Search PubMed⌕ Search

Biomedical subjects

E M Ayoub

Publications and source records attributed to E M Ayoub.

At least 37 records · Page 2Linked to original sources
PubMed1994

Haemophilus influenzae type B invasive disease in urban and rural children: immunization patterns and prevalence of disease.

To examine the impact of the introduction of Haemophilus influenzae type b (Hib) conjugate vaccine, we reviewed the incidence of Hib invasive disease in the state of Florida from 1984 to 1992. We analyzed the incidence of disease in two populations of children, one residing in an urban area and the other in a rural area. This study was designed to compare incidence rates prior to and following the introduction of Hib vaccine for children. Our data show a > 80% decrease in the incidence of Hib invasive disease in the state of Florida and a similar decrease in both the urban and rural populations examined. Analysis of the data revealed that the majority of children contracting Haemophilus influenzae type b invasive disease in both populations were either not immunized or were only partially immunized.

Child, Preschool↗
PubMed1993

Poststreptococcal anti-myosin antibody idiotype associated with systemic lupus erythematosus and Sjögren's syndrome.

Anti-myosin antibodies are found in acute rheumatic fever (ARF), a sequela of group A streptococcal infection. An antiidiotypic serum was produced that was specific for idiotopes expressed by anti-myosin antibodies in ARF (anti-My1). Studies indicated that idiotypic determinants detected with this serum were present in anti-myosin antibodies and absent from normal human immunoglobulins that lacked specificity for myosin. Anti-My1 was tested against sera from patients with other types of autoimmune diseases as well as uncomplicated streptococcal infections. Sera from systemic lupus erythematosus (SLE), Sjögren's syndrome (SS), and poststreptococcal acute glomerulonephritis patients demonstrated idiotypic reactivity with anti-My1. Affinity-purified anti-myosin antibodies from SLE, SS, and ARF sera also reacted strongly with anti-My1, indicating that immunoglobulins produced in these diseases share idiotypic determinants. The data demonstrated an association of the My1 idiotype with poststreptococcal sequelae and the two autoimmune diseases SLE and SS.

Autoantibodies↗
PubMed1993

Ehrlichia chaffeensis and Rochalimaea antibodies in Kawasaki disease.

Sera from 38 patients with Kawasaki disease were tested for immunofluorescent antibodies to Ehrlichia chaffeensis, Rochalimaea henselae, and R. quintana Oklahoma. Only 2.5% of the patients tested positive for E. chaffeensis, and 5% were positive for R. henselae and R. quintana Oklahoma. Our data suggest that Ehrlichia and Rochalimaea spp. do not play a unique role in the etiology of Kawasaki disease.

Antibodies, Bacterial↗
PubMed1992

Resurgence of rheumatic fever in the United States. The changing picture of a preventable illness.

The recent resurgence of rheumatic fever reported in eight locations in the United States after years of decline has several noteworthy characteristics. Most patients were children of families in high- to middle-income brackets with ready access to medical care. In four of the outbreaks, the majority of patients were adults, who were more likely than children to have arthritis and less likely to have Sydenham's chorea. Many patients had no clinical history of streptococcal pharyngitis. Rheumatic fever developed in some patients despite antibiotic treatment for streptococcal pharyngitis. Analysis of the outbreaks supports the following conclusions: No population is exempt from rheumatic fever. Physicians should be diligent in performing throat cultures in cases of suspected streptococcal pharyngitis. The efficacy of orally administered penicillin in preventing rheumatic fever should be reexamined, and oral antibiotics that are potentially more effective should be sought.

Adult↗
PubMed1991

Group B streptococcal C protein-associated antigens: association with neonatal sepsis.

