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Biomedical subjects

G T Taylor

Publications and source records attributed to G T Taylor.

61 records · Page 4Linked to original sources
PubMedDate not supplied

The effects of prenatal exposure to methylmercury on aggressive behavior in the rat.

The sensitivity of isolation-induced aggressive behavior to prenatal treatment of 6.0 mg/kg methylmercuric chloride (MMCl) by gavage on gestation days 6-9 was assessed in a subset of animals from the Collaborative Behavioral Teratology Study (CBTS). CBTS behavioral measures consisted of negative geotaxis, olfactory discrimination, auditory startle habituation, 1-hr activity, 23-hr activity, activity following pharmacological challenge and visual discrimination learning. Auditory startle was the only CBTS behavioral measure that discriminated among prenatal treatment groups. MMCl animals also were reliably more aggressive than vehicle controls in dyadic encounters. The results suggest that tests of aggressive behavior, which rarely have been included in teratologic assessments, be considered in the formulation of behavioral screening paradigms. The advantages of including tests of aggression and the relationship between aggressive and startle responses are discussed.

Acoustic Stimulation↗
PubMedDate not supplied

Helix-coil stability constants for the naturally occurring amino acids in water. IX. Glutamic acid parameters from random poly(hydroxybutylglutamine-co-L-glutamic acid).

The synthesis and characterization of water-soluble random copolymers containing L-glutamic acid with N5-(4-hydroxybutyl)-L-glutamine and the thermally induced helix-coil transitions of these copolymers in water and in 0.1 N KCl are described. The incorporation of L-glutamic acid was found to increase the helix content of the polymer at low pH and to decrease it at high pH even though the presence of 0.1 N KCl effectively eliminated the difference between the electrostatic free energies of the helix and the coil. The Zimm-Bragg parameters sigma and s for the helix-coil transition in poly(L-glutamic acid) in water and in 0.1 N KCl were deduced from an analysis of the melting curves of the copolymers in the manner described in earlier papers. The synthesis of N-acetyl-N'-methylglutamic acid amide and its titration, as well as that of the copolymers and poly(L-glutamic acid), in 0.1 N KCl are described.

Butanols↗
PubMedDate not supplied

Helix--coil stability constants for the naturally occurring amino acids in water. X. Tyrosine parameters from random poly(hydroxypropylglutamine-co-L-tyrosine).

The synthesis and characterization of water-soluble random copolymers containing L-tyrosine with N2-(3-hydroxypropyl)-L-glutamine are described, and the thermally induced helix--coil transitions of these copolymers in water have been studied. The incorporation of L-tyrosine was found to increase the helix content of the polymers at all temperatures. The Zimm-Bragg parameters sigma and sigma for the helix--coil transition in poly(L-tyrosine) in water were deduced from an analysis of the melting curves of the copolymers in the manner described in earlier papers. The large value of sigma indicates that, in water, tyrosine has a tendency to promote helix--coil boundaries at all temperatures; the values of sigma indicate that this residue enhances helix growth at low temperature and reduces it at high temperature.

Circular Dichroism↗
PubMedDate not supplied

Helix-coil stability constants for the naturally occurring amino acids in water. 11. Lysine parameters from random poly(hydroxybutylglutamine-co-L-lysine).

The synthesis and characterization of water-soluble random copolymers containing L-lysine with N5-(4-hydroxybutyl)-L-glutamine, and the thermally induced helix-coil transitions of these copolymers in water, are described. The incorporation of L-lysine was found to decrease the helix content of the polymers at neutral pH. The Zimm-Bragg parameters sigma and s for the helix-coil transition in poly(L-lysine) in water were deduced from an analysis of the melting curves in the manner described in earlier papers. The computed values of s indicate that, in the temperature range of 0-60 degrees C, lysine has a tendency to destabilize helical sequences, this tendency being minimal at approximately 25 degrees C and increasing at lower and higher temperatures.

Calorimetry↗