The Role of Radiotherapy in Patients with Refractory Hodgkin Lymphoma after Brentuximab Vedotin and -/or Immune Checkpoint Inhibitors

PURPOSE/OBJECTIVE(S)

Brentuximab vedotin (BV) and immune checkpoint inhibitors (ICIs) had important roles in the treatment of relapse or refractory (R/R) Hodgkin lymphoma (HL). Treatment of refractory disease after BV and -/or ICIs remains a challenge. This study was conducted to evaluate the efficacy and safety of radiotherapy for R/R HL after failure to BV or ICIs.

MATERIALS/METHODS

We retrospectively analyzed patients in two institutions with R/R HL who had failed after first-line therapy, and were refractory to BV or ICIs, and received radiotherapy (RT) thereafter. The overall response rate (ORR), duration of response (DOR), progression-free survival (PFS) and overall survival (OS) were analyzed.

RESULTS

A total of 19 patients were enrolled. First-line systemic therapy consisted of ABVD (84.2%), AVD + ICIs (10.5%) and BEACOPP (5.3%), respectively. After first-line therapy, 15 patients (78.9%) were refractory, and 4 patients (21.1%) relapsed. After diagnosis of R/R HL, 8 patients (42.1%) received BV, and 17 patients (89.5%) received ICIs. RT was delivered in all 19 patients who failed after BV or ICIs. In 16 efficacy-evaluable patients, the ORR and CR rate were 100% and 100%. The median DOR was 17.2 months (range, 7.9 to 46.7 months). 3 patients progressed at outside of the radiation field. The in-field-response rate was 100%. The 12-month PFS and OS were 84.4% and 100%, respectively. No patients were reported with sever adverse events.

CONCLUSION

This study concluded that radiotherapy was effective and safe for refractory HL after BV or ICIs. Further prospective studies were warranted.

A novel classification model based on cerebral 18F-FDG uptake pattern facilitates the diagnosis of acute/subacute seropositive autoimmune encephalitis

PURPOSE

To explore the intrinsic alteration of cerebral 18F-FDG metabolism in acute/subacute seropositive autoimmune encephalitis (AE) and to propose a universal classification model based on 18F-FDG metabolic patterns to predict AE.

METHODS

Cerebral 18F-FDG PET images of 42 acute/subacute seropositive AE patients and 45 healthy controls (HCs) were compared using voxelwise and region of interest (ROI)-based schemes. The mean standardized uptake value ratios (SUVRs) of 59 subregions according to a modified Automated Anatomical Labeling (AAL) atlas were compared using a t-test. Subjects were randomly divided into a training set (70%) and a testing set (30%). Logistic regression models were built based on the SUVRs and the models were evaluated by determining their predictive value in the training and testing sets.

RESULTS

The 18F-FDG uptake pattern in the AE group was characterized by increased SUVRs in the brainstem, cerebellum, basal ganglia, and temporal lobe, and decreased SUVRs in the occipital, and frontal regions with voxelwise analysis (false discovery rate [FDR] p<0.05). Utilizing ROI-based analysis, we identified 15 subareas that exhibited statistically significant changes in SUVRs among AE patients compared to HC (FDR p<0.05). Further, a logistic regression model incorporating SUVRs from the calcarine cortex, putamen, supramarginal gyrus, cerebelum_10, and hippocampus successfully enhanced the positive predictive value from 0.76 to 0.86 when compared to visual assessments. This model also demonstrated potent predictive ability, with AUC values of 0.94 and 0.91 observed for the training and testing sets, respectively.

CONCLUSIONS

During the acute/subacute stages of seropositive AE, alterations in SUVRs appear to be concentrated within physiologically significant regions, ultimately defining the general cerebral metabolic pattern. By incorporating these key regions into a new classification model, we have improved the overall diagnostic efficiency of AE.

Evaluation of a ^{88}Sr^{+} Optical Clock with a Direct Measurement of the Blackbody Radiation Shift and Determination of the Clock Frequency

We report on an evaluation of an optical clock that uses the ^{2}S_{1/2}→^{2}D_{5/2} transition of a single ^{88}Sr^{+} ion as the reference. In contrast to previous work, we estimate the effective temperature of the blackbody radiation that shifts the reference transition directly during operation from the corresponding frequency shift and the well-characterized sensitivity to thermal radiation. We measure the clock output frequency against an independent ^{171}Yb^{+} ion clock, based on the ^{2}S_{1/2}(F=0)→^{2}F_{7/2}(F=3) electric octupole (E3) transition, and determine the frequency ratio with a total fractional uncertainty of 2.3×10^{-17}. Relying on a previous measurement of the ^{171}Yb^{+} (E3) clock frequency, we find the absolute frequency of the ^{88}Sr^{+} clock transition to be 444 779 044 095 485.277(59) Hz. Our result reduces the uncertainty by a factor of 3 compared with the previously most accurate measurement and may help to resolve so far inconsistent determinations of this value. We also show that for three simultaneously interrogated ^{88}Sr^{+} ions, the increased number causes the expected improvement of the short-term frequency instability of the optical clock without degrading its systematic uncertainty.

Pilot study on 11C-CFT dynamic imaging using total-body PET/CT: biodistribution and radiation dosimetry in Parkinson's disease

Objective

Total-body PET/CT equipment, uEXPLORER, is a newly developed imaging technology with a superior resolution, high sensitivity, and high signal-to-noise ratio, providing unique application advantages in the pharmacokinetic evaluation of positron tracers. While ¹¹C-CFT PET/CT has been widely utilized in the early diagnosis of Parkinson's disease (PD), it is limited by the short half-life of the radionuclide and an incomplete understanding of its biological distribution in humans. This study aimed to use a total-body PET/CT dynamic scan with ¹¹C-CFT imaging to describe the real-time internal biodistribution in PD patients and to obtain accurate radiation dosimetry.

Methods

Six male subjects with suspected PD underwent dynamic ¹¹C-CFT total-body PET/CT. Following a bedside intravenous bolus injection of 373.3 ± 71.56 MBq of ¹¹C-CFT, PET acquisition was performed synchronously for 75 min with a maximum axial field of view (AFOV) of 194 cm. Time-activity curves (TACs) were generated by delineating volumes of interest (VOIs) of the sourced organs using PMOD software. Tracer kinetics and cumulative organ activities were calculated, and absorbed doses were calculated and estimated using the OLINDA/EXM software.

Results

In the systemic TAC analysis of ¹¹C-CFT, several unique types of distribution patterns were obtained among several major organs, including a "Fast-in Fast-out" pattern in the kidneys, lungs, spleen, and thyroid, a "Fast-in Slow-out" curve in the heart wall, a "Slow-in Slow-out" mode in the liver, a "Low-level extending" pattern in the whole brain and muscle, and a "Slow-in to plateau" trend in the striatum and bone. The effective dose of ¹¹C-CFT was calculated to be 2.83E-03 mSv/MBq, which is only one-third of the literature value measured by the conventional method. Moreover, this dose is much lower compared to all other doses of DAT radioligands used in PET imaging.

Conclusion

This study is a pioneering application of total-body PET/CT to ¹¹C-CFT dynamic imaging. Our results confirmed that ¹¹C-CFT has a favorable total body biodistribution, an extremely low internal radiation dose, and high imaging quality, making it suitable for reasonable PD diagnosis in patients requiring multiple follow-up examinations.

Maintaining hypoxia environment of subchondral bone alleviates osteoarthritis progression

Abnormal subchondral bone remodeling featured by overactivated osteoclastogenesis leads to articular cartilage degeneration and osteoarthritis (OA) progression, but the mechanism is unclear. We used lymphocyte cytosolic protein 1 (Lcp1) knockout mice to suppress subchondral osteoclasts in a mice OA model with anterior cruciate ligament transection (ACLT), and Lcp1^-/- mice showed decreased bone remodeling in subchondral bone and retarded cartilage degeneration. For mechanisms, the activated osteoclasts in subchondral bone induced type-H vessels and elevated oxygen concentration, which ubiquitylated hypoxia-inducible factor 1 alpha subunit (HIF-1α) in chondrocytes and led to cartilage degeneration. Lcp1 knockout impeded angiogenesis, which maintained hypoxia environment in joints and delayed the OA progression. Stabilization of HIF-1α delayed cartilage degeneration, and knockdown of Hif1a abolished the protective effects of Lcp1 knockout. Last, we showed that Oroxylin A, an Lcp1-encoded protein l-plastin (LPL) inhibitor, could alleviate OA progression. In conclusion, maintaining hypoxic environment is an attractive strategy for OA treatment.

Evaluation of cartilage degeneration using multiparametric quantitative ultrashort echo time-based MRI: an ex vivo study

BACKGROUND

The quantitative MR techniques developed rapidly, vary MR-biomarkers have shown the ability to assess the quality of articular cartilage. This study aimed to investigate the diagnostic efficacy of multi-parametric quantitative ultrashort echo time (UTE)-based MRI for evaluating human cartilage degeneration.

