Microtomographic, histomorphometric, and molecular features show a normal alveolar bone healing process in iNOS-deficient mice along a compensatory upregulation of eNOS and nNOS isoforms

Abstract Inducible nitric oxide synthase (iNOS) is one of the enzymes responsible for the synthesis of nitric oxide (NO), which is an important signaling molecule with effects on blood vessels, leukocytes, and bone cells. However, the role of iNOS in alveolar bone healing remains unclear. This study investigated the role of iNOS in alveolar bone healing after tooth extraction in mice. Methodology C57Bl/6 wild type (WT) and iNOS genetically deficient (iNOS-KO) mice were subjected to upper incision tooth extraction, and alveolar bone healing was evaluated by micro-computed tomography (μCT) and histological/histomorphometric, birefringence, and molecular methods. Results The expression of iNOS had very low control conditions, whereas a significant increase is observed in healing sites of WT mice, where iNOS mRNA levels peak at 7d time point, followed by a relative decrease at 14d and 21d. Regarding bone healing, both WT and iNOS-KO groups showed the usual phases characterized by the presence of clots, granulation tissue development along the inflammatory cell infiltration, angiogenesis, proliferation of fibroblasts and extracellular matrix synthesis, bone neoformation, and remodeling. The overall micro-computed tomography and histomorphometric and birefringence analyses showed similar bone healing readouts when WT and iNOS-KO strains are compared. Likewise, Real-Time PCR array analysis shows an overall similar gene expression pattern (including bone formation, bone resorption, and inflammatory and immunological markers) in healing sites of WT and iNOS-KO mice. Moreover, molecular analysis shows that nNOS and eNOS were significantly upregulated in the iNOS-KO group, suggesting that other NOS isoforms could compensate the absence of iNOS. Conclusion The absence of iNOS does not result in a significant modulation of bone healing readouts in iNOS-KO mice. The upregulation of nNOS and eNOS may compensate iNOS absence, explaining the similar bone healing outcome in WT and iNOS-KO strains.

Clinical and Molecular Disorders Caused by COVID-19 During Pregnancy as a Potential Risk for Enamel Defects

ABSTRACT This paper discusses the potential risk that COVID-19 generates for the development of enamel defects. This hypothesis was built based on the etiopathogenesis of enamel defects and the relationship with the symptom's characteristic of COVID-19. Pregnancy is a critical period for the child's development; exposure to pathological agents can cause systemic imbalances and risks of adverse perinatal and prenatal outcomes. The main clinical symptoms of this disease and its association with that dental outcome were considered. Fever, breathing, cardiovascular disorders, and diarrhea were related as potential etiological factors of ameloblast metabolism imbalance, which can interfere qualitatively and quantitatively in the development, maturation and mineralization of the tooth enamel. Molecular disorders derived from COVID-19, as well as their clinical symptoms, can be considered potential risk factors for the development of enamel defects. Individuals with enamel defects experienced high stress levels during pregnancy or early childhood. The approach adopted may help build new research to ensure understanding of the etiology of the development of dental enamel defects and its relationship with COVID-19. However, longitudinal studies need to be conducted to confirm the association between COVID-19 and adverse events during pregnancy.

CCR2 Contributes to F4/80+ Cells Migration Along Intramembranous Bone Healing in Maxilla, but Its Deficiency Does Not Critically Affect the Healing Outcome.

