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Biomedical subjects

S E Carlson

Publications and source records attributed to S E Carlson.

At least 55 records · Page 3Linked to original sources
PubMed1991

Effects of different levels of intravenous alpha-linolenic acid and supplemental breast milk on red blood cell docosahexaenoic acid in very low birth-weight infants.

Preterm infants weighing less than 1,500 g were started on total parenteral nutrition (TPN) if unable to tolerate full enteral feedings. They were randomly assigned to receive intravenous lipids containing either 4.2 or 9.0% alpha-linolenic acid to assess the effect on red blood cell (RBC) phospholipid polyenoic fatty acid composition, particularly docosahexaenoic acid (22:6n3) (DHA). DHA ultimately comes from alpha-linolenic acid (18:3n3), although there is evidence in human preterm infants that they require preformed DHA. After 1 week of TPN, infants were started on gradually increasing amounts of enteral feeding, breast milk, if elected by mothers, or premature milk formula (Preemie Enfamil). RBC phospholipid fatty acids were measured weekly. Results were evaluated comparing samples from week 1 and week 6. Supplying 9% alpha-linolenic acid in intravenous lipids did not prevent a fall in DHA by 6 weeks; however, infants receiving breast-milk feeding did not have a significant decrease in DHA. Studies are needed to evaluate supplying DHA in intravenous lipids.

Docosahexaenoic Acids↗
PubMed1991

Plasma cholesterol and lipoprotein levels during fetal development and infancy.

Intrauterine changes in plasma cholesterol and lipoprotein concentrations have been linked to the development of the adrenal gland (utilization of cholesterol) and liver (production of cholesterol by new synthesis). At term birth, racial and gender differences have been observed with white compared to black, and female compared to male, infants having higher cholesterol concentrations. Within hours of the beginning of oral feeding, total and LDL cholesterol rise significantly. Little further increase occurs after 7 days, and the concentration seen after this time is highly dependent upon the cholesterol and polyunsaturated fat content of the diet. By 12 months of age, investigators cease to find any effect of the milk source fed earlier in infancy on cholesterol and lipoproteins. This is not evidence that diet no longer influences cholesterol and lipoprotein concentrations, but only that individual lipid intakes are varied and difficult to quantitate. Cross-cultural comparisons of infants at this age in fact provide strong suggestive evidence that a large environmental component determines the circulating cholesterol and lipoprotein concentrations seen at one year and beyond.

Cholesterol↗
PubMed1991

Long-term feeding of formulas high in linolenic acid and marine oil to very low birth weight infants: phospholipid fatty acids.

Red blood cell (RBC) phospholipids of infants fed human milk compared with formula have more arachidonic acid (AA) and docosahexanoic acid (DHA). The addition of low levels of marine oil to infant formula with 0.6 to 2.0% alpha-linolenic acid (LLA, 18:3n-3) prevented declines in DHA in formula-fed infants; however, the feeding trials were short (4 to 6 wk), LLA concentrations were low compared with current formulas (3.0 to 5.0% LLA), and the formulas were unstable. Trials with stable formulas were necessary to determine if dietary DHA could maintain phospholipid DHA after discharge from the hospital and, in fact, if it was necessary with higher intakes of LLA. The results of acute (4 wk) and extended (to 79 wk postconception) feeding of such formulas on RBC and plasma phospholipid AA and DHA are reported here. Control formulas were identical to commercially available formulas. Experimental formulas differed only in the addition of small amounts of marine oil. DHA in RBC and plasma phosphatidylethanolamine (PE) declined during four weeks of feeding but not if marine oil provided DHA (0.2% or 0.4%) and plasma phospholipid AA (g/100 g) decreased with time and marine oil feeding. Extended feeding with marine oil accounted for half the DHA in RBC and plasma phosphatidylethanolamine at equilibrium; however, RBC (g/100 g) and plasma AA (g/100 g; mg/L plasma) decreased progressively until late infancy and were depressed further by marine oil.(ABSTRACT TRUNCATED AT 250 WORDS)

Arachidonic Acid↗
PubMed1989

Physical properties of aerosols produced by dermabrasion.

Medical personnel who perform dermabrasions are exposed to airborne blood and tissue fragments. The safety or hazards of exposure to such aerosols have not been adequately studied. Using scanning electron microscopy, the air density and size distribution of particles produced during dermabrasion were analyzed. Such particles are of sufficient size to allow for access to and retention by mucosal and pulmonary surfaces. Transmission electron microscopy reveals amorphous particles without discernible cell membranes. Commonly used personnel protection standards do not prevent respiration of these particulates. Mathematical estimation of particle size production allows extrapolation of these data to other rotary instrument applications.

