Gastric Tube Insertion Performance of Second-Generation Supraglottic Airway Devices: A Prospective Manikin Study With Literature Review.

BACKGROUND: Second-generation supraglottic airway devices (SGAs) are pivotal in airway management, with the ability to accommodate gastric tube (GT) insertion. However, research on GT insertion with SGAs under controlled conditions is limited. This study aimed to evaluate the GT insertion performance of SGAs using a manikin. METHODS: This prospective study included 32 anesthesiologists in our department, each with more than two years of clinical experience. These anesthesiologists randomly inserted four second-generation SGAs, including i-gel (Intersurgical Ltd., Berkshire, UK), Ambu AuraGain (Ambu, Copenhagen, Denmark), LMA ProSeal (Teleflex Medical, Wayne, PA), and LMA Supreme (Teleflex Medical), all of size 4, into a manikin, followed by GT insertion using Salem Sump™ tubes (Cardinal Health, Dublin, OH) (12 Fr for i-gel and 14 Fr for others) until the GT was 55 cm deep at the port entrance. The primary outcome was the difference in GT insertion time, with participants' evaluations. The usual use of second-generation SGAs, including GT insertion, was also surveyed. The differences in GT insertion time among the four SGAs were analyzed using the Friedman test, followed by the Bonferroni method for post-hoc analysis. P < 0.05 was considered significant. RESULTS: The median GT insertion times were 17.2 seconds for i-gel, 9.9 seconds for AuraGain, 18.8 seconds for ProSeal, and 8.9 seconds for Supreme. These times showed significant differences (p < 0.001). Post-hoc analysis revealed that both Supreme and AuraGain had significantly shorter insertion times than i-gel and ProSeal, respectively (p < 0.001). Of the participants, 59% (19/32) evaluated Supreme as the easiest SGA for GT insertion, which is consistent with the observed insertion times. i-gel was the most frequently used SGA, chosen by 72% (23/32) of participants. Additionally, 72% (23/32) of anesthesiologists inserted GTs less than half as often following second-generation SGA placement. CONCLUSIONS: Significant differences in GT insertion performance were found among the four second-generation SGAs. According to a survey of participants, second-generation SGAs were often used without GT insertion. Although the differences between products may not be clinically significant, selecting an SGA with easy GT insertion may improve the efficiency and reliability of gastric content drainage and enhance the safety of airway management when using SGAs.

Interaction of Receptor-Binding Domain of the SARS-CoV-2 Omicron Variant with hACE2 and Actin.

The omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was identified in 2021 as a variant with heavy amino acid mutations in the spike protein, which is targeted by most vaccines, compared to previous variants. Amino acid substitutions in the spike proteins may alter their affinity for host viral receptors and the host interactome. Here, we found that the receptor-binding domain (RBD) of the omicron variant of SARS-CoV-2 exhibited an increased affinity for human angiotensin-converting enzyme 2, a viral cell receptor, compared to the prototype RBD. Moreover, we identified ß- and γ-actin as omicron-specific binding partners of RBD. Protein complex predictions revealed that many omicron-specific amino acid substitutions affected the affinity between RBD of the omicron variant and actin. Our findings indicate that proteins localized to different cellular compartments exhibit strong binding to the omicron RBD.

Transesophageal Echocardiographic Evaluation of Coronary Blood Flow and the Initial Flap Assisting in the Surgical Decision-Making: A Case of Acute Type A Aortic Dissection.

Acute aortic dissection is a life-threatening condition. Myocardial ischemia associated with dissection occurs due to direct extension into the coronary artery or indirect involvement of the coronary ostia secondary to the dissection flap. Thus, the surgical procedure may require coronary reconstruction, in addition to aortic replacement. We experienced a case in which coronary artery reconstruction could be avoided because intraoperative transesophageal echocardiography showed that the aortic flap did not obstruct the right coronary artery in systole, and pulsed Doppler imaging indicated that there was sufficient coronary blood flow. This case shows that it is critical to establish a correct and early diagnosis and to proceed with the appropriate treatment for patients with myocardial ischemia.

Hetero-oligomerization of TDP-43 carboxy-terminal fragments with cellular proteins contributes to proteotoxicity.

