MiR-21-5p but not miR-1-3p expression is modulated by preconditioning in a rat model of myocardial infarction

Molecular Biology Reports - Isoflurane (Iso) preconditioning (PC) is known to be cardioprotective against ischemia/reperfusion (I/R) injury. It was previously shown that microRNA-21-5p (miR-21-5p)...     

Loss of ischemic preconditioning's cardioprotection in aged mouse hearts is associated with reduced gap junctional and mitochondrial levels of connexin 43

Connexin 43 (Cx43) is localized at left ventricular (LV) gap junctions and in cardiomyocyte mitochondria. A genetically induced reduction of Cx43 as well as blockade of mitochondrial Cx43 import abolishes the infarct size (IS) reduction by ischemic preconditioning (IP). With progressing age, Cx43 content in ventricular and atrial tissue homogenates is reduced. We now investigated whether or not 1) the mitochondrial Cx43 content is reduced in aged mice hearts and 2) IS reduction by IP is lost in aged mice hearts in vivo. Confirming previous results, sarcolemmal Cx43 content was reduced in aged (>13 mo) compared with young (<3 mo) C57Bl/6 mice hearts, whereas the expression levels of protein kinase C epsilon and endothelial nitric oxide synthase remained unchanged. Also in mitochondria isolated from aged mice LV myocardium, Western blot analysis indicated a 40% decrease in Cx43 content compared with mitochondria isolated from young mice hearts. In young mice hearts, IP by one cycle of 10 min ischemia and 10 min reperfusion reduced IS (% of area at risk) following 30 min regional ischemia and 120 min reperfusion from 67.7 +/- 3.3 (n = 17) to 34.2 +/- 6.6 (n = 5, P < 0.05). In contrast, IP's cardioprotection was lost in aged mice hearts, since IS in nonpreconditioned (57.5 +/- 4.0, n = 10) and preconditioned hearts (65.4 +/- 6.3, n = 8, P = not significant) was not different. In conclusion, mitochondrial Cx43 content is decreased in aged mouse hearts. The reduced levels of Cx43 may contribute to the age-related loss of cardioprotection by IP.     

Oral scrapie infection modifies the homeostasis of Peyer’s patches’ dendritic cells

In transmitted prion diseases the immune system supports the replication and the propagation of the pathogenic agent (PrPSc). DCs, which are mobile cells present in large numbers within lymph organs, are suspected to carry prions through the lymphoid system and to transfer them towards the peripheral nervous system. In this study, C57Bl/6 mice were orally inoculated with PrPSc (scrapie strain 139A) and sacrificed at the preclinical stages of the disease. Immunolabelled cryosections of Peyer’s patches were analysed by confocal microscopy. Membrane prion protein expression was studied by flow cytometry. In Peyer’s patches (PP), dissected at day one and day 105 after oral exposure to scrapie, we observed an increased population of DCs localised in the follicular-associated epithelium. On day 105, PrPSc was found in the follicles inside the PP of prion-infected mice. A subset of Peyer’s patches DCs, which did not express cellular prion protein on their surface in non-infected mice conditions, was prion-positive in scrapie conditions. Within Peyer’s patches oral scrapie exposure thus induced modifications of the homeostasis of DCs at the preclinical stages of the disease. These results give new arguments in favour of the implication of DCs in prion diseases.     

Integrated conservation and development project life cycles in the Annapurna Conservation Area, Nepal: Is development overpowering conservation?

The merits of integrated conservation and development projects (ICDPs), which aim to provide development incentives to citizens in return for conservation behaviors, have long been debated in the literature. Some of the most common critiques suggest that conservation activities tend to be strongly overpowered by development activities. We studied this assertion through participant observation and archival analysis of five Conservation Area Management Committees (CAMCs) in the Annapurna Conservation Area (ACA), Nepal. Committee activities were categorized as conservation activities (policy development and conservation implementation), development activities (infrastructure, health care, education, economic development, and sanitation), or activities related to institutional strengthening (administrative development and capacity building activities). Greater longevity of each ICDP was associated with greater conservation activity in relation to development activities. Project life cycles progressed from a focus on development activities in their early stages, through a transitional period of institutional strengthening, and toward a longer-term focus that roughly balanced conservation and development activities. Results suggest that the ICDP concept, as practiced in ACA, has been successful at building capacity for and interest in conservation amongst local communities. However, success has come over a period of nearly a decade, suggesting that prior conclusions about ICDP failures may have been based on unrealistic expectations of the time needed to influence behavioral changes in target populations.     

