Mitochondrial lamellated bodies and surfactant depots in the Type II cells of the lung compared by bimetallic staining and X-ray analysis.

After heavy dosages of sensory irritants osmiophilic whorls (mitochondrial lamellated bodies) are found in the mitochondria of the Type II cells of the lung. To obtain evidence of their nature, the lead/osmium (Pb/Os) ratio in these and other bodies after bimetallic staining was studied by electron probe X-ray analysis during transmission electron microscopy. To allow for inter-specimen variation the Pb/Os ratio was divided by the Pb/Os ratio for chromatin in the same cell, to give a "relative ratio".

Maturity of fetal lungs tested by production of stable microbubbles in amniotic fluid.

Lung surfactant in amniotic fluid, and hence the maturity of the fetal lungs, can be assessed by observation of stable microbubbles (less than 15 micron diameter). Bubbles are formed by agitation with a Pasteur pipette and examined in hanging drops under the 10 x power of a microscope. Either after a count of bubbles, or after a general survey of hanging drops, the fluid is given a stable microbubble rating.

Postmortem changes in the surpellic activity of lung surfactant.

The surpellic activity of lung surfactant in mouse lungs stored in the cadaver persists for times much longer than those after which gross morphological changes at electron microscope level have been recorded.