Biomedical subjects
Publications and source records attributed to J L Sloyer.
A rapid (10 s) automated fluorescent method to estimate viable bacteria in metal working fluids (MWF) was compared with dip-slide cultures. The BactiFluor method compared favorably with 107 MWF (r=0.99) and with 30 other metal processing fluids.
The electrophoretic mobility (EPM) of selected macromolecules in solution was shown to be accurately determined using an automated electrokinetic analyzer, the PenKem S3000. In addition, the S3000 was used to monitor the effects of T4 phage infection on the EPM of Escherichia coli B. EPM, expressed as the ratio of velocity in microns/sec to field strength in V/cm, was measured for calf thymus DNA, for pneumococcal capsular polysaccharide serotype 3 (PCP-3), and for bovine serum albumin (BSA) unbound in solution; values of -3.05, -2.736 and -1.176, respectively, were obtained. The EPM of these macromolecules remained the same when they were bound to latex beads. The S3000 may therefore be suitable for measurement of the EPM of unbound macromolecules. The EPM of T4 phage in solution was measured to be -1.203. However, both the zwitterionic latex-bound T4 phage as well as T4 phage disrupted by ultrasonication exhibited an EPM of approximately -2.50, suggesting to us that binding to zwitterionic latex may cause release of phage DNA. The notion that phage DNA is responsible for the increased negative charge was supported by the observation that the EPM of E. coli B increased to the level of free DNA within 5 min when E. coli B (the host cell for phage T4) had been exposed to 10 phage particles per cell. Electronmicrographs of phage infected E. coli B cells showed numerous strands of free DNA at the bacterial surface. It is concluded that the S3000 not only measures the EPM of macromolecules in solution but that the instrument can be used also to monitor the behavior of the host cell surface in response to attachment of viral particles.
The electrophoretic mobility (EPM) of a variety of Gram-negative and Gram-positive bacteria was measured with a Penkem S3000 analyser. Under standard growth conditions and neutral pH all cells displayed a negative EPM. The polysaccharide capsules of Escherichia coli strains K1, K5, K29 and K30 generated the highest EPM; to a lesser and varying degree O-antigens with charged groups and core lipopolysaccharides also contribute to the net EPM. Very little negative EPM was measured in suspension cultures of the gliding bacterium Cytophaga U67. No difference in the EPM was observed between rapidly growing and stationary-phase E. coli B. De-energization of the cell membranes by carbonyl cyanide m-chlorophenylhydrazone (CCCP) did not affect the EPM of wild-type and deep rough mutants of E. coli; and the EPM of Cytophaga U67 and Acholeplasma laidlawii remained unaltered by CCCP when measured in their respective growth media. Extrusion of filamentous bacteriophage f1 from cells of its host, E. coli A95, caused a shift to a higher negative EPM. We also measured a variety of Gram-positive strains, all of which displayed different EPMs. When membrane fractions of E. coli were adsorbed to latex spheres, characteristic differences between the EPM of beads coated with either inner or outer membrane were observed. The results suggest that the rapid EPM analysis is a useful tool to study the net electric charge of microorganisms and to examine changes of surface properties during interaction of cells with viruses, proteins (antibody) and charged antibiotics.
A total of 133 children between 6 and 11 months of age with at least one episode of otitis media were given one of two pneumococcal vaccines. One vaccine contained 25 microns of types 1, 3, 6, 7, 14, 18, 19, and 23 and the other vaccine (control) contained 25 microns of types 2, 4, 5, 8, 9, 12, and 25. Follow-up care of the 65 black infants revealed significantly more otitis media visits in those infants receiving the control vaccine. Among the 68 white infants there was no difference between control and vaccine groups after vaccination.
Explore the source record for details and available documents.
With the technique of radioimmunodiffusion and indirect FA staining, IgA antibody to measles, mumps, rubella, and polio-1 were determined in serum and middle ear fluid (MEF) of 103 patients with otitis media. The occurrence of IgA viral antibody in MEF and its absence in simultaneously drawn serum was used as an indicator of local antibody production. Of the 401 assays performed, 41 instances of IgA antibody exclusively in MEF were found. Only four of these occurred in specimens from unimmunized patients and were directed against rubella virus. Of the 37 remaining cases, 16 each were directed against measles and polio-1 and four and one, respectively, for mumps and rubella viruses. The mean specific IgA titers were from 8- to 17-fold higher in MEF from immunized individuals than in the unimmunized and persisted for at least 9 to 19 months after immunization. The data thus indicate 1) specific immunologic sensitization of the middle ear mucosa can be achieved by parenteral as well as oral routes of immunization, and 2) specific immunologic memory exists in the middle ear mucosa. These two factors are crucial to feasibility of immunization against acute otitis media.
