Clinical evaluation of porcine heterograft cardiac valves in 200 patients

Of 200 patients who received porcine heterograft cardiac valves, the first 100 did not receive postoperative anticoagulant therapy. In the second 100 patients anticoagulant measures were used when thrombogenic factors not related to the prosthesis were evident. Anticoagulation should be employed following mitral valve replacement while factors contributing to thromboembolism prevail. The conditions that tend to induce vascular stasis in the left atrium followed by embolism are chronic atrial fibrillation, a large dilated left atrium and a calcified left atrial wall. The results of our study provide assurance of the continued use of the porcine bioprosthesis.

Universal cardiac valve holder

A valve holder has been designed to facilitate the insertion of porcine cardiac valves. This holder allows a return to the operative technique established with the earlier generation of mechanical cardiac valves.

Deliberate hydrocarbon inhalation among low-socioeconomic adolescents not necessarily apprehended by the police

Nearly 600 low socioeconomic adolescents were given a 17-item multiple choice questionnaire designed by the authors. Demographic data tended, in some respects, to be consistent with previous research. In other respects there were some differences, e.g., sniffing tends to also be a problem with females. The data suggested that there are differences between chronic and social sniffers and that these differences should be taken into account when designing treatment/prevention programs. Another suggestion is that sniffing tends to be a social activity that is engaged in because (1) it is readily available and (2) it relieves boredom. Prevention programs have tended to focus on making it more difficult to obtain access to solvents, but this has had only limited success. The development of alternatives to neighborhood boredom should also be seen as an integral and important part of drug-abuse prevention.

Transport of 14C-diphenylhydantoin and 14C-leucine through rabbit crevicular epithelium

Isolated gingival crevices of rabbits were used to quantitate the transport of 14C-diphenylhydantoin and 14C-leucine through noninflamed crevicular epithelium. 14C uptake measured in the serum after two-hour application, indicated that both diphenylhydantoin and amino acid were transported and that at the dose levels used, more of the diphenylhydantoin was found in the blood than the amino acid. Very high levels of the drug were found in cerebral cortex while other tissues had much lower levels.

A preliminary report on the thymidine labeling indices and kinetics of cell proliferation in selected Morris hepatomas

The 1 hour thymidine labeling indices have been determined for 8 hepatomas which have growth rates which vary by a factor of 14. The indices for these tumors vary only by a factor of 4. Little correlation was found. Preliminary results have been obtained on the kinetics of cell proliferation of the rapidly growing Hepatoma H-35tc(2). The tumor transfer time is 0.7 months and the growth rate is 7.0 cm. per month. The calculated values for times in different phases of the cell cycle for H-35tc(2), assuming a log normal distribution for phase duration, were as follows: T(g1) (Gap I)-11.0 hours; T(s) (DNA synthetic period)-6.6 hours; T(g2) (Gap II)-4.2 hours; T(m) (mitotic time)-0.4 hours. Therefore, the total time, T(c), for one cell cycle was calculated to be 22.2 hours. The potential doubling time was calculated to be 43 hours. The GF (growth fraction) was estimated to be 53 per cent which would suggest that approximately one-half the total cell population is nonproliferating.

Mitral regurgitation occurring during methsergide (Sansert) therapy

The case history of a young woman who developed severe mitral regurgitation after four years of methysergide therapy is reported. Replacement of the mitral valve was required. A brief review of the toxic effects of methysergide is given and special reference is made to lesions of the heart valves that have occurred during methysergide therapy.