Reproductive and teratologic effects of electromagnetic fields.

The reproductive risks of electromagnetic fields (EMF) were evaluated based on an extensive review of the scientific literature pertaining to human epidemiologic studies, secular trend data, in vivo animal studies and in vitro studies, and biologic plausibility. The epidemiologic studies involving the reproductive effects of EMF exposures to human populations have included populations exposed to: (1) video display terminals (VDTs), and (2) power lines and household appliances. The clinical use of diagnostic MRI (magnetic resonance imaging) has been increasing, but there are few reports or studies of pregnant women or individuals of reproductive age who have been exposed to MRI, and whose reproductive performance has been evaluated. The population that has been studied most frequently are women exposed to VDTs, but their EMF exposures are extremely low and frequently are at the level of the ambient EMF in a house or office. The results of epidemiologic studies involving VDTs are generally negative for the reproductive effects that have been studied. Based on the number of studies, the exposure levels, and the fairly consistent results, it can be argued that VDT epidemiologic studies should no longer be given priority. There have been fewer studies concerned with the reproductive risks of power lines, electric substations, and home appliances. In some publications, positive findings for reproductive risks were reported, but the more consistent findings indicate that EMF, even at these higher exposures, do not generate a measurable increase in reproductive failures in the human population. When compared to other fields of human epidemiology, it is obvious that these studies have many difficulties. Exposures are rarely determined. Studies frequently involve small sample sizes and the investigators rarely have a combined expertise in EMF physics, engineering, and reproductive biology. Because of the allegation that there may be particular windows of frequency, wave shape, and intensity that may be deleterious, it is impossible to disregard low frequency EMF exposures as having no deleterious reproductive effects. Yet the epidemiologic data that are available would point in that direction. Secular trend data analysis of birth defect incidence data indicate that increasing generation of electric power during this century is not associated with a concomitant rise in the incidence of birth defects. There are over 70 EMF research projects dealing with animal and in vitro studies that are concerned with some aspect of reproduction and growth. Unfortunately, a large proportion of the embryology studies utilized the chick embryo and evaluated the presence or absence of teratogenesis after 48 to 52 hours of development.(ABSTRACT TRUNCATED AT 400 WORDS)

Multicenter, double-blind, placebo-controlled trial of terfenadine in seasonal allergic rhinitis and conjunctivitis.

A multiclinic, double-blind, parallel and controlled study was conducted in the 1982 spring pollen season to evaluate and compare the effects of terfenadine, 60 mg bid with those of chlorpheniramine 4 mg tid and placebo for a treatment period of seven days in patients with seasonal allergic rhinitis and conjunctivitis. Of a total of 397 patients enrolled in the seven study centers, 345 patients were accepted for evaluation of efficacy and 393 patients for safety. The results show that based on the physicians' assessment of the overall efficacy, terfenadine was significantly superior to placebo and comparable to chlorpheniramine in the relief of allergic symptoms, with moderate to complete relief being observed in 60% (68/113) of the terfenadine-treated patients, in 60% (71/119) of the chlorpheniramine-treated patients, and in 30% (34/119) of the placebo-treated patients. The daily evaluation of severity of symptoms by the patients show that the effect of terfenadine and chlorpheniramine was evident on the first day after entry, reached a peak on the second day after entry, and persisted thereafter. Side effects were minor and infrequent in all treatment groups. There was no statistically significant difference in the incidence of sedation between the terfenadine (7.6%) and placebo (2.4%) groups whereas the incidence of sedation with chlorpheniramine (19%) was significantly higher. In conclusion, terfenadine is as effective as chlorpheniramine in the treatment of symptoms of seasonal allergic rhinitis and conjunctivitis with an incidence of sedation not significantly different from that with placebo and significantly less than with chlorpheniramine.

Safety and efficacy of micronized estradiol vaginal cream.

Fifty-four postmenopausal patients with atrophic vaginitis satisfactorily completed one to two months' therapy with daily intravaginal application of 0.2 mg of 17 beta-estradiol in a cream base. No significant alterations were noted in the hematologic biochemical, and urine analyses. A number of response criteria showed significant improvement (P less than .01), including the severity rating for atrophic vaginitis, the maturation index of vaginal cells, the frequency and severity of hot flashes, the presence of vaginal dryness and itching, dyspareunia, skin flushing, and the severity of sweating episodes. The incidence of side effects was low and included breast tenderness and abdominal cramping.

Characterization of the intermediate (10 nm) filaments of cultured cells using an autoimmune rabbit antiserum.

An antiserum has been found in a nonimmunized rabbit which reacts strongly with a system of filaments in various fibroblasts, epithelial cells, macrophages and neuroblastoma. These filaments are distinct from the actin microfilament bundles visualized by an antibody against actin, and they are not affected by brief treatment with cytochalasin B. The pattern of these filaments somewhat resembles that described for microtubules, but the filaments could be clearly distinguished from microtubules by a comparison of their respective immunofluorescent patterns during cell division. In response to the drugs colcemid and vinblastine, the filaments reacting with this preimmune serum condense to form a compact perinuclear coil of fibers, a distribution and behavior in agreement with that previously described for the 10 nm or intermediate filaments studied by electron microscopy. Further evidence supporting our conclusion that this antiserum reacts with intermediate filaments is provided by a comparison of electron micrographs and the immunofluorescent patterns from parallel cell cultures. To identify the antigens reacting with this antiserum we have used the new technique of immuno-autoradiography on SDS gels of whole cell extracts. Two reactive polypeptide chains have been identified with apparent molecular weights of 56,000 and 30,000 daltons.