High microvascular blood volume is associated with high glucose uptake and tumor angiogenesis in human gliomas.

The purpose of this investigation was to elucidate the association between microvascular blood volume and glucose uptake and to link these measures with tumor angiogenesis. We demonstrate a regionally specific correlation between tumor relative microvascular blood volume (CBV), determined in vivo with functional magnetic resonance imaging techniques, and tumor glucose uptake determined with fluorodeoxyglucose positron emission tomography. Regions of maximum glucose uptake were well matched with maximum CBV across all patients (n = 21; r = 0.572; P = 0.023). High-grade gliomas showed significantly elevated CBV and glucose uptake compared with low-grade gliomas, (P = 0.009 and 0.008, respectively). Correlations between CBV and glucose uptake were then determined on a voxel-by-voxel basis within each patient's glioma. Correlation indices varied widely, but in 16 of 21 cases of human glioma, CBV and glucose uptake were correlated (r > 0.150). These measures were well correlated in all cases when comparing healthy brain tissue in these same patients. Tumor vascularity, as determined immunohistochemically and morphometrically on clinical samples, revealed statistically significant relationships with functional imaging characteristics in vivo. Regional heterogeneities in glucose uptake were well matched with functional magnetic resonance imaging CBV maps. Our findings support the concept that there is an association of microvascular density and tumor energy metabolism in most human gliomas. In addition, the findings are likely to have important clinical applications in the initial evaluation, treatment, and longitudinal monitoring of patients with malignant gliomas.

Explanation in nursing science.

Is it possible to explain that which we do in nursing and in most human sciences? Is explanation/prediction our goal? Instead, should the goal be understanding/interpretation? Might the goal be both understanding and explanation? Is nursing, as a human science, focused on individuality or generalizability? This paper explores the current debate in relation to explanation and understanding. The traditional view of explanation is addressed as is the dichotomous view of understanding. A third view on explanation and understanding, designed by Miller (1983), is offered as a possible middle ground between the two diverse views as an approach for nursing as a human science.

Rules and regulations governing nursing education.

The purpose of this article is to report on a national survey of the 51 state boards of examiners in the United States that govern and regulate nursing education. Data were gathered from the written rules and regulations of each of the state agencies, and content analysis was performed focusing on the following categories: qualifications (State board members, program directors, faculty, and preceptors); roles and responsibilities (state board members, faculty, preceptors, and clinical agencies); and process and content of the nursing education curriculum and program. Findings of the study indicate specific problem areas in the regulating of basic nursing education programs. The following were among the major issues identified: (1) educational qualifications for board membership are virtually nonexistent, (2) in many situations different requirements exist for various types of programs, and (3) there is great disparity from state to state regarding both the content deemed as necessary in nursing education and in the mandated process of that education. The investigators noted that several patterns lend credence to a need for a national plan regarding the state regulation of basic nursing education.

Activities and interactions of baccalaureate nursing students in clinical practica.

Basic nursing education is governed by individual state rules and regulations lacking in uniformity across the United States and based on unstated and perhaps mistaken assumptions. At the same time, there is increasing evidence of problems and difficulties with the current traditional model of nursing education. Before proposing changes in said model, the authors chose to examine what it is that a nursing student does in a clinical area. The perspective of activities and interactions was chosen to illustrate, through a nonparticipant observation study, the patterns and utilization of time during a scheduled clinical experience for baccalaureate nursing students. The goal of the study was to determine who, other than the client/patient, influences the student learning at the clinical site and how learning time is spent. Two schools (one private and one public) and nine clinical sites with 37 observations were used to collect the data for this study. Findings are best summarized in four (overlapping) categories of school time, registered nurse (RN) staff time, hospital staff time, and supervised time. School time, or time spent interacting with the instructor, another student, and/or the student on his/her own in the practice setting (time exclusive of staff input) constituted 84 per cent of all time. RN staff time that was time spent with either the primary nurse or other RNs on the unit used 10 per cent of the student time, Fourteen per cent of student time was spent in hospital staff time, which includes interactions with any nursing staff or other hospital personnel.(ABSTRACT TRUNCATED AT 250 WORDS)

The need for information on assistive devices by older persons.

