Medical Photonics最新文献

Differences in the spatial distribution of actin in the left and right ventricles of functioning rabbit hearts 功能兔左、右心室肌动蛋白空间分布的差异

Medical Photonics Pub Date : 2018-03-01 DOI: 10.1016/j.medpho.2016.07.001

J. Nagwekar , D. Duggal , R. Rich , R. Fudala , I. Gryczynski , S. Raut , Z. Gryczynski , J. Borejdo

{"title":"Differences in the spatial distribution of actin in the left and right ventricles of functioning rabbit hearts","authors":"J. Nagwekar , D. Duggal , R. Rich , R. Fudala , I. Gryczynski , S. Raut , Z. Gryczynski , J. Borejdo","doi":"10.1016/j.medpho.2016.07.001","DOIUrl":"10.1016/j.medpho.2016.07.001","url":null,"abstract":"<div><p>We examined the effect of the differences in spatial arrangement of actin in contracting muscles from the left (LV) and right (RV) ventricles of rabbit heart. Spatial arrangement is a fundamental property of muscle because it reflects the interaction of individual actin molecules with myosin cross-bridges. Macroscopic parameters of contraction, such as maximum tension, speed of shortening or ATPase activity, are unlikely to reveal differences between the ventricles because they are made on whole organs containing trillions of actin and myosin molecules. Averaging the data collected from such a large assembly is likely to conceal small differences. To eliminate complications arising from the differences in the basic myocardial architecture and fiber structures of the ventricles, and to ensure that the molecular crowding influences contraction in the same way as under the <em>in-vivo</em> conditions, we collected data from isolated myofibrils <em>ex-vivo</em>. Control anisotropy experiments revealed that the orientation of actin reflected the orientation of myosin cross-bridges. The results showed that the changes in the distribution of actin induced by the interaction of actin filaments with myosin heads were demonstrated only in LVs, not in RVs. This suggests that both ventricles interact differently with myosin cross-bridges. We think that the stress induced in the thin filaments of LV causes loosening of bonds between actin monomers which leads to greater mobility of actin monomers.</p></div>","PeriodicalId":100907,"journal":{"name":"Medical Photonics","volume":"27 ","pages":"Pages 1-8"},"PeriodicalIF":0.0,"publicationDate":"2018-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.medpho.2016.07.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85735504","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Content 内容

Medical Photonics Pub Date : 2015-05-01 DOI: 10.1016/S2213-8846(15)00007-6

引用次数: 0

Fluorescence lifetime imaging by multi-dimensional time correlated single photon counting 基于多维时间相关单光子计数的荧光寿命成像

Medical Photonics Pub Date : 2015-05-01 DOI: 10.1016/j.medpho.2015.02.001

Wolfgang Becker

{"title":"Fluorescence lifetime imaging by multi-dimensional time correlated single photon counting","authors":"Wolfgang Becker","doi":"10.1016/j.medpho.2015.02.001","DOIUrl":"10.1016/j.medpho.2015.02.001","url":null,"abstract":"<div><p>Fluorescence lifetime imaging (FLIM) techniques for biological imaging have to unite several features, such as high photon efficiency, high lifetime accuracy, resolution of multi-exponential decay profiles, simultaneous recording in several wavelength intervals and optical sectioning capability. The combination of multi-dimensional time-correlated single photon counting (TCSPC) with confocal or two-photon laser scanning meets these requirements almost ideally. Multi-dimensional TCSPC is based on the excitation of the sample by a high repetition rate laser and the detection of single photons of the fluorescence signal. Each photon is characterised by its arrival time with respect to the laser pulse and the coordinates of the laser beam in the scanning area. The recording process builds up a photon distribution over these parameters. The result can be interpreted as an array of pixels, each containing a full fluorescence decay curve. More parameters can be added to the photon distribution, such as the wavelength of the photons, the time from a stimulation of the sample, or the time with respect to an additional modulation of the laser. In this review, the application of the technique will be described for the measurement of molecular environment parameters within a sample, protein interaction experiments by Förster resonance energy transfer<span> (FRET), autofluorescence measurements of cells and tissue, and in-vivo imaging of human skin and the fundus of the human eye.</span></p></div>","PeriodicalId":100907,"journal":{"name":"Medical Photonics","volume":"27 ","pages":"Pages 41-61"},"PeriodicalIF":0.0,"publicationDate":"2015-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.medpho.2015.02.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86916001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 24

