Prevalencia de Porphyromonas gingivalis en fluido gingival y su relación con la periodontitis / Prevalence of Porphyromonas gingivalis in gingival fluid and its relationship with periodontitis

Introducción: la periodontitis es una enfermedad infecciosa multifactorial asociada a un biofilm de microorganismos patógenos. Objetivo: el objetivo del trabajo fue establecer la prevalencia de Porphyromonas gingivalis en pacientes con periodontitis y relacionarla con la severidad de la enfermedad. Material y métodos: participaron 45 pacientes, sistémicamente saludables, con edades entre 35 y 65 años. El grado de periodontitis se definió según los criterios de Papapanou y colaboradores. Como grupo control, se incluyeron 20 sujetos de ambos sexos sin periodontitis y sin enfermedades sistémicas. Se tomaron muestras de fluido gingival en dos sitios más profundos. Porphyromonas gingivalis se detectó por PCR (reacción en cadena de la polimerasa). Resultados: la frecuencia relativa de periodontitis fue de 13.3% grado I, 46.7% grado II y 40% grado III. El sexo masculino presentó periodontitis grado III 72.2% y grado II 52.3%. El grado I se registró con mayor frecuencia en el sexo femenino, 66.7%. La prevalencia de Porphyromonas gingivalis en la población con periodontitis fue de 44.4%. Se obtuvieron diferencias estadísticamente significativas entre los grados de severidad de periodontitis y la presencia de Porphyromonas gingivalis (p = 0.0002, α = 5%). Conclusión: la periodontitis predominó en el sexo masculino. La prevalencia de Porphyromonas gingivalis en la población con periodontitis crónica fue de 44.4% y su presencia está relacionada con la severidad (AU)

Introduction: periodontitis is a multifactorial infectious disease associated with a biofilm of pathogenic microorganisms. Objective: the objective of the work was to establish the prevalence of Porphyromonas gingivalis in patients with periodontitis and relate it to the severity of the disease. Material and methods: 45 systemically healthy patients, aged between 35 and 65 years old, participated. The degree of periodontitis was defined according to the criteria of Papapanou et al. As a control group, 20 patients of both sexes without periodontitis and without systemic diseases were included. Gingival fluid samples were taken from two deeper sites. Porphyromonas gingivalis was detected by PCR (polymerase chain reaction). Results: the relative frequency of periodontitis was 13.3% grade I, 46.7% grade II and 40% grade III. The male sex presented periodontitis grade III 72.2% and grade II 52.3%. Grade I was recorded more frequently in the female sex, 66.7%. The prevalence of Porphyromonas gingivalis in the population with periodontitis was 44.4%. Statistically significant differences were obtained between the degrees of severity of periodontitis and the presence of Porphyromonas gingivalis (p = 0.0002, α = 5%). Conclusion: periodontitis predominated in males. The prevalence of Porphyromonas gingivalis in the population with chronic periodontitis was 44.4% and its presence is related to severity (AU)

Omicron Waves in Argentina: Dynamics of SARS-CoV-2 Lineages BA.1, BA.2 and the Emerging BA.2.12.1 and BA.4/BA.5.

The COVID-19 pandemic has lately been driven by Omicron. This work aimed to study the dynamics of SARS-CoV-2 Omicron lineages during the third and fourth waves of COVID-19 in Argentina. Molecular surveillance was performed on 3431 samples from Argentina, between EW44/2021 and EW31/2022. Sequencing, phylogenetic and phylodynamic analyses were performed. A differential dynamic between the Omicron waves was found. The third wave was associated with lineage BA.1, characterized by a high number of cases, very fast displacement of Delta, doubling times of 3.3 days and a low level of lineage diversity and clustering. In contrast, the fourth wave was longer but associated with a lower number of cases, initially caused by BA.2, and later by BA.4/BA.5, with doubling times of about 10 days. Several BA.2 and BA.4/BA.5 sublineages and introductions were detected, although very few clusters with a constrained geographical distribution were observed, suggesting limited transmission chains. The differential dynamic could be due to waning immunity and an increase in population gatherings in the BA.1 wave, and a boosted population (for vaccination or recent prior immunity for BA.1 infection) in the wave caused by BA2/BA.4/BA.5, which may have limited the establishment of the new lineages.

Blockade of B7-H1 improves myeloid dendritic cell-mediated antitumor immunity.

Suppression of dendritic cell function in cancer patients is thought to contribute to the inhibition of immune responses and disease progression. Molecular mechanisms of this suppression remain elusive, however. Here, we show that a fraction of blood monocyte-derived myeloid dendritic cells (MDCs) express B7-H1, a member of the B7 family, on the cell surface. B7-H1 could be further upregulated by tumor environmental factors. Consistent with this finding, virtually all MDCs isolated from the tissues or draining lymph nodes of ovarian carcinomas express B7-H1. Blockade of B7-H1 enhanced MDC-mediated T-cell activation and was accompanied by downregulation of T-cell interleukin (IL)-10 and upregulation of IL-2 and interferon (IFN)-gamma. T cells conditioned with the B7-H1-blocked MDCs had a more potent ability to inhibit autologous human ovarian carcinoma growth in non-obese diabetic-severe combined immunodeficient (NOD-SCID) mice. Therefore, upregulation of B7-H1 on MDCs in the tumor microenvironment downregulates T-cell immunity. Blockade of B7-H1 represents one approach for cancer immunotherapy.