BACKGROUND Recurrence is a hallmark of ocular toxoplasmosis (OT), and conditions that influence its occurrence remain a challenge. Natural killer cells (NK) are effectors cells whose primary is cytotoxic function against many parasites, including Toxoplasma gondii. Among the NK cell receptors, immunoglobulin-like receptors (KIR) deserve attention due to their high polymorphism. OBJECTIVES This study aimed to analyse the influence of KIR gene polymorphism in the course of OT infection and its association with recurrences after an active episode. METHODS Ninety-six patients from the Ophthalmologic Clinic of the National Institute of Infectology Evandro Chagas were followed for up to five years. After DNA extraction, genotyping of the patients was performed by polymerase chain reaction sequence-specific oligonucleotide (PCR-SSO) utilising Luminex equipment for reading. During follow-up, 60.4% had a recurrence. FINDINGS We identified 25 KIR genotypes and found a higher frequency of genotype 1 (31.7%) with worldwide distribution. We note that the KIR2DL2 inhibitor gene and the gene activator KIR2DS2 were more frequent in patients without recurrence. Additionally, we observed that individuals who carry these genes progressed recurrence episodes slowly compared to individuals who do not carry these genes. MAIN CONCLUSIONS The KIR2DL2 and KIR2DS2 are associated as possible protection markers against ocular toxoplasmosis recurrence (OTR).

Resumo A Organização Mundial da Saúde declarou a disseminação generalizada do SARS-CoV-2 e sua doença associada (COVID-19) uma emergência de saúde pública. O teste padrão ouro para detecção do vírus é o RT-PCR, realizado a partir de amostras de swab nasofaríngeo (NPS). No entanto, esse exame pode ser desconfortável para o paciente e requer treinamento específico e vestimenta do profissional de saúde responsável pela coleta da amostra. Portanto, a busca por formas alternativas de coleta de amostras que possam ser utilizadas no diagnóstico de COVID-19 é relevante. O objetivo deste estudo foi comparar os resultados obtidos em amostras de NPS e saliva. Amostras de NPS e saliva foram coletadas de 189 pacientes ambulatoriais sintomáticos com suspeita de COVID-19, que procuraram a Policlínica Piquet Carneiro. A extração de RNA foi realizada com o kit Bio-Gene DNA / RNA Viral Extraction (Bioclin®) e as reações em tempo real da reação em cadeia da polimerase-transcriptase reversa (RT-PCR) usaram o kit Molecular SARS-CoV-2 (E / RP) (Bio-Manguinhos). Os resultados indicaram que 142 apresentaram resultado não detectável (ND), enquanto 47 apresentaram resultado detectável (D). Entre os 142 "ND", 137 (94,4%) amostras de saliva obtiveram o mesmo resultado, enquanto 5 amostras (3,4%) foram "D". Dentre as 47 amostras de swab "D", 35 (74,4%) apresentaram o mesmo resultado nas amostras de saliva. A sensibilidade do teste de saliva foi de 0,74 e a especificidade foi de 0,97. O valor preditivo positivo foi de 0,88, enquanto o valor preditivo negativo foi de 0,92. Os resultados mostraram que a detecção de Sars-CoV-2 em amostras de saliva apresentou alta sensibilidade e especificidade quando comparada com swabs nasofaríngeos.