The c protein (Ibc) of group B streptococci (GBS) is associated with at least four antigens (alpha, beta, gamma, delta). To assess the virulence potential of these antigens, 255 GBS isolates recovered from septic neonates, healthy neonates, and pregnant women were serotyped and surveyed for reactivity with sera to c protein and the four associated antigens. A radioimmunoassay using intact bacteria was used to detect the GBS antigens. In contrast to earlier reports, most (66%) of the type III strains expressed the c protein. Except for the gamma antigen, none of the other c protein-associated antigens showed an increased association with pathogenic strains independent of the polysaccharide antigens. The gamma antigen was expressed by 15 of 41 c protein-positive early-onset strains and by 4 of 38 c protein-positive late-onset strains (P = .007). This association was independent of the type-specific antigen, suggesting a potential role for the gamma antigen as a virulence factor in GBS strains causing early-onset sepsis.

Antigens, Bacterial↗
PubMed1991

Immunogenicity and reactogenicity of Haemophilus influenzae type b-meningococcus group B outer membrane protein conjugate vaccine in children 2-60 months of age.

Haemophilus influenzae b - Neisseria meningitidis group B outer membrane protein conjugate vaccine (Hib-OMP) was given to 571 children 2-60 months of age. Two doses of Hib-OMP were given, 2 months apart, to 2-11 month old infants, and a single dose to children 12-60 month old. Sera were obtained from a subset of vaccinees at each immunization, and at follow-up 1 month and 1 year after immunization. Geometric mean antibody concentration (micrograms/ml) before and after full immunization were respectively 0.111 and 3.549 for 2-3 month old, 0.108 and 5.048 for 4-5 month old, 0.082 and 6.933 for 6-11 month old; they were 0.103 and 3.500 for 12-17 month old, 0.167 and 7.791 for 18-23 month old and 0.243 and 12.781 for children greater than or equal to 24 months. Detectable antibody (greater than or equal to 0.125 micrograms/ml) failed to develop in 2/399 (0.5%) after primary immunization, and 12/252 (4.8%) lost detectable antibody 1 year later. Six of these 12 infants were less than 12 month old. The vaccine was immunogenic as early as 3-5 months of age. The need for booster immunization needs to be assessed.

Age Factors↗
PubMed1991

Lack of IgG4 antibody response to carbohydrate antigens in patients with lymphatic filariasis.

It has been suggested that humans are genetically restricted from making IgG4 antibody responses to carbohydrate antigens. To test this hypothesis we examined sera from 35 patients with bancroftian filariasis (an infection known to induce very high levels of IgG4 antibodies to the parasite and known to be associated with repeated streptococcal infections) as well as from 15 normal individuals for their IgG and IgG subclass responses to streptococcal protein [streptolysin-O (SO), deoxyribonuclease B (DB)] and carbohydrate [group A carbohydrate (GAC)] antigens. Levels of IgG antibodies to all three antigens were found to be significantly higher in the filariasis patients compared to normals (P less than 0.01), and the subclass composition of these antibodies proved heterogenous. Although responses to all three antigens included IgG1, IgG2 and IgG3 antibodies and although IgG4 responses to the proteins SO and DB were significantly higher in the filariasis patients than in normals (P less than 0.001), more importantly there were no detectable anti-GAC IgG4 antibodies in either study group. These observations, coupled with our earlier finding of the absence of IgG4 responses to phosphocholine (PC) in patients with lymphatic filariasis, suggest that even the chronic antigenic stimulation of filarial helminth infection, which leads to very prominent IgG4 responses to protein antigens, cannot overcome the genetic restriction in humans for making IgG4 antibodies to carbohydrate antigens, whether of parasite or non-parasite origin.

Adolescent↗
PubMed1991

Host-parasite interaction in the pathogenesis of rheumatic fever.

Recent investigation has delineated some of the bacterial and host factors that may play a role in the pathogenesis of rheumatic fever. Continuing studies support the role of antibodies to crossreactive antigens in human tissues and the group A streptococcal cell in inducing tissue damage associated with this disease. Several specific epitopes have now been defined that are common to the crossreactive antigens. Data from recent outbreaks of rheumatic fever in the USA suggest that mucoid group A streptococcal strains, belonging to serotypes M1, M3, M5, M6 and M18 may have accounted for these outbreaks. While these strains are thought to be rheumatogenic, the exact characteristic(s) that renders them so is yet to be determined.