METHODS

Twenty fresh anterolateral femoral condyle samples were obtained from 20 patients (age, 58.8±6.6 years; 6 females) who underwent total knee arthroplasty due to primary osteoarthritis (OA). The samples were imaged using UTE-based magnetization transfer (UTE-MT), UTE-based adiabatic T1ρ (UTE-AdiabT1ρ), UTE-based T2* (UTE-T2*), and CubeQuant-T2 sequences. Cartilage degeneration was classified based on the OA Research Society International grade and polarized light microscopy (PLM) collagen organization score. Spearman's correlation analysis was used to determine the relationships between quantitative MRI biomarkers [UTE-MT ratio (UTE-MTR), UTE-AdiabT1ρ, UTE-T2*, and CubeQuant-T2], OA Research Society International grade, and PLM collagen organization score. The diagnostic efficacy of each MRI biomarker for the detection of mild cartilage degeneration was assessed using the area under the receiver operating characteristic (ROC) curve (AUC).

RESULTS

Of the quantitative MRI biomarkers, UTE-MTR had the strongest correlation with both OA Research Society International grade (r=-0.709, P<0.001) and PLM collagen organization score (r=0.579, P<0.001). The UTE-MTR and UTE-AdiabT1ρ values showed significant differences between the normal group and the mild degeneration group (P=0.047 and 0.015, respectively), while UTE-T2* and CubeQuant-T2 did not. The UTE-MTR values were 15.90%±1.06% and 14.59%±1.35% for normal and mildly degenerated cartilage, respectively. The UTE-AdiabT1ρ values were 40.19±2.87 and 42.6±2.26 ms for normal and mildly degenerated cartilage, respectively. ROC analysis showed that UTE-MTR (AUC =0.805, P=0.001, sensitivity =73.7%, specificity =89.5%) had the highest diagnostic efficacy for mild cartilage degeneration, while UTE-AdiabT1ρ (AUC =0.727, P=0.017) and CubeQuant-T2 (AUC =0.712, P=0.026) showed lower diagnostic efficacy.

CONCLUSIONS

Quantitative UTE-MT and UTE-AdiabT1ρ biomarkers may potentially be used in the evaluation of early cartilage degeneration.

[Interventional effect of asiaticosdide on rats exposed to silica dust]

Objective: To investigate the effect of asiaticoside for fibrosis in lung tissues of rats exposed to silica and to explore its possible mechanism. Methods: 144 SD male rats were randomly divided into control group, model group, positive drug control group, asiaticoside high-dose group, medium-dose group and low-dose group, each group included 24 rats. Rats in the control group were perfused with 1.0 ml of normal saline, and the other groups were given 1.0 ml 50 mg/ml SiO(2) suspension. Gavage of herbal was given from the next day after model establishment, once a day. Rats in the positive drug control group were administration with 30 mg/kg tetrandrine and rats in the low-dose group, medium-dose group and high-dose group were given 20 mg/kg, 40 mg/kg and 60 mg/kg asiaticoside for fibrosis respectively. Rats in the control group and the model group were given 0.9% normal saline. The rats were sacrificed in on the 14th, 28th and 56th day after intragastric administration and collect the lung tissues to detect the content of hydroxyproline, TGF-β(1) and IL-18, observe the pathological changes of the lung tissues by HE and Masson staining and determine the expressions of Col-I, a-SMA, TGF-β in lung tissues by Western Blot. Results: On the 14th day, 28th day and 56th day after model establishment, the lung tissues of rats in the model group showed obvious inflammatory response and accumulation of collagen fibers, and the degree of inflammation and fibrosis increased with time. The intervention of asiaticoside could effectively inhibit the pathological changes of lung tissues. The contents of hydroxyproline, IL-18 and TGF-β1 in lung tissues of model group were higher than those in the control group (P<0.05) , while the level of hydroxyproline, IL-18 and TGF-β1 in asiaticoside groups were significantly decreased, and the difference was statistically signicant (P<0.05) . Compared with the control group, the expression levels of Col-I, TGF-β1and α-SMA in lung tissue of model group were increased (P<0.05) , while the expression level of Col-I, TGF-β1 and α-SMA were decreased after the intervention of asiaticoside, and the difference was statistically signicant (P<0.05) . Conclusion: Asiaticoside can inhibit the increase of Col-I, TGF-β1 and α-SMA content in the SiO(2)-induced lung tissues of rats, reduce the release of TGF-β1 and IL-18 inflammatory factors in lung tissue, and then inhibit the synthesis and deposition of extracellular matrix in rat lung tissue, and improve silicosis fibrosis.

The expression of cytokeratin and apoptosis-related molecules in echinococcosis related liver injury

The study aimed to investigate the expression of cytokeratin and apoptosis-related molecules in the livers of two types of hepatic echinococcosis mice models and to preliminarily explore the relationship between the expression of cytokeratin and apoptosis in echinococcosis related liver injury. We established a mouse model infected by Echinococcus granulosus and Echinococcus multilocularis and observed the expression of cytokeratin and apoptosis related proteins in the two types of hepatic echinococcosis tissues during different stages by immunohistochemical staining. A co-culture model was established using normal hepatocytes and different concentrations of E. granulosus and E. multilocularis protoscoleces. Cell Counting Kit-8 was used to detect cell proliferation, flow cytometry was used to detect hepatocyte apoptosis, and western blot was used to quantify cytokeratin and apoptosis-related proteins, such as caspase3, caspase9, Bcl-2, and Bax. Surgical specimens were obtained from patients with hepatic echinococcosis to analyze the expressions of cytokeratin, caspase3, caspase9, Bcl-2, and Bax by western blot. The expressions of cytokeratin and caspase3 were analyzed by immunohistochemistry. The qRT-PCR method was used to determine the expression of CK8 and CK18 in the liver tissues. In vivo experiments showed that compared to that in the control group, the cytokeratin and caspase3 proteins in the liver tissues of the two types of hepatic echinococcosis were strongly expressed around the lesions of liver echinococcosis; there was a difference between cytokeratin expression of the two different echinococcosis parasites in the liver. Echinococcus granulosus and Echinococcus multilocularis in the co-culture model in vitro could promote the expression of CK, caspase3, caspase9, and Bax protein, decrease the expression of Bcl-2, promote hepatocyte apoptosis, and inhibit cell proliferation; in clinical samples, we found that compared with that in the normal tissues, the expression of cytokeratin, caspase3, caspase9, and Bax in echinococcus tissues was high, but that in Bcl-2 was low. Furthermore, the expression of CK8 and CK18 mRNA were higher in echinococcus tissues than that in the normal tissues and immunohistochemistry analysis also showed that cytokeratin and caspase3 levels were higher in echinococcus tissues than that in the normal tissues. The expression of cytokeratin and apoptosis-related molecules, reflecting liver damage, is high in the liver and is caused due to hepatic echinococcosis. This study provides the first evidence of cytokeratin could be useful for evaluating liver tissue damage caused by echinococcus infection.

[Interventional effect of metformin on pulmonary inflammation and pulmonary fibrosis in silicotic rats]

Objective: To investigate the interventional effect of metformin on pulmonary inflammation and pulmonary fibrosis in silicotic rats. Methods: In April 2019, 48 Wistar male rats of SPF grade were randomly divided into negative control group, metformin control group, silicon dioxide (SiO₂) model group, low, medium and high dose metformin intervention group according to the random number table method, 8 rats in each group. The SiO₂ model group and the low, medium and high dose metformin intervention groups were given 1 ml 50 mg/ml of SiO₂ by intratracheal instillation, the negative control group and the metformin control group were given 1 ml normal saline by intratracheal instillation. 24 hours later, the low, medium and high dose metformin intervention groups and the metformin control group were treated with 100, 200, 400 and 400 mg/kg metformin daily, the control and SiO₂ model groups received normal saline daily. Then the rats were sacrificed at the 28th day after SiO₂ exposure. The changes of rat body weight and pathological examination of rat lung tissue were observed, and the lung organ coefficient, the content of hydroxyproline (HYP) , the expression levels of inflammatory factors transforming growth factor beta1 (TGF-β1) , tumor necrosis factor-alpha (TNF-α) , interleukin-1beta (IL-1β) and the protein expression of E-cadherin (E-Cad) , Vimentin, α-SMA were detected. Results: Compared with the negative control group, SiO₂ model group had a significant decrease in the body weight of rats (P<0.05) , lung organ coefficient, alveolitis and fibrosis scores, HYP content and the levels of TGF-β1, TNF-α, IL-1β were all significantly increased (P<0.05) . Compared with the SiO₂ model group, the weights of the rats in the medium and high dose intervention group of metformin increased significantly (P<0.05) . And after intervention with different doses of metformin, the lung organ coefficient, alveolitis and fibrosis scores, HYP content and the levels of TGF-β1, TNF-α and IL-1β were significantly decreased (P<0.05) . Immunohistochemistry and Western blotting results showed that compared with the negative control group, the expression of E-Cad of the SiO₂ model group was decreased, and the expression levels of Vimentin and α-SMA were significantly increased (P<0.05) . After metformin intervention, the expression of E-Cad was significantly increased, the expression levels of Vimentin and α-SMA were significantly decreased (P<0.05) . Conclusion: Metformin can reduce lung tissue inflammation and fibrosis in rats exposed to SiO₂ dust, which may be related to reducing the expression of inflammatory factors in lung tissue and inhibiting the EMT process.

