Background: Many therapies to treat cancer are gonadotoxic and can lead to infertility. New strategies to diminish the side effects and protective plans during and after chemotherapy are needed. Therefore, bone marrow mesenchymal stem cells (BM-MSCs) as a novel solution were investigated against doxorubicin (Dox)-induced toxicity in rat testes. Methods: Forty male albino prepubertal rats were divided into four groups, 10 rats per each group. The first was injected intraperitoneally with saline as control. The second group was injected intravenously with a single dose of BM-MSCs (2 × 10 6 cells). The third was injected intraperitoneally with a single dose of Dox (5 mg/kg b.wt). The fourth was injected with both Dox and BM-MSCs as previously mentioned. Rats were cohabited each separately with an untreated adult female after 8 weeks of treatment to examine Dox effects on male's fertility. Results: BM-MSCs counteract the deleterious effects of Dox on body, testicular weight as well as sperm quality by increasing sperm concentration and reducing the rate of abnormal sperm. BM-MSCs reduced significantly the testicular oxidative stress by reducing the elevated level of malondialdehyde and increasing the antioxidant capacity. Histologically, the testicular atrophy, severe damage of spermatogenesis and the significant reduction of the diameter and germinative cell layer thickness of the seminiferous tubules caused by Dox were significantly recovered after administration of the BM-MSCs. Conclusion: BM-MSCs have a significant role in restoring the structural efficiency of male reproductive system in rats after Dox treatment. K E Y W O R D Sbone marrow derived-mesenchymal stem cell, doxorubicin, male fertility, oxidative stress, testicular toxicity

Background With the increasing production and applications of silver nanoparticles (AgNPs), they can be released into the air, water, and soil environments leading to direct exposure to human beings. On this, the current study revealed the physiological, histological, and genotoxic effects of the green biosynthesized AgNPs using two methods; lemon juice or saponin reduction on the maternal and fetal tissues. Methods Twenty‐eight pregnant female rats were divided into four groups (seven/group) and orally administrated the corresponding treatment doses once daily from the first to the 19th gestational day. The first group was administered distilled water as a control. The second group was administrated saponin. The third was administrated AgNps. The fourth was administrated saponin‐loaded silver nanoparticles (Sn‐AgNPs). Results Compared with the control group, the serum of pregnant rats treated with saponin, AgNPs, and Sn‐AgNPs exhibited significant alterations in liver and kidney function parameters. In addition, maternal hepatic and renal tissues showed elevated oxidative stress, with a significant increase in the comet parameters. Histologically, both mothers and fetuses showed changes in the liver and kidney tissues. Conclusions Green synthesized AgNPs have toxic effects on maternal and fetal tissues. Sn‐AgNPs revealed an increase in the transfer, accumulation, and toxicity.

A mathematical model for the prediction of pollutant emissions from motor vehicles is presented. The model is based on the numerical solution of the three-dimensional equation representing the mass conservation of dilute diffusing species. The variation of wind speed and eddy diffusivity with height is taken into consideration. The three-dimensional diffusion equation is solved numerically. The numerical procedure involves the discretization of the partial differential equation using the finite volume approach. The resulting set of discretization equation is solved iteratively using a fully implicit solution procedure. Furthermore, field measurements of the concentrations of nitrogen oxide in the downtown area of Cairo were conducted. For this purpose, a mobile air pollution laboratory fitted with gas analyzers, particulate matter sampler and equipment for the measurement of wind speed and direction has been used. This laboratory is also fitted with data recording and monitoring facility. The mathematical model is tested by comparing the computed pollutant concentrations with the experimental data obtained from the field measurements in the Cairo Metropolitan Area.