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Biomedical subjects

S C Yang

Publications and source records attributed to S C Yang.

At least 91 records · Page 5Linked to original sources
PubMed1994

[Effects of air pollutants on pulmonary function and bronchial reactivity in patients with chronic obstructive pulmonary disease].

Exposure to polluted air can cause respiratory symptoms in subjects with airflow limitation. Twelve COPD (chronic obstructive pulmonary disease) patients with mild to moderate obstructive ventilatory defects were exposed on separate occasions to fresh ambient air and polluted air collected from the Lin-Sun S. Road tunnel in Taipei City. Concentrations of SO2 and NO2 were 85-121 ppb and 449-502 ppb, respectively, and were 4-fold and 10-fold, respectively, higher than those of out-door air in the city. Twenty healthy adult volunteers served as the control group. Maximal expiratory flow-volume determination, respiratory resistance (Rrs) and methacholine bronchial challenges were completed before and after inhalation of polluted air for 20 minutes. No difference in FVC (forced vital capacity), FEV1 (1 second forced expiratory volume), Rrs and bronchial reactivity was noted for normal subjects after inhaling polluted air and ambient air. For patients with COPD, there was a small but significant decrease in FEV1 after exposure. The elevation in Rrs was prominent, and there was also a significant increase in bronchial sensitivity to methacholine (decrease in cumulative provocation dose, DA) in positive responders. We conclude that short-term exposures to moderate polluted air can affect lung function and increase bronchial sensitivity to methacholine in COPD patients.

Aged↗
PubMed1993

Etiological investigation of acute post-transfusion non-A, non-B hepatitis in China.

The etiology of acute post-transfusion hepatitis (PTH) non-A, non-B (NANB) in China was investigated with the combination of advanced techniques, including a second generation of enzyme immunoassay for detection of the antibodies to hepatitis C virus (anti-HCV), a reverse transcription and nested polymerase chain reaction (RT-nPCR) for HCV RNA, and a PCR for hepatitis B virus DNA. Of the 57 patients who were diagnosed as acute PTH-NANB, 46 (80.7%) were positive for anti-HCV and 41 (71.9%) had HCV RNA. Combining together, 53 (93.0%) were seropositive for anti-HCV and/or HCV RNA. Surprisingly, 18 of these with HCV markers were also positive for HBV DNA, although they were negative for HBsAg, suggesting that a portion of the patients with acute PTH NANB were coinfected by both HCV and HBV. In addition, 4 (7%) of the patients with acute PTH-NANB had no detectable HCV and HBV markers with the use of the above-mentioned techniques. These results indicate that etiologic agents(s) other than HCV and HBV may also cause acute PTH-NANB or that the current techniques may still not be sensitive enough to detect trace levels of HCV and HBV markers.

Adolescent↗
PubMed1993

Prediction equations for single-breath carbon monoxide diffusing capacity from a Chinese population.

Most available prediction equations for the single breath carbon monoxide diffusing capacity, or DLCO, are based on white populations and do not account for racial differences. We performed this test on 436 Chinese adults. The method of measurement essentially followed the American Thoracic Society recommendations. Data on 306 subjects who had two technically acceptable test results provided prediction equations and upper and lower 95% confidence limits for healthy nonsmokers. Simple linear equations using age, height, and body weight as independent variables were generated and compared with nonlinear models. The use of nonlinear models did not add to the predictability of standard linear regressions. The distribution of residuals (predicted-measured values) was Gaussian with simple linear regressions. A comparison of predicted values for DLCO, calculated from different equations in an independent group of healthy subjects, revealed that the present set of equations had the smallest residual mean and standard deviation rankings compared with other equations for white subjects. These are the first DLCO equations proposed for Chinese men and women aged 20 to 70 yr. The predicted values from this study for DLCO and alveolar volume (VA), were significantly lower than those of most equations for white subjects, but were not for DLCO/VA. Although a portion of the differences may be explained by the additive effects of technical factors, the discrepancies can also be attributed to the smaller body size in this ethnic group, and consequently to the smaller lung volumes. Equations derived from whites, with inclusion of smokers, provided predicted values comparable to, or even lower than, those from this study.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Effects of amino acids on alcohol intake in stroke-prone spontaneously hypertensive rats.

