• Applied Biological Chemistry
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• v.47 no.4
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• pp.390-395
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• 2004

In order to characterize ion channels present in tomato roots, microsomes were incorporated into an artificial lipid bilayer arranged for electrophysiological analysis. Of the five different ion channels that could be found, a channel of 450 pS conductance was found most frequently. This channel displayed subconductance states of 450, 257 and 105 pS. All subconductance states showed linear current-voltage relationships. At positive holding potentials, high frequency of transient channel openings was observed; however, at negative potentials, the open times were long and open probability high. Po was 0.83 at -40 mV. When an additional 50 mM $K^+\;or\;Na^+$ was added to the cis side of bilayer, the reversal potentials shifted in the negative direction to near -10 mV. Thus, the 450 pS cation channel selects poorly between $K^+\;and\;Na^+$. In the presence of $100\;{\mu}M$ metal ions, the channel activity was severely inhibited by $La^{3+},\;Ba^{2+},\;and\;Zn^{2+}$, and Po was decreased to 0.2 or even less. However, $Al^{3+}\;and\;Cd^{2+}$ decreased the activity by only 20%. Interestingly, each metal ion showed different kinetics of channel inhibition. While $500\;{\mu}M\;La^{3+}$ inhibited the activities of all subconductance state, 1 mM $Zn^{2+}$ inhibited all except the 105 pS state. $Cd^{2+}$ changed the gating of the channel from a long-opening state to brief transient openings even at negative holding potentials. These data represent that the metal ions may have different binding sites on the channel protein and could be useful modulators and probes to investigate structural characteristics as well as the functional roles of the 450 pS channel on the root physiology.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.5
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• pp.394-406
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• 1991

It was proved that cold tolerance of rice plants at the young microspore stage was affected by water temperature and nitrogen application from the spikelet differentiation stage to the young microspore stage, and this mechanism could be explained in the point of view of pollen developmental physiology. The cold tolerance of rice plants at the young microspore stage was severely affected by water temperature (Previous water temperature) and nitrogen application(Previous nitrogen application) from the spikelet differentiation stage to the spikelet differentiation stage. Although the duration is only 10 days or so from the spikelet differentiation stage to the young microspore stage, these days are very important period to confirm the cold tolerance of rice plants at the young microspore stage. The higher previous water temperature up to $25^{\circ}C$ and the deeper previous water depth up to 10cm caused the more cold tolerance of rice plants. Water irrigation of 10cm before the cretical stage showed lower cool injury than that of water irrigation of 20cm during the critical stage. The preventive effect of cool injury by combined treatment of the deep water irrigation before and during the critical stage was not additive but synergistic. The cold tolerance of rice plants grown in previous heavy nitrogen level was rapidly decreased when nitrogen content of leaf blade at the young microspore stage was excessive over the critical nitrogen level. Nitrogen content of leaf blade at the changing point of cold tolerance was estimated as about 3.5% for Japonica cultivars and about 2.5% for Indica x Japonica cultuvars. It is considered that these critical nitrogen contents of leaf blade can be used as a index of the safe critical nitrogen level for the preventive practices to cool injury. It was summarized that increase of engorged pollens per anther by high previous water temperature resulted from the increase of number of differentiated microspores per anther, otherwise, the increase of engorged pollens by the decrease of previous nitrogen level was caused by the decrease of the number of aborted microspores per anther.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.6
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• pp.369-377
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• 2005

Precise application of topdressing nitrogen (N) fertilizer is indispensible for securing high yield and good quality of rice and minimizing N losses to the environment as well. For precise N management, growth and nitrogen nutrition status (NNS) should be diagnosed rapidly and accurately. The objective of the study was to evaluate the applicability of vegetation index (VI) calculated from hyperspectral canopy reflectance measurement and SPAD reading to nondestructive in situ diagnosis of growth and NNS of rice. Canopy reflectance, SPAD read­ing, growth parameters, and NNS characteristics were measured from various N treatments to evaluate the relationships among them for two cropping seasons from 2001 to 2002. The correlation coefficient of VIs with variables of growth and NNS increased positively as rice canopy became more closed. Regardless of growth stages, VIs had significantly high correlations with LAI, shoot dry weight (DW), shoot N content and nitrogen nutrition index (NNI). Those correlation coefficients increased steadily before heading stage as rice grew up. However, tiller number and leaf N concentration showed significantly high correlations with VIs only at and after panicle initiation stage (PIS). Among the VIs, RVIgreen had significantly higher correlation with the measured parameters than the other VIs: it showed correlation coefficients greater than 0.8 with leaf and shoot N concentration and DW, and much higher coefficients greater than 0.9 with LAI, shoot N content, and NNI. At LAI of below 2.5, VIs had non-significant or low correlations with the growth and NNS indicators due to the background effects. SPAD reading had significantly high correlation with leaf N concentration and NNI at each growth stage. In addition, it had significant correlations with variables of growth and NNS at PIS and booting stage, particularly, at booting stage. Though SPAD reading had a significantly high correlation value at a given growth stage in each year, it showed very weak relationship with variables of growth and NNS when pooled across growth stages and years. In conclusion, RVIgreen was found to be the most reliable VI to estimate the growth and NNS of rice around at PIS, but SPAD reading had much limitations.

