Electromagnetic Fields ; Environmental Exposure ; Humans ; Radiation Dosage ; Threshold Limit Values

Spermatogenesis is a complex process. Current knowledge about human spermatogenesis is mainly based on the mouse model while little is known about the initial stage of this fundamental process in humans. The establishment of the model of spermatogenesis in vitro may contribute to an overall understanding of male germ cell development, an insight into the mechanisms of infertility, and clinical management of male infertility. This review summarizes current knowledge about the generation of germ cell-like cells from induced pluripotent stem cells (iPSCs) in vitro and discusses the potential application of iPSCs in the treatment of male infertility.
Animals ; Cell Differentiation ; Germ Cells ; Humans ; Induced Pluripotent Stem Cells ; Infertility, Male ; therapy ; Male ; Mice ; Spermatogenesis

BACKGROUND:Previous research has demonstrated human bone marrow mesenchymal stem cells(HMSCs)differentiate into hepatocyte-like cells;however,biological characteristics and differentiation mechanism remain unclear,and differentiation system remains immature.OBJECTIVE:To investigate the feasibility of hepatocyte growth factor(HGF)and epidermal growth factor(EGF)to induce the differentiation of HMSCs into hepatocyte-like cells.METHODS:HMSC5 were obtained from patients with esophageal cancer and were separated by density gradient centrifugation combined with attachment method.The phenotypes of MSCs were identified by flow cytometry.The third-passage HMSCs were divided into four groups:HGF(adding 20 μg/L HGF),EGF(adding 20 μg/L EGF),HGF+EGF,and blank control groups.Morphology was observed using inverted microscope.At days 7 and 14 after induction,α-fetoprotein and albumin mRNA expressions were detected using RT-PCR assay.RESULTS AND CONCLUSION:The HMSCs did not express hematopoietic cell CD34 and CD35,but strongly expressed β1-integrin CD29 and matrix receptor CD44.HMSCs changed from long fusiform shape to polygon or similar round shape in the HGF,EGF,and HGF+EGF groups.At days 7 and 14 after induction,α-fetoprotein and albumin mRNA expressions were positive.However,polygon cells were not observed in the blank control group,and α-fetoprotein and albumin mRNA expressions were negative.This suggested that HGF,EGF,and HGF+EGF could induce the differentiation of HMSCs into hepatocyte-like cells;however,their differentiation ability still needs to be further semi-quantitatively analyzed using immunohistochemical staining.

[ ABSTRACT] AIM:To study the influence of insulin resistance on fatty liver in the mice fed with high-fat diet (HFD).METHODS:Male 8-week-old C57BL/6J mice were randomly divided into HFD group (with 60% calories by high saturated fatty acid) and control group (with chow diet).The mice in both groups were fed for 12 weeks.The body weight, liver weight, serum triglyceride (TG) and total cholesterol (TC), and blood glucose and insulin levels were meas-ured.Hyperinsulinemic euglycemic clamp experiment was applied to reflect insulin sensitivity .The lipid deposition in the liver was analyzed by HE staining , Sudan IV staining and measurement of liver fat content .The phosphorylation levels of IRS1 and Akt, and the protein levels of SREBP-1 and FAS were determined by Western blot to reflect the activities of insu-lin signaling and lipid synthesis .RESULTS:Compared with control group , the body weight and liver weight were signifi-cantly increased in HFD group .TG and TC contents in serum and liver tissues were remarkably increased in HFD group . High-fat diet induced insulin resistance , as evidenced by increased serum insulin levels , reduced glucose infusion rate and decreases in IRS1 and Akt phosphorylation levels .In livers of HFD group, HE staining showed that the cytoplasm of hepa-tocytes was filled with vacuoles .Sudan IV staining also displayed that many different sizes of red lipid drops existed in the hepatocytes , and the protein levels of SREBP-1 and FAS were significantly increased .In primary normal hepatocytes with exogenous oleic acid intervention for 48 h, the phosphorylation levels of IRS 1 and Akt were reduced , and the protein ex-pression of SREBP-1 and FAS was significantly increased in a dose-dependent manner .CONCLUSION: Feeding with HFD leads to insulin resistance , resulting in activation of lipid synthesis and accumulation of lipid deposition in the liver , thus inducing fatty liver .

Electromagnetic Fields ; Threshold Limit Values

Objective: To determine the effects of intravenous anesthetics (fentanyl,midazolam and propofol )on inflammatory responses. Method: We employed carrageenan-sensitized endotoxemic rabbit model. Thirty-two New Zealand rabbits were randomly assigned to one of four groups,control group(no anesthetic was used), fentanyl group, midazolam group and propofol group. Different anesthetics were used intravenously for anesthesia induction and maintenance according to the group classification. Meanwhile, all animals were mechanically ventilated, then, 2?g?kg~(-1) lipopolysaccharide(LPS) were injected for endotoxin challenge. Result:In all groups, serum tumor necrosis factor (TNF)activity began to increase at 30 min,reached its maximal level at 60 min,and tended to decrease at 120 min after (LPS) challenge,and the significant increase of TNF activity was associated with development of hypotension. Meanwhile,serum phospholipase A_2(PLA_2)activity began to increase at 60 min and persisted in going up within 2h. Those animals,with continuous infusion of these three different anesthetics and mechanical ventilation,had much lower peak level of TNF and higher mean arterial pressure (MAP)than control levels, but their changes of serum PLA_2 activity had no significant difference from control level. Conclusion: With mechanical ventilation, intravenous infusion of these anesthetics can reduce LPS induced injury in the acute phase of endotoxemia, probably by the inhibition of TNF production.

