Layer-specific proteomic profiling of human normal heart.

BACKGROUND: The organized functioning of the anisotropic myocardial layers-including the inner longitudinal, middle circular, and outer longitudinal layers-is essential for stable systemic circulation. However, the proteomic profile of each myocardial layer has not been studied yet. Here, we aimed to elucidate the layer-specific proteomic profile of human cardiac tissue using microscopic sampling. METHODS: Normal hearts were obtained from five autopsy cases, and cardiomyocytes were microdissected separately from the three myocardial layers of the left ventricle. Histological analysis and shotgun proteomic profiling were performed, followed by immunohistochemical analysis. RESULTS: Histologically, no significant changes were observed among the three layers regarding cardiomyocyte diameter and myocardial fibrosis. Totally 1220 proteins-comprising 9404 peptides-were identified from 15 samples, of which the expression levels of 92 proteins were significantly altered among the layers. Gene ontology enrichment analysis revealed that the proteins specifically elevated in the inner and outer layers mostly belonged to the actin filament-binding protein group. In particular, MYH1 was highly expressed in cardiomyocytes in the outer layer, and CTNNA3 was highly expressed at the intercalated disc in the inner layer. CONCLUSIONS: This is the first report on layer-specific proteomic profiling of human normal hearts. Anisotropic profiles of actin filament-binding proteins in myocardial layers may contribute to the anisotropic contractile and conductive abilities of the heart. Knowledge of the layer-specific proteome profiles of a human heart in the normal state can aid in further research on cardiac pathology, such as the prognosis and treatment of focal myocardial infarction.

Spread asymmetry to differentiate nasopalatine duct cysts from radicular cysts arising in the anterior maxilla on computed tomographic images.

OBJECTIVE: The aim of this study was to clarify numerical values for differentiating nasopalatine duct cysts (NPDCs) from radicular cysts (RCs) arising in the anterior maxilla on computed tomography (CT) or cone-beam CT (CBCT) images. METHODS: CT or CBCT images of histologically proven NPDCs (n = 30) and RCs (n = 33) beyond the midline of the maxilla were investigated to determine two asymmetry indices on axial images of the maximum lesion area. The lateral asymmetry index was calculated based on two distances from each of the lateral ends of the lesion to the midsagittal plane. The index was defined as the difference between the two distances divided by their sum. The labio-palatal asymmetry index was determined by the distance between the labial and palatal ends of the lesion and the coronal plane passing through the central incisor root apex. The performance of these indices was assessed by receiver operating characteristic (ROC) analysis. The cutoff values for differentiating NPDCs from RCs were determined with the Youden procedure on the ROC curve. RESULTS: The area under the ROC curve was 0.97 for the lateral asymmetry index and 0.88 for the labio-palatal asymmetry index. The cutoff values for differentiation were 0.36 and 0.68 for the lateral and labio-palatal asymmetry indices, respectively. CONCLUSION: The lateral asymmetry index appeared to be an effective reference for differentiating NPDCs from RCs on CT or CBCT images. When the index was less than the cutoff value, a diagnosis of NPDC was strongly suggested.

Structural and Functional Analysis of the Amorphous Calcium Carbonate-Binding Protein Paramyosin in the Shell of the Pearl Oyster, Pinctada fucata.

Amorphous calcium carbonate (ACC) is an important precursor phase for the formation of aragonite crystals in the shells of Pinctada fucata. To identify the ACC-binding protein in the inner aragonite layer of the shell, extracts from the shell were used in the ACC-binding experiments. Semiquantitative analyses using liquid chromatography-mass spectrometry revealed that paramyosin was strongly associated with ACC in the shell. We discovered that paramyosin, a major component of the adductor muscle, was included in the myostracum, which is the microstructure of the shell attached to the adductor muscle. Purified paramyosin accumulates calcium carbonate and induces the prism structure of aragonite crystals, which is related to the morphology of prism aragonite crystals in the myostracum. Nuclear magnetic resonance measurements revealed that the Glu-rich region was bound to ACC. Activity of the Glu-rich region was stronger than that of the Asp-rich region. These results suggest that paramyosin in the adductor muscle is involved in the formation of aragonite prisms in the myostracum.

