Comparison of the genome sequence of the poultry pathogen Bordetella avium with those of B. bronchiseptica, B. pertussis, and B. parapertussis reveals extensive diversity in surface structures associated with host interaction

Bordetella avium is a pathogen of poultry and is phylogenetically distinct from Bordetella bronchiseptica, Bordetella pertussis, and Bordetella parapertussis, which are other species in the Bordetella genus that infect mammals. In order to understand the evolutionary relatedness of Bordetella species and further the understanding of pathogenesis, we obtained the complete genome sequence of B. avium strain 197N, a pathogenic strain that has been extensively studied. With 3,732,255 base pairs of DNA and 3,417 predicted coding sequences, it has the smallest genome and gene complement of the sequenced bordetellae. In this study, the presence or absence of previously reported virulence factors from B. avium was confirmed, and the genetic bases for growth characteristics were elucidated. Over 1,100 genes present in B. avium but not in B. bronchiseptica were identified, and most were predicted to encode surface or secreted proteins that are likely to define an organism adapted to the avian rather than the mammalian respiratory tracts. These include genes coding for the synthesis of a polysaccharide capsule, hemagglutinins, a type I secretion system adjacent to two very large genes for secreted proteins, and unique genes for both lipopolysaccharide and fimbrial biogenesis. Three apparently complete prophages are also present. The BvgAS virulence regulatory system appears to have polymorphisms at a poly(C) tract that is involved in phase variation in other bordetellae. A number of putative iron-regulated outer membrane proteins were predicted from the sequence, and this regulation was confirmed experimentally for five of these.     

Dynamic light scattering from polydisperse suspensions of large spheres. Characterization of isolated secretory granules.

Dynamic light scattering is useful in determining the diameter of submicrometer particles in suspension. When both static scattering intensity P(K) and apparent diffusion coefficient D can be measured in a wide range of the length of the scattering vector K, it is possible to determine the number-average diameter dn and sharpness in size distribution of spheres. We derived approximate, but very simple, expressions for mean value of P(K) and mean value of D/D(dn) applicable to very large spheres for which the so-called Rayleigh-Debye condition is perturbed, where mean value of ... stands for the size average. These approximate expressions were compared with the numerical results based on the Mie scattering theory. Experimental results for isolated secretory granules, zymogen (dn approximately 800 nm) and chromaffin (dn approximately 400 nm) granules, were analyzed by use of the present formulation, and the dispersion in size distribution, sigma/dn = [(the mean of d2)/d2n - 1]1/2, was found to be about 0.2 for both types of granules.     

Phosphorylation and activation of calmodulin-sensitive cyclic nucleotide phosphodiesterase by a brain Ca2+, calmodulin-dependent protein kinase

A Ca2+, calmodulin-dependent protein kinase from rat brain with a MW of 640,000 phosphorylated calmodulin-sensitive phosphodiesterase from the brain cytosol. The Km of the enzyme for the phosphodiesterase was 5.0 microM and the Vmax was 212 nmol/mg/min. The amount of phosphate incorporated into the phosphodiesterase was 0.7 mol/mol subunit. Phosphorylation of the phosphodiesterase enhanced the enzyme activity by about 20% for hydrolysis of a higher concentration of cyclic AMP.     

Regulation of breathing during exercise

This paper reviewed in short neural and humoral factors which might be responsible for inducing exercise hyperpnea. As one of the neural factors afferent signals which arise in the exercising limbs and are transmitted via group III or IV high threshold sensory fibres were involved. The other neural factor is command signals originating in the central nervous system and being fed onto the respiratory center. Hypothalamic locomotor region is assumed to be a possible locus to integrate these peripheral and central neural signals. There are enough evidences to believe that humoral factors mediated via cardiac output is also essential for the hyperpnea. Changes in VCO2 is well correlated with those of VE in dynamic as well as in steady-state response. Oscillations in PaCO2 can be assumed to play a role to link metabolic CO2 changes to those in ventilation. Thus, no single factor can explain the whole process of exercise hyperpnea. Poon's optimization model may give a key to integrate complicated and coflicting experimental results in a unique concept.     

gamma-Ray-induced mutations in male germ cells of a recombination-defective strain (c3G) of Drosophila melanogaster

The gamma-ray (60Co) induction of the dumpy and Minute mutations, and the hyperploid exceptions during spermatogenesis was investigated by using a recombination-defective strain of Drosophila melanogaster, c3G and its wild-type strain, Oregon-R (c3G+). The results show that: (1) no essential difference exists in the response patterns for the dumpy and Minute mutations between these two strains; (2) however, a striking difference exists in the response pattern for the hyperploid exceptions. This is mainly due to an extraordinarily high sensitivity of the early spermatocytes of the c3G males to gamma-ray induction of these mutations. These findings possibly suggest that c3G gene may have some kind of role in the production of large structural changes by ionizing radiation, but not in the production of gene mutations.     

miR-33a-5p in small extracellular vesicles as non-invasive biomarker for oxaliplatin sensitivity in human colorectal cancer cells

microRNAs (miRNAs) contained in small extracellular vesicles (sEVs) are candidates for non-invasive biomarkers. Oxaliplatin (L-OHP) has been approved for advanced colorectal cancer (CRC) chemotherapy. However, the response to L-OHP differs among CRC patients. In addition, CRC cells often acquire the resistance to L-OHP. This study aimed at the prediction of L-OHP sensitivity by measuring extracellular miRNAs levels. Firstly, we compared intracellular miRNAs expressions in L-OHP-sensitive CRC cells (SW620 and HCT116 cells) with those in acquired and intrinsic L-OHP-resistant cells. In microarray and real-time RT-PCR analyses, the intracellular miR-33a-5p, miR-210–3p, and miR-224–5p expressions were lower in acquired and intrinsic L-OHP-resistant CRC cells than sensitive cells. Furthermore, in SW620 cells, L-OHP sensitivity was decreased by miR-33a-5p inhibitor. On the other hand, miR-210–3p or miR-224–5p inhibitor did not affect L-OHP sensitivity in SW620 cells. Secondly, the amount of miR-33a-5p, miR-210–3p, and miR-224–5p in sEVs was compared. The amount of miR-33a-5p and miR-210–3p in sEVs secreted from acquired and intrinsic L-OHP-resistant cells tended to be small. miR-224–5p was not detected in sEVs secreted from three types of CRC cells examined. To the best of our knowledge, this is the first study demonstrating that miR-33a-5p and/or miR-210–3p in sEVs would be candidates for biomarkers of L-OHP sensitivity. In particular, miR-33a-5p is a promising candidate because it would be directly involved in L-OHP sensitivity.