Use of sonography to evaluate carotid atherosclerosis in the elderly. The Cardiovascular Health Study. CHS Collaborative Research Group

Carotid sonography is being performed on more than 5,000 participants in the Cardiovascular Health Study, a prospective, multicenter study of cardiovascular disease in men and women aged 65 years and older. The sonographic methods used to examine and measure the extracranial carotid arteries are described. Initial validation studies were performed on 61 subjects with a mean age of 68.6 years. Analysis of within- and between-sonographer differences and between-reader differences were performed for selected variables. In general, the mean absolute differences for within- and between-sonographer comparisons were small, with even less variability between readers. Variability was less for the common carotid artery than for the internal carotid artery. These data suggest that carotid sonography is a reliable and reproducible method for use in the study of carotid atherosclerosis in population studies.     

Parathyroidectomy for hyperparathyroidism associated with renal disease.

Between 1969 and 1993, 123 patients were accepted in this unit for surgery for refractory hyperparathyroidism associated with chronic renal failure. Subtotal parathyroidectomy was the procedure of choice. At operation, four or more parathyroids were identified in 75% of patients. Methylene blue localised additional parathyroids in 32% of initial explorations in which it was used. Coincidental thyroid pathology was found in 8.3%, including papillary carcinoma in 2.4%. No further parathyroid surgery was required in 90% of patients at a mean of 6.6 years after operation. Reoperation (10%) was more likely to be required (14.3%) when less than four glands were found than when four or more were found (8.5%). Patients continuing on dialysis were more likely to need reoperation than those with functioning renal transplants.     

Influence of position along the medial-lateral axis of the superior colliculus on the topographic targeting and survival of retinal axons.

Topographic order in the rat retinocollicular projection emerges from an initially diffuse projection during an early postnatal remodeling period that is coincident with the period of naturally occurring ganglion cell death. Here, we examine the relationship between a retinal axon's position along the medial-lateral axis as it enters the superior colliculus (SC) and its ability to form an appropriately positioned arbor and survive the remodeling period. At E18-E19, prior to map remodeling, axons labeled with focal DiI injections in the periphery of temporal, nasal, superior or inferior retina are widespread along the medial-lateral SC axis. At P12, after remodeling, the distributions of axons remain widespread over the medial-lateral SC axis relative to the positioning of their terminal arborizations, and resemble the distributions labeled at E18-E19, with the exception that the small proportion of axons most widely mispositioned along the medial-lateral SC axis are less frequent. These data indicate that the most widely mispositioned retinal axons are preferentially eliminated, but that a high proportion of retinal axons mispositioned along the medial-lateral axis as they enter the SC can correct their position, form topographically appropriate arbors, and survive the remodeling period.     

Hypertension in neuroblastoma induced by imipramine

Hypertension is a well-known finding in some patients with neuroblastoma. However, it has not previously been described in association with the use of Imipramine. We report the occurrence of severe hypertension (blood pressure 190/160) in a 4-year-old girl with neuroblastoma who was given Imipramine to control a behavior disorder. It was determined later that this patient's tumor was recurring at the time of her hypertensive episode. Since she had no blood pressure elevation at initial diagnosis and none following discontinuation of the Imipramine (when she was in florid relapse), we believe that this drug rather than her underlying disease alone caused her hypertension. The mechanism for this reaction is believed to be increased levels of vasoactive catecholamines due to interference of their physiologic inactivation by Imipramine. From this experience, we urge extreme caution in the use of tricyclic antidepressants in children with active neuroblastoma.     

Incision depth affects the recovery of corneal sensitivity and neural regeneration in the cat

To assess the effect of incision depth on the recovery of corneal sensitivity and neural regeneration, adult domestic cats underwent either 8-mm circular nonpenetrating keratotomies or penetrating autografts. The contralateral eye served as control. Corneal sensitivity was determined at various intervals after surgery. The depth of incision in the nonpenetrating keratotomies, assessed by optical pachometry, ranged between 49 and 91% of total corneal thickness. The animals were ranked based on the depth of incision and the average sensitivity within the keratotomy over the 1-yr recovery period. A significant negative correlation was found between incision depth and the recovery of sensitivity (Spearman rank-order correlation r = -0.84, P less than 0.05). Some recovery of sensitivity was found in the center and periphery of the incised zone when incision depth was less than 53% of total corneal thickness. With deeper incisions, the center of the incised zone remained insensitive throughout the measurement period, while the periphery of the incised zone showed a slight recovery of corneal sensitivity, proportional to incision depth. The recovery of corneal sensitivity was higher in a small annular region just distal to the incision site. When incision depth exceeded approximately 53%, gold chloride impregnation showed that the resultant reinnervation was confined to single intraepithelial axons or localized regions of irregular epithelial fibers. With shallower incisions, the deeper stromal trunks were spared, resulting in the persistence of a reduced subepithelial plexus and basal epithelial leashes. We have shown that when an incision severs all stromal trunks, the neural regeneration is insufficient for functional recovery of corneal sensitivity at the center of an 8-mm keratotomy.(ABSTRACT TRUNCATED AT 250 WORDS)