SEARCH · Search PubMed
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The studies were carried out with pigs and rats. The radioactive animo acids (14C leucine and 3H lysine) were administered to the pigs by way of a catheter tube into the jugular vein. Subsequently, the time pattern of the distribution of the specific amino acid radioactivity was followed in the TCE soluble and Tce precipitable fractions of the blood plasma (TCE= trichloro-acetic acid). The radioactive labelling in rats was carried out by injecting 14C leucine into the portal vein. The animals were killed after incorporation periods from 2 to 60 mins, and the levels of specific radioactivity were estimated in the TCE soluble and TCE precipitable fractions of the blood plasma, in the liver and in the skeletal muscles. The experimental results clearly indicated that the specific radioactivity of the tracer amino acids and the rate of incorporation of radioactivity into tissue proteins were greatly influenced by the size of the free amino acid pool within the range of distribution of the tracer. An estimation of the magnitude of the pool of free amino acids within the distribution range of the tracer can be obtained from the curve pattern for the decline of specific radioactivity of the corresponding free amino acid in the blood plasma. This pool exhibits a high rate of turnover. In all studies made to evaluate in vivo processes of protein synthesis by use of radioactive tracer amino acids it will be particularly important that consideration should be given to the specific radioactivity of the amino acid in the precursor pool for protein synthesis.
Male Albino rats (weighing 90-100 gms) were fed ad libitum for 14 days with limited periods of access to food. Powdered whole egg (V), fish meal (F), yeats (H), and gelatine (10% protein in dry matter) used as protein sources. Additionally, one group of rats received a protein-free (e). Radioactive tracers were administered by intragastric infusion of 25 mu Ci 3H glycine and 5 mu Ci 14C L-leucine per 100 gm of body weight 2 hrs after the feeding of 2 gm of the experimental diet per 100 gms of body weight. The level of uptake of radioactive tracers from the different sections of the gastro-intestinal tract was measurels of 3H and 14C labelling in intestinal tissues were observed 3 hrs and 7 hrs after infusion. The level of 14C labelling was found to be negatively correlated and the level of 3H labelling was positively correlated with the biological value of the diet. Intestinal tissues are capable of storing considerable amounts of 14C radioactivity. So, 72 hrs after infusion, the following levels of 14C radioactivity (expressed as percentage of the total dose of radioactivity) were found in tissues of the gastro-intestinal tract: whole egg: 8.4%, fish meal: 9.6%, yeast: 13.1%, gelatine: 14.9%; protein-free diet; 14.2%. The quotients correlating the levels of radioactivity from the intestinal contents with that found in the intestinal wall suggest that the walls of the small intestine possess a high capacity for absorption. At all times of radioactive measurements the walls of the small intestine were found to contain higher levels of both 14C and 3H radioactivity than the contents of small intestine.
1. Crude synaptosomal fractions (P2) from guinea-pig cerebral cortex were incubated in a Krebs-glucose medium containing labelled fatty acids and [3H]glucose. After the shortest incubation period (7.5 min) a high percentage (50-80%) of the total radioactive fatty acids was found in the P2 fractions. 2. After the incubation, the synaptosomal fractions were submitted to hypo-osmotic disruption and subsynaptosomal fractionation was carried out by using discontinuous-sucrose-gradient centrifugation. The specific radioactivities of phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine and phosphatidylinositol were determined in fractions D (synaptic vesicles), E (microsomal preparation) and H (disrupted synaptosomes), as were the specific activities of a number of marker enzymes and the distribution of acetylcholine. 3. By using [14C]oleate, [14C]arachidonate, [3H]palmitate and [3H]glucose, the order to specific radioactivities in fraction D was found to be: phosphatidylinositol greater than phosphatidylcholine greater than phosphatidylserine greater than phosphatidylethanolamine. 4. The specific radioactivities of phosphatidylcholine and phosphatidylethanolamine were always higher in fraction D than in fraction E. As fraction E had higher specific activities of several membrane marker enzymes, the enhanced labelling found in fraction D was considered to be localized in the synaptic vesicles. In this fraction, phosphatidylinositol made particularly large contributions to the total phospholipid labelling derived from [14C]arachidonate and [3H]glucose. 5. The similar labelling ratios of fatty acid/glucose in the phospholipids of fractions D and E, and the high specific radioactivities in the total phospholipid of the soluble fraction O, suggested intrasynaptosomal phospholipid transport.
