Machine learning analysis of pathological images to predict 1-year progression-free survival of immunotherapy in patients with small-cell lung cancer

BACKGROUND

In small-cell lung cancer (SCLC), the tumor immune microenvironment (TIME) could be a promising biomarker for immunotherapy, but objectively evaluating TIME remains challenging. Hence, we aimed to develop a predictive biomarker of immunotherapy efficacy through a machine learning analysis of the TIME.

METHODS

We conducted a biomarker analysis in a prospective study of patients with extensive-stage SCLC who received chemoimmunotherapy as the first-line treatment. We trained a model to predict 1-year progression-free survival (PFS) using pathological images (H&E, programmed cell death-ligand 1 (PD-L1), and double immunohistochemical assay (cluster of differentiation 8 (CD8) and forkhead box P3 (FoxP3)) and patient information. The primary outcome was the mean area under the curve (AUC) of machine learning models in predicting the 1-year PFS.

RESULTS

We analyzed 100,544 patches of pathological images from 78 patients. The mean AUC values of patient information, pathological image, and combined models were 0.789 (range 0.571-0.982), 0.782 (range 0.750-0.911), and 0.868 (range 0.786-0.929), respectively. The PFS was longer in the high efficacy group than in the low efficacy group in all three models (patient information model, HR 0.468, 95% CI 0.287 to 0.762; pathological image model, HR 0.334, 95% CI 0.117 to 0.628; combined model, HR 0.353, 95% CI 0.195 to 0.637). The machine learning analysis of the TIME had better accuracy than the human count evaluations (AUC of human count, CD8-positive lymphocyte: 0.681, FoxP3-positive lymphocytes: 0.626, PD-L1 score: 0.567).

CONCLUSIONS

The spatial analysis of the TIME using machine learning predicted the immunotherapy efficacy in patients with SCLC, thus supporting its role as an immunotherapy biomarker.

The Role of Chorein Deficiency in Late Spermatogenesis

VPS13A, also known as chorein, whose loss of function causes chorea-acanthocytosis (ChAc), is characterized by Huntington's-disease-like neurodegeneration and neuropsychiatric symptoms in addition to acanthocytosis in red blood cells. We previously reported that ChAc-model mice with a loss of chorein function exhibited male infertility, with asthenozoospermia and mitochondrial dysmorphology in the spermatozoa. Here, we report a novel aspect of chorein dysfunction in male fertility, particularly its role in spermatogenesis and mitochondrial integrity. An increase in anti-malondialdehyde antibody immunoreaction within the testes, predominantly observed at the advanced stages of sperm formation in chorein-deficient mice, suggests oxidative stress as a contributing factor to mitochondrial dysfunction and impaired sperm maturation. The chorein immunoreactivity in spermatids of wild-type mice accentuates its significance in sperm development. ChAc-model mice exhibit mitochondrial ultrastructural abnormalities, specifically during the late stages of sperm maturation, suggesting a critical timeframe for chorein's action in spermiogenesis. We observed an increase in TOM20 protein levels, indicative of disrupted mitochondrial import mechanisms. The concurrent decrease in metabolic enzymes such as IDH3A, LDHC, PGK2, and ACAT1 suggests a complex chorein-mediated metabolic network that is essential for sperm vitality. Additionally, heightened separation of cytoplasmic droplets from sperm highlights the potential membrane instability in chorein-deficient spermatozoa. Metabolomic profiling further suggests a compensatory metabolic shift, with elevated glycolytic and TCA-cycle substrates. Our findings suggest that chorein is involved in anti-ferroptosis and the maturation of mitochondrial morphology in the late stages of spermatogenesis, and its deficiency leads to asthenozoospermia characterized by membrane instability, abnormal cytosolic glycolysis, abnormal mitochondrial function, and a disrupted TCA cycle. Further analyses are required to unravel the molecular mechanisms that directly link these findings and to elucidate the role of chorein in spermatogenesis as well as its broader implications.

Aging-Related Catatonia with Reversible Dopamine Transporter Dysfunction in Females with Depressive Symptoms: A Case Series

OBJECTIVES

The authors describe five depressive patients with initially decreased striatal accumulation of dopamine transporter (DAT) single-photon emission computed tomography (SPECT), which improved in parallel with clinical symptoms.

METHODS

Patients who exhibited decreased striatal accumulation and recovery of DATSPECT were identified among patients with the symptoms of depression. Their clinical and neuroimaging data were reviewed.

RESULTS

Five patients were identified. All patients were presenile or senile women who presented with catatonia subsequent to symptoms of depression that remitted with treatment. DAT-SPECT showed a decreased striatal accumulation in all patients, which increased after treatment. Two patients had met the diagnostic criteria of probable dementia with Lewy bodies (DLB), but no longer did so after their symptoms improved.

