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In this study it is argued that the clinical manifestations of unstable angina pectoris, with at its extreme end impending myocardial infarction, may be due to increased coronary arterial vasomotion superimposed on a pre-existing obstruction in a coronary artery.As nifedipine, a powerful calcium antagonist, has initially proven its efficacy in relieving the symptoms of Prinzmetal's angina, a condition in which severe spasm of the coronary artery is now proven to be the main cause, the drug was given to two groups of patients in whom abnormal vasomotion was suspected and its effects scrutinized.Twelve patients with symptoms of coronary artery disease (CAD) were studied with repeated arteriograms after injection of 0.15 mg nifedipine in the left coronary artery. Two control cine-angiograms were made prior to drug administration and two cinefilms were repeated 30 s and 5 min after administration of nifedipine. The mean diameter of the normal, stenotic and poststenotic segments showed a statistically significant increase after drug administration. Vasodilalion persisted after coronary O2 saturation, and presumably coronary flow, had returned to normal.In 52 other patients, who were seen in the coronary care unit for impending myocardial infarction and who had been treated with maximal beta-adrenergic blockade, nitrates and bedrest, but who remained symptomatic, nifedipine 60 mg orally for 24 h was added to the treatment. Within 2 h after administration 42 of the 52 became asymptomatic. In the 10 non-responders, all with extensive multi-vessel disease, two sustained a myocardial infarction and eight received urgent coronary artery bypass grafting in an effort to alleviate their symptoms. All had severe 3 vessel disease in contrast to the responders in whom 1 or 2 vessel disease was predominant.These data show that increased coronary artery vasomotion can be influenced by nifedipine. The excellent clinical response to the drug in this group of patients with unstable angina pectoris indicates that nifedipine may become the preferred agent to be used particularly when the cause of the angina pectoris is suspected to be the result of abnormal coronary vasomotor tone. [ABSTRACT FROM PUBLISHER]

1. Grass output on 102.4 acres of young ley was measured in the 1946 season by (a) periodic clippings according to the Movable Cage Methods T and IT. and (b) periodic weighings of 120 bullocks from April 16th-April 24th, 119 bullocks from April 25th- May 29th, 132 bullocks from May 30th-July 20th, 88 bullocks from July 21st Augu8t 26th and 68 bullocks from August 27th-September l8th. 2. The three methods employed were compared by computing the nutrients supplied by the grass as measured by clippings with the nutrients computed to have been necessary for the maintenance and live-weight increase of the stock. 3. Total output by the two Movable Cage Methods employed differed from that based on animal weighings by 18.2 per cent in the case of Cage Method II and by 49.0 per cent in the Case of cage Method I. The coefficient of correlation between individual period yield figures as measured by animal and those measured by Cage Method II amounts 166 p. to 0.74, while the coefficient of correlation between period output figures by animal with that from Cage Method I also amounts to 0.74. 4. The evidence suggests that Cage Method I lias a very considerable error during periods when growth is rapid and where the length of the grazing period is prolonged. The formula for Cage Method II seeks to make allowance for the difference in yield of the grass permitted unimpeded growth in cages during the- grazing period and that subject to defoliation outfield. 5. Collecting together the data for the experimental periods in 1945 and 1946 the relative yield figures taking output by Animal Method as 100, are output by Cage Method II, 95 and by Cage Method I 128. 6. The apparent consumption figures of grass per animal per day as measured by Cage Method TI agree better with grass consumption data reported by other workers than do those computed by Cage Method. The coefficients of variability averaged 25 per cent for clips inside the caged areas, 30 per cent for the pre grazing cuts, and, omitting one anomalous reading, 48 per cent for cuttings on the outfield grazed areas. These figures have to be regarded as minimum estimates of error since the sampling sites were not chosen entirely at random. 8. Output per acre up to September 18th amounted to 3.20 cwt. of live-weight increase in 164 stock grazing days. For the entire season up to 1st November the total grass output by Cage Method II amounted to 28.2 cwt. of starch equivalent per acre, of which only 41 per cent was obtained by mid-June. By deliberate intent grazing was not as thorough as in 1945, about 4J cwt. of dry matter per acre being left uneaten at the end of each grazing period. 9. The data support the view that higher grassland productivity under the conditions obtaining in this experiment can be secured by long rest periods and lenient defoliation. 10. On the whole the results obtained up to date are in agreement with the idea that the Movable Cage Method provides a good measure of pasture output. 11. The investigation is being continued. [ABSTRACT FROM AUTHOR]

Describes the ions from the plasma with self-extracting properties. Charge/mass separation provided by static magnetic field; Displacement along the detector axis; Gold cathode detector with a fast phosphor.