The secreted protein Amuc_1409 from Akkermansia muciniphila improves gut health through intestinal stem cell regulation.

Akkermansia muciniphila has received great attention because of its beneficial roles in gut health by regulating gut immunity, promoting intestinal epithelial development, and improving barrier integrity. However, A. muciniphila-derived functional molecules regulating gut health are not well understood. Microbiome-secreted proteins act as key arbitrators of host-microbiome crosstalk through interactions with host cells in the gut and are important for understanding host-microbiome relationships. Herein, we report the biological function of Amuc_1409, a previously uncharacterised A. muciniphila-secreted protein. Amuc_1409 increased intestinal stem cell (ISC) proliferation and regeneration in ex vivo intestinal organoids and in vivo models of radiation- or chemotherapeutic drug-induced intestinal injury and natural aging with male mice. Mechanistically, Amuc_1409 promoted E-cadherin/ß-catenin complex dissociation via interaction with E-cadherin, resulting in the activation of Wnt/ß-catenin signaling. Our results demonstrate that Amuc_1409 plays a crucial role in intestinal homeostasis by regulating ISC activity in an E-cadherin-dependent manner and is a promising biomolecule for improving and maintaining gut health.

Generation of porcine endometrial organoids and their use as a model for enhancing embryonic attachment and elongation.

In brief: Porcine endometrial organoids (EOs) were isolated and characterized, revealing distinctive features such as unique extracellular matrix formation, fusion into uterine bud-like structures, and facilitation of embryo elongation. The yield of EOs was significantly enhanced by cryopreservation medium supplemented with the rock inhibitor (Y-27632), resulting in reduced expression of apoptotic mRNAs and microRNAs. Abstract: Endometrial organoids (EOs) are acceptable models for understanding maternal-embryonic cross talk. This study was conducted to generate EOs and optimize their cryopreservation and provide coculture modeling with embryos. The endometrial tissues were used for culturing the organoids inside domes of Matrigel®. To improve the long-term storage of EOs, 10 µM ROCK inhibitor (RI) was added to the cryopreservation medium. Day 7 parthenogenetically activated embryos were cocultured with EOs or EO outgrowths, and embryonic cell numbers and embryo attachment were monitored. Spherical EOs 100-300 µm in size can be retrieved on day 7 of culture, and larger EOs, approximately 1.5 mm in diameter, can be maintained in the Matrigel® dome for 21 days. The nuclear expression of Ki67 indicates that more than 80% of EOs nuclei were proliferative. EOs exhibit unique novel characters such as formation of extracellular matrix and ability for fusion. RI increased the yield and quality of organoids after freezing or thawing. The cell number of cocultured embryos increased five-fold, and the proportion of trophoblast outgrowths increased seven-fold compared with those of control embryos. The embryos cultured with EO-conditioned medium showed a better attachment rate than the other models, and - for the first time - we report embryonic elongation. Immunofluorescence staining of the attached embryos showed CDX2 in the periphery of EOs outgrowths. The 3D assembly and cryopreservation of EOs was optimized, and EO coculture supported embryo attachment, trophoblast outgrowth, and elongation, which would provide a valuable tool for studying the intricate processes involved in porcine embryo implantation.

Analgesic efficacy of erector spinae plane block in patients undergoing major gynecologic surgery: A randomized controlled study.

STUDY OBJECTIVE: To investigate the analgesic efficacy of erector spinae plane block (ESPB) in major gynecologic surgery, expressed as cumulative opioid consumption 24 h after surgery. DESIGN: A single-center, patient-assessor blinded, randomized controlled study. SETTING: Samsung medical center (tertiary university hospital), between February 2022 to January 2023. PATIENTS: Eighty-eight females undergoing major surgery with long midline incision for gynecologic malignancy. INTERVENTIONS: Patients were randomly assigned to receive standard systemic analgesia (Control group) or ESPB (ESPB group). ESPB was performed bilaterally at the level of the 9th thoracic vertebra with a mixture of 20 mL of 0.5% ropivacaine and 100 µg of epinephrine. MEASUREMENTS: The primary outcome was cumulative opioid consumption at 24 h postoperatively. Secondary outcomes included opioid consumption and pain severity during the 72 h after surgery. The variables regarding postoperative recovery and patient-centered outcomes were compared. MAIN RESULTS: The mean cumulative opioid consumption 24 h after surgery was 35.8 mg in the ESPB group, which was not significantly different from 41.4 mg in the control group (mean difference, 5.5 mg; 95% CI -1.7 to 12.8 mg; P = 0.128). However, patient satisfaction regarding analgesia was significantly higher in the ESPB group compared with the control group at 24 h postoperative (median difference, -1; 95% CI -3 to 0; P = 0.038). There were no significant differences in the variables associated with postoperative recovery. CONCLUSION: ESPB did not reduce opioid consumption during the 24 h postoperative but attenuated pain intensity during the early period after surgery.

