Changes in the incorporation of different RNA precursors into the maternal liver during pregnancy

Enduring maternal influences in a precocial rodent

The guinea pig is highly developed at birth and requires little active maternal care. Yet the mother and other social figures markedly influence biobehavioral processes of the offspring. Here, responses of guinea pigs and nonhuman primates to maternal and other social separation procedures are compared, and influences of social partners on endocrine responses and behavior in periadolescent guinea pigs are described.

Attachment and separation in young children

Attachment theory is criticized for being based on momentary stressful situations, for being limited to behaviors and occur with the primary attachment figure, for including only overt behaviors in its paradigm, and for failing to consider multiple attachments at different stages of life. A model of psychological attonement is then presented and supported by several studies documenting behavioral, physiological, and biochemical responses to separations from parents and peers.

Intrinsic and extrinsic factors affect infant responses to maternal separation

Responses of individuals to the loss of a primary attachment object may be quite variable. In humans, it has been suggested that only about 25% of bereavements result in substantial psychological or medical morbidity (Hamburg et al. 1975). In nonhuman primates, which are used to model responses to separation and loss, a similar estimate of about 25% has also been obtained (McKinney 1985). In addition, there are wide-ranging species differences in vulnerability with regard to the nature and severity of the response to maternal separation and/or loss. All of these findings suggest that there are important processes, intrinsic and/or extrinsic to the individual, that contribute to the probability that a loss will produce a major behavioral or physiological response. We have been systematically examining some of the factors that may account for a portion of this variability in two species of macaques (bonnet monkeys Macaca radiata; and pigtail monkeys, M. nemestrina).

Adrenal dopamine beta-hydroxylase induction in the young rat: influence of thyroid hormones

The adrenals of 14-day-old control and hypothyroid rats have been stimulated by insulin-induced hypoglycaemia, and the subsequent induction in dopamine beta-hydroxylase (DBH) has been studied. In control rats, DBH induction was maximum 48 h after insulin administration. Hypothyroidism completely suppressed DBH induction.

Incorporation of labeled ribonucleic acid precursors into maternal and fetal rat tissues during pregnancy

Tritium-labeled ribonucleic acid precursors, including cytidine, uridine, and orotic acid, were injected into rats with dated pregnancies (14 to 21 days) and virgin rats. The acid-insoluble counts indicating incorporation into fetal and placental tissues showed that the highest incorporation occurred with cytidine, particularly earlier in pregnancy. In contrast, uridine demonstrated a minor degree of incorporation but displayed facile and enhanced transplacental passage with duration of pregnancy as represented by acid-soluble counts. Orotic acid was minimally used by both fetal and placental tissues. The incorporation of labeled precursors into maternal liver, heart, and kidney demonstrated varying responses during the course of pregnancy.

Dexamethasone suppression and energy balance in eating disorders

The dexamethasone suppression test (DST) was investigated in 45 female anorectic out-patients (cross sectional study) nine of whom were followed serially as in-patients (longitudinal study). DST non-suppression was strongly associated with negative energy balance (low body weight and low Ponderal Index) but there was no significant association with the presence of affective or neurotic disturbance in these patients. These findings cast doubt on the value of the DST in the management of depressive illness.

Increased erythrocyte glutathione peroxidase activity in psoriatics consuming high-selenium drinking water at the Dead-Sea Psoriasis Treatment Center

Erythrocyte selenium-dependent glutathione peroxidase activity was measured in psoriatic Danes, before and after their four-week balneological therapy at the Ein-Bokek International Psoriasis Treatment Center, on the Dead-Sea shore in Israel. The drinking water in Ein-Bokek was found to be rich in selenium, a trace element with anticarcinogenic properties and of great importance in human nutrition and health. The most reliable biological parameter for increase in selenium bioavailability is the erythrocytes' glutathione-peroxidase activity. As psoriasis is a proliferative skin disease, the activity of this enzyme was assayed in 35 psoriatic Danes and in 25 long-term local hotel workers, as well as in 34 volunteers drinking low-selenium water. The glutathione peroxidase activity in the psoriatic patients increased significantly during their four-week stay in Ein-Bokek. Erythrocyte glutathione peroxidase activity in the hotel workers was 50% higher than that in the healthy volunteers consuming low-selenium water. A possible role of selenium in psoriasis is suggested.

