effect of low level laser therapy on wound healing

The present study was performed to evaluate the effects of low level laser therapy [LLLT] on wound healing and to compare between the effects of two types of laser on this process. Forty-five albino rats [200-250 gm body weight] were used and divided into three equal groups [A; B; C,]. 2x2 cm skin flaps were removed at the back, on both sides, under ketamine Hcl-anaesthesia, in all rats. Post-wounding, the animals of groups A, B were irradiated by Helium-Neon [He-Ne] and Diode Laser, every other day, for twenty days, respectively. The animals of group C were not irradiated and served as controls. On the 3[rd], 10[th] and 20[th] days after irradiation, five rats from each group were sacrificed. The skin defects were excised, fixed in 10% neutral formalin and processed to obtain 6mm thick paraffin sections stained with Hx and E and Mallory stains. The percentage of wound closure was calculated using the MATLAB 6 computer program. Furthermore, histological evaluation and scoring was preformed regarding epithelialtzation, cellular infiltration, granulation tissue formation, collagen deposition and vascularity. The data were statistically analysed for the test of significance, compared to the control values. On the 3[rd] day post-wounding, the control wounds were covered by dirty crusts under which there were heavy cellular infiltration, vascular congestion and few collagen bundles. After He-Ne Laser, there were markedly dilated capillaries, cellular infiltration and an excess amount of collagen fibers. After Diode Laser irradiation, markedly dilated, congested capillaries, cellular infiltration and regularly arranged collagen fibers were encountered, under the crust. After 10 days, there were dilated, congested capillaries, moderate cellular infiltration and irregularly arranged collagen bundles, in the control, non-irradiated wounds. After He-Ne Laser, the granulation tissue contained proliferating, congested blood capillaries, scattered fibroblasts and more or less regularly arranged collagen bundles. After Diode Laser, the granulation tissue lodged numerous dilated, congested capillaries, mild cellular infiltration, and regularly arranged collagen bundles with intervening fibroblasts. Significant wound closure and histological scoring were recorded in laser irradiated groups, compared to the control one, and in the Diode treated group, compared to He-Ne treated one. Twenty-days post-wounding, the skin wounds healed by scars formed of coarse irregularly oriented collagen bundles, covered by irregular epithelial surfaces, in the control group. After He-Ne. there was complete healing with more or less regularly oriented collagen bundles and regular superficial epithelium. However, Diode Laser resulted in a complete healing process with well-combed collagen bundles and regular, healthy coveting epithelium. Highly significant measurement were recorded in laser treated groups compared to the control one. In addition comparison between those after Diode Laser were highly significant, compared to He-Ne data. It could be concluded that laser irradiation could enhance wound healing without deformed scars. It could be also emphasized that Diode Laser was more effective than He-Ne in this respect

