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Biomedical subjects

K Prellner

Publications and source records attributed to K Prellner.

At least 109 records · Page 6Linked to original sources

Prophylactic effect of human immunoglobulin against pneumococcal post-splenectomy sepsis in the rat.

Failure to clear the blood of pneumococci after splenectomy may be corrected by active immunization, but some patients show poor antibody response to pneumococcal vaccination. Long-term antibiotic prophylaxis against post-splenectomy sepsis carries the risk of development of bacterial resistance and low patient compliance. In the present study, using a rat model for post-splenectomy sepsis, human immunoglobulin was given 24 h before challenging the animals with 10(3) Streptococcus pneumoniae. Immunoglobulin at a dosage of 300 mg/kg body weight was protective. Reducing the immunoglobulin dose to 75 mg/kg did not alter the mortality rate but significantly prolonged the survival time. The results indicate that the new immunoglobulin preparations for intravenous use might provide an effective means of reducing the risk of post-splenectomy sepsis, even in the most susceptible patients.

Animals↗

Experimental recurrent otitis media induced by Haemophilus influenzae: protection and serum antibodies.

PURPOSE: To study whether acute otitis media caused by encapsulated or nontypeable Haemophilus influenzae confers cross-reactive protective immunity in an animal model system and to explore the possible involvement of various humoral specific antibodies in protection. MATERIALS AND METHODS: Rats were intrabullarly challenged with H influenzae type b and two different nontypeable H influenzae strains. One month after the initial infection, the animals were rechallenged ipsilaterally or contralaterally with either a homologous or heterologous strain, and the susceptibility to reinfection was investigated by otomicroscopy. RESULTS: The animals challenged and rechallenged with the type b strain were well-protected ipsilaterally and contralaterally, while the protection after homologous rechallenge with a nontypeable strain was partial in the ipsilateral ear and very poor in the contralateral ear. Middle ears previously infected with a nontypeable strain remained fully susceptible to infections with heterologous strains, but there was an indication of cross-protection in the animal groups where the first episode of acute otitis media was caused by type b and the second by a nontypeable strain. Using the Western blot technique and an enzyme linked immunosorbant assay, the serological response to different outer membrane proteins, especially protein D, of H influenzae during and after middle ear infection were investigated. The serological response from the type b infected animals were generally more distinct, while the antibody levels against protein D were lower in these groups compared with the groups infected with nontypeable strains. CONCLUSIONS: These data indicate that H influenzae type-b-induced experimental otitis media results in a better protection than a nontypeable-induced, and H influenzae b confers a cross protection.

Animals↗

Antibody activity of IgG subclasses against pneumococcal polysaccharides after vaccination.

The isotypic pattern of antipneumococcal polysaccharide antibodies with respect to IgG subclasses differs in adults and children. Adults show almost exclusively IgG2 activity, whereas children exhibit both IgG1 and IgG2 activity. The IgG subclass pattern of the antibody response after pneumococcal vaccination was evaluated in nine healthy children 1 to 2 years of age, eight healthy children 5 to 6 years old, and eight healthy adults. The number of individuals responding increased with age, and the response was mainly of the IgG1 subclass. The implications of this finding are discussed.

Adult↗

A rat model for pneumococcal otitis media.

The middle ears of 29 male Sprague-Dawley rats were injected with viable pneumococci, type 3 or 6A, and changes were monitored by otomicroscopy and analysis of bacterial samples from middle ear effusions, blood, and the nasopharynx. Depending on the type of pneumococci and its concentration, three responses were noted: otitis media with purulent effusion, otitis media with serous effusion, or no reaction. The mortality rate was low and the animals recovered without permanent deterioration or otomicroscopically discernable change. The results of this study show the rat to be a suitable animal model for the study of bacterial otitis media.

Animals↗

Respiratory tract infections in children with recurrent episodes as preschoolers.

