[Familial junctional ectopic tachycardia: clinical and pathological findings]. / Forma familiar de la taquicardia ectópica de la unión: hallazgos anatomoclínicos.

We describe two brothers with a neonatal diagnosis of junctional ectopic tachycardia. The first brother presented hydrops fetalis secondary to narrow QRS tachycardia at a rate of 230-300 beats/min with atrioventricular dissociation. Although the ventricular rate was controlled with intravenous amiodarone the baby died a few hours after initiation of this treatment from ventricular fibrillation and electromechanical dissociation. Histological examination of the conduction system showed diffuse hemorrhage and necrosis of the atrioventricular node and His' bundle. The second brother presented fetal distress and polyhydramnios and the postnatal electrocardiogram revealed junctional ectopic tachycardia at a rate of 170 beats/min alternating with sinus rhythm, which was controlled without treatment.

Forma familiar de la taquicardia ectópica de la unión: hallazgos anatomoclínicos / Familial junctional ectopic tachycardia: clinical and pathological findings

Se presentan los casos de 2 hermanos con taquicardia ectópica de la unión diagnosticados en el período neonatal. El primero se inició como hydrops fetal y se registró una taquicardia de 230 a 300 lat./min con complejo QRS estrecho y disociación auriculoventricular. La frecuencia ventricular se controló con amiodarona intravenosa, aunque falleció a las pocas horas de su inicio por fibrilación ventricular y disociación electromecánica. El estudio histológico del tejido de conducción demostró la presencia de hemorragia y necrosis difusa del nodo auriculoventricular y del haz His. El segundo caso presentó sufrimiento fetal agudo y polihidramnios y en el electrocardiograma posnatal se documentó una taquicardia de la unión a 170 lat./ min alternando con ritmo sinusal, que se ha controlado sin tratamiento (AU)

Changes in the fetal tibial growth plate secondary to maternal zinc deficiency in the rat: a histological and histochemical study.

Zinc deficiency (ZD) is teratogenic in rats, and fetal skeletal defects are prominent. To elucidate further the effects of maternal ZD in the fetal skeleton, we performed a morphological and histochemical study of tibial growth plate (GP) in ZD rat fetuses. The histochemical study included the identification of calcium, of hydrolytic enzymes associated with the process of calcification, and of oxidative enzymes related to energy production and to the synthesis of proteoglycans. Pregnant Sprague-Dawley rats were fed (1) a control diet (76.4 micrograms Zn/g diet) ad libitum (group C), (2) a zinc-deficient diet (0 micrograms/g) ad libitum (group ZD), or (3) the control diet pair-fed to the ZD rats (group PF). On day 21 of gestation, laparotomies were performed, the fetuses were removed, and fetal tibiae obtained. Specimens were stained with hematoxylin-eosin (H&E) and Masson Trichrome and were processed for identification of alkaline phosphatase, adenosine triphosphatase, succinic dehydrogenase, NADH dehydrogenase, and calcium. The morphologic patterns found in ZD fetal tibiae indicated defects in various cell types implicated in bone metabolism. Staining for hydrolytic enzymes revealed alterations in the size and distribution of matrix vesicles and a weaker staining for ATPase in ZD fetuses. Staining for oxidative enzymes was overall more intense in ZD fetal tibiae. ZD fetuses also presented irregular and defective calcification. These findings indicate that severe maternal ZD in the rat results in structural and functional alterations in the GP of fetal bone, leading to a defective endochondral ossification.

Nonimmunologic hydrops fetalis: an etiopathogenetic approach through the postmortem study of 59 patients.

Aiming at increasing our understanding of the various causative factors of nonimmunologic hydrops fetalis (NIHF) and their pathogenetic mechanisms, we have reviewed 59 cases of this condition from a total number of 4,175 pediatric post-mortem studies performed at the Department of Pathology of the Hospital La Paz from 1967 to 1987. We found eight cases (13.5%) without clinical, biochemical, or post-mortem findings justifying the development of hydrops fetalis, seven cases (12%) associated with certain pathologic findings that by themselves do not explain the development of hydrops and, finally, 44 cases (74.5%) in whom pathological findings may explain the development of the condition. Notwithstanding the etiological diversity of this last group, in 31 of these cases (70%), some common pathogenetic features may be recognized, basically a failure of the right ventricle of the heart in the fetus or newborn, due to a primary heart condition, to intracardiac tumors, or to obstructive phenomena at the level of the right venous drainage. In our opinion, whenever NIHF is diagnosed or suspected, causes of right cardiovascular failure should be investigated, since about 50% of all cases seem to be due to this pathogenetic mechanism.

Report of a case: acromesomelic dysplasia: radiologic, clinical, and pathological study.

We report a 51-year-old woman with acromesomelic dysplasia. Pathologic studies on adult bone are reported. Hydrocephalus and mild oligophrenia are additional findings.

Tumoral calcinosis in two infants.

Tumoral calcinosis (TC) is an uncommon disease, characterized by deposits of large, calcified painless soft-tissue masses around major joints in otherwise healthy children and young adults. This condition is a rare inherited metabolic disorder of unknown etiology. Biochemical findings are normal except for its occasional association with hyperphosphatemia. The youngest occurrence reported in the literature on TC may be one case of a five-month-old boy. The authors report here on two younger infants with TC, one aged ten days and the other aged three months, who were followed for more than three years and observed to completely recover all motorskeletal functions.