Continuous specimen cooling during slicing and thickness measurement contributes to improved accuracy in image analysis of pathologic specimens.

We measured section thickness (ST) after slicing using a film thickness meter and investigated the relationship between ST and the percent area of positive staining using computer-assisted image analysis. METHODS: Sections were prepared from a paraffin-only block and formalin-fixed paraffin-embedded (FFPE) blocks containing fish sausage and human liver specimens. The ST was compared between the sections prepared with cooling using an ice pack (IP) or a continuous cooling device (CCD) paired with a sliding microtome set at an ST of 4 µm. The sections were stained with eosin or aniline blue, and the association between the percent area of positive staining and ST was determined using computer-aided analysis of images captured with a whole slide scanner. RESULTS: The average STs of the paraffin-only block sections measured by four practitioners were 5.01-5.41 and 4.09-4.33 µm in samples prepared using an IP and a CCD, respectively. Therefore, subsequent analyses included sections prepared using the CCD. The ST of the tissue surface was significantly thinner than that of the paraffin surrounding the tissue section. Furthermore, the percent areas of positive staining for eosin and aniline blue were significantly correlated with ST in both the fish sausage and liver sections. The analysis of the ST and percent area of positive staining in 60 sections of the same block, which were categorized into quantiles based on ST, revealed a significant difference in the percent area of positive staining between the thicker and thinner sections. DISCUSSION: Specimen sectioning should be performed with a CCD, ST should be measured before the staining of pathologic specimens prepared for quantitative analysis, and histologic examination should be performed using specimens with uniform ST.

Microwave-assisted C-C bond formation of diarylacetylenes and aromatic hydrocarbons on carbon beads under continuous-flow conditions.

The synthesis of polycyclic aromatic compounds generally requires stoichiometric oxidants or homogeneous metal catalysts, however, the risk of contamination of inorganic residues can affect their properties. Here we present a microwave (MW)-assisted platinum on beaded activated carbon (Pt/CB)-catalyzed C-C bond formation of diarylacetylenes and aromatic hydrocarbons under continuous-flow conditions. Various fused aromatic compounds were continuously synthesized via dehydrogenative C(sp2)-C(sp2) and C(sp2)-C(sp3) bond formation with yields of up to 87% without the use of oxidants and bases. An activated, local reaction site on Pt/CB in the flow reaction channel reaching temperatures of more than three hundred degrees Celsius was generated in the catalyst cartridge by selective microwave absorption in CB with an absorption efficiency of > 90%. Mechanistic experiments of the transformation reaction indicated that a constant hydrogen gas supply was essential for activating Pt. This is an ideal reaction with minimal input energy and no waste production.

Diagnostic accuracy of ambulatory polysomnography with electroencephalogram for detection of sleep bruxism-related masticatory muscle activity.

STUDY OBJECTIVES: This study investigated the diagnostic accuracy of Sleep Profiler, which relies on ambulatory polysomnography (PSG) with electroencephalogram for sleep bruxism (SB) and examined its episode-by-episode agreement in comparison to PSG equipped with audiovisual recordings (avPSG). METHODS: This prospective 2-gate study recruited 10 individuals with probable SB and 10 healthy volunteers. Overnight experimental recordings were performed simultaneously using the ambulatory PSG with masseter electromyography and avPSG with masseter and temporalis electromyography. Sleep staging was performed manually for avPSG and automatically or manually for ambulatory PSG. SB episodes were manually scored based on electromyography signals with reference to sleep stages. The episode-by-episode agreement was analyzed by setting avPSG as the reference standard. The sensitivity, specificity, and accuracy for the diagnosis of SB were calculated after optimizing the cutoff values of the episode index and the burst index. RESULTS: Regarding the episode-by-episode agreement, median sensitivities were 0.825 and positive predictive values were approximately 0.6, regardless of the sleep staging procedure, indicating that approximately 40% of the overall total SB episodes scored by the ambulatory PSG were false positives. Because of overestimation of SB episodes, the optimal cutoff values for the episode index and the burst index were approximately 1.5 times higher than the avPSG-based cutoff values and dramatically improved the diagnostic precision metrics for the ambulatory PSG. CONCLUSIONS: Sleep Profiler can eliminate events during wakefulness by electroencephalogram and may provide a definitive diagnosis in patients with possible SB by applying optimized cutoff values. However, the risk of overestimation must be recognized. CLINICAL TRIAL REGISTRATION: Registry: UMIN Clinical Trials Registry; Name: Accuracy of Portable PSG Device for Detection of Sleep Bruxism-Related Masseter EMG Muscle Activity; URL: https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000037380; Identifier: UMIN000032793. CITATION: Abe Y, Nakazato Y, Takaba M, Kawana F, Baba K, Kato T. Diagnostic accuracy of ambulatory polysomnography with electroencephalogram for detection of sleep bruxism-related masticatory muscle activity. J Clin Sleep Med. 2023;19(2):379-392.