CONCLUSIONS

Reversible DAT dysfunction observed in this study suggests that reversible impairment of dopaminergic transmission in the striatum partly underlies catatonia. Careful consideration should be given to diagnosing DLB in patients with decreased DAT-SPECT accumulation, especially when catatonia is present.

Development of a novel artificial intelligence algorithm to detect pulmonary nodules on chest radiography

BACKGROUND

In this study, we aimed to develop a novel artificial intelligence (AI) algorithm to support pulmonary nodule detection, which will enable physicians to efficiently interpret chest radiographs for lung cancer diagnosis.

METHODS

We analyzed chest X-ray images obtained from a health examination center in Fukushima and the National Institutes of Health (NIH) Chest X-ray 14 dataset. We categorized these data into two types: type A included both Fukushima and NIH datasets, and type B included only the Fukushima dataset. We also demonstrated pulmonary nodules in the form of a heatmap display on each chest radiograph and calculated the positive probability score as an index value.

RESULTS

Our novel AI algorithms had a receiver operating characteristic (ROC) area under the curve (AUC) of 0.74, a sensitivity of 0.75, and a specificity of 0.60 for the type A dataset. For the type B dataset, the respective values were 0.79, 0.72, and 0.74. The algorithms in both the type A and B datasets were superior to the accuracy of radiologists and similar to previous studies.

CONCLUSIONS

The proprietary AI algorithms had a similar accuracy for interpreting chest radiographs when compared with previous studies and radiologists. Especially, we could train a high quality AI algorithm, even with our small type B data set. However, further studies are needed to improve and further validate the accuracy of our AI algorithm.

Clinical characteristics and outcomes of pheochromocytoma crisis: a literature review of 200 cases

PURPOSE

Pheochromocytoma crisis is a life-threatening endocrine emergency that requires prompt diagnosis and treatment. Because of its rarity, sudden onset, and lack of internationally uniform and validated diagnostic criteria, pheochromocytoma crisis remains to be fully clarified. Therefore, we aimed to describe the clinical characteristics and outcomes of pheochromocytoma crisis through a literature review.

METHODS

We performed a systematic literature search of PubMed/MEDLINE database, Igaku-Chuo-Zasshi (Japanese database), and Google Scholar to identify case reports of pheochromocytoma crisis published until February 5, 2021. Information was extracted and analyzed from the literature that reported adequate individual patient data of pheochromocytoma crisis in English or Japanese. Cases were also termed as pheochromocytoma multisystem crisis (PMC) if patients had signs of hyperthermia, multiple organ failure, encephalopathy, and labile blood pressure.

RESULTS

In the 200 cases of pheochromocytoma crisis identified from 187 articles, the mean patient age was 43.8 ± 15.5 years. The most common symptom was headache (39.5%). The heart was the most commonly damaged organ resulting from a complication of a pheochromocytoma crisis (99.0%), followed by the lungs (44.0%) and the kidney (21.5%). PMC accounted for 19.0% of all pheochromocytoma crisis cases. After excluding 12 cases with unknown survival statuses, the mortality rate was 13.8% (26/188 cases). Multivariable logistic regression analysis revealed that nausea and vomiting were significantly associated with a higher mortality rate.

CONCLUSION

Pheochromocytoma can present with different symptomatology, affecting different organ systems. Clinicians should be aware that patients with nausea or vomiting are at a higher risk of death because of pheochromocytoma crisis.

Predicting postpartum depression by evaluating temperament during pregnancy

AIM

The purpose of this study was to investigate premorbid temperaments to predict postpartum depression in pregnant women with no previous psychiatric history and to clarify the correlation between postpartum depression and the factors included in the Postpartum Depression Predictors Inventory-Revised (PDPI-R) and the Temperament Evaluation of Memphis, Pisa, Paris, and San Diego-Auto questionnaire (TEMPS-A)/Munich Personality Test (MPT).

METHODS

A total of 170 eligible pregnant women filled out both questionnaires, the first between the 8th and 23rd week of gestation, and the latter between the 34th and 38th week of gestation. Participants filled out The Edinburgh Postnatal Depression Scale (EPDS) one month postpartum to measure for postpartum depression symptoms. All participants delivered full-term healthy babies.

RESULTS

Seventeen (10%) women met the criteria for postpartum depression with a score of 9 or higher on the EDPS. The factors significantly related to developing postpartum depression were schizoid and melancholic temperament on the TEMPS-A/MPT and marital dissatisfaction on the PDPI-R. The total score on the PDPI-R was significantly correlated with depressive, cyclothymic, irritable, and anxious temperaments on the TEMPS-A/MPT. A lack of social support on the PDPI-R was significantly correlated with depressive, irritable, and anxious temperaments on the TEMPS-A/MPT.

CONCLUSION

The findings suggest that postpartum depression may be related to schizoid and melancholic temperaments and marital dissatisfaction. The hyperthymic temperament was identified as a significant predictor in preventing PPD. Careful observation during puerperium is recommended if a pregnant woman is likely to have these temperaments or psychological conditions. Temperament evaluation should be done during pregnancy as a form of postpartum depression screening.

