Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Antitoxins”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1978

Titration of tetanus antitoxin by passive hemagglutination. II. Serological characteristics of antitoxin production in rabbits and monkeys.

1) Production of tetanus antitoxin in rabbits and monkeys was followed by passive hemagglutination (HA) and toxin-neutralization (TN) tests. The HA activity was observed in both IgM and IgG in both animal species. 2) In rabbits, IgM antitoxin was detected as early as in 7 days, reached the maximum titer in 10--14 days, and disappeared in 3 weeks after the primary immunization. Antitoxin of IgG class was detected in 10 days, and increased gradually. The ratio of HA/TN titers ("serum ratio") was high at an early stage of primary immunization and approached the unity in 3--4 weeks. Unlike the case of guinea pigs, IgM was found to contribute greatly to this high level of ratio. Besides, most rabbits produced IgG antitoxin of high ratios at early stages of immunization. 3) The immune response of monkeys showed a pattern very similar to that of rabbits except a few days' delay in the time course of antitoxin titers. No IgG antitoxin with a high serum ratio was demonstrated. Therefore, the high serum ratio of early sera could be accounted for mainly by IgM. 4) In response to the secondary immunization, no IgM antitoxin was detected in either animal species. 5) No definite correlation between serum ratio and avidity in terms of "dilution ratio" was demonstrated. However, both the dilution ratio and serum ratio were high at an early stage of immunization and gradually decreased, though the magnitudes of the ratios were variable depending on individual animals.

Animals↗
PubMed1977

Escherichia coli heat-labile enterotoxin: comparison of antitoxin assays and serum antitoxin levels.

The mouse adrenal tumor cells (Y-1 strain) and the Chinese hamster ovary cells, two routinely used tissue culture assays for Escherichia coli heat-labile enterotoxin (LT), were used to detect serum antitoxin responses in culture-positive patients from several well-defined sources. There was no correlation between a significant antitoxin response and isolation of LT-producing E. coli in two "domestic" diarrheal outbreaks. Serum samples from a third group of individuals in a rural cholera-endemic area consistently demonstrated significant rises in neutralizing antibody to LT.

Antibodies, Bacterial↗
PubMed1978

Induction of a mucosal antitoxin response and its role in immunity to experimental canine cholera.

The induction of a jejunal antitoxin response was studied in dogs immunized with cholera toxin or toxoid. Single doses of toxoid given subcutaneously (s.c.) or of toxin given intraluminally (i.l.) were each effective in priming the mucosal immune system, whereas toxoid given i.l. was much less effective. In contrast, toxin and toxoid given i.l. were each effective as booster antigens. The local secondary response was rapid and brief, the peak occurring at about 7 days after i.l. boosting and declining by 90% after 2 more weeks. After s.c. priming and i.l. boosting with toxoid, antitoxin-containing plasma cells appeared predominantly in the portion of jejunum exposed to the i.l. booster. The appearance of antitoxin-containing plasma cells in jejunal lamina propria correlated with the amount of antitoxin recovered in jejunal washings which, in turn, correlated with protection against challenge with cholera toxin. Thus, lamina propria antitoxin-containing plasma cells appeared to be the source of protective antitoxin. However, after sequential s.c.-oral immunization with toxoid, protection against challenge with Vibrio cholerae far outlasted the major systemic and local antitoxin responses and was not obviously explained by either. These studies reveal methods for induction of a mucosal antitoxin response, but leave in question the mechanism of prolonged protection induced by s.c.-oral immunization of dogs.

Animals↗
PubMed1978

Neutralization of Clostridium difficile toxin by Clostridium sordellii antitoxins.

Neutralization of Clostridium difficile toxin by Clostridium sordellii antitoxin was studied by cytotoxicity assay in tissue culture. The sources of toxin were stools from two patients with pseudomembranous colitis and a culture filtrate of C. difficile isolated from one of the patients. C. sordellii antitoxin was available either in monovalent form or as gas gangrene polyvalent antitoxin. The potency of antitoxins against C. difficile determined by cytotoxicity assay did not correlate with the established values reported for mouse protection tests against C. sordellii toxin. An equivalent zone of optimal neutralization was demonstrated for stool toxin, and a slightly different one for culture toxin. The rate of neutralization appeared to be instantaneous, either at 24 or at 37 degrees C. The efficacy of antitoxin in preventing cytotoxicity in cultured cells preexposed to toxin decreased rapidly with preexposure time. The union between toxin and antitoxin could be readily dissociated by simple dilution or by ammonium sulfate precipitation followed by dissociated by simple dilution or by ammonium sulfate precipitation followed by dilution. Continued incubation of toxin-antitoxin mixture did not increase the firmness of the union; on the contrary, more dissociation occurred. The unusual looseness of the toxin-antitoxin union is probably relatd to lack of serological specificity or affinity. Based on these observations, a practical diagnostic method for antibiotic-induced colitis is outlined.

