Indicators of long chain polyunsaturated fatty acid status of exclusively breastfed infants at delivery and after 20-22 days

The fatty acid composition of plasma cholesterol esters (CE), erythrocytes (RBC) and mature milk from seven lactating women and their exclusively breastfed newborns, living on Dominica, were studied. Blood samples were taken from umbilical cord and mother at birth. A sample of breastmilk was collected on day 20-22 postpartum, together with a blood sample from the baby. At birth, cord blood plasma CE and RBC total long chain polyunsaturated fatty acid (LC-PUFA) contents were higher, and linoleic (18:2c, omega 6) and alpha-linolenic (18:3c, omega 3) acid contents lower, than in corresponding maternal compartments. Cord blood RBC LC-PUFA omega 3 content was lower and LC-PUFA omega 6 content higher than in maternal RBC. After birth, feeding with human milk led to a drop in LC-PUFA content in the plasma CE fraction, whereas RBC LC-PUFA content remained virtually constant. Current understanding of the origin and relative affinity of fatty acids incorporated in plasma CE and RBC suggests that RBC LC-PUFA content is a more reliable parameter for LC-PUFA status than plasma CE LC-PUFA content. The RBC LC-PUFA data suggest therefore that at birth the newborn has a lower LC-PUFA omega 3 status than the mother, and that this does not change during three weeks of exclusive breastfeeding (AU)

Evaluation of the double-quantum filter for the measurement of intracellular sodium concentration.

Evaluation of the double-quantum filter for sodium was performed on several sample series of bovine serum albumin in water. Both single-quantum (1Q) and double-quantum (2Q) measurements were obtained. The quality of the 2Q filter was found to be quite sensitive to pulse width setting. Ordinary 1Q measurements of sodium in albumin-containing solutions show 100% visibility. At high ionic strengths, the 2Q albumin results confirm earlier conclusions demonstrating the tendency for the albumin molecule to unfold under a variety of influences. At physiological sodium concentrations, the magnitude of the 2Q/1Q ratio is controlled not only by the concentration of albumin, but also by the solution pH. Non-zero, double-quantum signals were observed in physiological samples consisting of essentially intracellular material (packed red blood cells) as well as in extracellular material (plasma and urine). Measurements in human urine showed no 2Q signal. However, high-concentration NaCl solutions did produce real, measurable 2Q signals. Therefore, the 2Q filter does not measure intracellular sodium exclusively. Although packed red blood cells gave the highest 2Q/1Q ratio (8.5 x 10(-3), plasma gave a very considerable 2Q/1Q ratio (2.3 x 10(-3). Because of its relatively high extracellular concentration, extracellular sodium may give a greater absolute 2Q signal than intracellular sodium in unmodified tissue samples. Based on these data, we conclude that a 2Q filter will not provide a useful measurement of intracellular sodium in in vivo tissue samples.

Correlation between in vivo hemolysis and the amount of red cell-bound IgG measured by flow cytometry.

A flow cytometry method was used to compare the amount of red cell (RBC)-bound IgG in 73 patients with and without immune hemolytic anemia (IHA). The positive results in 10 of the direct antiglobulin tests (DATs) were idiopathic, and those in 25 were due to methyldopa therapy; 38 of the 73 DAT-positive patients were babies born to women with IgG alloantibodies of potential clinical significance. Normal blood donors with (n = 30) and without (n = 121) positive DATs were also tested. RBCs that had been strongly sensitized (4+ indirect antiglobulin test) in vitro with different quantities of IgG anti-D, but that had similar antiglobulin test (AGT) titration scores, could easily be differentiated by flow cytometry. The mean percent fluorescence of RBCs, incubated with fluorescein-labeled anti-IgG, from neonatal patients with IHA was higher than that of RBCs from those without IHA, but there was no statistical difference in the other groups. There was considerable overlap in the respective ranges of percent fluorescence of RBCs from patients with and without IHA in all groups. It was not possible to define a clear quantitative threshold differentiating patients with IHA from those without. Although flow cytometry was more precise and reproducible than standard serology (e.g., AGT titration scores), correlations of the amount of RBC-bound IgG and in vivo hemolysis were similar.

Within-person variance in biochemical indicators of iron status: effects on prevalence estimates.

