OBJECTIVETo investigate the relationship among a 50-Hz MF-induced epidermal growth factor receptor (EGFR) clustering, acid sphingomyelinase (A-SMase) and ceramide (CER), and to explore the possible mechanism of receptor clustering.

METHODSHuman amnion (FL) cells were exposed to a 50-Hz sinusoidal magnetic field at 0.4 mT for 15 min with or without imipramine, a specific inhibitor of A-SMase and ceramide pretreatment. EGF treatment served as the positive control and DMSO treatment served as the solvent control. The EGFR was labeled with polyclonal anti-EGFR antibody and the clustering of EGFR was analyzed using immunofluorescence and confocal microscopy. The percentage of cells with EGFR clustering was counted and compared.

RESULTSBoth EGF treatment and 50-Hz MF exposure could induce EGFR clustering. However, the effect could be eliminated by imipramine pretreatment for 4 hours. When FL cells were incubated with ceramide following the imipramine pretreatment for 30 min, EGFR clustering induced by 50-Hz MF exposure could be recovered.

CONCLUSIONEGFR clustering induced by 50-Hz MF depends on A-SMase activity, and ceramide, as the hydrolyzate from A-SMase might participate in the process of EGFR clustering.

Amnion ; cytology ; Cell Line ; Cell Membrane ; metabolism ; radiation effects ; Ceramides ; metabolism ; Epithelial Cells ; metabolism ; radiation effects ; Humans ; Magnetic Fields ; adverse effects ; Receptor, Epidermal Growth Factor ; metabolism ; Sphingomyelin Phosphodiesterase ; metabolism ; physiology

OBJECTIVETo investigate the relationship among a 50 Hz magnetic field (MF)-induced epidermal growth factor receptor (EGFR) clustering,lipid rafts and acid sphingomyelinase (ASM), and to explore its possible mechanism.

METHODSHuman amnion FL cells were exposed to 50 Hz, 0.4 mT MF for 15 min. EGF treatment was used as positive control. Nystatin was employed to study lipid rafts since it could disrupt lipid rafts structure.The EGF receptors, ASM and lipid rafts were labeled with polyclonal anti-EGFR antibody, anti-ASM antibody and FITC-Cholera toxin B, respectively. The images were observed by laser confocal scanning microscope.

RESULTBoth EGF treatment and 50 Hz MF exposure could induce EGFR clustering; however, nystatin pretreatment disrupted this effect. MF exposure turned ASM (labeled with Cy3) from a diffused state in the sham exposure group to a concentrated state on the cell membrane, which co-localized with lipid rafts (labeled with FITC).

CONCLUSIONThe results suggest that the EGFR clustering induced by 50 Hz MF depends on intact lipid rafts on cellular membrane, and the ASM might participate in the process of EGFR clustering.

Cell Membrane ; radiation effects ; Cells, Cultured ; Electromagnetic Fields ; Epidermal Growth Factor ; metabolism ; Humans ; Membrane Microdomains ; radiation effects ; Receptor, Epidermal Growth Factor ; metabolism ; radiation effects ; Signal Transduction ; physiology ; radiation effects ; Sphingomyelin Phosphodiesterase ; metabolism

OBJECTIVETo establish a real-time reverse transcription-polymerase chain reaction (RT-PCR) for quantitative detection of E2A-PBX1 fusion gene mRNA in acute lymphoblastic leukemia (ALL) children and to explore its clinical significance in minimal residual disease monitoring and prognosis evaluation.

METHODSReal-time RT-PCR was used to quantitatively detect the mRNA expression of E2A-PBX1 gene in 11 newly diagnosed ALL patients at diagnosis (11 cases), complete remission (11 cases) and periods of relapse (3 cases). Ten children with normal bone marrow cell morphology and without hematopathy or tumor diseases were used as the control group.

RESULTSThe median expression levels of E2A-PBX1 fusion gene in the ALL group at diagnosis and the relapse group were significantly higher than in the control and complete remission groups (P<0.01). Compared with E2A-PBX1 negative patients on day 33 during induction of remission, the recurrence rate increased and disease free survival rate at 3 year decreased significantly in E2A-PBX1 positive patients decreased (P<0.05).

