Claudia Romero

Culture of Mycobacterium avium subspecies paratuberculosis from the blood of patients with Crohn's disease

BACKGROUND Crohns disease, a form of inflammatory bowel disease, resembles some aspects of tuberculosis, leprosy, and paratuberculosis. The role of Mycobacterium avium subspecies paratuberculosis (MAP) in Crohns disease is controversial. METHODS We tested for MAP by PCR and culture in buffy coat preparations from 28 individuals with Crohns disease, nine with ulcerative colitis, and 15 without inflammatory bowel disease. FINDINGS MAP DNA in uncultured buffy coats was identified by PCR in 13 (46%) individuals with Crohns disease, four (45%) with ulcerative colitis, and three (20%) without inflammatory bowel disease. Viable MAP was cultured from the blood of 14 (50%) patients with Crohns disease, two (22%) with ulcerative colitis, and none of the individuals without inflammatory bowel disease. Current use of immunosuppressive medication did not correlate with a positive MAP culture. Sequencing of PCR products from MAP cultures confirmed the presence of the MAP-specific IS900 fragment. Among 11 MAP isolates assessed, we identified nine strains that were not identical. INTERPRETATION We detected viable MAP in peripheral blood in a higher proportion of individuals with Crohns disease than in controls. These data contribute to the evidence that MAP might be a cause of Crohns disease.

Evaluation of surgical tissue from patients with Crohn's disease for the presence of Mycobacterium avium subspecies paratuberculosis DNA by in situ hybridization and nested polymerase chain reaction

&NA; Crohns disease (CD) is a chronic inflammatory bowel disease (IBD) with tissue granuloma and histopathological alteration that resembles aspects in tuberculosis, leprosy, and paratuberculosis. Mycobacterium avium subsp paratuberculosis (MAP) is the causative agent of paratuberculosis, with a suspected role in the etiology of CD. We investigated the presence of MAP DNA in 31 surgical tissue samples from 20 subjects using fluorescence in situ hybridization (FISH) with the aid of confocal scanning laser microscopy and nested polymerase chain reaction (PCR) using the IS900 sequence unique to MAP. MAP DNA was detected by PCR in tissue from 10 of 12 (83%) patients with CD: 7/12 (58%) in inflamed, 6/11 (55%) in noninflamed and in 10 (83%) of either tissue and by FISH in 8 of 12 (67%) patients with CD: 7 of 12 (58%) in inflamed, 4 of 11 (36%) in noninflamed, and in 8(67%) of either tissue. In non‐IBD subjects, MAP DNA was detected in the tissue of only 1 of 6 patients (17%) by PCR and 0 of 6 patients (0%) by FISH. MAP DNA was identified by PCR in inflamed tissue from 2 of 2 patients with ulcerative colitis. The detection of MAP DNA by either technique in tissue from subjects with CD is significant compared with non‐IBD subjects (P < 0.005). Identification of MAP DNA in both inflamed and noninflamed tissue by both techniques suggests that MAP infection in patients with CD may be systemic. The data add more evidence toward a possible association of MAP in the pathogenesis of CD.

Stem responses to damage: the evolutionary ecology of Quercus species in contrasting fire regimes

* The ability of tree stems to recover from damage is critical for tree survival and may explain species distributions across disturbance regimes. Two primary responses to stem damage, decay compartmentalization and wound closure, act in concert to limit decay and pathogen spread. A previous study demonstrated a tradeoff between wound responses that varied with anatomical traits, but its wide taxonomic range made it hard to analyze responses in an evolutionary context. * Here, we tested the stem wound responses of 13 species of Quercus inhabiting three habitats across a gradient of fire intensity. We also quantified anatomical and structural traits and phylogenetic position, in order to assess the relative contributions of ecological adaptation and phylogenetic history in determining traits. * Xylem anatomical traits were phylogenetically constrained, while phloem traits and damage responses varied with habitat. Across habitats, hammock and sandhill species closed bark wounds effectively, whereas scrub species limited the spread of xylem decay. There was a tradeoff between wound closure and decay compartmentalization within the white+live oaks. * The fact that some wound response traits are phylogenetically constrained while others respond to ecological pressures suggests that damage responses integrate mechanisms operating at several levels within plants.

