Relationship between Immune Differentiation Antigen and Minimal Residual Disease in Childhood B-ALL / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To determine whether immune differentiation antigen is related with clinical features and minimal residual disease (MRD) in childhood B-cell precursor acute lymphoblastic leukemia (B-ALL), who were treated with CCCG-ALL-2015 protocol.</p><p><b>METHODS</b>A retrospective analysis was conducted in 132 B-ALL children, Multiparametric flow cytometry was used to analyze the immunophenotypes. The children were divided into 2 groups by MRD>0.1% on d 19 and / or d 46 after chemotherapy. The Wilcoxon rank-sum test and χ test were used for the comparison between groups, and P<0.05 was considered statistically significant.</p><p><b>RESULTS</b>CD19 (100%), CD22 (99.3%) and cCD79a (97.9%) were specific markers for patients with B-ALL, the CD13 and CD33 were mainly cross myeloid antigen. The significant differences were found between CD45 and CD45 in WBC counts when being firstly diagnosed (Z=6.845, P<0.01), risk stratification (χ=8.260, P<0.05) and prednisone poor responder (χ=18.420, P<0.01). Significant differences were found between CD10 and CD10 in age (Z=6.253, P<0.05), risk stratification (χ=6.699, P<0.05) and MRD (χ=4.951, P<0.05).</p><p><b>CONCLUSION</b>In CCCG-ALL-2015 protocol, the CD10 relates with the early MRD, suggesting a better prognosis, and reducing the adverse effects of CD20 and cross myeloid antigen on prognosis.</p>

Immunoprotective effect of combined pneumococcal endopeptidase O and pneumococcal surface adhesin A vaccines against Streptococcus pneumoniae infection / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the prokaryotic expression of proteins pneumococcal endopeptidase O (PepO) and pneumococcal surface adhesin A (PsaA) in Streptococcus pneumoniae and their immunoprotective effect as vaccine candidate proteins.</p><p><b>METHODS</b>Specific primers of target gene fragments were designed, and then PCR amplification was performed to establish recombinant plasmids pET28a(+)-pepO and pET28a(+)-psaA, which were transformed into host cells, Escherichia coli BL21 and DE3, respectively, to induce expression. Highly purified target proteins PepO and PsaA were obtained after purification. Mucosal immunization was performed for BALB/c mice and specific antiserum was prepared. ELISA was used to measure the antibody titer, and Western blot was used to analyze the specificity of the antiserum of target proteins. The mice were randomly divided into negative control group, PepO group, PsaA group, and PepO+PsaA combined immunization group, with 18 mice in each group. The models of different serotypes of Streptococcus pneumoniae infection were established to evaluate the immunoprotective effect of target proteins used alone or in combination.</p><p><b>RESULTS</b>The target proteins PepO and PsaA were successfully obtained and Western blot demonstrated that the antiserum of these proteins had good specificity. There was no significant difference in the titers of IgA in saliva and IgG in serum between the PepO group and the combined immunization group (P>0.05); however, these two groups had significantly higher antibody titers than the PsaA group (P<0.05). The PepO, PsaA, and combined immunization groups had significantly higher protection rates for mice infected with Streptococcus pneumoniae D39 and CMCC31436 in the nasal cavity than the negative control group (P<0.05). The PepO and combined immunization groups had a significantly higher protection rate for mice infected with Streptococcus pneumoniae D39 than the PsaA group (P<0.05). The results of colonization experiment showed that compared with the control group, the PepO, PsaA, and combined immunization groups showed a significant reduction in the colonization of Streptococcus pneumoniae (CMCC31693 and CMCC31207) in the nasopharynx and lung (P<0.05). The combined immunization group showed a better effect on reducing the colonization of CMCC31207 in the lung than the PepO and PsaA alone groups.</p><p><b>CONCLUSIONS</b>Combined PepO/PsaA vaccines may produce a better protective effect by mucosal immunization compared with the vaccine used alone in mice. The combined vaccines can effectively reduce the colonization of Streptococcus pneumoniae in the nasopharynx and lung. Therefore, such protein vaccines may have a great potential for research and development.</p>