Abstract The World Health Organization has declared the widespread spread of SARS-CoV-2 and its associated disease (COVID-19) a public health emergency. The standard gold test for detecting the virus is the RT-PCR, performed from nasopharyngeal swab (NPS) samples. However, this test may be uncomfortable for the patient and requires specific training and attire from the health professional responsible for collecting the sample. Therefore, the search for alternative ways to collect samples that may be used in the diagnosis of COVID-19 is relevant. This study aimed to compare the results obtained from NPS and saliva samples. NPS and saliva samples were collected from 189 symptomatic outpatients suspected of COVID-19, who came to Piquet Carneiro Polyclinic. RNA extraction was performed using the Bio-Gene DNA/RNA Viral Extraction kit (Bioclin®). Real-time reverse transcriptase-polymerase chain reaction (RT-PCR) reactions used the Molecular SARS-CoV-2 (E / RP) kit (Bio-Manguinhos). The results indicated that 142 showed a non-detectable result (ND), while 47 showed a detectable result (D). Among the 142 "ND", 137 (94.4%) saliva samples obtained the same result, while 5 samples (3.4%) were "D". Among the 47 "D" swab samples, 35 (74.4%) showed the same result in the saliva samples. The sensitivity of the saliva test was 0.74 and the specificity was 0.97. The positive predictive value was 0.88 while the negative predictive value was 0.92. The results showed that detection of Sars-CoV-2 using saliva samples showed high sensitivity and specificity compared to nasopharyngeal swabs.

Abstract INTRODUCTION Rio de Janeiro has hardly experienced coronavirus disease. METHODS Here, 87,442 reverse transcription polymerase chain reaction (RT-PCR) test results for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were reported among Rio de Janeiro residents (March to September 2020). RESULTS Overall, RT-PCR positivity of 44.6% decreased over time towards 20%. Positivity was greater among males (OR=1.22; 95%CI:1.19-1.26); Black (OR=1.10; 95%CI:1.02-1.19), Brown (OR=1.16; 95%CI:1.10-1.22), and indigenous people (OR=2.11; 95%CI:0.88-5.03) compared to Whites and increased with age; with epidemic spread from the capital to inland regions. CONCLUSIONS SARS-CoV-2 keeps spreading in Rio de Janeiro, and reopening of activities may fuel the epidemic.

Background: In Brazil, mathematical models for deriving estimates and projections of COVID-19 cases have been developed without data on asymptomatic SARS-CoV-2 infection. We estimated the seroprevalence of antibodies to SARS-CoV-2 among blood donors in the State of Rio de Janeiro. Methods: Data were collected on 2,857 blood donors from April 14 to 27, 2020. We report the crude prevalence of antibodies to SARS-CoV-2, the weighted prevalence by the total state population, and adjusted prevalence estimates for test sensitivity and specificity. To establish the correlates of SARS-CoV-2 prevalence, we used logistic regression models. The analysis included period and site of blood collection, sociodemographic characteristics, and place of residence. Results: The proportion of SARS-Cov-2 positive tests without any adjustment was 4.0% (95% CI 3.3-4.7%), and the weighted prevalence was 3.8% (95% CI 3.1-4.5%). Further adjustment by test sensitivity and specificity produced lower estimates, 3.6% (95% CI 2.7-4.4%) and 3.3% (95% CI 2.6-4.1%), respectively. The variable most significantly associated with the crude prevalence was the period of blood collection: the later the period, the higher the prevalence. Regarding socio-demographic characteristics, the younger the blood donors, the higher the prevalence, and the lower the educational level, the higher the odds of a positive SARS-Cov-2 antibody. Similar results were found for the weighted prevalence. Discussion: Although our findings resulted from a convenience sample, they match some basic premises: the increasing trend over time, since the epidemic curve in the state is still on the rise; the higher prevalence among the youngest who are more likely to circulate; and the higher prevalence among the less educated as they have more difficulties in following the social distancing recommendations. Despite the study limitations, it is possible to infer that protective levels of natural herd immunity to SARS-CoV-2 are far from being reached in Rio de Janeiro.

