Cord blood plasma lipoproteins inhibit mitogen-stimulated lymphocyte proliferation

Lipoproteins were isolated from adult plasma and the umbilical cord blood plasma of newborn infants and were compared for their capacity to inhibit mitogen-stimulated [3H]thymidine uptake of adult peripheral blood mononuclear cells in vitro. Relative to the comparable adult lipoproteins, cord blood low density lipoproteins and high density lipoproteins inhibited mitogen stimulation at twofold to fourfold lower total protein concentrations. Apoproteins AI, B, and E were quantitated by radioimmunoassay of each of the adult and cord blood lipoprotein fractions. A strong correlation was observed between inhibitory activity and the amount of apoprotein E in the cord blood low and high density lipoproteins. Further evidence that lipoproteins containing apoprotein E accounted for the difference in suppressive activity of cord blood low and high density lipoproteins relative to the adult lipoproteins was obtained by selective removal of the apoprotein E-containing lipoproteins by using immunoaffinity chromatography or heparin-agarose adsorption. The results indicated that cord blood lipoproteins containing apoprotein E in association with apoproteins AI or B are capable of suppressing lymphocyte proliferation in vitro.     

Dietary influences on serum lipids and lipoproteins

Substantial data are available to indicate that the diet influences serum levels of cholesterol and lipoproteins. These data are derived from studies in laboratory animals, from epidemiologic studies, and from human investigations. Most research has focused on effects of diet on serum total cholesterol concentrations. In recent years, however, attention has shifted to individual lipoproteins, i.e., low density lipoproteins (LDL), high density lipoproteins (HDL), and very low density lipoproteins (VLDL). Three nutritional factors have been identified that raise serum LDL levels; these are saturated fatty acids, cholesterol itself, and excess caloric intake leading to obesity. The major cholesterol-raising saturated fatty acid in the diet is palmitic acid. Several nutrients can be substituted for saturated fatty acids to produce a reduction in LDL-cholesterol levels. These are polyunsaturated fatty acids, monounsaturated fatty acids, carbohydrates, and even one saturated fatty acid, stearic acid. The latter appears to be converted rapidly into a monounsaturated fatty acid in the body. Any of these nutrients can be used for replacement of cholesterol-raising saturated fatty acids in the diet. However, their relative effects on other metabolic processes remain to be determined fully. At present it appears that carbohydrates and monounsaturated fatty acids represent the preferred replacements for saturated fatty acids, although modest increases in polyunsaturated fatty acids and stearic acid, at the expense of cholesterol-raising saturates, probably are safe and may provide for greater variety in the diet.     

Variability of crystals of blood lipoproteins

The present paper studies lipoprotein of human blood plasma in the norm and pathology. The three informational groups of lipoprotein crystals are isolated, which correspond to certain types of diseases. The question of possible diagnostics of some diseases by means of the lipoprotein crystals type in the polarized light is under discussion.     

Cord blood transplantation in adult patients

Early clinical reports outlining outcomes for primarily pediatric patients undergoing UCB transplantation point to delayed time to hematopoietic recovery and favorable incidence and severity of GvHD. Recently, clinical reports in adult patients identified the feasibility of UCB transplantation for those patients lacking an available histocompatible-related or unrelated adult donor Intensive clinical and laboratory research is ongoing focused on strategies to foster UCB allogeneic donor engraftment thereby allowing wider application of this stem cell source for patients requiring allogeneic transplantation.     

