Comparison of nucleic acid hybridization with enzyme immunoassay and isolation for detection of Chlamydia trachomatis.
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Biomedical subjects
Publications and source records attributed to H Tuokko.
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In February-March 1985 an oral poliovirus vaccine campaign was launched in Finland in a population vaccinated earlier with inactivated poliovaccine. During this campaign a strain of poliovirus was isolated from the cerebrospinal fluid (CSF) of a 7-year-old girl 34 days after she had received oral poliovirus vaccine. She had long-lasting headache, vomiting and fever but no paralysis. This case demonstrates that poliovaccine virus can invade the central nervous system even after a complete course of inactivated poliovirus vaccine if the inactivated vaccine has been poorly antigenic against one of the three types of virus.
Memory functioning of normal elderly subjects and patients with suspected malignant memory disorders were examined using a cued recall memory assessment procedure. Levels of psychosocial functioning were rated by a multidisciplinary team. Ability to engage in free and cued recall was studied to determine the relationship between problems of acquisition and retrieval. Normal and impaired elderly showed strong differences on free recall and total recall resulting in 90.58% and 79.06% rates of accuracy of prediction of group membership. There were significant multivariate and univariate differences among the memory-impaired groups defined in terms of their psychosocial functioning. These findings indicate that differences in acquisition and retrieval are associated with increasing impairment of psychosocial functioning. Patients whose psychosocial functioning was rated as falling within the questionable range exhibited only deficits in retrieval. Patients whose psychosocial functioning was rated as more severely impaired, exhibited problems of retrieval and acquisition.
Acute phase and convalescent sera from 51 pediatric patients who had a documented viral infection and no obvious culture-confirmed bacterial infection such as meningitis, otitis media or urinary tract infection were tested by enzyme immunoassay for antibodies to Haemophilus influenzae and Branhamella catarrhalis and by the latex agglutination test for pneumococcal antigens to evaluate the frequency of mixed bacterial and viral infections. A mixed bacterial and viral infection was documented in 19 patients (37%). Seven patients (14%) showed a diagnostic rise in antibodies to H. influenzae and 8 patients (16%) showed an antibody elevation to B. catarrhalis in their paired sera; pneumococcal antigen was detected in acute phase serum from 4 patients (8%). The rate of mixed infections in patients having respiratory symptoms was 52%. High serum C-reactive protein values and white blood cell counts were found significantly more often in those with mixed infections than in those who had viral infections. The results indicate that mixed bacterial and viral infections occur more frequently in children than one could anticipate on the basis of the earlier reports. Mixed bacterial and viral etiology is highly probable in a child who has a defined viral infection with high C-reactive protein and white blood cell count values, especially in the presence of respiratory symptoms.
Head trauma has been found with greater frequency in the histories of Alzheimer patients than age-matched controls in some studies, but not in others. We hypothesized that events that accelerate neuron loss, such as significant head trauma, hasten the onset of symptoms of Alzheimer's disease in persons vulnerable to the disorder. Retrospective data on 148 probable Alzheimer patients and 33 demented controls were examined. Alzheimer patients with severe head injury before the age of 65 showed onset of symptoms at an earlier age than Alzheimer patients without head trauma.
Positron emission tomography (PET) has dramatically improved our ability to examine the functioning of the living brain. PET studies of neural pathways of the major sensory modalities--auditory, visual, somatosensory--have confirmed many traditional neuropsychological concepts, such as cross-lateral representation and regional functioning to particular primary sensory cortical areas. Other PET studies have used radioisotopes to examine relationships between radiopharmaceutical agents and neurobehavioral functioning in both normal and neuropathological states. In some areas, PET methodology requires further refinement. For example, effort should be made to develop the technology to do multiple scans within a short time frame; statistical procedures to examine relationships between neuropsychological tasks and the activity or presence of radiopharmaceutical agents in multiple sites; adequate controls for experimental error; and activation paradigms controlling the nonspecific effects of simple arousal. PET activation models of cognition suggest that a "systems efficiency" approach to assessing neuropsychological test performance involving both serial and parallel processing would be useful. These developments will improve empirical methodology and our understanding of brain-behavior relationships.
