Aesthetic perception of patient in developmental age in interceptive orthodontic treatment.

AIM: Patients at development age show considerable attention to the shape of the face from both an aesthetic and relational point of view, to arouse interest from researchers. There are few studies related to profile analysis in patients of developmental age. Therefore, the objective of the present study was to analyse the importance of the aesthetic perception of the patient in development age in relation to the profile, before and after interceptive orthodontic treatment. MATERIALS: A sample of 25 patients who came to our observation for dentoskeletal malocclusions was considered. A questionnaire was proposed to each patient, before and after the interceptive orthodontic treatment (T0 and T1), to evaluate the aesthetic perception before and after the orthodontic treatment and its psychosocial impact. Profile analysis was performed using photographic documentation (at T0 and T1). The variables considered were the Ricketts line, the facial convexity angle, the nasolabial angle, and the labiomental angle. CONCLUSION: Interceptive orthodontic treatment has proven to be of valid clinical and psychological help. This result is confirmed by the complete aesthetic satisfaction of the patient in the frontal and latero-lateral planes.

Chemotherapy-induced oral mucositis in children and adolescents: a systematic review.

PURPOSE: The present systematic review aims to describe the incidence and severity of chemotherapy-related oral mucositis in children and adolescents affected by hematologic and solid tumors. METHODS: An electronic search was performed on PubMed, Scopus, Web of Science, Cochrane Library, and EBSCO up to the 8th November 2020. The PRISMA protocol was followed for the article selection and inclusion. The risk of bias in individual studies was evaluated through the Newcastle-Ottawa Scale. Data were summarized using mean and standard deviation for continuous variables, while categorical ones were described with frequency and percentage. RESULTS: A number of 9940 records were obtained after the electronic search. Seventeen of them were included in the qualitative analysis after the two stages of screening, while none of these articles was considered eligible for the quantitative analysis. The mean incidence of oral mucositis was 53.6% and it ranged from 16.7 to 91.5%, while severe oral mucositis accounted for the 15.8% (0.0-35.2%) among selected studies. Most of the articles included both patients with solid and hematologic tumors, while only five of them described oral mucositis in children with acute lymphoblastic leukemia. Even the kinds of chemotherapy administered were extremely variable. CONCLUSION: In conclusion, about half of the patients submitted to cancer chemotherapy developed oral mucositis with an incidence and severity that varies depending on the primary disease and the kind of drugs administered.

Temporal summation of the nociceptive withdrawal reflex involves deactivation of posterior cingulate cortex.

BACKGROUND: Temporal summation of pain sensation is pivotal both in physiological and pathological nociception. In humans, it develops in parallel with temporal summation of the nociceptive withdrawal reflex (NWR) of the lower limb, an objective representation of the temporal processing of nociceptive signals into the spinal cord. METHODS: To study the contribution of cortical and subcortical structures in temporal summation of pain reflex responses, we compared the fMRI signal changes related to the temporal summation threshold (TST) of the NWR with that related to the single NWR response. We studied 17 healthy subjects using a stimulation paradigm previously determined to evoke both the TST of the NWR (SUMM) and the NWR single response (SING). RESULTS: We found a significant activation in left (contralateral) primary somatosensory cortex (SI), bilateral secondary somatosensory cortex (SII), bilateral insula, anterior cingulate cortex (ACC) and bilateral thalamus during both SUMM and SING conditions. The SUMM versus SING contrast revealed a significant deactivation in the posterior cingulate cortex (PCC) and bilateral middle occipital gyrus in SUMM when compared to SING condition. CONCLUSIONS: Our data support the hypothesis that temporal summation of nociceptive reflex responses is driven through a switch between activation and deactivation of a specific set of brain areas linked to the default mode network. This behaviour could be explained in view of the relevance of the pain processing induced by temporal summation, recognized as a more significant potential damaging condition with respect to a single, isolated, painful stimulation of comparable pain intensity. SIGNIFICANCE: The study demonstrated that TST of the NWR involves a selective deactivation of PCC.

