Biomedical subjects

S C Wu

Publications and source records attributed to S C Wu.

At least 109 records · Page 6Linked to original sources

PubMed1995

Site dependence of postmortem blood methadone concentrations.

A case investigated by the Office of the Chief Medical Examiner, State of Maryland, identified methadone at a heart blood concentration of 2.4 mg/L and a subclavian blood concentration of 0.8 mg/L. Due to these discrepant results, a study was undertaken to determine whether such inconsistencies occurred in other methadone cases. Of the 15 cases studied, only four had heart blood and alternate blood concentrations within 20% of one another. In only 53% of the cases were variations of < 60% observed. The data failed to show a trend where one site was consistently higher or lower than the other site.

Adult↗

PubMed1995

Human plasma enhances the infectivity of primary human immunodeficiency virus type 1 isolates in peripheral blood mononuclear cells and monocyte-derived macrophages.

Physiological microenvironments such as blood, seminal plasma, mucosal secretions, or lymphatic fluids may influence the biology of the virus-host cell and immune interactions for human immunodeficiency virus type 1 (HIV-1). Relative to media, physiological levels of human plasma were found to enhance the infectivity of HIV-1 primary isolates in both phytohemagglutinin-stimulated peripheral blood mononuclear cells and monocyte-derived macrophages. Enhancement was observed only when plasma was present during the virus-cell incubation and resulted in a 3- to 30-fold increase in virus titers in all of the four primary isolates tested. Both infectivity and virion binding experiments demonstrated a slow, time-dependent process generally requiring between 1 and 10 h. Human plasma collected in anticoagulants CPDA-1 and heparin, but not EDTA, exhibited this effect at concentrations from 90 to 40%. Furthermore, heat-inactivated plasma resulted in a loss of enhancement in peripheral blood mononuclear cells but not in monocyte-derived macrophages. Physiological concentrations of human plasma appear to recruit additional infectivity, thus increasing the infectious potential of the virus inoculum.

Blood↗

PubMed1995

Anti-Nform antibody in hemodialysis patients.

The anti-Nform antibody is produced by dialysis patients following reuse of dialyzers sterilized with formaldehyde and it has been implicated as a cause of hemolytic anemia. Formaldehyde is one of the common disinfectants used for reprocessing capillary hemodialyzers. The safety of formaldehyde and the clinical significance of anti-Nform antibody need further evaluation. Amongst 45 patients practising dialyzer reuse, anti-Nform antibody was detected in 5 (11.1%), but not amongst 111 patients not reusing their dialyzer (p < 0.005). The presence of anti-Nform was not related to the sex, or duration of dialysis with positive anti-Nform antibody. Direct Coombs' test was positive amongst 80% of all tested patients with anti-Nform antibody, and in 38% of patients reusing dialyzers but without anti-Nform antibody. No tests of hemolysis (including direct Coombs' test) discriminated between anti-Nform antibody-positive and -negative patients, nor between anti-Nform antibody patients with and without overt hemolysis. The best diagnostic test for hemolysis in anti-Nform antibody-positive patients was hematocrit rise after cessation of dialyzer reuse. It appears that despite the induction of anti-Nform antibody, hemolysis is rarely a serious consequence of dialyzer reuse.

Adult↗

PubMed1994

An unusual morphine fatality.

A case is presented of a 90-year-old white female who apparently died of natural causes in a nursing home. Subsequent investigation indicated that the decedent had been administered an unauthorized bolus of morphine just prior to her death. The embalmed body was exhumed, an autopsy performed, and specimens were collected for toxicologic analysis. The liver contained 1.5 mg/kg of free morphine as measured by radioimmunoassay. The presence of morphine was confirmed by gas chromatography/mass spectrometry. A review of the literature as well as in-house data collected from narcotic deaths clearly suggest that the morphine measured in this case was consistent with a lethal concentration. The manner of death was homicide.

Aged↗

PubMed1994

Hypokalemic effects of intravenous infusion or nebulization of salbutamol in patients with chronic renal failure: comparative study.

