Orthotopic transplantation of the bioengineered lung using a mouse-scale perfusion-based bioreactor and human primary endothelial cells.

Whole lung engineering and the transplantation of its products is an ambitious goal and ultimately a viable solution for alleviating the donor-shortage crisis for lung transplants. There are several limitations currently impeding progress in the field with a major obstacle being efficient revascularization of decellularized scaffolds, which requires an extremely large number of cells when using larger pre-clinical animal models. Here, we developed a simple but effective experimental pulmonary bioengineering platform by utilizing the lung as a scaffold. Revascularization of pulmonary vasculature using human umbilical cord vein endothelial cells was feasible using a novel in-house developed perfusion-based bioreactor. The endothelial lumens formed in the peripheral alveolar area were confirmed using a transmission electron microscope. The quality of engineered lung vasculature was evaluated using box-counting analysis of histological images. The engineered mouse lungs were successfully transplanted into the orthotopic thoracic cavity. The engineered vasculature in the lung scaffold showed blood perfusion after transplantation without significant hemorrhage. The mouse-based lung bioengineering system can be utilized as an efficient ex-vivo screening platform for lung tissue engineering.

Edoxaban eliminates hypercoagulability evoked by transient temperature changes in human whole blood.

Background: Thrombosis is a common critical complication relating to radiofrequency catheter ablation and cryoablation. There is a possibility that high-temperature stimulation during radiofrequency ablation or low-temperature stimulation during cryoablation may affect the coagulability of blood. In this study, we aimed to determine the impacts of transient temperature stimulations on the coagulability of whole blood and to clarify if edoxaban suppressed the hypercoagulability. Methods: Citrated blood samples were drawn from 41 healthy subjects. Some blood samples were mixed with tissue factor (TF) and several concentrations of edoxaban (50, 100, and 200 ng/mL). Blood samples were exposed to several temperature stimulations for 1 min: heat stimulation (50°C) or cryostimulation (-20°C), and compared with control (37°C). Repeated cryostimulations or sequential cryo- and heat stimulation were also applied. Coagulability of whole blood was measured using a dielectric blood coagulometry. As an index of coagulability, the end of acceleration time (EAT) was used. Results: Both heat- and cryostimulations significantly shortened the EAT compared to the control, indicating that hypercoagulability was induced by temperature stimulations. Application of TF enhanced and extended the hypercoagulability after the temperature stimulations. Sequential application of cryo- followed by heat stimulation further enhanced the hypercoagulability of blood. Application of edoxaban increased the EAT in a concentration-dependent manner in control condition. Edoxaban at 100 or 200 ng/mL completely suppressed the shortening of EAT evoked by these temperature stimulations. Conclusion: Transient temperature stimulations evoked hypercoagulability regardless of cryo- or heat stimulation. Edoxaban with 100 ng/mL or more eliminated this temperature-stimulated hypercoagulability.

Stimulatory and Inhibitory Effects of Steroid Hormones and Human Cytochrome P450 (CYP) 3A Inhibitors on Cortisol 6ß-Hydroxylation Catalyzed by CYP3A Subfamilies.

