Robust engraftment of fetal nonhuman primate CD34-positive cells in immune-deficient mice

Nonhuman primates (NHPs) represent one of the most important models for preclinical studies of novel biomedical interventions. In contrast with small animal models, however, widespread utilization of NHPs is restricted by cost, logistics, and availability. Therefore, we sought to develop a translational primatized mouse model, akin to a humanized mouse, to allow for high-throughput in vivo experimentation leveraged to inform large animal immunology-based studies. We found that adult rhesus macaque mobilized blood (AMb) CD34+-enriched hematopoietic stem and progenitor cells (HSPCs) engrafted at low but persistent levels in immune-deficient mice harboring transgenes for human (NHP cross-reactive) GM-CSF and IL3, but did not in mice with wild-type murine cytokines lacking NHP cross-reactivity. To enhance engraftment, fetal liver-derived HSPCs were selected as the infusion product based on an increased CD34hi fraction compared with AMb and bone marrow. Coupled with cotransplantation of rhesus fetal thymic fragments beneath the mouse kidney capsule, fetal liver-derived HSPC infusion in cytokine-transgenic mice yielded robust multilineage lymphohematopoietic engraftment. The emergent immune system recapitulated that of the fetal monkey, with similar relative frequencies of lymphocyte, granulocyte, and monocyte subsets within the thymic, secondary lymphoid, and peripheral compartments. Importantly, while exhibiting a predominantly naïve phenotype, in vitro functional assays demonstrated robust cellular activation in response to nonspecific and allogenic stimuli. This primatized mouse represents a viable and translatable model for the study of hematopoietic stem cell physiology, immune development, and functional immunology in NHPs. Summary Sentence: Engraftment of rhesus macaque hematopoietic tissues in immune-deficient mice yields a robust BLT/NeoThy-type primatized mouse model for studying nonhuman primate hematopoiesis and immune function in vivo.

A new Kirkpatrick-Baez-based scanning microscope for the Submicron Resolution X-ray Spectroscopy (SRX) beamline at NSLS-II

The development, construction, and first commissioning results of a new scanning microscope installed at the 5-ID Submicron Resolution X-ray Spectroscopy (SRX) beamline at NSLS-II are reported. The developed system utilizes Kirkpatrick-Baez mirrors for X-ray focusing. The instrument is designed to enable spectromicroscopy measurements in 2D and 3D with sub-200 nm spatial resolution. The present paper focuses on the design aspects, optical considerations, and specifics of the sample scanning stage, summarizing some of the initial commissioning results.

Effects of deoxynivalenol on the histomorphology of the liver and kidneys and the expression of MAPKs in weaned rabbits

Deoxynivalenol (DON) is widely present in grain-based feeds and food. It has attracted great attention due to its high contamination rate and strong toxicity. The objective of this study was to analyse the toxic effects of DON on the liver and kidneys of weaned rabbits. 45 weaned male rabbits were allocated into control, low DON dose (0.5 mg/kg body weight), and high DON dose (1.5 mg/kg body weight) groups. Saline or DON was administrated intragastrically in the empty stomach of rabbits every morning. After 24 days of treatment, liver and kidney samples were collected for histological, reverse transcription-quantitative polymerase chain reaction (qRT-PCR), and immunohistochemistry analyses. Haematoxylin eosin staining showed that 0.5 mg/kg BW DON caused mild damage to the liver and kidney morphology, while 1.5 mg/kg body weight DON resulted in hepatic vacuolation and necrosis, as well as tubular stenosis and lesions. Data from qRT-PCR, Western blot, and immunohistochemistry revealed that the mRNA and protein expression and the distribution range of extracellular signal-regulated kinase, p38, and c-Jun NH2-terminal kinase were increased in the liver and kidneys. In conclusion, DON at the tested concentrations damaged the liver and kidneys of rabbits by affecting the expression of key proteins from the mitogen-activated protein kinase signalling pathway. The damage extent was proportional to the amount of DON ingested.

SuperSonic shear imaging for the differentiation between benign and malignant thyroid nodules: a meta-analysis

PURPOSE

To assess the diagnostic value of SuperSonic shear imaging (SSI) for the differentiation between benign and malignant thyroid nodules through meta-analysis.

