47 research outputs found
Development and Performance of the Engineering Model of ARICA-2
We present the status of the engineering model (EM) of 2U Cubesat, AGU Remote Innovative Cubesat Alert system-2 (ARICA-2). The main goal of ARICA-2 is to demonstrate the real-time alert system of transient astronomical sources, such as gamma-ray bursts (GRBs), using commercial satellite network services such as Iridium and Globalstar. In parallel, we have a dedicated amateur mission to provide a store and forward capability for communication among amateurs. The GRB alert and the housekeeping data are also broadcast through the amateur CW transmitter. ARICA-2 was selected as one of the JAXA Innovative Satellite Technology Demonstration-4 projects in 2022 and is scheduled to be launched in the Japanese fiscal year 2025. The communication component of ARICA-2 has two commercial satellite network devices: Inmarsat\u27s SBD9603N, Globalstar\u27s STX-3, and the UHF transmitter using 435 MHz amateur frequency. The onboard computer is Sony\u27s Spresense, low-power, and six-core microcontroller board. Thanks to its multi-core processor, Spresense can run tasks in parallel by processing in individual cores, which reduces the risk of a single failure. The gamma-ray detector comprises two layers of scintillator crystals, Csl(TI) and EJ-270. The scintillation lights of each crystal are read out by eight chips of Hamamatsu\u27s MPPC S14160-6050HS. The attitude control component consists of three-axis magnetic torques, a gyro sensor, a magnetic sensor, and infrared cameras. The infrared cameras work as the Sun\u27s and the Earth\u27s sensors. The EPS, battery, solar panels, and a 2U structure are space-qualified components of ACC-Clyde Space Inc. The development of the engineering model (EM) started in August 2023. We complete the manufacture of most of the components in February 2024. And then, the integration of the EM finished on May 2024. We report the development and various test results of the EM of ARICA-2
Changes in lipoprotein lipase and endothelial lipase mass in familial hypercholesterolemia during three-drug lipid-lowering combination therapy.
Background: This study was performed to compare the effects of three different lipid-lowering therapies (statins, ezetimibe, and colestimide) on lipoprotein lipase and endothelial lipase masses in pre-heparin plasma (pre-heparin LPL and EL mass, respectively) from patients with familial hypercholesterolemia (FH). FH is usually treated by coadministration of these three drugs. Methods: The pre-heparin LPL and EL masses were measured in fresh frozen plasma drawn and stored at various time points during coadministration of the three drugs from patients with heterozygous FH harboring a single mutation in the LDL receptor (n = 16, mean age 63 years). The patients were randomly divided into two groups based on the timing when ezetimibe was added. Results: Plasma LPL mass concentration was significantly reduced by rosuvastatin at 20 mg/day (median = 87.4 [IQR: 71.4-124.7] to 67.5 [IQR: 62.1-114.3] ng/ml, P < 0.05). In contrast, ezetimibe at 10 mg/day as well as colestimide at 3.62 g/day did not alter its level substantially (median = 67.5 [IQR: 62.1-114.3] to 70.2 [IQR: 58.3-106.2], and to 74.9 [IQR: 55.6-101.3] ng/ml, respectively) in the group starting with rosuvastatin followed by the addition of ezetimibe and colestimide. On the other hand, the magnitude in LPL mass reduction was lower in the group starting with ezetimibe at 10 mg/day before reaching the maximum dose of 20 mg/day of rosuvastatin. Plasma EL mass concentration was significantly increased by rosuvastatin at 20 mg/day (median = 278.8 [IQR: 186.7-288.7] to 297.0 [IQR: 266.2-300.2] ng/ml, P < 0.05), whereas other drugs did not significantly alter its level. Conclusion: The effects on changes of LPL and EL mass differed depending on the lipid-lowering therapy, which may impact the prevention of atherosclerosis differently. © 2016 Tada et al
A novel method for determining functional LDL receptor activity in familial hypercholesterolemia: Application of the CD3/CD28 assay in lymphocytes
