Detecting Double Expression Status in Primary Central Nervous System Lymphoma Using Multiparametric MRI Based Machine Learning.

BACKGROUND: Double expression lymphoma (DEL) is a subtype of primary central nervous system lymphoma (PCNSL) that often has a poor prognosis. Currently, there are limited noninvasive ways to detect protein expression. PURPOSE: To detect DEL in PCNSL using multiparametric MRI-based machine learning. STUDY TYPE: Retrospective. POPULATION: Forty PCNSL patients were enrolled in the study among whom 17 were DEL (9 males and 8 females, 61.29 ± 14.14 years) and 23 were non-DEL (14 males and 9 females, 55.57 ± 14.16 years) with 59 lesions (28 DEL and 31 non-DEL). FIELD STRENGTH/SEQUENCE: ADC map derived from DWI (b = 0/1000 s/mm2 ), fast spin echo T2WI, T2FLAIR, and contrast-enhanced T1 weighted imaging (T1CE) were collected at 3.0 T. ASSESSMENT: Two raters manually segmented lesions by ITK-SNAP on ADC, T2WI, T2FLAIR and T1CE. A total of 2234 radiomics features from the tumor segmentation area were extracted. The t-test was conducted to filter the features, and elastic net regression algorithm combined with recursive feature elimination was used to calculate the essential features. Finally, 12 groups with combinations of different sequences were fitted to 6 classifiers, and the optimal models were selected. STATISTICAL TESTS: Continuous variables were assessed by the t-test, while categorical variables were assessed by the non-parametric test. Interclass correlation coefficient tested variables' consistency. Sensitivity, specificity, accuracy F1-score, and area under the curve (AUC) were used to evaluate model performance. RESULTS: DEL status could be identified to varying degrees with 72 models based on radiomics, and model performance could be improved by combining different sequences and classifiers. Both SVMlinear and logistic regression (LR) combined with four sequence group had similar largest AUCmean (0.92 ± 0.09 vs. 0.92 ± 0.05), and SVMlinear was considered as the optimal model in this study since the F1-score of SVMlinear (0.88) was higher than that of LR (0.83). DATA CONCLUSION: Multiparametric MRI-based machine learning is promising in DEL detection. EVIDENCE LEVEL: 4 TECHNICAL EFFICACY STAGE: 2.

Differential diagnosis of mitochondrial encephalopathy with lactic acidosis and stroke-like episodes (MELAS) and ischemic stroke using 3D pseudocontinuous arterial spin labeling.

PURPOSE: To evaluate the efficacy of 3D pseudocontinuous arterial spin labeling (3D pCASL) in the differential diagnosis between mitochondrial encephalopathy with lactic acidosis and stroke-like episodes (MELAS) and acute ischemic stroke (AIS). MATERIALS AND METHODS: Conventional magnetic resonance imaging (MRI) including T2 -weighted imaging (T2 WI) and diffusion-weighted imaging (DWI), and 3D pCASL perfusion data were obtained on a 3.0T MR scanner in 16 newly appearing lesions in nine patients with MELAS and 14 acute lesions in 12 patients with AIS. A postlabeling delay (PLD) time of 2025 msec was applied. The cerebral blood flow (CBF) values were measured in the central part and the peripheral part of the lesions and the CBF values were compared between MELAS and AIS patients. RESULTS: The lesions of both MELAS and AIS showed high signal intensity on T2 WI and demonstrated hyperintensity on DWI. Compared with the perfusion defects or hypoperfusion in all AIS, hyperperfusion was revealed in 16 acute MELAS lesions, especially in the peripheral part of the lesions. The CBF values of 16 lesions in MELAS were 11.20-73.11 ml/100g/min in the central part and 65.33-169.11 ml/100g/min in the peripheral part. The CBF values of 14 lesions in AIS were 12.32-19.94 ml/100g/min in the central part and 11.66-18.37 ml/100g/min in the peripheral part. The CBF value of the peripheral part (119.80 ± 35.41) in MELAS was significantly higher than that (14.66 ± 2.61) in AIS (P = 0.0001). CONCLUSION: The whole-brain 3D pCASL technique might be useful in differentiating MELAS from AIS. LEVEL OF EVIDENCE: 3 J. Magn. Reson. Imaging 2017;45:199-206.

