Retinoic acid is essential for Th1 cell lineage stability and prevents transition to a Th17 cell program.

CD4(+) T cells differentiate into phenotypically distinct T helper cells upon antigenic stimulation. Regulation of plasticity between these CD4(+) T-cell lineages is critical for immune homeostasis and prevention of autoimmune disease. However, the factors that regulate lineage stability are largely unknown. Here we investigate a role for retinoic acid (RA) in the regulation of lineage stability using T helper 1 (Th1) cells, traditionally considered the most phenotypically stable Th subset. We found that RA, through its receptor RARα, sustains stable expression of Th1 lineage specifying genes, as well as repressing genes that instruct Th17-cell fate. RA signaling is essential for limiting Th1-cell conversion into Th17 effectors and for preventing pathogenic Th17 responses in vivo. Our study identifies RA-RARα as a key component of the regulatory network governing maintenance and plasticity of Th1-cell fate and defines an additional pathway for the development of Th17 cells.

Leukocyte homing, fate, and function are controlled by retinoic acid.

Although vitamin A was recognized as an "anti-infective vitamin" over 90 years ago, the mechanism of how vitamin A regulates immunity is only beginning to be understood. Early studies which focused on the immune responses in vitamin A-deficient (VAD) animals clearly demonstrated compromised immunity and consequently increased susceptibility to infectious disease. The active form of vitamin A, retinoic acid (RA), has been shown to have a profound impact on the homing and differentiation of leukocytes. Both pharmacological and genetic approaches have been applied to the understanding of how RA regulates the development and differentiation of various immune cell subsets, and how RA influences the development of immunity versus tolerance. These studies clearly show that RA profoundly impacts on cell- and humoral-mediated immunity. In this review, the early findings on the complex relationship between VAD and immunity are discussed as well as vitamin A metabolism and signaling within hematopoietic cells. Particular attention is focused on how RA impacts on T-cell lineage commitment and plasticity in various diseases.

CCR6-dependent positioning of memory B cells is essential for their ability to mount a recall response to antigen.

Chemokine-dependent localization of specific B cell subsets within the immune microarchitecture is essential to ensure successful cognate interactions. Although cognate interactions between T cells and memory B cells (B(mem)) are essential for the secondary humoral immune responses, the chemokine response patterns of B(mem) cells are largely unknown. In contrast to naive B cells, this study shows that Ag-specific B(mem) cells have heightened expression of CCR6 and a selective chemotactic response to the CCR6 ligand, CCL20. Although CCR6 appears be nonessential for the initial clonal expansion and maintenance of B(mem), CCR6 is essential for the ability of B(mem) to respond to a recall response to their cognate Ag. This dependency was deemed intrinsic by studies in CCR6-deficient mice and in bone marrow chimeric mice where CCR6 deficiency was limited to the B cell lineage. Finally, the mis-positioning of CCR6-deficient B(mem) was revealed by immunohistological analysis with an altered distribution of CCR6-deficient B(mem) from the marginal and perifollicular to the follicular/germinal center area.

Toll-like receptor 4-dependent contribution of the immune system to anticancer chemotherapy and radiotherapy.

Conventional cancer treatments rely on radiotherapy and chemotherapy. Such treatments supposedly mediate their effects via the direct elimination of tumor cells. Here we show that the success of some protocols for anticancer therapy depends on innate and adaptive antitumor immune responses. We describe in both mice and humans a previously unrecognized pathway for the activation of tumor antigen-specific T-cell immunity that involves secretion of the high-mobility-group box 1 (HMGB1) alarmin protein by dying tumor cells and the action of HMGB1 on Toll-like receptor 4 (TLR4) expressed by dendritic cells (DCs). During chemotherapy or radiotherapy, DCs require signaling through TLR4 and its adaptor MyD88 for efficient processing and cross-presentation of antigen from dying tumor cells. Patients with breast cancer who carry a TLR4 loss-of-function allele relapse more quickly after radiotherapy and chemotherapy than those carrying the normal TLR4 allele. These results delineate a clinically relevant immunoadjuvant pathway triggered by tumor cell death.

