Site-Selective Incorporation of a Functional Group into Lys175 in the Vicinity of the Active Site of Chymotrypsin by Using Peptidyl α-Aminoalkylphosphonate Diphenyl Ester-Derivatives.

We previously reported that Lys175 in the region of the active site of chymotrypsin (Csin) could be site-selectively modified by using an N-hydroxy succinimide (NHS) ester of the peptidyl derivative containing 1-amino-2-ethylphenylphosphonate diphenyl ester [NHS-Suc-Ala-Ala-PheP(OPh)2]. In this study, the Lys175-selective modification method was expanded to incorporate functional groups into Lys 175 in Csin. Two types of peptidyl phosphonate derivatives with the dansyl group (Dan) as a functional molecule, Dan-ß-Ala-[Asp(NHS) or Glu(NHS)]-Ala-Ala-(R)-PheP(OPh)2 (DanD and DanE, respectively), were synthesized, and their action was evaluated when modifying Lys175 in Csin. Ion-exchange chromatography (IEC), fluorescence spectroscopy, and LC-MS/MS were used to analyze the products from the reaction of Csin with DanD or DanE. By IEC and LC-MS/MS, the results showed that DanE reacted with Csin more effectively than DanD to produce the modified Csin (DanMCsin) bearing Dan at Lys175. DanMCsin exhibited an enzymatic activity corresponding to 1/120 of Csin against Suc-Ala-Ala-Phe-pNA. In addition, an effect of Lys175 modification on the access of the proteinaceous Bowman-Birk inhibitor to the active site of DanMCsin was investigated. In conclusion, by using a peptidyl derivative containing 1-amino-2-ethylphenylphosphonate diphenyl ester, we demonstrated that a functional group could be incorporated into Lys175 in Csin.

A Novel Suture Training System for Open Surgery Replicating Procedures Performed by Experts Using Augmented Reality.

The surgical education environment has been changing significantly due to restricted work hours, limited resources, and increasing public concern for safety and quality, leading to the evolution of simulation-based training in surgery. Of the various simulators, low-fidelity simulators are widely used to practice surgical skills such as sutures because they are portable, inexpensive, and easy to use without requiring complicated settings. However, since low-fidelity simulators do not offer any teaching information, trainees do self-practice with them, referring to textbooks or videos, which are insufficient to learn open surgical procedures. This study aimed to develop a new suture training system for open surgery that provides trainees with the three-dimensional information of exemplary procedures performed by experts and allows them to observe and imitate the procedures during self-practice. The proposed system consists of a motion capture system of surgical instruments and a three-dimensional replication system of captured procedures on the surgical field. Motion capture of surgical instruments was achieved inexpensively by using cylindrical augmented reality (AR) markers, and replication of captured procedures was realized by visualizing them three-dimensionally at the same position and orientation as captured, using an AR device. For subcuticular interrupted suture, it was confirmed that the proposed system enabled users to observe experts' procedures from any angle and imitate them by manipulating the actual surgical instruments during self-practice. We expect that this training system will contribute to developing a novel surgical training method that enables trainees to learn surgical skills by themselves in the absence of experts.

A comparison between 2- and 3-dimensional approaches to solid component measurement as radiological criteria for sublobar resection in lung adenocarcinoma ≤ 2 cm in size.

