Cyclophosphamide exposure factors in family caregivers for pediatric cancer patients.

The exposure of family caregivers to anticancer drugs for pediatric patients with malignancy is a potential health risk that needs to be minimized. We monitored the amount of cyclophosphamide (CPM) that had adhered to the undershirts of patients and the personal protective equipment (PPE) of family caregivers as well as the caregivers' urine levels of CPM within the first three days after the first and second courses of high-dose CPM therapy. Liquid chromatography/mass spectrometry (LC/MS/MS) detected >0.03 ng/ml of CPM in 26% (23/88) of urine samples from 8 of 11 (72.7%) patients' family caregivers, with a peak of 0.7 ng/ml from 24 to 48 h after administration. Since urine CPM concentrations in family caregivers varied after the first and second courses, the exposure risk factors were analyzed by scoring the PPE-wearing time index (caring minutes × PPE points from wearing masks, gloves, and/or gowns) and CPM adhesion of PPE items with the caring patterns of diaper change, washing body care, oral care, eating assistance, emotional support, and co-sleeping. The closest association was observed for CPM adhesion between oral care gloves and undershirts (correlation coefficient 0.67, p = 0.001). The mixed-effect model analysis indicated only a significant correlation between the PPE-wearing time index and emotional care (playing, cuddling, and physical contact) (p = 0.016). These results suggest that prolonged emotional support results in poor PPE protection, which increases the risk of exposure in family caregivers. Strict PPE care within 48 h after high-dose CPM controls the exposure to high-risk anticancer drugs in caregivers of pediatric patients.

A clinical assessment of portable point-of-care testing for quick cortisol assay during adrenal vein sampling.

This study assessed the clinical performance of point-of-care testing (POCT) for quick cortisol assay (QCA) during adrenal vein sampling (AVS) using a newly invented portable quantitative assay instrument. An observational study was conducted prospectively at two centres in Japan. Forty-eight patients with primary aldosteronism considered for adrenalectomy were enrolled in this study and underwent AVS. Three basal adrenal vein samples from each adrenal vein and two from the inferior vena cava were collected sequentially. The cortisol concentration of adrenal vein samples was measured by routine method and QCA. A total of 338 adrenal vein samples were analysed from 250 sites to determine AVS success or failure. The distribution of turnaround time of the QCA for AVS success or failure followed a normal distribution with an average of 20.5 min. A positive correlation between the routine method and QCA was observed regarding cortisol concentration or selectivity index. No significant difference between the two methods was observed regarding the success rate of AVS. Using the routine method as a reference, the sensitivity and specificity of AVS success or failure were 99.1% (210/212) and 81.6% (31/38), respectively. Easy, quick, portable, and precise POCT-QCA demonstrated its compatibility with routine methods regarding clinical performance.

Effects of Remimazolam on Intracellular Calcium Dynamics in Myotubes Derived from Patients with Malignant Hyperthermia and Functional Analysis of Type 1 Ryanodine Receptor Gene Variants.

Remimazolam is a novel general anesthetic and its safety in patients with malignant hyperthermia (MH) is unknown. We used myotubes derived from the skeletal muscle of patients with MH to examine the response to ryanodine receptor 1 (RYR1) agonist and remimazolam in MH-susceptible patients. Patients underwent muscle biopsy for the Ca2+-induced Ca2+ release (CICR) rate test, a diagnostic tool for MH in Japan. Ten patients had myotubes obtained from skeletal muscle cultures, and the genes associated with malignant hyperthermia in these patients were analyzed. The EC50 of caffeine, cresol, and remimazolam to induce intracellular calcium concentration change were compared between myotubes from CICR-negative genetic test patients and myotubes from other patients. Eight of the ten were CICR-positive, five of whom had RYR1 causative gene mutations or variants. Two patients had CICR-negative genetic tests, and as expected had the highest EC50 (the concentration of a drug that gives a half-maximal response) in response to caffeine, 4CmC and remimazolam. Three patients had a positive CICR but no known variants in RYR1 or CACNA1S (voltage-gated calcium channel subunit alpha1S). Myotubes in these patients had significantly lower EC50s for all agents than myotubes in CICR-negative patients. When myotubes from a patient who was CICR-negative and had no gene variant were used as a control, myotubes from CICR-positive patients were more hyper-responsive than controls to all stimulants used. The EC50 for remimazolam was lowest for myotubes from CICR-positive, RYR1-mutant patients, at 206 µM (corresponding to 123 µg/mL). The concentration was more than 80-times higher than the clinical concentration. RYR1 gene variants in R4645Q and W5020G were shown to be causative gene mutations for MH. Intracellular calcium in myotubes from MH patients are elevated at high concentrations of remimazolam but not at clinically used concentrations of remimazolam. Remimazolam appears to be safe to use in patients with MH.

