Simultaneous Material and Chemical Recycling of Waste PET/PE Multi-layer Films under Hydrothermal Conditions.

Multi-layer plastic films are widely used in various fields especially for packaging, but due to complex composition, it is very difficult to recover single-material polymers or high-purity monomers from them after usage. In this study, we proposed a hydrothermal process for recycling PET/PE (PET: Polyethylene terephthalate; PE: Polyethylene) films. PET can be hydrolyzed to monomers of terephthalic acid (TPA) and ethylene glycol (EG). Using a hydrothermal system equipped with two filters, PE, TPA, and EG were collected separately, indicating the simultaneous material and chemical recycling of PET/PE films was firstly achieved. At 300 °C and 10 MPa for 60 min, PET conversion reached around 100%, and TPA yield of 83.0% was obtained with a high TPA purity of 96.1%. In addition, the effect of the holding time on PET conversion, TPA yield, EG yield, and TPA purity was studied. This research opened up a new and sustainable pathway to recycle multi-layer plastic films in both lab and industry.

Prognostic impact of pretreatment T790M mutation on outcomes for patients with resected, EGFR-mutated, non-small cell lung cancer.

BACKGROUND: Many previous studies have demonstrated that minor-frequency pretreatment T790M mutation (preT790M) could be detected by ultrasensitive methods in a considerable number of treatment-naïve, epidermal growth factor receptor (EGFR)-mutated, non-small cell lung cancer (NSCLC) cases. However, the impact of preT790M in resected cases on prognosis remains unclear. METHODS: We previously reported that preT790M could be detected in 298 (79.9%) of 373 surgically resected, EGFR-mutated NSCLC patients. Therefore, we investigated the impact of preT790M on recurrence-free survival (RFS) and overall survival (OS) in this cohort by multivariate analysis. All patients were enrolled from July 2012 to December 2013, with follow-up until November 30, 2017. RESULTS: The median follow-up time was 48.6 months. Using a cutoff value of the median preT790M allele frequency, the high-preT790M group (n = 151) had significantly shorter RFS (hazard ratio [HR] = 1.51, 95% confidence interval [CI]: 1.01-2.25, P = 0.045) and a tendency for a shorter OS (HR = 1.87, 95% CI: 0.99-3.55, P = 0.055) than the low-preT790M group (n = 222). On multivariate analysis, higher preT790M was independently associated with shorter RFS (high vs low, HR = 1.56, 95% CI: 1.03-2.36, P = 0.035), irrespective of advanced stage, older age, and male sex, and was also associated with shorter OS (high vs low, HR = 2.16, 95% CI: 1.11-4.20, P = 0.024) irrespective of advanced stage, older age, EGFR mutation subtype, and history of adjuvant chemotherapy. CONCLUSIONS: Minor-frequency, especially high-abundance of, preT790M was an independent factor associated with a poor prognosis in patients with surgically resected, EGFR-mutated NSCLC.

Synthesis of unused-wood-derived C-Fe-N catalysts for oxygen reduction reaction by heteroatom doping during hydrothermal carbonization and subsequent carbonization in nitrogen atmosphere.

There is an urgent need to develop renewable sources of energy and use existing resources in an efficient manner. In this study, in order to improve the utilization of unused biomass and develop green processes and sustainable technologies for energy production and storage, unused Douglas fir sawdust (SD) was transformed into catalysts for the oxygen reduction reaction. Fe and N were doped into SD during hydrothermal carbonization, and the N- and Fe-doped wood-derived carbon (Fe/N/SD) was carbonized in a nitrogen atmosphere. After the catalyst had been calcined at 800°C, its showed the highest current density (-5.86 mAcm-2 at 0.5 V versus reversible hydrogen electrode or RHE) and Eonset value (0.913 V versus RHE). Furthermore, its current density was higher than that of Pt/C (20 wt% Pt) (-5.66 mA cm-2 @0.5 V versus RHE). Finally, after 50 000 s, the current density of sample Fe/N/SD (2 : 10 : 10) remained at 79.3% of the initial value. Thus, the synthesized catalysts, which can be produced readily at a low cost, are suitable for use in various types of energy generation and storage devices, such as fuel cells and air batteries. This article is part of the theme issue 'Bio-derived and bioinspired sustainable advanced materials for emerging technologies (part 2)'.