Clearing of the middle ear fluid in patients with acute otitis media due to Streptococcus pneumoniae or Haemophilus influenzae was significantly associated with the presence and concentration of specific antibody in the middle ear fluid at the time of diagnosis.
The antibody response in serum and middle ear fluid was studied in 40 children less than two years of age who had otitis media due to Haemophilus influenzae. Specific antibody in serum was determined by either a bacteriocidal test or an indirect fluorescent antibody test, and in the middle ear fluid by the latter test. For both assays the infecting bacterium of the patient was used. Half of the acute sera and three-fourths of the convalescent sera had antibody of at least one of the IgG, IgM, or IgA classes; IgG occurred most often. Fourteen patients had significant increases in specific antibody in the convalescent serum. Middle ear fluids from 22 to 29 patients had specific antibody. IgG and IgA antibodies occurred with equal frequency, but IgA antibody was found more often in middle ear fluids when IgA antibody was absent from serum. Thus it appears that infants with otitis media respond systemically and locally with specific antibody to H. influenzae.
Seventy percent of pneumococci isolated from the middle-ear cavity of infants and children with acute otitis media were of one of the seven serotypes 1, 3, 6, 14, 18, 19, or 23. The immunological response in the serum and middle-ear fluid from otitis media caused by one of these serotypes was studied in 61 children by using either indirect hemagglutination or indirect fluorescent antibody tests, or both. Twenty-six of the patients had pneumococcal antibody present in the acute serum and 28 had it in the convalescent serum by at least one method. Thirteen of the 49 middle-ear fluids examined had antibody by the indirect fluorescent antibody technique. Serum pneumococcal antibody was found to reside predominantly in the immunoglobulin G or immunoglobulin M classes, whereas pneumococcal antibody with middle-ear fluid was found to be distributed equally among all three classes. Approximately 25% of the patients (16 of 61) had a positive immune response to their infection as evidenced by increased levels of pneumococcal antibody in the convalescent serum. The percentage of patients responding immunologically increased with age: 12% of infants less than 12 months showed a significant response, whereas 48% of children over 24 months responded.
Immunoglobulin concentrations were studied in 255 specimens of middle ear fluid (MEF) from 165 episodes of acute otitis media in children. There were significant amounts of all three major immunoglobulins (Ig) in MEF, the mean concentration of IgA being 39 mg/100 ml, of IgM 63 mg/100 ml, and of IgG 383 mg/100 ml. Secretory component was present in all 10 MEF specimens in which it was sought. In patients over 9 months of age, there was a decreased likelihood of isolating pathogenic bacteria from MEF if the patient had higher concentrations of IgA in MEF than in simultaneously obtained serum. IgA concentrations were greater in MEF than in serum in almost half the patients, and the mean MEF-serum ratio for IgA was 1.38. Thus, it would appear that in this disorder MEF represents primarily a secretory response to inflammation rather than a transudate.
Explore the source record for details and available documents.
In a study of the efficacy of pneumococcal capsular polysaccharide vaccines in preventing otitis media due to Streptococcus pneumoniae, 179 infants were randomly assigned to receive either a "target" vaccine containing serotypes 1, 3, 6, 7, 14, 18, 19, and 23 (which account for most cases of pneumococcal otitis media) or a control vaccine containing serotypes 2, 4, 5, 8, 9, 12, and 25 (which account for few cases). Vaccine (0.5 ml) was administered subcutaneously; a dose contained 25 micrograms of each serotype. The incidence of otitis media due to "target" serotypes was determined in both groups. There were not significant differences between vaccines and controls in either the incidence or etiology of episodes of otitis media before immunization. During a two-year follow-up, no significant difference was observed regarding the incidence of episodes due to "target" serotypes in infants who were immunized after 12 months of age. However, of 66 control infants immunized before 12 months of age, 22 experienced 33 pneumococcal episodes due to a "target" serotype, whereas only 13 of 67 vaccines accounted for 22 such episodes. Among infants who had two or fewer episodes before immunization, four vaccines and 13 controls continued to have episodes of otitis media and became "otitis prone," i.e., six or more episodes (chi 2 = 4.84; P = 0.05). Low levels of serum antibody were not protective, and in one case a level of 609 ng of antibody nitrogen/ml of middle ear effusion was not protective. Thus, although the vaccine may be associated with a lower incidence of otitis media, the results of this study do not show a statistically significant efficacy of the vaccine.
