Complete atrioventricular block following internal electrical cardioversion during atrial fibrillation ablation.

BACKGROUND: Complete atrioventricular block (C-AVB) following internal electrical cardioversion (IEC) during atrial fibrillation (AF) ablation has not been fully investigated. We aimed to determine the prevalence and predictors of C-AVB following IEC during AF ablation. METHODS: C-AVB (non-conducted sinus impulse after IEC) and ventricular pause (VP) (the interval between IEC and the QRS complex) following the first attempt of IEC, and baseline electrocardiographic parameters were investigated in patients who underwent first-time AF ablation. RESULTS: We investigated the first attempt of IEC in 124 patients (mean age:70 ± 11 years, 81 men, 99 non-paroxysmal AF). AF was terminated in 109/124 (88%) patients, with a VP of 1590 [1014-2208] (maximum, 8780) ms. Transient C-AVB following IEC occurred in 14/109 (13%) patients. The VP was longer in patients with transient C-AVB than in those without transient C-AVB (2418 [1693-4425] vs. 1530 [876-2083] ms, p = 0.002). In multivariate analysis, the left atrial diameter (Odds ratio [OR]:1.21; 95% confidence interval (95%CI):1.06-1.39; p = 0.005) and preexisting intraventricular conduction abnormality (OR:9.22; 95%CI:1.60-53.3; p = 0.013) were predictors of transient C-AVB following IEC. CONCLUSION: Left atrial diameter and preexisting intraventricular conduction abnormalities were predictors of transient C-AVB following IEC during AF ablation.

Disinfection and Isotonic Drinks' Influence on Hardness and Color Stability of Ethylene-Vinyl-Acetate Copolymer Mouthguards Used in Martial Arts: An In Vitro Study.

This in vitro study aimed to evaluate the hardness and color change of an ethylene-vinyl-acetate copolymer (EVA) material for mouthguards after exposition to different cleaning agent solutions and isotonic drinks. Four hundred samples were prepared and divided into four equinumerous groups (n = 100), in which there were 25 samples from each color of EVA (red, green, blue and white). The hardness, using the digital durometer, and the color coordinates (CIE L*a*b*), using the digital colorimeter, were measured before the first exposition and after 3 months of exposition to spray disinfection and incubation in the oral cavity temperature, or immersion in isotonic drinks. The values of Shore A hardness (HA) and color change (ΔE-calculated by Euclidean distance) were statistically analyzed using the Kolmogorov-Smirnov test, multiple comparison ANOVA/Kruskal-Wallis and appropriate post-hoc tests. Statistically significant changes in color and hardness between the tested groups were demonstrated after the use of agents predestined for disinfecting the surface of mouthguards on the tested samples. There were no statistically significant differences in color and hardness between the groups immersed in isotonic sport drinks potentially consumed by competitors practicing combat sports using mouthguards. Despite the changes in color and hardness after the use of disinfectants, the deviations were minor and limited to specific colors of the EVA plates. The intake of isotonic drinks practically did not change either the color or the hardness of the samples, regardless of the tested color of the EVA plates.

A 20-year clinical survey of radiotherapy prostheses at the Clinic for Maxillofacial Prosthetics of Tokyo Medical and Dental University Hospital.

PURPOSE: To identify secular trends in the use of radiotherapy prostheses in the Clinic for Maxillofacial Prosthetics at Tokyo Medical and Dental University Hospital and to ascertain patient characteristics and future needs. METHODS: The study included all patients who visited the clinic between January 1, 2000, and December 31, 2019. Data on numbers of cases, gender and age, numbers and types of radiotherapy prostheses, primary cancer site, and time required for prosthesis fabrication during the study period were collected from medical records and retrospectively analyzed. RESULTS: During the 20-year study period, 1,066 prostheses were fabricated for 1,135 cases. In most years, at least 60% of cases were male. The mean age increased from 60.6 to 67.1 years during the study period, and the number of cases older than 70 years increased over time. The most common cancer site was the tongue, and the most common type of radiotherapy prosthesis was a spacer. The mean time for spacer fabrication was 11 days. CONCLUSION: During a recent 20-year period, mean age and the proportion of elderly patients requiring savers increased. When treating elderly patients, prosthodontists responsible for fabricating radiotherapy prostheses must collaborate effectively with radiation oncologists.

