Despite the widespread application of zinc oxide nanoparticles in biomedicine, their use is still a controversial issue. Zinc oxide nanoparticles were reported to have therapeutic benefits. However, they were reported to have toxicological hazards as well. Several studies reported the antibacterial, anticancer, antioxidant, and immunomodulatory effects of zinc oxide nanoparticles. Additionally, zinc oxide nanoparticles were used in sunscreens. Furthermore, the ability to use zinc oxide nanoparticles as an adjuvant treatment to alleviate the toxic effects of chemotherapeutic drugs has been reported. However, zinc oxide nanoparticles were shown to induce toxic effects in different body organs and systems. The affected organs included liver, spleen, kidney, stomach, pancreas, heart and lung. In addition, zinc oxide nanoparticles were reported to adversely affect the neurological system, lymphatic system, hematological indices, sex hormones levels, and fetal development. The toxic effects of zinc oxide nanoparticles were based on their concentration, their dose, the route of their administration, and the time of exposure to those particles. Thus, it is crucial to assess their efficacy and safety to determine their toxicological risks and therapeutic benefits.

Anaphylactic shock is a sudden and serious life-threatening systemic hypersensitivity leading to a rapid, irreversible fatal circulatory collapse. Postmortem diagnosis of fatal anaphylaxis is a very sophisticated task in forensic medicine; it is usually excluded as the cause of death due to lack of autopsy findings. This study aims to find more specific criteria for the postmortem diagnosis of induced fatal anaphylaxis in rats by assessing the levels of total tryptase, histamine,

Cyclosporine is considered one of the common worldwide immunosuppressive drugs that are used for allograft rejection prevention. However, articles that address adverse effects of cyclosporine use on the vital organs such as lung are still few. This study aims to investigate pulmonary toxic effect of cyclosporine in rats by assessment of pulmonary histopathological changes using light and electron microscope examination. Sixty male adult albino rats were divided into three groups; each group consists of twenty rats. The first received physiological saline while the second and third groups received 25 and 40 mg/kg/day of cyclosporine, respectively, by gastric gavage for forty-five days. Cyclosporine reduced the lung and body weight with shrinkage or pyknotic nucleus of pneumocyte type II, degeneration of alveoli and interalveolar septum beside microvilli on the alveolar surface, emphysema, inflammatory cellular infiltration, pulmonary blood vessels congestion, and increase of fibrous tissues in the interstitial tissues and around alveoli with negative Periodic Acid-Schiff staining. Prolonged use of cyclosporine induced pulmonary ultrastructural and histopathological changes with the lung and body weight reduction depending on its dose.