BACKGROUND The bacterial chemotactic peptide N-formyl-methionine-leucine-phenylalanine (FMLP) is produced by enteric flora and is one of the factors implicated in contributing to inflammatory bowel disease. Expression of receptors for FMLP on human phagocytes (polymorphs and monocytes) is well established, but there is conflicting evidence regarding the potential expression of FMLP receptors on...

We previously described an animal model of Helicobacter pylori-induced follicular gastritis in neonatally thymectomized (nTx) mice. However, it is still not clear whether antigen-presenting dendritic cells (DCs) in the stomach have a role in the development of secondary follicles in H. pylori-infected nTx mice. We investigated the distribution of DC subsets using this model and examined their r...

The concept of lymphoid differentiation in the human gastrointestinal tract is controversial but is the focus of this study, which examined adult human small intestinal tissue for the presence of CD34(+)CD45(+) hemopoietic stem cells (HSCs) and lymphoid progenitors. Flow cytometry demonstrated that over 5% of leukocytes (CD45(+) cells) isolated from human gut were HSCs coexpressing CD34, a sign...

Lymphocyte subpopulations in the intestinal mucosa of patients with ulcerative colitis or Crohn's disease have been studied using a double marker immunofluorescence technique. Analysis of tissue sections revealed that the majority of intraepithelial lymphocytes (IEL) were T cells (Hle-1+ HuTLA+ UCHT1+). Of these, over 80% were of suppressor-cytotoxic phenotype (OKT8+:83 +/- 10.2%) with a small ...

Recently, many details of the interplay between tumor cells and tumor-associated stromal elements leading to the progression of malignant disease were elucidated. In contrast, little is known about the role of uninvolved stromal tissue in the remote surrounding of the malignant tumor. Therefore, we performed a computer-aided morphometric study of rectal mucosa in samples taken 10 cm and 20 cm a...

This study determined the location and tissue density of cells immunoreactive for tumour necrosis factor a (TNF a) in intestinal specimens from 24 patients with chronic inflammatory bowel disease (15 with Crohn's disease, nine with ulcerative colitis) and 11 controls. There was significantly increased density of TNF a immunoreactive cells in the lamina propria of both ulcerative colitis and Cro...

BACKGROUND Smoking induces structural changes in the airways, and is considered a major factor in the development of airflow obstruction in chronic obstructive pulmonary disease. However, differences in inflammatory cell distribution between large airways (LA) and small airways (SA) have not been systematically explored in smokers. HYPOTHESIS The content of cells infiltrating the airway wall ...

Recent advances in immunology have highlighted the critical function of pattern-recognition molecules (PRMs) in generating the innate immune response to effectively target pathogens. Nod1 and Nod2 are intracellular PRMs that detect peptidoglycan motifs from the cell walls of bacteria once they gain access to the cytosol. Salmonella enterica serovar Typhimurium is an enteric intracellular pathog...

BACKGROUND Tumour necrosis factor (TNF) alpha and TNF-beta are soluble ligands binding to TNF receptors with similar activities; soluble TNF receptors neutralise TNF activity by acting as inhibitors. Little is known about the cytokine/soluble receptor role in inflammatory bowel disease (IBD). AIMS To test the hypothesis that an imbalance in secretion between TNF and TNF inhibitors plays a rol...

In the fields of biomaterials and tissue engineering simulating the native microenvironment is of utmost importance. As a major component of the microenvironment, the extracellular matrix (ECM) contributes to tissue homeostasis, whereas modifications of native features are associated with pathological conditions. Furthermore, three-dimensional (3D) geometry is an important feature of synthetic ...