Experimental Model of Zymosan-Induced Arthritis in the Rat Temporomandibular Joint: Role of Nitric Oxide and Neutrophils

Aims. To establish a new model of zymosan-induced temporomandibular joint (TMJ) arthritis in the rat and to investigate the role of nitric oxide. Methods. Inflammation was induced by an intra-articular injection of zymosan into the left TMJ. Mechanical hypernociception, cell influx, vascular permeability, myeloperoxidase activity, nitrite levels, and histological changes were measured in TMJ lavages or tissues at selected time points. These parameters were also evaluated after treatment with the nitric oxide synthase (NOS) inhibitors L-NAME or 1400 W. Results. Zymosan-induced TMJ arthritis caused a time-dependent leucocyte migration, plasma extravasation, mechanical hypernociception, and neutrophil accumulation between 4 and 24 h. TMJ immunohistochemical analyses showed increased inducible NOS expression. Treatment with L-NAME or 1400 W inhibited these parameters. Conclusion. Zymosan-induced TMJ arthritis is a reproducible model that may be used to assess both the mechanisms underlying TMJ inflammation and the potential tools for therapies. Nitric oxide may participate in the inflammatory temporomandibular dysfunction mechanisms

Effects of a sulfated polysaccharide isolated from the red seaweed Solieria filiformis on models of nociception and inflammation

AbstractThis work reports the effects of a sulfated polysaccharide (SP-Sf), isolated from the seaweed Solieria filiformis and characterized by Fourier transformed infrared (FT-IR), on nociception and inflammation. Male Swiss mice were pretreated with SP-Sf 30min before receiving an injection of 0.8% acetic acid, 1% formalin or 30min prior to a thermal stimulus. We observed that SP-Sf (1, 3 or 9mg/kg) significantly reduced the number of writhes. SP-Sf also reduced the second phase of the formalin test and did not cause a significant antinociceptive effect in the hot plate test, suggesting that its antinociceptive action occurs through a peripheral mechanism. SP-Sf (1, 3 or 9mg/kg) did not show a significant anti-inflammatory effect in Wistar rats when administrated by the systemic route 1h before testing using carrageenan or dextran. Finally, SP-Sf (9mg/kg) did not show significant signs of toxicity when administrated in mice

Occurrence and antimicrobial susceptibility of enteric rods and pseudomonads isolated from the dental prostheses biofilm

ABSTRACT Aspiration of oral bacteria leads to cardiac and respiratory infectious diseases and dentures can act as a reservoir for pathogenic microorganisms. Objective: To determine the occurrence and the in vitro antimicrobial susceptibility of enteric rods and pseudomonads from the denture biofilm of 52 subjects at the Center for Dental Specialties of Sobral/ Ceara, Brazil. Material and Methods: Denture biofilm was collected and samples plated on MacConkey agar. The isolated bacterial colonies were identified using the BBL Crystal enteric/non-fermenter system. Antibiotic bacterial susceptibility was assessed by the disc diffusion method of amoxicillin, amoxicillin/clavulanic acid, doxycycline, tetracycline, tobramycin, imipenem, cefotaxime, and ciprofloxacin. The Minimum Inhibitory Concentration (MIC) of cefotaxime, tobramycin, doxycycline, imipenem, and ciprofloxacin was determined for 40 species by E-test. Results: 34 subjects (65.4%) harbored enteric rods in their prostheses. Klebsiella pneumoniae (26.5%), Escherichia coli (23.5%), and Enterobacter aerogenes (23.5%) were the most prevalent species. All organisms were susceptible to ciprofloxacin and most species were resistant to amoxicillin or amoxicillin/clavulanic acid, demonstrating variable sensitivity patterns to other antimicrobials. However, the MIC showed the emergence of strains with reduced sensitivity to ciprofloxacin (MIC90≥3 μg/ mL) and cefotaxime (MIC90≥2 μg/mL). Conclusion: The findings show high prevalence of nosocomial diseases-related bacterial species and low susceptibility to antimicrobial drugs. Therefore, these results imply caution against the indiscriminate use of broad spectrum antibiotics in dental practice

<b>Structural features and assessment of zymosan-induced arthritis in rat temporomandibular joint model using sulfated polysaccharide

