Multiscale imaging and quantitative analysis of plasma membrane protein-cortical actin interplay.

The spatiotemporal organization of cell surface receptors is important for cell signaling. Cortical actin (CA), the subset of the actin cytoskeleton subjacent to the plasma membrane (PM), plays a large role in cell surface receptor organization. However, this has been shown largely through actin perturbation experiments, which raise concerns of nonspecific effects and preclude quantification of actin architecture and dynamics under unperturbed conditions. These limitations make it challenging to predict how changes in CA properties can affect receptor organization. To derive direct relationships between the architecture and dynamics of CA and the spatiotemporal organization of PM proteins, including cell surface receptors, we developed a multiscale imaging and computational analysis framework based on the integration of single-molecule imaging (SMI) of PM proteins and fluorescent speckle microscopy (FSM) of CA (combined: SMI-FSM) in the same live cell. SMI-FSM revealed differential relationships between PM proteins and CA based on the PM proteins' actin binding ability, diffusion type, and local CA density. Combining SMI-FSM with subcellular region analysis revealed differences in CA dynamics that were predictive of differences in PM protein mobility near ruffly cell edges versus closer to the cell center. SMI-FSM also highlighted the complexity of cell-wide actin perturbation, where we found that global changes in actin properties caused by perturbation were not necessarily reflected in the CA properties near PM proteins, and that the changes in PM protein properties upon perturbation varied based on the local CA environment. Given the widespread use of SMI as a method to study the spatiotemporal organization of PM proteins and the versatility of SMI-FSM, we expect it to be widely applicable to enable future investigation of the influence of CA architecture and dynamics on different PM proteins, especially in the context of actin-dependent cellular processes.

Brazilian Society of Surgical Oncology: Guidelines for the management of anal canal cancer.

BACKGROUND: Anal canal squamous cell carcinoma (SCC) is a relatively uncommon neoplasia, and it is mostly a local-regional cancer, of low metastatic potential (only 15%), resulting in cure in most cases treated with definitive chemoradiation. On the other hand, its incidence has been steadily increasing over the last decades, which makes it an important public health problem. In an effort to provide surgeons and oncologists who treat patients with anal cancer with the most updated information based on the best scientific evidence, the Brazilian Society of Surgical Oncology (SBCO) has produced the present guideline for the management of anal canal SCC, focused on the main topics related to daily clinical practice. OBJECTIVES: The SBCO developed the present guidelines to provide recommendations on the main topics related to the management of anal canal squamous cell carcinoma (SCC) based on current scientific evidence. METHODS: Between October 2022 and January 2023, 14 experts met to develop the guidelines for the management of anal canal cancer. A total of 30 relevant topics were distributed among the participants. The methodological quality of a final list with 121 sources was evaluated, all the evidence was examined and revised, and the management guidelines were formulated by the 14-expert committee. To reach a final consensus, all the topics were reviewed in a meeting that was attended by all the experts. RESULTS: The proposed guidelines contained 30 topics considered to be highly relevant in the management of anal canal cancer, covering subjects related to screening recommendations, preventive measures, tests required for diagnosing and staging, treatment strategies, response assessment after chemoradiotherapy, surgical technique-related aspects, and follow-up recommendations. In addition, screening and response assessment algorithms, and a checklist were proposed to summarize the important information and offer an updated tool to assist surgeons and oncologists who treat anal canal cancer and in providing the best care to their patients. CONCLUSION: These guidelines summarize recommendations based on the most current scientific evidence on relevant aspects of anal canal cancer management and are a practical guide to help surgeons and oncologists who treat anal canal cancer make the best therapeutic decisions.

Cancer risk-reducing surgery: Brazilian society of surgical oncology guideline part 1 (gynecology and breast).

