"KAIZEN" method realizing implementation of deep-learning models for COVID-19 CT diagnosis in real world hospitals.

Numerous COVID-19 diagnostic imaging Artificial Intelligence (AI) studies exist. However, none of their models were of potential clinical use, primarily owing to methodological defects and the lack of implementation considerations for inference. In this study, all development processes of the deep-learning models are performed based on strict criteria of the "KAIZEN checklist", which is proposed based on previous AI development guidelines to overcome the deficiencies mentioned above. We develop and evaluate two binary-classification deep-learning models to triage COVID-19: a slice model examining a Computed Tomography (CT) slice to find COVID-19 lesions; a series model examining a series of CT images to find an infected patient. We collected 2,400,200 CT slices from twelve emergency centers in Japan. Area Under Curve (AUC) and accuracy were calculated for classification performance. The inference time of the system that includes these two models were measured. For validation data, the slice and series models recognized COVID-19 with AUCs and accuracies of 0.989 and 0.982, 95.9% and 93.0% respectively. For test data, the models' AUCs and accuracies were 0.958 and 0.953, 90.0% and 91.4% respectively. The average inference time per case was 2.83 s. Our deep-learning system realizes accuracy and inference speed high enough for practical use. The systems have already been implemented in four hospitals and eight are under progression. We released an application software and implementation code for free in a highly usable state to allow its use in Japan and globally.

A transchromosomic rat model with human chromosome 21 shows robust Down syndrome features.

Progress in earlier detection and clinical management has increased life expectancy and quality of life in people with Down syndrome (DS). However, no drug has been approved to help individuals with DS live independently and fully. Although rat models could support more robust physiological, behavioral, and toxicology analysis than mouse models during preclinical validation, no DS rat model is available as a result of technical challenges. We developed a transchromosomic rat model of DS, TcHSA21rat, which contains a freely segregating, EGFP-inserted, human chromosome 21 (HSA21) with >93% of its protein-coding genes. RNA-seq of neonatal forebrains demonstrates that TcHSA21rat expresses HSA21 genes and has an imbalance in global gene expression. Using EGFP as a marker for trisomic cells, flow cytometry analyses of peripheral blood cells from 361 adult TcHSA21rat animals show that 81% of animals retain HSA21 in >80% of cells, the criterion for a "Down syndrome karyotype" in people. TcHSA21rat exhibits learning and memory deficits and shows increased anxiety and hyperactivity. TcHSA21rat recapitulates well-characterized DS brain morphology, including smaller brain volume and reduced cerebellar size. In addition, the rat model shows reduced cerebellar foliation, which is not observed in DS mouse models. Moreover, TcHSA21rat exhibits anomalies in craniofacial morphology, heart development, husbandry, and stature. TcHSA21rat is a robust DS animal model that can facilitate DS basic research and provide a unique tool for preclinical validation to accelerate DS drug development.

SOD1-interacting proteins: Roles of aggregation cores and protein degradation systems.

Cu/Zn superoxide dismutase (SOD1) mutations are associated with amyotrophic lateral sclerosis (ALS). SOD1-positive aggregates in motor neurons, as well as proteins that interact with the aggregates are presumably involved in ALS neurotoxicity. We used a proteomics approach to compare differences in protein expression in spinal cord homogenates from non-transgenic (NTG) and ALS model mice. Using the homogenates, we identified proteins that interacted with SOD1 seeds in vitro. We assessed differences in SOD1-interacting proteins in cell cultures treated with proteasome or autophagy inhibitor. In the first experiment, intermediate filamentous and small heat shock proteins were upregulated in glial cells. We identified 26 protein types that interacted with aggregation cores in ALS model homogenates, and unexpectedly, 40 proteins in were detected in NTG mice. In cell cultures treated with proteasome and autophagy inhibitors, we identified 16 and 11 SOD1-interacting proteins, respectively, and seven proteins in untreated cells. These SOD1-interacting proteins were involved in multiple cellular functions such as protein quality control, cytoskeletal organization, and pathways involved in growth factor signaling and their downstream cascades. The complex interactions between pathways could cause further dysregulation, ultimately leading to fatal cellular dysfunction in ALS.

