A study of the sulphur amino acids of rat tissues

1. In a study of the metabolism of l-[(35)S]methionine in vivo, the labelled sulphur compounds of rat liver and brain were separated first by ion-exchange chromatography into two fractions containing (i) free sulphur amino acids such as methionine, cystathionine, cyst(e)ine and homocyst(e)ine and (ii) glutathione. 2. Two-dimensional paper chromatography with butan-1-ol-acetic acid or propionic acid-water in the first direction and 80% acetone or acetone-ethyl methyl ketone-water in the second direction was found superior to other solvent systems for separating the sulphur amino acids. 3. At 10min. after injection of [(35)S]methionine only a small part of the (35)S was found combined in free methionine or other free sulphur amino acids. 4. Evidence was obtained of the presence of adenosyl[(35)S]methionine and adenosyl[(35)S]homocysteine in perchloric acid extracts of rat liver and brain. 5. The trans-sulphuration pathway was active in brain as well as in liver.     

The origin of lift forces in fluttering flight

A two-dimensional nonlinear integro-differential equation with time-varying coefficients describing the behavior of the fluttering wing-body systems typical of natural flight mechanisms has been deduced from the Navier-Stokes equation which generalizes local pressure and velocity distributions in the externally oscillating air field. The resulting equation for the wing forces is combined with an analogous expression for the forces of gravitation and acceleration associated with the body. The air acceleration force, not previously considered in bio-physical models of insect and bird flight, is shown to arise from a formal analysis of unsteady or time-varying contributions to the velocity field, while the square form of the conventional steady state aerodynamic forces is derived from the intertial terms in the Navier-Stokes equation with the aid of the approximations of Newtonian impact theory. Previous calculations (Houghton, 1964) have indicated that the contribution to gravitational stability of air acceleration and aerodynamic life are roughly in the ratio of 3:1.     

Some further comments on the DNA-protein coding problem: A correction and a note

An error appearing in the proof of Theorem 4 of a previous paper of the author’s (1959,Bull. Math. Biophysics,21, 289–97) is pointed out, and a new proof of the theorem is supplied. We also obtain a corollary from Theorem 3 ofloc. cit. which reveals the existence of a hitherto unrecognized class of codes.     

THE INTERSEXED PATIENT

There are at present two opposing points of view on problems of dealing with the intersexed patient (not the typical homosexual or transvestite) who has clearcut anatomical or biochemical qualities of the opposite sex. The first is that in the growing child or adult coming for treatment, the sex the patient should adopt is the summation of somatic sex. The other is that the sex role should be assigned according to the predominant psychological identification already present.A case history of a middle-aged pseudohermaphrodite, castrated in youth but raised from birth as a female and living thus in “homosexual” relations with women until examined and interviewed at UCLA Medical Center is presented to illustrate the psychological problems in sexual identity with which the patient had to cope.Psychiatric investigation revealed how confused the patient''s sex identity was until treatment by a team consisting of psychiatrist, psychologist and endocrinologist permitted the patient, even at so late a date, finally to establish what his gender is. The patient was able, despite early rearing as a female and a castrating operation, to swing to a more masculine identification. This was possible because of some uncertainty of sexual role from an early age.