Isolation of a bacterium resembling Pirellula species from primary tissue culture of the giant tiger prawn (Penaeus monodon).

During attempts to establish tissue cultures from hepatopancreas, heart, and hemolymph of the giant tiger prawn (Penaeus monodon), using a medium including penicillin, streptomycin, and amphotericin B, bacterial contamination in the form of a sheet of growth attached to the tissue culture vessel was a persistent problem. Contaminant bacteria were teardrop-shaped cells arranged in rosettes, and electron microscopy revealed buds, crateriform structures, and the absence of a peptidoglycan layer in the cell wall, features characteristic of bacteria in the Planctomyces-Pirellula group, a phylogenetically distinct group of eubacteria. Two strains of contaminant bacteria were isolated in pure culture. Both exhibited morphology and antibiotic resistance consistent with their membership in the Planctomyces-Pirellula group (order Planctomycetales) of eubacteria. Tissue culture media for marine invertebrates may select for such bacteria if high concentrations of cell wall synthesis-inhibiting antibiotics are included.     

Analysis of copia sequence variation within and between Drosophila species

The sequences of the 5' long-terminal repeat (LTR) and adjacent leader regions of 27 full-length copia elements isolated from natural populations of Drosophila melanogaster, D. simulans, and D. mauritiana are presented. Phylogenetic analyses indicate that although D. melanogaster copia elements are distinct from those of D. simulans and D. mauritiana, the elements of these latter two species are not distinguishable from one another. LTRs and adjacent 5' leader regions of elements isolated from D. simulans and D. mauritiana are structurally similar to one another and carry substantial deletional variation mapping to regions previously identified as being of potential importance for copia expression.      

Comparisons of the molecular evolutionary process at rbcL and ndhF in the grass family (Poaceae)

We examine rate heterogeneity among evolutionary lineages of the grass family at two plasmid loci, ndhF and rbcL, and we introduce a method to determine whether patterns of rate heterogeneity are correlated between loci. We show both that rates of synonymous evolution are heterogeneous among grass lineages and that are heterogeneity is correlated between loci at synonymous sites. At nonsynonymous sites, the pattern of rate heterogeneity is not correlated between loci, primarily due to an aberrant pattern of rate heterogeneity at nonsynonymous sites of rbcL. We compare patterns of synonymous rate heterogeneity to predictors based on the generation time effect and the speciation rate hypotheses. Although there is some evidence for generation time effects, neither generation time effects nor speciation rates appear to be sufficient to explain patterns of rate heterogeneity in the grass plastid sequences.      

Right Ventricular Systolic Dysfunction Is Common in Hypertensive Heart Failure: A Prospective Study in Sub-Saharan Africa

IntroductionRight ventricular (RV) systolic dysfunction is now recognized widely as a strong and independent predictor of adverse outcomes in patients with heart failure (HF). Reduction of RV systolic function more closely predicts impaired exercise tolerance and poor survival than does left ventricular (LV) systolic function. In spite of this, there is a dearth of data on RV function in hypertensive HF which is the commonest form of HF in sub-Saharan Africa. We therefore conducted a prospective cohort study of hypertensive HF patients presenting to the University of Abuja Teaching Hospital, Abuja, Nigeria over an 8 year period.MethodsEach subject had transthoracic echocardiography performed on them according to the guidelines of American Society of Echocardiography. RV systolic function was defined as a tricuspid annular plane systolic excursion (TAPSE) <15mm using M-mode echocardiography.ResultsRV systolic dysfunction was identified in 272 (44.5%) of the 611 subjects that were studied. Subjects with TAPSE less than 15mm had worse prognosis compared to those with TAPSE ≥15mm.There was a significant correlation between TAPSE and other adverse prognostic markers including left and right atrial area, LV size, LV mass, LV ejection fraction, restrictive mitral inflow and RV systolic pressure (RVSP). However, LV ejection fraction and right atrial area were the only independent determinants of RV systolic dysfunction.ConclusionsHypertensive HF is a major cause of RV systolic dysfunction even in a population with a low prevalence of coronary artery disease, and RV systolic dysfunction is associated with poor prognosis in hypertensive HF. Detailed assessment of RV function should therefore be part of the echocardiography evaluation of patients with hypertensive HF.     

Fission fragment RBE for bone sarcoma induction

Thirty beagles and 277 mice were injected with 249Cf, and 30 beagles and 274 mice were injected with 252Cf. The skeletal dose (in Gy) from 252Cf was about half from fission fragments and half from alpha particles, whereas 249Cf emits alpha particles in 100% of its transformations. Bone sarcomas (mostly osteosarcomas) were the main radiation-induced cancer. The relative biological effectiveness (RBE) of fission fragment dose relative to alpha-particle dose for bone sarcoma induction was calculated from the ratio of 249Cf/252Cf doses at equal times to bone sarcoma in (a) beagles and (b) mice, and (c) from the ratio 252Cf/249Cf risk coefficients in mice. The average RBE +/- standard deviation of the three evaluations was 0.1 +/- 0.1. The very low RBE for bone sarcomas is supported by the data of A. L. Batchelor, T. J. Jenner, and L. M. Cobb [Phys. Med. Biol. 28, 475-483 (1983)] for lung cancer induction in rats and by that of A. L. Brooks, J. A. Mewhinney, and R. O. McClellan [Health Phys. 22, 701-706 (1972)] for producing chromosome aberrations in the liver cells of Chinese hamsters. The low effectiveness of fission fragments relative to alpha particles, per gray of absorbed dose, is ascribed primarily to the much larger number of cells traversed by the alpha particles. Consideration might be given to decreasing the quality factor of fission fragments by an order of magnitude below that for alpha particles.     

CARBOHYDRATE-PEPTIDE LINKAGES IN GLYCOPROTEINS AND MUCOPOLYSACCHARIDES FROM BRAIN

Abstract— Treatment of glycopeptides, prepared from glycoproteins of rat and rabbit brain, with NaOH-NaBH₄ leads to the destruction of a portion of the serine, threonine and galactosamine present, and the appearance in acid hydrolysates of alanine, α-aminobutyric acid and galactosaminitol. These results indicate that N-acetylgalactosamine at the reducing end of oligosaccharide chains in brain glycoproteins is linked O-glycosidically to the hydroxyl groups of serine and threonine residues. 2-acetamido-1-(L-β-aspartamido)-l,2-dideoxy-β-D-glucose was also detected after partial acid hydrolysis of the alkali-stable glycopeptides, and most of the carbohydrate in brain glycoproteins appears to be linked by N-acetylglucosaminylasparagine linkages. The results of the treatment of the sulphated mucopolysaccharides from bovine brain with alkaline-borohydride indicate that the polysaccharide chains in chondroitin sulphate and heparan sulphate are linked exclusively to serine.