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Immunology Aug 1986Affinity maturation was studied by the analysis of the kinetics of the appearance of antibody subpopulations with different affinities during the immune response, using...
Affinity maturation was studied by the analysis of the kinetics of the appearance of antibody subpopulations with different affinities during the immune response, using an hapten-inhibition ELISA. The immune response in KLH-Ar-immunized A/J mice was used as a model system. Five antibody subpopulations of different affinity (10(3)-10(7) M-1) could be detected, the relative concentrations of which changed during affinity maturation. The high-affinity antibody subpopulations did not represent the major fraction at any stage during affinity maturation. The appearance of the highest affinity subpopulation (10(7) M-1), despite exhibiting relative concentrations no higher than 12%, produced an important increase in average affinity. On the other hand, its disappearance at the end of the maturation process could explain the average affinity decrease observed at this stage. Our results indicate that affinity maturation cannot be explained by the dominance of high-affinity clones, as proposed by Siskind & Benacerraf (1969). The increase in affinity could rather be due to the progressive appearance of low percentages of high-affinity clones, which are not present in the primary response and never become dominant.
Topics: Animals; Antibody Affinity; Antibody Formation; Antigens; Arsanilic Acid; Arsenicals; Enzyme-Linked Immunosorbent Assay; Hemocyanins; Kinetics; Mice; Mice, Inbred Strains
PubMed: 3733154
DOI: No ID Found -
Canadian Journal of Veterinary Research... Jul 1986Swine dysentery did not recur during a nine week period after withdrawal of medication in swine fed ronidazole at a level of 60 parts per million of feed for ten weeks...
Swine dysentery did not recur during a nine week period after withdrawal of medication in swine fed ronidazole at a level of 60 parts per million of feed for ten weeks or fed either carbadox at 55 ppm or lincomycin at 110 ppm of feed for six weeks. During this period swine dysentery was neither transmitted to accompanying sentinels after the withdrawal of the above medication or was Treponema hyodysenteriae isolated and cultured or observed in stained smears from rectal swabs and feces or from colonic scrapings at necropsy. Beginning three weeks after the withdrawal of medication, all swine were fed sodium arsanilate at a concentration of 220 ppm of feed for three weeks in an attempt to excite the carrier of swine dysentery into developing a swine dysentery diarrhea. A swine dysentery diarrhea did recur during the feeding of sodium arsanilate in swine previously fed ronidazole at a level of 60 ppm of feed for only six weeks. It was concluded: that swine dysentery was probably eliminated with the feeding of ronidazole for the longer duration and with the feeding of carbadox and lincomycin and that sodium arsanilate was of value in identifying the carrier state.
Topics: Animals; Arsanilic Acid; Arsenicals; Carbadox; Carrier State; Dysentery; Lincomycin; Nitroimidazoles; Quinoxalines; Ronidazole; Swine; Swine Diseases; Treponemal Infections
PubMed: 3742373
DOI: No ID Found -
Canadian Journal of Veterinary Research... Jul 1986Sodium arsanilate was fed to nondiarrhetic swine, previously exposed to and treated for swine dysentery, for the purpose of inducing them into developing a swine...
Sodium arsanilate was fed to nondiarrhetic swine, previously exposed to and treated for swine dysentery, for the purpose of inducing them into developing a swine dysentery diarrhea. From 40 to 100% of these swine in each pen had previously had a swine dysentery diarrhea. The isolate of Treponema hyodysenteriae in the diced colon which was used to expose the swine was resistant to sodium arsanilate. After an interim of no treatment for swine dysentery, sodium arsanilate was fed at a level of 220 parts per million for 21 days. Of the 14 pens containing swine fed sodium arsanilate, ten pens had one or more swine that developed a swine dysentery diarrhea while being fed sodium arsanilate. This was significantly (P less than 0.05) greater than the three pens that each had one pig that developed a swine dysentery diarrhea of 13 pens containing similar swine not fed sodium arsanilate during a comparable period. In the 14 pens containing swine fed sodium arsanilate, 14 swine were the first to develop a swine dysentery diarrhea since in four pens, two swine in each pen developed diarrhea within 24 hours of each other. This also was significantly (P less than 0.01) greater than the three swine in the ten pens not fed sodium arsanilate. From these results, it was theorized that sodium arsanilate excited the nondiarrhetic carrier into developing a swine dysentery diarrhea and that this phenomenon may have potential in identifying the carrier state.
Topics: Animals; Arsanilic Acid; Arsenicals; Carrier State; Dysentery; Swine; Swine Diseases; Treponemal Infections
PubMed: 3742372
DOI: No ID Found -
Antimicrobial Agents and Chemotherapy Jan 1985The in vitro activities of 47 antimicrobial agents against 30 isolates of Campylobacter species from pigs were determined by the agar dilution technique. The isolates...
