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Biomedical subjects

M C Wu

Publications and source records attributed to M C Wu.

At least 109 records · Page 6Linked to original sources
PubMed1989

Retrospective analysis of 97 patients with infective endocarditis seen over the past 8 years.

The medical records of 97 consecutive patients (101 episodes) of infective endocarditis seen from January 1979 through January 1987 were reviewed. Only 30% of the patients were over 50 years of age and the majority (69%) of infecting organisms were streptococci (mainly of the viridans group), which were similar to those reported from the West in the early antibiotic era. Pseudomonas organisms and enterococci accounted for 6% and 5%, respectively. Fungal infections were noted in 2 patients. There was a high incidence (38%) of predisposing rheumatic valvular disease; approximately half of these patients had prosthetic valve infections. Mitral valve prolapse was also an important predisposing disease (11%). One-third (34%) of the patients had febrile illness for longer than 8 weeks before the diagnosis was established. The hospital morality rate was 22%; cerebral embolism and ruptured mycotic aneurysm, congestive heart failure, and sudden death were the major causes of death. Echocardiography disclosed vegetations on the cardiac valves and preexisting lesions in 75% of the episodes. Early recognition and proper treatment should be the focus of efforts to reduce mortality from infective endocarditis.

Adolescent↗
PubMed1989

The response pattern of patients with chronic airway obstruction to bronchodilators.

To investigate the response pattern of patients with chronic airway obstruction (CAO) to bronchodilators, 128 subjects consisting of 80 men and 48 women with a mean age of 52.6 years were randomly tested with three inhalant bronchodilators: a non-selective beta-agonist (isoproterenol), a beta 2-selective agonist (terbutaline) and an anticholinergics (ipratropium) plus placebo. All patients had a baseline FEV/FVC of less than 65% and their clinical diagnosis were classified as either COPD or bronchial asthma according to the criteria of the ACCP-ATS Joint Committee on Pulmonary Nomenclature. The drugs were delivered to the patient via a metered dose inhaler (MDI) using the conventional inhalation technique. Spirometry was measured at regular intervals with a computerized pulmonary function analyzer CHESTAC-65(Japan). A more than 15% increase in FEV1 and/or FVC after treatment was regarded as responsive. While 108 patients were tested with a single drug, the remaining 20 patients were tested sequentially with terbutaline, ipratropium and placebo in a randomized cross-over manner for studying additivity. Our results showed that the response rates of asthmatic patients to isoproterenol, terbutaline and ipratropium were 50%, 87% and 67%, respectively. Only 27% of COPD patients responded to isoproterenol and 60% to terbutaline. On the other hand, ipratropium possessed a 61% response rate in the treatment of COPD and showed a bronchodilator effect independent to that of terbutaline. Combined use of both drugs resulted in additional improvement. Once patients responded to the drugs, apparent changes in FEV1 and/or FVC occurred within 30 minutes and reached the maximum usually at 60 minutes post-inhalation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Simultaneous assay for individual sulphated 3 alpha- and beta-hydroxysteroids in serum using high-performance liquid chromatography combined with 3 alpha- and beta-hydroxysteroid dehydrogenases immobilized on one column.

A high-performance liquid chromatographic method for the simultaneous determination of individual sulphated 3 alpha- and beta-hydroxysteroids in serum using 3 alpha- and beta-hydroxysteroid dehydrogenases (3 alpha-HSD and beta-HSD, respectively) immobilized on one column and a fluorimeter to detect the resulting NAD+ to NADH transformation is described. Individual sulphated 3 alpha- and beta-hydroxysteroids in serum are extracted with ethanol, solvolysed with sulphuric acid in ethyl acetate and then separated by high-performance liquid chromatography. The hydroxysteroids thus separated are subsequently mixed with NAD+ and then passed through the column in which the following catalytic reaction occurs: (formula, see text) The detection limits are as low as 0.5-1.0 microgram/dl for sulphated 3 alpha- or beta-hydroxysteroids in serum. The present assay method is highly specific, reliable and reproducible and is thus applicable to a clinical study on the metabolism of sulphated 3 alpha- and beta-hydroxysteroids in patients with adrenal or gonadal diseases.

