Dorsal Column Myelopathy Following Intrathecal Chemotherapy for Leukemia

PURPOSE/OBJECTIVE(S)

Intrathecal (IT) methotrexate (Mtx) and/or cytarabine (AraC) improve CNS disease control in patients (pts) with hematologic malignancies. There are increasing number of case reports of irreversible, primarily dorsal column myelopathy in pts treated with IT chemotherapy. By describing the largest case series of myelopathy following IT chemotherapy, we aim to raise awareness about this devastating albeit rare complication.

MATERIALS/METHODS

We retrospectively reviewed 25 pts with leukemia who developed paraplegia following IT chemotherapy between 2/2006 and 9/2021. Clinical/treatment characteristics, response, and toxicity were extracted from the medical records.

RESULTS

Seventeen pts (68%) were male, 16 had B-cell ALL (64%), 4 had AML (16%), 2 had CML (8%), 2 had T-ALL (8%), and 1 had BPDCN (4%). The median age at diagnosis was 38 years (IQR 30-59). All pts required systemic salvage treatment after induction chemotherapy with a median number of 3 regimens received (IQR 2-5.5). In total, the median number of IT treatments was 19 per pt (IQR 14-27). Most pts (84%, n = 21) received single agent IT Mtx alternating with single agent AraC. Fifteen pts (60%) received triple IT therapy with a median of 3 treatments (IQR 0-8). Prior to the onset of myelopathy, 10 pts (40%) received allogeneic SCT and 9 pts (36%) were treated with radiation therapy. Median follow-up from diagnosis was 1.9 yrs (IQR 1.3-4.1). Myelopathy was progressive and irreversible in all pts (n = 25); 84% (n = 21) experienced sensory loss, and all pts had extremity weakness. Symptoms were ascending in 11 pts (44%) and descending in 4 pts (16%). Irreversible bowel/bladder incontinence developed in 12 pts (48%). CSF analysis at the time of symptom onset was negative for leukemia cells in most pts (n = 21, 84%) and showed malignant cells in 4 pts (16%). CSF studies showed elevated protein in 21 pts (84%). Myelin basic protein was elevated in all 13 assessed pts. On T2 weighted spinal MRI, all pts had enhancement of the dorsal columns, including 80% of pts with this dorsal column abnormality reported at the time of the study and 20% of pts (n = 5) with the dorsal enhancement noted retrospectively. Due to concern for occult disease, 20 pts (80%) received additional CNS-directed therapy after symptom onset. Twenty-two pts (88%) died at last follow-up. The time between neurological symptom onset and death was a median 3.5 months (IQR 2.6 and 5). Three pts (12%) are alive with paraplegia at a median of 4.4 years from symptom onset.

CONCLUSION

Dorsal column myelopathy is a rare but devastating condition that can occur after IT chemotherapy in heavily pre-treated leukemia pts. T2 weighted spinal MRI can be helpful in the evaluation of pts that present with unexplained weakness and sensory changes. We recommend delaying additional CNS-directed therapy until work-up to rule out alternative etiologies is complete. Future strategies are desperately needed to address this irreversible treatment complication.

Three-dimensional co-culture model employing silica nonwoven fabrics to enhance cell-to-cell communication of paracrine signaling between hepatocytes and fibroblasts

The realization that soluble factors secreted by heterotypic cells play an importanta role in paracrine signaling, which facilitates intercellular communication, enabled the development of physiologically relevant co-culture models for drug screening and the engineering of tissues, such as hepatic tissues. The most crucial issues confronting the use of conventional membrane inserts in segregated co-culture models that are used to study paracrine signaling between heterotypic cells have been identified as long-term viability and retention of cell-specific functions, especially when isolated primary cells are used. Herein, we present an in vitro segregated co-culture model consisting of a well plate incubated with rat primary hepatocytes and normal human dermal fibroblasts which were segregated using a membrane insert with silica nonwoven fabric (SNF) on it. SNF, which mimics a physiological environment much more effectively than a two-dimensional (2D) one, promotes cell differentiation and resultant paracrine signaling in a manner that is not possible in a conventional 2D culture, owing to high mechanical strength generated by its inorganic materials and interconnected network structure. In segregated co-cultures, SNF clearly enhanced the functions of hepatocytes and fibroblasts, thereby showing its potential as a measure of paracrine signaling. These results may advance the understanding of the role played by paracrine signaling in cell-to-cell communication and provide novel insights into the applications of drug metabolism, tissue repair, and regeneration.

Development of hydroxyapatite-coated nonwovens for efficient isolation of somatic stem cells from adipose tissues

Adipose-derived stem cells (ASCs) are an attractive cell source for cell therapy. Despite the increasing number of clinical applications, the methodology for ASC isolation is not optimized for every individual. In this study, we developed an effective material to stabilize explant cultures from small-fragment adipose tissues.