The in vitro activities of 47 antimicrobial agents against 30 isolates of Campylobacter species from pigs were determined by the agar dilution technique. The isolates were obtained from pigs with proliferative enteritis and included 10 strains each of Campylobacter coli, Campylobacter sputorum subsp. mucosalis, and "Campylobacter hyointestinalis Gebhart et al." (this name is not on the Approved Lists). Carbadox, furazolidone, nitrofurantoin, gentamicin, and dimetridazole were the most active drugs, inhibiting all three Campylobacter species with a MIC for 50% of the isolates of 2 micrograms/ml or less. Trimethoprim-sulfamethoxazole, cefazolin, sulfachloropyridazine, novobiocin, vancomycin, sulfathiazole, cyclohexamide, bacitracin, p-arsanilic acid, and colistin were the least active, with MICs for 50% of the isolates ranging from 16 to greater than or equal to 128 micrograms/ml.
Topics: Animals; Anti-Bacterial Agents; Campylobacter; Campylobacter Infections; Culture Media; Enteritis; Microbial Sensitivity Tests; Swine; Swine Diseases
PubMed: 3985597
DOI: 10.1128/AAC.27.1.55 -
Poultry Science Oct 1984Five experiments were conducted to evaluate the effects of diet and antimicrobials on weight gain, feed efficiency, ileal weight, and Clostridium perfringens in the... (Comparative Study)
Comparative Study
Five experiments were conducted to evaluate the effects of diet and antimicrobials on weight gain, feed efficiency, ileal weight, and Clostridium perfringens in the ileum of broiler chicks. In the first experiment, glucose, sucrose, and fructose were added to a semipurified diet and the results were compared with those from a practical corn and soybean meal diet. All of the diets were fed with and without bacitracin at a level of 55 ppm. Fructose resulted in the greatest depression in weight gain, followed by sucrose. Bacitracin significantly improved weight gain and feed efficiency of chicks fed the fructose, sucrose, and practical diets. Highly significant inverse correlations were obtained between ileal weight and weight gain and the number of C. perfringens in the ileum and weight gain. In other experiments bacitracin, penicillin, chlortetracycline, oxytetracycline, erythromycin, tylosin, virginiamycin, lincomycin, bambermycins, and carbadox, all at a level of 55 ppm, improved weight gain and feed efficiency and significantly reduced the weight of the ileum and the number of C. perfringens in the ileum of chicks fed the practical diet. The antibacterial agents 3-nitro-4-hydroxy-phenylarsonic acid, arsanilic acid, furazolidone, and sulfathiazole had little to no effect on the 4 parameters evaluated. Virginiamycin and lincomycin at 16.5 and 4.4 ppm, respectively, were shown to be effective. In vitro activities of the antimicrobials against C. perfringens did not directly relate to in vivo activities and the effects on growth and feed efficiency. The results of these experiments support the concept of antimicrobials as growth permittants and provide further evidence for C. perfringens as a causative bacteria for growth depression.
Topics: Animal Feed; Animals; Anti-Bacterial Agents; Bacitracin; Body Weight; Chickens; Clostridium perfringens; Dietary Carbohydrates; Energy Metabolism; Food Additives; Fructose; Glucose; Ileum; Male; Organ Size; Sucrose
PubMed: 6093090
DOI: 10.3382/ps.0632036 -
The Journal of Experimental Medicine Oct 1983We describe a sequence of reciprocal interactions between cloned inducer T cells and antigen-presenting cells (APC) that results in selective depletion of the...
We describe a sequence of reciprocal interactions between cloned inducer T cells and antigen-presenting cells (APC) that results in selective depletion of the antigen-reactive inducer cells. We show that corecognition of antigen and I-A by hapten-reactive inducer T cell clones results in (a) release of macrophage-activating factor (MAF) and other lymphokines, (b) expression of lytic activity by a subset of MAF-sensitized APC after triggering, and (3) lysis (mediated by the activated and triggered macrophage) of the inducer T cell clone and other cells in the vicinity. We suggest that this sequence of steps may limit the extent of macrophage-mediated tissue destruction by depleting the specific inducer T cell clones that initiate the response.
Topics: Animals; Arsanilic Acid; Cell Line; Clone Cells; Cytotoxicity, Immunologic; Epitopes; Female; Lymphocyte Cooperation; Lymphocyte Depletion; Lymphokines; Macrophage Activation; Macrophage-Activating Factors; Macrophages; Mice; Mice, Inbred A; Mice, Inbred BALB C; Mice, Inbred C57BL; Spleen; T-Lymphocytes
PubMed: 6194244
DOI: 10.1084/jem.158.4.1243 -
Proceedings of the National Academy of... Jan 1982A number of monoclonal antibodies have been used to investigate the distributions and rates of lateral motion of the HLA-A,B, and-DR antigens on several Epstein--Barr...
