While only in minute quantities in the body, trace elements are crucial co-factors and regulators of normal metabolism.Commonly tested elements include calcium, magnesium, iron, zinc, and copper.Imbalance or deficiencies in trace elements can cause growth retardation, malnutrition, immune malfunction and other abnormalities in children.Because these elements are in trace amounts, sensitivity and reproducibility of detection methods are of paramount importance.Different methods for the same element can yield different reference intervals, which, in order to be applied in the clinic, would have to be independently established by individual laboratories.Clearly defined indications and good quality control to ensure accuracy and sensitivity are necessary for the measurement of trace elements to provide objective reference for clinical diagnosis.

As a new emerging infectious virus, 2019 novel coronavirus (2019-nCoV) has been widely popular all over the world since the beginning of 2020. As a special group, children have similarities and differences with adults for coronavirus disease 2019 (COVID-19) in the epidemiology, diagnosis and treatment, curative effect monitoring, prognosis, virus testing methodology, infection and inflammation markers, etc. This paper mainly reviews the characteristics of COVID-19 in children from two aspects: the epidemiological and pathogenic detection characteristics, so as to provide some basis for its diagnosis and treatment.

Objective To investigate the effects and safety of human hepatocytes transplantation in vivo for the treatment of liver failure. Methods The primary human hepatocytes were collected from normal liver tissue donated by healthy volunteers and preserved by cryopreservation technique. After thawing, the hepatocytes were transplanted into the spleen of patients with severe hepatitis through catheterization of the femoral artery. Then the changes in clinical symptoms, serum biochemical indexes and MRI signals of the spleen were observed in the patients. Results A total of 2?10 10 hepatocytes were isolated from normal liver tissue of healthy volunteers and 75% of the hepatocytes were alive after cryopreservation and thawing. The number of transplanted hepatocytes was 2?109. In the recipients, the clinical symptoms were markedly improved, serum levels of bilirubin, NH_3, ALT and AST were significantly reduced, but that of PTA remarkably increased, after hepatocyte transplantation. The follow-up examination was performed 80d and 270d after discharge from the hospital, and it was showed that all the serum biochemical indexes returned to normal and signals of the hepatocytes were found in the spleen. Conclusions Hepatocyte transplantation is a safe and effective therapy for severe hepatitis. The transplanted hepatocytes can proliferate and differentiate in the spleen to replace or partially compensate the liver function of synthesis, detoxication and metabolism. Contrast enhanced MRI can be a new method for follow-up study of transplanted hepatocytes.

Objectives To evaluate the efficacy and safety of h um an hepatocyte transplantation in the treatment of severe hepatitis induced by dr ugs. Methods The primary human hepatocytes were isolated from t he liver of a healthy donor, and they were then cryopreserved. The thawed hepato cytes were transplanted into the patient's spleen via a femoral artery catheter. 2?10~10 hepatocytes were harvested, and 70% of thawed hepatocytes were vi able, and 2?10~9 vital hepatocytes were transplanted. Results One month after the transplantation, clinical symptoms of the recipient were a meliorated obviously, and the levels of BIL, NH3, ALT and AST lowered, while PA elevated. 50 days after discharge from the hospital it was found that biochemica l parameters returned to normal values, and the hepatocyte signal could be detec ted in the spleen with MRI. Conclusion Hepatocyte transplantati on is safe and efficacious.