Antitoxins↗
PubMed1979

Prevention of clindamycin-induced colitis in hamsters by Clostridium sordellii antitoxin.

Toxins produced by Clostridium difficile have been implicated in the etiology of antibiotic-induced colitis. Clostridium difficile antitoxin is not available, but recent studies have shown that toxins present in the feces of patients with this disease are neutralized by Clostridium sordellii antitoxin. We found that C. sordellii antitoxin neutralized toxins produced in broth cultures of either C. sordellii or C. difficile and that passive immunization with C. sordellii antitoxin before challenge with clindamycin prevented colitis in hamsters. Significantly fewer antitoxin-treated animals than unimmunized controls developed diarrhea and died with hemorrhagic colitis. Administration of 300 U of antitoxin parenterally either on the day of challenge with clindamycin or 24 hr later provided significant protection (25% mortality vs. 100% mortality in controls, P less than 0.01). None of eight animals given antitoxin (300 U) both on the day of challenge and 24 hr later died. Filtrates prepared from cecal contents of dead or killed hamsters were tested for toxicity by intraperitoneal injection into hamsters and by addition to monolayers of monkey kidney cells. Fecal filtrates from antitoxin-protected animals were not toxic in these assays, but filtrates from control animals were uniformly toxic. Passive immunization against clostridial toxins was protective against clindamycin-associated colitis in this model. This finding further substantiates the importance of these toxins in the pathogenesis of antibiotic-induced colitis.

Animals↗
PubMed1976

[Several properties of low-molecular weight tetanus antitoxin].

Following intravenous injection of tetanus antitoxin, obtained by tryptic digestion of the horse immunoglobulin "Diaferm-3", purification and concentration of active fragments, the antitoxin was eliminated from the rabbit organism three times more rapidly than after the injection of the original "Diaferm-3" antitoxin. After injection of the split antitoxin its urinary excretion lasted up to 6 days, whereas following injection of the "Diaferm-3" antitoxin it was excreted for up to 19 days; in the first case considerably less antitoxin was excreted than in the second one (2 and 3.5%, respectively). In both cases in the antitoxin excreted with urine represented monovalent. Fab'-fragments, producing a delay in precipitation in the cross reaction in agar gel between the tetanus toxoid and the tetanus antiserum. Fab'-fragment obtained by the mentioned method possessed anaphylactogenic properties.

Animals↗
PubMed1977

Passive protection by antitoxin in experimental Pseudomonas aeruginosa burn infections.

The protective effect of intravenously administered rabbit antitoxin serum was studied in lethal Pseudomonas aeruginosa burn infections in mice. Survival after infection with 2 median lethal doses of a toxigenic, low-protease-producing strain (PA103) was enhanced in antitoxin-treated mice, as compared with controls that had received anti-bovine serum albumin serum (P = 0.0004). Survival time was prolonged in other antitoxin-treated mice infected with toxigenic, high-protease-producing strains (PA86 and PA220, P = 0.0003 and P = 0.01, respectively). In contrast, antitoxin had no protective effect in mice challenged with a nontoxigenic strain (WR 5, P = 0.57). There were fewer viable bacteria in blood and liver of antitoxin-treated mice than in those of anti-bovine serum albumin-treated controls after infection with toxigenic organisms, whereas there were no significant differences between the two groups after challenge with the nontoxigenic strain. These data suggest that P. aeruginosa exotoxin A contributes to lethality in this burn infection model, and this effect is diminished by passive immunization with antitoxin.

Animals↗
PubMed2016

Toxin-Antitoxin Systems of Staphylococcus aureus.

