Search PubMed⌕ Search

Biomedical subjects

C C Chen

Publications and source records attributed to C C Chen.

At least 505 records · Page 28Linked to original sources
PubMed1992

The value of transesophageal echocardiography in the diagnosis of cardiac metastasis.

To assess the diagnostic value of transesophageal two-dimensional echocardiography (TEE) as compared with transthoracic echocardiography (TTE), TTE and TEE were performed in eight consecutive patients (age range from 20 to 76 years, six male and two female) with clinical evidence of malignant tumors arising from the liver (n = 1), lung (n = 3), larynx (n = 1), osteogenic sarcoma (n = 1), lymphoma (n = 1), and yolk sac tumor in the anterior mediastinum (n = 1). In one case, the gastroscope could not be inserted because of tumor compression of the esophagus. Transesophageal echocardiography provided superior imaging in the detection of intracavitary metastatic lesions. In the case of right ventricular outflow tract tumor and greater vessel involvement, TTE may provide more imaging than TEE due to a blind area in this region by the transesophageal approach. In conclusion, TEE is complementary to TTE in the diagnosis of metastatic cardiac tumor.

Adult↗
PubMed1992

Restriction endonuclease analysis of chloroplast DNA from streptomycin-resistant mutants of Nicotiana plumbaginifolia.

Chloroplast DNA isolated from wild-type Nicotiana plumbaginifolia and 12 maternally inherited streptomycin-resistant mutants was digested with various restriction enzymes and the resultant patterns were compared. No gross structural alterations of the chloroplast genome were detected in any mutants; however, variant patterns owing to the gain or loss of a restriction site were found in three mutants, SR1007, SR1019, and SR1022. The variant patterns in SR1019 and SR1022 are identical and are the results of mutation in the psbG gene coding for a chloroplast membrane protein G, and that in SR1007 is due to mutation in the 16S rRNA gene. Inheritance of the variant patterns in mutants SR1007 and SR1019 was studied. The results showed that the variant patterns and streptomycin resistance were co-transmitted in reciprocal crosses.

Base Sequence↗
PubMed1992

Effect of the duration of streptozotocin-induced diabetes on turnover of central biogenic amines in mice.

The relationship between central catecholaminergic and serotonergic neurons and the development of streptozotocin-induced diabetic mice was examined over periods of 3, 14, 50 and 100 days. The accumulation of 3,4-dihydroxyphenylalanine (DOPA) and 5-hydroxytryptophan (5-HTP) were measured after central decarboxylase activity was inhibited by m-hydroxybenzylhydrazine (NSD-1015). Results indicated that DOPA accumulation in the hypothalamus was not altered during the entire time course of the experiment. On the other hand, DOPA accumulation in the striatum was decreased in 50- and 100-day diabetic mice. The DOPA levels in the pons medulla were not increased until the mice had been diabetic for 100 days. The accumulation of 5-HTP was decreased in the hypothalamus of 14-day diabetic mice and was also present at 50 and 100 days, that in the striatum and pons medulla was not decreased until the mice had been diabetic for 50 days and persisted to 100 days in the striatum. These data showed that both DOPA and 5-HTP accumulation in the striatum and pons medulla were changed only in long-term diabetic mice and suggested that changes in catecholamine and serotonin turn-over rates are not generalized, but restricted only to some particular brain regions and time courses.

5-Hydroxytryptophan↗
PubMed1992

A typology of alcoholism in Taiwan aborigines: a study on evolving process of community cases.

Thirty-one habitual drinkers with a personal, familial, social complication were screened from a Taiwan aborigine community. Each was given an in-depth descriptive semistructured interview. The interview, recorded with audiotape, contained 4 aspects: (1) personal developmental history; (2) family structure and interaction; (3) developmental process and current state of drinking behavior, and (4) attitude toward drinking behavior. Based on the evolving process and current state of drinking behavior, three process patterns of alcoholism were defined: (1) social developmental type (67.7%); (2) deviant behavioral type (9.7%), and (3) special constitutional type (22.6%).

Adult↗
PubMed1992

Localization of HPV-16 DNA sequence in CaSki cells by electron microscopic hybridocytochemistry.

