Activated Mast Cells Infiltrate in Close Proximity to Enteric Nerves in Diarrhea-predominant Irritable Bowel Syndrome

Mast cells (MC) may be one factor influencing the response of visceral afferent nerves to mechanical and chemical stimuli. The aim of this study was to evaluate the degree of infiltration and activity of colonic MC in irritable bowel syndrome (IBS). Biopsy specimens were obtained from the cecum and rectum of 14 diarrhea predominant IBS and 14 normal controls. Electron microscopy was used to determine the number of intact and degranulated colonic MC and to quantify these separately according to the distance between MC and enteric nerves. An increased number of MC in both cecum and rectum in the IBS group in comparison with the control group was demonstrated (p<0.05). Activated MC in close proximity to enteric nerves were significantly increased in both cecum and rectum of the IBS group compared to control group (p<0.005). In addition, activated MC were significantly increased in close proximity to the nerves compared to those in the remote area in both cecum and rectum of the IBS group (p<0.0001). MC were significantly increased and activated in both cecum and rectum of the IBS group compared to controls. MC may play a role in the gut sensory hypersensitivity of IBS.

Telangiectasia macularis eruptiva perstans: presentación de ocho casos y estudios ultraestructural / Telangiectasia macularis eruptiva perstans: report of 8 cases and an ultrastructural study

Las mastocitosis son desórdenes caracterizados por la infiltración de mastocitos en los tejidos. Dentro de éstas se encuentra la telangiectasia macularis eruptiva perstans (TMEP), una forma rara de presentación, más frecuente en adulto y de aparición ocasional en niños. El objetivo de este trabajo es realizar una recopilación de ocho pacientes con este cuadro vistos en el Servicio de Dermatología del Hospital Nacional "Prof. Alejandro Posadas", puntualizando sus caracteristicas clínicas e histopatológicas, y a travéz de un estudio con microscopía electrónica, aportar información a fin de aclarar su patogenia

Hiperplasia de mastócitos na oxalose óssea / Incresead mast cell number in oxalosis of bone

Objetivos. Avaliar através de técnicas de hitomorfometria a incidência de hiperplasia de mastócitos na medula óssea de pacientes portadores de oxalose e insuficiência renal crônica. Material e Métodos. Foram estudados 18 indivíduos em 3 grupos: 6 (4 homens e 2 mulheres com média de idade de 26.31+2.5 anos) portadores de oxalose óssea e insuficiência renal crônica (IRC); 6 (5 mulheres e 1 homem com idade média de 22.1+3.56 anos) portadores de IRC e 6 indivíduos saudáveis (5 homens e 1 mulher com idade média de 23+2.78 anos). A análise do tecido ósseo foi realizada em biópsias de crista ilíaca, incluídas em resina, sem descalcificaçao prévia e coradas pela técnica do Azul de Toluidina. A contagem dos mastócitos foi feita utilizando-se sistema analisador de imagens e os valores (média+DP) foram expressos sob a forma de células por mm2 de tecido. Resultados. O número de mastócitos foi significativamente maior nos portadores de oxalose óssea, 32.67+9.59, ao comparar com os pacientes portadores de IRC sem oxalose (20.84+5.04, p<0.05) e nos indivíduos do grupo controle (3.26+1.03, p<0.001). Conclusoes. A oxalose óssea está associada com um aumento substancial do número de mastócitos na medula óssea. Esta alteraçao nao está relacionada com a IRC per se e nao parece representar uma resposta inespecífica à fibrose medular. O acúmulo anormal de mastócitos deve, de alguma forma, contribuir para o desenvolvimento da fibrose de medula óssea que acompanha esta condiçao.

Ultrastructural studies of mast cells, fibroblasts and endothelial cells, in clinically involved skin of patients with scleroderma

A hypothetical role of mast cells, endothelial cells and fibroblasts, in the pathophysiology of scleroderma has been proposed. The present study aimed at the illustration of the ultrastructural changes of these cells, in particular, in the skin of patients with scleroderma. In the following work, electron microscopic examination demonstrated a spectrum of degranulated mast cells as well as different grades of cell-activation evidenced by presence of hypodense granules with increased cytoplasmic organelles such as rough-surface endoplasmic reticulum [RER], polysome and mitochondria. The fibroblasts showed numerous dilated RER, intra and extracytoplasmic filaments. Some fibroblast - like cells were seen ingesting some mast cell granules. Evidences of endothelial injury were detected in the form of thickening and stratification of basal lamina and swollen endothelial cells

