Antigenic Value of Botulinum Toxoids Kept one Year at Ice Box Temperature
| Autor: | Robert Graham, Frank Thorp |
|---|---|
| Rok vydání: | 1931 |
| Předmět: | |
| Zdroj: | The Journal of Immunology. 20:305-312 |
| ISSN: | 1550-6606 0022-1767 |
| DOI: | 10.4049/jimmunol.20.4.305 |
| Popis: | Summary An antigenic decline in botulinum toxoids of 30 to 60 per cent over a period of one to twelve months was measured by the increased number of arbitrary units required to protect guinea pigs against lethal amounts of homologous toxins. None of the eleven toxoids that proved non-toxic in 1-unit doses later became toxic in the same amounts, notwithstanding an occasional toxoid inoculated pig died of intercurrent infection. Seven of eleven samples of botulinum toxins A, B, and C containing 0.3 to 0.9 per cent formalin became detoxified at 37° to 42°C. in one month. The remaining four of eleven samples required two to five months for detoxification. One sample (3826 A) retained its original antigenic properties for five months, another (3217 B) for three months, three for two months, and two for one month. Ten of the eleven toxoids were atoxic and antigenic in 2-unit doses at ten to twelve months of age. The rate of detoxification in botulinum toxoids by formalin and heat seemed uncorrelated with the longevity of the antigenic properties. One toxin with 20,000 guinea pig lethal doses per cubic centimeter required a longer period of time for detoxification than other toxins containing 10,000 guinea pig lethal doses per cubic centimeter. However no consistent difference in the rate of antigenic decline was observed between toxoids prepared from toxins containing 10,000 and 20,000 guinea pig lethal doses per cubic centimeter. The pH of eleven botulinum toxoids changed from an original titer of pH 7.6 in the inoculated mediums to an average of pH 6.7 in seven and one-half months. |
| Databáze: | OpenAIRE |
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