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Biomedical subjects

B F Chen

Publications and source records attributed to B F Chen.

At least 73 records · Page 4Linked to original sources
PubMed1990

Extralobar pulmonary sequestration of the left retroperitoneum.

This paper presents an extralobar pulmonary sequestration in the left retroperitoneum in an eight year old girl. The clinical and diagnostic features included abdominal pain, an abdominal mass, elevated VMA, and radiological manifestations simulating a left adrenal mass. A laparatomy was performed. Extralobar pulmonary sequestration of the left retroperitoneum is fairly uncommon. An eight year old girl was admitted with abdominal pain, elevated urinary VMA and an abdominal mass. The radiological manifestations simulated a left adrenal mass. At surgery an extralobar pulmonary sequestration was detected.

Bronchopulmonary Sequestration↗
PubMed1990

Neuro-endocrine type of gastric carcinoma. Immunohistochemical and electron microscopic studies of 100 cases.

1,351 specimens resected surgically from 100 patients with gastric carcinoma were studied with PAP immunoperoxidase and ultrastructural method. The tumor cells were found positive for gastrin, serotonin, somatostatin and argyrophil particles in 19 patients. Among them the gastrin-secreting tumor cells consisted of 50% of the total in 4 cases, representing a separate new subtype, neuro-endocrine (NE) gastric carcinoma. Of the 100 cases, 16 (32%) contained NE cells among 50 undifferentiated type, while only 3 cases (6%) contained NE cells among the remaining 50 cases, the well-differentiated type. These results suggest that the appearance of NE tumor cells is closely correlated with the degree of differentiation of cancer, and confirms theoretically the heterogenicity of gastric carcinoma, and further supports the concept that exocrine and endocrine type gastric cancer cells are isogenous, i.e., from the endodermal stem cells.

Adenocarcinoma, Mucinous↗
PubMed1990

[Malignant melanoma metastatic to the stomach: upper G-I endoscopic finding--report of a case].

a 54-year-old male was presented with huge, black, ulcerative and painless tumor of the sole of left foot. Malignant melanoma was proved by biopsy, but patient refused any treatment. He visited our hospital again when bloody vomitus was noted two months later. Chest P-A revealed multiple lung metastases, and marked liver metastasis was also found by abdominal echo. Upper gastrointestinal (UGI) panendoscopy revealed multiple melanotic nodules with ulcerations at the tip, scattering diffusely on the fundus and upper body of the stomach. Metastatic malignant melanoma was proved by endoscopic biopsy. Metastatic tumor of the stomach was rare, and the endoscopic finding of the malignant melanoma with gastric metastasis was more rarer in the literature in Taiwan. So we would like to present the very rare finding of the endoscopy.

Gastroscopy↗
PubMed1990

[Pathohistology of progressive muscular dystrophy and the relationship between necrotic and regenerative fibers].

Enzyme histochemistry and acridine orange (AO) fluorescence techniques were used for studying muscle biopsy specimens of progressive muscular dystrophy in 75 cases. Five characteristic pathologic patterns for diagnosis were summarized. The level of serum CPK was be used as a marker for judging necrotic fibers. The result of AO staining showed that the number of regenerating IIc type fibers in DMD increased by 5-20%. This indicates that the numbers of the IIc type fibers are also related to necrotic fibers. The authors consider that the regenerative course is a compensatory repair reaction on necrotic fibers. But clinically, the speed of necrosis development is much higher than that of regeneration. Thus, enhancing the synthesis of proteins and promoting the capacity of regeneration should be considered as a new approach to effective therapy for DMD patients.

Adolescent↗
PubMed1989

Secondary biliary cirrhosis. A limiting factor in the treatment of hepatolithiasis.

