Davide Sisti

A comprehensive meta-analysis of the risk of suicide in eating disorders

Preti A, Rocchi MBL, Sisti D, Camboni MV, Miotto P. A comprehensive meta‐analysis of the risk of suicide in eating disorders.

Phylogenetic Characterization and In Situ Detection of a Cytophaga-Flexibacter-Bacteroides Phylogroup Bacterium in Tuber borchii Vittad. Ectomycorrhizal Mycelium

ABSTRACT Mycorrhizal ascomycetous fungi are obligate ectosymbionts that colonize the roots of gymnosperms and angiosperms. In this paper we describe a straightforward approach in which a combination of morphological and molecular methods was used to survey the presence of potentially endo- and epiphytic bacteria associated with the ascomycetous ectomycorrhizal fungus Tuber borchii Vittad. Universal eubacterial primers specific for the 5′ and 3′ ends of the 16S rRNA gene (16S rDNA) were used for PCR amplification, direct sequencing, and phylogenetic analyses. The 16S rDNA was amplified directly from four pure cultures of T. borchii Vittad. mycelium. A nearly full-length sequence of the gene coding for the prokaryotic small-subunit rRNA was obtained from each T. borchii mycelium studied. The 16S rDNA sequences were almost identical (98 to 99% similarity), and phylogenetic analysis placed them in a single unique rRNA branch belonging to theCytophaga-Flexibacter-Bacteroides (CFB) phylogroup which had not been described previously. In situ detection of the CFB bacterium in the hyphal tissue of the fungus T. borchii was carried out by using 16S rRNA-targeted oligonucleotide probes for the eubacterial domain and the Cytophaga-Flexibacter phylum, as well as a probe specifically designed for the detection of this mycelium-associated bacterium. Fluorescent in situ hybridization showed that all three of the probes used bound to the mycelium tissue. This study provides the first direct visual evidence of a not-yet-cultured CFB bacterium associated with a mycorrhizal fungus of the genusTuber.

Anatomical and morphological characterization of mycorrhizas of five strains of Tuber borchii Vittad

Abstract Tilia platyphyllos Scop. plantlets were inoculated in vitro with five Tuber borchii Vittad. strains (1BO, 17BO, 43BO, 71BO and 10RA) to test their intraspecific variability. The ability of the strains to form mycorrhizas varied, with the mean degree of ectomycorrhizal infection ranging from 50.6% (for 1BO) to 82.1% (for 10RA). The anatomical/morphological characteristics of the resulting mycorrhizas were determined. Although the morphological features of the mycorrhizas and the characteristics of the cystidia were similar for all strains tested, differences were found in the anatomical features of the mantle. The form of the mantle cells was examined in the surface and inner layers (6 and 12 μm deep, respectively) by both conventional and confocal microscopy. These cells were polygonal in 1BO, and 71BO, epidermoid in 43BO and intermediate in 17BO and 10RA. The structure of the mantle also varied and thus provided little information with which to identify T. borchii mycorrhizas.

Differential gene expression during pre-symbiotic interaction between Tuber borchii Vittad. and Tilia americana L.

Ectomycorrhizal formation is a highly regulated process involving the molecular reorganization of both partners during symbiosis. An analogous molecular process also occurs during the pre-symbiotic phase, when the partners exchange molecular signals in order to position and prepare both organisms for the establishment of symbiosis. To gain insight into genetic reorganization in Tuber borchii during its interaction with its symbiotic partner Tilia americana, we set up a culture system in which the mycelium interacts with the plant, even though there is no actual physical contact between the two organisms. The selected strategies, suppressive subtractive hybridisation and reverse Northern blots, allowed us to identify, for the first time, 58 cDNA clones differentially expressed in the pre-symbiotic phase. Sequence analysis of the expressed sequence tags showed that the expressed genes are involved in several biochemical pathways: secretion and apical growth, cellular detoxification, general metabolism and both mutualistic and symbiotic features.

Precision performance at low levels and 99th percentile concentration of the Access AccuTnl assay on two different platforms.

