Bacterial utilization of cyclo(glycyl-L-prolyl)

Summary 3 strains of soil bacteria (2Achromobacter, 1Flavobacterium) were isolated by growth on cyclo(Gly-L-Pro) as carbon/nitrogen source. Good growth required yeast extract supplements. Utilization of cyclo(Gly-L-Pro) was inducible. Many efforts failed to obtain active cell-free preparations. Injected radioactive cyclo(Gly-L-Pro) was excreted intact by the albino rat; in contrast, injected radioactive H-Gly-L-Pro-OH was extensively metabolized.Supported by Grant GM-11105 from the National Institutes of Health.     

Naturally occurring heterocycles inducing drought resistance in plants

Summary During screening of animal metabolites which induce drought resistance in plants, two diketopiperazines, cyclo(L-Hyp-L-Pro) (1) and cyclo(L-Hyp-L-Leu) (2), emerged as effective. When rice seeds were pretreated with the cyclic dipeptides (1 and2) during their germination period, the resulting seedlings showed significant resistance to water-stress caused by 0.5–1.5% NaCl solution or 2.5–5.0% mannitol solution.     

Heterologe Transplantation von Tumoren nach Vorbehandlung der Wirtstiere mit radioaktiven Isotopen

Summary The investigation deals with the successful heterologous transplantation of the Mouse Crocker-Sarcoma on young rats, that were pretreated with the radioactive isotopes P³² and Au¹⁹⁸. The growth tendency of the tumours varies according to the character of the radioactive isotope, the mode of administration and the interval between the injection of the radioactive substance and the heterotransplantation.     

Methylmercury sexual dimorphism in the mouse

Summary 5–8 days after a single nontoxic dose of radioactive methylmercury chloride adult male mouse kidneys contain twice as much radioactive mercury per unit wet wt as do kidneys of similarly dosed adult females.This investigation was supported in part by NSF (RANN) grants (GI-30097 and AEN75-14889), by Program Project grant (ES-01248) and Center grant (ES-01247) from the NIEHS, and in part by the US Department of Energy at the University of Rochester Department of Radiation Biology and Biophysics and has been assigned Report No. UR-3490-1308.     

The importance of radioactivity in geoscience and mining

Almost simultaneously with Roentgen rays, natural radioactivity was discovered. Its investigation led to important fundamentals of the geosciences: petrophysics, terrestrial heat flow, isotope geology, and absolute geological chronology. In applied geophysics and geology, exploration of radioactive ores and of tectonic faults, and radiometric well loggings, are used. Production of radioactive water and mining for uranium ores are discussed, including their development (especially in the Saxon ore mountains) and the consequences on health (radon in underground air and houses). Disposal of radioactive waste is touched on briefly.     

Analyse de l'induction neurale par autoradiographie

Summary Neural induction is accompanied by a migration of granules from the organizer to the reacting ectoblast (Brachet). The radioautographs of embryos or explants of amphibians seem to show that such a migration to the induced organs takes place when a marked organizer is grafted in a non-radioactive host.Substances of high molecular weight (proteins or nucleic acids) diffuse from an organizer tagged either with radioactive glycine or with radioactive orotic acid.     

Über die Wirkung von 7,12-Dimethylbenz(a)-anthrazen auf die Synthese der Lactatdehydrogenase-Isoenzyme in menschlichen Fibroblasten

Summary The effect of 7,12-Dimethylbenz(a)anthracene (DMBA) on the activity of lactate dehydrogenase (LDH)-isoenzymes was studied in human fibroblast cultures. 3 isoenzyme components were separated by discelectrophoresis. A clear reduction in the enzymeactivity of the first and third component was observed, while the other fraction was little or not affected. The incorporation of radioactive amino acids in proteins of the LDH-isoenzyme bands shows the same trend.     

Kaurene biosynthesis in intactPhaseolus coccineus suspensors

Summary Intact suspensors fromPhaseolus coccineus seeds incorporate 2-(¹⁴C)-MVA into a number of radioactive compounds, among which kaurene was identified by GC-MS. This result confirms that the kaurene biosynthetic pathway previously shown for cell-free extracts is active in intact tissues as well.     

Binding of 3,3',5'-triiodo-L-thyronine (rT3) to human serum proteins]

The rT3-binding and human serum proteins was directly studied with tracer doses of radioactive rT3. Polyacrylamide gel electrophoresis showed 125I-rT3 added to human serum was distributed among two proteins: albumin (carrying 57% of tracer rT3) and TBPA )22%). No binding was observed to TBG, protein binding T4.     

Zur Biosynthese von Biopterin in Säugetieren

Summary Biosynthesis of biopterin in mice and rats was studied. After vascular injection of¹⁴C-GTP (U) in mice and rats, radioactive biopterin was isolated from the urine. The specific radioactivity of 6-carboxypterin obtained by oxidation of biopterin was proved to be 7/9 that of biopterin. The result definitely shows that biopterin is biosynthesized from GTP in mice and rats, and the sidechain of biopterin is derived directly from the ribose moiety of GTP.     

Distribution of the blood flow supplied by the vertebral artery in rats: anatomical, functional and pharmacological aspects.

