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T A Popov

Publications and source records attributed to T A Popov.

27 records · Page 2Linked to original sources
PubMedDate not supplied

Monitoring of fluctuating airway obstruction and episodes of coughing by thoracic electrical impedance.

The most prominent feature of bronchial asthma is the fluctuating airway obstruction of the affected subjects. Cough is also one of the major symptoms of asthma, but of other conditions as well. The continuous registration of airway obstruction and coughing in the working or open-air environment or at the homes of the potential sufferers may help establish a sometimes elusive diagnosis. To this purpose we developed a method using a measurement of the changes in the chest basal electrical impedance (Z0). A portable device for long-term recording of the Z0 signal was built using a microprocessor system. In order to assess both gradual Z0 changes, suggestive of altering airway patency and coughing episodes (characterized by abrupt changes), a continuous analogue-to-digital conversion (ADC) loop with a sampling frequency of 16 Hz was programmed. After completion of the recording, the memory of the portable instrument can be downloaded to a PC system for assessment and analysis. Appropriate averaging and filtering procedures have been worked out. This device may be further upgraded to give out a signal when Z0 starts to increase, so as to prevent a full-blown asthmatic crisis.

Asthma↗
PubMedDate not supplied

[Effect of mixed function oxidases on phthalophos transformation in rat liver].

Phthalophos, organophosphoric pesticide, in the perfused isolated liver of rats transforms to water-soluble oxymethyl phthalimide and phthalimide. The induction of the liver hydroxylating enzymic system with milbex accelerates transformation of phthalophos: in 5 min only 14% of its initial amount is found in perfusate, while in the control--52%. The inhibition of the hydroxylating enzymic system with tetramethylthiuramdisulphide (dithiocarbamate pesticide) inhibits transformation of phthalophos: in 15 min perfusate contains 33% of its initial amount and the control--16%. Induction and inhibition of the hydroxylating enzymic system of the liver affect essentially the phthalophos toxicodynamics, decreasing the degree of the cholinesterase activity.

Animals↗
PubMedDate not supplied

[Dinitroorthocresol dissociation of oxidative phosphorylation in the rat liver perfused in situ].

Perfusion of the rat liver in situ for 150 min provides for maintaining optimal values of acid-base balance for the following indexes: surplus of bases, content of standard bicarbonate, buffer bases pH, pO2, pCO2, HbO2, the level of bile secretion, content of lactate, pyruvate, ATP, ADP, that evidences for a high functional activity in the tissue. Introduction of dinitro-ortho-cresol (DNC) into the perfusion liquid causes development of acidosis. DNC results in dissociation of oxidative phosphorylation: the content of ATP and intensity of inorganic phosphorus utilization decrease, oxygen uptake intensifies. A compensatory increase in the glycolysis intensity directed to maintaining the level of macroergs under these conditions is is pronounced in the intensified uptake of glucose, in a rise in the content of lactate in perfusate and an increase in the pyruvate kinase activity in the liver. The redox state of NAD-pairs (ratio of [NAD+] : [NADN] calculated from the content of redox metabolites and the equilibrium constant for the lactate dehydrogenase system shifts toward an increase in the reducing properties of hepatocytes cytoplasm. The phosphate potential value calculated from the ratio [ATP] : [ADP] - [Pinor] lowers under conditions of the experiment.

Acid-Base Equilibrium↗