Changes of the intramyocardial electrogram after orthotopic heart transplantation.

Heart transplantation, including conventional immunosuppression, has allowed the use of the surface electrocardiogram to detect allograft rejection. With the use of cyclosporine this parameter is no longer sensitive, but voltage of the intramyocardial electrogram has correlated repeatedly with rejection. From July 1983 through February 1986, 98 patients had heart transplantation; 13 of those patients had a telemetry pacemaker simultaneously implanted.

Effects of previous myocardial infarction on measurements of reactive hyperemia and the coronary vascular reserve.

The measurement of coronary vascular reserve by the reactive hyperemic response to ischemia has been advocated as a practical method of assessing the physiologic significance of coronary stenoses. Because the concept of measuring coronary blood flow during maximal vasodilation assumes a normal arteriolar network and viable myocardium, the presence of previous myocardial infarction may cause a significant decrease in the coronary reserve unrelated to the severity of a coronary stenosis itself. To determine the potential importance of this effect, rest and hyperemic coronary blood flow were measured in 14 dogs in the regions subtended by the left anterior descending and left circumflex coronary arteries.

Hypothalamic paraventricular nucleus stimulation-induced gastric acid secretion and bradycardia suppressed by oxytocin antagonist.

Unilateral microstimulation of the medial parvocellular division of the hypothalamic paraventricular nucleus (PVNmp) elicits significant increases in gastric acid secretion and bradycardia. An injection of 25 picomoles of the oxytocin antagonist dET2Tyr(Et)Orn8 Vasotocin (ETOV), suspended in 5 nanoliters of artificial of cerebrospinal fluid (CSF), into the dorsal motor nucleus of the vagus (DMN) immediately preceding microstimulation of the PVNmp suppresses this change in gastric acid secretion and heart rate. The injection of an equal volume (5 nanoliters) of artificial CSF vehicle solution into this region of the DMN, prior to PVNmp microstimulation, has no effect on either the subsequent stimulation-evoked changes in acid secretion or cardiac activity.

CT evaluation of the greater sciatic foramen in patients with sciatica.

Sciatic and lower extremity neurologic symptoms may be from pathologic involvement of the sacral plexus or sciatic nerve in the region of the greater sciatic foramen. Twenty-five patients were reviewed who presented consecutively over a 4 year period with sciatic symptoms secondary to pathologic changes in the greater sciatic foramen. Malignant neoplasm alone (18 patients) and malignant neoplasm associated with infection (two patients) account for most of these cases.

Comparison of thyrotropin assays by relative operating characteristic analysis.

We compared two versions of a commercial double-site immunoradiometric assay for human thyrotropin, one of them claimed to show superior ability in apportioning euthyroid and hyperthyroid populations. Relative operating characteristic (ROC) analysis permits the calculation of the area under the ROC curve as an unbiased unit measure of diagnostic validity, and also yields an optimal decision point for separating the two populations, based on relative prevalences and locally perceived utilities of test outcomes. We examined 48 hyperthyroid and 50 euthyroid subjects with the original assay and with a later version from the same manufacturer and conclude that the latter demonstrates a small but significant superiority in diagnostic performance throughout the clinical range of interest.

Computed tomography and ultrasonography of the hemophilic pseudotumor and their use in surgical planning.

Twenty-one hemophilic pseudotumors in 17 patients were evaluated radiologically to facilitate surgical planning. Plain radiography, angiography, intravenous urography, computerized tomography (CT), and ultrasonography (U/S) were the modalities used. CT proved to be the most efficient method in the detection of bone destruction and soft tissue lesions including additional daughter cysts.

Brucellosis: serological methods compared.

At least 12 persons contracted clinical, and 4 persons subclinical Brucella melitensis infection during a brucellosis epidemic in the spring and summer of 1983 in Southern Germany, a region which had been free of this disease for the past 20 years. All cases of illness were traced to one infected herd of sheep. The presence of antibodies against B.

Gastric-vagal solitary neurons excited by paraventricular nucleus microstimulation.

