Extracellular volume-based scoring system for tracking tumor progression in pancreatic cancer patients receiving intraoperative radiotherapy.

OBJECTIVES: To investigate the value of extracellular volume (ECV) derived from portal-venous phase (PVP) in predicting prognosis in locally advanced pancreatic cancer (LAPC) patients receiving intraoperative radiotherapy (IORT) with initial stable disease (SD) and to construct a risk-scoring system based on ECV and clinical-radiological features. MATERIALS AND METHODS: One hundred and three patients with LAPC who received IORT demonstrating SD were enrolled and underwent multiphasic contrast-enhanced CT (CECT) before and after IORT. ECV maps were generated from unenhanced and PVP CT images. Clinical and CT imaging features were analyzed. The independent predictors of progression-free survival (PFS) determined by multivariate Cox regression model were used to construct the risk-scoring system. Time-dependent receiver operating characteristic (ROC) curve analysis and the Kaplan-Meier method were used to evaluate the predictive performance of the scoring system. RESULTS: Multivariable analysis revealed that ECV, rim-enhancement, peripancreatic fat infiltration, and carbohydrate antigen 19-9 (CA19-9) response were significant predictors of PFS (all p < 0.05). Time-dependent ROC of the risk-scoring system showed a satisfactory predictive performance for disease progression with area under the curve (AUC) all above 0.70. High-risk patients (risk score ≥ 2) progress significantly faster than low-risk patients (risk score < 2) (p < 0.001). CONCLUSION: ECV derived from PVP of conventional CECT was an independent predictor for progression in LAPC patients assessed as SD after IORT. The scoring system integrating ECV, radiological features, and CA19-9 response can be used as a practical tool for stratifying prognosis in these patients, assisting clinicians in developing an appropriate treatment approach. CRITICAL RELEVANCE STATEMENT: The scoring system integrating ECV fraction, radiological features, and CA19-9 response can track tumor progression in patients with LAPC receiving IORT, aiding clinicians in choosing individual treatment strategies and improving their prognosis. KEY POINTS: Predicting the progression of LAPC in patients receiving IORT is important. Our ECV-based scoring system can risk stratifying patients with initial SD. Appropriate prognostication can assist clinicians in developing appropriate treatment approaches.

Exploring the biological basis of CT imaging features in pancreatic neuroendocrine tumors: a two-center study.

Objective.Medical imaging offered a non-invasive window to visualize tumors, with radiomics transforming these images into quantitative data for tumor phenotyping. However, the intricate web linking imaging features, clinical endpoints, and tumor biology was mostly uncharted. This study aimed to unravel the connections between CT imaging features and clinical characteristics, including tumor histopathological grading, clinical stage, and endocrine symptoms, alongside immunohistochemical markers of tumor cell growth, such as the Ki-67 index and nuclear mitosis rate.Approach.We conducted a retrospective analysis of data from 137 patients with pancreatic neuroendocrine tumors who had undergone contrast-enhanced CT scans across two institutions. Our study focused on three clinical factors: pathological grade, clinical stage, and endocrine symptom status, in addition to two immunohistochemical markers: the Ki-67 index and the rate of nuclear mitosis. We computed both predefined (2D and 3D) and learning-based features (via sparse autoencoder, or SAE) from the scans. To unearth the relationships between imaging features, clinical factors, and immunohistochemical markers, we employed the Spearman rank correlation along with the Benjamini-Hochberg method. Furthermore, we developed and validated radiomics signatures to foresee these clinical factors.Main results.The 3D imaging features showed the strongest relationships with clinical factors and immunohistochemical markers. For the association with pathological grade, the mean absolute value of the correlation coefficient (CC) of 2D, SAE, and 3D features was 0.3318 ± 0.1196, 0.2149 ± 0.0361, and 0.4189 ± 0.0882, respectively. While for the association with Ki-67 index and rate of nuclear mitosis, the 3D features also showed higher correlations, with CC as 0.4053 ± 0.0786 and 0.4061 ± 0.0806. In addition, the 3D feature-based signatures showed optimal performance in clinical factor prediction.Significance.We found relationships between imaging features, clinical factors, and immunohistochemical markers. The 3D features showed higher relationships with clinical factors and immunohistochemical markers.

PNMC: Four-dimensional conebeam CT reconstruction combining prior network and motion compensation.

