Determination of lysophosphatidylcholine using peroxidase-mimic PVP/PtRu nanozyme.

Lysophosphatidylcholine (LPC) can be used as a biomarker for diseases such as cancer, diabetes, atherosclerosis, and sepsis. In this study, we demonstrated the ability of nanozymes to displace the natural derived enzyme in enzyme-based assays for the measurement of LPC. Synthesized polyvinylpyrrolidone-stabilized platinum-ruthenium nanozymes (PVP/PtRu NZs) had a uniform size of 2.48 ± 0.24 nm and superb peroxidase-mimicking activity. We demonstrated that the nanozymes had high activity over a wide pH and temperature range and high stability after long-term storage. The LPC concentration could be accurately analyzed through the absorbance and fluorescence signals generated by the peroxidation reaction using the synthesized nanozyme with substrates such as 3,3',5,5'-tetramethylbenzidine (TMB) and 10-acetyl-3,7-dihydroxyphenoxazine (Ampliflu™ Red). LPC at a concentration of 0-400 µM was used for the analysis, and the coefficient of determination (R2) was 0.977, and the limit of detection (LOD) was 23.1 µM by colorimetric assay. In the fluorometric assay, the R2 was 0.999, and the LOD was 8.97 µM. The spiked recovery values for the determination of LPC concentration in human serum samples were 102-115%. Based on these results, we declared that PVP/PtRu NZs had an ability comparable to that of the native enzyme horseradish peroxidase (HRP) in the enzyme-based LPC detection method.

Body Boundary Measurement Using Multiple Line Lasers for a Focused Microwave Thermotherapy System: A Proof-of-Concept Study.

A focused microwave thermotherapy system for non-invasively treating cancerous tumors has recently been actively developed. To accurately focus on the target location, the system needs information about the patient's body boundary. However, a water bolus is placed between the human body and the microwave applicators to allow the microwave to penetrate the body more easily and cool the body's skin. The structural configuration makes it difficult to measure the body boundary. In this paper, we present a body boundary measurement method using multiple line lasers and cameras for the application of a focused microwave thermotherapy system. Even with a lack of acquired boundary data, a completely closed boundary line can be reconstructed. In addition, real-time movement tracking is possible as it can be measured quickly, even in situations where the patient is moving, such as breathing and wriggling. The performance is verified with several indicators in a water-filled experimental testbed.

Electrospun Nanofibrous Membrane-Based Colorimetric Device for Rapid and Simple Screening of Amphetamine-Type Stimulants in Drinks.

With the growth of drug-facilitated crimes, prevention has become increasingly important. Although various drug detection technologies exist, most focus on postconsumption detection. However, the prevention of drug-facilitated crimes requires technology for the quick and easy detection of amphetamine-type stimulants (ATSs) before ingestion. Herein, drug screening kits (DSKs) were developed for the simple detection of ATSs in drinks. The DSKs consisted of polydiacetylene nanofiber-based paper sensors fabricated by electrospinning with 10,12-pentacosadiynoic acid (PCDA) and PCDA-dopamine as sensing materials that can bind ATSs via hydrogen bonding and π-π interactions. Dropping a drink on the DSK provided an immediate visual indication of the presence of ATSs. When ATSs were present in the drink, the color of the DSK clearly changed from blue to red, with the increase in red intensity being more than twofold greater than that observed when water alone was tested. Notably, the result could be confirmed by the naked eye without any analytical instrumentation. A color change indicating the presence of ATSs was successfully observed in various alcoholic and nonalcoholic drinks. These results indicate the potential of DSKs for preventing drug-facilitated crimes caused by unwanted drug intake.

Mesoporous platinum nanoparticles as a peroxidase mimic for the highly sensitive determination of C-reactive protein.

