Objective To distinguish primary CMV infection from reactivation or reinfection. Methods A urea denaturation test was included in the washstep of the standard IgG ELISA in 12 patients of age＜12 whose serum CMV-IgG were positive, avidity indexes of CMV-IgG were measured. Results Among children aged 1～12 years, the varieties of avidity indexes of CMV-IgG in A group(IgM negative and IgG positive) and B group(IgM positive and IgG positive) had the same trend. There was only one case in B group whose avidity index was under 30%, the other were all above 30%, and most were above 50%. But among 40 children aged 1～12 months,the avidity indexes were under 30% in 21 cases,8 cases were 30～50% ,and 11 cases were above 50%. The antibody avidity in 1～6 months children was influenced by their mothers lgG,80% (12/15) of 7 ～12 months children had low-avidity antibodies. Conclusion CMV infection mostly occurred among 1～12 months children. Urea denaturation test was an efficient method to distinguish primary CMV infection from reactivation or reinfection.

Objective To study the clinical evaluation of gas exchange impairment in neonatal respiratory failure.Methods Blood gas, PaO2/PAO2, Qs/QT, PaO2/FiO2, A-aDO2 and RI of 53 newborn infants with respiratory failure in NICU of PUMCH from Jan. 1993 to Dec. 1997 were measured. Results These infants were divided into two groups according to PaO2/PAO2: moderate and severe respiratory failure. Qs/QT(11±3)%, PaO2/FiO2(183±113), A-aDO2(22.9±6.8)kPa, RI(2.5 ±0.8) in 21 neonates with moderate respiratory failure; Qs/QT(24±6)%, PaO2/FiO2 (82±30), A-aDO2 (49.3 ± 17.8)kPa,RI(7.6 ±3.4) in 32 neonates with severe respiratory failure(P＜0.001). These results in respiratory failure caused by different pathogenesis were different. In meconium aspiration and pneumothorax group there were the highestQs/QT(32±3)% ,A-aDO2 (69.8 ± 12.2)kPa,RI(9.2 ±2.9)and the lowest PaO2/FiO2 (77±39). Mortality of infants with high pulmonary shunt was high. Qs/QT(17±8)% in 38 survives and (24±6)% in 10 died neonates( P＜0.05). Conclusion The clinical evaluation using these indexes for newborn infants with respiratory failure is beneficial in recognizing pathogenesis,guiding therapy and evaluating prognosis.

Objective To investigate the incidence of fetal malnutrition( FM), its affected factors and their relationship with small - for gestational - age (SGA) fetus. Methods The intrauterinal growth of fetus was evaluated by the body weight of neonates and FM was detected by clinical assessment of nutritional status ( CANS ). Results ①33 out of 204 cases were found to be FM (16% ). FM in SGA group was significantly higher than that in AGA group ( 5.9% ) (x2 = 69.9, P ＜ 0. 01 ).② When ot = 0. 05, the body weight and head circumference of neonates, the education level of mothers were included into logistic regression model, and their regression coefficient were negative. Conclusion SGA was supposed to be two of the risk factors in developing FM. Fetus with low body weight, small head circumference and not - so - well educated mother were prone to suffer from FM.

Fatty acid oxidation disorders(FAOD)include more than 10 kinds of diseases,they all belong to autosomal recessive diseases and are common inherited metabolic diseases. Onset age of the patients with FAOD are from newborn to adult. The clinical manifestations were nonspecific,mainly manifested as liver disease,cardiomyopathy and muscle diseases. Detection of free carnitine and acylcarnitines in blood by tandem mass spectrometry and detection of gene mutations are important methods for diagnosis of such diseases. Tandem mass screening for neonatal screening is helpful for early diagnosis and early treatment of FAOD. Primary carnitine deficiency and multiple acyl-CoA dehydrogenase deficiency can be treated by specific therapeutic drugs with good effect. There are no specific drugs for other diseases,which need symptomatic treatment.

()of recessive hereditary diseases caused by the dysfunction of enzymes required for fatty acids to enter mitochondria or fatty acid beta-oxidation,including carnitine transport disorders and fatty acid beta-oxidation disorders. Clinical symptoms are non-specific,involving multiple organs,such as liver,myocardium,skeletal muscle,brain and kidney. Most FAOD patients diagnosed by newborn screening have no clinical symptoms or mild symptoms through early intervention management,but they are prone to acute onset or even sudden death under stress conditions such as hunger and exercise. Long-term follow-up and management can effectively reduce the mortality and morbidity rate of FAOD.

