• 제목/요약/키워드: PIP$_2$

검색결과 121건 처리시간 0.029초

The Clinical Implications of Poly Implant Proth$\grave{e}$se Breast Implants: An Overview

  • Wazir, Umar;Kasem, Abdul;Mokbel, Kefah
    • Archives of Plastic Surgery
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    • 제42권1호
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    • pp.4-10
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    • 2015
  • Mammary implants marketed by Poly Implant Proth$\grave{e}$se (PIP) were found to contain industrial grade silicone and this caused heightened anxiety and extensive publicity regarding their safety in humans. These implants were used in a large number of patients worldwide for augmentation or breast reconstruction. We reviewed articles identified by searches of Medline, PubMed, Embase, and Google Scholar databases up to May 2014 using the terms: "PIP", "Poly Implant Proth$\grave{e}$se", "breast implants" and "augmentation mammoplasty" "siloxanes" or "silicone". In addition the websites of regulating bodies in Europe, USA, and Australia were searched for reports related to PIP mammary implants. PIP mammary implants are more likely to rupture than other implants and can cause adverse effects in the short to the medium term related to the symptoms of rupture such as pain, lumps in the breast and axilla and anxiety. Based on peer-reviewed published studies we have calculated an overall rupture rate of 14.5% (383/2,635) for PIP implants. However, there is no evidence that PIP implant rupture causes long-term adverse health effects in humans so far. Silicone lymphadenopathy represents a foreign body reaction and should be treated conservatively. The long-term adverse effects usually arise from inappropriate extensive surgery, such as axillary lymph node dissection or extensive resection of breast tissue due to silicone leakage.

Regulation of Adenosine-activated GIRK Channels by Gq-coupled Receptors in Mouse Atrial Myocytes

  • Cho, Ha-Na
    • The Korean Journal of Physiology and Pharmacology
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    • 제14권3호
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    • pp.145-150
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    • 2010
  • Adenosine (Ado) is an important mediator of the endogenous defense against ischemia-induced injury in the heart. The action of Ado is mediated by activation of G protein-gated inwardly rectifying $K^+$ (GIRK) channels. In turn, GIRK channels are inhibited by reducing phosphatidylinositol 4,5-bisphosphate ($PIP_2$) through Gq protein-coupled receptors (GqPCRs). We previously found that GIRK channels activated by acetylcholine, a muscarinic M2 acetylcholine receptor agonist, are inhibited by GqPCRs in a receptor-specific manner. However, it is not known whether GIRK channels activated by Ado signaling are also regulated by GqPCRs. Presently, this was investigated in mouse atrial myocytes using the patch clamp technique. GIRK channels were activated by $100\;{\mu}M$ Ado. When Ado was repetitively applied at intervals of 5~6 min, the amplitude of second Ado-activated GIRK currents ($I_{K(Ado)}$) was $88.3{\pm}3.7%$ of the first $I_{K(Ado)}$ in the control. Pretreatment of atrial myocytes with phenylephrine, endothelin-1, or bradykinin prior to a second application of Ado reduced the amplitude of the second $I_{K(Ado)}$ to $25.5{\pm}11.6%$, $30.5{\pm}5.6%$, and $96.0{\pm}2.7%$, respectively. The potency of $I_{K(Ado)}$ inhibition by GqPCRs was different with that observed in acetylcholine-activated GIRK currents ($I_{K(ACh)}$) (endothelin-1>phenylephrine>bradykinin). $I_{K(Ado)}$ was almost completely inhibited by $500\;{\mu}M$ of the $PIP_2$ scavenger neomycin, suggesting low $PIP_2$ affinity of $I_{K(Ado)}$. Taken together, these results suggest that the crosstalk between GqPCRs and the Ado-induced signaling pathway is receptor-specific. The differential change in $PIP_2$ affinity of GIRK channels activated by Ado and ACh may underlie, at least in part, their differential responses to GqPCR agonists.

