A study of ethanol tolerance in yeast

The ethanol tolerance of yeast and other microorganisms has remained a controversial area despite the many years of study. The complex inhibition mechanism of ethanol and the lack of a universally accepted definition and method to measure ethanol tolerance have been prime reasons for the controversy. A number of factors such as plasma membrane composition, media composition, mode of substrate feeding, osmotic pressure, temperature, intracellular ethanol accumulation, and byproduct formation have been shown to influence the ethanol tolerance of yeast. Media composition was found to have a profound effect upon the ability of a yeast strain to ferment concentrated substrates (high osmotic pressure) and to ferment at higher temperatures. Supplementation with peptone-yeast extract, magnesium, or potassium salts has a significant and positive effect upon overall fermentation rates. An intracellular accumulation of ethanol was observed during the early stages of fermentation. As fermentation proceeds, the intracellular and extracellular ethanol concentrations become similar. In addition, increases in osmotic pressure are associated with increased intracellular accumulation of ethanol. However, it was observed that nutrient limitation, not increased intracellular accumulation of ethanol, is responsible to some extent for the decreases in growth and fermentation activity of yeast cells at higher osmotic pressure and temperature.     

Phosphatase Inhibitors Function as Novel,Broad Spectrum Botulinum Neurotoxin Antagonists in Mouse and Human Embryonic Stem Cell-Derived Motor Neuron-Based Assays

There is an urgent need to develop novel treatments to counter Botulinum neurotoxin (BoNT) poisoning. Currently, the majority of BoNT drug development efforts focus on directly inhibiting the proteolytic components of BoNT, i.e. light chains (LC). Although this is a rational approach, previous research has shown that LCs are extremely difficult drug targets and that inhibiting multi-serotype BoNTs with a single LC inhibitor may not be feasible. An alternative approach would target neuronal pathways involved in intoxication/recovery, rather than the LC itself. Phosphorylation-related mechanisms have been implicated in the intoxication pathway(s) of BoNTs. However, the effects of phosphatase inhibitors upon BoNT activity in the physiological target of BoNTs, i.e. motor neurons, have not been investigated. In this study, a small library of phosphatase inhibitors was screened for BoNT antagonism in the context of mouse embryonic stem cell-derived motor neurons (ES-MNs). Four inhibitors were found to function as BoNT/A antagonists. Subsequently, we confirmed that these inhibitors protect against BoNT/A in a dose-dependent manner in human ES-MNs. Additionally, these compounds provide protection when administered in post-intoxication scenario. Importantly, the inhibitors were also effective against BoNT serotypes B and E. To the best of our knowledge, this is the first study showing phosphatase inhibitors as broad-spectrum BoNT antagonists.     

Curcumin mediated epigenetic modulation inhibits TREM-1 expression in response to lipopolysaccharide

Triggering receptor expressed on myeloid cells 1 (TREM-1) is a member of the immunoglobulin superfamily expressed on macrophage and neutrophils and is emerging as a potent amplifier of TLR initiated inflammatory responses. Blockade of TREM-1 improves survival in animal models of sepsis. In this study, we show that curcumin or diferuloylmethane, a yellow pigment present in turmeric, a major ingredient of curry spice inhibited the expression of TREM-1 in vitro in primary bone marrow derived macrophages and in vivo in lungs of mice with sepsis. Chromatin immunoprecipitation assay confirmed that curcumin inhibits the binding of p65 to TREM-1 promoter in response to LPS. Further we show that curcumin inhibited p300 activity in the TREM-1 promoter region leading to hypoacetylation of histone 3 and 4 in the lysine residues. Inhibition of TREM-1 by curcumin is oxidant independent. These studies are the first report to define a detailed molecular mechanism by which curcumin exerts anti-inflammatory effects through regulation of TREM-1 gene activity and provide additional mechanistic insights into the anti-inflammatory effect of curcumin.     

Developmental and neurobehavioural toxicity study of arsenic on rats following gestational exposure

To characterize developmental and behavioral alterations induced by arsenic exposure, Albino rats were exposed to arsenic (0, 1.5, 3.0 and 4.5 mg/kg/day/po) from gestation day 8 to till parturition and the offspring were observed over the first 3 postnatal weeks, until they were weaned on post-natal day (PND) 21. Once the pups were delivered (PND0), the treatment was discontinued. All pups were assessed for physical development, reflex development, strength and motor coordination from standard neurobehavioural developmental test batteries beginning on PND1. Gestational administration of arsenic at tested dose levels, showed no significant changes in the day of appearance of eye opening, startle reflex, negative geotaxis and spontaneous alteration performance in comparison to the control group. The number of live fetuses, mean fetal body weight and percentages of resorptions or malformations per litter were not affected by arsenic exposure. No treatment-related malformations or developmental variations were noted at any exposure level, suggesting that arsenic exposure at this dose level did not adversely affect behavioural endpoints of developmental toxicity.     

