We report the development and characterization of a method, named reversible association with motor proteins (RAMP), for manipulation of organelle positioning within the cytoplasm. RAMP consists of coexpressing in cultured cells (i) an organellar protein fused to the streptavidin-binding peptide (SBP) and (ii) motor, neck, and coiled-coil domains from a plus-end–directed or minus-end–directed kinesin fused to streptavidin. The SBP–streptavidin interaction drives accumulation of organelles at the plus or minus end of microtubules, respectively. Importantly, competition of the streptavidin–SBP interaction by the addition of biotin to the culture medium rapidly dissociates the motor construct from the organelle, allowing restoration of normal patterns of organelle transport and distribution. A distinctive feature of this method is that organelles initially accumulate at either end of the microtubule network in the initial state and are subsequently released from this accumulation, allowing analyses of the movement of a synchronized population of organelles by endogenous motors.

Syndecan-1 is the predominant heparan sulfate proteoglycan found on the surface of epithelial cells, and like glutamine, is essential in maintaining the intestinal epithelial barrier. We therefore hypothesized that loss of epithelial syndecan-1 would abrogate the gut protective effects of enteral glutamine. Both an in vitro and in vivo model of gut ischemia/reperfusion (I/R) was utilized. In vitro, intestinal epithelial cells underwent hypoxia/reoxygenation (H/R) to mimic gut I/R with 2mM (physiologic) or 10 mM glutamine supplementation. Permeability, caspase activity, cell growth, and cell surface and shed syndecan-1 were assessed. In vivo, wild type (WT) and syndecan-1 knockout (KO) mice received ± enteral glutamine followed by gut I/R. Intestinal injury was assessed by fluorescent dye clearance and histopathology, permeability as mucosal to serosal clearance ex vivo in everted sacs, and inflammation by myeloperoxidase (MPO) activity. In an in vitro model of gut I/R, glutamine supplementation reduced epithelial cell permeability and apoptosis and enhanced cell growth. Shed syndecan-1 was reduced by glutamine without an increase in syndecan-1 mRNA. In vivo, intestinal permeability, inflammation, and injury were increased after gut I/R in WT mice and further increased in syndecan-1 KO mice. Glutamine’s attenuation of I/R-induced intestinal hyperpermeability, inflammation, and injury were abolished in syndecan-1 KO mice. These results suggest that syndecan-1 plays a novel role in the protective effects of enteral glutamine in the post ischemic gut.

Microtubule severing enzymes Katanin and Spastin cut the microtubule (MT) into smaller fragments and are being studied extensively using in-vitro experiments due to their crucial role in different cancers and
neurodevelopmental disorders. It has been reported that the severing enzymes are either involved in increasing or decreasing the tubulin mass. Currently, there are a few analytical and computational models for MT amplification and severing. However, these models do not capture the action of microtubule severing explicitly, as these are based on partial differential equations in one dimension. On the other hand, a few discrete lattice-based models were used earlier to understand the activity of severing enzymes only on stabilized MTs. Hence, in this study, discrete lattice-based Monte Carlo models that included microtubule dynamics and severing enzyme activity have been developed to understand the effect of severing enzymes on tubulin mass, MT number, and MT length. It was found that the action of severing enzyme reduces average MT length while increasing their number; however, the total tubulin mass can decrease or increase depending on the concentration of GMPCPP (Guanylyl-(α, β)-methylene-diphosphonate) - which is a slowly hydrolyzable analogue of GTP (Guanosine triphosphate). Further, relative tubulin mass also depends on the detachment ratio of GTP/GMPCPP and GDP (Guanosine diphosphate) tubulin dimers and the binding energies of
tubulin dimers covered by the severing enzyme.

Mortality is a continuous force of attrition, tending to reduce the population, a prime negative force in the balance of vital processes (Bhasin and Nag, 2004). Sample Registration System (SRS) serves as the only source of annual data on vital events on a full scale from 1969-70 in India. Few studies have examined the trends and patterns of mortality across time and regions in India (Preston and Bhat, 1984). The Under 5 Mortality Rates (U5MR) can be seen to decrease by more than half from 1970 to 2017 but in contrast little is known about the mortality patterns of the older children (5-9) and young adolescents (10-14), and not many studies have been done on their changing trends (Masquelier et al., 2018). Using the annual data for the 5-14 age, the trend of decline in the mortality patterns is studied from 1970 to 2013. The linear trend in the time series plot suggests analysis using time series models AR(p), MA(q), ARMA(p,q), Box- Jenkins ARIMA(p,d,q) and Random Walk with drift models to get the best fit to the trend of the data. The order of the time series models have been calculated by studying the ACF, PACF plots and the coefficients have been derived using the Yule-Walker equation matrix. An in-sample forecast of the years 2014-17 are taken. The Mean Squared Error (MSE) and the Mean Absolute Percentage Error (MAPE) as a measure of accuracy is used to determine the best fit model. ARIMA(3,1,1) produced lower values making it the best-fit model. Out-of-sample forecasting was done for 2018-2025. The forecast value shows that at the current trend, India would have 0.03 deaths per 1000 population in the 5-14 age group in 2025 showing that the government’s policies and health care interventions towards realization of the MDG4 goal is working positively.

No abstract