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Biomedical subjects

T C Chang

Publications and source records attributed to T C Chang.

At least 235 records · Page 13Linked to original sources
PubMed1975

Correlation of delayed hypersensitivity responses with chemotherapeutic results in advanced Hodgkin's disease.

Delayed skin test responses to several or all of a battery of six antigens were evaluated in 64 patients with disseminated Hodgkin's disease before, during, and after multiple-agent chemotherapy. Before therapy, 53% of patients had one or more positive skin tests, as compared to 55% during intensive chemotherapy, 79% during maintenance therapy, and 100% after discontinuation of all treatment. Pretreatment skin tests were of no value in predicting clinical response to chemotherapy. Response rates, duration of response, and survival were similar among anergic patients and patients with positive skin tests before treatment. There were too few patients who remained anergic after intensive induction chemotherapy to permit a correlation of immunologic reactivity with course. We conclude that skin test responses to recall antigens, before or during aggressive treatment, are more indicative of Hodgkin's disease activity (and also, of the immunosuppressive effects of treatment routines) than of prognosis.

Carmustine↗
PubMedDate not supplied

Protein oxidation and turnover.

All biomacromolecules are faced with oxidative stress. Oxidation of a protein molecule always induces inactivation of the molecule and introduces a tag to that molecule. These modified protein molecules are prone to degradation in vivo by the proteasome system. Coupling of protein modification and degradation of chemically modified proteins is one of the normal protein turnover pathways in vivo. We call this a 'chemical apoptosis' process, which is one of the early manifestations of programmed cell death. Impairment of the proteasome system leads to accumulation of modified nonfunctional proteins or 'aged proteins' that might cause various clinical syndromes including cataractogenesis, premature aging, neurological degeneration and rheumatoid disease. The metal-catalyzed oxidation of biomacromolecules provides an excellent artificial aging system in vitro. The system is very useful in the characterization of structure and function relationships of proteins (enzymes), especially in those containing metal binding domain(s), because the oxidation is always followed by an affinity cleavage at the metal binding site(s) that allows easy identification and further characterization.

Animals↗
PubMedDate not supplied

Human papillomavirus genotyping by a polymerase chain reaction-based genechip method in cervical carcinoma treated with neoadjuvant chemotherapy plus radical surgery.

The aim of this study was to evaluate the accuracy of human papillomavirus (HPV) genotyping by a polymerase chain reaction (PCR)-based genechip method and to determine the prognostic value of HPV genotype in bulky stage IB or IIA cervical carcinoma treated with neoadjuvant chemotherapy (NAC) and radical surgery. A total of 149 patients had adequate tissue for the study. The SPF1/GP6+ primers were used to amplify a 184 bp fragment. The amplimers were submitted for direct sequencing and hybridization with a genechip using revert-blot detection of 39 types of HPV DNA in a single reaction. Two runs of PCR with respective hybridization were performed for each tumor. The complete concordance of HPV genotyping was 80.5% (120/149) of the paired genechip results. The kappa coefficient was 0.634 (P < 0.0001). HPV DNA sequences were detected in 100% of the specimens, among which 67.8% harbored single type and 32.2% contained multiple types. HPV-16 was detected in 98.7%, HPV-18 in 22.8%, HPV-31 in 0.7%, HPV-45 in 1.3%, HPV-52 in 2.0%, HPV-58 in 6.7%, HPV-59 in 4.7%, and HPV-67 in 0.7%. In multivariate analyses, the HPV genotype [HPV-18 or HPV-16 and HPV-18 only versus all others: relative risk (RR), 2.33; 95% CI, 1.17-4.64; P = 0.016] and pre-NAC tumor size (>5 versus </=5 cm: RR, 2.25; 95% CI, 1.13-4.48; P = 0.021) were significantly related to overall survival. This PCR-based genechip method is sensitive and reproducible for HPV genotyping. The association of HPV-18 or HPV-16 and HPV-18 with poor outcome in cervical carcinoma treated with NAC plus radical surgery is confirmed.

Antineoplastic Agents↗
PubMedDate not supplied

Ovarian endometrioid carcinoma with diffuse pigmented peritoneal keratin granulomas: a case report and review of the literature.

