Developmental changes of internal anal sphincter in guinea pigs: a histological and immunohistochemical study

The internal anal sphincter [IAS] plays an important role in the maintenance of anorectal continence and in the pathophysiology of constipation and incontinence. Failure of a full-term newborn to pass meconium within the first 24 h should raise a suspicion of intestinal obstruction. However, the causes of functional intestinal obstruction in infants are still unclear; however, one cause might be immaturity of the IAS. This study aimed at illustrating the developmental changes in IAS in guinea pigs of different ages. Forty-one guinea pigs were selected and divided into four groups. They were sacrificed and the rectoanal canal specimens were dissected at the appropriate time from each group as follows: group I - from embryos in the third trimester; group II - from animals on their first postnatal day; group III - from animals aged 4 weeks; and group IV - from animals aged 16 weeks. The rectoanal canal specimens was prepared for histological and immunohistochemical studies. Morphometric analysis was also performed. Thickness of the IAS increased with advancing age, whereas that of the connective tissue component decreased. Moreover, alpha-smooth muscle actin filaments increased with age. There was also age-related development of the enteric nervous system, especially the myenteric plexus in the rectoanal junction region. Results of the current study revealed pronounced developmental changes in the histological structure of guinea pig IAS. Therefore, development of the IAS might have a possible role in the functional intestinal obstruction seen in preterm and full-term infants

Stimulatory effect of helium-neon laser irradiation on human umbilical vein endothelial cells

Low-level laser irradiation [LLLI] has been shown to modulate the proliferation of endothelial cells. Helium-neon [He-Ne] laser is the best type of laser for biostimulation. The aim of the present study was to investigate the direct stimulatory effect of LLLI on the proliferative potential of human umbilical vein endothelial cell line in vitro. This study included five groups: group I [zero time after seeding He-Ne laser irradiation], group II [24 h after seeding He-Ne laser irradiation], group III [48 h after seeding He-Ne laser irradiation], group IV [96 h after seeding He-Ne laser irradiation], and group V [cumulative He-Ne laser irradiation every 48 h for a period of 6 days]. Each group was subdivided into three subgroups: subgroup a [control], subgroup b [1.77 J/cm[2]He-Ne laser irradiation], and subgroup c [3.54 J/cm[2] He-Ne laser irradiation]. A continuous wave He-Ne laser, emitting a wavelength of 632.8 nm with a power output of 5 mW was used for irradiating the cells. A growth curve was constructed for each group to determine the growth parameters. The most efficient cellular response to LLLI was in subgroup Ic depending on the population doublings achieved, followed by subgroup Ib. Therefore, the early the use of He-Ne laser irradiation for the cultured cells, the more the cellular stimulation and proliferation. Meanwhile, their delayed use resulted in less cellular stimulation and proliferation. Moreover, the results showed that 1.77 and 3.54 J/cm[2] of He-Ne laser irradiation were always stimulatory for endothelial cells either significantly or insignificantly. The present study showed that 1.77 and 3.54 J/cm[2] of He-Ne laser irradiation stimulated human umbilical vein endothelial cell line proliferation

Histological, immunohistochemical, and morphometric study on the postnatal development of Peyer's patches in albino rat

Peyer's patches [PPs] are essential elements of the gut-associated lymphatic tissue that are involved in defense against pathogens that may be colonizing the gut and are also involved in oral food tolerance otherwise food allergy occurs. This research aimed to study the postnatal development of PPs in male albino rats. Fifty male albino rats were divided into five groups of 10 animals each. Group 1 [1 day old], group 2 [1 week old], group 3 [2 weeks old], group 4 [4 weeks old], and group 5 [8 weeks old]. The terminal part of the ileum was dissected out and processed for light and electron microscopic examinations. Paraffin sections were stained with hematoxylin and eosin, periodic acid-Schiff and immunohistochemical staining was carried out for detection of CD3 and CD20 [markers of T and B lymphocytes, respectively]. Quantitative morphometric study was conducted, and the results were statistically analyzed. Early during postnatal period, PPs appeared as small epithelial elevations overlying small aggregates of lymphocytes. The size of PPs and lymphocytic cell density increased gradually to reach maximum by adult age [group 5]. Most of the lymphocytes were of the T type early postnatally followed by increase in B lymphocytes during the following age groups. Germinal centers started to appear in group 4 and in the adult age group. The epithelium covering the surface of PPs showed reduced number of goblet cells, and M cells started to appear from the age of 2 weeks onward. Epithelium covering the PPs showed structural changes matching with functional specialization such as gradual reduction of goblet cells and appearance of M cells. In addition, an association was found between the times of onset of M cells and B-Iymphocytic follicles in PPs

