Substitution with testosterone as aromatizable substrate for induction of follicular maturation, estradiol production and ovulation in a patient with 17 alpha-hydroxylase deficiency.

17 alpha-Hydroxylase Deficiency (17 alpha-OHDS) is a rare defect of steroid biosynthesis, characterized by the inability to synthesize cortisol, androgens or estrogens, by the complete absence of follicular maturation, hypergonadotropic hypogonadism, primary amenorrhea and hypertension. Since the ovaries of such patients contain numerous primordial follicles, we hypothesized that the absence of spontaneous follicular maturation could be due to a lack of aromatizable substrate. To provide this substrate, testosterone was administered either by intra-ovarian injection or by vaginal administration. Ovarian stimulation was performed with human urinary gonadotropins. Follicular maturation and ovulation could be induced by this treatment, as determined from ultrasonography, the analysis of LH, estradiol and progesterone serum levels and the aspiration of oocytes from the mature follicles. Fertilization of these oocytes in vitro, however, did not succeed. We conclude that follicular maturation can be induced in 17 alpha-OHDS by gonadotropins when testosterone is provided as an aromatizable substrate and that estrogens are a necessary component of follicular maturation.

[The ultrasonic diagnosis of foreign bodies in the horse]. / Ein Beitrag zur sonographischen Diagnostik von Fremdkörpern beim Pferd.

Ultrasonography in veterinary practice represents a method that nowadays is a approved component of the examination of small and large animals. Although sometimes more difficult than in small animals, ultrasonography can be often useful in horses. In the present report two cases demonstrate the possibility of sonography in the diagnostic of foreign bodies in soft tissues in horses.

[Estimation of the occupational radiation exposure during radiographic studies of horses]. / Zur Abschätzung der beruflichen Strahlenbelastung bei Röntgenuntersuchungen vom Pferd.

Radiography of horses in veterinary practice is done normally with quite simple equipment. Thereby radiation protection is easily neglected. In this investigation sources of mistakes are demonstrated. The possible exposure of staff is evaluated by dose measuring over a long period of time. It can be stated that following the most simple radiation protection there will never be a significant exposure of staff.

Estimation of releases into rivers with the steady-state surface water model EXWAT using dichloromethane.

The surface water model EXWAT is applied to monitoring studies of hazardous substances to estimate site-specific emissions from measured concentrations. The model includes the main processes which govern the fate of chemicals in rivers, namely, advection, volatility, degradation processes, sedimentation, resuspension, and protonic equilibria. The steady-state solution of the linear mass balance equations leads to proportionality between input and concentration of a chemical, which is used to assess input rates from measured concentrations. Subsequently, the model can be used for pollution control and identification of unknown releases. With measured concentrations in the Rhine near Koblenz (95 km downstream from the mouth of the river Main) the load of dichloromethane from the tributary Main was estimated. The comparison with measured concentrations in the tributary mouth has a good agreement in this case.

[Possibilities for reducing radiation exposure during radiography of small animals]. / Möglichkeiten der Reduzierung der Strahlenbelastung bei der Röntgenuntersuchung von Kleintieren.

Veterinarians may suffer from chronic radiation injuries if exposed consistently to small doses of x-rays over a long period of years. Such injuries can positively be avoided by using accurate techniques. This paper makes suggestions how veterinary radiologists can reduce the radiation exposure by following very simple precautions.