Electrophysiological studies were performed to determine whether neurons of the nucleus of the solitary tract (NST) which receive sensory input from the stomach via vagal afferents are activated by microstimulation of the medial parvocellular division of the paraventricular nucleus of the hypothalamus (PVHmp). We found that 37% of the NST neurons orthodromically activated by gastric vagal nerve stimulation are also orthodromically excited by PVHmp microstimulation. Not only do these NST neurons receive convergent input from the PVHmp as well as gastric afferent input (vagal), but this input from the PVHmp may also bias the responsiveness of these NST neurons to incoming afferent information.

Computed tomography of solitary spinal osteochondromas.

Solitary osteochondromas rarely occur in the axial skeleton. These benign tumors may cause a variety of symptoms while remaining difficult to recognize by plain radiographic and myelographic studies. We present three cases of solitary osteochondromas of the spine and demonstrate the CT findings of these unusual tumors.

Dorsal medullary oxytocin, vasopressin, oxytocin antagonist, and TRH effects on gastric acid secretion and heart rate.

Injections of oxytocin and TRH (11 picomoles), centered on the dorsal motor nucleus of the vagus, substantially increased gastric acid secretion. Additionally, oxytocin, but not TRH, simultaneously produced a consistent reduction in heart rate. Vasopressin injected into the same locus, at doses of 11 and 110 picomoles, had no effect on either function.

Vagal afferent stimulation-evoked gastric secretion suppressed by paraventricular nucleus lesion.

Studies were performed to evaluate the possibility that the paraventricular nucleus (PVN) of the hypothalamus modulates gastric acid secretion by changing the sensitivity of the gastric secretory control mechanism to vagal afferent input. Under pentobarbital anesthesia, 17 rats were prepared with esophageal and pyloric catheters such that the stomach could be perfused continuously on a flow-through basis. Thus, acid secretion could be monitored throughout the experiment.

Convergence of vagal and gustatory afferent input within the parabrachial nucleus of the rat.

Our previous anatomical and electrophysiological studies demonstrated that first-order hepatic and gustatory afferents project to separate regions of the solitary nucleus (NST) and no intra-NST interaction of these two sensory systems could be demonstrated. However, iontophoretic injections of horseradish peroxidase into physiologically identified zones of the NST revealed that both of these regions send overlapping projections to the immediately subjacent parvocellular reticular formation as well as the postero-medial parabrachial nucleus (PBN). The present electrophysiological studies demonstrate that an interstitial zone of neurons in the caudal, medial PBN, indeed, receive convergent input from second-order gustatory and vagal afferents.

A new vascular clamp.

A new vascular clamp called the occluder pad is described. It has significant utility when used in a variety of anatomic sites in either normal or diseased vessels. It possesses suitable tractive and occlusive forces while minimizing the mechanical forces applied to the vessel walls.

Chondrosarcoma of the spine: an unusual radiographic presentation.

Chondrosarcoma is a primary malignant tumor arising rarely in the axial skeleton. It usually presents as a destructive lesion with diffuse mottled calcification. We report three patients with chondrosarcoma of the spine.

[Role of x-ray computed tomography in infectious spondylodiscitis. A review article].

The importance of computed tomography (CT) in the diagnosis of infectious spondylitis is reviewed on the basis of the currently available literature and our updated experience. The etiology and pathogenesis of the various types of presentation is briefly discussed. CT is an excellent non-invasive modality offering easy evaluation of the intra and extraosseous extent of the lesion, guidance to biopsy and in following therapeutic results.

The relationship of instrument parameters to performance within a survey peer group.

Using simulators of transmission imaging, an interlaboratory survey assessed the discriminatory performance of 86 subscribers, each of whom imaged a liver phantom in anterior and right lateral projections. Analysis was by receiver operating characteristic (ROC) with Az, the area under the ROC curve, used as a measure of accuracy unconfounded by decision bias. Az values were then defined as the dependent variable in a statistical model that related performance to several instrument design and operating parameters.