PubMed Health⌕ Search

Biomedical subjects

J P Vaerman

Publications and source records attributed to J P Vaerman.

At least 127 records · Page 7Linked to original sources
PubMed1984

High incidence of chromosome abnormalities in IgG3 myeloma.

Chromosomes were studied in 33 untreated myeloma patients, and results were correlated with the class of Ig secreted by the myeloma cells. A high incidence of clonal karyotypic anomalies seemed to be present in IgG3 myeloma patients, in whom the disease was advanced at diagnosis and rapidly progressing. Among the chromosome anomalies, the t(11;14)(q14;q32) was particularly prominent, and this chromosome anomaly, in analogy with the Ph1 chromosome, may characterize a family of lymphoproliferative disorders.

Adult↗
PubMed1984

Study of IgA in the cerebrospinal fluid of neurological patients with special reference to size, subclass and local production.

IgA was assayed by particle counting immunoassay in cerebrospinal fluid (CSF) from non-neurological and neurological patients. Reference values had a logarithmic normal distribution with a mean of 1.54 mg/l and an upper limit of 5 mg/l. To estimate the possible intra-blood-brain barrier (BBB) production of IgA we have calculated an IgA index: CSF-IgA/serum-IgA: CSF-albumin/serum-albumin. Values higher than the upper reference limit of 0.41 were found in 12 out of 67 patients with multiple sclerosis (18%), in 5 out of 11 with aseptic meningitis, in 7 out of 8 with herpetic encephalitis, in 1 out of 8 with Guillain-Barré syndrome and in 2 cases of tuberculous meningitis. However, this index does not take into account the relative proportions of monomeric and polymeric IgA in CSF and serum. We therefore ultracentrifuged 17 paired CSF and serum samples and determined the relative proportions of monomeric and dimeric IgA and calculated the indices for monomeric and dimeric IgA. In controls the proportion of dimeric IgA in CSF was below 5% of total IgA whereas this proportion was increased up to 53.9% in the case of intra-BBB production of IgA, which is thus characterized by a very high dimeric IgA index. In all cases IgA1 remained the predominant subclass. These results had to be compared with those observed in cultures of peripheral blood lymphocytes, which secrete about equal proportions of monomeric and polymeric IgA pertaining to the IgA1 subclass.

Herpesviridae Infections↗
PubMed1984

Immunohistochemical localization of secretory component in the liver of guinea pigs and dogs versus rats, rabbits, and mice.

Secretory component (SC) was localized in the liver of guinea pigs, dogs, rabbits, rats, and mice. In rabbits, rats, and mice SC localized predominantly in bile canaliculi and on hepatocyte sinusoidal membranes but was doubtful in cholangiocytes . In dogs and guinea pigs SC-staining was not detected in/on hepatocytes and canaliculi but was strong in/on cholangiocytes , as reported for humans. In guinea pigs IgA biliary output was small (0.23 mg/kg/day), as for dogs and humans, and below IgG output (1.4 mg), in contrast to rats, whose IgA biliary output (38 mg/kg/day) was much larger than IgG output (2mg). Biliary obstruction in guinea pigs induced only minor increases in serum IgA (+ 26% over 24 h), as reported for dogs and humans, in contrast to rats (+ 800% over 24h) and rabbits. Hepatocyte SC expression correlates with IgA hepatobiliary excretion, being low in guinea pigs, dogs, and humans but high in rats, rabbits, and mice.

Animals↗
PubMed1984

Secretion of immunoglobulins and plasma proteins from the jejunal mucosa. Transport rate and origin of polymeric immunoglobulin A.

