Effect of glow discharge surface modification of plasma TFE vascular graft material on fibronectin and laminin retention and endothelial cell adhesion.

The effects of glow discharge surface modification of plasma TFE vascular graft material (plasma TFE, Atrium Medical Corp., Hollis, NH) on the binding and retention of fibronectin and laminin as well as endothelial adherence were examined. The binding of both fibronectin and laminin to plasma TFE increased as a function of protein concentration in the range of 0.02 to 200 micrograms/ml. Binding to plasma TFE was not saturable in this range of protein concentrations. Fibronectin and laminin binding to plasma TFE was time-dependent, reaching a maximal level (1.8 and 3.2 micrograms/cm2 of bound fibronectin and laminin, respectively) after 30 min (fibronectin) and 4 hr (laminin). Binding was not the result of an accumulation of unbound protein in graft interstices since graft prewetting did not alter the amount of either fibronectin or laminin associated with plasma TFE. In addition, binding was not the result of protein modification during radiolabeling, since unlabeled fibronectin and laminin could compete effectively with their iodinated counterparts for binding to plasma TFE. Dissociation of bound fibronectin and laminin from plasma TFE was rapid, and less than 12% remained bound 60 min after washing. Plasma TFE subjected to glow discharge in O2 and carrying negatively charged functional groups on graft surfaces, exhibited a fivefold increase in fibronectin and laminin binding. In addition, more than 85% of the bound fibronectin and laminin was retained 24 hr after washing. The enhanced retention of fibronectin or laminin by these grafts was associated with an increase in endothelial cell adhesion.(ABSTRACT TRUNCATED AT 250 WORDS)     

Stoma coloproctology nurse specialist: a case study

Aims and objectives. The aim of this paper is to provide insight into the role of a Stoma Coloproctology Nurse Specialist. This paper presents the findings of an in‐depth case study of a stoma coloproctology nurse specialist employed in one health board area in Northern Ireland. This case study was part of a larger study exploring innovative nursing and midwifery roles in Northern Ireland. Background. Specialist nursing roles have evolved and developed in response to changing health care needs, patient expectations, changes in professional regulation and government initiatives. Design. A case study approach was adopted. Method. Semi‐structured interviews with the post holder (PH), her line manager and the human resource manager were undertaken. Non‐participant observation of the PH's practice was also carried out. Analysis was undertaken on secondary data such as job specification, annual reports and other documentation relating to the post. Results. Findings illustrate the PH's function and the impact of the role on patient care. Examples of innovative practices relating to providing care, support and guidance for patients and their families were identified; however, limitations to her role were also identified. Conclusions. The PH provides an invaluable service to patients, demonstrating a positive impact on care. However, the findings suggest the importance of establishing clear role boundaries, which may lead to professional growth and practice development. Relevance to clinical practice. Although this study provides a valuable insight into the role of a Stoma Coloproctology Nurse Specialist a number of challenges exist, as the CNS role requires policy and appropriate educational preparation to practice at an advanced level. Further research investigating the development of the CNS role in the clinical setting and its relationship to members of the multi‐professional team would be beneficial.     

Alterations in the regulation of androgen-sensitive Cyp 4a monooxygenases cause hypertension

Hypertension is a leading cause of cardiovascular, cerebral, and renal disease morbidity and mortality. Here we show that disruption of the Cyp 4a14 gene causes hypertension, which is, like most human hypertension, more severe in males. Male Cyp 4a14 (-/-) mice show increases in plasma androgens, kidney Cyp 4a12 expression, and the formation of prohypertensive 20-hydroxyarachidonate. Castration normalizes the blood pressure of Cyp 4a14 (-/-) mice and minimizes Cyp 4a12 expression and arachidonate omega-hydroxylation. Androgen replacement restores hypertensive phenotype, Cyp 4a12 expression, and 20-hydroxy-arachidonate formation. We conclude that the androgen-mediated regulation of Cyp 4a arachidonate monooxygenases is an important component of the renal mechanisms that control systemic blood pressures. These results provide direct evidence for a role of Cyp 4a isoforms in cardiovascular physiology, establish Cyp 4a14 (-/-) mice as a monogenic model for the study of cause/effect relationships between blood pressure, sex hormones, and P450 omega-hydroxylases, and suggest the human CYP 4A homologues as candidate genes for the analysis of the genetic and molecular basis of human hypertension.