Revisiting exit block after entrance block: Investigation of ablation index-guided pulmonary vein isolation.

INTRODUCTION: Unidirectional block, left atrium to pulmonary vein (LA-PV) entrance block without PV-LA exit block, has not been fully investigated in the setting of ablation index (AI)-guided pulmonary vein (PV) isolation (PVI). The aim of this study was to investigate unidirectional blocks during AI-guided PVI. METHODS: After achieving entrance block, exit block was evaluated by pacing from the catheter placed in the PV. Local PV musculature capture without conduction to the LA was necessary to prove exit block. RESULTS: In total, 441 PVs (including nine left common PVs) from 113 consecutive patients (mean age: 71 ± 12 years, 77 men, 61 paroxysmal atrial fibrillation cases) who underwent initial AI-guided PVI for atrial fibrillation were studied. Entrance block was achieved in all PVs. of the 247/441 (56%) PVs showing local PV musculature capture, 5/247 (2.0%) showed unidirectional blocks. Three of the five PVs (left superior and inferior PVs in one patient; right superior PV in another patient) showed LA-PV reconnection, requiring additional ablation to achieve bidirectional block during the procedure. Two of the five PVs (left superior and inferior PVs in one patient) showed LA-PV reconnection, and thereafter, LA-PV conduction became blocked again spontaneously, leading to bidirectional block without further ablation during the procedure. CONCLUSION: AI-guided PVI presented a low prevalence of unidirectional block (2%), using entrance block alone as the endpoint of PVI could therefore be justified.

Quantitative text analysis of the mechanisms of tooth injury: Analysis of accidents in five sports that occurred in 15 years under school control.

BACKGROUND/AIM: Dental trauma may occur in school settings and it can impact patients' quality of life. Analysis of the occurrences of dental trauma is essential in identifying preventive methods. There are numerous reports of such accidents but most are quantitative analyses with limited data. The aim of this study was to extract information on the mechanisms of injuries that leads to prevention by performing a qualitative analysis of the occurrence of dental trauma. MATERIAL AND METHODS: After screening 7684 cases of dental injuries that occured in schools and were reported to the Japan Sports Council between 2005 and 2020, 533 detailed descriptions of injuries that occurred during sports were included. Quantitative text analysis was performed on the target data by performing statistical analysis, extracting frequently used words, and creating a co-occurrence network. Injury mechanisms were evaluated based on appearance of words. RESULTS: Dental injuries occurred frequently in five sports included in the survey. They were in order of decreasing frequency: baseball, basketball, soccer, volleyball, and rugby. Males were injured more often in all sports other than volleyball. The number of accidents increased in all sports among high school students. The frequent word list and co-occurrence network were different for each sport. This allowed typical accident occurrence mechanisms to be extracted for these five sports. CONCLUSIONS: Typical accident occurrence mechanisms were extracted from quantitative text analysis targeting free texts on the occurrence of accidents for five sports. Quantitative text analysis is useful for the evaluation of accident cases, which may aid in accident prevention.

Atrial activation sequence changes during ventricular overdrive pacing: What is the mechanism?

We describe atrial activation sequence changes during ventricular overdrive pacing in a patient with a concealed left-sided accessory pathway and discuss its potential mechanism.

Continuous Oral Administration of Sonicated P. gingivalis Delays Rat Skeletal Muscle Healing Post-Treadmill Training.

