Study on the improvement of image quality of 3.0 T fetal head MR scan by high dielectric constant / 中华放射学杂志

Objective:To explore the clinical application of a new high dielectric constant (HDC) to improve image quality in 3.0 T fetal head MR scans.Methods:Forty pregnant women who underwent 3.0 T fetal head MR examinations at the Drum Tower Hospital of Nanjing University School of Medicine from May to July 2021 were prospectively included and divided into a test group and a control group according to the placement and non-placement of HDC pads. After the scans were completed, qualitative and quantitative analysis were performed on the image quality of the two groups acquired in each case. Qualitative analysis: A 5-point scale was used to score the images of both groups by two diagnosticians and their scores were recorded. Quantitative analysis: Firstly, the overall radiofrequency specific absorption ratio (SAR) values of the two sets of fetal cranial cross-sectional scans of each pregnant woman were recorded separately, and the average rate of change of the overall SAR values was calculated; secondly, four regions of interest (ROIs) were placed on the standard level of the cross-sectional section of each fetal cranium (including the level of the basal ganglia region of the dorsal thalamus), and the minimum and maximum of the four ROIs of each of the two data sets were calculated separately. The ratio of minimum to maximum signal intensity (RSI), signal to noise ratio (SNR) and contrast to noise ratio (CNR) were calculated for each of the four ROIs in the two sets of data. Wilcoxon test was used to analyze the differences between the two groups of image quality score results; paired sample t-test or paired rank sum test was used to analyze the differences in SAR, RSI, SNR and CNR values between the two groups. Results:The fetal head image quality score was 4 (3, 4) in the test group and 3 (1, 4) in the control group, and the test group was significantly higher than the control group, with statistically significant difference ( Z=-3.62, P<0.01), and the images in the test group had a uniform signal compared with the control group, and none of them had significant artifacts. The results of quantitative analysis showed that the overall SAR value of the test group was significantly reduced, with a mean reduction rate of 32.1%, and the difference between the SAR values of the two groups was statistically significant ( Z=-2.78, P<0.01). The RSI, SNR and CNR in the frontal, temporal, thalamic and occipital lobes of the test group were all higher than those of the control group, and the differences were all statistically significant ( P<0.01). Conclusion:The HDC pads can significantly improve the image quality of 3.0 T fetal head imaging by reducing or eliminating the inhomogeneous artifacts in the RF field, which makes a good technical foundation for fetal head MR imaging.

The effectiveness evaluation of helicopter emergency medical services on transporting critical patients / 中华急诊医学杂志

Objective To explore the advantages and disadvantages of helicopter emergency medical services of South China in the long-distance transport for critical patients.Methods A total of 30 patients who received helicopter emergency medical services by Guangdong Generral Hospital from August 2004 to December 2014 were selected as the observation group,and the other 30 patients with similar conditions who received ground emergency medical services were selected as the control group.To analyses the difference between the two groups in the disease,transport distance,transportation time,costs and compliction by χ2-test,t-test and nonparametric test according types of data.Results There were significantly difference between two groups in transport distances (km) [578.0 (313.0,707.5)vs.214.5 (101.5,313.5),P 0.05).Conclusions Helicopter emergency medical services could shorten the transportation time of critical patients on long distance transportation,and improve the efficiency of first-aid.However,there were many disadvantages that need to be improved in the helicopter emergency medical service of China.

Clinical application of the blood transfusion with equal ratio component in severe multiple injuries with acute traumatic coagulopathy / 重庆医学

