Biomedical subjects

C D Chiang

Publications and source records attributed to C D Chiang.

At least 37 records · Page 2Linked to original sources

PubMed1996

A case report of novel roentgenographic finding in pulmonary zygomycosis: thickening of the posterior tracheal band.

Zygomycosis (Mucormycosis) has been reported to involve most of the organ systems in man, although pulmonary zygomycosis with mediastinum invasion in rare and only few cases were reported in the literature previously. The roentgenographic findings of pulmonary zygomycosis have been well-discussed. However, the lateral view of chest radiograph has never been described. We report a patient with diabetes mellitus who had pulmonary zygomycosis with mediastinal involvement, presenting as thickening of posterior tracheal band (PTB, 6mm in width). Amphotericin B therapy effectively reduced it to return to normal width.

Humans↗

PubMed1995

Potentiation of growth inhibition due to vincristine by ascorbic acid in a resistant human non-small cell lung cancer cell line.

A human cell subline (PC-9/VCR) resistant to vincristine was established from non-small cell lung cancer PC-9 cells by incremental exposure of the cells to vincristine. The resistant cells showed phenotypic resistance to vincristine (10-fold), colchicine (6.9-fold) and cisplatin (1.4-fold) but they showed sensitivity to other chemotherapeutic agents including melphalan and etoposide VP-16. The characteristics of the vincristine resistance was partially inhibited (5-7-fold) by co-treatment of PC-9/VCR cells with a nontoxic concentration of L-ascorbic acid (25 micrograms/ml). Co-treatment or 96 h pre-treatment with ascorbic acid resulted in potentiation of the vincristine effect on the resistant, but not on the sensitive, cell line. The growth inhibition due to vincristine treatment after 24 or 96 h growth in ascorbic acid-free medium was decreased in the resistant as well as in the sensitive cell line. In both cell lines, enhanced growth rate has been shown after ascorbic acid treatment. Similarly, cross-resistance of PC-9/VCR cells to colchicine could also be blocked by ascorbic acid. In addition, a nontoxic concentration of verapamil, a known multidrug resistance inhibitor, did not affect the resistant phenotype of PC-9/VCR cells. These findings suggest that an ascorbic acid-sensitive mechanism may be involved in drug resistance per se in the human lung cancer cells, which differs from the classical phosphoglycoprotein-mediated or previously reported non-phosphoglycoprotein-mediated multidrug resistance.

Ascorbic Acid↗

PubMed1995

Superior vena cava syndrome in lung cancer: an analysis of 54 cases.

Traditionally, superior vena cava syndrome (SVCS) has been recognized as an oncologic emergency, and with clinical suspicion of the syndrome, tissue diagnosis was often delayed due to possible complications in diagnostic procedures and immediately threatening of life. Previously, local radiotherapy was regarded as the best immediate strategy for management of the condition. We have analyzed 54 lung cancer patients with SVCS in the past 6 years. Our results show that dyspnea (34 cases, 63%) and facial swelling (29 cases, 54%) are the two most common symptoms. The most frequent physical finding was venous distension of the neck (35 cases, 65%). The chest X-ray findings also showed a large ratio of superior mediastinal widening (26 cases, 48%). Fine needle aspiration of palpable lymph node (20 cases, 37%) and trans-thoracic needle aspiration guided by ultrasound (US) (8 cases, 14%) made diagnosis of at least half of the cases possible (28 cases, 51%). Both of these procedures are safer and easier than other invasive methods of examination. Of the 54 patients, small cell carcinoma constituted the majority of the cases (23 cases, 43%) and, with combination chemotherapy, there was a good response rate and a longer survival time (7.4 months) as compared to that of non-small cell carcinoma (3.7 months) treated by radiotherapy. We conclude that lung cancer with SVCS could be quickly and safely diagnosed by needle aspiration of the palpable lymph node or trans-thoracic needle aspiration guided by US, and that with combination chemotherapy the SVCS in small cell carcinoma can be effectively relieved.

Adult↗

PubMed1995

Ultrasonic detection of persistent small unilateral hematocolpos in two girls.

Two girls with unilateral hematocolpos are reported. In both cases, a small amount of blood which had accumulated in the partially obstructed hemivagina was detected by real-time high resolution ultrasonography, and was confirmed by magnetic resonance imaging. Both patients were asymptomatic, and were regularly followed up at an outpatient clinic. To date, the hematocolpos persists but continues to be small.

