A chemical method to prepare biotin-labeled nucleic acid probe for nonisotopic hybridization is introduced. The method involves the bisulfite-catalyzed transamination reaction of cytosine residues in nucleic acids with ethylenediamine or hexanediamine. Primary amino groups on the cytosine derivatives are then reacted with biotiny-N-hydroxysuccinimide ester. Results of dot blot and Southern blot carried out with biotinlabeled ? DNA probe show that such nonisotopic probe method is sensitive, specific, repeatable and unexpensive.

The conditions for denaturation of DNA and RNA were invertigated. The results show that one minute to heat DNA at 100鈩?is sufficient for denaturation of DNA (several hundreds bp to 23kb). DNA degraded more obviously with longer neating time and the degradation decreased when DNA was dissdved in TE buffer. But no difference of degree of RNA degradation was found in there three conditions for RNA denaturation.

Human IL-6,IL-10,IL-13 and SCF cDNAs encoding extra - cellular domain were isolated by reverse transcription polymerase reaction (RT-PCR). These cDNA fragments were inserted into expression vector PBV220 which contains PRP_(L), promoters and SD sequence. Then the E. coli DH5? were tronsformed with the recombinant plasmids. After screening, the clones carrying those recombinant plasmids were identified. SDS-PAEG and biological assay indicated that human IL-6, IL-10 and IL-13 were expressed in E.coli. The expression level of rhIL-6 was as high as 30% of the total bacterial protein.

Objective To analyze the clinical and imaging features of 2 siblings with leukoencephalopathy due to NADH dehydrogenase (ubiquinone)flavoprotein 2 (NDUFV2) gene mutation,in order to better understand and diagnose it earlier.Methods Clinical and follow-up data of the proband and his brother were collected.Clinical features including symptoms,signs and cranial magnetic resonance imaging (MRI) were analyzed,and 2 patients were followed up for a long time.Sanger sequencing,targeted next generation sequencing,and whole exome sequencing were performed to identify potential genetic variations in the 2 patients and their parents.Results (1) Clinical characteristics and follow-up:ages of onset were 4 months and 1 year respectively.Both of the patients presented rapid motor regression hyperinyotonia,positive pathological character.During the follow-up the condition became stable,motor function and cognition improved gradually after cocktail therapy.(2) Brain MRI of the 2 patients showed prominent abnormalities in deep cerebral white matter,presenting T1 hypointense,T2 and fluid attenuated inversion recovery (FLAIR) hyperintense in the periventricular area.FLAIR images revealed that the abnormal white matter was partially rarefied and cavitated.Diffusion weighted images (DWI) showed high signals along the periphery of the involved areas.The follow-up MRI showed the cavitation still existed and even expanded,and DWI showed regional linear or spotty high signals around the original lesions.(3) Novel mutations in NDUFV2 gene,c.467T>A and c.404G>C,were identified in proband and his brother.The former inherited from his father,while the latter inherited from his mother,which was the new mutation not reported in the international.Conclusions The clinical features of the brothers presented subacute leukoencephalopathy with relatively stable or improved outcome.This was distinctive from the phenotypic features reported in 12 cases with hypertrophic cardiomyopathy or Leigh syndrome.The finding expanded the phenotypic spectrum of NDUFV2 mutations.Pathogenic gene of these patients which is the basis of genetic counseling for this family was determined.

Henoch-Schonlein purpura (HSP) is one of the most common clinical manifestations of systemic small vasculitis in children with non-thrombocytopenic, and mainly manifested as skin purpura, arthritis, gastrointestinal symptoms and Henoch-Schonlein purpura nephritis (HSPN). The severity of renal involvement is the main factor determining the long-term prognosis of children with HSP.Studies have revealed that the determination of pentraxin 3 (PTX3) in serum can be used for early diagnosis of HSPN and prediction of renal injury.In this paper, the origin, gene and protein structure, function, potential relationship and mechanism of action between PTX3 and HSP were discussed, so as to provide new ideas for the early diagnosis and treatment of HSPN.