PURPOSE: We compared three-dimensional (3D) and two-dimensional (2D) measurements of the solid component to determine radiological criteria for sublobar resection of lung adenocarcinoma ≤ 2 cm in size. METHODS: We included 233 surgical cases. The maximum size of the solid component for 3D measurement was calculated by delineating the solid component on successive axial images and reconstructing the 3D surface model. RESULTS: The predictive performance for adenocarcinoma in situ (n = 43) and minimally invasive adenocarcinoma (n = 77) were equivalent to areas under the curve of 0.871 and 0.857 for 2D and 3D measurements (p = 0.229), respectively. A solid component of 5 mm had a prognostic impact on both measurements ( ≤ 5 mm versus > 5 mm; p = 0.003 for 2D and p = 0.002 for 3D, log-rank test). Survival rates at 5 years were 94.7-96.9% following lobectomy and sublobar resection among patients with a solid component ≤ 5 mm in size. Sublobar resection resulted in worse survival rates, with declines at 5 years of 15.8% on 2D and 11.5% on 3D measurements, than lobectomy in patients with a solid component > 5 mm in size. CONCLUSIONS: A solid component ≤ 5 mm in size is an appropriate criterion for sublobar resection for both measurements. In addition, 2D measurement is justified because of its simple implementation.

Long-term Culture of Human iPS Cell-derived Telencephalic Neuron Aggregates on Collagen Gel.

It takes several months to form the 3-dimensional morphology of the human embryonic brain. Therefore, establishing a long-term culture method for neuronal tissues derived from human induced pluripotent stem (iPS) cells is very important for studying human brain development. However, it is difficult to keep primary neurons alive for more than 3 weeks in culture. Moreover, long-term adherent culture to maintain the morphology of telencephalic neuron aggregates induced from human iPS cells is also difficult. Although collagen gel has been widely used to support long-term culture of cells, it is not clear whether human iPS cell-derived neuron aggregates can be cultured for long periods on this substrate. In the present study, we differentiated human iPS cells to telencephalic neuron aggregates and examined long-term culture of these aggregates on collagen gel. The results indicated that these aggregates could be cultured for over 3 months by adhering tightly onto collagen gel. Furthermore, telencephalic neuronal precursors within these aggregates matured over time and formed layered structures. Thus, long-term culture of telencephalic neuron aggregates derived from human iPS cells on collagen gel would be useful for studying human cerebral cortex development.Key words: Induced pluripotent stem cell, forebrain neuron, collagen gel, long-term culture.

Identification of Small Peptides in Human Cerebrospinal Fluid upon Amyloid-ß Degradation.

BACKGROUND: Amyloid-ß (Aß) degradation in brains of Alzheimer disease patients is a crucial focus for the clarification of disease pathogenesis. Nevertheless, the mechanisms underlying Aß degradation in the human brain remain unclear. OBJECTIVE: This study aimed to quantify the levels of small C-terminal Aß fragments generated upon Aß degradation in human cerebrospinal fluid (CSF). METHODS: A fraction containing small peptides was isolated and purified from human CSF by high-pressure liquid chromatography. Degradation products of Aß C termini were identified and measured by liquid chromatography-tandem mass spectrometry. The C-terminal fragments of Aß in the conditioned medium of cultured cells transfected with the Swedish variant of ßAPP (sw ßAPP) were analyzed. These fragments in brains of PS1 I213T knock-in transgenic mice, overexpressing sw ßAPP, were also analyzed. RESULTS: The peptide fragments GGVV and GVV, produced by the cleavage of Aß40, were identified in human CSF as well as in the brains of the transgenic mice and in the conditioned medium of the cultured cells. Relative to Aß40 levels, GGVV and GVV levels were 7.6 ± 0.81 and 1.5 ± 0.18%, respectively, in human CSF. Levels of the GGVV fragment did not increase by the introduction of genes encoding neprilysin and insulin-degrading enzyme to the cultured cells. CONCLUSION: Our results indicate that a substantial amount of Aß40 in human brains is degraded via a neprilysin- or insulin-degrading enzyme-independent pathway.

Site-selective chemical modification of chymotrypsin using peptidyl derivatives bearing optically active diphenyl 1-amino-2-phenylethylphosphonate: Stereochemical effect of the diphenyl phosphonate moiety.

