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Biomedical subjects

F Milgrom

Publications and source records attributed to F Milgrom.

At least 37 records · Page 2Linked to original sources

Detection of antigens from gram-negative bacilli in urine of children with urinary tract infections. I. Common antigen of Enterobacteriaceae.

Enterobacterial common antigen (ECA) has attracted considerable interest since the original publication by Kunin in 1962. In the present study we demonstrated this antigen directly in the urine from patients with urinary tract infections (UTI) elicited by enterobacteria. Sheep erythrocytes were incubated with UTI urine; this resulted in their coating with ECA, which was studied by means of hemagglutination by anti-ECA serum. Test tube hemagglutination and the more simple slide hemagglutination were employed and with both procedures similar results were obtained. Positive results were observed in 94-99% of urine specimens from enterobacterial UTI collected in The Buffalo Children's Hospital in the 1960s. ECA in urine could also be demonstrated by hemagglutination inhibition. In this test, antibodies in anti-ECA serum were neutralized as a result of incubation of this serum with urine, and agglutination by the antiserum of sheep erythrocytes coated with a standard ECA preparation was prevented or reduced. By means of this latter test, ECA could be demonstrated in 67-88% of urine specimens from enterobacterial UTI. The possible diagnostic application of these tests has been discussed.

Antigens, Bacterial↗

Detection of antigens from gram-negative bacilli in urine of children with urinary tract infections. II. Thermostable bacterial proteins.

An enzyme immunoassay for detection of bacterial antigens in urine specimens from urinary tract infections (UTI) was developed. The antigens detected in infections by Enterobacteriaceae: Escherichia coli, Enterobacter aerogenes, and Proteus sp. were different from the enterobacterial common antigen (ECA). They were digested by trypsin and were characterized by remarkable thermostability; their molecular weights were approximately 34,000 and 31,000. They were detected by means of antisera to ECA or to suspension of E. coli. The frequency of positive results with urine specimens from enterobacterial UTI was 87-99%. In contrast, the urine specimens of UTI by Pseudomonas aeruginosa were positive in fewer than 20% with anti-E. coli sera, but were positive in more than 85% in tests with antiserum to P. aeruginosa. The possible diagnostic application of the described tests was discussed.

Antigens, Bacterial↗

Unusual precipitins in pathological human sera.

In conducting double diffusion gel precipitation tests, unexpected, strong precipitation reactions were noticed between a serum originating from a renal graft recipient and many pathological human sera. The highest frequency of positive reactions were produced by sera of patients with infectious mononucleosis (83%), chronic Epstein-Barr virus infections (72%), rheumatoid arthritis (57%), lepromatous leprosy (57%), and AIDS (44%). The precipitin in these pathological sera was identified as an antibody of IgM variety and the precipitinogen in the transplantation serum was shown to be a thermostable component with beta-globulin mobility. No explanation of the nature of reactions observed can be given at present.

Acquired Immunodeficiency Syndrome↗

IgG rheumatoid factor in human and rabbit transplantation sera.

Sera of human recipients of kidney allografts and rabbit recipients of skin allografts were tested by means of enzyme immunoassays (EIA) for IgG rheumatoid factor (RF) combining with human IgG (RF-H) or rabbit IgG (RF-R). In humans, the mean OD value in EIA for RF-H was significantly higher in 185 sera of allograft recipients than in 46 pretransplantation sera and 100 sera of normal subjects. Furthermore, the mean OD in patients who rejected their grafts was higher than in patients with satisfactory graft function. Interestingly, there was no difference in OD values for RF-R between sera of graft recipients and sera of normal subjects. Of 52 rabbit recipients of skin allografts, 24 were positive for both RF-R and RF-H, 4 were positive only for RF-R, another 4 only for RF-H, and 20 were negative for both. Renal allografts originating from the previous donors of skin grafts resulted, in most instances, in a significant decrease in the strength of the reaction for both RF-R and RF-H. The possible role of graft rejection in stimulation of RF formation as well as the possible role of RF in graft rejection should be considered.

Animals↗

Multispecificity of monoclonal rheumatoid factor.

