Metabolic Changes In Masseter Muscle Of Rats Submitted To Acute Stress Associated With Exodontia

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Clinical evidence has shown that stress may be associated with alterations in masticatory muscle functions. Morphological changes in masticatory muscles induced by occlusal alterations and associated with emotional stress are still lacking in the literature. The objective of this study was to evaluate the influence of acute stress on metabolic activity and oxidative stress of masseter muscles of rats subjected to occlusal modification through morphological and histochemical analyses. In this study, adult Wistar rats were divided into 4 groups: a group with extraction and acute stress (E+A); group with extraction and without stress (E+C); group without extraction and with acute stress (NO+A); and control group without both extraction and stress (NO+C). Masseter muscles were analyzed by Succinate Dehydrogenase (SDH), Nicotinamide Adenine Dinucleotide Diaphorase (NADH) and Reactive Oxygen Species (ROS) techniques. Statistical analyses and two-way ANOVA were applied, followed by Tukey-Kramer tests. In the SDH test, the E+C, E+A and NO+A groups showed a decrease in high desidrogenase activities fibers (P < 0.05), compared to the NO+C group. In the NADH test, there was no difference among the different groups. In the ROS test, in contrast, E+A, E+C and NO+A groups showed a decrease in ROS expression, compared to NO+C groups (P < 0.05). Modified dental occlusion and acute stress - which are important and prevalent problems that affect the general population - are important etiologic factors in metabolic plasticity and ROS levels of masseter muscles.106Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP [2011/00856-7, 2011/15209-7, 2011/18889-9

Metabolic changes in masseter muscle of rats submitted to acute stress associated with exodontia

Clinical evidence has shown that stress may be associated with alterations in masticatory muscle functions. Morphological changes in masticatory muscles induced by occlusal alterations and associated with emotional stress are still lacking in the literature. The objective of this study was to evaluate the influence of acute stress on metabolic activity and oxidative stress of masseter muscles of rats subjected to occlusal modification through morphological and histochemical analyses. In this study, adult Wistar rats were divided into 4 groups: a group with extraction and acute stress (E+A); group with extraction and without stress (E+C); group without extraction and with acute stress (NO+A); and control group without both extraction and stress (NO+C). Masseter muscles were analyzed by Succinate Dehydrogenase (SDH), Nicotinamide Adenine Dinucleotide Diaphorase (NADH) and Reactive Oxygen Species (ROS) techniques. Statistical analyses and two-way ANOVA were applied, followed by Tukey-Kramer tests. In the SDH test, the E+C, E+A and NO+A groups showed a decrease in high desidrogenase activities fibers (P < 0.05), compared to the NO+C group. In the NADH test, there was no difference among the different groups. In the ROS test, in contrast, E+A, E+C and NO+A groups showed a decrease in ROS expression, compared to NO+C groups (P < 0.05). Modified dental occlusion and acute stress - which are important and prevalent problems that affect the general population - are important etiologic factors in metabolic plasticity and ROS levels of masseter muscles106FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP2011/00856-7; 2011/15209-7; 2011/18889-

Sintomas de ansiedade e depressão em pessoas com doença de parkinson durante a pandemia de Covid-19

A Doença de Parkinson (DP) é uma doença neurodegenerativa progressiva, com sintomas motores e não motores. O quadro clínico do paciente com DP pode ser gravemente influenciado por circunstâncias geradores de estresse, como o isolamento social decorrente da pandemia. Foi realizado um estudo transversal no município de Presidente Prudente, São Paulo, em 2022, com o objetivo de avaliar a prevalência de sintomas de depressão e ansiedade nos pacientes com DP na pandemia de Covid-19, quando comparados com aqueles que não possuem a doença. Foram incluídos neste estudo 60 sujeitos, 30 com DP e 30 idosos sem desordens neurológicas. Foi avaliado o perfil sociodemografico e aplicada a Escala de Ansiedade e Depressão (HAD). Os resultados obtidos mostraram que não há diferença estatisticamente significativa, no tocante ao estado psicossocial, entre os grupos analisados, o que sustenta a conclusão de alguns estudos, mas também diverge dos resultados de outros, sendo necessárias novas análises com amostras maiores e ferramentas mais abrangentes

Evaluation of the effects of chronic stress under anxiety-like behavior and nociceptive sensitivity in rats reared in enriched environment