Host-Parasite Interactions↗
PubMed1991

Community-wide outbreak of group G streptococcal pharyngitis.

Although several outbreaks of group G beta-hemolytic streptococcal (GGBHS) pharyngitis have been described, doubt still remains regarding the etiologic role of GGBHS in acute pharyngitis beyond a limited number of situations. In the winter/spring of 1986/87, throat cultures were obtained from 222 consecutive children seen at a private pediatric office with acute pharyngitis and group A beta-hemolytic streptococci (GABHS) were recovered from 91 children (41%) and GGBHS from 56 children (25%). One patient had both GABHS and GGBHS isolated. This isolation rate of GGBHS was dramatically greater than in previous and subsequent years, and 67% of the GGBHS isolates occurred during an 8-week period. Results of DNA fingerprinting of the 57 isolates of GGBHS demonstrated that 43 (75%) appeared to be the same strain. The patients with GGBHS were comparable to those with GABHS with respect to clinical findings, antistreptolysin-O titer response, and clinical response to antibiotic therapy. However, patients with GGBHS were significantly older (P less than .05). This is the first well-documented, community-wide outbreak of GGBHS pharyngitis and the first respiratory outbreak of GGBHS pharyngitis in a pediatric population. GGBHS may be a more important cause of acute, treatable pharyngitis than had been previously recognized.

Adolescent↗
PubMed1989

Toxic shock syndrome caused by a strain of Staphylococcus aureus that produces enterotoxin C but not toxic shock syndrome toxin-1.

An 8-month-old infant presented with pneumonia and pleural effusion associated with clinical manifestation of toxic shock syndrome. A Staphylococcus aureus strain isolated from the pleural fluid produced enterotoxin C, but not toxic shock syndrome toxin-1 or other enterotoxins. Acute and convalescent sera showed an antibody rise to enterotoxin C but not to toxic shock syndrome toxin-1. These findings support the possibility that enterotoxin C was the primary toxin associated with this infant's illness.

Bacterial Toxins↗
PubMed1989

High prevalence of obsessive-compulsive symptoms in patients with Sydenham's chorea.

The 20-item Leyton Obsessional Inventory--Child Version was completed by children and adolescents who had had Sydenham's chorea (N = 23) or rheumatic fever without chorea (N = 14). The Sydenham's chorea subjects had significantly more obsessive thoughts and compulsive behaviors and significantly greater interference from these behaviors. Three Sydenham's chorea patients but no rheumatic fever patients had substantial obsessional interference and met criteria for obsessive-compulsive disorder when interviewed by telephone. This suggests that obsessive-compulsive disorder, at least in some patients, may be due to basal ganglia dysfunction.

Adolescent↗
PubMed1988

Human monoclonal antibodies reactive with antigens of the group A Streptococcus and human heart.

Human mAb were produced from tonsillar or PBL of normal individuals or patients infected with group A streptococci. Lymphocytes were purified on Ficoll-Hypaque gradients and stimulated in vitro with purified group A streptococcal membranes or M protein extracts. The mAb were selected for study based on their reaction with group A streptococci, pep M5 protein, and/or M6 Escherichia coli protein. Further analysis by Western immunoblot or competitive inhibition ELISA revealed that there were two types of antibodies: one type that reacted with myosin and DNA and the other type that reacted with myosin, keratin, and/or actin. The specificities of these human mAb are similar to specificities observed in our previous studies of murine mAb reactive with group A streptococci and heart Ag. For comparison, anti-myosin antibodies were affinity purified from the sera of infected or acute rheumatic fever patients and were shown to react with myosin and DNA as well as with group A streptococci and M protein. To affinity purify these antibodies from normal sera, five times the amount of sera was required to obtain detectable quantities. These data suggest that the human mAb reactive with group A streptococci and myosin reflect the antibodies seen in sera from infected patients or acute rheumatics and that the B lymphocyte clones capable of producing these cross-reactive antibodies are also present in normal individuals.

Antibodies, Bacterial↗