Disparities In Weight Research Articles

Childhood leukemia in California-born twins.

In a study of the childhood leukemia experience in a California twin birth cohort, there was an apparent deficit of leukemia in twins compared to the occurrence in single births. The rough estimate of the deficit of leukemia in monozygotic twins tends to confirm that found in 2 other studies. The concordance rate for monozygotic twins was estimated to be 25%, which is in agreement with that made by MacMahon and Levy. Relative to the comparison group, the leukemic twins and their unaffected co-twins had a significantly greater disparity in birth weights, and heavy leukemic females made the greatest contribution to this result. More first-born twins died of leukemia than second-born, but an independent twin birth order effect was not shown when birth weight and sex composition were controlled.

Correcting for cell tilt caused by differential expansion of rotors in the analytical ultracentrifuge

Because there is a difference in the weight applied against the top and bottom of its cell hole, an analytical rotor expands differentially. This differential expansion causes the cell to tilt so that light enters the solution at various angles to the normal. Two procedures for dealing with cell tilt are described: the first eliminates cell tilt by correcting the disparity in weight; the second compensates for cell tilt by repositioning the light source.

Soyin, a toxic protein from the soybean: II. Physical characterization

Summary A procedure is described for the preparation of soyin from defatted soybean flour. The following physical constants have been provisionally established: isoelectric point, 6.1; diffusion constant ( D 20 ), 5.72 × 10 −7 sq. cm./sec.; sedimentation constant ( s 20 ), 6.4 × 10 −13 sec.; molecular weight, 105,000; frictional ratio ( f/f 0 ), 1.19. The molecular weight calculated on the basis of light-scattering measurements gave the somewhat lower value of 89,000. This disparity in molecular weights is presumably due to the presence of a small amount of a low-molecular impurity which was apparent in the sedimentation studies but could not be detected by electrophoretic or diffusion techniques.

Inhibition of Somatic Growth in Castrate Rats with Pituitary Extracts.

Male and female rats were castrated when 22-23 days old, and! intraperitoneal injections of adrenocorticotropic extracts (A-C-T) were given daily beginning on the day following the operation. The growth of hair over the shaved operative areas and over the whole body was very greatly retarded in the animals given large amounts∗ of A-C-T. There was retardation and almost complete inhibition of somatic growth when a high level of A-C-T was administered. There was a noticeable protrusion of the abdomen of the animals treated with the higher levels of A-C-T (42.0 + 42.2 units). At autopsy the abdominal viscera of the injected animals appeared to be as large as those of the untreated spayed rats in spite of the disparity in body weight. The weights of the various organs were taken in the rats treated with 42.2 units of A-C-T, in the control spayed rats and in 23-day-old normal female rats. There had been no inhibition in the growth of the spleen and kidney, and only a slight inhibition (?) in the growth of the liver and digestive tract of the treated rats. The heart and thyroids were considerably smaller than in the untreated spayed animals. The pre-putials were enlarged in the injected animals. The thymus was very atrophic and in some cases completely atrophied.