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ABSTRACT To verify the frequency, extension, and determinant factors of thermal damage in histological sections of oral biopsies performed with surgical lasers. The area of thermal damage was determined in histological sections of oral biopsies (n=166) performed with surgical laser. The two most frequent laser types were diode laser (980nm, 1.5W, continuous mode) and CO2 laser (10600nm, 2.0 to 5.0W, continuous mode). Fibroma, inflammatory fibrous hyperplasia, and mucocele were the main anatomopathological diagnoses. In most cases (57.6%), the percentage of thermal damage area did not exceed 25% of the total area of the histological section. Diode laser exhibited a significant association (p=0.045) with a smaller thermal damage area. There was no significant association between power and wavelength with the area of thermal damage. It was not possible to determine the factors that are associated with thermal damage in histological sections of oral biopsies performed with surgical laser, because of the great variability of the irradiation parameters adopted and the various equipment types. The area of thermal damage present in the histological sections did not make the histopathological diagnosis unfeasible in most cases. This work was supported by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) [Finance Code 001]. [ABSTRACT FROM AUTHOR]

Pain accruing from nipple lesions caused by inadequate latching by the baby is a common complaint among breastfeeding women and an important obstacle to successful breastfeeding. Nipple pain occurs during the first days after delivery and is considered one of the main causes for early weaning. To investigate the efficacy of low-level laser therapy as a treatment for nipple pain due to breastfeeding. A triple-blind, randomized, clinical study. A university-affiliated hospital in São Paulo, Brazil. Fifty-nine women with nipple lesions at the time of their admission. Thirty women (intervention group) received three sessions of laser therapy (InGaAIP laser, 660 nanometer, 40 milliwatts of power, 5 Joules per square centimeter of energy density for 5 seconds each, total energy = 0.6 Joules) in the region of the nipples at three different points in time (0 hour, 24 hours, and 48 hours after diagnosis of nipple lesion). Twenty-nine women with similar clinical conditions were randomly assigned to the control group. Self-reported pain was recorded before and after laser therapy using a visual analogue scale. The intervention group experienced a decrease of 2.0 centimeters in intensity of pain ( p = .016) 24 hours after the first intervention and also presented lower levels of pain compared with the control group. Low-level laser therapy was considered effective for treating nipple lesions in breastfeeding women with pain, providing relief and prolonging exclusive breastfeeding. More clinical trials with different laser dosimetry and parameters are necessary to optimize laser therapy protocols for breastfeeding women. [ABSTRACT FROM AUTHOR]

Purpose This study analyzed the effects of injury and removal of the articular disc on maxillomandibular growth in young rats. Materials and Methods Thirty 1-month-old male Wistar rats were divided into 3 groups: injury, removal, and sham operated. Unilateral injury of the articular disc, removal of the articular disc, or only surgical access was performed. The animals were sacrificed at 3 months of age. Specimens were submitted to radiographic incidences and cephalometric mensurations were performed using a computer system. Data were subjected to statistical analyses among groups and between sides in each group. Results There were degenerative changes of the condylar process in the injury and removal groups. Significant differences between sides were observed for length of the premaxilla, height of the mandibular body, and length of the mandible. Concomitant group comparisons showed significant differences in the height of the mandibular body ( P = .003) and the length of the mandible ( P = .001). There were important decreases to the height of the mandibular body and mandibular length in the injury group, whereas there was an important decrease only for the length of the mandible in the removal group. Specific measurements of mandibular ramus structures exhibited differences between the injury and sham-operated groups and between the removal and sham-operated groups. Conclusion Experimental injury and removal of the articular disc during the growth period in rats had deleterious effects on ramus structures and induced asymmetry of the mandible, with worse outcomes resulting from injury to the articular disc. [ABSTRACT FROM AUTHOR]

