Melatonin prevents cyclosporine- induced hepatotoxicity in rats

Cyclosporine A [CsA] is a widely used immuno-suppressive agent that is implicated in the formation of free oxygen radicals. Melatonin is known to be a free radical scavenger and an antioxidant agent. This study was designed to investigate the effects of melatonin on CsA-induced liver damage by histopathological examination. Thirty-two male rats of Sprague-Dawley origin were divided into 4 groups of 8 and treated for 28 days as follows: group 1 received daily doses of 0.1 ml/kg olive oil s.c.; group 2 received 4mg/kg of melatonin; group 3 received 10mg/kg CsA diluted in 0.1 ml/kg olive oil; group 4 was treated with 4 mg/kg melatonin i.p. and 10 mg/kg CsA s.c. Finally, the rats were sacrificed by terminal anesthesia, and liver tissue specimens were processed for light microscopy, stained with HE and examined under a light microscope. Specimens of the control group showed normal liver histology, whereas group 3 showed major histopathological changes, such as cytoplasmic vacuolization, dilatation of the sinusoids, apoptosis and many mitotic figures. In group 4, the normal histology of the liver was preserved, although apoptosis, mitotic figures and cytoplasmic vacuolization were still infrequently observed. Nevertheless, there were significant differences between group 2 [melatonin] and group 3 [CsA] and between group 3 [CsA] and group 4 [CsA + melatonin] concerning these 3 parameters [vacuolization, sinusoidal dilatation and apoptosis]. The results of this study suggest that CsA-related liver toxicity in rats could be significantly reduced by melatonin adminstration

The Influence of Cigarette Smoke on the Epithelium of the Vestibule: an Electron Microscopic Study

It is known that cigarette smoke induces cytological alterations on the respiratory and olfactory mucosa of the nasal cavity. We evaluated whether cigarette smoking had adverse effects on the epithelium of the vestibule, in the absence of any published ultrasutructural studies. We evaluated ten patients suffering from septum deviation, eight of whom were long-term smokers. While each layer of the epithelium obtained from the non-smokers consisted of a homogeneous cell population, each from the long-term smokers consisted of a heterogeneous cell population. The most prominent changes occurred in the shape and size of the cells and nuclei, the number and length of the cytoplasmic projections, the number and distribution pattern of the desmosomes, and the width of the intercellular spaces. We concluded that cigarette smoke produces hyperplastic and dysplastic changes, important factors related with cancer development, on the epithelium of the vestibule.