Maternal immunoglobulins are distributed in the offspring's brain to support the maintenance of cortical interneurons in the postnatal period

It is known that maternal immunoglobulins (Igs) are transferred to the offspring across the placenta. However, receiving maternal Igs, especially before the blood-brain barrier (BBB) is formed in the offspring's brain, carries the risk of transferring some brain-reactive Igs. It is thus hypothesized that there may be some unknown benefit to the offspring's brain that overweighs this risk. In this study, we show that the Ig detected in the embryonic/perinatal mouse brain is IgG not produced by the pups themselves, but is basically transferred from the mother across the placenta using the neonatal Fc receptor (FcRn) during embryonic stages. The amount of IgG in the brain gradually decreases after birth, and almost disappears within 3 weeks postnatally. IgG is detected on axon bundles, microglia, and some meningeal cells, including border-associated macrophages (BAMs), endothelial cells, and fibroblasts. Using Fcer1g knock-out (KO) mice, we show that BAMs and microglia receive maternal IgG in an Fc receptor γ chain (FcRγ)-dependent manner, but IgG on other meningeal cells and axon bundles is received independently of the FcRγ. These results suggest that maternal IgG may be used in multiple ways by different mechanisms. In maternal IgG-deficient mice, the number of interneurons in the cerebral cortex is not altered around birth but is reduced postnatally, suggesting that receipt of maternal IgG is necessary for the maintenance of cortical interneurons in the postnatal period. These data suggest that maternal IgG has an important function in the developing brain, where neither obvious inflammation nor infection is observed.

Effect of Vinyl Acetate, Glass Fibers Contents, and Buffer Space on EVA's Mechanical Property and Shock Absorption Ability

OBJECTIVES

 The aim of the study was to evaluate the mechanical properties and impact absorption capacity of prototype materials comprising ethylene vinyl acetate (EVA) of different hardness reinforced using different amounts of glass fibers (GFs), considering a buffer space.

MATERIALS AND METHODS

Six prototype materials were made by adding E-GFs (5 and 10 wt%) to EVA with vinyl acetate (VA) contents of 9.4 wt% ("hard" or HA) and 27.5 wt% ("soft" or SO). Durometer hardness and tensile strength tests were performed to evaluate the mechanical properties of the materials. Moreover, an impact test was conducted using a customized pendulum impact tester to assess the impact absorption capacity (with or without a buffer space) of the specimens.

RESULTS

The mechanical properties of the prototypes, namely, durometer hardness, Young's modulus, and tensile strength, were significantly higher in the HA group than in the SO group, regardless of the presence or added amount of GFs. The addition of GFs, particularly in a large amount (10 wt%), significantly increased these values. In terms of the impact absorption capacity, the original hardness of the EVA material, that is, its VA content, had a more substantial effect than the presence or absence of GFs and the added amount of GFs. Interestingly, the HA specimens with the buffer space exhibited significantly higher impact absorption capacities than the SO specimens. Meanwhile, the SO specimens without the buffer space exhibited significantly higher impact absorption capacities than the HA specimens. Moreover, regardless of the sample material and impact distance, the buffer space significantly improved impact absorption. In particular, with the buffer space, the impact absorption capacity increased with the added amount of GFs.

CONCLUSION

The basic mechanical properties, including durometer hardness, Young's modulus, and tensile strength, of the EVA prototype were significantly increased by reducing the amount of VA regardless of the presence or added amount of GFs. Adding GFs, particularly in large amounts, significantly increased the values of aforementioned mechanical properties. Impact absorption was significantly affected by the hardness of the original EVA material and enhanced by the addition of the buffer space. The HA specimen had a high shock absorption capacity with the buffer space, and the SO specimen had a high shock absorption capacity without the buffer space. With the buffer space, impact absorption improved with the amount of added GFs.

Time-Lapse Imaging of Migrating Neurons and Glial Progenitors in Embryonic Mouse Brain Slices

During the development of the cerebral cortex, neurons and glial cells originate in the ventricular zone lining the ventricle and migrate toward the brain surface. This process is crucial for proper brain function, and its dysregulation can result in neurodevelopmental and psychiatric disorders after birth. In fact, many genes responsible for these diseases have been found to be involved in this process, and therefore, revealing how these mutations affect cellular dynamics is important for understanding the pathogenesis of these diseases. This protocol introduces a technique for time-lapse imaging of migrating neurons and glial progenitors in brain slices obtained from mouse embryos. Cells are labeled with fluorescent proteins using in utero electroporation, which visualizes individual cells migrating from the ventricular zone with a high signal-to-noise ratio. Moreover, this in vivo gene transfer system enables us to easily perform gain-of-function or loss-of-function experiments on the given genes by co-electroporation of their expression or knockdown/knockout vectors. Using this protocol, the migratory behavior and migration speed of individual cells, information that is never obtained from fixed brains, can be analyzed.

Interactions between neural cells and blood vessels in central nervous system development

The sophisticated function of the central nervous system (CNS) is largely supported by proper interactions between neural cells and blood vessels. Accumulating evidence has demonstrated that neurons and glial cells support the formation of blood vessels, which in turn, act as migratory scaffolds for these cell types. Neural progenitors are also involved in the regulation of blood vessel formation. This mutual interaction between neural cells and blood vessels is elegantly controlled by several chemokines, growth factors, extracellular matrix, and adhesion molecules such as integrins. Recent research has revealed that newly migrating cell types along blood vessels repel other preexisting migrating cell types, causing them to detach from the blood vessels. In this review, we discuss vascular formation and cell migration, particularly during development. Moreover, we discuss how the crosstalk between blood vessels and neurons and glial cells could be related to neurodevelopmental disorders.

Depletion of macrophages deteriorates bisphosphonate-related osteonecrosis of the jaw-like lesions in mice

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a potentially intractable disease with no definitive pathophysiology and no treatment and prevention strategies. This study aimed to investigate whether time-selective depletion of macrophages worsens BRONJ-like lesions in mice. A murine model of high-prevalence BRONJ-like lesions in combination with zoledronate/chemotherapeutic drug administration and tooth extraction was created according to the methods of our previous studies. Daily intra-oral submucosal administration of clodronate-loaded liposomes, which temporarily depletes systemic macrophages, was performed immediately after tooth extraction. Spleens, femora, tibiae, and maxillae were dissected 2 weeks after extraction to evaluate BRONJ-like lesions and systemic conditions by micro-computed tomography analysis, histomorphometric and immunofluorescent analyses, and serum chemistry with ELISA. Depletion of macrophages significantly decreased the numbers of local and systemic macrophages and osteoclasts on the bone surface, which markedly worsened osseous healing, with increased necrotic bone and empty lacunae in the existing alveolar bone and newly formed bone in the extraction sockets, and soft tissue healing, with decreased collagen production and increased infiltration of polymorphonuclear cells. Interestingly, the depletion of macrophages significantly shifted macrophage polarization to M1 macrophages through an increase in F4/80+CD38+ M1 macrophages and a decrease in F4/80+CD163+ M2 macrophages, with decreases in the total number of F4/80+ macrophages. These data demonstrated that severe inhibition of osteoclasts in bone tissue and polarization shifting of macrophages in soft tissue are essential factors associated with BRONJ.