Objective To evaluatethe effect of mTORC1 inhibitor on the proliferation in human pancreatic neuroendocrine tumors(pNET)cell line BON,to explore the function of glutamine metabolism in it.Methods In vitro cultured human pancreatic neuroendocrine tumors(pNET)cell line BON,BON cells were treated with different concentrations of rapamycin(1,5,10,25,50, 100 nM)for 12,24 h.Then CCK-8 assay are used to calculate the growth inhibitory rate.Rapamycin treated with BON 12 h,test the glutamine uptake level compared with control.Then deprive of glucose and/or glutamine,CCK-8 assay were used in observation of cell proliferation,cell cycle distribution was analyzed by flow cytomety.Results Rapamycin significantly inhibited the growth of BON cells in a time-and dose-dependent manner(P <0.05).Meanwhile,rapamycin can reduce the glutamine uptake level compared with control.BON obviously depends on glutamine for growth,without glucose and glutamine group have obvious difference in growth rate(P <0.05).Conclusion mTORC1 inhibitor can inhibit BON cells proliferation and influence the glutamine uptake lev-el.suggesting that mTORC1 inhibitor might inhibit BON cells proliferation by influenced the glutamine metabolic pathway.

Nasopharyngeal carcinoma (NPC) poses serious health problems in Southern China and yet the molecular mechanism of the carcinogenesis remains unclear. We used modern proteomic technologies to compare the protein expression profiles between the NPC cell lines (HNE1 and CNE1 ) and an immortalized nasopharyngeal epithelial cell line NP69 to identify cancer related proteins. Cell lysates were separated by two-dimensional gel electrophoresis (2 DE ) and analyzed by PDQuest software. The differentially expressed proteins were identified by matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry (MALDI-TOF/TOF-MS). We discovered 15 up-regulated proteins and 18 down-regulated proteins in both HNE1 and CNE1 cell lines compared with NP69. These proteins are correlative with various functions, such as cell proliferation, apoptosis, cancer metastasis, metabolism, cytoskeleton and signal transduction. Western blotting analyses were further carried out to verify the differential expression of individual proteins. Several identified proteins in our research might be used as potential molecular markers to understand the molecular mechanism of NPC development and metastasis, and might be used as candidate targets for NPC treatments.

AIM: To investigate whether Ligustrazine(LTZ) has an effect on the changes of protein kinase C(PKC) signaling pathway induced by inflammatory mediators involved in asthma in normal human peripheral blood lymphocytes (PBL). METHODS: 10 mL peripheral venous blood was obtained from each of 63 health humans and treated as follows. The activities of PKC from cytosolic and membrane fractions in PBL were measured by -ATP-catalyzing assay, after PBL had been isolated and performed by following processes: (1) First: three groups treated with 5 g/L LTZ(n=6) or 5 ?mol/L Ro31-8220 (n=6); Paired untreated PBL served as control of this group, as well as the negative controls of the following groups(n=6); (2)Second : three groups treated with 100 nmol/L Methacholine (Mch, n=5), 5 g/L LTZ+100 nmol/L Mch(n=5)or 5 ?mol/L Ro31-8220(a PKC inhibitor)+100 nmol/L Mch(n=5); (3)Third: three groups treated with 100 nmol/L histamine, 5 g/L LTZ+100 nmol/L histamine(n=5) or 5 ?mol/L Ro31-8220+100 nmol/L histamine(n=5); (4)Fourth: three groups treated respectively with 100 nmol/L PMA(a PKC activator, n=5), 5 g/L LTZ+100 nmol/L PMA(n=5) or 5 ?mol/L Ro31-8220+100 nmol/L PMA(n=5). RESULTS: (1)LTZ had no effect on the activities of PKC in inactive PBL in normal humans; (2) Methacholine or histamine resulted in an increase in membrane PKC activity of normal human PBL, which was partly suppressed by LTZ (all P

Objective To assess the value of tomographic ultrasound imaging (TUI) for prenatal analysis of the relative orientation of fetal heart and great arteries. Methods Volume datasets acquired from 12 patients of transposition of the great arteries (TGA) and 13 normal fetal heart were evaluated offline with TUI. The aortic valves (AV) and pulmonary valves (PV) were respectively showed on the two parallel slices. According to the pivot point in the middle of the PV in one slice, the relative orientation of the AV on another slices were analyzed. Results In the 12 patients of TGA confirmed postnatally, 7 were concomitant with single ventricle anomaly, AV was on the anterior-right orientation of the PV in 5, and was relatively on the anterior and anterior-left orientation in other 2 of them.In the remained 5 with seeming normal 4 chamber view, AV was found on the anterior-right of the PV in 3, and was relatively on the anterior and upright orientation.in other 2 patients. In 13 normal fetuses, TUI showed that all AV located on the posterior-right orientation to the PV. Conclusion TUI can provide detailed spatial information of the great arteries both in normal and abnormal fetal heart. It may be a convenient and veracious tool for prenatal exploring the morphology of the great arteries.