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Biomedical subjects

J P Vaerman

Publications and source records attributed to J P Vaerman.

At least 163 records · Page 9Linked to original sources

In vitro immunosuppressive effect of serum from orally immunized mice.

Mice were orally immunized by 4 daily intragastric (IG) intubations of 4 X 10(9) SHEEP RED BLOOD CELLS (SRBC). The serum of such mice (OS), taken two weeks after the first intubation, was compared to normal mouse serum for its suppressive effect on in vitro primary responses of normal spleen cells to SRBC. OS regularly depressed the in vitro response to less than 10% of the normal response. The suppressive effect was dose-dependent, antigen-specific and removable by absorption with SRBC. When cultures were stimulated with SRBC pre-exposed to OS, the response was also depressed. The suppression was less when the addition of OS was delayed. OS from BALB/c mice efficiently depressed in vitro responses of spleen cells from other strains. Spleen cells, taken 2 weeks after IG immunization, responded normally to in vitro challenge with SRBC. The suppressive factor had the molecular size of an IgG and could be removed by anti-Ig and anti-IgG1 but not by anti-alpha or anti-mu immunosorbents. Purified IgG1 was more suppressive than IgG2a and IgG2b despite a similar anti-SRBC antibody content.

Absorption↗

Particle counting immunoassay. IV. The use of F(ab')2 fragments and N epsilon-chloroacetyl lysine N-carboxyanhydride for their coupling to polystyrene latex particles.

Improved performance with the latex agglutination immunoassay, PACIA, is possible when the F(ab')2 fragments of antibody are chemically coupled at their hinge region to a protein-coated latex using a new coupling reagent, N epsilon-chloroacetyl lysine N-carboxyanhydride. This reagent, whether by orientating the complete antibody molecule or its F(ab')2 fragment or by preventing antibody denaturation, increased the sensitivity of the PACIA method. The use of F(ab')2 fragments eliminated most serum interference with the test.

Agglutination↗

Interactions between mouse immunoglobulins and staphylococcal protein A.

When mouse serum or ascites is applied on protein A-Sepharose columns and washed with enough phosphate-buffered saline, a second protein peak is often eluted with the same buffer after the first major peak of unbound proteins. This second peak is almost pure Ig G1. More IgG1 plus IgG2a, IgG2b and IgG3 are thereafter eluted with acid saline. 90% of the IgG1 whichhad been eluted with neutral buffer could be re-eluted at the same retarded position with the same buffer. When a gradient from 0 to 3 M sodium thiocyanate was started after the major peak of unbound proteins, all IgG1 was eluted before IgG2 and IgG3. These results suggest that IgG1 has a much lower affinity for protein A than IgG2 or IgG3 and that normal mouse serum IgG1 can be purified by such a simple procedure.

Animals↗

A new case of IgE myeloma (Des) ending with renal failure.

A new case of IgE myeloma (Des), a woman aged 55, is presented. The monoclonal Ig was identified as an IgE of the kappa type. The case history is detailed. Bone lesions were absent; there were up to 12% plasma cells in the peripheral blood; therapy with cytostatic drugs could not be applied because of leuco- and thrombopenia. The patient died of renal failure after having been maintained one year on steroids and transfusions. A comparison between several clinical and laboratory data of this new case, the twelfth to the author's knowledge, and those of the preceding ones, is also given.

Acute Kidney Injury↗

High levels of secretory IgA and free secretory component in the serum of rats with bile duct obstruction.

In the rat , ligation of the bile duct induces a rapid and progressive elevation of the IgA levels in serum. The increase is about 4-fold at 1 h, 15-fold at 1 day, and 30-fold at 1 wk after ligation. The additional IgA is of the secretory type. Free secretory component also appears in serum after bile duct obstruction; it does not continue to increase and occasionally disappears from serum after prolonged ligation. The increase in serum IgA levels is selective. These changes are totally reversible if the bile duct is reopened at 1 day after ligature. These findings confirm the role of the rat liver in the transfer of circulating IgA into the bile.

Animals↗

Rapid disappearance from serum of intravenously injected rat myeloma IgA and its secretion into bile.

Intravenously injected monoclonal rat IgA is first removed from rat serum at a very fast rate (93% in 4 h), then at a much slower rate (t/2 = 24 h). The rapid initial disappearance is thought to be due in part to secretion into rat bile. This was demonstrated by rat liver perfusions with semisynthetic medium containing diluted (1:200) IgA myeloma serum. During perfusion, the cannulated bile displayed increasingly high levels of this IgA, with a bile to medium ratio of 38 after 1 h of perfusion; at the same time, there was a 40% drop of the rat monoclonal IgA concentration in the medium, which was not observed for rat IgG2a and albumin. All of the monoclonal biliary IgA was bound to secretory component. The rat liver is thus able to actively secrete a monoclonal IgA from the circulation into bile against a strong concentration gradient.

Animals↗

Role of the liver in the rat intestinal s-IgA system.

Rat bile is an important source of s-IgA and FSC about 10 mg of s-IgA are poured daily in the duodenum via the bile. The normal rat liver is capable of actively transferring IgA from the circulation into bile against a strong concentration gradient. Circulating IgA transferred in bile was bound to SC. Ligature of the rat bile duct induces a large and selective increase of the IgA level in serum. All this additional IgA is s-IgA and even FSC appears in serum after bile duct obstruction. The liver appears to have an important reinforcing role in the intestinal s-IgA system of the rat.