Sex-dependent effects of angiotensin II type 1 receptor blocker on molecular and behavioral changes induced by single prolonged stress.

Post-traumatic stress disorder (PTSD) is a neuropsychiatric disorder that not only entails alterations in fear behavior and anxiety but also includes neuroendocrine dysfunctions involving the hypothalamic pituitary adrenal (HPA) axis and the renin-angiotensin system. Recent preclinical studies demonstrate that activation of the angiotensin type 1 receptor (AT1R) in the paraventricular region of the hypothalamus (PVR) promotes anxiety-like behaviors and enables microglia proliferation. An increase in microglia and anxiety-like behavior also occurs in the PTSD animal model single-prolonged stress (SPS). In the present study, we tested whether AT1Rs contribute to the effects of SPS on behavior and microglia in brain structures important for HPA axis regulation and fear behavior. To test this, male and female animals were exposed to SPS and then given the oral AT1R antagonist candesartan beginning one week later. Candesartan did not alter auditory fear conditioning or extinction in SPS-exposed male or female animals. However, we found that the male animals exposed to SPS showed increased anxiety-like behavior, which was reversed by candesartan. In contrast, neither SPS nor candesartan altered anxiety-like behavior in the female animals. At the molecular level, SPS increased the cellular expression of AT1Rs in the PVR of male animals and candesartan reversed this effect, whereas AT1Rs in the PVR of females were unaltered by either SPS or candesartan. Iba1-expressing microglia increased in the PVR after SPS exposure and was reversed by candesartan in both sexes suggesting that SPS stimulates AT1Rs to increase microglia in the PVR. Collectively, these results suggest that the contribution of AT1Rs to the molecular and behavioral effects of SPS is sex-dependent.

The Current Situation Regarding Long-Acting Insulin Analogues Including Biosimilars Among African, Asian, European, and South American Countries; Findings and Implications for the Future.

Background: Diabetes mellitus rates continue to rise, which coupled with increasing costs of associated complications has appreciably increased global expenditure in recent years. The risk of complications are enhanced by poor glycaemic control including hypoglycaemia. Long-acting insulin analogues were developed to reduce hypoglycaemia and improve adherence. Their considerably higher costs though have impacted their funding and use. Biosimilars can help reduce medicine costs. However, their introduction has been affected by a number of factors. These include the originator company dropping its price as well as promoting patented higher strength 300 IU/ml insulin glargine. There can also be concerns with different devices between the manufacturers. Objective: To assess current utilisation rates for insulins, especially long-acting insulin analogues, and the rationale for patterns seen, across multiple countries to inform strategies to enhance future utilisation of long-acting insulin analogue biosimilars to benefit all key stakeholders. Our approach: Multiple approaches including assessing the utilisation, expenditure and prices of insulins, including biosimilar insulin glargine, across multiple continents and countries. Results: There was considerable variation in the use of long-acting insulin analogues as a percentage of all insulins prescribed and dispensed across countries and continents. This ranged from limited use of long-acting insulin analogues among African countries compared to routine funding and use across Europe in view of their perceived benefits. Increasing use was also seen among Asian countries including Bangladesh and India for similar reasons. However, concerns with costs and value limited their use across Africa, Brazil and Pakistan. There was though limited use of biosimilar insulin glargine 100 IU/ml compared with other recent biosimilars especially among European countries and Korea. This was principally driven by small price differences in reality between the originator and biosimilars coupled with increasing use of the patented 300 IU/ml formulation. A number of activities were identified to enhance future biosimilar use. These included only reimbursing biosimilar long-acting insulin analogues, introducing prescribing targets and increasing competition among manufacturers including stimulating local production. Conclusions: There are concerns with the availability and use of insulin glargine biosimilars despite lower costs. This can be addressed by multiple activities.

Integrative Review of Managed Entry Agreements: Chances and Limitations.

