• Animal cells and systems
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• 제2권1호
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• pp.145-152
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• 1998

The spinning apparatus and production of secretory silk from silk gland of the black widow spider, Latrodectus mactans were studied with scanning and transmission electron microscopes. The silk glands were located in seven groups on the spinnerets including each pair of major and minor ampullate, 3 pairs of tubuliform, 1 pair of flagelliform, 2 pairs of aggregate, about 50 pairs of pyriform and over 250 pairs of aciniform glands, respect- ively. Each group of silk gland feeds silk into one of the three spinneret pairs. Secretory silk is synthesized from rough endoplasmic reticulum (rER) of glandular epithelial cells. The secretory silk is transported from toe rER into the secretory vacuoles which are grown up by fusion with the surrounding small vesicles including the secretory silk. The secretory vacuoles, which show a gradual increase in electron density with the process of maturity, are formed without involvement of the Golgi complex, suggesting that they do not play an important role in the processing of the secretory silk. The secretory silk products are released by the mechanism of apocrine secretion, losing part of their cytoplasm. Moreover, another type of silk precursor, possibly protein, appears as granular material, and is also discharged to the luminal cavity.

• Archives of Pharmacal Research
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• 제7권2호
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• pp.87-93
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• 1984

The effects of ionic strength and pH on the binding of cefazolin to bovine serum albumin (BSA) were studied by UV difference spectrophotometry. As ionic strength at constant pH and temperature increases, the apparent bining constant decreased but the number of binding sites remained almost constant at 2. The constancy of the number of binding sites with increasing the ionic strength suggests that purely electrostatic forces between BSA and drug do not have great importance in the drug binding, even though there is a decrease in the apparent binding constant. Thus, the effect of ionic strength on the interaction between drug and BSA may be explained by the changes in ionic atmosphere of the aggregated BSA molecules and competitive inhibition by phosphate ions. In addition, the higher apparent binding constant at high ionic strength is explained by conformational changes of BSA from its aggregate forms into subunits. The pH effects on the afinity of interactions indicated that the binding affinity of cefazoline is higher in the neutral region than in the alkaline region. An d at high pH value, the number of binding sites decreased from 2 to 1 because of the conformational change of BSA in the alkaline region.

• Molecules and Cells
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• 제25권1호
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• pp.7-19
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• 2008

Complexins play a critical role in the control of fast synchronous neurotransmitter release. They operate by binding to trimeric SNARE complexes consisting of the vesicle protein Synaptobrevin and the plasma membrane proteins Syntaxin and SNAP-25, which are key executors of membrane fusion reactions. SNARE complex binding by Complexins is thought to stabilize and clamp the SNARE complex in a highly fusogenic state, thereby providing a pool of readily releasable synaptic vesicles that can be released quickly and synchronously in response to an action potential and the concomitant increase in intra-synaptic $Ca^{2+}$ levels. Genetic elimination of Complexins from mammalian neurons causes a strong reduction in evoked neurotransmitter release, and altered Complexin expression levels with consequent deficits in synaptic transmission were suggested to contribute to the etiology or pathogenesis of schizophrenia, Huntington's disease, depression, bipolar disorder, Parkinson's disease, Alzheimer's disease, traumatic brain injury, Wernicke's encephalopathy, and fetal alcohol syndrome. In the present review I provide a summary of available data on the role of altered Complexin expression in brain diseases. On aggregate, the available information indicates that altered Complexin expression levels are unlikely to have a causal role in the etiology of the disorders that they have been implicated in, but that they may contribute to the corresponding symptoms.

• 식품기술
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• 제9권2호
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• pp.133-139
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• 1996

최근 6할이상의 주부들이 가공식품 혹은 반가공식품을 이용하고 있으며 그 이유는 이용의 간편성, 조리가 간단하고 합리지향적인 구매행위가 가능한 점으로 꼽을 수 있다. 특히, 일본의 경우 노년인구층의 급증으로 인한 부드러운 식품소재의 이용성이 크게 늘어나고 있는 추세에서, 강하지않고 부드러운 향미 및 질감, 먹기쉬운 간편성등과 영양기능성이 강조된 제품개발이 활발히 이루어지고 있다. 따라서, 가공식품을 개발하려는 목적위에 소비자의 연령층에 대응하고, 보다 고도의 기능특성(영양성, 안전성, 경제성등)을 결합시킨 개념들이 도입되고 있다. 단백질은 가공식품의 물성을 결정하는 성분으로써 우유, 계란, 대두 및 밀가루단백질들을 이용하여 물성개량을 위한 잠정적 식품첨가물로 이용가치가 높다. 주로 구상단백질로 구성이 되어 있는 우유의 유청단백질을 특수한 처리에 의해 가용성 선상응집체(Soluble linear aggregate)로 가공한 유청단백질(Process whey protein)은 원래의 미변성 유청단백질에 비해 증강된 기능특성(표 1)을 지니고 있다. 지난 10년간 유청의 유용성에 대한 인식이 증가된 것은 물론 막기술이나, 이온 교환기술을 이용한 유청가공기술이 점진적으로 발달해왔다. 유청의 원재료는 물론이고 가공적성을 이해함으로써, 산 안전성, 겔화, 막형성, 기포형성, 유화액형성 등의 수많은 식품학적 기능특성들이 제고될 수 있다. 따라서, 식품에 응용될 수 있는 이들 기능특성들을 다듬어, 유청단백질을 특별한 목적용 제품으로 개발할 수 있도록 넓은 범위의 정보를 제공하는 것이 중요하다. 이에 유청단백질의 제조 및 가공을 제고하고, 식품에 광범위하게 응용할 수 있는 유청단백질의 다양한 식품학적 기능특성을 논의하고자 한다.