Histological study on the effect of pyrrolidine dithiocarbamate on hepatic and small intestinal injury induced by ischemia reperfusion in rats

Restoration of the blood flow and reintroduction of oxygen after deprivation accelerate tissue injury. The insult of intestinal ischemia reperfusion [PR] is not necessarily limited to the intestine itself, but involves the severe destruction of the other tissues because of the reperfused oxygenated blood. Many reports indicated that I/R is an important inciting event in the pathogenesis of multiple organ system failure, which is the leading cause of death in critically ill patients. So, the aim of this study was to evaluate the possible protective role of pyrrolidine dithiocarbamate [PDTC] on liver and small intestinal injury following mesenteric ischemia reperfusion. The study was performed on forty adult male albino rats weighting 200-250 gm that were divided into three groups. Group I: Control animals which divided into untreated and sham operated [10 animals each]. Group II: Intestinal ischemia reperfusion animals, which were underwent one hour ischemia and two hours reperfusion. Group Ill: Animals received 200 mg/kg PDTC intraperitoneally one hour before intestinal ischemia reperfusion procedure. Parts were taken from the liver and jejunum were processed for histological examination and other jejunal parts for scanning electron microscopic examinations [SEM]. Immunohistochemical expression of NF-ka B factor in the liver was investigated. A variety of changes were observed in the jejunal ranging from epithelial separation and loss of the brush border to cellular lysis, destruction of villi, cellular infiltrations, hemorrhages and basal glandular ulcerations. The liver showed areas of edema fluid, hemorrhages, mononuclear cellular infiltration and increased expression of INF-ka B factor. Treatment with PDTC resulted in improvement in most of the histological changes induced by intestinal ischemia-reperfusion in the jejunum and liver. Therefore, PDTC can be considered as an effective protecting agent during intestinal ischemia reperfusion and can be used clinically in such instances

possible protective effect of curcumin on naphthalene induced cataract in rats [histological and scanning electron microscopic Study]

Cataract formation is one of the irreversible processes for which modem medical science has no definite cure except surgery. Drugs that may have prophylactic or curative effects for cataract are lacking. Naphthalene has wide industrial and commercial applications and it is well known that ingestion of naphthalene causes cataract in human and experimental animals. Curcumin, a widely used spice, has been proved to have an antioxidant activity in vitro and in vivo. The purpose of this study was to test the possible efficacy of curcumin in preventing cataract formation in a rat model. So, forty adult male albino rats weighting 100-120 gm were used in this study. They were divided into the experimental groups. Group I: Control animals. Group II: Animals received a dose of 0.7 g/kg of naphthalene solution orally daily for 90 days. Group III: Animals concomitantly administered curcumin with naphthalene in a dose of 75 mg/kg orally daily for the same duration. Slit lamp examination and retroillumination photography were done to all animals at the end of the experiment, then the rats were sacrificed and the lenses were removed and processed for histological and scanning electron microscopic [SEM] examination. Animals received naphthalene showed, by slit lamp photography, equatorial vacuoles and anterior subcapsular white opacities. Histologically, lens capsule was thin with hyperplasia of the lens epithelium. PAS stained deposits were also seen under the capsule with increased spacing between the lens fibers. Furthermore, the hexagonal cross sectional structure of lens fibers was lost in some areas. SEM showed loss of ball and socket interlocking between the lens fibers. Concomitant administration of curcumin with naphthalene resulted in amelioration of most of the histological changes induced by naphthalene. Therefore, curcumin may have a beneficial effect in protection against cataractogenesis