Diagnostic reliability of radionuclide ventriculography in detecting left ventricular hypertrophy. Echocardiographic and ECG correlations.

Left ventricular hypertrophy (LVH) is frequently present in patients referred for radionuclide ventriculography (RVG) for evaluation of left ventricular function. During interpretation of these studies, the nuclear medicine physician may have the subjective impression that increased septal thickening is present because of the abnormally prominent separation of the right and left ventricular blood pools. To examine the diagnostic reliability of this finding, we retrospectively reviewed the RVG studies of 43 consecutive patients and correlated the finding of subjectively increased septal thickness with established echocardiographic (ECHO) criteria and commonly used electrocardiographic (ECG) indices of LVH. Using standard ECHO measurements of septal thickness as a gold standard, RVG interpretation of septal thickening demonstrated a sensitivity of 0.69, specificity of 0.70, and accuracy of 0.70. When compared with standard ECG criteria for LVH, RVG performed quite favorably in the diagnosis of LVH confirmed by ECHO left ventricular mass index. We conclude that scintigraphic evidence of LVH should be reported when RVG studies are interpreted.     

Hg-provocation of oral mucosa in patients with oral lichenoid lesions

Five amalgam-bearing patients, with clinically and histologically confirmed oral lichenoid lesions, were tested by applying 0.5% Hg in petrolatum for 10 min to clinically normal mucosa. Control sites were exposed to petrolatum only. Four amalgam-bearing patients with no clinical evidence of oral lichenoid lesions served as controls; they were subjected to similar Hg and petrolatum exposure. After 24 h, biopsies were taken and immunocytochemically analyzed with monoclonal antibodies to lymphoid and nonlymphoid cells. No distinct differences could be detected between the Hg-exposed areas of the lichen patients and those of the nonlichen patients. Furthermore, normal mucosa exposed to petrolatum only showed a staining pattern in the lichen patients which was no different from the nonlichen patients. The findings are discussed with respect to possible mechanisms of development of lichen-like lesions in oral mucosa.     

Influence of anoxia on glucose metabolism in pancreatic islets: Lack of correlation between fructose-1,6-diphosphate and apparent glycolytic flux

Summary When equilibrated with O₂-CO₂ (95:5), pancreatic islets of non-inbredob/ob-mice exhibited a sigmoidal dependence of³H₂O production on D-(5-³H)-glucose concentration; the rate was most sensitive to changes of glucose concentration around 5mM and tended to be maximum above about 15 mM glucose.³H₂O production from more than 5 mM D-(5-³H)-glucose was about twice as fast as the production of¹⁴CO₂ from equimolar D-(U-¹⁴C)-glucose. Islets equilibrated with N₂-CO₂ (95:5) did not exhibit a sigmoidal dose-response curve for³H₂O production, the process being inhibited by anoxia at glucose concentrations above 5mM. Pieces of exocrine pancreas had a slower aerobic³H₂O production than the islets and showed a clear enhancement of the process during anoxia. In comparison with oxygenated islets, anoxic islets exhibited decreased concentrations of glucose-6-phosphate and increased concentrations of fructose-l,6-diphosphate. The concomitant inhibition of glycolytic flux may be due to a low lactate dehydrogenase activity in islets yielding a slow reoxidation of NADH and a slow phosphoglyceraldehyde oxidation under anaerobic conditions.     

Left and right ventricular function in inferior acute myocardial infarction and significance of advanced atrioventricular block

Of 139 consecutive patients with a first inferior acute myocardial infarction, 26 (19%) had advanced atrioventricular (AV) block and 113 (81%) did not. All were evaluated by 2-dimensional echocardiography (2-D echo) and radionuclide angiography. Patients with advanced AV block had lower radionuclide left ventricular (LV) ejection fraction (51 +/- 10 vs 58 +/- 11%, p less than 0.01), higher LV wall motion score on 2-D echo (5.6 +/- 2.6 vs 3.1 +/- 2.7, p less than 0.001), lower radionuclide right ventricular (RV) ejection fraction (32 +/- 15 vs 39 +/- 16%, p less than 0.001) and higher RV wall motion score on 2-D echo (3.4 +/- 1.7 vs 1.5 +/- 2, p less than 0.002) than did patients without AV block. The incidence rate of RV dysfunction was higher in patients with advanced AV block (78 vs 40%, p less than 0.02), and the mortality rate was also higher (although not significantly) in patients with advanced AV block (15 vs 6%). In conclusion, patients with inferior acute myocardial infarction and advanced AV block have larger infarct sizes (as seen on radionuclide angiography and 2-D echo) and lower RV and LV function than patients without AV block. This finding may explain the higher mortality rate observed in this group.     

Active site of tripeptidyl peptidase II from human erythrocytes is of the subtilisin type

The present report presents evidence that the amino acid sequence around the serine of the active site of human tripeptidyl peptidase II is of the subtilisin type. The enzyme from human erythrocytes was covalently labeled at its active site with [3H]diisopropyl fluorophosphate, and the protein was subsequently reduced, alkylated, and digested with trypsin. The labeled tryptic peptides were purified by gel filtration and repeated reversed-phase HPLC, and their amino-terminal sequences were determined. Residue 9 contained the radioactive label and was, therefore, considered to be the active serine residue. The primary structure of the part of the active site (residues 1-10) containing this residue was concluded to be Xaa-Thr-Gln-Leu-Met-Asx-Gly-Thr-Ser-Met. This amino acid sequence is homologous to the sequence surrounding the active serine of the microbial peptidases subtilisin and thermitase. These data demonstrate that human tripeptidyl peptidase II represents a potentially distinct class of human peptidases and raise the question of an evolutionary relationship between the active site of a mammalian peptidase and that of the subtilisin family of serine peptidases.     

Studies of Antigens Associated With Hodgkin's Disease

Following a previous preliminary report, this study was initiated to demonstate further evidence of tumor-associated antigens in Hodgkin’s diseaseand to determine if these antigens arefound in other pathologic states.Tumor-associated antigens are nowdemonstrated by three techniques in18 Hodgkin’s invoved spleens and arenot found to be present in equal concentration in normal spleens. Usingimmunofluorescence techniques andabsorbed tumor antisera, fluorescenceis demonstrated in tumors but not inthe normal region of the same tumor-bearing spleen or in normal spleens.Gel diffusion with absorbed tumor antisera revealed a common precipitinband in Hodgkin’s disease not presentin normal spleens or spleens fromother diseases. Studies with immunoelectrophoresis have demonstratedtwo antigens present in the tumorsin the spleen. Eighteen out of 19 Hodgkin’s tumors from the spleen have suchantigens identifiable by immunoelectrophoresis with concomitant negativenormal splenic controls in each case.Five out of 18 spleens from other disease states shared one of the antigens.These data confirm the presence ofcommon tumor-associated antigens inHodgkin’s disease, and it is postulated that at least one antigen may bea host cell reactant substance.

Submitted on February 7, 1972 Revised on June 5, 1972 Accepted on June 7, 1972     

Changes in estradiol and cortisol production rates in men under the influence of narcotics.

The production rates of estradiol and cortisol in two male opiate addicts while on narcotic maintenance, were in the low normal or subnormal range. There was a sharp several-fold increase upon withdrawal with a subsequent fall to normal values after a period of abstinence. The changes in estradiol production rates were proportionally greater than those of cortisol and suggest that they were due to changes in testicular secretion of the precursor testosterone.