A family with familial Alzheimer's disease (FAD) inherited as an apparent autosomal dominant trait is presented. Twelve individuals (6 females; 6 males) in 4 generations were affected. The disease had its onset in the late 30's, early 40's with death by age 50. Although FAD which appears to be transmitted as an autosomal dominant trait is relatively rare, such families must be identified and carefully counselled with respect to recurrence risks for subsequent generations. In this family, there are currently 20 members of Generation IV, aged 15-37, and 9 members of Generation V, aged 1-11. The majority of these individuals appear to have a 50% risk for developing this disease.
The methods of reverse type enzymeimmunoassay (EIAs) with biotinylated antigens were used to determine IgM antibodies to measles virus in human sera. These antigens, either purified measles virus antigen or lysate type measles-vero antigen with lysate vero control antigen, were used in the two separate IgM-tests. Paired sera from 15 measles patients as well as 456 sera from patients with viral infections other than measles, with mycoplasma pneumoniae infections, from rheumatoid arthritis patients and blood donors, were assayed in a dilution of 1:200. Both the test systems detected all the 30 serum specimens from the measles patients as measles IgM positive, but the sera of all the other groups proved to be measles IgM negative. These tests developed for measles specific IgM antibodies, avoiding the interference of IgM-class rheumatoid factor, offer valuable tools for routine virus serology.
The value of viral antigen detection from nasopharyngeal secretion (NPS) by enzyme immunoassay (EIA) in everyday clinical practice was evaluated in 570 children hospitalized because of infections. NPS-EIA gave a positive result in 32% of all cases. Virus isolation was positive in the NPS in 25%, virus isolation in stool samples in 14%, and virus serology in 28% of the cases. NPS-EIA was superior for detecting adenovirus, respiratory syncytial (RS) and parainfluenza viruses. In a series of 124 patients in whom 3 methods were compared, NPS-EIA was the only positive method in 48% of all findings positive for adenoviruses, in 73% for RSV, and in 58% for parainfluenza viruses. Antigen detection by NPS-EIA markedly increased the diagnostic potential in everyday clinical practice, especially for viral respiratory diseases.
Fuld (1984) described a WAIS profile associated with drug-induced cholinergic deficiency in young adults and dementia of the Alzheimer's type. The frequency of occurrence of this profile was examined in a group of healthy elderly persons who were administered the WAIS. The results of this study suggest that the profile occurs rarely in independently functioning elderly persons, thus lending support to Fuld's findings that the profile may be relatively specific to dementia of the Alzheimer's type. Hypotheses as to the significance of this index of pathology are discussed.
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Fourteen patients who had clinically diagnosed Alzheimer's disease with mild to severe dementia (mean age 69.1 years) were evaluated by calculation of local cerebral metabolic rate for glucose (LCMR-gl) based on uptake of 18F-2-fluoro-2-deoxyglucose (FDG) detected with positron emission tomography (PET). PET scanning showed that the patients had significantly lower LCMR-gl values than 11 age-matched neurologically normal volunteers (mean age 66.3 years). The differences were most marked in the temporal cortex, followed by the frontal, parietal and occipital cortex. In each case the LCMR-gl value was below the lowest control value in at least one cortical area and usually in several; the reduction in LCMR-gl and the number of regions involved in the patients increased with the severity of the dementia. Deficits noted in neuropsychologic testing generally correlated with those predicted from loss of regional cortical metabolism. The patients with Alzheimer's disease were also examined with magnetic resonance imaging, computed tomography or both; the degree of atrophy found showed only a poor correlation with the neuropsychologic deficit. Significant atrophy was also noted in some of the controls. A detailed analysis of LCMR-gl values in selected cerebral regions of various sizes refuted the hypothesis that the reduction in cortical glucose metabolism in Alzheimer's disease is due to the filling by metabolically inert cerebrospinal fluid of space created by tissue atrophy.
