1.Confirming Indicators of Qualitative Results by Chromatography-mass Spectrome-try in Biological Samples
Shaodan LIU ; Daming ZHANG ; Wei ZHANG ; Wenfang ZHANG
Journal of Forensic Medicine 2017;33(2):181-188
B ecause of the exist of com plex m atrix, the confirm ing indicators of qualitative results for toxic substances in biological sam ples by chrom atography-m ass spectrom etry are different from that in non-biological sam ples. E ven in biological sam ples, the confirm ing indicators are different in various ap-plication areas. T his paper review s the sim ilarities and differences of confirm ing indicators for the ana-lyte in biological sam ples by chrom atography-m ass spectrom etry in the field of forensic toxicological analysis and other application areas. T hese confirm ing indicators include retention tim e (R T ), relative re-tention tim e (R R T ), signal to noise (S/N ), characteristic ions, relative abundance of characteristic ions, parent ion-daughter ion pair and abundance ratio of ion pair, etc.
2.Evaluation of eye injury degree of laser irradiation frequency and single duration
Yufei ZHANG ; Dongyu WEI ; Wei WANG ; Daming LIU ; Ze REN ; Xiangqian LI ; Tao CHEN ; Zuoming ZHANG
Chinese Journal of Experimental Ophthalmology 2021;39(3):184-190
Objective:To explore the effects of laser irradiation parameters (irradiation frequency and single duration) on tear secretion, lens and retina.Methods:Thirty-six healthy guinea pigs were randomly divided into 6 groups with random number table method according to different frequency and single exposure duration of laser to the eye, namely, high frequency short time (HFST) group, high frequency long time (HFLT) group, medium frequency short time (MFST) group, medium frequency long time (MFLT) group, low frequency short time (LFST) group and low frequency long time (LFLT) group, 6 for each group.The right eyes were irradiated with 500 lx laser as experimental eyes, and the left eyes of the guinea pigs served as the control eyes.The high, medium and low irradiation frequencies were defined as 15 times, 10 times and 5 times, respectively, and the short and long period was defined as 30 seconds and 60 seconds each time, respectively.The right eyes were irradiated based on the grouping at a 10-minute interval.The tear secretion was detected by SchirmerⅠtest; lens opacity was assessed under the slit-lamp microscope; fundus photography was performed to evaluate the general morphology of retina; retinal function was evaluated by electroretinogram (ERG) record and the thickness of retinal outer nuclear layer was measured by histopathology examination.This study protocol was approved by the Medical Ethics Committee of Air Force Military Medical University (No.20181203), and the use and care of the experimental animals complied with the ARVO statement.Results:The tear secretion was 8.00(7.37, 9.00), 8.75(8.25, 9.00), 8.50(7.75, 9.50), 9.00(8.50, 9.50), 8.00(7.37, 8.75) and 8.25(7.75, 8.75) mm/5 min in the HFST group, HFLT group, MFST group, MFLT group, LFST group and LFLT group, respectively, without significant difference among the groups(χ 2=5.502, P=0.240); after laser irradiation, there were no statistically significant differences in tear secretion between the control eyes and laser-irradiated eyes in all the groups (all at P>0.05). The lenses were clear and the fundus was normal through the experimental duration in all the groups.The amplitude of ERG a-wave was significantly reduced in the HFST group in comparison with the LFST group (P<0.05), and there was no significant difference in the b-wave amplitude among the six groups (F=1.358, P=0.268). The ERG a-, b-wave amplitudes were not significantly different between the control eyes and laser-irradiated eyes in various groups (both at P>0.05). There was no significant difference in the thickness of the outer nuclear layer of retina among the HFST group, HFLT group, MFST group, MFLT group, LFST group and LFLT group (F=0.952, P=0.463). Conclusions:The 500 lx laser irradiation is safe to ocular surface and lens, but there are some injuries to retinal function, and the injury degree is related to laser irradiation frequency.