BACKGROUND: Risk-reducing operations are an important part of the management of hereditary predisposition to cancer. In selected cases, they can considerably reduce the morbidity and mortality associated with cancer in this population. OBJECTIVES: The Brazilian Society of Surgical Oncology (BSSO) developed this guideline to establish national benchmarks for cancer risk-reducing operations. METHODS: The guideline was prepared from May to December 2021 by a multidisciplinary team of experts to discuss the surgical management of cancer predisposition syndromes. Fourteen questions were defined and assigned to expert groups that reviewed the literature and drafted preliminary recommendations. Following a review by the coordinators and a second review by all participants, the groups made final adjustments, classified the level of evidence, and voted on the recommendations. RESULTS: For all questions including risk-reduction bilateral salpingo-oophorectomy, hysterectomy, and mastectomy, major agreement was achieved by the participants, always using accessible alternatives. CONCLUSION: This and its accompanying article represent the first guideline in cancer risk reduction surgery developed by the BSSO, and it should serve as an important reference for the management of families with cancer predisposition.

Cancer risk-reducing surgery: Brazilian Society of Surgical Oncology Guideline Part 2 (Gastrointestinal and thyroid).

BACKGROUND: Risk-reducing operations are an important part of the management of hereditary predisposition to cancer. In selected cases, they can considerably reduce the morbidity and mortality associated with cancer in this population. OBJECTIVES: The Brazilian Society of Surgical Oncology (BSSO) developed this guideline to establish national benchmarks for cancer risk-reducing operations. METHODS: The guideline was prepared from May to December 2021 by a multidisciplinary team of experts to discuss the surgical management of cancer predisposition syndromes. Eleven questions were defined and assigned to expert groups that reviewed the literature and drafted preliminary recommendations. Following a review by the coordinators and a second review by all participants, the groups made final adjustments, classified the level of evidence, and voted on the recommendations. RESULTS: For all questions including risk-reducing colectomy, gastrectomy, and thyroidectomy, a major agreement was achieved by the participants, always using accessible alternatives. CONCLUSION: This and its accompanying article represent the first guideline in cancer risk reduction surgery developed by the BSSO and it should serve as an important reference for the management of families with cancer predisposition.

Guidelines of the Brazilian Society of Oncologic Surgery for pelvic exenteration in the treatment of cervical cancer.

BACKGROUND AND OBJECTIVES: The primary treatment for locally advanced cases of cervical cancer is chemoradiation followed by high-dose brachytherapy. When this treatment fails, pelvic exenteration (PE) is an option in some cases. This study aimed to develop recommendations for the best management of patients with cervical cancer undergoing salvage PE. METHODS: A questionnaire was administered to all members of the Brazilian Society of Surgical Oncology. Of them, 68 surgeons participated in the study and were divided into 10 working groups. A literature review of studies retrieved from the National Library of Medicine database was carried out on topics chosen by the participants. These topics were indications for curative and palliative PE, preoperative and intraoperative evaluation of tumor resectability, access routes and surgical techniques, PE classification, urinary, vaginal, intestinal, and pelvic floor reconstructions, and postoperative follow-up. To define the level of evidence and strength of each recommendation, an adapted version of the Infectious Diseases Society of America Health Service rating system was used. RESULTS: Most conducts and management strategies reviewed were strongly recommended by the participants. CONCLUSIONS: Guidelines outlining strategies for PE in the treatment of persistent or relapsed cervical cancer were developed and are based on the best evidence available in the literature.

In-House Digital Workflow for the Management of Acute Mandible Fractures.

Computer-aided design and additive manufacturing are revolutionizing oral and maxillofacial surgery. Current methods use virtual surgical planning sessions and custom plate milling via third-party vendors, which is costly and time-consuming, negating the effectiveness in acute facial trauma. This technical note describes a state-of-the-art in-house expedited digital workflow for computer-aided virtual fracture reduction, 3-dimensional printing, and preoperative reconstruction plate adaptation for the management of an acute mandible fracture. This process uses the computed tomographic scan a patient receives in the emergency department or clinic. The DICOM (Digital Imaging and Communications in Medicine) data are transferred into US Food and Drug Administration-approved software, in which the fracture is segmented and virtually reduced based on condylar position, midline symmetries, and occlusion if present. The reduced mandible is then printed, which serves as a template for preoperative reconstruction plate adaptation. This method facilitates a virtually reduced fractured mandible, 3-dimensionally printed model, and ideally adapted plates ready for sterilization before surgery within 2 hours after DICOM upload.

