Interaction of hemoglobin Grey Lynn (Vientiane) with a non-deletional α+-thalassemia in an adult Thai proband

Hemoglobin (Hb) Grey Lynn is a Hb variant caused by a substitution of Phe for Leu at position 91 of α1-globin chain, originally described in individual of unknown ethnic background. This article addresses the interaction of Hb Grey Lynn with a non-deletional α⁺-thalassemia found in Thailand, a hitherto un-described condition. The proband was adult Thai woman referred for investigation of mild anemia with Hb 90 g/L. Hb analyses using low pressure liquid chromatography raised a suspicion of abnormal Hb presence, which was failed to demonstrate by cellulose acetate electrophoresis and capillary electrophoresis. DNA sequencing identified a CTT (Leu) to TTT (Phe) mutation at codon 91 corresponding to the Hb Grey Lynn (Vientiane) [α91(FG3)Leu>Phe (α1) on α1-globin gene and a C deletion between codons 36 and 37 on α2-globin gene causing α⁺-thalassemia. As compared to those observed in a compound heterozygote for Hb Grey Lynn / α⁰-thalassemia reported previously, higher MCV (81.7 fL) and MCH (26.3 pg) values with a lower level of Hb Grey Lynn (19.7%) were observed in the proband. The normochromic normocytic anemia observed could be due to the interaction of Hb Grey Lynn with α⁺-thalassemia. The two mutations could be identified using PCR-RFLP and allele-specific PCR assays developed.     

Linking Physical and Numerical Modelling in Hydrogeology using Sand Tank Experiments and COMSOL Multiphysics

Visualising subsurface processes in hydrogeology and building intuition for how these processes are controlled by changes in forcing is hard for many undergraduate students. While numerical modelling is one way to help undergraduate students explore outcomes of multiple scenarios, many codes are not user‐friendly with respect to defining domains, boundary conditions, and coupling processes, and numerical modelling exercises are also often disconnected from systems that the students understand, limiting their ability to extrapolate what they have learned for other situations. Here, we test the hypothesis that hydrogeology students will better estimate rates of groundwater flow and contaminant transport and the magnitudes of the parameters that control flow and transport by linking physical and numerical models. We present an exercise that links physical and numerical modelling of fluid flow and solute transport using 2‐D ‘ant farm’ sand tanks with parallel models in COMSOL Multiphysics. The sand tank exercises provide students with a way to visualise subsurface flow and transport processes, while COMSOL allows them to explicitly pull apart the mathematics associated with these systems and build intuition for their solutions. Given coupled experimentation and numerical exercises, we find that students will connect processes that they see in the laboratory with the outcomes of numerical models, and the post‐exercise tests indicate that they have an improved understanding of: (1) the magnitude and importance of properties and parameters that control flow and transport and (2) the simplifications made in numerical models of physical systems.     

Free Radical Scavenging Properties of Skin and Pulp Extracts of Different Grape Cultivars In Vitro and Attenuation of H2O2-Induced Oxidative Stress in Liver Tissue Ex Vivo

Grapes are the richest source of antioxidants due to the presence of potent bioactive phytochemicals. In this study, the phytochemical contents, scavenging activities and protective role against H₂O₂-induced oxidative stress in liver tissue ex vivo of four grape (Vitis vinifera) cultivars extracts, namely Flame seedless (black), Kishmish chorni (black with reddish brown), Red globe (red) and Thompson seedless mutant (green), were evaluated. The total phenolics and flavonoids content in pulp or skin fractions of different grape cultivars were in the range of 47.6–310 mg gallic acid equivalent/g fresh weight (fw), and 46.6–733.3 µg catechin equivalent/g fw respectively. The scavenging activities in skin of different grape varieties against 2,2-diphenyl-1-picrylhydrazyl (44–58 %), hydrogen peroxide (15.3–18.6 %), and hydroxyl radicals (50–85 %), were higher than pulp of the corresponding cultivars. These scavenging activities of grape extracts were found to be significantly (p < 0.01) correlated with the levels of total phenols, flavonoids and ascorbic acid. Liver tissues from goat treated with H₂O₂ (500 μM) showed significantly decreased GSH content by 42.9 % and activities of catalase by 50 % and glutathione reductase by 66.6 %; while increased thiobarbituric acid reactive substances and nitric oxide level by 2.53- and 0.86-fold, respectively, and activity of glutathione S-transferase by 0.96-fold. Grape skin extracts showed the stronger protective activity against H₂O₂-induced oxidative stress in liver tissue ex vivo, than its pulp of any cultivar; and the Flame seedless (black) cultivar showed the highest potential. In conclusion, our study suggested that the higher antioxidant potential, phytochemical contents and significant scavenging capacities in pulp and skin of grape extracts showed the protective action of grape extracts against H₂O₂-induced oxidative stress in liver tissue ex vivo.