Intravitreal methotrexate in type B lymphoblastic leukemia-Case Report.

Leukemia is a common neoplasia that, in its progress, can have ocular involvement due to direct infiltration or secondary to hematological alterations typical of the disease. These findings are consistent with an involvement of the central nervous system and are thus related to the prognosis. Despite the existing systemic therapies, there needs to be more literature that shows the treatment in the ocular involvement of this disease. A case report of a child with ocular involvement due to treatment-refractory acute lymphoblastic leukemia, successfully managed with intravitreal methotrexate, is presented.

Polimorfismo de proteína 5, 10-metilentetrahidrofolatoreductasa en población venezolana / Polymorphisms proteína 5, 10-metilentetrahidrofolatoreductasa in venezuelan people

El folato es un miembro del grupo de la vitamina B y está relacionado con enfermedades crónicas como anemia megaloblástica, enfermedad cardiovascular, cáncer, disfunción cognitiva y riesgo de defectos del tubo neural. La proteína 5,10-metilentetrahidrofolato reductasa (MTHFR) juega un papel clave en el metabolismo del folato mediante la síntesis de nucleótidos y reacciones de metilación. El gen MTHFR se encuentra en el cromosoma 1 (1p36.3), y se han descrito dos alelos comunes, el alelo C677T (termolábil) y el alelo A1298C.El objetivo de este estudio es evaluar la distribución de los polimorfismos genéticos en MTHFR C677T y A1298C en la población venezolana. METODOS: estudio de tipo transversal, descriptivo, experimental y correlacional Las muestras de sangre se colectaron en 314 donantes no emparentados y sanos de la población. Los polimorfismos de un solo nucleótido(SNP) MTHFR 677C>T y 1298A>C se analizaron mediante polimorfismo de longitud de fragmento de restricción de reacción en cadena de polimerasa (PCR-RFLP). El desequilibrio de ligamiento (LD) entre pares de SNP se calculó mediante la prueba X. usando Prism 5 (GraphPad software, Inc). RESULTADOS: Encontramos mayor frecuencia genotípica de heterocigotos para el polimorfismo MTHFR C677T en la población general venezolana, con excepción del grupo caucásico. El polimorfismo MTHFR A1298C en el 70%de la población de estudio es homocigoto de tipo salvaje, encontrándose una baja frecuencia de homocigoto mutado. CONCLUSIONES: Se encontraron diferencias significativas entre grupos étnicos, destacando la importancia del genotipado racial de estos polimorfismos en la población venezolana(AU)

Folate is a member of the vitamin B and it has also been indicated that may be related to chronic diseases such as megaloblastic anemia, cardiovascular disease, cognitive dysfunction and risk of neural tube. Methylenetetrahydro folatereductase (MTHFR) is a key enzyme of folate pathway by nucleotide synthesis and methylation reactions. Several polymorphisms were reported in MTHFR gene but C677Tand A1298 polymorphism are most studied and these have been reported to be risk factor for several diseases/disorders. The present study was designed to determine the frequency of MTHFR polymorphisms in Venezuelan healthy population. METHODS: The blood samples were collected from 314 unrelated and healthy donors from population. Both the MTHFR 677C>T and 1298A>C single nucleotide polymorphisms (SNPs) were analyzed by Polymerase chainreaction-restriction fragment length polymorphism (PCR-RFLP). Linkage disequilibrium (LD) between pair of SNPs was calculated through the .. test using Prism 5 (GraphPad sftoware, Inc). RESULTS: We find higher genotypic frequency of heterozygotes for the MTHFR C677T polymorphism in the Venezuelan general population, with the exception of the Caucasian group. MTHFR A1298C polymorphism in 70%of the study population is homozygous wild type, finding alow frequency of homozygous mutated. CONCLUSIONS: Significant differences between ethnic groups were found,highlighting the importance of racial genotyping of these polymorphisms in the Venezuelan population(AU)

Chitosan nanoparticles loading oxaliplatin as a mucoadhesive topical treatment of oral tumors: Iontophoresis further enhances drug delivery ex vivo.