The occurrence of respiratory tract infections (RTI) in 41 school-age children, who had recurrent RTIs treated with antibiotics as preschoolers, was followed prospectively for two years through diary reports by parents and medical consultations, and compared with that in 29 children of the same age and socio-economic background, who had few or no such infections as preschoolers. During the two-year follow-up, a greater number of episodes of RTI and a longer mean duration of such episodes were reported in the diaries concerning the children with recurrent bacterial RTIs as preschoolers compared with the controls (p less than 0.01). The annual incidence of bacterial RTI from birth onwards decreased with age among the children with recurrent episodes as preschoolers, unlike in the control group, where the incidence remained consistently low, the difference in incidence being significant up to the age of eight years (p less than 0.01). Acute otitis media was the predominant bacterial RTI in preschoolers, and acute tonsillitis in school-age children. There was a tendency toward a greater incidence of other types of disease and complications/sequelae of infections among the RTI-afflicted group than among the controls, both as preschoolers and as school children. Our findings suggest that certain children constitute a group with high morbidity, susceptible to RTIs and other illnesses over a rather long period of years.

Adolescent↗

Children with recurrent respiratory tract infections tend to belong to families with health problems.

Children (7-11 years of age) who had recurrent respiratory tract infections (RTI) treated with antibiotics as preschoolers (n = 41), and their families were compared with regard to medical and social factors to families with children of comparable age who had had no such infections as preschoolers, or only isolated episodes (controls; n = 29). All the children studied had attended day-care centres as preschoolers. The two groups of children did not differ with regard to socio-economic conditions or age at admission to day-care centres. There was a difference in the two groups with regard to signs noted at physical examination (p less than 0.05), eardrum changes being observed in 34% of the children with recurrent episodes of RTI as preschoolers and in none of the controls (p less than 0.001). Questionnaires answered by parents indicated diseases, particularly cardiovascular diseases, to be significantly more frequent in the families of the children with recurrent RTIs as preschoolers than in those of the controls (p less than 0.01). Parents of the controls were more often satisfied with their own health (p less than 0.05) and reported fewer symptoms of minor illness (p less than 0.05), as compared with parents of the children with recurrent RTIs as preschoolers. Thus, the results of the present study support the idea that children with recurrent bacterial RTIs as preschoolers tend to belong to families with health problems.

Anti-Bacterial Agents↗

Effects of active immunization with a pneumococcal surface protein (PspA) and of locally applied antibodies in experimental otitis media.

An experimental rat model for Streptococcus pneumoniae otitis media was used to investigate passive protection by anti-type 3 capsular antibodies and effects of immunization with pneumococcal surface protein A (PspA). Anti-type 3 antibodies instilled into the middle ear reduced purulent otitis media as compared to control animals (p = 0.015). Secondly, after immunization with PspA, the right middle ear was inoculated with S. pneumoniae type 6A in a dose calibrated to induce purulent otitis media. There was an anti-PspA antibody response in all rats immunized and a reduction in signs of purulent otitis media as compared to control animals (p = 0.026). Thus, purulent (acute) otitis media can be reduced by local application of antibodies in the middle ear and also by immunization with a non-type-specific pneumococcal protein, PspA.

Animals↗

Complement and C1q binding substances in otitis media.

Complement activation, as shown by increased amounts of complexes composed of C1r-C1s-C1 IA, and abnormal complexes of C1r-C1s were demonstrated in serum from patients with acute pneumococcal and chronic otitis media, serous or mucoid respectively. C1q binding substances were shown in middle ear effusions and in sera from patients with chronic serous otitis media. Presence of immune complexes and/or bacterial products capable of binding c1q results in formation of C1r-C1s-C1 IA complexes and may also cause the generation of C1r-C1s complexes. Such a dissociation of the C1 component will compromise the important opsonic function of the classical pathway.

Acute Disease↗

Immune complexes and complement in serous and mucoid otitis media.

The occurrence and quantity of immune complexes in middle ear effusion (MEE) and serum, as well as serum levels of complement (C) factors were investigated in patients with chronic otitis media. Immune complexes were demonstrated in 85% of the serous MEE and in 28% of the sera. Depressed Clq values and presence of abnormal complexes, composed of subcomponents of the first C factor, indicated a disturbed function of the C system. Activation of C by the classical pathway was demonstrated in 23% of the patients. Decreased levels of properdin were also noted. The disorders within the C system tended to normalize as the otitis subsided.

Antigen-Antibody Complex↗

Complement aberrations in serum from children with otitis due to S. pneumoniae or H. influenzae.

