Success of transmyocardial laser revascularization is determined by the amount and organization of scar tissue produced in response to initial injury: results of ultraviolet laser treatment.

BACKGROUND AND OBJECTIVE: Previous studies of transmyocardial laser revascularization have reported open channels after ultraviolet laser treatment and closed channels with infrared lasers. We speculated that differences in long-term channel patency were determined by the healing response to injury. METHODS: Channels were made in rat hearts with a frequency-tripled neodymium:YAG laser, at 5 and 10 mJ per pulse, by advancing an optic fiber through the myocardium, from the epicardium to the ventricular cavity. Several months later, we challenged the ability of the channel to supply blood by arterial occlusion and examined the channel structure with polarized light microscopy. RESULTS: Low-pulse energy was associated with lower patency, more fibrosis, and larger infarcts than was the higher energy. Open channels were surrounded by collagen fibers aligned parallel to the channel; in closed channels, fibers were aligned perpendicular to the original channel direction. CONCLUSION: The amount of initial injury and its repair determine channel patency and function.

[The electrical impedance indicator dilution method in studying the basic hemodynamic parameters during dialysis]. / Metod razvedeniia élektroimpedansnykh indikatorov v issledovanii osnovnykh parametrov gemodinamiki vo vremia dializa.

The procedure for measuring cardiac output and circulating blood volume is based on blood ability to modify its electrical conductance due to the amount of introduced ions (0.9% sodium chloride solution) or undissociated molecules (5% glucose solution). The cardiac output and circulating blood volume were calculated after measuring an area under the electrical impedance indicator dilution curve using the given formulas. With the described and thermodilution methods, the cardiac output was compared (r = 0.95). The correlation factor with the radioisotopic method in measuring the circulating blood volume was 0.88. Clinical investigations carried out in 47 patients on a programmed hemodialysis showed a significant decrease in cardiac output approximately by 700 ml/mi (7.9%) and circulating blood volume by an average of 900 ml (15.2%) by the end of a hemodialysis session, the rate of the circulating blood volume to body weight being also decreased. There was a predominant fluid "release" from the vascular bed.

Mechanisms of triboluminescence.

The purpose of this paper has been to develop the theoretical treatment of the triboexcitation mechanisms due to the electric field effect and the pressure effect and to show how to analyze the triboluminescent spectra to determine the external factors that affect or induce the triboluminescence.