Pericytes are defined by their location in vivo; the pericyte partially surrounds the endothelial cell of the microvessel and shares a common basement membrane with it. As an integral part of the microvasculature, pericytes play a fundamental role in maintaining local and tissue homeostasis. Current evidence also suggests that pericytes function as progenitor cells capable of differentiating into a variety of different cell types including osteoblasts, chondrocytes and adipocytes. It is now apparent that cells resembling microvascular pericytes, and termed 'pericyte-like' cells, have a widespread distribution in vivo. Pericyte-like cells have been identified in the inner intima, the outer media, and in the vasa vasora of the adventitia of large, medium and small human arteries (1, 2). Moreover, recent studies have suggested that these cells may be responsible, at least in part, for mediating the calcification commonly associated with atherosclerosis (1, 3, 4). In this review, we a) examine the evidence that microvascular pericytes deposit a bone-like mineralised matrix in vitro, b) compare the morphological and biochemical properties of microvascular pericytes, calcifying vascular cells (CVCs) and 'classical' smooth muscle cells (SMCs) isolated from bovine aorta, c) demonstrate that microvascular pericytes deposit a well-organised matrix of bone, cartilage and fibrous tissue in vivo, and d) discuss recent studies designed to gain a better understanding of how pericyte differentiation is regulated.

To elucidate the role of emotional factors in PKU, 4 subject groups comprised of PKU, retarded and/or brain damaged, psychotic, and normal children were compared on a measure of interaction behavior. On total interaction scores, the PKU group was found to perform significantly poorer than the normals, but significantly better than the psychotics. Differences between the PKU group and retarded and/or brain-damaged group tended toward significance, although on separate comparisons for the 3 social stimulus conditions the differences between these 2 groups were not significant. The PKU group was found to be the most heterogeneous, and the clustering of scores suggested that phenylketonuria is behaviorally not a unitary disorder. Correlations of intelligence criteria and interaction scores for the PKU group further indicated that the interaction measure may tap functions not assessed by standardized IQ tests.

Hispanic populations have higher rates of obesity, elevated triglycerides, and a greater prevalence of diabetes. Long chain polyunsaturated fatty acids (LC-PUFAs) and LC-PUFA metabolites have critical signaling roles that regulate dyslipidemia and inflammation. Genetic variation in the FADS cluster accounts for a large part of the interindividual differences in circulating and tissue levels of LC-PUFAs, with the genotypes most strongly predictive of low LC-PUFA levels at strikingly higher frequencies in Amerind (AI) ancestry populations. In this study, we examined relationships between genetic ancestry and FADS variation, plasma phospholipid levels of LC-PUFAs, anthropometric measures, and circulating metabolic and inflammatory biomarkers in 1,102 Hispanic American participants, representing six distinct ancestry populations from the Multi-Ethnic Study of Atherosclerosis. We demonstrate strong negative associations between AI genetic ancestry and LC-PUFA levels. The FADS rs174537 single nucleotide polymorphism (SNP) accounted for much of the AI ancestry effect on LC-PUFAs, especially for low levels of n-3 LC-PUFAs. Rs174537 was also strongly associated with several metabolic, inflammatory and anthropomorphic traits including circulating triglycerides (TGs) and E-selectin in MESA Hispanics. We further replicated the association with circulating TGs in two additional Hispanic cohorts: the Hispanic Community Health Study/Study of Latinos and the Arizona Insulin Resistance Registry. Our study demonstrates that Amerind ancestry provides a useful and readily available tool to identify individuals most likely to have FADS-related n-3 LC-PUFA deficiencies and associated cardiovascular risk.