Unexpected sudden death on arrival in a healthy middle-aged man associated with COVID-19-related diffuse cardiac injury: A case report.

Coronavirus disease 2019 (COVID-19) is an emerging respiratory infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). COVID-19 has been reported to lead to acute cardiac injury, but previous research indicated that the mechanism is different from that of other viruses and remains poorly understood. Herein, we describe a case of COVID-19-associated sudden death, in a healthy 47-year-old man after developing diffuse cardiac necrosis. Two days before death, the patient developed general malaise without respiratory symptoms. The patient's fatigue worsened with time, and he ultimately developed cardiac arrest in an ambulance; however, resuscitation was unsuccessful. Antigen testing performed at the hospital revealed that the patient was positive for SARS-CoV-2 virus. At autopsy, contraction band necrosis was observed insularly in all areas of the myocardium. CD42b immunohistochemical staining indicated platelet aggregation in the microvessels around the cardiac necrosis area, suggesting COVID-19 can be fatal for healthy people by microcirculatory disturbance due to diffuse cardiac injury arising from platelet activiation. This unique mechanism can be a novel therapeutic target of COVID-19-related cardiac injury.

A case of a motor vehicle collision suspected as associated with development of angiosarcoma.

Trauma has been suspected as a factor leading to development of angiosarcoma, a malignant soft-tissue tumor. We conducted a forensic autopsy to investigate a putative relation between a motor vehicle collision and the driver's later death from angiosarcoma. A vehicle operated by a man in his 60 s collided with an oncoming vehicle at a curve. The victim noticed no injury at the scene. However, 45 days later, he was transferred to an emergency room with dyspnea and bloody sputum. After diagnosis of angiosarcoma, he died of respiratory failure 132 days later. The bereaved family speculated about a relation between the collision and angiosarcoma onset. At autopsy, tumor cells of the scalp had metastasized to the lung, pleura, liver, and spleen. Histopathological examinations revealed characteristic features of angiosarcoma with positive immune-staining for CD31, CD34, and factor VIII. When a person dies some time after a collision, it is designated as a delayed death. In such cases, the relevance of trauma to the person's death is often an issue of concern. Because the interval between trauma and angiosarcoma development was short, only 45 days, the angiosarcoma might be coincidental. Therefore, we rejected the relation. Forensic experts sometimes need to investigate such inquiries.

An instance of homicide by electrocution with hand-made electrode plates.

Homicide by electrocution is rare in forensics, and the identification of the cause of death can be quite difficult when the electric device is removed from the scene. We present an instance where the police were unsure of homicide in the initial investigation. The offender used hand-made electrode plates for electrocution, which produced unique electric marks different from those produced by common electric devices such as electric wires. To the best of our knowledge, this is the first report of homicide by electrocution with electrode plates. We believe that the macroscopic and microscopic findings in this instance are quite valuable for forensic practitioners.

Gastric aspiration in sudden unexpected infant death of Prader-Willi syndrome: immunohistochemical detection of feeding components.

Prader-Willi syndrome (PWS) in infants is characterized by hypotonia and poor sucking with feeding difficulties. Two autopsy cases of sudden unexpected death during sleep after tube feeding are described herein. For one, gastric aspiration caused by the possible milk regurgitation was suspected. Immunohistochemical examination of lung sections was performed using three antibodies to human α-lactalbumin, human gross cystic disease fluid protein 15, and cow whey ß-lactoglobulin. Five cases of sudden unexpected infant death occurring earlier than at 6 months old were selected as controls. Marked immune-staining for infant formula in one PWS subject was evident within terminal bronchioles and alveoli with granular and amorphous features. However, no positive staining was apparent in the other subject, who exhibited contrasting features in milk distribution. Among control cases, one showed mild staining in the bronchiole, but the others did not. The antibody to ß-lactoglobulin reacted specifically with formula, with no nonspecific background. Gastric contents in the airway can be a difficult issue because of the consequent terminal gasping. However, because of an episode of antemortem symptoms of potential regurgitation, and from findings at autopsy such as petechiae, we inferred that fatal regurgitation occurred in this PWS infant after tube feeding. Several clinical reports have described milk aspiration, but this pathological report is the first related to aspiration in PWS during tube feeding.

