Modeling of micropipette aspiration and optical tweezers stretching of erythrocytes with or without Malaria parasite

The erythrocytes play an important role in the human body. The healthy erythrocytes can undergo extremely large deformation while passing through small capillaries. Their infection by Malaria Plasmodium falcipurum （P.f.） will lead to capillary blockage and blood flow obstruction. Many experimental and computational methods have been applied to study the increase in stickiness and decrease in deformability of the Malaria （P.f.） infected erythrocytes. The novelty of this paper lies in the establishment of an multi-component model for investigating mechanical properties of Malaria （P.f.） infected erythrocytes, especially of their enclosed parasites. Finite element method was applied to simulate the erythrocytes＇ deformation in micropipette aspiration and optical tweezers stretching using the computational software ABAQUS. The comparisons between simulations and experiments were able to quantitatively conclude the effects of stiffness and stickiness of the parasitophorous vacuole membrane on the cells＇ deformation, which could not be obtained from experiments directly.

Effectiveness of intermittent preventive treatment in pregnancy with sulfadoxine-pyrimethamine: An in silico pharmacological model

Objective:To explore the efficacy of intermittent preventive treatment in pregnancy(IPTp)with sulfadoxine and pyrimethamine(SP)against sensitive parasites.Methods:A pharmacological model was used to investigate the effectiveness of the previous recommended at least two-dose regimen,currently recommended three-dose regimen and 4,6,8-weekly regimens with specific focus on the impact of various nonadherence patterns in multiple transmission settings.Results:The effectiveness of the recommended three-dose regimen is high in all the transmission intensities,i.e.>99%,98%and 92%in low,moderate and high transmission intensities respectively.The simulated 4 and 6 weekly IPTp-SP regimens were able to prevent new infections with sensitive parasites in almost all women(>99%)regardless of transmission intensity.However,8 weekly interval dose schedules were found to have 71%and 86%protective efficacies in high and moderate transmission areas,respectively.It highlights that patients are particularly vulnerable to acquiring new infections if IPTp-SP doses are missed.Conclusions:The pharmacological model predicts that full adherence to the currently recommended three-dose regimen should provide almost complete protection from malaria infection in moderate and high transmission regions.However,it also highlights that patients are particularly vulnerable to acquiring new infections if IPTp doses are spaced too widely or if doses are missed.Adherence to the recommended IPTp-SP schedules is recommended.

Knowledge &Utilization of Long Lasting Impregnated Nets among Housewives in Al Moneera City and Al Koozi Villages, Hodieda Governorate, Republic of Yemen 2007

Malaria is considered as one of the main health problem in the Republic of Yemen. In February 2006 National Malaria Control Program started freely distribution of Long Lasting Impregnated Nets (LLINs) for vulnerable groups to malaria infection (pregnant women and children under 5 years). After one year of distribution, there is a need to measure the use rate among vulnerable groups and explore factors affecting their use. The aim of the study was to investigate the use rate of long lasting impregnated nets among children under five years and pregnant women in Al Moneera city and Al Koozi villages of Hodieda governorate. Methodology: Cross section study with multistage sample, Random selection of one urban and one rural locality. 768 housewives were interviewed, proportionally allocated sample according to the number of vulnerable groups in each locality. Systematic random sample to select households. Results: The use rate of LLINs for vulnerable groups was 74.3% CI (71.2 - 77.4). There was no statistically significant association between the use of LLINs and residence, also with ages of housewives, occupation, type of house, but there is strong statistically significant association between use of LLINs and having correct information about how to use and to take care of them P value < 0.001, also with educational status of housewives;P value 0.03 and educational status of fathers;P value 0.01. (84%) have correct information about how to use and take care of LLINs and the main source of information was health workers who distributed them. Only 13.4% realized pregnant women as a vulnerable group to malaria infection while about 77.9% realized children as a vulnerable group to malaria infection. The main reason of LLINs use (84.8%) was protection from nuisance of insects. Conclusion and recommendations: There is shortage in the information about the protective effect of LLINs from malaria infection and the main reason of using them is protection from nuisance of insects. There is a need to increase health awareness about the role of LLINs in malaria prevention.