Development of a Neisseria meningitidis group B serotype 2b protein vaccine and evaluation in a mouse model

Although serotype 2 remains the predominant cause of group B Neisseria meningitidis disease in many parts of the world, most cases of this disease are now due to serotype 2b rather than 2a. For this reason, we adapted the serotype 2a vaccine method of C. E. Frasch and M. S. Peppler (Infect. Immun. 37:271-280, 1982) to the production of a serotype 2b protein vaccine. A spontaneously occurring nonencapsulated mutant of the group B serotype 2b strain 3006 was obtained by selection on group B antiserum agar. Serotype 2b outer membrane protein vaccines were prepared with less than 1% lipoplysaccharide contamination. The immunogenicity of these vaccines was evaluated in mice in the presence and absence of meningococcal group B and group C capsular polysaccharides. The group B and group C polysaccharides equally potentiated the antibody response to the serotype 2b protein. Addition of aluminum hydroxide or aluminum phosphate markedly improved the antibody response to the serotype 2b protein, but aluminum hydroxide-adjuvanted vaccines consistently elicited higher antibody levels. Aluminum hydroxide-adsorbed serotype 2a and 2b protein vaccines were evaluated for induction of cross-protective bactericidal antibodies. The 2a vaccines were 2a specific, whereas the 2b vaccines elicited antibodies strongly bactericidal for both 2a and 2b meningococcal strains and protected against bacteremia in a mouse model. It may therefore be possible to provide protection against both 2a and 2b disease by using an aluminum hydroxide-adsorbed protein vaccine containing a single serotype 2 protein component.

Determination of time course of tablet disintegration II: Method using continuous functions

An analysis of the disintegration-dissolution sequence of drug release from a tablet leads to a mathematical expression relating disintegration to the dissolution profile of the tablet and the dissolution rate of the primary drug particles in the tablet. The equation describing the disintegration of an acetaminophen tablet is determined to demonstrate the application of the theory.

Determination of time course of tablet disintegration I: numerical method

A method is described for determining the time course of tabled disintegration. It involves a numerical analysis of the experimental dissolution profile of a tablet and the dissolution characteristics of the primary drug particles in the tablet. The disintegration profile is determined for an acetaminophen tablet to demonstrate the application of the method. Tablet dissolution is simulated with the disintegration-dissolution model, and the interrelationship between the two fundamental processes is studied theoretically by varying the parameters describing the two processes.

Host preference of mosquito vectors of Japanese encephalitis

The host preference of 4 Culex mosquito species collected in Miaoli and Pingtung counties, Taiwan was studied by capillary precipitin method. Antisera to alum-precipitated sera of man, bovine, swine, rabbit, horse, dog, cat, mouse, chicken, duck, and pigeon were produced in rabbits and reacted with 758 mosquito blood meals among which reactions to one or more antisera. Culex annulus and Culex tritaeniorhynchus summorosus showed a great avidity for pig, and Culex fuscocephala for bovine. Culex pipiens fatigans was ornithophilic. None of 110 C. t. summorosus and 2.4% of 223 C. annulus had fed on man. Among 66 samples of C.p. fatigans tested 10.3% had fed on man, while none of 359 C. fuscocephala did. It seems that the latter does not act as a primary vector of Japanese encephalitis.