Adolescent↗

PubMed1995

Existence of a well-defined pulmonary lesion on plain chest film predicts poor response of chemotherapy in small cell lung cancer.

BACKGROUND: Plain chest film is the most convenient and common tool used to evaluate the response of lung cancer to chemotherapy. Many authors tried to evaluate the use of plain chest films to predict chemotherapy response. This study investigated a new factor which could be used to predict the chemotherapy response of small cell lung cancer (SCLC). METHODS: Sixty-two patients with cytopathologically proven small cell lung cancer receiving at least two courses of chemotherapy were included in this study. Among these patients, thirty-nine patients received six courses of chemotherapy. The regimens of chemotherapy are Etoposide (100 mg/m2) and Cisplatin (25 mg/m2). We divided these patients into two groups according to whether a well-defined pulmonary lesion excluding hilar and mediastinal lymphoadenopathy, could be identified on plain chest X-ray (CXR). Group I consisted of 31 patients with identified lesions on the CXR; group II consisted of 31 patients with unidentifiable lung lesions. CXRs were taken each time before chemotherapy and were collected and compared to evaluate the chemotherapy response. The 39 patients receiving six course of chemotherapy, were further divided into group I (n = 19) and group II (n = 20) to evaluate the chemotherapy response. RESULTS: After two courses of chemotherapy, we found 23 patients [74.2% (23/31)] in group I had partial response(PR) as compared to 12 patients [38.7% (12/31)] in group II (P < 0.05). For the 39 patients receiving six courses of chemotherapy, we could find only five patients [16.1% (5/19)] in group I who had a complete response (CR) as compared to 17 patients [85% (17/20)] in group II (P < 0.001). CONCLUSION: For patients with SCLC, a well-defined lung lesion on a CXR could be an important new factor to predict the chemotherapy response. It could predict less responsiveness to chemotherapy.

Adult↗

PubMed1995

Alveolar integrity in pulmonary emphysema using technetium-99m-DTPA and technetium-99m-HMPAO radioaerosol inhalation lung scintigraphy.

UNLABELLED: The alveolar integrity (AI) in 17 male patients with pulmonary emphysema (EMPH) diagnosed by chest x-ray was measured by 99mTc-DTPA and 99mTc-HMPAO radioaerosol inhalation lung scintigraphy. METHODS: The patients were divided into two groups: (A) nine patients with pulmonary emphysema and normal carbon monoxide diffusion capacity (DLCO) and (B) eight patients with pulmonary emphysema and abnormal DLCO. The degree of AI damage in EMPH was presented as the slope of the time-activity curves from the dynamic left lung imagings in DTPA and HMPAO. The AI of EMPH patients were compared with the AI of 16 normal controls. RESULTS: The results show that: (1) the slope of DTPA is larger than that of HMPAO in each of the portions of the left lung for any of the study groups; (2) statistical differences were found between the normal controls and EMPH patients in HMPAO but not in DTPA; and (3) the correlation was not good between DLCO and DTPA/HMPAO in EMPH patients. CONCLUSION: Our results suggest that: (1) at least two different mechanisms in the lungs were at work; (2) the AI damage in EMPH developed mainly in the lipophilic part of the alveoli; and (3) the AI damage presented as slopes of DTPA/HMPAO in our study was different from the traditional pulmonary function such as DLCO.

Administration, Inhalation↗

PubMed1994

Ascorbic acid increases drug accumulation and reverses vincristine resistance of human non-small-cell lung-cancer cells.

