Seroprevalence of Trypanosoma cruzi in Eight Blood Banks in Mexico.

BACKGROUND: The true prevalence of Chagas disease in Mexico is unknown. However, it has been estimated that 1.1-4 million people are infected with Trypanosoma cruzi, which represents a potential risk for transmission of the disease via contaminated blood. AIM OF THE STUDY: To determine the Chagas disease seroprevalence in donors from eight blood banks in the north of Mexico City, and the northeast of the State of Mexico. STUDY DESIGN AND METHODS: Serum samples from blood donors (n = 515,038) were tested to detect the presence of anti-Trypanosoma cruzi antibodies in eight blood banks. The serologic screening test was performed in each of the blood banks. To confirm the seropositive blood donors, only two out of the eight blood banks used a test with a different principle with the aim of identifying anti-Trypanosoma cruzi antibodies. All tests were validated by the Mexican Institute for Epidemiological Diagnosis and Reference. RESULTS: One thousand two hundred and ten blood donors were seropositive for Trypanosoma cruzi, which represents a 0.23% seroprevalence (95% CI 0.22-0.25%). Of the seropositive blood donors, 97.03 % resided in the northeast area of the State of Mexico, Mexico City, and southern part of the State of Hidalgo. CONCLUSIONS: Active transmission of Chagas disease may be occurring in non-endemic regions in the northeast of the State of Mexico.

Manejo de las hemorragias en el enfermo oncológico avanzado / Management of bleeding in the advanced oncologic patient

Hemorrhage in the advanced or terminal cáncer patient represents a distressing and complex situation in the palliative care setting, potentially leading to death of the patient due to massive loss of circulating volume. Although it is a relatively rare event, it is an urgent and distressing clinical problem for the patient, family and health care providers(1). Its incidence in patients with advanced cancer varies from 6% to 14% in solid tumors, being higher in head and neck cancers and up to 30% in hematological neoplasms[],[]. Among the risk factors are those related to the tumor, treatments, systemic factors, among others, and it may present as an acute catastrophic event, severe episodic bleeding or continuous low volume exudation[],[]. Available recom- mendations for the management of terminal hemorrhage are based on: identificaron of high-risk patients, early establishment of general supportive measures, local and systemic measures and the use of emergency or crisis medications[]. Treatment should be individualized, including interventions on the underlying causes and on the risk-benefit ratio of interventions for mitigation or control of bleeding, within the context of survival expectations. In the palliative patient at the end of life, decision making should be based on providing adequate symptomatic control, comfort measures and improving quality of life

La hemorragia en el paciente oncológico avanzado o también denominada terminal representa una situación angustiante y compleja en el ámbito de los cuidados paliativos, que potencialmente puede generar la muerte del paciente debido a la perdida masiva de volumen circulante. Aunque es un evento relativamente raro, es un problema clínico urgente y angustiante para el paciente, su familia y proveedores de salud[]. Su incidencia en pacientes con cáncer avanzado varia del 6% al 14%, en tumores sólidos, siendo más alta en canceres de cabeza y cuello y hasta el 30% en neoplasias hematológicas[],[]. Dentro de los factores de riesgo se encuentran aquellos relacionados con el tumor, los tratamientos, factores sistémicos entre otros, y puede presentarse como un evento catastrófico agudo, hemorragias episódicas graves o exudación continua de bajo volumen[],[]. Las recomendaciones disponibles para el manejo de la hemorragia terminal se basan en: la identificación de pacientes con alto riesgo, la instauración temprana de medidas generales de soporte, medidas locales y sistémicas y el uso de medicamentos de emergencia o crisis[]. El tratamiento debe ser individualizado, incluyendo las intervenciones en las causas subyacentes y en la relación riesgo-beneficio de las intervenciones para la mitigación o control de la hemorragia, dentro del contexto de las expectativas de la supervivencia. En el paciente paliativo al final de la vida la toma de decisiones debe tener como pilar: brindar un adecuado control sintomático, medidas de confort y mejorar la calidad de vida

