bluuebunny/crossref_metadata_2025_split huggingface dataset:
Assignment of genes for human monoamine oxidases A and B to the X chromosome
Authors: Kochersperger L.M. , Parker E.L. , Siciliano M. , Darlington G.J. , Denney R.M. 
Published: January 2005

AbstractMonoclonal antibodies that immunoprecipitate human monoamine oxidase (MAO) A or human MAO B, but not the corresponding mouse enzymes, were used to assay for the presence of immunoprecipitable MAO A or MAO B (presumably coded by the respective human genes) in mouse‐human hybrid somatic cell lines containing small numbers of human chromosomes. The results were as follow: (1) Extracts of a human lymphoblastoid x mouse hepatoma hybrid line that retained the human X chromosome contained immunoprecipitable MAO B, while a similar hybrid line that contained the same human chromosomes, except for the human X, did not. (2) Extracts of a human fibroblast x mouse neuroblastoma hybrid cell line, whose human chromosomal material consisted solely of the X, contained both immunoprecipitable MAO A and MAO B. Extracts of a related hybrid line, whose human chromosomal material consisted solely of an autonomous fragment and a fragment translocated to a mouse chromosome, contained immunoprecipitable MAO A. However, the level of immunoprecipitable MAO B activity in extracts of this hybrid was low or undetectable. (3) Among extracts of 33 human fibroblast x mouse hepatoma hybrids that had been selected for expression of the X‐linked human enzyme HPRT, 60% contained immunoprecipitable MAO B. This figure was comparable to the 58% that expressed the X‐linked human isozyme for glucose‐6‐phosphate dehydrogenase (G6PD). When 11 of these hybrid lines, which contained immunoprecipitable MAO B and human HPRT, were selected for loss of HPRT, all lost immunoprecipitable MAO B in addition to HPRT.These data demonstrate that genes controlling the expression of MAO A and MAO B, which can be immunoprecipited with the human‐specific monoclonal antibodies, are located on the human X chromosome. Properties of the immunological epitopes recognized by the monoclonal antibodies suggest that the X‐linked genes detected in this study are probably structural genes for the enzymes.
Substance P neurons sprout in the cervical spinal cord of the wobbler mouse: A model for motoneuron disease
Authors: Vacca‐Galloway L.L. , Steinberger C.C. 
Published: January 2005

AbstractThe mutant mouse, wobbler, possesses a recessively inherited degeneration of motoneurons and other ventral horn cells in the cervical spinal cord, and therefore it has been proposed as an animal model of human motoneuron disease. Affected mice have been identified by behavioral tests that also determined the extent of the motor deficit. The results from these tests were combined and used to define distinct stages of the disease process that could then be correlated histochemically with the amount of acetylcholinesterase (AChE) staining in the cervical spinal cord. AChE is used as a marker for cholinergic neurons and is known to hydrolyze the neuropeptide modulator substance P (SP). SP, a peptide neuromodulator of primary afferent transmission in the dorsal horn, excites motoneurons in the ventral horn, and may posses secondary frnctions in neuronal maintenance. Therefore, the levels of immunoreactive (IR) SP and AChE were examined in an attempt to determine the possible interaction between these factors in motoneuron degeneration.By enzyme histochemistry, the cervical spinal cord, taken from wobbler mice at behaviorally identified stages of the motor deficit, exhibited decreased levels of AChE throughout the ventral horn. The decrease detected in the AChE staining intensity was linear and correlated with the decrease in the number of AChE‐positive cells in the ventral cervical spinal cord, as the motor deficit progressed. Presumably, the continual decrease in AChE staining represents the degeneration of cholinergic perikarya and neuronal processes in the ventral horn as the motoneuron disease proceeds.At two well‐established stages of the motor deficit, the amount of immunoreactive SP increased in the ventral horn compared with the control mice. The elevated levels of immunoreactive SP suggest sprouting may have occurred preceding, or in response to, the motoneuron degeneration. Several additional hypotheses are discussed in respect to phenomena that might contribute to the increase of immunoreactive SP in the degnerating ventral horn of the wobbler mouse.
Dissimilarities between benzodiazepine‐binding sites and adenosine uptake sites in astrocytes and neurons in primary cultures
Authors: Bender A. S. , Hertz L. 
Published: January 2005

