Anatomical variations of the vertebral artery and its relation to the atlas vertebra - Radiological and dry bone study

Vertebral artery (VA) variations are important for diagnostic angiographic procedures. This study aimed to describe the anatomical variations of VA using multidetector computed tomography angiography (MDCTA), and to provide a quantitative and qualitative anatomy of the VA groove in dry atlas vertebrae. The study was carried out on 100 MDCTA images from adult Egyptian individuals (69 males; 31 females) and 50 dry atlas fully ossified and of unknown age and sex. MDCTA films were evaluated for VA origin, level of entrance into foramen transversarium, caliber, and distance from the midline. VA grooves in dry bones were examined for the presence of ponticulus posticus (PP). Inner and outer distances from the midline, width and thickness were measured using sliding Vernier caliper. The results revealed that the left VA arose directly from the aortic arch in 7% of cases and was absent in 2% of cases. Atypical entry of VA into foramen transversarium was through C5 (4.5%), followed by C7 (1.5%), then C4 (1%). The left vertebral arteries with direct aortic origin were more medially located than the left arteries with subclavian origin (p=0.005). The mean diameter was significantly greater on the left (3.67±1.07 mm), as compared to the right side (3.36±0.93 mm) (p=0.038). PP was detected in 47% of cases in radiological images and 96% of dry bones. It could be concluded that the most important variations of VA were the aortic origin of the left VA and abnormal entry through transverse foramina. PP was a common variation in atlas vertebrae. These variations should be taken into consideration during radiological and orthopedic procedures

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Age-related alterations in the lacrimal gland of adult albino rat: a light and electron microscopic study.

BACKGROUND: Age related changes in the lacrimal gland are associated with alterations in the structural organization and functional response in the gland of diverse mammalian species. Dry eye syndrome is one of the most common ocular problems in the world especially in old age. It results when the lacrimal gland fails to secrete proteins and fluid in sufficient quantity or appropriate composition. AIM OF THE WORK: The present study is designed to demonstrate the influence of aging on the structure of the lacrimal gland of albino rat and to provide a morphological basis to explain the pathogenesis of the dry eye syndrome with ageing. It also aims to carry out a comparative analysis of age-dependent changes in male and female rats and to address how the lacrimal gland ages in each sex. MATERIAL AND METHODS: Eighty albino rats were used in this study. The animals were divided into two age groups, young adult and senile. Tear secretion was measured using a modified Schirmer test. Corneal impression cytology of the anesthetized rats was done. The glands were subjected to gross morphologic examination, microscopic examination using H&E, PAS, Masson's trichrome and Giemsa stains. Electron microscopic examination was done in addition to quantitative histomorphometric estimations included acinar density, ductal count and mast cell count. RESULTS: Light microscopic examination of the lacimal glands of the senile rats revealed different pathological changes. These included acinar, ductal as well as stromal changes. Electron microscope examination of the lacrimal gland of the senile group showed a decrease in the electron dense secretory vesicles, mitochondrial swelling and lipofuscin-like inclusions were frequently seen in the cytoplasm of acinar cells in senile rats. CONCLUSION: The structural changes in the lacrimal glands of senile rats were associated with reduction in tear secretion as well as alterations in corneal epithelium. Gender difference in lacrimal gland structure was recorded.