Ferimento facial por projétil de arma de fogo: avaliação dos resultados e complicações de 52 pacientes tratados

Pós-graduação em Odontologia - FOA

The Primary Closure Approach of Dog Bite Injuries of the Nose

The nose holds an outstanding position on the face, acquiring great importance within the context of facial aesthetics. Because of the functional, psychological, and social aspects of trauma in a society increasingly demanding about aesthetics, treatment institution must reduce, as accurate as possible, the sequelae that hinder social integration. This clinical report relates an immediate nasal reconstruction of a complex animal bite wound. A 7-year-old patient was victim of a dog bite with avulsion of the left nasal ala and part of the ipsilateral nasal tip. The treatment was immediate nasal reconstruction with auricular composite graft. After 1 year of follow-up, the shape of nasal ala was stable, and the color was consistent with the surrounding tissue. The 2 nasal sides exhibited satisfactory symmetry when evaluated. It can be concluded that the composite graft derived from the auricular helix is a safe option for reconstruction of nasal ala defects with compromised margins in pediatric patients when conditions of reimplantation do not exist.

Quantification of Biological Tissue and Construction of Patient Equivalent Phantom (Skull and Chest) for Infants (1-5 years old)

Our main purpose in this study was to quantify biological tissue in computed tomography (CT) examinations with the aim of developing a skull and a chest patient equivalent phantom (PEP), both specific to infants, aged between 1 and 5 years old. This type of phantom is widely used in the development of optimization procedures for radiographic techniques, especially in computed radiography (CR) systems. In order to classify and quantify the biological tissue, we used a computational algorithm developed in Matlab (R). The algorithm performed a histogram of each CT slice followed by a Gaussian fitting of each tissue type. The algorithm determined the mean thickness for the biological tissues (bone, soft, fat, and lung) and also converted them into the corresponding thicknesses of the simulator material (aluminum, PMMA, and air). We retrospectively analyzed 148 CT examinations of infant patients, 56 for skull exams and 92 were for chest. The results provided sufficient data to construct a phantom to simulate the infant chest and skull in the posterior anterior or anterior posterior (PA/AP) view. Both patient equivalent phantoms developed in this study can be used to assess physical variables such as noise power spectrum (NPS) and signal to noise ratio (SNR) or perform dosimetric control specific to pediatric protocols.

Treatment of osteochondral injuries with platelet gel

OBJECTIVES: Treatments for injured articular cartilage have not advanced to the point that efficient regeneration is possible. However, there has been an increase in the use of platelet-rich plasma for the treatment of several orthopedic disorders, including chondral injuries. Our hypothesis is that the treatment of chondral injuries with platelet gel results in higher-quality repair tissue after 180 days compared with chondral injuries not treated with gel.METHODS: A controlled experimental laboratory study was performed on 30 male rabbits to evaluate osteochondral injury repair after treatment with or without platelet gel. Osteochondral injuries were surgically induced in both knees of each rabbit at the medial femoral condyle. The left knee injury was filled with the platelet gel, and the right knee was not treated. Microscopic analysis of both knee samples was performed after 180 days using a histological grading scale.RESULTS: The only histological evaluation criterion that was not significantly different between treatments was metachromasia. The group that was treated with platelet gel exhibited superior results in all other criteria (cell morphology, surface regularity, chondral thickness and repair tissue integration) and in the total score.CONCLUSION: The repair tissue was histologically superior after 180 days in the study group treated with platelet gel compared with the group of untreated injuries.