The generation of a mesoporous structure in platinum nanoparticles can effectively enhance physical and chemical properties. In this study, mesoporous platinum nanoparticles (MPNs) were synthesized by a soft template-mediated one-pot chemical method. To develop a mesoporous structure, Pluronic F-127 was employed. The Pluronic F-127 surfactant forms self-assembled micelles, and the micelles act as the pore-directing agents in the synthesis of nanoparticles. Scanning electron microscopy results revealed that the MPN had a uniform size of 70 nm on average and a distinct mesoporous structure. The development of a concave mesoporous structure on the surface of the MPNs can increase the surface area and facilitate the efficient transport of reactants. The synthesized MPNs exhibited peroxidase-like activity. Furthermore, the MPNs showed excellent catalytic efficiency compared to HRP, due to the high surface area derived from the presence of the mesoporous structure. The peroxidase-like MPNs were applied to the enzyme-linked immunosorbent assay (ELISA) of C-reactive protein (CRP). The MPN-based ELISA exhibited sensitive CRP detection in the range from 0.24 to 7.8 ng/mL with a detection limit of 0.13 ng/mL. Moreover, the recoveries of the CRP concentrations in spiked human serum were 98.6% and 102%. These results demonstrate that as a peroxidase mimic, the MPNs can replace the natural enzymes in conventional ELISA for sensitive CRP detection.

FRET-based hACE2 receptor mimic peptide conjugated nanoprobe for simple detection of SARS-CoV-2.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has led to a pandemic of acute respiratory disease, namely coronavirus disease (COVID-19). This disease threatens human health and public safety. Early diagnosis, isolation, and prevention are important to suppress the outbreak of COVID 19 given the lack of specific antiviral drugs to treat this disease and the emergence of various variants of the virus that cause breakthrough infections even after vaccine administration. Simple and prompt testing is paramount to preventing further spread of the virus. However, current testing methods, namely RT-PCR, is time-consuming. Binding of the SARS-CoV-2 spike (S) glycoprotein to human angiotensin-converting enzyme 2 (hACE2) receptor plays a pivotal role in host cell entry. In the present study, we developed a hACE2 mimic peptide beacon (COVID19-PEB) for simple detection of SARS-CoV-2 using a fluorescence resonance energy transfer system. COVID19-PEB exhibits minimal fluorescence in its ''closed'' hairpin structure; however, in the presence of SARS-CoV-2, the specific recognition of the S protein receptor-binding domain by COVID19-PEB causes the beacon to assume an ''open'' structure that emits strong fluorescence. COVID19-PEB can detect SARS-CoV-2 within 3 h or even 50 min and exhibits strong fluorescence even at low viral concentrations, with a detection limit of 4 × 103 plaque-forming unit/test. Furthermore, in SARS-CoV-2-infected patient samples confirmed using polymerase chain reaction, COVID19-PEB accurately detected the virus. COVID19-PEB could be developed as a rapid and accurate diagnostic tool for COVID-19.

Functionalized ultra-fine bimetallic PtRu alloy nanoparticle with high peroxidase-mimicking activity for rapid and sensitive colorimetric quantification of C-reactive protein.

The in situ synthesis is reported of citric acid-functionalized ultra-fine bimetallic PtRu alloy nanoparticles (CA@PtRu ANPs) through a simple one-pot wet chemical method. The cost-efficient CA@PtRu ANPs with an average diameter of 3.2 nm revealed to have enhanced surface area, peroxidase-like activity, high stability, and adequate availability of functional groups to bind biomolecules. Along with nanoparticle surface area, the surface charge has also significantly affected the peroxidase-like activity and the colloidal suspension stability. As an excellent immobilization matrix and peroxidase mimic, the CA@PtRu ANPs were utilized to develop non-enzymatic colorimetric immunoassay for rapid, selective, and sensitive quantification of C-reactive protein (CRP) biomarkers. In this immunoassay, CA@PtRu ANPs serve as enzyme mimic that significantly amplifies the color signals, and amine-functionalized silica-coated magnetic microbeads (APTES/SiO2@Fe3O4) act as CRP-recognizing capture probes. The absorbance curves of colorimetric immunoassay were measured in wavelengths between 550 and 750 nm, and the maximum absorbance at 652 nm was used to establish a linear relationship between absorbance and CRP concentrations. The developed colorimetric immunoassay showed rapid and sensitive quantification of CRP levels from 0.01 to 180 µg mL-1 with a LOD of 0.01 µg mL-1. Moreover, the mean recovery of CRP from spiked human serum samples lies between 97 and 109% (n = 3), which indicates that the proposed nanozyme-linked immunoassay has the potential to be used in rapid point-of-care applications.

