The hypothesis tested in this study is that diabetes has a different impact on an artery in which endothelium-dependent responses derive from both nitric oxide (NO) and endothelium-derived hyperpolarizing factor (EDHF) compared with responses in which NO predominates and EDHF is absent. The streptozotocin-treated rat model of diabetes was used, and the arteries were mounted on a wire myograph. In mesenteric arteries depolarized and constricted with phenylephrine, acetylcholine evoked hyperpolarization (31 +/- 2 mV) and complete relaxation; these responses were attributed to EDHF and NO. In femoral arteries, acetylcholine evoked a small, NO-mediated hyperpolarization (5 +/- 1 mV) and incomplete relaxation. Bradykinin evoked NO-dependent responses in mesenteric arteries. Whereas diabetes significantly impaired the EDHF-dependent hyperpolarization and relaxation in mesenteric arteries, NO-dependent responses in femoral and mesenteric arteries were preserved. 1-Ethyl-2-benzimidazolinone evoked hyperpolarization and relaxation in mesenteric arteries, and this was impaired in diabetes. In conclusion, NO-dependent responses are preserved in diabetes, whereas endothelial responses-dependent upon EDHF appear to be impaired. The putative channels responsible for mediating the EDHF response may be altered in diabetes.

Aims/hypothesis. The impact of early vitamin E supplementation on vascular function in diabetes remains unresolved. Therefore, we examined the effects of vitamin E on functional and structural parameters and on chemical markers that are disturbed in diabetes in mesenteric and femoral arteries. Methods. Segments of both arteries, taken from control and 8-week-old streptozotocin diabetic Wistar rats that were treated or not with vitamin E, were mounted on wire and pressure myographs, after which endothelium-dependent and -independent vasodilation was assessed. Passive mechanical wall properties and the localisation and levels of protein kinase C (PKC)-β 2 and AGE were evaluated in these vessels. Results. Vitamin E supplementation was associated with improved endothelium-dependent and -independent vasodilatation in mesenteric arteries from diabetic rats. Impaired endothelium-dependent vasodilatation in diabetic mesenteric vessels was associated with PKC-β 2 up-regulation and this was prevented by vitamin E supplementation. Increased AGE accumulation and plasma isoprostane levels in diabetic rats were not changed by vitamin E. In the femoral artery, vitamin E supplementation had no effect on endothelium-dependent or -independent vasodilatation, but did prevent the wall stiffening associated with diabetes. Conclusions/interpretation. Early vitamin E supplementation has a beneficial effect on diabetes-induced endothelial dysfunction in resistance arteries. This benefit may arise from a direct effect on smooth muscle function, as a result of inhibition of the PKC-β 2 isoform by vitamin E. Abbreviations: ACh, acetylcholine · EDHF, endothelium-derived hyperpolarising factor · GHb, glycohaemoglobin · h, wall thickness · ID, internal diameter · L, length · l-NAME, N ω -nitro-L-arginine methyl ester · NO, nitric oxide · OD, outside diameter · P, intraluminal pressure · PKC, protein kinase C · PSS, physiological saline solution · SNP, sodium nitroprusside · STZ, streptozotocin · VitE, vitamin E supplementation · V max , maximal relaxation

Breast carcinoma is a rare cause of ectopic ACTH syndrome. There are only two previously reported cases in which ACTH secretion is documented. We describe the case of a 56-year-old woman who presented with clinical and biochemical features of ectopic ACTH syndrome in the setting of metastatic breast carcinoma. Despite aggressive management of her ectopic ACTH syndrome, her course was complicated by opportunistic infection, respiratory failure and death. Immunostaining of the breast metastases for ACTH was positive and in situ hybridization revealed proopiomelanocortin gene expression. This is the first reported case of ectopic ACTH syndrome associated with metastatic breast cancer in which the technique of in situ hybridization has been used to confirm the breast cancer metastases as the source of ectopic ACTH secretion.

Considerable concern has been expressed in both the lay press and educational circles that the Higher School Certificate (HSC) scores used for selection of students into university courses have a systematic bias in favour of ex-pupils of non-government schools and also in favour of males. At the same time, some faculties have been criticised for restricting the Year 12 subjects that can be included in the selection scores. It was found that students from government schools did not perform better at university than did their peers from independent schools with similar HSC results and female students performed no better and no worse than did males with comparable results. However students' performance was significantly influenced by the nature of the subjects in their selection score.

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