BACKGROUND: A delay in muscle repair interferes with the effect of training or exercise; therefore, it is important to identify the factors that delay muscle repair. P. gingivalis, one of the most common periodontal disease pathogens, has the potential to inhibit muscle repair after training, as inferred from a previous study. To assess the expression of satellite cells in this in vivo study, we evaluated the relationship between P. gingivalis and muscle regeneration after training. METHODS: A total of 20 male Wistar rats (eight weeks in age) were randomly divided into two groups: one orally administered sonicated P. gingivalis four times per week for six weeks (PG group) and one given no treatment (NT group). After four weeks of training using a treadmill, the gastrocnemius was evaluated using histology of the cross-sectional area (CSA) of myotubes and immunohistochemistry of the expression of skeletal muscle satellite cells. In addition, an endurance test was performed a day before euthanization. RESULTS: The CSA and expression of Pax7+/MyoD- and Pax7+/MyoD+ cells were not significantly different between the groups. However, the expression of Pax7-/MyoD+ cells and running time until exhaustion were significantly lower in the PG group. CONCLUSIONS: Infection with P. gingivalis likely interferes with muscle repair after training.

Two-piece detachable interlocking mold for low-dose-rate brachytherapy: A dental technique for radiotherapy prosthesis fabrication.

Brachytherapy is a type of radiotherapy used to eradicate malignancies in the head-and-neck region. Early-stage mucosal carcinomas, such as carcinomas of the hard palate and gingival mucosa, can be treated with low-dose-rate brachytherapy by using a radiotherapy prosthesis called a mold. Prosthodontists play a significant role in the design and fabrication of these molds, which deliver therapeutic doses to the primary lesion and protect adjacent tissues from radiation exposure. However, planning and observing ongoing treatment is difficult for radiation oncologists because the shield part cannot be removed from the carrier part or requires an attachment to do so. This article describes a technique for fabricating a 2-piece detachable interlocking mold without any special attachment for low-dose-rate brachytherapy.

Solubility affects IL-1ß-producing activity of the synthetic candidalysin peptide.

Candidalysin, a peptide toxin produced specifically from hyphae of Candida albicans, plays a crucial role in C. albicans pathogenesis in the oral cavity and vagina. Synthetic peptides have been widely used in previous studies to investigate the bioactivity of candidalysin. Although the solubility of the peptide, which is expected to have a hydrophobic property, has not been well characterized, candidalysin solutions are usually prepared in water. In this study, we prepared the synthetic peptide candidalysin in water (CLw) or in dimethyl sulfoxide (CLd) and compared their cytotoxicity and interleukin (IL)-1ß-producing activity to determine whether the activity of the peptide would be affected. In addition, we evaluated whether the NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome pathway or other pathways were involved in their activities. Unexpectedly, we found that CLw was not completely solubilized and contained abundant insoluble microparticles. CLw was active at comparably high concentrations (≥ 10 µM). In contrast, CLd is completely solubilized and sufficiently active at low concentrations, that is, 1 µM or less. CLw showed weak cytotoxicity and NLRP3-dependent and cathepsin B-dependent IL-1ß-producing activity, whereas CLd showed strong cytotoxicity and cathepsin B-dependent IL-1ß-producing activity. Fractionation of CLw revealed that NLRP3-dependent activity was caused by insoluble microparticles. Furthermore, nanoparticle tracking of CLd revealed that the peptide was present as nanoparticles with a size of 96 nm. CLw contained a small amount of such nanoparticles. Thus, the bioactivities of the synthetic peptide candidalysin, especially the IL-1ß-producing activity, are affected by the solubility of the peptide depending on the solvent employed. The NLRP3-dependent activity of the synthetic peptide is caused by insoluble microparticles and may not be the intrinsic activity of candidalysin.

True Brugada syndrome ECG or Brugada phenocopy ECG? Can the ECG itself tell us the diagnosis?

We described a type 1 Brugada electrocardiogram and discussed about the potential diagnostic electrocardiographic indicators to differentiate true Brugada syndrome and Brugada phenocopy.

Case Report: Psychoacoustic Analysis of a Clarinet Performance With a Custom-Made Soft Lip Shield Worn to Prevent Mucosal Erosion of Lower Lip.