Four-dimensional conebeam computed tomography (4D CBCT) is an efficient technique to overcome motion artifacts caused by organ motion during breathing. 4D CBCT reconstruction in a single scan usually divides projections into different groups of sparsely sampled data based on the respiratory phases. The reconstructed images within each group present poor image quality due to the limited number of projections. To improve the image quality of 4D CBCT in a single scan, we propose a novel reconstruction scheme that combines prior knowledge with motion compensation. We apply the reconstructed images of the full projections within a single routine as prior knowledge, providing structural information for the network to enhance the restoration structure. The prior network (PN-Net) is proposed to extract features of prior knowledge and fuse them with the sparsely sampled data using an attention mechanism. The prior knowledge guides the reconstruction process to restore the approximate organ structure and alleviates severe streaking artifacts. The deformation vector field (DVF) extracted using deformable image registration among different phases is then applied in the motion-compensated ordered-subset simultaneous algebraic reconstruction algorithm to generate 4D CBCT images. Proposed method has been evaluated using simulated and clinical datasets and has shown promising results by comparative experiment. Compared with previous methods, our approach exhibits significant improvements across various evaluation metrics.

UBES: Unified scatter correction using ultrafast Boltzmann equation solver for conebeam CT.

A semi-analytical solution to the unified Boltzmann equation is constructed to exactly describe the scatter distribution on a flat-panel detector for high-quality conebeam CT (CBCT) imaging. The solver consists of three parts, including the phase space distribution estimator, the effective source constructor and the detector signal extractor. Instead of the tedious Monte Carlo solution, the derived Boltzmann equation solver achieves ultrafast computational capability for scatter signal estimation by combining direct analytical derivation and time-efficient one-dimensional numerical integration over the trajectory along each momentum of the photon phase space distribution. The execution of scatter estimation using the proposed ultrafast Boltzmann equation solver (UBES) for a single projection is finalized in around 0.4 seconds. We compare the performance of the proposed method with the state-of-the-art schemes, including a time-expensive Monte Carlo (MC) method and a conventional kernel-based algorithm using the same dataset, which is acquired from the CBCT scans of a head phantom and an abdominal patient. The evaluation results demonstrate that the proposed UBES method achieves comparable correction accuracy compared with the MC method, while exhibits significant improvements in image quality over learning and kernel-based methods. With the advantages of MC equivalent quality and superfast computational efficiency, the UBES method has the potential to become a standard solution to scatter correction in high-quality CBCT reconstruction.

Enhanced Recovery After Surgery (ERAS) Program for Anterior Cervical Discectomy and Fusion (ACDF) in Patients Over 60 Years Old.

Background: Enhanced recovery after surgery (ERAS) is currently widely used in many surgical specialties, but there is still a lack of concern about the cervical ERAS program for old patients (>60 years old). We aimed to determine whether our ERAS program significantly improved satisfaction and outcomes in old patients (>60 years old) with anterior cervical discectomy and fusion (ACDF). Methods: This is a retrospective cohort study. The study enrolled patients if they were over the age of 60 years old underwent ACDF from July 2019 and June 2021 (ERAS group) and from January 2018 and June 2019 (non-ERAS group). Data including demographic, comorbidity, and surgical information were collected. We also evaluated ERAS process compliance, primary outcome, surgical complication, and length of stay (LOS). Results: There were 135 patients in the ERAS group, and 122 patients in the non-ERAS group were included. A comparison of the demographic data revealed that there were no statistically significant intergroup differences observed between the group. Overall, ERAS pathway compliance was 91.9%. There were no significant differences in the fusion levels, operative time, intraoperative blood loss, postoperative VAS score, and complications between the ERAS and non-ERAS groups. In addition, there was no significant difference in readmission and mortality at 30-day follow-up between the two groups. However, we observed a statistically significant decrease in the LOS in the ERAS group (8.68±2.34 of ERAS group versus 10.43±4.05 in non-ERAS group, p=0.013). Conclusion: This report describes the first ERAS protocol used in old patients with ACDF. Our ERAS program is safe and associated with incremental benefits with respect to LOS in old patients with ACDF.

Combined CT and serum CA19-9 for stratifying risk for progression in patients with locally advanced pancreatic cancer receiving intraoperative radiotherapy.

