Cellulose acetate-Sn(IV) molybdophosphate: A biopolymer supported composite Exchanger for the removal of selected heavy metal ions

Cellulose acetate-tin(IV) molybdophosphate (CATMP) composite exchanger was prepared by mixing biopolymer celluloseacetate with its inorganic counterpart tin(IV) molybdophosphate (TMP) using sol‑gel method. The physical characterization of the as synthesized exchanger was carried out by FTIR, XRD, BET, TGA-DTG and SEM-EDX techniques. Chemical properties such as ion exchange capacity, chemical stability, pH and distribution behavior were carried out. The average IEC of the composite material, as determined by batch equilibrium, was found to be 2.43 meq/g for Na+ ion; higher than its inorganic counterpart, i.e. 1.41 meq/g. This exchanger was also found to be stable in water, acids and organic solvents, but unstable in basic medium. The distribution study (Kd) of the exchanger in different solvent systems showed promising separation potential of the exchanger towards metal ions of analytical interest from a given mixture of toxic heavy metal ions. The sorption studies revealed that the material was selective for Cr(III) and Cd(II) ions and moderately selective for Co(II) ion in solvents employed in this work. Its selectivity was examined by achieving some important binary separations of metal cations on its column indicating its promising application in environmental pollution abatement.                     KEY WORDS: Cation exchanger, Biopolymer, Organic-inorganic hybrid, Sol–gel method, Binary distribution   Bull. Chem. Soc. Ethiop. 2020, 34(2), 259-276 DOI: https://dx.doi.org/10.4314/bcse.v34i2.

Undernutrition among Ethiopian adults living with HIV: a meta-analysis.

BackgroundMalnutrition and human immunodeficiency virus (HIV) are interlaced in a vicious cycle and worsened in low and middle-income countries. In Ethiopia, even though individuals are dually affected by both malnutrition and HIV, there is no a nationwide study showing the proportion of malnutrition among HIV-positive adults. Consequently, this review addressed the pooled burden of undernutrition among HIV-positive adults in Ethiopia.MethodsWe searched for potentially relevant studies through manual and electronic searches. An electronic search was carried out using the database of PubMed, Google Scholar, and Google for gray literature and reference lists of previous studies. A standardized data extraction checklist was used to extract the data from each original study. STATA Version 13 statistical software was used for our analysis. Descriptive summaries were presented in tables, and the quantitative result was presented in a forest plot. Heterogeneity within the included studies was examined using the Cochrane Q test statistics and I 2 test. Finally, a random-effects meta-analysis model was computed to estimate the pooled proportion of undernutrition among HIV-positive adults.ResultsAfter reviewing 418 studies, 15 studies met the inclusion criteria and were included in the meta-analysis. Findings from 15 studies revealed that the pooled percentage of undernutrition among HIV-positive adults in Ethiopia was 26% (95% CI: 22, 30%). The highest percentage of undernutrition (46.8%) was reported from Jimma University specialized hospital, whereas the lowest proportion of undernutrition (12.3%) was reported from Dilla Hospital. The subgroup analyses of this study also indicated that the percentage of undernourishment among HIV-positive adults is slightly higher in the Northern and Central parts of Ethiopia (27.5%) as compared to the Southern parts of Ethiopia (25%).ConclusionThis study noted that undernutrition among HIV-positive adults in Ethiopia was quite common. This study also revealed that undernutrition is more common among HIV-positive adults with advanced disease stage, anemia, diarrhea, CD4 count less than 200 cells/mm3, and living in rural areas. Based on our findings, we suggested that all HIV-positive adults should be assessed for nutritional status at the time of ART commencement

Breeding Chickpea for Early Phenology: Perspectives, Progress and Prospects

Chickpea (Cicer arietinum L.) is currently grown in over 50 countries representing a wide range of environments and cropping systems. Phenology (time to flowering, podding and maturity) is an important component of crop adaptation in these environments. Crop maturity ranges from 80 to 180 days depending on genotype, soil moisture, time of sowing, latitude and altitude. However, in at least two-thirds of the chickpea growing area, the available crop-growing season is short (90-120 days) due to risk of drought or temperature extremities at the end of season (pod filling stage of the crop). About 73% of the global chickpea area is in South and Southeast Asia where chickpea is largely grown rainfed in the post-rainy season on receding soil moisture and often experiences terminal drought and heat stresses. Early phenology is also important in autumn-sown rainfed crop in Mediterranean-type environments for escape from terminal drought, as in Australia; and in summer-grown crop in the temperate environments for escape from frost at the end of season, as in Canada. Early phenology is also needed for promotion of chickpea to rice-fallows and other late sown conditions of south Asia. Hence, development of early maturing cultivars is one of the major objectives in chickpea breeding programs of International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, India and in several countries, including India, Myanmar, Bangladesh, Ethiopia, Australia and Canada. Several short-duration cultivars with resistance to fusarium wilt have been developed which have made significant impacts on enhancing chickpea area and production in central and southern India, Myanmar and Ethiopia. Efforts are being made to combine earliness with resistance to ascochyta blight and chilling tolerance for enhancing adaptation of chickpea to short-season Mediterranean regions and temperate environments. Early and extra-early cultivars are expected to play key role in expanding chickpea area in new niches where available crop growing season is short

