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Biomedical subjects

J Jero

Publications and source records attributed to J Jero.

31 records · Page 2Linked to original sources

Bacteriological findings and persistence of middle ear effusion in otitis media with effusion.

The bacteriology of middle ear effusion (MEE) of asymptomatic otitis media with effusion (OME) was studied in 165 children, aged 5 months to 12 years, from the MEE samples obtained during tympanostomy under general anaesthesia in 1993-1994. MEE had persisted for 1 to 12 (mean 3.5) months. Major otitis pathogens (S. pneumoniae, H. Influenzae, B. catarrhalis and S. pyogenes) were cultured in 41% of the children under 2 years of age and in 17% of older children (p < 0.001). Respiratory infections and attacks of acute otitis media (AOM) during the last 6 months were also more frequent in children younger than 2 years (p < 0.001). The proportion of S. pneumoniae (25%) and H. influenzae (38%), but not of other bacteria, was higher in the children with less than 2 months' persistence of MEE as compared with those with a longer duration (8% and 3%) (p < 0.01). After 2 months, the occurrence of different bacteria remained relatively unchanged until 6 months' persistence of MEE, and thereafter no pathogens were culturable. Among the children adenotomized earlier, the proportion of those with major otitis pathogens in MEE was 8% compared with 32% in non-adenotomized children (p = 0.02). S. pneumoniae, B. catarrhalis or S. pyogenes were not culturable in any of the adenotomized children, while MEE grew them in 25% of the non-adenotomized children (p < 0.001). Since the MEE bacteriology of OME with less than 2 months' persistence resembles that of AOM, it may be that these cases represent a transitory phase between AOM and an established OME.

Adenoidectomy↗

Prognosis of acute otitis media. Factors associated with the development of recurrent acute otitis media.

Clinical factors associated with the development of recurrent acute otitis media (RAOM) (> or = 3 recurrences during 6 months' follow-up period) after acute otitis media (AOM) were analysed in 121 children aged 3 months to 7 years (median 2 years 6 months). After AOM, 19 (16%) children had primary recurrence (pre-treatment signs and symptoms firstly improved or cured, but worsened or recurred within 30 days' post-treatment) and 33 (27%) developed RAOM during 6 months' follow-up period. It seemed that children < 2 years of age (p = 0.04), children with bilateral disease (p = 0.007), strong infection status (p = 0.05), primary clinical failure (p = 0.04) and development of primary recurrence after AOM (p = 0.001) were significantly related to the development of RAOM in univariate analysis, but only children < 2 years of age (OR 1.5, 95% CI 1.0-5.7, p = 0.04) and the development of primary recurrence (OR 5.1, 95% CI 1.8-14.1, p = 0.002) related to the development of RAOM in multivariate analysis. None of the bacteria cultured from middle ear effusion were related to the development of RAOM.

Acute Disease↗

Antibody-secreting cells and their relation to humoral antibodies in serum and in nasopharyngeal aspirates in children with pneumococcal acute otitis media.

Mucosal and systemic antibody responses to pneumococcal capsular polysaccharide were studied in 17 children with culture-verified pneumococcal acute otitis media. Serotype-specific antibody-secreting cells (ASCs) in peripheral blood and antibodies in acute and convalescent sera and nasopharyngeal aspirates were measured. A polysaccharide-specific ASC response was induced in all subjects. The response was age dependent, and the dominant antibody class was IgA. Three children > 24 months old had > 100 IgA-class ASCs/10(6) cells and serum and nasopharyngeal IgA responses; 2 had only a nasopharyngeal IgA response. None of 8 children < 24 months old showed a systemic response; however, a nasopharyngeal IgA response was detected in 1. Results suggest that whole pneumococci can induce a mucosal polysaccharide-specific antibody response independent of the systemic response. Results are also in accordance with earlier studies suggesting that the mucosal immune system matures earlier in life than does the systemic immune response.

Acute Disease↗

Comparison of serum antibodies to pneumolysin with those to pneumococcal capsular polysaccharides in children with acute otitis media.