Prognostic value of bone marrow hematogones in childhood B-lineage acute lymphoblastic leukemia / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the prognostic value of hematogones (HGs) for childhood B-lineage acute lymphoblastic leukemia (B-ALL) during consolidation chemotherapy.</p><p><b>METHODS</b>A retrospective analysis was conducted for 196 children with newly-diagnosed B-ALL. They were divided into high-risk group (n=55), intermediate-risk group (n=69), and low-risk group (n=72) by risk stratification, and into complete remission group (n=165) and relapse group (n=31) by clinical outcome. The European BIOMED-1 standard flow cytometry for minimal residual disease (MRD) was used to determine the number of HGs during consolidation chemotherapy. The Kaplan-Meier survival curve was used to assess event-free survival (EFS).</p><p><b>RESULTS</b>The high-risk group had a significantly lower number of HGs than the intermediate-risk and low-risk groups (P<0.05). The number of HGs in the complete remission group was significantly higher than in the relapse group (P<0.05). The children with HGs ≤1.0% had a significantly lower EFS than those with HGs <1.0% (P<0.05).</p><p><b>CONCLUSIONS</b>HGs can be used to assess the treatment outcome and prognosis in children with B-ALL, and proliferation of HGs reflects the good effect of chemotherapy in such children.</p>

Surveillance of childhood blood lead levels in Chengdu, China in 2010-2011

<p><b>INTRODUCTION</b>Lead poisoning has been receiving great attention around the world. The Child Hygiene Cooperation Center of the World Health Organization in China has been conducting investigations to monitor blood lead levels (BLLs) from as early as 2004. However, only several lead poisoning studies have been conducted in China since August 2009. The aim of the present study was to investigate the BLLs in children aged < 7 years and to analyse the risk factors of high BLLs in Chengdu, China.</p><p><b>METHODS</b>Questionnaires were distributed to children in Chengdu from 2010 to 2011. A total of 2,271 children were included in this study - 1,157 received BLL tests in 2010 and the remaining received the tests in 2011. BLL was measured using a tungsten atomiser absorption spectrophotometer.</p><p><b>RESULTS</b>The mean BLL of the 2,271 children was 6.2 µg/dL and 2.03% of the children had BLLs ≥ 10 µg/dL. Mean BLL seemed to increase with age. Unhygienic habits (e.g. not washing hands frequently, biting of toys and pencils), history of pica, use of coal and residence in an industrial zone were found to be the main risk factors contributing to high BLL (p < 0.05). Children with high BLLs have a higher risk of manifesting anorexia and/or abdominal pain as compared to those with low BLLs (p < 0.05).</p><p><b>CONCLUSION</b>The mean BLL of children in Chengdu (i.e. 6.2 µg/dL) was found to be higher than that of children in developed countries. Childhood lead poisoning remains a public health problem.</p>

Clinical value of minimal residual disease detection by flow cytometry in childhood B-cell acute lymphoblastic leukemia / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To elevate the prognostic value of minimal residual disease (MRD) detection by four-color flow cytometry with the antibody panel in childhood B-cell acute lymphoblastic leukemia (B-ALL).</p><p><b>METHODS</b>The clinical data of 183 children with newly-diagnosed acute B-ALL and who accepted MRD detection between October 2010 and March 2012 was retrospectively reviewed. According to the detection time and result of MRD, the 183 children were classified into four groups: MRD negative (n=37) and positive (n=18) in the induction chemotherapy and MRD negative (n=113) and positive (n=15) in the maintenance chemotherapy.</p><p><b>RESULTS</b>During both induction and maintenance chemotherapy, the percentage of patients at high and median risk in the MRD positive group was higher than in the MRD positive group (P<0.05). In the maintenance chemotherapy group, the 3- year cumulative incidence of relapse in MRD positive patients was higher than negative patients (P=0.04). The Cox's proportional hazards regression analysis showed that insensitive reaction for prednisone (RR=1.005, 95%CI: 0.864-1.170, P=0.032), bone marrow morphology that did not meet M1 on the 15th day (RR=6.454, 95%CI: 2.191-19.01, P=0.002) and MRD≥0.01% (RR=1.923, 95%CI: 0.750-4.933, P=0.043) were risk factors for relapse in children with B-ALL.</p><p><b>CONCLUSIONS</b>The four-color flow cytometry with the antibody panel can distinguish from MRD positive patients from negative patients with B-ALL. The result of MRD detection, as prednisone sensitivity and bone marrow morphology on the 15th day, is also a independent prognostic factor in children with B-ALL.</p>

