353 research outputs found
Assembly of the Auditory Circuitry by a Hox Genetic Network in the Mouse Brainstem
Rhombomeres (r) contribute to brainstem auditory nuclei during development. Hox genes are determinants of rhombomere-derived fate and neuronal connectivity. Little is known about the contribution of individual rhombomeres and their associated Hox codes to auditory sensorimotor circuitry. Here, we show that r4 contributes to functionally linked sensory and motor components, including the ventral nucleus of lateral lemniscus, posterior ventral cochlear nuclei (VCN), and motor olivocochlear neurons. Assembly of the r4-derived auditory components is involved in sound perception and depends on regulatory interactions between Hoxb1 and Hoxb2. Indeed, in Hoxb1 and Hoxb2 mutant mice the transmission of low-level auditory stimuli is lost, resulting in hearing impairments. On the other hand, Hoxa2 regulates the Rig1 axon guidance receptor and controls contralateral projections from the anterior VCN to the medial nucleus of the trapezoid body, a circuit involved in sound localization. Thus, individual rhombomeres and their associated Hox codes control the assembly of distinct functionally segregated sub-circuits in the developing auditory brainstem
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Decomposition of carboxymethyl cellulose based on nano-knife principle
The traditional degradation of organic pollutants is based on the sacrifice of chemical or biological reagents. In this study, a purely physical technique was developed to break the chemical bonds and consequently decompose macromolecules in aqueous solution. Assisted with a high-speed mechanical blade, refined quartz sand grains with particularly sharp nano-scale edges can act as ânano-knivesâ, which are able to cut the long chain of carboxymethyl cellulose (CMC, as a model molecule). High performance size exclusion chromatography measurements evidenced that the original CMC molecules (41000 Da) were decomposed into a series of smaller molecules (460, 1000, 2200, 21,000, 27,000 and 31,000 Da). Consequently, the initial viscosity of the CMC solution (2 g/L) rapidly decreased by approximately 50% after 3 min treatment by the nano-knife materials along with the mechanical blade. Fourier transform infrared (FTIR) spectra indicated that the original functional groups were 1 still present and new functional groups were not produced after shearing. The intensity of the main functional group ÎČ-1-4-glycosidic bond (wavenumber 1062 cm-1) was observed to markedly decrease after shearing. These results indicated that the long-chain CMC was cleaved into short-chain CMC. A degradation mechanism was proposed whereby the cutting force generated by the rapid motion of the nano-knives may be responsible for the breakage of ÎČ-1-4-glycosidic bonds in the macromolecular cellulose backbone. These results provide support for a potentially more affordable and environment-friendly strategy for physical-based decomposition of recalcitrant organic pollutants from aqueous solution without the need of chemical or biological reagents
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The importance of incorporating soil in the life cycle assessment procedure to improve the sustainability of agricultural management
The formidable ability of soil to store carbon has attracted an increasing number of studies, but few of them included soil organic carbon (SOC) sequestration as part of a carbon balance assessment in the agroecosystem. This raises some interesting questions: 1) how orchards conversion increase soil capacity to mitigate the greenâhouse gases (GHG) emissions by storing C? 2) can it be considered in life cycle assessment (LCA)? 3) can SOC pools and soil biochemical properties determination improve LCA interpretation? To answer these questions, this study selected a tenâ and fifteenâyearsâold peach orchards, a twentyâyearsâold pear orchard, a thirtyâyearsâold kiwi orchard in south-east part of EmiliaâRomagna Region (Italy), and a cerealsâ field as reference. Soil samples were collected from 0 to 15 and 15â30 cm depths, and the SOC pool amounts (i.e., labile and recalcitrant) determined. LCA was used to estimate the GHG emissions (CO2eq) from the orchards. Results showed that the conversion from cereals to orchard production increased OC stock (+82 % on average) suggesting that orchards cultivation systems have the capacity to enrich soil organic matter. Fertilization had the greatest impact on CO2eq emission accounting for at least 40 % of total CO2eq emissions. Kiwi cultivation had the highest impact on GHG emissions mainly due to the high water and nutrient demand (0.045 and 0.149 kg CO2eq kgâ1 fruit yrâ1, respectively). When taking into account the CâCO2eq loss by fruit cultivation and C storage in soils, results would indicate that peach and pear orchard agroecosystems promote C sequestration. Conversely, kiwi cultivation showed large CO2eq emissions only partly counterbalanced by SOC sequestration. This study highlights the importance of including soils in LCA: if made mandatory this would allow a wider, yet more detailed, picture of the impact of agricultural practices on C budget. This simple step could help optimise resource management and at the same time improve agroecosystem sustainability
Skeptical Look at the Clinical Implication of Metabolic Syndrome in Childhood Obesity
