51 research outputs found
Disclosing arbuscular mycorrhizal fungal biodiversity in soil through a land-use gradient using a pyrosequencing approach
Application of laser microdissection to identify the mycorrhizal fungi that establish arbuscules inside root cells.
Obligate symbiotic fungi that form arbuscular mycorrhizae (AMF; belonging to the Glomeromycota phylum) are some of the most important soil microorganisms. AMFs facilitate mineral nutrient uptake from the soil, in exchange for plant-assimilated carbon, and promote water-stress tolerance and resistance to certain diseases. AMFs colonize the root by producing inter- and intra-cellular hyphae. When the fungus penetrates the inner cortical cells, it produces a complex ramified structure called arbuscule, which is considered the preferential site for nutrient exchange. Direct DNA extraction from the whole root and sequencing of ribosomal gene regions are commonly carried out to investigate intraradical AMF communities. Nevertheless, this protocol cannot discriminate between the AMFs that actively produce arbuscules and those that do not. To solve this issue, the authors have characterized the AMF community of arbusculated cells (AC) through a laser microdissection (LMD) approach, combined with sequencing-based taxa identification. The results were then compared with the AMF community that was found from whole root DNA extraction. The AMF communities originating from the LMD samples and the whole root samples differed remarkably. Five taxa were involved in the production of arbuscules, while two taxa were retrieved inside the root but not in the AC. Unexpectedly, one taxon was found in the AC, but its detection was not possible when extracting from the whole root. Thus, the LMD technique can be considered a powerful tool to obtain more precise knowledge on the symbiotically active intraradical AMF community
Arbuscular Mycorrhizal Fungi and their Value for Ecosystem Management
Arbuscular Mycorrhizal Fungi (AMF) are root obligate symbionts of nearly all the plants living on Earth. They are considered as living fossils: there are evidences that date back to 460 million years ago their presence on our planet. Taxonomically, they belong to the Glomeromycota phylum. They are found in roots of 80% of plant species and give and get back benefits to their partners, as happens in all mutual symbiotic relationships. They build up a bridge between plant and soil, growing their mycelia both inside and outside plant roots. AMF provide the plant with water, soil mineral nutrients (mainly phosphorus and nitrogen), and pathogen protection. In exchange, photosynthetic compounds are transferred to the fungus.
Besides physiological benefits to the host-plant, AMF play an important ecological role. They are important in soil structuring thanks to their thick extraradical hyphal network able to aggregate soil particles. They help plants establish in degraded ecosystems (e.g. desert areas and mine spoils) and positively affect phytoremediation. They can influence processes (i.e. soil carbon sequestration) related to climate change. Last but not least, their belowground presence and diversity can positively affect the aboveground plant biodiversity and productivity.
These roles played by AMF for the ecosystem functioning lead to consider them as key soil organisms. Therefore, every AMF aspect is extensively studied: from biological features, through biogeography and biodiversity, to phylogeny. [...]JRC.H.5-Land Resources Managemen
Fatal poisoning by ingestion of a self-prepared oleander leaf infusion
An unusual case of poisoning by the ingestion of oleander leaves is reported. A 71 year old male laboratory technician committed
suicide at home in this unusual manner. At the death scene a steel pan and other paraphernalia, used for the extraction
of oleandrin and other cardiac glycosides from the leaves of the Nerium oleander plant were found.
Toxicological investigations for oleandrin, oleandrigenin, neritaloside, and odoroside were performed by LC–MS/MS on
all biological samples (peripheral blood, vitreous humor, urine, liver, gastric contents) and on the yellow infusion found at
the death scene.
In all samples, toxic levels of oleandrin were detected (blood 37.5 ng/mL, vitreous humor 12.6 ng/mL, urine 83.8 ng/mL,
liver 205 ng/mg, gastric content 31.2 ÎĽg/mL, infusion 38.5 ÎĽg/mL). Qualitative results for oleandrigenin, neritaloside, and
odoroside were obtained. Oleandrigenin was present in all tissue samples whereas neritaloside and odoroside were absent
in the blood and vitreous humor but present in urine, liver, gastric content, and in the leaf brew.