Increased hydrostatic pressure induces nuclear translocation of DAF-16/FOXO in C. elegans.

Mechanical stimulation is well known to be important for maintaining tissue and organ homeostasis. Here, we found that hydrostatic pressure induced nuclear translocation of a forkhead box O (FOXO) transcription factor DAF-16, in C. elegans within minutes, whereas the removal of this pressure resulted in immediate export of DAF-16 to the cytoplasm. We also monitored DAF-16-dependent transcriptional changes by exposure to 1 MPa pressure for 5 min, and found significant changes in collagen and other genes in a DAF-16 dependent manner. Lifespan was markedly prolonged with exposure to cyclic pressure treatment (1 MPa once a day for 5 min from L1 larvae until death). Furthermore, age-dependent decline in locomotor activity was suppressed by the treatment. In contrast, the nuclear translocation of the yes-associated protein YAP-1 was not induced under the same pressure conditions. Thus, moderate hydrostatic pressure improves ageing progression through activation of DAF-16/FOXO in C. elegans.

Isolation and molecular analysis of circulating tumor cells from lung cancer patients using a microfluidic chip type cell sorter.

Circulating tumor cells (CTCs) are a tumor-derived material utilized for liquid-based biopsy; however, capturing rare CTCs for further molecular analysis remains technically challenging, especially in non-small-cell lung cancer. Here, we report the results of a clinical evaluation of On-chip Sort, a disposable microfluidic chip-based cell sorter, for capture and molecular analysis of CTCs from patients with lung adenocarcinoma. Peripheral blood was collected from 30 metastatic lung adenocarcinoma patients to enumerate CTCs using both On-chip Sort and CellSearch in a blind manner. Captured cells by On-chip Sort were subjected to further molecular analysis. Peripheral blood samples were also used for detection of EGFR mutations in plasma using droplet digital PCR. Significantly more CTCs were detected by On-chip Sort (22/30; median 5; range, 0-18 cells/5 mL blood) than by CellSearch (9/30; median, 0; range, 0-12 cells/7.5 mL) (P < 0.01). Thirteen of 30 patients who had a negative CTC count by CellSearch had a positive CTC count by On-chip Sort. EGFR mutations in CTCs captured by On-chip Sort were observed in 40.0% (8/20) of patients with EGFR-mutated primary tumor. EGFR mutations were often observed in 53.3% (8/15) of patients detected in plasma DNA. Expressions of EGFR and vimentin protein on CTCs were also successfully assessed using On-chip Sort. These results suggest that On-chip Sort is an efficient method to detect and capture rare CTCs from patients with lung adenocarcinoma that are undetectable with CellSearch. Mutation detection using isolated CTCs remains to be further tackled (UMIN000012488).

Sensitive cytometry based system for enumeration, capture and analysis of gene mutations of circulating tumor cells.

Methods for the enumeration and molecular characterization of circulating tumor cells (CTC) have been actively investigated. However, such methods are still technically challenging. We have developed a novel epithelial cell adhesion molecule independent CTC enumeration system integrated with a sorting system using a microfluidics chip. We compared the number of CTC detected using our system with those detected using the CellSearch system in 46 patients with various cancers. We also evaluated epidermal growth factor receptor (EGFR) and PIK3CA mutations of captured CTC in a study of 4 lung cancer and 4 breast cancer patients. The percentage of samples with detected CTC was significantly higher with our system (65.2%) than with CellSearch (28.3%). The number of detected CTC per patient using our system was statistically higher than that using CellSearch (median 5, 0; P = 0.000172, Wilcoxon test). In the mutation analysis study, the number of detected CTC per patient was low (median for lung, 4.5; median for breast, 5.5); however, it was easy to detect EGFR and PIK3CA mutations in the CTC of 2 lung and 1 breast cancer patient, respectively, using a commercially available kit. Our system is more sensitive than CellSearch in CTC enumeration of various cancers and is also capable of detecting EGFR and PIK3CA mutations in the CTC of lung and breast cancer patients, respectively.

Peroxisome proliferator-activated receptor γ agonist efatutazone impairs transforming growth factor ß2-induced motility of epidermal growth factor receptor tyrosine kinase inhibitor-resistant lung cancer cells.

Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKI) are effective for non-small cell lung cancers (NSCLC) with EGFR-activating mutations. However, most responders develop resistance. Efatutazone, a novel peroxisome proliferator-activated receptor gamma (PPARγ) agonist, is currently under clinical evaluation; it has antiproliferative effects and induces cellular morphological changes and differentiation. The present study investigated the effects of efatutazone in EGFR-TKI-resistant NSCLC cells, while focusing on cell motility. The PC-9-derived NSCLC cell lines PC-9ER and PC-9ZD, resistant to EGFR-TKI due to v-crk avian sarcoma virus CT10 oncogene homolog-like (CRKL) amplification-induced phosphatidylinositol 3-kinase (PI3K)/v-akt murine thymoma viral oncogene homolog (AKT) activation and an EGFR T790M mutation, respectively, were used. These cells exhibit enhanced cell motility due to transforming growth factor ß (TGF-ß)/Smad2 family member 2 (Smad2) pathway activation. Efatutazone had no growth-inhibitory effect on the tested cells but inhibited the motility of EGFR-TKI-resistant cells in wound closure and transwell assays. Efatutazone plus erlotinib treatment provided greater inhibition of PC-9ER cell migration than efatutazone or erlotinib alone. Efatutazone suppressed increased TGF-ß2 secretion from both cell lines (shown by ELISA) and downregulation of TGF-ß2 transcription (observed by quantitative RT-PCR). Immunoblot analysis and luciferase assays revealed that efatutazone suppressed Smad2 phosphorylation and its transcriptional activity. These results suggest that efatutazone inhibits cell motility by antagonizing the TGF-ß/Smad2 pathway and effectively prevents metastasis in NSCLC patients with acquired resistance to EGFR-TKI regardless of the resistance mechanism.

A novel flow cytometry-based cell capture platform for the detection, capture and molecular characterization of rare tumor cells in blood.

BACKGROUND: Personalized cancer treatment relies on the accurate detection of actionable genomic aberrations in tumor cells. Circulating tumor cells (CTCs) could provide an alternative genetic resource for diagnosis; however, the technical difficulties in isolating and analyzing rare CTCs have limited progress to date. In this preclinical study, we aimed to develop an improved capture system for molecular characterization of CTCs based on a novel cell sorting technology. METHODS: We developed a cell capture platform using On-chip Sort (On-Chip Biotechnologies), a novel bench-top cell sorter equipped with a disposable microfluidic chip. Spike-in experiments comprising a series of lung cancer cell lines with varying epithelial cell adhesion molecule (EpCAM) expression levels were conducted to assess the capture and purification efficiency of the platform. Samples were negatively enriched using anti-CD45-coated magnetic beads to remove white blood cells, followed by sample fixation and labeling. The enriched and labeled samples were then sorted by On-chip Sort based on cytokeratin, vimentin, and CD45 expression. Captured cells were immediately subjected to whole genome amplification followed by mutation analysis using deep targeted sequencing, and copy number analysis using quantitative polymerase chain reaction (qPCR). RESULTS: Spike-in experiments revealed an excellent overall mean capture rate of 70.9%. A 100% success rate in the detection of EGFR, KRAS and BRAF mutations from captured cells was achieved using pyrosequencing and deep sequencing. The mutant variant detection rates were markedly higher than those obtained with the CellSearch profile kit. qPCR analysis of amplified DNA demonstrated reproducible detection of copy number changes of the EGFR in captured tumor cells. CONCLUSIONS: Using a novel cell sorter, we established an efficient and convenient platform for the capture of CTCs. Results of a proof-of-principle preclinical study indicated that this platform has potential for the molecular characterization of captured CTCs from patients.

Multicolor detection of rare tumor cells in blood using a novel flow cytometry-based system.

