Metallic crown-induced occlusal trauma as a protocol to evaluate inflammatory response in temporomandibular joint and periodontal tissues of rats.

OBJECTIVES: The goal of this study is to propose a standard protocol of experimental occlusal trauma to evaluate the inflammatory hyperalgesia induced by metallic crowns on orofacial tissues of rats. MATERIALS AND METHODS: Thirty animals were randomly divided into six groups (n = 5 per group). Detailed methodology on the manufacturing of metallic crowns is described. The inflammatory hyperalgesia induced by occlusal interference was evaluated by intra-articular injection of a low dose of 0.5% formalin (30 µl) or vehicle (saline) into temporomandibular joint, 21 or 28 days after metallic crown cementation. Posteriorly, pro-inflammatory cytokines were evaluated by enzyme-linked immunosorbent assay to assess the effect of occlusal interference on periodontium. RESULTS: The cementation of metallic crowns with dental anatomy on the lower molar of rats does not show signs of stress and lack of feeding. Metallic crown-induced occlusal trauma results in a temporomandibular joint inflammatory hyperalgesia (P < 0.05: ANOVA, Tukey's test). Otherwise, it was observed that occlusal trauma results in the increase of protein level of pro-inflammatory cytokines TNF-alpha and IL-1beta in the gingival tissues (P < 0.05). CONCLUSION: This study demonstrates in detail a methodology of occlusal trauma resulting from the cementation of metallic crowns in the lower molars of rats, mimicking occlusal interferences commonly evaluated in the dental clinic. This methodology makes new studies to better understand the mechanisms involved in the occlusal trauma of orofacial tissues possible. CLINICAL RELEVANCE: The standardization of an experimental occlusal interference model will allow us to understand the deleterious effect and mechanisms that affect the orofacial tissues.

Increasing Access to Medical Care for Hispanic Women Without Insurance: A Mobile Clinic Approach.

The purpose of this study was to describe the health status and barriers of people who sought care on a free mobile health clinic for women without insurance in California. Participants were 221 women who attended the Salud para Mujeres (Women's Health) mobile medical clinic between 2019 and 2021. Medical chart abstractions provided data on sociodemographic factors, medical history, barriers to care, depressive symptoms, and dietary factors. Anthropometric measure, blood pressure, and biomarkers of cardiometabolic disease risk were also abstracted. Participants were young adult (29.1 [SD 9.3] years), Hispanic (97.6%), farm-working (62.2%) women from Mexico (87.0%). Prevalent barriers to accessing (non-mobile) medical care included high cost (74.5%), language (47.6%), hours of operation (36.2%), and transportation (31.4%). The majority (89.5%) of patients had overweight (34.0%) or obesity (55.5%), and 27% had hypertension. Among those (n = 127) receiving a lipid panel, 60.3% had higher than recommended levels of low-density lipoprotein and 89% had lower than recommended levels of high-density lipoprotein. Point-of-care HbA1c tests (n = 133) indicated that 9.0% had diabetes and 24.8% had prediabetes. Over half (53.1%) of patients reported prevalent occupational exposure to pesticides and 19% had moderate to severe depressive symptoms. Weekly or more frequent consumption of sugar sweetened beverages (70.9%) and fast food (43.5%) were also prevalent. Mobile health units have potential for reaching women who face several barriers to care and experience major risk factors for cardometabolic disease. Findings suggest a compelling need to assure that Hispanic and Indigenous women and farmworkers have access to healthcare.

Quercetin inhibits inflammatory bone resorption in a mouse periodontitis model.

Periodontitis is a disease that leads to bone destruction and represents the main cause of tooth loss in adults. The development of aggressive periodontitis has been associated with increased inflammatory response that is induced by the presence of a subgingival biofilm containing Aggregatibacter actinomycetemcomitans. The flavonoid quercetin (1) is widespread in vegetables and fruits and exhibits many biological properties for possible medical and clinical applications such as its anti-inflamatory and antioxidant effects. Thus, in the present study, the properties of 1 have been evaluated in bone loss and inflammation using a mouse periodontitis model induced by A. actinomycetemcomitans infection. Subcutaneous treatment with 1 reduced A. actinomycetemcomitans-induced bone loss and IL-1ß, TNF-α, IL-17, RANKL, and ICAM-1 production in the gingival tissue without affecting bacterial counts. These results demonstrated that quercetin exhibits protective effects in A. actinomycetemcomitans-induced periodontitis in mice by modulating cytokine and ICAM-1 production.