Objective To investigate the clinical effect of the blood transfusion with equal ratio component in severe multiple in‐juries with acute traumatic coagulopathy(ATC) .Methods Thirty‐eight patients who had severe multiple injuries with ATC were divided randomly into control group and treatment group .Control group was treated with the different ratio packed red blood cells (PRBC)and fresh frozen plasma(FFP) ,while treatment group received the equal ratio PRBC and FFP .Hemoglobin(HB) ,pro‐thrombin time(PT) ,international normalized ratio(INR) ,fibrinogen(FIB)were measured on the 1st ,2nd ,3rd day after admission . The total amount of PRBC during these 3 days ,the days of hospitalization in ICU ,the corrected rate of shock ,the 28‐day mortality were compared between groups .Results Compared with the control group ,the levels of PT ,INR and FIB of treatment group on the 2nd ,3rd day after admission were better(P<0 .05) .The total amount of PRBC[(18 .5 ± 6 .3)U]during these 3 days ,the days of hospitalization in ICU [(5 .9 ± 4 .3)d] in treatment group were less than those in the control group [(25 .9 ± 7 .8)U ,(10 .5 ± 7 .6)d] (P<0 .05) ,while the corrected rate of shock(85 .0% )in treatment group was higher than that of the control group(44 .4% ) .The 28‐day mortality(10 .0% )in treatment group was lower than that of the control group(27 .8% )(P<0 .05) .Conclusion The blood transfusion with equal ratio component in severe multiple injuries with ATC could not only improve blood clotting index ,reduce the total amount of PRBC and the time in ICU ,but also increase the corrected rate of shock and decrease the 28‐day mortality .

Role of calcineurin-nuclear factor of activated T cells signaling pathway in myoblast apoptosis induced by cyclic tensile strain / 华西口腔医学杂志

<p><b>OBJECTIVE</b>This study investigated the role and mechanism of calcineurin (CaN)-nuclear factor of activated T cells (NFAT) pathway in the myoblast apoptosis induced by cyclic tensile strain.</p><p><b>METHODS</b>Myoblasts were cultured using an in vitro-mechanical stimulation model and imposed with tension for different hours with a multi-channel cell stress loading system. Cyclosporine (CsA) was used as CaN inhibitor to clarify the role of CaN in the apoptosis induced by cyclic stress. Hochest 33258 staining and flow cytometry detection were performed to detect the apoptotic cells. Real-time polymerase chain reaction was conducted to detect the mRNA expression of CaN and NFAT. Protein levels of NFAT3 were evaluated by Western blot.</p><p><b>RESULTS</b>The apoptosis rate increased with the extension of loading time. The mRNA expression of the CaN subunits, CnA and CnB, and the protein levels of NFAT3 also increased. When the myoblasts were incubated with CsA, the apoptosis rate decreased, the mRNA expression of CnA and NFAT3 significantly decreased, and the NFAT3 protein expression levels became significantly lower than those of the groups without CsA.</p><p><b>CONCLUSION</b>Continuous cyclic tensile stress can induce myoblast apoptosis. The CaN-NFAT signaling pathway may be involved in the cyclic stretch-induced apoptosis of myoblasts.</p>

Effect of GPR56 on axonal development and myelination / 中华急诊医学杂志

Objective To determine the likelihood of G-protein coupled receptor 56 (GPR56 ) induces axonal development and myelination in the corpus callosum of mouse brain.Methods A total of 64 Gpr56 +/-and Gpr56 -/-mice were selected and randomly divided into two groups:Gpr56 +/-group (n=32)and Gpr56 -/-group (n=32).According to number of days after birth,each group was further divided into 4 subgroups including P7d,P14d,P21d and P28d subgroups.Levels of neurofilament-200 (NF -200)and proteolipid protein (PLP ) of myelin basic protein in corpus callosum were measured with immunohistochemistry staining and Western blot in P7d、P14d、P21d、P28d Gpr56 +/- and Gpr56 -/-mice.Gpr56 +/-and Gpr56 -/-neurons were cultured using P1 d Gpr56 +/-and Gpr56 -/-mouse brain.The lengths of Gpr56 +/- and Gpr56 -/-neuronal axon were measured and compared with Image J software. Axonal myelination in the corpus callosum of mouse brain in each group was observed under electronic microscopy and the axonal diameters between subgroups were compared.Results The levels of NF-200 and PLP in the corpus callosum in P7d、P14d、P21d、P28d Gpr56 -/-mice decreased significantly compared with Gpr56 +/- mice.The length of Gpr56 -/-neuronal axon was shortened compared with Gpr56 +/-neuronal axon.The number of myelinated axons was obviously reduced in the corpus callosum in P28d Gpr56 -/-mice.The diameter of axon in the corpus callosum of P28d Gpr56 +/-mouse is longer than that of P28d Gpr56 -/-mouse. Conclusions GPR56 may be involved in axonal development and myelination in the corpus callosum of mouse brain.