Usefulness of a deep learning system for diagnosing Sjögren's syndrome using ultrasonography images.

OBJECTIVES: We evaluated the diagnostic performance of a deep learning system for the detection of Sjögren's syndrome (SjS) in ultrasonography (US) images, and compared it with the performance of inexperienced radiologists. METHODS: 100 patients with a confirmed diagnosis of SjS according to both the Japanese criteria and American-European Consensus Group criteria and 100 non-SjS patients that had a dry mouth and suspected SjS but were definitively diagnosed as non-SjS were enrolled in this study. All the patients underwent US scans of both the parotid glands (PG) and submandibular glands (SMG). The training group consisted of 80 SjS patients and 80 non-SjS patients, whereas the test group consisted of 20 SjS patients and 20 non-SjS patients for deep learning analysis. The performance of the deep learning system for diagnosing SjS from the US images was compared with the diagnoses made by three inexperienced radiologists. RESULTS: The accuracy, sensitivity and specificity of the deep learning system for the PG were 89.5, 90.0 and 89.0%, respectively, and those for the inexperienced radiologists were 76.7, 67.0 and 86.3%, respectively. The deep learning system results for the SMG were 84.0, 81.0 and 87.0%, respectively, and those for the inexperienced radiologists were 72.0, 78.0 and 66.0%, respectively. The AUC for the inexperienced radiologists was significantly different from that of the deep learning system. CONCLUSIONS: The deep learning system had a high diagnostic ability for SjS. This suggests that deep learning could be used for diagnostic support when interpreting US images.

Preliminary study on the application of deep learning system to diagnosis of Sjögren's syndrome on CT images.

OBJECTIVES: This study estimated the diagnostic performance of a deep learning system for detection of Sjögren's syndrome (SjS) on CT, and compared it with the performance of radiologists. METHODS: CT images were assessed from 25 patients confirmed to have SjS based on the both Japanese criteria and American-European Consensus Group criteria and 25 control subjects with no parotid gland abnormalities who were examined for other diseases. 10 CT slices were obtained for each patient. From among the total of 500 CT images, 400 images (200 from 20 SjS patients and 200 from 20 control subjects) were employed as the training data set and 100 images (50 from 5 SjS patients and 50 from 5 control subjects) were used as the test data set. The performance of a deep learning system for diagnosing SjS from the CT images was compared with the diagnoses made by six radiologists (three experienced and three inexperienced radiologists). RESULTS: The accuracy, sensitivity, and specificity of the deep learning system were 96.0%, 100% and 92.0%, respectively. The corresponding values of experienced radiologists were 98.3%, 99.3% and 97.3% being equivalent to the deep learning, while those of inexperienced radiologists were 83.5%, 77.9% and 89.2%. The area under the curve of inexperienced radiologists were significantly different from those of the deep learning system and the experienced radiologists. CONCLUSIONS: The deep learning system showed a high diagnostic performance for SjS, suggesting that it could possibly be used for diagnostic support when interpreting CT images.

LRRK1 phosphorylation of Rab7 at S72 links trafficking of EGFR-containing endosomes to its effector RILP.