OBJECTIVE: The inhibitory and stimulatory effects of several compounds, including steroid hormones and azole antifungal agents, on cortisol 6ß-hydroxylation activity by cytochrome P450 (CYP) 3A4, polymorphically expressed CYP3A5, and fetal CYP3A7 were compared with those on testosterone 6ß-hydroxylation to clarify the catalytic properties of the predominant forms of the human CYP3A subfamily. METHODS: 6ß-Hydroxylation activities of cortisol and testosterone by CYP3A4, CYP3A5, and CYP3A7 in the absence or presence of dehydroepiandrosterone (DHEA), α-naphthoflavone (ANF), ketoconazole, itraconazole, and voriconazole were measured using high-performance liquid chromatography. RESULTS: Lower concentrations of DHEA and ANF increased cortisol 6ß-hydroxylation activities catalyzed by CYP3A4 but not those catalyzed by CYP3A5 and CYP3A7. The inhibition strength of azole antifungal agents against cortisol 6ß-hydroxylation catalyzed by all CYP3A subfamilies was similar to that of testosterone 6ß-hydroxylation. Although the Michaelis constant (Km) increased 2-fold in the presence of 20 µM DHEA compared to that of the control, the maximal velocity (Vmax) values gradually increased with increasing DHEA. For ANF, both Km and Vmax values increased, although the Km value decreased at 2.5 µM concentrations. Ketoconazole and itraconazole competitively inhibited cortisol 6ß-hydroxylation mediated by CYP3A4 with similar inhibition constants. CONCLUSION: The inhibitory/stimulatory pattern among CYP3A subfamily members differed between cortisol and testosterone, and CYP3A4 was found to be the most sensitive in terms of inhibition by azole antifungals among the CYP3A subfamily members investigated.

Kerr-lens mode-locked 49-fs Tm3+:YScO3 single-crystal laser at 2.1†µm.

We report on a continuous wave (CW) and Kerr-lens mode-locked (KLM) Tm3+:YScO3 single-crystal laser centered at 2.1 µm. Efficient CW laser operation with a maximum slope efficiency of 51% was achieved under in-band pumping by an Er:Yb fiber master oscillator power amplifier (MOPA). In KLM operation, pulses as short as 49 fs corresponding to seven optical cycles were achieved at a repetition rate of 96.7 MHz with an average output power of 126 mW. Such short pulse durations are enabled by the inhomogeneously broadened emission spectrum of Tm3+:YScO3 extending to above 2200 nm.

The Regulation Pathway of VEGF Gene Expression Is Different between 2D Cells and 3D Spheroids in Human Lung Cancer Cells.

Angiogenesis is involved in the malignant transformation of cancers. Vascular endothelial growth factor (VEGF) is important in inducing angiogenesis. Cultured cells play an important role in analyzing the regulation of VEGF expression, and it is revealed that VEGF expression is induced under hypoxia. However, it has been shown that there are differences in the pathway for gene expression between two-dimensional (2D) cells and in vivo cells. Three-dimensional (3D) spheroids constructed in 3D culture with a gene expression pattern more similar to that of in vivo cells than 2D cells have been used to solve this problem. This study analyzed the VEGF gene expression pathway in 3D spheroids of human lung cancer cells, A549 and H1703. Hypoxia-inducible factor-1α (HIF-1α) and aryl hydrocarbon receptor nuclear translocator (ARNT) regulated VEGF gene expression in 3D spheroids. However, VEGF gene expression was not regulated by HIF-1α in 2D cells. To conclude, we found that the regulatory pathway of VEGF gene expression is different between 2D cells and 3D spheroids in human lung cancer cells. These results suggest the possibility of a new VEGF gene expression regulation pathway in vivo. In addition, they show useful knowledge for the analysis of angiogenesis induction mechanisms and also demonstrate the usefulness of 3D spheroids.

Using 3D-printed fracture networks to obtain porosity, permeability, and tracer response datasets.

An in-depth understanding of flow through fractured media is vital to optimise engineering applications, including geothermal energy production, enhanced oil recovery, CO2 storage, and nuclear waste disposal. Advances in 3D-printing technologies have made it possible to generate 3D printed fracture networks with different fracture characteristics. By performing fluid flow experiments in the 3D-printed fractured networks, the impact of the fracture parameters, such as the density, orientation, aperture, dip, and azimuth, on the overall flow can be investigated. This data article contains a detailed description of the framework followed to design fractured networks with different fracture parameters and to create 3D-printed samples, including fracture networks. Furthermore, it contains the experimental protocols used to measure the porosity, permeability, and tracer responses of the 3D-printed samples. The generated datasets provided include geometry data describing the fracture networks, as well as porosity, permeability and tracer response data obtained from flow experiments conducted in the fracture networks.

Spectroscopy and 2.1 µm laser operation of Czochralski-grown Tm3+:YScO3 crystals.

