53 research outputs found
Viral abundance and genome size distribution in the sediment and water column of marine and freshwater ecosystems
The size distribution of viral DNA in natural samples was investigated in a number of marine, brackish and freshwater environments by means of pulsed field gel electrophoresis (PFGE). The method was modified to work with both water and sediment samples, with an estimated detection limit for individual virus genome size groups of 1-2 × 104 virus-like particles (VLP) mL−1 water and 2-4 × 105 VLP cm−3 sediment in the original samples. Variations in the composition and distribution of dominant virus genome sizes were analyzed within and between different habitats that covered a range in viral density from 0.4 × 107 VLP mL−1 (sea water) to 300 × 107 VLP cm−3 (lake sediment). The PFGE community fingerprints showed a number of cross-system similarities in the genome size distribution with a general dominance of genomes in the 30-48, 50-70 and 145-200 kb size fractions, and with many of the specific genome sizes detected in all the investigated habitats. However, large differences in community fingerprints were also observed between the investigated sites, and some virus genome sizes were found only in specific biotopes (e.g. lake water), in specific ecosystems (e.g. a particular lake) or even in specific microhabitats (e.g. a particular sediment stratum
Hemostasis in uncontrolled esophageal variceal bleeding by self-expanding metal stents. A systematic review
Aim: The aim of this systematic review was to evaluate the current reported efficacy and the mortality rate of SEMS
treatment in uncontrolled bleeding patients.
Background: Esophageal variceal bleeding (EVB) represents a life threatening pathology. Despite the adequate
pharmacologic and endoscopic treatment, continuous or recurrent bleeding, named as uncontrolled bleeding, occurs in
10-20% of cases. A new removable, covered, and self-expanding metal stent (SEMS) was proposed to control the
variceal bleeding.
Materials and methods: The study was conducted according to the PRISMA statement. Studies were identified by
searching MEDLINE (1989-present) and SCOPUS (1989-present) databases. The last search was run on 01 July 2015.
Results: Nine studies (period range=2002-2015) met the inclusion criteria and were included in quantitative analysis.
High rate of SEMS efficacy in controling acute bleeding was observed, with a reported percentage ranging from 77.7 to
100%. In 10% to 20% of patients, re-bleeding occurred with SEMS in situ. Stent deployment was successful in 77.8% to
100% of patients while 11 to 36.5% of patients experienced stent migration.
Conclusion: SEMS could be effective and safe in control EVB and can be proposed as a reliable option to ballon
tamponed for patient stabilization and as a bridging to other therapeutic approach.
Keywords: Nonselective β-blockers, TIPSS, Endoscopic band ligation, Uncontrolled bleeding, Selfexpanding
metal stent
Microbial communities in contrasting freshwater marsh microhabitats
Heterotrophic microorganisms are widely recognized as crucial components of ecosystems; yet information on their community structure and dynamics in benthic freshwater habitats is notably scarce. Using denaturing gradient gel electrophoresis (DGGE), we determined the composition of bacterial and fungal communities in a freshwater marsh over four seasons. DGGE revealed diverse bacterial communities in four contrasting microhabitats. The greatest compositional differences emerged between water-column and surface-associated bacteria, although communities associated with sediment also differed from those on plant litter and epiphytic biofilms. Sequences of bacterial clones derived from DGGE bands belonged to the Alphaproteobacteria (31%), Actinobacteria (19%) and Bacteriodetes (19%). Betaproteobacteria were notably absent. Fungal clones obtained from leaf litter were mainly Ascomycota, but two members of the Basidiomycota were also identified. Overall, habitat type was the most important factor explaining variation in bacterial communities among samples, whereas temporal patterns in community composition were less pronounced in spite of large seasonal variation in environmental conditions such as temperature. The observed differences among bacterial communities in different microhabitats were not caused by random variation, but rather appeared to be determined by habitat characteristics, as evidenced by largely congruent community profiles of replicate samples taken at 10-100m distances within the mars
Fibrisoma limi gen. nov., sp. nov., an orange pigmented filamentous bacterium of the family Cytophagaceae isolated from North Sea tidal flats