Astrocytic tumour grading: a comparative study of three-dimensional pseudocontinuous arterial spin labelling, dynamic susceptibility contrast-enhanced perfusion-weighted imaging, and diffusion-weighted imaging.

OBJECTIVES: We hypothesized that three-dimensional pseudocontinuous arterial spin labelling (pCASL) may have similar efficacy in astrocytic tumour grading as dynamic susceptibility contrast-enhanced perfusion-weighted imaging (DSC-PWI), and the grading accuracy may be further improved when combined with apparent diffusion coefficient (ADC) values. METHODS: Forty-three patients with astrocytic tumours were studied using diffusion weighted imaging (DWI), pCASL, and DSC-PWI. Histograms of ADC and normalized tumour cerebral blood flow values (nCBF on pCASL and nrCBF on DSC-PWI) were measured and analyzed. RESULTS: The mean 10 % ADC value was the DWI parameter that provided the best differentiation between low-grade astrocytoma (LGA) and high-grade astrocytoma (HGA). The nCBF and nrCBF (1.810 ± 0.979 and 2.070 ± 1.048) in LGA were significantly lower than those (4.505 ± 2.270 and 5.922 ± 2.630) in HGA. For differentiation between LGA and HGA, the cutoff values of 0.764 × 10(-3) mm(2)/s for mean 10 % ADC, 2.374 for nCBF, and 3.464 for nrCBF provided the optimal accuracy (74.4 %, 86.1 %, and 88.6 %, respectively). Combining the ADC values with nCBF or nrCBF could further improve the grading accuracy to 97.7 % or 95.3 %, respectively. CONCLUSIONS: pCASL is an alternative to DSC-PWI for astrocytic tumour grading. The combination of DWI and contrast-free pCASL offers a valuable choice in patients with risk factors. KEY POINTS: • pCASL shows positive correlation with DSC-PWI in astrocytic tumour grading. • ADC values based on ADC histograms can be an objective method. • Combination of DWI and pCASL or DSC-PWI can improve grading accuracy.

[Evaluation of association of myocardial bridge in the left anterior descending coronary with coronary atherosclerosis (stenosis > 50%) in the segment proximal to the site of bridge on coronary cta in hypertension subjects].

OBJECTIVE: To investigate whether myocardial bridging (MB) is an independent risk factor for coronary atherosclerosis (stenosis > 50%) proximal to MB in the left anterior descending coronary artery (LAD) in subjects with hypertension identified by coronary computed tomography angiography (CCTA). METHODS: From March 2011 to December 2012, Patients with suspected coronary disease underwent CCTA using dual-source CT scanner. The baseline clinical characteristics (age, gender, smoking history, presence of hypertension, dyslipidemia, diabetes mellitus, family history of heart attack and body mass index (BMI) ) and the results of CCTA were reviewed. Two radiologists evaluated the MB and more than 50% coronary atherosclerosis stenosis (CAS) in LAD and made a diagnosis by consensus. Significant independent risk factors for more than 50% CAS were investigated by Logistic regression analysis. All tests were two-tailed, the significance threshold was P value less than 0.05. RESULTS: The study included 9 862 patients, including 5 292 cases of patients with hypertension (MB in LAD 2 139 cases, more than 50% CAS proximal to MB 1 240 cases; no MB in 3 153 cases, more than 50% CAS in counterpart segment proximal to MB 898 cases); 4 570 cases of non-hypertensive patients (MB in LAD 1 043 cases, more than 50% CAS proximal to MB 418; no MB 3 527 cases, more than 50% CAS in counterpart segment proximal to MB 803 cases). After adjusted for clinical data, Logistic regression analysis showed that MB in LAD were significantly associated with CAS proximal to MB in LAD in hypertension and no hypertension subjects (OR, 3.17, 2.02, respectively, P < 0.05). CONCLUSION: MB in the LAD is an independent risk factor for more than 50% CAS in the proximal LAD in subjects with or without hypertension, and the OR of MB in subjects with hypertension is higher than that of MB in subjects without hypertension.

[Association of myocardial bridge of the left anterior descending coronary artery with coronary atherosclerotic stenosis in the segment proximal to the site of bridge].

