PubMed Health⌕ Search

Biomedical subjects

V Hrachovina

Publications and source records attributed to V Hrachovina.

At least 19 recordsLinked to original sources
PubMed1995

Alternating versus synchronous ventilation of left and right lungs in piglets.

OBJECTIVE: We tested whether alternating ventilation (AV) of each lung (i.e. with a phase difference of half a ventilatory cycle) would decrease central venous pressure and so increase cardiac output when compared with simultaneous ventilation (SV) of both lungs. THEORY: If, during AV, the inflated lung expands partly via compression of the opposite lung, mean lung volume will be smaller during AV than SV. As a consequence, mean intrathoracic pressure (as cited in the literature), and therefore, central venous pressure will be smaller. DESIGN: The experiments were performed in seven anaesthetized and paralyzed piglets using a double-piston ventilator. Minute ventilation was the same during AV and SV. Starting at SV, we alternated three times between AV and SV for periods of 10 min. RESULTS: During AV, central venous pressure was decreased by 0.7 mmHg and cardiac output was increased by 10 +/- 4.4% (mean, +/-SD) compared with SV. AV also resulted in increased arterial pressure. During one-sided inflation with closed outlet of the opposite lung, a pressure rise occurred in the opposite lung, indicating compression. CONCLUSION: The higher cardiac output during AV than SV can be explained by the fact that central venous pressure is lower during AV. This lower central venous pressure is very probably due to the lower mean intrathoracic pressure caused by compression of the opposite lung during unilateral inflation.

Animals↗
PubMed1994

Diffusing capacity dependent on lung volume and age in normal subjects.

In this study we determined reference values of total diffusing capacity of carbon monoxide (DLCO) and DLCO per liter alveolar volume (DLCO/VA) at total lung capacity (TLC) and at lung volumes below TLC in sitting position. In 55 healthy nonsmoking volunteers (20-85 yr old), we determined reference values at TLC level in which age was the only parameter. In a subgroup (n = 16) these references did not change by correction for normal variability in hemoglobin concentration. In all volunteers DLCO decreased and DLCO/VA increased with decreasing VA. The increase in DLCO/VA was linear and less in older subjects. We derived equations to calculate reference values of DLCO/VA for lung volumes at and below TLC with two methods: 1) "random coefficients linear" model, which calculates the reference values directly, and 2) a conversion method, which calculates DLCO/VA for lower VA levels from reference values at TLC. An advantage of the conversion method is the suitability of DLCO/VA reference values at TLC of other populations. A disadvantage is the greater standard deviation of these reference values compared with those obtained by the random coefficients linear method. DLCO can be found by multiplying DLCO/VA with VA.

Adult↗
PubMed1991

[Metamorphosis of vitelliform macular degeneration].

The authors describe the case of vitelliform macular degeneration of a mother and daughter whom they followed up using different examination methods incl. electrophysiological ones and fluorescent angiography. During the observation subjective deterioration of vision occurred in the daughter which was due to transformation of the typical picture of egg yolk into a further stage of pathological changes.

Adult↗
PubMed1990

[Lactate dehydrogenase and malate dehydrogenase activity in the glial and neuronal fractions of the brain tissue in rats of various ages].

The authors investigated in Wistar strain rats of both sexes aged 10 days and in adult rats (aged 90 days) the activity of lactic dehydrogenase (E.C.1.1.1.27) and malic dehydrogenase (E.C.1.1.1.37) in the neuronal and glial fraction of the cerebral cortex. They found that during maturation the LDH activity declines in the neuronal fraction in a significant way (expressed per mg protein). The LDH activity in the neuronal fraction is always significantly higher than in the glial fraction. The G/N index declines slightly during development (from 0.30 to 0.23). In malic dehydrogenase the authors found also a decline of this activity in neuronal tissue during maturation, while in the glial fraction the activity of this enzyme does not change significantly. The G/N index increased as a result of the described developmental changes from 0.33 in 10-day-old rats to 0.55 in adult ones. The authors used for the isolation of the neuronal and glial fraction the method described by Lisý. LDH and MDH were estimated by previously described methods.

Aging↗