An orange pigmented Gram-staining-negative, non motile, filament forming rod-shaped bacterium (BUZ 3T) was isolated from a coastal mud sample from the North Sea (Fedderwardersiel, Germany) and characterized taxonomically using a polyphasic approach. According to 16S rRNA gene sequence data it belongs the family Cytophagaceae, exhibiting low 16S rRNA gene sequence similarity (<90%) to members of the genera Spirosoma, Rudanella and Fibrella. The G+C content was 52.0 mol%. The major fatty acids were summed feature 3 (comprising C16:1{omega}7c and/or isoC15:0 2-OH), C16:1{omega}5c, and isoC17:0 3-OH. The major polar lipids consisted of phosphatidylethanolamine, and several aminolipids. On the basis of phenotypic, chemotaxonomic and phylogenetic data, it is proposed that, strain BUZ 3T represents a strain of a novel genus and species, for which the name Fibrisoma limi gen. nov., sp. nov. is proposed. The type strain is BUZ 3T (= DSMZ 22564T = CCUG 58137T
Low virus to prokaryote ratios in the cold: benthic viruses and prokaryotes in a subpolar marine ecosystem (Hornsund, Svalbard)
The density and spatial distribution of benthic viruses and prokaryotes in relation to biotic and abioticfactors were investigated in sediment cores collected in Hornsund, a permanently cold fjord on the West coast of Svalbard,Norway. The cores were obtained from the mouth of the fjord to the central basin, along a longitudinal transect. Theresults of our analyses showed lower densities of viruses (0.2 × 108 to 5.4 × 108 virus-like particles/g) and lower virus-toprokaryoteratios (0.2-0.6, with the exception of the uppermost layer in the central basin, where the ratio was about 1.2)at the study site than generally found in the temperate areas, despite the relatively high organic matter content in subpolarsediments. Variations in benthic viral and prokaryote abundances along gradients of particle sedimentation rates, phytopigmentconcentrations, and macrobenthic species composition together suggested the influence of particle sedimentationand macrobenthic bioturbation on the abundance and spatial distribution of prokaryotes and viruses in cold habitats. [IntMicrobiol 2013; 16(1):45-52
Environmental and lifestyle risk factors for early-onset dementia: a systematic review
The term early-onset dementia (EOD) encompasses several forms of neurodegenerative diseases characterized by symptom onset before 65 years and leading to severe impact on subjects already in working activities, as well as on their family and caregivers. Despite the increasing incidence, the etiology is still unknown, with possible association of environmental factors, although the evidence is still scarce. In this review, we aimed to assess how several environmental and lifestyle factors may be associated with the onset of this disease
Dietary Habits and Risk of Early-Onset Dementia in an Italian Case-Control Study
Risk of early-onset dementia (EOD) might be modified by environmental factors and lifestyles, including diet. The aim of this study is to evaluate the association between dietary habits and EOD risk. We recruited 54 newly-diagnosed EOD patients in Modena (Northern Italy) and 54 caregivers as controls. We investigated dietary habits through a food frequency questionnaire, assessing both food intake and adherence to dietary patterns, namely the Greek-Mediterranean, the Dietary Approaches to Stop Hypertension (DASH), and the Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diets. We modeled the relation between dietary factors and risk using the restricted cubic spline regression analysis. Cereal intake showed a U-shaped relation with EOD, with risk increasing above 350 g/day. A high intake (>400 g/day) of dairy products was also associated with excess risk. Although overall fish and seafood consumption showed no association with EOD risk, we found a U-shaped relation with preserved/tinned fish, and an inverse relation with other fish. Similarly, vegetables (especially leafy) showed a strong inverse association above 100 g/day, as did citrus and dry fruits. Overall, sweet consumption was not associated with EOD risk, while dry cake and ice-cream showed a positive relation and chocolate products an inverse one. For beverages, we found no relation with EOD risk apart from a U-shaped relation for coffee consumption. Concerning dietary patterns, EOD risk linearly decreased with the increasing adherence to the MIND pattern. On the other hand, an inverse association for the Greek-Mediterranean and DASH diets emerged only at very high adherence levels. To the best of our knowledge, this is the first study that explores the association between dietary factors and EOD risk, and suggests that adherence to the MIND dietary pattern may decrease such risk
Selenoprotein P concentrations and risk of progression from mild cognitive impairment to dementia
