• Bulletin of the Korean Chemical Society
• /
• v.18 no.7
• /
• pp.761-766
• /
• 1997

Phospholipase C from Clostridium perfringens is known to catalyze the hydrolysis of phospholipids in biological membranes. In this study, a simple and sensitive method for assaying phospholipase C was developed by using liposomes entrapping calcein as a fluorescent marker. Phospholipase C-induced lysis of liposomes was determined by measuring the fluorescence intensity of calcein released out from liposomes, Various liposomes with different compositions were prepared by reverse-phase evaporation method to investigate the effect of liposomal composition on the lytic activity of phospholipase C. The calcein-entrapping efficiency of liposomes was affected by the chain length of fatty acid in phosphatidylcholine constituting liposomes. The lytic activity of phospholipase C was the highest against liposomes prepared with eggPC. The lytic activity decreased with increasing chain length of fatty acid in phosphatidylcholine. Incorporation of cholesterol more than 20% into the liposomal bilayer inhibited the phospholipase C-induced lysis. The lysis of liposomes was more greatly increased by the addition of 10 mM of calcium. The lytic activity of phospholipase C was also affected by the surface charge of liposomes. Taken together, it was concluded that reverse-phase evaporation vesicles composed of dipalmitoylphosphatidylcholine and cholesterol in the molar ratio of 9 : 1 allowed to detect the lowest concentration of phospholipase C (0.10 μg/assay volume). This study suggested that the use of liposomes can provide a simple, sensitive and inexpensive method for assaying phospholipase C.

• Journal of Veterinary Clinics
• /
• v.40 no.2
• /
• pp.139-146
• /
• 2023

Three dogs were referred with epistaxis and facial deformity. Computed tomography (CT) scan identified masses in the bilateral nasal cavity with soft tissue attenuation and contrast enhancement. These masses had caused adjacent bones lysis, especially lysis of cribriform plate that extended to the intracranial region. Base on histopathology and CT imaging results, tumors were diagnosed as nasal carcinomas at stage 4. Three dogs were treated with stereotactic radiation therapy (SRT). These dogs received 30-35 Gy from 3-5 daily treatments (7-10 Gy per treatment). The sizes of tumors decreased the most on follow-up CT images at one month after treatment. Recurrence was confirmed between 3 and 5 months after completing SRT. The survival time of dogs treated with SRT were 110, 190, and 210 days, respectively. This study confirmed that SRT could treat canine nasal carcinomas with cribriform plate lysis without causing serious radiation toxicities. Follow-up CT examination is considered at 1 month and 3 to 6 months after SRT to accurately evaluate the prognosis and the timing of recurrence.

• Journal of Korean Society of Environmental Engineers
• /
• v.22 no.5
• /
• pp.849-859
• /
• 2000

This study was conducted to identify the characteristics of methane fermentation and lysis effects of pre-treated microalgae. Chemical compositions of microalgae showed that the VS(volatile solid) was 86.1% of TS(total solid), and the protein was 63.5% of VS. These values were higher than those of activated sludge. The cell lysis test of raw microalgae biomass was conducted by many physicochemical methods. presenting that the degree of cell lysis was affected by following order: ultrasonic(100min.), alkali(pH 13), ultrasonic(10min), thermal($120^{\circ}C$), thermal($50^{\circ}C$), and acidic(pH 3) treatment. Methane fermentation with many pre-treated samples was performed, showing that the concentration of acetic acid was the highest. followed by propionic acid, butylic acid and valerie acid among all VFA(volatile fattic acid). In methane production. ultrasonic samples were only more effective than untreated one in total gas and methane productivity. but other samples were less effective. Especially. the alkalic sample had an inhibitation effect on methanogens.

• Tuberculosis and Respiratory Diseases
• /
• v.40 no.1
• /
• pp.43-51
• /
• 1993

Background: The polymerase chain reaction (PCR) is a very sensitive method for the detecting of mycobacterial DNA. There are many reports revealing the efficacy of PCR for the diagnosis of M. tuberculosis, but there are many different methods for DNA extraction from Mycobacterium tuberculosis. Bead beater method is a very useful method for DNA extraction from clinical spectimens, but its procedures are relatively complicated and time-consuming. So we studied other methods for the DNA extraction from Mycobacterium tuberculosis $H_{37}Rv$ and some clinical specimens (5 smear positive sputa and 5 smear negative CSF). Method: We extracted the mycobacterial DNA with 6 different methods from H37Rv strain and clinical specimens. The methods included SDS-microwave oven method, NaOH lysis method, Triton X-100-Proteinase K method, Lysis buffer method, SDS-proteinase K method and bead beater method. The target DNA was 123bp of IS6110 and was detected by examination of ethidium bromide-stained agarose gels. Results: Among 6 methods, SDS-proteinase K method, bead beater method, lysis buffer method and triton X-100-proteinase K method were excellent, but SDS-proteinase K method was the best method in the aspect of simplicity and cost-effectiveness. Conclusion: We suggest that SDS-porteinase K method is a simple and convinient method and might be the best method for the extraction of mycobacterial DNA.

• The Journal of the Korean dental association
• /
• v.11 no.8
• /
• pp.525-530
• /
• 1973

True collagenolytic enzymes in animal tissues were first demonstrated by Gross and Lapiere (1962), who showed the ability of such an enzyme in the culture medium of living explants of tadpole tissue to degrade a specific substrate of undenatured collagen under physiological conditions. Recently, tumor-associated collagenolytic activity has been demonstrated in human neoplasm and in ascites V Carcinoma. This investigation have been peforme to determine whether or not a collagen lytic enzyme could e found in isolated solid Tawa sarcoma of Donryu female rat obtained the culture medium. The results were as follows. 1. 11.5mg% of hydroxyproline contained in Donryu rat skin collagen, which was extracted by 0.5M acetic acid. 2. Cultivation of solid Tawa sarcoma tissues on reconstituted rat skin collagen gels showed lysis of adjacent gel after 18 hours, and much more extensive lysis after 5 days. 3. Collagen substrate was not attacked by the common proteolytic enzymes, trypsin, pepsin, and pronase.

