Biomedical subjects

C D Chiang

Publications and source records attributed to C D Chiang.

At least 19 recordsLinked to original sources

PubMed1992

Impalpable thoracic bony lesions diagnosed by sonographically guided needle aspiration biopsy.

Impalpable osteolytic lesions may be detected and diagnosed by ultrasonography and sonographically guided needle aspiration biopsy. Eleven cases with bone destruction found on chest radiographs were proved to be malignant by sonographically guided needle aspiration biopsy. The bony lesions were all hypoechoic and could be demonstrated easily. No complications or discomfort occurred after needle aspiration. Bony lesions can be detected by ultrasonography only when pathologic changes have occurred. Ultrasonography and sonographically guided needle aspiration biopsy provide a simple, convenient, and non-invasive method for detecting and diagnosing impalpable osteolytic lesions.

Aged↗

PubMed1992

The predictability of matched ventilation perfusion scan in pulmonary embolism.

In retrospect, we reviewed 17 cases of proven pulmonary emboli at Taichung VGH. These patients were then divided into two groups, the matched and the mismatched V/Q scan. Patients with lung consolidation, along with their chest films, were studied and characterized. In the matched V/Q group (5 cases), perfusion defects were comparable with lung consolidation in both size and location. In the V/Q mismatched group, perfusion defects were larger than lung consolidation (either single or multiple foci). A matched V/Q scan in patients with a pulmonary embolism, may result from lung consolidation induced by a pulmonary infarction, localized edema, or hemorrhage. A matched V/Q scan with localized lung consolidation in a suspicious case could not rule out pulmonary embolism, and further evaluation is mandatory.

Aged↗

PubMed1992

Cytotoxicity studies on some novel 2,6-dimethoxyhydroquinone derivatives.

Six synthetic 2,6-dimethoxyhydroquinone derivatives were shown to have different degrees of cytotoxicity to two human tumor cell lines (KB and PC-9) under the synergistic activation of L-ascorbic acid. Two representative compounds displayed very low time-schedule-independent index, showing that the cytotoxic action is independent of time of drug treatment. The addition of catalase produced a significant inhibitory effect on the cytotoxicity of two representative compounds, indicating that the cytotoxic action is mediated by the generation of H2O2, which may yield hydroxyl radicals via various mechanisms. ESR studies employing the spin-trap 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) showed that massive hydroxyl radicals were generated from four of these drugs as a non-linear function of L-ascorbic acid concentration. The results indicate the possible involvement of hydroxyl radicals in the cytotoxic action of these novel drugs.

Adenocarcinoma↗

PubMed1992

Serodiagnosis of tuberculosis by an enzyme-linked immunosorbent assay using mycobacterial antigen 60.

This study was undertaken to assess the diagnostic utility of an enzyme-linked immunosorbent assay using mycobacterial antigen 60 in patients with pulmonary tuberculosis. This test was applied to 210 adults, including 111 patients with active pulmonary tuberculosis, 80 control subjects and 19 patients with inactive pulmonary tuberculosis. Although the serums from the patients with active tuberculosis has a higher mean value of IgG antibody concentration than the control group, there was a considerable overlap of serum IgG antibody level between the two groups. 200 ELISA unit (EU) was established as a reasonable cut-off value, which gave an 80.2% (89/111) sensitivity for the group with active pulmonary tuberculosis and a specificity of 76.3% (61/80) only for the control group. The patients with inactive pulmonary tuberculosis had a positive rate up to 47.4% (9/19) when 200 EU was chosen as a cut-off value.

Adult↗

PubMed1992

An evaluation of long-term nasal CPAP therapy for sleep apnea.