A non-mosaic transchromosomic mouse model of down syndrome carrying the long arm of human chromosome 21.

Animal models of Down syndrome (DS), trisomic for human chromosome 21 (HSA21) genes or orthologs, provide insights into better understanding and treatment options. The only existing transchromosomic (Tc) mouse DS model, Tc1, carries a HSA21 with over 50 protein coding genes (PCGs) disrupted. Tc1 is mosaic, compromising interpretation of results. Here, we "clone" the 34 MB long arm of HSA21 (HSA21q) as a mouse artificial chromosome (MAC). Through multiple steps of microcell-mediated chromosome transfer, we created a new Tc DS mouse model, Tc(HSA21q;MAC)1Yakaz ("TcMAC21"). TcMAC21 is not mosaic and contains 93% of HSA21q PCGs that are expressed and regulatable. TcMAC21 recapitulates many DS phenotypes including anomalies in heart, craniofacial skeleton and brain, molecular/cellular pathologies, and impairments in learning, memory and synaptic plasticity. TcMAC21 is the most complete genetic mouse model of DS extant and has potential for supporting a wide range of basic and preclinical research.

Enlargement of the infraorbital canal following Caldwell-Luc surgery.

OBJECTIVES: The infraorbital canal (IOC), which runs in the roof of the maxillary sinus, is a useful anatomical landmark for the infraorbital nerve (ION) on computed tomography (CT) images. Enlargement of the IOC on CT images is thought to be a pathological state that usually affects the ION. However, we have frequently observed enlargement of the IOC in patients with a history of radical surgery of the maxillary sinus: so-called Caldwell-Luc (CL) surgery. In this study, the size of the IOC of the maxillary sinus was compared between patients with a history of CL surgery (post-CL IOCs) and those with no history of CL surgery (control IOCs). METHODS: A total of 347 consecutive patients who underwent facial CT from January 2014 to October 2014 for various indications were evaluated. After excluding groove-type IOCs and IOCs with pathological lesions that could affect their diameters, 47 post-CL IOCs in 26 patients were finally compared with 504 control IOCs in 252 patients. To evaluate IOC size, the short-axis diameter of the IOC was measured on a reconstructed coronal image at the level of the posterior pole of the eyeball. RESULTS: The short-axis diameters of the post-CL IOCs and control IOCs were 3.0 ± 0.6 and 1.4 ± 0.3 mm, respectively (p < 0.005). CONCLUSIONS: The short-axis diameters of post-CL IOCs are significantly enlarged (approximately double the diameter) compared to those of control IOCs.

Utility of Amplatzer Vascular Plug with Preoperative Common Hepatic Artery Embolization for Distal Pancreatectomy with En Bloc Celiac Axis Resection.

PURPOSE: To evaluate the feasibility and safety of the Amplatzer vascular plug (AVP) for preoperative common hepatic embolization (CHA) before distal pancreatectomy with en bloc celiac axis resection (DP-CAR) to redistribute blood flow to the stomach and liver via the superior mesenteric artery (SMA). MATERIALS AND METHODS: Four patients (3 males, 1 female; median age 69 years) with locally advanced pancreatic body cancer underwent preoperative CHA embolization with AVP. After embolization, SMA arteriography was performed to confirm the alteration of blood flow from the SMA to the proper hepatic artery. RESULTS: In three of four patients, technical successes were achieved with sufficient margin from the origin of gastroduodenal artery. In one patient, the margin was less than 5 mm, although surgery was successfully performed without any problem. Eventually, all patients underwent the DP-CAR without arterial reconstruction or liver ischemia. CONCLUSIONS: AVP application is feasible and safe as an embolic procedure for preoperative CHA embolization of DP-CAR.