CONCLUSIONSMeasurement of E2A-PBX1 levels by real-time RT-PCR is useful for monitoing minimal residual disease, prediction of relapse and individual treatment. The expression level of E2A-PBX1 gene on day 33 during induction of remission can be used for prognosis evaluation.

Adolescent ; Child ; Child, Preschool ; Female ; Homeodomain Proteins ; genetics ; Humans ; Male ; Neoplasm, Residual ; diagnosis ; Oncogene Proteins, Fusion ; genetics ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; diagnosis ; genetics ; Prognosis ; Real-Time Polymerase Chain Reaction ; methods

OBJECTIVETo investigate the possible effect of exposure to GSM 1,800 MHz radiofrequency electromagnetic fields (RF EMF) on epidermal growth factor (EGF) receptor and its possible interference by noise magnetic fields (MF).

METHODSChinese hamster lung fibroblasts (CHL) were exposed to 1,800 MHz RF EMF (modulated by 217 Hz or 50 Hz, or unmodulated), 2 microT noise MF, and RF EMF combined with 2 microT noise MF for 15 min, respectively. The specific absorption rates (SARs) of RF EMF were 0.1, 0.5, 1.0, 2.0 and 4.0 W/kg. Commercial EGF (1 ng/ml) treatment was used as positive control. EGF receptors on the cell membrane were observed under a laser scanning confocal microscope after indirect immunofluorescence staining.

RESULTSEGF receptor clustering was induced after exposure to GSM 1,800 MHz RF EMF modulated by 217 Hz or 50 Hz MF at SARs of 0.5, 1.0, 2.0, 4.0 W/kg for 15 min as induced by 1 ng/ml EGF, but not at SAR of 0.1 W/kg. And no EGF receptor clustering was found in cells after exposure to unmodulated RF EMF or 2 microT noise MF. In addition, superposition of 2 microT noise MF could inhibit the EGF receptor clustering induced by GSM 1,800 MHz RF EMF.

CONCLUSIONEGF receptor clustering in CHL cells can be induced by GSM 1,800 MHz RF EMF at the lowest SAR of 0.5 W/kg and inhibited by noise MF. The modulation of wave may play an important role in the inducement of receptor clustering after RF exposure.

Animals ; Cell Line ; Cell Membrane ; metabolism ; radiation effects ; Cricetinae ; Cricetulus ; Dose-Response Relationship, Radiation ; Electromagnetic Fields ; Fibroblasts ; metabolism ; radiation effects ; Lung ; cytology ; Radio Waves ; Receptor, Epidermal Growth Factor ; metabolism

OBJECTIVETo study the possible induction effect of exposure to 50 Hz magnetic field (MF) on clustering of cell membrane surface receptors for epidermal growth factor (EGF) and tumor necrosis factor (TNF), the starting site of signals of biological effects, and its possible intervention effect.

METHODSLung fibroblasts of Chinese hamster (CHL) were exposed to EGF, TNF, 0.4 mT 50 Hz MF, 0.4 mT noise MF, and 0.4 mT 50 Hz MF combined with 0.4 mT noise MF. Respectively, for different durations, following the treatment, EGF and TNF receptors on the cell membrane were marked by corresponding antibodies with immunohistochemical method, then observed under a confocal microscope.

RESULTSClustering of cell membrane receptors could be induced 5 min after treatment with EGF and TNF, as well as with 50 Hz MF at 0.4 mT, which reached the peak in 15 min. While noise MF with the same intensity did not induce clustering of cell membrane receptors. Superposition of noise MF with the same intensity could inhibit clustering of cell membrane receptors induced by 50 Hz MF.

CONCLUSIONClustering of EGF and TNF receptors on the cell membrane could be induced by 50 Hz MF, suggesting that membrane receptors would be one of the sites where MF signals coupled, and noise MF with the same intensity could inhibit these effects.