BACKGROUND AND OBJECTIVE: Managed entry agreements (MEAs) consist of a set of instruments to reduce the uncertainty and the budget impact of new high-priced medicines; however, there are concerns. There is a need to critically appraise MEAs with their planned introduction in Brazil. Accordingly, the objective of this article is to identify and appraise key attributes and concerns with MEAs among payers and their advisers, with the findings providing critical considerations for Brazil and other high- and middle-income countries. METHODS: An integrative review approach was adopted. This involved a review of MEAs across countries. The review question was 'What are the health technology MEAs that have been applied around the world?' This review was supplemented with studies not retrieved in the search known to the senior-level co-authors including key South American markets. It also involved senior-level decision makers and advisers providing guidance on the potential advantages and disadvantages of MEAs and ways forward. RESULTS: Twenty-five studies were included in the review. Most MEAs included medicines (96.8%), focused on financial arrangements (43%) and included mostly antineoplastic medicines. Most countries kept key information confidential including discounts or had not published such data. Few details were found in the literature regarding South America. Our findings and inputs resulted in both advantages including reimbursement and disadvantages including concerns with data collection for outcome-based schemes. CONCLUSIONS: We are likely to see a growth in MEAs with the continual launch of new high-priced and often complex treatments, coupled with increasing demands on resources. Whilst outcome-based MEAs could be an important tool to improve access to new innovative medicines, there are critical issues to address. Comparing knowledge, experiences, and practices across countries is crucial to guide high- and middle-income countries when designing their future MEAs.

Senescence, apoptosis or autophagy? When a damaged cell must decide its path--a mini-review.

Many features of aging result from the incapacity of cells to adapt to stress conditions. When damage accumulates irreversibly, mitotic cells from renewable tissues rely on either of two mechanisms to avoid replication. They can permanently arrest the cell cycle (cellular senescence) or trigger cell death programs. Apoptosis (self-killing) is the best-described form of programmed cell death, but autophagy (self-eating), which is a lysosomal degradation pathway essential for homeostasis, reportedly contributes to cell death as well. Unlike mitotic cells, postmitotic cells like neurons or cardiomyocytes cannot become senescent since they are already terminally differentiated. The fate of these cells entirely depends on their ability to cope with stress. Autophagy then operates as a major homeostatic mechanism to eliminate damaged organelles, long-lived or aberrant proteins and superfluous portions of the cytoplasm. In this mini-review, we briefly summarize the molecular networks that allow damaged cells either to adapt to stress or to engage in programmed-cell-death pathways.

Enfermedad inflamatoria intestinal en el embarazo: peculiaridades y tratamiento. Revisión bibliográfica / Inflammatory bowel disease in pregnancy: peculiarities and treatment. Review

Resumen ANTECEDENTES: La prevalencia de la enfermedad inflamatoria intestinal en países occidentales se estima en 0.7%. Su relación con el embarazo está en constante estudio y actualización. Esta enfermedad se relaciona con diferentes afecciones obstétricas: prematurez y aumento de teratogenia. La atención médica y el tratamiento suponen un reto durante el embarazo. OBJETIVO: Actualizar los conocimientos acerca de cómo el embarazo modifica el curso de la enfermedad y cómo la enfermedad modifica el curso de aquél, mencionar la seguridad de los tratamientos a las embarazadas y los consensos obstétricos vigentes. METODOLOGÍA: Revisión bibliográfica efectuada en dos bases de datos (PubMed y Embase) con los siguientes criterios de búsqueda (MeSH): "inflammatory bowel disease'' y "pregnancy'' de artículos publicados entre el 2015 y diciembre del 2022, escritos en todas las lenguas: metanálisis, ensayos clínicos, revisiones sistemáticas, narrativas, estudios prospectivos y retrospectivos. RESULTADOS: Se identificaron 345 registros, que luego de la eliminación de los duplicados y otras causas se seleccionaron 30 artículos por su relevancia y novedad. CONCLUSIÓN: La paciente con enfermedad inflamatoria intestinal, en estado de embarazo, debe considerarse de alto riesgo y requerimiento de seguimiento estrecho. La planificación del embarazo es decisiva a fin de optimizar el grado de actividad de la enfermedad y aminorar sus complicaciones. Si bien la mayor parte de los fármacos para su tratamiento se consideran seguros es necesario conocerlos en profundidad.

