新生儿成熟度和产后日龄对血清钾水平的影响

目的　探讨新生儿成熟度和产后日龄对血清钾浓度的影响。方法　回顾性分析了胎龄为 2 4～ 2 8周 (A组 ) ,2 9～ 3 2周 (B组 ) ,3 3～ 3 6周 (C组 )和 3 7～ 4 2周 (D组 )新生儿生后 1～ 72h内的血清钾水平及其变化。结果　①新生儿的胎龄、体重和尿量与血清钾水平存在着线性关系。②生后 1～ 2 4h ,A组新生儿的血清钾水平最高 ,B组次之 ,C和D组相当 ,为最低。生后 4 8h内 ,A和B组的血清钾水平开始下降 ,并于 72h内下降至C和D组新生儿水平。C和D组新生儿生后 72h内的血清钾水平无明显变化。③A ,B和C组早产儿生后 2 4h内高钾血症 (≥7.0mmol/L)发生率分别为 2 0 .0 % ,12 .5%和 4 .0 % ;2 4例高钾血症患儿经常规治疗后 ,14例 (58.3 % )于 72h内血钾降至 7.0mmol/L以下并存活 ;10例 (4 1.7% )高钾血症状态持续存在 ,其中 7例死亡。D组足月儿于生后 72h内未出现高钾血症。结论　新生儿的成熟度和产后胎龄影响血清钾水平 ;极不成熟新生儿 (2 4～ 3 2周 )在生后 2 4h内具有较高的血清钾水平 ,继之随生后日龄的增加而降低 ;早产儿可有致命性高钾血症存在 ,常规治疗仅部分有效。     

Steady state serum digoxin concentration in relation to digitalis toxicity in neonates and infants

Steady state serum digoxin concentrations were determined in 34 neonates and infants receiving standard maintenance doses of the drug. Digitalis intoxication, diagnosed by ECG criteria, occurred in four of 13 patients with a serum concentration above 2 ng/ml and not in any of 21 subjects with a serum digoxin concentration below this level. This association was found to be significant. It seems that the concept of increased tolerance to digoxin hitherto ascribed to infants is not tenable and that the monitoring of serum digoxin concentration is essential to treatment in this age group.     

Serum retinol-binding protein and vitamin A levels in malnourished children.

Serum levels of vitamin A and retinol-binding protein (RBP) were measured in children with vitamin A deficiency, in children with protein-energy malnutrition (PEM) and in normal children, before and after administration of 100 000 IU of water-miscible vitamin A. Serum vitamin A and RBP levels were significantly low in children with vitamin A deficiency and in children with severe PEM, whereas the values in milder grades of PEM were similar to those of normal subjects. In severely malnourished children with corneal lesions, serum vitamin A concentration was reduced to a much greater extent than the level of serum RBP. Administration of vitamin A resulted in a significant increase in serum levels of both the components within 4 hours in all the 3 groups of children. The increase in RBP concentration observed in children with PEM was similar to that in vitamin A deficient children. These results indicate that in malnourished children, particularly in those who are at risk of developing keratomalacia, vitamin A is the main limiting factor. It is, therefore, recommended that children with PEM should be treated with vitamin A in addition to dietary protein and calories.     

Age-dependent variation in the serum concentration of mannan-binding protein

Mannan-binding protein (MBP) is an acute phase reactant, and its deficiency is associated with the common opsonic defect and suspectibility to infections and atopic constitution. The aim of this study was to investigate the changes occurring in the serum level of MBP in infancy and during later childhood. We studied the serum concentration of MBP in 611 Finnish children of different ages and 110 adults by using an enzyme immunoassay. In an analysis of successive serum samples from infants at the day of birth and at the ages of 1 and 5 months, and at 1 and 2 years, the serum concentration of MBP increased significantly after birth, and was at its highest (the mean and median were 8.13 and 8.49 mg1⁻¹, respectively) at the age of 1 month. After that, it declined to the initial level until the age of 5 months. The MBP concentration continued to decrease during childhood, and after the age of 12 years the MBP values reached the adult level. In Finnish adults the mean and median concentrations of MBP were 4.48 and 4.02 mg 1⁻¹, respectively, which seem to be higher than those reported previously in other populations. The high concentration of MBP in infants may best be explained by exposure to novel environmental antigens in early childhood, which suggests a protective role for MBP during the period of immaturity of the immunosystem. In older children the high level of MBP can probably be explained by childhood infections and the ensuing need of MBP.     

