Chromatography, Gas ; Humans

China ; epidemiology ; Humans ; Occupational Diseases ; epidemiology ; prevention & control ; Surveys and Questionnaires ; Trimethyltin Compounds ; analysis ; poisoning

Air ; analysis ; Chromatography, Gas ; methods ; Ethylene Oxide ; analysis ; Furans ; analysis ; Methylene Chloride ; analysis ; Workplace

This article described the concept of the professional ethics and discussed the significance of the existence and construction of professional ethics on medical journal editors. The professional ethics on medical journal editors could be beneficial to correctly understand the ethical problems of medical journal editors and to promote the medical journal editors' role localization. It is very important to construct the Standardization of medical journal editors' behavior.

Objective To explore the residual undifferentiated mouse embryonic stem cells (ESCs) in embryoid bodies. Methods Mouse R1 and Oct-4-GFP transgenic ESCs were firstly cultured in suspension to form embryoid bodies (EBs). Twenty days later, EBs were digested into single cells and then re-plated in standard ESC culture condition. The morphology of residual undifferentiated cells in EBs was observed, and surface makers and in vitro redifferentiation potency of residual cells were examined by flow cytometry and immunofluoreseent staining. The residual cells were expanded and subcutaneously injected into nude mice, and the specimens were harvested from the injection site for histological analysis 6 weeks after injection. Results There were residual undifferentiated ESCs in EBs differentiated for 20 days, which displayed clonal morphology and expressed undifferentiated cell markers of ESCs, including SSEA1, CD31, CD9 and Oct-4. The cells could be differentiated to form EBs again, and could be re-expanded from secondary EBs. The residual cells were able to form teratoma at the injection site, and mature endoderm, mesoderm and ectoderm tissues could be found in teratoma tissues. Conclusion There are residual undifferentiated ESCs after differentiation of ESCs into EBs. The residual ESCs can differentiate again in vitro and in vivo, and can residue again in the in vitro differentiation.

BACKGROUNDHuman urotensin II (UII) is the most potent mammalian vasoconstrictor identified so far. Our previous study showed that UII is a potent mitogen of airway smooth muscle cells (ASMC) inducing ASMC proliferation in a dose-dependent manner. The signal transduction pathway of UII mitogenic effect remains to be clarified. This study was conducted to investigate the signal transduction pathway in the proliferation of ASMC induced by UII.

METHODSIn primary cultures of rat ASMCs, activities of protein kinase C (PKC), mitogen-activated protein kinase (MAPK) and calcineurin (CaN) induced by UII were measured. The effect of CaN on PKC and MAPK was studied by adding cyclosporin A (CsA), a specific inhibitor of CaN. Using H7 and PD98059, inhibitors of PKC and MAPK, respectively, to study the effect of PKC and MAPK on CaN. The cytosolic free calcium concentration induced by UII was measured using Fura-2/AM.

RESULTSUII 10(-7) mol/L stimulated ASMC PKC and MAPK activities by 44% and 24% (P < 0.01), respectively, after incubating for 20 minutes. It increased CaN activity in a time-dependent manner, being 1.68 times as that of control for 24 hours (P < 0.01). It promoted the cytosolic free calcium concentration increase of 18% (P < 0.01). CsA 10(-6) mol/L and H7 50 micromol/L inhibited UII-stimulated CaN activity by 45% (P < 0.01) and 21% (P < 0.05), respectively, while PD98059 50 micromol/L had no effect on CaN activity (P > 0.05). CsA 10(-6) mol/L inhibited UII-stimulated PKC activity by 14% (P < 0.05), while having no effect on MAPK activity (P > 0.05).

CONCLUSIONSUII increases cytosolic free calcium concentration and activates PKC, MAPK and CaN. The signal transduction pathway between PKC and CaN has cross-talk.

Animals ; Calcineurin ; metabolism ; Cells, Cultured ; Enzyme Activation ; Mitogen-Activated Protein Kinases ; metabolism ; Mitogens ; pharmacology ; Myocytes, Smooth Muscle ; cytology ; Protein Kinase C ; metabolism ; Rats ; Signal Transduction ; physiology ; Trachea ; cytology ; Urotensins ; pharmacology

OBJECTIVETo establish a method to detect N-methylacetamide (NMAC) concentration in urine of workers occupationally exposed to NMAC with directly injecting the sample into capillary gas chromatography.

METHODSAfter frozen urine samples were isolated from precipitation by centrifugation, the aliquot of supernatant was pretreated by protein precipitation with dilution of methanol. The methanol supernatant was separated by Polyethylene Glycol (PEG) capillary columns and detected by nitrogen phosphorous detector (NPD).