Tumors located in the oral mucosa are challenging to treat since surgery can lead to aesthetic, speech, and salivation problems, radiotherapy alone is often ineffective, and systemic chemotherapy brings meaningful side effects to the patient. Here, we proposed to develop mucoadhesive chitosan nanoparticles entrapping the chemotherapeutic oxaliplatin (OXPt) and to evaluate ex vivo its penetration in porcine mucosa under both passive and iontophoretic topical treatments. OXPt-loaded chitosan nanoparticles presented a small hydrodynamic size (188 ± 20 nm), narrow distribution (PDI of 0.28 ± 0.02) and positive zeta potential (+44.8 ± 2.8 mV). These nanoparticles provided a "burst effect" on drug release followed by a longer-term controlled release. When applied to the oral mucosa, the chitosan nanoparticles increased 3-fold drug penetration, and this rate was maintained even when the mucosa was "washed" with a buffer to mimic salivation. Iontophoresis doubled the amount of OXPt transported to the mucosa. These amounts exceeded the dose required to cause cell death of an oral tumor cell line. Besides, chitosan nanoparticles increased the rate of cells that entered into apoptosis. In summary, this study points to the feasibility of topical therapy with chitosan nanoparticles, potentialized by the application of iontophoresis, to treat oral tumors.

Causas del desprendimiento de retina y el desenlace visual final en menores de 18 años en el Hospital San Vicente Fundación / Causes of retinal detachment and visual outcome in children under 18 years old treated at Hospital Universitario de San Vicente Fundación

RESUMEN Objetivo: caracterizar las causas del desprendimiento de retina y determinar la agudeza visual final en menores de 18 años en el Hospital San Vicente Fundación entre 2012 y 2017. Metodología: se realizó un análisis retrospectivo de historias clínicas de pacientes con diagnóstico de desprendimiento de retina confirmado por examen oftalmológico o ecografía, se incluyeron pacientes menores de 18 años que ingresaron al Hospital San Vicente Fundación entre 2012 y 2017 para identificar las causas del desprendimiento de retina y la agudeza visual final. Resultados: se analizaron 51 historias clínicas: 28 hombres y 23 mujeres, 39,1 % ocurrieron en menores de 1 año y no se encontró desprendimiento de retina por encima de los 14 años. Las causas se establecieron como retinopatía de la prematuridad 23,5 %, trauma ocular 21,6 %, retinoblastoma 9,8 %, toxoplasmosis congénita 7,8 %, toxocara 7,8 %, entre otras, no se encontró causa en 3,9 % de los pacientes. En 50 ojos de 41 pacientes se determinó la agudeza visual final, de los cuales 47 (94 %) quedaron con agudeza visual peor o igual a 20/200 y 3 ojos con agudeza visual de 20/40 o mejor. Discusión: el desprendimiento de retina es infrecuente en los niños, sin embargo, sus causas y desenlaces son más devastadores que en los adultos. En nuestro medio las principales causas son la retinopatía de la prematuridad, el trauma, el retinoblastoma y las infecciones parasitarias. Diferente a los adultos, en los niños se requiere una evaluación más cuidadosa y un umbral de sospecha más bajo para considerar enfermedades potencialmente mortales.

SUMMARY Objective: To characterize the causes of retinal detachment and to determinate the visual outcome in children younger than 18 years old evaluated at San Vicente Fundación Hospital between 2012 and 2017. Methodology: We performed a retrospective analysis of medical records of patients with a diagnosis of retinal detachment confirmed by ophthalmological examination or ultrasound scan. Patients under 18 years old admitted to San Vicente Fundación Hospital between 2012 and 2017 were included to identify the causes of retinal detachment and the final visual acuity. Results: 51 clinical histories were analyzed: 28 men and 23 women; 39.1% occurred in children under 1 year old, and no retinal detachment was found above 14 years old. The causes were established as: retinopathy of prematurity 23.5%, ocular trauma 21.6%, retinoblastoma 9.8%, congenital toxoplasmosis 7.8%, toxocara 7.8%, among others. The cause was not found in 3.9% of patients. In 50 eyes of 41 patients, the final visual acuity was determined, of which 47 (94%) had visual acuity equal or worse to 20/200 and 3 eyes with better corrected visual acuity of 20/40 or better. Discussion: Retinal detachment is infrequent in children; however, its causes and outcomes are more devastating than in adults. In our environment, the main causes are retinopathy of prematurity, trauma, retinoblastoma and parasitic infections; unlike adults, children require a more careful assessment and a lower threshold of suspicion to consider life-threatening diseases.

