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T C Chao

Publications and source records attributed to T C Chao.

At least 37 records · Page 2Linked to original sources
PubMed2001

Laparoscopic cholecystectomy for polypoid lesions of the gallbladder: a clinicopathologic study.

The size and number of gallbladder polyps are used to differentiate between benign and malignant lesions before surgery and to determine whether surgery is necessary for the lesion. Since 1987, laparoscopic cholecystectomy has been widely used as the management method of choice for gallbladder lesions. The results of a clinicopathologic study of polypoid lesions of the gallbladder, based completely on laparoscopically resected gallbladder tissue, have not yet been evaluated fully. Data from 123 patients with polypoid lesions of the gallbladder treated by laparoscopic cholecystectomy were reviewed retrospectively. The gallbladders were classified into four histologic groups. Clinical features, maximal diameter, and the number of lesions were compared among the groups. The mean age of patients with adenoma and cancer was significantly greater than that of patients with cholesterol polyps and other lesions. More women than men had a neoplasm (adenoma and cancer). Patients in the neoplasm group tended to have a single lesion. The mean maximal diameter of neoplasms was significantly larger than that of lesions in the nonneoplasm group. All seven malignant lesions that were detected measured at least 1.5 cm. Univariate analysis showed that polypoid lesions of the gallbladder with neoplastic lesions correlated significantly with age, sex, size, and number of the lesions. Univariate analysis also showed that malignancy in polypoid lesions of the gallbladder correlated significantly with age, size, and number of the lesions. Multivariate logistic regression analysis showed that the age of the patient and the size of the lesion (> or = 1.0 cm) are two independent factors in predicting neoplastic lesions in polypoid lesions of the gallbladder. The size of the lesion (> or = 1.5 cm) is the only independent factor in predicting malignancy in the polypoid lesions of the gallbladder as shown by multivariate logistic regression analysis. Laparoscopic cholecystectomy is a safe and feasible method for gallbladder polypoid lesions. Neoplastic change in polypoid lesions of the gallbladder should be considered when a patient older than 50 years of age has a polypoid lesion larger than 1.0 cm. Cancer should be suspected when a polypoid lesion of the gallbladder is larger than 1.5 cm, and an aggressive surgical approach is warranted so that early gallbladder cancer can be detected and patients can have an increased chance of cure.

Adenocarcinoma↗
PubMed2000

Detection of mRNA of sodium iodide symporter in benign and malignant human thyroid tissues.

Human sodium iodide symporter (hNIS) is an intrinsic membrane protein with 12 transmembrane regions, which shows homology to other sodium-dependent transporters. There is controversy as to the amount of hNIS expression in different kinds of human thyroid cancer tissues and cell lines. In this study, reverse transcription-polymerase chain reaction (RT-PCR) was used to detect mRNA of hNIS in various fresh normal, benign tissues and malignant human thyroid tissues. The forward primer was nested hNIS-5' primer containing the sequences: ACCTGGAAATGCGCTTCAGC. The reverse primer was nested hNIS-3' primer containing the sequences: AAGCATGACACCGCGTGCCA. The results revealed three of three normal tissues, six of eight nodular hyperplasia, two of two hyperthyroidism, one of three follicular adenomas, five of ten papillary thyroid carcinomas, one of one follicular carcinoma and zero of one metastatic follicular tissues demonstrated positive results for hNIS in thyroid epithelial cells. A higher percentage of positive results of the symporter mRNA were found in normal benign thyroid tissues and the thyroid tissues of hyperthyroidism, and nodular hyperplasia (84.6%); however follicular adenoma, papillary and follicular thyroid carcinomas demonstrated a lower percentage of expression in the RT-PCR studies (46.7%). Serum thyrotropin levels and the degree of differentiated components presented in cancer tissues have been mentioned as important factors for hNIS expression in the cancer tissues. The discrepancies of the expression of hNIS in in vivo and in vitro studies need further investigation. In conclusion, hNIS was found in higher ratios in normal and benign thyroid tissues than in the malignant tissues. In addition, the RT-PCR technique hNIS did not detect the transporter in most papillary thyroid cancer tissues.

