Vascular regions supplied by the internal mammary artery as a graft demonstrate a significantly reduced endothelium-dependent flow reserve but a preserved endothelium-independent flow reserve as compared to vascular regions supplied by the native internal mammary artery. The selective decrease in endothelium-dependent flow reserve may be due to microvascular changes in the myocardial region supplied by the internal mammary artery after bypass grafting.

The morphological structure and immunohistochemical reactions of 100 pituitaries from cases of SIDS children (58 males and 42 females, average age 5.34 +/- 3.12 months) were studied. Controls consisted of 19 pituitaries from children (14 males and 5 females, average age 5.63 +/- 2.52 months) with a clearly identifiable cause of death e.g. drowing or strangulation. The microscopical and immunohistochemical studies for identifying pituitary cell types revealed normally developed organs. Unspecific necroses and haemorrhages were observed in 2 cases of SIDS but in none of the controls. Hyperaemia was detected in 51 (30 male/21 female) cases of SIDS. No significant differences were found in the distribution of microfollicles (54%), cysts of the intermediate zone (14%), persistency of the Rathke's pouch (44%), Erdheim's squamous epithelium (8%) or heterotopic salivary glands (3%). The semiquantitative immunohistochemical evaluations of the different cell types showed no significant variations from the control group. The pattern of distribution of the intracytoplasmic vacuolisations of the ACTH and gonadotropic cells showed no significant differences. Folliculo-stellate cells were either not demonstrable--commensurate with age--or showed a normal distribution. The results for both study groups may be defined as consequences of terminal agony, but failed to reveal the cause of the sudden infant death.

Adrenocorticotrophic hormone (ACTH)-secreting adenomas of patients with Cushing's disease (undifferentiated and well-differentiated ACTH-cell adenomas) were studied ultrastructurally and analysed morphometrically by a computer-supported quantitative image-analysing system. They were compared with identically prepared ACTH tumours (undifferentiated and well-differentiated ACTH-cell adenomas) of pituitaries from bilateral adrenalectomised patients with Nelson's syndrome. The aim of our study was to look for significant differences in ultrastructure and to evaluate these findings statistically regarding adenoma types and clinical syndromes. Clinical syndromes aside, more secretory granules and larger-sized prosecretory granules were measured in the well-differentiated ACTH-cell adenomas. The undifferentiated adenomas showed a greater content of nucleoli and prosecretory granules. Within the adenoma types, comparison of well-differentiated ACTH-cell adenomas showed that the clinical group of Cushing's disease contained larger areas of cytofilaments, whereas the clinical group of Nelson's syndrome had a larger tumour size and more lysosomes. Comparing the undifferentiated adenomas of both clinical groups the adenomas in Cushing's disease contained larger nuclei and more lysosomes, whereas the adenomas in Nelson's syndrome were larger in tumour size and contained larger prosecretory granules. Comparison of well-differentiated and undifferentiated adenomas in Cushing's disease showed more secretory granules and bigger prosecretory granules in well-differentiated adenomas whereas in undifferentiated adenomas the total area of the nuclei is larger, the nucleoli increase in number and size and the lysosomes are more frequent. Comparison of well-differentiated and undifferentiated adenomas in Nelson's syndrome demonstrated more lysosomes in well-differentiated adenomas and a larger total area of the nuclei in undifferentiated adenomas. The differences between the well-differentiated adenomas (mainly more secretory granules and larger prosecretory granules) and undifferentiated adenomas (mainly more and larger nuclei and nucleoli and more prosecretory granules) prove the clear separability between the adenoma types, not demonstrated in the literature up to now. The significant differences between adenomas in Cushing's disease (mainly more cytofilaments) and Nelson's syndrome (mainly more ribosomes and larger prosecretory granules) may be interpreted as different cell reactions due to the hypercortisolism present in Cushing's disease and lacking in Nelson's syndrome following adrenalectomy. Despite the fact that both clinical syndromes are based on the same adenoma types, indistinguishable by light microscopy, significant morphometrical findings in ultrastructure allow a clear discrimination of both clinical types.