3-Hydroxysteroid Dehydrogenases↗
PubMed1988

Occupational asthma due to toluene diisocyanate among velcro-like tape manufacturers.

During September-November, 1985, four employees of a factory were seen at the occupational clinic complaining of cough, shortness of breath, and wheezing. All four worked in the same area of the factory where an adhesive containing toluene diisocyanate (TDI) was applied to velcro-like tape during manufacturing. To confirm the diagnosis of TDI-induced asthma and determine the prevalence among workers, 38 workers were interviewed and examined (84%) in the factory. Air samples were also taken from several areas in the factory to determine the TDI concentration. For analysis, the factory was divided into three areas based on the concentration of TDI: low (0.012 +/- 0.002 ppm), medium (0.021 +/- 0.006 ppm), and high (0.047 +/- 0.054 ppm). The distribution of workers with symptoms of asthmatic bronchitis was highly associated with TDI concentration (p less than 0.001). After stopping work for a period of 10 days, workers in areas with a high concentration of TDI showed marked improvement in pulmonary function tests (PFTs). After isolation of the exposure site, improvement of the ventilation system, and substitution of the TDI with less volatile diphenylmethane diisocyanate (MDI), air concentration of isocyanates was usually below 0.007 ppm. Three of the four clinically overt asthma cases went back to work without any difficulty. The PFTs of affected workers showed a significant improvement 5 months later. We conclude that TDI was responsible for the occupational asthma among velcro-like tape manufacturers and that the TDI-induced impairment of pulmonary functions was at least partially reversible.

Adhesives↗
PubMed1988

Association between BoLA and subclinical bovine leukemia virus infection in a herd of Holstein-Friesian cows.

The role of the bovine major histocompatibility system (BoLA) in subclinical bovine leukemia virus (BLV) infection was investigated in a herd of Holstein-Friesian cows (n = 240). The BoLA W8.1 allele was negatively associated with the presence of antibodies to the major BLV envelope glycoprotein, BLV-gp51 (corrected P less than 0.001, relative risk = 0.31). These results suggest that a BoLA-linked gene(s) may influence the early spread of BLV infection. Since B cells are the primary target of BLV infection, we then determined the relationship between BoLA-A locus phenotypes and B-cell numbers in peripheral blood of seropositive and seronegative cows. There were no significant differences between BoLA-A alleles for any hematological parameter in seronegative cows. Seropositive cows with the W12.1 allele had significantly greater absolute numbers of lymphocytes per microliter and B cells per microliter than did seropositive cows with other BoLA-A phenotypes (P less than 0.01, respectively). The average effect associated with the W12.1 allele in BLV-infected cows was an increase of 2010 B cells per microliter of whole blood relative to BLV-infected cows with other BoLA-A phenotypes. These results demonstrate that susceptibility to the polyclonal expansion of BLV-infected B lymphocytes is associated with the W12.1 allele in Holstein-Friesian cattle. Compared with results of a previous study in a herd of Shorthorn cattle, it appears that resistance and susceptibility to subclinical progression of BLV infection are associated with different BoLA-A locus alleles in different cattle breeds.

Animals↗
PubMed1988

Sample size for comparison of changes in the presence of right censoring caused by death, withdrawal, and staggered entry.

In estimating and comparing the rates of change of a continuous variable between two groups, the unweighted averages of individual simple least-square estimates from each group are often used. Under the linear random effects model, these statistics are maximum likelihood estimates for the expected rates of change when all individuals have complete observations. However, death and withdrawal often cause observations on the variable of interest to be right censored for some participants, which makes any subsequent measurements impossible (to be referred to as right censoring). In this situation, the unweighted averages are no longer efficient in comparison with the generalized least-square estimates. Relationship between sample size, frequency of measurement, and right censoring are described for the different estimation procedures. Using realistic estimates of the random effect parameters, we illustrate that if there were 8% right censored observations each year due to participants' death or loss to follow-up, the sample size requirements for a proposed 3-year controlled clinical trial of alpha 1-protease inhibitor replacement therapy could be more than doubled if the unweighed rather than the generalized least-square estimates were used.

Clinical Trials as Topic↗
PubMed1988

Lung function, smoking and survival in severe alpha 1-antitrypsin deficiency, PiZZ.