Bone healing depends of a transient inflammatory response, involving selective migration of leukocytes under the control of chemokine system. CCR2 has been regarded as an essential receptor for macrophage recruitment to inflammation and healing sites, but its role in the intramembranous bone healing on craniofacial region remains unknown. Therefore, we investigated the role of CCR2 on F4/80+ cells migration and its consequences to the intramembranous healing outcome. C57BL/6 wild-type (WT) and CCR2KO mice were subjected to upper right incisor extraction, followed by micro-computed tomography, histological, immunological, and molecular analysis along experimental periods. CCR2 was associated with F4/80+ cells influx to the intramembranous bone healing in WT mice, and CCR2+ cells presented a kinetics similar to F4/80+ and CCR5+ cells. By contrast, F4/80+ and CCR5+ cells were significantly reduced in CCR2KO mice. The absence of CCR2 did not cause major microscopic changes in healing parameters, while molecular analysis demonstrated differential genes expression of several molecules between CCR2KO and WT mice. The mRNA expression of TGFB1, RUNX2, and mesenchymal stem cells markers (CXCL12, CD106, OCT4, NANOG, and CD146) was decreased in CCR2KO mice, while IL6, CXCR1, RANKL, and ECM markers (MMP1, 2, 9, and Col1a2) were significantly increased in different periods. Finally, immunofluorescence and FACS revealed that F4/80+ cells are positive for both CCR2 and CCR5, suggesting that CCR5 may account for the remaining migration of the F4/80+ cells in CCR2KO mice. In summary, these results indicate that CCR2+ cells play a primary role in F4/80+ cells migration along healing in intramembranous bones, but its deficiency does not critically impact healing outcome.

Oral implant osseointegration model in C57Bl/6 mice: microtomographic, histological, histomorphometric and molecular characterization.

INTRODUCTION: Despite the successful clinical application of titanium (Ti) as a biomaterial, the exact cellular and molecular mechanisms responsible for Ti osseointegration remains unclear, especially because of the limited methodological tools available in this field. OBJECTIVE: In this study, we present a microscopic and molecular characterization of an oral implant osseointegration model using C57Bl/6 mice. MATERIAL AND METHODS: Forty-eight male wild-type mice received a Ti implant on the edentulous alveolar crest and the peri-implant sites were evaluated through microscopic (µCT, histological and birefringence) and molecular (RealTimePCRarray) analysis in different points in time after surgery (3, 7, 14 and 21 days). RESULTS: The early stages of osseointegration were marked by an increased expression of growth factors and MSC markers. Subsequently, a provisional granulation tissue was formed, with high expression of VEGFb and earlier osteogenic markers (BMPs, ALP and Runx2). The immune/inflammatory phase was evidenced by an increased density of inflammatory cells, and high expression of cytokines (TNF, IL6, IL1) chemokines (CXCL3, CCL2, CCL5 and CXC3CL1) and chemokine receptors (CCR2 and CCR5). Also, iNOS expression remained low, while ARG1 was upregulated, indicating predominance of a M2-type response. At later points in time, the bone matrix density and volume were increased, in agreement with a high expression of Col1a1 and Col21a2. The remodelling process was marked by peaks of MMPs, RANKL and OPG expression at 14 days, and an increased density of osteoclasts. At 21 days, intimate Ti/bone contact was observed, with expression of final osteoblast differentiation markers (PHEX, SOST), as well as red spectrum collagen fibers. CONCLUSIONS: This study demonstrated a unique molecular view of oral osseointegration kinetics in C57Bl/6 mice, evidencing potential elements responsible for orchestrating cell migration, proliferation, ECM deposition and maturation, angiogenesis, bone formation and remodeling at the bone-implant interface in parallel with a novel microscopic analysis.

Oral implant osseointegration model in C57Bl/6 mice: microtomographic, histological, histomorphometric and molecular characterization