[Diagnosis, treatment and outcome of adnexal torsion at different gestational weeks during pregnancy]

Objective: To investigate the clinical characteristics, diagnosis, treatment and outcome of adnexal torsion at different gestational weeks during pregnancy. Methods: A retrospective analysis was conducted of the clinical data of 24 pregnancy patients with adnexal torsion, aged 21-38 (30.6±4.4) years old, who were admitted and delivered in Peking University Third Hospital from 2015 to 2019. According to the gestational age, all patients were divided into two groups:<28 weeks group (11cases) and ≥28 weeks group (13 cases), to compare the intergroup differences in clinical characteristics, treatment and outcome, and the differences of clinical data and outcome between two groups were compared. Results: The proportion of patients with twin pregnancy and assisted reproductive technology in the<28 weeks group was significantly higher than that in the ≥28 weeks group (5/11 vs 1/13, 8/11 vs 1/13, P<0.05). No significant differences between the two groups were recorded in terms of the size of the adnexal mass, the cycles of torsion and the duration from onset to operation. Compared with the≥28 weeks group, the adnexal removal rate of the<28 weeks group was lower (3/11 vs 6/13), but the difference was not statistically significant. The proportion of blood flow signals of ultrasound before operation, cases undergoing laparoscopic surgery and cases whose pathological findings were physiological cysts in the<28 weeks group were significantly higher than that in the ≥28 weeks group (8/11 vs 4/13, 8/11 vs 0, 8/11vs 4/13; P<0.05). Concerning the pregnancy outcomes, there was no difference in the mode of delivery, the delivery gestational age and the body weight of newborns between the two groups. Conclusions: The patients with adnexal torsion prior to 28 weeks(<28 weeks)of pregnancy were more likely to be conceived by assisted reproductive technologies, and the etiology was more likely to be ovarian physiological cysts. Both laparoscopy and laparotomy were safe and effective in the treatment of adnexal torsion with good outcome for mother and infant in the study.

[Investigation on occupational hazards in 20 automobile manufacturing enterprises in Shandong Province]

Objective: To investigate the current situation of occupational hazards in automobile manufacturing enterprises in Shandong Province. Methods: From February to May 2019, the convenience sampling method was adopted to conduct on-site occupational health surveys with 20 automobile manufacturing enterprises in Shandong Province as the survey subjects, to detect the occupational hazard factors in the workplaces and individual exposure levels, and to analyze the occupational health check results of operators. Results: There were 13 small-sized, 4 medium-sized and 3 large-sized enterprises among the 20 automobile manufacturing enterprises. The detection results of benzene and toluene in the workplaces met the occupational exposure limits, and the detection results of welding fumes, manganese and its compounds, and xylene exceed the occupational exposure limits. The maximum short-term exposure concentration (C(STE)) of welding fume in the air of workplaces was 24.23 mg/m(3), and the over-standard rate was 11.0% (16/146) . The maximum time-weighted average concentration (C(TWA)) of welding fume of operators is 10.60 mg/m(3), and the over-standard rate was 11.0% (8/73) . The maximum C(STE) of manganese and its compounds in the air of workplaces was 0.879 mg/m(3), and the of manganese and its compounds of operators was 0.175 mg/m(3), and the over-standard rate was 5.7% (4/70) . The maximum xylene C(STE) in the air of workplaces was 230.00 mg/m(3), and the over-standard rate was 3.9% (2/51) . The maximum xylene C(TWA) of operators was 70.40 mg/m(3), the over-standard rate was 3.6% (1/28) . Among the 4775 workers exposed to occupational hazards, 38 (0.80%) were suspected of electric welder's pneumoconiosis, 27 (0.57%) were suspected of manganese poisoning and 31 (0.65%) were suspected of chronic low-concentration benzene and benzene series poisoning. The detection rates of suspected occupational diseases among workers in small and medium-sized enterprises were relatively high, 2.86% (30/1048) and 4.51% (51/1132) respectively. There was a statistically significant difference in the detection rates of suspected occupational diseases among the operators of different scale automobile manufacturers (P<0.05) . Conclusion: The exposure levels of electric welding fumes, manganese and its compounds in welding jobs and xylene exposure levels in spray painting jobsin Shandong Province's automobile manufacturing enterprises are more serious. The supervision and management of occupational hygiene should be strengthened, the working environment should be improved, and the health of welding and painting workers should be protected.

Improved Limits for Violations of Local Position Invariance from Atomic Clock Comparisons

We compare two optical clocks based on the ^{2}S_{1/2}(F=0)→^{2}D_{3/2}(F=2) electric quadrupole (E2) and the ^{2}S_{1/2}(F=0)→^{2}F_{7/2}(F=3) electric octupole (E3) transition of ^{171}Yb^{+} and measure the frequency ratio ν_{E3}/ν_{E2}=0.932829404530965376(32), improving upon previous measurements by an order of magnitude. Using two caesium fountain clocks, we find ν_{E3}=642121496772645.10(8)  Hz, the most accurate determination of an optical transition frequency to date. Repeated measurements of both quantities over several years are analyzed for potential violations of local position invariance. We improve by factors of about 20 and 2 the limits for fractional temporal variations of the fine structure constant α to 1.0(1.1)×10^{-18}/yr and of the proton-to-electron mass ratio μ to -8(36)×10^{-18}/yr. Using the annual variation of the Sun's gravitational potential at Earth Φ, we improve limits for a potential coupling of both constants to gravity, (c^{2}/α)(dα/dΦ)=14(11)×10^{-9} and (c^{2}/μ)(dμ/dΦ)=7(45)×10^{-8}.

[Research progress of ferroptosis-related mechanism and diseases]

Ferroptosis is a new programmed cell death characterized by iron dependent and intracellular oxidative accumulation. Current studies have confirmed that ferroptosis is involved in the occurrence and development of neurotoxicity injury, tumors, cardiovascular diseases and other diseases. This paper reviews the mechanisms of ferroptosis and its role in related diseases based on recent studies.

Coherent Suppression of Tensor Frequency Shifts through Magnetic Field Rotation

We introduce a scheme to coherently suppress second-rank tensor frequency shifts in atomic clocks, relying on the continuous rotation of an external magnetic field during the free atomic state evolution in a Ramsey sequence. The method retrieves the unperturbed frequency within a single interrogation cycle and is readily applicable to various atomic clock systems. For the frequency shift due to the electric quadrupole interaction, we experimentally demonstrate suppression by more than two orders of magnitude for the ^{2}S_{1/2}→^{2}D_{3/2} transition of a single trapped ^{171}Yb^{+} ion. The scheme provides particular advantages in the case of the ^{171}Yb^{+} ^{2}S_{1/2}→^{2}F_{7/2} electric octupole (E3) transition. For an improved estimate of the residual quadrupole shift for this transition, we measure the excited state electric quadrupole moments Θ(^{2}D_{3/2})=1.95(1)ea_{0}^{2} and Θ(^{2}F_{7/2})=-0.0297(5)ea_{0}^{2} with e the elementary charge and a_{0} the Bohr radius, improving the measurement uncertainties by one order of magnitude.

New options for increasing the sensitivity, specificity and scope of synergistic contrast magnetic resonance imaging (scMRI) using Multiplied, Added, Subtracted and/or FiTted (MASTIR) pulse sequences

This paper reviews magnetic resonance (MR) pulse sequences in which the same or different tissue properties (TPs) such as T1 and T2 are used to contribute synergistically to lesion contrast. It also shows how synergistic contrast can be created with Multiplied, Added, Subtracted and/or fiTted Inversion Recovery (MASTIR) sequences, and be used to improve the sensitivity, specificity and scope of clinical magnetic resonance imaging (MRI) protocols. Synergistic contrast can be created from: (i) the same TP, e.g., T1 used twice or more in a pulse sequence; (ii) different TPs such as ρm, T1, T2, and D* used once or more within a sequence, and (iii) additional suppression or reduction of signals from tissues and/or fluids such as fat, long T2 tissues and cerebrospinal fluid (CSF). The short inversion time (TI) inversion recovery (IR) (STIR) and double IR (DIR) sequences usually show synergistic positive contrast for lesions which have increases in both T1 and T2. The diffusion weighted pulsed gradient spin echo (PGSE) sequence shows synergistic contrast for lesions which have an increase in T2 and a decrease in D*; the sequence is both positively weighted for T2 and negatively weighted for D*. In the brain, when an IR sequence nulling white matter has subtracted from it an IR sequence nulling gray matter to form the subtracted IR (SIR) sequence, increases in the single TP T1 between the two nulling points of the original two sequences generate high synergistic positive contrast. In addition, the subtraction to produce the SIR sequence reduces fat and CSF signals. To provide high sensitivity to changes in TPs in disease the SIR sequence can be used (i) alone to provide synergistic T1 contrast as above; (ii) with T2-weighting to provide synergistic T1 and T2 contrast, and (iii) with T2- and D*-weighting to provide synergistic T1, T2, and D* contrast. The SIR sequence can also be used in reversed form (longer TI form minus shorter TI form) to produce very high positive synergistic T1 contrast for reductions in T1, and so increase the positive contrast enhancement produced by clinical gadolinium-based contrast agents (GBCAs) when they reduce T1. The specificity of MRI examinations can be improved by using the reversed SIR sequence with a long echo time (TE) gradient echo as well as echo subtraction to show synergistic high contrast from T1 and T2* shortening produced by organic iron. Other added and subtracted forms of the MASTIR sequence can be used synergistically to selectively show myelin, myelin water and fluids including blood and CSF. Protocols using MASTIR sequences to provide synergistic contrast in MRI of the brain, prostate and articular cartilage are included as illustrative examples, and the features of synergistic contrast MRI (scMRI) are compared to those of multiparametric MRI (mpMRI) and functional MRI (fMRI).

