High-Field Dynamic Nuclear Polarization for Solid and Solution Biological NMR.

Dynamic nuclear polarization (DNP) results in a substantial nuclear polarization enhancement through a transfer of the magnetization from electrons to nuclei. Recent years have seen considerable progress in the development of DNP experiments directed towards enhancing sensitivity in biological nuclear magnetic resonance (NMR). This review covers the applications, hardware, polarizing agents, and theoretical descriptions that were developed at the Francis Bitter Magnet Laboratory at Massachusetts Institute of Technology for high-field DNP experiments. In frozen dielectrics, the enhanced nuclear polarization developed in the vicinity of the polarizing agent can be efficiently dispersed to the bulk of the sample via (1)H spin diffusion. This strategy has been proven effective in polarizing biologically interesting systems, such as nanocrystalline peptides and membrane proteins, without leading to paramagnetic broadening of the NMR signals. Gyrotrons have been used as a source of high-power (5-10 W) microwaves up to 460 GHz as required for the DNP experiments. Other hardware has also been developed allowing in situ microwave irradiation integrated with cryogenic magic-angle-spinning solid-state NMR. Advances in the quantum mechanical treatment are successful in describing the mechanism by which new biradical polarizing agents yield larger enhancements at higher magnetic fields. Finally, pulsed methods and solution experiments should play a prominent role in the future of DNP.

Evaluation of surgical therapy by cost-benefit analysis.

Cost-benefit analysis (CBA) is described briefly, emphasizing the contribution this technique can make in justifying health care programs vying with other costly public programs for support. Costs and benefits of two surgical diagnostic techniques are outlined briefly as illustrations of the analysis. The first analyzes routine intraoperative cholangiography indicating the slight benefits that accrue from its use in terms of mortality and hospital expense. A more complicated example is an analysis of a policy of universal annual uterine cervical smears in asymptomatic women for cancer prevention where, granted the assumptions of the model, the costs minus the benefits of the program are estimated to be $565,000/beneficiary/year. The average beneficiary will gain 22 years of life at an average cost/year of about $26,000. The two examples are presented primarily as illustrations of a methodology which is being applied widely in medicine and public policy planning. Second, the marshalling of facts in CBA of a policy of annual uterine smears is of interest to those concerned with the justification of this screening procedure.

Corpus luteum hemorrhages complicating chronic anticoagulation.

A 29-year-old patient with prosthetic replacement of two cardiac valves who was receiving chronic anticoagulation therapy presented with sequential corpus luteum hemorrhages. The problems of reproductive system hemorrhage from chronic anticoagulation therapy are discussed, as well as the specific problemsof women of reproductive age with heart valve replacements. Issues and therapy are considered.

Cytology of 575 young women with prenatal exposure to diethylstilbestrol.

The vaginal and cervical cellular changes encountered in 575 postpubertal females exposed prenatally to diethylstilbestrol (DES) were compared with those of an unexposed population with particular reference to the role of cytology in the detection of vaginal adenosis and cervical ectropion (erosion). Several methods of obtaining specimens were utilized, the most effcacious of which was scraping of the vagina, especially the fornices, and the portio vaginalis of the cervix. With this technic, columnar cells of the mucinous type and metaplastic squamous cells were observed in 34% of the vaginal scrapes and 54% of the scrapes of the cervical portio. A higher incidence was apparent among those patients in whom iodine staining of the vaginal mucosa was abnormal or vaginal adenosis was proven by biopsy. Moderate to severe dysplasia of the squamous cells or atypical glandular cells were found in 1% of the exposed subjects. This study indicates that the presence of mucinous columnar or metaplastic squamous cells in vaginal scrapes is suggestive of vaginal adenosis but that vaginal cytology cannot be considered a uniformly reliable screening technic for detecting the presence of this disorder.

Vaginal epithelial changes in young women enrolled in the National Cooperative Diethylstilbestrol Adenosis (DESAD) project.

Initial clinical findings are reported for the 3339 young women enrolled in the Diethylstilbestrol Adenosis (DESAD) project. Changes in the vaginal mucosa (VEC--vaginal epithelial changes), which were detected by colposcopy or iodine staining, occurred in 34% of 1275 participants identified by review of prenatal records 59% of participants who themselves requested entry into the project, and 65% of participants referred by a physician. Analysis of data on the 298 women who were identified by record review and whose prenatal records contained complete information about drug exposure indicated that VEC is most closely associated with the timing of the onset of intrauterine exposure to diethylstilbestrol (DES), total dose, and length of exposure. Frequency of VEC was also found to decrease with age. No instances of severe dysplasia, carcinoma in situ, invasive squamous cell adenocarcinoma, or clear cell carcinoma were observed among the women identified by record review.

Comparison of histologic and colposcopic findings in DES-exposed females.

