In the present study, we used a large-scale integration (LSI)-based amperometric sensor array system, designated Bio-LSI, to image dopamine release from three-dimensional (3D)-cultured PC12 cells ...(PC12 spheroids). The Bio-LSI device consists of 400 sensor electrodes with a pitch of 250 μm for rapid electrochemical imaging of large areas. PC12 spheroids were stimulated with K+ to release dopamine. Poststimulation dopamine release from the PC12 spheroids was electrochemically imaged using the Bio-LSI device. Bio-LSI clearly showed the effects of the dopaminergic drugs l-3,4-dihydroxyphenylalanine (l-DOPA) and reserpine on K+-stimulated dopamine release from PC12 spheroids. Our results demonstrate that dopamine release from PC12 spheroids can be monitored using the device, suggesting that the Bio-LSI is a promising tool for use in evaluating 3D-cultured dopaminergic cells and the effects of dopaminergic drugs. To the best of our knowledge, this report is the first to describe electrochemical imaging of dopamine release by PC12 spheroids using LSI-based amperometric sensors.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been garnered increasing for its rapid worldwide spread. Each country had implemented city-wide lockdowns and immigration regulations ...to prevent the spread of the infection, resulting in severe economic consequences. Materials and technologies that monitor environmental conditions and wirelessly communicate such information to people are thus gaining considerable attention as a countermeasure. This study investigated the dynamic characteristics of batteryless magnetostrictive alloys for energy harvesting to detect human coronavirus 229E (HCoV-229E). Light and thin magnetostrictive Fe–Co/Ni clad plate with rectification, direct current (DC) voltage storage capacitor, and wireless information transmission circuits were developed for this purpose. The power consumption was reduced by improving the energy storage circuit, and the magnetostrictive clad plate under bending vibration stored a DC voltage of 1.9 V and wirelessly transmitted a signal to a personal computer once every 5 min and 10 s under bias magnetic fields of 0 and 10 mT, respectively. Then, on the clad plate surface, a novel CD13 biorecognition layer was immobilized using a self-assembled monolayer of –COOH groups, thus forming an amide bond with –NH2 groups for the detection of HCoV-229E. A bending vibration test demonstrated the resonance frequency changes because of HCoV-229E binding. The fluorescence signal demonstrated that HCoV-229E could be successfully detected. Thus, because HCoV-229E changed the dynamic characteristics of this plate, the CD13-modified magnetostrictive clad plate could detect HCoV-229E from the interval of wireless communication time. Therefore, a monitoring system that transmits/detects the presence of human coronavirus without batteries will be realized soon.
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•Information was transmitted by a Fe–Co/Ni clad plate under bending vibration.•We immobilized the protein CD13 onto the surface of the clad plate.•The capture of human coronavirus 229E was confirmed using the clad plate under vibration.•Our energy harvesting device, which does not require batteries, could detect the coronavirus.
This paper reports a novel approach for the simple detection of cell apoptosis using an electrochemical technique. This method uses caspase-3 activity as an indicator of apoptosis. Caspase-3 activity ...was detected with differential plus voltammetry (DPV) as an alternative to conventional spectrometry. In this method, p-nitroaniline (pNA) released from Asp-Glu-Val-Asp-pNA by caspase-3 enzyme reaction was measured with DPV by using a glassy carbon electrode. Using this method, we successfully detected cell apoptosis occurring inside living HepG2 cells without the need for a cell lysis step. This method provides an easy assay procedure and, more importantly, allows a live cell apoptosis detection format. This novel electrochemical apoptosis assay using living cells instead of typically used cell lysates will expand the applicable range of the apoptosis assay to include cell activity assays for drug discovery and cell transplantation medicine.
Multiplexed bioimaging systems have triggered the development of effective assays, contributing new biological information. Although electrochemical imaging is beneficial for quantitative analysis in ...real time, monitoring multiple cell functions is difficult. We have developed a novel electrochemical imaging system, herein, using a large-scale integration (LSI)-based amperometric device for detecting multiple biomolecules simultaneously. This system is designated as an electrochemicolor imaging system in which the current signals from two different types of biomolecules are depicted as a multicolor electrochemical image. The mode-selectable function of the 400-electrode device enables the imaging system and two different potentials can be independently applied to the selected electrodes. The imaging system is successfully applied for detecting multiple cell functions of the embryonic stem (ES) cell and the rat pheochromocytoma (PC12) cell aggregates. To the best of our knowledge, this is the first time that a real-time electrochemical mapping technique for multiple electroactive species, simultaneously, has been reported. The imaging system is a promising bioanalytical method for exploring complex biological phenomena.
This study describes several essential factors for direct and effective lactic acid production from food wastes by
Lactobacillus manihotivorans LMG18011, and optimum conditions for simultaneous ...saccharification and fermentation using soluble starch and food wastes as substrates. The productivity was found to be affected by three factors: (1) initial pH, which influenced amylase production for saccharification of starch, (2) culture pH control which influenced selective production of
l(+)-lactic acid, and (3) manganese concentration in medium which improved in production rate and yield of lactic acid. The optimum initial pH was 5.0–5.5, and the fermentation pH for the direct and effective fermentation from starchy substrate was 5.0 based on the yield of
l(+)-lactic acid. Under these conditions, 19.5
g
l(+)-lactic acid was produced from 200
g food wastes by
L. manihotivorans LMG18011. Furthermore, the addition of manganese stimulated the direct fermentation significantly, and enabled complete bioconversion within 100
h.
Recently, we reported that patients with depression have theory of mind (ToM) deficit during remission from acute episodes. ToM deficit means difficulty in social adjustment and thus may indicate a ...poorer prognosis.
We evaluated ToM ability of 50 patients during remission from major depressive episodes. The patients were followed for 1 year and their outcome observed.
After 1 year, patients who had ToM deficit in a second order false question relapsed significantly more frequently as compared with patients who did not have a deficit (Fisher's exact test
p
<
0.0001; relative risk (RR)
=
8.105; CI 2.020, 32.524). Significant differences were shown in scores of the Global Assessment of Functioning Scale (
p
<
0.0001) between the two groups.
Patients with ToM deficit in second order false belief during remission may be a high risk group for recurrence and lower social function 1 year after recovering from a major depressive episode.
Objectives We performed indocyanine green angiography (ICGA) in patients with peripheral arterial disease (PAD), and established a method for the quantitative measurement of appropriate parameters to ...assess peripheral perfusion and the applicability of ICGA tests. Methods Twenty-one patients with PAD underwent revascularization procedures with pre- and postinterventional ICGA tests. The ICGA parameters, which included the magnitude of intensity of indocyanine green, the time to maximum intensity, and the time from fluorescence onset to half the maximum intensity (T1/2 ) were compared with the ankle-brachial pressure index, toe -brachial pressure index, and toe pressure. We evaluated these parameters for regions of interest (ROIs). Results T1/2 was the strongest parameter among all parameters of the ICGA tests. ROI 3, which included the distal region of the first metatarsal bone, correlated more significantly with the traditional measurements than the other ROIs. A value of T1/2 >20 seconds for ROI 3 was significantly correlated with a toe pressure of <50 mmHg (sensitivity: 0.77, specificity: 0.80). Conclusions ICGA can be used to assess peripheral tissue perfusion. By measuring the value of T1/2 in ROI 3, ICGA tests can be used to evaluate the outcomes of revascularization procedures.
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