金沢大学附属病院循環器内科Background: The objective of this study was to develop a new and simple method for measuring low-density lipoprotein receptor (LDLR) activity using peripheral lymphocytes enabling us to clinically diagnose familial hypercholesterolemia (FH) and ascertain the involved mutations (such as K790X mutation), that might not be clearly detected in the conventional method. Methods: Our method comprised the following 2 features: first, we used anti-CD3/CD28 beads to stimulate T-lymphocytes to obtain a uniform fraction of lymphocytes and maximum up-regulation of LDLR. Second, we excluded the possibility of overestimation of lymphocyte signals bound only to its surface, by adding heparin to the cultured lymphocytes used for the LDLR assay. Results: Based on the genetic mutation, the FH subjects were divided into 2 groups, K790X, (n = 20) and P664L, (n = 5), and their LDLR activities was measured by this method, which was found to be 55.3 ± 8.9% and 63.9 ± 13.8%, respectively, of that of the control group (n = 15). In comparison, the LDLR activity was 86.1 ± 11.6% (K790X) and 73.3 ± 6.3% (P664L) of that of the control group when measured by the conventional method, indicating that impairment of LDLR function in FH K790X subjects was much more clearly differentiated with our method than with the conventional method (paired t-test, p < 0.0001). The levels of LDLR expression also showed similar tendencies, that is, 89.4 ± 13.2% (K790X) and 76.9 ± 17.4% (P664L) of that of the control group when measured by the conventional method, and 78.1 ± 9.7% (K790X) and 70.3 ± 26.5% (P664L) when measured by our new method. In addition, we confirmed that there was little influence of statin treatment on LDLR activity among the study subjects when our method was used. Conclusion: These results demonstrate that our new method is applicable for measuring LDLR activity, even in subjects with an internally defective allele, and that T-lymphocytes of the FH K790X mutation possess characteristics of that allele. © 2008 Elsevier B.V. All rights reserved
Molecular genetic epidemiology of homozygous familial hypercholesterolemia in the Hokuriku district of Japan
金沢大学医学系研究科Aim: Familial hypercholesterolemia (FH) is caused by mutations of FH genes, i.e. LDL-receptor (LDLR), PCSK9 and apolipoprotein B (ApoB) gene. We evaluated the usefulness of DNA analysis for the diagnosis of homozygous FH (homo-FH), and studied the frequency of FH in the Hokuriku district of Japan. Methods: Twenty-five homo-FH patients were recruited. LDLR mutations were identified using the Invader assay method. Mutations in PCSK9 were detected by PCR-SSCP followed by direct sequence analysis. Results: We confirmed 15 true homozygotes and 10 compound heterozygotes for LDLR mutations. Three types of double heterozygotes for LDLR and PCSK9 were found. No FH patients due to ApoB mutations were found. The incidences of homo-FH and hetero-FH in the Hokuriku district were 1/171,167 and 1/208, respectively. Conclusions: Our observations underlined the value of FH gene analysis in diagnosing homo-FH and confirmed extraordinarily high frequency of FH in the Hokuriku district of Japan. © 2010 Elsevier Ireland Ltd
Assessment of Coronary atherosclerosis in patients with familial hypercholesterolemia by coronary computed tomography angiography
The aims of this study were (1) to determine whether the accumulation of coronary plaque burden assessed with coronary computed tomography angiography (CCTA) can predict future events and (2) to estimate the onset and progression of coronary atherosclerosis in patients with familial hypercholesterolemia (FH). Consecutive 101 Japanese patients with heterozygous FH (men= 52, mean age 56 ± 16years, mean low-density lipoprotein cholesterol 264 ± 58mg/dl) who underwent 64-detector row CCTA without known coronary artery disease were retrospectively evaluated by assigning a score (0 to 5) to each of 17 coronary artery segments according to the Society of Cardiovascular Computed Tomography guidelines. Those scores were summed and subsequently natural log transformed. The periods to major adverse cardiac events (MACE) were estimated using multivariable Cox proportional hazards models. During the follow-up period (median 941days), 21 MACE had occurred. Receiver operating characteristic curve analyses identified a plaque burden score of 3.35 (raw score 28.5) as the optimal cutoff for predicting a worse prognosis. Multivariate Coxregression analysis identified the presence of a plaque score ≥3.35 as a significant independent predictor of MACE (hazard ratio= 3.65; 95% confidence interval 1.32 to 25.84, p<0.05). The regression equations were Y= 0.68. X- 15.6 (r= 0.54, p <0.05) in male and Y= 0.74. X- 24.8 (r= 0.69, p <0.05) in female patients with heterozygous FH. In conclusion, coronary plaque burden identified in a noninvasive, quantitative manner was significantly associated with future coronary events in Japanese patients with heterozygous FH and that coronary atherosclerosis may start to develop, on average, at age 23 and 34years in male and female patients with heterozygous FH, respectively