BACKGROUND: Streptococcus pneumoniae is a major bacterial pathogens in acute otitis media. Pneumolysin is a species-specific protein toxin produced intracellularly by all clinically relevant pneumococcal strains, and antibodies to pneumolysin should therefore represent pneumococcal involvement in the disease, regardless of the serotype. METHODS: Antibodies to pneumococcal pneumolysin and capsular polysaccharides were measured by enzyme immunoassay in acute and convalescent sera of 121 children with acute otitis media. A pneumococcal otitis episode was defined by a positive middle ear fluid culture and/or pneumolysin PCR. RESULTS: Median age of the 10 children who developed a seroconversion response to pneumolysin was 1 year 8 months, and of the 21 children responding to polysaccharides it was 2 years 9 months. Eight of the 10 seroconversion responses to pneumolysin were of IgA class alone, whereas 17 of the 21 polysaccharide responses were of IgG class alone or IgG together with IgM and/or IgA. Of the 41 children with a pneumococcal otitis episode, 13 (39%) showed a seroconversion response, 3 (7%) to pneumolysin and 11 (27%) to capsular polysaccharides. The children with a pneumococcal otitis episode had lower titers of acute phase IgG to the capsular polysaccharide pool of S. pneumoniae (containing types 6B, 14, 19F and 23F), as compared with the titers in children with otitis caused by other pathogens and pneumococci only in the nasopharynx or not found at all (P = 0.04). CONCLUSIONS: Serum antibodies to pneumolysin can be detected at an earlier age than those to the capsular polysaccharides. However, a seroconversion is rare and therefore of no diagnostic value. The presence of serum IgG to the pneumococcal capsular polysaccharides seems beneficial in the prevention of pneumococcal otitis.

Acute Disease↗

PCR assay for detecting Streptococcus pneumoniae in the middle ear of children with otitis media with effusion.

We compared a newly developed pneumococcal polymerase chain reaction (PCR) for Streptococcus pneumoniae (Pnc) to bacterial culture in 123 middle ear effusion (MEE) samples of 123 children with otitis media with effusion (OME). For the pneumococcal PCR assay, DNA of MEE samples was purified by a QIAamp blood kit. The outer primers used amplified a 348 basepair region of the pneumolysin gene, and the inner a 208. Pnc was cultured in 14 (11%) and pneumolysin PCR was positive in 57 (46%) of the 123 MEE samples. All the culture positive samples were also PCR-positive. Both the samples with culturable Pnc and with positive pneumolysin PCR increased with shorter duration of OME and a greater number of acute otitis media during the preceding 6 months. In conclusion, pneumolysin PCR suggests pneumococcal involvement in MEE even in OMEs with no evidence of Pnc in culture, and thus offers a good diagnostic tool when a more accurate and sensitive pneumococcal diagnosis is needed.

Acute Disease↗

Risk factors for primary invasive pneumococcal disease among children in Finland.

OBJECTIVE: To study risk factors for invasive pneumococcal disease among children. DESIGN: A population-based, case-control study of 149 cases and 284 controls matched for age, sex, and place of residence. SETTING: Finland, November 1986 through November 1989. PATIENTS AND CONTROLS: Patients were identified from a prospective nationwide surveillance for invasive bacterial diseases among children (0 to 15 years of age) through a network of bacteriologic laboratories. Two matched controls were selected for 135 of the cases and one matched control for 14 of the cases from the respective cases' child health center or school. Questionnaires evaluating potential risk factors were mailed to families of cases and controls. RESULTS: An increased risk for invasive pneumococcal disease among children younger than 2 years was associated with day care center attendance (odds ratio [OR] = 36; 95% confidence interval [CI], 5.7 to 233), family day care (OR = 4.4; 95% CI, 1.7 to 12), and history of frequent otitis media (OR = 8.8; 95% CI, 2.5 31). For those at least 2 years of age, existence of siblings younger than school-age indicated increased risk for invasive pneumococcal disease (OR = 2.2; 95% CI, 1.1 to 4.4). CONCLUSIONS: Day care center attendance is a major risk factor for invasive pneumococcal disease for children younger than 2 years, with significantly higher risk than the risk associated with family day care.

Adolescent↗

Nasopharyngeal antibodies to pneumococcal capsular polysaccharides in children with acute otitis media.

Antibodies to pneumococcal capsular polysaccharides were measured by EIA in acute- and convalescent-phase nasopharyngeal aspirates from 120 children with acute otitis media. Nasopharyngeal IgM- and IgG-class antibodies were rare, whereas IgA was detected more often, occurred independently from serum IgA, and correlated with the presence of the secretory component in pneumococcal antibody, indicating local production of IgA. Thirty-four percent of the children with pneumococci in middle ear fluid developed a nasopharyngeal IgA response to the polysaccharide pool of serotypes 6B, 14, 19F, and 23F compared with 7% of the children with pneumococci only in the nasopharynx or not found at all (P = .004). The responses were observed in children of all ages, the youngest 6 months of age. This supports the hypothesis that mucosal immunity to bacterial polysaccharides matures earlier than systemic immunity.

