Carcinoma insular de tiroides. Presentación de dos casos / Insular thyroid carcinoma. Report of two cases

El carcinoma insular de tiroides es una neoplasia poco frecuente que histológicamente se caracteriza por la agrupación de células foliculares que forman islotes. Aún no están bien definidos algunos aspectos clínicos y pronósticos de este tumor dada la escasa casuística que existe sobre éste. No obstante, se acepta que su pronóstico es intermedio entre los carcinomas diferenciados de tiroides (papilar y folicular) y los anaplásticos. Se presentan dos pacientes que consultaron por tumoración cervical asintomática, en los que el diagnóstico fue de carcinoma insular de tiroides. La citología obtenida mediante punción aspiración con aguja fina fue sospechosa de malignidad en ambos, perono diagnóstica. El primero de ellos presentó un patrón de carcinoma adenoide quístico, atípico en las punciones tiroideas. En los dos pacientes se realizó tiroidectomía total y tratamiento con 131 I (AU)

Viscosity minimum in bimodal concentrated suspensions under shear.

We study a model of concentrated suspensions under shear in two dimensions. Interactions between suspended particles are dominated by direct-contact viscoelastic forces and the particles are neutrally bouyant. The bimodal suspensions consist of a variable proportion between large and small droplets, with a fixed global suspended fraction. Going beyond the assumptions of the classical theory of Farris (R.J. Farris, Trans. Soc. Rheol. 12, 281 (1968)), we discuss a shear viscosity minimum, as a function of the small-to-large-particle ratio, in shear geometries imposed by external body forces and boundaries. Within a linear-response scheme, we find the dependence of the viscosity minimum on the imposed shear and the microscopic drop friction parameters. We also discuss the viscosity minimum under dynamically imposed shear applied by boundaries. We find a reduction of macroscopic viscosity with the increase of the microscopic friction parameters that is understood using a simple two-drop model. Our simulation results are qualitatively consistent with recent experiments in concentrated bimodal emulsions with a highly viscous or rigid suspended component.

[Effect of preconceptional metabolic control in the course of pregnancy in diabetic patients]. / Influencia del control metabólico preconcepcional en la evolución de la gestación de la paciente diabética.

BACKGROUND: We analysed the relationship between metabolic control parameters during the preconception stage and pregnancy outcome in diabetic patients. PATIENTS AND METHOD: We examined 69 diabetic patients who underwent a preconception control at the Diabetes and Pregnancy Unit between 1992-1998. At the end of the preconception care period, 50 women (72.6%) became pregnant. Eight out of them (16%) had an abortion. RESULTS: Women who had an abortion did not differ from those who had not an abortion with regard to HbA1c levels at the end of the preconception period, age, duration of diabetes, age at diagnosis,anti-thyroid antibodies or microvascular disease. Among 41 single age stations, fetal macrosomia was observed in 36.6% cases, neonatal hypoglycemia in 19.5% and major congenital malformations in one case. Average level of HbA1c was 7.6 +/- 1.3%and 6.5 +/- 0.7 at the beginning and at the end of the preconception period, respectively (p < 0.001). In the group with macrosomia,average HbA1c at the end of the preconception period was 6.8 +/- 0.66% as opposed to 6.3 +/- 0.7% for the non-macrosomic group (p < 0.05). A linear correlation was seen between HbA1c levels at the end of the preconception period and infant weight (r = 0,432; p = 0,014), birth weight ratio (r = 0,450; p = 0,009), and a morbidity score (r = 0,458;p = 0,007). CONCLUSIONS: A better metabolic control during the preconception period may contribute to lessen the risk of fetal macrosomia and neonatal morbidity.