bluuebunny/crossref_metadata_2025_split huggingface dataset:
Subcellular Site of Biosynthesis of the Catecholamine Biosynthetic Enzymes in Bovine Adrenal Medulla
Authors: Sabban Esther L. , Goldstein Menek 
Published: October 2006

AbstractThe subcellular site of biosynthesis of the catecholamine biosynthetic enzymes was examined. Free and membrane‐bound polysomes were prepared from bovine adrenal medulla and mRNA was isolated from these polysomes. Both were active in directing cell‐free translations. Immunoprecipitation of cell‐free products with specific antisera localized the biosynthesis of the subunits of tyrosine hydroxylase (TH) (apparent Mr= 61,000) and of phenylethanolamine N‐methyltransferase (PNMT) (apparent Mr= 32,000) on free polysomes, compared with biosynthesis of subunits of dopamine β‐hydroxylase (DBH) (apparent Mr= 67,000) on membrane‐bound polysomes. Cross‐reactivity between translation products was observed. Antibodies for DBH recognized a poly‐peptide with electrophoretic mobility identical to newly synthesized PNMT. However increasing concentrations of antibodies to DBH recognized at most 1/2 of the PNMT formed. The results of this study show the subcellular distribution of the catecholamine synthesizing enzymes is determined by their site of biosynthesis.
High‐Affinity Uptake of Neurotransmitters in Rat Neostriatum: Effects of Aging
Authors: Strong Randy , Samorajski T. , Gottesfeld Zehava 
Published: October 2006

AbstractHigh‐affinity uptake of dopamine (DA), glutamate, and γ‐aminobutyric acid (GABA) was determined in crude synaptosomal preparations from neostriatal regions of rats 7, 17, and 27 months of age. Dopamine uptake was highest in rostral neostriatum, but no age‐related differences were detected. On the other hand, the high‐affinity uptake of both GABA and glutamate was increased with age. This may reflect astrocytic hypertrophy or hyperplasia, which have been reported to occur in the neostriatum during the aging process.
Effect of Cortico‐Striate Pathway Lesion on the Activities of Enzymes Involved in Synthesis and Metabolism of Amino Acid Neurotransmitters in the Striatum
Authors: Sandberg M. , Ward H. K. , Bradford H. F. 
Published: October 2006

Abstract:The activities of several enzymes involved in the metabolism of aspartate and glutamate were measured in striatal (nucleus caudatus and putamen) homogenates 2–3, 6–7, and 35–40 days following frontoparietal and frontal cortical ablation. The activity of glutamine synthetase (GS) was substantially increased (46–48%) on the operated side 6–7 days following the lesion whereas smaller changes were observed at 2–3 and 35–40 days after lesion. In contrast, decreased levels of glutaminase and malate dehydrogenase (MDH) were observed by 6–7 days while no significant change was found at either 2–3 or 35–40 days after the lesion. The activities of glutamate dehydrogenase (GDH) and glutamate decarboxylase (GAD) were elevated after 35–40 days whereas no changes in the levels of either GDH or aspartate aminotransferase (ASAT) were found at 2–3 or 6–7 days after the fronto‐parietal decortication. When only the frontal cortex was removed quantitatively similar changes were observed in striatal GS and glutaminase activity. The content of glutamate and glutamine in the denervated striatum followed qualitatively the changes in glutaminase and GS. The results indicate that the degeneration of cortico‐striatal terminals causes a profound glial reaction in the striatum, and both glutaminase and MDH are present in relatively high concentrations in the corticostriatal terminals.
Modulation by Monoamines of Somatostatin‐Sensitive Adenylate Cyclase on Neuronal and Glial Cells from the Mouse Brain in Primary Cultures
Authors: Chneiweiss H. , Glowinski J. , Prémont J. 
Published: October 2006