The effect of within-person variance on prevalence estimates from population distributions based on a single measurement was examined for hematologic and iron-status indicators collected in the Hispanic Health and Nutrition Examination Survey (HHANES). Within-person to between-person variance ratios (W:Bs) were estimated for 11 indicators by using data from 80 persons who provided blood twice in HHANES. Distributions of selected iron-status indicators from 20-44-y-old Mexican American females from HHANES were adjusted for within-person variance by using the W:B estimates, and prevalences of low values based on the original and adjusted distributions were compared. W:B were less than 1 for the majority of the indicators. Nonetheless, prevalences of low values from the original distributions were inflated when commonly used cutoff values were applied. Within-person variance in serum analytes needs to be controlled when the prevalence of a condition in populations is assessed.

Vitamin E status during dietary fish oil supplementation in rheumatoid arthritis.

The primary objective of this study was to determine whether it is the fish oil itself or the alpha-tocopherol that is added to the fish oil preparations (to prevent peroxidation) that is responsible for the beneficial effects of dietary supplementation with fish oil in patients with rheumatoid arthritis (RA). One group of RA patients took fish oil supplements and another group took alpha-tocopherol-enriched coconut oil supplements (placebo controls), both for 3 months. Clinical and laboratory indices of RA activity in relation to cellular and plasma vitamin E levels were assessed at the beginning and the end of the trial. The results of the study provide evidence that the beneficial effects of fish oil supplementation cannot be ascribed to the antioxidizing properties of the alpha-tocopherol per se.

Enhancement of recovery from psychiatric illness by methylfolate.

41 (33%) of 123 patients with acute psychiatric disorders (DSM III diagnosis of major depression or schizophrenia) had borderline or definite folate deficiency (red-cell folate below 200 micrograms/l) and took part in a double-blind, placebo-controlled trial of methylfolate, 15 mg daily, for 6 months in addition to standard psychotropic treatment. Among both depressed and schizophrenic patients methylfolate significantly improved clinical and social recovery. The differences in outcome scores between methylfolate and placebo groups became greater with time. These findings add to the evidence implicating disturbances of methylation in the nervous system in the biology of some forms of mental illness.

Treatment of sickle cell anemia with hydroxyurea and erythropoietin.

BACKGROUND: Hydroxyurea increases the production of fetal hemoglobin (hemoglobin F) in patients with sickle cell anemia and therefore has the potential for alleviating both the hemolytic and vaso-occlusive manifestations of the disease. There is preliminary evidence that recombinant human erythropoietin may also increase hemoglobin F production. METHODS AND RESULTS: We treated five patients with sickle cell disease with escalating doses of intravenous erythropoietin for eight weeks. Three of these patients were subsequently treated with daily doses of oral hydroxyurea. After the optimal dose was determined, erythropoietin was then given along with hydroxyurea for four weeks. Treatment with erythropoietin, either alone or in combination with hydroxyurea, had no significant effect on the percentage of hemoglobin F-containing reticulocytes (F reticulocytes) or red cells (F cells). In contrast, hydroxyurea treatment was associated with a 3-to-25-fold increase in F reticulocytes, a 1.6-to-7-fold increase in F cells, and a 2.3-to-16-fold increase in the percentage of hemoglobin F. In all three patients given hydroxyurea, treatment with this drug was associated with reduced hemolysis, shown by decreases in serum bilirubin and lactic dehydrogenase and prolongation of red-cell survival. Hydroxyurea treatment also resulted in a decrease in the percentage of irreversibly sickled cells and sickling at partial oxygen saturation, an increase in oxygen affinity and total red-cell cation content, and a reduction in potassium-chloride cotransport. All three patients had a decrease in the number of pain crises. CONCLUSIONS: This study confirms that hydroxyurea therapy increases hemoglobin F production and provides objective evidence that hydroxyurea reduces the rate of hemolysis and intracellular polymerization of hemoglobin S. In contrast, recombinant human erythropoietin, whether alone or in combination with hydroxyurea, offers no measurable benefit.

Gametic equilibrium between 24 polymorphic markers.

Pairs of unlinked genetic markers (blood cell antigens and enzymes and serum proteins) were tested for gametic equilibrium (GE) in data from 508 unrelated individuals from different regions of North America. A total of 24 markers were considered in the study. Only 14 of 262 pairs (5.3%) of markers deviated from GE at the 5% significance level and only 6 pairs (2.3%) remained in significant disequilibrium after accounting for genetic heterogeneity among regional groups. The particular combinations of alleles or one-locus genotypes that showed significant association were identified in case they might be replicated in future studies. On the basis of this study alone, however, there is no reason to suspect disequilibrium between the pairs of markers studied.

