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The relationship between regional left ventricular (LV) motion and global pressure relaxation of the left ventricle remains unclear. To clarify the recent concept of segmental early relaxation in coro nary artery disease, the authors in vestigated two groups of patients. In group I, all 12 patients (mean age 47±7 years) exhibited evidence of a normal heart after an extensive in vestigation. In group II, 25 patients (55±7 years) presented an isolated stenosis of the left anterior descend ing coronary artery, and they under went a hemodynamic investigation before and after (six to nine months) a durable successful percutaneous transluminal coronary angioplasty (PTCA). After all conventional hemody namic measurements had been done, a quantitative frame-by-frame analy sis of left ventricular wall motion was conducted. The authors' method is derived from that of Ingels, applying to LV cineangiograms filmed in 30° right anterior oblique view at a 50 frames/second rate. Thus segmental wall motion is analyzed in terms of amplitudes (%), velocities of shorten ing and lengthening in circumfer ences/second (circ/sec), and times of events (%). Statistical results took into account the reproducibility of the method. Main results regarding the control state of group II consisted of an asy nergic motion of the anterior region taking place from end systole to early diastole: 1. Early end of contraction in an terior segments (% of systolic time in terval : 88±14% vs 96±6% in group I, p < 0.001) 2. Asynchronism at end systole (maximal velocity of shortening — 0.4±2.3 circ/sec in anterior segments vs 0.05±1.9 in inferior segments, p < 0.02) 3. An early but poor outward an terior wall motion (anterior lengthen ing at 0.04 sec after the end of ejec tion 2.9±10% in group II versus 5.4±7.2% in group I, p < 0.05) These abnormalities are strongly correlated with a significant impair ment of peak negative diastolic pres sure/diastolic time (dP/dt) (1500 ±400 mmHg. sec-1 vs 1850±410 in group I, p < 0.02). Long-term beneficial effects of PTCA in group II were characterized by an almost complete normalization, both asynergy and relaxation taking place back within the normal range. The authors conclude that in this kind of patient, peak negative dP/dt could be an index of an asynergic seg mental motion, this one being cor rectly analyzed and quantified on LV cineangiograms with our method.

The time course synthesis of the polypeptides of monkeypox virus (MPV) in cynomolgus monkey kidney cells was studied by one-dimensional SDS-polyacrylamide and by two-dimensional polyacrylamide electrophoresis. Cytosine arabinofuranoside (Ara-C) was used to differentiate early and late proteins. The synthesis of several early polypeptides was shown to continue throughout the time course. The synthesis of late polypeptides was shown to start at the peak of DNA synthesis (5–7 hr postinfection) and to continue throughout the remainder of the time course. Some individual polypeptide bands resolved by one-dimensional SDS-PAGE were shown to consist of multiple polypeptides using two-dimensional electrophoresis. These multiple polypeptide species, i.e., polypeptides of the same molecular weight but different isoelectric points, represented both structural and non-structural viral proteins. About 115 polypeptides are shown to exist in the purified virus by using two-dimensional electrophoresis.

The changes in the cardiac electric field during exercise have been studied by conventional vectorcardiographic techniques. Criteria have been developed to distinguish the changes seen in patients with coronary-artery disease proven angiographically from the changes in patients with normal coronary arteriograms. These criteria were derived from a learning set of 105 patients. Vectorcardiograms were taken immediately before and immediately after a maximal treadmill exercise test. In this group of 105 patients—72 with abnormal coronary arteries and 33 with normal coronary arteries—vectorcardiography before and after exercise diagnosed correctly 86% of the abnormals and 82% of the normals. This gives a sensitivity of 86% and a specificity of 82%. ST-segment analysis in the same group gave a sensitivity of 60% and a specificity of 85%. The same criteria applied blind to a second testing set of 92 patients gave a sensitivity of 84% and a specificity of 65%. In the same group ST-T analysis gave a sensitivity of 56% and a specificity of 78%. The sensitivity with these criteria compares favourably with the best results so far achieved with ST-segment analysis aided by computer. This technique can be easily used by the clinician and improves the diagnostic accuracy of exercise testing.

The authors studied the natural history of the electrocardiographic ST-segment using body surface mapping in 123 patients with acute inferior infarction who were not treated with thrombolytic agents. In 91 patients they compared body surface ST-segment maps recorded at 7.9 +/- 5.4 hours after the onset of acute myocardial infarction with maps recorded at 32.6 +/- 21.6 hours after infarction. In 46% of the patients the ST-segment distribution map pattern was unchanged. Twenty-eight percent of the patients moved to a ST-segment distribution associated with low mortality, and 7% correlated with a normal ST-segment distribution. Patients who started in a group dominated by marked anterior ST-segment depression or who developed this pattern at the time of the late map had a 45% morbidity, compared to 13% for patients who never developed this pattern (p less than 0.005). In a second group of 61 patients they compared maps recorded at 15.0 +/- 15.8 hours after infarction and repeat maps 19.6 +/- 13.0 recorded months later. At follow-up mapping, 44% of the patients correlated with a normal ST-segment distribution, 38% of patients had a low-risk pattern map and in 7% the map pattern was dominated by anterior ST-segment potential depression. The latter patients had a higher morbidity than patients in the other groups, but this did not reach statistical significance. Four of seven patients in this last group had significant angina at the time of follow-up mapping, compared to 2 of 54 patients in the other two groups (p less than 0.001).