Response of human B cells to different anti-immunoglobulin isotypes: absence of a correlation between early activation events and cell proliferation.

Cross-linking of surface immunoglobulin (sIg) by antibodies against IgM, IgG and IgD activates B cells and in some circumstances can induce cell proliferation. We studied the potential link between anti-Ig-induced changes in the cytosolic free Ca2+ concentration ([Ca2+]i), inositol phosphate production and the ability to induce cell proliferation in the presence or absence of the phorbol ester 12-O-tetradecanoylphorbol 13-acetate (TPA). Anti-IgM, but not anti-IgD or anti-IgG, induced cell proliferation in the presence but not the absence of TPA.

Corticosteroids-salicylate interaction in a case of juvenile rheumatoid arthritis.

In an 11-year-old child with juvenile rheumatoid arthritis (JRA), the addition of prednisone caused a significant decrease in salicylate serum concentrations. A pharmacokinetic assessment suggested that these changes were not the result of altered compliance or impaired absorption of salicylate but rather an increase in salicylate clearance induced by the corticosteroid.

High-dose versus low-dose intravenous immunoglobulin in hypogammaglobulinaemia and chronic lung disease.

In a randomised cross-over study 12 patients with antibody deficiency and chronic lung disease received monthly infusions of either 0.6 g/kg or 0.2 g/kg intravenous immunoglobulin for six months, and were then switched to the alternative dose for a further six months.

Induction of human B cell proliferation and differentiation by the combination of phorbol ester and ionomycin.

Phorbol esters and Ca2+ ionophores are known to mimic intracellular messengers involved in cell activation. We studied the effects of 12-O-tetradecanoylphorbol 13-acetate (TPA) and ionomycin on tonsil and peripheral blood-derived B lymphocytes. We show that TPA and ionomycin are co-mitogenic and induce B lymphocyte differentiation.

The regulatory role of interleukin 2-responsive T lymphocytes on human marrow granulopoiesis.

The effect of recombinant interleukin 2 (IL2) on marrow CFU-C colony formation was evaluated to define the role for T lymphocytes in human marrow granulopoiesis. The colony-stimulating factor (CSA) used in our experiments was found to contain IL2. IL2 depletion from CSA resulted in a reduction in CFU-C colony proliferation.

Mitogenic response of human thymocytes: identification of functional Ca2+-dependent and independent signals.

In contrast to peripheral blood mononuclear cells (PBMC), human thymocytes do not exhibit a proliferative response to the T cell mitogens phytohaemagglutinin (PHA), concanavalin A (Con A), or Staphylococcal protein A (SPA). In thymocytes and PBMC, Con A and PHA induce increases in free cytosolic calcium concentrations [( Ca2+]i). Since both Con A and PHA induce similar increases in [Ca2+]i in thymocytes and PBMC, the absence of thymocyte proliferation was not due to an inability to induce an increase in [Ca2+]i.

Corticosteroids for prevention of adverse reactions to intravenous immune serum globulin infusions in hypogammaglobulinemic patients.

Severe adverse reactions to intravenous immune serum globulin occurred repeatedly in four of 10 hypogammaglobulinemic patients. Treatment-limiting symptoms included fever, chills, headache, hypertension, and chest pain. Pretreatment of patients with hydrocortisone immediately prior to infusion prevented subsequent adverse reactions and permitted these patients to receive immune serum globulin intravenously.

The regulatory role of interleukin 2-responsive T lymphocytes on early and mature erythroid progenitor proliferation.

To analyze the role of T lymphocytes in human erythropoiesis, we evaluated the effect of recombinant interleukin 2 (IL 2) on marrow CFU-E and BFU-E colony formation in vitro. IL 2 resulted in an increase in CFU-E and BFU-E colony numbers in a dose-dependent manner. This increase could be prevented by anti-Tac, a monoclonal antibody to the IL 2 receptor.

Increased susceptibility to Mycoplasma infection in patients with hypogammaglobulinemia.

The incidence and morbidity of Mycoplasma infections were examined in a group of 23 patients with hypogammaglobulinemia. Among this group of patients, 18 had one or more episodes of acute respiratory illness during which Ureaplasma urealyticum, Mycoplasma orale, or Mycoplasma pneumoniae were isolated from sputum. Resolution only followed institution of specific antibiotic therapy and elimination of the Mycoplasma.

Functional comparison of recombinant interleukin 2 (IL-2) with IL-2-containing preparations derived from cultured cells.

Due to its purity and potential availability in large amounts, human recombinant interleukin 2 (IL-2) expressed in Escherichia coli is an important source of IL-2 for experimentation and possible therapy. To date, very few comparisons between the activity of recombinant IL-2 and conventional cell-derived preparations of IL-2 have been made. This is particularly important since the use of recombinant IL-2 may have some specific limitations.

Benefit of intravenous IgG replacement in hypogammaglobulinemic patients with chronic sinopulmonary disease.

Seven patients with hypogammaglobulinemia and chronic sinopulmonary infections were treated with a preparation of intravenous gammaglobulin. In order to maintain levels of serum IgG at greater than 500 to 750 mg/dl four weeks after infusion, 0.6 g/kg was administered every month.

Heterogeneity of the immunological deficiency in ataxia-telangiectasia: absence of a clinical-pathological correlation.

We have been impressed by the absence of severe and recurring infections in most of our patients with ataxia-telangiectasia. In this report, our clinical and laboratory data on 25 patients are reviewed. We found a heterogeneity of immunological results and a lack of correlation between these results and clinical well-being.

Sinus node dysfunction in a healthy pediatric population.

ECG recordings of 624 healthy children (age range 6 to 12 years) from a rural population were analyzed for evidence of sinus node dysfunction. Twelve children were found to have the disorder and they underwent further assessment in order to establish any etiological factors or anatomical abnormalities. All the children were asymptomatic and physical examination was completely normal.