Communities of Archaea and Bacteria in a Subsurface Radioactive Thermal Spring in the Austrian Central Alps, and Evidence of Ammonia-Oxidizing Crenarchaeota

Scanning electron microscopy revealed great morphological diversity in biofilms from several largely unexplored subterranean thermal Alpine springs, which contain radium 226 and radon 222. A culture-independent molecular analysis of microbial communities on rocks and in the water of one spring, the “Franz-Josef-Quelle” in Bad Gastein, Austria, was performed. Four hundred fifteen clones were analyzed. One hundred thirty-two sequences were affiliated with 14 bacterial operational taxonomic units (OTUs) and 283 with four archaeal OTUs. Rarefaction analysis indicated a high diversity of bacterial sequences, while archaeal sequences were less diverse. The majority of the cloned archaeal 16S rRNA gene sequences belonged to the soil-freshwater-subsurface (1.1b) crenarchaeotic group; other representatives belonged to the freshwater-wastewater-soil (1.3b) group, except one clone, which was related to a group of uncultivated Euryarchaeota. These findings support recent reports that Crenarchaeota are not restricted to high-temperature environments. Most of the bacterial sequences were related to the Proteobacteria (α, β, γ, and δ), Bacteroidetes, and Planctomycetes. One OTU was allied with Nitrospina sp. (δ-Proteobacteria) and three others grouped with Nitrospira. Statistical analyses suggested high diversity based on 16S rRNA gene analyses; the rarefaction plot of archaeal clones showed a plateau. Since Crenarchaeota have been implicated recently in the nitrogen cycle, the spring environment was probed for the presence of the ammonia monooxygenase subunit A (amoA) gene. Sequences were obtained which were related to crenarchaeotic amoA genes from marine and soil habitats. The data suggested that nitrification processes are occurring in the subterranean environment and that ammonia may possibly be an energy source for the resident communities.     

Eat your orchid and have it too: a potentially new conservation formula for Chinese epiphytic medicinal orchids

About a quarter of Chinese wild orchid species are used in traditional medicine or as health food supplements. The market demand for some species, such as those in the epiphytic genus Dendrobium, has diminished many wild populations to local extinction or dangerously small numbers. Conservation of these heavily exploited orchids currently relies on a two-pronged approach: establishing nature reserves and encouraging massive commercial cultivation in artificial settings. We argue that these measures are not sufficient to restore or maintain healthy wild populations, and augmentation and reintroduction of these species in natural forests are needed. We argue for an unconventional reintroduction approach, in which populations planted in natural forests are allowed to be sustainably harvested (restoration-friendly cultivation). Because Dendrobium orchids are epiphytic, restoration-friendly cultivation of these species will not be at the expenses of other native plants. In addition, market premiums on wild-collected medicinal plants will generate incentives for farmers who participate in restoration-friendly cultivation to preserve natural forests. With proper policy and oversight, the restoration-friendly cultivation of medicinal Dendrobium orchids will facilitate the conservation of these threatened species, encourage protection of natural forests, and benefit marginalized rural communities. Adding this restoration-friendly cultivation into the current mix of conservation approaches has the potential to turn deeply-entrenched traditional uses of orchids from a conservation challenge to a conservation success.     

In vivo mitochondrial oxygen tension measured by a delayed fluorescence lifetime technique

