Pension Reform and Retirement in Alaska

A truism in Alaska regarding nearly everything, but especially politics and economics, is that Alaska is about two years behind the rest of the nation. When one looks at pension reform in the public sector, it would appear that Alaska is even farther behind its sister states in attempting to ‘fix the pension problem.’ Prior to 2006, Alaska was recognized as having one of the better public employee pension systems, a defined-benefit program that included a lifetime monthly pension payment as well as an excellent medical program

Regional lymph node response to homologons and heterologous transplants of tumor and normal tissues in the cheek pouch of the hamster

Thesis (Ph.D.)--Boston UniversityThe golden hamster, Mesocricetus auratus, is unique in that it frequently accepts not only homografts but even heterografts of normal and malignant tissues. One of the many theories a tterpting an explanation of this phenomenon, namely that lymphatic tissues that drain the sites of imphntation do not respond in a t;rpicol fashion, motivated this study. Thus, the weight changes ,and the c;'tolof'ical variations of the superficial cervical nodes in response to homologous and heterologous normal and malignant tissue transplants in the cheek pouch of the hamster were studied. The major objectives were: (1) to determine if there be any "defect" in the hamster's lymphatic tissue response to the various transplants; (2) to investigate the effects of the grafts on the large lymphoid cells of the cortex and on the plasma cells of the medulla; and ( 3) to investigate the feasibility of employing the histological picture of a regional node draining the site of a tumor heterotransplant as a base line for anti-tumor studies during the cortisone conditioning. [TRUNCATED

Microvascular pericyte contractility in vitro: comparison with other cells of the vascular wall

Collagen lattices containing bovine retinal pericytes (RPs), vascular smooth muscle cells (VSMCs), pulmonary microvessel endothelial cells (PMECs), or aortic endothelial cells (AECs) were prepared and contraction was quantitated by measuring the resulting change in lattice area. VSMCs were the most efficient at lattice contraction followed by RPs and then PMECs. AECs did not contract the lattices. To document further that these observations represent contraction, cells were grown on inert silicone rubber sheets. Substratum wrinkling was indicative of tension development and quantitated as percent of cells contracted. RPs were more contractile than PMECs, and AECs were incapable of developing tension. VSMCs were less contractile than RPs, unlike the comparative contractility observed with the lattice system. Alteration of actin-containing filaments by cytochalasin B significantly reduced RP contraction of silicone rubber and inhibited their contraction of collagen lattices in a dose-dependent manner. Rhodamine-phalloidin staining of contracting RPs revealed microfilament bundle orientations that suggested their association in the force applied for contraction. RP, VSMC and PMEC contraction of collagen lattices was directly proportional to the concentration of fetal calf serum. Also, RP contraction was greater in calf serum than calf plasma-derived serum, an indication that RPs respond to substances that appear continuously and episodically in blood. These in vitro findings support the theory that pericytes in vivo are contractile but that endothelial cells may also contribute to microvascular tonus

Thromboxane Modulates Endothelial Permeability

The study tests the role of thromboxane in modulating microvascular permeability in vitro. Cultured monolayers of bovine aortic endothelial cells were challenged with the thromboxane (Tx) mimic U46619. This led to disassembly of actin microfilaments, cell rounding, border retraction and interendotheHal gap formation. Pretreatment with the Tx receptor antagonist SQ 29,548 prevented the Tx mimic-induced cytoskeletal changes. The Tx mimic also altered endothelial cell barrier function. Increased permeability was indicated by the increased passage of labelled albumin across monolayers cultured on microcarriers, relative to untreated endothelial cells (p < 0.05). Furthermore, electron microscopy of endothelial cells cultured on the basement membrane of human placental amnion indicated increased permeability based on wide, interendotheHal gap formation and transit of the tracer horseradish peroxidase. Quantification of interendothelial gaps revealed an eleven-fold increase with the Tx mimic relative to untreated endothial cells (p < 0.05) and prevention by pretreatment with the Tx receptor antagonist (p < 0.05). These data indicate that Tx directly modulates the permeability of endothelial cell in vitro

Rapid vascularization of starchâ poly(caprolactone) in vivo by outgrowth endothelial cells in co-culture with primary osteoblasts

The successful integration of in vitro-generated tissues is dependent on adequate vascularization in vivo. Human outgrowth endothelial cells (OECs) isolated from the mononuclear cell fraction of peripheral blood represent a potent population of circulating endothelial progenitors that could provide a cell source for rapid anastomosis and scaffold vascularization. Our previous work with these cells in co-culture with primary human osteoblasts has demonstrated their potential to form perfused vascular structures within a starch–poly(caprolactone) biomaterial in vivo. In the present study, we demonstrate the ability of OECs to form perfused vascular structures as early as 48 h following subcutaneous implantation of the biomaterial in vivo. The number of OECderived vessels increased throughout the study, an effect that was independent of the OEC donor. This finding of rapid and thorough OEC-mediated scaffold vascularization demonstrates the great potential for OEC-based strategies to promote vascularization in tissue engineering. OECs have the potential to contribute to host-derived scaffold vascularization, and formed vascular structures at a similar density as those arising from the host. Additionally, immunohistochemical evidence demonstrated the close interaction between OECs and the co-cultured osteoblasts. In addition to the known paracrine activity osteoblasts have in modulating angiogenesis of co-cultured OECs, we demonstrate the potential of osteoblasts to provide additional structural support for OEC-derived vessels, perhaps acting in a pericyte-like role.The authors would like to thank Mrs B Pavic and Mrs U. Hilbig for their excellent technical assistance. This work was financially supported by grants from the European Commission (EXPERTISSUES Contract No. 500283-2) and the German Federal Ministry of Education and Research, BMBF (German-Chinese Cooperation in Regenerative Medicine; Contract No. 0315033)