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Biomedical subjects

O Ruuskanen

Publications and source records attributed to O Ruuskanen.

At least 73 records · Page 4Linked to original sources
PubMed1996

Longitudinal analysis of human salivary immunoglobulins, nonimmune antimicrobial agents, and microflora after tonsillectomy.

In order to study the role of tonsils in the host defense in the oral region one pre- and two postoperative (1 and 6 months) whole saliva samples were collected from 25 young adults referred for tonsillectomy. Saliva samples were analyzed for selected host defense factors, representing both immune (total IgA, IgG, IgM, anti-Streptococcus mutans, anti-EBV, anti-CMV, and anti-adenovirus IgA and IgG) and nonimmunoglobulin (lysozyme, lactoferrin, salivary peroxidases, thiocyanate, hypothiocyanite, and agglutinins) mediators. Following tonsillectomy, a significant (P < 0.04) reduction was observed in specific IgG antibodies, suggesting that tonsils participate in local IgG response to oral antigens. Total IgM levels also decreased (P< 0.006), which may to some extent reflect reduced antigenic stimuli compared to preoperative status with frequent tonsillitis. Saliva-derived nonimmunoglobulin host defense factors, except lactoferrin, which declined significantly, remained normal throughout the study period. Our study indicates that tonsils play a role in local oral IgG-mediated immune response but tonsillectomy does not seem to lead to any significant long-term impairment of salivary defense capacity.

Adolescent↗
PubMed1996

Detection of Bordetella pertussis by polymerase chain reaction and culture in the nasopharynx of erythromycin-treated infants with pertussis.

BACKGROUND: Pertussis is a highly contagious respiratory disease and the most serious effects occur in young infants. Recently it has been shown that rapid and highly specific PCR can be a useful diagnostic tool for detection of pertussis infection. To our knowledge there are no previous studies concerning the disappearance of Bordetella pertussis DNA from the nasopharynx during antimicrobial treatment. METHODS: We studied prospectively how rapidly live B. pertussis organisms and DNA of these bacteria disappear from the nasopharynx during erythromycin therapy in unvaccinated infants. Eighty-five nasopharyngeal swabs obtained from nine erythromycin-treated infants with pertussis on consecutive days during hospitalization were tested by PCR and culture. The PCR products were further analyzed by Southern hybridization. RESULTS: On the fourth day of treatment 56% of the samples were positive by culture and 89% by PCR, whereas after 7 days the rates were 0 and 56%, respectively. In seven of nine patients PCR remained positive for 1 to 7 days longer than culture. The follow-up study also showed the semiquantitative nature of the PCR assay. The intensity of the PCR products in agarose gel usually weakened with time during erythromycin therapy. CONCLUSIONS: The results of this study show that PCR assay can achieve the specific diagnosis of pertussis infection in a large proportion of infants even when antimicrobial treatment has killed the organisms and culture is no longer positive.

Bacteriological Techniques↗
PubMed1996

Identification of enteroviruses in clinical specimens by competitive PCR followed by genetic typing using sequence analysis.

A sensitive method based on competitive PCR was developed to detect and quantitate enteroviral RNA in clinical specimens, with special emphasis on controlling contamination and the presence of potential inhibitory factors in the specimens. Oligonucleotide primers from the conserved parts of the 5' untranslated and VP2 capsid protein-coding regions were selected to differentiate between enteroviruses and rhinoviruses on the basis of the length of the cDNA amplicons. RNA transcribed from a truncated cDNA copy of the echovirus 11 genome was used as an internal control for the reverse transcription reaction and PCR. This allowed simple differentiation of the control and viral PCR products from each other by agarose gel electrophoresis and nonradioactive quantitation of the viral RNA in the clinical specimens. By direct sequencing of the PCR products and subsequent computer analysis of the data, potential laboratory contaminations could be monitored and enteroviruses from clinical samples could be grouped into four distinct clusters, thus enabling genetic typing of the viruses. The described method can be applied to the diagnosis and epidemiology of enteroviral infections.

