• Journal of the Korean Society of Food Science and Nutrition
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• v.12 no.4
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• pp.387-394
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• 1983

The factor, which was capable of accelerating the yeast cell wall lysis of the zymolyase(${\beta}-1$, 3-glucanase), was purified to a homogeneous state from the protease fraction of the crude zymolyase by Sephadex G-75 gel filtration and preparative polyacrylamide gel disc electrophoresis. The molecular weight of the purified factor was estimated to be 40,500 by SDS-polylacrylamide gel disc electrophoresis and it's iso-electric point was pH 9.6. The factor was found to be a basic protease consisted of single polypeptide chain with 395 amino acid residues and it showed the $E_{280,cm}^{1%}$ of 11.9 and the molecular extinction coefficient of $4.83{\times}10^4$, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.4
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• pp.472-476
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• 2008

The possibility of DNA comet assay as a rapid method for screening the irradiated vegetables and grains was evaluated. Vegetables (spring onion, garlic, and tomato) irradiated at $0{\sim}3$ kGy and grains (rice flour and black soybean) irradiated at $0{\sim}9$ kGy were used as samples. Optimum DNA comet assay conditions, such as elution, sedimentation of suspension, and lysis time of cell, were established. The optimum conditions for vegetables were 10 min for the elution time, 0 min for the sedimentation time, and 5 min for the lysis time. The optimum conditions for grains were 15 min for the elution time, 60 min for the sedimentation time, and 30 min for the lysis time. For the food application of DNA comet assay, it was possible to screen various food samples irradiated at the following doses: spring onion at 2 kGy, garlic at 3 kGy, tomato at 1 kGy, rice flour at 9 kGy, and black soybean at 3 kGy. Each sample showed different forms and sizes in DNA comet. Therefore, further studies on various methods using comet shape, concentration, or area in DNA comet assay are necessary.

• The Korean Journal of Physiology and Pharmacology
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• v.3 no.6
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• pp.597-603
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• 1999

Caldesmon (CaD), one of microfilament-associated proteins, plays a key role in microfilament assembly in mitosis. We have investigated the effects of overexpression of the high molecular weight isoform of CaD (h-CaD) on the physiology of vascular smooth muscle cells (VSMCs). Rat aortic VSMCs were stably transfected with plasmids carrying a full length human h-CaD cDNA under control of cytomegalovirus promoter. The majority of the overexpressed h-CaD appears to be localized predominantly on cytoskeleton structures as determined by detergent lysis. The overexpression of h-CaD, however, does not decrease the level of endogenous low molecular weight isoform of CaD. h-CaD overexpressing VSMCs (h-CaD/VSMCs) show a decreased growth rate than that of vector-only transfected cells when determined by $[^3H]thymidine$ uptake and cell counting after fetal bovine serum (FBS) stimulation. h-CaD/VSMCs were smaller than vector-transfected cells by 18% in cell diameter. These data suggest that overexpression of h-CaD can inhibit the poliferation and the cell volume of VSMCs stimulated by growth factors and that the gene therapy with h-CaD may be helpful to prevent the conditions associated with hypertrophy and/or hyperplasia of VSMCs after arterial injuries.

• Journal of Biomedical Engineering Research
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• v.41 no.1
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• pp.1-7
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• 2020

Polyvinyl alcohol (PVA)/gelatin hydrogels were prepared by repeating freezing/thawing three times to evaluate the influence of PVA concentration on the strength and the cell growth behavior of the PVA/gelatin hydrogels. The swelling rate of the PVA/gelatin hydrogels decreased with raising the PVA content from 6 wt% to 12 wt% due to the formation of 3-D network inside the hydrogel. No appreciable degradation of the hydrogels was detected. As the PVA content increased from 6 wt% to 12 wt%, the strength of the PVA/gelatin hydrogels increased drastically from 6.4±0.9 kPa to 46.6±9.0 kPa. The PVA/gelatin hydrogels did not show any evidence of causing cell lysis or toxicity, implying that the hydrogels are clinically safe and effective. Although the strength increased with increasing the PVA content, the PVA/gelatin hydrogels containing 8 wt% exhibited the fastest cell growth, which is highly suitable for wound dressing requiring fast healing regeneration.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.391-392
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• 2000

Tobacco cells transformed with hGM-CSF gene produced $162\;{\mu}g/L$ of hGM-CSF, a valuable therapeutic protein in seven days after inoculation. The protein concentration decreased after the maximum point. It is evidenced that the environment of cell culture was inappropriate for the stability of the protein(e.g., low osmolarity which can cause cell lysis).

