducted to consider whether there is agreement between self-report and clinical diagnosis in the prevalence of selected common chronic diseases among elderly Taiwanese. Between July 1992 and June 1993, both face-to-face interview and clinical evaluation were applied to a sample of 228 Taiwanese aged 65 y and older to estimate the prevalence of heart diseases, hypertension and diabetes. The results showed that a self-reported history of diabetes had the highest sensitivity (66. 7%) and specificity (95.2%). The self-report of heart diseases was the least sensitive (20.5%), while self-reports of hypertension was the least specific (82.8%). Multivariate analyses showed that age, education and number of self-reported diseases suffered from, appeared to influence the accuracy of the self reported data. Our data suggest a notable lack of agreement abetween self-report and clinical diagnosis for medical conditions, even for those with clear and unambiguous diagnostic criteria. The elderly in Taiwan tended to under report (with a consistently higher false negative rate than false positive rate) the existence of the three selected medical conditions. This was especially so for heart diseases. Our findings suggest that, if the level of disease prevalence in the population needs to be known for health planning estimates for hypertension and diabetes would not necessarily be a problem. However, the prevalence for heart disease would be seriously under-estimated. We also argue that information obtained by self-report should be validated before use, especially in the case of assessment of the prevalence of medical conditions in the elderly.

Aged↗
PubMed2000

The enhancement methods for the degradation of TCE by zero-valent metals.

Batch tests were performed to compare the degradation rates of TCE on Fe0 and Zn0. Our results indicated that the degradating capability of Zn0 to TCE was nearly 10 times higher than that of Fe0. On the other hand, the degradation rates of Fe0 or Zn0 in conjunction with other metals for reduction of TCE was investigated. The selected metals were nickel (Ni0) and palladium (Pd0) both of which have a strong enhancement effect. The reduction rates of Zn0/Pd0 and Zn0/Ni0 for TCE were the fastest. Fe0 that had lost its surface activity could be activated again by the addition of Pd0 or Ni0.

Ethane↗
PubMed2000

Serum and milk lactoferrin concentration and the correlation with some blood components in lactating sows.

An increased serum concentration of lactoferrin is associated with inflammatory disease, but there are few reported data on this aspect for lactating sows. Samples of blood and milk were collected from 17 lactating sows under minimum stress conditions and analysed for lactoferrin. Lactoferrin concentrations in serum and milk were positively correlated, being high after farrowing and steadily decreasing throughout 28 days of lactation. A positive linear correlation was observed between lactoferrin concentration and enzyme activities of alanine aminotransferase, lactate dehydrogenase, and hydroxybutyrate dehydrogenase in the serum indicating post-partum inflammation. Serum and milk lactoferrin concentrations, although closely correlated, may be regulated through independent systems activated simultaneously.

Alanine Transaminase↗
PubMed2000

Genetic analysis and clinical evaluation of vacuolating cytotoxin gene A and cytotoxin-associated gene A in Taiwanese Helicobacter pylori isolates from peptic ulcer patients.

The aims of this study were to investigate the cytotoxin-associated gene A (cagA) and vacuolating cytotoxin gene A (vacA) subtype in Taiwanese H. pylori isolates from patients with gastroduodenal diseases and to assess the relationship between genotypes of isolates and clinical features. The vacA s1a allele was found in all isolates and vacA m1 allele was found in 15% of isolates. The cagA gene was found in 82.5% of isolates. The vacA s1a/m2 strains had a significantly higher prevalence rate than vacA s1a/m1 strains in Taiwan (p < 0.05). By aligning and comparing the nucleotide and amino acid sequences of vacA from the Taiwanese isolates, the signal sequence and N-terminal region were found to be highly conserved, but the middle region was found to be highly heterogeneous. Determining the relationship between the genotypes and clinical features, we found that the cagA gene was more closely associated with duodenal ulcer than with gastric ulcer and the vacA s1a/m2 strain was more closely associated with active chronic gastritis and atrophic gastritis than with chronic gastritis. Together, our results indicated that (i) the middle region of vacA gene in Taiwanese isolates was heterogeneous; (ii) s1a/m2 vacA strains had a high prevalence in Taiwanese peptic ulcers; and (iii) the cagA gene was significantly associated with duodenal ulcer.

Acute Disease↗
PubMed2000

Topiramate as add-on therapy: pooled analysis of randomized controlled trials in adults.