Fiebre de origen oscuro como manifestación de lupus eritematoso sistémico / Fever of unknown origin as manifestation of systemic lupus erythematosus

Resumen: La fiebre de origen oscuro se caracteriza por un espectro clínico de pacientes que consultan por padecer fiebre como manifestación única o predominante, mayor o igual a 38.3ºC, de más de tres semanas de evolución y en quienes los resultados de la evaluación clínica y estudios paraclínicos iniciales no han identificado su causa. Se han agrupado cinco categorías que engloban las causas de la fiebre de origen oscuro, entre las que se encuentran las enfermedades infecciosas, neoplásicas, inflamatorias no infecciosas, misceláneas y de origen desconocido. El lupus eritematoso sistémico es una enfermedad de tipo autoinmunitario que afecta el tejido conectivo y tiene amplio rango de manifestaciones clínicas, entre las que destacan al inicio poliartritis, úlceras mucocutáneas y el eritema malar; el lupus eritematoso sistémico es una de las causas inflamatorias no infecciosas de fiebre de origen oscuro. Se comunica el caso clínico de una paciente de 51 años de edad, quien consultó al servicio de Medicina interna, por padecer un cuadro clínico de 30 días de evolución, con fiebre intermitente, diaria y cuantificada entre 38.5 y 39°C, asociada con pérdida significativa de peso; en quien se diagnosticó por hallazgos clínicos y paraclínicos lupus eritematoso sistémico, fue tratada con hidroxicloroquina y prednisolona, con desaparición de la fiebre y mejoría del estado general.

Abstract: Fever of unknown origin is defined as a clinical spectrum of patients who consulted for presenting fever as a single or predominant manifestation, greater or equal to 38.3ºC, more than 3 weeks of evolution, and in whom clinical evaluation results and initial paraclinical studies have not identified its cause. Five categories group the causes of fever of unknown origin which include infectious, neoplastic, inflammatory non-infectious, miscellaneous and of unknown origin. Systemic lupus erythematosus is an autoimmune disease that affects connective tissue and has a wide range of clinical manifestations, among which the presence of polyarthritis, mucocutaneous ulcers and malar erythema stand out at the beginning; systemic lupus erythematosus is one of the non-infectious inflammatory causes of fever of unknown origin. A clinical case report is made, of a 51-year-old woman, who consulted to Internal Medicine, with a clinical picture of 30 days of evolution, with intermittent fever, daily and quantified between 38.5 and 39ºC, associated with significant weight loss; to which it was diagnosed by clinical and paraclinical findings systemic lupus erythematosus, treated with hydroxychloroquine and prednisolone, achieving disappearance of the fever and improvement of the general state of the patient.

Orthodontic fixed retainers: a systematic review / Retenedores fijos en ortodoncia: revisión sistemática

ABSTRACT Introduction: the objective of this study was to evaluate the periodontal effects of fixed retainers in the long term. Methods: a search in electronic databases (PubMed, Cochrane Library, Science Direct, Embase, ProQuest, Ebsco, Biomed Central, Medline, Lilacs, and Google Scholar) and a manual search with no language restrictions. The inclusion criteria were: randomized clinical trials and meta-analysis, prospective and retrospective studies, studies in humans, clinical and radiographical studies evaluating the periodontium, performed during the 1987-2014 period, up to 10 years of follow-up. Four authors extracted data from the selected studies independently. Results: after applying the inclusion criteria, we selected 4 studies in which a total of 405 patients were evaluated. All the studies were longitudinal and retrospective. There was a greater prevalence of gingival recessions, especially in mandibular incisors, which are more vulnerable. There were no significant changes in terms of alveolar bone index or calculus index. The survival rate of fixed retainers was 50% or higher. Due to the heterogeneity of the selected studies, including difference in study population, differences in methods to assess the intervention, and follow-up periods, it was impossible to quantify the variables to perform a meta-analysis. Conclusions: the selected studies had a middle level of evidence. The greatest gingival recessions occurred with the use of fixed retainers in a long time; however, there is no alteration of the alveolar bone level. The studies recommend encouraging patients to maintain good oral hygiene. The findings of this review should be cautiously taken due to the resulting level of evidence, and the general recommendation for clinicians is that, in the long run, these retainers appear to be safe to maintain the alignment of mandibular incisors, although more studies with greater scientific rigor are required. There were no conflicts of interest and this study did not have any kind of financial support.

