Search PubMed⌕ Search

Biomedical subjects

D Rowley

Publications and source records attributed to D Rowley.

At least 73 records · Page 4Linked to original sources
PubMed1981

Antibody response to the lipopolysaccharide and protein antigens of Salmonella typhi during typhoid infection. I. Measurement of serum antibodies by radioimmunoassay.

Serum antibody responses to the lipopolysaccharide and protein antigens of S. typhi in typhoid patients were studied using a solid-phase radioimmunoassay technique. Sera from 24 adult typhoid patients and 20 non-typhoid adult controls were compared. As a group, sera from typhoid patients showed increased IgA, IgG and IgM immunoglobulin levels and gave significantly higher anti-LPS and anti-protein antibody titres in all three major immunoglobulin classes than did non-typhoid controls. Levels of antibodies against LPS or protein in sera of typhoid patients were highly variable with a skew distribution. A good correlation was found between antibody titres to the LPS antigen and those to a protein antigen. No correlation, however, was found between the anti-LPS antibody titres measured by radioimmunoassay and the anti-O antibody titres measured by the Widal agglutination test. Titration of anti-LPS or anti-protein antibodies by radioimmunoassay was found to be more sensitive and specific than Widal test for the serological diagnosis of typhoid fever. The advantages of measuring antibody response by radioimmunoassay over conventional Widal test are discussed.

Adult↗
PubMed1981

Antibody response to the lipopolysaccharide and protein antigens of Salmonella typhi during typhoid infection. II. Measurement of intestinal antibodies by radioimmunoassay.

Antibodies to the lipopolysaccharide (LPS) and protein antigens of S. typhi in secretions of small intestine obtained from 12 typhoid patients, four typhoid carriers and 16 non-typhoid control subjects were measured by a solid-phase radioimmunoassay technique. Intestinal secretions obtained from typhoid patients as a group had significantly higher anti-LPS and anti-protein antibodies than those from the control group. These antibodies were both IgM and IgA classes. There was no correlation between the IgM or IgA antibody levels in serum and those in the intestinal secretions. In the intestinal secretions obtained from typhoid carriers, on the other hand, only IgA-class antibodies to the LPS and protein antigens of S. typhi were present at high levels.

Adolescent↗
PubMed1980

Salmonellosis in mice: studies on oral immunization with live avirulent vaccines.

The avirulent Salmonella typhimurium galE strain G30, following oral feeding to mice, developed a state of immunity to a secondary oral challenge with virulent Salmonella typhimurium. This immunity was concommitant with the development of intestinal and serum antibodies and delayed-type hyepersensitivity (DTH) to Salmonella antigens. In contrast, repeated oral doses of a hybrid E. coli vaccine, which expresses the O antigens of Salmonella typhimurium, provided a lesser degree of immunity and, although able to stimulate the formation of serum antibodies, it elicited only a low level of intestinal antibodies and no measurable DTH.

Administration, Oral↗
PubMed1980

Immunologic response in splenectomized and partially splenectomized rats.

One of the following procedures was carried out in 112, 200-gr, Sprague-Dawley rats: (A) sham operation, (B) hemisplenectomy, (C) 90% splenectomy, (D) total splenectomy and autologous spleen transplants in either omental, muscle, or subcutaneous pouch after total splenectomy, and (E) homologous splenic transplants after splenectomy. The rats were challenged intravenously with sheep, cat and guinea pig erythrocytes 6 wk, 3 mo, and 6 mo postoperative. All totally splenectomized rats had significantly reduced primary responses, regardless of whether fragments of splenic tissue had been grafted or not. There was initial lowering of primary response in partially splenectomized animals but they responded significantly better than totally splenectomized rats. After 6 mo the primary response in the hemisplenectomy group was not significantly different from the nonoperated control group. The primary response in the 90% splenectomy group had improved significantly when compared to the total splenectomy group and normal controls. Total splenectomy and partial splenectomy did not appreciably reduce the ability to mount secondary and teritary responses.