The study involved a monoclonal rheumatoid factor referred to as RF-AN, obtained by Steinitz and his associates from IgG-reactive human lymphocytes 'immortalized' by infection with Epstein-Barr virus. RF-AN combined with red blood cells (RBC) sensitized by either human or rabbit IgG antibodies. The monoclonal character of RF-AN strongly suggested that the same molecule of this factor combined with IgG of both species. Additional evidence for this contention was obtained from absorption and mixed agglutination experiments. RBC sensitized by either human or rabbit antibodies would remove serological activity of RF-AN for both human and rabbit IgG. RF-AN produced exclusively mixed agglutinates when reacted with a mixture of human RBC sensitized by human antibodies and chicken RBC sensitized by rabbit antibodies. Furthermore, it was shown that inhibition with aggregated human Fraction II gave strictly 'specific' results in that it abolished the reaction of RF-AN with RBC sensitized by human antibodies, but not by rabbit antibodies. This result was interpreted as indicating that RF-AN has a multispecific character, i.e., has separate combining sites for human and rabbit IgG. Interestingly, specific inhibition could not be achieved with aggregated rabbit Fraction II and this preparation affected reactivity of RF-AN with RBC sensitized by human antibodies as well as by rabbit antibodies.

Animals↗

Serological relationship between rat and human carcinoembryonic antigen.

Enzyme immunoassays showed that a rabbit antiserum to rat carcinoembryonic antigen (CEA) had high activity with extracts containing human CEA, which was almost completely inhibited by extracts containing human or rat CEA. Little or no inhibition was obtained with extracts of normal human or rat tissues or by human blood group A or B substances. A monkey antiserum to human CEA had strong activity against extracts containing rat CEA, and little or no activity against extracts of normal rat liver or kidney or a CEA-negative rat colon tumor. Activity of the monkey antiserum against rat CEA was almost completely inhibited by extracts containing rat or human CEA. Little or no inhibition was obtained with extracts of normal rat or human tissues. These results suggest that human and rat CEA share antigenic determinants and that they may be analogous moieties.

Animals↗

Development of rheumatoid factor research through 50 years.

The discovery of Waaler in 1937 initiated fruitful research on RFs. It was not until the early 1960s that investigators in the field agreed that RFs are antibodies to Fc fragment of IgG. Separate factors combining with human and rabbit IgG and a factor combining with both these IgGs were at first demonstrated by mixed agglutination and then by separation through IgG-conjugated columns. Only RF combining with native autologous IgG should be considered an autoantibody. Other RFs are allo- or heteroantibodies. Cross-reacting RFs that combine with IgG of various species or with IgG and antigens of cell nuclei are of considerable interest. This cross-reactivity may be due to a combining site interacting with shared epitopes or otherwise to multispecificity of the RF molecule in that it has separate or partially overlapping combining sites acting on different epitopes. Experimental studies conducted since the mid-1950s showed that formation of RFs may be elicited by altered autologous IgG. Under natural conditions such alteration was shown to result from interaction of IgG antibody with its corresponding antigen and RF in many infectious diseases and possibly also in rheumatoid arthritis appeared to result from stimulation by immune complexes. More recently alterations of IgG by its reaction with microbial Fc receptors as well as non-specific polyclonal stimulation of B cells were shown to play a role in RF formation. RFs have been implemented in the pathogenicity of rheumatoid arthritis. Recent studies on dispersion of immune complexes in tissue sections by aggregated IgG showed that self-polymerization of IgG RFs results in formation of glomerular deposits in various nephropathies.

Antibodies, Anti-Idiotypic↗

Induction in human allograft recipients of unresponsiveness to anti-lymphocyte globulin.

The observations presented here confirm previous reports that polyclonal ALG prepared at the University of Minnesota or ATGAM of The Upjohn Co., administered as described, rarely induced sensitization of patients to the horse gamma globulin. In addition, the phenomena of transient antibody production prior to the onset of unresponsiveness and the induction of unresponsiveness in individuals with preexisting antibodies were observed.

Animals↗

A nonimmunoglobulin precipitin to tissue extracts in pathological human sera.

