Anatomical variations of the circle of Willis in males and females on 3D MR angiograms

The objective of the present work was to study the anatomical variations of the circle of Willis as regard its component vessels and their average diameters in a sample of adult Egyptians and to detect any sex-related differences in these variations. One hundred and twenty adult patients were observed [60 males and 60 females]. They all had problems unrelated to any ischemic or vascular diseases, so they were considered as healthy control, concerning the morphology of the circle of Willis. In addition, ten cadavers' brains were obtained from the Anatomy department, Faculty of Medicine Ain Shams University for examination of the circle of Willis and for detection of any variations. The anatomical variations of the anterior part, posterior part and completeness of the circle were inspected. Also, the diameters of all component vessels were assessed. The results indicated that, the anterior part of the circle was completed in 70% males and 75% females of the study sample. No statistically significant difference was detected between sexes. The most common variant of the anterior part was the single anterior communicating artery followed by the hypoplastic or absent anterior communicating artery. The posterior part of the circle was completed in 48% males and 58% females. The most common variant was the bilateral posterior communicating arteries, followed by the unilateral posterior communicating artery. An entirely complete circle was found only in 45% of the entire population; and it was higher in the females than in males. The vessels diameters were smaller in the females than in the males, except for the diameter of the posterior communicating artery. Cadavers' examination revealed six cases with complete circle, 3 cases of unilateral fetal posterior communicating and one case of absent posterior communicating artery. The present study showed the amazing great variability of the anatomy of the circle of Willis in asymptomatic persons. Nevertheless, there were no marked differences between both sexes in most of the components and the mean diameters of the circle. Therefore, these anatomical variations have to be considered during radiological interpretation and would be reported in the current anatomy text to be aware of all these normal variations

experimental study of the effects of nicotine on the intervertebral disc

Clinically it had been noticed that a large proportion of patients presenting with low back pain are smokers. Therefore, in this experimental study the histological effects of nicotine on the lumbar intervertebral discs of the rabbits was investigated. Eighteen rabbits were divided equally into 3 groups, Group I [a and b]; as control. Group 2 injected intraperitoneally by 5000 ng/kg nicotine daily for 4 weeks. Group 3 injected intraperitoneally by 5000 ng/kg nicotine daily for 8 weeks. The selected dose produced blood nicotine levels equivalent to those found in heavy smokers [30 cigarettes / day]. Light and electron microscopic studies revealed that nicotine injection showed a variety of histological changes, which were not observed in the control group. This includes appearance of spaces within the nucleus pulposus and separation from the adjacent fibrous lamellae in the annulus fibrosus. Also loss of the regularity of the multilayered structure of the annulus fibrosus, and excessive inclusions associated with vacuoles which continue with the rough endoplasmic reticulum within the chondrocytes. Disc degeneration was more marked in rabbits injected with nicotine for 8 weeks [G3] than in those injected for 4 weeks [G2]. It could be concluded that the disc degeneration is more common among smokers and is correlated with the duration of exposure to nicotine

Assessment of the influence of aging on the olfactory epithelium of rabbits: light and electron microscopic study

The present work was carried out to study the olfactory epithelium of rabbits in different ages and to compare age changes in the anterior and posterior areas of the olfactory mucosa. Twelve male Balady rabbits were used and they were divided equally into three age groups, group [1] 3 month old, group [2] 12 month old and group [3] 36 month old. The animals were sacrificed and the olfactory mucosa was peeled from two fixed parts in each group. Part 1: the posterior area of the roof of the nose and Part 2; the anterior upper area of the nasal septum. In group 1, the two examined parts of the olfactory mucosa were similar. The olfactory mucosa was composed of olfactory epithelium resting on a thin basal lamina and lamina propria that was characterized by the presence of Bowman's glands. The olfactory epithelium was composed of olfactory receptor neurons, supporting cells, microvillar cells that occupied the upper and the middle zones of the epithelium and basal cells in the basal zone of the epithelium. In group2, some degenerative changes were encountered in the olfactory epithelium of the two parts, but the anterior part was more affected than the posterior part. In the posterior part, the thickness of the epithelium and the cell population appeared within normal. However, in the anterior part, the thickness of the epithelium and the cell population demonstrated significant decrease. In group3, there were more degenerative changes than those of group 2. The olfactory mucosa from both parts suffered equally from severe degeneration. The most striking feature was replacement of wide areas of the olfactory epithelium with respiratory epithelium. Other areas showed many degenerated cells with significant reduction in the thickness of the epithelium. The presence of Bowman's glands was still characteristic to the olfactory epithelium. From the present study, it could be concluded that the olfactory epithelium was subjected to natural degenerative changes, which increased steadily with age. These changes began firstly in the anterior exposed areas of the epithelium and with the progress of age both areas were equally affected

study of the effect of hydralazine hydrochloride [apresoline] on the myocardium and renal cortex of the adult balady rabbits

In the present work, the effect of Apresoline on the myocardium and on the renal cortex of adult 18 male balady rabbits was reported. Administration of Apresoline in group 1: that received 5 mg / kg bw daily for 3 days produced sever effect on the heart in the form of wide separation between the muscle fivers, extravasated blood, wide areas of loss of striations and lysis of the myofibrils. When the drug was given in the therapeutic dose [0.5 mg / kg Bw] the effect of the drug increased progressively with the increase in the duration of intake. In group 2: that received the during for 2 weeks, some cardiac muscle fibers showed slight degeneration in the form of loss of striations, which were replaced by granular formation. Few mitochondria were degenerated. In group 3: that received Apresoline for 4 weeks, marked degeneration in the myofibrils in the form of wide areas of loss of striations that were replaced by granular formation were obvious. The sarcoplasm showed degenerated and elongated mitochondria, as well as autophagosomes and dense bodies. Also extravasted blood between the muscle fibers was apparent. The renal cortex suffered also from the treatment with Apresolin, but to a lesser degree than the heart. In group 1: Many proximal convoluted tubules were edematous with obliteration of their lumina and other were degenerated, but the distal tubules and the renal corpuscles appeared normal. In group 2: there were some inflammatory cells, little widening the capsular space and some proximal tubules were slightly dilated. In group 3: some renal corpuscles were degenerated with marked widening in the capsular spaces. Many proximal tubules were dilated with partial loss of their brush borders. Also, extravasated blood and degenerated mitochondria were prominent