29 research outputs found

    Parity-Violating Electron Scattering from 4He and the Strange Electric Form Factor of the Nucleon

    Full text link
    We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from ^4He at an average scattering angle = 5.7 degrees and a four-momentum transfer Q^2 = 0.091 GeV^2. From these data, for the first time, the strange electric form factor of the nucleon G^s_E can be isolated. The measured asymmetry of A_PV = (6.72 +/- 0.84 (stat) +/- 0.21 (syst) parts per million yields a value of G^s_E = -0.038 +/- 0.042 (stat) +/- 0.010 (syst), consistent with zero

    Constraints on the Nucleon Strange Form Factors at Q^2 ~ 0.1 GeV^2

    Get PDF
    We report the most precise measurement to date of a parity-violating asymmetry in elastic electron-proton scattering. The measurement was carried out with a beam energy of 3.03 GeV and a scattering angle =6 degrees, with the result A_PV = -1.14 +/- 0.24 (stat) +/- 0.06 (syst) parts per million. From this we extract, at Q^2 = 0.099 GeV^2, the strange form factor combination G_E^s + 0.080 G_M^s = 0.030 +/- 0.025 (stat) +/- 0.006 (syst) +/- 0.012 (FF) where the first two errors are experimental and the last error is due to the uncertainty in the neutron electromagnetic form factor. This result significantly improves current knowledge of G_E^s and G_M^s at Q^2 ~0.1 GeV^2. A consistent picture emerges when several measurements at about the same Q^2 value are combined: G_E^s is consistent with zero while G_M^s prefers positive values though G_E^s=G_M^s=0 is compatible with the data at 95% C.L.Comment: minor wording changes for clarity, updated references, dropped one figure to improve focu

    Colecistite acuta acalcolotica in corso di epatite A : 2 casi pediatrici

    No full text
    Acute acalculous cholecystitis (CAA) is very rare in children and it is usually related to infectious agents. We report 2 paediatric cases of CAA complicating hepatitis type A, with a favourable evolution with conservative treatment

    Epatite A ad evoluzione atipica

    No full text
    Hepatitis A virus infection is usually asymptomatic in children. Classic symptomatic forms and atypical clinical manifestations are known. We report a paediatric case of hepatitis A with marked cholestasis, treated with steroids, and with an unusual prolonged course

    Genetic Variants Assessing Crohn’s Disease Pattern in Pediatric Inflammatory Bowel Disease Patients by a Clinical Exome Survey

    No full text
    Background: Inflammatory bowel diseases (IBDs) are complex, multifactorial disorders that comprise Crohn’s disease (CD) and ulcerative colitis (UC). Recent discoveries have brought much attention to the genetic predisposition of patients with IBD. Here we evaluate the interaction between IBD genetic risk factors susceptibility and CD occurrence in an IBD pediatric patient population, performing a clinical exome survey. Methods: From February 2018 to April 2019, we collected blood samples from 7 pediatric patients with IBD concerns from several collaborating health centers and/or hospitals. Blood samples were processed by extracting and sequencing DNA for a clinical exome survey. Shophia-DDM-v3-4 platform allowed sequenced reads alignment on hg19 genome as well as genetic variant calling. Both IBD risk and pathogenic genetic variants covered by at least 20 reads were selected for subjacent analysis. Results: Normality and Bartlett tests of both risk and pathogenic genetic variants suggested random and heterogeneous distribution of these variants in this group of IBD pediatric patients. P value clustering analysis by processing 157 IBD risk factors revealed genetic heterogeneity in IBD population and suggested two pathways influencing IBD development. In particular, (1) genetic variants associated with autoimmune and (2) metabolic diseases and CD risk factors (rs2066844 and rs2241880 single nucleotide polymorphism variants, respectively, of genes NOD2 and ATG16L) were identified in distinct clusters of IBD patients (P <.05). Moreover, the heterogeneous distribution of the following variants rs10065172 (IRGM), rs1805010 (IL4R), rs5030737 (MBL2), and rs33995883 (LRRK2) in this group of IBD patients was consistent with their random distribution in that population. Conclusion: Our study revealed specific genetic variants linked to CD susceptibility, autoimmune and/or innate immunodeficiency as well as to metabolic defects, as favoring factors of IBD, suggesting the valuable role of next generation sequencing (NGS) approaches in IBD molecular diagnostic procedures

    Low mean impedance in 24-hour tracings and esophagitis in children: a strong connection

    No full text
    Esophageal multiple intraluminal impedance baseline is an additional impedance parameter that was recently related to esophageal integrity. The aim of this study was to assess the relationship between mean esophageal impedance value and endoscopic findings in a large group of children. Children with symptoms of gastroesophageal reflux submitted to both endoscopy and impedance were included. Esophagitis was graded according to the Los Angeles classification. Mean impedance value was automatically calculated over 24-hour tracings. Data were adjusted for age through z-score transformation using percentiles normalized by the LMS (Lambda for the skew, Mu for the median, and Sigma for the generalized coefficient of variation) method. Nonparametric Mann-Whitney and Kruskal-Wallis tests, multiple, and stepwise regression were used. P-value <0.05 was considered as statistically significant. A total of 298 impedance tracings were analyzed. Endoscopic and histological esophagitis were detected in 30 and 29% patients, respectively. Median baseline z-score was significantly decreased both in proximal (P = 0.02) and distal (P = 0.01) esophagus in patients with endoscopic (but not histological) esophagitis. Patients with more severe esophagitis showed the lowest z-score. Bolus exposure index and the number of reflux episodes were the variables that were significantly associated with the baseline z-score. Impedance z-score is significantly decreased in infants and children with endoscopic esophagitis. Severity of esophagitis, bolus exposure index, and number of reflux episodes are factors influencing mean esophageal impedance

    Alpha1-antitrypsin deficiency: a twenty-five years' experience.

    No full text
    Purpose Analyze the natural history of AATD subjects identified during the twenty-five years’ experience of the Referral Center of Spedali Civili, Brescia (Italy). Methods Retrospective clinical analysis of patients referred to our Center since January 1996 up to January 2020. The inclusion criterion was a diagnosis of AATD via genotyping or protein phenotyping. Results 1021 patients were included (53% males). At the time of diagnosis, mean AAT serum level was 79±27 mg/dL. We diagnosed 825 simple heterozygotes (genotype PiMZ 65%), 117 compound heterozygotes (genotype PiSZ 54%) and 79 homozygotes (genotype PiZZ 82%); 151 (15%) patients were carriers of rare variants, especially Mmalton (35). Index cases (diagnosed due to diseases correlated with AATD) were 223 (22%), 70 of them suffered from emphysema. Among non-index cases, family history for AATD was the most common cause of diagnosis (70%). Augmentation therapy was prescribed in 38 patients; no adverse drug reactions were observed. FEV1 annual decline (mL/year) and the annual trend of blood transaminases have been evaluated. Conclusions Z-AAT resulted the most common variant, although many rarer ones are present. Experienced Referral Centers are crucial for AATD correct management and to carry out a timely diagnosis. Our final data regarding natural history of AATD will let clinicians better understand the prognosis of AATD, supporting them to make the better medical decision. Clinical implications This research increases the knowledge on AATD natural history and its optimal management
    corecore