A 3D human neural cell culture system for modeling Alzheimer's disease

Kim, Young Hye,Choi, Se Hoon,D'Avanzo, Carla,Hebisch, Matthias,Sliwinski, Christopher,Bylykbashi, Enjana,Washicosky, Kevin J,Klee, Justin B,Brü,stle, Oliver,Tanzi, Rudolph E,Kim, Doo Yeon Nature Publishing Group 2015 NATURE PROTOCOLS -ELECTRONIC EDITION- Vol.10 No.7

Stem cell technologies have facilitated the development of human cellular disease models that can be used to study pathogenesis and test therapeutic candidates. These models hold promise for complex neurological diseases such as Alzheimer's disease (AD), because existing animal models have been unable to fully recapitulate all aspects of pathology. We recently reported the characterization of a novel 3D culture system that exhibits key events in AD pathogenesis, including extracellular aggregation of amyloid-β (Aβ) and accumulation of hyperphosphorylated tau. Here we provide instructions for the generation and analysis of 3D human neural cell cultures, including the production of genetically modified human neural progenitor cells (hNPCs) with familial AD mutations, the differentiation of the hNPCs in a 3D matrix and the analysis of AD pathogenesis. The 3D culture generation takes 1–2 d. The aggregation of Aβ is observed after 6 weeks of differentiation, followed by robust tau pathology after 10–14 weeks.

Amplicilin biosynthesis by immobilized enzyme

Kim, Young-Sik,Ryu, Dewy-D.Y. The Pharmaceutical Society of Korea 1980 Archives of Pharmacal Research Vol.3 No.1

Ampliciline was synthesized from 6-amino-pencillanic acid (6-APA) and D-.alpha. phenylglycine methyl ester by using amplicilin synthesizing enzyme from Peudomonas melanogenum (IAM 1655). The whole cell enzyme was immobilized by entrapping it in the polyacrylamide gel lattices. The polymer used in the enzyme entrapment was made from 150 mg per ml of acrylamide monomer and 8 mg per ml of N, N'-methylenebisacrylamide. About 200 mg/whole cell enzyme was mixed in the polymer for entrapment. The maximal activity retention after immobilization was 56%. The optimal pH values for the whole cell enzyme and the immobilized whole cell enzyme were 6.0 and 5.9, respectively. The optimal temperature for the enzyme activity were the same for both type of preparations. The enzyme stabilities against pH and heat increased for immobilized whole cell enzyme. Immobilized cell was more stable especially in the acidic condition while both type were found to be very suceptible to thermal inactivation at a temperature above 4.deg.C. The kinetic constants obtained from Lineweaver-Burk plot based on two substate reaction mechanism showed somewhat higher value for immobilized whole cell enzyme as compared to the whole cell enzyme : the Km value for 6-APA were 7.0 mM and 12.5 mM while Km values for phenylglycine methyl ester were 4.5 mM and 8.2 mM, respectively. Using the immobilized whole cell enzyme packed in a column reactor, the productivity of ampiciline was studied by varying the flow rate of substrate solution. At the space velocity, SV, 0.14 hr$^{-1}$ the conversion was 45%. Operational stability found in terms of half life was 30 hr at SV = 0.2 hr.

Genetic Status of Asiatic Black Bear (Ursus thibetanus) Reintroduced into South Korea Based on Mitochondrial DNA and Microsatellite Loci Analysis.

