Efficacy of dietary arachidonic acid provided as triglyceride or phospholipid as substrates for brain arachidonic acid accretion in baboon neonates

Arachidonic acid (AA) is a long-chain polyunsaturate (LCP) present in human breast milk as both triglyceride (TG) and as phospholipid (PL). There has been little attention to the metabolic consequences of lipid form of AA in infant formulas. Our objective was to investigate the efficacy of dietary TG and PL as carriers of AA for accretion in the brain and associated organs of term baboon neonates consuming a formula with LCP composition typical of human milk. TG and phosphatidylcholine (PC) with [U-(13)C]-AA in the sn-2 position and with unlabeled 16:0 in the remaining positions (TG-AA* or PL-AA*, respectively) were used as tracers to study the tissue AA* incorporation. Baboon neonates received a single oral dose of either TG-AA* (n = 3) or PL-AA* (n = 4) at 18-19 d of life. Tissues were obtained 10 d later (28-29 d of life) and isotopic enrichment was measured. In the brain, 4.5% of the PL-AA* dose and 2.1% of the TG-AA* dose were recovered as brain AA*, respectively, indicating that PL was about 2.1-fold more effective than TG as a substrate for brain AA accretion. Preferential incorporation of PL-derived AA* over TG source of AA* was also observed in the liver, lung, plasma, and erythrocytes. Because of the quantitative predominance of TG-AA in formula, total brain AA accretion, expressed as absolute weight, was 5.0-fold greater from TG-AA than from PL-AA. We estimate that about half of postnatal brain AA accretion is derived from dietary preformed AA in term baboon neonates consuming a formula with lipid composition similar to that of human milk.     

High plasma ascorbic acid levels in premature neonates with intraventricular hemorrhage

The accumulation of ascorbic acid in the brain by active transport establishes a high brain-plasma gradient of the vitamin. An insult to the CNS may result in an efflux of ascorbate into the circulation with a consequent rise of plasma levels. We measured plasma ascorbic acid levels in premature neonates on days 1, 3, and 5 of life, and the infants underwent ultrasonographic examination to detect intracranial hemorrhage. Neonates with intraventricular hemorrhage sustained significantly higher plasma ascorbate levels than their controls. Infants with massive bleeding had higher levels than those with a smaller hemorrhage. These results suggest that an efflux of ascorbic acid into the circulation occurs secondary to intracranial hemorrhage.     

Characteristics of obese children with low content of arachidonic acid in plasma lipids

BACKGROUND: Although there have been many studies on the relationship between obesity and long-chain polyunsaturated fatty acid (LCPUFA), the results and their interpretation are controversial, especially in children. Arachidonic acid (AA), the product of n-6 LCPUFA, is reported to be related to insulin resistance. The purpose of the present paper was to investigate the LCPUFA profile in obese children and mechanisms that contribute to reduced AA content. METHOD: An age- and sex-matched control study was performed. The study subjects were 59 obese children (mean age, 11.8 years) and 53 healthy non-obese children (mean age, 12.5 years). The study parameters included anthropometric measurements, serum lipids, leptin and fatty acid composition in plasma. RESULTS: Plasma fatty acids in obese children had lower linoleic acid (P < 0.0001) and higher dihomo-gamma-linolenic acid (P = 0.0004) than those in non-obese children. In all subjects combined, delta-6 desaturase (D6D) index (ratios of [C 18:3n-6+C 20:2n-6]/C 20:4n-6 or C 20:4n-6/C 18: 2n-6) correlated with leptin (P < 0.0001). There was no significant difference in AA content between obese and non-obese. However, the AA content was low (相似文献   

Decreased lipid intake reduces morbidity in sick premature neonates

For an investigation of the clinical sequelae of parenteral lipid infusions during the first week of life, 42 neonates (less than 1750 gm birth weight) were randomly assigned to receive parenteral alimentation with (IL) (Vitrum) or without a parenteral lipid infusion (NL) for 5 days. Follow-up clinical status was monitored and compared, and plasma prostaglandin levels were analyzed. Chronic lung disease was increased in duration and tended to be more severe after lipid administration. The number of days of mechanical ventilation (37 +/- 35 vs 21 +/- 18) and supplemental oxygen therapy (51 +/- 39 vs 28 +/- 23) was significantly increased in the IL group. Five IL infants developed stage 3 bronchopulmonary dysplasia, in comparison with none of the NL infants. Seven IL infants were discharged on a regimen of supplemental oxygen therapy versus none of the NL infants. Thromboxane B2 levels were significantly increased in the babies receiving Vitrum. We conclude that early administration of Vitrum in the premature neonate is associated with increased respiratory difficulty in the ensuing weeks of life.     