Metabolic syndrome (MetS) is defined by a cluster of several cardio-metabolic risk factors, specifically visceral obesity, hypertension, dyslipidemia, and impaired glucose metabolism, which together increase risks of developing future cardiovascular disease (CVD) and type 2 diabetes mellitus (T2D). This article is a narrative review of the literature and a summary of the main observations, conclusions, and perspectives raised in the literature and the study projects of the Working Group of Childhood Obesity (WGChO) of the Italian Society of Paediatric Endocrinology and Diabetology (ISPED) on MetS in childhood obesity. Although there is an agreement on the distinctive features of MetS, no international diagnostic criteria in a pediatric population exist. Moreover, to date, the prevalence of MetS in childhood is not certain and thus the true value of diagnosis of MetS in youth as well as its clinical implications, is unclear. The aim of this narrative review is to summarize the pathogenesis and current role of MetS in children and adolescents with particular reference to applicability in clinical practice in childhood obesity
A posteriori error estimates for the virtual element method
An a posteriori error analysis for the virtual element method (VEM) applied to general elliptic problems is presented. The resulting error estimator is of residual-type and applies on very general polygonal/polyhedral meshes. The estimator is fully computable as it relies only on quantities available from the VEM solution, namely its degrees of freedom and element-wise polynomial projection. Upper and lower bounds of the error estimator with respect to the VEM approximation error are proven. The error estimator is used to drive adaptive mesh refinement in a number of test problems. Mesh adaptation is particularly simple to implement since elements with consecutive co-planar edges/faces are allowed and, therefore, locally adapted meshes do not require any local mesh post-processing
Clinical and epidemiological correlates of antibody response to human papillomaviruses (HPVs) as measured by a novel ELISA based on denatured recombinant HPV16 late (L) and early (E) antigens
<p>Abstract</p> <p>Background</p> <p>At present, seroreactivity is not a valuable parameter for diagnosis of Human Papillomavirus (HPV) infection but, it is potentially valuable as marker of viral exposure in elucidating the natural history of this infection. More data are needed to asses the clinical relevance of serological response to HPV.</p> <p>Objectives</p> <p>The objective was to assess the clinical and epidemiological correlates of HPV-seroreactivity in a cohort of HIV-negative and HIV-positive women.</p> <p>Methods</p> <p>Seroreactivity of 96 women, evaluated in an ELISA test based on denatured HPV16 late (L) and early (E) antigens, was correlated with their clinical and epidemiological data previously collected for a multi-centre Italian study, HPV-PathogenISS study.</p> <p>Results</p> <p>No significant correlation was found between HPV DNA detection and seroreactivity. Women, current smokers showed significantly less seroreactivity to L antigens as compared with the non-smokers. HIV-positive women showed significantly less (66.7%) antibody response as compared with HIV-negative women (89.3%), with particularly impaired response to L antigens. Women, HIV-positive and current smokers, showed by far the lowest seroprevalence (33.3%) as compared to 75.9% among all other women (OR = 0.158; 95%CI 0.036â0.695, p = 0.014; Fisher's exact test). Importantly, this association did not loose its significance when controlled for confounding from age (continuous variable) in multivariate analysis or using Mantel-Haenszel test for age-groups.</p> <p>Conclusion</p> <p>It is tempting to speculate that HIV-positive current smokers comprise a special high-risk group, with highly impaired immunological response that could prevent eradication of persistent HPV infections and thus contribute to development of CIN3/CC.</p
Effects on quality of life of weekly docetaxel-based chemotherapy in patients with locally advanced or metastatic breast cancer: results of a single-centre randomized phase 3 trial
<p>Abstract</p> <p>Background</p> <p>To evaluate whether weekly schedules of docetaxel-based chemotherapy were superior to 3-weekly ones in terms of quality of life in locally advanced or metastatic breast cancer.</p> <p>Methods</p> <p>Patients with locally advanced or metastatic breast cancer, aged †70 years, performance status 0-2, chemotherapy-naive for metastatic disease, were eligible. They were randomized to weekly or 3-weekly combination of docetaxel and epirubicin, if they were not treated with adjuvant anthracyclines, or docetaxel and capecitabine, if treated with adjuvant anthracyclines. Primary end-point was global quality of life change at 6-weeks, measured by EORTC QLQ-C30. With two-sided alpha 0.05 and 80% power for 35% effect size, 130 patients per arm were needed.</p> <p>Results</p> <p>From February 2004 to March 2008, 139 patients were randomized, 70 to weekly and 69 to 3-weekly arm; 129 and 89 patients filled baseline and 6-week questionnaires, respectively. Global quality of life was better in the 3-weekly arm (p = 0.03); patients treated with weekly schedules presented a significantly worsening in role functioning and financial scores (p = 0.02 and p < 0.001). Neutropenia and stomatitis were worse in the 3-weekly arm, where two toxic deaths were observed. Overall response rate was 39.1% and 33.3% in 3-weekly and weekly arms; hazard ratio of progression was 1.29 (95% CI: 0.84-1.97) and hazard ratio of death was 1.38 (95% CI: 0.82-2.30) in the weekly arm.</p> <p>Conclusions</p> <p>In this trial, the weekly schedules of docetaxel-based chemotherapy appear to be inferior to the 3-weekly one in terms of quality of life in patients with locally advanced or metastatic breast cancer.</p> <p>Trial registration</p> <p>ClinicalTrials.gov <a href="http://www.clinicaltrials.gov/ct2/show/NCT00540800">NCT00540800</a>.</p
