Background: Nigella sativa (NS) (black seed), has an extraordinary and wide-ranging healing properties neuroprotective and antioxidant effects. Aging process is commonly associated with a decline in the chemical senses including smell. Aim of the work: To detect a possible improving effect of NS on the histological aging changes of the olfactory system. Material & methods: 15 female albino rats were used and divided into 3 groups (5 animals each): Group I (control adult): 3 months old. Group II (control aged):18 months old. Group III (treated aged): 18 months old, received NS orally at a dose of 40mg/kg/day for 2 months. Specimens from the olfactory epithelium (OE), bulb (OB) and cortex (OCx) were processed for light and electron microscopy. Results: Aging in OE is associated with a reduction in thickness, loss of surface cellular processes, deep nuclear staining and vacuolations. NS treatment improved the OE thickness and nuclear staining and reduced vacuolations. Aged OB and OCx exhibited a reduction in size in mitral and pyramidal cells respectively, with dark staining of their nuclei and reduced cytoplasmic basophilia. NS treatment markedly increased the cytoplasmic basophilia in both mitral and pyramidal cells. The results are discussed in view of the light and electron microscopic results. Conclusion: Use of NS, could be of value in improving the structural changes of the peripheral and central main olfactory organs which occurs in association with aging and results in deficit in the sense of smell.

Background: Tobacco smoking has been identified as an important factor in premature skin aging. Aim of the work: to detect the histological changes occurred in adult male guinea pig thin skin under the influence of low and high doses of nicotine; which constitutes approximately 0.6–3.0% of the dry weight of tobacco. Material &methods: Fifteen adult male pigmented guinea pigs were equally divided into three groups. Group I: control. Group IIA: (low dose nicotine treated; 3mg/kg subcutaneously for 4 weeks). Group IIB (high dose nicotine treated; 6mg/kg subcutaneously for 4 weeks). Specimens from the back thin skin were processed for light and electron microscopy. Results: Nicotine administration revealed flattened dermo-epidermal junction and reduced rete ridges formation. Collagen bundles were disorganized with increased spaces between them. A reduction in the amount of elastic fibers in the dermis were also observed compared to group I. Ultrastructurally, keratinocytes had hyperchromatic nuclei, intracytoplasmic vacuoles, disruption of desmosomal junctions, irregular tonofilaments distribution, increased inter-cellular spaces. These changes were more pronounced with high dose nicotine administration. The epidermal thickness was reduced in low dose nicotine administration. While, high dose nicotine administration revealed increased epidermal thickness compared to the control group. Conclusion: Nicotine induced structural changes of adult male guinea pig thin skin. These changes were more pronounced with high dose nicotine administration.

Background: Tobacco smoking has been identified as an important factor in premature skin aging. Aim of the work: to detect the histological changes occurred in adult male guinea pig thin skin under the influence of low and high doses of nicotine; which constitutes approximately 0.6–3.0% of the dry weight of tobacco. Material &methods: Fifteen adult male pigmented guinea pigs were equally divided into three groups. Group I: control. Group IIA: (low dose nicotine treated; 3mg/kg subcutaneously for 4 weeks). Group IIB (high dose nicotine treated; 6mg/kg subcutaneously for 4 weeks). Specimens from the back thin skin were processed for light and electron microscopy. Results: Nicotine administration revealed flattened dermo-epidermal junction and reduced rete ridges formation. Collagen bundles were disorganized with increased spaces between them. A reduction in the amount of elastic fibers in the dermis were also observed compared to group I. Ultrastructurally, keratinocytes had hyperchromatic nuclei, intracytoplasmic vacuoles, disruption of desmosomal junctions, irregular tonofilaments distribution, increased inter-cellular spaces. These changes were more pronounced with high dose nicotine administration. The epidermal thickness was reduced in low dose nicotine administration. While, high dose nicotine administration revealed increased epidermal thickness compared to the control group. Conclusion: Nicotine induced structural changes of adult male guinea pig thin skin. These changes were more pronounced with high dose nicotine administration.

