8,168 research outputs found
Quantum phase excitations in Ginzburg-Landau superconductors
We give a straightforward generalization of the Ginzburg-Landau theory for
superconductors where the scalar phase field is replaced by an antisymmetric
Kalb-Ramond field. We predict that at very low temperatures, where quantum
phase effects are expected to play a significant role, the presence of vortices
destroys superconductivity.Comment: revtex, 4 pages, no figure
Treatment of esophageal achalasia in children: Today and tomorrow
Esophageal achalasia (EA) is a rare esophageal motility disorder in children. Laparoscopic Heller myotomy (LHM) represents the treatment of choice in young patients. Peroral endoscopic myotomy (POEM) is becoming an alternative to LHM. The aim of this study is to evaluate the effectiveness, safety, and outcomes of POEM vs LHM in treatment of children with EA.
Data of pediatric patients with EA, who underwent LHM and POEM from February 2009 to December 2013 in two centers, were collected.
Eighteen patients (9 male, mean age: 11.6 years; range: 2-17 years) were included. Nine patients (6 male, mean age: 10.7 years; range: 2-16 years) underwent LHM, and the other 9 (3 males, mean age: 12.2 years; range: 6-17 years) underwent POEM procedure. Mean operation time was shorter in POEM group compared with LHM group (62/149 minutes). Myotomy was longer in POEM group than in LHM group (11/7 cm). One major complication occurred after LHM (esophageal perforation). No clinical and manometric differences were observed between LHM and POEM in follow-up. The incidence of iatrogenic gastroesophageal reflux disease was low (1 patient in both groups).
Results of a midterm follow-up show that LHM and POEM are safe and effective treatments also in children. Besides, POEM is a mini-invasive technique with an inferior execution timing compared to LHM. A skilled endoscopic team is mandatory to perform this procedur
TIBIO-FIBULAR BONE TRANSPOSITION FOR THE TREATMENT OF ONCOLOGICAL PERIPROSTHETIC INFECTION OF THE KNEE WITH MASSIVE BONE LOSS
Chronic periprosthetic joint infection (PJI) is one of the most relevant complications in orthopaedic
surgery, especially in the case of limb reconstruction with megaprostheses after malignant tumoral
resection. This is the report of a case of a 35-year-old patient, affected by a chronic PJI around a
knee megaprosthesis implanted after the resection of an osteosarcoma of the distal femur. “En bloc”
resection and limb reconstruction with an expandable megaprothesis of the knee were performed at
the age of 5 years old (1989). PJI occurred after the definitive megaprosthesis implantation (2002),
and became chronic over the years.
In 2019, due to a massive recrudescence of the infection and the severe femoral bone loss, the
patient underwent a wide intercalary resection and a thigh stump reconstruction by transposition of
the fibula and the distal third of the tibia in order to avoid a hip disarticulation.
Although complex, the proposed treatment allowed improved outcomes in a young patient with
high function requests, justifying the global surgical invasiveness
Anterior gradient protein 2 promotes survival, migration and invasion of papillary thyroid carcinoma cells
Through a transcriptome microarray analysis, we have isolated Anterior gradient protein 2 (AGR2) as a gene up-regulated in papillary thyroid carcinoma (PTC). AGR2 is a disulfide isomerase over-expressed in several human carcinomas and recently linked to endoplasmic reticulum (ER) stress. Here, we analyzed the expression of AGR2 in PTC and its functional role
Hepatic steatosis and insulin resistance are associated with severe fibrosis in patients with chronic hepatitis caused by HBV or HCV infection.
BACKGROUND AND AIMS: Steatosis and insulin resistance (IR) are the major disease modifying in patients with chronic hepatitis C (CHC). Only few studies evaluated these features in patients with chronic hepatitis B (CHB). We aimed to assess the prevalence and the factors related to steatosis and IR in CHB patients, compared with CHC subjects, and to evaluate the potential association between these features and fibrosis severity.
