Development of a New Adjustable Compression Garment (McBoooon) Made of Non-Stretch Self-Adhesive Fabric.

Objectives: To assess the physical features and compression characteristics of a newly developed adjustable compression garment, McBoooon (Mc). Methods: Twelve healthy volunteers were recruited to assess the compression characteristics. The interface pressure (IP) was continuously measured to calculate the static (SSI) and dynamic stiffness indices (DSI). Additionally, the peak flow velocity (PV) of the popliteal vein during ankle dorsiflexion was measured using ultrasonography. Each parameter was compared between ASHIKA stockings (AS), Mc applied at the same resting pressure as AS (Mc1), and Mc applied at a resting pressure approximately twice that of Mc1 (Mc2). Results: SSI and DSI were significantly different, increasing in the order AS < Mc1 < Mc2 (p <0.01). Although the PV was significantly higher in the compression group than in the control group (p <0.05), no significant differences were found among the three groups. Conclusion: The physical features and compression characteristics of Mc were clarified. The high stiffness of this garment improves the adherence to compression therapy and contributes to the treatment of chronic venous insufficiency.

Predicting reprogramming-related gene expression from cell morphology in human induced pluripotent stem cells.

Purification is essential before differentiating human induced pluripotent stem cells (hiPSCs) into cells that fully express particular differentiation marker genes. High-quality iPSC clones are typically purified through gene expression profiling or visual inspection of the cell morphology; however, the relationship between the two methods remains unclear. We investigated the relationship between gene expression levels and morphology by analyzing live-cell, phase-contrast images and mRNA profiles collected during the purification process. We employed these data and an unsupervised image feature extraction method to build a model that predicts gene expression levels from morphology. As a benchmark, it was confirmed that the method can predict the gene expression levels from tissue images for cancer genes, performing as well as state-of-the-art methods. We then applied the method to iPSCs and identified two genes that are well predicted from cell morphology. Although strong batch (or possibly donor) effects resulting from the reprogramming process preclude the ability to use the same model to predict across batches, prediction within a reprogramming batch is sufficiently robust to provide a practical approach for estimating expression levels of a few genes and monitoring the purification process.

Thermal adaptation of acetic acid bacteria for practical high-temperature vinegar fermentation.

Thermotolerant microorganisms are useful for high-temperature fermentation. Several thermally adapted strains were previously obtained from Acetobacter pasteurianus in a nutrient-rich culture medium, while these adapted strains could not grow well at high temperature in the nutrient-poor practical culture medium, "rice moromi." In this study, A. pasteurianus K-1034 originally capable of performing acetic acid fermentation in rice moromi was thermally adapted by experimental evolution using a "pseudo" rice moromi culture. The adapted strains thus obtained were confirmed to grow well in such the nutrient-poor media in flask or jar-fermentor culture up to 40 or 39 °C; the mutation sites of the strains were also determined. The high-temperature fermentation ability was also shown to be comparable with a low-nutrient adapted strain previously obtained. Using the practical fermentation system, "Acetofermenter," acetic acid production was compared in the moromi culture; the results showed that the adapted strains efficiently perform practical vinegar production under high-temperature conditions.

The haemodynamic causes of skin changes in limbs with primary varicose veins.

OBJECTIVES: To investigate the haemodynamic causes of skin changes in limbs with primary varicose veins, which were assessed with air plethysmography. METHODS: Five hundred seventeen consecutive patients with axial reflux in the great saphenous vein (varicose vein group) and 248 normal subjects (normal group) were investigated. Varicose vein group patients were divided into two groups according to whether they did (C4-6) or did not (C2-3) have skin changes. Several parameters obtained using air plethysmography were compared among the normal group, C2-3 and C4-6 patients. RESULTS: Although there was no significant difference in the regurgitation index to quantify venous reflux in C2-3 and C4-6 patients, the maximum arterial inflow rate increased (normal group < C2-3 < C4-6), even in limbs with a small amount of venous reflux. CONCLUSIONS: This study suggests that it is not essential to increase the venous reflux rate in skin change development; rather, it is based on various pathophysiological conditions that increase the arterial inflow rate.

Accuracy of Venous Filling Index on Standing (VFIst) and Pure Regurgitation Index (PRI), a Novel Index Obtained by Air Plethysmography, for Detecting Venous Reflux.

OBJECTIVE: To evaluate the accuracy of venous filling index on standing (VFIst) and a new index named pure regurgitation index (PRI), obtained by air plethysmography, for detecting venous reflux. MATERIALS AND METHODS: One hundred and sixty-one healthy subjects (161 limbs) and 180 varicose vein patients (180 limbs) were investigated. All subjects underwent duplex ultrasonography for verifying venous reflux and air plethysmography to obtain hemodynamic parameters such as VFIst, VFI in the supine position (VFIsu), and the maximum arterial inflow rate. To evaluate the accuracy of VFIst and PRI (= (VFIst - VFIsu)/body mass index), receiver operating characteristics curves were created. RESULTS: The optimal cut-off value, sensitivity, specificity, and area under the curve, obtained from analyzing the receiver operating characteristics curves, of VFIst vs. PRI were 2.058 mL/s vs. 0.059 mL · m(2)/s · kg, 93.3% vs. 90.3%, 88.8% vs. 91.3%, and 0.954 vs. 0.964, respectively. CONCLUSIONS: This study indicates that while both VFIst and PRI are highly accurate indicators of venous reflux, PRI, which is not affected by the arterial inflow rate and body mass index, is slightly superior to VFIst, especially in subjects with greater body mass index.