RESUMEN. Introducción: el objetivo del presente estudio consistió en evaluar los efectos periodontales de los retenedores fijos a largo plazo. Métodos: se realizó una búsqueda en bases de datos electrónicas (PubMed, Cochrane Library, Science Direct, Embase, ProQuest, Ebsco, Biomed Central, Medline, Lilacs y Google Scholar) y una búsqueda manual sin restricción de lenguaje. Los criterios de inclusión fueron: ensayos clínicos aleatorizados y metaanálisis, estudios prospectivos y retrospectivos, estudios en humanos, estudios en los que se evaluara clínica y radiográficamente el periodonto, periodo comprendido entre 1987 y 2014, seguimiento hasta 10 años. Cuatro autores extrajeron independientemente los datos de los estudios seleccionados. Resultados: después de aplicar los criterios de inclusión, se seleccionaron 4 estudios en los que se evaluaron un total de 405 pacientes. Todos los estudios fueron longitudinales retrospectivos. Se encontró una mayor prevalencia de recesiones gingivales, especialmente de los incisivos mandibulares, que son más vulnerables. No mostraron cambios significativos ni el índice de hueso alveolar ni el índice de cálculo. La tasa de supervivencia de los retenedores fijos fue mayor del 50%. Debido a la heterogeneidad de los estudios seleccionados, entre los cuales se encuentra la diferencia en la población de estudio, diferencias en los métodos para evaluar la intervención y el tiempo de seguimiento, fue imposible cuantificar las variables para realizar un metaanálisis. Conclusiones: los estudios seleccionados tuvieron un nivel de evidencia medio. Se presentan mayores recesiones gingivales con el uso de los retenedores fijos a largo plazo; sin embargo, no hay alteración del nivel óseo alveolar. Los estudios recomiendan incentivar al paciente para que mantenga una buena higiene oral. Los resultados de esta revisión se deben tomar con cautela por el nivel de evidencia que arrojaron, y la recomendación general para el clínico es que, a largo plazo, estos retenedores parecen ser seguros para mantener el alineamiento de incisivos mandibulares, aunque se requieren más estudios con mayor rigor científico. No hubo conflictos de intereses y la investigación no contó con ningún tipo de financiamiento.

Effects of shiga toxin 2 on cellular regeneration mechanisms in primary and three-dimensional cultures of human renal tubular epithelial cells.

Shiga toxin (Stx)-producing Escherichia coli (STEC) causes post-diarrheal Hemolytic Uremic Syndrome (HUS), which is one of the most common causes of acute renal failure in children in Argentine. The aim of the present work was to study the effects of Shiga toxin type 2 (Stx2) on regenerative mechanisms of primary cultures of human cortical renal tubular epithelial cells (HRTEC) and three-dimensional (3D) cultures of HRTEC. Primary cultures of HRTEC were able to develop tubular structures when grown in matrigel, which showed epithelial cells surrounding a central lumen resembling the original renal tubules. Exposure to Stx2 inhibited tubulogenesis in 3D-HRTEC cultures. Moreover, a significant increase in apoptosis, and decrease in cell proliferation was observed in tubular structures of 3D-HRTEC exposed to Stx2. A significant reduction in cell migration and vimentin expression levels was observed in HRTEC primary cultures exposed to Stx2, demonstrating that the holotoxin affected HRTEC dedifferentiation. Furthermore, a decreased number of cells expressing CD133 progenitor marker was found in HRTEC cultures treated with Stx2. The CD133 positive cells also expressed the Stx receptor globotriaosylceramide, which may explain their sensitivity to Stx2. In conclusion, Stx2 affects the regenerative processes of human renal tubular epithelial cells in vitro, by inhibiting cell dedifferentiation mechanisms, as well as tubules restoration. The development of 3D-HRTEC cultures that resemble original human renal proximal tubules is a novel in vitro model to study renal epithelial repair mechanisms after injury.

