bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inhibition of Histamine Synthesis in Brain by α‐Fluoromethylhistidine, a New Irreversible Inhibitor: In Vitro and In Vivo Studies
Authors: Garbarg M. , Barbin G. , Rodergas E. , Schwartz J. C. 
Published: October 2006

Abstract:a‐Fluoromethylhistidine (α‐FMH), a new potent inhibitor of histidine decarboxylase (HD), has been used for in vitro and in vivo studies of brain HD. Following a preincubation with (+)‐α‐FMH, brain HD activity was inhibited in a time‐dependent and concentration‐dependent manner. The enzyme activity was not restored by overnight dialysis against standard buffer. The (–) antimer of α‐FMH was ineffective. When injected intraperitoneally in a single dose of 20 mg/kg, (±)‐α‐FMH induced a complete loss in HD activity in cerebral cortex and hypothalamus as well as in peripheral tissues, such as stomach. At a dosage of 100 mg/kg (±)‐α‐FMH did not alter histamine‐N‐methyltransferase, DOPA decarboxylase, and glutamate decarboxylase activities. The maximal decrease of HD activity occurred after 2 h in both cerebral cortex and hypothalamus, but the time course of the recovery of enzyme activity was slower in the cerebral cortex. The enzyme activity reached control value within 3 days in hypothalamus and was not fully restored after 4 days in cerebral cortex. Contrasting with the diminished HD activity, a substantial concentration of histamine remained present in five regions of mouse brain. Thus, α‐FMH is a highly specific irreversible inhibitor of brain HD activity and its efficacy makes it useful to study the physiological role of brain histamine.
Synaptic Proteins After Electroconvulsive Seizures in Immature Rats
Authors: Jørgensen Ole Steen , Dwyer Barney , Wasterlain Claude G. 
Published: October 2006

Abstract:The forebrain content of several rat brain synaptic proteins (synaptin, D1, D2, and D3) was reduced in rats receiving electroconvulsive seizures on days 2–11, 9–18, or 19–28 and sacrificed at the age of 30 days. Forebrain weight, total protein, and the glial enzyme glutamine synthetase were also decreased, whereas the neuronal enolase 14–3–2 was unchanged. The findings suggest that seizures in the immature rat brain resulted in a parallel reduction of synaptic material and of the amount of glial cells. The increased concentration of the enolase 14–3–2 found in rats seizured on days 19–28 may reflect the high demands on the glycolytic system during the seizures.
Discrimination of Multiple [3H]5‐Hydroxytryptamine Binding Sites by the Neuroleptic Spiperone in Rat Brain
Authors: Pedigo N. W. , Yamamura H. I. , Nelson D. L. 
Published: October 2006

Abstract:Certain neuroleptic drugs, such as spiperone and (+) butaclamol, can discriminate between two populations of [3H]5‐hydroxytryptamine ([3H]5‐HT) binding sites in rat brain. The butyrophenone neuroleptic spiperone shows the greatest selectivity for these two binding sites, having at least a 3000‐fold difference between its dissociation constants (2‐12 nM versus 35,000 nM) for the high‐ and low‐affinity sites, respectively. Inhibition of [3H]5‐HT binding by spiperone in rat frontal cortex and corpus striatum yields distinctly biphasic inhibition curves with Hill slopes significantly less than unity. Results from nonlinear regression analysis of these inhibition studies were consistent with a two‐site model in each brain region. In the frontal cortex the high‐affinity neuroleptic sites comprised about 60% of the total [3/H]5‐HT binding sites whereas in the corpus striatum they accounted for only 20% of the sites. Furthermore, saturation studies of [3H]5‐HT binding assayed in the absence or presence of 1 μM‐spiperone (a concentration that completely blocks the high‐affinity site while having minimal activity at the low‐affinity site) reveal a parallel shift in the Scatchard plot with no change in the dissociation constant of [3H]5‐HT, but a significant decrease (64% in frontal cortex or 28% in corpus striatum) in the number of specific binding sites. These observations are consistent with the existence of at least two populations of [3H]5‐HT binding sites having a differential regional distribution in rat brain.
Partial Inactivation of Na,K‐ATPase in Cortical Brain Slices Incubated in Normal Krebs‐Ringer Phosphate Medium at 1 and at 10 Atm Oxygen Pressures
Authors: Kovachich G. B. , Mishra O. P. 
Published: October 2006