OBJECTIVE: To investigate whether myocardial bridging (MB) is independently associated with coronary atherosclerosis proximal to MB in the left anterior descending coronary artery (LAD) identified by computed tomographic coronary angiography (CCTA). METHODS: From March 2011 to December 2012, patients (n=9 862) with suspected coronary disease underwent CCTA using dual-source CT scanner. The baseline clinical characteristics (age, gender, smoking history, presence of hypertension, dyslipidemia, diabetes mellitus, family history of heart attack, and body mass index) and the results of CCTA were reviewed. Two radiologists evaluated the coronary artery for MB and coronary atherosclerosis stenosis (CAS) in LAD and made a diagnosis by consensus. Significant independent risk factors for CAS were investigated by multivariate logistic regression analysis. RESULTS: A total of 3 182 (32.3%) cases of MB and 3 359 cases of CAS of LAD were identified. No patient with CAS in the tunneled segment was found. The mean length of bridges and the mean thickness of the overlying myocardium was (17.3±5.2) mm and (1.2±0.9) mm, respectively. There were 1658 MB cases in 3 359 cases of LAD stenosis and 1 524 MB cases in 6 503 cases of no LAD stenosis (χ(2)=681.12, P<0.05). Logistic regression analysis showed that MB in the LAD were significantly associated with CAS in the proximal LAD (OR=3.07, 95%CI=2.81-3.37, P<0.001), and after final adjustment for age, gender, body mass index, family history of heart attack, smoking, hypertension, dyslipidemia, diabetes mellitus, and resting heart rate (OR=2.86, 95% CI=2.60-3.16, P < 0.001). CONCLUSION: MB in the LAD is independently associated with CAS in the proximal segment to MB.

[Differentiation between glioma recurrence and radiation-induced brain injuries using perfusion-weighted magnetic resonance imaging].

OBJECTIVE: To evaluate the role of perfusion weighted imaging (PWI) in the differentiation between recurrent glioma and radiation-induced brain injuries. METHODS: Twenty-three patients with previously resected and irradiated glioma, presenting newly developed abnormal enhancement, were included in the study. The final diagnosis was determined either histologically or clinicoradiologically. PWI was obtained with a gradient echo echo-planar-imaging (GRE-EPI)technique. The normalized relative cerebral blood volume (rCBV) ratio [rCBV (abnormal enhancement)/rCBV (contralateral tissue)], relative cerebral blood flow (rCBF) ratio [rCBF (abnormal enhancement)/rCBF(contralateral tissue)], mean transit time(MTT) ratio [MTT (abnormal enhancement)/MTT(contralateral tissue)],time to peak(TTP)ratio[TTP(abnormal enhancement)/TTP(contralateral tissue)],and bolus arrive time(BAT)ratio[BAT(abnormal enhancement)/BAT(contralateral tissue)] were calculated. The regions of interest (ROIs) consisting of 20-40mm(2) were placed in the abnormal enhanced areas on postcontrast T1-weighted images.Ten ROIs measurements were performed in each lesion.T test was used to determine whether there was a difference in the rCBV/rCBF/rMTT/rTTP/rBAT ratios between recurrent glioma and irradiated injuries.Significance was set to a P value <0.05. RESULTS: Thirteen of the 23 patients were proved recurrent glioma and 10 were proved radiation-induced brain injuries. The rCBV ratio (3.60±3.86 vs. 0.82 ± 0.74, P = 0.000)and rCBF ratio (2.88 ± 2.27 vs. 0.84 ± 0.80, P = 0.000) in glioma recurrence were markedly higher than those in radiation injuries. The areas under rCBV and rCBF ROC curve were both 0.8763. rMTT (P=0.204), rTTP (P=0.260), and rBAT (P=0.071) ratios showed no statistical difference between the two groups. CONCLUSION: PWI is an effective technique in distinguishing glioma recurrence from radiation injuries,and the ratios of rCBV and rCBF ratio differential diagnosis of critical value to 1.3088 and 1.1235, respectively, can be used as a reliable clinical indicator.

Carryover Contamination-Controlled Amplicon Sequencing Workflow for Accurate Qualitative and Quantitative Detection of Pathogens: a Case Study on SARS-CoV-2.