Diphenyl (α-aminoalkyl)phosphonates act as mechanism-based inhibitors against serine proteases by forming a covalent bond with the hydroxy group of the active center Ser residue. Because the covalent bond was found to be broken and replaced by 2-pyridinaldoxime methiodide (2PAM), we employed a peptidyl derivative bearing diphenyl 1-amino-2-phenylethylphosphonate moiety (Phe(p) (OPh)2 ) to target the active site of chymotrypsin and to selectively anchor to Lys175 in the vicinity of the active site. Previously, it was reported that the configuration of the α-carbon of phosphorus in diphenyl (α-aminoalkyl)phosphonates affects the inactivation reaction of serine proteases, i.e., the (R)-enantiomeric diphenyl phosphonate is comparable to l-amino acids and it effectively reacts with serine proteases, whereas the (S)-enantiomeric form does not. In this study, we evaluated the stereochemical effect of the phosphonate moiety on the selective chemical modification. Epimeric dipeptidyl derivatives, Ala-(R or S)-Phe(p) (OPh)2 , were prepared by separation with RP-HPLC. A tripeptidyl (R)-epimer (Ala-Ala-(R)-Phe(p) (OPh)2 ) exhibited a more potent inactivation ability against chymotrypsin than the (S)-epimer. The enzyme inactivated by the (R)-epimer was more effectively reactivated with 2PAM than the enzyme inactivated by the (S)-epimer. Finally, N-succinimidyl (NHS) active ester derivatives, NHS-Suc-Ala-Ala- (R or S)-Phe(p) (OPh)2 , were prepared, and we evaluated their action when modifying Lys175 in chymotrypsin. We demonstrated that the epimeric NHS derivative that possessed the diphenyl phosphonate moiety with the (R)-configuration effectively modified Lys175 in chymotrypsin, whereas that with the (S)-configuration did not. These results demonstrate the utility of peptidyl derivatives that bear an optically active diphenyl phosphonate moiety as affinity labeling probes in protein bioconjugation. © 2015 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 106: 521-530, 2016.

How can machine-learning methods assist in virtual screening for hyperuricemia? A healthcare machine-learning approach.

OBJECT: Our purpose was to develop a new machine-learning approach (a virtual health check-up) toward identification of those at high risk of hyperuricemia. Applying the system to general health check-ups is expected to reduce medical costs compared with administering an additional test. METHODS: Data were collected during annual health check-ups performed in Japan between 2011 and 2013 (inclusive). We prepared training and test datasets from the health check-up data to build prediction models; these were composed of 43,524 and 17,789 persons, respectively. Gradient-boosting decision tree (GBDT), random forest (RF), and logistic regression (LR) approaches were trained using the training dataset and were then used to predict hyperuricemia in the test dataset. Undersampling was applied to build the prediction models to deal with the imbalanced class dataset. RESULTS: The results showed that the RF and GBDT approaches afforded the best performances in terms of sensitivity and specificity, respectively. The area under the curve (AUC) values of the models, which reflected the total discriminative ability of the classification, were 0.796 [95% confidence interval (CI): 0.766-0.825] for the GBDT, 0.784 [95% CI: 0.752-0.815] for the RF, and 0.785 [95% CI: 0.752-0.819] for the LR approaches. No significant differences were observed between pairs of each approach. Small changes occurred in the AUCs after applying undersampling to build the models. CONCLUSIONS: We developed a virtual health check-up that predicted the development of hyperuricemia using machine-learning methods. The GBDT, RF, and LR methods had similar predictive capability. Undersampling did not remarkably improve predictive power.

Feasibility of diffusion tensor tractography for preoperative prediction of the location of the facial and vestibulocochlear nerves in relation to vestibular schwannoma.