Oral function of implant-assisted removable partial dentures with magnetic attachments using short implants: A prospective study.

OBJECTIVES: This prospective study aimed to compare the oral functions of removable partial dentures (RPDs) with those of implant-assisted removable partial dentures (IARPDs) with short implants and magnetic attachments in patients with mandibular Kennedy class I and II. MATERIAL AND METHODS: Thirty participants with mandibular Kennedy class I or II and at least three distal missing teeth were recruited. Oral functions, including mixing ability, comminuting ability, maximum bite force, and occlusal contact area, were assessed for RPDs (stage 0), IARPDs with healing caps (stage 1), and IARPDs with magnetic attachments (stage 2). The implants were loaded with occlusal force in stages 1 and 2. Finally, the data of the 27 participants who completed the evaluation at stage 2 were analyzed. The Wilcoxon signed-rank test with Bonferroni correction was used to assess the differences in the oral functions among the different stages. RESULTS: The implant survival rate was 93.8%. There were significant differences in the comminuting ability and occlusal contact area between stages 0 and 2 (p < .001 and p = .036, respectively) and stages 1 and 2 (p = .003 and p = .015, respectively). Regarding the maximum bite force, there was a significant difference between stages 1 and 2 (p = .018). However, there was no significant difference in the mixing ability between the three stages. CONCLUSIONS: Within the limitations of this study, it was concluded that IARPDs in the mandible with short implants and magnetic attachments may improve oral functions.

Managements of sleep bruxism in adult: A systematic review.

This systematic review aimed to update the management of sleep bruxism (SB) in adults, as diagnosed using polysomnography (PSG) and/or electromyography (EMG). Management methods covered were oral appliance therapy (OAT) with stabilization splints, cognitive-behavioral therapy (CBT), biofeedback therapy (BFT), and pharmacological therapy. A comprehensive search was conducted on MEDLINE, Cochrane Library, and Web of Science up to October 1st, 2021. Reference list searches and hand searches were also performed by an external organization. Two reviewers for each therapy independently performed article selection, data extraction, and risk of bias assessment. The reviewers resolved any disagreements concerning the assortment of the articles by discussion. Finally, 11, 3, 14, and 22 articles were selected for each therapy. The results suggested that OAT tended to reduce the number of SB events, although there was no significant difference compared to other types of splints, that the potential benefits of CBT were not well supported, and that BFT, rabeprazole, clonazepam, clonidine, and botulinum toxin type A injection showed significant reductions in specific SB parameters, although several side effects were reported. It can be concluded that more methodologically rigorous randomized large-sample long-term follow-up clinical trials are needed to clarify the efficacy and safety of management for SB.

Increased excitability of human iPSC-derived neurons in HTR2A variant-related sleep bruxism.

