Hannu Sarkkinen

C-reactive protein in respiratory virus infections

Les recherches effectuees chez 176 enfants atteints de diverses infections virales ont mis en evidence des taux de CRP superieurs a 40 mg/l et une leucocytose superieure a 15×10 9 /l dans la plupart des infections a adenovirus tandis que dans la plupart des infections a virus grippal, parainfluenza ou syncytial respiratoire, la CRP etait <40 mg/l et la leucocytose < a 15×10 9 /l, ce qui est typique des maladies virales et les oppose classiquement aux infections bacteriennes ou le taux serique de CRP est notablement eleve

Comparison of enzyme-immunoassay and radioimmunoassay for detection of human rotaviruses and adenoviruses from stool specimens

An enzyme-immunoassay (EIA) using polystyrene beads as the solid phase, guinea pig anti-rotavirus or anti-adenovirus immunoglobulin as primary antibody, rabbit anti-rotavirus or anti-adenovirus immunoglobulin as secondary antibody, and horseradish peroxidase-conjugated swine anti-rabbit immunoglobulin as indicator antibody, has been developed for the detection of human rotavirus and adenovirus antigens from stool specimens. A comparison of the developed EIA and radioimmunoassay (RIA) used previously in our laboratory was made with 250 stool specimens from children with acute gastroenteritis. Two specimens were found negative by both rotavirus and adenovirus EIAs but not by RIAs, but in each of these cases confirmatory EIA tests showed them to be false negatives. The confirmatory EIA tests were also necessary in several cases to prove the specificity of the binding or to eliminate non-specific reactions with specimens giving low positive reactions in EIA. The developed EIA was found to be as specific, sensitive and reliable as RIA in the routine diagnosis of rotavirus and adenovirus gastroenteritis provided that appropriate confirmatory tests were included.

Ureaplasma urealyticum infection associated with acute respiratory insufficiency and death in premature infants

The incidence and outcome of Ureaplasma urealyticum infection were studied in 98 infants born before 34 weeks of gestational age. Infection was defined as the presence of one or more isolations of U. urealyticum in samples obtained from trachea, blood, cerebrospinal fluid, or postmortem brain or lung biopsies. Forty-seven infants were infected. Intact amniotic membranes had no protective effect against infection; intrauterine U. urealyticum infection was detected in 19 infants who were born by cesarean section with intact amniotic membranes. Respiratory distress syndrome, the need for assisted ventilation, severe respiratory insufficiency, and death were significantly more common among infected than among noninfected infants. Our results suggest that U. urealyticum infection is associated with an unfavorable short-term outcome in preterm infants.

QUANTITATIVE ASPECTS OF ROTAVIRUS EXCRETION IN CHILDHOOD DIARRHOEA

ABSTRACT. Vesikari, T., Sarkkincn, H. K. and Mäki, M. (Department of Clinical Sciences, the University of Tampere, Tampere, Finland, and the Department of Virology, University of Turku, Turku, Finland). Quantitative aspects of rotavirus excretion in childhood diarrhoea. Acta Paediatr Scand 70:717,.–The amount of rotavirus (antigen) in diarrhoea! stools was determined from serially diluted faecal specimens using a solid phase radioimmunoassay (RIA) method. The acute stage RIA titres for rotavirus antigen ranged from 1:200 to 1:200000 with a mean titre of 1:2936 in a group of 16 infants with age range 2 to 14 months and 1:4 703 in a group of 12 children aged 25 to 94 months. In the younger age‐group the diarrhoea lasted longer (mean 7.8 days) than in the older children (mean 5.4 days) despite the fact that the quantity of rotavirus was similar. In most of the younger infants there was either no demonstrable rotavirus present at the time of cessation of diarrhoea, or the amount of virus was on the decrease. In contrast, among the older children there were cases with a high titre of rotavirus in the stools a few days after the diarrhoea had ceased. These children were considered as potential spreaders of rotavirus infection in the community. However, none of the long‐term follow‐up stool specimens, collected 28 to 47 days after the onset of diarrhoea, were positive for rotavirus RIA.

Rapid diagnosis of adenoviral tonsillitis: A prospective clinical study

Adenovirus antigen was detected by radioimmunoassay in the nasopharyngeal specimens of 30 of 74 children with febrile exudative tonsillitis. In the other 44 children, the cause of tonsillitis was identified in 16 (beta-hemolytic streptococci or Epstein-Barr, parainfluenza, or herpes simplex viruses). The clinical picture of adenoviral tonsillitis was difficult to differentiate from that of streptococcal disease; 20 of the patients had originally been given antibiotics. In 68% of patients without complications, the serum concentration of C-reactive protein was less than 20 mg/L, suggesting a viral disease. No other hematologic test was found helpful in identifying the adenoviral tonsillitis. The rapid detection of adenovirus antigen permitted withdrawal of unnecessary and ineffective antibiotic treatment in most patients.

Local IgA-class antibodies against respiratory viruses in middle ear and nasopharyngeal secretions of children with secretory otitis media.