Conservation and Development in Latin America and Southern Africa: Setting the Stage

The articles in this Special Feature stem from a 2010 conference (Bridging Conservation and Development in Latin America and Africa) organized by the University of Florida’s Tropical Conservation Development Program, Center for African Studies, and Center for Latin American Studies. The conference involved researchers and practitioners from Africa and Latin America focused on the complex and evolving relationship between conservation and development. The conference provided bridges between academics and non-academics, conservation and development, and theory and practice. The resulting comparative analyses focus on: empowerment of local institutions; enhanced capacity of local and regional stakeholders through a recognition and validation of local knowledge systems and the creation of knowledge networks; understanding of social and natural landscapes, history, contexts, and their evolution; and the roles of economic and market forces in shaping opportunities for using market-based incentives to promote conservation and development. In this introductory article we propose a conceptual framework based on the six connected pillars of natural resource characteristics, interactions of social actors, governance and participation, politics, information exchange, and economic issues that support spaces for both conflicts and synergies between conservation and development goals. Our goal is to foster informed dialogue and social learning to promote sustainability.

Building interdisciplinary frameworks: The importance of institutions, scale, and politics

Diaz et al. (1) proposed an “interdisciplinary framework for the analysis of relationships between functional diversity, ecosystem services, and human actions.” Their framework addresses the linkages between land uses and ecosystem service (ES) provision to inform decisions by relevant parties. We welcome the development and practical application of tools for analyzing the complexity of social-ecological systems (SESs), but there are fundamental gaps in the oversimplified framework of Diaz et al. (1). These flaws obscure critical aspects of the functioning of SESs, preclude their improved understanding, and thereby undermine the goal of fruitful scientific analysis.

Opportunity costs of carbon sequestration in a forest concession in central Africa

BackgroundA large proportion of the tropical rain forests of central Africa undergo periodic selective logging for timber harvesting. The REDD+ mechanism could promote less intensive logging if revenue from the additional carbon stored in the forest compensates financially for the reduced timber yield.ResultsCarbon stocks, and timber yields, and their associated values, were predicted at the scale of a forest concession in Gabon over a project scenario of 40 yr with reduced logging intensity. Considering that the timber contribution margin (i.e. the selling price of timber minus its production costs) varies between 10 and US

Cellular Infiltration and Cytokine Expression Correlate with Fistulizing State in Crohn's Disease

40 m −3, the minimum price of carbon that enables carbon revenues to compensate forgone timber benefits ranges between US

Improving credibility and transparency of conservation impact evaluations through the partial identification approach

4.4 and US

Functional Dysregulation of PBMC and PMN in Crohn's Disease

25.9/tCO 2 depending on the management scenario implemented.ConclusionsWhere multiple suppliers of emission reductions compete in a REDD+ carbon market, tropical timber companies are likely to change their management practices only if very favourable conditions are met, namely if the timber contribution margin remains low enough and if alternative management practices and associated incentives are appropriately chosen.

Identification of Mycobacterium avium ss. paratuberculosis in Crohn's tissue

ABSTRACT The purpose of this study was to determine the degree of infiltration of different cell subpopulations (tissue dendritic macrophages, T-helper cells, cytotoxic T lymphocytes, monocytes, neutrophils, and B cells) and the expression of the cytokines interleukin-12 (IL-12) and tumor necrosis factor alpha (TNF-α) in inflamed and noninflamed resected tissues from Crohns disease (CD) and non-CD patients. Twenty-one resected full-thickness intestinal tissue specimens representing 13 subjects (8 CD and 5 non-CD patients) were included in this study. Sections of 20 μm in thickness were cut and then stained using immunohistochemistry. The sections were analyzed using confocal laser scanning microscopy (CLSM). Patterns of staining for inflamed CD and noninflamed CD tissues versus non-CD tissues demonstrated significant differences in the macrophage and T-helper subpopulations. Surprisingly, the T-helper subset was decreased significantly in the inflamed CD sections compared to the noninflamed CD and non-CD sections. The staining patterns also suggested differences in the expression of both IL-12 and TNF-α between the groups, with cytokine overexpression directly relating to the fistulizing state in CD patients. Cytokine expression is upregulated in chronic CD patients; therefore, the degree of inflammation and tissue damage in CD is dependent on the expression of specific cytokines within the tissue. Differentiation of cell subpopulations may be important for establishing a direct relationship with each state of CD (inflammatory, stricturing, and fistulizing states).