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Biomedical subjects

P E Halonen

Publications and source records attributed to P E Halonen.

At least 37 records · Page 2Linked to original sources
PubMed1980

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.

Adenoviruses, Human↗
PubMed1979

Solid-phase radioimmunoassay of IgA, IgG, and IgM antibodies to human rotavirus.

A solid-phase radioimmunoassay (RIA) has been developed for the detection of human rotavirus-specific IgA, IgG, and IgM antibodies. Nebraska calf diarrhea virus grown in LLC-MK2 cell cultures in the presence of trypsin was directly adsorbed onto polystyrene balls, and antibodies that attached to the virus-coated balls were detected by subsequent binding of 125I-labeled antibodies specific to human alpha, gamma or mu chains of human Iga, IgG, or IgM immunoglobulins. A total of 116 serum specimens from 58 adult patients were tested. Binding ratios between the positive and the negative serum varied between 5 and 15, occasionally being 20 or more in the IgA and IgG assays, but rarely exceeding 3 in the IgM assay. The RIA was found to be more sensitive in detecting antibodies to rotavirus than the complement fixation (CF) test, the RIA titers obtained being 50--100 times as high as the CF titers. The method described offers a possibility of evaluating the immune response to human rotavirus and of detecting recent infection.

Adult↗
PubMed1979

Comparison of four-layer radioimmunoassay and electron microscopy for detection of human rotavirus.

A four-layer radioimmunoassay (RIA) using polystyrene beads as the solid phase, anti-rota guinea pig IgG as primary antibody, anti-rota rabbit IgG as secondary antibody, and 125I-labelled sheep anti-rabbit immunoglobulin as indicator antibody has been developed for the detection of human rotavirus in stool specimens. A comparison was made of the developed RIA, routine electron microscopy, and research electron microscopy of 147 unconcentrated stool specimens from patients with infantile gastroenteritis. In routine electron microscopy 17 (11.6%) false-positive or false-negative results were obtained when compared with research electron microscopy. Each specimen positive in research electron microscopy was positive in RIA, and six additional RIA positives were found from 58 electron microscopy negative specimens. A confirmatory test was necessary to find out marginally positive but nonspecific reactions in RIA. The developed radioimmunoassay is slightly more sensitive than research electron microscopy of unconcentrated stool specimens and considerably more sensitive and more specific than routine electron microscopy.

Child↗
PubMed1978

Herpes simplex virus subunit antibodies in patients with Parkinson's disease.

Serum IgG antibodies against herpes simplex virus (HSV) type 1 capsid, envelope, and excreted antigens in 52 patients with idiopathic Parkinson's disease, and in their age- and sex-matched controls, were assayed with a solid-phase radioimmunoassay. When compared with the controls, patients with Parkinson's disease were found to have a substantially increased antibody response against each of the HSV subunit antigens tested. The increased antibody response in patients with Parkinson's disease was not associated with the occurrence of recurrent HSV infections, since the difference in antibody levels was most evident when comparing patients without recurrent HSV infections with their respective control group. Consequently, the increased HSV antibody response in patient with Parkinson's disease might depend on some antigenic stimulation other than ordinary recurrent HSV infections, or alternatively, on the generally enhanced immunological reaction of the patients against HSV.

Aged↗
PubMed1978

Solid-phase radioimmunoassay determination of virus-specific IgM antibody levels in a follow-up patients with naturally acquired measles infections.

The question of the exact disappearance time or possible persistence of measles-specific IgM antibodies after naturally acquired measles virus infections was studied with a sensitive solid-phase radioimmunoassay (RIA) method. A total of 30 patients were analyzed with follow-up times varying from 4.5 to 8 months; all were measles IgM positive in the first serum specimen obtained after the onset of rash. In 29 of 30 patients, the measles IgM declined to undetectable levels by approximately 90 days. The remaining patient developed postmeasles encephalitis, however, and was found to have a prolonged measles IgM antibody response. For comparison, the measles-specific IgG response was also studied and was found to develop only slightly later than the IgM response, with levels then remaining high and stable up to 8 months later. Although apparent measles IgM antibodies were found in 1 of 64 nonmatched adult controls, they were due to the presence of high levels of IgM-class rheumatoid factor. The data presented indicate that measles IgM antibodies begin to decline soon after the onset of rash and reach negative levels 1 to 3 months later; in complicated infections, however, measles IgM antibody synthesis may not terminate normally.

Adolescent↗
PubMed1977

Solid-phase radioimmunoassay detection of rubella virus IgG antibody in serum and CSF of patients with multiple sclerosis.

Low levels of rubella virus IgG antibody have been detected in cerebrospinal fluid (CSF) specimens of multiple sclerosis (MS) patients by a solid-phase radioimmunoassay (RIA) previously developed for testing of clinical serum samples. Paired serum and CSF specimens of 36 MS patients and 12 control patients were analyzed. Of those MS patients which had negative CSF titers in the rubella hemagglutination inhibition (HAI) test, 90% (11/12) were found to have rubella IgG antibody by the RIA method. In specimens found to contain rubella IgG antibodies by both methods, the RIA test was approximately 15 times more sensitive than the rubella HAI test. The results presented suggest that a considerable portion of MS patients have significantly reduced serum/CSF rubella IgG antibody ratios, indicating that there is a local production of rubella antibodies in the central nervous system of these patients.

Adult↗
PubMed1977

Viral antibodies in the sera from patients with Parkinson disease.