Visualization of the dynamics of PSD-95 and Kir2.1 interaction by fluorescence lifetime-based resonance energy transfer imaging 基于荧光寿命的共振能量转移成像显示PSD-95和Kir2.1相互作用的动力学

Medical Photonics Pub Date : 2015-05-01 DOI: 10.1016/j.medpho.2014.11.001

Birgit Hoffmann , Nikolaj Klöcker , Klaus Benndorf , Christoph Biskup

{"title":"Visualization of the dynamics of PSD-95 and Kir2.1 interaction by fluorescence lifetime-based resonance energy transfer imaging","authors":"Birgit Hoffmann , Nikolaj Klöcker , Klaus Benndorf , Christoph Biskup","doi":"10.1016/j.medpho.2014.11.001","DOIUrl":"10.1016/j.medpho.2014.11.001","url":null,"abstract":"<div><p>Many cellular processes are orchestrated by protein–protein interactions that allow the formation of protein networks involved in subcellular compartmentalization, communication, and signalling. Postsynaptic density protein 95 (PSD-95), a member of the membrane-associated guanylate kinase protein (MAGuK) family, is a central scaffold protein of the postsynaptic density (PSD) of excitatory synapses in the mammalian central nervous system. PSD-95 serves as a matrix for targeting and accumulation of yet other PSD proteins including ion channels and receptors via its three N-terminal PDZ (PSD-95, discs large, zonula occludens-1) domains. However, the stoichiometry of PSD-95 and its binding partners in such complexes and the dynamic regulation of their interactions remain elusive. Here, we have investigated the protein–protein interaction between PSD-95 and the inward rectifier potassium channel Kir2.1, which we consider as a model for other PDZ domain based interactions at synapses. By using Förster resonance energy transfer (FRET) and fluorescence lifetime imaging microscopy (FLIM), we show that PSD-95 and Kir2.1 directly interact within clusters which are formed at the plasma membrane of culture cells. Our in vivo FRET data indicate that Kir2.1 binds to more than one PDZ domain of PSD-95, suggesting a structural model of synergistic target binding by the first two PDZ domains of the scaffold protein. We show that the cluster formation is induced by the channel whereas PSD-95 alone does not form clusters. The interaction of PSD-95 and Kir2.1 is dynamically regulated by protein kinase A (PKA) mediated phosphorylation, which is directly visualized and quantified in living cells and in real time.</p></div>","PeriodicalId":100907,"journal":{"name":"Medical Photonics","volume":"27 ","pages":"Pages 70-82"},"PeriodicalIF":0.0,"publicationDate":"2015-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.medpho.2014.11.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80637329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Fluorescence lifetime imaging (FLIM): Basic concepts and some recent developments 荧光寿命成像(FLIM):基本概念和最新进展

Medical Photonics Pub Date : 2015-05-01 DOI: 10.1016/j.medpho.2014.12.001

Klaus Suhling , Liisa M. Hirvonen , James A. Levitt , Pei-Hua Chung , Carolyn Tregidgo , Alix Le Marois , Dmitri A. Rusakov , Kaiyu Zheng , Simon Ameer-Beg , Simon Poland , Simao Coelho , Robert Henderson , Nikola Krstajic

引用次数: 198

Fingerprinting of metabolic states by NAD(P)H fluorescence lifetime spectroscopy in living cells: A review NAD(P)H荧光寿命光谱在活细胞代谢状态指纹图谱中的应用进展