Effect of reperfusion after haemorrhagic ischaemia on the rat jejunal villi

This study was done to evaluate the ischaemtic lesions in the rat jejunal villi and the effect of allopurinol on such lesions, after the induced haemorrhagic shock. Thirty-five adult rats [200-250gm] were used. They were arranged into three groups, the first which [5 rats] served as a control while the remaining two [A and B 15 rats each] were utilized in the experiment. The rats in the experimental groups were anaesthetized with pentabarbital sodium and through the femoral vein 30 ml/kg of blood were withdrawn in a sterile heparinized syring and left for 2 hours then reinfused again. The rats of group B were given 50 mg / Kg allopurinol after blood withdrawal. The same dose was injected daily untill sample collection. Five rats from each experimental group were sacrificed 2 hours, 48 hours and five days after blood reinfusion, in succession. Samples from the jejunum were taken and processed to obtain Hx, E stained paraffin sections as well as ultrathin sections for E/M study. A loop of jejunum was opened and its mucosa was scraped, weighed, minced and homogenized in phosphate buffer [pH 7.4] and the supernatant was analyzed for the level of malondialdehyde [MAD] in the jejunal mucosa. The height of jejunal villi, the number of goblet cells over them as well as the level of [MDA] in the experimental groups were statistically analyzed for the test of significance as compared to the control. There was a significant shortening of jejunal villi, a concomitant decline in goblet cell number over them in the animals of group A compared to control. There was also a significant elevation of [MDA] level in group A as compared to the control. The hight of jejunal villi, the goblet cell number and the level of [MDA] in group B showed no significant changes when compared to control. Two hours after blood reinfusion, in group A, the tips of jejunal villi got broad and their covering cells became short with pyknotic nuclei. The underlying lamina propria showed subepithelial spaces and lymphocytic infiltration. The microvilli on the surface of absorptive cells were short, distorted and lacked their filamentous coat. There was also dilatation of rough and smooth endoplasmic reticula and swelling of mitochondria which possessed disrupted cristae. After 48 hours there were extensive mucosal lesions manifested as sloughing of the degenerated epithehum on the tips and lateral sides of the villi, while the lamina propria lodged wider subepithelial spaces, marked lymphocytic infiltration and haemorrhage, in some areas The absorptive microvilli were noticeably distorted while the cytoplasm contained markedly dilated endoplasmic reticulum, small distorted mitochondria, lysosomes and cytoplasmic vacuoles. Five days after blood reinfusion, in group A, the jejunal villi became denuded and some of them remained as ghosts. The lumen of the jejunum contained detached villi and necrotic materials. There were also marked necrosis and disintegration of the lamina propria. The remaining adsorptive cells lost their microvilli and their cytoplasm was disintegrated with distorted organdies, many vacuoles and lysosomes. After allopurinol treatment, in group B, the light and electron microscopic features of the jejunal villi and their covering cells were more or less similar to the control except for some lymphocytic infiltration. It could be concluded that the destructive effects of blood reinfusion in haemorrhagic shock on the jejunal villi could be alleviated by allopurinol administration

Morphometric study of the mucous cells in albino rat zymogenic units

The present study was carried out to throw light on the morphometric and ultrastructural changes in the different mucous secreting cells in the rat zymogenic units during cellular migration along the zymogenic units. Twenty adult albino rats [200 -250 gm] were used. The animals were perfused through the left ventricle, under Ketamine hydrochloride anaesthesia [45 mg / kg], with lactated Ringer's solution followed by a mixture of 2.5% gluteraldehyde and 2% paraformaldehyde in 0.1 M cacodylate buffer [pH 7.4]. Fine fragments were taken from the fundus of stomach fixed in the same mixture, post fixed in osmium tetroxide, dehydrated in alcohols and propylene oxide, and embedded in Epon. Semithin sections were cut by a glass knife, stained by toluidine blue and used for morphological study and counting of pit and neck mucous cells. Ultrathin sections were cut also with glass knife, stained with uranyl acetate and lead citrate, examined by JEOL 100S E / M. The pit region was arbitrarily divided into low, mid, high pit as well as pit top segments. The neck was similarly divided into high and low segments. The number of cells in these different pit and neck segments was counted in longitudinal sections of twenty zymogenic units for each animal. The size of secretory granules, and mitochondria were measured in 6 micrographs from different units for each cell type. The data obtained from the pit segments were statistically analyzed for the test of significance as compared to the low pit values, those of low neck region obtained from the high neck ones, in the different pit regions as compared with the low pit segment. The low pit cells showed two rows of ectoplasmic secretory granules with dense cores while their cytoplasm contained supranuclear Golgi apparatus with prospectory vesicles at its trans-face, numerous mitochondria few rER cisternae and many free ribosomes. In the cell of the mid pit there were more raws of secrtory granules with diminution of the free ribosomes. In the high pit cells, the ectoplasm was full of many rows of secretory granules, while the free ribosomes were little in amount. A well developed Golgi apparatus with prosecretory vesicles at its trans face was also evident in these cells. The cells at the pit top had few ectoplasmic secretory granules, rounded pale mitochondria, few rER cisternae. The degenerating pit top cells were characterized by the appearance of several clear spaces in the cytoplasm, their nuclei became condensed and irregular while the ectoplasm housed few, ovoid secretory granules; few of which had dense cores. The remaining cytoplasm contained dilated rER cisternae and pale mitochondria. The completely degenerated pit top cells became separated from the adjacent ones by wide intercellular spaces, their dense cytoplasm contained ghosts of mitochondria, rER and scattered lysosomes. Statistically, there was a significant decrease in the number of cells, a significant increase in the size of secretory granules and a significant decrease in the size of mitochondria in all pit segment cells as compared with the low pit ones. The secretory granules of the high neck cells exhibited irregular cores while the cytoplasm showed long rER cisternae, scattered free ribosomes, Golgi stacks and mitochondria. In the low neck cells the granules possessed cores of variable electron density and the rER cisternae surrounded the nucleus. Statistically there was a significant increase in the number of cells in the low neck segment, as compared with the high neck ones. There was also a significant increase in the sizes of both secretary granules and mitochondria in the low neck cells as compared with those in high neck segment. At the border between neck and base, prezymognic cells containing rounded secretary granules with more electron dense material, were encountered. It could be concluded that the activity of pit cells increased as we go up to its high part and decreased at the pit top where they degenerated and became extruded into the gastric lumen. On the other hand, the neck cells became more active as they descended down to the base to be transformed into zymogenic cells

