Search

A large kindred with X-linked retinitis pigmentosa (XLRP) was investigated clinically and by means of genetic linkage with a view to developing methods of carrier detection and early diagnosis. A restriction fragment length polymorphism, identified by recombinant DNA probe L1.28, showed close genetic linkage to XLRP in this kindred and is a potentially useful marker for the purposes of genetic counselling. [ABSTRACT FROM PUBLISHER]

Cardiac valve interstitial cells are a phenotypically diverse and dynamic population, comprising myofibroblasts, fibroblasts and smooth muscle cells. To understand how these contribute to valve function and to optimize the choice of cells for seeding tissue-engineered valves, we are fingerprinting interstitial cells from all four human heart valves for useful phenotypic markers. We have begun by selecting markers indicated as of interest from previous work on myofibroblast-like cell lines. We show that interstitial cells express a variety of skeletal muscle contractile proteins and the skeletal muscle transcription factor myogenin, but not the related factors MyoD, myf-5 and MRF4, suggesting partial activation of the muscle programme in these cells. Expression of non-muscle isoforms of creatine kinase (CK-B) and AMP deaminase (AMPD2 and AMPD3) was found in contrast to muscle-restricted isoforms. Non-muscle isoforms of alpha- and beta-tropomyosins were detected specifically in contrast to skeletal muscle-specific isoforms. Several members of the Frizzled (FZD) family of Wnt receptors were also detected. In addition, intact cusps of all four valves from pig were capable of contacting to non-receptor and receptor-mediated stimulation in vitro. We conclude that interstitial cells from human heart valves express various sarcomeric proteins, and suggest that these cells have contractile potential due to a unique pattern of expression of both muscle-specific and non-muscle isoforms of metabolic and structural proteins. This may be under the control of myogenin, activated through specific Wnt/FZD signaling. Identifying such molecular markers could prove useful for engineering allogenic non-valve cell sources for seeding the synthetic valve.

Background: Coronary artery bypass grafting (CABG) surgery is associated with systemic inflammation. Activation of neutrophils is a crucial step in inflammation and results in neutrophil sequestration within the tissues. One of the potential advantages of performing off-pump coronary artery bypass (OPCAB) surgery is the attenuation of the systemic inflammatory response. This prospective randomized study compares neutrophil activation in patients undergoing OPCAB versus those undergoing CABG with cardiopulmonary bypass (CPB)., Methods: Twenty patients undergoing primary isolated CABG were randomly divided prospectively into 2 groups: 1 group underwent CABG with CPB, and the other group underwent OPCAB. Central venous blood samples were obtained before skin incision and at 15 minutes, 60 minutes, 2 hours, 5 hours, and 24 hours following the initiation of CPB or application of the stabilization device. Differential white cell counts were measured with routine laboratory techniques. CD11b surface expression on neutrophils was measured by flow cytometry. Interleukin 8 levels in the plasma were measured by enzyme-linked immunosorbent assays., Results: The 2 groups were matched with respect to preoperative and operative characteristics. White cell and neutrophil counts rose in both groups following the operation but were significantly higher in the OPCAB group at 5 hours (P < .001 and P = .002, respectively). Interleukin 8 concentrations were significantly higher in the CPB group at 5 hours following the initiation of CPB (P = .034). CD11b levels were significantly higher in the CPB group at 60 minutes (P = .002)., Conclusion: This prospective randomized study demonstrates that the activation of circulating neutrophils as measured by CD11b expression is lower following OPCAB than in CPB. Although OPCAB is associated with significantly higher neutrophil counts, these neutrophils exhibit fewer activation markers. The lower postoperative neutrophil counts occurring in the CPB group may be explained by the activation and consequent sequestration of the neutrophils in the CPB circuit and tissues.