Parameters of secretion of IgA and several other plasma proteins from the jejunal mucosa were investigated in 11 individuals who had a normal distribution of Ig-containing cells in the lamina propria and in one patient who was totally deficient in jejunal IgA and IgM plasmacytes. Jejunal samples were collected during segmental gut perfusion. The following results were obtained: (a) The secretion of polymeric IgA (p-IgA, mean equals 217 micrograms/40 cm per min) exceeded those of albumin (132 micrograms), IgG (35 micrograms), and monomeric IgA (m-IgA, 15 micrograms, or 6.4% of total IgA). About 35% of IgA was IgA2 in the jejunal secretion, compared with approximately 23% in serum. This closely corresponds to the 35 and 24% of IgA2 plasmocytes in jejunal mucosa and peripheral lymph nodes, respectively. (b) For each protein, a relative coefficient of excretion (RCE) was calculated (jejunum to serum concentration ratio expressed relative to that of albumin). RCEs of 1.41 for orosomucoid, 1.0 for albumin, 0.83 for IgG, and 0.74 for IgE and, in the deficient patient, of 0.64 for m-IgA and 0.016 for IgM were obtained. This was inversely related to the molecular weight of these proteins and indicated their predominantly passive transport into the jejunum. However, in normal individuals, the RCE of transferrin (approximately 1.11 greater than 1, P greater than 0.05), alpha 2-macro globulin (approximately 0.77), m-IgA (approximately 1.98), and p-IgA (approximately 218) exceeded the value expected from simple seepage from plasma, thus pointing to an additional role of either local gut synthesis and/or active transepithelial transport. (c) Approximately 98% of p-IgA, approximately 99% of IgM, and approximately 68% of m-IgA in jejunal secretions were derived from local production in the gut wall, as determined by 125I-p-IgA specific activities and/or by comparison between the RCE values of the deficient patient to the values of controls. Therefore, the jejunal production of p-IgA (approximately 312 mg/d per 40 cm vs. approximately 54 mg/d from bile) contributes the majority of upper intestinal IgA in humans. The active transport of plasma p-IgA across the intestinal mucosa (approximately 0.08 mg/40 cm per kg per d) contributes less than 2% of the total amount of p-IgA (4.5 mg/kg per d) that is cleared daily from plasma.

Adult↗
PubMed1984

Localization and serum concentration of secretory component during massive necrosis of human liver.

The serum concentration of secretory component was monitored in 9 patients with massive liver necrosis. During acute cytolysis, no increase in serum secretory component levels was observed. Later on, patients with fulminant evolution displayed minor elevations. Values as high as those usually found in acute hepatitis were only observed in cases with delayed liver failure. In these patients, levels were elevated before failure, dropped as liver failure developed, and rose again during recovery. This evolution of serum secretory component level cannot be accounted for by a defective liver clearance of circulating secretory component. It rather suggests a release into the blood of secretory component produced in the liver by cells other than damaged hepatocytes, possibly during liver regeneration. In 3 cases, secretory component localization in the liver was demonstrated by immunocytochemistry and was compared with that in normal liver and in obstructive jaundice. In normal liver, it was restricted to portal bile duct cells and lumens. In obstructive jaundice, additional secretory component staining was found in bile canaliculi. After fatal liver necrosis, secretory component was localized to portal ducts and to a variable proportion of the cholangiocytelike cells belonging to the numerous extraportal proliferating ducts. In these structures, 0.1%, 21%, and 4% of the cells were stained 3, 8, and 30 days after maximal cytolysis, respectively. Remaining hepatocytes and bile canaliculi or bile plugs were unstained. Therefore, portal cholangiocytes and extraportal cholangiocytelike cells are probably essential sources of secretory component in human liver. We propose that proliferation of extraportal cholangiocytelike cells, expression of secretory component synthesis by these cells, and their inability to secrete secretory component in a disorganized biliary tree result in the elevated serum concentration of secretory component observed after acute liver necrosis.

Acute Disease↗
PubMed1984

[Effector mechanisms of IgA].