Abstract:Primary cultures of mouse embryonic neuronal or glial cells from the cerebral cortex, striatum, and mesencephalon were used to identify and determine the cellular localization of somatostatin receptors coupled to an adenylate cyclase. Somatostatin inhibited basal adenylate cyclase activity on neuronal but not on glial crude membranes in the three structures examined. The somatostatin‐inhibitory effect on neuronal crude membranes was still observed in the presence of (—)‐isoproterenol, 3,4‐dihydroxyphenylethylamine (dopamine, DA), or 5‐hydroxytryptamine (5‐HT, serotonin) used at a concentration (10−5M) inducing maximal adenylate cyclase activation. In addition, in most cases biogenic amines modified the pattern of the somatostatin‐inhibitory effect, triggering either an increase in the peptide apparent affinity for its receptors or an increase in the maximal reduction of adenylate cyclase activity or both. However, 5‐HT did not modify the somatostatin‐inhibitory response on striatal and cortical neuronal crude membranes. The changes in somatostatin‐inhibitory responses were interpreted as a colocalization of the amine and the peptide receptors on subtypes of neuronal cell populations. Finally, somatostatin was shown to inhibit adenylate cyclase activity following its activation by (—)‐isoproterenol on glial crude membranes of the striatum and the mesencephalon but not on those of the cerebral cortex.
Glutamine Synthetase of the Human Brain: Purification and Characterization
Authors: Yamamoto Hirotaka , Konno Hidehiko , Yamamoto Teiji , Ito Kitae , Mizugaki Michinao , Iwasaki Yuzo 
Published: October 2006

AbstractGlutamine synthetase (GS) isolated from human brain formed a single band on sodium dodecyl sulfate‐poly‐acrylamide gel with a molecular weight of 44,000. The enzyme had a specific activity of 179.2 U/mg protein when assayed by measuring the rate of the formation of γ‐glutamylhydroxamate using hydroxylamine as a substrate. In the presence of manganese ions, the relative activity of human brain GS was much lower than that of the sheep brain enzyme. The suppression of activity by increasing the ADP concentration, however, was less marked in the human enzyme than that in the sheep enzyme. Antibodies were raised in rabbits against the purified enzyme. The double‐immunodiffusion technique disclosed cross‐reactivities among GSs isolated from human, sheep, and rat brains, but the enzymes were not immunologically identical. Immunohistochemically, GS was localized in the cytoplasm of astrocytes in the human and rat brains and in pericentral hepatocytes of the liver.
Solubilization of Kainic Acid Binding Sites from Rat Brain
Authors: Hampson D. R. , Huie D. , Wenthold R. J. 
Published: October 2006

Abstract:Kainic acid binding sites were solubilized from rat brain using a combination of Triton X‐100 and digitonin. The highest percentage of solubilized binding sites (45%) was obtained by treating brain membranes with 1 % Triton‐X‐100 and 0.2% digitonin in 0.5 M potassium phosphate containing 20% glycerol. The solubilized binding sites were stable and amenable to analysis by gel nitration and lectin affinity chromatography. Computer assisted analyses demonstrated that the solubilized sites displayed high‐and low‐affinity binding constants similar to the membrane‐bound sites. Competition experiments further supported the pharmacological similarities of the solubilized and membrane‐bound sites. Gel nitration chromatography of the solubilized binding site indicated that the detergent‐bound complex had a Stokes radius of 82.7 A. The [3H]kainic acid binding site appears to be glycosylated based on its capability to bind to lectins. The lectin, wheat‐germ agglutinin, proved to be a potentially useful tool for characterization because the solubilized binding sites were bound and eluted in relatively high yield.
Gangliosides and Other Lipids of the Growth Cone Membrane
Authors: Sbaschnig‐Agler Michele , Pfenninger Karl H. , Ledeen Robert W. 
Published: October 2006

AbstractGrowth cone membranes, derived from growth cone particles isolated from 16‐ to 18‐day‐old fetal rat brain, were found to be rich in overall lipid content with a lipid‐to‐protein ratio of 3.5. The phospholipid‐to‐cholesterol ratio indicated considerably less cholesterol than plasma membranes from mature neurons. All major classes of phospholipid were present in the usual proportions except sphingomyelin, which could not be detected. Gangliosides expressed in relation to protein were present at somewhat higher levels compared to previously reported values for synaptic plasma membranes (73 versus 44 μg/mg protein), but when related to phospholipid their level was well below that of the latter (26 versus 62 μg/mg phospholipid). The ganglioside pattern was generally similar to that of mature synaptic membranes except for the presence of relatively more GD3 and less GD1a, a phenomenon also observed in whole fetal brain of the same age. Several neutral glycosphingolipids were detected, glucosylceramide being the major one of this group. Their total level in growth cone membranes was roughly comparable to that of gangliosides, but unlike the latter their concentration in whole brain decreased with development. For comparison we analyzed the ganglioside composition of mixed membrane fractions from the same fetal brains and found no significant differences between these and growth cone membranes, suggesting that these glycoconjugates are not localized specifically in the growth cones. Neutral glycosphingolipids, on the other hand, appeared somewhat more concentrated in growth cones than in the mixed membranes.
Uptake of Glycine into Synaptic Vesicles Isolated from Rat Spinal Cord
Authors: Christensen Hege , Fykse Else M. , Fonnum Frode 
Published: October 2006