Animals↗
PubMed1980

Measurement of intestinal antibody by radioimmunoassay.

The study of antibody responses in the intestine has been greatly hampered by lack of reproducible sensitive assays. An assay for measuring antibody against bacteria capable of regularly detecting gut antibody in gastroenteritis is described. It is based on absorption of antibody onto bacteria and measurement of the amount of antibody bound using radiolabelled anti-immunoglobulin antibody. Anti-light chain antibody is used to detect all classes of antibody as well as partially degraded antibody which retains the capacity to bind; anti-alpha and anti-gamma antibody is used to measure IgA and IgG antibody. The sensitivity of the assay depends on the use of anti-immunoglobulin antibody purified by affinity chromatography and allows measurement of nanogram amounts of antibody. Its specificity and kinetics are described and the particular advantages it provides in the measurement of antibacterial antibody in the intestine are discussed.

Antibodies, Bacterial↗
PubMed1980

The antibody response to bacterial gastroenteritis in serum and secretions.

The antibody responses to bacterial gastroenteritis in jejunal aspirates and sera from sixteen adults and nine children were examined using a radioimmunoassay. Twelve adults served as controls. A clear antibody response was apparent in both intestinal aspirates and sera. While the absolute concentrations of antibody were much higher in sera, the proportion of immunoglobulin committed to specific antibodies was similar in both the intestinal fluids and sera. The antibody responses in the intestine and in the serum were very similar in the group as a whole, but they varied widely in individual subjects. Over a period of 1 month intestinal antibody levels in adults remained constant but in children they showed a decrease. In two subjects high levels of intestinal antibody were still apparent after 1 year. The organism responsible for the infection was still present in the gut of five subjects 1 month after clinical recovery from infection in the presence of local antibody. The relevance of these results and their implications for further study of the immune response to bacterial gastroenteritis are discussed.

Adult↗
PubMed1979

The suppressive effect of circulating specific antibody on the response to oral immunisation with Vibrio cholerae.

Species IgG antibody given intravenously 3-4 hours prior to oral immunisation with Vibrio cholerae led to a specific depression of both the systemic and loca limmune response. One vibriocidal unit of IgG antibody, which itself would given undetectable levels of circulating specific antibody, was significantly immunosuppressive. The suppression is considered to be due to central repression of the antigen-reactive lymphocyte, rather than to antigen exclusion at the gut mucosal surface. The repression appeared less pronounced in some immunoglobulin classes than in others.

Administration, Oral↗
PubMed1979

Clearance of bacteria from lungs of mice after opsonising with IgG or IgA.

The clearance of organisms from the lungs of mice was followed after aerosol administration. Preopsonisation of the organisms with immune serum, as a source of specific antibody, enhanced the rate of pulmonary clearance while s.IgA delayed clearance. In the peritoneal cavity, bacteria pre-treated with immune serum were cleared more rapidly than unopsonised bacteria, but s.IgA had little effect. The presence of Fc receptors for IgG and not s.IgA on alveolar macrophages suggests that, in secretions, IgG is the predominant antibody promoting phagocytosis by alveolar macrophages and that any protective effect of s.IgA is not mediated by these cells.

Animals↗
PubMed1979

Local immune response in mice to Vibrio cholerae.

Cholera immunization schedules were investigated in mice, with emphasis placed on obtaining an immune response in the intestine. The most effective schedule for producing a good local response was found to be several orally-given priming doses of the organism followed after 14 days by an intravenous boosting dose. Major differences between the immune responses in the spleen and the intestine were noted.

Animals↗
PubMed1979

Persistence in the mouse gut as an important factor in oral immunogenicity of strains of V. cholerae.

The immune responses of mice following oral vaccination with two strains of live V. cholerae have been examined. A strain which persisted in the small intestine was a superior local immunogen by comparison with another non-persisting strain. Local persistence and the ability to induce a local immune response appeared to be correlated, since the two vibrio strains elicited identical responses when given parenterally.

