Background: Regulatory T cells (Tregs) modulate the host response in infectious diseases and are key mediators of peripheral tolerance. Cryopreservation of peripheral blood mononuclear cells (PBMCs) is commonly used in immunological field studies where access to complex laboratory tests is not feasible. Our objective is to assess the effects of cryopreservation on the flow cytometric detection of surface and intracellular markers of Tregs.Methods: Heparinized venous blood was obtained from 36 healthy individuals and 15 HIV-1 infected subjects. PBMCs were isolated and stained for surface and intracellular markers of Tregs. PBMCs from each subject were cryopreserved in liquid nitrogen with DMSO; these cells were thawed and stained at a later date. All samples were analyzed by flow cytometry. The proportion of Tregs was compared using Wilcoxon signed-rank test.Results: Cryopreservation decreased the proportion of Tregs identified by surface and intracellular markers in healthy individuals and in HIV-1 patients. The proportion of CD41CD251FoxP31 was decreased from 3.13 to 2.16% (P < 0.001) for non-HIV subjects and from 2.68 to 0.94% (P < 0.001) for HIV subjects, compared to fresh samples. Significant reduction was also observed for CD41CD251CD127lo-neg. However, the effect varied considerably between samples. The effect was similar among HIV and non-HIV patients (P 5 0.38).Conclusions: Cryopreservation modulates the detection of surface and intracellular markers of Tregs. These results confirm that research on Tregs, including studies of HIV-1 infected patients, should be carried out prospectively on fresh samples in order to obtain unbiased conclusions. Results using cryopreserved cells should be regarded as only preliminary. V C 2011 International Clinical Cytometry Society

Rationale, aims and objectives Efforts to implement evidence-based medicine (EBM) training in developing countries are limited. We describe the results of an international effort to improve research capacity in a developing country; we conducted a course aimed at improving basic EBM attitudes and identified challenges. Method Between 2005 and 2009, we conducted an annual 3-day course in Perú consisting of interactive lectures and case-based workshops. We assessed self-reported competence and importance in EBM using a Likert scale (1 = low, 5 = high). Results Totally 220 clinicians participated. For phase I (2005–2007), self-reported EBM competence increased from a median of 2 to 3 (P < 0.001) and the perceived importance of EBM did not change (median = 5). For phase II (2008–2009), before the course, 8–72% graded their competence very low (score of 1–2). After the course, 67–92% of subjects graded their increase in knowledge very high (score of 4–5). The challenges included limited availability of studies relevant to the local reality written in Spanish, participants’ limited time and lack of long-term follow-up on practice change. Informal discussion and written evaluation from participants were universally in agreement that more training in EBM is needed. Conclusions In an EBM course in a resource-poor country, the baseline self-reported competence and experience on EBM were low, and the course had measurable improvements of self-reported competence, perceived utility and readiness to incorporate EBM into their practices. Similar to developed countries, translational research and building the research capacity in developing countries is critical for translating best available evidence into practice.

Background The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which resulted in the worldwide coronavirus disease 2019 (COVID-19) pandemic of 2020, has particularly affected Latin America. Objective The purpose of the study was to analyze the imaging findings of pulmonary COVID-19 in a large pediatric series. Materials and methods Children with SARS-CoV-2 infection confirmed by either quantitative reverse transcription-polymerase chain reaction from nasopharyngeal swabs or presence of circulating immunoglobulin M (IgM) antibodies and who underwent chest radiograph or CT or both were included in this retrospective multicenter study. Three pediatric radiologists independently reviewed radiographs and CTs to identify the presence, localization, distribution and extension of pulmonary lesions. Results We included 140 children (71 female; median age 6.3 years, interquartile range 1.6–12.1 years) in the study. Peribronchial thickening (93%), ground-glass opacities (79%) and vascular engorgement (63%) were the most frequent findings on 131 radiographs. Ground-glass opacities (91%), vascular engorgement (84%) and peribronchial thickening (72%) were the most frequent findings on 32 CTs. Peribronchial thickening (100%), ground-glass opacities (83%) and pulmonary vascular engorgement (79%) were common radiograph findings in asymptomatic children ( n =25). Ground-glass opacity and consolidation were significantly higher in children who needed intensive care admission or died (92% and 48%), in contrast with children with a favorable outcome (71% and 24%, respectively; P <0.05). Conclusion Asymptomatic children and those with mild symptoms of COVID-19 showed mainly peribronchial thickening, ground-glass opacities and pulmonary vascular engorgement on radiographs. Ground-glass opacity and consolidation were more common in children who required intensive care admission or died. Supplementary Information The online version contains supplementary material available at 10.1007/s00247-021-05055-2.

No abstract

La pandemia del COVID-19 en el Perú está causando una presión inusual a nuestros recursos hospitalarios y de cuidados críticos. A medida que la infección progresa en la población, esperamos ver un alza en los casos severos y en la demanda de unidad de cuidados intensivos (UCI) donde la capacidad de camas puede ser excedida. A pesar de que usualmente el COVID-19 causa una enfermedad poco grave en los niños, debemos estar preparados para que el numero de casos pediátricos ocasionen una sobrecarga en la capacidad de recursos hospitalarios. En un escenario de un 25% de proporción de infección acumulada en la población, podremos ver aproximadamente 891 niños críticamente enfermos que requieren hospitalización en UCI. Proponemos algunas estrategias para enfrentar la escasez de recursos de cuidados intensivos que permitan asegurar la atención de niños vulnerables con condiciones agudas y condiciones complejas que siguen incidiendo en los tiempos de pandemia.