Carboxy terminal fragments (CTFs) of TDP-43 contain an intrinsically disordered region (IDR) and form cytoplasmic condensates containing amyloid fibrils. Such condensates are toxic and associated with pathogenicity in amyotrophic lateral sclerosis. However, the molecular details of how the domain of TDP-43 CTFs leads to condensation and cytotoxicity remain elusive. Here, we show that truncated RNA/DNA-recognition motif (RRM) at the N-terminus of TDP-43 CTFs leads to the structural transition of the IDR, whereas the IDR itself of TDP-43 CTFs is difficult to assemble even if they are proximate intermolecularly. Hetero-oligomers of TDP-43 CTFs that have recruited other proteins are more toxic than homo-oligomers, implicating loss-of-function of the endogenous proteins by such oligomers is associated with cytotoxicity. Furthermore, such toxicity of TDP-43 CTFs was cell-nonautonomously affected in the nematodes. Therefore, misfolding and oligomeric characteristics of the truncated RRM at the N-terminus of TDP-43 CTFs define their condensation properties and toxicity.

Stress Granule Dysfunction via Chromophore-Associated Light Inactivation.

Stress granules (SGs) are cytoplasmic condensates composed of various proteins and RNAs that protect translation-associated machinery from harmful conditions during stress. However, the method of spatiotemporal inactivation of condensates such as SGs in live cells to study cellular phenotypes is still in the process of being demonstrated. Here, we show that the inactivation of SGs by chromophore-associated light inactivation (CALI) using a genetically encoded red fluorescence protein (SuperNova-Red) as a photosensitizer leads to differences in cell viability during recovery from hyperosmotic stress. CALI delayed the disassembly kinetics of SGs during recovery from hyperosmotic stress. Consequently, CALI could inactivate the SGs, and the cellular fate due to SGs could be analyzed. Furthermore, CALI is an effective spatiotemporal knockdown method for intracellular condensates/aggregates and would contribute to the elucidation of importance of such condensates/aggregates.

Postoperative intravenous patient-controlled analgesia improves pain management after subcutaneous implantable defibrillator implantation.

Objective: Postoperative pain is a major issue with subcutaneous implantable cardioverter defibrillators (S-ICD). In 2020, we introduced intravenous patient-controlled analgesia (IV-PCA) in addition to the conventional, request-based analgesia for postoperative pain control in S-ICD. To determine the effect and safety, we quantitatively assessed the effect of IV-PCA after S-ICD surgery over conventional methods. Methods: During the study period, a total of 113 consecutive patients (age, 50.1 ± 15.5 years: males, 101) underwent a de novo S-ICD implantation under general anesthesia. While the postoperative pain was addressed with either request-based analgesia (by nonsteroid anti-inflammatory drugs, N = 68, dubbed as "PCA absent") or fentanyl-based IV-PCA in addition to the standard care (N = 45, dubbed as "PCA present"). The degree of postoperative pain from immediately after surgery to 1 week were retrospectively investigated by the numerical rating scale (NRS) divided into four groups at rest and during activity (0: no pain, 1-3: mild pain, 4-6: moderate pain, 7-10: severe pain). Results: Although IV-PCA was removed on Day 1, it was associated with continued better pain control compared to PCA absent group. At rest, the proportion of patients expressing pain (mild or more) was significantly lower in the PCA present group from Day 0 to Day 4. In contrast to at rest, a better pain control continued through the entire study period of 7 days. No serious adverse events were observed. A few patients experienced nausea in both groups and the inter-group difference was not found significant. Conclusion: IV-PCA suppresses postoperative pain in S-ICD without major safety concerns.

Comparison of the effect of surgical versus transcatheter aortic valve replacement on the development of postoperative acute kidney injury.