Base Sequence↗
PubMed1996

New prospects in the prevention of otitis media.

Otitis media is the most common bacterial infection in children, accounting for a substantial economic burden to the health care system. Together with concern for long-term developmental sequelae, prevention of otitis media has become a high priority area of research. A wide range of factors has been associated with an increased risk of acute otitis media. Most of these factors, however, predispose to upper respiratory tract infection which, in turn, can be considered the most important risk factor for acute otitis media. Conventionally, antimicrobial prophylaxis, tympanostomy tubes and adenoidectomy have been used for prevention of otitis media. At present, the vaccine approach seems to hold the greatest promise for ultimate prevention of otitis media. In addition to the bacterial vaccines, vaccines against the most common viruses predisposing to acute otitis media may also prove valuable in the prevention of otitis media.

Adenoidectomy↗
PubMed1995

Signs and symptoms predicting acute otitis media.

OBJECTIVE: To determine whether acute otitis media can be distinguished from an uncomplicated upper respiratory tract infection by the symptoms of the children. DESIGN: Prospective cohort study. SETTING: Urban, pediatric primary care center in Turku, Finland. PATIENTS: Three hundred two children younger than 4 years (mean age, 2.1 years) attending day-care centers were followed up and examined during episodes of upper respiratory tract infection. The signs and symptoms of the children were recorded daily by the parents. MAIN RESULTS: The specificity and positive predictive value of earache for acute otitis media were 92% and 83%, respectively. However, 40% of the children with acute otitis media had no apparent earache. Restless sleeping had a specificity of 51% and a positive predictive value of 46% for acute otitis media. Thirty-one percent of the children with acute otitis media had no fever. Continuation of respiratory symptoms for several days after the first examination was significantly related with later development of acute otitis media. CONCLUSIONS: Earache in children with upper respiratory tract infection is indicative of acute otitis media, but the absence of earache does not preclude acute otitis media. Therefore, even in the absence of any signs and symptoms localized to the ear, all children at risk for acute otitis media should be examined during upper respiratory tract infection, and if respiratory symptoms persist for several days after the initial visit, a reexamination should be performed. Restless sleeping and fever are of no value in distinguishing acute otitis media from an uncomplicated upper respiratory tract infection.

Acute Disease↗
PubMed1995

Experimental myocarditis induced by two different coxsackievirus B3 variants: aspects of pathogenesis and comparison of diagnostic methods.

The ability of two coxsackievirus B3 (CBV3) variants to induce myocarditis in BALB/c mice was studied and plaque-forming assay, polymerase chain reaction (PCR), in situ hybridization, and immunohistochemistry were compared for detecting viruses and viral components in the myocardium. The virological findings were related to histopathologic and ultrastructural changes in the myocardium. CBV3-W induced severe myocarditis characterized by massive myocyte necrosis. Widely distributed myocyte damage clearly preceded modest inflammatory infiltrates in the myocardium. In contrast, CBV3-M1 induced mild myocardial injury. Both variants caused fulminant pancreatitis with nearly complete necrosis of the exocrine pancreas. CBV3 RNA was identified by PCR in the myocardium of CBV3-W-infected mice until the end of the follow-up period of 14 days. Moreover, semiquantitative results were obtained when the PCR/hybridization results were analyzed by a phosphor imaging system. Immunohistochemistry and in situ hybridization from formaldehyde-fixed, paraffin-embedded specimens were highly similar in detecting viral components during the early stages of the myocardial injury. The results indicate that: (i) direct viral damage plays an essential role in acute murine CBV3-induced myocarditis, (ii) PCR appears a useful and sensitive diagnostic method in acute myocarditis, and (iii) immunohistochemistry as a specific and relatively rapid method might be practicable also in studying the early stages of acute myocarditis from archival clinical material.