Aerosols↗
PubMed1988

Intracerebral hemorrhage complicating intravenous tissue plasminogen activator treatment.

Tissue plasminogen activator's thrombolytic action is relatively specific for fibrin; however, systemic bleeding can occur in patients, especially when heparin is simultaneously administered. We describe two cases of intracerebral hemorrhage from a cohort of 450 patients (0.44%) treated at one institution with tissue plasminogen activator and heparin for acute myocardial infarction. A pooled worldwide review of 5258 cases from several clinical protocols for treatment of acute myocardial infarction, using tissue plasminogen activator from one source, revealed a similar overall incidence of 0.68%. The incidence of intracerebral hemorrhage may be reduced by lowering the total dose of tissue plasminogen activator or by reducing the infusion rate and duration. The incidence of central nervous system hemorrhage with tissue plasminogen activator is within the range reported with streptokinase, but because equal coronary artery thrombolytic doses are not known, no definitive comparison is possible.

Aphasia↗
PubMed1988

Histamine and ascorbic acid: a survey of women in labor at term and significantly before term.

In ascorbic acid-requiring species (human, guinea pig), elevations of circulating histamine occur as the result of marginal ascorbic acid status. Marginal ascorbic acid status during pregnancy is associated with preeclampsia, abruption, and prematurity. Furthermore, circulating histamine is known to be elevated in these complications perhaps as a result of placental dysfunction which diminishes normal placental histaminase. We hypothesized that women with preeclampsia and premature labor would have elevated histamine and the lowest concentrations of ascorbic acid. Plasma total whole blood histamine and ascorbic acid were surveyed in women in term (T) and preterm (PT) labor. Blood histamine was elevated in PT compared to T labor but so was plasma ascorbate, indicating that marginal ascorbate status does not cause the elevated circulating histamine observed in PT. However, marginal ascorbate status concomitant with reduced placental histaminase may contribute to further increases in circulating histamine and to any pathology which might result from elevated histamine. Regression analysis of histamine on ascorbate for T and PT labor revealed a significant inverse relationship between ascorbate and histamine only in PT labor (p less than 0.027). An unexpected finding was that a history of maternal cigarette smoking, to a degree which resulted in marginal ascorbic acid status, confounded the relationship between ascorbate and circulating histamine in T labor.

Adult↗
PubMed1987

Effect of fish oil supplementation on the n-3 fatty acid content of red blood cell membranes in preterm infants.

Very low birth weight infants demonstrate significant reductions in red blood cell membrane docosahexaenoic acid (DHA, 22:6n-3) following delivery unless fed human milk. The purpose of the present study was to determine if a dietary source of DHA (MaxEPA, R. P. Scherer Corporation, Troy, MI) could prevent the decline in red blood cell phospholipid DHA in very low birth weight infants whose enteral feeding consisted of a preterm formula without DHA. Longitudinal data were obtained on membrane phospholipid DHA in both unsupplemented and MaxEPA-supplemented infants by a combination of thin-layer and gas chromatography. These infants (n = 39) ranged in age from 10 to 53 days at enrollment (0 time). At enrollment, phospholipid DHA and arachidonic acid (20:4n-6) were inversely correlated with age in days. During the study, mean red blood cell phospholipid DHA declined without supplementary DHA as determined by biweekly measurement, but infants supplemented with MaxEPA maintained the same weight percent of phospholipid (phosphatidylethanolamine, phosphatidylcholine, and phosphatidylserine) DHA as at enrollment. The pattern of red blood cell phospholipid fatty acids in supplemented infants was similar to that reported for preterm infants fed human milk.

Clinical Trials as Topic↗
PubMed1987

Increase in plasma phospholipid docosahexaenoic and eicosapentaenoic acids as a reflection of their intake and mode of administration.

