Selective deletion of ENTPD1/CD39 in macrophages exacerbates biliary fibrosis in a mouse model of sclerosing cholangitis

Purinergic Signalling - Purinergic signaling is important in the activation and differentiation of macrophages, which play divergent roles in the pathophysiology of liver fibrosis. The...     

Morphology and electrostatics play active role in neuronal differentiation processes on flexible conducting substrates

This commentary discusses and summarizes the key highlights of our recently reported work entitled “Neuronal Differentiation of Embryonic Stem Cell Derived Neuronal Progenitors Can Be Regulated by Stretchable Conducting Polymers.” The prospect of controlling the mechanical-rigidity and the surface conductance properties offers a unique combination for tailoring the growth and differentiation of neuronal cells. We emphasize the utility of transparent elastomeric substrates with coatings of electrically conducting polymer to realize the desired substrate-characteristics for cellular development processes. Our study showed that neuronal differentiation from ES cells is highly influenced by the specific substrates on which they are growing. Thus, our results provide a better strategy for regulated neuronal differentiation by using such functional conducting surfaces.     

The destruction by microwave radiation of bacterial endospores and amplification of the released DNA

Endospores from Bacillus megaterium NCIMB 7581, B. stearothermophilus NCIMB 8922, Clostridium sporogenes NCIMB 8053 and Thermoanaerobacterium thermosaccharolyticum NCIMB 9385 were subjected to varying regimes of microwave radiation under controlled conditions. The effects of this form of thermal excitation were studied in terms of morphological changes (light and electron microscopy) and also release of constituents (DNA and calcium ions) from the core of the spore. Spores which are highly resistant to conventional heating such as autoclaving were fragmented by microwaves, albeit only at a greater intensity than was required for spores of mesophilic species. Spores of B. sphaericus NCTC 9602 and of a mutant, which contains 30% of the dipicolinic acid (DPA) of the parent, showed identical profiles of disruption with respect to time and temperature. It is unlikely therefore that DPA plays any role in the thermal excitation of the core. The DNA liberated by microwaving spores was amplifiable by polymerase chain reaction; the rapid identification of spores in the food and pharmaceutical industries is thus possible using this approach.     

Molecular determination of van genes among clinical isolates of enterococci at a hospital setting

Vancomycin-resistant enterococci (VRE) poses a formidable challenge to public health due to its inherent resistance to multiple antibiotics coupled with the ability to transfer genetic determinants to dangerous pathogens like Methicillin-resistant Staphylococcus aureus (MRSA). The purpose of this study was to investigate the incidence of vancomycin resistance in enterococci among clinical isolates at a tertiary care military hospital in the eastern region of Saudi Arabia and to detect van genes using multiplex-PCR. Overall, 246 isolates of enterococci were collected from various clinical specimens. The isolates were identified, and antimicrobial susceptibility testing was done using the Vitek 2 system. Multiplex PCR was performed on the VRE isolates, thus identified to determine the van genes harbored. A total of 15 VRE were identified, of which 14 (93.3%) were Enterococcus faecium, and 1(6.7%) was Enterococcus casseliflavus with intrinsic vanC resistance. Of the 14 vancomycin-resistant Enterococcus faecium, 8 (57.1%) harbored vanB genes, while 6 (42.8%) harbored vanA genes. All the VRE were susceptible to linezolid and tigecycline. Our study detected a low prevalence (6.1%) of VRE among clinical isolates of enterococci and that the vanB gene predominates in such strains. Susceptibility profiles indicated that linezolid and tigecycline are still effective against these multidrug-resistant pathogens. Pus specimens yielded the highest percentage (53.3%) of isolates from which VRE was obtained, and this finding is novel among studies done in Saudi Arabia.     

Can lantana seeds be utilized in lamb rations?

Lantana seeds contain 70.6 g crude protein, 12.8 g ether extract, 103.1 g crude fibre, 761.0 g nitrogen-free extract, 52.5 g total ash, 8.4 g calcium and 2.5 g phosphorus/kg dry matter. The replacement, by lantana seeds, of 200 g maize/kg of concentrate mixture for lambs was studied in two experiments lasting 3–4 months. The crude protein concentration in the lantana ration was lower than in the maize, and significantly (P<0.01) so in the second experiment. In the first experiment, the digestibility and intakes of dietary crude protein (DCP) and total dietary nitrogen (TDN) of the lantana group were not significantly lower. In the second experiment, dry matter and crude protein digestibility and intakes of DCP and TDN of the lantana group were significantly (P<0.01) lower than the maize group. Even after adjustment for mean protein concentration in the diets, the intakes of DCP (P<0.01) and TDN (P<0.05) in the lantana group were significantly lower. In a repeat metabolic trial also, the adjusted intakes of both DCP and TDN (P<0.01) of the lantana group were significantly lower. In spite of the depression in feed utilization, the biochemical and haematological parameters of the blood of animals in the lantana group were within the normal range. The apparent non-toxicity of lantana seeds to lambs over long-term feeding trials calls for further work on their possible utilization as a feed ingredient.     

Ischemia reperfusion dysfunction changes model-estimated kinetics of myofilament interaction due to inotropic drugs in isolated hearts

Background  

The phase-space relationship between simultaneously measured myoplasmic [Ca²⁺] and isovolumetric left ventricular pressure (LVP) in guinea pig intact hearts is altered by ischemic and inotropic interventions. Our objective was to mathematically model this phase-space relationship between [Ca²⁺] and LVP with a focus on the changes in cross-bridge kinetics and myofilament Ca²⁺ sensitivity responsible for alterations in Ca²⁺-contraction coupling due to inotropic drugs in the presence and absence of ischemia reperfusion (IR) injury.     

Amplification of fluorescently labelled DNA within gram-positive and acid-fast bacteria.

Representative organisms from a variety of Gram-positive genera were subjected to varying regimes in order to optimise the intracellular amplification of DNA. The bacteria were subjected to treatments with paraformaldehyde, muramidases and mild acid hydrolysis to discover which regime made each organism permeable to the amplification reagents yet allowed retention of the fluorescein-labelled amplified products within the cell. Scanning electron micrographs were used to corroborate the effectiveness of the treatments, as seen by fluorescent photomicrographs, with the damage caused to the bacterial walls. A combination of mutanolysin and lysozyme was found most effective for Bacillus cereus, whereas permeabilisation of Streptomyces coelicolor, Lactococcus lactis and Clostridium sporogenes was most effective when exposed to lysozyme only. Surprisingly, direct amplification with no pre-treatment gave the brightest fluorescence in Mycobacterium phlei. Comparing the techniques of whole cell PCR, primed in situ labelling (PRINS), and cycle PRINS showed that under the conditions used the strongest intensity of fluorescence was obtained with in situ PCR; only L. lactis and M. phlei produced signals with cycle PRINS, fluorescence was not seen for any of the organisms with PRINS.