Background and purpose: The aim of this study was to evaluate the significance of baseline computed tomography (CT) imaging features and carbohydrate antigen 19-9 (CA19-9) in predicting prognosis of locally advanced pancreatic cancer (LAPC) receiving intraoperative radiotherapy (IORT) and to establish a progression risk nomogram that helps to identify the potential beneficiary of IORT. Methods: A total of 88 LAPC patients with IORT as their initial treatment were enrolled retrospectively. Clinical data and CT imaging features were analyzed. Cox regression analyses were performed to identify the independent risk factors for progression-free survival (PFS) and to establish a nomogram. A risk-score was calculated by the coefficients of the regression model to stratify the risk of progression. Results: Multivariate analyses revealed that relative enhanced value in portal-venous phase (REV-PVP), peripancreatic fat infiltration, necrosis, and CA19-9 were significantly associated with PFS (all p < 0.05). The nomogram was constructed according to the above variables and showed a good performance in predicting the risk of progression with a concordance index (C-index) of 0.779. Our nomogram stratified patients with LAPC into low- and high-risk groups with distinct differences in progression after IORT (p < 0.001). Conclusion: The integrated nomogram would help clinicians to identify appropriate patients who might benefit from IORT before treatment and to adapt an individualized treatment strategy.

Retrospective Data Analysis for Enhanced Recovery After Surgery (ERAS) Protocol for Elderly Patients with Long-Level Lumbar Fusion.

BACKGROUND: Enhanced recovery after surgery (ERAS) for spinal surgery is new; specifically, an ERAS program for elderly patients is lacking. Geriatric patients have special characteristics that result in further harm by surgical stress. ERAS interventions are designed to improve recovery after surgery and can result in substantial benefits in clinical outcomes and cost-effectiveness. We aimed to determine whether ERAS significantly improved satisfaction and outcomes in elderly patients with long-level lumbar fusion. METHODS: Patients >70 years old with lumbar disc herniation or lumbar spinal stenosis who underwent lumbar fusion of ≥3 levels from July 2019 to June 2021 (ERAS group) and from January 2018 to June 2019 (non-ERAS group) were enrolled. Demographic, comorbidity, and surgical data were collected from electronic medical records. ERAS interventions were categorized as preoperative, intraoperative, and postoperative. We also evaluated primary outcome, surgical complications, and length of stay (LOS). RESULTS: The study included 154 patients, 72 in the ERAS group and 82 case-matched patients in the non-ERAS group. Overall, ERAS pathway compliance was 91%. There were no significant differences in readmission and mortality rates at 30-day follow-up between the ERAS and non-ERAS groups. Statistically significant decreases were observed in the ERAS group in complications (6 in ERAS group vs. 19 in non-ERAS group, P = 0.013) and LOS (17.74 ± 5.56 days in ERAS group vs. 22.13 ± 12.21 days in non-ERAS group, P = 0.041). Multivariable linear regression showed that implementation of ERAS (P = 0.002) was correlated with LOS. Multivariable logistic regression showed that implementation of ERAS (P = 0.004) was correlated with complications. CONCLUSIONS: The ERAS protocol used in elderly patients after long-level lumbar fusion surgery was safe and associated with incremental benefits regarding complications and LOS.

The Mechanism of Downregulated Interstitial Fluid Drainage Following Neuronal Excitation.

The drainage of brain interstitial fluid (ISF) has been observed to slow down following neuronal excitation, although the mechanism underlying this phenomenon is yet to be elucidated. In searching for the changes in the brain extracellular space (ECS) induced by electrical pain stimuli in the rat thalamus, significantly decreased effective diffusion coefficient (DECS) and volume fraction (α) of the brain ECS were shown, accompanied by the slowdown of ISF drainage. The morphological basis for structural changes in the brain ECS was local spatial deformation of astrocyte foot processes following neuronal excitation. We further studied aquaporin-4 gene (APQ4) knockout rats in which the changes of the brain ECS structure were reversed and found that the slowed DECS and ISF drainage persisted, confirming that the down-regulation of ISF drainage following neuronal excitation was mainly attributable to the release of neurotransmitters rather than to structural changes of the brain ECS. Meanwhile, the dynamic changes in the DECS were synchronized with the release and elimination processes of neurotransmitters following neuronal excitation. In conclusion, the downregulation of ISF drainage following neuronal excitation was found to be caused by the restricted diffusion in the brain ECS, and DECS mapping may be used to track the neuronal activity in the deep brain.

Enhanced recovery after surgery (ERAS) program for elderly patients with short-level lumbar fusion.

