Interaction of sodium dodecyl sulfate and of non-ionic detergents with S-carboxyamidomethyl-k-casein

Sodium dodecyl sulfate binds to S-carboxyamidomethyl-k-casein in a highly cooperative manner at a concentration near the critical micelle concentration, showing a strong dependence on ionic strength. The maximum number of sodium dodecyl sulfate molecules bound is attained above the critical micelle concentration, and is very close to the micelle aggregation number in the absence of protein. The binding sites on the protein for sodium dodecyl sulfate are localized mainly on para-k-casein part, which is a hydrophobic fragment of k-casein produced by rennin attack. The mode of the action of sodium dodecyl sulfate on S-carboxyamidomethyl-k-casein resembles that of several integral membrane proteins, rather than of water soluble proteins. On considering possible situations, it is suggested that the unusual interaction of S-carboxyamidomethyl-k-casein with sodium dodecyl sulfate is responsible for an anomalous migration of reduced k-casein observed in sodium dodecyl sulfate polyacrylamide gel electrophoresis. Further, the suggestion was made by the binding studies of sodium dodecyl sulfate and non-ionic detergents that the sites which were involved in self-association of S-carboxyamidomethyl-k-casein participated in the binding sites of detergents.     

High Levels of the Cleaved Form of Galectin-9 and Osteopontin in the Plasma Are Associated with Inflammatory Markers That Reflect the Severity of COVID-19 Pneumonia

Numbers of patients with coronavirus disease 2019 (COVID-19) have increased rapidly worldwide. Plasma levels of full-length galectin-9 (FL-Gal9) and osteopontin (FL-OPN) as well as their truncated forms (Tr-Gal9, Ud-OPN, respectively), are representative inflammatory biomarkers. Here, we measured FL-Gal9, FL-OPN, Tr-Gal9, and Ud-OPN in 94 plasma samples obtained from 23 COVID-19-infected patients with mild clinical symptoms (CV), 25 COVID-19 patients associated with pneumonia (CP), and 14 patients with bacterial infection (ID). The four proteins were significantly elevated in the CP group when compared with healthy individuals. ROC analysis between the CV and CP groups showed that C-reactive protein had the highest ability to differentiate, followed by Tr-Gal9 and ferritin. Spearman’s correlation analysis showed that Tr-Gal9 and Ud-OPN but not FL-Gal9 and FL-OPN, had a significant association with laboratory markers for lung function, inflammation, coagulopathy, and kidney function in CP patients. CP patients treated with tocilizumab had reduced levels of FL-Gal9, Tr-Gal9, and Ud-OPN. It was suggested that OPN is cleaved by interleukin-6-dependent proteases. These findings suggest that the cleaved forms of OPN and galectin-9 can be used to monitor the severity of pathological inflammation and the therapeutic effects of tocilizumab in CP patients.     

Stimulation of THP-1 Macrophages with LPS Increased the Production of Osteopontin-Encapsulating Exosome

Osteopontin (OPN) mediates bone remodeling and tissue debridement. The OPN protein is cleaved, but it is unclear how full-length (FL)-OPN or its cleaved form perform their biological activities in target cells. We, therefore, performed the molecular characterization of OPN in exosomes (Exo). The Exo were isolated from lipopolysaccharide (LPS)-stimulated phorbol 12-myristate 13-acetate (PMA)-differentiated THP-1 macrophages. The Exo were also isolated from PMA-differentiated THP-1 macrophages. The Exo were identified using the qNano multiple analyzer (diameter 59–315 nm) and western blotting with a CD9 antibody. LPS-stimulated cells produced more particles than non-stimulated cells. The presence of the FL or the cleaved form of OPN was confirmed using western blot analysis. A mixture of FL and cleaved OPN was also measured using an ELISA system (Ud-OPN) and their presence in the Exo was confirmed. Ud/FL ratios became low after LPS stimulation, indicating the enhanced encapsulation of FL-OPN in the Exo by LPS. These findings suggest that LPS stimulation of human macrophages facilitates the synthesis of FL-OPN, which is cleaved in cells or the Exo after release. These findings indicate that Exo is a suitable vehicle to transfer OPN to the target cells.     

