Guideline for evaluating the effects of psychotropic drugs on motor vehicle driving performance in Japan: A tiered approach for the assessment of clinically meaningful driving impairment.

In December 2022, the Ministry of Health, Labour and Welfare (MHLW) of Japan issued and implemented the guideline for evaluating the effects of psychotropic drugs on motor vehicle driving performance. This guideline recommends the use of a tiered approach to assess clinically meaningful driving impairment. It is noted that adverse events cannot be solely explained by pharmacokinetics, as the onset and duration of these events vary. Among these adverse events, those affecting alertness, such as drowsiness caused by psychotropic drugs on driving performance, are more frequently observed during initial treatment stages and dose escalation. Hence, when evaluating the effects of psychotropic drugs on driving performance, it becomes crucial to assess the persistence of clinically meaningful impairment. Therefore, the MHLW guideline, developed by the authors, emphasizes the need to assess the temporal profile of adverse events affecting driving in all clinical trials. Additionally, the guideline states that when conducting driving studies, the timing of multiple dosing should consider not only the pharmacokinetics of the investigational drug but also its tolerance.

Digital clock drawing test reflects visuospatial ability of older drivers.

Objectives: To keep older drivers safe, it is necessary to assess their fitness to drive. We developed a touch screen-based digital Clock Drawing Test (dCDT) and examined the relationship between the dCDT scores and on-road driving performance of older drivers in a community-setting. Methods: One hundred and forty-one community-dwelling older drivers (range; 64-88 years old) who participated in this study were included in the analysis. Participants completed the dCDT, the Mini-Mental State Examination-Japanese (MMSE-J), and an on-road driving assessment. We examined the relationship between dCDT scores using the method by Rouleau et al. (maximum 10 points) and the on-road driving performance based on a driving assessment system originally developed by Nagoya University. Results: Multiple regression analyses showed that errors in the driving test were associated with dCDT score for the items "confirmation," "turning left" and "maintains driving lane position". Discussion: This study confirmed the relationship between the dCDT score and driving errors, such as confirmation, turning left and maintaining driving lane position. The increase in these errors indicates a decline in visuospatial ability while driving. The dCDT score may reflect older drivers' visuospatial abilities while driving.

A mechanism of melanogenesis mediated by E-cadherin downregulation and its involvement in solar lentigines.

OBJECTIVE: Intensive studies have revealed that pleiotropic melanocytic factors are associated with age-spot formation. Dysfunctional keratinocyte differentiation is thought to be an upstream cause of age-spot formation. Although it has been shown that keratinocyte differentiation is mediated by the cell-cell contact factor E-cadherin, its involvement in age-spot formation remains unknown. Thus, to determine the origin of age-spots and an integrated solution for the same, we focused on E-cadherin expression in the present study. METHODS: First, we assessed the solar lentigines in cutaneous and cultured cells by means of immunofluorescence staining. Following that, keratinocytes treated with siRNAs against E-cadherin were co-cultured with melanocytes, and the secreted factors were identified by means of proteomic analysis of the culture supernatants. We also performed quantitative PCR to assess melanogenesis activity and screen ingredients. For behavioural analysis of melanocytes, we performed time-lapse imaging using confocal laser scanning microscopy. RESULTS: E-cadherin expression was downregulated in the epidermis of the solar lentigines, suggesting its involvement in age-spot formation. E-cadherin knocked down keratinocytes not only promoted the secretion of melanocytic/inflammatory factors but also increased melanogenesis by upregulating the expression of melanogenesis factors. Furthermore, live-imaging showed that the downregulation of E-cadherin inhibited melanocyte dynamics and accelerated melanin uptake. Finally, we identified Rosa multiflora fruit extract as a solution that can upregulate E-cadherin expression in keratinocytes. CONCLUSION: Our findings showed that E-cadherin downregulation triggers various downstream melanocytic processes, such as the secretion of melanocytic factors and melanogenesis. Additionally, we showed that the Rosa multiflora fruit extract upregulated E-cadherin expression in keratinocytes.