Functional characterization of RYR1 variants identified in malignant hyperthermia susceptible individuals.

Malignant hyperthermia is a pharmacogenetic disorder triggered by halogenated anesthetic agents in genetically predisposed individuals. Approximately 70 % of these individuals carry mutations in RYR1, the gene encoding the ryanodine receptor calcium channel of skeletal muscle. In this study, we performed functional analysis of 5 RYR1 variants identified in members from 8 families who had been diagnosed by the IVCT. Of the 68 individuals enrolled in the study, 43 were diagnosed as MHS, 23 as MHN, and 2 individuals were not tested. Here we demonstrate that the 5 RyR1 variants cause hypersensitivity to RyR1 agonist-mediated calcium release. According to the EMHG scoring matrix these five genetic variants can be classified as follows: c.8638G>A (p.E2880K) and c.11314C>T (p.R3772W) likely pathogenic, c.11416G>A (p.G3806R), c.14627A>G (p.K4876R) and c.14813T>C (p.I4938T), pathogenic (RefSeq NM_000540.3). We propose that the newly functionally characterized RYR1 variants, be included in the panel of variants to be used for the molecular diagnosis of MHS.

The Usefulness of a Smartphone App-Based Smoking Cessation Program for Conventional Cigarette Users, Heated Tobacco Product Users, and Dual Users: Retrospective Study.

BACKGROUND: Heated tobacco products (HTPs) are widespread in Japan, and smoking cessation of such products has become an important issue owing to the spread of harmful effects from HTPs. The efficacy of online digital therapy has been reported in smoking cessation treatment; however, we have limited evidence of online smoking cessation programs for HTP users. OBJECTIVE: In this study, we evaluate the usefulness of the Ascure program for HTP users (defined as exclusive HTP use or dual use of HTP and cigarettes) compared with exclusive cigarette users. METHODS: This was a retrospective study. We recruited adult smokers participating in the Ascure online smoking cessation program in Japan from June 2019 to February 2021. The Ascure smartphone app provided four elements: (1) educational video tutorials to enhance the understanding of nicotine dependence, (2) a personalized to-do list for behavior change, (3) a digital diary for record keeping, and (4) interactive chat sessions for relief from cravings or withdrawal symptoms. The primary outcome was the continuous abstinence rate (CAR) at weeks 21 to 24, biochemically validated using salivary cotinine testing. We considered those who dropped out of the program as smoking cessation failures. We analyzed the primary outcome using inverse probability weighting against tobacco product type estimated by multinomial propensity scores. We also assessed CAR at weeks 9 to 12 and program adherence. RESULTS: We analyzed data from 2952 participants, including 52% (1524/3478) in the cigarette group, 35% (1038/3478) in the HTP group, and 13% (390/3478) in the dual-use group, who had a mean age of 43.4 (SD 10.8) years and included 17% (513/2952) women. CAR at weeks 21 to 24 showed that exclusive HTP users were more likely to stop tobacco use than exclusive cigarette smokers (CAR 52.6% for cigarette users vs CAR 64.8% for HTP users; odds ratio [OR] 1.17, 95% CI 1.12-1.22; P<.001). There was no significant difference between the exclusive cigarette users and the dual users (CAR 52.6% for cigarette users vs CAR 48.7% for dual users; OR 0.99, 95% CI 0.93-1.05; P=.77). CAR at weeks 9 to 12 was 56.7% (95% CI 54.2%-59.2%) for the exclusive cigarette users, 68.3% (95% CI 65.5%-71.1%) for the exclusive HTP users, and 58.2% (95% CI 53.3%-63.1%) for the dual users. The program adherence rate at week 24 was 70.7% overall (68.4% for cigarette users, 75% for HTP users, and 67.9% for dual users). CONCLUSIONS: Exclusive HTP users had higher CARs and adherence compared with exclusive cigarette users, indicating a higher affinity for the Ascure online smoking cessation program. This program might be a useful smoking cessation option for HTP users, as well as for cigarette smokers.

