Factors influencing the distribution of 99m-technetium methylene diphosphonate in bone and soft tissues

Summary The influences of dilution, storage and pH on the distribution of 99m-technetium methylene diphosphonate (99m-Tc-MDP) in bone and various soft tissues have been investigated in the rat. The results show a marked departure from normality when large dilution factors and very acidic or basic preparations are used.     

Monitoring of the dilution rate during continuous in vivo blood sampling with a double lumen catheter.

A simple and non-destructive method for monitoring the dilution rate during continuous blood sampling is described. When the dilution rate is not constant, the proposed method based on electrical resistivity measurement provides a correction factor for further analysis.     

Monitoring of the dilution rate during continuous in vivo blood sampling with a double lumen catheter

Summary A simple and non-destructive method for monitoring the dilution rate during continuous blood sampling is described. When the dilution rate is not constant, the proposed method based on electrical resistivity measurement provides a correction factor for further analysis.     

Über das Problem der Welkekrankheiten bei Pflanzen

Summary Lycomarasmin is a plasma poison produced byFusarium lycopersici Sacc., the pathogen of tomato wilt. In a dilution of 10^–2 and 10^–3 mol it causes a pathological wilting of tomato plants and usually disturbs their water balance; in a dilution of 10^–4 mol it only disturbs the latter.In the present paper, we develop the theory that in sufficient concentration lycomariasmin damages or destroys thesemipermeability of the plasma boundary layer.In a dilution of 10^–2 and 10^–3 mol of lycomarasmin the semipermeability of the plasma membranes iscompletely destroyed. Thus on the one hand the conditions for osmotic pressure disappear and irreversible pathological wilting appears, and on the other hand cellular fluid passes into the transpiration current of the cell-membrane and leads to a momentary excess humidity, particularly in the leaf-tissues, and thus also to a momentaryexcess transpiration.The water-deficit regularly observed in wilt-literature is therefore not the cause of pathological wilting but, just as the wilting itself, a consequence of the distruction of the semipermeability of the plasma boundary layer.In a dilution of 10^–4 mol lycomarasmin apparently only affects the permeability of the exterior plasma boundary layer forwater, but not for sugars etc. Therefore it only produces an excess of fluid in the leaf tissues and thus an excess transpiration, but no definite inactivation of the plasma membrane and therefore also no pathological wilt.     

99mTc-MDP extraction in relation to 81mKr perfusion following a partial osteotomy in the dog tibia

The bone mineral extraction of technetium-99m-methylene diphosphonate (99mTc-MDP), and blood supply of Krypton-81m (81mKr) have been compared in normal and osteotomy regions of the canine tibia. A partial osteotomy was carried out under aseptic conditions, and isotopic measurements made over a period of 123 days. Both blood flow and bone mineral extraction increase after a partial osteotomy.     

Comparison of the production rates of bacteria in the rumen estimated by using labelled live and formaldehyde treated mixed bacterial cells

The bacteria production rates in the rumen have been estimated by injecting 14C- and 35S-labelled mixed rumen bacteria, either live or killed by treatment with formaldehyde, into the rumen and applying isotope dilution technique. The rate of bacteria production when estimated by using either live- or dead-(protected-)labelled bacterial cells were comparable.     

Action d'une irradiation générale sur les échanges d'eau entre le sang et la cavité gastrique pendant l'absorption du glucose

Summary A sublethal dose of X-rays, delivered to guinea-pigs 14 days before a glucose absorption test, alters the pattern of water exchange between the blood and the gastric cavity. The normal dilution, which proves to be a main factor in the regulation of the intestinal absorption of sugar, is no longer achieved.     

Further evidence for the existence of a bottleneck in the metabolism of Saccharomyces cerevisiae

The growth physiology of Saccharomyces cerevisiae strains H1022 and Whi2+ has been studied in aerobic batch and continuous (chemostat) cultures. Results from the measurement of biomass and medium components (off-line) together with oxygen, carbon dioxide and heat measurements (on-line) have been used in an attempt to explore the existence of 'overflow' or 'bottleneck' metabolism as opposed to catabolite repression (Crabtree effect) in these strains. Chemostat experiments indicated that specific oxygen uptake rate (qO2) was linearly related to the dilution rate (D) at values below the critical dilution rate (D crit), becoming constant above D crit, which is in agreement with the bottleneck theory. However, batch culture experiments indicated negligible oxygen consumption during the initial glucose growth phase, the culture exhibiting purely anaerobic metabolism. The bottleneck theory would propose that qO2 has a constant (maximum) value under these conditions. The results presented here suggest that while the bottleneck theory can be adequately used to describe chemostat growth of S. cerevisiae, some other control mechanism must be operating under conditions of high glucose concentrations, such as those initially prevailing in the batch culture experiments.     