3.Application of heterozygous ambiguity resolution primers resolving ambiguous genotyping results of human leukocyte antigen genes
Lianghong CHENG ; Hongyan ZOU ; Shizheng JIN ; Zhen LI ; Daming WANG ; Xi CHENG ; Yan JIANG ; Wei WANG
Chinese Journal of Laboratory Medicine 2009;32(1):40-43
Objective To evaluate the heterozygous ambiguity resolution primers (HARPs) method in resolving ambiguous genotyping results of human leukocyte antigen (HLA) genes in Chinese Hart population, and choose some appropriate HARPs primers. Methods HLA-A, HLA-B and HLA-DRB1 genes of 416 southern Chinese Han individuals were genotyped by sequence-based-typing(SBT) method and then the ambiguous genotyping samples were sequenced again by HARPs primers provided by American Atria company. Results The percentage of ambiguous genotyping samples resolved by HARPs for HLA-A, HLA-B and HLA-DRBI locus was 86.3% (132/153), 73.9% (130/176) and 38.1% (85/223) respectively. Among them, 48.5% (64/132)HLA-A, 80.0% (104/130)HLA-B and all HLA-DRB1(85/85)samples only need one primer, 47.7 % (63/132)HLA-A and 20.0% (26/130)HLA-B samples need two primers. Three to six different HARPs primers can resolve more than 90% ambiguities. Conclusion HARPs is a convenient method and could be a routine method to resolve ambiguities for HLA-A, HLA-B and HLA-DRB1 genes genotyped by SBT in Chinese Han population.
4.The relationship of Bel subgroup and the G952A mutation of the α1,3 galactosyltransferase gene
Zhihui DENG ; Qiong YU ; Yanlian LIANG ; Yuqing SU ; Daming WANG ; Tianli WEI ; Qian LI
Chinese Journal of Laboratory Medicine 2008;31(4):425-428
Objective To study the molecular genetic background of Bel subtype at ABO blood group.Methods Three samples and fifteen samples were diagnosed as Bel subgroup and normal control samples by serological test,respectively.The extracted DNA was genotyped by sequence specific primer- polymerase chain reaction foilowed by sequencing for Exon6 and exon7 at ABO locus and clones were sequenced.Results A novel Bel variant allele(GenBank EF117687) was identified in a Bel individual.The Bel allele was different from the regular B101 allele by single 952G>A missense mutation in exon7.resulting in an amino acid subsfitution of Val for Met at 318 locus.No mutations were detected in the fifteen control samples and the other two Bel allele samples.Conclusions The mutation position was fimt found to lie on coding region of ABO gene behind nucleotide 930.The mutation of G952A in the al,3 galactosyhransferase gene may be one of the molecular genetic basis of Bel ohenotype.
5.Optimization of electrode location and size on simulation in electric field distribution of atrial defibrillation.
Cong WANG ; Shengjun YANG ; Yi ZHENG ; Xiaomei WU ; Qunshan WANG ; Daming WEI
Chinese Journal of Medical Instrumentation 2014;38(2):88-93
A distributed simulation method of electric field based on the atrial defibrillation of the heart modeling and finite element solution is proposed in this study. In order to solve the problem that ordinary clinical trials could not measure the actual distribution of the defibrillation electric field in the heart accurately, this method provides a research tool for electrical defibrillation. A complete atrial anatomical structure in the heart model is used in the research, the finite element method is proceeded to solve; Three parameters: defibrillation threshold voltage, the high field strength rate and the defibrillation threshold energy are set to evaluate the effect of defibrillation. The heart electric field distributions of transvenous atrial defibrillation with different electrode locations or sizes are simulated. The simulation results and the reported results match fairly well, which initially verify the feasibility of this method.
Atrial Fibrillation
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therapy
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Computer Simulation
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Electric Countershock
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instrumentation
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methods
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Electrodes
6.Phosphorylation of Rictor at Thr1135 impairs the Rictor/Cullin-1 complex to ubiquitinate SGK1.
Daming GAO ; Lixin WAN ; Wenyi WEI
Protein & Cell 2010;1(10):881-885
The Rictor/mTOR complex plays a pivotal role in a variety of cellular functions including cellular metabolism, cell proliferation and survival by phosphorylating Akt at Ser473 to fully activate the Akt kinase. However, its upstream regulatory pathways as well as whether it has additional function(s) remain largely unknown. We recently reported that Rictor contains a novel ubiquitin E3 ligase activity by forming a novel complex with Cullin-1, but not with other Cullin family members. Furthermore, we identified SGK1 as its downstream target. Interestingly, Rictor, but not Raptor or mTOR, promotes SGK1 ubiquitination. As a result, SGK1 expression is elevated in Rictor(-/-) MEFs. We further defined that as a feedback mechanism, Rictor can be phosphorylated by multiple AGC family kinases including Akt, S6K and SGK1. Phosphorylation of Rictor at the Thr1135 site did not affect its kinase activity towards phosphorylating its conventional substrates including Akt and SGK1. On the other hand, it disrupted the interaction between Rictor and Cullin-1. Consequently, T1135E Rictor was defective in promoting SGK1 ubiquitination and destruction. This finding further expands our knowledge of Rictor's function. Furthermore, our work also illustrates that Rictor E3 ligase activity could be governed by specific signaling kinase cascades, and that misregulation of this process might contribute to SGK overexpression which is frequently observed in various types of cancers.