Social separation increases alcohol consumption in rhesus monkeys

This study used 16 socially reared juvenile rhesus monkeys as subjects to test the hypothesis that social separation promotes alcohol consumption in this species. In the first part of the study, 12 monkeys were intermittently separated from their social groups, while 4 were separated before the beginning of the study and remained continuously separated. Refrigerated water or aspartame-sweetened water (vehicle) containing 6% alcohol (w/v) were presented after 4.5 h of fluid deprivation. Intermittently separated monkeys drank more alcohol during separation than when they were socially housed, and more than the continuously separated monkeys. Stable individual differences in consumption rate developed over repeated separations. These differences were not correlated with consumption of refrigerated water or vehicle, or with differential behavioral (locomotor) responses to social separation. This suggested that some monkeys were predisposed to drink more alcohol than others. The second part of the study determined whether established alcohol/vehicle consumption rates for all 16 monkeys were altered when the monkeys were not water deprived, and then when water and the vehicle were available at the same time as alcohol/vehicle. Among monkeys that drank the most (mean of 2.4 g/kg/h) and the least (mean of 0.8 g/kg/h), alcohol consumption was not affected. These results, combined with previous reports, suggest a neurobiological linkage between genetically based social attachment mechanisms, social stressors, and vulnerability to alcohol abuse and addiction in primates.

[A rheological method for the measurement of red cell deformability (author's transl)]

In a comparison of the filtration methods of Reid et al. and Schmid-Schönbein et al., the significance of other formed blood elements for the assessment of red cell deformability is established. The hydrodynamic measurements and the morphological inspection of the sieves show the interference of red cell pore passage by thrombozyte aggregates and white blood cells (which were not further identified). In light of these findings, which have since been corroborated by other groups, it is mandatory to remove all cellular blood elements exept the red cells in filtration test of the latter. Lowering the hematocrit improves the reliability of the test. The whole blood filtration test, popular because of its simplicity, cannot be standardized and yields results of questionable relevance.

Effect of ionic and non-ionic contrast media on red cell deformability in vitro

The effect on red cell deformability from solutions of the ionic contrast media diatrizoate, iocarmate and metrizoate and the non-ionic metrizamide and hypertonic saline (1.5 osm) was investigated by measuring the flow rate of 10% red cell suspension (VRBC) and of plasma (Vplasma) through Nucleopore sieves of 5 micrometer in diameter. By calculating the relative flow rate Vrel (VRBC/Vplasma) the deformability of the red cell was quantified. Both the contrast media solutions and the hypertonic saline solution decreased the Vrel, indicating an increased rigidity of the red cell. The increased rigidity was due mainly to the osmotic effect. The higher the osmolality, the more the deformability was reduced. The low osmotic metrizamide induced a smaller reduction in red cell deformability compared to ionic media of high osmolality in iodine-equivalent concentration.

Stress-induced depression model in female rats--biochemical and histochemical investigation of brain monoamines

Forced running stress induced a prolonged inactive state with the abolition of hormone-dependent cyclic behavior in some female rats which had already recovered from physical exhaustion. The state could be regarded as a "depression model" in these animals. In the biochemical study, norepinephrine in the hypothalamus was found to be significantly lowered in these animals. In the histochemical study, an increase of fluroescence intensity in nerve cell groups of the ascending norepinephrine system and a decrease of fluorescence intensity in nerve cells and terminals of the tubero-infundibular dopamine system were found in these animals. These findings were also seen in the rats which were examined immediately after the stress, but not in the rats which recovered their spontaneous and cyclic running activity in several weeks after the stress. These results suggest that changes of monoamine metabolism in the brain which is induced by the stress remains unrestored for a long time in the "depression model rats".

Properties of human erythrocyte hexokinase related to cell age

The kinetic, electrophoretic and immunological properties of hexokinase from human erythrocytes have been studied in relation to cell age. No differences in kinetic behaviour between hexokinase partly purified from reticulocytes, 10% youngest cells, normal red cell population or from 10% oldest cells were observed. The stability of the enzyme preparations showed little differences; hexokinase from the 10% youngest cells was the most labile enzyme, followed respectively by the enzyme from reticulocytes, normal red cell population and the 10% oldest cells. The electrophoretic pattern of erythrocyte hexokinase changed during senescence. The hexokinase activity located in the second band from the anode is shifted to the third with increasing cell age. The molecular specific acitivity of the enzyme from the 10% youngest cells, the normal red cell population and the 10% oldest cells remains the same, while the molecular specific activity of hexokinase from reticulocytes was much lower.

