Double Heterotopic Pregnancies with Live Intrauterine Pregnancy after Ovarian Stimulation.

Heterotopic pregnancies, although rare in natural conceptions, have increased in incidence with use of assisted reproductive techniques (ART). Double heterotopic pregnancy in addition to an intrauterine pregnancy is exceedingly rare. In this case, we present a patient who underwent ovulation induction and intrauterine insemination (IUI) and was found on ultrasound to have a live heterotopic pregnancy. Intraoperatively, both fallopian tubes were grossly swollen and engorged. Bilateral salpingectomy was performed. Pathology identified gestational products in both fallopian tubes consistent with a double heterotopic pregnancy. Postoperatively, the intrauterine pregnancy resulted in a live birth. Although double heterotopic pregnancy and an intrauterine pregnancy is exceedingly rare, this case emphasizes the importance of routinely inspecting the contralateral fallopian tube at the time of surgery for an ectopic pregnancy, particularly in patients undergoing ovulation induction.

Relación entre la presencia de tiroiditis linfocítica con la gravedad y recurrencia/persistencia del carcinoma diferenciado de tiroides / Relationship Between the Presence of Lymphocytic Thyroiditis with the Severity and Recurrence/Persistence of Differentiated Thyroid Carcinoma

Introducción: Para el sistema endocrino la neoplasia más frecuente es el cáncer diferenciado de tiroides, con un claro incremento en su incidencia. Es importante encontrar asociaciones que posteriormente permitan establecer factores de riesgo y/o protectores claves en la estrategia terapéutica futura. Por lo que se investigó la relación entre la presencia de tiroiditis linfocítica con la gravedad y persistencia/recurrencia del carcinoma diferenciado de tiroides Materiales y métodos: se hizo un estudio comparativo a través de una serie de casos de carcinoma diferenciado de tiroides llevados a cirugía entre enero de 1997 y diciembre de 2012 en una clínica especializada de nivel IV ubicada en Bogotá, Colombia. Se evaluó la asociación entre la presencia de factores clínico-patológicos y la presencia de persistencia/recurrencia usando pruebas de asociación chi cuadrado y odds ratios. Para evaluar la presencia de asociación a nivel multivariado se utilizaron modelos de regresión binaria con enlace log log complementario. Resultados: no se observó asociación estadística entre presencia de tiroiditis linfocítica y la presencia de variables de severidad clínico-patológica. Sin embargo, fue posible evidenciar asociación entre tiroiditis linfocítica con persistencia/recurrencia en presencia invasión vascular (OR 6,6 IC95% 1,4-32), invasión linfática (OR 5,4 IC95% 1,3-22,1) y compromiso ganglionar en el vaciamiento lateral (OR 58 IC95% 7,1-476) independiente de la edad y el sexo. Conclusión: Es posible que la tiroiditis linfocítica no se relacione con la presencia de marcadores de severidad clínico-patológica pero sí con una mayor persistencia/recurrencia de la enfermedad. Rev Argent Endocrinol Metab 51:169-177, 2014 Los autores declaran no poseer conflictos de interés.

Introduction: Differentiated thyroid cancer is the most common malignancy and it shows an increased incidence. It is important to find associations that may allow for identification of key risk and/or protective factors for the development of future therapeutic strategies. Thus, we investigated the relationship between the presence of lymphocytic thyroiditis with severity and persistence / recurrence. Materials and methods: We conducted a comparative study using data from patients with differentiated thyroid carcinoma who had undergone total or partial thyroidectomy between January 1997 and December 2012 at a Level IV specialized institution located in Bogotá, Colombia. We evaluated the association between the presence of clinical and pathological factors and the presence of persistence/recurrence using chi-square tests and OR. For multivariate analysis a binary regression model with complementary log-log link was used. Results: No statistically significant relationship was observed between lymphocytic thyroiditis and the presence of clinical-pathological severity factors. However, lymphocytic thyroiditis was associated with persistence / recurrence in the presence of vascular invasion (OR 6.6 95 % CI 1.4-32), lymphatic invasion (OR 5.4 95 % CI 1.3-22.1) and positive lateral neck nodes (OR 58 95 % CI 7.1-476), independently of gender and age. Conclusion: Lymphocytic thyroiditis may not be associated with the presence of markers of clinical-pathological factors but it is effectively associated with a higher persistence/recurrence of disease. Argent Endocrinol Metab 51:169-177, 2014 No financial conflicts of interest exist.

