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1.
OBJECTIVE: To answer the question whether positive selection of (pre)schizophrenic Surinams in Surinam before emigration to the Netherlands can explain the high admission rates for schizophrenia of Surinams in the Netherlands. DESIGN: Retrospective research. SETTING: 's Lands Psychiatrisch Ziekenhuis (National Psychiatric Hospital) Paramaribo, Surinam (LPZ). METHOD: The Netherlands Central Bureau of Statistics in Voorburg and the Central Registry Office in Paramaribo provided data on emigration to the Netherlands of the Surinam population and on remigration. Files of (pre)schizophrenic patients were selected from the records of LPZ. Subsequently, these patients were traced and their pattern of migration was studied. Using the chi 2 test the significance of observed differences was assessed. RESULTS: Surinam (pre)schizophrenic patients did not emigrate more frequently to the Netherlands (6.3%) compared with the Surinam population in general (9.6%) and they remigrated more frequently to Surinam than the Surinams in general. CONCLUSION: The positive selection hypothesis must be rejected.  相似文献   
2.
Previous xenogeneic immunization experiments in rhesus macaques with simian immunodeficiency virus (SIV) grown in human CD4(+) T cells consistently elicited protection from challenge with live SIV. However, the mechanism of protection has not been established. We present evidence that xenogeneic immunization induced significant CD8 suppressor factor, RANTES (regulated upon activation, normal T cell expressed and secreted), macrophage inflammatory protein (MIP) 1alpha, and MIP-1beta (P < 0.001 - P < 0.02). The concentrations of these increased significantly in protected as compared with infected macaques (P < 0.001). Xenogeneic stimulation in vitro also up-regulated CD8 suppressor factors (SF; P < 0.001) and the beta chemokines which were neutralized by antibodies to the 3 beta chemokines. Recombinant human RANTES, MIP-1alpha and MIP-1beta which bind to simian CCR5, suppressed SIV replication in a dose-dependent manner, with RANTES being more effective than the other two chemokines. The results suggest that immunization with SIV grown in human CD4(+) T cells induces CD8-suppressor factor, RANTES, MIP-1alpha and MIP-1beta which may block CCR5 receptors and prevent the virus from binding and fusion to CD4(+) cells.  相似文献   
3.
We present the case of a 69 yr old, white male, suffering from diffuse interstitial lung disease, finally diagnosed as paracoccidioidomycosis or South American blastomycosis. During the course of his disease, antineutrophil cytoplasmic antibodies (c-ANCAs) became positive, suggesting the possibility of a Wegener's granulomatosis. Transbronchial biopsies and a video-assisted thoracoscopic lung biopsy revealed only the pulmonary yeast infection, without other co-existing pathology. During treatment with itraconazole, the patient improved clinically and functionally, and c-ANCAs became negative. Serological monitoring confirmed the diagnosis. To our knowledge, this is the first report describing positive c-ANCAs in a patient with paracoccidioidomycosis. It re-emphasizes the fact that cautious interpretation of c-ANCAs in patients without convincing clinical signs or pathological evidence of a granulomatous vasculitis is absolutely necessary. In this era of increased mobility, a thorough medical history, including documentation of travel, remains an inexpensive tool in making a diagnosis and is still the cornerstone of good medical practice.  相似文献   
4.
In the present study the contribution of rat liver endothelial cells (EC) and Kupffer cells (KC) in the clearance of human (hu) C1q in rats was investigated. In untreated rats and rats depleted from KC the clearance kinetics and the tissue distribution of hu C1q were measured. In untreated rats, the clearance of hu C1q occurred in a monophasic manner with a half-life of 66 +/- 26.7 min. The clearance of hu C1q in KC-depleted rats was delayed significantly (p < 0.001) and occurred with a half-life of 217 +/- 78.8 min. Fifteen min after injection, 11 +/- 3.5% of hu C1q was found in the liver of untreated rats and 8 +/- 1.4% was found in the liver of KC-depleted rats. The percentage non-trichloroacetic acid precipitable activity in the circulation, as a measure for degradation of C1q, reached a level of 11.6 +/- 5.6% at 240 min in untreated rats compared with 4.6 +/- 5.8% in KC-depleted rats. Double immunofluorescence staining 5 min after administration of C1q in untreated rats, revealed that C1q was associated with KC and EC in the liver. Fifteen minutes after i.v. injection of hu C1q, there was an uptake of C1q in the hepatocytes. In KC-depleted rats, 5 min after administration of hu C1q, C1q was bound to the EC. Fifteen minutes after injection, C1q was also found in the hepatocytes. Electron microscopical studies revealed that C1q binds to EC, and that it is internalized in the hepatocytes and KC. The clearance of hu C1q in untreated rats was inhibited by preadministration of high concentrations of bovine C1q. These data show that rats depleted from KC are able to bind, internalize and degrade C1q, and that EC may play a role in the handling of C1q and C1q bound to immune complexes.  相似文献   
5.