We investigated the HPV-16 DNA sequence in the CaSki cervical carcinoma cell line by electron microscopic hybridocytochemistry using biotinylated HPV-16/18 probes. At the light microscopic level, reaction product of hybridized HPV-16 DNA sequence was not seen in the cytoplasm but appeared as spots or rods randomly distributed in the nuclei. By electron microscopy, reaction product was seen aggregated in several regions in the nuclei. Most of the stained areas did not reveal particular architecture but showed part of the chromatin structure. In other nuclei, reaction product was observed to be associated with strings of loop-like structure, and some stained loops were seen to be connected directly to the nuclear filamentous chromatin structure. The skeletonized images of hybridized HPV-16 DNA in the nuclei were illustrated by computerized image analysis. In conclusion, we have demonstrated the HPV-16 DNA sequence in the nuclei of CaSki cells by electron microscopy. The identification of stained areas localized only in the chromatin suggests an integrated form of HPV-16 DNA sequence in the cells. This method could be used to identify an integrated or episomal form of viral DNA in the virus-containing cells.

Biotin↗
PubMed1992

Radon concentration in two largest cities in semitropical Taiwan.

Grab sampling either using the active charcoal method in combination with an ionization chamber or using a working level monitor was performed for the measurement of radon concentration in Taiwan's two largest cities Taipei and Kaohsiung. Long-term monitoring of radon concentration in dwellings and business buildings was also carried out with cellulose nitrate films as the alpha detectors. The average indoor radon concentration in these two cities is 17 +/- 6 Bq m-3. The outdoor radon concentration is about one-half of that on average. As assessed according to the model of UNSCEAR 1988, the induced effective dose equivalent is 0.67 mSv y-1. Radon concentration in coal mines showed an average of 88.5 +/- 9.5 Bq m-3.

Air Pollutants, Radioactive↗
PubMed1992

Experience with treatment of gastroschisis and omphalocele.

From 1982 to 1990, 31 neonates with omphalocele and 54 with gastroschisis were treated at Mackay Memorial Hospital. The overall survival rate for omphalocele was 71%, while it was 85% for gastroschisis. The rate of primary fascial closure for omphalocele (85%) and gastroschisis (87%) was similar. The mortality from omphalocele was almost exclusively due to the presence of serious associated congenital anomalies. Two cases of Cantrell's pentalogy and two of cloacal exstrophy were found. The incidence of major malformation with gastroschisis was 6%. Sepsis, inadequate perioperative resuscitation and prolonged gastrointestinal dysfunction were the major causes of death in gastroschisis. Among survivors, the hospital stay was significantly longer in the silon pouch group than in the primary fascial closure group (71.5 vs 31.3 days for gastroschisis, 41 vs 14 days for omphalocele). Advances in surgical technique, neonatal intensive care and ventilatory support have made primary fascial closure a superior approach without jeopardizing the babies' chance for survival. An improved survival rate and increased primary closure rate are the main features in the treatment of abdominal wall defects in the last decade.

Abdominal Muscles↗
PubMed1992

Congenital short bowel syndrome: report of a case treated with home central parenteral nutrition.

Congenital short bowel is a rare anomaly. Among the 21 cases reviewed in the literature, only four (19%) survived beyond infancy. We present a female infant with short small bowel, malrotation and floating colon, who was successfully treated with home central parenteral nutrition. Improved long-term survival in this group of patients is expected with prolonged parenteral nutritional support.

Female↗
PubMed1992

[Peutz-Jeghers syndrome: report of two cases and review of the literature].

Two cases brothers of Peutz-Jeghers syndrome are reported, in which the gastrointestinal polyps were resected by laparotomy and enterotomy. One of the polyps was in the cecum and was found to have atypia cellular change, though no malignancy was found in the others, which were thought to be hamartomas. The hamartomatous polyps were initially thought to have little potential for malignancy, and the disease was believed to have a relatively benign course. However, reports in the literature have associated this syndrome with various kinds of malignancies, and the overall risk of cancer in this population is regarded as higher than normal. The analysis of our cases and a review of the literatures are presented for clarification of the predisposition of the development of malignancies in these patients.

Adolescent↗
PubMed1992

[Analysis of treatment and results of periapical surgery].

The purpose of this investigation was to study the treatment results following periapical surgery at Taipei Chang Gung Memorial Hospital. From August 1984 to November 1990, 101 periapical surgery treatments were performed on 82 patients. A total of 40 patients with 47 teeth were reexamined more than one year after they had received periapical surgery. The observation period varied from 1 to 6 years. According to radiographic and clinical criteria, the treatment results were considered successful in 61.8% of the teeth, doubtful in 19.1%, and unsuccessful in 19.1%. Clinical signs and symptoms were present in 21.3% of the teeth, occurring significantly more after in teeth demonstrating radiographically unsatisfactory healing.

Adolescent↗
PubMed1992

[Bronchial carcinoid. A clinical, roentgenological and pathological study of 17 cases].

