380 research outputs found
Phase Transitions And Spatially Ordered Counterion Association In Ionic-lipid Membranes: A Statistical Model.
We propose a statistical model to account for the gel-fluid anomalous phase transitions in charged bilayer- or lamellae-forming ionic lipids. The model Hamiltonian comprises effective attractive interactions to describe neutral-lipid membranes as well as the effect of electrostatic repulsions of the discrete ionic charges on the lipid headgroups. The latter can be counterion dissociated (charged) or counterion associated (neutral), while the lipid acyl chains may be in gel (low-temperature or high-lateral-pressure) or fluid (high-temperature or low-lateral-pressure) states. The system is modeled as a lattice gas with two distinct particle types--each one associated, respectively, with the polar-headgroup and the acyl-chain states--which can be mapped onto an Ashkin-Teller model with the inclusion of cubic terms. The model displays a rich thermodynamic behavior in terms of the chemical potential of counterions (related to added salt concentration) and lateral pressure. In particular, we show the existence of semidissociated thermodynamic phases related to the onset of charge order in the system. This type of order stems from spatially ordered counterion association to the lipid headgroups, in which charged and neutral lipids alternate in a checkerboard-like order. Within the mean-field approximation, we predict that the acyl-chain order-disorder transition is discontinuous, with the first-order line ending at a critical point, as in the neutral case. Moreover, the charge order gives rise to continuous transitions, with the associated second-order lines joining the aforementioned first-order line at critical end points. We explore the thermodynamic behavior of some physical quantities, like the specific heat at constant lateral pressure and the degree of ionization, associated with the fraction of charged lipid headgroups.8403190
Effect of probiotics on oral candidiasis: A systematic review and meta-analysis
Oral candidiasis (OC) is an increasing health problem due to the introduction of new drugs, population aging, and increasing prevalence of chronic illness. This study systematically reviews the effects of the oral intake of probiotics, prebiotics, and synbiotics on Candida spp. counts (colony-forming units (CFU)/mL) in oral and palatal samples. A literature search was conducted. Twelve studies, eight randomized clinical trials (RCTs), and four pre-post studies, resulted as eligible for the meta-analysis, which was performed through a Bayesian random-effects model. All studies analyzed probiotics, and none of them analyzed prebiotics or synbiotics. The treatments effects were measured in terms of odds ratio (OR) of OC (CFU/mL >102, 103, or 104). The meta-analytic OR was 0.71 (95% credibility interval (CrI): 0.37, 1.32), indicating a beneficial effect of treatment; the I2 index was 56.3%. Focusing only on RCTs, the OR was larger and more precise at 0.53 (95% CrI: 0.27, 0.93). The effect of treatment appeared to be larger on denture wearers. Our findings indicate that the intake of probiotics can have a beneficial effect on OC and that the effects could vary according to the patients’ characteristics. Due to the presence of medium–high-risk studies, the results should be interpreted with caution
Vive la difference! the effects of natural and conventional wines on blood alcohol concentrations: A randomized, triple-blind, controlled study
Different alcoholic beverages can have different effects on blood alcohol concentration (BAC) and neurotoxicity, even when equalized for alcohol content by volume. Anecdotal evidence suggested that natural wine is metabolized differently from conventional wines. This triple-blind study compared the BAC of 55 healthy male subjects after consuming the equivalent of 2 units of alcohol of a natural or conventional wine over 3 min in two separate sessions, one week apart. BAC was measured using a professional breathalyzer every 20 min after consumption for 2 h. The BAC curves in response to the two wines diverged significantly at twenty minutes (interval T20) and forty minutes (interval T40), and also at their maximum concentrations (peaks), with the natural wine inducing a lower BAC than the conventional wine [T20 = 0.40 versus 0.46 (p < 0.0002); T40 = 0.49 versus 0.53 (p < 0.0015); peak = 0.52 versus 0.56 (p < 0.0002)]. These differences are likely related to the development of different amino acids and antioxidants in the two wines during their production. This may in turn affect the kinetics of alcohol absorption and metabolism. Other contributing factors could include pesticide residues, differences in dry extract content, and the use of indigenous or selected yeasts. The study shows that with the same quantity and conditions of intake, natural wine has lower pharmacokinetic and metabolic effects than conventional wine, which can be assumed due to the different agronomic and oenological practices with which they are produced. It can therefore be hypothesized that the consumption of natural wine may have a different impact on human health from that of conventional wine
RR5. Surgical Treatment of Popliteal Aneurysms Using a Posterior Approach: Thirteen Years' Follow-up
OBJECTIVES : Long-term results of posterior approach (PA) for the treatment of popliteal artery aneurysms are lacking in the literature. We compared our results with this access with those from a standard medial approach over a 13-years\u2019 period.