Methods

Polypropylene/polyethylene nonwoven sheets were coated with hydroxyapatite (HA) particles. Adipose fragments were then placed on these sheets, and their ability to trap tissue was monitored during explant culture. The yield and properties of the cells were compared to those of cells isolated by conventional collagenase digestion.

Results

Hydroxyapatite-coated nonwovens immediately trapped adipose fragments when placed on the sheets. The adhesion was stable even in culture media, leading to cell migration and proliferation from the tissue along with the nonwoven fibers. A higher fiber density further enhanced cell growth. Although cells on nonwoven explants could not be fully collected with cell dissociation enzymes, the cell yield was significantly higher than that of conventional monolayer culture without impacting stem cell properties.

Conclusions

Hydroxyapatite-coated nonwovens are useful for the effective primary explant culture of connective tissues without enzymatic cell dissociation.

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Hydroxyapatite-coated nonwovens enable explant culture of adipose tissue.

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ASCs migrated and proliferated from the tissue explants along the fibers in nonwovens.

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Nonwoven explants had significantly higher cell yield than conventional culture.

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Nonwoven culture did not impact stem cell properties of ASCs.

Nanoscale defect evaluation framework combining real-time transmission electron microscopy and integrated machine learning-particle filter estimation

Observation of dynamic processes by transmission electron microscopy (TEM) is an attractive technique to experimentally analyze materials’ nanoscale phenomena and understand the microstructure-properties relationships in nanoscale. Even if spatial and temporal resolutions of real-time TEM increase significantly, it is still difficult to say that the researchers quantitatively evaluate the dynamic behavior of defects. Images in TEM video are a two-dimensional projection of three-dimensional space phenomena, thus missing information must be existed that makes image’s uniquely accurate interpretation challenging. Therefore, even though they are still a clustering high-dimensional data and can be compressed to two-dimensional, conventional statistical methods for analyzing images may not be powerful enough to track nanoscale behavior by removing various artifacts associated with experiment; and automated and unbiased processing tools for such big-data are becoming mission-critical to discover knowledge about unforeseen behavior. We have developed a method to quantitative image analysis framework to resolve these problems, in which machine learning and particle filter estimation are uniquely combined. The quantitative and automated measurement of the dislocation velocity in an Fe-31Mn-3Al-3Si autunitic steel subjected to the tensile deformation was performed to validate the framework, and an intermittent motion of the dislocations was quantitatively analyzed. The framework is successfully classifying, identifying and tracking nanoscale objects; these are not able to be accurately implemented by the conventional mean-path based analysis.

Intraventricular pressure gradient: a promising tool to predict the post-infarction chronic congestive heart failure in rats

Funding Acknowledgements

Type of funding sources: None.

Background/Introduction: Congestive heart failure (CHF), the main reason for morbidity and mortality, is considered a serious consequence of myocardial infarction (MI). The use of left ventricular end-diastolic pressure (LVEDP) as a chief indicator of CHF becomes limited because of the possible impairment of cardiac function and induced aortic valve damage during its recording. Echocardiography is the gold standard approach to diagnose structural myocardial dysfunction. However, its ability to predict chronic CHF following MI is still limited. Recently, intraventricular pressure gradient (IVPG) was presented as a non-invasive, highly sensitive preload-independent diastolic function parameter to assess cardiac function, especially during cardiomyopathy. However, there have not been any investigations demonstrating the feasibility of IVPG in the evaluation of post-infarction chronic CHF.

Purpose

This study aimed to investigate the utility of IVPG to assess the heart function in a rat model with chronic CHF following MI with evaluating its capacity to predict these changes.

Methods

Fifty male rats were included. MI was induced via ligation of the left anterior descending artery (LAD) at the level of the atrioventricular junction (MI animals, n = 35). Sham animals were subjected to the same left thoracotomy procedure without LAD ligation (Sham animals, n = 15). Transthoracic conventional echocardiography and colour M-mode echocardiography (CMME) for IVPG were performed in all animals 6 months post-surgery. The next day, animals were anesthetized, ventilated, and euthanized after the recording of hemodynamics. The heart weight, and lung and liver wet-to-dry weight ratios were recorded. J-tree cluster-analysis was performed based on ten echocardiographic variables indicative of CHF.

Results

Based on the cluster analysis, animals were joined into two clusters; CHF+ (n = 22) and named MI/HF+, and CHF- (n = 28) that was joined from sham (n = 15), and MI/HF- (n = 13). MI/HF+ presented the most severe anatomical and echocardiographic changes indicative of CHF with significant reduction of all IVPG indices and impairment of the hemodynamics. The IVPG indices were significantly (P< 0.0001) correlated with the anatomical and echocardiographic findings, LVDP, LVEDP, HR, -dP/dtmin, and Tau. Meanwhile, LVSP was only significantly correlated with apical IVPG (R = 0.677, P = 0.022). dP/dtmax was significantly correlated with total IVPG, basal IVPG, and apical IVPG (R = 0.797, P = 0.017, R = 0.724, P = 0.003, and R = 0.652, P = 0.026 ; respectively). Moreover, total, basal, mid-to-apical, mid-, and apical IVPG were significant (P< 0.0001) predictors of chronic CHF following MI.

