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S Soltysik

Publications and source records attributed to S Soltysik.

At least 19 recordsLinked to original sources
PubMed1996

Apparatus for studying behavior and learning in restrained rats.

A new treadmill/stand apparatus for a rat is described. It will be useful in behavioral experiments when control of the animal's position in the training chamber is required while considerable freedom of movement, including locomotion, is desired. The position and distance relative to sources of stimuli are thus kept constant. The speed and the distance of ambulation are easily monitored. The rats are sufficiently restrained to enable easy recording of various measures such as EKG, EMG or EEG, etc. Classical and instrumental conditioning procedures are easily implemented. An example of the data from acquisition training during Pavlovian conditioning is shown (diaphragm EMG, heart rate (HR), locomotion and vocalization).

Animals↗
PubMed1995

Structure/function studies of QS-21 adjuvant: assessment of triterpene aldehyde and glucuronic acid roles in adjuvant function.

QS-21, a purified Quillaja saponaria saponin immunologic adjuvant, contains two functional groups that we hypothesized to be involved in the adjuvant mechanism of action through charge or Schiff base interaction with a cellular target. Derivatives, prepared by modification of these sites, were prepared and tested for their ability to augment the immunogenicity of the antigen ovalbumin (OVA) in C57BL/6 mice. QS-21 derivatives that were modified at the carboxyl group on an anionic sugar, glucuronic acid, retained adjuvant activity for antibody stimulation, inducing relative increases in antibody titers similar to those induced by QS-21, although the minimum adjuvant dose required for this stimulation was increased several fold relative to the dose of unmodified QS-21. One of these derivatives also retained significant activity for induction of OVA-specific cytotoxic T-lymphocytes. In contrast, QS-21 derivatives modified at an aldehyde on the triterpene did not show adjuvant activity for antibody stimulation or for induction of cytotoxic T-lymphocytes, suggesting that this functional group may be involved in the adjuvant mechanism.

Adjuvants, Immunologic↗
PubMed1993

Adjuvant activity of QS-21 isomers.

QS-21, a reverse-phase purified triterpene glycoside from the South American tree Quillaja saponaria, can be further resolved into two peaks when chromatographed by high performance hydrophilic interaction chromatography. These two peaks demonstrated identical pseudomolecular ion weights and fragmentation patterns when analyzed by fast atom bombardment-mass spectroscopy. Carbohydrate analysis by monosaccharide composition and linkage analysis showed that a terminal apiose in the major peak was replaced by another pentose residue in the minor peak. Hence, the two peaks were structural isomers. Dose response curves for each isomer and reverse-phase purified QS-21 were similar, with a minimum effective dose of 5 micrograms in mice. This result indicates that the portion of QS-21 containing this variation is not critical for adjuvant activity.

Adjuvants, Immunologic↗
PubMed1987

Regulation of the butyryl-CoA dehydrogenase by substrate and product binding.

Until now, workers in the field of fatty acid metabolism have suggested that the substrates are isopotential with the enzymes and that the reactions are forced to completion by the formation of charge-transfer complexes [Gustafson, W. G., Feinberg, B. A., & McFarland, J. T. (1986) J. Biol. Chem. 261, 7733-7741]. To date, no experimental evidence for this hypothesis exists. The work presented here shows that the butyryl-CoA/crotonyl-CoA couple is not isopotential with the enzymes with which it interacts. The potential of the butyryl-CoA/crotonyl-CoA couple (E ' = -0.013 V) is significantly more positive than the potential of either of the enzymes with which it interacts, bacterial butyryl-CoA dehydrogenase (E ' = -0.079 V) and mammalian general acyl-CoA dehydrogenase (E ' = 0.133 V). These data imply that the regulation of enzyme potential is essential for any electron transfer from substrate to enzyme to occur in mammalian or bacterial systems. In support of this assertion, a significant shift in potential for bacterial butyryl-CoA dehydrogenase (an analogue of the mammalian enzyme) in the presence of butyryl-CoA and crotonyl-CoA is reported. The potential is shifted positive by 60 mV. Larger potential shifts will undoubtedly be observed with the mammalian enzyme, which would be consistent with the catalytic direction of electron transfer.

Acyl Coenzyme A↗
PubMed1987

The effects of reversible freezing inactivation and inhibitor binding on redox properties of L-amino-acid oxidase.

We measured the redox potentials of frozen inactivated L-amino-acid oxidase (L-amino-acid:oxygen oxidoreductase (deaminating), EC 1.4.3.2) and inhibitor-bound (anthranilic acid) enzyme, and compared these redox properties to those of active L-amino-acid oxidase and benzoate-bound D-amino-acid oxidase (EC 1.4.3.3), respectively. The redox properties of the inactive enzyme are similar to the properties of free flavin; the potential is within 0.015 V of free flavin and no radical stabilization is seen. This corresponds to the loss of most interactions between apoprotein and flavin. In contrast, the anthranilic acid lowers the amount of radical stabilized from 85% to 35%. The potentials are still 0.150 V positive of free flavin, indicating that in the presence of inhibitor, many flavin-protein interactions remain intact. The difference between this behavior and that of D-amino-acid oxidase bound to benzoate, where the amount of radical declined from 95% to 5%, is explained on the basis of the relative tightness of binding of apoprotein to FAD. D-Amino-acid oxidase apoprotein has a relatively low Ka (10(6)) for FAD, and benzoate has a relatively high Ka (10(5)) for the enzyme. Therefore, the binding of benzoate increases the tightness of FAD binding to apo-D-amino-acid oxidase (10(11)), indicating significant changes in flavin-protein interactions. In contrast, apo-L-amino-acid oxidase binds flavin tightly (the Ka is greater than 10(7)) and the enzyme binds to anthranilate much less tightly, with a Ka of 10(3). The L-amino-acid oxidase apoprotein binding to FAD is tight initially, and the binding of anthranilate changes it only slightly.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Oxidoreductases↗
PubMed1986

Oxidation-reduction potentials of butyryl-CoA dehydrogenase.

