[1] UNIV HELSINKI, CENT HOSP, DEPT MED, SF-00290 HELSINKI 29, FINLAND
[2] UNIV TURKU, DEPT MED MICROBIOL, SF-20520 TURKU 52, FINLAND
[3] UNIV PENN, DEPT MED, PHILADELPHIA, PA 19104 USA
[4] RHEUMATISM FDN HOSP, SF-18120 HEINOLA, FINLAND
[5] UNIV TURKU, CENT HOSP, DEPT MED, SF-20520 TURKU 52, FINLAND
[6] UNIV TURKU, CENT HOSP, DEPT SURG, SF-20520 TURKU 52, FINLAND