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Biomedical subjects

C Barber

Publications and source records attributed to C Barber.

At least 19 recordsLinked to original sources
PubMed1979

Complete nucleotide sequence of an influenza virus haemagglutinin gene from cloned DNA.

A synthetic fowl plague virus (FPV) haemagglutinin gene has been cloned in bacteria and the complete sequence of the RNA gene deduced. It is 1,742 nucleotides long and the mRNA codes for 56.3 amino acids in an uninterrupted sequence. The nature of some of the important domains in the haemagglutinin has been established, and their structure is discussed in relation to their function. Extensive amino acid sequence homologies exist between FPV and human influenza haemagglutinins.

Amino Acid Sequence↗
PubMed1979

Salmonella choleraesuis proteins and their relation to proteins from bacteria of heterologous sero-groups.

A diversity of proteins was identified in the material isolated from S. choleraesuis with the help of sera prepared in rabbits with this material. The sera displayed, in agar-gel diffusions, numerous superimposed precipitation lines against proteins from: Salmonellae, Shigellae and E. coli. In contrast to proteins from S. paratyphi C, sharing identical identical 'O' 'factors, the serological activity of the S. choleraesuis proteins was impaired by heating. The immunochemical analysis of the sera before and after exhaustive absorptions with heterologous proteins exhibited a stronger relation of S. choleraesuis with S. thyphimiurium and S. Newport than with S. paratyphi C. The antibodies induced against free proteins with S. paratyphi C specificity, present in the mosaic of proteins isolated from S. choleraesuis, were removed by the respective absorption without substantial modifications of the homologous precipitation. In contrast, the absorption of the serum with proteins from either S. newport or S. typhimurium removed almost all the homologous induced antibodies. The strong relations found among species belonging to different serogroups underline the non-conformity of the empirical established serofactors.

Animals↗
PubMed1979

Discrepancies Between strong immunochemical relations of S. typhimurium and S. kentucky and their behaviour "in vivo".

Proteins from S. typhimurium and from S. kentucky strongly cross-precipitated against sera prepared in rabbits with the respective strains; agglutinations paralleled the precipitations. The related antigens were, however, not involved in "in vivo" cross-protections. Mice immunized with proteins from S. kentucky resisted the toxicity of the homologous strain and that of a concentration of S. emek which killed the controls but did not survive the infection with 1LD100 of S. typhimurium. There was a long delay in the death of those mice infected with S. typhimurium while the mice immunized with S. typhimurium proteins were killed by the toxicity of 1LD100 S. kentucky, like the controls, within 20 hours. The results strikingly underline the specificity of host-parasite relations and the need for circumspection when involving common antigens in either virulence or toxicity.

Animals↗
PubMed1979

The numerous common antigens of enterobacteriaceae.

A mosaic of proteins is synthesized by each of the Enterobacterial species grown on artificial media (tryptose-agar, Difco). Their existence was proven with the help of sera prepared in rabbits with proteins from: S. enteritidis, S. typhi, S. typhimurium, S. paratyphi C, E. coli, and Sh. sonnei. The induced antibodies, strongly precipitated numerous heterologous Enterobacterial proteins. The proteins of Sh. dysenteriae 4, although reacting against the heterologous sera, were poor immunogens and induced, mainly, homologous antibodies. Comparative agar-gel diffusions of the same proteins against the antiproteinic sera and corresponding antibacterial sera proved that the bacteria induced fewer antibodies against a reduced number of heterologous antigens. Thus, it is evident that a competition among the numerous antigens of a bacterium takes place when whole bacteria are used for immunizations. The differences in the degree of relatedness of Salmonellae, Shigellae, and E. coli are illustrated by their reactions in agar-gel against homologous and heterologous sera. The serological activity of heated proteins (1 hr at 100 degrees C) against the antiproteinic sera differed according to the intrinsic qualities of the analysed materials.

Animals↗
PubMed1978

Conformational studies on wheat embryo 5S RNA using nuclease S1 as a probe.

