Forward genetic screening for zebrafish mutants defective in myelopoiesis / 南方医科大学学报

<p><b>OBJECTIVE</b>To identify zebrafish mutants with myelopoiesis defects by ENU mutagenesis and large-scale forward genetic screening.</p><p><b>METHODS</b>Male zebrafish were mutagenized with N-ethyl N-nitrosourea to induce mutations in the spermatogonial cells to generate the founders, which were outcrossed with AB to raise F1 fish. The F1 fish from different founders were mated to generate the F2 families. The F3 embryos from F2 sibling crosses were screened by Sudan black B staining and neutral red staining.</p><p><b>RESULTS</b>A total of 350 F2 families from F1 sibling crosses were screened, and 1424 F2 crosses were analyzed. Six mutations were identified resulting in abnormal Sudan black B staining and neutral red staining, indicating the involvement of neutrophil deficiency or macrophage abnormalities.</p><p><b>CONCLUSION</b>It is simple and cheap to induce and screen myelopoiesis deficiency in zebrafish by ENU chemical mutagenesis and Sudan black B staining and neutral red staining. These mutants shed light on the identification of the genes important to myelopoiesis in zebrafish.</p>

Regulation of resting intracellular Ca(2+) concentration of ventricular myocytes by beta(3)-adrenoceptor and its signaling pathway in rats with experimental heart failure / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the effect of beta(3)-adrenoceptor (AR) in regulating resting intracellular Ca(2+) concentration of the ventricular myocytes and investigate the signaling pathway in rats with experimental heart failure.</p><p><b>METHODS</b>Rat models of experimental heart failure were established by ligation of the anterior descending artery, and the myocytes were isolated by enzymatic digestion. The resting intracellular Ca(2+) concentration was determined using laser scanning confocal microscopy (LSCM) in the cells stimulated with 1 micromol/L BRL37344 (a selective beta(3)-AR agonist) alone or in combination with PTX, L-NAME, or methylene blue.</p><p><b>RESULTS</b>In the ventricular myocytes from normal control rats, BRL373444 reduced the resting intracellular Ca(2+) concentration of by 45.5%, while the reduction increased to 59.4% in the cells from rats with heart failure. In combination with L-NAME (10 micromol/L), methylene blue (10 micromol/L), and PTX (2 microg/ml), BRL373444 caused a reduction in resting intracellular Ca(2+) concentration of the ventricle myocytes from normal control rats by 10.1%, 16.9%, and 15.4%, respectively in control group, while the rate was 16.9%, 19.3%, and 11.7% in the heart failure group.</p><p><b>CONCLUSIONS</b>Beta(3)-AR agonist can decrease the resting intracellular Ca(2+) concentration of the ventricular myocytes, but the reduction is smaller in cells from rats with heart failure than in cells of normal rats. This effect is mediated through the PTX-NOS-NO pathway.</p>

Preparation of immunoaffinity column of zearalenone / 中华预防医学杂志

<p><b>OBJECTIVE</b>To prepare immunoaffinity column of zearalenone.</p><p><b>METHODS</b>The zearalenone immunoaffinity column (IAC) was prepared by coupling CNBr-activated Sepharose 4 Fast Flow (4FF) with the anti-zearalenone monoclonal antibody which was purified by caprylic acid-ammonium sulfate method. The coupling reaction was identified by UV-absorbance measurements, and the IAC prepared was evaluated by indirect-competition ELISA and HPLC.</p><p><b>RESULTS</b>The column capacity was determined to be 0.40 microg when using 0.5 ml of CNBr activated Sepharose 4FF and 350 microg of purified anti-zearalenone monoclonal antibody. The mean true recoveries were in the range 76.33% - 90.10% and RSD was 6.68% - 10.93% at levels of 60 microg/kg - 300 microg/kg. 30 samples of wheat and maize were detected by the anti-ZEN IAC produced by the laboratory, 17 samples were observed to be contaminated in a comparable range from 31.33 microg/kg - 377.84 microg/kg. Detection limit based on a signal-to-noise ratio 3:1 was 10. 00 microg/kg for ZEN in wheat and maize.</p><p><b>CONCLUSION</b>IAC, a simple separating method which is used in ZEN extraction from cereals, is able to purify and condense ZEN in one step. The cost of detection can be lowered down because the IAC developed is hopefully to substitute the imported IAC.</p>