• Natural Product Sciences
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• v.7 no.4
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• pp.114-119
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• 2001

The effect of Rhinacanthus nasutus leaf extract on the growth of dermatophytes had been investigated. In vitro the extract exhibited high activity against various species of dermatophytes (Trichophyton mentagrophytes var. mentagrophytes, T. mentagrophytes var. interdigitale, T. rubrum, Microsporum canis and M. gypseum). The minimal inhibitory concentration (MIC) values of the extract revealed that all the dermatophytes tested had MIC values of 13.6 mg/ml. The extract exhibited fungistatic activity at lower concentrations $({\leq}13.6\;mg/ml\;or\;below\;the\;MIC\;value)$ and fungicidal activity at higher concentrations $({\geq}13.6\;mg/ml$\;or\;above\;the\;MIC\;value)$. The results suggested that the extract acted on the cell wall of the dermatophytes which subsequently leading to the formation of cytopathological and membrane structural degeneration and finally leading to cell lysis and death.

• Journal of Sensor Science and Technology
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• v.23 no.1
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• pp.35-41
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• 2014

Microbes have been used extensively in various fields of researches and industries but has not been used widely for microfluidic biosensor applications because it is difficult to immobilize properly to a small space. Therefore, we developed a microbial immobilization method for microfluidic devices using single-walled nanotubes and dielectrophoretic force. Single-walled nanotubes and Escherichia coli were aligned between two cantilever electrodes by a positive dielectrophoretic force resulting in a film of single-walled nanotubes with attached Escherichia coli. The optimal condition of film formation without a cell lysis was investigated. Diameter of single-walled nanotubes and electric field (intensity and duration of application) had an effect on the cell viability. On the other hand, the cell concentration of the suspension did not affect the cell viability. Paraoxon was detected using single-walled nanotubes film with attached Escherichia coli that expressed organophosphorus hydrolase. This film which is suspended from the substrate showed faster response time than sensors that are not suspended from the substrate.

• The Korean Journal of Mycology
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• v.19 no.4
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• pp.282-284
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• 1991

The yeast, Hansenula anomala B-7, isolated from the $Cd^{2+}$ rich soils and determined to be tolerant in the high concentration of $Cd^{2+}$ were employed in this work. Its intact cells grown in high concentration of $Cd^{2+}$ were observed to be Iysed at the early stage when transferred to a cadmium deficient broth. Its intact cells found to be not Iysed and grow well under the high concentration of $Cd^{2+}$. The Iysis of the intact cells grown at the high concentration of $Cd^{2+}$ ion was not found when the metal ions were replaced with $Cd^{2+}$ ion in the same concentration. This result indicated that Iysis of yeast cells, at least in this isolate, would be related to cell osmosis with the mineral ions added.

• Journal of Veterinary Clinics
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• v.20 no.3
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• pp.399-402
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• 2003

A female unknown aged Yorkshire terrier, weighing 3.5 kg with nasal discharge, left facial swelling and severe inflammation was referred to Veterinary Medical Teaching Hospital, Seoul National University. Radiographic findings were lytic change and soft tissue swelling of left zygomatic process and increased radiopacity of nasal cavity. In computed tomography, turbinate bone destruction was observed as well as lytic change of left zygomatic process and left maxilla indicating aggressive lesion. Then 3-dimensional reconstruction was also performed. Biopsy of tissue mass revealed it as squamous cell carcinoma. For this patient, euthanasia was performed guarded prognosis. Generally, tumors of the nasal cavity in dogs account for approximately 1 % to 2% of all neoplasms. The prevalence of these tumors increased with age and exposure to the ultraviolet. About two thirds of all nasal tumors are malignant tumors such as squamous cell carcinoma and adenocarcinoma. As these tumors of nasal cavity are locally invasive, and external beam radiotherapy is the current treatment of choice. Unfortunately, diagnosis of these tumors often occurs late in the course of disease, resulting in a poor prognosis for outcome in many patients. It is considered that computed tomography could be used as an aid modality for the exact evaluation of extend and degree of bone lysis of nasal cavity and metastasis.

• Journal of Life Science
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• v.7 no.4
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• pp.282-288
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• 1997

To obtain a basic information on the development of Genus Viola, ultrastructure and electrofusion process between the two protoplasts from wild Viola callus cells and pansy mesophyll cells were observed with a scanning electron microscopy(SEM) and transmission electron microscopy(TEM). In the ultrastructural observation of wild viola callus protoplasts and pansy mesophyll protoplasts using SEM, their cell walls were removed completely. A knob-like formation was observed on the enlarge surface of viola callus protoplasts. On the surface of pansy mesophyll protoplasts net-like chloroplasts were observed. In SEM observation of pansy mesophyll protoplasts, chloroplasts devoid of membrane were observed on the surface the protoplasts. Pearl chain was formed by applying AC field of 200 V/cm at 1.0 MHz for 43 sec. The lysis of plasma membranes and fusion process occurred by applying a 1,600 V/cm DC pulse twice for 1 sec. After 1-2 hours of a DC pulse application, it was observed that the two protoplasts were fused completely into one cell. In TEM observation of the fused cell, many small vacuoles were located in the fusion area of the two protoplasts. Indeed, two distinct regions were observed during fusing process; in one region, a nucleus was found, while in the other region, both nucleus and nucleous were found.