METHODS

Online database searches were performed on PubMed, EMBASE, the Cochrane Library, and the Web of Science until 31 July 2021. The Quality Assessment of Diagnostic Accuracy Studies-2 tool was used to assess the quality of the included studies. Three measures of diagnostic test performance were used to examine the value of SSI, including the summary area under the receiver operating characteristic curve (AUROC), the summary diagnostic odds ratio (DOR), and the summary sensitivity and specificity. Heterogeneity was explored using meta-regression and subgroup analyses.

RESULTS

Finally, 21 studies with 3376 patients were included in this study. There were a total of 4296 thyroid nodules, in which 1806 malignant nodules and 2490 benign ones were involved. Thyroid nodules exhibited a malignancy rate of 42.0% (range 5.6-79.8%), 95.1% of which were of papillary variant. SSI showed a summary sensitivity of 74% [95% confidence interval (CI) 67-79%], specificity of 82% (95% CI 77-87%) and AUROC of 0.85 (95% CI 0.82-0.88) for the differentiation between benign and malignant thyroid nodules. The summary positive likelihood ratio (LR), negative LR, and DOR were 4.2 (95% CI 3.3-5.3), 0.32 (95% CI 0.26-0.40), and 13 (95% CI 9-18), respectively.

CONCLUSIONS

SSI showed high accuracy in the diagnostic differentiation between benign and malignant thyroid nodules and can be served as a noninvasive and important adjunct for thyroid nodule evaluation.

Retention of Intrafibrillar Minerals Improves Resin-Dentin Bond Durability

The concept of extrafibrillar demineralization involves selective removal of apatite crystallites from the extrafibrillar spaces of mineralized dentin without disturbing the intrafibrillar minerals within collagen. This helps avoiding activation of endogenous proteases and enables air-drying of partially demineralized dentin without causing collapse of completely demineralized collagen matrix that adversely affects resin infiltration. The objective of the present study was to evaluate the potential of quaternized carboxymethyl chitosan (QCMC)-based extrafibrillar demineralization in improving resin-dentin bond durability. Isothermal titration calorimetry indicated that QCMC synthesized by quaternization of O-carboxymethyl chitosan had moderate affinity for Ca²⁺ (binding constant: 8.9 × 10⁴ M^-1). Wet and dry bonding with the QCMC-based demineralization produced tensile bond strengths equivalent to the phosphoric acid (H₃PO₄)-based etch-and-rinse technique. Those bond strengths were maintained after thermocycling. Amide I and PO₄^3- mappings of QCMC-conditioned dentin were performed with atomic force microscope-infrared spectroscopy (AFM-IR). Whereas H₃PO₄-etched dentin exhibited an extensive reduction in PO₄^3- signals corresponding to apatite depletion, QCMC-conditioned dentin showed scattered dark areas and bright PO₄^3- streak signals. The latter were consistent with areas identified as collagen fibrils in the amide I mapping and were suggestive of the presence of intrafibrillar minerals in QCMC-conditioned dentin. Young's modulus mapping of QCMC-demineralized dentin obtained by AFM-based amplitude modulation-frequency modulation recorded moduli that were the same order of magnitude as those in mineralized dentin and at least 1 order higher than H₃PO₄-etched dentin. In situ zymography of the gelatinolytic activity within hybrid layers created with QCMC conditioning revealed extremely low signals before and after thermocycling, compared with H₃PO₄-etched dentin for both wet and dry bonding. Confocal laser scanning microscopy identified the antibacterial potential of QCMC against Streptococcus mutans and Enterococcus faecalis biofilms. Taken together, the QCMC-based demineralization retains intrafibrillar minerals, preserves the elastic modulus of collagen fibrils, reduces endogenous proteolytic activity, and inhibits bacteria biofilms to extend dentin bond durability.

POS0978 LUMBAR FACET JOINTS ARTHRITIS RELATES TO ITS ADJACENT MRI INFLAMMATORY LESIONS IN AXIAL SPONDYLOARTHRITIS

Background

Facet joints are frequently impaired in patients with axial spondyloarthritis (axSpA), which raises high disease activity and poor physical function. However, insufficient attention is paid to the relationship between the feature of disease and facet joint arthritis (FJA) in magnetic resonance imaging (MRI) examination, because of lacking an ideal assessment tool. The Canada-Denmark (CANDEN) MRI scoring system is adopted in our study because it is a comprehensive method to assess the alteration of spine [1].

Objectives

We aimed to find relevant factors for lumbar FJA in axSpA patients.

Methods

This was a cross-sectional study that analyzed the lumbar MRI of axSpA patients using the CANDEN system. Demographic and clinical information was recorded. Univariate and multivariate linear mixed model (LMM) was used to screen related factors for lumbar FJA in MRI examinations.

