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Biomedical subjects

K Penttinen

Publications and source records attributed to K Penttinen.

At least 55 records · Page 3Linked to original sources
PubMed1978

Use of ELISA for measuring immunoconglutinins.

An enzyme-linked immunosorbent assay (ELISA) for detection of immunoconglutinins (IKs) has been developed. IKs are allowed to bind to solid-phase C3 and are then assayed using alkaline phosphatase coupled to anti-IgG or anti-IgM. IK activity was detected in some patients' sera up to 50,000-fold dilution. Significant correlation (r = 0.65) was obtained between the levels of IgM-IKs measured by ELISA and by conventional hemagglutination assay, IgG-IKs and hemagglutination titers did not correlate (r = -0.15).

Alkaline Phosphatase↗
PubMed1978

Differences in antibodies to the surface components of mumps virus after immunization with formalin-inactivated and live vaccines.

Military recruits with or without antibodies to mumps virus were immunized with live or formalin-inactivated mumps virus vaccines. Antibodies to the two major surface components of the virus, the hemagglutinin and the hemolysin, were identified separately. Immunization with the live vaccine did not change the humoral immunity in individuals with detectable antibodies. In seronegative recruits immunization with the live vaccine induced an antibody response against both the hemagglutinin and the hemolysin corresponding to the quality of the immune response after natural infection. In contrast, the formalin-inactivated vaccine only induced an antibody response against the hemagglutinin. This effect was found after immunization of both seronegative and seropositive individuals. The latter displayed a selective boosting of titers of hemagglutination-inhibiting antibody. These findings may have relevance for the interpretation of the short-lived immunity after the use of formalin-inactivated mumps vaccine without repeated boosting.

Antibodies, Viral↗
PubMed1977

Association of serum lipids and obesity with cardiovascular mortality.

Serum lipid concentrations, relative body weight, and smoking habits were assessed in a cohort of 1648 middle-aged Finnish men who were subsequently followed for seven years. Multivariate analysis showed that serum triglyceride and cholesterol concentrations and smoking were all independently associated with cardiovascular mortality. High serum triglyceride concentrations increased the risk of cardiovascular death only when they exceeded 1.7 mmol/l (150 mg/100 ml), but this occurred at all cholesterol and relative body weight levels. Obesity influenced death rates only in men with raised serum lipid levels, while smoking was associated with increased mortality when any combination of the other factors was present. Men who had raised triglyceride concentrations combined with smoking or obesity had the highest risk of cardiovascular death.

Cardiovascular Diseases↗
PubMed1977

Enzyme-immunoassay in the detection of hepatitis B surface antigen.

A new enzyme-immunoassay (EIA, Hepanostika Microelisa System) for the detection of hepatitis B surface antigen was evaluated against other methods, namely complement fixation, Hepanosticon, AusRIA II and Finnish Red Cross Radioimmunoassay (FRC-RIA). EIA detected the greatest number of positive samples in a serum panel consisting of 142 sera from clinical hepatitis patients. FRC-RIA was the most sensitive method for subtype ad, while EIA detected the ay specimen at the highest dilution. None of the test systems gave the 'optimal' result in the screening test, and it is proposed that a separate procedure for each antigen subtype should be carried out to detect the greatest number of positive samples.

Complement Fixation Tests↗
PubMed1977

The effect of HLA antibodies on platelet aggregation.

Twelve different HLA antisera, detecting antigens of both A and B series and the superspecificities w4 and w6, were tested for platelet-aggregating activity in 75 antiserum-platelet combinations. The correlation between the HLA specificities of the antisera and the aggregating effect on platelets carrying the corresponding antigens was significant (P = 0.011). Because the platelet aggregation test is being used for screening of circulating immune complexes, falsely positive reactions caused by HLA antibodies must be eliminated by adequate control experiments.

Antibody Specificity↗
PubMed1977

Lack of measurable complement fixing antibodies against viral antigens.