Electroencephalogram evaluation of accidental cerebral congestion during unexpected superior vena cava clamping: a case report.

BACKGROUND: Intraoperative superior vena cava (SVC) clamping causes hypotension and cerebral congestion. There is no established method for monitoring brain function during cerebral congestion. We encountered a case of cerebral congestion caused by unexpected SVC clamping. CASE PRESENTATION: A 64-year-old man underwent SVC clamping during lung tumor resection. The entropy and electroencephalogram monitoring values decreased with SVC clamping and increased in response to the release of congestion by phlebotomy and SVC declamping. CONCLUSIONS: Because entropy sharply reflects brain viability during cerebral congestion, it was considered helpful in evaluation of the monitoring of cerebral congestion.

The effects of dantrolene in the presence or absence of ryanodine receptor type 1 variants in individuals predisposed to malignant hyperthermia.

Dantrolene is currently the only drug known to specifically treat malignant hyperthermia (MH) crises. Although dantrolene attenuates Ca2+ disorders by acting mainly on the ryanodine receptor type 1 (RYR1), some patients who manifest MH without RYR1 variants have also been successfully treated with dantrolene. Thus, dantrolene appears to have an inhibitory effect on patients with and without RYR1 variants. This study aimed to investigate whether the effects of dantrolene differed depending on the presence or absence of RYR1 variants using muscle cells from MH-predisposed individuals. The study participants were individuals diagnosed with MH predisposition by the Ca2+-induced Ca2+ release rate test. They were genetically tested and divided into two groups: with and without RYR1 variants. We investigated whether these two groups showed differences in the changes in the half-maximal effective concentration (EC50) for caffeine and the resting intracellular Ca2+ concentration ([Ca2+]i) before and after dantrolene administration. Dantrolene administration significantly increased the EC50 (P < 0.0001) and decreased the resting [Ca2+]i (P < 0.0001). The inhibitory effects of dantrolene and the presence of RYR1 variants showed no statistically significant interactions related to the EC50 (P = 0.59) and resting [Ca2+]i (P = 0.21). In conclusion, the presence or absence of RYR1 variants does not appear to influence the effect of dantrolene.

Intravenous patient-controlled analgesia does not increase the risk of postoperative delirium compared to patient-controlled epidural analgesia: a propensity score-matched retrospective cohort study.

BACKGROUND: It is unclear whether the doses of opioids and the routes of administration used for postoperative analgesic management are associated with delirium. We aimed to compare the incidence of postoperative delirium (POD) between intravenous patient-controlled analgesia (IVPCA) and patient-controlled epidural analgesia (PCEA) in patients who underwent postoperative analgesic management using opioids. METHODS: We retrospectively investigated surgical patients (n=3,324) who received patient-controlled analgesia (PCA). Morphine was used for IVPCA, and fentanyl and ropivacaine were used for PCEA. The patients' background characteristics, perioperative management, presence of POD, and postoperative analgesia technique after IVPCA (n=1,184) or PCEA (n=2,140) were assessed. We divided the patients into IVPCA and PCEA groups and compared the incidence of POD by propensity score matching. We used the independent t-test for comparisons between the groups, and P<0.05 as considered as statistically significant. RESULTS: POD was noted in a total of 125 patients (3.8%); 55 patients (4.6%) with IVPCA and 70 patients (3.3%) with PCEA (P=0.046). There was no statistically significant difference in cumulative opioid usage up to postoperative day 2 (in mg) between patients with and without POD (POD 62.7±39.8 vs. non-POD 48.9±50.3, P=0.10). After propensity score matching, 1,156 patients with similar baseline characteristics were selected. POD was noted in 22 of 578 patients (3.8%) in the IVPCA group and 30 of 578 patients (5.2%) in the PCEA group, with no difference between the two groups (P=0.256). On the other hand, opioid usage was higher in the IVPCA group than in the PCEA group (P<0.001). CONCLUSIONS: There was no difference in the incidence of POD between morphine IVPCA and fentanyl PCEA when the patient characteristics were matched using propensity score matching. POD occurs regardless of the route and dose of opioid administration.

