• 한국축산식품학회지
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• 제35권6호
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• pp.800-806
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• 2015

We investigated the effects of a pulsed electric field (PEF) treatment on microbial inactivation and the physical properties of low-fat milk. Milk inoculated with Escherichia coli, Saccharomyces cerevisiae, or Lactobacillus brevis was supplied to a pilot-scale PEF treatment system at a flow rate of 30 L/h. Pulses with an electric field strength of 10 kV/cm and a pulse width of 30 µs were applied to the milk with total pulse energies of 50-250 kJ/L achieved by varying the pulse frequency. The inactivation curves of the test microorganisms were biphasic with an initial lag phase (or shoulder) followed by a phase of rapid inactivation. PEF treatments with a total pulse energy of 200 kJ/L resulted in a 4.5-log reduction in E. coli, a 4.4-log reduction in L. brevis, and a 6.0-log reduction in S. cerevisiae. Total pulse energies of 200 and 250 kJ/L resulted in greater than 5-log reductions in microbial counts in stored PEF-treated milk, and the growth of surviving microorganisms was slow during storage for 15 d at 4℃. PEF treatment did not change milk physical properties such as pH, color, or particle-size distribution (p<0.05). These results indicate that a relatively low electric-field strength of 10 kV/cm can be used to pasteurize low-fat milk.

• 대한약리학회지
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• 제25권1호
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• pp.23-30
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• 1989

함께 투여되는 마약성진통제에 따라 효능제 또는 길항제(mixed agonist-antagonist)로 작용하는 buprenorphine을 사용하여 개구리 좌골신경에 존재하는 아편수용체의 성질을 검토하였다. 실험은 sucrose-gap apparatus를 사용하여 활동전압에 대한 영향을 관찰하였으며 약물의 상호작용을 검토하고자 meperidine 또는 naloxone을 사용하여 다음과 같은 결과를 얻었다. 1) Buprenorphine은 현저하게 개구리 좌골신경의 활동전압을 저하시켰다. 2) 두 개의 최고작용농도를 보였는데 저농도에서는 $10^{-8}\;M$, 또 고농도에서는 $10^{-4}\;M$에서 현저하게 작용을 나타내었다. 3) Buprenorphine은 meperidine의 활동전압 저하작용을 의의있게 억제하였다. 4) Naloxone에 의하여 Buprenorphine의 저하 작용이 억제되었다. 위의 실험결과로 Buprenorphine은 순수 마약성진통제의 작용을 억제하여 차단제로 작용하는 한편 또한 효능제로 활동전압을 의의있게 억제하였다. 이로써 개구리 좌골신경에 있는 아편수용체는 세포막에 또는 세포막 주위에서 $Na^+-Channel$이 활성화되는 데 중요한 역할을 하는 것으로 간주되며 이 수용체는 또한 Naloxone에 매우 민감한 반응을 나타낸다.

• 한국결정성장학회지
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• 제30권4호
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• pp.143-149
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• 2020

전복패각을 Ca원으로 이용하여 바이오 소재로 중요한 인산칼슘(calcium phosphates)들을 침전법을 통해 합성하였다. 전복패각에서 유래한 수산화칼슘(Ca(OH)₂)을 칼슘 공급원(전구체)으로 사용하였다. 수용액상에서 수산화칼슘과 인산(H₃PO₄)을 반응시켜 침전반응을 유도하여 인산칼슘화합물로의 합성을 유도하였다. 초기 전구체 Ca/P 비율을 1.50, 1.59 및 1.67로 조절하였으며 이 조성변화와 침전물에 대한 열처리가 분말 및 소결체의 물성에 미치는 영향에 대해 조사하였다. 초기 전구체 Ca/P 비율을 조절함으로써 소결체 상합성의 조절이 가능하였고, 1150℃에서 소결한 소결체에서(hydroxyapatite(HAp), β-tricalcium phosphate(β-TCP) 및 HAp와 β-TCP가 혼합된 2상 인산칼슘(BCP, HA/β-TCP))들이 합성되었다. 이러한 결과는 저비용, 고가용성을 가지는 경제적인 출발물질로부터 고부가가치 인산칼슘을 합성할 수 있는 가능성을 보여주었다.