Results

(1) Totally 108 axSpA patients were investigated in our study, while ankylosing spondylitis (AS) and non-radiographic axSpA (nr-axSpA) accounted for half respectively. Sixty-five (60.19%) participants were male and their median age was 35 years. (2) Twenty (37.10%) and 1 (1.80%) AS and nr-axSpA suffered lumbar FJA (P<0.05). (3) Univariate LMM found gender, vertebral body corner inflammation subscore (VBCIS), spondylodiscitis subscore (SDS), posterolateral elements inflammation subscore (PLEIS), fat posterior elements subscore (FPES), fat vertebral body subscore (FVBS), and AS disease activity score with C-reactive protein (ASDAS) related to lumbar FJA in AS patients. Besides, gender, the duration of symptom, peripheral arthritis, enthesitis, non-steroidal anti-inflammatory drugs, VCBIS, SDS, PLEIS, FPES, the ankylosis of sacroiliac joints, and bony erosion of hips were involved in the univariate LMM for nr-axSpA. (4) Multivariate LMM displayed that odd ratio (OR) and 95% confidence intervals (CI) of PLEIS, FPES, and ASDAS were 0.66 (0.40, 0.91), 0.45 (0.20, 0.71), and 0.23 (0.01, 0.44) (P<0.05). OR (95%CI) for VBCIS and PLEIS were 0.02 (0.00, 0.04) and 0.23 (0.16, 0.30) in nr-axSpA patients (P<0.05).

Conclusion

Prevalence of lumbar FJA is higher in AS patients than nr-axSpA. This lesion is mainly related to MRI changes of its neighborhood structure, especially inflammatory alterations, rather than demographic and clinical characteristics.

References

[1]Krabbe S, Østergaard M, Pedersen SJ, et al. Canada-Denmark MRI scoring system of the spine in patients with axial spondyloarthritis: updated definitions, scoring rules and inter-reader reliability in a multiple reader setting. RMD Open. 2019;5(2):e001057.

Disclosure of Interests

None declared

AB0228 THE CONNECTION BETWEEN NUTRITIONAL STATUS AND DISEASE ACTIVITY IN RHEUMATOID ARTHRITIS

Background

Nutritional status is closely associated with a person’s physical condition. As for patients with autoimmune disease, nutritional status may affect the balance of immune system, which successively affects disease activity.

Objectives

The prognostic nutritional index (PNI), nutritional risk index (NRI), controlling nutritional status (CONUT) score and body mass index (BMI) are four widely used nutritional indices [1]. This study aimed to investigate the relationship between nutritional status and disease activity of rheumatoid arthritis (RA).

Methods

168 RA patients and 50 healthy volunteers were retrospectively enrolled. According to the disease activity score using 28 joint counts-erythrocyte sedimentation rate (DAS28-ESR), the cohort of RA patients was divided into the lower disease activity groups (DAS28-ESR≤3.2) and the higher disease activity groups (DAS28-ESR>3.2). We recorded clinical assessment and laboratory data for further analysis. Spearman’s correlation, receiver operation characteristic (ROC) curves, binary logistic regression analysis were carried out.

Results

Compared to the higher disease activity group, the lower disease activity group had low-level total protein (TP), ESR and CRP (all P<0.05), while high-level albumin and PNI (all P<0.05). PNI and NRI were negatively correlated with DAS28-ESR (r=-0.395, and r=-0.200, all P<0.05), while CONUT score was positively correlated with DAS28-ESR (r=0.324, P<0.05). ROC curve illustrated that area under the curve (AUC) of PNI for RA patients with higher disease activity was superior to NRI, CONUT score and BMI. The AUC of PNI was 0.693.

Figure 1.

The diagnostic value of variables for disease activity in rheumatoid arthritis using ROC curve

Table 1.

The correlation between nutritional indices and disease activity score using 28 joint counts-erythrocyte sedimentation rate (DAS28-ESR)

PNINRICONUT scoreBMIrP valuerP valuerP valuerP valueNeutrophil(×109/L)-0.0610.4340.0450.5680.0250.7570.0790.313Monocyte(×109/L)0.1830.1630.1450.064-0.1040.1930.1520.052Lymphocyte(×109/L)0.4720.0000.2010.010-0.4360.0000.2080.007ESR (mm/h)-0.5610.000-0.2580.0010.3930.000-0.1820.020CRP (mg/L)-0.5200.000-0.0770.3260.3910.0000.0030.967RF(IU/ml)-0.2240.004-0.1160.1510.2600.001-0.0820.306CCP(IU/ml)-0.1390.088-0.2010.0140.1950.018-0.1880.022DAS28-ESR-0.3950.000-0.2000.0110.3240.000-0.1420.072

Conclusion

PNI may become a manageable marker for detector disease activity of RA patients.

