• 제목/요약/키워드: lytA

검색결과 14건 처리시간 0.03초

Carbohydrate Concentration and Composition in Source and Sink Tissues of Two Tall Fescue Genotypes

  • Song, Beom-Heon
    • 한국작물학회지
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    • 제43권4호
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    • pp.273-278
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    • 1998
  • Carbohydrate metabolism and partitioning are dependent on relationships between sources and sinks which can be affected by rates of photosynthesis and respiration. Fructan, the major form of stored carbohydrate in tall fescue (festuca arundineacea Schreb.), changes in concentration during growth and in response to the environment. Objectives of this study were i) to examine the content and the composition of carbohydrates in five tissues (mature leaf blade, immature leaf blade, leaf elongation zone, terminal meristem, and root tips) of two tall fescue genotypes, one with high yield per tiller (HYT) and one with low yield per tiller (LYT), and ii) to compare the reserved and utilized carbohydrates among above five different tissues, particularly between the leaf elongation zone and root tips. The established vegetative tillers of the HYT and LYT genotypes were grown in a controlled-environment growth chamber. Water-soluble carbohydrate (WSC) in the leaf elongation zone was about 22% of dry weight in the HYT and about 19% in the LYT genotype. The root tip also had high WSC, about 12% of dry weight in the HYT and 6% in the LYT genotype. Hexoses and sucrose were the major components of total WSC in all tissues except the leaf elongation zone. The growing tissues (sinks), i.e., the leaf elongation zone and root tip, had a high proportion of low degree of polymerization fructan, i.e., 3 to 8 hexose units.

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Inhibition of Autolysis by Lipase LipA in Streptococcus pneumoniae Sepsis

  • Kim, Gyu-Lee;Luong, Truc Thanh;Park, Sang-Sang;Lee, Seungyeop;Ha, Jung Ah;Nguyen, Cuong Thach;Ahn, Ji Hye;Park, Ki-Tae;Paik, Man-Jeong;Pyo, Suhkneung;Briles, David E.;Rhee, Dong-Kwon
    • Molecules and Cells
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    • 제40권12호
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    • pp.935-944
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    • 2017
  • More than 50% of sepsis cases are associated with pneumonia. Sepsis is caused by infiltration of bacteria into the blood via inflammation, which is triggered by the release of cell wall components following lysis. However, the regulatory mechanism of lysis during infection is not well defined. Mice were infected with Streptococcus pneumoniae D39 wild-type (WT) and lipase mutant (${\Delta}lipA$) intranasally (pneumonia model) or intraperitoneally (sepsis model), and survival rate and pneumococcal colonization were determined. LipA and autolysin (LytA) levels were determined by qPCR and western blotting. S. pneumoniae Spd_1447 in the D39 (type 2) strain was identified as a lipase (LipA). In the sepsis model, but not in the pneumonia model, mice infected with the ${\Delta}lipA$ displayed higher mortality rates than did the D39 WT-infected mice. Treatment of pneumococci with serum induced LipA expression at both the mRNA and protein levels. In the presence of serum, the ${\Delta}lipA$ displayed faster lysis rates and higher LytA expression than the WT, both in vitro and in vivo. These results indicate that a pneumococcal lipase (LipA) represses autolysis via inhibition of LytA in a sepsis model.

