A crossover pill study among Sudanese women

A crossover study from a standard-dose to a low-dose oral contraceptive was conducted in the Sudan. Reported side effects were very few, with a headache the most frequently reported. Switching to the other pill did not affect the rate of any side effects.

A randomized cross-over comparison of two low-dose oral contraceptives upon hormonal and metabolic parameters: I. Effects upon sexual hormone levels

The effect of a low-dose triphasic oral contraceptive (OC) containing ethinyl estradiol and levonorgestrel (EE/NG) upon serum levels of endogenous sexual hormones was compared to that of a preparation containing EE and desogestrel (EE/DG). Blood samples were taken on Day 6, 11, 21, and 28 of a control cycle and of the third cycle of treatment with either the EE/NG or EE/DG preparation (11 volunteers each). After a washout period of 3 months, the contraceptives were changed in a cross-over fashion. Blood samples were again taken on Day 6, 11, 21, and 28 of the third washout cycle and the third treatment cycle. There was no significant suppression of serum LH and FSH during treatment with EE/NG and EE/DG except on Day 21, while estradiol levels were significantly lowered. Similar to the gonadotropin concentrations, the estrogen levels showed great individual variations; although they were depressed in the majority of the women, there was a considerable stimulation of follicular activity in 36% of the women under EE/NG and 18% under EE/DG. Both EE/NG and EE/DG suppressed significantly serum progesterone, testosterone, and DHEA-S, while prolactin was unaffected. In three cases an escape ovulation seemed to have occurred, but no pregnancy was observed. The spottings (8/22 women) and breakthrough bleedings (6/22 women) did not correlate with the serum levels of estradiol. The results indicate that the suppression of gonadotropin secretion during treatment with low-dose OC is a time-dependent process which in some women may be at or below the threshold of safe ovulation inhibition.

Relationship of exercise, oral contraceptive use, and body fat to concentrations of plasma lipids and lipoprotein cholesterol in young women

To investigate the relationship of exercise and oral contraceptive use to plasma lipids and lipoproteins, a cross-sectional study was designed to compare lipid levels in 96 exercising and non-exercising women who used or did not use oral contraceptives. Exercisers had significantly lower plasma triglyceride concentrations and low-density/high-density lipoprotein ratios than non-exercisers after adjustment for differences in pill type distribution between groups. Women using progestin-dominant pills had significantly lower plasma triglyceride and high-density lipoprotein concentrations and significantly higher low-density/high-density lipoprotein ratios compared with women using estrogen/progestin-balanced pills. As body fat was significantly associated with both pill type and physical activity, it is unclear how much of these lipoprotein differences were due to body fat, exercise, or pill use. Regular physical activity together with reduced body fat partially compensated for plasma lipoprotein differences associated with oral contraceptive use.

Chromosomal abnormalities in the Kaiser-Permanente Birth Defects Study, with special reference to contraceptive use around the time of conception

Chromosomal abnormalities were studied in 33,551 abortions and births to women whose contraceptive histories had been recorded at their first antenatal visit in 1975-1977. Chromosome examinations were performed exclusively on clinical grounds. There were 45 de novo abnormalities detected (1.34/1,000); three of them were detected at amniocentesis. Trisomy 21 was observed in 27 cases (0.80/1,000), trisomy 18 in nine (0.27), other trisomies in three (0.09), and translocations or deletions in five (0.15). One case of triploidy and six cases of inherited abnormalities were detected. There were no significant racial variations. No increase in risk for chromosomal abnormalities was found among women who had used oral contraceptives prior to becoming pregnant or among women who experienced oral contraceptive breakthrough pregnancies. Two cases of trisomy 18 were observed among the 814 deliveries following oral contraceptive breakthrough conceptions (2.46/1,000), two cases of trisomy 21 occurred in 338 births following failures of rhythm contraception (5.92/1,000), and no cases of trisomy 21 or 18 among the 1,569 women using spermicides at the time of conception.

Ultrasonic visualization of NORPLANT subdermal contraceptive devices

This article describes the first use of ultrasound in locating in vivo NORPLANT subdermal contraceptive implants. Providing low dose, continuous contraception for women. the NORPLANT system utilizes Silastic tubing filled with levonorgestrel. The progestin-filled tubing is not radiopaque. Anticipating the large scale use of NORPLANT subdermal implants, the potential, but rare problem of difficult localization of an implant is recognized. The feasibility of using ultrasound for the painless and safe localization of NORPLANT rods and capsules is demonstrated.