Conclusion

Compared to the structural, and functional indices of conventional echocardiography, IVPG derived from CMME could provide a substantial non-invasive tool to diagnose and predict CHF after long-term MI.

Upcycling of Hazardous Metals and PET Waste derived Metal-Organic Frameworks: A Review in Recent Progress and Prospects

An intense increase in non-biodegradable plastics and waste metals is an immediate threat to the world and needs to be addressed urgently. There are several strategies deployed to control, eliminate,...

A randomized, controlled trial of once-weekly teriparatide injection versus alendronate in patients at high risk of osteoporotic fracture: primary results of the Japanese Osteoporosis Intervention Trial-05

In this randomized, controlled trial, treatment with once-weekly subcutaneous injection of teriparatide for 72 weeks was found to be associated with a significant reduction in the incidence of morphometric vertebral fractures compared with alendronate in women with primary osteoporosis who were at high risk of fracture.

INTRODUCTION

To determine whether the anti-fracture efficacy of teriparatide is superior to that of alendronate, a prospective, randomized, open-label, blinded-endpoint trial was performed.

METHODS

Japanese women aged at least 75 years were eligible for the study if they had primary osteoporosis and were at high risk of fracture. Patients were randomly assigned in a 1:1 ratio to receive sequential therapy (once-weekly subcutaneous injection of teriparatide 56.5 μg for 72 weeks followed by alendronate for 48 weeks) or monotherapy with alendronate for 120 weeks. The primary endpoint was the incidence of morphometric vertebral fractures at 72 weeks (at the end of teriparatide treatment).

RESULTS

Between October 2014 and December 2017, 1011 patients (505 in the teriparatide group and 506 in the alendronate group) were enrolled. Of these, 778 patients (351 and 427, respectively) were included in the primary analysis. The incidence of morphometric vertebral fractures was significantly lower in the teriparatide group (56 per 419.9 person-years, annual incidence rate 0.1334) than in the alendronate group (96 per 553.6 person-years, annual incidence rate 0.1734), with a rate ratio of 0.78 (95% confidence interval 0.61 to 0.99, P = 0.04). In both groups, adverse events were most frequently reported in the following system organ classes: infections and infestations, gastrointestinal disorders, and musculoskeletal and connective tissue disorders.

CONCLUSION

Once-weekly subcutaneous injection of teriparatide significantly reduced the incidence of morphometric vertebral fractures compared with alendronate in women with primary osteoporosis who were at high risk of fracture.

TRIAL REGISTRATION

jRCTs031180235 and UMIN000015573, March 12, 2019.

High-dose-rate brachytherapy using inverse planning optimization with tandem and ovoid applicators for locally advanced cervical cancer: a simulation study

The purpose of this study was to evaluate the dosimetric advantage of inverse planning optimization (IPO) in locally advanced cervical cancer using high-dose-rate (HDR) brachytherapy (BT). IPO was compared with point A plan and geometric optimization (GO). The three planning methods were evaluated using doses to the virtual organ-at-risk (OAR) and D90 (the minimum dose covering of 90% of the volume) to the virtual high-risk clinical target volume (HR-CTV) based on quantitative analysis. HR-CTV structures measuring 38.5 cm³ and 59.5 cm³ were created based on the outcomes of a European Group cohort study. The HR-CTVs were located either at the center of the cervix (cervical center model) or shifted toward the left (extensive disease model). The distances from the HR-CTVs to the rectum were set at 0 mm, 3 mm, 5 mm, 8 mm, 10 mm, and 15 mm. We analyzed 336 conditions in this study. All doses were evaluated by conversion to doses in 2-Gy fractions of conventional radiotherapy. The D90 of the HR-CTV using GO and IPO could achieve the desired dose in all conditions, providing better results than that of point A plan. IPO makes it possible to deliver a sufficient dose for the D90 of the HR-CTV while reducing OAR doses with smaller HR-CTV values (< 38.5 cm³) in HDR BT. However, taking into consideration the whole treatment planning time, IPO should be used only when the HR-CTV-to-rectum distance is ≤ 5 mm, and the use of GO cannot spare OARs.

Verification of KURBUC-based ion track structure mode for proton and carbon ions in the PHITS code

The particle and heavy ion transport code system (PHITS) is a general-purpose Monte Carlo radiation transport simulation code. It has the ability to handle diverse particle types over a wide range of energy. The latest PHITS development enables the generation of track structure for proton and carbon ions (¹H⁺, ¹²C⁶⁺) based on the algorithms in the KURBUC code, which is considered as one of the most verified track-structure codes worldwide. This ion track-structure mode is referred to as the PHITS-KURBUC mode. In this study, the range, radial dose distributions, and microdosimetric distributions were calculated using the PHITS-KURBUC mode. Subsequently, they were compared with the corresponding data obtained from the original KURBUC and from other studies. These comparative studies confirm the successful inclusion of the KURBUC code in the PHITS code. As results of the synergistic effect between the macroscopic and microscopic radiation transport codes, this implementation enabled the detailed calculation of the microdosimetric and nanodosimetric quantities under complex radiation fields, such as proton beam therapy with the spread-out Bragg peak.

