The effects of catabolic and anabolic steroids on amino acid incorporation by skeletal-muscle ribosomes

1. A method is described for the routine isolation of ribosomes from small quantities of skeletal muscle that have been homogenized with the Ultra-Turrax tissue disintegrator. 2. Ribosomes prepared by this method from rats receiving triamcinolone acetonide or rabbits receiving cortisone acetate show a marked fall in their ability to incorporate amino acids when compared with ribosomes from control animals. 3. This fall in activity can be partially prevented in rats by pretreating the animals with an anabolic steroid, steroid 36644-Ba. 4. Testosterone (5mg./kg.) administered to rabbits in conjunction with cortisone acetate is not effective in maintaining ribosomal activity. However, steroid 36644-Ba at one-tenth of an equiandrogenic dose (0.05mg./kg.) is extremely effective. 5. The results with ribosomes isolated from rabbits support the concept that steroid 36644-Ba and possibly all anabolic steroids have an ability to counteract the catabolic action of corticosteroids that is greater than their androgenic activity would suggest.     

A method for aeration and foam control in fermentation vessels

The production of large quantities of microbial mass, or their by-products, frequently requires aeration and mixing of fluid media. This operation often results in copious production of foam which cannot be exhausted with the effluent air or gas. Foam is usually controlled with antifoam agents which may interfere with product purity, oxygen uptake, and with subsequent product, handling. The process herein described obviates the requirement for antifoam agents or other foam-control methods. In essence, the air (or other gases) and foam in the headspace are continuously withdrawn, entrained in the intake side of a self-priming pump, and reintroduced into the bulk of the process liquid medium. The headspace may be enriched with oxygen or other gases.     

Superoxide dismutase in ruminal bacteria.

Of 13 species of anaerobic ruminal bacteria examined, 11 were found to contain measurable levels of superoxide dismutase activity. Four of five other strict anaerobic species studied for comparison were found to contain superoxide dismutase activity.     

Calcium response to erythropoietin in erythroleukemia cells

Erythroleukemic mouse spleen cells were analyzed by flow cytometry at three fluorescence wavelengths, two emissions for the calcium indicator indo 1 and immunofluorescence with an antiserum directed against murine leukemia retrovirus antigen. The antigen-positive subpopulation of cells responded to EPO by transiently changing indo 1 fluorescence emissions, indicating a change in cytoplasmic calcium concentration. EGTA blocked the EPO response, suggesting that Ca2+ influx may have followed EPO exposure in these cells. Antigen-negative cells showed no Ca2+ response to EPO. Infected mice all contained antigen-positive spleen cells, but, as measured by changes in indo 1 fluorescence, these subpopulations varied in their ability to respond to EPO.     

Superoxide dismutase in ruminal bacteria

Of 13 species of anaerobic ruminal bacteria examined, 11 were found to contain measurable levels of superoxide dismutase activity. Four of five other strict anaerobic species studied for comparison were found to contain superoxide dismutase activity.     

Treatment of Low Angle X-Ray Data from Planar and Concentric Multilayered Structures

Low angle X-ray diffraction can be recorded from planar and concentric multilayered (biological) structures. In order to proceed with the X-ray analysis the relation between the observed intensities and the Fourier transform of the unit cell is required. This relation is derived for planar structures such as retinal rods, mitochondria, and collagen; and also for nerve myelin.     

Angiographic studies of quinton—scribner arteriovenous cannulae

An analysis of 86 angiographic studies of Quinton–Scribner shunts has shown that these may be very useful in determining the cause and helping in the management of poorly functioning cannulae in patients on regular haemodialysis treatment.     

Cutting edge: Critical role for A2A adenosine receptors in the T cell-mediated regulation of colitis

A(2A) adenosine receptors (A(2A)AR) inhibit inflammation, although the mechanisms through which adenosine exerts its effects remain unclear. Although the transfer of regulatory Th cells blocks colitis induced by pathogenic CD45RB(high) Th cells, we show that CD45RB(low) or CD25+ Th cells from A(2A)AR-deficient mice do not prevent disease. Moreover, CD45RB(high) Th cells from A(2A)AR-deficient mice were not suppressed by control CD45RB(low) Th cells. A(2A)AR agonists suppressed the production of proinflammatory cytokines by CD45RB(high) and CD45RB(low) T cells in association with a loss of mRNA stability. In contrast, anti-inflammatory cytokines, including IL-10 and TGF-beta, were minimally affected. Oral administration of the A(2A)AR agonist ATL313 attenuated disease in mice receiving CD45RB(high) Th cells. These data suggest that A(2A)AR play a novel role in the control of T cell-mediated colitis by suppressing the expression of proinflammatory cytokines while sparing anti-inflammatory activity mediated by IL-10 and TGF-beta.