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Biomedical subjects

S C Yang

Publications and source records attributed to S C Yang.

13 recordsLinked to original sources
PubMed1992

Endobronchial tuberculosis. Clinical and bronchoscopic features in 121 cases.

The clinical and bronchoscopic features of endobronchial tuberculosis in 121 patients were retrospectively investigated. The peak incidence occurred in the second decades, with 3.8 times higher incidence noted in female than in male subjects. A barking cough with sputum was the most common chief complaint in 61.1 percent. Parenchymal infiltration and/or consolidation was the most common roentgenographic finding of the chest in 58.6 percent. Hypertrophy with luminal narrowing was the most common bronchoscopic finding in 43 percent. Bronchoscopically, right upper and right main bronchus were the most frequently involved in 30.5 percent. It was concluded from these data that using fiberoptic bronchoscopy allows not only substantial meaningful assessment of endobronchial tuberculosis but also relieves atelectasis eventually resulting in successful treatment with antituberculosis drugs.

Bronchi↗
PubMed1992

Biliary proteins in patients with and without gallstones.

BACKGROUND: Nucleation from supersaturated bile of calcium salts of cholesterol and bilirubinate is essential in the formation of gallstone. Nucleation requires gallbladder mucin and its main component, glycoprotein, may contribute to gallstone formation by providing a nidus or matrix for precipitation of lipid components. However, biliary protein patterns of patients with gallstones have not been completely explored. METHODS: We have tried to extract, isolate and characterize the proteins in patients with gallstones and without gallstones. 21 bile samples were obtained from patients with different types of gallstones and with no stones at cholecystectomy. Biliary protein concentrations were measured by Lowry and Bensadoun methods, and individual glycoproteins from each of the patients were compared by silver staining and densimetric quantification of Sodium Dodesyl Sulfate Polyacrylamide Gel Electrophoresis. RESULTS: 1) Among 16 gallstones, 5 were cholesterol stones, 5 were calcium bilirubinate stones, and 6 were black pigment stones. 2) The mean protein concentration was highest in bile with cholesterol stones (47.6 mg/ml), 24.2 mg% in bile without gallstones, and 15.9 mg/ml in brown pigment stones. 3) Cholesterol gallstones were found to have 14.2 KD glycoproteins, whereas pigment stones were found to have 66 KD glycoproteins. CONCLUSIONS: Gallbladder proteins from both cholesterol and pigment stones play an important role in the nucleation and growth of calcium salt crystals.

Bile↗
PubMed1992

Combination immunotherapy for advanced lung cancer.

Therapeutic strategies using cytokines have not been extensively tested in patients with advanced non-small-cell lung cancer (NSCLC). We developed a basic laboratory and clinical research program to investigate the effective immunotherapeutic manipulations for activating the endogenous immune system with biological agents. Our efforts using low-dose interleukin 2 in conjunction with other biologic response modifiers for the treatment of NSCLC are summarized here.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

Single-breath carbon monoxide diffusing capacity: effect of body size and age in healthy nonsmoking Chinese.

Because of unanswered questions about reference values for single-breath carbon monoxide diffusing capacity (DLCO) in Chinese, standardized DLCO measurements were carried out in a selected sample of 257 healthy nonsmoking Chinese aged 20-70 years. The methods of measurement essentially followed the American Thoracic Society (ATS) recommendations. The measured DLCO was corrected to a standard hemoglobin value. Observed mean values for DLCO were 25.87 +/- 5.64 mL/min/mmHg in men and 21.16 +/- 3.88 mL/min/mmHg in women. Correlations of DLCO indices with anthropometric variables revealed that DLCO was best correlated with age in both sexes (r = -0.71 for men and r = -0.61 for women, p < 0.001). For alveolar volume (VA), the most significant correlation was found with height. For specific diffusing capacity (DLCO/VA), there was a significant negative relationship with age. Reference equations using age and body surface area (BSA) as independent variables for DLCO, VA and DLCO/VA were derived separately for men and women. An analysis of the distribution of residuals was Gaussian with simple linear regressions. Predicted values for DLCO and VA, as estimated in the present study, were much lower than equations derived from Caucasian populations. On the contrary, DLCO/VA values, as predicted by the present set of equations, were comparable to those of Caucasian equations. Therefore, differences in DLCO values between Chinese and Caucasians may be explained by differences in lung volume rather than by ethnic variations in the inherent characteristics of the alveolar capillary membrane. Predicted values for Chinese should be obtained from equations established from this study rather than extrapolated from those of Caucasians. The results of this study will be of value to clinical laboratories dealing with pulmonary function testing for Chinese patients.