Aberrant levels of SUV39H1 and SUV39H2 methyltransferase are associated with genomic instability in chronic lymphocytic leukemia.

Chromosomal alterations are commonly detected in patients with chronic lymphocytic leukemia (CLL) and impact disease pathogenesis, prognosis, and progression. Telomerase expression (hTERT), its activity and the telomere length are other important predictors of survival and multiple outcomes in CLL. SUV39H and SUV420H enzymes are histone methyltransferases (HMTases) involved in several cellular processes, including regulation of telomere length, heterochromatin organization, and genome stability. Here, we investigated whether SUV39H1, SUV39H2, SUV420H1, SUV420H2, and hTERT are associated with genomic instability of CLL. SUV39H (1/2), SUV420H (1/2), and hTERT expression was determined in 59 CLL samples by real time PCR. In addition, ZAP-70 protein expression was evaluated by Flow Cytometry and patients' karyotype was defined by Cytogenetic Analysis. Low expression of SUV39H1 was associated with the acquisition of altered and complex karyotypes. Conversely, high expression of SUV39H2 correlated with cytogenetic abnormalities in CLL patients. The pattern of karyotypic alterations differed in samples with detectable or undetectable hTERT expression. Furthermore, hTERT expression in CLL showed a correlation with transcript levels of SUV39H2, which, in part, can explain the association between SUV39H2 expression and cytogenetic abnormalities. Moreover, SUV39H1 correlated with SUV420H1 expression while SUV420H2 was associated with all other investigated HMTases. Our data show that the differential expression of SUV39H1 and SUV39H2 is associated with genomic instability and that the modulation of these HMTases can be an attractive approach to prevent CLL evolution. Environ. Mol. Mutagen. 58:654-661, 2017. © 2017 Wiley Periodicals, Inc.

Adenosine production: a common path for mesenchymal stem-cell and regulatory T-cell-mediated immunosuppression.

Adenosine is an important molecule that exerts control on the immune system, by signaling through receptors lying on the surface of immune cells. This nucleotide is produced, in part, by the action of the ectoenzymes CD39 and CD73. Interestingly, these proteins are expressed on the cell surface of regulatory T-cells (Tregs) and mesenchymal stromal cells (MSCs)-two cell populations that have emerged as potential therapeutic tools in the field of cell therapy. In fact, the production of adenosine constitutes a mechanism used by both cell types to control the immune response. Recently, great scientific progress was obtained regarding the role of adenosine in the inflammatory environment. In this context, the present review focuses on the advances related to the impact of adenosine production over the immune modulatory activity of Tregs and MSCs, and how this nucleotide controls the biological functions of these cells. Finally, we mention the main challenges and hurdles to bring such molecule to clinical settings.

Comparação de dois métodos de colheita de medula óssea de equinos e de dois meios de diluição para o isolamento de células mononucleares / Comparison of two methods of equine bone marrow aspiration and two solutions for mononuclear cell isolation

O objetivo do presente estudo foi avaliar a concentração e viabilidade da fração de células mononucleares (FCM) a partir de diferentes técnicas de colheita e processamento de medula óssea (MO) em equinos. Foram avaliados cinco equinos adultos, hígidos e sem raça definida. Obtiveram-se frações de medula óssea (MO) do osso esterno, de acordo com dois protocolos: na colheita A, utilizou-se 10mL de solução de heparina dentro da seringa e em seguida, aspirou-se a MO; na colheita B, 10mL de solução de heparina foi injetada na MO e a aspiração foi realizada após 20 segundos. Todos os animais foram submetidos aos dois protocolos de colheitas, realizadas em sequência, sem intervalo entre os dois procedimentos. Após isolamento da fração de células mononucleares (FCM), das amostras de MO obtidas nas colheitas A e B, cada amostra foi dividida em dois tubos, um contendo solução de DMEM e outro contendo PBS. Assim, alternando-se o tipo de colheita e a solução diluidora, obteve-se quatro tubos de amostras por animal. Os tubos foram centrifugados e os sedimentos foram homogeneizados nos respectivos meios obtendo-se o volume final de 100μL. Realizou-se determinação da concentração e viabilidade celular, obtendo-se as concentrações médias de FCM. Para ambos os meios de diluição, a colheita B apresentou valor numérico maior em comparação à colheita A, porém não foi significativo (p>0,05). Atribui-se tal tendência à menor ocorrência de coagulação da MO no momento da colheita B, sugerindo-se melhor aproveitamento da FCM. Não houve diferença (p>0,05) entre os meios DMEM ou PBS, indicando que os mesmos não alteraram a viabilidade celular. Os protocolos utilizados para colheita de MO e separação da FCM se mostraram eficientes, para o uso em terapia celular em equinos.