Simultaneous quantification method for multiple antiviral drugs in serum using isotope dilution liquid chromatography-tandem mass spectrometry.

We describe the simultaneous quantification of six antiviral drugs in serum based on high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). The target drugs-hydroxychloroquine, chloroquine, favipiravir, umifenovir, ritonavir, and lopinavir-were extracted and purified from serum with 75 % v/v methanol as the precipitant reagent. The six analytes were clearly separated within 15 min using gradient elution and mixed-mode stationary phase. The measurement accuracy and precision were assured by adopting isotopes as internal standards. The optimized measurement procedure was strictly validated in linearity, sensitivity, accuracy, and precision. To confirm the robustness of the method in matrix, the method was additionally applied to various types of serum, namely hyperlipidemic and hyperglycemic serum. The method was then applied to assess the stability of the drugs in serum in order to set sample handling and storage guides for laboratory testing. Lastly, the method was implemented in different LC-MS systems to confirm its applicability across similar equipment commonly used in clinical testing laboratories. The overall results show that the optimized protocol is suitable for the accurate, simultaneous quantification of the six antiviral drugs in serum, and it is anticipated to satisfactorily serve as a reference protocol for the analysis of a wide range of other antiviral drugs for drug monitoring with various purposes.

Predictive modelling for the diagnosis of oral and laryngeal premalignant and malignant lesions using p53 and Ki-67 expression.

Oral and laryngeal epithelial lesions are currently diagnosed using histological criteria based on the World Health Organization (WHO) classification, which can cause interobserver variability. An integrated diagnostic approach based on immunohistochemistry (IHC) would aid in the interpretation of ambiguous histological findings of epithelial lesions. In the present study, IHC was used to evaluate the expression of p53 and Ki-67 in 114 cases of oral and laryngeal epithelial lesions in 104 patients. Logistic regression analysis and decision tree algorithm were employed to develop a scoring system and predictive model for differentiating the epithelial lesions. Cohen's kappa coefficient was used to evaluate interobserver variability, and next-generation sequencing (NGS) and IHC were used to compare TP53 mutation and p53 expression patterns. Two expression patterns for p53, namely, diffuse expression type (pattern HI) and null type (pattern LS), and the pattern HI for Ki-67 were significantly associated with high-grade dysplasia (HGD) or squamous cell carcinoma (SqCC). With an accuracy and area under the receiver operating characteristic curve (AUC) of 84.6% and 0.85, respectively, the scoring system based on p53 and Ki-67 expression patterns classified epithelial lesions into two types: non-dysplasia (ND) or low-grade dysplasia (LGD) and SqCC or HGD. The decision tree model constructed using the p53 and Ki-67 expression patterns classified epithelial lesions into ND, LGD, and group 2, including HGD or SqCC, with an accuracy and AUC of 75% and 0.87, respectively. The integrated diagnosis had a better correlation with near perfect agreement (weighted kappa 0.92, unweighted kappa 0.88). The patterns HI and LS for p53 were confirmed to be correlated with missense mutations and nonsense/frameshift mutations, respectively. A predictive model for diagnosis was developed based on the correlation between TP53 mutation and p53 expression patterns. These results indicate that the scoring system based on p53 and Ki-67 expression patterns can differentiate epithelial lesions, especially in cases when the morphological features are ambiguous.

Primary cardiac sarcomas: A clinicopathologic study in a single institution with 25 years of experience with an emphasis on MDM2 expression and adjuvant therapy for prognosis.