The purpose of this study was the identification of oleandrin and its congener oleandrigenin, detected in the vitreous humor.
The blood/vitreous humor ratio was also calculated in order to assess of the likely time interval from ingestion to death.
According to the toxicological results death was attributed to fatal arrhythmia due to oleander intoxication. The manner of deathwas classified as suicide through the ingestion of the infusion
Fatal poisoning by ingestion of a self‑prepared oleander leaf infusion
An unusual case of poisoning by the ingestion of oleander leaves is reported. A 71 year old male laboratory technician committed suicide at home in this unusual manner. At the death scene a steel pan and other paraphernalia, used for the extraction of oleandrin and other cardiac glycosides from the leaves of the Nerium oleander plant were found.
Toxicological investigations for oleandrin, oleandrigenin, neritaloside, and odoroside were performed by LC–MS/MS on all biological samples (peripheral blood, vitreous humor, urine, liver, gastric contents) and on the yellow infusion found at the death scene. In all samples, toxic levels of oleandrin were detected (blood 37.5 ng/mL, vitreous humor 12.6 ng/mL, urine 83.8 ng/mL, liver 205 ng/mg, gastric content 31.2 µg/mL, infusion 38.5 µg/mL). Qualitative results for oleandrigenin, neritaloside, and odoroside were obtained. Oleandrigenin was present in all tissue samples whereas neritaloside and odoroside were absent in the blood and vitreous humor but present in urine, liver, gastric content, and in the leaf brew.
The purpose of this study was the identifcation of oleandrin and its congener oleandrigenin, detected in the vitreous humor. The blood/vitreous humor ratio was also calculated in order to assess of the likely time interval from ingestion to death. According to the toxicological results death was attributed to fatal arrhythmia due to oleander intoxication. The manner of death was classifed as suicide through the ingestion of the infusion
Mycobacterium tuberculosis SIT42 Infection in an Abused Dog in Southern Italy
A case of Mycobacterium tuberculosis infection is described in a dead adult male dog in Southern Italy. The carcass was found by the Health Authority in a gypsy encampment. It was admitted to our forensic veterinary medicine unit, with a suspicion of cruelty to the animal. Necropsy showed beating and traumatism signs, and mistreating was confirmed. Gross lesions included multiple nodular hepatic lesions, hemorrhagic enteritis with enlarged mesenteric lymph nodes, body cavity effusions, and an adrenal neoplasm. Bacteriological and molecular analyses were carried out on the liver lesions that enabled to identify M. tuberculosis SIT42 (LAM9). Drug-resistance patterns were evaluated by screening mutations on the rpoB and katG genes that showed susceptibility to both rifampin and isoniazid, respectively. Very few studies report canine tuberculosis, and little is known about the disease in Italy. To the authors' knowledge, this is the first report of Mycobacterium tuberculosis SIT42 infection in a dog in Italy
Stellar polytropes and Navarro-Frenk-White halo models: comparison with observations
Motivated by the possible conflict between the Navarro-Frenk-White(NFW) model
predictions for the dark matter contents of galactic systems and its
correlation with baryonic surface density, we will explore an alternative
paradigm for the description of dark matter halos. Such an alternative emerges
from Tsallis' non-extensive thermodynamics applied to self-gravitating systems
and leads to the so-called ``stellar polytrope'' (SP) model. We consider that
this could be a better approach to real structures rather than the isothermal
model, given the fact that the first one takes into account the non-extensivity
of energy and entropy present in these type of systems characterized by
long-range interactions. We compare a halo based on the Navarro-Frenk-White
(NFW) and one which follows the SP description. Analyzing the dark matter
contents estimated by means of global physical parameters of galactic disks,
obtained from a sample of actual galaxies, with the ones of the unobserved dark
