Immunological features in pediatric patients with recurrent and severe infection: Identification of Primary Immunodeficiency Diseases in Merida, Venezuela.

INTRODUCTION AND OBJECTIVES: Primary immunodeficiency diseases (PIDs) are disorders associated mainly with recurrent and severe infection and an increase in susceptibility to autoimmune conditions and cancer. In Venezuela, PIDs are underdiagnosed and there is usually a delay in their diagnosis. Hence there are no data concerning the frequency and type of PIDs that occur. The aim of this study was to identify and quantify the types of PIDs that occur in Merida, a population within Venezuela. PATIENTS OR MATERIALS AND METHODS: Following an informative program designed to alert local health professionals to the warning signs for PIDs, patients with a history of recurrent infections were referred to the Instituto de Inmunologia Clinica, Universidad de Los Andes. RESULTS AND CONCLUSIONS: During the three-year period January 2014 to January 2017, thirty-two cases of PIDs were identified in pediatric patients, and 17 different types of PIDs, were identified. Predominantly antibody deficiencies were most frequent (40.6%), followed by immunodeficiencies affecting cellular and humoral immunity (21.8%), congenital defects of phagocyte (18.7%), CID with associated or syndromic features (9.3%), defects in intrinsic and innate immunity (6.4%) and diseases of immune dysregulation (3.2%). These results have important implications not only to the future approach for management of patients in our regions, but add important knowledge concerning PIDs in Latin America and worldwide.

Spatiotemporal chaos in sine-Gordon systems subjected to wave fields: onset and suppression.

The onset of spatiotemporal chaos in a damped sine-Gordon system subjected to a plane wave field as well as its suppression by an additional small-amplitude plane wave field are proposed theoretically and confirmed numerically. The relevance of these findings in the context of nonlinear magnetization waves is discussed.

Internal modes of sine-Gordon solitons in the presence of spatiotemporal perturbations.

We investigate the dynamics of the sine-Gordon solitons perturbed by spatiotemporal external forces. We prove the existence of internal (shape) modes of sine-Gordon solitons when they are in the presence of inhomogeneous space-dependent external forces, provided some conditions (for these forces) hold. Additional periodic time-dependent forces can sustain oscillations of the soliton width. We show that, in some cases, the internal mode even can become unstable, causing the soliton to decay into an antisoliton and two solitons. In general, in the presence of spatiotemporal forces the soliton behaves as a deformable (nonrigid) object. A soliton moving in an array of inhomogeneities can also present sustained oscillations of its width. There are very important phenomena (like the soliton-antisoliton collisions) where the existence of internal modes plays a crucial role.

Soliton tunneling with sub-barrier kinetic energies.

We investigate (theoretically and numerically) the dynamics of a soliton moving in an asymmetrical potential well with a finite barrier. For large values of the width of the well, the width of the barrier, and/or the height of the barrier, the soliton behaves classically. On the other hand, we obtain the conditions for the existence of soliton tunneling with sub-barrier kinetic energies. We apply these results to the study of soliton propagation in disordered systems.