Complement components C1q, C1s, C3, C4, factor B and properdin were measured, together with C1 subcomponent complexes and Cq binding substances in acute and convalescent samples from patients with relapsing and non-relapsing otitis media due to S. pneumoniae and H. influenzae. Analysis of C1 subcomponent complexes together with the finding of low C1q levels gave evidence of a disturbed C1 function in acute OME. Furthermore, complement activation by the classical and by the alternative pathways was demonstrated. Complement aberrations were more pronounced in relapsing otitis than in non-relapsing otitis. C1q binding substances that might possibly cause the complement aberrations found were present in most of the patients.

Acute Disease↗

Nasopharyngeal carriage of bacteria in otitis-prone and non-otitis-prone children in day-care centres.

During a 2-year period nasopharyngeal specimens were taken monthly on scheduled occasions as well as at episodes of acute otitis media (AOM) from a population of children attending day-care centres. The carriage rates of pneumococci, Haemophilus influenzae and Branhamella catarrhalis in 26 otitis-prone (OP) children when asymptomatic and at episodes of AOM were compared with the carriage rates in 36 non-otitis-prone (NOP) children. Pneumococci, H. influenzae and B. catarrhalis were found as frequently in NOP as in asymptomatic OP children. At AOM episodes only B. catarrhalis was found significantly more often than in the scheduled cultures. The frequencies of the six most commonly isolated pneumococcal types/groups (6, 23, 19, 14, 11, 18) were similar in the cultures taken from NOP and OP children on scheduled occasions as well as in cultures taken at AOM episodes. In contrast to the NOP children H. influenzae and B. catarrhalis were isolated less frequently in the 3-4-year-old than in the 2-3-year-old asymptomatic OP children. Our data indicated that the presence of pneumococci, H. influenzae or B. catarrhalis in the nasopharynx does not per se increase the risk for the development of AOM.

Acute Disease↗

A longitudinal study of the nasopharyngeal carriage of pneumococci as related to pneumococcal vaccination in children attending day-care centres.

A long-term study of nasopharyngeal carriership in 405 children, aged 6 months to 5 years, attending day-care centres was performed. The effect of pneumococcal vaccination was evaluated in a double-blind investigation where the children received either Pneumovax (a 14-valent pneumococcal vaccine) or saline. Nasopharyngeal cultures were taken monthly by a trained nurse during a 2-year follow-up period. No difference in pneumococcal carriage was found between vaccinees and controls. Pneumococci were found in 31.9% of all cultures. In day-care centres attended by greater than or equal to 45 children the carriage rate of pneumococci was significantly higher than in centres with less than 45 children. Spreading of pneumococci within day-care centres was common but rather short-lived. Children younger than 2 years showed the highest carriage rates. Pneumococci of group 6 were carried most frequently and for longer periods than groups 19 and 23.

Bacterial Vaccines↗

Antibody activity before and after pneumococcal vaccination of otitis-prone and non-otitis-prone children.

The antibody activity of the IgM class and subclasses of IgG and IgA against pneumococcal bacteria of types 3, 6A and 19F was studied before and after administration of a pneumococcal vaccine (Pneumovax) in a group of children with recurrent acute otitis media (rAOM) and in groups of non-otitis-prone children. Only occasionally was there a significant rise in antibody activity after vaccination in any of the groups. There was no difference in the response to vaccination between rAOM children and healthy children. However, rAOM children exhibited lower antibody activities in most Ig subclasses against pneumococcus type 6A--a common causative agent in AOM--before as well as after vaccination compared with the healthy children. The results indicate that the response to vaccination is equally poor in all children, irrespective of whether they have a history of frequent attacks of acute otitis media, but, in contrast to healthy children, the rAOM children seem to have an inability to mobilize antibodies in response to infections with some pneumococcal types.

Antibodies, Bacterial↗

Acute mastoiditis. Influence of antibiotic treatment on the bacterial spectrum.