Acute kidney injury (AKI) frequently occurs after cardiac surgery. Recently, transcatheter aortic valve implantation (TAVI), a less invasive option for aortic stenosis (AS), has been increasingly performed, particularly in elderly patients. We retrospectively investigated and compared the incidence and risk factors of postoperative AKI in patients who underwent surgical aortic valve replacement (SAVR) and TAVI. This was a retrospective single-center study. Seven days postoperatively, data were obtained from medical records. Patients were classified into SAVR and TAVI groups based on age, according to the policy of the Japanese Circulation Society. A total of 155 patients underwent surgery for AS between January 2020 and December 2021. Variables included age, sex, risk score, preoperative left ventricular ejection fraction, hypertension, and renal dysfunction. AKI was defined in accordance with the Kidney Disease: Improving Global Outcomes criteria. A total of 33 SAVR and 79 TAVI procedures were included in this study. The incidences of AKI in the SAVR and TAVI groups were 45.5% and 43.0%, respectively. No significant differences existed between the two groups. Weight (p = 0.0392) and pre-renal dysfunction (p = 0.0308) affected the incidence of AKI in the SAVR group, whereas no such variables were identified in the TAVI group. Within the current age-based treatment selection criteria for AS, no significant difference in the incidence of AKI was observed between the two procedures.Although preoperative renal function may be associated with postoperative AKI, further studies are required to select the optimal surgical procedure for patients with renal dysfunction.

Axonal transport of Frizzled5 by Alcadein α-containing vesicles is associated with kinesin-1.

Alcadein α (Alcα) and amyloid-ß protein precursor (APP) are cargo receptors that associate vesicles with kinesin-1. These vesicles, which contain either Alcα or APP, transport various proteins/cargo molecules into axon nerve terminals. Here, we analyzed immune-isolated Alcα- and APP-containing vesicles of adult mouse brains with LC-MS/MS and identified proteins present in vesicles that contained either Alcα or APP. Among these proteins, Frizzled-5 (Fzd5), a Wnt receptor, was detected mainly in Alcα vesicles. Although colocalization ratios of Fzd5 with Alcα are low in the neurites of differentiating neurons by a low expression of Fzd5 in embryonic brains, the suppression of Alcα expression decreased the localization of Fzd5 in neurites of primary cultured neurons. Furthermore, Fzd5-EGFP expressed in primary cultured neurons was preferentially transported in axons with the transport velocities of Alcα vesicles. In synaptosomal fractions of adult-mice brains that express higher levels of Fzd5, the amount of Fzd5 and the phosphorylation level of calcium/calmodulin-dependent protein kinase-II were reduced in the Alcα-deficient mice. These results suggest that reduced transport of Fzd5 by Alcα-containing vesicles associated with kinesin-1 in axon terminals may impair the response to Wnt ligands in the noncanonical Ca2+-dependent signal transduction pathway at nerve terminals of mature neurons.

Increased intracellular crowding during hyperosmotic stress.

Hyperosmotic stress activates in live cells numerous processes and also promotes intracellular protein/RNA aggregation and phase separation. However, the time course and the extent of these changes remain largely uncharacterized. To investigate dynamic changes in intracellular macromolecular crowding (MMC) induced by hyperosmotic stress in live cells, we used fluorescence lifetime imaging microscopy and fluorescence correlation spectroscopy (FCS) to quantify changes in the local environment by measuring the fluorescence lifetime and the diffusion of the monomeric enhanced green fluorescent protein (eGFP), respectively. Real-time monitoring of eGFP fluorescence lifetime showed that a faster response to environmental changes due to MMC is observed than when measuring the acceptor/donor emission ratio using the MMC-sensitive Förster resonance energy transfer sensor (GimRET). This suggests that eGFP molecular electronic states and/or collision frequency are affected by changes in the immediate surroundings due to MMC without requiring conformational changes as is the case for the GimRET sensor. Furthermore, eGFP diffusion assessed by FCS indicated higher intracellular viscosity due to increased MMC during hyperosmotic stress. Our findings reveal that changes in eGFP fluorescence lifetime and diffusion are early indicators of elevated intracellular MMC. Our approach can therefore be used to reveal in live cells short-lived transient states through which MMC builds over time, which could not be observed when measuring changes in other physical properties that occur at slower time scales.

Genome-Wide Association Study Identifies Genetic Polymorphisms Associated with Estimated Minimum Effective Concentration of Fentanyl in Patients Undergoing Laparoscopic-Assisted Colectomy.