Toxin-antitoxin (TA) systems are small genetic elements found in the majority of prokaryotes. They encode toxin proteins that interfere with vital cellular functions and are counteracted by antitoxins. Dependent on the chemical nature of the antitoxins (protein or RNA) and how they control the activity of the toxin, TA systems are currently divided into six different types. Genes comprising the TA types I, II and III have been identified in Staphylococcus aureus. MazF, the toxin of the mazEF locus is a sequence-specific RNase that cleaves a number of transcripts, including those encoding pathogenicity factors. Two yefM-yoeB paralogs represent two independent, but auto-regulated TA systems that give rise to ribosome-dependent RNases. In addition, omega/epsilon/zeta constitutes a tripartite TA system that supposedly plays a role in the stabilization of resistance factors. The SprA1/SprA1AS and SprF1/SprG1 systems are post-transcriptionally regulated by RNA antitoxins and encode small membrane damaging proteins. TA systems controlled by interaction between toxin protein and antitoxin RNA have been identified in S. aureus in silico, but not yet experimentally proven. A closer inspection of possible links between TA systems and S. aureus pathophysiology will reveal, if these genetic loci may represent druggable targets. The modification of a staphylococcal TA toxin to a cyclopeptide antibiotic highlights the potential of TA systems as rather untapped sources of drug discovery.

Antitoxins↗
PubMed1978

Toward the development of a standard reference cholera antitoxin.

The need for a reference cholera antitoxin to serve as a standard for the calibration of cholera enterotoxin and toxoid as well as for measurement of the antitoxin response in animals and patients was recognized by the NIH Cholera Advisory Committee, NIAID, DHEW, USA. Two cholera antitoxins have been used for several years as provisional references, but neither was considered to embody all of the properties of an ideal standard. Accordingly, a lot of cholera antitoxin was prepared by immunization of goats with a formalinized, highly purified cholera toxin adsorbed on aluminum phosphate adjuvant. Booster injections were given at 8, 16 and 24 weeks. Plasma samples obtained from the 25 to 27 week bleedings were converted to serum, pooled, and freeze-dried. This serum possessed both high and constant toxin neutralizing activity in rabbit skin, rabbit ileal segment, mice, Y-1 adrenal cells and Chinese hamster ovary cells, and had high avidity by the rabbit skin assay. Hemagglutination tests gave identical values. It was shown to be highly specific by gel diffusion, but flocculation was relatively poor. On the basis of specificity, high avidity and toxin-neutralizing capacity this goat antitoxin (NIH Lot 1) was considered superior to previous provisional standards and is proposed as a satisfactory standard reference reagent.

Antibodies, Bacterial↗
PubMed1978

Diphtheria and tetanus antitoxin levels in Thai children.

Determination of diphtheria and tetanus antitoxin levels by an indirect haemagglutination method were conducted in 101 nonimmunized schoolchildren, 155 pediatric patients and 102 blood donors. Diphtheria and tetanus antitoxin levels were found mostly adequate among immunized children. Diphtheria antitoxin levels were found adequate in 68.3% of the non-immunized schoolchildren. Tetanus antitoxin levels were found inadequate for protection in the non-immunized children and adults. Immunization of children and adults with diphtheria and tetanus toxoid are highly recommended.

Adult↗
PubMed1978

[Tetanus antitoxin in serum and cerebral spinal fluid in viral meningitis in children (author's transl)].

Tetanus antitoxins were measured in serum and cerebro spinal fluid from 58 children--35 boys and 23 girls--with viral meningitis. The concentrations of IgG, IgA and IgM were also determined. The appearance of tetanus antitoxins in cerebral spinal fluid depends on absolute antitoxin levels in serum as well as on the antitoxin/IgG ratio. Antitoxin/IgG ratios in serum and cerebro spinal fluid were in the same order of magnitude. Detection of tetanus antitoxins in the cerebral spinal fluid of children with viral meningitis shows clearly that antibody found in cerebral spinal fluid is not an absolute proof of a certain disease. The results further indicate that local production of IgG antibody cannot be postulated by detecting certain antibodies in the CSF. It is also necessary to prove that antibody/globulin ratios are of significantly different magnitude in serum and CFS.

Adolescent↗
PubMed1976

A comparison of the evolution of transmitted IgG immunoglobulin and diphtheria antitoxin titers in the newborn.

The evolution of the titers of transmitted IgG and diphtheria antitoxin was studied in 20 neonates during the first 2 months of life (6 serum samples for each). A rapid fall of the passive IgG titer was observed during the first weeks: as a rule the higher the initial titer the greater the fall. After the 15th day the rate of decline slows down. The evolution of the titer of transmitted maternal diphtheria antitoxin depends also on the initial level, and if it is low it can remain more or less constant for a long time. The initial level of passive IgG does not influence the drop in diphtheria antitoxin titre and vice versa. Therefore, the evolution of total IgG and diphtheria antitoxin levels appear not to be interdependent.