Quantification of L-type fatty acid binding protein in the urine of preterm neonates

We measured urinary excretion of L-type fatty acid binding protein (L-FABP) in preterm neonates on days 1, 5-10, and 25-30 of life. Urinary L-FABP levels (expressed as the ratio to creatinine) in preterm neonates were considerably higher than those of healthy adults. They did not change significantly during the study period. Urinary L-FABP levels showed significant positive correlation with those of urinary N-acetyl-beta-D-glucosaminidase activity on day 1, and with those of 8-hydroxy-2'-deoxyguanosine on days 25-30. These results suggest that L-FABP is expressed in the neonatal kidney. Our results may also point to potential effects of proximal tubular damage and oxidative stress on urinary excretion of L-FABP.     

Docosahexaenoic acid and arachidonic acid in infant development

Docosahaxaenoic acid and arachidonic acid are highly concentrated in the central nervous system. The amount of these fatty acids in the central nervous system increases dramatically during the last intrauterine trimester and the first year of life. A central question of research conducted during the past 20 years is if the essential fatty acid precursor of docosahexaenoic acid is sufficient to achieve optimal DHA accumulation in the central nervous system and, therefore, infant development. The important role of non-human primate studies in characterising the behavioral effects of n-3 essential fatty acid deficiency and subsequent low brain DHA accumulation, the difference between essential fatty acid deficiencies and conditional deficiencies of docosahexaenoic acid and arachidonic acid, and the evidence that human infants have a conditionally essential need for docosahexaenoic acid and, perhaps, for arachidonic acid are summarised. The current suggestive evidence for several possible mechanisms underlying behavioral effects are also provided.     

Decreased plasma fibronectin in neonatal sepsis

Fibronectin is a large opsonic glycoprotein which promotes reticuloendothelial system clearance of bacteria, immune complexes, collagenous debris, and damaged platelets. The concentration of plasma fibronectin is decreased in the newborn infant; however, the role of fibronectin in the onset and course of neonatal sepsis is unknown. Serial plasma fibronectin levels were determined in 19 neonates with documented bacterial sepsis. Plasma fibronectin concentrations decreased significantly (P less than .001) in all study infants concurrent with the development of septicemia. Recovery of plasma fibronectin to normal levels occurred by day 5 in premature neonates and by days 7 to 10 in term neonates. Fibronectin deficiency and resultant reticuloendothelial system impairment may decrease the ability of newborn infants to resist or clear bacterial infections. An acute reduction in the concentration of plasma fibronectin may be a valuable marker for neonatal sepsis.     

Decreased protein binding of salicylates in Kawasaki disease

Because patients with Kawasaki disease have low serum concentrations of salicylates despite high doses, and because the free (unbound) drug is responsible for the pharmacologic effects of salicylates, we assessed salicylate protein binding in patients with Kawasaki disease. During the acute phase of the disease, protein binding of salicylate in 36 children with Kawasaki disease was 73 +/- 12%, significantly lower than during the subacute phase (90.4 +/- 8.7%; p less than 0.0005). Mean serum albumin concentration was 29.2 +/- 6.4 gm/L during the acute phase and 36.7 +/- 7.8 gm/L during the subsequent subacute phase (p less than 0.005). Salicylate protein binding was affected independently by both serum albumin and total salicylate levels. During the acute phase of Kawasaki disease, children had an average twofold increase in free salicylate compared with normoalbuminemic control subjects. A nomogram has been devised to derive free salicylate levels from the known total salicylate and serum albumin concentrations.     

