[Comparative investigations of osteotropic radionucleides. IV. The dynamics of uptake in normal and abnormal bone (author's transl)]. / Vergleichende Untersuchungen mit osteotropen Radionukliden; IV. Dynamik der Anreicherung im normalen und pathologisch veränderten Knochen

The dynamics of uptake of osteotropic radionucleides in normal and abnormal bone were studied by means of sequential and functional scans. Various phosphate and phosphonate complexes were compared in vivo and in vitro. Only phosphonates were considered as suitable for bone scanning. In normal bones in beagles, radioactivity after HEDP fell to 65% after two hours, but was 105% with 18F. In relation to healing fractures, the curves differ quantitatively and qualitatively. In this situation, functional curves derived from dynamic scans provide a better parallel with histological findings than does static scintigraphy with an uptake quotient. Sequential and functional scanning are able to document the therapeutic effect of irradiation of bone metastases.

[Comparative investigations of osteotropic isotopes. i animal experiments on the uptake of 18f, 85sr and 99mtc-ehdp (author's transl)]. / Vergleichende Untersuchungen mit osteotropen Radiopharmaka. I. Tierexperimentelle Untersuchungen zur Anreicherung von 18F, 85Sr und 99mTc-EHDP

In normal rabbit bones, as well as in callus, there is significantly more uptake of 18F than of 85Sr or 99mTc-EHDP. Extraosseous abscesses show significantly higher uptake of 99mTc than of 18F or 85Sr. In the presence of hyeraemia, there is no significant difference in the uptake of the various osteotropic radio-nucleides.

[Creation of reaction-less pseudoarthrosis on the ulna of the dog (author's transl)]. / Zur experimentellen Erzeugung reakionsloser Pseudarthrosen an der Ulna des Hundes.

The model situation of so called "avital, avascular" pseudoarthrosis was surgiclly induced in 25 beagle dogs using defectosteotomy and heat-necrotization of both ulna bones. The clinical evolution was examined weekly using roentgengraphy and each 4th week by scintigraphy. According to roentgen pictures three stages can be identified: 1. Reaction of the bone on surgical trauma (until 4th week). 2. Sequestration or asepticosteolysis (until 18th week). 3. Consolidation of the pseudoarthrosis model-situation (after 18th week). Scintigraphy revealed by the continuing so called "avital" pseudoarthrosis an enhanced metabolism activity at the tips of both bone fragments. The cause for these active metabolic processes evoking enhanced activity on both fragment ends during scintigraphy wich is not demonstrable with roentgen device are the pulling, pushing and tensile strengths originating from a connective-tissue-cord existing between them. The results of scintigraphy lead us to use the term "reaction-less pseudoarthrosis" instead of "avascular" or "avital" for this model of pseudoarthrosis.

Renal vein renin measurements in normotensive children.

Renal venous PRA was measured in 49 normotensive children without renal disease undergoing routine cardiac catheterization. PRA levels did not differ significantly between both renal veins and were significantly higher in the renal veins than in the IVC. There was a constant mean ratio of 1.21 between the renal veins and the IVC at low, intermediate, and high absolute PRA levels. Three patients had a renal venous PRA ratio greater than 1.4 and the highest ratio observed was 1.55. This fidning supports 1.5 as an acceptable upper limit of normality for the interpretation of renal vein PRA ratios in the investigation of patients with suspected renal hypertension. In four patients, PRA in the renal veins was significantly lower than in the IVC. The possibility of renin removal by these kidneys is discussed.