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Biomedical subjects

K T Chen

Publications and source records attributed to K T Chen.

At least 19 recordsLinked to original sources

Mycobacterial spindle cell pseudotumor of lymph nodes.

Two cases of spindle cell pseudotumor in the lymph nodes of patients with acquired immunodeficiency syndrome caused by mycobacterial infection are reported and the literature reviewed. The lesions mimicked neoplasms because they were composed predominantly of spindle cells arranged in a storiform pattern. Most of the spindle cells were phagocytic cells that contained large amounts of mycobacteria. It is important for the pathologist to recognize the lesion so that a prompt tissue diagnosis can be provided because specific therapy is available.

Acquired Immunodeficiency Syndrome

Open tip rhinoplasty.

An open tip rhinoplasty was used to correct moderate to severe secondary cleft lip nasal deformities in 122 patients from January 1986 to January 1988. The results of the surgery on 92 patients who were followed for 1 year or more were evaluated. When the surgery was performed after the age of 3 years, 60% of the patients had a satisfactory result. The pathology of the deformity included 32% with deficiencies of the nasal lining, 35% needed framework support such as a columellar strut, and 45% required correction of columellar deficiencies. Patients using a postoperative nasal stent had a 71% satisfactory result compared with a 37% satisfactory result when the stent was not used. The pathology and techniques to correct the nasal deformity are described.

Child, Preschool

Prevalence of goiters in school children residing in villages where underground water is used.

A representative of Fuder village in Taichung County complained that many residents had a goiter problem, which he felt might be related to pollution from the nearby Youshi industrial area. The purpose of this study was to determine whether school children in the Fuder area have a high prevalence of goiters. We chose children of the Schichi elementary school in the Fuder area as the study population, and children of the Goumei elementary school, far from the Youshi industrial area, as controls. Both groups were from a similar geographic location (near the sea), had similar socioeconomic status, and both drank underground water. Thyroid enlargement was examined by palpation as recommended by the World Health Organization. Thyroid antibodies and hormones were determined in school children with a goiter and age-sex-matched normal control children using the particle agglutination method and radioimmunoassay, respectively. In total, 1,692 school children were examined, including 875 males and 817 females. Of these, 126 school children (7.4%) had a goiter of Grade I or above. The prevalence of goiters in Shichi and Goumei were 8.8% (59/671) and 6.6% (67/1,021), respectively. There was no significant difference between these two areas. We compared the prevalence of goiters in these two schools where underground water is drunk with another previous study in Peimen and Putai where tap water is used. There was a statistically significant difference (7.4% vs 2.6%, p < 0.0001). This suggests that the higher prevalence rate of goiters in Shichi and Goumei is related to the drinking of underground water. We recommend that the use of tap water and continued salt iodization is the way to prevent endemic goiter in these areas. A further comprehensive study is needed to determine the nature of the goitrogen in the underground drinking water of the Fuder area.

Child

[Risk factors of lung cancer].

The relationship between various risk factors and lung cancer was evaluated in a case-control study. One hundred and forty-one cancer patients newly cytologically or pathologically diagnosed from May 1990 to July 1991 at Tri-Service General Hospital (TSGH) were recruited as cases. Two control groups were also studied: 282 hospital controls two-to-one matched with cases on sex, age, hospital of admission and insurance status were selected from the TSGH Ophthalmologic Department, and 282 neighborhood controls two-to-one matched on sex, age, and residence were randomly selected from eligible neighbors. A comparison of interview data between cases and hospital controls based on multiple conditional logistic regression revealed that cigarette smoking, keeping doves as pet, occupational exposure to cotton dust and working as a cook were risk factors for lung cancer. An inverse association between incense burning and lung cancer was noted. The comparison between cases and neighborhood controls showed lung cancer was significantly associated with cigarette smoking, keeping doves, prior chronic bronchitis, occupational exposure to cotton dust, asbestos and radiation, low frequency of burning incense, and low intake of vitamin A derived from vegetables and fruits. There was no association between lung cancer and working as a cook when cases were compared with neighborhood controls.

Adult

Hyperamylasemia following cardiopulmonary bypass.

