High-Density Microporous Drainage-Integrating Sheath Flow Generator for Streamlining Microfluidic Cell Sorting Systems.

Tremendous efforts have been made to develop practical and efficient microfluidic cell and particle sorting systems; however, there are technological limitations in terms of system complexity and low operability. Here, we propose a sheath flow generator that can dramatically simplify operational procedures and enhance the usability of microfluidic cell sorters. The device utilizes an embedded polydimethylsiloxane (PDMS) sponge with interconnected micropores, which is in direct contact with microchannels and seamlessly integrated into the microfluidic platform. The high-density micropores on the sponge surface facilitated fluid drainage, and the drained fluid was used as the sheath flow for downstream cell sorting processes. To fabricate the integrated device, a new process for sponge-embedded substrates was developed through the accumulation, incorporation, and dissolution of PMMA microparticles as sacrificial porogens. The effects of the microchannel geometry and flow velocity on the sheath flow generation were investigated. Furthermore, an asymmetric lattice-shaped microchannel network for cell/particle sorting was connected to the sheath flow generator in series, and the sorting performances of model particles, blood cells, and spiked tumor cells were investigated. The sheath flow generation technique developed in this study is expected to streamline conventional microfluidic cell-sorting systems as it dramatically improves versatility and operability.

Quantifying the shear modulus of the adductor longus muscle during hip joint motion using shear wave elastography.

The present study aims to assess the effect of the hip flexion angle on the shear modulus of the adductor longus (AL) muscle associated with passive hip abduction and rotation. Sixteen men participated in the study. For the hip abduction task, the hip flexion angles used were - 20, 0, 20, 40, 60, and 80°, and the hip abduction angles were 0, 10, 20, 30, and 40°. For the hip rotation task, the hip flexion angles used were - 20, 0, 20, 40, 60, and 80°, hip abduction angles were 0 and 40°, and hip rotation angles were 20° internal rotation, 0° rotation, and 20° external rotation. The shear modulus at 20° extension was significantly higher than that at 80° flexion for the 10, 20, 30 and 40° hip abduction (i.e., P < 0.05). The shear modulus at 20° internal rotation and 20° extension was significantly higher than that at 0° rotation and 20° external rotation, regardless of the hip abduction angle (i.e., P < 0.05). The mechanical stress of the AL muscle associated with hip abduction was higher in the extended position. Furthermore, the mechanical stress could increase with internal rotation only at the hip-extended position.

Relationship between shear elastic modulus and passive muscle force in human hamstring muscles using a Thiel soft-embalmed cadaver.

PURPOSE: Assessing muscle flexibility and architecture is important for hamstring strain injury (HSI) prevention. We investigated the relationship between shear modulus and passive force in hamstring muscles at different sites and the effect of muscle architecture on the slope of the shear modulus-passive force using shear wave elastography (SWE). METHODS: The biceps femoris long head (BFlh), semitendinosus (ST), and semimembranosus (SM) muscles were dissected from nine Thiel-embalmed cadavers and fixed to a custom-made mechanical testing machine. Calibrated weights (0-1800 g) were applied gradually in 150-g increments. The shear modulus and anatomical cross-sectional area (ACSA) were measured at proximal, central, and distal points using SWE. The muscle mass and length were measured before the loading test. The shear modulus-passive load relationship of each tested muscle region was analyzed by fitting a least-squares regression line. The increase in shear modulus slope per unit load was calculated and compared between the muscles before and after normalization by the muscle mass, length, and ACSA. RESULTS: The shear modulus and passive force for all hamstring muscles in each region showed a statistically significant linear correlation. Furthermore, the increase in shear modulus slope was greater for BFlh and ST than for SM (P < 0.05), but after normalization by the muscle length and ACSA, there were no significant differences among the muscles. CONCLUSION: The local mechanical properties of individual hamstring muscles can be indirectly estimated using SWE, and the slope of increase in shear modulus reflects characteristics of the muscle architecture.

Effects of superficial tissue and intermuscular connections on rectus femoris muscle shear modulus heterogeneity.