胰岛素样生长因子1、视黄醇结合蛋白和前白蛋白作为新生儿营养指标的探讨

目的 探讨血清胰岛素样生长因子1（IGF－1）、视黄醇结合蛋白（RBP）和前白蛋白（PA）的水平变化对新生儿营养状况的评价。方法 采用放射免疫分析法检测80名新生儿脐血IGF－1水平；采用酶联免疫法检测其RBP和PA水平，并按小于胎龄儿（SGA）和适于胎龄儿（AGA）进行分组比较。结果 AGA组IGF－1和RBP明显高于SGA组（P＜0．05），AGA组PA显著高于SGA组（P＜0．01）。结论 新生儿脐血IGA－1、RBP和PA可成为反映因围生因素造成胎儿宫内营养不良的良好生化指标。     

Plasma concentration of granulocyte-colony-stimulating factor in neonates

We determined the plasma concentration of granulocyte-colony-stimulating factor (GCSF) and the neutrophil count in 108 infants (gestational age 23–41 weeks; birthweight 478–4935 g). The GCSF levels in the very low birthweight infants without infection were comparable to those in the full-term infants. Infants as premature as 23 weeks of gestation showed similar GCSF levels to mature neonates. GCSF levels decreased significantly by day 7 after birth. The levels were not significantly correlated with the neutrophil count. The mean plasma level of GCSF increased significantly when infection developed and was significantly higher in the infants with sepsis than in those with non-septic infections ( p < 0.01). The results suggest that GCSF may be the major determinant of neutrophil kinetics both during fetal life and after birth.     

Tolerance of mixed lipid emulsion in neonates: effect of concentration.

AIMS: To compare the effect of concentration of a mixed lipid emulsion (50:50 medium chain triglyceride/long chain triglyceride) (MCT/LCT) on lipid tolerance in neonates. METHODS: A prospective randomised controlled trial of 75 neonates requiring prolonged parenteral nutrition was conducted in the neonatal intensive care units of the Royal Maternity Hospital, Belfast, and the Waveney Hospital, Ballymena. Thirty eight infants received 10% and 37 20% lipid emulsion. Infants were randomly assigned to groups at the start of parenteral nutrition and studied if they required seven or more days of this. Lipid tolerance was assessed by twice weekly measurements of plasma triglyceride and cholesterol concentrations and weekly measurement of non-esterified fatty acids and beta hydroxy butyrate. Anthropometry was carried out weekly. RESULTS: The mean cholesterol in the 10% group was significantly higher within the first seven days of the study compared with the 20% group (3.5 vs 2.87 mmol/l), and continued to rise over the study period in contrast to the 20% group. A similar pattern was observed with the triglyceride concentrations. There was no significant difference in non-esterified fatty acids, beta hydroxy butyrate, or growth between the two groups. CONCLUSION: Sick neonates show better biochemical tolerance to 20% MCT/LCT emulsion than to 10% emulsion.     

Serum phosphate concentration. Effect on serum ionized calcium concentration in vitro

We examined the effects of variations of serum phosphate levels on serum ionized calcium concentrations in vitro. A single donor serum sample was divided into 25 aliquots stored in tubes sealed with carbon dioxide and divided into 5 subsets of tubes. The pH was altered in 4 of the 5 subsets by adding various concentrations of hydrochloric acid or sodium hydroxide. The pH levels studied ranged from 7.09 to 7.63. The phosphate concentration was altered in each subset by adding various concentrations of a phosphate buffer. The phosphate concentrations studied ranged between 0.81 and 3.58 mmol/L. There was an inverse relationship between ionized calcium and phosphate at all pH levels studied. The ionized calcium concentration correlated inversely with pH. We suggest that in addition to factors well known to influence serum ionized calcium concentration (such as protein, bicarbonate, and pH values), serum phosphate concentration also plays an important role.     

