• Journal of Microbiology
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• v.44 no.5
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• pp.492-501
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• 2006

In this study, we attempted to characterize the physiological response to oxidative stress by heat shock in Saccharomyces cerevisiae KNU5377 (KNU5377) that ferments at a temperature of $40^{\circ}C$. The KNU5377 strain evidenced a very similar growth rate at $40^{\circ}C$ as was recorded under normal conditions. Unlike the laboratory strains of S. cerevisiae, the cell viability of KNU5377 was affected slightly under 2 hours of heat stress conditions at $43^{\circ}C$. KNU5377 evidenced a time-dependent increase in hydroperoxide levels, carbonyl contents, and malondialdehyde (MDA), which increased in the expression of a variety of cell rescue proteins containing Hsp104p, Ssap, Hsp30p, Sod1p, catalase, glutathione reductase, G6PDH, thioredoxin, thioredoxin peroxidase (Tsa1p), Adhp, Aldp, trehalose and glycogen at high temperature. Pma1/2p, Hsp90p and $H^+$-ATPase expression levels were reduced as the result of exposure to heat shock. With regard to cellular fatty acid composition, levels of unsaturated fatty acids (USFAs) were increased significantly at high temperatures ($43^{\circ}C$), and this was particularly true of oleic acid (C18:1). The results of this study indicated that oxidative stress as the result of heat shock may induce a more profound stimulation of trehalose, antioxidant enzymes, and heat shock proteins, as well as an increase in the USFAs ratios. This might contribute to cellular protective functions for the maintenance of cellular homeostasis, and may also contribute to membrane fluidity.

• Journal of Microbiology
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• v.45 no.6
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• pp.541-546
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• 2007

Red algae are distributed globally, and the group contains several commercially important species. Griffithsia okiensis is one of the most extensively studied red algal species. In this study, we conducted expressed sequence tag (ESTs) analysis and synonymous codon usage analysis using cultured G. okiensis samples. A total of 1,104 cDNA clones were sequenced using a cDNA library made from samples collected from Dolsan Island, on the southern coast of Korea. The clustering analysis of these sequences allowed for the identification of 1,048 unigene clusters consisting of 36 consensus and 1,012 singleton sequences. BLASTX searches generated 532 significant hits (E-value <$10^{-4}$) and via further Gene Ontology analysis, we constructed a functional classification of 434 unigenes. Our codon usage analysis showed that unigene clusters with more than three ESTs had higher GC contents (76.5%) at the third position of the codons than the singletons. Also, the majority of the optimal codons of G. okiensis and Chondrus crispus belonging to Bangiophycidae were G-ending, whereas those of Porphyra yezoensis belonging to Florideophycidae were G-ending. An orthologous gene search for the P. yezoensis EST database resulted in the identification of 39 unigenes commonly expressed in two rhodophytes, which have putative functions for structural proteins, protein degradation, signal transduction, stress response, and physiological processes. Although experiments have been conducted on a limited scale, this study provides a material basis for the development of microarrays useful for gene expression studies, as well as useful information for the comparative genomic analysis of red algae.

• Journal of Photoscience
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• v.9 no.2
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• pp.41-43
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• 2002

In photoreceptor cells, light activates visual pigments consisting of a chromophore (retinal) and a protein moiety (opsin). Activated visual pigments trigger an enzymatic cascade, called phototransduction cascade, in which more than ten phototransduction proteins are participating. Two types of vertebrate photoreceptor cells, rods and cones, play roles in twilight and daylight vision, respectively. Cones are further classified into several subtypes based on their morphology and spectral sensitivity. Though the diversities of vertebrate photoreceptor cells are crucial for color discrimination and detection of light over a wider range of intensities, the molecular mechanism to characterize the photoreceptor types remains unclear. We investigated the amino acid sequences of about 50 vertebrate opsins, and found that these sequences can be classified into five fundamental subfamilies. Clear relationships were found between these subfamilies and their characteristic spectral sensitivities. In addition to opsins, we studied other phototransduction proteins. The amino acid sequences of phototransduction proteins can be classified into a few subfamilies. Even though their spectral sensitivity is considerably different, cones fundamentally share the phototransduction protein isoforms which are different from those found in rods. It is suggested that the difference in phototransduction proteins between rods and cones is responsible for their sensitivity to light. Isoforms and their selective expression may characterize individual photoreceptor cells, thus providing us with physiological functions such as color vision and daylight/twilight visions.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.1
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• pp.121-126
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• 2009

