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Mast Cell Hyperplasia (mast + cell_hyperplasia)

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Medical Sciences	100%

Selected Abstracts

Mast cell hyperplasia in chronic rejection after liver transplantation

LIVER TRANSPLANTATION, Issue 1 2002
Cathal O'Keeffe
The pathogenesis of chronic hepatic allograft rejection is poorly understood. Recent studies suggested that hepatic mast cells may be involved in the pathogenesis of chronic cholestatic liver disease. Because chronic rejection after liver transplantation is predominantly a cholestatic process, the aim of this study is to determine whether hepatic mast cells are involved in its pathogenesis. Biopsy specimens from (1) normal livers (n = 5), (2) transplanted livers with end-stage chronic rejection (n = 8), and (3) transplanted livers with acute cellular rejection (mild, n = 7; moderate, n = 5; severe, n = 7) were studied. Biopsy specimens were stained immunohistochemically for mast cells with human antitryptase antibody. Mast cell density was significantly increased in the chronic-rejection group (4.9 ± 0.6/mm2) compared with controls (2.9 ± 0.5/mm2; P < .05). The percentage of portal tracts containing mast cells was significantly greater in chronic-rejection (89% ± 8%) than control biopsy specimens (69% ± 5%; P < .05), as was the average number of mast cells per portal tract (5.4 ± 0.9 v 1.9 ± 0.4 cells; P < .01). In chronic rejection, tissue mast cells frequently were seen surrounding damaged bile ducts in inflamed portal tracts. Neither mast cell density nor distribution was significantly different from controls in posttransplantation biopsy specimens with acute cellular rejection of mild, moderate, or severe degree. The finding of mast cells infiltrating portal tracts and surrounding damaged bile ducts in chronic rejection suggests that hepatic mast cells may be important effector cells in the pathogenesis of chronic rejection. [source]

Duodenal mastocytosis, eosinophilia and intraepithelial lymphocytosis as possible disease markers in the irritable bowel syndrome and functional dyspepsia

ALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 7 2009
M. M. WALKER
Summary Background, Irritable bowel syndrome (IBS) and functional dyspepsia (FD) are common functional disorders without defined pathology. Mast cells and eosinophils interact with T lymphocytes and may alter enteric nerve and smooth muscle function. Aim, To examine mast cell, eosinophil and intraepithelial lymphocyte populations in duodenal biopsies of subjects with IBS and FD. Methods, A random sample of an adult Swedish population (n = 1001; mean age 54 years; 51% female) underwent upper endoscopy and biopsy; 51 cases with FD and 41 cases with IBS were compared with 48 randomly selected controls. Eosinophils were identified by light microscopy; mast cells by immunocytochemistry (CD117). Intraepithelial lymphocytes were counted per 100 enterocytes. Cell counts were quantified by counting the number per high power field (HPF) in 5HPFs in the bulb (D1) and second part of duodenum (D2), summed over 5HPFs at each site. Results, Cases and controls showed similar demographics. Compared to controls, IELs in IBS-constipation were significantly increased (P = 0.005). Mast cells were significantly increased in IBS in D2 (P < 0.001), while eosinophils were significantly increased in FD in D1 and D2 (P < 0.001). Conclusion, Duodenal mast cell hyperplasia is linked to IBS and eosinophilia to FD, and duodenal biopsy may identify subsets of these disorders. [source]

Alterations of intestinal motor responses to various stimuli after Nippostrongylus brasiliensis infection in rats: role of mast cells

NEUROGASTROENTEROLOGY & MOTILITY, Issue 3 2000
J. Gay
Nippostrongylus brasiliensis infection induces jejunal mastocytosis associated with enteric nerve remodelling in rats. The aim of this study was to evaluate the intestinal motility responses to meals and to neurotransmitters involved in the control of gut motility (acetylcholine (carbachol), substance P and neurokinin A) in both control and N. brasiliensis -infected rats 30 days post-infection. All rats were equipped with NiCr electrodes in the jejunum to record myoelectrical activity. The duration of disruption of the jejunal migrating myoelectrical complexes (MMC) induced by the different stimuli was determined. Meal ingestion and substance P administration disrupted the MMC pattern for similar durations in the two groups. Carbachol and neurokinin A induced a significantly longer MMC disruption in post-infected rats than in controls (125 ± 8.3 vs. 70 ± 6 min for carbachol 100 ,g kg,1 and 51 ± 4 vs. 40 ± 2 for neurokinin A 50 ,g kg,1). The enhanced motor response in postinfected rats was reduced by previous mast cell stabilization with ketotifen or mast cell degranulation with compound BrX 537 A. In conclusion, the increased intestinal motor reactivity to carbachol and neurokinin A in post- N. brasiliensis -infected rats depends upon intestinal mast cell hyperplasia and degranulation. [source]

Protection in lambs vaccinated with Haemonchus contortus antigens is age related, and correlates with IgE rather than IgG1 antibody

PARASITE IMMUNOLOGY, Issue 1 2000
Kooyman
Protection by vaccination with excretory,secretory products (ES) from Haemonchus contortus, containing predominantly proteins of 15 and 24 kDa, against an experimental challenge infection depends on the age of the sheep. Vaccinated sheep 9, 6 or 3 months of age were protected for 83%, 77% and ,34%, respectively. There was a significant difference in ES-specific serum IgE response but not in IgG1 response, after the last vaccination between the different age groups. In the protected 9-month-old animals, there was an increase up to 18 times the prevaccination levels, while the increase in the unprotected 3-month-old animals was at most 1.4 times. The 6-month-old animals showed an intermediate increase of approximately six times the prevaccination level. There was no correlation within the 9-month-old sheep between ES-specific IgE levels and protection, measured as worm burden. However, when the different age groups were combined, there was a positive correlation (r = 0.38) between protection and ES-specific IgE levels 1 week after the vaccination. At the end of the experiment, peripheral blood eosinophils and mast cell counts in abomasal tissue were also significantly higher in the vaccinated and challenged 9-month-old sheep than in the vaccinated and challenged 3-month-old or than in the 9-month-old sheep with challenge, but without vaccination. Increased serum IgE levels, eosinophilia and mucosal mast cell hyperplasia are the hallmarks of a Th2 response and were all demonstrated in protected, older sheep, but not in unprotected, younger sheep. [source]