The fatty acid, docosahexaenoic acid (DHA, 22:6n-3), is a major constituent of red blood cell phosphatidylethanolamine and phosphatidylserine at birth but declines in all phospholipid classes following preterm delivery unless the diet contains DHA. A bolus of fish oil prevented declines in DHA of red cell phospholipids (phosphatidylethanolamine, phosphatidylcholine, and phosphatidylserine) during 4 to 6 wk of feeding, with red blood cell DHA indistinguishable from that of infants fed human milk. The amount of DHA fed was almost an order of magnitude greater than usually provided by human milk, however, suggesting poor absorption of fish oil by preterm infants. The purpose of these studies was to determine if uptake of fish oil DHA could be improved by dispersion in preterm formula. Since plasma phospholipids rapidly reflect changes in dietary fatty acid composition, DHA uptake was assessed by fatty acid analysis of plasma phosphatidylethanolamine and phosphatidylcholine. All groups receiving fish oil (both bolus and dispersed) demonstrated a rise in plasma phospholipid phosphatidylethanolamine DHA. Infants receiving 11 mg/kg/day DHA from dispersed fish oil, however, appeared to absorb as much or more as those receiving 71 mg/kg/day DHA in a bolus. The lower intake of DHA provided only 0.2% of total dietary fatty acids (human milk typically provides 0.1 to 0.3%). This study, in conjunction with an earlier report, demonstrates the feasibility of 1) long-term maintenance of red cell membrane DHA by its inclusion in infant formula and 2) DHA maintenance by "physiological" intakes of DHA; i.e. the amount provided by human milk.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1986

Docosahexaenoic acid status of preterm infants at birth and following feeding with human milk or formula.

The docosahexaenoic acid (DHA) status of preterm infants (less than 32 wk gestation) was measured as the molar percent of DHA in individual red blood cell phospholipids: 1) in cord venous blood immediately following delivery, 2) after infants were receiving greater than 60 kcal X kg X day of energy from oral-gastric feedings, and 3) at a mean of 7 wk later. Infants on full feeding received either preterm human milk or formula. The DHA concentration of all phospholipid classes declined between birth and the time at which enteral feedings constituted the primary source of energy. Subsequent feeding with preterm human milk increased the molar percent of red blood cell phospholipid DHA, while DHA declined further in infants fed formula. Infants fed human milk compared to those fed formula had a significantly higher molar percent of DHA in all red blood cell phospholipids studied.

Birth Weight↗
PubMed1986

High fat diets varying in ratios of polyunsaturated to saturated fatty acid and linoleic to linolenic acid: a comparison of rat neural and red cell membrane phospholipids.

The polyunsaturated-saturated (P/S) fatty acid, and linoleic-linolenic (18:2n6/18:3n3) acid ratios of diets fed to rats were varied independently during pregnancy, lactation and, in the young, for 8 d after premature weaning. The intent was to alter the proportion of membrane phospholipid fatty acids derived from 18:2n6 and 18:3n3 in the developing rat, and to compare changes in very-long-chain polyunsaturated fatty acids in membranes from the central nervous system with those of the red blood cell. All experimental diets contained 40% of energy from fat. Similar relative changes in phosphatidylethanolamine (PE) and phosphatidylcholine (PC) fatty acid pattern occurred in both neural and red blood cell membranes when dietary 18:2n6/18:3n3 was increased from 7 to 240. Docosapentaenoate (22:5n6) from 18:2n6 increased, and docosapentaenoate (22:5n3) and docosahexaenoate (22:6n3) from 18:3n3 decreased in both types of membranes. On the other hand, P/S ratios of 0.3 and 1.6 at a constant ratio of 18:2n6/18:3n3 produced identical membrane phospholipid fatty acid patterns. Both red blood cell and neural membranes show the same relative effects of modification of dietary lipids on the composition of very-long-chain polyunsaturated fatty acids.

Animals↗
PubMed1986

Oral and intraperitoneal administration of N-acetylneuraminic acid: effect on rat cerebral and cerebellar N-acetylneuraminic acid.

Rat pups were administered N-acetylneuraminic acid (NANA) by i.p. injection or via a feeding catheter for eight consecutive days beginning on d 14 of life. All pups were given the identical dose: 1.0 mg on d 1 and 2 and 1.2 mg on the remaining days, or approximately 20 mg/kg body weight per day. A control group was injected i.p. with glucose instead of NANA. On the morning of d 25, pups were decapitated, and the heads were frozen immediately in liquid nitrogen. The brains were later dissected and analyzed for both cerebral and cerebellar ganglioside and glycoprotein NANA. Administration of NANA by both oral and i.p. routes resulted in significantly more cerebral and cerebellar ganglioside and glycoprotein NANA than did glucose injection (with the exception of cerebellar glycoprotein NANA after NANA intubation). There were no significant differences in NANA concentration in these brain fractions for the two routes of NANA administration.

Administration, Oral↗
PubMed1985

N-acetylneuraminic acid concentrations in human milk oligosaccharides and glycoproteins during lactation.