The levels of adenine nucleotides and pyridine coenzymes in red blood cells from the newborn, determined simultaneously by HPLC.

The concentrations of ATP, ADP, AMP; NADP and NADPH; NAD and NADH were determined in erythrocytes from healthy newborns and compared with those obtained in healthy adults. No significant differences were found for the adenine nucleotide concentrations, but NADH levels were reduced in newborn erythrocytes, with a consequent increase in the NAD/NADH ratio. Moreover, in newborn erythrocytes increased levels of NADP were observed, with a consequent increase in the NADP/NADPH ratio and a decrease in the NAD/NADP ratio. These results indicate the need to use reference values of the ratios NAD/NADH, NADP/NADPH and NAD/NADP from healthy newborns in the study of syndromes affecting the metabolism of erythrocytes in the newborn.

Molecular analysis of insertion/deletion mutations in protein 4.1 in elliptocytosis. I. Biochemical identification of rearrangements in the spectrin/actin binding domain and functional characterizations.

Protein 4.1 (80 kD) interacts with spectrin and short actin filaments to form the erythrocyte membrane skeleton. Mutations of spectrin and protein 4.1 are associated with elliptocytosis or spherocytosis and anemia of varying severity. We analyzed two mutant protein 4.1 molecules associated with elliptocytosis: a high molecular weight 4.1 (95 kD) associated with mild elliptocytosis without anemia, and a low molecular weight 4.1 (two species at 68 and 65 kD) associated with moderate elliptocytosis and anemia. 4.1(95) was found to contain a approximately 15-kD insertion adjacent to the spectrin/actin binding domain comprised, at least in part, of repeated sequence. 4.1(68/65) was found to lack the entire spectrin-actin binding domain. The mechanical stability of erythrocyte membranes containing 4.1(95) was identical to that of normal membranes, consistent with the presence of an intact spectrin-actin binding domain in protein 4.1. In contrast, membranes containing 4.1(68/65) have markedly reduced mechanical stability as a result of deleting the spectrin-actin binding domain. The mechanical stability of these membranes was improved following reconstitution with normal 4.1. These studies have thus enabled us to establish the importance of the spectrin-actin binding domain in regulating the mechanical stability of the erythrocyte membrane.

Fish-oil concentrate: effects on variables related to cardiovascular disease.

Sixty-four male, healthy volunteers aged 35-45 y were randomly assigned to receive (as 1-g capsules) either 14 g fish-oil concentrate/d (55% n-3 fatty acids) or 14 g olive oil/d for 6 wk. Plasma fibrinogen was reduced by 13% and serum triglycerides by 22% after fish-oil supplementation ended. Three weeks after supplementation ended both variables were back to baseline values. An appreciable increase in the ratio of eicosapentaenoic acid to arachidonic acid (EPA:AA) in plasma eicosapentaenoic acid to arachidonic acid (EPA:AA) in plasma and red blood cell phospholipids occurred during the fish-oil intake. High-density-lipoprotein (HDL) cholesterol and HDL2 activity tended to be lowered by fish-oil supplementation. Systolic and diastolic blood pressures, serum cholesterol, gamma-glutamyltransferase, blood glucose, and monocyte low-density-lipoprotein receptor activity did not differ significantly between the two groups. The reduction in plasma fibrinogen concentration seems of special interest because this variable in several recent studies emerges as a separate cardiovascular risk factor with a high predictive value.

Folate status of Mexican American, Cuban, and Puerto Rican women.

The objective of this study was to estimate the prevalence of low serum and red blood cell (RBC) folate values of Mexican American (MA), Cuban (C), and Puerto Rican (PR) women examined in the Hispanic Health and Nutrition Examination Survey, 1982-1984. Serum and RBC folate were determined for all women aged 18-44 y by use of a radio-assay kit. The percent of women with low serum folate (less than 6.8 nmol/L) was 11.9% for MA, 10.1% for C, and 8.1% for PR. The prevalence of low concentrations of RBC folate (less than 363 nmol/L) was 7.8%, 16.7%, and 13.6% for MA, C, and PR, respectively. The percentages of women with reduced tissue stores of folate were 4.3% for MA, 6.0% for C, and 4.0% for PR. Years of education completed and poverty status did not significantly affect folate concentrations; however, the prevalence of low folate concentrations among users of vitamin or mineral supplements was significantly lower than it was among nonusers in selected subgroups.