: There is a growing literature investigating the effects of selenium on the central nervous system and cognitive function. However, little is known about the role of selenoprotein P, the main selenium transporter, which can also have adverse biological effects. We conducted a prospective cohort study of individuals aged 42-81 years who received a clinical diagnosis of mild cognitive impairment. Using sandwich ELISA methods, we measured full-length selenoprotein P concentrations in serum and cerebrospinal fluid to assess the relation with dementia incidence during a median follow-up of 47.3 months. We used Cox proportional hazards regression and restricted cubic splines to model such relation. Of the 54 participants, 35 developed dementia during follow-up (including 26 cases of Alzheimer's dementia). Selenoprotein P concentrations in serum and cerebrospinal fluid were highly correlated, and in spline regression analyses they each showed a positive non-linear association with dementia risk, particularly after excluding dementia cases diagnosed within 24 months of follow-up. We also observed differences in association according to the dementia subtypes considered. Risk ratios of dementia peaked at 2-6 at the highest levels of selenoprotein P, when compared to its median level, also depending on matrix, analytical methodology and dementia subtype. Findings of this study, the first to assess selenoprotein P levels in the central nervous system in vivo and the first to use a prospective study design to evaluate associations with dementia, suggest that higher circulating concentrations of selenoprotein P, both in serum and cerebrospinal fluid, predict progression of MCI to dementia. However, further confirmation of these findings is required, given the limited statistical precision of the associations and the potential for residual confounding
Diagnostic and Prognostic Value of microRNAs in Patients with Laryngeal Cancer: A Systematic Review
: Laryngeal squamous cell cancer (LSCC) is one of the most common malignant tumors of the head and neck region, with a poor survival rate (5-year overall survival 50-80%) as a consequence of an advanced-stage diagnosis and high recurrence rate. Tobacco smoking and alcohol abuse are the main risk factors of LSCC development. An early diagnosis of LSCC, a prompt detection of recurrence and a more precise monitoring of the efficacy of different treatment modalities are currently needed to reduce the mortality. Therefore, the identification of effective diagnostic and prognostic biomarkers for LSCC is crucial to guide disease management and improve clinical outcomes. In the past years, a dysregulated expression of small non-coding RNAs, including microRNAs (miRNAs), has been reported in many human cancers, including LSCC, and many miRNAs have been explored for their diagnostic and prognostic potential and proposed as biomarkers. We searched electronic databases for original papers that were focused on miRNAs and LSCC, using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol. According to the outcome, 566 articles were initially screened, of which 177 studies were selected and included in the analysis. In this systematic review, we provide an overview of the current literature on the function and the potential diagnostic and prognostic role of tissue and circulating miRNAs in LSCC
Selenoprotein P Concentrations in the Cerebrospinal Fluid and Serum of Individuals Affected by Amyotrophic Lateral Sclerosis, Mild Cognitive Impairment and Alzheimer’s Dementia
Selenoprotein P, a selenium-transporter protein, has been hypothesized to play a role in the etiology of neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS) and Alzheimer's dementia (AD). However, data in humans are scarce and largely confined to autoptic samples. In this case-control study, we determined selenoprotein P concentrations in both the cerebrospinal fluid (CSF) and the serum of 50 individuals diagnosed with ALS, 30 with AD, 54 with mild cognitive impairment (MCI) and of 30 controls, using sandwich enzyme-linked immunosorbent assay (ELISA) methods. We found a positive and generally linear association between CSF and serum selenoprotein P concentrations in all groups. CSF selenoprotein P and biomarkers of neurodegeneration were positively associated in AD, while for MCI, we found an inverted-U-shaped relation. CSF selenoprotein P concentrations were higher in AD and MCI than in ALS and controls, while in serum, the highest concentrations were found in MCI and ALS. Logistic and cubic spline regression analyses showed an inverse association between CSF selenoprotein P levels and ALS risk, and a positive association for AD risk, while an inverted-U-shaped relation with MCI risk emerged. Conversely, serum selenoprotein P concentrations were positively associated with risk of all conditions but only in their lower range. Overall, these findings indicate some abnormalities of selenoprotein P concentrations in both the central nervous system and blood associated with ALS and neurocognitive disorders, though in different directions. These alterations may reflect either phenomena of etiologic relevance or disease-induced alterations of nutritional and metabolic status
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