We report on growth, temperature-dependent spectroscopy, and laser experiments of Tm3+-doped YScO3 mixed sesquioxide crystals. For the first time, cm3-scale laser quality Tm3+:YScO3 crystals with 2.2 at.% and 3.1 at.% doping levels were grown by the Czochralski method from iridium crucibles. We reveal that the structural disorder in the mixed crystals allows for broad and smooth spectral features even at cryogenic temperatures. We obtained the first continuous wave laser operation in this material at wavelengths around 2100 nm using a laser diode emitting at 780 nm as a pump source. A maximum slope efficiency of 45% was achieved using a Tm3 + (3.1 at.%):YScO3 crystal. Our findings demonstrate the high potential of Tm3+-doped mixed sesquioxides for efficient ultrafast pulse generation in the 2.1 µm range.

Educational Approaches That Enhance Online Clinical Clerkship during the COVID-19 Pandemic.

Objective This cross-sectional national study determined which educational approaches are associated with the effectiveness of online clerkship for medical students. Method A survey was conducted for medical students at 78 medical schools in Japan from May 29 to June 14, 2020. It comprised the following aspects: (a) participants' profiles, (b) number of opportunities to learn from each educational approach (lecture, medical quiz, assignment, oral presentation, observation of a physician's practice, clinical skill practice, participation in interprofessional meetings, and interactive discussions with physicians) in online clerkship, (c) frequency of technical problems, and (d) educational outcome measurement (satisfaction, motivation, knowledge acquisition, skill acquisition, change in self-study time, and understanding of the importance of medical care team). Results Of the 2,640 respondents, 2,594 (98.3%) agreed to cooperate. Ultimately, 1,711 matched our inclusion criteria. All educational approaches but assignments were positively associated with satisfaction and motivation. All educational approaches excluding assignment submission and interprofessional meeting were positively associated with knowledge acquisition. Observation, practice, and interprofessional meeting were positively associated with skill acquisition. Only assignment submission was positively associated with the change in self-study time. Educational approaches excluding medical quizzes were positively associated with understanding the importance of the medical care team. Technical problems were negatively associated with motivation, knowledge acquisition, and skill acquisition. Conclusions Educators should implement various educational approaches, especially observation and practice, even in online clinical clerkship. They also need to minimize the technical problems associated with the Internet, as they reduce the effectiveness of online clerkship.

Predicting the effectiveness of the online clinical clerkship curriculum: Development of a multivariate prediction model and validation study.

Given scientific and technological advancements, expectations of online medical education are increasing. However, there is no way to predict the effectiveness of online clinical clerkship curricula. To develop a prediction model, we conducted cross-sectional national surveys in Japan. Social media surveys were conducted among medical students in Japan during the periods May-June 2020 and February-March 2021. We used the former for the derivation dataset and the latter for the validation dataset. We asked students questions in three areas: 1) opportunities to learn from each educational approach (lectures, medical quizzes, assignments, oral presentations, observation of physicians' practice, clinical skills practice, participation in interprofessional meetings, and interactive discussions with physicians) in online clinical clerkships compared to face-to-face, 2) frequency of technical problems on online platforms, and 3) satisfaction and motivation as outcome measurements. We developed a scoring system based on a multivariate prediction model for satisfaction and motivation in a cross-sectional study of 1,671 medical students during the period May-June 2020. We externally validated this scoring with a cross-sectional study of 106 medical students during February-March 2021 and assessed its predictive performance. The final prediction models in the derivation dataset included eight variables (frequency of lectures, medical quizzes, oral presentations, observation of physicians' practice, clinical skills practice, participation in interprofessional meetings, interactive discussions with physicians, and technical problems). We applied the prediction models created using the derivation dataset to a validation dataset. The prediction performance values, based on the area under the receiver operating characteristic curve, were 0.69 for satisfaction (sensitivity, 0.50; specificity, 0.89) and 0.75 for motivation (sensitivity, 0.71; specificity, 0.85). We developed a prediction model for the effectiveness of the online clinical clerkship curriculum, based on students' satisfaction and motivation. Our model will accurately predict and improve the online clinical clerkship curriculum effectiveness.

