Distinguishing between mechanisms of eukaryotic transcriptional activation with bacteriophage T7 RNA polymerase

To distinguish between mechanisms of eukaryotic transcriptional activation, we tested whether yeast upstream promoter elements can stimulate transcription by a heterologous transcription machinery, bacteriophage T7 RNA polymerase. The gal enhancer-like element recognized by GAL4 protein or the ded1 poly(dA-dT) element was placed upstream of the T7 promoter and his3 structural gene, and T7 RNA polymerase was produced in yeast cells. Under conditions where the gal element would normally be either activating or nonactivating, his3 transcription by T7 RNA polymerase was not stimulated above the level observed in the absence of any upstream element. In contrast, the ded1 poly(dA-dT) element stimulated transcription 7-fold, similar to the enhancement observed on the native ded1 promoter. Activation by the ded1 element thus may involve effects on the chromatin template that facilitate entry of the transcription machinery, whereas activation by the gal element may involve specific contacts between GAL4 and the transcriptional machinery.

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.

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.

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.

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.

[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.

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.

Anaerobic degradation of veratrylglycerol-beta-guaiacyl ether and guaiacoxyacetic acid by mixed rumen bacteria

Veratrylglycerol-beta-guaiacyl ether (0.2 g/liter), a lignin model compound, was found to be degraded by mixed rumen bacteria in a yeast extract medium under strictly anaerobic conditions to the extent of 19% within 24 h. Guaiacoxyacetic acid, 2-(o-methoxyphenoxy)ethanol, vanillic acid, and vanillin were detected as degradation products of veratrylglycerol-beta-guaiacyl ether by thin-layer chromatography, gas chromatography, and gas chromatography-mass spectrometry. Guaiacoxyacetic acid (0.25 g/liter), when added into the medium as a substrate, was entirely degraded within 36 h, resulting in the formation of phenoxyacetic acid, guaiacol, and phenol. These results suggest that the beta-arylether bond, an important intermonomer linkage in lignin, can be cleaved completely by these rumen anaerobes.

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.

Degradation of Dehydrodivanillin by Anaerobic Bacteria from Cow Rumen Fluid

Dehydrodivanillin (DDV; 0.15 g/liter) was biodegradable at 37°C under strictly anaerobic conditions by microflora from cow rumen fluid to the extent of 25% within 2 days in a yeast extract medium. The anaerobes were acclimated on DDV for 2 weeks, leading to DDV-degrading microflora with rates of degradation eight times higher than those initially. Dehydrodivanillic acid and vanillic acid were detected in an ethylacetate extract of a DDV-enriched culture broth by thin-layer, gas, and high-performance liquid chromatographies and by mass spectrometry.