Biological effects of soft denture reline materials on L929 cells in vitro

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Therapeutic potential of mesenchymal stem cells to treat Achilles tendon injuries

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Antimicrobial activity of a tissue conditioner combined with a biocide polymer

The characteristics of tissue conditioners support microorganism development that can threaten the health of the dentures user. The object of this study was to evaluate the effect on antimicrobial activity, roughness and wettability surface of a tissue conditioners material combined with the antimicrobial polymer poly (2-tert-butilaminoethyl) methacrylate (PTBAEMA). Specimens of tissue conditioner (Coe Soft(®)) were divided into three groups, according to the concentration of PTBAEMA incorporated (0, 10 and 25%). Antimicrobial activity was assessed by adherence assay of one of the microorganisms, Staphylococcus aureus, Streptococcus mutans and Candida albicans. Roughness measurements were made using a Mitutoyo SJ-400, and the mean arithmetic roughness values (Ra) obtained were used for the comparisons. The wettability properties were determined by contact angle measurements. The group containing 25% of PTBAEMA inhibited totally the S. aureus and S. mutans biofilm formation. A significant reduc tion in the S. aureus (Kruskal-Wallis, p = 0,001) and S. mutans (Kruscal-Wallis, p = 0,001) count for 10% PTBAEMA group compared with respective control group. No significant difference was found for C. albicans among PTBAEMA groups and control group (ANOVA, p > 0,05). Incorporating 10 and 25% PTBAEMA increased surface roughness and decreased contact angles (ANOVA and Tukey's post hoc tests, α = 5%). Incorporating 10% PTBAEMA into tissue conditioner increases wettability and roughness of tissue conditioner surface; and decreases the adhesion of S. mutans and S. aureus on material surface, but did not exhibit antimicrobial effect against C. albicans. The PTBAEMA incorporated into tissue conditioner could prevent biofilm formation on elderly patient.

Does spinal block through tattooed skin cause histological changes in nervous tissue and meninges?: an experimental model in rabbits

Although there is no documented evidence that tattoo pigments can cause neurological complications, the implications of performing neuraxial anesthesia through tattooed skin are unknown. In this study, we aimed to assess whether spinal puncture performed through tattooed skin of rabbits determines changes over the spinal cord and meninges. In addition, we sought to evaluate the presence of ink fragments entrapped in spinal needles. Thirty-six young male adult rabbits, each weighing between 3400 and 3900 g and having a spine length between 38.5 and 39 cm, were divided by lot into 3 groups as follows: GI, spinal puncture through tattooed skin; GII, spinal puncture through tattooed skin and saline injection; and GIII, spinal puncture through skin free of tattoo and saline injection. After intravenous anesthesia with ketamine and xylazine, the subarachnoid space was punctured at S1-S2 under ultrasound guidance with a 22-gauge 2½ Quincke needle. Animals in GII and GIII received 5 μL/cm of spinal length (0.2 mL) of saline intrathecally. In GI, the needle tip was placed into the yellow ligament, and no solution was injected into the intrathecal space; after tattooed skin puncture, 1 mL of saline was injected through the needle over a histological slide to prepare a smear that was dyed by the Giemsa method to enable tissue identification if present. All animals remained in captivity for 21 days under medical observation and were killed by decapitation. The lumbosacral spinal cord portion was removed for histological analysis using hematoxylin-eosin stain. None of the animals had impaired motor function or decreased nociception during the period of clinical observation. None of the animals from the control group (GIII) showed signs of injuries to meninges. In GII, however, 4 animals presented with signs of meningeal injury. The main histological changes observed were focal areas of perivascular lymphoplasmacyte infiltration in the pia mater and arachnoid. There was no signal of injury in neural tissue in any animal of both groups. Tissue coring containing ink pigments was noted in all GI smears from the spinal needles used to puncture the tattooed skin. On the basis of the present results, intrathecal injection of saline through a needle inserted through tattooed skin is capable of producing histological changes over the meninges of rabbits. Ink fragments were entrapped inside the spinal needles, despite the presence of a stylet.