MATERIAL AND METHODS: One hundred and seventy consecutive patients with CHB (28 HBeAg positive, 142 HBeAg negative), were evaluated using liver biopsy and metabolic measurements and matched for sex, age and body mass index with 170 genotype 1 CHC patients. IR was defined if HOMA-IR>2.7. All biopsies were scored for grading and staging by Scheuer's score, and the steatosis was considered significant if ≥ 10%.
RESULTS: The prevalence of significant steatosis was similar in both CHB and CHC patients (31 vs. 38%; P=0.14). IR rate was significantly higher in CHC than in CHB patients (42 vs. 26%; P=0.002). Severe fibrosis (F3-F4), at multivariate analysis, was independently associated with older age (OR 1.050, 95% CI 1.009-1.093), steatosis >10% (OR 4.375, 95% CI 1.749-10.943), and moderate-severe necroinflammatory activity (OR 8.187, 95% CI 2.103-31.875), regardless of HBeAg status, in CHB patients, and with older age (OR 1.080, 95% CI 1.028-1.136), IR (OR 2.640, 95% CI 1.110-6.281), steatosis >10% (OR 3.375, 95% CI 1.394-8.171), and moderate-severe necroinflammatory activity (OR 8.988, 95% CI 1.853-43.593) in CHC patients.
CONCLUSIONS: CHB patients had high steatosis prevalence, similar to CHC controls, but lower IR rate. Both steatosis and IR in CHC, and only steatosis in CHB, are independently associated with fibrosis severity
Proteomic study of muscle sarcoplasmic proteins using AUT-PAGE/SDS-PAGE as two-dimensional gel electrophoresis
The conversion of muscle to meat in pig involves mainly proteolysis of myofibrillar proteins, which undergo notable changes since early stage of rigor mortis, even after 48 h post mortem. The tenderness of meat has been thoroughly investigated to understand the biochemical mechanisms, which influence texture and flavour development as well as the technological parameters and hence meat quality. Cytoplasmic proteolytic calcium dependent enzymes, named -and m-calpains, which act in the early stages of rigor mortis, significantly contribute to tenderization weakening myofibrils. These enzymes, however, act for fewdays because they are specifically inhibited by calpastatin and by pH lowering. However, when pH falls to about 5.0, proteolytic activity on muscle proteins is continued by longer acting lysosomal proteinase, cathepsins [3,7–9]. Post mortem proteolysis also causes relevant changes in sarcoplamic protein fraction, which represent the water soluble fraction (quantitatively about 30–35%) of meat total protein, and the involved proteins has already been identified by proteomic-based studies. Recent investigations have demonstrated that the most commonly found Lactobacillus species in dry fermented meats are able to hydrolyse myofibrillar and sarcoplasmic muscle proteins in vitro.The most abundant sarcoplasmic proteins, as mixture of basic polypeptides with a narrow spread range of molecular masses, represented an excellent model to test our analytical technique and to delineate its capabilities. In the present study, we compared 2D AUT-PAGE/SDSPAGE maps of water-soluble proteins extracted from fresh meat and from dry-cured ham, a non fermented product, from “Naples-type” salami, a microbiologically fermented product, and from “Coppa”, a typical semi-fermented product. Electrophoretically separated proteins have been identified by MALDI-ToF mass fingerprinting
Charged particle's flux measurement from PMMA irradiated by 80 MeV/u carbon ion beam
Hadrontherapy is an emerging technique in cancer therapy that uses beams of
charged particles. To meet the improved capability of hadrontherapy in matching
the dose release with the cancer position, new dose monitoring techniques need
to be developed and introduced into clinical use. The measurement of the fluxes
of the secondary particles produced by the hadron beam is of fundamental
importance in the design of any dose monitoring device and is eagerly needed to
tune Monte Carlo simulations. We report the measurements done with charged
secondary particles produced from the interaction of a 80 MeV/u fully stripped
carbon ion beam at the INFN Laboratori Nazionali del Sud, Catania, with a
Poly-methyl methacrylate target. Charged secondary particles, produced at
90 with respect to the beam axis, have been tracked with a drift
chamber, while their energy and time of flight has been measured by means of a
LYSO scintillator. Secondary protons have been identified exploiting the energy
and time of flight information, and their emission region has been
reconstructed backtracking from the drift chamber to the target. Moreover a
position scan of the target indicates that the reconstructed emission region
follows the movement of the expected Bragg peak position. Exploting the
reconstruction of the emission region, an accuracy on the Bragg peak
determination in the submillimeter range has been obtained. The measured
differential production rate for protons produced with 83 MeV and emitted at 90 with respect to the beam line is: .Comment: 13 pages, 9 figure
An evaluation of coronary atherosclerosis using coronary CT in subjects with asymptomatic carotid lesions.
