Impedance Measurements in Cardiac Tissue

2002 ◽  
pp. 302-339 ◽  
Keyword(s):  
Cardiac Tissue ◽  
Impedance Measurements

scholarly journals Dihydrotestosterone induces pro-angiogenic factors and assists homing of MSC into the cardiac tissue

2018 ◽  
Vol 60 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Mirel-Adrian Popa ◽  
Maria-Cristina Mihai ◽  
Alina Constantin ◽  
Viorel Şuică ◽  
Cătălin Ţucureanu ◽  
...  
Keyword(s):  
Cardiac Tissue ◽  
Immunohistochemical Analysis ◽  
Therapeutic Tool ◽  
Tissue Slices ◽  
Impedance Measurements ◽  
Qrt Pcr ◽  
Gene And Protein Expression ◽  
Underlying Mechanisms

The use of mesenchymal stem cells (MSC) as a therapeutic tool in cardiovascular diseases is promising. Since androgens exert some beneficial actions on the cardiovascular system, we tested our hypothesis that this hormone could promote MSC-mediated repair processes, also. Cultured MSCs isolated from Wharton’s jelly were exposed to 30 nM dihydrotestosterone (DHT) for 1 or 4 days and the effects of the hormone on their growth/migration/adhesion and the underlying mechanisms were assessed. Results were obtained by real-time cell impedance measurements, and DNA quantification showed that DHT increased MSC proliferation by ~30%. As determined by xCELLigence system, DHT augmented (~2 folds) the migration of MSC toward cardiac tissue slices (at 12 h), and this effect was blocked by flutamide, an androgen receptor (AR) antagonist. Exposure of cells to DHT, upregulated the gene and protein expression of AR, EMMPRIN and MMP-9 and downregulated the expression of MMP-2. DHT significantly induced the release of nitric oxide by MSC (≥2-fold) and flutamide blocked this effect. When MSCs were co-cultured with cardiac slices, immunohistochemical analysis and qRT-PCR showed that the integration of DHT-stimulated MSC was significantly higher than that of in controls. In conclusion, our findings provide the first evidence that DHT promotes MSC growth, migration and integration into the cardiac slices. The modulating effects of DHT were associated with upregulation of ARs and of key molecules known to promote tissue remodeling and angiogenesis. Our findings suggest that priming of MSC with DHT may potentially increase their capability to regenerate cardiac tissue; in vivo studies are needed to confirm our in vitro findings.

A critique of impedance measurements in cardiac tissue

1986 ◽  
Vol 14 (4) ◽  
pp. 307-322 ◽  
Author(s):  
Robert Plonsey ◽  
Roger C. Barr
Keyword(s):  
Cardiac Tissue ◽  
Impedance Measurements

Cytopathology of Cardiac Tissue from Daunomycin-Treated Mice

1971 ◽  
Vol 29 ◽  
pp. 550-551
Author(s):  
Robert H. Liss ◽  
Frances A. Cotton
Keyword(s):  
Cardiac Tissue ◽  
Cardiac Toxicity ◽  
Drug Distribution ◽  
Personal Communication ◽  
Intravenous Dose ◽  
Single Intravenous Dose ◽  
Physiologic Saline ◽  
Histopathologic Changes ◽  
Distribution Studies ◽  
Lung And Kidney

Daunomycin, an antibiotic used in the clinical management of acute leukemia, produces a delayed, lethal cardiac toxicity. The lethality is dose and schedule dependent; histopathologic changes induced by the drug have been described in heart, lung, and kidney from hamsters in both single and multiple dose studies. Mice given a single intravenous dose of daunomycin (10 mg/kg) die 6-7 days later. Drug distribution studies indicate that the rodents excrete most of a single dose of the drug as daunomycin and metabolite within 48 hours after dosage (M. A. Asbell, personal communication).Myocardium from the ventricles of 6 moribund BDF1 mice which had received a single intravenous dose of daunomycin (10 mg/kg), and from controls dosed with physiologic saline, was fixed in glutaraldehyde and prepared for electron microscopy.

