238 research outputs found
Critical Behavior in the Gravitational Collapse of a Scalar Field with Angular Momentum in Spherical Symmetry
We study the critical collapse of a massless scalar field with angular
momentum in spherical symmetry. In order to mimic the effects of angular
momentum we perform a sum of the stress-energy tensors for all the scalar
fields with the same eigenvalue, l, of the angular momentum operator and
calculate the equations of motion for the radial part of these scalar fields.
We have found that the critical solutions for different values of l are
discretely self-similar (as in the original l=0 case). The value of the
discrete, self-similar period, Delta_l, decreases as l increases in such a way
that the critical solution appears to become periodic in the limit. The mass
scaling exponent, gamma_l, also decreases with l.Comment: 10 pages, 8 figure
Atorvastatin combined to interferon to verify the efficacy (ACTIVE) in relapsing-remitting active multiple sclerosis patients: a longitudinal controlled trial of combination therapy.
A large body of evidence suggests that, besides their cholesterol-lowering effect, statins exert anti-inflammatory action. Consequently, statins may have therapeutic potential in immune-mediated disorders such as multiple sclerosis. Our objectives were to determine safety, tolerability and efficacy of low-dose atorvastatin plus high-dose interferon beta-1a in multiple sclerosis patients responding poorly to interferon beta-1a alone. Relapsingâremitting multiple sclerosis patients, aged 18â50 years, with contrast-enhanced lesions or relapses while on therapy with interferon beta-1a 44 mg (three times weekly) for 12 months, were randomized to combination therapy (interferon+atorvastatin 20mg per day; group A) or interferon alone (group B) for 24 months. Patients underwent blood analysis and clinical assessment with the Expanded Disability Status Scale every 3 months, and brain gadolinium-enhanced magnetic resonance imaging at screening, and 12 and 24 months thereafter. Primary outcome measure was contrast-enhanced lesion number. Secondary outcome measures were number of relapses, EDSS variation and safety laboratory data. Forty-five patients were randomized to group A (n 1â4 21) or B (n 1â4 24). At 24 months, group A had significantly fewer contrast-enhanced lesions versus baseline (p 1â4 0.007) and significantly fewer relapses versus the two pre-randomization years (p < 0.001). At survival analysis, the risk for a 1-point EDSS increase was slightly higher in group B than in group A (p 1â4 0.053). Low-dose atorvastatin may be beneficial, as add-on therapy, in poor responders to high-dose interferon beta-1a alone
Electronic nose and isotope ratio mass spectrometry in combination with chemometrics for the characterization of the geographical origin of Italian sweet cherries
Sweet cherries from two Italian regions, Apulia and Emilia Romagna, were analysed using electronic nose
(EN) and isotope ratio mass spectrometry (IRMS), with the aim of distinguishing them according to their
geographic origin. The data were elaborated by statistical techniques, examining the EN and IRMS datasets
both separately and in combination. Preliminary exploratory overviews were performed and then
linear discriminant analyses (LDA) were used for classification. Regarding EN, different approaches for
variable selection were tested, and the most suitable strategies were highlighted. The LDA classification
results were expressed in terms of recognition and prediction abilities and it was found that both EN and
IRMS performed well, with IRMS showing better cross-validated prediction ability (91.0%); the ENâIRMS
combination gave slightly better results (92.3%). In order to validate the final results, the models were
tested using an external set of samples with excellent results
Low-Protein Diets in Diabetic Chronic Kidney Disease (CKD) Patients: Are They Feasible and Worth the Effort?
Low-protein diets (LPDs) are often considered as contraindicated in diabetic patients, and are seldom studied. The aim of this observational study was to provide new data on this issue. It involved 149 diabetic and 300 non-diabetic patients who followed a LPD, with a personalized approach aimed at moderate protein restriction (0.6 g/day). Survival analysis was performed according to KaplanâMeier, and multivariate analysis with Cox model. Diabetic versus non-diabetic patients were of similar age (median 70 years) and creatinine levels at the start of the diet (2.78 mg/dL vs. 2.80 mg/dL). There was higher prevalence of nephrotic proteinuria in diabetic patients (27.52% vs. 13.67%, p = 0.002) as well as comorbidity (median Charlson index 8 vs. 6 p = 0.002). Patient survival was lower in diabetic patients, but differences levelled off considering only cases with Charlson index > 7, the only relevant covariate in Cox analysis. Dialysis-free survival was superimposable in the setting of good compliance (Mitch formula: 0.47 g/kg/day in both groups): about 50% of the cases remained dialysis-free 2 years after the first finding of e-GFR (estimated glomerular filtration rate) < 15 mL/min, and 1 year after reaching e-GFR < 10 mL/min. In patients with type 2 diabetes, higher proteinuria was associated with mortality and initiation of dialysis. In conclusion, moderately restricted LPDs allow similar results in diabetic and non non-diabetic patients with similar comorbidity
Polymorphic post-transplant lymphoproliferative disorder in a gilt
N.A. (case report, no abstract
Preliminary assessment of the mucosal toxicity of tea tree (Melaleuca alternifolia) and rosemary (rosmarinus officinalis) essential oils on novel porcine uterus models