The presence and number of circulating tumor cells (CTCs) in the blood of patients with solid tumors are predictive of their clinical outcomes. To date, the CellSearch system is the only US Food and Drug Administration-approved CTC enumeration system for advanced breast, prostate, and colon cancers. However, sensitivity issues due to epithelial cellular adhesion molecule (EpCAM)-based enrichment and limited capability for subsequent molecular analysis must be addressed before CTCs can be used as predictive markers in the clinical setting. We have developed a multicolor CTC detection system using cross-contamination-free flow cytometry, which permits the enumeration and characterization of CTCs for multiple molecular analyses. Tumor cell lines with different expression levels of EpCAM were spiked into peripheral blood obtained from healthy donors. Spike-in samples were negatively enriched using anti-CD45-coated magnetic beads to remove white blood cells, and this was followed by fixation and labeling with CD45-Alexa Fluor 700, EpCAM-phycoerythrin, cytokeratin (CK)-fluorescein isothiocyanate antibodies, and/or 7-aminoactinomycin D for nuclei staining. Excellent detection (slope = 0.760-0.888) and a linear performance (R(2) = 0.994-0.998) were noted between the observed and expected numbers of tumor cells, independent of EpCAM expression. The detection rate was markedly higher than that obtained using the CellSearch system, suggesting the superior sensitivity of our system in detecting EpCAM- tumor cells. Additionally, the incorporation of an epithelial-mesenchymal transition (EMT) marker allowed us to detect EpCAM-/CK- cells and EMT-induced tumor cells. Taken together, our multicolor CTC detection system may be highly efficient in detecting previously unrecognized populations of CTCs.

Effects of cytochalasin D on relaxation process of skinned taenia cecum and carotid artery from guinea pig.

Actin linked regulatory mechanisms are known to contribute contraction/relaxation in smooth muscle. In order to clarify whether modulation of polymerization/depolymerization of actin filaments affects relaxation process, we examined the effects of cytochalasin D on relaxation process by Ca2+ removal after Ca2+-induced contraction of ß-escin skinned (cell membrane permeabilized) taenia cecum and carotid artery preparations from guinea pigs. Cytochalasin D, an inhibitor of actin polymerization, significantly suppressed the force during relaxation both in skinned taenia cecum and carotid artery. The data fitting analysis of the relaxation processes indicates that cytochalasin D accelerates slow (latch-like) bridge dissociation. Cytochalasin D seems to directly disrupts actin filament organization or its length, resulting in modulation of actin filament structure that prevents myosin binding.

Long-term follow-up results from KEYNOTE-041: Phase 1b study of pembrolizumab in Japanese patients with advanced melanoma.

Pembrolizumab demonstrated an acceptable safety profile and promising antitumor activity in Japanese patients with advanced melanoma in the phase 1b KEYNOTE-041 (Study of Pembrolizumab [MK-3475] in Participants With Advanced Melanoma) trial. To evaluate the long-term efficacy and safety of pembrolizumab in Japanese patients with advanced melanoma in KEYNOTE-041. The current analysis reports results of additional follow-up of approximately 12 months since the initial analysis. Eligible patients had locally advanced (unresectable stage III) or metastatic (stage IV) melanoma not amenable to local therapy and had received two or fewer prior systemic therapies. Pembrolizumab 2 mg/kg was given every 3 weeks for up to 2 years or until confirmed progression or unacceptable toxicity. Primary end points included safety, tolerability, and overall response rate (ORR) per Response Evaluation Criteria in Solid Tumors version 1.1 by independent central review. The data cutoff for this analysis was August 30, 2017. Forty-two patients were followed up for a median of 22.3 months (range, 2.63-30.82 months). The ORR was 24.3% (nine of 37 evaluable patients [95% confidence interval (CI), 11.8%-41.2%]). Two patients with partial response at the time of the initial analysis achieved complete response. The median overall survival (OS) was 25.1 months (95% CI, 13.1-not reached] and the 30-month OS rate was 46.3% (95% CI, 29.8%-61.3%). The median duration of response was not reached. Treatment-related adverse events (TRAEs) were reported in 78.6% of patients; the incidence of grade 3 to 5 TRAEs was 23.8%. No additional treatment-related deaths occurred since the initial analysis. Pembrolizumab provided durable antitumor activity and an acceptable safety profile in Japanese patients with advanced melanoma.

A high-capacity, high-power organic electrode via supercritical CO2 impregnation into activated carbon micropores.

Herein, we report the impregnation of chloranil into activated carbon micropores using scCO2. The sample prepared under 105 °C and 15 MPa showed a specific capacity of 81 mAh gelectrode-1, except for the electric double layer capacity at 1 A gelectrode-Polytetrafluoroethylene (PTFE)-1. Additionally, approximately 90% of the capacity was retained even at 4 A gelectrode-PTFE-1.

Progress on Separation and Hydrothermal Carbonization of Rice Husk Toward Environmental Applications.