Analyzing the results of the first 110 interviews from the Rehabilitation Engineering Research Center on Aging's Consumer Assessments Project, this study examined subjects' responses to the question, "Can you think of a device you would like to have that you haven't been able to find--a device that may not have yet been developed?" Each response was compared to the results of a Hyper-ABLEDATA search for similar existing products. When asked to propose a new device, 43 subjects (39% of the sample) responded with suggestions. In all instances, however, the respondents suggested devices that are already available. These findings indicate that subjects did not have up-to-date or complete information on the assistive devices that could improve their quality of life.

Design of hand-held remotes for older persons with impairments.

The University at Buffalo Rehabilitation Engineering Research Center on Aging (RERC) developed two prototype television remote control devices (remotes), designed to address the needs of older persons with some visual and/or fine motor impairment. The prototype remotes have large buttons, large numbers and characters on the buttons, and high color contrast between the buttons and background. One remote has 15 buttons, and one has 6 buttons. The purpose of this study was to test these prototype remotes against two commercially available remotes for user speed, accuracy, and satisfaction. One of the commercially available remotes has small buttons and small print but more features than the prototype remotes; this device came with the television used in the study. The second commercially available remote has somewhat larger buttons, but still smaller than the ones on the RERC prototypes. Thirty elders with impairments participated in testing the remotes in a simulated living room setting. The order in which the remote devices were presented to the subjects was randomly determined. Results indicated a significant difference among remotes in number of errors made; subjects made the fewest number of errors on the 15-button prototype remote. There was no significant difference among remotes in speed. There were significant differences in user satisfaction: users preferred the 15-button prototype device. Subjects were asked if they would rather have more features and small buttons on their remote, or fewer features and larger buttons; almost three-fourths of the sample desired fewer features and larger buttons.

Psychological determinism and the evolving nursing paradigm.

The purpose of this article is to explore three behaviorist theories and their roles within the evolving paradigm of nursing. The authors suggest that the behaviorist theories of locus of control, self-efficacy, and the health belief model are derived from deterministic philosophical premises. These premises are in direct conflict with the premise of free will. As interpreted by the authors and many others, the emerging paradigm of nursing relies on the free will of the individual, the ability of the individual to choose for himself/herself what course of action to take, to avoid, or to pursue. The authors address the psychological deterministic philosophical premises within the three theories and utilize nursing theories to compare and contrast the views of free will and determinism. Finally, they suggest that the use of borrowed and applied theories should decline when nurse scientists are true to the philosophical assumptions of theories within nursing science.

The dilemma of nursing science: current quandaries and lack of direction.

The theme of this paper is the need to address the central question in nursing science. It is hypothesized that in the absence of a central, unifying question, the view of nursing as an applied science, the current research methodological debate, and the social policy statement definition of nursing have hindered nursing's ability to advance the science of nursing. The authors suggest that the terminology of applied science has been wrongfully interpreted as immediate application to nursing practice, that the research methodological debate has occurred because the focus of research efforts is on the means and not the end, and that the policy statement implies a stimulus-response approach to human behavior.

The nature of scientific truth.

The purpose of this article is to share with the readers the authors' views on the need for a philosophical foundation in nursing scholarship. The philosophical premises of realism, idealism, and empiricism are discussed. In addition, the research methods most appropriately used with each philosophical stance are identified and discussed. The authors strongly suggest that nursing epistemology will not advance along the lines of good science until all nursing theorists, thinkers, and philosophers identify their underpinning philosophical positions prior to the discovery of theory, through research and other scientific endeavors. A nursing science fiction account of discovery and theory is used to illustrate the points made within the article.

Organ donation as gift exchange.

Organ donation, considered by sociologists as a type of gift exchange, involves moral, social, psychological, religious and legal issues. This gift exchange paradigm can be used as a framework to understand donor and recipient issues, cadaveric organ donation and the importance of the role of nurses during organ procurement.