The vomeronasal organ (VNO) is a chemosensory organ that detects environmental pheromones. The morphology of the 'non-sensory' epithelium (NSE) of the VNO and its lamina propria, as well as how it relates to ageing has received little attention. Histological, histochemical, morphometric and ultrastructural techniques were used to study the morphological structure of the rat NSE in five adult (3 months old) and five aged (2-2.5 years old) male albino rats. In adult rats, the NSE contained dark and light columnar cells with predominance of the latter. The surface of the epithelial cells was covered with microvilli and/or cilia. The lamina propria contained serous vomeronasal glands (VNGs), smooth muscles with numerous variable-sized mitochondria, vessels including lymphatic capillaries and nerve bundles. The following changes were detected in aged rats. The NSE exhibited an increase in number of dark columnar cells. Some cells revealed a prominent cell coat, dense aggregation of filaments in the luminal cytoplasm and appearance of multinucleated cells. Their surface revealed malformed configuration. Large mitochondria (2 μm), formed by fusion, were frequently observed in the smooth muscle cells of the lamina propria. Lipid droplets were frequently detected both in the VNGs acini and in the lymphatic endothelium. Ageing affected both the cells of the tissues and the extracellular matrix.

The vomeronasal organ (VNO) is a chemosensory organ that detects environmental pheromones. The morphology of the 'non-sensory' epithelium (NSE) of the VNO and its lamina propria, as well as how it relates to ageing has received little attention. Histological, histochemical, morphometric and ultrastructural techniques were used to study the morphological structure of the rat NSE in five adult (3 months old) and five aged (2-2.5 years old) male albino rats. In adult rats, the NSE contained dark and light columnar cells with predominance of the latter. The surface of the epithelial cells was covered with microvilli and/or cilia. The lamina propria contained serous vomeronasal glands (VNGs), smooth muscles with numerous variable-sized mitochondria, vessels including lymphatic capillaries and nerve bundles. The following changes were detected in aged rats. The NSE exhibited an increase in number of dark columnar cells. Some cells revealed a prominent cell coat, dense aggregation of filaments in the luminal cytoplasm and appearance of multinucleated cells. Their surface revealed malformed configuration. Large mitochondria (2 μm), formed by fusion, were frequently observed in the smooth muscle cells of the lamina propria. Lipid droplets were frequently detected both in the VNGs acini and in the lymphatic endothelium. Ageing affected both the cells of the tissues and the extracellular matrix.

SUMMARY Nephropathy remains an important complication of diabetes. This work was carried out to evaluate the protective effects of N-thioacetylbiguanidine on the diabetic rat kidney. Fifteen adult male Wistar rats were divided into two groups: Group I, control (n=5) and Group II, diabetic group (n=10). The latter was equally divided into two subgroups: IIa (diabetic control) and IIb (diabetic Nthioacetylbiguanidine treated). Specimens were taken from the renal cortex, processed and examined using light, immunohistochemical, ultrastructural and morphometric techniques. The renal cortices from diabetic animals showed dilated glomeruli and tubules and thickening of the glomerular capillary basement membranes. The proximal tubules revealed partial loss of brush border and deposition of PAS-positive material in some distal tubules. iNOS-immunoreactivity was strongly expressed in the renal tubules and glomeruli. The juxtaglomerular (JG) cells revealed no intra-cytoplasmic secretory granules. The histological changes in renal glomeruli and tubules were improved in N-thioacetylbiguanidine treated group. Use of N-thioacetylbiguanidine characteristically reduced iNOS expression in kidney and renin secretion in JG cells. In conclusion, N-thioacetylbiguanidine is effective in attenuating the histological changes of diabetic nephropathy reaching healing features, which resemble that of a normal kidney.

SUMMARY Nephropathy remains an important complication of diabetes. This work was carried out to evaluate the protective effects of N-thioacetylbiguanidine on the diabetic rat kidney. Fifteen adult male Wistar rats were divided into two groups: Group I, control (n=5) and Group II, diabetic group (n=10). The latter was equally divided into two subgroups: IIa (diabetic control) and IIb (diabetic Nthioacetylbiguanidine treated). Specimens were taken from the renal cortex, processed and examined using light, immunohistochemical, ultrastructural and morphometric techniques. The renal cortices from diabetic animals showed dilated glomeruli and tubules and thickening of the glomerular capillary basement membranes. The proximal tubules revealed partial loss of brush border and deposition of PAS-positive material in some distal tubules. iNOS-immunoreactivity was strongly expressed in the renal tubules and glomeruli. The juxtaglomerular (JG) cells revealed no intra-cytoplasmic secretory granules. The histological changes in renal glomeruli and tubules were improved in N-thioacetylbiguanidine treated group. Use of N-thioacetylbiguanidine characteristically reduced iNOS expression in kidney and renin secretion in JG cells. In conclusion, N-thioacetylbiguanidine is effective in attenuating the histological changes of diabetic nephropathy reaching healing features, which resemble that of a normal kidney.

