Human B-cell studies in vitro have routinely used B lymphocytes purified from spleen, blood or tonsils irrespective of potential differences in their immunological traits. In this study, we compared the functional responses of total (CD19(+)) and memory B cells (Bmem; CD19(+)/CD27(+)) isolated from blood and tonsils to different stimuli. Peripheral B cells showed enhanced survival and proliferation compared with their tonsillar equivalents when stimulated for 10 days. Stimulated B cells from both tissues secreted significantly greater amounts of cytokines than unstimulated controls demonstrating their functional responsiveness. Analysis of CD27 expression over time indicated that the conditions that promoted survival and proliferation of peripheral Bmem, caused massive tonsillar Bmem death. Purified tonsillar Bmem failed to expand but rapidly differentiated in antibody secreting cells and subsequently underwent apoptosis. In contrast, circulating Bmem showed delayed activation and differentiation, but exhibited a longer lifespan and active proliferation. In addition, short-term stimulation of tonsillar Bmem resulted in the production of more immunoglobulin G (IgG) than their peripheral counterparts. At later time points, however, IgG production from the different B cells was reversed. Our findings imply that the tissue located and peripheral Bmem have distinct behaviors, indicating organ dependent functional responses that should not be generalizable to all Bmem. This work provides a greater understanding of how Bmem location is coupled to specialized roles of B lymphocytes.

The objective of this study was to evaluate gender differences in the pain threshold, considering the type of pressure point, its location and the repetition of the assessment. The pressure pain threshold was evaluated in 30 healthy volunteers (12 men and 18 women) in three assessment sessions separated by 15 min and 7 days, respectively. Each assessment session was in turn composed of two trials in each of which 24 different pressure points (symmetrically located), representing the 18 tender points for the diagnosis of fibromyalgia and six control points, were assessed. Gender differences were found in the pain threshold for all of the points and the measures taken, women showing a lower pain threshold in comparison to men and being these differences more pronounced for control points than for tender points, the former reaching statistical significance in all cases. The analysis of the influence of repeated measures on gender differences in the pain threshold showed a distinct pattern of recuperation in men than in women, although only one difference in pain threshold was significant. The utility of the tender point concept to study gender differences in pain threshold and the mechanisms that may explain different patterns of recuperation between genders are discussed.

The expression of N-glycolyl-monosialodihexosyl-ganglioside (NGcGM3) in humans is restricted to cancer cells; therefore, it is a tumor antigen. There are measurable quantities of circulating anti-NGcGM3 antibodies (aNGcGM3 Abs) in human serum. Interestingly, some people have circulating Ag-specific immunoglobulins G (IgGs) that are capable of complement mediated cytotoxicity against NGcGM3 positive cells, which is relevant for tumor surveillance. In light of the chemical nature of Ag, we postulated it as a candidate ligand for CD1d. Furthermore, we hypothesize that the immune mechanism involved in the generation of these Abs entails cross talk between B lymphocytes (Bc) and invariant natural killer T cells (iNKT). Combining cellular techniques, such as flow cytometry and biochemical assays, we demonstrated that CD1d binds to NGcGM3 and that human Bc present NGcGM3 in a CD1d context according to two alternative strategies. We also showed that paraformaldehyde treatment of cells expressing CD1d affects the presentation. Finally, by co-culturing primary human Bc with iNKT and measuring Ki-67 expression, we detected a reproducible increment in the proliferation of the iNKT population when Ag was on the medium. Our findings identify a novel, endogenous, human CD1d ligand, which is sufficiently competent to stimulate iNKT. We postulate that CD1d-restricted Bc presentation of NGcGM3 drives effective iNKT activation, an immunological mechanism that has not been previously described for humans, which may contribute to understanding aNGcGM3 occurrence.

Se revisa la evolución de un grupo de trabajadores que recibieron las primeras 100 altas tras la adquisición de dicha competencia por los inspectores médicos evaluadores del Instituto Nacional de la Seguridad Social (INSS) a finales de 2010 y cuyas características ya se habían publicado. Seguidos durante los 18 meses siguientes, se revisan los nuevos procesos de Incapacidad Temporal  (IT), así como otros expedientes relacionados y se estudian a la luz de un elemento clave en la consulta de valoración médica de incapacidad, la distorsión clínica, entendida como la impresión subjetiva por parte del evaluador de una desproporción entre los elementos objetivos y subjetivos del caso. Destaca la frecuente recaída en IT en el periodo estudiado (roza el 40%), la constancia de los diagnósticos motivos de dichos episodios, su mayor complejidad (más edad, más pago directo…) y duración, así como la relación entre estos elementos y el grado de distorsión clínica observado en la primera consulta, que se plantea como el punto de partida natural para la gestión en consulta del posible fraude por simulación, desde el marco teórico del análisis de conducta en medicina