Ribosomal 5S 32 P-labelled RNA was isolated from imbibing wheat embryos and digested with nuclease S1, a single-strand specific nuclease. The products of enzymic digestion were separated by polyacrylamide gel electrophoresis and identified by fingerprint analysis of their RNase T1 digestion products. The results indicate that the most sensitive portion of the molecule, and hence, the region containing the least helical structure, is close to the 5'-terminus. Similarly, the most resistant portion of the molecule is close to, but does not include, the 3'-terminus. These findings are discussed in relation to proposed models for the secondary structure of 5S RNA.

Base Sequence↗
PubMed1978

Immunological relations of proteins from four salmonellae sharing an "O" factor 8.

The proteins from S. virginia, with the sole 8 "O" factor, precipitated against homologous and related heterologous sera by a conspicuous, homogenous line of serological identity, with proteins from: S. newport (6.8), S. blockley (6.8), S. emek (8.20). The proteins, however, were not involved in the bacterial agglutinations since the absorptions, which removed the common precipitins from the sera, did not modify the homologous agglutinations. The results with anti-S. newport and anti-S. blockley sera sharing identical "O" factors while displaying different immunochemical compositions as well as the strong immunochemical relations found between S. virginia and S. newport belonging to the different subgroups C2 and C3 underline the non-relatedness of agglutinins and precipitins.

Agglutination Tests↗
PubMed1978

Immunochemistry of S. kentucky (8.20); its relations with S. emek (8.20), S. virginia (8) and S. newport (6.8).

Immunochemical studies of S. kentucky showed that the strain has an identical polysaccharide with S. emek with which it shares the same "O" factors 8.20, and a common proteinic carrier of the polysaccharide. Absorptions of anti-S. kentucky sera with proteins from S. virginia ("O" factor 8) did not influence the homologous precipitations or agglutinations, nor the cross-reactions with S. emek. In contrast, the absorptions of the anti-S. Kentucky sera with proteins from S. newport (6.8) caused a conspicuous modification in the precipitations of S. emek proteins against the absorbed serum; this coincided with a drastic fall in the agglutinating titer for the heterologous S. emek strain while the homologous agglutination was unchanged. The results underlined the role of the specific proteins as agglutinogens and, in addition, sustain Kauffmann's recommendation for the preparation of the, empirically established, monofactor serum 20.

Agglutination↗
PubMed1978

Behaviour of S. paratyphi A in mice immunized with homologous and heterologous bacterial proteins.

Mice immunized with proteins from S. typhimurium and from S. paratyphi C resisted the toxicity of a concentration of S. paratyphi A which killed the controls; this is in contrast to the results found in mice immunized with the same amount of proteins from the homologous S. paratyphi A. For the neutralization of the S. paratyphi A toxicity a higher quantity of homologous proteins was necessary in the immunizations. It is assumed that either S. paratyphi A synthesizes--on artificial media--a small amount of proteins responsible for the induction of neutralizing antibodies or that it is an intrinsic weak immunogen. In the sera of mice in which sufficient neutralizing antibodies were induced, the proteins of S. paratyphi A cross-reacted in agar-gel, with the proteins from S. typhimurium and from S. paratyphi C.

Animals↗
PubMed1977

Production of precipitating antibodies in chickens infected with Salmonella gallinarum.

Vaccination of 10 days old chicken with a live relatively avirulent S. gallinarum induced antibodies against the main antigens of the pathogen, namely, its proteins. Precipitations in agar gel were obtained against the free proteins and the protein conjugated in the somatic antigen of S. gallinarum and against antigens from the related S. enteritidis. Antipolysaccharide antibodies were induced in small quantities which were however sufficient to allow their identification with the agar-gel-diffusion technique.

Animals↗
PubMed1977

Immunochemical relations of salmonella paratyphi C with the salmonellae of group B.