Ultrasound Transient Shear Wave Elasticity Imaging for Tendon Tissue

Degeneration of tendon tissue is a common cause of tendon dysfunction with the symptoms of repeated episodes of pain and palpable increase of tendon thickness. Tendon mechanical properties are directly related to its physiological composition and the structural organization of the interior collagen fibers which could be altered by tendon degeneration due to overuse or injury. Thus, measuring mechanical properties of tendon tissue may represent a quantitative measurement of pain, reduced function, and tissue health. Ultrasound elasticity imaging has been developed in the last two decades and has proved to be a promising tool for tissue elasticity imaging. To date, however, well established protocols of tendinopathy elasticity imaging for diagnosing tendon degeneration in early stages or late stages do not exist. This thesis describes the re-creation of one dynamic ultrasound elasticity imaging method and the development of an ultrasound transient shear wave elasticity imaging platform for tendon and other musculoskeletal tissue imaging. An experimental mechanical stage with proper supporting systems and accurate translating stages was designed and made. A variety of high-quality tissue-mimicking phantoms were made to simulate homogeneous and heterogeneous soft tissues as well as tendon tissues. A series of data acquisition and data processing programs were developed to collect the displacement data from the phantom and calculate the shear modulus and Young’s modulus of the target. The imaging platform was found to be capable of conducting comparative measurements of the elastic parameters of the phantoms and quantitatively mapping elasticity onto ultrasound B-Mode images. This suggests the system has great potential for not only benefiting individuals with tendinopathy with an earlier detection, intervention and better rehabilitation, but also for providing a medical tool for quantification of musculoskeletal tissue dysfunction in other regions of the body such as the shoulder, elbow and knee.

Are the severe injuries of cutaneous leishmaniasis caused by an exacerbated Th1 response?

American tegumentary leishmaniasis (ATL) is a disease whose clinical features are strongly related to the type of immune response it induces. Herein we report an atypical presentation of cutaneous leishmaniasis in a woman with a severe and extensive sore located in her leg, and we describe the differences between the usual local immune response in ATL and the local immune response in this patient. We observed an intense inflammatory response characterized by Th1 cells and cytokines with conspicuous expression of Toll-like receptor 3 (TLR-3). Few parasites were present, but there was an extensive tissue damage. We also discuss the immunological factors that could be related to the atypical presentation.

Subcutaneous Tissue Thickness is an Independent Predictor of Image Noise in Cardiac CT

Background: Few data on the definition of simple robust parameters to predict image noise in cardiac computed tomography (CT) exist. Objectives: To evaluate the value of a simple measure of subcutaneous tissue as a predictor of image noise in cardiac CT. Methods: 86 patients underwent prospective ECG-gated coronary computed tomographic angiography (CTA) and coronary calcium scoring (CAC) with 120 kV and 150 mA. The image quality was objectively measured by the image noise in the aorta in the cardiac CTA, and low noise was defined as noise < 30HU. The chest anteroposterior diameter and lateral width, the image noise in the aorta and the skin-sternum (SS) thickness were measured as predictors of cardiac CTA noise. The association of the predictors and image noise was performed by using Pearson correlation. Results: The mean radiation dose was 3.5 ± 1.5 mSv. The mean image noise in CT was 36.3 ± 8.5 HU, and the mean image noise in non-contrast scan was 17.7 ± 4.4 HU. All predictors were independently associated with cardiac CTA noise. The best predictors were SS thickness, with a correlation of 0.70 (p < 0.001), and noise in the non-contrast images, with a correlation of 0.73 (p < 0.001). When evaluating the ability to predict low image noise, the areas under the ROC curve for the non-contrast noise and for the SS thickness were 0.837 and 0.864, respectively. Conclusion: Both SS thickness and CAC noise are simple accurate predictors of cardiac CTA image noise. Those parameters can be incorporated in standard CT protocols to adequately adjust radiation exposure.

Patterning soft matter for cell culturing

In the search to understand the interaction between cells and their underlying substrates, life sciences are beginning to incorporate micro and nano-technology based tools to probe, measure and improve cellular behavior. In this frame, patterned surfaces provide a platform for highly defined cellular interactions and, in perspective, they offer unique advantages for artificial implants. For these reasons, functionalized materials have recently become a central topic in tissue engineering. Nanotechnology, with its rich toolbox of techniques, can be the leading actor in the materials patterning field. Laser assisted methods, conventional and un-conventional lithography and other patterning techniques, allow the fabrication of functional supports with tunable properties, either physically, or topographically and chemically. Among them, soft lithography provides an effective (and low cost) strategy for manufacturing micro and nanostructures. The main focus of this work is the use of different fabrication approaches aiming at a precise control of cell behavior, adhesion, proliferation and differentiation, through chemically and spatially designed surfaces.

