Natural killer cell evolution: cellular and molecular studies on Xenopus

The presence of natural killer cells at lower evolutionary levels was investigated in the amphibian Xenopus laevis. Chromium release microcytotoxicity assays revealed that fresh splenocytes from early-thymectomised Xenopus displayed significant spontaneous cytotoxicity against allogeneic B(_3)B(_7) thymic tumor cell targets, unlike those from control Xenopus, suggesting that 'NK-like' activity is greater in thymectomised (T cell-deficient) animals. Addition of Concanavalin A- derived active supernatants to splenocytes from a thymectomised animal caused a significant increase in cytolytic activity, but had no effect on cells from a control animal. This finding of enhanced cytotoxicity was indicative of lymphokine-activated killing in Xenopus, and supported the concept that tumour cell lysis was mediated by NK - like cells. Attempts were made to enrich the splenocytes for natural killer cells through the selective depletion of other lymphocyte subsets, using the techniques of 'panning’ and 'magnetic bead' separation following monoclonal antibody labelling of cells. On comparison of the two techniques, it was found that both were able to deplete a splenocyte culture of B cells to the same extent, but that magnetic sorting produced far superior results for depletion of T cells. Optimum conditions for magnetic sorting were determined, and used to generate 'purified' populations which were tested for their cytolytic activity. Such preliminary investigations suggested that natural killer like activity in Xenopus is likely to be mediated by a 'non-T / non-B' lymphoid subset. Finally, preliminary work was undertaken into the development of 'phage display' technology for the generation of single chain Fy antibody fragments (ultimately against NK cell surface antigens). PGR amplification of the V(_H) and Kappa chains was attempted on RNA extracted (using various methods) from Carboxypeptidase Y-injected-, B(_3)B(_7)-injected-, and unimmunised mice. Following RNA extraction under optimum conditions. Kappa chains were successfully amplified from experimental spleens, but the heavy chains still require more development

How to Improve SBIR Phase 3 Technology Commercialization Effectiveness: A NASA Glenn Internal Assessment

Governmental departments and agencies with responsibilities for implementing the Small Business Innovative Research program under the auspices of the Small Business Administration, are now required to be more accountable for phase 3 performance. At NASA Glenn Research Center, internal, one-on-one interviews were conducted with seven contracting officer technical representatives who have managed one or more SBIR contracts through completion of phase 2. A questionnaire consisting of nineteen questions was formulated and used for the above purpose. This self-assessment produced several comments, conclusions, and recommendations for consideration and potential application

Commercial non-aerospace technology transfer program for the 2000s: Strategic analysis and implementation

This report presents a strategic analysis and implementation plan for NASA's Office of Commercial Programs (OCP), Technology Transfer Division's (TTD), Technology Transfer Program. The main objectives of this study are to: (1) characterize the NASA TTD's environment and past organizational structure; (2) clearly identify current and prospective programmatic efforts; (3) determine an evolutionary view of an organizational structure which could lead to the accomplishment of NASA's future technology transfer aims; and (4) formulate a strategy and plan to improve NASA's (and other federal agencies) ability to transfer technology to the non-aerospace sectors of the U.S. economy. The planning horizon for this study extends through the remainder of the 1990s to the year 2000

The Commtech Methodology: A Demand-Driven Approach to Efficient, Productive, and Measurable Technology Transfer and Commercialization

This paper presents a comprehensive review and assessment of a demonstration technology transfer and commercialization prouram called "CommTech". The pro-ram was conceived and initiated in early to mid-fiscal year 1995, and extended roughly three years into the future. Market research sources were used to initially gather primary technological problems and needs data from non-aerospace companies in three targeted industry sectors: environmental, surface transportation, and bioengineering. Company-supplied information served as input data to activate or start-up an internal, phased matchmaking process. This process was based on technical-level relationship exploration followed by business-level agreement negotiations. and culminated with project management and execution. Space Act Agreements represented near-term outputs. Company product or process commercialization derived from NASA Glenn support and measurable economic effects represented far-term outputs