The relative importance of prenatal and postnatal maternal influences on growth in mice

Summary The cross-nursing technique was used to assess the relative importance of prenatal and postnatal maternal influences on growth in mice from an unselected population originated from a cross of four highly inbred strains. Body weights were studied at birth, 7-, 14-, 21- and 42-days, in addition to the weight gains between these ages and tail length at 21 and 42 days of age. At littering, each dam in each nursing set retained two of her own offspring and two were transfereed to each of the other dams in the set, so that each nursed litter contained six young representing three mothers. Prenatal influences accounted for 37, 15, 10, 11 and 13 % of the total variation in the respective body weights, while postnatal influences accounted for 0, 64, 65, 49 and 14% at the respective ages. In the case of weight gains, prenatal influences were responsible for 16, 4, 6 and 30%, while postnatal influences were responsible for 66, 66, 31 and 7% of the total variation in gain during the respective four periods examined. Apparently the individual weight gain from 7 to 14 days was a better measure of the lactational performance of the dam than individual 14-day weight. For tail length, prenatal influences accounted for 6 % and 4 % of the total variation in tail length at 21 and 42 days, respectively, while postnatal influences accounted for 60 % and 24 % at the respective ages. Generally, there was no indication of an important interaction between the nurse and the nursed young at any stage studied.     

Psychosocial and reproductive influences on plasma lipids, lipoproteins, and atherosclerosis in nonhuman primates

Until recently, research in experimental atherosclerosis focused primarily on nutritional influences on plasma lipids, lipoproteins, and atherosclerosis. We review here the results of recent studies of independent and interactive influences of psychosocial and reproductive influences on atherosclerosis in nonhuman primates. These studies have produced evidence that, as in human beings, individuals with certain personality characteristics who are frequently faced with stressful or challenging situations are at increased risk of coronary artery disease. Preliminary evidence suggests that this relationship may be mediated, in part, by heightened sympathetic arousal, i.e., cardiovascular hyperresponsiveness, to the environmental challenge. Also, as in human beings, evidence has been produced that certain negative behavioral and psychosocial variables can have a significant independent influence on plasma lipids. As regards reproductive influences, the cynomolgus macaque seems to share with premenopausal white women a relative protection against coronary artery atherosclerosis. This "female protection" against diet-induced atherosclerosis is abolished by ovariectomy, which also results in increased total plasma and low density lipoprotein (LDL) cholesterol concentrations. Subordinate social status also seems to abolish female protection in some individuals. Preliminary evidence suggests that subordinate females most liable to this loss of protection are those with apparent stress-induced chronic ovarian endocrine dysfunction, which, in turn, is associated with increased plasma LDL cholesterol and decreased plasma high density lipoprotein (HDL) cholesterol concentrations.     

Preformed PAF-acether and lyso PAF-acether are bound to blood lipoproteins

PAF-acether (PAF) is a newly formed mediator not normally present in circulating blood. A compound exhibiting all of its biological characteristics but coeluting with phosphatidylcholine (PC) in high-pressure liquid chromatography (HPLC) was unveiled ('peak X') in normal human plasma. A second HPLC run of peak X HPLC fractions revealed the presence of PAF itself with concomitant disappearance of peak X. Beside PAF, immunoreactive apolipoproteins A-I and E were found in peak X. Also lipoproteins (Ls) purified using either ultracentrifugation or immunoaffinity chromatography yielded peak X and, in a second HPLC run, authentic PAF. L-free plasma was devoid of peak X. Finally, after preincubation with plasma, labeled PAF was found associated with Ls. Thus in human blood preformed PAF is bound in high amounts to Ls, a result of interest given the role of Ls and platelets in vascular diseases and the present knowledge on PAF biosynthesis.     

Cord blood and breast-milk antibodies in neonatal rotavirus infection.

Studies were carried out during an outbreak of rotavirus type 2 infection in a neonatal nursery to determine the protective role of antibodies in cord blood and breast milk. The range, distribution, and geometric mean titres of rotavirus-specific antibody in the cord blood were similar among rotavirus-positive and rotavirus-negative neonates, and the amount of virus excreted did not correlate with antibody levels. Despite the protective effect of breast feeding, the pattern of rotavirus-specific IgA and IgG antibodies in the expressed breast milk of mothers of babies who were rotavirus excreters and non-excreters was similar. Nevertheless, a higher proportion of expressed breast milk samples contained rotavirus-specific IgA group 2 (92%) and type 2 (97%) specific antibodies than type I (67%) antibodies, and the geometric mean titres of group 2 and type 2 specific antibodies were tenfold higher than type I antibodies. Among breast-fed babies who excreted rotavirus there was no correlation between type 2 rotavirus-specific IgA antibodies in expressed breast milk and the amount of neonatal virus excretion. These studies suggest that factors other than the rotavirus antibodies in expressed breast milk are of importance in preventing rotavirus infection in newborn infants.     