OBJECTIF: Des études intensives ont révélé que les facteurs mélanocytaires pléiotropiques sont associés à la formation de taches de vieillesse. On pense que la différenciation des kératinocytes dysfonctionnels est une cause en amont de la formation des taches de vieillesse. Bien qu'il ait été démontré que la différenciation des kératinocytes est médiée par le facteur de contact cellule-cellule E-cadhérine, son implication dans la formation des taches de vieillesse reste inconnue. Ainsi, pour déterminer l'origine des taches de vieillesse et une solution intégrée pour celles-ci, nous nous sommes concentrés sur l'expression de la E-cadhérine dans la présente étude. MÉTHODES: Tout d'abord, nous avons évalué les lentigines solaires dans les cellules cutanées et cultivées au moyen d'une coloration par immunofluorescence. Par la suite, les kératinocytes traités avec des siRNA contre l'E-cadhérine ont été co-cultivés avec des mélanocytes, et les facteurs sécrétés ont été identifiés au moyen d'une analyse protéomique des surnageants de culture. Nous avons également effectué une PCR quantitative pour évaluer l'activité de la mélanogénèse et dépister les ingrédients. Pour l'analyse comportementale des mélanocytes, nous avons réalisé une imagerie accélérée à l'aide de la microscopie confocale à balayage laser. RÉSULTATS: L'expression de l'E-cadhérine a été régulée à la baisse dans l'épiderme des lentigines solaires, suggérant son implication dans la formation des taches de vieillesse. Les kératinocytes dans lesquels l'E-cadhérine a été réduite non seulement ont favorisé la sécrétion de facteurs mélanocytaires/inflammatoires, mais ont également accru la mélanogenèse en régulant à la hausse l'expression de facteurs de mélanogenèse. De plus, l'imagerie en direct a montré que la régulation négative de l'E-cadhérine inhibait la dynamique des mélanocytes et accélérait l'absorption de la mélanine. Enfin, nous avons identifié l'extrait de fruit de Rosa multiflora comme une solution capable de réguler positivement l'expression de l'E-cadhérine dans les kératinocytes. CONCLUSION: Nos résultats ont montré que la régulation négative de la E-cadhérine déclenche divers processus mélanocytaires en aval, tels que la sécrétion de facteurs mélanocytaires et la mélanogénèse. De plus, nous avons montré que l'extrait de fruit de Rosa multiflora régulait à la hausse l'expression de l'E-cadhérine dans les kératinocytes.

The new guideline for evaluating effects of psychotropic drugs on the performance to drive a motor vehicle in Japan: Comparison with US FDA guideline.

In December 2022, the new guideline for evaluating the effect of psychotropic drugs on the performance to drive a motor vehicle was issued by the Ministry of Health, Labour and Welfare (MHLW) and implemented in Japan. Of the safety information, information on the influence of medications on driving performance is particularly important because it can be relevant to the social functioning of patients. In principle, the package inserts of medications are designed based on evidence and provide precautions regarding the operation of heavy machinery such as automobiles in Japan, the United States, and Europe. The effects of medications on driving performance are generally evaluated in a tiered approach involving nonclinical and clinical studies. Because of the wide variety of functional domains involved in automobile driving, the selection of evaluation methods for a given medication depends on their characteristics, which is a complicated method. Therefore, to evaluate the effects of psychotropic drugs on driving performance efficiently and appropriately, we developed the MHLW guideline that specifically defines the evaluation methods used in pharmacological studies, the neuropsychological tests used in pharmacodynamic studies, and the situations in which driving studies are necessary. Regarding the planning of appropriate drug development strategies, we review the background of the MHLW guideline and its differences from the US Food and Drug Administration (FDA) guideline.

Glyceraldehyde-derived advanced glycation end-products are associated with left ventricular ejection fraction and brain natriuretic peptide in patients with diabetic adverse cardiac remodeling.