Structural and functional analysis of pneumococcal histidine triad D from Streptococcus pneumoniae

The pathogenic bacteria Streptococcus pneumoniae is one of the major causes of morbidity and mortality in humans in the world today. A Gram-positive facultative anaerobe, under natural conditions it exists as a commensal bacteria residing in the nasopharynx. Upon invasion of the body, S. pneumoniae can cause a number of diseases, which range in severity from acute otitis-media to pneumonia, septicaemia and meningitis. The main virulence factor of S. pneumoniae has been identified as the polysaccharide capsule, which coats the outside of the cell. S. pneumoniae can be categorised into 92 distinct serotypes based on capsular composition. Current available vaccines utilise a mixture of polysaccharides from the most prevalent capsular serotypes, or capsular polysaccharide conjugated to a carrier protein. Vaccine coverage is therefore serotype specific. Furthermore, vaccine efficiency is lower in those groups most at risk of infection; namely infants, the elderly and the immuno-compromised. As a result investigation is ongoing into a next generation of protein-based vaccine that can provide increased coverage and efficiency. A novel family of proteins termed Pneumococcal Histidine Triad (Pht) proteins were identified from a whole genome antigen-screen as potential candidates for inclusion in a novel protein-based pneumococcal vaccine. Animal models of infection have shown that immunisation with the Pht protein Pneumococcal Histidine Triad D (PhtD) confers protection against invasion of S. pneumoniae. PhtD was cloned, expressed, purified and subjected to crystallisation trials in an attempt to uncover the function of PhtD through determining the protein structure by macromolecular X-ray crystallography, which yielded some rudimentary crystallographic data. Biophysical analysis of PhtD using a variety of techniques including limited proteolysis and circular dichroism revealed that PhtD exclusively bound the divalent-cation Zn2+ and that Zn2+-binding induced a major conformational change in the protein structure, which proved to be a reversible process. A rationalised, targeted analysis of PhtD protein structure by limited proteolysis, Nuclear Magnetic Resonance (NMR), N-terminal sequencing and mass-spectrometry revealed localised, ordered regions of structure within the protein sequence that were highly stable. These identified protein fragments were subsequently cloned, expressed, purified and subjected to crystallisation trials. Due to their smaller and more ordered nature, it was postulated that these PhtD fragments may prove more readily crystallisable than the full-length molecule. Initial crystals have been obtained for these protein fragments and are being optimised to improve crystal size and quality. Evaluation of the PhtD proteolysis products by Western blotting with anti-PhtD antibody has revealed the dominant epitope for the PhtD protein, localised to a 15 kDa region in the C-terminal half of the PhtD protein sequence. This could be a major advancement in development of a protein based vaccine as only the 15 kDa epitope-containing region need be included in order to elicit an antibody reaction. Furthermore, the small size of the protein fragment is highly conducive to structural determination by a variety of methods. This 15 kDa epitope fragment has been cloned into an expression plasmid allowing recombinant protein expression in order to investigate further. Additionally, as training for handling of PhtD X-ray diffraction data, macromolecular X-ray crystallography was attempted with a variety of different proteins from Gram-positive bacteria. Two proteins -a novel cis-trans isomerase PpmA from S. pneumoniae, and the transketolase TktA from Lactobacillus salivarius- were successfully crystallised. Diffraction quality crystals of TktA were grown that produced X-ray diffraction to 2.3Å resolution. The structure of TktA was successfully determined using the molecular replacement method. Diffraction quality crystals of PpmA were grown that show X-ray diffraction to 2.5Å resolution, and optimisation of crystallisation conditions should yield better X-ray diffraction, allowing the structure of PpmA to be determined. The data pertaining to these proteins is also included as part of this thesis

Consumer acceptance of patient-performed mobile teledermoscopy for the early detection of melanoma

Background Mobile teledermoscopy allows consumers to send images of skin lesions to a teledermatologist for remote diagnosis. Currently, technology acceptance of mobile teledermoscopy by people at high risk of melanoma is unknown. Objectives We aimed to determine the acceptance of mobile teledermoscopy by consumers based on perceived usefulness, ease of use, compatibility, attitude/intention, subjective norms, facilitators and trust before use. Consumer satisfaction was explored after use

