Plasma levels of potassium and magnessium after modified ultrafiltration in pediatric cardiac surgery with cardiopulmonary bypass.

OBJECTIVE: Modified ultrafiltration (MUF) reduces some of the complications associated with cardiopulmonary bypass (CPB) in pediatric cardiac surgery. However, we have observed hypokalemia and hypomagnesemia in children when MUF is used. Such alterations may elicit severe arrhythmias in the postoperative period. To date, no studies have focused on the effects MUF may have in plasma levels of potassium (K) and magnesium (Mg). The objective of our study was to determine if there is any variation in plasma levels of K (plK) and Mg (plMg) after MUF in children undergoing cardiac surgery with CPB. PATIENTS: Sixteen children scheduled for cardiac surgery with CBP and MUF were prospectively studied. Anesthetic, CPB and MUF management were standardized for all patients, the latter lasting for 10 minutes. RESULTS: Plasma K average levels before and after MUF were 4.16 mmol/L and 3.58 mmol/L, respectively. The average plasma Mg levels before and after MUF were 4.82 mmol/L and 4.81 mmol/L, respectively. CONCLUSIONS: The plasma level of K is reduced by 13.7% after MUF (p<0.0001). The reduction in Mg at the same period of time was not statistically significant (p<0.970).

[Morphologic changes in lens cells of the rabbit eye after irradiation with neodymium-YAG laser with wavelength 1.32 micrometers]. / Morfologicheskie izmeneniia v kletakh khrustalika glaza krolika posle oblucheniia neodimovym AIG-lazerom s dlino i volny 1,32 mkm.

The exposure of the rabbit's lens to laser radiation (1.32 microns) induced complex damage probably due to heat-related changes in the lens fibers at the site of the beam action. Heating and coagulation of the tissues changed the position or led to the rupture of some lens fibers. Swelling of the fibers on the lens equator may result from damage to the cell membranes in the anterior part of the lens.

[The choice of the radiation parameters in the laser reconstruction of the pupil]. / K vyboru parametrov izlucheniia pri lazernoi rekonstruktsii zrachkovogo otverstiia.

The phenomenon of a "local punch" of tissues in the zone of nano- or picosecond impulses of neodymium: YAG-laser radiation focusing allows to increase energy in the pulse by one order as compared with traditionally used energy. At this, in order to achieve the initial effect it becomes possible to reduce the number of shots by two orders and thus to increase the spot of radiation. The summary energy of action absorbed in the eye remains the same and that's why the number of complications doesn't increase. The widening of possibilities to choose a laser source for micro- and macroperforations allows, when prescribing the treatment, to more reliably consider clinical peculiarities in each concrete case.

[Effect of pulsed laser radiation on the lysosomes of Ehrlich ascitic tumor cells]. / Vliianie impul'snogo lazzernogo izlucheniia na lizosomy kletok astsitnoi opukholi Erlikha.

The results of a study on the effect of neodymium pulsed laser radiation on Ehrlich ascites tumor lysosomes are discussed. Tumor cell suspension was exposed in vitro to 10 pulses of laser irradiation with fluences of 10, 25 and 100 J/cm2, at a wavelength of 1.06 microns and a pulse duration of 1 microsecond. A rise in the free and total activities of acid phosphatase in the fraction of isolated lysosomes was registered one or four hours after exposure, particularly, at fluences of 10 and 25 J/cm2. However, laser radiation did not affect acid phosphatase activity in preparations of solubilized enzyme. Special experiments involving the use of detergents showed the increased activity of acid phosphatase in isolated lysosome fraction to be due to labilization of cytoplasmic membranes of tumor cells.

[Reflection coefficients in tumor exposure to high-energy laser radiation]. / O koéffitsientakh otrazheniia pri vozdeistvii moshchnogo lazernogo izlucheniia na opukholi.

It was shown that a considerable portion of neodymium laser radiation is reflected by human skin neoplasms and transplantable tumors in mice. Melanomas were found to have lower coefficients of reflection compared with nonpigmented tumors. A reflection capacity of all tumors is increased as the energy per impulse increases.

[Radioautographic study of a culture of fibroblasts after irradiation by a neodymium laser]. / Radioavtograficheskoe issledovanie kul'tury fibroblastov posle oblucheniia neodinovym lazerom.

By means of radioautographic method, with 3H-thymidin application there were studied: mitotic activity, the number of DNA-synthesizing cells, growth fraction and population number of fibroblast culture irradiated with a single impulse of neodymium laser at energy density within 1 Dg/cm2--100 Dg/cm2. Under the influence of small doses of laser radiation (1--10 Dg/cm2) the number of dividing DNA-synthesizing cells increased, together with proliferative pool and the number of cells in the field of vision. At energy density of laser radiation equal to 50 Dg/cm2, and especially to 100 Dg/cm2 despite increased mitotic index and labelled cells index, registered during first hours of the effect, proliferative pool decreased and population growth rate lowered. These doses of laser radiation produced destruction of a rather large part of the cells in a monolayer.

[Effect of high-power pulse laser radiation on experimental tumor metastasis]. / Vliianie moshchnogo impul'snogo lazernogo izlucheniia na metastazirovanie éksperimental'nykh opukholei.

Under study was the effect of the energy density and pulse duration of laser radiation on metastasization of Lewis carcinoma and melanoma B16. It was shown that laser irradiation of blastomas, the energy density of the former not exceeding 400 joule/cm2 and the pulse duration being 1 msec, not only fails to contribute to tumor proliferation but, on the contrary, somewhat reduces the number of pulmonary metastases. The phenomenon of such kind is observed in simultaneous rise of the energy density up to 800 joule/cm2 and lengthening of the pulse up to 6 msec.

[Immunologic reactivity of the body after laser irradiation of experimental neoplasms]. / Immunologicheskaia reaktivnost' organizma pri obluchenii lazernym izlucheniem eksperimental'nykh opukholei.

The irradiation of Garding-Passey and B16 melanomas results in an increased number of antibody-forming cells (AFC) in the spleen and an increased level in blood serum of autoantibodies against antigens of the irradiated tumor and of the liver and kidneys of the same animals, as well. Some increase of these indices was noted also in the irradiation of normal tissues.