Fate of antibodies bound to lymphocyte surface. I.--Study with complement-dependent cytotoxicity, indirect immunofluorescence and radiolabelled antibodies

Anti-HL-A alloantiserum, heterologous antilymphocyte globulins and anti-beta2m antisera were allowed to react to human lymphocytes in vitro. The fate of the antigen-antibody complexes formed at the cell surface has been studied by means of the lymphocytoxicity test in the presence of rabbit complement, radiolabelled antibodies and the indirect immunofluorescence technique. Those techniques demonstrated that initially bound antibodies disappear from the cell surface. This disappearance requires optimal conditions; it does not result from a mere dissociation of antibodies but likely represents partial degradation, internalization and release of antigen-antibody complexes into the extracellular medium. This phenomenon can be regarded as a reflection of the dynamic state of the cell membrane, although it differs from the redistribution of antigen-antibody complexes on the lymphocyte surface (patching and capping). Possible implications of such events are discussed in relation to triggering or blocking of lymphocyte proliferation.

Fate of antibodies bound to lymphocyte surface. II.--Degradation and release of immune complexes

The fate of horse anti-human lymphocyte globulins, rabbit anti-human beta2 microglobulin antibodies and anti-HL-A alloantibodies radiolabelled with 125I and complexed to their corresponding lymphocyte surface antigens, was investigated. During prolonged incubation at 37 degrees C, part of these antibodies were actively released into the surrounding medium after enzymatic degradation occuring either intracellularly or at the cell surface. Metabolism of the antibodies was temperature-dependent and involved only antibodies able to react with antigens on the cell surface. Sephadex G200 filtration of the small percentage of non dialysable radioactive products in the supernatant revealed that all the 125I-anti-human lymphocyte globulin was recovered as a macromolecular structure in the void volume. Similar experiments were performed with 51Cr labelled lymphocytes coated with anti-lymphocyte globulins: treatment with anti-horse immunoglobulin precipitated part of 51Cr activity in the void volume which was therefore associated with anti-human lymphocyte globulin as an immune complex. The same protocol applied to the other two antibodies studied showed that anti-beta2 microglobulin antibodies were recovered both as macromolecular and 7 S immune complexes, whereas anti-HL-A antibodies were recovered as macromolecular, 7 S and still smaller immune complexes.

[Sudden death from ventricular fibrillation after voluntary inhalation of chlorothene in a mechanics apprentice]

In a 20-year-old apprentice mechanic who had deliberately inhaled chlorothene (1,1,1-trichloroethane) an episode of vomiting was followed by ventricular fibrillation with fatal outcome despite intensive care in hospital. Autopsy revealed no anatomical cause of death. This is the first case reported in Switzerland of "sudden sniffing death syndrome".

Insulin antagonism of cortisol action on lechithin synthesis by cultured fetal lung cells

In monolayer cel cultures from late gestation (28-day) rabbit fetal lungs, cortisol (5.5 X 10(-6)M) enhances lecithin synthesis and reduced cellular growth. The addition of insulin (25-100 muU/ml) abolishes the stimulatory effect of cortisol on lecithin synthesis but does not affect its growth-inhibiting activity.

Pharmacologic regulation of alveolar surfactant in fetal and newborn rabbits: ACTH, heroin, isoxsuprine, and glucocorticoid

The evidence that pharmacologic doses of glucocorticoids induce lung maturation and diminish risk of respiratory distress syndrome has been reviewed briefly. Studies with heroin corroborate that pharmacologic induction of lung maturation is possible in the human fetus. Endogenous fetal glucocorticoids may serve as a physiologic mechanism that prepares the immature lungs for birth. Catecholamines may induce release of stored surfactant from type 2 cells into alveolar spaces.

Antiviral effect of interferon covalently bound to sepharose

Interferon, covalently bound to Sepharose 4B activated by cyanogen bromide, induces the antiviral state in sensitive cells. The antiviral effect is neutralized by antiserum specific to interferon and is recovered thereafter when the antibody is detached from the interferon by treatment at low pH. Binding interferon to Sepharose increases the stability of the molecule. It is likely that the interferon molecule acts on the cell receptor without being detached from the beads. However, the data do not exclude the possibility of a small loss of interferon, or fragments of it, after contact with the cell.

Acute renal failure associated with combined gentamicin and cephalothin therapy

Three patients with normal renal function developed acute renal failure between the ninth and twenty-seventh days of combined gentamicin and cephalothin therapy. The dose of gentamicin (4-6 mg/kg/day) was in the normal range, but that of cephalothin (180 mg/kg/day) was abnormally high. The nephropathy was of the tubular-interstitial type and the clinical picture similar to that seen in acute drug-induced nephropathies. Frusemide was given only after the onset of renal failure. In these three patients the high intravenous doses of cephalothin combined with gentamicin were probably nephrotoxic.

Polyadenylic acid in Visna virus RNA

Visna virus 70S RNA contains long stretches of polyadenylic acid [poly(A)]. The homogeneity in length of poly(4) regions is observed in 70S RNA from visna virus and all RNA tumor viruses tested, and not with other types of RNA. By this criterion visna virus resembles RNA tumor viruses.

Effect of intravenous infusion of acetylsalicyclic acid on renal function

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