Agar-gel precipitations of proteins from S. paratyphi C, S. paratyphi B and S. typhimurium against homologous and heterologous antibacterial sera, prepared in rabbits, demonstrated a strong relatedness between these species belonging to different serogroups. The findings explain and substantiate previous experiments in which high cross-protections were obtained in groups of mice immunized with proteins from these species and subsequently infected with S. typhimurium or its "in vivo" related S. paratyphi B and S. paratyphi C.

Agglutination↗
PubMed1977

Serological specificities of polysaccharides from four Salmonellae sharing "O" factor 8.

S. virginia (8) and S. newport (6.8) induced in sera of hyper-immunized rabbits antibodies which precipitated the respective homologous and heterologous polysaccharides as well as the polysaccharides from S. blockley (6.8) and from S. emek (8.20) by homogeneous lines of, apparent, serological identity. S. blockley, sharing with S. newport the same "O" factors, induced however two antipolysaccharides of which only one was identical with that of S. virginia. Different proteinic carriers were found to be responsible for the two induced antipolysaccharides. S. emek (820) induced antipolysaccharide antibodies which displayed a reaction of partial identity with the heterologous polysaccharides, in contrast to the serological homogeneity of precipitation, shown by the S. emek polysaccharide against the heterologous sera. The existence of a more complex structure of the S. emek polysaccharide, of which a small determinant is in common with the heterologous polysaccharides and is associated with a common proteinic carrier explains these different reactions.

Animals↗
PubMed1977

Salmonella gallinarum - Salmonella enteritidis relationship in rabbits.

The polysaccharide of S. gallinarum, sharing factors 9.12 with the Salmonellae of group D. cross-reacts with one of two serological determinants, present in the polysaccharide of S. enteritidis, and is different from the determinant responsible for the cross-reaction of S. enteritidis and S. typhy polysaccharides. The absorption of anti S. gallinarum sera with proteins from S. enteritidis removed all the antibodies induced for the homologous antigens; in contrast, the absorption of the anti S. enteritidis sera with proteins from S. gallinarum removed all the antigens common to S. gallinarum and S. enteritidis, leaving for reaction the antibodies induced to specific antigens of S. enteritidis.

Animals↗
PubMed1977

Neutralization of heterologous toxicities in mice immunized with proteins from S. typhimurium and from a human pathogen (S. emek).

Groups of mice immunized with proteins from S. typhimurium and from a non-pathogenic Salmonella for mice (S. emek) were infected with S. tymphimurium, S. emek, S. blockley and S. paratyphi A. The mice immunized with the S. typhimurium proteins were, as always protected against infection with the pathogen and resisted the toxicities, which killed the controls, of S. paratyphi A and S. emek but not of S. blockley. The mice immunized with S. emek proteins resisted the toxicity of S. paratyphi A and, to a lesser degree, that of the homologous S. emek. The animals did not resist the toxicity of a similar concentration of S. blockley and the immunized mice died, like the controls, within 20-40 hours. Mice in this group infected with S. typhimurium had a much longer delay before dying, than the controls. Antiprotein antibodies present in the sera of the immunized mice are, apparently, responsible for the neutralization of the toxicities of the heterologous strains and for the eventual protection against infection.

Animals↗
PubMed1977

Immunochemistry of Yersinia enterocolitica O3 grown at different temperatures.

Comparative agglutinations of homogeneous stable suspensions prepared with Yersinia enterocolitica growth at 37 degrees C and at 25 degrees C were performed with anti-sera prepared in rabbits with the bacteria grown at both these temperatures. Sera prepared with live Y. enterocolitica grown at 37 degrees C agglutinated both suspensions at a much lower titre than the sera prepared with formaldehyde-treated bacteria is grown at 25 degrees C. All the sera in which strongly precipitating antibodies were induced reacted, in agar-gel, against native and heated proteins. The small amounts of antipolysaccharides induced in all the sera reacted only in the ring test against the bacterial polysaccharides. The absorption of the sera prepared with live Y. enterocolitica grown at 37 degrees C, with antigens synthesized at 25 degrees C did not remove all the homologous antibodies; apparently, some determinants are specific for the bacteria grown at 37 degrees C. Morphological changes of the small rods to elongated bacilli and filamentous forms were observed in most cultures of the Y. enterocolitica grown at 37 degrees C; these changes coincided with a low yield of proteins and point to an inhibitory effect of the 37 degrees C temperature.