Objective To analyze the clinical and imaging characteristics of congenital sensorineural hearing loss (CSNHL)children combined with white matter (WM)lesions in order to provide evidence for clinical practice. Methods With referral to the Department of Pediatrics,Peking University First Hospital from November 201 1 to De-cember 201 5,documents of 78 patients of CSNHL combined with WMlesions were collected and analyzed for the clini-cal and imaging characteristics.Results Bilateral severe -profound hearing loss existed in all 78 cases,48.1 %(25 /52 cases)of the patients exhibited gross motor development delay,98.1 %(51 /52 cases)of them had normal cognition development.One hundred percent (61 /61 cases)of patients had abnormal language development.Infection occurring during pregnancy existed in 21 .2%(1 1 /52 cases)of the patients,the premature and smaller for the gestational age in-fants accounted for 28.9% (1 5 /52 cases).The bilateral multiple WMlesions from the brain MRI were in dot to flake sizes with sharp boundary,the intensity of T1 -weighted imaging decreased,T2 -weighted imaging and fluid attenuated inversion recovery increased.Eighty -two point one percent (64 /78 cases)of the patients were found to have the periventricular and subcortical WM involvement.The most frequently affected periventricular region was the posterior horn (91 .9%,68 /74 cases),followed by the anterior horn and temporal horn,and the least with the body involvement. The former three had a combined lesion tendency (55.4% -68.9%).There was an extensive involvement in the sub-cortical WMof parietal,frontal,temporal and occipital lobes respectively(73.5% -88.2%).Subcortical WM involve-ment of multiple lobes was common (accounted for 67.6% -77.9%).The enlargement of bilateral ventricles existed in 37.2%(29 /78 cases)of the patients and cystic changes in the subcortical WM of anterior temporal lobe could be found in 9.0% (7 /78 cases)patients.Calcification in 2 CT cases was reported.Corpus callosum and basal ganglia of all cases were normal.For cases with MRI scans more than once,WMlesions of 96.0%(24 /25 cases)patients became silent or self -restored.Conclusions The clinical presentations of CSNHL combined with WM lesions are mild,not paralleled with their multiple foci.It is considered as demyelination or a delay of myelination.Due to its benign course, it is probably not the contraindication for the cochlear implantation.

Objective To study the association of vitamin D receptor(VDR) gene BsmI polymorphism and the genetic susceptibility of vitamin D deficiency rickets in infants and to explore a new way of diagnosis and treat-ment. Methods Case-control study was adopted. 56 infants confirmed with rickets (case group) and 76 cases of normal infants (control group) were chosen as the subjects. PCR-RFLP was applied to examine VDR gene BsmI site polymorphism. The frequencies of the VDR genotype and allele were compared between the two groups. Results Frequencies of BB,Bb and bb genotypes were 3.6% (2/56),21.4% (12/56) and 75.0% (42/56) in the rickets group,and 1.3% (1/76),18.4% (14/76) and 80.3% (61/76) in the control group respectively(χ20.521,P> 0.05),frequencies of B,b alleles were 14.3% (16/112),85.7% (96/112) in the rickets group and 10.5% (16/152),89.5% (134/152) in the control group respectively(χ20.783,P>0.05). Multiple logistic regression analysis showed that VDR gene polymorphism Bsml had not higher risk of vitamin D deficiency rickets in Infants. Conclusion VDR gene polymorphism BsmI doesn't appear to pose risk on infants in developing vitamin D deficien-cy rickets.

Objective To study inhibition of litsea cubeba oil on biofilm initial formation stage of Candida albicans ,in order to provide new sight for prevention and treatment of refractory infections arising from Candida albicans biofilm .Methods Observe the inhibition effect of different concentrations litsea cubeba oil on yeast budding by serum germ tube experiments .Results 2 -5μL/mL litsea cubeba oil could thoroughly inhibit budding growth of Candida albicans ,but haven′t antiseptic effect ,the inhibition rate of 0 .25 μL/mL litsea cubeba oil on Candida albicans germ was 85 .0% .Conclusion 2-5μL/mL litsea cubeba oil could completely inhibit the budding growth of Candida albicans ,but have no antiseptic effect .0 .25 μL/mL litsea cubeba oil could hardly inhibit the growth of buds .