Mi Gente, Nuestra Salud: Protocol for a People's Movement for Health Ownership.

BACKGROUND: Community-based participatory research (CBPR) is an increasingly recognized approach to address health inequities. Although in CBPR all processes occur within the community context, its diagrammatic model places the intervention/research outside of the community rather than conceptualizing it as an event in a complex web of system components. OBJECTIVES: We sought to 1) introduce a systems-oriented community ownership conceptual framework that integrates a systems perspective with CBPR and 2) to describe an application of this framework in the form of the Mi Gente, Nuestra Salud initiative, a research-based, action-oriented collaboration between Cal Poly investigators and community partners in Santa Maria and Guadalupe, California. METHODS: We conducted a stocktake of community assets and partnerships in Santa Maria and Guadalupe, among California's poorest and most medically underserved cities; created marketing materials; launched the initiative in December 2020; and collected survey and interview data on community health concerns. An advisory board guides direction of the work. Activities are intended to affect partnerships (who is involved in actions and decisions) and processes (what actions will be taken), as well as resources (e.g., building human and social capital by changing narratives of local, historically rooted power dynamics and offering peer learning opportunities on advocacy and health care interactions). Implementation challenges within this framework are also discussed. CONCLUSIONS: By de-centering specific interventions and conceptualizing them as single events in a complex web, our system-oriented community ownership model brings the focus back to the system itself, and to system-based processes and solutions, while still guided by CBPR principles.

P2X7-induced nociception in the temporomandibular joint of rats depends on inflammatory mechanisms and C-fibres sensitization.

BACKGROUND: P2X7 receptors are responsible for triggering inflammatory responses contributing to processes of pain in articular tissues. This study aimed to investigate whether the activation of the P2X7 receptor located in the temporomandibular joint (TMJ) tissues induces nociception through an inflammatory mechanisms and/or the activation of C-fibres (small-diameter primary afferents) of rats' TMJ. METHODS: The TMJ hypernociception induced by the activation of P2X7 receptor was assessed by measuring the behavioural nociceptive responses. After behavioural experiments, the animals were terminally anaesthetized and periarticular tissues were removed and homogenate for enzyme-linked immunosorbent assay, leukocyte infiltration and western blotting analysis. RESULTS: The nonselective P2X7 receptor agonist BzATP induced a dose-dependent TMJ nociception, which was blocked by the selective P2X7 receptor antagonist A-438079. The co-administration of the selective ß2-adrenoceptor antagonist (ICI-118,551) and the pre-treatment with cyclooxygenase inhibitor indomethacin or with the nonspecific selectin inhibitor Fucoidan significantly reduced BzATP-induced TMJ nociception. BzATP also induced an increase of pro-inflammatory cytokines TNFα, IL-1ß and CINC-1 levels, as well as leukocyte recruitment in TMJ tissue, effects that were reduced by A-438079. Moreover BzATP-induced TMJ nociception was inhibited in rats neonatal-treated with Capsaicin (depleting C-fibers). Finally, BzATP-induced an increase in TRPV1 expression in TMJ tissue. CONCLUSIONS: These findings suggest that P2X7 receptor activation in TMJ of rats induces nociceptive responses mediated by sympathomimetic amines, prostaglandins, leukocyte migration and increased levels of pro-inflammatory cytokines. Furthermore, the P2X7 receptor activation induces nociceptive responses dependent on the activation of the primary afferent nociceptors of rats' TMJ. SIGNIFICANCE: The activation of P2X7 receptors has an essential role in TMJ nociception and could be an interesting target to control the inflammatory pain in temporomandibular disorders.

