Identification Strategy of Biological Half Sibling Relationship / 法医学杂志

OBJECTIVES@#To compare the application value of the likelihood ratio (LR) method and identity by state (IBS) method in the identification involving half sibling relationships, and to provide a reference for the setting of relevant standards for identification of half sibling relationship.@*METHODS@#(1) Based on the same genetic marker combinations, the reliability of computer simulation method was verified by comparing the distributions of cumulated identity by state score (CIBS) and combined full sibling index in actual cases with the distributions in simulated cases. (2) In different numbers of three genetic marker combinations, the simulation of full sibling, half sibling and unrelated individual pairs, each 1 million pairs, was obtained; the CIBS, as well as the corresponding types of cumulative LR parameters, were calculated. (3) The application value of LR method was compared with that of IBS method, by comparing the best system efficiency provided by LR method and IBS method when genetic markers in different amounts and of different types and accuracy were applied to distinguish the above three relational individual pairs. (4) According to the existing simulation data, the minimum number of genetic markers required to distinguish half siblings from the other two relationships using different types of genetic markers was estimated by curve fitting.@*RESULTS@#(1) After the rank sum test, under the premise that the real relationship and the genetic marker combination tested were the same, there was no significant difference between the simulation method and the results obtained in the actual case. (2) In most cases, under the same conditions, the system effectiveness obtained by LR method was greater than that by IBS method. (3) According to the existing data, the number of genetic markers required for full-half siblings and half sibling identification could be obtained by curve fitting when the system effectiveness reached 0.95 or 0.99.@*CONCLUSIONS@#When distinguishing half sibling from full sibling pairs or unrelated pairs, it is recommended to give preference to the LR method, and estimate the required number of markers according to the identification types and the population data, to ensure the identification effect.

Induction cell damage and change of nuclear factor-kappa B expression by bromoxynil in SH-SY5Y cells / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the cytotoxicity of bromoxynil on SH-SY5Y cells and its effect on the expression of nuclear factor-kappa B (NF-κB) and I kappa B alpha (IκBα) in SH-SY5Y cells.</p><p><b>METHODS</b>SH-SY5Y cells were exposed to bromoxynil (10, 50, or 100 µmol/L) for 24 and 48 h, and other SH-SY5Y cells, which were used as a control, were exposed only to dimethyl sulfoxide. After 24 and 48 h of exposure, the morphological changes of these cells were observed under an inverted microscope, and the cytotoxicity of bromoxynil was measured by MTT assay. The cellular proliferation was examined by cell counting after 12, 24, 48, 72, and 96 h of exposure. After 24 h of exposure, the expression of NF-κB was evaluated by Western blot and immunocytochemistry, and the expression of IκBα was evaluated by Western blot.</p><p><b>RESULTS</b>The cellular proliferation inhibition rates (CPIRs) of 50 and 100 µmol/L groups were significantly higher than that of the control group after 24 and 48 h of exposure (P < 0.05); the CPIR was significantly higher after 48 h than after 24 h in the two groups (P < 0.05). The growth curve revealed that these groups began to show differences in cell count at the 24th of exposure and that the differences were even more marked as the exposure went on (F = 17.15, P < 0.05). The control group had a significantly increased cell count at the 48th, 72nd, and 96th h of exposure (P < 0.05); the 10 and 50 µmol/L groups had a significantly increased cell count at the 72nd and 96th h of exposure (P < 0.05); the 100 µmol/L group showed no significant change in cell count during 96h of exposure. The 50 and 100 µmol/L groups hada significantly longer cell doubling time than the control group (P < 0.05). The immunocytochemistry showed that as the dose of bromoxynil increased, the brownish yellow particles in the cytoplasm and nuclei became darker, the expression of NF-κB was upregulated, and the nuclear translocation of NF-κB was increased. The Western blot showed that the 100 µmol/L group had significantly higher expression of NF-κB in the nuclei than the control group (P < 0.05) and that the 50 and 100 µmol/L groups had significantly lower expression of IκBα in total proteins than the control group (P < 0.05).</p><p><b>CONCLUSION</b>Bromoxynil can inhibit the proliferation of SH-SY5Y cells under this experimental condition, which may be related to activation of NF-κB.</p>

Study on mechanism of trimethyltin chloride-induced apoptosis in PC12 cells / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the effects of trimethyltin chloride (TMT) on proliferation, apoptosis, oxidative damage, and NF-κB expression in PC12 cells in vitro.</p><p><b>METHODS</b>PC12 cells were treated with 0, 0.3125, 0.6250, 1.2500, 2.5000, 5.0000, 10.0000, and 20.0000 µmol/L TMT for 24 and 48 h, and MTT assay was used to evaluate cell viability. PC12 cells were treated with 1.25, 2.50, 5.00, and 10.00 µmol/L TMT for 12 and 24 h, and flow cytometry was used to measure the apoptotic rates of cells. PC12 cells were treated with 1.25, 2.50, 5.00, and 10.00 µmol/L TMT for 6 h, and the reactive oxygen species (ROS) and glutathione (GSH) levels were measured. PC12 cells were treated with 1.25, 2.50, 5.00, and 10.00 µmol/L TMT for 12 h, and Western blot was used to measure NF-κB levels.</p><p><b>RESULTS</b>Compared with solvent controls, the PC12 cells treated with 2.5000, 5.0000, 10.0000, and 20.0000 µmol/L TMT for 24 h showed significantly decreased cell viability (P < 0.05); the PC12 cells treated with 1.2500, 2.5000, 5.0000, 10.0000, and 20.0000 µmol/L TMT for 48 h showed significantly decreased cell viability (P < 0.05). The PC12 cells treated with 1.2500, 2.5000, 5.0000, and 10.0000 µmol/L TMT for 12 h had apoptotic rates of 15.30% ± 0.75%, 18.90% ± 0.61%, 22.00% ± 0.60%, and 36.50% ± 0.66%, respectively, and the PC12 cells treated with 1.25, 2.50, 5.00, and 10.00 µmol/L TMT for 24 h had apoptotic rates of 28.6% ± 0.40%, 43.54% ± 2.00%, 65.73% ± 0.71%, and 74.67% ± 0.40%, respectively, all significantly higher than those of the control group (12 h: 12.80% ± 1.00%, 24h: 16.83% ± 0.25%) (P < 0.05). The ROS fluorescence intensities of the PC12 cells treated with 1.25, 2.50, 5.00, and 10.00 µmol/L TMT were 1.42, 1.71, 1.78, and 1.89 times that of the control group (P < 0.05); the PC12 cells treated with 2.50, 5.00, and 10.00 µmol/L TMT had GSH levels of 0.17 ± 0.0, 0.20 ± 0.04, and 0.07 ± 0.03 µmol/µg protein, significantly lower than that of the control group (0.30 ± 0.01 µmol/L protein) (P < 0.05). The PC12 cells treated with 2.50, 5.00, and 10.00 µmol/L TMT had significantly higher expression of NF-κB p65 than the control group (P < 0.05).</p><p><b>CONCLUSION</b>Under our laboratory conditions, TMT can significantly inhibit proliferation and induce apoptosis in PC12 cells, which may be related to oxidative stress and NF-κB signaling pathway activation.</p>