The hypercoagulable states

Patients are considered to have hypercoagulable states if they have laboratory abnormalities or clinical conditions that are associated with an increased risk of thrombosis (prethrombotic states) or if they have recurrent thrombosis without recognizable predisposing factors (thrombosis-prone). The number of specific primary hypercoagulable states that are recognized is growing. These disorders are generally inherited abnormalities of coagulation in which a physiologic anticoagulant mechanism is defective: for example, antithrombin III deficiency, protein C and protein S deficiency, abnormalities of the fibrinolytic system, and dysfibrinogenemias. Secondary hypercoagulable states are generally acquired disorders in patients with underlying systemic diseases or clinical conditions known to be associated with an increased risk of thrombosis: for example, malignancy, pregnancy, use of oral contraceptives, myeloproliferative disorders, hyperlipidemia, diabetes mellitus, and abnormalities of blood vessels and rheology. The complex pathophysiologic features of these secondary hypercoagulable states are discussed, and a framework is provided for the laboratory investigation and systematic clinical approach to the patient.

Simplicity--the key to fruitful medical research

Medical research is here divided into two broad categories. The great majority of research is "complex" and includes all studies of intricate body mechanisms. A minority of research is "simple" and deals mainly with direct relationships between human environmental or life-style factors and disease incidence (or with analogous studies on animals). In addition, it includes studies of simple body mechanisms. Examples are provided to demonstrate that most of our medical knowledge of practical benefit derives from simple research. This is particularly the case in the area of prevention.

Immunogenicity and the vascular risk of oral contraceptives

Data concerning circulating immune complexes were obtained for women who had had a pulmonary embolism, myocardial infarction, or cerebral thrombosis, and for 224 healthy controls. In women with pulmonary embolism who had used oral contraceptives concentrations of circulating immune complexes were significantly higher than in healthy controls (regardless of oral contraceptive use), or in those with pulmonary embolism who had never used these preparations. Concentrations of circulating immune complexes were not raised in myocardial infarction, but these women had major risk factors for ischaemic heart disease. The group of patients with cerebral thrombosis without risk factors tended to have high concentrations of circulating immune complexes. The data provide some confirmation that immunological mechanisms may play a role in thrombotic episodes associated with oral contraceptives, especially when they occur in the absence of risk factors for vascular disease.

The patho-epidemiology of benign proliferative epithelial disorders of the female breast

Benign breast disease is associated with increased risk of subsequent breast cancer, especially when there is evidence of epithelial proliferation. There is no standard terminology for benign proliferative epithelial disorders (BPED), and this hinders direct comparisons between the various studies which have examined their pathology and their relationship to breast cancer. The present paper reviews previous classification schemes for BPED, and proposes an alternative system in which epitheliosis and blunt duct adenosis are the major features, the degree and pattern of the hyperplasias being graded separately. Adoption of this or a similar system as a standard should facilitate future comparative studies of these conditions. As BPED are apparently pre-malignant conditions, an understanding of their aetiology is important because it may help to elucidate the aetiology of breast carcinoma, and to open up avenues for its prevention. If BPED are precursors to breast carcinoma, then risk factors for BPED should also be risk factors for breast carcinoma. To date, in epidemiological studies of BPED, such concordance has not been demonstrated, as consistent risk factors for the BPED have not yet emerged. This may have resulted, at least in part, from differences in the histological categories included in the various studies. Therefore, collaboration between epidemiologists and pathologists may facilitate progress towards an understanding of BPED.

Cold promoted activation and factor XII, prekallikrein and C1-inhibitor

During incubation of plasma in the cold an amidolytic activity due to the kallikrein-alpha 2-macroglobulin complex appears in the plasma of about 40% of the women under hormonal contraception. The factor XII and prekallikrein activity are significantly increased 151.9% and 112.4% respectively in the cold promoted activation positive plasmas (CPA pos) whereas the activity of C1-inhibitor is decreased, 76%. The quotient of the product of the C1-inhibitor and alpha 2-macroglobulin values divided by the product of the FXII and prekallikrein values is significantly lower in the CPA pos plasma 0.49 than in CPA neg plasma 0.96 (p less than 0.05). These results alone do not explain the cold promoted activation, since a patient with a C1-inhibitor as low as 9% showed no increase of the amidolytic activity after a 24 hr incubation at 4 degrees C. However, the addition of purified C1-inhibitor to a CPA pos. plasma inhibits the cold activation. Heparin at a concentration of 0.5 IU/ml delays the appearance of the amidolytic activity.

Total cholinesterase in plasma: biological variations and reference limits

Factors affecting biological variation in total cholinesterase activity in plasma were studied in a population of 3372 apparently healthy subjects at least four years old. Determination of the dibucaine number, after inhibition of the activity by dibucaine, made it possible to specify the contributions of genetic and physiological characteristics to variations in the total activities by using a statistical method of segmentation. The main factors modifying plasma cholinesterase activity in males are genetic status (dibucaine number) and degree of overweight (subscapular skinfold). In females, hormonal status (puberty or menopause), genetic status (dibucaine number), and the use of oral contraceptives are the factors mainly responsible for the variations of plasma cholinesterase activity. These data allow us to propose reference limits for total plasma cholinesterase.