Effect of Mediterranean diet on the expression of pro-atherogenic genes in a population at high cardiovascular risk.

Experimental and epidemiological studies have demonstrated the beneficial effects of the traditional Mediterranean diet (TMD) on the incidence and progression of atherosclerosis. Several genes play a major role in determining atherosclerosis susceptibility. We compared the short-term effects of two TMD diets versus a control diet on the expression of pro-atherogenic genes. One TMD diet was supplemented with virgin olive oil (VOO) (TMD+VOO) and the other with nuts (TMD+nuts). Gene expression was analyzed in monocytes from 49 asymptomatic high cardiovascular-risk participants (23 men, 26 women), aged 55-80 years. Monocytes were isolated from blood before and 3 months after dietary intervention. We analyzed the expression of genes involved in inflammation [cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2) and monocyte chemoattractant protein (MCP-1)], genes involved in foam cell formation [low-density lipoprotein receptor-related protein (LRP1), LDL receptor and CD36], and genes involved in thrombosis [tissue factor (TF) and tissue factor pathway inhibitor (TFPI)]. We found that TMD+VOO intervention prevented an increase in COX-2 and LRP1, and reduced MCP-1 expression compared to TMD+nuts or control diet interventions. TMD+nuts specifically increased the expression of CD36 and TFPI compared to TMD+VOO and control diet intervention. Our findings showed that the Mediterranean diet influences expression of key genes involved in vascular inflammation, foam cell formation and thrombosis. Dietary intervention can thus actively modulate the expression of pro-atherothrombotic genes even in a high-risk population.

Lines of cell differentiation in solitary fibrous tumor: an ultrastructural and immunohistochemical study of 10 cases.

BACKGROUND: Solitary fibrous tumor (SFT) is a rare ubiquitous mesenchymal neoplasm of probable fibroblastic type with a prominent hemangiopericytoma-like vascular pattern. Since their initial description as arising from the pleura, SFTs have been reported in many extraserosal sites. It is now accepted that this neoplasm is derived from mesenchymal cells but its histogenesis is still not known. METHODS: The authors gathered clinical data on 10 patients with SFT. Tissue microarrays were constructed to perform inmunohistochemical tests and we reviewed hematoxilin-eosin-stained slides. Electron-microscopically collected samples were fixed with formalin or Karnovsky reactive and embedded in epoxy resin. RESULTS: The histopathological review showed varying degrees of cell density and mitotic activity, which correlated with clinical behavior. Immunohistochemically most tumors stained positively for vimentin, CD99, and CD34. Ultrastructural study showed some degree of myofibroblastic differentiation in all cases and focal smooth muscle features. In addition, 9 cases showed perivascular undifferentiated cells. CONCLUSION: SFT is an uncommon neoplasm with different histological patterns and clinical behavior. The authors hypothesize that the perivascular undifferentiated cells that most cases showed might correspond to a quiescent stage of adult stem mesenchymal cell and could be the target of the molecular aberrations implied in its pathogenesis.

Undifferentiated perivascular cells in myxoid mesenchymal tumors: an ultrastructural study.

The current WHO classification of soft tissue tumors is based on the lineage of differentiation of the proliferating cells. Since mature mesenchymal cells have a broad phenotypic plasticity it has been considered unnecessary to recur to a hypothetical stem cell to explain the origin of these neoplasms. In spite of this assumption, the target cell of the oncogenic mutations in mesenchymal tumors is still a controversial item. Myxoid mesenchymal tumors constitute a heterogeneous group of neoplasms sharing in an ample mucinous matrix that separates neoplastic cells and facilitates their single submicroscopic study under electron microscopy examination. The authors have studied, by electron microscopy, 74 myxoid mesenchymal tumors, including a large variety of nosologic entities, to assess their madurational gradient. In 43 of 74 cases, a common element has been found: medium-sized cells, with high nucleo-cytoplasmic ratio, lacking lineage specific features, which were arranged around the capillary vessels. In some cases, the authors were able to demonstrate gradual differentiation in these cells, as they moved away from the vessels. These features support the hypothesis that at least some mesenchymal tumors originate from perivascular undifferentiated cells. In addition, the findings might contribute to define both topographic and morphologic characteristics of adult stem mesenchymal cells.