Abstract:Na, K‐ATPase (ATP phosphohydrolase EC 3.6.1.3) activity was determined in homogenates of cortical brain slices after incubation in normal Krebs‐Ringer phosphate medium at 1 atm oxygen pressure. After 10 min of incubation Na,K‐ATPase activity was reduced by approximately 50%. Longer incubation did not cause further change in activity. The presence of 0.1 mM‐MnCl2 in the medium offered significant protection. while an excursion to 10 atm oxygen pressure caused further inactivation. Measurements of malonaldehyde levels suggest that the inhibition of Na,K‐ATPase is a result of lipid peroxidation. The evidence indicates that brain slices incubated under standard conditions suffer considerable oxidative damage.
Relative Levels of Hexokinase in Isolated Neuronal, Astrocytic, and Oligodendroglial Fractions from Rat Brain
Authors: Snyder Cynthia D. , Wilson John E. 
Published: October 2006

Abstract:The levels of hexokinase, as well as those of the cytoplasmic glycolytic enzyme lactate dehydrogenase and the mitochondrial tricarboxylic acid cycle enzymes fumarase and citrate synthase, have been determined in whole rat brain and in neuronal, astrocytic, and oligoden‐droglial fractions isolated from rat brain. Compared with either whole brain or with isolated neurons or astrocytes, oligodendroglia are low in hexokinase content. This provides direct confirmation for the conclusion, based on an electron microscopic immunohistochemical method, that oligodendroglia, compared with other neural structures, contain relatively low levels of this key enzyme of glucose metabolism. Based on this confirmation, it is concluded that the electron‐microscopic immunohistochemical procedure provides a valid indication of hexokinase content, and thus that other structures shown to stain weakly by the latter technique (e.g., dendritic terminals of cerebellar granule and Purkinje cells) are, indeed, low in hexokinase activity.
[3H]Nitrobenzylthioinosine Binding to the Guinea Pig CNS Nucleoside Transport System: A Pharmacological Characterization
Authors: Hammond James R. , Clanachan Alexander S. 
Published: October 2006

AbstractThe binding of [3H]nitrobenzylthioinosine (NBMPR) to specific membrane sites in guinea pig brain was rapid, reversible, and saturable, and was dependent upon protein concentration, pH, and temperature. Mass law analysis of the binding data for cortical membranes indicated that NBMPR bound with high affinity to a single class of sites at which the equilibrium dissociation constant (KD) for NBMPR was 0.10–0.25 nM and which possessed a maximum binding capacity (Bmax) per mg of protein of 300 fmol of NBMPR. Kinetic analysis of the site‐specific binding of NBMPR yielded an independent estimate of the KD of 0.16 nM. A relatively homogeneous subcellular distribution of the sites for NBMPR was found in cortical tissue. Recognized inhibitors of nucleoside transport were potent, competitive inhibitors of the binding of NBMPR in guinea pig CNS membranes whereas benzodiazepines and phenothiazines have low affinity for the sites. NBMPR sites in guinea pig cortical membranes have characteristics similar to those for NBMPR in human erythrocytes, the occupation of which is associated with inhibition of nucleoside transport. The comparable affinities for a range of agents for sites in human erythrocytes and guinea pig CNS membranes suggest that NBMPR also binds to transport inhibitory elements of the guinea pig CNS nucleoside transport system. It is proposed that the study of the binding of NBMPR provides an effective method by which to examine drug interactions with the membrane‐located nucleoside transport system in CNS membranes.
Effect of Glutamine on Glutamate Release from Hippocampal Slices Induced by High K+ or by Electrical Stimulation: Interaction with Different Ca2+ Concentrations
Authors: Szerb John C. , O'Regan Patrick A. 
Published: October 2006