Objective:To summarize the abnormalities in brain magnetic resonance imaging (MRI) and clinical manifestations of children with infantile spasms (IS) in the course of Vigabatrin (VGB) treatment.Methods:The imaging features of children with IS who took VGB orally and presented with brain MRI changes in Peking University First Hospital between September 2016 and June 2018 were analyzed retrospectively.Their use of VGB and the imaging findings were followed up.Meanwhile, the imaging and clinical features of 83 cases described in literature were summarized.Results:(1) Ten children diagnosed as IS were included.The average duration of VGB treatment at the time of imaging changes was 4.1 months, the average age was 11.8 months, and the average maximum dose was 90.6 mg/(kg·d). Brain MRI showed hyperintensities in bilateral thalamus, brainstem, basal ganglia and dentate nucleus diffusion-weight imaging (DWI), with or without T2WI, and T2 fluid attenuated inversion recovery(FLAIR) or slight hyperintensities.Brain MRI repeated in 5 patients 7-12 months later revealed that the original abnormal signals completely disappeared.Among them, 4 patients stopped using VGB and 1 patient continued to take VGB.(2) Literature review: 83 cases with IS treated with VGB from 16 literatures were reviewed, and the incidence of abnormal brain MRI was 22%-32%.The average age at initial VGB treatment was 8.0 months, and the average dose of VGB was 157.1 mg/(kg·d) when the brain MRI abnormalities were found.The MRI imaging showed high DWI signals in bilateral symmetrical thalamus, brainstem, basal ganglia (mainly pallidum) and dentate nucleus.During the follow-up of the 41 cases, no imaging abnormality was observed in 36 cases, improvement in 4 cases, and no significant change in 1 case.When MRI abnormalities were identified, 12.0%(10/83 cases) of the patients presented new clinical symptoms mainly in the extrapyramidal system, and the clinical symptoms of all children disappeared during the follow-up.Conclusions:During the course of VGB treatment of infantile spasms, brain MRI may suggest hyperintensities of DWI in the thalamus, brainstem, basal ganglia and dentate nucleus, but most are reversible.

Objective: To summarize the clinical features of leukoencephalopathy with vanishing white matter disease (VWM) in children. Methods: A retrospective cohort study was performed on 54 genetically diagnosed VWM patients in Peking University First Hospital from January 2007 to March 2019. Paper registration form and electronic medical record system were used to collect the data,and the children were divided into five groups according to the age of disease onset:<1 year, 1-<2 years, 2-<4 years, 4-<8 years and 8-<18 years respectively. The progression of motor function, episodic aggravation, epileptic seizures, survival time, brain magnetic resonance imaging (MRI) and genotype features were analyzed and compared. Non-parametric test, χ² test or Fisher′s exact test were used for comparison among groups; Kaplan-Meier survival curve was adopted to delineate the survival status of the children. Results: Fifty-four VWM patients were included in the study, including 34 males and 20 females.The age of disease onset was 2 years and 8 months (ranged from 6 months to 9 years and 7 months). Onset age was less than 1 year in 5 cases; onset age was 1-<2 years in 12 cases; onset age was 2-<4 years in 25 cases; onset age was 4-<8 years, in 10 cases; onset age was 8-<18 years in 2 cases; 94% (51/54) of patients had complaint of motor regression at the first visit; 87% (47/54) of patients suffered from episodic aggravation. Episodic seizures occurred in 43% (23/54) patients. In survivors with disease durations of 1-3 years, in 38% (9/24) patients the disease was classified as grades Ⅳ-Ⅴ by gross motor function classification system (GMFCS). For the onset age 1-<2 years group, 1 patient was classified as GMFCS Ⅳ among 3 survivors with disease durations of 1-3 years. As for the 2-<4 years group, 6 patients were classified as GMFCS Ⅳ-Ⅴ among 15 patients with disease durations of 1-3 years, whereas 1 patient was classified as GMFCS Ⅳ-Ⅴ among 4 patients with disease durations of 1-3 years in the 4-<8 years group. Lesions, liquefaction and diffusion restriction in brain MRI were compared among different groups, and it was revealed that the earlier the age of disease onset was, the more likely the subcortical white matter (frontal lobe P<0.01,temporal and parieto-occipital lobe both P=0.002), internal capsule (anterior limb P<0.01, posterior limb P=0.00) and brain stem (midbrain P=0.001, pons P<0.01) were to be involved. In addition, internal capsule (anterior limb P=0.002, posterior limb P=0.005) and brain stem (midbrain P=0.001, pons P=0.003) showed more diffuse restricted diffusion. Moreover, the subcortical white matter (frontal and parieto-occipital lobe both P<0.01, temporal lobe P=0.005) showed earlier rarefaction. The 1-year and 2-year survival rates of the overall patients were 81% and 75% respectively, while the 15-year survival rate was 45%. EIF2B5 gene variation was the most common, which accounts for 43% (23/54), followed by EIF2B3 (22%, 12/54). Conclusions The majority of VWM patients complained of motor regression at the first visit, episodic aggravation and epileptic seizures are common in the course. Earlier age at onset is associated with more rapid clinical progression, shorter survival time as well as more extensive lesions, liquefaction and diffusion restriction in brain MRI. The most common variant gene is EIF2B5, followed by EIF2B3.