Plant size, latitude, and phylogeny explain within-population variability in herbivory

Interactions between plants and herbivores are central in most ecosystems, but their strength is highly variable. The amount of variability within a system is thought to influence most aspects of plant-herbivore biology, from ecological stability to plant defense evolution. Our understanding of what influences variability, however, is limited by sparse data. We collected standardized surveys of herbivory for 503 plant species at 790 sites across 116° of latitude. With these data, we show that within-population variability in herbivory increases with latitude, decreases with plant size, and is phylogenetically structured. Differences in the magnitude of variability are thus central to how plant-herbivore biology varies across macroscale gradients. We argue that increased focus on interaction variability will advance understanding of patterns of life on Earth.

Phase II Clinical Trial of Hypofractionated Image-Guided Proton Therapy with 12 Fractions for Prostate Cancer

PURPOSE/OBJECTIVE(S)

Towards hypofractionated proton therapy for prostate cancer for improving convenience for patients to receive treatment and improving therapeutic efficacy, image-guided technique with hydrogel spacer solved the late gastrointestinal toxicity, but it is unclear whether acute genitourinary (GU) toxicity is acceptable. The aim of this phase II study was to evaluate the safety and efficacy of hypofractionated image-guided proton therapy (IGPT) with 12 fractions for prostate cancer.

MATERIALS/METHODS

Eligibility criteria were as follows: (1) histologically confirmed primary prostate cancer; (2) T1-T3bN0M0 staged by (UICC TNM8th); (3) ECOG-PS ≤ 2; (4) age ≥ 20 years; (5) no serious underlying disease or other cancers; (6) technically capable of proton therapy, and (7) written informed consent. Primary endpoint was the ratio of grade 2 or more acute genitourinary toxicity. We used the modified CTCAE grading of grade 2 GU toxicities, in which prescribing two and more types of drugs for dysuria within 3 months of the start of radiation was considered to indicate grade 2 GU toxicity. A phase II trial was planned based on the minimax Simon's two-stage design with a significance level of 0.05 and a power of 90%. The acceptable incidence is considered to be less than 5%, and the unacceptable incidence is considered to be more than 15%. A total of 83 patients is required for completion of the trial (7 patients or fewer). After evaluating the primary endpoint in 83 patients, 217 additional patients were registered and a total of 300 patients were registered in order to further examine the safety and efficacy. The prescribed dose to the isocenter was 51.6 GyRBE in 12 fractions (4 days a week).

RESULTS

From January 2020 to March 2021, 30, 53, and 217 patients (total 300) were enrolled. The patient characteristics were as follows: median age, 70 (48-83) years; low/intermediate/high risk, 44/132/124. Forty-nine and 38 patients had benign prostatic hyperplasia and diabetes mellitus, respectively. Grade 2 acute GU toxicities were observed in 1, 5 and 13 patients, respectively (total 6.3%). No grade 3 or higher acute GU toxicities were observed. However, urinary retention during IGPT, which was not previously observed, was observed in 3 cases, and temporary urethral catheterization was performed (Grade 2). Most of the acute GU toxicity tended to improve at 1 month after IGPT, and almost improved at 3 months. Mean score deteriorations beyond the minimum clinically important difference threshold (1/2 SD) were observed only at 1 month in the following scales: summary (-6.0), bother (-7.0), and irritative/obstructive (-6.3).

CONCLUSION

Hypofractionated IGPT with 12 fractions for prostate cancer is well tolerated in acute GU toxicities. Longer follow-up is necessary to evaluate the efficacy and late toxicities. Further investigation of hypofractionated IGPT with 12 fractions for prostate cancer is warranted. Since April 2021, an additional 1000 cases of prospective registration study have been conducted.

Quality of Palliative Radiation Therapy Assessed Using Quality Indicators: A Multicenter Survey

PURPOSE/OBJECTIVE(S)

Clinical practice is not always performed in accordance with guideline recommendations. Quality indicators (QIs) are valuable tools for evaluating the quality of healthcare systems. We sought to identify potential gaps between clinical practice and evidence using QIs previously developed using a modified Delphi method.

MATERIALS/METHODS

We used seven QIs (Table 1) to assess the quality of radiation therapy for bone (BoM) and brain metastases (BrM) at 29 centers; 13 (45%) were academic (12 university hospitals and 1 cancer center) and 16 (55%) were nonacademic hospitals. Compliance rate was calculated as the percentage of patients for whom recommended medical care was conducted. Random effects models were used to estimate pooled compliance rates. Mixed effects models with a Q test were used to compare compliance rates between academic and nonacademic centers.

RESULTS

The estimates of the compliance rates with 95% confidence intervals are presented in Table 1. For BoM-1, the compliance rate was higher in academic hospitals (100% [100-100%]) than in non-academic hospitals (96% [89-100%]) (P = 0.021). For BrM-3, the compliance rate was lower in academic hospitals (92% [81-99%]) than in nonacademic hospitals (100% [98-100%]) (P = 0.016).

CONCLUSION

A quality assessment based on these seven QIs is feasible. Overall, compliance rates were high; however, for BoM-3, the practice remains to be improved in some centers. Based on BoM-4 compliance rates, steroids are infrequently used concurrently with radiation therapy for malignant spinal cord compression. Extended fractionation for BoM was less frequently performed in academic than in nonacademic centers. The initiation of radiation therapy for brain metastases was more frequently delayed in academic than in nonacademic centers.

Effects of Mouthguards on Skin Damage In Vitro Study

OBJECTIVE

 Mouthguards can prevent and reduce orofacial sports traumas, which occur to the players themselves. However, the effect of mouthguards on skin damage has not been clarified. The present study's purpose was to examine whether the mouthguard can reduce or prevent skin damage caused by teeth (including the difference in mouthguard thickness).

MATERIALS AND METHODS

 Pigskins, artificial teeth, and Ethylene-vinyl acetate (EVA) mouthguard blanks with 1.5- and 3.0-mm thickness were employed. Each of the two type mouthguards was produced in 10 replicates. Mouthguard incisal thickness and collision touch angle were measured on a PC using imaging software. A pendulum-type machine was used to apply impact. Strain gauges attached to the tooth and impacted plate were used to measure mouthguards' effect on impact stress. Also, a microscope was used to observe the after impacted skin condition, and the extent of damage was assessed as a score.

RESULTS

 The pigskin was ruptured in without mouthguard (NOMG) with presenting the highest damage score, whereas the complete rupture was not seen in the 1.5 mm MG, but the damage of the skin (defeat) was observed. No tissue change was found with the 3 mmMG. In both the flat plate and impact tooth strain, no significant difference was observed between NOMG and 1.5 mmMG. However, 3 mmMG had a significantly smaller value than the other two conditions. These results are likely to be strongly influenced by the mouthguard incisal thicknesses and collision touch angles differences.