Improving chondrogenesis: potential and limitations of SOX9 gene transfer and mechanical stimulation for cartilage tissue engineering

Articular cartilage injuries and degeneration affect a large proportion of the population in developed countries world wide. Stem cells can be differentiated into chondrocytes by adding transforming growth factor-beta1 and dexamethasone to a pellet culture, which are unfeasible for tissue engineering purposes. We attempted to achieve stable chondrogenesis without any requirement for exogenous growth factors. Human mesenchymal stem cells were transduced with an adenoviral vector containing the SRY-related HMG-box gene 9 (SOX9), and were cultured in a three-dimensional (3D) hydrogel scaffold composite. As an additional treatment, mechanical stimulation was applied in a custom-made bioreactor. SOX9 increased the expression level of its known target genes, as well as its cofactors: the long form of SOX5 and SOX6. However, it was unable to increase the synthesis of sulfated glycosaminoglycans (GAGs). Mechanical stimulation slightly enhanced collagen type X and increased lubricin expression. The combination of SOX9 and mechanical load boosted GAG synthesis as shown by (35)S incorporation. GAG production rate corresponded well with the amount of (endogenous) transforming growth factor-beta1. Finally, cartilage oligomeric matrix protein expression was increased by both treatments. These findings provide insight into the mechanotransduction of mesenchymal stem cells and demonstrate the potential of a transcription factor in stem cell therapy.

Clinical forensic radiology in strangulation victims: forensic expertise based on magnetic resonance imaging (MRI) findings

Based on only one objective and several subjective signs, the forensic classification of strangulation incidents concerning their life-threatening quality can be problematic. Reflecting that it is almost impossible to detect internal injuries of the neck with the standard forensic external examination, we examined 14 persons who have survived manual and ligature strangulation or forearm choke holds using MRI technique (1.5-T scanner). Two clinical radiologists evaluated the neck findings independently. The danger to life was evaluated based on the "classical" external findings alone and in addition to the radiological data. We observed hemorrhaging in the subcutaneous fatty tissue of the neck in ten cases. Other frequent findings were hemorrhages of the neck and larynx muscles, the lymph nodes, the pharynx, and larynx soft tissues. Based on the classical forensic strangulation findings with MRI, eight of the cases were declared as life-endangering incidents, four of them without the presence of petechial hemorrhage but with further signs of impaired brain function due to hypoxia. The accuracy of future forensic classification of the danger to life will probably be increased when it is based not only on one objective and several subjective signs but also on the evidence of inner neck injuries. However, further prospective studies including larger cohorts are necessary to clarify the value of the inner neck injuries in the forensic classification of surviving strangulation victims.

Influence of suture tension to the tearing characteristics of the soft tissues: an in vitro experiment

OBJECTIVES: To evaluate the influence of flap tension on the tearing characteristics of mucosal tissue samples in relation to various suture and needle characteristics. MATERIAL AND METHODS: Lining and masticatory mucosal tissue samples obtained from pig jaws were prepared for in vitro testing. Tension tearing diagrams of 60 experiments were traced for 3-0, 5-0 and 7-0 sutures with applied forces up to 20 N. In the second part, the same experiments were repeated with 100 diagrams to test the influence of needle characteristics with 5-0 and 6-0 sutures using only gingival tissue samples. RESULTS: 3-0 sutures mainly lead to tissue breakage at an average of 13.4 N. In contrast, 7-0 sutures only resulted in breakage of the thread at a mean applied force of 3.7 N. With 5-0 sutures, both events occurred at random at a mean force of 14.6 N. Irrespective of the needle characteristics, the mean breaking force for gingival samples with 5-0 and 6-0 sutures was approximately 10 N. CONCLUSIONS: Tissue trauma may be reduced by choosing finer suture diameters, because thinner (6-0, 7-0) sutures lead to thread breakage rather than tissue breakage.