Examination was made of the effects of amino acids on alcohol intake in stroke-prone spontaneously hypertensive rats (SHRSP). The animals were divided into two groups according to dietary protein level, normal (15%) and low (5%). The two groups were further divided into two groups according to whether they selected the ethanol solution containing amino acids (non-amino acid group and amino acid group). The 5% ethanol solutions with and without various amino acids were prepared in a water-supplying tube to which the animals had free access for 40 days. The 5% ethanol solution intake in rats fed the normal protein diet was higher than that of the low protein group. Regardless of dietary protein level, 5% ethanol solution intake increased in the amino acid group. Intake of the 5% ethanol solution containing 100 mM L-proline, 100 mM L-lysine, and 100 mM L-threonine was large. For the amino acid group of rats fed normal protein and low protein, plasma glutamate oxalacetate transaminase (GOT) activity was significantly reduced. It is suggested that the alcohol intake may increase by adding amino acid to the alcohol solution.

Alcohol Drinking↗
PubMed1993

Living donor nephrectomies-right side--intraoperative assessment of the right renal vascular pedicle in 112 cases.

Generally, the left kidney from a living donor is more commonly preferred but the right kidney is occasionally donated because of multiple left renal arteries or repeated transplantation. The right donor nephrectomy is usually more difficult compared to the left because the right renal vein is often multiple and short, which complicates dissection of the vascular pedicle. From Jan. 1989 to Sep. 1992, 112 consecutive cases of right donor nephrectomies out of a total of 771 cases were retrospectively reviewed with the preoperative renal angiography and the intraoperative assessment of the right renal vascular pedicle. The indications for right donor nephrectomy include 1) multiple or proximal bifurcating renal arteries of the left kidney (89.3%), 2) repeated transplantation in the recipient (9%). In 26.8% of the cases, there were more than two right renal veins. In the right donor nephrectomy, it is often necessary to perform vena cava cuff resection because of short and frequently occurring multiple right renal veins. For the dissection of the inferior vena cava (IVC), the aberrantly occurring right gonadal vein, the adrenal vein draining above the junction of the renal vein and IVC, and the lumbar vein below the junction should always be looked for and must be ligated if any are found.

Adult↗
PubMed1993

[Pulmonary diffusing capacity in normal smoking Chinese].

Single-breath carbon monoxide diffusing capacity parameters including DLCO, VA and DLCO/VA were studied in 131 asymptomatic healthy smoking Chinese men aged 25-70 years. Measurements were conducted with a rolling-sealed, computer-based pulmonary function analyzer and were in accordance with testing procedures recommended by the American Thoracic Society. Diffusing capacity in smokers was compared with that in normal nonsmoking adults. Cigarette smoking caused a reduction in DLCO and DLCO/VA, but not in VA. Therefore, the change in diffusing capacity was not related to a decrease in lung volume. Twenty-one percent of all smoking subjects showed an abnormally low DLCO value. The onset of this defect in pulmonary diffusion appears to occur early in cigarette smokers. Since older smokers with evidence suggestive of pulmonary emphysema or chronic bronchitis were excluded due to their respiratory symptoms, the accumulated effect of smoking on DLCO cannot be demonstrated in this study. The prediction equations of DLCO, VA and DLCO/VA were generated for Chinese male smokers, using age, height and weight as the independent variables. The present study was unable to include any tobacco smoking parameters in the regressing equations. It is postulated that the modest increase in carboxyhemoglobin (COHb %) in smokers may explain the immediately lower DLCO values observed in smokers shortly after they begin smoking.

Adult↗
PubMed1993

[Re-evaluation of the ventilatory function in a normal Chinese: comparison with the results of a survey conducted 15 years ago].

Maximal expiratory flow-volume and volume-time curves were studied with a rolling-sealed, computer-based pulmonary function analyzer in 354 nonsmoking healthy Chinese (210 men and 144 women) aged 18-78 years. The testing procedures were in accordance with those recommended by the American Thoracic Society. Both volume and flow rate parameters had a negative correlation with age and had a positive correlation with height in both sexes except for FEV1/FVC. The coefficients of variation (CV) for FVC, FEV1 and FEV1/FVC were much smaller than those for PEFR, Vmax75, Vmax50 and Vmax25, with FEV1/FVC having the lowest CV. Prediction equations of FVC, FEV1, FVC/FEV1, PEFR, FEF25-75%, Vmax75, Vmax50 and Vmax25 were generated for Chinese aged 20-80 years, using age, height and body weight as independent variables, to define normal reference values. A comparison of the predicted values for FVC and FEV1, with those calculated from the equations developed in this laboratory 15 years ago, reveal that the present set of equations have higher values for the younger age group for FVC and FEV1 but lower values for the elderly of both sexes, except for FVC in men. The predicted values for Vmax50 and Vmax25 in the present study were also lower than those of the previous survey. Better nutritional status, improved respiratory muscle strength, increased body size in women and a prolonged life-expectancy, which made the inclusion of more elderly subjects possible, were attributed to explain the differences observed between these two studies.