Effect of miR-29c on renal fibrosis in diabetic rats via the AMPK/mTOR signaling pathway

OBJECTIVE

To explore the effect of micro-ribonucleic acid (miR)-29c on renal fibrosis in diabetic rats through the adenosine 5'-monophosphate-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) signaling pathway, and to investigate its related mechanism by the research on the effect of miR-29c on the expression of fibrosis-related genes.

MATERIALS AND METHODS

The rat model of diabetic nephropathy (DN) was established, and the levels of fasting blood glucose (FBG), 24 h urine protein (24h-Pro), blood urea nitrogen (BUN), and serum creatinine (sCr) were monitored. After the rats were executed, kidney tissues were dissected, stained with paraffin and embedded in hematoxylin and eosin (H&E). Then, Western blotting was used to detect the levels of miR-29c, phosphorylated-AMPK (p-AMPK), α-smooth muscle actin (α-SMA), tumor necrosis factor-α (TNF-α), and macrophage migration inhibitory factor (MIF). The human renal tubular epithelial HK-2 cell line was treated with high glucose (HG) to simulate DN cell status in vivo. After that, the expressions of miR-29c and the renal fibrosis marker α-SMA were examined via Western blotting. Finally, the level of α-SMA was measured by Western blotting after HG treatment combined with miR-29c silencing.

RESULTS

The levels of FBG, BUN, sCr, and 24h-Pro in DN model rats were significantly higher than those in rats of control group. The data manifested that the DN model was successfully established. The expression level of miR-29c in DN model rats was markedly increased and that of the downstream protein p-AMPK also exhibited a significantly increasing trend. In addition, the levels of α-SMA, TNF-α, and MIF were elevated. The expression levels of miR-29c and α-SMA were increased markedly after the human renal tubular epithelial HK-2 cell line was treated with HG, but the expression of α-SMA was reduced after HG treatment combined with miR-29c silencing for 24 h.

CONCLUSIONS

MiR-29c is probably related to the occurrence and development of DN. Besides, miR-29c silencing may inhibit the DN renal fibrosis through AMPK/mTOR signals, so miR-29c may be an effective target for the treatment of DN renal fibrosis.

Effects of the prebiotic inulin-type fructans on post-antibiotic reconstitution of the gut microbiome

AIMS

Interventions using prebiotic inulin-type fructans (ITFs) are widely prescribed to modulate the gut microbiota composition and activity to promote health. However, the impacts of ITFs on post-antibiotic reconstitution of the gut microbiome remain incompletely understood. The aim of the present study was to investigate the effects of ITFs supplementation on intestinal inflammation, the composition of the intestinal microbiota and the colonic transcriptome after antibiotic treatment.

METHODS AND RESULTS

Male BALB/c mice were subjected to an antibiotic cocktail (ABx) treatment for 7 days, and their microbiomes were then reconstituted either spontaneously or with ITFs supplementation (5%) for 14 days. Our data showed that ITFs supplementation delayed the recovery of antibiotic-induced colitis compared with the spontaneous recovery. Neither ITFs supplementation nor spontaneous recovery could restore the microbial community composition at the genus level back to its initial composition. ITFs supplementation increased the relative abundance of some beneficial bacteria and butyrate levels, but resulted in selective blooms of some opportunistic pathogens and elevated the pathways associated with diseases linked to gut microbiota function. Both ITFs supplementation and spontaneous recovery could restore the colonic transcriptome nearly to the initial profile to a certain extent; however, ITFs supplementation delayed the restoration of the immunoglobulin genes compared to spontaneous recovery.

CONCLUSION

These data showed that post-antibiotic ITFs consumption did not always lead to beneficial effects but might lead to potential adverse effects in the context of dysbiosis.

SIGNIFICANCE AND IMPACT OF THE STUDY

These findings highlighted that caution is required when supplementing ITFs to restore intestinal homeostasis in the context of dysbiosis resulting from broad-spectrum antibiotics.

The accuracy of prostate lesion localization in cognitive fusion

PURPOSE

Prostate cancer (PCa) is one of the most common cancers in elderly men worldwide. Systematic biopsy guided by transrectal ultrasound remains the standard for PCa diagnosis; however, the false negative rate is 10-20%. Multiparametric magnetic resonance imaging (mpMRI) allows PCa visualization with a more precise localization and a higher accuracy and specificity for the detection of PCa. The physician can mentally relocate the most appropriate area detected on the prebiopsy mpMRI, based on its zonal topography and anatomical landmarks, called cognitive fusion. Herein, we concentrated on the accuracy of PCa localization in cognitive fusion compared with MRI-TRUS fusion and explored the applied scope of cognitive fusion.

METHODS

Thirty-two eligible patients with 36 PCa lesions were recruited for our study. TRUS examinations and MRI-TRUS fusion procedures were performed by experienced operators. The cognitive fusion images were compared using the TRUS image in a MRI-TRUS fusion workstation.

RESULTS

Using cognitive fusion imaging, 86.1% of the lesions were accurately located by the senior sonographer and 69.4% of the lesions were accurately located by the junior sonographer. The maximum diameter and PI-RADS score of the lesions were important factors that affected the accuracy of cognitive fusion (P < 0.05). Furthermore, the lesions with high PI-RADS scores and the lesions with large diameters were more accurately located using cognitive fusion (P < 0.05).

CONCLUSIONS

Cognitive fusion is a reliable technique with dependency on working experience, and its accuracy of locating suspicious lesions is consistent with MRI-TRUS fusion in patients with high PI-RADS score and large lesions.

[Analysis of the relationship between the changes of lung function and serum proinflammatory cytokines in workers occupationally exposed to toluene diisocyanate]

Objective: To analyze the correlation between the changes of lung function and serum proinflammatory cytokines in workers occupationally exposed to toluene diisocyanate (TDI), and to explore the evaluation index of respiratory toxicity of TDI. Methods: In October 2014, 61 male workers engaged in TDI synthesis process, purification process, packaging process and the above production process in a TDI factory in western China were selected as TDI exposure group; 62 male enterprise managers who were not exposed to TDI and other known allergenic chemicals were selected as control group, which were matched at the age of workers in exposure group. The questionnaire survey obtained information such as gender, length of service, age, occupational history, exposed length of service and so on. The lung function indexes [forced expiratory volume in the first second (FEV1), forced vital capacity (FVC), FEV1/FVC] and serum levels of interleukin (IL)-1 β, IL-6, IL-8, tumor necrosis factor (TNF)-α, macrophage inflammatory factor-1 β, monocyte chemoattractant factor-1 and vascular endothelial growth factor were measured. The urine was collected after the weekend shift, and the concentration of (TDA), the metabolite of TDI, was determined as the index of internal exposure. Spearman rank correlation was used to analyze the correlation between cytokines and lung function indexes, and multivariate linear regression was used to analyze the changes of lung function indexes and cytokines with TDI exposure concentration and time. Results: The median age (P₅-P₉₅) of the exposed group and the control group was 36.5 (24.0-51.0) and 38.0 (24.0-50.0) years, respectively. In the exposed group, the median length of service (P₅-P₉₅) was 6.94 (0.97-26.33) years, and the median concentration of TDA in urine was 15.56 (2.28-112.16) ng/ml. The three indexes of lung function, FVC, FEV1, FEV1/FVC and the levels of serum IL-8 and TNF-α were significantly lower than those in the control group (P<0.01). With the increase of exposure concentration and exposure time, the level of serum TNF-α, FVC and FEV1 decreased, and showed a good dose-effect and time-effect relationship (all P_trend values< 0.05). Serum IL-8 and TNF-α were positively correlated with FVC, FEV1 and FEV1/FVC (all P values<0.01). Conclusion: The levels of serum inflammatory factors IL-8 and TNF-α in worker exposed to TDI are related to lung function indexes, which can be used as early evaluation indexes of respiratory toxicity induced by TDI.

