A case of aspartate aminotransferase macroenzyme.

Aspartate aminotransferase (AST) macroenzyme can result in elevated AST activity in patients with no disease. This case report describes a six-year-old boy who presented to his family doctor with a history of chronic constipation and lower back pain. Routine blood tests showed normal creatine kinase activity (CK), normal alanine aminotransferase activity (ALT) but raised AST.

Effect of time of day and rabbit strain on patterns of aortic wall permeability.

Lipid deposits occur more frequently downstream of branch points than upstream in immature rabbit and human aortas but the opposite pattern is seen in mature vessels. These distributions correlate spatially with age-related patterns of aortic permeability, observed in rabbits, and may be determined by them. The mature but not the immature pattern of permeability is dependent on endogenous nitric oxide synthesis.

Two-dimensional maps of short-term albumin uptake by the immature and mature rabbit aortic wall around branch points.

In children, aortic lipid deposition develops in triangular regions of the wall downstream of branch points, whilst in adults these regions are particularly free of disease. Comparable age-related patterns occur in rabbit aortas. They may be explained by patterns of wall permeability to circulating macromolecules: along the longitudinal midline through branches, permeability is greater downstream than upstream in immature rabbits, but is greater upstream at later ages.

Effect of altered flow on the pattern of permeability around rabbit aortic branches.

Uptake of circulating macromolecules by the aortic wall is greater downstream than upstream of branch sites in immature rabbits, but the opposite pattern is seen at later ages. The mature pattern is nitric oxide dependent; we tested whether it is also flow dependent. Intercostal arteries of anesthetized rabbits were occluded, sham operated, or left alone.