A human lung-cancer PC-9 subline with acquired resistance to vincristine (VCR), a chemotherapeutic agent, was established with incremental increases of the drug. The resistant PC-9 subline (PC-9/VCR) shows a 12-fold increase in resistance to VCR and a unique cross-resistance pattern: high cross-resistance to the potent VCR analogue colchicine (6.9-fold) and vinblastine (2.5-fold); lower cross-resistance to actinomycin D (1.8-fold), cisplatin (1.2-fold) and adriamycin (1.3-fold) and a sensitivity to melphalan and VP-16 which is similar to that of the parental cell line. A reduced accumulation of VCR in the resistant cells was demonstrated. Interestingly, the VCR resistance of the PC-9/VCR cell line was partially reversed by ascorbic acid, and the drug uptake was enhanced. In contrast, ascorbic acid had no effect on drug tolerance and drug accumulation was not observed in either PC-9 parental cells or known multidrug-resistant (MDR) cells, suggesting that VCR resistance in PC-9/VCR cells results essentially from reduced drug accumulation. It is worth noting that, whereas reduced drug accumulation in the PC-9/VCR cells was susceptible to modulation by ascorbic acid, the increased efflux rate characteristic of the resistant cells was not. Further, there was a higher efflux rate in resistant cells than in parental cells. DNA Southern- and RNA Northern-blot hybridization analyses indicate that PC-9/VCR cells do not contain amplified mdr genes or overexpress P-glycoprotein. In addition, the calcium-channel blocker verapamil, which acts as a competitive inhibitor of drug binding and efflux, did not affect the resistant phenotype of PC-9/VCR cells. These findings suggest an ascorbic acid-sensitive drug uptake mechanism which is important in mediating VCR resistance per se in human lung-cancer cells; this differs from the P-glycoprotein-mediated MDR mechanism.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1994

Neopterin, soluble interleukin-2 receptor and adenosine deaminase levels in pleural effusions.

We evaluated soluble interleukin-2 receptors (sIL-2R), neopterin and adenosine deaminase (ADA) in pleural effusions from 93 patients with tuberculosis, malignancies, uremia, pneumonia and other kinds of pleurisy. There were significantly elevated ADA (102.7 +/- 47 U/l) and sIL-2R (8,238 +/- 4,117 U/ml) values in tuberculous (TB) pleural fluids as compared with other non-TB pleural fluids (p < 0.005). The neopterin levels in pleural fluid were significantly lower in the cancer group (17.3 +/- 7.8 nmol/l; p < 0.005) and most strikingly elevated (309.4 +/- 112.2 nmol/l; p < 0.0001) in patients with uremic pleural effusions. Using cut-off values of 60 U/l in ADA and 5,000 U/l in sIL-2R, 92.0 and 86.9% of pleural effusions were TB in origin. Eighty-four percent of patients with malignant pleural effusions had neopterin levels less than 25 nmol/l.

Adenosine Deaminase↗

PubMed1994

Ultrasound-guided biopsy of thoracic masses.

BACKGROUND: Fine needle aspiration cytologic examination may be sufficient for managing patients with primary lung cancer. However, the procedure is not reliable for benign lesions and metastatic lung cancers. An attempt was made to find the influence of cell type on the results of fine needle aspiration and cutting biopsy. METHODS: One hundred and sixteen patients with thoracic nodules or masses underwent chest ultrasound examination and percutaneous ultrasound-guided needle biopsy. All patients underwent ultrasound-guided fine needle aspiration biopsy (UGAB) and thirty-eight of them also underwent ultrasound-guided cutting biopsy (UGCB). Thoracic lesions were divided into seven groups. RESULTS: Using UGAB alone, the diagnostic rate varied from 56% (mediastinal tumor) to 91% (lung mass). When both methods of UGAB and UGCB were evaluated, the diagnostic rate varied from 67% (pulmonary nodule) to 100% (collapsed lung with mass and pancoast tumor). When thoracic lesions were divided into carcinomatous neoplasms (n = 88) and noncarcinomatous lesions (n = 21), a higher diagnostic rate was found in the carcinomatous group than in the noncarcinomatous group (92% versus 53%, p < 0.001). Correct histologic results between both groups had no statistical significance (64% versus 56%, p > 0.05). CONCLUSIONS: Ultrasound-guided needle biopsy has a high diagnostic yield of thoracic tumors, and carcinomatous masses can be easily diagnosed by UGCB. Noncarcinomatous masses and benign tumors frequently need UGAB to obtain a histologic diagnosis.

Adolescent↗

PubMed1994

Detection of specific antibody to mycobacterial antigen 60 in tuberculous pleural effusion.

