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Biomedical subjects

M Pasić

Publications and source records attributed to M Pasić.

At least 19 recordsLinked to original sources
PubMed1992

Characteristics of outward current induced by application of dopamine on a snail neuron.

1. A closer characterization of the potassium channel opened by the application of dopamine (DA) on an identified Helix pomatia neuron was attempted. The effect of K+ channel blockers (TEA and 4-AP) on the DA-induced current was examined. The results indicate that the channel opened by DA does not share the pharmacological properties of other snail neuron K-channels. 2. The I-V relation for IDA was successfully fitted by the Constant Field equation except below the reversal potential where the current was smaller than expected. The assumption that DA binding is voltage-sensitive is supported by the increment of the Hill coefficient with hyperpolarization (from nH approximately equal to 1 to nH approximately equal to 2). 3. The presence of the phosphodiesterase inhibitor IBMX does not affect the DA induced outward current. However, the assumption that the snail neurons' DA receptor belongs to the D2 class is in contrast to the antagonistic effects of ergot alkaloids which, in mammalian neurons, are competitive antagonists of D1 receptors. 4. The examination of the voltage-sensitivity of the blocking action of the ergot alkaloid (Bromoergocryptinine) revealed that it does not compete with DA for the same binding site as in mammalian D1 receptors.

Animals↗
PubMed1989

[Axillo-femoral bypass--an emergency operation].

Our patient with peritonitis, chronical ileus and ileostoma has had the atherosclerotic occlusive changes in aorto-iliac area on both sides. Hypotensive crises must have made hemodynamic conditions worse, permitting thrombosis in the collateral circulation to cause acute ischemia of the right leg. Because of the bad general condition and infection on the anterior abdomen wall, the axillo-femoral bypass has been the only way for the arterial reconstruction and salvation of the leg.

Acute Disease↗
PubMed1988

A modified nitrite test as a screening test for significant bacteriuria.

The presence of nitrite was initially assessed in 306 specimens of urine. If the initial result was negative a sample of urine was incubated at 37 degrees C. The other portion was also incubated but with the addition of one drop of 1% NaNO3, and the nitrite test was then repeated. The results were correlated with the results of quantitative routine urine culture. The modified test significantly (P less than 0.01) improved the sensitivity (93% v 21%), and the predictive negative value (97% v 80%).

Bacteriuria↗
PubMed1987

Interaction between some ergot alkaloids and the reactivity to dopamine of an identified neurone of Helix pomatia.

The effect of ergot alkaloids, some of them from the ergosine series, was tested on the response of an identified neurone of Helix pomatia to the application of dopamine (DA) which was membrane hyperpolarization (DA-I response). To evaluate the antagonistic potency of the ergot alkaloids, the dose-response relationship of the response to DA was established first in the absence and later in the presence of the tested compound. The sigmoidal dose-response curves obtained were used to determine the pA2 values of all the antagonists tested. Comparing them it was found that among the ergosines tested, the most potent was dihydroergosine, its pA2 value being (6.27) similar to the values obtained for dihydroergotoxine (6.66) and dihydroergotamine (6.36). The two other unhydrogenated compounds (ergosine and saccharinoergosine) had potencies of the same order as bromoergocryptine. The D-isomer (+) of the saccharino compound was the least potent, but it acted as a DA-receptor antagonists, as well as the dextroisomer of bromoergocryptine, bromoergocryptinine. By comparing the current-voltage relationship of the neurone in the presence and absence of the ergot alkaloids tested it was found that they had no non-specific effects on the membrane. The ergot alkaloids did not change the amplitude of depolarization of the neurone induced by gamma-aminobutyric acid (GABA) and acetylcholine (ACh).

Animals↗