K L Ebi — Page 2 | Search PubMed

PubMed1996

Evidence against tailstrings increasing the rate of pelvic inflammatory disease among IUD users.

A meta-analysis was conducted to determine whether the presence of an IUD tailstring is associated with increased rates of pelvic inflammatory disease among IUD users. Included were seven clinical studies that compared the same IUD with and without a tail, and fifteen clinical studies that compared two similar copper IUDs that differed in the polymer used for the tailstring (polypropylene versus polyethylene). No increase in PID rates was found among users of IUDs with versus without a tail (RR = 1.2, 95% confidence interval 0.6-1.7), or among users of copper IUDs with different tailstring materials (polypropylene vs. polyethylene, RR = 0.9, 95% confidence interval 0.4-1.5). These findings support the hypothesis that the presence of a tailstring does not increase the rate of PID among users of IUDs.

Adolescent↗

PubMed1996

Exposure to 60 Hz magnetic fields does not alter clinical progression of LGL leukemia in Fischer rats.

Associations between exposure to 60-Hz magnetic fields in residential and occupational environments and the incidence of leukemia and other cancers has been suggested by the results of a number of epidemiology studies. To address these potential associations, a study has been conducted to determine if 60-Hz magnetic fields can alter the clinical progression of leukemia. In the large granular lymphocytic (LGL) leukemia model, spleen cells from aged leukemic rats were transplanted into young, male Fischer 344 rats, producing leukemia in a relatively short period. A total of 72 animals were randomly assigned to four treatment groups (18/group) as follows: (1) 10 G; (2) sham exposed (null energized field) (approximately 20 mG); (3) ambient controls (<1 mG); and (4) positive controls (5 Gy whole body irradiation from Cobalt-60, 4 days before initiation of exposure). At the initiation of exposure or sham-exposure, all rats were injected (i.p.) with 2.2x10(7) fresh, viable, LGL leukemia cells. The magnetic fields were activated for 20 h per day, 7 days per week; all exposure conditions were superimposed over the natural ambient magnetic field. Eighteen rats from each treatment were bled at weeks 0, 2, 4, 5, 6, 7, 8 and 10 to monitor, in the same set of animals, the clinical progression of the LGL disease and survival of the animals. Peripheral blood hematological changes were monitored to evaluate the progression of the leukemia. In general, no significant or consistent differences were detected between the magnetic field exposed and the ambient field control groups, although some inconsistent and random differences were occasionally observed. These data indicate that the 10 G magnetic fields did not significantly alter the clinical progression of LGL leukemia in Fischer 344 rats.

Animals↗