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Biomedical subjects

P Halonen

Publications and source records attributed to P Halonen.

At least 127 records · Page 7Linked to original sources
PubMed1985

Direct enzyme immunoassay for detection of specific IgG antibody to rubella virus by use of labelled antigen.

A new solid phase enzyme immunoassay (EIA) for detection of rubella-specific immunoglobulin G (IgG) antibody was developed. The test uses polystyrene microtiter strips coated with rabbit anti-human IgG immunoglobulins as the solid phase and an enzyme-labelled semipurified rubella antigen as indicator. The direct EIA was compared with hemagglutination inhibition (HI), single radial hemolysis (SRH), radioimmunoassay (RIA) and time-resolved fluoroimmunoassay (TR-FIA) using 52 serum specimens from patients with remote rubella infection. The overall agreement of direct EIA with HI was 96.1%, with SRH and RIA 98.1% and with TR-FIA 100%. The linear regression coefficient varied from 0.77 to 0.91, the best being obtained with direct EIA and SRH. The direct EIA was also suitable for diagnosis of acute infections, as a significant increase in antibody levels was detected in all paired specimens tested from patients with acute rubella infection. The sensitivity and were comparable to those of the assays employed. An advantage of the present assay is that the same method and same labelled antigen can be used to test for different classes of antibody using simply a solid phase with capture antibodies of different chain specificity.

Adult↗
PubMed1985

Quantitative vibration perception thresholds in patients under prolonged antiepileptic treatment.

Quantitative vibration perception threshold (VPT) measurements were performed on 134 healthy subjects and 147 epileptics undergoing prolonged (more than one year) antiepileptic treatment, 28 patients received diphenylhydantoin, 71 carbamazepine and 11 some other drug. 37 subjects received a combination of drugs, which included diphenylhydantoin and/or carbamazepine. VPT was measured quantitatively at the dorsum of the right foot with a device vibrating at 100 Hz. The mean of the four successive threshold values was calculated. VPTs of the epileptic groups treated with diphenylhydantoin, carbamazepine or combined medication were all significantly (P less than 0.001) higher than those of the control group. The group receiving other medication showed no difference in this respect. The percentage of patients with abnormal thresholds was about the same (10-16) in the epileptic groups. An exception was the group taking other medication, in which no abnormal VPTs were found. It is suggested that such quantitative measurement may be a useful screening method for detecting dysfunction in the peripheral nervous system due to prolonged antiepileptic treatment. It will, however, be necessary to test the clinical validity of the method for diagnosing manifest or subclinical polyneuropathies.

Adolescent↗
PubMed1985

Detection of specific immunoglobulin M antibody to rubella virus by use of an enzyme-labeled antigen.

A direct antibody capture enzyme immunoassay (EIA) for the detection of rubella-specific immunoglobulin M (IgM) antibody was developed. Polystyrene microtiter strips coated with rabbit anti-human IgM were used as solid phase, and a semipurified rubella antigen labeled with horseradish peroxidase was used as indicator. By testing a panel of 238 serum specimens (not including sera from newborns with congenital rubella), the direct EIA was compared with the indirect EIA used routinely in our diagnostic unit and with a commercial IgM capture EIA (RubEnz M II) that employs a horseradish peroxidase-labeled anti-rubella monoclonal antibody as indicator. Overall agreement of direct EIA with indirect EIA and RubEnz M II was 95%, whereas agreement between direct and indirect EIA was 96.2%, and agreement between direct EIA and RubEnz M II was 97.8%. Sensitivity of the direct assay was higher than that of the indirect EIA and similar to that of the RubEnz M II assay. Specific IgM antibody could always be detected in serum specimens taken from patients with primary acute rubella infection between days 4 and 56 after the onset of rash. The assay was highly specific, and it was not affected either by rheumatoid factor or by high levels of specific IgG in sera. Another important advantage that the direct EIA has over the indirect EIA is that it requires 10 to 20 times less antigen per serum specimen tested.

Antibodies, Viral↗
PubMed1984

Diagnosis of respiratory syncytial virus infection in children: comparison of viral antigen detection and serology.