Agglutination Tests↗
PubMed1977

Behaviour of Salmonellae non-pathogenic for mice. I. Neutralization of their toxicities by induced antiprotein antibodies.

Groups of mice hyperimmunized with proteins from Salmonella strains which are not pathogens for mice (S. typhi o901, S. typhi Ty2, S. blockley, S. newport) resisted inoculation with concentrations of homologous and related heterologous liver bacteria, which killed all the controls in 20-48 hrs. The toxicity of the Salmonella tested was about 100-1000 times lower than that of the pathogenic S. typhimurium and concentrations of 10(8) or 10(9) bacteria (according to the strains used) were necessary to kill all the controls. In contrast to the period of incubation (2-12 days) required for S. typhimurium to kill all the controls and eventually some of the immunized mice, too, the killing with the human pathogenic Salmonella took place within 20-48 hrs. The toxicity of the big concentrations of bacteria needed to kill the controls was apparently neutralized by the antiprotein antibodies induced in the immunized mice. In no group of mice resisting inoculations with 1 x 10(8) or 1 x 10(9) of the homologous or heterologous tested Salmonellae protection could be obtained against infection with 1LD100 (1 x 10(6) of S. typhimurium. These results underline the specificity of host-parasite relations in infection and minimize the role attributed to the cellular mechanism, which is insufficient for protection against an infection if the pathogen tested is not specific for the host in experiment. In contrast to events in mice protected against the infection with S. typhimurium, and its related "in vivo", S. paratyphi B and S. paratyphi C, the antibodies initially present in the sera of the mice immunized with proteins from the human pathogens were no longer found 25 days after the infections. Reinfections of some of the groups of the surviving mice did not result in protections.

Animals↗
PubMed1976

Cross-protection induced in mice by immunizations with proteins of related bacteria species.

Groups of mice were immunized with detoxified protein from S. typhimurium, S. paratyphi B and S. paratyphi C. Consecutive infections with different concentrations of the homologous and heterologous strains showed that: 1. Immunizations with proteins from S. typhimurium induced protections in 65% of the mice infected with 50 LD100 of their natural pathogen, and in 80% of the mice infected with 50 LD100 of S. paratyphi B; the infection with S. paratyphi C of mice in this group afforded protection against 20 LD100 in 75% of the animals. 2. Immunization with proteins from S. paratyphi B induced protection in the mice against the infection with 20 LD100 of S. typhimurium (survival of 80% of the mice) and against 20 LD100 of the homologous S. paratyphi B (survival of 90% of the mice). 3. Immunization with proteins from S. paratyphi C protected the mice against the infection with 20 LD100 of S. typhimurium in a proportion of 80-85% of the animals; infection with the homologous S. paratyphi C did not result in protection against more than 20 LD100 of the bacteria (80-85% survivals). The survivors, in each group, when reinfected 30 days later with 50 LD100 of S. typhimurium resisted in a proportion of 100%, as a consequence of antibodies induced against more specific proteins released in the mice during the infections by the related pathogens.

Animals↗
PubMed1976

The unfortunate role of precedent in bacteriology. I. The main antigens of salmonellae: the proteins.

Proteins from S. paratyphi B were found to be better immunogens, in rabbits, than the bacteria from which they were extracted. Likewise, proteins from S. newport induced antibodies which reacted in agar gel, against proteins from many species of Salmonella. The immunogenicity of the bacterial proteins, as well as their many biological activities are ignored because the classic techniques used lose these main antigens of Enterobacteriaceae. The contrasting overemphasized role attributed to the lipopolysaccharides has created a precedent which is not to the advantage of bacteriology.

Animals↗