Kim, Yung-Kun,Hong, Yoon-Jee,Min, Mi-Sook,Kim, Kyung Seok,Kim, Young-Jun,Voloshina, Inna,Myslenkov, Alexander,Smith, Gavin J D,Cuong, Nguyen Dinh,Tho, Huynh Huu,Han, Sang-Hoon,Yang, Doo-Ha,Kim, Chang- published for the Association by Oxford University 2011 The Journal of heredity Vol.102 No.2

<P>The Asiatic black bear is one of the most endangered mammals in South Korea owing to population declines resulting from human exploitation and habitat fragmentation. To restore the black bear population in South Korea, 27 bear cubs from North Korea and Russian Far East (Primorsky Krai) were imported and released into Jirisan National Park, a reservoir of the largest wild population in South Korea, in 2004. To monitor the success of this reintroduction, the genetic diversity and population structure of the reintroduced black bears were measured using both mitochondrial and nuclear DNA markers. Mitochondrial D-loop region DNA sequences (615 bp) of 43 Japanese black bears from previous study and 14 Southeast Asian black bears in this study were employed to obtain phylogenetic inference of the reintroduced black bears. The mitochondrial phylogeny indicated Asiatic black bear populations from Russian Far East and North Korea form a single evolutionary unit distinct from populations from Japan and Southeast Asia. Mean expected heterozygosity (H(E)) across 16 microsatellite loci was 0.648 for Russian and 0.676 for North Korean populations. There was a moderate but significant level of microsatellite differentiation (F(ST) = 0.063) between black bears from the 2 source areas. In addition, genetic evidences revealed that 2 populations are represented as diverging groups, with lingering genetic admixture among individuals of 2 source populations. Relatedness analysis based on genetic markers indicated several discrepancies with the pedigree records. Implication of the phylogenetic and genetic evidences on long-term management of Asiatic black bears in South Korea is discussed.</P>

HBV : PE-028 ; Prevalence of hepatitis A, B, C and D viruses among patients with acute hepatitis in Mongolia

( O. Baatarkhuu ),( Do Young Kim ),( B Bayarmagna ),( N Khorolsuren Baigal ),( R Ouyngerel ),( D Enkhsaikhan ),( Y Dahgwahdorj ),( Sang Hoon Ahn ),( Kwang Hyub Han ) 대한간학회 2012 춘·추계 학술대회 (KASL) Vol.2012 No.-

Background and Aims: Mongolia is an endemic area of acute and chronic viral hepatitis. To determine the prevalence of HAV, HBV, HCV and HDV infections among patients with acute hepatitis in Mongolia during outbreaks. Methods: A total of 624 patients (353 males and 271 females; age, 18.6±8.1 years; range 2-66 years) who were clinically diagnosed with acute hepatitis during outbreak from October 2011 to March 2012 in Ulaanbaatar, Mongolia have been studied. The prevalence of hepatitis virus infections was determined by testing of serum for the IgM class of antibodies against HAV, HBV, HCV, HDV, and HBsAg. Results: Acute hepatitis A (AHA) (IgM anti-HAV positive) was diagnosed in 284 patients (45.5%). Acute hepatitis B (AHB) (IgM anti-HBc positive) was diagnosed in 191 patients (30.6%) and 22 patients (3.5%) was diagnosed as co-infection of B and D. Acute hepatitis C (AHC) (IgM anti-HCV positive) was diagnosed in 33 patients (5.3%). There were 52 (8.3%) HBV carriers who had detectable HBsAg and anti-HDV but who were negative for both IgM anti-HAV and IgM anti-HBc, suggesting that they acquired type D acute hepatitis due to superinfection of HDV on a background of chronic HBV infection. Forty-two (6.5%) patients were found to be infected by various combinations of dual viruses such as HAV/HBV (2.8%), HAV/HDV (0.6%), HBV/HCV (2.5%), and HCV/HDV (0.6%). AHA was the most prevalent in subjects aged 1-19 years, AHB and HBV+HDV superinfection were the first and second most prevalent in the age group of 20-29 years, and AHC was the most common type in 40-49 years. Conclusion: Dual hepatitis viral infection was detected in approximately 6.5% among patients with acute hepatitis in Mongolia.