Learning curve of trans-sacral epiduroscopic laser decompression in herniated lumbar disc disease.

BACKGROUND: Trans-sacral epiduroscopic laser decompression (SELD) using slender epiduroscope and a holmium YAG laser is one of the minimally invasive surgical options for lumbar disc herniation. However, the learning curve of SELD and the effect of surgical proficiency on clinical outcome have not yet been established. We investigated patients with lumbar disc herniation undergoing SELD to report the clinical outcome and learning curve. METHODS: Retrospective analysis of clinical outcome and learning curve were performed at a single center from clinical data collected from November 2015 to November 2018. A total of 82 patients who underwent single-level SELD for lumbar disc herniation with a minimum follow-up of 6.0 months were enrolled. Based on the findings that the cut-off of familiarity was 20 cases according to the cumulative study of operation time, patients were allocated to two groups: early group (n = 20) and late group (n = 62). The surgical, clinical, and radiological outcomes were retrospectively evaluated between the two groups to analyze the learning curve of SELD. RESULTS: According to linear and log regression analyses, the operation time was obtained by the formula: operation time = 58.825-(0.181 × [case number]) (p < 0.001). The mean operation time was significantly different between the two groups (mean 56.95 min; 95% confidence interval [CI], 49.12-64.78 in the early group versus mean 45.34 min; 95% CI, 42.45-48.22 in the late group; p = 0.008, non-parametric Mann-Whitney U test). Baseline characteristics, including demographic data, clinical factors, and findings of preoperative magnetic resonance imaging, did not differ between the two groups. Also, there was no significant difference in terms of surgical outcomes, including complication and failure rates, as well as clinical and radiological outcomes between the two groups. CONCLUSION: The learning curve of SELD was not as steep as that of other minimally invasive spinal surgery techniques, and the experience of surgery was not an influencing factor for outcome variation.

Au nanoparticle-hydrogel nanozyme-based colorimetric detection for on-site monitoring of mercury in river water.

A sensitive on-site mercury sensing platform was developed for simple and effective monitoring of mercury levels in the field. The simple and practical mercury detection system was designed by integrating an Au nanoparticle-PEG hydrogel block nanozyme (Au-HBNz) into a polymer film-based colorimetric device. Upon addition of Hg2+ ions, Au-HBNz exhibited excellent peroxidase-like activity, catalyzing the oxidation of 3,3',5,5'-tetramethylbenzidine into a blue-colored product, which has a maximum absorbance at 652 nm. The resulting color intensity change was evaluated using a smartphone for simple and rapid Hg2+ detection with a broad detection range (0.008-20 µg∙mL-1) and a linear concentration-response relationship (R2 = 0.96). The detection limit (1.10 ng∙mL-1) was lower than the maximum permissible Hg2+ levels in drinking water set by the World Health Organization (6 ng∙mL-1) and U.S. Environmental Protection Agency (2 ng∙mL-1). The recoveries of Hg2+ determination in river water by spiking Hg2+ samples ranged from 92 to 106%, which indicated high validity and applicability of the Hg2+ detection system for field measurements. Thus, the developed sensor enables highly selective and efficient real-time monitoring of Hg2+.

Biomechanics Differ for Individuals With Similar Self-Reported Characteristics of Patellofemoral Pain During a High-Demand Multiplanar Movement Task.