Saline nebulization before gastric lavage in the diagnosis of pulmonary tuberculosis in children and adolescents.

The main objective is to assess whether nebulization before gastric lavage (GL) improves its sensitivity for the diagnosis of childhood tuberculosis (TB). Children and adolescents suspected of pulmonary TB were randomly assigned (1 : 2) to nebulization with hypertonic saline 30 min before GL (Neb group; n = 36) or GL without prior nebulization (controls; n = 68). The proportion of positive GL smears was greater in Neb group than in the control group; however, no statistical significance was observed (36.3% vs. 22.2%; p = 0.4). Inhalation of nebulized hypertonic saline before GL did not improve TB diagnosis in this study. Nevertheless, the validation of our data will require large longitudinal studies.

Poloxamer micellar system for intra-articular injection of 15-deoxy-Δ12,14-prostaglandin J2 with improved bioavailability and anti-inflammatory properties in the temporomandibular joint of rats.

Painful conditions of the temporomandibular joint (TMJ) are challenging to manage and most attempts often result in unsatisfactory outcomes. In such context, nanocarrier systems, such as polymeric micelles, have been showing encouraging results in solving therapeutic limitations. Poloxamers are widely used, especially PL 407, because of their high biocompatibility and approval by the Food and Drug Administration (FDA) for clinical use. 15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) has shown important antinociceptive and anti-inflammatory activity. The present study evaluated the efficacy and viability of the micellar system of PL-15dPGJ2 in a formalin-induced acute pain model in the temporomandibular joint of rats. The PL-15dPGJ2 was prepared and characterized. The animals were pretreated with an intra-articular injection of PL-15dPGJ2 followed by the formalin challenge. The nociceptive response was evaluated at different time-periods and the periarticular tissue and articular wash were collected for analysis. We found that intra-articular injection of PL-15d-PGJ2 produced pain relief at lower concentrations and in a sustained manner compared with free 15d-PGJ2. Moreover, a strong anti-inflammatory effect was observed with decreased levels of key pro-inflammatory cytokines and modulation of the leukocyte migration process. Our findings suggest that 15d-PGJ2 combined with a poloxamer micellar system provided clinical relevance in terms of bioavailability, long-lasting effect, and safe dosage. The formulation investigated herein is a promising micellar carrier system for managing pain conditions of the TMJ.

Early Phase of Type 1 Diabetes Decreases the Responsiveness of C-Fiber Nociceptors in the Temporomandibular Joint of Rats.

Diabetes is a chronic degenerative disease that represent a major threat to public health worldwide. Once the disease is established, one of the major concerns about the diabetes complications is the development of neuropathy. This study established an experimental model that evaluates the effect of type 1 diabetes on nociceptive challenges in the temporomandibular joint (TMJ). Streptozotocin-induced type 1 (STZ 75 mg/Kg) diabetes inhibited the responsiveness of C-fibers nociceptors located in the TMJ of Wistar rats since seventh day after the disease induction. Diabetes-induced hyporesponsiveness of C-fibers nociceptors was associated with significantly reduction of protein level of neuropeptides Substance P and Calcitonin Gene Related Peptide. Diabetic animals pre-treated with Protein Kinase C (PKC)-α and -ß inhibitor (GO6976) or PKC-ß inhibitor (LY333531) significantly increased capsaicin-induced nociception in the TMJ higher protein levels of Na+/K+-ATPase pump in the trigeminal ganglia. On the other hand, although diabetes inhibits formalin-induced nociception higher protein levels of pro-inflammatory cytokine IL1-ß and chemokine CINC-1/CXCL-1 were observed. Overall, the results of the present work suggest that diabetes causes a hyporesponsiveness of C-fiber and a potentialization of the inflammatory response which may result in the degenerative process of periarticular tissues without pain perception.

The 15d­PGJ2 hydrogel ameliorates atopic dermatitis through suppression of the immune response.