BACKGROUND: With the development of the enzyme-linked immunosorbent assay (ELISA) method, serodiagnosis of tuberculosis has been studied by many investigators. Only a few studies have been performed in pleural fluid. This study was designed to evaluate the IgG antibody levels to mycobacterial antigen 60 (Ag60) in pleural fluid, and evaluate its role in the diagnosis of tuberculous pleurisy. METHODS: Eighteen patients with tuberculous pleural effusions and 18 patients with malignant pleural effusions were studied. The levels of IgG antibodies to Ag60 in pleural fluids were measured by ELISA method. RESULTS: The mean titers of IgG against Ag60 in pleural fluids of tuberculous patients (508.3 +/- 382.7 EU) were significantly higher than those of the mean value of the malignant group (131.2 +/- 83.2 EU). In the TB pleurisy group, patients with positive M. tuberculosis cultures from pleural fluids had significantly higher titers than those with negative cultures (796.5 +/- 394.7 vs 277.8 +/- 150.2 EU); patients with impaired immune function had significantly lower titers than those without (138.4 +/- 28.9 vs 650.6 +/- 358.1 EU). Using 250 EU as a cutoff value for a positive test, the sensitivity was 72.2% and the specificity, 94.4%. CONCLUSIONS: ELISA method using Ag60 is a rapid test with an acceptable sensitivity and excellent specificity for differentiation between tuberculous and malignant pleural effusion.

Adolescent↗

PubMed1994

[The effects of exercise on the arterial potassium and ventilatory response under hyperoxic, normoxic, and hypoxic conditions].

BACKGROUND: Exercise leads to an increase in plasma potassium, the animal experiments showed that potassium infusion stimulated ventilation and abolished by peripheral chemodenervation and also showed that combined effects of potassium and hypoxia were greater than the sum of the individual effects. This study proposed to investigate plasma potassium and its correlation with exercise, and to investigate the effects of hypoxia and hyperoxia on potassium and ventilation during steady state exercise. METHODS: Ten male subjects exercised on a cycle ergometer. Each performed (1) incremental exercise test; (2) steady state exercise test with a work rate of about 75% of anaerobic threshold under hyperoxic (FiO2 100%), normoxic (FiO2 21%) and hypoxic (FiO2 12%) conditions, respectively. RESULTS: Arterial plasma potassium concentration rose from a pre-exercise level of 3.97 +/- 0.40 mEq/L to the post-exercise level of 5.11 +/- 0.49 mEq/L. The increase in plasma potassium during exercise correlated well with the increase in lactate (r = 0.72, p < 0.05) and the decrease in pH (r = 0.69, p < 0.05). During the steady state exercise test, switching the subject from room air to hypoxic (12% O2) conditions led to a significant rise in both plasma potassium (p < 0.05) and ventilation (p < 0.05) with good correlation between the potassium increase and the increase in ventilation (r = 0.85, p < 0.05). Switching the subject from room air to hyperoxic (100% O2) condition resulted in a significant decrease in ventilation (p < 0.05) without significant change in plasma potassium (p > 0.01). CONCLUSIONS: It was concluded that (1) exercise can lead to an increase in arterial potassium, hydrogen ion, lactate in men; (2) hypoxia can stimulate the peripheral chemoreceptor and increase plasma potassium level. Potassium may, therefore, be an important factor by which the magnitude of the peripheral chemoreflex response is augmented during exercise.

Aged↗

PubMed1993

[The efflux of intracellular vincristine in drug-resistant human lung cancer cells is not mediated by P-glycoprotein].

A subline (PC-9/VCR) of the human lung adenocarcinoma cell line (PC-9), derived by in vitro exposure to vincristine (VCR), exhibited a 10-12-fold resistance to VCR by MTT and HTCA assay. Compared to the parental cell line (PC-9), PC-9/VCR-resistant cells displayed a reduced accumulation of VCR. The rate of VCR efflux was shown to be enhanced by PC-9/VCR. Unlike multidrug resistance, this efflux was independent of P-glycoprotein overexpression as determined by the Northern blotting method. In addition, PC-9/VCR showed no collateral sensitivity to verapamil. This resistant subline only showed 6.9-fold and 2.5-fold cross resistance to colchicine and vinblastine, respectively. This preliminary result indicates that defective drug accumulation in PC-9/VCR is due to other mechanisms possibly involving the microtubule assembly.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1993

Diagnostic value of pleural adenosine deaminase in tuberculous effusions of immunocompromised hosts.