Live attenuated mumps virus vaccine and Formalin-inactivated mumps vaccine were compared for their ability to induce antibody responses and cell-mediated immune responses as measured by a lymphocyte blast transformation test (LBT). The subjects studied were conscripts of the Finnish Defense Forces. In seronegative subjects antibody levels induced by attenuated virus were more variable than those induced by inactivated virus, including one failure with the live vaccine out of a total of nine subjects. IgM antibody class response was seen only in four of nine subjects vaccinated with live virus--in those subjects with the highest post-vaccination antibody levels and strongest LBT responses. Increases of antibody levels in originally seropositive subjects were higher in subjects vaccinated with inactivated virus. Cell-mediated immunity induced by both vaccines was relatively poor when measured by the LBT test. At a time of 6-8 months after vaccination, LBT responses in originally seronegative subjects were not observed.
Rubella virus-infected cells were fractionated by differential and sucrose gradient centrifugations. Rubella virus antigens distributed into all fractions but particulate material in the 100,000 x g pellet was shown to be enriched about two-fold for rubella virus antigen. Similarly, sucrose gradient fractions for rough endoplasmic reticulum and smooth cellular membranes were enriched for rubella virus antigens. The 100,000 x g pellet and the isolated cellular membranes proved to be useful when different fractions were used in solid-phase immunoassays for rubella virus-specific IgG or IgM. These fractions were equal in quality of the semipurified rubella virus preparations in the IgG assays but inferior to those in the IgM assays. However, simultaneous use of 35/25% sucrose fractions from infected and non-infected cells reveals non-specific binding of IgM to the antigens and renders the IgM tests more specific for rubella virus.
Serum specimens collected from patients convalescing from acute measles or mumps infections, other viral infections, or rheumatoid arthritis and from blood donors were tested in indirect and reverse assays for measles and mumps immunoglobulin M (IgM) antibodies. All the samples from patients convalescing from acute mumps and measles infections gave positive IgM results in both tests. However, 6% of sera from patients recovering from other viral infections, 68.4% of sera from patients with rheumatoid arthritis, and 5.6% of sera from normal blood donors gave false-positive results by the indirect measles IgM enzyme immunoassay (EIA). By the indirect mumps IgM EIA, 9% of sera from other viral infections, 70.1% of sera from patients with rheumatoid arthritis, and 5.6% of sera from normal blood donors gave false-positive reactions. The reverse test system for measles IgM gave false-positive results in 1.5% of sera from the group with other viral infections, and the reverse mumps EIA gave false-positive results in 0.9% of the patients. Other sera groups did not react in either measles or mumps reverse IgM assays. The results indicated that although nonspecific reactions are frequent in indirect IgM tests for viral antibodies, such reactions are rarely encountered when reverse IgM EIA tests are employed.
A method of solid-phase enzyme-immunoassay (EIA) with horseradish-peroxidase-conjugated anti-mu-globulin was used to determine IgM antibodies to measles virus in human sera. Antigens prepared from measles-infected and noninfected Vero cells passively adsorbed to polystyrene cuvettes were both important for the tests, because sera from many patients convalescing from viral infections and sera from rheumatoid arthritis patients were able to bind to control antigen. Sera from measles patients, patients with other viral infections, rheumatoid arthritis (RA) patients, and from blood donors were tested in a dilution of 1:200. Almost all of the acute-phase measles sera (37/38) were positive. The first measles-IgM-negative specimen was found 9 weeks after the onset of rash. Seven percent (15/213) of patients with other viral infections gave positive results in these IgM tests. False-positive reactions were also found in 33 of 51 (65%) sera from RA patients. This nonspecific binding could be abolished by absorptions with latex-IgG particles. This treatment did not have any effect on specific IgM. The IgM-EIA test developed for measles virus antibodies, which requires only a single serum specimen, appears to be a useful diagnostic method for routine virus laboratories.
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.
Three solid-phase forms of human IgG were compared for their ability to function as the binding target in an enzyme immunoassay for IgM-class rheumatoid factor (RF). IgG was either directly adsorbed to polystyrene beads (method A), or immunologically (method B) or covalently (method C) bound to protein adsorbed to beads. The data presented indicate that C is the method of choice for the preparation of the RF assay solid-phase IgG.