To examine and compare the efficacy and safety of different routes of administration of salbutamol in treating hyperkalemia, 15 patients with chronic renal failure (blood urea nitrogen > 80 mg/dL, serum creatinine > 8.0 mg/dL) were enrolled to sequentially receive either intravenous infusion (0.5 mg) or nebulization (10 mg) of salbutamol. Five of these patients (33.3%) did not respond to the intravenous salbutamol and were excluded from the study. Both treatments significantly decreased plasma potassium in 10 patients and the decrease was sustained for at least 3 hours. After infusion, the maximal reduction in plasma potassium levels was 0.92 +/- 0.10 mEq/L and occurred after 30 minutes. On the other hand, the maximal reduction in plasma potassium after nebulization (0.85 +/- 0.13 mEq/L) was similar to that after infusion, but it occurred after 90 minutes. Insulin and blood glucose increased, whereas blood pH, PCO2, sodium, osmolality, and blood pressure did not change after either treatment. Heart rate increased significantly after both treatments, but less after nebulization than after infusion. It is concluded that both infusion and nebulization are simple, effective, and safe therapeutic modalities for the treatment of hyperkalemia in patients with chronic renal failure. Infusion should be used in patients requiring a rapid decrease in plasma potassium; nebulization, on the other hand, should be used in patients with coronary artery diseases.

Administration, Inhalation↗

PubMed1994

Intravenous infusion or nebulization of salbutamol for treatment of hyperkalemia in patients with chronic renal failure.

BACKGROUND: Hyperkalemia is one of the frequent medical emergencies in patients with chronic renal failure (CRF). We studied and compared the efficacy and safety of salbutamol either by intravenous infusion (i.v.) or nebulization (NB) in treating CRF patients with hyperkalemia. METHODS: Thirty-four patients (BUN > 80 mg/dl, serum creatinine > 8.0 mg/dl, and plasma potassium > 5.0 mEq/L) were randomly assigned to receive either i.v. (0.5 mg) or NB (10 mg) treatment of salbutamol. Plasma potassium, sodium, osmolarity, glucose, insulin, PCO2, blood pH, blood pressure and heart rate were monitored. RESULTS: One third of i.v. group and one fourth of NB group of patients were resistant to salbutamol treatment and were excluded from the study. All the baseline data were similar between 2 groups. After treatment, significant decrease in plasma potassium was found in both groups. The maximal reduction of plasma potassium was 0.95 +/- 0.14 mEq/L and occurred 30 minutes after i.v. treatment (n = 12) while it was 0.88 +/- 0.13 mEq/L and occurred 90 minutes after NB treatment (n = 12). During the first ninety minutes after treatments, the decrease of plasma potassium in IV group was faster and greater than in NB group. After that, the hypokalemic effect was more profound in NB group till the end of the study. The hypokalemic effects of both treatments sustained for at least 3 hours. Plasma insulin and glucose increased (p < 0.05) in both groups, whereas blood pH, PCO2, sodium, osmolarity and blood pressure did not change significantly. The reduction of potassium was significantly correlated with the elevation of insulin (i.v.: r = -0.56, p < 0.05; NB: r = -0.54, p < 0.05). Heart rate elevated significantly in both groups; nevertheless, this elevation was less marked in NB group. CONCLUSIONS: Both routes of administration of salbutamol resulted in a prompt and significant decrease of plasma potassium concentrations and both are considered as simple, effective and safe alternatives in treating hyperkalemia in patients with CRF. However, i.v. therapy might be preferred in CRF patients requiring a rapid lowering in plasma potassium; nebulization, on the other hand, should be preferred in CRF patients with coronary artery diseases.

Administration, Inhalation↗

PubMed1994

Effect of intravenous calcitriol on secondary hyperparathyroidism in chronic hemodialysis patients.

BACKGROUND: It has become evident that calcitriol can suppress parathyroid hormone (PTH) secretion by direct genomic actions. Intravenous calcitriol that bypasses gastrointestinal degradation might cause less degree of hypercalcemia and greater suppressive effect on PTH secretion. We investigated this PTH-suppressive effect of intravenous calcitriol in hemodialysis patients with secondary hyperparathyroidism. METHODS: Calcitriol was administered at the end of each dialysis session three times a week in 20 uremic patients, for 12 weeks. RESULTS: The mean dosage of calcitriol was 2.72 +/- 0.21 microgram per dialysis session. Serum intact PTH and C-PTH decreased (P < 0.05) after 6 weeks of treatment, while serum alkaline phosphatase (Alk-P) decreased 3 weeks later than PTH did. The individual maximal reduction of intact PTH, C-PTH and Alk-P were 77.80%, 67.36% and 45.98%. This PTH-suppression was dose-dependent. Despite the significant reduction of intact PTH by 58.17% after 6 weeks of treatment, no significant increase of serum calcium was found. An increase in serum calcium is not essential for this PTH-suppressive effect of calcitriol. Our observations thus provide another evidence to support the direct inhibitory effect of calcitriol on PTH secretion. Serum calcium, phosphorus, magnesium, albumin and osteocalcin levels did not change significantly. No side effect was found during treatment. CONCLUSIONS: Intravenous calcitriol is effective and safe in treating hemodialysis patients with secondary hyperparathyroidism. This treatment is more important in patients who are intolerant to oral vitamin D supply and who are candidates for surgical parathyroidectomy.