Lung function, smoking, age and mortality data in 158 adult severe alpha 1-antitrypsin deficient, PiZZ individuals, followed from 1963 to 1982 were analyzed. Low initial FEV1 value was significantly associated with increased mortality (p less than 0.005). A 3 yr mortality rate of 40% was found in individuals whose initial FEV1 values were less than 30% of that predicted. In contrast, the corresponding 3-yr mortality among those whose initial FEV1 values were between 30 and 65% of that predicted was only 7%. Smokers were found to have significantly lower FEV1 levels (p = 0.008) and higher mortality (p less than 0.005) than non-smokers. The difference between current and ex-smokers in mortality and FEV1 level were not statistically significant (p = 0.9 and p greater than 0.25, respectively). Cross-sectional analysis of the initial FEV1 values indicated a significant decline (p less than 0.005) of FEV1 with increasing age. This decline was greater among smokers than non-smokers. Longitudinal analysis of FEV1 rates of decline in 80 cases with follow-up FEV1 measurements failed to detect any significant differences between smokers and non-smokers, but was performed late in the disease process. The application of these results to the planning of studies on replacement therapy, smoking intervention strategy and longitudinal follow-up is discussed.

Adolescent↗
PubMed1988

Ovarian influence on uterine growth in prepubertal gilts.

A determination of age of the prepubertal gilt at which ovaries affect uterine growth is necessary before establishing the extent to which length of uterus is influenced by inherent differences, as opposed to those due to ovarian secretions. In Exp. 1 and 2, the effect of presence of ovaries on uterine growth was determined following ovariectomy in 186 crossbred gilts. The uterus was examined 40 or 80 d after ovariectomy for length, weight and diameter. Growth of uterine horns in gilts from 20 to 60 d of age was equal with or without ovaries. Uterine horns in ovariectomized gilts continued to grow slowly from 60 to 140 d of age and then remained static to 180 d of age. Uterine horns in gilts with ovaries increased rapidly in length, weight and diameter, with concomitant increase in ovarian weight between 100 and 180 d of age. In Exp. 3, uterine growth and ovarian compensation after unilateral ovariectomy and hysterectomy at 60 d of age were determined in 85 crossbred gilts from 60 to 180 d of age to evaluate the unilateral ovariohysterectomy model for studying association of uterine length before puberty and subsequent uterine capacity. In response to removal of an ovary and a uterine horn, the remaining ovary compensated, but the remaining uterine horn did not. This study demonstrated that the ovaries did not influence uterine growth until after 60 d of age and that unilateral ovariohysterectomy could be performed as early as 60 d of age without altering consequent normal uterine growth.

Animals↗
PubMed1988

Effect of stage of gestation, litter size and uterine space on the incidence of mummified fetuses in pigs.

Factors associated with incidence of mummified fetuses at 7, 9, 11, 13 and 15 wk of gestation were determined in a cross-sectional design involving 209 pregnant pigs. Percentage of observed mummies increased from 2.1 to 12.2% as gestation progressed. Incidence of mummies at 7 wk of gestation was not different between litters of nine fetuses or fewer and those of 10 fetuses or more. During the period of 7 to 15 wk of gestation, the incidence of mummies remained constant at about 1% in litters of nine fetuses or fewer, whereas in litters of 10 fetuses or more the incidence increased linearly from 1 to 12% (P less than .01). In litters of nine fetuses or fewer, a mummy occupied no less space than a live fetus until 13 wk of gestation. In litters of 10 fetuses or more, a mummy occupied less space than did a live fetus after 7 wk of gestation. An increase in the incidence of mummies in larger litters was associated with uterine space per fetus below that needed for development and survival. The 12% fetal loss in late gestation was associated with less uterine space per fetus. Length of uterine horns, litter size and stage of gestation together accounted for 12% of the variation in incidence of mummies (P less than .001). A longer uterus had greater space per fetus, a larger number of live fetuses and a lower incidence of mummies.

Animals↗
PubMed1988

Procedures for measuring length of the pig uterus.