Abstract Background: Cardiac troponins currently represent the preferred biomarkers for the detection of myocardial necrosis. The objective of the present study was to compare the performance of the Access® AccuTnI® assay (Beckman Coulter) measured on two different platforms, the UniCel® DxI 800 and the Access® 2 (Beckman Coulter). In particular, the serum cardiac troponin I (cTnI) concentration corresponding to 10% coefficient of variation (CV), the cTnI assay minimum detectable concentration (MDC), and the serum cTnI 99th percentile in healthy subjects were calculated. Methods: The Access® AccuTnI® is a paramagnetic particle chemiluminescent immunoassay. Imprecision profiles were determined according to the Clinical and Laboratory Standards Institute EP5-A protocol using serum pools. The MDC was calculated as mean+3 SD of 20 determinations of the zero calibrator during one run. The 99th percentile was determined analyzing serum samples from 679 healthy blood donors (523 males, 156 females; 18–71 years old). Results: cTnI concentrations are given in μg/L. 10% CV values (95% confidence interval, CI) were 0.0577 (0.0467–0.0750) (UniCel® DxI 800) and 0.0486 (0.0255–0.0596) (Access® 2). MDC values were 0.011 (UniCel® DxI 800) and 0.012 (Access® 2). The 99th percentile (95% CI) value was 0.0340 (0.0298–0.0410). Conclusions: Our data confirm the reliability of the evaluated cTnI assay and demonstrate the comparability of the cTnI values between the platforms studied. Clin Chem Lab Med 2009;47:367–71.

The expression profile of the Tuber borchii nitrite reductase suggests its positive contribution to host plant nitrogen nutrition

Ectomycorrhizal symbiosis is a ubiquitous association between plant roots and numerous fungal species. One of the main aspects of the ectomycorrhizal association are the regulation mechanisms of fungal genes involved in nitrogen acquisition. We report on the genomic organisation of the nitrate gene cluster and functional regulation of tbnir1, the nitrite reductase gene of the ectomycorrhizal ascomycete Tuber borchii. The sequence data demonstrate that clustering also occurs in this ectomycorrhizal fungus. Within the TBNIR1 protein sequence, we identified three functional domains at conserved positions: the FAD box, the NADPH box and the two (Fe/S)-siroheme binding site signatures. We demonstrated that tbnir1 presents an expression pattern comparable to that of nitrate transporter. In fact, we found a strong down-regulation in the presence of primary nitrogen sources and a marked tbnir1 mRNA accumulation following transfer to either nitrate or nitrogen limited conditions. The real-time PCR assays of tbnir1 and nitrate transporter revealed that both nitrate transporter and nitrite reductase expression levels are about 15-fold and 10-fold higher in ectomycorrhizal tissues than in control mycelia, respectively. The results reported herein suggest that the symbiotic fungus Tuber borchii contributes to improving the host plant’s ability to make use of nitrate/nitrite in its nitrogen nutrition.

Seasonality of suicide: relationship with the reason for suicide.

Aims: This study set out to test the hypothesis that the suicides that can be attributed to a psychiatric illness show a higher seasonality than the suicides due to any other reason. Methods: All the suicides registered in Italy from 1984 to 2000 (57,796 deaths by suicide: males = 41,741, yearly rate = 11.3 per 100,000; females = 16,055, yearly rate = 4.0 per 100,000) were analyzed with circular statistic techniques, based on the maximization of mean vector length method and on the Rayleigh test. Results: The suicides clearly attributed to a psychiatric illness were 35.0% among males and 51.3% among females. An economic reason for suicide was more frequently found among males; somatic illness or sentimental reasons were equally distributed in both sexes. The suicides attributable to a psychiatric illness showed a significantly higher seasonal unevenness than the suicides attributable to somatic illness and to sentimental or economic reasons. Conclusions: The main drawback of this study is that psychiatric diagnoses were not formally assessed by a forensic specialist. However, it succeeded in showing that the dynamics of suicidal behaviour are not unilineal: suicides due to psychiatric or somatic illness mainly happen in spring/summer and those due to economic difficulties mainly in December. Patients with psychiatric and/or somatic illness should be more carefully followed in spring/summer.

Creatine affects in vitro electrophysiological maturation of neuroblasts and protects them from oxidative stress.