• Development and Reproduction
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• v.11 no.3
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• pp.187-193
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• 2007

Ethane 1,2-dimethane sulfonate(EDS), a Leydig cell specific toxicant, has been widely used to create the reversible testosterone withdrawal rat model. Though the maintenance of epididymal structure and function is highly dependent on the testosterone secreted from testis, its derivatives, dihydroxytestosterone(DHT) and estrogen, might have crucial roles. The aim of present study was to monitor the expression patterns of sex steroid receptors, cytochrome P450 aromatase(P450arom) and $5{\alpha}$-reductase in the rat epididymis up to 7 weeks after EDS injection. Adult male rats($350{\sim}400g$) were injected with a single does of EDS(75 mg/kg i.p.) and sacrificed on weeks 0, 1, 2, 3, 4, 5, 6 and 7. The transcriptional activities of the target genes were evaluated by semi-quantitative RT-PCRs. The transcript level of estrogen receptor alpha($ER{\alpha}$) in EDS group was significantly higher than control level on week 1(P<0.01). After week 2, there was no significant difference in $ER{\alpha}$ levels between EDS group and control. The transcript level of estrogen receptor beta($ER{\beta}$) in EDS group was significantly higher than control level on week 1(P<0.05), lowered on weeks 2 and 3(P<0.05 and P<0.01, respectively), fluctuated during weeks 4 and 6, and elevated on week 7(P<0.05). The androgen receptor (AR) message levels increased significantly week 2(P<0.01), then returned to control level on week 3. In contrast, expression of cytochrome P450 aromatase(P450arom) decreased sharply during weeks $1{\sim}3$(P<0.01 on weeks 1 and 2; P<0.05 on week 3), then went back to control level on week 4. The mRNA level of $5{\alpha}$-reductase type 2($5{\alpha}$-RT2) increased significantly on week 4(P<0.01), then returned to control level. The present study indicated that EDS administration could induce reversible alterations in the transcriptional activities of sex steroid hormone receptors and androgenconverting enzymes in rat epididymis. EDS injection model will be useful to clarify the regulation mechanism of mammalian epididymal physiology.

• Journal of Dairy Science and Biotechnology
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• v.33 no.2
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• pp.119-127
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• 2015

To date, detection of microbial populations in dairy products has been performed using culture media, which is a time-consuming and laborious method. The recently developed chromogenic media could be more rapid and specific than classical culture media. However, the newly developed molecular-based technology can detect microbial populations with greater rapidity and sensitivity than the classical method involving culture media and chromogenic media. This molecular-based technology could provide various options for monitoring the characterization of different states of bacteria and cells. Thus, it could help upgrade the processing system of the dairy industry so as to maintain the safety and quality of dairy foods. Among the various newly developed molecular-based technologies, flow cytometry can potentially be used for monitoring microbiological populations in the dairy industry if official international standards are available for this purpose. When omics technology would have biomarker identification, it could be regarded as the rapid and sensitive analytical methods. Methods based on PCR, which has become a basic technique in microbiological research, can be developed and validated as alternative methods for quantification of dairy microorganisms. This review discusses methods for monitoring microbiological populations in dairy foods and the limitations of these studies, as well as the need for further research on such methods in the dairy industry.

• Journal of Dairy Science and Biotechnology
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• v.33 no.2
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• pp.129-137
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• 2015

Diabetes mellitus type 2 is a metabolic disorder that is characterized by hyperglycemia (high blood sugar level) in the context of insulin resistance and relative lack of insulin. Recently, much scientific evidence has shown that the risk of diabetes mellitus type 2 could be reduced by dairy intake. A significantly strong relationship has been noted between this disease and dairy intake. In particular, from the different types of fat in dairy foods that were reported to have a beneficial impact, low-fat dairy foods have been found to have the best effect with respect to reducing the risk of diabetes mellitus type 2. Therefore, the role of specific components of dairy foods, such as calcium, vitamin D, dairy fat, and trans-palmitoleic acid, which could be responsible for this effect and for the positive effect of dairy foods in obesity and metabolic syndrome, needs to be identified. There is a strong and relatively consistent body of accumulating evidence indicating that dairy foods may significantly reduce the risk of diabetes mellitus type 2, likely in a dose-response manner. Dairy recommendations should be an essential part of public health guidance, and identifying strategies to increase dairy food consumption to optimal levels is of utmost importance. Hence, this review summarizes various positive effects of dairy foods with respect to reducing the risk of diabetes mellitus type 2, based on available evidence, and discusses the need for further research on preventing or decreasing the risk of diabetes mellitus type 2.