Adult↗

PubMed1994

A fentanyl epidemic in Maryland 1992.

In early 1992, the Office of the Chief Medical Examiner, State of Maryland, encountered 30 cases where fentanyl was identified in the postmortem specimens. Twenty-five of the decedents were found in Baltimore City and five were found in the surrounding counties. Four of the decedents were female and eight of the victims were white. The blood fentanyl concentrations ranged from 2.2 to 100 micrograms/L. Ethanol and other abused drugs were detected in 28 of these cases. The cause of death in all cases was ethanol-, drug intoxication, or both.

Adult↗

PubMed1994

Effectiveness of coenzyme Q10 on myocardial preservation during hypothermic cardioplegic arrest.

A prospective, randomized, double-blind trial assigned 11 patients to receive coenzyme Q10 and 11 to receive none. Patients pretreated with coenzyme Q10 had a lower left atrial pressure and a lesser incidence of low cardiac output. They also had a wider pulse pressure. The right and left ventricular myocardial ultrastructure was better preserved in patients receiving preoperative treatment with coenzyme Q10. There was no demonstrable benefit to the atrial myocardium.

Adult↗

PubMed1993

A randomized clinical trial of induction therapy with OKT3 in kidney transplantation.

A randomized, prospective multicenter trial was conducted to compare the safety and efficacy of OKT3 as an induction therapy with that of conventional immunosuppressive therapy administered to cadaveric renal allograft recipients. Two hundred fifteen patients were treated either with OKT3 plus azathioprine and steroids for 14 days with the delayed addition of cyclosporine on day 11, or with conventional immunosuppression (steroids, azathioprine, and cyclosporine). OKT3 patients had significantly fewer rejection episodes (51% vs. 66%, P = 0.032), a longer time to initial rejection (46 days vs. 8 days, P = 0.001), and fewer rejection episodes per patient (0.82 vs. 1.14, P = 0.014) than conventionally treated patients. Kaplan-Meier estimates of two-year graft and patient survival rates were 84% and 95%, respectively, for the OKT3-treated group, and 75% and 94%, respectively, for the conventionally treated group. Following a subsequent first rejection episode, OKT3 reversed 93% of the rejections in patients receiving OKT3 induction therapy and 94% in patients receiving conventional therapy. Adverse experiences reported during OKT3 induction therapy were similar to those seen when the drug was used for rejection. Following initial exposure, 40.3% of the patients tested were positive for anti-OKT3 antibody, only 6.7% of which were of high titer (1:1000). In the presence of low titer (1:100 or less) antibody, OKT3 was successful in reversing rejection in five of six retreated patients tested. In conclusion, treatment with OKT3 (in combination with azathioprine, steroids, and the delayed addition of cyclosporine) is an effective approach for renal allograft maintenance.

Adolescent↗

PubMed1993

The need for second-generation antihepatitis C virus testing in uremic patients on continuous ambulatory peritoneal dialysis.

OBJECTIVE: To assess the prevalence and clinical relevance of a hepatitis C virus (HCV) infection in continuous ambulatory peritoneal dialysis (CAPD) patients by first- (Ortho) and second-generation (Abbott and UBI) HCV antibody enzyme immunoassays. DESIGN: Thirty-two serum samples tested by first-generation HCV antibody enzyme immunoassays (EIA's) were reevaluated using two second-generation HCV antibody EIA's. Basic demographic data, history of blood transfusions, and duration of hemodialysis and CAPD were reviewed. Results were analyzed by chi square analysis, Wilcoxon rank sum, and the paired t-test. SETTING: The medical college's affiliated teaching hospital. RESULTS: The prevalence of the antibody anti-HCV increases with the duration of previous hemodialysis, but not with the duration of CAPD. The positive detection of anti-HCV by second-generation HCV antibody EIA's was higher than first-generation EIA's (25% and 34.4% vs 12.5%). CONCLUSION: The prevalence and clinical relevance of HCV infection can be more accurately studied using the second-generation assays in uremic patients.

Adolescent↗

PubMed1992

Selective reversible and irreversible ligands for the kappa opioid receptor.