The evaluation of coronary lesions in patients with asymptomatic carotid plaque represents a very promising line of research to assess cardiovascular risk and the possible implementation of a more aggressive prevention therapy.
METHODS:
In this study we enrolled 102 patients with intermediate to high cardiovascular risk but no history of coronary artery disease. The first group, consisting of 51 patients, underwent a Coronary CT scan (CCT-group) as well as carotid ultrasonography. The second group, also consisting of 51 patients, underwent coronary angiography (CA) and carotid ultrasonography.
RESULTS:
The absence of a statistically significant difference between the involvement of both coronary and carotid sites, assessed by CCT and CA, confirms the role of coronary CT as a useful method in the preclinical evaluation of cardiovascular risk. In the CCT group, the correlation between atherosclerosis of carotid artery and coronary disease, as well as between the mean carotid intimal medial thickness and the number of involved coronary vessels, and between the maximum values of carotid plaque and the presence of coronary artery stenosis > 50%, were statistically significant. The Agatson calcium score was also statistically associated with carotid plaque size.
CONCLUSION:
The imaging biomarkers have a key role in the evaluation of subclinical atherosclerotic disease. Moreover, carotid ultrasound examination and a CT-scan of coronary arteries, in a particular sub-group of patients with intermediate to high cardiovascular risk, can play a crucial role to assess the preventive therapeutic strategies
An Overview of the Cardiorenal Protective Mechanisms of SGLT2 Inhibitors
Sodium-glucose co-transporter 2 (SGLT2) inhibitors block glucose reabsorption in the renal proximal tubule, an insulin-independent mechanism that plays a critical role in glycemic regulation in diabetes. In addition to their glucose-lowering effects, SGLT2 inhibitors prevent both renal damage and the onset of chronic kidney disease and cardiovascular events, in particular heart failure with both reduced and preserved ejection fraction. These unexpected benefits prompted changes in treatment guidelines and scientific interest in the underlying mechanisms. Aside from the target effects of SGLT2 inhibition, a wide spectrum of beneficial actions is described for the kidney and the heart, even though the cardiac tissue does not express SGLT2 channels. Correction of cardiorenal risk factors, metabolic adjustments ameliorating myocardial substrate utilization, and optimization of ventricular loading conditions through effects on diuresis, natriuresis, and vascular function appear to be the main underlying mechanisms for the observed cardiorenal protection. Additional clinical advantages associated with using SGLT2 inhibitors are antifibrotic effects due to correction of inflammation and oxidative stress, modulation of mitochondrial function, and autophagy. Much research is required to understand the numerous and complex pathways involved in SGLT2 inhibition. This review summarizes the current known mechanisms of SGLT2-mediated cardiorenal protection
Measurement of the neutron detection efficiency of a 80% absorber - 20% scintillating fibers calorimeter
The neutron detection efficiency of a sampling calorimeter made of 1 mm
diameter scintillating fibers embedded in a lead/bismuth structure has been
measured at the neutron beam of the The Svedberg Laboratory at Uppsala. A
significant enhancement of the detection efficiency with respect to a bulk
organic scintillator detector with the same thickness is observed.Comment: 10 pages, 7 figure
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