Korean ginseng (Panax ginseng C. A. Meyer) has been used as an important medicinal plant in the Orient for a long time. It has been claimed that ginseng has many beneficial bioactive effects on human health, such as antitumor, antistress, antiaging and enhancing immune functions. Red ginseng possibly have new ingredients converted during steaming and dry process from fresh ginseng. In this study, pharmacological efficacy and ingredient conversion of ginseng by 9 repetitive steaming and drying process were investigated measuring conversion efficiency of acidic-polysaccharide, phenolic compounds and inhibition of peroxide lipides. It was found that acidic-polysaccarides were increased by heat treatment. In addition, maltol of phenolic compounds, strong antioxidant, produced during the process of red ginseng by Maillard reaction. Acidic-polysaccarides and maltol were increased after the 1st and 3rd steaming and drying treatments, but they were decreased gradually after 5th, 7th, and 9th treatments. Antioxidant activity was increased as increasing treatment times of steaming and drying without significance. Effect of red ginseng extract on inhibition of peroxide was increased gradually until after the 7th treatment, but remarkably decreased after the 9th treatment.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.1
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• pp.174-179
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• 2009

Arterial pulse palpation is an important diagnostic method in Oriental Medicine, particularly for obtaining information about a patient's health conditions or illness, or for confirming a diagnostic conclusion based on the patient's pulsation. The pulse analyzer is both a leading Oriental Medical equipment and a promising tool with such a strong industrial ripple effect that it was selected as one of the four strategic tools for world Oriental Medical instrument market domination at a recent survey. Although various pulse analyzers had been developed, however, most of these were not widely used for clinical diagnosis, due perhaps to lack of the appliance's reliability caused by its inability to reflect the requirements of the clinicians. Thus, in this thesis, the clinical requirements for the pulse analyzer were identified and analyzed by conducting a questionnaire survey among Oriental Medicine clinicians. By looking into the basic functions of a pulse analyzer, the required measurement time, and the medical insurance fee required were determined and among others, the appliance's specific requirements were determined. Moreover, by investigating on the latest patent trend, the technical elements that are needed for the development of a next-generation pulse analyzer were identified. Through these processes, the flow of the technology that must be developed for the pulse analyzer was determined, and the direction for the development of the specific pulse analyzer hardware, sensor, and diagnostic algorithm was identified and proposed.

• Food Science and Preservation
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• v.22 no.2
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• pp.297-302
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• 2015

Calcium is one of the essential mineral for the humans due to its crucial physiological functions in the body. Calcium deficiency results in many diseases, such as osteoporosis. Therefore, calcium supplements are available as a functional food. However, most calcium supplements in the market have a limitation due to poor absorption and low bioavailability. Thus, calcium-chelated peptides for improving the absorption rate of calcium have been isolated from foods including porcine meat and bone meal (MBM), and mussel using the enzymatic hydrolysis of their protein. The hydrolysates of food were ultra-filtered in order to obtain small peptides less than 3 kDa and the Ca-binding peptides were isolated via the anion exchange chromatography. The binding activity and concentration of Ca-binding pepetides were determined. In particular, the MBM and mussel protein hydrolysates were fractionated by mono Q and Q-Sepharose, respectively. As a result, among the fractions, the fractions of MBM F2 and mussel F3 showed the highest Ca-binding activity. These results suggest that MBM and mussel protein hydrolysates can be used as calcium supplements.

• Molecules and Cells
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• v.26 no.2
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• pp.113-120
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• 2008

Laser light microscopy enables observation of various simultaneously occurring events in living cells. This capability is important for monitoring the spatiotemporal patterns of the molecular interactions underlying such events. Two-photon excited fluorescence microscopy (two-photon microscopy), a technology based on multiphoton excitation, is one of the most promising candidates for such imaging. The advantages of two-photon microscopy have spurred wider adoption of the method, especially in neurological studies. Multicolor excitation capability, one advantage of two-photon microscopy, has enabled the quantification of spatiotemporal patterns of $[Ca^{2+}]_i$ and single episodes of fusion pore openings during exocytosis. In pancreatic acinar cells, we have successfully demonstrated the existence of "sequential compound exocytosis" for the first time, a process which has subsequently been identified in a wide variety of secretory cells including exocrine, endocrine and blood cells. Our newly developed method, the two-photon extracellular polar-tracer imaging-based quantification (TEPIQ) method, can be used for determining fusion pores and the diameters of vesicles smaller than the diffraction-limited resolution. Furthermore, two-photon microscopy has the demonstrated capability of obtaining cross-sectional images from deep layers within nearly intact tissue samples over long observation times with excellent spatial resolution. Recently, we have successfully observed a neuron located deeper than 0.9 mm from the brain cortex surface in an anesthetized mouse. This microscopy also enables the monitoring of long-term changes in neural or glial cells in a living mouse. This minireview describes both the current and anticipated capabilities of two-photon microscopy, based on a discussion of previous publications and recently obtained data.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.1
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• pp.50-56
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• 2003

