Real-time handheld emission spot allocator (rthESA) for simultaneous fusion imaging with ultrasound.

OBJECTIVES: First, to report on initial experiences and technical parameters of a newly developed real-time handheld emission spot allocator (rthESA), and second, to report on the simultaneous acquisition of rthESA and US data as rthESA/US fusion images. METHODS: The rthESA consisted of five semiconductor-detectors arranged in alternate position in two rows. This design allowed the examination of focal activities in the same plane as US. The signals were interpreted by an ad hoc software and the real-time allocation of spot radiation sources within air- and water phantoms was investigated for (99m)Tc, 131I, and 18F. A compact US probe was fixed in plane with the rthESA and connected to a standard US equipment. Experiments with a liver phantom were performed to verify the integration of (99m)Tc-rthESA data and US images. RESULTS: The allocation proved to be successful for all radionuclides. The system showed a noticeable performance latency, most pronounced for positions far from the detector (1 cm distance: 0.7 ± 0.5 s; 4 cm distance: 6.1 ± 3.2 s). Within the liver phantom, the rthESA enabled the correct allocation of a spot radiation source within a live US image. CONCLUSIONS: The rthESA allowed an exact localization of spot radiation sources in single plane, with additional consideration of the distance from the detector, leading to real-time allocation and simultaneous overlay with US images. In spite of clear technical limitations in need of further development, this proof-of-concept study shows that this hybrid detector has the potential to provide integrated simultaneous nuclear medicine and US images.

Long-term effects of restrictive culture conditions on Saccharomyces cerevisiae sec7 cells.

Long-term effects of restrictive conditions on the temperature-sensitive S. cerevisiae sec7 mutant were studied. By microscopic analysis no cell lysis could be detected of cells cultured for up to 19 days at 37 degrees C. The optical density as well as the cell number remained constant during the whole period under restrictive conditions. However, restrictive conditions decreased the incorporation of 35S-methionine into intracellular proteins in a reversible manner indicating that protein biosynthesis was inhibited whereas the cells remained alive. Northern blot experiments revealed that restrictive conditions did not markedly decrease the ratio of the mRNA levels to total RNA for the genes TEF1, TEF2, SUC2, and BGL2 up to 73 hours. However the content of total RNA decreased drastically with increasing incubation times at restrictive temperature. In spite of the reduced total RNA content, cells are capable of new synthesis of mRNA under restrictive conditions which was shown by incubation of the cells in the presence of actinomycin D--an inhibitor of the mRNA synthesis. Most of the cells which survived a long-term incubation at 37 degrees C are not able to divide and to form colonies immediately after their transfer to permissive conditions.

[The problems of spotted breeds of rabbits. 4. Morpho- and histometric findings in the CNS and thyroid glands and the hormone content in blood at slaughter of hybrid rabbits, and estimation of the heterosis effect]. / Zur Problematik der Scheckenzucht bei Kaninchen. 4. Mitteilung: Morpho- und histometrische Befunde am ZNS und der Schilddrüse sowie SH-Gehalte im Schlachtblut von Hybridkaninchen, Beurteilung des Heterosiseffektes.

Morpho- und histometric investigations of brains, pituitary and thyroid glands as well as thyroid-related functional parameters in the blood of purebred and hybrid rabbits revealed a predisposition to hypothyreotic conditions in homozygous, megacolon-prone genotypes. In addition to this also a hypoganglionotic state in different gut wall localizations was confirmed; pituitary traits however did not indicate a primary contribution of this gland to the syndrome, though some alterations were found, which are interpreted as secondary sv. symptomatic. Gender influences varied hormonal characteristics and disease manifestations too: A dramatic fall in severely diseased does with respect to T3-concentration as well as a seemingly more inactive thyroid gland compared to bucks underline hormonal influences. As a consequence of these results it is concluded, that hybridisation within spotted rabbits does not amend the inclination to megacolon in animals homozygous for the K (En) gene, though it may influence its manifestation.