School Virus Infection Simulator for customizing school schedules during COVID-19.

Even as the COVID-19 pandemic raged worldwide, schools strived to provide consistent education to their students. In such situations, schools require customized schedules that can address the health concerns and safety of the students to safely reopen and remain open. School schedules can be customized in many ways, and different approaches' impact on education and effectiveness in reducing infectious risks are different. To address this issue, we developed the School Virus Infection Simulation-Model (SVISM) for teachers and education policymakers. By taking into account the students' lesson schedules, classroom volume, air circulation rates in the classrooms, and infectability of the students, SVISM simulates the spread of infection at a school. We demonstrate the impact of several school schedules in self-contained and departmentalized classrooms and evaluate them in terms of the maximum number of students infected simultaneously, and the percentage of face-to-face lessons. The results show that the impact of increasing the classroom ventilation rate is not as stable as that of customizing school schedules. In addition, school schedules can differently impact the maximum number of students infected simultaneously, depending on whether classrooms are self-contained or departmentalized. We found that the maximum number of students infected simultaneously under a certain schedule with 50 percentage of face-to-face lessons in self-contained classrooms is higher than the maximum number of students infected simultaneously having schedules with a higher percentage of face-to-face lessons; this phenomenon was not found in departmentalized classrooms. These results show that the SVISM can help teachers and education policymakers plan school schedules appropriately to reduce the maximum number of students infected simultaneously, while also maintaining a certain rate of face-to-face lessons.

Accuracy and Trending Ability of the Fourth-Generation FloTrac/Vigileo System in Patients With Low Cardiac Index.

OBJECTIVES: To determine the accuracy and trending ability of the fourth-generation FloTrac/Vigileo in patients with low cardiac index by comparing FloTrac/Vigileo-derived cardiac index with that measured by 3-dimensional echocardiography. DESIGN: Prospective clinical study. SETTING: Cardiac surgery operating room in a single cardiovascular center. PARTICIPANTS: Twenty-five patients undergoing elective cardiac resynchronization therapy lead implantation. INTERVENTIONS: FloTrac/Vigileo-derived cardiac index and 3-dimensional echocardiography-derived cardiac index were determined simultaneously before and after phenylephrine bolus and cardiac resynchronization therapy using 3-dimensional echocardiography-derived cardiac index as the reference method. MEASUREMENTS AND MAIN RESULTS: Cardiac index measured by the fourth-generation FloTrac/Vigileo had a wide limit of agreement with that measured by 3-dimensional echocardiography, with a percentage error of 59.1%. The tracking ability of the unit after both phenylephrine administration and cardiac resynchronization therapy were measured by concordance rate, and both were below the acceptable limit (72.7% and 85%, respectively). CONCLUSIONS: The degree of accuracy of the fourth-generation FloTrac/Vigileo in patients with low cardiac index was not acceptable, and high systemic vascular resistance in patients with low cardiac index may have contributed to this inaccuracy. The tracking ability of the fourth-generation FloTrac/Vigileo after phenylephrine administration or cardiac resynchronization therapy was below acceptable limits.

Increment of serum C-peptide measured by glucagon test closely correlates with human relative beta-cell area.

Pancreatic beta-cell mass contributes to glucose tolerance. The aim of this study was to evaluate the relationships between human beta-cell mass and various clinical parameters, including insulin secretory capacity. The study included 32 Japanese patients who underwent pancreatectomy and were naive to oral hypoglycemic agents and insulin. They were classified into those with normal glucose tolerance (n=13), impaired glucose tolerance (n=9) and diabetes (n=10), and their insulin secretory capacity and insulin resistance were evaluated. Immunohistochemistry was used to determine relative beta-cell area (%) which represented the proportion of insulin-positive cell area to whole pancreatic section. Increment of C-peptide immunoreactivity level by glucagon test (ΔC-peptide, increment of serum C-peptide [nmol/L] at 6 min after intravenous injection of 1-mg glucagon; r=0.64, p=0.002), homeostasis model assessment of beta-cell function (HOMA-beta, fasting immunoreactive insulin [µIU/mL] x 20 / (fasting plasma glucose [mmol/L] - 3.5); r=0.50, p=0.003), C-peptide index (CPI, fasting C-peptide [nmol/L] / fasting plasma glucose [mmol/L]; r=0.36, p=0.042), and fasting immunoreactive insulin (F-IRI [pmol/L]; r=0.36, p=0.044) correlated significantly and positively with the relative beta-cell area. The area under the curve of plasma glucose level from 0 to 120 min by 75 g-OGTT (AUC0-120) also correlated significantly and inversely with the relative beta-cell area (r=-0.36, p=0.045). Stepwise multiple regression analysis identified ΔC-peptide as the only independent and significant determinant of the relative beta-cell area. We conclude that ΔC-peptide, HOMA-beta, CPI, F-IRI and AUC0-120 correlated closely with the relative beta-cell area, and ΔC-peptide was the most valuable index for the prediction of the area.