Classification of the colonic splenic flexure based on three-dimensional CT analysis

Background

Mobilization of the splenic flexure can be a challenging surgical step in colorectal surgery. This study aimed to classify the splenic flexure based on the three-dimensional (3D) coordinates of the splenic hilum and left renal hilum. This classification was used to compare splenic flexure mobilization during colorectal resection.

Methods

CT images of patients with colorectal cancer treated between April 2018 and December 2019 were analysed retrospectively. 3D mutual positioning of the splenic flexure from the ligament of Treitz to the splenic hilum or the left renal hilum was used to classify patients into three groups using cluster analysis. The difference in the procedure time between groups was also analysed in a subset of patients undergoing laparoscopic colectomy with complete splenic flexure mobilization.

Results

Of 515 patients reviewed, 319 with colorectal cancers were included in the study and categorized based on the 3D coordinates of the splenic hilum and left renal hilum as caudal (100 patients), cranial (118) and lateral (101) positions. Male sex (P < 0.001), older age (P = 0.004) and increased bodyweight (P = 0.043) were independent characteristics of the lateral group in multiple logistic regression analysis. Thirty-four patients underwent complete splenic flexure mobilization during the study period; this took significantly longer (mean 78.7 min) in the lateral group than in the caudal and cranial groups (41.8 and 43.2 min respectively; P = 0.006).

Conclusion

Locating the splenic flexure using 3D coordinates could be helpful in predicting a longer duration for mobilization of the splenic flexure.

Modification and Validation of the DREIDING Force Field for Molecular Liquid Simulations (DREIDING-UT)

In this study, we modified Lennard-Jones (LJ) parameters and point-charge parameters of the DREIDING force field (the modified force-field model is named DREIDING-UT). While the original LJ parameters of DREIDING were derived through an analytical formula to reproduce the potential depths and the equilibrium lengths of the Buckingham potentials of DREIDING/X6, the modified LJ parameters were derived through the least square fitting of the Buckingham potentials. Because the Gasteiger-Marsili (GM) charges of the original DREIDING underestimated electrostatic interactions, we replaced it with the restrained electrostatic potential (RESP) charges calculated from the ab initio wavefunctions, taking the dynamic electron correlation and solvation effects into account. To confirm how the modified force field works, we conducted molecular dynamics (MD) simulations of typical liquids. It was found that the densities and self-diffusion coefficients of the DREIDING-UT model agreed with the experimental ones much better than those of the original model.

Utility of computed tomography and 18 F-fluorodeoxyglucose with positron emission tomography/computed tomography for distinguishing appendiceal mucocele caused by mucinous adenocarcinoma from other pathologies

AIM

Differentiating appendiceal mucocele with mucinous adenocarcinoma from other pathologies before surgery is difficult. The objective of this study was to evaluate the utility of CT and ¹⁸ F-fluorodeoxyglucose (FDG) with positron emission tomography (PET)/CT for differentiating mucinous adenocarcinoma of appendiceal mucocele from other pathologies.

METHOD

The study included 25 patients who underwent surgery for clinically diagnosed appendiceal mucoceles detected on CT at the University of Tokyo Hospital. Among these patients, 19 underwent FDG-PET/CT preoperatively. We compared features of the CT imaging findings and maximum standard uptake values (SUV_max ) detected by FDG-PET/CT between mucocele with mucinous adenocarcinoma and other pathologies.

RESULTS

A total of 13 men (52%) and 12 women (48%) were included in this study, with a median age of 65 years (range 34-83). There were six patients (24%) with pathologically confirmed mucinous adenocarcinoma, 15 patients (60%) with appendiceal mucinous neoplasm and four patients (16%) with simple mucocele caused by chronic inflammation. On the CT findings, wall irregularity was the only significant feature for the two groups in this study (83.3% vs 0.0%, P < 0.01). There was a significant difference in the SUV_max levels on PET/CT between the two groups (100.0% vs 20.0%, P < 0.01).

CONCLUSION

Distinguishing between mucocele with mucinous adenocarcinoma and other pathologies using imaging modalities is challenging. Our results suggest that wall irregularity on CT and elevated SUV_max on PET/CT are useful factors that can be employed for such discrimination.

Effects of preceding endoscopic treatment on laparoscopic surgery for early rectal cancer

AIM

Endoscopic treatment for rectal cancer, such as endoscopic mucosal resection and endoscopic submucosal dissection, causes inflammation, oedema and fibrosis in the surrounding tissue. However, little is known about the effect of these endoscopic therapies on salvage laparoscopic rectal surgery. The objective of this retrospective cohort study was to analyse the effect of preceding endoscopic treatment on the outcomes of laparoscopic surgery for rectal cancer.