The vomeronasal organ (VNO), because of its ability to detect pheromones, has an important role in many social and sexual behaviours in mammals. It also mediates defensive behaviours through detection of protein pheromone homologues. A detailed morphological description of the post-natal development of the ‘non-sensory’ epithelium (NSE) of the female rabbit is recorded. Histological techniques were used to study the NSE of the VNO in post-natal development of female rabbits. The study focused on the following post-natal ages: newborn, 1 week, 2 weeks and 1 month (five animals each) beside to two adult animals. The rabbit VNO was surrounded externally by bony capsule and internally by cartilaginous capsule. NSE was pseudostratified columnar partially ciliated epithelium without goblet cells. In addition to basal cells, NSE contained ciliated and three types of non-ciliated columnar cells (dark, pale and light). At birth, dark cells may have primary cilia. By 1 month, the cytoplasm became lighter with less free ribosomes. The pale cells had electron-lucent cytoplasm, which contained a few organelles. Mitotic figures were observed in basal and columnar cells, particularly during the first 2 weeks of post-natal development. Light columnar cells were common during the first week. Numerous leucocytes and a few nerve endings were detected intra-epithelial. Scanning electron microscope revealed a gradual increase in height of microvilli of nonciliated cells. Ciliated cells had cilia and microvilli. Cells were arranged singly, in clumps or in a dense population of cells. The rabbit VNO-NSE had a unique morphological structure.

The vomeronasal organ (VNO), because of its ability to detect pheromones, has an important role in many social and sexual behaviours in mammals. It also mediates defensive behaviours through detection of protein pheromone homologues. A detailed morphological description of the post-natal development of the ‘non-sensory’ epithelium (NSE) of the female rabbit is recorded. Histological techniques were used to study the NSE of the VNO in post-natal development of female rabbits. The study focused on the following post-natal ages: newborn, 1 week, 2 weeks and 1 month (five animals each) beside to two adult animals. The rabbit VNO was surrounded externally by bony capsule and internally by cartilaginous capsule. NSE was pseudostratified columnar partially ciliated epithelium without goblet cells. In addition to basal cells, NSE contained ciliated and three types of non-ciliated columnar cells (dark, pale and light). At birth, dark cells may have primary cilia. By 1 month, the cytoplasm became lighter with less free ribosomes. The pale cells had electron-lucent cytoplasm, which contained a few organelles. Mitotic figures were observed in basal and columnar cells, particularly during the first 2 weeks of post-natal development. Light columnar cells were common during the first week. Numerous leucocytes and a few nerve endings were detected intra-epithelial. Scanning electron microscope revealed a gradual increase in height of microvilli of nonciliated cells. Ciliated cells had cilia and microvilli. Cells were arranged singly, in clumps or in a dense population of cells. The rabbit VNO-NSE had a unique morphological structure.

All-trans Retinoic acid (atRA) is instructive for the development of endocrine pancreas and is an integral component of b-cell induction protocols. We showed that atRA induces glucose-responsive endocrine transdifferentiation of pleomorphic pancreatic ductal adenocarcinoma cells in vitro. This study aimed to detect the role of atRA in improving the histological changes of the pancreas in diabetic rats. Forty young male Wistar rats were used and divided into three groups. Group I: normal vehicle control (N55). Group II: streptozotocin-induced diabetic rats (N520) were followed up at 0.0, 1, 2, and 4 weeks. Group III: streptozotocininduced diabetic rats (N515) treated with atRA (2.5 mg/kg/day), were followed up at 1, 2, and 4 weeks. Specimens from the pancreas were processed for light, electron microscopy and pancreatic insulin mRNA expression. Blood samples were assayed for the levels of glucose, insulin, and total peroxides. In the atRA-treated group, the number of the islets and the islet area significantly increased. Strong insulin-immunoreactive endocrine-like cells were observed nearby the pancreatic acini and the interlobular ducts. Interestingly, insulin-positive cells seemed to arise from pancreatic acinar and ductal epithelium. Ultrastructurally, ß-cells, acinar, and ductal cells restored their normal appearance. Pancreatic insulin mRNA and blood indices were almost normalized. AtRA improved the histological changes of the pancreas and the blood indices in diabetic rats.