Sleep bruxism (SB) is a sleep-related movement disorder characterized by grinding and clenching of the teeth during sleep. We previously found a significant association between SB and a single nucleotide polymorphism (SNP), rs6313, in the neuronal serotonin 2A receptor gene (HTR2A), and established human induced pluripotent stem cell (iPSC)-derived neurons from SB patients with a genetic variant. To elucidate the electrophysiological characteristics of SB iPSC-derived neural cells bearing an SB-related genetic variant, we generated ventral hindbrain neurons from SB patients and unaffected controls, and explored the intrinsic membrane properties of these neurons using the patch-clamp technique. We found that the electrophysiological properties of iPSC-derived neurons mature in a time-dependent manner in long-term control cultures. SB neurons exhibited higher action potential firing frequency, higher gain, and shorter action potential half duration. This is the first in vitro modeling of SB using patient-specific iPSCs. The revealed electrophysiological characteristics may serve as a benchmark for further investigation of pathogenic mechanisms underlying SB. Moreover, our results on long-term cultures provide a strategy to define the functional maturity of human neurons in vitro, which can be implemented for stem cell research of neurogenesis, and neurodevelopmental disorders.

Bone marrow ring sideroblasts in hematological diseases: an analysis of consecutive 1300 samples in a single institution.

The incidence of MDS-RS in Japan has been recognized as about 5% which is lower than that in European countries. Insufficient use of iron staining tests in Japan has been noted as one conceivable factor contributing to this apparently lower prevalence. To investigate this issue, we analyzed the proportion of ring sideroblasts (RS) in 1300 bone marrow samples from patients with hematological diseases at Kitasato University Hospital, including iron staining of all samples. Sixteen of 96 patients with MDS (16.7%) were diagnosed with MDS-RS, and this accounted for 26.2% of MDS without excess blasts. Some MDS-EB (22.9%) and AML-MRC (13.8%) patients also had ≥ 15% RS. In contrast, RS were rarely found in myeloid neoplasms without dysplasia and non-myeloid diseases: only 1 in 46 (2.2%) patients with AML without dysplasia, 2 in 93 (2.2%) with MPN, and 8 in 984 (0.8%) with non-myeloid diseases had ≥ 5% RS. These results indicate that prevalence of MDS-RS in Japan may be higher than conventionally recognized and that RS are principally restricted to myelodysplastic disorders. Further multicenter studies using consecutive bone marrow samples with iron staining tests will be required to confirm our findings.

A pilot study to test the validity of a piezoelectric intra-splint force detector for monitoring of sleep bruxism in comparison to portable polysomnography.

PURPOSE: To test the validity of a force-based detection system (ISFD: intra-splint force detector) to record sleep bruxism (SB) in comparison to portable polysomnography (PSG). METHODS: Simultaneous portable PSG recordings with a masseter electromyography (EMG) channel and ISFD with a deformation-sensitive piezoelectric film were performed on six participants with definite SB. First, simulated bruxism behaviors (static clenching, grinding, tapping, and rhythmic clenching) were recorded using both EMG and ISFD. Using these data, interval and duration criteria for ISFD data conditioning were established. Then, portable PSG recordings were conducted with the ISFD during sleep. Using the above criteria, ISFD events were compared with EMG-based SB episodes (the gold standard), and the sensitivity and positive predictive value of ISFD events were calculated. Spearman's correlation coefficients between true-positive ISFD events and SB episodes were then calculated. RESULTS: Among the tested conditioning criteria, a 3-s interval combined with a 1-s duration was selected. The median sensitivity and positive predictive value for the ISFD were 0.861 and 0.585, respectively. The duration of true-positive ISFD events was correlated with that of EMG-based SB episodes (rho = 0.658, P < 0.01). CONCLUSION: ISFD has validity for SB detection and could be an alternative to single-channel EMG-based recordings.

Effects of vibratory feedback stimuli through an oral appliance on sleep bruxism: a 6-week intervention trial.