Growing male rats received diets of varying biological value (protein sources: powdered whole egg (V); fish meal (F); yeast (H); gelatine (G); protein-free diet (e)) for a 14-day feeding period. Subsequently, 14C leucine and 3H glycine were administered intragastrically. The level of uptake of 14C and 3H radioactivity into blood plasma, liver and muscular tissue and the rate of incorporation of the radioactive tracers into the proteins of these tissues was examined. A negative correlation was found to exist between the incorporation of radioactivity into liver proteins and the biological value of dietary proteins, the former being mainly dependent on the level of incorporation into the liver. For muscular proteins the rate of incorporation decreases with the decreasing biological value of the dietary proteins. This may be attributed to the fact that with poor protein nutrition the rate of protein synthesis in the skeletal muscles is also reduced. Comparative studies on the specific 14C radioactivity from free leucine made in the group on the protein-free diet and in the group receiving the whole egg diet showed that the leucine pool of the skeletal muscles was markedly redueced in animals fed a protein-deficient diet while the leucine pool in the liver remained comparatively constant.
Improvements in the sensitivity of non-radioactive in situ hybridization histochemistry methods for detection of mRNA now make it feasible to combine the use of non-radioactive and radioactive in situ methods to visualize two mRNAs on the same tissue section. The method reported here allows the simultaneous detection of two mRNAs in one cell and therefore is ideally suited to the studies of co-expression. Here we demonstrate the co-expression of tyrosine hydroxylase (TH) mRNA and cholecystokinin (CCK) mRNA in the ventral mesencephalic dopaminergic neurones of the rat. The distribution of dopaminergic neurones containing both TH and CCK transcripts suggests, on the basis of earlier anatomical studies that these CCK/TH-containing doubled-labelled cells project mainly to the striatal matrix. Dopamine neurones believed to project to the patch compartment did not contain CCK mRNA.
A total of 234 urogenital specimens were investigated with a radioactive and a nonradioactive rRNA:cDNA-hybridization test for the direct detection of Chlamydia trachomatis (Gen-Probe, San Diego, Calif.). The results were compared with those yielded by the conventional cell culture technique (McCoy cells). Using cell culture a urogenital C. trachomatis infection could be detected in 37 of 234 patients (15.8%) at two outpatient sexually transmitted disease clinics. Referred to the detection rate, cell culture sensitivity was 83.8% for the radioactive test and 86.5% for the nonradioactive DNA-hybridization test. The specificity of the radioactive test was 94.8% and that of the nonradioactive test, 93.4%.
In order to establish the drainage of radioactive waste water 1976 in the Federal Republic of Germany a new law for radiation protection was introduced. In this paper a concept is introduced how to determine specifications for constructing a decay plant using the given data of a department for nuclear medicine. The given boundary conditions were to secure a low concentration of radioactive material in order to establish the drainage of extreme low activities without diluting it.
This review summarizes measurements made of 152Eu and 60Co radioactivity induced by neutron radiation from the Hiroshima atomic bomb (A-bomb) with the goal of estimating the neutron dose released by the bomb. Prior to these measurements, A-bomb-irradiated specimens such as rocks and pieces of concrete, which had not been shielded were collected. The specific radioactivity obtained (in bequerels per gram of Eu or Co) were compared with those calculated from DS86 neutrons. Findings of usefulness of 152Eu data within 700 m ground range are reported and systematic differences between measured activities and calculations are discussed. The 152Eu data were also useful for the discussion of circular asymmetry, and there was no asymmetry within the experimental errors. This review also covers the similar difference found in 32P data, which were measured immediately after the A-bomb, along with the other 152Eu and 60Co data. The need for more measurements of 152Eu activity in samples farther away from the hypocenter in order to verify the DS86 calculations is also discussed.
In the present study some experimental parameters for in situ hybridization histochemistry (ISHH) have been analysed using 35S-labelled and alkaline phosphatase-conjugated probes, in order to develop a reproducible double-labelling procedure. We have compared the total exclusion of tissue fixation with tissue sections fixed by immersion in formalin. In addition, the effect of dithiothreitol was assessed both when combining radiolabelled and non-radioactive probes on a single tissue section and when the probes were used separately. Hybridization of unfixed tissue resulted in stronger specific labelling and lower background both for radiolabelled and alkaline phosphatase-conjugated probes. No loss in tissue preservation was seen at the light microscopic level after hybridization of unfixed tissue. High concentrations (200 mM) of dithiothreitol strongly suppressed background when using 35S-labelled probes, whereas in the non-radioactive procedure, alkaline phosphatase labelling could only be achieved with very low dithiothreitol concentrations (less than 1 mM). This incompatibility led to a protocol using unfixed tissue sections and a sequential hybridization procedure, with the radiolabelled probe and high concentrations of dithiothreitol in the first step and the alkaline phosphatase-conjugated probe without dithiothreitol in the second step.