Animals ; Cell Line ; Cricetinae ; Electromagnetic Fields ; adverse effects ; Epidermal Growth Factor ; pharmacology ; Fibroblasts ; drug effects ; metabolism ; radiation effects ; Noise ; adverse effects ; Receptor, Epidermal Growth Factor ; metabolism ; Receptors, Cell Surface ; metabolism ; Receptors, Tumor Necrosis Factor ; metabolism ; Tumor Necrosis Factor-alpha ; pharmacology

Objective To detect the resistance index and esterase activity of each generation of DDVP-resistant Culex mosquitoes and analyze the relationship between insecticide resistance and esterase. Methods WHO bioassay and micro-plate measurement were used for the detection. Results The resistance index increased to 12.17 after 43 generations' insecticide selection compared to 1.00 as sensitive isolate. The nonspecific esterase(NSE) activity of the mosquitoes became strengthened with the extension of the generations, and the individual frequency of those with OD values no less than 0.9 increased gradually, consistent basically to the bioassay. The AChE average inhibition rate decreased with the extended generation and increased resistance, and the individual frequency of those with inhibition rate less than 30% became strengthened with the extension of generations, showing a positive correlation. Conclusion The activity of NSE and AChE shows a correlation with DDVP resistance.

OBJECTIVETo investigate the expression of connective tissue growth factor (CTGF) in osteoarthritis chondrocytes, and the relationship between CTGF, macrophage colony-stimulating factor (M-CSF) and cartilage degeneration.

METHODSTen New Zealand white rabbits were randomly divided into the normal group and OA model group established by Hulth's method. Sections were stained with Safranin O for histological examination. The cartilage histological characteristics were observed according to the method of Mankin. Immunohistochemical staining was performed. Articular cartilages were observed with microscopy and the image analysis method was used to measure the expression intensity of CTGF and M-CSF in each group, and the correlations of the expression of CTGF, M-CSF and cartilage degeneration were analyzed by statistics.

RESULTSImmunohistochemical staining indicated that the expression intensity of CTGF, M-CSF in untreated group was significantly increased as compared with that in the normal group (P<0.05). Statistical analysis showed that there was a correlation between the expression of CTGF, M-CSF and cartilage degeneration (r=0.634, r=0.542, P<0.01 respectively).

CONCLUSIONThe expression of CTGF and M-CSF protein is up regulated in osteoarthritis chondrocytes, which suggests that the activation of M-CSF is involved in the production of CTGF. CTGF and M-CSF play an important role in the pathogenesis of cartilage degeneration.

Animals ; Cartilage ; pathology ; Chondrocytes ; chemistry ; pathology ; Connective Tissue Growth Factor ; analysis ; Female ; Immunohistochemistry ; Macrophage Colony-Stimulating Factor ; analysis ; Male ; Osteoarthritis ; metabolism ; pathology ; Rabbits

Objective of this study was to establish a SYBR Green Ireal-time reverse transcription-polymerase chain reaction (RT-PCR) for quantitative detection of WT1 gene mRNA in children with acute myeloid leukemia (AML) and investigate its clinical significance. SYBR Green Ireal-time RT-PCR was used to quantitatively detect the mRNA expression of WT1 gene in 30 newly diagnosed AML patients, 12 cases of remission (30), 18 relapsed patients and 30 cases of normal bone marrow cell morphology, and dynamically to detect the expression of WT1 gene in 20 newly diagnosed AML children. ABL served as internal reference gene, and the 2(-ΔΔct) method was used to calculate the relative expression. The results showed that (1) the expression of WT1 gene in newly diagnosed AML children was higher than that of the normal controls and the patients with remission (p < 0.001); there were no significant difference of WT1 gene expression between AML patients with remission and normal controls (p > 0.05), which were same as in relapsed patients and newly diagnosed patients (p > 0.05); (2) WT1 gene in 20 newly diagnosed AML children highly expressed before the children were initially treated, decreased when they were complete remission, then expression increased again when their AML relapsed. The WT1 gene expression level began to rise in 5 cases before clinical relapse at 5 - 7 months; (3) the complete remission rate (CR) and 3 year overall survival (OS) did not show significant difference between the WT1-positive group and negative group when dynamically monitoring WT1 gene expression of 20 newly diagnosed children with AML. 3-year OS of WT1-positive group at the 22 - 30 days after initial treatment was significantly lower than that of the negative group (p < 0.05). It is concluded that SYBR Green Ireal-time RT-PCR is a rapid, efficient, sensitive and specific method. WT1 gene in AML childhood plays a role of cancer-promoting. The change of WT1 gene expression level contributes to evaluate the therapeutic efficacy, detect the minimal residual diseases and analyze the prognosis.
Adolescent ; Child ; Child, Preschool ; Female ; Humans ; Infant ; Leukemia, Myeloid, Acute ; diagnosis ; genetics ; pathology ; Male ; Neoplasm, Residual ; diagnosis ; pathology ; Polymerase Chain Reaction ; methods ; Prognosis ; WT1 Proteins ; genetics