Use of Multiplied, Added, Subtracted and/or FiTted Inversion Recovery (MASTIR) pulse sequences

The group of Multiplied, Added, Subtracted and/or fiTted Inversion Recovery (MASTIR) pulse sequences in which usually two or more inversion recovery (IR) images of different types are combined is described, and uses for this type of sequence are outlined. IR sequences of different types can be multiplied, added, subtracted, and/or fitted together to produce variants of the MASTIR sequence. The sequences provide a range of options for increasing image contrast, demonstrating specific tissues and fluids of interest, and suppressing unwanted signals. A formalism using the concept of pulse sequences as tissue property filters is used to explain the signal, contrast and weighting of the pulse sequences with both univariate and multivariate filter models. Subtraction of one magnitude reconstructed IR image from another with a shorter TI can produce very high T₁ dependent positive contrast from small increases in T₁. The reverse subtracted IR sequence can provide high positive contrast enhancement with gadolinium chelates and iron deposition which decrease T₁. Additional contrast to that arising from increases in T₁ can be produced by supplementing this with contrast arising from concurrent increases in ρ_m and T₂, as well as increases or decreases in diffusion using subtraction IR with echo subtraction and/or diffusion subtraction. Phase images may show 180º differences as a result of rotating into the transverse plane both positive and negative longitudinal magnetization. Phase images with contrast arising in this way, or other ways, can be multiplied by magnitude IR images to increase the contrast of the latter. Magnetization Transfer (MT) and susceptibility can be used with IR sequences to improve contrast. Selective images of white and brown adipose tissue lipid and water components can be produced using different TIs and in and out-of-phase TEs. Selective images of ultrashort and short T₂ tissue components can be produced by nulling long T₂ tissue components with an inversion pulse and subtraction of images with longer TEs from images with ultrashort TEs. The Double Echo Sliding IR (DESIRE) sequence provides images with a wide range of TIs from which it is possible to choose values of TI to achieve particular types of tissue and/or fluid contrast (e.g., for subtraction with different TIs, as described above, and for long T₂ tissue signal nulling with UTE sequences). Unwanted tissue and fluid signals can be suppressed by addition and subtraction of phase-sensitive (ps) and magnitude reconstructed images. The sequence also offers options for synergistic use of the changes in blood and tissue ρ_m, T₁, T₂/T₂*, D* and perfusion that can be seen with fMRI of the brain. In-vivo and ex-vivo illustrative examples of normal brain, cartilage, multiple sclerosis, Alzheimer's disease, and peripheral nerve imaged with different forms of the MASTIR sequence are included.

Quantitative ultrashort echo time magnetization transfer (UTE-MT) for diagnosis of early cartilage degeneration: comparison with UTE-T2* and T2 mapping

Background

To investigate the feasibility of using quantitative ultrashort echo time magnetization transfer (UTE-MT) technique in diagnosing early cartilage degeneration and to compare the technique's diagnostic efficacy with UTE-T2* mapping and T2 mapping.

Methods

Twenty human anterolateral condyle specimens with degeneration were obtained from volunteers undergoing total knee arthroplasty (TKA); they then underwent magnetic resonance (MR) scan on a clinical 3.0T scanner (GE, MR750). Seventy-two regions of interest (ROI) were manually drawn on specimens for UTE-MT, UTE-T2*, and T2 measurement, and the corresponding cartilage-bone regions were further divided into degeneration classifications of normal (n=11, Mankin scores 0-1), mild (n=28, Mankin scores 2-5), moderate (n=21, Mankin scores 6-9), and severe (n=12, Mankin scores 10-14) based on histological measures of degeneration (i.e., Mankin scores) as a reference standard. Differences among groups and correlations between quantitative MR parameters and Mankin scores were assessed using analysis of variance (ANOVA), Tamhane-T2, LSD, Kruskal-Wallis tests, and Spearman's correlation coefficient. The receiver-operating characteristic (ROC) curve was used to compare the diagnostic efficacy of different quantitative MR parameters for the detection of mild cartilage degeneration.

Results

The UTE magnetization transfer ratio (UTE-MTR) in the normal group was significantly different from the mild group (P=0.021), moderate group (P<0.001), and severe group (P<0.001). Significant differences were observed in the T2* values between both the normal group and the moderate group (P<0.032), and between the normal group and the severe group (P<0.001). For T2 values, the only significant difference was observed between the severe group and the normal group (P=0.011). The UTE-MTR, UTE-T2*, and T2 values were all significantly correlated with Mankin scores: UTE-MTR values were strongly (r=-0.678, P<0.001) correlated, UTE-T2* values were markedly correlated (r=-0.501, P<0.001), and T2 values were weakly correlated (r=0.337, P=0.004) correlated with Mankin scores. The diagnostic efficacy of UTE-MTR (AUC =0.828, P=0.002) was better than UTE T2* mapping and T2 mapping (AUC =0.604, P=0.318; AUC =0.644, P=0.165, respectively) for the diagnosis of early cartilage degeneration.

Conclusions

UTE-MTR values were strongly correlated with histological grades of cartilage degeneration, and its diagnostic efficacy was better than both UTE T2* mapping and T2 mapping in detecting early cartilage degeneration. Once the clinical potential of the technique has been confirmed, UTE-MT may provide a promising imaging biomarker with potential application in a more comprehensive diagnosis and monitoring of cartilage degeneration.

[An investigation of occupational exposure to welding fume, manganese, and manganese compounds in a large container manufacturing enterprise]

Objective: To investigate the current status of the occupational hazards of welding fume, manganese, and manganese compounds in the welding environment of a large container manufacturing enterprise, as well as the status of occupational health examination of workers, and to provide a basis for improving the welding environment of this enterprise. Methods: In August 2016, July 2017, and August 2018, convenience sampling was used to perform an on-site occupational hygiene survey of the welding workshop for three consecutive years, and welding fume, manganese and, manganese compounds (counted as manganese dioxide) were measured for their workplace exposure concentrations and exposure levels in workers. A comprehensive analysis was performed for the results of occupational health examination. Results: Welding fume, manganese, and manganese compounds in the welding environment gradually increased from 2016 to 2018 (χ(2)(trend)=5.14 and 5.54, P<0.05). The maximum over-standard rate of concentration-short term exposure limit was 43.3% (13/30) for welding fume and 40.0% (12/30) for manganese and its compounds, and the maximum over-standard rate of time-weighted average concentration was 26.7% (8/30) for welding fume and 23.3% (7/30) for manganese and its compounds. Abnormalities were observed in the occupational health examination of welding workers in 2016-2018, among which respiratory system abnormalities (cough, expectoration, and wheezing), nervous system abnormalities (dizziness, fatigue, sleep disorders, amnesia, hyperhidrosis, and palpitations), and electrocardiogram abnormalities (bundle conduction block) had an incidence rate of above 10.0%, and the incidence rate of abnormalities on posterior-anterior X-ray high-kV chest radiograph was close to 8.9% (30/336) . Conclusion: There is severe exposure to welding fume, manganese, and manganese compounds among workers in this enterprise, which cause great hazards to the health of workers. It is necessary to strengthen occupational health management, take measures to improve the welding environment, and enhance occupational disease prevention.

Effect of peak power enhancement of ferrite phase shifter from full-height to increased-height rectangular waveguide

In order to enhance the high-power performance of the ferrite phase shifter (PS), a method of increasing waveguide height is proposed and experimentally demonstrated. Dual-toroid geometry is utilized as a high-power structure. Two configurations of X-band PSs with full-height (FH) and increased-height (IH) waveguides are designed and fabricated while keeping other parameters consistent. Comparative analysis based on simulation and high-power experiments is conducted. The simulation results agree well with experiments. Compared with the FHPS, the IHPS can enhance the peak-power-capacity from 90 kW to 140 kW while maintaining almost the same insertion loss of 0.5 dB with a slight increase in differential phase shift from 360° to 380°.

[Analysis of occupational health surveillance for workers on offshore platforms]

Objective: To understand the status of occupational health surveillance for workers on offshore platforms. Methods: The research period was from 2014 to 2016. From 2014 to 2016, a cross-sectional survey method was adopted to select 429 people for offshore oil production, drilling and operation platforms and their first-line workers to conduct workplace occupational hygiene. Investigation, occupational hazard factor testing, occupational health check of workers, collation and statistical analysis of surveys and test data, and comparison of occupational health surveillance among workers of different types of offshore platforms. Results: From 2014 to 2016, the results of chemical harmful factors detection of occupational diseases in the offshore platform were in line with the national occupational health exposure limit requirements. The noise of some platform posts exceeded the standard, such as: oil platform oil, oil and oil and gas processing workers, diesel engines for drilling and working platforms. Worker noise exceeds national occupational health limits p[L(ex, 8 h)>85 dB(A)].There was a statistically significant difference in the occupational health of workers on the same platform with the age and length of service (P<0.05). Conclusion: Workers on different platforms at sea may be subject to different levels of occupational health damage, and the occupational hazards brought by noise to platform workers are particularly prominent.