$pep^{27}$ and lytA in Vancomycin-Tolerant Pneumococci

  • Olivares, Alma;Trejo, Jose Olivares;Arellano-Galindo, Jose;Zuniga, Gerardo;Escalona, Gerardo;Vigueras, Juan Carlos;Marin, Paula;Xicohtencatl, Juan;Valencia, Pedro;Velazquez-Guadarrama, Norma
    • Journal of Microbiology and Biotechnology
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    • 제21권12호
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    • pp.1345-1351
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    • 2011
  • Vancomycin therapy failure due to the emergence of tolerance in pneumococci is increasing. The molecular mechanism of tolerance is not clear, but lytA and $pep^{27}$ are known to be involved. Our aim was to evaluate the expression of both genes in vancomycin-tolerant Streptococcus pneumoniae (VTSP) strains. Eleven VTSP strains from a total of 309 clinical isolates of S. pneumoniae from 1997 to 2006 were classified according to the criteria of Liu and Tomasz. All VTSP strains were evaluated for susceptibility according to CLSI criteria, serotype by the Quellung test, and clonality by PFGE. The expressions of lytA and $pep^{27}$ were analyzed in different growth phases by RT-PCR with and without vancomycin. Eighty-two percent of VTSP strains showed resistance to penicillin, and 100% were sensitive to vancomycin and cefotaxime. The most frequent serotypes of VTSP strains were 23F (4/11) and 6B (3/11). Clonal relationship was observed in only two strains. No significant changes were observed in $pep^{27}$ expression in the three phases of growth in VTSP strains with and without vancomycin. Interestingly, $pep^{27}$ expression in the stationary phase in the non-tolerant reference strain R6 was significantly higher. However, no significant differences in lytA expression were observed between VTSP and R6 strains during the phases of growth analyzed. The absence of changes in $pep^{27}$ expression in VTSP strains in the stationary phase may be related to their ability to tolerate high antibiotic concentrations, and thus, they survive and remain in the host under the antibiotic selective pressure reflected in therapeutic failure.

폐흡충(Paragonimus westermani) 감염이 흰쥐의 IgE 생성 및 비장림프구 아군분포에 미치는 영향 (Changes of IgE production, splenic helper and suppressor T lymphocytes in mice infected with Paragonimus westermani)

  • 민득영;류재숙;신명헌
    • Parasites, Hosts and Diseases
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    • 제31권3호
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    • pp.231-238
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    • 1993
  • 폐흡충 피낭유충을 BALB/c 마우스에 경구 감염시킨 후 마우스를 시기별(3일, 1주, 2주, 3주, 4주, 5주, 7주, 9주, 13주 및 23주)로 희생시켜 말초혈액내 호산구수와 혈청내 IgE 항체가를 측정하는 한편 비장 림프구를 분리하여 림프구 아군(helper T, cytotoxic / suppressor T, pan T)에 대한 단세포군 항체를 결합시켜 EPICS C fluorocytometer로 분석하였다. 폐흡충에 대한 혈청내 총 IgE 항체가는 감염 3주부터 증가되어 감염 4주에 높게 증가되었으며 13주 이후 23주까지 높은 항체가가 유지되었다. 말초혈액내 호산구수는 감염 2주 부터 증가되어 감염 9주에 $664.1/\textrm{mm}^3$으로 가장 증가 되었으며 그 이후에는 감소하여 23주에는 정상보다 약간 증가되었다. 폐흡충을 감염시키고 감염 3일, 1주, 2주, 3주, 4주, 7주 및 23주에 T 림프구 아군을 분석한 결과 L3T4 helper T 림프구와 Lyt-2 cytotoxic / suppressor T 림프구의 비율은 감염 군에서 감염 초기에 대조군에 비해 약간 감소된 경향을 보였으나 대조군과 유의한 차이를 보이지 않았다. Thy 1.2 pan T 림프구의 비율은 감염 2주와 4주에 대조군에 비해 유의하게 감소되었고(P<0.05) 7주 이후에는 대조군과 비슷하였다. 이러한 결과들로 보아 마우스의 폐흡충감염에서 특이 항원이나 마이토젠의 자극이 없이는 비장킬프구의 아군분포에 큰 변화가 없는 것으로 생각된다. 생각된다.