(+-)-(5 beta,7 alpha,8 beta)-3,4-Dichloro-N-methyl-N-[3-methylene-2- oxo-8-(1-pyrrolidinyl)-1-oxaspiro[4,5]dec-7-yl]benzeneacetamide (14) and its (5 alpha,7 alpha,8 beta) diastereomer 15 have been synthesized from 1,4-cyclohexanedione monoethylene ketal (1) in 10 steps. Compound 14, which we have designated SMBU-1, was found to bind with moderate affinity (Ki = 109 nM) and good selectivity (mu/kappa = 29) to the kappa opioid receptor, while 15 was only 1/10 as potent as a kappa ligand. Preincubation of brain membranes with 14 resulted in wash-resistant inhibition of kappa-receptor binding (69 +/- 6% of control at 10(-6) M). The ketone precursor trans-N-methyl-N-[5-oxo-2-(1- pyrrolidinyl)cyclohexyl]benzeneacetamide (12) showed a higher kappa-affinity (Ki = 78 nM) and a much higher kappa-selectivity (mu/kappa = 166) than 14. Compound 10, the ethylene ketal precursor of 12, exhibited a similar receptor binding profile to 14, with increased kappa-selectivity (mu/kappa = 55), while ketal 11, being a regioisomer of 10 and an oxygen isostere of the kappa-selective analgesic spiradoline (U-62,066), demonstrated the highest kappa-affinity (Ki = 1.5 nM) and kappa-selectivity (mu/kappa = 468) observed in this series.

Benzeneacetamides↗

PubMed1992

Three years' experience with levonorgestrel-releasing intrauterine device and Norplant-2 implants: a randomized comparative study.

A randomized comparative study of levonorgestrel-releasing intrauterine device (LNG-IUD) and Norplant-2 implants was carried out in 200 women for 36 months. Three thousand one hundred woman-months of use were observed with each device. Only one pregnancy occurred in users of LNG-IUD at the 12th month of use. The change in bleeding pattern was the most frequent reason for discontinuation. The discontinuation rate for irregular bleeding with Norplant-2 was 17.3 and 26.8 at 24 and 36 months, respectively, as compared to 3.3 with LNG-IUD at both 24 and 36 months. The differences were statistically significant. Removal for amenorrhea and pain only occurred in acceptors of LNG-IUD. About 20-40% of women using Norplant-2 had prolonged bleeding through 36 months. The percentage of amenorrhea in LNG-IUD was the highest (29.3%) at the end of two years of use. More than 97% of subjects reported satisfaction with the methods used by themselves.

Adult↗

PubMed1992

The structure of the Mental Health Inventory among Chinese in Taiwan.

This study attempted to ascertain the construct validity and external validity of the Mental Health Inventory in a Chinese population in Taiwan and contrast these results with results obtained from studies of several U.S. populations. In particular, a series of measurement models were specified and evaluated to address the issues of reliability and validity. Data were collected from personal interviews of a probability sample of 1,194 Chinese respondents 14 years of age and older in four townships in southwest Taiwan. The Mental Health Inventory was found to involve two major components: positive well-being and psychological distress. As a hierarchical structure, each component consists of one second-order and two or three first-order factors. The relationships between well-being and distress can be characterized as substantially independent and modestly bipolar depending on the level and specification.

Adolescent↗

PubMed1992

Differential Expression of Histone H3 Gene Variants during Cell Cycle and Somatic Embryogenesis in Alfalfa.

Northern analysis has revealed substantial differences in mRNA accumulation of the two histone H3 gene variants represented by pH3c-1 and pH3c-11 cDNA clones. Both in partially synchronized cell suspension cultures and in protoplast-derived cells from alfalfa, Medicago varia, the maximal level of the histone H3-1 gene transcript coincided with the peak in [(3)H]thymidine incorporation. Histone H3-11 mRNA was detectable in cells throughout the period of the cell cycle studied. Various stress factors such as medium replacement, enzyme digestion of the cell wall, osmotic shock, and auxin treatment considerably increased the level of the histone H3-11 transcript. In alfalfa (Medicago sativa), the presence of H3-11 mRNA in unorganized tissues of microcallus suspension and in somatic embryos induced by auxin treatment supports the idea that this H3 variant exists in a continously active state of transcription. During embryo development, the early globular stage embryos showed increased accumulation of histone H3-11 mRNA in comparison with the later stages. The highest level of the histone H3-1 transcript was detectable 1 day after treatment of callus tissues with 2,4-dichlorophenoxyacetic acid. Somatic embryos contained appreciable levels of histone H3-1 transcripts at all stages of somatic embryo development. These observations suggest that the histone H3-1 gene belòngs to the class of replication-dependent histone genes. The histone H3-11 gene showed characteristics of a constitutively expressed replacement-type histone gene, with a specific characteristic that external factors can influence the level of gene transcription.