Adenocarcinoma, Follicular↗
PubMed2000

Expression of sodium iodide symporter in metastatic and follicular human thyroid tissues.

Active iodide uptake across the basal membrane mediated by human sodium iodide symporter (hNIS) has been shown to be a process coupled with the flow of sodium. There is still controversy as to the amount of hNIS expression present in different kinds of human thyroid cancer tissues. In this study, we present a 58-year-old women with follicular thyroid carcinoma with vertebra and skull metastases. 201Tl and 5 mCi 131I scans clearly demonstrated the metastatic lesions in the brain of this patient. Thyroid and metastatic tissues were then obtained for this study, which is aimed at comparing the iodide trapping ability in vivo and in vitro of hNIS, and then comparing their expression in both thyroid tissue and metastatic tissues. Polyclonal antibodies to hNIS and competitive RT PCR were used to analyze the symporter protein and mRNA expressed in follicular human thyroid and metastatic tissues. Positive staining of the symporter protein was performed in the follicular thyroid carcinomas, otherwise, the metastatic tissues could not have demonstrated the protein in the staining. Follicular thyroid carcinoma tissues from thyroid were revealed around 5 pg hNIS expressed in follicular thyroid carcinoma tissues from the thyroid. Otherwise, there was almost an absence of hNIS expression in the metastatic tissue. These discrepancies of the expression in hNIS in vivo and in vitro studies need further investigation.

Adenocarcinoma, Follicular↗
PubMed2000

Characteristics of thyroid carcinomas in aging patients.

BACKGROUND: To investigate the clinical features of thyroid cancer in aging patients and to present the results of treatment. From this we can provide bases for earlier diagnoses and better treatment of thyroid malignancies in older patients. MATERIALS AND METHODS: In this study a retrospective analysis was performed with 204 thyroid cancer patients aged 60 years or older (132 women, with a mean age of 68.3 +/- 6.6 years; 72 men, with a mean age of 67.0 +/- 5.3 years). RESULTS: Of the 204 patients, 142 had well-differentiated thyroid carcinomas (96 papillary thyroid carcinomas, 43 follicular carcinomas, three Hürthle cell carcinomas) and three medullary carcinomas. Sixty-nine (33.8%) of the 204 patients died after treatment. Of these, three patients died of causes not related to thyroid cancer. For well-differentiated thyroid carcinomas, male gender, follicular carcinoma, and a larger tumour size indicated a poor prognosis. Of the 59 non-well-differentiated thyroid carcinomas, 39 were anaplastic thyroid carcinomas, nine metastatic cancers of the thyroid, seven lymphomas, and four squamous cell carcinomas. After treatment, 40 (67.8%) of the 59 patients died. In multivariant analysis of the differences in clinical parameters between aging and younger thyroid cancer patients, the current status, tumour size, follow-up period, sex, and stage at diagnosis were independent factors. From this data the delayed diagnosis of aging patients with thyroid cancer was of note when compared with younger patients. CONCLUSION: Thyroid cancer in older patients is not a benign clinical disorder. Early diagnosis and urgent aggressive treatment are recommended courses of action for this type of cancer, especially for non-well-differentiated thyroid cancers.

Adenocarcinoma, Follicular↗
PubMed2000

Fluence-to-dose conversion coefficients from monoenergetic neutrons below 20 MeV based on the VIP-man anatomical model.

A new set of fluence-to-absorbed dose and fluence-to-effective dose conversion coefficients have been calculated for neutrons below 20 MeV using a whole-body anatomical model, VIP-Man, developed from the high-resolution transverse colour photographic images of the National Library of Medicine's Visible Human Project. Organ dose calculations were performed using the Monte Carlo code MCNP for 20 monoenergetic neutron beams between 1 x 10(-9) MeV and 20 MeV under six different irradiation geometries: anterior-posterior, posterior-anterior, right lateral, left lateral, rotational and isotropic. The absorbed dose for 24 major organs and effective dose results based on the realistic VIP-Man are presented and compared with those based on the simplified MIRD-based phantoms reported in the literature. Effective doses from VIP-Man are not significantly different from earlier results for neutrons in the energy range studied. There are, however, remarkable deviations in organ doses due to the anatomical differences between the image-based and the earlier mathematical models.

