Effects of pulsed electromagnetic field on differentiation of HUES-17 human embryonic stem cell line.

Electromagnetic fields are considered to potentially affect embryonic development, but the mechanism is still unknown. In this study, human embryonic stem cell (hESC) line HUES-17 was applied to explore the mechanism of exposure on embryonic development to pulsed electromagnetic field (PEMF) for 400 pulses at different electric field intensities and the differentiation of HUES-17 cells was observed after PEMF exposure. The expression of alkaline phosphatase (AP), stage-specific embryonic antigen-3 (SSEA-3), SSEA-4 and the mRNA level and protein level of Oct4, Sox2 and Nanog in HUES-17 cells remained unchanged after PEMF exposure at the electric field intensities of 50, 100, 200 or 400 kV/m. Four hundred pulses PEMF exposure at the electric field intensities of 50, 100, 200 or 400 kV/m did not affect the differentiation of HUES-17 cells. The reason why electromagnetic fields affect embryonic development may be due to other mechanisms rather than affecting the differentiation of embryonic stem cells.

Osthole protects lipopolysaccharide-induced acute lung injury in mice by preventing down-regulation of angiotensin-converting enzyme 2.

The renin-angiotensin-aldosterone system (RAAS) plays an important role in the pathogenesis of acute lung injury (ALI)/acute respiratory distress syndrome (ARDS). Angiotensin converting enzyme 2 (ACE2) plays a protective role in acute lung injury. Osthole, a natural coumarin derivative extracted from traditional Chinese medicines, is known to have anti-inflammatory effect, but the effect of osthole on the ALI is largely unknown. The aim of this study is to explore whether and by what mechanisms osthole protects lipopolysaccharide(LPS)-induced acute lung injury. Herein, we found that osthole had a beneficial effect on LPS-induced ALI in mice. As revealed by survival study, pretreatment with high doses of osthole reduced the mortality of mice from ALI. Osthole pretreatment significantly improved LPS-induced lung pathological changes, reduced lung wet/dry weight ratios and total protein in BALF. Osthole also inhibited the release of inflammatory mediators TNF-α and IL-6. Meanwhile, osthole markedly prevented the loss of ACE2 and Ang1-7 in lung tissue of ALI mice. ACE2 inhibitor blocked the protective effect of osthole in NR 8383 cell lines. Taken together, our study showed that osthole improved survival rate and attenuated LPS-induced ALI and ACE2 may play a role in it.

Primary epithelioid hemangioendothelioma in the clival region: a case report and literature review.

Epithelioid hemangioendothelioma (EHE) is a rare and low-grade vascular tumor, which usually occurs in the soft tissue, liver, breast, lung and skeleton. Here we submit a case with EHE of the clival region. A 58-year-old woman was admitted with a medical history of 3 months headache and 1 month visual deterioration. MRI revealed a well-circumscribed mass of 4.0 cm × 3.0 cm with bony invasion. The tumor was subtotally removed in a piecemeal fashion. Histologically, the tumor was composed of epithelioid cells with eosinophilic cytoplasm and intracytoplasmic vacuoles. Immunohistochemically, the tumor cells were positive for the markers CD31, CD34, factor VIII and vimentin. The pathological result was interpretated as EHE of the clival region. EHE is an uncommon vascular tumor, which is rarely seen in the clival region. Definitive diagnosis depends on histopathologic and immunohistochemical features.

Effects of electromagnetic pulse on bone metabolism of mice in vivo.

OBJECTIVE: To study the effects of electromagnetic pulse (EMP) on bone metabolism of mice in vivo. METHODS: Twenty-four male BALB/c mice were divided into a control group and 2 experimental groups (n=8). The whole-body of mice in experimental groups were exposed to 50 kV/m and 400kV/m EMP, 400 pulses daily for 7 consecutive days at 2 seconds intervals. Alkaline phosphotase (ALP) activity, serum calcium concentration and osteocalcin level and trabecular bone volume (BV/TV, %) were measured immediately after EMP exposure by biochemical, ELISA and morphological methods. RESULTS: The ALP activity, serum calcium concentration and osteocalcin level and BV/TV in experimental groups remained unchanged after EMP exposure. Conclusion Under our experimental conditions, EMP exposure cannot affect bone metabolism of mice in vivo.

[Change of oxygen free radical in reversing multidrug-resistance of human leukemic cell line HL-60/ADM by cyclosporin A].

