Search

In Hyper endemic zones Malaria is known to present with unusual complications. Haemophagocytic syndrome is a disorder of mononuclear phagocytic syndrome. There are many published reports of haemophagocytic syndrome due to P. falciparum infection but haemophagocytic syndrome due to P. vivax infection is quite rare. [ABSTRACT FROM AUTHOR]

Leukemoid reaction is defined as an absolute neutrophil count(ANC) of >30,000/cumm. First described by Holland and Maurer in 1963 leukemoid reaction is associated with infection, anemia, bronchopulmonary dysplasia, use of antenatal steroids, prematurity. Neonatal leukemoid reaction is seen as a neonatal response to hypoxia and can mimic leukemia. In our case the baby was premature and the leukemoid reaction was due to early onset sepsis. Clinicians need to keep sepsis in mind while dealing with neonatal leukemoid reaction. [ABSTRACT FROM AUTHOR]

Previous work has shown that the stiffness of poly(lactide)-b-poly(ethylene oxide)-b-poly(lactide) PLA−PEO−PLA hydrogels can be influenced by crystallinity. Those hydrogels with crystalline PLLA end blocks had a higher storage modulus (up to 1 order of magnitude) than the amorphous equivalents. All the previous work was done with polymers synthesized in the bulk. This paper reports the difference in mechanical properties when two different synthetic techniques are usedbulk and solution synthesis. Solution-synthesized polymers consistently formed stiffer hydrogels than bulk-synthesized polymers. Further investigation determined the following:  crystalline polymers from solution synthesis still form stiffer gels than the amorphous analogues, but not to the extent previously reported; the solution synthesized polymers have narrower distributions, but this alone does not account for the mechanical differences. However, the presence of asymmetric triblock copolymers, which act like an effective diblock copolymer, within the bulk-synthesized materials appears to lower the overall stiffness of the gel. The impact on modulus is much larger for amorphous PLA than for crystalline PLLA end block materials. These findings suggest bulk-synthesized polymers likely have more asymmetric triblock copolymers, that decrease the relaxation time of the system, possibly by lowering the junction lifetime, or lead to dangling ends in the network, which cause a loss in mechanical properties when compared to solution-synthesized polymers. [ABSTRACT FROM AUTHOR]

We report the energetics of association in polymeric gels with two types of junction points: crystalline hydrophobic junctions and polymer−nanoparticle junctions. Time−temperature superposition (TTS) of small-amplitude oscillatory rheological measurements was used to probe crystalline poly(l-lactide) (PLLA)-based gels with and without added laponite nanoparticles. For associative polymer gels, the activation energy derived from the TTS shift factors is generally accepted as the associative strength or energy needed to break a junction point. Our systems were found to obey TTS over a wide temperature range of 15−70 °C. For systems with no added nanoparticles, two distinct behaviors were seen, with a transition occurring at a temperature close to the glass transition temperature of PLLA, Tg. Above Tg, the activation energy was similar to the PLLA crystallization enthalpy, suggesting that the activation energy is related to the energy needed to pull a PLLA chain out of the crystalline domain. Below Tg, the activation energy is expected to be the energy required to increase mobility of the polymer chains and soften the glassy regions of the PLLA core. Similar behavior was seen in the nanocomposite gels with added laponite; however, the added clay appears to reduce the average value of the activation enthalpy. This confirms our SAXS results and suggests that laponite particles are participating in the network structure. [ABSTRACT FROM AUTHOR]

ABA triblock copolymers in solvents selective for the midblock are known to form associative micellar gels. We have modified the structure and rheology of ABA triblock copolymer gels comprising poly(lactide)−poly(ethylene oxide)−poly(lactide) (PLA−PEO−PLA) through addition of a clay nanoparticle, laponite. Addition of laponite particles resulted in additional junction points in the gel via adsorption of the PEO corona chains onto the clay surfaces. Rheological measurements showed that this strategy led to a significant enhancement of the gel elastic modulus with small amounts of nanoparticles. Further characterization using small-angle X-ray scattering and dynamic light scattering confirmed that nanoparticles increase the intermicellar attraction and result in aggregation of PLA−PEO−PLA micelles. [ABSTRACT FROM AUTHOR]

We have shown that we can significantly modify the nanoscale structure of solution and gels of ABA triblock copolymers in a solvent selective for the mid B block by making simple changes to the stereochemistry of the A block. We have also shown that the length of the A block can be used as an additional variable to further modify and thereby control the sizes of the nanoscale domains formed by these polymers in the presence of the solvent. Our systems are poly(lactide)−poly(ethylene oxide)−poly(lactide) solutions and gels, which have been previously shown to have tunable release characteristics and mechanical properties suitable for applications in tissue engineering and drug delivery. We have performed SANS to understand the self-assembly of these polymers in aqueous solution as a function of block length and stereospecificity of the PLA block as well as polymer concentration. A significant difference in structure and association behavior was seen between polymers made from amorphous d/l-lactic acid as compared to those with crystalline l-lactic acid blocks. In the former case, spherical micelles with radii of 10−14 nm form, whereas the latter forms assemblies of nonspherical “lamellar micelles” with characteristic radii of 11−15 nm and thicknesses of 8−10 nm. In both cases, increasing PLA block length leads to a larger characteristic size. Both polymers form an associative network structure at higher concentrations, leading to gelation. [ABSTRACT FROM AUTHOR]

We observe large-scale structures in hydrogels of poly(l-lactide)−poly(ethylene oxide)−poly(l-lactide) (PLLA−PEO−PLLA) ranging in size from a few hundred nanometers to several micrometers. These structures are apparent through both ultra-small angle scattering (USAS) techniques and confocal microscopy. The hydrogels showed power law scattering in the USAS regime, which is indicative of scattering from fractal structures. The fractal dimension of the scattering from hydrogels revealed that the gels have large size aggregates with a mass fractal structure over the nanometer-to-micrometer length scales. The aggregates also seem to become more “dense” with an increase in the molecular weight of crystalline PLLA domains. Visualization through confocal microscopy confirms that the gels have a microstructure of interspersed micrometer-sized polymer inhomogeneities with water channels running between them. The presence of micrometer-sized water channels in the hydrogels has very important implications for biomedical applications. [ABSTRACT FROM AUTHOR]

Background: Low socioeconomic status is known be associated with occurrence as well as poor outcome of stroke in many countries but there is lack of Indian data regarding this. Objectives: To determine whether there is association between joblessness and in hospital outcome in Indian patients with stroke, both ischemic and hemorrhagic. If so, whether the association is independent of other prognostic factors. Methodology: AIIMS stroke register was used for this study. The independent variables were demographic job status, education, cardiovascular risk factors, co-morbidities and the score on Glasgow coma scale (GCS). The outcome variables were mortality and Barthel's index (BI) score at discharge. Results: Five hundred and ninety nine consecutive patients comprising 370 men (54.3%) and 229 (33.6%) women were available for analysis. Their mean age was 55.63±15.36 years. Age, diagnosis (ischemic or hemorrhagic), midline shift, smoking and GCS were significantly associated with mortality and BI score (P<0.05). There was statistically significant association between job and BI at discharge (P=0.03) in univariate analysis. In multivariate analysis joblessness was associated with lower BI at discharge (P=0.02), after adjustment for GCS motor score and stroke subtype. Conclusion: Our study shows that in Indian patients with stroke, joblessness is associated with significantly poor outcome at discharge from the hospital. The association is independent of other prognostic factors. [ABSTRACT FROM AUTHOR]