Intravenous streptokinase therapy for acute myocardial infarction in a community hospital: effect on ventricular function and mortality.

Streptokinase can dramatically impact upon management of myocardial infarctions in community hospitals. When given by experienced personnel during the first six hours after onset of symptoms, streptokinase is associated with a high patency rate, improved left ventricular function, and reduced mortality. Careful screening of patients results in a low complication rate with infrequent serious bleeding. Streptokinase should be utilized in those hospitals without cardiac catheterization facilities, but in light of the relatively high incidence of recurrent pain (15.8%), transfer of stable patients to a facility with a catheterization laboratory should be carried out within 24 to 72 hours. As approximately 60% of patients will require PTCA, CABG, or both, diagnostic cardiac catheterization should be considered in all patients unless there are other mitigating factors.

Accuracy and interobserver variability of coronary cineangiography: a comparison with postmortem evaluation.

The accuracy of interpretation of coronary cineangiography by two independent observers was tested against postmortem findings in 27 patients who died within 6 months of cardiac catheterization. Variations in cineangiographic interpretations between the angiographers were also evaluated. Two patients had normal coronary arteries, while the remaining 25 patients had significant coronary artery disease. Significant stenosis was defined as 75% or greater reduction in luminal diameter. Of 326 coronary segments that could be evaluated postmortem, 15% could not be evaluated cineangiographically. The respective overall accuracy of the two observers was 89 and 88% with an accuracy of 96 and 100% for the left main coronary artery, 91 and 93% for the left anterior descending artery, 84 and 86% for the right coronary artery and 89 and 79% for the left circumflex coronary artery. Cineangiographic assessment of luminal status distal to a significant proximal lesion was possible in more than 70% of major vessels with accuracy levels of 86% for both observers. Of 96 distal vessels inadequately opacified cineangiographically, 49 (52%) were found to be free of significant lesions. Both angiographers agreed in their assessment of 86% of the 340 coronary segments. Interobserver agreement was significantly better for the left main, right and left anterior descending coronary arteries than for the left circumflex coronary artery (p less than 0.05). Accuracy was 93% for 244 segments that were adequately opacified and assessed the same by both angiographers. Cineangiography can thus be used to evaluate coronary anatomy with a high degree of accuracy and minimal interobserver variability.

Mercury's Surface: Preliminary Description and Interpretation from Mariner 10 Pictures.

The surface morphology and optical properties of Mercury resemble those of the moon in remarkable detail and record a very similar sequence of events. Chemical and mineralogical similarity of the outer layers of Mercury and the moon is implied; Mercury is probably a differentiated planet with a large iron-rich core. Differentiation is inferred to have occurred very early. No evidence of atmospheric modification of landforms has been found. Large-scale scarps and ridges unlike lunar or martian features may reflect a unique period of planetary compression near the end of heavy bombardment by small planetesimals.

Mariner 10 pictures of mercury: first results.

Mercury has a heavily cratered surface cotntaining basins up to at least 1300 kilometers diameter flooded with mare-like material. Many features are closely similar to those on the moon, but significant structural differences exist. Major chemical differentiation before termination of accretion is implied.

Venus: atmospheric motion and structure from mariner 10 pictures.

The Mariner 10 television camieras imaged the planet Venus in the visible and near ultraviolet for a period of 8 days at resolutions ranging from 100 meters to 130 kilometers. Tle general pattern of the atmospheric circulation in the upper tropospheric/lower stratospheric region is displayed in the pictures. Atmospheric flow is symmetrical between north and south hemispheres. The equatorial motions are zonal (east-west) at approxiimnately 100 meters per second, consistent with the previously inferred 4-day retrograde rotation. Angular velocity increases with latitude. The subsolar region, and the region downwind from it, show evidence of large-scale convection that persists in spite of the main zonal motion. Dynamical interaction between the zonal motion and the relatively stationary region of convection is evidenced by bowlike waves.

Geologic setting of the apollo 14 samples.

The Apollo 14 lunar module landed in a region of the lunar highlands that is part of a widespread blanket of ejecta surrounding the mare Imbrium basin. Samples were collected from the regolith developed on a nearly level plain, a ridge 100 meters high, and a blocky ejecta deposit around a young crater. Large boulders in the vicinity of the landing site are coherent fragmental rocks as are some of the returned samples.

Lunar Orbiter Photographs: Some Fundamental Observations: Preliminary study reveals details of craters, crater distributions, and the major types of terrain.

High-resolution photographs returned by Orbiters II and III typically show a surface pitted with small, perfectly circular craters as much as 50 meters in diameter, some of which are strongly clustered; these are superposed on larger, generally shallower craters and must be a mixture of primary and secondary impact craters. Rough terrain is less heavily cratered but is crossed by numerous closely spaced troughs and ridges up to 3 meters high. Terraces, which commonly occur at the base of steep slopes, are also crossed by these troughs and ridges and have relatively few craters. Fresh craters-craters whose exterior slopes are covered with material different from that of the intercrater areas-are rare and are surrounded by angular blocks up to 80 meters in diameter, in varying numbers; these craters apparently undergo gradual destruction to shallow gentle depressions. The frequency of craters 100 meters and more in diameter varies widely, even on level terrain; some of the highest concentrations of craters occur on rays.