Integrating hinge axis approximation and the virtual facial simulation of prosthetic outcomes for treatment with CAD-CAM immediate dentures: A clinical report of a patient with microstomia.

This clinical report describes a digital workflow using extraoral digital photographs and volumetric datasets from cone beam computed tomography (CBCT) imaging to create a 3-dimensional (3D), virtual patient with photorealistic appearance. In a patient with microstomia, hinge axis approximation, diagnostic casts simulating postextraction alveolar ridge profile, and facial simulation of prosthetic treatment outcome were completed in a 3D, virtual environment. The approach facilitated the diagnosis, communication, and patient acceptance of the treatment of maxillary and mandibular computer-aided design and computer-aided manufacturing (CAD-CAM) of immediate dentures at increased occlusal vertical dimension.

Apical root resorption during orthodontic treatment with clear aligners: A retrospective study using cone-beam computed tomography.

INTRODUCTION: We aimed to investigate the incidence and severity of orthodontically induced inflammatory root resorption (OIIRR) on maxillary incisors with clear aligner therapy using cone-beam computed tomography and to identify possible risk factors. METHODS: The root lengths of maxillary incisors were measured on orthogonal images from pretreatment and posttreatment cone-beam computed tomography examinations of 160 patients who received comprehensive orthodontic treatment with clear aligners. RESULTS: Mean absolute reductions in root length varied between 0.47 ± 0.61 mm and 0.55 ± 0.70 mm and were not significantly different between maxillary central and lateral incisors. The prevalence of severe OIIRR, defined as both maxillary central incisors experiencing greater than a 25% reduction in root length, was found to be 1.25%. Potential risk factors included sex, malocclusion, crowding, and posttreatment approximation of apices to the cortical plates. Race, interproximal reduction, previous trauma to the teeth, elastics, age, treatment duration, and pretreatment approximation of apices to the cortical plates did not significantly affect the amount of OIIRR. CONCLUSIONS: Comprehensive treatment with clear aligners resulted in minimal root resorption. Sex, malocclusion, crowding, and posttreatment approximation to the cortical plates significantly affected the percentage of change in root length. Posttreatment approximation of root apices to the palatal cortical plate showed the strongest association for increased OIIRR.

The emerging role of maxillofacial radiology in the diagnosis and management of patients with complex periodontitis.

Contemporary periodontal therapy has evolved to become more interdisciplinary and increasingly involves more complex treatments, including bone and soft-tissue regenerative procedures. Therapeutic options require an imaging modality or combination of techniques that are capable of providing a diagnostic osseous baseline and facilitating quantification of smaller increments of bony change, both loss and additive, which are comparable over time. Intra-oral and panoramic radiography are the modalities most commonly used to identify the location, quantify the amount and the pattern of alveolar bone loss and determine response to therapy. Cone-beam computed tomography imaging offers specific advantages for periodontal diagnosis in that three-dimensional images of dental and alveolar bone structures can be rendered with accuracy. Cone-beam computed tomography has been shown to be clinically efficacious in demonstrating localized defects, such as furcation involvement and intrabony vertical and buccal/lingual defects, and in assessing the effects of regenerative therapy. In these situations, limited-field-of-view, high-resolution protocols are indicated.

Fibroblast morphogenesis on 3D collagen matrices: the balance between cell clustering and cell migration.