CONCLUSION

 The present study results clarified that two different thickness mouthguards reduced the skin damage, and the thicker mouthguard showed more effectiveness. Therefore, mouthguards may prevent the wearer's stomatognathic system's trauma and avoid damage to the skin of other athletes they are playing with. This effect seems to be an essential basis for explaining the necessity of using mouthguards for others besides full-contact sports.

Improving light-cured intermediate resin for hard and space mouthguard using a glass fiber

BACKGROUND/AIMS

A light-cured intermediate material is useful for fabricating a hard insert and a buffer space mouthguard (H&SMG). However, it requires improvement in its mechanical properties and shock-absorbing capacity. The aim of this study was to evaluate the mechanical properties of two prototype light-cured intermediate materials reinforced with glass fibers, and the impact absorption capacity and durability of H&SMGs made with the prototype intermediate materials.

MATERIALS AND METHODS

Two prototype materials containing long and microlength glass fibers in a light-cured intermediate material, Innerframe LC®, for H&SMG, were fabricated and tested. A three-point bending test was performed for evaluation of the mechanical properties. In addition, a shock absorption test was conducted using a customized pendulum impact testing machine to evaluate the H&SMGs' impact absorption capacity and durability.

RESULTS

Long and microlength glass fibers significantly improved flexural modulus and strength. H&SMGs made with these two glass fiber-containing materials had high impact absorption capacity against both low and high impact forces, while the mouthguards made with long glass fiber materials had the best results.

CONCLUSION

Long and microlength glass fibers with the prototype materials improved the mechanical properties of Innerframe LC® and the impact absorption capacity and durability of H&SMGs. H&SMGs made with the long glass fiber prototype materials had the best performance.

Heterozygous Dab1 null mutation disrupts neocortical and hippocampal development

Loss-of-function mutations in Reelin and DAB1 signaling pathways disrupt proper neuronal positioning in the cerebral neocortex and hippocampus, but the underlying molecular mechanisms remain elusive. Here we report that heterozygous yotari mice harboring a single autosomal recessive yotari mutation of Dab1 exhibited a thinner neocortical layer 1 than wild-type mice on postnatal day 7. However, a birth-dating study suggested that this reduction was not caused by failure of neuronal migration. In utero electroporation-mediated sparse labeling revealed that the superficial layer neurons of heterozygous yotari mice tended to elongate their apical dendrites within layer 2 than within layer 1. In addition, the CA1 pyramidal cell layer in the caudo-dorsal hippocampus was abnormally split in heterozygous yotari mice, and a birth-dating study revealed that this splitting was caused mainly by migration failure of late-born pyramidal neurons. Adeno-associated virus-mediated sparse labeling further showed that many pyramidal cells within the split cell had misoriented apical dendrites. These results suggest that regulation of neuronal migration and positioning by Reelin-DAB1 signaling pathways has unique dependencies on Dab1 gene dosage in different brain regions.Significance StatementDAB1 is a cytoplasmic adaptor protein essential for transmission of the extracellular Reelin signal to cytoplasmic proteins that regulate cortical development. In this study, we found that Dab1 is haplosufficient for the regulation of neuronal migration but haploinsufficient for control of layer 1 thickness in the cerebral neocortex. Alternatively, the migration of a subpopulation of hippocampal pyramidal neurons is sensitive to Dab1 gene haploinsufficiency. This study suggests that neural development in the cerebral neocortex and hippocampus are differentially sensitive to Dab1 gene dose.

Head injuries caused by contact with teeth during sports and exercise activities in Japanese schools during the period 2012-2018

BACKGROUND/AIMS

During sports activities, teeth-related contact can cause injury to both ally and opponent players, which can lead to potential infections and aesthetic problems. However, the extent of such injuries remains unclear. This study aimed to clarify the frequency and situation of head injuries caused by teeth (HICBT) occurring under the supervision of schools in Japan.

MATERIALS AND METHODS

HICBT records were extracted from the Japan Sport Council data on head injuries occurring reported during the 7-year period from 2012 to 2018 under the supervision of schools in Japan.

RESULTS

Of the total 463527 head injury cases during the study period, 4495 cases (approximately 1%) were HICBT. Of the HICBT cases, 3650 (81.20%) were related to sports and athletic activity. Such injuries were reported to occur most often during basketball with a rate of 57.07 and 50.43%; soccer/futsal was the next most common sport with a rate of 13.38 and 24.01% in junior high school and high school students. Tag games were responsible for a similar number of HICBT cases at 22.73 and 39.03% in kindergartens and elementary school students.

CONCLUSION

A total of 4495 cases of HICBT were identified, accounting for about 1% of all head injuries under the supervision of schools in Japan during the study period. This result reminds us that our teeth could be the weapon against the around players during sports events. HICBTs occurring during basketball and soccer/futsal, in which mouthguards are not mandatory, were conspicuous among junior and senior high school students. Active use of mouthguards in various sports will protect players as well as their teammates and opponents. Sports dentists should encourage the revision of rules, such as mandating the use of mouthguards, in popular sports with a high incidence of HICBT, such as basketball and soccer/futsal.

European Association for Endoscopic Surgery (EAES) consensus on Indocyanine Green (ICG) fluorescence-guided surgery

BACKGROUND

In recent years, the use of Indocyanine Green (ICG) fluorescence-guided surgery during open and laparoscopic procedures has exponentially expanded across various clinical settings. The European Association of Endoscopic Surgery (EAES) initiated a consensus development conference on this topic with the aim of creating evidence-based statements and recommendations for the surgical community.

METHODS

An expert panel of surgeons has been selected and invited to participate to this project. Systematic reviews of the PubMed, Embase and Cochrane libraries were performed to identify evidence on potential benefits of ICG fluorescence-guided surgery on clinical practice and patient outcomes. Statements and recommendations were prepared and unanimously agreed by the panel; they were then submitted to all EAES members through a two-rounds online survey and results presented at the EAES annual congress, Barcelona, November 2021.

RESULTS

A total of 18,273 abstracts were screened with 117 articles included. 22 statements and 16 recommendations were generated and approved. In some areas, such as the use of ICG fluorescence-guided surgery during laparoscopic cholecystectomy, the perfusion assessment in colorectal surgery and the search for the sentinel lymph nodes in gynaecological malignancies, the large number of evidences in literature has allowed us to strongly recommend the use of ICG for a better anatomical definition and a reduction in post-operative complications.

CONCLUSIONS

Overall, from the systematic literature review performed by the experts panel and the survey extended to all EAES members, ICG fluorescence-guided surgery could be considered a safe and effective technology. Future robust clinical research is required to specifically validate multiple organ-specific applications and the potential benefits of this technique on clinical outcomes.

Diagnostic accuracy of a predictive scoring tool for patients who are eligible for home discharge from a palliative care unit

BACKGROUND

Staying at a preferred place, principally at home, is of great value for dying patients, and palliative care units (PCUs) have an important role in providing adequate support so that patients can be discharged and go home. We attempted to create and validate a scoring tool to predict whether a cancer patient admitted to a PCU will be discharged home.