Modulation of temporal summation threshold of the nociceptive withdrawal reflex by transcutaneous spinal direct current stimulation in humans.

OBJECTIVE: Transcutaneous spinal direct current stimulation (tsDCS) modulates spinal cord pain pathways. The study is aimed to clarify the neurophysiology of the tsDCS-induced modulation of the spinal cord pain processing by evaluating the effect of the tsDCS on temporal summation threshold (TST) of the nociceptive withdrawal reflex (NWR). METHODS: In a randomized, double-blind, crossover study the effects of anodal, cathodal and sham tsDCS (2 mA, 15 min) applied on the skin overlying the thoracic spinal cord were investigated in 10 healthy subjects. RESULTS: Anodal tsDCS induced a long-lasting (up to 60 min) increase in TST of the NWR as well as a parallel decrease in related psychophysical temporal summation of pain, while cathodal and sham tsDCS resulted ineffective. CONCLUSIONS: Anodal tsDCS represents a non-invasive tool able to induce an early and long-lasting depression of the transitory facilitation of the wide dynamic range neurons activity at the basis of both the temporal summation of the NWR and the related temporal summation of pain sensation. SIGNIFICANCE: The modulation of the temporal processing of nociceptive stimuli could be effective in treating clinical pain conditions in which pain is generated by spinal cord structures.

Three-Dimensional Optoacoustic and Laser-Induced Ultrasound Tomography System for Preclinical Research in Mice: Design and Phantom Validation.

In this work, we introduce a novel three-dimensional imaging system for in vivo high-resolution anatomical and functional whole-body visualization of small animal models developed for preclinical and other type of biomedical research. The system (LOUIS-3DM) combines a multiwavelength optoacoustic tomography (OAT) and laser-induced ultrasound tomography (LUT) to obtain coregistered maps of tissue optical absorption and speed of sound, displayed within the skin outline of the studied animal. The most promising applications of the LOUIS-3DM include 3D angiography, cancer research, and longitudinal studies of biological distributions of optoacoustic contrast agents.

3T diffusion tensor imaging and electroneurography of peripheral nerve: a morphofunctional analysis in carpal tunnel syndrome.

OBJECTIVE: The aim of the study was to assess the diagnostic potential of diffusion tensor imaging (DTI) for pathologies of the peripheral nervous system (PNS) through clinical, electrophysiological and morphological evaluation of the median nerve. METHODS: The present work was a multilevel prospective study involving 30 subjects, 15 of whom had carpal tunnel syndrome (CTS) and 15 healthy controls. All subjects underwent clinical evaluation through administration of the Boston Carpal Tunnel Questionnaire (BCTQ), electroneurography (ENG), 3-Tesla magnetic resonance imaging with DTI, and calculation of fractional anisotropy (FA) and the apparent diffusion coefficient (ADC) at the flexor retinaculum. Tractography was also performed for three-dimensional reconstruction of the route of the median nerve through the carpal tunnel. The degree of functional impairment was compared with the anatomical damage to the median nerve according to ENG and DTI. RESULTS: FA and ADC were significantly correlated with ENG parameters of CTS and BCTQ data. Mean FA and ADC values in the CTS patients were 0.359±0.06 and 1.866±0.050×10(-3)mm(2)/s, respectively, vs 0.59±0.014 and 1.395±0.035×10(-3)mm(2)/s, respectively, in the controls. FA was decreased and ADC increased in patients with CTS compared with healthy controls (P<0.05). CONCLUSION: DTI parameters were clearly confirmed by both clinical and ENG data and, therefore, may be used for the diagnosis of CTS.

Characterization of speckle in lung images acquired with a benchtop in-line x-ray phase-contrast system.