Carryover contamination during amplicon sequencing workflow (AMP-Seq) put the accuracy of the high-throughput detection for pathogens at risk. The purpose of this study is to develop a carryover contaminations-controlled AMP-Seq (ccAMP-Seq) workflow to enable accurate qualitative and quantitative detection for pathogens. By using the AMP-Seq workflow to detect SARS-CoV-2, Aerosols, reagents and pipettes were identified as potential sources of contaminations and ccAMP-Seq was then developed. ccAMP-Seq used filter tips and physically isolation of experimental steps to avoid cross contamination, synthetic DNA spike-ins to compete with contaminations and quantify SARS-CoV-2, dUTP/uracil DNA glycosylase system to digest the carryover contaminations, and a new data analysis procedure to remove the sequencing reads from contaminations. Compared to AMP-Seq, the contamination level of ccAMP-Seq was at least 22-folds lower and the detection limit was also about an order of magnitude lower-as low as one copy/reaction. By testing the dilution series of SARS-CoV-2 nucleic acid standard, ccAMP-Seq showed 100% sensitivity and specificity. The high sensitivity of ccAMP-Seq was further confirmed by the detection of SARS-CoV-2 from 62 clinical samples. The consistency between qPCR and ccAMP-Seq was 100% for all the 53 qPCR-positive clinical samples. Seven qPCR-negative clinical samples were found to be positive by ccAMP-Seq, which was confirmed by extra qPCR tests on subsequent samples from the same patients. This study presents a carryover contamination-controlled, accurate qualitative and quantitative amplicon sequencing workflow that addresses the critical problem of pathogen detection for infectious diseases. IMPORTANCE Accuracy, a key indicator of pathogen detection technology, is compromised by carryover contamination in the amplicon sequencing workflow. Taking the detection of SARS-CoV-2 as case, this study presents a new carryover contamination-controlled amplicon sequencing workflow. The new workflow significantly reduces the degree of contamination in the workflow, thereby significantly improving the accuracy and sensitivity of the SARS-CoV-2 detection and empowering the ability of quantitative detection. More importantly, the use of the new workflow is simple and economical. Therefore, the results of this study can be easily applied to other microorganism, which has great significance for improving the detection level of microorganism.

Perfusion magnetic resonance imaging in the differentiation between glioma recurrence and pseudoprogression: a systematic review, meta-analysis and meta-regression.

Background: Tumor recurrence and pseudoprogression (PsP) have similar imaging manifestations in conventional magnetic resonance imaging (MRI), although the subsequent treatments are completely different. This study aimed to evaluate the value of perfusion-weighted imaging (PWI) in differentiating PsP from glioma recurrence. Methods: A comprehensive literature search was performed to evaluate clinical studies focused on differentiating recurrent glioma from PsP using PWI, including dynamic susceptibility contrast MRI (DSC-MRI), dynamic contrast enhanced MRI (DCE-MRI), and arterial spin labeling (ASL). Study selection and data extraction were independently completed by two reviewers. The Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool was applied to evaluate the quality of the included studies. The software Stata 16.0 and Meta-Disc 1.4 were used for the meta-analysis. Meta-regression and subgroup analyses were applied to identify the sources of heterogeneity in the studies. This study was registered in the International Prospective Register of Systematic Reviews (PROSPERO) prior to initiation (CRD42022304404). Results: A total of 40 studies were included, including 27 English studies and 13 Chinese studies. There were 1,341 patients with glioma recurrence and 876 patients with PsP. The pooled sensitivity and specificity of DSC-MRI for differentiating glioma recurrence from PsP were 0.82 [95% confidence interval (CI): 0.78 to 0.86] and 0.87 (95% CI: 0.80 to 0.92), respectively. The pooled sensitivity and specificity of DCE-MRI were 0.83 (95% CI: 0.76 to 0.89) and 0.83 (95% CI: 0.78 to 0.87), respectively. The pooled sensitivity and specificity of ASL were 0.80 (95% CI: 0.73 to 0.86) and 0.86 (95% CI: 0.76 to 0.92), respectively. Discussion: The DSC-MRI, DCE-MRI, and ASL perfusion techniques displayed high accuracy in distinguishing glioma recurrence from PsP, and DSC-MRI had a higher diagnostic performance than the other two techniques. However, due to the diversity of the parameters and threshold differences, further investigation and standardization are needed.

Quantitative susceptibility-weighted imaging in amyotrophic lateral sclerosis with 3.0 T magnetic resonance imaging.