Denoising PET images for proton therapy using a residual U-net

The use of proton therapy has the advantage of high dose concentration as it is possible to concentrate the dose on the tumor while suppressing damage to the surrounding normal organs. However, the range uncertainty significantly affects the actual dose distribution in the vicinity of the proton range, limiting the benefit of proton therapy for reducing the dose to normal organs. By measuring the annihilation gamma rays from the produced positron emitters, it is possible to obtain a proton induced positron emission tomography (pPET) image according to the irradiation region of the proton beam. Smoothing with a Gaussian filter is generally used to denoise PET images; however, this approach lowers the spatial resolution. Furthermore, other conventional smoothing processing methods may deteriorate the steep region of the pPET images. In this study, we proposed a denoising method based on a Residual U-Net for pPET images. We conducted the Monte Carlo simulation and irradiation experiment on a human phantom to obtain pPET data. The accuracy of the range estimation and the image similarity were evaluated for pPET images using the Residual U-Net, a Gaussian filter, a median filter, the block-matching and 3D-filtering (BM3D), and a total variation (TV) filter. Usage of the Residual U-Net yielded effective results corresponding to the range estimation; however, the results of peak-signal-to-noise ratio were identical to those for the Gaussian filter, median filter, BM3D, and TV filter. The proposed method can contribute to improving the accuracy of treatment verification and shortening the PET measurement time.

Positional cloning and comprehensive mutation analysis identified a novel KDM2B mutation in a Japanese family with minor malformations, intellectual disability, and schizophrenia

The importance of epigenetic control in the development of the central nervous system has recently been attracting attention. Methylation patterns of lysine 4 and lysine 36 in histone H3 (H3K4 and H3K36) in the central nervous system are highly conserved among species. Numerous complications of body malformations and neuropsychiatric disorders are due to abnormal histone H3 methylation modifiers. In this study, we analyzed a Japanese family with a dominant inheritance of symptoms including Marfan syndrome-like minor physical anomalies (MPAs), intellectual disability, and schizophrenia (SCZ). We performed positional cloning for this family using a single nucleotide polymorphism (SNP) array and whole-exome sequencing, which revealed a missense coding strand mutation (rs1555289644, NM_032590.4: c.2173G>A, p.A725T) in exon 15 on the plant homeodomain of the KDM2B gene as a possible cause of the disease in the family. The exome sequencing revealed that within the coding region, only a point mutation in KDM2B was present in the region with the highest logarithm of odds score of 2.41 resulting from whole genome linkage analysis. Haplotype analysis revealed co-segregation with four affected family members (IV-9, III-4, IV-5, and IV-8). Lymphoblastoid cell lines from the proband with this mutation showed approximately halved KDM2B expression in comparison with healthy controls. KDM2B acts as an H3K4 and H3K36 histone demethylase. Our findings suggest that haploinsufficiency of KDM2B in the process of development, like other H3K4 and H3K36 methylation modifiers, may have caused MPAs, intellectual disability, and SCZ in this Japanese family.

Positional cloning and comprehensive mutation analysis of a Japanese family with lithium-responsive bipolar disorder identifies a novel DOCK5 mutation

Bipolar disorder (BD) is a severe psychiatric disorder characterized by the recurrence of depressive and manic episodes. Its heritability is high, and many linkage and association studies have been performed. Although various linkage regions and candidate genes have been reported, few have shown sufficient reproducibility, and none have identified the pathogenic genes based on the results of the linkage analysis. To find functional variants that are expected to be rare and have strong genetic effects, we recruited ten healthy individuals, two individuals with unknown status, and six patients with BD or recurrent major depressive disorder (MDD) from a Japanese family consisting of 21 members. We performed a genome-wide linkage analysis using a 100K single-nucleotide polymorphism (SNP) array and microsatellite markers to narrow linkage regions within this family. Subsequently, we performed whole-exome sequencing for two patients with BD to identify genetic mutations in the narrowed linkage regions. Then, we performed co-segregation analysis for DNA variants obtained from the results of the exome sequencing. Finally, we identified a rare heterozygous mutation in exon 31 of DOCK5 (c.3170A>G, p.E1057G). Convergent functional genomics analysis revealed that DOCK5 was listed as one of the biomarkers for mood state and suicidality. Although DOCK5 is still a functionally unknown gene, our findings highlight the possibility of a pathological relationship between BD and DOCK5.