METHODS

All 369 cancer patients admitted to the PCU of a 533-bed general hospital in Japan from October 2016 to October 2019 were enrolled. As outcomes, we recorded whether patients were discharged to home, died in hospitals, or were discharged to other hospitals. Attending physicians recorded 22 potential scale items at admission, including (I) demographic variables, (II) patient general conditions, (III) vital signs, (IV) medications, and (V) patient symptoms. Training-testing procedure to develop a screening score was performed.

RESULTS

Among 369 cancer patients admitted to the PCU, we excluded 10 cases for whom a death location could not be identified. Among the remaining 359 patients, 180 were analyzed in the development phase and 179 in the validation phase. Multivariate logistic regression analysis identified five items as independent factors associated with discharge to home, and a prediction equation was created using the regression coefficients: sex (female, 4 points), calorie intake (520 kcal or more, 19 points), availability of daytime caregivers (11 points), family's preferred place of care (home, 139 points), and symptoms that resulted in hospitalization (not fatigue, 7 points). Using a cutoff point of 155, the area under the curve (AUC) value was 0.949 with 95% confidence intervals of 0.918 to 0.981. In the validation sample, the sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), and error rate were 75.3%, 86.3%, 82.2%, 80.6%, and 18.4%, respectively.

CONCLUSIONS

Whether a patient admitted to a PCU can discharge to home could be predicted using the simple clinical tool. Further validation and outcome studies are warranted.

Rhythmic activation of excitatory neurons in the mouse frontal cortex improves the prefrontal cortex-mediated cognitive function

The prefrontal cortex (PFC) plays essential roles in cognitive processes. Previous studies have suggested the layer and the cell type-specific activation for cognitive enhancement. However, the mechanism by which a temporal pattern of activation affects cognitive function remains to be elucidated. Here, we investigated whether the specific activation of excitatory neurons in the superficial layers mainly in the PFC according to a rhythmic or nonrhythmic pattern could modulate the cognitive functions of normal mice. We used a C128S mutant of channelrhodopsin 2, a step function opsin, and administered two light illumination patterns: (i) alternating pulses of blue and yellow light for rhythmic activation or (ii) pulsed blue light only for nonrhythmic activation. Behavioral analyses were performed to compare the behavioral consequences of these two neural activation patterns. The alternating blue and yellow light pulses, but not the pulsed blue light only, significantly improved spatial working memory and social recognition without affecting motor activity or the anxiety level. These results suggest that the rhythmic, but not the nonrhythmic, activation could enhance cognitive functions. This study indicates that not only the population of neurons that are activated but also the pattern of activation plays a crucial role in the cognitive enhancement.

Erratic and blood vessel-guided migration of astrocyte progenitors in the cerebral cortex

Astrocytes are one of the most abundant cell types in the mammalian brain. They play essential roles in synapse formation, maturation, and elimination. However, how astrocytes migrate into the gray matter to accomplish these processes is poorly understood. Here, we show that, by combinational analyses of in vitro and in vivo time-lapse observations and lineage traces, astrocyte progenitors move rapidly and irregularly within the developing cortex, which we call erratic migration. Astrocyte progenitors also adopt blood vessel-guided migration. These highly motile progenitors are generated in the restricted prenatal stages and differentiate into protoplasmic astrocytes in the gray matter, whereas postnatally generated progenitors do not move extensively and differentiate into fibrous astrocytes in the white matter. We found Cxcr4/7, and integrin β1 regulate the blood vessel-guided migration, and their functional blocking disrupts their positioning. This study provides insight into astrocyte development and may contribute to understanding the pathogenesis caused by their defects.

Development of intensiometric indicators for visualizing N-cadherin interaction across cells

N-cadherin (NCad) is a classical cadherin that mediates cell–cell interactions in a Ca²⁺-dependent manner. NCad participates in various biological processes, from ontogenesis to higher brain functions, though the visualization of NCad interactions in living cells remains limited. Here, we present intensiometric NCad interaction indicators, named INCIDERs, that utilize dimerization-dependent fluorescent proteins. INCIDERs successfully visualize reversible NCad interactions across cells. Compared to FRET-based indicators, INCIDERs have a ~70-fold higher signal contrast, enabling clear identification of NCad interactions. In primary neuronal cells, NCad interactions are visualized between closely apposed processes. Furthermore, visualization of NCad interaction at cell adhesion sites in dense cell populations is achieved by two-photon microscopy. INCIDERs are useful tools in the spatiotemporal investigation of NCad interactions across cells; future research should evaluate the potential of INCIDERs in mapping complex three-dimensional architectures in multi-cellular systems.

Intensiometric N-cadherin (NCad) interaction indicators, named INCIDERs, visualize reversible NCad-mediated cell-cell interactions.

Characteristics of False-Positive Alarms in the BacT/Alert 3D System

The BacT/Alert system has been used for detecting the presence of bacteria in various clinical settings as well as in blood services, but it is associated with a relatively high incidence of false-positive results. We analyzed the results of our quality control sterility testing of blood products by BacT/Alert 3D to understand the mechanism of false-positive results. Anaerobic and aerobic bottles were inoculated with 10 mL of samples and cultured in BacT/Alert 3D for 10 days. Positive-reaction cases were classified as true positive if any bacterium was identified or false positive if the identification test had a negative result. The detection algorithm and the bottle graph pattern of the positive reaction cases were investigated. Among the 43,374 samples, 25 true positives (0.06%) and 29 false positives (0.07%) were observed. Although the detection algorithm of all true positives and 25 of 29 false positives was accelerating production of CO2, a steep rise in the bottle graph was observed only in the true positives, and it was not observed in either of the false positives. Four of 29 false positives were dependent on high baseline scatter reflections. Furthermore, evaluating the bottle graph pattern of Streptococcus pneumoniae, a bacterium known to autolyze, we confirmed that no viable bacterium was detected even if a steep rise was observed. In conclusion, the bottle graph pattern of positive reactions allows the differentiation between true positives and false positives. In case of a steep rise without bacterium detection, the bacterium might have autolyzed. Moreover, positive reactions with high baseline scatter reflections, despite immediate loading of bottles after sampling, are potentially false positive. IMPORTANCE In clinical settings, false-positive results are treated as positive until bacterial identification. It may result in the discarding of blood products in blood centers or affect clinical decisions in hospitals or testing facilities. Moreover, the management of these samples is usually time- and labor-consuming. The results of our study may help clinicians and laboratory staff in making a more precise evaluation of positive reactions in BacT/Alert.

