Abstract:
:The fluorescence ratio imaging technique is currently applied in vitro and in vivo to measure intracellular as well as extracellular pH. To date, however, no effort has been made to assess the technique's ability to detect spatial pH gradients in vitro or in vivo, where pH gradients are known to exist, in a controlled environment using an independent pH measurement system. We present here both in vitro calibration and in vivo application of fluorescence ratio imaging to measure pH gradients in a biologically useful pH range (6.2-7.8). Isoelectric focusing in short polyacrylamide gels was used to establish spatial pH gradients ranging from approximately 0.2 to 0.5 pH units/mm. The pH gradients were measured independently with fluorescence ratio imaging microscopy (FRIM) and a surface electrode. The average difference between measurements using the two techniques was 0.043 pH units for 10-mm polyacrylamide gels (100 measurements in 12 gels) and 0.046 pH units for 20-mm gels (114 measurements in 15 gels). These gel studies have demonstrated the use of isoelectric focusing to calibrate FRIM for measuring spatial pH gradients characteristic of those found in tumors in vivo. The feasibility of FRIM was tested in vivo by measuring pH in a solid tumor (VX2 carcinoma) and surrounding normal granulation tissue grown in the rabbit ear chamber. The average (+/- SD) pH of normal and neoplastic regions of the composite tissue was 7.18 +/- 0.11 (n = 158) and 6.75 +/- 0.10 (n = 191), respectively. The pH varied by an average of approximately 0.6 pH units over the 5-mm diameter of the chamber and showed a sharp difference at the interface of the two tissue types. These pH values are consistent with the current pH data on normal and neoplastic tissues. Thus FRIM should permit noninvasive in vivo evaluation of new pH-modifying agents and, in combination with other optical techniques, should offer novel mechanistic information about tumor pathophysiology.
journal_name
Microvasc Resjournal_title
Microvascular researchauthors
Martin GR,Jain RKdoi
10.1006/mvre.1993.1048subject
Has Abstractpub_date
1993-09-01 00:00:00pages
216-30issue
2eissn
0026-2862issn
1095-9319pii
S0026-2862(83)71048-4journal_volume
46pub_type
杂志文章abstract::Metabolic syndrome (MetS) is a combination of clinical disorders that together increase the risk for cardiovascular disease and diabetes. SHRSP.Z-Lepr(fa)/IzmDmcr (SHRSP.ZF) rats with MetS show impaired nitric oxide-mediated relaxation in coronary and mesenteric arteries, and angiotensin II receptor type 1 blockers pr...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/j.mvr.2013.04.001
更新日期:2013-07-01 00:00:00
abstract::Methods currently available for the examination of the retinal vasculature of laboratory animals have significant drawbacks. Fluorescein angiography of rodent eyes is hampered by a poor view of the peripheral retina and difficulty in performing fundus photography. Methods of staining or filling retinal vessels are unr...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1006/mvre.1993.1042
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abstract::Overexpression of EGFR plays a key-role in head and neck squamous cell carcinoma (HNSCC) and justifies the extensive use of cetuximab, a monoclonal anti-EGFR antibody, as well as EGFR-tyrosine kinase inhibitors (EGFR-TKI), which have been reported to inhibit tumor cell growth and the secretion of pro-angiogenic factor...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/j.mvr.2011.07.008
更新日期:2012-03-01 00:00:00
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journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/s0026-2862(03)00021-9
更新日期:2003-07-01 00:00:00
abstract::Estrogen induces endothelial progenitor cells (EPCs) migration and proliferation, which may serve as a potential target for coronary artery disease, but the mechanisms are unclear. We hypothesized that estrogen receptors (ERs) and phosphatidylinositol 3-kinase (PI3K) signaling pathway, which represent particularly imp...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/j.mvr.2007.02.009
更新日期:2008-01-01 00:00:00
abstract::Laser Doppler flowmetry (LDF) of forearm skin blood flow, combined with iontophoretically-administered acetylcholine and sodium nitroprusside and wavelet spectral analysis, was used for noninvasive evaluation of endothelial function in 17 patients newly diagnosed with New York Heart Association class II-III congestive...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/j.mvr.2008.07.006
更新日期:2008-11-01 00:00:00
abstract::This study determined the contribution of cytochrome P450 (CP450) 4A enzyme metabolites of arachidonic acid in mediating the constriction of isolated rat skeletal muscle resistance arteries in response to elevated PO2. Gracilis arteries (GA) were viewed via television microscopy and constrictor responses to elevated P...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1006/mvre.2001.2341