Journal Article↗

PubMed1992

Efficacy of anticholinergic and beta-adrenergic agonist treatment of maximal cholinergic bronchospasm in tracheally intubated rabbits.

Cholinergically induced bronchoconstriction is thought to be a major cause of bronchospasm during anesthesia. We used tracheally intubated rabbits (4-mm endotracheal tube) stimulated with methacholine to assess the efficacy of beta-adrenergic agonist and anticholinergic treatment in reversing the increases in respiratory system resistance. Four groups were compared: (a) inhaled metaproterenol, 20 puffs via metered dose inhaler (0.65 mg/puff); (b) inhaled ipratropium bromide, 20 puffs from a metered dose inhaler (18 micrograms/puff); (c) 2 mg of intravenous atropine; and (d) no treatment after methacholine challenge as a control group. Methacholine increased respiratory system resistance from 0.041 +/- 0.001 (mean +/- SEM) to 0.098 +/- 0.006 cm H2O.mL-1.s-1 (P < 0.001). Whereas beta-adrenergic agonist treatment was ineffective in ameliorating bronchoconstriction, inhaled ipratropium bromide and atropine were highly effective, causing an 86%-88% reversal in the methacholine-induced increase in respiratory system resistance. Both these agents were also effective in improving dynamic compliance. We conclude that inhaled ipratropium bromide is effective in treating cholinergic bronchospasm even when administered via a small endotracheal tube and that the beta-adrenergic agonist metaproterenol is ineffective in rabbits in the face of maximal cholinergic stimulation.

Adrenergic beta-Agonists↗

PubMed1992

Expression of growth factor mRNA in rabbit PVR model systems.

Proliferative vitreoretinopathy (PVR) involves the formation of intravitreal fibrocellular membranes which may lead to traction retinal detachment and blindness. The cellular component of epiretinal membranes originates from the proliferation and migration of cells within the eye. Several growth factors and other cytokines are plausible candidates for directing the processes leading to membrane formation. A reproducible animal model is needed for experimental studies of cytokine expression during PVR induction or treatment. We found that intravitreal injection of > 10(6) mixed mononuclear leukocytes or adherent monocytes along with a trans-scleral incision through the pars plana leads to the development of PVR-like disease in rabbit eyes. The severity of the disease was related to the number of monocytes injected. Typically, organized membranes extending from the incision toward the optic nerve formed within one week. Progression to extensive traction retinal detachment required 1 to 4 weeks. Injection of up to 5 x 10(6) lymphocytes or freeze-thaw killed monocytes was ineffective, and coinjecting 100 micrograms endotoxin with the monocytes did not result in enhanced disease. The histological appearance of the epiretinal membranes was similar to human PVR membranes. Macrophage, cytokeratin-positive (epithelial), and fibroblast-like cells were present. Northern blot analysis of RNA extracted from the rabbit membranes revealed the presence of mRNA for acidic fibroblast growth factor (aFGF). Acidic FGF mRNA was not expressed by the injected monocytes. A comparable level of aFGF mRNA and also mRNAs for basic FGF, platelet-derived growth factor-B, and transforming growth factor beta were found in epiretinal membranes induced by a scleral incision in association with cryopexy.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1992

A simple animal model for inducing and releasing surgical jaundice in rats.

Surgical jaundice can be easily induced by ligation of bile duct, but it is not easy to reverse the ligation in rats. Therefore, a simple method was designed in our laboratory to address the problem. Obstruction of bile duct can be achieved by the compression by two arms of a fine silicon tube enveloped in an outer bigger silicon tube. Both silicon tubes are then fixed and sutured to the abdominal peritoneum. Therefore, if the releasing of the obstruction is required, removal of the inner fine silicon tube by removing off the previous suture tire of silicon tube which had settled under the skin. Thus, the reversing of obstruction could be achieved without extensive exploration into the abdominal cavity. One week after obstruction the bile duct of rats were dialated 6.10 +/- 1.26 mm (Mean +/- SD) in rats. The serum bilirubin and alkaline phosphatase were 6.29 +/- 1.26 mg% and 229.30 +/- 82.22 IU respectively. The dilated bile duct decreased into 3.00 +/- 0.98 mm one week after decompress with this method. Serum bilirubin and alkaline phosphatase were 1.80 +/- 0.79 mg% and 90.50 +/- 19.60 IU respectively. It proved that this animal model was simple and had the benefit of being able to sample the bile without contamination with intestinal contents after decompression.

Alkaline Phosphatase↗