Survival of the fittest?--survival of stored red blood cells after transfusion.

During the last 90 years many developments have taken place in the world of blood transfusion. Several anticoagulants and storage solutions have been developed. Also the blood processing has undergone many changes. At the moment, in The Netherlands, red blood cell (RBC) concentrates (prepared from a whole blood donation and leukocyte-depleted by filtration) are stored for a maximum of 35 days at 4 degrees C in saline adenine glucose mannitol (SAGM). Most relevant studies show that approximately 20% of the RBCs is lost in the first 24 hr after transfusion. Even more remarkable is that the average life span is 94 days after a storage period of 42-49 days. Such observations create the need for a parameter to measure the biological age of RBCs as a possible predictor of the fate of RBCs after transfusion. The binding of IgG to RBCs can lead to recognition and subsequent phagocytosis by macrophages. This occurs during the final stages of the RBC life span in vivo. We determined the quantity of cell-bound IgG during storage, and found considerable variation between RBCs, but no significant storage-related change in the quantity of cell-bound IgG. The significance of this finding for predicting the survival of transfused RBCs in vivo remains to be established. Hereto we developed a flow cytometric determination with a sensitivity of 0.1% for the measurement of survival in vivo based on antigenic differences. This technique has various advantages compared with the 'classical' 51Cr survival method.

Human corticotropin-releasing hormone during pregnancy.

Elevated irCRH levels up to 14 ng/ml were measured in 176 females in the last trimester. The highest maternal CRH levels were found in those females in whom the period from the onset of labour to full dilatation of the cervix and the time span of delivery were shortest. irCRH in amniotic fluid (120 +/- 180 pg/ml; n = 14) was in the same range as in umbilical cord plasma (233 +/- 188 pg/ml; n = 66) and 20-fold lower than in prepartal maternal plasma (5.38 +/- 4.49 ng/ml; n = 66). irCRH in maternal plasma correlated highly to irCRH in umbilical cord plasma (p less than 0.001; n = 66). After delivery irCRH disappeared from maternal plasma with a half-life of 50 minutes (n = 14). One day postpartum irCRH levels (n = 22) were undetectable. The height of the irCRH levels in the various biological fluids did not correlate to the mode or the pathological events of delivery (n = 43). Maternal ACTH levels above the normal range were encountered only in women immediately prepartal and did not correlate to the CRH levels (253 +/- 229 pg/ml; n = 66). Cortisol levels were higher in maternal plasma than in umbilical cord plasma due to elevated CBG (n = 78). Free cortisol levels were higher in the 3rd trimester than in the 1st (2.18 +/- 0.16 vs 1.16 +/- 0.73 ng/ml; n = 42). irCRH in maternal and umbilical cord plasma correlated to the hPl and estriol levels (p less than 0.001 and p less than 0.05; n = 66). We conclude that irCRH is secreted by the placenta into both maternal and fetal circulation. Though placental CRH is undistinguishable from hypothalamic CRH, the biological significance of placental CRH remains open. Our data show that placental CRH might be responsible for the changed function of the adrenal gland during pregnancy, with higher free cortisol levels in the last trimester. The extremely elevated ACTH levels during labour and delivery indicate that CRH is not the only mediator of stress-induced ACTH secretion in the regulation of the maternal hypothalamo-pituitary-adrenal axis.

[Passive smoking at the workplace--injurious to health? (author's transl)]. / Das Passivrauchen am Arbeitsplatz--eine Gesundheitsschädigung?

The question as to whether passive smoking at the workplace is injurious to health is dealt with. With the aid of the bibliographic standard literature on industrial, social and preventive medicine, all experimental investigations of this subject and published since 1970 were considered. The important results and findings are presented in tabulated surveys broken down by the substances contained in smoke. The present results of investigation are discussed with respect to a practical workplace model whose air-hygienic conditions are determined by legal prescriptions for workplaces. The measured concentrations of the particulate mass and of the most important individual constituents of smoke, carbon monoxide, nicotine and aldehyde make it highly unlikely that passive smoking at the workplace causes injury to health if the prevailing regulations governing the workplace are complied with. Particular attention has to be given to the occupational problems existing in night bars, restaurants and discothecs.

[Hyperkinetic portal hypertension. Arterioportal fistula: problems--case reports--review of the literature]. / Die hyperkinetische portale Hypertension Die arterio-portale Fistel: Problematik--Kasuistik--Literaturübersicht.

Hyperkinetic portal hypertension is caused by pathological arterioportal shunts. Clinical differentiation is necessary between extrahepatic fistulas, splenoportal hypertension (arteriovenous anastomoses at the level of the pre-penicilary arteries) and intrahepatic fistulas in "active" cirrhosis and malignant tumors. This paper reports the clinical and angiographic features of eight patients with this type of fistula. A review of the literature is also presented (144 cases). Because of the severity of this disease, surgical intervention is necessary. The surgical technique depends on the organ-related necessity of vascular preservation.