We investigate the manifestation of speckle in propagation-based x-ray phase-contrast imaging of mouse lungs in situ by use of a benchtop imager. The key contributions of the work are the demonstration that lung speckle can be observed by use of a benchtop imaging system employing a polychromatic tube-source and a systematic experimental investigation of how the texture of the speckle pattern depends on the parameters of the imaging system. Our analyses consists of image texture characterization based on the statistical properties of pixel intensity values.

An initial evaluation of analyser-based phase-contrast X-ray imaging of carotid plaque microstructure.

Carotid artery plaque instability can result in rupture and lead to ischaemic stroke. Stability of plaques appears to be a function of composition. Current non-invasive imaging techniques are limited in their ability to classify distinct histological regions within plaques. Phase-contrast (PC) X-ray imaging methods are an emerging class of techniques that have shown promise for identifying soft-tissue features without use of exogenous contrast agents. This is the first study to apply analyser-based X-ray PC imaging in CT mode to provide three-dimensional (3D) images of excised atherosclerotic plaques. The results provide proof of principle for this technique as a promising method for analysis of carotid plaque microstructure. Multiple image radiography CT (MIR-CT), a tomographic implementation of X-ray PC imaging that employs crystal optics, was employed to image excised carotid plaques. MIR-CT imaging yields three complementary images of the plaque's 3D X-ray absorption, refraction and scatter properties. These images were compared with histological sections of the tissue. X-ray PC images were able to identify the interface between the plaque and the medial wall. In addition, lipid-rich and highly vascularized regions were visible in the images as well as features depicting inflammation. This preliminary research shows MIR-CT imaging can reveal details about plaque structure not provided by traditional absorption-based X-ray imaging and appears to identify specific histological regions within plaques. This is the first study to apply analyser-based X-ray PC imaging to human carotid artery plaques to identify distinct soft-tissue regions.

SU-F-BRCD-09: Total Variation (TV) Based Fast Convergent Iterative CBCT Reconstruction with GPU Acceleration.

PURPOSE: To improve image quality and reduce imaging dose in CBCT for radiation therapy applications and to realize near real-time image reconstruction based on use of a fast convergence iterative algorithm and acceleration by multi-GPUs. METHODS: An iterative image reconstruction that sought to minimize a weighted least squares cost function that employed total variation (TV) regularization was employed to mitigate projection data incompleteness and noise. To achieve rapid 3D image reconstruction (< 1 min), a highly optimized multiple-GPU implementation of the algorithm was developed. The convergence rate and reconstruction accuracy were evaluated using a modified 3D Shepp-Logan digital phantom and a Catphan-600 physical phantom. The reconstructed images were compared with the clinical FDK reconstruction results. RESULTS: Digital phantom studies showed that only 15 iterations and 60 iterations are needed to achieve algorithm convergence for 360-view and 60-view cases, respectively. The RMSE was reduced to 10-4 and 10-2, respectively, by using 15 iterations for each case. Our algorithm required 5.4s to complete one iteration for the 60-view case using one Tesla C2075 GPU. The few-view study indicated that our iterative algorithm has great potential to reduce the imaging dose and preserve good image quality. For the physical Catphan studies, the images obtained from the iterative algorithm possessed better spatial resolution and higher SNRs than those obtained from by use of a clinical FDK reconstruction algorithm. CONCLUSIONS: We have developed a fast convergence iterative algorithm for CBCT image reconstruction. The developed algorithm yielded images with better spatial resolution and higher SNR than those produced by a commercial FDK tool. In addition, from the few-view study, the iterative algorithm has shown great potential for significantly reducing imaging dose. We expect that the developed reconstruction approach will facilitate applications including IGART and patient daily CBCT-based treatment localization.

The optimal age for performing surgery on patients with MEN 2B syndrome.