An alpha-globulin component was noted in pathological human sera, which produced gel precipitation reactions with extracts of human and animal liver. The highest incidence of the precipitin was found in malaria (95%), renal graft rejection (81%), and rheumatoid arthritis (57%). The precipitinogen was thermostable and ethanol soluble; of two precipitation lines formed by this component, one merged into identity reaction with a line produced by commercial lecithin of bovine origin. The possible diagnostic application of the reactions noted was considered.

Alpha-Globulins↗

Release of platelet-activating factor from rabbit heart perfused in vitro by sera with transplantation alloantibodies.

During "hyperacute rejection" of rabbit heart perfused with transplantation alloantibodies, platelet activating factor (PAF) was released into the coronary effluent, which appeared to have physicochemical and functional properties similar to the 1-octadecyl-2-acetyl-sn-glyceryl-3-phosphorylcholine (synthetic PAF) and to PAF obtained from IgE-sensitized rabbit basophils. The release of PAF was associated with an early tachycardia, followed by increasing bradycardia and conduction arrhythmias, as well as decrease of coronary flow and of amplitude of electrogram. The heart stopped beating within 30 min. The release of PAF as well as the "rejection" required the presence of fresh rabbit serum as a source of complement. The PAF receptor antagonist SRI 63-072 in a dose of 0.6 mg, reversed by 70% the reduction of coronary flow within 2-4 min after its addition to the perfusate; ED50 was 0.4 mg. Bradycardia and arrhythmia were reduced; however, the normal electrical activity was only occasionally restored. The cessation of heart action was delayed up to 50 min after the beginning of perfusion with transplantation alloantibodies and complement, but it was not prevented. These results suggest that PAF is released during "rejection" of the heart perfused in vitro with serum containing transplantation alloantibodies in the absence of inflammatory cells and that this mediator is at least in part responsible for the deterioration of cardiac function.

Animals↗

Thermostable ethanol-insoluble antigens of human heart muscle.

Organ-specific reactions were observed between thermostable ethanol-insoluble (BE) fraction of human heart muscle and its corresponding rabbit antiserum by means of tanned cell hemagglutination test, enzyme immunoassay, and gel precipitation test. Two heart-specific components could be identified using gel precipitation and immunoblotting procedures. Antibodies to human heart muscle BE combined also with heart BE preparations from mammals other than man; these interspecies cross-reactions included also rabbit heart BE pointing to the 'auto' nature of some of the antibodies under investigation. The heart antigens under study were distinct from the organ-specific antigen demonstrated by Espinosa and Kaplan in acid extract of human heart muscle.

Agglutination Tests↗

Reactions of monoclonal antibodies to human MN blood groups with red blood cells of subhuman primates.

All 12 samples of chimpanzee erythrocytes tested were agglutinated by the commercial polyclonal anti-M reagent of rabbit origin, but none was agglutinated by monoclonal anti-M reagent of murine origin. This, as well as results of absorption experiments, showed that the polyclonal and monoclonal anti-M reagents detect different M epitopes. Polyclonal anti-N reagent of rabbit origin and monoclonal reagent of murine origin obtained by immunization with N blood group substance did not react with any chimpanzee erythrocyte samples. On the other hand, monoclonal anti-N reagent originating from immunization with M blood group substance agglutinated two of the 12 tested chimpanzee erythrocyte samples. This and other experimental results strongly suggested that the latter monoclonal anti-N reagent combined with "N" antigen, i.e., an antigen present on glycophorin B of human M as well as N erythrocytes; apparently erythrocytes of some chimpanzees contain also this antigen.

Animals↗

Antibodies to saline extractable tissue antigen in sera of patients with renal diseases.

Multiple serum samples originating from 110 renal allograft recipients were examined against saline extract of normal human kidney by means of double diffusion gel precipitation. Eleven recipients were found to be positive; 99 of 106 sera from these patients were positive. Pretransplantation sera were available from 7 of these recipients and 6 patients were found "positive." The precipitation reaction was composed of one line. Identity reactions were formed between the lines produced by sera from all patients except 1. Sera of patients from end-stage renal disease produced similar reaction; however, only 3 of 234 sera from patients with nonrenal diseases precipitated the kidney extract. None of 154 normal sera were positive. Several positive sera also were positive in complement fixation tests with human kidney extract. Evidence was presented that the antibodies under study combined with a nonorgan-specific but species-restricted tissue antigen. The hypothesis was advanced that these antibodies are autoantibodies formed in response to a sequestered antigen released as a result of tissue damage. Apparently, the antigen is released frequently in immunogenic form from injury to kidney but infrequently from injury to other organs.