OBJECTIVE: To evaluate alterations in phase-shift values in the gray matter of patients with amyotrophic lateral sclerosis (ALS) using susceptibility-weighted imaging (SWI). METHODS: Twenty patients with definite or probable ALS and 19 age- and sex-matched healthy controls were enrolled. SWI was performed using a 3.0 T magnetic resonance imaging scanner. Phase-shift values were measured in corrected phase images using regions of interest, which were placed on the bilateral precentral gyrus, frontal cortex, caudate nucleus, globus pallidus, and putamen. RESULTS: Phase-shift values of the precentral gyrus were significantly lower in ALS patients (-0.176 ± 0.050) than in the control group (-0.119 ± 0.016) on SWI. The average phase-shift values of the frontal cortex, caudate nucleus, globus pallidus, and putamen in ALS patients (-0.089 ± 0.023, -0.065 ± 0.016, -0.336 ± 0.191, and -0.227 ± 0.101, respectively) were not significantly different from those in the healthy controls (-0.885 ± 0.015, -0.079 ± 0.018, -0.329 ± 0.136, and -0.229 ± 0.083, respectively). CONCLUSIONS: Compared with healthy controls, ALS patients had a lower phase-shift value in the precentral gyrus, which may be related to abnormal iron overload. Thus, SWI is a potential method for identifying ALS patients.

Predictive Role of the Apparent Diffusion Coefficient and MRI Morphologic Features on IDH Status in Patients With Diffuse Glioma: A Retrospective Cross-Sectional Study.

PURPOSE: To evaluate isocitrate dehydrogenase (IDH) status in clinically diagnosed grade II~IV glioma patients using the 2016 World Health Organization (WHO) classification based on MRI parameters. MATERIALS AND METHODS: One hundred and seventy-six patients with confirmed WHO grade II~IV glioma were retrospectively investigated as the study set, including lower-grade glioma (WHO grade II, n = 64; WHO grade III, n = 38) and glioblastoma (WHO grade IV, n = 74). The minimum apparent diffusion coefficient (ADCmin) in the tumor and the contralateral normal-appearing white matter (ADCn) and the rADC (ADCmin to ADCn ratio) were defined and calculated. Intraclass correlation coefficient (ICC) analysis was carried out to evaluate interobserver and intraobserver agreement for the ADC measurements. Interobserver agreement for the morphologic categories was evaluated by Cohen's kappa analysis. The nonparametric Kruskal-Wallis test was used to determine whether the ADC measurements and glioma subtypes were related. By univariable analysis, if the differences in a variable were significant (P<0.05) or an image feature had high consistency (ICC >0.8; κ >0.6), then it was chosen as a predictor variable. The performance of the area under the receiver operating characteristic curve (AUC) was evaluated using several machine learning models, including logistic regression, support vector machine, Naive Bayes and Ensemble. Five evaluation indicators were adopted to compare the models. The optimal model was developed as the final model to predict IDH status in 40 patients with glioma as the subsequent test set. DeLong analysis was used to compare significant differences in the AUCs. RESULTS: In the study set, six measured variables (rADC, age, enhancement, calcification, hemorrhage, and cystic change) were selected for the machine learning model. Logistic regression had better performance than other models. Two predictive models, model 1 (including all predictor variables) and model 2 (excluding calcification), correctly classified IDH status with an AUC of 0.897 and 0.890, respectively. The test set performed equally well in prediction, indicating the effectiveness of the trained classifier. The subgroup analysis revealed that the model predicted IDH status of LGG and GBM with accuracy of 84.3% (AUC = 0.873) and 85.1% (AUC = 0.862) in the study set, and with the accuracy of 70.0% (AUC = 0.762) and 70.0% (AUC = 0.833) in the test set, respectively. CONCLUSION: Through the use of machine-learning algorithms, the accurate prediction of IDH-mutant versus IDH-wildtype was achieved for adult diffuse gliomas via noninvasive MR imaging characteristics, including ADC values and tumor morphologic features, which are considered widely available in most clinical workstations.

GmoDetector: An accurate and efficient GMO identification approach and its applications.

The rapid increase of genetically modified organisms (GMOs) entering the food and feed markets, and the contamination of donor (micro)organisms of transgenic elements make it more challenging for the existing GMO detection. In this study, we developed a high-throughput and contamination-removal GMO detection approach named as GmoDetector. GmoDetector targeted 64 common transgenic elements and 76 GMO-specific events collected from 251 singular GM events, and combined with next generation sequencing (NGS) and target enrichment technology to detect various GMOs. As a result, GmoDetector was able to exclude the donor (micro)organism contamination, and detect the authorized and unauthorized GMOs (UGMOs) in any forms of food or feed, such as processed or unprocessed. The sensitivity of GmoDetector is as low as 0.1% (GMO content), which has met the GMO labeling threshold for all countries. Therefore, GmoDetector is a robust tool for accurate and efficient detection of the authorized and UGMOs.

