Crotoxin inhibits endothelial cell functions in two- and three-dimensional tumor microenvironment

Antitumor property of Crotoxin (CTX), the major toxin from Crotalus durissus terrificus snake venom, has been demonstrated in experimental animal models and clinical trials. However, the direct action of this toxin on the significant events involved in neovascularization, which are essential for tumor growth and survival, has not been confirmed. This study investigated the effects of CTX on the key parameters of neovascularization in two- and three-dimensional culture models. Murine endothelial cell lines derived from thymus hemangioma (t.End.1) were treated at different concentrations of CTX (6.25–200 nM). Endothelial cell proliferation, cell adhesion, and actin cytoskeletal dynamics on laminin (10 µg/ml), type I collagen (10 µg/ml), and fibronectin (3 µg/ml) were evaluated along with the endothelial cell migration and formation of capillary-like tubes in 3D Matrigel. CTX concentration of 50 nM inhibited tube formation on 3D Matrigel and impaired cell adhesion, proliferation, and migration under both culture medium and tumor-conditioned medium. These actions were not accountable for the loss of cell viability. Inhibition of cell adhesion to different extracellular matrix components was related to the reduction of αv and α2 integrin distribution and cytoskeletal actin polymerization (F-actin), accompanied by inhibition of focal adhesion kinase (FAK), Rac1 (GTPase) signaling proteins, and actin-related protein 2/3 (Arp 2/3) complex. This study proved that CTX inhibits the major events involved in angiogenesis, particularly against tumor stimuli, highlighting the importance of the anti-angiogenic action of CTX in inhibition of tumor progression.

Topical cream containing nanoparticles with vitamin E to prevent radiodermatitis in women with breast cancer: a clinical trial protocol.

OBJECTIVE: Little is known about the efficacy of products aiming to prevent radiodermatitis, which affects between 90-95% of women with breast cancer. The use of antioxidants is promising, however, there is a lack of evidenceon their effectiveness. Here, the authors present a clinical trial protocol to evaluate the effects of applying a cream containing nanoparticles with vitamin E to prevent radiodermatitis in patients with breast cancer. METHOD: The protocol recommends that 108 women with breast cancer, receiving radiotherapy, are included in this triple-blinded, randomized, controlled study at an oncology hospital. Patients will be divided in three groups of 36 individuals each: group A will receive a cream with lipid nanoparticles and vitamin E, group B will receive a cream without nanoparticles nor vitamin E, and group C will receive a cream with nanoparticles without vitamin E. The primary endpoints will evaluate the incidence, degree, and time of onset of radiodermatitis. The secondary endpoints will focus on the quality of life, symptoms, and local temperature. Patients will be assessed three times a week, from the start of their radiotherapy treatment to two weeks after the last session. This protocol was approved by the research ethics committee of the institutions involved and registered on an international trials database.

Clinical protocol for the topical use of a cream with nanoparticles and vitamin E to prevent radiodermatitis in patients with breast cancer]. / Aplicación tópica de crema con nanopartículas con vitamina E para prevenir radiodermatitis en cáncer de mama: protocolo de ensayo clínico.

Objetivo: Poco se conoce sobre la eficacia de productos para la prevención de radiodermatitis, que afecta al 90­95% de las mujeres con cáncer de mama. El uso de antioxidantes es promisorio, sin embargo, poco estudiado. Los autores desarrollaron un protocolo de ensayo clínico para evaluar el efecto potencial de la aplicación de crema con nanopartículas con vitamina E para prevenir radiodermatitis aguda en mujeres con cáncer de mama. Método: El protocolo sugiere que 108 mujeres adultas con cáncer de mama, que estén recibiendo radioterapia, sean incluidas en este ensayo clínico, controlado, aleatorizado y triple ciego, en un hospital oncológico. Se prevé la distribución de pacientes en tres grupos de 36 personas: el grupo A recibirá una crema con nanopartículas lipídicas con vitamina E, el grupo B obtendrá una crema sin nanopartículas ni vitamina E, y el grupo C usará una crema con nanopartículas sin vitamina E. Los resultados primarios evaluarán la incidencia, el grado y el tiempo de surgimiento de la radiodermatitis. Los resultados secundarios se centrarán en la calidad de vida, los síntomas y la temperatura local. Las pacientes serán evaluadas tres veces por semana, desde el inicio de la radioterapia hasta dos semanas después de la última sesión. El presente proyecto fue aprobado por el comité de ética en investigación de las instituciones involucradas.Objective: Little is known about the efficacy of products that aim to prevent radiodermatitis, which affects between 90­95% of women with breast cancer. The use of antioxidants is promising, however, there is a lack of evidence on their effectiveness. Here, the authors present a clinical trial protocol to evaluate the potential effects of applying a nanoparticle cream with vitamin E to prevent radiodermatitis in patients with breast cancer. Method: The protocol recommends that 108 women with breast cancer, who are receiving radiotherapy, be included in a triple-blinded, randomised, controlled study in an oncology hospital. Patients will be divided in three groups of 36 people each: group A will receive a cream with lipid nanoparticles and vitamin E, group B will obtain a cream without nanoparticles or vitamin E, and group C will receive a cream with nanoparticles without vitamin E. The primary endpoints will evaluate the incidence, degree and time of onset of radiodermatitis. The secondary endpoints will focus on quality of life, symptoms and local temperature. Patients will be assessed three times a week, from the start of their radiotherapy treatment to two weeks after the last session. This protocol was approved by the research ethics committee of the institutions involved.