METHODS: Clinical data of all patients treated for a popliteal aneurysm between 2/1998 and 10/2011 were retrospectively reviewed and outcomes analyzed: Kaplan-Meier method with log-rank, chi2 and Wilcoxon test were employed for analysis.
RESULTS : A total of 78 aneurysms were treated in 66 patients (65 men). Mean age was 68 years (range 48-96 years).
Thirty-six aneurysms were asymptomatic (46%). Mean sac diameter was 2.9\ub11 cm. A PA was used in 43 cases (55%) and a medial approach (MA) in 35. All PA consisted in aneurysmectomy with an interposition graft with end to end anastomoses; among MA 25 interposition grafts and 10 bypass were performed. A PTFE graft was used mostly (57 cases). The two groups differed for age only (median 65.4 for PA vs. 72.9 for MA p=0.01). Five patients had an early thrombosis and required a Fogarty thrombectomy (2 PA and 3 MA, all PTFE grafts). Mortality rate at 30 days was 0%.
One patient suffered a peroneal nerve lesion (permanent) and another one a major wound necrosis with tissue loss (both PA). There were no early amputations. Median follow-up was 58.8 months (range 5 days-166.7 months).
Nine patients died during follow-up for unrelated causes. The 5-year primary and secondary patency rates were 58.9%\ub18,7% and 96.4%\ub13.5% respectively for PA, and 67.4%\ub110,4% and 81.3%\ub18,9% respectively for MA (p=0.41 for primary patency rate and 0.28 for secondary patency rate). Limb salvage was 100% and 93.3%\ub16.4% at 5 and 10 years respectively for PA and 91.5%\ub15.6% at both time points for MA (p=0.3).
CONCLUSIONS : PA in our experience was burdened by a few more early complications compared to MA. However in the long term it provided results which compare favorably to MA.
AUTHOR DISCLOSURES: I. Barbetta, Nothing to disclose; M. Carmo, Nothing to disclose; R. Dallatana, Nothing to disclose; G. Grava, Nothing to disclose; D. Mazzaccaro, Nothing to disclose; A. M. Settembrini, Nothing to disclose; P. Settembrini, Nothing to disclose
Relationships between technical efficiency and the quality and costs of health care in Italy†
Objectives This paper reports the measurement of technical efficiency of Tuscan Local Health Authorities and its relationship with quality and appropriateness of care. Design First, a bias-corrected measure of technical efficiency was developed using the bootstrap technique applied to data envelopment analysis. Then, correlation analysis was used to investigate the relationships among technical efficiency, quality and appropriateness of care. Setting and Participants These analyses have been applied to the Local Health Authorities of Tuscany Region (Italy), which provide not only hospital inpatient services, but also prevention and primary care. All top managers of Tuscan Local Health Authorities were involved in selection of the inputs and outputs for calculating technical efficiency. Main Outcome Measures The main measures used in this study are volume, quality and appropriateness indicators monitored by the multidimensional performance evaluation system developed in the Tuscany Region. Results On average, Tuscan Local Health Authorities experienced 14(%) of bias-corrected inefficiency in 2007. Correlation analyses showed a significant negative correlation between per capita costs and overall performance. No correlation was found in 2007 between technical efficiency and overall performance or between technical efficiency and per capita costs. Conclusions Technical efficiency cannot be considered as an extensive measure of healthcare performance, but evidence shows that Tuscan Local Health Authorities have room for improvement in productivity levels. Indeed, correlation findings suggest that, to pursue financial sustainability, Local Health Authorities mainly have to improve their performance in terms of quality and appropriateness
Polypeptide-grafted macroporous polyHIPE by surface-initiated N-Carboxyanhydride (NCA) polymerization as a platform for bioconjugation
A new class of functional macroporous monoliths from polymerized high internal phase emulsion (polyHIPE) with tunable surface functional groups was developed by direct polypeptide surface grafting. In the first step, amino-functional polyHIPEs were obtained by the addition of 4-vinylbenzyl or 4-vinylbenzylphthalimide to the styrenic emulsion and thermal radical polymerization. The obtained monoliths present the expected open-cell morphology and a high surface area. The incorporated amino group was successfully utilized to initiate the ring-opening polymer-
ization of benzyl-L-glutamate N-carboxyanhydride (BLG NCA) and benzyloxycarbonyl-L-lysine (Lys(Z)) NCA, which resulted in a dense homogeneous coating of polypeptides throughout the internal polyHIPE surfaces as confirmed by SEM and FTIR analysis. The amount of polypeptide grafted to the polyHIPE surfaces could be modulated by varying the initial ratio of amino acid NCA to amino-functional polyHIPE. Subsequent removal of the polypeptide protecting groups yielded highly functional polyHIPE-g-poly(glutamic acid) and polyHIPE-g- poly(lysine). Both types of polypeptide-grafted monoliths responded to pH by changes in their hydrohilicity. The possibility to use the high density of function (−COOH or −NH2) for secondary reaction was demonstrated by the successful bioconjugation of enhanced green fluorescent protein (eGFP) and fluorescein isocyanate (FITC) on the polymer 3D-scaffold surface. The amount of eGFP and FITC conjugated to the polypeptide-grafted polyHIPE was significantly higher than to the amino- functional polyHIPE, signifying the advantage of polypeptide grafting to achieve highly functional polyHIPEs