The present study examined the efficacy of the topical 15d­PGJ2­poloxamer 407 hydrogel in an atopic dermatitis (AD) animal model. The 15d­PGJ2 hydrogel was prepared and characterized. The examined rats possessed AD­Like cutaneous lesions, which were induced using 2,4­dinitrochlorobenzene, the rats were then treated with a hydrogel vehicle, 15d­PGJ2 hydrogel or tacrolimus for 14 days. The rats were sacrificed and blood samples were collected to quantify the IgE levels. Subsequently, skin biopsies were stained with toluidine blue to identify mast cells and immunohistochemistry was performed for ROR­Î³t and TNF­α. Histological analyses demonstrated that 15d­PGJ2 hydrogel significantly decreased mast cell infiltration (P<0.05) when compared with the AD­group. Tacrolimus at 0.1% exhibited decreased mast cell infiltration; however, this difference was not statistically significant from the AD­group. Topical 15d­PGJ2 hydrogel and Tacrolimus 0.1% significantly reduced the serum levels of IgE (P<0.05) compared with the AD­group. Immunohistochemistry revealed a significant decrease in ROR­Î³t and TNF­α positive cell expression (P<0.05) in the 15d­PGJ2 hydrogel group compared with the AD­group. In summary, topical administration of 15d­PGJ2 hydrogel had a beneficial effect on AD symptoms, suggesting that this formulation may be a useful strategy for the treatment of AD.

Improved efficacy of naproxen-loaded NLC for temporomandibular joint administration.

Inflammatory conditions of the temporomandibular joint (TMJ) and peripheral tissues affect many people around the world and are commonly treated with non-steroidal anti-inflammatory drugs (NSAIDs). However, in order to get desirable results, treatments with NSAIDs may take weeks, causing undesirable side effects and requiring repeated administration. In this sense, this work describes the development of an optimized nanostructured lipid carrier (NLC) formulation for intra-articular administration of naproxen (NPX). An experimental design (23) selected the best formulation in terms of its physicochemical and structural properties, elucidated by different methods (DLS, NTA, TEM, DSC, and ATR-FTIR). The chosen formulation (NLC-NPX) was tested on acute inflammatory TMJ nociception, in a rat model. The optimized excipients composition provided higher NPX encapsulation efficiency (99.8%) and the nanoparticles were found stable during 1 year of storage at 25 °C. In vivo results demonstrated that the sustained delivery of NPX directly in the TMJ significantly reduced leukocytes migration and levels of pro-inflammatory cytokines (IL-1ß and TNF-α), for more than a week. These results point out the NLC-NPX formulation as a promising candidate for the safe treatment of inflammatory pain conditions of TMJ or other joints.

The P2X7 Receptor, Cathepsin S and Fractalkine in the Trigeminal Subnucleus Caudalis Signal Persistent Hypernociception in Temporomandibular Rat Joints.

Temporomandibular joint (TMJ) is frequently involved with rheumatoid arthritis with a high prevalence that could result in a chronic pain state. Once the disease is established in the joint, the antigen-specific immune reaction initiates a neuro-immune cascade of events that causes sensitization of the central nervous system. This study establishes animal experimental models that evaluate the chronicity of albumin-induced arthritis hypernociception in the TMJ. Antigen-induced arthritis was generated in rats with methylated bovine serum albumin (mBSA) diluted in complete Freund's. Intra-articular injection of mBSA (10 µg/TMJ/week) during 3 weeks resulted in a persistent inflammatory hypernociception which was characterized by an inflammatory episode characterized by the increased of lymphocytes, macrophages and pro-inflammatory interleukins IL-12 and IL-18. The persistent model of inflammatory hypernociception induced by arthritis in the TMJ elicited protein levels of P2X7 receptors, cathepsin S and fractalkine in the trigeminal subnucleus caudalis. Overall, the results of the present work suggest that a persistent inflammatory hypernociception of albumin-induced arthritis in the TMJ leads to the activation of the central nervous system signaling by P2X7/cathepsin S/fractalkine pathway.