BACKGROUND: According to recent findings, diffusion tensor tractography (DTT) only allows prediction of facial nerve location in relation to vestibular schwannoma (VS) with high probability. However, previous studies have not mentioned why only the facial nerve was selectively visualized. Our previous report investigated the optimal conditions of DTT for normal facial and vestibulocochlear nerves. In the present study, we applied the optimal conditions of DTT to VS patients to assess the feasibility of DTT for the facial and vestibulocochlear nerves. METHODS: We investigated 11 patients with VS who underwent tumor resection. Visualized tracts were compared with locations of the facial and cochlear nerves as identified by intraoperative electrophysiological monitoring. RESULTS: With the proposed method, visualized tracts corresponded to pathway area of the facial or cochlear nerves in nine of 11 patients (81.8%); specifically, to the pathway area of the facial nerve in three of 11 patients (27.3%), and to the pathway area of the cochlear nerve in six of 11 patients (54.5%). CONCLUSIONS: We visualized facial or vestibulocochlear nerves in nine of 11 patients (81.8%). For the first time, DTT proved able to visualize not only the facial nerve but also the vestibulocochlear nerve in VS patients. Despite our findings, good methods for distinguishing whether a visualized nerve tract represents facial nerve, vestibulocochlear nerve, or only noise remain unavailable. Close attention should therefore be paid to the interpretation of visualized fibers.

Exploring the impact of immersive virtual reality on depression knowledge and stigma reduction: a cross-over RCT fMRI study.

The stigma of mental illness is a form of negative judgmental knowledge and is a barrier to individual seeking treatment. Contact-based educational interventions with first-person perspective (1PP) combined with immersive virtual reality (IVR) is promising as an anti-stigma intervention. This study aims to investigate the effectiveness of 1PP anti-stigma IVR intervention compared to video in enhancing depression knowledge and reducing stigma, as well as to examine the corresponding depression knowledge brain activity change using functional magnetic resonance imaging (fMRI). Participants engaged in a 1PP anti-stigma intervention using both IVR and conventional video, focusing on the daily life and recovery of a patient with mild depression. The change in depression knowledge, stigma-related behavioral, and brain activity using fMRI were measured at pre- and post-interventions. Depression knowledge improved for both interventions; however, only the IVR intervention reduced stigma. In the IVR intervention, depression knowledge score was positively associated with neural response in the right superior frontal gyrus activation, indicative of empathic concern. Conversely, the video intervention correlated with increased activity in the right anterior insula, suggesting a distress-related response. The findings demonstrate that the immersive nature of IVR can reduce stigma more effectively than video intervention. This effectiveness is underpinned by the change in depression knowledge on neural activity, with IVR fostering empathy-related behavioral responses. The results highlight the potential of IVR in enhancing empathic understanding and reducing stigma towards mental illness, emphasizing the need for further exploration into immersive technologies for mental health education.

Visualization of mitochondria in living cells with a genetically encoded yellow fluorescent protein originating from a yellow-emitting luminous bacterium.

We have visualized redox and structural changes in the mitochondria of yeast Saccharomyces cerevisiae as a eukaryotic cell model using a genetically encoded yellow fluorescent protein (Y1-Yellow) and conventional fluorescence microscopy. Y1-Yellow originating from a yellow emitting luminous bacterium Aliivibrio sifiae Y1 was fused with a mitochondria-targeted sequence (mt-sequence). Y1-Yellow fluorescence arising only from the mitochondrial site and the color of yellow fluorescence could be easily differentiated from cellular autofluorescence and from that of conventional probes. Y1-Yellow expressing S. cerevisiae made the yellow fluorescence conspicuous at the mitochondrial site in response to reactive oxygen species (ROS) transiently derived in the wake of pretreatment with hydrogen peroxide. Based on our observation with Y1-Yellow fluorescence, we also showed that mitochondria rearrange to form a cluster structure surrounding chromosomal DNA via respiratory inhibition by cyanide, followed by the generation of ROS. In contrast, uptake of an uncoupler of oxidative phosphorylation is not responsible for mitochondrial rearrangement. These results indicate the utility of Y1-Yellow for visualization of mitochondrial vitality and morphology in living cells.

Presurgical planning of feeder resection with realistic three-dimensional virtual operation field in patient with cerebellopontine angle meningioma.