Preserving Mafa expression in diabetic islet ß-cells improves glycemic control in vivo.

The murine Mafa transcription factor is a key regulator of postnatal islet ß-cell activity, affecting insulin transcription, insulin secretion, and ß-cell mass. Human MAFA expression is also markedly decreased in islet ß-cells of type 2 diabetes mellitus (T2DM) patients. Moreover, levels are profoundly reduced in db/db islet ß-cells, a mouse model of T2DM. To examine the significance of this key islet ß-cell-enriched protein to glycemic control under diabetic conditions, we generated transgenic mice that conditionally and specifically produced Mafa in db/db islet ß-cells. Sustained expression of Mafa resulted in significantly lower plasma glucose levels, higher plasma insulin, and augmented islet ß-cell mass. In addition, there was increased expression of insulin, Slc2a2, and newly identified Mafa-regulated genes involved in reducing ß-cell stress, like Gsta1 and Gckr. Importantly, the levels of human GSTA1 were also compromised in T2DM islets. Collectively, these results illustrate how consequential the reduction in Mafa activity is to islet ß-cell function under pathophysiological conditions.

Interferon stimulated gene 15 has an anti-apoptotic effect on MIN6 cells.

Type 1 diabetes, one of two major forms of diabetes, results from the complete destruction of pancreatic beta cells. Viral infection has been suggested to be a trigger of beta cell destruction, the pathogenesis of type 1 diabetes. The aim of this study was to clarify the role of the protein encoded by intherferon stimulated gene (ISG) 15, an antiviral effector, in the development of this clinical entity. We used the mouse beta cell line MIN6 to investigate the role of ISG15 and paid special attention to apoptosis. Although not detected in native MIN6 cells, free ISG15 and ISG15 conjugated proteins were both present in dose-dependently increased amounts following stimulation with interferon alpha. As assessed both by caspase 3/7 activity and an annexin V assay, the percentage of apoptotic MIN6 cells (after exposure to the inflammatory cytokines of interleukin-1beta plus interferon gamma or tumor necrosis factor alpha) was decreased by pretreatment with adenovirus-expressing ISG15 and increased by expressing a short hairpin RNA directed against ISG15. In conclusion, ISG15 has an anti-apoptotic effect on MIN6 cells. Thus, promoting ISG15 expression in the pancreatic beta cells could be a potential therapeutic approach for patients with type 1 diabetes.

Low gene expression levels of activating receptors of natural killer cells (NKG2E and CD94) in patients with fulminant type 1 diabetes.

Fulminant type 1 diabetes is an independent subtype of type 1 diabetes characterized by extremely rapid onset and absence of islet-related autoantibodies. However, detailed pathophysiology of this subtype is poorly understood. In this study, a comprehensive approach was applied to understand the pathogenesis of fulminant type 1 diabetes. We determined the genes that were differentially expressed in fulminant type 1 diabetes compared with type 1A diabetes and healthy control, using gene expression microarray in peripheral blood cells. Using volcano plot analysis, we found reduced expression of killer cell lectin-like receptor subfamily C, member 3 (KLRC3) which encodes NKG2E, a natural killer (NK) cell activating receptor, in fulminant type 1 diabetes, compared with healthy controls. This difference was confirmed by real-time RT-PCR among NK-enriched cells. The expression of KLRD1 (CD94), which forms heterodimer with NKG2E (KLRC3), was also reduced in NK-enriched cells in fulminant type 1 diabetes. Furthermore, flow cytometry showed significantly lower proportion of NK cells among peripheral blood mononuclear cells (PBMCs) in fulminant type 1 diabetes than in healthy controls. In patients with fulminant type 1 diabetes, the relative proportion of NK cells correlated significantly with the time period between onset of fever to the appearance of hyperglycemic-related symptoms. We conclude the presence of reduced NK activating receptor gene expression and low proportion of NK cells in fulminant type 1 diabetes.

Validity of sheet-type portable monitoring device for screening obstructive sleep apnea syndrome.