In rats, the vertebral artery make only a minor contribution to the blood perfusion of the ponto-medullary area. This was measured with radioactive microspheres and was confirmed by methylmetacrylate casts and local injection of a centrally acting hypotensive drug.     

Microbial influence on the sorption of137Cs onto materials relevant to the geological disposal of radioactive waste

Summary A major concern in the geological containment of radioactive wastes is the speed of movement of radionuclides from the repository, after their eventual leaching and release, into the geosphere and finally into the biosphere. Radionuclide sorption onto the host rock is an important retarding mechanism. Experimental evidence shows that the presence of microbes in this environment influences the sorption capabilities of the host rock. Their presence can decrease the amount of retardation of¹³⁷Cs, a common radionuclide in radioactive waste, by the solid phase. Sorption methods and data analysis procedures are presented and the implications for radioactive waste disposal assessments are discussed.     

Distribution of the blood flow supplied by the vertebral artery in rats: Anatomical,functional and pharmacological aspects

In rats, the vertebral artery makes only a minor contribution to the blood perfusion of the ponto-medullary area. This was measured with radioactive microspheres and was confirmed by methylmetacrylate casts and local injection of a centrally acting hypotensive drug.     

Characterization of the "4 S-trypsin" form of the cytosoluble estradiol receptor of calf uterus in a nondenaturing system]

The characterisation of the "4 S-trypsin" form of the estradiol-receptor from calf uterus cytosol was carried out by polyacrylamide gel electrophoresis under non-denaturing conditions. In a multiphasic buffer system (upper buffer Tris-glycine pH25degrees C = 8,6, lower buffer Tris HCl pH25degrees C = 7,4), three radioactive estradiol peaks were observed. The first was free estradiol, the second estradiol initially complexed with a macromolecule and dissociated during electrophoresis, and the third the hormone-receptor complex. The sedimentation coefficient (4 S) of this complex was the same before and after electrophoresis. Its mean geometric radius is R = 2.53 + 0.08 nm and its molecular weight was estimated to be 55,000.     

Einfluss der Wurzeln auf die Trigonellinsynthese beiCoffea arabica

Summary Young plants ofCoffea arabica were fed 200 µC C¹⁴O₂ each, the carbon dioxide being absorbed by photosynthesis. The specific activity of the alkaloid trigonelline contained in the leaves was shown to be strongly dependent of leaf age. Excised plants without root system or plants with an interrupted shoot-root connection as regards pholem transport (by girdling the stem below the cotyledons) incorporate more radioactive carbon into the molecule of trigonelline than intact plants.     

Amino acid incorporation by human milk fat globules membranes (author's transl)]

Human milk fat globule membranes (MFGM) can incorporate radioactive 14C amino acids in a hot trichloracetic acid-insoluble material. Aspecific adsorption and bacterial contamination are unlikely. The products of protein synthesis were analyzed by polyacrylamide gel electrophoresis in sodium dodecyl sulfate or by action of proteolytic enzymes. Various inhibitors of protein synthesis were assayed. Fragments of rough endoplasmic reticulum or mitochondria could be involved in this incorporation.     

Hemodynamic studies in acute venous stasis edema in rats

An increase in venous pressure in the rat tail is known to result in acute edema. Acute venous stasis edema of the rat tail was induced by applying a force-controlled banding of standard tension (200 g) proximally for a period of 6-12 h. The hemodynamic changes of acute venous stasis edema were evaluated using non-invasive plethysmography, fluorescence angiography, computer thermography and invasive radioactive microsphere techniques. It is shown here that reduction of tail circulation to 40% of the control value is followed by prolonged vascular disorder characterized by genesis of reversible edema, increased total blood flow to the tail and decreased local cutaneous blood flow, without affecting the general hemodynamics. The cutaneous circulation (decreased blood flow) seems to be principally involved in the edemogenic response, whereas the deeper vessels (hyperemia) may or may not play a determinant role in acute experimental venous stasis edema in rats.     

A rapid electrophoretic method for the separation of hydroxyproline from proline

Summary A rapid, sensitive procedure is described which uses custom made apparatus to separate radioactive imino acids. This technique provides a simple measurement of the distribution of newly synthesized collagen in different fractions.Acknowledgment. This work was supported by grants from the International Wool Secretariat.     

Über die Verwendung von künstlichen radioaktiven Isotopen zur Erzielung von lokalisierten biologischen Strahlenwirkungen

Summary The author made a first attempt to utilize an artificial radioactive isotope for the production of localized biological radiation-effects, by means of intraperitoneal injections of radiozinc (Zn⁶³) suspended in a solution of pectine. Experiments were performed on mice and rabbits and the procedure was applied, for the purpose of preliminary therapeutic investigations, to a case of carcinoma of the ovary with severe peritoneal extension.     

Modification de métabolisme des ARN induites par l'adrénaline dans les cellules animales

Summary The effects of adrenalin were studied on mice liver RNA, with different concentrations and action times. It was found that, after the incorporation of the radioactive precursor, the activity increased rapidly, followed almost immediately by an inhibition, which itself decreased progressively.