The transcription factor nuclear factor-kappaB (NF-kappaB) has been implicated in inflammatory and proliferative vascular mechanisms. Activated NF-kappaB has been documented in human atherosclerotic lesions, and its activation in human vascular smooth muscle cells (SMC) by cytokines has been reported. However, intracellular mechanisms mediating NF-kappaB activation in human SMC are poorly understood. The aim of this study was to explore the potential role of reactive oxygen species and oxidant stress as signaling events in cytokine-induced NF-kappaB activation. Western blot analysis revealed the presence of inhibitory protein I-kappaBalpha in resting human aortic SMC, which was rapidly phosphorylated and degraded on exposure to interleukin-1beta (IL-1beta) followed by NF-kappaB translocation to the nucleus. IL-1beta had no effect on two measures of intracellular oxidant stress, fluorescence generated by the oxidation of 2',7'-dichlorodihydrofluorescin to dichlorofluorescein (DCF) or changes in intracellular sulfhydryl content. N-acetylcysteine (NAC) a membrane-permeant antioxidant, which augmented intracellular sulfhydryl content and inhibited H(2)O(2)-induced DCF fluorescence, had no effect on cytokine-induced NF-kappaB activation. In contrast to NAC, the metal chelators pyrrolidine dithiocarbamate and diethyldithiocarbamate attenuated IL-1beta-induced NF-kappaB activation but had no effect on intracellular sulfhydryl content. Treatment of the cells with the oxidant H(2)O(2) caused an increase in DCF fluorescence and decreased intracellular sulfhydryl content but had no effect on I-kappaBalpha or NF-kappaB. In conclusion, this study suggests that oxidant stress may not play a major role in cytokine-induced activation of NF-kappaB in human aortic SMC and that oxidants may not be primary activators of NF-kappaB in these cells.

Objective: We have attempted to demonstrate the induction of inducible nitric oxide synthase in human vascular tissue and define the capacity of different cytokines to induce this enzyme., Methods: Segments of human arteries were stimulated with lipopolysaccharide (10 micrograms/ml), interleukin-1 beta (5 U/ml), tumor necrosis factor-alpha (10 U/ml), and interferon-gamma (200 U/ml). Cytokines were either used alone or in certain combinations, as well as in the presence of L-NG-monomethyl-arginine (100 mumol/l) or cycloheximide (1 mumol/l). Induction was assessed by measurement of mRNA expression, immunocytochemical localisation of the expressed protein, nitric oxide synthase activity and levels of nitrite, a product of nitric oxide formation., Results: PCR analysis showed the presence of mRNA for iNOS in stimulated samples which could be inhibited by cycloheximide. There was positive staining with an antibody against human iNOS in the media of stimulated vessel segments. Stimulated segments were also shown to contain Ca(2+)-independent nitric oxide synthase activity. The cytokines and lipopolysaccharide together gave a significant rise in levels of nitrite in the medium after 36 and 48 h, which was inhibited by L-NG-monomethyl-arginine and cycloheximide. Only interferon-gamma incubated alone was capable of increasing nitrite levels. This effect was enhanced by co-incubation with either interleukin-1 beta, tumor necrosis factor-alpha or lipopolysaccharide., Conclusion: We have shown that increased production of nitrite by human vascular tissue in response to cytokines is associated with induction of iNOS as shown at the molecular and protein levels, and further supported by the presence of increased Ca(2+)-independent nitric oxide synthase activity following cytokine stimulation.

The current turbulence characterizing the health sector has engendered a limited number of state-level experiments to provide health services for the nation's 37 million uninsured. The issues and challenges generated by each program's design and implementation vary. By examining the experience of one such state program, the Washington Basic Health Plan, in some detail, this paper contributes to the policy debate regarding the possible range of solutions available to address the issue of "the uninsured." By analyzing the array of design choices available at the time the program was enacted, and why certain options were chosen rather than others, this paper points to the complex interaction of political dynamics, public policy development, and program implementation.

It is difficult to discuss the expertise needed to effectively manage multiunit health care corporations without examining the different work settings that comprise these organizations. This paper presents a framework to systematically describe the necessary tasks in multiunit corporations. Specific skills and knowledge areas are then described that may be missing from health administration programs' curricula.