NMR Structure of Syndecan-4L reveals structural requirement for PKC signalling

  • Koo, Bon-Kyoung;Joon Shin;Oh, Eok-Soo;Lee, Weontae
    • 한국자기공명학회:학술대회논문집
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    • 한국자기공명학회 2002년도 International Symposium on Magnetic Resonance
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    • pp.90-90
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    • 2002
  • Syndecans, transmembrane heparan sulfate proteoglycans, are coreceptors with integrin in cell adhesion process. It forms a ternary signaling complex with protein kinase C and phosphatidylinositol 4,5 bisphosphate (PIP2) for integrin signaling. NMR data indicates that cytoplasmic domain of syndecan-4 (4L) undergoes a conformational transition in the presence of PIP2, forming oligomeric conformation. The structure based on NMR data demonstrated that syndecan-4L itself forms a compact intertwined symmetric dimer with an unusual clamp shape for residues Leu$^{186}$ -Ala$^{195}$ . The molecular surface of the syndecan-4L dimer is highly positively charged. In addition, no inter-subunit NOEs in membrane proximal amino acid resides (Cl region) has been observed, demonstrating that the Cl region is mostly unstructured in syndecan-4L dimmer. However, the complex structure in the presence of PIP2 induced a high order multimeric conformation in solution. In addition, phosphorylation of cytoplasmic domain induces conformational change of syndecan-4, resulting inhibition of PKC signaling. The NMR structural data strongly suggest that PIP2 promotes oligomerization of syndecan-4 cytoplasmic domain for PKC activation and further induces structural reorganization of syndecan for mediating signaling network in cell adhesion procedure.

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Expression of CsRCI2s by NaCl stress reduces water and sodium ion permeation through CsPIP2;1 in Camelina sativa L.

  • Kim, Hyun-Sung;Lim, Hyun-Gyu;Ahn, Sung-Ju
    • 한국작물학회:학술대회논문집
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    • 한국작물학회 2017년도 9th Asian Crop Science Association conference
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    • pp.194-194
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    • 2017
  • Camelina (Camelina sativa L.) is a potential bio-energy crop that has short life cycle about 90 days and contains high amount of unsaturated fatty acid which is adequate to bio-diesel production. Enhancing environmental stress tolerance is a main issue to increase not only crop productivity but also big mass production. CsRCI2s (Rare Cold Inducible 2) are cold and salt stress related protein that localized at plasma membrane (PM) and assume to be membrane potential regulation factor. These proteins can be divide into C-terminal tail (CsRCI2D/E/F/G) or no-tail group (CsRCI2A/B/C/H). However, function of CsRCI2s are less understood. In this study, physiological responses and functional characterization of CsRCI2s of Camelina under salt stress were analyzed. Full-length CsRCI2s (A/B/E/F) and CsPIP2;1 sequences were confirmed from Camelina genome browser. Physiological investigations were carried out using one- or four-week-old Camelina under NaCl stress with dose and time dependent manner. Transcriptional changes of CsRCI2A/B/E/F and CsPIP2;1 were determined using qRT-PCR in one-week-old Camelina seedlings treated with NaCl. Translational changes of CsRCI2E and CsPIP2;1 were confirmed with western-blot using the antibodies. Water transport activity and membrane potential measurement were observed by cRNA injected Xenopus laevis oocyte. As results, root growth rate and physiological parameters such as stomatal conductance, chlorophyll fluorescence, and electrolyte leakage showed significant inhibition in 100 and 150 mM NaCl. Transcriptional level of CsPIP2;1 did not changed but CsRCI2s were significantly increased by NaCl concentration, however, no-tail type CsRCI2A and CsRCI2B increased earlier than tail type CsRCI2E and CsRCI2F. Translational changes of CsPIP2;1 was constitutively maintained under NaCl stress. But, accumulation of CsRCI2E significantly increased by NaCl stress. CsPIP2;1 and CsRCI2A/B/E/F co-expressed Xenopus laevis oocyte showed decreased water transport activity as 61.84, 60.30, 62.91 and 76.51 % at CsRCI2A, CsRCI2B, CsRCI2E and CsRCI2F co-expression when compare with single expression of CsPIP2;1, respectively. Moreover, oocyte membrane potential was significantly hyperpolarized by co-expression of CsRCI2s. However, higher hyperpolarized level was observed in tail-type CsRCI2E and CsRCI2F than others, especially, CsRCI2E showed highest level. It means transport of $Na^+$ ion into cell is negatively regulated by expression of CsRCI2s, and, function of C-terminal tail is might be related with $Na^+$ ion influx. In conclusion, accumulation of NaCl-induced CsRCI2 proteins are related with $Na^+$ ion exclusion and prevent water loss by CsPIP2;1 under NaCl stress.