Extension of the ML-EM algorithm for dose estimation using PET in proton therapy: application to an inhomogeneous target

Positron emission tomography (PET) has been used for in vivo treatment verification, mainly for range verification, in proton therapy. Evaluating the direct dose from PET measurements remains challenging; however, it is highly desirable from a clinical perspective. In this study, a method for estimating the dose distribution from the positron emitter distributions was developed using the maximum likelihood expectation maximization algorithm. The 1D spatial relationship between positron emitter distributions and a dose distribution in an inhomogeneous target was inputted into the system matrix based on a filter framework. In contrast, spatial resolution of the PET system and total variation regularization (as prior knowledge for dose distribution) were considered in the 3D image-space. The dose estimation was demonstrated using Monte Carlo simulated PET activity distributions with substantial noise in a head and neck phantom. This mimicked the single field irradiation of the spread-out Bragg peak beams at clinical dose levels. Besides the simple implementation of the algorithm, this strategy achieved a high-speed calculation (30 s for a 3D dose estimation) and accurate dose and range estimations (less than 10% and 2 mm errors at 1-σ values, respectively). The proposed method could be key for using PET for in vivo dose monitoring.

Sleep Disorders in Four Patients With Myotonic Dystrophy Type 1

Sleep disturbances such as excessive daytime sleepiness, central and obstructive sleep apneas, restless legs syndrome, and rapid eye movement sleep dysregulation are prominent in patients with myotonic dystrophy type 1 (DM1). Mild intellectual deficits presented in many patients with DM1. In addition, psychosocial issues caused by neuropsychiatric symptoms are a clinical problem. We herein present the cases of four DM1 patients with sleep disturbances and neuropsychiatric symptoms in the preceding stage of clinically significant muscle symptoms. One of the cases exhibited a sleep disorder and neuropsychiatric symptoms before electromyography showed myotonic discharge, suggesting that careful follow-up is also important. Patients 1 and 2 were first referred to our department due to daytime sleepiness. Patients 3 and 4 were objectively suffering from daytime sleepiness of which they were not subjectively aware of. Patients 1, 3, and 4 obtained high apnea–hypopnea index (AHI) scores, which reflected central and/or obstructive apnea, whereas patient 2 had an AHI score of zero. The daytime cerebrospinal fluid (CSF) orexin levels of all patients ranged from the normal lower limit to low, although they were not as low as those observed in narcolepsy with typical cataplexy. Neuropsychological tests of patients 1 and 2 showed frontal lobe dysfunction. Patients 3 and 4 were diagnosed with mild intellectual disability and autism spectrum disorder, respectively. All patients exhibited indifference toward their own symptoms, which may have resulted from the cognitive decline caused by DM1. Based on family history and/or neurological findings such as myotonia, we suspected DM1 as the cause of their sleep disturbances. Molecular analysis using the triplet repeat-primed polymerase chain reaction (TP PCR) method and Southern blotting, which provided a genetic confirmation of the diagnosis of DM1, were performed. These clinical features of sleep disturbances were unrelated to the length of CTG repeats and are caused by unknown molecular mechanisms. Clinicians should take into account that multisystem involvement in DM1 is hugely variable, and thus, a disabling sleep disorder could overshadow muscle impairment in DM1 patients.

A patient with McLeod syndrome showing involvement of the central sensorimotor tracts for the legs

Background

McLeod syndrome is a rare X-linked recessive acanthocytosis associated with neurological manifestations including progressive chorea, cognitive impairment, psychiatric disturbances, seizures, and sensorimotor axonal polyneuropathy. However, no studies have investigated the functioning of central sensorimotor tracts in patients with McLeod syndrome.

Case presentation

A 66-year-old man had experienced slowly progressive chorea and gait disturbance due to lower limb muscle weakness since his early fifties. Blood examinations showed erythrocyte acanthocytosis and the reduction of Kell antigens in red blood cells. Brain magnetic resonance imaging showed atrophy of the bilateral caudate nuclei and putamen. The diagnosis of McLeod syndrome was confirmed by the presence of a mutation of the XK gene on the X chromosome. Somatosensory-evoked potential and transcranial magnetic stimulation studies demonstrated that the central sensory and motor conduction times were abnormally prolonged for the lower extremity but normal for the upper extremity.

Conclusions

This is the first report of the involvement of the central sensorimotor tracts for the legs in a patient with McLeod syndrome. The clinical neurophysiological technique revealed the central sensorimotor tracts involvements clinically masked by neuropathy.