Fibroblast clusters have been observed in tissues under a variety of circumstances: in fibrosis and scar, in the formation of hair follicle dermal papilla, and as part of the general process of mesenchymal condensation that takes place during development. Cell clustering has been shown to depend on features of the extracellular matrix, growth factor environment, and mechanisms to stabilize cell-cell interactions. In vitro studies have shown that increasing the potential for cell-cell adhesion relative to cell-substrate adhesion promotes cell clustering. Experimental models to study fibroblast clustering have utilized centrifugation, hanging drops, and substrata with poorly adhesive, soft and mechanically unstable properties. In this review, we summarize work on a new, highly tractable, cell clustering research model in which human fibroblasts are incubated on the surfaces of collagen matrices. Fibroblast clustering occurs under procontractile growth factor conditions (e.g., serum or the serum lipid agonist lysophosphatidic acid) but not under promigratory growth factor conditions (e.g., platelet-derived growth factor) and can be reversed by switching growth factor environments. Cell contraction plays a dual role in clustering to bring cells closer together and to stimulate cells to organize fibronectin into a fibrillar matrix. Binding of fibroblasts to a shared fibronectin fibrillar matrix stabilizes clusters, and fragmentation of the fibrillar matrix occurs when growth factor conditions are switched to promote cell dispersal.

Fibroblast cluster formation on 3D collagen matrices requires cell contraction dependent fibronectin matrix organization.

Fibroblasts incubated on 3D collagen matrices in serum or lysophosphatidic acid (LPA)-containing medium self-organize into clusters through a mechanism that requires cell contraction. However, in platelet-derived growth factor (PDGF)-containing medium, cells migrate as individuals and do not form clusters even though they constantly encounter each other. Here, we present evidence that a required function of cell contraction in clustering is formation of fibronectin (FN) fibrillar matrix. We found that in serum or LPA but not in PDGF or basal medium, cells organized FN (both serum and cellular) into a fibrillar, detergent-insoluble matrix. Cell clusters developed concomitant with FN matrix formation. FN fibrils accumulated beneath cells and along the borders of cell clusters in regions of cell-matrix tension. Blocking Rho kinase or myosin II activity prevented FN matrix assembly and cell clustering. Using siRNA silencing and function-blocking antibodies and peptides, we found that cell clustering and FN matrix assembly required α5ß1 integrins and fibronectin. Cells were still able to exert contractile force and compact the collagen matrix under the latter conditions, which showed that contraction was not sufficient for cell clustering to occur. Our findings provide new insights into how procontractile (serum/LPA) and promigratory (PDGF) growth factor environments can differentially regulate FN matrix assembly by fibroblasts interacting with collagen matrices and thereby influence mesenchymal cell morphogenetic behavior under physiologic circumstances such as wound repair, morphogenesis and malignancy.

Maxillary Dental Anatomy and Physiology: Endodontic and Periodontal.

The maxillary sinus floor is formed by the alveolar process of the maxilla. Frequently, the roots of maxillary molars and premolars may protrude into the sinus cavity, with only a thin membrane separating them. Endodontic infections are characterized by mixed biofilms of anaerobic and proteolytic bacteria that can infect the root canal space and accessory anatomy of those teeth producing apical periodontitis. Due to the close relationship with the maxillary sinus, the persistence of apical periodontitis could potentially lead to odontogenic sinusitis. Understanding maxillary sinus anatomy and its relationship with the posterior maxillary dentition is crucial for diagnosing this entity.

Stress Load and Ascending Aortic Aneurysms: An Observational, Longitudinal, Single-Center Study Using Computational Fluid Dynamics.

Ascending aortic aneurysm (AAoA) is a silent disease with high mortality; however, the factors associated with a worse prognosis are not completely understood. The objective of this observational, longitudinal, single-center study was to identify the hemodynamic patterns and their influence on AAoA growth using computational fluid dynamics (CFD), focusing on the effects of geometrical variations on aortic hemodynamics. Personalized anatomic models were obtained from angiotomography scans of 30 patients in two different years (with intervals of one to three years between them), of which 16 (53%) showed aneurysm growth (defined as an increase in the ascending aorta volume by 5% or more). Numerically determined velocity and pressure fields were compared with the outcome of aneurysm growth. Through a statistical analysis, hemodynamic characteristics were found to be associated with aneurysm growth: average and maximum high pressure (superior to 100 Pa); average and maximum high wall shear stress (superior to 7 Pa) combined with high pressure (>100 Pa); and stress load over time (maximum pressure multiplied by the time interval between the exams). This study provides insights into a worse prognosis of this serious disease and may collaborate for the expansion of knowledge about mechanobiology in the progression of AAoA.