Background Methotrexate (MTX) is an anti-metabolite used in rheumatology and oncology. High doses are indicated for oncological treatment, whereas low doses are indicated for chronic inflammatory diseases. This study evaluated the effect of two MTX treatment schedules on the bone healing of the temporomandibular joint fracture in rats. Methods Seventy-five adult male Wistar rats were used to generate an experimental unilateral medially rotated condylar fracture model that allows an evaluation of bone healing and the articular structures. The animals were subdivided into three groups that each received one of the following treatments intraperitoneally: saline (1 mL/week), low-dose MTX (3 mg/kg/week) and high-dose MTX (30 mg/kg). The histological study comprised fracture site and temporomandibular joint evaluations and bone neoformation was evaluated by histomorphometric analysis. A biochemical parameter of bone formation was also assessed. Results When compared with saline, high-dose MTX delayed bone fracture repairs. In this latter group, after 90 days, the histological analysis revealed atrophy of the fibrocartilage and the presence of fibrous tissue in the joint space. The histomorphometric analysis revealed diminished bone neoformation. The alkaline phosphatase levels also decreased after MTX treatment. Conclusion It was concluded that high-dose MTX impaired mandibular condyle repair and induced degenerative articular changes. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: This study evaluated the healing of mandibular condylar fracture in rats submitted to experimental and protein undernutrition (8% of protein) by means of histological analysis. Material: Forty-five adult Wistar rats were divided into three groups of 15 animals: a fracture group, who were submitted to condylar fracture with no changes in diet; an undernourished fracture group, who were submitted to a low protein diet and condylar fracture: an undernourished group, kept until the end of experiment, without condylar fracture. Displaced fractures of the right condyle were created under general anaesthesia. The histological study comprised fracture site and temporomandibular joint evaluations. Results: The undernourished fracture group showed significant weight loss. There was a marked decrease in the values of serum proteins and albumin in the undernourished fracture group. Histological analysis showed that protein undernutrition lead to atrophy of the condylar fibrocartilage. Fractures in undernutrition presented a delay in callus formation due to more extensive devitalized bone areas, and after 3 months there were still bone formation areas, while fibrous ankylosis occurred in the articular space. Conclusion: It was concluded that mandibular condyle fractures in rats with protein undernutrition had impaired callus formation, as well as fibrous ankylosis into the temporomandibular joint. [ABSTRACT FROM AUTHOR]

Highlights • p75 neurotrophin receptor (p75NTR) is a marker for cancer stem cells in head and neck cancers. • p75NTR expression was not addressed in 4-nitroquinoline 1-oxide (4-NQO)-induced oral carcinogenesis in rats. • p75NTR expression in 4-NQO-induced oral lesions is similar to that observed in head and neck cancers. • p75NTR may be useful to predict loss of cell differentiation during oral carcinogenesis. Abstract Objective The 4-nitroquinoline 1-oxide (4-NQO) model for carcinogenesis has been used to investigate cancer stem cells (CSC), but no study has addressed the role of the p75 neurotrophin receptor (p75NTR) in 4-NQO-induced oral dysplasia and oral squamous cell carcinoma (OSCC). The aim of this study was to evaluate the immunohistochemistry profile of the p75NTR during 4-NQO-induced oral carcinogenesis in rats and to verify whether this profile has an association with proliferating cell nuclear antigen (PCNA) immunolabeling. Design For 28 weeks, rats were exposed to 4-NQO, which was diluted in the drinking water. After 3, 5, 7, 16, and 28 weeks, the animals were euthanized and their tongues were histologically analyzed using p75NTR and PCNA immunolabeling. Results In animals without 4-NQO exposure, the p75NTR and PCNA were expressed only in the basal epithelial layer and in a clustered manner. The oral epithelium showed dysplasia and a significant increase in the number of p75NTR- and PCNA-positive cells, which were localized mainly in the basal and suprabasal epithelial layers during weeks 5–16 of 4-NQO exposure. When the epithelium invaded the lamina propria and well-differentiated OSCC began, the p75NTR-positive cell frequency drastically decreased in epithelial cords and nests, showing a negative correlation with PCNA expression. p75NTR immunolabeling during 4-NQO-induced carcinogenesis was similar to that described for human head and neck dysplasia and neoplasia. Conclusions p75NTR immunolabeling observed in 4-NQO-induced oral dysplastic and OSCC lesions were related to the early phases of oral carcinogenesis and may help predict cell dysplasia and malignant transformation. [ABSTRACT FROM AUTHOR]

• RST personality factors are associated with many outcomes of eating behavior. • We parsed the relationship between RST and eating behavior measures. • The association between BMI and reward sensitivity is not linear. • Punishment sensitivity seems specifically related to eating pathology symptoms. • Reward sensitivity correlates with eating phenotypes and reactivity to food cues. The Reinforcement Sensitivity Theory (RST) is a widely studied psychobiological model of personality. RST factors seem to influence eating behavior, but how these personality traits are associated with distinct features of eating behavior is still unclear. In the present systematic review, we analyzed the relationship between RST personality factors and eating behavior using a parsing approach in which BMI-related results, self-reported results, and behavioral results were distinguished. Our analysis revealed that reward and punishment sensitivity seem to correlate and influence distinct features of eating behavior. The association between BMI and RST factors was uncertain, but nonlinear associations between reward sensitivity and weight need further testing. Reward sensitivity was linked to most eating behavior phenotypes (e.g., emotional eating and restrained eating), but only punishment sensitivity was primarily correlated with eating pathology. Reward sensitivity was the main factor linked with reactivity to food stimuli on many behavioral measures. The neurobiological personality factors of RST offer parsimonious concepts to understand eating behavior outcomes and the differential relationships observed are useful to translational research. [ABSTRACT FROM AUTHOR]

