Liposomes of phosphatidylcholine and cholesterol induce an M2-like macrophage phenotype reprogrammable to M1 pattern with the involvement of B-1 cells.

Macrophages respond to endogenous and non-self stimuli acquiring the M1 or M2 phenotypes, corresponding to classical or alternative activation, respectively. The role of B-1 cells in the regulation of macrophage polarization through the secretion of interleukin (IL)-10 has been demonstrated. However, the influence of B-1 cells on macrophage phenotype induction by an immunogen that suppress their ability to secrete IL-10 has not been explored. Here, we studied the peritoneal macrophage pattern induced by liposomes comprised of dipalmitoylphosphatidylcholine (DPPC) and cholesterol (Chol) carrying ovalbumin (OVA) (Lp DPPC/OVA), and the involvement of B-1 cells in macrophage polarization. Peritoneal cells from BALB/c, B-1 cells-deficient BALB/xid and C57BL/6 mice immunized with Lp DPPC/OVA and OVA in soluble form (PBS/OVA) were analyzed and stimulated or not in vitro with lipopolysaccharide (LPS). Peritoneal macrophages from BALB/c and C57BL/6 mice immunized with Lp DPPC/OVA showed an M2-like phenotype as evidenced by their high arginase activity without LPS stimulation. Upon stimulation, these macrophages were reprogrammable toward the M1 phenotype with the upregulation of nitric oxide (NO) and a decrease in IL-10 secretion. In addition, high IFN-γ levels were detected in the culture supernatant of peritoneal cells from BALB/c and C57BL/6 mice immunized with Lp DPPC/OVA. Nevertheless, still high levels of arginase activity and undetectable levels of IL-12 were found, indicating that the switch to a classical activation state was not complete. In the peritoneal cells from liposomes-immunized BALB/xid mice, levels of arginase activity, NO, and IL-6 were below those from wild type animals, but the last two products were restored upon adoptive transfer of B-1 cells, together with an increase in IFN-γ secretion. Summarizing, we have demonstrated that Lp DPPC/OVA induce an M2-like pattern in peritoneal macrophages reprogrammable to M1 phenotype after LPS stimulation, with the involvement of B-1 cells.

p73 plays a role in erythroid differentiation through GATA1 induction.

The TP73 gene gives rise to transactivation domain-p73 isoforms (TAp73) as well as DeltaNp73 variants with a truncated N terminus. Although TAp73alpha and -beta proteins are capable of inducing cell cycle arrest, apoptosis, and differentiation, DeltaNp73 acts in many cell types as a dominant-negative repressor of p53 and TAp73. It has been proposed that p73 is involved in myeloid differentiation, and its altered expression is involved in leukemic degeneration. However, there is little evidence as to which p73 variants (TA or DeltaN) are expressed during differentiation and whether specific p73 isoforms have the capacity to induce, or hinder, this differentiation in leukemia cells. In this study we identify GATA1 as a direct transcriptional target of TAp73alpha. Furthermore, TAp73alpha induces GATA1 activity, and it is required for erythroid differentiation. Additionally, we describe a functional cooperation between TAp73 and DeltaNp73 in the context of erythroid differentiation in human myeloid cells, K562 and UT-7. Moreover, the impaired expression of GATA1 and other erythroid genes in the liver of p73KO embryos, together with the moderated anemia observed in p73KO young mice, suggests a physiological role for TP73 in erythropoiesis.