Effects of Escherichia coli subtilase cytotoxin and Shiga toxin 2 on primary cultures of human renal tubular epithelial cells.

Shiga toxin (Stx)-producing Escherichia coli (STEC) cause post-diarrhea Hemolytic Uremic Syndrome (HUS), which is the most common cause of acute renal failure in children in many parts of the world. Several non-O157 STEC strains also produce Subtilase cytotoxin (SubAB) that may contribute to HUS pathogenesis. The aim of the present work was to examine the cytotoxic effects of SubAB on primary cultures of human cortical renal tubular epithelial cells (HRTEC) and compare its effects with those produced by Shiga toxin type 2 (Stx2), in order to evaluate their contribution to renal injury in HUS. For this purpose, cell viability, proliferation rate, and apoptosis were assayed on HRTEC incubated with SubAB and/or Stx2 toxins. SubAB significantly reduced cell viability and cell proliferation rate, as well as stimulating cell apoptosis in HRTEC cultures in a time dependent manner. However, HRTEC cultures were significantly more sensitive to the cytotoxic effects of Stx2 than those produced by SubAB. No synergism was observed when HRTEC were co-incubated with both SubAB and Stx2. When HRTEC were incubated with the inactive SubAA272B toxin, results were similar to those in untreated control cells. Similar stimulation of apoptosis was observed in Vero cells incubated with SubAB or/and Stx2, compared to HRTEC. In conclusion, primary cultures of HRTEC are significantly sensitive to the cytotoxic effects of SubAB, although, in a lesser extent compared to Stx2.

How to Attain an Ultralow Interfacial Tension and a Three-Phase Behavior with a Surfactant Formulation for Enhanced Oil Recovery: A Review. Part 2. Performance Improvement Trends from Winsor's Premise to Currently Proposed Inter- and Intra-Molecular Mixtures.

The minimum interfacial tension occurrence along a formulation scan at the so-called optimum formulation is discussed to be related to the interfacial curvature. The attained minimum tension is inversely proportional to the domain size of the bicontinuous microemulsion and to the interfacial layer rigidity, but no accurate prediction is available. The data from a very simple ternary system made of pure products accurately follows the correlation for optimum formulation, and exhibit a linear relationship between the performance index as the logarithm of the minimum tension at optimum, and the formulation variables. This relation is probably too simple when the number of variables is increased as in practical cases. The review of published data for more realistic systems proposed for enhanced oil recovery over the past 30 years indicates a general guidelines following Winsor's basic studies concerning the surfactant-oil-water interfacial interactions. It is well known that the major performance benefits are achieved by blending amphiphilic species at the interface as intermolecular or intramolecular mixtures, sometimes in extremely complex formulations. The complexity is such that a good knowledge of the possible trends and an experienced practical know-how to avoid trial and error are important for the practitioner in enhanced oil recovery.

Using emulsion inversion in industrial processes.

Emulsion inversion is a complex phenomenon, often perceived as an instability that is essentially uncontrollable, although many industrial processes make use of it. A research effort that started 2 decades ago has provided the two-dimensional and three-dimensional description, the categorization and the theoretical interpretation of the different kinds of emulsion inversion. A clear-cut phenomenological approach is currently available for understanding its characteristics, the factors that influence it and control it, the importance of fine-tuning the emulsification protocol, and the crucial occurrence of organized structures such as liquid crystals or multiple emulsions. The current know-how is used to analyze some industrial processes involving emulsion inversion, e.g. the attainment of a fine nutrient or cosmetic emulsion by temperature or formulation-induced transitional inversion, the preparation of a silicone oil emulsion by catastrophic phase inversion, the manufacture of a viscous polymer latex by combined inversion and the spontaneous but enigmatic inversion of emulsions used in metal working operations such as lathing or lamination.