Influence of probiotic supplementation on parasitological parameters in lambs.

The control of parasitosis is based on the use of anthelmintics. However, its long-term and indiscriminate use can select populations of resistant nematodes. New alternatives such as probiotics are being studied to solve this problem. This study aimed to investigate the effects of an oral probiotic containing six different bacterial strains and the yeast Saccharomyces cerevisiae on the blood biochemistry, parasitological, and histological parameters of naturally infected lambs. Forty-two weaned Texel or Ile de France crossbred lambs aged 86.9 ± 8.0 days and weighing 27.4 ± 3.7 kg were randomly allocated into three groups (n = 14 lambs). The control group (CG) was fed a basal diet without probiotic supplementation. The treatment group 1 g (T1G) was fed a basal diet with commercial probiotic supplementation at a dose of 1 g/lamb/day. The treatment group 5 g (T5G) was fed a basal diet with commercial probiotic supplementation at a dose of 5 g/lamb/day. The experimental period was 84 days, where the groups undergo mild natural infection. Every two weeks the hematocrit, total protein, albumin, globulin, fibrinogen, plasma protein, fecal egg count (FEC), and fecal consistency score were evaluated. Twenty lambs were slaughtered for histological evaluation of the rumen and abomasal wall and for counting abomasal nematodes. The area, length, and number of eggs from the recovered Haemonchus contortus female uteri were measured. Data were analyzed using analysis of variance (ANOVA) and Tukey's test (p ≤ 0.05). The area and length of Haemonchus contortus females from T1G were smaller (p < 0.01) than those of CG and T5G. The number of eggs from the H. contortus female uterus was lower (p < 0.01) in T1G and T5G. Evaluating the incidence of diarrhea, the T1G and T5G groups had a higher prevalence with a 35% and 39% score of zero, respectively (p < 0.05), while the CG group had 22%. All other evaluated parameters showed no significant differences (p > 0.05) between the groups. The probiotic had a beneficial effect on the gastrointestinal health of the weaned lambs through a decrease of the area, length, and the number of eggs of female H. contortus and an improvement in fecal consistency.

Multiscale imaging and quantitative analysis of plasma membrane protein-cortical actin interplay.

The spatiotemporal organization of cell surface receptors is important for cell signaling. Cortical actin (CA), the subset of the actin cytoskeleton subjacent to the plasma membrane (PM), plays a large role in cell surface receptor organization. This was however shown largely through actin perturbation experiments, which raise concerns of nonspecific effects and preclude quantification of actin architecture and dynamics under unperturbed conditions. These limitations make it challenging to predict how changes in CA properties can affect receptor organization. To derive direct relationships between the architecture and dynamics of CA and the spatiotemporal organization of PM proteins, including cell surface receptors, we developed a multiscale imaging and computational analysis framework based on the integration of single-molecule imaging (SMI) of PM proteins and fluorescent speckle microscopy (FSM) of CA (combined: SMI-FSM) in the same live cell. SMI-FSM revealed differential relationships between PM proteins and CA based on the PM proteins’ actin binding ability, diffusion type and local CA density. It also highlighted the complexity of cell wide actin perturbation, where we found that global changes in actin properties caused by perturbation were not necessarily reflected in the CA properties near PM proteins, and the changes in PM protein properties upon perturbation varied based on the local CA environment. Given the widespread use of SMI as a method to study the spatiotemporal organization of PM proteins and the versatility of SMI-FSM, we expect it to be widely applicable to enable future investigation of the influence of CA architecture and dynamics on different PM proteins, especially in the context of actin-dependent cellular processes, such as cell migration. Significance: Plasma membrane protein organization, an important factor for shaping cellular behaviors, is influenced by cortical actin, the subset of the actin cytoskeleton near the plasma membrane. Yet it is challenging to directly and quantitatively probe this influence. Here, we developed an imaging and analysis approach that combines single-molecule imaging, fluorescent speckle microscopy and computational statistical analysis to characterize and correlate the spatiotemporal organization of plasma membrane proteins and cortical actin. Our approach revealed different relationships between different proteins and cortical actin, and highlighted the complexity of interpreting cell wide actin perturbation experiments. We expect this approach to be widely used to study the influence of cortical actin on different plasma membrane components, especially in actin-dependent processes.

