Ventricular premature beats: screening and induction tests in normal men

Effective future research on the significance of ventricular premature beats (VPB) and their therapeutic suppression require improved and simpler methods for arrhythmia detection, characterization, and measurement. This study considers the comparative yield, repeatability, and validity of several methods of VPB detection and induction in a sample of the general population of middle-aged men. Isometric exercise inducers VPB. Treadmill exercise both induces and suppresses VPB. Cartotid sinus pressure and cold stress provide a small extra yield of VPB.

Thalamic projections to area 17 in a prosimian primate, Microcebus murinus

Electrophysiological recording of single neurons was used to describe the representation of visual space in area 17, and the technique of retrograde transport of horseradish peroxidase (HRP) was applied to relate these results to projections from the thalamus in the prosimian primate Microcebus murinus. The visuotopic organization of area 17 was found to resemble that of other primates. On the dorsal surface, the border of area 17 corresponds to the representation of the vertical meridian. Proceeding medially across the surface the location of receptive fields descends along the vertical meridian, while moving caudally receptive fields progress temporally. Most of the dorsolateral surface is devoted to central vision and corresponds to a well developed area centralis. Following HRP injections in striate cortex, columns of labeled cells were found in the dorsal lateral geniculate (dLGN) extending orthogonally across all six layers. These columns run in a general ventrodorsal and caudorostral direction, parallel to a line connecting the cellular discontinuities corresponding to the optic disc. These discontinuities are present in magnocellular layer 1 and parvocellular layers 5 and 6, thus receiving from the nasal retina of the contralateral eye. The representation of the vertical meridian is situated in the ventromedial portion of the dLGN, and the monocular field is represented in the dorsal extremity. Anterior dLGN projects to the calcarine fissure (lower field) and posterior dLGN projects to the ventral surface of the cortex (upper field). Extrageniculate input to area 17 was found to originate from the pulvinar. HRP labeled cells were located in two distinct divisions of this nucleus, the cytoarchitecture of which is described. In addition, projections to occipital cortex were found to arise from the intralaminar nuclei.

Ventricular premature contractions: a randomized non-drug intervention trial in normal men

The influence of a 6-week intervention on factors thought to be related to ectopic cardiac rhythms was tested in normal men with frequent ventricular premature contractions (VPCs), using a randomized, controlled and partial crossover design. The VPC intervention trial experimental regimen included total abstinence from caffeine and smoking, reduction of alcohol intake, and a physical conditioning program. Effects were studied in detail among 81 healthy men with persistent VPCs. VPCs were measured during standard states of rest, dynamic and isometric exercise and other stresses, and 24-hour ambulatory monitoring. Adherence to the treatment was excellent. The experimental group achieved more than 80% of activities asked of them, and little "contamination" occurred in the control group. VPCs were analyzed according to VPC/min, VPC/man and VPC/total number of heart beats. Moderate changes in VPC rates occurred in both experimental and control groups but no significant group differences were found at rest or during any induction test. This 6-week, multiple-factor "hygienic" intervention program had no significant influence on the frequency or occurrence of VPCs in apparently normal men with persistent and frequent VPCs. Because the mechanisms and the significance of VPCs are different in patients with ischemic heart disease, our approach and methods may be useful for similar trials among cardiac patients of adjunct or non-drug therapy for ectopic rhythms.

The role of insight in child analysis: a developmental viewpoint

I have traced a developmental line for the capacity for insight. The conclusions reached are based on psychoanalytic material gathered from treatment cases at the Hampstead Clinic over the past 25 years. I have elaborated on the relevance these conclusions have to techniques employed in the analysis of children.

Direct projections from thalamic intralaminar nuclei to extra-striate visual cortex in the cat traced with horseradish peroxidase

Thalamic projections to the visual cortex were investigated using the Horseradish peroxidase tracing technique. Besides confirmation of a distinct origin of thalamic projections to striate and extra-striate visual cortex, afferents of the intralaminar nuclei (ILN) to visual cortex were demonstrated. These projections of ILN were shown to be specific in that they terminate in areas 18, 19 and Clare Bishop but not area 17. The coupling of these intralaminar projections on to the extra-striate visual system is considered with respect ot orientation of gaze.

Comparison of selective media for the isolation of salmonellae

A study of the selective action of four fluid media used for the isolation of salmonellae is described. When incubated in the presence of three competing organisms, test strains were recovered most frequently from Rappaport medium but mannitol selenite broth proved superior for the isolation of S. typhi.