Photobiomodulation therapy increases collagen II after tendon experimental injury.

A tendon is a mechanosensitive tissue that transmits muscle-derived forces to bones. Photobiomodulation (PBM), also known as low-level laser therapy (LLLT), has been used in therapeutic approaches in tendon lesions, but uncertainties regarding its mechanisms of action have prevented its widespread use. We investigated the response of PBM therapy in experimental lesions of the Achilles tendon in rats. Thirty adult male Wistar rats weighing 250 to 300 g were surgically submitted to bilateral partial transverse section of the Achilles tendon. The right tendon was treated with PBM, whereas the left tendon served as a control. On the third postoperative day, the rats were divided into three experimental groups consisting of ten rats each, which were treated with PBM (Konf, Aculas - HB 750), 780 nm and 80 mW for 20 seconds, three times/week for 7, 14 and 28 days. The rats were sacrificed at the end of the therapeutic time period. The Sca-1 was examined by immunohistochemistry and histomorphometry, and COLA1, COLA2 and COLA3 gene expression was examined by qRT-PCR. COLA2 gene expression was higher in PBM treated tendons than in the control group. The histomorphometric analysis coincided with increased number of mesenchymal cells, characterized by Sca-1 expression in the lesion region (p<0.001). PBM effectively interferes in tendon tissue repair after injury by stimulating mesenchymal cell proliferation and the synthesis of collagen type II, which is suggested to provide structural support to the interstitial tissues during the healing process of the Achilles tendon. Further studies are needed to confirm the role of PBM in tendon healing.

Anatomical Study of the Innervation of the Masseter Muscle and Its Correlation with Myofascial Trigger Points.

BACKGROUND AND PURPOSE: Myofascial pain syndrome (MPS) is widely prevalent in the general population; some reports estimate its prevalence ranges from 9 to 85%. Among the different locations where MPS may arise, pain related to the masseter muscle is referred as masticatory myofascial pain. MPS is characterized by myofascial trigger points (MTPs), which represent tender anatomical areas of a muscle where painful symptoms are elicited whenever stimulated. Previous publications have found MTPs to coincide with neuromuscular junctions at the motor end plate, at the innervation zone (IZ). Our study aimed to describe the innervation of the masseter muscle and relate it to clinically described myofascial trigger points (MTPs). MATERIALS AND METHODS: We mapped the nerve fiber distribution into the masseter muscles from 16 cadavers by anatomical dissection. We divided the muscle into six regions, three superior (I-III) and three inferior (IV-VI), and classified the nerve's branches distribution according to these predetermined areas. Statistical analyses was made by Poisson distribution and logarithm link function followed by Bonferroni multiple comparisons (P<0.05). RESULTS: All six areas received branches from the masseteric nerve. Areas I and II (upper posterior and upper intermediate, respectively) had a significant higher number of nerve entries as compared to the remaining areas. CONCLUSION: The penetration areas of the masseteric nerve have been established and MTPs are found in the innervation zones, clinicians should focus initially on the regions of the penetration points, for diagnostics and therapeutic measures, such as injections, dry needling and soft tissue interventions. Anatomical study of nerve supply to the masseter muscle can provide useful additional knowledge to further understanding masticatory myofascial pain and to direct therapeutic interventions and diagnostic studies of temporomandibular junction dysfunction.

Aderência intertalâmica e Alzheimer: estudo preliminar / Interthalamic adhesion and Alzheimer's: preliminary study

Objetivo: Descrever dimensões e prevalência da Aderência Intertalâmica (AI) em cadáveres do Serviço de Verificação de Óbitos da Capital - USP, considerando idade, sexo, peso, altura e histórico pessoal de doença de Alzheimer (DA). Métodos: Cinquenta e sete cadáveres (31H/26M) foram incluídos no estudo, com média de idade de 66,2 anos (variando entre 15 e 91 anos). A análise da AI foi feita após secção transversal da calota craniana e incisão axial no limite inferior do tronco encefálico seguida de retirada do encéfalo de sua cavidade. Cinquenta e quatro encéfalos foram submetidos a incisão sagital mediana, dois encéfalos foram submetidos a cortes axiais, e um encéfalo a secção coronal. Dados quantitativos foram comparadas pelo teste t de student, e dados qualitativos pelo teste de Qui Quadrado. A análise idade vs área foi feita por regressão linear. Resultados: A prevalência de AI foi de 79%, não havendo diferença significativa entre os sexos (p=0,68).  Observou-se associação entre menores áreas de secção sagital e idades mais avançadas (p=0,02). Não houve diferença significativa na prevalência de AI nem na área de secção transversal em pacientes com DA. Discussão: Ao contrário de estudos prévios, que associaram maior prevalência e tamanho de AI com sexo feminino, isso não foi observado em nossa casuística. Apesar de não ser estatisticamente significativa nota-se uma diferença importante nas áreas médias de secção sagital dos grupos com e sem DA, o que aponta para a necessidade de estudos subsequentes com amostras maiores