[Expression changes of miRNA-29b-3p and miRNA-34c-3p in lung tissue of rats exposed to silica and A549 cells]

Objective: To investigate the role of microRNA-29b-3p (miRNA-29b-3p) and miRNA-34c-3p in the process of pulmonary fibrosis, we detected the expression levels of miRNA-29b-3p and miRNA-34c-3p in the lung tissue of rats exposed to silica and A549 cells. Methods: SPF male Wistar rats were randomly divided into 1, 7, 14, 21, 28 d control group and silica (SiO(2)) dusting group, with 6 rats in each group. One-time non-exposure method was used to infuse 1ml SiO(2) suspension. The rat SiO(2) dusting group was established in the liquid, and the control rats were intratracheally injected with 1 ml of sterile physiological saline in the same manner. The lung tissues of each group were collected at the corresponding time points after dusting. Three of the rats were taken out for pathological observation, and the other three were used to screen differentially expressed miRNAs in lung tissue by miRNA microarray technology. A549 cells were cultured at the in vitro cell level and divided into control group, SiO(2) stimulation group and TGF-β(1) stimulation group, and cells were collected at 12, 24 and 48 h after treatment. The expression levels of miRNA-29b-3p and miRNA-34c-3p in rat lung tissue and A549 cells were verified by real-time PCR (qRT-PCR), target gene prediction of miRNA-29b-3p and miRNA-34c-3p and perform GO enrichment analysis and KEGG pathway analysis. Results: The weight growth rate of the control group was significantly higher than that of the SiO(2) dusting group. Compared with the control group, the lung mass and lung coefficient of the SiO(2) dusting group were significantly increased (P<0.05). The inflammatory response of the lungs in the control group was significantly reduced at 21 and 28 days, and the inflammatory cells infiltrated in the lung tissue of the SiO2 group. The rats in the control group had a small amount of collagen at 21 and 28 days. A large amount of collagen fiber deposition began to appear in the lung tissue of rats exposed to SiO(2) for 21 days. Compared with the control group, the expression levels of miRNA-29b-3p and miRNA-34c-3p in the SiO(2) dusting group were significantly down-regulated, and there was significant difference compared with the control group (P<0.05). The expression levels of miRNA-29b-3p and miRNA-34c-3p in A549 cells treated with SiO(2) and human recombinant TGF-β1 were significantly lower than those in the control group at 24 h and 48 h, and the difference was statistically significant (P<0.05). Conclusion: Down-regulation of miRNA-29b-3p and miR-34c-3p in rat lung tissue A549 cells may be associated with the development of early silicosis and is expected to be an indicator of early silicosis diagnosis and prognosis.

Evaluation of cortical bone perfusion using dynamic contrast enhanced ultrashort echo time imaging: a feasibility study

Background

Dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) has been used to study perfusion in a wide variety of soft tissues including the bone marrow. Study of perfusion in hard tissues such as cortical bone has been much more limited because of the lack of detectable MR signal from them using conventional pulse sequences. However, two-dimensional (2D) ultrashort echo time (UTE) sequences detect signal from cortical bone and allow fast imaging of this tissue. In addition, adiabatic 2D inversion recovery UTE (IR-UTE) sequences can provide excellent signal suppression of soft tissues, such as muscle and marrow, and allow cortical bone to be seen with high contrast and reduced artefacts. We aimed to assess the feasibility of using 2D UTE and 2D IR-UTE sequences to perform DCE-MRI in the cortical bone of rabbits and human volunteers.

Methods

Cortical bone perfusion was studied in rabbits (n=12) and human volunteers (n=3) using 2D UTE and 2D IR-UTE sequences on a clinical 3T scanner. Dynamic data with an in-plane resolution of ~0.5×0.5 mm², single slice thickness of 3 mm for rabbits and 10 mm for human volunteers, and temporal resolution of 23 s for 2D UTE imaging of rabbits, 28 s for 2D UTE imaging of human volunteers, and 60 s for 2D IR-UTE imaging of both the rabbits and human volunteers were acquired before and after the injection of a Gd contrast agent (Gd-BOPTA: Multihance; Bracco Imaging SpA, Milan, Italy). The dose was 0.06 mmol/kg for rabbits and 0.2 mmol/kg for human subjects. Kinetic analyses based on the Brix model, as well as simple calculations of maximum enhancement (ME) and enhancement slope (ES), were performed.

Results

The 12 rabbits showed a mean K^trans of 0.36±0.07 min^-1, K_ep of 8.42±3.17 min^-1, ME of 28.30±6.83, ES of 0.35±0.18 for the femur with the 2D UTE sequence, and a mean K^trans of 0.45±0.10 min^-1, K_ep of 9.80±0.50 min^-1, ME of 48.84±12.12, and ES of 0.69±0.27 for the femur with the 2D IR-UTE sequence. Lower ME and ES values were observed in the tibial midshaft of healthy human volunteers compared to rabbits.

Conclusions

These results show that 2D UTE and 2D IR-UTE sequences are capable of detecting dynamic contrast enhancement in cortical bone in both rabbits and healthy human volunteers. Clinical studies with these techniques are likely to be feasible.

[Preliminary analysis of differential expression of miRNA-423-5p and miRNA-26a-5p in lung tissue of early silicotic rats]

Objective: To screen the changes of microRNA (miRNA) expression profiles in lung tissues of early silicosis rats, and provide a basis for functional analysis of differential microRNA. Methods: SPF Wistar male rats were randomly divided into a negative control group and SiO(2)-exposed groups, with 30 rats in each group. The model of silicosis in rats was established by intratracheal instillation of 1 ml SiO(2) suspension, and the control rats were treated with 1mL in the same way to sterilize normal saline. The lung tissues of two group were collected at the 1, 7, 14, 21, 28 d after SiO(2)-exposed. Three of the rat lung tissues were used for pathological observation, and the other three were used to screen differentially expressed miRNAs in lung tissue by miRNA microarray technology. miRNA chip screening and RT-qPCR were used to verify the expression levels of miRNA-423-5p and miRNA-26a-5p in the two groups. miRNA-423-5p and miRNA-26a-5p are predicted by target genes and analyzed by GO (gene ontology) enrichment analysis and KEGG (kyoto encyclopedia of genes and genomes) pathway analysis. Results: In the control group, the inflammatory response of lung tissue 21 and 28 days was significantly reduced compared with 1, 7 and 14 days, and the inflammatory cells infiltrated in the lung tissue of the SiO(2)-exposed rats. The rats in the control group had a small amount of collagen at 21 and 28 days, but a large amount of collagen fiber deposition began to appear in the lung tissue of rats exposed to SiO(2) after 21 days. Compared with the control group, the expression levels of micro RNA-423-5p was significantly up-regulated and the expression of microRNA-26a-5p was significantly down-regulated in the SiO(2)-exposed rats lung tissues dust at different time points (P<0.05) . Conclusion: The up-regulation of miRNA-423-5p and the down-regulation of miRNA-26a-5p in lung tissues of early silicotic rats may be related to the occurrence and development of early silicosis.

[Repair effect of adipose-derived mesenchymal stem cells on lung injury in rats exposed to silica]

Objective: To observe the repairing effect of adipose mesenchymal stem cells (ADSCs) on lung injury induced by silica in rats. Methods: Primary ADSCs-GFP was obtained from rats. ADSCs-GFP was injected into tail vein of silicosis model rats. The expression of green fluorescence in lungs was observed regularly to determine the homing ability of ADSCs. Primary ADSCs of rats were obtained and randomly divided into control group, exposure group, vehicle group and ADSCs group. Silicosis rat model was established by non-exposed tracheal drip method. 24 hours after silica exposure, rats in ADSCs group were injected with ADSCs of 1×10(6)/kg body weight through tail vein, and the pathological changes of lung tissue were observed and evaluated 28 days after intervention. To explore the early intervention mechanism of ADSCs on pulmonary fibrosis in silicosis model rats, apoptosis-related proteins were detected by immunohistochemistry. Results: 28 days after exposure to silica, rats in the exposure group showed obvious pulmonary fibrosis. Compared with exposure group and vehicle group, ADSCs group showed less pulmonary inflammation, less silica nodules and less collagen deposition area. Immunohistochemical results showed that the expression of Caspase-3 and cytochrome C protein decreased and Bcl-2 protein increased after ADSCs transplantation. Conclusion: ADSCs infusion has an obvious intervention effect on postponing early silicosis fibrosis in rats exposed to silica, and its mechanism is related to the regulation of apoptotic process.