Novel mutations of cholesteryl ester transfer protein (CETP) gene in Japanese hyperalphalipoproteinemic subjects
Thesis of Ohtani, Rumiko / 大谷 留珠子 博士学位論文(金沢大学 / 大学院医薬保健学総合研究科)Background: The half of hyperalphalipoproteinemia (HALP) in Japan is caused by CETP gene mutations. Other than two prevalent mutations (D442G and Intron 14 splicing donor site +. 1G>A), some rare CETP mutations are found in Japanese HALP subjects. Methods: CETP gene analysis of genomic DNA from subjects was performed by restriction fragment length polymorphism (RFLP) and sequencing analysis. Mutations which were suspected to cause a splicing defect or a protein secretion defect were investigated in COS-1 cells transfected with a CETP minigene construct or a cDNA expression vector. Results: Each of three subjects was identified as a carrier of CETP gene mutation of a compound heterozygote of c.653_654delGGinsAAAC and Intron 14 splicing donor site +. 1G>A, a heterozygote of c.658G>A or a homozygote of L261R. The c.658G>A mutation was located at the last nucleotide of exon 7, and it was confirmed to cause splicing abnormality revealed by the CETP minigene analysis. The L261R CETP was not secreted to conditioned media of the cells. Conclusions: Three novel CETP gene mutations are responsible for HALP by CETP deficiency. It is predicted that there are more rare CETP gene mutations in Japanese, and these multiple rare mutations alone or a combination with each of prevalent mutations is responsible for mild-to-moderate or marked HALP, respectively. © 2011 Elsevier B.V
Comparison of effects of bezafibrate and fenofibrate on circulating proprotein convertase subtilisin/kexin type 9 and adipocytokine levels in dyslipidemic subjects with impaired glucose tolerance or type 2 diabetes mellitus: Results from a crossover study
金沢大学医学系研究科Background: Bezafibrate and fenofibrate show different binding properties against peroxisome proliferator-activated receptor subtypes, which could cause different clinical effects on circulating proprotein convertase subtilisin/kexin type 9 (PCSK9) levels and on various metabolic markers. Methods: An open, randomized, four-phased crossover study using 400 mg of bezafibrate or 200 mg of fenofibrate was performed. Study subjects were 14 dyslipidemia with impaired glucose tolerance or type 2 diabetes mellitus (61 ± 16 years, body mass index (BMI) 26 ± 3 kg/m2, total cholesterol (TC) 219 ± 53 mg/dL, triglyceride (TG) 183 ± 83 mg/dL, high-density lipoprotein-cholesterol (HDL-C) 46 ± 8 mg/dL, fasting plasma glucose 133 ± 31 mg/dL and HbA1c 6.2 ± 0.8%). Subjects were given either bezafibrate or fenofibrate for 8 weeks, discontinued for 4 weeks and then switched to the other fibrate for 8 weeks. Circulating PCSK9 levels and other metabolic parameters, including adiponectin, leptin and urine 8-hydroxy-2′-deoxyguanosine (8-OHdG) were measured at 0, 8, 12 and 20 weeks. Results: Plasma PCSK9 concentrations were significantly increased (+39.7% for bezafibrate and +66.8% for fenofibrate, p < 0.001) in all patients except for one subject when treated with bezafibrate. Both bezafibrate and fenofibrate caused reductions in TG (-38.3%, p < 0.001 vs. -32.9%, p < 0.01) and increases in HDL-C (+18.0%, p < 0.001 vs. +11.7%, p < 0.001). Fenofibrate significantly reduced serum cholesterol levels (TC, -11.2%, p < 0.01; non-HDL-C, -17.3%, p < 0.01; apolipoprotein B, -15.1%, p < 0.01), whereas bezafibrate significantly improved glucose tolerance (insulin, -17.0%, p < 0.05) and metabolic markers (γ-GTP, -38.9%, p < 0.01; adiponectin, +15.4%, p < 0.05; urine 8-OHdG/Cre, -9.5%, p < 0.05). Conclusion: Both bezafibrate and fenofibrate increased plasma PCSK9 concentrations. The addition of a PCSK9 inhibitor to each fibrate therapy may achieve beneficial cholesterol lowering along with desirable effects of respective fibrates. © 2011 Elsevier Ireland Ltd. All rights reserved
Exome Sequencing in Suspected Monogenic Dyslipidemias
Abstract
BACKGROUND:
-Exome sequencing is a promising tool for gene mapping in Mendelian disorders. We utilized this technique in an attempt to identify novel genes underlying monogenic dyslipidemias.