Objective: Identifying the prevalence and dimensions of the Interthalamic Adhesion (ITA) in corpses from the "Serviço de Verificação de Óbitos da Capital - USP", considering factors as age, sex, weight, height, and diagnosis of Alzheimer's disease (AD). Methods: Fifty-seven corpses (31M/26F) were included in the study. The mean age was 66.2 (varying between 15 and 91). The analysis of the ITA was made after the encephalon's removal from its cavity, which occurred by the transversal section of the skullcap, and, next, an axial incision in the inferior limit of the pons to separate the encephalon from the spinal cord. Fifty-four encephalons were submitted to medial sagittal incisions, two encephalons were submitted to axial cuts and one to a coronal section. Quantitative data were compared by the Student's T Test, and qualitative data by the Chi-squared test. The Age vs Area analysis was made by linear regression. Results: the prevalence of the ITA was 79%, not having differences in prevalence between sexes (p=0.68). Advanced ages presented lower areas in sagittal sections (p= 0.02). It does not appear to have a significant alteration in prevalence of the ITA and transversal section aerea in patients with AD. Discussion: Unlike previous studies which observed higher prevalence and size of the ITA in females, differences in this parameters were not obtained in this study. Evidence of correlation between AD and lower sagittal section of the ITA, even without statistic significance, points to the need of further studies.

Lymph drainage of the upper limb and mammary region to the axilla: anatomical study in stillborns.

PURPOSE: We studied the lymphatic drainage of the upper limb and mammary region directing to the axilla to investigate whether independent pathways can be observed or whether anastomoses and shared drainage occur between them. This analysis aimed to assess the safety of axillary reverse mapping (ARM) in breast cancer treatment and to understand the development of lymphedema after sentinel lymph node biopsy (SLNB) alone. METHODS: Seven unfixed stillborn fetuses were injected with a modified Gerota mass in the peri-areolar area, palm and dorsum of the hands, formalin fixed, and then submerged in 10% hydrogen peroxide solution. Microsurgical dissection was then performed on the subcutaneous cellular tissue of the upper limb, axillary region, and anterior thorax to expose the lymphatic vessels and lymph nodes. RESULTS: The dye injected into the upper limb reached either the lateral axillary group, known to be exclusively responsible for upper limb drainage, or the anterior group, which is typically related to breast drainage. There was great proximity among the pathways and lymph nodes. Communicating lymphatic vessels among these groups of lymph nodes were also found in all studied cases. DISCUSSION: Lymphedema remains a challenging morbidity in breast cancer treatment. ARM and SLNB aim to avoid unnecessary damage to the lymphatic drainage of the upper limb. However, our anatomical study suggests that ARM may have potential oncological risks because preserved lymph nodes may harbor malignant cells due their proximity, overlapping drainage pathways, and connecting lymph vessels among lymph nodes.

Radiofrequency preserves histoarchitecture and enhances collagen synthesis in experimental tendon injury.

We investigated the action of radiofrequency (RF) on the healing process after inducing experimental lesions of the Achilles tendon in rats. Wistar rats were surgically subjected to bilateral partial transverse sectioning of the Achilles tendon. The right tendon was treated with radiofrequency (RFT), whereas the left tendon served as a control (CT). On the third postoperative day, the rats were divided into three experimental groups consisting of ten rats each, which were treated with monopolar radiofrequency (Tonederm™) until they were sacrificed on the 7th, 14th or 28th days. The histological specimens were studied for inflammatory cell content, collagen types I and III, immunostaining and morphometry. Total collagen were biochemically analyzed and to evalute fibroblast and myofibroblast proliferation by vimentin and α-actin smooth muscle immunohistochemistry methods. Statistical analysis was performed using the Student's t-test, the sign test and the Kruskal-Wallis test to compare tendons treated with radiofrequency with the non-treated tendons (α=5%; α=10%). Larger amounts of collagen I with hydroxyproline content and myofibroblast cells were clearly evident within 7 days (p<0.05). No difference was observed in the inflammatory cell content between the groups. We found better collagen arrangement with RF administration across the entire time studied. Radiofrequency administration preserves histoarchitecture and enhances collagen synthesis during the initial phases of cicatrization, suggesting that the treatment can provide improved stiffness during the most vulnerable phases of tendon healing. Clinical studies may include RF among the therapeutic tools in tendinous lesion management.