References

[1]Ahn, S.S., et al., Comparison of the Clinical Implications among Five Different Nutritional Indices in Patients with Lupus Nephritis. Nutrients, 2019. 11(7).

Disclosure of Interests

None declared

Hydrogen sulphide regulates the growth of tomato root cells by affecting cell wall biosynthesis under CuO NPs stress

Copper oxide nanoparticles (CuO NPs) show strong nano-toxic effects on organisms. Hydrogen sulphide (H₂ S) plays a pivotal role in plant response to abiotic stress. In this study, we examine the crucial role of the cell wall as regulated by H₂ S in response to CuO NPs stress. The digestion method was employed to determine Cu content using atomic absorption spectrometry. The TraKine pro-tubulin staining kit was used to investigate the microtubule cytoskeleton using confocal laser-scanning microscopy. Cell wall component analysis utilized the ICS-3000 HPLC system. Application of H₂ S reduced growth inhibition caused by CuO NPs. Furthermore, most of the CuO NPs accumulates in roots, indicating a low transfer rate, and H₂ S significantly decreased CuO NPs content in roots, leaves and stems. Subcellular distribution analysis implied most Cu accumulated in root cell walls, and that H₂ S reduced the content of Cu in root cell walls. Cortical microtubules in the plasma membrane, guide cell wall biosynthesis. H₂ S obviously alleviated microtubule cytoskeleton disorders caused by CuO NPs. In addition, the content of cellulose, hemicellulose, pectin and other monosaccharides in root cell walls was reduced by CuO NPs treatment. H₂ S enhanced the monosaccharide and polysaccharide contents compared with that after CuO NPs treatment. In conclusion, H₂ S regulates cell wall development in response to CuO NPs stress by stabilizing microtubules. H₂ S affected Cu distribution and alleviated growth inhibition of tomato seedlings. The research results provide a theoretical basis for further study of nano-toxicity regulation in plants.

[Experience and thoughts on digestive tract reconstruction after radical resection of adenocarcinoma of the esophagogastric junction]

In the surgical treatment of adenocarcinoma of the esophagogastric junction (AEG), the scope of lymph node dissection, surgical approach selection, extent of tumor resection and digestive tract reconstruction have always been controversial, with the digestive tract reconstruction in AEG facing many challenges especially. The digestive tract reconstruction is related to the extent of resection. At present, the digestive tract reconstruction after total gastrectomy includes Roux-en-Y anastomosis, jejunum interposition and its derivatives. According to different reconstruction methods, they can be divided into tube anastomosis, linear anastomosis and manual anastomosis. Anti-reflux digestive tract reconstruction after proximal gastrectomy mainly includes esophagogastric anastomosis, interposition jejunum and double channel anastomosis. At present, double channel anastomosis is the most common reconstruction method in China. Based on the concept of interposition tubular stomach and reconstruction of gastric angle for anti-reflux, we propose "Giraffe" anastomosis, which moves artificial fundus and His angle downward to retain more residual stomach, showing good gastric emptying and anti-reflux effect. In this paper, combined with our clinical experience and understanding, we discuss the selection and technical key points of digestive tract reconstruction methods in AEG, and suggest that composite anti-reflux mechanism design may be the development trend of anti-reflux reconstruction in the future. The composite mechanism includes the retention of gastric electrical pacemaker in greater curvature of the middle part of gastric body to increase the emptying capacity of residual stomach, the reconstruction of gastric fundus and His angle anti-reflux barrier, and the establishment of an interposition tubular stomach acting as a buffer zone in Giraffe construction, and so on.