Algorithms↗
PubMed2000

VIP-Man: an image-based whole-body adult male model constructed from color photographs of the Visible Human Project for multi-particle Monte Carlo calculations.

Human anatomical models have been indispensable to radiation protection dosimetry using Monte Carlo calculations. Existing MIRD-based mathematical models are easy to compute and standardize, but they are simplified and crude compared to human anatomy. This article describes the development of an image-based whole-body model, called VIP-Man, using transversal color photographic images obtained from the National Library of Medicine's Visible Human Project for Monte Carlo organ dose calculations involving photons, electron, neutrons, and protons. As the first of a series of papers on dose calculations based on VIP-Man, this article provides detailed information about how to construct an image-based model, as well as how to adopt it into well-tested Monte Carlo codes, EGS4, MCNP4B, and MCNPX.

Adult↗
PubMed2000

Female sex hormones modulate the function of LPS-treated macrophages.

PROBLEM: To study the effects of estradiol (E2) or progesterone on macrophage function in the presence of lipopolysaccharide (LPS). METHOD OF STUDY: Male rat peritoneal macrophages were treated in vitro with 0.1 microg/mL of LPS and E2 or progesterone. RESULTS: At 10(-2) ng/mL, E2 significantly (P < 0.05; n = 6) enhanced tumor necrosis factor (TNF) release by LPS-treated macrophages. TNF release was significantly (P < 0.05; n = 6) inhibited by 10(2) ng/mL or 10(3) ng/mL of E2 and by progesterone at less than 10(-3) ng/mL or greater than 10(-1) ng/mL. E2 (10(-4) and 10 ng/mL) and progesterone (10(-6)-10(-4) ng/mL and 10(2) ng/mL) each significantly (P < 0.05, n = 8) enhanced H2O2 release by LPS-treated macrophages. E2 ( < 10(-2) and > 10 ng/mL) and progesterone (10(-7)-10(4) ng/mL) each significantly inhibited (P< 0.05; n = 6) NO2- release by LPS-treated macrophages. CONCLUSIONS: Exposure to LPS tended to diminish the effects of E2 and to enhance the effects of progesterone on the parameters determined here. Such LPS-associated alterations in the dose-response profile of macrophages to female sex hormones may contribute to gender-related differences in the immune response under normal and pathological conditions.

Animals↗
PubMed2000

Preeclamptic pregnancy is associated with increased sympathetic and decreased parasympathetic control of HR.

Previous work from our laboratory using heart rate variability (HRV) has demonstrated that women before menopause have a more dominant parasympathetic and less effective sympathetic regulations of heart rate compared with men. Because it is still not clear whether normal or preeclamptic pregnancy coincides with alternations in the autonomic functions, we evaluated the changes of HRV in 17 nonpregnant, 17 normotensive pregnant, and 11 preeclamptic women who were clinically diagnosed without history of diabetic neuropathy, cardiac arrhythmia, and other cardiovascular diseases. Frequency-domain analysis of short-term, stationary R-R intervals was performed to evaluate the total variance, low-frequency power (LF; 0.04-0.15 Hz), high-frequency power (HF; 0.15-0.40 Hz), ratio of LF to HF (LF/HF), and LF in normalized units (LF%). Natural logarithm transformation was applied to variance, LF, HF, and LF/HF for the adjustment of the skewness of distribution. We found that the normal pregnant group had a lower R-R value and HF but had a higher LF/HF and LF% compared with the nonpregnant group. The preeclamptic group had lower HF but higher LF/HF compared with either the normal pregnant or nonpregnant group. Our results suggest that normal pregnancy is associated with a facilitation of sympathetic regulation and an attenuation of parasympathetic influence of heart rate, and such alterations are enhanced in preeclamptic pregnancy.

Adult↗
PubMed2000

Trends in the clinical characteristics of patients with papillary thyroid carcinoma in Taiwan.