PURPOSE: Six double-blind, placebo-controlled trials were conducted with topiramate (TPM) initiated as adjunctive therapy in adults with treatment-resistant partial-onset seizures with or without secondary generalization. METHODS: Because protocols and study populations were similar, data from the studies were pooled and analyzed for 527 patients treated with TPM and 216 treated with placebo. RESULTS: Seizures were reduced > or =50% in 43% of TPM-treated patients and in 12% of placebo-treated patients (p < 0.001); 5% of TPM-treated patients, but no placebo-treated patients, were seizure free during 11-19 weeks of double-blind treatment (p < 0.001). The therapeutic effect was consistent regardless of seizure type, age, gender, baseline seizure rate, or concomitant antiepileptic drug (AED). With 100 mg/day TPM as a starting dosage and weekly dosage increments of 100-200 mg/day added to maximally tolerated dosages of AEDs, the most common treatment-emergent adverse events (TEAEs) were dizziness, somnolence, fatigue, psychomotor slowing, nervousness, paresthesia, ataxia, memory difficulty and speech problems. These central nervous system effects were generally mild to moderate in severity, usually occurred early in treatment, often during titration, and resolved with continued treatment. Other notable TEAEs were weight loss and, in a small percentage of patients, renal calculi.

Adolescent↗
PubMed2000

Longest held occupation in a lifetime and risk of disability in activities of daily living.

OBJECTIVES: To examine the association between the longest held occupation in a lifetime and risk of disability in activities of daily living (ADL) among elderly people (65 years and older) in northern Taiwan. METHODS: A case-control design was used nested within two cohorts of a total of 2198 elderly people who had been followed up either between 1993 and 1997 or between 1996 and 1997. Cases were 360 elderly people with ADL disability within the study period. For each case, two sex matched controls were randomly sampled from the pool of elderly people free from ADL disability. Occupational data were collected through interviews conducted in 1997. Performed job contents were classified into occupational categories and occupation based social classes. Unconditional logistic regression techniques were used to estimate relative risk and 95% confidence intervals (95% CIs) of ADL disability. RESULTS: Compared with people who were former legislators, government administrators, or business executives and managers, workers in agriculture, animal husbandry, forestry, or fishing (odds ratio (OR) 1.9, 95% CI 1.1 to 3.5) and workers in craft and related trades (OR 1.9, 95% CI 1.1 to 3.4) had significantly increased risks of subsequent ADL disability. Differential risks of ADL disability were found across social classes, with a significant dose-response trend in which unskilled blue collar workers had an 1.8 times higher risk of ADL disability than higher social classes of white collar workers. CONCLUSIONS: After adjustment for education, there was still an inverse relation between risk of ADL disability and social class. Although total control for all the known risk factors for ADL disability among elderly people was impossible, the results tend to suggest a potential for an effect of longest held occupation in a lifetime on risk of ADL disability.

Activities of Daily Living↗
PubMed2000

split ends encodes large nuclear proteins that regulate neuronal cell fate and axon extension in the Drosophila embryo.

split ends (spen) encodes nuclear 600 kDa proteins that contain RNA recognition motifs and a conserved C-terminal sequence. These features define a new protein family, Spen, which includes the vertebrate MINT transcriptional regulator. Zygotic spen mutants affect the growth and guidance of a subset of axons in the Drosophila embryo. Removing maternal and zygotic protein elicits cell-fate and more general axon-guidance defects that are not seen in zygotic mutants. The wrong number of chordotonal neurons and midline cells are generated, and we identify defects in precursor formation and EGF receptor-dependent inductive processes required for cell-fate specification. The number of neuronal precursors is variable in embryos that lack Spen. The levels of Suppressor of Hairless, a key transcriptional effector of Notch required for precursor formation, are reduced, as are the nuclear levels of Yan, a transcriptional repressor that regulates cell fate and proliferation downstream of the EGF receptor. We propose that Spen proteins regulate the expression of key effectors of signaling pathways required to specify neuronal cell fate and morphology.

Amino Acid Sequence↗
PubMed2000

Comparison of colony lift with direct spotting methods of blot preparation on the effect of colony hybridization in the detection of environmental organisms.

