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Biomedical subjects

H J Wijnen

Publications and source records attributed to H J Wijnen.

8 recordsLinked to original sources

Colposcopic findings and intraepithelial neoplasia in diethylstilbestrol-exposed offspring. The Dutch experience.

Data from two regional diethylstilbestrol clinics for colposcopic evaluation of young women with a history of diethylstilbestrol exposure in utero are presented: A total of 224 subjects with a well-documented history were enrolled in this study. Structural anomalies of the cervix and vagina were found in 30%. Vaginal epithelial changes were colposcopically observed in 65%, including vaginal adenosis in 22%. The prevalence rate of abnormal cytologic findings in the study group was 9%. In half of these patients a low-grade intraepithelial neoplasia of the cervix and vagina was found. It was concluded that colposcopy in diethylstilbestrol-exposed offspring in inexperienced hands can result in many unnecessary biopsies. Therefore colposcopic examination should be performed by expert colposcopists in referral diethylstilbestrol centers.

Adult↗

Noradrenaline concentration and turnover in nuclei of the hyothalamus and the medulla oblongata at two stages in the development of renal hypertension in the rat.

The noradrenaline concentration and the alpha-methyl-para-tyrosine (alpha-MPT)-induced disappearance of noradrenaline were determined in several nuclei of the hypothalamus and the medulla oblongata of renal hypertensive rats (two-kidney Goldblatt hypertension). A decreased alpha-MPT-induced disappearance of noradrenaline was found in the nucleus interstitialis striae terminalis and the nucleus paraventricularis 3 days after renal artery constriction, when blood pressure was slightly, but significantly higher than that of sham operated rats. At this stage the alpha-MPT-induced disappearance of noradrenaline was enhanced in the nucleus commissuralis and the A1-region of hypertensive rats while the noradrenaline concentration in the A1-region was significantly elevated. No significant differences were found in both parameters in hypothalamic and medullary nuclei 3.5 weeks after the operation, when hypertension had fully developed. These findings are indicative of the occurrence of transient changes in the activity of noradrenergic neurons located in the medulla oblongata and projecting to the hypothalamus during the initiation of the development of two-kidney Goldblatt hypertension.

Animals↗

Adrenergic innervation of the rat hypothalamus.

The adrenergic innervation of the hypothalamus was studied by measuring hypothalamic adrenaline levels following surgical transection of the lower brain stem or electrolytic lesion of the medullary adrenaline-containing cell groups. The adrenaline levels in some hypothalamic nuclei and in the median eminence showed a slight decrease after partial transection of the medulla oblongata, whilst there was a pronounced decrease (by 59-78%) 7-10 days following total hemisection or unilateral lesion of the C1-catecholaminergic cell group in the medulla oblongata.

Animals↗