Neurotecoma celular atípico nasal / Atipical nasal cellular neurothecoma

El neurotecoma hace parte del raro y heterogéneo grupo de tumores mixoides de los tejidos blandos. Inicialmente se llamó mixoma dérmico de vaina nerviosa por la semejanza de sus células Inmorales con las células de Schwnann. Es un tumor benigno típicamente dérmico que afecta principalmente a los adultos jóvenes, con un predominio en las mujeres y de localización más frecuente en la cabeza y el cuello. Histológicamente se divide en neurotecoma mixoide, intermedio y celular. Ultraestructuralmente se han identificado cuatro tipos celulares y por inmunohistoquímica tiñen con marcadores de músculo liso y enolasa neuroespecífica. Se describe un neurotecoma celular nasal en un hombre de 25 años con múltiples biopsias que sugirieron los diagnósticos de tumor fusocelular, melanoma y xantofíbroma atípico

Functional stabilization of unstable fixed points: human pole balancing using time-to-balance information.

Humans are often faced with tasks that require stabilizing inherently unstable situations. The authors explored the dynamics of human functional stabilization by having participants continually balance a pole until a minimum time criterion was reached. Conditions were manipulated with respect to geometry, mass, and characteristic "fall time" of the pole. Distributions of timing between pole and hand velocities showed strong action-perception coupling. When actions demonstrated a potential for catastrophic failure, the period of hand oscillation correlated well with the perceptual quantity "time to balance" (tau(bal) = theta/theta), but not other quantities such as theta and theta alone. This suggests that participants were using available tau(bal) information during critical conditions, although they may not have been attending to this type of perceptual information during typical, noncritical motions of successful performance. In a model analysis and simulation, the authors showed how discrete tau(bal) information may be used to adjust the parameters of a controller to perform this task.

Recruitment of degrees of freedom stabilizes coordination.

By showing that transitions may be obviated by recruiting degrees of freedom in the coupled pendulum paradigm, the authors reveal a novel mechanism for coordinative flexibility. In Experiment 1, participants swung pairs of unconstrained pendulums in 2 planes of motion (sagittal and frontal) at 8 movement frequencies starting from either an in-phase or antiphase mode. Few transitions were observed. Measures of spatial trajectory showed recruitment effects tied to the stability of the initial coordinative pattern. When the motion of the pendulums was physically restricted to a single plane in Experiment 2, transitions were more common, indicating that recruitment delays--or even eliminates--transitions. Such recruitment complements transitions as a source of coordinative flexibility and is incorporated in a simple extension of the Haken-Kelso-Bunz (1985) model.

Self-organization of trajectory formation. I. Experimental evidence.

Most studies examining the stability and change of patterns in biological coordination have focused on identifying generic bifurcation mechanisms in an already active set of components (see Kelso 1994). A less well understood phenomenon is the process by which previously quiescent degrees of freedom (df) are spontaneously recruited and active df suppressed. To examine such behavior, in part I we study a single limb system composed of three joints (wrist, elbow, and shoulder) performing the kinematically redundant task of tracing a sequence of two-dimensional arcs of monotonically varying curvature, kappa. Arcs were displayed on a computer screen in a decreasing and increasing kappa sequence, and subjects rhythmically traced the arcs with the right hand in the sagittal plane at a fixed frequency (1.0 Hz), with motion restricted to flexion-extension of the wrist, elbow, and shoulder. Only a few coordinative patterns among the three joints were stably produced, e.g., in-phase (flexion-extension of one joint coordinated with flexion-extension of another joint) and antiphase (flexion-extension coordinated with extension-flexion). As kappa was systematically increased and decreased, switching between relative phase patterns was observed around critical curvature values, kappa c. A serendipitous finding was a strong 2:1 frequency ratio between the shoulder and elbow that occurred across all curvature values for some subjects, regardless of the wrist-elbow relative phase pattern. Transitions from 1:1 to 2:1 frequency entrainment and vice versa were also observed. The results indicate that both amplitude modulation and relative phase change are utilized to stabilize the end-effector trajectory. In part II, a theoretical model is derived from three coupled nonlinear oscillators, in which the relative phases (phi) between the components and the relative joint amplitudes (rho) are treated as collective variables with arc curvature as a control parameter.

Self-organization of trajectory formation. II. Theoretical model.

Most studies of movement coordination deal with temporal patterns of synchronization between components, often without regard to the actual amplitudes the components make. When such a system is required to produce a composite action that is spatially constrained, coordination persists, but its stability is modulated by spatial requirements effected, we hypothesize, through the component amplitudes. As shown experimentally in part I, when a redundant three-joint system (wrist, elbow, and shoulder) is required to trace a specified arc in space, the joint angles may be frequency- and phased-locked even as the curvature of the trajectory is manipulated. Transitions between joint coordination patterns occur at a critical curvature, accompanied by a significant reduction in wrist amplitude. Such amplitude reduction is viewed as destabilizing the existing coordinative pattern under current task constraints, thereby forcing the joints into a more stable phase relationship. This paper presents a theoretical analysis of these multijoint patterns and proposes an amplitude mechanism for the transition process. Our model uses three linearly coupled, nonlinear oscillators for the joint angles and reproduces both the observed interjoint coordination and component amplitude effects as well as the resulting trajectories of the end effector.