11 research outputs found
BMP signals and the transcriptional repressor BLIMP1 during germline segregation in the mammalian embryo
Molecular factors and tissue compartments involved in the foundation of the mammalian germline have been mainly described in the mouse so far. To find mechanisms applicable to mammals in general, we analyzed temporal and spatial expression patterns of the transcriptional repressor BLIMP1 (also known as PRDM1) and the signaling molecules BMP2 and BMP4 in perigastrulation and early neurulation embryos of the rabbit using whole-mount in situ hybridization and high-resolution light microscopy. Both BMP2 and BMP4 are expressed in annular domains at the boundary of the embryonic disc, whichâin contrast to the situation in the mouseâpartly belong to intraembryonic tissues. While BMP2 expression begins at (pregastrulation) stage 1 in the hypoblast, BMP4 expression commencesâdistinctly delayed compared to the mouseâdiffusely at (pregastrulation) stage 2; from stage 3 onwards, BMP4 is expressed peripherally in hypoblast and epiblast and in the mesoderm at the posterior pole of the embryonic disc. BLIMP1 expression begins throughout the hypoblast at stage 1 and emerges in single primordial germ cell (PGC) precursors in the posterior epiblast at stage 2 and then in single mesoderm cells at positions identical to those identified by PGC-specific antibodies. These expression patterns suggest that function and chronology of factors involved in germline segregation are similar in mouse and rabbit, but higher temporal and spatial resolution offered by the rabbit demonstrates a variable role of bone morphogenetic proteins and makes âblimpingâ a candidate case for lateral inhibition without the need for an allantoic germ cell niche
Detection of Sindbis and Inkoo Virus RNA in Genetically Typed Mosquito Larvae Sampled in Northern Sweden
Physical changes of ÎČ-sitosterol crystals in oily suspensions during heating
The aim of this research was to describe the thermal behavior of ÎČ-sitosterol crystals in oil-suspensions with a focus on the role of water during heating. The suspensions were prepared by recrystallization in order to achieve a microcrystalline particle size. The structural changes together with the mechanical properties of the suspensions during heating were studied by using variable temperature X-ray powder diffractometry (VT-XRPD), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). Hydrated ÎČ-sitosterol crystals in an oil-suspension, dehydrated, despite the composition of the suspensions, at low temperatures. At high ÎČ-sitosterol concentration, the monohydrate crystal form changed partially to a hemihydrated form, and when only a small amount of water was initially incorporated, the hemihydrate crystal form dehydrated to a mostly anhydrate crystal form. The released water, which was immiscible in the surrounding oil, caused the recrystallization of hydrated ÎČ-sitosterol during cooling. This procedure indicated a reversible dehydration process. Structural and thermal analysis of ÎČ-sitosterol crystals in suspensions, together with mechanical analysis made it possible to understand various physical changes during heating
Rapid killing of Capnocytophaga canimorsus and Capnocytophaga cynodegmi by human whole blood and serum is mediated via the complement system
Quantitative measurement of indomethacin crystallinity in indomethacin-silica gel binary system using differential scanning calorimetry and X-ray powder diffractometry
Pharmaceutical solid-state characterisation techniques
The solid state of a pharmaceutical material impacts on every aspect of its formulation; from solubility and thermodynamic stability to tabletability and flowability. Due to this fundamental connection characterising the solid state is key to providing the information necessary to reduce possible future manufacturing or formulation issues, which critically cuts drug product development costs and time. In this chapter a summary of the importance of the solid state and solid form screening in the pharmaceutical industry is presented. This is followed by an introduction to some of the solid state characterisation techniques routinely utilised in the pharmaceutical industry together with examples of the information provided by each