The work was undertaken to investigate the spectrum of bacteria responsible for acute mastoiditis and to find out whether it is affected by intake of antibiotics prior to surgical treatment. The records were reviewed of 22 children with acute mastoiditis in whom mastoidectomy had been performed and bacterial cultures obtained. Eleven of the patients had had antibiotic treatment prior to admission (9 penicillin V and 2 erythromycin). Streptococcus pneumoniae was found in 8 of the purulent discharges: Haemophilus influenzae, Streptococcus beta-hemolyticus and Staphylococcus aureus in 2 each; Proteus mirabilis, Pseudomonas pyocyaneus and a Bacteroides strain in 1 each, while five discharges-all from patients pretreated with antibiotics-yielded no growth. None of the 9 patients pretreated with penicillin V provided pure cultures of pneumococci or beta-hemolytic streptococci, while one or the other of these species was found in 8 of the 11 untreated patients. Gram-negative bacteria were found both among those with and those without antibiotic pretreatment. The data indicate that pneumococci and beta-hemolytic streptococci are more likely to cause mastoiditis than are the other pathogens found in acute otitis media, and that, when drained at operation, purulent discharges are often found to have been sterilized by the pre-operative antibiotic treatment.

Acute Disease↗

Clinical and laboratory findings in patients with acute tonsillitis.

In 82 patients with acute tonsillitis studied, beta-hemolytic group A streptococci were isolated from 30 (37%), and group C or G streptococci from 12 (15%). In the 40 patients with non-streptococcal tonsillitis there was a significantly higher isolation rate of pneumococci, H. influenzae and/or B. catarrhalis, as compared with those with beta-hemolytic streptococci. Patients were classified regarding clinical status according to standardized criteria as severe, moderate, or mild. The patients with group A streptococcal tonsillitis were significantly more often classified clinically as 'severe' and had significantly shorter duration of symptoms before seeking medical care, as compared with those with non-streptococcal tonsillitis. Significant increases in white blood cell count and in anti-DNase B were found in the patients with group A streptococcal tonsillitis, whereas their antistreptolysin O levels did not increase significantly. C-reactive protein concentrations were consistently higher in the patients with group A streptococcal tonsillitis. No evidence of polyclonal beta-lymphocyte stimulation was found when measuring antibodies against pneumococci and group B streptococci. The findings show clinical and simple laboratory tests to be useful aids in distinguishing group A streptococcal tonsillitis from non-streptococcal tonsillitis, and that other bacteria may be involved in non-streptococcal tonsillitis.

Acute Disease↗

Treatment failure in acute otitis media. A clinical study of children during their first three years of life.

Although little is known about the occurrence of treatment failure in acute otitis media (AOM), available data suggest that it may be over-diagnosed. In the present study the frequency of treatment failure in AOM was determined in 113 children followed for 3 years from birth. Of 300 AOM episodes, 293 (in 70 children) were treated with oral antibiotics, and children under 10-11 months of age usually underwent myringotomy as well. During the observation period, there were 22 instances (in 16 children) of failure to respond to the primary antibiotic treatment of the AOM episodes. The annual frequency of treatment failure was 18.5%, 4.5% and 4.2% during the first, second and third years of life, respectively. The risk of failure to respond to antibiotic treatment was greater during the first year of life than during the following 2 years. The bacteria isolated and the choice of drug seemed to be of secondary importance.

Acute Disease↗

Recurrent acute otitis media. A prospective study of children during the first three years of life.

To evaluate possible risk factors for developing recurrent acute otitis media (rAOM), 113 children were followed prospectively from birth to the age of 3 years. One of the aims was to determine whether such risk factors could be identified before the onset of the recurrences, so that optimal care and prophylactic measures could be made available at an early stage in such cases, on the basis of continuous follow-up by an ENT specialist. During the follow-up, 13 children developed rAOM, defined as six or more episodes of acute otitis media (AOM) during a 12-month period, 57 children had occasional episodes of AOM, and 43 children had no AOM at all. Of the children with onset of AOM before 6 months of age, 80% developed frequent episodes of AOM. The frequency of other respiratory tract infections and of family histories of otitis-proneness was higher among rAOM children than among the other children. The development of rAOM was unrelated to such factors as sex, familial history of allergy, duration of breast-feeding, or domestic environment. Nor could attendance at day-care centres be concluded as constituting a risk factor for the development of rAOM. An onset of AOM before 6 months of age was highly predictive of subsequent recurrent bouts of AOM, which emphasizes the importance of correct diagnosis in infants.

Acute Disease↗