[Functional outcomes of 100 patients with adenocarcinoma of the esophagogastric junction undergoing Cheng's GIRAFFE(®) reconstruction after proximal gastrectomy]

Objective: To investigate the functional outcomes and postoperative complications of Cheng's GIRAFFE reconstruction after proximal gastrectomy. Methods: A descriptive case series study was conducted. Clinical data of 100 patients with adenocarcinoma of the esophagogastric junction who underwent Cheng's GIRAFFE reconstruction after proximal gastrectomy in Cancer Hospital of University of Chinese Academy of Sciences (64 cases), Zhejiang Provincial Hospital of Chinese Medicine (24 cases), Lishui Central Hospital (10 cases), Huzhou Central Hospital (1 case) and Ningbo Lihuili Hospital (1 case) from September 2017 to June 2021 were retrospectively analyzed. Of 100 patients, 64 were males and 36 were females; the mean age was (61.3 ± 11.1) years and the BMI was (22.7±11.1) kg/m(2). For TNM stage, 68 patients were stage IA, 24 were stage IIA and 8 were stage IIB. Postoperative functional results and postoperative complications of radical gastrectomy with Giraffe reconstruction were analyzed and summarized. Gastroesophageal reflux disease questionnaire (RDQ) score and postoperative endoscopy were used to evaluate the occurrence of reflux esophagitis and its grade (grade N, grade A, grade B, grade C, and grade D from mild to severe reflux). The continuous data conforming to normal distribution were expressed as (mean ± standard deviation), and those with skewed distribution were presented as median (Q1, Q3). Results: All the 100 patients successfully completed R0 resection, including 77 patients undergoing laparoscopic surgery and 23 patients undergoing laparotomy. The Giraffe anastomosis time was (38.6±14.0) min; the blood loss was (73.0±18.4) ml; the postoperative hospital stay was 9.5 (8.2, 13.0) d; the hospitalization cost was (6.0±0.3) ten thousand yuan. Fourteen cases developed perioperative complications (14.0%), including 7 cases of pleural effusion or pneumonia, 3 cases of anastomotic leakage, 2 cases of gastric emptying disorder, 1 case of gastrointestinal hemorrhage and 1 case of anastomotic stenosis, who were all improved and discharged after symptomatic management. Patients were followed up for (33.3±1.6) months. Eight patients were found to have reflux symptoms by RDQ scale six months after surgery, and 11 patients (11/100,11.0%) were found to have reflux esophagitis by gastroscopy, including 6 in grade A, 3 in grade B, and 2 in grade C. All the patients could control their reflux symptoms with behavioral guidance or oral PPIs. Conclusion: Cheng's GIRAFFE reconstruction has good anti-reflux efficacy and gastric emptying function; it can be one of the choices of reconstruction methods after proximal gastrectomy.

[Postoperative rehabilitation effect and influence factors of adult prelingual deafness with cochlear implant]

Objective: To investigate whether pre-lingual deafness adult caused by inadequate auditory compensation in childhood can benefit from cochlear implants and the related influencing factors. Methods: A total of 26 prelingual deafness as experimental group [11 males and 15 females, the age of operation was (24.5±5.7) years] and 13 postlingual deafness as control group [5 males and 8 females, the age at the time of operation was (42.2±11.4) years] were recruited. Objective assessment included hearing threshold and speech recognition rate tests while wearing cochlear implants. Subjective assessment used Nijmegen Cochlear Implant Questionnaire to assess hearing-related quality of life of subjects. The changes of hearing ability in the prelingual deafness group before and after operation and the differences with the postlingual deafness group were compared, and the correlation between speech recognition ability and the age diagnosed as severe or profound deafness, the age of hearing aid invalid, and duration of wearing cochlear implant were analyzed as factor indicators. All statistical results were analyzed by SAS 9.4 software. Results: In terms of objective indicators, the speech recognition rate of pre-lingual deafness was significantly lower than that of post-lingual deafness [(35.4±28.0)% vs (80.9±8.0)%,t=7.67, P<0.001], while there was no statistical difference in hearing threshold between the two groups [(34.8±4.0) dB HL vs (33.1±3.7) dB HL, t=1.30, P>0.05]. The indicators in the subjective questionnaire showed that the prelingual deafness group was only weaker in advanced sound perception, confidence and total mean score than the post-lingual deafness group (P<0.05), and there was no significant difference in other aspects(P>0.05), meanwhile, all indicators of the prelingual deafness group were significantly improved compared with the preoperative level (P<0.001). There was a moderate positive correlation between the hearing quality and the speech recognition rate in the prelingual deafness group(r=0.51, P=0.008). The regression analysis showed that the invalid age of hearing aid was the exact influencing factor of speech recognition rate. Conclusions: Certain prelingual deaf adults can adapt to cochlear implants and obtain different degrees of auditory assistance. Compared with the improvement of objective auditory ability assessment, the patient who received cochlear implantation gain more improvement in auditory related quality of life subjectively. The ineffective age of preoperative hearing aid is an important factor, which needs to be aroused sufficient preoperative attention.