Working Memory-Related Prefrontal Hemodynamic Responses in University Students: A Correlation Study of Subjective Well-Being and Lifestyle Habits

Identification of social risk factors and the promotion of stress coping mechanisms and mental resilience are topics of interest in the field of mental health. The relationships between risk- or tolerability-associated factors and task-related hemodynamic responses in the prefrontal cortex (PFC) in adolescents may have important implications for mental health challenges. The purpose of this study was to investigate the relationship between task-related PFC hemodynamic activities and subjective well-being or lifestyle habits using wearable near-infrared spectroscopy (NIRS). In this study, after sample refinement to reduce heterogeneity, 20 university students were included in verbal working memory (VWM) task analyses and 21 were included in spatial working memory (SWM) task analyses. The task-related hemodynamic responses were detected using wearable NIRS. To assess the risk- or tolerability-associated factors, the levels of positive and negative affect were assessed using the Subjective Well-Being Inventory (SUBI) and lifestyle habits (such as gaming) were evaluated using a nine-item questionnaire. There was a positive correlation between SUBI positive affect and VWM task-related oxy-hemoglobin signal changes in the right dorsolateral PFC (DLPFC), underlining the significance of subjective well-being as an important independent emotional domain and suggesting the possibility of the differential objective evaluations of subjective well-being in the right PFC. Negative correlations between PFC activities during both VWM and SWM tasks at the left DLPFC and the number of game playing days in 1 week were also statistically significant, suggesting the presence of modality-non-specific hemodynamic regulation by habitual game playing. Each correlation was still robust after the elimination of major confounding impacts. Although further replication studies are warranted to confirm these preliminary results, this investigation of the relationship between task-related PFC hemodynamic activities and emotional domains or lifestyle habits might have clinical significance with regard to primary prevention of mental health issues in university students. To our knowledge, this is the first demonstration of these relationships with the use of wearable NIRS, which enables measurement under near natural conditions and is easy to use in schools or workplaces.

ML-EM algorithm for dose estimation using PET in proton therapy

Positron emission tomography (PET) has been extensively studied and clinically investigated for dose verification in proton therapy. However, the production distributions of positron emitters are not proportional to the dose distribution. Thus, direct dose evaluation is limited when using the conventional PET-based approach. We propose a method for estimating the dose distribution from the positron emitter distributions using the maximum likelihood (ML) expectation maximization (EM) algorithm combined with filtering. In experiments to verify the effectiveness of the proposed method, mono-energetic and spread-out Bragg-peak proton beams were delivered by a synchrotron, and a water target was irradiated at clinical dose levels. Planar PET measurements were performed during beam pauses and after irradiation over a total period of 200 s. In addition, we conducted a Monte Carlo simulation to obtain the required filter functions and analyze the influence of the number of algorithm iterations on estimation. We successfully estimated the 2D dose distributions even under statistical noise in the PET images. The accuracy of the 2D dose estimation was about 10% for both beams at the 1-[Formula: see text] values of relative error. This value is comparable to the deviations in the measured PET activity distributions. For the laterally integrated profile along the beam direction, a low error within 5% was obtained per irradiation value. Moreover, the difference of estimated proton ranges was within 1 mm, and 2D estimation from the PET images was completed in 21 ms. Hence, the proposed algorithm may be applied to real-time dose monitoring. Although this is the first attempt to use the ML-EM algorithm for dose estimation, the proposed method showed high accuracy and speed in the estimation of proton dose distribution from PET data. The proposed method is thus a step forward to exploit the full potential of PET for in vivo dose verification.

Distribution and characteristics of heavy metals in a first-generation monofill site for incinerator residue

This study investigated core samples from a landfill site for incinerator residue. The landfill site is one of the first monofill sites for municipal solid waste incinerator residue in the world. The concentrations of the heavy metals Cd, Cr, Cu, Pb, Zn, and Ni in the landfilled incinerator residues were 1-108, 41-926, 40-5498, 35-9806, 103-11453, and 25-719 mg/kg, respectively. Based on comparisons of heavy metal contents between raw incinerator fly ash and bottom ash reported in the literature, our samples comprised a mixture of incinerator fly ash and bottom ash. Rainfall had removed the dissolvable salts from the incinerator residues. The compositions of incinerator residues from different locations varied markedly. The vertical distribution showed a high heavy metal content in the waste layers, suggesting no vertical movement of heavy metals in this landfill site. A comparison between the experimental data and data calculated from historic records of the original metal compositions of the incinerator residues suggested high mobility of Zn, Cu, and Pb and low mobility of Cr and Cd. This trend was supported by a leaching test of waste layer samples. Zn and Cu were leached more readily at pH 9.0-10.0 and 10.5-11.5, respectively.

Novel pathogenic VPS13A gene mutations in Japanese patients with chorea-acanthocytosis

Objective

To identify mutations in vacuolar protein sorting 13A (VPS13A) for Japanese patients with suspected chorea-acanthocytosis (ChAc).

Methods

We performed a comprehensive mutation screen, including sequencing and copy number variation (CNV) analysis of the VPS13A gene, and chorein Western blotting of erythrocyte ghosts. As the results of the analysis, 17 patients were molecularly diagnosed with ChAc. In addition, we investigated the distribution of VPS13A gene mutations and clinical symptoms in a total of 39 molecularly diagnosed Japanese patients with ChAc, including 22 previously reported cases.