To investigate whether the coexistence of secondary biliary cirrhosis plays a limiting role in the treatment of hepatolithiasis, we retrospectively compared the clinical course and results of stone treatment in 30 patients with secondary biliary cirrhosis (8 in Child's class A and 22 in Child's class B) (group 1) and 240 patients with noncirrhotic biliary calculi (group 2). The hospital mortality, morbidity of treatment, mortality of treatment, and the percentage of treatment failure in group 1 were 20%, 40%, 6.7%, and 16.7%, respectively. Those in group 2 were 8%, 10%, 3.8%, and 10%, respectively. The modes of treatment for stone removal included surgery with postoperative cholangioscopy and percutaneous transhepatic cholangioscopy. There was a statistically significant difference between these two groups in the hospital mortality and the morbidity of treatment. We conclude that hepatolithiasis and biliary stricture should be treated early, before the development of secondary biliary cirrhosis. However, even after cirrhosis occurs, aggressive treatment does not increase the mortality of treatment or the treatment failure rate.

Adult↗
PubMed1988

Mechanism of ATP inhibition of mammalian type I DNA topoisomerase: DNA binding, cleavage, and rejoining are insensitive to ATP.

A general, unrefined mechanism of type I DNA topoisomerase action involves several steps including DNA binding, single-strand scission, strand passage resealing, and, possibly, readoption of an active enzyme conformation. None of these steps requires an energy cofactor; however, we have shown previously that several mammalian type I topoisomerases are, in fact, inhibited by ATP. In this study, we wanted to examine which steps in the gross topoisomerase mechanism were sensitive or insensitive to ATP. Nitrocellulose filter binding experiments showed that ATP did not interfere with the binding of DNA by the enzyme and that ATP binding by topoisomerase was 5-fold greater in the presence of DNA than in its absence. Agarose gel electrophoresis in the presence or absence of ethidium bromide indicated that resealing was unaffected by added ATP. The addition of the adenine nucleotide did not alter the pattern of camptothecin-stimulated cleavage of DNA, indicating that strand scission was not the point of inhibition. To test whether strand passage or the readoption of an active conformation was an inhibited step, we used a unique DNA topoisomer as substrate. The results argued against readoption of an active enzyme conformation as an ATP-sensitive process.

Adenosine Triphosphate↗
PubMed1988

A trans-acting gene is required for the phenotypic expression of a tyrosinase gene in Streptomyces.

The melanin locus (melC) from Streptomyces antibioticus was previously shown to be composed of two open reading frames (ORFs), melC1 and melC2. The melC2 ORF codes for the polypeptide chain of tyrosinase (apotyrosinase). The function of melC1 is not known except that insertional mutation within it abolishes the tyrosinase activity. Here, we show that in Streptomyces lividans TK64 harboring melC1 mutated and melC2 intact (melC1- melC2+) plasmids, while there was no tyrosinase activity, melC transcript was synthesized and apotyrosinase could be detected. The apotyrosinase could be activated to a limited degree by incubation with copper ions, or by mixing the mycelial extract from a culture harboring a melC1- melC2+ (pPF950) plasmid with that from a culture containing a melC1+ melC2- (pSA1) plasmid. Complementation analysis showed that melC1 acted in trans on the tyrosinase gene expression. Together, these results suggest that melC1 encodes or regulates a copper-transfer protein serving an in vivo copper-donor function in the biosynthesis of active tyrosinase.

Catechol Oxidase↗
PubMed1988

[Study on neuro-endocrine type of gastric carcinoma].

One hundred patients with gastric carcinoma resected surgically were studied by PAP immunoperoxidase and ultrastructural method. It was found that the tumor cells were positive for gastrin, serotonin, somatostatin as well as argyrophil particles in 19 patients. In these 19 patients, the quantity of endocrine tumor cells surpassed half of its total cancer cells in 4, leading to a separate entity of neuroendocrine gastric carcinoma. The authors hope to introduce this new subtype into the classification of gastric carcinoma. Among the 100 cases, 50 patients with undifferentiated carcinomas contained the NE cells in 16 (32%), the remains for high differentiated adenocarcinomas had the NE cells in 3 (6%) only. It was suggested that the appearance of NE tumor cells was closely correlated to differentiation of gastric carcinoma. This study theoretically demonstrated the heterogenicity of gastric carcinoma and supported the theory that different kinds of tumor cells (endocrine and nonendocrine) may have a common origin and are derived from the endoembryogenetic immature precursor cells.