In order to study the occurrence of postbypass hyperamylasemia, 75 patients undergoing cardiopulmonary bypass (CPB) were studied from March 1989 to January 1990. There were 49 males and 26 females. Among them, 27 had congenital heart disease, 30 had valvular disease, and 18 had coronary artery disease. There were 27 patients with at least one elevated serum amylase sample after operation. Thus, the overall incidence of hyperamylasemia was 36%. As compared with the preoperative data (1.3%), there was a statistically significant difference in the occurrence of hyperamylasemia (p less than 0.05). Three patients had overt clinical pancreatitis postoperatively. There was no positive correlation between the serum amylase level and the occurrence of pancreatitis (p greater than 0.05). Forty-two cases had a significant elevation of the amylase creatinine clearance ratio (ACCR) after CPB. However, there was no significant difference between the groups with pulsatile and nonpulsatile CPB (p greater than 0.05). Three patients (4%) died in our series. The causes of death were heart failure in two and fulminant pancreatitis associated with low cardiac output in one. Although our experience in dealing with pancreatitis improved survival, mortality was still high (33.3%) in our series. Nevertheless, there was no apparent correlation between mortality and postbypass hyperamylasemia (p greater than 0.05). Logistic regression analysis was used to analyze the risk factors of the occurrence of hyperamylasemia, and the analysis revealed that patients with coronary artery disease were susceptible to postbypass hyperamylasemia. Our studies indicate that the use of total serum amylase or ACCR to monitor for the occurrence of pancreatitis in postbypass patients is inadequate.(ABSTRACT TRUNCATED AT 250 WORDS)

Amylases

Manganese superoxide dismutase is induced by IFN-gamma in multiple cell types. Synergistic induction by IFN-gamma and tumor necrosis factor or IL-1.

We have previously characterized more than 20 proteins induced by the immunoregulatory lymphokine IFN-gamma in human fibroblasts by their m.w. and isoelectric points determined in two-dimensional gels. Some of these proteins are induced uniquely by IFN-gamma, whereas others are also induced by IFN-alpha, TNF, or IL-1. Recent technologic advances have allowed us to begin to rapidly identify proteins induced by IFN-gamma and other cytokines by sequencing the induced proteins from blots of preparative two-dimensional gels of total cell lysates. In this study, we show that the approximately 21 kDa, isoelectric point greater than 7 protein induced by IFN-gamma is manganese superoxide dismutase (Mn-SOD), a mitochondrial protective enzyme encoded by a nuclear gene. Mn-SOD is induced by IFN-gamma and also by TNF in all four human cell lines examined: HS153 fibroblasts, ACHN renal carcinoma, A549 lung carcinoma, and A375 melanoma. Induction of Mn-SOD mRNA is a primary, rapid, and dose-dependent response to IFN-gamma. In ACHN renal carcinoma cells, Mn-SOD mRNA and protein are induced synergistically by IFN-gamma in combination with either TNF or IL-1, and the induced protein is enzymatically active. IFN-gamma and TNF together induce Mn-SOD mRNA by more than 100-fold relative to its level in untreated ACHN cells. The induction of Mn-SOD by IFN-gamma and its synergistic induction by IFN-gamma in combination with TNF and IL-1 should protect healthy cells from the toxicity of O2- during an immune response, and may provide a mechanism for selective killing of infected cells.

Amino Acid Sequence

Fine-needle aspiration cytology of papillary Hürthle-cell tumors of thyroid: a report of three cases.

Papillary Hürthle-cell tumors of the thyroid are composed of oxyphilic cells with a prominent papillary component. Their biologic behavior appears to be comparable with that of conventional papillary thyroid carcinomas. The literature on the fine-needle aspiration cytology of these tumors is scanty. The cytologic findings of three such cases are reported here. The findings suggest that most papillary Hürthle-cell tumors cannot be differentiated from other types of Hürthle-cell tumors cytologically.

Biopsy, Needle

Megakaryocytes in fine-needle aspiration biopsy of breast.

An unusual case in which megakaryocytes were found in fine needle aspirate of a breast lesion is reported. The megakaryocytes in the smears were initially mistaken to be malignant cells. However, the cell block sections available later showed normal bone marrow particles, indicating that an inadvertent puncture of a rib was the reason for the presence of megakaryocytes in the smears.

Aged

An analysis of traffic injuries in Taiwan in relation to alcohol use and economic loss.

