PSE UDO.D YSENTERIES 



1861 



mixed in equal parts. The mixed vaccine will therefore contain 200 millions 

 typhoid and 125 millions each of the other oganisras used. Of this vaccine 

 0'5 to 0'6 c.c. is given hypodermicalty the first time, and the same or double 

 the amount after a week. The reaction is somewhat more severe than after 

 inoculation with the triple typhoid para A and para B vaccine. 



In the preparation of the vaccine it is necessary to use a selected strain 

 of Shiga- Kruse, as little virulent as possible. 



Sensitized Vaccine. — An emulsion in normal saline is made from twenty- 

 four hours' old agar cultures. To the suspension is added some undiluted 

 dysentery serum, and after twenty-four hours it is centrifuged and the serum 

 and saline pipetted off. The sediment is washed in normal saline, and then 

 a suspension is made in fresh saline containing i per cent, carbolic, and 

 standardized to contain 100 million bacilli or more; h ex. is injected the first 

 time, and the same or double the dose a week later. 



A sensitized dysentery vaccine was first prepared and used by Broughton 

 Alcock in 1914. It has been used later by other observers, and experiments 

 on it have been carried out recently by Gibson. The reaction is much less 

 severe than using broth vaccines. 



Serum-Vaccine.- — In Japan a vaccine has been given mixed with anti- 

 dysenteric serum, with the object of neutralizing the bacillary endotoxin 

 with the anti-endotoxin present in the serum. The injection of such, serum- 

 vaccine does not give rise to any production of agglutinins, and the doubt 

 has arisen, to which Gibson has called attention, that the antiserum might 

 neutralize all the antigenic properties of the vaccine, besides neutralizing 

 the toxin. 



Gibson's ' Absorbed- Serum Vaccine.'- — ^Gibson mixes the dysentery vaccine 

 with antidysentery serum from which the agglutinins and other antibacterial 

 substances have been removed by means of Castellani's absorption method. 

 Suspensions in normal saline are made from agar cultures of Shiga- Kruse, 

 Flexner, and Y; they are standardized, and then mixed in such proportion 

 that I c.c. of the mixture will contain 2,000 millions Shiga-Kruse, 2,000 millions 

 Flexner, 2,000 millions Y. 



Trivalent antidysentery serum (Shiga-Flexner-Y) is absorbed with Flexner, 

 then with Y, then with Shiga. It is centrifuged and filtered through a 

 Chamberland. The filtered serum is then so diluted that i c.c. of the resulting 

 dilution will contain 0*4 of serum. The diluted serum and the vaccine are 

 filled into twin non-communicating phials, which are joined together. 

 The inoculation is carried out as follows: — ■0*25 c.c. is aspirated in the syringe 

 from each phial and injected subcutaneously in the usual way. The first 

 (\o:,Q contains Shiga 500 millions, Flexner 500 millions. Hiss and Russell 500 

 millions, and o-io absorbed serum. A week later double the amount is 

 given. This absorbed serum- vaccine gives only a very moderate reaction, 

 and seems to induce in the blood of the inoculated persons a satisfactory 

 amount of antibacterial substances as well as antitoxin. 



Dysbackta. — This is a vaccine prepared according to a special method by 

 Boehncke. 



Lipovaccine. — ^A vaccine consisting of an oil emulsion of dysentery bacilli 

 has been prepared according to Le Moignic's method. The reaction is said 

 to be mild. 



C. PSEUDO-DYSENTERIES. 



Definition.-r-Pseudo-dysenteries are diseases other than those 

 defined above, which give rise to diarrhoea, with the passage of blood 

 and mucus in the motions, and are sometimes associated with 

 abdominal pain and tenesmus, and may readily, on superficial 

 examination, be mistaken for true dysentery. 



Remarks.^ — It should, however, be noted that the term ' pseudo- 

 dysentery ' has been used by Kruse to signify a form of bacterial 

 dysentery commonly found among inmates of lunatic asylums, and 