Direct detection of viral antigen in nasopharyngeal secretion by radioimmunoassay was compared with serology by IgG antibody enzyme immunoassay for diagnostic efficacy in 77 children with clinically suspected respiratory syncytial virus (RSV) infections. Antigen detection gave a positive diagnosis in 26 of 33 (79%) children in whom RSV infection was diagnosed by any of the two methods. The diagnostic efficacy of antigen detection was dependent upon the interval after onset at which specimens were collected; 88% of specimens taken during the first 5 days and 50% of specimens taken 6-10 days after onset of illness were positive. It was also dependent on the age of the patients, the diagnostic efficacy being 88 and 76% in children under and over 6 months of age, respectively.

Antigens, Viral↗
PubMed1984

Immunoglobulin class-specific antibody response in respiratory syncytial virus infection measured by enzyme immunoassay.

Immunoglobulin class-specific enzyme immunoassay (EIA) was used for determination of antibody responses in sera collected from 26 children with acute primary respiratory syncytial virus (RSV) infections. All 26 patients had IgG antibody responses with a significant titer increase in 24 (92%); an IgM antibody response was detected in 19 of the 26 (73%). From patients aged 6 months or less only 5 of 8 produced detectable IgM antibodies, whereas all patients aged 1-2 years did so. IgM antibodies appeared within 1 week after onset of illness and persisted from 20 days to 2-3 months. An IgA antibody response was observed in 20 of 26 (77%) patients with a significant titer increase detected in 17 of 26 (65%) patients. In some patients the persistence of IgA antibodies followed that of the IgM antibodies, but in others the IgA antibody titers remained stable up to the end of the follow-up. The most sensitive assay system for serological diagnosis of acute RSV infection in children was the determination of titer increases by IgG antibody.

Adult↗
PubMed1984

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.

Adenoviridae Infections↗
PubMed1984

Viral diagnoses using the rapid immunofluorescence technique and epidemiological implications of acute respiratory infections among children in different European countries.

From November 1978 to October 1981, a total of 7716 specimens of nasopharyngeal secretions were examined by the rapid immunofluorescence technique to determine the frequency of infections caused by the respiratory syncytial virus (RSV), influenza virus A, and parainfluenza viruses 1 and 3. The tests were carried out in six different virus laboratories located in Newcastle upon Tyne (England), Copenhagen, Oslo, Stockholm, Turku (Finland), and Vienna; laboratories in Lisbon and Paris participated in the study for shorter periods. The specimens were collected from infants and children less than 6 years of age who had been admitted to hospital with an acute respiratory infection. Standardized techniques and quality controlled reagents were used. At least one of the above viruses was detected in 1927 (25%) of the specimens: RSV in 1475, influenza virus A in 123, parainfluenza virus 1 in 110, and parainfluenza virus 3 in 237 specimens. Respiratory syncytial virus dominated in all centres, but in some Scandinavian centres distinct outbreaks due to this virus occurred only once or twice during the 3 years' study period. Three outbreaks of RSV were observed in Newcastle, but here an unprecedented delay of the first winter's epidemic occurred. The delay was associated with prolonged school closures in the area, and with a very early outbreak of influenza. Parainfluenza virus 3, which was predominantly a summer virus in Newcastle, was most frequently encountered during the colder months of the year in the other centres.

Acute Disease↗
PubMed1983

Novel test for rapid viral diagnosis: detection of adenovirus in nasopharyngeal mucus aspirates by means of nucleic-acid sandwich hybridisation.

Nucleic-acid sandwich hybridisation detected adenovirus in nasopharyngeal aspirates from children with acute respiratory infections within 20 h. The differentiation between subgroups of adenovirus (B and C) and the lack of false positives indicated the specificity of the method. The reference test was detection of an adenovirus protein (hexon) by means of radioimmunoassay. In nucleic-acid sandwich hybridisation the sample DNA mediates the binding of a labelled "probe" DNA fragment to a second DNA fragment bound on filter. The sample DNA itself is not fixed to a solid support, and the only pretreatment required is boiling in a detergent solution. The results indicate that the sandwich hybridisation is specific, quantitative, easy to do, and only marginally affected by the crude nature of the sample. It may therefore be a valuable addition to the range of rapid methods in microbial diagnosis.

