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Biomedical subjects

P Halonen

Publications and source records attributed to P Halonen.

At least 91 records · Page 5Linked to original sources

Inclusion body myositis and paramyxoviruses.

Inclusion body myositis (IBM) is a distinct type of muscle disease. The characteristic electron microscopic findings, intranuclear or intracytoplasmic inclusions composed of microtubular filaments, morphologically resemble paramyxovirus nucleocapsids. These findings and the reported immunoreactivity of the inclusions with mumps virus antibodies have suggested that inclusion body myositis is a chronic virus infection. We analyzed skeletal muscle specimens from three patients with characteristic light microscopic features and electron microscopically verified inclusions of IBM by immunocytochemistry using antibodies raised against members of the paramyxovirus group, and by in situ hybridization with a cRNA probe representing the mumps virus nucleocapsid gene. The specificity of the reactions was demonstrated with infected and uninfected cultured cells. No immunocytochemical staining or hybridization signal was observed in biopsy specimens from IBM patients. These findings speak against a paramyxovirus etiology of IBM.

Aged↗

Treatment of acute exacerbations in early multiple sclerosis: cyclosporin A or prednisolone?

Twenty-six acute exacerbations in 26 patients with early definite multiple sclerosis (MS) were treated with oral cyclosporin-A (CyA) or oral prednisolone in a double-blind, controlled and randomized trial. The duration of the treatment was 6 weeks. All of the patients showed improvement during the treatment. There were no differences in outcome between patients on CyA (7.5 mg/kg) or prednisolone (decreasing doses from 0.8 mg/kg) during the 6 week treatment. However, the improvement of clinical signs 3 months after the treatment was slightly greater in the prednisolone group. The drugs did not have significant side-effects. There was no fluctuation in the CD4/CD8 ratio during the follow-up. The two treatment groups did not differ from each other in respect to the number of CD3 (T3), CD4 (T4), CD8 (T8), CD14 (monocytes), CD20 (B cells) or CD25 (interleukin-2 receptor positive cells). The number of active T cells with the interleukin-2 receptor was high in the beginning of the exacerbation but it decreased during the treatment. To conclude, the effects of CyA and prednisolone were comparable in the treatment of acute MS relapses.

Acute Disease↗

Recurrent wheezy bronchitis and viral respiratory infections.

Fifty four patients aged from 1 to 6 years who had had recurrent attacks of wheezy bronchitis were prospectively followed up for three months to find out if there was an association between different viral respiratory infections and episodes of wheezing. Of the 115 episodes of upper or lower respiratory tract symptoms, virus or Mycoplasma pneumoniae infection were diagnosed in 52 (45%). Thirty four of rhinoviruses. The patients had an average of 2.1 episodes of respiratory tract symptoms the total mean (SD) duration of which was 30 (2) days of the 92 days that followed. Wheezing occurred during 76 (66%) of the 115 episodes and during a third of these the patient was admitted to hospital because of severe dyspnoea. Wheezing started a mean (SD) of 43 (7) hours after the first symptoms of respiratory infection and persisted for 3.8 (4.2) days in patients in whom virus infection was diagnosed. The incidence of wheezing was not associated with IgE mediated atopy, with positive virological tests, or with fever during virus infection, but was associated with parental smoking and more than one sibling.

Bronchitis↗

Viral lower respiratory tract infections in Filipino children.

Viral causes of acute lower respiratory tract infection were studied prospectively between 15 June and 31 October 1984 in 312 Filipino children less than 5 years old living in periurban slums and middle-class housing. The cause was based on viral antigen detection, virus isolation, and antibody assays. There were 131 children (41.2%) who were admitted to the hospital, and 150 (47%) had an infiltrate on chest radiograph. A total of 198 viral infections were confirmed in 162 patients (51.9%), 42.3% with single viral infection and 9.6% with mixed (two or more) infection. The infections were measles (21.4%), influenza A (15.9%), parainfluenza types 1, 2, and 3 (8.8%), respiratory syncytial virus (7.1%), influenza B (5.8%), enteroviruses (5.1%), adenoviruses (3.9%), herpes simplex virus (1.6%), and cytomegalovirus (1.3%). Viral infections other than measles were seen in 39.7% of the cases. The presence of viral infection correlated with better nutritional status. Influenza A or B diagnosis was associated with mild forms of acute respiratory tract infection, measles and a preceding rash with severe disease.

