Influence of apoptosis on the cutaneous and peripheral lymph node inflammatory response in dogs with visceral leishmaniasis

In canine visceral leishmaniasis (CVL), the abnormalities most commonly observed in clinical examination on the animals are lymphadenomegaly and skin lesions. Dogs are the main domestic reservoir for the protozoon Leishmania (L.) chagasi and the skin is the main site of contamination by the vector insect. Some protozoa use apoptosis as an immunological escape mechanism. The aim of this study was to correlate the presence of apoptosis with the parasite load and with the inflammatory response in the skin and lymph nodes of dogs naturally infected with Leishmania (L.) chagasi. Thirty-three dogs from the municipality of Araçatuba (São Paulo, Brazil) were used, an endemic area for CVL. Muzzle, ear and abdominal skin and the popliteal, subscapular, iliac and mesenteric lymph nodes of symptomatic (S), oligosymptomatic (O) and asymptomatic (A) dogs were analyzed histologically. The parasite load and percentage apoptosis were evaluated using an immunohistochemical technique. Microscopically, the lymph nodes presented chronic lymphadenitis and the skin presented plasmacytic infiltrate and granulomatous foci in the superficial dermis, especially in the ear and muzzle regions. The inflammation was most severe in group S. The parasite load and apoptotic cell density were also greatest in this group. The cause of the lymphoid atrophy in these dogs was correlated with T lymphocyte apoptosis, thus leaving the dogs more susceptible to CVL. The peripheral lymph nodes presented the greatest inflammatory response. Independent of the clinical picture, the predominant inflammatory response was granulomatous and plasmacytic, both in the skin and in the peripheral lymph nodes. The ear skin presented the greatest intensity of inflammation and parasite load, followed by the muzzle skin, in group S. The ear skin area presented a non-significant difference in cell profile, with predominance of macrophages, and a significant difference from group A to groups O and S. It was seen that in these areas, there were high densities of parasites and cells undergoing apoptosis, in group S. The association between apoptosis and parasite load was not significant in the lymph nodes, but in the muzzle regions and at the ear tips, a positive correlation was seen between the parasite load and the density of cells undergoing apoptosis. The dogs in group S had the highest parasite load and the greatest number of apoptotic cells, thus suggesting that the parasite had an immune evasion mechanism, which could be proven statistically in the skin. © 2012 Elsevier B.V.

Histomorphometrical and molecular evaluation of endosseous dental implants sites in humans: Correlation with clinical and radiographic aspects

Objective: To evaluate the correlations between clinical-radiographical aspects and histomorphometric-molecular parameters of endosseous dental implant sites in humans. Material and methods: The study sample consisted of bone implant sites from the jawbones of 32 volunteers, which were classified according to two different systems: (1) based only on periapical and panoramic images (PP); (2) as proposed by Lekholm & Zarb (L&Z). Bone biopsies were removed using trephine during the first drilling for implant placement. Samples were stained with haematoxylin-eosin (HE), and histomorphometric analysis was performed to obtain the following parameters: trabecular thickness (Tb.Th), trabecular number, bone volume density (BV/TV), bone specific surface (BS/BV), bone surface density and trabecular separation (Tb.Sp). In addition, immunohistochemistry analysis was performed on bone tissue samples for the proteins, Receptor activator of nuclear factor kappa-B (RANK), RANK ligand (RANKL), osteoprotegerin (OPG) and Osteocalcin (OC). Also, the determination of the relative levels of gene expression was performed using Reverse transcription-real-time Polymerase Chain Reaction (RT-PCR). Results: PP and L&Z classification systems revealed a moderate correlation with BV/TV, BS/BV, Tb.Th and Tb.Sp. L&Z's system identified differences among bone types when BV/TV, BS/BV, Tb.Th and Tb.Sp were compared. A weak correlation between PP/L&Z classifications and the expression of bone metabolism regulators (RANK, RANKL, OPG e OC) was found. The analysis of mRNA expression showed no difference between the bone types evaluated. Conclusions: Our results suggest that PP and L&Z subjective bone-type classification systems are related to histomorphometric aspects. These data may contribute to the validation of these classifications. Bone remodelling regulatory molecules do not seem to influence morphological aspects of the jawbone © 2011 John Wiley & Sons A/S.

Deproteinized bovine bone mineral particles and osseointegration of implants without primary bone contact: An experimental study in dogs

Objectives: To evaluate the influence on osseointegration of Deproteinized bovine bone mineral (DBBM) particles used to fill defects of at least 1 mm around implants having no primary contact with bone. Material and methods: Premolars and first molars were extracted bilaterally from the mandible of six Labrador dogs. After 3 months of healing, mucoperiosteal full-thickness flaps were elevated, and one recipient site was prepared in the molar region of each hemi-mandible to place implants. These were installed with a deliberate circumferential and periapical space to the bone walls of 1.2 mm. All implants were stabilized with passive fixation plates to maintain the implants in situ and without any contact with the implant bed. The control sites were left to be filled with coagulum, while at the test sites, the residual gap was filled with DBBM. After 3 months of submerged healing, the animals were sacrificed. Ground sections were prepared and analyzed histomorphometrically. Results: Mineralized bone-to-implant contact was 4.0% and 3.9% for control and test sites, respectively. The width of the residual defects was 0.48 mm and 0.88 mm at the control and test sites, respectively. The percentage of implant surface covered by a layer of dense connective tissue of 0.12 mm of width on average was 84.9% and 88.5% at the control and test sites, respectively. Conclusion: A minor and not predictable degree of contact or distance osteogenesis was obtained on the implant surface when primary contact of the implant surface with the implant bed had deliberately been avoided. DBBM grafting of the artificial gap did not favor osseointegration. Neither did it enhance the ability to bridge the gap with newly formed bone in an artificial defect wider than 1 mm. © 2013 John Wiley & Sons A/S.