Intracellular distribution of ribonuclease activity during erythroid cell development

Five ribonuclease activities, separable by polyacrylamide gel electrophoresis, have been detected in erythroid bone marrow cells from anaemic rabbits. Their intracellular distribution has been investigated and compared with that of the ribonucleases in reticulocytes. Both the acid and alkaline ribonuclease activities of reticulocytes are much lower (30--50 fold) than those of bone marrow erythroid cells. The most marked decrease in enzyme activity occurs in the fractions containing ribosomes and mitochondria plus lysosomes. In these subcellular organelles there was also a qualitative change in the ribonuclease electrophoretic pattern, whereas the cytosol enzymes of marrow erythroid cells and reticulocytes remained largely unchanged. Several ribonucleases released from reticulocyte membranes with urea were similar to those present in the lysosomal plus mitochondrial fraction, as shown by detection of enzyme activity after polyacrylamide gel electrophoresis. The decline in ribonuclease activity was found to begin in the orthochromatic cells, which have a highly condensed nucleus and are no longer active in DNA and RNA synthesis, and to coincide with a decrease in acid phosphatase activity and loss of lysosomes.

A Spanish family with erythrocyte pyruvate kinase deficiency: contribution of various immunologic methods in the study of the mutant enzyme

Erythrocyte PK deficiency was detected in a 38-year-old man from Catalonia, in Spain. His father and his three children were proven to be heterozygous for the same mutant PK variant. This variant was characterized by low immunologic specific activity, normal (or slightly increased) stability to heat and to urea; normal isoelectric point, increased K0.5 for phosphoenolpyruvate, increased inhibition by ATP and normal activation by 0.35 mM fructose 1,6-diphosphate. The mutant PK variant was antigenically identical with wild enzyme as tested against anti wild erythrocyte PK serum by double immunodiffusion and micro complement fixation. The utility and the significance of the immunologic methods to be used in the study of mutant PK variants are discussed.

Globin synthesis in normal human bone marrow

Globin synthesis has been studied by in vitro labelling with radioactive amino acids in 60 normal human bone-marrow samples. Under the conditions routinely used to fractionate alpha and beta chains by chromatography alpha/beta production ratios ranging from 0.5 to 1.0 were obtained, depending on the method of sample treatment. This variation was due entirely to the presence of non-haem proteins derived from white cells which chromagraphy with globin on CM-cellulose. Purification of globin on Sephadex G100 and fractionation of alpha and beta globin chains by a modified chromatographic system resulted in alpha/beta ratios of unity. The relevance of these findings to the study of marrows in which there is unbalanced globin chain production is discussed.

Mechanisms of the acquired erythrocyte enzyme deficiencies in blood diseases

Acquired enzymatic activity defects of erythrocyte pyruvate kinase, glucose phosphate isomerase and phosphofructokinase have been studied in patients with acute myeloid leukemias, sideroblastic refractory anemias and unclassified acquired dyserythropoiesis. 6 patients with acute myeloid leukemia had a lowered erythrocyte pyruvate kinase activity; in 5 of them the concentration of the "pyruvate kinase"-antigen was parallely decreased, in such a manner that the ratio enzyme activity/immunologic reactivity (i.e. the molecular specific activity) was normal. In 1 patient with acute leukemia, 4 with refractory anemia and 1 with acquired dyserythropoiesis the defect of the pyruvate kinase activity was associated with a normal antigen concentration (and, therefore, the molecular specific activity in whole hemolysate was lowered). The enzyme activity was restored by incubation with SH reagents in two cases and by partial purification as often as it was performed. The electrofocusing pattern of erythrocyte pyruvate kinase was normal in both these types of defects. In two patients with so-called "acquired dyserythropoiesis" an erythrocyte glucose phosphate isomerase deficiency has been detected; in both the cases it was associated with a parallel decrease of the antigen concentration. The residual enzyme had a normal electrofocusing and electrophoretic pattern and a normal heat stability; the enzyme activity could not be restored by any treatment. In 1 patient with erythroleukemia and in 1 other with acquired dyserythropoiesis the erythrocyte phosphofructokinase activity was lowered. The enzyme activity was not restored by cross incubation in isologous plasma or by the SH reagents. In one case immunologic study could be performed, indicating that the enzyme defect was mainly due to the decreased ratio of the muscle type subunit of the erythrocyte phosphofructokinase. The electrofocusing pattern of deficient phosphofructokinases was normal. Finally, we point out the probable existence of several direct mechanisms, genetic and post translational, accounting for the acquired enzyme defects of red blood cells in various blood disorders.