Medical Photonics Pub Date : 2015-05-01 DOI: 10.1016/j.medpho.2014.06.001

J. Horilova , A. Mateasik , R. Revilla-i-Domingo , F. Raible , D. Chorvat Jr. , A. Marcek Chorvatova

{"title":"Fingerprinting of metabolic states by NAD(P)H fluorescence lifetime spectroscopy in living cells: A review","authors":"J. Horilova , A. Mateasik , R. Revilla-i-Domingo , F. Raible , D. Chorvat Jr. , A. Marcek Chorvatova","doi":"10.1016/j.medpho.2014.06.001","DOIUrl":"10.1016/j.medpho.2014.06.001","url":null,"abstract":"<div><p><span>Change in metabolic pathways is an important indicator of modifications in physiological, pathological and/or differentiation state of the cell. Its non-invasive investigation can significantly improve medical practice, namely the determination of the suspected tissue during surgery, including fast biopsy used for pre-operative tissue diagnostics, and/or resection guidance during surgical operations. Early detection of these changes is a prerequisite of fast and precise diagnostics directly in living cells and tissues and is thus crucial for the patient's survival and/or his/hers better quality of life. In this contribution, we review time-resolved fluorescence measurements of endogenous NAD(P)H in cells and tissues aimed at separation of specific metabolic pathways (glycolysis </span><em>vs.</em><span> oxidative phosphorylation<span> – OXPHOS). Other complex situations, including the presence of oxidative stress<span>, are also discussed. Current state of knowledge on non-invasive diagnostics of pathophysiological state in living cells and tissues, based on time-resolved autofluorescence, is presented.</span></span></span></p></div>","PeriodicalId":100907,"journal":{"name":"Medical Photonics","volume":"27 ","pages":"Pages 62-69"},"PeriodicalIF":0.0,"publicationDate":"2015-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.medpho.2014.06.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72779199","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 11

悪性脳腫瘍に対する光線力学的治療(Photodynamic therapy:PDT) 光线动力学治疗恶性脑肿瘤(Photodynamic therapy, PDT)

Medical Photonics Pub Date : 2013-01-01 DOI: 10.1089/lms.1986.4.2.11

秋元治朗

{"title":"悪性脳腫瘍に対する光線力学的治療(Photodynamic therapy:PDT)","authors":"秋元治朗","doi":"10.1089/lms.1986.4.2.11","DOIUrl":"https://doi.org/10.1089/lms.1986.4.2.11","url":null,"abstract":"The present studies were performed to examine the feasibility and effectiveness of intra-abdominal PDT at the paraaortic area. Vessel walls except endotheliums, striated muscles and nerves were left intact in the irradiated rats with HPD. Endotheliums at irradiated region disappeared at early stage after PDT, but regeneration of endotheliums completed by 5 days. For implanted retroperitoneal tumor models, the group with PDT obtained a significantly longer survival rate than the group without treatment. These results suggest that intra-abdominal PDT is effective as an adjuvant cancer therapy without damaging normal tissues. I.はじめに光感受性物質とレーザー照射による光線力学的治療法(以下PDT)は,肺癌をはじめ,多くの部位の悪性腫瘍に用いられているが,腹腔内病変への応用に関する報告はほとんどない,本研究ではラットを用い,大動脈周囲正常組織及び移植腫瘍へのPDTの影響とその治療効果を基礎的に検討した。 II.実験1:正常組織に対する影響の検討 i)材料と方法ラットにHPD(Photofrin I:東京医大提供) を5mg/kg静注後48時間目に傍大動脈領域にスポット径1cm2,出力80mW/cm2で628nmのAr dye laser照射を行ない,次の4グループを作成した。グループ1はHPD非投与・100J照射群,グループ2 ,3,4はHPD投与群で照射量はそれぞれ100,75,50Jとした。照射後経時的に6時間後,1,3,5,7,10,14日目に各グループ5 匹ずつ屠殺し,照射部の組織学的検討(大血管・筋肉・神経)を行なうと共に被照射血管の内皮細胞密度の変化を観察した。 ii)結果 HPD非投与のグループ1では経過中に血管壁の変性・壊死はなかったが,3日目に下大静脈の内","PeriodicalId":100907,"journal":{"name":"Medical Photonics","volume":"84 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76144707","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0