PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-7 (7)
 

Clipboard (0)
None

Select a Filter Below

Journals
Authors
more »
Year of Publication
Document Types
1.  Studies on the growth and survival of Staphylococcus aureus in corned beef. 
The Journal of Hygiene  1983;91(3):467-478.
The growth of an enterotoxin A producing strain of Staphylococcus aureus in corned beef was investigated. In the inoculated 6 lb. canned product the bacteria spread throughout the meat and attained high numbers. The rate of spread of the organisms was related to the temperature and length of storage of the cans and the numbers of bacteria inoculated. Cans which had been stored for more than four months showed high counts of the bacteria throughout the meat. It was noted that with the long term contaminated product counts of S. aureus on some selective media may give falsely low results. Numbers of S. aureus on meat inoculated by handling after removal from the can were initially extremely variable. More uniform distribution and higher counts were attained only if the meat was exposed for some hours at ambient temperature or above. The significance of the results to the investigation of outbreaks of food poisoning suspected of being associated with canned corned beef is discussed.
PMCID: PMC2129339  PMID: 6663062
2.  Trypanosome variant surface glycoproteins are recognized by self-reactive antibodies in uninfected hosts. 
Infection and Immunity  1996;64(11):4593-4597.
The variant surface glycoproteins (VSGs) of African trypanosomes form a dense surface coat on the bloodstream parasites. VSGs are immunodominant antigens that stimulate a rapid antibody response in trypanosome-infected individuals. In the present study, we examined VSG-specific antibodies present not only in sera from infected individuals but also in sera from individuals that had never been exposed to trypanosomes. Native antibodies against different VSGs were detected in sera from uninfected mice, bovines, and humans; the antibodies were revealed to be exclusively directed against variable determinants of the antigens. Further experimentation demonstrated that such native antibodies immunoreact with cellular components of mice and thus are most likely produced by the self-reactive B-cell compartment of the murine immune system.
PMCID: PMC174418  PMID: 8890212
3.  Cell Wall Protein in Bacillus subtilis 
Journal of Bacteriology  1977;129(1):547-549.
The cell wall of Bacillus subtilis 168 contains protein that is refractory to removal by salts, detergents, and denaturants.
PMCID: PMC234958  PMID: 401503
5.  T-cell-independent and T-cell-dependent B-cell responses to exposed variant surface glycoprotein epitopes in trypanosome-infected mice. 
Infection and Immunity  1990;58(7):2337-2342.
The T-cell dependency of B-cell responses to variant surface glycoprotein (VSG) epitopes exposed in their native surface conformation on Trypanosoma brucei rhodesiense clone LouTat 1 was investigated. T-cell requirements were examined by analyses of gamma globulin preparations derived from trypanosome-infected BALB/c nude (nu/nu) and thymus-intact (nu/+) mice. A radioimmunoassay was used to selectively quantitate antibody binding to native VSG 1 epitopes present on the surface of viable trypanosomes. Such analyses of VSG-specific antibody in infected mice demonstrated that in the absence of T cells there was a significant B-cell response to exposed VSG epitopes; however, in the presence of T cells these surface epitope-specific responses were greatly enhanced. In contrast to infection, immunization of mice with purified VSG 1 or paraformaldehyde-fixed parasites elicited significant VSG surface epitope-specific responses only in the presence of T cells (i.e., in nu/+ mice only). VSG-specific antibody responses in mice infected with three other clonal T. brucei rhodesiense populations (LouTat 1.2, 1.5, and 1.9) were found to be similar in this pattern, although not identical, to the anti-LouTat 1 responses. An important exception was that mice infected with LouTat 1.8 required T cells to produce VSG surface-specific antibody. Thus, the VSG surface epitope-specific B-cell responses in trypanosome-infected mice represent composite T-cell-independent and T-cell-dependent processes, and a significantly stronger response is made in the presence of T cells. However, immunization with VSG in the absence of infection elicited only T-cell-dependent responses. Since the relative contribution of T-cell-independent and T-cell-dependent processes to the total VSG-specific antibody produced during infection was variable (as seen with the absence of a T-cell-independent response to LouTat 1.8), this may reflect differences in the primary structure or display of VSG molecules on the trypanosome membrane or may represent active parasite interference with some epitope-specific B-cell responses.
PMCID: PMC258817  PMID: 1694824
6.  Genetics of resistance to African trypanosomes: role of the H-2 locus in determining resistance to infection with Trypanosoma rhodesiense. 
Infection and Immunity  1981;34(2):513-518.
Susceptibility and resistance to Trypanosoma rhodesiense infections in inbred and H-2 congenic strains of mice were studied. Mean survival times and patterns of parasitemia were examined. C3HeB/FeJ mice were highly susceptible; CBA/J, A/J, and BALB/cByJ mice displayed an intermediate level of susceptibility; whereas C57BL/10 mice were highly resistant. H-2 congenic strains with the BL/10 background resembled the BL/10 parental type, thereby suggesting that the major histocompatibility complex does not play a major role in regulating resistance and susceptibility to infection with T. rhodesiense.
PMCID: PMC350897  PMID: 7309237
7.  Lymphocyte function in experimental african trypanosomiasis: mitogenic effects of trypanosome extracts in vitro. 
Infection and Immunity  1976;14(4):976-981.
Extracts of Trypanosoma brucei and Trypanosoma congolense were incubated in vitro with nonimmune lymphocytes of mice, rats, guinea pigs, and rabbits in order to test for mitogenic effects or for other characteristics of polyclonal B lymphocyte activators. Trypanosome extracts (TE) were not mitogenic for spleen cells of mice, rats, and guinea pigs in vitro, nor did the parasite extracts alter the mitogenic responses of lymphocytes from these animals to known B- and T-cell mitogens. TE also failed to induce polyclonal antibody synthesis in mouse spleen cell cultures in an in vitro antibody response system, in contrast to the effects of bacterial lipopolysaccharide, a known polyclonal B cell activator. Rabbit spleen cell and peripheral blood lymphocyte cultures, however, were stimulated by TE to undergo blastogenesis in vitro. Incubation of rabbit lymphocytes with phytohemagglutinin (PHA) and TE or anti-rabbit immunoglobulin serum and TE revealed an additive effect only in terms of the TE-plus-PHA culture responses; these findings suggest that a non-PHA responsive lymphocyte population, possibly B lymphocytes, is stimulated by TE in rabbits. The relationship of trypanosome-induced lymphocyte mitogenic stimulation to other immunological dysfunctions occurring in chronic African trypanosomiasis is discussed.
PMCID: PMC415481  PMID: 992878

Results 1-7 (7)