Abstract Background: Polymorphisms of the filaggrin 2 gene (rs 12568784 and rs 16899374) are associated with persistent atopic dermatitis in African American patients. Filaggrin 2 is a protein with a function similar to filaggrin and also encoded in the epidermal differentiation complex on chromosome 1q21. Objective: To evaluate the polymorphisms in the filaggrin 2 gene (rs 12568784 and rs 16899374) in children and adults with atopic dermatitis and to verify the association of these with the severity of the clinical picture, presence of other allergic diseases, and socio-demographic factors. Method: The study was carried out with patients and control group. Questionnaires were used to evaluate ethnicity, sex, age, family history, scoring, atopic dermatitis (SCORAD), among other parameters. Genotyping of the filaggrin 2 gene was performed by real-time polymerase chain reaction. Results: Forty-eight patients and 83 controls were evaluated. No correlation was found between the variables studied in patients with atopic dermatitis and polymorphisms, no significant difference between the prevalence of polymorphisms in the patients and in the control group p > 0.05. Study limits: The exclusive use of self-reported ethnicity information and the sample size. Results: The results of this work can be an incentive for the study of the polymorphisms in atopic dermaititis, considering the characteristic of the Brazilian multi ethnic population. Conclusion: This is an unpublished work in Brazil and the first study in the world to have a control group to evaluate alterations in the gene of filaggrin 2.

ABSTRACT OBJECTIVE To estimate the seroprevalence of antibodies to SARS-CoV-2 among blood donors in the state of Rio de Janeiro, Brazil. METHODS Data were collected on 2,857 blood donors from April 14 to 27, 2020. This study reports crude prevalence of antibodies to SARS-CoV-2, population weighted prevalence for the state, and prevalence adjusted for test sensitivity and specificity. Logistic regression models were used to establish the correlates of SARS-CoV-2 prevalence. For the analysis, we considered collection period and site, sociodemographic characteristics, and place of residence. RESULTS The proportion of positive tests for SARS-Cov-2, without any adjustment, was 4.0% (95%CI 3.3–4.7%), and the weighted prevalence was 3.8% (95%CI 3.1–4.5%). We found lower estimates after adjusting for test sensitivity and specificity: 3.6% (95%CI 2.7–4.4%) for the non-weighted prevalence, and 3.3% (95%CI 2.6–4.1%) for the weighted prevalence. Collection period was the variable most significantly associated with crude prevalence: the later the period, the higher the prevalence. Regarding sociodemographic characteristics, the younger the blood donor, the higher the prevalence, and the lower the education level, the higher the odds of testing positive for SARS-Cov-2 antibody. We found similar results for weighted prevalence. CONCLUSIONS Our findings comply with some basic premises: the increasing trend over time, as the epidemic curve in the state is still on the rise; and the higher prevalence among both the youngest, for moving around more than older age groups, and the less educated, for encountering more difficulties in following social distancing recommendations. Despite the study limitations, we may infer that Rio de Janeiro is far from reaching the required levels of herd immunity against SARS-CoV-2.

ABSTRACT OBJECTIVE To estimate the seroprevalence of antibodies to SARS-CoV-2 among blood donors in the state of Rio de Janeiro, Brazil. METHODS Data were collected on 2,857 blood donors from April 14 to 27, 2020. This study reports crude prevalence of antibodies to SARS-CoV-2, population weighted prevalence for the state, and prevalence adjusted for test sensitivity and specificity. Logistic regression models were used to establish the correlates of SARS-CoV-2 prevalence. For the analysis, we considered collection period and site, sociodemographic characteristics, and place of residence. RESULTS The proportion of positive tests for SARS-Cov-2, without any adjustment, was 4.0% (95%CI 3.3–4.7%), and the weighted prevalence was 3.8% (95%CI 3.1–4.5%). We found lower estimates after adjusting for test sensitivity and specificity: 3.6% (95%CI 2.7–4.4%) for the non-weighted prevalence, and 3.3% (95%CI 2.6–4.1%) for the weighted prevalence. Collection period was the variable most significantly associated with crude prevalence: the later the period, the higher the prevalence. Regarding sociodemographic characteristics, the younger the blood donor, the higher the prevalence, and the lower the education level, the higher the odds of testing positive for SARS-Cov-2 antibody. We found similar results for weighted prevalence. CONCLUSIONS Our findings comply with some basic premises: the increasing trend over time, as the epidemic curve in the state is still on the rise; and the higher prevalence among both the youngest, for moving around more than older age groups, and the less educated, for encountering more difficulties in following social distancing recommendations. Despite the study limitations, we may infer that Rio de Janeiro is far from reaching the required levels of herd immunity against SARS-CoV-2.

