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Mucociliary clearance is essential to maintain the defense function of the maxillary sinus; however, no literatures described the age changes in its lining epithelium. Therefore, the current work sought to describe the morphological postnatal age-related changes of maxillary sinus lining epithelium in rats using light, transmission, and scanning electron microscopes. Eighteen albino rats were divided into six groups according to their ages: 2-week-old, 1-month-old, 2-month-old, 3-month-old, adults, and senile rats. One-month-old-rats' group was the first to have recognizable maxillary sinus cavities that were lined by either single flat cellular layer or two distinct epithelial layers. These cells were devoid of microvilli and cilia, none of them showed evidence of differentiation into identifiable cell types. In 2- and 3-month-old rats, the mucosa of maxillary sinus started to be lined with pseudostratified epithelium with apparent increase in both microvilli and cilia. The first indication of goblet cell differentiation was observed in 3-month-old-rats. In the adult rats, the sinuses became completely lined by mature respiratory epithelium. However, in senile rats the epithelium exhibited polyps with clumped cilia and some areas of stratification and desquamation. Goblet cells were scanty and degenerating. The impaired mucociliary components (epithelium, cilia, and goblet cells' mucus) found in young and old ages of the current work might be correlated to human to explain predisposition of rhino-sinusitis in these age groups.

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Background The importance of sleep and the impact of its deprivation on development of brain pathology became a recent subject of interest in medicine. The restorative effect of sleep on the brain and the harmful effects of insomnia have been recently revealed through the discovery of the glymphatic system and its association with sleep. Aim of work Specific objectives are: To detect histological and apoptotic changes in the neurons and dendrites of the cornu Amonis and the dentate gyrus in sleep deprived rats in comparison to rats with undisturbed sleep pattern (control). To detect deposition of neurotoxic metabolites in comu Amonis and dentate gyrus in sleep deprived rats in comparison to controls. Methods Twenty four adult male Albino rats were used in the present experiment. randomly categorized into four equal groups; Group A1 served as the control group, Group .A2 one day sleep deprivation, Group A3 three days sleep deprivation and Group A4 seven days sleep deprivation. They were deprived of sleep using grid over water method where the animals placed over a grid suspended above tank filled with water with free access to food (rat chew) and water. Hippocampai specimens were collected, processed for paraffin blocks and examined by light microscopy. Results there were neurodegenerative signs appeared from day one sleep deprivation, increased by day three and prevailed by day seven. It was confirmed by apoptotic changes detected by caspase 3 immunohistochemical staining. Furthermore, deposition of beta amyloid appeared in rats deprived of sleep and confirmed by congo red stain. Conclusion Adequate sleep is essential for integrity of the newly discovered glymphatic system responsible for clearance of the brain from waste products including the area most involved in learning and memory function; the hippocampus. Correction of SD could be a viable therapeutic strategy to prevent the onset or slow the progression of AD. Recommendations Further characterization of the glymphatic system in humans are required, it may lead to new therapies and methods of prevention of neurodegenerative diseases. Correction of SD could be a viable therapeutic strategy to prevent the onset or slow the progression of AD.