Tau Mediated Neurodegeneration: An Insight into Alzheimer’s Disease Pathology

Extracellular accumulations of Aβ, hyperphosphorylation of tau and intracellular neurofibrillary tangle formation have been the hallmarks of Alzheimer’s Disease (AD). Although tau and its phosphorylation play a pivotal role in the normal physiology yet its hyperphosphorylation has been a pathological manifestation in neurodegenerative disorders like AD. In this review physiology of tau, its phosphorylation, hyperphosphorylation with the intervention of various kinases, aggregation and formation of paired helical filaments has been discussed. A brief account of various animal models employed to study the pathological manifestation of tau in AD and therapeutic strategies streamlined to counter the tau induced pathology has been given. The reasons for the failure to have suitable animal model to study AD pathology and recent success in achieving this has been included. The role of caspase cascade in tau cleavage has been emphasized. The summary of current studies on tau and the need for future studies has been accentuated.     

Micropropagation and in vitro flowering of endemic and endangered plant Ceropegia attenuata Hook

Factors affecting in vitro propagation were evaluated for Ceropegia attenuata Hook., an endemic and endangered plant having ornamental potential but a limited reproductive capacity. Rapid shoot multiplication from nodal explants was established using varying concentrations of cytokinins and auxins either alone or in combinations. The highest frequency of shoot induction was achieved when nodal explants were inoculated on Murashige and Skoog (MS) medium supplemented with 13.31 μM 6-benzylaminopurine with a mean of 12.9?±?0.5 shoots per explant. High concentrations of TDZ (6.81–11.35 μM) and KN (6.78–11.61 μM) resulted in stunted and vitrified shoots. Factors implicated in the promotion of floral transition of the C. attenuata have been identified which are 4-amino-3, 5, 6-trichloropicolinic acid (picloram), 6-benzylaminopurine, sucrose and photoperiod. The highest frequency of flowering (100%) was obtained when axillary shoot explants were transferred to MS medium supplemented with picloram (4.14 μM) within 4 weeks of culture. Transfer of in vitro regenerated shoots to half strength MS medium with 2.46 μM indole-3-butyric acid (IBA) showed maximum root induction. The in vitro grown plantlets were successfully acclimatized in the glasshouse with 85% of survival and showed normal development. The developed protocol provided a simple, cost-effective approach for the conservation of endangered plant C. attenuata for replenishing its declining populations.     

Early childhood undernutrition,preadolescent physical growth,and cognitive achievement in India: A population-based cohort study

BackgroundThere is a lack of nationally representative estimates for the consequences of early childhood undernutrition on preadolescent outcomes in India. Understanding this relationship is helpful to develop interventions that not only prevent child undernutrition but also mitigate its consequences.Methods and findingsIn this cohort study, we analyzed prospectively gathered data from 2 waves of the India Human Development Survey (IHDS) to investigate the association of undernutrition during early childhood (0 to 5 years) in 2004 to 2005 with physical and cognitive outcomes during preadolescent (8 to 11 years) years in 2011 to 2012. These surveys interviewed 41,554 households across all 33 states and union territories in India in 2004 to 2005 and reinterviewed 83% of the households in 2011 to 2012. Primary exposure was assessed using the Composite Index of Anthropometric Failure (CIAF) based on 2004 to 2005 survey. Primary outcomes were short stature (height-for-age z-score [HAZ] <−2), thinness (body mass index [BMI] <18.5 kg/m²), reading, and arithmetic skills during preadolescence based on the 2011 to 2012 survey. Survey-weighted generalized linear models were used, and effect modification based on child sex and sociodemographic variables were evaluated using 3-way interaction terms. Of the 7,868 children included in this analysis, 4,334 (57.3%) were undernourished. Being undernourished was associated with increased odds of short stature (odds ratio [OR] 1.73, 95% confidence interval [CI] 1.45 to 2.06) and thinness (OR 1.52, 95% CI 1.33 to 1.73) during the preadolescent period, while it was associated with decreased odds of achieving a higher reading (cumulative odds ratio [cumOR]: 0.76, 0.66 to 0.87) and arithmetic (cumOR: 0.72, 0.63 to 0.82) outcomes. The disparity in outcomes based on CIAF increased with age, especially for female children. Increased level of female education within the household reduced the disadvantages of undernutrition among female children. Study limitations include observational and missing data, which limit our ability to draw strong causal inferences.ConclusionsIn this study, we found that early child undernutrition was associated with several adverse preadolescent physical and cognitive outcomes, especially among female children. Improved female education mitigates this association. Female education promotion should assume a central role in Indian public health policy making.

Apurv Soni and co-workers study child nutrition and developmental outcomes in India.     

Salt stress effects on growth and mineral nutrition of French beans

An experiment was designed to study the effects of sodium chloride and sodium sulphate on growth and inorganic contents inPhaseolus vulgaris (L) cvVaghya. It was noted that except at 2.5 and 5 dS/m Na₂SO₄, other concentrations of both the salts proved to be inhibitory. NaCl lowered the chlorophyll content while opposite was the trend with Na₂SO₄. Both the salt caused an increase in leaf thickness and moisture content. Salt rich environment disturbed the normal inorganic metabolism. The contents of Na, Ca, Fe and Mg were greater while those of N, K, Cu and Zn were low. The contents of P and Mn showed a differential response.     

Erythropoietin receptors associate with a ubiquitin ligase,p33RUL,and require its activity for erythropoietin-induced proliferation

The proliferation and survival of hematopoietic cells is strictly regulated by cytokine growth factors that act through receptors of the Type I cytokine receptor family, including erythropoietin (Epo) and its receptor, EpoR. Mitogenic signaling by these receptors depends on activation of Jak tyrosine kinases. However, other required components of this pathway have not been fully identified. In a screen for proteins that interact with EpoR and Jak2, we identified a novel member of the U-box family of ubiquitin ligases. This receptor-associated ubiquitin ligase, RUL, co-precipitated with EpoR from mammalian cells and mediated ubiquitination of EpoR. Also, endogenously expressed RUL was rapidly and transiently phosphorylated on serine after cytokine treatment of factor-dependent hematopoietic cells. Expression of ubiquitin ligase-deficient mutants of RUL inhibited Epo-induced expression of c-myc and bcl-2, two immediate-early genes normally associated with Epo-induced cell growth. Consistent with that finding, expression of mutant RUL also inhibited Epo-dependent proliferation and survival of factor-dependent cells. Together, these observations suggest that RUL is a required component of mitogenic signaling by EpoR. We also show that RUL is phosphorylated in response to growth factors that act through non-cytokine receptors, suggesting that RUL may function as a common regulator of mitogenesis.     

Use of Polytomous Logistic Model in Matched Case-Control Studies

Binary logistic model has been found useful for estimating odds ratio in case of dichotomous exposure variable under matched case-control retrospective design. We describe the use of polytomous logistic model for estimating odds ratios when the exposure of prime interests, relative to disease incidence, has more than two levels. An illustrative example is presented and discussed.