Evaluating the empirical support for the Geschwind-Behan-Galaburda model of cerebral lateralization

The Geschwind-Behan-Galaburda (GBG) model of cerebral lateralization provides a complex but testable theory of the origins and associates of cerebral lateralization. An overall evaluation of the model suggest that it is not well supported by empirical evidence and that in the case of several key theoretical areas, the evidence that does exist is inconsistent with the theory. In particular: the concept of "anomalous dominance" is shown to be theoretically and methodologically flawed; a meta-analysis of the relationship between handedness and immune disorders finds a marginal overall association, and while three conditions (allergies, asthma, and ulcerative colitis) do show significant associations with left-handedness, two other conditions (myasthenia gravis and arthritis) show significant negative associations with left-handedness. Finally, a review of the origins of the neural crest, and its associations, suggests there is almost no empirical support for the GBG theoretical model in this area.

Applying Embryo-Derived Immune Tolerance to the Treatment of Immune Disorders

Pregnancy is a unique immune state in which both mother and embryo/fetus tolerate and interact with one another through term, without interfering with the mother's native immunity. When the embryo is viable, it initiates maternal immune tolerance (IT)--ut not immune suppression. The balance is complex: some immune disorders are ameliorated during pregnancy, despite the presence of an "inflammatory" environment. We have identified a pregnancy viability biomarker--preimplantation factor (PIF)--secreted only by viable embryos, which helps to initiate this maternal tolerance and uterine receptivity. Using anti-PIF antibodies, we have detected PIF in the fetus and placenta. Beyond enhancing uterine receptivity locally, PIF has also been detected in maternal circulation, and may promote peripheral tolerance. In the fetus, PIF may help avoid a "graft-versus-host"-type reaction PIF exhibits unique potent immune-modulatory effects and its synthetic analogue has been shown to exert significant protection in diverse immune scenarios. Nontoxic, low-dose, short-term PIF administration has led to long-term effects in preclinical models of multiple sclerosis (MS), juvenile diabetes mellitus (JDM), and graft-versus-host disease (GVHD), in a manner enabling its translation into a clinical setting. Further investigation of this compound is warranted.

Keystones in lymph node development

New molecular markers are constantly increasing our knowledge of developmental processes. In this review article we have attempted to summarize the keystones of lymphoid tissue development in embryonic and pathological conditions. During embryonic lymph node development in the mouse, cells from the anterior cardinal vein start to bud and sprout, forming a lymph sac at defined sites. The protrusion of mesenchymal tissue into the lymph sacs forms the environment, where so-called 'lymphoid tissue inducer cells' and 'mesenchymal organizer cells' meet and interact. Defects of molecules involved in the recruitment and signalling cascades of these cells lead to primary immunodeficiency diseases. A comparison of molecules involved in the development of secondary lymphoid organs and tertiary lymphoid organs, e.g. in autoimmune diseases, shows that the same molecules are involved in both processes. This has led to the hypothesis that the development of tertiary lymphoid organs is a recapitulation of embryonic lymphoid tissue development at ectopic sites.