Effect of temporary submandibular duct-ligation on the myoepithelial cells in albino rat. A light and electron microscopic studies

The duct of the right submandibular gland was doubly ligated with metal clips to study the effects of duct ligation and ligature removal in albino rat submandibular gland to elucidate the relationship between duct ligation and removal of the ligature and to determine whether proliferation of myoepithelial cells occur in atrophic rat submandibular glands. Twenty adult male albino rats were used in this study. Rats were divided randomly into 3 main groups: a submandibular gland atrophy group [Ligated Group] in which the right main submandibular duct was ligated for 1, 2 and 4 weeks; a recovery group in which duct ligation was in place for 2 weeks and then removed and the rats were sacrificed after 2 weeks and the 3rd group was not subjected to operation and used as control group. At the assigned date, the animals were sacrificed. The right submandibular glands were thoroughly-dissected and removed. Specimens of the gland were cut at 6-8 micro m thickness and stained with haematoxylin and eosin. Other specimens of the gland were taken and prepared for electron microscopy study. Duct ligation of the submandibular gland was accompanied by progressive atrophy of the gland. After 4 weeks of duct-ligation, light microscopy showed that the acini became atrophied and contained few secretory granules. There was dilated inter-lobular and intralobular ducts that lined by cuboidal flat cells. The inter-lobular connective tissue was increased in thickness. Persistent myoepithelial cells were also found in atrophic rat sumandibular gland. After removal of the ligature, the gland revealed histological evidence of regeneration and persistent myoepithelial cells. All cellular components manifested recovery and became similar to the control condition. The present observations also suggest that ligation of the main duct of the rat submandibular gland produces a pronounced atrophy that is reversed upon ligature removal

Thyroid gland volume in infants, children and adults from Sharkia governorate: Ultrasonographic study

Thyroid ultrasonography has proven a useful and practical method for the assessment of thyroid size.Thyroid ultrasonography were carried out first to determine the standard thyroid volume in normal children and adolescents.Second to establish a standard growth curve of thyroid volume with respect to age, sex, height and weight. We effected sonographic examination of 220 patients [110 females and 110 males] from Sharkia governorate aged between 1 day and 18 years and body weight from 2.0 kg to 90.0 kg. In this study the volume of thyroid glands in newborn is 0.8 ml +/- 0.21 ml. Mean thyroid volume was found 5.5 ml +/- 0.61 ml in 6-8 years old, while it was 17.5 ml +/- 2.35 ml in 14-16 years old male and 15.3 ml +/- 2.51 in 14-16 years old female. The right lobe was larger than the left one in all age groups. Thyroid volume determined by ultrasound in control children increased with age up and was correlated with height and body weight

Role of zinc administration on the effect of lead on the ovary of adult female albino rats. Histological and histochemical study

The risk of lead exposure and lead poisoning has been a major area of concern for several years mainly for women in both industrialized and developing counteries. The present study was designed to investigate the effect of chronic lead exposure on the ovary of adult female albino rats, and the role of zinc supplementation. Thirty adult female virgin albino rats were utilized in this study. They were classified into three equal groups, the 1[st] group was administered 1ml dist. Water orally and served as control group. The 2[nd] group [Lead - treated group] was administered lead acetate at a dose of 50 mg/kg b.wt. orally. The 3[rd] group [Zinc - supplemented group] was administered lead acetate as in tile 2[nd] group and zinc sulphate at a dose of 1mg /kg b. wt. orally. At the end of three months, animals were killed and ovaries were dissected out, fixd in 10% formol saline and processed for histological and histochemical studies using Hx, E, Masson Trichrome, PAS and Methyl Green and Pyronine stains. Tile histological and histochemical results revealed that chronic lead exposure resulted in degenerative changes in the ovaries and these changes were ameliorated with coadministration of zinc. This protective effect of zine could be attributed to differential distribution of lead, either because of competition between lead and zinc or displacement of lead by zinc

Morphometry of the lens development in albino rat

This study analysed pattern of growth of the lens by measuring the lens surface area, circumference and diameters in relation to the eye ball in albino rat at ten stages, 12, 13, 14, 16, 18 and 20 days of embryonic development and 1, 7. 14 and 28 days of post-natal development. We used the recent technique DIAD [Digitizing and Image Analyzing Device] and runing the autocad program. Surface area of the lens increases during different stages of development and reachs its maximum percentage in relation to the eye ball during the 4[th] and 5[th] stages. Surface area of the lens at 10[th] stage is more than 60 folds than the 1[st] stage. Transverse diameter of the last stage is more than 8 times of the first stage. Anteroposterior diameter is nearly equal the transverse diameter up to the 5[th] stage then it declines. Significant age-related linear increas were found for all parameters