The incidence of thyroid cancer is influenced by many factors including socioeconomic status. As economic conditions have improved in Taiwan, the increased frequency of medical examinations in the general population has led to earlier diagnosis of this indolent malignancy. The purpose of this retrospective study was to compare the clinical characteristics of cases of papillary thyroid cancer diagnosed over a 6-year period from 1993 to 1998 with those patients diagnosed from 1977 to 1992 at a single medical center. Of the 1,485 pathologically verified cases of thyroid cancer from 1977 to 1998, 1, 093 had papillary thyroid carcinoma. The mean age of these patients was 40.4 +/- 14.6 years. In order to identify trends in the characteristics of patients with thyroid cancer, patients were divided into those diagnosed before and those diagnosed after 1993. Patients diagnosed in these two time periods were also categorized into disease-free or non-disease-free groups depending on their status at the end of 1998. Actuarial survival rates were calculated using the Kaplan-Meier method. Multivariate analysis was performed to assess the independent effect of these variables using the Cox model. By December 1998, 61 (5.6%) of the 1,093 patients with papillary thyroid carcinoma had died. Among them, only 35 (3.2%) patients had died of thyroid cancer. The 5-year Greenwood survival probabilities for the groups diagnosed before and after 1993 were 0. 9412 and 0.9817, respectively. The patients diagnosed after 1993 received more aggressive surgical procedures, had smaller tumor size, lower postoperative thyroglobulin levels, less advanced clinical stage at the time of diagnosis, showed more disease-free survival, and a lower mortality rate. In conclusion, the results of this study show that patients with a diagnosis of papillary thyroid cancer after 1993 had a smaller tumor size and a better prognosis than those diagnosed before 1993. This finding emphasizes the importance of early detection in thyroid cancer.

Adult↗
PubMed2000

Immunophenotypic and genotypic characteristics of chronic myelogenous leukemia in blast crisis.

BACKGROUND: Chronic myelogenous leukemia (CML) may transform into blast crisis (BC) if not properly treated. Among patients with transformation, 20% to 30% will develop BC with lymphoid-associated antigens (Ly-BC), and the remaining cases with myeloid-associated antigens (My-BC) or with both (Mix-BC). In this study, we investigated the lineage of blast cells in CML-BC using immunophenotypic and genetic analyses and analyzed the prognostic significance of genotypic change in CML-BC. METHODS: Twenty-one patients with CML-BC diagnosed at the Taipei Veterans General Hospital from 1982 to 1992 were included. Immunophenotyping was done by using the avidin-biotin immunoperoxidase technique. Genetic analyses were carried out by using Southern Blot hybridization. The prognostic influence of genotypic change was analyzed. RESULTS: Thirteen patients (61.9%) expressed myeloid-associated antigens, one patient (4.8%) expressed megakaryoblast-associated antigens, four patients (19%) expressed B lymphoid-associated antigens and three patients (14.3%) expressed both myeloid and B lymphoid antigens. Clonal rearrangement of the immunoglobulin heavy chain (IgH) gene was found in six cases. Among them, four expressed B lymphoid markers only and two expressed both myeloid and B lymphoid markers. Patients with clonal IgH gene rearrangement tended to have a better response to chemotherapy (50% vs 8.3%, p = 0.08) and significantly longer survival (median survival, 5 months vs 3 months, p < 0.05) than did those with a germline configuration. CONCLUSIONS: Clonal rearrangement of the IgH gene was found mostly in cases of Ly-BC and Mix-BC. We found that CML-BC with clonal rearrangement of the IgH gene had a more favorable prognosis than in cases with a germline configuration.

Adolescent↗
PubMed1999

Somatostatin and octreotide modulate the function of Kupffer cells in liver cirrhosis.

In our previous studies we have shown that somatostatin and octreotide modulate the function of peritoneal macrophages and Kupffer cells in noncirrhotic livers. However, the effects of somatostatin on the Kupffer cells in cirrhotic livers are not known. In the present study, Kupffer cells, obtained from male rats with carbon tetrachloride-induced cirrhotic livers, were treated in vitro with somatostatin or octreotide and their effects on the release of nitric oxide, tumor necrosis factor-alpha (TNF-alpha) and peroxide (H2O2) determined. At concentrations of 10(-13) or 10(-10) to 10(-6) M of somatostatin or 10(-12) to 10(-10) M, or 10(-6) M of octreotide, the amount of nitric oxide released by Kupffer cells was significantly suppressed relative to that of untreated cells. Kupffer cells treated with less than 10(-12) M or greater than 10(-12) M of somatostatin or octreotide released less TNF-alpha compared to the untreated controls. In addition, zymosan-induced H2O2 release by Kupffer cells treated with 10(-9) to 10(-7) M somatostatin or with 10(-15) to 10(-13) M and 10(-9) to 10(-7) M of octreotide was greater than that of the untreated controls. These findings demonstrate that somatostatin and octreotide modulate the release of nitric oxide, TNF-alpha and H2O2 by Kupffer cells in cirrhotic livers depending on the concentrations of hormones used.