[A case with severe neurocysticercosis]

This case report described the diagnosis and treatment of an ethnic Tibetan case with severe neurocysticercosis residing in agricultural areas of Sichuan province.

Erratum: Using Diffuse Scattering to Observe X-Ray-Driven Nonthermal Melting [Phys. Rev. Lett. 126, 015703 (2021)]

This corrects the article DOI: 10.1103/PhysRevLett.126.015703.

Functional recovery after discharge in enhanced recovery video-assisted thoracoscopic lobectomy: a pilot prospective cohort study

Little is known about functional recovery following patient discharge in an established enhanced recovery programme after video-assisted thoracoscopic lobectomy. We conducted a single-centre pilot prospective observational cohort study. We hypothesised that patients achieved early functional recovery after discharge. A total of 32 patients aged ≥ 18 years were enrolled. A digital device was used for objective activity measurements, and patient-reported outcomes were collected as subjective measurements. Primary outcomes were the difference in physical activity; sleep duration; pain; fatigue; and average quality of life scores between pre-operative baseline and 7 days following discharge. The secondary outcome was the reason for reduced daily activity during the first 7 days after discharge. Median (IQR [range]) length of stay was 3 (2-5 [1-13]) days. Up to post-discharge day 7, total, lower intensity and moderate-to-vigorous activities were lower than pre-operative activity (p < 0.001; p = 0.005 and p = 0.027, respectively). Numerical rating scale (0-10) pain scores increased postoperatively at rest (mean difference 1.2, p < 0.001) and during walking (mean difference 1.4, p < 0.001). Fatigue assessed by the Christensen Fatigue Scale (1-10) was also increased postoperatively (mean difference 1.7, p = 0.001). There was a reduction in quality of life scores, while sedentary activity and sleep duration were unchanged postoperatively. Dominant reasons for not recovering daily activity included fatigue in 43% and pain in 33% of patients. Despite compliance with an enhanced recovery programme with a median length of hospital stay of 3 days after video-assisted thoracoscopic lobectomy, functional recovery was not achieved within 7 days after hospital discharge. Reduction in postoperative pain and fatigue are important factors to enhance functional recovery.

[Clinical application effects of two longitudes three transverses method in perforator location of thoracodorsal artery perforator flap and deep wound repair]

Objective: To explore the clinical application value of two longitudes three transverses method in the location of the perforator of thoracodorsal artery perforator and deep wound repair. Methods: The retrospectively observational study was conducted. From December 2018 to June 2020, 17 patients with deep wounds who were admitted to the Affiliated Hospital of Zunyi Medical University met the inclusion criteria and were included in this study, including 7 males and 10 females, aged 12 to 72 years. The wound areas of patients after debridement were 7 cm×3 cm to 11 cm×7 cm. Two longitudinal lines were located through the midpoint of the armpit, the posterior superior iliac spine, and the protruding point of the sacroiliac joint, and three transverse lines were located 5, 10, and 15 cm below the midpoint of the armpit between the two longitudinal lines, i.e. two longitudes three transverses method, resulting in two trapezoidal areas. And then the thoracodorsal artery perforators in two trapezoidal areas were explored by the portable Doppler blood flow detector. On this account, a single or lobulated free thoracodorsal artery perforator flap or flap that carrying partial latissimus dorsi muscle, with an area of 7 cm×4 cm to 12 cm×8 cm was designed and harvested to repair the wound. The donor sites were all closed by suturing directly. The number and location of thoracodorsal artery perforators, and the distance from the position where the first perforator (the perforator closest to the axillary apex) exits the muscle to the lateral border of the latissimus dorsi in preoperative localization and intraoperative exploration, the diameter of thoracodorsal artery perforator measured during operation, and the flap types were recorded. The survivals of flaps and appearances of donor sites were followed up. Results: The number and location of thoracodorsal artery perforators located before operation in each patient were consistent with the results of intraoperative exploration. A total of 42 perforators were found in two trapezoidal areas, with 2 or 3 perforators each patient. The perforators were all located in two trapezoid areas, and a stable perforator (the first perforator) was located and detected in the first trapezoidal area. There were averagely 1.47 perforators in the second trapezoidal area. The position where the first perforator exits the muscle was 2.1-3.1 cm away from the lateral border of the latissimus dorsi. The diameters of thoracodorsal artery perforators were 0.4-0.6 mm. In this group, 12 cases were repaired with single thoracodorsal artery perforator flap, 3 cases with lobulated thoracodorsal artery perforator flap, and 2 cases with thoracodorsal artery perforator flap carrying partial latissimus dorsi muscle. The patients were followed up for 6 to 16 months. All the 17 flaps survived with good elasticity, blood circulation, and soft texture. Only linear scar was left in the donor area. Conclusions: The two longitudes three transverses method is helpful to locate the perforator of thoracodorsal artery perforator flap. The method is simple and reliable. The thoracodorsal artery perforator flap designed and harvested based on this method has good clinical effects in repairing deep wound, with minimal donor site damage.