Iron storage sites in the myocardium as revealed by cytohistochemistry

1988 ◽  
Vol 46 ◽  
pp. 394-395
Author(s):  
M. Ashraf ◽  
F. Thompson ◽  
S. Miki ◽  
P. Srivastava
Keyword(s):  
Cardiac Tissue ◽  
Coronary Perfusion ◽  
Intracellular Iron ◽  
Ether Anesthesia ◽  
Intense Staining ◽  
Iron Storage ◽  
Thin Sections ◽  
Rat Hearts ◽  
Cacodylate Buffer ◽  
Made In

Iron is believed to play an important role in the pathogenesis of ischemic injury. However, the sources of intracellular iron in myocytes are not yet defined. In this study we have attempted to localize iron at various cellular sites of the cardiac tissue with the ferrocyanide technique.Rat hearts were excised under ether anesthesia. They were fixed with coronary perfusion with 3% buffered glutaraldehyde made in 0.1 M cacodylate buffer pH 7.3. Sections, 60 μm in thickness, were cut on a vibratome and were incubated in the medium containing 500 mg of potassium ferrocyanide in 49.5 ml H2O and 0.5 ml concentrated HC1 for 30 minutes at room temperature. Following rinses in the buffer, tissues were dehydrated in ethanol and embedded in Spurr medium.The examination of thin sections revealed intense staining or reaction product in peroxisomes (Fig. 1).

Immunoelectron microscope detection of C-type natriuretic peptide in normal human atrial tissue

1993 ◽  
Vol 51 ◽  
pp. 388-389
Author(s):  
Chi-Ming Wei ◽  
Margaret Hukee ◽  
Christopher G.A. McGregor ◽  
John C. Burnett
Keyword(s):  
Amino Acid ◽  
Natriuretic Peptide ◽  
Vascular Tone ◽  
Cardiac Tissue ◽  
Ring Structure ◽  
Terminal Amino Acid ◽  
Amino Acid Peptide ◽  
Normal Human ◽  
Terminal Amino ◽  
The Brain

C-type natriuretic peptide (CNP) is a newly identified peptide that is structurally related to atrial (ANP) and brain natriuretic peptide (BNP). CNP exists as a 22-amino acid peptide and like ANP and BNP has a 17-amino acid ring formed by a disulfide bond. Unlike these two previously identified cardiac peptides, CNP lacks the COOH-terminal amino acid extension from the ring structure. ANP, BNP and CNP decrease cardiac preload, but unlike ANP and BNP, CNP is not natriuretic. While ANP and BNP have been localized to the heart, recent investigations have failed to detect CNP mRNA in the myocardium although small concentrations of CNP are detectable in the porcine myocardium. While originally localized to the brain, recent investigations have localized CNP to endothelial cells consistent with a paracrine role for CNP in the control of vascular tone. While CNP has been detected in cardiac tissue by radioimmunoassay, no studies have demonstrated CNP localization in normal human heart by immunoelectron microscopy.

Confocal imaging of calcium in intact ventricular muscle provides a new view of excitation-contraction coupling

1996 ◽  
Vol 54 ◽  
pp. 738-739
Author(s):  
W.G. Wier
Keyword(s):  
Local Control ◽  
Cardiac Tissue ◽  
Cell Function ◽  
Isolated Heart ◽  
Cardiac Cells ◽  
Confocal Imaging ◽  
Ion Concentration ◽  
Heart Cell ◽  
Free Calcium ◽  
Heart Cells

A fundamentally new understanding of cardiac excitation-contraction (E-C) coupling is being developed from recent experimental work using confocal microscopy of single isolated heart cells. In particular, the transient change in intracellular free calcium ion concentration ([Ca2+]i transient) that activates muscle contraction is now viewed as resulting from the spatial and temporal summation of small (∼ 8 μm3), subcellular, stereotyped ‘local [Ca2+]i-transients' or, as they have been called, ‘calcium sparks'. This new understanding may be called ‘local control of E-C coupling'. The relevance to normal heart cell function of ‘local control, theory and the recent confocal data on spontaneous Ca2+ ‘sparks', and on electrically evoked local [Ca2+]i-transients has been unknown however, because the previous studies were all conducted on slack, internally perfused, single, enzymatically dissociated cardiac cells, at room temperature, usually with Cs+ replacing K+, and often in the presence of Ca2-channel blockers. The present work was undertaken to establish whether or not the concepts derived from these studies are in fact relevant to normal cardiac tissue under physiological conditions, by attempting to record local [Ca2+]i-transients, sparks (and Ca2+ waves) in intact, multi-cellular cardiac tissue.

Targeted gene delivery to the cardiac tissue by adenovirus conjugated magnetic nanobeads

2011 ◽  
Vol 59 (S 01) ◽  
Author(s):  
Y Zhang ◽  
W Li ◽  
W Wang ◽  
L Ou ◽  
A Liebold ◽  
...  
Keyword(s):  
Gene Delivery ◽  
Cardiac Tissue ◽  
Targeted Gene Delivery ◽  
Magnetic Nanobeads
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