Jeganathan, S. | Search bioRxiv

bioRxiv2019

Bubble Trouble: Conquering Microbubble Limitations in Contrast Enhanced Ultrasound Imaging by Nature-Inspired Ultrastable Echogenic Nanobubbles

Advancement of ultrasound molecular imaging applications requires not only a reduction in size of the ultrasound contrast agents (UCAs) but also a significant improvement in the in vivo stability of the shell-stabilized gas bubble. The transition from first generation to second generation UCAs was marked by an advancement in stability as air was replaced by a hydrophobic gas, such as perfluoropropane and sulfur hexafluoride. Further improvement can be realized by focusing on how well the UCAs shell can retain the encapsulated gas under extreme mechanical deformations. Here we report the next generation of UCAs for which we engineered the shell structure to impart much better stability under repeated prolonged oscillation due to ultrasound, and large changes in shear and turbulence as it circulates within the body. By adapting an architecture with two layers of contrasting elastic properties similar to bacterial cell envelopes, our ultrastable nanobubbles (NBs) withstand continuous in vitro exposure to ultrasound with minimal signal decay and have a significant delay on the onset of in vivo signal decay in kidney, liver, and tumor. Development of ultrastable NBs can potentially expand the role of ultrasound in molecular imaging, theranostics, and drug delivery.

bioengineering↗

bioRxiv2018

Nutritional status and morbidity profile of children with contact to leprosy in the rural community.

IntroductionChildhood leprosy reflects upon the disease transmission in the community. So, this study aimed to find out the children with contact to leprosy in their surroundings, prevalence of leprosy or subclinical infections in them and to assess their nutritional status. The study was conducted for 2 months and analysed 70 children in the rural community who were living with a household contact of leprosy.\n\nMethods70 children in the rural areas surrounding Chengalpattu living with leprosy contacts were selected for carrying out the study. Information regarding their demographic characteristics, socioeconomic factors, environmental conditions, feeding practices, food habits and any present health problems or in the recent past were collected. The children were then subjected to anthropometric measurements. The children were clinically evaluated by a dermatologist qualified in paediatric leprosy and children who were diagnosed as cases of leprosy were classified according to Ridley-Jopling classification. Slit skin smears for acid fast bacilli was done in all children with suspicious skin lesions.\n\nResultsOut of the 70 children taken into the study, 41 were boys and 29 were girls. 7-22% of boys and 3-6% of girls and overall,4-15% children are severely malnourished. 19 out of the 70 children had clinical pallor. Among the 70 leprosy contact children, 3 children were diagnosed to have leprosy (4.28%).Of the 3, 2 children had multibacillary leprosy while 1 had paucibacillary leprosy, according to the WHO classification and all 3 were classified as cases of Borederline Tuberculoid Leprosy according to Ridley-Jopling classification. All these 3 children had contact to leprosy for 10 or more years living with them.\n\nConclusionIt can be concluded that malnutrition, the closeness and duration of contact to leprosy are significant risk factors for leprosy. Regular contact screening and early case detection are essential strategies to prevent further transmission in the endemic areas. Diagnostic methods for detection of subclinical infection in contacts needs further research.

epidemiology↗