PubMed Health⌕ Search

Biomedical subjects

K Prellner

Publications and source records attributed to K Prellner.

At least 19 recordsLinked to original sources
PubMed1992

Blood T and B lymphocyte subpopulations in healthy infants and children.

Monoclonal antibodies and flow cytometry are now used routinely in the diagnosis of many malignant diseases and primary and secondary immunodeficiency states. Technical advances have improved the identification of blood lymphocyte subsets and reliable normal values are now obtainable. Such values have been reported for adults but not for children. We report both absolute and percentage normal values for lymphocytes and their subsets in infants and children of different ages. Our findings show that the absolute and percentage values for most lymphocyte markers differ substantially not only between children and adults, but also between children from different age groups. In infants, erythroid cell contamination of Ficoll gradient-density isolated mononuclear cells must be removed to obtain reliable flow cytometry values.

Adult↗
PubMed1992

Mucosal immunoreactivity in experimental pneumococcal otitis media.

A rat model was used to investigate immunological events in the middle ear mucosa during pneumococcal acute otitis media (AOM). Twelve healthy male Sprague-Dawley rats were challenged in the right middle ear with Streptococcus pneumoniae type 3, the presence of AOM being confirmed by otomicroscopy. Randomly selected rats, four at a time, were sacrificed on days 7, 14 and 56 after bacterial challenge. Immunohistochemical staining for IgG, secretory IgA (SIgA), and IgM was performed on tissue specimens from four separate locations in the middle ear and tubal mucosa. Immunoglobulins, especially IgG, were found around blood vessels in the middle ear mucosa. Immunoreactive lymphoid cells of all three Ig classes investigated, undetectable before bacterial challenge, appeared within 7-14 days after middle ear challenge, and the location of these cells in the middle ear mucosa suggests the presence of IgG, SIgA, and IgM, respectively. On the other hand, reactivity with anti-SIgA (but not with anti-IgG or anti-IgM) in Eustachian epithelial cells, and also in the subepithelial glands of tubal mucosa was present both before and after challenge. The results suggest that the middle ear mucosa is an immunoreactive site only after it has been activated with pathogens. In contrast, the tubal mucosa exhibits immunological activity also prior to the antigenic stimulation of present interest.

Animals↗
PubMed1992

HLA antigens and recurrent acute otitis media.

The frequencies of a number of HLA antigens were investigated in 45 individuals with clinical recurrent acute otitis media (rAOM), defined as six or more episodes of AOM during a 12-month period, and were compared to those in a control group from the same district. HLA-A2 was found to occur in 80% of the rAOM group, as compared to 55.9% of controls (p less than 0.01). HLA-A3 antigen occurred in only 11.1% of the rAOM group in contrast to 27.5% of controls (p less than 0.05). Among 22 prospectively followed children without any AOM during their first 3 years of life, the frequencies of HLA-A2 and HLA-A3 antigens were comparable with those among controls.

Acute Disease↗
PubMed1992

Occurrence of antibodies to pneumococcal protein antigens in experimental acute otitis media.

To study serological antibody response to pneumococcal protein antigens, experimental pneumococcal (type 3) acute otitis media (AOM) was induced in 6 rats, sera being analysed with the Western blot technique at different intervals after bacterial challenge. The most striking finding was a distinct antibody response to a protein of about 35 kDa visible in 5 of the rat sera within 14 days, and persisting throughout the remainder of the study (i.e., 56 days in all). Moreover, appear to be a phenomenon restricted to type 3 pneumococci. Both the pathogenetic importance of this protein and the immunological response it evokes are still unclear. However, as antibodies to protein antigens may contribute to inflammatory reactions in the middle ear (e.g., otitis media with effusion), this 35-kDa protein might be important for the development of sequelae to AOM.

Acute Disease↗
PubMed1992

Middle ear problems in childhood.

No single factor is as yet known which could be used to predict the possible development of rAOM in infants and children. However, some circumstantial evidence can be seen. Thus, an AOM début before the age of six months in a child with a family history of recurrent otitis indicates a clear risk of multiple recurrent episodes. Other 'intrinsic factors' speaking in favour of rAOM are low concentrations of specific IgG antibodies against pneumococcus type 6A in cord serum and a presence of the hereditary HLA-antigen A2 on the surfaces of white blood cells. Extrinsic factors' such as type of day-care, passive exposure to smoking at home and poor housing seem to increase the risk but do probably not constitute the definite cause of rAOM.

Age Factors↗
PubMed1991

HLA frequency in patients with recurrent acute otitis media.

Clinical data suggest the involvement of hereditary factors in children susceptible to recurrent acute otitis media. That relationships of varying degree exist between the frequencies of certain HLA antigens and various disease entities is well established. In the present study, we investigated the frequencies of a number of HLA antigens in 45 patients with clinical recurrent acute otitis media and compared these frequencies with those in a control group from the same district. The HLA-A2 antigen occurred in 80% (36/45) of the group with recurrent acute otitis media, as compared with 56% of controls. Of a subgroup of 11 children with recurrent acute otitis media who were prospectively followed up, 10 (91%) were HLA-A2 positive. The HLA-A3 antigen occurred in only 11% (5/45) of the group with recurrent acute otitis media as a whole (n = 45) in comparison with 28% of controls. Among 22 prospectively followed up children without any episode of acute otitis media during the first 3 years of life, the frequency of HLA-A2 was 45% (10/22) and that of HLA-A3, 32% (7/22). The results indicate the existence of a relationship between recurrent acute otitis media and the HLA-A locus, suggesting the involvement of genetic factors in the disease.

