Determination of the Vi-antigen content of acetone-dried typhoid vaccines

1956 ◽  
Vol 22 (1) ◽  
pp. 24-32
Author(s):  
H. H. Cohen ◽  
H. A. Engel
Keyword(s):  
Typhoid Vaccines ◽  
Vi Antigen

scholarly journals DETERMINATION OF DIFFERENCES IN VIRULENCE OF STRAINS OF SALMONELLA TYPHOSA

1950 ◽  
Vol 91 (2) ◽  
pp. 219-229 ◽  
Author(s):  
H. C. Batson ◽  
Maurice Landy ◽  
Martha Brown
Keyword(s):  
Intraperitoneal Injection ◽  
Biological Characteristics ◽  
Intracerebral Injection ◽  
Test Organisms ◽  
Vi Antigen

An investigation is reported of a comparison by three methods of the degree and certainty of differentiation of strains of S. typhosa of different virulence for mice. These methods were (a) intracerebral injection, (b) intraperitoneal injection of saline suspensions, and (c) intraperitoneal injection of mucin suspensions of the test organisms. With the strains of S. typhosa employed, differentiation was questionable by the intracerebral method, somewhat more marked by the intraperitoneal-saline suspension method, and most definite by the intraperitoneal-mucin suspension method. Differentiation of the strains employed was found to be independent of the presence or absence of Vi antigen and apparently was more dependent upon the method of testing than upon any known differences in biological characteristics of the organisms.

scholarly journals STUDIES ON INFECTION AND IMMUNITY IN EXPERIMENTAL TYPHOID FEVER

1961 ◽  
Vol 114 (3) ◽  
pp. 327-342 ◽  
Author(s):  
Sidney Gaines ◽  
Maurice Landy ◽  
Geoffrey Edsall ◽  
Adrian D. Mandel ◽  
R.-J. Trapani ◽  
...  
Keyword(s):  
Typhoid Fever ◽  
O Antigen ◽  
Typhoid Vaccines ◽  
Vi Antigen

A study was made of the efficacy of various antityphoid immunizing agents in immunizing chimpanzees against typhoid fever produced by feeding viable S. typhosa. It was found that both acetone-killed and heat-killed, phenol-preserved typhoid vaccines were effective in protecting against infection induced with either homologous or heterologous strains of typhoid bacilli. Purified O antigen induced no discernible protection, but some immunity was afforded by the administration of purified Vi antigen.

scholarly journals The preparation, testing and standardization of typhoid vaccine

1951 ◽  
Vol 49 (2-3) ◽  
pp. 268-287 ◽  
Author(s):  
A. Felix
Keyword(s):  
Typhoid Vaccine ◽  
Systemic Reactions ◽  
Active Immunity ◽  
Official Control ◽  
Test Culture ◽  
Analogous Manner ◽  
Additional Support ◽  
Typhoid Vaccines ◽  
Source Of Error ◽  
Vi Antigen

1. The review of the laboratory evidence published since the introduction, ten years ago, of the alcohol-treated typhoid vaccine furnishes additional support for abandoning the old method of making typhoid vaccine. The alcohol-treated vaccine has advantages in regard to both the Vi-antibody response and the degree of systemic reactions produced.2. The technique of the preparation of alcohol-killed and alcohol-preserved typhoid-paratyphoid vaccine has remained as originally described. The methods of selecting the vaccine strains and routinely examining the cultures have also remained unchanged.3. The necessity of testing typhoid vaccines not only by active-immunity tests in mice but also for their antibody-stimulating properties is again stresssed. These tests consist of immunization of rabbits, estimation of their Vi- and O-agglutinin titres and passive-immunity tests in mice.4. The most important sources of error in mouse-protection tests are:(a) the use of a test culture of less than the maximum degree of mouse-virulence;(b) the use of the mucin technique;(c) immunization by intraperitoneal injections when the challenge dose also is given by this route.Much of the experimental work on typhoid vaccine has been invalidated by these three pitfalls.5. It is suggested that the mucin technique be abandoned in the assay of typhoid vaccine.6. A source of error in the rabbit test is the presence of pre-formed Vi agglutinins. These are found in rabbits harbouring coliform organisms which possess the typhoid Vi antigen. Such rabbits do not respond to injections of typhoid Viantigen.7. Standardization of the potency of typhoid vaccine has now become possible. Either an alcohol-preserved or a dried vaccine can serve as ‘standard vaccine’, to be used in combination with the ‘Provisional Standard Anti-typhoid Serum’. Both of these vaccines remain stable for a number of years.8. Suggestions are briefly outlined for:(a) the routine examination in the course of preparation of the vaccine;(b) the official control of the potency of typhoid vaccine.9.The paratyphoid components of T.A.B.C. vaccine can be standardized in an analogous manner.