Sensitivity to opioids varies widely among individuals. To identify potential candidate single-nucleotide polymorphisms (SNPs) that may significantly contribute to individual differences in the minimum effective concentration (MEC) of an opioid, fentanyl, we conducted a three-stage genome-wide association study (GWAS) using whole-genome genotyping arrays in 350 patients who underwent laparoscopic-assisted colectomy. To estimate the MEC of fentanyl, plasma and effect-site concentrations of fentanyl over the 24 h postoperative period were estimated with a pharmacokinetic simulation model based on initial bolus doses and subsequent patient-controlled analgesia doses of fentanyl. Plasma and effect-site MECs of fentanyl were indicated by fentanyl concentrations, estimated immediately before each patient-controlled analgesia dose. The GWAS revealed that an intergenic SNP, rs966775, that mapped to 5p13 had significant associations with the plasma MEC averaged over the 6 h postoperative period and the effect-site MEC averaged over the 12 h postoperative period. The minor G allele of rs966775 was associated with increases in these MECs of fentanyl. The nearest protein-coding gene around this SNP was DRD1, encoding the dopamine D1 receptor. In the gene-based analysis, the association was significant for the SERP2 gene in the dominant model. Our findings provide valuable information for personalized pain treatment after laparoscopic-assisted colectomy.

Intracellular Conformation of Amyotrophic Lateral Sclerosis-Causative TDP-43.

Transactive response element DNA/RNA-binding protein 43 kDa (TDP-43) is the causative protein of amyotrophic lateral sclerosis (ALS); several ALS-associated mutants of TDP-43 have been identified. TDP-43 has several domains: an N-terminal domain, two RNA/DNA-recognition motifs, and a C-terminal intrinsically disordered region (IDR). Its structures have been partially determined, but the whole structure remains elusive. In this study, we investigate the possible end-to-end distance between the N- and C-termini of TDP-43, its alterations due to ALS-associated mutations in the IDR, and its apparent molecular shape in live cells using Förster resonance energy transfer (FRET) and fluorescence correlation spectroscopy (FCS). Furthermore, the interaction between ALS-associated TDP-43 and heteronuclear ribonucleoprotein A1 (hnRNP A1) is slightly stronger than that of wild-type TDP-43. Our findings provide insights into the structure of wild-type and ALS-associated mutants of TDP-43 in a cell.

Trans-cis isomerization kinetics of cyanine dyes reports on the folding states of exogeneous RNA G-quadruplexes in live cells.

Guanine (G)-rich nucleic acids are prone to assemble into four-stranded structures, so-called G-quadruplexes. Abnormal GGGGCC repeat elongations, and in particular their folding states, are associated with amyotrophic lateral sclerosis and frontotemporal dementia. Due to methodological constraints however, most studies of G quadruplex structures are restricted to in vitro conditions. Evidence of how GGGGCC repeats form into G-quadruplexes in vivo is sparse. We devised a readout strategy, exploiting the sensitivity of trans-cis isomerization of cyanine dyes to local viscosity and sterical constraints. Thereby, folding states of cyanine-labeled RNA, and in particular G-quadruplexes, can be identified in a sensitive manner. The isomerization kinetics, monitored via fluorescence blinking generated upon transitions between a fluorescent trans isomer and a non-fluorescent cis isomer, was first characterized for RNA with GGGGCC repeats in aqueous solution using fluorescence correlation spectroscopy and transient state (TRAST) monitoring. With TRAST, monitoring the isomerization kinetics from how the average fluorescence intensity varies with laser excitation modulation characteristics, we could then detect folding states of fluorescently tagged RNA introduced into live cells.

Tongue laceration in a patient taking antiplatelet agents during transcranial motor-evoked potential monitoring: a case report.

BACKGROUND: Transcranial motor-evoked potential (Tc-MEP) monitoring is usually performed during surgeries involving a risk of damaging brain motor areas. However, it involves a risk of bite injuries. We report a case of severe tongue laceration from Tc-MEP stimulation during carotid endarterectomy (CEA) in a patient taking antiplatelet agents. CASE PRESENTATION: A 74-year-old man on antiplatelet therapy was scheduled for CEA under general anesthesia with intraoperative Tc-MEP monitoring. Bite blocks were not inserted. Postoperatively, we observed a tongue laceration with severe bleeding, which was sutured. The difficulties in tongue movement persisted for ≥ 1 month postoperatively. CONCLUSIONS: Bite injuries during Tc-MEP may induce severe bleeding in patients on antiplatelets. The complications of tongue bite injuries may persist, decreasing the patients' quality of life. Hence, during Tc-MEP monitoring, it is important to use soft bite blocks and to check the patient's face and the position of the tracheal tube intraoperatively.

