Choristomas of the seventh and eighth cranial nerves.

Choristomas, masses of normal tissues in aberrant locations, contain smooth muscle fibers and fibrous tissues. We describe the MR imaging features of two choristomas located in the internal auditory canals and arising from the facial and vestibulocochlear nerves. Both lesions enhanced with contrast material. In one case, enhancement was seen in the geniculate ganglion and greater superficial petrosal nerve. In the other, a medial component enhanced less than the lateral component did.     

The impact of sequential quality assessment exercises on laboratory performance: the multicentre ECAT Angina Pectoris Study. Report from the European Concerted Action on Thrombosis and Disabilities (ECAT)

As an adjunct to a European multicentre prospective study, five quality assessment (QA) exercises, spanning a period of 2.5 years, were undertaken. In these, fifteen laboratories from eight countries each performed ten haemostatic factor assays. The design of the QA exercises allowed the between-duplicate, between-day and between-laboratory coefficients of variation (CVs) to be calculated. The between-duplicate CV decreased by a factor of one quarter, and the between-day CV by a factor of one third, over the five exercises. The activated partial thromboplastin time (APTT) assay consistently showed the lowest CVs, while there was notable improvement in the between-day CVs for von Willebrand factor related antigen (vWF R:Ag) and factor VIII clotting activity (VIII:C). However, the between-laboratory CV, assessing extent of agreement between the different laboratories, did not apparently improve over the five exercises. Thus, while QA exercises may be very useful in improving the performance of haemostatic assays according to criteria which an individual laboratory can assess, improving agreement on haemostatic assay results between laboratories may be more difficult to achieve.     

Teaching behavioral medicine using individual coronary heart disease risk factors

Two hundred twenty-one first-year medical students participated in a voluntary coronary heart disease risk factor self-change project designed to teach the principles of behavioral change. Blood pressure, serum lipids, percentage body fat, cardiovascular fitness, and smoking status were measured prior to the project. Students designed their own programs of behavior modification and, after 8 weeks, repeat measurements were obtained in students whose projects related to coronary heart disease risk (56% of entire group). Despite generally low initial coronary heart disease risk factors, most risk factor groups successfully altered the targeted risk factors. The subgroup attempting to lower serum cholesterol (n = 49) reduced total cholesterol 15 +/- 24 mg/dl (mean +/- SD) and low-density lipoprotein cholesterol 11 +/- 20 mg/dl (P less than 0.001 for both). The blood pressure group (n = 9) decreased systolic blood pressure 8 +/- 10 mm Hg (P less than 0.05), and the weight-loss group (n = 33) lost 3.0 +/- 2.9 kg (P less than 0.001), reducing estimated percentage body fat 1.7 +/- 1.8 (P less than 0.001). The self-change project was well received by the students and appears to be a useful technique for introducing the principles of behavioral medicine to first-year medical students.     

A negative correlation between the induction of long-term potentiation and activation of immediate early genes.

In the present study we examined the relationship between the induction of long-term potentiation (LTP) in the dentate gyrus of anesthetized rats and activation of immediate early genes (IEGs; c-fos and zif/268) using several different high-frequency stimulation paradigms. Stimulation parameters that effectively induced LTP were not associated with IEG activation. Conversely, stimulation parameters that failed to induce LTP consistently resulted in IEG activation. These results suggest that there is a negative correlation between IEG activation and LTP, and that activation of IEGs is neither necessary nor sufficient for the induction of LTP.     

Behavioral state-specific changes in human hippocampal theta activity

Although there has been extensive examination of the behavioral and physiologic correlates of hippocampal theta activity in animals, the human literature consists of a single case study. We investigated the differential effects of four behavioral states on human hippocampal theta activity in 16 epilepsy surgery patients. Behavioral conditions included resting eyes closed (RC), resting eyes open (RO), eyes open with auditory word activation (AW), and eyes open with visuospatial activation (VS). Hippocampal theta activity decreased during both RO and VS compared to both RC and AW. There were reciprocal changes in delta activity. Comparisons of RO to VS and of RC to AW were nonsignificant. The results demonstrate state-specific changes in human hippocampal theta and are consistent with the animal literature that relates hippocampal theta to sensorimotor integration and forebrain volitional mechanisms.