Adult↗
PubMed1991

Clinical and immunomodulatory effects of combination immunotherapy with low-dose interleukin 2 and tumor necrosis factor alpha in patients with advanced non-small cell lung cancer: a phase I trial.

Sixteen patients with metastatic non-small cell lung cancer were treated with a combination of simultaneous low-dose interleukin 2 (IL-2) and tumor necrosis factor alpha. The purpose of this phase I dose escalation trial was to assess the clinical toxicities, immunomodulatory effects, and antitumor efficacy of this combination. Patients received a continuous daily i.v. infusion of 6 x 10(6) IU/m2 of IL-2 for 5 days and a concomitant daily i.m. dose of tumor necrosis factor alpha on each day of IL-2 administration. Tumor necrosis factor alpha administration started at a dose of 25 micrograms/m2/day (level I) for seven patients, 50 micrograms/m2/day (level II) for seven patients, and 100 micrograms/m2/day (level III) for two patients. Treatment was given at 3-week intervals. Only one patient required monitoring by an intensive care unit during therapy. Major toxic effects included fever, local skin reaction at the i.m. injection site, pancytopenia, and general malaise, all of which were reversible within 48 h of cessation of therapy. Dose level II was determined to be the maximum tolerated dose, with the dose-limiting toxicity being thrombocytopenia (less than 50,000/microliters). In 12 evaluable patients, one partial and three minor tumor regressions were observed. Seven patients with progressive disease before entry into this study had radiographic stabilization of their disease (median, 12 weeks) before termination of therapy due to progression. All patients exhibited biological responses including augmented lymphokine-activated killer and natural killer cell activities while receiving therapy, as assessed by the cytolysis of Raji- and K562 targets in vitro. Enhanced lysis of autologous tumor during therapy was demonstrated for four patients with available tumor samples. Serum levels of IL-2 were detected by enzyme-linked immunosorbent assay 2 weeks after cessation of therapy. This serum IL-2 had biological activity, which was evident from the ability to induce proliferation of NK-8 cells (an IL-2-dependent cell line) which was abrogated by anti-IL-2 antibody.

Adolescent↗
PubMed1991

Phenotype and cytolytic activity of mouse tumor-bearer splenocytes and tumor-infiltrating lymphocytes from K-1735 melanoma metastases following anti-CD3, interleukin-2, and tumor necrosis factor-alpha combination immunotherapy.

We studied the phenotype and antitumor cytolytic activity of splenocytes from mice with K-1735 pulmonary metastases and tumor-infiltrating lymphocytes (TILs) from these metastases following treatment with anti-CD3, IL-2, and TNF combination immunotherapy. Mice were injected with 5 x 10(4) tumor cells and received a single 5 micrograms i.p. dose of anti-CD3 on day 3, followed by either IL-2 alone or fourfold less IL-2 with TNF (25,000 U/day) given at 3-day intervals. A single dose of anti-CD3 followed by low-dose IL-2 and TNF caused the greatest reduction in metastases compared to anti-CD3 alone, higher doses of IL-2 alone, or IL-2 + TNF. Reduction in metastases (greater than 80%) using the three agents was equal to or exceeded that achieved by ninefold higher concentrations of IL-2 alone. Treatment with anti-CD3 + IL-2 and TNF significantly prolonged survival, and resulted in 60% of mice achieving long-term survival greater than 120 days. This was superior to single agents or other combinations with the three agents causing a synergistic rather than additive effect. The anti-CD3-activated splenocytes were a heterogeneous population of T cells, with an increased number of CD8+ cells compared to splenocytes from mice treated with high doses of IL-2 alone. Analysis of TILs showed a greater proportion of CD8+ cells in anti-CD3-treated mice compared to IL-2 alone, but a lower proportion of CD4+ cells. Lymphokine-activated killer (LAK) and natural killer (NK) activities of both splenocytes and TILs in vitro increased following anti-CD3/IL-2 + TNF treatment, and were consistently greater than that generated with four times more IL-2 alone. TNF appeared to potentiate cytolytic activity rather than affect phenotypic changes. These results indicate that the sequential use of anti-CD3, IL-2, and TNF for LAK induction and maintenance potentiates antitumor activity, and suggests novel strategies for combination immunotherapy.