Influenza vaccine uptake among community-dwelling Italian elderly: results from a large cross-sectional study
<p>Abstract</p> <p>Background</p> <p>Flu vaccination significantly reduces the risk of serious complications like hospitalization and death among community-dwelling older people, therefore vaccination programmes targeting this population group represent a common policy in developed Countries. Among the determinants of vaccine uptake in older age, a growing literature suggests that social relations can play a major role.</p> <p>Methods</p> <p>Drawing on the socio-behavioral model of Andersen-Newman - which distinguishes predictors of health care use in predisposing characteristics, enabling resources and need factors - we analyzed through multilevel regressions the determinants of influenza immunization in a sample of 25,183 elderly reached by a nationally representative Italian survey.</p> <p>Results</p> <p>Being over 85-year old (OR = 1.99; 95% CI 1.77 - 2.21) and suffering from a severe chronic disease (OR = 2.06; 95% CI 1.90 - 2.24) are the strongest determinants of vaccine uptake. Being unmarried (OR = 0.81; 95% CI 0.74 - 0.87) and living in larger households (OR = 0.83; 95% CI 0.74 - 0.87) are risk factors for lower immunization rates. Conversely, relying on neighbors' support (OR = 1.09; 95% CI 1.02 - 1.16) or on privately paid home help (OR = 1.19; 95% CI 1.08 - 1.30) is associated with a higher likelihood of vaccine uptake.</p> <p>Conclusions</p> <p>Even after adjusting for socio-demographic characteristics and need factors, social support, measured as the availability of assistance from partners, neighbors and home helpers, significantly increases the odds of influenza vaccine use among older Italians.</p
Identification of Novel Linear Megaplasmids Carrying a Ă-Lactamase Gene in Neurotoxigenic Clostridium butyricum Type E Strains
Since the first isolation of type E botulinum toxin-producing Clostridium butyricum from two infant botulism cases in Italy in 1984, this peculiar microorganism has been implicated in different forms of botulism worldwide. By applying particular pulsed-field gel electrophoresis run conditions, we were able to show for the first time that ten neurotoxigenic C. butyricum type E strains originated from Italy and China have linear megaplasmids in their genomes. At least four different megaplasmid sizes were identified among the ten neurotoxigenic C. butyricum type E strains. Each isolate displayed a single sized megaplasmid that was shown to possess a linear structure by ATP-dependent exonuclease digestion. Some of the neurotoxigenic C. butyricum type E strains possessed additional smaller circular plasmids. In order to investigate the genetic content of the newly identified megaplasmids, selected gene probes were designed and used in Southern hybridization experiments. Our results revealed that the type E botulinum neurotoxin gene was chromosome-located in all neurotoxigenic C. butyricum type E strains. Similar results were obtained with the 16S rRNA, the tetracycline tet(P) and the lincomycin resistance protein lmrB gene probes. A specific mobA gene probe only hybridized to the smaller plasmids of the Italian C. butyricum type E strains. Of note, a Ă-lactamase gene probe hybridized to the megaplasmids of eight neurotoxigenic C. butyricum type E strains, of which seven from clinical sources and the remaining one from a food implicated in foodborne botulism, whereas this Ă-lactam antibiotic resistance gene was absent form the megaplasmids of the two soil strains examined. The widespread occurrence among C. butyricum type E strains associated to human disease of linear megaplasmids harboring an antibiotic resistance gene strongly suggests that the megaplasmids could have played an important role in the emergence of C. butyricum type E as a human pathogen
Bioethical and medico-legal implications of withdrawing artificial nutrition and hydration from adults in critical care
The withdrawal of artificial nutrition and hydration or other life-sustaining treatments is a clinical decision, made in ICUs or in other settings, involving patients suffering from serious and irreversible diseases or impaired consciousness. Such clinical decisions must be made in the best interests of the patient, and must respect the wishes previously expressed by patients, laid down in their wills, in advance directives or in information passed on by relatives or legally appointed health-care agents, and in observance of common bioethical and legal rules in individual nations. Intensivists who are expert in the management of lifesustaining treatments are also involved in deciding when to withdraw futile therapies and instigate end-of-life care procedures for dying patients, with the sole aim of providing comfort and ensuring that suffering is not prolonged unnecessaril
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