Results

We identified 11 novel pathogenic mutations, including 1 novel CNV. Excluding 5 patients with the unknown symptoms, 97.1% of patients displayed various neuropsychiatric symptoms or forms of cognitive dysfunction during the course of disease. The patients carrying the 2 major mutations representing over half of the mutations, exon 60–61 deletion and exon 37 c.4411C>T (R1471X), were localized in western Japan.

Conclusions

We identified 13 different mutations in VPS13A, including 11 novel mutations, and verified the clinical manifestations in 39 Japanese patients with ChAc.

Novel pathogenic XK mutations in McLeod syndrome and interaction between XK protein and chorein

Objective

To identify XK pathologic mutations in 6 patients with suspected McLeod syndrome (MLS) and a possible interaction between the chorea-acanthocytosis (ChAc)- and MLS-responsible proteins: chorein and XK protein.

Methods

Erythrocyte membrane proteins from patients with suspected MLS and patients with ChAc, ChAc mutant carriers, and normal controls were analyzed by XK and chorein immunoblotting. We performed mutation analysis and XK immunoblotting to molecularly diagnose the patients with suspected MLS. Lysates of cultured cells were co-immunoprecipitated with anti-XK and anti-chorein antibodies.

Results

All suspected MLS cases were molecularly diagnosed with MLS, and novel mutations were identified. The average onset age was 46.8 ± 8 years, which was older than that of the patients with ChAc. The immunoblot analysis revealed remarkably reduced chorein immunoreactivity in all patients with MLS. The immunoprecipitation analysis indicated a direct or indirect chorein-XK interaction.

Conclusions

In this study, XK pathogenic mutations were identified in all 6 MLS cases, including novel mutations. Chorein immunoreactions were significantly reduced in MLS erythrocyte membranes. In addition, we demonstrated a possible interaction between the chorein and XK protein via molecular analysis. The reduction in chorein expression is similar to that between Kell antigens and XK protein, although the chorein-XK interaction is a possibly noncovalent binding unlike the covalent Kell-XK complex. Our results suggest that reduced chorein levels following lack of XK protein are possibly associated with molecular pathogenesis in MLS.

Vertical Distribution of Total Mercury and Mercury Methylation in a Landfill Site in Japan

Mercury is a neurotoxin, with certain organic forms of the element being particularly harmful to humans. The Minamata Convention was adopted to reduce the intentional use and emission of mercury. Because mercury is an element, it cannot be decomposed. Mercury-containing products and mercury used for various processes will eventually enter the waste stream, and landfill sites will become a mercury sink. While landfill sites can be a source of mercury pollution, the behavior of mercury in solid waste within a landfill site is still not fully understood. The purpose of this study was to determine the depth profile of mercury, the levels of methyl mercury (MeHg), and the factors controlling methylation in an old landfill site that received waste for over 30 years. Three sampling cores were selected, and boring sampling was conducted to a maximum depth of 18 m, which reached the bottom layer of the landfill. Total mercury (THg) and MeHg were measured in the samples to determine the characteristics of mercury at different depths. Bacterial species were identified by 16S rRNA amplification and sequencing, because the methylation process is promoted by a series of genes. It was found that the THg concentration was 19–975 ng/g, with a geometric mean of 298 ng/g, which was slightly less than the 400 ng/g concentration recorded 30 years previously. In some samples, MeHg accounted for up to 15–20% of THg, which is far greater than the general level in soils and sediments, although the source of MeHg was unclear. The genetic data indicated that hgcA was present mostly in the upper and lower layers of the three cores, merA was almost as much as hgcA, while the level of merB was hundreds of times less than those of the other two genes. A significant correlation was found between THg and MeHg, as well as between MeHg and MeHg/THg. In addition, a negative correlation was found between THg and merA. The coexistence of the three genes indicated that both methylation and demethylation processes could occur, but the lack of merB was a barrier for demethylation.

The effects of olanzapine treatment on brain regional glucose metabolism in neuroleptic-naive first-episode schizophrenic patients

OBJECTIVE

The current study examined metabolic alterations associated with a positive response to olanzapine and identified brain regions associated with treatment-related improvement of symptoms in neuroleptic-naive first-episode schizophrenic patients using [¹⁸ F]fluoro-deoxy-glucose positron emission tomography analysis.

METHODS

Neuroleptic-naive first-episode schizophrenic patients who showed good or poor clinical responses to olanzapine were assessed using the Positive and Negative Syndrome Scale. Data were analyzed using statistical nonparametric mapping.

RESULTS

Before treatment, responders showed significantly increased metabolism in the superior temporal gyrus and cerebellum compared with healthy controls. Glucose metabolism in responders was significantly increased after treatment in the left precentral gyrus, left postcentral gyrus, and left paracentral lobule, and significantly decreased in the left hypothalamus. An analysis of the Positive and Negative Syndrome Scale symptoms associated with olanzapine treatment revealed that "suspiciousness/persecution" scores were positively correlated with metabolic changes in the right superior frontal gyrus.