Human milk contains a variety of N-acetylneuraminic acid (NANA)-containing oligosaccharides, but the expected range of intake of sialic acid in this form by infants fed human milk is unknown. Two quite different amounts have been reported: 120 mg/liter in pooled, mature human milk (1) and 1400 mg/liter in the milk of a single woman on the 1st day of lactation (2). The normal range of NANA intake in human milk glycoproteins likewise does not appear to have been analyzed previously. Data presented here indicate that both human milk oligosaccharide and glycoprotein NANA decline exponentially over the first 2 months of lactation, decreasing little thereafter. During the first 2 months of lactation, milk from women delivering at term cannot be distinguished from that of women delivering significantly before term (less than 32 wks gestation) with regard to oligosaccharide and glycoprotein NANA. The parallel decrease of sialic acid in these fractions suggests a relationship between sialydation of human milk oligosaccharides and glycoproteins. Human milk NANA concentrations are discussed with regard to reports that exogenous administration of NANA can increase cerebral and cerebellar concentrations of NANA in glycoproteins and gangliosides, and produce long term changes in behavior in rats.

Animals↗
PubMed1985

Human milk nonprotein nitrogen: occurrence and possible functions.

Human milk contains a wide variety of nitrogenous compounds in addition to protein. Recognition of the special roles these compounds can perform raises questions about their availability from human milk, and, ultimately, their significance in the development of the human newborn. While it is likely that the major categories of compounds contributing to the nonprotein-nitrogen fraction of human milk have been identified, the true variety of nitrogenous compounds within the peptide fraction of human milk is only beginning to be recognized and appreciated. If predictions can be made from those peptides already identified, epidermal growth factor, delta-sleep inducing peptide, somatomedin-C/insulin-like growth factor I and the peptide hormones, further elucidation of the specific peptides that contribute to this fraction of human milk promises to be especially exciting. With each new published report, the recognized chemical gap between human milk and proprietary formulas increases. There is increasing evidence that human milk produced by a well-nourished woman is a chemical mixture uniquely suited for the developmental stage of her infant. Whether these differences confer developmental advantages to the infant fed human milk, advantages not enjoyed by infants fed formula, is less easily determined. Attempts to answer this question must take into account the relative physiological maturity of the infant at birth. There is a distinct possibility that infants born early in the last intrauterine trimester will derive more benefit from receiving mother's milk than those infants nourished in utero to term.

Amino Acids↗
PubMed1983

Protein and energy requirements of term and preterm infants.

Little new evidence has been presented to warrant altering protein and energy requirements of term infants. Breast milk remains the benchmark. Feeding preterm infants, however, presents multiple challenges only now beginning to be faced. In the past, respiratory distress and infections were such emergencies that little attention was given to nutritional needs. While optimal rates of growth are not even now known, nor even measurements to tell what is "optimum", at least the requirements for certain growth rates which are not accompanied by undue stress can be met by pre-term fresh breast milk and specially designed formulas.

Amino Acids↗
PubMed1982

The effect of variations in dietary fatty acids on the fatty acid composition of erythrocyte phosphatidylcholine and phosphatidylethanolamine in human infants.

Human milk, or one of two formulas that derive their fat from vegetable oil, was fed to infants from birth until 4.5 to 6 months of age. Infants fed human mild received 2% of total fatty acids as 20 to 22 carbon polyunsaturated fatty acids. These fatty acids which are not found in vegetable oils, are synthesized by animals from the essential vegetable-derived fatty acids, linoleic and alpha-linolenic acids. Enfamil (Mead Johnson, Evansville, IN) contained three times as much linoleic acid as human milk or SMA (Wyeth Laboratories, Philadelphia, PA); however, the ratios of linoleic/alpha-linolenic acid were 9.0, 18.8, and 11.7 for Enfamil, human milk, and SMA, respectively. Erythrocyte phosphatidylethanolamine and phosphatidylcholine in infants fed human milk had significantly more 20 to 22 carbon polyunsaturated fatty acids than did those infants consuming only vegetable fat. Concentrations of 20 to 22 carbon polyunsaturated fatty acids in the erythrocyte membrane phosphatidylethanolamine and phosphatidylcholine of SMA and Enfamil-fed infants were similar despite very significant differences in the amount of dietary 18 carbon precursor. The degree of unsaturation of both erythrocyte phosphatidylethanolamine and phosphatidylcholine was highest with the feeding of human milk compared to the formulas, but the relative concentration of the four major erythrocyte phospholipids, and the ratio of membrane phosphorus/cholesterol were not affected by these diets.

Breast Feeding↗