Objectives: Glyceraldehyde-derived advanced glycation end-products (Glycer-AGEs) have a strong binding affinity for their cognate receptor and elicit oxidative stress and inflammation. However, it remains unknown whether the levels of Glycer-AGEs correlate with the severity of cardiac function and heart failure in patients with diabetic adverse cardiac remodeling (DbCR). Fourteen heart failure patients with type 2 diabetes mellitus (DM) without other cardiac disorders (DbCR group) were enrolled. Another 14 patients with idiopathic dilated cardiomyopathy (DCM) without DM were served as a control (DCM group). All patients were assessed for serum Glycer-AGEs, nitrotyrosine (NT), and tumor necrosis factor alpha (TNFα) and for plasma brain natriuretic peptide (BNP). The left ventricular ejection fraction (LVEF) was evaluated by echocardiography. Results: The mean serum levels of Glycer-AGEs, NT, and TNFα in the DbCR group were significantly higher than those in the DCM group (for Glycer-AGEs, p = .0073; for NT, p = .005; for TNFα, p < .0001, respectively). In the patients with DbCR, the levels of serum Glycer-AGEs and TNFα were closely associated with LVEF and BNP values. Conclusions: Both Glycer-AGEs and TNFα showed close associations with LVEF and the levels of BNP in patients with DbCR. Glycer-AGEs and TNFα may play a pathological role in the development of DbCR.

Assessment of senior drivers' internal state in the event of simulated unexpected vehicle motion based on near-infrared spectroscopy.

OBJECTIVE: A driver's internal state is a critical factor influencing driving performance, especially in cases of surprise or shock in response to unexpected incidents while driving. This study was designed to investigate the brain activity of a senior driver in response to simulated unexpected vehicle motion, compared with a relaxed state and normal driving. METHODS: To accomplish this, we created a driving simulator paradigm wherein participants were involved in one of the following three scenarios: sitting down and relaxing, normal driving around the city with traffic signals and other vehicles, and the exiting of a parking area. In the scenario where the driver was to exit the parking area, the gear was switched automatically by the CarMaker software without the driver being notified, leading to an unexpected condition. The driver's internal states were classified by artificial intelligence, based on information obtained through four-channel near-infrared spectroscopy. RESULTS: Significant differences were observed between the hemodynamic responses obtained in the three conditions. Ultimately, this method can be used to update advanced driver assistance systems, with a view to preventing future traffic accidents, by activating in-vehicle safety functions based on the driver's condition. CONCLUSIONS: A driver's internal states in a panic situation while driving can be detected using near-infrared spectroscopy and artificial intelligence.

Possibly Late-Onset Arrhythmogenic Right Ventricular Cardiomyopathy: Unique Triglyceride Deposition by Analysis of Lipid Contents.

We presented an unusual arrhythmogenic right ventricular cardiomyopathy (ARVC) case of a late-60s elderly man's death, due to severe pericardial/pleural effusion and ascites, and arrhythmic events, with unique pathological features. The hypertrophic heart grossly displayed yellowish to yellow-whitish predominantly in the variably thinned wall of the dilated right ventricle. Microscopic findings showed diffuse fatty/fibrofatty replacement in not only the right but left ventricular myocardium, together with an outer lymphoplasmacytic infiltrate. According to the lipid contents analysis, the triglyceride content, but not the cholesterol content, in our patient's right and left ventricular cardiac muscle was much higher than that in the control subject. We propose that this unique triglyceride deposition in our possibly late-onset ARVC case might be one of new clues to understand its enigmatic cause. Further prospective studies are needed to validate the presence and significance of a greater volume of triglyceride deposit, after collecting and investigating a larger number of early and late-onset ARVC cases examined.

A Novel Method for Classifying Driver Mental Workload Under Naturalistic Conditions With Information From Near-Infrared Spectroscopy.

