• Biotechnology and Bioprocess Engineering:BBE
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• 제6권6호
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• pp.410-418
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• 2001

The effects of several variables on the refolding of hen egg white lysozyme have been studied, Lysozyme was denatured in both urea, and guanidine hydrochloride(GuHCl), and batch refolded by dilution (100 to 1000 fold) into 0.1 M Tris-HCI, pH 8.2 mM EDTA 3 mM reduced glutathione and 0.3 mM oxidised glutathions. Refolding was found to be sensitive to temperature, with the highest refolding yield obtained at 50$\^{C}$. The apparent activation energy for lysozyme re-folding wasf ound to be 56kJ/mol, Refolding by dilution results in low concentrations of both de-naturant and reducing agent species. It was found that the residual concentrations obtained dur-ing dilution(100-fold dilution:[GuHCI]=0.06 mM, [DTT]=0.15 mM) were significant and could inhibit lysozyme refolding. This study has also shown that the initial protein concentration (1-10mg/mL) that is refolded is an important parameter. In the presence of residual GuHCl and DTT higher refolding yields were obtained when starting from higher initial lysozyme concentra-tions. This trend was reversed when residual denaturant components were removed from the re-folding buffer.

• The Journal of Korean Physical Therapy
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• 제33권6호
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• pp.304-306
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• 2021

Objectives: We report on a patient who showed mild bradykinesia due to injury of the corticofugal tract (CFT) from the secondary motor area following direct head trauma, which was demonstrated on diffusion tensor tractography (DTT). Case summary: A 58-year-old male patient underwent conservative management for subarachnoid hemorrhages caused by direct head trauma resulting from a fall from six-meter height at the department of neurosurgery of a local hospital. His Glasgow Coma Scale score was 3. He developed mildly slow movements following the head trauma and visited the rehabilitation department of a university hospital at ten weeks after the fall. The patient exhibited mild bradykinesia during walking and arm movements with mild weakness in all four extremities (G/G^-). Results: On ten-week DTT, narrowing of the right CFT from the supplementary motor area (SMA-CFT), and partial tearing of the left SMA-CFT, left CFTs from the dorsal premotor cortex (dPMC-CFT) and both corticospinal tracts (CSTs) at the subcortical white matter were observed. Conclusion: This case demonstrated abnormalities in both CSTs (partial tearing at the subcortical white matter and narrowing), both SMA-CFTs (narrowing and partial tearing) and left dPMC-CFT. We believe our findings suggest the necessity of assessment of the CFTs from the secondary motor area for patients with unexplained bradykinesia following direct head trauma.

• Journal of Yeungnam Medical Science
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• 제39권4호
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• pp.332-335
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• 2022

We report on changes in the ascending reticular activating system (ARAS) concurrent with the recovery of impaired consciousness following rehabilitation and cranioplasty in a patient with traumatic brain injury (TBI), which were demonstrated on diffusion tensor tractography (DTT). A 34-year-old male patient was diagnosed with a traumatic intracerebral hemorrhage after falling from a height of approximately 7 m and underwent a right frontoparietotemporal decompressive craniectomy and hematoma removal. At 5 months after onset, when starting rehabilitation, the patient showed impaired consciousness, with a Glasgow Coma Scale (GCS) score of 4. Comprehensive rehabilitative therapy was provided until 14 months after onset, and his GCS score improved to 8. Cranioplasty was performed using auto-bone at 14 months after onset. One month after cranioplasty, his GCS score improved to 12. On the 15-month DTT, the deviated lower dorsal ARAS was restored on both sides, and the right side had become thicker. The right lower ventral ARAS was reconstructed, and increased neural connectivity of the upper ARAS was detected in both the prefrontal cortices. Thus, changes in the ARAS were demonstrated in a patient with TBI during recovery of consciousness following rehabilitation and cranioplasty.

• Restorative Dentistry and Endodontics
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• 제22권1호
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• pp.76-92
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• 1997