• Applied Microscopy
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• v.18 no.1
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• pp.1-20
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• 1988

There's been arguments on the different morphological status between the nucleus accumbens septi and nucleus fundus striati of ventral striatum. Authors carried out the comparative study on the neuronal cell types of these nuclei, in the chick and the rat. Results are summarized as follows: In the nucleus accumbens septi of the chick, there found 3 main cell types. Type I cells are oval or spindle-shaped. They are the most abundant cell types, comprising more than 80% of neurons. The pale nucleus is usually indented. The cytoplasm is also pale and contains small amount of mitochondria, rough r-ER and Golgi complexes. This cell has a few symmetric synapses on the cell membrane. Type II cells are pale large cells. They are polygonal or irregularly-shaped. They contain pale spherical nucleus, and the pale cytoplasm with relatively large amount of mitochondria, free ribosomes and well-developed Golgi complexes. Some axo-somatic synapes are found on the cell. Type III cells are oval or spherical-shaped. The nucleus is relatively pale and large, In the dense cytoplasm, well developed. r-ER formed typical Nissl's body, and there found many mitochondria, ribosomes and lysosomes. In the chick fundus striati nucleus, there also found 3 main cell types. Type I cells are small and spindle-shaped. This type is the most abundant one and constitutes more the 80% of the neurons. Morphological features other than it's shape, is generally similar with that of Type I cell in the nucleus accumbens. Type II cells are irregularly shaped large cells. Dense cytoplasm contains large amount of cell organelles. Some axo-somatic synapses are found. Type III cells are small dense cells. This oval cell contains the oval nucleus, and the plentiful cytoplasm with well developed r-ER, ribosomes and mitochondria. In the nucleus accumbens septi of the rat, there found 4 main cell types. Type I cells are small, oval or spherical cells, comprising more than 90% of all the neurons. Spherical nucleus shows typical chromatin rim along the nuclear membrane. Dense cytoplasm contains many ribosomes and mitochondria. Type II cells are large oval cells. The eccentric nucleus is deeply invaginated. Pale cytoplasm contains large amount of ribosomes, Golgi complexes, mitochondria, and dense bodies. Type III cells are pale, large, oval cells. They contain moderate amount of ribosomes and mitochondria, and some scattered stacks of r-ER. Type IV cells are small pale cells. Small oval nucleus is indented and shows chromatin rim. Only small amount of ribosomes and mitochondria can be found. In the nucleus fundus striati of the rat, there also found 4 main cell types. Type I cells are spherical or oval cells, comprising more than 90% of the neurons. The chromatin rim of the spherical nucleus is not so prominent as compared to the rim of type I cell in the nucleus accumbens septi. The cytoplasm contains moderate amount of mitochondria, ribosomes and some scattered r-ER. A few axo-somatic synapses were found. Type II cells are small round or polygonal cells. Golgi complexes are especially well-developed in this cell type. The cytoplasm also contains moderate amount of mitochondria, ribosomes, and dense bodies. Type III cells are small cells. The large nucleus shows prominent chromatin rim. The cytoplasm contains many ribosomes and mitochondria. Type IV cells are large, spheircal or oval cells. The nucleus is deeply indented. The plentiful cytoplasm contains large amount of ribosomes, mitochondria, Golgi complexes, neurotubules, but not r-ER. In the present study, it is clear that the nucleus accumbens septi and the nucleus fundus striati are independant cell groups, according to their cytoarchitectonics and the ultrastructural features of their cell types.