Acute Disease↗

Nasopharyngeal antibodies to pneumococcal pneumolysin in children with acute otitis media.

Pneumolysin, an intracellular protein toxin of all clinically relevant pneumococcal serotypes, is released in vivo during the autolysis of pneumococci and is believed to pave the way for intact pneumococci to invade and cause disease. Therefore, antibodies to pneumolysin should prevent its destructive function. We measured antibodies to pneumococcal pneumolysin in acute- and convalescent-phase nasopharyngeal aspirate samples of 120 children (median age, 2.5 years) with acute otitis media by enzyme immunoassay. Nasopharyngeal immunoglobulin M (IgM) and IgG class antibodies to pneumolysin were rarely detectable, whereas IgA class antibody was detected often, occurred independently of serum IgA antibody in serum, and correlated with the presence of the secretory component in pneumococcal antibody, indicating local production of IgA antibodies. Nasopharyngeal IgA antibody to pneumolysin was detected in 93% of the children already in the acute phase of otitis. Twenty percent of the children developed at least a threefold rise in the pneumolysin-specific IgA antibody concentration by the convalescent phase of otitis, with the youngest at 6 months of age, regardless of the pneumococcal findings in the nasopharynx or middle ear fluid. We suggest that nasopharyngeal IgA antibody to pneumolysin can be produced early in life by pneumococcal colonization.

Acute Disease↗

Antibodies to pneumolysin and pneumococcal capsular polysaccharides in middle ear fluid of children with acute otitis media.

Antibodies to pneumococcal pneumolysin and capsular polysaccharides were measured by enzyme immunoassay in 169 acute phase middle ear fluid samples of 116 children with acute otitis media. Antibodies to pneumococcal pneumolysin were detected in 84% and to capsular polysaccharides in 50% of the MEF samples. The Ig class detected most often was IgA to both types of pneumococcal antigens, and it was present in MEF even with non-detectable levels of serum IgA of the same specificity. 59% of the MEF samples positive for IgA to pneumolysin were also positive for secretory component of the same specificity, and 53% of IgA to capsular polysaccharide pool (containing serotypes 6B, 14, 19F, and 23F), respectively. This suggests both leakage of specific IgA from serum to the middle ear and local production of it. In contrast, specific IgG was detected in MEF only with concomitant IgG in serum. Antibodies to pneumolysin occurred in no relation to bacterial findings in MEF. On the contrary, IgG class antibodies to capsular polysaccharides, most likely serum-derived, were detected less often in MEF samples positive for pneumococcus than for other bacteria.

Antibody Formation↗

Comparison of PCR assay with bacterial culture for detecting Streptococcus pneumoniae in middle ear fluid of children with acute otitis media.

We have studied etiological diagnosis of acute otitis media (AOM) by comparing a newly developed pneumococcal PCR for Streptococcus pneumoniae to bacterial culture with 180 middle ear fluid (MEF) samples of 125 children with 125 episodes of AOM. For pneumococcal PCR assay, DNA from MEF samples was extracted by phenol-chloroform. The outer primers used amplified a 348-bp region of the pneumolysin gene, and the inner primers amplified a 208-bp region. S. pneumoniae was cultured in 33 (18%) samples, and pneumolysin PCR was positive for 51 (28%) of 180 MEF samples. Only 2 of 21 PCR-positive, S. pneumoniae culture-negative samples were positive for other otitis pathogens. By combining MEF culture and PCR results, 54 (30%) of 180 MEF samples had evidence of pneumococcal etiology. In conclusion, pneumolysin PCR is a sensitive and specific new method to study pneumococcal involvement in MEF samples of children with AOM.

Acute Disease↗

New method to assess dilution of secretions for immunological and microbiological assays.

Accurate quantitation of pathogens and antibody concentrations in secretions has been difficult because of unpredictable dilution of secretion with th diluent at the time of sample collection. We added an inert substance, lithium chloride (LiCl), to the sample diluent and measured its concentration with an atomic absorption spectrometer before and after the specimen was added. LiCl, at a concentration of 2 mmol of Li per liter, has no negative effect on the survival of common respiratory pathogens or on the results of immunoassays. The method is applicable to any sample collecting in which dilution of the specimen is necessary.

Antibodies↗