Abstract BACKGROUND: The prevalence of inflammatory bowel disease is estimated to be 0.7% in western countries. Its association with pregnancy is constantly being studied and updated. This disease is associated with several obstetric conditions: prematurity or increased teratogenicity. Medical care and treatment during pregnancy is a challenge. OBJECTIVE: To update the knowledge on how pregnancy modifies the course of the disease and how the disease modifies the course of the disease, to mention the safety of treatments for pregnant women and the current obstetric consensus. METHOD: Literature search in two databases (PubMed and Embase) with the following search criteria (MeSH): "inflammatory bowel disease" and "pregnancy" of articles published between 2015 and December 2022, written in all languages: meta-analyses, clinical trials, systematic reviews, narratives, prospective and retrospective studies. RESULTS: 345 records were identified and, after elimination of duplicates and other causes, 30 articles were selected for relevance and novelty. CONCLUSION: The pregnant patient with inflammatory bowel disease should be considered high risk and require close follow-up. Pregnancy planning is essential to optimise disease activity and minimise complications. Although most drugs used to treat inflammatory bowel disease.

Tumor de células granulares de vulva: un raro tumor genital benigno / Granular cell tumor of vulva: a rare benign genital tumor

Resumen ANTECEDENTES: El tumor de células granulares de la vulva es poco común y de origen neurogénico. Afecta, principalmente, a mujeres entre 60 y 70 años y es más frecuente en la raza negra. CASO CLÍNICO: Paciente de 63 años, con una lesión vulvar indolora y no pruriginosa, en crecimiento. En la exploración se observó una lesión excrecente de 2.5 cm en la región superior del labio mayor izquierdo, dura, vascularizada y con infiltración a 2 cm de profundidad. No se palparon adenopatías sospechosas. Luego del reporte de la biopsia, sugerente de tumor de células granulares, se practicó una escisión completa, con márgenes libres. El estudio inmunohistoquímico se reportó positivo para CD68, S100 y TFE3 lo que confirmó el diagnóstico. Puesto que el índice proliferativo (Ki67) fue inferior al 5% y los márgenes quirúrgicos estaban libres, no se requirió tratamiento adyuvante. La paciente permanece en seguimiento y sin signos de recidiva. CONCLUSIÓN: Si bien los tumores de células granulares de la vulva son poco comunes y casi siempre benignos, deben incluirse en el diagnóstico diferencial de una tumoración vulvar. La inmunohistoquímica es la herramienta más útil para el diagnóstico preciso y su tratamiento de elección es la escisión local amplia, por su tendencia a la recurrencia local.

Abstract BACKGROUND: Granular cell tumor of the vulva is rare and neurogenic in origin. It mainly affects women between 60 and 70 years of age and is more frequent in black women. CLINICAL CASE: A 63-year-old woman with a painless, non-pruritic, growing vulvar lesion. Examination revealed a 2.5 cm excrescent lesion in the upper region of the left labium majus, hard, vascularized and infiltrated to a depth of 2 cm. No suspicious lymph nodes were palpated. After the biopsy report, suggestive of granular cell tumor, complete excision was performed, with free margins. The immunohistochemical study was positive for CD68, S100 and TFE3 which confirming the diagnosis. Since the proliferative index (Ki67) was less than 5% and the surgical margins were clear, adjuvant treatment was not required. The patient remains in follow-up with no signs of recurrence. CONCLUSION: Although granular cell tumors of the vulva are rare and almost always benign, they should be included in the differential diagnosis of a vulvar tumor. Immunohistochemistry is the most useful tool for accurate diagnosis and their treatment of choice is wide local excision because of their tendency for local recurrence.