Primary carnitine deficiency is an autosomal recessive hereditary disease caused by the mutation of SLC22 A5 gene,which leads to increased carnitine excretion in urine and low level of carnitine in blood,tissues and cells. Due to the heterogeneity and non-specificity of the clinical manifestations of PCD,it is easy to be misdiagnosed or missed and it is potentially fatal without timely treatment. This disease can be detected early through the newborn screening. Maternal carnitine deficiency and the secondary carnitine deficiency caused by other diseases should be excluded. Genetic test can give a clear diagnosis. Avoiding hunger and use of oral L-carnitine supplementation to maintain normal plasma carnitine concentrations are effective treatments.

Multiple acyl-CoA dehydrogenase deficiency,also known as glutaric aciduria typeⅡ,is an autosomal recessive inherited metabolic disease. It is a mitochondrial electron transport chain and fatty acid metabolism disorder caused by a defect of electron transfer flavoprotein(ETF)or ETF dehydrogenase(ETFDH),resulting in the damage to multiple organs such as myocardia,liver,brain and skeletal muscle. The clinical diagnosis of multiple acyl-CoA dehydrogenase deficiency is difficult due to the lack of specific symptoms and signs of the patients. To make a definitive diagnosis,blood aminoacids and acylcarnitine profiles,urinary organic acids profiles and gene analysis are necessary. According to the response to ribo-flavin(or vitamin B2),multiple acyl-CoA dehydrogenase deficiency could be divided into riboflavin-responsive form and riboflavin-unresponsive form. The riboflavin-responsive form is usually observed in the late-onset cases with good outcome.The patients of riboflavin-unresponsive form usually have early-onset with severe diseases. Bezafibrate, L-carnitine,coenzyme Q10,sodium-D,L-3-hydroxybutyrate and low-fat die should be considered for the treatment. Some patients with riboflavin-unresponsive form show poor outcome.

Medium chain acyl CoA dehydrogenase deficiency is a mitochondrial fatty acid oxidative deficiency disease. It has various clinical manifestations,such as hypoglycemia,lethargy,myasthenia,etc. Different clinical manifestations and atypical biochemical examination can increase the difficulty of diagnosis,which is more likely to result in misdiagnosis. If it is not treated in time,mortality and the rate of sequelae are high,but if confirmed by neonatal screening and treated in time,satisfactory results can be obtained.

Very long chain acyl-CoA dehydrogenase deficiency(VLCADD)is a disorder involving the initial step of fatty acid beta-oxidation in the mitochondrial matrix. VLCADD can present at various ages,from the neonatal period to adulthood,with symptoms including hypoglycemia,rhabdomyolysis,skeletal muscle weakness and cardiomyopathy,and poses the greatest risk of complications during intercurrent illness or after prolonged fasting. Early diagnosis,treatment,and surveillance can reduce mortality. The most common diagnostic evaluation methods are plasma acylcarnitine profiles and ACADVL gene molecular testing. Functional testing,including white blood cell or fibroblast enzyme assay,is a useful diagnostic adjunct if molecular sequencing alone is insufficient to deter-mine the diagnosis or uncharacterized mutations are identified. Treatment emphasizes the avoidance of fasting and often includes a specialized diet that is high carbohydrate/low longchain fat which is supplemented by medium chain triglycerides(MCT).very-long chain acyl coenzyme A dehydrogenase

myocardium. Fatty acid oxidation disorders(FAODs)can give rise to insufficiency of mitochondrial energy production and accumulation of metabolic intermediates in cardiomyocytes,such as lipid and long-chain acyl carnitine,leading to myocardial lesions.FAODs include carnitine-dependent fatty acid transport disorders and mitochondrial fatty acid beta-oxidation disorders,with any enzyme or transporter defect in fatty acid oxidation process resulting in this disease. Although FAODs are one of the rare causes of pediatric cardiomyopathy,some patients with FAODs are expected to have cardiomyopathy alleviated and quality of life improved by early correction of fatty acid metabolic disorders.