[Environmental factors for the development of hematopoietic neoplasms in children].

Parental age at birth has been investigated in patients diagnosed with pediatric cancer. The Japan Children's Cancer Registry1985-2007 recruited 5,510 patients with leukemia and 8,782 with other cancers. The proportion of patients born to mother and father aged >40 years showed a higher trend in leukemia than that in other cancers (odds ratio [OR] 1.41, p=0.057), especially in <12-month-old infants born to mother aged >40 years (OR 2.55, p=0.031). We then divided 27,335 patients diagnosed in 1969-2006 into every 8-year birth cohorts to compare proportions of mothers with prenatal medical irradiation. The OR of leukemia was higher than that of other cancers in 1969-1976 (1.25) or 1977-1984 (1.39), which reached statistical significance. We have also studied caregiver's exposure to anticancer drugs. In 15 pediatric patients with cancer who received cyclophosphamide (CPM), the concentration was measured using mothers and medical staff's urine. Five of 7 infants' and 2 of 8 adolescent's mothers showed increased urine CPM levels. CPM was not detected in any medical staff's samples. Maternal exposure to anticancer drugs should also be considered. Efforts of reducing the genotoxicity in both infants and mothers are crucial for pediatric cancer prevention.

Relationship Between the Loaded Pressure and Flow Rate of Packed Red Blood Cells and Various Infusion Solutions in Normal Infusion Lines and Catheters.

BACKGROUND: We investigated the relationship between the loaded pressure and flow rate in various catheters and the entire infusion line including the catheters, in several infusion solutions and packed red blood cells. METHODS: We connected the infusion line and catheter to the infusion solution and used an outer pressure bag or a compressor to pressurize the infusion solution bag to a pressure within the clinical (up to 450 mm Hg) or higher range (up to 1050 mm Hg). We approximated the relationship between the loaded pressure and flow rate in the entire infusion line including the catheter, versus the catheter alone, as a power function and compared the power numbers. RESULTS: In the clinical pressure range of normal saline, the power numbers of the entire infusion line for the 24-, 22-, 20-, and 18-gauge catheters were 0.76, 0.82, 0.81, and 0.86, respectively, while those for the catheter alone were 0.67, 0.63, 0.56, and 0.44, respectively. In the higher pressure range of normal saline, the power numbers of the entire infusion line for the 24-, 22-, 20-, and 18-gauge catheters were 0.68, 0.70, 0.71, and 0.73, respectively, while those for the catheter alone were 0.62, 0.61, 0.59, and 0.58, respectively. As the power number of the entire infusion line was closer to 1.00 than the values of the catheter, the relation between the loaded pressure and the flow rate was more linear in the entire infusion line than that in the catheter. Similar results were obtained using packed red blood cells and 40% glycerin mixture in normal saline. CONCLUSIONS: Regardless of the type of infusion solution or transfusion, the pressure-flow relationship in the catheter was nonlinear and not directly proportional. However, within the clinical pressure range (up to 450 mm Hg), the relationship between the flow rate and pressure in the entire infusion line was almost linear and proportional.

Primary Aldosteronism with Parathyroid Hormone Elevation: A Single-center Retrospective Study.

Objective Primary aldosteronism (PA) is a major cause of secondary hypertension. The association between PA and other hormone disorders is unclear. The present study aimed to evaluate whether the parathyroid hormone (PTH) value is associated with PA subtypes or specific treatments. Methods We enrolled 135 patients with PA who had their PTH value measured before undergoing a specific treatment. We evaluated whether PTH value is associated with PA subtypes or with specific treatments. The present study is a single-center retrospective study (2011-2018). Results Our study showed that, among the patients with PA, the proportion of those with PTH elevation was >30%. The PTH value was significantly correlated with both the basal plasma aldosterone concentration (PAC) and PAC after a captopril challenge test. However, the PTH value was not significantly different between the patients with unilateral and bilateral PA. We observed that the serum PTH value decreased after treatment of PA with unilateral adrenalectomy or mineralocorticoid receptor antagonists. Conclusion Our findings suggest that the PTH value in PA patients might be associated with the autonomous production of aldosterone. However, there was no correlation between the PTH value and PA subtypes in our study. Additionally, our study showed that targeted treatment for PA may lead to a decrease in the serum PTH levels. Hence, the PTH value could potentially be used as an index for measuring the suitability for PA treatment.