Analysis of the perinatal mortality rate in the metropolitan region of grande Vitória, Espírito Santo, Brazil, between 2008 and 2017

Introduction: perinatal mortality is characterized by fetal deaths that occur after the 22nd week of management and neonatal deaths that precede six full days of life. This indicator has been a matter of concern and discussion on the part of entities and organizations involved in comprehensive health care for women and children.Objective: to characterize perinatal deaths in the Metropolitan Region of Greater Vitória (RMGV) in Espírito Santo and identify associated maternal factors in the period between 2008 and 2017.Methods: ecological and descriptive study with a quantitative approach, carried out in 2019 on perinatal mortality from 2008 to 2017 at RMGV. Data collection was performed by extracting data from the SIM, SINASC, IBGE databases of the Espírito Santo State Health Department, about perinatal deaths and associated maternal factors. The research respects the ethical precepts of resolution 466/12 of the National Health Council.Results: the distribution of deaths did not occur homogeneously in the municipalities in the RMGV. The municipality of Vitória had the lowest perinatal mortality rates during the study period, on the other hand, in the comparative analysis between the different municipalities that make up the RMGV, the municipality of Fundão presents the worst scenario regarding perinatal mortality over the years. Regarding the underlying causes of death, it is noted that in this study, the three causes with the highest number of occurrences are complications of the placenta, umbilical cord and maternal affections, not necessarily related to the current pregnancy and intrauterine hypoxia.Conclusion: there were no significant changes in mortality rates in the Metropolitan Region of Greater Vitória. However, the main deaths occurred in neighborhoods with greater socioeconomic inequalities. Maternal causes were highly representative of deaths, raising issues associated with the improvement of public health policies.

Introdução: a mortalidade perinatal caracteriza-se pelos óbitos fetais que ocorrem a partir da 22ª semana de gestão e os óbitos neonatais que antecedem seis dias completos de vida. Este indicador tem sido motivo de preocupação e discussão por parte de entidades e organizações envolvidas na atenção à saúde integral da mulher e da criança. Objetivo: caracterizar os óbitos perinatais da Região Metropolitana da Grande Vitória (RMGV) no Espírito Santo e identificar fatores maternos associados, no período entre 2008 e 2017. Método: estudo ecológico e descritivo de abordagem quantitativa, realizado no ano de 2019 acerca da mortalidade perinatal entre os anos de 2008 a 2017 na RMGV. A coleta de dados foi realizada através extração dos dados das bases SIM, SINASC, IBGE da Secretaria de Saúde do Estado do Espírito Santo, acerca dos óbitos perinatais e fatores maternos associados. A pesquisa respeita os preceitos éticos da resolução 466/12 do Conselho Nacional de Saúde. Resultados: a distribuição dos óbitos não ocorreu de forma homogênea nos municípios na RMGV. O município de Vitória apresentou os menores índices de mortalidade perinatal durante o período estudado, em contrapartida, na análise comparativa entre os diferentes municípios que compõe a RMGV, o município de Fundão apresenta o pior cenário relativo à mortalidade perinatal ao longo dos anos. Acerca das causas bases de óbitos, nota-se que neste estudo, as três causas com maior número de ocorrência são complicações da placenta, do cordão umbilical e afecções maternas, não obrigatoriamente relacionadas com a gravidez atual e hipóxia intrauterina. Conclusão: não houve mudanças significativas nas taxas de mortalidade na Região Metropolitana da Grande Vitória. Contudo, os principais óbitos ocorreram em bairros com maiores desigualdades socieconomicas. As causas maternas representaram uma grande representatividade frente aos óbitos, levantando questões associadas a melhora de políticas públicas de saúde.

Botulinum toxin type A reduces inflammatory hypernociception induced by arthritis in the temporomadibular joint of rats.