The presence of antibodies against some important respiratory viruses in the middle ear and nasopharyngeal secretions of 52 children with secretory otitis media (SOM) was investigated in order to find out about the role of these viruses in the development of SOM.The method employed was a sensitive radioimmunoassay test.

DEMONSTRATION OF VIRAL ANTIGENS IN MIDDLE EAR SECRETIONS OF CHILDREN WITH ACUTE OTITIS MEDIA

Bacteria, particularly Diplococcus pneumoniae and Haemophilus influenzae, are often isolated from middle ear secretions of children with acute otitis media. However, in about 30 % of the cases middle ear secretion is bacteriologically sterile or contains non-pathogenic bacteria ( 1 ) . Since a majority of the upper respiratory infections are caused by viruses, it is logical to expect that viruses also cause otitis media. However, virological studies have usually yielded negative results and viruses have infrequently been isolated from middle ear secretions (2). One reason for this failure might be the relative insensitivity of the virus isolation techniques used. Therefore, development of immunofluorescence (IF) (3) and sensitive radioimmunoassay (RIA) and enzyme-immunoassay (EIA) techniques (4, 5, 6) for direct detection of viral antigens in clinical specimens offers new means of studying the viral etiology of acute otitis media. Middle ear secretions were collected from 84 patients with acute otitis media (50 boys and 34 girls, men age 3 years 6 months) during the 1979 and 1980 epidemics of respiratory infections. The secretions were processed and tested by RIA (all 84 secretions) and by IF (58 secretions) for adenovirus, influenza A and B virus, parainfluenza virus type 1 , 2, and 3, and respiratory syncytial virus (RSV) antigens (4). Bacteriological cultivations were carried out according to routine techniques. Altogether 7 out of 84 (8.3 %) of the patients had detectable viral antigens in their middle ear secretions (Table I) . Four secretions were positive by IF, and all 7 by RIA. Five of these 7 virus positive cases were bacteriologically studied, and Haemophilus influenzae was isolated in 3 cases. Two patients had negative bacterial isolations but they had been treated with antibiotics (either azidocillin or sulphamethoxazole-trimethoprim combination) before the secretions were collected. The epidemiology of respiratory infections during the study was closely related to these findings. In 1979, RSV and parainfluenza type 3 infections were continuously detected. The 1980 winter was characterized by a continuous

Generation of cell-mediated cytotoxicity against bovine-papilloma-virus-transformed primary mouse cell lines

SummaryThe immunogenicity and immunosensitivity of primary mouse cell lines transformed by bovine papilloma virus 1 (BPV1) DNA were studied in a syngeneic mouse model by determining cell-mediated cytotoxicity in the spleens of mice immunized with the transformed cells. One of the cell lines induced the generation of cell-line-specific Thy1.2-positive cytotoxic effector cells. However, most of the cell lines tested induced the generation of Thy1.2-positive effector cells, which in addition to BPV1-transformed cells were able to lyse a syngeneic cell line transformed by methylcholanthrene. The lysis of BPV1- and methylcholanthrene-transformed cell lines was mediated by recognition of the same antigenic determinants expressed on these cells, and all the BPV1-transformed cell lines were sensitive to lysis by these nonspecific effector cells of the lymphokine-activated killer (LAK) type.

Tumorigenicity and H-2 expression of papillomavirus-transformed mouse cell lines

SummaryTumorigenicity in immunocompetent syngeneic mice and H-2 class I antigen expression of BPV1-transformed mouse cell lines had no correlation. H-2 expression was examined using monoclonal anti-(H-2Kb) and anti-(H-2Db) antibodies in immunofluorescence staining for flow cytometry analysis and by determining the sensitivity of the cells to cytolysis by allostimulated spleen cells. Nontumorigenic cell lines were as resistant as tumorigenic cell lines to natural killer activity. The results indicate that in our model defence by natural killer cells is not a decisive factor. The results also show that instead of or in addition to H-2 class I antigens other factors (e. g. the presence or absence of virus-specific antigens) are important in determining the tumorigenicity of BPV1-transformed cell lines.

Clinical evaluation of radioimmunoassay of nasopharyngeal secretions and serology for diagnosis of viral infections in children hospitalized for respiratory infections

Viral diagnosis was performed using radioimmunoassay (RIA) for virus antigen in nasopharyngeal secretions (NPS) and complement-fixation (CF) tests of paired sera from specimens of 90 children hospitalized for acute respiratory infection. Major respiratory viruses sought for by both methods (adenoviruses, influenza A and B viruses, parainfluenza virus type 3, respiratory syncytial virus) were detected in 40 (44%) of the patients; 15% of the diagnoses were made by NPS-RIA alone. Serologic diagnosis of other viral infections was confirmed in six additional cases. In the different clinical entities a viral diagnosis was established as follows: pneumonia, 50%; upper or middle respiratory infection with no wheezing, 43%; acute laryngitis, 54%; and wheezing bronchitis, 29%. In each clinical entity the virus-positive and virus-negative patients had similar total leukocyte counts, mean C-reactive protein levels and mean erythrocyte sedimentation rates. There was no difference in the duration of hospitalization between the patients with positive and negative viral studies. It was not possible to divide the patients into clinical subgroups according to the presence or absence of detectable viral infection.