Nucleic acid probes are used on site to detect or to identify individual microbial cells without cultivation. This molecular technique can avoid some limitations of traditional identification methods including time consuming and imprecise. This study examined the factors affecting colony hybridization and compared the effectiveness of membrane prepared by colony lifting with direct spotting procedures using the universal probe Eub 338. The results of hybridization varied depending on the type of colony morphology. For dry and rough colonies, colony hybridization was not suitable for detecting Acinetobactersp. (CK2A, CK2B), Alcaligenes sp. (TH11 B), Xanthomonas sp. (TH7B), Arthrobacter globiformis (CCRC 10598) and Microbacterium sp. (CCRC 11036). Colonies of Acinetobacter sp. (CCRC 15425) and Alcaligenes spp. (CCRC 10828, H) on agar and membrane were thick and raised, and their detection signals of hybridization were diffused or blank. Colonies of Alcaligenes sp. (CM7A, ANV2) and Acinetobacter sp. (ANV8) isolated from the sludge of biological processes treating ABS wastewater were flat and smooth, and their hybridization signals were clear. For those strains suitable for colony hybridization, the colony blots prepared by colony lift and direct spotting procedures gave the same sensitivity for colony hybridization.

Bacteria↗
PubMed2000

Weight-correction formula for maternal serum screening for Down syndrome in Taiwan.

BACKGROUND AND PURPOSE: This study examined the relationship between maternal weight and serum marker concentrations (alpha-fetoprotein [AFP] and human chorionic gonadotropin [hCG]) to develop a weight-correction formula for second-trimester Down syndrome screening in Taiwan. METHODS: We conducted a prospective observational study based on data from 18, 016 pregnant Taiwanese women who participated in a second-trimester Down syndrome screening program at Taiwan Adventist Hospital. The relationship between maternal weight and the multiple of median (MoM) concentrations of serum markers was analyzed using two methods; one involved all the observational data (all point method), while the other involved only the median concentrations at various gestational ages (median regression method). In each method, several statistical approaches were used, including simple-linear, reciprocal, quadratic, and log-transformation linear regression. RESULTS: The correlation between maternal body weight and serum marker concentrations using the all point regression method was very poor, while the median regression method achieved a good fit. The reciprocal regression analysis had the best fit between AFP MoM concentration and maternal weight, while the best fit between hCG MoM concentration and maternal weight was achieved with quadratic regression analysis. CONCLUSION: The present study has developed a race-specific weight-correction formula for Taiwanese women. This formula is expected to be helpful in second-trimester Down syndrome screening programs in Taiwan.

Adolescent↗
PubMed1999

Development of improved pUB110-based vectors for expression and secretion studies in Bacillus subtilis.

pUb110-based vectors are commonly used for expression and secretion studies in Bacillus subtilis. Two of these plasmids, pUB18P43 and pWB705, have been applies to produce several proteins of interest. To offer greater flexibility and compatibility in this system, the authors have also constructed a pE194-based plasmid vector (pE18). To determine whether the pUB110-based or the pE194-based vector serves as a better expression system, three structural genes encoding cytoplasmic BirA, extracytoplasmic PrsA and extracellular staphylokinase, respectively, were used as models. Production of these products using pUB110-based vectors was consistently 2--3-fold lower than that using the pE194-based vectors. The observed difference in the protein yield did not result from either the rearrangement of the plasmid or the difference in the plasmid copy number. By using three different approaches, the lower production yield from the pUB110-based vectors was found to be due to the transcription interference from the plasmid encoded genes. These findings illustrate that the orientation of the inserted gene in pUB110-based vector can greatly affect gene expression. Two new expression vectors, pUB19P43 and pWB980, were constructed to allow better gene expression.

Bacillus subtilis↗
PubMed1999

A double-blind, randomized trial of topiramate as adjunctive therapy for partial-onset seizures in children. Topiramate YP Study Group.