Identification of osteoporosis using ensemble deep learning model with panoramic radiographs and clinical covariates.

Osteoporosis is becoming a global health issue due to increased life expectancy. However, it is difficult to detect in its early stages owing to a lack of discernible symptoms. Hence, screening for osteoporosis with widely used dental panoramic radiographs would be very cost-effective and useful. In this study, we investigate the use of deep learning to classify osteoporosis from dental panoramic radiographs. In addition, the effect of adding clinical covariate data to the radiographic images on the identification performance was assessed. For objective labeling, a dataset containing 778 images was collected from patients who underwent both skeletal-bone-mineral density measurement and dental panoramic radiography at a single general hospital between 2014 and 2020. Osteoporosis was assessed from the dental panoramic radiographs using convolutional neural network (CNN) models, including EfficientNet-b0, -b3, and -b7 and ResNet-18, -50, and -152. An ensemble model was also constructed with clinical covariates added to each CNN. The ensemble model exhibited improved performance on all metrics for all CNNs, especially accuracy and AUC. The results show that deep learning using CNN can accurately classify osteoporosis from dental panoramic radiographs. Furthermore, it was shown that the accuracy can be improved using an ensemble model with patient covariates.

Paths of thoracic epidural catheters in children undergoing the Nuss procedure for pectus excavatum repair.

PURPOSE: To investigate the paths of thoracic epidural catheters in children, this retrospective study was performed. METHODS: We investigated 73 children aged 4 to 12 (mean ± SD 7.8 ± 2.3) years, who underwent the Nuss procedure for pectus excavatum repair under combined general and epidural anesthesia over a 5-year period at Tokyo Metropolitan Police Hospital. Following induction of general anesthesia, we inserted a radiopaque epidural catheter via the T5/6 or T6/7 interspace and advanced for 5 cm cephalad in the thoracic epidural space. We evaluated the paths of the epidural catheters on plain chest radiographs after surgery. RESULTS: The median level for the catheter tip location was T3 (range C6-T7), while the median number of vertebrae crossed by the catheter tips was 2.5. In most children, the catheters advanced straight for the first 2-3 cm (1-1.5 vertebrae) in the thoracic epidural space. However, they continued to advance straight in only 25 children, while they exhibited curved or coiled paths in the remaining 48. The catheter tips were located at higher levels in children with straight epidural catheter paths [median (range) T2 (C6-T4)] than in those with curved or coiled paths after the initial 2-3 cm [median (range) T4 (T2-T7)] (p < 0.0001). CONCLUSIONS: Our findings indicate that the course of epidural catheters in children is unpredictable after the first 2-3 cm in the thoracic epidural space. Clinicians should be aware of such findings, although further studies are required for confirmation.

Detection of Protein Aggregation using Fluorescence Correlation Spectroscopy.

Protein aggregation is a hallmark of neurodegenerative disorders such as amyotrophic lateral sclerosis (ALS), Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), and so on. To detect and analyze soluble or diffuse protein oligomers or aggregates, fluorescence correlation spectroscopy (FCS), which can detect the diffusion speed and brightness of a single particle with a single molecule sensitivity, has been used. However, the proper procedure and know-how for protein aggregation detection have not been widely shared. Here, we show a standard procedure of FCS measurement for diffusion properties of aggregation-prone proteins in cell lysate and live cells: ALS-associated 25 kDa carboxyl-terminal fragment of TAR DNA/RNA-binding protein 43 kDa (TDP25) and superoxide dismutase 1 (SOD1). The representative results show that a part of aggregates of green fluorescent protein (GFP)-tagged TDP25 was slightly included in the soluble fraction of murine neuroblastoma Neuro2a cell lysate. Moreover, GFP-tagged SOD1 carrying ALS-associated mutation shows a slower diffusion in live cells. Accordingly, we here introduce the procedure to detect the protein aggregation via its diffusion property using FCS.

