Chromosome structure and behaviour in Bursaphelenchus xylophilus (Nematoda: Parasitaphelenchidae) germ cells and early embryo

Chromosome structure and behaviour in both meiosis of the germ cells and mitosis of the embryo from fertilisation to the two-cell stage in Bursaphelenchus xylophilus were examined by DAPI staining and three-dimensional reconstruction of serial-section images from confocal laser-scanning microscopy. By this method, each chromosome’s shape and behaviour were clearly visible in early embryogenesis from fertilisation through the formation and fusion of the male and female pronuclei to the first mitotic division. The male pronucleus was bigger than that of the female, although the oocyte is larger and richer in nutrients than the sperm. From the shape of the separating chromosomes at anaphase, the mitotic chromosomes appeared to be polycentric or holocentric rather than monocentric. Each chromosome was clearly distinguishable in the male and female germ cells, pronuclei of the one-cell stage embryo, and the early embryonic nuclei. The haploid number of chromosomes (N) was six (2n = 12), and all chromosomes appeared similar. The chromosome pair containing the ribosomal RNA-coding site was visualised by fluorescence in situ hybridisation. Unlike the sex determination system in Caenorhabditis elegans (XX in hermaphrodite and XO in male), the system for B. xylophilus may consist of an XX female and an XY male

Pore properties of hierarchically porous carbon monoliths with high surface area obtained from bridged polysilsesquioxanes

Hierarchically porous carbon monoliths with high specific surface area have been prepared via a nano-phase extraction technique from carbon/silica composites which had been prepared from arylene-bridged polysilsesquioxanes. The nano-sized silica phase developed in the composite has been removed to increase micropores, resulting in a similar effect to thermal activation of carbons. The resultant carbons are expected to possess homogeneously distributed micropores. Here we report the changes of the pore characteristics through the synthesis process by the nitrogen adsorption–desorption method and mercury porosimetry. In particular, the growth of silica phase in carbon/silica composites at different temperatures has been characterized by the micropore analysis using the Horváth-Kawazoe method

Transmission of bacterial infections to healthcare workers during intubation and respiratory care of patients with severe pneumonia

Exposure of healthcare workers to patients with rapidly fatal infections invariably raises concerns regarding the risk of occupational acquisition. We describe acquisition of Streptococcus pyogenes by 2 nurses from a patient with fatal pneumonia and review previously reported cases of transmission of bacterial pathogens from patients with pneumonia to healthcare workers

Transforming growth factor beta family expression at the bovine feto-maternal interface

<p>Abstract</p> <p>Background</p> <p>Endometrial remodelling is necessary for implantation in all mammalian species. The TGF beta super-family plays a crucial role in this event in humans and mice. However, the role of TGF beta super-family members during implantation is still unclear in ruminants. In the present study, the spacio-temporal expression of TGF beta super-family members including activin was explored in bovine trophoblasts and endometrial tissue during the peri-implantation period in order to elucidate whether it is essential for promoting cell proliferation at the implantation site.</p> <p>Methods</p> <p>Gene expression in the fetal membrane and endometrium of the gravid and non-gravid horn around Day 35 of gestation were analyzed with a custom-made oligo-microarray in cattle. The expression of activin and its related genes was also analyzed with quantitative RT-PCR. Activin-like activity in trophoblastic tissue and BT-1 cells was examined using a fibroblast cell proliferation test and Western blotting.</p> <p>Results</p> <p>The expression of various TGF beta super-family related genes including activin was detected in trophoblasts and the endometrium in cattle. The most intensive activin expression was found in the gravid horn endometrium, and rather intense expression was detected in the non-gravid trophoblastic tissue. Extracts from the fetal membrane including trophoblasts and purified activin both stimulated fibroblast proliferation effectively, and activin was immunologically detected in BT-1 cells, which have trophoblastic features.</p> <p>Conclusions</p> <p>Specific expression of the activin gene (gene name: inhibin beta A) was found in the gravid horn endometrium during peri-implantation. An activin-like molecule, which was derived from the endometrium and trophoblasts, stimulated the proliferation of fibroblast cells. These results suggested that as in other species, the activity of TGF beta super-family members including activin-like molecules plays a pivotal role in endometrial remodelling, which is an essential process in implantation and placentogenesis during the peri-implantation period in cattle.</p

High resolution carbon isotope stratigraphy across the Cenomaian/Turonian boundary in the Tappu area, Hokkaido, Japan : correlation with world reference sections

Received March 2, 2010 and accepted in revised from March 11, 201

Development of Superior Heat Resistant Cu-Si Alloys Dispersed with Fine Mo5Si3 Particles

Proceedings of 17th International Federation for Heat Treatment and Surface Engineering Congress (IFHTSE 2008), 27-30 October 2008, Kobe, Japa

Adenosine receptors in the isolated rabbit afferent and efferent arterioles

Adenosine has been noted as one of the endogenous modulators of renal hemodynamics. Renal hemodynamic was mainly regulated by two resistance vessels, the afferent arteriole and efferent arteriole. However, there is still no consensus as to the intrarenal vascular action site of adenosine. In this study, we examined the direct effect of adenosine on the isolated microperfused rabbit afferent and efferent arterioles. Adenosine decreased the lumen diameter of microperfused afferent arterioles dose-dependently (Control : 14.35±0.97μm, adenosine 10-7M : 12.73±1.40μm, 10-6M : 8.18±1.21μm, 10-5M : 4.33±1.16μm, n=6). Adenosine increased the lumen diameter of adenosine A1 antagonist, 8-(normantan-3-yl)-1,3-dipropylxanthin (KW-3902), pretreated-microperfused afferent arterioles preconstricted by norepinephrine. Pretreatment with adenosine A2 antagonist, (E)-1,3,-dipropyl-8-(3,4-dimethoxystyryl)-7-methylxanthin (KF-7837), enhanced adenosine induced-afferent arteriolar vasoconstrictor effect. Adenosine did not change the lumen diameter of microperfused efferent arterioles, but adenosine increased the lumen diameter of norepinephrine preconstricted-microperfused efferent arterioles. The present data suggest that the afferent arterioles possesses both adenosine A1 and A2 receptors and the efferent arterioles possesses predominantly adenosine A2 receptors at least in the rabbit kidney