Publications

Anti-Tac monoclonal antibody has been identified as a putative antibody against the receptor for T-cell growth factor (TCGF). We now show that: (i) TCGF blocks 85% of 3H-labeled anti-Tac binding to phytohemagglutinin-activated lymphoblasts and (ii) both anti-Tac and anti-TCGF immunoprecipitate a protein band that appears to represent TCGF crosslinked to its receptor on HUT-102B2 cells. In HUT-102B2 cells, the TCGF receptor is a Mr 50,000 glycoprotein with internal disulfide bond(s) and a pI of 5.5-6.0, and it represents approximately equal to 0.05% of total cellular de novo protein synthesis. It contains a peptide of Mr 33,000 that is processed to a mature form that includes N-linked and O-linked sugars and sialic acid.

Objective data on the reliability of precordial palpation in detecting left ventricular enlargement are scarce. Therefore, we evaluated 41 patients by physical examination and two-dimensional echocardiography to determine the relation between the location of the apex and left ventricular end-diastolic volume. An apical impulse lateral to the mid-clavicular line or greater than 10 cm from the mid-sternal line was sensitive but not specific as an indicator of left ventricular enlargement. In patients without left ventricular hypertrophy, an apical diameter greater than 3 cm in the left lateral decubitus was sensitive (92%) and specific (91%) for an enlarged left ventricle. The positive and negative predictive values were 86% and 95% respectively. Therefore, the location of the apical impulse in relation to the mid-clavicular line or the mid-sternal line is not a reliable indicator of increased left ventricular end-diastolic volume. However, an apical impulse greater than 3 cm may be an accurate indicator of left ventricular enlargement.