85 research outputs found
MERRF/MELAS overlap syndrome: A double pathogenic mutation in mitochondrial tRNA genes
No full textBackground : Myoclonic epilepsy with ragged-red fibres (MERRF) and mitochondrial encephalopathy, lactic acidosis and stroke-like episodes (MELAS) are established phenotypes of mitochondrial encephalomyopathy. The m.8356T>C transition in the mitochondrial tRNALys gene is a pathogenic mutations of MERRF. The m.3243A>G transition in the mitochondrial tRNALeu gene is detected in most MELAS patients. Although previous analyses of double mutations in mitochondrial DNA (mtDNA) were useful for discussing their nature, many unsolved questions remain. Objective : To describe the clinical and genetic features of a family with the above mtDNA double-point mutations and discuss the role of double mtDNA mutations in diverse clinical features in the family. Patients and methods : The proband was a 23-year-old woman with MERRF harbouring m.8356T>C and m.3243A>G transitions in mitochondrial tRNA genes. We assessed clinical aspects of her and those of her three relatives and performed mutation analyses on their mtDNA. Results : Phenotypes of the four patients were MERRF, MERRF/MELAS overlap syndrome and asymptomatic carrier. We hypothesise that the course of the phenotype of this family begins with MERRF and is followed by MELAS. This double mutation was heteroplasmic in blood of all four patients but with different rates in each patient, while m.8356T>C appeared homoplasmic and m.3243A>G was heteroplasmic in muscle of the two examined cases. No other mutations were detected in the total mtDNA sequence in this family. Conclusions : This is the first reported case of a double-point mutation in mtDNA, both of which were heteroplasmic and pathogenic for the established phenotypes
Local factors affecting winter habitat use of non-native rainbow trout in a boreal stream in northern Japan
No full textDespite its potential use for population control, the winter ecology of nonnative fishes is still poorly understood due to the difficulty of conducting field surveys. In this study, we investigated the winter habitat use of invasive rainbow trout Oncorhynchus mykiss at the cannel unit scale (i.e., pool, riffle). Twenty-four reaches were surveyed in late December 2013 along the Obicha River, a tributary of the Otofuke River, Tokachi River basin, Hokkaido, Japan. A total of 532 fish were captured, of which 96% were rainbow trout, whereas native salmonid was only a single southern Asian Dolly Varden Salvelinus curilus. Smaller rainbow trout (< 250 mm) used reaches with low velocity, whereas larger trout (250-520 mm) aggregated in specific reaches with deep pools with abundant cover and coarse substrate. A previous tributary-scale study in the same river system showed the importance of velocity and temperature, but not depth and substrate. Therefore, habitat selection would be scale-, as well as size-, dependent. This study provides useful information on capturing large mature adults in winter for effective control of nonnative salmonids
Successful cochlear implantation in a patient with mitochondrial hearing loss and m.625G > A transition
No full textObjective: We present a patient with mitochondrial hearing loss and a novel mitochondrial DNA transition, who underwent successful cochlear implantation. Case report: An 11-year-old girl showed epilepsy and progressive hearing loss. Despite the use of hearing aids, she gradually lost her remaining hearing ability. Laboratory data revealed elevated lactate levels, indicating mitochondrial dysfunction. Magnetic resonance imaging showed diffuse, mild brain atrophy. Cochlear implantation was performed, and the patient's hearing ability was markedly improved. Whole mitochondrial DNA genome analysis revealed a novel heteroplasmic mitochondrial 625G>A transition in the transfer RNA gene for phenylalanine. This transition was not detected in blood DNA from the patient's mother and healthy controls. Mitochondrial respiratory chain activities in muscle were predominantly decreased in complex III. Conclusion: This case indicates that cochlear implantation can be a valuable therapeutic option for patients with mitochondrial syndromic hearing loss
ANTI‐ARRHYTHMIC EFFECTS OF A NEW CALCIUM ANTAGONIST, MONOTEPIL, AJ‐2615, IN EXPERIMENTAL ARRHYTHMIC MODELS
No full text
Surface Plasmon Resonance Hydrogen Sensor based on Hetero-core Optical Fiber Structure
No full textAbstractIn this paper, we report the surface plasmon resonance (SPR) hydrogen sensor based on hetero-core optical fiber structure. This sensor consists of a multilayer stack made of a gold, a tantalum pentaoxide and a palladium (Pd) layer. It have been known that permittivity of Pd, which is a hydrogen storage metal, slightly changes with Pd hydrogenation. We experimentally obtained that SPR resonance was changed by 28nm in wavelength with ranging from 0 to 4% hydrogen concentration. In addition, it was found that Pd thickness could tune the SPR resonance wavelength. On the other hand, its SPR broad spectrum enables the proposed sensor to be modulated with intensity-basis with an LED operation at 850nm. It was presented that the proposed sensor induced a transmitted loss change of approximately 0.4dB with reaction time of 40sec. in the range of 0 – 4% hydrogen
Successful cochlear implantation in a patient with mitochondrial hearing loss and m.625G > A transition
No full text
- …
