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Biomedical subjects

G Pearce

Publications and source records attributed to G Pearce.

62 records · Page 4Linked to original sources
PubMed1983

A rapid, large-scale method for purification of the metallo-carboxypeptidase inhibitor from potato tubers.

A rapid, large-scale procedure has been developed for the preparation of metallo-carboxypeptidase inhibitor (CPI) from potatoes. The inhibitor is extracted with 80% ethanol from partially cooked potato tubers. After the ethanol is removed and the salts are dialyzed away, the inhibitor is isolated in pure form by chromatography on sulfopropyl Sephadex. Ten pounds of potatoes yields 250 mg pure inhibitor, representing over 40% recovery. Commercial mashed potato flakes contain about 0.02% carboxypeptidase inhibitor and can be utilized as a starting material in the procedure described to yield over 70 mg inhibitor from a pound of flakes.

Hot Temperature↗
PubMed1983

Effects of feeding a carboxypeptidase inhibitor from potatoes to newly hatched chicks.

For the first time, the effects on animal growth and protein digestion of a specific inhibitor of the pancreatic digestive exopeptidases carboxypeptidases A and B were studied. Carboxypeptidase inhibitor from potato tubers was fed to newly hatched chicks at a level equal to that present in a diet containing 50% raw potato solids, which was severely growth depressing. At this level the effect of the carboxypeptidase inhibitor on growth was insignificant but the following effects were noted: (1) increased fecal protein (the increase mainly consisting of low-molecular weight proteins); (b) poorer feed efficiency; and (c) a significant decrease in pancreatic digestive proenzyme levels, although no hypertrophy was noted. In addition, the inhibitor was not digested readily in the intestinal tract and increased in concentration in intestinal contents as it progressed down the tract. Potato Inhibitor II, a potent trypsin inhibitor, when fed to chicks, also at the level found in the diet containing 50% raw potato, was severely growth depressing. The inhibitor produced significantly increased fecal protein and caused pronounced pancreatic hypertrophy. Thus, the growth depressing effects of raw potato tubers is probably due in part to the trypsin inhibitor, with only a small contribution originating from the carboxypeptidase inhibitor.

Animals↗
PubMed1981

A mercuric iodide detector unit implantable and externally powered for use in radionuclide tracer studies in small animals.

A small externally powered implantable gamma-radiation detector unit (35 X 12 mm diameter containing a mercuric iodide detector (HgI2), charge amplifier, radiotransmitter and an inductive power supply has been constructed. Since the total weight of the device is 5 g, it is suitable for implantation in laboratory animals such as rats or hamsters. A comparison between the implanted HgI2 detector unit and a conventional stationary 2 X 2 inch NaI(TI) detector has been performed by simultaneous measurements of the 133Xe clearance from a depot. Using 125I-iothalamate a kidney function study of an unrestrained hamster is shown as an example of measurements in the unrestrained animal.

Animals↗
PubMed1978

A radiotelemetry pill for the measurement of ionising radiation using a mercuric iodide detector.

A small radiation measuring pill is briefly described which utilises the principles of radiotelemetry and the properties of a room temperature semiconductor radiation detector such as mercuric iodide. By transmitting a radio signal to a remote receiver the pill could be an effective tool in localising bleeding sites along the gastrointestinal tract and also possibly in the diagnosis of gastrointestinal carcinoma. Other uses of the radiopill are suggested. The size of the pill is 27 mm x 10 mm diameter and consists of a mercuric iodide crystal, an amplifier, a frequency modulated transmitter and one battery. The radiotransmitter operates at about 106 MHz and has a range of about 10m, and the sensitivity of the pill has been found for 99Tcm, 131I and 32P.

Chlorides↗