Nasal continuous positive airway pressure (CPAP) is an effective therapy for sleep apnea. Little is known about long-term patient compliance and side effects with this therapeutic modality in the Chinese. In order to evaluate this, we collected 8 obstructive sleep apnea patients who received home nasal CPAP therapy between January 1990 and July 1991. Each received two sets of nap polysomnographic studies. The initial set was performed to diagnose and evaluate patient response to CPAP as well as defining the CPAP pressure the patient would be using at home. The second set of studies were conducted for follow up and re-evaluation. Seven of these patients reported using nasal CPAP during sleep at night, and one did not use it all. Nasal CPAP improved clinical symptoms, particularly daytime sleepiness, and 7 patients were generally satisfied with nasal CPAP. Initially the side effects were a dry throat and nose. After 5 to 15 months of CPAP treatment, the follow-up nap sleep studies showed no significant change in the apnea/hypopnea index, duration of apnea, or oxygen desaturation between the diagnostic and follow-up (without CPAP) studies. However the amount of nasal CPAP pressure setting declined in 4 of 7 patients. Our own experience indicates that long-term nasal CPAP is an important new means of treatment for sleep apnea and allows a normal daytime life. It was well-tolerated by most sleep apnea patients. However, it is necessary to further evaluate of morbidity and the amount of pressure setting relative to long-term home nasal CPAP.

Adult↗

PubMed1992

[Blood lactate changes during incremental exercise in chronic obstructive pulmonary disease].

In order to evaluate whether the lactic acidosis is developed during incremental exercise test in COPD. 12 untrained subjects with COPD performed incremental maximal cycle ergometer tests. Ventilation (VE); O2 uptake (VO2), CO2 output (VCO2); and end-tidal CO2 fraction (FETCO2) were measured. Arterial lactate concentration and blood gas analysis were measured at rest, maximal exercise and recovery of exercise from an indwelling arterial catheter. of the degree of airway obstruction. (2) T40 and BEecf correlated well with lactate change (r = 0.83; 0.84, P < 0.05). (3) The change of VE, and RQ correlated with the lactate change (r = 0.81; 0.83, 0.72, P < 0.05), but not the VE/VO2, VE/VCO2, nor FETCO2, (r = 0.24; 0.06; 0.46, P > 0.05). We concluded that the blood lactate increased markedly in patients of COPD during increment exercise, and it was well corrected with the change of VE, VCO2 and RQ. The increased lactate could be indicated by the concomitant change of T40 and BEecf.

Aged↗

PubMed1992

Detection of mass lesions in the collapsed lung by ultrasonography.

Ultrasonography is useful in the detection of mass lesions in the collapsed lung, using the collapsed lungs as a "sonic window". Twenty-four patients suspected of having a tumor causing lung collapse, as shown on their chest radiographs, were examined by ultrasonography. Eighteen out of 24 patients were found to have mass lesions in their collapsed lungs. Thoracic computed tomography (CT) was also performed in 12 of these 18 patients; of those, 11 showed compatibility with sonographic findings in the detection of mass lesions in their collapsed lungs. The remaining six of these 24 patients with no mass lesions detected by ultrasonography were proven to have collapsed lung due to sputum impaction (n = 2) and lung cancer (n = 4). The fact that four patients had lung cancer that was not detectable by ultrasonography, might have been due to relatively small mass lesions at deep locations (main or intermediate bronchus) and narrowing of the "sonic window" (partial lung collapse). Though it has some limitations, ultrasonography is helpful in detecting mass lesions in collapsed lungs. Sono-guided fine needle aspiration biopsy (SGFNAB) can also be performed simultaneously, smoothly and without any major complications. In our series, SGFNAB was performed in eight out of 18 patients to make a cytopathologic diagnosis. We recommend this safe, convenient, and noninvasive method to screen for lesions in the collapsed lung, especially when bronchoscopic examination is impossible.

Aged↗

PubMed1992

[Intraoperative pleural lavage in lung cancer patients].

