Ovulationshemmer bei Risikogruppen

Severe adverse effects during the use of ovulation inhibitors occur mostly in women who have an elevated risk for the development of certain diseases owing to hereditary or acquired factors. By means of a careful personal or family history analysis as well as specific laboratory examinations, an existing predisposition may frequently be diagnosed and the individual risk associated with the use of oral contraceptive inhibitors may be estimated. The present contribution describes the potential effects of treatment with ovulation inhibitors on women with thrombophilia, cardiovascular disease, diabetes mellitus, dyslipidemia, overweight or underweight, tumors, psychiatric and neurological diseases and autoimmune disease. The hormonal methods and non-hormonal alternatives available for contraception are elucidated according to existing lesions and risk factors and the advantages and disadvantages are discussed.     

A Chinese adolescent girl with Fechtner-like syndrome

We describe a 15-y-old girl with Fechtner-like syndrome, who is the first Chinese reported to have this rare syndrome. She presented with left homonymous hemianopia and neuroimaging revealed haemorrhage in both parietal and occipital lobes. Peripheral blood smear showed macrothrombocytopenia and intracytoplasmic inclusion bodies inside leucocytes. Thrombocytopenia and proteinuria responded to intravenous immunoglobulin and pulsed methylprednisolone. This case illustrates that life-threatening haemorrhage can occur in patients with Fechtner syndrome. Although there was no effective treatment reported in the literature, high dose steroid and immunoglobulin seemed to be useful in our patient. Our patient also had nephritic-nephrotic syndrome with renal insufficiency, which is unusual in adolescent female patients.     

Differentiation of radioligand delivery and binding in the brain: validation of a two-compartment model for [11C]flumazenil

We recently developed a two-compartment, two-parameter tracer kinetic model to estimate the in vivo ligand transport rate (K1) and distribution volume (DV) for the benzodiazepine antagonist [11C]flumazenil (FMZ) as measured by positron emission tomography (PET). The aim of the present study was to validate that this simplified model provides a stable measure of regional benzodiazepine receptor availability even when ligand delivery is altered. Six young normal volunteers underwent two PET studies subsequent to intravenous injections of [11C]FMZ. Each FMZ study was immediately preceded by measurements of CBF following injection of [15O]water. One set of scans (water/FMZ) was acquired under resting conditions and the other set during audiovisual stimulation. Six additional volunteers underwent two FMZ studies under identical resting conditions. Parametric images were analyzed and a comparison of test-retest studies in the stimulation group revealed a significant increase of CBF and K1 of FMZ in the occipital cortex evoked by visual activation, whereas no regional changes were noted for the DV of FMZ. No significant changes were noted for either K1 or DV of FMZ when comparing studies in the rest-rest setting. The results indicate that the use of a simple two-compartment model for the tracer kinetic analysis of [11C]FMZ makes it possible to separate high-affinity binding from altered radio-ligand delivery to the human brain.     

In vivo muscarinic cholinergic receptor imaging in human brain with [11C]scopolamine and positron emission tomography.

Cerebral muscarinic cholinergic receptors were imaged and regionally quantified in vivo in humans with the use of [11C]scopolamine and positron emission tomography. Previous studies in experimental animals have suggested the utility of radiolabeled scopolamine for in vivo measurements, on the bases of its maintained pharmacologic specificity following systemic administration and the exclusion of labeled metabolites from the brain. The present studies describe the cerebral distribution kinetics of [11C]scopolamine in normal subjects following intravenous injection. Scopolamine is initially delivered to brain in a perfusion-directed pattern. After 30 to 60 min, activity is lost preferentially from cerebral structures with low muscarinic receptor density including the cerebellum and thalamus. Activity continues to accumulate throughout a 2 h postinjection period in receptor-rich areas including cerebral cortex and the basal ganglia. The late regional concentration of [11C]scopolamine does not, however, accurately parallel known differences in muscarinic receptor numbers in these receptor-rich areas. Tracer kinetic analysis of the data, performed on the basis of a three-compartment model, provides receptor binding estimates in good agreement with prior in vitro measurements. Kinetic analysis confirms significant contributions of ligand delivery and extraction to the late distribution of [11C]scopolamine, reconciling the discrepancy between receptor levels and tracer concentration. Finally, a novel dual-isotope method for rapid chromatographic processing of arterial blood samples in radiotracer studies is presented. The combination of rapid chromatography and compartmental analysis of tracer distribution should have broad utility in future in vivo studies with short-lived radioligands.