新生儿坏死性小肠结肠炎血浆肠脂肪酸结合蛋白水平变化的意义

目的 探讨血浆肠脂肪酸结合蛋白（I-FABP）水平变化在指导新生儿坏死性小肠结肠炎（NEC）诊断及治疗中的意义.方法 选择2011年5月至2012年12月我院新生儿科收治的患儿,按入院先后顺序,以明确诊断NEC的50例新生儿为NEC组,其中NECⅡ期30例,NECⅢ期20例,以非NEC新生儿50例为对照组.NEC组在确诊后24 h内、对照组在相应日龄取血,采用酶联免疫吸附法（ELISA）检测血浆I-FABP水平,根据NEC患儿病情转归分为存活组及病死组,按治疗方法分为保守治疗组和手术治疗组,比较不同组间血浆I-FABP水平、新生儿危重病例评分（NCIS）分值、脓毒症的发生率及病死率.结果 NECⅡ期组、NECⅢ期组和对照组血浆I-FABP水平分别为（95.6±18.5） μmol/L、（151.2±10.8）μmol/L和（1.2±2.3）μmol/L,组间比较差异有统计学意义（P＜0.05）;NECⅡ期组和NECⅢ期组NCIS评分明显低于对照组,脓毒症发生率和病死率均高于对照组,差异有统计学意义（P＜0.05）,NECⅡ期组和NECⅢ期组差异无统计学意义（P＞0.05）.病死组血浆I-FABP水平、脓毒症发生率高于存活组,NCIS评分低于存活组;保守治疗组I-FABP水平低于手术治疗组,NCIS评分高于手术治疗组,差异均有统计学意义（P＜0.05）.结论 血浆I-FABP水平可较敏感地反映NEC患儿的病情变化,可作为预测NEC病情严重程度及指导采取内外科治疗的指标之一.     

Urinary uric acid in preterm neonates

Objective  

Study of uric acid level in spot urine of normal preterm AGA (appropriate for gestational age) babies in day one of their life.     

Acarboxy prothrombin in cord plasma from normal neonates

Acarboxy prothrombin was detected in the plasma of 48 of 128 umbilical cord plasma samples and in all of 65 patients receiving coumadin. None was found in 20 normal adults. Although the prevalence was the same in blacks, whites, and neonates of mixed origin, levels were significantly higher in blacks. There was a negative correlation between the level of acarboxy prothrombin and the prothrombin index. There was no correlation between maternal age, birth weight, gestational age, obstetrical complications, race, socioeconomic status, albumen, or alpha-foetoprotein and the incidence of cord plasma acarboxy prothrombin.     

Decreased adherence, chemotaxis and phagocytic activities of neutrophils from preterm neonates

Using microanalytic assays various phagocytic functions of separated neutrophils from preterm neonates (mean birthweight 1,506 g, n = 13) were simultaneously studied. Adherence of neutrophils to nylon fibre was decreased in cells from preterm infants (77.1 +/- 3.1%) when compared with adult controls (86.9 +/- 2.1%, mean +/- 1 SD, p less than 0.05). In addition neutrophil chemotaxis in response to zymosan activated serum was reduced in preterm neonates (131.9 +/- 19.7, adults 166.6 +/- 11.1, p less than 0.001); directed migration towards Formyl-Methionyl-Leucyl-Phenylalanine was also decreased (preterm neonates 93.4 +/- 15, adults 111.1 +/- 16.8, p less than 0.05). Preterm infants had a higher percentage of slow moving neutrophils when compared with adults (p less than 0.001). Phagocytosis of Candida albicans was reduced in neutrophils from preterm neonates (phagocytic index: preterm neonates 41.4 +/- 12.7, adults 83 +/- 7.2). Adult neutrophils ingested more Candida per cell (p less than 0.001). Chemiluminescence, exocytosis of elastase and lactoferrin during uptake of opsonized zymosan was also reduced in neutrophils from preterm neonates. However, random migration, phagocytosis of Staphylococcus aureus and production of O2- in response to Phorbol myristate acetate or opsonized zymosan were identical in cells from either source. We conclude, that these abnormalities of neutrophils could predispose the preterm infant to serious and often overwhelming bacterial and fungal infections.