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Biomedical subjects

J Koudstaal

Publications and source records attributed to J Koudstaal.

At least 109 records · Page 6Linked to original sources
PubMed1975

The carbon dioxide laser; some possibilities in surgery.

The CO2 laser emits an infra red beam with a wavelength of 10,6 mu. Focussing this beam gives a tremendous energy density. The strong absorption of this wavelength allows tissue evaporation at the focal point of the beam. The first surgical application is the use of this laser as a light knife. Satisfying haemostasis can be obtained. Vessels with an internal diameter up to 0,5 mm being sealed, haemostatic cutting is possible. Even cortical bone can easily be cut with this instrument. The ability to vaporize tissues can be used for tumor destruction. Special attachments for endoscopic surgery are available. Experimental work in the rectum and on vocal cords has been done in our laboratory. The important problem in laser surgery is the necrosis on the edges. Investigations about the viability of the margins, showed that the width of the necrosis is in linear relationship with the rate of the exposure time. For an exposure of 1/10th of a second this width was about 130 mu, for an exposure of 6 seconds about 600 mu. After one year of experimental work with the CO2 laser we are convinced that this instrument might prove to be a reliable tool in surgery.

Animals↗
PubMed1975

Correlation between serum alkaline phosphatase and localization of alkaline phosphatase in the liver.

1. A good correlation exists between histochemically judged and biochemically determined activity of alkaline phosphatase in the liver. 2. Normal localization of alkaline phosphatase in the human differs from that in the rat. 3. In Wistar rats normal localization is: low or no activity in bile canaliculi preferently in the peripheral part of the lobule. 4. Normal localization in the human is: moderate to strong activity in the sinusoidal wall, in the central and peripheral part of the lobule. 5. A relation exists between histochemical localization and serum value of alkaline phosphatase in rat and in human. 6. Raised activities at localizations where "normally" no activity is present, e. g. bile canaliculi in human, sinusoidal wall in rat, do correlate the best with raised serum activities.

Alkaline Phosphatase↗