An assay of antibodies to 15 various viruses and mycoplasma pneumoniae was performed on the serum specimens from 441 patients with Parkinson disease and from 443 healthy controls matched by sex, age, and place of residence, or from a representative group of these matched pairs. The main finding was a higher herpes simplex complement-fixing antibody level in patients with Parkinson disease than in controls. Patients with Parkinson disease had higher herpes simplex antibody titers more often than did their matched controls, and the matched controls, respectively, had low titers more often than the patients. The mean herpes simplex antibody titer (log2) of the patients (4.9) was significantly higher than that of controls (4.6) (p less than 0.01). This difference was also demonstrable when matched pairs were analysed for paired differences of herpes simplex antibody titers. For other viral CF and HI antibodies studied and for mycoplasma pneumoniae CF antibody, there were no significant differences either in the mean titers or in the distribution of individual titer values between the patients with Parkinson disease and the matched controls.

Aged↗
PubMed1976

Solid-phase radioimmunoassay of rubella virus immunoglobulin G and immunoglobulin M antibodies.

A solid-phase radioimmunoassay method has been developed for the detection of rubella virus-specific immunoglobulin G (IgG) and IgM antibodies in human serum specimens. Purified rubella virus was adsorbed onto polystyrene balls, and antibodies that attached to the virus-treated balls were detected by subsequent binding of 125I-labeled anti-human gamma or anti-human mu immunoglobulins. A total of 77 serum specimens were tested. Binding ratios between positive and negative sera were as high as 22 in the IgG assay but rarely exceeded 3 in the IgM assay. The sensitivity of the IgG assay was found to be 16 to 256 times higher than that of the rubella virus hemagglutination inhibition test. The IgG radioimmunoassay can be readily adopted for routine diagnostic use. The IgM radioimmunoassay, however, due to its lower sensitivity, must be modified before being routinely applied.

Antibodies, Viral↗
PubMed1975

Virus antibody levels in serum specimens from patients with optic neuritis and from matched controls;.

Virus antibody levels in serum specimens taken in acute and convalescent phases from 77 patients with optic neuritits were tested by measles hamagglutination inhibition (HI), measles hemolysis inhibition (HLI), rubella HI, parainfluenza-1 HI, Epstein-Barr immunofluorescence (IF), and against 11 other viruses and mycoplasma pneumoniae with the complement fixation (CF) technique. The virus antibody levels were indicated to be usually very stable, and a fourfold change in virus antibody levels was demonstrated in only eight patients. The virus antibody levels were compared with specimens from two carefully selected control groups. The first control group consisted of 71 healthy persons matched in age, sex and place of residence with the patients with optic neuritis. The other control group consisted of 58 patients with various neurological diseases other than multiple sclerosis (MS) or infectious diseases of the central nervous system. The patients with optic neuritis had significantly higher measles antibody titres than the two control groups in both measles HI and measles HLI tests. Also in 33 patients with optic neuritis of unknown cause, the measles antibody levels were higher than in the control groups. On the other hand, various other antibody tests showed no statistically significant differences between patients with optic neuritis and the control group.

Acute Disease↗
PubMed1975

Virus antibody levels in the cerebrospinal fluid from patients with optic neuritis.

Virus antibody levels were studied in the cerebrospinal fluid (CSF) of 58 patients with optic neuritis and 58 control patients with no indication of multiple sclerosis (MS) or infectious disorders of the central nervous system (CNS). The specimens were tested against three different structural components of measles virus with measles hemagglutination inhibition (HI), measles hemolysis inhibition (HLI) and gel precipitation (GP) tests. Measles antibodies occurred in 62 per cent of CSF specimens from patients with optic neuritis, and 21 per cent of the controls. In the specimens from patients with optic neuritis, the positive rate figures were: for rubella HI test 35, parainfluenza-1 HI 16, and Epstein-Barr virus immunofuorescence (IF) 53 per cent. The frequencies in the control group were 10, 10 and 26 per cent, respectively. Serum/CSF antibody ratios below 80 occurred in measles tests in 45 per cent of patients with optic neuritis and 16 per cent of the control group. Some patients with optic neuritis (but none from the control group) had a reduced serum/CSF antibody ratio in more than one measles antibody test, The patients with optic neuritis had a higher frequency of low serum/CSF albumin ratios indicating blood brain barrier damage, There were, however, several patients with a normal serum/CSF albumin ratio but low serum/CSF immunoglobulin G and measles antibody ratios. This supports the hypothesis that local production of measles antibodies takes place in CNS in some patients with optic neuritis as well as in MS patients. The CSF specimens were further tested against 12 other viruses and mycoplasma pneumoniae complement fixation, but there were no positive specimens. New CSF specimens were taken from five patients during optic neuritis, and from seven patients later on during the follow-up because of the appearance of new neurological symptoms. There were no changes in virus antibody levels, except for two patients with an increase of measles virus antibody titres.

Adolescent↗
PubMed1969

Preparation of La Crosse virus hemagglutinating antigen in BHK-21 suspension cell cultures.

Hemagglutinating and complement-fixing antigens of La Crosse virus (California arbovirus group) were produced in serum-free suspension cultures of BHK-21/13S cells. The appearance and production of these antigens were correlated with the titer of infectious virus. No significant differences in antigen titers were produced by varying virus dose 10-fold. Hemagglutinin appeared 6 to 8 hr after inoculation and reached peak titer in 14 to 22 hr. Both beta-propiolactone and Tween 80-ether treatment inactivated infectious virus in the antigens. Unlyophilized antigen was stable at -60, 5 and 24 C for at least 117 days but not for 1 year. Lyophilized antigen was stable for at least a year, however, at -20 and 5 C. Cell culture-produced antigen was more sensitive than brain-produced antigen in detecting hemagglutination inhibition antibody in human sera.

Animals↗