• Journal of Oral Medicine and Pain
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• 제25권1호
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• pp.53-62
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• 2000

Bone marrow culture systems are widely used to differentiate osteoclast-like cells in vitro using several osteotropic hormones. In this study, we isolated and cultured the mouse bone marrow cells with or without some osteotropic hormones such as parathyroid hormone(PTH), prostaglandin $E_2(PGE_2)$ and $l,25(OH)_2-vitamin$ $D_3$(Vit. $D_3$). We confirmed the formation of osteoclast-like cells morphologically and functionally by the expression of tartrate-resistant acid phosphatase(TRAP) and by their capability to resorb dentin slices. We also studied the effects of transforming growth $factor-{\beta}(TGF-{\beta})$ and epidermal growth factor(EGF) on the Vit. $D_3-induced$ osteoclast-like cell formation. In control, a few multinucleated cells were formed whereas PTH and $PGE_2$ increased the number of multinucleated cells. PTH, $PGE_2$ and Vit. $D_3$ induced the formation of TRAP-positive multinucleated cells. After culture of mouse bone marrow cells on the dentin slices with or without osteotropic hormones, giant cells with diverse morphology were found on the dentin slices under the scanning electronmicroscopy. After removing the attached cells, resorption pits were identified on the dentin slices, and the shape of resorption pits was variable. EGF increased the osteoclast-like cell formation induced by Vit. $D_3$, however, $TGF-{\beta}$ showed biphasic effect, which at low concentration, increased and at high concentration, decreased the osteoclast-like cell formation induced by Vit. $D_3$.

• Journal of Periodontal and Implant Science
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• 제40권3호
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• pp.125-131
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• 2010

Purpose: Among available biomaterials, bioceramics have drawn special interest due to their bioactivity and the possibility of tailoring their composition. The degradation rate and formulation of bioceramics can be altered to mimic the compositions of the mineral phase of bone. The aim of this study was to investigate the bone formation effect of amorphous calcium phosphate glass cement (CPGC) synthesized by a melting and quenching process. Methods: In five male beagle dogs, $4{\times}4$ mm 1-wall intrabony defects were created bilaterally at the mesial or distal aspect of the mandibular second and fourth premolars. Each of the four defects was divided according to graft materials: CPGC with collagen membrane (CM), biphasic calcium phosphate (BCP) with CM, CM alone, or a surgical flap operation only. The dogs were sacrificed 8 weeks post-surgery, and block sections of the defects were collected for histologic and histometric analysis. Results: There were significant differences in bone formation and cementum regeneration between the experimental and control groups. In particular, the CPGC and BCP groups showed greater bone formation than the CM and control groups. Conclusions: In conclusion, CPGC was replaced rapidly with an abundant volume of new bone; CPGC also contributed slightly to regeneration of the periodontal apparatus.

• 대한치과마취과학회지
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• 제3권2호
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• pp.92-97
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• 2003

Background: Gabapentin is a novel anti-epileptic drug, which is used in clinical practice to treat epilepsy. This drug is also used as an analgesic in pain patients. The antinociceptive effect of this drug was assessed using the formalin test in the rat. Methods: In order to investigate the effects of gabapentin on the trigeminal nerve territory, we injected 0.5% formalin into the upper lip. Adult, male, Sprague-Dawley rats received a $50{\mu}l$ subcutaneous injection of 5% formalin into one vibrissal pad and the consequent, facial grooming behavior was monitored. Consistent with previous investigations using tile formalin model, animals exhibited biphasic nocifensive grooming (phase 1, 0-12 min; phase 2, 12-60 min). Results: The intraperitoneal administration gabapentin 5 minutes prior to the formalin injection led to a significant, dose-dependent reduction in grooming time during phase 2. In high doses, gabapentin also reduced the time of grooming during phase 1. Conclusions: The Intraperitoneal injection of gabapentin has an analgesic effect in the facial formalin rat model and this analgesic effect increases dose-dependently.

• 대한세포병리학회지
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• 제12권2호
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• pp.97-103
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• 2001

Carcinoma ex pleomorphic adenoma(CXPA) is a rare malignant tumor of the salivary gland, fine needle aspiration cytology(FNAC) of which are rarely reported. We retrospectively reviewed FNAC of five cases of histologically proven CXPA of the salivary glands diagnosed in Seoul National University Hospital to evaluate their cytologic characteristics. Histologically, the carcinoma components were low-grade in three cases and high-grade in two cases. The cytologic diagnosis were malignancy in two cases(40%), suspicious for malignancy in one(20%), and benign(pleomorphic adenoma) in two(40%). All of the high-grade carcinomas were correctly diagnosed by FNAC, however, 2 cases of low-grade carcinomas were diagnosed as benign by FNAC. The low sensitivity in cytologic diagnosis is due to interpretative difficulties in low-grade tumors. The characteristic cytologic features of CXPA were high cellularity, necrotic, bloody, and inflammatory background, marked nuclear overlapping, coarsely granular chromatin, prominent macronucleoli, and atypical mitosis in epithelial component in addition to the typical biphasic pattern of pleomorphic adenoma consisting of epithelial cells admired with spindle-shaped cells and chondromyxoid stroma. Even though low-grade tumors show mild pleomorphism, the cytologic findings of necrotic background, moderate to high cellularity, and nuclear overlapping could lead to an accurate cytodiagnosis of CXPA.