Porpilyromonas endodontalis is specifically involved in endodontic infections. The bacterium can be isolated almost exclusively only from infected rool canals. P. gingivalis also has been implicated in endodontic infection. Pathogemcity of P. gingival is is attributed to a variety of virulence factors, especially proteases, produced by the bacterium. Importance of P. endodontalis in endodontic infection has been revealed. However, the pathogenic property of P. endodontalis has not been extensively studied. The present study was undertaken to characterize the proteolytic activity of P. endodontalis and compare the activity with that of P. gingivalis which has the most potent and diverse proteases among oral bacteria. For this purpose, culture supematants(SUP) and cell extracts(CE) were obtained from these two bacteria and were subjected to zymography using 15% polyacrylamide gel copolymerized with gelatin, type I, IV collagens or albumin. Hydrolysis of the collagens was further investigated by the cleavage assay using native type I and IV collagens in solution-phase. The results were as follows: 1. P. endodontalis apparently has a proteolytic activity that is comparable with that of P. gingivalis. 2. SUP and CE obtained from P. endodontalis and P. gingival is showed the strongest activity for gelatin, followed by type I and IV collagens, and albumin. 3. In the zymography, no noticeable difference in proteolytic activity for gelatin and albumin between the SUP and CE was observed, but in the cleavage assay using native collagens, the SUP showed a stronger collagenolytic activity than the CE. 4. The gelatinolytic activity of both the SUP and CE from these two bacteria was diminished in the presence of $CaCl_2$ or reducing agents such as ${\beta}$-mercaptoethanol and dithiothreitol(DTT). 5. Type I(calf skin and human placenta) collagenolytic activity of P. endodontalis and P. gingivalis was reduced by DTT but not affected by $CaCl_2$. The inhibitory effect of DTT, however, was reduced to some extent by $CaCl_2$. 6. Type IV collagenolytic activity of these two bacteria was not affected by $CaCl_2$ but increased to some extent in association with the reducing agents. 7. Hydrolysis of albumin by P. endodontalis and P. gingivalis was demonstrated only in the presence of the reducing agents. The overall results indicate that with respect to proteolytic activity, P. endodontalis appears to be as potent as P. gingivalis, or maybe more, and its proteolytic characteristic is similar to that of P. gingivalis. This suggests that P. endodontalis has so potent proteolytic activity that can participate by itself in endodontic infections and apical periodontitis, causing tissue destruction.

• 한국산림과학회지
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• 제74권1호
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• pp.29-36
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• 1986

이태리포푸라 I-214 (Populus euramericana cv. I-214)의 기내배양(器內培養)한 엽육조직(葉肉組織)에서 원형질체(原形質體) 분리(分離)에 미치는 몇가지 요인(要因)에 대(對)해 조사(調査), 검토(檢討)하였다. 기내(器內)에서 배양(培養)된 아(芽)를 다량(多量)으로 증식(增植)하기 위한 배지(培地)는 MS 기본배지(基本培地)에 $0.1mg/{\ell}$의 BAP를 첨가(添加)한 것이 가상 좋은 성적을 나타냈다. 엽(葉) 1g 당(當) $2.4{\times}10^6$개의 가장 높은 원형질체(原形質體) 분리(分離) 빈도를 나타낸 것은 Cellulase R-10 2 %, Macerozyme R-10 0.8 %, Hemicellulase 1.2 %, Driselase 2.0 %, Pectolyase Y-23 0.05 %에 DTT와 MES 완충액을 첨가(添加)한 후 삼투압 안정제로 0.6 M의 Mannitol을 넣고 pH를 5.6으로 조정한 효소용액(酵素溶液)이었다. CPW 용액(溶液)으로 세정(洗淨)한 후 0.6 M의 Sucrose 용액(溶液)에 처리(處理)한 것이 회수율(回收率) 51.8 %로 가장 높게 나타났다.

• Toxicological Research
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• 제32권2호
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• pp.133-140
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• 2016

Sulfasalzine is a widely administered drug against inflammatory-based disorders in human. However several cases of liver injury are associated with its administration. There is no stabilized safe protective agent against sulfasalazine-induced liver injury. Current investigation was designed to evaluate if N-acetylcysteine (NAC) and dithioteritol (DTT) as thiol reducing agents and/or vitamins C and E as antioxidants have any protective effects against sulfasalazine-induced hepatic injury in an ex vivo model of isolated rat liver. Rat liver was canulated and perfused via portal vein in a closed recirculating system. Different concentrations of sulfasalazine and/or thiol reductants and antioxidants were administered and markers of organ injury were monitored at different time intervals. It was found that 5 mM of sulfasalazine caused marked liver injury as judged by rise in liver perfusate level of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) (p < 0.05). A significant amount of lipid peroxidation and hepatic glutathione depletion were detected in drug-treated livers, accompanied with significant histopathological changes of the organ. Administration of NAC ($500{\mu}M$), DTT (${400\mu}M$), Vitamin C ($200{\mu}M$), or vitamin E ($200{\mu}M$) significantly alleviated sulfasalazine-induced hepatic injury in isolated perfused rat liver. The data obtained from current investigation indicate potential therapeutic properties of thiol reductants and antioxidants against sulfasalazine-induced liver injury.