Pathogenic Naegleria fowleri and non-pathogenic Naegleria lovaniensis exhibit differential adhesion to, and invasion of, extracellular matrix proteins.

Naegleria fowleri and Naegleria lovaniensis are closely related free-living amoebae found in the environment. N. fowleri causes primary amoebic meningoencephalitis (PAM), a rapidly fatal disease of the central nervous system, while N. lovaniensis is non-pathogenic. N. fowleri infection occurs when the amoebae access the nasal passages, attach to the nasal mucosa and its epithelial lining, and migrate to the brain. This process involves interaction with components of the host extracellular matrix (ECM). Since the ability to invade tissues can be a characteristic that distinguishes pathogenic from non-pathogenic amoebae, the objective of this study was to assess adhesion to, and invasion of, the ECM by these two related but distinct Naegleria species. N. fowleri exhibited a higher level of adhesion to the ECM components laminin-1, fibronectin and collagen I. Scanning electron microscopy revealed that N. fowleri attached on ECM substrata exhibited a spread-out appearance that included the presence of focal adhesion-like structures. Western immunoblotting revealed two integrin-like proteins for both species, but one of these, with a molecular mass of approximately 70 kDa, was detected at a higher level in N. fowleri. Confocal microscopy indicated that the integrin-like proteins co-localized to the focal adhesion-like structures. Furthermore, anti-integrin antibody decreased adhesion of N. fowleri to ECM components. Finally, N. fowleri disrupted 3D ECM scaffolds, while N. lovaniensis had a minimal effect. Collectively, these results indicate a distinction in adhesion to, and invasion of, ECM proteins between N. fowleri and N. lovaniensis.

Analysis of conditional colocalization relationships and hierarchies in three-color microscopy images.

Colocalization analysis of multicolor microscopy images is a cornerstone approach in cell biology. It provides information on the localization of molecules within subcellular compartments and allows the interrogation of known molecular interactions in their cellular context. However, almost all colocalization analyses are designed for two-color images, limiting the type of information that they reveal. Here, we describe an approach, termed "conditional colocalization analysis," for analyzing the colocalization relationships between three molecular entities in three-color microscopy images. Going beyond the question of whether colocalization is present or not, it addresses the question of whether the colocalization between two entities is influenced, positively or negatively, by their colocalization with a third entity. We benchmark the approach and showcase its application to investigate receptor-downstream adaptor colocalization relationships in the context of functionally relevant plasma membrane locations. The software for conditional colocalization analysis is available at https://github.com/kjaqaman/conditionalColoc.

Frequency and Risk Factors of Maxillary Sinusitis of Endodontic Origin Evaluated by a Dynamic Navigation and a New Filter of Cone-Beam Computed Tomography.