The presence of keratin granulomas in peritoneal cavity associated with ovarian endometrioid carcinoma, which might be related to leakage from the ovarian tumor, is rarely reported. Its clinical significance has not yet been well investigated. We report a case presenting with intermittent abdominal pain after an acute episode 1 month before a complex adnexal tumor was noted. Comprehensive cytoreductive surgery was performed. The ovarian tumor was an endometrioid adenocarcinoma with squamous differentiation. There were diffuse brownish flecks over the omental surface and pelvic peritoneum, which contained fragments of degenerated squamous cells, keratin, and numerous foreign body giant cells. Extensive multiple sections were examined for these implants. DNA flow cytometry and various immunostaining studies (HER-2/neu, p53, CK-7, and cytokeratin [AE1/AE3]) were performed. Since viable epithelial cells in the implants could be differentially identified against mesothelial or granulomatous components by CK-7 staining and DNA aneuploidy was demonstrated on primary ovarian tumor, four courses of chemotherapy were administered. The patient has been free of disease for 18 months since diagnosis.

Abdominal Pain↗
PubMedDate not supplied

Three-dimensional cytomorphology in fine needle aspiration biopsy of medullary thyroid carcinoma.

OBJECTIVE: To elucidate three-dimensional (3-D) cytomorphology in fine needle aspiration biopsy (FNAB) of medullary thyroid carcinoma (MTC). STUDY DESIGN: ENAB was performed on tumors from five patients with MTC. The aspirate was stained and observed under a light microscope (LM). The aspirate was also fixed, dehydrated, critical point dried, spattered with gold ions and observed with a scanning electron microscope (SEM). For transmission electron microscopy (TEM), the specimen was fixed, dehydrated, embedded in an Epon mixture, cut with an ultramicrotome, mounted on copper grids, electron doubly stained with uranium acetate and lead citrate, and observed with TEM. Findings under SEM were correlated with those under LM and TEM. RESULTS: Under SEM, 3-D cytomorphology of MTC displayed a disorganized cellular arrangement with indistinct cell borders in three cases. The cell surface was uneven and had granular protrusions that corresponded to secretory granules observed under TEM. In one case with multiple endocrine neoplasia type IIB, there were abundant granules on the cell surface. In one case of sporadic MTC with multinucleated tumor giant cells and small cells, granular protrusions also were noted on the cell surface. CONCLUSION: Granular protrusion was a characteristic finding in FNAB of MTC tinder SEM and might be helpful in the differential diagnosis.

Adult↗
PubMedDate not supplied

Three-dimensional cytomorphology and its relationship with clinical stage in fine needle aspiration biopsy of papillary thyroid carcinoma.

OBJECTIVE: To elucidate three-dimensional (3-D) cytomorphology and its relationship with clinical stage in fine needle aspiration biopsy (FNAB) of papillary thyroid carcinoma (PTC). STUDY DESIGN: FNAB was performed in tumors from 34 patients with PTC. The aspirate was stained and observed under a light microscope (LM). The aspirate was also fixed, dehydrated, critical point dried, spattered with gold ions and observed with a scanning electron microscope (SEM). Findings under SEM were correlated with the presentation under LM and also with clinical stage. As a control, FNAB was also performed on a normal part of the thyroid in six patients. RESULTS: Under SEM, normal thyroid cells appeared as round, scattered cells or sheets with a uniform honeycomb cellular arrangement. In PTC, cell sheets with uniform nuclear morphology under LM usually showed a uniform cell arrangement and with distinct cell borders under SEM. Cell sheets with nuclear pleomorphism under LM usually showed a more-disorganized arrangement and with indistinct cell borders under SEM. PTC at advanced clinical stages usually presented with a disorganized cell arrangement, indistinct cell borders and loss of microvilli. CONCLUSION: 3-D cytomorphology in FNAB of PTC was related to clinical stage and might be a prognostic factor for PTC.

Adult↗
PubMedDate not supplied

Immunoperoxidase staining in the differential diagnosis of parathyroid from thyroid origin in fine needle aspirates of suspected parathyroid lesions.

OBJECTIVE: To determine whether immunoperoxidase staining could be used for differential diagnosis of parathyroid from thyroid origin in fine needle aspirates of suspected parathyroid lesions. STUDY DESIGN: Immunoperoxidase staining of parathyroid hormone and thyroglobulin was performed on aspirated smears from 10 patients with parathyroid lesions (6 of 10 patients also associated with thyroid lesions) and 10 patients with thyroid lesions. All of them had surgical tissue proof of the diagnosis. RESULTS: Aspirated smears of six patients with parathyroid lesions had strong to moderate staining for parathyroid hormone and negative staining for thyroglobulin. Another four patients with parathyroid lesions had equivocal staining for parathyroid hormone and negative staining for thyroglobulin. All aspirated smears from the 16 thyroid lesions had negative staining for parathyroid hormone and positive staining for thyroglobulin. CONCLUSION: Immunoperoxidase staining of parathyroid hormone and thyroglobulin, done for each suspected parathyroid lesion, was helpful in the differential diagnosis of parathyroid vs. thyroid origin.