The Causal Relationship Between Volunteering and Social Cohesion: A Large Scale Analysis of Secondary Longitudinal Data

It is often taken for granted that social cohesion and volunteering are inextricably related. Previous research suggests both that social cohesion creates a conducive environment for volunteering to emerge and that volunteering itself facilitates feelings of social cohesion. Despite this, much of the existing evidence on this relationship is limited to cross-sectional research that precludes any assessment of potential causality. In this paper we present a secondary analysis of two large scale and longitudinal social surveys in the UK: the Understanding Society Household Longitudinal Study and the Beyond Us and Them project. Using data from these surveys we estimate a cross-lagged longitudinal model to assess the causal relationships between social cohesion and volunteering over time. Across both data sources, involving different time intervals, we find significant cross-lagged bi-directional relationships between social cohesion and volunteering. These findings provide much needed empirical support for the proposition that social cohesion and volunteering are causally related over periods of both months and years. Implications for theory and policy are discussed

Heritability of pain catastrophizing and associations with experimental pain outcomes: a twin study

This study used a twin paradigm to examine genetic and environmental contributions to pain catastrophizing and the observed association between pain Catastrophizing and cold-pressor task (CPT) outcomes. Male and female monozygotic (n = 206) and dizygotic twins (n = 194) torn the University of Washington Twin Registry completed a measure of pain catastrophizing and performed a CPT challenge, As expected, pain catastrophizing emerged as a significant predictor of several CPT outcomeS, including cold-pressor Immersion Tolerance, Pain Tolerance, and Delayed Pain Rating. The heritability estimate for pain catastrophizing was found to be 37% with the remaining 63% of variance attributable to unique environmental influence. Additionally, the Observed associations between pain catastrophizing and CPT outcomes were not found attributable to shared genetics or environmental exposure, which suggests a direct relationship between catastrophizing and experimental pain. outcomes. This Study is the first to examine the heritability of pain catastrophizing and potential processes by which pain catastrophizing is related to experimental pain response

Consumer preference and willingness-to-pay for direct-to-consumer mobile-teledermoscopy services in Australia

Objective: To investigate consumer preference and willingness to pay for mobile teledermoscopy services in Australia. Methods: Consumers who were taking part in a randomised controlled trial comparing mobile teledermoscopy and skin self-examination were asked to complete a survey which incorporated a discrete choice experiment (DCE) and a contingent valuation question. Responses were used to determine their willingness to pay for mobile teledermoscopy services in Australia and their overall service preferences. Results: The 199 consumers who responded were 71% female and had a mean age of 42 years (range, 18–73). The DCE results showed that consumers prefer a trained medical professional to be involved in their skin cancer screening. Consumers were willing to pay AUD 41 to change from a general practitioner reviewing their lesions in-person to having a dermatologist reviewing the teledermoscopy images. Additionally, they were willing to pay for services that had shorter waiting times, that reduced the time away from their usual activities, and that have higher accuracy and lower likelihood of unnecessary excision of a skin lesion. When asked directly about their willingness to pay for a teledermoscopy service using a contingent valuation question, the majority (73%) of consumers selected the lowest two value brackets of AUD 1–20 or AUD 21–40. Conclusion: Consumers are willing to pay out of pocket to access services with attributes such as a dermatologist review, improved accuracy, and fewer excisions

Off-Label Biologic Regimens in Psoriasis: A Systematic Review of Efficacy and Safety of Dose Escalation, Reduction, and Interrupted Biologic Therapy

Objectives: While off-label dosing of biologic treatments may be necessary in selected psoriasis patients, no systematic review exists to date that synthesizes the efficacy and safety of these off-label dosing regimens. The aim of this systematic review is to evaluate efficacy and safety of off-label dosing regimens (dose escalation, dose reduction, and interrupted treatment) with etanercept, adalimumab, infliximab, ustekinumab, and alefacept for psoriasis treatment