Methyl-metabolism contributes to the LuxS regulation of Streptococcus mutans / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the predominant contribution of methyl-metabolism pathway to the regulation of LuxS of Strecptococcus mutans.</p><p><b>METHODS</b>The differences in biofilm formation and aciduricity of Strecptococcus mutans among the methyl-metabolism-complementation strain (KO-S), the parental wide-type strain (WT) and the luxS null strain (KO) were observed by real-time PCR for monitoring the transcriptional level of genes related to biofilm formation (smu.238, gtfD) and aciduricity (smu.44, smu.46) of the studied strains, methyl thiazolyl tetrazolium (MTT) for quantifying the biofilm of the exhibited strains and confocal laser scanning microscopy for estimating the structure of the biofilm.</p><p><b>RESULTS</b>The transcriptional level of smu.44, smu.46, smu.238, gtfD in WT were 1.289 ± 0.051, 1.694 ± 0.140, 1.565 ± 0.107, 1.667 ± 0.196 respectively; in KO were 1.001 ± 0.045, 1.007 ± 0.151, 1.000 ± 0.021, 1.012 ± 0.196 respectively, downregulated compared with WT (P < 0.05); in KO-S were 4.662 ± 0.091, 5.019 ± 0.258, 3.462±0.029, 3.071 ± 0.136 respectively, upregulated compared both with KO and with WT (P < 0.05). The quantity of biofilms formed by the studied strains were WT (1.592 ± 0.213), KO (0.939 ± 0.029), KO- S (2.177 ± 0.226), KO- P (1.020 ± 0.093), respectively, representing a less quantity by KO and KO-P than WT (P < 0.05) and a more quantity by KO-S than other three stains (P < 0.05). According to the observation of biofilms texture by confocal laser scanning microscopy, the WT biofilm was condensed and even. In contrast, fissures and gaps were found scattered in biofilms of KO, KO-P while lessened in that of KO-S, in which high-density bacterial aggregates were observed. The acid assay indicated a smaller biofilm decrease by WT and KO-S than that by KO and KO- P(P < 0.05).</p><p><b>CONCLUSIONS</b>The methyl- metabolism pathway contributes to LuxS regulation on biofilm formation and auiduricity of Strecptococcus mutans.</p>

Application of receiver operating characteristic curve in the evaluation of predictive value of serum NT-proBNP in weaning outcome of patients with mechanical ventilation / 中华急诊医学杂志

Objective To evaluate the value of NT-proBNP in predicting weaning outcomes of the patients with mechanical ventilation by using the receiver operating characteristic (ROC)curve. Method The data of patients after the weaning of mechanical ventilation and spontaneous breathing trial (SBT) in the intensive care unit,from July 2008 to January 2010, were retrospective reviewed. All patients were divided into the success group and failure group as per the outcomes of weaning. Demographics and the serum NT-proBNP levels measured before weaning were compared between two groups with Student t -test and Chi-square test. The ROC curve was drawn to evaluate the value of serum NT-proBNP in predicting outcomes after weaning. Results A total of 160 patients were eligible for inclusion in the study, and there were 106 cases in success group and 54 cases in failure group.Compared with the failure group, the patients of success group were younger (63.17 ± 17.00 vs. 71.28 ± 12.56,t = 2.063,P =0.024), and no difference in gender (χ2 = 0.06, P ＞ 0.05). The NT-proBNP levels of failure group were significantly higher than those of success group (Lg NT-proBNP 2.80 ± 0.72 vs. 3.75 ± 0.56, t =2.351,P =0.014). The area under cure (AUC) of the ROC cure of NT-proBNPto predict the failure of weaning was 0.855 ±0.036 (95%CI0.784 ～ 0.925) when the cut-off level of NT-proBNP was 3635.5 pg/mL. And, this NT-proBNP level had a followed predictive efficiency in weaning outcome (Youden's index: 0. 60, accuracy:82.5%, sensitivity: 75%, specificity: 84.7%, positive likelihood ratio: 4.90, negative likelihood ratio:0.295,Kappa value: 0.62). Conclusions The levels of NT-proBNP before weaning have predictive value in weaning outcome, and it may be used as one of the screening indicators for weaning.