Abstract:To characterize the effect of glutamine on the release of glutamate, aspartate, and γ‐aminobutyric acid (GABA), rat hippocampal slices were superfused with different concentrations of glutamine or Ca2+. Amino acids released and retained were analyzed by HPLC. Glutamine (0.5 mmol/L) increased more than threefold the release of glutamate evoked by 50 mmol/L K+ in the presence of 2.6 mmol/L Ca2+ without a corresponding increase in glutamate content, while the release of aspartate was increased less and that of GABA not at all by glutamine. The evoked release of all three amino acids, including the enhanced release of glutamate in the presence of glutamine, was strongly dependent on Ca2+ concentrations between 0.1 and 2.6 mmol/L. The potentiation of glutamate release by glutamine reached a plateau at 0.25 mmol/L glutamine. Intermittent electrical field stimulation increased the release of only glutamate and this release was nearly doubled by glutamine. The increased release was Ca2+ dependent and tetrodotoxin (TTX) sensitive. Results suggest that extracellular glutamine promotes primarily the formation of releasable glutamate and this enhancement is dependent on extracellular Ca2+.
Stimulatory Effect of the D2 Antagonist Sulpiride on Glucose Utilization in Dopaminergic Regions of Rat Brain
Authors: Pizzolato Gilberto , Soncrant Timothy T. , Larson Denise M. , Rapoport Stanley I. 
Published: October 2006

AbstractLocal cerebral glucose utilization (LCGU) was measured, using the quantitative autoradiographic [14C]2‐deoxy‐d‐glucose method, in 56 brain regions of 3‐month‐old, awake Fischer‐344 rats, after intraperitoneal administration of sulpiride (SULP) 100 mg/kg. SULP, an “atypical” neuroleptic, is a selective antagonist of D2 dopamine receptors. LCGU was reduced in a few nondopaminergic regions at 1 h after drug administration. Thereafter, SULP progressively elevated LCGU in many other regions. At 3 h, LCGU was elevated in 23% of the regions examined, most of which are related to the CNS dopaminergic system (caudate‐putamen, nucleus accumbens, olfactory tubercle, lateral habenula, median eminence, paraventricular hypothalamic nucleus). Increases of LCGU were observed also in the suprachiasmatic nucleus, lateral geniculate, and inferior olive. These effects of SULP on LCGU differ from the effects of the “typical” neuroleptic haloperidol, which produces widespread decreases in LCGU in the rat brain. Selective actions on different subpopulations of dopamine receptors may explain the different effects of the two neuroleptics on brain metabolism, which correspond to their different clinical and behavioral actions.
Role of Thyroid Hormone and Nerve Growth Factor in the Development of Choline Acetyltransferase and Other Cell‐Specific Marker Enzymes in the Basal Forebrain of the Rat
Authors: Patel Ambrish J. , Hayashi Masao , Hunt Anthony 
Published: October 2006

AbstractThe effects of treatment with l‐thyroxine (subcu‐taneously 0.3 μg/g body weight daily from birth, i.e., day 1) and 2.5S nerve growth factor (NGF; intraventricularly 2 μg on 1, 3, 5, 7, and 9 postnatal days), separately and together, were studied on the biochemical development of different cell types in the basal forebrain of 10‐day‐old rats. The development of cholinergic, γ‐aminobutyric acid‐ergic (GABAergic), and glutamatergic neurons was monitored respectively in terms of choline acetyltransferase (ChAT), glutamate decarboxylase (GAD), and glutaminase activities, whereas glutamine synthetase (GS) and 2′,3′‐cyclic nu‐cleotide‐3′‐phosphohydrolase (CNPase) activities were used to judge the maturation of astroglial and oligodendroglial cells. Treatment with either thyroid hormone or NGF from birth significantly increased the expression of ChAT activity in the basal forebrain of neonatal rats. When both agents were administered to the same animal, in agreement with our earlier in vitro findings, the stimulation in ChAT activity was much greater than the sum of the individual effects. In hypothyroid rats, significant effects of NGF at the low doses used were not detectable, although the increase of ChAT activity induced by thyroxine was potentiated by NGF in these animals. Under the present experimental conditions neither thyroxine nor NGF treatment had an appreciable effect on the activities of glutaminase, GS, and lactate dehydrogenase. However, the administration of thyroxine markedly increased CNPase activity in normal rats, whereas in hypothyroid rats the effect on both CNPase and GAD was also significant. Similar elevations in CNPase and GAD activities were not observed after NGF treatment, suggesting that the effect of NGF was specific to the cholinergic cells. The observations provide further support for our proposal that subcortical cholinergic neurons are subject to regulation by an interaction between thyroid hormone and local humoural factors such as NGF.
Accumulation of Arachidonic Acid Cyclo‐ and Lipoxygenase Products in Rat Brain During Ischemia and Reperfusion: Effects of Treatment with GM1‐Lactone
Authors: Petroni A. , Bertazzo A. , Sarti S. , Galli C. 
Published: October 2006

