ABO incompatibility and reproductive failure. I. Prenatal selection

An analysis of previous spontaneous abortions and the frequencies of blood-group combinations in mother-child pairs was carried out in 500 gravidae. The rate of previous spontaneous abortions in blood-group-O women whose latest child has blood group B is significantly higher than in all other women. On the other hand, the combination mother B/child AB is rarer than expected, but no increase in the rate of previous spontaneous abortions is obvious among these women. These discrepancies are interpreted as an indication that prenatal selection associated with ABO incompatibility may operate at various stages from fertilization through pregnancy, and that different incompatible combinations may be subject to selection at different stages.     

Enzymatic and immunological studies of uroporphyrinogen decarboxylase in familial porphyria cutanea tarda and hepatoerythropoietic porphyria

Uroporphyrinogen decarboxylase activity was measured in hemoglobin-free lysates from two patients with hepatoerythropoietic porphyria (HEP) and from 12 unrelated patients with familial porphyria cutanea tarda (PCT). In HEP patients, enzyme activities were 5% of normal, and familial studies clearly confirmed that patients with HEP are cases of homozygous PCT. Immunoreactive uroporphyrinogen decarboxylase was measured by developing a direct and noncompetitive enzyme immunoassay (EIA). For the 12 familial PCT patients, we found an immunoreactive protein decreased (51%) to the same extent as the catalytic activity (48%) [cross-reactive immunological material ( CRIM ) negative]. The children from the HEP family were also CRIM negative, contrasting with another HEP family previously described as CRIM positive; our data support the hypothesis of a heterogeneity in familial uroporphyrinogen decarboxylase deficiency.     

Further studies on satellite nucleoli in rat and mouse hepatocytes

To provide more information on satellite nucleoli, these nuclear structures were studied by means of cytochemical and immunofluorescence procedures in rat and mouse hepatocytes without and following experimental inhibition of the RNA synthesis. The immuno-staining specific for nucleoli or B23 as well as C23 proteins demonstrated that satellite nucleoli and characteristic nucleoli exhibit the same fluorescence. The number of satellite nucleoli decreased after inhibition of nucleolar RNA synthesis in a similar way to the number of silver-stained granules (SSGs) of characteristic nucleoli. Inhibition of RNA synthesis also reduced the number of hepatocytes containing satellite nucleoli. Thus, satellite nucleoli seem to be real nucleoli from single NORs which did not fuse in the formation of a characteristic nucleolus.     

Increased placental concentrations of 25-hydroxyvitamin D3 and 24,25-dihydroxyvitamin D3 in pregnant rats treated with human chorionic gonadotropin

Pregnant rats were injected intrajugularly with 2500 i.u. human chorionic gonadotropin (HCG) toward the end of gestation (days 18-19) and 7.0 pmoles of tritiated 25-hydroxyvitamin D3 [( 3H]25(OH)D3) the following day. They were sacrificed ten to 24 hours later. [3H]25(OH)D3 and the in vivo produced [3H]24,25-dihydroxyvitamin D3 [( 3H]24,25(OH)2D3) in lipid extracts from maternal serum, kidneys, placenta and fetal tissues were separated by Sephadex LH-20 chromatography, and high performance liquid chromatography (HPLC). HCG treatment of pregnant rats increased significantly 25(OH)D3 levels in the placenta and kidneys and 24,25(OH)2D3 level in the placenta. Fetal metabolites levels were unaffected by HCG treatment. Serum and kidney levels of 25(OH)D3 and 24,25(OH)2D3 in pregnant rats were significantly lower than in non-pregnant rats. Serum and kidney levels of both metabolites in non-pregnant female rats treated with HCG did not differ from the untreated controls. HCG may, therefore, be involved in regulation of fetoplacental vitamin D metabolism.     