METHOD

We analysed 53 patients who underwent laparoscopic surgery for rectal cancer with clinical Tis or T1 at our department between May 2011 and June 2019. Data from 30 patients who underwent laparoscopic surgery after preceding endoscopic treatment (Group E + S) were compared with those of 23 patients who underwent laparoscopic surgery alone (Group S).

RESULTS

There was no significant difference between the groups with respect to preoperative details. The mean operative time tended to be longer in Group E + S, and the volume of intra-operative blood loss was greater in Group E + S than in Group S (median 63 ml vs 10 ml, P = 0.049). There were no significant differences between the groups in other surgical parameters or oncological outcomes.

CONCLUSION

Laparoscopic surgery after endoscopic treatment for rectal cancer may be difficult due to an increased risk of intra-operative bleeding. Long-term prognosis after surgery was not affected by preceding endoscopic treatment in rectal cancer.

Transfer of orbital angular momentum of light to plasmonic excitations in metamaterials

The emergence of the vortex beam with orbital angular momentum (OAM) has provided intriguing possibilities to induce optical transitions beyond the framework of the electric dipole interaction. The uniqueness stems from the OAM transfer from light to material, as demonstrated in electronic transitions in atomic systems. In this study, we report on the OAM transfer to electrons in solid-state systems, which has been elusive to date. Using metamaterials (periodically textured metallic disks), we show that multipolar modes of the surface electromagnetic excitations (so-called spoof localized surface plasmons) are selectively induced by the terahertz vortex beam. Our results reveal selection rules governed by the conservation of the total angular momentum, which is confirmed by numerical simulations. The efficient transfer of light's OAM to elementary excitations in solid-state systems at room temperature opens up new possibilities of OAM manipulation.

Vascular anatomy of the splenic flexure, focusing on the accessory middle colic artery and vein

AIM

Recently, the accessory middle colic artery (AMCA) has been recognized as the vessel that supplies blood to the splenic flexure. However, the positional relationship between the AMCA and inferior mesenteric vein (IMV) has not been evaluated. Herein, we aimed to evaluate the anatomy of the AMCA and the splenic flexure vein (SFV).

METHOD

Two hundred and five patients with colorectal cancer who underwent enhanced CT preoperatively were enrolled in the present study. The locations of the AMCA and IMV were evaluated, focusing on the positional relationship between the vessels and pancreas - below the pancreas or to the dorsal side of the pancreas.

RESULTS

The AMCA was observed in 74 (36.1%) patients whereas the SFV was found in 177 (86.3%) patients. The left colic artery (LCA) was the major artery accompanying the SFV in 87 (42.4%) of patients. The AMCA accompanied the SFV in 65 (32.7%) patients. In 15 (7.8%) patients, no artery accompanied the SFV. The origin of the AMCA was located on the dorsal side of the pancreas in 15 (20.3%) of these 74 patients. Similarly, the destination of the IMV was located on the dorsal side of the pancreas in 65 (31.7%) of patients.

CONCLUSION

The SFV was observed in most patients, and the LCA or AMCA was the common accompanying artery. In some patients these vessels were located on the dorsal side of the pancreas and not below it. Preoperative evaluation of this anatomy may be beneficial for lymph node dissection during left-sided hemicolectomy.

Possible Lightest Ξ Hypernucleus with Modern ΞN Interactions

Experimental evidence exists that the Ξ-nucleus interaction is attractive. We search for NNΞ and NNNΞ bound systems on the basis of the AV8 NN potential combined with either a phenomenological Nijmegen ΞN potential or a first principles HAL QCD ΞN potential. The binding energies of the three-body and four-body systems (below the d+Ξ and ^{3}H/^{3}He+Ξ thresholds, respectively) are calculated by a high precision variational approach, the Gaussian expansion method. Although the two ΞN potentials have significantly different isospin (T) and spin (S) dependence, the NNNΞ system with quantum numbers (T=0, J^{π}=1^{+}) appears to be bound (one deep for Nijmegen and one shallow for HAL QCD) below the ^{3}H/^{3}He+Ξ threshold. Experimental implications for such a state are discussed.

Images from the surface of asteroid Ryugu show rocks similar to carbonaceous chondrite meteorites

The near-Earth asteroid (162173) Ryugu is a 900-m-diameter dark object expected to contain primordial material from the solar nebula. The Mobile Asteroid Surface Scout (MASCOT) landed on Ryugu's surface on 3 October 2018. We present images from the MASCOT camera (MASCam) taken during the descent and while on the surface. The surface is covered by decimeter- to meter-sized rocks, with no deposits of fine-grained material. Rocks appear either bright, with smooth faces and sharp edges, or dark, with a cauliflower-like, crumbly surface. Close-up images of a rock of the latter type reveal a dark matrix with small, bright, spectrally different inclusions, implying that it did not experience extensive aqueous alteration. The inclusions appear similar to those in carbonaceous chondrite meteorites.