Quantitative study on appearance of microvessels in spectral endoscopic imaging.

Increase in abnormal microvessels in the superficial mucosa is often relevant to diagnostic findings of neoplasia in digestive endoscopy; hence, observation of superficial vasculature is crucial for cancer diagnosis. To enhance the appearance of such vessels, several spectral endoscopic imaging techniques have been developed, such as narrow-band imaging and blue laser imaging. Both techniques exploit narrow-band blue light for the enhancement. The emergence of such spectral imaging techniques has increased the importance of understanding the relation of the light wavelength to the appearance of superficial vasculature, and thus a new method is desired for quantitative analysis of vessel visibility in relation to the actual structure in the tissue. Here, we developed microvessel-simulating phantoms that allowed quantitative evaluation of the appearance of 15-µm-thick vessels. We investigated the relation between the vascular contrast and light wavelength by the phantom measurements and also verified it in experiments with swine, where the endoscopically observed vascular contrast was investigated together with its real vascular depth and diameter obtained by microscopic observation of fluorescence-labeled vessels. Our study indicates that changing the spectral property even in the wavelength range of blue light may allow selective enhancement of the vascular depth for clinical use.

Relationship between Arterial Inflow Rate and Venous Filling Index of the Lower Extremities Assessed by Air Plethysmography in Subjects with or without Axial Reflux in the Great Saphenous Vein.

OBJECTIVE: To evaluate the relationship between arterial inflow rate (AIR) and venous filling index (VFI) in limbs with or without varicose veins, assessed by air plethysmography (APG). MATERIALS AND METHODS: A total of 142 patients (142 limbs) visiting our clinic with leg complaints, but without arterial and venous disease, were defined as the normal group (NG), and 65 patients (65 limbs) with leg varices were defined as the varicose vein group (VG). Both groups underwent duplex ultrasonography and APG to identify venous reflux and measure hemodynamic parameters, respectively. Examinations were performed at the first visit in the NG and before and one month after treatment in the VG. RESULTS: A strong correlation between resting AIR and VFI was found in the NG (r = 0.72) and postoperative VG (r = 0.71). Twenty-two and three limbs in the NG and postoperative VG, respectively, had a VFI over 2.0 mL/s because of the high AIR. In the VG, AIR tended to decrease after treatment (P >0.01). CONCLUSIONS: High leg AIR lead to high VFI measured by APG. AIR and VFI should be measured at the same session to assess venous hemodynamic changes after varicose vein treatment when residual venous reflux cannot be diagnosed with duplex ultrasonography.

Separation of multiunit signals by independent component analysis in complex-valued time-frequency domain.

Multiunit recording with a multi-electrode in the brain has been widely used in neuroscience studies. After the data recording, neuronal spikes should be sorted according to spike waveforms. For the spike sorting, independent component analysis (ICA) has recently been used because ICA potentially solves the problem to separate even overlapped multiple neuronal spikes into the single. However, we found that multiunit signals are recorded in each electrode channel with channel-specific delay. This situation does not satisfy the instantaneous mixture condition prerequisite for most of ICA algorithms. Actually, this delayed mixture situation was shown to degrade the performance of an ordinary ICA. In this study, in order to overcome this problem, complex-valued processing in the time-frequency domain is applied to multiunit signals by the wavelet transform. In the space spanned by the wavelet coefficients, the condition of instantaneous mixture is almost fulfilled. By application to a synthetic multiunit signal, the ICA algorithm extended to complex-valued signals makes much improvement in spike sorting performance so that even overlapped multiple spikes are successfully separated. Taken together, the complex-valued method could be a powerful tool for spike sorting.

Multi-neuron action potentials recorded with tetrode are not instantaneous mixtures of single neuronal action potentials.

Multiunit recording with multi-site electrodes in the brain has been widely used in neuroscience studies. After the data recording, neuronal spikes should be sorted according to the pattern of spike waveforms. For the spike sorting, independent component analysis (ICA) has recently been used because ICA has potential for resolving the problem to separate the overlapped multiple neuronal spikes. However the performance of spike sorting by using ICA has not been examined in detail. In this study, we quantitatively evaluate the performance of ICA-based spike sorting method by using simulated multiunit signals. The simulated multiunit signal is constructed by compositing real extracellular action potentials recorded from guinea-pig brain. It is found that the spike sorting by using ICA hardly avoids significant false positive and negative errors due to the cross-talk noise contamination on the separated signals. The cross-talk occurs when the multiunit signal of each recording channel have significant time difference; this situation does not satisfy the assumption of instantaneous source mixture for the major ICA algorithms. Since the channel delay problem is hardly resolved, an ICA algorithm which does not require the instantaneous source mixing assumption would be appropriate for use of spike sorting.