Cholesterol content of red blood cells and low-density lipoproteins in hypertriglyceridemia

The red blood cells and the low-density lipoproteins in hypertriglyceridemia have a lower ratio of unesterified cholesterol to phospholipid than normal. The low-density lipoproteins are also smaller and more dense in hypertriglyceridemia, and contain only 45% of the normal unesterified cholesterol mass. The phase behavior of the lipids shows that normal red cells and low-density lipoproteins are close to saturation with cholesterol, whereas in hypertriglyceridemia less cholesterol is present. Because newly secreted triacylglycerol-rich lipoproteins are poor in cholesterol, their excess production and transport in hypertriglyceridemia may prevent maintenance of the normal cholesterol content of blood cells and low-density lipoproteins. Partitioning of cholesterol into triacylglycerol-rich lipoproteins is able to account for significant fluxes of unesterified cholesterol in the plasma compartment.     

Interaction of lipoproteins in blood serum with steroid hormones

Interaction of human and serum lipoproteins with steroid hormones (corticosterone and cortisol) was studied. Methods of fluorescence quenching titration and equilibrium dialysis were used for quantitative evaluation of VLDL, LDL and HDL glucocorticoid-binding ability. Association constants were found to be 0.6-2.0 x 10(6) M-1 for corticosterone and 4.0-8.0 x 10(6) M-1 for cortisol. The number of binding sites varied from 3 to 300 for different classes of lipoproteins.     

Quantitative characteristics of interactions of blood lipoproteins and steroid hormones]

Human and serum lipoproteins interaction with steroid hormones (corticosterone and hydrocortisone) were studied. Methods of fluorescence quenching titration and equilibrium dialysis were used for quantitative evaluation of VLDL, LDL and HDL glucocorticoids binding ability. Association constants were found to be 0.6-2.0 x 10 M for corticosterone and 4.0-8.0 x 10 M for hydrocortisone. The number of binding sites ranged from 3 to 300 for different classes of lipoproteins. Our data suggest high specificity of serum lipoproteins binding with corticosterone and hydrocortisone.     

Interaction of prostaglandins with low-density lipoproteins in human blood

Interaction of prostaglandins (PG) with human plasma low density lipoproteins (LDL) was studied, using fluorescent spectroscopy and photoreactive labeling. It was demonstrated that PGE1 at low concentrations (less than 10(-9) M) induces specific lipid rearrangements on the surface of LDL globules. It was assumed that these rearrangements are brought about by the interaction of PG with apolipoprotein B to form short-living complexes. A possible mechanism and biological significance of the observed phenomenon are discussed.     

J blood group active lipoproteins extracted from bovine erythrocytes

Ghosts of J-positive bovine erythrocytes were frozen overnight, thawed the next day, washed with ion-free water, and then extracted with a water-n-pentanol mixture. After centrifugation, the aqueous phase contained a great deal of the membrane proteins and lipids in a soluble form along with the J blood-group activity. After preparative ultracentrifugation, about 2/3 of the J activity were recovered in the high-density lipoprotein fraction, while the low-density lipoprotein fraction contained 1/3 J activity. This result is consistent with our finding that on treatment of the stroma lipoproteins with dextran sulphate, about 2/3 of J activity were recovered in the supernatant, 1/3 in the precipitate. These fractions obtained by dextran sulphate treatment were characterized by protein and lipid assay.