OBJECTIVE: This study aimed to investigate the antinociceptive effects of Botulinum toxin type A (BoNT-A) on persistent inflammatory hypernociception induced by arthritis in the temporomandibular joint (TMJ) of rats. MATERIAL AND METHODS: Wistar rats were induced to persistent inflammatory hypernociception in the left TMJ. Then, animals were treated with intra-TMJ injections of BoNT-A, using doses of 3.5, 7 and 14 U/kg. Saline was used as control group. Behavioral tests were applied to evaluated the effect of BoNT-A in the inflammatory hypernociception. After that, animals were euthanized and samples from peri-articular tissues and trigeminal ganglia were obtained for further analyses. RESULTS: BoNT-A reduced the persistent inflammatory hypernociception induced by arthritis in the TMJ of rats. BoNT-A significantly reduced the peripheral release of the neurotransmitters Substance P and Calcitonin gene related peptide; and the pro-inflammatory cytokine IL-1ß. Otherwise, BoNT-A had no effect in the peripheral release of glutamate and the cytokine TNF-α. CONCLUSION: These results demonstrate that intra-articular injection of BoNT-A reduces the albumin-induced arthritis persistent hypernociception in TMJ of rats by peripheral inhibition of neuropeptides release.

Microneedles enhance topical delivery of 15-deoxy-Δ12,14-prostaglandin J2 and reduce nociception in temporomandibular joint of rats.

The pain arising from temporomandibular disorders is often treated with opioids and agents that inhibit the immune response and are associated with substantial adverse effects and long-term risks. Thus, the development of new therapies that are safer and more effective is of great interest to patients and clinicians. 15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) is naturally produced in the human body and has anti-inflammatory properties. We have previously shown in a rat temporomandibular joint (TMJ) model that injection of 15d-PGJ2 into the rat TMJ can provide antinociceptive relief against a subsequent noxious challenge from formalin injection into the same TMJ. However, intra-TMJ injections are painful. Thus, to make the treatment patient friendly, this study aimed to evaluate whether the antinociceptive property of 15d-PGJ2 cream can be enhanced with microneedles (MNs). We found that topical application of 15d-PGJ2 cream for 15min directly on the rat TMJ skin did not induce any significant antinociceptive effect. However, if MNs were inserted in the skin for 5min, removed, and then 15d-PGJ2 cream was applied, a significant reduction in formalin-induced nociceptive behavior was observed. This reduction in nociception was comparable to an intra-TMJ injection of 15d-PGJ2. A concentration-dependent effect of 15d-PGJ2 was observed, with higher concentrations of 15d-PGJ2 in the cream showing a more durable effect up to 8h. 15d-PGJ2 cream associated with MNs also significantly reduced the release of tumor necrosis factor-α and interleukin-1 beta, which are pro-inflammatory cytokines. Our findings suggest that 15d-PGJ2 cream associated with MNs provides antinociceptive and anti-inflammatory effect, and can offer a potential patient-friendly therapeutic option for pain control related to inflammatory disorders of the TMJ.

The anti-inflammatory effect of tramadol in the temporomandibular joint of rats.

Tramadol is a centrally acting analgesic drug able to prevent nociceptor sensitization when administered into the temporomandibular joint (TMJ) of rats. The mechanism underlying the peripheral anti-inflammatory effect of tramadol remains unknown. This study demonstrated that intra-TMJ injection of tramadol (500µg/TMJ) was able to inhibit the nociceptive response induced by 1.5% formalin or 1.5% capsaicin, suggesting that tramadol has an antinociceptive effect, acting directly on the primary nociceptive neurons activating the nitric oxide/cyclic guanosine monophosphate signaling pathway. Tramadol also inhibited the nociceptive response induced by carrageenan (100µg/TMJ) or 5-hydroxytryptamine (225µg/TMJ) along with inhibition of inflammatory cytokines levels, leukocytes migration and plasma extravasation. In conclusion, the results demonstrate that peripheral administration of tramadol has a potential antinociceptive and anti-inflammatory effect. The antinociceptive effect is mediated by activation of the intracellular nitric oxide/cyclic guanosine monophosphate pathway, at least in part, independently from the opioid system.

Simvastatin modulates gingival cytokine and MMP production in a rat model of ligature-induced periodontitis.

