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Biomedical subjects

M Leinonen

Publications and source records attributed to M Leinonen.

At least 217 records · Page 12Linked to original sources
PubMed1984

Chlamydial pneumonitis and its serodiagnosis in infants.

Sera from 30 infants with suspected chlamydial pneumonitis were studied by enzyme immunoassay (EIA) with three antigens: reticulate bodies (RB), purified major outer membrane protein ( MOMP ) of Chlamydia trachomatis strain L2, and purified lipopolysaccharide from Re mutants of Salmonella (Re LPS), which shows complete cross-reaction with chlamydial glycolipid. The immunofluorescence test (I/RB IFAT), which detected IgM antibodies (titer of greater than or equal to 1:64) in 16 patients whose clinical picture was consistent with chlamydial pneumonitis, was the standard method. EIA measured IgM antibodies to the purified antigens but not to RB; 15 sera were positive with the MOMP antigen and two with the Re LPS antigen. High-titered IgG antibodies were detected by I/RB IFAT in 15 and by MOMP EIA in 13 of the 30 sera. By the RB EIA, 17 sera were positive. The MOMP EIA was thus as sensitive and specific as the I/RB IFAT. Because the EIA can be automated, it would make possible the screening of all children younger than six months of age with respiratory-tract symptoms and IgM antibodies to Chlamydia.

Bacterial Outer Membrane Proteins↗
PubMed1984

Immunologically related ketodeoxyoctonate-containing structures in Chlamydia trachomatis, Re mutants of Salmonella species, and Acinetobacter calcoaceticus var. anitratus.

The lipopolysaccharides (LPS) of Chlamydia trachomatis, Acinetobacter calcoaceticus var. anitratus, and Re mutants of Salmonella sp. were shown to share related immunodeterminants , as demonstrated by double immunodiffusion and immunoblotting from sodium dodecyl sulfate-polyacrylamide gel electrophoresis gels. The cross-reactive material in the extracellular slime of A. calcoaceticus var. anitratus was shown to be released LPS. The Acinetobacter LPS was found to separate in sodium dodecyl sulfate-polyacrylamide gel electrophoresis into three fractions. The cross-reactive component was the fraction migrating fastest, at a rate identical to Re-type LPS of Salmonella sp. The Acinetobacter LPS could be used as antigen in complement fixation assays performed on paired sera of patients with chlamydial pneumonia; it gave results identical to those of the chlamydial complement fixation glycolipid antigen conventionally used in such assays in 9 of 10 patients.

Acinetobacter↗
PubMed1983

Antigenic similarities between brain components and bacteria causing meningitis. Implications for vaccine development and pathogenesis.

Glycopeptides containing polysialic acid units were isolated from human and rat brain and tested for reactivity with antibodies against meningococcal capsules. The polysialosyl glycopeptides bound specifically to horse antiserum against meningococcus group B. The interaction was inhibited by capsular polysaccharides from meningococcus group B but not groups A or C. The capsular polysaccharide of Escherichia coli K1, which is immunochemically similar to the group B polysaccharide, also inhibited binding. These findings could explain the failure to develop efficient vaccines against group B meningococcus or E coli K1 and also suggest that immunological tolerance could be a factor in the pathogenesis of meningitis caused by these bacteria. The presence of the cross-reactive brain component calls for caution in efforts to develop capsular polysaccharide vaccines from these bacteria or the proposed use of passively administered antibodies as immunotherapy of neonatal meningitis.

Animals↗
PubMed1983

The genus-specific antigen of Chlamydia: resemblance to the lipopolysaccharide of enteric bacteria.

A strong immunological cross-reaction between a major glycolipid antigen of Chlamydia and the innermost (Re) core of the lipopolysaccharide of enteric bacteria was demonstrated with the aid of mutants in which the Re structure is exposed. The chlamydial glycolipid resembled the Re lipopolysaccharide in molecular size, solubility, and endotoxic properties and may thus be functionally equivalent to lipopolysaccharide, an essential and characteristic component of the outer membrane of Gram-negative bacteria.

Antigens, Bacterial↗
PubMed1983

Recurrent meningococcal meningitis due to partial complement defects and poor anti-meningococcal antibody response.

An otherwise healthy young man had three episodes of meningococcal meningitis within three years. The last episode was caused by group A, and occurred four weeks after the patient received group A vaccine, thus representing one of the very few failures of this vaccine. The specific susceptibility to meningococcal infections was connected with half-normal levels of several components of the complement system (C3, C4, C9, factor B, properdin), and reduced antibody responses to group A and group C meningococcal polysaccharides, but not to several other polysaccharide or protein antigens.

Adolescent↗
PubMed1983

Branhamella catarrhalis as a cause of bacteremic pneumonia.

A new enzyme immunoassay was used to confirm the pathogenetic role of Branhamella catarrhalis in a diabetic young man with pneumonia affecting the left lower lobe with pleural involvement. His temperature rise was only minimal, but his ESR and blood leucocyte count were elevated and one blood culture grew B. catarrhalis. The levels of branhamella antibodies of the IgG and IgA classes were high and rose during the infection.

