Differentiation of confluent hepatic fibrosis and infiltrative hepatocellular carcinoma on MR imaging.

BACKGROUND: To identify reliable magnetic resonance imaging (MRI) features that can differentiate confluent fibrosis (CF) from infiltrative hepatocellular carcinoma (HCC). METHODS: A retrospective analysis was conducted on Twenty CF patients and 28 infiltrative HCC patients who underwent upper abdomen MRI scans. The imaging features of lesions were analyzed, and the apparent diffusion coefficient (ADC) of lesions were measured. Accuracy, sensitivity and specificity for the diagnosis of CF were calculated for each category individually and combined. RESULTS: Compared to infiltrative HCC, hepatic capsular retraction at the site of lesion, hepatic volume loss at the site of lesion and "nodular surround sign" were more common in patients with CF (all P < 0.001). Hepatic volume loss at the site of lesion, no or mild enhancement in arterial phase, and hyper-enhancing in delayed phase to the background parenchyma showed superior diagnostic accuracy (83.3%, 85.4%, 97.9%, respectively). When the lesion exhibited hepatic volume loss at the site of lesion or no or mild enhancement in arterial phase or hyper-enhancing in delayed phase, a sensitivity of 100.0% for the diagnosis of CF was achieved. When the lesion was positive for any two of three categories, or positive for all three categories, a specificity of 100.0% was achieved. The ADC values of CF were higher than those of infiltrative HCC (P < 0.001). CONCLUSION: The combination of the hepatic volume loss at the site of lesion, no or mild enhancement in arterial phase, and hyper-enhancing in delayed phase to the background parenchyma can be considered reliable MR features for the diagnosis of CF, as they allow differentiation from infiltrative HCC.

Circularly Polarized Organic Ultralong Room-Temperature Phosphorescence with A High Dissymmetry Factor in Chiral Helical Superstructures.

Long-lived room-temperature phosphorescence (RTP) of organic materials holds a significant potential for optical information. Circularly polarized organic ultralong room-temperature phosphorescence (CP-OURTP) with extremely high dissymmetry factor (glum ) values is even highly demanded and considerably challenging. Here, an effective strategy is introduced to realize CP-OURTP with an emission decay time of 735 ms and a glum value up to 1.49, which exceeds two orders of magnitude larger than previous records, through a system composed of RTP polymers and chiral helical superstructures. The system exhibits excellent stability under multiple cycles of photoirradiation and thermal treatment, and is further employed for information encryption based on optical multiplexing. The results are anticipated to lay the foundation for the development of CP-OURTP materials in advanced photonic applications.

Changes in coagulation markers in children with Mycoplasma pneumoniae pneumonia and their predictive value for Mycoplasma severity.

BACKGROUND: This study investigates the correlation between coagulation levels and the severity of Mycoplasma pneumoniae pneumonia (MPP) in children. In addition, the study analyses the predictive value of coagulation abnormalities in MPP combined with necrotising pneumonia (NP). METHODS: A total of 170 children with MPP who underwent treatment between June 2021 and February 2022 were selected for this study. The study population was divided into groups according to the severity of the disease to compare differences in the incidence of coagulation abnormalities between the groups. The participants were also divided into groups according to imaging manifestations to compare the differences in coagulation function among the different groups. All data information was processed for statistical analysis using SPSS Statistics 25.0 and GraphPad Prism 7.0 statistical analysis software. RESULTS: The incidence of coagulation abnormalities in the children in the severe MPP (SMPP) group was significantly higher than that in the normal MPP (NMPP) group (P < 0.05). The multi-factor logistic regression analysis revealed that the D-dimer level is an independent risk factor for the development of NP in SMPP (P < 0.05). The receiver operating characteristic curve analysis revealed statistically significant differences (P < 0.05) in D-dimer, fibrinogen degeneration products (FDP), neutrophils, lactate dehydrogenase and serum ferritin for predicting SMPP combined with NP. Bronchoscopic manifestations of coagulation indicators (D-dimer and FDP levels) were significantly higher in the mucus plug group than in the non-mucus plug group, while the activated partial thromboplastin time levels were lower in the former than in the latter (P < 0.05). CONCLUSION: The degree of elevated D-dimer and FDP levels was positively correlated with the severity of MPP, with elevated serum D-dimer levels (> 3.705 mg/L) serving as an independent predictor of MPP combined with NP in children.

