Amit Berson

The Association for the Advancement of Medical Instrumentation develops voluntary standards for medical devices so that manufacturers might provide information on their product and basic safety and performance criteria that should be considered in qualifying the instrument for clinical use. American national standards are generated through a consensus process by committees consisting of experts in research, development, and design from user, industry, and government communities. Draft standards are made available for public review and may become American national standards after review by the American National Standards Institute. The first American national standard for electronic and automated sphygmomanometers was published in monograph form in 1987. The objective of the revised 1992 standard for electronic and automated sphygmomanometers is to provide updated labeling, safety, and performance requirements that help ensure that consumers and health care professionals are supplied with safe, accurate devices for the indirect measurement of blood pressure, including ambulatory blood pressure recorders. This standard permits validation of the automatic or electronic device by comparison with either direct, intra-arterial blood pressure measurements or the noninvasive cuff/stethoscope technique, based on Korotkoff sounds identified by individuals trained in auscultation. This summary report of the 1992 American national standard for automatic sphygmomanometers provides recommendations for the methods of comparison, statistical analysis of the data, presentation of the results, and criteria for acceptability. Users, researchers, and instrument designers should refer to the American national standard monograph for detailed requirements.

Aging is the strongest risk factor for Alzheimer’s disease (AD), although the underlying mechanisms remain unclear. The chromatin state, in particular through the mark H4K16ac, has been implicated in aging and thus may play a pivotal role in age-associated neurodegeneration. Here we compare the genome-wide enrichment of H4K16ac in the lateral temporal lobe of AD individuals against both younger and elderly cognitively normal controls. We found that while normal aging leads to H4K16ac enrichment, AD entails dramatic losses of H4K16ac in the proximity of genes linked to aging and AD. Our analysis highlights the presence of three classes of AD-related changes with distinctive functional roles. Furthermore, we discovered an association between the genomic locations of significant H4K16ac changes with genetic variants identified in prior AD genome-wide association studies and with expression quantitative trait loci. Our results establish the basis for an epigenetic link between aging and AD. By comparing the genome-wide profile of H4K16ac in AD with younger and elder controls, the authors propose a mechanism for how age is a risk factor for AD: a histone modification, whose accumulation is associated with aging, is dysregulated in AD.

Immunoreactive parathyroid hormone was measured by radioimmunoassay in extracts of parathyroid glands and tumors and in plasmas from patients with 1°, 2° or 3° hyperparathyroidism. On serial dilution most extracts showed approximately parallel behavior in 2 or 3 different antisera. However, plasma specimens referred to the same extract as standard frequently showed greater immunoreactivity in 2 antisera (272 and 273) than in a third antiserum (C329). This anomaly was more marked in plasma from patients with hyperparathyroidism secondary to renal insufficiency than in plasma from patients with 1° hyperparathyroidism and was exhibited by some extracts of adenomas as well. Following parathyroidectomy, the apparent disappearance of parathyroid hormone was more rapid when measured in antiserum C329 than in antiserum 273 and in both antisera was slower in patients with renal insufficiency than in patients with 1° hyperparathyroidism. These findings suggest that parathyroid hormone in human plasma is immunochemically heterogeneous, that removal of one or more of the peptides from the circulation may be dependent on renal function, and that metabolic alteration of the hormone may account for the immunochemical heterogeneity.