17 cases with bronchial carcinoid were reported. 16 cases of them were proved pathologically after pulmonary resection, and the remaining one was confirmed histopathologically through bronchoscopic biopsy. 64.7% was under 40 years of age. The main clinical manifestations were cough, hemoptysis, fever and repeated pneumonitis. In one patient, the carcinoid was associated with Cushing's syndrome. Chest roentgenograms showed lesions centrally located in 12 cases, and peripherally located in 5 cases. Histological examination revealed 15 typical and 2 atypical carcinoid tumors. This disease was usually misdiagnosed as lung cancer, tuberculoma and benign tumors. Chest X-ray examination and fiberoptic bronchoscopic biopsy are helpful to the diagnosis of the disease. Pulmonary resection was performed in 16 cases. Two patients had hilar lymph node metastases, one of them had also involvement of pericardium. There was no operative mortality. In the follow-up study, the disease-free actuarial survival following pulmonary resection was 92.9% at 5 years. 2 patients died. One died of respiratory failure 4 months after pneumonectomy, the other died of pericardium involvement of carcinoid 8 months after operation. Resection is the only effective treatment for bronchial carcinoid.

Adolescent↗
PubMed1992

Bone mineral density in children with Down's syndrome detected by dual photon absorptiometry.

Bone mineral density (BMD) in ten children with Down's syndrome (seven boys, three girls; aged 10-16 years) was measured by dual photon absorptiometry (DPA) using an M&SE OsteoTech 300 scanner. The BMD of the 2nd to 4th lumbar vertebrae was measured and the mean density presented as g cm-2. The BMD of Down's syndrome was compared with the BMD of normal Chinese children of the same age group. The results showed that the BMD in Down's syndrome was significantly lower compared to that found in normal children (P < 0.01). The percentage of decreased BMD is 8.47 +/- 2.69% (mean +/- 1 S.E.M.) in Down's syndrome compared to normal children of the same age group. The distribution curve of BMD against ages in Down's syndrome has a delay of 2.3 +/- 0.5 (mean +/- 1 S.E.M.) years compared to normal children. In our conclusion, the children with Down's syndrome have lower BMD than the normal children of the same age group. The causes of this abnormality may require further study in the future.

Absorptiometry, Photon↗
PubMed1991

Vasorelaxant effect of emodin, an anthraquinone from a Chinese herb.

The possible mechanism underlying the vasorelaxant effect of emodin isolated from a Chinese herb, was investigated in this study. Emodin dose dependently relaxed isolated vascular rings of human internal mammary artery and saphenous vein, rabbit thoracic aorta, abdominal aorta and mesenteric artery, and rat thoracic aorta. There were no differences in the sensitivity (IC50) and maximal relaxation between intact and endothelium-denuded preparations of rat aorta. In the presence of emodin (10 microM), the contractile responses of rat aorta to phenylephrine, serotonin and potassium chloride were depressed. The relaxation response to acetylcholine was attenuated by emodin, whereas that to isoproterenol was unaffected. The relaxation response to emodin was inhibited by free radical scavengers, superoxide dismutase, catalase and mannitol, and guanylate cyclase inhibitors, methylene blue and hemoglobin. Catalase was the most effective scavenger. Quinacrine (phospholipase A2 inhibitor), indomethacin (cyclooxygenase inhibitor) and nordihydroguaiaretic acid (NDGA, lipoxygenase inhibitor) potentiated the relaxation induced by emodin. NDGA was the most effective potentiator. Exposure of aortic rings to emodin (10 microM) increased the basal level of guanosine 3',5'-cyclic monophosphate (cGMP). It is suggested that the vasorelaxant effect of emodin may be mainly due to cGMP accumulation as a result of guanylate cyclase activation by free radicals and/or hydrogen peroxide generated from semiquinone.

Animals↗
PubMed1991

Comparison of the actions of some platelet-activating factor antagonists on platelets and aortic smooth muscles.