Introduction: Wind instrument players sometimes suffer from erosion of the mucous membrane of the lip. This is caused by the action and pressure of the mouthpiece of the wind instrument against teeth. To address this problem, a lip shield is fitted over the dental arch to prevent direct contact between the lips and teeth. However, there are a few studies on the influence of the lip shield on the acoustics of wind instruments. The purpose of this study was to analyze the psychoacoustics of a clarinet performance with the player wearing a custom-made soft lip shield to prevent mucosal erosion of the lower lip. Case Description: A lip shield was custom-made with a soft thermoplastic material for a female clarinetist who complained of mucosal erosion and pain of the lower lip. The psychoacoustics of her musical performance played in different dynamics, fortissimo, mezzo forte and pianissimo were analyzed, including loudness and sharpness. A self-evaluation questionnaire with items rated on a 10-point scale was administered. After wearing the lip shield, the patient reported that the mucosal erosion and pain of her lower lip when playing clarinet resolved. The lip shield had little effect on the loudness. There was a slight decrease in sharpness when the lip shield was worn compared to when it was not, describing the reduction of high frequencies. Furthermore, fewer variations in sharpness between the tones were observed. Conclusion: The results suggest that lip shields made of soft materials can eliminate mucosal erosion and pain of the lower lip while having little effect on performance, although, a slight change in timbre is possible.

Electrocardiographic features of paradoxical ventriculophasic response.

BACKGROUND: Paradoxical ventriculophasic response (P-VR), a rare entity, has not been fully investigated. This study sought to compare the electrocardiographic features of P-VR and typical ventriculophasic response (T-VR). METHODS: The 12­lead electrocardiogram (ECG) data recorded before implantation of a cardiac implantable electronic device were analyzed in patients with greater than second-degree atrioventricular block (AVB). P-VR or T-VR was defined as present if the PP interval interposing a QRS complex was prolonged or shortened, respectively, by >3% compared with the preceding PP interval without a QRS complex when a QRS complex occurred within a span of 60% of the preceding PP interval. RESULTS: Of 95 patients (age 80 ± 9 years; 49 men) with heart block, 1868 instances (an instance was defined as a set of PP intervals without a QRS complex and the subsequent PP interval interposing a QRS complex) from 214 ECGs were analyzed: 894 instances from 122 ECGs in 64 patients with complete AVB (cAVB) and 974 instances from 92 ECGs in 43 patients with 2:1 AVB (12 showed both cAVB and 2:1 AVB). P-VR was observed in 48 patients (51%). The position of the interposed QRS complex relative to the preceding PP interval was earlier in P-VR than in T-VR. The PP interval was shorter in P-VR than in T-VR. CONCLUSION: P-VR was present in >50% of patients and was affected by the position of the interposed QRS complex and the PP interval.

Useful design of custom-made mouthguard for athletes undergoing orthodontic treatment with brackets and wires.

BACKGROUND/PURPOSE: Custom-made mouthguards (MGs) are strongly recommended for athletes during sports activities to prevent dental injuries. Athletes undergoing orthodontic treatment and wearing brackets require specially designed MGs for better protection and to create more space that will not hinder the planned orthodontic tooth movement. The purpose of this study was to fabricate effective, specially designed, custom-made MGs for patients or athletes with ongoing orthodontic treatment and to evaluate the shock absorption abilities of these MGs by an in vitro comparison of three different designs. MATERIALS AND METHODS: Three different types of specially designed, double-layered MGs, (i) creating inter bracket space inside the MG, (ii) embedding silicon wax inside the MG, and (iii) creating a buffer space with additional hard insertion, were fabricated from a simulated bracket attached model. Impact test was performed using a free-falling object on a vertical rod, and the strain-gauge system was used to assess the strain on the dentition with the MGs for the comparison of the shock absorption abilities of the three types. Analysis of variance at a significance level of 5% and multiple comparisons were performed for statistical analysis. RESULTS: The strains on the dentition with the MG creating buffer space with hard insertion were significantly lower than those with the other two types of MG (P < 0.001). CONCLUSION: Insertion of a hard material and ensuring buffer space between the MG and the teeth and/or appliance was more effective than other methods of fabricating custom-made MGs to prevent sports-related traumatic dental injuries in athletes undergoing orthodontic treatment.

Regularly irregular atrial rhythm after superior vena cava isolation: Another manifestation of sinoatrial node injury?

The present case described an unusual clinical manifestation of the sinoatrial node (or sinoatrial junction) injury during superior vena cava isolation.