Rice Bran Dietary Supplementation Improves Neurological Symptoms and Loss of Purkinje Cells in Vitamin E-Deficient Mice.

BACKGROUND: Vitamin E (VE, α-tocopherol) is a fat-soluble vitamin and is well known as an antioxidant. A deficiency in VE induces oxidative stress in the brain and causes motor and memory dysfunction. The consumption of a VE-rich diet has been given much attention in recent years, in regards to anti-aging and the prevention of age-related neuronal disorders. METHODS: A VE-deficient mouse model was prepared by feeding the animals a diet lacking VE. In addition, to evaluate the effect of VE-containing rice bran (RB) on VE deficiency, a diet including RB was also provided. VE levels in the brain tissue, as well as in the RB, were measured using an HPLC system. Behavioral tests, including rotarod, wheel running activity, Y-maze, and elevated plus maze were performed. To clarify the effect of VE deficiency and RB, we investigated the induction of heme oxygenase-1 (HO-1). Histological studies were performed using HE staining and immunohistochemical studies were performed using antibodies against glial fibrillary acidic protein (GFAP) and ionized calcium binding adaptor molecule 1 (Iba1). RESULTS: VE in the mouse brain under a VE-deficient diet was decreased, and recovered α-tocopherol levels were observed in the brain of mice fed an RB diet. Motor behavioral scores were decreased in VE-deficient conditions, while the supplementation of RB improved motor function. HO-1, a marker of oxidative stress, was upregulated in the mouse brain under VE deficiency, however, RB supplementation inhibited the increase of HO-1. Histological analyses showed neuronal degeneration of Purkinje cells and decreased GFAP-immunoreactivity of Bergmann glia in the cerebellum. In addition, activated astrocytes and microglia were observed in mice fed the VE-deficient diet. Mice fed the RB diet showed improvement in these histological abnormalities. CONCLUSION: A VE-deficient diet induced motor dysfunction in mice due to the degeneration of Purkinje cells in the cerebellum. Oral supplementation of RB increases VE in the brain and improved the motor dysfunction caused by VE deficiency. Thus, RB or unpolished rice may be a promising VE supplement.

Anthocyanin suppresses the toxicity of Aß deposits through diversion of molecular forms in in vitro and in vivo models of Alzheimer's disease.

OBJECTIVES: The pathogenesis of Alzheimer's disease (AD) is strongly correlated with the aggregation and deposition of the amyloid beta (Aß1-42) peptide in fibrillar form, and many studies have shown that plant-derived polyphenols are capable of attenuating AD progression in various disease models. In this study, we set out to correlate the effects of anthocyanoside extracts (Vaccinium myrtillus anthocyanoside (VMA)) obtained from bilberry on the in vitro progression of Aß fibril formation with the in vivo effects of this compound on AD pathogenesis. METHODS: Thioflavin T fluorescence assays and atomic force microscopy were used to monitor Aß amyloid formation in in vitro assays. Effects of Aß amyloids on cellular viability were assayed using cultured Neuro2a cells. Cognitive effects were probed using mice that simultaneously expressed mutant human Aß precursor and mutant presenilin-2. RESULTS: Addition of VMA inhibited the in vitro formation of Aß peptide fibrils and also reduced the toxicity of these aggregates toward Neuro2a cells. A diet containing 1% VMA prevented the cognitive degeneration in AD mice. Curiously, this diet-derived retention of cognitive ability was not accompanied by a reduction in aggregate deposition in brains; rather, an increase in insoluble deposits was observed compared with mice raised on a control diet. DISCUSSION: The paradoxical increase in insoluble deposits caused by VMA suggests that these polyphenols divert Aß aggregation to an alternate, non-toxic form. This finding underscores the complex effects that polyphenol compounds may exert on amyloid deposition in vivo.

Structural basis of Cu, Zn-superoxide dismutase amyloid fibril formation involves interaction of multiple peptide core regions.