Abstract Despite the successful clinical application of titanium (Ti) as a biomaterial, the exact cellular and molecular mechanisms responsible for Ti osseointegration remains unclear, especially because of the limited methodological tools available in this field. Objective: In this study, we present a microscopic and molecular characterization of an oral implant osseointegration model using C57Bl/6 mice. Material and Methods: Forty-eight male wild-type mice received a Ti implant on the edentulous alveolar crest and the peri-implant sites were evaluated through microscopic (μCT, histological and birefringence) and molecular (RealTimePCRarray) analysis in different points in time after surgery (3, 7, 14 and 21 days). Results: The early stages of osseointegration were marked by an increased expression of growth factors and MSC markers. Subsequently, a provisional granulation tissue was formed, with high expression of VEGFb and earlier osteogenic markers (BMPs, ALP and Runx2). The immune/inflammatory phase was evidenced by an increased density of inflammatory cells, and high expression of cytokines (TNF, IL6, IL1) chemokines (CXCL3, CCL2, CCL5 and CXC3CL1) and chemokine receptors (CCR2 and CCR5). Also, iNOS expression remained low, while ARG1 was upregulated, indicating predominance of a M2-type response. At later points in time, the bone matrix density and volume were increased, in agreement with a high expression of Col1a1 and Col21a2. The remodelling process was marked by peaks of MMPs, RANKL and OPG expression at 14 days, and an increased density of osteoclasts. At 21 days, intimate Ti/bone contact was observed, with expression of final osteoblast differentiation markers (PHEX, SOST), as well as red spectrum collagen fibers. Conclusions: This study demonstrated a unique molecular view of oral osseointegration kinetics in C57Bl/6 mice, evidencing potential elements responsible for orchestrating cell migration, proliferation, ECM deposition and maturation, angiogenesis, bone formation and remodeling at the bone-implant interface in parallel with a novel microscopic analysis.

Expression of heat shock proteins in periapical granulomas.

INTRODUCTION: Cells from virtually all organisms respond to a variety of stresses by the rapid synthesis of a highly conserved set of polypeptides termed heat shock proteins (HSPs). HSPs protect cells under adverse conditions such as infection, inflammation, and disease. We hypothesize that endodontic infection might result in an imbalance in the expression of heat shock genes, accounting for different clinical outcomes in periapical lesions. METHODS: We analyzed the expression of 44 HSPs genes using a pathway-specific real-time polymerase chain reaction array in 93 human periapical granulomas and 24 healthy periodontal ligament tissues collected postoperatively. Observed variations in the expression of HSP genes were also analyzed based on the classification of periapical granulomas as active or inactive. In addition, U937 cells were differentiated into macrophages, infected with different concentrations of purified Escherichia coli lipopolysaccharide (LPS), and used as templates for the HSP gene array. Protein expression was assessed by immunohistochemistry. RESULTS: The expression of HSP genes was significantly increased in granulomas compared with healthy periodontal ligament (P < .00001). Among the 44 HSP genes, DNAJC3, HSPA4, HSPA6, and HSPB1 showed the highest expression levels in both granulomas and LPS-treated macrophages. DNAJC3, HSPA6, and HSPB1 were highly expressed in active lesions, whereas HSPA4 expression was higher in inactive lesions (P < .005). Higher concentrations of LPS led to increased HSP expression in macrophages (P < .0001). Immunocytochemistry confirmed the expression and colocalization of HSPB1 and HSPA6 proteins in the cytoplasm of LPS-infected macrophages. CONCLUSIONS: The observed differential expression patterns of HSPs in periapical granulomas and LPS-infected macrophages suggest that HSP genes and proteins are involved in periapical lesion development and may account for different clinical outcomes. Understanding the role of the heat shock response might provide additional insights into the process of periapical lesion development.

Levels of immunoglobulin A1 in peri-implant fluid and saliva from patients with mucositis: a preliminary study.

There are no studies evaluating the possible use of immunoglobulin A1 (IgA1) as an early marker for peri-implant inflammation. The aim of this study was to evaluate the IgA1 levels in peri-implant sulcular fluid (PISF) and saliva of partially edentulous patients as an indicator of mucositis. Twenty-seven patients were examined to determine the peri-implant status based on probing depth and bleeding on probing. Saliva and PISF around dental implants were collected and the IgA1 levels were evaluated by Elisa assay. IgA1 in saliva and PISF of these patients were compared and their correlations with clinical parameters were evaluated. Differences in IgA1 levels in saliva (821.1 ± 290.6; 779.8 ± 401.5) and PISF (26.6 ± 20.7; 25.1 ± 20.5) of healthy and mucositis groups, respectively were not observed (p>0.05). Correlation between clinical parameters and IgA1 in saliva or PISF was not observed in healthy or mucositis groups (p=0.607; p=0.826, respectively). These results suggest that IgA1 cannot be used as an immunological marker of mucositis.