Multiple endocrine neoplasia (MEN) syndromes are characterized by the association of various endocrine neoplasias. Prophylactic thyroidectomy is the treatment of choice for patients with RET gene mutations. The age at which patients undergo prophylactic thyroidectomy may vary depending on the position of the RET gene codon. In cases of MEN 2B, when the mutation is carried in codons 883, 918 or 922, prophylactic thyroidectomy is performed prior to 6 months of age, due to the increased aggressiveness of these heterozygosities, which are capable of determining the onset of medullary cancer during the first months of life. We present two heterozygous twin patients with MEN 2B syndrome who were born 32 weeks premature, and who underwent prophylactic thyroidectomy at 7 months of age. The patients were carriers of the mutation at codon 918. We suggested the early surgery at 7 months as, due to their prematurity, the patients were required to gain weight to improve their condition prior to surgery. The two patients had medullary thyroid carcinoma without lymph node involvement. In conclusion, for a truly prophylactic thyroidectomy, such patients should undergo surgery within the first month of life, particularly if these patients are carriers of the mutation in codons 883, 918 or 922.

Heterotrophic microorganisms in deteriorated medieval wall paintings in southern Italian churches.

The Campania region in southern Italy is noted for its large number of churches that harbour invaluable frescoes, dated from the beginnings of the 4th up to the 13th century. The wall paintings represent an integral part of the monuments, and their deterioration constitutes a potentially significant loss for the world's cultural heritage. Heterotrophic microorganisms such as bacteria and mould can grow on the surface of paintings that contain a wide range of organic and inorganic constituents, and provide different ecological niches that are exploited by a large variety of microbial species. We isolated and identified the heterotrophic microorganisms found in the biodegraded medieval wall paintings of seven historical churches in Campania. The paintings showed different levels of microbial contamination. Microbiological analysis of different paintings gave an overview of the different heterotrophic microorganisms. Bacteria and moulds were isolated from 77% of the sampling points analysed, in which the most common type of alteration was discolouration often associated with detachment of the paint layer. Bacterial strains were identified by 16S rRNA partial sequence analysis. The Bacillus genus was isolated in all churches, even though the type of species was variable, whereas all actinomycetes strains, isolated in five of the seven churches analysed, could be referred to the Streptomyces genus. The similarity of the sequences analysed of the 42 Bacillus spp., 2 Paenibacillus spp. and reference strains of different species showed that these bacteria differentiated in 14 groups. The most frequently occurring taxa were most closely related to Bacillus cereus/thurigiensis/anthracis and Bacillus pumilus groups. Thirteen Streptomyces spp. were differentiated in seven groups on the basis of neighbor-joining analysis of 16S rRNA. Fungi belonging to the genera Penicillium, Aspergillus, Fusarium and Alternaria were also isolated from deteriorated wall paintings.

Comparison of physiological responses to an incremental running test on treadmill, natural grass, and synthetic turf in young soccer players.

This study aimed to compare the physiological responses to a running test often used to assess lactate thresholds in soccer players when performed with an identical protocol on treadmill (Tr), natural grass (Nat), and synthetic turf (Synt). Eighteen young soccer players (mean +/- SD: age, 17.4 +/- 0.8 years; body mass, 66.2 +/- 6.7 kg; height, 175.8 +/- 5.7 cm) performed on each surface a multistage running test, including 4-minutes stages separated by a 1-minute rest, with initial speed set at 8 kmxh and increased of 2 km.h after each stage. Blood lactate concentration (La) and heart rate (HR) were assessed. The test ended when La exceeded 4 mmolxL. At each of the stages completed in the three conditions by all the subjects (8, 10, 12, and 14 kmxh), La was higher in Synt vs. both Nat and Tr with differences of at least 0.6 mmolxL (p < 0.05), whereas HR was higher (p < 0.05) in Synt vs. Nat with differences from 4.3 bxmin (at 10 kmxh) to 6.4 bxmin (at 8 kmxh). Running speed at the 4 mmolxL La threshold was lower (p < 0.05) in Synt (13.1 +/- 1.1 kmxh) than in Nat (13.9 +/- 1.2 kmxh) and Tr (14.4 +/- 1.3 kmxh). The La/HR curve obtained in Synt was shifted upward compared with the Nat and Tr curves, indicating higher La values at given HRs. These results could be mostly explained by adaptations of running mechanical patterns to surface properties that affect the energy requirements of running. This study emphasized the importance of testing soccer players on the specific surface used for training activities when assessing lactate threshold indices to prescribe and monitor field training.