Duplicidad intestinal y diagnóstico diferencial prenatal de lesiones quísticas intraabdominales / Intestinal duplication and prenatal differential diagnosis of intra-abdominal cysts

Resumen ANTECEDENTES: Las duplicaciones del aparato digestivo son una variante poco frecuente de malformación congénita. Si bien la mejora de los equipos de ecografía ha aumentado la tasa diagnóstica, solo el 30% se diagnostican antes del nacimiento. El diagnóstico diferencial de lesiones quísticas intraabdominales es amplio e incluye, por ejemplo, a los quistes de ovario, colédoco, mesenterio o pseudoquistes de meconio. El tratamiento es quirúrgico mediante la resección y restauración de la continuidad intestinal. CASO CLÍNICO: Paciente de 32 años, con un embarazo previo y en el segundo trimestre del actual, con sospecha de un quiste de duplicación intestinal. El estudio genético no evidenció anomalía alguna. La lesión, de morfología quística tubular, fue aumentando progresivamente de tamaño conforme avanzaban las semanas de embarazo. En la semana 39 se indicó, por diabetes gestacional insulinodependiente, la inducción del parto. Nació un varón, asintomático, mediante parto eutócico, sin complicaciones. La ecografía abdominal, resonancia magnética nuclear y estudio del tránsito intestinal del periodo neonatal temprano confirmó el diagnóstico prenatal de sospecha. Mediante una laparoscopia exploradora, a las dos semanas de vida se practicó la resección del defecto que se reportó como: duplicación intestinal ileal, sin comunicación con la luz intestinal. El curso posoperatorio fue favorable. CONCLUSIONES: El diagnóstico prenatal de quistes de duplicación en el aparato digestivo está en aumento debido a la mejoría en las técnicas de diagnóstico prenatal. La valoración multidisciplinaria es decisiva para procurar una adecuada vigilancia médica del embarazo y del recién nacido.

Abstract BACKGROUND: Duplications of the digestive tract are a rare variant of congenital malformation that can occur anywhere in the digestive tract. Although improved ultrasound equipment has increased the diagnostic rate, only 30% are diagnosed before birth. The differential diagnosis of intra-abdominal cystic lesions is broad and includes, for example, cysts of the ovary, common bile duct, mesentery or meconium pseudocysts. Treatment is surgical by resection and restoration of intestinal continuity. CLINICAL CASE: 32-year-old patient, with a previous pregnancy and in the second trimester of the current pregnancy, with suspicion of an intestinal duplication cyst. The genetic study did not reveal any abnormality. The lesion, of tubular cystic morphology, progressively increased in size as the weeks of pregnancy progressed. Induction of labour was indicated in week 39 due to insulin-dependent gestational diabetes. An asymptomatic male was born by euthecological delivery, without complications. Abdominal ultrasound, nuclear magnetic resonance imaging and intestinal transit study of the early neonatal period confirmed the suspected prenatal diagnosis. By means of exploratory laparoscopy, at two weeks of life, resection of the defect was performed, which was reported as: ileal intestinal duplication, without communication with the intestinal lumen. The postoperative course was favourable. CONCLUSIONS: Prenatal diagnosis of duplication cysts in the digestive tract is increasing due to improved prenatal diagnostic techniques. Multidisciplinary assessment is crucial to ensure adequate medical surveillance of the pregnancy and the newborn.

Nox2 in regulatory T cells promotes angiotensin II-induced cardiovascular remodeling.

The superoxide-generating enzyme Nox2 contributes to hypertension and cardiovascular remodeling triggered by activation of the renin-angiotensin system. Multiple Nox2-expressing cells are implicated in angiotensin II-induced (Ang II-induced) pathophysiology, but the importance of Nox2 in leukocyte subsets is poorly understood. Here, we investigated the role of Nox2 in T cells, particularly Tregs. Mice globally deficient in Nox2 displayed increased numbers of Tregs in the heart at baseline, whereas Ang II-induced effector T cell (Teff) infiltration was inhibited. To investigate the role of Treg Nox2, we generated a mouse line with CD4-targeted Nox2 deficiency (Nox2fl/flCD4Cre+). These animals showed inhibition of Ang II-induced hypertension and cardiac remodeling related to increased tissue-resident Tregs and reduction in infiltrating Teffs, including Th17 cells. The protection in Nox2fl/flCD4Cre+ mice was reversed by anti-CD25 antibody depletion of Tregs. Mechanistically, Nox2-/y Tregs showed higher in vitro suppression of Teff proliferation than WT Tregs, increased nuclear levels of FoxP3 and NF-κB, and enhanced transcription of CD25, CD39, and CD73. Adoptive transfer of Tregs confirmed that Nox2-deficient cells had greater inhibitory effects on Ang II-induced heart remodeling than WT cells. These results identify a previously unrecognized role of Nox2 in modulating suppression of Tregs, which acts to enhance hypertension and cardiac remodeling.