Correlation between Mycoplasma pneumoniae drug resistance and clinical characteristics in bronchoalveolar lavage fluid of children with refractory Mycoplasma pneumoniae pneumonia.

BACKGROUND: To investigate the resistance-gene mutation of Mycoplasma pneumoniae (MP) in the bronchoalveolar lavage fluid of children with Mycoplasma pneumoniae pneumonia (MPP) and the clinical characteristics of refractory Mycoplasma pneumoniae pneumonia (RMPP) correlation. METHODS: Forty-eight children with MPP were selected and placed in RMPP and non-RMPP groups based on their clinical status - whether they had worsening clinical symptoms, persistent fever and a worsening lung image. They were also separated into drug-resistance gene mutation and non-mutated groups using nucleic acid detection. The participants' data were collected on high-sensitivity C-reactive protein and MP-DNA loads, fever time, hospitalisation time, macrolide antibiotic application time and fever regression time after application. The differences in imaging manifestations were determined by using multivariate logistic regression to analyse the clinical characteristics of RMPP. Additionally, the correlation between drug-resistance gene mutations and the clinical characteristics of RMPP was summarised. RESULTS: Among the 48 MPP children, 31 (64.6%) had A2063G and/or A2064G gene mutation, 31 (64.6%) had RMPP and 23 (74.2%) had drug-resistance gene mutation. The children in the drug-resistance gene mutation group had higher high-sensitivity C-reactive protein and MP-DNA loads, longer fever time, hospitalisation time, macrolide antibiotic application time, fever regression time after application and extrapulmonary complications. There were more symptoms and more severe changes under bronchoscopy. The difference was statistically significant (P < 0.05). Logistic multivariate regression analysis showed that the mutation of drug-resistance genes had no significant correlation with RMPP. CONCLUSION: The mutation rate of drug-resistance genes in children with MPP is high, the inflammatory index and MP-DNA load are high, the course of the disease is long, and the changes under bronchoscopy are severe. The occurrence of RMPP is not only determined by drug-resistance genes but may also be the result of a combination of factors.

R2* value derived from multi-echo Dixon technique can aid discrimination between benign and malignant focal liver lesions.

BACKGROUND: R2* estimation reflects the paramagnetism of the tumor tissue, which may be used to differentiate between benign and malignant liver lesions when contrast agents are contraindicated. AIM: To investigate whether R2* derived from multi-echo Dixon imaging can aid differentiating benign from malignant focal liver lesions (FLLs) and the impact of 2D region of interest (2D-ROI) and volume of interest (VOI) on the outcomes. METHODS: We retrospectively enrolled 73 patients with 108 benign or malignant FLLs. All patients underwent conventional abdominal magnetic resonance imaging and multi-echo Dixon imaging. Two radiologists independently measured the mean R2* values of lesions using 2D-ROI and VOI approaches. The Bland-Altman plot was used to determine the interobserver agreement between R2* measurements. Intraclass correlation coefficient (ICC) was used to determine the reliability between the two readers. Mean R2* values were compared between benign and malignant FFLs using the nonparametric Mann-Whitney test. Receiver operating characteristic curve analysis was used to determine the diagnostic performance of R2* in differentiation between benign and malignant FFLs. We compared the diagnostic performance of R2* measured by 2D-ROI and VOI approaches. RESULTS: This study included 30 benign and 78 malignant FLLs. The interobserver reproducibility of R2* measurements was excellent for the 2D-ROI (ICC = 0.994) and VOI (ICC = 0.998) methods. Bland-Altman analysis also demonstrated excellent agreement. Mean R2* was significantly higher for malignant than benign FFLs as measured by 2D-ROI (P < 0.001) and VOI (P < 0.001). The area under the curve (AUC) of R2* measured by 2D-ROI was 0.884 at a cut-off of 25.2/s, with a sensitivity of 84.6% and specificity of 80.0% for differentiating benign from malignant FFLs. R2* measured by VOI yielded an AUC of 0.875 at a cut-off of 26.7/s in distinguishing benign from malignant FFLs, with a sensitivity of 85.9% and specificity of 76.7%. The AUCs of R2* were not significantly different between the 2D-ROI and VOI methods. CONCLUSION: R2* derived from multi-echo Dixon imaging whether by 2D-ROI or VOI can aid in differentiation between benign and malignant FLLs.