INTRODUCTION: Intramuscular heterogeneity exists in the shear modulus of the rectus femoris (RF) muscle. However, the underlying heterogeneity mechanisms are not entirely understood. Previous research has reported that detachment of superficial tissues reduces the shear modulus by 50%. The aim of this study was to examine the effects of the skin, deep fascia, and intermuscular connections on the shear modulus of the RF at multiple sites. MATERIALS AND METHODS: Eleven donors were fixed using the Thiel method. Measurements were performed at 0°, 60°, and 120° knee flexion in a neutral hip position. Tissue processing was performed under four conditions: superficial tissue (CONT), skin off (SKIN), deep fascia detachment (FASC), and intermuscular connections detachment (ALL). The shear modulus at the proximal, central, and distal regions were measured using ultrasound shear wave elastography. The study was approved by the Sapporo Medical University Ethical Committee. RESULTS: Three-way ANOVA revealed no significant interaction between treatment, site, and angle (P = 0.156), treatment and angle (P = 0.067), or site and angle (P = 0.441). There was a significant effect of treatment (P < 0.001), site (P = 0.010), and angle (P < 0.001) and interaction between treatment and site (P < 0.001). The proximal shear modulus was greater than the central for CONT. There were no significant differences between the measurement sites for SKIN. The distal shear modulus was greater than the proximal for FASC. The distal shear modulus was also greater than the proximal and central for ALL. CONCLUSIONS: Intramuscular regional differences that influence superficial tissue and intermuscular connections of RF elasticity heterogeneity were observed.

Propensity score analysis comparing off-pump versus on-pump coronary artery bypass grafting in older adults.

OBJECTIVE: This study aimed to compare the results of off-pump and on-pump coronary artery bypass grafting in older adults and to examine early and late outcomes. METHODS: This study included 226 patients aged ≥ 75 years who underwent isolated coronary artery bypass grafting. Of these, 141 and 85 patients were included in the off-pump and on-pump groups, respectively. Propensity scores were calculated for each case, matched, and compared between the two groups (68 cases in each group), along with mid-term outcomes of survival and major adverse cardiac events. RESULTS: Operative time, red blood cell transfusion volume, and postoperative hospital stay duration were significantly higher in the on-pump group (267 vs 370 min, P < 0.001; 4.3 vs 17.2 units, P < 0.001; and 20.8 vs 35.8 days, P = 0.012, respectively). Postoperative occurrence of new atrial fibrillation was significantly higher in the on-pump group (4.4% vs 27.9%, P < 0.001), and Kaplan-Meier survival analysis showed a significantly worse prognosis in the on-pump group than in the off-pump group (3-year survival rate 90.7% vs 71.5%, log rank P = 0.007). However, there was no statistically significant difference in cardiovascular-related deaths (log rank P = 0.07). CONCLUSIONS: On-pump coronary artery bypass grafting in an older adult population resulted in increased transfusion volume and postoperative occurrence of atrial fibrillation. The mid-term postoperative outcomes were also poorer with on-pump coronary artery bypass grafting. Off-pump coronary artery bypass grafting reduced future all-cause deaths in older adults.

Effect of chest mobilization on intercostal muscle stiffness.

This study examined the effect of chest mobilization on intercostal (IC) muscle stiffness using the IC muscle shear modulus. Sixteen healthy young men participated on two days with a minimum of 24 h between the stretching and control conditions (SC and CC). The tasks were resting breathing and deep breathing. The IC muscle shear modulus and muscle activity and rib cage circumference were measured before and after each condition. In the SC, IC stretching was performed for 1 min x 5 sets. In the CC, resting breathing, in a sitting position, was performed for 5 min. In the SC, the IC muscle shear modulus decreased significantly (p < 0.05) at maximum inspiration in the deep breathing task, but there was no significant difference in the CC pre- and post-intervention. The results suggest that IC muscle stretching decreases IC muscle stiffness and improves muscle flexibility and that the IC muscle shear modulus may measure the effectiveness of chest mobilization.

Adductor longus: An anatomical study to better understand groin pain.