Sodium MRI at 7T for Early Response Evaluation of Intracranial Tumors following Stereotactic Radiotherapy Using the CyberKnife

BACKGROUND AND PURPOSE

Conventionally, early treatment response to stereotactic radiotherapy in intracranial tumors is often determined by structural MR imaging. Tissue sodium concentration is altered by cellular integrity and energy status in cells. In this study, we aimed to investigate the feasibility of sodium MR imaging at 7T for the preliminary evaluation of radiotherapeutic efficacy for intracranial tumors.

MATERIALS AND METHODS

Data were collected from 16 patients (12 men and 4 women, 24-75 years of age) with 22 intracranial tumors who were treated with stereotactic radiation therapy using CyberKnife at our institution between December 1, 2016, and August 15, 2019. Sodium MR imaging was performed at 7T before and 48 hours, 1 week, and 1 month after CyberKnife radiation therapy. Tissue sodium concentration (TSC) was calculated and analyzed based on manually labeled regions of tumors.

RESULTS

Ultra-high-field sodium MR imaging clearly showed the intratumoral signal, which is significantly higher than that of normal tissue (t = 5.250, P <.001)., but the edema zone has some influence. The average TSC ratios of tumor to CSF in the 22 tumors, contralateral normal tissues, edema zones, frontal cortex, and frontal white matter were 0.66 (range, 0.23-1.5), 0.30 (range, 0.15-0.43), 0.58 (range, 0.25-1.21), 0.25 (range, 0.17-0.42), and 0.30 (range, 0.19-0.49), respectively. A total of 12 tumors in 8 patients were scanned at 48 hours, 1 week, and 1 month after treatment. The average TSC at 48 hours after treatment was 0.06 higher than that before treatment and began to decrease at 1 week. The TSC ratios of 10 continued to decline and 2 tumors increased at 1 month, respectively. Tumor volume decreased by 2.4%-99% after 3 months.

CONCLUSIONS

Changes in the TSC can be quantified by sodium MR imaging at 7T and used to detect radiobiologic alterations in intracranial tumors at early time points after CyberKnife radiation therapy.

The potential roles of RNA N6-methyladenosine in atherosclerosis

OBJECTIVE

Atherosclerosis, characterized by endothelial injury, multicellular involvement, chronic inflammation, and lipid deposition, can lead to acute cardiovascular events. N6-methyladenosine (m6A) is the most abundant, prevalent RNA modification in mammalian cells. m6A, a reversible modification, can be catalyzed by m6A methyltransferase complexes (writers), reverted by demethylases (erasers), and recognized by m6A-binding proteins (readers). Emerging evidence suggests that m6A modification plays a significant role in regulating many biological and cellular processes in atherosclerosis. In this review, we highlight the biological function of m6A modification and give a brief perspective on its future applications in atherosclerosis.

MATERIALS AND METHODS

This is a narrative review. The literature search strategy for indexed Scopus articles was performed randomly using PubMed and MEDLINE as the primary sources. No specific term was used.

RESULTS

As the mechanism of the relationship between inflammatory response and atherosclerosis, m6A has become a new focus in the study of clinical treatment strategies for atherosclerosis. METTL14-dependent m6A modification may be a target for atherosclerosis therapy. A variety of m6A regulatory factors promote the progression of atherosclerosis by regulating polarization and inflammation of macrophages. WTAP and METTL14 can affect the phenotypic modulation of VSMCs through m6A modification.

CONCLUSIONS

The existence of m6A in cardiovascular transcripts is necessary to maintain cardiac function, and the level of m6A modification is increased in a variety of atherosclerotic vascular cells, indicating that m6A modification is involved in the pathophysiological process of atherosclerosis. m6A modification plays an important character in atherosclerosis.