Animals↗

Protein A reactivity of various mammalian immunoglobulins.

Serum samples and immunoglobulin fractions of eight mammalian species were applied to a Sepharose--protein A column. As with the human immunoglobulin subclasses IgG1, IgG2 and IgG4, all examined IgG classes and subclasses were bound to a greater or lesser extent to protein A. However, the binding of IgG1 of ruminants was very poor. Polyclonal IgM and IgA of the pig, the dog and the cat may be separated in protein A reactive and protein A non-reactive fractions. In addition, monoclonal canine IgM and IgA partially reacted with protein A. In combination with methods such as ammonium sulphate precipitation, ion exchange chromatography and gel-filtration, affinity chromatography with protein A is recommended for the rapid purification of certain Ig (sub)classes of a number of mammalian species.

Animals↗

Late appearance of an IgA (kappa) monoclonal protein in a patient with IgG (kappa) multiple myeloma: sharing of idiotypic specificities between the two serum proteins.

A patient with an IgG(chi) monoclonal serum protein developed in the course of the disease a second monoclonal spike of the same light chain type and of the IgA class. The latter monoclonal protein progressively increased and eventually exceeded the first IgG(chi) protein. Antigenic analysis of the two myeloma proteins demonstrated that they shared idiotypic determinants. Immunofluorescence studies, carried out with anti gamma and anti alpha reagents tagged with different fluorochromes revealed that the two isotypes were produced by different plasma cells. The data are discussed in the prospect of a possible transitional mechanism from IgG to IgA synthesis within a single B cell clone.

Female↗

Relevance of biliary IgA antibodies in rat intestinal immunity.

Two intraperitoneal administrations of foreign red cells in Freund's complete adjuvant, or two intragastric intubations of erythrocytes, given to rats at 15 days interval, both elicit the appearance of specific antibodies in bile and serum. When bile was compared to serum, the selective predominance of IgA antibodies in this secretion was observed for both the intraperitoneally and intragastrically immunized groups, being more pronounced for the orally immunized group when related to IgG or IgM antibodies. The IgA content of upper intestinal washings was roughly ten-fold smaller in rats with bile duct cannulation than in sham-operated controls. Altogether, the data demonstrate that bile IgA may significantly contribute to the secretory IgA system of the gut.

Animals↗

Rat bile as a convenient source of secretory IgA and free secretory component.

Rat hepatic bile contains three proteins as major constituents: secretory IgA (SIgA), free secretory component (FSC) and albumin. Traces of alpha-macroglobulin, transferrin, IgG and IgM are also detectable. The bile duct daily pours between 5-12 mg each of SIgA and FSC into the rat duodenum. The origin and function of these proteins in bile may represent important clues in the understanding of the SIgA system.

Animals↗

Immune complexes in the aqueous humor and serum.

The aqueous humor and serum of patients with various ocular diseases were analyzed for the occurrence of rheumatoid factor or immune complexes. Rheumatoid factor was detected by its direct agglutinating activity on IgG-coated particles (latex) and immune complexes were detected by their ability to inhibit exogenous rheumatoid factor or the subunit q of the first component of complement (Clq). Rheumatoid factor or inhibitory activity were found in the aqueous humor of nine of 11 patients with Fuchs' syndrome. In some patients who were examined two or three times, agglutination alternated with inhibition. Among 13 patients with endogeous uveitis, five had either agglutinating or inhibitory activities in their aqueous humor. The tests were also positive in the aqueous humor of three of seven patients with choroidal melanoma. A high titer of rheumatoid factor was found in the aqueous humor in an accidentally perforated eye that resulted in sympathetic ophthalmitis. No inhibitory or agglutinating activity was detected in the aqueous humor of 20 patients with senile immature cataract.

Agglutination↗

Three immunoglobulin classes in the pigeon (Columbia livia).

Three classes of immunoglobulins have been identified in the pigeon. IgG and IgM were purified from pigeon serum whereas IgA was isolated from pigeon hepatic bile. Pigeon IgG and IgM had the same properties and immunohistological distribution as their chicken homologues. Pigeon IgA was identified on the following grounds: (1) it contains the same light chains as pigeon IgM and IgG; (2) it is relatively abundant in exocrine secretions such as bile, egg white, cropmilk and intestinal fluid, whereas it is present only in small amounts in serum; (3) it occurs in the cytoplasm of the majority of the immunocytes from the intestinal mucosa; (4) its electrophoretic mobility and molecular size are similar to those of chicken IgA. Surprisingly, no immunoglobulin-containing cells could be detected in sections of the wall of the cropmilk gland, despite the high IgA content of the cropmilk.

Animals↗

The immunoglobulins of the turkey (Meleagris gallopavo). Isolation and characterization of IgG, IgM and IgA in body fluids, eggs and intraocular tissues.

The distribution of the immunoglobulins IgG, IgM, and IgA in turkey serum, bile, egg white, egg yolk, intestinal secretions, and some intraocular tissues has been studied. Just as in the chicken and the pigeon, IgG is the most abundant immunoglobulin in the serum and IgA in egg white, intestinal secretions and bile. In addition, IgM was detected in serum and egg white, and IgG in egg yolk, iris, vitreous body, and aqueous humor. The discussion deals with the importance of using purified immunoglobulin fractions and heavy-chain-specific antisera in disease studies in the turkey, specially in the case of infectious diseases which lead to the occurrence of "rheumatoid factors".

Animals↗