Levels of Immunoglobulin A1 in Peri-Implant Fluid and Saliva from Patients with Mucositis: A Preliminary Study

There are no studies evaluating the possible use of immunoglobulin A1 (IgA1) as an early marker for peri-implant inflammation. The aim of this study was to evaluate the IgA1 levels in peri-implant sulcular fluid (PISF) and saliva of partially edentulous patients as an indicator of mucositis. Twenty-seven patients were examined to determine the peri-implant status based on probing depth and bleeding on probing. Saliva and PISF around dental implants were collected and the IgA1 levels were evaluated by Elisa assay. IgA1 in saliva and PISF of these patients were compared and their correlations with clinical parameters were evaluated. Differences in IgA1 levels in saliva (821.1 ± 290.6; 779.8 ± 401.5) and PISF (26.6 ± 20.7; 25.1 ± 20.5) of healthy and mucositis groups, respectively were not observed (p>0.05). Correlation between clinical parameters and IgA1 in saliva or PISF was not observed in healthy or mucositis groups (p=0.607; p=0.826, respectively). These results suggest that IgA1 cannot be used as an immunological marker of mucositis.

Não existem estudos que avaliem a utilização de imunoglobulina A1 (IgA1) como marcador precoce da inflamação peri-implantar. O objetivo deste estudo foi avaliar os níveis de IgA1 do fluido sulcular peri-implantar (PISF) e saliva de pacientes parcialmente desdentados como indicador da mucosite. Vinte e sete pacientes foram examinados para determinar a condição peri-implantar com base na profundidade de sondagem e sangramento à sondagem. Saliva e PISF ao redor de implantes dentários foram coletados e os níveis IgA1 foram avaliados pelo teste Elisa. IgA1 na saliva e PISF destes pacientes foram comparados e suas correlações com parâmetros clínicos foram avaliados. Não foram observadas diferenças nos níveis de IgA1 (821,1 ± 290,6; 779,8 ± 401,5) na saliva e PISF (26,6 ± 20,7; 25,1 ± 20,5) de grupos saudáveis e mucosite, respectivamente (p>0,05). Correlação entre os parâmetros clínicos e IgA1 na saliva ou PISF não foi observada em grupos saudáveis ou mucosite (p=0,607; p=0,826, respectivamente). Estes resultados demonstraram que IgA1 não pode ser utilizada como marcador imunológico da mucosite.

Would nitric oxide be an effective marker for earlier stages of peri-implant disease? An analysis in human peri-implant sulcular fluid.

Nitric oxide has an important effect on host immune response. However, little has been studied in relation to its potential as a possible diagnostic tool in peri-implant disease. The present study analyzed nitrite levels in the peri-implant sulcular fluid (PISF) of implants with mucositis and the correlation of these nitrite levels with clinical parameters using a simplified fluid collection methodology. Twenty-five partially edentulous patients showing peri-implant mucositis were evaluated, and the peri-implant status was determined based on current clinical parameters: probing depth (PD) and bleeding on probing (BOP). The sulcular fluid (SF) around teeth (control) and implants were collected, and the nitrite levels were evaluated using the Griess method. The mean probing depth (mm) was significantly higher (P < .0001) in implants (2.852 ± 0.6484) than in control teeth (1.585 ± 0.3636). The mean total nitrite level (µM) was statistically higher (P = .0069) in implants with mucositis (14.34 ± 11.83) than in control teeth (9.316 ± 5.534). No correlation was observed between the total nitrite levels and the PD mean in the control group (P = .2558, r = -0.2361) or in the implant group (P = .1160, r = -0.3224), as well as the number of faces showing bleeding on probing (P = .8747, r = 0.0332). These results demonstrated that the nitrite levels were higher in inflamed areas. According to the methodology applied and results obtained, the higher nitrite levels in inflamed areas suggest that, in the future, nitrite could be used as a marker of peri-implant mucositis associated with clinical data to monitor the cure or evolution of the disease.

