Common antigens of human intestinal treponemes and of swine Treponema hyodysenteriae.

The antigenic cross-reactivity between intestinal treponemes of human and swine origin (T. hyodysenteriae and T. innocens) was studied by sodium-dodecylsulfate-polyacrylamide gel electrophoresis and western blotting techniques. Several distinct peptides, ranging in molecular weight from 14,400 to about 150,000 daltons, were recognized by SDS-PAGE analysis of twelve human and two swine hemolytic intestinal treponemes. Thirty antigenic bands were develope by homologous antiserum against treponeme D87, one of 12 human intestinal hemolytic treponemes isolated in our laboratory. An identical number of cross-reacting antigens was found when Western blots of human treponemes D87 were tested with antisera against ten other human treponemes or with antisera against swine treponemes (T. hyodysenteriae, T. innocens). Similar results were obtained when Western blots of swine T. hyodysenteriae were tested for cross-reactivity with antisera against all human intestinal treponemes

Lymphatic vessels in colorectal cancer and their relation with inflammatory infiltrate

PURPOSE: The aim of this study was to determine why colorectal tumors confined to submucosa rarely metastasize. Under normal conditions, the submucosa contains many large lymphatic vessels with thin walls that would presumably favor the spread of cancer cells through the lymphatic system. METHODS: Specimens of colorectal cancer tissue, the border between tumor and normal tissue, and normal tissue were obtained from patients undergoing radical resection of colorectal cancer. The material was embedded in methacrylate resin for light microscopy and Epon® for transmission electron microscopy examination. Light microscopy observations were routinely performed on serial sections. RESULTS: No lymphatic vessels were ever found in the tumor mass. The border area contained peritumoral inflammatory infiltrate of variable thickness. Where submucosal lymphatic vessels came into contact with peritumoral inflammatory infiltrate, they were profoundly altered: their endothelium was fragmented, and their walls were disrupted. These altered lymphatic vessels were almost always accompanied by mast cells, which were observed in the process of degranulating toward the lymphatic endothelium. No such alterations were detected in blood vessels. CONCLUSION: Our results suggest that mast cells, probably influenced by inflammatory infiltrate and/or colorectal cancer cells, destroy lymphatic vessels, which prevents cancer cells from spreading through the lymphatic system

Bcl-2/bax mRNA expression ratio as prognostic factor in low-grade urinary bladder cancer

Apoptotic cell death represents an important mechanism for the precise regulation of cell numbers, and a defence mechanism against tumoral cell. bcl-2 and bax genes are known to be involved in the control of apoptotic pathways; in particular, the ratio between bcl-2 and bax represents a cell rheostat that is able to predict a cell's response toward life or death to an apoptotic stimulus. In the present study we investigated the role of bcl-2 and bax gene expression in a panel of 37 low-grade tumours of the urinary bladder, and correlated the expression of these genes to the prognosis of patients in a follow-up of more than one year. We found that levels of bax expression higher than bcl-2 in bladder tumours well correlates to a better outcome for patients. Early relapses are much more frequently observed in those patients whose tumours express more bcl-2 than bax mRNA. We conclude that the bcl-2/bax expression ratio may be considered as a marker for disease progression in low grade bladder tumours, independently of clinical staging and histological grading