BACKGROUND: To devascularize meningiomas, the precise location of tumor attachment must be known. However, when a cerebellopontine angle (CPA) meningioma is in contact with many surrounding structures, it can be difficult to distinguish the most vascularized attachment (MVA) from other contact surfaces. OBJECTIVE: To validate the usefulness of a virtual operation field (VOF) of a CPA meningioma by high-spatial-resolution three-dimensional computer graphics (hs-3DCG). METHODS: Presurgical simulation with VOF was performed for eight CPA meningiomas to assess the MVA and the appropriate route to the main feeder. For hs-3DCG, the necessary preoperative radiographic images were fused. A hybrid model of volume and surface rendering was created from the fused images. The simulation results were compared with the operative results, and the MVA estimation rate was compared between VOF and contrast-enhanced fast imaging employing steady-state acquisition. RESULTS: By using VOF, the point at which the main feeder penetrated the tumor was estimated in all cases, and using this information, the MVA was detected. All patients underwent resection of the main feeder in the same way as simulated preoperatively. Estimation rates of MVA were 37.5% in CE-FIESTA and 100% in VOF (p = 0.02, Fisher's exact test). CONCLUSION: The hs-3DCG method was of sufficiently high quality to enable VOF of CPA meningioma. This method may facilitate estimation of MVA and the main feeder penetration point, and may aid in the determination of the most appropriate approach to the main feeder.

Characterization of proteinous coagulant in Moringa tree seeds for water purification: Stepwise laboratory exercise for high-school students.

Coagulation is an important process in the context of water purification; and the seed protein of the moringa tree (Moringa oleifera) is a remarkably effective coagulant. The laboratory course described here is designed to provide high-school students with a stepwise, hands-on experience in investigating the protein-rich coagulant found in Moringa seeds. First, the seed powder was applied to model polluted water containing fine clay, food dyes, copper sulfate, and bacteria. This treatment changed the polluted water into clear water via coagulation; all students were convinced that the coagulation-inducing agent was a thermostable cationic protein. Finally, basic biochemical techniques (e.g., chromatographic separation and electrophoresis) were used to show that the target coagulant is a dimeric protein composed of 6.5 and 4.5 kDa subunits. Overall, this made it possible for the students to gain a deeper understanding (more comprehensive than the information taught in formal classes) of protein structure and its real-world implications. This stepwise exercise can be applied to research-based learning programs in high school, as it is an effective learning tool.

Public Stigma Related to People With Mental Health Conditions Among Japanese Company Employees.

Background: The public stigma related to mental illness is the general public's negative misconceptions about people with mental health conditions (PMHCs). The public stigma of mental illness is detrimental to PMHC as it leads to loss of opportunities and unemployment. The aim of the study was to clarify the status of public stigma related to PMHC, focusing on knowledge about mental illness and social distance concerning PMHC. Methods: A survey was conducted among 970 Japanese office workers aged 20 to 60 years. Accurate knowledge of mental illness was assessed using the Mental Illness and Disorder Understanding Scale (MIDUS). The Attitudinal Social Distance (ASD) was used to determine social distance in relation to PMHC. The demographic characteristics of the participants evaluated were sex, age group measured in years, employment position, employment status, and attendance at mental illness stigma training. Results: Regular employees (P = 0.03) and those having prior contact experience (P = 0.01) had more accurate knowledge. Participants between 50 to 59 years old (M = 15.87, standard deviation (SD) = 3.35) had greater social distance than those under 30 years old (M = 14.78, SD = 3.97, P < 0.05). The results of multiple linear regression analysis found that employment status (partial r = -0.07, P < 0.05) and prior contact experience (partial r = -0.15, P < 0.01) significantly affected the MIDUS score, whereas no variable had a significant effect on the ASD score. Conclusions: Accurate knowledge of mental illness was significantly higher among regular employees and those with contact experience. Social distance was significantly lower among those under the age of 30 years.

