ABSTRACT
Objective To investigate the effect of endoplasmic reticulum stress on sensitivity of glioma cell line U87 to temozolomide (TMZ) and underlying mechanism.Methods (1) Glioma U87 cells were routinely cultured for 24 h in vitro;different concentrations of TMZ (0,12.5,25,50,100 μmol/L) were added to intervene the cell proliferation of U87 cells for 24 h;MTT method was used to detect the cellular proliferation inhibition rate,and half maximal inhibitory concentration (IC50) of TMZ was calculated;tunicamycin (TM) treatment (0,2,4,8 μmol/L) was given to the cells for 6 h,and then,50 μmol/L TMZ was given for 24 h,and cellular proliferation inhibition rate of U87 was detect by MTT method.(2) U87 cells were randomly divided into control group,TM group,TMZ group and TM+TMZ group;pretreatment of TM for 6 h was given to cells from TM group and TM+TMZ group;and 50 μmol/L TMZ was given to cells from TMZ group and TM+TMZ group;same amount of medium was given to cells from control group;24 h after treatment,the apoptotic rate was examined by flow cytometry;Westem blotting was used to detect the protein expressions of caspase-3,B-cell lymphoma 2 associated X protein (Bax),O-6-methlguanine-DNA methyltransferase (MGMT),glucose-regulated protein 78 (GRP78),and inositol-requiring enzyme 1 (IRE-l).Results (1) MTT showed that IC50 of TMZ was 50 μmol/L.As compared with that of 0 μmol/L TM+50 μmol/L TMZ group or 2 μmol/L TM+50 μmol/L TMZ group,the cellular proliferation inhibition rate of 4 μmol/L TM+50 μmol/L TMZ group and 8 μmol/L TM+50 μmol/L TMZ group was significantly decreased (P＜0.05).(2) As compared with TMZ group,TM+TMZ group had significantly decreased apoptotic rate (46.98％±4.79％ vs.35.74％ ±4.09％),significantly decreased caspase-3 and Bax protein expressions,and significantly increased MGMT,GRP78 and IRE-1 protein expressions (P＜0.05).Conclusion Endoplasmic reticulum stress can increase the resistance gene MGMT expression,decrease the chemotherapy sensitivity to TMZ,and induce chemoresistance ofglioma cell line U87.
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Objective To evaluate the miRNA change between hypothermia circulatory arrest at different temperature and its impact on intestinal protection.Methods Sixteen piglets were randomly(n =4) divided into four groups:deep hypothermia circulatory arrest (DHCA,18℃) group,moderate hypothermia circulatory arrest(MHCA,24℃) group,cardiopulmonary bypass(CPB) group and sham operation(SO) group.They were subjected to 80 min hypothermia circulatory arrest,305 min CPB or thoracotomy,respectively.Pick-and-mix custom miRNA real-time PCR panels were utilized to detect intestinal samples.miRNA expression between DHCA and MHCA were compared directly(DHCA vs.MHCA) and indirectly(DHCA/SO vs.MHCA/SO,DHCA/CPB vs.MHCA/CPB).Results Exposure to DHCA caused less intestinal miRNA dysregulation than MHCA.Besides,seven miRNAs(miR-122,miR-145-5p,miR-421-5p,miR-99a,miR-365-5p,miR-31 and miR-192)were differentially expressed between the two hypothermia circulatory arrest groups.Conclusion Better intestinal miRNA protection was provided by DHCA than MHCA.Intestinal miRNA were differentially expressed between hypothermia circulatory arrest at different temperature.
ABSTRACT
ObjectiveTo study the feasibility,efficacy and safety of u tilizing the laryngeal mask airway (LMA) ventilation compared with the endotracheal intubation ( ET ) in neonatal resuscitation for moderate and severe asphyxiated neonates.MethodsNeonates requiring positive pressure ventilation with heartrate ＜60 beats/min were collected and grouped quasi-randomizedly into LMA(36 cases) or ET(32 cases)ventilation.Differences of resuscitation effect,inserting time,successful once insertion rate and adverse reactions between the two groups were observed and compared.Results( 1 ) No significant difference was observed in Apgar scores at 1 min and 5 min between the two groups ( P＞0.05 ).(2) Success rate of once insertion was 94.4％ with average inserting time ( 7.58±1.16 ) s for LMP group,while it was 90.6％ and ( 7.89 ± 1.52) s for ET group.( 3 ) Successful resuscitation rate of LMA group ( 86.11％ ) was slightly lower than ET group (96.88％ ),but there was no statistical difference (P＞0.05).(4) Mean response time of LMA group [ (34.06 ± 10.56) s] was slightly lower than that of ET group [ (41.38 ±27.19) s],also ventilation time of LMA group [( 137.19 ±80.14) s] was slightly lower than that of ET group [ ( 171.09±84.28 ) s ],but neither showed statistical difference ( P＞0.05 ).(5) Adverse reactions were found in LMA group including nausea( 2 cases )and abdominal distention (1 cases),while there were laryngeal edema( 1 cases),pneumothorax(2 cases),respiratory tract bleeding( 1 cases) in ET group.ConclusionThe LMA ventilation is much easier to operate,with its effect no less than that of ET ventilation on resuscitation for moderate and severe asphyxiated cases,even it seems more safe.LMA ventilation can be a good substitute for ET ventilation,especially for those medical staffs who are unfamiliar with ET operation and primary hospital doctors in case of emergency.
ABSTRACT
The article introduced and stressed laryngeal mask airway(LMA)'s invention and development,structure and classification,history and current situation of the applications of LMA in neonatal resuscitation,placement methods,recommendation of international guidelines for neonatal resuscitation on LMA,advantage and disadvantage when LMA versus bag-mask and endotracheal intubation ventilation for neonatal resuscitation,LMA extensions of research in neonate,and significance and prospects of its application in China.