TPT1 Supports Proliferation of Neural Stem/Progenitor Cells and Brain Tumor Initiating Cells Regulated by Macrophage Migration Inhibitory Factor (MIF)

One of the key areas in stem cell research is the identification of factors capable of promoting the expansion of Neural Stem Cell/Progenitor Cells (NSPCs) and understanding their molecular mechanisms for future use in clinical settings. We previously identified Macrophage Migration Inhibitory Factor (MIF) as a novel factor that can support the proliferation and/or survival of NSPCs based on in vitro functional cloning strategy and revealed that MIF can support the proliferation of human brain tumor-initiating cells (BTICs). However, the detailed downstream signaling for the functions has largely remained unknown. Thus, in the present study, we newly identified translationally-controlled tumor protein-1 (TPT1), which is expressed in the ventricular zone of mouse embryonic brain, as a downstream target of MIF signaling in mouse and human NSPCs and human BTICs. Using gene manipulation (over or downregulation of TPT1) techniques including CRISPR/Cas9-mediated heterozygous gene disruption showed that TPT1 contributed to the regulation of cell proliferation/survival in mouse NSPCs, human embryonic stem cell (hESC) derived-NSPCs, human-induced pluripotent stem cells (hiPSCs) derived-NSPCs and BTICs. Furthermore, gene silencing of TPT1 caused defects in neuronal differentiation in the NSPCs in vitro. We also identified the MIF-CHD7-TPT1-SMO signaling axis in regulating hESC-NSPCs and BTICs proliferation. Intriguingly, TPT1suppressed the miR-338 gene, which targets SMO in hESC-NSPCs and BTICs. Finally, mice with implanted BTICs infected with lentivirus-TPT1 shRNA showed a longer overall survival than control. These results also open up new avenues for the development of glioma therapies based on the TPT1 signaling pathway.

Jaw-Clenching Intensity Effects on Masseter Oxygen Dynamics and Fatigue: A NIRS Oximetry Study

The purpose of this study was to clarify the effects of jaw-clenching intensity on masseter muscle oxygen dynamics during clenching and recovery and masseter muscle fatigue using the spatially resolved method of near-infrared spectroscopy. Pulse rate, mean power frequency from electromyography in the masseter and visual analogue scale for masseter fatigue were also examined as related items. The 25% and 50% maximum voluntary contractions were determined using electromyography before the experiment and used as visual feedback on the screen. Twenty-three healthy adult male subjects volunteered for this study. Clenching decreased oxygen and oxygenated haemoglobin, and increased deoxygenated haemoglobin in the masseter muscle. The higher the intensity of clenching, the more prominent the effect. The oxygen dynamics tended to return to normal after clenching, but the change was slower with higher clenching intensity. Pulse rate increased with clenching, and the increment was more prominent with higher clenching intensity. Clenching caused a shift of mean power frequency to a lower range, an increase in subjective fatigue, an early appearance of a breakpoint appearance time and a prolongation of a 1/2 recovery time. All of these effects were more evident with increasing clenching intensity. In conclusion, clenching intensity influenced the oxygen dynamics of the masseter muscle and fatigue state during clenching and recovery. The higher the intensity, the greater the impact.

Process Evaluation of the Regional Referral Clinical Pathway for Home-Based Palliative Care and Outreach Program: A Questionnaire Survey of the Medical Staff and Bereaved Families

Background: The purpose of this study was to clarify how the Regional Referral Clinical Pathway for Home-based Palliative Care (RRCP-HPC) and an outreach program by a palliative care team (PCT) lead to an improvement in the outcome. Design and Methods: We conducted questionnaire surveys using the mailing method involving the regional medical staff involved in cancer patients introduced to the PCT of a single hospital, as well as bereaved families. The questionnaire was prepared through interviews with the medical staff and bereaved families. Subsequently, factor analysis was performed to identify factor structures and calculate the correlation coefficient with each outcome. Results: For the questionnaire survey involving the medical staff, responses were collected from 119 regional medical institutions and 84 regional medical staff. The response rate per institution was 51.3%. Similarly, for the questionnaire survey involving bereaved families, the response rate was 42.4%. For the survey involving the medical staff, 6 factors, such as “improved awareness of an interdisciplinary team,” were extracted. For the survey involving the bereaved families, 4 factors, such as “improvement of communications between patients and healthcare professionals,” were extracted. There were significant (≥moderate) correlations between these factors and all outcomes. Conclusion: In this study, we clarified the process of achieving palliative care until death at home without difficulties using the outreach program and RRCP-HPC. The results suggest the importance of improving communications. The outreach program and RRCP-HPC may have contributed to palliative care at home without difficulties through an improvement in communications.

High spatial-density, cladding-pumped 6-mode 7-core fiber amplifier for C-band operation

We present a C-band 6-mode 7-core fiber amplifier in an all-fiberized cladding-pumped configuration for space division multiplexed transmission supporting a record 42 spatial channels. With optimized fiber components (e.g. passively cooled pump laser diode, pump coupler, pump stripper), high power multimode pump light is coupled to the active fiber without any noticeable thermal degradation and an average gain of 18 dB and noise figure of 5.4 dB are obtained with an average differential modal gain of 3.4 dB.

40 Years Anniversary of Cardiac 123I-mIBG Imaging: State of the Heart

Purpose of Review

This narrative review reflects on the body of evidence on cardiac 123I-mIBG imaging that has accumulated since the introduction in the late 1970s and focusses on to what extent cardiac 123I-mIBG imaging has fulfilled its potential in cardiology especially.

Recent Findings

In contrast to the linear relationship between 123I-mIBG-derived parameters and overall prognosis in heart failure, there seems a “bell-shape” curve for 123I-mIBG-derived parameters and arrhythmic events. In addition, there is a potential clinical role for cardiac 123I-mIBG in optimizing patient selection for expensive devices (i.e., ICD and CRT). This needs of course to be established in future trials.

Summary

Cardiac 123I-mIBG imaging is, despite the numerous of studies, sometimes mistakenly seen as a nice to have technique rather than a must have imaging modality. Although cardiac 123I-mIBG imaging has grown and matured over the years, its full clinical potential has still not been tested to the maximum.

The relation between cardiac 123I-mIBG scintigraphy and functional response 1 year after CRT implantation

Aims 

Cardiac resynchronization therapy (CRT) is a disease-modifying therapy in patients with chronic heart failure (CHF). Current guidelines ascribe CRT eligibility on three parameters only: left ventricular ejection fraction (LVEF), QRS duration, and New York Heart Association (NYHA) functional class. However, one-third of CHF patients does not benefit from CRT. This study evaluated whether ¹²³I-meta-iodobenzylguanidine (¹²³I-mIBG) assessed cardiac sympathetic activity could optimize CRT patient selection.

Methods and results 

A total of 78 stable CHF subjects (age 66.8 ± 9.6 years, 73% male, LVEF 25.2 ± 6.7%, QRS duration 153 ± 23 ms, NYHA 2.2 ± 0.7) referred for CRT implantation were enrolled. Subjects underwent ¹²³I-mIBG scintigraphy prior to implantation. Early and late heart-to-mediastinum (H/M) ratio and ¹²³I-mIBG washout were calculated. CRT response was defined as either an increase of LVEF to >35%, any improvement in LVEF of >10%, QRS shortening to <150 ms, or improvement in NYHA class of >1 class. In 33 patients LVEF increased to >35%, QRS decreased <150 ms in 36 patients, and NYHA class decreased in 33 patients. Late H/M ratio and hypertension were independent predictors of LVEF improvement to >35% (P = 0.0014 and P = 0.0149, respectively). In addition, early H/M ratio, LVEF, and absence of diabetes mellitus (DM) were independent predictors for LVEF improvement by >10%. No independent predictors were found for QRS shortening to <150 ms or improvement in NYHA class.