In order to obtain butyryl-CoA dehydrogenase from Megasphaera elsdenii in pure enough form to perform redox studies, the existing purification procedures first had to be modified and clarified [Engel, P. (1981) Methods Enzymol. 71, 359-366]. These modifications are described, and the previously unpublished spectral properties of the electrophoretically pure CoA-free butyryl-CoA dehydrogenase are presented. In our spectral reductive titration of pure enzyme, we show that although blue neutral flavin radical is stabilized in nonquantitative amounts in dithionite titrations (19%) or in electrochemical reductions mediated by methylviologen (5%), it is not thermodynamically stabilized; therefore, only a midpoint potential for butyryl-CoA dehydrogenase is obtained. The electron-transfer behavior from pH 5.5 to pH 7.0 indicates reversible two-electron transfer accompanied by one proton: EFlox + 2e- + H+ = EFlredH- Em7 = -0.079 V vs. SHE where EFlox is oxidized butyryl-CoA dehydrogenase, EFlredH- is two electron reduced enzyme, and Em7 is the midpoint potential at pH 7.0 at 25 degrees C. Redox data and activity data both indicate that the enzyme loses activity rapidly at pH values above 7.0. The Em7 of the butyryl-CoA dehydrogenase is 40 mV positive of the Em7 of the butyryl-CoA/crotonyl-CoA couple [Gustafson, W. G., Feinberg, B. A., & McFarland, J. T. (1986) J. Biol. Chem. 261, 7733-7741]. Binding of substrate analogue acetoacetyl-CoA caused the potential of butyryl-CoA dehydrogenase to shift 100 mV negative of the free enzyme. The negative shift in potential makes electron transfer from enzyme to substrate more probable, which is consistent with the direction of electron transfer in the bacterial system.(ABSTRACT TRUNCATED AT 250 WORDS)

Butyryl-CoA Dehydrogenase↗
PubMed1976

The effect of conditioned stimuli signalling food upon the autochthonous instrumental responses in dogs.

Food CSs, presented (i) concomitantly with SD controlling bar pressing for food, or (ii) on the background of non-discriminated bar pressing (FR 1/15), suppress instrumental performance but elicit undiminished conditioned salivation. This result supports Soltysik-Konorski's model of CNS mechanism controlling food-oriented behavior which postulates drive inhibition by taste-consummatory neurons.

Animals↗
PubMed1975

Single unit activity in basal ganglia of monkeys during performance of a delayed response task.

Single unit activity was recorded from the basal ganglia (caudate, putamen and globus pallidus) of monkeys during the performance of a delayed-response task. The task was divided into five epochs: stimulus onset, delay, pre-response, post-response and reqard. A high percentage of units recorded from the basal ganglia were found to show significant changes in activity during one or more epochs. Examination of the proportion of units excited or inhibited during a particular epoch indicated that brief increases or decreases in unit firing rates occurred "in phase" in both pallidum and caudate. Longer lasting firing rate changes, however, tended to occur in opposite directions in these two structures. This latter finding is interpreted as representing the consequence of persistent increases or decreases in activity of inhibitory interneurons in the caudate nucleus.

Animals↗
PubMed1975

A failure to train the "same-different" differentiation of photic stimuli in dogs.

Dogs were unable to learn "same-different" differentiation of pairs of photic stimuli when continuous light (CL) and pulsing light (PL) were presented in four combinations: CL-PL and PL-CL served as S(D) (positive instrumental conditioned stimulus), whereas CL-CL PL-PL were S delta (inhibitory stimulus). Also the dogs which have learned this task with tones were unable to transfer to photic stimuli. Differentiation of the single stimuli (CL and PL) as S(D) and S(delta) was quite easy and showed that the stimuli were readily discriminable.

Animals↗
PubMed1975

Transfer of the "same-different' differentiation task in dogs.

Four dogs, previously trained to perform on the "same-different" differentiation with tones transfered readily to the same task with new stimuli of the same (auditory) modality. The data are interpreted as an support for the "matching" hypothesis and a disproof of the notion of "conditioned switching".

Animals↗
PubMed1972

The performance of goats in triple choice delayed response tasks.

Goats have been successfully trained in types of triple choice delayed response situations. Their levels of performance indicated that they are able to solve delayed response tasks very successfully and can make correct choices in a post-delay response reward design after delays of 30 min, which is considerably longer than has been previously reported for dogs and cats. Goats do not readily approach and investigate novel stimuli and require a complex compound stimulus in the delayed response situation. They have been shown to be very useful experimental animals in the study of the mechanisms involved in recent memory.

Animals↗