An approach to local immunotoxicity induced by adjuvanted vaccines

The occurrence of injection site reactions following immunization is the most frequently reported toxicity manifestation of vaccines; however, the different types of local reactions and the different mechanisms involved are still unclear. Here, the current advances in adjuvants and the role that adjuvants play in local reactions are reviewed. The role of adjuvants in the formation of the loco-regional complex (LRC), which consists of the injection site, draining lymphatic vessels and regional lymph nodes, is also discussed. Finally, strategies and recommendations for the rational design of adjuvanted vaccines are discussed, with a particular interest in the reduction of local inflammation. © 2013 Elsevier B.V.

Setting Time Affects In Vitro Biological Properties of Root Canal Sealers

Introduction: Biocompatibility of root canal sealers is important because of the long-term contact of their eluates and/or degradation products with periapical tissues. The literature still lacks studies about the genotoxic effects of these materials and the influence of setting time on biological properties. The cytotoxicity and genotoxicity of an epoxy resin-based sealer (AH Plus), a single methacrylate-based sealer (EndoRez), and a silicone-based sealer (RoekoSeal) were assessed. Methods: Chinese hamster fibroblasts (V79) were cultured and exposed to different dilutions of extracts from the sealers that were left to set for 0, 12, and 24 hours before contact with culture medium. Cell viability was measured by the methyl-thiazol-diphenyltetrazolium assay. Genotoxicity was assessed by the comet assay. Data were statistically analyzed by Kruskal-Wallis and Dunn tests (P < .05). Results: Root canal sealers were statistically more cytotoxic than the untreated control group, except for the silicon-based sealer. Cell viability ranking was the following (from the most to the least cytotoxic): methacrylate-based > epoxy resin-based > silicone-based. The setting time influenced the epoxy resin-based sealer cytotoxicity (decreased at 12 hours) and the general genotoxicity (increased at 24 hours). DNA damage ranking was the following (from the most to the least genotoxic): methacrylate-based > silicone-based = epoxy resin-based. Conclusions: The setting time had influence on the cytotoxicity of the epoxy resin-based sealer and genotoxicity of all tested sealers. The methacrylate-based sealer was the most cytotoxic, and the silicone-based sealer was not cytotoxic. Genotoxicity was observed for all sealers. © 2013 American Association of Endodontists.

Use of cone-beam tomography and digital subtraction radiography for diagnosis and evaluation of traumatized teeth treated with endodontic surgery and MTA. A case report

The aim of this paper was to report the diagnosis and evaluation of periradicular bone repair by using computed tomography and digital subtraction radiography in an endodontic surgery case treated with mineral trioxide aggregate (MTA). The patient had local swelling and fistula 7years after trauma in the upper jaw. Periapical lesion on tooth #12 and root resorption of tooth #11 were detected radiographically. Endodontic therapy and placement of intracanal medication were carried out. After 3months, with no improvement in the clinical signs and symptoms, computed tomography was performed, showing extensive apical bone resorption on tooth #12 and dental resorption promoting communication of the root canal with the periodontium of tooth #11. The patient was referred to endodontic surgery. After surgery and postoperative periods of 15, 30, 60, 90, and 120days, standardized radiographs were taken, digitized, and subjected to digital subtraction of the images using Adobe Photoshop CS software. Four years later, a cone-beam computed tomography was performed, showing bone repair and absence of root resorption at tooth #11. In this clinical case, digital subtraction radiography was effective for early detection of new bone formation and evolution of repair. © 2011 John Wiley & Sons A/S.

Ultra-estrutura de células presentes no reparo tecidual sob atividade física moderada

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação histopatológica e imuno-histoquímica do miocárdio de cães com leishmaniose visceral: Fernando Azadinho Rosa. -

Pós-graduação em Ciência Animal - FMVA

Estudo radiográfico da espessura do esmalte nas faces proximais de dentes anteriores e posteriores

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Reimplante dentário após obturação do canal com pasta de hidróxido de cálcio associado ao plug apical de MTA: estudo histomorfométrico em ratos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Detecção e ação antimicrobiana e antiendotóxica do extrato glicólico de gengibre utilizado como substância química auxiliar durante o retratamento endodôntico

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação in vitro da citotoxicidade e genotoxicidade de diferentes cimentos endodônticos em fibroblastos V79

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Análise radiográfica da modelagem de canais radiculares ovalados realizada com sistemas rotatórios de níquel-titânio

Pós-graduação em Odontologia - FOAR

Material obturador de canal radicular à base de uretano metacrilato: estudo histológico e da infiltração coronária em dentes de cães

Pós-graduação em Odontologia - FOAR

Efeito de soluções irrigadoras e do hidróxido de cálcio como curativo de demora sobre o LPS-endotoxina. Estudo histopatológico em dentes de cães

Pós-graduação em Odontologia - FOAR