Malignant hyperthermia in a 16-day-old infant with congenital diaphragmatic hernia: a case report.

Malignant hyperthermia (MH) is a severe hypermetabolic disorder associated with dysregulation of calcium homeostasis and is triggered by inhalational anesthetics (isoflurane, sevoflurane, desflurane) and a depolarizing muscle relaxant (succinylcholine). We report the case of a 16-day-old infant undergoing laparoscopic surgery. The patient developed hyperthermia and hypercarbia with muscle rigidity. After the diagnosis of MH, dantrolene was administered with sufficient hydration. The patient was transferred to the pediatric intensive care unit for monitoring and treatment of acute renal injury due to myoglobinuria. Subsequently, two variants of the ryanodine receptor 1 (RYR1) gene were identified in the patient as the mutation point at c.1589G > A p.Arg530His and c.1841G > T p.Arg614Leu, which are known to be associated with MH. This was a rare case of MH in a 16-day-old infant that might be related to two RYR1 mutations inherited from the parents.

Effects of Remimazolam and Propofol on Ca2+ Regulation by Ryanodine Receptor 1 with Malignant Hyperthermia Mutation.

BACKGROUND: We investigated the potential safety of remimazolam and propofol in malignant hyperthermia- (HM-) susceptible patients using ryanodine receptor 1- (RYR1-) expressing human embryonic kidney- (HEK-) 293 cells. METHODS: We compared the enhanced responsiveness of HEK-293 cells expressing wild-type RYR1 with that of mutant RYR1 to caffeine following perfusion with remimazolam or propofol. Furthermore, we investigated whether RYR1 enhanced the responsiveness of cells to remimazolam or propofol and compared the median effective concentration (EC50; i.e., the concentration required to reach half-maximal activation) using an unpaired two-tailed t-test while a P < 0.05 was considered significant. RESULTS: Remimazolam and propofol did not promote the caffeine-induced increase in intracellular Ca2+ levels in HEK-293 cells expressing mutant RYR1 even with exposure to approximately 100-fold the clinically used concentration. In wild-type RYR1, EC50 values of remimazolam following refusion vs. nonperfusion were 2.86 mM vs. 2.75 mM (P = 0.76) while for propofol perfusion vs. nonperfusion, they were 2.76 mM vs. 2.75 mM, respectively (P = 0.83). In mutant RYR1, EC50 values of remimazolam refusion vs. nonperfusion were 1.58 mM vs. 1.71 mM, respectively (P = 0.63) while for propofol perfusion vs. nonperfusion, they were 1.65 mM vs. 1.71 mM, respectively (P = 0.73). Remimazolam and propofol increased intracellular Ca2+ levels in a concentration-dependent manner, but the effect was not enhanced by RYR1. EC50 values of remimazolam with non-RYR1 vs. wild-type RYR1 were 1.00 mM vs. 0.92 mM, respectively (P = 0.91) while those of propofol were 1.09 mM vs. 1.05 mM, respectively (P = 0.84). CONCLUSIONS: The increase in intracellular Ca2+ concentration caused by remimazolam or propofol was not considered an RYR1-mediated reaction. We conclude that remimazolam and propofol can be safely used as an anesthetic in MH-susceptible patients with RYR1-mutation without causing MH and may be safely substituted for an MH-triggering anesthetic when RYR1-mediated MH occurs.

Pharmacokinetics of intraperitoneal and subcutaneous levobupivacaine in anesthetized rats.

