Ultrasonography as a tool in predicting the severity of dengue fever in children—a useful aid in a developing country

Background

Dengue fever accounts for significant mortality in developing countries. Dengue fever serology takes a week at least to be reported positive, thus necessitating the need for other markers of diagnosis and prognosis.

Objective

The purpose of this study was to investigate the role of ultrasonography as a tool in diagnosing and predicting the severity of dengue fever in children.

Materials and methods

This was a prospective study conducted in a tertiary pediatric centre from September 2010 to July 2012. Three hundred twenty-four children with confirmed dengue fever were compared with 422 children of suspected dengue fever. Severity of illness was graded as per WHO criteria and sonography findings were correlated to the grade of illness.

Results

Gallbladder wall thickening was seen in 75% of the children with confirmed dengue fever. A significant difference was seen between survivors and non-survivors with respect to pericholecystic fluid collection (P?=?0.002), hepatic intraparenchymal fluid (P?<?0.001), splenomegaly (P?=?0.002), splenic subcapsular fluid (P?<?0.001), peripancreatic fluid (P?<?0.001), perirenal fluid (P?<?0.001) and pericardial fluid (P?<?0.001). Other findings included ascites, pleural effusion, hepatomegaly and splenomegaly, which were present irrespective of grade of illness.

Conclusions

Ultrasonography can be used as a useful tool in developing countries to predict the severity of dengue fever in children.     

Predicting the diffusion coefficient of water vapor through glassy HPMC films at different environmental conditions using the free volume additivity approach

Prediction of diffusion coefficient of polymer materials is important in the pharmaceutical research and becomes the aim of this paper. This paper bases the prediction method on the estimation of the polymer fractional free volume at different environmental conditions. Focussing on glassy polymers, the free volumes of polymer films were estimated using the model of Vrentas et al. [J.S. Vrentas, J.L. Duda, H.-C. Ling, Antiplasticization and volumetric behavior in glassy polymers, Macromolecules 21 (1988) 1470–1475]. The required data are the moisture sorption and glass transition temperature data, which were measured on various hydroxypropyl methylcellulose (used as a model material) free films at different water activities. The temperature and molecular weight particularly determine the free volume of the polymer, while the sorbed water can either decease or increase the specific free volume of the polymer. At high water activity, the amount of water sorbed in the film increases to such level that the direct free volume addition by water becomes proportional to the contribution of the polymer itself. This confirms the importance of considering the environmental effect on the diffusivity of polymer during coating material selection. The presented approach enables the prediction of the diffusivity at any given relevant material variable and therefore has the potency to be used as a formulation development tool.     

Quantitative Image Analysis for Evaluating the Coating Thickness and Pore Distribution in Coated Small Particles

Purpose  This study aims to develop a characterization method for coating structure based on image analysis, which is particularly promising for the rational design of coated particles in the pharmaceutical industry. Methods  The method applies the MATLAB image processing toolbox to images of coated particles taken with Confocal Laser Scanning Microscopy (CSLM). The coating thicknesses have been determined along the particle perimeter, from which a statistical analysis could be performed to obtain relevant thickness properties, e.g. the minimum coating thickness and the span of the thickness distribution. The characterization of the pore structure involved a proper segmentation of pores from the coating and a granulometry operation. Results  The presented method facilitates the quantification of porosity, thickness and pore size distribution of a coating. These parameters are considered the important coating properties, which are critical to coating functionality. Additionally, the effect of the coating process variations on coating quality can straight-forwardly be assessed. Conclusions  Enabling a good characterization of the coating qualities, the presented method can be used as a fast and effective tool to predict coating functionality. This approach also enables the influence of different process conditions on coating properties to be effectively monitored, which latterly leads to process tailoring.