BACKGROUND: Primary cardiac sarcomas are rare and their clinicopathologic features are heterogeneous. Among them, particularly intimal sarcoma is a diagnostic challenge due to nonspecific histologic features. Recently, MDM2 amplification reported to be a characteristic genetic event in the intimal sarcoma. In this study, we aimed to identify the types and incidence of primary cardiac sarcomas that occurred over 25 years in tertiary medical institutions, and to find clinicopatholgical significance through reclassification of diagnoses using additional immunohistochemistry (IHC). METHODS: We reviewed the primary cardiac sarcoma cases between January 1993 and June 2018 at Asan Medical Center, South Korea, with their clinicopathologic findings, and reclassified the subtypes, especially using IHC for MDM2 and then, analyzed the significance of prognosis. RESULTS: Forty-eight (6.8%) cases of a primary cardiac sarcoma were retrieved. The tumors most frequently involved the right atrium (n = 25, 52.1%), and the most frequent tumor subtype was angiosarcoma (n = 23, 47.9%). Seven cases (53.8%) were newly reclassified as an intimal sarcoma by IHC for MDM2. Twenty-nine (60.4%) patients died of disease (mean, 19.8 months). Four patients underwent a heart transplantation and had a median survival of 26.8 months. This transplantation group tended to show good clinical outcomes in the earlier stages, but this was not statistically significant (p = 0.318). MDM2 positive intimal sarcoma showed the better overall survival (p = 0.003) than undifferentiated pleomorphic sarcoma. Adjuvant treatment is beneficial for patient survival (p < 0.001), particularly in angiosarcoma (p < 0.001), but not in intimal sarcoma (p = 0.154). CONCLUSION: Our study supports the use of adjuvant treatment in primary cardiac sarcoma, as it was associated with a significantly better overall survival rate. Further consideration of tumor histology may be important in determining the optimal use of adjuvant treatment for different types of sarcomas. Therefore, accurate diagnosis by MDM2 test is important condsidering patient's prognosis and treatment.

The Efficacy of Scalp Nerve Block in Postoperative Pain Management after Microvascular Decompression: A Randomized Clinical Trial.

The scalp nerve block, created by injecting local anesthetics around the scalp nerves, is reported to effectively reduce pain after surgery. In this study, we evaluated the efficacy of scalp nerve block in patients with hemifacial spasm (HFS) undergoing microvascular decompression (MVD). Seventy-four patients who underwent MVD for HFS were enrolled. The block group received scalp nerve block with 0.5% ropivacaine before surgery. The primary outcome was cumulative dose of rescue analgesics 24 h postoperatively. The secondary outcomes were included pain scores, postoperative antiemetic consumption, and Quality of Recovery-15 scale. The cumulative dose of rescue analgesics at 24 h postoperatively was not significantly different between the two groups (4.80 ± 3.64 mg vs. 5.92 ± 3.95 mg, p = 0.633). However, the pain score was significantly reduced in the block group at 6, 12, and 24 h postoperatively. Postoperative antiemetic consumption was lower in the block group than the control group at 12 h. There were no significant differences between the two groups for other secondary outcomes. In MVD for HFS, a preoperative scalp nerve block might reduce postoperative pain in the early postoperative period, but a larger study using a multimodal approach is needed to confirm the efficacy of a scalp block.

Comparison of postoperative analgesic effects of erector spinae plane block and quadratus lumborum block in laparoscopic liver resection: study protocol for a randomized controlled trial.

BACKGROUND: Compared with open surgery, laparoscopic liver resection is a minimally invasive surgical technique. However, a number of patients experience moderate-to-severe postoperative pain after laparoscopic liver resection. This study aims to compare the postoperative analgesic effects of erector spinae plane block (ESPB) and quadratus lumborum block (QLB) in patients undergoing laparoscopic liver resection. METHODS: One hundred and fourteen patients undergoing laparoscopic liver resection will be randomly allocated to three groups (control, ESPB, or QLB) in a 1:1:1 ratio. In the control group, participants will receive systemic analgesia consisting of regular NSAIDs and fentanyl-based patient-controlled analgesia (PCA) according to the institutional postoperative analgesia protocol. In the two experimental groups (ESPB or QLB group), the participants will receive preoperative bilateral ESPB or bilateral QLB in addition to systemic analgesia according to the institutional protocol. ESPB will be performed at the 8th thoracic vertebra level with ultrasound guidance before surgery. QLB will be performed in the supine position on the posterior plane of the quadratus lumborum with ultrasound guidance before surgery. The primary outcome is cumulative opioid consumption 24 h after surgery. Secondary outcomes are cumulative opioid consumption, pain severity, opioid-related adverse events, and block-related adverse events at predetermined time points (24, 48, and 72 h after surgery). Differences in plasma ropivacaine concentrations in the ESPB and QLB groups would be investigated, and the quality of postoperative recovery among the groups will be compared. DISCUSSION: This study will reveal the usefulness of ESPB and QLB in terms of postoperative analgesic efficacy and safety in patients undergoing laparoscopic liver resection. Additionally, the study results will provide information on the analgesic superiority of ESPB versus QLB in the same population. TRIAL REGISTRATION: Prospectively registered with the Clinical Research Information Service on August 3, 2022; KCT0007599.