CONCLUSIONS

These findings provide evidence of the neural mechanisms underlying the effects of olanzapine on metabolism in the early stages of schizophrenia.

Preoperative prediction for regaining ambulatory ability in paretic non-ambulatory patients with metastatic spinal cord compression

STUDY DESIGN

Retrospective multicenter study.

OBJECTIVES

To analyze the predictive factors for postoperative ambulatory recovery in paretic non-ambulatory patients with metastatic spinal cord compression (MSCC).

SETTING

Japan.

METHODS

Eighty-two consecutive patients (74.4% men; mean age, 66.2 years) who could not walk before surgery due to cervical or thoracic MSCC and underwent posterior decompressive surgery between 2003 and 2014 were included. Patients were divided into two groups according to ambulatory status at 6 weeks after surgery: recovery (group R) and non-recovery (group NR). To evaluate the speed of progression of motor deficits, we assessed the period from onset of neurological symptoms to gait inability (T1).

RESULTS

Fifty patients (61.0%) regained the ability to walk (group R). The period of T1 demonstrated a positive correlation with probability of ambulatory recovery (P=0.00; Kendall's tau-b=0.38), and a receiver operating characteristic curve analysis showed that the cutoff value of T1 was 5 days (area under the curve=0.72; P=0.001). In multivariate analysis, <6 days of T1 was one of the independent risk factors for failing to regain ambulatory ability (odds ratio, 8.74; P=0.00).

CONCLUSIONS

The speed of progression of motor deficits can independently and powerfully predict the chance of postoperative ambulatory recovery as well as previously identified predictors. Since information about the speed of progression can be obtained easily by interviewing patients or family members, even if the patient is in an urgent state, our results will be helpful in clinical decision-making.

Sensor-Based Control of a Nine-Link Biped

We aimed to realize smooth 3D biped walking in a robot through control based on information obtained from various sensors. We employed a method to control walking by divid ing it into motions in the sagittal plane and in the lateral plane. We treated motion in the lateral plane as a regulator prob lem with two equilibrium states. We also used relatively low gain feedback coefficients obtained from the optimal regula tor theory. For motion in the sagittal plane, we put the body speed close to the smooth speed function given in advance by controlling the ankle torque.

The effectiveness of the proposed control method was ex amined by computer simulation and proved by experiments with our BLR-G2 walking robot. The BLR-G2 is equipped with foot pressure and ankle torque sensors to provide infor mation about the condition of contact with the floor. The sole and ankle driving actuators undergo force/torgue feedback control based on the sensor information. These contributed toward realizing smooth walking with the sole firmly gripping the floor.

[Feasibility and Safety of Dexmedetomidine Sedation in Transarterial Embolization for Hepatocellular Carcinoma with Hepatitis C-Related Cirrhosis]

BACKGROUND

Dexmedetomidine (Precedex®)is an agonist of a2-adrenergic receptors in certain parts of the brain. It was approved for "procedural sedation in the non-intubation in under local anesthesia" in June 2013 in Japan. However, because of metabolism delay, dexmedetomidine has to be administered carefully to patients with liver dysfunction.

PURPOSE

To evaluate the feasibility and safety of sedation using dexmedetomidine in percutaneous arterial chemoembolization for hepatocellular carcinoma with liver dysfunction.

METHODS

Thirty consecutive cases of percutaneous arterial chemoembolization for hepatocellular carcinoma with hepatitis C-related cirrhosis(male, 23; female, 7; age, 74±5.9; weight, 62.7±12.3 kg; Child-Pugh A, 23; Child-Pugh B, 7)were analyzed retrospectively. Dexmedetomidine was administered at 3 mg/kg/h for 15 minutes as the initial loading dose and at 0.4 mg/kg/h as the maintenance dose. The sedation level was evaluated using the Ramsay sedation scale.

RESULTS

In 30 of 30 cases, percutaneous arterial chemoembolization therapy could be performed with dexme- detomidine sedation. In 27 of 30 cases, the procedure was completed with the maintenance dose of 0.4 mg/kg/h. In 3 of 30 cases, the maintenance dose was increased to 0.6 mg/kg/h because of patient body motion. The mean administration time of dexmedetomidine was 82±30 minutes. The level of sedation measured with the Ramsay sedation scale at the end of the procedure was 3 points in 29 cases and 5 points in one case. Adverse events occurred in 3 of 30 cases. Intravenous drip leakage occurred in one case, vertigo occurred in one case, and vomiting occurred in one case. There were no adverse events requiring treatment.

CONCLUSION

Sedation with dexmedetomidine in percutaneous arterial chemoembolization for hepatocellular carcinoma with liver dysfunction was feasible and safe.

