43 research outputs found
Struttura delle comunità zoobentoniche del Rio Bunnari (Sardegna settentrionale)
Temporal and spatial variation of macrozoobenthic communities
along the Rio Bunnari was studied. Three areas were sampled
according to E.B.I. index method in autumn and spring. In
the high and down stream a notable number of taxa was present,
whereas in the medium zone, down of the artificial lake,
most stenoecious taxa desappeared. This fact could be related
to the high eutrophication level of the lake that represents a
local limited environmental disturbance. Down stream of this zone
the presence of a rich macrozoobenthic community showed
its notable potentialities of homeostasis evidenced also by the
biotic index
Spongillidi (Porifera, Demospongiae) del Fiume Temo (Sardegna nord-occidentale)
This work concerns a) presence, distribution and life cycle of
spongillids from River Temo catchment basin and b) possible
morpho-functional and life cycle adaptations in relation to environmental
conditions. Samplings were carried out from 1984
to 1993 in seven sites located on the principal water-course and
tributaries. Results showed the presence of sponges, in all stations
but the river mouth, belonging to Ephydatia fluviatilis. The
presence of only this species seems to be related to its great plasticity
allowing to adapt populations to a large range of water
and climatic regimes. The steady presence of gemmules in all
seasons may be seen as a strategy to face springer-autumnal
floods and summer drought. These sponges show a high morphological
uniformity, such as crusty shape and small size, whereas
gemmuloscleres morphometry is very variable
Macrozoobenthos del Fiume Silis (Sardegna settentrionale)
This research deals with the composition and structure of macrozoobenthic
community of River Silis, Northern Sardinia.
Samplings, carried out in different periods of the year, allowed
to display the seasonal evolution of communities. Results showed
a scarce diversification of taxa but a well structured community.
The recolonization, after summer drought, was also
observed. At the starting of this process the most resistent organisms
were present, and increasing the flow, new taxa appeared
raising notable values of density. Data, utilized to determine
the water quality by means of E.B.I. method, show that class
of River Silis varies from II-I in the upperstream to III-II in the
downstream. These results point-out a situation of environmental
disturbance due to urban wastes and summer drought
Sponges architecture by colour: new insights into the fibres morphogenesis, skeletal spatial layout and morpho-anatomical traits of a marine horny sponge species (Porifera)
This paper focuses on the skeletal architecture and morphotraits of the Mediterranean horny sponge Sarcotragus spinosulus (Demospongiae, Keratosa, Dictyoceratida, Irciniidae). This special endoskeletal system consists of a dense, variably complex connective architecture, which extends throughout the entire sponge body and is embedded in an abundant jelly-like extracellular matrix (ECM). To investigate the topographic arrangement and micro-morphotraits of these connective structures in detail and by colour, also during morphogenetic processes, histology techniques using light microscopy are essential. New information is provided on the coordinated morphogenetic processes that characterize the growth and assembly of collagenic prototype structures in the matrix of fibrous skeletal elements and drive skeleton remodelling. Our results also highlight some novelties and some remarkable peculiarities of fibrous, filamentous and fibrillar components at the levels of both composition and structure. The morphofunctional significance of skeletal architecture is suggested in the background of the anatomical complexity of S. spinosulus
Anaplasma phagocytophilum, Sardinia, Italy
Anaplasma phagocytophilum (formerly Ehrlichia phagocytophila), a tick-transmitted pathogen that infects several animal species, including humans (involved as accidental "dead-end" hosts), is the causative agent of human granulocytic anaplasmosis (HGA). It is a pathogen of veterinary importance responsible for tickborne fever of ruminants and for granulocytic anaplasmosis of horses and dogs). HGA was first described in the United States in 1994 and is emerging in Europe. Although only 2 human cases have been reported in Italy, serologic and molecular findings have shown A. phagocytophilum infections in dogs and Ixodes ricinus ticks. Incidence, prevalence, and public impact of HGA and horse granulocytic anaplasmosis are, therefore, unknown for this geographic area. From 1992 to 1996, an average rate of 13.4 cases/year/100,000 inhabitants of tick bite–related fever of unknown etiology has been reported on the island of Sardinia, Italy, which is considerably higher than the corresponding national average value of 2.1 cases/year/100,000 inhabitants. Moreover, 117 cases of tick bite–related fever, whose etiology remains obscure, have been reported from 1995 to 2002 in the central west coast area of the island. Local newspapers occasionally report deaths as a result of tick bites, although no HGA-associated deaths have been documented in Europe.This study investigated A. phagocytophilum in Sardinia
Evaluating the impact of different sequence databases on metaproteome analysis: insights from a lab-assembled microbial mixture
Metaproteomics enables the investigation of the protein repertoire expressed by complex microbial communities. However, to unleash its full potential, refinements in bioinformatic approaches for data analysis are still needed. In this context, sequence databases selection represents a major challenge.
