Development of a high throughput PCR to detect Coxiella burnetii and its application in a diagnostic laboratory over a 7-year period.

Q fever is a worldwide zoonotic infectious disease due to Coxiella burnetii. The clinical presentation may be acute (pneumonia and/or hepatitis) or chronic (most commonly endocarditis). Diagnosis mainly relies on serology and PCR. We therefore developed a quantitative real-time PCR. We first tested blindly its performance on various clinical samples and then, when thoroughly validated, we applied it during a 7-year period for the diagnosis of both acute and persistent C. burnetii infection. Analytical sensitivity (< 10 copies/PCR) was excellent. When tested blindly on 183 samples, the specificity of the PCR was 100% (142/142) and the sensitivity was 71% (29/41). The sensitivity was 88% (7/8) on valvular samples, 69% (20/29) on blood samples and 50% (2/4) on urine samples. This new quantitative PCR was then successfully applied for the diagnosis of acute Q fever and endovascular infection due to C. burnetii, allowing the diagnosis of Q fever in six patients over a 7-year period. During a local small cluster of cases, the PCR was also applied to blood from 1355 blood donors; all were negative confirming the high specificity of this test. In conclusion, we developed a highly specific method with excellent sensitivity, which may be used on sera for the diagnosis of acute Q fever and on various samples such as sera, valvular samples, aortic specimens, bone and liver, for the diagnosis of persistent C. burnetii infection.

Intraspecific genetic variation in arbuscular mycorrhizal fungi and its consequences for molecular biology, ecology, and development of inoculum

It has been known for some time that different arbuscular mycorrhizal fungal (AMF) taxa confer differences in plant growth. Although genetic variation within AMF species has been given less attention, it could potentially be an ecologically important source of variation. Ongoing studies on variability in AMF genes within Glomus intraradices indicate that at least for some genes, such as the BiP gene, sequence variability can be high, even in coding regions. This suggests that genetic variation within an AMF may not be selectively neutral. This clearly needs to be investigated in more detail for other coding regions of AMF genomes. Similarly, studies on AMF population genetics indicate high genetic variation in AMF populations, and a considerable amount of variation seen in phenotypes in the population can be attributed to genetic differences among the fungi. The existence of high within-species genetic variation could have important consequences for how investigations on AMF gene expression and function are conducted. Furthermore, studies of within-species genetic variability and how it affects variation in plant growth will help to identify at what level of precision ecological studies should be conducted to identify AMF in plant roots in the field. A population genetic approach to studying AMF genetic variability can also be useful for inoculum development. By knowing the amount of genetic variability in an AMF population, the maximum and minimum numbers of spores that will contain a given amount of genetic diversity can be estimated. This could be particularly useful for developing inoculum with high adaptability to different environments.

Xanthine oxidase inhibitor allopurinol attenuates the development of diabetic cardiomyopathy.

In this study, we investigated the effect of the xanthine oxidase (XO) inhibitor, allopurinol (ALP), on cardiac dysfunction, oxidative-nitrosative stress, apoptosis, poly(ADP-ribose) polymerase (PARP) activity and fibrosis associated with diabetic cardiomyopathy in mice. Diabetes was induced in C57/BL6 mice by injection of streptozotocin. Control and diabetic animals were treated with ALP or placebo. Left ventricular systolic and diastolic functions were measured by pressure-volume system 10 weeks after established diabetes. Myocardial XO, p22(phox), p40(phox), p47(phox), gp91(phox), iNOS, eNOS mRNA and/or protein levels, ROS and nitrotyrosine (NT) formation, caspase3/7 and PARP activity, chromatin fragmentation and various markers of fibrosis (collagen-1, TGF-beta, CTGF, fibronectin) were measured using molecular biology and biochemistry methods or immunohistochemistry. Diabetes was characterized by increased myocardial, liver and serum XO activity (but not expression), increased myocardial ROS generation, p22(phox), p40(phox), p47(phox), p91(phox) mRNA expression, iNOS (but not eNOS) expression, NT generation, caspase 3/7 and PARP activity/expression, chromatin fragmentation and fibrosis (enhanced accumulation of collagen, TGF-beta, CTGF and fibronectin), and declined systolic and diastolic myocardial performance. ALP attenuated the diabetes-induced increased myocardial, liver and serum XO activity, myocardial ROS, NT generation, iNOS expression, apoptosis, PARP activity and fibrosis, which were accompanied by improved systolic (measured by the evaluation of both load-dependent and independent indices of myocardial contractility) and diastolic performance of the hearts of treated diabetic animals. Thus, XO inhibition with ALP improves type 1 diabetes-induced cardiac dysfunction by decreasing oxidative/nitrosative stress and fibrosis, which may have important clinical implications for the treatment and prevention of diabetic cardiomyopathy and vascular dysfunction.

Pedochronology and development of peat bog in the environmental protection area pau-de-fruta - Diamantina, Brazil

In the region of the Serra do Espinhaço Meridional, peat bog is formed in hydromorphic environments developed in sunken areas on the plain surfaces with vegetation adapted to hydromorphic conditions, favoring the accumulation and preservation of organic matter. This pedoenvironment is developed on the regionally predominant quartzite rocks. Peat bog in the Environmental Protection Area - APA Pau-de-Fruta, located in the watershed of Córrego das Pedras, Diamantina,Brazil, was mapped and three representative profiles were morphologically characterized and sampled for physical, chemical and microbiological analyses. The organic matter was fractionated into fulvic acid (FA), humic acids (HA) and humin (H). Two profiles were sampled to determine the radiocarbon age and δ13C. The structural organization of the three profiles is homogeneous. The first two layers consist of fibric, the two subsequent of hemic and the four deepest of sapric peat, showing that organic matter decomposition advances with depth and that the influence of mineral materials in deeper layers is greater. Physical properties were homogeneous in the profiles, but varied in the sampled layers. Chemical properties were similar in the layers, but the Ca content, sum of bases and base saturation differed between profiles. Contents of H predominated in the more soluble organic matter fractions and were accumulated at a higher rate in the surface and deeper layers, while HA levels were higher in the intermediate and FA in the deeper layers. Microbial activity did not vary among profiles and was highest in the surface layers, decreasing with depth. From the results of radiocarbon dating and isotope analysis, it was inferred that bog formation began about 20 thousand years ago and that the vegetation of the area had not changed significantly since then.