• Journal of Environmental Science International
• /
• v.9 no.4
• /
• pp.331-337
• /
• 2000

The variation of microorganisms (activated slude, Saccharomyces cerevisiae, Aureobasidium pullulans) caused by the biosorption of $Pb^{2+}$ was observed by TEM and microscope. By the TEM observation of S. cerevisiae, the plasmolysis and lysis of cell wall or cell membrane were occurred by the penetration of $Pb^{2+}$ into the inner cellular region. However, in the case of A. pullulans, the plasmolysis and lysis of cell wall or cell membrane were not occurred because of the prevention of $Pb^{2+}$ penetration by the extracelluar polymeric substances (EPS). A flocculation of microorganisms, in the case of A. pullulans, was observed by the $Pb^{2+}$ accumulation after 3~4 h and the color was changed from white to black after 1 day. The flocculation of activated sludge was improved by the accumulation $Pb^{2+}$ after 1 h, however, the floc was broken up and the settling efficiency decreased after 1 day.

• Journal of Veterinary Clinics
• /
• v.18 no.1
• /
• pp.82-84
• /
• 2001

An 11 kg, 7-year-old male pug dog with lameness and tumor of the 2-3rd interdigital portion of the right forelimb was referred to the Veterinary Medical Center of the Tokyo University. On the clinical examination findings, the tumor size was $3{\times}3 cm but alopecia and necrosis were not found. On the radiological findings, a bone lysis was found in the phalanges of digit II of the right forelimb but pulmonary metastasis was not found. The mass was removed with metacarpal bone. Histopathological examination of the mass revealed highly differentiated hemangiopericytoma. Two weeks after the operation, the dog was irradiated by orthovoltage radiation. The source of irradiation was 300 kV, 4mA, 4Gy and a focal spot to skin distance of 40 cm using 1.0 Cu, 1.0Al filter. The radiation therapy was performed twice a week for 5 weeks. The dog showed no recurrence and no metastasis. It was thought that the surgery and radiation therapy treatment was quite a useful method to treat a canine heman-giopericytoma.

• The Journal of the Korean dental association
• /
• v.41 no.12 s.415
• /
• pp.818-824
• /
• 2003

Visually guided irrigation and lysis(VGIL) using temporomandibular joint(TMJ) arthroscope is useful for decreasing pain and increasing the functional mobility of TMJ. Also it demonstrated similar effectiveness comparing with arthrocentesis. Arthroscopy permits intracapsular inspection that is imperative not only for identification of morphological characteristics of joint space, but also for adequate irrigation and lysis of specific joint space. Conventional 2.3mm diameter arthroscope with 2.7mm catheter was too wide. So it was traumatic and uncomfortable to manipulate on temporomandibular joint space, especially on TMJ internal derangement patient with reduced space. We report our clinical experience on 6 TMJ closed lock patients who were treated with new 1.2mm fiberscope at Chung Hoon Dental Clinic between March 2003 and August 2003. Also we present clinical advantage & disadvantage of new system with literature review.

• BMB Reports
• /
• v.28 no.5
• /
• pp.443-450
• /
• 1995

Cloned staphylococcal peptidoglycan hydrolase was used in determining the physiological characteristics of peptidoglycan hydrolase. This enzyme hydrolyzed the bacterial cell walls and released the N-terminal alanine, but not the reducing groups. This cloned gene product was localized in the cytoplasm of transformed Escherichia coli. Activity gels indicated the enzyme had an Mr of about 54,000, which was consistent with the deduced Mr from sequencing of the cloned gene. The activity bound to CM-cellulose but not DEAE-cellulose resin, indicating it as a basic protein. Enhanced enzyme activity in a low concentration of cations, and inhibited enzyme activity in a solution with dissolved phospholipids, suggested that the activity and the availability of this basic protein may be regulated between negatively charged and positively charged cellular molecules. The activity against boiled crude cell wall was much greater than against purifed cell wall, suggesting protein associated with crude cell wall may aid in the binding of the peptidoglycan hydrolase The cloned peptidoglycan hydrolase showed positive activity on whole cells of some lysostaphin-resistant coagulase-negative staphylococci. The cloned enzyme may be an alternative for lysostaphin for lysis of staphylococci.

• ALGAE
• /
• v.18 no.4
• /
• pp.355-360
• /
• 2003

A Gram (-), rod-shaped bacterium in size of 1.6-2.8 $\times$ 0.4 μm was isolated from a eutrophic reservoir, which exhibited growth-inhibiting effect against a bluegreen alga (Anabaena cylindrica). This isolate showed positive reactions for catalase and oxidase, and optimal conditions of 35-40°C and pH 9.0. This isolate was designated AC-1 in this manuscript. In a mixed-culture of A. cylindrica and AC-1, their growth patterns were inversely correlated and the bluegreen algal vegetative cells completely disappeared within 24-36 hours. AC-1 showed similar lytic activity in natural water as in an artificial medium. The lytic activity of AC-1 was dependent on the photosynthetic activity of A. cylindrica. When observed under phase contrast microscope, the isolate lysed vegetative cells of A. cylindrica in scattered state in a liquid medium, whereas heterocysts have not been lysed.