Flow estimation solely from image data through persistent homology analysis.

Topological data analysis is an emerging concept of data analysis for characterizing shapes. A state-of-the-art tool in topological data analysis is persistent homology, which is expected to summarize quantified topological and geometric features. Although persistent homology is useful for revealing the topological and geometric information, it is difficult to interpret the parameters of persistent homology themselves and difficult to directly relate the parameters to physical properties. In this study, we focus on connectivity and apertures of flow channels detected from persistent homology analysis. We propose a method to estimate permeability in fracture networks from parameters of persistent homology. Synthetic 3D fracture network patterns and their direct flow simulations are used for the validation. The results suggest that the persistent homology can estimate fluid flow in fracture network based on the image data. This method can easily derive the flow phenomena based on the information of the structure.

Sub-6 optical-cycle Kerr-lens mode-locked Tm:Lu2O3 and Tm:Sc2O3 combined gain media laser at 2.1 µm.

We present a combined gain media Kerr-lens mode-locked laser based on a Tm:Lu2O3 ceramic and a Tm:Sc2O3 single crystal. Pulses as short as 41 fs, corresponding to less than 6 optical cycles, were obtained with an average output power of 42 mW at a wavelength of 2.1 µm and a repetition rate of 93.3 MHz. Furthermore, a maximum average power of 316 mW with a pulse duration of 73 fs was achieved.

Author Correction: Differential Assessment of Factor Xa Activity and Global Blood Coagulability Utilizing Novel Dielectric Coagulometry.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

Differential Assessment of Factor Xa Activity and Global Blood Coagulability Utilizing Novel Dielectric Coagulometry.

An easy-to-use assessment for activated factor X (FXa) is lacking despite its pivotal role in the coagulation. Dielectric blood coagulometry (DBCM) was recently invented as a novel assessment tool for determining the whole blood coagulability by measuring the temporal change in the permittivity of blood. We previously reported that it could evaluate the global blood coagulability. This study aimed to apply the DBCM for assessing FXa activity and its inhibition by anticoagulants. We performed the DBCM analysis along with measurement of the FXa activity by a fluorometric assay in samples from healthy subjects, and identified a new index named maximum acceleration time (MAT) that had a correlation to the FXa activity. Next the DBCM analysis was performed using blood samples mixed with anticoagulants (unfractionated heparin, dalteparin, and edoxaban). Blood samples with three anticoagulants had different profiles of the temporal change in the permittivity, reflecting their different selectivity for FXa. We compared the MAT with the anti-FXa activity assay, and found that the prolongation of MAT was similarly correlated with the anti-FXa activity regardless of the type of anticoagulants. In conclusion, the DBCM has the possibility for evaluating the innate FXa activity and effect of anticoagulants focusing on their FXa inhibition.

Current Practice and Outcomes of Peritoneal Dialysis in the Nippon Medical School Musashi Kosugi Hospital.