• Bulletin of the Korean Chemical Society
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• 제32권12호
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• pp.4171-4175
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• 2011

Bio-functionalized gold nanoparticles (AuNPs), which bio-specifically interact with biotin-(strept)avidin, were investigated in this study. AuNPs were functionalized with a synthetically-provided biotin-linked thiol (BLT), which was synthesized by amidation of the active ester of biotin with 2-mercaptoethylamine. The BLT-attached AuNP was bio-specific for streptavidin, making it potentially useful for biosensor applications. To test the bio-specific interactions, the colors, absorption spectra and TEM images were investigated for proteins such as streptavidin, cytochrome C, myoglobin and hemoglobin. The colors and absorption spectra changed when streptavidin was added to the BLT-attached AuNP solution. However, the color and spectra did not change when the other proteins were added to the same solution. These results show that the AuNPs provided a colloidal solution with excellent stability and highly selective absorption characteristics for streptavidin as a target molecule. Proteins were also screened in order to identify a general strategy for the use of optical biosensing proteins based on AuNPs. In addition, TEM images confirmed that streptavidin led the BLT-attached AuNPs to aggregate or precipitate.

• BMB Reports
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• 제50권7호
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• pp.345-354
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• 2017

Autophagy, a catabolic process necessary for the maintenance of intracellular homeostasis, has recently been the focus of numerous human diseases and conditions, such as aging, cancer, development, immunity, longevity, and neurodegeneration. However, the continued presence of autophagy is essential for cell survival and dysfunctional autophagy is thought to speed up the progression of neurodegeneration. The actual molecular mechanism behind the progression of dysfunctional autophagy is not yet fully understood. Emerging evidence suggests that basal autophagy is necessary for the removal of misfolded, aggregated proteins and damaged cellular organelles through lysosomal mediated degradation. Physiologically, neurodegenerative disorders are related to the accumulation of amyloid ${\beta}$ peptide and ${\alpha}-synuclein$ protein aggregation, as seen in patients with Alzheimer's disease and Parkinson's disease, respectively. Even though autophagy could impact several facets of human biology and disease, it generally functions as a clearance for toxic proteins in the brain, which contributes novel insight into the pathophysiological understanding of neurodegenerative disorders. In particular, several studies demonstrate that natural compounds or small molecule autophagy enhancer stimuli are essential in the clearance of amyloid ${\beta}$ and ${\alpha}-synuclein$ deposits. Therefore, this review briefly deliberates on the recent implications of autophagy in neurodegenerative disorder control, and emphasizes the opportunities and potential therapeutic application of applied autophagy.

• Restorative Dentistry and Endodontics
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• 제44권3호
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• pp.32.1-32.13
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• 2019

Calcium hydroxide (CH) is the gold-standard intracanal dressing for teeth subjected to traumatic avulsion. A common complication after the replantation of avulsed teeth is root resorption (RR). The current review was conducted to compare the effect of CH with that of other intracanal medications and filling materials on inflammatory RR and replacement RR (ankylosis) in replanted teeth. The PubMed and Scopus databases were searched through June 2018 using specific keywords related to the title of the present article. The materials that were compared to CH were in 2 categories: 1) mineral trioxide aggregate (MTA) and endodontic sealers as permanent filling materials for single-visit treatment, and 2) Ledermix, bisphosphonates, acetazolamide, indomethacin, gallium nitrate, and enamel matrix-derived protein (Emdogain) as intracanal medicaments for multiple-visit management of avulsed teeth prior to the final obturation. MTA can be used as a single-visit root filling material; however, there are limited data on its efficacy due to a lack of clinical trials. Ledermix and acetazolamide were comparable to CH in reducing RR. Emdogain seems to be an interesting material, but the data supporting its use as an intracanal medication remain very limited. The conclusions drawn in this study were limited by the insufficiency of clinical trials.