Adenocarcinoma↗
PubMed1987

Computed tomography of a meniscal cyst.

A meniscal cyst of the knee is a rare lesion, and a palpable large meniscal cyst is even more rare. This article suggests that CT scan demonstrates clear location, size, contents, and connection of the cyst with meniscus and peripheral tissue. By a combination of arthrography and CT scan, detection of the cysts in zone 3 (parameniscal area) is possible with ample demonstration of whether the cyst is associated with a meniscal tear. This provides a guideline in determining the treatment of the lesion.

Adult↗
PubMed1986

Application of avidin-biotin-peroxidase complex method with a monoclonal antibody to human Ia-like antigen in immunoelectron microscopy.

Monoclonal antibody (MAb) to human Ia-like (HLA-DR) antigen was applied with the avidin-biotin-peroxidase complex (ABC) immunostaining method to localize the Ia-like antigen at the electron microscopic level. Our results indicated that in human tonsils and adenoids fixed with 4-6% phosphate-buffered paraformaldehyde for 4-6 hr, sharply delineated electron-dense products of the antigen and antibody complex were detectable on the outer cell membranes of lymphoblasts, lymphocytes, reticular cells, and macrophages. In our study, the vibratome sections of the paraformaldehyde-fixed, pre-embedding immunostained tissues consistently showed more satisfactory morphology than frozen sections. The combined use of the anti-human Ia monoclonal antibody and the ABC procedure with paraformaldehyde fixation provides a simple and sensitive method to study at the ultrastructural level the Ia-like antigen-bearing cells, which are vital in the immune response.

Adenoids↗
PubMedDate not supplied

En bloc resection for extensive hepatocellular carcinoma: is it advisable?

When the adjacent organ is partially invaded by a hepatocellular carcinoma (HCC), whether to go on an aggressive resection is a difficult but challenging problem. To investigate the worth of en bloc resections, a retrospective controlled study was conducted. During a 9-year period, nine patients (seven men, two women: group I) who had HCC with invasions to extrahepatic adjacent organs had undergone en bloc resections. The adjacent organs included diaphragm (eight cases), adrenal gland (two cases), abdominal wall (one case), and spleen (one case). The patients selected for en bloc resections were those with a solitary tumor without evidence of vascular invasion or intravascular tumor thrombi, daughter nodule(s), or distant metastasis. The evidence was based on preoperative evaluation by ultrasonography, computed tomography, arteriography, and intraoperative ultrasonography. Eighteen matched patients with HCC but no involvement of neighboring organs were selected as controls (14 men, 4 women: group II). Though patients of group I had wider invasion of HCC and more extensive resection, their surgical morbidity, mortality, hospital mortality, disease-free interval, and survival time were similar to those of group II, who had more limited HCC and resections. Eighteen months after operation, the HCC recurrence rate was 44% and 41% in groups I and II, respectively, and the percent survivals were 71% and 63%, respectively. We suggest that in cases of large HCC with local invasion to neighboring organs, aggressive en bloc resection is recommended after appropriate patient selection.

Carcinoma, Hepatocellular↗
PubMedDate not supplied

Pancreatic tumors in children: report of three cases.

From 1981 to 1996, we experienced 3 cases of pancreatic tumors in children--two pancreatoblastomas (PB) and one solid and cystic tumor (SCT). The ages were 1 month, 4 years, and 13 years of age respectively. The two cases of pancreatoblastoma initially presented as chronic diarrhea with failure to thrive, the other case presented with abdominal mass. All of them were studied by laboratory examination, ultrasonography, computed tomography and pathology. Increasing alpha- fetoprotein (AFP) levels were found in the 2 pancreatoblastoma cases, however, the level in the SCT case was normal. Abdominal sonography showed pancreatic masses with or without calcification, and the echogenicity may be solid and/or cystic. All patients underwent total excision of the tumors. We have reviewed the literature and find no pancreatoblastoma with chronic diarrhea was reported in young children, especially in neonate. Therefore, we suggest that young children presenting with an abdominal mass and/or weight loss should undergo imaging studies for the possibility of pancreatic tumors.

Adolescent↗