Data redundancy and reduced-scan reconstruction in reflectivity tomography.

In reflectivity tomography, conventional reconstruction approaches require that measurements be acquired at view angles that span a full angular range of 2pi. It is often, however, advantageous to reduce the angular range over which measurements are acquired, in order, for example, to minimize artifacts due to movements of the imaged object. Moreover, in certain situations, it may not be experimentally possible to collect data over a 2pi angular range. We investigate the problem of reconstructing images from reduced-scan data in reflectivity tomography. By exploiting symmetries in the data function of reflectivity tomography, we demonstrate heuristically that an image function can be uniquely specified by reduced-scan data that correspond to measurements taken over an angular interval (possibly disjoint) that spans at least pi radians. We also identify sufficient conditions that permit for a stable reconstruction of image boundaries from reduced-scan data. Numerical results in computer-simulation studies indicate that images can be reconstructed accurately from reduced-scan data.

Comments on the filtered backprojection algorithm, range conditions, and the pseudoinverse solution.

The filtered backprojection (FBP) algorithm is widely used in computed tomography for inverting the two-dimensional Radon transform. In this paper, we analyze the processing of an inconsistent data function by the FBP algorithm (in its continuous form). Specifically, we demonstrate that an image reconstructed using the FBP algorithm can be represented as the sum of a pseudoinverse solution and a residual image generated from an inconsistent component of the measured data. This reveals that, when the original data function is in the range of the Radon transform, the image reconstructed using the FBP algorithm corresponds to the pseudoinverse solution. When the data function is inconsistent, we demonstrate that the FBP algorithm makes use of a nonorthogonal projection of the data function to the range of the Radon transform.

Full- and minimal-scan reconstruction algorithms for fan-beam diffraction tomography.

Diffraction tomography (DT) is a tomographic inversion technique that reconstructs the spatially variant refractive-index distribution of a scattering object. In fan-beam DT, the interrogating radiation is not a plane wave but rather a cylindrical wave front emanating from a line source located a finite distance from the scattering object. We reveal and examine the redundant information that is inherent in the fan-beam DT data function. Such redundant information can be exploited to reduce the reconstructed image variance or, alternatively, to reduce the angular scanning requirements of the fan-beam DT experiment. We develop novel filtered backpropagation and estimate-combination reconstruction algorithms for full-scan and minimal-scan fan-beam DT. The full-scan algorithms utilize measurements taken over the angular range 0

Relation between the bowel electromyogram and the intestinal pressure wave. An experimental study in dogs.

OBJECTIVE: A linear regression study is made of the parameters identifying the electrical activity of the small bowel, with the aim of determining those variables most closely related to the type I pressure waves. PATIENTS AND METHODS: A computer system was used for the simultaneous and real time acquisition of the manometric activity (using microballoons implanted in the bowel mucosa) and electromyogram of the intestine (employing bipolar electrodes implanted in the intestinal serosa) in dogs. RESULTS: Of the electromyogram intestinal parameters studied, those determining signal energy (root mean square voltage and energy) yielded the highest correlation coefficients (0.71 +/- 0.08 in the jejunum and 0.78 +/- 0.06 in the duodenum) to bowel pressure. Peak-to-peak voltage also shows good correlation, though to a lesser degree. The rest of the parameters studied, such as those that measure the duration of the action potential or its number of peaks, yielded poor correlations to pressure. CONCLUSIONS: It is concluded that the energy of the intestinal electromyogram represents the mechanical activity of the small bowel, reflecting intestinal motility, and that the recording of this parameter is not subjected to subjective cutoff values or threshold levels. On the other hand, and unlike in the case of manometric recordings, the signal obtained is free of background interference and noise.