Like all immunoglobulins (Ig), IgA has a double function: recognition of the antigen, situated in the Fab alpha fragments, and effector functions which allow elimination of the antigen (Ag), carried by the Fc alpha fragment. Secretory IgA ( IgAs ) is the principal Ig of external secretions and mucosae and has a different structure and composition from serum IgA. Its external function of protection against various forms of bacterial and viral aggression has been well established. Its general mechanism is "the immune exclusion of antigens" i.e. prevention of the penetration of the Ag into the organism by confining them to external secretions followed by elimination. The elimination of bacteria is facilitated by the immobilization and agglutination by IgA. Sometimes, with the aid of lysozyme, IgAs can be bacteriolytic. Antibacterial IgAs have a bacteriostatic function in synergy with lactoferrin and/or transferrin; they even reduce the bacterial production of siderophores. IgAs can inhibit bacterial adhesion to epithelial cells and can increase their adherence to mucus. The neutralization of viruses by IgA is due to inhibition of the first stage of infection, attachment and intracellular penetration of the virus. The same mechanism is involved in the neutralization of bacterial toxins. IgAs also decrease intestinal absorption of foreign proteins in the diet. It has been reported that antibacterial IgAs can cause certain bacteria to lose a plasmid which determines their infectivity. IgAs are able to protect themselves by neutralizing IgA1-proteases secreted by certain bacteria found on mucosal surfaces. Plasma IgA has a limited internal action compared to IgM or IgG. It is generally accepted that IgA barely activates complement (C) by the classical pathway and minimally opsonizes Ag for mono- and polymorphonuclear phagocytes. Antibacterial IgA are not bactericidal in the presence of complement and do not facilitate the phagocytosis of the bacteria to which they are attached. Certain unfavourable effector functions have even been described, such as a specific inhibition of complement fixation and bacterial lysis by IgM and IgG. Some IgA may non-specifically inhibit neutrophil chemotaxis as well as their bactericidal and phagocytic activities. It is difficult to believe that IgA, the second Ig (in quantity) in human serum, is simply useless or even harmful.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1984

Parameters influencing the expression of IgA antibodies in tears.

Rats were immunized repeatedly with dinitrophenylated type III pneumococcal vaccine by the intravenous (IV), subcutaneous (SC), gastrointestinal (GI), or ocular/topical (OT) routes at biweekly intervals. IgA anti-DNP antibodies were measured in serum, tears, saliva, bronchial, and intestinal washings, obtained 7 days after the third and sixth immunizations, using a solid phase radioimmunoassay. The GI route most effective at eliciting and maintaining IgA antibody responses in tears. The OT group displayed markedly diminished IgA response frequencies and antibody levels in tears following prolonged immunization. These data show that repeated central mucosal (gastrointestinal associated lymphoid tissue) stimulation maintains a local IgA response in tears, while continued topical antigen stimulation does not. Isoelectric focusing was used to probe the spectral complexity of the IgA antibodies of individual animals undergoing GI and OT immunization. The reduction of spectral complexity and the decreased responses following OT immunization appear to reflect a diminution of IgA antibody producing cells in the lacrimal gland. The concomitant changes in spectral components and maintenance of responsiveness of the GI group suggests that central mucosal site stimulation provides the lacrimal compartment with a continuous but variable population of IgA antibody producing cells.

Animals↗
PubMed1983

High proportion of polymeric IgA in young infants' sera and independence between IgA-size and IgA-subclass distributions.

The serum IgA in young infants (6-240 days old) comprised a much larger proportion (means = 36%; range, 7.5-72%) of polymeric IgA than in normal adults (means = 13%; range, 4.7-22%), but with a normal subclass distribution. In contrast, in IgA-deficient adult serum, there was a higher proportion (means = 34%; range, 16.3-38%) of IgA2 than in normal adult serum (means = 21%; range, 5-36%), with, however, a normal proportion of polymers. The distribution of IgA subclasses in the separated monomeric and polymeric IgA fractions was similar to that in unfractionated sera. The proportions of IgA polymers and IgA2 in serum are unlinked parameters, suggesting that both do not necessarily represent mucosal contributions to blood IgA.

Adult↗
PubMed1983

Changes in size, subclass, and metabolic properties of serum immunoglobulin A in liver diseases and in other diseases with high serum immunoglobulin A.