The green seaweed Caulerpa cupressoides var. lycopodium contains three SPs fractions (Cc-SP1, Cc-SP2 and Cc-SP3). Cc-SP1andCc-SP2 had anticoagulant (in vitro), pro- and antithrombotic, antinociceptive and/or anti-inflammatory (in vivo) effects. This study analyzed structural features and the antinociceptive and anti-inflammatory effects of Cc-SP1 on zymosan-induced acute arthritis of the rat temporomandibular joint (TMJ). Cc-SP1 was investigated by infrared technique. Male Wistar rats (200-240 g) received subcutaneously (s.c.) Cc-SP1 1h prior to intra-articular (i.art.) injection of zymosan (2 mg joint-1) or saline (0.9%) into the left TMJ. Mechanical hypernociception was measured by the electronic Von Frey method in the basal and 4h after zymosan injection. Animals were euthanized 6h after zymosan injection and the TMJ cavity was removed for total leukocyte counts from the synovial fluid and myeloperoxidase (MPO) activity assessment. Cc-SP1 (1, 3 or 9 mg kg-1) containing sulfate ester, galactose-6-sulfate, uronic acid and glycosidic linkages reduced zymosan-induced hypernociception (78.12, 81.13 and 87.43%, respectively, p < 0.01), and inhibited the total leukocyte influx (85, 88.14 and 89.95%, respectively, p < 0.01), being confirmed by MPO activity (p < 0.05). Therefore, Cc-SP1 reveals a pharmacological tool for treating inflammatory arthropathies

Facial representation of paroxysmal hemicrania and associated temporomandibular disorder: a case report

ABSTRACT Paroxysmal Hemicrania is a trigeminal autonomic cephalalgia described as a severe and strictly unilateral pain, which occurs in paroxysms at orbital, supraorbital and/ or temporal region. A 45-year-old woman presented to an orofacial pain specialist reporting severe, burning, throbbing, strictly right-sided headache associated to ipsilateral autonomic symptoms and orofacial pain. The pain was perceived on the maxillary region followed by pain spread to the head. Interdisciplinary evaluation, along with absolute responsiveness to indomethacin and normal Brain Magnetic Resonance imaging, led to the diagnosis of primary Episodic paroxysmal hemicrania with facial representation and myofascial pain of masticatory muscles. Dentists should be aware of paroxysmal hemicrania with facial representation and the possibility of temporomandibular disorder coexistence, in order to avoid misdiagnosis and inadequate management. Paroxysmal hemicrania may be first perceived on the face and may be associated with interparoxysmal pain. In these cases, efficient anamnesis and clinical evaluation followed by interdisciplinary approach is needed

Strontium Ranelate Elevates Expression of Heme Oxygenase-1 and Decreases Alveolar Bone Loss in Rats

Objectives: The purpose of this study was to determine the effects of strontium ranelate on ligature-induced periodontitis in rats and assess the putative involvement of heme oxygenase-1 (HO-1) pathway in these effects. Material and Methods: Male Wistar rats underwent nylon ligature placement around maxillary molars and were treated (v.o.) with strontium ranelate (20 or 100 mg/kg) for 7 days. After that, rats were euthanized and histomorphometric/histopathological analyses and RT-PCR for HO-1 expression were performed. Results: Strontium ranelate (20 or 100 mg/kg) prevented bone resorption by 28% and 38%, respectively. Strontium ranelate treatment (100 mg/kg) up-regulated (P < 0.05) heme oxygenase-1 mRNA levels in the gingival tissues in comparison to control groups. Conclusions: Strontium ranelate prevented periodontal bone loss in experimental periodontitis in rats while heme oxygenase-1 mRNA levels increased after treatment

Occurrence and antimicrobial susceptibility of enteric rods and pseudomonads isolated from the dental prostheses biofilm

Aspiration of oral bacteria leads to cardiac and respiratory infectious diseases and dentures can act as a reservoir for pathogenic microorganisms. Objective: To determine the occurrence and the in vitro antimicrobial susceptibility of enteric rods and pseudomonads from the denture biofilm of 52 subjects at the Center for Dental Specialties of Sobral/ Ceara, Brazil. Material and Methods: Denture biofilm was collected and samples plated on MacConkey agar. The isolated bacterial colonies were identified using the BBL Crystal enteric/non-fermenter system. Antibiotic bacterial susceptibility was assessed by the disc diffusion method of amoxicillin, amoxicillin/clavulanic acid, doxycycline, tetracycline, tobramycin, imipenem, cefotaxime, and ciprofloxacin. The Minimum Inhibitory Concentration (MIC) of cefotaxime, tobramycin, doxycycline, imipenem, and ciprofloxacin was determined for 40 species by E-test. Results: 34 subjects (65.4%) harbored enteric rods in their prostheses. Klebsiella pneumoniae (26.5%), Escherichia coli (23.5%), and Enterobacter aerogenes (23.5%) were the most prevalent species. All organisms were susceptible to ciprofloxacin and most species were resistant to amoxicillin or amoxicillin/clavulanic acid, demonstrating variable sensitivity patterns to other antimicrobials. However, the MIC showed the emergence of strains with reduced sensitivity to ciprofloxacin (MIC90≥3 μg/ mL) and cefotaxime (MIC90≥2 μg/mL). Conclusion: The findings show high prevalence of nosocomial diseases-related bacterial species and low susceptibility to antimicrobial drugs. Therefore, these results imply caution against the indiscriminate use of broad spectrum antibiotics in dental practice