Transient elastography for non‐invasive evaluation of post‐transplant liver graft fibrosis in children

As graft survival in pediatric LT is often affected by progressive fibrosis, numerous centers carry out protocol liver biopsies. Follow‐up biopsy protocols differ from center to center, but all biopsies are progressively spaced out, as time from transplant increases. Therefore, there is a need for non‐invasive techniques to evaluate graft fibrosis progression in those children who have no clinical or serological signs of liver damage. Indirect markers, such as the APRI, should be relied on with caution because their sensitivity in predicting fibrosis can be strongly influenced by the etiology of liver disease, severity of fibrosis, and patient age. A valid alternative could be TE, a non‐invasive technique already validated in adults, which estimates the stiffness of the cylindrical volume of liver tissue, 100‐fold the size of a standard needle biopsy sample. The aims of this study were to evaluate the reliability of TE in children after LT and to compare both the TE and the APRI index results with the histological scores of fibrosis on liver biopsies. A total of 36 pediatric LT recipients were studied. All patients underwent both TE and biopsy within a year (median interval ‐0.012 months) at an interval from LT of 0.36 to 19.47 years (median 3.02 years). Fibrosis was assessed on the biopsy specimens at histology and staged according to METAVIR. There was a statistically significant correlation between TE stiffness values and METAVIR scores (P = .005). The diagnostic accuracy of TE for the diagnosis of significant fibrosis (F ≥ 2) was measured as the area under the curve (AUROC = 0.865), and it demonstrated that the method had a good diagnostic performance. APRI was not so accurate in assessing graft fibrosis when compared to METAVIR (AUROC = 0.592). A liver stiffness cutoff value of 5.6 kPa at TE was identified as the best predictor for a significant graft fibrosis (METAVIR F ≥ 2) on liver biopsy, with a 75% sensitivity, a 95.8% specificity, a 90% positive predictive value, and an 88.5% negative predictive value. These data suggest that TE may represent a non‐invasive, reliable tool for the assessment of graft fibrosis in the follow‐up of LT children, alerting the clinicians to the indication for a liver biopsy, with the aim of reducing the number of protocol liver biopsies.     

Biomechanical Behavior of Narrow Dental Implants Made with Aluminum- and Vanadium-Free Alloys: A Finite Element Analysis

Titanium (Ti) alloys used for narrow dental implants usually contain aluminum (Al) and vanadium (V) for improved resistance. However, those elements are linked to possible cytotoxic effects. Thus, this study evaluated the biomechanical behavior of narrow dental implants made with Al- and V-free Ti alloys by the finite element method. A virtual model of a partially edentulous maxilla received single implants (diameter: 2.7 and 2.9 mm; length: 10 mm) at the upper lateral incisor area, with respective abutments and porcelain-fused-to-metal crowns. Simulations were performed for each implant diameter and the following eight alloys (and elastic moduli): (1) Ti–6Al–4V (control; 110 GPa), (2) Ti–35Nb–5Sn–6Mo–3Zr (85 GPa), (3) Ti–13Nb–13Zr (77 GPa), (4) Ti–15Zr (113 GPa), (5) Ti–8Fe–5Ta (120 GPa), (6) Ti–26.88Fe–4Ta (175 GPa), (7) TNTZ–2Fe–0.4O (107 GPa), and (8) TNTZ–2Fe–0.7O (109 GPa). The implants received a labially directed total static load of 100 N at a 45° angle relative to their long axis. Parameters for analysis included the maximum and minimum principal stresses for bone, and von Mises equivalent stress for implants and abutments. Ti–26.88Fe–4Ta reaches the lowest maximum (57 MPa) and minimum (125 MPa) principal stress values, whereas Ti–35Nb–5Sn–6Mo–3Zr (183 MPa) and Ti–13Nb–13Zr (191 MPa) models result in the highest principal stresses (the 2.7 mm model surpasses the threshold for bone overload). Implant diameters affect von Mises stresses more than the constituent alloys. It can be concluded that the narrow implants made of the Ti–26.88Fe–4Ta alloy have the most favorable biomechanical behavior, mostly by mitigating stress on peri-implant bone.     

Nanomechanical and Vibrational Signature of Chikungunya Viral Particles

Chikungunya virus (CHIKV) belongs to the genus Alphaviridae, with a single-stranded positive-sense RNA genome of 11.8 kbp encoding a polyprotein that generates both non-structural proteins and structural proteins. The virus is transmitted by the Aedes aegypti and A. albopictus mosquitoes, depending on the location. CHIKV infection leads to dengue-like musculoskeletal symptoms and has been responsible for several outbreaks worldwide since its discovery in 1952. Patients often experience fever, headache, muscle pain, joint swelling, and skin rashes. However, the ultrastructural and mechanical properties of CHIKV have not been fully characterized. Thus, this study aims to apply a physical approach to investigate CHIKV′s ultrastructural morphology and mechanical properties, using atomic force microscopy and Raman spectroscopy as the main tools. Using nanomechanical assays of AFM and a gold nanoparticles substrate for Raman signal enhancement, we explored the conformational plasticity, morphology, vibrational signature, and nanomechanical properties of the chikungunya virus, providing new information on its ultrastructure at the nanoscale and offering a novel understanding of the virus’ behavior upon mechanical disruptions besides its molecular composition.     