CONTEXT: Patellofemoral pain (PFP) is often categorized by researchers and clinicians using subjective self-reported PFP characteristics; however, this practice might mask important differences in movement biomechanics between PFP patients. OBJECTIVE: To determine whether biomechanical differences exist during a high-demand multiplanar movement task for PFP patients with similar self-reported PFP characteristics but different quadriceps activation levels. DESIGN: Cross-sectional design. SETTING: Biomechanics laboratory. PARTICIPANTS: A total of 15 quadriceps deficient and 15 quadriceps functional (QF) PFP patients with similar self-reported PFP characteristics. INTERVENTION: In total, 5 trials of a high-demand multiplanar land, cut, and jump movement task were performed. MAIN OUTCOME MEASURES: Biomechanics were compared at each percentile of the ground contact phase of the movement task (α = .05) between the quadriceps deficient and QF groups. Biomechanical variables included (1) whole-body center of mass, trunk, hip, knee, and ankle kinematics; (2) hip, knee, and ankle kinetics; and (3) ground reaction forces. RESULTS: The QF patients exhibited increased ground reaction force, joint torque, and movement, relative to the quadriceps deficient patients. The QF patients exhibited: (1) up to 90, 60, and 35 N more vertical, posterior, and medial ground reaction force at various times of the ground contact phase; (2) up to 4° more knee flexion during ground contact and up to 4° more plantarflexion and hip extension during the latter parts of ground contact; and (3) up to 26, 21, and 48 N·m more plantarflexion, knee extension, and hip extension torque, respectively, at various times of ground contact. CONCLUSIONS: PFP patients with similar self-reported PFP characteristics exhibit different movement biomechanics, and these differences depend upon quadriceps activation levels. These differences are important because movement biomechanics affect injury risk and athletic performance. In addition, these biomechanical differences indicate that different therapeutic interventions may be needed for PFP patients with similar self-reported PFP characteristics.

Pilot study: Differences in echo intensity ratios between ulnar and median innervated muscles in ulnar neuropathy.

BACKGROUND: This study evaluated muscle echo intensity (EI) ratio in patients with ulnar neuropathy at the elbow (UNE) and healthy controls. METHODS: In this prospective study, 28 patients with electrodiagnostically confirmed unilateral UNE and 12 healthy controls were ultrasonographically assessed for EI ratios of the hypothenar and thenar muscles. The affected and unaffected hands between the UNE patients and controls and patient subgroups (subdivided according to electrodiagnostic severity) were compared to determine any significant differences. RESULTS: In patients with UNE, the EI ratio of the hypothenar to thenar muscles was significantly higher for the affected side than for the unaffected side (1.08 ± 0.11 and 0.97 ± 0.18, respectively) or the control group (0.95 ± 0.05). A significant difference in the EI ratio was observed among the subgroups (mild vs. severe subgroup, P < 0.01). CONCLUSIONS: Ultrasonographic EI measurement may be a useful parameter in the evaluation and screening of UNE.

Altered movement strategies during jump landing/cutting in patients with chronic ankle instability.

Centrally mediated changes in sensorimotor function have been reported in patients with chronic ankle instability (CAI). However, little is known regarding supraspinal/spinal adaptations during lower-extremity dynamic movement during a multiplanar, single-leg landing/cutting task. The purpose of this study was to investigate the effect of CAI on landing/cutting neuromechanics, including lower-extremity kinematic, electromyography (EMG) activation, and ground reaction force (GRF) characteristics. One hundred CAI patients and 100 matched healthy controls performed five trials of a jump landing/cutting task. Sagittal- and frontal-plane ankle, knee and hip kinematics, EMG activation in eight lower-extremity muscles, and 3D GRF were collected during jump landing/cutting. Functional analyses of variance (FANOVA) were used to evaluate between-group differences for dependent variables throughout the entire ground contact of the task. Relative to the control group, the CAI group revealed (a) reduced dorsiflexion, increased knee and hip flexion angles, (b) increased inversion and hip adduction angles, (c) increased EMG activation of medial gastrocnemius, peroneus longus, adductor longus, vastus lateralis, gluteus medius, and gluteus maximus, and (d) increased posterior and vertical GRF during initial landing, and reduced medial, posterior, and vertical GRF during mid-landing and mid-cutting. CAI patients demonstrated alterations in landing/cutting movement strategies as demonstrated by a higher susceptibility of foot placement for lateral ankle sprains, and more flexed positions of the knee and hip with higher EMG activation of knee and hip extensors to modulate GRF to compensate for the unstable ankle. This apparent compensation may be due to mechanical (limited dorsiflexion angle) and/or sensorimotor deficits in the ankle.