Purification and characterization of human erythrocyte pyridoxine kinase

A 6000-fold purification of pyridoxine kinase from human erythrocytes has been achieved by a combination of DEAE-cellulose chromatography, ammonium sulfate fractionation, gel filtration and preparative disc polyacrylamide gel electrophoresis. Analytic disc polyacrylamide gel electrophoresis at pH 8.7 reveals two protein bands with similar mobility in the purified enzyme, but only one of these has catalytic activity. The enzyme is found to have a pI of 5.5 and a molecular weight of 65000 by gel filtration, and a broad pH optimum of 8.5. The enzyme is labile at acidic pH. The order of activation of divalent metal ions on the enzyme is Co-2+ greater than Mn-2+ greater than Mg-2+ greater than Zn-2+ greater than Cu-2+ greater than Ni-2+ greater than Fe-2+. Of the monovalent cations studied, K+ is the most effective activator, NH+4 is slightly less effective while Na+ is inhibitory. ATP is the specific phosphate donor for the enzyme. Sulfhydryl reagents did not significantly inhibit the enzyme. The Km for pyridoxine is 5.7 with 10-minus 6 M. Pyridoxal, pyridoxamine and 4-deoxypyridoxine inhibit pyridoxine kinase. Inhibition by pyridoxal is competitive and pyridoxal is observed to be phosphorylated effectively by the enzyme. Young human red cells have a higher activity of pyridoxine kinase than old red cells.

Cholesterol ester hydrolase in human red blood cells

1. Cholesterol ester hydrolytic activity (sterol-ester hydrolase EC 3.1.1.13) was detected in human red blood cells. Enzyme activity appeared confined to the cell membrane and was most marked in washed preparations of red cell ghosts. 2. Hydrolytic activity was stimulated by the anti-oxidants D-alpha-tocopherol and butylated hydroxytoluene. Marked inhibition was produced by erythrocyte hemolysate, sodium taurocholate, and Triton X-100. 3. Optimal pH for the reaction was 5.4--5.7. 4. Because red cell cholesterol is all unesterified, it is speculated that the hydrolase serves to maintain the erythrocyte membrane free of esterified cholesterol.

Four new pyruvate kinase (PK) variants and a classical PK deficiency

Four new red-cell pyruvate kinase (PK) variants are presented along with one case of so-called classical type PK deficiency. PK 'Tokyo II' had a low activity, Km (PEP) and Vmax, but a normal urea stability and only slight deviation from normal in neutralization tests by antiserum. It had a normal nucleotide specificity, abnormal electrophoretic mobility (fast moving) and the variant was associated with a mild hemolytic anaemia. PK 'Maebashi' had a low activity, high Km (PEP), low Vmax, urea instability, decreased reactivity to antiserum, normal electrophoretic mobility, normal nucleotide specificity and was associated with a moderate haemolytic anaemia. PK 'Tsukiji' had low activity, high Km (PEP), markedly high Vmax, urea instability, decreased reactivity to antiserum, abnormal electrophoretic mobility (fast moving) and grossly abnormal nucleotide specificity especially abnormal behaviour to ADP. The haemolytic process in this case was moderate to severe. PK 'Ube' was electrophoretically abnormal (fast moving) but otherwise had normal characteristics and the propositus was healthy and not anaemic. PK 'Ube' was found by electrophoretic screening for genetic PK polymorphism. In the classical type PK deficiency, the usual red-cell PK (PK-R1 and PK-R2) was not demonstrable by electrophoresis but instead M2-type PK was present, presumably by compensatory process. Kinetic studies confirmed that the patient's red-cell PK consisted of M2-type PK. This patient had a severe haemolytic anaemia.