Cruciate retained and excised total knee arthroplasty. A comparative study in patients with bilateral total knee arthroplasty.

A comparative study of posterior cruciate ligament retention and excision was conducted in patients who underwent bilateral total knee arthroplasty using the total condylar modifier prosthesis. The posterior cruciate ligament was excised in one knee and was retained in the other knee in 28 patients. Postoperative results were assessed using the Hospital for Special Surgery Knee Evaluation Score. In addition, stair activity was tested to determine whether there was preferential dependence on one of the two knees. There was no significant difference between the posterior cruciate ligament retained or excised knees in terms of postoperative Hospital for Special Surgery Knee Evaluation Score. Patients who ascended and descended stairs with one leg at a time tended to prefer the posterior cruciate ligament retention side. Those who could use each leg in sequence to go up and down stairs, however, did not show preferential dependence on either knee.

Transligamentous motor branch of the median nerve discovered during endoscopically assisted carpal tunnel release.

The endoscopically assisted carpal tunnel release is an alternative to open procedures. A case is presented in which a transligamentous motor branch of the median nerve exits from the main trunk in a proximal and ulnar location. It is discovered from within the carpal canal during an endoscopically assisted procedure. The authors suggest adherence to strict principles to minimize potential complications in the rare event of an anatomic anomaly.

Membrane recycling due to low and high rates of nerve stimulation at release sites in the amphibian (Bufo marinus) neuromuscular junction.

The activity-dependent labelling of motor nerve terminals with the dye FM1-43 has been used to estimate the relative levels of membrane recycling (due to synaptic vesicle exocytosis and recovery) at release sites in response to 1,200 nerve stimulations delivered at either low (0.5 Hz) or high (30 Hz) frequency. Dye in terminals appears as fluorescent spots distributed along the terminal branches; each spot is thought to be a cluster of labelled vesicles associated with a release site. Relative fluorescence in spots was quantified from images obtained with a confocal microscope. Spot intensities varied widely within branches following labelling at both frequencies, but the distribution was highly skewed towards lower intensities at low frequency stimulation; at high frequency, more spots had stronger fluorescence. Both weak and strongly stained spots were uniformly distributed along the length of terminal branches after low frequency stimulation; however, there was a gradual decline in all spot intensities towards the distal end of branches loaded with dye at high frequency stimulation. Antibody staining for synaptic vesicles was, on average, uniformly distributed along the branches. The increase in number of more strongly FM1-43-labelled spots in terminal branches stimulated at high compared with low frequency suggests that more release sites are active at high rates of nerve stimulation. This "recruitment" of release sites at high frequency stimulation occurs mostly in the proximal half of terminal branches and is not related to the abundance of synaptic vesicles in the terminal.

NMR imaging of changes in vascular morphology due to tumor angiogenesis.

Tumor-sprouted vessels are greater in both number and diameter in comparison to their healthy counterparts. A novel technique based on magnetic susceptibility contrast mechanisms that are sensitive to varying sizes of blood vessels is presented to measure differences between the relaxation rates (1/T2 and 1/T2*) in a rat glioma model and normal cerebral cortex. deltaR2 and deltaR2*, the differences between relaxation rates precontrast and postcontrast agent injection, were measured for an intravascular equilibrium contrast agent (MION) at various echo times. Since deltaR2*/deltaR2 increases as vessel size increases, this ratio can be used as a measure of the average vessel size within an ROI or a voxel. The stability and longevity of the contrast agent within the vasculature were verified (n = 2 trials), and the ratio of deltaR2*/deltaR2 between the tumor and normal cortex was measured to be 1.9+/-0.2 (n = 4, echo time = 20 ms, and susceptibility difference (deltachi) approximately 10(-6)). This ratio compared favorably to a predicted ratio determined using histologically determined vessel sizes and theoretical Monte Carlo modeling results (1.9+/-0.1). Maps of the ratio of deltaR2*/deltaR2 were also made on a pixel-by-pixel basis. These techniques support the hypothesis that susceptibility contrast MRI can provide useful quantitative metrics of in vivo tumor vascular morphology.