Mitochondrial oxygen tension (mitoPO₂) is a key parameter for cellular function, which is considered to be affected under various pathophysiological circumstances. Although many techniques for assessing in vivo oxygenation are available, no technique for measuring mitoPO₂ in vivo exists. Here we report in vivo measurement of mitoPO₂ and the recovery of mitoPO₂ histograms in rat liver by a novel optical technique under normal and pathological circumstances. The technique is based on oxygen-dependent quenching of the delayed fluorescence lifetime of protoporphyrin IX. Application of 5-aminolevulinic acid enhanced mitochondrial protoporphyrin IX levels and induced oxygen-dependent delayed fluorescence in various tissues, without affecting mitochondrial respiration. Using fluorescence microscopy, we demonstrate in isolated hepatocytes that the signal is of mitochondrial origin. The delayed fluorescence lifetime was calibrated in isolated hepatocytes and isolated perfused livers. Ultimately, the technique was applied to measure mitoPO₂ in rat liver in vivo. The results demonstrate mitoPO₂ values of ∼30-40 mmHg. mitoPO₂ was highly sensitive to small changes in inspired oxygen concentration around atmospheric oxygen level. Ischemia-reperfusion interventions showed altered mitoPO₂ distribution, which flattened overall compared to baseline conditions. The reported technology is scalable from microscopic to macroscopic applications, and its reliance on an endogenous compound greatly enhances its potential field of applications.     

Transgenic wheat expressing a barley class II chitinase gene has enhanced resistance against Fusarium graminearum

Fusarium head blight (FHB; scab), primarily caused by Fusarium graminearum, is a devastating disease of wheat worldwide. FHB causes yield reductions and contamination of grains with trichothecene mycotoxins such as deoxynivalenol (DON). The genetic variation in existing wheat germplasm pools for FHB resistance is low and may not provide sufficient resistance to develop cultivars through traditional breeding approaches. Thus, genetic engineering provides an additional approach to enhance FHB resistance. The objectives of this study were to develop transgenic wheat expressing a barley class II chitinase and to test the transgenic lines against F. graminearum infection under greenhouse and field conditions. A barley class II chitinase gene was introduced into the spring wheat cultivar, Bobwhite, by biolistic bombardment. Seven transgenic lines were identified that expressed the chitinase transgene and exhibited enhanced Type II resistance in the greenhouse evaluations. These seven transgenic lines were tested under field conditions for percentage FHB severity, percentage visually scabby kernels (VSK), and DON accumulation. Two lines (C8 and C17) that exhibited high chitinase protein levels also showed reduced FHB severity and VSK compared to Bobwhite. One of the lines (C8) also exhibited reduced DON concentration compared with Bobwhite. These results showed that transgenic wheat expressing a barley class II chitinase exhibited enhanced resistance against F. graminearum in greenhouse and field conditions.     

Immunoquantitative real-time PCR for detection and quantification of Staphylococcus aureus enterotoxin B in foods

A real-time immunoquantitative PCR (iqPCR) method for detection of Staphylococcus aureus enterotoxin B (SEB) was developed and evaluated using both pure cultures and foods. The assay consisted of immunocapture of SEB and real-time PCR amplification of the DNA probe linked to the detection antibody. iqPCR was compared to an in-house enzyme-linked immunosorbent assay (ELISA) using the same couple of capture-detection antibodies and to commercial kits for detection of S. aureus enterotoxins (SE). The iqPCR was approximately 1,000 times more sensitive (<10 pg ml(-1)) than the in-house ELISA and had a dynamic range of approximately 10 pg ml(-1) to approximately 30,000 pg ml(-1). iqPCR was not inhibited by any of the foods tested and was able to detect SEB present in these foods. No cross-reactivity with SE other than SEB was observed. Application of iqPCR for detection of SEB in cultures of S. aureus revealed the onset of SEB production after 4 h of incubation at 22, 37, and 42 degrees C, which was in the first half of the exponential growth phase. The total amounts of SEB produced by the two strains tested were larger at 42 degrees C than at 37 degrees C and were strain dependent.     

Relevant Animal Models in Dermatophyte Research

Dermatophytoses are common superficial fungal infections affecting both humans and animals. They are provoked by filamentous fungi called dermatophytes specialized in the degradation of keratinized structures, which allows them to induce skin, hair and nail infections. Despite their high incidence, little investigation has been performed for the understanding of these infections compared to fungal opportunistic infections and most of the studies were based on in vitro experiments. The development of animal models for dermatophyte research is required to evaluate new treatments against dermatophytoses or to increase knowledge about fungal pathogenicity factors or host immune response mechanisms. The guinea pig has been the most often used animal model to evaluate efficacy of antifungal compounds against dermatophytes, while mouse models were preferred to study the immune response generated during the disease. Here, we review the relevant animal models that were developed for dermatophyte research and we discuss the advantages and disadvantages of the selected species, especially guinea pig and mouse.