Stress-triggered changes in the adrenal medullary cells structure and function in the rat

Objective: Previous authors provided electrophysiological evidence for selective activation of epinephrine or norepinephrine-secreting adrenal chromaffin cells. However, the corresponding histological changes in the adrenal chromaffin cells were not described. To provide histological and biochemical evidence that different sympathetic preganglionic neurons regulate epinephrine and norepinephrine secretion

Methods: Male Wistar albino rats weighing 220-250g were subjected to stress inducing experiments including insulin-induced hypoglycemia, acute exposure to cold and acute hemorrhagic hypotension. The fine structure of adrenomedullary cells was examined; their catecholamine contents and volume fractions were measured

Results: Insulin injection was followed by gradual and progressive depletion of epinephrine storing granules with no effect on norepinephrine granules, acute exposure to cold produced a response consistent with activation of norepinephrine secreting chromaffin cells, while acute hemorrhagic hypotension produced activation of both epinephrine and norepinephrine cells, all these morphological changes were accompanied by corresponding changes in the catecholamine content of the adrenal gland as well as in the volume fractions of epinephrine and norepinephrine cells

Conclusions: In the presence of similar nerve endings on the epinephrine and norepinephrine chromaffin cells, the above results suggest the presence of different adrenal sympathetic preganglionic neurons that regulate epinephrine and norepinephrine secretion

Enterobius vermicularis infection in three refugee camps in Jordan

Pinworm infection remains prevalent in many parts of the world. It is suspected in children who exhibit perineal pruritus and nocturnal restlessness. The diagnosis is generally made by the cellophane tape test, and the treatment consists of a 100-mg single dose of mebendazole. To determine the prevalence of pinworm infection in children with perianal itching and to minimize the reinfection rate by a modified method of treatment. 812 children, 5-15 years old children were the subjects of this study. Cellophane tape test was used in 707 children and a swab taken through proctoscope in 105 children of the older age group. Mebendazole in a single dose of 100 gm was used in all parasite positive children. Half of the treated children received rectal enemas made of sodium chloride in tap water and received health education to prevent reinfection and spread of the parasite. 44.8 [55.2%] of the children examined were found to be infected with enterobius vermicularis with the higher prevalence in Jarash camp. The proctoscopic method achieved more significant results than the cellophane tape test [68.6% versus 42.6%] [X2: 6.46, P=0.01]. Similarly, mebendazole treatment together with rectal enemas and health education achieved a higher cure rate than using mebendazole alone [81.6% versus 23.3%] [X2: 138.6, P=0.0001]. Pinworm infection should be suspected in children who exhibit anal itching and nocturnal restlessness. Following diagnosis, mebendazole should be given and rectal enemas continued for 8 weeks. Health education to the parents and children forms an integral part of treatment

Chromaffin cells in the adrenal medulla of the mouse: a morphological study of their innervation

To study the synaptic nerve endings on the adrenaline [A], noradrenaline [NA] and small granular Chromaffin [SGC] cells of the mouse before and after puberty and the possible functional relationship between these cells. Male albino mice bred at the animal house-Jordan University, which aged 5, 10 and 12 days and 5 weeks were used. After sacrifice, the adrenal glands were removed from the animals and processed for examination with a Philips 300 electron microscope. The percentage of SGC cells and the number of synaptic endings on A and NA cells were calculated. All the nerve endings observed are typical in appearance with the cholinergic-type synaptic endings. No evidence of an adrenergic innervation of Chromaffin tissue of the adrenal medulla has been obtained during the present work, though the elongated processes of small granular Chromaffin cell could readily be misinterpreted as adrenergic nerve fibres. The processes of these cells come close to other Chromaffin cells, both A, NA cell and form synapses. Frequent exocytotic figures related to these cells were observed. The present findings suggest that the SGS cells form an intrinsic system that regulates the activity of other chromaffin cells, particularly in the early postnatal period when the extrinsic innervation of the chromaffin cells is not yet fully developed

Correlation between the morphology of the spleen and the vascular pattern at its hilum [research note]

The vascular anatomy of the spleen with its segmental architecture offers the opportunity for partial splenectomy. Since the splenic segments cannot be distinguished from the surface, the arteries and veins supplying and draining the part of the spleen to be resected should be identified and ligated as the first step. The aim of this study was to investigate the hilar vascular pattern of the spleen and to correlate it with the shape of the spleen, the presence or absence of notches at the anterior border, and the length of the hilus. Sixty spleens were studied by careful dissection of the hilar vessels. A bifurcation of the splenic artery was not noted in 93.3% and a trifurcation in 6.7%. The Y-type of branching of the hilar vessels with easier access for surgical procedures was noted in 83.3% and a T-type in 16.7%

Effects of student examination stress on the blood and urine osmolality: a possible syndrome of inappropriate ADH [SIADH]

Serum Na[+], K[+], glucose, urea, osmolality, urine Na and osmolality were measured in university students subjected to examination stress. A total of 16 healthy subjects of the age range 19-23 were studied. The results showed significant decrease in serum osmolality attributed mainly to hyponatremia together with significant increase in urine Na[+] and osmolality. These results suggest an inappropriate secretion of antidiuretic hormone [ADH] as a result of emotional stress acting on the visceral brain [limbic and reticular activating systems]

comparison between the effects of hypophysectomy and cyproterone acetate on the adrenal medulla chromaffin cells of the mouse