Hepatocellular carcinoma tumour burden score to stratify prognosis after resection

BACKGROUND

Although the Barcelona Clinic Liver Cancer (BCLC) staging system has been largely adopted in clinical practice, recent studies have emphasized the need for further refinement and subclassification of this system.

METHODS

Patients who underwent hepatectomy with curative intent for BCLC-0, -A or -B hepatocellular carcinoma (HCC) between 2000 and 2017 were identified using a multi-institutional database. The tumour burden score (TBS) was calculated, and overall survival (OS) was examined in relation to TBS and BCLC stage.

RESULTS

Among 1053 patients, 63 (6·0 per cent) had BCLC-0, 826 (78·4 per cent) BCLC-A and 164 (15·6 per cent) had BCLC-B HCC. OS worsened incrementally with higher TBS (5-year OS 77·9, 61 and 39 per cent for low, medium and high TBS respectively; P < 0·001). No differences in OS were noted among patients with similar TBS, irrespective of BCLC stage (61·6 versus 58·9 per cent for BCLC-A/medium TBS versus BCLC-B/medium TBS, P = 0·930; 45 versus 13 per cent for BCLC-A/high TBS versus BCLC-B/high TBS, P = 0·175). Patients with BCLC-B HCC and a medium TBS had better OS than those with BCLC-A disease and a high TBS (58·9 versus 45 per cent; P = 0·005). On multivariable analysis, TBS remained associated with OS among patients with BCLC-A (medium TBS: hazard ratio (HR) 2·07, 95 per cent c.i. 1·42 to 3·02, P < 0·001; high TBS: HR 4·05, 2·40 to 6·82, P < 0·001) and BCLC-B (high TBS: HR 3·85, 2·03 to 7·30; P < 0·001) HCC. TBS could also stratify prognosis among patients in an external validation cohort (5-year OS 79, 51·2 and 28 per cent for low, medium and high TBS respectively; P = 0·010).

CONCLUSION

The prognosis of patients with HCC varied according to the BCLC stage but was largely dependent on the TBS.

Incidence of and risk factors for lymphocele formation after lateral pelvic lymph node dissection for rectal cancer: a retrospective study

AIM

Pelvic lymphocele is a common complication that develops after pelvic lymph node dissection. The incidence of pelvic lymphocele formation has been reported to be 10.5-51% after gynaecological or urological procedures. However, no evidence has been reported thus far with regard to the development of pelvic lymphocele following lateral pelvic lymph node dissection (LPND) for low rectal cancer. The aim of this study was to investigate the incidence of and risk factors for lymphocele formation after LPND for low rectal cancer and to examine its clinical management.

METHOD

We retrospectively analysed the incidence of and risk factors for pelvic lymphocele formation after LPND for rectal cancer in our hospital between January 2012 and December 2017. We also compared the size of the lymphocele between asymptomatic and symptomatic patients by using CT volumetry and examined its clinical management.

RESULTS

A total of 30 out of 98 patients (30.8%) developed pelvic lymphocele after rectal LPND. The number of resected nodes was significantly higher in patients with a pelvic lymphocele (P < 0.01). The median volume was significantly higher in patients with symptomatic pelvic lymphocele (P = 0.011). Among the nine symptomatic patients, two underwent CT-guided drainage, one underwent transurethral ureteral stent placement and one underwent laparoscopic marsupialization.

CONCLUSION

It is essential to keep in mind the possibility of pelvic lymphocele formation during follow-up of patients who undergo LPND, and to consider an appropriate treatment when these patients are symptomatic.

Obstruction is associated with perineural invasion in T3/T4 colon cancer

AIM

Perineural invasion (PNI) is a risk factor for recurrence and metastasis and consequently leads to decreased survival in patients with various malignancies. Recent studies showed that stent placement in obstructive colon cancer increases the frequency of PNI. We hypothesized that mechanical stress including obstruction itself may be associated with PNI.

METHOD

We retrospectively reviewed 496 patients with pathological T3 or T4 colon cancer who did not receive preoperative treatment. Data were collected from medical charts and pathological findings. The relationships between PNI and other clinicopathological factors were analysed using univariate and multivariate analyses.

RESULTS

PNI was observed in 239 (48%) patients. Obstruction was markedly more frequent in PNI-positive cancer (39%) than in PNI-negative cancer (24%, P = 0.0003). Multivariate analyses identified obstruction as one of the significant factors associated with PNI (OR 1.68, P = 0.028). Moreover, in 414 patients without distant metastasis who underwent complete resection, PNI was an independent factor associated with poor recurrence-free survival (hazard ratio 2.35, P = 0.003). The coexistence of PNI and obstruction resulted in greater decreases in recurrence-free survival than PNI-negative and/or non-obstructive cases.