Comparison of the perfusion index as an index of noxious stimulation in monitored anesthesia care of propofol/remifentanil and propofol/dexmedetomidine: a prospective, randomized, case-control, observational study.

BACKGROUND: Dexmedetomidine, one of the sedatives, has an analgesic effect. We aimed to investigate postoperative analgesia with dexmedetomidine as adjuvants for procedural sedation using perfusion index (PI). METHODS: In this prospective, randomized, case-control, observational study, 72 adult patients, 19-70 years, who were scheduled for chemoport insertion under monitored anesthesia care were performed. According to the group assignment, remifentanil or dexmedetomidine was simultaneously infused with propofol. The primary outcome was PI 30 min after admission to the post anesthesia care unit (PACU). And, pain severity using numerical rating scale (NRS) score and the relationship between NRS score and PI were investigated. RESULTS: During PACU staying, PI values were significantly different between the two groups PI values at 30 min after admission to the PACU were 1.3 (0.9-2.0) in the remifentanil group and 4.5 (2.9-6.8) in the dexmedetomidine group (median difference, 3; 95% CI, 2.1 to 4.2; P < 0.001). The NRS scores at 30 min after admission to the PACU were significantly lower in the dexmedetomidine group (P = 0.002). However, there was a weak positive correlation between NRS score and PI in the PACU (correlation coefficient, 0.188; P = 0.01). CONCLUSION: We could not find a significant correlation between PI and NRS score for postoperative pain control. Using PI as a single indicator of pain is insufficient. TRIAL REGISTRATION: Clinical Trial Registry of Korea, https://cris.nih.go.kr : KCT0003501, the date of registration: 13/02/2019.

Changes in bispectral index and patient state index during sugammadex reversal of neuromuscular blockade under steady-state sevoflurane anesthesia.

Few studies have investigated the changes in patient state index (PSI) and bispectral index (BIS) in response to abrupt increase in electromyographic (EMG) activity. These were performed using intravenous anesthetics or reversal agents for neuromuscular blockade (NMB) other than sugammadex. We compared the changes in BIS and PSI values caused by the sugammadex reversal of NMB during steady-state sevoflurane anesthesia. We enrolled 50 patients with American Society of Anesthesiologists physical status 1 and 2. At the end of the surgery, we administered 2 mg kg-1 sugammadex while maintaining sevoflurane for a 10-min study period. The changes in BIS and PSI from baseline (T0) to train of four ratio of 90% were not significantly different (median difference 0; 95% CI - 3 to 2; P = 0.83), neither were the changes in BIS and PSI values from T0 to their maximum values (median difference 1; 95% CI - 1 to 4; P = 0.53). Maximum BIS and PSI were significantly higher than their baseline values (median difference 6; 95% CI 4-9; P < 0.001 and median difference 5; 95% CI 3-6; P < 0.001, respectively). We found weak positive correlations between BIS and BIS-EMG (r = 0.12, P = 0.01), as well as PSI and PSI-EMG (r = 0.25, P < 0.001). Both PSI and BIS were affected to some extent by EMG artifacts after sugammadex administration.

The Effect of Intrathecal Morphine on Postoperative Opioid Consumption in Patients Undergoing Abdominal Surgery for Gynecologic Malignancy: A Randomized Sham-Controlled Trial.

