Strokes in paroxysmal atrial fibrillation have more favorable outcome than in permanent atrial fibrillation.

OBJECTIVE: Our aim was to compare the course of IS due to ptAF and pxAF. METHODS: A prospective, single-center study was conducted in patients with AF and acute IS with 6-month follow-up. RESULTS: We included 178 patients: 70 (39%) with pxAF and 108 (61%) with ptAF. Compared with patients with ptAF, patients with pxAF more often presented with subcortical, mainly lacunar strokes (21% vs 8%, P = 0.01) and were less frequently dependent at discharge (16% vs 42%, P < 0.001) and after 6 months (16% vs 20%, P < 0.001). Strokes in patients with pxAF were more frequently categorized as non-cardioembolic (35% vs 18%, P = 0.01). In the multivariate analysis, after adjustment for confounding factors (diabetes, chronic heart failure, high risk of thromboembolism and lack of prestroke anticoagulation), ptAF was an important risk factor for unfavorable short-term (OR 5.4; P < 0.01) and long-term outcomes (OR 2.6, P = 0.01) of IS. In all patients with AF, the occurrence of non-cardioembolic stroke was related to a reduced risk of dependence or death in short-term outcome (OR 0.4, P = 0.04) and marginally influenced long-term outcome (OR 0.49, P = 0.09). CONCLUSIONS: The present study suggests that, compared with patients with ptAF, ISs in patients with pxAF have better outcomes.

Simulation of expert memory using EPAM IV.

EPAM is a theory of the processes of human perception and memory, first programmed for a computer by E. A. Feigenbaum in 1959, that has shown an excellent fit to experimental data from a wide variety of psychological tasks. Over the years, it has been progressively extended to new domains without essential change in its central mechanisms. This article examines EPAM IV, a version extended to account for expert memory, especially the work in recent years by Chase and Ericsson (1981, 1982) and Staszewski (1988a, 1988b, 1990). EPAM IV has also been adapted to deal with numerous other short-term and long-term memory tasks, which will be reported elsewhere. The main modifications of EPAM that are relevant to the serial recall task examined in this article are a schema in long-term memory (called a retrieval structure) created by the expert's learning and the addition of an associative search process in long-term memory. These new components operate in close interaction with the other EPAM structures to match the observed behavior. EPAM IV reproduces all of the phenomena explained previously by EPAM III and in addition gives an accurate detailed account of the performance (studied by Staszewski) of an expert recalling long sequences of digits. The theory substantially revises, improves, and extends Chase and Simon's earlier "chunking" explanation of expert memory.

The relationship between age and major league baseball performance: implications for development.

Lifetime performance data of 388 baseball players active in 1965 were analyzed to determine the age of peak performance for skills required to play baseball, to derive age-performance curves for athletic productivity, and to assess the magnitude of individual differences among elite and less able players. Cross-sectional and longitudinal analyses show that athletic performance on key indicators rises relatively quickly from age 19 to a peak age of 27 and then declines. The primary difference between elite and less able players is that performance of the elite players remains high for a longer period of time and decays more gradually. The performance of the most elite players is superior to that of less able players even at very early ages. These results parallel findings reported for other achievement domains and can be explained in terms of basic developmental processes involving the interaction of experience, physiological capacity, and motivation.

The epidemiology of prostatic cancer. Geographical distribution and time-trends.

Prostate cancer is one of the most frequent tumours in males. Globally about 235,000 new cases were estimated to occur in 1980. The cancer is particularly frequent in North America, where rates in blacks are often double those in whites, and in several European countries, being rare in much of Asia. After migration to the US, Chinese and Japanese show substantial increases. Incidence may be distorted by inclusion of varying numbers of so-called 'latent' cancers; for some comparisons mortality data are preferable. 'Small' latent cancers seem to be uniformly distributed irrespective of the incidence of the clinically manifest form. The incidence of prostate cancer seems to be increasing in most populations, particularly in Asia and Eastern Europe. In general, mortality follows suit. Birth cohort analysis shows that for US non-whites, cohorts born before 1896-1900 showed an increase in mortality for all age groups, but the death rates fell for cohorts born subsequently, a phenomenon also observed in Australia and England and Wales.

Cancer mortality in 1970-1972 among Polish-born migrants to England and Wales.

The 1970-72 cancer mortality of Polish migrants to England and Wales is compared with the cancer mortality prevailing in England and Wales and in Poland. Small numbers limit the analyses to the most frequent cancer sites only. The main findings are: (a) Compared with mortality rates in both their country of birth and of adoption, Polish migrants displayed intermediate values for cancers of the stomach, intestinal tract, and lung. For age-groups over 74 years, lung-cancer mortality among the migrants appears, however, to be higher than in both Poland and England and Wales. (b) A distinctly higher mortality among Polish migrants than either in Poland or England and Wales was apparent for lymphomas in both sexes, and for leukaemia and oesophageal cancer in males. (c) Female breast-cancer mortality among Polish migrants was much higher than in Poland, being close to the high mortality rates prevailing in England and Wales. The present findings are compared with the results of similar studies of Polish migrants to the United States and Australia and reasons for observed differences are advanced.

Evaluation of the action of some drugs on the blood supply of the myocardium in rabbits by means of the test of 125J absorption.

In experiments with rabbits, the influence of nitroglycerine, sorbonite and aminophylline on blood flow through the myocardium was compared by the radioisotope method. Adrenaline, noradrenaline and isoprenaline diminished capillary blood flow in the heart of rabbits. Persantine had no effect on capillary circulation in the heart of the experimental animals.