Driver cognitive distraction is a critical factor in road safety, and its evaluation, especially under real conditions, presents challenges to researchers and engineers. In this study, we considered mental workload from a secondary task as a potential source of cognitive distraction and aimed to estimate the increased cognitive load on the driver with a four-channel near-infrared spectroscopy (NIRS) device by introducing a machine-learning method for hemodynamic data. To produce added cognitive workload in a driver beyond just driving, two levels of an auditory presentation n-back task were used. A total of 60 experimental data sets from the NIRS device during two driving tasks were obtained and analyzed by machine-learning algorithms. We used two techniques to prevent overfitting of the classification models: (1) k-fold cross-validation and principal-component analysis, and (2) retaining 25% of the data (testing data) for testing of the model after classification. Six types of classifier were trained and tested: decision tree, discriminant analysis, logistic regression, the support vector machine, the nearest neighbor classifier, and the ensemble classifier. Cognitive workload levels were well classified from the NIRS data in the cases of subject-dependent classification (the accuracy of classification increased from 81.30 to 95.40%, and the accuracy of prediction of the testing data was 82.18 to 96.08%), subject 26 independent classification (the accuracy of classification increased from 84.90 to 89.50%, and the accuracy of prediction of the testing data increased from 84.08 to 89.91%), and channel-independent classification (classification 82.90%, prediction 82.74%). NIRS data in conjunction with an artificial intelligence method can therefore be used to classify mental workload as a source of potential cognitive distraction in real time under naturalistic conditions; this information may be utilized in driver assistance systems to prevent road accidents.

SmartEye and Polhemus data for vestibulo-ocular reflex and optokinetic reflex model.

In this data article, this dataset included raw data of head and eye movement that collected by Polhemus (Polhemus Inc) and SmartEye (Smart Eye AB) equipment. Subjects who have driver license participated in this experiment. The experiment was conducted with a driving simulator that was controlled by CarSim (Mechanical simulation Co., Anna Arbor, MI) with the vehicle motion. This data set not only contained the eye and head movement but also had eye gaze, pupil diameter, saccades, and so on. It can be used for the parameter identification of the vestibulor-ocular reflex (VOR) model, simulation eye movement, as well as running other analysis related to eye movement.

A multicenter, retrospective, observational study of the clinical outcomes and risk factors for relapse of ulcerative colitis at 1 year after leukocytapheresis.

BACKGROUND: Extracorporeal leukocytapheresis (LCAP) is effective for inducing remission of ulcerative colitis (UC). This retrospective observational study aimed to evaluate the clinical outcome at 1 year and identify risk factors for relapse of UC after LCAP. METHODS: Patients with active UC treated with LCAP between 2010 and 2012 were enrolled from 54 medical facilities in Japan. Clinical data evaluated at 1 year after the last LCAP session included the incidence of relapse, 1-year cumulative relapse-free rate, risk factors for relapse, and history of re-induction treatment following relapse. Relapse was defined by the addition of treatment to induce remission. The primary endpoint was the 1-year cumulative relapse-free rate. Secondary endpoints were risk factors for relapse and outcomes of re-induction treatment after relapse. RESULTS: For 314 patients, the 1-year cumulative relapse-free rate was 63.6%. Following LCAP, a Lichtiger clinical activity index (CAI) of 3 or 4 and high leukocyte count (cut-off value: 7790/mm3) were associated with a greater risk of relapse. Intensive LCAP (≥4 sessions within the first 2 weeks) was associated with favorable long-term outcomes in corticosteroid-refractory patients. The response rate was 85.1% among 30 patients who required re-treatment with LCAP. CONCLUSIONS: The majority of patients (>60%) with UC treated with LCAP achieved clinical remission within 1 year and remained relapse-free. A higher Lichtiger CAI and leukocyte count following LCAP were risk factors for relapse. Re-induction therapy with LCAP was effective for relapse of UC.

Diurnal glycemic fluctuation is associated with severity of coronary artery disease in prediabetic patients: Possible role of nitrotyrosine and glyceraldehyde-derived advanced glycation end products.

BACKGROUND: Glucose fluctuation (GF) is a risk factor for coronary artery disease (CAD). However, it remains unknown whether specific indices of GF are risk factors for CAD. Therefore, we evaluated the relationship between GF, as determined by a continuous glucose monitoring system (CGMS) or the glucose level at 2h after a 75-g oral glucose tolerance test (75g OGTT 120), and the severity of CAD in prediabetic patients. We also evaluated whether nitrotyrosine (NT) and glyceraldehyde-derived advanced glycation end-products (Glycer-AGE) were induced by GF. METHODS: Twenty-eight prediabetic patients underwent coronary angiography (CAG), and the Gensini score and the SYNTAX score were evaluated as the severity of CAD, while the mean amplitude of glycemic excursions (MAGE) by CGMS and 75g OGTT 120 were evaluated. Serum NT and Glycer-AGE were measured. RESULTS: The MAGE was closely associated with the Gensini score (r=0.742, p<0.001) and the SYNTAX score (r=0.776, p<0.001), respectively. The 75g OGTT 120 was not associated with the Gensini score (r=0.36, p=0.06), but it was significantly associated with the SYNTAX score (r=0.413, p=0.036). Multiple linear regression analysis showed that the MAGE was the only independent determinant for the severity of CAD. The levels of NT and Glycer-AGE were significantly higher in the high MAGE group than in the low MAGE group. CONCLUSIONS: Diurnal GF is associated with the severity of CAD, even in prediabetic patients. GF, NT, and Glycer-AGE may play a pathological role in the progression of CAD.

