Measurement of hydraulic pressure on the sinus membrane for safer control during transcrestal sinus lifting.

The aim of this study was to determine the hydraulic pressures necessary to separate and lift the sinus membrane from the sinus floor in order to ensure a more controlled and safer hydraulic transcrestal sinus lifting surgery and prevent sinus membrane perforation. A flow-regulating hydrodynamic device with a pressure sensor was used in nine patients. The hydraulic pressure was found to increase steadily up to a mean peak of 25.0±13.0kPa, which is comparable to the medium suction power of ordinary vacuum cleaners. Subsequently, there was a short plateau followed by a sharp decrease in the hydraulic pressure.

Percutaneous transluminal coronary angioplasty of a coronary artery with a total occlusion.

Percutaneous transluminal coronary angioplasty has become an accepted therapeutic modality for patients with coronary artery disease. Until the present, its use has been restricted to vessels that are subtotally obstructed. We recently successfully utilized coronary angioplasty in a patient with a totally occluded coronary artery. The experience is described and criteria proposed for the selection of patients with totally obstructed coronary arteries for coronary angioplasty.

Impaired cleavage of the joint gag-pol polyprotein precursor and virion assembly in a temperature-sensitive mutant of Rous sarcoma virus.

A temperature-sensitive coordinate mutant tsLA83 of Prague (PR-B) strain of Rous sarcoma virus at the nonpermissive temperature (41 degrees) produces noninfectious virus particles (NI-LA83) which contained only 3% of the reverse-transcriptase activity present in infectious virions. Analyses of [35S]methionine-labeled NI-LA83 showed the presence of all of the viral proteins except reverse transcriptase. Pulse-chase analyses of the virus-specified proteins in cells infected with LA83 or PR-B showed that the gag and glycoprotein precursors, Pr76gag and gPr95env, respectively, were processed at both 35 and 41 degrees. The reverse-transcriptase precursor, Pr180gag-pol, however, was not processed in LA83-infected cells at 41 degrees. In contrast, cells infected with LA83 or PR-B at 35 degrees as well as with PR-B at 41 degrees showed normal cleavage of Pr180gag-pol. A shiftdown of LA83-infected cells at 41 degrees to the permissive temperature 35 degrees resulted in the normal processing of Pr180gag-pol and production of infectious virus containing reverse transcriptase. Electron microscopic analysis showed that at 41 degrees cells infected with LA83 showed a large number of budding structures but fewer released particles. A shiftdown from 41 to 35 degrees resulted in an increase of virus particles with a concomitant decrease in budding structures suggesting that the processing of reverse-transcriptase precursor is related to virion assembly.

Electrophysiologic effects of encainide following acute coronary occlusion in dogs.

Encainide, a benzanilide derivative, is a local anesthetic antiarrhythmic drug. To determine its effects on infarcted and normal tissue in situ, we infused encainide (1.0 mg/kg) for 15 min intravenously followed by 0.01 mg/kg/min for an additional 105 min in 8 adult open-chest, pentobarbital-anesthetized, atrially paced dogs after left anterior descending coronary occlusion. We monitored plasma concentration, blood pressure, and surface electrocardiogram (ECG). We determined conduction intervals from the onset of the QRS in the limb lead ECG to the major deflection of bipolar electrograms recorded in the infarcted and normal zones. We found that the blood pressure did not change significantly. Encainide did significantly prolong the atrial stimulus artifact-to-QRS interval and the QRS duration, as previously reported, and also prolonged intraventricular conduction intervals. In the infarcted zone, the drug prolonged conduction in both subendocardium and subepicardium, and prolongation was of somewhat greater magnitude in this zone than in the normal zone. Encainide prolonged the effective refractory period only in the infarcted zone (19 +/- 5 msec at peak; p less than 0.01). The above electrophysiologic effects may explain in part the previously demonstrated antiarrhythmic properties of this drug.

Left main coronary artery aneurysm following percutaneous transluminal angioplasty: a report of a case and review of the literature.

Since its introduction in 1977, the number of PTCAs and its indications have grown. Along with more frequent usage, newer complications have been reported. Aneurysm of left main coronary artery is rare. This report describes the formation of a new non-obstructing aneurysm in the left main coronary artery after PTCA of left circumflex artery. The patient has had 7 yr of follow-up with a benign clinical course.

Mandibular chloroma demonstrated by magnetic resonance imaging.

A case of chloroma or granulocytic sarcoma in the mandible of a young child is presented with magnetic resonance imaging (MRI) features.

Adipocyte P2 gene: developmental expression and homology of 5'-flanking sequences among fat cell-specific genes.

We have isolated the mouse gene encoding adipocyte P2, aP2, the differentiation-dependent adipocyte protein homologous to myelin P2. The aP2 gene is present in a single copy in the mouse and is present in single or few copies in species from human to Drosophila. The entire gene spans 4 kilobases and consists of four exons encoding 25, 57, 34, and 16 amino acids; the overall exon structure is similar to the gene encoding liver fatty acid binding protein. A plasmid vector was constructed containing the entire aP2 gene with flanking sequences, modified by linker insertion. When this gene is stably introduced into 3T3-F442A cells, it is expressed only upon adipose differentiation, with a time course of induction very similar to that of the endogenous aP2 gene. We have compared the DNA sequence of the 5'-flanking region of the aP2 gene to the promoter regions of two other genes activated during adipocyte differentiation, glycerol-3-phosphate dehydrogenase and adipsin, and find a 13-base region of homology (Formula: see text) present in multiple copies in the 5'-flanking region of each gene. An adjacent 15-base sequence is present only in glycerol-3-phosphate dehydrogenase and aP2 genes. Both of these elements share homology with putative viral enhancer core sequences. These results indicate that the aP2 gene contains sequence information necessary for differentiation-dependent expression in fat cells; common elements shared by adipocyte-specific genes may play a role in this process.