Evidence supporting a protective role for th9 and th22 cytokines in human and experimental periapical lesions.

INTRODUCTION: The development of periapical granulomas is dependent on the host response and involves Th1, Th2, Th17, and Treg-related cytokines. The discovery of new Th9 and Th22 subsets, with important immunomodulatory roles mediated by interleukin (IL)-9 and IL-22, respectively, emphasizes the need for reevaluation of current cytokine paradigms in context of periapical lesions. We investigated the expression of IL-9 and IL-22 in active and stable human granulomas and throughout experimental lesion development in mice. METHODS: Periapical granulomas (N = 83) and control specimens (N = 24) were evaluated regarding the expression of IL-9 and IL-22 via real-time polymerase chain reaction. Experimental periapical lesions were induced in mice (pulp exposure and bacterial inoculation) and the lesions evolution correlation with IL-9 and IL-22 expression kinetics was evaluated. RESULTS: IL-9 and IL-22 mRNA expression was higher in periapical lesions than in control samples; higher levels of IL-9 and IL-22 were observed in inactive than in active lesions. In the experimental lesions model, increasing levels of IL-9 and IL-22 mRNA were detected in the lesions, and inverse correlations were found between IL-9 and IL-22 and the increase of lesion area in the different time point intervals. CONCLUSIONS: Our results suggest that Th9 and Th22 pathways may contribute to human and experimental periapical lesion stability.

Caracterização morfométrica e molecular do papel de citocinas pró e anti-inflamatórias no processo de reparo ósseo alveolar em condições homeostáticas e infecciosas / Morphometric and molecular characterization of the role of pro- and anti-inflammatory cytokines in alveolar bone repair process under homeostatic and infectious conditions

O metabolismo ósseo é influenciado por fatores endócrinos, genéticos, de crescimento, sistema RANK/RANKL/OPG, além de uma variedade de moléculas regulatórias, como as citocinas. Citocinas têm sido implicadas na patogênese de doenças ósseas, no entanto, ainda pouco se sabe sobre os mecanismos envolvidos na interação entre o sistema ósseo e imunológico no processo de reparo ósseo. O objetivo deste estudo foi caracterizar o papel de TNF-α e IL-10 no reparo ósseo alveolar em condições homeostáticas (controle [C]) e infecciosas (alveolite experimental [A]) pós exodontia em camundongos C57Bl/6 (WT), TNFp55KO e IL-10KO. Após a cirurgia nos grupos infectados foi induzida a alveolite por meio de isquemia do alvéolo e uma suspensão de secreção purulenta. As maxilas foram coletadas em 0h, 7, 14 e 21 dias após a extração do incisivo superior para análises histológica, histomorfométrica e molecular (RealTimePCR). Na análise histomorfométrica foram quantificados os parâmetros coágulo, células inflamatórias, fibras, fibroblastos, vasos sanguíneos, matriz óssea, osteoblastos, osteoclastos, e outros espaço do líquido intersticial e medula óssea. Na análise molecular (RealTimePCR) foram quantificados a expressão de fatores de crescimento, marcadores ósseos e de matriz extracelular, citocinas e quimiocinas envolvidos no processo. Os dados obtidos foram submetidos ao teste OneWay ANOVA seguido do teste de comparação múltipla de Tukey. Os resultados demonstraram que nos camundongos WT-C houve a formação inicial de coágulo (0 hora) com início da expressão de BMP2, BMP4, BMP7, TGFb1 and VEGFa que tiveram aumento gradativo com pico em 7 dias. A expressão de TNF-α e IL10 também tiveram seus picos aos 7 dias em paralelo com contagem de leucócitos, associado com a expressão de CCL2, CCL5 e CXCL1. Nos períodos seguintes houve uma diminuição inflamatória e o aumento de marcadores osteoblásticos/osteogênicos. A indução da alveolite experimental em WT-A resultou no aumento marcante...