Evaluación del riesgo de caídas en los adultos mayores, durante el periodo de confinamiento 2020 / Assessment of the risk of falls in the elderly, during the confinement period 2020 / Avaliação do risco de quedas em idosos, durante o período de confinamento de 2020

Los adultos mayores, por naturaleza presentan deterioro progresivo de las capacidades físico-cognitivas, donde se ven afectadas facultades como el equilibrio, la marcha, la fuerza y la movilidad funcional. El confinamiento y distanciamiento social pueden llevar a que estas personas pierdan ciertas rutinas y aumenten en ellos el riesgo de sufrir caídas y lesiones músculo esqueléticas. Objetivo. Determinar el riesgo de caídas en los adultos mayores durante el periodo de confinamiento. Materiales y métodos. Estudio de enfoque cuantitativo, alcance descriptivo, diseño no experimental y de cohorte transversal; muestra poblacional de 42 adultos mayores en la ciudad de Guayaquil, que cumplen con los criterios de inclusión, a quienes se evalúan mediante historia clínica, las pruebas Timed Up & go, Tinetti, Downton y Falls Efficacy. Resultados. Predominio del grupo poblacional de sexo femenino con edades comprendidas entre 80 y 91 años, el Test Timed Up & Go denota que el 76% presentan déficit moderado y variable de la movilidad funcional, el test de Tinetti evidencia un alto riesgo de caídas en 83% de adultos mayores, mientras que las escalas de Downton y Falls Efficacy, muestran que un 50% requiere cuidados específicos y el 48% tienen temor de caer. Conclusiones. El grupo de adultos mayores evaluados muestra una alta predisposición al riesgo de caídas, producto del déficit de la movilidad, alteración del equilibrio y marcha, como respuesta a la falta de actividad física y distanciamiento social generada durante el periodo de confinamiento de marzo a junio 2020.

Older adults, by nature, present progressive deterioration of physical cognitive capacities, where faculties such as balance, gait, strength and functional mobility are affected. Confinement and social distancing can lead to these people losing certain routines and increasing their risk of falls and musculoskeletal injuries. Objective. To determine the risk of falls in the elderly during the confinement period. Materials and methods. Study with a quantitative approach, descriptive scope, non-experimental design and a cross-sectional cohort; The population sample is of 42 older adults in the city of Guayaquil, who meet the inclusion criteria, who are evaluated through a clinical history and the tests, Timed Up & go, Tinetti, Downton and Falls Efficacy. Results. Predominance of the female population group aged between 80 and 91 years, the Timed Up & Go Test denotes that 76% present moderate and variable deficiency of functional mobility, the Tinetti test shows a high risk of falls in 83% of older adults, while the Downton and Falls Efficacy scales show that 50% require specific care and 48% are afraid of falling. Conclusions. The group of older adults evaluated shows a high predisposition to the risk of falls, product of the mobility deficit, alteration of balance and gait, in response to the lack of physical activity and social distancing generated during the confinement period from March to June 2020.

Os adultos mais velhos, por natureza, apresentam deterioração progressiva das capacidades físico-cognitivas, onde faculdades como equilíbrio, marcha, força e mobilidade funcional são afetadas. O confinamento e o distanciamento social podem levar essas pessoas a perder certas rotinas e aumentar o risco de quedas e lesões musculoesqueléticas. Objetivo. Determinar o risco de quedas em idosos durante o período de confinamento. Materiais e métodos. Estudo com abordagem quantitativa, de escopo descritivo, não experimental e com delineamento de coorte transversal; A amostra populacional é composta por 42 idosos na cidade de Guayaquil, que atendem aos critérios de inclusão, que são avaliados por meio de um histórico médico e dos testes de eficácia Timed Up & go, Tinetti, Downton e Falls. Resultados. Predominância da população feminina na faixa etária de 80 a 91 anos, o Teste Timed Up & Go denota que 76% apresentam déficit moderado e variável de mobilidade funcional, o teste de Tinetti mostra alto risco de quedas em 83% dos idosos, enquanto as escalas de Downton e Falls Efficacy mostram que 50% requerem cuidados específicos e 48% têm medo de cair. Conclusões. O grupo de adultos mais velhos avaliados apresenta elevada predisposição ao risco de quedas, produto do déficit de mobilidade, alteração do equilíbrio e marcha, em resposta à inatividade física e distanciamento social gerado durante o período de confinamento de março a junho de 2020.