OBJECTIVETo identify antigenic proteins secreted by Streptococcus suis (S. suis) type 2 strain SC84.

METHODSTwo-dimensional electrophoresis (2-DE), western-blot assay and matrix-assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS) analysis were performed to search and identify antigenic proteins secreted by S. suis strain SC84, which triggered an outbreak of the disease in Sichuan province,China, in 2005.

RESULTSA total number of 14 western blot spots were found on PVDF membrane. 11 spots which could be found the existence of matching protein on coomassie G-250-stained 2-DE gel were identified by MALDI-TOF MS. The 11 proteins, all located at extra-cellular or cell wall, were classified into 8 kinds of proteins. Among of them, muramidase-released protein (MRP), suilysin (Sly) and extra-cellular factor (EF) were the known antigenic proteins, but several proteins such as putative 5'-nucleotidase, ribo-nucleases G and E, and predicted metal-loendo-peptidase were newly found antigenic proteins. All the identified protein were found to have had the coding gene in genomic of S. suis strain 05ZYH33, isolated from patients in Sichuan province, China in 2005.

CONCLUSIONThe newly found proteins could be used as voluntary antigens for detection and vaccination of S. suis.

Bacterial Proteins ; analysis ; immunology ; Humans ; Proteomics ; Streptococcal Infections ; Streptococcus suis ; immunology ; isolation & purification ; metabolism

OBJECTIVETo provide right time points in selection of right aged animals and the normal physiological data of TX mice.

METHODS7-12 months old TX and DL mice were studied, each group contained 3 female and 3 male mice of TX or DL mice. The concentration of copper in the serum, dry tissues (liver, brain and kidney), together with copper biochemistry indexes were measured. The liver histopathology was observed under light microscopy and electron microscope.

RESULTSTransaminase increased significantly only in 10 and 11-month- old (AST(TX10) = 218.3 U/L, AST(TX11) = 197.5 U/L, AST(DL10) = 171.5 U/L, AST(DL11) = 165.0 U/L, P(10) less than 0.001, P(11) = 0.022), but the copper concentration of liver, brain and kidney was significantly increased during 7-12 month old (the average concentration of copper, Liver(TX) = (750.0 +/- 85.5) mg/kg, Brain(TX) = (39.7 +/- 2.2)mg/kg, Kidney(TX) = (29.8 +/- 5.0) mg/kg, Liver(DL) = (11.6 +/- 1.5) mg/kg, Brain(DL) = (16.8 +/- 0.9) mg/kg, Kidney(DL) = (14.2 +/- 1.0) mg/kg, t = 21.16, 23.60, 7.47, for all these organs P less than 0.05).

CONCLUSIONTX mice is a suitable model of liver disease with natural recovery, so selecting animal model of suitable time point is very important.

Animals ; Aspartate Aminotransferases ; blood ; Brain ; metabolism ; Ceruloplasmin ; metabolism ; Copper ; metabolism ; Disease Models, Animal ; Female ; Kidney ; metabolism ; Liver ; metabolism ; pathology ; Liver Diseases ; blood ; metabolism ; pathology ; Male ; Mice ; Mice, Inbred Strains ; Time Factors