[Research of relationship between occupational exposure to coal tar pitch workers and cytogenetic damage]

Objective: To investigate the effect of coal tar pitch occupational exposure on the cytogenetic damage. Methods: In July 2015, 691 workers exposed to coal tar pitch were selected as contact group. The administrative and the support crew 201 cases were selected as control group. Detect the tail DNA% and tail moment in peripheral blood lymphocyte as DNA damage degree by single cell gel electrophoresis (SCGE) . Detect the concentration of the metabolic product in urine by HPLC/MC as exposure levels. Results: The contact group were significantly higher than the control group in tail DNA% (contact group14.44%, control group 11.17%) and olive tail moment (contact group 2.85 μm, control group 1.95 μm) . The smoking one (contact group18.51%, control group13.43%) were significantly higher than the group not smoking (contact group12.69%, control group 11.71%) in tail DNA%. The coal tar pitch content in the air of workplace have correlation with worker, stail DNA% (r(s)=0.10) and olive tail moment (r(s)=0.11) . Conclusion: Occupational exposure to coal tar pitch and smoking can cause cytogenetic damage to workers.

[A case of systemic lupus erythematosus in pregnancy complicated by pulmonary hypertension]

To investigate the pathophysiology, screening, diagnosis and treatment of the systemic lupus erythematosus (SLE) in pregnancy complicated with pulmonary hypertension. Retrospective analysis was made of one case of SLE in pregnancy complicated with pulmonary hypertension in Peking University Third Hospital. Literature was reviewed to investigate the pathophysiology, screening, diagnosis and treatment of the SLE in pregnancy complicated with pulmonary hypertension. SLE is an autoimmune mediated diffuse connective tissue disease characterized by immunological inflammation. The incidence of SLE combined with pulmonary hypertension was low, but the risk was high with pregnancy, with a high perinatal mortality rate. Pulmonary hypertension is the leading cause of the death in patients with pregnancy complicated with SLE. This patient was diagnosed with SLE six years before and was hospitalized for 29 weeks of menopause, with fatigue five months and chest congestion one month. Ultrasonic cardiogram showed severe pulmonary hypertension, with pulmonary arterial systolic pressure being 96 mmHg. After admission, multidisciplinary consultation was organized to draw up a diagnosis and treatment plan. The patient received the treatment of rest,oxygen,blood gas and pulmonary artery pressure monitoring. Considering perioperative pulmonary hypertension crisis likely to occur, pulmonary artery catheter was placed preoperatively. In general anesthesia, the cesarean was performedfter operation,the patient was transferred to the intensive care unit, with the treatment of expanding blood vessels, reducing pulmonary artery pressure,administering anticoagulation and preventing infection. Ten days after operation, the patient was discharged from hospital with smooth condition. Strengthening the management of SLE patients in pregnancy, early detection, and cooperation of multidisciplinary teams can help improve maternal and fetal outcomes. Termination of pregnancy should be offered to the patients with severe pulmonary hypertension. Right cardiac catheterization is the gold standard for diagnosing pulmonary hypertension. Some patients are diagnosed in later stage of pregnancy, regular antenatal examination, interdisciplinary co-operation, assessment of cardiac function, monitoring the condition of the pregnant woman and fetus and timely termination of pregnancy are needed. Epidural anesthesia is the appropriate choice for cesarean delivery.

Protective influence of rosiglitazone against testicular ischaemia-reperfusion injury in rats

Testicular torsion is a urology urgent disease which causes testicular injury and potential sterility. In this study, we explored the protective influence of rosiglitazone on testicular ischaemia-reperfusion damage. There were 28 male Sprague Dawley rats in total, which were assigned randomly to four groups. Group A was blank control one; group B was testicular injury one; group C was rosiglitazone one; group D was rosiglitazone antagonist one. The testicles were counter-rotated after 2 hr and then underwent orchiectomy 24 hr later. We found that testicular tissue structure of rats was seriously damaged in groups B and D. However, group C had better testicular architecture. Similar findings were also shown for lipid peroxidation by evaluating the MDA activity (p < .05). Unlike group B or group D, the levels of inflammation by evaluating the MPO activity, the levels of TNF-a, IL-1 and IL-6 and the expressions of ICAM-1 were prominently lower in group C (p < .05) as well. So our researches demonstrated that rosiglitazone significantly decreased the amount of responsive oxygen radical and regulated inflammatory responses. Rosiglitazone had a protective influence against testicular ischaemia-reperfusion injury in rats and possibly depended on its anti-inflammatory and antioxidant traits.

Custom Repair of Mandibular Bone Defects with 3D Printed Bioceramic Scaffolds

Implanting artificial biomaterial implants into alveolar bone defects with individual shape and appropriate mechanical strength is still a challenge. In this study, bioceramic scaffolds, which can precisely match the mandibular defects in macro and micro, were manufactured by the 3-dimensional (3D) printing technique according to the computed tomography (CT) image. To evaluate the stimulatory effect of the material substrate on bone tissue regeneration in situ in a rabbit mandibular alveolar bone defect model, implants made with the newly developed, mechanically strong ~10% Mg-substituted wollastonite (Ca_90%Mg_10%SiO₃; CSi-Mg10) were fabricated, implanted into the bone defects, and compared with implants made with the typical Ca-phosphate and Ca-silicate porous bioceramics, such as β-tricalcium phosphate (TCP), wollastonite (CaSiO₃; CSi), and bredigite (Bred). The initial physicochemical tests indicated that although the CSi-Mg10 scaffolds had the largest pore dimension, they had the lowest porosity mainly due to the significant linear shrinkage of the scaffolds during sintering. Compared with the sparingly dissolvable TCP scaffolds (~2% weight loss) and superfast dissolvable (in Tris buffer within 6 wk) pure CSi and Bred scaffolds (~12% and ~14% weight loss, respectively), the CSi-Mg10 exhibited a mild in vitro biodissolution and moderate weight loss of ~7%. In addition, the CSi-Mg10 scaffolds showed a considerable initial flexural strength (31 MPa) and maintained very high flexural resistance during soaking in Tris buffer. The in vivo results revealed that the CSi-Mg10 scaffolds have markedly higher osteogenic capability than those on the TCP, CSi, and Bred scaffolds after 16 wk. These results suggest a promising potential application of customized CSi-Mg10 3D robocast scaffolds in the clinic, especially for repair of alveolar bone defects.

Three-dimensional ultrashort echo time cones T1ρ (3D UTE-cones-T1ρ ) imaging

We report a novel three-dimensional (3D) ultrashort echo time (UTE) sequence employing Cones trajectory and T_1ρ preparation (UTE-Cones-T_1ρ ) for quantitative T_1ρ assessment of short T₂ tissues in the musculoskeletal system. A basic 3D UTE-Cones sequence was combined with a spin-locking preparation pulse for T_1ρ contrast. A relatively short TR was used to decrease the scan time, which required T₁ measurement and compensation using 3D UTE-Cones data acquisitions with variable TRs. Another strategy to reduce the total scan time was to acquire multiple Cones spokes (N_sp ) after each T_1ρ preparation and fat saturation. Four spin-locking times (TSL = 0-20 ms) were acquired over 12 min, plus another 7 min for T₁ measurement. The 3D UTE-Cones-T_1ρ sequence was compared with a two-dimensional (2D) spiral-T_1ρ sequence for the imaging of a spherical CuSO₄ phantom and ex vivo meniscus and tendon specimens, as well as the knee and ankle joints of healthy volunteers, using a clinical 3-T scanner. The CuSO₄ phantom showed a T_1ρ value of 76.5 ± 1.6 ms with the 2D spiral-T_1ρ sequence, as well as 85.7 ± 3.6 and 89.2 ± 1.4 ms for the 3D UTE-Cones-T_1ρ sequences with N_sp of 1 and 5, respectively. The 3D UTE-Cones-T_1ρ sequence provided shorter T_1ρ values for the bovine meniscus sample relative to the 2D spiral-T_1ρ sequence (10-12 ms versus 16 ms, respectively). The cadaveric human Achilles tendon sample could only be imaged with the 3D UTE-Cones-T_1ρ sequence (T_1ρ  = 4.0 ± 0.9 ms), with the 2D spiral-T_1ρ sequence demonstrating near-zero signal intensity. Human studies yielded T_1ρ values of 36.1 ± 2.9, 18.3 ± 3.9 and 3.1 ± 0.4 ms for articular cartilage, meniscus and the Achilles tendon, respectively. The 3D UTE-Cones-T_1ρ sequence allows volumetric T_1ρ measurement of short T₂ tissues in vivo.

Measurement of bound and pore water T1 relaxation times in cortical bone using three-dimensional ultrashort echo time cones sequences

PURPOSE

We present three-dimensional ultrashort echo time Cones (3D UTE Cones) techniques for quantification of total water T1 ( T1TW), bound water T1 ( T1BW), and pore water T1 ( T1PW) in vitro and in vivo using a 3 Tesla (T) scanner.

METHODS

T1TW, T1BW, and T1PW were measured with three-dimensional (3D) Cones and adiabatic inversion recovery Cone (IR-Cone) sequences. Two-dimensional (2D) nonselective ultrashort echo time (UTE) techniques, including saturation recovery, variable repetition times (TRs), and inversion recovery (IR) preparation approaches were compared with 3D-Cones techniques on bovine cortical bone samples (n = 8). The 3D Cones sequences were used to measure T1TW, T1BW, and T1PW in the tibial midshaft of healthy volunteers (n = 8).