PURPOSE: Various biofeedback stimulation techniques of managing sleep bruxism (SB) have recently emerged; however, the effect of successive application of vibratory feedback stimulation has not been clarified. This study elucidated the effect of vibration feedback stimulation via an oral appliance (OA) on SB when vibration feedback was applied for 4 weeks. METHODS: This was a prospective, single-arm, open-label, intervention study. Ten participants diagnosed with "definite" SB wore a specially designed OA for 45 nights in a home-setting. A force-based SB detection system, including a pressure-sensitive piezoelectric film placed internally in the OA, triggered a vibrator attached to the OA. Vibratory stimulation was withheld during the first 2-week adaptation period (1st-15th nights), applied during the 4-week stimulation period (16th-43rd nights), and again withheld during the post-stimulation period (44th and 45th nights). The number and duration of SB episodes/hour of sleep were calculated based on masseter electromyographic activity recorded with in-home portable polysomnography and compared between the 15th and 45th nights (without stimulation) and the 17th and 43rd nights (with stimulation). RESULTS: The number and duration of SB episodes significantly decreased after vibratory stimulation (15th vs. 17th nights: p = 0.012 and p = 0.012, respectively), then significantly increased upon cessation of vibratory stimulation after the stimulation period (43rd vs. 45th nights: p = 0.023 and p = 0.023, respectively). CONCLUSION: Contingent vibratory stimulation through an OA may suppress SB-related masticatory muscle activity continuously for 4 weeks and may be an effective alternative for the management of SB. TRIAL REGISTRATION: https://jrct.niph.go.jp/ ; trial registration number: jRCTs032190225.

Patient-reported outcomes of implant-assisted removable partial dentures with magnetic attachments using short implants: A prospective study.

Purpose Implant-assisted removable partial dentures (IARPDs) with short implants improve the oral functions of removable partial dentures (RPDs). This study aimed to compare the patient-reported outcomes of RPDs and IARPDs with short implants retained by magnetic attachments.Methods We recruited 30 participants with mandibular Kennedy Class I or II and distal extension defects of three or more teeth. RPDs, IARPDs with a healing cap, and IARPDs with a magnetic attachment were evaluated across stages using patient-reported outcomes. All participants completed questionnaires (oral health-related quality of life [OHRQoL], patient general satisfaction, and patient's denture assessment [PDA]) at each stage. The OHRQoL was evaluated using the Oral Health Impact Profile-J 54 (OHIP-J 54) score. The general patient satisfaction was evaluated using a 100 mm visual analog scale. The Wilcoxon signed-rank test and Bonferroni correction were used to evaluate differences between the groups (α=0.05).Results The OHRQoL of IARPDs was significantly higher than that of RPDs. IARPDs with a magnetic attachment had significantly better patient general satisfaction and PDA than IARPDs with a healing cap.Conclusions The OHRQoL, patient general satisfaction, and PDA were improved by IARPD with a short implant using a magnetic attachment.

In vitro monitoring of HTR2A-positive neurons derived from human-induced pluripotent stem cells.

The serotonin 5-HT2A receptor (5-HT2AR) has been receiving increasing attention because its genetic variants have been associated with a variety of neurological diseases. To elucidate the pathogenesis of the neurological diseases associated with 5-HT2AR gene (HTR2A) variants, we have previously established a protocol to induce HTR2A-expressing neurons from human-induced pluripotent stem cells (hiPSCs). Here, we investigated the maturation stages and electrophysiological properties of HTR2A-positive neurons induced from hiPSCs and constructed an HTR2A promoter-specific reporter lentivirus to label the neurons. We found that neuronal maturity increased over time and that HTR2A expression was induced at the late stage of neuronal maturation. Furthermore, we demonstrated successful labelling of the HTR2A-positive neurons, which had fluorescence and generated repetitive action potentials in response to depolarizing currents and an inward current during the application of TCB-2, a selective agonist of 5-HT2ARs, respectively. These results indicated that our in vitro model mimicked the in vivo dynamics of 5-HT2AR. Therefore, in vitro monitoring of the function of HTR2A-positive neurons induced from hiPSCs could help elucidate the pathophysiological mechanisms of neurological diseases associated with genetic variations of the HTR2A gene.

Structural equation modeling for factors influencing patients' willingness to replace removable dentures.