A serological and clinical study was performed to find the common features of 130 patients without antibodies against 11 or more different antigens in the complement fixation (CF) test. These patients (=1.6%) were discovered during hte screening of 8,021 adult patients. Rheumatoid factor(s) (RF) were found in the sera of 113 of the patients. In the remaining 17 patients no common serological or clinical markers were found. Myeloma M-components were found in three cases. The lack of measurable CF antibodies in RF positive cases was apparently due to the inhibitory effect of RF(s) in the CF test. This was indicated by a positive reaction in CF after centrifugal separation of IgM and IgG fractions and also by the detection of antibodies using immunodiffusion method. Possible immune complexes were sought using the platelet aggregation test, which was positive for the sera of 47 (=37%) of the patients. The clinical diagnosis of the 130 CF-nonreactors was rheumatoid arthritis (RA) (ARA criteria) in 23 cases and pulmonary diseases in 65 cases. In a comparison group of equal size there were only 3 RA patients and 15 with pulmonary disease. RA was thus found in 20% of the RF positive CF-nonreacting patients. In the comparison group of 52 RA patients 8 CF-nonreactors were found (=15%). This suggests that the effect of RF(s) from RA patients in CF reaction varies greatly.

Adult↗
PubMed1977

Interactions of immune complexes and platelets in rabbits immunized with hapten-carrier conjugates.

The thrombopenic effects of immune complexes were studied in 32 rabbits, immunized actively with aspirin. The test animals were exposed to hapten-protein conjugates with a hapten density ranging from 0.6 to 38, and to pure hapten. The resulting thrombopenia and leucopenia correlated closely with the presence of immune complexes in the serum as detected by the platelet aggregation sedimentation pattern test (P1.A.). This platelet-aggregation activity sedimented mainly in the 19S fraction. The effects induced by polyvalent antigens where dose-dependent and could be modified by a prior injection of aspirin. Expectedly, monovalent antigens were only marginally effective.

Animals↗
PubMed1977

Antibodies to human coronavirus OC43 measured by radial haemolysis in gel.

An application of the haemolysis-in-gel (HIG) technique was developed to quantitate antibodies against the human coronavirus OC43. Preinfection and convalescent sera from two patients with verified OC43 infection showed a significant increase in antibody titres measured by HIG as well as by haemagglutination-inhibition (HI). 241 of the other 306 sera tested (80%) caused radial haemolysis in gels containing viral antigen-sensitized erythrocytes and complement. No haemolysis was seen in gels prepared with unifected material. Correlation of the diameter of the haemolysis ring to the respective HI titre was highly significant. However, 62 sera (20%) with HI titres between 8 and 320 were negative in the HIG. Attempts to show that these sera contained nonspecific inhibitors of haemagglutination were unsuccessful. OC43 HI and HIG probably measure different antibody ppulations.

Antibodies, Viral↗
PubMed1976

Determination of mumps and influenza antibodies by haemolysis-in-gel.

A stabilized modifications of the single radial haemolysis-in-gel (HIG) technique was developed. Crude mumps or influenza virus preparations were coupled to erythrocytes with CrCl3 and mounted in agarose gel containing diluted guinea pig serum. Serial serum samples taken from 204 conscripts before and after vaccination with a killed mumps vaccine were analysed with the HIG technique. The results showed that the sensitivity of the HIG test in detecting seroconversion was higher than that of the conventional haemagglutination inhibition test (HI). The correlation between the diametre of the rings of haemolysis and antibody titres measured by the standard complement fixation (CF) technique was fairly good. 62 pairs of sera from patients with suspected influenza were tested by both the HIG-method and the conrentional CF and Hi techniques. The HIG test appeared to be as sensitive as the common methods in detecting increases in antibody levels. The HIG test was found to be insensitive to the nonspecific inhibitors of haemagglutination and aggregated IgG while it was slightly affected by the rheumatoid factor. These features together with the technical ease of performing the test, make the HIG test superior to the conventional HI and CF techniques in mumps and influenza diagnostics.

Antibodies, Viral↗
PubMed1976

Blocking effect of rheumatoid factor on the in vitro cytotoxicity of lymphoid cells from carcinoma patients.

Human cryo-IgM rheumatoid factor (RF) preparations blocked the tumor-specific in vitro cytotoxicity of ovarian or bladder carcinoma patients' lymphoid cells in microcytotoxicity assays. The effect was mediated by pretreatment of the effector cells. Cryo-IgM RF free of detectable IgG blocked in a dilution-dependent manner, and immunosorbent purification of contaminating IgG from another preparation did not abrogate the blocking effect. Control IgM preparations lacking RF activity did not block the cytotoxicity, and normal human serum preincubation of the RF preparations rendered them inactive, indicating that the blocking effect was due to the anti-IgG activity of the RF.

Cryoglobulins↗