PURPOSE: The aim of this study was to evaluate the effect of simvastatin on the synthesis of cytokines TNF-α and IL-10 and metalloproteinase (MMPs) 2 and 9 in a rat model of ligature-induced periodontitis. MATERIALS AND METHODS: Twenty Wistar rats were used, and a cotton ligature was place in a subgingival position encircling the entire cervix of the first molar of the left (ipsilateral) side of the mandible. The right (contralateral) side of the mandible had no ligature placed and was used as control. After the ligature placement, animals were randomly assigned to two experimental groups (n=10): 1) rats with ligature + vehicle (saline; 10 mL/kg; orally) and 2) rats with ligature + simvastatin (25 mg/kg; orally). After 14 days of treatment, the animals were euthanized by anesthetic overdose and the gingival tissue was removed and homogenized in appropriate buffer. MMP-2 and -9 release as well as the IL-10 and TNF-α levels were detected by enzyme-linked immunosorbent assay. Statistical comparison was performed by unpaired Student's t-test, with p<0.05 representing significance. RESULTS: No differences were observed for TNF-α production between the groups (p>0.05). However, IL-10 was upregulated in simvastatin-treated animals (1.8-fold increase) in comparison with the vehicle-treated group (p<0.05). Simvastatin reduced the gingival levels of MMP-9 (64.3%) in comparison with vehicle-treated samples (p<0.05). CONCLUSION: Oral treatment with simvastatin increased the release of IL-10 and reduced the MMP-9 in ligature-induced periodontitis model in rats.

Coactivation of µ- and κ-Opioid Receptors May Mediate the Protective Effect of Testosterone on the Development of Temporomandibular Joint Nociception in Male Rats.

AIMS: To investigate whether the protective effect of testosterone on the development of temporomandibular joint (TMJ) nociception in male rats is mediated by the activation of central opioid mechanisms. METHODS: Experiments were performed on 156 male Wistar rats. A pharmacologic approach was used to assess the ability of opioid receptor antagonists infused into the dorsal portion of the brainstem and adjacent to the caudal component (subnucleus caudalis) of the spinal trigeminal nucleus to block the protective effect of testosterone in male rats. The TMJ injection of 0.5% formalin was used as a nociceptive stimulus. One-way or two-way ANOVA was used for data analyses. RESULTS: The injection of 0.5% formalin into the TMJ induced a significant nociceptive behavior in gonadectomized male rats (P < .05), but not in naïve, sham, and testosterone-replaced gonadectomized rats, confirming that testosterone prevents the development of TMJ nociception. The injection of either the nonselective opioid receptor antagonist naloxone (15 µg) or the simultaneous injection of the µ-opioid receptor antagonist Cys2, Tyr3, Orn5, Pen7amide (CTOP, 30 µg) and the κ-opioid receptor antagonist Nor-Binaltorphimine (Nor-BNI, 90 µg) significantly increased the 0.5% formalin-induced behavioral response in sham and testosterone-replaced gonadectomized rats (P < .05) but had no effect in gonadectomized rats. However, the injection of each selective opioid receptor antagonist alone or the simultaneous injection of µ- or κ- and δ-opioid receptor antagonists had no effect. CONCLUSION: These findings indicate that the protective effect of endogenous testosterone on the development of TMJ nociception in male rats is mediated by the activation of central opioid mechanisms. Furthermore, the coactivation of central µ- and κ-opioid receptors is necessary for testosterone to protect male rats from developing TMJ nociception.

Influence of salivary washout on drug delivery to the oral cavity using coated microneedles: An in vitro evaluation.