In lung cancer patients, pleural effusion may or may not be present even if cancer cells have invaded the pleura. Using the traditional staging methods, not all pleural metastasis can be detected before the presence of pleural effusion. We performed intraoperative pleural lavage on 38 patients who underwent a thoracotomy due to tumors of the lungs. The first lavage (lavage 1) was performed just after the pleural cavity was open; the second lavage (lavage 2) was performed after all surgical procedures were completed (including lung resection and mediastinal lymph node dissection). Totally 12 of the 32 primary lung cancer patients were found to have positive lavage 1 cytology; 13 had positive lavage 2 cytology. In 13 patients whose visceral pleura was invaded by tumor, 11 had a positive lavage 1, 10 had a positive lavage 2. For prediction of positive lavage 1 cytology from visceral pleural involvement, the accuracy was 90.6%, the sensitivity was 84.6%, the specificity was 94.7%, the positive predictive rate was 91.7%, the negative predictive rate was 90.0%. For lavage 2, the accuracy was 81.2%, the sensitivity was 76.9%, the specificity was 84.2%, the positive predictive rate was 76.9%, the negative predictive rate was 84.2%. Stage of disease and cell type seemed to have no relationship to the incidence of positive lavage fluid cytology. Further investigation is recommended to evaluate the prognosis of patients with positive lavage fluid cytology.

Humans↗

PubMed1992

Diffuse panbronchiolitis: report of a case.

A 33-year-old male presented with a productive cough of yellowish sputum which he had had for several years and progressive dyspnea on exertion that had been present for one year. Physical examination on admission disclosed clubbing of the fingers, diffuse inspiratory crackles and some rhonchi on auscultation. Plain chest film showed diffuse fine nodular lesions in both lungs. Pulmonary function tests demonstrated obstructive ventilatory impairment with a positive bronchodilator response. A CT scan of the chest showed diffuse fine nodular infiltrations in both lung fields. Arterial blood gas analysis of the patient, while breathing room air, revealed mild hypoxemia. The histologic findings of an open lung biopsy specimen were compatible with a diagnosis of diffuse panbronchiolitis. The patient was treated with erythromycin and a bronchodilator, and was regularly followed at the outpatient department. In this report, clinical manifestations, diagnostic criteria and recent advances in the treatment of diffuse panbronchiolitis are discussed.

Adult↗

PubMed1991

A new device of incentive spirometry.

Incentive spirometry is a feedback system to encourage patients to take a deep breath and produce a sustained maximal inspiration (SMI) for the primary purpose of opening and stabilizing atelectatic areas of the lung. However, currently available incentive devices are not reusable, expensive, and emphasize inspiratory effort only. We have designed a new device of incentive spirometer based on pursed-lip breathing technique. The device consists of a piece of paper hanging on a frame. The patient is instructed to take a deep and slow inspiration followed by holding the breath for 5 seconds. Then, using pursed-lip technique, the patient generates a flow to keep the paper attached to a bar as long as possible. The duration of paper blowing is recorded and is compared with vital capacity. In the present study 96 cases were recorded. Vital capacity was correlated well with paper blowing time (multiple regression test r = 0.87, p less than 0.0001). The advantages of our device include (1) reusibility and less cost, (2) equal emphasis of both inspiration and expiration, and (3) being especially helpful for patients with chronic obstructive lung disease (COPD). This is a preliminary result and further clinical study is needed.

Breathing Exercises↗

PubMed1991

Combined atelectasis of right upper and middle lobes: a clinical study of 15 cases.

Because of the independent and remote origin of the right upper and middle lobe bronchi, combined collapse of right upper and middle lobes is thought to be uncommon. We report 15 cases of combined right upper and middle lobe collapse found by plain chest radiograph in the past 8 years. Malignancies were confirmed in 13 cases. The other 2 cases with benign etiology included one case of endobronchial TB and one of pneumonia. These cases of combined bilobar collapse were possibly due to (1) the intraluminary infiltration of the primary tumor of the upper lobe to the middle lobe bronchus, (2) separated area of collapse produced by the primary tumor and its metastatic lymphadenopathy, (3) upper lobe tumor with external compression to intermediate bronchus that obstructed both the upper and middle bronchi, (4) multi-centric neoplasm, (5) tumor obstruction and sputum impaction at different bronchi, or (6) benign lesions operated at two different locations. The more frequent occurrence of bronchogenic carcinoma than that of benign lesions in our study revealed the invalidity of the "double lesion sign". Bronchoscopy or CT scan should be used to search for the etiology. If malignancy is confirmed in such condition, the prognosis is usually poor due to its advanced invasion.