Adult↗
PubMed1983

Possibilities of preventing otitis media by vaccination.

The prerequisites for preventing a considerable proportion of acute otitis media (AOME) of children are theoretically good--pneumococcal types/groups present in the available 14-valent pneumococcal capsular polysaccharide vaccine are the most common bacteria in AOME, and a good serum antibody response is followed by type-specific protection from infection. However, the four most common types/groups (= 2/3 of all pneumococci in AOME) have very poor immunizing capacity in infants, and therefore the vaccine offers little protection from AOME for children under the age of 2 years. This information should help towards an improved new vaccine for AOME.

Acute Disease↗
PubMed1982

Class-specific antibody response to group B Neisseria meningitidis capsular polysaccharide: use of polylysine precoating in an enzyme-linked immunosorbent assay.

An enzyme-linked immunosorbent assay was developed for measuring immunoglobulin class-specific antibodies to Neisseria meningitidis capsular polysaccharides. The polysaccharides were fixed to the solid phase by precoating the polystyrene surface with basic polyamino acids. Polylysine precoating was found to give optimal antibody values with the meningococcal polysaccharides studied. The enzyme-linked immunosorbent assay was used to measure antibodies against group B meningococcal polysaccharide in healthy adults and in patients with group B meningitis. Antibodies to group B polysaccharide in sera obtained from healthy adults were primarily immunoglobulin M (IgM). Although the antibody response to disease was mostly IgM, both IgG and IgM antibodies increased. Infection with group B organisms stimulated anti-group B polysaccharide antibodies even in young patients, aged 6 to 7 months, and the magnitude of the B polysaccharide response increased with the age of the patient.

Adolescent↗
PubMed1982

Screening of bacteria in urine using luciferin-luciferase assay of microbial ATP: a comparative study.

A total of 3227 urine specimens were analysed to investigate the applicability of a firefly luciferase assay of microbial adenosine triphosphate (ATP) for the rapid screening of bacteriuria in clinical specimens. Urine sediment, dipslide culture, and three plate cultures were also investigated in the majority of the urine specimens, the plate cultures serving as the reference. Of the specimens with positive plate culture (greater than or equal to 10(5) colony forming units (CFU)), leucocyte content of the spun urine sediment was negative (less than or equal to 4 cells per high-power field) in 34% and bacterial content was negative in 14% (no bacteria seen microscopically); the dipslide test was negative (less than 10(5) CFU) in 16%, and the luminescence assay of ATP in 7% (less than or equal to 500 relative light units). Of the urine specimens forming less than 10(5) CFU on plate cultures, leucocytes were positive in 15%, spun sediment bacteria in 21%, the dipslide test in 0.5%, and the luminescence assay of ATP in 11%. When used as a screening test for further studies by complete culture techniques, the luminescence assay of microbial ATP can improve the rapid diagnosis of urinary tract infections.

Adenosine Triphosphate↗
PubMed1982

Adverse reactions to polyvalent pneumococcal vaccine.

Adverse reactions to the polyvalent pneumococcal polysaccharide vaccine were evaluated with respect to age of the vaccinees and the route of administration. When either pneumococcal or influenza virus vaccine was administered by subcutaneous injection in a randomized single-blind study to 181 persons aged 60 to 85 years, local reactions were similar: one-third of the vaccinees complained of soreness at the injection site, whereas 90% had some local reaction (erythema, induration or soreness). Only 3/90 recipients of the pneumococcal vaccine and none of those who received the influenza vaccine had a slight rise in temperature (37.4-38.5 degrees C). Most reactions subsided within 2 days. When the pneumococcal vaccine was given to 100 healthy firemen (mean age 31 years), local soreness was more common (76%) than among the old people (p less than 0.001), and fever was significantly more frequent (12%; p less than 0.05). Local soreness lasted somewhat longer after intramuscular (mean 42.5 h) than after subcutaneous (mean 32.5 h, p less than 0.05) injection, whereas local erythema was more common after subcutaneous (80%) than after intramuscular (38%) injection (p less than 0.001). The presence of reactions correlated with a higher concentration of antibodies to the vaccine polysaccharides.

Age Factors↗
PubMed1982

Antibody responses against pneumococcal polysaccharide antigens in vaccinated persons.

The pneumococcal capsular polysaccharide vaccine protects healthy adults from pneumococcal infections. High-risk patients have generally impaired antibody responses and are only partly protected by vaccine. Infants less than 2 years old respond poorly to pneumococcal polysaccharide vaccine. But the pneumococcus is an important bacterial pathogen in young children and a protective vaccine is needed for this age group. The immunogenicity of capsular polysaccharides may be enhanced by preparing protein-polysaccharide conjugates and these preparations would help in the development of more effective vaccine for prevention of pneumococcal disease.

Adult↗
PubMed1981

Preliminary serologic evidence for a pathogenic role of Branhamella catarrhalis.