The effects of reduction in the glucocorticoid secretion on the adrenomedullary chromaffin cells of the mouse were studied through hypophysectomy and cyproterone acetate [CA] administration. The latter drug is reported to have a pronounced ACTH suppressive effect and to interfere with steroid biosynthesis. There was no evidence of a change in the proportion of epinephrine - storing [E] and nonepinephrine storing [NE] cells in the adrenal medulla of hypophysectomized mice or CA-treated animals. In hypophysectomized animals, the norepinephrine [NE] showed a significant Increase in content and proportion. This was attributed - to a significant decrease in the epinephrine [E] content of these animals. The adrenal glands of CA-treated animals did not show any significant change in NE content, although a significant increase in the NE proportion of the total catecholamine was observed. This was again attributed to the significant decrease in the E content of CA animals. The ultrastructural changes showed the presence of both E and NE granules in the same cell. In addition, many cells showed marked reduction in their secretory granules and appear similar to sympathetic neurons. The reversibility of these changes following cessation of CA - treatment suggests that they represented temporary metabolic changes rather than a process of dedifferentiation of these cells

Effects of diclofenac sodium on the gastric mucosa of the rat: a histological, morphometric and hormonal study

The present histological and hormonal investigation showed that the gastric mucosa of the rat has responded to the oral and parenteral diclofenac treatment by two protective mechanisms. The first of these was a temporary increased production of surface mucus and the second was a squamous metaplasia of the surface epithelium. Both changes were more marked in the orally treated animals. The squamous metaplasia was associated with a significant increase in the number of the parietal cells per unit area. It is suggested that these changes were produced by a direct effect of the drug on the stem cells from which the parietal and epithelial cells were derived or through the effects of gastrin hormone. The antral and serum levels of this hormone were significantly elevated after oral diclofenac treatment

Differentiation of chromaffin cells in explants of rat adrenal medulla, a light and electron microscopic study

To evaluate the factors which cause the differences between an adrenergic neuron and an adrenal chromaffin cell, both of which are derivatives of the neural crest, the adrenal medulla of the rat was transplanted under the kidney capsule. In addition to increase in the percentages of noradrenaline and nerve cells, the transplant showed the presence of new types of cells which have morphological characteristics intermediate between chromaffin cells and sympathetic neurons. The changes in the adrenal chromaffin cells of the transplant were more marked after suppression of ACTH and glucocorticoid production by giving medroxyprogesterone acetate. The significance of these findings are discussed especially in relation to transplants of adrenal chromaffin cells in the brain

anatomical features and functional significance of lumbar transitional vertebra

Three hundred and fourty sacra of 2 population groups were examined for the presence of lumbosacral transitional vertebrae. Of these 32 [9.4%] showed evidence of unilateral sacralization and 14 [4.1%] showed bilateral sacralization. Lumbarization was not observed in any of the examined sacra. Although controversy exists as to the possible effects of sacralizatvon, the findings of the present study has shown that unilateral saralization may be associated with structural changes of sacrum which are of functional significance

Some observations on conjoined twins

The anatomy and embryology of conjoined twinning was studied using five specimens. The partners in all the specimens were joined at thorax and abdomen [thoracoomphalopagus]. Internally, the heart, liver, diaphragm and gut, were the major conjoined structures. There was no correlation between the degree of external fusion and the conjoining of internal organs. The anatomical features of the conjoined organs suggest that mechanical factors may have contributed to the conjoining process or to the final position of the conjoined organs as well as the surrounding viscera

Effects of vagotomy on the gastric mucosa of the rat: a morphometric and histochemical study

The present histological investigation showed that bilateral truncal vagotomy produced significant increase in the total number of mucous neck cells of the fundic glands as well as in the total mucous cell population of the mucous and mucoparietal glands present in the cephalic and caudal mucous regions of the fundic mucosa. These changes were associated with a significant reduction in the total number of peptic cells and with a decrease in the ratio between the height of the pit and the glandular part. In the absence of any change in the surface area, height and volume of the fundic mucosa, the above changes suggest the Incidence of a new line of differentiation of the isthmal cell which is the mother cell for both the pit and glandular part of these glands. The possible explanation and significance of these findings are discussed

Effects of partial devascularization of the adrenal cortex, with or without hypophysectomy, on the adrenal chromaffin cells

The effects of marked reduction in the concentration of the corticosteroids that reach the adrenal medulla, on the morphology of adrenal chromaffin cells, were studied in the rat. Necrosis of the adrenal cortex through partial devascularization, with or without hypophysectomy, were employed. It was found that the change in the metabolic activity of the adrenaline-storing cells into noradrenaline-storing cells could only be achieved after necrosis of the greater part of the adrenal cortex together with hypophysectomy

neurogenic type of arthrogryposis multiplex congenita: a report of a neonatal fatal form

A female infant affected with the neurogenic type of arthrogryposis multiplex congenita is reported. Gross autopsy findings and histopathological observations are presented with particular reference to the skeletal muscles and the central nervous system. The most striking feature was fatty replacement of most muscles of the limbs. Microscopy of the spinal cord revealed degenerative changes of the anterior horn cells which suggests that the muscular changes were the outcome of neurogenic atrophy. Arthrogryposis multiplex congenita [AMC] is a syndrome of persistent joint contractures present at birth[1-3]. It was first described in 1841 by Otto who called it "congenital myodystrophy[4]". The term "arthrogryposis multiplex congenital", generally accepted at present, was first used by Stern[5] in 1923. Theories concerning the nature of the illness have been varied and contradictory. Analysis of pathological findings indicates that there are two fundamental mechanisms responsible for AMC, namely a neurogenic or a myogenic defect[6,7]