Conclusion 

Early and late H/M ratio were independent predictors of CRT response when improvement of LVEF was used as measure of response. Therefore, cardiac ¹²³I-mIBG scintigraphy may be used as a tool to optimize selection of subjects that might benefit from CRT.

Prognostic value of myocardial MIBG scintigraphy in acute ischemic stroke

Funding Acknowledgements

Type of funding sources: None.

Background Autonomic dysfunction is a common complication of acute ischemic stroke and has been associated with poor functional outcome and increased mortality. We investigated the potential relation between the myocardial washout rate (WOR) of 123I-meta-iodobenzylguanidine (123I-mIBG), as a measure of cardiac sympathetic activity, and functional outcome in acute ischemic stroke. 

Methods 38 patients with ischemic stroke (11 females, 72 years old [61-81)), underwent myocardial 123I-mIBG scintigraphy within the first week after stroke onset. Early (10 minutes post-injection (pi)) and late (4 hours pi) planar scans of the thoracic region were made. Regions of interest (ROI) were drawn over the mediastinum and the heart, and heart-to-mediastinum ratio (HMR) was calculated. Myocardial WOR was calculated as follows: (ROI heart early – ROI heart late)/ (ROI heart early) x 100%. Counts were corrected for background and counts in ROI heart late were corrected for decay. Patients were divided in 2 groups: those with a good functional outcome, defined as modified Rankin Scale (mRS) ≤ 2 at 3 months after stroke (i.e., patient is functionally independent), and those with a poor functional outcome, defined as a mRS &gt; 2. 

Results Median WOR was 27,4 % (IQR 10,4-43,6). In univariate analysis, poor functional outcome after stroke was associated with age, stroke severity on admission (measured by the National Institutes of Health Stroke Scale (NIHSS)), beta-blocker use before and during hospitalization, WOR and late HMR. In subsequent multivariate analysis WOR (OR 1.087; 95% CI 1.003-1.177, p = 0.042) was an independent predictor of poor stroke outcome even after adjustment for age and NIHSS.

Conclusions In patients with acute ischemic stroke, myocardial washout of 123I-mIBG predicts stroke outcome, even after adjustment for age and stroke severity on admission.

Radiomics analysis of myocardial perfusion SPECT images in patients with cardiomyopathy and heart failure

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): JSPS KAKENHI Grants

Background

Although myocardial perfusion heterogeneity due to focally damaged cardiomyocytes is observed in single−photon emission computed tomography (SPECT) imaging, a current perfusion defect scoring system does not allow us to provide sufficient diagnostic information for heterogeneity.

Purpose

The aim of this study was to perform radiomics analysis of myocardial perfusion SPECT (MPS) images to investigate the potential to detect myocardial perfusion heterogeneity.

Methods

Patients with hypertrophic cardiomyopathy (n = 3), heart failure (n = 9), and with a low likelihood of coronary artery disease (n =15) (Figure 1), who underwent a rest 99mTc-MIBI myocardial perfusion SPECT, were assessed using a LIFEx software. Four shape−based features, 6 histogram−based features, and 32 textural features were computed. The relevant features for the classification of the patients were selected using the Boruta algorithm, and hierarchical clustering of the selected features using the Spearman correlation coefficient was also performed for the feature reduction. The receiver operating characteristics (ROC) analysis was performed by the support vector machine to calculate the area under the ROC curve (AUC) for the selected features.

Results

Of 40 features, 17 were selected by the classification analysis, and these features were classified into 7 classes by the correlation analysis (Figure 2). The ROC AUCs for 7 features extracted from each class were 0.99, 0.97, 0.96, 0.92, 0.90, 0.86, and 0.83 for the contrast of NDGLDM, the entropy of histogram, ZLNU of GLZLM, the energy of GLCM, the energy of histogram, SZLGE of GLZLM, and the correlation of GLCM, respectively, as compared to 0.39 for a summed rest score.

Conclusions

Radiomics analysis successfully determined the myocardial perfusion heterogeneity in patients with cardiomyopathy and heart failure. It might be promising for the evaluation of myocardial damages that cannot be analyzed by the conventional scoring method.

Creation of mortality risk calculator using a I-123 mIBG-based machine learning model: differential prediction of arrhythmic death and heart-failure death

Funding Acknowledgements

Type of funding sources: None.

Background

Although I-123 meta-iodobenzylguanidine (mIBG) has been applied to patients with chronic heart failure (CHF), a diagnostic tool for differential prediction of fatal arrhythmic events (ArE) and heart-failure death (HFD) has been pursued. 

Purpose

The aim of this study was to create a calculator of mortality risk for differentiating mode of cardiac death using a machine learning (ML) method, and to test the accuracy in a new cohort of patients with CHF.

Methods

A total of 529 patients with CHF was used as the training database for ML. The ArE group consisted of patients with arrhythmic death, sudden cardiac death and appropriate therapy by implantable cardioverter defibrillator. A heart-to-mediastinum ratio (H/M) standardized to the medium-energy collimator condition was calculated with a planar anterior mIBG scintigram. The best classifier models for predicting HFD and ArE were determined by four-fold cross validation. Input variables included age, sex, New York Heart Association (NYHA) functional class, left ventricular ejection fraction, ischemic etiology, mIBG H/M and washout rate, and b-type natriuretic peptide (BNP) or NT Pro BNP, estimated glomerular filtration rate, hemoglobin, and complications such as diabetes and hypertension. After creating the ML-based model, the constructed classifier functions for ArE, HFD, and survival were exported for subsequent use. A new cohort of patients (n = 312, age 67 ± 13 years, 2015 or later) was used to test the ML-based model.

Results

The training database included 141 events (27%) with ArE (7%) and HFD (20%). Receiver-operating characteristic analysis by four-fold validation showed area under the curve value of 0.90 for HFD and 0.73 for ArE. Among various ML methods, the logistic regression method demonstrated the most stable calculation of the probability of ArE followed by random forest and gradient boosted tree methods. Therefore, the logistic-regression method was used for calculating both HFD and ArE probabilities. In the test cohort, patients with a high HFD probability &gt;8% resulted in 6.3-fold higher HFD than those with low probability (≤ 8%). Patients with high ArE probability &gt;8% showed 2.5-fold higher ArE than those with low probability (≤ 8%).

Conclusion

The ML-based mortality risk calculator could be used for stratifying patients at high and low risks, which might be useful for estimating appropriate treatment strategy.

