Effect of chronic lead exposure in various doses on the pyramidal cell neurons of the developing cerebral cortex in young rats [light and electron microscopic study]

Lead represents a toxin which affects the developing nervous system with neuro-behavioural deficits. The present study was planned with the aim of studying the morphological changes that might occur in the cerebrum of the young rats in response to two different doses of the lead for 3 months, and discover whether these changes are reversible or irreversible. Fifty young albino rats, aged 4-5 weeks, were used in the present work. They are classified into 3 groups: a control group [10 rats], group "A" [20 rats] received a low dose of lead acetate for 3 months, and group "B" [20 rats] received a high dose of lead acetate for 3 months. Ten rats of both groups "A" and "B" were sacrificed one month after the last given dose of lead [ie. recovery animals]. The cerebral cortex of the young rats of the group "A" showed that pyramidal cell neurons are little in number. Some of them are atrophic and other showed either degenerating mitochondria and dilated Golgi apparatus or ill-defined cytoplasmic organelles. Also, there is obvious perivascular oedema. In addition, most myelinated axons showed vacuolation of their myelin sheaths. The cerebral cortex of the young rats of the group "B" showed that most of the pyramidal cell neurons are distorted, with irregular nuclear membrane, proliferative endoplasmic reticulum, dilated Golgi apparatus and degenerating mitochondria. Also, wide-spread gliosis and extensive pericellular oedema were evident. Most myelinated axons showed vacuolation of myelin sheaths, and vacuolated or ill-defined axoplasm. The cerebral cortex of the recovery animals of the group "A" showed nearly complete recovery, while that of the group "B" showed incomplete recovery in the form of perivascular oedema and abnormal myelinated and non-myelinated axons

Alterations in the ultrastructure of the liver in chronic lead intoxication in the adult albino rats

In the present work, the effect of chronic lead intoxication in two doses [5 mg/kg body weight, as therapeutic dose and 10 mg/kg body weight as sublethal dose] on the ultrastructure of the rat liver was studied. The rats were classified into three groups: one control group [10 rats], experimental group A [20 rats] who received a therapeutic dose of lead acetate orally for six months, and experimental group B [20 rats] who received a sublethal dose of lead acetate orally for six months. Ten rats of both groups A and B were sacrificed one month after the last given dose [recovery rats]. Small slices of the liver of the rats of all groups were processed for electron microscopic examination. The livers of group A rats showed a few pathological changes in the form of proliferation of both rough and smooth endoplasmic reticulum, multiple areas of glycogen depletion with a few lysosomes and fat droplets. The liver of group B rats showed marked pathological changes in both hepatocytes and Van Kuppfer's cells. The cytoplasm of the hepatocytes showed intracytoplasmic vacuoles and a few degenerative granules. The Von Kuppfer's cells showed pale degenerated cytoplasm, intra-cytoplasmic and degenerated electro-dense granules. The recovery animals of group A showed good recovery, while those of group B showed only partial recovery

Ultra-structural changes induced in rat kidney by chronic administration of lead acetate

Lead is a widespread environmental contaminant, found in air, canned food, drinking water and paints, creating environmental pollution. Lead is capable of damaging vital organs especially the kidneys because it is the main route of lead excretion. The purpose of the present work was to determine the ultra-structural effects of lead acetate on the kidneys of albino rats, who are given lead acetate in their drinking water through orogastric intubation in both therapeutic [group A] and sub-lethal [group B] doses for 6 months.The glomerular capillary wall in the kidneys of group A rats showed mild changes in the form of partial fusion of the secondary foot processes of podocytes, while the kidneys of group B rats showed marked changes in the form of diminution of fenestrated endothelia and marked reduction of secondary foot processes of podocytes. The proximal convoluted tubules in the kidneys of group A rats showed mild changes in the form of absence of both basal striations and brush border with disorientation of deep basal infoldings of the cell membrane. The proximal tubules in the kidneys of group B rats showed marked changes in the form of multiple intracytoplasmic vacuoles, multiple lysosomes, multiple degenerated mitochondria and irregular thickened basement membrane. Kidneys of animals left to recover in group A showed complete recovery, while only partial recovery was detected in group B

[Case report]anatomical variations of the branching pattern of the left coronary artery in human heart

The present study was performed to assess the variations in the branching pattern and dimensions of the various branches of the left coronary artery and to discuss various names given to the third and fourth branches. Hearts of forty cadavers were used and their coronary arteries were examined by dissecting the epicardium. Dissection was performed at the Anatomy Laboratory of the College of Medicine, King Faisal University, Dammam, K.S.A., between October 2003 and July 2004.There were 2 branches [bifurcated left coronary artery] in 18 hearts, 3 branches [trifurcated left coronary artery] in 16 hearts, 4 branches [quadrifurcated left coronary artery] in 4 hearts and 5 branches [quintifurcated left coronary artery] in 2 hearts. Diameter and length of different branches were noted Upon examination of the dimensions and important variations of the branches of the left coronary artery, the importance of the intermediate artery has been noted. Various names given to this artery in the literature should be replaced with the name "intermediate artery"

Effects of tamoxifen on the adult rat liver [histological, histochemical and ultrastuctural study]

The effect of tamoxifen on the liver of adult rats was studied by histological, histochemical and ultrastructural studies. Twenty five adult rats, of both sexes, were used in this study. The animals were divided into two groups: The first group [5 animals] was used as a control group and the second group [20 animals] received tamoxifen tablets [40 mg/kg body weight] daily for 3 months. Histological results revealed severe hydropic degeneration in the centrilobular and midzonal areas of the hepatic lobules, cellular infiltration and mild dilatation of some blood sinusoids. The histochemical results revealed marked decrease of succinic dehydrogenase enzyme activity, marked increase of both alkaline and acid phosphatase enzymes activity and marked decrease of DNA contents of the liver cells. Ultrastructural studies revealed some ultrastructural degenerative changes of the cytoplasmic organelles including proliferation of smooth endoplasmic reticulum, fragmentation of rough endoplasmic reticulum and degeneration of the mitochondrial matrix. The present study suggested that careful assessment of the risk of chronic tamoxifen administration on the liver function tests should be considered in the prophylactic use of the drug

Morphological and radiological study of the Egyptian calcaneal articular facets and trabecular pattern of the calcaneus

Three hundred normal adult dry calcanei were collected from different anatomical departments in Egypt. The calcanei were subjected to study the morphology of the articular facets. Also, radiological examinations and longitudinal sections were done to study the trabecular patterns of the calcanei. According to the morphology of calcaneal articular facets, type I calcanei represented 63% of the total number of bones and showing one continuous facet situated on the sustentaculum tali and extending to the anteromedial corner of the distal part of the calcaneus. This type divided into two subtypes according to the absence or the presence of the constriction i.e. subtype Ia [40%] and subtype Ib [23%]. Type II calcanei represented 30% of the total number of bones and showing two articular facets which were presented with variable degree of separation between the two facets. Accordingly, this type divided into three subtypes i.e. subtype IIa with narrow separation, subtype IIb with moderate separation and subtype IIc with wide separation. Type III calcanei represented 5% of the total number of bones and showing a single facet on the sustentaculum tali with absence of anterior talar facets. Type IV calcanei represented 2% of the total number of bones and showing a single confluent facet due to fusion of medial, anterior and posterior talar articular facets