Animals
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Carrier Proteins
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metabolism
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Cell Proliferation
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Cells, Cultured
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Cullin Proteins
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genetics
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metabolism
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Fibroblasts
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metabolism
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Humans
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Immediate-Early Proteins
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metabolism
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Mice
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Phosphorylation
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Protein-Serine-Threonine Kinases
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genetics
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metabolism
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Proto-Oncogene Proteins c-akt
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genetics
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metabolism
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Rapamycin-Insensitive Companion of mTOR Protein
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TOR Serine-Threonine Kinases
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genetics
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metabolism
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Ubiquitin
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genetics
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metabolism
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Ubiquitination
7.Construction of a prediction model for prognosis of severe pneumonia patients combined with sepsis
Wei ZHANG ; Lu HUA ; Huiyu TAI ; Daming ZHOU
Chinese Journal of Clinical Infectious Diseases 2022;15(5):352-359
Objective:To construct a prediction model for prognosis of severe pneumonia patients combined with sepsis.Methods:Clinical data of 318 severe pneumonia patients combined with sepsis admitted at Taizhou People’s Hospital affiliated to Nanjing Medical University from March 2019 to March 2022 were retrospectively analyzed. Patients were randomized into a modeling set ( n=233) and a validation set ( n=85) with a 3∶1 ratio. In the modeling set there were 180 survival cases and 53 fatal cases according to the clinical outcomes within 30 days of admission. Multivariate Cox regression analysis was used to evaluate the independent prognostic factors for patients in the modeling set. A nomogram prediction model was constructed by R based on these prognostic factors and further verified using the data of the validation set with receiver operating curve (ROC), decision curve analysis (DCA), and calibrated with calibration curve analyses. Results:Multivariate Cox regression analysis suggested that septic shock ( HR=2.32, 95% CI 1.37-3.89, P=0.013) and neutrophil/lymphocyte ratio (NLR) ( HR=2.52, 95% CI 1.23-5.61, P=0.017) were independent risk factors for mortality in severe pneumonia patients combined with sepsis within 30 days of admission, while albumin/fibrinogen ratio (AFR) ( HR=0.64, 95% CI 0.41-0.83, P=0.011) and prognostic nutritional index (PNI) ( HR=0.68, 95% CI 0.57-0.83, P=0.009) were independent protective factors. The area under ROC curve (AUC) of the nomogram model based on these four indicators in the modeling and validation sets were 0.875 and 0.880, respectively. The DCA curve analysis indicated that the clinical benefit of this model was better than "All" or "None" curves in both the modeling and verification sets.The calibrate curve analysis indicated that the actual and corrected curves fitted well and were close to the ideal curve. Conclusion:The constructed nomogram model based on septic shock, AFR, NLR and PNI has a well prognostic value in severe pneumonia patients combined with sepsis.
8.Construction and Evaluation for Model of Goat Intervertebral Disc Degeneration Induced by Axial Compressive Stress
Xiaohui GUO ; Xizheng SONG ; Zhenxue HAN ; Xin CAO ; Yu KANG ; Daming LI ; Chaorong KANG ; Kai SHENG ; Hao ZHANG ; Lilin WEI
Journal of Medical Biomechanics 2021;36(2):E224-E230
Objective To establish the model of goat intervertebral disc degeneration (IDD) induced by controllable axial compressive stress and evaluate its imaging and pathological characteristics. Methods Twenty goats were randomly divided into 4 groups (control group, 4-week pressure group, 8-week pressure group, 12-week pressure group, n=5, 40 N pressure). Disc height index (DHI) was used to evaluate the change of intervertebral disc height by X-ray, Pfirrmann classification method was used to observe the degree of intervertebral disc degeneration by magnetic resonance imaging (MRI), and histopathological observation and evaluation for intervertebral disc were conducted by HE staining and immunohistochemistry. Results DHI in control group showed no significant changes with the extension of pressure time, while DHI in the experimental group gradually decreased. There was no significant change in Pfirrmann classification in control group. In experimental group, with the extension of time, the higher the degeneration aggravated with the Pfirrmann classification increasing. In experimental group, HE staining showed that the disc nucleus pulposus decreased in volume and nucleus pulposus cells, which were gradually replaced by fibrous tissues. Immunohistochemical staining showed that type I collagen in the nucleus pulposus gradually increased, type Ⅱ collagen gradually decreased, and intervertebral disc degeneration occurred. Conclusions A certain axial compressive stress can lead to degeneration of goat lumbar intervertebral disc, and the degree of degeneration is gradually increased with the extension of time.