A detailed analysis of changes in serum C-reactive protein levels in neonates treated for bacterial infection

A prospective study was undertaken to characterize the rate of increase, time of peak values and rates of decrease in serum concentrations of C-reactive protein (CRP) in a group of infants treated for neonatal bacterial infection. A total of 176 consecutively admitted neonates with birth weight >1500 g and without mechanical ventilation or central lines in situ, who received antibiotic therapy for suspected bacterial infection, were enrolled. The changes in serum CRP concentration in 60 of 63 infants who had CRP values above 20 mg/l 24–48 h after the beginning of treatment were analysed in detail. Initial increase rates in serum CRP levels of up to 4.5 mg/l per h were documented peak were reached at a mean of 19.5 h after antibiotic therapy had been initiated, but in some patients an increase in serum CRP levels occurred up to 40–48 h after the beginning of treatment. The mean serum half-life of CRP in infected neonates was 21 h (range 11.2–38 h). Conclusion In neonates with bacterial infection (defined by a combination of clinical signs and increased C-reactive protein and immature-total quotient values) no differences in the overall pattern nor in any of the particular phases of the C-reactive protein response curves could be observed between neonates with positive (n = 13) or negative blood cultures (n = 47). Received: 18 July 1997 / Accepted in revised form: 5 May 1998     

Higher serum eosinophil cationic protein levels in children with cow's milk allergy

BACKGROUND: In the pathogenesis of cow's milk allergy, abnormal immunologically mediated reactions play a basic role. Eosinophil activation also participates in the development of several allergies. The purpose of this study was to characterize the degree of this activation by measuring the serum level of eosinophil cationic protein (sECP) and establishing whether it is a useful parameter in monitoring oral cow's milk allergy. METHODS: The sECP level of 35 patients with previously confirmed cow's milk allergy (mean age, 16 months) was evaluated using a fluoroimmunoassay before the cow's milk rechallenge test and at 2 hours and 24 hours after cow's milk challenge. RESULTS: Of the 35 children with previously confirmed cow's milk allergy, 10 had positive clinical reactions after the milk rechallenge test, whereas 25 children had no reaction. The median sECP level of all the patients before the challenge test was significantly higher (12.4 microg/L) than that of the control group (4.3 microg/L) (P < 0.05). Two hours after the challenge, the median sECP of all patients (9.4 microg/L) was lower than the starting values. The median sECP levels were higher in children with positive challenge test results at all time points. However, this difference was not statistically significant. CONCLUSIONS: The normalization of sECP level may indicate the cessation of the cow's milk allergy. Therefore, the measurement of sECP may be helpful in determining the optimal time in which to repeat the challenge test, when the result will more likely be negative. The significant decrease of the sECP level 2 hours after the beginning of milk challenge test may be explained by the fact that this protein is excreted into the intestinal lumen.     

Serum retinol and retinol-binding protein in mothers and infants at delivery

The relations at birth between infant and maternal serum retinol, retinol-binding protein (RBP) and retinol/RBP molar ratio were investigated in 25 healthy term infants and their mothers. The mean serum levels of retinol and RBP were significantly higher in the mothers, but the mean molar ratio of retinol/RBP (RBP saturation) was significantly higher in the infants. Both the infant serum RBP and the infant RBP saturation were positively correlated to the respective serum levels in the mothers.     

Intussusception in neonates: analysis of 14 Japanese patients

OBJECTIVE: To clarify the clinical features and pathogenesis of intussusception in neonates. METHODS: Fourteen neonates were diagnosed with intussusception between June 1974 and January 2001. Patients were divided into two groups according to whether or not signs were present on the first day of life. The clinical features were interrelated with the pathological findings. RESULTS: All six patients in the group whose signs were present on the first day of life also had intestinal atresia or malrotation. Among patients whose signs began less than 24 h after birth, five of eight patients suffered hypoxia. Moreover, it was very difficult to establish the diagnosis of intussusception, particularly in the group of late-onset type intussusception. CONCLUSIONS: Hypoxic events may play a crucial aetiologic role in the pathogenesis of late-onset neonatal intussusception.