Mouse models of nesprin-related diseases

Nesprins (nuclear envelope spectrin repeat proteins) are a family of multi-isomeric scaffolding proteins. Nesprins form the LInker of Nucleoskeleton-and-Cytoskeleton (LINC) complex with SUN (Sad1p/UNC84) domain-containing proteins at the nuclear envelope, in association with lamin A/C and emerin, linking the nucleoskeleton to the cytoskeleton. The LINC complex serves as both a physical linker between the nuclear lamina and the cytoskeleton and a mechanosensor. The LINC complex has a broad range of functions and is involved in maintaining nuclear architecture, nuclear positioning and migration, and also modulating gene expression. Over 80 disease-related variants have been identified in SYNE-1/2 (nesprin-1/2) genes, which result in muscular or central nervous system disorders including autosomal dominant Emery–Dreifuss muscular dystrophy, dilated cardiomyopathy and autosomal recessive cerebellar ataxia type 1. To date, 17 different nesprin mouse lines have been established to mimic these nesprin-related human diseases, which have provided valuable insights into the roles of nesprin and its scaffold LINC complex in a tissue-specific manner. In this review, we summarise the existing nesprin mouse models, compare their phenotypes and discuss the potential mechanisms underlying nesprin-associated diseases

N-terminal nesprin-2 variants regulate β-catenin signalling

The spatial compartmentalisation of biochemical signalling pathways is essential for cell function. Nesprins are a multi-isomeric family of proteins that have emerged as signalling scaffolds, herein, we investigate the localisation and function of novel nesprin-2 N-terminal variants. We show that these nesprin-2 variants display cell specific distribution and reside in both the cytoplasm and nucleus. Immunofluorescence microscopy revealed that nesprin-2 N-terminal variants colocalised with β-catenin at cell-cell junctions in U2OS cells. Calcium switch assays demonstrated that nesprin-2 and β-catenin are lost from cell-cell junctions in low calcium conditions whereas emerin localisation at the NE remained unaltered, furthermore, an N-terminal fragment of nesprin-2 was sufficient for cell-cell junction localisation and interacted with β-catenin. Disruption of these N-terminal nesprin-2 variants, using siRNA depletion resulted in loss of β-catenin from cell-cell junctions, nuclear accumulation of active β-catenin and augmented β-catenin transcriptional activity. Importantly, we show that U2OS cells lack nesprin-2 giant, suggesting that the N-terminal nesprin-2 variants regulate β-catenin signalling independently of the NE. Together, these data identify N-terminal nesprin-2 variants as novel regulators of β-catenin signalling that tether β-catenin to cell-cell contacts to inhibit β-catenin transcriptional activity

High frequency of Plasmodium falciparum chloroquine resistance marker (pfcrt T76 mutation) in Yemen: An urgent need to re-examine malaria drug policy

<p>Abstract</p> <p>Background</p> <p>Malaria remains a significant health problem in Yemen with <it>Plasmodium falciparum </it>being the predominant species which is responsible for 90% of the malaria cases. Despite serious concerns regarding increasing drug resistance, chloroquine is still used for the prevention and treatment of malaria in Yemen. This study was carried out to determine the prevalence of choloroquine resistance (CQR) of <it>P. falciparum </it>isolated from Yemen based on the <it>pfcrt </it>T76 mutation.</p> <p>Methods</p> <p>A cross-sectional study was carried out among 511 participants from four governorates in Yemen. Blood samples were screened using microscopic and species-specific nested PCR based on the 18S rRNA gene to detect and identify <it>Plasmodium </it>species. Blood samples positive for <it>P. falciparum </it>were used for detecting the <it>pfcrt </it>T76 mutation using nested-PCR.</p> <p>Results</p> <p>The prevalence of <it>pfcrt </it>T76 mutation was 81.5% (66 of 81 isolates). Coastal areas/foothills had higher prevalence of <it>pfcrt </it>T76 mutation compared to highland areas (90.5% <it>vs </it>71.8%) (p = 0.031). The <it>pfcrt </it>T76 mutation had a significant association with parasitaemia (p = 0.045). Univariate analysis shows a significant association of <it>pfcrt </it>T76 mutation with people aged > 10 years (OR = 9, 95% CI = 2.3 - 36.2, p = 0.001), low household income (OR = 5, 95% CI = 1.3 - 19.5, p = 0.027), no insecticide spray (OR = 3.7, 95% CI = 1.16 - 11.86, p = 0.025) and not sleeping under insecticide treated nets (ITNs) (OR = 4.8, 95% CI = 1.38 - 16.78, p = 0.01). Logistic regression model confirmed age > 10 years and low household income as predictors of <it>pfcrt </it>T76 mutation in Yemen <it>P. falciparum </it>isolates.</p> <p>Conclusions</p> <p>The high prevalence of <it>pfcrt </it>T76 mutation in Yemen could be a predictive marker for the prevalence of <it>P. falciparum </it>CQR. This finding shows the necessity for an in-vivo therapeutic efficacy test for CQ.<it> P. falciparum </it>CQR should be addressed in the national strategy to control malaria.</p

The distinct roles of the nucleus and nucleus-cytoskeleton connections in three-dimensional cell migration

Cells often migrate in vivo in an extracellular matrix that is intrinsically three-dimensional (3D) and the role of actin filament architecture in 3D cell migration is less well understood. Here we show that, while recently identified linkers of nucleoskeleton to cytoskeleton (LINC) complexes play a minimal role in conventional 2D migration, they play a critical role in regulating the organization of a subset of actin filament bundles – the perinuclear actin cap - connected to the nucleus through Nesprin2giant and Nesprin3 in cells in 3D collagen I matrix. Actin cap fibers prolong the nucleus and mediate the formation of pseudopodial protrusions, which drive matrix traction and 3D cell migration. Disruption of LINC complexes disorganizes the actin cap, which impairs 3D cell migration. A simple mechanical model explains why LINC complexes and the perinuclear actin cap are essential in 3D migration by providing mechanical support to the formation of pseudopodial protrusions