The genetics of palmar creases. A study in the inheritance of liability estimated from the incidence among relatives

Six-hundred and fifty-nine Chinese children and 613 first degree relatives were studied with regard to four variations in the palmar creases: the simian crease, the Sydney line, the radial border termination of the thenar crease, and the distal border termination of the distal crease. With the exception of the Sydney line, these palmar crease variations were found to occur with significantly increased frequency in the parents of the propositi compared with 400 controls, indicating the presence of genetic factors in their embryogenesis. If the polygenic hypothesis is accepted, the very high heritability of liability (100%) to the radial border termination of the thenar crease is a further demonstration of the importance of the genetic contribution. Variations in the palmar creases thus cannot be totally explained away by early flexional folding in the skin of the developing hand.

Role of adipose tissue in free fatty acid metabolism in hemorrhagic hypotension and shock

This study was designed to observe the effects of hemmorrhage on the mobilization of free fatty acids from adipose tissue under a variety of experimental conditions. Experiments were conducted in fasting rabbits and dogs. A significant fall in arterial plasma free fatty acids was observed in rabbits following hemorrhage of 4 ml every 2 min and after inducing acute hemmorrhaged to a mean arterial blood pressure of 40 mm mercury. Adipose-tissue free fatty acids and arterial-plasma free fatty acids were simulatneously measured before and after hemorrhagic hypotension until death. Afterial free fatty acids fell significantly following hemorrhage, while the concentration of adipose-tissue free fatty acids rose significantly. In the next series of experiiments, dogs were pretreated with an alpha-receptor blocking agent phenoxybenzamine and acutely hemorrhaged. The results showed a significant rise in arterial free fatty acids concentration and an insignificant increase in adipose-tissue free fatty acids. These results suggest that hypoperfusion of adipose tissue plays an important role in the decreased supply of a major body fuel following hemorrhagic hypotension. The results are compatible with the view that metabolic fuel failure may be an important factor in the development of the complications of acute hemorrhage and suggest the concept that adipose tissue may be an important target organ in hemorrhagic shock.