INTRODUCTION: Various innovations for preventing complications and improving a patient's quality of life have been implemented for peritoneal dialysis (PD), which was established in Japan approximately 35 years ago and introduced at our hospital in 1999. Herein, we investigate the outcomes of patients undergoing PD to identify approaches for improving their long-term prognosis. METHODS: This retrospective study included 114 patients who underwent PD between September 1999 and August 2017 and included various parameters such as patient survival rate, technical survival rate, cause (s) of PD withdrawal, incidence of peritonitis, dialysis duration, and change in residual renal function (RRF). Furthermore, factors associated with PD withdrawal and duration, as well as risk factors for peritonitis, were examined. RESULTS: Mean (± standard deviation) PD duration was 35.62 (±29.88) months in all patients and 37.16 (±34.09) months in 58 patients who withdrew from treatment. Five-year continuance and survival rates were 40.41% and 55.74%, respectively (p=0.0061). However, in patients aged ≥65 years, the continuance and survival rates were not significantly different (p=0.1250). Furthermore, the continuance and survival rates in diabetic patients were not significantly different from those of non-diabetic patients (p=0.1334 and 0.7140, respectively). Comparison of changes in RRF in young and elderly patients revealed that it was not significantly sustained in elderly patients (p=0.0259). The Cox proportional hazards model revealed that age (p=0.0455) and total cholesterol levels (p=0.0494) were independent risk factors for PD withdrawal, and multiple regression analysis showed that the presence of peritonitis (p=0.0063) and low-density lipoprotein cholesterol (LDL-C) levels (p=0.0087) were significant factors for PD duration. Peritonitis incidence was 0.077 times per patient per year, and multivariate analysis identified PD duration (p=0.0009) and LDL-C levels (p=0.0054) as independent risk factors for peritonitis. CONCLUSION: The findings of this study revealed that assessment of the nutritional status of the patient and prevention of peritonitis are important for continuation of PD. PD is a safe treatment option that can maintain the quality of life in elderly patients. In a rapidly aging society, the need for PD-based medical care is expected to increase.

Kinetics of carnitine concentration after switching from oral administration to intravenous injection in hemodialysis patients.

Carnitine has high dialyzability and is often deficient in dialysis patients. This deficiency is treated by either intravenous (IV) or oral supplementation of carnitine. In this study, the mode of carnitine administration was changed from oral to IV in 17 hemodialysis (HD) patients, and the treatment was discontinued after 1 year. We found that the levels of total carnitine (TC), free-carnitine (FC), and acyl-carnitine (AC) significantly increased after 3 months of switching to IV administration (p < .05). After discontinuation of carnitine administration, the TC, FC, and AC levels decreased before dialysis. The average FC value was maintained at the normal levels until 9 months, but fell below the normal values when measured at the 12th month of discontinuation. In conclusion, carnitine was maintained at significantly high levels despite the smaller dose by IV infusion as compared with that by oral administration. We therefore suggest that our results be considered while determining both the carnitine administration route and the administration period in dialysis patients under clinical settings.

Comparison of pain and efficacy of darbepoetin alfa and epoetin Beta pegol treatment in patients receiving peritoneal dialysis.

BACKGROUND: Sustained erythropoiesis-stimulating agents (ESAs) have recently been identified as the standard therapeutic agent for anemia in patients undergoing peritoneal dialysis (PD). However, few reports have compared pain between various types of sustained ESAs or between administration routes. Furthermore, the change ratio of the dose of sustained ESAs reportedly ranges from 0.8 to 1.3. In the present study, to compare darbepoetin alfa and epoetin beta pegol (a continuous erythropoietin receptor activator [CERA]), we examined the dolorific differences between administration routes and the effect on anemia by using a chjange ratio of 0.8 with darbepoetin alfa in patients with renal anemia undergoing PD. SUBJECTS AND METHOD: We randomly assigned 20 patients with stable hemoglobin levels undergoing PD to either a darbepoetin alfa therapy group or a CERA therapy group. Based on a previous report, the change ratio of the CERA group from CERA to darbepoetin alfa therapy was assumed to be 0.8, and therapy was crossed-over to darbepoetin alfa again 2 months later. The dolorific evaluation (pain measurement) used both a face scale and a visual analogue scale. We compared the agents as well as administration routes with respect to pain. We also measured variables related to anemia and iron metabolism. RESULTS: The change ratio of the CERA group at the start of the study was 0.821. On resumption of darbepoetin alfa therapy 2 months later, the doses of darbepoetin alfa increased. The darbepoetin alfa group showed a stronger tendency for pain, although the difference was not significant. In contrast, subcutaneous administration in the CERA group showed significant pain just after injection. The CERA group, however, showed a significant decrease in hemoglobin levels after 2 months of treatment (p=0.0489). No significant change was found in the hematocrit or the reticulocyte count. There were no significant differences in iron metabolism, as shown by serum iron levels and total iron-binding capacity, in either group. However, serum ferritin levels showed a tendency to decrease in the darbepoetin alfa group. CONCLUSION: No significant difference in pain was found between darbepoetin alfa and CERA therapies, but a significant difference in pain was noted between administration routes, just after injection, in the CERA group. The results also suggest that a change ratio of 0.8 from darbepoetin alfa to CERA is low for managing anemia.