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석류 추출물의 간암세포 성장 억제 및 항산화 활성 효과 (The Effects of Pomegranate Extracts on the Growth Inhibition against HepG-2 Liver Cancer Cells and Antioxidant Activities)

  • 박경태;김두운;신태선;심선엽;김문용;전순실
    • 한국조리학회지
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    • 제15권1호
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    • pp.120-127
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    • 2009
  • 석류씨, 석류 외피 분말 추출물 및 석류 과즙(주스 1과 주스 2) 추출물을 DPPH 라디컬 소거활동에 HepG-2 세포 그리고 항산화 활동에 추출물의 성장억제를 측정하였다. 높은 농도를 가진 모든 샘플은 HepG-2 세포에 대하여 성장 억제를 보였으며, 2,500 ppm의 처리구에서는 2회 감압 농축한 과즙 농축물(43%)>석류씨 분말 추출물(42%)>석류외피 분말 추출물(38%)>1회 감압 농축한 과즙 농축물(29%) 순으로 나타났다. BHT와 시료들 모두 농도 의존적으로 DPPH 라티칼 소거 활성이 증가하는 경향을 보였고, 12.5 ppm의 처리구에서 석류외피 분말 추출물(60.8%)>BHT(29.9%)>석류씨 분말 추출물(16.2%)>2회 감압 농축한 과즙 농축물(15.1%)>1회 감압 농축한 과즙 농축물(12.6%)의 순으로 나타났으며, 25, 50, 100 및 200 ppm처리구에서는 석류외피 분말 추출물(81.9$\sim$85.3%)>석류씨 분말 추출물(33.4$\sim$83.0%)>BHT(31.3$\sim$47.8%)>2회 감압 농축한 과즙 농축물(15.4$\sim$36.8%)>1회 갑압 농축한 과즙 농축물(13.4$\sim$36.1 %)의 순으로 나타났다.

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무기염을 이용한 다공성 PVDF 고분자막의 친수화를 통한 초저압용 나노여과막 제조 연구 (Studies on the Preparation of Nanofiltration Membrane for Ultra-low Pressure Application through Hydrophilization of Porous PVDF Membrane Using Inorganic Salts)

  • 박찬종;조은혜;임지원;정성일
    • 멤브레인
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    • 제24권1호
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    • pp.69-77
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    • 2014
  • 초저압용 나노여과 중공사 복합막을 제조하기 위하여 poly(vinylidene fluoride) (PVDF) 소수성 중공사막 표면에 무기염인 $K_2Cr_2OH$$KMnO_4$ 수용액으로 친수화 처리를 하였으며, 처리된 막 표면 위에 piperazine (PIP)과 trimesoyl chloride (TMC)로 계면 중합하여 복합막을 제조하였다. NaCl, $CaSO_4$, $MgCl_2$ 100 ppm 용액 및 300 ppm의 NaCl과 $CaSO_4$ 혼합용액을 이용하여 코팅물질의 농도, 코팅시간 및 건조시간에 따른 복합막의 투과특성을 알아보았다. 실험 결과 친수화 물질로는 $K_2Cr_2OH$을 사용하였을 때 더 높은 배제율을 보였으며, 친수화 시간이 길어질수록 투과도는 향상되고 배제율은 감소하는 경향을 나타내었다. 또한 촉매인 triethyl amine (TEA)과 sodium lauryl sulfate (SLS)의 농도가 높을수록 투과도는 감소하고, 염제거율은 증가하였다. 최적 조건으로는 $K_2Cr_2OH$으로 10분 동안 친수화 시킨 PVDF 중공사막 위에 PIP 2 wt% 용액(PIP 함량 대비 Triethyl amine (TEA) 7 wt%, SLS 20 wt% 혼합용액)과 TMC 0.1 wt%를 이용하여 계면중합한 것으로 공급액 NaCl 100 ppm에 대해서는 투과도 40 LMH, 제거율 50%이었고, $CaSO_4$ 100 ppm에 대해서는 투과도 48 LMH, 제거율 55%를 나타내었다.

화학침착법과 고분자함침 열분해법의 복합공정으로 제조한 SiCf/SiC 복합체의 제조 공정에 따른 파괴거동 (Fracture Behaviors of SiCf/SiC Composites Prepared by Hybrid Processes of CVI and PIP)

  • 박지연;한장원;김대종;김원주;이세훈
    • 한국세라믹학회지
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    • 제51권5호
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    • pp.430-434
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    • 2014
  • $SiC_f$/SiC composites were prepared using the hybrid process of chemical vapor infiltration (CVI) and polymer impregnation and pyrolysis (PIP). Before the application of PIP, partially matrix-filled preform composites with different densities were fabricated by control of chemical vapor infiltration time and temperature. The changes of the final density of the $SiC_f$/SiC composites had a tendency similar to that of preform composites partially filled by CVI. Composites with lower density after the CVI process had a larger increment of density during the PIP process. Three types of microstructures were observed on the fractured surface of the composite: 1) well pulled-out fibers and lower density, 2) slightly pulled-out fibers and higher density, and 3) only bulk SiC. The different fractions and distributions of the microstructures could have an effect on the mechanical properties of the composites. In this study, $SiC_f$/SiC composites prepared using a hybrid process of CVI and PIP had density values in the range of $1.05{\sim}1.44g/cm^3$, tensile strength values in the range of 76.4 ~ 130.7 MPa, and fracture toughness values in the range of $11.2{\sim}13.5MPa{\cdot}m^{1/2}$.