CONCLUSION

Our results suggest that obstruction is associated with PNI and consequently contributes to an increased postoperative recurrence in colon cancer.

Improvement of Hepatic Functions by Spheroids Coculture with Fibroblasts in 3D Silica Nonwoven Fabrics

In order to realize organ-on-a-chip as an effective tool for regenerative medicine and drug development, tissue-mimic cell culture methods which promote liver-specific function for long period have been developed. We have previously demonstrated that coculture of hepatocyte spheroids on fibroblasts using micropatterned substrate improved the hepatic functions due to the heterotypic cell-cell interactions and paracrine signaling from each other. In addition, hepatocyte function cultured as monolayer was also promoted in separately coculture with fibroblasts cultured as monolayer, and it is more improved in separately coculture with fibroblasts in 3D silica nonwoven fabrics. In this study, separately coculture of hepatocyte spheroids with fibroblasts cultured on 3D silica nonwoven fabrics was estimated for further improvement of hepatocyte functions. The hepatic function cocultured with fibroblast was more promoted than mono spheroids culture. The functional enhancement was significantly most improved in separately coculture with fibroblast in 3D silica nonwoven fabrics. Thus, these results were suggested that 3D culture of fibroblasts in 3D silica nonwoven fabrics increased the heterotypic secretion of paracrine factors, and it is essential for improved hepatic performance.

A SNP in a Steroidogenic Enzyme Is Associated with Phenotypic Sex in Seriola Fishes

Vertebrate sex development consists largely of two processes: "sex determination," the initial bifurcation of sexual identity, and "sex differentiation," which subsequently facilitates maleness or femaleness according to the sex determination signal. Steroid hormones promote multiple types of sexual dimorphism in eutherian mammals and avians [1-3], in which they are indispensable for proper sex differentiation. By contrast, in many poikilothermic vertebrates, steroid hormones have been proposed to be key players in sex determination as well as sex differentiation [4-8]. This hypothesis was introduced more than 50 years ago but has never been rigorously tested due to difficulties in discriminating the roles of steroids in sex determination and differentiation. We found that a missense SNP in the gene encoding the steroidogenic enzyme 17β-hydroxysteroid dehydrogenase 1 (Hsd17b1) was perfectly associated with ZZ/ZW sex determination in Seriola fishes. Biochemical analyses revealed that a glutamate residue present specifically in Z-type HSD17B1 attenuated interconversion between 17-keto and 17β-hydroxy steroids relative to the allelic product from the W chromosome, which harbors glycine at that position, by disrupting the hydrogen bond network between the steroid and the enzyme's catalytic residues. Hsd17b1 mRNA is constitutively expressed in undifferentiated and differentiating gonads of both genotypic sexes, whereas W-type mRNA is expressed only in genotypic females. Meanwhile, Cyp19a1 is predominantly expressed in differentiating ovary. We conclude that the combination of Hsd17b1 alleles determines sex by modulating endogenous estrogen levels in Seriola species. These findings strongly support the long-standing hypothesis on steroids in sex determination.

New precise measurements of muonium hyperfine structure at J-PARC MUSE

High precision measurements of the ground state hyperfine structure (HFS) of muonium is a stringent tool for testing bound-state quantum electrodynamics (QED) theory, determining fundamental constants of the muon magnetic moment and mass, and searches for new physics. Muonium is the most suitable system to test QED because both theoretical and experimental values can be precisely determined. Previous measurements were performed decades ago at LAMPF with uncertainties mostly dominated by statistical errors. At the J-PARC Muon Science Facility (MUSE), the MuSEUM collaboration is planning complementary measurements of muonium HFS both at zero and high magnetic field. The new high-intensity muon beam that will soon be available at H-Line will provide an opportunity to improve the precision of these measurements by one order of magnitude. An overview of the different aspects of these new muonium HFS measurements, the current status of the preparation for high-field measurements, and the latest results at zero field are presented.

Three-dimensional localization spectroscopy of individual nuclear spins with sub-Angstrom resolution

Nuclear magnetic resonance (NMR) spectroscopy is a powerful method for analyzing the chemical composition and molecular structure of materials. At the nanometer scale, NMR has the prospect of mapping the atomic-scale structure of individual molecules, provided a method that can sensitively detect single nuclei and measure inter-atomic distances. Here, we report on precise localization spectroscopy experiments of individual 13C nuclear spins near the central electronic sensor spin of a nitrogen-vacancy (NV) center in a diamond chip. By detecting the nuclear free precession signals in rapidly switchable external magnetic fields, we retrieve the three-dimensional spatial coordinates of the nuclear spins with sub-Angstrom resolution and for distances beyond 10 Å. We further show that the Fermi contact contribution can be constrained by measuring the nuclear g-factor enhancement. The presented method will be useful for mapping atomic positions in single molecules, an ambitious yet important goal of nanoscale nuclear magnetic resonance spectroscopy.

