By combining quantum-mechanical analysis and statistical survey of peptide/protein structure databases we here report a thorough investigation of the conformational dependence of the geometry of ...peptide bond, the basic element of protein structures. Different peptide model systems have been studied by an integrated quantum mechanical approach, employing DFT, MP2 and CCSD(T) calculations, both in aqueous solution and in the gas phase. Also in absence of inter-residue interactions, small distortions from the planarity are more a rule than an exception, and they are mainly determined by the backbone ψ dihedral angle. These indications are fully corroborated by a statistical survey of accurate protein/peptide structures. Orbital analysis shows that orbital interactions between the σ system of C(α) substituents and the π system of the amide bond are crucial for the modulation of peptide bond distortions. Our study thus indicates that, although long-range inter-molecular interactions can obviously affect the peptide planarity, their influence is statistically averaged. Therefore, the variability of peptide bond geometry in proteins is remarkably reproduced by extremely simplified systems since local factors are the main driving force of these observed trends. The implications of the present findings for protein structure determination, validation and prediction are also discussed.
•Acquisition of gait analysis for patients affected by PD and PSP.•Extraction of spatial and temporal parameters for each patient.•Implementation of ensembles of trees (Random forests and gradient ...boosted Tree) to distinguish typical and atypical forms of parkinson.
Parkinson's disease (PD) is the second most common neurodegenerative disorder in the world, while Progressive Supranuclear Palsy (PSP) is an atypical Parkinsonism resembling PD, especially in early stage. Assumed that gait dysfunctions represent a major motor symptom for both pathologies, gait analysis can provide clinicians with subclinical information reflecting subtle differences between these diseases. In this scenario, data mining can be exploited in order to differentiate PD patients at different stages of the disease course and PSP using all the variables acquired through gait analysis.
A cohort of 46 subjects (divided into three groups) affected by PD patients at different stages and PSP patients was acquired through gait analysis and spatial and temporal parameters were analysed. Synthetic Minority Over-sampling Technique was used to balance our imbalanced dataset and cross-validation was applied to provide different training and testing sets. Then, Random Forests and Gradient Boosted Trees were implemented.
Accuracy, error, precision, recall, specificity and sensitivity were computed for each group and for both algorithms, including 16 features. Random Forests obtained the highest accuracy (86.4%) but also specificity and sensitivity were particularly high, overcoming the 90% for PSP group.
The novelty of the study is the use of a data mining approach on the spatial and temporal parameters of gait analysis in order to classify patients affected by typical (PD) and atypical Parkinsonism (PSP) based on gait patterns. This application would be helpful for clinicians to distinguish PSP from PD at early stage, when the differential diagnosis is particularly challenging.
Pleomorphic adenomas are rounded, lumpy, capsulated lesions that are more common in women. They are typically benign, but can be associated with malignancy in a minority of cases (such as carcinoma ...ex pleomorphic adenoma), between 3% - 12% of the time, according to available data. The purpose of our study was to evaluate clinical outcomes in patients with benign parotid gland tumours after extracapsular dissection (ECD) or superficial parotidectomy (SP). We made a retrospective study of 297 patients who had had benign tumours of the parotid gland, and had been referred to our department from 2002 – 2016 to have either procedure. We measured the statistical differences between the two techniques (evaluated recurrence rate and complications) with the chi squared test. The chosen level of statistical significance was p<0.05. Median (range) follow-up time was 43 months (25–168) months. Haematoma and hypoaesthesia were significantly more common after SP than after ECD (8.9% compared with 7.7%, and 16.8% compared with 5.6%, respectively). Transient facial nerve injury, Frey syndrome, and facial paralysis were significantly more common after SP than after ECD (23.6% compared with 1.5%, 6.7% compared with 1% and 6,7% compared with 0%, respectively). ECD had the advantage of reduced operating time, lower morbidity and lower recurrence rate, and could be considered the treatment of choice for pleomorphic adenoma of the parotid gland up (to 3cm) which are mobile and sited in the superficial lobe of the parotid gland.