BACKGROUND: We compared the pharmacokinetics of levobupivacaine when administered intraperitoneally, subcutaneously, and intravenously in an anesthetized rat model, to estimate the toxicity risk of a local anesthetic when absorbed from the peritoneum. METHODS: Thirty-two rats were anesthetized with sevoflurane. In Experiment 1, we administered 5.0 mg/kg of levobupivacaine intraperitoneally (IP) (n = 7), subcutaneously (SC) (n = 6), or intravenously (IV) (n = 6). In Experiment 2, we administered 2.5 mg/kg of levobupivacaine IP (n = 7) or SC (n = 6). Data are shown as median [range] of Experiment 1. RESULTS: In either of experiments, the time to reach maximum plasma concentration of levobupivacaine was shorter in the IP group than in the SC group (IP: 2 [2-5] min; SC: 5 [2-10] min; P = 0.04), and the maximum concentration of levobupivacaine did not differ between the IP and SC groups (IP: 0.45 [0.05-0.67] µg/mL; SC: 0.47 [0.21-0.62] µg/mL; P = 0.90). The area under the curve from time 0 to 120 min after levobupivacaine administration was significantly higher in the SC group than in the IP group in both experiments (IP: 0.29 [0.10-0.54] mg h/L; SC: 0.78 [0.39-0.98] mg h/L; P = 0.04). CONCLUSION: Levobupivacaine is rapidly absorbed following IP administration, but its maximum plasma concentration within 2 h following IP administration is no statistical difference as that following SC administration. On the other hand, when levobupivacaine is given subcutaneously, Tmax can exceed 1 h, so we need to be aware of local anesthetic toxicity during this period.

Retraction Note to: Functional analysis of newly identified RYR1 variants in patients susceptible to malignant hyperthermia.

The authors have retracted this article because they did not have permission to use the data in Tables 1 and 2.

Feasibility of a Novel Mobile C-Reactive Protein-Testing Device Using Gold-Linked Electrochemical Immunoassay: Clinical Performance Study.

BACKGROUND: Home-based care is one of the most promising solutions to provide sufficient medical care for several older patients in Japan. However, because of insufficient diagnostic devices, it is sometimes difficult to detect early signs of the occurrence or worsening of diseases, such as infections under home-based care settings. C-reactive protein (CRP) is highly sensitive to diagnosing infections, and its elevation can help diagnose acute infection in older patients. Therefore, a CRP-measuring device that can be used in such a specific occasion is needed for home-based care. However, aspects such as its size, weight, and procedure are still challenging with respect to the practical use of mobile devices that quantitatively measure CRP levels easily and quickly under home-based care settings. OBJECTIVE: We developed a new mobile, rapid CRP measurement device using a gold-linked electrochemical immunoassay (GLEIA) system. The aim of this study was to evaluate the feasibility of this mobile CRP-testing device. METHODS: First, we assessed the performance of bare GLEIA-based electrode chips as the foundation of the device. After embedding the bare GLEIA-based electrode chips in a special plastic case and developing the mobile CRP-testing device, we further tested the device prototype using clinical blood samples. Finally, we evaluated the intra-assay variability for precision in the same condition and inter-assay variability for reproducibility in different conditions. RESULTS: Blood samples for analysis were obtained by direct vein puncture from outpatients (N=85; females: 57/85; males: 28/85; age: 19-88 years) at Kanazawa University Hospital in Japan. For performance evaluation of bare GLEIA-based electrode chips, we used 85 clinical blood samples. There was a significant positive correlation between the electrode-predicted CRP levels and the reference CRP concentrations (R2=0.947; P<.001). The assembled device was mobile (size 45×90×2.4 mm; weight 10 g) and disposable. The minimum volume of the sample needed for measuring CRP was 1.4 µL. The estimated preanalytical time was approximately 7 minutes and 40 seconds, and analysis time was approximately 1 minute and 10 seconds. Subsequently, for performance evaluation of the mobile CRP-testing device using GLEIA-based electrode chips, we used 26 clinical blood samples and found a significant positive correlation between the mobile device-predicted CRP levels and the reference CRP concentrations (R2=0.866, P<.001). The intra-assay variabilities were 34.2%, 40.8%, and 24.5% for low, medium, and high CRP concentrations, respectively. The inter-assay variabilities were 46.5%, 38.3%, and 64.1% for low, medium, and high CRP concentrations, respectively. CONCLUSIONS: Our findings suggest that this new mobile CRP-testing device might be suitable for use in home-based care settings.

