The P blood group system in pigeon breeders and pigeon breeder's disease.

A blood group P1-like antigen has been found in gram-negative bacilli isolated from pigeon droppings, in pigeon serum, and on pigeon red blood cells. As a probable resident of the environment of the pigeon loft, the antigen stimulated formation of anti-P1 antibody in eight of 11 pigeon breeders who belonged to the P2 blood group. Only one of 11 random hospitalized patients with the P2 blood phenotype had a detectable titer of anti-P1 antibody (P less than 0.01). The titer of anti-P1 antibody was not significantly different in symptomatic vs asymptomatic breeders. The presence or absence of anti-P1 antibody could not be correlated with any band of immunoprecipitates formed between pigeon breeder's serum and crude extract of pigeon droppings. The P antigen was identified in pigeon-dropping extracts of breeders with the P2 blood phenotype by inhibition of hemagglutination. We conclude that anti-P1 antibodies appear to be a component of the immunologic response to avian antigens of pigeon breeders but are probably unrelated to the pathogenesis of pigeon breeder's disease.

Acceleration of fetal lung maturation by aminophyllin in pregnant rabbits.

To test the hypothesis that fetal lung maturation can be accelerated by one of the xanthine derivatives, aminophyllin was given to 40 pregnant rabbits beginning on the 20th gestational day for a period of 7-10 days. The fetuses were delivered by cesarean section and fetal lung maturity was assessed by determining the biochemical, functional, and ultrastructural characteristics of aminophyllin-treated vs. control animals. The phospholipid content of the lung tissue homogenate from the aminophyllin-treated group was significantly higher than in the control subjects (saline injected) at 28 days of gestation (421 +/- 9 vs. 368 +/- 12 mug/mg wet wt, mean +/- SEM) and at 29 days of gestation (531 +/- 10 vs. 475 +/- 20). The alveolar wash phospholipid content of the aminophyllin-treated group was higher at 30 days (167 +/- 9 mug/mg dry wt, mean +/- SEM vs. 117 +/- 17). The lung compliance derived from pressure volume curves was also significantly higher in the aminophyllin-treated group when compared with controls at 27 days of gestation (0.023 +/- 0.0005 ml/cm H2O, mean +/- SEM vs 0.010 +/- 0.0002) and at 28 days of gestation (0.048 +/- 0.0003 vs 0.035 +/- 0.0006). There was no significant difference in the number of lamellar bodies in the type II cells between the aminophyllin-treated and the control groups. The data show that aminophyllin has accelerating effects on fetal lung maturation in rabbits when the drug is given to pregnant rabbits during the last 7-10 days of gestation.

The lamellar substructure of osmiophilic inclusion bodies present in rat type II alveolar pneumonocytes.

When rat pulmonary tissues are processed as outlined in this paper, the type II cell's surfactant containing osmiophilic inclusion bodies possess a periodic substructure. This substructure consists of electron-opaque lamellae, 26 A in thickness alternating with 16 A wide electron-translucent zones.

Early changes in lungs of rats exposed to 70 per cent O2.

Sixty-six respiratory disease-free rats, divided into four groups, were exposed to 70% O2 for 1.5, 4, 7, and 10 days and compared with 31 littermates exposed to room air for equal times. Lung surfactant was separated from macrophages and potential serum protein contamination by differential centrifugation of endobronchial washings. In the O2-exposed rats, developing lung edema was demonstrated by decreased dried/fresh lung weight ratio and increased alveolar protein content at 7 and 10 days. At 7 days, lung compliance slope and hysteresis loop area decreased, while critical opening pressure increased. Ultrastructurally, the only abnormality seen was an irregular widening of the alveolar capillary basement membrane on day 10. Alveolar lecithin content decreased slightly during the 10 days exposure, but remained highly saturated, whereas whole lung lecithin content increased. These results suggest that the initial mechanical and morphological alterations in rats exposed to 70% O2 are related to lung edema and are not dependent upon lung surfactant alterations.

Modern concepts about drowning.

Drowning remains one of the three leading causes of accidental death in the world, yet few textbooks deal with its evaluation and treatment. Because of overemphasis placed upon distinguishing between fresh- and sea-water drowning, the importance of immediate attention to simple and effective resuscitative procedures has been bypassed. We have outlined a continuum of evaluation and treatment in four stages: (1) emergency care at the scene and during transportation, (2) hospital admission resuscitation, (3) intensive care, and (4) return to normal. Four representative cases are presented in order to review pathophysiological concepts in this serious problem.

Thyroid hormone influence upon lung surfactant metabolism.

Thyroid administration and thyroidectomy in the rat profoundly affect the morphological characteristics of the type II pneumonocyte and the quantitative harvest of lung surfactant obtained from alveolar washings. The correlation of the ultrastructural changes with quantitative alterations in lung surfactant is evidence that the lamellar bodies within this cell are the source of the surface-active phospholipids utilized at the air-liquid interphase of lung alveoli. Our findings suggest that in the rat, L-thyroxine may be a potent regulator of lung surfactant metabolism.