The objective of this study was to determine whether in buccal tissues, after insertion and removal of coated microneedles, the presence of saliva over the insertion site can lead to loss of the deposited drug, and if saliva can influence in vitro permeation of the drug across the tissue. Microneedles were coated with sulforhodamine (SRD), which was used as a model drug, and inserted in to porcine buccal mucosa in vitro. Fluorescence microscopy was used to study microneedle coating quality and the diffusion of SRD through the mucosa. Permeation experiments were conducted for simulated dynamic or static salivary flow by adding 100µL/h or 100, 200 or 300µL of phosphate buffered saline (PBS) in the donor compartment of the Franz diffusion cells, into which buccal tissue after insertion of SRD-coated microneedles was placed. Microscopy showed that microneedles were uniformly coated with SRD and that SRD was successfully delivered in to the mucosa. Some SRD remained in the tissue even after 24h, despite presence of PBS on top of the coated microneedle insertion site. It was found that salivary washout can result in loss of drug that has been deposited in oral cavity mucosal tissues using coated microneedles, and presence of fluid over the coated microneedle insertion site can increase flux across the tissue. Thus, it is advisable to include salivary flow during in vitro studies related to the use of coated microneedles for drug delivery to the oral cavity in order to not obtain misleading results.

15d-PGJ2-Loaded Solid Lipid Nanoparticles: Physicochemical Characterization and Evaluation of Pharmacological Effects on Inflammation.

15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2), a peroxisome proliferator-activated receptor-γ (PPAR-γ) agonist, has physiological properties including pronounced anti-inflammatory activity, though it binds strongly to serum albumin. The use of solid lipid nanoparticles (SLN) can improve therapeutic properties increasing drug efficiency and availability. 15d-PGJ2-SLN was therefore developed and investigated in terms of its immunomodulatory potential. 15d-PGJ2-SLN and unloaded SLN were physicochemically characterized and experiments in vivo were performed. Animals were pretreated with 15d-PGJ2-SLN at concentrations of 3, 10 or 30 µg·kg-1 before inflammatory stimulus with carrageenan (Cg), lipopolysaccharide (LPS) or mBSA (immune response). Interleukins (IL-1ß, IL-10 and IL-17) levels were also evaluated in exudates. The 15d-PGJ2-SLN system showed good colloidal parameters and encapsulation efficiency of 96%. The results showed that the formulation was stable for up to 120 days with low hemolytic effects. The 15d-PGJ2-SLN formulation was able to reduce neutrophil migration in three inflammation models tested using low concentrations of 15d-PGJ2. Additionally, 15d-PGJ2-SLN increased IL-10 levels and reduced IL-1ß as well as IL-17 in peritoneal fluid. The new 15d-PGJ2-SLN formulation highlights perspectives of a potent anti-inflammatory system using low concentrations of 15d-PGJ2.

Evidence of field-evolved resistance of Spodoptera frugiperda to Bt corn expressing Cry1F in Brazil that is still sensitive to modified Bt toxins.

Brazil ranked second only to the United States in hectares planted to genetically modified crops in 2013. Recently corn producers in the Cerrado region reported that the control of Spodoptera frugiperda with Bt corn expressing Cry1Fa has decreased, forcing them to use chemicals to reduce the damage caused by this insect pest. A colony of S. frugiperda was established from individuals collected in 2013 from Cry1Fa corn plants (SfBt) in Brazil and shown to have at least more than ten-fold higher resistance levels compared with a susceptible colony (Sflab). Laboratory assays on corn leaves showed that in contrast to SfLab population, the SfBt larvae were able to survive by feeding on Cry1Fa corn leaves. The SfBt population was maintained without selection for eight generations and shown to maintain high levels of resistance to Cry1Fa toxin. SfBt showed higher cross-resistance to Cry1Aa than to Cry1Ab or Cry1Ac toxins. As previously reported, Cry1A toxins competed the binding of Cry1Fa to brush border membrane vesicles (BBMV) from SfLab insects, explaining cross-resistance to Cry1A toxins. In contrast Cry2A toxins did not compete Cry1Fa binding to SfLab-BBMV and no cross-resistance to Cry2A was observed, although Cry2A toxins show low toxicity to S. frugiperda. Bioassays with Cry1AbMod and Cry1AcMod show that they are highly active against both the SfLab and the SfBt populations. The bioassay data reported here show that insects collected from Cry1Fa corn in the Cerrado region were resistant to Cry1Fa suggesting that resistance contributed to field failures of Cry1Fa corn to control S. frugiperda.