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Mutation of a Transposed Amino Acid Triplet Repeat Enhances Coupling of m1 Muscarinic Receptor to Activation of Phospholipase C

  • Lee, Seok-Yong;Cho, Tai-Soon
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 1996년도 춘계학술대회
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    • pp.206-206
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    • 1996
  • The C-terminus ends of the second putative transmembrane domains of both m1 and m2 muscarinic receptors contain a triplet of amino acid residues consisting of leucine (L), tyrosine (Y) and threonine (T), This triplet is repeated as LYT-LYT in m2 receptors at the interface between the second transmembrane domain and the first extracellular loop. Interestingly, however, it is repeated in a transposed fashion (LYT-TYL) in the sequence of m1 receptors. In this work we employed site-directed mutagenesis to investigate the possible significance of this unique sequence diversity for determining the distinct differential drug-receptor interaction and cellular function at m1 muscarinic receptor. Mutation of the LYTTYL sequence of m1 receptors to the corresponding m2 receptor LYTLYT sequence, however, did not result in a significant change in the binding affinity of the agonist carbachol or in the affinity of the majority of a series of receptor antagonists which are able to discriminate between wild-type m1 and m2 receptors. Surprisingly, the LYTLYT ml receptor mutant demonstrated markedly enhanced coupling to activation of phospholipase C without a change in its coupling to increased cyclic AMP formation. There was also an enhanced receptor sensitivity in transducing elevation of intracellular Ca$\^$2+/. These changes were not due to alterations in the rate of receptor. desensitization or sequestration, On the other hand, the reverse LYTLYT-LYTTYL mutation in the m2 receptor did not alter its coupling to inhibition of adenylate cyclase, but slightly enhanced its coupling to stimulation of PI hydrolysis, Our data suggest that the LYTTYL/LYTLYT sequence difference between ml and n12 muscarinic receptors is not involved in determining receptor pharmacology. On the other hand, while these differences might play a role in the modulation of muscarinic receptor coupling to PI hydrolysis, they are not important for specifying coupling of various subtypes of muscarinic receptors to different cellular signaling pathways.

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Evaluation of Urinary Antigen Test for Rapid Diagnosis of $Streptococcus$ $pneumoniae$ in Community-Acquired Pneumonia Patients

  • Yu, Mi-Young;Kim, In-Sik;Kang, Sang-Sun;Cha, Beong-Hun;Hyun, Sung-Hee
    • 대한의생명과학회지
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    • 제17권4호
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    • pp.355-361
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    • 2011
  • We evaluated the performance of the NOW $Streptococcus$ $pneumoniae$ urinary antigen test, standard culture and polymerase chain reaction for detecting $S.$ $pneumoniae$. The urinary antigen test of pneumonia patients represented sensitivity at 72% and specificity at 79%. The results of PCR were targeting for autolysin ($lyt$A), pneumolysin ($ply$), and spn9828. The $lyt$A sensitivity and specificity stood at 56% and 87% respectively while $ply$ sensitivity reported 83% and specificity was 47%, sensitivity and specificity of spn9828 stood at 83% and 73% respectively. The results of urinary antigen test and three genes were all statistically meaningful within $P$ <0.05. When the urinary antigen test of $S.$ $pneumoniae$ was positive, the three kinds of genes were also likely to be positive. According to the result of urinary antigen test, the results of PCR presented a meaningful difference ($P$ <0.05). Especially, the urinary antigen test of $S.$ $pneumoniae$ was likely to be positive ($P$ <0.05) when more than two genes were positive in PCR results.

Enhanced Coupling of $M_1$ Muscarinic Receptors to Activation of Phospholipase C upon Mutation of a Transposed Amino Acid Triplet Repeat