A study was undertaken to evaluate the histologic alterations associated with two of the most abnormal colposcopic findings, mosaicism and punctation, that are commonly found in the vaginas and cervices of young women who have been exposed prenatally to diethylstilbestrol (DES). Four-fifths of 215 biopsy specimens from 171 exposed subjects with mosaicism or punctation disclosed metaplastic squamous epithelium, the presence of which is thought to reflect the repair of vaginal adenosis and cervical ectropion. Hyperkeratosis was observed in one-fifth of the specimens and was more frequent in lesions colposcopically graded I than II. Mild dysplasia was encountered in only one specimen. The findings indicate that the presence of squamous cell dysplasia cannot be predicted by the finding of Grade I or II mosaicism or punctation in the DES-exposed female despite the fact that these abnormal colposcopic patterns are associated with dysplasia in about 10% of cases when encountered in the cervix of the unexposed woman.

Squamous cell dysplasia and carcinoma in situ of the cervix and vagina after prenatal exposure to diethylstilbestrol.

Squamous cell abnormalities of the vagina and cervix were evaluated in 1424 women exposed to diethylstilbestrol (DES) in utero. The prevalence of dysplasia was 2.1% and the incidence 0.85/100 person-years of followup. The dysplastic epithelial changes were almost always mild in women with no prior history of dysplasia and was slightly more frequent in the cervix than the vagina. Severe dysplasia and carcinoma in situ (CIS) were encountered only in those subjects specifically referred because of those abnormalities. The most common problem in the diagnosis of these squamous cell changes was the misinterpretation of mature and immature metaplastic cells for dysplastic squamous cells. Discordance between biopsy and cytology was common-place in the detection and followup of dysplasia, especially when it was mild. There were no instances in the study where cytology and biopsy samples from the vagina were both abnormal concurrently. Colposcopically directed biopsies did not increase the frequency of confirmation of cytologic findings. These data suggest that both cytology and biopsy of abnormal segments of the vagina and cervix remain an integral part of the examination of the DES-exposed female during long-term follow-up studies.

Design and preliminary observations of National Cooperative Diethylstilbestrol Adenosis (DESAD) Project.

The National Cooperative Diethylstilbestrol Adenosis (DESAD) Project has completed the major portion of its enrollment phase with the examination of more than 3000 daughters of women taking synthetic nonsteroidal estrogens (denoted DES) during pregnancies occurring from the early 1940s to the mid-1960s. The aims of the Project are to fill urgent needs for information on the prevalence and incidence of structural and epithelial abnormalities or neoplastic changes and their complications in these young women. Participants are grouped by mode of entry as identified by prenatal record review (40.1%), documented as DES-exposed but walking in (25.1%), or referred (22.8%) to the DESAD Project for examination, and not documented as exposed but having gynecologic abnormalities typical of those associated with DES exposure (12.0%). This study cohort, in part having paired controls, will be examined annually for at least 5 years. Details of the design and selected preliminary findings are reported.

Menstrual history of young women exposed in utero to diethylstilbestrol.

The menstrual histories of 218 patients exposed in utero to diethylstilbestrol (DES) were compared with those of 158 control subjects. No significant differences were revealed in the complaint of menstrual irregularities at either the initial or follow-up examination. Age at menarche was the same in both groups, and was the same as found in the United States as a whole. These findings differ from the report of a controlled trial in Chicago which suggests that there is a specific pattern of oligomenorrhea associated with DES exposure.

Hyperparathyroidism during pregnancy.

Hyperparathyroidism during pregnancy is clearly associated with an increased incidence of neonatal morbidity and mortality. Although it is impossible to define the precise incidence of this entity, we believe that its occurrence will be seen more frequently with the increasing numbers of female patients who have successfully received renal transplants and with the routine determination of serum chemistries in the nontransplanted pregnant patient. A review of case reports since 1962 of women known to be hyperparathyroid during pregnancy revealed 80 per cent of these pregnancies to be complicated by neonatal tetany, death, or abortion. This review substantiates Ludwig's earlier report [1], which noted a 50 per cent incidence of neonatal complications despite the advances of prenatal and postnatal medical care. There have been only eight reported cases in which parathyroid resection was performed during pregnancy. Successful operation dramatically reduced the incidence of neonatal complications. An adaptive normocalcemic hyperparathyroidism occurs routinely during pregnancy. However, in the hypercalcemic hyperparathyroid pregnancy, transplacental passage of calcium leads to a profound hypercalcemia in the fetus. Since the fetal parathyroid glands are functionally responsive, parathyroid suppression is thought to occur in utero due to high calcium levels. This can lead to neonatal tetany or perhaps permanent neonatal hypoparathyroidism. When a patient presents with significant hypercalcemic hyperparathyroidism during pregnancy, we suggest that an explorative parathyroid operation be performed during the second trimester of pregnancy. After delivery, the baby's course should be carefully monitored with frequent calcium determinations. Cow's milk or other formula feedings high in phosphate content should be avoided in favor of feedings with a calcium:phosphorus ratio similar to that of human milk.

Ectopic pregnancy: incidence and review of determinant factors.