Acute Disease↗

Prevalence of human rotavirus serotypes in some European countries 1981-1988.

An extended epidemiological survey on the circulation of the 4 established human rotavirus (HRV) serotypes in some European countries was carried out on 831 fecal strains collected from infants and young children with acute non-bacterial gastroenteritis during 1981-88. Typing was done by enzyme-linked immunosorbent assay and/or solid-phase immune electron microscopy using VP7 type-specific neutralizing monoclonal antibodies. Serotype 1 HRV strains were found to be largely predominant in this period both in Italy and other countries, whereas serotype 4 strains were less common. The number of strains of serotypes 1 and 4 circulating in Europe was equivalent only in 1983-84. Serotype 2 strains were significantly represented only in 1981-84, while strains of serotype 3 were nearly absent, since only 8 strains (2 of which belonged to subgroup I) were found during the entire study period. About 10% of strains could not be typed, while 9 strains exhibited dual VP7 reactivity and 6 were non-group A HRVs. These epidemiological findings must be taken into consideration when deciding strategies for preparing vaccines to be used in Europe.

Child, Preschool↗

[Negative and positive attitudes to EDP installation in Varkaus District Hospital].

This study was undertaken to describe the attitudes of the personnel of a hospital toward automatic data processing. We describe also the change in the attitudes during a four-year adp-system development. In 1984 123 persons were interviewed in Varkaus district hospital in Eastern Finland. The number of interviewed persons in the same hospital in 1988 was 125. During the four years the attitudes became more positive. Nearly all personnel groups changed their attitudes. Only the clerical staff on the wards had more negative attitudes in 1988 than in 1984. That was mostly due to ample amount of faults both in hardware and software at the time interviewing took place. That was even seen in the attitudes of the out-patient clinic personnel who had to work with the same problems. High level both in base and in data processing education had effect on positive attitudes.

Attitude to Computers↗

Coverage of public oral health services for young children in Finland.

In the Finnish programme of public oral health care for preschool children, every child is eligible for free care. The coverage of the programme has been high, about 85%. The aim of this study was to determine, whether the nonparticipants of the programme actually do have equality in making the choice to participate. The barriers to care were identified. All 4- to 6-year-old children who were registered administratively as nonparticipants in oral health care in 1981 and their randomly selected controls were studied in the city of Lahti. Detailed analysis of nonparticipation showed that some children had been misclassified as nonparticipants in the administrative statistics, indicating the national coverage of the programme to be higher than reported. Based on this finding, suggestions are made for increasing reliability of official statistics. Multiple logistic regression analysis for 36 factors resulted in three main barriers to utilization. Children of single-parent families in which the parent had a low level of education and difficulties to take time off work had the highest risk of nonutilization and thus had little choice to participate. Children with fear to dental care, regardless of any characteristic of the family or parents, were at increased risk of nonparticipation. Not having received the invitation to an examination also increased nonutilization, regardless of any factors related to family, parents or child. It was concluded, however, that these barriers to utilization could be manipulated by the system of public oral health care.

Attitude↗

Clinical role of respiratory virus infection in acute otitis media.