During conditioning of hematopoietic stem cell transplantation, numerous chemotherapeutics are used, among them, busulfan (BU). This is an alkylating agent that generates intense toxicity induced by oxidative stress, which can lead to DNA damage and cause oral mucositis (MO). BU is found at salivary levels close to plasma levels, but it is not known whether salivary concentrations are toxic as much as plasma to the oral cavity. This work aimed to analyze oxidative stress and possible DNA damage in keratinocytes exposed to BU found in salivary doses. Human keratinocytes were cultured and the following groups were established: Control (no treatment), Control Saliva (exposure to artificial saliva) and BU (exposure to BU carried in saliva at 4.0, 4.5, 5.0 and 5.5 μg / mL). The cell viability and the number of cells with DNA fragmentation were evaluated by TUNEL assay, as well as the level of oxidative stress by quantification of sequestration of the radical DPPH, superoxide dismutase (SOD), catalase (CAT) and level of lipid peroxidation (PL). Through the comet assay, the percentage of fragmented DNA was evaluated. The effect of BU on keratinocytes was dose-dependent; the dose of 5.5 μg / mL without vehicle with saliva generated 76% cellular viability, differing from the Control group (p < 0.05); when the BU was delivered in saliva, all doses generated less viability than the BU without saliva (p < 0.001). In the TUNEL analysis, salivary BU treatment caused a higher frequency of cells with DNA fragmentation (p < 0.05 compared to controls), as well as lower sequestration potential of the DPPH radical (p < 0.05 compared to the controls). Catalase activity was higher in the BU group (p < 0.01 compared to the controls). Exposure to BU also generated a higher percentage of fragmented DNA (p < 0.05 compared to Control). It was concluded that the salivary concentration of BU is toxic to keratinocytes, inducing oxidative stress and increased DNA damage. [ABSTRACT FROM AUTHOR]

• Keratins expression is related to keratinocytes proliferation and differentiation. • K10 and K14 are commonly expressed in keratinized gingiva tissue, but K19 not. • Primary human gingival keratinocytes express K19 in vitro, but not in ex-vivo. • Primary culture of gingiva changes the native keratin network of the keratinocytes. To investigate whether the process of primary gingival keratinocytes culture obtained from normal human gingiva modifies the expression of keratins (K) 10, K14, and K19. Human gingival fragments were collected from healthy individuals in the same oral site. One part of the samples underwent an immunohistochemistry assay for K10, K14, and K19. The labeling in the epithelium was quantified using a semiautomated method. Another part was used for primary gingival keratinocytes isolation and growth in two-dimensional culture. These cells were also stained for K10, K14, and K19 using immunofluorescence and immunocytochemistry. Positive cells were counted, and the nuclei and cytoplasmatic labeling areas were quantified. In the gingival tissue, a higher expression was found for K14 versus K10 (p < 0.001); K19 was negative in all samples. In gingival keratinocytes culture, K14 (89.6 %) had the highest expression with significant differences in relation to K10 (76.9 %, p < 0.01) and K19 (9.9 %, p < 0.01). The cells positive for K14 exhibited larger nuclei in comparison with K10 (p < 0.05) and K19 (p < 0.05), suggesting a more undifferentiated phenotype. K19 cells showed the largest cytoplasmatic labeling in relation to K10- (p < 0.05) and K14-positive (p < 0.05) cells. The process of growth in culture of gingival keratinocytes maintained the expression pattern of K10 and K14 observed in gingival tissues. However, this method induces the expression of K19, suggesting a potential transformation of the keratin network presented in the gingival keratinocytes during the formation of a monolayer in vitro. This reflects the dynamics of cell differentiation. [ABSTRACT FROM AUTHOR]

Taste changes during hematopoietic steam cells transplantation (HSC) are often acknowledged after the transplantation, however little is known about which flavors and what types of perception changes are experienced by patients during this treatment. The aim of this study was to characterize taste and taste buds atrophy alterations present during the HSC, as well as to verify if there is association among these alterations and clinical variables related to the transplant and oral mucosal toxicity. The impact of taste and oral mucosa alterations on patients' quality of life was also evaluated. We selected 54 patients holding autologous and allogenic HSC, who underwent taste acuity tests prior to conditioning (T0), during neutropenia (T1) and engraftment (T2). It was carried out an acuity test in the perception of sweet, bitter, sour and salty flavors, offered in solutions containing low and high concentrations of watery substances stimulating these flavors. Patients were also submitted to oroscopy for evaluation of oral mucositis and taste buds atrophy. It was found that 69% of patients suffered taste alteration in T1 and 70% in T2. Also flavor intensity was wrongly reported more times by patients in T1 (79%) and T2 (78%) than prior to conditioning. Taste buds atrophy was observed in 74% of patients at T1 and 78% at T2, being correlated to change in the flavor (p = 0.037) at T2. Taste buds atrophy was inversely correlated to TBI treatment in their conditioning, with 42% of patients affected (p = 0.036). Finally, patients suffering mucositis for 7 days or longer presented more taste buds atrophy (p = 0.048).Conclusion: The oral mucositis duration, the conditioning regime and taste buds atrophy are factors that may be associated with greater taste alteration in patients submitted to HSC. [ABSTRACT FROM AUTHOR]