Prediction of all-cause death using (11)C-hydroxyephedrine positron emission tomography in Japanese patients with left ventricular dysfunction.

OBJECTIVES: The aim of this study was to determine whether (11)C-hydroxyephedrine ((11)C-HED) can predict adverse events including all-cause death in Japanese patients with left ventricular (LV) dysfunction. BACKGROUND: Although (11)C-HED PET has been used to assess cardiac sympathetic innervation in various disease conditions, data on their prognostic value are limited. METHODS: Sixty patients (mean LVEF, 42 ± 14 %) with LV dysfunction (42 ischemic and 18 non-ischemic heart disease) underwent (11)C-HED PET. Myocardial retention was calculated for (11)C-HED PET as a measure of cardiac sympathetic neuronal integrity. Statistical analysis was performed using Cox proportional hazards regression and log-rank test. RESULTS: Thirteen deaths (7 cardiac and 6 non-cardiac deaths) occurred during a mean follow-up period of 33 ± 23 months. The patients with death were associated with significantly lower (11)C-HED retention (7.1 ± 2.1 vs 9.0 ± 2.4, p = 0.015) than those without death. The hazard ratio for global (11)C-HED retention per unit (/min) was 0.762 (p = 0.039), which remained significant in multivariate analysis. When the patients were divided into the high (≥8.5) and low (<8.5) (11)C-HED retention groups, the low (11)C-HED retention group was associated with significantly poorer survival than the high (11)C-HED retention group (p = 0.004). CONCLUSION: The low global (11)C-HED retention is a marker of poor overall survival in patients with LV dysfunction in this study.

Chronic total occlusions of the right coronary and left anterior descending coronary arteries in a young adult patient with antiphospholipid syndrome.

A 36-year-old male appeared to have an old myocardial infarction on electrocardiogram, and coronary angiography (CAG) was performed. The CAG showed total occlusions of the right coronary artery and left anterior descending artery. He was successfully treated with drug-eluting stent implantation for both occluded coronary arteries. Such serious coronary lesions are uncommon for his young age. The patient was diagnosed as having antiphospholipid syndrome (APS) based on elevation of anticardiolipin antibody and anti-ß2 glycoprotein I antibody. Two years after stent implantation, the patient was well without ischemia or thrombosis. APS should be considered a potential cause of serious coronary disease in young adults. .

Gait generation for powered Hip-Ankle-Linkage-Orthosis.

A hip-knee-ankle-foot orthotic system called `HALO'(Hip and Ankle Linked Orthosis) for paraplegic walking has been developed in our previous study. Each ankle joint of the HALO system is linked with a medial single joint via a wire which allows both feet of the orthosis to stay always parallel to the floor during walking and assists swinging the leg. The tests of the HALO system demonstrated that it allows smoother walking and easy don/doff. In order to improve further the characteristics of the previous design, we started a new project called pHALO aiming at further reducing of the energy expenditure during walking. As a difference from the previous solution where ankle joints were restrained, the new solution will incorporate two actuators to control the ankle joints angles. As an intermediate step from the development of the pHALO system, in this study we added to the existing system a feedback PI controller to control the ankle joint angle of the right foot in the push-off phase and conducted an experiment to evaluate the effect of the new design on the walking patterns and energy efficiency. The results showed longer stride length, faster gait speed, smaller variation of the CoG, and less energy consumption.