Ligand-induced activation of epidermal growth factor receptor (EGFR) initiates trafficking events that re-localize the receptor from the cell surface to intracellular endocytic compartments. EGFR-containing endosomes are transported to lysosomes for degradation by the dynein-dynactin motor protein complex. However, this cargo-dependent endosomal trafficking mechanism remains largely uncharacterized. Here, we show that GTP-bound Rab7 is phosphorylated on S72 by leucine-rich repeat kinase 1 (LRRK1) at the endosomal membrane. This phosphorylation promotes the interaction of Rab7 (herein referring to Rab7a) with its effector RILP, resulting in recruitment of the dynein-dynactin complex to Rab7-positive vesicles. This, in turn, facilitates the dynein-driven transport of EGFR-containing endosomes toward the perinuclear region. These findings reveal a mechanism regulating the cargo-specific trafficking of endosomes.

Short-term session of repetitive peripheral magnetic stimulation combined with motor imagery facilitates corticospinal excitability in healthy human participants.

The aim of the present study was to investigate the effects of repetitive peripheral magnetic stimulation (rPMS) combined with motor imagery (MI) on corticospinal excitability. Ten healthy individuals participated in two kinds of short-term sessions: rPMS combined with MI [magnetic stimulation motor imagery (MSMI)] and rPMS alone (magnetic stimulation) on different days. We measured the motor-evoked potentials before and after the session, and the MI ability of each participant using the Movement Imagery Questionnaire-Revised. The post-session/pre-session motor-evoked potential ratio was larger in the MSMI than in the magnetic stimulation condition, and the difference was correlated to the Movement Imagery Questionnaire-Revised score. This suggests that rPMS combined with MI induced greater corticospinal excitability than rPMS alone. This study highlights the possibility that short-term sessions of rPMS combined with MI could have clinical applications in improving the sensorimotor dysfunctions of stroke patients.

Reduced Tyk2 gene expression in ß-cells due to natural mutation determines susceptibility to virus-induced diabetes.

Accumulating evidence suggests that viruses play an important role in the development of diabetes. Although the diabetogenic encephalomyocarditis strain D virus induces diabetes in restricted lines of inbred mice, the susceptibility genes to virus-induced diabetes have not been identified. We report here that novel Tyrosine kinase 2 (Tyk2) gene mutations are present in virus-induced diabetes-sensitive SJL and SWR mice. Mice carrying the mutant Tyk2 gene on the virus-resistant C57BL/6 background are highly sensitive to virus-induced diabetes. Tyk2 gene expression is strongly reduced in Tyk2-mutant mice, associated with low Tyk2 promoter activity, and leads to decreased expression of interferon-inducible genes, resulting in significantly compromised antiviral response. Tyk2-mutant pancreatic ß-cells are unresponsive even to high dose of Type I interferon. Reversal of virus-induced diabetes could be achieved by ß-cell-specific Tyk2 gene expression. Thus, reduced Tyk2 gene expression in pancreatic ß-cells due to natural mutation is responsible for susceptibility to virus-induced diabetes.

Association of the five-factor personality model with prefrontal activation during frontal lobe task performance using two-channel near-infrared spectroscopy.

AIM: The aim of this study was to investigate the biological background of the five-factor model using near-infrared spectroscopy and cognitive tasks. METHODS: Twenty right-handed healthy volunteers participated in this study. Their personality traits were assessed using the NEO Five-Factor Inventory, and changes in oxyhemoglobin concentration ([oxy-Hb]) were measured during cognitive tasks using a wireless near-infrared spectroscopy. RESULTS: The average [oxy-Hb] in the right prefrontal area had a significant positive correlation with the agreeableness score during the Stroop test at incongruent stimulus block. For the verbal fluency task, there were no significant correlations of bilateral [oxy-Hb] changes with any items. CONCLUSION: Higher agreeableness scores may involve less suppression to the default mode network related to resting state brain function. Keeping selective attention during the Stroop test may require more power of concentration than retrieving words during the verbal fluency task.

Prefrontal dysfunction in remitted depression at work reinstatement using near-infrared spectroscopy.