Abstract: Porphyria cutanea tarda has a complex etiology with genetic factors not completely elucidated. The miscegenation of the Brazilian population has important implications in the predisposition to diseases. There are no studies concerning the genetic ancestry of patients with porphyria cutanea tarda from a mixed population. Thirty patients living in Rio de Janeiro with sporadic porphyria cutanea tarda were studied for the genetic ancestry through informative markers - INDELS. There was a significant predominance of European ancestry across the sample of patients with porphyria cutanea tarda (70.2%), and a small contribution of African and Amerindian ancestry, 20.1% and 10.9%, respectively.

Os nevos epidérmicos verrucosos são hamartomas congênitos compostos por queratinócitos, que podem ocorrer isolados ou associados a alterações do desenvolvimento. Com a recente observação de uma relação estreita entre variações nos genes PIK3CA e FGFR3 e o aparecimento do nevo, realizamos ensaios moleculares para identificação das mutações E542K, E545G/K e H1047R do gene PIK3CA, e R248C do gene FGFR3. Interessantemente, durante o processo de amplificação não observamos o produto da PCR do exon 9 do gene PIK3CA, região que compreende aos aminoácidos 542-545, sugerindo fortemente a ocorrência de uma microdeleção da região e indicando uma provável variante alélica ainda não descrita na literatura.

Verrucous epidermal nevi are congenital hamartomas composed of keratinocytes and may occur alone or in association with developmental abnormalities. A close relationship between variations in the PIK3CA and FGFR3 genes and the appearance of nevi has been recently reported. Based on that, we performed molecular assays for the identification of E542K, E545G/K and H1047R mutations in the PIK3CA gene and of the R248C mutation in the FGFR3 gene. Interestingly, during the amplification process, we did not observe the PCR product of exon 9 of the PIK3CA gene, a region comprising amino acids 542-545. This strongly suggests the occurrence of a microdeletion of that region and indicates a possible allelic variant, which has not yet being described in the literature.

FUNDAMENTO: o tabagismo apresenta importante papel sobre as doenças cardiovasculares, entretanto permanecem pouco compreendidos os motivos pelos quais alguns seres humanos as desenvolvem e outros não. OBJETIVO: nosso objetivo foi analisar o perfil redox do coração de diferentes linhagens de camundongos após exposição à fumaça de cigarro. MÉTODOS: camundongos machos suíços (n = 10), C3H (n = 10), BALB/c (n = 10) e C57BL/6 (n = 10) foram expostos à fumaça de cigarro (12 cigarros/dia), enquanto os respectivos controles (n = 10) ao ar ambiente por 60 dias. Após sacrifício, o coração foi retirado para análises bioquímicas. RESULTADOS: embora o conteúdo de malondialdeído não tenha aumentado em nenhum grupo, a atividade da catalase diminuiu no grupo suíço (p < 0,05), BALB/c (p < 0,05) quando comparados aos respectivos grupos-controle, enquanto a mieloperoxidase diminuiu no grupo C3H (p < 0,05) e C57BL/6 (p < 0,001) quando comparados aos respectivos grupos controle. O conteúdo de glutationa reduzida diminuiu nos grupos suíço, C3H, C57BL/6 (p < 0,05) e no grupo BALB/c (p < 0,001) quando comparados com os respectivos controles. Observamos aumento do conteúdo da glutationa oxidada no grupo Suíço (p < 0,05) e diminuição nos grupos C3H (p < 0,05) e BALB/c (p < 0,001) quando comparados aos respectivos grupos-controle. A razão glutationa reduzida/ glutationa oxidada apresentou redução nos grupos suíço e C57BL/6 (p < 0.05) quando comparados aos grupos controle. CONCLUSÃO: o background genético nos camundongos pode influenciar na resposta antioxidante após a exposição à fumaça de cigarro e parece ser um fator determinante para o desequilíbrio redox no suíço e C57BL/6. Compreender as respostas antioxidantes e do background genético C3H e BALB/c podem fornecer importantes informações quanto à resistência cardíaca a fumaça de cigarro.

