Increased inherent intestinal granzyme B expression may be associated with SIV pathogenesis in Asian non-human primates.

BACKGROUND: Unlike Asian non-human primates, chronically SIV-infected African non-human primates (NHP) display a non-pathogenic disease course. The different outcomes may be related to the development of an SIV-mediated breach of the intestinal mucosa in the Asian species that is absent in the African animals. METHODS: To examine possible mechanisms that could lead to the gut breach, we determined whether the colonic lamina propria (LP) of SIV-naïve Asian monkeys contained more granzyme B (GrB) producing CD4 T cells than did that of the African species. GrB is a serine protease that may disrupt mucosal integrity by damaging tight junction proteins. RESULTS: We found that the colonic LP of Asian NHP contain more CD4(+) /GrB(+) cells than African NHP. We also observed reduced CD4 expression on LP T cells in African green monkeys. CONCLUSION: Both phenotypic differences could protect against SIV-mediated damage to the intestinal mucosa and could lead to future therapies in HIV(+) humans.

Cryopreserved human amniotic membrane and a bioinspired underwater adhesive to seal and promote healing of iatrogenic fetal membrane defect sites.

INTRODUCTION: We investigated the ability of cryopreserved human amniotic membrane (hAM) scaffold sealed with an underwater adhesive, bio-inspired by marine sandcastle worms to promote healing of iatrogenic fetal membrane defects in a pregnant swine model. METHODS: Twelve Yucatan miniature pigs underwent laparotomy under general anesthesia at 70 days gestation (term = 114 days). The gestational sacs were assigned to uninstrumented (n = 24) and instrumented with 12 Fr trocar, which was further randomized into four different arms-no hAM patch, (n = 22), hAM patch secured with suture (n = 16), hAM patch with no suture (n = 14), and hAM patch secured with adhesive (n = 9). The animals were euthanized 20 days after the procedure. Gross and histological examination of the entry site was performed for fetal membrane healing. RESULTS: There were no differences in fetal survival, amniotic fluid levels, or dye-leakage from the amniotic cavity between the groups. The fetal membranes spontaneously healed in instrumented sacs without hAM patches. In sacs with hAM patches secured with sutures, the patch was incorporated into the swine fetal membranes. In sacs with hAM patches without sutures, 100% of the patches were displaced from the defect site, whereas in sacs with hAM patches secured with adhesive 55% of the patches remained in place and showed complete healing (p = 0.04). DISCUSSION: In contrast to humans, swine fetal membranes heal spontaneously after an iatrogenic injury and thus not an adequate model. hAM patches became incorporated into the defect site by cellular ingrowth from the fetal membranes. The bioinspired adhesive adhered the hAM patches within the defect site.

Alterations in myeloid dendritic cell innate immune responses in the Galphai2-deficient mouse model of colitis.

BACKGROUND: The G protein alpha subunit type-2 (Galpha(i)2)-deficient mouse develops inflammatory bowel disease (IBD) with increased severity in mice on a 129SvEv (129) background compared to the C57BL/6 (B6) background. Since dendritic cells (DCs) are key cells of innate immunity, we determined whether Galpha(i)2(-/-) DCs have functional defects, influenced by strain background, that predispose to IBD. METHODS: By breeding these strains to homozygosity for the first time, it became possible to study innate immunity in this animal model with more precision than ever before. Immature DCs were generated using bone marrow monoblasts cultured in the presence of GM-CSF (BMDCs), DC subsets sorted and responses to TLR9 activation were assayed. RESULTS: In contrast to Galpha(i)2(-/-) B6, Galpha(i)2(-/-) 129 mice display accelerated onset and increased severity of colitis, abnormal mucosal DC distribution, accompanied by preponderance for Th1 and Th17-associated gut cytokine expression. TLR9 activation of BMDCs induces sustained p38 MAPK activation and greater Th1- and Th17-type cytokine secretion in both strains of Galpha(i)2-deficient compared to wildtype BMDCs. However, only B6 Galpha(i)2(-/-) BMDCs concomitantly produces IL-10 while Galpha(i)2(-/-) 129 BMDCs do not. CONCLUSIONS: Loss of Galpha(i)2 promotes a Th1/Th17 phenotype and relative IL-10 insufficiency in Galpha(i)2(-/-) 129 BMDCs may account for the striking difference in disease.

Diagnostic yield of oesophagogastroduodenoscopy in children with abdominal pain.

BACKGROUND: Abdominal pain is the most common indication for oesophagogastroduodenoscopy (OGD) in children. However, existing studies examining the diagnostic outcomes of OGD in children with abdominal pain are limited. AIM: To examine the diagnostic yield of OGD with biopsy in the evaluation of abdominal pain and to describe the endoscopic and histological findings in patients undergoing OGD for abdominal pain of unclear aetiology. METHODS: We performed a retrospective cross-sectional cohort study in children under 18 years of age who had OGD for the primary indication of abdominal pain, at Texas Children's Hospital and Children's Hospital of The King's Daughters from 1 January 2002 to 30 June 2005. RESULTS: Overall, OGD was diagnostic in 454 (38.1%) of the 1191 procedures, including reflux oesophagitis (23%, n = 271), Helicobacter pylori infections (5%, n = 55), peptic ulcers (3%, n = 32), eosinophilic oesophagitis (2%, n = 25), celiac disease (1%, n = 9) and Crohn's disease (0.5%, n = 7). Male gender, older age, elevated C-reactive protein and vomiting were associated with increased diagnostic yield. CONCLUSIONS: Our findings suggest that OGD is valuable for the evaluation of chronic abdominal pain in children, with a diagnostic yield of 38%. The majority of alarm symptoms and routine laboratory tests are not significantly associated with diagnostic yield.