Animals↗
PubMed1999

Thyroid cancer with concurrent hyperthyroidism.

OBJECTIVE: To study the clinical manifestation, outcome, and factors predicting metastases in patients with thyroid cancer and concurrent hyperthyroidism. DESIGN: Retrospective study of 37 thyrotoxic patients with differentiated carcinomas of the thyroid who were operated on between 1979 and 1995. The follow-up period ranged from 562 days to 14 years 9 months (mean +/- SE, 2093+/-201 days). SETTING: University hospital with an annual performance rate of about 700 thyroid operations. PATIENTS: Thyroidectomy was performed in 37 patients (31 women and 6 men), including 33 papillary carcinomas and 4 follicular carcinomas. The mean +/- SE age of the patients was 38.6+/-2.2 years. RESULTS: The mean +/- SE diameter of tumors was 13.2+/-0.9 mm (range, 2-67 mm). The tumor size in 25 patients (68%) was 10 mm or smaller. Subtotal thyroidectomy (21 patients), total thyroidectomy (8 patients), near-total thyroidectomy (4 patients), and completion thyroidectomy (4 patients) were performed. Twenty-eight patients underwent postoperative sodium iodide I 131 (131I) ablation for thyroid remnant. There was 1 local recurrence, 3 metastases to regional neck lymph nodes, and 3 distant metastases. A patient with follicular carcinoma died of metastases at 3 years 4 months after thyroidectomy. Age, sex, duration of thyrotoxic symptoms, tumor size, histopathological findings, type of goiter, extent of surgery, 131I ablation, and 6-week postoperative serum concentrations of thyroglobulin or thyrotropin were not significant factors in predicting metastases. Serum levels of triiodothyronine and thyroxine before antithyroid treatment in the patients with metastases were significantly higher than in those without metastases. CONCLUSION: The majority of patients with thyroid cancer and concurrent hyperthyroidism have small carcinomas.

Adult↗
PubMed1999

Metaplastic carcinomas of the breast.

BACKGROUND AND OBJECTIVES: Metaplastic carcinomas of the breast are rare neoplasms. The purpose of the present study is to better characterize the clinical course, treatment, and prognostic factors of metaplastic breast carcinomas. METHODS: Data of 14 patients with metaplastic breast carcinoma were retrospectively reviewed. The follow-up period ranged from 2 months to 10 years, 10 months (median 4.3 years). RESULTS: The patients' ages ranged from 38 to 66 years (median 50.5 years). The tumors were 2.5 to 18 cm (median 4.8 cm) in size. Seven patients had axillary nodal metastases at the time of diagnosis. Estrogen and progesterone receptors were positive in only one tumor. Twelve patients underwent modified radical mastectomy and two patients underwent incisional biopsy. Adjuvant chemotherapy was administered to six patients, and radiotherapy to two patients after mastectomy. Two patients received preoperative chemotherapy. Seven patients were living without evidence of disease at a median of 7.3 years after surgery. A patient died of ovarian carcinoma without recurrence or metastasis of breast cancer. Metastases occurred in five patients at 4 to 16 months (median 8 months) after initial treatment. Duration of symptoms, TNM stage, tumor size, and axillary nodal status were significant prognostic factors of survival. CONCLUSIONS: The patients with metaplastic breast carcinomas may have a favorable prognosis.

Adult↗
PubMed1999

Intrahepatic cholangiocarcinoma in Taiwan.