Late hyaluronidase injection in local anesthesia: Morphofunctional evaluation in rat sciatic nerve block.

INTRODUCTION: Despite the enhancing effects of hyaluronidase (HYAL) over duration of anesthesia, this enzyme could cause adverse effects when injected concomitantly with local anesthetics in dental blocks. OBJECTIVE: This study aimed to assess the tissue alterations caused by a local anesthetic protocol consisting of a late HYAL injection and confirm its functional effectiveness. MATERIALS AND METHODS: The protocol efficacy was proved by evaluating sensory and motor functions in rats. The sciatic nerve was blocked with 2% lidocaine (LID) with epinephrine (n = 25). Thirty minutes later, 75 TRU/ml HYAL was injected into the same site (experimental group, LID/HYAL). One week later, this protocol was repeated in the contralateral hindlimb, injecting only HYAL's vehicle (control group, LID/vehicle [LID/V]). To observe the integrity of the local tissues, histological specimens were obtained 1, 24, 48, and 72 h after treatment with LID/HYAL or LID/V (n = 16 each) and stained with hematoxylin/eosin and picrosirius red. RESULTS: Local inflammation was similar in both groups. The integrity of the nerve fibers was preserved, in spite of some inflammation-associated injuries in the surrounding tissues. The reversible tissue disorganization caused by HYAL, probably facilitated the diffusion of the residual anesthetic to the nerve, resulting in a prolonged anesthetic effect (P < 0.05). CONCLUSIONS: No irreversible morphological alterations are caused by the administration of HYAL prior the end of the LID-induced block. Moreover, this protocol prolongs LID's anesthetic effect.

Long- and short-term diabetes mellitus type 1 modify young and elder rat salivary glands morphology.

OBJECTIVE: In this study we performed a temporal analysis of the effects of Diabetes Mellitus on morphology and laminin deposition in salivary glands of young (2 months-old) and aging (12 months-old) male Wistar rats, using immunohistochemistry. MATERIALS AND METHODS: The animals were divided in control and diabetic (Streptozotocin induced) groups and euthanized after short and long-term diabetes induction. RESULTS: Short-term induction led to vacuolization of parotid acinar cells and increased laminin deposition in both animal ages. In young rats, no difference was observed between short or long-term diabetes regarding laminin deposition, but parotid acinar cells vacuolization was more discrete after long-term diabetes. A slight decrease of submandibular gland convoluted granular ducts was observed in young and elder diabetic animal ages. In diabetic aging rats was observed an increase of laminin content only in the parotid gland. CONCLUSIONS: These results suggest that some Diabetes Mellitus effects on salivary glands are not progressive over time, possibly due to the existence of adaptive mechanisms in response to chronic hyperglycemia. They also show that the duration of the disease was more relevant to the morphological effects than the age, although it is known that aging per se affects salivary gland morphology and function.

Rho signaling pathway and apical constriction in the early lens placode.

Epithelial invagination in many model systems is driven by apical cell constriction, mediated by actin and myosin II contraction regulated by GTPase activity. Here we investigate apical constriction during chick lens placode invagination. Inhibition of actin polymerization and myosin II activity by cytochalasin D or blebbistatin prevents lens invagination. To further verify if lens placode invaginate through apical constriction, we analyzed the role of Rho-ROCK pathway. Rho GTPases expression at the apical portion of the lens placode occurs with the same dynamics as that of the cytoskeleton. Overexpression of the pan-Rho inhibitor C3 exotoxin abolished invagination and had a strong effect on apical myosin II enrichment and a mild effect on apical actin localization. In contrast, pharmacological inhibition of ROCK activity interfered significantly with apical enrichment of both actin and myosin. These results suggest that apical constriction in lens invagination involves ROCK but apical concentration of actin and myosin are regulated through different pathways upstream of ROCK. genesis 49:368-379, 2011.