Validation of the correlation between angiosome-based target arterial path, mid-term limb-based patency, and the global limb anatomical staging system.

This study aimed to validate the correlation between the Global Limb Anatomical Staging System (GLASS) and limb-based patency (LBP) and angiosome-based target arterial path (TAP) and to detect the predictors of LBP loss. After the publication of the Global Vascular Guidelines in 2019, the evaluation of GLASS and identification of TAP have been recommended. However, there are few reports regarding GLASS. Eighty-three patients with chronic limb-threatening ischemia (CLTI) and tissue loss from 2016 to 2020 were evaluated. The correlation between GLASS and LBP and successful revascularization of angiosome-based TAP was analyzed. We also investigated the predictors of LBP loss. The number of patients in each GLASS stage was as follows: GLASS I, 6 patients; GLASS II, 15 patients; GLASS III, 62 patients. At 6 months, the Kaplan-Meier estimate of LBP was 66.7% in GLASS I, 41.6% in GLASS II, and 16.4% in GLASS III, respectively (p = 0.034). The rate of successful revascularization of angiosome-based TAP was 100% in GLASS I, 86.7% in GLASS II, and 46.8% in GLASS III, respectively (p = 0.002). Multivariate analysis showed that the Wound, Ischemia, and foot Infection (WIfI) stage [hazard ratio (HR) 1.58; 95% confidence interval (CI) 1.07-2.33; p = 0.021] and GLASS infrapopliteal (IP) grade (HR 1.96; 95% CI 1.31-2.95; p = 0.001) were the independent predictors of LBP loss. The GLASS stage was significantly correlated with successful revascularization of angiosome-based TAP and mid-term LBP. The WIfI stage and GLASS IP grade were the independent predictors of loss of LBP.

Antibacterial effect of a disinfectant spray for sports mouthguards on Streptococcus sobrinus.

BACKGROUND: Mouthguard (MG) disinfectant sprays are available for maintaining MG hygiene. The effect of these sprays against Streptococcus sobrinus is still unknown. The purpose of this study was to evaluate the antibacterial effect of an MG disinfectant spray against S. sobrinus using the modified ISO 22196 standard. MATERIALS AND METHODS: In this in vitro study, we used the following treatment groups for antibacterial testing: MG spray-1 (left in spray for 30 s), MG spray-2 (60 s), and control (n = 4). All analyses were performed at a statistically significant level (P = 0.05) using JMP® 14. RESULTS: The log colony-forming units of the MG spray-2 group were significantly lower than those of the other groups. The antibacterial activity of MG spray-2 against S. sobrinus was >2.1. CONCLUSION: We confirmed the antibacterial effect of the MG spray against S. sobrinus, and it was influenced by the treatment duration, with the optimum effect at a longer duration.

Air Permeability, Shock Absorption Ability, and Flexural Strength of 3D-Printed Perforated ABS Polymer Sheets with 3D-Knitted Fabric Cushioning for Sports Face Guard Applications.

Sports face guards (FGs) are devices that protect athletes from maxillofacial injury or ensure rapid return to play following orofacial damage. Conventional FGs are uncomfortable to wear owing to stuffiness caused by poor ventilation and often slip off due to increase in weight due to absorption of moisture from perspiration, lowering players' performance. Herein, combinations of 3D-printed perforated acrylonitrile butadiene styrene (ABS) polymer sheets and 3D-knitted fabrics with honeycomb structures as cushioning materials were investigated to balance better wearing feel and mechanical properties. The flexural strength, weight, and shock absorption ability of, and air flow rate through, the ABS sheets with five different perforation patterns were evaluated and compared with those of conventional FG materials comprising a combination of polycaprolactone sheets for the medical splint and polychloroprene rubber for the cushioning material. The ABS sheets having 10% open area and 2.52 mm round holes, combined with knitted fabric cushioning, exhibited the requisite shock absorbing, higher air permeability, and lower weight properties than the conventional materials. Our results suggest that FGs fabricated using combinations of 3D-printed perforated ABS polymer sheets and 3D-knitted fabrics with honeycomb structures may impart enhanced wearing comfort for athletes.