Retinoic Acid Signaling in B Cells Is Required for the Generation of an Effective T-Independent Immune Response.

Retinoic acid (RA) plays an important role in the balance of inflammation and tolerance in T cells. Furthermore, it has been demonstrated that RA facilitates IgA isotype switching in B cells in vivo. However, it is unclear whether RA has a direct effect on T-independent B cell responses in vivo. To address this question, we generated a mouse model where RA signaling is specifically silenced in the B cell lineage. This was achieved through the overexpression of a dominant negative receptor α for RA (dnRARα) in the B cell lineage. In this model, we found a dramatic reduction in marginal zone (MZ) B cells and accumulation of transitional 2 B cells in the spleen. We also observed a reduction in B1 B cells in the peritoneum with a defect in the T-independent B cell response against 2,4,6-trinitrophenyl. This was not a result of inhibited development of B cells in the bone marrow, but likely the result of both defective expression of S1P1 in MZ B cells and a defect in the development of MZ and B1 B cells. This suggests that RARα expression in B cells is important for B cell frequency in the MZ and peritoneum, which is crucial for the generation of T-independent humoral responses.

Estrategias de enfermería para la prevención de errores programáticos en vacunatorio / Nursing strategies for the prevention of programmatic errors in vaccination

El Programa Nacional de Inmunizaciones (PNI) nace el año 1978 en Chile, considerando dentro de sus objetivos la prevención de la morbilidad, discapacidad y muertes secundarias a enfermedades inmunoprevenibles a lo largo de todo el ciclo vital. Dentro de los eventos asociados al proceso de inmunización y que el PNI contempla desde sus inicios, se encuentran los "Errores Programáticos en vacunación" (EPRO), definidos como eventos relacionados con los aspectos operativos de la vacunación, evitables, que no cumplen con las normas establecidas y que no causaron daño en el paciente. La gestión y prevención de los EPRO son vitales para asegurar la calidad y seguridad en la atención de pacientes durante todo su ciclo vital, debido a que a partir de estos se efectúan medidas correctivas y se puede realizar una evaluación de las razones de su ocurrencia pudiendo así evitar su futura aparición, a través de la elaboración de lineamientos para su prevención. Esta tarea ha sido liderada por los equipos de enfermería desde los inicios del proceso de inmunización en nuestro país y la cual se ha demostrado mediante estrategias como la estandarización de procesos, implementación de pautas de seguridad durante todo el proceso de vacunación, realización de reportes de errores con información detallada y veraz, programas de mejoras continua, evaluación de pautas de calidad de procesos, sistemas de gestión de control de stock, trabajo en equipo y metodologías de comunicación efectivas.

The Expanded Program on Immunization (EPI) in Chile, was born in 1978, considering within its objectives the prevention of morbidity, disability and deaths secondary to immunoprevenible diseases throughout the entire life cycle. Among the risks associated with the immunization process and that the EPI contemplates since its inception, there are the "Programmatic Errors in Vaccination" (EPRO), defined as attitudes or procedures that do not comply with the established norms of vaccination and that alone or in together they can generate serious and fatal adverse events. The management and prevention of events such as EPROs are vital for the assurance of quality and safety in patient care throughout their life cycle, a task that the Nursing team has been responsible for leading since the beginning of the immunization process in our country and which has been demonstrated through strategies such as process standardization, implementation of safety guidelines throughout the vaccination process, reporting of errors with detailed and truthful information, continuous improvement programs, evaluation of quality guidelines of processes, stock control management systems, teamwork and effective communication methodologies.