Acute Disease↗
PubMed1995

Respiratory syncytial virus--is it preventable?

Respiratory syncytial virus infection spreads readily among hospital wards, nurseries and intensive care units. Careful handwashing is the cornerstone in the prevention of nosocomial transmission. Use of rapid diagnostic tests permits the cohorting of patients and staff which has been shown to limit the spread in hospital wards. In addition, the use of gowns and gloves and limiting visitors have been recommended. In the future passive immunization with respiratory syncytial virus (RSV) immune globulin or RSV vaccination may be helpful in high risk patients.

Adult↗
PubMed1995

Short-term use of amoxicillin-clavulanate during upper respiratory tract infection for prevention of acute otitis media.

We performed a randomized, double-blind, placebo-controlled study to determine whether acute otitis media could be prevented by antibiotic therapy initiated promptly after the appearance of symptoms of upper respiratory tract infection. One hundred four children aged 1 to 4 years received a 7-day course of either amoxicillin-clavulanate or placebo. Acute otitis media developed in 9 (18%) of the 50 children receiving amoxicillin clavulanate and in 12 (22%) of the 54 children receiving placebo (p = 0.59).

Acute Disease↗
PubMed1995

Respiratory virus infections during anticancer treatment in children.

To evaluate the occurrence and clinical significance of respiratory virus infections in children during anticancer treatment, we studied 75 consecutive episodes of febrile infection in 32 children during 17 months. Viral antigen detection for 7 respiratory viruses, viral culture for rhinoviruses and enzyme immunoassay serology were used. Evidence for respiratory virus infection was found in 28 (37%) cases. Rhinovirus was the most common virus detected in 13 (17%) episodes. The other etiologic agents were respiratory syncytial virus (6 episodes), parainfluenza virus type 3 (5 episodes), adenovirus (4 episodes), influenza A virus (3 episodes), and influenza B virus (1 episode). Respiratory virus infections were diagnosed as often in leukopenic as in non-leukopenic patients (37% vs. 38%). In 4 cases bacteremic infection was diagnosed. We found no difference in serum C-reactive protein values when episodes positive for respiratory viruses were compared with virus-negative episodes. Our observations show that respiratory virus infections are common in febrile children receiving anticancer treatment. Diagnostic tests for respiratory viruses should be used more often in evaluation of fever in these patients.

Adolescent↗
PubMed1995

Incidence of acute otitis media associated with group A and B respiratory syncytial virus infections.

The comparative association of respiratory syncytial virus group A and B infections with acute otitis media was determined by analysing the hospital records of children with community-acquired respiratory syncytial virus infection during three successive outbreaks from 1987 to 1992. Of 326 episodes analysed, 192 (59%) were caused by group A and 134 (41%) by group B infections. Acute otitis media was diagnosed in 101 (75%) children with group B infection, compared with 119 (62%) with group A infection (p = 0.01). Group A infections were more often associated with wheezing (71% versus 59% in group B; p = 0.02) and oxygen therapy in inpatients (48% versus 31%, respectively; p = 0.008). The higher incidence of acute otitis media associated with group B infections was observed both after adjustment for potential confounding variables and during each outbreak.

Acute Disease↗
PubMed1995

Interleukin-1 alpha mediates the enhanced expression of intercellular adhesion molecule-1 in pulmonary epithelial cells infected with respiratory syncytial virus.