Large Culprit Plaque and More Intracranial Plaques Are Associated with Recurrent Stroke: A Case-Control Study Using Vessel Wall Imaging

BACKGROUND AND PURPOSE

Intracranial atherosclerotic plaque features are potential factors associated with recurrent stroke, but previous studies only focused on a single lesion, and few studies investigated them with perfusion impairment. This study aimed to investigate the association among whole-brain plaque features, perfusion deficit, and stroke recurrence.

MATERIALS AND METHODS

Patients with ischemic stroke due to intracranial atherosclerosis were retrospectively collected and categorized into first-time and recurrent-stroke groups. Patients underwent high-resolution vessel wall imaging and DSC-PWI. Intracranial plaque number, culprit plaque features (such as plaque volume/burden, degree of stenosis, enhancement ratio), and perfusion deficit variables were recorded. Logistic regression analyses were performed to determine the independent factors associated with recurrent stroke.

RESULTS

One hundred seventy-five patients (mean age, 59 [SD, 12] years; 115 men) were included. Compared with the first-time stroke group (n = 100), the recurrent-stroke group (n = 75) had a larger culprit volume (P = .006) and showed more intracranial plaques (P < .001) and more enhanced plaques (P = .003). After we adjusted for other factors, culprit plaque volume (OR, 1.16 per 10-mm³ increase; 95% CI, 1.03-1.30; P = .015) and total plaque number (OR, 1.31; 95% CI, 1.13-1.52; P < .001) were independently associated with recurrent stroke. Combining these factors increased the area under the curve to 0.71.

CONCLUSIONS

Large culprit plaque and more intracranial plaques were independently associated with recurrent stroke. Performing whole-brain vessel wall imaging may help identify patients with a higher risk of recurrent stroke.

A 2-year locomotive exploration and scientific investigation of the lunar farside by the Yutu-2 rover

The lunar nearside has been investigated by many uncrewed and crewed missions, but the farside of the Moon remains poorly known. Lunar farside exploration is challenging because maneuvering rovers with efficient locomotion in harsh extraterrestrial environment is necessary to explore geological characteristics of scientific interest. Chang'E-4 mission successfully targeted the Moon's farside and deployed a teleoperated rover (Yutu-2) to explore inside the Von Kármán crater, conveying rich information regarding regolith, craters, and rocks. Here, we report mobile exploration on the lunar farside with Yutu-2 over the initial 2 years. During its journey, Yutu-2 has experienced varying degrees of mild slip and skid, indicating that the terrain is relatively flat at large scales but scattered with local gentle slopes. Cloddy soil sticking on its wheels implies a greater cohesion of the lunar soil than encountered at other lunar landing sites. Further identification results indicate that the regolith resembles dry sand and sandy loam on Earth in bearing properties, demonstrating greater bearing strength than that identified during the Apollo missions. In sharp contrast to the sparsity of rocks along the traverse route, small fresh craters with unilateral moldable ejecta are abundant, and some of them contain high-reflectance materials at the bottom, suggestive of secondary impact events. These findings hint at notable differences in the surface geology between the lunar farside and nearside. Experience gained with Yutu-2 improves the understanding of the farside of the Moon, which, in return, may lead to locomotion with improved efficiency and larger range.

Moiré graphene nanoribbons: nearly perfect absorptions and highly efficient reflections with wide angles

The strong absorption and reflection from atomically thin graphene nanoribbons has been demonstrated over the past decade. However, due to the significant band dispersion of graphene nanoribbons, the angle of incident wave has remained limited to a very narrow range. Obtaining strong absorption and reflection with a wide range of incident angles from atomically thin graphene layers has remained an unsolvable problem. Here, we construct a tunable moiré superlattice composed of a pair of graphene nanoribbon arrays to achieve this goal. By designing the interlayer coupling between two graphene nanoribbon arrays with mismatched periods, the moiré flat bands and the localization of their eigen-fields was realized. Based on the moiré flat bands of graphene nanoribbons, highly efficient reflection and nearly perfect absorption was achieved with a wide range of incident angles. Even more interesting, is how these novel phenomena can be tuned through the adjustment of the graphene's Fermi energy, either electrostatically or chemically. Our designed moiré graphene nanoribbons suggest a promising platform to engineer moiré physics with tunable behaviors, and may have potential applications in the field of wide-angle absorbers and reflectors in the mid-infrared region.