An epidemiological study of food intolerance in 2434 children / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the epidemiological characteristics of intolerance to 14 foods in children and the relationship between food intolerance and disease of various systems.</p><p><b>METHODS</b>Serum samples of 2434 children with diseases were collected for food intolerance testing between January 2009 and October 2012. Allergen-specific IgG antibodies to 14 foods were detected using enzyme-linked immunosorbent assay. The children's intolerance to different foods and its relationship with age, sex and disease of various systems were analyzed.</p><p><b>RESULTS</b>Among these children, positive rates of intolerance to milk and eggs were as high as 74.16% and 66.47% respectively, while positive rates of intolerance to chicken and pork were relatively low (0.29% and 0.21% respectively). The overall positive rates of food intolerance were 12.579% and 12.470% in males and females respectively. For infants, the highest intolerance rate was to milk; for preschool and school-age children, the highest intolerance rates were to milk and eggs respectively; for children in adolescence, the highest intolerance rate was to eggs. Among children with food intolerance involving single system, those with developmental abnormality or immune system disease had the highest overall positive rate of food intolerance. Children with double-system diseases had an overall positive rate of food intolerance as high as 13.393%. Among the children involving various systems, the positive rate of intolerance to milk and eggs were higher than other food.</p><p><b>CONCLUSIONS</b>Factors influencing food intolerance in children include food categories and age. There may be a relationship between food intolerance and disease of various systems, and this is significant to the growth and development of children.</p>

Species and drug resistance of pathogens in blood cultures from the pediatric hematology ward / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the species and percentage changes of pathogens in blood cultures from the pediatric hematology ward, and to analyze the drug resistance of main pathogens and the risk factors for positive blood culture (sepsis).</p><p><b>METHODS</b>A retrospective analysis was performed to analyze the species and drug sensitivity of the pathogens isolated from 2358 blood cultures from the pediatric hematology ward of the West China Second University Hospital between 2008 and 2011, as well as the related clinical data.</p><p><b>RESULTS</b>A total of 110 strains of pathogens were isolated, with Escherichia coli (16 strains), Pseudomonas aeruginosa (12 strains) and Staphylococcus epidermidis (8 strains) being the most common ones. From 2008 to 2011, the percentage of Gram-positive bacteria decreased, while the percentage of Gram-negative bacteria increased. The detection rates of methicillin-resistant coagulase-negative Staphylococci and methicillin-resistant Staphylococcus aureus were 69% and 43% respectively, but both were sensitive to vancomycin. The detection rates of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and ESBL-producing Klebsiella pneumoniae were 69% and 62% respectively, but both were sensitive to imipenem and meropenem. Malignant tumor was a risk factor for positive blood culture (OR=3.564, P<0.05).</p><p><b>CONCLUSIONS</b>A wide range of pathogens are responsible for bloodstream infection in the pediatric hematology ward and the percentages of bacteria are changing; these pathogens have a high drug resistance rate. Malignant tumor is a risk factor for positive blood culture in the pediatric hematology ward.</p>