BACKGROUND: Smoking plays an important role in cardiovascular diseases. However, the reasons why some individuals develop those diseases and others do not remain to be explained. OBJECTIVE: This study aimed at assessing the redox profile of the heart of different mouse strains after exposure to cigarette smoke. METHODS: Male mice of the Swiss (n = 10), C3H (n = 10), BALB/c (n = 10) and C57BL/6 (n = 10) strains were exposed to cigarette smoke (12 cigarettes/day), while their respective controls (n = 10) were exposed to ambient air for 60 days. After being euthanized, their heart was removed for biochemical analyses. RESULTS: Although the malondialdehyde content did not increase in any of the groups, catalase activity decreased in the Swiss (p < 0.05) and BALB/c (p < 0.05) strain mice as compared with their respective control groups, while myeloperoxidase decreased in the C3H (p < 0.05) and C57BL/6 (p < 0.001) strain mice as compared with their respective control groups. The reduced glutathione content decreased in the Swiss, C3H, C57BL/6 (p < 0.05) and BALB/c (p < 0,001) strain mice as compared with their respective control groups. Regarding reduced glutathione content, an increase was observed in the Swiss strain mice (p < 0.05), while a decrease was observed in the C3H (p < 0.05) and BALB/c (p < 0.001) strain mice as compared with their respective control groups. The reduced glutathione/reduced glutathione ratio showed a reduction in the Swiss and C57BL/6 (p < 0.05) strain mice as compared with their respective control groups. CONCLUSIONS: The genetic background of mice can influence the antioxidant response after exposure to cigarette smoke and seems to be a determinant factor for redox imbalance in Swiss and C57BL/6 strain mice. Understanding antioxidant responses and genetic background of C3H and BALB/c strain mice might provide important information regarding cardiac resistance to cigarette smoke.

OBJETIVO: A ventilação mecânica (VM) por si própria pode contribuir diretamente para a lesão pulmonar. Assim, o objetivo do presente estudo foi investigar biomarcadores precoces relacionados ao equilíbrio oxidantes/antioxidantes, estresse oxidativo e inflamação causados por VM de curta duração em pulmões de camundongos saudáveis. MÉTODOS: Vinte camundongos C57BL/6 machos foram randomicamente divididos em dois grupos: VM, submetidos a VM com baixo volume corrente (V T, 6 mL/kg) por 30 min; e respiração espontânea (RE), utilizados como controles. Amostras de homogeneizados de pulmão foram testados quanto à atividade de enzimas antioxidantes, peroxidação lipídica e expressão de TNF-α. RESULTADOS: Comparados ao grupo RE, houve uma redução significativa na atividade de superóxido dismutase (≈35%; p < 0,05) e aumento da atividade de catalase (40%; p < 0,01), glutationa peroxidase (500%; p < 0,001) e mieloperoxidase (260%; p < 0,001), ao passo que a razão glutationa reduzida/glutationa oxidada foi menor (≈50%; p < 0,05), e houve um aumento na atividade de expressão de TNF-α no grupo VM. O dano oxidativo, analisado como peroxidação lipídica, também aumentou no grupo VM (45%; p < 0.05). CONCLUSÕES: Nossos resultados demonstraram que VM de curta duração com baixa V T pode contribuir diretamente para a lesão pulmonar, gerando estresse oxidativo e inflamação em pulmões de camundongos saudáveis.