Alendronate/dexamethasone combination therapy worsens soft and hard tissue wound healing around implants in rat maxillae

Dental implant treatment in patients prescribed medications is associated with bisphosphonate-related osteonecrosis of the jaw (BRONJ) around the implants. However, there is no scientific information on how bisphosphonate and/or steroid therapies affect wound healing around implants after implant placement. The aim of this study was to histopathologically and immunopathologically investigate the effects of bisphosphonate and/or steroid therapy on the early stages of soft and hard tissue wound healing around implants in rat maxillae. Eight-week-old female Wistar rats were used. Alendronate (ALN) monotherapy, dexamethasone (DEX) monotherapy, and ALN/DEX combination therapy were started 4 weeks after tooth extraction of right maxillary first molars. Saline was used as a control (n = 14/group). Implant placement was carried out after grossly and manually confirming no open wounds at 16 weeks post-extraction. Euthanasia was performed at 18 weeks post-extraction. Microcomputed tomography, histological stains and immunostaining to detect blood vessels and macrophages were performed to quantitatively analyze wound healing around implants. ALN/DEX combination therapy significantly increased necrotic bone with more empty lacunae and polymorphonuclear cell infiltration with open wounds when compared with all other therapy groups. Necrotic bone was broadly distributed from the crestal bone to the lower area near the apex of the implants in the ALN/DEX group. Interestingly, both ALN/DEX combination therapy and DEX monotherapy significantly increased the number of CD68⁺NG2^- macrophages, whereas only ALN/DEX combination therapy, not DEX monotherapy, significantly shifted the M1/M2 ratio to M1 by significant increases in M1 macrophages and unchanged M2 macrophages in the connective tissue around implants. Within the limitations of this study, these findings may contribute to understanding the early stages of the histopathology and immunopathology of BRONJ-like lesions around dental implants. Continuous accumulation of M1 macrophages without alteration of M2 macrophages may be associated with developing BRONJ around implants.

Combined impact of HLA-allele matching and the CD34-positive cell dose on optimal unit selection for single-unit cord blood transplantation in adults

The combined effects of HLA-allele matching at six-loci (HLA-A, -B, -C, -DRB1, -DQB1, and -DPB1) and CD34⁺ cell dose on clinical outcomes were analyzed in 1,226 adult cases with single-unit unrelated cord blood transplantation. In the six-loci analysis, low HLA-allele matches did not significantly increase the overall mortality compared to higher matches, whereas in the five-loci analysis excluding HLA-DPB1, they caused a higher overall mortality (HR 1.42, p = .002), possibly due to the graft-versus-leukemia effect of HLA-DPB1 mismatches. A lower CD34⁺ cell dose (<.50 × 10⁵/kg) resulted in higher mortality and lower engraftment; these inferior outcomes were offset by high HLA-allele matches (7-10/10 match), while the inferior outcomes of low HLA-allele matches were improved by increasing the CD34⁺ cell dose. Consideration of the combined effects of the CD34⁺ cell dose and HLA matching may expand the options for transplantable units when HLA matching or the CD34⁺ cell dose is inadequate.

Comprehensive characterization of migration profiles of murine cerebral cortical neurons during development using FlashTag labeling

In the mammalian cerebral neocortex, different regions have different cytoarchitecture, neuronal birthdates, and functions. In most regions, neuronal migratory profiles are speculated similar based on observations using thymidine analogs. Few reports have investigated regional migratory differences from mitosis at the ventricular surface. In this study, we applied FlashTag technology, in which dyes are injected intraventricularly, to describe migratory profiles. We revealed a mediolateral regional difference in the migratory profiles of neurons that is dependent on developmental stage; for example, neurons labeled at embryonic day 12.5–15.5 reached their destination earlier dorsomedially than dorsolaterally, even where there were underlying ventricular surfaces, reflecting sojourning below the subplate. This difference was hardly recapitulated by thymidine analogs, which visualize neurogenic gradients, suggesting a biological significance different from the neurogenic gradient. These observations advance our understanding of cortical development and the power of FlashTag in studying migration and are thus resources for future neurodevelopmental studies.

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FlashTag visualized mediolateral regional differences of cortical migratory profiles

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Mediolateral differences were observed when neurons were labeled at E12.5–15.5

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Late-born neurons transiently sojourned below the dorsolateral subplate (SP) cells

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The difference was unclear in reeler cortex, where SP cells position superficially

Gene expression analysis of fresh extraction wounds prior to onset of bisphosphonate-related osteonecrosis of the jaw-like lesions in mice: A preliminary animal study

PURPOSE

The aim of the present study was to investigate the effects of chemotherapeutic/bisphosphonate combination therapy with tooth extraction on gene expression patterns of fresh extraction wounds during initial stages prior to their diagnosis as bisphosphonate-related osteonecrosis of the jaw (BRONJ)-like lesions in mice.

METHODS

Female C57BL/6J mice were used. To create a high-prevalence BRONJ mouse model, combination therapy with the chemotherapy drug cyclophosphamide (CY) and zoledronic acid (ZA) was performed (CY/ZA). Both maxillary first molars were extracted 3 weeks after drug therapy. Saline was used as the control (VC). Soft tissues near the fresh extraction wounds were dissected at 72 h postextraction to investigate the gene expression patterns. Maxillae and long bones at 2 and 4 weeks postextraction were also analyzed.

RESULTS

CY/ZA significantly increased the relative expression levels of IL-6 and decreased those of IL-10 and IGF-1 when compared with those in VC. Moreover, CY/ZA significantly reduced the relative expression levels of CCR-7, cxcl12, cxcr4, and CD105 when compared with those in VC, whereas the level of F4/80 was significantly increased by CY/ZA. Furthermore, CY/ZA significantly decreased the relative expression levels of VEGFA, VEGFB, and VEGFC at 72 h postextraction compared with those in VC.

CONCLUSIONS

Considering that the present study lacked adequate in vitro models, CY/ZA markedly changed the gene expression patterns associated with wound healing from the initial stages prior to onset of BRONJ-like lesions, which may help us to understand the pathophysiology of BRONJ in humans.

Lead-free MCP to improve coincidence time resolution and reduce MCP direct interactions

Achieving direct imaging of the annihilation position of a positron on an event-by-event basis using an ultrafast detector would have a great impact on the field of nuclear medicine. Cherenkov emission is the most attractive physical phenomenon for realizing such an ultrafast timing performance. Moreover, a microchannel-plate photomultiplier tube (MCP-PMT) is one of the most promising photodetectors for fully exploiting the fast timing properties of Cherenkov emission owing to its excellent single photon time resolution of 25 ps full width at half maximum (FWHM). However, as the MCP structure generally contains a lead compound, the gamma rays frequently and directly interact with the MCP, resulting in the degradation of its timing performance and generation of undesirable side peaks in its coincidence timing histogram. To overcome this problem, we have developed a new MCP-PMT based on an MCP consisting of borosilicate glass, thus drastically reducing the probability of the photoelectric effect occurring in the MCP. To evaluate its insensitivity to gamma rays and its timing performance, a coincidence experiment was performed and showed that the probability of direct interactions was reduced by a factor of 3.4. Moreover, a coincidence time resolution of 35.4 ± 0.4 ps FWHM, which is equivalent to a position resolution of 5.31 mm, was obtained without any pulse height/area cut, improving to 28.7 ± 3.0 ps when selecting on the highest amplitude events by careful optimization of the voltage divider circuit of the new MCP-PMT. The timing performance of this new MCP-PMT presents an important step toward making direct imaging possible.