Liver fat accumulation measured by high-speed T2-corrected multi-echo magnetic resonance spectroscopy can predict risk of cholelithiasis.

BACKGROUND: Liver fat accumulation is associated with increased cholesterol synthesis and hypersecretion of biliary cholesterol, which may be related to the development of cholelithiasis. AIM: To investigate whether liver fat accumulation measured by high-speed T2-corrected multi-echo magnetic resonance spectroscopy (MRS) is a risk factor for cholelithiasis. METHODS: Forty patients with cholelithiasis and thirty-one healthy controls were retrospectively enrolled. The participants underwent high-speed T2-corrected multi-echo single-voxel MRS of the liver at a 3T MR scanner. The proton density fat fraction (PDFF) and R2 value were calculated. Serum parameters and waist circumference (WC) were recorded. Spearman's correlation analysis was used to analyze the relationship between PDFF, R2, and WC values. Multivariate logistic regression analysis was carried out to determine the significant predictors of the risk of cholelithiasis. Receiver operating characteristic curve (ROC) analysis was used to evaluate the discriminative performance of significant predictors. RESULTS: Patients with cholelithiasis had higher PDFF, R2, and WC values compared with healthy controls (5.8% ± 4.2% vs 3.3% ± 2.4%, P = 0.001; 50.4 ± 24.8/s vs 38.3 ± 8.8/s, P = 0.034; 85.3 ± 9.0 cm vs 81.0 ± 6.9 cm, P = 0.030; respectively). Liver iron concentration extrapolated from R2 values was significantly higher in the cholelithiasis group (2.21 ± 2.17 mg/g dry tissue vs 1.22 ± 0.49 mg/g dry tissue, P = 0.034) than in the healthy group. PDFF was positively correlated with WC (r = 0.502, P < 0.001) and R2 (r = 0.425, P < 0.001). Multivariate logistic regression analysis showed that only PDFF was an independent risk factor for cholelithiasis (odds ratio = 1.79, 95%CI: 1.22-2.62, P = 0.003). ROC analysis showed that the area under the curve of PDFF was 0.723 for discriminating cholelithiasis from healthy controls, with a sensitivity of 55.0% and specificity of 83.9% when the cut-off value of PDFF was 4.4%. CONCLUSION: PDFF derived from high speed T2-corrected multi-echo MRS can predict the risk of cholelithiasis.

DSC and DCE Histogram Analyses of Glioma Biomarkers, Including IDH, MGMT, and TERT, on Differentiation and Survival.

RATIONALE AND OBJECTIVES: The World Health Organization 2016 classification of central nervous system tumors added the molecular classification of gliomas and has guiding significance for the operation and prognosis of glioma patients. At present, the perfusion technique plays an important role in judging the malignant degree of glioma. To evaluate the performance of dynamic susceptibility contrast (DSC)- and dynamic contrast-enhanced (DCE)-magnetic resonance imaging (MRI) histogram analyses in discriminating the states of molecular biomarkers and survival in glioma patients. MATERIALS AND METHODS: Forty-three glioma patients who underwent DCE- and DSC-MRI were enrolled. Relevant molecular test results, including those on isocitrate dehydrogenase (IDH), O6-methylguanine-DNA methyltransferase (MGMT) and telomere reverse transcriptase (TERT), were collected. The mean relative cerebral blood volume of DSC-MRI and histogram parameters derived from DCE-MRI (volume transfer coefficient (Ktrans), fractional volume of the extravascular extracellular space (Ve), fractional blood plasma volume (Vp), rate constant between the extravascular extracellular space and blood plasma (Kep) and area under the curve (AUC)) were calculated. Differences in each parameter between gliomas with different expression states (IDH, MGMT, and TERT) were evaluated. The diagnostic efficiency of each parameter was analyzed. The overall survival of all patients was assessed. RESULTS: The 10th percentile AUC (AUC = 0.830, sensitivity = 0.78, specificity = 0.80), the 90th percentile Ve (AUC = 0.816, sensitivity = 0.84, specificity = 0.79), and the mean Kep (AUC = 0.818, sensitivity = 0.76, specificity = 0.78) provided the highest differential efficiency for IDH, MGMT, and TERT, respectively. Kaplan-Meier curves showed a significant difference between subjects with a 10th percentile AUC higher or lower than 0.028 (log-rank = 7.535; p = 0.006) for IDH and between subjects with different 90th percentile Ve values (log-rank = 6.532; p = 0.011) for MGMT. CONCLUSION: Histogram DCE-MRI demonstrates good diagnostic performance in identifying different molecular types and for the prognostic assessment of glioma.