A number of monoclonal antibodies have been used to investigate the distributions and rates of lateral motion of the HLA-A,B, and-DR antigens on several Epstein--Barr virus-transformed B-cell lines. The lateral diffusion coefficients (D) of fluorescein conjugates of the monoclonal antibodies bound to the cell surface were determined by fluorescence recovery after pattern photobleaching. Ds of HLA-A and-B were found to be comparable and of the order of 10(-9) to 10(-10) cm2/sec for each of the seven monoclonal antibodies and four cell lines examined. The HLA antigens appear to be monomeric on the cell surface based on experiments using mixtures of arsanilic acid-conjugated and fluorescein-conjugated antibodies. Four monoclonal antibodies against DR antigens were examined. Two of these, Genox 3.53 and L243, labeled the cell surface uniformly and gave Ds comparable to those obtained for the HLA-A and -B antigens. The other two, DA2 and 2.06, rapidly patched on the cell surface and were immobile. The DA2, L243, and Genox 3.53 antibodies bound outside of the caps formed with the arsanilic acid-conjugated 2.06 antibody and a second-step rhodamine-conjugated rabbit anti-arsanilate antibody. This is consistent with recent biochemical evidence that there are multiple distinct antigens coded for by the HLA-DR region.
Topics: Antibodies, Monoclonal; Cell Line; Cell Transformation, Viral; Diffusion; HLA Antigens; Herpesvirus 4, Human; Humans; Immunologic Capping; Membrane Proteins
PubMed: 6281776
DOI: 10.1073/pnas.79.2.608 -
The Journal of Experimental Medicine May 1981Painting mice on the skin with the diazonium salt of p-arsanilic acid elicited two types of T cell activity. One was restricted by the I region of the major...
Painting mice on the skin with the diazonium salt of p-arsanilic acid elicited two types of T cell activity. One was restricted by the I region of the major histocompatibility complex and was responsible for the transfer of azobenzenearsonate (ABA) sensitivity to naive mice. The other was H-2K restricted and could be demonstrated by its ability to interact specifically with ABA-coupled cells in vitro and to inhibit nonspecifically the transfer of sensitivity by cells sensitized either to ABA or to another antigen. Free antigen, or antibody directed against the cross-reactive idiotype on the anti-ABA antibodies of A/J mice, could inhibit the H-2K-restricted suppressive activity induced in the ABA immune A/J cells.
Topics: Animals; Antigens; Azo Compounds; Cross Reactions; H-2 Antigens; Haptens; Hypersensitivity, Delayed; Mice; Spleen; T-Lymphocytes; T-Lymphocytes, Regulatory; p-Azobenzenearsonate
PubMed: 6454743
DOI: 10.1084/jem.153.5.1124 -
The Journal of Biological Chemistry Dec 1979
A peptidase-inactive derivative of carboxypeptidase A modified specifically at tyrosine 248. Cobalt(III) (ethylenediamine-N,N'-diacetato) (arsanilazotyrosinato 248 carboxypeptidase A).
Topics: Animals; Arsanilic Acid; Binding, Competitive; Carboxypeptidases; Cattle; Cobalt; Ethylenediamines; Kinetics; Pancreas; Structure-Activity Relationship; Tyrosine
PubMed: 574142
DOI: No ID Found -
Antimicrobial Agents and Chemotherapy Mar 1979The in vitro activities of 39 antimicrobial agents against 23 isolates of Treponema hyodysenteriae, the majority of which were field isolates, were determined by the...
The in vitro activities of 39 antimicrobial agents against 23 isolates of Treponema hyodysenteriae, the majority of which were field isolates, were determined by the agar dilution technique. Quinoxalines, pleuromutilin, nitroimidazoles, and nitrofuran were the most active. Their activities ranged from =0.10 to 1.56 mug/ml. Lincomycin, penicillins, chloramphenicol, tetracyclines, cephalosporins, three peptides (virginiamycin, thiopeptin, and bacitracin), and one aminoglycoside (gentamicin) exhibited intermediate levels of activity ranging from 0.39 to 50 mug/ml. Four peptides (enduracidin, viomycin, bicyclomycin, and colistin), three aminoglycosides (kanamycin, streptomycin, and neomycin), polyene, and other agents, including novobiocin, vancomycin, rifampin, nalidixic acid, and p-arsanilic acid, displayed limited activities ranging from 12.5 to >/=100 mug/ml. Macrolides showed varying degrees of activity depending upon isolates.
Topics: Anaerobiosis; Anti-Bacterial Agents; Culture Media; Feces; Microbial Sensitivity Tests; Treponema
PubMed: 464566
DOI: 10.1128/AAC.15.3.392