Isolation and characteristics of a wheatbran-degrading Butyrivibrio from human faeces

Screening over 100 isolates from human faeces for cellulolytic activity led to the isolation of a weakly cellulolytic anaerobic, curved, motile bacterium which produced H₂, lactate and butyrate from wheatbran. The mol% of G + C in the DNA was 39–42. These properties, together with the Gram-positive cell wall ultrastructure and SDS-PAGE profile, are consistent with the genus Butyrivibrio. The isolate is believed to be the most active wheatbran-degrading bacterium so far described.     

Purification, sequencing and functions of calreticulin from maize

The most abundant proteins in the lumen of the endoplasmic reticulum(ER) are thought to be molecular chaperones, some of which mightalso be involved in calcium storage and release. We have purifiedcalreticulin from maize by ion exchange and reverse-phase chromatography.Identity with plant and animal calreticulins was confirmed byN-terminal amino acid sequencing and it was shown to bind calciumwith a calcium overlay technique. An antiserum raised to thepurified protein was used to screen an expression library andthe full coding sequence for maize calreticulin was determinedfrom the clones selected. The sequence shows 96% identity tobarley calreticulin and 55% identity to animal calreticulins.The three major functional regions are conserved, as are targetingand retention features. When visualized by indirect immunofluorescencemicroscopy, calreticulin was found to be confined to the ERand nuclear envelope of maize root cells. It was distributedthroughout the ER compartment and we found no evidence of calreticulin-enriched areas of ER, such as might be associated with specializedcalcium storage domains. Increasing or decreasing extracellularcalcium did not induce measurable changes in calreticulin levels.In addition, maize calreticulin, as well as other recognizedchaperones, was shown to bind to denatured protein and couldbe eluted specifically by nucleoside trisphosphates. Key words: Endoplasmic reticulum, calcium-binding protein, immunofluorescence, targeting, Zea mays L     

Nucleolar localization of parathyroid hormone-related peptide enhances survival of chondrocytes under conditions that promote apoptotic cell death.

Parathyroid hormone-related peptide (PTHrP) is a mediator of cellular growth and differentiation as well as a cause of malignancy-induced hypercalcemia. Most of the actions of PTHrP have been attributed to its interaction with a specific cell surface receptor that binds the N-terminal domain of the protein. Here we present evidence that PTHrP promotes some of its cellular effects by translocating to the nucleolus. Localization of transiently expressed PTHrP to the nucleolus was dependent on the presence of a highly basic region at the carboxyl terminus of the molecule that bears homology to nucleolar targeting sequences identified within human retroviral (human immunodeficiency virus type 1 and human T-cell leukemia virus type 1) regulatory proteins. Endogenous PTHrP also localized to the nucleolus in osseous cells in vitro and in vivo. Moreover, expression of PTHrP in chondrocytic cells (CFK2) delayed apoptosis induced by serum deprivation, and this effect depended on the presence of an intact nucleolar targeting signal. The present findings demonstrate a unique intracellular mode of PTHrP action and a novel mechanism by which this peptide growth factor may modulate programmed cell death.     

The mechanism of inhibition of ureogenesis by acidosis

In perfused rat liver a decrease of cytosol pH, determined with pH-sensitive microelectrodes7 from 7.2 to 6.85 is associated with a 50% fall in ureogenesis from ammonium chloride. In isolated rat hepatocytes the fall in ureogenesis due to acidosis is associated with decrease in the mitochondrial and cytosolic concentration of citrulline. Limitation of carbamoyl phosphate synthesis and thus citrulline supply could be responsible for the inhibition of ureogenesis observed.     

Acetylation of rat testis histones H2B and TH2B

The in vivo acetylation of rat testis histones H3 and H4 has been demonstrated in previous studies. In this study, analysis of purified histone fractions revealed the in vivo acetylation of histone H2B, the testis histone variant designated TH2B, and two or more of the histone H2A variants. These findings are quite significant, because it is possible that all of the core histones are acetylated in elongating spermatids at the time of removal of the entire histone complement for replacement by basic spermatidal transition proteins (S.R. Grimes and N. Henderson, 1983, Arch. Biochem. Biophys. 221, 108-116).     

Identification, physical map location and sequence of the denV gene from bacteriophage T4

The denV gene from bacteriophage T4, which codes for endonuclease V, a small DNA repair enzyme, has been cloned and identified by an approach combining DNA sequencing and genetics, independent of the phenotypic effect of the cloned gene. Appropriate DenV+ and DenV- deletion mutants were mapped physically to define precisely a region encompassing the denV gene. This region was sequenced in order to identify a protein-coding sequence of the correct size for the denV gene (400-500 bp). Finally, identification was confirmed by sequencing the corresponding fragments cloned from four genetically and phenotypically well-characterized denV mutants. The denV gene is located at 64 kb on the T4 genome, adjacent to the ipII gene, and codes for a basic protein of 138 amino acids with a deduced molecular weight of 16,078.     

Results of the peer assessment program of the College of Physicians and Surgeons of Ontario.

This paper describes the experience of the College of Physicians and Surgeons of Ontario in developing and conducting a program for the peer assessment of physicians'' office practices that would allow the standards of medical practice to be reviewed and assessed. Following two pilot projects in 1978 and 1979 that demonstrated the need, the feasibility and the acceptance of a peer assessment program the office practices of 391 randomly selected physicians were reviewed in 1981 and 1982. Included in the sample were 255 general/family practitioners and 136 specialists in seven fields. Serious deficiencies were found in the medical records of or in the care provided by 30 of the general/family practitioners and 3 of the specialists, accounting for 8% of the practices studied. The difference between the two groups of physicians was statistically significant (p less than 0.01). No predictors of significance were demonstrated in the general/family practitioner group. When follow-up assessments were done most of the physicians were found to have made the improvements that had been recommended.     

Instant age-sex register.

An age-sex register for use in general practice was obtained directly from the family practitioner committee computer by direct transfer of data to a microcomputer.     

Cycling of organic and inorganic sulphur in a chestnut oak forest

Summary Sulfur (S) cycling in a chestnut oak forest on Walker Branch Watershed, Tennessee, was dominated by geochemical processes involving sulfate. Even though available SO ₄ ^2- was present far in excess of forest nutritional requirements, the ecosystem as a whole accumulated 60% of incoming SO₄–S. Most (90%) of this accumulation occurred by SO ₄ ^2- adsorption in sesquioxide-rich subsurface soils, with a relatively minor amount accumulating and cycling as SO ₄ ^2- within vegetative components. Organic sulfates are thought to constitute a large proportion of total S in surface soils, also, and to provide a pool of readily mineralized available S within the ecosystem.Research sponsored by Division of Biomedical and Environmental Research, U.S. Department of Energy, under contract W-7405-eng-26 with Union Carbide Corporation. Soil ester sulfate work sponsored by contract RP-1813-1 with the Electric Power Research Institute. Publication No. 1990, Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830