Objective:To analyze gene mutations in 3 families with self-improving collodion ichthyosis.Methods:Clinical data were collected from 3 patients with self-improving collodion ichthyosis. DNA was extracted from the peripheral blood of patients and their parents, and high-throughput sequencing was performed in the patients by using a multi-gene panel targeting congenital ichthyosis. After identification of causative gene loci, Sanger sequencing was performed to bidirectionally verify the mutations in the patients and their parents.Results:All the 3 patients presented with a collodion-like membrane at birth, which was shed within 2-4 weeks after birth, and then they gradually showed similar features of mild ichthyosis, including dry skin, tiny scales at local sites, flexural involvement, mild sweating, heat intolerance, cheek flushing, mild palmoplantar keratosis or palmar hyperlinearity. Compound heterozygous mutations were identified in the ALOX12B gene of the 3 patients, including a paternal mutation c.406_408delGAG and a maternal mutation c.77T>C in case 1, a paternal mutation c.1013C>T and a maternal mutation c.1286C>G in case 2, a paternal mutation c.1232T>C and a maternal mutation c.1440C>A in case 3. Function prediction analysis showed that 4 missense mutations c.77T>C, c.1286C>G, c.1013C>T, c.1232T>C and 1 deletion mutation c.406_408delGAG may exert pathogenic effect, and 1 nonsense mutation c.1440C>A led to the generation of a termination codon encoding a truncated protein p.Tyr480Ter, which may affect the protein function and cause disease. None of the 6 mutation sites had been reported in the past.Conclusion:Compound heterozygous pathogenic mutations were identified in the ALOX12B gene of the 3 patients with self-improving collodion ichthyosis, which were inherited from their parents.

Objective To investigate the role of AP-1 in the pathogenesis of chronic idiopathic urticaria (CIU). Methods By using immunomagnetic separation technology, peripheral blood basophils were isolated from 10 CIU patients and 10 normal human controls followed by the extraction of nuclear protein from the basophils. TransAMTM AP-1 family kit was used to detect the DNA binding activity changes of AP-1 family transcription factors in basophils, and Western blotting to detect the expression of P-c-jun protein. Results There were some differences in the DNA binding activity of AP-1 family transcription factors in basophils between CIU patients and normal controls. The DNA binding activity of Phospho-c-jun, c-fos, Fos-B, Jun-B and Jun-D factors was increased in CIU patients compared with the controls, and the increase in that of P-c-jun and Jun-D was statistically significant (both P < 0.05). There was an insignificant decrease in the DNA binding activity of Fra-1 factor in the CIU patients compared with the controls (P > 0.05). The P-c-jun (Ser73) protein expression was higher in CIU patients than that in the controls (0.527 ± 0.312 vs. 0.435 ± 0.042, P < 0.05),whereas there was no significant difference in the P-c-jun (Ser63) protein expression level. Conclusion Some changes in DNA binding activity of AP-1 and overexpression of P-c-jun (Ser73) protein in basophils may be involved in the pathogenesis of CIU.

Objective To investigate the vascular compliance markers (C1 and C2) and pulse wave velocity in relative with other physiological indexes in a cohort of young normotensive people in Beijing. Methods Two hundred and seventy normotensive volunteers (112 men and 158 women aged 16 to 30 years) were invovled,completed questionnaires of demographic information. Large (C1) and small (C2) arterial compliance were derived from arterial pulse wave contour analysis. Pulse wave velocity(carotid-femoral PWV and carotid-radial PWV)was determined by Complior SP. Results In both male and female C1 correlated positively with height and weight,and negatively with systolic(SBP),mean arterial blood pressure(MAP),pulse pressure(PP),and heart rate(HR),in which PP showed the best correlation with C1;C2 was inversely related with SBP,diastolic blood pressure(DBP),MAP and HR,in which SBP showed the best correlation with C2;cfPWV correlated positively with DBP and age,crPWV correlated positively with age,DBP,height and weight. Conclusion Blood pressure,heart rate were the important influential factors of large and small arterial compliance in both males and females,while diastolic blood pressure was determinant for pulse wave velocity.

