Detection and clinical significance of multidrug resistance-1 mRNA in bone marrow cells in children with acute lymphoblastic leukemia by real-time fluorescence quantitative RT-PCR

Objective： Multidrug resistance（MDR） is one of the most important reasons for treatment failure and recurrence of acute leukemia. Its manifestations are different in children with acute lymphoblastic leukemia（ALL） which may be due to different detection methods. This study was to detect the expression of MDR1 mRNA in bone marrow cells of children with ALL by real-time fluorescence- quantitative reverse transcription polymerase-chain reaction（FQ-RT-PCR）, and combine minimal residual desease（MRD） detection by flow cytometry（FCM） and to study their relationship with treatment response and prognosis of ALL. Methods：The MDR1 mRNA levels in bone marrow cells from 67 children with ALL[28 had newly diagnosed disease, 27 had achieved complete remission（CR）, 12 recurrent] and 22 children without leukemia were detected by FQ-RT-PCR. MRD was detected by FCM. The patients were observed for 9-101 months, with a median of 64 months. Results：Standard curves of human MDR1 and GAPDH genes were constructed successfully. MDR1 mRNA was detected in all children with a positive rate of 100%. The mRNA level of MDR1 was similar among the newly diagnosed ALL group, CR group, and control group（P 〉 0.05）, but significantly higher in the recurrence group than that in newly diagnosed disease group and control group（0.50 ± 0.55 vs. 0.09 ± 0.26 and 0.12 ± 0.23, P〈 0.05）. 54 ALL patients were followed up, and it was found that MDR1 mRNA level was significantly higher in ALL patients within 3 years duration than that of ALL patients with 3-6 years and over 6 years duration（0.63 ± 0.56 vs. 0.11 ± 0.12 and 0.04 ± 0.06, P〈 0.01）. For the 28 children with newly diagnosed disease, the MDR1 mRNA level was similar between WBC 〉 50 ~ 109 group and WBC〈50 × 10^9 group（P〉 0.05）. In the 33 CR patients, the MDR1 mRNA level was significantly higher in MRD〉10a group than that in MRD〈10a group（0.39 ± 0.47 vs. 0.03 ± 0.03, P 〈 0.05）. Conclusion：The sensitivity and specificity of FQ-RT-PCR in detecting MDR1 mRNA in bone marrowy cells of children with ALL patients are high. MDR1 mRNA is expressed in children with and without leukemia. MDR1 mRNA is highly expressed in the CR ALL patients with high MRD, recurrence and short duration（within 3 years）. Monitoring MRD and the MDR1 mRNA level might be helpful for individual treatment.

Diagnosis, treatment, and prevention of 2019 novel coronavirus infection in children: experts' consensus statement

Since the outbreak of 2019 novel coronavirus infection (2019-nCoV) in Wuhan City,China,by January 30,2020,a total of 9692 confirmed cases and 15,238 suspected cases have been reported around 31 provinces or cities in China.Among the confirmed cases,1527 were severe cases,171 had recovered and been discharged at home,and 213 died.And among these cases,a total of 28 children aged from 1 month to 17 years have been reported in China.For standardizing prevention and management of 2019-nCoV infections in children,we called up an experts' committee to formulate this experts' consensus statement.This statement is based on the Novel Coronavirus Infection Pneumonia Diagnosis and Treatment Standards (the fourth edition) (National Health Committee) and other previous diagnosis and treatment strategies for pediatric virus infections.The present consensus statement summarizes current strategies on diagnosis,treatment,and prevention of 2019-nCoV infection in children.

Influence of retinoic acid on TBX1 expression in myocardial cells induced by Shh and Fgf8

The aim of this study was to explore the regulatory mechanism of retinoic acid(RA)on the TBX1 gene expression in myocardial cells.Ventricular cardio-cytes were isolated from neonatal rats and cultured,and then treated with different concentrations of retinoic acid.The expression of Shh and Fgf8 at mRNA and protein levels in neonatal rat myocardial cells were measured by using RT-PCR and Western blot technique,respectively.There was basal expression of Shh and Fgf8 in the control group.When treated with 3�10–7 mol/L RA,we observed that the expression of Shh mRNA and protein in neonatal rat myocardial cells were up-regulated by 1.51(P<0.05)and 1.10 times(P<0.05),respectively.In comparison with the control group,under the concentra-tion of 5�10–7 mol/L RA,they were up-regulated by 2.21(P<0.05)and 2.38 times(P<0.05)individually.Mean-while,we could detect that the expression of Fgf8 mRNA and protein were up-regulated by 2.50 times(P<0.05)and 80%(P<0.05)separately compared with the control group after stimulation of 3�10–7 mol/L RA,and they were up-regulated by 3.48(P<0.05)and 2.04 times(P<0.05)individually after stimulation of 5�10–7 mol/L RA.The results indicated that RA could induce the expression of Shh and Fgf8 in neonatal rat myocardial cells.At the same time,it has shown that Shh and Fgf8 were involved in the regulation process of RA on TBX1 expression.

Epidemiological characteristics and clinical manifestations of pediatric patients with COVID-19 in China: A multicenter retrospective study

Importance:The Coronavirus disease 2019(COVID-19)global pandemic poses a considerable challenge for pediatricians.Objective:This study aimed to identify the epidemiological characteristics and clinical features of pediatric patients with COVID-19 in China.Methods:This multicenter retrospective study included pediatric patients from 46 hospitals in China,covering 12 provinces and two municipalities.Epidemiological,demographic,clinical,laboratory,treatment,and outcome data were analyzed.Results:In total,211 pediatric patients with COVID-19 were included in this study.The median age was 7.0 years(range:22 days to 18 years).Approximately 16.3%of the patients exhibited asymptomatic infections,23.0%had upper respiratory tract infections,and 60.7%had pneumonia,including two with severe pneumonia and one with critical illness.Approximately 78.7%of the pediatric patients occurred in familial clusters.The most three common symptoms or signs at onset in children with COVID-19 were fever(54.5%),cough(49.3%),and pharyngeal congestion(20.8%).Only 17.6%of the patients presented with decreased lymphocyte count,whereas 13.6%had increased lymphocyte count.Among the patients with pneumonia who exhibited abnormal chest computed tomography findings,18.2%(23/127)of the patients had no other symptoms.Generally,the chest radiographs showed abnormalities that affected both lungs(49.6%);ground-glass opacity(47.2%)was the most common manifestation.The cure and improvement rates were 86.7%(183/211)and 13.3%(28/211),respectively.Only one patient with an underlying condition received invasive mechanical ventilation;none of the patients died.Interpretation:Similar to adults,children of all age groups are susceptible to COVID-19.Fortunately,most pediatric patients have mild symptoms or remain asymptomatic,despite the high incidence of pneumonia.Decreased proportions of white blood cells and lymphocytes are less frequent in children than in adults.