• 한국의류학회지
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• 제34권4호
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• pp.653-662
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• 2010

This study investigates the effect of particle size on the detergency of particulate soil using an $\alpha-Fe_2O_3$ particle as the model. Monodispersed spherical $\alpha-Fe_2O_3$ particles were prepared by the hydrothermal aging of an acidic $FeCl_3$ and HCl solution. The $\xi$-potential of PET fiber was measured by the streaming potential method. The potential energy of interaction between the particle and fiber was calculated using the heterocoagulation theory for a sphere-plate model. The $\xi$-potential of PET fiber and potential energy of interaction between particles and fiber increased with a decreasing particle size in a DBS solution. However, in the nonionic surfactant solution, the $\xi$-potential signs of PET fiber and $\alpha-Fe_2O_3$ particles were (-) and (+), respectively; there was no repulsive power between the particles and substrate. The adhesion of particles to the fabric increased with increasing particle size in the anionic surfactant solution and their removal from the fabric increased with a decreasing particle size. The adhesion of particles to the fabric and their removal from the fabric was biphasic with a maximum and minimum at 0.1% concentration of the surfactant solution. In the nonionic surfactant solution the adhesion of particles to fabric and their removal from the fabric were greater than the ones in the anionic surfactant DBS solution.

• 생명과학회지
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• 제10권5호
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• pp.456-466
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• 2000

Aquaperin 4 (AQP4) is the mercurial water channel expressed abundantly in brain, especially the region related with cerebrospinal fluid reabsorption and osmoregulation. The primary structure of AQP4 water channel was elucidated but the molecular mechanism of AQP4 channel regulation is still unknown. To investigate the possible regulation of AQP4 water channel by phosphorylation via various protein kinases, osmotic water permeability of AQP4 expressed in Xenopus oocytes was measured by videomicroscopy technique. Forskolin (10 $\mu$M) did not affect osmotic water permeability of oocytes injected with AQP4 cRNA, excluding the regulation of AQP4 water cnannel by protein kinase A. Osmotic water permeability (P아래첨자) of AQP4-expressed oocytes was ingibited by the pretreatmeat of BAPTA/AM (up to 500$\mu$M), an intracellular Ca윗첨자 chelator, and calmidazolium (100$\mu$M), a specific Ca윗첨자/calmodulin antagonist, in a dose-dependent manner. The inhibition of osmotic water permeability (P아래첨자) by the calmidazolium treatment was completely reversed by the addition of calyculin A (0.1$\mu$M), a nonspecific phosphatase inhibitor. Phorbol 12-myristate 13-acetate (PMA), a protein kinase C activator, had biphasic effects on osmotic water permeability in AQP4 cRNA injected oocytes depending on its concentration; 21% increase by 100 nM PMA, 35% decrease by 1$\mu$M PMA. These effects were reversed with 2$\mu$M staurosporine, a nonspecific PKC inhibitor. These results suggest that phosphorylation of AQP4 water channel by Ca윗첨자/calmodulin kinase and protein kinase C might regulate the osmotic water permeability.

• Journal of Chest Surgery
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• 제42권3호
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• pp.388-391
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• 2009

분화가 좋은 태아성 선암종은 $10\sim15$주의 태아폐와 유사하며 풍부한 당원을 가지는 종양성 선과 관성구조로 이루어진 드문 폐종양으로 폐모세포종이나 폐선암의 아형으로 분류되어지나 예후는 전형적인 폐모세포종(이형성 모세포종)이나 폐선암보다는 좋다. 젊은 환자에서 악성의 정도가 낮은 종양을 확인하는 것은 높은 생존율과 연관되므로, 저자들은 현재까지 종양의 재발 없이 생존하고 있는 3명의 환자에서 경험한 분화가 좋은 태아성 선암종에 대해 보고한다.