bluuebunny/crossref_metadata_2025_split huggingface dataset:
Muscarinic Cholinergic Receptor Subtypes in Hippocampus in Human Cognitive Disorders
Authors: Smith Carthage J. , Perry Elaine K. , Perry Robert H. , Candy John M. , Johnson Mary , Bonham James R. , Dick David J. , Fairbairn Andrew , Blessed Gary , Birdsall Nigel J. M. 
Published: October 2006

AbstractTotal muscarinic receptor levels, the levels of the subtypes exhibiting high and low affinity for pirenzepine, and the high‐ and low‐affinity agonist states of the receptor were investigated in hippocampal tissue obtained at autopsy from mentally normal individuals and the following pathological groups: Alzheimer's disease, Parkinson's disease, Down's syndrome, alcoholic dementia, Huntington's chorea, and motor‐neurone disease. A moderate decrease in the density of both high‐affinity pirenzepine and high‐affinity agonist subtypes was found in Alzheimer's disease, whereas a trend towards an increase in the overall muscarinic receptor density was apparent in the parkinsonian patients without dementia, mainly due to an increase in the low‐affinity agonist state; the differences between the Alzheimer's disease and nondemented parkinsonian cases were highly significant. As previously reported, the levels of both choline acetyltransferase and acetylcholinesterase were markedly reduced in both Alzheimer's disease and Parkinson's disease—with a greater loss of both enzymes in the demented subgroup of parkinsonian patients. Activities of the cholinergic enzymes were also extensively reduced in Down's syndrome, accompanied by a loss of high‐affinity pirenzepine binding. There were no significant receptor or enzyme alterations in the other groups studied. These observations suggest that in the human brain, extensive degeneration of cholinergic axons to the hippocampus, as indicated by a loss of cholinergic enzymes, is not necessarily accompanied by extensive muscarinic receptor abnormalities (as might be expected if a major subpopulation were presynaptic). Moreover, the opposite changes in muscarinic binding in Parkinson's and Alzheimer's diseases may be related to the greater severity of dementia in the latter disease. Key Words: Muscarinic receptor subtypes—Human hippocampus—Alzheimer's disease—Parkinson's disease —Down's syndrome. Smith C. J. et al. Muscarinic cholinergic receptor subtypes in hippocampus in human cognitive disorders.
Effect of Latent Iron Deficiency on 5‐Hydroxytryptamine Metabolism in Rat Brain
Authors: Shukla Arti , Agarwal K. N. , Chansuria J. P. N. , Taneja V. 
Published: October 2006

Abstract:Eight weeks of latent iron deficiency in weaned rats maintained on an experimental low iron content diet (18–20 mg/kg) did not significantly alter the packed cell volume and hemoglobin concentration; however, the hepatic and brain nonheme iron contents decreased by 66% and 21% (p < 0.001), respectively. The tryptophan concentration decreased by 31% and 34% in liver and brain, respectively, in rats on experimental diet (p < 0.01). The brain 5‐hydroxytryptamine and 5‐hydroxyindoleacetic acid contents were reduced by 21% and 23% (p < 0.01 and p < 0.02), respectively. However, in the brain, weight, protein, DNA, and the activities of monoamine oxidase, aldehyde dehydrogenase, and liver tryptophan oxygenase were found to remain unaltered.When rehabilitated with a diet containing 390 mg/kg iron, rats previously maintained on the experimental diet for 2 weeks showed partial recovery in tryptophan levels both in liver and brain. However, brain 5‐hydroxytryptamine and 5‐hydroxyindoleacetic acid levels remained unaltered. The hepatic iron content improved without any change in brain iron content. The latent iron deficiency produced significant alterations in the metabolism of 5‐hydroxytryptamine and brain iron content that could not be recovered 2 weeks after the iron rehabilitation.
Regulation of σ‐Receptors: High‐ and Low‐Affinity Agonist States, GTP Shifts, and Up‐Regulation by Rimcazole and 1,3‐Di(2‐Tolyl)guanidine
Authors: Beart Philip M. , O'Shea Rbss D. , Manallack David T. 
Published: October 2006