Analysis of functional ingredients of tempe-like fermented Moringa oleifera seeds (Moringa tempe) prepared with Rhizopus species.

Tempe is a fermented food prepared by fermenting soybeans with Rhizopus species. However, there have recently been concerns about the stable supply of raw soybeans due to global warming and other factors. Moringa is a plant whose cultivation area is expected to expand in the future, and its seeds contain abundant proteins and lipids, and thus could be used as an alternative to soybeans. To develop a novel functional Moringa food, we fermented dehulled Moringa seeds with Rhizopus oligosporus and Rhizopus stolonifer using the solid fermentation method of tempe and investigated changes in the functional components, such as free amino acids and polyphenols, of the respective obtained Moringa tempe Rm and Rs. After 45 h of fermentation, the total content of free amino acids, mainly including gamma-aminobutyric acid and l-glutamic acid, in Moringa tempe Rm was about three times higher, while that in Moringa tempe Rs was almost the same, compared to that in unfermented Moringa seeds. Moreover, after 70 h of fermentation, both Moringa tempe Rm and Rs had approximately four times higher polyphenol content and significantly higher antioxidant activity than did unfermented Moringa seeds. Further, the content of each residual chitin-binding protein of defatted Moringa tempe Rm and Rs was almost the same as that of unfermented Moringa seeds. Taken together, Moringa tempe was rich in free amino acids and polyphenols, exhibited better antioxidant activity, and retained the levels of its chitin-binding proteins, suggesting that Moringa seeds could be used as an alternative to soybean for tempe preparation.

De-Identification Technique with Facial Deformation in Head CT Images.

Head CT, which includes the facial region, can visualize faces using 3D reconstruction, raising concern that individuals may be identified. We developed a new de-identification technique that distorts the faces of head CT images. Head CT images that were distorted were labeled as "original images" and the others as "reference images." Reconstructed face models of both were created, with 400 control points on the facial surfaces. All voxel positions in the original image were moved and deformed according to the deformation vectors required to move to corresponding control points on the reference image. Three face detection and identification programs were used to determine face detection rates and match confidence scores. Intracranial volume equivalence tests were performed before and after deformation, and correlation coefficients between intracranial pixel value histograms were calculated. Output accuracy of the deep learning model for intracranial segmentation was determined using Dice Similarity Coefficient before and after deformation. The face detection rate was 100%, and match confidence scores were < 90. Equivalence testing of the intracranial volume revealed statistical equivalence before and after deformation. The median correlation coefficient between intracranial pixel value histograms before and after deformation was 0.9965, indicating high similarity. Dice Similarity Coefficient values of original and deformed images were statistically equivalent. We developed a technique to de-identify head CT images while maintaining the accuracy of deep-learning models. The technique involves deforming images to prevent face identification, with minimal changes to the original information.

Reproducibility of Facial Information in Three-Dimensional Reconstructed Head Images: An Exploratory Study.

BACKGROUND: Facial information acquired via three-dimensional reconstruction of head computed tomography (CT) data may be considered personal information, which can be problematic for neuroimaging studies. However, no study has verified the relationship between slice thickness and face reproducibility. This study determined the relationship and match rate between image slice thickness and face detection accuracy of face-recognition software in facial reconstructed models. METHODS: Head CT data of 60 cases comprising entire faces obtained under conditions of non-contrast and 1-mm slice thickness were resampled to obtain 2-10-mm slice-thickness data. Facial models, reconstructed by image thresholding, were acquired from the data. We performed face detection tests per slice thickness on the models and calculated the face detection rate. The reconstructed facial models created from 1-mm slice-thickness data and other slice thicknesses were used as training and test data, respectively. Match confidence scores were obtained via three programs, match rates were calculated per slice thickness, and generalized estimating equations were used to evaluate the match rate trend. RESULTS: In general, the face detection rates for the 1-10-mm slice thicknesses were 100, 100, 98.3, 98.3, 95.0, 91.7, 86.7, 78.3, 68.3, and 61.7 %, respectively. The match rates for the 2-10-mm slice thicknesses were 100, 98.3, 98.3, 95.0, 85.0, 71.7, 53.3, 28.3, and 16.7 %, respectively. CONCLUSION: The reconstructed models tended to have higher match rates as the slice thickness decreased. Thus, thin-slice head CT imaging data may increase the possibility of the information becoming personally identifiable health information.