• Journal of fish pathology
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• v.29 no.1
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• pp.35-43
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• 2016

In comparison to the numbers of such studies of fish, few studies have been carried out on the immunity, physiology and ecology of abalone, while studies on abalone disease are also extremely rare. Moreover, mass mortality of cultured abalone due to pathogenic bacteria has not been reported in the southern coast of Korea. However, Vibrio-like bacteria have been isolated from dead abalone, which indicates that a review is required in order to determine the cause of abalone mortality. Use of an antimicrobial agent to minimize the damage caused by disease in abalone farms is common, but the therapeutic effects are insignificant. Demand for probiotics has increased, but research on the development of probiotics for use in abalone culture is very rare. Therefore, the present study isolated KC16-2 from fermented kimchi soup and investigated the characteristics of the isolate as a candidate probiotic bacterium in abalone. KC16-2 was identified as Bacillus amyloliquefaciens (B. amyloliquefaciens KC16-2) based on its biochemical properties and 16S rRNA gene sequence. B. amyloliquefaciens KC16-2 showed inhibitory effects against the growth of various vibrios in vitro, and kept the numbers constant until four days after inoculation in marine water at a temperature of $15{\sim}25^{\circ}C$, indicating the possible use of KC16-2 as a probiotic, except in the winter. The growth of KC16-2 was inhibited by bile salt, but the numbers increased over time suggesting the bacteria were still alive in the abalone's digestive tract. Abalone fed with a diet including KC16-2 for 12 weeks showed good growth, but showed no significant differences from the control group. However, the mortality of the abalone supplied the probiotic diet was reduced to half that of the control group in a challenge test with Vibrio tubiashii. Therefore, we suggest that B. amyloliquefaciens KC16-2 could be used as a probiotic bacterium for control of the mortality of abalone caused by opportunistic pathogenic vibrios.

• Journal of Life Science
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• v.26 no.1
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• pp.109-116
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• 2016

Ulmi cortex is the elm bark or root bark of Ulmus macrocarpa Hance and has been used as an ingredient of traditional medicine for anti-inflammatory, analgesic, anti-cancer and wound healing on both the East and the West. This study investigated whether the Ulmus macrocarpa Hance Water extract (UMWE) has the in vivo and in vitro immune activating effect. Animals were orally administrated for 14 days as follows: no treat group with distilled water, cyclophosphamide (CY) group with 120 mg/kg of CY, UMWE 100+CY group with 100 mg/kg of UMWE and 120 mg/kg of CY, UMWE 200+CY group with 200 mg/kg of UMWE and 120 mg/kg of CY, UMWE 100 group with 100 mg/kg of UMWE and UMWE 200 group with 200 mg/kg of UMWE. The immunosuppressive drug CY was intraperitoneally injected to induce immune suppression. Spleen indices showed small changes in CY injected groups but splenocyte indices showed greater decrease in the same groups. However, UMWE appeared to relieve CY’s immunosuppression. UMWE also delayed in vitro splenocyte death increasing its longevity. These data obtained by MTT assay and 7-amino-actinomycin D which stains preferentially dead than live cells. UMWE alone did not show cytotoxicity based on its apoptototic effect on splenocytes in vitro and in vivo. Splenic NK cell activity was maintained by UMWE under the presence of CY in vitro. The data indicated that UMWE protects splenocytes from the immunosuppressive drug CY under in vitro and in vivo conditions.

• Journal of Life Science
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• v.23 no.1
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• pp.116-124
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• 2013

The aim was to examine resistance exercise-related genes after 8 weeks of resistance training. Thirty-two male Sprague-Dawley rats were divided into four groups: 4 weeks sedentary (4 wks CON, n=8), 8 weeks sedentary (8 wks CON, n=8), 4 weeks exercise training (4 wks REG, n=8), and 8 weeks exercise training (8 wks REG, n=8). The rats were trained to climb a 1-m vertical incline (85-degree), with weights secured to their tails. They climbed 10 times, 3 days per week, for 8 consecutive weeks. Skeletal muscle was taken from the flexor halucis longus after the exercise training. After separating the total RNA, large-scale gene expression was investigated by beadarray (Illumina RatRef-12 Expression BeadChip) analysis, and qPCR was used to inspect the beadarray data and to analyze the RNA quantitatively. The detection p-value for the genes was p<0.01, the M-value {M=$log_2$(condition)-$log_2$(reference)} was >1.0, and the DiffScore was >20. In total, the expression of 30 genes significantly increased 4 weeks after the exercise training, and the expression of six genes decreased. At 8 weeks, the expression of five genes significantly increased and that of 12 decreased. Several genes are potentially involved in resistance exercise and muscle hypertrophy, including 1) regulation of cell growth (IGFBP1, PLA2G2A, OKL38); 2) myogenesis (CSRP3); 3) tissue regeneration and muscle development (MUSTN1, MYBPH); 4) hypertrophy (CYR61, ATF3, NR4A3); and 5) glucose metabolism (G6PC, PCK1). These results may help to explain previously reported physiological changes of the skeletal muscle and suggest new avenues for further investigation.