AbstractThe regulation of the central σr‐binding site was investigated using both in vitro and in vivo manipulations in conjunction with radioligand binding. The displacement of the binding of R(+)‐[3H]3‐[3‐hydroxyphenyl][N‐(l‐pro‐pyl)piperidine (R(+)‐{3H]3‐PPP} to cortical homogenates by a range of drugs was consistent with the site labelled being a σ‐receptor. (+)‐SKF 10,047, (‐)‐SKF 10,047, (±)‐cyclazo‐cine, phencyclidine, and dexoxadrol displaced R(+)‐[3H]3‐PPP with pseudo‐Hill coefficients of less than . Further analysis employing nonlinear curve fitting techniques demonstrated that displacement data for these compounds were described better by a model whereby R(+)‐[3H]3(‐PPP was displaced from two discrete sites; approximately 6[5% of the total sites were in the high‐affinity state. In the presence of 10 mM Mg2+ and 0.3 mM GTP, displacement curves for (+)‐SKF 10,047 and (±)‐cyclazocine were shifted to the right. These findings were due to the shift of some 15% of the high‐affinity binding sites to a low‐affinity state. Saturation experiments revealed that 0.3 mM GTP acted competitively to decrease the affinity of R(+)‐[3H]3‐PPP for the σ suites. The σ‐binding site was thus likely to be linked to a guanine nucleotide regulatory (G) protein. Thus σ drugs could be subdivided on the basis of their GTP sensitivity and psdudo‐Hill coefficients, and by analogy with other receptors R(+)‐3‐PPP. (+)‐SKF 10,047, and (±)‐cyclazocine, may be putative σ‐agonists. l,3‐Di(2‐tolyl)guanidine (DTG), rimcazole, and haloperidol displaced R(+)‐[3H]3‐PPP with pseudo‐Hill coefficients of approximately unity and thus may be σ‐antagonists. Subchronic treatment with rimcazole was characterized by slight sedation and a concomitant up‐regulation, with a decrease in the affinity, of σr‐binding sites. The schedule of rimcazole also increased dopamine turnover in the nucleus ac‐cumbens; both the concentration of 3,4‐dihydroxyphenyl‐acetic acid (DOPAC) and the DOPAC/dopamine ratio were elevated. DTG produced similar alterations to the binding parameters of the σ‐binding site; however, changes were not observed in general behavior or accumbal dopamine turnover. (T‐Receptors are likely to be linked to a G protein and are functionally involved in the CNS.
Tyrosine Hydroxylase Content of Residual Striatal Dopamine Nerve Terminals Following 6‐Hydroxydopamine Administration: A Flow Cytometric Study
Authors: Wolf Marina E. , Zigmond Michael J. , Kapatos Gregory 
Published: October 2006

AbstractFluorescence‐activated cell sorting based on im‐munolabeling with a monoclonal antibody to tyrosine hydroxylase and a fluorescein‐conjugated secondary antibody was used to identify striatal synaptosomes derived from ni‐grostriatal dopamine nerve terminals. The amount of tyrosine hydroxylase immunoreactivity in dopaminergic striatal synaptosomes prepared from control rats was compared to the amount in dopaminergic synaptosomes prepared from rats that had received intraventricular injections of 6‐hydroxy‐dopamine. Although the absolute number of dopaminergic synaptosomes was decreased in lesioned animals, those residual dopamine terminals present contained more tyrosine hydroxylase than did dopamine terminals from control rats. Both the decrease in the absolute number of dopamine terminals and the increase in tyrosine hydroxylase immunoreactivity in residual terminals were proportional to the extent of the lesion, as determined by measurement of striatal dopamine levels. These results suggest that an increase in the amount of tyrosine hydroxylase protein in residual terminals may represent one compensatory mechanism by which residual dopamine neurons maintain normal striatal function after partial destruction of the nigrostriatal dopamine projection.
Monoamine Oxidase (MAO)‐A but Not MAO‐B Inhibitors Potentiate Tyramine‐Induced Catecholamine Release from PC12 Cells
Authors: Youdim Moussa B. H. 
Published: October 2006