PURPOSE: The SD-101 is a non-restrictive sheet-like medical device that measures sleep-disordered breathing using pressure sensors that can detect the gravitational alterations in the body that accompany respiratory movement. One report has described that the screening specificity of the SD-101 for mild to moderate obstructive sleep apnea syndrome (OSAS) is relatively low. The present study examines whether the accuracy of the SD-101 for OSAS screening is improved by simultaneously measuring percutaneous oxygen saturation (SpO2). METHODS: Sixty consecutive individuals with suspected OSAS consented to undergo overnight polysomnography (PSG) together with simultaneous measurements of SD-101 and SpO2 at our laboratory. RESULTS: The apnea-hypopnea index (AHI) determined from PSG and the respiratory disturbance index determined from SD-101 measurements significantly correlated (SD-101 alone: r = 0.871, p < 0.0001; SD-101 with SpO2: r = 0.965, p < 0.0001). Bland-Altman plots showed a smaller dispersion for the SD-101 with SpO2 than for the SD-101 alone. The SD-101 with SpO2 detected an AHI of >15 on PSG with a sensitivity and specificity of 96.9 and 90.5 % compared with 87.5 and of 85.7 %, respectively, of the SD-101 alone. CONCLUSIONS: Simultaneously measuring SpO2 improved the accuracy of the SD-101 for OSAS screening. Furthermore, this modality appears to offer high sensitivity and specificity for detecting even moderately severe OSAS.

Preoperative insulin secretion ability and pancreatic parenchymal thickness as useful parameters for predicting postoperative insulin secretion in patients undergoing pancreaticoduodenectomy.

Periampullary malignant neoplasms have been increasing in Japan, mainly in response to an increase in the incidences of pancreatic cancer, and glucose intolerance due to deterioration of insulin secretion is an important problem. We investigated preoperative parameters to predict postoperative insulin secretion and the need for insulin therapy in patients undergoing pancreaticoduodenectomy (PD). Thirty-six patients with malignant neoplasms of periampullary lesions were enrolled. Preoperative pancreatic parenchymal thickness was evaluated by computed tomography. Insulin secretion and glucose tolerance were evaluated by a 75-g oral glucose tolerance test and an intravenous glucagon loading test. The relationships between postoperative insulin secretion and preoperative parameters and the cut-off values for predicting the need for postoperative insulin therapy for glycemic control were investigated. Pancreatic parenchymal thickness and other preoperative parameters, including the increment of serum C-peptide (Δ C-peptide), fasting plasma C-peptide (F-CPR), insulinogenic index (I.I.) and fasting plasma glucose (FPG), were significantly associated with postoperative insulin secretion. Multiple regression analyses revealed that preoperative Δ C-peptide or F-CPR was the most significant determinant of postoperative insulin secretion, followed by pancreatic parenchymal thickness. In the receiver operating characteristic curve, the best preoperative cut-off values for predicting the need for postoperative insulin therapy were a Δ C-peptide of 0.65 ng/mL, a F-CPR of 0.85 ng/mL and a pancreatic parenchymal thickness of 6.0 mm. Both preoperative insulin secretion and pancreatic parenchymal thickness effectively predict postoperative insulin secretion and identify subjects who need postoperative insulin therapy for glycemic control.

Hydroxyoctadecadienoic acid and oxidatively modified peroxiredoxins in the blood of Alzheimer's disease patients and their potential as biomarkers.

Alzheimer's disease (AD) is a neurological disorder that has a considerable impact on the health of the elderly. Although oxidative stress has been implicated in the early stage of this disease, its detailed pathogenesis and therapeutic targets remain unknown. The diagnosis, particularly at the early stage, is important. In the present study, the levels of potential biomarkers such as total hydroxyoctadecadienoic acid (tHODE) and oxidatively modified peroxiredoxin (oxPrx)-2 and oxPrx-6 in plasma and/or erythrocytes were determined by a GC-MS apparatus and by two-dimensional electrophoresis, respectively. It was found that these levels in AD patients were significantly higher than those in the healthy controls. Furthermore, the tHODE levels increased with increasing clinical dementia ratings. Interestingly, vascular dementia patients could be distinguished by the correlation between plasma and erythrocyte tHODE levels or by that of tHODE with oxPrx in erythrocytes. These data further support that oxidative stress is indeed involved in AD and that the correlative measures of tHODE and oxPrx are potential biomarkers for its diagnosis.

Radiation dose reduction and coronary assessability of prospective electrocardiogram-gated computed tomography coronary angiography: comparison with retrospective electrocardiogram-gated helical scan.

OBJECTIVES: The aim of this study was to evaluate radiation dose and coronary assessability of a prospective electrocardiogram (ECG)-gated scan by 64-slice multidetector (row) computed tomography (MDCT)-coronary angiography (CA) compared with a retrospective ECG-gated helical scan. BACKGROUND: The 64-slice MDCT-CA has been widely used; however, a high radiation dose by 64-slice MDCT-CA has been reported. Prospective ECG-gated scan using "step-and-shoot" protocol can reduce radiation exposure effectively. METHODS: MDCT-CA was performed in 229 consecutive patients. Fifty-six patients were excluded because of higher heart rates of >65 beats/min; of patients with heart rates