The use of a free flap in homozygous sickle cell disease

This paper describes what is thought to be the first reported use of a free flap in a patient with homozygous sickle cell disease. The utilization of a free flap in homozygous sickle cell disease should be questioned because the obligate period of ischemia to which the flap must be subjected during the transfer from donor to recipient sites might lead to intravascular sickling in the flap and flap failure. Review of the literature suggests that by reducing the level of sickle hemoglobin to the range of 25 to 40 percent, the risk of failure of a free flap is not significantly increased in the homozygous sickle cell patient. Furthermore, there is good evidence to suggest that a well-vascularized muscle flap provides optimal coverage, reversing the pathophysiologic cycle of the sickle cell ulcer. Thus in cases of multiply recurrent sickle cell ulcers in areas devoid of a local well-vascularized muscle flap, a free muscle flap is indicated, may be the procedure of choice, and can be performed successfully. We report a patient with a 4-year history of multiple recurrent sickle cell ulcers of the left ankle treated with a gracilis free flap. This patient has been followed for 2 years and continues to be free of recurrent ulceration.     

Isolation and characterization of a protein neurotoxin from the venom glands of the funnel-web spider (Atrax robustus)

1. Ground venom glands from male and female funnel-web spiders (Atrax robustus) were extracted with acetic acid (0.35 M). 2. A protein constituent of these extracts, atraxin, which caused muscle fasciculation when applied to the phrenic nerve-hemidiaphragm of the mouse in vitro, was isolated by the sequential application of ultrafiltration, gel permeation and ion exchange chromatography. 3. When subjected to isoelectricfocusing, amino acid analysis, ultracentrifugation, ultraviolet and 1H nuclear magnetic resonance spectroscopy, it was shown that atraxin had an approximate molecular weight of 9800, an isoelectric point of greater than 9 and that it contained 76 amino acid residues.