Pinhole Closure Improves Spatial Resolution in Confocal Scanning Microscopy.

Confocal microscopy is a simple, super-resolution technique, which does not produce a marked increase in resolution compared to other advanced techniques, such as super-resolution nanoscopy. Here, we present a simple protocol to acquire "slightly, but easily resolved" images by pinhole closure (<1 airy unit) in a conventional confocal scanning microscope equipped with an avalanche photodiode, a detector with high sensitivity. We use murine neuroblastoma Neuro2a cells to demonstrate the image resolution obtained via this protocol without the use of any special software to enhance image quality.

Conformational stabilization of optineurin by the dynamic interaction of linear polyubiquitin.

Optineurin produces intracellular multi-functions involving autophagy, vesicular trafficking, and negative regulation of inflammation signaling through interaction with various proteins such as ATG8/LC3, Rab8, and polyubiquitin. Optineurin is a component of cytoplasmic inclusion bodies (IBs) in motor neurons from amyotrophic lateral sclerosis (ALS), and its mutation E478G, has been identified in patients with ALS. However, the mechanism by which polyubiquitin binding modulates the interaction partners of OPTN and ALS-associated IB formation is still unclear. To address this issue, we analyzed the interaction of Optineurin with Rab8 and LC3 in the absence and presence of linear polyubiquitin chains using fluorescence cross-correlation spectroscopy and IB formation efficiency of the E478G mutant of Optineurin during Rab8 depletion using fluorescence microscopy. Here, we hypothesize that linear polyubiquitin binding to Optineurin dynamically induces LC3 association and Rab8 dissociation, likely through a conformational change of Optineurin, and the dynamic conformational change may prevent the aggregate formation of mutant Optineurin.

Artificial intelligence improves the accuracy of residents in the diagnosis of hip fractures: a multicenter study.

BACKGROUND: Less experienced clinicians sometimes make misdiagnosis of hip fractures. We developed computer-aided diagnosis (CAD) system for hip fractures on plain X-rays using a deep learning model trained on a large dataset. In this study, we examined whether the accuracy of the diagnosis of hip fracture of the residents could be improved by using this system. METHODS: A deep convolutional neural network approach was used for machine learning. Pytorch 1.3 and Fast.ai 1.0 were applied as frameworks, and an EfficientNet-B4 model (a pre-trained ImageNet model) was used. We handled the 5295 X-rays from the patients with femoral neck fracture or femoral trochanteric fracture from 2009 to 2019. We excluded cases in which the bilateral hips were not included within an image range, and cases of femoral shaft fracture and periprosthetic fracture. Finally, we included 5242 AP pelvic X-rays from 4851 cases. We divided these 5242 images into two images per image, and prepared 5242 images including fracture site and 5242 images without fracture site. Thus, a total of 10,484 images were used for machine learning. The accuracy, sensitivity, specificity, F-value, and area under the curve (AUC) were assessed. Gradient-weighted class activation mapping (Grad-CAM) was used to conceptualize the basis for the diagnosis of the fracture by the deep learning algorithm. Secondly, we conducted a controlled experiment with clinicians. Thirty-one residents;young doctors within 2 years of graduation from medical school who rotate through various specialties, were tested using 300 hip fracture images that were randomly extracted from the dataset. We evaluated the diagnostic accuracy with and without the use of the CAD system for each of the 300 images. RESULTS: The accuracy, sensitivity, specificity, F-value, and AUC were 96.1, 95.2, 96.9%, 0.961, and 0.99, respectively, with the correct diagnostic basis generated by Grad-CAM. In the controlled experiment, the diagnostic accuracy of the residents significantly improved when they used the CAD system. CONCLUSIONS: We developed a newly CAD system with a deep learning algorithm from a relatively large dataset from multiple institutions. Our system achieved high diagnostic performance. Our system improved the diagnostic accuracy of residents for hip fractures. LEVEL OF EVIDENCE: Level III, Foundational evidence, before-after study. CLINICAL RELEVANCE: high.