The aim of this study was to evaluate mononuclear cells fraction (MCF) concentration and viability from different techniques of bone marrow (BM) aspiration and processing in horses. Five adult horses, healthy and of unknown breed were evaluated. BM was obtained from sternum bone, according two protocols: in aspiration A, 10mL of heparin solution was used inside the syringe and BM was aspirated; in aspiration B, 10mL of heparin solution was injected into the BM, and aspiration was done after 20 seconds. All the animals were submitted by both protocols realized in sequence, without a gap between the procedures. After MCF isolation, of BM samples obtained from A and B aspiration, each sample was divided into two tubes; one contained DMEM solution and the other with PBS solution. Therefore, interchanging the aspiration protocol and the dilution solution, four sample tubes were obtained for each horse. The tubes were centrifuged and the pellet was homogenized with the respectively solution to obtain the final volume of 100μL. Cellular concentration and viability were determined to obtain the FCM medium concentration. For both solutions, the aspiration B had higher numeric values comparing with aspiration A; however, it was not significant (p>0.05). This tendency is attribute for the less BM coagulation observed in the aspiration B, suggesting greater improvement of MCF. No difference (p>0.05) was found between DMEM and PBS solution, indicating that both do not alter the cell viability. The protocols used for BM aspiration and MCF isolation were efficient for application in equine cellular therapy.

LL-37 boosts immunosuppressive function of placenta-derived mesenchymal stromal cells.

BACKGROUND: Although promising for graft-versus-host disease (GvHD) treatment, MSC therapy still faces important challenges. For instance, increasing MSC migratory capacity as well as potentializing immune response suppression are of interest. For GvHD management, preventing opportunistic infections is also a valuable strategy, since immunocompromised patients are easy targets for infections. LL-37 is a host defense peptide (HDP) that has been deeply investigated due to its immunomodulatory function. In this scenario, the combination of MSC and LL-37 may result in a robust combination to be clinically used. METHODS: In the present study, the effects of LL-37 upon the proliferation and migratory capacity of human placenta-derived MSCs (pMSCs) were assessed by MTT and wound scratch assays. The influence of LL-37 over the immunosuppressive function of pMSCs was then investigated using CFSE cell division kit. Flow cytometry and real-time PCR were used to investigate the molecular mechanisms involved in the effects observed. RESULTS: LL-37 had no detrimental effects over MSC proliferation and viability, as assessed by MTT assay. Moreover, the peptide promoted increased migratory behavior of pMSCs and enhanced their immunomodulatory function over activated human PBMCs. Strikingly, our data shows that LL-37 treatment leads to increased TLR3 levels, as shown by flow cytometry, and to an increased expression of factors classically related to immunosuppression, namely IDO, IL-10, TGF-ß, IL-6, and IL-1ß. CONCLUSIONS: Taken together, our observations may serve as groundwork for the development of new therapeutic strategies based on the combined use of LL-37 and MSCs, which may provide patients not only with an enhanced immunosuppression regime, but also with an agent to prevent opportunistic infections.

[Hemostasis alterations in sickle cell syndrome]. / Alteraciones de la hemostasia en el síndrome drepanocítico.

