Detection of DNA methylation of HYAL2 gene for differentiating malignant from benign thyroid tumors / 南方医科大学学报

OBJECTIVE@#To assess the value of DNA methylation level of HYAL2 gene as a molecular marker for differential diagnosis of malignant and benign thyroid tumors.@*METHODS@#DNA methylation of HYAL2 gene in tissue specimens of 190 patients with papillary thyroid cancer (PTC) and 190 age- and gender-matched patients with benign thyroid tumors was examined by mass spectrometry, and the protein expression of HYAL2 was detected immunohistochemically for another 55 pairs of patients. Logistic regression analysis was performed to calculate the odds ratio (OR) and evaluate the correlation of per 10% reduction in DNA methylation with PTC. Receiver operating characteristic (ROC) curve analysis was performed and the area under curve (AUC) was calculated to assess the predictive value of alterations in HYAL2 methylation.@*RESULTS@#Hypomethylation of HYAL2_CpG_3 was significantly correlated with early-stage PTC (OR=1.51, P=0.001), even in stage I cancer (OR=1.42, P=0.007). Age-stratified analysis revealed a significantly stronger correlation between increased HYAL2_CpG_ 3 methylation and early-stage PTC in patients below 50 years than in those older than 50 years (OR: 1.89 vs 1.37, P < 0.05); ROC analysis also showed a larger AUC of 0.787 in younger patients. The results of immunohistochemistry showed that patients with PTC had significantly higher protein expressions of HYAL2 than patients with benign tumors.@*CONCLUSION@#The alterations of DNA methylation level of HYAL2 gene is significantly correlated with early-stage PTC, suggesting the value of DNA methylation level as a potential biomarker for differentiation of malignant from benign thyroid tumors.

GAD67-GFP expression and co-localization with bNOS in main olfactory bulb of GAD67-GFP knock-in mouse / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the distribution of GAD67 and the co-localization with bNOS in the main olfactory bulb of GAD67-GFP knock-in mouse.</p><p><b>METHODS</b>Polymerase chain reaction was applied to identify the genotype of GAD67-GFP knock-in mouse, the animals were sacrificed and frozen sections of olfactory bulb were prepared. The Nissl-staining was performed to show an framework of the neuron in the olfactory bulb. The distribution of GAD67 and co-localization with bNOS were detected by immunofluorescence technique.</p><p><b>RESULTS</b>The proportion of GAD67-positive cells among DAPI-positive cells were (42.98 ± 0.92)% in glomerular layer, (23.64 ± 0.84)% in mitral cell layer and (77.75 ± 0.84)% in granule cell layer; the bNOS-positive cells mainly existed in glomerular layer and mitral cell layer, very few in granule cell layer. No co-localization of GAD67 and bNOS in granule cell layer and mitral cell layer was found, but there was dispersed distribution in glomerular layer.</p><p><b>CONCLUSION</b>GAD67-positive neurons mainly appear in glomerular layer and granule cell layer, and the bNOS is mostly expressed in glomerular layer and mitral cell layer; while the co-localization of GAD67 and bNOS only occurs in glomerular layer of olfactory bulb.</p>

Formaldehyde inhalation may damage olfactory bulb and hippocampus in rats / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the effects of formaldehyde inhalation on the morphological damage, and Glu, GABA and NOS contents in olfactory bulb and hippocampus of rats.</p><p><b>METHODS</b>Twenty SD rats were equally divided into two groups: rats in the control group inhaled fresh air, while the animals in experimental group were exposed to the air containing formaldehyde (12.5 mg/m(3), 4 h/d) for 7 days. Then rats were sacrificed and frozen sections of olfactory bulb and hippocampus were prepared. The morphological changes were examined and the Glu, GABA and NOS contents were detected using Nissl-staining, immunohistochemistry and Western blot, respectively.</p><p><b>RESULT</b>Compared with the control group, there was a significant confusion and shrink of neuron morphology in experimental group, the number and staining intensity of Glu and NOS positive cells and protein contents were reduced. The protein expression of GABA was also decreased in the formaldehyde group.</p><p><b>CONCLUSION</b>Formaldehyde inhalation can cause a severe morphological damage of olfactory bulb and hippocampus in SD rats,which may further impair memory and learning ability through the reduction of Glu, GABA and NOS expression.</p>

Cultivation and karyotype analysis of the human embryonic stem cells HUES4 / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To establish a protocol for culturing of human embryonic stem cells (HUES4) without any animal-derived feeder cells and to investigate the karyotype stabilities of HUES4 cells after long-term cultivation.</p><p><b>METHODS</b>HUES4 cells were cultured on mitomycin C treated MEFs or human foreskin fibroblast feeder cells. The pluripotency of the ES cells was analyzed by immunocytochemistry staining to detect the expression of pluripotent marker, karyotype of the ES cells at passage 27, 34, 41, 44 and short tandem repeat (STR) at passage 27 were analyzed.</p><p><b>RESULTS</b>The HUES4 cells cultured on human feeder cells were positive for alkaline phosphatase activity, SSEA-4, TRA-1-60 and TRA-1-81 staining, but negative for SSEA-1. Analysis of karyotype at different passages suggested an abnormal karyotype 46, XY, t(9;15)(q22;q26) mosaicism occurred in HUES4, and the ratios of abnormal increased with passage.</p><p><b>CONCLUSION</b>HUES4 could be cultured without animal-derived feeder cells and the incidence of abnormal karyotype might be increased with long-term culture.</p>