Bone metabolism is influenced by endocrine, genetic and growth factors, RANK/RANKL/OPG system, besides a variety of regulatory molecules, such as cytokines. Cytokines have been implicated in pathogenesis of bone diseases, however, little is known about the mechanisms involved in the interaction between skeletal and immune system in the bone repair process. The objective of this study was characterized the role of TNF-α and IL-10 in alveolar bone repair under homeostatic (control [C]) and infectious (experimental alveolitis [A]) conditions in C57Bl/6 (WT), TNFp55KO and IL-10KO mice. After surgery, in infectious groups was induced by ischemia alveolitis the well and a suspension of pus. The maxillas were collected at 0h, 7, 14 and 21 days after extraction of the maxillary incisor for histologic, histomorphometric and molecular (RealTimePCR). In histomorphometric analysis parameters were measured clot, inflammatory cells, fibers, fibroblasts, blood vessels, bone matrix, osteoblast, osteoclast, and other space - the interstitial fluid and bone mar row. Molecular analysis (RealTimePCR) were quantified the expression of growth factors, bone markers and extracellular matrix, cytokines and chemokines involved in the process. The data were submitted to the OneWay ANOVA test followed by Tukey's multiple comparison test. The results showed that in WT-C initial clot formation (0 hours) with early expression of BMP2, BMP4, BMP7, and TGFb1 VEGFa who had gradual increase peaking in 7 days. The expression of TNF-α and IL10 also peaked at 7 days in parallel with leukocyte count, associated with CCL2, CCL5 and CXCL1. In late periods there were decrease of inflammation and markers osteoblastic / osteogenic increased. Induction of experimental alveolitis in WT resulted in a marked increase in expression of TNF-α accompanied by increased expression of CXCL1 and CCL5, increased leukocyte count and decreased of IL10 expression that peaked at 14d, besides prominent...

Caracterização morfométrica e molecular do papel de citocinas pró e anti-inflamatórias no processo de reparo ósseo alveolar em condições homeostáticas e infecciosas / Morphometric and molecular characterization of the role of pro- and anti-inflammatory cytokines in alveolar bone repair process under homeostatic and infectious conditions

O metabolismo ósseo é influenciado por fatores endócrinos, genéticos, de crescimento, sistema RANK/RANKL/OPG, além de uma variedade de moléculas regulatórias, como as citocinas. Citocinas têm sido implicadas na patogênese de doenças ósseas, no entanto, ainda pouco se sabe sobre os mecanismos envolvidos na interação entre o sistema ósseo e imunológico no processo de reparo ósseo. O objetivo deste estudo foi caracterizar o papel de TNF-α e IL-10 no reparo ósseo alveolar em condições homeostáticas (controle [C]) e infecciosas (alveolite experimental [A]) pós exodontia em camundongos C57Bl/6 (WT), TNFp55KO e IL-10KO. Após a cirurgia nos grupos infectados foi induzida a alveolite por meio de isquemia do alvéolo e uma suspensão de secreção purulenta. As maxilas foram coletadas em 0h, 7, 14 e 21 dias após a extração do incisivo superior para análises histológica, histomorfométrica e molecular (RealTimePCR). Na análise histomorfométrica foram quantificados os parâmetros coágulo, células inflamatórias, fibras, fibroblastos, vasos sanguíneos, matriz óssea, osteoblastos, osteoclastos, e outros espaço do líquido intersticial e medula óssea. Na análise molecular (RealTimePCR) foram quantificados a expressão de fatores de crescimento, marcadores ósseos e de matriz extracelular, citocinas e quimiocinas envolvidos no processo. Os dados obtidos foram submetidos ao teste OneWay ANOVA seguido do teste de comparação múltipla de Tukey. Os resultados demonstraram que nos camundongos WT-C houve a formação inicial de coágulo (0 hora) com início da expressão de BMP2, BMP4, BMP7, TGFb1 and VEGFa que tiveram aumento gradativo com pico em 7 dias. A expressão de TNF-α e IL10 também tiveram seus picos aos 7 dias em paralelo com contagem de leucócitos, associado com a expressão de CCL2, CCL5 e CXCL1. Nos períodos seguintes houve uma diminuição inflamatória e o aumento de marcadores osteoblásticos/osteogênicos. A indução da alveolite experimental em WT-A resultou no aumento marcante...

