Ana Paula Morais Fernandes

The Role of Toll-Like Receptor 2 in the Recognition of Aggregatibacter actinomycetemcomitans

BACKGROUND Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans) is a Gram-negative bacterium present in the oral cavity and is usually associated with localized aggressive periodontitis. Isolated antigens from A. actinomycetemcomitans can activate innate immune cells through Toll-like receptors (TLRs), which are molecules that recognize structural components conserved among microorganisms. In this study, we evaluate the role of TLR2 in the recognition of A. actinomycetemcomitans. METHODS Macrophages and neutrophils from knockout mice with targeted disruption of TLR2 (TLR2(-/-) mice) and wild-type mice were collected and used for the subsequent assays. The production of cytokines and chemokines was evaluated by enzyme-linked immunosorbent assay (ELISA), and the presence of apoptotic cells was determined by flow cytometry. In addition, the mechanisms that modulate the outcome of A. actinomycetemcomitans-induced periodontal disease in TLR2(-/-) mice were examined. RESULTS The results show that TLR2-deficient mice developed more severe periodontitis after A. actinomycetemcomitans infection, characterized by significantly higher bone loss and inflammatory cell migration to periodontal tissues. The inflammatory cell influx into the peritoneal cavities of TLR2(-/-) mice was three-fold lower than that observed for the littermate controls. A significantly diminished production of the cytokines tumor necrosis factor-alpha and interleukin-1beta as well as the chemokine CC-ligand-5 in the peritoneal cavities of TLR2(-/-) mice was observed. In addition, a high frequency of apoptotic cells in the inflammatory exudates from TLR2(-/-) mice was observed. Phagocytosis and nitric oxide production was diminished in cells from TLR2(-/-) mice, facilitating the dissemination of the pathogen to the spleen. CONCLUSION The results of this study highlight the involvement of TLR2 in recognizing A. actinomycetemcomitans and its essential role in controlling A. actinomycetemcomitans infection.

The essential role of toll like receptor-4 in the control of Aggregatibacter actinomycetemcomitans infection in mice

OBJECTIVE Aggregatibacter actinomycetemcomitans is an oral Gram-negative bacterium that contributes to periodontitis progression. Isolated antigens from A. actinomycetemcomitans could be activating innate immune cells through Toll-like receptors (TLRs). In this study, we evaluated the role of TLR4 in the control of A. actinomycetemcomitans infection. MATERIAL AND METHODS We examined the mechanisms that modulate the outcome of A. actinomycetemcomitans-induced periodontal disease in TLR4(-/-) mice. The production of cytokines was evaluated by ELISA. The bacterial load was determined by counting the number of colony-forming units per gram of tissue. RESULTS The results showed that TLR4-deficient mice developed less severe periodontitis after A. actinomycetemcomitans infection, characterized by significantly lower bone loss and inflammatory cell migration to periodontal tissues. However, the absence of TLR4 facilitated the A. actinomycetemcomitans dissemination. Myeloperoxidase activity was diminished in the periodontal tissue of TLR4(-/-) mice. We observed a significant reduction in the production of tumour necrosis factor-alpha (TNF-alpha) and interleukin (IL)-1beta in the periodontal tissue of TLR4(-/-) mice. CONCLUSION The results of this study highlighted the role of TLR4 in controlling A. actinomycetemcomitans infection.

HLA-DRB1, DQB1, and DQA1 allele profile in Brazilian patients with type 1 diabetes mellitus.

Abstract: HLA class II profile was evaluated in 64 Brazilian patients presenting with type 1 diabetes mellitus. Although the Brazilian population is highly miscegenated, HLA‐DRB1*301, DRB1*04, DQB1*0302, and DQB1*0201 alleles, which are associated with the development of type 1 diabetes in several Western populations, were also overrepresented in Brazilian patients. In addition to HLA‐DRB1*15 and DQB1*0602 alleles, DRB1*11, DRB1*13, and DQA1*01 allele groups were associated with protection against the development of type 1 diabetes in Brazilian patients.