RESULTSGood linearity was obtained in the concentration range of 1.0 ∼ 250 mg/L. The correlation coefficient was 1.0000. The minimum detection limit of NMAC in urine was 0.2 mg/L. The method recovery rates were 96.0% ∼ 99.4% at three different concentrations. The mean recovery rate was 97.8%. The relative standard deviations (RSD) of intra- and inter-day were between 1.5% ∼ 3.4%.

CONCLUSIONThe method was simple, rapid, selective and sensitive and was applicable to detect the urinary NMAC concentration for monitoring occupational exposure levels.

Acetamides ; urine ; Chromatography, Gas ; methods ; Environmental Monitoring ; methods ; Humans ; Occupational Exposure ; analysis

OBJECTIVETo investigate the relationship between heat shock protein 72 (Hsp72) and DNA genetic damage in peripheral blood lymphocytes of coke oven workers and the role of Hsp72 in protection of cells from genetic damage induced by coke oven emissions.

METHODSTwo hundred and sixty-seven coke oven workers and thirty controls without occupational PAHs exposure were investigated. Benzo[a]pyrene concentrations in the ambient air individually collected were assayed by high performance liquid chromatography (HPLC). Western Blot was used to measure Hsp72 levels and Comet assay was used to evaluate DNA damage degree. Personal information was collected by questionnaire.

RESULTSThe Hsp72 level (G+/-S(G)) and olive comet tail moment (G+/-S(G) of peripheral blood lymphocytes in high-exposure workers (1.24 +/- 0.42 and 4.49 +/- 1.24) were significantly higher than those in low-exposure workers (1.01 +/- 0.35 and 2.99 +/- 1.10, P < 0.05) and control (0.85 +/- 0.34 and 2.40 +/- 1.00, P < 0.05) respectively. The Hsp72 median level of all subjects was used as the limit to divide subjects into high Hsp72 level group and low Hsp72 level group. The rate with high Hsp72 level was 36.7%, 43.1% and 58.3% in control, low exposure and high exposure workers respectively and had a rising tendency following exposure level (P = 0.003). In high Hsp72 level group Hsp72 level in high exposure workers was significantly higher than that in control (P < 0.05), and there was a rising tendency along with the increase of exposed levels. But the olive comet tail moment had no significant difference among three exposed groups (P > 0.05). In low Hsp72 level group there no difference among three exposed groups about Hsp72 levels. The olive comet tail moment in high exposure workers was significantly higher than that in low exposure workers and control (P < 0.01) and high exposure workers in Hsp72 positive group and there was a rising tendency along with the increase of exposed levels. Hsp72 levels had strong negative correlation with the olive comet tail moment (r = -0.503, P < 0.01) in high exposure workers.

CONCLUSIONThe coke oven emissions can induce hsp72 expression. Hsp72 play a role of protecting cells from DNA damage induced by coke oven emissions.

Adult ; Benzo(a)pyrene ; adverse effects ; Coke ; DNA Damage ; HSP72 Heat-Shock Proteins ; blood ; Humans ; Lymphocytes ; metabolism ; Male ; Occupational Exposure ; adverse effects

Adult ; Dandy-Walker Syndrome ; complications ; pathology ; Humans ; MELAS Syndrome ; complications ; pathology ; Magnetic Resonance Imaging ; Male

microRNAs (miRNAs) are a class of non-coding RNAs that function as endogenous triggers of the RNA interference pathway. Studies have shown that thousands of human protein-coding genes are regulated by miRNAs, indicating that miRNAs are master regulators of many important biological processes, such as cancer development. miRNAs frequently have deregulated expression in many types of human cancers, and play critical roles in tumorigenesis, which functions either as tumor suppressors or as oncogenes. Recent studies have shown that miRNAs are highly related with cancer progression, including initiating, growth, apoptosis, invasion, and metastasis. Furthermore, miRNAs are shown to be responsible for the cancer-related inflammation, anti-cancer drug resistance, and regulation of cancer stem cells. Therefore, miRNAs have generated great interest as a novel strategy in cancer diagnosis and therapy. Here we review the versatile roles of miRNAs in cancers and their potential applications for diagnosis, prognosis, and treatment as biomarkers.
Animals ; Biomarkers, Tumor ; Drug Resistance, Neoplasm ; genetics ; Epithelial-Mesenchymal Transition ; genetics ; Gene Expression Regulation, Neoplastic ; Gene Knockdown Techniques ; Genes, Tumor Suppressor ; Humans ; Inflammation ; genetics ; MicroRNAs ; genetics ; physiology ; Neoplasm Invasiveness ; genetics ; Neoplasm Metastasis ; genetics ; Neoplastic Stem Cells ; metabolism ; Oncogenes ; genetics