Sickle cell syndrome (SCS) includes a group of congenital hemolytic anemias associated to the presence of hemoglobin S, which is characterized by acute pain episodes and progressive damage of different organs. Some patients with sickle cell syndrome have shown, when compared with healthy individuals, an increased risk of presenting stroke, pulmonary hypertension, avascular necrosis of joints, acute chest syndrome and pregnancy complications, associated to a hypercoagulable state induced by alterations in different components of hemostasis, such as changes that include activation of the endothelium, platelet activity, coagulation and fibrinolytic systems. This paper compiles hemostasis disorders, associated with thrombotic manifestations, reported until now in sickle cell syndrom. These patients have an increase in activation markers of the coagulation system, such as prothrombin fragment 1.2, thrombin-antithrombin complex, etc., depletion of natural anticoagulant proteins, abnormal activation of the fibrinolytic system and increased tissue factor expression. Similarly, abnormal expression of glycoproteins and increased adhesion and platelet aggregation have been reported. All these alterations produce a hypercoagulable state, which induces, among other things, the appearance of thrombotic complications. In view of the importance of controlling the different complications that can occur in patients with sickle cell syndrome, we recommend the implementation, in diagnosis and monitoring studies, of the evaluation of the different components of the hemostatic system, identifying alterations at an early stage and applying effective treatments to prevent thrombotic complications.

Alteraciones de la hemostasia en el síndrome drepanocítico / Hemostasis alterations in sickle cell syndrome

El síndrome drepanocítico (SD) comprende un grupo de anemias hemolíticas hereditarias de tipo multisistémico asociadas a la hemoglobina S. Los pacientes que padecen este síndrome tienen un mayor riesgo, en comparación con individuos sanos, de presentar accidentes cerebrovasculares, hipertensión pulmonar, necrosis avascular de articulaciones, síndrome torácico agudo y complicaciones durante el embarazo, asociados a un estado de hipercoagulabilidad inducido por alteraciones en los diferentes componentes de la hemostasia, que incluyen la activación del endotelio y de los sistemas plaquetario, de la coagulación y de la fibrinólisis. Esta revisión resume las alteraciones en la hemostasia reportadas en los pacientes con SD, en los cuales se ha demostrado: mayor interacción de células endoteliales con leucocitos, hematíes y plaquetas; aumento de la expresión de proteínas de adhesión, como el factor von Willebrand y sus multímeros de alto peso molecular; aumento de la adhesión y la agregación plaquetaria y de la expresión de proteínas en sus membranas. En el sistema de coagulación se ha detectado aumento en la expresión del factor tisular (FT) en micropartículas derivadas de diferentes células, aumento de marcadores de activación de este sistema, entre estos los fragmentos 1.2 de la protrombina y los complejos trombina-antitrombina y una disminución de las proteínas C y S que actúan como anti-coagulantes. Adicionalmente, se han encontrado aumentados los marcadores de activación del sistema fibrinolítico como los dímeros D y los complejos plasmina/antiplasmina. Todas estas manifestaciones favorecen la aparición de complicaciones trombóticas, implicadas en el deterioro de la calidad de vida de los pacientes. Se recomienda implementar en el diagnóstico y seguimiento de esta enfermedad, la determinación de variables del sistema hemostático, con el fin de identificar alteraciones en etapas tempranas y aplicar terapias que puedan prevenir complicaciones trombóticas.

Sickle cell syndrome (SCS) includes a group of congenital hemolytic anemias associated to the presence of hemoglobin S, which is characterized by acute pain episodes and progressive damage of different organs. Some patients with sickle cell syndrome have shown, when compared with healthy individuals, an increased risk of presenting stroke, pulmonary hypertension, avascular necrosis of joints, acute chest syndrome and pregnancy complications, associated to a hypercoagulable state induced by alterations in different components of hemostasis, such as changes that include activation of the endothelium, platelet activity, coagulation and fibrinolytic systems. This paper compiles hemostasis disorders, associated with thrombotic manifestations, reported until now in sickle cell syndrom. These patients have an increase in activation markers of the coagulation system, such as prothrombin fragment 1.2, thrombin-antithrombin complex, etc., depletion of natural anticoagulant proteins, abnormal activation of the fibrinolytic system and increased tissue factor expression. Similarly, abnormal expression of glycoproteins and increased adhesion and platelet aggregation have been reported. All these alterations produce a hypercoagulable state, which induces, among other things, the appearance of thrombotic complications. In view of the importance of controlling the different complications that can occur in patients with sickle cell syndrome, we recommend the implementation, in diagnosis and monitoring studies, of the evaluation of the different components of the hemostatic system, identifying alterations at an early stage and applying effective treatments to prevent thrombotic complications.

