No abstract

The spectral transmissions of cornea, aqueous humour, lens and vitreous humour of human eyes were measured in the range from 250 nm to 800 nm in 1 nm steps using a high resolution double monochromator. Cornea and lens are good cut off filters; 1% transmission was measured in various cornea samples between 291 and 298 nm, and in different lenses between 389 and 414 nm. Aqueous humour and vitreous humour showed high transparency (80%) at lambda > 320 nm. The wavelength range of keratitis effective irradiance was found to be completely within the wavelength range of absorption of the cornea, that of cataract effective irradiance was found to be at the short wavelength end partly outside the wavelength range of absorption of the lens. It may therefore be supposed that the action spectrum of cataract obtained by animal experiments is applicable to the human eye only with certain reservations.

To check the stimulatory potency of the tetrahydro forms of the two major pteridines o~urring in human tissues, neoptcrin and biopterin, NO synthase was purified 6000-fold from human cerebellum. Tetrahydrobiopterin stimulated the activity up to 4.5-fold in a concentration dependent manner with a maximum above 1/tM, whereas tetrah~,droneopterin was completely inactive in concentrations up to 100/.tM. Tetrahydrobiopterin, bat not neopterin derivatives, were copurified with the NO synthase activity. Our results demonstrate that human cerebellum contains a tetrnhydrobiopterin dependent NO synthaae activity.

Coronary artery anomalies, especially variations in the level of origin, are frequent. In most cases, the origin lies just a few millimeters superior to the supravalvular ridge; ectopic origins of more than one centimeter above this border are rare. We report a case in which the right coronary artery arises from the ascending aorta 38 mm above the supravalvular ridge.