BACKGROUND: Degenerative disorders of the lumbar spine decrease the mobility and quality of life of elderly patients. Lumbar fusion surgery is the primary method of treating degenerative lumbar spine disorders; however, the surgical stress response associated with major surgery has been linked to pathophysiological changes in the elderly, resulting in undesirable postoperative morbidity, complications, pain, fatigue, and extended convalescence. In the present study, we aimed to determine whether enhanced recovery after surgery significantly improved satisfaction and outcomes in elderly patients (> 65 years old) with short-level lumbar fusion. METHODS: The study enrolled lumbar disc herniation or lumbar spinal stenosis patients if they were over the age of 65 years old underwent lumbar fusion at one or two levels. Data including demographic, comorbidity, and surgical information were collected from electronic medical records. Enhanced recovery after surgery interventions was categorized as preoperative, intraoperative, and postoperative. We also evaluated primary outcome, surgical complication, length of stay, postoperative pain scores, and 30-day readmission rates. RESULTS: A total of 192 patients were included, 96 in the enhanced recovery after surgery group and 96 case-matched patients in the non- enhanced recovery after surgery group. There were no statistically significant intergroup differences in regards to demographics, comorbidities, American Society of Anaesthesiologists grade, or the number of fusion levels. There were also no differences between mean surgery time of intraoperative blood loss between the enhanced recovery after surgery and non- enhanced recovery after surgery groups. In addition, the mean preoperative Japanese Orthopaedic Association score, visual analog score for the back and legs, and Oswestry Disability Index score were not significantly different between the two groups. Overall, enhanced recovery after surgery pathway compliance was 92.1%. There were no significant differences in the number of complications or the mortality rates between the enhanced recovery after surgery and non-enhanced recovery after surgery groups. Furthermore, the mean postoperative Japanese Orthopaedic Association score, Visual analog score for the back and legs, Oswestry Disability Index score, and readmission rates score revealed no significant differences between the groups at 30-day follow-up point. However, we observed a statistically significant decrease in length of stay in the enhanced recovery after surgery group (12.30 ± 3.03 of enhanced recovery after surgery group versus 15.50 ± 1.88 in non- enhanced recovery after surgery group, p = 0). Multivariable linear regression showed that comorbidities (p = 0.023) and implementation of enhanced recovery after surgery program (p = 0.002) were correlated with prolonged length of stay. Multivariable logistic regression showed that no characteristics were associated with complications. CONCLUSIONS: This report describes the first enhanced recovery after surgery protocol used in elderly patients after short-level lumbar fusion surgery. Our enhanced recovery after surgery program is safe and could help decrease length of stay in elderly patients with short-level lumbar fusion.

The COL6A1 rs201153092 single nucleotide polymorphism, associates with thoracic ossification of the posterior longitudinal ligament.

Thoracic ossification of the posterior longitudinal ligament (T­OPLL) is one of the most common factors that causes thoracic spinal stenosis, resulting in intractable myelopathy and radiculopathy. Our previous study reported that the rs201153092 polymorphism present in the collagen 6A1 (COL6A1) gene was a potentially pathogenic locus for the development of T­OPLL. The present study aimed to determine whether the rs201153092 mutation causes abnormal expression of COL6A1 in Han Chinese patients with T­OPLL, and to examine the effects of this mutation on osteogenesis by establishing a model of osteogenic differentiation. COL6A1 gene mutant and wild­type mouse 3T3­E1 embryonic osteoblast models were constructed to induce the differentiation of these cells into osteoblasts. The potential of the mutation site to induce abnormal expression of the COL6A1 gene and osteogenic markers was assessed via reverse transcription­quantitative PCR and western blot analyses. The results demonstrated that the rs201153092A mutation site resulted in significantly increased COL6A1 gene expression levels in the OPLL tissues obtained following clinical surgery. This mutation was shown to play an important role in the development of T­OPLL by regulating the overexpression of the COL6A1 gene and significantly increasing the expression levels of osteogenic markers. The findings of the present study suggested that the rs201153092A mutant variant could increase the expression levels of COL6A1 and consequently play a role in the pathogenesis of T­OPLL.

A new single nucleotide polymorphism affects the predisposition to thoracic ossification of the posterior longitudinal ligament.