A large-scale, prospective, observational study of leukocytapheresis for ulcerative colitis: treatment outcomes of 847 patients in clinical practice.

BACKGROUND AND AIMS: Leukocytapheresis is an extracorporeal therapy for ulcerative colitis. However, no large-scale study on leukocytapheresis has been reported. This large-scale, prospective, observational study aimed to evaluate the treatment outcomes of leukocytapheresis for active ulcerative colitis in clinical practice. METHODS: Patients with active ulcerative colitis treated with leukocytapheresis using a Cellsorba E column between May 2010 and December 2012 were enrolled from 116 medical facilities in Japan. RESULTS: A total of 847 patients were enrolled, and 623 were available for efficacy analysis. Out of 847 patients, 80.3% of the patients had moderate to severe disease activity, and 67.6% were steroid refractory. As concomitant medications, 5-aminosalicylic acids, corticosteroids, and thiopurines were administered to 94.8%, 63.8%, and 32.8% of the patients, respectively. In addition, infliximab and tacrolimus were concomitantly used in 5.8% and 12.3%, respectively. Intensive leukocytapheresis (≥4 leukocytapheresis sessions within the first 2 weeks) was used in >70% of the patients. Adverse events were seen in 10.3% (87/847), which were severe in only 5 patients (0.6%). Any concomitant medications did not increase the incidence of adverse events. Intensive leukocytapheresis was as safe as the conventional weekly procedure. The overall clinical remission rate was 68.9% (429/623), and the mucosal healing rate was 62.5% (145/232). Clinical remission was achieved more frequently and rapidly in the intensive group than in the weekly group. CONCLUSIONS: This large-scale study indicates that leukocytapheresis, including intensive procedure, is a safe and effective therapeutic option for active ulcerative colitis.

Increased levels of the oxidative stress marker, nitrotyrosine in patients with provocation test-induced coronary vasospasm.

BACKGROUND: Endothelial dysfunction of the coronary arteries caused by oxidative stress plays an important role in the pathogenesis of coronary vasospasm. However, it is not clear whether circulating biomarkers for oxidative stress are altered after coronary vasospasm. We investigated temporal changes in the levels of oxidative stress biomarkers after coronary vasospasm induced by intracoronary acetylcholine provocation testing, resulting in transient myocardial ischemia. METHODS AND RESULTS: Thirty consecutive patients with suspected vasospastic angina pectoris (VSAP) were enrolled in the study. Patients were categorized into the VSAP-positive group (n=14) and the VSAP-negative group (n=16) on the basis of test results. Serum samples were examined for the levels of the oxidative stress markers 4-hydroxynonenal (HNE) and nitrotyrosine (NT) before, and 15min, 3h, and 12h after the provocation test. The serum HNE levels did not change in either group after the test. The serum NT levels in the VSAP-positive group significantly increased at 3h and 12h after the test (11.3±3.3µg/ml at 3h, p=0.015, and 12.1±5.7µg/ml at 12h, p=0.03), as compared with baseline (8.1±3.2µg/ml). In the VSAP-negative group, the serum NT levels significantly decreased from baseline at each of the 3 time points. CONCLUSIONS: Serum NT significantly increased after coronary vasospasm induced by acetylcholine provocation, suggesting that serum NT could be a biomarker of transient myocardial ischemia and could contribute to the development of VSAP.

Nutri-pharmacogenomics of warfarin anticoagulation therapy: VKORC1 genotype-dependent influence of dietary vitamin K intake.

