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Biomedical subjects

W Chen

Publications and source records attributed to W Chen.

At least 1,189 records · Page 66Linked to original sources
PubMed1987

Proton magnetic resonance spectral patterns of metastasizing and nonmetastasizing human colon cancers.

The spectral features of surgically staged metastasizing (ie, modified Duke's stages C and D) and nonmetastasizing (ie, modified Duke's stages A and B1-2) human colon cancers were studied using 60-MHz continuous wave and 200-MHz pulse Fourier transform proton magnetic resonance spectroscopy. Twenty-one human colon cancers (four nonmetastasizing and 17 metastasizing tumors) collectively contained 24 spectral peaks. A peak at 6.7 to 6.87 parts per million cycles (ppm) was found in three nonmetastasizing tumors but only one metastasizing tumor; the mean area at this peak location was significantly higher in the nonmetastasizing tumors. Mean peak areas at 1.4 to 1.47 ppm, 2.0 to 2.33 ppm, and 8.3 to 8.6 ppm were significantly higher in metastasizing tumors; however, these peaks were observed with only marginally greater frequency in metastasizing vs nonmetastasizing tumors: seven of 17 vs zero of four, 11 of 17 vs one of four, and eight of 17 vs zero of four tumors, respectively. This study suggests that magnetic resonance spectral features may aid in staging human colon cancers and could be used to enhance magnetic resonance imaging of these lesions.

Colonic Neoplasms↗
PubMed1987

Intergeneric protoplast fusion between Fusobacterium varium and Enterococcus faecium for enhancing dehydrodivanillin degradation.

Intergeneric protoplast fusion between Fusobacterium varium (Pcs Glu+) and Enterococcus faecium (Pcr Glu-) was performed under strictly anaerobic conditions to improve dehydrodivanillin (DDV) degradation. The fusion frequency obtained from the selective medium (Pc+ Glu-) was about 0.9 X 10(-5) to 1.3 X 10(-5). The seven fusants isolated were all gram-negative anaerobes with rod shapes like that of F. varium and with main phenotypical properties of cocci like those of E. faecium such as esculin and starch hydrolysis, milk clotting, and lactate production. Five fusants showed enhanced DDV degradation activities that were 2 to 4 times higher than those of parental strains. Genetic relatedness between a fusant (FE7) and the parents was estimated by DNA-DNA Southern blot hybridization with 32P-labeled chromosomal DNA fragments of F. varium and E. faecium as respective probes. The fusant FE7 presented a very high cross-hybridization with both probes, indicating a high DNA homology between the fusant and both parental strains. Almost all the fusants obtained here have stably kept the properties described above for about 2 years. These results suggest that intergeneric gene transfer takes place through protoplast fusion and that the fusants that were obtained are stable recombinants.

Anaerobiosis↗
PubMed1986

Technetium 99m-DTPA microcapsules: a new preparation for gastric emptying studies.

Technetium 99m-DTPA microcapsules have been developed to measure gastric emptying. Such capsules not only provide high labeling efficiency in vitro, but demonstrate limited dissociation in vivo, resulting in decreased error during measurement. In normal control subjects, the half-life ranged from 40 to 80 minutes under the aforementioned conditions.

Adult↗
PubMed1986

Hemorrhoids or rectal varices: defining the cause of massive rectal hemorrhage in patients with portal hypertension.

Identifying the source of lower gastrointestinal hemorrhage in patients with chronic liver disease and portal hypertension can be challenging. We present 2 cases of hemorrhage from rectal varices and a discussion on the differences between simple hemorrhoids and rectal varices. Evaluation of rectal bleeding in patients with portal hypertension is discussed and possible therapeutic options are described.

Adult↗
PubMed1986

Protoplast formation and regeneration of dehydrodivanillin-degrading strains of Fusobacterium varium and Enterococcus faecium.

Two strains of rumen anaerobes isolated from dehydrodivanillin-degrading cultures were identified as Fusobacterium varium and Enterococcus faecium. These organisms degraded dehydrodivanillin synergistically to 5-carboxymethylvanillin and vanillic acid. Specific conditions for protoplast formation and cell wall regeneration for both bacteria were determined, under strictly anaerobic conditions, to be as follows. The cell wall of each bacterium in yeast extract medium was loosened by adding penicillin G during early log-phase growth. The cell wall of F. varium was lysed by lysozyme (1 mg/ml) in glycerol (0.2 M)-phosphate buffer (0.05 M; pH 7.0). The addition of NaCl (0.08 M) with lysozyme was necessary for lysis of E. faecium in this solution. Almost all cells were converted to protoplasts after 2 h of incubation at 37 degrees C. Regeneration of both protoplasts was 20 to 30% on an agar-containing yeast extract medium.

Anaerobiosis↗
PubMed1986

Effect of EMG-biofeedback training in reduction of muscle tension for individuals displaying type A behavior patterns.

This study investigated the effect of EMG biofeedback training in reducing muscle tension among subjects who displayed Type A behavior. 22 Type A college students (19 to 22 yr. old) were randomly assigned to either a biofeedback group or a control group. After 6 wk. of training, Type A subjects showed a significant reduction in muscle tension for both resting and aroused states; however, the reduction of muscle tension did not result in reduction of Type A behavior patterns.

Adult↗
PubMed1986

[Combination of radiation, chemotherapy and surgery in rectal cancer--an analysis of 128 patients].

The results of 128 patients with rectal cancer treated by the combination of surgery, preoperative radiotherapy and chemotherapy from June 1975 to December 1979 are reported and compared with those by operation alone. The 5 year survival rates of the different groups were: 69.5% (16/23) for radical surgery plus preoperative radiotherapy and chemotherapy (RRCG), 56% (14/25) for radical surgery plus preoperative radiotherapy, 53.8% (7/13) for radical surgery plus chemotherapy and 40% (10/25) for radical surgery alone. The 5 year survival rate of RRCG was significantly higher than that of the radical surgery alone group (P less than 0.05). The authors believe that the combination of preoperative radiotherapy, chemotherapy plus radical surgery improves the 5 year survival rate and is worthy of further study.

Adenocarcinoma↗
PubMed1985

Yeast mRNA initiation sites are determined primarily by specific sequences, not by the distance from the TATA element.

We present evidence suggesting that accurate mRNA initiation in yeast cells, unlike their higher eukaryotic counterparts, is determined primarily by specific sequences downstream from the TATA element. First, changing the distance between the his3 TATA element and the initiation region does not affect the sites of initiation or the level of RNA. Second, reciprocal his3-ded1 and ded1-his3 hybrid promoters containing the upstream and TATA elements of one gene fused to the mRNA coding region of the other gene initiate transcription at sites defined by wild-type mRNA coding sequences, not by the distance from the TATA element. Third, when the his3 or ded1 promoter region is fused to position +2 of the his3 gene, transcripts initiated from a position equivalent to +1 are not observed. The results also suggest that the spacing between the TATA element and initiation site is relatively flexible; distance ranging from 40 to 90 bp appear to be functionally acceptable.

Base Sequence↗