Evaluation of the vascular anatomy of the left-sided colon focused on the accessory middle colic artery: a single-centre study of 734 patients

AIM

Surgery for colorectal cancer located in the splenic flexure is difficult to perform because of the complex anatomy. Recently, in addition to the middle colic artery and left colic artery (LCA), the accessory middle colic artery (AMCA) has been recognized as a feeding artery for the left-sided colon. This study aimed to evaluate the vascular anatomy of the splenic flexure focusing on the AMCA in a large number of patients.

METHOD

A total of 734 patients who underwent CT before surgery for colorectal cancer were enrolled. We retrospectively evaluated the vascular anatomy using both two- and three-dimensional CT angiography.

RESULTS

The AMCA existed in 36.4% of the cases (n = 267). In many cases, it originated from the superior mesenteric artery (n = 228, 85.4%). The AMCA had a common trunk with the transverse pancreatic artery in 54 patients (20.2%). The frequency of the presence of the AMCA was associated with the branching pattern of the LCA, and was more frequent when the LCA was absent (P < 0.001).

CONCLUSION

The presence of the AMCA is not rare and the AMCA has some branching patterns; therefore, recognizing it preoperatively and intra-operatively is important, being especially careful when the LCA is absent.

Osteogenic Differentiation of Bone Marrow-Derived Mesenchymal Stem Cells in Electrospun Silica Nonwoven Fabrics

Silica nonwoven fabrics (SNFs) with enough mechanical strength are candidates as implantable scaffolds. Culture of cells therein is expected to affect the proliferation and differentiation of the cells through cell-cell and cell-SNF interactions. In this study, we examined three-dimensional (3D) SNFs as a scaffold of mesenchymal stem cells (MSCs) for bone tissue engineering applications. The interconnected highly porous microstructure of 3D SNFs is expected to allow omnidirectional cell-cell interactions, and the morphological similarity of a silica nanofiber to that of a fibrous extracellular matrix can contribute to the promotion of cell functions. 3D SNFs were prepared by the sol-gel process, and their mechanical properties were characterized by the compression test and rheological analysis. In the compression test, SNFs showed a compressive elastic modulus of over 1 MPa and a compressive strength of about 200 kPa. These values are higher than those of porous polystyrene disks used for in vitro 3D cell culture. In rheological analysis, the elastic modulus and fracture stress were 3.27 ± 0.54 kPa and 25.9 ± 8.3 Pa, respectively. Then, human bone marrow-derived MSCs were cultured on SNFs, and the effects on proliferation and osteogenic differentiation were evaluated. The MSCs seeded on SNF proliferated, and the thickness of the cell layer became over 80 μm after 14 days of culture. The osteogenic differentiation of MSCs on SNFs was induced by the culture in the commercial osteogenic differentiation medium. The alkaline phosphatase activity of MSCs on SNFs increased rapidly and remained high up to 14 days and was much higher than that on two-dimensional tissue culture-treated polystyrene. The high expression of RUNX2 and intense staining by alizarin red s after differentiation supported that SNFs enhanced the osteogenic differentiation of MSCs. Furthermore, permeation analysis of SNFs using fluorescein isothiocyanate-dextran suggested a sufficient permeability of SNFs for oxygen, minerals, nutrients, and secretions, which is important for maintaining the cell viability and vitality. These results suggested that SNFs are promising scaffolds for the regeneration of bone defects using MSCs, originated from highly porous and elastic SNF characters.

Variation in Activities of Non-Plasmin Fibrinolytic Proteinase and Plasminogen-Activator in the Lung and Spleen Induced by Bacterial Endotoxin in Rats with Special Reference to the Effects of MD-805

The behavior of direct fibrinolytic (non-plasmin) proteinase activity and plasminogen-activator activity in the lung and spleen was investigated in rats after a single intravenous injection of bacterial endotoxin, and the influence of thrombin inhibitors on the effects of the endotoxin was assessed.

The non-plasmin fibrinolytic activitiy was markedly increased following a decrease of plasminogen-activator in the lung. In addition, variations in hematological parameters, i.e. a decrease of platelet count, fibrinogen level and antithrombin III, and an increase of blood urea nitrogen and euglobulin fibrinolytic activity, were induced by the injection, indicating the occurrence of disseminated intravascular coagulation.

In comparative studies on the effects of the endotoxin injection and thrombin infusion, in the lung and spleen an increase of fibrinolytic proteinase activity was induced in a similar manner; the plasminogen-activator activity in the lung was decreased by the endotoxin injection but not decreased by the thrombin infusion.

In prevention studies with heparin and MD-805, the latter was found to prevent the decrease of either fibrinogen or platelet count. However, the former failed to prevent the decrease of platelet count although that of the fibrinogen level was prevented. Heparin and MD-805 exerted no preventive effect on the endotoxin-induced variations of proteinase activity and plasminogen-activator activity in the lung.