RESULTS

Comparable T1 images were achieved for cortical bone between 3D Cones and 2D UTE techniques as well as those published in the literature. The 3D Cones sequences showed a mean T1TW of 208 ± 22 ms, a mean T1PW of 545 ± 28 ms, and a mean T1BW of 131 ± 12 ms for bovine cortical bone; and a mean T1TW of 246 ± 32 ms, a mean T1PW of 524 ± 46 ms, and a mean T1BW of 134 ± 11 ms for the tibial midshaft of healthy volunteers.

CONCLUSIONS

The 3D Cones sequences can be used for fast volumetric assessment of bound and pore water T1 images in vitro and in vivo. Magn Reson Med 77:2136-2145, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

Changing nitrogen deposition with low δ15N−NH4 + and δ15N−NO3 − values at the Experimental Lakes Area, northwestern Ontario, Canada

Ammonium deposition at the International Institute for Sustainable Development Experimental Lakes Area (IISD–ELA), in northwestern Ontario, Canada, has doubled in the last 45 years and thus is no longer among the low nitrogen (N) deposition sites in North America. This may be related to the concurrent intensification of Manitoba agriculture to the west and upwind of the ELA. Large increases in ammonium deposition at the ELA were important in driving the observed trend and increased the NH4 + to NO3 − ratio of input to aquatic and terrestrial systems. Stable isotope analyses of two years of bulk (wet and dry) atmospheric deposition revealed very large ranges in δ15N−NH4 + (22‰ range), δ15N−NO3 − (18‰), and δ18O–NO3 − (19‰). Few other δ15N−NH4 +, δ15N−NO3 −, and δ18O–NO3 − values have been published for Canadian precipitation. Increases in δ15N of NH4 + and NO3 − in July occurred with increases in total N deposition. The wide range and seasonal trends of δ15N and δ18O values in ELA precipitation mean that studies characterizing N inputs to watersheds and lakes require an ongoing and comprehensive annual sampling regime. Global trends of declining δ15N of N deposition evident in lake sediment records may be a result of increases in NH4 + deposition with lower δ15N−NH4 + values. Similarly, the relationship in Lake Superior between increasing NO3 − and lower δ15N−NO3 − values may be explained by increased atmospheric deposition of N with low δ15N values.

[Analysis of inner or extra-exposure for worker in carbon and coal tar process industries]

Objective: To evaluate the inner or extra-exposure of workers in carbon and coal tar process industries. Methods: In May 2015, 271 exposure and 75 non-exposure workers in two of carbon and coal tar process industries in Shandong province were selected. Coal tar pitch (CTP) was detected according to the methods of GB17054-1997. The 1-OH-Nap、2-OH-Nap、1-OH-Pyr in urine were detected by high performance liquid Chromatography (HPLC) . Results: The concentration of 1-OH-Nap、2-OH-Nap、1-OH-Pyr in urine of exposure group were significant higher than that of control group (P<0.05) , respectively. The urine concentration of 1-OH-Nap、2-OH-Nap、1-OH-Py in contact group tar and asphalt were 12.20, 12.55, 7.08 and 10.62, 8.73, 3.07 μg/gCr, and the concentration of them were 7.25, 8.54, 3.00 μg/gCr in container handle workers. Significant positive correlations were found between high or median CTP exposure and the urine concentration of 1-OH-Nap、2-OH-Nap、1-OH-Pyr in exposure groups (P<0.05) . Conclusions: The inner or extra exposure level is relative and different for different type of work in these carbon and coal tar process industries.

Transgenesis in Strongyloides and related parasitic nematodes: historical perspectives, current functional genomic applications and progress towards gene disruption and editing

Transgenesis for Strongyloides and Parastrongyloides was accomplished in 2006 and is based on techniques derived for Caenorhabditis elegans over two decades earlier. Adaptation of these techniques has been possible because Strongyloides and related parasite genera carry out at least one generation of free-living development, with adult males and females residing in soil contaminated by feces from an infected host. Transgenesis in this group of parasites is accomplished by microinjecting DNA constructs into the syncytia of the distal gonads of free-living females. In Strongyloides stercoralis, plasmid-encoded transgenes are expressed in promoter-regulated fashion in the F1 generation following gene transfer but are silenced subsequently. Stable inheritance and expression of transgenes in S. stercoralis requires their integration into the genome, and stable lines have been derived from integrants created using the piggyBac transposon system. More direct investigations of gene function involving expression of mutant transgene constructs designed to alter intracellular trafficking and developmental regulation have shed light on the function of the insulin-regulated transcription factor Ss-DAF-16. Transgenesis in Strongyloides and Parastrongyloides opens the possibility of powerful new methods for genome editing and transcriptional manipulation in this group of parasites. Proof of principle for one of these, CRISPR/Cas9, is presented in this review.

Direct magnitude and phase imaging of myelin using ultrashort echo time (UTE) pulse sequences: A feasibility study

In this paper, we aimed to investigate the feasibility of direct visualization of myelin, including myelin lipid and myelin basic protein (MBP), using two-dimensional ultrashort echo time (2D UTE) sequences and utilize phase information as a contrast mechanism in phantoms and in volunteers. The standard UTE sequence was used to detect both myelin and long T2 signal. An adiabatic inversion recovery UTE (IR-UTE) sequence was used to selectively detect myelin by suppressing signal from long T2 water protons. Magnitude and phase imaging and T2* were investigated on myelin lipid and MBP in the forms of lyophilized powders as well as paste-like phantoms with the powder mixed with D₂O, and rubber phantoms as well as healthy volunteers. Contrast to noise ratio (CNR) between white and gray matter was measured. Both magnitude and phase images were generated for myelin and rubber phantoms as well white matter in vivo using the IR-UTE sequence. T2* values of ~300μs were comparable for myelin paste phantoms and the short T2* component in white matter of the brain in vivo. Mean CNR between white and gray matter in IR-UTE imaging was increased from -7.3 for the magnitude images to 57.4 for the phase images. The preliminary results suggest that the IR-UTE sequence allows simultaneous magnitude and phase imaging of myelin in vitro and in vivo.

Mechanistic insights for the photoredox organocatalytic fluorination of aliphatic carbons by anthraquinone using time-resolved and DFT studies

Nanosecond TAS and DFT calculations reveal mechanistic insights for photoredox fluorination of aliphatic C–H bonds and evidence of an anthraquinone–Selectfluor® exciplex.

[Effects of genetic polymorphisms of GSTT1 and GSTM1 on metabolism of Polycyclic aromatic hydrocarbon in coal tar pitch workers]

Objective: To investigate the influence of genetic polymorphisms of GSTT1 and GSTM1 on metabolism of polycyclic aromatic hydrocarbon (PAHs) in coal tar pitch workers and to explore the effective bio-marker of occupational exposure to coal tar pitch. Methods: 374 cases of workers exposed to coal tar pitch work at the enterprise which use and product coal tar pitch in Shan Dong province named as exposure group.The ad-ministrative and the support staff 135 cases were selected as control group.The concentration of the metabolic product in urine by HPLC/MC.The genetic polymorphisms of GSTT1 and GSTM1 were detected by multiple PCR method. Results: The content of metabolic product in smoke group were significantly higher than workers do not smoke (P<0.05) . The content of metabolic product in exposure group were significantly higher than control group (P<0.05) . The content of metabolic product in workers carry positive GSTT1 and GSTM1 were significantly high-er than workers carry negative one (P<0.05) . The content of metabolic product in different types of labor were significantly different (P<0.05) . The content of metabolic product were significantly higher in urine after work than before work (P<0.05) . The content of metabolic product and workers carry positive GSTT1 and GSTM1 had a positive correlation (P<0.05) . Conclusion: Carrying positive GSTT1 and GSTM1 promote polycyclic aromatic hydrocarbons in the body's metabolism.

[The effect of occupational exposure to coal tar pitch workers' health]

Objective: To investigate the effect of occupational exposure to coal tar pitch on workers' health and metabolism. Methods: 805 workers exposed to coal tar pitch were selected as exposure group from the produce and em-ploy factory. Other people handle administrative and logistical affairs who not exposed to coal tar pitch were selected as control group. Fix-point sample of air were collected to detect the concentration of coal tar pitch. Do physical examination and questionnaire to collect workers' basic and healthy information. To detect the metabolic product of urine samples in laboratory. Results: Anomaly detection rate of the skin in exposure group is 10.61. The lung function indices (FEV_1.0%) in exposure group were significantly lower than control group (P<0.05) . The monocyte count and monocyte rate in expo-sure group were significantly higher than control group (P<0.05) . The metabolic product content of PAHS in urine sam-ples is significantly higher in exposed group than control group (P<0.05) . Conclusion: The metabolic product content of polycyclic aromatic hydrocarbon is higher in exposed workers. Coal tar pitch damage workers' skin and lung function. It can cause pruritus chromatodermatosis and so on.