Koung-Yi Liaw

Distribution of the cadherin‐catenin complex in normal human thyroid epithelium and a thyroid carcinoma cell line

E‐cadherin is the major cell‐cell adhesion molecule expressed by epithelial cells. Cadherins form a complex with three cytoplasmic proteins, α‐, β‐, and γ‐catenin, and the interaction between them is crucial for anchoring the actin cytoskeleton to the intercellular adherens junctions. The invasive behavior of cancer cells has been attributed to a dysfunction of these molecules. In this study, we examined the distribution of the cadherin‐catenin complex in a Chinese human thyroid cancer cell line, CGTH W‐2, compared with that in normal human thyroid epithelial cells. In the normal cells, using immunofluorescence staining, E‐cadherin and α‐, β‐, and γ‐catenin were found to be localized at the intercellular junction and appeared as 135, 102, 90, and 80 kD proteins on Western blots. In CGTH W‐2 cells, no E‐cadherin and γ‐catenin immunoreactivity was detected by immunofluorescence or Western blotting; α‐ and β‐catenin were detected as 102 and 90 kD proteins on blots but gave a diffuse cytoplasmic immunofluorescence staining pattern in most cells, while β‐catenin was also distributed throughout the cytoplasm in most cells but was found at the cell junction in some, where it colocalized with α‐actinin. The present data indicate that the loss of cell adhesiveness in these cancer cells may be due to incomplete assembly of the cadherin‐catenin complex at the cell junction. However, this defect did not affect the linkage of actin bundles to vinculin‐enriched intercellular junctions. J. Cell. Biochem. 70:330–337, 1998.

Characteristics of Thyroidectomy in Taiwan

BACKGROUND AND PURPOSE Thyroidectomy is a common treatment for thyroid disorders in Taiwan, and constitutes a significant percentage of medical expenses. This study investigated the characteristics of thyroidectomy in Taiwan. METHODS A total of 21 senior general surgeons from 16 medical centers and 5 regional hospitals participated. One surgeon from each hospital reviewed the hospitals medical records of thyroid operations performed in the year 2001. Medical records for 3846 thyroidectomies were retrospectively analyzed, including surgical indications and modalities, complications, pathology reports, and the use of antibiotics. RESULTS Most of the patients were women (85%). Indications for surgery included proven malignancy (9%), suspicious malignancy (30%), evident compression symptoms (20%), hyperthyroidism (20%), and cosmetic reasons (12%). The majority of patients (78%) underwent a surgical procedure with lobectomy or bilateral thyroidectomy; 13% had unilateral partial thyroidectomy. Prophylactic antibiotics were administered in 46% of procedures, and continued postoperatively in 12%. Postoperative complications occurred in 12% of patients. Hypocalcemia was the most common complication (8%), and its incidence was significantly correlated with the frequency of total thyroidectomy (p < 0.01). Complete pathology reports for the thyroidectomized specimens were available in only 65% of the cases. The frequency of cosmetic reasons for surgery, unilateral subtotal resection, routine antibiotic administration, and incomplete pathology reports were significantly higher in regional hospitals than in medical centers. CONCLUSIONS Reduction in the high rates of cosmetic reasons for surgery, unilateral partial thyroidectomy, incomplete pathology reports, and use of antibiotic prophylaxis are needed to improve the quality of thyroidectomy in Taiwan.

Primary Intrathoracic Goiter

Nodular goiter is a common disease in Taiwan, and substernal or intrathoracic goiters are not infrequent. However, intrathoracic goiters are mainly of the secondary type and primary intrathoracic goiters are rarely seen. We report a 55-year-old woman who was incidentally found to have an ectopic goiter located in the anterior upper mediastinum with the initial presenting symptom of productive cough. Imaging studies including chest X-ray and computed tomography identified the lesion, and 131I-uptake scan showed weak uptake in the thorax. Surgical removal via thoracotomy was performed and the diagnosis was confirmed by pathology. A primary intrathoracic goiter, although rare, should also be considered in the differential diagnosis of mediastinal tumor.

Impaired cell-mediated immunity function in thyroid cancer

Immunological parameters were studied in 31 patients with thyroid cancer. Serum immunoglobulin levels, T and B cell percentages in peripheral blood, showed no significant difference as compared with those of control group. The blastogenesis with phytohemagglutinin P (PHA) was significantly reduced, especially, in those having larger tumor size or metastasis or in those over age 60. The positive rate of skin test with purified‐protein‐derivative (PPD) and Streptokinase‐Streptodornase (SK‐SD) was also markedly reduced. The impaired blastogenesis of lymphocyte and reduced positive rate of skin test in those cancer patients suggested that the cell‐mediated immunity function, in spite of adequate count of T‐cell, was impaired.