Frecuencia de amputaciones por pie diabético en un área de salud / Amputation rate as caused by diabetic foot in a primary health care district

Se realizó un estudio de la frecuencia de amputaciones de miembros inferiores por síndrome del pie diabético en el área de salud “Ignacio Agramonte” de la ciudad de Camaguey, desde enero de 1998 a diciembre de 2003 para determinar la incidencia de amputaciones de miembros inferiores mediante la caracterización de los pacientes amputados. La incidencia de amputaciones por pie diabético se presentó en nueve pacientes, predominaron en las mujeres mayores de 50 años ,el nivel de amputación más frecuente fue el del pie vinculado al diabético mixto en cinco pacientes (55.5 por ciento).El tiempo de evolución de la diabetes mellitus mayor de 15 años constituyó un importante factor de riesgo, otros que favorecieron las amputaciones fueron la hiperglicemia, la neuropatía periférica, la oclusión de las arterias de las piernas, el sedentarismo, la hipertensión arterial y las amputaciones previas. La oclusión de las arterias de las piernas constituyó un factor de riesgo importante, se manifestó en ocho pacientes (88.8 por ciento), de ellos siete (81.5 por ciento) del total de pacientes con oclusiones arteriales presentaron un patrón oclusivo distal, los cuales sufrieron amputaciones a nivel de la pierna y el pie

Immunoblotting para diagnóstico de toxocarosis humana en un área subtropical / Immunoblotting for the diagnosis of human toxocarosis in a subtropical area

The diagnosis of toxocarosis is based upon the demonstration of antibodies by ELISA methods, although cross-reaction with other ascarids may occur in populations from tropical areas. For this reason, some authors proposed western blotting as a confirmatory test. The aim of this work was to develop an immunoblotting in simpler technical conditions and to compare results with the ELISA test. With this purpose sera from adults and children with sign and/or symptoms of toxocarosis and living in the metropolitan area of Resistencia city (Northeast of Argentina) were studied. ELISA test was performed and 120 positives and 60 negatives sera were selected and analyzed again by immunoblotting. Positive samples and controls showed a WB pattern with six bands of 67.6 kDa, 55.6 kDa, 43.9 kDa, 32.4 kDa, 26.6 kDa and 23.4 kDa, while negative controls from endemic and non-endemic areas of toxocarosis showed no bands. Out of the 180 samples studied, in 172 coincident results for both methods were obtained (95.6%), 6 ELISA negative samples were positive for WB (3.3%) and 2 ELISA positive samples resulted negative in the WB (1.1%). The immunoblotting technique described in this work may constitute an adequate method for the diagnosis of toxocarosis in subtropical areas, particularly useful in cases with negative or low-titers ELISA test results and with signs or symptoms of the infection.

El diagnóstico de toxocariosis se basa en la demostración de anticuerpos mediante enzimo-inmunoensayos, aunque en poblaciones de área tropicales suelen ocurrir reacciones cruzadas con otros ascáridos. Por ello algunos autores han propuesto el Western Blot como test confirmatorio. El objetivo de este trabajo fue desarrollar un método de immunoblotting con condiciones técnicas sencillas y comparar su comportamiento con la reacción de enzimoinmunoensayo. Se estudiaron 180 muestras de suero de adultos y niños con signo-sintomatología compatible con toxocariosis. Se efectuó test de ELISA con Antígenos TES, seleccionándose 120 sueros positivos y 60 negativos, los que fueron analizados nuevamente por immunobloting y se compararon los resultados de ambos métodos. Las muestras y controles positivos mostraron en el WB un patrón de seis bandas con PMs de 67,6 kDa, 55,6 kDa, 43,9 kDa, 32,4 kDa, 26,6 kDa y 23,4 kDa. Los sueros de control negativo de área endémica y no endémica de toxocarosis no mostraron banda alguna. De 180 muestras estudiadas, en 172 se obtuvieron resultados coincidentes por ambos métodos (95,6%), 6 muestras negativas por ELISA resultaron positivas por Western Blot (3,3%) y dos muestras positivas por ELISA fueron negativas por Western Blot (1,1%). El ensayo de immunoblotting acá descrito constituiría un método adecuado para el diagnóstico de toxocariosis en áreas sub-tropicales, particularmente útil en los casos en los que el test de ELISA resulte negativo o positivo con títulos bajos y en presencia de signos y/o síntomas de la infección.