Respostas adaptativas ao estresse podem ser acompanhadas por alterações nos comportamentos emocionais, em particular relacionados com medo e ansiedade, bem como alterações na sensibilidade dolorosa. Ainda, tem sido investigado o papel do óxido nítrico em áreas encefálicas relacionadas ao comportamento defensivo. Embora várias evidências têm demonstrado que o enriquecimento ambiental promove melhora nos processos de memória, no aprendizado e em respostas nociceptivas, a relação entre o estresse crônico e as vantagens da utilização do enriquecimento ambiental ainda são pouco investigadas. O presente estudo teve como objetivo investigar se o enriquecimento ambiental promove alteração do comportamento emocional, da sensibilidade nociceptiva, bem como na imunorreatividade à nNOS no núcleo central da amígdala, na formação hipocampal e na região dorsolateral da substância cinzenta periaquedutal, em ratos submetidos ao estresse por isolamento social ou estresse crônico variado e mantidos em ambiente enriquecido ou sem enriquecimento. Ratos machos Wistar (~70g) foram divididos aleatoriamente em dois grandes grupos experimentais: Ambiente Padrão (Padrão) ou Ambiente Enriquecido (EE), mantidos por 38 dias. Cada grupo foi subdividido dependendo do tipo de estresse crônico: Controle (sem estresse), Isolamento Social (por 38 dias) e Estresse Crônico Variado (do dia 28 ao dia 37). Ao fim do tempo experimental (dia 38) os ratos foram avaliados quanto ao comportamento emocional pelos testes de labirinto em cruz elevado (LCE) e claro/escuro (TCE) e sensibilidade nociceptiva pelo teste da placa quente (a qual foi realizada em duas etapas, sendo a primeira medida no dia 0 e outra no dia 38). A eutanásia dos ratos ocorreu no dia 39, para coleta do encéfalo para análise da imunorreatividade à óxido nítrico sintase neuronal (nNOS). Levando-se em consideração o comportamento emocional e a sensibilidade nociceptiva, os diferentes tipos de estresse crônico diminuíram a porcentagem de tempo, a frequência de entrada e a exploração da extremidade dos braços abertos e na frequência de mergulho de cabeça no teste do LCE, apesar de não alterar a sensibilidade nociceptiva. Por outro lado, o enriquecimento ambiental aumentou a porcentagem de tempo, a frequência de entrada e a exploração da extremidade dos braços abertos no teste do LCE, apesar de não alterar a sensibilidade nociceptiva. Foi observado aumento da imunorreatividade à nNOS na formação hipocampal em diferentes tipos de estresse crônico. Em particular, na região de CA3 houve interação significante entre os fatores estresse por isolamento social e ambiente de manutenção. Deste modo, os resultados obtidos neste trabalho sugerem que a formação hipocampal desempenha importante função no efeito ansiogênico exercido pelos diferentes tipos de estressores crônicos (aqui representados pelo isolamento social e pelo estresse crônico variado) provavelmente pela ativação do sistema nitrérgico e sugere-se que o enriquecimento possa prevenir o comportamento do tipo ansioso.Adaptive responses to stress may be accompanied by changes in emotional behaviors, in particular related to fear and anxiety, as well as changes in pain sensitivity. Furthermore, the role of nitric oxide in brain areas related to defensive behavior has been investigated. Although several evidences have shown that environmental enrichment improves memory processes, learning and nociceptive responses, the relationship between chronic stress and the advantages of using environmental enrichment is still poorly investigated. The present study aimed to investigate whether environmental enrichment promotes alteration of the emotional behavior, nociceptive sensitivity, as well as immunoreactivity to neuronal nitric oxide synthase (nNOS) in the central nucleus of the amygdala, hippocampal formation and dorsolateral periaqueductal gray matter in rats submitted to social isolation stress or chronic unpredictable stress and reared in enriched environment or standard environment. Male Wistar rats (~ 70g) were randomly divided into two major experimental groups: Standard Environment (Standard) or Enriched Environment (EE), maintained for 38 days. Each group was subdivided according to the type of chronic stress: Control (without stress), Social Isolation (for 38 days) and Chronic Unpredictable Stress (from day 28 to day 37). At the end of the experimental time (day 38), the rats were evaluated for emotional behavior by elevated plus maze (EPM) and light/dark box (LDBT) tests and nociceptive sensitivity by the hot plate test (which was performed in two steps , the first being measured on day 0 and the other on day 38). Euthanasia of rats occurred on day 39, to collect the brain for nNOS immunoreactivity analysis. Taking into account emotional behavior and nociceptive sensitivity, the different types of chronic stress decreased the percentage of time, the frequency of entry of the open arms, end-arm exploration and the head dipping frequency in the EPM, despite of not altering the nociceptive sensitivity. On the other hand, environmental enrichment increased the percentage of time, the frequency of entry of the open arms and the end arm-exploration in the EPM test, although it did not alter the nociceptive sensitivity. Increased immunoreactivity to nNOS in hippocampal formation was observed in different types of chronic stress. In particular, in the CA3 region there was a significant interaction between stress factors due to social isolation and maintenance environment. Thus, the results obtained in this study suggest that hippocampal formation plays an important role in the anxiogenic effect exerted by the different types of chronic stressors (represented here by social isolation and by chronic chronic stress) probably due to the activation of the nitrergic system and it is suggested that environmental enrichment can prevent of anxiety-like behavior