Administration, Oral↗
PubMed1979

Intestinal antibody to Vibrio cholerae in immunised mice.

The immune response of the mouse to priming and booster doses of V. cholerae was studied to establish whether serum antibody could be used as a correlate of local immunity. Serum antibody titres following oral boosting of orally-primed animals were shown to reflect the state of local intestinal immunity. This was not the case when the same oral booster dose was given to parenterally-primed animals. These results were discussed in relation to the human endemic situation. The highest titres of intestinal protective antibodies were found following combination of the oral and parenteral routes of immunisation. Various killed or extracted preparations of V. cholerae were used as oral vaccines to test their ability to induce protective antibodies in the gut. Only Boivin antigen was capable of inducing as good an intestinal antibody response as would the living organism.

Administration, Oral↗
PubMed1979

Intestinal and serum antibody responses in mice after oral immunization with Salmonella, Escherichia coli, and Salmonella-Escherichia coli hybrid strains.

After oral feeding of mice with avirulent Salmonella, Escherichia coli, or hybrid strains, only certain bacterial strains were able to multiply and persist within the small intestinal Peyer's patches. After oral vaccination alone, or oral priming and subsequent parenteral boosting, antibody class and titers were detected, using a radioimmunoassay on serum and intestinal fluid or a plaque-forming cell assay on spleens. Only those strains that persisted in the Peyer's patches stimulated the production of serum and intestinal immunoglobulin A antibodies against their respective O antigens. Nonpersistent strains were weakly immunogenic, and antibodies, when present, were largely non-immunoglobulin A and confined to the serum.

Animals↗
PubMed1978

Modifications of the local immune response to Vibrio cholerate attributed to the intestinal microbial flora of the mouse.

Oral immunisation studies in germfree, specific pathogen-free (SPF) and conventionalised mice illustrated that the autochthonous gut flora can have a suppressive effect on the induction of a local intestinal immune response to Vibrio cholerae. Temporary colonisation of the small bowel by viable vibrios occurred only in the germfree animal. The lack of colonisation in SPF and conventionalised mice was presumably a cause of their lower coproantibody responses. Prevention of colonisation was probably due to bacterial antagonism rather than to cross-reaction antibodies. This conclusion was reinforced by studies involving oral immunisation of SPF mice maintained on streptomycin, and of conventionalised ex germfree mice. In addition to the increased protective coporantibody response of animals with reduced gut flora, there were increased levels of non-complement-fixing protective antibodies in their serum, which were probably derived from the guy lamina propria.

Animals↗
PubMed1978

In vitro degradation of mouse, rabbit and dog antibodies to Vibrio cholerae by succus entericus.

Purified antibodies to Vibrio cholerae from mouse, rabbit and dog were digested in vitro by homologous intestinal secretions. When assessed with regard to their complement-dependent vibriocidal activity, IgG antibodies were generally more susceptible to degradation than IgM antibodies, High levels of tryptic inhibitors were required to inhibit this digestion. Rabbit IgG was unusual in being quite resistant to digestion. Gel filtration studies demonstrated that secretory IgA, isolated from mouse intestinal secretions, was resistant to proteolysis. Similar studies on dog IgG and mouse IgM demonstrated production of F(ab') 2-like fragments. Digestss of these antibodies, while devoid of Fc-mediated vibriocidal activity, retained significant protective activity for baby mice.

Animals↗
PubMed1978

The source of IgM and IgG in the dog intestine.

The source of IgM and IgG2a,b in the dog intestine was investigated, using labelled dog immunoglobulins and chronic Thiry-Vella loops of dog small intestine. Clearancess of IgM and IgG2a,b from serum into intestinal secretions were similar, reflecting transfer of a greater mass of IgG2a,b than of IgM. Only 20% of the intestinal IgM derived from serum, irrespective of the marker used. About one third of the total intestinal IgG, of all sub-classes and accrued from all sources, was serum-derived IgG2a,b. This indicates that serum is a major contributor to dog intestinal IgG2a,b.

Animals↗