Binary code DOE optimization for speckle suppression in a laser display.

Using a laser light source in imaging devices provides a wide color gamut, high brightness, resolution, and efficiency. At the same time, it creates a speckle pattern that deteriorates the image quality. This paper is related to the application of the moving binary code diffractive optical element (DOE) for speckle suppression in a laser display. Analytical optimization of DOE parameters is made in this paper. The optimal DOE pitch is found analytically. Limitation of the DOE code length is shown, and the highest possible code length is estimated. Application of the compound Barker code for the DOE design is suggested. As an alternative, the M-sequence and minimum peak side-lobe codes are considered. The expected residual speckle contrast ratio after application of those codes is estimated for the number of codes. A comparison of the different codes is done, and recommendations for speckle suppression DOE design are provided.

Transient midventricular ballooning syndrome with thrombus post pericardiocentesis in a patient with malignant breast cancer.

One day after pericardiocentesis for pericardial effusion in a patient with malignant breast cancer, the clinical and echocardiographic examination for recurrent dyspnea suggested stress cardiomyopathy with mid left ventricular ballooning and thrombus rather than pericardial decompression syndrome. Physicians should therefore pay attention to the possibility of ventricular dysfunction with thrombus post pericardiocentesis and to differences between stress cardiomyopathy and pericardial decompression syndrome. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:53-57, 2017.

Effect on the H19 gene methylation of sperm and organs of offspring after chlorpyrifos-methyl exposure during organogenesis period.

To elucidate the effect on the H19 gene methylation of sperm and organs in offspring by chlorpyrifos-methyl (CPM) exposure during organogenesis period, CPM was administered at doses of 4 (CPM4), 20 (CPM20), and 100 (CPM100) mg/kg bw/day from 7 days post coitum (d.p.c.) to 17 d.p.c. after mating CAST/Ei (♂) and B6 (♀). Anogenital distance (AGD) was measured at postnatal day (PND) 21. Clinical signs, body weights, feed and water consumption, organs weights, serum hormone values, and H19 methylation level of organ and sperm were measured at PND63. Body weights were significantly lower than control until PND6. AGD was significantly decreased in the CPM100 group in males and increased in the CPM20 group in females. The absolute weights of the thymus and epididymis were significantly increased for males in all of CPM treatment groups. In the CPM20 group, absolute weights of liver, kidney, heart, lung, spleen, prostate gland, and testes were significantly increased. Testosterone concentrations in serum were significantly increased by CPM treatment in males. H19 methylation level of liver and thymus showed decreased pattern in a dose-dependent manner in males. The levels of H19 methylation in sperm were 73.76 ± 7.16% (Control), 57.84 ± 12.94% (CPM4), 64.24 ± 3.79% (CPM20), and 64.24 ± 3.79% (CPM100). Conclusively, CPM exposure during organogenesis period can disrupt H19 methylation in sperm, liver, and thymus and disturb the early development of offspring.

Does botulinum toxin injection site determine outcome in post-stroke plantarflexion spasticity? Comparison study of two injection sites in the gastrocnemius muscle: a randomized double-blind controlled trial.