Effects of anti-IL5 biological treatments on blood IgE levels in severe asthmatic patients: A real-life multicentre study (BIONIGE)
Background: Mepolizumab and benralizumab are clinically effective biological treatments for severe eosinophilic asthmatic patients by hampering eosinophilic inflammation. The effects of these compound on the immunoglobulin (Ig)E T2 component are virtually unknown. Objectives: To evaluate the change in total IgE levels at 4 ± 2 months after initiation of the mepolizumab (primary outcome) or benralizumab. When available, the changes of blood inflammatory cell counts, lung function and asthma control test (ACT) were also assessed and correlated with changes in total IgE levels. Methods: Observational, retrospective, multicentre, cohort study. Severe eosinophilic atopic asthmatic patients treated with mepolizumab or benralizumab were included in the analysis. Results: Three-month treatment (on average) with mepolizumab (n = 104) or benralizumab (n = 82) resulted in significantly higher reduction of blood eosinophil and basophil levels in patients treated with benralizumab compared to mepolizumab. Mepolizumab did not significantly modified the levels of blood total IgE during the study period, whereas benralizumab significantly reduced (−35%, p < 0.001) total blood IgE levels. In patients treated with benralizumab the reduction of blood total Ig-E levels correlated with the reduction of blood basophils (but not eosinophils) and weakly with the improvement of asthma control. Conclusion: Benralizumab but not mepolizumab, treatment led to a significant reduction of circulating IgE level. The study provides different and specific mechanisms of action for anti-IL5-pathway treatments
The role of diet and exercise and of glucosamine sulfate in the prevention of knee osteoarthritis: Further results from the PRevention of knee Osteoarthritis in Overweight Females (PROOF) study
Background and objectives: The PRevention of knee Osteoarthritis in Overweight Females (PROOF) study (ISRCTN 42823086) described a trend for a decrease in the incidence of knee osteoarthritis (OA) by a tailored diet and exercise program (DEP) or by oral glucosamine sulfate in women at risk for the disease, using a composite clinical and/or radiological outcome. The aim of this updated post-hoc analysis was to re-assess the results according to more precise techniques and take advantage of the 2×2 factorial design. Methods: A total of 407 overweight (BMI ≥ 27 kg/m2) women of 50-60 years of age with no diagnosis of knee OA were randomized to: (1) no DEP + placebo (Control, N = 102), (2) DEP + placebo (DEP, N = 101), (3) glucosamine sulfate + no DEP (GS, N = 102), and (4) DEP + glucosamine sulfate (DEP + GS, N =102) and followed for 2.5 years, with standardized postero-anterior, semiflexed (MTP) view knee radiographs at baseline and end of the study. DEP consisted of a tailored low fat and/or low caloric diet and easy to implement physical activities. Glucosamine was given as oral crystalline glucosamine sulfate 1500 mg once daily, double-blinded vs. placebo. Incident knee OA was defined as radiographic progression of ≥1 mm minimum joint space narrowing (mJSN) in the medial tibiofemoral compartment, as previously assessed by the visual (manual) technique and by a new semi-automated method. Logistic regression analysis was used to calculate the odds ratio for the effect of the interventions. Results: After 2.5 years, 11.8% of control subjects developed knee OA. This incidence was decreased with glucosamine sulfate, either alone or in combination with the DEP, but not by the DEP alone. Since there was no statistical interaction between treatments, the 2×2 factorial design allowed analysis of patients receiving glucosamine sulfate (= 204) vs. those not receiving it (= 203), similarly for those on the DEP (= 203) or not (= 204). Glucosamine sulfate significantly decreased the risk of developing knee OA: odds ratio (OR) = 0.41 (95% CI: 0.20-0.85, P = 0.02) by the manual JSN assessment method and OR = 0.42 (95% CI: 0.20-0.92, P = 0.03) by the semi-automated technique. Conversely, there was no decrease in risk with the DEP. Conclusions: Glucosamine sulfate decreased the risk of developing radiographic knee OA over 2.5 years in overweight, middle-aged women at risk, as determined by medial mJSN progression. Conversely a tailored diet and exercise program exerted no preventive effect, possibly because of the lower than expected effect on weight loss
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