OBJECTIVE: Mechanical ventilation (MV) itself can directly contribute to lung injury. Therefore, the aim of the present study was to investigate early biomarkers concerning oxidant/antioxidant balance, oxidative stress, and inflammation caused by short-term MV in healthy mouse lungs. METHODS: Twenty male C57BL/6 mice were randomly divided into two groups: MV, submitted to low tidal volume (V T, 6 mL/kg) MV for 30 min; and spontaneous respiration (SR), used as controls. Lung homogenate samples were tested regarding the activity of various antioxidant enzymes, lipid peroxidation, and TNF-α expression. RESULTS: In comparison with the SR group, the MV group showed a significant decrease in the activity of superoxide dismutase (≈35%; p < 0.05), together with an increase in the activity of catalase (40%; p < 0.01), glutathione peroxidase (500%; p < 0.001), and myeloperoxidase (260%; p < 0.001), as well as a reduction in the glutathione/oxidized glutathione ratio (≈50%; p < 0.05) and an increase in TNF-α expression in the MV group. Oxidative damage, assessed by lipid peroxidation, was also greater in the MV group (45%; p < 0.05). CONCLUSIONS: Our results show that short-term low V T MV can directly contribute to lung injury, generating oxidative stress and inflammation in healthy mouse lungs.

Mutations located in the 109-amino acid fragment of NS5B are typically associated with resistance to interferon (IFN) and ribavirin (RIB) and to new antiviral drugs. The prevalence of these mutations was examined in 69 drug-naïve individuals with hepatitis C virus (HCV) infections in Rio de Janeiro, Brazil. Mutations related to non-response to IFN/RIB were observed in all subtypes studied (1a, 1b, 2b, 3a and 4). The most common mutation was Q309R, present in all subtypes, except subtype 2b with frequency above 20%. D244N was detected only in subtype 3a and A333E was detected only in subtype 2b. We did not detect the S282T, S326G or T329I mutations in any of the samples analysed. Of note, the C316N mutation, previously related to a new non-nucleoside compound (HCV796 and AG-021541), was observed in only eight of 33 (24%) samples from subtype 1b. Site 316 was under positive selection in this HCV variant. Our data highlight the presence of previously described resistance mutations in HCV genotypes from drug-naïve patients.

Os alelos HLA-DRB1, que codificam uma sequência de aminoácidos (QKRAA/QRRAA/RRRAA) nas posições 70 a 74 da terceira região hipervariável da cadeia β1 do gene DRB1, denominada epítopo compartilhado (EC), estão associados a maior suscetibilidade e gravidade para artrite reumatoide (AR) em diversas populações. OBJETIVO: Determinar a frequência dos alelos HLA-DRB1 em pacientes brasileiros com AR, e sua associação a fator reumatoide (FR) e anticorpos antipeptídeos citrulinados (ACPA). MATERIAL E MÉTODOS: Foram incluídos 412 pacientes com AR e 215 controles. A tipificação HLA-DRB1 foi realizada pela reação em cadeia da polimerase (PCR) usando primers específicos e hibridização com oligonucleotídeos de sequência específica (SSOP). A pesquisa de ACPA foi determinada pela técnica de ELISA, e a do FR por nefelometria. Para análises estatísticas foram utilizados os testes do qui-quadrado e t de Student e a regressão logística. RESULTADOS: Alelos HLA-DRB1*04:01, *04:04 e *04:05 associaram-se à AR (P < 0,05)); a despeito do amplo intervalo de confiança, vale a pena ressaltar a associação observada entre o alelo DRB1*09:01 e a doença (P < 0,05). Alelos HLA-DRB1 EC+ foram observados em 62,8% dos pacientes e em 31,1% do grupo-controle (OR 3,62; P < 0,001) e estiveram associados a ACPA (OR 2,03; P < 0,001). Alelos DRB1-DERAA mostraram efeito protetor para AR (OR 0,42; P < 0,001). CONCLUSÃO: Em uma amostra de pacientes brasileiros com AR de etnia majoritariamente mestiça, alelos HLA-DRB1 EC+ estiveram associados à suscetibilidade à doença e à presença de ACPA.