Warfarin is the most widely prescribed oral anticoagulant, but large interindividual variations exist in the dose required to achieve comparable therapeutic effects. Several clinical and genetic variables have been identified that influence warfarin dosing. However, interactions between genotype and nutrition remain uncertain in terms of dietary vitamin K intake. To investigate genotype-nutrient interactions in warfarin anticoagulation therapy, 202 consecutive outpatients (M/F = 142/60, mean age, 69 years) undergoing treatment with warfarin were enrolled. Prevalent single nucleotide polymorphisms in VKORC1 and CYP2C9 were genotyped, and dietary vitamin K intake during the week preceding the blood sampling was quantitatively estimated by a dietitian-assisted questionnaire. Patients were classified according to low, medium, or high vitamin K intake. The mean daily warfarin dose in subjects with a VKORC1-1639 A/A genotype was significantly smaller than that with a -1639A/G genotype (2.74 vs. 3.91 mg/day, respectively, p < 0.0001). Dose requirements did not differ between subjects with a CYP2C9 *1/*3 genotype versus a CYP2C9 *1/*1 genotype. In subjects with a variant VKORC1-1639 G allele, the mean daily warfarin dose was significantly attenuated by low vitamin K intake compared with medium and high intake after adjustment for covariates (3.4 vs. 5.0 vs. 4.0 mg/day, respectively, p = 0.028). No such genotype effects were observed in homozygous patients for the VKORC1-1639 A allele. The results of the present study suggest that the capacity of dietary vitamin K intake to influence warfarin dose requirements during anticoagulation therapy is VKORC1 genotype-dependent, at least in part.

Myocardial sympathetic innervation, function, and oxidative metabolism in non-infarcted myocardium in patients with prior myocardial infarction.

OBJECTIVE: The purpose of this study was to investigate the relationship between sympathetic innervation, contractile function, and the oxidative metabolism of the non-infarcted myocardium in patients with prior myocardial infarction. METHODS: In 19 patients (14 men, 5 women, 65 ± 9 years) after prior myocardial infarction, sympathetic innervation was assessed by (11)C-hydroxyephedrine (HED) positron emission tomography (PET). Oxidative metabolism was quantified using (11)C-acetate PET. Left ventricular systolic function was measured by echocardiography with speckle tracking technique. RESULTS: The (11)C-HED retention was positively correlated with left ventricular ejection fraction (LVEF) (r = 0.566, P < 0.05), and negatively with peak longitudinal strain in systole in the non-infarcted myocardium (r = -0.561, P < 0.05). Kmono, as an index of oxidative metabolism, was significantly correlated with rate pressure product (r = 0.649, P < 0.01), but not with (11)C-HED retention (r = 0.188, P = 0.442). Furthermore, there was no significant correlation between Kmono and LVEF (r = 0.106, P = 0.666) or peak longitudinal strain in systole (r = -0.256, P = 0.291) in the non-infarcted myocardium. When the patients were divided into two groups based on the median value of left ventricular end-systolic volume index (LVESVI) (41 mL), there were no significant differences in age, sex, and rate pressure product between the groups. However, the large LVESVI group (>41 mL) was associated with reduced (11)C-HED retention and peak longitudinal strain in systole, whereas Kmono was similar between the groups. CONCLUSIONS: This study indicates that remodeled LV after myocardial infarction is associated with impaired sympathetic innervation and function even in the non-infarcted myocardial tissue. Furthermore, oxidative metabolism in the non-infarcted myocardium seems to be operated by normal regulatory mechanisms rather than pre-synaptic sympathetic neuronal function.

Ryanodine receptors are expressed in epidermal keratinocytes and associated with keratinocyte differentiation and epidermal permeability barrier homeostasis.

Ryanodine receptors (RyRs) have an important role as calcium channels in the regulation of intracellular calcium levels in the nervous system and muscle. In the present study, we investigated the expression of RyR in human epidermis. Immunohistochemical studies and reverse transcription-PCR indicated the expression of RyR type 1, 2, and 3 proteins in epidermal keratinocytes. The expression level of each RyR subtype was higher in differentiating keratinocytes than in proliferative cells. We also demonstrated the functional expression of RyR by calcium imaging. In cultured human keratinocytes, application of the RyR agonist 4-chloro-m-cresol (CMC) induced elevation of the intracellular calcium concentration, and co-application of the RyR antagonist 1,1'-diheptyl-4,4'-bipyridinium dibromide (DHBP) blocked the elevation. Application of CMC accelerated keratinocyte differentiation in vitro. On the other hand, topical application of CMC after tape-stripping of hairless mouse skin delayed barrier recovery, whereas application of an RyR antagonist, dantrolene or DHBP, accelerated the barrier recovery. These results suggest that RyR expressed in epidermal keratinocytes is associated with both differentiation of keratinocytes and epidermal barrier homeostasis.