METHODS AND RESULTS:
-We performed exome sequencing on 213 selected family members from 41 kindreds with suspected Mendelian inheritance of extreme levels of low-density lipoprotein (LDL) cholesterol (after candidate gene sequencing excluded known genetic causes for high LDL cholesterol families) or high-density lipoprotein (HDL) cholesterol. We used standard analytic approaches to identify candidate variants and also assigned a polygenic score to each individual in order to account for their burden of common genetic variants known to influence lipid levels. In nine families, we identified likely pathogenic variants in known lipid genes (ABCA1, APOB, APOE, LDLR, LIPA, and PCSK9); however, we were unable to identify obvious genetic etiologies in the remaining 32 families despite follow-up analyses. We identified three factors that limited novel gene discovery: (1) imperfect sequencing coverage across the exome hid potentially causal variants; (2) large numbers of shared rare alleles within families obfuscated causal variant identification; and (3) individuals from 15% of families carried a significant burden of common lipid-related alleles, suggesting complex inheritance can masquerade as monogenic disease.
CONCLUSIONS:
-We identified the genetic basis of disease in nine of 41 families; however, none of these represented novel gene discoveries. Our results highlight the promise and limitations of exome sequencing as a discovery technique in suspected monogenic dyslipidemias. Considering the confounders identified may inform the design of future exome sequencing studies
Marked transient hypercholesterolemia caused by low-dose mitotane as adjuvant chemotherapy for adrenocortical carcinoma
金沢大学医薬保健研究域医学系We herein report a case of marked transient hypercholesterolemia in a man receiving low-dose mitotane as adjuvant chemotherapy for adrenocortical carcinoma.A 58-year-old man without any clinical symptoms or history of hypercholesterolemia was admitted to our hospital to treat an adrenocortical carcinoma detected on general screening using computed tomography. He reported no chest symptom and did not exhibit any established risk factors for coronary artery disease, such as diabetes, obesity, hypertension or relevant family history, with the exception of current smoking, on admission. A stress electrocardiogram showed negative findings. The left adrenal tumor as well as left kidney, spleen and distal portion of the pancreas were subsequently resected using radical surgery. The histopathological findings confirmed the preoperative diagnosis of adrenocortical carcinoma. After the operation, treatment with low-dose mitotane (1g/day) was introduced as adjuvant chemotherapy. Interestingly, the patient developed marked hyper-LDL cholesterolemia at a level equivalent to that of familial hypercholesterolemia (LDL cholesterol level ~ 300 mg/ dL) following the introduction of mitotane, without evidence of primary or secondary hypercholesterolemia due to other causes. A coronary angiogram performed to assess the new-onset angina revealed three-vessel disease, which was later revascularized via percutaneous coronary intervention eight months after the start of mitotane therapy. The cholesterol level normalized with the suspension of mitotane. This case suggests that mitotane can cause severe hypercholesterolemia, potentially resulting in coronary atherosclerosis. © 2014, Japan Atherosclerosis Society. All rights reserved.出版者照会後に全文公