A method for measuring uterine length in pigs was standardized following a series of experiments to determine the effect of period of storage, temperature, presence of ligaments and the nature of the surrounding fluid on the length of the uterus. Weight of the uterus did not change during storage. Measurements in vivo were compared with those in vitro. The uterus shortened immediately after its removal, then gradually lengthened over 8 h. Whereas there was change in absolute measured length during the storage period, the relationship of length in vivo was significantly correlated to length in vitro (r = .85, P less than .001). Measurement at one time during storage was highly correlated with measurement at other times (r = .93 to .96). The coefficient of variation for length of uteri among gilts was 30%. Measurement of length of the uterus must be done under uniform conditions of storage to give meaningful results.

Animals↗
PubMed1988

Influence of pig embryos on uterine growth.

The influence of embryos on growth of the uterus was determined by comparing uterine length, weight and diameter between gravid and nongravid horns within unilaterally pregnant gilts. Eighty-two prepubertal gilts were ovariectomized unilaterally at 5 mo of age, and the ipsilateral uterine horn was ligated near the junction of the uterine horns. Gilts were mated and were assigned randomly for examination on either d 9, 12, 15, 18, 21, 24 or 27 of gestation. Absolute differences and ratios in length, weight and diameter between gravid and nongravid horns of unilaterally pregnant gilts were analyzed. The gravid horn was 40% longer than the nongravid horn from d 18 to 27. Uterine horns with embryos increased linearly in weight and diameter (P less than .01) between d 15 and 27. Embryos, or the signals that they might give, apparently caused increases in length, weight and diameter of the uterine horn by d 18, but not before.

Animals↗
PubMed1988

Peripheral B lymphocyte percentage as an indicator of subclinical progression of bovine leukemia virus infection.

The relationship between percentage of B cells in peripheral blood and subclinical bovine leukemia virus infection was examined in a herd of 240 Holstein-Friesian cows. Absolute leukocyte count and absolute lymphocyte count were significantly positively correlated with B cell percentage in cows that were seropositive to bovine leukemia virus envelope glycoprotein, but these parameters were not correlated in seronegative cows. The B cell percentage was not affected by age. Cows that had persistent lymphocytosis and hematologically normal seropositive cows had greater mean B cell percentages (78 and 45%, respectively) than did seronegative herdmates (37%). To evaluate B cell percentage as a means of detecting subclinical progression of bovine leukemia virus infection, an index was developed based upon the distribution of B cell percentages in seronegative cows. When this index was compared with a standard hematological key (the European Community's Leukosis Key), which is based on absolute lymphocyte count and age, 29% of seropositive, hematologically normal cows had B cell percentages two standard deviations above the mean of their seronegative herdmates. The B cell percentage was thus shown to be more effective than absolute lymphocyte count for detecting subclinical progression of bovine leukemia virus infection in individual cows.

Animals↗
PubMed1988

[Alpha-fetoprotein (AFP) variant in the diagnosis of small liver cancer].

From May 1983 to June 1986, 40 patients with primary liver cancer, less than 5 cm in diameter, were treated by operation. The smallest lesion was 1.4 x 0.9 x 0.4 cm in size. Fifteen patients came to the hospital for treatment due to the finding of AFP greater than or equal to 31 ng/ml by public survey and 8 with space occupying lesion (SOL) in the liver by ultrasonography (US). The serum AFP levels ranged from 0 to 6800 ng/ml in this group with AFP negative in 6 cases, 31-400 ng/ml in 19 and over 400 ng/ml in 15. The positive rate of AFP was 37.5%. US displayed SOL in 25 cases, suspicious SOL in 5 and negative in 10. The positive rate was 62.5% by US. The overall positive rate was 77.5% by AFP and US combined. In addition, AFP variant was determined by LCA affino-crossed-immunoelectrophoresis autoradiography. LCA-nonreactive-AFP varied from 0 to 100% with a mean value of 57.0 +/- 26.7%. Taking less than 75% as diagnostic criterion for liver cancer, the positive rate of LCA-nonreactive-AFP was 65.0%. 12 patients who were AFP variant positive but SOL suspicious or negative were regularly followed by US for 1-20 months. They all showed distinct SOL. Composite results of AFP, AFP variant and US gave a diagnostic rate of 97.5% for small liver cancer. The determination of AFP variant is helpful in early detection of small liver cancer.

Adult↗