Bone metabolism is influenced by endocrine, genetic and growth factors, RANK/RANKL/OPG system, besides a variety of regulatory molecules, such as cytokines. Cytokines have been implicated in pathogenesis of bone diseases, however, little is known about the mechanisms involved in the interaction between skeletal and immune system in the bone repair process. The objective of this study was characterized the role of TNF-α and IL-10 in alveolar bone repair under homeostatic (control [C]) and infectious (experimental alveolitis [A]) conditions in C57Bl/6 (WT), TNFp55KO and IL-10KO mice. After surgery, in infectious groups was induced by ischemia alveolitis the well and a suspension of pus. The maxillas were collected at 0h, 7, 14 and 21 days after extraction of the maxillary incisor for histologic, histomorphometric and molecular (RealTimePCR). In histomorphometric analysis parameters were measured clot, inflammatory cells, fibers, fibroblasts, blood vessels, bone matrix, osteoblast, osteoclast, and other space - the interstitial fluid and bone mar row. Molecular analysis (RealTimePCR) were quantified the expression of growth factors, bone markers and extracellular matrix, cytokines and chemokines involved in the process. The data were submitted to the OneWay ANOVA test followed by Tukey's multiple comparison test. The results showed that in WT-C initial clot formation (0 hours) with early expression of BMP2, BMP4, BMP7, and TGFb1 VEGFa who had gradual increase peaking in 7 days. The expression of TNF-α and IL10 also peaked at 7 days in parallel with leukocyte count, associated with CCL2, CCL5 and CXCL1. In late periods there were decrease of inflammation and markers osteoblastic / osteogenic increased. Induction of experimental alveolitis in WT resulted in a marked increase in expression of TNF-α accompanied by increased expression of CXCL1 and CCL5, increased leukocyte count and decreased of IL10 expression that peaked at 14d, besides prominent...

The use of chronic gingivitis as reference status increases the power and odds of periodontitis genetic studies: a proposal based in the exposure concept and clearer resistance and susceptibility phenotypes definition.

AIM: Current literature on chronic periodontitis genetics encompasses numerous single nucleotide polymorphisms-focused case-control studies with inconsistent and controversial results, which typically disregards the exposure concept embraced by case-control definition. Herein, we propose a case-control design reappraisal by clear phenotype selection, where chronic gingivitis represents a genetically resistant phenotype/genotype opposing the susceptible cohort. MATERIAL AND METHODS: The hypothesis was tested in healthy, chronic periodontitis and gingivitis groups through Real-time PCR-based allelic discrimination of classic variants IL1B-3954, IL6-174, TNFA-308, IL10-592 and TLR4-299. RESULTS: Observed allele/genotype frequencies characterize the healthy group with an intermediate genetic profile between periodontitis and gingivitis cohorts. When comparing genotype/allele frequencies in periodontitis versus healthy and periodontitis versus gingivitis scenarios, the number of positive associations (2-4) and the degree of association (p and odds ratio values) were significantly increased by the new approach proposed (periodontitis versus gingivitis), suggesting the association of IL1B-3954, TNFA-308, IL10-592 and TLR4-299 with periodontitis risk. Power study was also significantly improved by the new study design proposed when compared to the traditional approach. CONCLUSIONS: The data presented herein support the use of new case-control study design based on the case-control definition and clear resistance/susceptibility phenotypes selection, which can significantly impact the study power and odds of identification of genetic factors involved in PD.