REACTOR PHYSICS EXPERIMENT IN A GRAPHITE-MODERATION SYSTEM FOR HTGR

The Japan Atomic Energy Agency (JAEA) started the Research and Development (R&D) to improve nuclear prediction techniques for High Temperature Gas-cooled Reactors (HTGRs). The objectives are to introduce a generalized bias factor method to avoid full mock-up experiment for the first commercial HTGR and to introduce reactor noise analysis to High Temperature Engineering Test Reactor (HTTR) experiment to observe sub-criticality. To achieve the objectives, the reactor core of graphite-moderation system named B7/4”G2/8”p8EUNU+3/8”p38EU(1) was newly composed in the B-rack of Kyoto University Critical Assembly (KUCA). The core is composed of the fuel assembly, driver fuel assembly, graphite reflector, and polyethylene reflector. The fuel assembly is composed of enriched uranium plate, natural uranium plate and graphite plates to realize the average fuel enrichment of HTTR and it’s spectrum. However, driver fuel assembly is necessary to achieve the criticality with the small-sized core. The core plays a role of the reference core of the bias factor method, and the reactor noise was measured to develop the noise analysis scheme. In this study, the overview of the criticality experiments is reported. The reactor configuration with graphite moderation system is rare case in the KUCA experiments, and this experiment is expected to contribute not only for an HTGR development but also for other types of a reactor in the graphite moderation system such as a molten salt reactor development.

Dynamic polarization shifting from M1 to M2 macrophages in reduced osteonecrosis of the jaw-like lesions by cessation of anti-RANKL antibody in mice

Denosumab-related osteonecrosis of the jaw (DRONJ), which mainly occurs in cancer patients receiving anti-receptor activator NF-kappaB ligand (RANKL) antibody, reduces oral health-related quality of life. However, the exact mechanisms of and definitive treatment strategies for DRONJ remain unknown. We hypothesized that cessation of denosumab heals and/or ameliorates DRONJ, since it is a protein-based antibody agent, although stopping denosumab should be avoided in clinical situations. Therefore, the aims of this study were: 1) to create a healing and/or amelioration murine model of DRONJ-like lesions induced by chemotherapy/anti-RANKL antibody (mAb) combination therapy and tooth extraction; and 2) to investigate histopathology and immunopathology in the extraction sockets by comparing the murine model of DRONJ-like lesions with the amelioration/healing model of DRONJ-like lesions. Eight-week-old, female C57B/6J mice received chemotherapeutic drug (cyclophosphamide: CY) and mAb combination therapy (CY/mAb) with tooth extraction. Open wounds were sustained in CY/mAb-treated mice at 2 and 4 weeks post-extraction. Impaired socket healing was diagnosed as CY/mAb-related ONJ-like lesions at 3 weeks post-extraction in this study. Next, mAb was discontinued for 2 and 4 weeks after diagnosis of CY/mAb-related ONJ-like lesions. mAb cessation for 2 weeks induced partial osseous wound healing and significantly improved soft tissue wound healing of the extraction sockets. Anti-angiogenesis and normal lymphangiogenesis with CY/mAb combination therapy was not changed by mAb discontinuation. However, mAb cessation for 2 weeks significantly increased the number of CD38⁺F4/80⁺ M1 and CD163⁺F4/80⁺ M2 macrophages, which significantly increased the M2/M1 ratio in the connective tissue of extraction sockets. No direct effects of mAb on macrophages were noted both in vivo and in vitro. Therefore, the developed healing and/or amelioration murine model of CY/mAb-related ONJ-like lesions is a useful tool to investigate the histopathology and immunopathology of DRONJ in humans. Dynamic polarization shifting from M1 to M2 macrophages induced by mAb cessation may play an important role in wound healing, rather than angiogenesis and lymphangiogenesis, in DRONJ.

Ventricular tachycardia in cardiac sarcoidosis -prognosis, characterization of ventricular substrates and outcomes of treatment-

Background

The prognosis, the underlying substrate and clinical outcomes of treatment are unclear in patients with cardiac sarcoidosis (CS)-related ventricular tachycardia (VT).

Objective

This study investigated the prognosis and the relationship between electroanatomical mapping (EAM) and imaging findings in patients with CS-related VT.

Methods

A total of 203 CS patients (Age 68.1±11.6 years, 87 males) were enrolled at two tertiary care medical centers between 2000 and 2018. All met the 2016 Japanese Circulation Society guidelines for diagnosis of CS. They were followed for a composite of major adverse cardiac events (MACE) including cardiac death, heart transplantation, unscheduled hospitalization for heart failure, and life-threatening ventricular arrhythmias. Distribution of late gadolinium enhancement (LGE) on cardiac MRI (CMR) and/or an abnormal myocardial 18F-fluorodeoxyglucose (FDG) uptake on positron emission tomography at diagnosis were examined. The relationship between EAM and the image findings were also analyzed in patients with radiofrequency ablation (RFA) for VT.

Results

During a median follow-up of 53 months, 87 of the 203 patients (43%) experienced a MACE. Baseline factors associated with MACE were presence of sustained VT (HR, 2.43, 95% CI 1.54–3.85, P&lt;0.001), left ventricular ejection fraction below 50% (HR, 1.95 95% CI 1.07–3.56, P=0.029), and abnormal myocardial FDG uptake (HR, 2.42 95% CI 1.04–5.61, P=0.039). Overall, 69 of the 203 patients (34%) experienced sustained VT. Abnormal myocardial FDG uptake was significantly more prevalent in patients with VT than in those without (92.7% vs. 78.5%, P=0.02). A total of 25 patients (9.9%) required RFA for CS-related VT (Age 64.0±8.7 years, 12 males, 1.32±0.56 RFAs per patient). Abnormal electrocardiograms (EGM) were observed in 22 of the 25 patients (88%). LGE was more frequent than abnormal FDG uptake in areas with an abnormal EGM (77% vs. 41%; P=0.002). Over a mean follow-up period of 67-months, 13 of the 25 patients with RFA (52%) remained free of VT episodes (Figure). VT recurred in nine of the 12 patients with RFA and in 17 of the 47 patients without RFA, but was suppressed by intensive pharmacologic therapy such as the combined use of amiodarone and sotalol. In patients with CS-related VT, survival without experiencing a MACE did not differ in participants with or without RFA.

Conclusions

In our 203 CS patients, sustained VT and abnormal FDG uptake were associated with worse cardiac outcomes. The prevalence of abnormal FDG uptake was significantly higher in patients with CS-related VT, LGE on CMR was more frequent within localized areas of an abnormal EGM, suggesting that both scar itself and the associated inflammation were involved in the pathogenesis of CS-related VT. Successful RFA of CS-related VT is still challenging, and recurrence is common. Preprocedural CMR can be useful in detecting abnormal EGMs that are potential targets for substrate ablation.

Funding Acknowledgement

Type of funding source: None