Objective To explore the molecular characteristics of community-associated Methicillin-resistant Staphylococcus aureus (CA-MRSA) from children with skin and soft tissue infection (SSTIs) in China.Methods CA-MRSA was collected from the outpatients in Department of Dermatology in 13 Children's Hospitals of China.Genotypic characteristics of CA-MRSA isolates were tested by adopting mnltilocus sequence typing (MLST),staphylococcal protein A (spa) typing and Staphyloccoccal cassette chromosome mec (SCCmec) typing.And the presence of Panton-Valentine leukocidin genes(pvl) was determined also.Results Overall,1 705 strains of Staphylococcus aureus were isolated from SSTIs children,and CA-MRSA accounted for 2.6％ (44/1 705 strains).Two types of SCCmec were detected in all the CA-MRSA strains,and the main types were SCCmec Ⅳ and SCCmec Ⅴ,accounting for 45.5 ％ (20/44 strains) and 54.5 ％ (24/44 strains),respectively.Thirteen MLST types (STs) and 15 spa types were detected among CA-MRSA.The most prevalent MLST was ST121 (18/44 strains,40.9％),followed by ST59 (9/44 strains,20.5％).Additionally,t437 was predominant,accounting for 40.9％ (18/44 strains).ST121 strain had 8 spa types,and t2086 was the most common type (6/18 strains,33.3％);while ST59 had only 1 spa type,t437.No ST121,ST59 and t437 strains were found in Central and Eastern region of China.Only 4 (9.1％) of the 44 CA-MRSA strains harbored pvl genes which were all from Southern region.Conclusions The most common clone of SSTIs CA-MRSA in children is MRSA-ST121-SCCmec Ⅳ/Ⅴ,as the molecular epidemiology of CA-MRSA strain has changed,ST121 has replaced ST59 to become the main epidemic strains.

Objective To explore the treatment of hemangioma associated with thrombopenia(Kasabach-Merritte syndrome,KMS) in infant.Methods The clinical manifestation and the therapy of 14 cases patients with KMS in hospital from 2003 to 2006 were collected ang analyzed,the 400 g/L urea(manufactured by ourself)combined with methylprednisolone local injection were used and followed 0.5 to 1.0 year.Results Two in 14 cases were emergency exairesis,7 cases were recurred for several times,12 cases were cured,1 case was improved,1 case was loss the connection.Conclusions It is an ideal therapy method to use the urea combined with glucocorticoid to treat infancy KMS,little trauma,definite effective,low side effect,high cure rate.

Objective To investigate the clinical value of the combination of routine magnetic resonance imaging (MRI),magnetic resonance cholangiopancreatography (MRCP),diffusion weighted imaging (DWI)and enhanced magnetic resonance imaging in the diagnosis of recurrent pyogenic cholangitis (RPC).Methods The clinical and MRI data of 2 1 cases of RPC confirmed by surgery or puncture were retrospectivly analyized.Results All of 2 1 patients were performded with routine MRI (FSE T2 WI,FSPGR T1 WI and FIASTA),MRCP and DWI.1 2 cases were underwent three-dimensional dynamic contrast-enhanced MRI with a liver volume accelerated acquisition sequence (LAVA).The raw data was uploaded to GE ADW4.4 station and the three dimensional MRCP and DWI were analyzed.(1)All of 21 cases were hepatolithiasis complicated with irregular expansion.11 cases were involved left intra-hepatic bile duct,7 cases were right intrahepatic duct,and 3 cases were involved left and right intrahepatic bile duct.Wall thickening was in 19 cases,normal biliary duct wall was in 2 cases.(2)Common bile duct disease:calculus of intrahepatic and extrahepatic bile duct complicated with bile duct dilatation were in 8 cases.Calculus of intrahepatic bile duct were individually in 13 cases.(3)Gall-bladder disease:there were 5 cases of gallstone,9 cases of chronic cholecystitis,3 cases of acute cholecystitis and 4 cases of chole-cystectomy.(4)Liver parenchyma disease:there were 6 cases of liver atrophy in all the cases (left lobe atrophy of 4 cases,right lobe atrophy of 4 cases).The inflammatory changes around dilated bile ducts were found in 1 2 cases.The MRI findings of those were slight patchy hyperintensity signal on conventional T2 WI,the area of hyperintensity signal on T2 WI was extended on DWI.On dynamic contrast-enhanced MRI,the inflammatory areas were uniformity minor enhancement on arterial phase,and hardening in-creases on portal and delayed phase.Conclusion Multi-sequences MRI can be more fully reflected the pathologic changes of RPC, which is important for imaging diagnosis of the disease.