Authors:M. Constantinovits, F. Sipos, B. Molnár, Zs Tulassay and Györgyi Műzes
Gut-associated lymphoid tissue (GALT) is supposed to play an integral role in the organization of colonic repair mechanisms. Majority of the GALT is composed of isolated and aggregated lymphoid follicles distributed throughout the intestines. These lymphoid follicles, including Peyer’s patches of the small, and isolated lymphoid follicles (ILFs) of both the small and large intestines, are composed of a specialised follicle associated epithelium overlying a subepithelial dome containing numerous dendritic cells, macrophages, T and B cells. Within inflammatory conditions the number, the diameter and the density of ILFs are increasing. Follicles are involved not just in immune surveillance, but their presence is also indispensable for normal colonic mucosal regeneration. Regarding mucosal repair the relation of ILFs to bone marrow derived stem cells, follicular dendritic cells, subepithelial myofibroblasts and crypt formations, and the putative organizer role of ILFs have not been clarified yet.
Authors:P. Sipos, K. Hagymási, A. Lugasi, Edit Fehér, F. Örsi and A. Blázovics
An experimental surgical model was developed in rats after a short term alimentary induced hyperlipidemy to study the direct effect of bile on the colonic mucosa, with regard to the cancerogenic properties of lipid rich diet. The purpose of this study was to light on the role of fatty acid alteration and lipid peroxidation processes of bile in the epithelial cell damage. Animals were fed with normal (group A) and fat rich diet (group B) for 10 days and then bile samples were collected by the cannulation of the common bile duct in deep anaesthesia. The circulation preserved colons of control rats were treated either with bile from the control or hyperlipidemic rats. The treatment was carried out for 30 minutes. The electronmicroscopic alterations of epithelial cells (both enterocytes and goblet cells) caused by bile from hyperlipidemic rats were significantly greater than that of controls. Unfavourable changes of the redox state of the colonic mucosa were also detected both in the hyperlipidemic and bile treated groups. A significant increase was observed in the free-SH concentration of the two bile treated groups against the untreated animals. The changes could be explained among others by the modified bile fatty acid composition. The present study supports that the alimentary modified bile can influence the structure of the epithelium of colonic mucosa and it can be one of the inducing factor of carcinogenesis.
Authors:B. Horváth, F. Peles, A. Szél, R. Sipos, Á. Erős, E. Albert and A. Micsinai
The aim of the study was the identification and characterisation of coagulase-positive Staphylococcus bacteria obtained from food matrices by mass spectrometry and molecular methods. A total of 46 coagulase-positive Staphylococcus isolates were collected from different foodstuffs. The Staphylococcus isolates were identified by MALDI-TOF MS and confirmed by the presence and sequence analysis of the Staphylococcus protein A gene. Staphylococcal enterotoxin genes were also investigated by multiplex PCR. Based on the identification of strains by the MALDI-TOF MS technique and spa-typing, all strains were identified as Staphylococcus aureus. Based on their MS peak profiles, the isolates matched the spectra of three S. aureus reference strains in the Bruker MALDI Biotyper database, with identification scores higher than 1.999 in the case of all 46 (100%) isolates. The isolates showed great genetic variability. Twenty spa types were identified, from which most lineages are capable of colonizing humans. Fifty percent of the strains harboured at least one of four enterotoxin genes (seg, seh, sei, and ser), but none of the classical enterotoxin genes could be detected.