Estrabismo y ambliopía, conceptos básicos para el médico de atención primaria / Estrabismo and amblyopia, basic concepts to the physician in primary attention

El estrabismo y la ambliopía son patologías relativamente frecuentes en la población general. La ambliopía constituye la causa principal de disminución de visión unilateral. Existen diferentes tipos de estrabismo mientras que la ambliopía se debe únicamente a tres mecanismos fisiopatológicos. El objetivo de este artículo es brindar al médico de atención primaria y al estudiante de medicina una revisión completa y actualizada sobre estos dos temas. Para esto revisamos libros de texto reconocidos y utilizando MEDLINE, artículos representativos relacionados con el tema y mostramos un panorama general que incluye aspectos básicos de anatomía de los músculos extraoculares, nomenclatura y terminología empleada en estrabismo, aspectos de fisiología motora, pruebas clínicas utilizadas para el diagnóstico, generalidades sobre los principales tipos de estrabismo y manejo.

Strabismus and amblyopia are seen quite frecuently in the general population. Amblyopia is responsable for more unilaterally reduced vision of childhood onset than all other causes combined. There are severeal causes of strabismus while amblyopia is caused by three phisiopathologic states. We pretend to provide the primary care physician a general and up date review on this subject. In this article we reviewed recognized textbooks and, using MEDLINE some representative articles on this subject. We provide an overview of anatomical concepts, abbreviated designations for types of strabismus, some aspects on motor physiology, diagnostic techniques for strabismus and amblyopia, general concepts on various endodeviations and exodeviations and the management of each type.

Detección de ß talasemia mediante la técnica de amplificación refractaria de sistemas de mutaciones (ARMS-PCR) / ß thalassemia detection by the amplification refractory mutation system technique (ARMS-PCR)

Se empleó la técnica de amplificación refractaria de sistemas de mutaciones para determinar los tipos de mutaciones que causan ß talasemia (BTal) en la población venezolana. Ochenta pacientes seleccionados al azar de un total de 159 catalogados como ß talesémicos por presentar anemia hemolítica y niveles elevados de Hb A2, fueron estudiados por medio de la técnica de amplificación refractaria de sistemas de mutaciones (ARMS-PCR). Este es un método basado en la reacción en cadena de la polimerasa, capaz de detectar diversas mutaciones puntuales y pequeñas deleciones o inserciones en el gen ß globina, con el empleo de oligonuclótidos de secuencia específica. En 43/80 pacientes catalogados con las distintas presentaciones clínicas de ß talasemia y en 37/80 pacientes heterocigotos compuesto para hemoglobinotías estructurales y ß talasemia, la mutación más comúnmente encontrada fue la -29, (de origen africano), seguida de la CD39 (de origen mediterrráneo); también se encontró la -88, la IVSI-6 y con menor frecuencia la IVSI-110. La técnica ARMS- PCR es un método útil y rápido que permite detectar todas las mutaciones ß Tal presentes y hacer un diagnóstico diferencial entre los pacientes con Talasemia menor y sujetos normales con Hb A2 elevada, lo cual es importante en los estudios poblacionales, y además permite precisar el diagnóstico de los pacientes que presentan hemoglobinopatías estructurales con niveles elevados de Hb A2

Guía metodológica para el trabajo de la prevención de emergencias en el nivel pre-escolar

Se recopilan una serie de actividades encomendadas a sensibilizar frente a los riesgos y motivar a tomar medidas de protección. En él, se presentan alternativas lúdico- didácticas, para orientar el manejo objetivo de emergencias, despertando valores de prevención desde el nivel preescolar. En cada actividad se presenta un pequeño resumen que permitirá conocer más acerca del tema tratado. Además, se anexan una serie de fichas que ilustran algunas actividades sugeridas, las cuales pueden reproducirse para que los niños trabajen