• PNF and Movement
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• v.16 no.2
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• pp.259-266
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• 2018

Purpose: This study aimed to compare balance ability according to the immersion level of virtual reality-based training for the balance enhancement of the elderly. Methods: This study included 48 elderly people aged 65 years and older (male 16, female 32). According to the immersion level of applied virtual reality training, 16, 17, and 15 persons were randomly assigned to full immersion, semi-immersion, and control groups. The subjects who were assigned to the full immersion group and semi-immersion group received virtual reality training for 6 weeks at 20 min at a time, 3 times per week. The control group received no intervention. Balance ability was evaluated by measuring the stability limit and the tandem walking test before and after the intervention. Results: Results showed significant differences among the three groups in the limit of stability of all directions and the tandem walking test after the intervention. The results of the limit of stability showed a significantly higher value in the full-immersion group than in the control group, and the results of the tandem walking test showed a significantly lower value in the full-immersion and semi-immersion groups than in the control group. Conclusion: The results indicate that the head-mounted display equipment for applying full-immersion virtual training is the most effective in enhancing the balance ability of the elderly.

• The Korean Journal of Physiology
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• v.8 no.2
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• pp.67-74
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• 1974

The object of this research is aimed to determine the activity of adenyl cyclase in both skeletal muscle sarcolemma and fat cell ghost of epididymal adipose tissue isolated from rats exposed to cold for various length of time in an attempt to evaluate whether the tissue sensitivity to catecholamine is increased when rats are exposed to cold for long periods of time Methods: a)Animals: Albino rats ranging in weight from 150 to 200 gm were used throughout this study. For experimental purposes, the rats are divided into two groups: experimental animals were place4 in a cold room at $4^{\circ}C$, controls being kept at $25^{\circ}C$. At the end of 2, 4, 6, 12, and 16 weeks. exposure to cold the rats were used to measure the adenyl cyclase activity. b) Isolation of plasma membrane from skeletal muscle and adipose tissue: The Plasma membrane of skeletal muscle from hind limbs of rats are prepared by the method employed by Rosenthal et at. and fat cell ghost of epididymal adipose tissue of rats by the method employed by Rodbell. c) Adenyl cyclase assay: Adenyl cyclase activity were measured by the method employed by Marinetti et al. Briefly, plasma membrane was incubated with $3^H-ATP$, various amount of noradrenaline and other incubation mixture at $37^{\circ}C$ for 20 minutes. After stopping the enzyme reaction by immersion in boiling water, carrier 3',5'-AMP was added to the system as a marker and $100\;{\mu}1$ aliquots of incubation mixture were pipetted on $20{\time}20$ Whatman No. 3 MM filter paper for one dimensional chromatography. The cyclic AMP spots were cut off and placed in counting vials containing 10ml of Bray's scintillation cocktail. Radioactivity was determined with a Packard Tri-Carb liquid scintillation counter. The enzyme activity is expressed as nanomoles of cyclic AMP produced per mg of membrane per hour. Result: 1. Average adenyl cyclase activity in the plasma membrane of skeletal muscle before and after noradrenaline administration was significantly higher in the cold-exposed rats as compared to the control. Continuous exposure to cold Produced an increased adenyl cyclase activity before and after noradrenaline administration. Adenyl cyclase activity reached peak levels at the 6 weeks exposure to told and level of adenyl cyclase activity remained high. Noradrenaline administration to the incubation medium induced a significant increase in adenyl cyclase activity and the degree of stimulation were proportional to the hormonal concentration But the rate of inclement in adenyl cyclase activity by noradreasline was the same in both groups. 2. Adenyl cyclase activity in fat cell ghost between cold exposed and control rats showed no significant differences before and after noradreualine administration. In summary, it can be concluded that cold adaptation give rise an increased activity of adenyl cyclase in plasma membrane of skeletal muscle in rats.

• Korean Journal of Ichthyology
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• v.23 no.1
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• pp.10-20
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• 2011

Genetic determinant for metallothionein (MT), a cysteine-rich protein playing essential roles in metal detoxification and homeostasis, was characterized in the Korean bitterling (Acheilognathus signifer, Cyprinidae), an endemic fish species. The full-length A. signifer MT (AsMT) cDNA (551 bp) is composed of a single open-reading frame (ORF) to encode a polypeptide of 60 amino acids containing 20 cysteine residues whose positions are conserved in most cypriniform MTs. At the genomic level, the AsMT (2,593 bp spanning the 5'-flanking region to the 3'-untranslated region) represented a conserved tripartite (three exons interrupted by two introns) structure with AT-rich introns. The upstream regulatory region (-1,914 bp from the ATG initiation codon) of AsMT displayed various sites and motifs for transcription factors involved in the metal-mediated regulation and stress/immune responses. The AsMT transcript was ubiquitously detected in various organs with variable expression levels, where the ovary and intestine showed the highest expression, while the heart and skeletal muscle represented the lowest level. During an exposure to copper (immersion in $0.5\;{\mu}M$ Cu for 48 h), the levels of AsMT transcripts were significantly elevated in the liver (more than 3.5-fold), moderately in the gill, kidney, and spleen (ranging from 1.5- to 2.5-fold), and barely in the brain and intestine. Results of this study could form a useful basis to explore the metal-related stress physiology of this endangered fish species.