Interleukin-18 and interferon-gamma polymorphisms in Brazilian human immunodeficiency virus-1-infected patients presenting with lipodystrophy syndrome

Cytokines play important roles in the pathogenesis of lipodystrophy syndrome (LS). Single nucleotide polymorphisms (SNPs) at positions -607(C/A) and -137(C/G) in the promoter region of the interleukin-18 (IL-18) gene and at position +874(T/A) of the interferon-gamma (IFN-gamma) gene are related to the expression of these cytokines. To examine whether IL-18 and IFN-gamma polymorphisms are associated with LS, these SNPs were genotyped in 88 human immunodeficiency virus (HIV)-infected patients presenting LS, 79 HIV-infected without LS, and 133 healthy controls. The -607A allele, -607AA genotype, and -137G/-607A and -137C/-607A haplotypes in the IL-18 gene were over-represented in HIV patients presenting LS. The -137G/-607C haplotype was associated with protection against LS. These results indicate that the -607(C/A) SNP is associated with LS development in HIV-infected patients.

Clinical and radiographic outcomes of the use of Low-Level Laser Therapy in vital pulp of primary teeth.

AIM This study aimed to compare the clinical and radiographic effectiveness of Low Level Laser Therapy in vital pulp of human primary teeth. METHODS Sixty mandibular primary molars of children aged between 5-9 years were assigned into four groups: Diluted Formocresol (FC), Calcium Hydroxide (CH), Low Level Laser Therapy (LLLT) and Calcium Hydroxide preceded by Low Level Laser Therapy (LLLT + CH). The clinical and radiographic evaluations were performed at 6, 12 and 18 post-operative months. RESULTS All the groups studied were successful in the clinical evaluation over the follow-up period. At 6 months, the radiographic success rate for FC group was 100%, 60% for CH group, 80% for LLLT group and 85.7% for LLLT + CH group. After 12 months, the radiographic success rate was 100% for FC group, 50% for CH group, 80% for LLLT group and 78.6% for LLLT + CH group. At the 18 months follow-up, 100% of the FC group, 66.7% of CH group, 73.3% of the LLLT group and 75% of the LLLT + CH group. CONCLUSION These findings suggest that Low Level Laser Therapy may be considered as an adjuvant alternative for vital pulp therapy on human primary teeth. Low Level Laser Therapy preceding the use of calcium hydroxide showed satisfactory results.

Lipodystrophy syndrome associated with antiretroviral therapy in HIV patients: considerations for psychosocial aspects

Several side effects have been strongly associated with antiretroviral therapy in HIV patients. Among them, the lipodystrophy syndrome which presents alterations in body shape with central adipose hypertrophy and peripheral lipoatrophy, reported by patients as a visible marker identifying them as HIV patients. This manuscript presents an analysis of current literature regarding the psychosocial aspects of HIV patients with lipodystrophy associated with antiretroviral therapy. The results show that the alterations in body shape can be disturbing in terms of psychosocial well being, affecting quality of life and increasing the stigma associated with the disease, with consequent disturbances in social relations. This analysis provides a preliminary review of the psychosocial aspects of lipodystrophy and further studies are needed for a better understanding of this complex syndrome, which could provide new information to be used in nursing care for HIV patients affected by this problem.Varios efectos secundarios han sido fuertemente asociados con la terapia antiretroviral en pacientes con HIV. Entre ellos, el sindrome de la lipodistrofia se presenta con alteraciones en la forma del cuerpo con hipertrofia adiposa central y lipoatrofia periferica, las cuales son reportadas por pacientes como marcas visibles que los identifica como pacientes con VIH. En este manuscrito, presentamos un analisis de literatura actual con respecto a los aspectos psicosociales de pacientes con VIH presentandose con lipodistrofia asociado con la terapia antiretroviral. Los resultados demuestran que las alteraciones de la forma del cuerpo pueden ser inquietantes en lo que se refiere al bienestar psicosocial, afectando la calidad de vida y aumentando el estigma asociado con la enfermedad, con las consiguientes dificultades en las relaciones sociales. Este analisis provee un repaso preliminar de los aspectos psicosociales de la lipodistrofia; sin embargo, otros estudios son necesarios para entender mejor este complejo sindrome, proveyendo nueva informacion para ser utilizada en el cuidado de enfermeria para pacientes con VIH que estan afectados por este problema.