We investigated the shear modulus-passive force relationship in the hip adductor longus (AL) muscles of human cadavers and explored the effect of muscle architecture on the elastic properties of the AL muscle using shear wave elastography (SWE). Nine AL muscles were harvested from a soft, embalmed cadaver. The AL muscles were affixed to a custom-built device comprising two clamps, a pulley, and a cable to provide passive loads, which were increased from 0 to 600 g in 60-g increments. The shear modulus of the AL muscle was measured in the proximal (Pro), middle (Mid), and distal (Dis) regions. The masses and anatomical cross-sectional areas (ACSAs) of the AL muscles were measured. The shear modulus-passive load relationship of each tested muscle region was analyzed by fitting a least-squares regression line. Moreover, the rate of increase in the shear modulus per unit load (s) was calculated. The shear modulus and passive force were linearly correlated for all AL muscles in each region (p < 0.01). The mean coefficients of determination (R2 ) for Pro, Mid, and Dis were 0.989, 0.986, and 0.982, respectively. The rate of increase in the shear modulus per unit load significantly correlated with the reciprocal of the muscle mass (r = 0.77, p = 0.02) and ACSA (r = 0.43, p = 0.03). Shear wave elastography can be used as an indirect measure of passive force in any region of the AL muscle. Additionally, the rate of increase in the shear modulus per unit load could be associated with muscle architectural parameters.

Early detachment of prosthetic aortic valve one year after replacement for severe aortic regurgitation due to perforated aortic valve aneurysm; a case of suspected HLA-B52 positive Behçet's disease.

Herein, we report a case of 61-year-old male with congestive heart failure (HF) due to severe aortic regurgitation (AR) caused by ruptured aortic valve aneurysm (VA). Aortic valve replacement (AVR) was performed after improvement of HF symptoms. Pathological examination of resected aortic VA showed neutrophil infiltration. Although he did not have typical clinical features associated with infective endocarditis (IE) such as fever, leukocytosis, or positive blood culture, we misdiagnosed this case as "concealed IE". However, we reconsidered the etiology because prosthetic aortic valve detachment occurred only one year after AVR. When considering causes except IE for perforated aortic VA and early prosthetic valve detachment, Behçet's disease (BD) was more likely based on the clinical course, echocardiography, and pathological findings in this case. The inflammatory process of BD is associated with aortic valvulitis/aortitis, leading to a possible cause of aortic regurgitation due to aortic VA or early prosthetic valve detachment. The diagnosis of BD was challenging in this case because he did not have predominant clinical findings, including recurrent oral ulcer which is a mandatory criterion for the diagnosis by the International Study Group, however, cardiac involvement may have been the initial presentation of BD. .

Ribavirin induces hepatitis C virus genome mutations in chronic hepatitis patients who failed to respond to prior daclatasvir plus asunaprevir therapy.

Ribavirin (RBV) induces nucleotide (nt) substitutions in hepatitis C virus (HCV) genome nonstructural (NS) regions. Although emergence of drug resistance-associated variants is associated with direct-acting antiviral treatment failure, the effect of RBV on genome substitutions in such patients is unknown. Genotype 1b HCV subgenomic replicon cells were treated with RBV for 120 hours. Six patients with chronic genotype 1b with HCV-infected patients who failed to respond to prior daclatasvir plus asunaprevir (DCV/ASV) therapy were treated with 12 weeks of sofosbuvir and ledipasvir plus RBV after 4 weeks of RBV monotherapy. RBV-induced genome mutations in the HCV NS region (nt3493-9301) in replicon cells and in patients during 4 weeks of RBV monotherapy were analyzed by deep sequencing. RBV-associated G-to-A and C-to-U transitions increased in a dose-dependent manner in HCV replicon cells after the RBV treatment. In patients with prior DCV/ASV treatment failures, the median serum HCV RNA level was 6.25 ± 0.31 log IU/mL at the start of RBV therapy and decreased significantly to 5.95 ± 0.4 log IU/mL (P = .03) after 4 weeks of RBV monotherapy. Although predominant HCV genome substitutions rates were similar between nontreatment and RBV-treatment periods (0.042 and 0.031 per base pair, respectively; P = .248), the frequencies of G-to-A and C-to-U transitions significantly increased after RBV monotherapy. These transitions were enriched, particularly within the HCV NS3 region in all patients. RBV treatment induces G-to-A and C-to-U transitions in the HCV genome even in chronic patients with hepatitis C with prior DCV/ASV treatment failures.