PURPOSE: To investigate the factors influencing patients' willingness to replace removable dentures using structural equation modeling (SEM). METHODS: A total of 153 patients who sought consultations for removable dentures self-evaluated denture quality using a visual analog scale (VAS); health-related quality of life using the 36-item Short-Form Health Survey; and oral health-related quality of life using the Oral Health Impact Profile. Dental clinicians evaluated denture quality using a VAS and by assessing the presence of defects. After being informed of various treatments, patients were asked whether they would prefer denture replacement. SEM was applied to analyze the relationships and interactive effects among the variables. RESULTS: The final model showed high goodness-of-fit indices (chi-square/degree of freedom = 1.009, comparative fit index = 1.000, Tucker-Lewis index = 0.999, standardized root mean square residual = 0.421, and root mean square error of approximation = 0.008). SEM demonstrated that two latent constructs indirectly predicted patients' willingness to replace dentures; the standardized total effects of good oral health and poor denture quality were -0.154 and 0.503, respectively. CONCLUSION: These findings provide a unified understanding of the shared decision-making process for denture replacement and highlight the pretreatment assessments that play a relevant role in patient treatment preferences.

Effect of contingent vibratory stimulus via an oral appliance on sleep bruxism after the splint adaptation period.

BACKGROUND: Contingent vibratory feedback stimuli applied by a specially designed oral appliance (OA) have been reported to be effective in reducing sleep bruxism (SB). However, the inhibitory effects of the OA, which occur immediately after OA delivery, may have confounded this finding. OBJECTIVE: This study sought to shed light on the effects of vibratory stimuli on SB after the OA adaptation period, when its inhibitory effects are diminished. METHODS: Fourteen 'definite' SB patients were enrolled. A force-based bruxism detection system was utilised to trigger a vibrator attached to the OA. Masseter electromyographic activity during sleep was recorded at home using portable polysomnography. After using the OA without vibratory stimulus for 16 nights (adaptation period), intermittent vibratory stimuli were applied every other half-hour for four nights (intervention period). Electromyographic activity over 10% of the maximum voluntary contraction was regarded as a SB episode. The number and the total duration of SB episodes per hour of sleep were calculated for the sessions with and without stimuli separately and averaged for four intervention nights. The effects of stimuli on these two variables were evaluated. RESULTS: The number and the total duration of the sessions without stimuli were 5.2 episodes/h and 35.3 s/h, respectively. These values significantly decreased to 3.9 episodes/h and 15.1 s/h (p < .05) for the sessions with vibratory stimuli. CONCLUSION: Contingent vibratory stimulus via an OA may be effective for the management of SB even after adaptation to OA.

A case of triple digestive tract reconstruction in chronic pancreatitis complicated with bile ductal stenosis, duodenal stenosis, and portal vein stenosis: a case report.

BACKGROUND: Although endoscopic interventions for chronic pancreatitis are highly developed, surgery for severe complicated cases such as the coexistence of bile duct, duodenum, and portal vein stenosis is a challenging issue for surgeons. In such instances, pancreaticoduodenectomy could lead to massive intraoperative bleeding due to severe collateral veins. A surgical drainage procedure, instead of pancreatic resection, may be a reasonable and safer option in such cases, but the literature on a surgical drainage technique to resolve all obstructions of the pancreatic duct, bile duct, and duodenum at once is limited. We devised a new surgical drainage method for such cases with consideration for a possible future second surgery for newly developed pancreatic cancer because chronic pancreatitis is a well-known high-risk factor for pancreatic cancer in the long term. Here, we report this surgical procedure. CASE PRESENTATION: A 55-year-old man was diagnosed with alcoholic chronic pancreatitis 15 years ago. Before surgery, he underwent regular endoscopic pancreatic stenting for pancreatic ductal stenosis for 3 years. Three months before surgery, his duodenal stenosis worsened, and he was referred to our department for surgery. Preoperative imaging revealed pancreatic and bile duct stenosis, duodenal stenosis, and portal vein stenosis. To avoid intraoperative bleeding caused by the development of collateral veins, we performed a triple drainage procedure: longitudinal pancreaticojejunostomy with coring-out of the pancreatic head, hepaticojejunostomy, and gastrojejunostomy. The patient did not develop postoperative complications, and he was discharged from the hospital on postoperative day 14. For 5 years after surgery, no abdominal pain or recurrent pancreatitis was observed. CONCLUSION: Our triple drainage procedure seems effective and minimally invasive for patients complicated with bile duct stenosis, duodenal stenosis, and portal vein stenosis.