更新日期:2001-11-01 00:00:00
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journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/j.mvr.2014.12.002
更新日期:2015-03-01 00:00:00
abstract::Diabetic retinopathy (DR) is a disease that causes blindness due to vascular leakage or abnormal angiogenesis. Hepatocyte growth factor (HGF) is increased in the serum or vitreous fluid in proliferative diabetic retinopathy (PDR) patients, although the effect of HGF on the blood vessels remains unclear. This study foc...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/j.mvr.2020.104103
更新日期:2021-01-01 00:00:00
abstract::Techniques of intravital microscopy were used to assess the effect of the nonsteroidal anti-inflammatory drugs (NSAIDs), indomethacin and ibuprofen, on the microcirculation. Hemodynamics in venules of the rat mesentery were studied in terms of vessel diameter, red blood cell velocity, and leukocyte-endothelium interac...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1006/mvre.1993.1016
更新日期:1993-03-01 00:00:00
abstract::Nonspecific vasodilatation during iontophoresis is an important confounding factor in experimental pharmacology. In this investigation, we studied the involvement of sensory nerves and histamine-related reactions in causing nonspecific vasodilatation in a model of anodal and cathodal iontophoresis of sodium chloride. ...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/j.mvr.2003.12.002
更新日期:2004-03-01 00:00:00
abstract::Endothelial cells represent one of the critical cellular elements in tumor microenvironment playing a crucial role in the growth and progression of cancer through controlling angiogenesis. Vascular endothelial growth factor (VEGF) produced from tumor cells is essential for the expansion of breast cancer and may functi...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/j.mvr.2013.02.008
更新日期:2013-05-01 00:00:00
abstract::Strychnine is known to possess anti-inflammatory and antitumour activity, but its roles in tumour angiogenesis, the key step involved in tumour growth and metastasis, and the involved molecular mechanism are still unknown. We aimed to investigate the effects of strychnine on key components of inflammatory angiogenesis...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/j.mvr.2013.01.003
更新日期:2013-05-01 00:00:00
abstract::This paper presents the results of a circulation analysis using an image based network model of a murine retinal vasculature, which closely represents the 3D vascular distribution of the retina. The uneven distribution of the red blood cells at vascular network bifurcations (i.e., plasma skimming effect), the microvas...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/j.mvr.2010.02.005
更新日期:2010-07-01 00:00:00
abstract::Ischemia/Reperfusion injury and hemolysis are characterized by erythrocyte lysis and release of free heme into the microcirculation. Following substantial erythrocyte lysis, heme overwhelms circulatory heme-binding protein networks rapidly forming hemin, the oxidized form of iron protoporphyrin IX. Hemin's role in mod...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/j.mvr.2007.01.002
更新日期:2007-05-01 00:00:00
abstract::This study aims to assess the relationship between spontaneous oscillations in changes in cerebral tissue oxyhemoglobin concentrations (Delta [HbO2]) and arterial blood pressure (ABP) signals in healthy elderly subjects during the resting state using wavelet coherence analysis. Continuous recordings of near-infrared s...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/j.mvr.2014.02.008
更新日期:2014-05-01 00:00:00
abstract::Studies of microvascular geometry made from microscope observations of tissues in vivo or after perfusion with a silastic elastomer or india ink are restricted to a two-dimensional field of view. Microvascular corrosion casts, however, if of sufficient rigidity and structural integrity, can yield three-dimensional inf...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/0026-2862(83)90044-4
更新日期:1983-01-01 00:00:00
abstract::Homeostasis around vascular endothelium is a function of the equilibrium between the bioavailability of nitric oxide (NO) and oxidizing reactive oxygen species (ROS). Within the vascular endothelium, NO enhances vasodilatation, reduces platelet aggression and adhesion (anti-thrombotic), prevents smooth muscle prolifer...
journal_title:Microvascular research
pub_type: 杂志文章,评审
doi:10.1016/j.mvr.2018.03.012
更新日期:2018-09-01 00:00:00
abstract::The relative magnitude of vascular reactivity to inhaled gas stimuli in the major retinal arterioles has not been systematically investigated. The purpose of this study was to compare the magnitude of retinal vascular reactivity in response to inhaled gas provocation at equivalent measurement sites in the superior-, a...