Morphophysiological evaluation of lateral pterigoid muscle and orofacial nociceptive sensibility in rats with masticatory hipofunction

Evidências clínicas sugerem que o estresse emocional pode ser um fator de risco para as desordens temporomandibulares (DTM), bem como para outras funções desempenhadas pelo sistema estomatognático. Ainda é controversa a participação da alteração oclusal na etiopatogenia das dores miofasciais. O músculo pterigoideo lateral foi escolhido pela íntima relação com a articulação temporomandibular (ATM). Assim, o objetivo deste projeto foi avaliar a hipótese de que os diferentes tipos de estresse agudo e crônico (repetido e variado) induzem alterações morfofisiológicas no músculo pterigóideo lateral esquerdo em animais submetidos ou não à exodontia unilateral. Em uma segunda etapa, foi avaliada se o procedimento de exodontia unilateral promove alteração da sensibilidade nociceptiva orofacial. Foram utilizados 60 ratos machos Wistar (250 g), divididos aleatoriamente em 2 grandes protocolos: Exodontia (GE): expostos a exodontia unilateral (n = 30); e Sem Exodontia (GSE): sem exodontia unilateral (n = 30). Cada protocolo foi composto por 6 subgrupos (n = 5 ratos cada): Ag: Estresse agudo; Rep: Estresse crônico repetido; Var: Estresse crônico variado; Form: Avaliação nociceptiva orofacial; Sal: Avaliação nociceptiva orofacial (controle formalina); e C: sem estresse (Controle estresses). O GE foi submetido à exodontia unilateral dos molares superiores esquerdo, sob anestesia com associação de xilazina 4% (10mg/kg) e cetamina 10% (80mg/kg), i.p. Em ambos os grupos: GE e GSE, os ratos dos subgrupos Rep e Var foram submetidos aos protocolos de estresse (por 10 dias) a partir do 14º dia após a exodontia; e no 23º, os animais do subgrupo Ag, foram submetidos ao estresse agudo, e dos subgrupos Form e Sal foram submetidos ao protocolo de Formalina orofacial. Com o término dos experimentos, os animais foram submetidos à eutanásia para obtenção dos músculos para análise. Os estresses crônicos, isolados ou associados à exodontia, afetaram a morfologia, a capacidade oxidativa, o estresse oxidativo e a densidade capilar do músculo pterigoideo lateral esquerdo. Estes sinais demonstram a adaptação deste músculo, no período estudado, e sugerem que a persistência destes estímulos podem levar à respostas mais severas como, por exemplo, desencadear a dor miofacial ligada à DTM.Clinical evidences have suggested that emotional stress could be a risk factor for temporomandibular joint disorder (TMD), as well as other functions performed by stomatognatic system. Remains controversial the participation of occlusal alteration on the miofascial pain etiopathogenesis. The lateral pterygoid muscle was chosen because of the closely relationship with temporomandibular joint (TMJ). Therefore, the aim of this project was evaluate the hypothesis that different types of acute and chronic (repeted and unpredictable) stress induce morphophysiological alteration on the left lateral pterygoid muscle in animals submitted or not to unilateral exodontia. In a second phase, it was evaluated whether the unilateral exodontia procedure promotes orofacial nociceptive sensibility alteration. Sixty male Wistar rats (250 g) were randomly divided into 2 protocols: Exodontia (GE): exposed to unilateral exodontia (n = 30); and Without Exodontia (GSE): without unilateral exodontia (n = 30). Each protocol was composed by 6 subgroups (n = 5): Ag: Acute Stress; Rep: Repeted Chronic Stress; Var: Unpredictable Chronic Stress; Form: Orofacial Nociception Evaluation; Sal: Orofacial Nociception Evaluation (Formalin Control); and C: No Stress (Stress Control). The GE was submitted to unilateral exodontia of superior left molar under anesthesia with the association of xylazine 4% (10 mg/kg) and ketamine 10% (80 mg/kg), i.p. In both groups: GE and GSE, the rats in subgroups Rep and Var were submitted to the stress protocols (during 10 days) from the 14th day after exodontia, and on day 23rd , the animais from subgroup Ag, were submitted to acute stress, and the subgroups Form and Sal were submitted to the Orofacial Formalin protocol. With the end of the experiments, the animals were submitted to euthanasia to obtaining muscle for analysis. The chronic stress, isolated or associated to exodontia, affected the morphology, oxidative capacity, oxidative stress and capillary density of left lateral pterygoid muscle. These signs show the adaptation of this muscle, during the studied period, suggesting that the persistence of these stimuli can lead to a more severe response, such as, myofascial pain trigger linked to the DTM