Alteraciones electrolíticas en la hipertensión arterial esencial / Electrolytic changes in essential arterial hypertension

Se determinaron las concentraciones de sodio y potasio en plasma sanguíneo, saliva y eritrocitos en 3 grupos de pacientes. Grupo A (n=27) normotensos sin antecedentes familiares de hipertensión arterial y grupo C (n=35), individuos que padecían de hipertensión arterial. Se encontró un aumento estadísticamente significativo (p < 0,05) del sodio y una disminución del potasio intraeritrocitario, así como un aumento del sodio y potasio en la saliva en el grupo C con respecto a los demás grupos estudiados. No hubo diferencias significativas entre los grupos A y B en ninguno de los parámetros.

Characterization of the binding of Actinomyces naeslundii (ATCC 12104) and Actinomyces viscosus (ATCC 19246) to glycosphingolipids, using a solid-phase overlay approach.

Actinomyces naeslundii (ATCC 12104) and Actinomyces viscosus (ATCC 19246) were radiolabeled externally (125I) or metabolically (35S) and analyzed for their ability to bind glycosphingolipids separated on thin layer chromatograms or coated in microtiter wells. Two binding properties were found and characterized in detail. (i) Both bacteria showed binding to lactosylceramide (LacCer) in a fashion similar to bacteria characterized earlier. The activity of free LacCer was dependent on the ceramide structure; species with 2-hydroxy fatty acid and/or a trihydroxy base were positive, while species with nonhydroxy fatty acid and a dihydroxy base were negative binders. Several glycolipids with internal lactose were active but only gangliotriaosylceramide and gangliotetraosylceramide were as active as free LacCer. The binding to these three species was half-maximal at about 200 ng of glycolipid and was not blocked by preincubation of bacteria with free lactose or lactose-bovine serum albumin. (ii) A. naeslundii, unlike A. viscosus, showed a superimposed binding concluded to be to terminal or internal GalNAc beta and equivalent to a lactose-inhibitable specificity previously analyzed by other workers. Terminal Gal beta was not recognized in several glycolipids, although free Gal and lactose were active as soluble inhibitors. The binding was half-maximal at about 10 ng of glycolipid. A glycolipid mixture prepared from a scraping of human buccal epithelium contained an active glycolipid with sites for both binding specificities.

Effects of exercise and adrenaline on equine erythrocyte ATP content.

To investigate the claim that equine erythrocytes released from the spleen are older cells than those found at rest in the circulation, the 2,3, diphosphoglycerate (2,3 DPG), adenosine triphosphate (ATP) and creatine concentration of erythrocytes before and following splenic emptying were examined. Normal values for thoroughbreds (43) and ponies (10) at rest were established. Following either exercise or intravenous injection of adrenaline in six thoroughbreds, there was an increase in erythrocyte creatine content and a decrease in ATP concentration. Exercise produced a slight increase in 2,3 DPG while no change occurred with adrenaline. In two splenectomised ponies adrenaline only produced a decrease in erythrocyte ATP, with no change in creatine or 2,3 DPG content. It was concluded that erythrocytes released from the spleen are not aged cells. However, the stimuli used produced a decrease in ATP content which may affect the properties of the erythrocytes.

Reference values of magnesium and potassium in mononuclear cells and erythrocytes of children.

Reference values for magnesium and potassium contents of mononuclear cells and erythrocytes were estimated in cord blood and in children from infancy through adolescence. No differences were detected between results for boys and girls. The mononuclear magnesium content was independent of age and was within the adult range of values. No significant correlation was shown between magnesium in serum and in mononuclear cells. Mononuclear potassium also showed no age-related differences. The correlation between magnesium and potassium contents in mononuclear cells was significant: however, the correlation was lower when the magnesium and potassium contents were expressed in terms of protein potent: micromoles or millimoles per gram of protein, respectively. The concentration of magnesium in erythrocytes was significantly lower in cord blood and during the first month of life, compared with that at older ages, and showed no significant correlation with serum magnesium. The concentration of erythrocyte potassium was independent of age and showed a low but significant correlation with erythrocyte magnesium content.