BACKGROUND: Surgery for gynecologic malignancy via midline-laparotomy leads to severe postoperative pain. Adequate pain control while sparing opioid consumption does offer benefits in postoperative complications and recovery. Intrathecal morphine (ITM) provides simple and effective analgesia. In this randomized trial, we compared postoperative opioid consumption in patients who received either ITM or a sham procedure. METHODS: We enrolled 68 adult patients undergoing open gynecologic oncology surgery from June 2021 to November 2021. They were randomly allocated to the ITM group (ITM; 200 µg injection) or sham group (sham procedure) to achieve a final 1:1 ratio between groups. We compared opioid consumption and pain severity during 72 hours after surgery. The variables regarding postoperative recovery and patient-centered outcomes were collected. The primary outcome is cumulative intravenous (IV) opioid consumption 24 hours after surgery. RESULTS: The median (interquartile range) cumulative IV opioid consumption during 24 hours after surgery was 18 mg (12-29) in the ITM group and 36 mg (27-42) in the sham group (median difference, 13; 95% confidence interval, 7.2-20.7; P < .001). Patient satisfaction regarding pain control was statistically significantly higher in the ITM group than in the sham group at postoperative 24 and 48 hours ( P < .001 and P = .005, respectively). There were no significant differences in the variables associated with postoperative recovery and frequency of complications requiring treatment. CONCLUSIONS: ITM is a safe and effective analgesic method after curative intent laparotomy for gynecologic malignancy. ITM provides better pain relief, reduces opioid consumption, and improves patient satisfaction without additional evident adverse events.

Remimazolam dose for successful insertion of a supraglottic airway device with opioids: a dose-determination study using Dixon's up-and-down method.

PURPOSE: Remimazolam, an ultra-short-acting benzodiazepine, was recently approved in numerous jurisdictions as an induction drug for general anesthesia. We aimed to determine the doses of remimazolam that would allow placement of a supraglottic airway device (SGD) in 50% and 95% of nonparalyzed patients (ED50 and ED95). METHODS: In this prospective study, 30 American Society of Anesthesiology Physical Status I-II grade female patients scheduled for hysteroscopic surgery were enrolled. Anesthesia was induced with 1 µg·kg-1 of fentanyl and continuous infusion of remimazolam without neuromuscular blockade. An i-gel® SGD was inserted 2.5 min after the start of remimazolam infusion. We used Dixon's up-and-down method and isotonic regression to determine the ED50 and ED95 of remimazolam for insertion of an SGD. RESULTS: Twenty-eight patients were included in the final analysis. The ED50 and ED95 of remimazolam required for successful i-gel insertion were 8.8 mg·kg-1·hr-1 (95% confidence interval [CI], 6.3 to 10.6) and 10.7 mg·kg-1·hr-1 (95% CI, 10.6 to 11.7), respectively. A nonfully relaxed jaw was found in 7/13 patients (54%) in the success group and 14/15 patients (93%) in the failure group (difference in proportions, 40%; 95% CI, 7 to 65; P = 0.02). Bucking or other movements during SGD insertion only occurred in the failure group (11/15, 73%). CONCLUSION: In 95% of nonparalyzed female patients undergoing hysteroscopy, 10.7 mg·kg-1·hr-1 of remimazolam with 1 µg·kg-1 of fentanyl facilitates i-gel insertion. Remimazolam showed a high incidence of poor jaw relaxation and bucking or other movements during SGD insertion. STUDY REGISTRATION: Clinical Trial Registry of the Republic of Korea (KCT0006527, https://cris.nih.go.kr ; registered 1 September 2021; principal investigator: Ji Seon Jeong).