Abstract:The previous report that PC12 (pheochromocytoma) cells have a K+‐induced, as well as a tyramine‐induced, catecholamine release mechanism has been confirmed. Selective monoamine oxidase (MAO)‐A (clorgyline and moclobemide) and not MAO‐B inhibitors (l‐deprenyl, AGN 1135, and Ro 16–6491) potentiate the catecholamine‐releasing action of tyramine significantly more than that of K+. The potentiation of tyramine‐induced [3H]noradrenaline release from PC 12 cells by MAO‐A inhibitors has been linked to the presence of MAO‐A in these cells, for which tyramine and noradrenaline are substrates. In the above respects, it is the PC 12 cell that resembles more closely the peripheral adrenergic neuron, rather than the chromaffin cell, which is endowed with MAO‐B and lacks the tyramine‐releasable pool of catecholamines.
Effects of Choline Administration on In Vivo Release and Biosynthesis of Acetylcholine in the Rat Striatum as Studied by In Vivo Brain Microdialysis
Authors: Koshimura Kunio , Miwa Soichi , Lee Ken , Hayashi Yasunori , Hasegawa Hiroshi , Hamahata Keigo , Fujiwara Motohatsu , Kimura Mieko , Itokawa Yoshinori 
Published: October 2006

Abstract:The purpose of the present study is to clarify the effects of the administration of choline on the in vivo release and biosynthesis of acetylcholine (ACh) in the brain. For this purpose, the changes in the extracellular concentration of choline and ACh in the rat striatum following intracerebroventricular administration of choline were determined using brain microdialysis. We also determined changes in the tissue content of choline and ACh. When the striatum was dialyzed with Ringer solution containing 10 μM physostigmine, ACh levels in dialysates rapidly and dose dependently increased following administration of various doses of choline and reached a maximum within 20 min. In contrast, choline levels in dialysates increased after a lag period of 20 min following the administration. When the striatum was dialyzed with physostigmine‐free Ringer solution, ACh could not be detected in dialysates both before and even after choline administration. After addition of hemicholinium‐3 to the perfusion fluid, the choline‐induced increase in ACh levels in dialysates was abolished. Following administration of choline, the tissue content of choline and ACh increased within 20 min. These results suggest that administered choline is rapidly taken up into the intracellular compartment of the cholinergic neurons, where it enhances both the release and the biosynthesis of ACh.
Identification of Glucagon Receptors in Rat Retina
Authors: Fernandez‐Durango R. , Sanchez D. , Fernandez‐Cruz A. 
Published: October 2006

Abstract:In this study, we characterize the glucagon receptors on rat retinal particulate preparations. The specific binding of 125I‐glucagon was saturable and reversible. Apparent equilibrium conditions were established within 30–45 min. Analysis of binding data is compatible with the existence of two classes of binding sites: a high‐affinity class with a KD of 7 ± 0.8 nM and a Bmax of 2.3 ± 0.2 pmol/mg of protein and a low‐affinity class with a KD of 84.4 ± 2.5 nM and a Bmax of 16.5 ± 2.3 pmol/mg of protein. The 125I‐glucagon binding to retinal particulate preparation was not inhibited by 1 μM concentrations of insulin, atrial natriuretic factor, angiotensin II, somatostatin, and vasoactive intestinal peptide. However, synthetic human pancreatic growth hormone‐releasing factor, hGRF‐44, inhibited binding, although the concentration required for half‐maximal displacement was 10‐fold higher than that for native glucagon. Glucagon binding was GTP sensitive. Inclusion of 0.1 mM GTP in the binding assay produced an increase in the concentration of unlabeled glucagon required for half‐maximal displacement of 125I‐glucagon, from 23 to 220 nM. Glucagon stimulated adenylate cyclase formation in retinal particulate preparations. The concentration of glucagon required for half‐maximal activation of retinal adenylate cyclase was 16.2 nM. These results suggest that glucagon may play a role as a neurosignal transmitter in rat retina.
Neurotensin Binding to Dopamine
Authors: Adachi Derek K. , Kalivas Peter W. , Schenk James O. 
Published: October 2006

Abstract:Rotating disk electrode voltammetry at glassy carbon electrodes and ultraviolet/visible spectroscopy were used to demonstrate that dopamine binds to neurotensin with a dissociation constant of 7.5 × 10‐8. By measuring the binding constants of various neurotensin analogs, it was found that the ‐Arg8‐Arg9‐portion of the neurotensin sequence is critical for binding dopamine. Neurotensin also formed a complex with 4‐ethylcatechol, 4‐methylcatechol, 3‐methoxytyramine, and norepinephrine. Although changes in the side chain did not alter the binding constant, methoxylation of the catechol moiety significantly increased the dissociation constant. These data along with additional studies of dopamine interactions with arginine derivatives suggest that the guanidino groups of arginine and the catechol hydroxyls of dopamine are responsible for mediating the observed binding. It is hypothesized that the capacity of neurotensin to bind directly to dopamine may be partly responsible for its previously observed antagonism of dopamine‐induced locomotor activity.
Autoradiographic Visualization of A1 Adenosine Receptors in Rat Brain with [3H]8‐Cyclopentyl‐1,3‐Dipropylxanthine
Authors: Weber Ruthild G. , Jones C. Richard , Lohse Martin J. , Palacios José M. 
Published: October 2006

