Development of unique antibodies directed against each of the six different phosphotyrosine residues within the T cell receptor CD3ζ chain

Signal transduction from the T cell antigen receptor (TCR)/CD3 complex involves six different immunoreceptor tyrosine-based activation motifs (ITAM) located within the cytoplasmic tails of the CD3 chains. Each ITAM possesses two conserved tyrosine residues that can undergo phosphorylation upon TCR/CD3 crosslinking and become a docking site for SH2-containing effector molecules. Specificity of the SH2 domains is determined by their ability to bind a phosphorylated tyrosine in the context of a longer peptide motif within the target protein. As a result, phosphorylation of different tyrosines within the CD3 cytoplasmic tails creates docking sites for distinct SH2-containing signaling proteins that differentially impact on the quality of the T cell response. In the present study, we prepared antibodies specific for each of the six different phosphotyrosines of the mouse CD3ζ chain. The antibodies were characterized with respect to their cross-reactivity, ability to recognize the phosphorylated versus non-phosphorylated forms of tyrosine-containing motifs, and cross-reactivity with the homologous phospho-motifs on the human CD3ζ protein. The antibodies were found to be specific and selective for phospho-CD3ζ. They can serve as useful tools for distinguishing between the six potential tyrosine phosphorylation sites on the CD3ζ chain, and for correlating the phosphorylation of specific CD3ζ tyrosine residues with activation of signaling pathways that dictate T cell differentiation into responding, anergic, or apoptotic cells.     

HIV Care and Treatment Beliefs among Patients Initiating Antiretroviral Treatment (ART) in Oromia,Ethiopia

To better understand patient beliefs, which may influence adherence to HIV care and treatment, we examined three dimensions of beliefs among Ethiopian adults (n = 1177) initiating antiretroviral therapy (ART). Beliefs about benefits of ART/HIV clinical care were largely accurate, but few patients believed in the ability of ART to prevent sexual transmission and many thought Holy Water could cure HIV. Factors associated with lower odds of accurate beliefs included advanced HIV, lack of formal education, and Muslim religion (benefits of ART/clinical care); secondary or university education and more clinic visits (ART to prevent sexual transmission); and pregnancy and Orthodox Christian religion (Holy Water). Assessment of patient beliefs may help providers identify areas needing reinforcement. In this setting, counselors also need to stress the benefits of ART as prevention and that Holy Water should not be used to the exclusion of HIV care and ART.     

Cutaneous manifestations of pituitary gland diseases

The pituitary gland is also known as the "master" gland of the endocrine system, because it controls the functions of the other endocrine glands. From its lofty position in the sella turcica it sends signals to the thyroid gland, adrenal glands, ovaries and testes. It modulates the production of a variety of hormones that have dramatic effect on metabolism, blood pressure, sexuality, reproduction, growth, milk production and other vital body functions and therefore are essential for homeostasis. Since changes of the internal environment often mirrors in the skin, this article will focus on the skin changes in pituitary gland diseases. Disorders resulting from excessive secretion of hormones as well as from hormones deficiency of this complex endocrine organ will be reviewed.     

Effect of erythropoietin therapy on red cells filterability and left ventricular mass in predialysis patients

BACKGROUND: Cardiovascular complications are the leading cause of mortality in patients with end-stage renal disease. Left ventricular hypertrophy (LVH) is recognized as an independent risk factor for cardiovascular morbidity and mortality. At the onset of dialysis, more than 70% of the patients with chronic kidney disease have echocardiographic evidence of LVH. Anemia, increased red cells filterability time (RCFT), and blood viscosity are known to induce LVH. AIM: To evaluate, prospectively, the effects of erythropoietin (EPO) therapy for 20 weeks on RCFT and left ventricular mass (LVM). PATIENTS AND METHODS: Twenty uremic and anemic predialysis patients with creatinine clearance test below 35 mL/min were studied. RCFT test and three-dimensional echocardiography were performed at 0, 10, and 20 weeks. RESULTS: EPO therapy for 20 weeks did not adversely affect renal function and did not significantly change the mean blood pressure. It significantly increased the hemoglobin and fibrinogen levels, and decreased RCFT and LVM (p < .01). CONCLUSION: Although correction of anemia can contribute to regression of LVM, we speculate that an increasing number of cells with normalized viscoelastic properties and a direct effect of EPO on erythrocytes and myocardiocytes, through specific receptors, may also play an important role.     

The role of heparanase in lymph node metastatic dissemination: dynamic contrast-enhanced MRI of Eb lymphoma in mice

Heparanase expression has been linked to increased tumor invasion, metastasis, and angiogenesis and with poor prognosis. The aim of the study was to monitor the effect of heparanase expression on lymph node metastasis, in heparanase-overexpressing subcutaneous Eb mouse T-lymphoma tumors, and their draining lymph node. Dynamic contrast-enhanced magnetic resonance imaging (MRI) using biotin-BSA-GdDTPA-FAM/ROX was applied for analysis of blood volume, vascular permeability, and interstitial convection, and for detection of very early stages of such metastatic dissemination. Eb tumors increased extravasation, interstitial convection, and lymphatic drain of the contrast material. Interstitial flow directions were mapped by showing radial outflow interrupted in some tumors by directional flow toward the popliteal lymph node. Heparanase expression significantly increased contrast enhancement of the popliteal lymph node but not of the primary tumor. Changes in MR contrast enhancement preceded the formation of pathologically detectable metastases, and were detectable when only a few enhanced green fluorescent protein (EGFP)-expressing Eb cells were found near and within the nodes. These results demonstrate very early, heparanase-dependent vascular changes in lymph nodes that were visible by MRI following administration of biotin-BSA-GdDTPA-FAM/ROX, and can be used for studying the initial stages of lymph node infiltration.