BACKGROUND: Thoracic ossification of the posterior longitudinal ligament (T-OPLL) is one of the common factors that cause thoracic spinal stenosis, which results in intractable myelopathy and radiculopathy. Our previous study first reported rs201153092A site mutation in the collagen 6A1 (COL6A1) gene as a potentially pathogenic locus for T-OPLL. We aimed to determine whether the rs201153092A site mutation causes abnormal expression of the COL6A1 in Han Chinese patients with T-OPLL and whether this locus is also associated with cervical-OPLL. METHODS: Peripheral blood was collected from a total of 60 patients with T-OPLL disease (30 patients carrying the rs201153092A site mutation in COL6A1 and 30 wild-type patients) and 400 northern Chinese individuals (200 cervical-OPLL patients and 200 control subjects) using the Sequenom system. The expression of COL6A1 was analyzed by enzyme-linked immunosorbent assay, reverse transcription-quantitative polymerase chain reaction, and Western blotting. RESULTS: rs201153092A mutation resulted in markedly increased COL6A1 gene expression levels in peripheral blood samples. The allele frequency and genotype frequency results showed that this locus is no difference between cervical-OPLL patients and controls. CONCLUSIONS: The rs201153092A site mutation of COL6A1 can significantly increase the expression of COL6A1. The COL6A1 gene rs201153092A site polymorphism is a potential pathogenic mutation in T-OPLL disease, which may be only associated with the occurrence of T-OPLL.

The Drainage of Interstitial Fluid in the Deep Brain is Controlled by the Integrity of Myelination.

In searching for the drainage route of the interstitial fluid (ISF) in the deep brain, we discovered a regionalized ISF drainage system as well as a new function of myelin in regulating the drainage. The traced ISF from the caudate nucleus drained to the ipsilateral cortex along myelin fiber tracts, while in the opposite direction, its movement to the adjacent thalamus was completely impeded by a barrier structure, which was identified as the converged, compact myelin fascicle. The regulating and the barrier effects of myelin were unchanged in AQP4-knockout rats but were impaired as the integrity of boundary structure of drainage system was destroyed in a demyelinated rat model. We thus proposed that the brain homeostasis was maintained within each ISF drainage division locally, rather than across the brain as a whole. A new brain division system and a new pathogenic mechanism of demyelination are therefore proposed.

IL17RC affects the predisposition to thoracic ossification of the posterior longitudinal ligament.

BACKGROUND: Thoracic ossification of the posterior longitudinal ligament (T-OPLL) can cause thoracic spinal stenosis, which results in intractable myelopathy and radiculopathy. The etiology of T-OPLL is unknown and the condition is difficult to treat surgically. Whole-genome sequencing identified a genetic variant at rs199772854 of the interleukin 17 receptor C (IL17RC) gene as a potentially pathogenic locus associated with T-OPLL. We aimed to determine whether the rs199772854A site mutation causes abnormal expression of the IL17RC in Han Chinese patients with T-OPLL and predict the possible pathogenic mechanisms of T-OPLL. Analyses were performed to determine whether IL17RC is involved in the pathogenicity of T-OPLL. METHODS: Peripheral blood and OPLL tissue were collected from a total of 72 patients with T-OPLL disease (36 patients carrying the rs199772854A site mutation in IL17RC and 36 wild-type patients). The expression of IL17RC was analyzed by enzyme-linked immunosorbent assay, reverse transcription-quantitative polymerase chain reaction, immunohistochemistry, and Western blotting. RESULTS: rs199772854A mutation resulted in markedly increased IL17RC gene expression levels in peripheral blood samples and the OPLL tissue obtained following clinical surgery (P < 0.05). CONCLUSIONS: The results suggest that the rs199772854A site mutation of IL17RC can significantly increase the expression of IL17RC. The IL17RC gene rs199772854A site polymorphism is a potential pathogenic mutation in T-OPLL disease, which may be associated with the occurrence of T-OPLL.

Potential role of the IL17RC gene in the thoracic ossification of the posterior longitudinal ligament.