Immobilized kidney 28-kda endostatin-related (KES28kDa) fragment promotes endothelial cell survival

Background/Objective: Renal ischemia-hypoxia is a leading cause of acute kidney injury (AKI). Ischemia causes extracellular matrix breakdown of the tubular basement membrane. Endostatin (ES) is the C-terminal fragment of collagen XVIII generated by proteolytic cleavage. Recent studies have demonstrated that ES expression is upregulated in ischemic kidneys. The present study aimed to characterize ES from ischemic kidneys. Methods: Ischemic renal failure was induced via 45 min of occlusion of the left renal artery and vein. After the ischemic period, blood was collected. Kidneys were harvested and used for immunohistochemical testing and protein extraction. Three-step purification was used. Soluble and immobilized purified ES were tested in cell viability and adhesion assays. Results: The soluble KES28kDa inhibited endothelial cell proliferation: 25 versus 12.5 ìg (p < 0.05); 12.5 versus 3.15 ìg (p < 0.05). Immobilization of KES28kDa supports endothelial cell survival over the control (p = 0.021). Human umbilical vein endothelial cells plated on immobilized KES28kDa showed an increase in membrane ruffles and stress fibers. Conclusion: These data demonstrate the local synthesis of a 28-kDa ES-related fragment following AKI and suggest its role in endothelium survival.

Radioisotopic evaluation of bone repair after experimental surgical trauma

Este trabalho objetivou estudar a evolução temporal do processo de reparo ósseo em tíbia de rato, após trauma cirúrgico padronizado. A incorporação do radiofármaco 99mTc-MDP na região afetada foi tomada como medida indireta da intensidade de reação tecidual; foi feito também acompanhamento histológico do processo de reparo. Foram realizadas cirurgias nas duas tíbias de 72 animais divididos em 2 grupos, sendo sacrificados em diferentes dias pós-operatórios (1, 3, 7, 14, 21 e 28 dias p.o.). As cavidades criadas nas tíbias esquerdas foram preenchidas com osso liofilizado bovino, e as direitas serviram como controle (não preenchidas). Grupos paralelos de animais foram injetados com 99mTc para avaliar a influência do fluxo sangüíneo regional nos resultados. Duas horas após a injeção dos radiofármacos os animais foram sacrificados, a radiatividade foi contada tanto nos fragmentos das tíbias contendo os defeitos cirúrgicos como em fragmentos intactos de fêmur e de tíbias, como controle. Os resultados indicam que a maior atividade do tecido ósseo ocorreu entre 7 e 14 dias p.o. O emprego do radiofármaco mostrou ser de valor na avaliação do reparo dada sua sensibilidade. Não houve efeito significativo da presença de osso liofilizado sobre a evolução do reparo ósseo.

Radioisotopic evaluation of bone repair after experimental surgical trauma.

BACKGROUND: Scientific approach of the bone reaction after surgical procedures provides valuable information on methods and techniques. The purpose of this study was to follow this process using a radioisotope marker of bone remodelling. MATERIAL AND METHODS: Two bone cavities were created (one for every tibia) in adult Wistar male rats using a 0.5 mm spherical burr; left tibial cavities were filled with bovine freeze-dried bone; the right ones were left unfilled for control. Scintigrams were done with sodium methylene diphosphonate (MDP) labelled with radioactive pertechnetate (99mTcO4-) to evaluate the inflammatory response and the local osteoblastic activity. The evolution of bone repair was additionally evaluated by light microscopy. RESULTS: Our results have shown that the highest bone activity was recorded between the 7th and the 14th day after surgery. The morphological analysis confirmed the results obtained with radioisotope analysis and did not reveal significant differences regarding the evolution of bone repair between the filled and the unfilled defects. CONCLUSION: We confirmed that 99mTc -MDP is a valuable tool to study bone repair, as it was able to show subtle alterations of bone activity even in lesions as small as those created herein (0.5 mm wide, 0.5 mm deep).

Indicaçöes clínicas do uso de corticosteróides em Odontologia: estado atual da questäo / Clinical indications of corticosteroids use in Dentistry

Os autores discutem os efeitos farmacológicos e adversos dos corticosteróides e as suas indicaçöes em Odontologia, bem como os cuidados durante a sua prescriçäo