OBJECTIVE: To determine if botulinum toxin type A injection at the proximal 2/10 and 3/10 of calf length, where the intramuscular nerve endings of the gastrocnemius muscle are densely distributed, is more efficacious in controlling plantarflexion spasticity than injection at distant sites within the same muscle. DESIGN: A double-blind randomized controlled trial. SETTTING: Two rehabilitation centres. SUBJECTS: Forty stroke patients were randomly allocated to two groups. Group A received injection at the proximal 2/10 and 3/10 of calf length, group B at and below the midbelly of the muscle. Both groups received 200 IU of botulinum toxin A and were followed up to eight weeks. MAIN MEASURES: Primary variables were the surface electromyography values recorded during plantarflexion; secondary variables were the Modified Ashworth Scale, Modified Tardieu Scale, clonus scale, 10-metre walking test, ABILOCO and Functional Ambulation Categories. RESULTS: At baseline, the median Modified Ashworth Scale was 2.0 (range,1+ -3.0), and there were no significant differences between the two groups in all the parameters, including spasticity. Compared to baseline, no significant differences between the two groups were detected in all the surface electromyography and clinical parameters at week 8 (P > 0.05). Both groups showed significant improvement of spasticity with a median Modified Ashworth Scale of 1+ (range, 0.0-2.0) at eight weeks. CONCLUSIONS: Botulinum toxin A injection was associated with a significant improvement from baseline to week 8 in both treatment groups, however, no significant difference between the 2 groups was observed, based on the electrophysiological and clinical parameters employed in this study.

Exposure of pregnant mice to chlorpyrifos-methyl alters embryonic H19 gene methylation patterns.

The aim of this study was to identify whether chlorpyrifos methyl (CPM) exposure during pregnancy leads to changes in the methylation patterns of H19 gene. CPM 4, 20, 100 mg/kg bw/day was administered to 4 pregnant mice per group between 7 and 12 days post coitum (d.p.c.). Pregnant mice were killed at 13 d.p.c. The genomic methylation in primordial germ cells (PGCs) and fetal organs (the liver, intestine, and placenta) was examined. Four polymorphism sites in the H19 alleles of maternal (C57BL/6J) and paternal (CAST/Ei) alleles were identified at nucleotide position 1407, 1485, 1566, and 1654. The methylation patterns of 17 CpG sites were analyzed. The methylation level in male and female PGCs was not altered by CPM treatment in the maternal allele H19. The methylation level of the paternal H19 allele was altered in only male PGCs in response to the CPM treatment. The methylation level at a binding site for the transcriptional regulator CTCF2 was higher than that at the CTCF1 binding site in all CPM-treated groups. In the placenta, the aggregate methylation level of H19 was 56.89%in control group. But, those levels were ranged from 47.7% to 49.89% after treatment with increasing doses of CPM. H19 gene from the liver and intestine of 13 d.p.c. fetuses treated with CPM was hypomethylated as compared with controls, although H19 mRNA expression was unaltered. In the placenta, H19 expression was slightly increased in the CPM-treated group, although not significantly. IGF2 expression levels were not significantly changed in the placenta. In conclusion, CPM exposure during pregnancy alters the methylation status of the H19 gene in PGCs and embryonic tissues. We infer that these alterations are likely related to changes in DNA demethylase activity.

Digital therapeutics-based lumbar core exercise for patients with low back pain: A prospective exploratory pilot study.

