Concurrent mapping of brain sites for sensitivity to the direct application of morphine and focal electrical stimulation in the production of antinociception in the rat

The effect of morphine microinjection (5 microgram/0.5 microliter) and focal electrical stimulation on the animal's response to radiant heat and noxious pinch was studied concurrently at 117 brain loci extending from the medial thalamus caudally to the periaqueductal gray area (PAG). Three populations of brain sites were discernible based on their responsiveness to focal electrical stimulation and morphine microinjection in the production of antinociception: (a) sites which support stimulation-produced analgesia (SPA, n = 24), (b) sites which were sensitive to the direct application of morphine (n = 8), (c) sites responsive to both manipulations (n = 8). With a few exceptions, all morphine sensitive sites were located within the anatomical boundaries of the PAG while sites supporting SPA were located not only within the PAG but also in the brain regions peripheral to this structure. Sites responsive to both manipulations were generally distributed throughout thf lateral aspect of the posteroventral PAG. Stimulation strength-effect curves for sites subserving SPA were also obtained. No differences were discovered between curves obtained from morphine-sensitive and -insensitive brain loci.     

A study of thyroid disease in family practice

Thyroid disease is relatively common in family practice, yet is often undiagnosed or poorly managed. This study examines several aspects of thyroid disease in a large, semirural family practice setting and exemplifies the type of practical clinical research that can be done in family medicine. An overall prevalence of approximately one percent was determined for thyroid disease in this practice. In a series of 85 patients, the ratio of hypothyroidism:hyperthyroidism:euthyroid goiter was 9:2:1 respectively. Initial signs and symptoms recorded for these patients conformed closely to the findings in other large series. Eighty percent of the patients with idiopathic hypothyroidism never had enlarged glands, whereas 100 percent of the patients with hypothyroidism associated with Hashimoto's thyroiditis had enlarged glands. Laboratory aids such as serum thyroid stimulating hormone (TSH), anti-thyroid antibodies, and radioactive iodine uptake (RAIU) and scans were inadequately utilized. Medical and/or surgical consultation was obtained in 17.5 percent of patients with hypothyroidism, 80 percent of patients with hyperthyroidism, and 63 percent of those with euthyroid goiter. Currently 95 percent of the hypothyroid patients and 100 percent of the hyperthyroid patients are euthyroid.     

Intracranial hemorrhage in achondroplasia

The neurological manifestations of achondroplasia include megalencephaly, hydrocephalus, and progressive myelopathy or radiculopathy secondary to spinal stenosis. Subarachnoid and intracerebral hemorrhage have not been previously reported in association with achondroplastic dwarfism. This report describes two patients with achondroplasia who have died secondary to intracranial hemorrhage. At autopsy, the source of hemorrhage was found to be an arteriovenous malformation of the choroid plexus in one case and a ruptured aneurysm of the left middle cerebral artery in the other.     

Circulating N-terminal atrial natriuretic peptide as a marker for symptomless left-ventricular dysfunction

Early identification of patients with symptomless left-ventricular dysfunction and early pharmacologic intervention may have an impact on the outlook of patients with heart failure. Atrial natriuretic peptide (ANP) is a cardiac hormone that is released as a C-terminal (C-ANP) and an N-terminal peptide (N-ANP). Since N-ANP has reduced clearance rates compared with C-ANP, N-ANP circulates at higher concentrations. Based on the known increased concentration of C-ANP in symptomatic congestive heart failure, our study was designed to evaluate prospectively N-ANP profile and left-ventricular function in subjects with symptomless and symptomatic heart failure, and the role of plasma N-ANP as a marker for early identification of patients with heart failure. 180 patients who were referred for rest and exercise radionuclide angiography for evaluation of left-ventricular function were studied. Blood was taken for measurement of C-ANP and N-ANP before angiography. Patients were grouped according to New York Heart Association (NYHA) heart failure classification and left-ventricular function. Mean (SD) plasma N-ANP concentration in patients with symptomless left-ventricular dysfunction (NYHA class I, n = 70) was 243 (256) pmol/L (range 27-922 pmol/L), and was higher (p < 0.001) than in 25 control subjects (28 pmol/L). A plasma N-ANP concentration above 54 pmol/L (mean +/- 1.96SD of the control group) had a sensitivity of 90% and a specificity of 92% for detection of patients with symptomless left-ventricular dysfunction. We have shown that plasma N-ANP concentrations are significantly increased in patients with symptomless left-ventricular dysfunction and that this peptide can serve as a marker for diagnosis of such patients.     

Long-term sealing efficacy of four root surface sealing materials used in endodontic leakage studies

Fifty extracted human maxillary anterior teeth were biomechanically instrumented and divided into five equal groups, four experimental and a control. The teeth in the experimental groups had their root surface coated with one of four sealants; epoxy, casting resin, sticky wax, or nail polish. The roots of the remaining teeth were not coated and served as controls. All of the teeth were mounted in the caps of scintillation vials. Five microliters of [3H]uridine were deposited in the root canal space and disintegration counts were obtained over time periods of 1, 4, 8, 12, and 36 wk. At the conclusion of the experiment, sticky wax was demonstrated to provide a superior seal (p < 0.0001).