Branhamella catarrhalis has been suspected, on the basis of bacteriologic culture results, to have a pathogenic role in 6%-9% of cases of acute otitis media as well as in other upper respiratory tract infections. Serologic evidence of this role was obtained with use of an enzyme immunoassay to detect antibodies to B. catarrhalis. The presence of both IgG and IgA antibodies to Branhamella in the serum and/or middle ear fluid (MEF) of children with acute otitis media correlated with the isolation of B. catarrhalis from cultures of their MEF. An increase in titer of antibodies to Branhamella between acute-phase and convalescent-phase serum samples was found in 10 of the 19 children with otitis media from whom B. catarrhalis but no other pathogen was isolated from the MEF. Such an increase was found in none of the 14 children with otitis media caused by other organisms.

Animals↗
PubMed1981

Comparison of ELISA and RIA for measurement of pneumococcal antibodies before and after vaccination with 14-valent pneumococcal capsular polysaccharide vaccine.

Antibody responses to the 14-valent pneumococcal capsular polysaccharide vaccine in children under school age were measured by enzyme-linked immunosorbent assay (ELISA) and radioimmunoassay (RIA). Specific IgG and IgM antibodies were usually detectable by ELISA in the prevaccination sera, and one or both of them increased as a response to the vaccination. Specific IGA antibodies were detected by ELISA in a part of the post-vaccination sera only. The frequency of the IgA responses increased with the age of the children. The correlation of the ELISA results with RIA was good (r from 0.652 to 0.812) except for type 6A (r = 0.471).

Antibodies, Bacterial↗
PubMed1981

The bacteriology of acute otitis media in children with special reference to Streptococcus pneumoniae as studied by bacteriological and antigen detection methods.

The middle ear fluid (MEF) was studied during an acute attack of otitis media in 519 children, aged 3 months to 6 years. Streptococcus pneumoniae (Pn) was cultured from 39% of the cases; serotypes 19, 6, 3 and 23 were the most common. Haemophilus influenzae (Hi) was cultured in 12%; only 2/64 strains were of type b. Pn were found equally often in all age groups, but Hi were significantly less often isolated in children older than 3 years. The number of negative cultures increased with the age of the child. Pneumococcal capsular polysaccharide was detected with counterimmunoelectrophoresis and/or latex agglutination in 83% of the MEFs from which Pn were cultured, but also in about one third of the MEFs from which no bacteria could be grown. Altogether, with these methods combined Pn were implicated in nearly 60% of the cases of acute otitis media. Gram staining showed polymorphonuclear leucocytes in 85% of pneumococcal otitis cases that were verified by culture but also in 72% of the cases from which no bacteria could be cultured, supporting the contention that also these latter are usually caused by bacteria.

Acute Disease↗
PubMed1980

Pneumococcal vaccine and otitis media.

After an acute attack of otitis media 827 children aged 3 months to 6 years were assigned randomly to receive either 14-valent pneumococcal polysaccharide vaccine or a control vaccine (Haemophilus influenzae type b capsular polysaccharide). In children older than 6 months serum antibody responses to most of the vaccine polysaccharides were satisfactory. The response to type 6A was poor. Correspondingly, no clinical protection was seen below 6 months of age or against otitis media caused by group 6 pneumococci. Among the children more than 6 months old, the first 6 months after vaccination saw significantly (p < 0.001) fewer attacks caused by the pneumococal types represented in the vaccine (group 6 excepted) in those who received the pneumococcal vaccine than in those who received the control vaccine. Protection against type 19F was statistically significant (p < 0.01). The overall protective efficacy was 58%--somewhat better in children older than 2 years than in those younger. Previous attacks of otitis caused by pneumococci did not influence the protective efficacy of the vaccine.

Age Factors↗
PubMed1979

Serological grouping of meningococci and encapsulated Haemophilus influenzae strains by latex agglutination.

The latex agglutination method, utilizing antibody-coated latex particles, was adapted for serogrouping of Neisseria meningitidis and serotyping of encapsulated Haemophilus influenzae strains from agar plates. It was found to give more clear-cut results than conventional slide agglutination. A 100% agreement with the antiserum agar method was found for all strains isolated from blood or cerebrospinal fluid. Many meningococcal strains from nasopharyngeal carriers are autoagglutinable, but some of these gave a positive reaction with the group B latex reagent, although they were negative by the antiserum agar method. The latex agglutination method has several advantages over others: the lack of autoagglutination, easy performance, easy interpretation, and very low consumption of antisera.

Blood↗
PubMed1979

Are changes in serum immunoglobulin and complement levels following open heart surgery influenced by oxygenator type or postoperative parenteral nutrition?

The serum IgG and IgA concentrations significantly decreased through the seventh day and the serum IgM and complement (C3 and C4) concentrations through the second day after elective open heart surgery for heart valve disease in a series of 16 patients. A significant increase over the preoperative concentration was seen, however, in the serum IgA, IgM, C3 and C4 on day 14 postoperatively. The serum IgG and IgM concentrations declined significantly only in patients perfused by a bubble oxygenator, although the two small series of patients perfused by bubble and membrane oxygenator did not differ significantly from each other. Parenteral nutrition had no effect on postoperative changes in serum immunoglobulin and complement concentrations.

Adolescent↗