The pharmacological actions of five platelet-activating factor (PAF) antagonists were compared in rabbit platelets and rat thoracic aorta. In PAF (2 ng/ml)-induced aggregation of washed rabbit platelets, WEB 2086 and WEB 2170 much were more potent inhibitors than BN 52021, kadsurenone and denudatin B, and the IC50 values were calculated to be 0.1, 0.3, 5, 8 and 10 micrograms/ml, respectively. WEB 2086, WEB 2170 and BN 52021 did not affect the platelet aggregation caused by collagen (10 micrograms/ml), ADP (20 microM), arachidonic acid (100 microM) or thrombin (0.1 U/ml). Kadsurenone and denudatin B suppressed ATP release, thromboxane B2 formation and the rise in intracellular calcium of washed rabbit platelets caused by collagen and thrombin, while WEB 2086, WEB 2170 and BN 52021 did not have an effect. Norepinephrine (3 microM) induced a sustained contraction in rat thoracic aorta. Pretreatment with these PAF antagonists (20-100 micrograms/ml) caused inhibition of the aortic contraction in the following order: kadsurenone greater than denudatin B greater than WEB 2086 greater than BN 52021 greater than WEB 2170. In high potassium (60 mM)-induced contraction of rat aorta, kadsurenone and denudatin B caused marked relaxation, while WEB 2086, WEB 2170 and BN 52021 had only a slight effect. It is concluded that WEB 2086, WEB 2170 and BN 52021 are specific PAF antagonists in rabbit platelets, and weak relaxants in rat aorta. Two other PAF antagonists, kadsurenone and denudatin B, may inhibit some aspects of signal transduction, e.g., thromboxane formation or intracellular Ca2+ mobilization in rabbit platelets, and cause vasorelaxation in rat aorta by inhibiting calcium influx.

Animals↗
PubMed1991

Crystallization of the IIA domain of the glucose permease of Bacillus subtilis.

The IIA domain of the glucose permease of the phosphoenolpyruvate: sugar phosphotransferase system (PTS) from Bacillus subtilis has been crystallized. Crystals are obtained from ammonium sulfate solution. They diffract to at least 2.2 A resolution, and belong to space group C222(1), with unit cell dimensions: a = 74.2 A; b = 54.9 A; c = 67.0 A.

Bacillus subtilis↗
PubMed1991

Hepatocellular carcinoma in childhood. Clinical manifestations and prognosis.

From December 1964 to November 1989, 71 children from 3 to 17 years of age with the eventual diagnosis of hepatocellular carcinoma (HCC) presented at the National Taiwan University Hospital (Taipei, Taiwan, Republic of China). Forty-three of them had pathologic proof, whereas 28 were diagnosed on a clinical and laboratory basis. A male predominance (M:F = 3.2:1) was noticed. Most patients presented in a late, advanced stage. Abdominal pain and abdominal mass were the major symptoms and signs, followed by anorexia, fever, and internal bleeding. Hydrocele, purpura, and obstructive jaundice were rare presenting symptoms. Hepatosplenomegaly, superficial venous engorgement, and ascites were the main physical signs. The prognosis for such children with HCC was very poor. Only 10% of the patients survived longer than 1 year after the onset of the initial symptom. Among 49 patients who could be followed, only two had long-term survival of over 5 years. One patient had a small HCC with internal bleeding, whereas the other had a large HCC with abdominal distention. Both received surgical resection, and a resection was repeated for tumor recurrence in the patient with the large mass. The resectability of these 71 patients was low (9.8%). Resectability and nonicterus seemed to be the factors indicating favourable prognosis. Observation indicated that the prognosis for children with symptomatic HCC is grave but surgical resection, whenever possible, should be carried out.

Adolescent↗
PubMed1991

Effects of short and long-lasting diabetes mellitus on mouse brain monoamines.

Concentrations of monoamines and their metabolites were investigated in various brain regions of 3, 50, and 100 days diabetic mice. An increase in the content of norepinephrine was observed in the pons-medulla and striatum in short-term (3 days) diabetic mice, and could be sustained for 100 days and 50 days, respectively. In the hypothalamus and cortex, the increase of norepinephrine was observed in both 50 and 100 day diabetic mice, but that of cerebellum was only observed in the 100 day diabetic mice. The concentration of dopamine was increased in the striatum both in short-term and long-term (50 and 100 days) diabetic mice, that of pons-medulla and cortex was increased in the long-term diabetic mice. Concentrations of the acidic metabolites of dopamine, dihydroxyphenylacetic acid and homovanillic acid were decreased in the hypothalamus, hippocampus and striatum, while increased in the pons-medulla and cortex. 5-Hydroxytryptamine concentration was increased in the hypothalamus, hippocampus, pons-medulla and cortex progressively from short-term to long-term diabetic mice. However, the concentration of its acidic metabolite, 5-hydroxyindoleacetic acid, was decreased in the hypothalamus, hippocampus, striatum, pons-medulla and cortex. These data suggest that diabetes is associated with a significant disturbance of brain monoamine metabolism. This disturbance was not generalized but related to some specific areas of the brain and some of these alterations were progressive from short term to long term diabetes.

Animals↗