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Biomedical subjects

R Stupnicki

Publications and source records attributed to R Stupnicki.

At least 19 recordsLinked to original sources
PubMed1992

Glucocorticoid response to exercise as measured by serum and salivary cortisol.

Serum and salivary cortisol concentrations were studied in 78 elite athletes engaged in different sports, by subjecting them to high-intensity laboratory exercise. The mean difference in the pre-exercise cortisol concentrations in the seven groups studied were more marked in serum (from 311 to 768 nmol.l-1) than in saliva (from 17.9 to 22.7 nmol.l-1, only one group reaching 40 nmol.l-1). Judging from the correlation coefficients based on total variances, the post-/pre-exercise differences in cortisol concentrations in serum depended chiefly on pre-exercise values, while those in saliva tended to depend more on the postexercise concentrations. The coefficients of correlation between that difference and either the pre- or postexercise values were -0.71 and 0.47, respectively, for serum, and -0.51 and 0.58, respectively, for saliva. This would suggest that salivary cortisol concentration might be a more suitable variable for assessing glucocorticoid activity in exercise than serum cortisol concentration, probably being less sensitive to pre-exercise emotional state.

Adolescent↗
PubMed1991

Radioimmunoassay of cortisol in saliva.

A direct (without extraction) radioimmunoassay of cortisol in saliva has been developed. The samples of saliva were subjected to four freezing-thawing cycles in order to decrease viscosity which may interfere with the determination. The method is simple, has good specificity and reproducibility. The determination in saliva has also the merit of noninvasiveness, and besides, the level of cortisol in saliva reflects the free, biologically active fraction of the hormone in blood serum. The volume of saliva required does not exceed 25 microliters per tube and the range of concentrations is between 0.6 and 15 nanograms per milliliter (1.5-40 nmol/l).

Charcoal↗
PubMed1987

HME--a novel derivative for direct iodination in steroid radioimmunoassays.

Steroid derivatives containing histidine methyl ester (HME), instead of histamine, were prepared by mixed anhydride coupling. The derivatives were crystalline, and when labelled in microgram quantities by using Iodo-gen (exposure time 1 h) the yield of the immunoreactive fraction was 40-50%. The products were similar in immunoreactivity and stability to the known histamine derivatives. Assay parameters obtained with HME-derivatives were compared with those obtained with tritiated steroids and with analogous TME-derivatives. A heterologous assay of progesterone (3 antisera against 12 alpha-succinyl-BSA, and methylsuccinyl derivatives for labelling substituted at 11 alpha-position), and a homologous assay of cortisol (4 antisera against 21-succinyl-BSA, and 21-carbonyl-derivatives for labelling) were studied. The HME-derivatives produced logit-log curves with slopes comparable to those in tritium-based assays. The sensitivity, as expressed by ED50 values, was by 66% higher than in tritium assays, and by 50% higher than for the tyramine derivative in a similar heterologous assay. The HME-based assay for cortisol was by 26% less sensitive compared to tritium, but several times more sensitive than in case of analogous TME-based assay.

Histidine↗
PubMed1976

Radioimmunoassay of LH in blood plasma of farm animals.

A radioimmunoassay technique has been developed for measuring LH in blood plasma of cattle, sheep and pigs, by using an antiserum against bovine LH. Either ovine or bovine LH could be used for labelling and calibration curves in case of these two species, while porcine LH was to be taken in case of pigs. Working range of the calibration curve was 0.3 to 20 ng/ml. The between-assay error ranged from 17 to 7.5% between 1 to 5 ng/ml, the within-assay error from 10 to 4%, respectively. A system of quality control of the assay was developed, based on a series of pretested sera by using the chi-square function.

Animals↗
PubMed1976

Binding of testosterone in mouse plasma.

The binding of testosterone (T) in the plasma of adult male mice was examined using florisil absorption. The binding decreased as the temperature of incubation increased, and was substantially reduced by preheating the plasma at 75 degrees C. The addition of an excess of cold T did not displace 3H-T, and the binding did not depend on the concentration of endogenous T in the plasma. It appears that, under physiological conditions, approximately 60% of the T present in the peripheral circulation of male mice is bound to plasma components, probably mostly to albumin.

Animals↗
PubMed1975

The effects of CBG on the in vitro reduction of 3H-progesterone by liver homogenates and cell suspensions.

The effects of CBG on 3H-progesterone metabolism by ovine, bovine and rat liver homogenates and bovine and rat liver cell suspensions were studied. As a source of CBG served plasma from "estrogenized" women. Same plasma, pretreated at 60 degree for 20 min. served as control. It was found that the amounts of 3H-progesterone remaining after incubation were higher in the presence of CBG, as compared with control incubations, when using the homogenates. No such effect was observed in case of cell suspensions.

Animals↗
PubMed1975

Direct radioimmunoassay of progesterone in plasma of farm animals.

A radioimmunoassay technique has been developed for measuring progesterone directly, without extraction, in 20-mul-aliquots of plasma. The assay was performed in disposable polystyrene test-tubes. Working range of the calibration curve was 0.3 to 10 ng/ml, the precision rangin from 30 to 6%, respectively. The results obtained by the presented method are fully comparable to those reported by others. This method has been applied to farm animals, but is also applicable to other species whose plasma has a low affinity for progesterone.

Animals↗
PubMed1975

Plasma levels of LH and prolactin in cows following enucleation of the persistent corpus luteum.

LH and prolactin were measured in plasma of 5 cows before and after enucleation of the persistent corpus luteum. Two cows returned to normal oestrous cycles following enucleation and did not differ from normal, cycling cows, with respect to hormone levels. Three other ones developed follicular cysts following enucleation and had decreased levels of LH and prolaction as compared with cycling cows. On the day of enucleation the fluctuations in LH-levels were higher than either before or after enucleation.

Animals↗
PubMed1975

Peripheral plasma levels of lh in the cow throughout the estrous cycle.

Peripheral plasma levels of LH during the bovine estrous cycle were measured in 5 cows and one heifer by using double antibody radioimmunoassay. The sources of variability of basal LH-levels were analyzed in detail. The range of basal levels of LH WAS 0.3--3.5 Ng/ml. Between days 11 and 14 of the cycle the mean daily levels were lower in all cows by about 28% as compared with the remaining parts of the cycle. This did not seem to be directly influenced by changes in progesterone levels. A single peak of LH was observed around estrus. The magnitude of that preovulatory peak varied from 6.7 to 16.0 mg/ml, and lasted only a few hours.

Analysis of Variance↗