This research was done to make the effective prescription and cope with various senile dementia. So Sprague-Dawley rats were injected with ibotenate to make a damage on learning and memory functions. At first acquisition test and retention rest were done in the Morris water maze. And to evaluate the effects of the sample drug(TBM) on choline acetyltranferase and acetylcholine esterase, immunoreactive measurement and enzymatic activity measuring were carried out. The ibotenic acid were injected to hippocampus CA1 and CA3 area. The results were as following. TBM improved the learning ability in the acquisition test and memory function in the retention test significantly. And TBM increased the level of ChAT which is synthesizing acetylcholine in CA3 area, and at the same time it increased the level of AChE which is resolving acetylcholine. These results show that T8M improved the cholinergic catabolism and anabolism, and the increment of metabolic activity of cholinergic system. In other words, it contributes to the recovery of damaged learning and memory function by ibotenic acid. So it can be concluded that TBM will be helpful to cholinergic brain damage induced by primary or senile reduction of acetylcholine secretive activity.

• The Korean Journal of Physiology
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• v.27 no.1
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• pp.107-114
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• 1993

Most of voltage operated $Ca^{2+}$ channels can be divided into three types (T-, N-, and L-type), according to the electrical and pharmacological properties. Their distribution is closely related to cell specific functions. Properties of the voltage activated $Ca^{2+}$ current in mouse eggs were examined to classify channel types and to deduce the function by using whole cell voltage clamp technique. $Ca^{2+}$ currents appeared below -40 mV and reached a maximum at -15 mV (half maximum was -31 mV), then decayed rapidly (inactivation time constant ${\tau}=28.2{\pm}9.59$ ms at -10 mV within 50 ms after the onset of step depolarization. Activation and inactivation of the $Ca^{2+}$ channel was steeply dependent on voltage, in a relatively low range of $-70\;mV{\sim}-10 mV,$ half maximum of activation was -31 mV and that of inactivation was -39 mV, respectively. This current was not decreased significantly by nifedipine, a specific dihydropyridine $Ca^{2+}$ channel blocker in the range of $1\;{\mu}M\;to\;100{\mu}M.$ The inhibitory effect of $Ni^{2+}\;on\;Ca^{2+}$ current was greater than that of $Cd^{2+}.$ The conductance of $Ba^{2+}$ through the channel was equal to or lower than that of $Ca^{2+}$ These results implied that $Ca^{2+}$ current activated at a lower voltage in the mouse egg is carried via a $Ca^{2+}$ channel with similar properties that of the T-type channel.

• The Korean Journal of Physiology
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• v.1 no.1
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• pp.83-90
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• 1967

In order to evaluate the accuracy of the measurement of maximal oxygen intake (MOI), the MOI in seven subjects was determined 3 to 4 times in each individual. Following a 10 minute warm-up on treadmill (4.3 km/hr with 9 degree grade), the subject was asked to run at a speed of 8.73 km/hr on treadmill for a period of 3 minutes at a given grade which was elevated in a step-wise manner from zero to the level of exhaustion. Following a 3 minute run, the subject was allowed to rest for a period of 3 to 5 minutes. During each period of running, several cardio-pulmonary functions were determined and the range of variability for each measurement was computed. The oxygen consumption during the maximal work load was taken as the MOI. The results may be summarized as follows: (1) The minute volume, the oxygen consumption and the heart rate increased linearly until the grade was elevated to 9 degree above which these values were leveled off. (2) The minute volume and the heart rate during maximal exorcise were $87.4{\pm}8.10\;1/min\;and\;187{\pm}3.7$ per minute, respectively. (3) The maximal oxygen intake which corresponds to the oxygen consumption during maximal exercise was averaged to 3.04 1/min. (4) The coefficient of variance for the maximal oxygen intake was 6.32% while the corresponding values for the minute volume and the heart rate during maximal exercise were 5.22 and 2. 14%, respectively.