A long-term and/or recurrent sickness absence from work due to depression has been an important health problem in industrial countries. In addition, previous sick leave is a risk factor of recurrence. However, many characteristics, especially biological aspects, have not been investigated in remitted depressive patients who were ready to return to work from sickness absence. Therefore, the purpose of this study is to clarify the pathophysiological characteristics of patients who were at risk for recurrence of sickness absence. We recruited 21 patients and 16 healthy control subjects. All patients were ready to return to work within one month from long-term sickness absence. All subjects were examined for prefrontal function represented by oxyHb changes during the verbal fluency task (VFT) and the Stroop task using near-infrared spectroscopy. Suppressed prefrontal reaction during the VFT and increased prefrontal reaction during the Stroop task were observed in the patient group compared with the control group. Significantly lengthened reaction time was observed in the incongruent condition in the patient group during the Stroop task. Depressive patients showed impaired executive function measured by the Stroop task and had prefrontal dysfunction despite clinical remission. Residual prefrontal dysfunction may be one biological reason for repetitive sickness absence.

[Present knowledge in nutritional aspects of fracture].

Bone fractures are affected by bone mineral density, bone turnover, and risk of falls. Nutritional status could influence all these factors. The preventive effect of higher intake of calcium (1200 - 1500 mg/day) and vitamin D (10 - 20 microg/day) on osteoporotic fractures is well established and these are strongly recommended for the prevention of fractures in European and North American countries. Comparing to Western people, Japanese calcium intake (529+/-285 mg/day, n = 8,964) is much lower. We discuss recent data of other nutrients and factors which may be associated with fractures risk, such as vitamin K, C, B(12), potassium, magnesium, soy isoflavon, and homocysteine, and suggest several recipes and proper food intake to decrease fracture risk in Japanese elderly people as follows. Japanese elderly is recommended to add milk to traditional dish such as Miso soup for enhancement of calcium intake. They should take fish at least every other day to take more vitamin D and protein. Also, reinforcements of soy, fruit, and vegetable intake to increase vitamin K, vitamin C, potassium, magnesium, soy isoflavon and to decrease in homocysteine formation are recommended.

Knowledge and attitude towards suicide among medical students in Japan: preliminary study.

Japan has one of the highest suicide rates in the world. Suicides numbered 32,863 in 1998 and have exceeded 30,000 in every subsequent year. Education of those involved in general and psychosocial patient care can contribute greatly to suicide prevention. The authors administered a brief knowledge and attitude assessment questionnaire concerning suicide to students in their first, third, and fifth years at a Japanese medical school. Participants numbered 160 (94 men with a mean age of 21.8 years, SD = 3.01, and 66 women with a mean age of 21.2 years, SD = 2.64); 59 first year, 52 third year, and 49 in their fifth year. The questionnaire consists of eight multiple-choice questions asking knowledge of suicide and one open-ended question asking attitude. In the knowledge part, only about half of the items were answered correctly (mean score was 4.21, SD = 1.28). A significant difference was observed in prevalence of attitudes as categorical variables between student years (P = 0.001). Sympathetic comments increased along with student years, while critical comments decreased. Given the frequent and interventional opportunities of primary-care medical contacts, poor understanding of suicide from the medical viewpoint was of concern. Moreover, judgmental attitudes were common, especially in earlier school years. Better informed, more understanding physicians and other health professionals could contribute greatly to prevention.

[Calcium intake of osteoporotic patients in Japan].

Osteoporotic patients appear to have low calcium intake, however, their average intake was around 750-800 mg/day investigated by food frequency questionnaire in Japanese women, and it was much higher than the analysis of the 2002 National Nutrition Survey in Japan (557 +/- 270 mg/day). Calcium intakes in these patients were widely ranged from 169 to 2,021 mg/day. The minimum is so low that high bone turnover may increase fracture risk, and the maximum is so high that renal dysfunction might occur in patients treated with active vitamin D and/or calcium supplementation. Therefore, physicians should observe carefully the patient's dietary calcium intake during the treatment with active vitamin D and/or calcium administration.