OBJECTIVE: To evaluate the efficacy and safety of topiramate 6 mg/kg/day in children (age 2 to 16 years) as adjunctive therapy for uncontrolled partial-onset seizures with or without secondarily generalized seizures in a multicenter, randomized, double-blind, placebo-controlled trial. METHODS: Patients with at least six partial-onset seizures during the 8-week baseline phase were treated with either topiramate (n = 41) or placebo (n = 45) for 16 weeks. RESULTS: Topiramate-treated patients had a greater median percent reduction from baseline in average monthly partial-onset seizure rate than placebo-treated patients (33.1% versus 10.5%, p = 0.034), a greater proportion of treatment responders (i.e., patients with a > or = 50% seizure rate reduction; 16 of 41 [39%] versus 9 of 45 [20%], p = 0.080), and patients with a > or = 75% seizure rate reduction (7 of 41 [17%] versus 1 of 45 [2%], p = 0.019), and better parental global evaluations of improvement in seizure severity (p = 0.019). Emotional lability (12% versus 4%), fatigue (15% versus 7%), difficulty with concentration or attention (12% versus 2%), and forgetfulness/impaired memory (7% versus 0%) were more frequent among topiramate-treated than placebo-treated patients. Most treatment-emergent adverse events were mild or moderate in severity. No topiramate-treated patients discontinued the study due to adverse events. CONCLUSIONS: Topiramate was safe and effective in the treatment of partial-onset seizures in children.

Adolescent↗
PubMed1999

Fyn associates with Cbl and phosphorylates tyrosine 731 in Cbl, a binding site for phosphatidylinositol 3-kinase.

We have investigated the interaction between Cbl and the Src-related tyrosine kinase Fyn. Fyn was observed to be constitutively associated with Cbl in lysates of several different cell types including the interleukin-3-dependent murine myeloid cell line 32Dcl3, and the prolactin-dependent rat thymoma cell line Nb2. Binding studies indicated that Cbl could bind to glutathione S-transferase (GST) fusion proteins encoding the unique, Src homology domain 3 (SH3), and SH2 domains of Fyn, Hck, or Lyn. Fusion proteins encoding either the SH3 or SH2 domains of Fyn bound to Cbl as effectively as the fusion protein encoding the unique, SH3, and SH2 domains of Fyn. The Fyn SH2 domain bound to both tyrosine-phosphorylated and nonphosphorylated Cbl, implying that this interaction might be phosphotyrosine-independent. Binding of the Fyn SH2 domain to Cbl was not disrupted by the addition of phosphotyrosine, phosphoserine, or phosphothreonine. A GST fusion protein encoding the proline-rich region of Cbl bound to Fyn present in a total cell lysate. Far Western blot analysis also indicated that the SH3 domain of Fyn bound preferentially to the proline-rich region of Cbl. The addition of [gamma-32P]ATP to either anti-Cbl immunoprecipitates or anti-Fyn immunoprecipitates resulted in the phosphorylation of both Cbl and Fyn as demonstrated by immunoprecipitation of the phosphorylated proteins with specific antisera. Fyn directly phosphorylated a GST fusion protein containing the C-terminal region of Cbl (GST-CBL-LZIP). In contrast, immunoprecipitated JAK2 was not able to phosphorylate this same region of Cbl. The GST-CBL-LZIP fusion protein contains a binding site for the SH2 domain of the p85 subunit of phosphatidylinositol 3-kinase, which mapped to Tyr731, which is present in the sequence YEAM. Mutation of Tyr731 in GST-CBL-LZIP eliminated binding of the p85 subunit of phosphatidylinositol 3-kinase and substantially reduced the phosphorylation of this fusion protein by Fyn, despite the presence of four other tyrosine residues in this fusion protein. These data are consistent with the hypothesis that Cbl represents a substrate for Src-like kinases that are activated in response to the engagement of cell surface receptors, and that Src-like kinases are responsible for the phosphorylation of a tyrosine residue in Cbl that may regulate activation of phosphatidylinositol 3-kinase.

Animals↗
PubMed1999

Stress, social relations, and old age mortality in Taiwan.

The research analyzed the relationships among stress, social relations, and mortality in a probability sample of 4,049 Taiwanese adults, aged 60 and over. The baseline survey was conducted in 1989 and the survival status of the respondents was ascertained during the subsequent 4 years. Death of a spouse or a child was found to increase the risk of dying directly and indirectly, whereas major financial difficulty during the past 5 years and current financial strain influenced mortality indirectly through their effects on self-rated health disability. In addition to their direct effect on mortality, martial status and work status lowered the probability of dying through decreased disability and subjective ill health. Finally, no buffering effects of social support were substantiated.

Adaptation, Psychological↗
PubMed1999

The effectiveness of acupressure in improving the quality of sleep of institutionalized residents.