Chromatin proteins associated with micrococcal nuclease-sensitive and nuclease-resistant chromatin fractions of Kirkman-Robbins hepatoma and hamster liver

Micrococcal nuclease-sensitive (SP) and nuclease-resistant (PP) chromatin fractions from Kirkman-Robbins hepatoma and hamster liver were obtained. The molecular distribution of three non-histone proteins (NHCP1, NHCP2 and NHCP3), histones, and chromatin-bound protease activity between SP and PP fractions of both tissues was compared. Differences, mainly of quantitative nature, among non-histone proteins of neoplastic and normal tissue were observed. Moreover, it was found that polypeptides with mol. wt 81 000 (NHCP1), 39 000 (NHCP2) and 21 000, 35 000, 37 000 (NHCP1), 70 000, 112 000, 141 000, 157 000 (NHCP2), 30 000–33 000 (NHCP3) were associated only with the nuclease-sensitive part of chromatin of hepatoma and normal tissue, respectively. A major difference in histone compostion of hamster hepatoma and liver concerns histones H2A and H1. Furthermore, an enrichment of high mobility group proteins as well as other soluble non-histone proteins in an acid extract of the SP fraction was observed. Apparently chromatin-bound protease activity can be found in both fractions of chromatin.     

The effect of ethanol upon early development in mice and rats. VI. In vivo effect of acetaldehyde upon preimplantation stages in rats

In completion of the previously outlined "experimental alcohol blastopathy", the role of acetaldehyde in the induction of preimplantation pathological changes in rat embryos has been controlled. Two experimental models were used: the direct administration of acetaldehyde by gavage and the blockage of acetaldehyde metabolization by ANTALCOL (an aldehyde-dehydrogenase blocking compound). The main results were as follows: The exogenous acetaldehyde in the blood of pregnant animals has an obvious effect upon the developmental rate during the late preimplantation period (retarding segmentation, blastulation), and in one of the experimental models upon the oviductal-uterine migration rate. The increase of the blood acetaldehyde level by blockage of its further metabolization has a more marked effect as compared with the direct intravenous administration of the substance. According to our previous observations the intravenous application of ethanol on the same day (day 4) has no such effect. The direct noxious influence upon the developing preimplantation embryos (fragmentation) of the increased level of acetaldehyde obtained by ANTALCOL treatment is similar but more marked than this effect obtained previously by ethanol administration. The same effect observed after the direct administration of the substance is less marked than the effect of ANTALCOL treatment but more marked than the effect of intravenous ethanol administration. These results attest that acetaldehyde may contribute (alone or together with the effect of ethanol) to the induction of "experimental alcohol blastopathy". The less marked action of the substance proper introduced into the blood stream may be due--in our opinion--to its possible alteration during the period between distillation and application.     

cAMP and adenylate cyclase activity in Streptomyces granaticolor

Abstract Intracellular and extracellular cyclic adenosine 3',5'-monophosphate (cAMP) levels were determined during the growth of Streptomyces granaticolor . The intracellular level of cAMP represents not more than 10% of the total amount. cAMP synthesis varies in cultures growing on different carbon sources. The activity of adenylate cyclase in intact cells is strictly dependent on the presence of a metabolizable carbon source.     

Effects of mixed neutron-gamma irradiation in vivo on the cell surfaces of murine blood cells

Summary For studies on cell membranes, mice were exposed to mixed neutron + gamma reactor-radiation in the range of total doses from 0.5 to 4.5 Gy. Changes in functional activity of plasma membranes of erythrocytes, platelets, and lymphocytes were followed by a lectin-binding technique at various intervals afterwards. The amount of³H-concanavalin A bound to cells altered considerably during the 1st h after irradiation in all cell types. Lymphocytes and platelets, however, were more sensitive than erythrocytes as increased lectin-binding could already be observed after 0.5 Gy. The binding ability of these cells performed oscillatory behaviour. In addition, alterations in shapes and ultrastructure of cell surfaces and intracellular membranes were observed.