Muscle characterization of reactive oxygen species in oral diseases

Importance and objective. Reactive Oxygen Species (ROS) are oxygen-derived molecules that are unstable and highly reactive. They are important signaling mediators of biological processes. In contrast, excessive ROS generation, defective oxidant scavenging or both have been implicated in the pathogenesis of several conditions. This biological paradox of ROS function contributes to the integrity of cells and tissues. So, the aim of this review was examined for published literature related to 'reactive oxygen species and dentistry and muscle'. Materials and methods. A PubMed search was performed by using the following key words: 'reactive oxygen species and dentistry and muscle'. Results. Involvement of ROS in pathologic conditions can be highlighted in oral diseases like periodontitis, orofacial pain, temporomandibular disorders and oral cancer. Also, several studies have correlated the increase in ROS production with the initiation of the muscle fatigue process and the process of muscle injury. However, studies evaluating the relation of ROS and orofacial muscles, which can prove very important to understand the fatigue muscle in this region during oral movements, have not yet been conducted. Conclusions. It is concluded that the data on skeletal muscles, especially those of mastication, are not commonly published in this data source; therefore, further studies in this field are strongly recommended7328186sem informaçã

Melhoria de eficiência de uma linha de montagem de aerossóis

Atualmente, os clientes são cada vez mais exigentes em termos de qualidade e tempo de entrega dos seus produtos. A complexidade do mercado e a concorrência entre empresas obriga as organizações a definir estratégias diferenciadoras. Neste sentido, o modelo de melhoria continua da Colep tem como principal objetivo criar uma cultura na empresa que permita responder a estes desafios. É, portanto, necessário um ambiente de constante adaptação e uma mentalidade de melhoria continua, onde o foco é a excelência operacional. Para tal é necessário produzir “bem à primeira”, reduzir o desperdício e com máxima segurança. O presente projeto procurou a melhoria de eficiência de uma linha de montagem de aerossóis, através da aplicação de ferramentas e técnicas Lean. Uma das principais ferramentas Lean utilizadas neste projeto foi o SMED (Single Minute Exchange of Die), e consequentemente, os 5S, standard work e ciclo PDCA. Esta metodologia tem como grande foco a eliminação/redução dos desperdícios e a melhora da eficiência dos processos. A chave para o sucesso destas ferramentas são as pessoas, motivo pelo qual se torna fundamental o envolvimento de todos, de forma a possibilitar a mudança dos hábitos e consequentemente, a cultura das equipas. Foi também criado um Poka-Yoke, sistema anti erro, que eliminou os encravamentos constantes que surgiam na linha de produção. Para monitorizar todo este projeto foi criado um A3, onde o grande foco de análise foi sempre o indicador de OEE e o tempo de setup. Os objetivos foram cumpridos e os resultados comprovam ainda, que, as ferramentas Lean são uma metodologia a seguir. Foram obtidos elevados ganhos de produtividade sem investimentos muito avultados.Nowadays, the clients are more rigorous about quality and lead time of the products. The market complexity and the competition between companies forces the organizations to think outside the box. Thus, Colep has a major goal to create a corporate culture that allows to respond to those challenges. So, it’s necessary to create an adaptive environment and continuous improvement mentality where the focus is the operative excellence. For such purpose is necessary to produce “well at first”, reduce the waste and with maximum safety. The present project seeks for the improvement of the efficiency of an aerosol assembly line, through the application of Lean tools and techniques. One of the main Lean tools used in this project was the SMED (Single Minute Exchange of Die), therefore, the 5S, standard work and PDCA cycle. This methodology has a great focus in elimination/reduction waste and improving the process efficiency. The key to success of these tools are the people, the participation of everyone is the most important to make possible the change of the habits and consequently, the culture of the team. It was also created a Poka-Yoke, an anti-mistake system, that eliminated constant breakdowns in the production line. To follow up the project was created an A3, where the major focus of analysis was always the OEE and Setup time, The goals were accomplished, and the results shows, the Lean tools are a methodology to follow. There was a productivity increment with low investment