This work assessed the impact of different databases in metaproteomic investigations by using a mock microbial mixture including nine diverse bacterial and eukaryotic species, which was subjected to shotgun metaproteomic analysis. Then, both the microbial mixture and the single microorganisms were subjected to next generation sequencing to obtain experimental metagenomic- and genomic-derived databases, which were used along with public databases (namely, NCBI, UniProtKB/SwissProt and UniProtKB/TrEMBL, parsed at different taxonomic levels) to analyze the metaproteomic dataset. First, a quantitative comparison in terms of number and overlap of peptide identifications was carried out among all databases. As a result, only 35% of peptides were common to all database classes; moreover, genus/species-specific databases provided up to 17% more identifications compared to databases with generic taxonomy, while the metagenomic database enabled a slight increment in respect to public databases. Then, database behavior in terms of false discovery rate and peptide degeneracy was critically evaluated. Public databases with generic taxonomy exhibited a markedly different trend compared to the counterparts. Finally, the reliability of taxonomic attribution according to the lowest common ancestor approach (using MEGAN and Unipept software) was assessed. The level of misassignments varied among the different databases, and specific thresholds based on the number of taxon-specific peptides were established to minimize false positives. This study confirms that database selection has a significant impact in metaproteomics, and provides critical indications for improving depth and reliability of metaproteomic results. Specifically, the use of iterative searches and of suitable filters for taxonomic assignments is proposed with the aim of increasing coverage and trustworthiness of metaproteomic data.</br
The oldest birotule-bearing freshwater sponges from the Upper Cretaceous–lower Paleocene Deccan volcanic-associated sediments of India
A new fossil occurrence of freshwater sponges (Porifera: Demospongiae) is reported from the Deccan volcanic associated
Naskal intertrappean locality, deposited in an interval of <100 kyr across the Cretaceous/Paleogene (K/Pg) boundary.
This is the oldest record of siliceous fossil birotule spicules (gemmuloscleres) belonging to asexual resting stages
typical of the order Spongillida. The analysis supports the ascription of these fossils to the family Palaeospongillidae.
The diagnosis and description of Longibirotula Pronzato and Manconi gen. nov. and its type species Longibirotula
antiqua Manconi and Samant sp. nov. from the Naskal intertrappean is based on skeletal and gemmular spicular morphotraits.