Pulpite crônica hiperplásica: análise histológica ao microscópio de luz e microscópio eletrônico de transmissão / Chronic hyperplastic pulpitis: histological analysis in light microscope and transmission electron microscope

Este estudo analisou as características morfológicas de pólipos pulpares de adultos jovens ao microscópio de luz (ML) e ao microscópio eletrônico de transmissão (MET). Foram analisados 5 pólipos de primeiros molares, que foram removidos e fixados em glutaraldeído 2,5%. Após a fixação, cada pólipo foi dividido em duas metades, uma foi processada para inclusão em glicol metacrilato e a outra para inclusão em resina epóxica. Os cortes histológicos com 3 μm de espessura foram corados em azul de toluidina e analisados ao ML e os cortes com 80 nm foram contrastados em citrato de chumbo e acetato de uranila e analisados ao MET. Ao ML foi observado epitélio espesso não queratinizado com alguns mastócitos na camada basal. O conjuntivo apresentou infiltrado inflamatório crônico, com ninhos de plasmócitos e vasos neoformados. A análise ao MET mostrou células epiteliais da camada basal com núcleo ovóide, citoplasma com muitos ribossomas livres, mitocôndrias e poucos feixes de tonofilamentos. A lâmina basal apresentou-se nítida com muitos hemidesmossomas. Na camada espinhosa observou-se células grandes, núcleos com cromatina descondensada e nucléolos evidentes. No citoplasma foi observado muitos feixes de tonofilamentos, muitas mitocôndrias, ribossomas livres e muitos desmossomas. No conjuntivo observou-se macrófagos, mastócitos e plasmócitos na região adjacente ao epitélio. Nas regiões mais profundas predominavam fibroblastos entres feixes de fibrilas colágenas, vasos sangüíneos com células endoteliais proeminentes e pericitos associados. Os resultados confirmaram que o epitélio do pólipo pulpar apresenta características morfológicas semelhantes ao da mucosa oral humana. O conjuntivo mostrou características de inflamação crônica de intensidade variada.

Distribution of glycogen storage during odontogenesis in fetal development in Calomys callosus

As células animais estocam carboidratos na forma de glicogênio como fonte de energia. Esses depósitos ocorrem amplamente nos tecidos embrionßrios para disponibilização rßpida de energia, principalmente durante a diferenciação e o desenvolvimento das células. O presente trabalho avaliou a distribuição de depósitos de glicogênio durante a odontogênese intra-uterina em Calomys callosus utilizando fetos com 12 a 20 dias, sendo 5 fetos de cada dia. As cabeças dos fetos foram removidas e fixadas em formaldeído 10% em PBS. Os espécimes foram processados para inclusão em glicol metacrilato (Leica Historesin), sendo aqueles com mais de 15 dias previamente descalcificados em EDTA. Para cada dia de desenvolvimento obteve-se cortes semi-seriados com 3 µm de espessura. As lâminas foram divididas em 2 grupos, sendo um grupo submetido à reação P.A.S. e o outro submetido à amilase salivar e em seguida à reação P.A.S. (grupo controle). Ao microscópio de luz foi observada, nas fases iniciais da odontogênese (12-15 dias), reação P.A.S. mais evidente nas células ectomesenquimais e aos 16-17 dias a reação predominou na região do folículo dental. Aos 18-19 dias a reação intensificou-se no retículo estrelado e aos 20 dias nas células do epitélio interno e na papila dental. De acordo com a metodologia empregada e com os resultados obtidos, concluímos que ocorre variação dos depósitos de glicogênio nas diferentes regiões do germe dental ao longo da odontogênese e que o Calomys callosus representa um modelo biológico para estudos da odontogênese.