11,426 research outputs found

    Multiscreen serum analysis of highly sensitized renal dialysis patients for antibodies toward public and private class I HLA determinants: Implications for computer-predicted acceptable and unacceptable donor mismatches in kidney transplantation

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    A multiscreen serum analysis program has been developed that permits a determination of antibody specificity for the vast majority of highly sensitized patients awaiting transplantation. This program is based on a 2 x 2 table analysis of correlations between serum reactivity with an HLA-typed cell panel and incorporates two modifications. One implements the concept of public HLA determinants based on the serologic crossreactivity among class I HLA antigens. The other modification derives from the premise that most highly sensitized patients maintain the same PRA and antibody profiles over many months and even years. Monthly screening results for patients with persistent PRA values can therefore be combined for analysis. For 132 of 150 highly sensitized patients with >50% PRA, this multiscreen serum analysis program yielded information about antibody specificity toward public and private class IHLA determinants. The vast majority of patients (108 of 112) with PRA values between 50 and 89% showed antibody specificity generally toward one, two, or three public markers and/or the more common private HLA-A, B antigens. For 24 of 38 patients with >90% PRA, it was possible to define one or few HLA-specific antibodies. The primary objective of the multiscreen program was to develop an algorithm about computer-predicted acceptable and unacceptable donor HLA-A, B antigens for patients with preformed antibodies. A retrospective analysis of kidney transplants into 89 highly sensitized patients has demonstrated that allografts with unacceptable HLA-A, B mismatches had significantly lower actuarial survival rates than those with acceptable mismatches (P = 0.01). This was shown for both groups of 32 primary transplants (44% vs. 67% after 1 year) and 60 retransplants (50% vs. 68%). Also, serum creatinine levels were significantly higher in patients with unacceptable class I mismatches (3.0 vs. 8.4 mg% [P = 0.007] after 2 weeks; 3.9 vs. 9.1 mg% [P = 0.014] after 4 weeks). Histopathologic analysis of allograft tissue specimens from 47 transplant recipients revealed a significantly higher incidence of humoral rejection (P = 0.02), but not cellular rejection, in the unacceptable mismatch group. These results suggest that the multiscreen program can establish which donor HLA-A, B mismatches must be avoided in kidney transplantation for most highly sensitized patients. For 18 of 150 high PRA renal dialysis patients, the multiscreen program could not define HLA-specific antibody. Most patients had >90% PRA, and many of their sera appeared to contain IgM type nonspecific lympho- cytotoxins that could be inactivated by dithioerythreitol (DTE). Preliminary studies have shown that this treatment enabled the detection of HLA-specific antibodies upon subsequent screening on many occasions. These data suggest that non-HLA specific reactivity revealed by multiscreen analysis can often be removed by DTE treatment. Multiscreen analysis offers an attractive approach to regional organ-sharing programs for highly sensitized renal transplant candidates. It enables the development of an efficient strategy for donor selection based on the computer assignment of acceptable HLA-A, B mismatches for each patient. © 1990 by Williams and Wilkins

    Understanding fans' responses to the sponsor of a rival team

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    Research Question What factors determine fans’ responses to the sponsor of a rival team? To what extent does higher in-group fan identification, more positive prior attitudes to the sponsor, and a more congruent fit between the sponsor and club, cause denigration or mitigate negative outcomes for the sponsor? Research Methods 300 questionnaires were collected from fans of English Premier League (EPL) football teams Newcastle United and Sunderland allowed us to test our model of sponsorship responses. Structural equation modelling (SEM) was used to evaluate each hypothesis. Results and Findings Brands will gain greater benefits from sponsorships deemed to be congruent with the rival team and where a higher pre-sponsorship attitude exists. More highly identified fans tend to pay greater attention to the sponsor of their rival team. We find that schadenfreude is a better predictor of affective and behavioural responses than fan identification, despite its popularity in recent research involving rival fans. Implications Brand managers concerned about the size and scope of out-groups can employ our findings to more effectively configure sponsorship activities

    Searching (the) FIRST radio arcs near ACO clusters

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    Gravitational lensing (GL) of distant radio sources by galaxy clusters should produce radio arc(let)s. We extracted radio sources from the FIRST survey near Abell cluster cores and found their radio position angles to be uniformly distributed with respect to the cluster centres. This result holds even when we restrict the sample to the richest or most centrally condensed clusters, and to sources with high S/N and large axial ratio. Our failure to detect GL with statistical methods may be due to poor cluster centre positions. We did not find convincing candidates for arcs either. Our result agrees with theoretical estimates predicting that surveys much deeper than FIRST are required to detect the effect. This is in apparent conflict with the detection of such an effect claimed by Bagchi & Kapahi (1995).Comment: 6 pages; 8 figures and 1 style file are included; to appear in Proc. "Observational Cosmology with the New Radio Surveys", eds. M. Bremer, N. Jackson & I. Perez-Fournon, Kluwer Acad. Pres

    Can virtual nature improve patient experiences and memories of dental treatment? A study protocol for a randomized controlled trial