Differential diagnosis of central lymphoma and high-grade glioma: dynamic contrast-enhanced histogram.

BACKGROUND: In clinical diagnosis, some central nervous system lymphomas (CNSL) are difficult to distinguish from high-grade gliomas (HGG). PURPOSE: To evaluate the diagnostic efficacy of the histogram analysis of dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) in the identification of CNSL and HGG. MATERIAL AND METHODS: In all, 43 patients diagnosed with HGG (n = 28) and CNSL (n = 15) by histopathology underwent DCE-MRI scanning. Differences in histogram parameters based on DCE-MRI between HGG and CNSL were analyzed by Mann-Whitney U test. In addition, receiver operating characteristic (ROC) analysis was performed. Short-term follow-up of patients was performed using Kaplan-Meier analysis to explore the survival rates of HGG and CNSL. RESULTS: For the ROC curve analysis, we demonstrate that the 10th percentile of Ktrans (area under the curve [AUC] = 0.912, sensitivity = 86.7%, specificity = 92.9%), Kep (AUC = 0.940, sensitivity = 93.3%, specificity = 79.6%), Ve (AUC = 0.907, sensitivity = 86.7%, specificity = 89.3%), and AUC (AUC = 0.904, sensitivity = 86.7%, specificity = 92.9%) were significantly different between the CNSL and HGG groups (P < 0.001), with high diagnostic efficiency. Table 2 shows that the histogram features based on AUC maps (10th, 25th, median, 75th, 90th, and mean) were always significantly higher in the CNSL group than in the HGG group (P < 0.001). There was no significant difference in Vp or in the 75th, 90th and mean of Ktrans, Kep, and Ve between the CNSL and HGG groups (P > 0.05). CONCLUSION: A histogram analysis of DCE-MRI identified significant differences between HGG and CNSL, and this will help in the clinical differential diagnosis of these conditions.

Relationship between intracranial pressure and phase-contrast cine MRI-derived measures of cerebrospinal fluid parameters in communicating hydrocephalus.

BACKGROUND: To explore the correlation between intracranial pressure (ICP) and cerebrospinal fluid (CSF) parameters assessed by phase-contrast cine MRI (PC-MRI). METHODS: Fifteen normal people and 80 subjects with communicating hydrocephalus who underwent PC-MRI examinations from a single center were included in this cross-sectional study. In addition to recording patient's age, heart rate, blood pressure and body mass index (BMI), ICP and CSF hemodynamic parameters, such as flow velocity and aqueduct diameter, were measured for correlation analysis. RESULTS: The mean ICP and CSF aqueduct diameter in hydrocephalus patients were 151.05 mmH2O and 2.877 mm, respectively, and the maximum (6.938 cm/s) and mean (0.845 cm/s) CSF flow velocities were significantly higher in these patients compared with the controls (P<0.05). After adjusting for age, heart rate, blood pressure, and BMI, there was no significant relationship between peak velocity and ICP (P>0.05). Furthermore, a nonlinear relationship was observed between the ICP and the average velocity of CSF, and the ICP and aqueduct diameter. The ICP increased with the average velocity above 1.628 cm/s (P≤0.01), and the aqueduct diameter increased more than 3.6 mm (P<0.001). CONCLUSIONS: This study found significant correlations between ICP and average velocity and aqueduct diameter. These findings can be useful in assisting clinicians in predicting ICP more effectively, thus improving patient management.

