46480527
Macrophage cholesterol homeostasis and metabolic diseases: critical role of cholesteryl ester mobilization
Atherogenic dyslipidemia, including low HDL levels, is the major contributor of residual risk of cardiovascular disease that remains even after aggressive statin therapy to reduce LDL-cholesterol. Currently, distinction is not made between HDL-cholesterol and HDL, which is a lipoprotein consisting of several proteins and a core containing cholesteryl esters (CEs). The importance of assessing HDL functionality, specifically its role in facilitating cholesterol efflux from foam cells, is relevant to atherogenesis. Since HDLs can only remove unesterified cholesterol from macrophages while cholesterol is stored as CEs within foam cells, intracellular CE hydrolysis by CE hydrolase is vital. Reduction in macrophage lipid burden not only attenuates atherosclerosis but also reduces inflammation and linked pathologies such as Type 2 diabetes and chronic kidney disease. Targeting reduction in macrophage CE levels and focusing on enhancing cholesterol flux from peripheral tissues to liver for final elimination is proposed.
25354783
Molecular cloning and expression of rat hepatic neutral cholesteryl ester hydrolase.
The 1923 bp cDNA for rat hepatic cholesteryl ester hydrolase (CEH) was cloned by screening a lambda gt11 expression library with an oligonucleotide containing the consensus active site sequence for cholesteryl esterases. Expression of a fusion protein, cross-reacting with antibody to the purified liver CEH, was demonstrated by Western blot analysis. The cDNA was sequenced and found to have only 44% homology with pancreatic CEH. Although unique, the cDNA sequence exhibited much greater overall homology with liver carboxylesterases, in both coding and 5'/3' non-coding regions. In Northern blot analysis, the cDNA hybridized with a single band from liver mRNA but not with pancreatic mRNA. The 1.7 kb coding sequence, predicting a 62 kDa protein, was cloned into an Escherichia coli expression system with an inducible promoter and into COS-7 cells. Both expression systems produced a protein which comigrated with liver CEH (66 kDa) on SDS-PAGE and immunoreacted with antibodies to liver CEH on Western blots. Whereas the prokaryotic system produced an inactive protein, expression in COS-7 cells was accompanied by a 5-fold increase in CEH activity and a corresponding increase in immunoreactive protein.
24936933
Mechanism of intestinal entry of infectious prion protein in the pathogenesis of variant Creutzfeldt-Jakob disease.
The pathogenesis of variant Creutzfeldt-Jakob disease (vCJD) is most likely to be dependent on intestinal entry of orally ingested infectious prion proteins, though tonsils or other oral portals of entry are possible. The exact route of entry of infectious prion proteins is uncertain but receptors for prion proteins such as laminin receptor precursor (LRP) may be expressed on intestinal brush border. Cellular prion protein (PrP(c)) is expressed on intestinal enteric nervous system and is separated by a single layer of epithelial cells from ingested infectious prion proteins. Intestinal M cells in the Peyer's patches may also transcytose prion proteins which may be transported to the lymphatic system by migrating dendritic cells underlying the M cells. The relative importance of the several potential portals of intestinal entry of infectious prion proteins is uncertain but may determine susceptibility of the population and also potential preventive strategies.
24414715
The Papworth BiVent tube: a new device for lung isolation.
Provision of one lung ventilation can be technically challenging, particularly for anaesthetists who are only occasionally required to isolate one lung from the other. A new double lumen endotracheal tube, the Papworth BiVent Tube, has been designed to enable rapid and reliable lung isolation using any bronchus blocker without the need for fibreoptic endoscopic guidance. In this study, an airway-training manikin was used to assess ease of tracheal intubation and lung isolation using the Papworth BiVent tube. Ease of intubation was compared to a single lumen endotracheal tube and a conventional double lumen endobronchial tube. Ease of lung isolation when using a bronchus blocker was compared to a single lumen tube combined with a bronchial blocker. Tracheal intubation using the Papworth BiVent tube was found to be easier than when using a conventional double lumen endobronchial tube. Lung isolation using the Papworth BiVent tube used in combination with a bronchus blocker was achieved more reliably and rapidly than when using a single lumen tube and bronchus blocker.