The HLA-DRB1 alleles encoding an amino acid sequence (QKRAA/QRRAA/RRRAA) at position 70 74 of the third hypervariable region of the β1 chain of the HLA-DRB1 gene, called shared epitope (SE), are associated with increased susceptibility to and severity of rheumatoid arthritis (RA) in different populations. OBJECTIVE: To determine the frequency of HLA-DRB1 alleles in Brazilian patients with RA and their association with rheumatoid factor (RF) and anti-citrullinated peptide antibodies (ACPA). METHODS: Four hundred and twelve patients with RA (ACR 1987) and 215 controls were included. HLA-DRB1 typing was performed by use of polymerase chain reaction (PCR) with specific primers and hybridization with sequence-specific oligonucleotide probe (SSOP). ACPA was measured by use of the ELISA technique and RF by nephelometry. The statistical analysis comprised the chi-square and Student t tests and logistic regression. RESULTS: HLA-DRB1*04:01, *04:04, *04:05 alleles were associated with RA (P < 0.05); despite the wide confidence interval, it is worth noting the association between the DRB1*09:01 allele and RA (P < 0.05). HLA-DRB1 SE+ alleles were observed in 62.8% of the patients and in 31.1% of controls (OR 3.62; P < 0.001) and were associated with ACPA (OR 2.03; P < 0.001). DRB1-DERAA alleles showed a protective effect against RA (OR 0.42; P < 0.001). CONCLUSION: In a sample of Brazilian patients with RA, most of whom of mixed heritage, HLA-DRB1 SE+ alleles were associated with susceptibility to disease and presence of ACPA.

The ultimate goal of periodontal therapy is to repair the damaged periodontal supporting tissues, permitting regeneration of the periodontal ligament. However, the cell response, the supportive matrix and the bioactive molecules use have not yet been well established. Bone marrow mononuclear cells were extracted from rat femurs and tibiae and cultured on a cross-linked collagen membrane, bone graft, or molar tooth to compare cell attachment and early proliferation on these materials. Cell attachment was quantified by light microscopy at 24, 48 and 72h, and cell proliferation was observed under a SEM after 72h. After 24h, the number of cells on bone graft was similar to that of the control and more than twice compared to collagen membrane (q=7.473 p<0.001) and 1.75 times greater than with tooth cementum (q=5.613 p<0.01). However, the number of cells close to bone graft decreased in the second day compared to the control. SEM examination revealed a significant decrease in the number of cells that attached and proliferated on tooth and bone graft when compared with membrane. The results showed that bone marrow mesenchymal cells offer great potential for colonize a collagen membrane.

El objetivo último de la terapia periodontal es reparar el daño tejidos periodontales de soporte, permitiendo la regeneración del ligamento periodontal. Sin embargo, la respuesta de la célula, la matriz de apoyo y las moléculas bioactivas aún no han sido bien establecidas. Células mononucleares de la médula ósea se extrajeron del fémur y fibula de rata, y fueron cultivadas sobre un reticulado de membrana de colágeno, de injerto de hueso o de un diente molar para comparar la adhesión celular y la proliferación temprana sobre estos materiales. La adhesión celular fue cuantificada por microscopía de luz a las 24, 48 y 72h, y la proliferación celular fue observada bajo MEB después de 72h. Después de 24 horas, el número de células sobre el injerto de hueso fue similar a la del control y más del doble en comparación con la membrana de colágeno (q=7,473 p<0,001) y 1,75 veces mayor que con el cemento dental (q=5,613 p<0,01). Sin embargo, el número de células cerca del injerto óseo disminuyó el segundo día en comparación con el control. El examen al MEB reveló una disminución significativa en el número de células que se unen y proliferan sobre los dientes y el injerto óseo en comparación con la membrana. Los resultados mostraron que las células mesenquimales de la médula ósea tienen un gran potencial para colonizar la membrana de colágeno.