• International Journal of Industrial Entomology and Biomaterials
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• 제43권2호
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• pp.45-51
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• 2021

High blood cholesterol levels and oxidized cholesterol are risk factors for cardiovascular disease, which displays high annual incidence. Although studies on sericulture products, including pupae, silk protein, and blood lymph, as hypocholesterolemic substances have been reported, insufficient research in this field has been focused on silkworm larvae. Six larval extracts (Low temperature distilled water, LW; hot temperature distilled water, HW; and 30-100% ethanol, E30-E100) were prepared, and their effects on cholesterol metabolism were examined. LW most potently reduced the risk of cholesterol-related disorders. Polyphenols were highly represented in LW, corresponding with its increased antioxidant potency. The cholesterol biosynthesis enzyme, 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMGCR) was strongly inhibited by LW. Hepatocytes over-expressed LDL receptor (LDLR) after LW stimulation, promoting cholesterol elimination from plasma. LW also increased ATP binding cassette transporter 1 (ABCA1) gene expression, upregulating HDL biogenesis. In conclusion, LW exhibited strong antioxidant activity, suppressed cholesterol biosynthesis, improved LDL uptake from plasma, and upregulated HDL biosynthesis. In aggregate, these activities could reduce blood cholesterol levels and prevent cardiovascular disease.

• 대한치과재료학회지
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• 제44권2호
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• pp.187-195
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• 2017

Formocresol (FC)은 치수절단술에 일반적으로 사용되어 온 재료이지만, 재료의 독성 때문에 현재 calcium hydroxide나 mineral trioxide aggregate (MTA)가 치수절단술에 널리 사용되고 있다. 최근 레진계열 calcium silicate 제재인 Theracal LC가 치수 이장재로 개발이 되었으며, 이는 광중합을 통해 경화되기 때문에 사용이 편리해서 MTA를 적용할 수 없는 치아에 사용할 수 있다. 이번 연구의 목적은 FC, MTA 및 Theracal LC를 각각 치수절단술 후에 적용했을 경우 경조직 형성 능력과 치수반응을 비교하는 것이다. Sprague Dawley Rat의 상악 대구치 치수절단술 후 FC, MTA 및 Theracal LC를 적용하였다. 경조직 형성 여부를 확인하기 위해 Skyscan을 사용해 마이크로 컴퓨터 단층촬영(micro CT) 이미지를 획득하고, he matoxylin and e osin (H&E) 염색을 하여 조직학적 반응을 확인하였다. Dentin matrix protein-1 (DMP-1)의 발현을 확인하기 위해 면역형광 염색을 시행하였다. FC를 사용한 시편에서는 경조직 형성이 관찰되지 않았으며, 치수절단술이 시행된 인접면에 염증반응이 관찰되었고 DMP-1발현은 확인되지 않았다. MTA와 Theracal LC를 사용한 시편에서는 경조직 형성이 관찰되었고 DMP-1의 발현이 확인되었다. 결론적으로, MTA나 Theracal LC를 사용한다면 남아있는 치수의 생활력과 기능을 유지시켜 보다 좋은 치료 예후를 기대할 수 있을 것으로 사료된다.

• 공업화학
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• 제31권1호
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• pp.13-18
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• 2020

실크의 섬유 고분자 단백질인 피브로인을 사용하여 산화철 나노입자가 내포된 테라그노시스가 가능한 마이크로캡슐을 제조하였다. 열중량 분석으로 산화철의 함량은 4.28%, 자력계로는 5.11%로 측정되었다. 산화철 마이크로캡슐이 첨가된 마우스 섬유아세포 3T3 배양액에서 얻어진 세포 현탁액은 자력에 반응하여 맑게 변하고, 세포는 자석 방향으로 응집하였다. 배양접시 상단에 올려둔 네오디뮴 자석은 세포를 배양액 표면 중심으로 세포를 끌어모았다. 배양액 표면에 모인 세포들은 응집하여 72 h 이후 장축의 길이가 2 mm인 비대칭 타원체인 세포 집합체를 형성하였다. 세포집합체의 바깥층에는 세포들이 상대적으로 크고 서로 모여 치밀한 조직을 형성하였으나, 중심부는 물질전달제한으로 세포의 사멸이 진행되는 것으로 관찰되었다. 바깥층에는 산화철 마이크로캡슐이 자력의 방향으로 체인처럼 일렬로 늘어선 현상도 관찰되었다. 마이크로CT를 이용하여 세포응집체 내부의 산화철이 고루 분포하지 않고 자력 방향으로 비대칭적으로 분포하고 있음을 보였다.