Age Factors↗
PubMed1977

Humoral immune response to the heat-labile enterotoxin of Escherichia coli in naturally acquired diarrhea and antitoxin determination by passive immune hemolysis.

Acute- and convalescent-phase sera from 132 students attending a university in rural Mexico were assayed for antibody against the heat-labile enterotoxin (LT) of Escherichia coli by neutralization of LT activity in the Y-1 adrenal cell assay and by passive immune hemolysis of LT-sensitized sheep erythrocytes. The two titration methods produced comparable results with respect to antitoxin responses detected. An inverse relationship was found between acute geometric mean antitoxin titer and the occurrence of diarrhea associated with LT-producing E. coli, especially in newly arrived students from the U.S.A. A significant correlation (P less than 0.00 5) was found between a rise in antitoxin titer detectable by the passive immune hemolysis technique and diarrhea with LT-producing E. coli isolated. Thus, humoral antitoxin titers appear to be a useful indicator of immune status with respect to enterotoxigenic (LT) E. coli diarrhea.

Adult↗
PubMed1976

Botulinum antitoxins and antibacterial IgM and IgG antibodies in sera of persons immunized with botulinum polytoxoid combined with cholera vaccine. I. Response to botulinum toxoid.

Two groups of subjects were immunized with combined vaccine containing aluminum hydroxide-adsorbed botulinum toxoids, types A, B, and E, and 4 mld of formaldehyde-inactivated V. cholerae Inaba and Ogawa organisms. The first group included laboratory workers who were previously immunized against cholera and had professional contact with botulinum toxins and viable V. cholerae organisms. The second group included young men who were never vaccinated against botulism or cholera. The three-dose immunization schedule with combined vaccine resulted in clear-cut antitoxin response; after the third dose, the A, B, and E antitoxin level ranged from 0-2 to 10 IU/ml. Immunity against botulinum toxins lasted at least one year. Distribution of the antitoxins among IgM and IgG globulin classes resembled that in the case of response to other toxoids; 21 days after the third immunization antitoxin activity was found in IgG globulins.

Adult↗
PubMed1979

Levels of exfoliatin antitoxin in pooled human serum globulin.

The potential value of human serum globulin for treatment of patients with the staphylococcal scalded-skin syndrome was determined by measuring the exfoliatin antitoxin content of globulin pools. Of 16 lots tested, only four had detectable antitoxin activity, and in these the levels were minimal. These findings suggest that pooled serum globulin is not a practical source of exfoliatin antitoxin.

Animals↗
PubMed1976

Antigenic relationships on the diphtheria toxin molecule: antitoxin versus antitoxoid.

We used the mouse to produce antisera to native diphtheria toxin and diphtheria toxoid. With these antisera it was possible to distinguish between toxin and toxoid. By gel diffusion analysis, antitoxin detected antigenic determinants on toxin which were not available on toxoid, indicating that some determinants had been lost or altered by formalin treatment. Antitoxoid, on the other hand, showed reactions of identity between toxin and toxoid in gel diffusion. The toxin neutralization titers measured in tissue culture were the same for both antisera. Only antitoxin neutralized the adenosine 5'-diphosphate ribosyl-transferase activity of fragment A, but suprisingly both antisera had significant anti-fragment A titers when tested by passive hemagglutination. It is suggested that some of the anti-fragment A activity in antitoxin affects the enzyme active site, whereas that in antitoxoid does not, implying the existence of a least two independent antigenic regions on fragment A.

Animals↗
PubMed1975

The effect of co-trimoxazole on antitoxin response to tetanus toxoid.

The effect of a 4-day course of co-trimoxazole (Septrin) on antitoxin response to tetanus vaccine was assessed in a double-blind study involving 22 healthy adults. The tetanus antitoxin levels were measured by in vivo and in vitro methods for up to 8 weeks after the first of two injections of tetanus vaccine, given 4 weeks apart. No sigificant difference was observed in the level of tetanus antitoxin produced in subjects who received co-trimoxazole (Septrin) in recommended therapeutic dosage during the first 4 days of the trial from that in subjects who received placebo tablets. The results indicate that a 4-day course of co-trimoxazole (Septrin) does not affect antibody production.

Animals↗