journal_title:Microvascular research
pub_type: 杂志文章,随机对照试验
doi:10.1016/j.mvr.2011.11.002
更新日期:2012-03-01 00:00:00
abstract:AIMS:The purpose of the present study was to investigate the possible role of TIPE2 on acute lung injury (ALI) induced by myocardial ischemia/reperfusion (MIR) in diabetic rats. METHODS:Sprague-Dawley (SD) rats were randomly separated into four groups: control+sham (C + sham); control+MIR (C + MIR); diabetes+sham (D +...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/j.mvr.2020.104009
更新日期:2020-07-01 00:00:00
abstract:OBJECTIVES:Calcium channel inhibitors have beneficial impact on microcirculation, but beta-blocker effect is controversial. Clinicians still do not agree on beta-blocker combination with other treatments in the management of impaired microcirculation. The aim of the present study was to describe the effects of beta-blo...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/j.mvr.2011.04.004
更新日期:2011-07-01 00:00:00
abstract::The effect of hemodilution on oxygen delivery to the tissue was investigated analytically by taking into consideration the oxygen loss that occurs along the arterial microvasculature due to diffusion into the tissue and shunting to parallel running venules. The theoretical findings were related to experimental data on...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/0026-2862(87)90062-8
更新日期:1987-11-01 00:00:00
abstract::Blood flow studies in the brain, heart, and other organs suggest that there could be interaction between nitric oxide (NO) and adenosine. This possibility was investigated in the optic nerve head (ONH) during photic stimulation of the dark-adapted cat eye. Functional activation of ONH blood flow was measured by laser ...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1006/mvre.2002.2432
更新日期:2002-09-01 00:00:00
abstract::In this paper we quantitatively investigate the hypothesis proposed by Michel (Exp. Physiol. 82, 1-30, 1997) and Weinbaum (Ann. Biomed. Eng. 26, 1-17, 1998) that the Starling forces are determined by the local difference in the hydrostatic and colloid osmotic pressure across the endothelial surface glycocalyx, which w...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1006/mvre.1999.2177
更新日期:1999-11-01 00:00:00
abstract::Angiogenesis, or the growth of new blood vessels, is critical to both health and disease. Several genes are implicated in the regulation of angiogenesis, such as genes encoding growth factors, cytokines, and the extracellular matrix, as well as transcription factors. Among them, Hox genes exert master regulatory effec...
journal_title:Microvascular research
pub_type: 杂志文章,评审
doi:10.1016/j.mvr.2013.02.009
更新日期:2013-05-01 00:00:00
abstract:BACKGROUND:Sepsis is a fatal systemic inflammatory response syndrome caused by severe infection. The aim of this study was to measure hepatic microcirculation during the sepsis with laser speckle contrast imaging (LSCI), as well as investigating the underlying mechanisms. METHODS:Sepsis was induced by cecal ligation a...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/j.mvr.2014.10.006
更新日期:2015-01-01 00:00:00
abstract::Endoneurial capillaries in nerve biopsies from 12 adult diabetic cats with varying degrees of neurological dysfunction were examined for evidence of microvascular pathology and compared to nerves obtained at necropsy from 7 adult non-diabetic cats without clinical evidence of neurological dysfunction. As reported prev...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/j.mvr.2007.12.002
更新日期:2008-04-01 00:00:00
abstract::We examined the impact of lymph flow obstruction in large post-nodal lymphatic vessels in sheep. A silk ligature was placed 2 cm downstream from the prescapular or popliteal lymph node and tightened to interrupt flow. At 6, 12 and 16 weeks after lymph flow blockage, a network of small interconnecting lymphatics (appro...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/j.mvr.2006.11.003
更新日期:2007-05-01 00:00:00
abstract::The contribution of the pleural mesothelium to pleural liquid and protein transport is still vigorously debated. Recent in vitro studies of stripped pleural membrane and free-standing pericardium have demonstrated active ion solute coupled transport of liquid and transcytosis of protein. However, the relative contribu...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/j.mvr.2005.10.003
更新日期:2005-11-01 00:00:00
abstract:PURPOSE:To investigate conjunctival microvascular responses in patients with mild diabetic retinopathy (MDR) and methylenetetrahydrofolate reductase (MTHFR) polymorphisms (D + PM) after administration of Ocufolin™, a medical food containing 900 μg l-methylfolate (levomefolate calcium or [6S]-5-methyltetrahydrofolic aci...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/j.mvr.2020.104066
更新日期:2020-11-01 00:00:00