Biomedical engineering support. Quarterly progress report, September 15, 1971--December 15, 1971

The power input to the air drive line, input to the air chamber, input to the pumping diaphragm and output from the Kwan-Gett artificial heart has been measured at different atrial pressures with a constant frequency of 120 beats per minute and constant mean arterial pressure of 100 mm Hg. These measurements were made in vitro. The various efficiencies, cardiac outputs and pressures corresponding to the power measurements were also determined. (auth

Biomedical engineering support. Quarterly progress report, June 15, 1971-- September 15, 1971

A daily power profile for the artificial heart has been determined from the literature and equipment and instrumentation has been assembled for measuring the efficienciea and power losses in the Kwan-Geff antificial heart. (auth

Faecal unconjugated bile acids in patients with colorectal cancer or polyps.

The unconjugated faecal bile acid profiles of 14 patients with colorectal cancer, nine patients with polyps and 10 controls were compared using gas liquid chromatography, controlling for such confounding variables as cholecystectomy, gall stones and hepatic function. Patients with adenomatous polyps had a higher concentration of faecal bile acids (5.23 mumol/g, 2.16-13.67 (median, range) v 1.96, 0.91-6.97; p = 0.016) lithocholic acid (2.41, 0.88-3.22 v 1.07, 0.38-2.03; p = 0.013) and total secondary bile acids (5.23, 2.16-13.4 v 1.96, 0.73-6.63; p = 0.02) compared with control subjects. Patients with colorectal cancer had an increased (p = 0.029) proportion of secondary faecal bile acids (mol%) compared with controls (100, 96.5-100 v 95.19, 81.73-100) and the ratios of the primary bile acids, cholic and chenodeoxycholic acid, to their respective derivatives (secondary bile acids) were significantly lower in cancer patients compared with control and patients with polyps (p = 0.034 to 0.004). This study lends further support to the theory that bile acids may play a role in the development of polyps and colorectal cancer