Wall thickness of small pulmonary arteries. Its measurement in victims of sudden infant death syndrome.

We attempted to reproduce the work of Naeye with regard to the thickness of the muscular media in small pulmonary arteries among victims of the sudden infant death syndrome, using Naeye's methods. In two separate studies, using two slightly different groups of patients and different ocular grids, we observed a statistically significant difference between crib deaths and accidental deaths in hyperplasia of the arterial muscular media, the only parameter not dependent on point-counting. As no investigator has been able to achieve exactly the same results as Naeye in all three parameters, we concluded that point-counting is probably not the method of choice for this determination. Our data for hyperplasia (in the second phase of the study) correlated with those for the retention of periadrenal brown fat and hepatic erythropoiesis in the same patients.

The question of right ventricular hypertrophy in sudden infant death syndrome.

The relative weight of the free wall of the cardiac right ventricle was ascertained in 177 instances of the sudden infant death syndrome and 30 control infants who had died either in accidents (ten) or of fulminant illness (20). In contrast to the observations of Naeye et al in this regard, these victims of crib death did not exhibit right ventricular hypertrophy. Other evidence to support Naeye et al's contention that such infants are morphologically demonstrably different from normal is well documented. Hence, the significance of this discrepancy between our findings and theirs is unclear.

Extramedullary hematopoiesis in the liver in sudden infant death syndrome.

This study was undertaken to confirm or refute the findings of Naeye with regard to the pathologic continuation of extramedullary hematopoiesis in the livers of infants who die of the sudden infant death syndrome (SIDS). In general, our findings confirm his; however, although the data for SIDS do differ from those of controls, the differences are not statistically significant. Nevertheless, these results would seem to indicate the need for further investigation of the possibility of hypoxemia and/or anemia in affected infants.

Postmortem vitreous humor chemistry in sudden infant death syndrome and in other causes of death in childhood.

Postmortem vitreous humor concentrations reflect antemortem serum chemical values. The authors measured the postmortem vitreous humor concentrations of Na+, K+, Cl-, Ca+2, Mg+2, urea nitrogen, creatinine, and total protein of 127 children who died from sudden infant death syndrome (SIDS) and other causes. Forty-seven children, 1 hour to 13 years old, had died of medical or surgical causes; 21 children, 7 weeks to 11 years old, had died following acute trauma; 59 children, 8 days to 1 year old, had died of SIDS. There was no significant difference between mean postmortem vitreous humor concentrations of those who died of medical and surgical causes and those who died after acute trauma (non-SIDS). in both groups, the mean postmortem vitreous humor concentrations of Mg+2 and Ca+2 were significantly higher in premature infants. There was direct correlation of postmortem vitreous humor concentration and postmortem interval for K+, but the variation, +/- 26 hours, was too large to be of practical importance in estimating time of death in individual cases. The three patient groups were compared and the mean postmortem vitreous humor concentrations of all eight constituents in the SIDS and non-SIDS groups were in the same ranges. In SIDS, the mean postmortem vitreous humor concentrations of Mg+2, Cl-, and urea nitrogen were significantly different from values of the non-SIDS cases, but not enough to indicate SIDS or to be informative about the etiology of SIDS. Measurement of the concentrations of postmortem vitreous humor constituents may not aid in the diagnosis of SIDS, but may aid in discovering unsuspected antemortem serum chemical abnormalities.

Brown fat retention in sudden infant death syndrome.

This study was undertaken to confirm the findings of Naeye with regard to the pathological retention of the so-called brown fat cells in the periadrenal adipose tissue of infants who die of the sudden infant death syndrome. The percent of multilocular fat cells was determined in histological sections of periadrenal adipose tissue obtained from a series of 289 autopsies. In general, our morphological observations confirm his. However, our results indicate that the percent of periadrenal multilocular cells cannot be used as a diagnostic criterion in any single case. Futhermore, we consider that the mechanism for this delay in transformation remains unclear.