INTRODUCTION: The aim of this study was to determine the frequency and risk factors of maxillary sinusitis of endodontic origin (MSEO) on posterior maxillary teeth evaluated using dynamic navigation and a novel filter of cone-beam computed tomographic (CBCT) imaging. METHODS: CBCT scans of 453 patients (814 teeth) were selected. Data were divided into 4 groups: (1) root canal treatment (RCT), (2) relation of the root apex to the maxillary sinus, (3) apical periodontitis (AP), and (4) maxillary sinus inflammation (no inflammation, periapical osteoperiostitis, periapical mucositis, partial obstruction, or total obstruction). Frequency distribution and cross-tabulation were used for data analysis. The association of maxillary sinus abnormalities with other variables was analyzed using the chi-square test. The significance level was set at 5%, and the association between dependent and independent variables was analyzed using robust Poisson regression models. RESULTS: MSEO was found in 65.6% of the cases, and the highest frequency rates were in the periapical mucositis (44%) and partial obstruction (15.8%) groups. The rates of risk factors were highest in the cases of RCT (54.9%), AP (34.3%), and the root apex in contact with the maxillary sinus (53.8%). The most frequent sex and age group were female (55.8%) and 41-50 years (30.5%). CONCLUSIONS: The frequency of MSEO was high and positively associated with RCT, AP, and the root apex's position in contact with the floor of the maxillary sinus. The maxillary sinus filter of the CBCT software provides a clear image of maxillary sinus abnormalities.

Therapeutic effect of oral quercetin in hamsters infected with Leishmania Viannia braziliensis.

Leishmaniasis is a parasitic disease caused by several species of intracellular protozoa of the genus Leishmania that present manifestations ranging from cutaneous ulcers to the fatal visceral form. Leishmania Viannia braziliensis is an important species associated with American tegumentary leishmaniasis and the main agent in Brazil, with variable sensitivity to available drugs. The search for new therapeutic alternatives to treat leishmaniasis is an urgent need, especially for endemic countries. Not only is quercetin well known for its antioxidant activity in radical scavenging but also several other biological effects are described, including anti-inflammatory, antimicrobial, and pro-oxidant activities. This study aimed to investigate the flavonoid quercetin's therapeutic potential in L. (V.) braziliensis infection. Quercetin showed antiamastigote (IC50 of 21 ± 2.5 µM) and antipromastigote (25 ± 0.7 µM) activities and a selectivity index of 22. The treatment of uninfected or L. (V.) braziliensis-infected macrophages with quercetin increased reactive oxygen species (ROS)/H202 generation without altering Nitric Oxide (NO) production. Oral treatment with quercetin of infected hamsters, starting at 1 week of infection for 8 weeks, reduced the lesion thickness (p > 0.01) and parasite load (p > 0.001). The results of this study suggest that the antiamastigote activity of the flavonoid quercetin in vitro is associated, at least in part, with the modulation of ROS production by macrophages. The efficacy of oral quercetin treatment in hamsters infected with L. (V.) braziliensis was presented for the first time and shows its promising therapeutic potential.

A Critical Review of the Differential Diagnosis of Root Fracture Line in CBCT scans.

The objective of this critical review of literature is to discuss relevant clinical factors associated with root fractures (RF) visualized by using a new CBCT software. RF constitutes a common occurrence and a challenge in clinical practice, in which the diagnosis becomes essential for the definition of rapid and precise decision-making. The characterization of RF may involve different aspects, such as orientation of the fracture line (horizontal, vertical, oblique), root position of the fracture (cervical, middle, apical third), fracture's coronal-radicular position (coronary, coronal-radicular, radicular), continuity of the fracture (crack, incomplete fracture, complete), bone extension of the fracture (supraosseous, bone level, infraosseous fracture). Imaging examinations have been routinely used to aid in the RF diagnosis. Even with high-resolution cone-beam computed tomography (CBCT) scans, many doubts often remain about the diagnostic outcome. Many interferences in the analysis of image quality to determine the diagnosis are identified, such as the sharpness, the noise, light and dark artifacts, among others. The professional's knowledge is essential for identifying the different patterns of fracture lines and their repercussions on adjacent bone tissues, as well as for the analysis of artifacts that may hide or show similarities to fracture lines. Fractures lines and root fractures that may be associated with phantom conditions that mimic fractures should be carefully analyzed. CBCT is the exam indicated to identify a root fracture. It is also added to the success of the diagnosis that the professional has scientific knowledge, training and mastery of advanced CBCT software.