The incidence of ectopic pregnancies has been expressed in various ways that are not comparable and provide widely differing estimates due to individual definitions of the denominator. Population-based data are presented based on a count of all ectopic pregnancies reported in short stay hospitals in Maine, Rhode Island, and Vermont in 1974-1976. The incidence is 40 per 10(5) female population age 14-44 and is more consistent across 80 hospital service areas than other gynecological diagnoses. The data do not reveal an increasing incidence over these 3 years in contrast to national surveys based on a longer period of observation. A review of determinant factors for ectopic pregnancy is presented, and current theories concerning the etiology, changes in contraceptive practices, innovations in sterilization procedures, or advances in diagnosis do not appear individually or collectively to explain the increasing incidences reported by others. Further basic biologic and epidemiologic research is needed to determine causes and trends in this principal cause of first trimester mortality among pregnant women.

Menstrual history and fecundity of women exposed and unexposed in utero to diethylstilbestrol.

Sequential examination and interview of diethylstilbestrol-exposed (DES-exposed) and -unexposed women verified that DES exposure has no effect on age at menarche and indicated no differences in the age at first coitus, pregnancy and live birth. Analysis of variance indicated that there is an age-related increase in oligomenorrhea in DES-exposed women as compared to unexposed women that disappears as the patients reach their late 20s. Prospective data collection is required to substantiate this finding. There appears to be no substantial effect of in utero exposure to DES on women's ability to conceive.

PIP: Sequential examination and interview of 349 women exposed to diethylstilbestrol (DES) and 375 women unexposed to the drug verified that DES exposure has no effect on age at menarche and indicated no differences in the age at 1st coitus, pregnancy, and live birth. Records of the women in the DES Adenosis project were studied to determine DES dosage and timing, but starting date and total amount prescribed could not always be determined accurately. Estimates indicate that about 1-2% of pregnant patients in the late 1950s and 1960s were exposed to the drug. As many as 30% of mothers were unaware that DES was given to them during pregnancy. The women were asked about marital status, age at menarche, menstrual history, pelvic inflammatory disease (PID), operations, birth control, and pregnancy experience. Analysis of variance indicated that there is an age-related increase in oligomenorrhea in DES-exposed women as compared to unexposed women that disappears as the patients reach their late 20s. Of 133 exposed women, 59 (44%) had induced abortions, and of 162 unexposed women 93 (57%) had induced abortions. DES-exposed women used oral contraceptives (OCs) but not as frequently or extensively as their unexposed counterparts. Age at first coitus was 19.33 +or-2.95 years for the exposed and 18.89 +or-2.62 years for the unexposed, showing no significant difference. In a higher percentage of DES-exposed women the cause of the couple's infertility was undetermined. 44 (12.6%) of the exposed and 42 (11.2%) of the unexposed women had dilatation and curettage (D and C) for some reason other than abortion. There appears to be no substantial effect of in utero exposure to DES on women's ability to conceive. Whether or not exposure to DES has specific physiological effects on reproductive function, exposed women may alter their sexual and reproductive behavior in anticipation of those effects as well as experiencing them.

Contraception.

PIP: The number of women using contraception is increasing. There are today several methods of contraception available. Behavioral methods of contraception include coitus interruptus, not ideal for psychological reasons, the rhythm method, and the cervical mucus method; they all involve periodic sexual abstinence and need extended patient education. Barrier methods include the condom, the vaginal diaphragm, the cervical cap, and all types of spermicidal agents used locally; barrier contraception can be 97% effective when properly used. Effectiveness of the IUD is 90-99%; many women experience excessive bleeding and/or expulsion of the device. IUDs are not indicated for women with vaginal infections and must be removed if pregnancy occurrs. IUDs are indicated in multiparous, healthy women. Oral contraception is the most effective way to control fertility despite the well documented side effects. Contraceptive pills contain different doses of estrogen and progesterone, and must be prescribed only after careful medical examination. Postcoital contraception can be obtained either with ethinyl estradiol and norgestrel or with diethylstilbestrol; side effects are numerous. In 1976, sexual sterilization was the 3rd most frequent surgical procedure in the U.S. The procedure must be considered a permanent one despite the increasing number of reversal successes; psychological side effects are possible but rare. Induced abortion is used as contraception and is safest when performed during the earlier stages of pregnancy. Risk of maternal death is about the same as for delivery, or 12/100,100. Methods of abortion vary according to the length of gestation. It has been suggested that barrier methods of birth control and using abortion for failures is currently the safest approach to contraception. The choice of the best contraceptive method must be made by a doctor in accordance with the clinical history and the life style of the patient, and especially taking into consideration age and smoking habits.^ieng

Transplacental carcinogens.

Cancer can metastasize to the placenta and to the fetus, and it may arise in man without familial predisposition in fetal or early postnatal life. Carcinogens administered to the mother can induce cancer in the human fetus and experimental animals. Many potential carcinogens tend to act as abortifacients and teratogens as well as carcinogens. Carcinogens administered to mothers can be dispersed by all their metabolic pathways and can be transferred transplacentally. In each exposed fetus, further metabolic pathways, or absence therof, as well as the individual gene makeup, influence the expression of an agent's potential. In the future, experimental evidence defining the pathways of carcinogenesis in adults will provide clearer insight into how cancers arise. This will be most helpful in unraveling the more complex issue of transplacental carcinogens.