99mTc-MDP extraction in relation to81mKr perfusion following a partial osteotomy in the dog tibia

Summary The bone mineral extraction of technetium-99m-methylene diphosphonate (^99mTc-MDP), and blood supply of Krypton-81m (^81mKr) have been compared in normal and osteotomy regions of the canine tibia. A partial osteotomy was carried out under aseptic conditions, and isotopic measurements made over a period of 123 days. Both blood flow and bone mineral extraction increase after a partial osteotomy.Acknowledgments. I wish to thank D. Zbrzeznj and C. Stoltenberg for their assistance.     

A fast osmotic transition method for the study of pulmonary transcapillary exchange: theoretical model]

A theoretical model allowed the simultaneous determination of the reflexion coefficients of capillary membrane to small hydrophilic molecules and of the ratios of their permeability to filtration coefficient. This was applied to dilution curves obtained after injection of a hypertonic solution containing a vascular tracer. The calculated variables did not depend on the capillary exchange surface area.     

Partial purification and some properties of a nucleoside phosphotransferase of chick embryos

Summary A nucleoside phosphotransferase purified about 40fold from chick embryos utilizes efficiently as phosphate donors deoxyribonucleoside and pyrimidine ribonucleoside monophosphates, whereas the pyrimidine deoxyribonucleoside appear to be the preferred acceptors of phosphate. The enzyme is very unstable to heat, dilution and dialysis. A marked enhancement in the stability is caused by nucleotides and it seems associated with the formation of an aggregated state of the protein.     

Comparison of the production rates of bacteria in the rumen estimated by using labelled live and formaldehyde treated mixed bacterial cells

Summary The bacteria production rates in the rumen have been estimated by injecting¹⁴C- and³⁵S-labelled mixed rumen bacteria, either live or killed by treatment with formaldehyde, into the rumen and applying isotope dilution technique. The rate of bacteria production when estimated by using either live- or dead-(protected-)labelled bacterial cells were comparable.     

Immunocytochemical location of the centrosphere of human cancer cells using natural rabbit antibodies]

Sera of 40 normal nonimmunized rabbits were eprouved by immunoperoxidase on cultural human cells. Four sera contain centrosphere-reactive antibodies and for the strongest serum the centrospheres were still stained with the 1/600 dilution. This last serum visualized the centrospheres within the height human cell lines eprouved, whatever the phase of the mitotic cycle. The staining was not inhibited after serum absorption by tubulin.     

Antagonism of V2-receptor effect of antidiuretic hormone by atrial natriuretic peptide in man

Human alpha-atrial natriuretic peptide (h-alpha ANP) makes the urine of dehydrated volunteers hypotonic to plasma despite high circulating concentrations of antidiuretic hormone. Urinary dilution with h-alpha ANP also occurs in subjects receiving indomethacin. Therefore, h-alpha ANP antagonises effects of antidiuretic hormone on distal tubular V2-receptors in man, probably without involving prostaglandins.     

Possibility of using131I-albumin as a marker for the estimations of microbial protein synthesis rates in the rumen

Summary Total microbial protein synthesis rates in the rumen of buffaloes were estimated by isotope dilution technique, using¹³¹I-albumin treated with tannic acid as a marker. The animals were fed groundnut cake treated with formaldehyde to meet 50% of their digestible crude protein (DCP) requirement and 2.5% urea molasses mixture was given to meet the remaining requirement of DCP. Wheat straw was fed as the basal roughage. The total average microbial protein synthesis was 58.14 g/day.     

The in vitro stability in human plasma of two different technetium-99m-fibrinogen compounds

Two 99mTc -labeling methods of human fibrinogen resulted in different complexes. This was concluded from different dissociation rates in human plasma. The dissociation could be described by a simple exponential function.     

Die Bildung von Fusarinsäure durchFusarium lycopersici in vivo

Summary With the aid of isotope dilution methods, it has been possible to show that the fungusFusarium lycopersici forms the wilt toxin,fusaric acid (or a closely related substance), not only in pure culture but also during its parasitic life in tomato plants.     

The in vitro stability in human plasma of two different technetium-99m-fibrinogen compounds

Summary Two^99mTc-labeling methods of human fibrinogen resulted in different complexes. This was concluded from different dissociation rates in human plasma. The dissociation could be described by a simple exponential function.     

Juvenile hormone active principle inAttacus atlas L

Summary The ether extract ofAttacus atlas L., subjected to an isotope dilution method for the determination of known insect juvenile hormones, revealed the presence of an active substance which has a similar chromatographic behaviour with the known JH-3, methyl (2E, 6E)-10, 11-epoxy-3, 7, 11-trimethyl-2, 6-dodecadienoate.The work was supported as a research training by Dr.R. Maag Ltd., CH-8157 Dielsdorf, Switzerland.