Electron microscope study of the parietal cells in mice stomach

The intent of this study was to clarify the ultrastructural and morphometric changes in mice parietal cells during different stages of differentiation and alteration. Fifteen adult mice were anaesthetized intraperitonealy with sodium pentabarbital [35 mg / kg] and perfused through the left ventricle with a mixture of 2.5% glutaraldehyde and 2% paraformaldhyde in cacodylate buffer at pH 7.4. The stomach was dissected out and small fragments from the fundus were processed to obtain semithin sections stained with toluidine blue as well as ultrathin sections for E / M study. The fine structure of different forms of pre-parietal and parietal cells at different segments of zymogenic units was examianed. Also the mean surface area of both the clearly outlined mitochondria, and nucleoli were determined, the data were statistically analyzed for the test of significance as compared to the least differentiated pre-partial cells. The isthmus of the zymogenic units contained immature parietal cells identified as pre-parietal ones. Stage 1 pre-parietal cells had primitive small intracellular canaliculi while their cytoplasm housed numerous small mitochondria. Stage 2 pre-parietal cells exhibited small intracellular canaliculi with long microvilli. They contained tubulovesicles and numerous mitochondria. In stage 3, the cells showed deep intracellular canaliculi with excess microvilli, their cytoplasm housed numerous mitochondria and tubulovesicles. The mature parietal cells, in the neck and upper base, showed deep intracellular canaliculi swarmed with long microvilli. They contained rounded or oval mitochondria with closely packed cristae as well as extensive tubulovesicular system. There were a significant decline in the nucleolar size and an increase in the mitochondrial width as the cells proceeded from the immature to the fully differentiated forms. As the mature cells migrated downward to the base and upward to the pit of zymogenic units, their fine structure was altered. The signs of alteration were manifested by the appearance of clear spaces and lysosomal bodies in the cytoplasm. There were also disruption of tubulovesicular system and pleomorphism and distortion of mitochondria. As alteration progressed, there were more larger clear spaces in the cytoplasm, more disruption of the intracellular canaliculi and tubulovesicular system. The mitochondria exhibited abnormal shapes, disrupted cristae and clear matrices while lysosomal bodies and some autophagic vacuoles scattered in the cytoplasm. Parietal cells in advanced stages of alteration exhibited widely disteneded canaliculi, closely packed destroyed mitochondria, indistinct tubulovesicular system as well as lysosomal bodies. Necrosis of parietal cells was manifested by destroyed mitochondria while the remnants of the intracellular canaliculi appeared as wide spaces with destroyed microvilli. The completely degenerated parietal cells were seen protruding into the gastric lumen in their way for extrusion. These observations indicated that the parietal cells might have a cycle starting by differentiation, alteration and ending ultimately by death and extrusion