HBV : PE-028 ; Prevalence of hepatitis A, B, C and D viruses among patients with acute hepatitis in Mongolia

( O Baatarkhuu ),( Do Young Kim ),( B Bayarmagnai ),( N Khorolsuren ),( B Baigal ),( R Ouyngerel ),( D Enkhsaikhan ),( Y Dahgwahdorj ),( Sang Hoon Ahn ),( Kwang Hyub Han ) 대한간학회 2012 춘·추계 학술대회 (KASL) Vol.2012 No.1

Background and Aims: Mongolia is an endemic area of acute and chronic viral hepatitis. To determine the prevalence of HAV, HBV, HCV and HDV infections among patients with acute hepatitis in Mongolia during outbreaks. Methods: A total of 624 patients (353 males and 271 females; age, 18.6±8.1 years; range 2-66 years) who were clinically diagnosed with acute hepatitis during outbreak from October 2011 to March 2012 in Ulaanbaatar, Mongolia have been studied. The prevalence of hepatitis virus infections was determined by testing of serum for the IgM class of antibodies against HAV, HBV, HCV, HDV, and HBsAg. Results: Acute hepatitis A (AHA) (IgM anti-HAV positive) was diagnosed in 284 patients (45.5%). Acute hepatitis B (AHB) (IgM anti-HBc positive) was diagnosed in 191 patients (30.6%) and 22 patients (3.5%) was diagnosed as co-infection of B and D. Acute hepatitis C (AHC) (IgM anti-HCV positive) was diagnosed in 33 patients (5.3%). There were 52 (8.3%) HBV carriers who had detectable HBsAg and anti-HDV but who were negative for both IgM anti-HAV and IgM anti-HBc, suggesting that they acquired type D acute hepatitis due to superinfection of HDV on a background of chronic HBV infection. Forty-two (6.5%) patients were found to be infected by various combinations of dual viruses such as HAV/HBV (2.8%), HAV/HDV (0.6%), HBV/HCV (2.5%), and HCV/HDV (0.6%). AHA was the most prevalent in subjects aged 1-19 years, AHB and HBV+HDV superinfection were the first and second most prevalent in the age group of 20-29 years, and AHC was the most common type in 40-49 years. Conclusion: Dual hepatitis viral infection was detected in approximately 6.5% among patients with acute hepatitis in Mongolia.

세탁용 가성소다 관장에 의한 사망 사례 보고

김유희,최영식,권태정 大韓法醫學會 2000 대한법의학회지 Vol.24 No.1

The principal manifestation of poisoning induced by the alkaline substance is a corrosive effects in tissues. The alkalies combine with protein and fat of the tissue, causing deep penetrating injury and liquefactive necrosis of the organs. Liquid lye is the most frequently ingested form of corrosive agents and causes most of the deaths associated with corrosive agent ingestion. We have experienced 5 fatal cases which were accidentally administered liquid lye as soap-saline enema in the hospital during 30 days. the 3 cases of them were autopsied at this institute. At autopsy, the digestive tract including rectum, colon and small intestine revealed hemorrhagic necrosis with multiple area of perforation. Because these were the first proved cases that the liquid lye was used as enema solution, we report here.

Optical Properties Related to Two-Dimensional Electron Gas at AlGaN/GaN Heterostructures

Young Shin Park,Chang Mo Park,D. J. Fu,Ho Sang Lee,Hong Jin Kim,J. E. Oh,Jong Ho Na,Sung Woo Choi,T. W. Kang 한국물리학회 2003 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.43 No.51

We report photoluminescence (PL) spectra related to a two-dimensional electron gas (2DEG) conned at an AlGaN/GaN heterointerface. The 2DEG related the PL has been identied by measuring PL of the structure as functions of the light intensity and the temperature and by comparing the results with those obtained for GaN exposed via etching. The PL peak related to recombination between the two-dimensional electron gas and photoexcited holes is located at 3.436 eV at 15 K, which is 28 meV below the bound exciton (D0X) emission in GaN. The activation energy is about 10.8 meV.