Adenoma↗
PubMedDate not supplied

Serial changes in ultrasound-guided fine needle aspiration cytology in subacute thyroiditis.

OBJECTIVE: To elucidate the serial cytologic presentations of subacute thyroiditis (SAT) with ultrasound-guided fine needle aspiration (FNA). STUDY DESIGN: Nine patients with clinically evident SAT were recruited; serial sonography and ultrasound-guided fine needle aspiration cytology were performed. RESULTS: Sixty-one follow-up examinations were obtained in nine patients. The follow-up ranged from 1 to 5 months (mean, 3.3). Initial sonographic presentations revealed focal hypoechogenicity in three patients and multiple hypoechogenicity in six. Initial cytologic findings showed chiefly enlarged, degenerated follicular cells with prominent nucleoli, lymphocytes, colloid substance, multinucleated giant cells and neutrophils. Regression of sonographic hypoechogenicity paralleled the disappearance of acute inflammatory cells and enlarged, degenerated follicular cells and the appearance of cohesive follicles. CONCLUSION: Improvement of SAT in sonography is fairly parallel to that in cytology even though there is a lag of improvement in the latter. Smear pattern is also related to the clinical stage of SAT. Ultrasound-guided FNA is a convenient method of obtaining sufficient and representative specimens in patients with SAT.

Adult↗
PubMedDate not supplied

Apoptosis induced by the sodium butyrate in human gastric cancer TMK-1 cells.

The effects of sodium butyrate on cell proliferation, gene expression, and apoptosis were investigated. Upon exposure to sodium butyrate the cells exhibited marked morphological changes, reduced cell proliferation and most cells died through apoptosis within 48 hours. In the presence of dexamethasone, however, the sodium butyrate-triggered apoptosis was markedly reduced. Studies using the glucocorticoid receptor antagonist RU486 indicated that the protective effect of dexamethasone was mediated through glucocorticoid receptor. Sodium butyrate markedly induced the c-jun proteins level, whereas the c-Myc protein was down-regulated rapidly. c-Jun protein may play an important role in the action of sodium butyrate since its induction preceded the onset of DNA fragmentation. In addition, preincubation of the cells with dexamethasone markedly delayed the induction of c-jun levels by sodium butyrate. Analysis of the expression of bel-2-related genes indicated that the Bcl-xS protein level was increased in the presence of sodium butyrate and the up-regulation of Bcl-xS by sodium butyrate was also blocked by dexamethasone. Taken together, these results indicate that c-myc, c-jun and Bcl-xS proteins may be involved in the mechanism of sodium butyrate-triggered apoptosis in these cells.

Apoptosis↗
PubMedDate not supplied

Value of immunoperoxidase staining of thyroglobulin in fine needle aspiration cytology of thyroid diseases.

To elucidate the value of thyroglobulin staining by the immunoperoxidase method in fine needle aspiration cytology of thyroid diseases, it was performed on fine needle aspiration smears of 57 cases of various thyroid diseases. Thirteen of 22 cases (59%) with benign nodular goiter were positive. Eight of 14 cases (57%) with papillary thyroid carcinoma were positive. Among these eight cases with positive staining, seven were at clinical stage II or less. Among the other six cases with negative staining, five cases were in clinical stage III or more. There was a significant relationship between clinical stage and thyroglobulin staining (P < .05). One of 10 cases with thyroid cysts was positive. One of four cases with anaplastic carcinoma was positive. One of two cases with follicular thyroid carcinoma was positive. Two cases of subacute thyroiditis were positive. One case of Hashimoto's thyroiditis was positive. Two cases of metastatic thyroid cancer from the ovary were negative. These results reveal that positive thyroglobulin staining was helpful in defining the source of tissue from the thyroid. However, negative staining could not definitively exclude a thyroid origin. Positive thyroglobulin staining in papillary thyroid carcinoma correlated with less advanced clinical stages.

Biopsy, Needle↗