An estimate of the extent of folding of nucleosomal DNA by laterally asymmetric neutralization of phosphate groups.

We attempt quantitative implementation of a previous suggestion that asymmetric charge neutralization of DNA phosphate groups may provide part of the driving force for nucleosome folding. Polyelectrolyte theory can be used to estimate the effective compressive force acting along the length of one side of the DNA surface when a fraction of the phosphate groups are neutralized by histones bound to that side. A standard engineering formula then relates the force to the bending amplitude caused by it.

Phaeochromocytoma and mitral valve replacement.

A phaeochromocytoma was diagnosed following a mitral valve replacement and coronary artery bypass in a patient with progressive mitral regurgitation. Despite a previous adverse reaction to anaesthesia, this was not predicted perhaps due to his cardiac disease. Fever, leucocytosis and confusion were also prominent features.

An historical review of the electrocardiogram of right bundle branch block in the Royal Canadian Air Force.

During the course of the Royal Canadian Air Force Electrocardiographic Program (1939-1986) a selected study of fit aircrew with right bundle branch block was studied. This review covers a period of 18 years during which a consecutive study of 139,651 men from 1960 to 1978 was carried out. Incomplete right bundle branch block of 0.

A signal-processing research facility and its application to the processing of fetal phonocardiographic signals for heart rate estimation.

Part 1 of this paper describes a real-time medical signal-processing research facility which is being developed at Edinburgh University. Part 2 describes the application of this facility to the estimation of fetal heart rate from phonocardiographic signals using a new frequency-domain estimation algorithm.

The trajectory of a stiff rod in a curved potential energy trough. An initial result for short nucleosomal rods.

The equilibrium trajectory of the axis of a rod subject to an externally imposed curved potential energy trough tends to conform to the shape of the curved trough, but also tends to be straight because of elastic resistance to bending. The actual path of the axis is a balance between the two extremes. We consider a potential energy trough centered along a circular arc of radius R.

Packaged DNA. An elastic model.

We review and deepen a theory of elastic bending of DNA on a persistence length scale. In a regime of extensive charge neutralization the axis of the double helix is elastically unstable when straight. Its stable bent conformation allows nucleation of DNA toruses and in principle could direct the supercoiled (solenoid) form of a polynucleosome.

Multiple endocrine neoplasia, type I. Association with marfanoid habitus, optic atrophy, and other abnormalities.

A patient had a parathyroid adenoma and prolactin-secreting pituitary tumor, suggestive of the multiple endocrine neoplasia (MEN) I syndrome. The presence of a marfanoid habitus--found more typically in MEN III syndrome--as well as mitral valve prolapse, mental retardation, and bilateral optic atrophy suggests a new variant of the MEN syndrome, possibly representing widespread dysplasia of endocrine and other tissues.

Study of an analytical method for hexavalent chromium.

The diphenylcarbazide colorimetric method was evaluated by analyzing spiked PVC filters prepared by an AIHA-accredited consultant laboratory for chromium (VI). All seven participating laboratories received the samples and performed the analyses at the same time. Three laboratories simultaneously tested three alternative analytical procedures.

Alternatives in the handling, processing and storage of electrocardiograms.

Physicians and administrators are becoming aware that computer technology can play a significant role in the electrocardiology department. Problems related to the large number of requests for electrocardiograms, the production and communication of electrocardiographic tracings and reports, the access to stored tracings and the overall cost of providing effective services have led administrators to look for assistance through automation. Before expensive equipment and new procedures are introduced, a survey of the electrocardiology department's functions and procedures can lead to important insights.

Depression among incarcerated delinquents.

The authors examined the prevalence of depression among incarcerated delinquents and nonincarcerated, nondelinquent adolescents and reported a prevalence of 18% and 4%, respectively. The possible effect of incarceration on the development of depression was also studied. DSM-III diagnostic criteria for major depressive disorders were used.

Ionic strength and counterion repulsion as factors in the behavior of polyions in orienting electric fields.

The effect of counterion-counterion repulsion on the orientation of DNA, a polyion of high charge density is examined by electric-field orientation experiments. The charge species of the counterion and the ionic strength effect the orientation in a manner consistent with a theoretical treatment of the polarization of high charge density polyelectrolytes in terms of the effect of the applied field on the equilibrium distribution of condensed counterfoils on the polyion.

Limiting laws and counterion condensation in polyelectrolyte solutions. V. Further development of the chemical model.

Counterion binding to polyelectrolyte chains is formulated as a chemical reaction Mz (free) leads to Mz (bound). Expressions for the chemical potentials of free and bound counterions are set equal to obtain the reaction equilibrium. The results are equivalent to those in the previous paper of this series.