Abstract:Glycine was taken up by a synaptic vesicle fraction from spinal cord in a Mg‐ATP‐dependent manner. The accumulation of glycine was inhibited by carbonyl cyanide‐m‐chlorophenylhydrazone (CCCP) and nigericin, agents known to destroy the proton gradient across the vesicle membrane. Vesicular uptake of glycine was clearly different from synaptosomal uptake, with respect to both the affinity constant and the effect of Na+, ATP, CCCP, and temperature. Oligomycin and strychnine did not inhibit the vesicular uptake, showing that neither mitochondrial H+‐ATPase nor binding to strychnine‐sensitive glycine receptors was involved. It is suggested that the vesicular uptake of glycine is driven by a proton gradient generated by a Mg2+‐ATPase. A low concentration of Cl‐ had little effect on the uptake of glycine, whereas the uptake of glutamate in the same experiment was highly stimulated. High concentrations of γ‐amino‐n‐butyric acid and β‐alanine inhibited vesicular glycine uptake, but glutamate did not. Accumulation of glycine was found to be fourfold higher in a spinal cord synaptic vesicle fraction than in a vesicle fraction from cerebral cortex.
Telang Liver and Vitamin A Toxicity
Authors: Herbst Edward J. , Pavcek Paul L. , Elvehjem C. A. 
Published: October 2006

(1) About 20 per cent. of fresh telang livers were toxic to weanling rats receiving the calcium supplemented livers as their sole dietary.
(2) The symptoms observed in rats were growth failure and multiple spontaneous fractures of the bones of the extremities.
(3) The toxicity of certain telang livers was due to their abnormally high stores of vitamin A. When these livers, supplemented only with calcium carbonate, were fed to weanling rats, the daily intake of vitamin A was in excess of the toxic dosage of 15,000 I.U. per day.
(4) Identical symptoms of toxicity were observed in weanling rats fed 20,000 I.U. of crystalline vitamin A per day in conjunction with a standard stock ration.
Sedimentation of Poliomyelitis Virus by Centrifugation
Authors: Silverberg Rosalie J. 
Published: October 2006

A technic is described whereby poliomyelitis virus may be sedimented by centrifugation for four hours at 18,000 r.p.m.
Virus has been recovered quantitatively in the sediment from a 20 per cent., but not a 1 per cent., saline suspension. The addition of 10 per cent. normal serum results in quantitative recovery from a 1 per cent. suspension.
Virus has been recovered by intracerebral inoculation from two of four human stools tested by the method described.
Effect of Penicillin on Seed Germination
Authors: Smith Walton J. 
Published: October 2006

The substances present in therapeutic penicillin which cause inhibition of germination and root growth are represented by the indole-3-acetic acid type of compound. Since this and phenylacetic acid were known to be present in the penicillin tested, it is concluded that they are responsible for the inhibition activity against seeds.
None of the crystalline penicillins tested appreciably retarded germination.
Recent Advances in Color Vision
Authors: Hartridge H. 
Published: October 2006

Until a few years ago it was possible to account for nearly all the aspects of human color perception on the basis of the three-color theory, but such is no longer the case. This is largely due to improvements in the older methods of investigation and to the invention of new ones. Among the latter may be mentioned the microelectrode technique of Granit and the retinal direction effect of Stiles and Crawford. Modern requirements are met by a polychromatic theory, comprising 7 types of receptor, but there is no necessity for these to have such narrow spectral response curves as those exhibited by Granit's modulators. Modifications of the three- and four-color theories have been examined to see to what extent they can be made to fit in with experimental results. Particular notice has been taken of the possibility that there is polychromatism of the retinal receptors, but trichromatism of the nerve paths which connect these to the brain or even of the brain itself.
The conclusion arrived at is that there must be polychromatism throughout the entire visual mechanism for color perception if a complete account is to be given of all the known facts.
Haploidploidy and the Evolution of the Social Insect
Authors: Trivers Robert L. , Hare Hope 
Published: October 2006

