Paavo Väänänen

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Two tests were introduced recently for assessment of the avidity of rubella immunoglobulin antibodies. In the quantitative test--avidity-enzyme linked immunosorbent assay (ELISA)--IgG antibodies obtained from individuals shortly after primary infection with rubella virus are distinguished from those with past immunity by their antigen-elution(More)
—A voltage-controlled oscillator (VCO) based on double cross-coupled multivibrator structure with a center frequency of 4.3 GHz and a tuning range of 2 GHz has been designed and implemented in standard 0.35-m BiCMOS technology. The measured phase noise is 113 dBc/Hz at 600-kHz offset frequency from the carrier. The VCO draws 14.6 mA from the 2.5-V supply.
Semliki Forest, Sindbis and rubella viruses can fuse erythrocytes from several different species. Large fusion vesicles consisting of tens to hundreds of red blood cells were seen under optical conditions. For the haemagglutination and cell fusion to occur the adsorption of virus and further incubation had to be carried out at pH 5.8. Haemagglutination took(More)
—This brief presents a fully monolithic voltage-controlled os-cillator (VCO) based on double cross-coupled multivibrator architecture with a speed enhancing-load designed and implemented on a standard 0.35-m BiCMOS process. The tuning range achieved is greater than 1.6 GHz with a center frequency of 3.6 GHz and the measured phase noise is 98 2 dBc/Hz at an(More)
Sera from 30 infants with suspected chlamydial pneumonitis were studied by enzyme immunoassay (EIA) with three antigens: reticulate bodies (RB), purified major outer membrane protein ( MOMP ) of Chlamydia trachomatis strain L2, and purified lipopolysaccharide from Re mutants of Salmonella (Re LPS), which shows complete cross-reaction with chlamydial(More)
Purified preparations of Semliki Forest (SFV) and Sindbis virus haemolyse red blood cells from several species of animals and birds. The optimal haemolysis by SFV was obtained at pH 5.8 with 1-day-old chick erythrocytes incubated at room temperature. Considerable variation in haemolytic activity was observed between different virus preparations purified by(More)
A novel immunochemical test, "Hemolex," is characterized and compared with three guaiac tests: "Hemoccult" (Smith-Kline, U.S.A.), "Hemofec" (Boehringer Mannheim, F.R.G.), and "Fecatwin Sensitive" (Labsystems, Finland). We tested 191 stool specimens from patients, 144 from healthy persons. The sensitivity of Hemolex was 0.6 mL of blood per 100 g of stool. It(More)