Ultrastructure and Light Microscope Analysis of Intact Skin after a Varying Number of Low Level Laser Irradiations in Mice

Low level laser therapy (LLLT) has been used to relieve pain, inflammation, and wound healing processes. Thus, the skin is overexposed to laser and this effect is not completely understood. This study analyzed the effects of the number of laser applications (three, six, and 10) on the intact skin of the masseteric region in mice of strain HRS/J. The animals (n=30) were equally divided into control (0 J/cm2) and irradiated (20 J/cm2), and each of these groups was further equally divided according to the number of laser applications (three, six, and 10) and underwent LLLT on alternate days. Samples were analyzed by light microscopy and transmission electron microscope (TEM). The animals receiving applications exhibited open channels more dilated between the keratinocytes and photobiomodulation effect on endothelial cells and fibroblasts by TEM. Under the light microscope after 10 laser applications, the type I collagen decreased (P<0.05) compared to the three and six applications. Under these experimental conditions, all numbers of applications provided photobiomodulatory effect on the epidermis and dermis, without damage. More studies are needed to standardize the energy density and number of applications recommended for laser therapy to have a better cost-benefit ratio associated with treatment

Exodontia‐induced muscular hypofunction by itself or associated to chronic stress impairs masseter muscle morphology and its mitochondrial function

Stress is associated with orofacial pain sensitivity and is qualified as a temporomandibular disorder risk factor. During stressful periods, painful thresholds of masticatory muscles in individuals suffering muscle facial pain are significantly lower than in controls, but the exact physiologic mechanism underlying this relation remains unclear. Our hypothesis is that chronic unpredictable stress and masticatory hypofunction induce morphologic and metabolic masseter muscle changes in rats. For test this hypothesis, adult Wistar rats were submitted to chronic unpredictable stress and/or exodontia of left molars and the left masseter muscle was removed for analysis. The parameters evaluated included ultrastructure, oxidative level, metabolism activity and morphological analysis in this muscle. Our data show by histological analysis, that stress and exodontia promoted a variation on diameters and also angled contours in masseter fibers. The masticatory hypofunction increased oxidative metabolism as well as decreased reactive species of oxygen in masseter muscle. The ultrastructural analysis of muscle fibers showed disruption of the sarcoplasmic reticulum cisterns in certain regions of the fiber in stress group, and the disappearance of the sarcoplasmic reticulum membrane in group with association of stress and exodontia. Our findings clarify mechanisms by which chronic stress and masticatory hypofunction might be involved in the pathophysiology of muscular dysfunctions. Masticatory hypofunction influenced oxidative stress and induced oxidative metabolism on masseter muscle, as well as altered its fiber morphology. Chronic stress presented malefic effect on masseter morphology at micro and ultra structurally. When both stimuli were applied, there were atrophic fibers and a complete mitochondrial derangement825530537FAPESP – Fundação de Amparo à Pesquisa Do Estado De São Paulo2015/03053-3; 2012/22128-6Art, science, microscopy and ED

Metabolic Changes in Masseter Muscle of Rats Submitted to Acute Stress Associated with Exodontia.

Clinical evidence has shown that stress may be associated with alterations in masticatory muscle functions. Morphological changes in masticatory muscles induced by occlusal alterations and associated with emotional stress are still lacking in the literature. The objective of this study was to evaluate the influence of acute stress on metabolic activity and oxidative stress of masseter muscles of rats subjected to occlusal modification through morphological and histochemical analyses. In this study, adult Wistar rats were divided into 4 groups: a group with extraction and acute stress (E+A); group with extraction and without stress (E+C); group without extraction and with acute stress (NO+A); and control group without both extraction and stress (NO+C). Masseter muscles were analyzed by Succinate Dehydrogenase (SDH), Nicotinamide Adenine Dinucleotide Diaphorase (NADH) and Reactive Oxygen Species (ROS) techniques. Statistical analyses and two-way ANOVA were applied, followed by Tukey-Kramer tests. In the SDH test, the E+C, E+A and NO+A groups showed a decrease in high desidrogenase activities fibers (P < 0.05), compared to the NO+C group. In the NADH test, there was no difference among the different groups. In the ROS test, in contrast, E+A, E+C and NO+A groups showed a decrease in ROS expression, compared to NO+C groups (P < 0.05). Modified dental occlusion and acute stress--which are important and prevalent problems that affect the general population--are important etiologic factors in metabolic plasticity and ROS levels of masseter muscles