Common pathogens and clinical characteristics of neonatal pneumonia / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study common pathogens and their antibiotic susceptibility as well as clinical characteristics of neonatal pneumonia.</p><p><b>METHODS</b>A retrospective study on neonatal pneumonia was performed. The study investigated antibiotic susceptibility of four common pathogens (339 strains) that caused neonatal pneumonia. Clinical characteristics of the newborns with pneumonia were analyzed. Of the 339 strains, 185 were isolated from bronchial secretions, 72 from blood samples, and 82 with positive results of both samples.</p><p><b>RESULTS</b>Four hundred and seventy-four neonates with pneumonia presented positive results of bacterial culture. the most common pathogens Staphylococcus aureus (21.9%), Escherichia coli (19.2%), Klebsiella pneumoniae (19.0%) and Enterobacter cloacae (11.4%). The birth weight of newborns infected with Staphylococcus aureus was generally normal, and the time of hospital admission was later (after 24 hours of life). In contrast, the newborns with gram-negative bacterial infection, especially Klebsiella pneumoniae infection, had lower birth weights and early time of hospital admission (within 24 hours of life). Nearly more than 50% gram-negative bacteria were resistant to second, third and forth generation cephaloporins.</p><p><b>CONCLUSIONS</b>Gram-negative bacteria are predominant pathogens of neonatal pneumonia. Neonatal pneumonia caused by gram-negative bacteria is common in newborns with low birth weight and its onset time is relatively earlier. Gram-negative bacteria that cause neonatal pneumonia are highly resistant to cephaloporins.</p>

Clinical characteristics and pathogens of invasive fungal infections in children / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the clinical characteristics and pathogens of invasive fungal infection in children.</p><p><b>METHODS</b>The clinical data of 104 children who suffered from invasive fungal infections between 2008 and 2012 was retrospectively reviewed.</p><p><b>RESULTS</b>Of the 104 cases, 20 occurred in neonates, 48 in infants and 36 in preschool and school-aged children (old-aged children). Prematurity (70%), hyaline membrane disease (45%) and pneumonia (30%) were commonly comorbid in the neonate group. In addition, the percentage of cases receiving total parenteral nutrition was higher in the neonate group than in the other two age groups (P<0.01). Mechanical ventilation was more frequent in neonate and infant groups than in the old-aged children (P<0.01). Hematological malignancy was the most common underlying disease, and the percentage of children who had neutropenia and accepted chemotherapy was higher in the old-aged children than in the other two age groups (P<0.05). Lung infection was the most common (61.5%), followed by sepsis (14.4%) and intestinal tract infection (12.5%), while nervous system infections were found only in old-aged children. A total of 105 strains of fungi were isolated from the 104 patients, including Candida (n=90, 85.7%), Cryptococcus (n=6) and others (n=9). The most commonly isolated species was Candida albicans (n=52, 49.5%). Non-Candida albicans Candida accounted for 36.2% (n=38). The rate of susceptibility of Candida species to 5-fluorocytosine and amphotericin B was higher than fluconazole.</p><p><b>CONCLUSIONS</b>Invasive fungal infections can occur in children at various ages. There are differences in the risk factors for invasive fungal infections between age groups. Candida species are the main pathogens of childhood invasive fungal infections, and both Candida albicans and non-Candida albicans Candida are common. Fluorocytosine and amphotericin B are sensitive antifungal agents for infections caused by Candida species.</p>

FERMENTATION CONDITIONS OF SOYMILK-CLOTTING ENZYME PRODUCTION BY BACILLUS SP.AND STUDIES ON THE PROPERTIES OF THE ENZYM E / 微生物学通报

The optimum condition of shaking-flask p roducing enzyme were the tempe rature 26℃,initial pH 6 4,fermentation period 19 hours,medium volume 15mL m e dium/300mL Flask.soymilk-clotting enzyme was obtained from ammonium sulfate p r ecipitation.The optimum temperature and pH for the soymilk-clotting activity wa s 70℃and 5 8.The enzyme was easy to lose activity in acid or alkaline circumst a nce.About 60% of the original activity remained after 1 hour at 60℃.Ca 2+ ,Fe 2+ , Mg 2+ ,Na +increased the clotting activity,whereas Zn 2+ ,Al 3+ ca use inhibition.