Activation of the NLRP3 inflammasome in dendritic cells induces IL-1beta-dependent adaptive immunity against tumors.

The therapeutic efficacy of anticancer chemotherapies may depend on dendritic cells (DCs), which present antigens from dying cancer cells to prime tumor-specific interferon-gamma (IFN-gamma)-producing T lymphocytes. Here we show that dying tumor cells release ATP, which then acts on P2X(7) purinergic receptors from DCs and triggers the NOD-like receptor family, pyrin domain containing-3 protein (NLRP3)-dependent caspase-1 activation complex ('inflammasome'), allowing for the secretion of interleukin-1beta (IL-1beta). The priming of IFN-gamma-producing CD8+ T cells by dying tumor cells fails in the absence of a functional IL-1 receptor 1 and in Nlpr3-deficient (Nlrp3(-/-)) or caspase-1-deficient (Casp-1(-/-)) mice unless exogenous IL-1beta is provided. Accordingly, anticancer chemotherapy turned out to be inefficient against tumors established in purinergic receptor P2rx7(-/-) or Nlrp3(-/-) or Casp1(-/-) hosts. Anthracycline-treated individuals with breast cancer carrying a loss-of-function allele of P2RX7 developed metastatic disease more rapidly than individuals bearing the normal allele. These results indicate that the NLRP3 inflammasome links the innate and adaptive immune responses against dying tumor cells.

The interaction between HMGB1 and TLR4 dictates the outcome of anticancer chemotherapy and radiotherapy.

For the last four decades, the treatment of cancer has relied on four treatment modalities, namely surgery, radiotherapy, cytotoxic chemotherapy, and hormonotherapy. Most of these therapies are believed to directly attack and eradicate tumor cells. The emerging concept that cancer is not just a disease of a tissue or an organ but also a host disease relies on evidence of tumor-induced immunosuppression and polymorphisms in genes involved in host protection against tumors. This theory is now gaining new impetus, based on our recent data showing that optimal therapeutic effects require the immunoadjuvant effect of tumor cell death induced by cytotoxic anticancer agents. Here, we show that the release of the high mobility group box 1 protein (HMGB1) by dying tumor cells is mandatory to license host dendritic cells (DCs) to process and present tumor antigens. HMGB1 interacts with Toll-like receptor 4 (TLR4) on DCs, which are selectively involved in the cross-priming of anti-tumor T lymphocytes in vivo. A TLR4 polymorphism that affects the binding of HMGB1 to TLR4 predicts early relapse after anthracycline-based chemotherapy in breast cancer patients. This knowledge may be clinically exploited to predict the immunogenicity and hence the efficacy of chemotherapeutic regimens.

Buthionine sulfoximine increases the toxicity of nifurtimox and benznidazole to Trypanosoma cruzi.

l-Buthionine (S,R)-sulfoximine (BSO) increased the toxicity of nifurtimox and benznidazole toward the epimastigote, trypomastigote, and amastigote forms of Trypanosoma cruzi. BSO at 500 muM decreased total glutathione-derived thiols by 70 to 80% in 48 h. In epimastigotes, 500 muM BSO decreased the concentration of nifurtimox needed to inhibit constant growth of the parasites by 50%, from 14.0 to 9.0 muM, and decreased that of benznidazole from 43.6 to 24.1 muM. The survival of epimastigotes or trypomastigotes treated with nifurtimox or benznidazole, as measured by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) reduction, was significantly decreased by 500 muM BSO. In Vero cells infected with amastigotes, 25 muM BSO was able to potentiate the effect of nifurtimox and benznidazole as measured by the percentage of infected Vero cells multiplied by the average number of intracellular amastigotes (endocytic index). At 0.5 muM nifurtimox, the proportion of Vero cells infected decreased from 27 to 20% and the endocytic index decreased from 2,500 to 980 when 25 muM BSO was added. Similar results were obtained with benznidazole- and BSO-benznidazole-treated cells. This study indicates that potentiation of nifurtimox or benznidazole by BSO could decrease the clinical dose of both drugs and diminish the side effects or the length of therapy.