Multiphase hemodynamic simulation of pulsatile flow in a coronary artery

A multiphase transient non-Newtonian three-dimensional (3-D) computational fluid dynamics (CFD) simulation has been performed for pulsatile hemodynamics in an idealized curved section of a human coronary artery. We present the first prediction, to the authors' knowledge, of particulate buildup on the inside curvature using the multiphase theory of dense suspension hemodynamics. In this study, the particulates are red blood cells (RBCs). The location of RBC buildup on the inside curvature correlates with lower wall shear stress (WSS) relative to the outside curvature. These predictions provide insight into how blood-borne particulates interact with artery walls and hence, have relevance for understanding atherogenesis since clinical observations show that atherosclerotic plaques generally form on the inside curvatures of arteries. The buildup of RBCs on the inside curvature is driven by the secondary flow and higher residence times. The higher viscosity in the central portion of the curved vessel tends to block their flow, causing them to migrate preferentially through the boundary layer. The reason for this is the nearly neutrally buoyant nature of the dense two-phase hemodynamic flow. The two-phase non-Newtonian viscosity model predicts greater shear thinning than the single-phase non-Newtonian model. Consequently, the secondary flow induced in the curvature is weaker. The waveforms for computed hemodynamic parameters, such as hematocrit, WSS, and viscosity, follow the prescribed inlet velocity waveforms. The lower oscillatory WSS produced on the inside curvature has implications for understanding thickening of the intimal layer.     

Evaluation of basic,heterocyclic ring systems as templates for use as potassium competitive acid blockers (pCABs)

A variety of basic, heterocyclic templates has been reported as potassium-competitive, acid pump antagonists. Herein, we report a comparison of potencies of these templates and others to establish which offers the best start point for further systematic optimisation. Modifications were carried out to improve the developability profile of the more potent 1H-pyrrolo[2,3-c]pyridine template, affording molecules with improved overall in vitro characteristics versus the reported clinical candidate AR-H047108, and comparable to the clinically efficacious AZD-0865.     

Differences in Infection Rates by Surgical Approach in Total Hip Arthroplasty and Patient Sex: A Systematic Review

BackgroundThere exists conflicting data that patient sex may influence complication and revision rates when undergoing total hip arthroplasty (THA), specifically when comparing different surgical approaches. Differences in body fat or muscular distribution are proposed mechanisms, but these are poorly understood and not well described in current literature.MethodsA systematic review of the literature was conducted from PubMed, Embase, and Web of Science from inception of the database through September 15, 2020. Studies were included if they included patients undergoing primary elective unilateral THA, delineated infections by surgical approach, and delineated infections by patient sex. Basic science, cadaveric, and animal studies were excluded as were case reports. Two authors screened abstracts and then extracted data from the full text article.ResultsThree studies, including 1,694 patients undergoing 1,811 THA were included. 80 infections were included. No study reported a statistically significant difference in infection risk by patient sex or surgical approach, though there was substantial heterogeneity in study design, approach, and analysis.ConclusionLimited data suggests no relationship between sexes across surgical approaches for infection rates. However, poor reporting and small sample sizes preclude definitive conclusions from being drawn. Future studies should emphasize reporting differences in outcomes by patient sex to better elucidate differences, if any, in adverse outcomes between sexes following THA across surgical approaches. Level of Evidence: IV     

Management of craniosynostosis

Learning Objectives: After studying this article, the participant should be able to: 1. Review the etiopathogenesis of craniosynostosis and craniofacial anomalies. 2. Develop a basic understanding of the clinical manifestations and diagnosis of craniofacial anomalies. 3. Describe the surgical principles of managing craniosynostosis and craniofacial anomalies.Craniosynostosis, or the premature closure of calvarial sutures, results in deformed calvaria at birth. Although the etiology of craniosynostosis is currently unknown, animal experiments and a recent interest in molecular biology point toward interplay between the dura and the underlying brain. This interaction occurs by means of a local alteration in the expression of transforming growth factor, MSX2, fibroblast growth factor receptor, and TWIST. The fused suture restricts growth of the calvaria, thus leading to a characteristic deformation, each associated with a different type of craniosynostosis. Uncorrected craniosynostosis leads to a continuing progression of the deformity, and in some cases, an elevation of intracranial pressure. Clinical examination should include not only an examination of the skull but also a general examination to rule out the craniofacial syndromes that accompany craniosynostosis. Because deformational plagiocephaly, or plagiocephaly without synostosis, occurs secondary to sleeping in the supine position during the early perinatal period, the physician should be aware of this abnormality. Treatment for deformational plagiocephaly is conservative when compared with treatment for craniosynostosis, which requires surgery. Appropriate investigations should include genetic screening, radiologic examination with a computerized tomographic scan, and neurodevelopmental analysis. Surgical intervention should be performed during infancy, preferably in the first 6 months of postnatal life, to prevent the further progression of the deformity and possible complications associated with increased intracranial pressure. The principles of surgical intervention are not only to excise the fused suture but also to attempt to normalize the calvarial shape. Long-term follow-up is critical to determine the effect of the surgical outcome.