Abstract:A1 adenosine receptors were labeled in rat brain sections with the antagonist [3H]8‐cyclopentyl‐1,3‐dipropylxanthine ([3H]DPCPX) and visualized at the light microscopic level using autoradiography. The specific binding of [3H]DPCPX to the sections showed the pharmacological characteristics of A1 adenosine receptors and was accompanied by very low levels of nonspecific binding. Whereas GTP had no significant effect on [3H]DPCPX binding to rat brain membranes, the addition of 100 μM GTP increased the apparent affinity of [3H]DPCPX to tissue sections fivefold (from 1.83 to 0.35 nM), enhancing it to the affinity measured in membranes. However, GTP altered neither the binding capacity nor the distribution of binding sites in tissue sections. It is suggested that a competitive antagonism with endogenous adenosine explains the lower affinity of [3H]DPCPX in the absence of GTP. The autoradiographic pattern of [3H]DPCPX binding was characteristic for A1 adenosine receptors. Distinct labeling of the different layers of the cerebellar cortex was shown by photomicrographs generated with the coverslip technique. In addition, several fiber tracts were found to be labeled. The high selectivity for A1 adenosine receptors and low nonspecific binding of [3H]DPCPX, the ability to produce high‐resolution autoradiograms, together with the fact that the effects of endogenous adenosine can be eliminated by the addition of GTP make [3H]DPCPX a very useful tool in the autoradiographic study of A1 adenosine receptors.
Extremely compact massive galaxies at z ∼ 1.4
Authors: Trujillo I. , Feulner G. , Goranova Y. , Hopp U. , Longhetti M. , Saracco P. , Bender R. , Braito V. , Della Ceca R. , Drory N. , Mannucci F. , Severgnini P. 
Published: October 2006

Abstract
The optical rest-frame sizes of 10 of the most massive (∼5 × 1011h−270 M⊙) galaxies found in the near-infrared MUNICS survey at 1.2 &lt; z &lt; 1.7 are analysed. Sizes are estimated in both the J and K′ filters. These massive galaxies are at least a factor of 4+1.9−1.0 (±1σ) smaller in the rest-frame V-band than local counterparts of the same stellar mass. Consequently, the stellar mass density of these objects is (at least) 60 times larger than that of massive ellipticals today. Although the stellar populations of these objects are passively fading, their structural properties are rapidly changing since that redshift. This observational fact disagrees with a scenario where the more massive and passive galaxies are fully assembled at z∼ 1.4 (i.e. a monolithic scenario) and points towards a dry merger scenario as the responsible mechanism for the subsequent evolution of these galaxies.
Translocation of Carbohydrates in Maize
Authors: Loomis W. E. 
Published: October 2006

(1) The pith of maize shows a changing sugar content with changing sugar movement in the phloem which would not be predicted from our present picture of the morphology of the maize bundle.
(2) By all tests of changing concentration, sucrose is the important carbohydrate of translocation in maize. Interconversion of the several sugars is too rapid, however, to permit a final conclusion.
(3) An hypothesis of translocation in maize must not only account for movement against an osmotic gradient, but against gradients of each of the substances which might possibly be translocated. Such secretory translocation certainly occurs between the leaf mesophyll and the phloem and probably along the phloem itself.
(4) Translocation in maize is polarized, out of the leaf, out of the xylem and toward the developing fruit. Polarized translocation out of the leaf is established during the later stages of tissue differentiation. Polarized translocation toward the fruit is established in the early phases of embryo development and does not develop in the absence of pollination.
Thiamine Deficiency and High Estrogen Findings in Uterine Cancer and in Menorrhagia
Authors: Ayre J. Ernest , Bauld W. A. G. 
Published: October 2006

