Thyroxine as a stimulator of liver regeneration after partial hepatectomy: an experimental animal study

Twenty six male albino rats were divided into a control group [6rats] [G] exposed to Sham operation and two experimental groups [Gl and G2] of 10 rats each. 2/3 partial hepatectomy [PH] was performed in Gl and T4 was administered orally in a dose of 4mg/kg 10 days prior to PH in G2. Animals were sacrificed 24 hours following PH and Sham operation. Liver sections were immunohistochemically stained for anti-cyclin Dl and anti-VEGF antibodies. Positive reaction was in the nuclei of hepatocytes and in lining of hepatic blood sinusoids respectively. The morphometric determination of the count of cyclin Dl positive nuclei and area% VEGF positive lining of the blood sinusoids was performed in the different groups. Multiple cyclin Dl positive nuclei were detected in liver sections of rats receiving thyroxine prior to PH confirmed by significant increase in the mean count of immuno-positive nuclei as compared to G and Gl. VEGF positive immunoreaction was in the lining of multiple hepatic blood sinusoids on thyroxine therapy proved morphometrically by a significant increase in mean area% in G2 versus Gl. The results showed a stimulating effect of thyroxine on liver regeneration following 2/3 partial hepatectomy evidenced by increased Cyclin D and sinusoidal endothelial VEGF expression

Histological and immunohistochemical study on the protective effect of vidisept eye drops on ultraviolet irradiated cornea of albino rat

The study aimed at investigating the possible protective effect of Vidisept eye drops on corneal epithelial damage induced by ultraviolet radiation [UVR] histologically, immunohistochemically and morphometrically. Sixteen male albino rats were divided into control group [4 rats] and two experimental groups [6 rats each]. The first experimental group [both eyes were exposed to UVR 280 nm for 3 minutes] was subdivided into subgroups I and II. The second experimental group [preapplication of 1 drop of Vidisept before exposure to UVR] was subdivided into subgroups III and IV. Each experimental subgroup included 3 rats, sacrificed after I day [subgroups I and III] and after 3 days [subgroups II and IV] respectively. Corneal sections were stained with H and E and immunohistochemically by cytokeratin [CK] AE [1] /AE [3]. Mean count of dark nuclei, mean area% of CK immunoexpression and mean optical density of CK immunoreaction were determined in corneal epithelial cells. In subgroups I and II multiple corneal epithelial cells with dark nuclei, atypical nuclei, deep acidophilia of cytoplasm and single layer of cells were seen. Stromal edema and vascularization were found. In subgroups III and IV few cells with dark nuclei and minimal stromal edema were seen. Light brown CK immunoreaction was evident in the cytoplasm of the superficial cells of corneal epithelium in control group, subgroups III and IV. In subgroups I and II light and dark brown CK immunoreaction was seen in the cytoplasm of superficial, intermediate and basal cells. Mean count of dark nuclei, mean area% of CK immunoexpression and mean optical density of CK immumoreaction were significantly increased in subgroups I and II. Vidisept proved to be effective in the protection of corneal epithelium against UVR induced damage

Light and electron microscopic study on the effect of training and high cholesterol diet on the skeletal muscle of male albino rat exposed to strenuous exercise

The present study aimed at investigating the effect of training and high cholesterol diet on the skeletal muscle [soleus] of male albino rat exposed to strenuous exercise [SE] immediately and 24 hours after. Eighty eight male albino rats were divided into 2 groups: group 1 given balanced diet and group 2 given high cholesterol diet. Each group was subdivided into control rats not subjected to exercise and experimental group which included untrained and trained rats exposed to [SE] and sacrificed immediately or after 24 hours. Serum triglyceride [TG] and low density lipoprotein cholesterol [LDL-C] were tested. Semithin and ultrathin sections were examined by light and electron microscopes. Mean unclear area and count of sarcoplasmic vacuoles were assessed morphometrically. In group 1, nuclei with peripheral chromatin condensation, darkly stained fibers and electron dense areas were seen in untrained rats immediately following [SE]. Small nuclei with peripheral chromatin condensation, atypically arranged myofibrils, discontinuous A bands, focal loss of Z lines with electron dense particles around and enlarged,mitochondria with destroyed cristae were detected in untrained rat muscles 24 hours following [SE]. Less changes were noticed in corresponding trained rats. Group 2 revealed multiple sarcoplasmic vacuolations. Dark areas, irregular discontinuous myofibrils and small nuclei with peripheral chromatin condensation appeared in untrained rat muscle immediately following [SE]. In addition, small dark nuclei existed 24 hours after [SE]. Highly significant decrease in mean nuclear area and mean count of sarcoplasmic vacuoles existed in untrained and trained subgroups respectively. Dilated cisternae of sarcoplasmic reticulum, enlarged mitochondria with destroyed cristae and irregular focally disrupted sarcolemma were seen in untrained rats. Less changes were detected in corresponding trained rats. Serum [LDL-C] and [TG] showed highly significant increase in group 2 and highly significant decrease in trained subgroups. It was concluded that apoptosis was induced by strenuous exercise exacerbated by hypercholesterolemia and lessened by training

Histological and immunohistochemical study on the rat Kupffer cell in response to short and long term ethanol administration

The present study aimed at investigating the Kupffer cells in the rat liver of both sexes in response to short and long term ethanol administration, as regards multiplicity and CD14 receptor immuno-expression and its relation to the developing damage. Forty eight male and female albino rats were divided into a control group of 12 rats and an experimental group of 36 rats including subgroups I and II [short term ethanol administration] that were given 17.5% ethanol for 1 and 3 days respectively. Subgroup III [long term ethanol administration] was given 34.2% ethanol for 6 weeks. India ink was injected into half the number of male and female control and experimental rats. Liver sections were stained with H. and E. and immunohistochemically using CD14 antibody for the receptors on the surface membrane of Kupffer cells. The count of Kupffer cells, area of CD14 immunoexpression and the optical density of CD14 immunoreaction were assessed. In subgroup II apoptotic cells and in subgroup III hepatocytes exhibiting eosinophilic material and small dark nucleus were found. The changes were in obvious in females. Kupffer cells seen in India ink injected sections revealed nonsignificant difference in their mean count in different groups and subgroups. CD14 immunoexpression appeared as darkly and lightly stained areas in male and female control rats. The immunoexpression and the immunoreaction increased in the experimental subgroups with a remarkable difference between female and male rats. A highly significant increase in the mean area and mean optical density was recorded in subgroup I versus control rats. Also in subgroups II and III versus control rats and rats of subgroup I of the same gender and in experimental female versus male rats. Short and long term ethanol administration led to activation of CD14 receptors on the surface membrane of Kupffer cells, indicating their role in initiation of liver injury