Breath alcohol analysis of 449 patients with motor vehicle injuries attending the emergency department of a Taiwan urban general hospital during a 10-week period showed that 19.2 per cent had breath alcohol concentration (BAC greater than 0.002 per cent and 8.5 per cent greater than or equal to 0.05 per cent). Injured males were more likely to have BAC greater than or equal to 0.05 per cent than women (11 per cent vs 0 per cent). Injuries resulting from alcohol-associated collisions were about 6.7 times more likely to occur between 1800 and 0600 than at other time periods. A telephone survey after hospital discharge showed that the risk factors of alcohol use, speed at time of collision and type and site of collision were significantly associated with degree of economic loss resulting from the accidents. Logistic regression analysis showed that the odds of high economic loss associated with BAC greater than 0.002 per cent were three times greater than for persons in whom no alcohol was detected. This is the first study in Taiwan to use breath alcohol analysis in assessing the effect of alcohol consumption on motor vehicle injuries. The results show that alcohol use is an important cause of motor vehicle injuries. Preventive measures such as strict legal control of drunk driving and limitation of the hours that drinking places can stay open at night are recommended to reduce the damage caused by this severe public health problem.

Accidents, Traffic

Appendiceal carcinoma masquerading as primary bladder carcinoma.

We report 2 cases of appendiceal adenocarcinoma invading the bladder. Both tumors masqueraded as primary bladder carcinomas. Cystoscopic biopsies obtained adenocarcinomatous tissue and the secondary nature of the bladder lesion became apparent at laparotomy in both cases. One patient was treated with surgical resection of the appendix, the adjacent cecal wall and the bladder wall, and postoperative irradiation. She was well 10 years later. The other patient was treated with right colectomy and segmental bladder resection. She died of diffuse peritoneal recurrence 6 years later.

Adenocarcinoma, Mucinous

Angiosarcoma in postsurgical lymphedema. An unusual occurrence in a man.

A 63-year-old man underwent partial left axillary node dissection for metastatic melanoma of unknown primary. Lymphedema of his left upper extremity developed after surgery. Eight years later, extensive cutaneous angiosarcoma developed in the edematous limb. The occurrence of cutaneous angiosarcoma in postsurgical lymphedema is extremely rare in men; to our knowledge, our case is the fifth such case thus far reported.

Arm

Factors affecting local or regional recurrence in breast cancer.

Between 1975 and 1989, 535 patients with infiltrating ductal carcinoma of the breast in various clinical stages were treated by modified radical mastectomy and axillary node clearance, followed by chemotherapy, endocrine therapy or radiotherapy. Median follow-up was 3 years (5 months to 15 years). Fifty-eight local or regional recurrences occurred. The 5-year and 10-year actuarial risks of breast recurrences were 14% +/- 2% and 23% +/- 4%, respectively. Using multivariate analysis with the Cox regression model, the most important multivariate-adjusted independent contributing factors to local or regional breast recurrences were age less than or equal to 40 (p less than 10(-4), relative risk = 2.94), positive lymph nodes greater than 3 (p less than 10(-3), relative risk = 2.57), and multicentricity (p = 0.044, relative risk = 2.73). The overall 5-year survival rate of recurrent patients was 64 +/- 7%, and was significantly worse when breast recurrence occurred in the first 18 months after operation. The multivariate-adjusted relative risk of death for early recurrence was 4.35 (p = 0.04). The unadjusted 5-year survival rate for early recurrence was 58% +/- 1%, and 85% +/- 8% for late recurrence. This study confirms the relationship between young age and low breast control rates. It emphasizes the adverse prognosis of early breast recurrences as compared to the relatively favorable outcome of late recurrences.

Adult

Studies on the photochemical and photocytotoxic properties of the new PDT photosensitizer aluminum sulfonated phthalocyanine.

The properties of photosensitization of sulfonated aluminum phthalocyanine (ALSPC), a new photosensitizer of potential use in cancer photodynamic therapy (PDT) was studied on both the molecular and cellular levels. The mechanism of ALSPC photosensitization on the molecular level was investigated by testing its efficiency of singlet oxygen (1O2) production, using the method of tryptophan degradation and that of ESR spectroscopy and observing the enhancing effect of D2O and the quenching effect of NaN3. Results of all these experiments confirmed the important role of the Type II or 1O2 mechanism in ALSPC photosensitization. In our in-vitro experiments, ALSPC's incorporation into cells and its photocytotoxic effect were investigated on a human liver cancer cell line. The cell incorporation was illustrated by the laser-excited fluorescence spectra emitted both from cell homogenate and cell monolayers incubated with ALSPC aqueous solution. The position of fluorescence peak observed, implied that ALSPC exists in the cells mainly as monomers. The efficiency of cell killing of ALSPC photosensitization was estimated by counting surviving cells with the method of trypan blue staining and by the method of radioisotope labelling. Experiments using the latter method also showed DNA damage caused by ALSPC photosensitization.

Cell Death