Objective: This study aimed to implement a digital therapeutics-based approach based on motion detection technology and analyze the clinical results for patients with chronic low back pain (LBP). Methods: A prospective, single-arm clinical trial was conducted with 22 patients who performed mobile app-based sitting core twist exercise for 12 weeks. Clinical outcomes were assessed using the visual analog scale (VAS) for LBP, Oswestry Disability Index-Korean version (K-ODI), and EuroQol-5 dimension 5-level version (EQ-5D-5L) every 4 weeks after the initiation of treatment. Laboratory tests for factors associated with muscle metabolism, plain X-ray for evaluating sagittal balance, and magnetic resonance imaging for calculating cross-sectional area (CSA) of back muscles were performed at pretreatment and 12 weeks post-treatment. Results: The study population included 20 female patients with an average age of 45.77 ± 15.45 years. The clinical outcomes gradually improved throughout the study period in the VAS for LBP (from 6.05 ± 2.27 to 2.86 ± 1.86), K-ODI (from 16.18 ± 6.19 to 8.64 ± 5.58), and EQ-5D-5L (from 11.09 ± 3.24 to 7.23 ± 3.89) (p < 0.001, respectively). The laboratory test results did not show significant changes. Pelvic incidence (from 53.99 ± 9.70° to 50.80 ± 9.20°, p = 0.002) and the mismatch between pelvic incidence and lumbar lordosis (from 8.97± .67° to 5.28 ± 8.57°, p = 0.027) decreased significantly. Additionally, CSA of erector spinae and total back muscles increased by 5.20% (p < 0.001) and 3.08% (p = 0.013), respectively. Conclusions: The results of this study suggest that the efficacy of digital therapy-based lumbar core exercise for LBP is favorable. However, further large-scale randomized controlled studies are necessary.

Development of a predictive model for hypoxia due to sedatives in gastrointestinal endoscopy: a prospective clinical study in Korea.

Background/Aims: Sedation has become a standard practice for patients undergoing gastrointestinal (GI) endoscopy. However, considering the serious cardiopulmonary adverse events associated with sedatives, it is important to identify patients at high risk. Machine learning can generate reasonable prediction for a wide range of medical conditions. This study aimed to evaluate the risk factors associated with sedation during GI endoscopy and develop a predictive model for hypoxia during endoscopy under sedation. Methods: This prospective observational study enrolled 446 patients who underwent sedative endoscopy at the Korea University Ansan Hospital. Clinical data were used as predictor variables to construct predictive models using the random forest method that is a machine learning algorithm. Results: Seventy-two of the 446 patients (16.1%) experienced life-threatening hypoxia requiring immediate medical intervention. Patients who developed hypoxia had higher body weight, body mass index (BMI), neck circumference, and Mallampati scores. Propofol alone and higher initial and total dose of propofol were significantly associated with hypoxia during sedative endoscopy. Among these variables, high BMI, neck circumference, and Mallampati score were independent risk factors for hypoxia. The area under the receiver operating characteristic curve for the random forest-based predictive model for hypoxia during sedative endoscopy was 0.82 (95% confidence interval, 0.79-0.86) and displayed a moderate discriminatory power. Conclusions: High BMI, neck circumference, and Mallampati score were independently associated with hypoxia during sedative endoscopy. We constructed a model with acceptable performance for predicting hypoxia during sedative endoscopy.

Outcome of Percutaneous Endoscopic Lumbar Discectomy in Relation to the Surgeon's Experience: Propensity Score Matching.

Percutaneous endoscopic lumbar discectomy (PELD) presents a challenging learning curve, and the correlation between surgeon experience and clinical outcomes remains contentious. This retrospective study aimed to compare the outcomes of PELD performed by a single surgeon at beginner and experienced stages. Propensity score matching selected 150 patients (75 per group) with a minimum 3-year follow-up. Clinical and radiological outcomes, perioperative complications, and adverse events were assessed. Baseline characteristics, pain improvement, patient satisfaction, and radiological outcomes did not differ between the groups. However, operation time was longer in the beginner group than in the experienced group (57.5 min [IQR, 50.0-70.0] versus 50.0 min [IQR, 45.0-55.0], p < 0.001). The beginner group had higher perioperative complication rates (eight patients [10.7%] versus one patient [1.3%], with a hazard ratio of 8.836 [95% CI, 1.077-72.514], p = 0.034) and lower 3-year survival without adverse events (19 patients [25.3%] in the beginner group and 10 patients [13.3%] in the experienced group, p = 0.045). Our findings indicate that the clinical outcomes were more favorable in patients operated on at the experienced stage compared to those treated at the beginner stage.