Animals↗
PubMed1991

Lung volume, diffusing capacity, chest roentgenogram and dyspnea index in interstitial lung disease.

To investigate the physiologic impairment and the role played by pulmonary function tests in interstitial lung disease (ILD), we performed spirometry tests and tested the single-breath carbon monoxide diffusing capacity of 27 patients with diffuse interstitial pulmonary fibrosis (DIPF) and 35 patients with collagen vascular disease (CVD). All of the patients showed irregular linear opacities on their chest X-ray films. Corresponding chest roentgenograms for each patient were evaluated according to the International Labour Organization (ILO) classification. A modified Baseline Dyspnea Index (BDI), which incorporate a patient's physical activity into the recording, was used to quantitate dyspnea. Patients with DIPF demonstrated a comparable reduction in both lung volumes and diffusing capacity. In contrast, patients with CVD had a greater reduction in diffusing capacity than in forced vital capacity (FVC) and total lung capacity (TLC). There were no significant correlations between the type of linear opacities and the severity of the pulmonary function abnormalities, or between the opacities and the dyspnea in either disease group. The profusion of pulmonary infiltrates also did not affect the lung function except for diffusing capacity in patients with DIPF. However, there was a significant loss of FVC, TLC, forced expiratory volume in one second (FEV1) and diffusing capacity with increasing levels of dyspnea. We conclude that pulmonary function parameters may not be equally affected in DIPF and CVD. Approaches using the ILO classification for analysis of chest roentgenograms provide limited information regarding the functional status of patients. Pulmonary functions are significantly related to the extent of a patient's physical activity, if the severity of dyspnea is evaluated carefully using a quantifiable system.

Adult↗
PubMed1991

Effects of sodium valproate and 4en-valproic acid on isolated hepatocytes of guinea pigs.

The effects of valproic acid (VPA) (100 to 2,000 micrograms/ml) and its metabolite 4en-valproic acid (4enVPA) (2 to 2,000 micrograms/ml) on plasma membrane permeability of isolated hepatocytes of guinea pigs were studied. The ability of hepatocytes to exclude trypan blue was decreased significantly (p less than 0.05) by VPA at concentrations higher than 100 micrograms/ml. The leakage of intracellular enzymes, lactate dehydrogenase (LDH), glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT) and gamma-glutamyl transpeptidase (GGT), were not significantly increased by VPA within therapeutic concentrations (100-200 micrograms/ml). However, GOT and GPT leakage were significantly increased (p less than 0.05) by VPA, 500 micrograms/ml, but tended to decrease with further increases in VPA concentration. The enzyme leakage or trypan blue exclusion was not significantly altered by 10 micrograms/ml 4enVPA unless phenytoin (PT) (20 micrograms/ml) or phenobarbital (PB) (20 micrograms/ml) was presented. Higher concentrations of 4enVPA significantly decreased the trypan blue exclusion as well as increased GOT and GPT leakage of hepatocytes. Under scanning electron microscopic examination some hepatocytes at therapeutic concentrations of VPA or 4enVPA showed blebs on the membrane. Higher drug concentrations caused serious membrane damage such as pits and pores. These results suggest that there may be at least two mechanisms for the hepatotoxic effect of VPA. One may occur at therapeutic concentrations of VPA, resulting in increases in membrane permeability and decreases in membrane tension of hepatocytes. The other mechanism may occur at high concentrations of VPA or 4enVPA, resulting in substantial damage to the hepatocyte membrane.

Animals↗
PubMed1976

Reovirus antibodies among animals in Taiwan.

Serum specimens for reovirus antibody survey were collected from 60 pigs, 50 buffalos, 30 rabbits, 30 guinea pigs, 20 albino rats, 60 Swiss mice, 15 Taiwan monkeys, 14 goats and 12 dogs. Serum antibodies were measured by the hemagglutination inhibition (HI) test. HI antibodies to reovirus were found in a high percentage of pigs, albino rats, Swiss mice, dogs and goats, and less frequently in rabbits, guinea pigs, Taiwan monkeys and buffalos.

Animals↗