Differentiation between radiation-induced brain injury and glioma recurrence using 3D pCASL and dynamic susceptibility contrast-enhanced perfusion-weighted imaging.

PURPOSE: This study was performed to validate the efficacy of three-dimensional pseudocontinuous arterial spin labeling (pCASL) compared with dynamic susceptibility contrast-enhanced perfusion-weighted imaging (DSC-PWI) in distinguishing radiation-induced brain injury from glioma recurrence in patients with glioma. METHODS: Both 3D pCASL and DSC-PWI were performed using a 3.0 Tesla scanner in 69 patients with previously resected and irradiated glioma who displayed newly developed abnormal contrast-enhanced lesions. The included patients were classified into a radiation-induced brain injury group (n = 34) and a glioma recurrence group (n = 35) based on subsequent pathologic analysis or clinical-radiological follow-up. Lesion perfusion parameter values (CBF and nCBF on pCASL, nrCBV and nrCBF on DSC-PWI) were measured and compared between the two groups using Student's t test. Pearson correlation analysis was performed to evaluate the correlation between pCASL (CBF and nCBF) and DSC-PWI (nrCBV and nrCBF) values in the contrast-enhanced lesions and in the perifocal edema regions. RESULTS: For the contrast-enhanced lesions, the CBF, nCBF, nrCBV, and nrCBF (29.46 ±â€¯15.08 ml/100 g/min, 1.11 ±â€¯0.50, 1.39 ±â€¯1.15, and 1.30 ±â€¯0.74) in the radiation-induced brain injury group were significantly lower than those (64.52 ±â€¯33.92 ml/100 g/min, 2.73 ±â€¯1.71, 3.39 ±â€¯2.12, and 3.20 ±â€¯1.95) in the glioma recurrence group (P < 0.001). The CBF and nCBF demonstrated strong correlation with nrCBV and nrCBF in the contrast-enhanced lesions. CONCLUSION: Radiation-induced brain injury and glioma recurrence can be reliably distinguished using both 3D pCASL and DSC-PWI. Contrast-free 3D pCASL is a suitable alternative to DSC-PWI for long-term follow-up in glioma patients with postoperative radiotherapy.

T2 relaxation time measurements in the brains of scalded rats.

This study aimed to evaluate the T2 relaxation time of the brain in severely scalded rats using a magnetic resonance (MR) T2 mapping sequence, and to investigate the correlation between T2 relaxation time and plasma glucose level. Twenty-eight Wistar rats were randomly divided into the scalded group (n=21) and control group (n=7). Magnetic resonance scans were performed with T1WI, T2WI, and T2-mapping sequences in the scalded group; the scans were performed 1 day prior to scalding and 1, 3, 5, and 7 days post-scalding; in addition, identical MR scans were performed in the control group at the same time points. T2-maps were generated and T2 relaxation times were acquired from the following brain regions: the hippocampus, thalamus, caudate-putamen, and cerebrum. Pathological changes of the hippocampus were observed. The plasma glucose level of each rat was measured before each MR scan, and a correlation analysis was performed between T2 relaxation time and plasma glucose level. We found that conventional T1WI and T2WI did not reveal any abnormal signals or morphological changes in the hippocampus, thalamus, caudate-putamen, or cerebrum post-scalding. Both the T2 relaxation times of the selected brain regions and plasma glucose levels increased 1, 3, and 5 days post-scalding, and returned to normal levels 7 days post-scalding. The most marked increase of T2 relaxation time was found in the hippocampus; similar changes were also revealed in the thalamus, caudate-putamen, and cerebrum. No correlation was found between T2 relaxation time and plasma glucose level in scalded rats. Pathological observation of the hippocampus showed edema 1, 3, and 5 days post-scalding, with recovery to normal findings at 7 days post-scalding. Thus, we concluded that T2 mapping is a sensitive method for detecting and monitoring scald injury in the rat brain. As the hippocampus is the main region for modulating a stress reaction, it showed significantly increased water content along with an increased plasma glucose level post-scalding.