BACKGROUND: Elderly people often suffer from disturbed sleep. Because traditional Chinese medicine indicates that acupressure therapy may induce sedation, testing the effectiveness of acupressure in enhancing the quality of sleep of institutionalized residents with a well-designed scientific study is needed. METHODS: A randomized block experimental design was used. The Pittsburgh Sleep Quality Index (PSQI) questionnaire was used as a screening tool to select subjects with sleep disturbance. By matching the effects of hypertension, hypnosis, naps, and exercise, subjects were randomly assigned to an acupressure group, a sham acupressure group, and a control group. Each group had 28 subjects for a total of 84 subjects. The same massage routine was used in the acupressure group and the sham acupressure group, whereas only conversation was employed in the control group. RESULTS: There were significant differences in PSQI subscale scores of the quality, latency, duration, efficiency, disturbances of sleep, and global PSQI scores among subjects in the three groups before and after interventions. Furthermore, there was a significant reduction in the frequencies of nocturnal awakening and night wakeful time in the acupressure group compared to the other two groups. CONCLUSIONS: This study confirmed the effectiveness of acupressure in improving the quality of sleep of elderly people and offered a nonpharmacological therapy method for sleep-disturbed elderly people.

Acupressure↗
PubMed1999

Incidence of and predictors for chronic disability in activities of daily living among older people in Taiwan.

OBJECTIVES: To estimate the incidence of chronic activities of daily living (ADL) disability and to analyze the sociodemographic, health status, adverse lifestyle, and leisure-time physical activity predictors for chronic ADL disability. DESIGN: We recruited a cohort of community-dwelling older people in Taipei, Taiwan, who were not ADL disabled in August 1993, and we followed them until August 1996. SETTINGS AND PARTICIPANTS: The study subjects were 1321 community-dwelling people aged 65 years or older who were ADL intact at the initial interview in August 1993. The study sample was a subset of a probability sample (n = 1583) randomly selected from household registrations in the four districts of the Taipei metropolitan area. MEASUREMENTS: Baseline information regarding various factors potentially associated with the development of chronic ADL disability was assessed and collected at the beginning of the study. Study participants were assessed annually for ADL function by a structured home interview using a six-item scale. Participants who were unable to perform independently at least one of the six items--eating, bathing, dressing, toileting, transfers, and walking inside the house--for more than 3 months were considered chronically ADL disabled. Cox proportional hazard regression models were utilized to examine the independent effect of the potential predictors on risk of chronic ADL disability. RESULTS: During the 3-year study period, 145 (11.0%) participants developed chronic ADL disability, 58 (4.4%) participants were lost to follow-up, and 83 (6.3%) participants died. Multiple hazard regression analysis showed that individuals aged 70 to 79 years or older than age 80 had increased risk of ADL disability (relative risk: 2.05 (95% confidence interval (CI), 1.35-3.11) and 3.89 (95%CI, 2.33-6.50), respectively) compared with those participants younger than age 70. Risk of chronic ADL disability was inversely associated with routine exercise (RR = 0.52; 95% CI, 0.39-0.68). CONCLUSIONS: Age is the most significant predictor of chronic ADL disability. Lack of routine exercise is also a significant predictor of ADL disability in older adults.

Activities of Daily Living↗
PubMed1999

Effects of cognitive impairment and loss of physical capacities on survival of the elderly.

This study investigates the effects of cognitive impairment and loss of physical capacity on the survival rates of the elderly in Taiwan. Data used for this research were obtained from a longitudinal study in northern Taiwan, where 1,434 elderly respondents were randomly selected and were interviewed in 1993 and 1996. Respondents were categorized into four groups: those with physical disability, those with cognitive impairment, those with neither condition and those with both conditions. The survival rates of these four groups were analyzed and compared. The effects of cognitive impairment and physical disability were assessed separately and jointly. Within the study period, we found that elderly persons with both conditions had the lowest survival rate (0.54, 95% confidence interval (CI) 0.35-0. 73), while those with neither condition had the most favorable survival rate (0.92, 95% CI 0.90-0.93). Results from the Cox proportional hazard model showed that physical disability had a significantly adverse effect on the risk of mortality (relative risk 2.5, 95% CI 1.5-4.2), while cognitive impairment did not. Our results are consistent with previous findings which have shown that the decline in physical function affects mortality more than the decline in cognitive function.

Activities of Daily Living↗