Adult↗

PubMed1989

Diagnostic value of adenosine deaminase and gamma-interferon in tuberculous and malignant pleural effusions.

It has been found that both adenosine deaminase (ADA) and gamma-interferon (r-IFN) are higher in tuberculous pleural effusions than in other types of pleural effusion. Both mechanisms may be related to the T-lymphocytes in effusions. We studied 39 pleural effusions: 19 tuberculous and 20 malignant [The ADA was determined according to the Giusti method and r-IFN by ELISA]. We compared the ADA and r-IFN levels in both groups of effusions and tried to determine if there was any correlation between them. The results showed: (1) The ADA enzyme level was significantly higher in tuberculous effusions than in malignant effusions as was expected (133.0 +/- 50.4 vs 32.0 +/- 17.7 U/L). (2) The r-IFN was also significantly higher in tuberculous effusions than in malignant effusions (30.4 +/- 17.4 vs 2.9 +/- 2.8 U/ml). (3) The coefficients of regression for the ADA and r-IFN levels were poor. In conclusion, both tests for measuring ADA and r-IFN levels are excellent methods for differentiating tuberculous and malignant effusions, and especially measurement of the r-IFN level could serve as a more specific test for differentiating malignant pleural effusions with high ADA levels. However, no strong correlation was found between the ADA and r-IFN levels.

Adenosine Deaminase↗

PubMed1989

Sustained-release theophylline-uniphyllin in nocturnal asthmatics.

For a period of six months, we collected 12 cases of nocturnal asthmatics (7 males, 5 females); their ages ranged from 20 to 66 (the average age is 49). We found that administration of Uniphyllin (10 mg/kg) once a day at 6 PM could maintain the blood level of theophylline within therapeutic range at least 12 to 24 hrs. The peak expiratory flow rate of the 6 cases we collected, were significantly improved. The result of pharmokinetic parameters: 1) The average of a single dose (12 cases) is AUC (ug. hr/ml) 275.1 +/- 62. k; Kel (hr-1) 0.068 +/- 0.019; Ka (hr-1) 0.33 +/- 0.07); Tmax (hr) 6.3 +/- 1.4; T 1/2 (hr) 11.2 +/- 4.4; Clearance/F (ml/kg/hr) 37.9 +/- 9.0.2). The average of steady state (12 cases) is Css (mg/L) 5. 7 +/- 2.6; Cmax-Cmin (mg/L) 10.09 +/- 1.46.3). The average of relative bioavailability (3 cases) is 82%, 83%, 102%. However, the extent of absorption data is available for only 3 subjects. There are too few subjects to draw any meaningful conclusions about this relative bioavailability. Four cases show slight symptoms, including 1 case of dizziness, 2 cases of nausea, and 1 case gaseousness. It is suggested that the drug be administered at about 6-8 PM to coincide peak levels in the early morning in nocturnal asthmatics.

Adult↗

PubMed1989

[Prediction of postoperative pulmonary function in the patient undergoing pneumonectomy using combined pulmonary function test and ventilation/perfusion scintiphotography].

A method to predict postoperative lung function following pneumonectomy has been used in 11 patients. Preoperative unilateral lung function can be predicted by combining the preoperative information on lung volumes obtained by spirometry with the distributional information obtained from ventilation and perfusion scintigrams in order to estimate lung function after pneumonectomy. There was a high degree of correlation between predicted and measured lung function for both FEV1 (r = 0.81, p less than 0.050, and FVC (r = 0.81, p less than 0.05). The postoperative FEV1 and FVC were within 200 ml of the predicted value in most of the patients. A more accurate and easy prediction of postoperative lung function is obtained using unilateral perfusion rather than ventilation scintigrams. We suggest that the combined the results of simple spirometric data and a quantitative right-vs-left perfusion lung scan using radioactive Tc-99m provides a simple non-invasive and accurate method for the pre-operative functional evaluation of the high risk patient.

Adult↗

PubMed1988