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Biomedical subjects

K Kowalski

Publications and source records attributed to K Kowalski.

88 records · Page 5Linked to original sources
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Synthesis of CpFe(CO)(L) complexes of hydantoin anions (Cp = eta5-C5H5, L = CO, PPh3), and the use of the 5,5-diphenylhydantoin anion complexes as tracers in the nonisotopic immunoassay CMIA of this antiepileptic drug.

As part of our ongoing development of the CMIA nonisotopic immunoassay method, in which the tracers are metal carbonyl complexes and detection is by Fourier transform infrared spectroscopy, we examined the potential use as tracers of the complexes CpFe(CO)2(5,5-diphenylhydantoin) 2d and CpFe(CO)(PPh3)(5, 5-diphenylhydantoin) 3. The present study involved the synthesis of a series of hydantoin complexes (2a-2d), in particular that of the derivative of 5,5-diphenylhydantoin 2d. The structure of 2d was confirmed by X-ray crystallography. The infrared analysis, establishing the position and intensity of the characteristic metal-carbonyl peaks of complexes 2d and 3 in the 1850-2200 cm-1 region, shows that measurement of the absorbance values of these characteristic peaks will permit quantitative analysis in the picomole range, the norm for routine use in immunoassay and thus suitable for use as CMIA tracers. Cross-reaction rates of these tracers with anti-DPH specific antibodies show that 2d and 3 are both recognized by anti-DPH antibodies (cross-reaction rates 43 and 20%, respectively). In developing a CMIA of DPH with these tracers, it was found that 3, with a single, intense band at 1977 cm-1, had very promising IR characteristics for use in multiassay CMIA, but probably owing to its relatively weak affinity for the antibodies, it was not possible to develop a CMIA for DPH using this tracer. Complex 2d, however, showed better recognition by the antibodies, and using this complex as a tracer, it was possible to develop a particularly sensitive monoassay of DPH by the CMIA method.

Anions↗
PubMedDate not supplied

Smoking behaviour and dietary restraint in young adolescent women: the role of physical self-perceptions.

OBJECTIVE: To investigate the relationship among BMI, smoking consumption, dietary restraint, smoking to control weight, physical self-perception and self-esteem in young female adolescents. METHODS: 702 grade 9 students (14-15 yrs old) completed self-reported validated measures in classroom settings. RESULTS: 26.7% of students had smoked in the last 30 days. Cigarette consumption was low with only 13% smoking one or more cigarettes a day. MANOVA revealed smokers had higher dietary restraint and lower perceptions of physical appearance, conditioning, and self-esteem. A similar pattern emerged for those girls classified as using smoking to control weight. Multiple regression found dietary restraint was predicted by higher BMI, and lower body appearance and self-esteem. CONCLUSIONS: The data provided converging evidence that girls with low self-perceptions are more likely to engage in health-compromising behaviours. Smoking behaviours and dietary restraint were also linked. However, the small effect sizes for smoking behaviours warrants caution.

Adolescent↗
PubMedDate not supplied

Pharmacokinetics of disopyramide in the dog. Importance of mono-N-dealkylated metabolite kinetics in assessing pharmacokinetic modeling of the parent drug.

The antiarrhythmic drug disopyramide (DP) is metabolized to the mono-N-dealkylated compound (MND) and to the pyrrolidone derivative (PYR). This study examines the detailed pharmacokinetic characteristics of DP and MND when given simultaneously or separately to dogs. DP and MND were both relatively well absorbed and showed similar pharmacokinetic characteristics. However, the amount of PYR relative to MND as judged by the area under the plasma concentration-time curves (AUC) following oral or iv administration was much greater with DP than with MND. These findings were also supported by the urinary excretion values where the PYR/MND ratio with DP was much greater than with the MND administration. For an explanation of this phenomenon, plasma concentration-time curves for DP, MND, and PYR were simultaneously analyzed assuming various pharmacokinetic models. The plasma levels of these compounds were best described when nonlinear kinetics were assumed for conversion of MND to PYR.

Absorption↗
PubMedDate not supplied

Spatial analysis of motor unit potentials of the rat medial gastrocnemius.

The spatial analysis of the potentials of single motor units of the rat medial gastrocnemius muscle evoked by stimulation of the fibres of split ventral roots was carried out with a bipolar electrode moving in the direction perpendicular to the longitudinal axis of the muscle fibres. During this movement of the electrode a variability was observed in the time of the biphasic potential from its maximum to minimum, and in the peak-to-peak amplitude of these potentials. The potentials recorded outside the territory of the motor unit had a lower amplitude in relation to the potentials from the territory of the unit. This made localization of the motor unit on the cross-section of the muscle possible. Differences in the duration of the potential from maximal to minimal amplitude (maximum-minimum amplitude time--M-MAT) of each investigated motor unit from successive recording sites reflected the number of fibres contributing to the action potential and the distance of the recording surface of the electrode from the zone of the motor end-plates of this motor unit. The greatest diameter of the territory of the observed motor units reached 2.5 mm.

Action Potentials↗