Antimicrobial resistance, an ever-growing global crisis, is strongly linked to the swine production industry. In previous studies, Melaleuca alternifolia and Rosmarinus officinalis essential oils have been evaluated for toxicity on porcine spermatozoa and for antimicrobial capabilities in artificial insemination doses, with the future perspective of their use as antibiotic alternatives. The aim of the present research was to develop and validate in vitro and ex vivo models of porcine uterine mucosa for the evaluation of mucosal toxicity of essential oils. The in vitro model assessed the toxicity of a wider range of concentrations of both essential oils (from 0.2 to 500 mg/mL) on sections of uterine tissue, while the ex vivo model was achieved by filling the uterine horns. The damage induced by the oils was assessed by Evans Blue (EB) permeability assay and histologically. The expression of ZO-1, a protein involved in the composition of tight junctions, was assessed through immunohistochemical and immunofluorescence analysis. The results showed that low concentrations (0.2\u20130.4 mg/mL) of both essential oils, already identified as non-spermicidal but still antimicrobial, did not alter the structure and permeability of the swine uterine mucosa. Overall, these findings strengthen the hypothesis of a safe use of essential oils in inseminating doses of boar to replace antibiotics
Same-day discharge following catheter ablation of atrial fibrillation: A safe and cost-effective approach
Introduction:
The frequency of catheter ablation for atrial fibrillation (AF) has increased dramatically, stretching resources. Discharge on the same day as treatment may increase the efficiency and throughput. There are limited data regarding the safety of this strategy. /
Methods:
We performed a retrospective analysis of consecutive patients undergoing AF ablation in a tertiary center and in a district general hospital, and identified those discharged on the same day of treatment. The safety endpoint was any complication and/or presentation to hospital in the 48âh and at 30 days postdischarge. We performed an economic analysis to calculate potential cost saving. /
Results:
Among a total population of 2628 patients, we identified 727 subjects (61.1â±â12.5 years, 69.6% male) undergoing dayâcase AF ablation. Cryoballoon technique was used in 79.2% of the dayâcases, and 91.6% of the procedures were performed under conscious sedation. 1.8% (13) of the participants met the safety composite endpoint at 48âh, however only 0.7% (5) required at least 1 day of hospitalization. Bleeding or hematoma at the femoral access site (0.5%) and pericarditic chest pain (0.5%) were the main reasons for readmission. None experienced cardiac tamponade or other lifeâthreatening complications in the 48âh postdischarge. Overall rate of complication and/or presentation to hospital at 30 days was 3.7%. Our dayâcase policy resulted in an annual costâsaving of approximately of ÂŁ83â927 for our hospital. /
Conclusion:
In this large multicentre cohort, sameâday discharge in selected patients following AF ablation appears to be safe and costâeffective, with a very low rate of early readmission or postâdischarge complication
Development of a pig mammary epithelial cell culture model as a nonâclinical tool for studying epithelial barrierâ a contribution from the imiâconception project
The ConcePTION project aims at generating further knowledge about the risks related to the use of medication during breastfeeding, as this information is lacking for most commonly used drugs. Taking into consideration multiple aspects, the pig model has been considered by the consortium as the most appropriate choice. The present research was planned to develop an efficient method for the isolation and culture of porcine Mammary Epithelial Cells (pMECs) to study the mammary epithelial barrier in vitro. Mammary gland tissues were collected at a local slaughterhouse, dissociated and the selected cellular population was cultured, expanded and characterized by morphology, cell cycle analysis and immunophenotyping. Their ability to create a barrier was tested by TEER measurement and sodium fluorescein transport activity. Expression of 84 genes related to drug transporters was evaluated by a PCR array. Our results show that primary cells express epithelial cell markers: CKs, CK18, EâCad and tight junctions molecules ZOâ1 and OCL. All the three pMEC cellular lines were able to create a tight barrier, although with different strengths and kinetics, and express the main ABC and SLC drug transporters. In conclusion, in the present paper we have reported an efficient method to obtain primary pMEC lines to study epithelial barrier function in the pig model
Biocompatibility of a Conjugated Polymer Retinal Prosthesis in the Domestic Pig
The progressive degeneration of retinal photoreceptors is one of the most significant causes of blindness in humans. Conjugated polymers represent an attractive solution to the field of retinal prostheses, and a multi-layer fully organic prosthesis implanted subretinally in dystrophic Royal College of Surgeons (RCS) rats was able to rescue visual functions. As a step toward human translation, we report here the fabrication and in vivo testing of a similar device engineered to adapt to the human-like size of the eye of the domestic pig, an excellent animal paradigm to test therapeutic strategies for photoreceptors degeneration. The active conjugated polymers were layered onto two distinct passive substrates, namely electro-spun silk fibroin (ESF) and polyethylene terephthalate (PET). Naive pigs were implanted subretinally with the active device in one eye, while the contralateral eye was sham implanted with substrate only. Retinal morphology and functionality were assessed before and after surgery by means of in vivo optical coherence tomography and full-field electroretinogram (ff-ERG) analysis. After the sacrifice, the retina morphology and inflammatory markers were analyzed by immunohistochemistry of the excised retinas. Surprisingly, ESF-based prostheses caused a proliferative vitreoretinopathy with disappearance of the ff-ERG b-wave in the implanted eyes. In contrast, PET-based active devices did not evoke significant inflammatory responses. As expected, the subretinal implantation of both PET only and the PET-based prosthesis locally decreased the thickness of the outer nuclear layer due to local photoreceptor loss. However, while the implantation of the PET only substrate decreased the ff-ERG b-wave amplitude with respect to the pre-implant ERG, the eyes implanted with the active device fully preserved the ERG responses, indicating an active compensation of the surgery-induced photoreceptor loss. Our findings highlight the possibility of developing a new generation of conjugated polymer/PET-based prosthetic devices that are highly biocompatible and potentially suitable for subretinal implantation in patients suffering from degenerative blindnes
- âŠ