We have studied the relative contributions of monomeric (m-) and polymeric IgA (p-IgA) and of IgA1 and IgA2 to total serum IgA in healthy adults and patients with liver disease (LD) or with other diseases and high serum IgA. Serum concentration of total secretory component (SC) was also determined. In addition, fractional catabolic rates (FCR) and synthetic rates for both m- and p-IgA were measured in nine controls and nine cirrhotics. Our results support four main conclusions: (a) In healthy adults, intravascular p-IgA contributes to only 4-22% (mean 12%) of serum IgA, because its FCR and synthetic rate are approximately two times higher and four times smaller, respectively, than those of intravascular m-IgA. (b) in LD, biliary obstruction does not result in a significant increase in serum p-IgA unlike in rats and rabbits, indicating that in humans the SC-dependent biliary transport of p-IgA plays a much less significant role in selective removal of p-IgA from plasma than in rats and rabbits. (c) In contrast to biliary obstruction, parenchymal LD results in a significant and preferential increase in serum p-IgA, which in cirrhotics correlates with a selective reduction of the p-IgA-FCR. This supports a role for the human liver in selective removal of p-IgA from plasma, but another mechanism than the SC-dependent biliary transport should be considered. (d) Total SC, p-IgA, and IgA2 in serum are unlinked parameters, not necessarily reflecting mucosal events. A marked increase in serum SC occurs almost selectively in LD. Although a shift to IgA2 is suggested in Crohn's disease and alcoholic cirrhosis, a shift to IgA1 frequently associated to a shift to p-IgA occurs in chronic active LD, primary Sicca, and connective tissue diseases.

Adult↗
PubMed1982

Non-proteic immunogenic impurity in proteins purified by preparative electrophoresis on Pevikon.

Purified IgA proteins, obtained by zonal electrophoresis on blocks of Pevikon, contained an uncharged, non-proteic, water-soluble macromolecular impurity. The contaminant, which precipitates in half-saturated ammonium sulfate, could be an unknown derivative of polyvinyl alcohol. It was discovered because it induced the synthesis of specific precipitating antibodies in a rabbit used for antibody production against the electrophoresed protein, generating spurious precipitin reactions during its immunochemical analysis. Thorough washing of the Pevikon will substantially reduce the amount of impurity and the danger of obtaining precipitating antibodies against it after injection into animals.

Animals↗
PubMed1982

High serum levels of secretory IgA in liver disease: possible liver origin of the circulating secretory component.

Patients with liver disease frequently display unexplained elevations of serum secretory IgA (sIgA). The sIgA levels in various liver diseases were compared to various biochemical or clinical parameters. Patients with primary biliary cirrhosis, biliary tract obstruction, or acute hepatitis displayed highest sIgA levels. In chronic parenchymal liver disease sIgA levels correlated strongly with serum alkaline phosphatase (r = 0.79), leucine aminopeptidase (r = 0.83), and direct bilirubin levels (r = 0.63), but not with prothrombin time, aminopyrine breath test, or presence of portacaval shunting. In acute hepatitis sIgA correlated best with serum glutamic oxaloacetic transaminase (r = 0.69) but not with bilirubin; in four patients with fulminant hepatitis, sIgA fell rapidly together with all liver enzymes and prothrombin time; it rose quickly again in one patient when parenchymal regeneration occurred. These results suggest a hepatobiliary origin of the serum sIgA in liver disease. In acute hepatitis the persistence of hepatocytes seems necessary for maintaining high serum sIgA levels, suggesting a possible hepatocyte origin of the secretory component.

Adolescent↗
PubMed1982

Influence of molecular size of IgA on its immunoassay by various techniques. II. Solid-phase radioimmunoassays.