By combining quantum‐mechanical analysis of small model peptides and statistical surveys of high‐resolution protein structures, a systematic conformational dependence of bond lengths in polypeptide ...backbones has been unveiled which involves both the peptide bond (C—O and C—N) and those bonds centred on the Cα atom. All of these bond lengths indeed display a systematic variability in the ψ angle according to both calculations and surveys of protein structures. The overall agreement between the computed and the statistical data suggests that these trends are essentially driven by local effects. The dependence of Cα distances on ψ is governed by interactions between the σ system of the Cα moiety and the C—O π system of the peptide bond. Maximum and minimum values for each bond distance are found for conformations with the specific bond perpendicular and parallel to the adjacent CONH peptide plane, respectively. On the other hand, the variability of the C—O and C—N distances is related to the strength of the interactions between the lone pair of the N atom and the C—O π* system, which is modulated by the ψ angle. The C—O and C—N distances are related but their trends are not strictly connected to peptide‐bond planarity, although a correlation amongst all of these parameters is expected on the basis of the classical resonance model.
Developmental data suggested that mental simulation skills become progressively dissociated from overt motor activity across development. Thus, efficient simulation is rather independent from current ...sensorimotor information. Here, we tested the impact of bodily (sensorimotor) information on simulation skills of adolescents with Autism Spectrum Disorders (ASD). Typically-developing (TD) and ASD participants judged laterality of hand images while keeping one arm flexed on chest or while holding both arms extended. Both groups were able to mentally simulate actions, but this ability was constrained by body posture more in ASD than in TD adolescents. The strong impact of actual body information on motor simulation implies that simulative skills are not fully effective in ASD individuals.
Compartment syndrome can occur in many body regions and may range from homeostasis asymptomatic alterations to severe, life-threatening conditions. Surgical intervention to decompress affected organs ...or area of the body is often the only effective treatment, although evidences to assess the best timing of intervention are lacking. Present paper systematically reviewed the literature stratifying timings according to the compartmental syndromes which may beneficiate from immediate, early, delayed, or prophylactic surgical decompression. Timing of decompression have been stratified into four categories: (1) immediate decompression for those compartmental syndromes whose missed therapy would rapidly lead to patient death or extreme disability, (2) early decompression with the time burden of 3-12 h and in any case before clinical signs of irreversible deterioration, (3) delayed decompression identified with decompression performed after 12 h or after signs of clinical deterioration has occurred, and (4) prophylactic decompression in those situations where high incidence of compartment syndrome is expected after a specific causative event.
Hyaluronic Acid (HA) plays many roles in wound healing in general, through different mechanisms. Several authors reported the effectiveness of hyaluronic acid in promoting mucosal healing and ...reducing discomfort for patients after endoscopic sinus surgery (ESS). Different methods for HA nasal administration have been reported. The aim of our study has been to evaluate the efficacy of the administration of nebulized HA through a nasal douche compared with its administration through a nasal spray with patients undergoing ESS for chronic rhinosinusitis. From January 2013 to January 2019 a prospective clinical trial was carried out in our hospital with 163 patients who had undergone ESS for chronic rhinosinusitis. The sample was divided into three groups according to the method of administration of HA. Our study confirm the efficacy of the administration of nebulized HA through nasal douche in post-operative care (6.5% vs 4.5%). The most relevant data regards the nasal dryness sign: the data revealed an unexpected percentage of worsening of that sign at time T3 (
p
= 0.049) particularly evident in the patients treated with HA through nasal douche compared to whom the nasal spray device was prescribed (4% vs 1%). Further studies are needed to identify the best means of administration of HA, which would satisfy the requirements for efficacy in terms of the results and, at the same time, patient compliance.
Monitoring of foetal heart rate and its variability (FHRV) covers an important role in assessing health of foetus. Many analysis methods have been used to get quantitative measures of FHRV. FHRV has ...been studied in time and in frequency domain and interesting clinical results have been obtained. Nevertheless, a standardized definition of FHRV and a precise methodology to be used for its evaluation are lacking. We carried out a literature overview about both frequency domain analysis (FDA) and time domain analysis (TDA). Then, by using simulated FHR signals, we defined the methodology for FDA. Further, employing more than 400 real FHR signals, we analysed some of the most common indexes, Short Term Variability for TDA and power content of the spectrum bands and sympathovagal balance for FDA, and evaluated their ranges of values, which in many cases are a novelty. Finally, we verified the relationship between these indexes and two important parameters: week of gestation, indicator of foetal growth, and foetal state, classified as active or at rest. Our results indicate that, according to literature, it is necessary to standardize the procedure for FHRV evaluation and to consider week of gestation and foetal state before FHR analysis.
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