BACKGROUND: The kinetics of panel reactive antibodies (PRA) and incidence of antibodies directed against human leukocyte antigen (HLA) class II were studied in patients who received a cryopreserved cardiac valve allograft. METHODS: A complement-dependent microlymphocytotoxicity test was used to determine the percentage of panel reactive antibodies. Anti-HLA class II antibodies were measured by two-color fluorescence assays. RESULTS: The panel reactive antibodies became positive in 25 (78%) of 32 recipients between 1 and 16 months after implantation. Antibodies against HLA class II antigens were detected in 11 (37%) of 30 patients. In 9 (82%) of 11 cases these antibodies were donor specific. The induction of antibodies against donor HLA class II antigens suggests that intact HLA class II antigens are expressed by viable cells within the graft. Dithiothreitol analysis showed that the antibodies were of the immunoglobulin G type. Apparently, the HLA class II antigens are expressed in an immunogenic way, as activation of specific T-helper cells is essential for the switch from immunoglobulin M to immunoglobulin G antibodies. CONCLUSIONS: Allogeneic valve transplantation is associated with the production of donor-specific anti-HLA class I and II antibodies that could contribute to graft failure. This possibly detrimental effect might be prevented by cross matching in sensitized patients.  相似文献   
6.
Understanding complex processes of landscape change is crucial to guide the development of future landscapes and land resources. Through Fuzzy Cognitive Mapping, we studied the processes of landscape change of six different environmental zones in Europe. Results show that landscapes are complex systems, with many interactions. Except for one, all regions show a strong decline in landscape quality. Dominant drivers are EU policy and the global economy, sometimes in conjunction with environmental drivers or the governance system. The process of change differs for all cases, through urbanisation or land abandonment in some cases, and agricultural intensification in others. The (un)intended effects of policies are difficult to predict. Although some EU Policies directly improve landscape quality, their indirect effects as well as other EU policies outweigh this positive influence and jointly result in a decrease of landscape quality. To counter these negative side effects, targeted landscape policies are urgently needed.  相似文献   
7.
User Modeling and User-Adapted Interaction -  相似文献   
8.
In this article, we explore processes of innovation – which are inherently uncertain – from a complexity perspective, in which they are understood as new patterns of experiences as they emerge in human conversational interaction. We reflect on local interactions between people involved in emerging processes of innovation, with a particular emphasis on the improvisational nature of interaction. Through an abductive approach, by iterating actual experiences and our understanding of them, we show that such processes are collective efforts that take place as informal, highly improvised conversations — happening ‘below the radar’ — which may unpredictably offer windows of opportunity to enable change. We show that innovation often emerges as ‘shadow themes’, experienced as subversive by those involved in the moments of interaction. While these themes are embedded in informal conversations and processes, they can be induced by invitations – conscious or unconscious moves that encourage those involved to make spontaneous moves together in a mutually improvised context. Our experience shows that the emergence of shadow themes can have a long‐term impact on the organization and the people involved, and that managers may be ‘in charge but not in control’ of such innovation processes.  相似文献   
9.
This paper explores how an open approach to new venture creation – purposefully managing knowledge flows across the venture's organizational boundary – can be beneficial for start‐up entrepreneurs. Our inductive case study, of both failure and success, identifies the key attributes of this open approach and how they affect start‐ups' short‐term survival. We find that ecosystem collaboration, user involvement and an open environment directly influence new venture survival, and that their effects were moderated by the entrepreneurs' open mindset. These findings carry a number of implications for entrepreneurship and innovation research and practice, providing some attention points for researchers, entrepreneurs, investors and policy makers interested in developing successful new ventures.  相似文献   
10.
Abstract

This paper provides an overview of the main perspectives and themes emerging in research on open innovation (OI). The paper is the result of a collaborative process among several OI scholars – having a common basis in the recurrent Professional Development Workshop on ‘Researching Open Innovation’ at the Annual Meeting of the Academy of Management. In this paper, we present opportunities for future research on OI, organised at different levels of analysis. We discuss some of the contingencies at these different levels, and argue that future research needs to study OI – originally an organisational-level phenomenon – across multiple levels of analysis. While our integrative framework allows comparing, contrasting and integrating various perspectives at different levels of analysis, further theorising will be needed to advance OI research. On this basis, we propose some new research categories as well as questions for future research – particularly those that span across research domains that have so far developed in isolation.  相似文献   
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