Adhesion of Vi Antigen and Toxicity in Typhoid Vaccines Inactivated by Acetone or by Heat and Phenol

1974 ◽  
Vol 129 (5) ◽  
pp. 501-506 ◽  
Author(s):  
K. H. Wong ◽  
J. C. Feeley ◽  
M. Pittman ◽  
M. E. Forlines
Keyword(s):  
Typhoid Vaccines ◽  
Vi Antigen

scholarly journals Chrome typhoid vaccine

1963 ◽  
Vol 61 (1) ◽  
pp. 43-51
Author(s):  
E. E. Vella
Keyword(s):  
Endemic Area ◽  
Laboratory Animals ◽  
Typhoid Vaccine ◽  
Japanese Workers ◽  
Scale Field ◽  
The Stability ◽  
Typhoid Vaccines ◽  
Vi Antigen

1. Experimental typhoid vaccines, treated by 1% formalin and 0·02% chrome alum (KCr(SO4)2.12H2O), as suggested by Japanese workers were prepared and tested by the usual in vitro and in vivo tests.2. Agglutination tests, antibody production in rabbits, active and passive mouse protection tests confirm the stability of the Vi antigen of the vaccine, if properly stored, and the good protection afforded to laboratory animals in both the active and passive mouse protection tests.3. It is suggested that only a full-scale field trial in a typhoid endemic area can give the answer as to the real efficacy and/or superiority of the chrome vaccine over other typhoid vaccines.

Galactic orbits of stars

1966 ◽  
Vol 25 ◽  
pp. 93-97
Author(s):  
Richard Woolley
Keyword(s):  
Globular Cluster ◽  
Potential Field ◽  
High Velocity ◽  
Velocity Vector ◽  
Variable Stars ◽  
The Sun ◽  
Proper Motions ◽  
Rr Lyrae ◽  
The Galaxy

It is now possible to determine proper motions of high-velocity objects in such a way as to obtain with some accuracy the velocity vector relevant to the Sun. If a potential field of the Galaxy is assumed, one can compute an actual orbit. A determination of the velocity of the globular clusterωCentauri has recently been completed at Greenwich, and it is found that the orbit is strongly retrograde in the Galaxy. Similar calculations may be made, though with less certainty, in the case of RR Lyrae variable stars.

Distance to SN 1987A and the LMC

1999 ◽  
Vol 190 ◽  
pp. 549-554
Author(s):  
Nino Panagia
Keyword(s):  
Angular Size ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Light Curves ◽  
Distance Modulus ◽  
Absolute Size ◽  
Sn 1987A

Using the new reductions of the IUE light curves by Sonneborn et al. (1997) and an extensive set of HST images of SN 1987A we have repeated and improved Panagia et al. (1991) analysis to obtain a better determination of the distance to the supernova. In this way we have derived an absolute size of the ringRabs= (6.23 ± 0.08) x 1017cm and an angular sizeR″ = 808 ± 17 mas, which give a distance to the supernovad(SN1987A) = 51.4 ± 1.2 kpc and a distance modulusm–M(SN1987A) = 18.55 ± 0.05. Allowing for a displacement of SN 1987A position relative to the LMC center, the distance to the barycenter of the Large Magellanic Cloud is also estimated to bed(LMC) = 52.0±1.3 kpc, which corresponds to a distance modulus ofm–M(LMC) = 18.58±0.05.

International determination of the total motion of the pole

1961 ◽  
Vol 13 ◽  
pp. 29-41
Author(s):  
Wm. Markowitz
Keyword(s):  
Secular Motion ◽  
The Future

A symposium on the future of the International Latitude Service (I. L. S.) is to be held in Helsinki in July 1960. My report for the symposium consists of two parts. Part I, denoded (Mk I) was published [1] earlier in 1960 under the title “Latitude and Longitude, and the Secular Motion of the Pole”. Part II is the present paper, denoded (Mk II).

Time and Latitude in South Africa

1972 ◽  
Vol 1 ◽  
pp. 27-38
Author(s):  
J. Hers
Keyword(s):  
South Africa ◽  
Cape Town ◽  
Astronomical Observations ◽  
Royal Observatory ◽  
The Republic ◽  
Astronomical Determination ◽  
Limited Accuracy ◽  
Better Than

In South Africa the modern outlook towards time may be said to have started in 1948. Both the two major observatories, The Royal Observatory in Cape Town and the Union Observatory (now known as the Republic Observatory) in Johannesburg had, of course, been involved in the astronomical determination of time almost from their inception, and the Johannesburg Observatory has been responsible for the official time of South Africa since 1908. However the pendulum clocks then in use could not be relied on to provide an accuracy better than about 1/10 second, which was of the same order as that of the astronomical observations. It is doubtful if much use was made of even this limited accuracy outside the two observatories, and although there may – occasionally have been a demand for more accurate time, it was certainly not voiced.

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