Functional analysis of newly identified RYR1 variants in patients susceptible to malignant hyperthermia.

PURPOSE: This study aimed to evaluate whether the three ryanodine receptor type 1 (RYR1) variants (p.Ser2345Thr, p.Ser2345Arg, and p.Lys3367Arg) which we identified in Japanese malignant hyperthermia (MH) patients with a clinical grading scale rank of 6 were causative for MH. METHODS: We prepared human embryonic kidney (HEK)-293 cells transfected with wild-type RYR1 or one of the RYR1 variants, along with myotubes cultured from muscle pieces. Calcium kinetics were examined by calculating the 340/380-nm ratio under various caffeine and 4-chloro-m-cresol (4CmC) concentrations with the ratiometric dye Fura-2 AM. Half-maximal effective concentration (EC50) values were calculated from dose-response curves. Statistical analysis was based on one-way analysis of variance with a Dunnett's multiple comparison test, using a P value < 0.05 as evidence of statistical significance. RESULTS: In functional analysis using HEK-293 cells, we found significant reductions in the EC50 of p.Ser2345Thr and p.Ser2345Arg in comparison with wild-type RYR1 (P < 0.001), while the EC50 of p.Lys3367Arg was not significantly different (P = 0.062 for caffeine and P > 0.999 for 4CmC). On the other hand, functional analysis using myotubes showed significant differences in the EC50 values for all variants (P < 0.001 for all comparisons). CONCLUSIONS: p.Ser2345Thr and p.Ser2345Arg appear capable of causing a calcium metabolism disorder that leads to the onset of MH, and p.Ser2345Arg can be considered as a diagnostic mutation, because it meets the European Malignant Hyperthermia Group criteria. However, patients with p.Lys3367Arg might have mutations in genes other than RYR1 that are capable of causing MH.

Assessment of postoperative nutritional status and physical function between open surgical aortic valve replacement and transcatheter aortic valve implantation in elderly patients.

Background and aims : Severe aortic stenosis (AS) has been normally treated with surgical aortic valve replacement (AVR) whereas recently, transcatheter aortic valve implantation (TAVI) has been introduced as a minimally invasive operation for patients with high surgical risk and frailty. In this study, we have evaluated postoperative physical function and nutrition intake in the patients following AVR and TAVI. Methods : This prospective observational study involved 9 patients with surgical aortic valve replacement (AVR) and 7 patients with transcatheter aortic valve implantation (TAVI). Body composition was measured one day prior surgery, postoperative day (POD) 1, POD 3, POD 5 and POD 7. Hand grip strength, calf circumference and gait speed were measured one day before surgery and on the day of discharge. Results : Skeletal muscle was significantly decreased in AVR patients at postoperative day 3 and 7, while there was no change in TAVI patients. Patients with TAVI showed higher dietary intake after surgery compared to patients with AVR, and they maintained hand grip strength and calf circumference at discharge. Conclusions : In elderly patients with AS, TAVI can improve post-operative recovery maintaining nutritional status and physical function even. J. Med. Invest. 67 : 139-144, February, 2020.

Aurora B kinase activity is regulated by SET/TAF1 on Sgo2 at the inner centromere.

The accurate regulation of phosphorylation at the kinetochore is essential for establishing chromosome bi-orientation. Phosphorylation of kinetochore proteins by the Aurora B kinase destabilizes improper kinetochore-microtubule attachments, whereas the phosphatase PP2A has a counteracting role. Imbalanced phosphoregulation leads to error-prone chromosome segregation and aneuploidy, a hallmark of cancer cells. However, little is known about the molecular events that control the balance of phosphorylation at the kinetochore. Here, we show that localization of SET/TAF1, an oncogene product, to centromeres maintains Aurora B kinase activity by inhibiting PP2A, thereby correcting erroneous kinetochore-microtubule attachment. SET localizes at the inner centromere by interacting directly with shugoshin 2, with SET levels declining at increased distances between kinetochore pairs, leading to establishment of chromosome bi-orientation. Moreover, SET overexpression induces chromosomal instability by disrupting kinetochore-microtubule attachment. Thus, our findings reveal the novel role of SET in fine-tuning the phosphorylation level at the kinetochore by balancing the activities of Aurora B and PP2A.