Conditionals,Counterfactuals, and Rational Reasoning: An Experimental Study on Basic Principles

We present a unified approach for investigating rational reasoning about basic argument forms involving indicative conditionals, counterfactuals, and basic quantified statements within coherence-based probability logic. After introducing the rationality framework, we present an interactive view on the relation between normative and empirical work. Then, we report a new experiment which shows that people interpret indicative conditionals and counterfactuals by coherent conditional probability assertions and negate conditionals by negating their consequents. The data support the conditional probability interpretation of conditionals and the narrow-scope reading of the negation of conditionals. Finally, we argue that coherent conditional probabilities are important for probabilistic analyses of conditionals, nonmonotonic reasoning, quantified statements, and paradoxes.     

Evaluation of Lipophilic Antioxidant Efficacy in Vivo by the Biomarkers Hydroxyoctadecadienoic Acid and Isoprostane

The evaluation of antioxidant activity in vivo is difficult. In this study, the effects of dietary natural and synthetic antioxidants on the lipid peroxidation in mice were assessed using a biomarker, total hydroxyoctadecadienoic acid (tHODE). Biological samples such as plasma, erythrocytes, and tissues were first reduced and then saponified to convert various oxidation products of linoleates to tHODE. Subsequently, the absolute concentration of tHODE and its stereoisomer ratio, [9- and 13-(Z,E)-HODE)/[9- and 13-(E,E)-HODE], which is a measure of the hydrogen donor capacity of antioxidants, were determined by gas chromatography–mass spectrometry (GC–MS) analyses. These were then compared with total 8-iso-prostaglandin F_2α (t8-iso-PGF_2α) which was also assessed after reduction and saponification. Remarkable increases in tHODE and t8-iso-PGF_2α levels were observed in the plasma, erythrocytes, liver, and brain of mice that were fed an α-tocopherol (αT)-stripped (E-free) diet for 1 month when compared with those of mice that were fed a standard diet (αT = 0.002 wt%). When mice were fed for 1 month on an E-free diet supplemented with a lipophilic antioxidant (0.04 wt%), namely, αT, α-tocotrienol (αT3), γ-tocopherol (γT), or 2,3-dihydro-5-hydroxy-4,6-di-tert-butyl-2,2-dipentylbenzofuran (BO-653), a potent synthetic antioxidant, the increases of tHODE and t8-iso-PGF_2α in the plasma, erythrocytes, liver, and brain were suppressed to the levels lower than those of mice fed a standard diet. The (Z,E/E,E) HODE ratio was decreased in the plasma and erythrocytes of mice fed the E-free diet when compared with that in mice fed the standard diet. This stereo-isomeric ratio was significantly recovered by the addition of αT and BO-653. These results show that the tHODE level and the (Z,E/E,E) HODE ratio are useful biomarkers for the assessment of antioxidant capacity in vivo and that the antioxidant capacity decreased in the order: BO-653 > αT3 ≧ αT, γT, as assessed by tHODE levels from blood, liver, and brain.     

Corrosion and protection of carbon steel in low enthalpy geothermal fluids. The case of SOUSAKI IN Greece

This experimental work is aimed at evaluating first, the effect of a solution simulating the geothermal fluid of the field in Sousaki, New Korinthia, on the corrosion of bare steel, and, second, the protective performance that certain combinations of organic coatings provide. This evaluation resulted from corrosion potential measurements, mass loss measurements, corrosion rate estimates by the Tafel method, and visual ranking of the degree of rusting and blistering. Six combinations of organic coatings were tested. Four of them consisted of water-based paints as primer, as well as intermediate and topcoat. Of the two remaining combinations, the first comprised a water-based primer, including dispersed tannin and a two-component epoxy resin topcoat, while the second consisted of a two-component acrylic primer, containing chromate pigments and the same epoxy resin topcoat as above. All coating combinations tested exhibited protective performance. The results of the water-based coatings were less satisfactory than those of the two combinations containing the epoxy resin topcoat.     