The thoracic ossification of the posterior longitudinal ligament (T­OPLL) can cause thoracic spinal stenosis, which results in intractable myelopathy and radiculopathy. Our previous whole­genome sequencing study first reported rs199772854 in the interleukin 17 receptor C (IL17RC) gene as a potentially pathogenic loci for T­OPLL. The aim of the present study was to examine the effects of the IL17RC gene rs199772854A site mutation on osteogenesis by establishing a model of osteogenic differentiation. IL17RC gene mutation site and wild­type site mouse embryonic osteoblast (3T3­E1) models were constructed in order to induce the differentiation of the cells into osteoblasts. Whether the mutation site causes the abnormal expression of the IL17RC gene and osteogenic markers was analyzed by reverse transcription­quantitative polymerase chain reaction (RT­qPCR) and western blot analysis. The IL17RC gene rs199772854A site mutation was demonstrated to play a biological role through the overexpression of its own gene, and also to significantly increase the expression levels of osteogenic markers. Furthermore, the mutation upregulated the expression of the key proteins, tumor necrosis factor receptor (TNFR)­associated factor 6 (TRAF6) and nuclear factor (NF)­κB, in the interleukin (IL)­17 signaling axis. On the whole, the findings of this study suggest that the IL17RC gene rs199772854A loci mutation propels mouse embryonic osteoblasts towards osteogenic differentiation and may play an important role in the pathogenesis of T­OPLL. The IL17RC gene may promote osteogenesis through the IL­17 signaling pathway and may thus be involved in the process of ectopic osteogenesis in T­OPLL.

The Protective Roles of Urinary Trypsin Inhibitor in Brain Injury Following Fat Embolism Syndrome in a Rat Model.

Fat embolism syndrome (FES) is a common complication following long bone fracture; fat droplets are released into the blood circulation and form embolisms, mainly in lung and brain. However, the potential mechanisms involved remain to be clarified. In this study, the mechanism of brain injury following FES and the protective effects of urinary trypsin inhibitor (UTI)-a serine protease inhibitor-were investigated. Sixty male Sprague-Dawley rats were divided randomly into sham, FES and FES+UTI treatment groups. The FES model was established using tail vein injection of glycerol trioleate, and UTI was administered by intraperitoneal injection immediately following FES. Brain/lung water content evaluation, Evans blue content and magnetic resonance imaging examination were used to assess the effects of UTI. Furthermore, immunohistochemistry and western blot were also applied to explore the protective mechanism of UTI following FES. The results of oil red O staining indicated that the FES model was successfully established. UTI could significantly attenuate blood-brain-barrier (BBB) disruption, as seen through brain edema evaluation and Evans blue content examination. Immunofluorescence staining results indicated that the TLR4-JNK pathway was involved in brain injury after FES; this effect could be quenched by UTI treatment. Furthermore, UTI could decrease the levels of downstream target proteins of the TLR4-JNK pathway, phosphorylated-NF- κB (p65) and p53 in brain. Our results showed that UTI could alleviate BBB injury after FES through blocking activity of the TLR4-JNK pathway.

The Effect of Aquaporin-4 Knockout on Interstitial Fluid Flow and the Structure of the Extracellular Space in the Deep Brain.

It has been reported that aquaporin-4 (AQP4) deficiency impairs transportation between the cerebrospinal fluid and interstitial fluid (ISF) as well as the clearance of interstitial solutes in the superficial brain. However, the effect of AQP4 on ISF flow in the deep brain remains unclear. This study compared the brain ISF flow in the caudate nucleus and thalamus of normal rats (NO) and AQP4 knockout rats (KO) using tracer-based magnetic resonance imaging. The rate of brain ISF flow slowed to different degrees in the two regions of KO rats' brains. Compared with NO rats, the half-life of ISF in the thalamus of KO rats was significantly prolonged, with a corresponding decrease in the clearance coefficient. The tortuosity of the brain extracellular space (ECS) was unchanged in the thalamus of KO rats. In the caudate nucleus of KO rats, the volume fraction of the ECS and the diffusion coefficient were increased, with significantly decreased tortuosity; no significant changes in brain ISF flow were demonstrated. Combined with a change in the expression of glial fibrillary acidic protein and AQP4 in two brain regions, we found that the effect of AQP4 knockout on ISF flow and ECS structure in these two regions differed. This difference may be related to the distribution of astrocytes and the extent of AQP4 decline. This study provides evidence for the involvement of AQP4 in ISF transportation in the deep brain and provides a basis for the establishment of a pharmacokinetic model of the brain's interstitial pathway.

Association of IL17RC and COL6A1 genetic polymorphisms with susceptibility to ossification of the thoracic posterior longitudinal ligament in Chinese patients.

