A case with both hemoglobins C and N-Baltimore

Hemoglobins C and N-Baltimore were detected in a 75-year-old black man. Although mild anemia and abnormal erythrocyte morphology resembling thalassemia were present, detection of this combination of hemoglobins at an advanced age suggests that it does not limit normal activities.

Regulation of phenylalanine ammonia-lyase synthesis by cinnamic acid. Its implication for the light mediated regulation of the enzyme

1. There is an increase in the extractable acitivity of phenylalanine ammonia-lyase following excision of hypocotyl segments of dark-grown gherkin seedlings This increase is prevented by the reaction product, cinnamin acid. 2. Density-labelling experiments show that cinnamic acid affects the rate of enzyme synthesis. By contrast the regulation of phenylalanine ammonia-lyase activity by light has previously been shown to involve activation of existing inactive enzyme. 3. It is proposed that regulation of synthesis by reaction products represents a mechanism for controlling the size of the pool of phenylalanine ammonia-lyase, and that the activity of this pool is regulated by light.

Advantages of the fixed-angle rotor for the separation of density-labelled from unlabelled proteins by isopycnic equilibrium centrifugation

A comparison has been made between the swinging-buckets rotor and the fixed-angle rotor for density-labelling experiments. The enzymes examined were beta-galactosidase (beta-D-galactoside galactohydrolase, EC 3.2.1.23), L-phenylalanine ammonia-lyase (EC 4.3.1.5) and acid phosphatase (orthophosphoric monoester phosphohydrolase, EC 3.1.3.2); it was found that the fixed-angle rotor offered greater separation and resolution and shorter equilibration times compared with the swinging-buckets rotor at the same angular velocity. By exploiting the greater flexibility offered by the fixed-angle rotor it is possible to obtain either a 6-fold improvement in separation or a 6-fold reduction in equilibration time. The significance of these results for density-labelling work is discussed.

Social structure of the squirrel monkey (Saimiri sciureus, Iquitos): relationships among behavior, heartrate, and physical distance

The relationships between heartrate, behavior, and physical distance were assessed in squirrel monkeys forming a stable colony. For many specific behaviors, heartrate is elevated from baseline 2 min before the behavior and depressed afterwards. Heartrate during a specific behavior is often related to rank by either a U or inverted U: high and low ranking animals show similar heartrates but those of midranking animals are depressed or elevated. The findings are interpreted in terms of the possible evolutional effects on endocrine output of long- and short-term stress.

Skin virilism in women with hrsutism

Thirteen hirsute women were studied and found to have significantly increased mean rates of sweat and sebum excretion and plasma testosterone concentration compared with control women. These same patients had previously been shown to have an increased total skin collagen content. These findings suggest that the whole skin is virilized in hirsutism. This may be the result of cutaneous androgen synthesis.