• Journal of Chest Surgery
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• v.38 no.5 s.250
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• pp.323-334
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• 2005

Background: Gene therapy is a new and promising option for the treatment of severe myocardial ischemia by therapeutic angiogenesis. The goal of this study was to elucidate the efficacy of therapeutic angiogenesis by using VEGF165 in large animals. Material and Method: Twenty-one pigs that underwent ligation of the distal left anterior descending coronary artery were randomly allocated to one of two treatments: intramyocardial injection of pCK-VEGF (VEGF) or intramyocardial injection of pCK-Null (Control). Injections were administered 30 days after ligation. Seven pigs died during the trial, but eight pigs from VEGF and six from Control survived. Echo-cardiography was performed on day 0 (preoperative) and on days 30 and 60 following coronary ligation. Gated myocardial single photon emission computed tomography imaging (SPECT) with $^{99m}Tc-labeled$ sestamibi was performed on days 30 and 60. Myocardial perfusion was assessed from the uptake of $^{99m}Tc-labeled$ sestamibi at rest. Global and regional myocardial function as well as post-infarction left ventricular remodeling were assessed from segmental wall thickening; left ventricular ejection fraction (EF); end systolic volume (ESV); and end diastolic volume (EDV) using gated SPECT and echocardiography. Myocardium of the ischemic border zone into which pCK plasmid vector had been injected was also sampled to assess micro-capillary density. Result: Micro-capillary density was significantly higher in the VEGF than in Control ($386\pm110/mm^{2}\;vs.\;291\pm127/mm^{2};\;p<0.001$). Segmental perfusion increased significantly from day 30 to day 60 after intramyocardial injection of plasmid vector in VEGF ($48.4\pm15.2\%\;vs.\;53.8\pm19.6\%;\;p<0.001$), while no significant change was observed in the Control ($45.1\pm17.0\%\;vs.\;43.4\pm17.7\%;\;p=0.186$). This resulted in a significant difference in the percentage changes between the two groups ($11.4\pm27.0\%\;increase\;vs.\;2.7\pm19.0\%\;decrease;\;p=0.003$). Segmental wall thickening increased significantly from day 30 to day 60 in both groups; the increments did not differ between groups. ESV measured using echocardiography increased significantly from day 0 to day 30 in VEGF ($22.9\pm9.9\;mL\;vs.\;32.3\pm9.1\;mL;\; p=0.006$) and in Control ($26.3\pm12.0\;mL\;vs.\;36.8\pm9.7\;mL;\;p=0.046$). EF decreased significantly in VEGF ($52.0\pm7.7\%\;vs.\;46.5\pm7.4\%;\;p=0.004$) and in Control ($48.2\pm9.2\%\;vs.\;41.6\pm10.0\%;\;p=0.028$). There was no significant change in EDV. The interval changes (days $30\~60$) of EF, ESV, and EDV did not differ significantly between groups both by gated SPECT and by echocardiography. Conclusion: Intramyocardial injection of pCK-VEGF165 induced therapeutic angiogenesis and improved myocardial perfusion. However, post-infarction remodeling and global myocardial function were not improved.

• Applied Microscopy
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• v.21 no.1
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• pp.1-20
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• 1991

The effects of exogenous $Ca^{2+}$ stimulation on the post-ischemic myocardial cells were studied using isolated Langendorff-perfused guinea pig hearts. At the starting point of reperfusion, Tyrode solutions, each containing 2.0mM, 4.0mM and 8.0mM $CaCl_2$ respectively, were administered for 2 minutes apart by descending, ascending, or by combined sequences followed by standard Tyrode solution containing 1.0mM $CaCl_2$. The minutes of global ischemia produced reversible but moderate to severe degree of myocardial ultrastructrual changes including focal destruction of sarcolemma, loss of nuclear matrix, clumping and margination of chromatins, mitochondrial swelling, destruction of mitochondrial cristae, shortening of sarcomeres, focal loss of myofibrils, and separation of cell junctions. In spite of reperfusion, the ultrastructure was more severely damaged and irreversible changes such as intracellular fluid accumulation, contracted sarcomeres, mitochondrial destruction, disruption of sarcolemma, loss of nuclear matrix, and separation of cell junction were observed in a large number of cells. In contrast, Tyrode-perfused $Ca^{2+}$-stimulated myocardial cells showed relatively well preserved ultrastucture, except slight changes including focal mitochondrial swelling, widening of T-tubule, and widening of cell junctions, especially at fasciae adherentes. The post-ischemic $Ca^{2+}$-stimulated reperfused myocardial cells produced focal changes such as mitochondrial destruction, disintegration of sarcolemma, widening of T-tubule, and intracellular fluid accumulation with slight variation in degree of changes by the method of $Ca^{2+}$ administration sequence. However, in a large number of the myocardial cells, chromatins were redistributed relatively evenly in the nuclear matrix, mitochondrial cristae were tightly packed, and a considerable number of intramitochondrial granules and glycogen granules reap-pealed. These results indicate that exogenous $Ca^{2+}$ stimulation in the initial period of reperfusion may be beneficial to salvage or to reduce the post-ischemic myocardium from further deleterious changes, and that the beneficial effects may be derived from the reserves of the function of the intracellular $Ca^{2+}$ regulating organelles and/or from the responsiveness of contractile apparatus to $Ca^{2+}$ stimulation.

• Applied Microscopy
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• v.30 no.4
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• pp.347-355
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• 2000

Zinc is one of the most abundant oligoelements in the living cell. It appears tightly bound to some metalloproteins and nucleic acids, loosely bound to some metallothioneins or even as free ion. Small amounts of zinc ions (in the nanomolar range) regulate a plentitude of enzymatic proteins, receptors and transcription factors, thus rolls need accurate homeostasis of zinc ions. Zinc is an essential catalytic or structural element of many proteins, and a signaling messenger that is released by neural activity at many central excitatory synapses. Growing evidences suggest that zinc may also be a key mediator and modulator of the neuronal death associated with transient global ischemia and sustained seizures, as well as perhaps other neurological disease stoles. Some neurons have developed mechanisms to accumulate zinc in specific membrane compartment ('vesicular zinc') which can be evidenced using histochemical techniques. Substances giving a bright colour or emitting fluorescence when in contact with divalent metal ions are currently used to detect them inside cells; their use leads to the so called 'direct' methods. The fixation and precipitation of metal ions as insoluble salt precipitates, their maintenance along the histological process and, finally, their demonstration after autometallographic development are essential steps for other methods, the so called 'indirect methods'. This study is a short report on the autometallograhical approaches for zinc detection in the central nervous system (CNS) by means of a modified selenium method.