Regulation of in vitro and in vivo T cell activation by CD43

Accessory molecule interactions can be critical in determining the outcome of a T cell's encounter with antigen. Cell adhesion proteins may augment T cell responses by facilitating TCR engagement of the antigen-MHC complex, while co-stimulatory molecules may deliver distinct signals that modulate T cell responsiveness. CD43 (leukosialin, sialophorin) has been suggested to influence cell activation by steric hindrance based upon the large size and glycosylation of the protein, as well as the relative abundance of the protein on the cell surface. In this paper we examine both in vitro and in vivo T cell-dependent responses in CD43-deficient mice. We demonstrate that T cells from CD43-deficient mice are hyper-responsive following both in vivo and in vitro activation, and that this is observed in response to not only TCR-CD3-mediated stimulation, but also following receptor-independent activation. This data suggests that mechanisms other than non-specific steric hindrance are important in the regulation of T cell activation by CD43.      

Comparative Pharmacokinetics and Pharmacodynamics of Two Recombinant Human Interferon Beta la (IFNβ-1a) Products Administered Intramuscularly in Healthy Male and Female Volunteers

Pharmaceutical Research -     

Glomerulonephritis with absent glomerular basement membrane antigens

This is a report of a child with glomerulonephritis and no family history of renal disease. On renal biopsy there was splitting and thinning of glomerular basement membrane antigens. These findings are similar to those seen in patients with familial nephritis and may be part of a spectrum of primary glomerular basement membrane defects.     

Central nervous system lesion causing urethral instability and urinary incontinence

We report on a girl in whom urinary incontinence developed after surgery for a cerebral arteriovenous fistula. Urodynamic evaluation demonstrated periodic decreases in urethral pressure and external anal sphincter electromyographic activity. These episodes were associated with entry of radiographic contrast material into the urethra and urinary incontinence. Treatment with ephedrine sulfate prevented entry of urine into the proximal urethra and resulted in complete daytime continence, despite persisting urodynamic evidence of urethral and electromyographic abnormalities.     

Multifocal adenocarcinoma of the stomach in a child with common variable immunodeficiency

The clinical course of a child who developed an adenocarcinoma of the stomach at 11 years of age is described. At 6 years of age, the child was evaluated for abdominal pain, weight loss, and vomiting. She was found to have hemorrhagic, atrophic gastritis, achlorhydria, and panhypogammaglobulinemia. The gastritis improved with corticosteroid therapy, but relapsed each time that the steroid dosage was tapered. The clinical course was marked by severe growth failure, recurrent infections, and intermittent abdominal pain. Radiographic studies done when the patient was 11 years of age demonstrated a large fungating mass on the lesser curvature of the stomach. Endoscopy and biopsies done 1 year previously had not revealed any sign of malignancy. A radical gastrectomy was performed. Microscopic studies revealed multifocal adenocarcinoma of the stomach with no evidence of invasion of the submucosa or local lymph nodes. The patient died of Candida septicemia and pneumonia 6 months after the gastrectomy. There was no evidence of recurrence of the tumor on autopsy. The relationship between common variable immunodeficiency and gastrointestinal disease is described.     

Immunoelectrophoretic studies of prekallikrein in human plasma

Using a rabbit anti-human prekallikrein antibody crossed immunoelectrophoresis (CIE) and Laurell rocket antigen determinations were done in plasmas of subjects with Fletcher (prekallikrein, PKA), Fitzgerald (high molecular weight kininogen), Hageman (XII), and PTA (XI) deficiencies as well as in patients with activation of coagulation (intravascular coagulation syndromes). Abnormal CIE patterns were seen in the Fletcher and Fitzgerald deficient plasmas and also in some of the patients with intravascular coagulation. $\text{In}$$\text{vitro}$ studies of plasma treated with thrombin, plasmin, and contact activating agents indicated that abnormal CIE patterns and increased PKA antigen levels were indicative of activation of the Hageman factor dependent pathway and not the result of plasma clotting by thrombin. $\text{In}$$\text{vivo}$ activation of the Hageman factor dependent pathway frequently results in an abnormal CIE and a low PKA antigen level.     

Gated MR imaging of left atrial myxomas

Two cases of left atrial myxoma were evaluated with magnetic resonance (MR) imaging. In both cases, the myxoma was clearly defined as to its location, origin, and size. In one case, the myxoma prolapsed through the mitral valve. Our study indicates that MR imaging is valuable in the diagnosis of myxomas.