RéSUMé: OBJECTIF: Le remimazolam, une benzodiazépine à action ultra-brève, a récemment été approuvé dans de nombreuses juridictions comme agent d'induction pour l'anesthésie générale. Notre objectif était de déterminer les doses de remimazolam qui permettraient l'insertion d'un dispositif supraglottique (DSG) chez 50 % et 95 % des patients non paralysés (DE50 et DE95). MéTHODE: Dans cette étude prospective, 30 patientes de statut physique I-II selon l'American Society of Anesthesiology devant bénéficier d'une chirurgie hystéroscopique ont été recrutées. L'anesthésie a été induite avec 1 µg·kg−1 de fentanyl et une perfusion continue de remimazolam sans bloc neuromusculaire. Un DSG i-gel® a été inséré 2,5 minutes après l'amorce de la perfusion de remimazolam. Nous avons utilisé la méthode de l'escalier de Dixon et la régression isotonique pour déterminer la DE50 et DE95 de remimazolam pour l'insertion d'un DSG. RéSULTATS: Vingt-huit patientes ont été incluses dans l'analyse. Les DE50 et DE95 du remimazolam requises pour une insertion réussie de l'i-gel était de 8,8 mg·kg−1·h−1 (intervalle de confiance [IC] à 95 %, 6,3 à 10,6) et 10,7 mg·kg−1·h−1 (IC 95 %, 10,6 à 11,7), respectivement. Une mâchoire non complètement détendue a été observée chez 7 patientes sur 13 (54 %) dans le groupe d'intubation réussie et chez 14/15 patientes (93 %) dans le groupe d'échec d'intubation (différence de proportions, 40 %; IC 95 %, 7 à 65; P = 0,02). Le fléchissement ou d'autres mouvements pendant l'insertion du DSG ne se sont produits que dans le groupe d'échec de l'induction (11/15, 73 %). CONCLUSION: Chez 95 % des patientes non paralysées bénéficiant d'une hystéroscopie, 10,7 mg·kg−1·h−1 de remimazolam avec 1 µg·kg−1 de fentanyl ont facilité l'insertion d'un dispositif i-gel. Le remimazolam a montré une incidence élevée de mauvaise relaxation de la mâchoire et de fléchissement ou d'autres mouvements lors de l'insertion du DSG. ENREGISTREMENT DE L'éTUDE: Registre des essais cliniques de la République de Corée (KCT0006527, https://cris.nih.go.kr ; enregistrée le 1er septembre 2021; chercheur principal : Ji Seon Jeong).

Development and validation of an analytical method using liquid chromatography-tandem mass spectrometry for the therapeutic drug monitoring of seven cardiovascular drugs in clinical usage.

Therapeutic drug monitoring (TDM) of cardiovascular drugs is essential to improve treatment efficacy and minimize toxicity because of the usage of multiple drugs with a very limited therapeutic range and the high pharmacokinetic variation in patients. We developed and validated a reliable and economical liquid chromatography/tandem mass spectrometry (LC-MS/MS) method for the determination of seven cardiovascular drugs-procainamide, lidocaine, quinidine, deslanoside, digoxin, atorvastatin, and digitoxin-for clinical usage. Serum samples were prepared by simple protein precipitation with an organic solvent consisting of acetonitrile and methanol (2:1 v/v) and analyzed under optimized LC-MS/MS conditions. The chromatographic separations were accomplished within 15 min on a reversed-phase C18 column with a gradient elution of aqueous solvent and acetonitrile while maintaining 0.1 (v/v) % formic acid and 2 mM ammonium formate. The optimized MS/MS conditions in ESI-positive mode offered sufficient sensitivity for the seven cardiovascular drugs (LOQs between 0.5 and 1 ng/mL). This method was fully validated including linearity, selectivity, accuracy, precision, carry-over, and matrix effects. Additionally, stability under several conditions was tested to determine how to handle the standard solutions and serum samples. The seven cardiovascular drugs, simultaneously, were precisely and accurately analyzed in intra- and inter-day assays (RSD < 6 % and recovery between 96.3 and 102.8 %) using only two isotope-labeled internal standards (lidocaine-(diethyl-d10) and digoxin-21, 21, 22-d3). The presented method also showed good accuracy in analyzing the seven drugs in hyperlipidemia, hyperalbuminemia, and hyperglycemia serum, allowing it to be recommended as a common and routine analysis method for cardiovascular drugs in clinical practice.

Comparison of two sizes of GlideScope® blades in tracheal intubation of infants: a randomised clinicaltrial.

BACKGROUND: The appropriate size of GlideScope® blade for tracheal intubation in neonates and premature infants has not been established. We evaluated the impact of the size of the GlideScope® blade on the time taken for intubation in infants weighing 2.5-3.6 kg. METHODS: Sixty infants weighing 2.5-3.6 kg were randomly assigned to use of the size 1 blade (n=30) or the size 2 blade (n=30). The primary outcome was the time taken to intubate. Components related to the laryngoscopic view which could affect the duration of the intubating process were also analysed. RESULTS: The time required for tracheal intubation was shorter with the size 2 blade than with the size 1 blade (16 [14-20] s vs 22 [18-25] s, P=0.002; median difference=-5; 95% confidence interval, -7 to -2). The rate at which the tip of the tracheal tube was located at the centre of the laryngeal inlet was higher with the size 2 blade than with the size 1 blade (83% vs 40%, P<0.001). Correlation analysis indicated that the time required to find the tip of the tube was related to how far the lower border of the arytenoid cartilages was located from the mid-horizontal line of the monitor (r=0.28, P=0.033). CONCLUSION: Use of the size 2 blade significantly reduced the time required to intubate the trachea, compared with the size 1 GlideScope® blade in infants. CLINICAL TRIAL REGISTRATION: KCT 0003867.