Building an Automated Orofacial Pain, Headache and Temporomandibular Disorder Diagnosis System.

Physicians collect data in patient encounters that they use to diagnose patients. This process can fail if the needed data is not collected or if physicians fail to interpret the data. Previous work in orofacial pain (OFP) has automated diagnosis from encounter notes and pre-encounter diagnoses questionnaires, however they do not address how variables are selected and how to scale the number of diagnoses. With a domain expert we extract a dataset of 451 cases from patient notes. We examine the performance of various machine learning (ML) approaches and compare with a simplified model that captures the diagnostic process followed by the expert. Our experiments show that the methods are adequate to making data-driven diagnoses predictions for 5 diagnoses and we discuss the lessons learned to scale the number of diagnoses and cases as to allow for an actual implementation in an OFP clinic.

Effects of a contingent vibratory stimulus delivered by an intra-oral device on sleep bruxism: a pilot study.

PURPOSE: Although sleep bruxism (SB) is one of the most important clinical problems in dental practice, there is no definitive method for controlling it. This pilot study evaluated the effects of contingent vibratory feedback stimuli using an occlusal splint for inhibition of sleep bruxism. METHODS: Thirteen subjects with clinically diagnosed SB participated after providing an informed consent. Portable polysomnographic recordings were conducted in the subjects' home environment to make a definitive SB diagnosis and to evaluate the effects of the vibratory stimuli on SB. A force-based bruxism detection system, which used a pressure-sensitive piezoelectric film embedded in the occlusal splint, was utilized to trigger vibration feedback stimuli, which was scheduled to be applied intermittently for 30 min, at 30-min intervals. RESULTS: The number of SB episodes (times/hour), the total SB duration (seconds/hour), the mean duration of SB episodes (seconds/episode), and the micro-arousal index (times/hour) were scored for each time period (with and without vibration). The effects of the vibration on these scores were tested (paired t test; p < 0.05). The number of SB episodes tended to decrease with the vibration stimuli, and the decrease in the total SB duration was statistically significant (14.3 ± 9.5 vs. 26.0 ± 20.0, p = 0.03). No substantial change was found in terms of the micro-arousal index. CONCLUSIONS: These study results suggested that the SB inhibitory system employing a vibratory stimulus might be able to suppress the total SB duration without disturbing sleep.

Association between patterns of jaw motor activity during sleep and clinical signs and symptoms of sleep bruxism.

The aim of this study was to investigate the association between patterns of jaw motor activity during sleep and clinical signs and symptoms of sleep bruxism. A total of 35 university students and staff members participated in this study after providing informed consent. All participants were divided into either a sleep bruxism group (n = 21) or a control group (n = 14), based on the following clinical diagnostic criteria: (1) reports of tooth-grinding sounds for at least two nights a week during the preceding 6 months by their sleep partner; (2) presence of tooth attrition with exposed dentin; (3) reports of morning masticatory muscle fatigue or tenderness; and (4) presence of masseter muscle hypertrophy. Video-polysomnography was performed in the sleep laboratory for two nights. Sleep bruxism episodes were measured using masseter electromyography, visually inspected and then categorized into phasic or tonic episodes. Phasic episodes were categorized further into episodes with or without grinding sounds as evaluated by audio signals. Sleep bruxism subjects with reported grinding sounds had a significantly higher total number of phasic episodes with grinding sounds than subjects without reported grinding sounds or controls (Kruskal-Wallis/Steel-Dwass tests; P < 0.05). Similarly, sleep bruxism subjects with tooth attrition exhibited significantly longer phasic burst durations than those without or controls (Kruskal-Wallis/Steel-Dwass tests; P < 0.05). Furthermore, sleep bruxism subjects with morning masticatory muscle fatigue or tenderness exhibited significantly longer tonic burst durations than those without or controls (Kruskal-Wallis/Steel-Dwass tests; P < 0.05). These results suggest that each clinical sign and symptom of sleep bruxism represents different aspects of jaw motor activity during sleep.