Hamilton was apparently the first to appreciate that the synthesis of Mendelian genetics with Darwin's theory of natural selection had profound implications for social theory. In particular, insofar as almost all social behavior is either selfish or altruistic (or has such effects), genetical reasoning suggests that an individual's social behavior should be adjusted to his or her degree of relatedness, r, to all individuals affected by the behavior. We call this theory kinship theory.
The social insects provide a critical test of Hamilton's kinship theory. When such theory is combined with the sex ratio theory of Fisher, a body of consistent predictions emerges regarding the haplodiploid Hymenoptera. The evolution of female workers helping their mother reproduce is more likely in the Hymenoptera than in diploid groups, provided that such workers lay some of the male-producing eggs or bias the ratio of investment toward reproductive females. Once eusocial colonies appear, certain biases by sex in these colonies are expected to evolve. In general, but especially in eusocial ants, the ratio of investment should be biased in favor of females, and in ants it is expected to equilibrate at 1 : 3 (male to female). We present evidence from 20 species that the ratio of investment in monogynous ants is, indeed, about 1 : 3, and we subject this discovery to a series of tests. As expected, the slave-making ants produce a ratio of investment of 1 : 1, polygynous ants produce many more males than expected on the basis of relative dry weight alone, solitary bees and wasps produce a ratio of investment near 1 : 1 (and no greater than 1 : 2), and the social bumblebees produce ratios of investment between 1 : 1 and 1 : 3. In addition, sex ratios in monogynous ants and in trapnested wasps are, as predicted by Fisher, inversely related to the relative cost in these species of producing a male instead of a female. Taken together, these data provide quantitative evidence in support of kinship theory, sex ratio theory, the assumption that the offspring is capable of acting counter to its parents' best interests, and the supposition that haplodiploidy has played a unique role in the evolution of the social insects.
Finally, we outline a theory for the evolution of worker-queen conflict, a theory which explains the queen's advantage in competition over male-producing workers and the workers' advantage regarding the ratio of investment. The theory uses the asymmetries of haplodiploidy to explain how the evolved outcome of parent-offspring conflict in the social Hymenoptera is expected to be a function of certain social and life history parameters.
Bone Marrow Transplantation
Authors: Congdon C. C 
Published: October 2006

The goals in bone marrow transplantation are its application to the treatment of diseases arising in the blood-forming tissues of man. Techniques for procuring and grafting marrow are of the needle-and-syringe type and are based on the normal physiological processes in which stem cells circulate through blood and other fluids of the mammalian organism. Destruction of bone marrow by irradiation, chemicals, or unknown agencies provides the immediate experimental system for demonstrating the therapeutic value of marrow transplants. Genetic diseases characterized by abnormal marrow function are also modifiable by grafts of blood-forming tissues. Studies with identical twins are critical experiments for showing the clinical value of grafts, even though the transplanted cells cannot be identified by the usual marker techniques. Among the best results seen with marrow grafting is the presumed cure of certain rare hereditary immune-deficiency disorders of children.
A major problem in bone marrow transplantation—one that delays its wider clinical application—is the immune reaction from cells growing out of the foreign transplant which attack the host (the graft-versus-host reaction). Attempts to use a graft-versus-host response to eliminate tumor cells is a part of the marrow research program.
The history of the processes that led to some of the achieved goals in marrow grafting shows the usual multicentric origin of an idea. Certain individuals play critical roles in developing the idea. Finally, a body of knowledge is accumulated that opens up or limits prospects for the future.
In bone marrow transplantation, future achievements will depend in part on the progress that is made in the areas of cell separation, bone marrow banking, and tissue culture.
Reaction of Reindeer to Obstructions and Disturbances
Authors: Klein David R. 
Published: October 2006

