27 research outputs found
Human Bone Marrow Mesenchymal Stem Cells Display Anti-Cancer Activity in SCID Mice Bearing Disseminated Non-Hodgkin's Lymphoma Xenografts
Abstract
BACKGROUND:
Although multimodality treatment can induce high rate of remission in many subtypes of non-Hodgkin's lymphoma (NHL), significant proportions of patients relapse with incurable disease. The effect of human bone marrow (BM) mesenchymal stem cells (MSC) on tumor cell growth is controversial, and no specific information is available on the effect of BM-MSC on NHL.
METHODOLOGY/PRINCIPAL FINDINGS:
The effect of BM-MSC was analyzed in two in vivo models of disseminated non-Hodgkin's lymphomas with an indolent (EBV(-) Burkitt-type BJAB, median survival = 46 days) and an aggressive (EBV(+) B lymphoblastoid SKW6.4, median survival = 27 days) behavior in nude-SCID mice. Intra-peritoneal (i.p.) injection of MSC (4 days after i.p. injection of lymphoma cells) significantly increased the overall survival at an optimal MSC:lymphoma ratio of 1:10 in both xenograft models (BJAB+MSC, median survival = 58.5 days; SKW6.4+MSC, median survival = 40 days). Upon MSC injection, i.p. tumor masses developed more slowly and, at the histopathological observation, exhibited a massive stromal infiltration coupled to extensive intra-tumor necrosis. In in vitro experiments, we found that: i) MSC/lymphoma co-cultures modestly affected lymphoma cell survival and were characterized by increased release of pro-angiogenic cytokines with respect to the MSC, or lymphoma, cultures; ii) MSC induce the migration of endothelial cells in transwell assays, but promoted endothelial cell apoptosis in direct MSC/endothelial cell co-cultures.
CONCLUSIONS/SIGNIFICANCE:
Our data demonstrate that BM-MSC exhibit anti-lymphoma activity in two distinct xenograft SCID mouse models of disseminated NHL
Crop pests and predators exhibit inconsistent responses to surrounding landscape composition
The idea that noncrop habitat enhances pest control and represents a win–win opportunity to conserve biodiversity and bolster yields has emerged as an agroecological paradigm. However, while noncrop habitat in landscapes surrounding farms sometimes benefits pest predators, natural enemy responses remain heterogeneous across studies and effects on pests are inconclusive. The observed heterogeneity in species responses to noncrop habitat may be biological in origin or could result from variation in how habitat and biocontrol are measured. Here, we use a pest-control database encompassing 132 studies and 6,759 sites worldwide to model natural enemy and pest abundances, predation rates, and crop damage as a function of landscape composition. Our results showed that although landscape composition explained significant variation within studies, pest and enemy abundances, predation rates, crop damage, and yields each exhibited different responses across studies, sometimes increasing and sometimes decreasing in landscapes with more noncrop habitat but overall showing no consistent trend. Thus, models that used landscape-composition variables to predict pest-control dynamics demonstrated little potential to explain variation across studies, though prediction did improve when comparing studies with similar crop and landscape features. Overall, our work shows that surrounding noncrop habitat does not consistently improve pest management, meaning habitat conservation may bolster production in some systems and depress yields in others. Future efforts to develop tools that inform farmers when habitat conservation truly represents a win–win would benefit from increased understanding of how landscape effects are modulated by local farm management and the biology of pests and their enemies
Confronting the Yugoslav Controversies: A Scholars\u27 Initiative (Second Edition)
It has been two decades since Yugoslavia fell apart. The brutal conflicts that followed its dissolution are over, but the legacy of the tragedy continues to unsettle the region. Reconciliation is a long and difficult process that necessitates a willingness to work together openly and objectively in confronting the past. Over the past decade the Scholars’ Initiative assembled an international consortium of historians, social scientists, and jurists to examine the salient controversies that still divide the peoples of former Yugoslavia. The broadly conceived synthesis will assist scholars, public officials, and the people they represent both in acknowledging inconvenient facts and in discrediting widely held myths that inform popular attitudes and the electoral success of nationalist politicians who profit from them.https://docs.lib.purdue.edu/purduepress_ebooks/1027/thumbnail.jp
Reformas e reformismo: "democracia progressiva" e políticas sociais (ou "para uma teoria política da reforma sanitária")
Na introdução deste artigo, o autor parte de uma preocupação com o debate atual em torno do processo de tentativa de inovação política setorial que vem sendo designado entre nós pela expressão "Reforma Sanitária". Chama a atenção para os diferentes sentidos em que, a seu ver, esta expressão tem sido utilizada no Brasil E se dispõe a deter-se, particularmente, em um destes sentidos: o que se aproxima da formulação italiana de mesmo nome (a "Riforma Sanitária"). Esta discussão o leva, no corpo do artigo propriamente dito, a tratar, centralmente, da relação entre as características assumidas pela ordenação política liberal contemporânea e a estratégia gramsci-togliattiana de transição no socialismo, no que tange ao tema das chamadas "Políticas Públicas" e, mais particularmente, das "Políticas Sociais". O artigo termina com um esboço inicial de um projeto de investigação comparativa nesta área.<br>In the introduction, the author discusses the current debate on the "Reforma Sanitária"; a proposal to innovate health policy. The author draws attention to the different meanings that can be attributed, in his opinion, to the use of this term in Brazil. He focusses particularly on the meaning closer to that of the Italian proposal of the same name ("Riforma Sanitaria"). The discussion leads the author to question the relationship between the characteristics of the contemporary political liberal organization and the Gramsci-Togliattian strategy of the transition in socialism, within the field of "Public Policies" and more specifically ''Social Policies". The article ends with a preliminary outline a comparative investigation in this field