Owing to the increasing global demand for carbon resources, pressure on finite materials, including petroleum and inorganic resources, is expected to increase in the future. Efficient utilization of waste resources has become crucial for sustainable resource acquisition for creating the next generation of industries. Rice husks, which are abundant worldwide as agricultural waste, are a rich carbon source with a high silica content and have the potential to be an effective raw material for energy-related and environmental purification materials such as battery, catalyst, and adsorbent. Converting these into valuable resources often requires separation and carbonization; however, these processes incur significant energy losses, which may offset the benefits of using biomass resources in the process steps. This review summarizes and discusses the high value of RHs, which are abundant as agricultural waste. Technologies for separating and converting RHs into valuable resources by hydrothermal carbonization are summarized based on the energy efficiency of the process.

Reflection on feasibility and usability of interactive online international exchange program for occupational therapy students.

The COVID-19 pandemic affected international exchange programs due to travel restrictions. There are few reports of online international exchange programs in medical area and no report of interactive activities among students together for several months. To the best of our knowledge, we needed to seek the feasible approach to conduct online exchange program. We experienced online collaboration works to promote internationalization in occupational therapy (OT) undergraduate education. The aim of this study is to examine the feasibility and usability of an interactive online international exchange program, and discuss its challenges and advantages. The three-month program was newly developed, and aimed at cultivating an international perspective, understanding OT, and learning basic research skills. Students' interests and the development of their motivation were considered in the program consisting of synchronous and asynchronous lectures, a collaboration research project, group work, and report assignments. Through the program, students were satisfied with the program contents and had the precious experience to develop international relationships. The online exchange program provided students with the opportunity to experience and learn OT education internationally at an economical cost, and to achieve program goal during the regular semester. In this program, students not only acquired knowledge in their professional field, but also cultivated their international communication skills in English from small group activities and social activities. Considering various communication methods was an important aspect in the virtual environment leading to a successful program. In medical education, an online program can be an effective and practical measure for international exchange. Supplementary Information: The online version contains supplementary material available at 10.1007/s44217-023-00031-4.

Colloidal Stability of Emulsifier-free Triolein-in-Water Emulsions: Effects of Temperature.

Herein, we report the colloidal stability of emulsifier-free (EF-) triolein-in-water (TO/W) emulsions prepared by mixing TO and water using a high-powered bath-type ultrasonicator (HPBath-US; 28 kHz, 300 W) in the absence of emulsifiers such as surfactants. In particular, the effect of the temperature (15-60℃) on the colloidal stability of EF-TO/W emulsions was examined because this is important for the practical application of EF-TO/W emulsions, for example, in foods, pharmaceuticals, and cosmetics. We found that the colloidal stability of the EF-TO/W emulsions decreased with increase in the temperature from 15 to 25°C, whereas it increased with increase in temperature from 25 to 40°C, and the high colloidal stability of the EF-TO/W emulsions was maintained above 40°C. The reduction in the colloidal stability of EF-TO/W emulsions between 15 and 25°C is likely a result of the TO droplets formed by thermal motion, as well as enhanced Ostwald ripening at higher temperatures. On the other hand, the increase in the colloidal stability of the EF-TO/W emulsions from 25 to 40°C and their high colloidal stability above 40℃ is attributed to the reduction in the interfacial tension between TO and water at higher temperatures. This decrease in the interfacial tension between TO and water with temperature increase is related to the transformation of short-range ordered domains (clusters) of TO molecules in the liquid state, which increases the colloidal stability of the EF-TO/W emulsions.

Cervical Myelopathy Screening with Machine Learning Algorithm Focusing on Finger Motion Using Noncontact Sensor.

STUDY DESIGN: Cross-sectional study. OBJECTIVE: To develop a binary classification model for cervical myelopathy (CM) screening based on a machine learning algorithm using Leap Motion (Leap Motion, San Francisco, CA), a novel noncontact sensor device. SUMMARY OF BACKGROUND DATA: Progress of CM symptoms are gradual and cannot be easily identified by the patients themselves. Therefore, screening methods should be developed for patients of CM before deterioration of myelopathy. Although some studies have been conducted to objectively evaluate hand movements specific to myelopathy using cameras or wearable sensors, their methods are unsuitable for simple screening outside hospitals because of the difficulty in obtaining and installing their equipment and the long examination time. METHODS: In total, 50 and 28 participants in the CM and control groups were recruited, respectively. The diagnosis of CM was made by spine surgeons. We developed a desktop system using Leap Motion that recorded 35 parameters of fingertip movements while participants gripped and released their fingers as rapidly as possible. A support vector machine was used to develop the binary classification model, and a multiple linear regression analysis was performed to create regression models to estimate the total Japanese Orthopaedic Association (JOA) score and the JOA score of the motor function of the upper extremity (MU-JOA score). RESULTS: The binary classification model indexes were as follows: sensitivity, 84.0%; specificity, 60.7%; accuracy, 75.6%; area under the curve, 0.85. The Spearman rank correlation coefficient between the estimated score and the total JOA score was 0.44 and that between the estimated score and the MU-JOA score was 0.51. CONCLUSION: Our binary classification model using a machine learning algorithm and Leap Motion could classify CM with high sensitivity and would be useful for CM screening in daily life before consulting doctors and telemedicine.Level of Evidence: 3.