High Security FeRAM-Based EPC C1G2 UHF (860 MHz-960 MHz) Passive RFID Tag Chip

  • Kang, Hee-Bok;Hong, Suk-Kyoung;Song, Yong-Wook;Sung, Man-Young;Choi, Bok-Gil;Chung, Jin-Yong;Lee, Jong-Wook
    • ETRI Journal
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    • 제30권6호
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    • pp.826-832
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    • 2008
  • The metal-ferroelectric-metal (MFM) capacitor in the ferroelectric random access memory (FeRAM) embedded RFID chip is used in both the memory cell region and the peripheral analog and digital circuit area for capacitance parameter control. The capacitance value of the MFM capacitor is about 30 times larger than that of conventional capacitors, such as the poly-insulator-poly (PIP) capacitor and the metal-insulator-metal (MIM) capacitor. An MFM capacitor directly stacked over the analog and memory circuit region can share the layout area with the circuit region; thus, the chip size can be reduced by about 60%. The energy transformation efficiency using the MFM scheme is higher than that of the PIP scheme in RFID chips. The radio frequency operational signal properties using circuits with MFM capacitors are almost the same as or better than with PIP, MIM, and MOS capacitors. For the default value specification requirement, the default set cell is designed with an additional dummy cell.

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Poly(vinylbenzyl ammonium salt)를 이용한 Pore-filled 이온교환막의 제조 (Preparation of Pore-filled Ion-exchange Membranes using Poly(vinylbenzyl ammoninum salt))

  • 변홍식
    • 멤브레인
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    • 제11권3호
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    • pp.109-115
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    • 2001
  • Polypropylene(PP)을 지지막으로 하여 in-situ 가교결합(cross-linking)방식을 이용한 pore-filled 이온교환막을 제조하였다. 다공성 PP막의 기공에 poly(vinylbenzyl chloride)(PVBCI)과 piperazine(PIP), 또는 1,4-diaminobicyclo [2,2,2]octane(DABCO)을 dimethylforamid(DMF)에 녹인 용액을 채워서 겔화시킨 후, 남아있는 chloromethyl 그룹에 trimethylamine을 이용하여 양이온인 암모니움 site를 형성시키면 pore-filled 음이온교환막이 형성된다. 이와 같은 2단계의 제조방식으로 제조된 pore-filled 분리막은 크기의 변화가 없이 안정되며, PVBCI의 농도와 가교제의 농도로써 고분자-겔의 함량(mass gain, MG)과 가교도가 간단하게 조절되는 것을 보여주었다. 특히 아주 낮은 압력(100 kPa)에서의 높은 수투과도(7.9kg/$m^2$hr, 지지막은 PP3, 73%의 MG, 10%의 가교도, PIP 가교제사용)는 연수용 분리막으로 충분히 활용될 수 있음을 보여준다.

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Pathogen-Imprinted Polymer Film Integrated probe/Ti3C2Tx MXenes Electrochemical Sensor for Highly Sensitive Determination of Listeria Monocytogenes

  • Xiaohua, Jiang;Zhiwen, Lv;Wenjie, Ding;Ying, Zhang;Feng, Lin
    • Journal of Electrochemical Science and Technology
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    • 제13권4호
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    • pp.431-437
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    • 2022
  • As one of the most hazardous and deadliest pathogens, Listeria monocytogenes (LM) posed various serious diseases to the human being, thus designing effective strategy for its detection is of great significance. In this work, by preparing Ti3C2Tx MXenes nanoribbon (Ti3C2TxR) as carrier and selecting thionine (Th) acted simultaneously as signal probe and functional monomer, a LM pathogen-imprinted polymers (PIP) integrated probe electrochemical sensor was design to monitor LM for the first time, that was carried out through the electropolymerization of Th on the Ti3C2TxR/GCE surface in the existence of LM. Upon eluting the templates from the LM imprinted cavities, the fabricated PIP/Ti3C2TxR/GCE sensor can rebound LM cells effectively. By recording the peak current of Th as the response signal, it can be weakened when LM cell was re-bound to the LM imprinted cavity on PIP/Ti3C2TxR/GCE, and the absolute values of peak current change increase with the increasement of LM concentrations. After optimizing three key parameters, a considerable low analytical limit (2 CFU mL-1) and wide linearity (10-108 CFU mL-1) for LM were achieved. In addition, the experiments demonstrated that the PIP/Ti3C2TxR sensor offers satisfactory selectivity, reproducibility and stability.