Characteristics of continuous spike-and-wave during slow wave sleep syndrome in children / 中国当代儿科杂志

<p><b>OBJECTIVE</b>Continuous spike-and-wave during slow wave sleep (CSWS) syndrome is one of the presentations of electrical status epilepticus during sleep (ESES). The purpose of this study was to investigate the characteristics of CSWS syndrome in children.</p><p><b>METHODS</b>Between 2007 and 2009, a total of 778 nocturnal long-term or 24-hr video-EEG records were included. The EEG, clinical and neuroimaging characteristics were studied in children who met standard criteria for CSWS.</p><p><b>RESULTS</b>Nine children met standard criteria for CSWS in video-EEGs. Their ages ranged 6 to 13 years. Their EEGs were characterized by continuous spike-and-wave (SW) discharges during non-rapid eye movement (NREM) sleep, accounting for 85%-100% of the period of NREM sleep. Clinically, these children had various types of epileptic seizures and exhibited different degrees of neuropsychiatric impairments, language dysfunction, and/or behavioral disturbances. Neuroimaging abnormalities were found in 6 cases, including atelencephalia or atrophy, gray matter heterotopia and leucomalacia.</p><p><b>CONCLUSIONS</b>This study indicates the characteristics of CSWS syndrome in clinical manifestations, EEG and neuroimaging examinations. This will be helpful in understanding CSWS syndrome.</p>

Expression, purification, and characterization of the first three immunoglobulin-like domains of human stem cell factor receptor / 中国医学科学院学报

<p><b>OBJECTIVE</b>To express the first three immunoglobulin-like domains of human stem cell factor receptor (c-Kit/Ig1-3) in E. coli and HEK293 ET cells and study their binding activity for stem cell factor (SCF).</p><p><b>METHODS</b>In prokaryotic expression system, a double mutant form of c-Kit /Ig1-3 (c-Kit /Ig1-3(DM) was produced by overlap PCR and cloned into pET16b. The recombinant protein was expressed in E. coli BL21 (DE3) and refolded by dilution. In eukaryotic expression system, the gene of c-Kit/Igl13 with eight histidine segments was cloned into pEAK12 and the recombinant plasmid was transfected into HEK293 ET cells. The fusion protein was harvested from the growth medium and purified on Ni-NTA agarose column. The recombinant protein was tested for the receptor binding activity with his-tag pull-down and enzyme-linked immunosorbent binding assay.</p><p><b>RESULTS</b>In E. coli c-Kit /Ig1-3(DM) as produced as an inclusion body and showed low binding activity for SCF after refolding. Two HEK293 ET cell clones that express high levels of c-Kit/Ig1-3 were produced and each clone secreted 2p micro/ml of recombinant protein, whose relative molecular mass was about 58,000. Eukaryotically expressed c-Kit/Ig1-3 had specific binding activity for SCF, and the dissociation constant (Kd) was 9.39 nmol/L.</p><p><b>CONCLUSION</b>c-Kit/Ig1-3 with high receptor binding activity is successfully produced in HEK293 ET cells.</p>

Distribution characteristic of NDRG2 expression in human fetal tissues / 生理学报

NDRG2, one of the new N-Myc downstream-regulated gene (NDRG) gene families, is believed to be involved in cell growth event. However, the exact function is still unknown. Identification of the tissue or cell types expressing this gene in vivo will provide clues in clarifying its physiological roles. Using RT-PCR and Western blot, we analyzed the expression level of NDRG2 mRNA and protein in human fetal tissues from different gestational ages. The anti-NDRG2 monoclonal antibody, which has been proved to react specifically with NDRG2 protein, was further used to analyze the cellular location of NDRG2 protein in various human fetal tissues by immunohistochemistry. We found that NDRG2 expression was developmentally dynamic, being generally lower in the early stages of development and markedly increasing during the later stages. NDRG2 mRNA and protein distribution were generally consistent in heart and lung. One of the differences was that NDRG2 protein appeared later than mRNA in kidney. Another unmatched expression was found in liver. NDRG2 mRNA appeared later than protein in liver. In human fetal tissues at sixteen and twenty-eight weeks of gestation, NDRG2 protein immunoreactions could be seen in epithelium of small intestine, epithelium of large intestine, superficial layer of epidermis, whisker follicles, epithelium of small bronchus, hepatocytes, cardiac myocytes, thymus corpuscles and epithelium of renal tubule, and the immunoreactions in those tissues from twenty-eight weeks of gestation was stronger than that from sixteen weeks of gestation. In the present study, we demonstrate the expression pattern and cellular location of NDRG2 protein in a large set of human fetal tissues. This is the first demonstration of NDRG2 protein expression in human fetal tissues. Taken together, the results suggest that NDRG2 protein found in a variety of tissues is not a tissue-specific protein, and may play important roles in histogenesis and organogenesis.

Expression of human HSF in E. coli and its effects on mobilization of hematopoietic stem cells in rhesus monkeys / 中华血液学杂志

<p><b>OBJECTIVE</b>To study the expression of hHSF in E. coli and its effect on the mobilization of hematopoietic stem/progenitor cells.</p><p><b>METHODS</b>The hHSF gene was obtained by overlapping PCR and cloned into the vector pET30a to yield pET30a-hHSF, which was transformed into E. coli BL21(DE3) and expressed with IPTG induction. Subsequently, rhHSF was purified by gel filtration and cation exchange chromatography and subjected to refolding. Molecular weight of hHSF was measured by MALDI-TOF Mass Spectroscopy. The N terminal amino acid sequence rhHSF was determined by protein sequencing. rhHSF was profiled in rhesus monkey for mobilization of peripheral blood stem cells. Eight rhesus monkeys were equally divided into two groups. The first group was administered single subcutaneous injection of 500 microg/kg hHSF, while the other one was administered 10 microg.kg(-1).d(-1) G-CSF for 4 days followed by a single subcutaneous injection of 500 microg/kg rhHSF.</p><p><b>RESULTS</b>The sequence coding hHSF was confirmed by sequencing and the induced-expression level was about 30% of total cell proteins. The purity of target protein was over 95%. The sequence of N terminal 10 amino acids and the amino acid composition were consistent with the theoretical parameters; molecular weight of rhHSF was 7540. The peripheral CD34(+) cells, CFU-GM yields, and neutrophils peaked at 3 h (16.3-folds increase compared with baseline), 1 h (1.9-folds increase) and 45 min (4.4-folds increase) respectively after the single injection of rhHSF. The addition of rhHSF after the last dose of G-CSF boosted these levels to 25.8-folds, 8.7-folds and 8.3-folds respectively.</p><p><b>CONCLUSION</b>hHSF is highly expressed in E. coli and rapidly mobilizes the hematopoietic stem/progenitor cells and neutrophils in rhesus monkeys. hHSF shows distinct synergistic effect with G-CSF.</p>