In Scandinavia, highways and railroads have not generally created obstructions to the movement of domesticated reindeer, although thousands of animals are killed each year in accidents. Some disruption in the movements of wild reindeer in Norway has been associated with the construction of a railroad and highway through an alpine plateau south of Trondheim.
Hydroelectric projects have had the greatest detrimental effects on reindeer by flooding rangelands and obstructing migration routes. Special problems are created by the fluctuating water levels in reservoirs and rivers; efforts to mitigate the effects of these fluctuations have been only partially successful. Reindeer have strong traditions for migrating along specific routes, and realignment of these routes is extremely difficult.
Conflicts of interest exist between reindeer herders and foresters. During their winter feeding, the deer damage young trees. The cutting of forests usually results in a deterioration of the area as a rangeland for reindeer. Herbicides used in forestry have been implicated in the death of some reindeer in Sweden, and research is now under way to determine the effects of herbicides on reindeer.
The increased use of fences in reindeer husbandry in Scandinavia has emphasized the fact that reindeer behavior and characteristics of the terrain must be considered if fences are to be successful in directing or controlling the movements of reindeer. Herders now use snowmobiles instead of reindeer for transportation and herding, but the machines disturb the reindeer and must be used with discretion.
Recent evidence indicates that large amounts of industrial waste in the atmosphere are carried from the British Isles and central Europe to Scandinavia, where they fall out in rain and snow. This has raised concern about the influence of the wastes on lichens, the main winter food supply of reindeer. Studies are now under way in Finland, Sweden, and Norway, through the International Biological Program, to determine the growth rates of the several lichen species that are important to reindeer.
Power, Fresh Water, and Food from Cold, Deep Sea Water
Authors: Othmer Donald F. , Roels Oswald A. 
Published: October 2006

Many times more solar heat energy accumulates in the vast volume of warm tropic seas than that produced by all of our power plants. The looming energy crisis causes a renewal of interest in utilizing this stored solar heat to give, in addition to electric power, vast quantities of fresh water. Warm surface water, when evaporated, generates steam, to power a turbine, then fresh water when the steam is condensed by the cold water.
A great increase in revenues over that from power and fresh water is shown by a substantial mariculture pilot plant. Deep sea water contains large quantities of nutrients. These feed algae which feed shellfish, ultimately shrimps and lobsters, in shallow ponds. Wastes grow seaweed of value; and combined revenues from desalination, power generation, and mariculture will give substantial profit.
Disposal of Nuclear Wastes
Authors: Kubo Arthur S. , Rose David J. 
Published: October 2006

For the present and the foreseeable future the following options appear to be either usable or worth further exploration: mausolea; disposal in mines of various sorts, and perhaps in ice; in situ melt; and further chemical separations. The options are interdependent.
It is too early to assess disposal in space, and disposal in the oceans remains unsafe for lack of adequate knowledge. Table 3 is a summary of the main ideas for which we have worked out (sometimes uncertain) costs.
For the short term, ultimate disposal in deep mines is the best-developed plan. However, the related concept of in situ melt has significant advantages and should be realistically appraised. Further chemical separation with subsequent recycling of the actinides in a LMFBR should be investigated and implemented, for it would be universally beneficial; on the other hand, additional removal of strontium and cesium does not seem attractive. Thus, for the near future we make the following recommendations:
1) Provide temporary storage facilities to ensure that the projected commercial high-level wastes do not become a public hazard. The AEC adopts this view, and has stated an intention to construct such facilities. But because of the capriciousness of man and nature, a workable ultimate disposal scheme must be developed soon.
2) Fund other ultimate disposal schemes at the same rate as the salt mine project—say $1 million a year or more—to sharpen the technological issues, so that a decision can be reached in the next few years. The schemes should include (i) in situ melt, and the variation with a central repository; (ii) burial in mines other than salt mines (including Antarctic rocks and permanent ice); (iii) further chemical separation of actinides and recycling actinides in a LMFBR.
3) Maintain liaison with the developing space shuttle technology to insure that no opportunity is lost.
The AEC has a commitment to hold safety foremost in its waste management program, but budget considerations and management priorities have downgraded the program. Past funding levels and management emphasis have yet to produce, after a decade and a half, one operational long-term storage facility—a sign of both commendable caution and inadequate work. If nuclear power is to resolve our energy needs in the coming decades, its benefits should not be delayed for lack of a viable management program for high-level wastes.