Efecto in vitro del cloruro de niquel sobre los mastocitos y macrofagos peritoneales / In vitro effect of nickee chloride on mastercells and peritoneal macrophages

Se investigó el efecto de diferentes concentraciones de cloruro de níquel sobre la degranulación de los mastocitos aislados de ratas y la liberación de histamina inducidos por el compuesto 48/80, así como su efecto sobre las células fagocíticas peritoneales utilizando técnicas de microscopía óptica y electrónica. El níquel no indujo la liberación de histamina de los mastocitos, en cambio sí provocó una marcada disminución de la histamina liberada por 48/80, paralelamente a un aumento en la fagocitosis de los gránulos de histamina por parte de macrófagos y eosinófilos. También indujo liberación de la enzima B galactosidasa de macrógfagos peritoneales de ratón in vitro. Se concluye que las reacciones inflamatorias por exposición al níquel no son mediadas por liberación de histamina inducida por el ión y pudieran estar relacionadas a la liberación de enzimas de los lisosomas

An Electron Microscopic Study on Mast Cell Degranulation and Regeneration in Rats

The morphdogical changes in mast cells, induced by horseradish peroxidase (HRP) and distilled water were studied, using light and electron microscopy. The mesenteries of rats sacrificed at 30 minutes; at 1, 2, 4 and 18 hours; and at 1, 2, 3 and 6 weeks after an intraperitoneal injection of 250 microgram or 500 microgram of HRP or 10 ml of distilled water were used for observation of degranulation rates and morphological changes in cell organelles during specified time intervals. The results were as follows: 1) A distinct increase in the mast cell degranulation was observed in the mesenteries after injection of HRP. In particular, all mast cells were disrupted or degranulated significantly 18 hours after injection of distilled water. 2) The degranulating mast cells of the group injected with HRP showed a progressive decrease in electron density of the granules, formation of perigranular cavities, and extrusion of the granules after partial loss of the plasma membrane. 3) At 2 weeks after injection of HRP, some indicators of the early stage of regeneration, that is, peripherally placed nucleus, the expanded Golgi area containing numerous vesicles, and progranules in these vesicles, were observed. 4) After 6 weeks, the morphological characteristics of most mast cells in the group injected with HRP were nearly the same as those of the control group. 5) In degranulating mast cells of the group injected with distilled water, partial rupture of the plasma and cytoplasm with wide dispersion of the granules.

An Ultrastructural Study of Urticaria Pigmentosa

To investigate ultrastructural characteristics of mast cells in urticaria pigmentosa in comparison to mast cells in other conditions and to search for the possible differences of ultrastuctural features amog different types of urticaria pigmentosa as well as those from normal mast cells, 4 cases of urticaria pigmentosa and 1 case of mastocytosis associated with capillary hemangioma were studied by both light and electron microscopic examinations. The cases of urticaria pigmentosa consisted of one case of blister type from a 3 month old ma1e infant, 2 cases of maculo-papular type both from 10 month old male infants, and a case of nodular type from a 14 month old boy. Ultrastructural features of mast cells in urticaria pigmentosa, in general; a) appeared relatively immature; b) mast cells in nodular type of urticaria pigmentosa were mostly round shaped while other types showed spindle or oblong shapes; c) mast cells in the maculo-papular type and those in hemangioma were similar and resembled normal mast cells; and d) marked degranulation of mast cells in the form of expulsion of granules, perigranular vacuole formation and intracellular disolution of granules for the blister type of urticaria pigmentosa.

Electron Microscopic Observations on the Morphological Changes of Rat Mesentric Mast Cells Induced by Morphine HCl

The effects of morphine HCI on the rat mesenteric mast cells were studied with the electron microscopy. The materials were prepared for electron microscopy by osmium tetroxide fixation and embedding in Epon. The rat mesenteric mast cells showed no distinct morphological changes due to morphine HCl, but the mast cell granlues were changed in various ways. For instance, they formed dusters, showed granular lysis, and an appearance of electron transparency. Frequently, some granules appeared in the extracellular space and the boundary of the granules was not evident. From the results mentioned above, it was suggested that rat mesenteric mast cell granules were affected by morphine HCl in the shape, the granular matrix, and the granular boundaries.