Computationally efficient and statistically robust image reconstruction in three-dimensional diffraction tomography.

Diffraction tomography (DT) is an inversion scheme used to reconstruct the spatially variant refractive-index distribution of a scattering object. We developed computationally efficient algorithms for image reconstruction in three-dimensional (3D) DT. A unique and important aspect of these algorithms is that they involve only a series of two-dimensional reconstructions and thus greatly reduce the prohibitively large computational load required by conventional 3D reconstruction algorithms. We also investigated the noise characteristics of these algorithms and developed strategies that exploit the statistically complementary information inherent in the measured data to achieve a bias-free reduction of the reconstructed image variance. We performed numerical studies that corroborate our theoretical assertions.

Design and synthesis of piperazine-based matrix metalloproteinase inhibitors.

A new generation of cyclic matrix metalloproteinase (MMP) inhibitors derived from dl-piperazinecarboxylic acid has been described. The design involves: incorporation of hydroxamic acid as the bidentate chelating agent for catalytic Zn(2+), placement of a sulfonamide group at the 1N-position of the piperazine ring to fill the S1' pocket of the enzyme, and finally attachment of diverse functional groups at the 4N-position to optimize potency and peroral absorption. A unique combination of all three elements produced inhibitor 20 with high affinity for MMPs 1, 3, 9, and 13 (24, 18, 1.9, and 1.3 nM, respectively). X-ray crystallography data obtained for MMP-3 cocrystallized with 20 gave detailed information on key binding interactions defining an overall scaffold geometry for piperazine-based MMP inhibitors.

A new reconstruction approach for reflection mode diffraction tomography.

Reflection mode diffraction tomography (RM DT) is an inversion scheme used to reconstruct the acoustical refractive index distribution of a scattering object. In this work, we reveal the existence of statistically complementary information inherent in the backscattered data and propose reconstruction algorithms that exploit this information for achieving a bias-free reduction of image variance in RM DT images. Such a reduction of image variance can potentially enhance the detectability of subtle image features when the signal-to-noise ratio of the measured scattered data is low in RM DT. The proposed reconstruction algorithms are mathematically identical, but they propagate noise and numerical errors differently. We investigate theoretically, and validate numerically, the noise properties of images reconstructed using one of the reconstruction algorithms for several different multifrequency sources and uncorrelated data noise.

Multiobjective genetic optimization of diagnostic classifiers with implications for generating receiver operating characteristic curves.

It is well understood that binary classifiers have two implicit objective functions (sensitivity and specificity) describing their performance. Traditional methods of classifier training attempt to combine these two objective functions (or two analogous class performance measures) into one so that conventional scalar optimization techniques can be utilized. This involves incorporating a priori information into the aggregation method so that the resulting performance of the classifier is satisfactory for the task at hand. We have investigated the use of a niched Pareto multiobjective genetic algorithm (GA) for classifier optimization. With niched Pareto GA's, an objective vector is optimized instead of a scalar function, eliminating the need to aggregate classification objective functions. The niched Pareto GA returns a set of optimal solutions that are equivalent in the absence of any information regarding the preferences of the objectives. The a priori knowledge that was used for aggregating the objective functions in conventional classifier training can instead be applied post-optimization to select from one of the series of solutions returned from the multiobjective genetic optimization. We have applied this technique to train a linear classifier and an artificial neural network (ANN), using simulated datasets. The performances of the solutions returned from the multiobjective genetic optimization represent a series of optimal (sensitivity, specificity) pairs, which can be thought of as operating points on a receiver operating characteristic (ROC) curve. All possible ROC curves for a given dataset and classifier are less than or equal to the ROC curve generated by the niched Pareto genetic optimization.