The finding of abnormal estrogenic activity coupled with thiamine deficiency in cases of menorrhagia and uterine cancer suggests a possible etiological correlation between the dietary deficiency, the abnormal estrogen level, and the pathological lesion.
The specific element deficient in these cases was thiamine, while the other B factors were normal.
Preliminary report of the evidence is made in this small series while more extensive studies on a large series of cases are being pursued.
Cornification in cytology smears was used to study estrogenic activity, since the present study was prompted by cytological findings; the method is simple, practical, and reasonably accurate. The urinary estimation measures only the amount excreted, and if liver impairment actually is present, the quantity excreted would not give a true index of the amount retained in the body.
Further studies are being undertaken in which estrogenic, urinary, and cornification levels are being compared before and after thiamine administration in cases proven to be deficient.
Use of Oral Contraception in the United States, 1965
Authors: Ryder Norman B. , Westoff Charles F. 
Published: October 2006

This is the first report from the National Fertility Study, 1965, a survey of the reproductive behavior of a national sample of married women, under the age of 55, living with their husbands. The report presents basic data on the use of oral contraception by women under the age of 45, in relation to age, parity, education, race, and religion. The study leads to certain conclusions, as follows. Present, past, and prospective use vary inversely with the age of the woman and directly with the number of years of schooling; the majority of young women with college training have already used the oral contraceptive. Use by Negroes is somewhat less extensive than use by whites, particularly for ages below 25; some of this difference is explainable by concomitant racial differences in educational level. Negroes seem less likely than whites to use oral contraception for timing early births, and more likely, when they do use it, to be attempting to terminate their fertility. The same observation holds for white Catholics in relation to white non-Catholics. Although the extent of use may be lower among Catholics than non-Catholics, the proportion of Catholics who report use is substantial indeed in view of the persisting theological controversy.
The prospects for increased use of oral contraception seem very good at present, but they may be limited by further developments in the technology of fertility regulation. Meanwhile the birth rate has declined substantially. Although much sophisticated analysis of other data from the survey will be required to determine the extent of the contribution of oral contraception to this decline, the findings presented here suggest that the contribution is substantial for young married couples. The major effect on the couple's eventual number of children may be less than the effect on the time pattern of childbearing; in any event, both lower eventual parity and delayed fertility contribute to a decline in the numbers of births from year to year. Whatever the intent may be, it is apparent that young American couples have adopted a new means for achieving their reproductive goals.
A Gorilla-Sized Ape from the Miocene of India
Authors: Simons E. L. , Pilbeam David 
Published: October 2006

A large ape existed in India at the close of the Miocene or the beginning of the Pliocene epochs; this ape shows a complex of anatomical structures at the opposite pole from its contemporary,Ramapithecus. Although found in the same beds, the two seldom occur at the same exact sites and levels. Considering the thickness of these beds, recovery close to Haritalyangar does not, of itself, prove sympatry of these two different kinds of Hominoidea. However, both are definitely present at one recently located site representing, most probably, a death assemblage.Observations by the authors on scores of chimpanzees suggest that, at least in this ape, wear gradients on molar crowns exist, but that the wear differential between adjacent molars is almost never raised to the degree seen in mostRamapithecus.Dryopithecus indicusandD. fontani(from southern France), in contrast, show almost no wear gradient at all; that is, whether an individual is dentally young or old, wear on all three molars and the two premolars has proceeded to about the same degree. It is of considerable importance in understanding hominid phylogeny to be able to stress that an ape known to be contemporary withRamapithecusshows far less differential wear than does the hominid. This, in turn, strongly suggests that the molar eruption sequence ofD. indicuswas rapid, while that of the hominid was delayed. The implication is that, as far back as the late Miocene, the hominid maturation period was lengthened, relative to that of apes. A further fact which emerges is that the rate of interstitial wear was faster in the Haritalyangar ape than in the hominid contemporary with it. This, together with its large size, flatness of unworn tooth crowns, and other associated characters, suggests thatD. indicusis in, or close to, the ancestry ofGigantopithecus. From this emerges yet another object lesson, emphasizing the caution one has to observe in the manner and method by which ancient and modern apes are compared and contrasted. None of the species of Hominoidea dealt with here, whether pongid (D. indicusandPan troglodytes) or hominid (R. punjabicus), accumulates either interstitial or crown wear at the same rate or in the same manner.