PADGEM (GMP140) is a component of Weibel-Palade bodies of human endothelial cells

PADGEM protein (PADGEM), also known as GMP140, is a platelet alpha- granule membrane protein that is translocated to the external membrane after platelet activation. Although the biosynthesis of this protein was originally thought to be confined to megakaryocytes, the synthesis of PADGEM in endothelial cells was recently demonstrated (McEver et al: Blood 70:1974a, 1987). We now describe the subcellular localization of this protein in endothelial cells. Immunofluorescence staining of permeabilized human umbilical vein endothelial cells with KC4, a well characterized monoclonal antibody to PADGEM, showed positively stained elongated structures similar in distribution and shape to Weibel-Palade bodies. Their identity as Weibel-Palade bodies was confirmed by double label immunofluorescence using KC4 and a polyclonal antiserum to von Willebrand factor (vWf), a protein known to be specifically stored in these organelles. All Weibel-Palade bodies were found to contain PADGEM. In contrast to strong perinuclear staining produced with anti- vWf antibodies, no significant perinuclear staining was obtained with KC4, indicating that relatively little PADGEM is present in the endoplasmic reticulum and in the Golgi apparatus. In endothelial cells treated with secretagogues that stimulate vWf release the elongated structures positive for PADGEM disappeared, further identifying these structures as Weibel-Palade bodies. This observation extends the parallels between Weibel-Palade bodies and alpha-granules and suggests a possible functional association between vWf and PADGEM.     

BUILDING THE FOUNDATION OF EXCELLENCE IN HEART FAILURE NURSING

This column contains the presidential address presented during the Third Annual Meeting of the American Association of Heart Failure Nurses on June 28, 2007, in San Diego, California, titled "Building the Foundation of Excellence in Heart Failure Nursing."     

The effect of omitting botulinum toxin from the lower eyelid in blepharospasm treatment

We randomly selected 26 patients with essential blepharospasm to receive either botulinum toxin or saline injection in their lower eyelids to evaluate the necessity of lower eyelid injection to relieve blepharospasm. As diplopia may occur from botulinum toxin injections for blepharospasm, most commonly from injection of the lower eyelid, and surgical relief of blepharospasm is often achieved by excision of only the upper eyelid protractors, omission of toxin from the lower eyelid seemed both desirable and possible. All patients received botulinum toxin in the upper eyelids, above the eyebrows, across the glabella, and near the lateral canthus. Thirteen of 15 patients who received saline in their lower eyelids had relief of spasm, with the same spasm-free interval as those who received toxin. We recommend avoiding injection of toxin in the medial two thirds of the lower eyelid in order to diminish the likelihood of diplopia from inferior oblique muscle paresis.     

Preliminary Evaluation of Sexual Problems in Combat Veterans with PTSD

This study evaluated the potential relationship between posttraumatic stress disorder (PTSD) and sexual problems. The Golombok Rust Inventory of Sexual Satisfaction was mailed to combat veterans currently in treatment at an outpatient PTSD clinic. Completed questionnaires were received from 90 patients. Results indicated that over 80% of subjects were experiencing clinically relevant sexual difficulties. Impotence and premature ejaculation were the most frequently reported problems that have corresponding psychological diagnoses. The rates of sexual problems for this sample of veterans with PTSD was similar to those reported in other studies and exceeded rates of similar problems found in samples from community samples. These data suggest mat PTSD may be a risk factor for sexual problems.