Effects of alogliptin in chronic kidney disease patients with type 2 diabetes.

OBJECTIVE: Diabetes is a major risk factor for chronic kidney disease (CKD). In this study, we examined the effects of alogliptin on blood glucose control and the renal function in type 2 diabetes CKD patients. METHODS: We recruited 36 CKD patients with type 2 diabetes. The patients were followed up for six months after adding alogliptin. Blood biochemical, urine test and office BP values were obtained six months before and after the start of treatment. RESULTS: The mean HbA1c value was not decreased; however, the 1,5-AG values tended to improve (p=0.1023). The mean eGFR was unchanged. There were no significant changes in the patients with an eGFR of 60 mL/min/1.73 m2 or more (25 patients) or in the patients with an eGFR less than 60 mL/min/1.73 m2 (11 patients). A total of 15 patients were identified to have rapidly declining diabetic nephropathy, with an annual reduction in eGFR of 5 mL/min/1.73 m2 or more. The slope of the regression line for eGFR (-1.296 before starting treatment with alogliptin) was positive, increasing up to 0.08786. The eGFR values appeared to stop decreasing and positively reversed. The urinary albumin-to-creatinine ratio exhibited a downward trend. The effect on the renal function was independent of the levels of blood sugar, blood pressure and lipids. CONCLUSION: We examined the ability of alogliptin to maintain the renal function in patients with CKD complicated by type 2 diabetes. Our study suggests that alogliptin can be safely administered in patients with CKD. However, although we expected alogliptin to demonstrate renal protective effects, were unable to detect statistically significant differences. One reason for this finding is that there are few registered cases.

Comparison of once daily versus twice daily olmesartan in patients with chronic kidney disease.

BACKGROUND: The effects of olmesartan (OLM) on blood pressure and kidney function in Japanese patients with chronic kidney disease (CKD) were compared between 20 mg twice daily (BID) and 40 mg once daily (QD) treatments. METHODS: The subjects were Japanese CKD patients with concurrent hypertension who had been treated with OLM 20 mg BID for at least 3 months on an outpatient basis (n=39). After a change in the treatment regimen to 40 mg OLM QD (after breakfast), blood pressure (BP) (n=39), morning home BP (n=13), estimated glomerular filtration rate (n=39), and urinary albumin-to-creatinine ratio (n=17) were monitored for 2 months. RESULTS: No significant change in office (mean ± standard deviation [SD] [mmHg], 143.9 ± 18.8/75.7 ± 12.0 to 141.6 ± 16.1/74.7 ± 11.7, not significant [ns]) or early morning home (mean ± SD [mmHg], 133.8 ± 15.9/71.2 ± 11.5 to 133.8 ± 13.9/74.5 ± 10.5, ns) BP was observed 2 months after the change in dose. The estimated glomerular filtration rate increased significantly (mean ± SD, 49.0 ± 28.0 to 51.8 ± 27.0, P<0.05), whereas urinary albumin-to-creatinine ratio did not change significantly (mean ± SD, 0.551 ± 0.445 to 0.364 ± 0.5194, ns). CONCLUSION: High-dose OLM administered BID and QD had similar effects on outpatient and early morning home BP in CKD patients, suggesting that the BID regimen can be safely changed to a QD regimen. For CKD patients with hypertension requiring continuous long-term treatment, the possibility that the QD regimen might bring a greater therapeutic effect was suggested. However, recognizing the best blood pressure control level for a CKD patient is still a matter of debate, and should ideally be personalized.