Assessment of substrate inhibition of bacterial oligopeptidase B.

Oligopeptidase B (OPB; EC 3.4.21.83) from 2 Gram-negative bacteria, Stenotrophomonas maltophilia (Stm) and Serratia marcescens (Sem), and the Gram-positive bacterium Rhodococcus erythropolis (Re) were cloned and characterized to clarify their activities and substrate specificities using peptidyl-MCA substrates containing Arg or Lys. The cloned enzymes, Stm, Sem and ReOPBs, in addition to Escherichia coli OPB (EcOPB) were expressed using a pET expression system. Although the Stm and SemOPBs share 45% sequence identity to each other and up to 60% identity with respect to their catalytic domains, their activities towards MCA substrates were quite different. StmOPB is approximately 100-500 times more active than SemOPB and 3-30 times more active than EcOPB. The activity of ReOPB is comparable to that of StmOPB and it shares 40% and 36% identity to StmOPB and SemOPB, respectively. Some features of Stm, Re and EcOPBs are similar to those of previously cloned OPBs, which were also strongly inhibited by substrates, but SemOPB differs from all other OPBs in that it is not inhibited by substrates; even substrates containing double arginine at 35 µM did not inhibit SemOPB. On the other hand, the same substrates at only 5 µM inhibited the activity of the Stm, Re, and EcOPB. This phenomenon was not observed with substrates containing single or double lysine.

A high-resolution method with increased matrix size can characterize small arteries around a giant aneurysm in three dimensions.

Visualization of the small arteries around a giant intracranial aneurysm remains challenging, even with three-dimensional (3D) rotational angiography. Here we present a new method with the increased matrix size to visualize three-dimensional course of the anterior choroidal artery around a giant aneurysm to help estimate the risk of intraoperative complications.

Augmented reality self-training system for suturing in open surgery: A randomized controlled trial.

BACKGROUND: Existing self-training materials are insufficient to learn open surgical procedures, and a new self-training system that provides three-dimensional procedural information is needed. The effectiveness and usability of a self-training system providing three-dimensional information by augmented reality (AR) were compared to those of an existing self-training system, instructional video, in self-learning of suturing in open surgery. MATERIALS AND METHODS: This was a prospective, evaluator-blinded, randomized, controlled study. Medical students who were suturing novices were randomized into 2 groups: practice with the AR training system (AR group) or an instructional video (video group). Participants were instructed in subcuticular interrupted suture and each training system and watched the instructional video once. They then completed a pretest performing the suture on a skin pad. Participants in each group practiced the procedure 10 times using each training system, followed by a posttest. The pretest and posttest were video-recorded and graded by blinded evaluators using a validated scoring form composed of global rating (GR) and task-specific (TS) subscales. Students completed a post-study questionnaire assessing system usability, each system's usefulness, and their confidence and interest in surgery. RESULTS: Nineteen participants in each group completed the trial. No significant difference was found between the AR and video groups on the improvement of the scores from pretest to posttest (GR: p = 0.54, TS: p = 0.91). The posttest scores of both GR and TS improved significantly from pretest in both groups (GR: both p < 0.001, TS: both p < 0.001). There was no significant difference between the groups in the system usability scale scores (p = 0.38). The motion provided in the AR system was more helpful for manipulating surgical instruments than the video (p = 0.02). CONCLUSION: The AR system was considered as understandable and easy to use as the instructional video in learning suture technique in open surgery for novices.