Pulmonary epithelial permeability in hyaline-membrane disease

Neonatal hyaline-membrane disease is complicated by pulmonary edema, yet left atrial pressures are normal. Alveolar-capillary-membrane permeability may therefore be increased. To assess pulmonary epithelial permeability, we measured the pulmonary clearance and half-life of aerosolized 99mTc-diethylenetriamine pentacetate (99mTc-DTPA) on 31 occasions in 15 intubated premature infants with hyaline-membrane disease. Three infants with respiratory failure due to other diseases were studied on four occasions. All studies of infants with hyaline-membrane disease that were performed in the first 72 hours of life demonstrated a biphasic clearance curve with a rapid-phase half-life of 1.6 +/- 0.6 minutes (mean +/- S.D.). As these infants recovered, the curve became monophasic with a half-life of 56.0 +/- 32.1 minutes. Two infants remained dependent on oxygen and ventilator support and had persistent biphasic curves with a rapid-phase half-life of 1.5 +/- 0.7 minutes. All infants without hyaline-membrane disease had monophasic curves with a half-life of 65.4 +/- 33.6 minutes. Using a similar technique, we observed that newborn lambs and piglets have a monophasic pulmonary clearance of 99mTc-DTPA (114 +/- 59 minutes in lambs and 52.5 +/- 16.3 minutes in piglets). We conclude that the lungs of neonates with hyaline-membrane disease are abnormally permeable to small solutes and that this abnormality persists in infants with subsequent chronic lung disease.     

Iatrogenic disease in the newborn

Summary The role of intrapartum asphyxia and cerebral birth trauma as an important cause of perinatal mortality is well known and its contribution to perinatal morbidity as a cause of cerebral palsy is widely appreciated. This has led to more careful monitoring of pregnancy and labour, although monitoring techniques are not without hazard. The widespread availability of intensive care facilities for the newborn has resulted in the survival of many infants, particularly those of low birth weight, who might previously have died. Efficacious modes of treatment may, unfortunately, bring in their wake serious problems in the form of iatrogenic disease which may cause or contribute to rapid demise or whose effects may not be fully apparent for many years. Ante natal investigations have also become frequently used and have their own hazards.     

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.     

Sequential changes in serum immunoglobulin levels in young RFM mice with host-versus-graft disease.

RFM mice perinatally inoculated with (T6 X RFM)F1 spleen cells develop raidply progressive host-versus-graft (HVG) disease. They are usually dead by 30 days with hyperimmunoglobulinaemia, immune complexes, plasmacytosis and marked T-cell deficiency. In the present studies, sequential quantitative analyses of serum immunoglobulins (Igs) were done, and search was made for high titred antibodies presumed to be major components of the excessive Ig levels. Based on the Ig changes, three stages of disease could be identified. In the first period, which extended from 7 to 10 days, the early appearance of IgA and IgM correlated with previous discoveries of the precocious appearance of germinal centres and enhanced antibody response. The second period, from 10 to 25 days, was characterized by rapid increases in all serum Ig levels in patterns which suggested a variable and selective loss of control of production of the individual Ig classes. IgG1 levels at 25 days averaged twenty-three times the highest adult control value. Failure of IgG2 and IgA levels to surpass adult maxima seemed only to reflect hastened maturation. Lack of success in finding high titred specific antibodies coupled with the previous evidence of poor primary antibody responses suggested the alternative possibility that most of the Igs were non-specific. The third stage, from 25 days to death, saw the apparent decline in IgG1 and IgG2 levels, and the progressive increase in the percentage of HVG mice with IgM levels above the adult maximum. It is proposed that the apparent divergence between Ig and antibody forming capacity is related to the severe disruption of the T-cell system induced by the HVG reaction.     

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.     

Morpho-functional changes of surfactant system in pulmonary tuberculosis

A complex study of different cellular and extracellular surfactant elements in the dynamics of the spontaneous course of generalized tuberculosis was made in 240 guinea-pigs and 77 patients with different forms of active pulmonary tuberculosis by using electron microscopy, biochemistry, and physical chemistry. A diagnostic scheme was proposed for life-time assessment of surfactant in bronchoalveolar lavage specimens. Three degrees of changes in surfactant were identified; 1) adaptive rearrangement of its elements developing in local surfactant damages; 2) significantly impaired type 2 alveolocyte production of surfactant, which affects its biochemical composition and capacity of forming characteristic structures; 3) common morphological, biochemical, surface-active signs of surfactant decompensation, profound metabolic disturbances, alveolar epithelial destruction with cleared alveolocytes found in the lavage.     

Metabolic changes in the lymphocytes of newborn rats in asphyxia

Hydrocortisone and cocarboxylase injected into newborn rats increased their chances of survival after asphyxia. Asphyxia was accompanied by increased succinate and dihydroorotate dehydrogenase activity in the lymphocytes, by lymphocytosis, and by an increase in the number of monocytes with hyperbasophilia of their cytoplasm in the blood and tissues. Hydrocortisone and cocarboxylase had a normalizing effect on these changes.Institute of Pediatrics, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. P. Avtsyn.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 78, No. 12, pp. 21–23, December, 1974.