Homogeneous, polymeric (P), monoclonal (MC) and polyclonal (PC) samples of purified IgA, as well as of secretory IgA (sIgA), were compared to their corresponding monomeric (M) forms with regard to their respective behaviour in both a solid-phase double antibody (AB) immunoradiometric assay (IRMA) and a solid-phase competition radioimmunoassay (CRIA). On an identical weight basis, both assays underestimated the P forms. Correction factors (CF), i.e., optical density (OD) versus radiometric concentration ratios, were calculated for both methods for all P forms, using M as standards. IRMA CF were respectively 1.50 for dimer, 1.98 for secretory IgA and 2.40 for tetramers, very similar to those obtained in radial immunodiffusion (RID). With optimally coated beads, these CF were stable along a wide range of concentrations. In contrast, CRIA-CF were 3-4 times larger and displayed much variation along their standard range of concentrations, preventing the use of a constant CF along the standard curve. Our present IRMA, with its CF, should be of value for a more accurate quantitation of small amounts of IgA of various known sizes.

Bile↗
PubMed1982

Influence of molecular size of IgA on its immunoassay by various techniques. III. Immunonephelometry.

The influence of size heterogeneity of IgA on its immunonephelometric (IN) assay was studied using highly purified preparations of monoclonal (MC) or polyclonal (PC) monomeric (M), dimeric (D), trimeric (T) and tetrameric (Q) IgA, as well as of secretory IgA (sIgA). Concentrations measured by optical density (OD) were compared to IN--concentrations obtained by using M as standards, on an equal weight basis. No significant difference was found between OD and IN concentrations of D, T, Q and sIgA were only slightly underestimated, with correction factors (CF) of 1.16, 1.20 and 1.24, respectively. The value of 1.24 for our sIgA sample (84% of 11S, 16% of 15S) could be due to the fact that secretory component represents about 20% of the mass of the sIgA molecule. IN seems a method of choice for measuring IgA concentrations in the range of microgram/ml, almost independently of the size of IgA.

Animals↗
PubMed1982

Influence of molecular size of IgA on its immunoassay by various techniques--I. Direct and reversed single radial immunodiffusion.

Immunochemically pure samples of monoclonal and polyclonal IgA were prepared from human sera and milk. Samples of various homogeneous molecular sizes were further obtained by preparative ultracentrifugations. The different behaviour of each preparation (monomer, dimer, trimer, tetramer and secretory IgA) were studied in direct (DRID) and reversed (RRID) single radial immunodiffusion using three different anti-alpha-chain antisera and IgA samples of various monoclonal and polyclonal origins. In DRID, all polymer concentrations were underestimated when using monomers as standards, on an equal weight (OD) basis. Correction factors (CFs) were calculated from monomer to polymer DRID slope ratios. The means +/- SDs of these CFs were 1.55 +/- 0.18 for serum dimers, 1.85 +/- 0.10 for trimers, 2.63 +/- 0.26 for tetramers and 2.24 +/- 0.15 for secretory IgA (84% 11S, 16% 15S). These results were confirmed by RRID.

Antibodies, Monoclonal↗
PubMed1982

Immunoglobulins in rabbit hepatic bile: selective secretion of IgA and IgM and active plasma-to-bile transfer of polymeric IgA.

Proteins in hepatic bile from cannulated rabbits were analysed by gel filtration, electrophoresis, density gradient ultracentrifugation, and immunochemical methods. Bile-to-serum concentration ratios (no. = 8) demonstrated that IgA and free secretory component (SC) were major constituents of rabbit bile. Relative concentration ratios, obtained by dividing the bile to serum level ratio for each protein by the corresponding ratio for albumin, were 310, 1.6, 1.0, 0.82, and 0.54 for IgA, IgM, albumin, transferrin, and IgG respectively, suggesting that both IgA and IgM are selectively secreted into bile. Ligation of the bile duct (no. = 5) led to a selective increase of the serum levels of IgA and SC, the latter as secretory IgA. After intravenous injection (no. = 4) of human polymeric IgA, 37-69% of the injected dose was recovered in bile after 3 h, in contrast to 4-5% for human monomeric IgA. The active transfer of both rabbit and human polymeric IgA into rabbit bile occurs via the same hepatic SC-mediated transport process as that described for the rat.

Animals↗