Facial lipoatrophy: appearances are not deceiving.

&NA; Lipodystrophy syndrome (LS) has been reported as visible markers that can identify HIV status. Changes in body shape are detrimental in terms of psychological welfare and may affect well‐being and increase the stigma associated with HIV disease. In the current study, the psychosocial impact of LS was evaluated. A total of 84 HIV‐infected patients receiving antiretroviral therapy and exhibiting dyslipidemia were interviewed in an urban hospital setting in Brazil in 2006 using a standardized questionnaire. Of the 84 patients exhibiting dyslipidemia, 40 patients also exhibited body changes, and of these, 25 had facial lipoatrophy. From a psychosocial perspective, patients presenting with facial lipoatrophy reported alterations in self‐image and self‐esteem and believed that other people noticed their body changes. The results are relevant for nurses who need to be well‐prepared to recognize lipodystrophy, to implement nursing interventions including lifestyle changes, and to provide psychosocial support to patients with LS.

A pilot case-control association study of cytokine polymorphisms in Brazilian women presenting with HPV-related cervical lesions

OBJECTIVE AND STUDY DESIGN A case-control study was conducted on 42 Brazilian women presenting with human papilloma virus (HPV) infection and cervical lesion and 87 HPV-negative women to evaluate single nucleotide polymorphisms observed in TNF-alpha, TGF-beta, IL-10, IL-6, and IFN-gamma genes. RESULTS AND CONCLUSION No significant association was observed on the cytokine polymorphisms analyzed in this series. Larger studies using cytokine polymorphisms may be useful for providing further information regarding their influence or not in HPV-related cervical lesions.

Oviposition by Schistosoma mansoni during in vitro cultivation

Observation of Schistosoma mansoni oviposition during in vitro culture of adult worms for a maximum period of 10 days showed three well distinct phases in the kinetics of oviposition: an initial phase with low egg production, a period of maximum oviposition and finally a progressive reduction in the number of eggs during the late phases of culture. The kinetics of oviposition and the number of eggs laid by the parasites are influenced by the number of worm pairs per amount of RPMI 1640 medium, time of parasite development in the vertebrate host and type of serum utilized in the culture medium.

Immunolocalization of dentin matrix protein-1 in human primary teeth treated with different pulp capping materials

The aim of this study was to evaluate the immunolocalization of dentin matrix protein (DMP)-1 in human primary teeth treated with different pulp capping materials. Twenty-five primary molars were divided into the following groups: formocresol (FC), calcium hydroxide (CH), mineral trioxide aggregate (MTA), corticosteroid/antibiotic solution + CH (O + CH), and Portland cement (PC), and all received conventional pulpotomy treatment. The teeth at the regular exfoliation period were extracted for histological analysis and immunolocalization of DMP-1. Statistical analysis was performed using the χ(2) test (p < 0.05). Histological analysis revealed statistically significant differences in the comparison among the groups through the use of a score system regarding the presence of hard tissue barrier, odontoblastic layer, and internal resorption, but not regarding pulp calcification. Immunohistochemical analysis showed immunostaining for DMP-1 in groups CH, MTA, O + CH, and PC. Internal resorption was observed in the groups FC and CH. MTA and PC showed pulp repair without inflammation and with the presence of hard tissue barrier. DMP-1 immunostaining was higher for MTA and PC, confirming the reparative and bioinductive capacity of these materials.