Determination of Carbohydrate‐Binding Preferences of Human Galectins with Carbohydrate Microarrays

Galectins are a class of carbohydrate‐binding proteins named for their galactose‐binding preference and are involved in a host of processes ranging from homeostasis of organisms to immune responses. As a first step towards correlating the carbohydrate‐binding preferences of the different galectins with their biological functions, we determined carbohydrate recognition fine‐specificities of galectins with the aid of carbohydrate microarrays. A focused set of oligosaccharides considered relevant to galectins was prepared by chemical synthesis. Structure–activity relationships for galectin–sugar interactions were determined, and these helped in the establishment of redundant and specific galectin actions by comparison of binding preferences. Distinct glycosylations on the basic lactosyl motifs proved to be key to galectin binding regulation—and therefore galectin action—as either high‐affinity ligands are produced or binding is blocked. High‐affinity ligands such as the blood group antigens that presumably mediate particular functions were identified.     

Establishment of long-term preservation for dimethyl sulfide by the solid-phase microextraction method

Dimethyl sulfide (DMS) derived from marine biological activity affects radiative forcing of the climate. The general analytical technique for DMS in seawater (purge and trap analytical method, P&T) is complex onboard ship. Thus it is difficult to obtain sufficient data for a comprehensive understanding of the spatiotemporal variability of DMS in the sea surface layer. On the other hand, a new analytical method for DMS using SPME (solid-phase microextraction) has recently been developed as an alternative method to P&T. This method is simpler than P&T because no special or complex apparatus is needed. If it is possible to preserve DMS for an extended period in excess of the duration of the cruise, the SPME method is a promising method for measuring DMS in seawater. We assessed an analytical method which can allow us to preserve DMS on the long-term scale using SPME. In liquid nitrogen (-196 degrees C), as preserved environment, for a period of 20 days after sampling, we found the preservation rate of DMS to be 94.7 +/- 4.4% (n = 6) in this study. Furthermore, estimating the distribution coefficient with respect to the effect of salinity on SPME, we found that DMS changed by 0.1 nM/% sal, suggesting that salinity has only a minor influence on oceanic DMS measurements in the open ocean because the minimal change of the open ocean salinity is within 2 %. Applying the SPME method to open ocean samples, we found that there were no significant differences in DMS between the unpreserved and preserved samples (r = 0.99, n = 26, SE = 0.01, p < 0.0001), showing the SPME method has potential for use for open ocean surveys.     

The salvage of aneurysmal fistulae utilizing a modified buttonhole cannulation technique and multiple cannulators

We describe the St Michael's Hospital (SMH) modified buttonhole (BH) cannulation technique as a method that offers a solution for fistulae with aneurysmal dilatation due to repetitive cannulation in a restricted area. This is a prospective cohort study of 14 chronic hemodialysis (HD) patients with problematic fistulae (marked aneurysmal formation and thinning of the overlying skin, bleeding during treatment, and prolonged hemostasis post-HD) because of repetitive, localized cannulation. Each patient was followed for 12 months. The protocol was as follows: creation of tunnel tracks by 1 to 3 experienced cannulators per patient, using sharp needles. After the tunnel tracks were established and cannulation was easily achieved with dull needles, additional cannulators were incorporated with the guidance of a mentor. Bleeding from cannulation sites during dialysis ceased within 2 weeks and skin damage resolved within 6 months in all patients. Hemostasis time postdialysis decreased from 24 to 15 min. Cannulation pain scores decreased significantly. Access flows and dynamic venous pressure measurements remained unchanged. No interventions were required to maintain access patency. In 2 cases, the aneurysms became much less evident. Complications included one episode of septic arthritis and one contact dermatitis. A third patient developed acute bacterial endocarditis 9 months following completion of her follow-up. The SMH modified BH cannulation technique can salvage problematic fistulae, prevent further damage, and induce healing of the skin in the areas of repetitive cannulation. This technique can be successfully achieved by multiple cannulators in a busy full-care HD unit.