AbstractThe aim of our study was to investigate the changes of various biochemical parameters (concentrations of lactate, free arachidonate, cyclo‐ and lipoxygenase products) in rat brain after ischemia and reperfusion and the effects of pre‐treatment with the ganglioside derivative GM1‐lactone on the same parameters. Ischemia was induced by reversible occlusion of common carotid arteries for 20 min, which in‐cluded a final 5 min of respiration of 5% oxygen in nitrogen. Reperfusion was obtained by removing the occlusion. Pre‐ischemic conditions were obtained on sham‐operated animals. Animals were killed by microwave irradiation of their heads. Brain levels of lactate and of free arachidonate were markedly increased after ischemia and returned to normal values at 5 min of reperfusion. Levels of the cyclooxygenase metabolites prostaglandin F2α, 6‐keto‐prostaglandin F1α, and thromboxane B2 were increased after ischemia, whereas levels of the lipoxygenase metabolite leukotriene C, (LTC4) did not. change. After reperfusion, a very' marked increase of the cyclooxygenase products occurred but not of LTC4. Treatment with GM1‐lactone prevented the elevation of cyclo‐ and lipoxygenase metabolites especially during reperfusion, with limited effects on lactate and free arachidonate levels.
The National Standard Reference Data System
Authors: Brady Edward L. , Wallenstein Merrill B. 
Published: October 2006

The National Standard Reference Data System is a government-wide effort to give to the technical community of the United States optimum access to the quantitative data of physical science, critically evaluated and compiled for convenience. This program was established in 1963 through action of the President's Office of science and Technology and the Federal Council for Science and Technology, acting upon the recommendation of the Council's Committee on Scientific and Technical Information. The National Bureau of Standards has been assigned responsibility for administering the effort. The general object of the system is to coordinate and integrate existing activities in data evaluation and compilation into a systematic comprehensive program, supplementing and expanding technical coverage when necessary, establishing and maintaining standards for the output of the participating groups, and providing mechanisms for dissemination of the output as required.
The NSRDS is a decentralized operation of nationwide scope, with central coordination by the Bureau; it comprises a complex of data centers and other activities carried on in government agencies, academic institutions, and nongovernmental laboratories. The independent operational status of existing data projects is maintained and encouraged. Data centers that are components of NSRDS produce compilations of critically evaluated data, critical reviews of the state of quantitative knowledge in specialized areas, and computations of useful functions derived from standard reference data.
Science and Politics: Free Speech Controversy at Lawrence Laboratory
Authors: Boffey Philip M. 
Published: October 2006

The Lawrence Radiation Laboratory, one of the nation's most distinguished scientific institutions, has been struck by a series of "free speech" controversies in recent months. The laboratory, which is operated by the University of California and is almost entirely funded by the Atomic Energy Commission, has facilities in two California locations, Berkeley and Livermore. Each has been under fire for allegedly stifling open discussion of controversial issues.
The Berkeley facility, a leading center for the study of high-energy physics and fundamental nuclear science, has been split by an internal debate over the right of scientists to hold formal political discussions at the laboratory during their lunch hours. The controversy has led to the banning of meetings, the circulating of petitions and counterpetitions bearing hundreds of names, the publishing of an underground newspaper, and the suspension of a controversial physicist.
The Livermore facility, a major center for developing nuclear weapons, has been accused of trying to muzzle two staff scientists who contend that existing radiation standards are too lax to protect the public from nuclear radiation hazards. Livermore has also been the target of demonstrations and of a lawsuit seeking to open the weapons laboratory to allow discussions between outsiders and staff scientists concerning the implications of weapons research. The article below discusses the controversy at the Berkeley laboratory, where only unclassified research is performed. A subsequent article will discuss the conflict at security-conscious Livermore.
Rainfall Enhancement by Dynamic Cloud Modification
Authors: Woodley William L. 
Published: October 2006