Various immunological parameters were measured in serum, middle ear fluid (MEF), and lymphocytes from peripheral blood and MEF of infants with acute otitis media due to S. pneumoniae or H. influenzae. Approximately half of 131 patients had IgE specific antibody to the infecting bacterium as determined by the indirect fluorescent antibody (IFA) technique. Seventy-one percent of these IgE positive patients had IgE specific antibody in the MEF. Total IgE concentration was found to be from an average of 1.5 to 3.0 times higher in the MEF when compared to the simultaneously drawn serum. In addition, antibody to pneumococcal capsular polysaccharides and to pneumococcal C-carbohydrate was demonstrated in the MEF by radioimmunoassay. When MEF specific antibody was compared to serum antibody it appeared that antibody to C-carbohydrate was more concentrated in the MEF. That this antibody was of the IgE class was suggested by IFA but not conclusively proven. Evidence exists that conditions for enhanced IgE synthesis is concomitantly associated with a decrease in T-cell activity. T-cell function in MEF derived lymphocytes as determined by rosette formation and by phytohemagglutinin (PHA) stimulation was approximately one-tenth that of the peripheral blood lymphocytes. However, that T-cells may participate in the immune response to polysaccharides was suggested by the observation that polysaccharide stimulated peripheral blood lymphocytes from infants immunized with octavalent pneumococcal capsular vaccine underwent protein synthesis two to three times that of the PHA stimulated cells. The clinical significance of this finding as well as the nature of the cell responsible for the increased protein synthesis remains to be established. It is hypothesized that acute otitis media results from local synthesis of bacteria specific IgE antibody which is enhanced by a paucity of local T-cell activity.
Explore the source record for details and available documents.
IgE antibody directed against noncapsular antigens of mechanically disrupted Streptococcus pneumoniae, serotype 3 rough, was demonstrated in middle ear effusions (MEE) and serum of infants with and without prior evidence of pneumococcal otitis media with effusion (OME). The techniques employed included radioimmunoassay (RIA), passive skin testing, Prausnitz-Küstner (P/K), and enzyme-linked immunospecific assay (ELISA). Adsorption of MEE with ultrasonically disrupted crude pneumococcal antigen (CPA-U) resulted in a reduction of total IgE counts per minute and suggested bacteria-specific IgE antibody ranging from approximately 22 to 92% of the total IgE. The biological activity of the IgE antibody was confirmed by challenging skin passively sensitized with MEE IgE and CPA-U. Areas of induration appeared 20 minutes after challenge and continued to increase in size until 90 minutes. An ELISA procedure was developed as a tool to determine the nature of the antigen(s) and to determine the class(es) of antibody other than IgE. It appeared that CPA-U possesses free amino groups and that it can withstand the rigors of autoclaving. An analysis of 45 cord bloods revealed that high levels of IgG CPA-U antibody occur in this type of sample and that no correlation exists between the IgE and IgG levels. The mean IgG:IgE ratio, optical density at 420 nm (OD 420), for cord bloods was 2.49. In contrast, serum samples from nine infants without pneumococcal otitis media and from 14 infants with pneumococcal otitis media had lower levels of IgG antibody. There was no significant relationship between IgG and IgE OD 420 in infants who never had an episode of pneumococcal otitis media and the mean IgG:IgE was 1.88, whereas the ratio for those infants with pneumococcal otitis media was 1.56. In addition, there was a significant correlation between IgG and IgE levels in this latter group. The results suggest that it may be important to monitor the levels of at least these two classes of antibody to enhance our understanding of the pathogenesis and recovery from otitis media.
The serum antibody response to purified pneumococcal capsular polysaccharides (PCP) was detrmined in four groups of infants ranging in age from 3 to 24 months. Group 1 consisted of eight infants immunized with an octavalent vaccine containing serotypes 1, 3, 6, 7, 14, 18, 19 and 23 (PCP-8). Group 1 received 25 microgram of each serotype at 3-6 months of age and again at 18-24 months. The antibody response after the second immunization was compared to a group of nine patients receiving a primary immunization at 18-24 months and to a group of ten age-matched controls receiving saline placebo. There were no significant differences in mean serum antibody levels between the two groups receiving the PCP-8. A fourth group of 44 infants between 6 and 21 months of age received either PCP-7 or PCP-8 and were followed for two years, at which time simultaneous injections of both vaccines were administered. Types 2, 3, 7, and 8 were most immunogenic but levels six months after immunization were approximately the same as for unimmunized controls with the exception of serotypes 3 and 7 which persisted for about two years. The class of antibody induced either by natural infection or by immunization was preferentially IgG and it was more often induced by the former. There were no significant differences between the serotypes of pneumococci isolated from nasopharyngeal cultures regardless of which vaccine was administered. Finally, the least immunogenic serotypes include 4, 6, 14, 19, and 23 and these are the only serotypes thus far associated with otitis media after immunization. The results suggest that PCP do not induce a lasting immune tolerance at the dose administered in this study; PCP are not very immunogenic in the young infant; PCP antibody tends to rise naturally; IgG antibody is preferentially induced; nasopharyngeal colonization is not altered by PCP immunization; and an association may exist between PCP immunogenicity and subsequent onset of otitis media.