Limitations of daclatasvir/asunaprevir plus beclabuvir treatment in cases of NS5A inhibitor treatment failure.

Combined daclatasvir (DCV)/asunaprevir (ASV) plus beclabuvir (BCV) treatment shows a high virological response for genotype 1b chronic hepatitis C patients. However, its efficacy for patients for whom previous direct-acting antiviral (DAA) therapy failed is not known. We analysed the efficacy of DCV/ASV/BCV treatment for HCV-infected mice and chronic hepatitis patients. Human hepatocyte chimaeric mice were injected with serum samples obtained from either a DAA-naïve patient or a DCV/ASV treatment failure and were then treated with DCV/ASV alone or in combination with BCV for 4 weeks. DCV/ASV treatment successfully eliminated the virus in DAA-naïve-patient HCV-infected mice. DCV/ASV treatment failure HCV-infected mice developed viral breakthrough during DCV/ASV treatment, with the emergence of NS5A-L31V/Y93H HCV resistance-associated variants (RAVs) being observed by direct sequencing. DCV/ASV/BCV treatment inhibited viral breakthrough in NS5A-L31V/Y93H-mutated HCV-infected mice, but HCV relapsed with the emergence of NS5B-P495S variants after the cessation of the treatment. The efficacy of the triple therapy was also analysed in HCV-infected patients; one DAA-naïve patient and four prior DAA treatment failures were treated with 12 weeks of DCV/ASV/BCV therapy. Sustained virological response was achieved in a DAA-naïve patient and one of the DCV/ASV treatment failures through DCV/ASV/BCV therapy; however, HCV relapse occurred in the other patients with prior DCV/ASV and/or sofosbuvir/ledipasvir treatment failures. DCV/ASV/BCV therapy seems to have limited efficacy for patients with NS5A RAVs for whom prior DAA treatment has failed.

Ductus Aneurysm Ruptured Into the Esophagus With Massive Bleeding.

We report a patient with life-threatening hematemesis caused by the rupture of a ductus aneurysm into the esophagus, which was successfully treated by coil embolism for the esophageal fistula through the aorta and subsequent thoracic endovascular aortic replacement. Second-stage therapy was performed surgically after proactive antibiotic treatment and in consideration of the patient's improved general condition. This included debridement with drainage, aortic encasement with remnant aneurysmal wall, omentopexy, and jejunostomy. The esophagus was preserved, and satisfactory healing and natural closure of the fistula were achieved. Although repeated aspirations were later required for pleural fluid, such inflammatory complications finally subsided.

Challenging Residual Contamination of Instruments for Robotic Surgery in Japan.

BACKGROUND Recently, robotic surgery has been introduced in many hospitals. The structure of robotic instruments is so complex that updating their cleaning methods is a challenge for healthcare professionals. However, there is limited information on the effectiveness of cleaning for instruments for robotic surgery. OBJECTIVE To determine the level of residual contamination of instruments for robotic surgery and to develop a method to evaluate the cleaning efficacy for complex surgical devices. METHODS Surgical instruments were collected immediately after operations and/or after in-house cleaning, and the level of residual protein was measured. Three serial measurements were performed on instruments after cleaning to determine the changes in the level of contamination and the total amount of residual protein. The study took place from September 1, 2013, through June 30, 2015, in Japan. RESULTS The amount of protein released from robotic instruments declined exponentially. The amount after in-house cleaning was 650, 550, and 530 µg/instrument in the 3 serial measurements. The overall level of residual protein in each measurement was much higher for robotic instruments than for ordinary instruments (P<.0001). CONCLUSIONS Our data demonstrated that complete removal of residual protein from surgical instruments is virtually impossible. The pattern of decline differed depending on the instrument type, which reflected the complex structure of the instruments. It might be necessary to establish a new standard for cleaning using a novel classification according to the structural complexity of instruments, especially for those for robotic surgery. Infect Control Hosp Epidemiol 2017;38:143-146.