In summary, the following points are made:
1) There are essentially two approaches to seeding for rain inducement, static and dynamic.
2) The dynamic approach is effective in inducing growth and increasing precipitation from individually seeded convective clouds under specifiable conditions.
3) The static approach to seeding for precipitation increases is apparently not relevant to the summer cumuli of Florida and Missouri.
4) Regional seeding climatologies, including studies of natural freezing processes in convective clouds, should be completed before commencement of a seeding operation.
5) The results of a seeding operation are frequently better understood by stratification of the data, especially with respect to weather conditions. Precipitation increases from seeding are usually found under fair weather regimes with isolated showers, whereas decreases are often noted under naturally rainy conditions.
Crisis Management: Some Opportunities
Authors: Kupperman Robert H. , Wilcox Richard H. , Smith Harvey A. 
Published: October 2006

Modern crises present decision-makers with many agonizing management choices. Very often a crisis manager is confronted with a plethora of conflicting information and given very little time to choose an appropriate course of action. Although contemporary methods of systems analysis have been used in attempts to organize data and clarify options, they have generally been of little use in presenting an accurate picture of an opponent's values and perceptions. Thus it is clear that we must now make use of the improved communications and technological devices at our disposal if crises are to be avoided or resolved with minimum damage.
Our proposal to establish international model-oriented computer-assisted conferences is designed to promote greater cooperation and understanding among scientists and crisis managers of differing nations by enabling them to share images of themselves and one another. With better information and more rational options available, the chances of catastrophic misunderstanding or miscalculation can be meaningfully reduced. We have proposed a possible scenario for the initial implementation of such a system to combat famine, and hope that the same approach might be used in other areas over time. The ultimate goal is a system by which specialists of all persuasions cooperate so that international crises will be resolved on the bases of mutual benefits without resort to armed conflict.
The Proposed National Arboretum at Washington
Authors: Coville Frederick V. 
Published: October 2006

Nature.
The proposed national arboretum at Washington would contain a permanent living collection of trees and other outdoor plants for purposes of scientific research and education. It would include the trees, shrubs, and perennials used in forestry and horticulture, and the wild relatives of these plants. It would be a bureau of standards for horticulture. It would contain a water garden and a wildrice preserve, and it would serve incidentally as a bird sanctuary.

Economic value.
The arboretum would make the work of the Department of Agriculture more valuable to the country in many ways, but especially through plant breeding. The development of faster-growing timber trees, improved fruits, and disease-resistant plants generally, through the facilities afforded by the arboretum, would increase profoundly the agricultural wealth and welfare of the United States.

Location.
The Mount Hamilton and Hickey Hill tracts in the District of Columbia, together with the Anacostia River flats above Benning Bridge, constitute an admirable site for the arboretum, convenient in location and with a great variety of soils.

Cost.
About 400 acres of the proposed site is already owned by the government. It consists of marsh land, about to be drained by army engineers. The Mount Hamilton and Hickey Hill area, 408 acres, privately owned, was reported by the assessor in January, 1925, to be valued at $343,048, distributed among thirty owners.

Maintenance.
If the purchase of the Mount Hamilton and Hickey Hill tracts in the fiscal year 1927 is authorized, it is estimated that the cost of maintenance of the arboretum for the first three years would be as follows:

1927. Nothing
1928. $25,000
1929. $50,000
Studies in Microbial Thermogenesis
Authors: James Lawrence H. , James Lawrence H. 
Published: October 2006

An apparatus for the study of the "spontaneous" heat production in stored organic materials has been described. Experiments with commercial cornmeal and cracked yellow field corn have shown that temperatures above 60°C. can readily be produced under suitable conditions of moisture content, oxygen supply and insulation, and that marked heating does not take place in the absence of oxygen.
"Spontaneous" heat production is the result of oxidative reactions and will not take place to any marked extent in the absence of air or oxygen. Stored organic materials will not heat if retained under anaerobic conditions.
Saving Time And Storage in Breeding Sugar-Beets
Authors: Stewart George 
Published: October 2006

(1) By seeding sugar-beets in the greenhouse in early December or sooner, by exposing the growing beets to electric light for a few hours in the evening and by transplanting the roots into the field in spring, a seed generation may be produced every year.
(2) The beets must have reached a minimum stage of maturity at transplanting time, otherwise many may fail to produce seed.
(3) Storage for one month in a cellar before transplanting failed to give any observable benefit.