  • Lee, Seok-Yong;Sung, Ki-Wug;Kim, Ok-Nyu;Lee, Sang-Bok
    • The Korean Journal of Physiology and Pharmacology
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    • 제1권1호
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    • pp.19-25
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    • 1997
  • The C-terminus ends of the second putative transmembrane domains of both $M_1$ and $M_2$ muscarinic receptors contain a triplet of amino acid residues consisting of leucine (L), tyrosine (Y) and threonine (T). This triplet is repeated as LYT-TYL in $M_1$ receptors at the interface between the second transmembrane domain and the first extracellular loop. Interestingly, however, it is repeated in a transposedfashion (LYT-LYT) in the sequence of $M_2$ receptors. In our previous work, we investigated the possible significance of this unique sequence diversity for determining the distinct differential receptor function at the two receptor subtypes. However, we found mutation of the LYTTYL sequence of $M_1$ receptors to the corresponding $M_2$ receptor LYTLYT sequence demonstrated markedly enhanced the stimulation of phosphoinositide (PI) hydrolysis by carbachol without a change in its coupling to increased cyclic AMP formation. In this work, thus, the enhanced stimulation of PI hydrolysis in the LYTLYT $M_1$ receptor mutant was further investigated. The stimulation of PI hydrolysis by carbachol was enhanced in the mutant $M_1$ receptor, and this change was not due to alterations in the rate of receptor desensitization or sequestration. The observed larger response to carbachol at mutant $M_1$ receptors was also not due to an artifact resulting from selection of CHO cells which express higher levels of G-proteins or phospholipase C. Our data suggest that although the LYTTYL sequence in $M_1$ muscarinic receptors is not involved in determining receptor pharmacology, mutation of the sequence enhanced the coupling of $M_1$ receptors to the stimulation of phospholipase C.

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$M_1$$M_2$ 무스카린성 수용체에서 아미노산 Triplet Repeat의 Site-Mutagenesis가 수용체기능에 미치는 영향 (Effects of Site-Mutagenesis of an Amino Acid Triplet Repeat at $M_1$ and $M_2$ Muscarinic Receptors on Receptor Function)

  • 이석용;이상복
    • 대한약리학회지
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    • 제32권3호
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    • pp.311-321
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    • 1996
  • $M_1$$M_2$ 무스카린성 수용체의 두 번째 transmembrane domain의 C-말단에는 leucine(L), tyrosine(Y), threonine(T)로 구성된 3중체(triplet)가 있다. 이 3중체는 $M_2$ 무스카린성 수용체에서는 두 번째 transmembrane domain과 첫 번째 세포외 고리사이의 연접부위에서 LYT-LYT의 반복구조로 존재하며 $M_1$ 무스카린성 수용체에서는 흥미롭게도 LYT-TYL의 역상구조로 존재한다. 본 연구에서는 site-directed mutagenesis방법을 사용하여 이와 같은 특이한 구조적차이가 두 subtype의 수용체의 기능상 차이와 관련한 역할을 가지고 있는지를 확인하고자 하였다. $M_1$ 수용체에서는 LYTTYL서열을 $M_2$ 수용체의 서열에 해당하는 LYTLYT로 mutation시켰으며 $M_2$ 수용체에서는 LYTLYT8서열을 $M_1$ 수용체의 서열에 해당하는 LYTTYL로 mutation시켰다. 이와같은 mutation은 $M_1$$M_2$ 수용체에서 효능제 carbachol의 수용체 결합친화력에 유의한 변화를 주지 않았다. 또한 $M_1$ 수용체에서의 mutation은 cyclic AMP 증가작용에 대한 coupling은 변화시키지 않고 phosphoinositides (PI) hydrolysis 촉진작용과 세포내 $Ca^{2+}$ 농도 상승을 현저히 증가시켰다. 또한 $M_2$ 수용체에서의 mutation은 adenylate cyclase 억제에 대한 coupling은 변화시키지 않고 PI hydrolysis 촉진을 약간 증가 시켰다. 이상의 결과는 $M_1$$M_2$ 수용체에서 LYTTYL/LYTLYT 아미노산 서열의 차이는 두 수용체의 PI hydrolysis에 대한 coupling을 조절하는 역할을 하지만, 두 수용체 사이에서 ligand 결합과 신호전달계의 차이를 구분하는데 중요한 역할을 하지는 않는다.