Adolescent↗
PubMed1993

[Relationship between smoking habits and lung function changes with conventional spirometry].

Maximal expiratory flow and volume parameters derived from simultaneous maximal expiratory flow-volume and volume-time curves obtained by the forced vital capacity maneuver were studied in 311 healthy normal Chinese men, consisting of 180 nonsmokers and 131 smokers of 20 to 78 years of age. Six maximal expiratory parameters--FVC, FEV1, FEV1/FVC, PEFR, FEF25-75% and Vmax75, both unadjusted and adjusted for age and body height, were compared between nonsmokers and smokers to study the effects of smoking on ventilatory function and to detect early abnormal changes. In current smokers and ex-smokers, the FEV1/FVC was significantly lower than that of nonsmokers. However, no such differences were noted for FVC and FEV1. Among FVC, FEV1 and FEV1/FVC, a low FEV1/FVC appeared to be the earliest discriminative index in normal asymptomatic smokers. With increasing quantity and duration of smoking, a higher incidence of abnormally low FEV1 and FVC compared to those who smoked a lesser amount or for a shorter period of time, were observed in sequence. Current smokers over the first 5 pack-yrs of smoking did not show any abnormality in FVC, FEV1 and FEV1/FVC. It is concluded that cigarette smoking is associated with a decrease in pulmonary function although the effects take some time to develop and are not immediately apparent after beginning the smoking habit. There is an irreversible decrease in FEV1/FVC with cumulative cigarette consumption, but smoking cessation will prevent further deterioration in FEV1 and FVC.

Adult↗
PubMed1993

[Effects of ipratropium bromide as a nebulized solution on respiratory function in mechanically ventilated patients].

Ipratropium bromide is an atropine-like bronchodilator with a mechanism of action via the anticholinergic pathway, and which may decrease cyclic guanosine monophosphate. Twenty ventilated patients (14-85 years old) with acute airflow obstruction and wheezing or coughing participated in a double-blind trial of nebulized bronchodilator treatment. Maintenance theophylline with or without a steroid preparation was continued and comparison was made between ipratropium bromide and a placebo. The study was randomized and conducted on two separate days commencing at the same time each morning. It was found that both the inspiratory resistance and the respiratory symptom scores decreased after ipratropium inhalation. The arterial O2 and CO2 tension did not change. Cardiovascular side effects appeared to be minimal. Since lung compliance was not affected by aerosol administration of ipratropium, it is possible that this drug acts only on the large airways. No significant alteration in the mean airway pressure was observed. We conclude that ventilated patients with bronchospasms can benefit from nebulized ipratropium alone. Their responses, assessed in terms of inspiratory resistance and symptom relief, may be explained by the bronchodilatation and better airflow resulting from the inhaled ipratropium.

Administration, Inhalation↗
PubMed1993

The possible involvement of tissue type plasminogen activator in luteolysis of rhesus monkey.

Changes of plasminogen activators (PA) during different stages of development of the corpus luteum, and their possible physiological role in luteolysis were studied in rhesus monkeys. It was demonstrated for the first time that monkey corpus luteal cells not only produce PA, but that the function of the corpus luteum is also closely related to the activity of this enzyme system. Generally, the life span for a corpus luteum in monkey is approximately 14-16 days, its demise beginning thereafter. In the present study, we found that urokinase in the corpus luteum is higher on day 5 and day 10 after human chorionic gonadotrophin injection, while the tissue type (t) PA is mainly produced on day 13 when luteolysis may take place. Progesterone production remained high on day 5 and day 10 and decreased dramatically from day 13, indicating the important role of tPA but not urokinase (u) PA in suppressing luteal function. When purified tPA (but not uPA) monoclonal antibody was added to luteal cell culture to neutralize endogenously produced tPA activity, progesterone production in the cells was increased significantly. Interestingly, prolactin alone was capable of increasing PA production by luteal cells; prolactin together with luteinizing hormone, however, had a synergistic luteotrophic effect.

Animals↗
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↗