We report our experience of the surgical treatment of intrahepatic cholangiocarcinoma (ICC) in Taiwanese patients. A total of 162 patients with histologically proven ICC were treated of whom 106 (65. 4%) had associated hepatolithiasis. Patients with hepatolithiasis were in earlier stages than those without hepatolithiasis. Two-thirds of the patients with hepatolithiasis presented with acute cholangitis, and two-thirds of those without hepatolithiasis presented with hepatomegaly. The rate of hepatic resection was 29.6% (48 of 162), and these rates were 31.1% and 26.8% for the patients with and without hepatolithiasis, respectively. Ninety-three percent of the patients with hepatolithiasis underwent common bile duct exploration, compared with 18% of those without hepatolithiasis. The surgical mortality rates were 3.7% (6/162), for all patients, and 3. 8% and 3.6% for patients with and without hepatolithiasis, respectively. The morbidity rate was much higher in the patients with hepatolithiasis (37.7% vs 16.1%). The 1-, 3-, and 5-year survival rates were 35.5%, 20.5%, and 16.5% in the patients with hepatolithiasis and 27.2%, 8.8%, and 7.8% in those without hepatolithiasis. Concomitant hepatolithiasis prevented precise diagnosis preoperatively and precipitated biliary sepsis, which affected resectability and increased postoperative morbidity. Hepatolithiasis per se did not influence long-term survival.

Adult↗
PubMed1999

Carcinogenesis in the biliary system associated with APDJ.

Anomalous pancreaticobiliary ductal junction (APDJ) is a rare congenital anomaly which is considered to be an etiological factor in the development of carcinoma of the biliary tract. It is generally accepted that pancreatic juice reflux into the biliary tract due to APDJ is one of the etiologies of biliary tract cancers. Refluxing pancreatic juice results in changes of bile and induces chronic inflammation and increased cellular proliferation, leading to epithelial hyperplasia, metaplasia, and carcinoma of the biliary tract. K-ras mutations are more prevalent in the carcinomas of biliary tract associated with APDJ compared with those without APDJ. There is no difference in the overexpression of p53 between biliary tract carcinomas associated with APDJ and those unassociated with APDJ. Further studies are needed to evaluate the role of cytokines and growth factors in carcinogenesis of the biliary system associated with APDJ.

Adenocarcinoma↗
PubMed1999

Laparoscopic loop ligatures for bladder repair during laparoscopic surgery.

In this paper, we report a case where a bladder perforation occurred during a laparoscopically assisted vaginal hysterectomy and was repaired by laparoscopic loop ligatures. This is the first case report of using the laparoscopic loop ligatures to close the bladder perforations. The loop ligature is an easy and quick procedure, which can be performed by most surgeons who take the time to learn the endoscopic suturing techniques.

Female↗
PubMed1999

Color Doppler ultrasound in benign and malignant breast tumors.

To study the flow indices of color Doppler ultrasound in the differentiation of malignant and benign breast tumors, data of 1124 female patients with breast lesions were analyzed. Of 1124 breast lesions, 590 (525%) were benign and 534 (47.5%) were malignant. Color Doppler scanning detected vascularity in 505 (85.6%) of benign lesions and 509 (95.3%) of malignant tumors. The tumors without detectable vascularization (1.9 +/- 0.1 cm) were significantly (p < 0.0001) smaller than the tumors with vascularization (2.7 +/- 0.1 cm). The age of the patients with malignant tumors was older than that of the patients with benign lesions. The size of malignant tumors was significantly larger than that of benign lesions. Significantly higher values of vessel number, resistance index (RI), pulsatility index (PI), and systolic peak flow velocity (Vmax) were found in carcinomas but the striking overlap of the values did not allow defining cutoff values which allow an accurate differentiation. Vmax did not correlate with the size of tumors. When tumors were grouped as T1 (2 cm or less), T2 (>2 cm, but not >5 cm), and T3 (>5 cm), the results were similar to those of all breast tumors. In conclusion, number of vessels, RI, PI, and Vmax do not provide accurate differentiation of benign and malignant tumors. However, average values of these flow indices of malignant tumors were significantly larger than those of benign lesions. Tumors with larger values of vessel number, RI, PI or Vmax require further studies to disclose the possibility of malignant tumors.

Adolescent↗