Analysis of the sexual dimorphism in the basioccipital portion of the dog's skull

Sexual differences in the basioccipital portion of the skull of dogs have been described and an index is presented which reliably predicts the sex of the skull. 92 dolichocephalic skull (44 male, 48 female) from mongrel dogs were used. In the basioccipital region of the male skulls, a triangular area, which extends from the basion to a line joining the medialmost points of the two jugular foramina, appears narrow and elevated. The pharyngeal tubercle is also prominent. In female skulls the rostral angle of this triangle is wider and the triangular area seems smoother and flat. The anterior half of the female basioccipital portion is wider and smoother than in the male skull. In order to quantify the observed differences, four indices were calculated. All of the indices were statistically significant. However, only index IV could be reliably used in predicting the sex of an unknown skull: (formula: see text) was derived from breadth IV (distance between the two temporo-occipital fissures at their lateralmost points) and length II (distance between the basion and a line drawn between the two medialmost points of the jugular foramina in the midline). Values of less than 123 for male and greater than 136 for female placed the skulls in their proper sex group. Skulls that had intermediate values could be placed in correct sex grouping only in conjunction with strong observational criteria. It is suggested that in absence of such strong observational criteria these skulls may belong to immature or castrate animals.

Effect of ageing of serum on consumption of antibody by beta-1C-globulin determinants; evidence for circulating breakdown products in glomerulonephritis

Changes in antibody consumption by the A and D determinants of β_1C-globulin were found to increase as serum aged in vitro. Consumption by the A determinant was 1·6 times and by the D determinant, 2·5–3 times greater in aged serum than in fresh EDTA plasma. The most likely explanation for the increased consumption with ageing is steric changes occurring as the β_1C molecule fragments into β_1A and α_2D, resulting in exposure of additional antibody combining sites. In specimens from patients with hypocomplementemic nephritis, the increase in consumption with ageing was less than in normal subjects. The data add to the evidence presented in earlier studies of the presence in vivo, in certain nephritics, of breakdown products of β_1C-globulin. The most abundant breakdown product would be α_2D-globulin.

Evidence for in vivo breakdown of beta-10-globulin in hypocomplementemic glomerulonephritis

Evidence has been obtained for the presence in vivo of alpha(2D)-globulin, a breakdown product of serum beta(1C)-globulin, in patients with acute and persistent hypocomplementemic glomerulonephritis. The protein has been identified by immunoelectrophoretic analysis, and the amounts present have been determined by direct measurement of specific antigenic determinants present on alpha(2D). beta(1A)-Globulin, another breakdown product of beta(1C)-globulin, may also be present in vivo in severely hypocomplementemic patients, but its levels are much lower than those of alpha(2D)-globulin.Alpha(2D)-globulin has been identified by immunoelectrophoretic analysis of fresh EDTA plasma from patients with hypocomplementemic nephritis as an arc in the alpha(2) region that shows a reaction of identity with the arc representing alpha(2D)-globulin produced by aged normal serum. beta(1A)-Globulin was not seen in these patterns. Measurement of specific antigenic determinants has been carried out in both fresh EDTA plasma and aged serum. In the fresh plasma, the concentration of D antigen, found on both beta(1C)- and alpha(2D)-globulins, has been related to that of B antigen, found only on beta(1C) and taken as a measure of the concentration of this protein. In the hypocomplementemic patients, the concentration of D antigen, in comparison to that of B, was greater than in the normal subjects. Similarly, in aged serum, the level of alpha(2D) was greater than would be expected from the amount of beta(1C) that had been broken down in vitro, measured by the concentration of beta(1A). Calculations indicated that the in vivo alpha(2D) level in severely hypocomplementemic patients ranged from 7.5 to 18% of that which would be found in a pool of aged normal serum in which beta(1C) is completely broken down. The levels tended to be lower in less severely hypocomplementemic patients, and none could be detected in normal plasma. Only small quantities of A and D antigens are detectable in the urine of patients with hypocomplementemic nephritis. The rate of excretion is about equal to that of the normal subject. The study indicates that the low serum levels of beta(1C)-globulin that may be present over long periods in patients with persistent hypocomplementemic glomerulonephritis can be ascribed, in part, to in vivo breakdown of this protein as a result of reaction with immune complexes. The contribution of beta(1C) deposition on immune complexes and of diminished synthesis to the depressed serum levels cannot be assessed by the present study.