• 미생물학회지
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• 제37권3호
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• pp.204-208
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• 2001

Bacillus속에 속하는 세균을 FISH 방법으로 검출하기 위한 새로운 방법을 개발하였다. LGC353b, S-G-Bacill-0597-a-A-22와 S-G-Bacill-0597-a-S-22 등 3개의 probe를 22종의 Bacillus속 세균의 혼합배양액에 적용한 결과 S-G-Bacill-0597-a-A-22의 probe가 DAPI로 검출된 세균 중 95%가 FISH로도 측정되어 가장 효율이 좋은 것으로 나타났다. Hybrillization 과정 전에 Bacillus의 영양세포와 포자의 세포벽을 파괴하기 위하여 SDS/DTT (dithiothreitol)와 lysozyme를 순차적으로 전처리하는 방법과 lysozyme용액으로만 전처리 하는 두 가지 방법을 사용하였다. 그 결과, Bacillus를 검출하기 위해서는 영양세포의 경우에는 lysozyme용액으로만 전처리 하는 방법이 가장 좋았으며, 포자는 FISH로 검출되지 않았다. 따라서 토양, 하수 처리장등의 생태계에서 Bacillus를 검출할 경우에는 영양세포는 lysozyme으로 전처리 하여 FISH로 검출하고 포자는 따로 포자염색으로 검출하는 두가지 방법을 병행하여야한다.

• The Korean Journal of Physiology and Pharmacology
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• 제12권4호
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• pp.211-216
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• 2008

TREK (TWIK-RElated $K^+$ channels) and TRAAK (TWIK-Related Arachidonic acid Activated $K^+$ channels) were expressed in COS-7 cells, and the channel activities were recorded from inside-out membrane patches using holding potential of - 40 mV in symmetrical 150 mM $K^+$ solution. Intracellular application of an oxidizing agent, 5,5'-dithio-bis (2-nitrobenzoic acid) (DTNB), markedly decreased the activity of the TREK2, and the activity was partially reversed by the reducing agent, dithiothreitol (DTT). In order to examine the possibility that the target sites for the oxidizing agents might be located in the C-terminus of TREK2, two chimeras were constructed: TREK2 (1-383)/TASK3C and TREK2 (1-353)/TASK3C. The channel activity in the TREK2 (1-383)/TASK3C chimera was still inhibited by DTNB, but not in the TREK2 (1-353)/TASK3C chimera. These results indicate that TREK2 is inhibited by oxidation, and that the target site for oxidation is located between the amino acid residues 353 and 383 in the C-terminus of the TREK2 protein.

• 한국대기환경학회지
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• 제34권5호
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• pp.639-650
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• 2018

Identification of the major sources contributing to PM is of importance in order to understand their quantitative contributions to atmosphere. In the viewpoint of the meat cooking in Korea, only a few analyses of organic molecular markers have been conducted due to analytical difficulties. In this study, ten different parts of meat (i.e., blade shoulder, belly, and arm shoulder of pork; ribeye roll, top blade muscle, and short plate of beef; leg quarter, breast, and wing of chicken; duck; mackerel) were pyrolyzed to generate the cooked PM using an electronic heating plate. Generated PM were collected by the pyrolysis sampling system to identify total carbon (TC) using a carbon analyzer and cholesterol using a Liquid chromatography tandem-mass spectrometry (LC-MSMS) based on fragmentor voltage (FV), precursor ion, collision energy, product ion. In addition, oxydative potential (OP) analysis using dithiothreitol (DTT) method were discussed to investigate the toxicity relates. Highly correlated pairwise scatterplots between the cholesterol and TC indicate that oxydative potential was highly associated with different parts of meat. This study provides insight into the meat cooking components of PM, which could be drivers of the oxidative potential relates.

• 생명과학회지
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• 제13권5호
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• pp.618-625
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• 2003

목재 저장소의 토양에서 분리된 호열성 세균인 Paenibacillus sp. DG-22로부터 xylanase를 생산하기 위한 배양조건을 최적화시키기 위해 연구를 수행하였다. Xylanase생산은 세포의 생장과 연관된 양상을 나타내었다. Xylanase 활성은 배양상청액에서만 발견된 반면 $\beta-xylosidase$활성은 주로 세포와 결합되어 있었다. Xylanase활성의 형성은 자일란에 의해 유도되었고 포도당과 자일로스에 의해서 억제되었다. 여러 상업적 자일란을 이용하여 xylanase의 생산양상을 조사한 결과 0.1-0.5%의 birchwood xylan에서 가장 높은 생산율을 나타내었다. 조사된 여러 질소 원들 중 효모추출물이 xylanase생산을 위하여 최적이었다. xylanase의 활성은 $Co^{2+},\; Cu^{2+},\; Fe^{3+},\; Hg^{2+}\;$ 와$\; Mn^{2+}$ 이온들에 의하여 억제된 반면 $Ca^{2+},\; Mg^{2+},\; Ni^{2+},\; Zn^{2+}$ 이온들과 DTT에 의해서는 촉진되었다. 수은은 5 mM의 농도에서 xylanase 활성을 완전히 파괴하였다. 자일란 가수분해의 주된 산물은 자일로바이오스, 자일로트라이오스 그리고 자일로 올리고당이었고 이것은 이 효소가 endoxylanase라는 것을 나타낸다.