Investigation on interaction between Ligupurpuroside A and pepsin by spectroscopic and docking methods.

Ligupurpuroside A is one of the major glycoside in Ku-Din-Cha, a type of Chinese functional tea. In order to better understand its digestion and metabolism in humans, the interaction between Ligupurpuroside A and pepsin has been investigated by fluorescence spectra, UV-vis absorption spectra and synchronous fluorescence spectra along with molecular docking method. The fluorescence experiments indicate that Ligupurpuroside A can effectively quench the intrinsic fluorescence of pepsin through a combined quenching way at the low concentration of Ligupurpuroside A, and a static quenching procedure at the high concentration. The binding constant, binding sites of Ligupurpuroside A with pepsin have been calculated. The thermodynamic analysis suggests that non-covalent reactions, including electrostatic force, hydrophobic interaction and hydrogen bond are the main forces stabilizing the complex. According to the Förster's non-radiation energy transfer theory, the binding distance between pepsin and Ligupurpuroside A was calculated to be 3.15 nm, which implies that energy transfer occurs between pepsin and Ligupurpuroside A. Conformation change of pepsin was observed from UV-vis absorption spectra and synchronous fluorescence spectra under experimental conditions. In addition, all these experimental results have been validated by the protein-ligand docking studies which show that Ligupurpuroside A is located in the cleft between the domains of pepsin.

[Association of myocardial bridge in the left anterior descending coronary with coronary atherosclerosis proximal to the bridge site in diabetic patients].

OBJECTIVE: To investigate whether myocardial bridging (MB) is an independent risk factor for coronary atherosclerosis proximal to the bridge site in the left anterior descending coronary artery (LAD) in diabetic patients. METHODS: From March 2011 to December 2012, 9862 patients with suspected coronary disease underwent coronary computed tomography angiography (CCTA) using a dual-source CT scanner. The baseline clinical characteristics (age, gender, smoking history, presence of hypertension, dyslipidemia, diabetes mellitus, family history of heart attack and body mass index) and the results of CCTA were reviewed. Two radiologists evaluated the MB and coronary atherosclerosis stenosis (CAS) over 50% in the LAD and made a diagnosis by consensus. Significant independent risk factors for CAS were investigated by logistic regression analysis. RESULTS: Of the 2345 patients identified to have diabetes mellitus, 1373 had MB, among whom 827 had coronary atherosclerosis proximal to the bridge site; 972 of the diabetic patients were free of MB, among whom 254 had coronary atherosclerosis at the equivalent site. None of the patients had CAS in the tunneled segment. After adjusted for clinical data, logistic regression analysis showed that MB in the LAD was significantly correlated with coronary atherosclerosis in the proximal LAD in diabetic patient (OR=3.91) and non-diabetic patients (OR=2.69) (P<0.05). CONCLUSION: In diabetic patients, atherosclerosis occurred frequently in the segment proximal to MB in the LAD, and MB in the mid-LAD is an independent risk factor for CAS in the proximal LAD.

The role of magnetic resonance diffusion-weighted imaging and three-dimensional arterial spin labelling perfusion imaging in the differentiation of parasellar meningioma and cavernous haemangioma.

OBJECTIVE: To evaluate the diagnostic value of magnetic resonance diffusion-weighted imaging (DWI) and three-dimensional arterial spin labelling perfusion imaging (3D-ASL) in distinguishing cavernous haemangioma from parasellar meningioma, using histological data as a reference standard. METHODS: Patients with parasellar meningioma or parasellar cavernous haemangioma underwent conventional T1- and T2-weighted magnetic resonance imaging (MRI) followed by DWI and 3D-ASL using a 3.0 Tesla MRI. The minimum apparent diffusion coefficient (minADC) from DWI and the maximal normalized cerebral blood flow (nCBF) from 3D-ASL were measured in each tumour. Diagnosis was confirmed by histology. RESULTS: MinADC was significantly lower and nCBF significantly higher in meningioma (n = 19) than cavernous haemangioma (n = 15). There was a significant negative correlation between minADC and nCBF (r = -0.605). CONCLUSION: DWI and 3D-ASL are useful in differentiating cavernous haemangiomas from parasellar meningiomas, particularly in situations when the appearance on conventional MRI sequences is otherwise ambiguous.