matter halos, we conclude that the SP model is favored over the NFW model in
such a comparison.Comment: 21 pages, 4 figures. Accepted for publication in the Journal of
Cosmology and Astroparticle Physic
COVID-19 Severity in Multiple Sclerosis: Putting Data Into Context
Background and objectives: It is unclear how multiple sclerosis (MS) affects the severity of COVID-19. The aim of this study is to compare COVID-19-related outcomes collected in an Italian cohort of patients with MS with the outcomes expected in the age- and sex-matched Italian population. Methods: Hospitalization, intensive care unit (ICU) admission, and death after COVID-19 diagnosis of 1,362 patients with MS were compared with the age- and sex-matched Italian population in a retrospective observational case-cohort study with population-based control. The observed vs the expected events were compared in the whole MS cohort and in different subgroups (higher risk: Expanded Disability Status Scale [EDSS] score > 3 or at least 1 comorbidity, lower risk: EDSS score ≤ 3 and no comorbidities) by the χ2 test, and the risk excess was quantified by risk ratios (RRs). Results: The risk of severe events was about twice the risk in the age- and sex-matched Italian population: RR = 2.12 for hospitalization (p < 0.001), RR = 2.19 for ICU admission (p < 0.001), and RR = 2.43 for death (p < 0.001). The excess of risk was confined to the higher-risk group (n = 553). In lower-risk patients (n = 809), the rate of events was close to that of the Italian age- and sex-matched population (RR = 1.12 for hospitalization, RR = 1.52 for ICU admission, and RR = 1.19 for death). In the lower-risk group, an increased hospitalization risk was detected in patients on anti-CD20 (RR = 3.03, p = 0.005), whereas a decrease was detected in patients on interferon (0 observed vs 4 expected events, p = 0.04). Discussion: Overall, the MS cohort had a risk of severe events that is twice the risk than the age- and sex-matched Italian population. This excess of risk is mainly explained by the EDSS score and comorbidities, whereas a residual increase of hospitalization risk was observed in patients on anti-CD20 therapies and a decrease in people on interferon
Disease-Modifying Therapies and Coronavirus Disease 2019 Severity in Multiple Sclerosis
Objective: This study was undertaken to assess the impact of immunosuppressive and immunomodulatory therapies on the severity of coronavirus disease 2019 (COVID-19) in people with multiple sclerosis (PwMS).
Methods: We retrospectively collected data of PwMS with suspected or confirmed COVID-19. All the patients had complete follow-up to death or recovery. Severe COVID-19 was defined by a 3-level variable: mild disease not requiring hospitalization versus pneumonia or hospitalization versus intensive care unit (ICU) admission or death. We evaluated baseline characteristics and MS therapies associated with severe COVID-19 by multivariate and propensity score (PS)-weighted ordinal logistic models. Sensitivity analyses were run to confirm the results.
Results: Of 844 PwMS with suspected (n = 565) or confirmed (n = 279) COVID-19, 13 (1.54%) died; 11 of them were in a progressive MS phase, and 8 were without any therapy. Thirty-eight (4.5%) were admitted to an ICU; 99 (11.7%) had radiologically documented pneumonia; 96 (11.4%) were hospitalized. After adjusting for region, age, sex, progressive MS course, Expanded Disability Status Scale, disease duration, body mass index, comorbidities, and recent methylprednisolone use, therapy with an anti-CD20 agent (ocrelizumab or rituximab) was significantly associated (odds ratio [OR] = 2.37, 95% confidence interval [CI] = 1.18-4.74, p = 0.015) with increased risk of severe COVID-19. Recent use (<1 month) of methylprednisolone was also associated with a worse outcome (OR = 5.24, 95% CI = 2.20-12.53, p = 0.001). Results were confirmed by the PS-weighted analysis and by all the sensitivity analyses.
Interpretation: This study showed an acceptable level of safety of therapies with a broad array of mechanisms of action. However, some specific elements of risk emerged. These will need to be considered while the COVID-19 pandemic persists
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