Individuals with peripheral vestibulopathy and poor quality of sleep are at a higher risk for falls

IntroductionThere is a lack of scientific studies on the assessment of patients with vestibular disorders associated with sleep quality disorders and its impact on the balance and overall quality of life.Objectivesto assess the impact of the sleep quality on the balance and quality of life of individuals with peripheral vestibulopathies.Methods52 individuals with peripheral vestibulopathies underwent sleep quality assessment through the Pittsburgh sleep quality index, neurotological examination through dizziness handicap inventory and Tetrax posturography (Sunlight Medical Ltd.) in eight sensory conditions. Thirty-two healthy individuals (G3) participated as the control group.ResultsFourteen individuals with vestibulopathy had good quality of sleep (G1) and 38 showed poor quality of sleep (G2) as demonstrated by the Pittsburgh sleep quality index global scores (p = 0.001). The dizziness handicap inventory showed worse impact of the dizziness on the quality of life in G2 when compared to G1 (p  = 0.045). The G₂ showed higher risk of falling in posturography when compared to G3 (p = 0.012) and higher index of postural instability in five sensory conditions in comparison with G3. In the vestibulopathy groups, the worse the sleep quality, the higher the risk of falling (r = 0.352) and the worse the quality of life (r = 0.327).ConclusionIndividuals with peripheral vestibulopathies and poor quality of sleep demonstrate worse balance evidenced by increased postural instability, higher risk of falls and worse perceived quality of life. The quality of sleep is a predictive factor for worse perceived quality of life and for higher risk of falls in individuals with peripheral vestibulopathies.     

Dysphagia in patients with moderate and severe obstructive sleep apnea

IntroductionThere is evidence that trauma caused by snoring in the pharynx could result in dysphagia in patients with obstructive sleep apnea, but the literature is still scarce to define the factors associated with the presence of dysphagia in these patients.ObjectivesTo analyze the occurrence of dysphagia and its clinical and polysomnographic features in patients with moderate and severe obstructive sleep apnea, in addition to verifying the impact of dysphagia on the quality of life of these patients.MethodsSeventy patients with moderate or severe apnea (apnea and hypopnea index – AHI > 15/hour) were selected. The patients underwent a sleep questionnaire, a quality of life in dysphagia questionnaire and a fiberoptic endoscopic evaluation of swallowing.ResultsA total of 70 patients were included in the study, of which 49 were men (70 %), with a mean age of 48.9 years. The fiberoptic endoscopic evaluation of swallowing was altered in 27.3 % and the most frequent alteration was the premature oral leakage with fluid. Comparing the groups with and without dysphagia, the female gender was the only clinical parameter that showed a trend of statistical significance in the group with dysphagia (p = 0.069). There was no statistical difference regarding the polysomnographic features and in the global quality of life score in dysphagia in the comparison between the groups.ConclusionsThe presence of dysphagia in patients with moderate to severe apnea is frequent and subclinical, reinforcing the need to investigate this symptom in this group of patients. However, the presence of dysphagia did not result in worsening in patients' quality of life, suggesting that, although frequent, its effect is mild. There was no relevance regarding the association of clinical and polysomnographic parameters with the presence of dysphagia.     

Management of respiratory complications and rehabilitation in individuals with muscular dystrophies: 1st Consensus Conference report from UILDM - Italian Muscular Dystrophy Association (Milan,January 25-26, 2019)

Respiratory complications are common in the patient with muscular dystrophy. The periodic clinical and instrumental respiratory evaluation is extremely important. Despite the presence in the literature of updated guidelines, patient associations often report lack of knowledge of these pathologies, particularly in peripheral hospitals. The purpose of this work, inspired by the Italian Muscular Dystrophy Association (UILDM) is to improve management of respiratory problems necessary for the management of these patients complex. To this end, the main items that the specialist can meet in the follow-up of these pathologies have been analyzed and discussed, among which the respiratory basal evaluation, the criteria of adaptation to non-invasive ventilation, management of bronchial secretions, situations of respiratory emergency, indications for tracheostomy and the subject of advance directives of treatment (DAT).Key words: respiratory failure, muscular dystrophy, cough efficacy, spirometry, polygraphy, non-invasive ventilation, arterial blood gases, cough machine, invasive ventilation, tracheostomy, mechanical ventilation     

Aug-MIA-QSPR Modeling of the Soil Sorption of Carboxylic Acid Herbicides

Soil sorption, described as logK_OC (the logarithm of the soil/water partition coefficient normalized to organic carbon), was modeled using the augmented multivariate image analysis applied to quantitative structure–property relationship method for a series of 11 carboxylic acid herbicides. The statistical model was found to be highly predictive and reliable to estimate logK_OC of other persistent organic pollutants in the soil, which are analogues of the carboxylic acids used in the QSPR model. The QSPR model derived from images corresponding to the chemical structures of the 11 herbicides is superior to the uniparameter model based on the octanol/water partition coefficient (logP) and, in addition, a pattern recognition model was built using principal component analysis. This model allowed clustering and separating compounds with low/moderate soil sorption from those with moderate/high soil sorption (compounds with the aryloxy function) using the second principal component.