Acute Disease↗
PubMed1983

Antibodies to measles virus in ankylosing spondylitis.

IgG antibodies to measles virus were measured by a solid-phase radio-immunoassay in serum specimens from 31 patients with confirmed ankylosing spondylitis (AS), from 8 patients with symptoms and signs resembling AS and from 39 patients hospitalized for various non-rheumatological disorders. The patients with AS and without iritis/uveitis had a 4-fold increased amount of measles antibodies in their serum specimens compared with the control patients (p less than 0.01). The AS patients with iritis and the patients with symptoms and signs resembling AS were, in this respect, similar to the control patients.

Adult↗
PubMed1981

Herpesviruses and parkinsonism. Herpes simplex virus types 1 and 2, and cytomegalovirus antibodies in serum and CSF.

Antibodies against herpes simplex virus (HSV) types 1 and 2 and cytomegalovirus (CMV) were assayed with a microindirect hemagglutination (IHA) test in the serum of 67 pairs of patients with Parkinson's disease and controls. Cerebrospinal fluid from 30 pairs was assayed. All patient and control serum was tested with a radioimmunoassay (RIA) for antibodies against HSV type 1 subunit antigens. Serum IHA antibody level against HSV type 1 was increased in patients with Parkinson's disease and RIA antibody levels against the same viral antigen were significantly higher in the patients than controls. Herpes simplex virus type 2 and CMV serum antibodies were equal in the patient and control groups. Most of the CSF samples tested negatively for IHA; small and comparable numbers of the patients and controls had low antibody levels against HSV and CMV antigens.

Antibodies, Viral↗
PubMed1981

Solid-phase radioimmunoassay of serum IgG, IgM, and IgA antibodies to cytomegalovirus.

A radioimmunoassay (RIA) using polystyrene beads as the solid phase for cytomegalovirus (CMV) antigen and iodinated immunosorbent purified anti-human IgG, IgM, and IgA as indicator antibodies was developed for the detection of immunoglobulin class-specific antibodies to CMV. An antigen prepared from extracellular virus was essential for reliable results, and a preparation ultracentrifuged and sonicated twice was better than a crude antigen. The optimal antigen gave low cpm values with a negative reference serum, resulting in cpm ratios of 10 or higher between early convalescent phase serum and negative reference serum. Of six patients with an increase in CMV CF titres, all six had an increase in RIA IgG titres, four had an increase in IgA titres, and all had IgM antibodies. The IgG titres were high, up to 1/64,000. In a group of 17 infants negative in CMV CF test, 14 had CMV IgG antibodies in RIA test, indicating mainly low levels of maternal antibodies. In six of seven patients with CMV isolations from urine specimens, an increase in IgG or IgA titres or the presence of IgM antibodies was found, and only one of these patients had an increase in CMV CF titre. The specificity of the developed CMV RIA test was further demonstrated by detecting no significant increase in RIA titres in serum specimens of patients with primary herpes simplex infection, chickenpox, herpes zoster, or infectious mononucleosis.

Antibodies, Viral↗
PubMed1981

Chlamydia trachomatis and herpes simplex virus IgA antibodies in cervical secretions of patients with cervical atypia.

The association of Chlamydia trachomatis (CT) and herpes simplex virus (HSV) with malignant or premalignant changes in the cervix uteri was studied by determining immunoglobulin A (IgA) antibodies in the cervical secretions of 28 women with inflammatory, 28 with dysplastic, 7 with malignant changes of the uterine cervix, and 26 healthy controls. In cervical secretions IgA antibodies to CT were found in 24 of 35 (69%) patients with malignant or premalignant changes, in 11 of 28 (39%) with cervicitis and in 3 of 26 (12%) controls. IgA antibodies to HSV were found in 10 of 35 (28%) patients with malignant atypic or dysplasia but in none of the women with cervicitis or the controls. The highest frequency of antibodies was found in the patients with cervical carcinoma. Serum IgA antibodies to CT and HSV were found equally on the patients and the controls. Our results suggest that in patients with cervical atypic, local IgA CT antibody production occurs. Whether this association is aetiological or coincidental can not be concluded from this study.

Adult↗