Precision measurement of the 6He half-life and the weak axial current in nuclei.

Studies of 6He beta decay along with tritium can play an important role in testing ab initio nuclear wave-function calculations and may allow for fixing low-energy constants in effective-field theories. Here, we present an improved determination of the 6He half-life to a relative precision of 3×10(-4). Our value of 806.89±0.11(stat)(-0.19syst)(+0.23) ms resolves a major discrepancy between previous measurements. Calculating the statistical rate function we determined the ft value to be 803.04(-0.23)(+0.26) s. The extracted Gamow-Teller matrix element agrees within a few percent with ab initio calculations.

Prevalence of human papillomavirus infection in women attending a sexually transmitted disease clinic.

The purpose of this study was to determine the prevalence of infection due to human papillomavirus (HPV) types of high and intermediate oncogenic risk, which was most frequently associated with uterine cervical neoplasia. The subjects were 236 prostitutes who visited a sexually transmitted diseases (STD) clinic in a metropolitan area in 1998. Another 95 women who visited a university hospital were selected as a normal control group. A swab sample collected from the uterine cervix and external os was subjected to hybrid capture assays for low-oncogenic-risk HPV types (HPV A; including types 6, 11, 42, 43 and 44) and high- and intermediate-oncogenic-risk HPV types (HPV B; including 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59 and 68). Chlamydia trachomatis and Neisseria gonorrhoeae. Fisher's exact test was used for statistical analyses. Among the microorganisms tested, the positive rate for HPV B was the highest both in the women attending the STD clinic (STD group) and in the control group. The positive rate for HPV B in the STD group was 47.5% (112 of 236), and this was significantly higher than the 5.3% (5 of 95) in the control group (p < 0.0001). These findings suggest that HPV examination is recommended for women who visit an STD clinic to assess the future risk of cervical neoplasia.

Usefulness of hybrid capture HPV DNA assay as a diagnostic tool for human papillomavirus infection.

The purpose of this study was to determine the usefulness of the hybrid capture HPV DNA assay, a new nonradioactive solution hybridization assay, as a diagnostic tool for human papillomavirus infection. In a total of 234 women, samples for the hybrid capture assay and polymerase chain reaction (PCR) assay were obtained by wiping a swab across the cervix and external os (either a Dacron swab or a cotton swab was used). The papanicolaou smear test (Pap smear) was carried out on all 234 women. Tissue samples for biopsy were obtained by colposcopy from 118 of the women. Fisher exact test was used for statistical analyses. Using the hybrid capture assay, HPV DNA of high- and intermediate-oncogenic-risk type was detected in 23 (13.9%) of 166 samples from women with Pap smear Class I or II, and 48 (70.6%) of 68 with Pap smear Class III, IV or V (p < 0.0001). The HPV DNA type was detected in 18 (29.0%) of 62 samples from those with no evidence of cervical intraepithelial neoplasia and 44 (78.6%) of 56 with cervical intraepithelial neoplasia or squamous cell carcinoma (p < 0.0001). Correlation of the test results between the hybrid capture test and PCR was determined by using the 217 samples in which both test results were available (PCR test results were not obtainable in 17 samples. When PCR is set as a gold standard, the hybrid capture test has high sensitivity (74.6%) and specificity (92.7%). These findings suggest that the hybrid capture HPV DNA assay is a useful method for diagnosing HPV infection in the clinic.

[Significance of the detection of serum specific IgA and IgG antibodies to Chlamydia trachomatis in the epidemiological survey, diagnosis and therapeutic effect on chlamydial infection in women].

In a study to evaluate the epidemiological status of Chlamydia trachomatis (C. trachomatis) infections in the OB/GYN field, we performed an indirect enzyme immune assay, measuring serum specific IgG and IgA. 1) Among 1,812 cases (0-68 years old), antibody positive rates for IgG and IgA were 29.7% and 11.2%, respectively. The first peak was observed in an age group under 1 year old, representing birth canal infections and the second one in a 20-24 age group showed a certain relation to STD. 2) The C. trachomatis IgG and IgA antibody positive rates in the antigen positive group (139 cases) were significantly higher (p less than 0.01) than in the antigen negative group (792 cases). 3) In the antigen positive group (139 cases), the positive IgG rate was high (78.8-90.9%) but it did not show any clear differences among the following groups: PID, cervicitis, pregnancy and infertility. However, the positive IgA rate in peritoneal antigen positive PID showed a significantly higher positive rate (100%) than other groups such as cervicitis (39.4%), pregnancy (37.8%) and infertility (45.5%). 4) Following oral administration of antibiotics, the C. trachomatis antigen became negative in almost all cases, while IgG decreased or became negative only in cases of initial infection. IgA decreased or became negative in the following cases: initial infection, low titer cases before treatment, cases treated many times and comparatively young patients with acute infections. Consequently, the immunoassay of C. trachomatis serum antibody appeared to be valuable for epidemiological surveys, for defermining the status of the infection and the effect of treatment.