The clinical characteristics of acute otitis media in relation to coexisting respiratory virus infection were studied in a 1-year prospective study of 363 children with acute otitis media. Respiratory viruses were detected using virus isolation and virus antigen detection in nasopharyngeal specimens of 42% of the patients at the time of diagnosis. Rhinovirus (24%) and respiratory syncytial virus (13%) were the two most common viruses detected. Adenovirus, parainfluenza viruses, and coronavirus OC43 were found less frequently. The mean duration of preceding symptoms was 5.9 days before the diagnosis of acute otitis media. Ninety-four percent of the children had symptoms of upper respiratory tract infection. Fever was reported in 55% and earache in 47% of cases. Patients with respiratory syncytial virus infection had fever, cough, and vomiting significantly more often than patients with rhinovirus infection or virus-negative patients. No significant differences were found in the appearance of the tympanic membrane and outcome of illness between virus-negative and virus-positive patients with acute otitis. Most patients respond well to antimicrobial therapy despite the coexisting viral infection. If the symptoms of infection persist, they can be due to the underlying viral infection, and viral diagnostics preferably with rapid methods may be clinically useful in these patients.

Acute Disease↗

Immunoassay for serologic diagnosis of influenza type A using recombinant DNA produced nucleoprotein antigen and monoclonal antibody to human IgG.

Influenza type A nucleoprotein (NP) derived from the full length cloned gene expressed in E. coli was evaluated in a solid phase enzyme immunoassay (EIA) for detection of human antibody to influenza. Monoclonal antibody to human IgG was used for detection. Direct and indirect assays were developed and sera were tested in serial and single dilution formats. Preliminary results indicated that recombinant-and virion-derived NP antigens were comparable in binding ability to plastic and binding human antibody. Eighty-seven paired sera from influenza patients were tested. The most sensitive assay (indirect-serial dilution) detected 56 (64%) rises and the simplest assay (direct-single dilution) detected 43 (49%) rises, compared to 36 (41%) for complement fixation. Paired sera from 18 control patients showed no evidence of antibody rises by any of the assays. Forty-nine paired sera from influenza B infected patients were negative for antibody rises except for one borderline rise by the indirect-serial dilution assay. These results indicate that the use of recombinant DNA derived nucleoprotein for immunoassay is feasible. The sensitivity of immunoassays using NP adsorbed to the solid phase and monoclonal antibody specific for human IgG to detect bound antibody exceeded that of conventional complement fixation testing for establishing serologic evidence of influenza type A infection.

Antibodies, Monoclonal↗

One-incubation time-resolved fluoroimmunoassay based on monoclonal antibodies in detection of influenza A and B viruses directly in clinical specimens.

A new modified enzyme immunoassay screening method was developed for testing hybridoma cultures, so as to select antibodies useful for solid phase assays. Samples of hybridoma cultures were incubated for 1 h with purified nucleoprotein preparation in microtiter wells precoated with rabbit anti-influenza A or B immunoglobulin, followed by washing and addition of anti-mouse HRPO-conjugate. The monoclonal antibodies were then used in one-incubation time-resolved fluoroimmunoassay (TR-FIA) for detecting influenza viral proteins in nasopharyngeal aspirate specimens. The sample and europium (Eu)-labelled monoclonal detector antibody (100 microliter of each) were added simultaneously to microtiter wells precoated with anti-virus monoclonal antibody, and incubated for 1 h. After washing and addition of the enhancement solution the strips were shaken for 10 min before measurement of the fluorescence using a photon counting fluorometer. All of the monoclonal antibodies screened by our modified method and Eu-labelled worked as detector antibodies. Many of these monoclones also functioned as capture antibodies on solid phase. A total number of 309 (influenza A) and 104 (influenza B) nasopharyngeal aspirate specimens taken mainly from hospitalized children with acute respiratory disease were tested with the TR-FIA, using monoclonal antibodies produced by our modified screening method in comparison with monoclonal antibodies previously reported elsewhere (Walls et al., 1986). Results were similar, and superior to those obtained with routinely used indirect enzyme immunoassay based on polyclonal antibodies. The results of this study indicate that the one-incubation TR-FIA using monoclonal antibodies selected by the modified screening method is a highly sensitive and rapid method for detecting influenza A and influenza B virus in clinical specimens.