Simultaneous analysis of nanoparticles and small molecules by high-performance liquid chromatography using a silica monolithic column

A high-performance liquid chromatography method using a commercially available silica monolithic column for the simultaneous analysis of nanoparticles and small molecules was developed. The method uses the micrometer-sized flow-through pores and nanometer-sized mesopores of the monolithic column for separation: first, size separation of nanoparticles was performed by the micrometer-sized pores using the hydrodynamic mode, and then small molecules were separated by the nanometer-sized pores using the normal-phase mode. The method was used to evaluate and compare three existing methods for purifying nanoparticles and to analyse nanoparticle stability. The bimodal structure of the monolithic column is promising for the simultaneous separation of nanoparticles and small molecules.

New type of encephalomyelitis responsive to trimethoprim/sulfamethoxazole treatment in Japan

Objective:

To determine the causative pathogen and investigate the effective treatment of a new type of encephalomyelitis with an unknown pathogen in Japan and report the preliminary ultrastructural and genomic characterization of the causative agent.

Methods:

From 2005 to 2012, we treated 4 Japanese patients with geographic clustering and comparable clinical features, serum/CSF cytology, and radiologic findings. Brain biopsy was conducted in all patients to analyze neuropathologic changes by histology, and electron microscopy was applied to reveal the features of the putative pathogen. Genomic DNA was obtained from the affected brain tissues and CSF, and an unbiased high-throughput sequencing approach was used to screen for specific genomic sequences indicative of the pathogen origin.

Results:

All patients exhibited progressive dementia with involuntary tongue movements. Cytologic examination of CSF revealed elevated mononuclear cells. Abnormal MRI signals were observed in temporal lobes, subcortical white matter, and spinal cord. Biopsied brain tissue exhibited aggregated periodic acid-Schiff–positive macrophages and 2–7 μm diameter round/oval bodies without nuclei or cell walls scattered around the vessels. Unbiased high-throughput sequencing identified more than 100 archaea-specific DNA fragments. All patients were responsive to trimethoprim/sulfamethoxazole (TMP-SMX) plus corticosteroid therapy.

Conclusions:

We report 4 cases of encephalomyelitis due to an unknown pathogen. On the basis of ultrastructural and genomic studies, we propose a new disease entity resulting from a causative pathogen having archaeal features. TMP-SMX therapy was effective against this new type of encephalomyelitis.

Evaluation of an aspiration-type semiautomatic cutting biopsy needle

PURPOSE

The purpose of this study was to evaluate an aspiration-type semiautomatic cutting biopsy needle for biopsy of bovine tissue.

MATERIAL AND METHODS

Aspiration-type semiautomatic cutting biopsy needles (18 gauge × 160 mm) with aspiration (Group A), aspiration-type semiautomatic biopsy needles without aspiration (Group Wo), or normal-type semiautomatic biopsy needles (18 gauge × 150 mm) (Group N) were used in 10 biopsies each of bovine liver or lung. The specimens were weighed with an electronic balance.

RESULTS

Mean (standard deviation) weights for bovine liver specimens in Groups A, Wo, and N were 6.80 (0.615) mg, 5.62 (0.843) mg, and 4.19 (0.140) mg, respectively. Mean weights of bovine lung specimens from Groups A, Wo, and N were 2.98 (0.828) mg, 2.67 (0.832) mg, and 1.94 (0.864) mg, respectively. A significant difference was seen between the 3 groups for bovine liver. However, a significant difference was only seen between Groups A and N for bovine lung.

CONCLUSION

Bovine liver and lung specimens obtained using the aspiration-type semiautomatic cutting biopsy needle were heavier than those obtained using the normal-type semiautomatic biopsy needle.

Chorein, the protein responsible for chorea-acanthocytosis, interacts with β-adducin and β-actin

Chorea-acanthocytosis (ChAc) is an autosomal, recessive hereditary disease characterized by striatal neurodegeneration and acanthocytosis, and caused by loss of function mutations in the vacuolar protein sorting 13 homolog A (VPS13A) gene. VPS13A encodes chorein whose physiological function at the molecular level is poorly understood. In this study, we show that chorein interacts with β-adducin and β-actin. We first compare protein expression in human erythrocyte membranes using proteomic analysis. Protein levels of β-adducin isoform 1 and β-actin are markedly decreased in erythrocyte membranes from a ChAc patient. Subsequent co-immunoprecipitation (co-IP) and reverse co-IP assays using extracts from chorein-overexpressing human embryonic kidney 293 (HEK293) cells, shows that β-adducin (isoforms 1 and 2) and β-actin interact with chorein. Immunocytochemical analysis using chorein-overexpressing HEK293 cells demonstrates co-localization of chorein with β-adducin and β-actin. In addition, immunoreactivity of β-adducin isoform 1 is significantly decreased in the striatum of gene-targeted ChAc-model mice. Adducin and actin are membrane cytoskeletal proteins, involved in synaptic function. Expression of β-adducin is restricted to the brain and hematopoietic tissues, corresponding to the main pathological lesions of ChAc, and thereby implicating β-adducin and β-actin in ChAc pathogenesis.