Metabolism of the benzodiazepine antagonist 11C-Ro 15-1788 after intravenous administration in man

The metabolic fate of the benzodiazepine antagonist RO 15-1788 labelled with ¹¹C was studied in plasma from human subjects after intravenous administration in connection with positron emission tomography. Ro 15–1788 and its metabolites were separated by thin-layer chromatography and the radioactivity in the different compounds was determined. ¹¹C-Ro 15–1788 was extensively and rapidly metabolised to the corresponding free acid. At 36 minutes after administration only 50% of the radioactivity in plasma represented unchanged compound.     

Bromine-76 and carbon-11 labelled NNC 13-8199, metabolically stable benzodiazepine receptor agonists as radioligands for positron emission tomography (PET)

NNC 13-8241 has recently been labelled with iodine-123 and developed as a metabolically stable benzodiazepine receptor ligand for single-photon emission computed tomography (SPECT) in monkeys and man. NNC 13-8199 is a bromo-analogue of NNC 13-8241. This partial agonist binds selectively and with subnanomolar affinity to the benzodiazepine receptors. We prepared ⁷⁶Br labelled NNC 13-8199 from the trimethyltin precursor by the chloramine-T method. Carbon-11 labelled NNC 13-8199 was synthesised by N-alkylation of the nitrogen of the amide group with [¹¹C]methyl iodide. Positron emission tomography (PET) examination with the two radioligands in monkeys demonstrated a high uptake of radioactivity in the occipital, temporal and frontal cortex. In the study with [⁷⁶Br]NNC 13-8199, the monkey brain uptake continued to increase until the time of displacement with flumazenil at 215 min after injection. For both radioligands the radioactivity in the cortical brain regions was markedly reduced after displacement with flumazenil. More than 98% of the radioactivity in monkey plasma represented unchanged radioligand 40 min after injection. The low degree of metabolism indicates that NNC 13-8199 is metabolically much more stable than hitherto developed PET radioligands for imaging of benzodiazepine receptors in the primate brain. [⁷⁶Br]NNC 13-8199 has potential as a radioligand in human PET studies using models where a slow metabolism is an advantage. Received 19 April and in revised form 10 June 1997     

In vitro evaluation of ablation parameters of normal and fibrous aorta using smooth excimer laser coronary angioplasty

A modified exeimer laser energy delivery system was used to irradiate 100 segments of normal and fibrous aorta in vitro. The laser beam was scanned into 8 fiber bundles consisting of 50 fibers each resulting in a reduction of the applied pulse energy. The total repetition rate was increased to 150 Hz in order to keep the repetition rate per fiber bundle close to 20 Hz and to minimize thermal injury. The results demonstrate that effective ablation (etch rate per 8 pulses > 2.0 μm) occurred at an energy fluency of 50 mJ/mm² in both normal and fibrous aorta. Tissue damage (carbonization, tissue separation, fissures, cracks, and vacuolization) was in a range of 100 ± 28 to 152 ± 30 μm for normal aorta and in a range of 57 ± 35 to 110 ± 39 μm for fibrous aorta. We conclude that effective ablation of normal and fibrous human aorta can be achieved by the application of smooth excimer laser coronary angioplasty. This improvement of excimer laser technology may result in a reduction of shock wave- and cavitation-induced damage leading to a reduction of tissue injury. However, this awaits further in vitro and in vivo confirmation. © 1993 Wiley-Liss, Inc.     

Human imaging of phosphorus in cortical and trabecular bone in vivo.

Phosphorus was imaged in vivo in human cortical and trabecular bone and the T(1) and T(2) (*) were measured. An ultrashort TE (UTE) pulse sequence (TE = 70 microm) was used with half pulse excitation and radial mapping of k-space from the center out. T(2) (*) was measured using multiple echo times and T(1) was measured both by saturation recovery and by a method using different RF pulse amplitudes. Seven normal subjects (32-85 years) were examined. Phosphorus was imaged, with a true in-plane resolution of 2.9 x 2.9 mm and a signal-to-noise ratio (SNR) of 19:1, in both cortical and trabecular bone. The mean T(2) (*) value was 207 +/- 12 micros, and the mean T(1) value was 8.6 +/- 3.0 sec. Images and measurements were obtained in realistic times on a clinical MR system. This may provide a new approach to characterizing disease of bone.     

Das kleinzellige Bronchialkarzinom – neue Entwicklungen nach ASCO 2007

Wiener Medizinische Wochenschrift - Aggressives Tumorwachstum, frühe Metastasierung und hohe Assoziation mit intensivem Nikotinkonsum sind die Charakteristika des kleinzelligen...     

Laparoskopisch-pelvine Lymphadenektomie nach definitiver Strahlentherapie des Prostatakarzinoms

Ohne Zusammenfassung     

Polycystic kidney disease genes and polycystins

Conclusion The past decade has seen extraordinary progress in the study of autosomal-dominant polycystic kidney disease. The 2 major genes for this disorder have been identified. Animal models of ADPKD have been produced. The molecular basis of the disease has been characterized. ADPKD is a “second-hit” disease, much like many cancer predisposition syndromes. This has profound implications for our understanding. The progression of ADPKD in individual patients is likely related more to their individual rate of acquisition of second hits at thePKD1 orPKD2 locus than to the inherited germ line mutation itself. Therapeutic approaches will perhaps now be considered, which will include interventions that may limit the rate at which somatic mutations occur in the kidney. The major focus of research at present is to elucidate the normal functions ofPKD1 andPKD2. Protein binding partners are being sought for both proteins. The possible calcium channel function ofPKD2 is being investigated. The downstream effects of cellular deficiency of either protein are likely to yield many clues. Modifying genetic factors that may independently affect disease progression are likely to be identified using the several mouse models. Perhaps the next decade will bring great strides in understanding and in potential therapy for this common disease. This paper was presented at the 2nd International Forum “The Frontiers of Nephrology,” Tokyo, May 10, 1998.