Three studies of fallout measurements were reviewed for the discussion of possible radioactivity intake from the Hiroshima atomic bomb. The first study discussed correlations between enriched 234U and 137Cs specific activities from the measurement of soil samples collected in the "black rain" area. The second study measured 137Cs activity on the rock and roof tile samples collected in the hypocenter area immediately after the explosion. Some of the rock and roof tile samples collected near the hypocenter had a small but detectable amount of 137Cs activity. However, it has been determined that 137Cs exposure, for example, was negligible compared with DS86 dose estimates, since these activity levels were low. The third study detected 90Sr activity in some of the specimens of human bones exhumed on Ninoshima Island. This study compared the difference in activity between the bone head and shaft, with higher activities obtained in the bone head. This fact suggests a short intake period for this activity, however, the levels of 90Sr contamination were too low to allow a discussion of the exposure risks.
The residual Eu-142 radioactivity due to the atomic bomb explosion in 1945 was first found in 1976 by in-situ high resolution gamma-ray spectrometry at Hiroshima. Since then, various studies on this nuclide have continued not only in Hiroshima but also in Nagasaki and they have contributed to the reevaluation of the neutron dose due to the A-bombing. By radiochemical separation methods and alpha-ray spectrometry, rather high levels of plutonium were found in the surface soil and in the bottom sediment of water reservoir which were collected at "Black rain area" in Nagasaki. The U-234/U-238 activity ratios for the uranium leached with 0.1 HNO3 from the surface of soil samples were found to be relatively higher for the samples which were collected at "Black rain area" in Hiroshima.
After suicide of the anti-dinitrophenyl (DNP) clone E21 in a previous experiment (Eur. J. Immunol. 1975. 5:58) several new clones (S clones) appeared promptly in the recipients. There was compelling evidence that they were then resistant to suicide, relative to E21. We now report further studies on these S clones and their antibodies. The antibodies of half of the S clones had affinities ten to one hundred times higher than E21 (3 x 10(-7) M); none was lower. The four tested were also able to bind DNP on the particular conjugate used for the suicide procedure. Three of the S clones were serially propagated, they showed a very great capacity for proliferation, transferring into 510, 85 and 110 recipients each. When their cells were tested at subsequent passages, they recovered early after inhibition by radioactive antigen. Two S clones may still have been somewhat refractory to suicide but, probably in all three, rapid proliferation was largely responsible for the recovery of the few cells escaping suicide, and helped them to appear suicide resistant.
We present here a method enabling the simultaneous detection of two messenger RNAs in tissue sections by use of a two-step in situ hybridization procedure. Tissue sections were hybridized with a radioactive probe and coated with emulsion. The emulsion was processed for development, fixed, and a second hybridization was performed through the emulsion with a biotinylated probe subsequently revealed with streptavidin-alkaline phosphatase. This procedure allows the detection of two mRNAs without loss of signal, removal of the emulsion, or spurious reaction. The simultaneous detection of oxytocin and vasopressin mRNAs in the hypothalamus, and of dopamine receptor and neuropeptide mRNAs in the striatum, demonstrated the efficiency of the procedure. Such a two-step procedure provides a simple and flexible way to make possible comparative analysis of the localization of two mRNAs within the same tissue section.
Dynamical changes in the spleen of mice and rats were studied morphometrically and electron microscopically when the animals were given in drinking water radionucleotides in small concentrations (137Cs, 226Ra, 89Sr, 65Zn, Pb(NO3)2, BeCl2, hexamethyleniamine, methylmercurchloride) for 1-2 years. Total doses obtained for a year were 0.3-100 rad. Reactive reconstruction of the organ under radioactive and chemical effects was stated to proceed in three directions: a) hyperplasy of lymphoid tissue; b) enhanced plasmocytogenesis; c) hyperplasy of extramedullar hemopoiesis. Sequence in the appearance of these reactions and doses which produced them were different for every compound. In 1-2 years at large doses (160-200 rad) atrophy, amyloid degeneration of the spleen or signs of leukemia were observed. Disturbance of intercellular contacts and of intracellular regeneration was demonstrated electron microscopically.
Explore the source record for details and available documents.
Explore the source record for details and available documents.