Immunologic Reactions Against Insulin

Antibodies against insulin in three cases of insulin resistant diabetes mellitus were studied. These were IgG antibodies and their insulin-binding capacity was determined by a double antibody precipitation technique. These anti-insulin antibodies were associated in one case with lymphadenopathy, responsive to corticosteroids; anti-insulin activity was detected in an in vitro lymph node culture. In the other two cases, insulin antibodies were associated with an acute viral disease and intermittent insulin resistance of long duration. Although the insulin-binding activity as determined by the double antibody system was reproducible with individual serum samples, serum insulin-binding activity varied markedly on different days. This was presumptively because of variable degrees of free antibody associated with insulin administration; variable amounts of insulin-anti-insulin complexes were present in these sera. Cross-reactivities of insulins and certain insulin fragments from different species were compared by an inhibition technique and they demonstrated the importance of the secondary and tertiary structures in the antigenic determinants of insulin.

A Solid Phase Radioimmunoassay for the Quantitation of Human Reaginic Antibody against Ragweed Antigen E

IgE antibody directed against antigen E (AgE) of ragweed extract was measured quantitatively in the sera of 15 ragweed sensitive patients before initiation of immunotherapy. The assay employed polystyrene tubes which were successively coated with myeloma IgE and excess rabbit anti-IgE. This matrix which was specific for IgE bound IgE from the patients' serum in a reproducible and measurable manner. Radiolabeled AgE then reacted quantitatively with IgE antibody from the patients' serum which was attached to the solid phase. A double antibody method was developed simultaneously and gave comparable results for sera assayed by both procedures. Total serum IgE and the dose response of histamine release by AgE from washed leukocytes of the patients were also determined.

The concentration of IgE anti-AgE in the 15 sera ranged from 3.2 to 400 ng/ml by polystyrene tube assay. Serum IgE ranged from 82 ng to 6 µg/ml and the percentage of the serum IgE specific for AgE varied from 0.3 to 41. Leukocyte sensitivity measured by the reciprocal of the minimum concentration of AgE resulting in release of 50% of the total histamine encompassed a 300-fold range.

The level of IgE antibody to AgE was not correlated significantly with total serum IgE. Cell sensitivity varied independently of total serum IgE or nonspecific IgE. A highly significant correlation was found between IgE anti-AgE and cell sensitivity. Leukocyte sensitivity was found to be an exponential function of the serum antibody concentration.

The canine respiratory immune response

The canine respiratory secretory immune response was studied by quantitative delivery of keyhole limpet hemocyanin (KLH) to the lower respiratory tract (LRT) and compared with intravenous administration of KLH. Respiratory secretions (RS) were standardized by IgA content and antibody against KLH studied by precipitin, passive hemagglutination and radioimmunoelectrophoretic (RIEP) techniques. Dogs immunized with KLH by either the respiratory or the intravenous route showed precipitating antibodies in serum but not RS. In these studies, aerosolized KLH resulted in IgA, IgG and IgM antibodies in RS and serum, and a comparatively higher antibody titer in RS than occurred following intravenous KLH.

Induced seizures as therapy for experimental stroke in monkeys

✓ Seizures were induced in 12 monkeys rendered hemiparetic by middle cerebral artery occlusion. In a control group of five hemiparetic monkeys seizures were not induced. A mass spectrometer was used to monitor regional oxygen tension (pO2), carbon dioxide tension (pCO2) and the partial pressure of argon (pA) within the ischemic brains. Seisure activity resulted in a 74.3% mean increase in pO2 and 16.9% mean decrease in pCO2. The mean argon washout time was decreased 29.1%. The changes were transient and recovery from hemiparesis was no better in the experimental group than in the control group.

Direct mass spectrographic measurement of regional intracerebral oxygen, carbon dioxide, and argon

✓ During 10 operative procedures on eight patients with various intracranial lesions a membrane mass spectrometer was used to measure the regional partial pressure of oxygen (pO2), carbon dioxide (pCO2), and argon (pA) in subcortical white matter. The pO2 varied from 12 to 49 mm Hg, and the pCO2 from 31 to 123 mm Hg. Lowering intracranial pressure to 0 by ventricular drainage increased the pO2 and argon washout values (except in necrotic brain where no increase occurred) and decreased the pCO2 values. In one patient restoration of intraventricular pressure to the initial level of 220 mm H2O resulted in a 20% decrease in pCO2, a 15% decrease in argon washout rate, and a 21% increase in pCO2. These data suggest that regional cerebral blood flow, pO2, and pCO2 are influenced by intracranial hypotension as well as the condition of local brain tissue.

Treatment of multiple intracerebral cryptococcal granulomas with 5-fluorocytosine. Case report

✓ The use of 5-fluorocytosine in the treatment of three intracerebral suppurative cryptococcal granulomas in one patient is described. Except for a transient rise in the serum glutamic pyruvic transaminase the drug was well tolerated during the 10 weeks it was administered. One year following treatment the patient was well and apparently free of cryptococcal infection.

Reverse passive respiratory reactions due to anti-IgE in rhesus monkeys

Two groups of Rhesus monkeys were previously established. One group included animals with immediate-type responses to respiratory challenge with ascaris antigen. The second group included animals with no respiratory reactivity to aerosol challenge with the same antigen. Both groups of Rhesus monkeys were subjected to controlled respiratory challenge with rabbit anti-human IgE. This anti-human IgE had sufficient cross reactivity with rhesus IgE to produce both the expected reverse passive cutaneous reactions and an acute respiratory response to aerosol challenge in five of six monkeys. The respiratory response to anti-IgE has been termed the reverse passive respiratory reaction. The characteristics of respiratory responses in animals reacting to anti-IgE were compared with those resulting from ascaris antigen challenge. The reverse passive respiratory reactions meet the criteria which have been established for the other acute previously described IgE mediated respiratory responses in Rhesus monkeys.

Precipitation reactions of an IgA myeloma protein with nitrophenylated proteins

The reactions of a human serum with an IgA monoclonal component which precipitates with dinitrophenyl (DNP) conjugated proteins are described. The IgA existed in polymeric and monomeric forms. Only the polymeric forms precipitated DNP-proteins, but binding of DNP proteins by the monomer was demonstrated by autoradiographic immunoelectrophoresis. The precipitating reactions of the IgA occurred with certain populations of DNP-proteins and were higher with more heavily haptenized preparations. The binding affinity of the strongly precipitating IgA serum for DNP-lysine was low and the precipitation reaction with DNP-proteins was not inhibited by DNP-lysine. The results indicated that precipitation involves the reaction of polymeric forms of IgA with DNP-protein configurations or closely associated DNP-DNP configurations in heavily haptenized conjugates.