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Epidermal Capacitance를 이용한 시판되는 치료용 샴푸의 정상적인 개 피부에 대한 가수효과 (The Comparison of Shampoos for Skin Hydration by Measurement of Epidermal Capacitance in Normal Canine Skin)

  • Oh, Tae-Ho;Jae-Hoon heong;Jang, Kwang-Ho
    • 한국임상수의학회지
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    • 제18권3호
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    • pp.206-210
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    • 2001
  • 피부질환에는 보조 치료로 다양한 치료용 샴푸가 빈번하게 적용되고 있으나 이들 샴푸의 피부수분에 미치는 영향은 일반적으로 평가되지 않고 있는 실정이다. 따라서 치료용 샴푸의 정확한 처방을 위해서는 피부의 수분을 측정하기 위한 측정법이 필요하다. 본 연구는 여러 종류의 치료용 샴푸의 피부 수분에 대한 영향을 알아보기 위해 Corneometer를 이용하여 피부에 샴푸를 적용후 수분을 측정하였다. 5두의 건강한 개를 대상으로 7가지 샴푸로 Humilac, Sebocalm, Sebolytics, Etiderm, Benzoyl peroxide, HyLyt, Zn-7 Derm를 선정하여 적용하였다. Humilac의 경우 통계학적으로 유의한 피부수분의 증가는 적용 후 17분(p<0.05), 77분(p<0.01)에 나타났으며, Benzoyl peroxide의 경우 적용 후 77분(p<0.05)에 피부의 수분이 유의하게 감소되었다. 다른 샴푸의 경우 통계학적으로 유의하지 않았으나 전반적으로 감소하는 경향을 보였으며 적용 후 77분에 최초 적용 수치에 근접하게 감소하였다. 어떤 샴푸도 피부에 부작용을 유발하지 않았다. Corneometer는 실제 임상에서 피부의 수분을 평가하는데 간단하고 유용한 측정방법을 사료된다.

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삼출성 중이염 소아의 중이액에서 폐구균의 분자적 진단 (Molecular Diagnosis of Streptococcus pneumoniae in Middle Ear Fluids from Children with Otitis Media with Effusion)

  • 변성완;김한울;윤서희;박인호;김경효
    • Pediatric Infection and Vaccine
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    • 제22권2호
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    • pp.106-112
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    • 2015
  • 목적: 장기간의 항생제 치료는 중이염 어린이 환자의 중이액으로부터 원인균이 배양되는 것을 방해한다. 본 연구는 배양 음성 중이액으로부터 분자적 진단에 의한 신속한 균 검출 가능성 여부를 확인하고자 하였다. 방법: 폐구균 lytA 유전자를 표적으로 하는 PCR과 LAMP로 민감도와 특이도를 비교 결정하고, 임상중이액에서의 폐구균 검출에 적용하였다. 결과: PCR 기법에 의한 폐구균 검출 최소한계는 약 $10^4$ 집락형성단위(CFU)이고, LAMP의 검출 최소한계는 10 CFU에서 결정되었다. 한편 두 가지 검사법 모두 Haemophilus influenzae 와 Moraxella catarrhalis 에 대해 $10^6$ CFU 이상에서도 DNA를 증폭하지 않았다. 22개의 배양음성 중이액 중에서 12개 검체가 LAMP-양성(54.5%, 12/22)으로 확인되었고, 이들 12개 LAMP-양성 검체 중, 3개의 검체만이 PCR-양성으로 확인되었다(25%, 3/12). 본 연구의 결과는 LAMP 기법의 폐구균 검출 해상력이 PCR 기법에 비교하여 4배 이상 높음을 보여준다(P<0.01). 결론: lytA -특이 LAMP 기법은, 중이액 내의 타 병원균과는 교차반응 없이 10 CFU 폐구균의 DNA를 검출할 수 있는 고해상 기술로서, 중이액 폐구균 검출 및 폐구균 백신의 보급에 따른 백신 효과 평가에 적용이 기대된다.