Diffusional motion as a gauge of fluidity and interfacial adhesion. Supported alkylphosphonate monolayers.

We report on the use of diffusion measurements to gauge the fluidity and surface binding properties of a molecular monolayer. The monolayer film consists of octadecyl-1-phosphonic acid (ODPA) and controlled amounts of a lyso-phosphatidic acid tagged with the fluorescent probe BODIPY (BLPA). The monolayer films were formed using a Langmuir-Blodgett (LB) trough and deposited onto a glass slide. Monolayer morphology was characterized during film formation using Brewster angle microscopy (BAM). Fluorescence Recovery After Photobleaching (FRAP) microscopy was used to measure translational diffusion of BLPA and Fluorescence Anisotropy Decay Imaging (FADI) was used to measure rotational diffusion of the BLPA chromophore. These results provide information on the motional freedom of the probe and, importantly, on the strength of interaction between the probe and the support. Compositional variations in the monolayer give rise to changes in constituent dynamics that reflect intermolecular interactions.

Lipid adlayer organization mediated by a liquid overlayer.

We report on the formation of a chemically bound 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) monolayer on modified Au and silica surfaces, and changes in the organization of the interfacial lipid layer associated with immersion in aqueous solution. We have studied the interface using steady state and time resolved fluorescence spectroscopy, water contact angle and optical ellipsometry measurements, and electrochemical methods. Our data reveal that the DMPC adlayer in contact with air forms a relatively well organized interface that mediates the rotational motion of perylene. In the presence of an aqueous overlayer, perylene reorientation becomes more rapid, consistent with a reduction in the organization of the interfacial lipid adlayer. One implication of this finding is that the interfacial adlayer is less than a uniform monolayer, which is confirmed by electrochemical data. Our data underscore the importance of water in mediating the organization of interfacial lipid adlayers.

From book to bedside: putting evidence to use in the care of the elderly.

BACKGROUND: Infusion of research findings into clinical practice is a challenging part of the research process. Because the length of time between discovery and use of knowledge averages 20 years, methods are needed to speed translation of research findings into practice. Few efforts have been made to coordinate the generation of new knowledge with the dissemination of findings from research to improve care of the elderly. RESEARCH-BASED PRACTICE PROTOCOLS: The Research Development and Dissemination Core (RDDC) of the Gerontological Nursing Interventions Research Center (GNIRC) at the University of Iowa emphasizes development of research-based (RB) protocols, which requires collecting relevant literature, critiquing studies, and synthesizing research findings for practice. GNIRC-generated research is disseminated to nurses in practice, and the RDDC links nurses who identify clinical problems in care of the elderly with GNIRC scientists. Currently, 19 RB protocols are offered for dissemination through the RDDC, and 5 protocols are under development. Implementation and evaluation of research-based practices on "Split Thickness Skin Graft Donor Site Care" and "Nasogastric/Nasointestinal Tube Placement" are described. CONCLUSIONS: Lessons learned on the basis of experience in disseminating and implementing research-based practices include the necessity of tailoring them to the local needs of various clinical settings in which they are used, reinfusing them periodically to keep staff motivated, and making them consumer friendly. The challenge remains to integrate these practices into the fiber of organizations and to keep staff educated and motivated to carry out research-based practices to improve the care of the elderly.

Split-thickness skin graft donor site care: a quantitative synthesis of the research.

Split-thickness skin grafting (STSG) is a frequently used reconstructive technique but is associated with a large variation in practice. The purposes of this article are to integrate and synthesize the available empirical evidence regarding STSG donor site dressings, identify which dressings are associated with the best outcomes, and provide practice recommendations. This review of 33 studies found transparent film to be the best dressing for the care of STSG donor site wounds. Transparent film was associated with one of the fastest healing rates (9.47 days), a smooth epithelialized surface, a low infection rate (10 out of 394 patients or 3%), the least amount of pain (1.59 on 0 to 10 scale), and minimal cost ($.005 per square inch) when compared with other dressings.

[Intracranial manifestations of Langerhans-cell histiocytosis. Nuclear magnetic resonance findings]. / Intrakranielle Manifestationen der Langerhanszell-Histiozytose. Kernspintomographische Befunde.

We report on 3 patients with intracranial manifestations of Langerhans cell histiocytosis (LH). The results are correlated with histological, clinical and radiological reports on some 70 patients described in the literature as suffering from intracranial LH. Two different morphological pictures can be differentiated. First, typical infiltrates can be seen by microscopy; these can be located in every part of the brain, but are seen mainly in the region of the hypothalamus. These infiltrations are shown as space-occupying lesions with Gd-DTPA enhancement. The other manifestation is a demyelinized lesion with a sparse infiltration of Langerhans cells. These lesions, which are located mainly in the region of the nucleus dentatus of the cerebellum and the brain stem, show increased signal intensity in the T2 sequence and no Gd-DTPA enhancement on MRI.

Expression of Epstein-Barr virus nuclear antigen 1,2A and 2B in the baculovirus expression system: serological evaluation of human antibodies to these proteins.

The Epstein-Barr virus encoded nuclear antigens 1,2A, and 2B (EBNA 1, EBNA 2A, and EBNA 2B) were expressed in a baculovirus system. The full length recombinant proteins were recognized by polyclonal rabbit sera and by human sera. An immunofluorescence (IF) test for the differentiation between EBNA 1 and EBNA 2 antibodies in human sera was established with the expressed proteins. None of 55 sera of patients with infectious mononucleosis (IM) had anti-EBNA 1 antibodies while 36 of these sera had anti-EBNA 2A antibodies. Conversely, 47 of 51 sera from EBV-positive healthy carriers had anti-EBNA 1 antibodies and 18 of these sera had anti-EBNA 2A antibodies. The sensitivity and specificity of the EBNA 1 IF for the diagnosis of IM were higher as compared to conventional anti-complement immunofluorescence (ACIF). In the IF test differentiation between type A and type B EBV infection was only possible in sera from the IM patients. An immunoblot (IB) with low amounts of baculovirus expressed EBNA 2A and EBNA 2B antigen was carried out. Twenty-nine of 31 sera from IM patients or from healthy carriers with EBNA 2 antibodies reacted predominantly with EBNA 2A, whereas a known type B serum reacted strongly with EBNA 2B than with EBNA 2A.