A unique colour and polarization vision system in mantis shrimps

The apposition compound eyes of mantis shrimps (stomatopods) are divided into three sections, the dorsal and ventral hemispheres and the midband. Many ommatidia of both hemispheres, and all those in the midband, sample the same narrow band in space. The function of the morphologically distinct midband region is not clear, but new evidence suggests that it may be adapted in a unique manner for colour and polarization vision. A series of carotenoid colour filters screen the photopigment and potentially provide a tetrachromatic input for contrast-enhanced vision or true colour vision. The filters are blocks of coloured droplets (red, orange, yellow, purple, pink or blue) within the rhabdoms of two rows of midband ommatidia. The arrangement of tiered microvilli in two other midband rows suggests that they provide a unique form of polarization vision.     

Direct relationship between urinary prostaglandin E and sodium excretion in essential hypertensive patients

Summary Urinary prostaglandins (PGEs and PGFs), sodium and potassium were measured in 17 essentially hypertensive patients. Significant positive correlations were found between a) PGEs secreted in 24 h and sodium excreted in 24 h, b) the ratio PGEs/U_NaV before and PGEs/U_NaV after volume expansion and c) the ratio Na/K and urinary PGEs. It was suggested that renal PGEs, potent natriuretic and diuretic substances, play an important homeostatic role in the extracellular fluid regulation, and consequently in long-term control of the arterial blood pressure.     

Action of Corynebacterium parvum on the activity of glycosidases and proteases of peritoneal macrophages in the mice]

Glycosidase and peptidase of non-treated Mouse peritoneal macrophages were characterized. The enzymatic activities of Corynebacterium parvum stimulated Mouse macrophages were compared to those of macrophages obtained from non-treated animals. All the enzymatic activities, but beta-C-galactosidase, were higher in stimulated Mouse macrophages.