25372281
Progress in development of vaccine against Hyalomma anatolicum anatolicum-Indian scenario.
Hyalomma anatolicum anatolicum, a three host tick vector transmitting the causative agent of bovine tropical theileriosis, is widely distributed throughout India. As a component of integrated control measures against the tick vector, attempts have been made to identify candidate protein molecules for development of an anti-tick vaccine in the different stages of this tick species. By strategic methods of isolation of the targeted molecules using affinity purification of proteins showing reactivity with immunoglobulins of animals previously immunized with different sources of tick antigen, six proteins were isolated in a significantly pure form. The recovery percentage of the candidate proteins was very low in the range of 1.8-8.0%. The protective potentiality of the antigens was tested in immunization and challenge trials and maximum potential was observed in the proteins isolated from total larval extracts, nymphal extracts and in larval glycoprotein. One of the antigens with a molecular weight of 37kDa isolated from larvae of H. a. anatolicum was found to have some adverse effect on development of Theileria annulata in the vector tick. The progress in the development of immunoprophylactic measures against H. a. anatolicum is discussed.
36570389
Elimination of Mercury and Organomercurials by Nitrogen-Fixing Bacteria
Bacteria isolated from mercury-polluted environments are often resistant to mercuric ions (Hg{sup 2+}) and organomercurials. Plasmids determining mercury resistance have been well characterized in gram-negative system. However, in Staphylococcus aureus mercury resistance has been found to be chromosomally determined. The known mechanism of bacterial Hg{sup 2+}-resistance is detoxification of the toxic Hg{sup 2+} by its enzymatic transformation by mercuric reductase to Hg (o). Organomercurial lyase mediates the degradation of organomercurial compounds to Hg{sup 2+}. Mercury and organomercurial resistances have been studied in different bacterial genera. There is little information on Hg-resistance in N{sub 2}-fixing soil bacteria, however, in many developing countries, including India, mercury pollution is still a problem because Hg-based pesticides and fungicides are still used routinely as seed-dressers in agriculture to control soil-borne and seed-borne fungal diseases. Volatilization of Hg from laboratory media by mercury-resistant bacteria containing low levels of mercury has been reported by several workers. It is interesting to note that N{sub 2}-fixing, Hg-resistant soil isolates could volatilize Hg from medium containing very high amounts of HgCl{sub 2}. In the present paper we report the volatilization patterns of five N{sub 2}-fixing bacterial strains, the effect of different inducers on mercuric reductase, and the pattern of substratemore » utilization by organomercurial lyase. In the presence of a low concentration of HgCl{sub 2}. enzymatic detoxification is sufficient to combat the adverse situation created by the presence of Hg{sup 2+} ions. In the presence of a high concentration of HgCl{sub 2}, intracellular sequestration by Hg{sup 2+} binding components may play an additional role in counteracting Hg-toxicity.« less
6526989
Isolation and characterization of superdormant spores of Bacillus species.
Superdormant spores of Bacillus subtilis and Bacillus megaterium were isolated in 4 to 12% yields following germination with high nutrient levels that activated one or two germinant receptors. These superdormant spores did not germinate with the initial nutrients or those that stimulated other germinant receptors, and the superdormant spores' defect was not genetic. The superdormant spores did, however, germinate with Ca(2+)-dipicolinic acid or dodecylamine. Although these superdormant spores did not germinate with high levels of nutrients that activated one or two nutrient germinant receptors, they germinated with nutrient mixtures that activated more receptors, and using high levels of nutrient mixtures activating more germinant receptors decreased superdormant spore yields. The use of moderate nutrient levels to isolate superdormant spores increased their yields; the resultant spores germinated poorly with the initial moderate nutrient concentrations, but they germinated well with high nutrient concentrations. These findings suggest that the levels of superdormant spores in populations depend on the germination conditions used, with fewer superdormant spores isolated when better germination conditions are used. These findings further suggest that superdormant spores require an increased signal for triggering spore germination compared to most spores in populations. One factor determining whether a spore is superdormant is its level of germinant receptors, since spore populations with higher levels of germinant receptors yielded lower levels of superdormant spores. A second important factor may be heat activation of spore populations, since yields of superdormant spores from non-heat-activated spore populations were higher than those from optimally activated spores.