Autoantibodies↗

Reactions of murine monoclonal antibodies to blood group MN antigens.

BALB/c mice were immunized by intraperitoneal injections with human blood group substances; 4 mice with M and 4 with N. Immune spleen cells were fused with murine myeloma cells X63-Ag-8.653. Two clones secreting monoclonal anti-M and seven secreting monoclonal anti-N were identified. All antibodies were of IgG1 subclass and had kappa light chains. Three clones have been maintained that produced antibodies useful for typing purposes: anti-M, A09 originating from a mouse injected with M, anti-N, AH7 originating from a mouse injected with N, and anti-N BO10 originated from a mouse injected with M substance. In typing 370 erythrocyte samples, monoclonal reagents gave identical results with commercial anti-M or anti-N typing sera of rabbit origin. Significantly, anti-N reagent AH7 obtained by immunization with N substance showed serological differences from anti-N reagent BO10 obtained by immunization with M substance in that AH7 had apparently higher avidity to N specificity on glycophorin A of N erythrocytes than BO10, whereas BO10 showed higher avidity for 'N' specificity on glycophorin B of M and N erythrocytes than AH7. These two reagents showed also somewhat different patterns of reaction with enzymatically digested erythrocytes. This apparent serologic difference between N and 'N' specificities is at variance with current immunochemical data.

Animals↗

Tumor immunity in rats immunized with rat carcinoembryonic antigen.

Active immunization of rats with an emulsion consisting of Freund's complete adjuvant (FCA) and an extract of rat tumor containing carcinoembryonic antigen (CEA) induced clear-cut protection from growth of the syngeneic CEA-positive tumor, RCA-1. No protection was observed in rats treated with FCA alone nor was there protection against a tumor that no serologically detectable CEA. The results suggested that the tumor immunity exhibited by the immunized rats was mediated by an immune response specific for rat CEA. It was shown further that multiparous rats were more resistant to growth of RCA-1 tumor than nulliparous rats. This suggested that immunization against rat CEA, which is an oncofetal antigen, may occur during pregnancy.

Adenocarcinoma↗

Are cross-reacting natural antibodies multispecific?

Human natural antibodies to antigens of Escherichia coli and Serratia marcescens were studied for cross-reactivity. The organisms were grown on synthetic media and extracted at 100 degrees C. The extracts were precipitated three times at 71% ethanol concentration and redissolved at the desired concentration. These preparations were referred to as Escherichia antigen (Ea) and Serratia antigen (Sa). They readily coated red blood cells (RBC), which then could be used for passive agglutination tests. Human serum selected for this study had strong agglutinins combining with both antigens (cross-reacting antibody) and rather weak agglutinins combining with Ea only or Sa only, a property that became obvious from absorption experiments. Absorption of the serum with RBC coated by Ea removed all activity for Ea and most of the activity for Sa, and the opposite effect was noted after absorption of the serum by RBC coated by Sa. The activity against both antigens could be recovered by elution of antibodies at 56 degrees C from RBC coated by either Ea or Sa. Significantly, inhibition of the serum or the eluate with soluble antigens gave strictly specific results in that Ea abolished only the reaction with RBC coated by Ea and did not influence the reaction of RBC coated by Sa, and the opposite result was obtained upon inhibition of the serum with Sa. These results strongly indicated to us that the cross-reacting antibodies under study were multispecific, i.e., had different antigen-reactive sites (haptophore groups) for Ea and Sa. Further evidence supporting this contention was obtained from a study in which the cross-reacting antibody was 'labelled' by a bacterial antigen. To this end, the tested serum was neutralized with Sa and then reacted with RBC coated by Ea. From these RBC, antibodies were eluted from which Sa was recovered. A 'mirror image' experiment was also conducted in which Ea was recovered from antibodies that were blocked by Ea and reacted with RBC coated by Sa.

Antibodies, Bacterial↗