To investigate the diagnostic value of adenosine deaminase (ADA) in immunocompromised hosts with tuberculous pleural effusions, we collected and checked 60 pleural effusion specimens from admitted patients. These patients were divided into three groups: group I (n = 20), immunocompetent hosts with tuberculous pleural effusions; group II (n = 10), immunocompromised hosts with tuberculous pleural effusions; and group III (n = 30), patients with malignant pleural effusions. Using statistical analysis to compare the ADA value in each group, the p value was found to be significant between groups I and II (p < 0.01), groups I and III (p < 0.001) and groups I+II and III (p < 0.001); however, the p value was not significant between groups II and III. If the lowest ADA value for the tuberculous pleural effusion was designed as 80 U/L, the sensitivity/specificity was 1.0/0.90 (group I), 0.40/0.90 (group II), and 0.80/0.90 (group I+II), respectively. We conclude that the diagnostic value of ADA in immunocompromised hosts with tuberculous pleural effusions is not as significant as in immunocompetent hosts.

Adenosine Deaminase↗

PubMed1993

Apical malignancies diagnosed by ultrasound-guided fine needle aspiration biopsy.

Sixteen patients with apical malignancies, including 12 with Pancoast tumors and four with metastatic apical pleural masses, underwent chest ultrasound (US) examinations and direct percutaneous fine needle aspiration biopsy (FNAB). Of those, 15 patients were proven to have malignancies by FNAB and the remaining patient (only revealing necrosis by FNAB) was also proven to have a Pancoast tumor after surgical intervention. Percutaneous FNAB was performed through the supraclavicular approach (n = 10) or through the upper back (n = 6). The sonographic appearances of the apical malignancies were homogeneous hypoechoic (n = 8), homogeneous isoechoic (n = 3) or heterogeneous (n = 5). No complications occurred after the FNAB. Our limited experience showed that a convex probe was convenient and useful in the detection of apical malignancies. Apical malignancies, diagnosed previously by percutaneous needle aspiration under fluoroscopy or surgical intervention, can be easily diagnosed by percutaneous FNAB, especially when the FNAB is performed using the supraclavicular approach.

Aged↗

PubMed1993

[Detection of Mycobacterium tuberculosis in sputum by polymerase chain reaction].

A method based on DNA amplification (PCR) and hybridization for the detection of M. tuberculosis was used to test 86 sputum specimens from 52 patients in whom tuberculosis was suspected. M. tuberculosis was detected in 35 specimens, with 1 false positive. The finding was negative in 51 specimens, of which 4 were false negative. Thirty-two specimens were positive by standard microbiological criteria (acid-fast stain and culture), and 54 specimens were negative (including 6 false negative). Of 38 specimens with definite diagnosis of tuberculosis, 89.5% (34/38) were positive by DNA amplification and 84.2% (32/38) by acid-fast stain and/or culture. The difference is not statistically significant (P > 0.05). The specificity was 97.9% (47/48) and 100% (48/48) by DNA amplification and acid-fast stain and/or culture, specificity was 97.9% (47/48) and 100% (48/48) by DNA amplification and acid-fast stain and/or culture, individually, and difference is also not statistically significant (P > 0.05). However, PCR combined with specific DNA probe is more sensitive than the acid-fast stain method and faster than the culture method. Therefore it is useful for early detection of pulmonary mycobacterial infection.

Base Sequence↗

PubMed1993

Synthesis and cytotoxicity studies of novel cyclic peptide-2,6-dimethoxyhydroquinone-3-mercaptoacetic acid conjugates.

In an effort to investigate the use of small-ring-size cyclic peptides as carriers of new antitumor agents, we synthesized three cyclic tripeptide-cytotoxic agent conjugates. The cytotoxic agent conjugated to the epsilon-amino group of the lysyl residue of the cyclic peptides is 2,6-dimethoxyhydroquinone-3-mercaptoacetic acid (DMQ-MA), (Sheh et al., 1992). The cyclic peptides were synthesized by coupling protected amino acid residues in solution and the subsequent cyclization performed by the pentafluorophenyl ester method as described previously (Sheh et al., 1985, 1987, 1990). After deblocking the lysyl-Z group of the peptides, the conjugation was achieved by reaction with the pentafluorophenyl ester of DMQ-MA. The three cyclic peptides exhibited potent cytotoxicity against two solid tumor cell lines (KB and PC-9) under the synergistic activation of L-ascorbic acid. Electron spin resonance (ESR) studies of DMQ-MA and two conjugates showed that massive hydroxyl radicals were generated as a non-linear function of L-ascorbic acid concentration. These studies indicate that the hydroxyl radical is a possible mediator of cytotoxicity for these conjugates and that small-ring-size cyclic peptides are potentially useful carriers of cytotoxic agents.

Cell Survival↗

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↗