The mechanisms of virus-induced enhancement of intercellular adhesion molecule-1 (ICAM-1) expression in epithelial cells are unknown. In the present study, the effect of respiratory syncytial virus (RSV) infection on the expression of ICAM-1 in human pulmonary type II-like epithelial (A549) cells was evaluated. Conditioned RSV media (cRSV) produced from growth of RSV in A549 cells induced a significant increase in the expression of ICAM-1. Treatment of the cells with noninfectious cRSV prepared by ultraviolet (UV) irradiation (UV-cRSV) or ribavirin treatment resulted in the expression of ICAM-1 to a similar extent as infectious cRSV. These results suggested that RSV induces the synthesis of a soluble mediator(s) that regulates the expression of ICAM-1. Cytokine analysis by immunoassay and polymerase chain reaction showed that RSV induces the synthesis of interleukin (IL)-1 alpha and -beta, and tumor necrosis factor alpha (TNF-alpha). Preincubation of UV-cRSV with soluble IL-1 receptor (sIL-1r) almost completely blocked the enhancement of ICAM-1 expression. Furthermore, simultaneous incubation of infectious purified RSV with sIL-1r resulted in a significant reduction in enhancement of ICAM-1 expression. Preincubation with neutralizing antibodies to IL-1 alpha and -beta, and TNF-alpha showed that the predominant ICAM-1 enhancing soluble mediator in UV-cRSV was IL-1 alpha. These experiments provide direct evidence for an autocrine mechanism of enhanced ICAM-1 expression in RSV-infected epithelial cells that is mediated primarily by IL-1 alpha. Pulmonary epithelial cells may play an important immunoregulatory role in the microenvironment of the lower respiratory tract infected with RSV.

Cell Adhesion↗
PubMed1994

Salivary defense factors and oral health in patients with common variable immunodeficiency.

Studies of oral health in patients with common variable immunodeficiency have given controversial results. Obviously, one major factor modifying the oral health of these patients is saliva, in which the antibody-mediated defense is remarkably impaired compared to that of healthy subjects. However, the occurrence of nonimmunoglobulin (innate) antimicrobial agents in saliva of these patients is virtually unknown. Therefore, we analyzed both immune (total IgA, IgG, IgM, anti-Streptococcus mutans IgA, IgG, and IgM antibodies) and nonimmune (lysozyme, lactoferrin, salivary peroxidase, myeloperoxidase, hypothiocyanite, thiocyanate, and agglutinins) factors in whole saliva of 15 patients with common variable immunodeficiency. All patients were on Ig-replacement therapy (median duration, 10 years; range, 2-25 years), which had normalized their IgG but not their IgA or IgM levels both in serum and in saliva. Also, comprehensive clinical and microbiological analyses were made. The control group comprised 15 age- and sex-matched immunologically healthy subjects. The results showed no notable differences in dental caries, periodontal diseases, or salivary microorganisms but the patients had a history of more frequent oral mucosal lesions and respiratory infections. All innate, nonimmune salivary defense factors were equally abundant in the patients as in the controls, in many cases even at somewhat higher concentrations. These findings suggest that in spite of immunodeficiency, patients with common variable immunodeficiency display normal, perhaps even slightly elevated, levels of nonimmunoglobulin defense factors in whole saliva.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Antibodies to filamentous hemagglutinin of Bordetella pertussis and protection against whooping cough in schoolchildren.

A pertussis outbreak was studied prospectively in an elementary school with 39 pupils. All had been immunized with at least three doses of Finnish diphtheria-tetanus toxoid-pertussis vaccine. Diagnosis of pertussis was based on culture, polymerase chain reaction results, and EIA serology using filamentous hemagglutinin (FHA), pertussis toxin, and 69-kDa outer membrane protein as antigens. At the first sampling, 21 children had symptoms suggestive of pertussis, and 18 were healthy. Of the latter, 8 remained healthy without any antibiotic treatment and 9 developed clinical pertussis 1-22 days later. One child developed cough later, but this symptom did not meet criteria for pertussis. The mean levels of IgG, IgM, and IgA antibodies to FHA were significantly higher in 8 healthy children than in 9 children who developed pertussis after the first sampling (P < .001, P = .027, and P = .011, respectively). The results show that antibodies to FHA of Bordetella pertussis in immunized schoolchildren correlate with protection against pertussis.

Adhesins, Bacterial↗