227 research outputs found
COL2A1 gene mutations: mechanisms of spondyloepiphyseal dysplasia congenita
The COL2A1 gene consists of 54 exons spanning over 31.5 kb and encodes for type II collagen. Type II collagen is the main component of hyaline cartilage extracellular matrix, nucleus pulposus of intervertebral discus, vitreous humor of the eye and inner ear structure. Molecular defects in COL2A1 gene cause a wide variety of rare autosomal-dominant conditions known as type II collagenopathies. A clear genotype–phenotype relationship is not yet known. However, some correlations are described. Spondyloephyseal dysplasia congenita was suggested for a short-trunk dwarfing condition affecting primarily the vertebrae and the proximal epiphyses of the long bones
Functional polymeric coatings for csi(Tl) scintillators
The handling of inorganic scintillators (e.g., alkali metal halides) can benefit from the availability of polymeric materials able to adhere to their surface. Polymeric materials, such as epoxy resins, can act as protective coatings, as adhesives for photodiodes to be connected with the scintillator surface, and as a matrix for functional fillers to improve the optical properties of scintillators. Here, the optical properties of two epoxy resins (E-30 by Prochima, and Technovit Epox by Heraeus Kulzer) deposited on the surface of a scintillator crystal made of CsI(Tl) were investigated, in order to improve the detection of high-energy radiation. It is found that these resins are capable of adhering to the surface of alkali metal halides. Adhesion, active at the epoxy–CsI(Tl) interface, can be explained on the basis of Coulomb forces acting between the ionic solid surface and an ionic intermediate of synthesis generated during the epoxy setting reaction. Technovit Epox showed higher transparency, and it was also functionalized by embedding white powdered pigments (PTFE or BaSO4) to achieve an optically reflective coating on the scintillator surface
Age limit in bronchiolitis diagnosis: 6 or 12 months?
Aim: The most frequent cause of lower respiratory tract infection in infants is bronchiolitis. Up to now there is no agreement on the upper limit age of bronchiolitis. Our aim was to identify if there are clinical differences in infants hospitalized for bronchiolitis between 0–6 months and 6–12 months of age. A secondary aim was to establish whether there was differences in terms of recurrent wheezing at 12, 24, and 36 months of follow-up. Methods: We retrospectively analyzed clinical and virological records of 824 infants hospitalized for bronchiolitis during 11 consecutive epidemic seasons. From each infant at admission to the hospital nasopharyngeal washing was collected, clinical severity was assessed and clinical data were extracted from a structured questionnaire. At 12–24–36 months after discharge, parents were interviewed seeking information on recurrent wheezing. Results: A total of 773 infants (Group1) were ≤6 months of age, while 51 were >6 months (Group 2). No differences between family history for atopy and passive smoking exposure were observed between the two groups. Respiratory syncyzial virus was detected more frequently in Group 1 and human bocavirus in Group 2. The clinical severity score (p = 0.011) and the use of intravenous fluids (p = 0.0001) were higher in Group 1 with respect to Group 2 infants. At 36 months follow-up 163/106 (39.4%) Group 1 and 9/9 Group 2 infants experienced recurrent wheezing (p = 0.149). Conclusion: We demonstrated that 0-6 months old infants bronchiolitis differs from > 6 months bronchiolitis
During the COVID-19 pandemic where has respiratory syncytial virus gone?
The diffusion of the SARS-CoV-2 virus and the implementation of restrictive measures led to a drastic reduction of respiratory syncytial virus (RSV) diffusion. Few RSV cases have been detected worldwide, even after the removal of the restrictions. We review the current literature and present possible explanations on why there has been a significant reduction of RSV detection during the COVID-19 pandemic. We also hypothesize what may happen when RSV begins to circulate again. The increase of an immunologically naĂŻve population, with infants born from mothers who have not reinforced their immunity to RSV, could lead to greater RSV epidemics in the coming seasons. It is crucial to prepare the scientific community and to keep RSV surveillance active to avoid dramatic consequences
Optical properties of polystyrene-ZnO nanocomposite scattering layer to improve light extraction in organic light-emitting diode
In this work, experimental measurements on polystyrene-ZnO nanocomposite scattering films and on organic light-emitting device with and without the scattering layers are presented. The results are also compared with Henyey-Greenstein radiative-transfer model to narrow down the parameters that can be important in the identification of more suitable scattering layers. As a result, an increase of efficiency of about 30% has been obtained that it can be translated in 60% of outcoupled light in respect to the total generated amount
Protection against pertussis in humans correlates to elevated serum antibodies and memory B cells
Pertussis is a respiratory infection caused by Bordetella pertussis that may be particularly severe and even lethal in the first months of life when infants are still too young to be vaccinated. Adults and adolescents experience mild symptoms and are the source of infection for neonates. Adoptive maternal immunity does not prevent pertussis in the neonate. We compared the specific immune response of mothers of neonates diagnosed with pertussis and mothers of control children. We show that women have pre-existing pertussis-specific antibodies and memory B cells and react against the infection with a recall response increasing the levels specific serum IgG, milk IgA, and the frequency of memory B cells of all isotypes. Thus, the maternal immune system is activated in response to pertussis and effectively prevents the disease indicating that the low levels of pre-formed serum antibodies are insufficient for protection. For this reason, memory B cells play a major role in the adult defense. The results of this study suggest that new strategies for vaccine design should aim at increasing long-lived plasma cells and their antibodies
Simulating the ideal geometrical and biomechanical parameters of the pulmonary autograft to prevent failure in the Ross operation
OBJECTIVES: Reinforcements for the pulmonary autograft (PA) in the Ross operation have been introduced to avoid the drawback of conduit
expansion and failure. With the aid of an in silico simulation, the biomechanical boundaries applied to a healthy PA during the operation
were studied to tailor the best implant technique to prevent reoperation.