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    Background Dental anxiety and anxiety-related avoidance of dental care create significant problems for patients and the dental profession. Distraction interventions are used in daily medical practice to help patients cope with unpleasant procedures. There is evidence that exposure to natural scenery is beneficial for patients and that the use of virtual reality (VR) distraction is more effective than other distraction interventions, such as watching television. The main aim of this randomized controlled trial is to determine whether the use of VR during dental treatment can improve the overall dental experience and recollections of treatment for patients, breaking the negative cycle of memories of anxiety leading to further anxiety, and avoidance of future dental appointments. Additionally, the aim is to test whether VR benefits dental patients with all levels of dental anxiety or whether it could be especially beneficial for patients suffering from higher levels of dental anxiety. The third aim is to test whether the content of the VR distraction can make a difference for its effectiveness by comparing two types of virtual environments, a natural environment and an urban environment. Methods/design The effectiveness of VR distraction will be examined in patients 18 years or older who are scheduled to undergo dental treatment for fillings and/or extractions, with a maximum length of 30 minutes. Patients will be randomly allocated into one of three groups. The first group will be exposed to a VR of a natural environment. The second group will be exposed to a VR of an urban environment. A third group consists of patients who receive standard care (control group). Primary outcomes relate to patients’ memories of the dental treatment one week after treatment: (a) remembered pain, (b) intrusive thoughts and (c) vividness of memories. Other measures of interest are the dental experience, the treatment experience and the VR experience. Trial registration Current Controlled Trials ISRCTN4144280

    Next Generation Sequencing Assay for Detection of Circulating HPV DNA (cHPV-DNA) in Patients Undergoing Radical (Chemo)Radiotherapy in Anal Squamous Cell Carcinoma (ASCC).

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    Background: Following chemo-radiotherapy (CRT) for human papilloma virus positive (HPV+) anal squamous cell carcinoma (ASCC), detection of residual/recurrent disease is challenging. Patients frequently undergo unnecessary repeated biopsies for abnormal MRI/clinical findings. In a pilot study we assessed the role of circulating HPV-DNA in identifying "true" residual disease. Methods: We prospectively collected plasma samples at baseline (n = 21) and 12 weeks post-CRT (n = 17). Circulating HPV-DNA (cHPV DNA) was measured using a novel next generation sequencing (NGS) assay, panHPV-detect, comprising of two primer pools covering distinct regions of eight high-risk HPV genomes (16, 18, 31, 33, 35, 45, 52, and 58) to detect circulating HPV-DNA (cHPV DNA). cHPV-DNA levels post-CRT were correlated to disease response. Results: In pre-CRT samples, panHPV-detect demonstrated 100% sensitivity and specificity for HPV associated ASCC. PanHPV-detect was able to demonstrate cHPV-DNA in 100% (9/9) patients with T1/T2N0 cancers. cHPV-DNA was detectable 12 weeks post CRT in just 2/17 patients, both of whom relapsed. 1/16 patients who had a clinical complete response (CR) at 3 months post-CRT but relapsed at 9 months and 1/1 patient with a partial response (PR). PanHPV-detect demonstrated 100% sensitivity and specificity in predicting response to CRT. Conclusion: We demonstrate that panHPV-detect, an NSG assay is a highly sensitive and specific test for the identification of cHPV-DNA in plasma at diagnosis. cHPV-DNA post-treatment may predict clinical response to CRT

    Accessibility of antiretroviral therapy in Ghana: Convenience of access

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    The convenience of accessing antiretroviral therapy (ART) is important for initial access to care and subsequent adherence to ART. We conducted a qualitative study of people living with HIV/AIDS (PLWHA) and ART healthcare providers in Ghana in 2005. The objective of this study was to explore the participants’ perceived convenience of accessing ART by PLWHA in Ghana. The convenience of accessing ART was evaluated from the reported travel and waiting times to receive care, the availability, orotherwise, of special considerations, with respect to the waiting time to receive care, for those PLWHA who were in active employment in the formal sector, the frequency of clinic visits before and after initiating ART, and whether the PLWHA saw the same or different providers at each clinic visit (continuity of care). This qualitative study used in-depth interviews based on Yin’s case-study research design to collect data from 20 PLWHA and 24 ART healthcare providers as study participants. . Reported travel time to receive ART services ranged from 2 to 12 h for 30% of the PLWHA.. Waiting time to receive care was from 4 to 9 h. . While known government workers, such as teachers, were attended to earlier in some of the centres, this was not a consistent practice in all the four ART centres studied. . The PLWHA corroborated the providers’ description of the procedure for initiating and monitoring ART in Ghana. . PLWHA did not see the same provider every time, but they were assured that this did not compromise the continuity of their care. Our study suggests that convenience of accessing ART is important to both PLWHA and ART healthcare providers, but the participants alluded to other factors, including open provider–patient communication, which might explain the PLWHA’sunderstanding of the constraints under which they were receiving care. The current nation-wide coverage of the ART programme in Ghana, however, calls for the replication of this study to identify possible perception changes over time that may need attention. Our study findings can inform interventions to promote access to ART, especially in Africa
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