Highlights Prolonged exposure to chlorpyrifos induced locomotor impairments. Chlorpyrifos exposure modified the characteristics of twitch contraction of mammalian skeletal muscle fibers. Structural and functional alterations are reported as adaptation of the fibers muscle to chlorpyrifos exposure.

No abstract

Chlorpyrifos (CPF) is a toxic organophosphate commonly used worldwide. Its residues are being detected in different environmental matrixes and hence in the food chain. Repeated CPF exposure might pose health risk for the general population on long term. This data article contains the data of contractility impairment further to dietary exposure to CPF on a hind limb skeletal muscle; soleus, a typical slow twitch skeletal muscle. Thirty adult male rats Sprague Dawley are divided into three groups receiving the following daily diet for 6 weeks: Group 1 (vehicle), Group 2: CPF1 (CPF 1mg/kg/day) and Group 3: CPF5 (CPF 5 mg/kg/day). Soleus twitch tension and fatigability index are determined at the end of the treatment. The activity of acteylcholinesterase enzyme is assessed in the tissues homogenate. Additionally, we examined the expression levels of ryanodine type 1 receptor (RyR1), ATPase Sarcoplasmic/Endoplasmic Reticulum Ca2+ Transporting 1 (Atp2a1), ATPase Sarcoplasmic/Endoplasmic Reticulum Ca2+ Transporting 2 (Atp2a2) and nicotinic acetylcholine receptor (nAChR) in CPF-exposed skeletal muscle tissue using quantitative real time polymerase chain reaction.CPF exposure at two different doses induced an increase in twitch contraction in soleus muscle along with an increase in fatigability index. These increases are accompanied by low level of acetylcholinesterase enzyme activity as well as modification in genes level expression of nAChR, RyR1, Atp2a1 and Atp2a2 involved in contractility.

Since the Syrian conflict started, Lebanon became a common destination receiving a huge number of Syrian refugees that are living in camps spread all over the country, with the largest concentration in the Bekaa Valley. Generous steps are being taken to increase the access to formal education, such as offering free public education and opening second shifts in the public schools in the afternoon. Yet barriers, such as child labor and health-related factors like the spreading of some communicable diseases, like Leishmania, are keeping children out of classroom. The present study was done with the aim of investigating the effect of leishmaniasis on the performance and the academic achievement of Syrian refugee children. The results showed varying degrees of knowledge and dealing with the case of leishmaniasis. The disease clearly had an effect on the students' attendance in schools, and by proxy on their academic performance.