Lymphatic vessels assessment in feline mammary tumours

BACKGROUND: The lymphatic vessels play a crucial role in a variety of human cancers since tumour cell lymphatic invasion significantly influences prognosis. It is not known if pre-existing lymphatics are enough for tumour dissemination or de novo development is necessary. VEGFR-3 is an angiogenetic mediator for both lymphatic and blood vessels during embryonic development, and only for lymphatics after birth. VEGF is a mediator of both vasculogenesis and angiogenesis, regulates the growth of lymphatics in various experimental models, and is produced in many solid tumours. CD44 mediates hyaluronic acid (HA)-dependent cell adhesion: besides promoting invasion, this interaction also supports neoangiogenesis that indirectly stimulates tumour cell proliferation. The expression of VEGF-C (Vascular Endothelial Growth Factor – C), its receptor VEGFR-3 and CD44, were studied on feline mammary samples to assess the importance of lymphangiogenesis and lymphangiotrophism in neoplasia. METHODS: Samples were taken from six normal mammary glands (NMG), ten benign (BT) and 32 malignant (MT) tumours. Immunohistochemical laminin/VEGFR-3 double stain, VEGF-C and CD44 stains were applied to 4 μm-thick sections, and their expression evaluated in intratumoral/extratumoral and intramammary/extramammary fields. RESULTS: All groups revealed a higher number of lymphatics in the extratumoral/extramammary areas. VEGF-C expression in the epithelium paralleled the number of positive vessels in the NMG, BT and MT, whereas VEGF-C higher expression was noted in the intratumoral fields only in infiltrating MT. CD44 score was lower in extratumoral than intratumoral fields in tumours and showed a significant increase in extramammary/extratumoral fields from NMG to MT. Pearson test showed a significant and inversely proportional correlation between CD44 expression and the number of lymphatic vessels with VEGFR-3 in malignant infiltrating tumours. CONCLUSION: The number of both VEGFR-3 positive and negative lymphatics in the extratumoral and extramammary stroma was significantly higher than intratumoral and intramammary fields respectively in the NMG, BT and MT. This suggests a scant biological importance of intratumoral lymphatics while their higher number is due to the concentration of existing vessels following compression of the extratumoral stroma in spite of a non demonstrable increase from NMG to MT. The tumour model employed provided no evidence of lymphangiogenesis, and metastasis in the regional lymph node develops following the spread through the pre-existing lymphatic network

Black Men and the Decision to Marry

The purpose of this descriptive study is to understand the decision to marry among a sample of 52 married Black men. Qualitative inquiry was used to explore this issue. The men noted five factors that encouraged marriage: wife\u27s characteristics, spirituality, desire to be together, readiness to marry, and encouragement from others. Five barriers to marriage were personal reservations, perceived loss of freedom, disapproval from others, prior relationship experiences, and finances. If they had to make the choice to marry again, 44% reported they would marry at the same time, 30% would opt to marry later, and 23% would select to marry earlier. Three percent of men would not choose to marry again. Implications are discussed

Isolation and Characterization of Intestinal Epithelial Cells from Normal and SIV-Infected Rhesus Macaques

Impairment of intestinal epithelial barriers contributes to the progression of HIV/SIV infection and leads to generalized HIV-induced immune-cell activation during chronic infection. Rhesus macaques are the major animal model for studying HIV pathogenesis. However, detailed characterization of isolated rhesus epithelial cells (ECs) from intestinal tissues is not well defined. It is also not well documented whether isolated ECs had any other cell contaminants from intestinal tissues during the time of processing that might hamper interpretation of EC preparations or cultures. In this study, we identify and characterize ECs based on flow cytometry and immunohistochemistry methods using various enzymatic and mechanical isolation techniques to enrich ECs from intestinal tissues. This study shows that normal healthy ECs differentially express HLA-DR, CD23, CD27, CD90, CD95 and IL-10R markers. Early apoptosis and upregulation of ICAM-1 and HLA-DR in intestinal ECs are thought to be the key features in SIV mediated enteropathy. The data suggest that intestinal ECs might be playing an important role in mucosal immune responses by regulating the expression of different important regulatory and adhesion molecules and their function