Cu, Zn-superoxide dismutase (SOD1), an enzyme implicated in the progression of familial amyotrophic lateral sclerosis (fALS), forms amyloid fibrils under certain experimental conditions. As part of our efforts to understand ALS pathogenesis, in this study we found that reduction of the intramolecular disulfide bond destabilized the tertiary structure of metal free wild-type SOD1 and greatly enhanced fibril formation in vitro. We also identified fibril core peptides that are resistant to protease digestion by using mass spectroscopy and Edman degradation analyses. Three regions dispersed throughout the sequence were detected as fibril core sequences of SOD1. Interestingly, by using three synthetic peptides that correspond to these identified regions, we determined that each region was capable of fibril formation, either alone or in a mixture containing multiple peptides. It was also revealed that by reducing the disulfide bond and causing a decrease in the structural stability, the amyloid fibril formation of a familial mutant SOD1 G93A was accelerated even under physiological conditions. These results demonstrate that by destabilizing the structure of SOD1 by removing metal ions and breaking the intramolecular disulfide bridge, multiple fibril-forming core regions are exposed, which then interact with each another and form amyloid fibrils under physiological conditions.

Use of a Human Artificial Chromosome for Delivering Trophic Factors in a Rodent Model of Amyotrophic Lateral Sclerosis.

A human artificial chromosome (HAC) is maintained as an episome within a cell and avoids random integration into the host genome. It can transfer multiple and/or large transgenes along with their regulatory elements thereby resembling native chromosomes. Using this HAC system, we established mesenchymal stem cells (MSCs) that simultaneously expressed hepatocyte growth factor, glial cell line-derived neurotrophic factor, and insulin-like growth factor 1, termed HAC-MSCs. This cell line provides an opportunity for stable transplantation and thorough analyses. We then introduced the cells for the treatment of a neurodegenerative disorder, amyotrophic lateral sclerosis. The HAC-MSCs were transplanted via the fourth cerebral ventricle (CV) or intravenous (i.v.) infusion at various ages of recipient mice. Littermate- and sex-matched mice underwent a sham procedure. Compared to the controls, there was an encouraging trend of increased life span via CV transplantation and delayed onset in i.v. infusion 60 days after transplantation. Further, we confirmed a statistically significant increase in life span via CV transplantation at 100 days. This effect was not seen in mice transplanted with MSCs lacking the HAC. We successfully enhanced the trophic potential of the MSCs using the HAC. This strategy could be a promising direction for the treatment of neurodegenerative disorders.

Purification, characterization and cDNA cloning of two natterin-like toxins from the skin secretion of oriental catfish Plotosus lineatus.

The oriental catfish Plotosus lineatus is known to contain proteinaceous toxins in the skin secretion as well as in the venom gland. However, detailed properties and primary structures of the skin toxins have not been clarified. In this study, two proteinaceous toxins (toxins I and II) were purified from the skin secretion of oriental catfish by a combination of gel filtration, anion-exchange HPLC and hydroxyapatite HPLC. Toxins I and II are monomeric simple proteins with almost the same molecular mass (35 kDa for toxin I and 37 kDa for toxin II) and are distinguishable from each other in isoelectric point (6.5 for toxin I and 5.1 for toxin II). Both toxins display lethal, edema-forming and nociceptive activities, although toxin I is significantly more potent than toxin II. The primary structures of toxins I and II were elucidated by cloning experiments based on the determined partial amino acid sequences. Toxins I (317 amino acid residues) and II (315 amino acid residues) share as high as 86% sequence identity with each other and are also highly homologous (56-75% identities) with the known fish natterin-like proteins.

Therapeutic sclerosis of a small liver cyst that caused obstructive jaundice.

The authors describe the case of a small liver cyst (2 cm in diameter) causing obstructive jaundice that was treated with aspiration and therapeutic sclerosis. The procedure was performed with use of a microcatheter and wire system to access the cyst, which was injected with minocycline hydrochloride. At present, 9 months after treatment, the levels of hepatobiliary enzymes are within normal ranges, and no sign of cyst regrowth has been detected on imaging.