Detection of HPV in cytologically normal cervices: We have detected by filter in situ hybridization human papillomavirus (HPV) types 6/11, 16 and 18 DNA sequences in 6(0.9%), 12(1.8%) and 4(0.6%), respectively, out of 666 swab specimens from normal cervices (mean age; 49.1 years). The positive rate for HPV 16 and HPV 18 was significantly lower compared with 27.1%(26/96) of CIN and 48.4%(15/31) of cervical cancers. HPV DNA occurred more often in women under 50 years old than in those 50 years old or older (5.1% versus 1.0%). 2. Detection of HPV in cervical intraepithelial neoplasia (CIN): Eighty nine patients with CIN I-III were examined by Southern blot analysis with HPV 11, HPV 16 and HPV 18 DNAs in stringent conditions (Tm -18 degrees C) and with HPV 16/18 mixed probe in relaxed conditions (Tm -37 degrees C). We found HPV 11, HPV 16, HPV18 and other types of HPV in 0%(0/37)/2.7%(1/37)/2.7% (1/37)/16.2%(6/37) of CIN I, 0% (0/11)/9.1%(1/11)/0%(0/11)/45.5%(5/11) of CIN II and 0% (0/41)/26.8%(11/41)/2.4%(1/41)/24.4%(10/41) of CIN III. 3. Detection of HPV in cervical carcinomas: One hundred sixty seven cervical carcinomas and 6 metastatic tumors from cervical carcinomas were examined by Southern blot analysis with HPV 16 and HPV 18 DNAs in stringent conditions (Tm -18 degrees C). HPV 16 and HPV 18 were found in 35.3% (59/167) and 7.2%(12/167), respectively. The incidence of HPV 16/18 was higher in the patients under 60 years old (55.1% [27/49]). HPV 18 was detected more often in adenosquamous carcinomas and adenocarcinomas (31.8% [7/22]) than in squamous cell carcinomas (3.4% [5/145]). Five out of 6 metastatic tumors were positive for HPV 16 or HPV 18. 4. Physical state of HPV DNA in CIN and cervical carcinomas: The physical state of HPV 16 and HPV 18 DNAs was determined by electrophoresis after digestion with uncut and single-cut enzymes and two-dimensional electrophoresis after digestion with uncut enzyme. Three out of 3 CIN had only free episomal HPV DNA. HPV 16 DNA was existed as free episomal DNA in 4, as free episomal DNA and integrated DNA in 7, as integrated DNA in 8 out of 19 cervical carcinomas. HPV 18 DNA was integrated into the host cell genome in 3 out of 3 cervical carcinomas.(ABSTRACT TRUNCATED AT 400 WORDS)