Acute Disease↗
PubMed1991

Western blot analysis of immunoglobulin G antibodies to pneumococcal protein antigens in healthy adults.

Using the Western Blot technique, sera from apparently healthy individuals were shown to contain antibodies against pneumococcal protein antigens of different molecular weights. A remarkable correlation was found to exist between the number of protein bands stained and the level of antibodies to type-specific carbohydrate antigens and C-polysaccharide. The findings suggest that the presence of antibodies against protein antigens reflects past infection with pneumococci.

Adult↗
PubMed1991

Serum antibodies against respiratory tract viruses in episodes of acute otitis media.

Although the findings of epidemiological studies have suggested viral respiratory tract infection (RTI) to be crucially involved in the development of acute otitis media (AOM), the relationship between AOM and viral RTI remains unclear. Serum samples, obtained in the acute and convalescent phases of 57 AOM episodes (in 35 children during the first three years of life) were analysed for IgG antibodies against influenza A viruses, influenza B viruses, parainfluenza virus type 1, respiratory syncytial virus and adenoviruses. One third of the AOM episodes (18/57) could be related to viral RTI, as evidenced by significant increases in viral serum antibody activity. Treatment failure occurred in four AOM episodes where increases in serum viral antibody activity were noted. In three of these failures, antibiotic treatment was unsuccessful despite the bacterial strains not being resistant to the drug used. This suggests that concomitant viral infection may be a determinant of treatment outcome in some AOM episodes.

Acute Disease↗
PubMed1991

High recovery of Haemophilus influenzae and group A streptococci in recurrent tonsillar infection or hypertrophy as compared with normal tonsils.

One hundred and twenty-six patients who underwent tonsillectomy because of recurrent acute tonsillitis, tonsillar hypertrophy or sleep apnoea were evaluated by tonsillar core culturing. The sleep apnoea patients served as controls, since none of them had tonsillar hypertrophy at ENT examination or any history of recurrent acute tonsillitis, and thus their tonsillar core flora could be regarded as normal. The isolation rate of H. influenzae was much lower among sleep apnoea controls (2.7 per cent) than among either the patients with recurrent acute tonsillitis (20.3 per cent) or those with tonsillar hypertrophy (36.7 per cent) (p less than 0.05), as was that of group A streptococci, 5.4 per cent versus 16.9 and 20 per cent, respectively (though the latter differences were not statistically significant). The isolation frequencies of B. catarrhalis, pneumococci, group C and G streptococci did not differ between the three groups. The high tonsillar core recovery rates of H. influenzae and group A streptococci both in patients with recurrent acute tonsillitis and in those with tonsillar hypertrophy, as compared with normal controls, suggests the possible involvement of these bacteria in both conditions.

Acute Disease↗
PubMed1991

Mucosal changes induced by experimental pneumococcal otitis media are prevented by penicillin V.

Penicillin V (pcV) was administered to 50 rats, either before bacterial challenge (prevention group), or after bacterial challenge but before fulminant purulent acute otitis media (AOM) was established (early treatment group). Five animals from each group were killed on days 4, 8, and 12, and 2 and 6 months after challenge. Middle ear mucosa was sampled at six different sites and studied in the light microscope. Untreated pneumococcal AOM in the rat has been shown to cause persistent structural changes of the middle ear mucosa. Both in the early treatment group and in the prevention group, the structural changes were diminished, as compared with those of untreated infected controls. The persistent structural changes seen after 6 months in untreated controls were not seen in animals that had received pcV in conjunction with the AOM episode. Though the beneficial effect on the mucosal changes during the first 2 weeks was more pronounced when pcV was given prophylactically, its use as early treatment would seem to be almost as effective in preventing the persistence of mucosal changes.

Acute Disease↗
PubMed1991

Experimental recurrent pneumococcal otitis media. Protection and serum antibodies.

To elucidate immune mechanisms in otitis media, middle ear infection was induced in 12 rats by intratympanic inoculation of Streptococcus pneumoniae type 3, either the ipsilateral or the contralateral middle ear being re-challenged 4 weeks later. Otomicroscopy inspection confirmed the presence of acute otitis media (AOM) in all rats after the first challenge. After re-challenge, protection against AOM was noted both in the ipsilateral and contralateral ears. Serum antibody concentrations increased after the initial challenge, reaching a maximum at 4-7 days, but had decreased to pre-immune levels at re-challenge, after which no new increase was noted. Serum IgG-antibodies to pneumococcal type 3-polysaccharide were triggered following the initial induction of unilateral pneumococcal AOM, but mucosal immune mechanisms are argued to be a more probable explanation of the ipsilateral protection seen after re-challenge.

Animals↗