METHODS: Follow-up echocardiograms of 66 Ross procedures were reviewed. Changes in the dimensions and geometry of reinforced
and non-reinforced PAs were evaluated. Miniroot and subcoronary implantation techniques were used in this series. Mechanical stress
tests were performed on 36 human pulmonary and aortic roots explanted from donor hearts. Finite element analysis was applied to obtain
high-fidelity simulation under static and dynamic conditions of the biomechanical properties and applied stresses on the PA root and leaflet
and the similar components of the native aorta.
RESULTS: The non-reinforced group showed increases in the percentages of the mean diameter that were significantly higher than those
in the reinforced group at the level of the Valsalva sinuses (3.9%) and the annulus (12.1%). The mechanical simulation confirmed geometrical
and dimensional changes detected by clinical imaging and demonstrated the non-linear biomechanical behaviour of the PA anastomosed
to the aorta, a stiffer behaviour of the aortic root in relation to the PA and similar qualitative and quantitative behaviours of leaflets
of the 2 tissues. The annulus was the most significant constraint to dilation and affected the distribution of stress and strain within the entire
complex, with particular strain on the sutured regions. The PA was able to evenly absorb mechanical stresses but was less adaptable to
circumferential stresses, potentially explaining its known dilatation tendency over time.
CONCLUSIONS: The absence of reinforcement leads to a more marked increase in the diameter of the PA. Preservation of the native geometry
of the PA root is crucial; the miniroot technique with external reinforcement is the most suitable strategy in this context
Implantation of a Poly-L-Lactide GCSF-Functionalized Scaffold in a Model of Chronic Myocardial Infarction
A previously developed poly-L-lactide scaffold re-
leasing granulocyte colony-stimulating factor (PLLA/GCSF)
was tested in a rabbit chronic model of myocardial infarction
(MI) as a ventricular patch. Control groups were constituted by
healthy, chronic MI and nonfunctionalized PLLA scaffold.
PLLA-based electrospun scaffold efficiently integrated into a
chronic infarcted myocardium. Functionalization of the bio-
polymer with GCSF led to increased fibroblast-like vimentin-
positive cellular colonization and reduced inflammatory cell
infiltration within the micrometric fiber mesh in comparison to
nonfunctionalized scaffold; PLLA/GCSF polymer induced an
angiogenetic process with a statistically significant increase in
the number of neovessels compared to the nonfunctionalized
scaffold; PLLA/GCSF implanted at the infarcted zone induced
a reorganization of the ECM architecture leading to connective
tissue deposition and scar remodeling. These findings were
coupled with a reduction in end-systolic and end-diastolic vol-
umes, indicating a preventive effect of the scaffold on ventricu-
lar dilation, and an improvement in cardiac performance
Covid-19 lockdown impacts among patients with cystic fibrosis. an italian regional reference centre experience
Background: Coronavirus pandemic has influenced our society with social distancing and management of chronic disease such as cystic fibrosis (CF). During the Italian lockdown from March to May 2020, CF patients reduced the number of outpatient visits, limited social interactions and spent more time at home. The aim of this study is to evaluate the impact of the lockdown on body mass index (BMI) and lung function tests on CF patients. Methods: We retrospectively reviewed clinical data about 111 CF patients followed in our Regional Cystic Fibrosis Reference Centre (Policlinico Umberto I, Rome) according to two periods: pre-lockdown (from October 2019-March 2020) and post-lockdown (from May 2020-October 2020). We collected data on nutritional (BMI and body weight) and lung function status; we chose the best values of the 'pre-lockdown' and 'post-lockdown' period for each patient. Patients were divided into 3 groups according to FEV1 value (Forced Expiratory Volume in the 1st second): group 1 (FEV1 <40%), group 2 (FEV1 40-70%), group 3 (FEV1 >70%). All patients received a telephone interview asking for the number of hours per week devoted to physical activity, number of pulmonary acute exacerbations and subjective evaluation of adherence to medical therapy, respiratory physiotherapy and diet, during the two periods. Results: Comparing weight, BMI and respiratory function between pre and post lockdown periods, we noticed an increase in weight during among overall patients. Male patients improved weight, BMI, FEF 25-75% (Forced Expiratory flow between 25% and 75% of vital capacity) and Tiffenau index more than female patients. The most severely compromised patients (group 1), showed a significant loss of both weight and BMI. Instead, patients with moderate respiratory function (group 2) showed a significant increase of both weight and BMI and a slightly reduced CVF (Forced Vital capacity). We found no differences among patients with good respiratory function (group 3). Comparing each clinical sub-groups, we noticed a significative improvement of weight (p = 0.018) and BMI (p = 0.030) among patients with moderate respiratory function compared to patients with compromised respiratory function. During lockdown, patients reported less physical activity, no variation in food amount and composition, more adherence to therapy (43%) and more consistent daily respiratory physiotherapy (47.6%). Conclusions: Lockdown period had benefit among CF patients in terms of weight in particular in male patient. The greatest benefit on nutritional state was observed in patients with moderate reduction of respiratory function. In addition, we noted a stabilization and sometimes a slight improvement of lung function, instead of a continuous and steady decline that is normally observed in CF patients. These beneficial effects are slight but significative, bearing in mind the general worsening that CF patients experience annually
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