Comparison of primary plexogenic arteriopathy in adults and children. A morphometric study in 40 patients

Pulmonary vascular changes were studied in histological sections from 15 children and 25 adults with primary plexogenic arteriopathy. The severity of medial hypertrophy and degree of vasoconstriction were measured in histological sections and there was a close correlation between these two variables in both children and adults. More advanced arterial changes, expressed as an index of pulmonary vascular disease, were more common in adults, and their severity correlated positively with the degree of medial hypertrophy. No such correlation was found in children. There were similar numbers of plexiform lesions per square centimetre in children and adults, so that the differences in the indices of pulmonary vascular disease were mainly due to the intimal changes. Concentric laminar intimal fibrosis was more severe in adults. It is suggested that intensive spastic vasoconstriction results in the development of fibrinoid necrosis and subsequently of plexiform lesions and that this may happen irrespective of the presence of severe intimal fibrosis. This suggests that children with primary plexogenic arteriopathy in whom plexiform lesions have not yet developed are more likely to respond to vasodilator treatment than are adults in whom irreversible changes associated with intimal fibrosis have developed.     

Comparison of HeLa 229 and McCoy cell cultures for detection of Chlamydia trachomatis in clinical specimens.

Consecutive clinical specimens of Chlamydia trachomatis (1,048) were inoculated in parallel on DEAE-dextran- and cycloheximide-treated HeLa 229 cells and cycloheximide-treated McCoy cells. HeLa 229 cell culture detected 113 positive specimens, and McCoy cell culture detected 103 positive specimens. This difference is not significant. However, HeLa 229 cell culture yielded significantly more inclusions than McCoy cell culture in the 95 specimens positive in both cell types (P = 0.042). For routine diagnostic purposes, a choice for one of the cell types may be determined by local preferences.     

Pulmonary venous changes in chronic hypoxia

Summary Lung tissue from 14 normal residents of high altitude regions, 10 patients with chronic bronchitis and emphysema, and 1 patient with Pickwickian syndrome was studied with regard to the occurrence of pulmonary vascular changes. In addition to the well-known pulmonary arterial alterations, lesions in small pulmonary veins were found in the great majority of the cases. These changes, consisting of medial hypertrophy and arterialization and of bundles of smooth muscle cells within the venous intima, have not been described before in man. These findings suggest that alveolar hypoxia acts not only on small pulmonary arteries and arterioles but also on veins of small caliber, probably by inducing venoconstriction.     

Epidemiology of mumps in the Netherlands.

In a Dutch population group neutralizing antibodies against mumps virus were determined by a plaque reduction technique, which proved reproducible, sensitive and specific. The results with sera of about 800 suburban children show that mumps is acquired at an early age with peak acquisition rates between the ages of four and six years. Over 90% have acquired mumps before the age of 14 years. More than 95% of about 1000 adults (18--65 years) have neutralizing antibodies. The relatively constant median titre suggests that antibodies persist during life. During a family study 77 clinical and 18 subclinical cases were observed. In families with index cases the attack rate was 26/37 = 0.71. Eleven children (excluding six babies) escaped infection. The mean attack rate during the epidemic was 0.30. The mean titre of mumps neutralizing antibody is maximal during the first year after the disease but declines during childhood. Mothers exposed to mumps in the family occasionally showed a significant rise in titre. Some seronegative mothers remained seronegative after exposure.