Creatine (Cr) is a very popular ergogenic molecule that has recently been shown to have antioxidant properties. The effectiveness of Cr supplementation in treating neurological diseases and Cr deficiency syndromes has been demonstrated, and experimental reports suggest that it plays an important role in CNS development. In spite of this body of evidence, the role of Cr in functional and structural neuronal differentiation is still poorly understood. Here we used electrophysiological, morphological, and biochemical approaches to study the effects of Cr supplementation on in vitro differentiation of spinal neuroblasts under standard conditions or subjected to oxidative stress, a status closely related to perinatal hypoxia‐ischemia, a severe condition for developing brain. Cr supplementation (10 and 20 mM) completely prevented the viability decrease and neurite development impairment induced by radical attack, as well as nonprotein sulphydryl antioxidant pool depletion. Similar results were obtained using the antioxidant trolox. Furthermore, Cr supplementation induced a significant and dose‐dependent anticipation of Na+ and K+ current expression during the period of in vitro network building. Consistently with the latter finding, higher excitability, expressed as number of spikes following depolarization, was found in supplemented neuroblasts. All effects were dependent on the cytosolic fraction of Cr, as shown using a membrane Cr‐transporter blocker. Our results indicate that Cr protects differentiating neuroblasts against oxidative insults and, moreover, affects their in vitro electrophysiological maturation, suggesting possibly relevant effects of dietary Cr supplementation on developing CNS.

Breeding habitat of red-backed shrike Lanius collurio on farmland hilly areas of Central Italy: is functional heterogeneity one important key?

This paper examines the relationships between breeding site selection of red-backed shrikes Lanius collurio and land-use features using GIS. We examine the habitat preference of this species in areas characterised by a temperate climate and by a prevailing agricultural cover. We focused on the occurrence of red-backed shrike in relation to fragmentation, patch diversity and a few habitat features of the farmlands, as a surrogate for functional heterogeneity. We also studied several parameters such as the number of closely located nests, minimum distance between the nests and elevation above sea level of the breeding sites. Our results confirm the importance of the marginal elements such as shrubs, hedgerows and scatter patches in farmlands, and could add an effective method for studying suitable habitats for L. collurio using few environmental parameters. Our results suggest that breeding sites of the species are located mainly in cultivated zones, characterised by the presence of dispersal shrub patches and high edge density values and in proximity to the roads. Our results confirm also that landscape heterogeneity is one of the key factors in the selection of breeding habitat for red-backed shrikes in farmland of Central Italy, and therefore should be subject to agricultural policies aimed at conservation and maintenance of these environmental features.

Physiologic Responses of Firefighter Recruits During a Supervised Live-Fire Work Performance Test

Del Sal, M, Barbieri, E, Garbati, P, Sisti, D, Rocchi, MBL, and Stocchi, V. Physiologic responses of firefighter recruits during a supervised live-fire work performance test. J Strength Cond Res 23(8): 2396-2404, 2009-The aim of this research was to determine physiologic responses to typical activities of military Italian firefighters. Heart rate (HR), metabolic equivalent units (MET), skin temperature ( T.Sk.), and galvanic skin response (GSR) were measured in 13 firefighters (age = 36.3 ± 6.9 yr; period of military fire service = 16.8 ± 7 yr) during the acclimation phase (5 min standing, still dressed in their protective clothing), the work phase (simulated firefighting situations), and the following 24 hours. Multivariate linear step-wise regression showed that body mass index was highly correlated with mean and minimal HR values during the acclimation phase (beta 0.59, p < 0.001; beta 1.90, p = 0.003) and with mean and maximum HR values during the work phase (beta 1.08, p = 0.05; beta 1.17, p = 0.04), increasing cardiovascular stress. Firefighting tasks were associated with high energy expenditure. The minimum and mean MET values, during the acclimation phase, were significantly correlated with age (beta 0.49, p = 0.008 and beta 0.46, p < 0.01). During the work phase, maximal MET values were also strongly correlated with weight (beta 0.51, p = 0.03). No correlations between predictor and dependent variables were found for GSR; however, the high GSR levels recorded during the work phase returned to normal values only 12 hours after completion of the work phase, indicating that high levels of psychological stress remain, even after physical recovery. The data obtained in this study demonstrate that the physical fitness and anthropometric characteristics of firefighters influence the performance of firefighting tasks. These results may be useful to set up specific training that meets the real needs of firefighters in terms of physical fitness.