BACKGROUND: In our previous whole-genome sequencing study of 30 unrelated northern Chinese Han patients, we identified six single nucleotide polymorphisms (SNPs) in the interleukin 17 receptor C (IL17RC) and collagen type VI α1 chain (COL6A1) genes that were potentially associated with thoracic ossification of the posterior longitudinal ligament (T-OPLL). To determine whether these six SNPs are associated with susceptibility to T-OPLL in the northern Chinese Han population, we performed a case-control association study to confirm specific susceptible loci in the expanded samples. METHODS: The six SNPs in the IL17RC and COL6A1 genes were analyzed in 200 northern Chinese individuals (100 patients and 100 control subjects) using the Sequenom system. RESULTS: The genotype distributions and allele frequencies of each SNP in the control and patient groups were compared. rs201153092, rs13051496, rs199772854, rs76999397, and rs189013166 showed potential pathogenic loci for T-OPLL in the northern Chinese Han population, whereas rs151158105 did not. At the genotype level, the differences in the genotype frequencies of rs201153092, rs13051496, rs199772854, rs76999397, and rs189013166 between T-OPLL cases and controls reached statistical significance. CONCLUSIONS: To the best of our knowledge, this is the first association study of susceptibility genes in Han Chinese patients with T-OPLL. The results revealed five SNPs in the IL17RC and COL6A1 genes that represented potentially pathogenic mutations in patients with T-OPLL.

Identification of susceptibility loci for thoracic ossification of the posterior longitudinal ligament by whole-genome sequencing.

Ossification of the posterior longitudinal ligament (OPLL) is a myelopathy commonly observed in the cervical spine. By contrast, thoracic OPLL (T­OPLL) is rare but more severe. Previous studies have identified several polymorphisms in osteogenic genes that are associated with the occurrence and development of cervical OPLL. However, few genetic studies have evaluated T­OPLL. The present study aimed to identify the genetic factors for OPLL by performing whole­genome sequencing (WGS) in 30 unrelated northern Chinese Han patients with T­OPLL. Using bioinformatics analyses and damaging­variant prediction algorithms, two deleterious variants [c.1534G>A(p.Gly512Ser)/collagen, type VI, α1 (COL6A1)] and [c.2275C>A(p.Leu759Ile)/inteleukin-17 receptor C (IL17RC)] were identified in seven unrelated patients. These two mutations resulted in markedly increased gene expression levels in peripheral blood samples. To the best of our knowledge, this is the first report to describe the use of WGS analysis of T­OPLL in the northern Chinese Han population. The results revealed two novel potentially pathogenic mutations in patients with T­OPLL.

[Effects of Soil Microbial Diversity on the Phosphate Fraction in the Rhizosphere of Phragmites communis in the Yeyahu Wetland in Beijing, China].

In this research, microorganisms in rhizosphere/non-rhizosphere soils of Phragmites communis in the Yeyahu Wetland were studied. A sequential extraction procedure was used to analyze the phosphorus (P) forms in the rhizosphere/non-rhizosphere soil with a variety of plant growth conditions (April, July, October). The soil bacteria community structure and the diversity was measured using the high-throughput of 16S rRNA amplicons. Furthermore, the complete crystallographic analysis (CCA) method was used to analyze the relationship between phosphate solubilizing microorganisms and P transformation in the soil samples. The results showed that the rank order of inorganic P (IP) fractions in the soil was generally as follows:Ca-bound P (Ca-P) > Occluded P (Oc-P) > Fe-bound P (Fe-P) > Exchangeable P (Ex-P) > Al-bound P (Al-P). The IP content was most affected by the growth of Phragmites communis. The minimum content of IP appeared in the vigorous growth period and the total IP content in the rhizosphere soil was generally lower than in the non-rhizosphere soil. The rank order of organic P (OP) fractions were highly resistant OP (HR-OP) > moderately resistant OP (MR-OP) > moderately labile OP (ML-OP) > labile OP (L-OP), and all the components of OP first decreased and then increased with the growth of plant. The major phylogenic groups in rhizosphere/non-rhizosphere soil of Phragmites communis, included Proteobacteria, Acidobacteria, Chloroflexi, and Actinobacteria among which, Proteobacteria was the majority group in the community composition. Furthermore, the rhizosphere/non-rhizosphere microbial community structure was significantly affected by seasonal changes and existing differences between the rhizosphere and non-rhizosphere soils. In addition, the main functional groups of the modal transformation of P bacteria genera were Bacillus, Enterobacter, Pseudomonas, Burkholderia, Acinetobacter, which can make use of most OP and IP, playing an important role in the transformation of P in wetland soils.