Sea blue histiocytosis in a patient with chronic non-neuropathic Niemann-Pick disease.

A patient with Niemann-Pick disease is reported together with family studies. Her liver and bone marrow were shown to be infiltrated with sea blue histiocytes. Other organs, spleen and lung, were presumably also involved but histological proof was not obtained. Enzyme assay of leucocytes, lymphocytes, and cultured skin fibroblasts showed the patient to be deficient in sphingomyelinase activity. In fibroblasts, activity was 5% of normal while for the parents activity was about 50% of normal. The expected partial deficiency was not found using leucocytes or lymphocytes from the parents. Heat stability studies on fresh fibroblast extracts from the propositus indicated that residual sphingomyelinase activity was slightly more labile than that of the controls. It seems clear that chronic Niemann-Pick disease without neurological involvement is associated with sea blue histiocytosis.     

Accuracy of algorithms for detection of atrial fibrillation from short duration beat interval recordings

Atrial fibrillation (AF) is characterised by highly variable beat intervals. The aims of the study were to assess the accuracy of AF detection algorithms from short analysis durations and to validate prospectively the accuracy on a large community-based cohort of elderly subjects. Three algorithms for AF detection were evaluated: coefficient of variation (CV), mean successive difference (Δ) and coefficient of sample entropy (COSEn), using two databases of beat interval recordings: 167 recordings of 300 s duration for a range of rhythms acquired in a hospital setting and 2130 recordings of 10 s duration acquired in the community. Using the longer recordings receiver operating characteristic (ROC) analysis was used to identify optimal algorithm thresholds and to evaluate analysis durations ranging from 5 s to 60 s. An ROC area of 93% was obtained at recording duration of 60 s but remained above 90% for durations as low as 5 s. Prospective analysis on the 2130 recordings gave AF detector sensitivities from 90.5% (CV and Δ) to 95.2% (COSEn), specificities from 89.3% (Δ) to 93.4% (COSEn) and accuracy from 89.3% (Δ) to 93.4% (COSEn), not significantly different to those obtained on the initial database. AF detection algorithms are effective for short analysis durations, offering the prospect of a simple and rapid diagnostic test based on beat intervals alone.     

Ventricular performance and prognosis after primary ventricular fibrillation complicating acute myocardial infarction

To examine the relationship between early arrhythmias, infarctsize and prognosis, we compared 22 consecutive patients survivingacute myocardial infarction (AMI) and primary ventricular fibrillation(VF) with a control population after AMI uncomplicated by primaryVF. Left ventricular ejection fraction (EF) was measured byradionuclide ventriculography before discharge from hospital.Mean EF was significantly reduced below normal following AMIwith or without primary VF (normal 0.57±0.05, mean±SD;P<0.01). Mean EF was lower among patients who survived primaryVF than among those with infarction uncomplicated by primaryarrhythmia (0.33 ±0.12 v. 0.46 ±0.07; P<0.01).There were striking differences in EF between those patientswith anterior and those with inferior infarction. Mean EF forthose surviving primary VF after transmural anterior infarction(0.23±0.06) was lower than those who had primary VF aftertransmural inferior infarction (0.43±0.06; P<0.01J.Normal left ventricular function was seen in four individualswho developed no further complications. Recurrent primary ventriculararrhythmia was seen v only in those individuals subsequentlyshown to have reduced EF. Low EF (< 0-35) was seen in 12patients with primary VF in the context of anterior infarction,five developed breakthrough ventricular arrhythmias despitetherapy and in a limited follow-up period, three have died.     

Assessment of computer customized brackets and positioning jigs

An in-practice assessment of Ormco's CAD CAM Insignia Orthodontic system is reviewed Investigation included an in-vitro and in-vivo analysis of the accuracy of bracket placement, and measurement of the accuracy of slot and torque manufacturing specifications were addressed. The possible role of these systems in general dental practice is discussed. Examination of the Insignia system has led us to believe that changes in the way that orthodontic cases are being planned, treated, and delivered to the patient are changing with the increased use of computer technology. The ability to customize brackets and wires for the individual tooth in the individual patient should lead to better and easier finishing.     

Theoretical model of critical issues in informed consent in HIV vaccine trials

The informed consent process (ICP) for HIV vaccine trials poses unique challenges and would benefit from improvements to its historically based structure and format. Here, we propose a theoretical framework that provides a basis for systematically evaluating and addressing these challenges. The proposed framework follows a linear pathway, starting with the precondition of voluntariness, three main variables of valid decision-making (competency, provision of information and understanding) and then the consequential outcome of either refusal or consent to participate. The existing literature reveals that culturally appropriate provision of information and resultant understanding by the vaccine trial participant are among the most significant factors influencing the authenticity of valid decision-making, though they may be overridden by other considerations, such as individual altruism, mistrust, and HIV-related stigma. Community collaborations to foster bidirectional transmission of information and more culturally tailored consenting materials, therefore, represent a key opportunity to enhance the ICP. By providing a visual synopsis of the issues most critical to IC effectiveness in a categorical and relational manner, the framework provided here presents HIV vaccine researchers a tool by which the ICP can be more systematically evaluated and consequently improved.