Accuracy of multi-echo Dixon sequence in quantification of hepatic steatosis in Chinese children and adolescents.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is currently the outstanding cause of chronic liver disease in children and adolescents, especially in overweight and obese groups. Liver biopsy is the reference standard to diagnose NAFLD but invasive, thus it is not the best choice in clinical diagnosis and follow-up. Magnetic resonance (MR) is widely used in clinical trials to noninvasively quantify liver fat content in adults and children in foreign countries. While currently, it is rarely used in Chinese children and adolescents. We postulated that quantifying hepatic steatosis by MR could be extended to children and adolescents in China. AIM: To investigate the accuracy of MR imaging (MRI) in quantifying liver fat with MR spectroscopy (MRS) as a reference. A secondary goal was to assess the prevalence of NAFLD in overweight and obese Chinese children and adolescents. METHODS: There were 86 children and adolescents enrolled in this study, including 65 overweight and obese children and 21 healthy children. The participants underwent MRI and MRS. MRI and MRS were performed using multi-echo Dixon and HISTO sequences, respectively, to calculate hepatic proton density fat fraction (PDFF). Hepatic steatosis was diagnosed using MRS-PDFF > 5% as the threshold. Spearman's analysis was used to evaluate the correlation between MRI and MRS. The agreement between these two methods was assessed by Bland-Altman analysis. RESULTS: The MRI-PDFF in the MRS region of interest and the entire liver was 9.9% ± 10.3% with a range of 0.3%-39.9%, and 10.6% ± 9.4% with a range of 1.9%-38.9%, respectively. The MRS-PDFF was 9.1% ± 10.0%, with a range of 0.5%-37.8%. The incidence of hepatic steatosis detected by MRS-PDFF was 46.5% (40/86) of all participants, all of whom belonged to the overweight and obese group. Spearman's analysis indicated an excellent correlation between multi-echo Dixon and MRS (r > 0.9, P < 0.01). Bland-Altman analysis also demonstrated a good agreement between these two methods. CONCLUSION: Multi-echo Dixon shows an excellent correlation and agreement with MRS in quantifying liver fat content and could be a potential tool to detect hepatic steatosis in Chinese children and adolescents.

Mutational Mtc6p attenuates autophagy and improves secretory expression of heterologous proteins in Kluyveromyces marxianus.

BACKGROUND: The yeast Kluyveromyces marxianus is an emerging cell factory for heterologous protein biosynthesis and its use holds tremendous advantages for multiple applications. However, which genes influence the productivity of desired proteins in K. marxianus has so far been investigated by very few studies. RESULTS: In this study, we constructed a K. marxianus recombinant (FIM1/Est1E), which expressed the heterologous ruminal feruloyl esterase Est1E as reporter. UV-60Co-γ irradiation mutagenesis was performed on this recombinant, and one mutant (be termed as T1) was screened and reported, in which the productivity of heterologous Est1E was increased by at least tenfold compared to the parental FIM1/Est1E recombinant. Transcriptional perturbance was profiled and presented that the intracellular vesicle trafficking was enhanced while autophagy be weakened in the T1 mutant. Moreover, whole-genome sequencing combined with CRISPR/Cas9 mediated gene-editing identified a novel functional protein Mtc6p, which was prematurely terminated at Tyr251 by deletion of a single cytosine at 755 loci of its ORF in the T1 mutant. We found that deleting C755 of MTC6 in FIM1 led to 4.86-fold increase in the production of Est1E compared to FIM1, while the autophagy level decreased by 47%; on the contrary, when reinstating C755 of MTC6 in the T1 mutant, the production of Est1E decreased by 66% compared to T1, while the autophagy level increased by 124%. Additionally, in the recombinant with attenuated autophagy (i.e., FIM1 mtc6C755Δ and T1) or interdicted autophagy (i.e., FIM1 atg1Δ and T1 atg1Δ), the productivity of three other heterologous proteins was also increased, specifically the heterologous mannase Man330, the ß-1,4-endoxylanase XynCDBFV or the conventional EGFP. CONCLUSIONS: Our results demonstrated that Mtc6p was involved in regulating autophagy; attenuating or interdicting autophagy would dramatically improve the yields of desired proteins in K. marxianus, and this modulation could be achieved by focusing on the premature mutation of Mtc6p target.