Series module of quinone-based organic supercapacitor (> 6 V) with practical cell structure.

Inexpensive, high-performing, and environmentally friendly energy storage devices are required for smart grids that efficiently utilize renewable energy. Energy storage devices consisting of organic active materials are promising because organic materials, especially quinones, are ubiquitous and usually do not require harsh conditions for synthesis, releasing less CO2 during mass production. Although fundamental research-scale aqueous quinone-based organic supercapacitors have shown excellent energy storage performance, no practical research has been conducted. In this study, we aimed to develop a practical-scale aqueous-quinone-based organic supercapacitor. By connecting 12 cells of size 10 cm × 10 cm × 0.5 cm each in series, we fabricated a high-voltage (> 6 V) aqueous organic supercapacitor that can charge a smartphone at a 1 C rate. This is the first step in commercializing aqueous organic supercapacitors that could solve environmental problems, such as high CO2 emissions, air pollution by toxic metals, and limited electricity generation by renewable resources.

Myosin light chain kinase/actin interaction in phorbol dibutyrate-stimulated smooth muscle cells.

Previous work has suggested that in addition to its kinase activity, myosin light chain kinase (MLCK) exhibits non-kinase properties within its N-terminus that could influence cytoskeletal organization of smooth muscle cells (A. Nakamura et al. Biochem Biophys Res Commun. 2008;369:135-143). Myosin ATPase activity measurements indicate that the 26-41 peptide of MLCK significantly decreases ATPase activity as the concentration of this peptide increases. Sliding velocity of actin-filaments on myosin and stress responses in skinned smooth muscle tissue are also inhibited. Peptide-mediated uptake and the microinjection technique in cells indicate that the peptide was necessary for actin-filament stabilization. Fluorescence resonance energy transfer analysis indicated that in the presence of MLCK, α-actin but not ß-actin remodeled during phorbol 12,13-dibutyrate (PDBu)-induced contractions. PDBu also induced podosomes in the cell. When MLCK expression was down-regulated by introduction of RNAi for MLCK by lentivirus vector into the cells, we failed to observe the podosome induction upon PDBu stimulation. Rescue experiments indicate that the non-kinase activity of MLCK plays an important role in maintaining actin stress fibers and in the PDBu-induced reorganization of actin-filaments in smooth muscle cells.

Blebbistatin, a myosin II inhibitor, suppresses contraction and disrupts contractile filaments organization of skinned taenia cecum from guinea pig.

To explore the precise mechanisms of the inhibitory effects of blebbistatin, a potent inhibitor of myosin II, on smooth muscle contraction, we studied the blebbistatin effects on the mechanical properties and the structure of contractile filaments of skinned (cell membrane permeabilized) preparations from guinea pig taenia cecum. Blebbistatin at 10 microM or higher suppressed Ca(2+)-induced tension development at any given Ca(2+) concentration but had little effects on the Ca(2+)-induced myosin light chain phosphorylation. Blebbistatin also suppressed the 10 and 2.75 mM Mg(2+)-induced, "myosin light chain phosphorylation-independent" tension development at more than 10 microM. Furthermore, blebbistatin induced conformational change of smooth muscle myosin (SMM) and disrupted arrangement of SMM and thin filaments, resulting in inhibition of actin-SMM interaction irrespective of activation with Ca(2+). In addition, blebbistatin partially inhibited Mg(2+)-ATPase activity of native actomyosin from guinea pig taenia cecum at around 10 microM. These results suggested that blebbistatin suppressed skinned smooth muscle contraction through disruption of structure of SMM by the agent.