40Gbps급 (4X10) VCSEL Array 구동기

김형수,정성재,김두근,이희현,최영완 중앙대학교정보통신연구소 2001 정보통신연구소논문집 Vol.3 No.2

본 논문에서는 VCSEL(Vertical Cavity Surface Emiting Laser)을 채널당 1Gbps로 동작시키고, DC Bias 전류 변화폭과 RF Modulation 전류 변화폭의 조절이 가능한 구동 드라이버를 현대 0.35㎛ 2-Poly 4-Matel CMOS공정을 이용하여 설계했다. In this paper, we present a 40 Gb/s VCSEL driver (4 x 10 channels, 1 Gbps/ch) designed and fabricated in HYNIX 0.35㎛ 2-poly 4-matel CMOS technology. The CMOS driver designed for a free space optical interconnect system is consisted of two NMOS for driving a VCSEL and protection circuit rejecting influence of electro-static discharge (ESD) or unexpected input signal with several tens voltage amplitude. Two NMOS with CMOS channel length of 0.4㎛ and width of 100 ㎛ are used for adjusting dc bias current from 0 to 27 mA and ac modulation current from 0 to 13.8 mA. Protection circuit is made of two diodes. The purpose of the protection circuit is to permit the input modulation voltage range only from 5 to 5 V.

2 단 연속식 발효 방식에 의한 솔비톨로 부터의 솔보즈 생산 : 조업 조건의 최적화 Optimization of Operating Condition

김영걸,구윤모,유두영 한국화학공학회 1980 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.18 No.5

Glucose를 starting material로 하는 vitamin C 생산에 있어서 중요한 중간 물질인 sorbose의 2단 연속식 발효 방식에 의한 생산에 대하여 연구하였다. Sorbitol의 탈수소 반응에 의한 sorbose의 생성은 화학적인 방법으로도 그 진행이 가능하지만 L-. D-형의 sorbose racemate가 생기기 때문에 그 수율면에서 미생물에 의한 발효에 뒤지고 있다. 회분식 발효에 있어서 기질 농도가 20% 일 때 90%의 전화율과 19mmole/ℓ/hr의 생산율을 얻었다. 회분식 실험에 의하여 sorbose의 생산은 발효액 중의 미생물 농도에 비례함을 알았고 미생물 농도를 증가시키기 위하여 연속식 발효 방식, 특히 여과장치를 갖춘 2단 연속식 발효 방식을 사용하여 생산율 증가를 시도하였다. 온도 29℃ pH 4.6, 기질농도 20% 등 최적 발효조건을 유지하며 90%의 전화율에서 45mmole/ℓ/hr의 생산율을 얻을 수 있었으며 이것은 회분식 최대 생산율의 2배 이상에 해당하는 값이다. Using a two-stage continuous culture system, the parameters that affect the productivity of sorbose were studied and the operating conditions which correspond to the maximal productivity of sorbose were determind. The maximum specific growth rate of Acetobacter surboxydans strain employed was 0.31hr and its optimal growth pH was determined as 4. 6. The maximum productivity of sorbose obtained employing a batch culture system was 19mmole/liter/hr at 90% conversion level. The enzymatic conversion of sorbose was found to be proportional to the cell concentration, and the cell concentration in the second-stage continuous bioreactor was increased by using a filter system installed at the effluent line. Under the optimal operating conditions, 29℃, pH 4.6, and sorbitol concentration 20%, the two-stage continuous fermentation system yielded the productivity of 45mmole sorbose/liter/hr while maintaining 90% or higher level of conversion, indicating that a significant improvement in the sorbose productivity could be achieved by employing the two-stage continous bioreactor system combined with the cell enrichment technique.

폐결핵환자의 최근 단기화학요법에 대한 임상적 고찰

김재원,정혜영,박효숙,조동일,유재인,유남수,박윤기,배성근 최신의학사 1981 最新醫學 Vol.24 No.1