Biomedical subjects

D G Binion

Publications and source records attributed to D G Binion.

22 records · Page 2Linked to original sources

PubMed1998

Intrinsic hyperreactivity of mucosal T cells to interleukin-2 in pediatric Crohn's disease.

OBJECTIVES: To cells play a crucial role in many chronic inflammatory diseases. Mucosal T cells are particularly important in the pathogenesis of Crohn's disease (CD). We investigated the response of T cells in CD and other intestinal inflammatory conditions to interleukin-2 (IL-2), a cytokine essential for T-cell activation, growth, and function. STUDY DESIGN: T-cell reactivity was assessed by measuring growth induced by IL-2 in mucosal endoscopic biopsy specimens obtained from children with CD, ulcerative colitis, indeterminate colitis, and chronic nonspecific colitis and from children without gastrointestinal inflammation. RESULTS: CD mucosal T cells grew remarkably and significantly more than T cells from normal, ulcerative colitis, and chronic nonspecific colitis mucosa. T cells from indeterminate colitis mucosa grew similarly to those of CD mucosa. The enhanced growth response in CD was independent of disease location, presence or absence of intestinal inflammation, treatment, disease duration, or clinical activity. CONCLUSION: Mucosal T cells from children with CD exhibit an intrinsic hyperreactivity to IL-2. This may represent a primary pathogenic abnormality in this condition.

Adolescent↗

PubMed1998

iNOS expression in human intestinal microvascular endothelial cells inhibits leukocyte adhesion.

Increased nitric oxide (NO) production by inducible nitric oxide synthase (iNOS) has been associated with intestinal inflammation, including human inflammatory bowel disease. However, NO can downregulate endothelial activation and leukocyte adhesion, critical steps in the inflammatory response. Using primary cultures of human intestinal microvascular endothelial cells (HIMEC), we determined the role of NO in the regulation of HIMEC activation and interaction with leukocytes. Both nonselective (NG-monomethyl-L-arginine) and specific (N-iminoethyl-L-lysine) competitive inhibitors of iNOS significantly increased binding of leukocytes by HIMEC activated with cytokines and lipopolysaccharide. Increased adhesion was reversible with the NOS substrate L-arginine and was not observed in human umbilical vein endothelial cells (HUVEC). Activation of HIMEC significantly upregulated HIMEC iNOS expression and NO production. NOS inhibitors did not augment cell adhesion molecule levels in activated HIMEC but did result in sustained increases in intracellular reactive oxygen species. In addition, antioxidant compounds reversed the effect of NOS inhibitors on HIMEC-leukocyte interaction. Taken together, these data suggest that after HIMEC activation, iNOS-derived NO is an endogenous antioxidant, downregulating leukocyte binding and potentially downregulating intestinal inflammation.

Arginine↗

PubMed1997

Enhanced leukocyte binding by intestinal microvascular endothelial cells in inflammatory bowel disease.

BACKGROUND & AIMS: Microvascular endothelial cells mediate leukocyte homing, angiogenesis, and inflammation and healing and show tissue-specific adhesion molecules and functions. The activation of human intestinal mucosal microvascular endothelial cells (HIMECs) was studied in vitro to uncover possible abnormalities associated with inflammatory bowel disease. METHODS: HIMECs were isolated from normal and inflammatory bowel disease mucosa and assessed for phenotypic and morphological features, proliferative response, leukocyte binding capacity, and adhesion molecule expression. RESULTS: Basal proliferation by HIMECs was less than that of human umbilical vein endothelial cells (HUVECs) but increased proportionally more in response to vascular endothelial growth factor. Proinflammatory stimuli induced an activated, spindle-shaped morphology in HIMEC monolayers. Compared with HUVECs, unstimulated HIMECs showed less adhesiveness for U937 and MOLT4 cells and neutrophils, but cytokines and lipopolysaccharide substantially increased the binding capacity of HIMECs. HIMECs derived from inflammatory bowel disease mucosa showed a markedly greater leukocyte-binding capacity than normal mucosal HIMECs. Patterns of intercellular adhesion molecule 1, vascular cell adhesion molecule 1 and E-selectin messenger RNA expression were distinct in HIMECs, HUVECs, and mucosal mesenchymal cells. CONCLUSIONS: HIMECs represent differentiated endothelial cells with unique functional properties. Their dramatically enhanced capacity to bind leukocytes in inflammatory bowel disease suggests that HIMECs play an important role in initiating or maintaining inflammation.

Endothelium↗

PubMed1994

The role of endoscopy in inflammatory bowel disease.

Endoscopy has assumed a preeminent role in the diagnostic approach to IBD. It is more sensitive than radiography in detecting early, subtle changes of IBD, both through endoscopic appearance and histologic sampling of mucosa. Endoscopy also appears to be a safe technique in patients presenting with severe forms of colitis and can play an important role in defining the etiologic basis of disease in this subgroup of patients. In addition to its diagnostic role, endoscopy has proven useful in surveying disease activity, through the development of endoscopic disease activity indices. Endoscopy has also found a prominent role in the diagnostic and therapeutic approach to IBD complications. Endoscopic surveillance of chronic UC patients at risk for colon carcinoma has helped to define a therapeutic approach to this serious complication of UC. Endoscopic therapy has been applied to treat stricture formation associated with long-standing CD. Biliary endoscopy also represents the strategy of choice for diagnosing primary sclerosing cholangitis, an extraintestinal complication occurring in 5% of UC patients. Finally, endoscopy may help facilitate the discovery of disease pathogenesis in IBD, through the use of endoscopically recovered biopsy specimens in the research laboratory. Endoscopy allows for ready access to human tissue that has been the cornerstone of disease-related research over the past two decades.

Diagnosis, Differential↗