Development of Certified Reference Material for Amino Acids in Dried Blood Spots and Accuracy Assessment of Disc Sampling.

To achieve the measurement reliability of amino acids used as diagnostic markers in clinical fields, establishing a reference measurement system is required, in which certified reference materials (CRMs) are an essential step in the hierarchy of measurement traceability. This study describes the development of dried blood spot (DBS) CRMs for amino acid analysis with complete measurement traceability to the International System of Units (SI). Six essential amino acids─proline, valine, isoleucine, leucine, phenylalanine, and tyrosine─were analyzed using isotope-dilution liquid chromatography-mass spectrometry (ID-MS). For minimizing measurement bias and uncertainty overestimation, whole spots with 50 µL of whole blood were adopted in the certification. The between-spot homogeneities by whole spot sampling were lower than 2.1%. The relative expanded uncertainties of the six amino acids in the developed DBS CRMs were lower than 5.7% at 95% confidence. The certified values are traceable to SI through both gravimetric preparation and the primary method in certification, ID-MS. Comparison among DBS testing laboratories revealed discrepancies between the whole spot and disc sampling methods. The actual sampling volume was accurately estimated by weighing, which revealed the possibility of underestimation in routine DBS testing. The candidate CRMs can support the standardization of DBS testing for amino acids through the qualification and validation of many kinds of measurement procedures to compensate the measurement bias caused by matrix-specific sampling error.

Measurement comparability of insulin assays using conventional immunoassay kits.

BACKGROUND: The standardization of measurement aims to achieve comparability of results regardless of the analytical methods and the laboratory where analyses are carried out. In this paper, a comparison of results from several immunoassay-based insulin analysis kits is described, and the steps necessary to improve comparability are discussed. METHODS: Four manual enzyme-linked immunosorbent assay (ELISA) kits produced by Mercodia, Alpco, Epitope Diagnostics, and Abcam, and three automated chemiluminescent (CLIA) insulin assay kits (Siemens Centaur XP, Unicel Dxl800, Cobas e801) were compared by analyzing human serum samples and certified reference materials for human insulin. RESULTS: The seven evaluated assay kits showed substantial discrepancies in the results, with relative standard deviation ranges between 1.7% and 23.2%. We find that the traceability chains and the unit conversion factors are not yet harmonized, and current reference materials for insulin are not applicable for immunoassay-based method validation due to the use of different matrices. CONCLUSIONS: The findings suggest the need to fine tune insulin analysis methods, measurement traceability, and any conversion factor used in post-analysis steps in accordance with the necessity for standardization.

Risk factors associated with repeated epidural blood patches using autologous blood.

Background: An epidural blood patch (EBP) is a procedure to treat intracranial hypotension that does not respond to conservative treatment. EBPs are commonly repeated when the symptoms persist. In this study, we used a large single-center retrospective cohort and evaluated the factors associated with repeated EBPs. Methods: From January 2010 to December 2020, a total of 596 patients were treated with EBPs for intracranial hypotension. We evaluated the factors associated with repeated EBPs in the entire population, in patients with spontaneous intracranial hypotension (SIH), and in those with available myelographies. Results: In a total of 596 patients, 125 (21.1%) patients required repeated EBPs, and 96/278 (34.5%) in SIH and 29/314 (9.2%) in iatrogenic population. In patients with SIH, international normalized ratio (INR) and cerebrospinal fluid (CSF) leakage on myelographies consistently exhibited significant associations (odds ratio [OR], 1.38; 95% confidence interval [CI], 1.02-1.87; P = 0.043 and OR, 2.18; 95% CI, 1.28-3.69; P = 0.004). In patients with iatrogenic injury, INR and CSF leakage on myelogram did not show difference in repeated EBPs. Conclusions: Repeated EBPs may be more frequently required in patients with SIH. Prolonged INR and CSF leakage were associated with repeated EBPs in patient with SIH. Further studies are needed to determine factors associated with repeated EBP requirements.