IUD litigation: the Planned Parenthood experience.

PIP: This review of the IUD litigation experience of Planned Parenthood in the U.S. from 1977-1988 involved 18 injuries allegedly caused by the plaintiff's use of an IUD. These 18 IUD cases represent 9.8% of the total malpractice lawsuits involving Planned Parenthood in the period. 7 were dismissed, 8 were settled, 1 was decided in favor of the defense, and 2 were decided in favor of the plaintiff. While the disposition of these cases is similar to the overall malpractice experience nationally, it is unusual in that twice as many verdicts were for the plaintiff. It is likely that the public perception that IUDs are dangerous made it difficult to select an impartial jury. Pelvic inflammatory disease (PID) was the most common alleged injury, 15 of 18. Even though the scientific evidence predicts otherwise, 15 of the 16 cases of PID occurred over 4 months after insertion. 8 of 15 cases involves Copper-7 IUDs, 4 Dalkon shields, 1 a Progestasert, and 2 Saf-T-Coils. The other 2 cases were 1 uterine perforation and 1 pregnancy. Of the 8 cases that were settles, the mean payment was $20,912, and the median $10,000. These payments are about 25% higher than average non-IUD cases. Payments by insurance companies averaged $21,644 in the late 1970s for IUD claims. In jury cases involving IUDs and Planned Parenthood, the average jury award was $50,000. It is recommended that providers take care especially to comply fully with an IUD manufacturer's protocol, and obtain full and complete informed consent with documentary proof to decrease the possibility of an adverse outcome in potential litigation.^ieng

Stoichiometry of lac repressor binding to nonspecific DNA: three different complexes form.

The stoichiometry of lac repressor binding to nonspecific DNA was investigated by three different techniques. Four molecules of the fluorescent probe 5,5'-bis(8-anilino-1-naphthalenesulfonate) [bis(ANS)] bind to each repressor subunit with an average dissociation constant of 20 microM. Nonspecific DNA displaces most of this bound bis(ANS), reducing the fluorescence. Titrations of repressor with nonspecific DNA monitored with high [bis(ANS)] (5-15 microM) had end points at 8 base pairs per repressor. Lower [bis(ANS)] (0.1-1 microM) resulted in end points at either 15 or 26 base pairs per repressor, depending on the ionic strength. These end points correspond to complexes containing approximately one, two, or four repressors per 28 base pairs. Boundary sedimentation velocity experiments with saturating amounts of repressor revealed that five repressors can bind to 28 base pairs. By monitoring the circular dichroism as DNA was added to repressor, the sequential appearance of complexes containing approximately four, two, and one repressors per 28 base pairs was observed. The inability of repressor cores or iodinated repressor to bind to complexes containing one or two repressors per 28 base pairs implies that all of the repressors directly contact the DNA in the complex containing four repressors per 28 base pairs. It is proposed that while two subunits of each repressor contact the DNA in complexes containing one or two repressors per 28 base pairs, only one subunit of each repressor contacts the DNA in the complex with four repressors per 28 base pairs. These results suggest a novel mechanism for the one-dimensional diffusion of repressor along DNA.

lac Repressor cysteine-140 reacts selectively with a fluorescent probe bound to the core-headpiece interface.

The fluorescent probe N-[(iodoacetyl)amino]-ethyl]-5-naphthylamine-1-sulfonate (I-AEDANS) reacts selectively with Cys-140 of the lac repressor. The reasons for this selectivity were investigated. The ability of 8-anilino-1-naphthalenesulfonate and 5,5'-bis(8-anilino-1-naphthalene-sulfonate) to bind noncovalently to the interface between the core and headpiece regions of the repressor suggested that I-AEDANS might also bind to this interface and then react intramolecularly with Cys-140 nearby. Two observations strongly support this model. (1) The selectivity for Cys-140 was lost when the headpiece regions were removed from the repressor. The rate of reaction with Cys-140 relative to Cys-107 in the repressor was 13.5 +/- 1.4, from trypsin digestions of labeled repressor. This ratio decreased to 2.1 +/- 1.0 for the core protein. (2) Iodoacetamide, which lacks the naphthylaminesulfonate portion of I-AEDANS, showed little selectivity for Cys-140 in either the repressor or the core. Nonreactive analogues of I-AEDANS did not alter the reaction of I-AEDANS with the repressor, presumably because they bound too weakly. Decreasing the ionic strength from 0.61 M to 56 mM decreased the selectivity of I-AEDANS for Cys-140 in the repressor, suggesting that I-AEDANS is not bound to the repressor by ionic interactions. Decreasing the pH from 8.5 to 7.5 increased the selectivity for Cys-140 only slightly. Fluorescent probes attached to Cys-140 appear to be ideally located to report motions of the headpieces , relative to the core, that attend DNA binding.

lac repressor changes conformation upon binding to poly[dA-T)].

N-(Iodoacetylaminoethyl)-1-naphthylamine-5-sulfonate reacts with Escherichia coli lac repressor to selectively label cysteine-140 with the fluorescent N-(acetylaminoethyl)-1-naphthylamine-5-sulfonate group. The fluorescence intensity of this label decreases by 20% when labeled repressor associates with poly[d(A-T)]. Fifteen base pairs of poly[d(A-T)] per repressor tetramer are required to complete this decrease. Stopped-flow experiments have shown that the repressor undergoes at least two conformational changes as it binds to poly[d(A-T)], with half-lives of 5.0 +/- 1.2 msec and 3.5 +/- 1.0 sex. Quite likely, these conformational changes serve to strengthen the interaction of repressor with DNA.

Binding of recrystallized and chromatographically purified 8-anilino-1-naphthalenesulfonate to Escherichia coli lac repressor.

8-Anilion-1-naphthalenesulfonate (Ans), recrystallized from water as the magnesium salt, contains a fluorescent impurity representing 0.3% of the absorbance at 351 nm. This impurity can be removed by Sephadex LH-20 chromatography. The chromatographic and spectral properties of this impurity suggest that it is bis(Ans), a dimer of Ans. This bis(Ans) impurity makes a significant contribution to the fluorescence increment observed when lac repressor is added to recrystallized Ans. This occurs because bis(Ans) binds much more tightly to this protein than does Ans. The dissociation constant divided by the number of binding sites per subunit is 3.1 X 10(-6) M for bis(Ans); the corresponding value for Ans is greater than 1 X 10(-4) M. Because of their differing absorption spectra, the impact of this bis(Ans) impurity is especially large with excitation wavelengths above 400 nm. Users of recrystallized Ans should consider the potential consequences of this impurity whenever working with a protein to which Ans binds weakly.

Association of Escherichia coli lac repressor with poly[d(A-T)] monitored with 8-anilino-1-napthalenesulfonate.

The association of lac repressor with poly[d(A-T)] was monitored with the fluorescent prob 8-anilino-1-naphthalenesulfonate (Ans). Excess poly[d(A-T)] decreased the emission intensity of the repressor--Ans complex by 30%. Fluorescence titrations indicated that 33 +/- 4 base pairs were required to bind all of the repressor. Sedimentation studies indicated, however, that all of the repressor sedimented as a protein--DNA complex with as few as 10 to 15 base pairs per tetramer, even in the presence of Ans. These data are interpreted with two models: one where repressors bind to both sides of the DNA (Butler, A. P., et al. (1977) Biochemistry 16, 4757: Zingsheim, H.P., et al. (1977) J. Mol. Biol. 115, 565), the other where a double layer of repressors bind to a single side of the DNA. Removal of the amino-terminal regions from the repressor decreased the fluorescence from bound Ans by 77%. The amino-terminal fragments alone did not enhance Ans fluorescence.