The findings have provided evidence of the presence of diversified groups of freshwater sponges during the
Late Cretaceous on the Indian subcontinent and Gondwanaland. From the biogeographic context, the findings track the
evolutionary trends of the oldest continental sponges in the Asian and Australasian/Insular Pacific regions
Different Molecular Signatures in Magnetic Resonance Imaging-Staged Facioscapulohumeral Muscular Dystrophy Muscles
Facioscapulohumeral muscular dystrophy (FSHD) is one of the most common muscular dystrophies and is characterized by a non-conventional genetic mechanism activated by pathogenic D4Z4 repeat contractions. By muscle Magnetic Resonance Imaging (MRI) we observed that T2-short tau inversion recovery (T2-STIR) sequences identify two different conditions in which each muscle can be found before the irreversible dystrophic alteration, marked as T1-weighted sequence hyperintensity, takes place. We studied these conditions in order to obtain further information on the molecular mechanisms involved in the selective wasting of single muscles or muscle groups in this disease
Oral ondansetron versus domperidone for symptomatic treatment of vomiting during acute gastroenteritis in children: multicentre randomized controlled trial
<p>Abstract</p> <p>Background</p> <p>Vomiting in children with acute gastroenteritis (AG) is not only a direct cause of fluid loss but it is also a major factor of failure of oral rehydration therapy (ORT). Physicians who provide care to paediatric patients in the emergency department (ED) usually prescribe intravenous fluid therapy (IVT) for mild or moderate dehydration when vomiting is the major symptom. Thus, effective symptomatic treatment of vomiting would lead to an important reduction in the use of IVT and, consequently, of the duration of hospital stay and of frequency of hospital admission. Available evidence on symptomatic treatment of vomiting shows the efficacy of the most recently registered molecule (ondansetron) but a proper evaluation of antiemetics drugs largely used in clinical practice, such as domperidone, is lacking.</p> <p>Objectives</p> <p>To compare the efficacy of ondansetron and domperidone for the symptomatic treatment of vomiting in children with AG who have failed ORT.</p> <p>Methods/Design</p> <p>Multicentre, double-blind randomized controlled trial conducted in paediatric EDs. Children aged from 1 to 6 years who vomiting, with a presumptive clinical diagnosis of AG, and without severe dehydration will be included. After the failure of a initial ORS administration in ED, eligible children will be randomized to receive: 1) ondansetron syrup (0,15 mg/Kg of body weight); 2) domperidone syrup (0,5 mg/Kg of body weight); 3) placebo. The main study outcome will be the percentage of patients needing nasogastric or IVT after symptomatic oral treatment failure, defined as vomiting or fluid refusal after a second attempt of ORT. Data relative to study outcomes will be collected at 30 minute intervals for a minimum of 6 hours. A telephone follow up call will be made 48 hours after discharge. A total number of 540 children (i.e. 180 patients in each arm) will be enrolled.</p> <p>Discussion</p> <p>The trial results would provide evidence on the efficacy of domperidone, which is largely used in clinical practice despite the lack of proper evaluation and a controversial safety profile, as compared to ondansetron, which is not yet authorized in Italy despite evidence supporting its efficacy in treating vomiting. The trial results would contribute to a reduction in the use of IVT and, consequently, in hospital admissions in children with AG. The design of this RCT, which closely reflect current clinical practice in EDs, will allow immediate transferability of results.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT01257672">NCT01257672</a></p
Impact of pe_pgrs33 gene polymorphisms on mycobacterium tuberculosis infection and pathogenesis
PE_PGRS33 is a surface-exposed protein of Mycobacterium tuberculosis (Mtb) which exerts its role in macrophages entry and immunomodulation. In this study, we aimed to investigate the polymorphisms in the pe_pgrs33 gene of Mtb clinical isolates and evaluate their impact on protein functions. We sequenced pe_pgrs33 in a collection of 135 clinical strains, genotyped by 15-loci MIRU-VNTR and spoligotyping and belonging to the Mtb complex (MTBC). Overall, an association between pe_pgrs33 alleles and MTBC genotypes was observed and a dN/dS ratio of 0.64 was obtained, suggesting that a purifying selective pressure is acting on pe_pgrs33 against deleterious SNPs. Among a total of 19 pe_pgrs33 alleles identified in this study, 5 were cloned and used to complement the pe_pgrs33 knock-out mutant strain of Mtb H37Rv (Mtb\uce\u9433) to assess the functional impact of the respective polymorphisms in in vitro infections of primary macrophages. In human monocyte-derived macrophages (MDMs) infection, large in-frame and frameshift mutations were unable to restore the phenotype of Mtb H37Rv, impairing the cell entry capacity of Mtb, but neither its intracellular replication rate nor its immunomodulatory properties. In vivo studies performed in the murine model of tuberculosis (TB) demonstrated that the Mtb\uce\u9433 mutant strain was not impaired in the ability to infect and replicate in the lung tissue compared to the parental strain. Interestingly, Mtb\uce\u9433 showed an enhanced virulence during the chronic steps of infection compared to Mtb H37Rv. Similarly, the complementation of Mtb\uce\u9433 with a frameshift allele also resulted in a Mtb strain capable of causing a surprisingly enhanced tissue damage in murine lungs, during the chronic steps of infection. Together, these results further support the role of PE_PGRS33 in the pathogenesis and virulence of Mtb