Time-dependent influence on assessment of contaminated environmental surfaces in operating rooms.

BACKGROUND: There is no established method to assess the contamination of environmental surfaces because the results change with time. We evaluated current methods for assessment of contamination of environmental surfaces in the operating room (OR). METHODS: Contamination of environmental surfaces in the OR was assessed using an adenosine triphosphate (ATP) test and bacterial culture. We collected 480 ATP test samples from 17 surfaces in 6 ORs to determine the influence of surface features, including frequency of touching and surface orientation on contamination, after completion of daily scheduled operations. Another 54 pairs of ATP and microbial samples were taken from 3 surfaces in each of the same OR except 1 to determine the time course of the results of ATP and microbial tests when ORs were not used. RESULTS: Multivariate analysis demonstrated that the ATP results were strongly influenced by frequency of touching and orientation of environmental surfaces. The microbial counts declined over time, whereas the ATP results remained at a high level. CONCLUSION: The ATP test result could be used as a relatively stable trace of contamination of environmental surfaces; however, it is not a surrogate indicator of the number of viable microbes which declines over time.

Occult risk of broken instruments for endoscopy-assisted surgery.

BACKGROUND: The influence of broken sophisticated surgical instruments on the safety of surgery has yet to be determined, in spite of an assumption that breakage of surgical instruments is not associated with critical incidents. The purpose of the present study was to delineate the risk from breakage of surgical instruments used in surgery assisted by endoscopy. METHODS: A retrospective analysis was conducted to determine the frequency of breakage of instruments used in 39,817 operations from 2007 to 2011. Data of breakage were collected using incident/near-incident reports and the request forms for repair of broken instruments. RESULTS: During the study period, 441 instruments were reported to be broken intraoperatively, and 7,541 were found to be broken on inspection. The incidence of breakage adjusted by the number of operations and the number of uses suggested that instruments for endoscopy-assisted surgery are broken more frequently intraoperatively than are any other type of instruments (visceral surgery: 0.039 versus 0.017, P = 0.0002, RR = 2.318; obstetrics/gynecology: 0.023 versus 0.0067, P < 0.0001, RR = 3.461; thoracic surgery: 0.019 versus 0.004, P = 0.0772, RR = 5.212). Inappropriate use and wearing out were two major possible causes of breakage of instruments. The predominant adverse events were suggested to be attributable to parts falling off broken instruments because of inappropriate use. CONCLUSIONS: Our results demonstrated that surgery assisted by endoscopy has its own occult risk, which has not been previously highlighted. Minimally invasive surgery is not necessarily safe with respect to breakage of surgical instruments. Our data provide substantial evidence for higher risk of instrument breakage in endoscopy-assisted surgery, as well as its possible detrimental effect on patient safety.

[A case report of hepatocellular carcinoma with metastases to the lip, stomach, and colorectum].

A 79-year-old man was diagnosed with hepatocellular carcinoma in 2000 and treated with partial hepatectomy. Intrahepatic carcinoma recurred with lung metastases 7 years later. Several transcatheter arterial chemoembolizations were performed to treat the recurrence, and a right lower lobectomy was performed for lung metastasis. Twelve years after the original carcinoma diagnosis, lip and lung metastases were detected, and he was hospitalized for radiotherapy of the lung metastasis; an oral molecular-targeting drug was initiated. During the therapy, hematochezia was observed, and a colonoscopy was performed. A submucosal lesion with a blood clot measuring approximately 4mm in diameter was found in the sigmoid colon, and endoscopic mucosal resection was performed. Furthermore, an elevated lesion with a 5-mm diameter recess was observed on upper gastrointestinal endoscopy. Both lesions were diagnosed histopathologically as hepatocellular carcinoma metastases.