This study was aimed to evaluate the reversed effects of cyclosporin A (CsA) on multidrug resistance (MDR) of human leukemic cell line HL-60/ADM, and to investigate the relationship of the oxygen free radical content between HL-60/ADM cells and the reversed HL-60/ADM cells (HL-60/ADM + CsA). The cytotoxicity and the reversed effects of CsA on multidrug resistance of human leukemic cell line HL-60/ADM were studied by MTT, flow cytometry (FCM) and immunohistochemical assay; the oxygen free radical for HL-60/ADM and HL-60/ADM + CsA cell lines were detected by colorimetric method. The results showed that the CsA less than 4 microg/ml had no significant cytotoxicity on HL-60/ADM, while the cytotoxicity was rised with CsA concentration increasing; And CsA (4 microg/ml) combined with ADM (1 microg/ml) could obviously restrain the growth of HL-60/ADM cells (p < 0.001). The P-gp expression of HL-60/ADM decreased obviously after exposure to CsA (4 microg/ml) for 72 hours, at the same cell conditions, MDA concentration of the reversed groups (HL-60/ADM + CsA cells) was higher than that of the control groups (HL-60/ADM cells) (p < 0.05), while the levels of SOD and GSH in the reversed groups were significantly lower than that in control groups (p < 0.001). It is concluded that MDR of HL-60/ADM can be reversed effectively by low dose of CsA, the level of oxygen free radical increases and the activity of antioxidants decreases in the reversed cells. Oxygen free radicals may be involved in this reverse process, which thereby lead to the cell death.

[The examination of ultraweak luminescence of HL-60 cells and adriamycin-resistant HL-60/ADM cells].

AIM: To explore the relationship between the ultraweak luminescence and adriamycin resistantance in human leukemic cells (HL-60) and human adriamycin resistant leukemic cells (HL-60/ADM). METHODS: MTT colorimetry, flow cytometry (FCM), growth curve and immunohistochemical staining were used to detect the sensitivity of HL-60 and HL-60/ADM cells to ADM, the change of cell cycle and the expression of P-glycoprotein(P-gp170). The intensity of the ultraweak luminescence of HL-60 cells and HL-60/ADM cells was examined by the IFFM-D chemiluminescence instrument. RESULTS: The sensitivity of HL-60/ADM cells to ADM was distinctly lower than that of HL-60 cells. The percentage of HL-60/ADM cells in G(0)/G(1) was 44.80%+/-1.97% and that in G(2)/M phase was 9.90%+/-0.27%, which was both higher than that of HL-60 cells. The percentage of HL-60/ADM cells in S phase was 45.30%+/-1.93%, which was lower than that of HL-60 cells. The doubling time of HL-60/ADM cells was 1.8 times as long as that of HL-60 cells. The expression of P-gp170 was positive in HL-60/ADM cells but negative in HL-60 cells.Treated with 10(-4) mol/L luminol and 3 mL/L H(2)O(2) and under four different cell concentration (8x10(7)/L,1x10(8)/L,1.26x10(8)/L, 2.73x10(8)/L), the intensity of ultraweak luminescence of HL-60/ADM cells was distinctly lower than that of HL-60 cells (P<0.05). CONCLUSION: The lower sensitivity to ADM, longer doubling time and the expression of P-gp170 showed the drug resistance of HL-60/ADM cells. With the obtaining of drug resistance, ultraweak luminescence intensity was lower in HL-60/ADM cells than that of HL-60 cells. It showed that the decreasing of intensity of ultraweak luminescence could be an index of examining drug-resistantce of tumor cells.

Genetic diversity of five Kobresia species along the eastern Qinghai-Tibet plateau in China.

Plants of the genus Kobresia are alpine grass species of high ecological and economic importance. Vegetative growth is the dominant means of reproduction for the Kobresia. Studies suggest that substantial vegetative growth can reduce genetic diversity and renders populations less able to buffer changing and extreme conditions. Kobresia are dominant species in the Qinghai-Tibet plateau in China where they face harsh conditions and frequent disturbance. The genetic diversity of five Kobresia species (K. humilis, K. royleana, K. kansuensis , K. tibetica and K. setchwanensis) from the Qinghai-Tibet plateau was assessed. The results reveal high genetic diversity at the population level for all of the species and there does not appear to be a relationship between altitude and genetic diversity. AMOVA analysis shows that most genetic variability resides among individuals within populations, whereas only a minor portion is found among populations. Of the five species, K. royleana and K. kansuensis have the highest levels of gene flow and the lowest genetic differentiation. While K. setchwanensis has the lowest gene flow and the greatest genetic differentiation. The level of gene flow between populations and the mating system play a critical role in the genetic structure of these Kobresia populations. Despite the predominance of vegetative growth enough sexual reproduction occurs to maintain the relatively high genetic diversity in Kobresia populations.