Antibodies, Monoclonal↗

Acute otitis media and respiratory virus infections.

We studied the association of acute otitis media with different respiratory virus infections in a pediatric department on the basis of epidemics between 1980 and 1985. Altogether 4524 cases of acute otitis media were diagnosed. The diagnosis was confirmed by tympanocentesis in 3332 ears. Respiratory virus infection was diagnosed during the same period in 989 patients by detecting viral antigen in nasopharyngeal mucus. There was a significant correlation between acute otitis media and respiratory virus epidemics, especially respiratory syncytial virus epidemics. There was no significant correlation between outbreaks of other respiratory viruses and acute otitis media. Acute otitis media was diagnosed in 57% of respiratory syncytial virus, 35% of influenza A virus, 33% of parainfluenza type 3 virus, 30% of adenovirus, 28% of parainfluenza type 1 virus, 18% of influenza B virus and 10% of parainfluenza type 2 virus infections. These observations show a clear association of respiratory virus infections with acute otitis media. In this study on hospitalized children Haemophilus influenzae strains were the most common bacteriologic pathogens in middle ear fluid, occurring in 19% of cases. Streptococcus pneumoniae was present in 16% and Branhamella catarrhalis in 7% of cases. There was no association between specific viruses and bacteria observed in this study.

Female↗

The role of parainfluenza viruses in inspiratory difficulties in children.

Viral findings were prospectively studied in middle and lower respiratory tract infections in 449 hospitalized children during a 12-month follow-up period. A viral aetiology was found in 30 of the 65 children (46%) with inspiratory difficulties. Parainfluenza viruses were the infective agents in 24 of the 30 cases with viral diagnoses (80%), type 2 being the most prominent. There were 38 cases of parainfluenza infections, type 2 being the infective agent in 58% of the 24 cases of parainfluenza infections with inspiratory difficulties but in only 21% of the 14 cases of parainfluenza infections without inspiratory difficulties. Type 2 parainfluenza virus produced inspiratory difficulties in 82% of the cases as opposed to 56 and 50% of the cases for type 1 and 3, respectively. It is concluded that the type 2 parainfluenza virus has a particular association with inspiratory difficulties in children. Viral diagnosis was reached using direct antigen detection in nasopharyngeal specimens by radioimmunoassay in 59% and using complement fixation serology in 76% of parainfluenza infections. Direct antigen detection was especially useful in infants. We suggest that direct antigen detection should be used as a primary virological diagnostic method in small children with middle and lower respiratory tract infections.

Age Factors↗

Time-resolved fluoroimmunoassay compared with virus isolation for rapid detection of respiratory syncytial virus in nasopharyngeal aspirates.

Two monoclonal antibodies against two distinct conserved epitopes of the respiratory syncytial virus (RSV) nucleocapsid protein were used in a direct time-resolved fluoroimmunoassay (TR-FIA) for the detection of RSV antigens in nasopharyngeal aspirates. The capture antibody was adsorbed to the solid phase of microdilution strip wells, and the indicator antibody was labeled with a europium chelate. Specimens and label were incubated simultaneously for 1 h at 37 degrees C in the coated wells. After the test samples were washed, fluorescence enhancement solution was added, strips were shaken, and the time-resolved fluorescence was measured. The test procedure took only 75 min, and the total time for 20 specimens, with pretreatment by sonication, was 2 to 3 h. We prospectively evaluated the detection of RSV in nasopharyngeal aspirates of pediatric patients by TR-FIA and by virus isolation in human diploid fibroblasts. TR-FIA detected 40 of 42 isolation-positive specimens. Nine additional isolation-negative specimens were positive by TR-FIA; all proved to be true positives by a blocking-type confirmatory assay. The sensitivity, specificity, positive predictive value, and negative predictive value for TR-FIA were 95, 96, 82, and 99%, respectively, of the values obtained by virus isolation and 96, 100, 100, and 99%, respectively, of the values obtained by virus isolation and the confirmatory assay.

Adolescent↗