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Biomedical subjects

M Falk

Publications and source records attributed to M Falk.

At least 109 records · Page 6Linked to original sources

Amniotic fluid testosterone and follicle-stimulating hormone assay in the prenatal determination of fetal sex.

Amniotic fluid testosterone was assayed by radioimmunoassay in 812 samples taken at 16 weeks' gestation at the time of genetic amniocentesis. In each of 361 samples (45% of total), correct assignment of fetal sex was made where the testosterone level was above 33.8 ng/ml for male fetuses and below 16.2 ng/ml for female fetuses. In each of 159 of 353 (45%) samples assayed for follicle-stimulating hormone (FSH), levels were below 7.6 mlU/ml for male fetuses and above 10.9 mlU/ml for female fetuses. By combining the two assays in the testosterone/FSH ratio, correct assignment of sex was made in each of 282 samples (80%). The percentage of samples in which correct assignment was achieved was greater for female fetuses (ratio less than 2.2 in 161/187 [86%]) than for male fetuses (ratio greater than 3.4 in 121/166 [72%]). The testosterone/FSH ratio holds promise as a rapid biochemical screening tool in the prenatal diagnosis of fetal sex in X-linked disorders.

Amniocentesis↗

Results of a double-blind controlled study on the use of betamethasone in the prevention of respiratory distress syndrome.

A double-blind controlled study on the prenatal use of betamethasone in the prevention of respiratory distress syndrome (RDS) was carried out on 137 patients from 24 to 34 weeks' gestation. The incidence of RDS was less in the treated group (5%) than in control group (17%). The neonatal mortality rate was lower in the treated group (5%) than in the control group (18%) due to an excess of neonatal deaths in the placebo group.

Betamethasone↗

Prenatal diagnosis of fetal sex by amniotic fluid testosterone and FSH, and their potential use in detecting sex linked disorders.

Amniotic fluid testosterone was assayed by radioimmunoassay in 971 samples at 16-18 weeks gestation. FSH assay was performed in 353 of these samples. Correct prediction of fetal sex (46%) was made in all samples with a testosterone level above 338 ng/L for all males, and below 162 ng/L for females. For 45% of samples with FSH levels below 7.6 IU/L for males and 10.9 IU/L for females the fetal sex was predicted correctly. By using a testosterone/FSH ratio, the diagnostic accuracy was 80%. The anmiotic fluid of ten Duchenne Muscular Dystrophy carrier mothers were studied and only the sex of one case could not be predicted. The amniotic fluid testosterone and FSH assays could be used as a rapid biochemical screening method for predicting fetal sex in X-linked disorders before birth.

Amniotic Fluid↗

Changes in mammary development and composition of secretion during late pregnancy in the mare.

Small samples of mammary secretion were taken for analysis from Thoroughbred mares during the last 3 weeks of pregnancy up to the time of foaling. The concentrations of sodium and chloride decreased while those of lactose, potassium, citrate, phosphate, calcium, magnesium and protein increased. The time-course of these changes showed marked variation between animals. The concentration of whey proteins began to increase about 10 days before parturition. The appearance of the secretion and the size of the mammary glands increased in the last few days of pregnancy. It is suggested that the concentration of calcium in mammary secretion could provide the basis of a test for impending parturition in this species.

Animals↗

[Aspects of the application of models in pharmaceutical research (author's transl)].

Starting from historical examples of the application of models in scientific research, the author treats the present significance of this working method in pharmacy. A short description of various types of models and of the definition of the term "model" is followed by an outline of the major aspects to be considered in using models. The different steps of model elaboration, the requirements to be considered with model elaboration as well as questions concerning the analogy, main properties, goals and limitations of models, and the validity of the results obtained are briefly dealt with and illustrated by examples.

Models, Theoretical↗