AbstractThe question whether the benzodiazepine receptor site in astrocytes or in neurons might be identical to the adenosine uptake site was studied by determining pharmacological profiles, inhibition types, and the effects of benzodiazepine antagonsts in primary cultures of either astrocytes or neurons. Fourteen different benzodiazepines and five different adenosine uptake inhibitors displaced [3H] diazepam and inhibited adenosine uptake in both astrocytes and neurons. However, the rank orders (determined as IC50 values) with which these two parameters were affected were profoundly different, indicating dissimilarities between these two sites. For several of the compounds a difference in inhibition type (competitive vs. noncompetitive) was observed between the benzodiazepine‐binding site and the adenosine uptake site in astrocytes and/or neurons, which further corroborated the conclusion of a difference between the benzodiazepine‐binding site and the adenosine uptake site. Finally, the neuronal benzodiazepine antagonists RO 15‐1788 and CGS‐8216 and the astrocytic benzodiazepine antagonist PK 11195, which reverse the action of benzodiazepines, were not able to reverse inhibition of adenosine uptake by diazepam but exerted an inhibitory effect of their own.
Denervation of serotonergic fibers in the hippocampus induced a trophic factor which enhances the maturation of transplanted serotonergic neurons but not norepinephrine neurons
Authors: Zhou F. C. , Auerbach S. , Azmitia E. 
Published: January 2005

AbstractThe trophic effects of specific denervation on the growth and survival of fetal serotonergic (5‐HT) or norepinephrinergic (NE) neurons grafted into the hippocampus were assessed by means of two transplantation paradigms. In the first, fetal raphe cells (containing 5‐HT neurons) were transplanted into the control hippocampus. In the second, the transplantation was performed 2 weeks after the specific removal of 5‐HT afferents to the hippocampus with 5,7‐dihy‐droxytryptamine (5,7‐DHT). We found that a month after transplantation, the number of 5‐HT immunoreactive neurons was not significantly different between the two experimental paradigms. However, transplanted raphe neurons had 400% more 5‐HT synaptosomal high‐affinity uptake and 380% higher content of 5‐HT in the hippocampus with prior 5,7‐DHT lesion than in control hippocampus. Furthermore, immunocytochemistry showed that the transplanted 5‐HT neurons had denser processes and varicosities in the hippocampus with lesion than in control hippocampus. The somatic area of the neurons with these denser processes and varicosities was 42% larger than that of control group. A greater 5‐HT level could be achieved if transplanted neurons in the control hippocampus were treated with the supernatant extracted from the hippocampus with 5,7‐DHT lesion.In contrast, the NE level of the implanted fetal locus ceruleus (containing NE neurons) was not significantly higher in the 5‐HT denervated hippocampus than in control hippocampus a month after transplantation. These results suggest that 5‐HT denervation in the hippocampus induces a trophic substance which promotes the maturation rather than survival of 5‐HT neurons but not NE neurons.
Alteration of calmodulin distribution does not accompany dopaminergic supersensitization of the mouse striatum
Authors: May P. C. , Osterburg H. H. , Mandel R. J. , Morgan D. G. , Randall P. K. , Finch C. E. 
Published: January 2005

AbstractMembrane‐bound calmodulin increases following dopaminergic supersensitization of the rat striatum. To assess the generality of this relationship, mice were treated with two different supersensitization paradigms. Calmodulin levels and subcellular distribution were determined by radioimmunoassay. Chronic haloperidol treatment increased striatal D2 dopamine receptor density by 25% but had no effect on membrane‐bound calmodulin levels. Similarly, 6‐hydroxy‐dopamine (6‐OHDA) lesions depleted striatal dopamine content > 95% without affecting membrane‐bound calmodulin. In contrast, soluble calmodulin levels decreased by 15% in the 6‐OHDA‐lesioned striatum, suggesting that soluble calmodulin is enriched in presynaptic dopaminergic terminals. We conclude that dopaminergic supersensitization can occur in the mouse striatum in the absence of any change in calmodulin distribution.
Comparisons of proteins and glycoproteins in neuronal plasma membranes, axolemma, Synaptic Membranes, and oligodendroglial plasma membranes
Authors: Hampson D. R. , Poduslo S. E. 
Published: January 2005

AbstractNeuronal membranes are unique in that they consist of several functionally disinct segments: the perikaryal plasma membrane, the axolemma, the synaptic membrane, and the dendritic membrane. Methods are now available to isolate the first three types of membranes as well as to isolate oligodendroglial plasma membranes. The protein and glycoprotein compositions for each set of membranes were analyzed by silver staining after separation by SDS polyacrylamide gradient gel electrophoresis and by radiolabeled lectin binding to glycoproteins transferred to nitrocellulose. Analysis of the composition of each set of membranes reveals that they are all complex structures consisting of heterogeneous mixtures of proteins and glycoproteins, ranging in molecular weights from < 200,000 to 15,000. Each membrane fraction presents a unique pattern of staining and of lectin binding. As there were proteins and glycoproteins in common among the membranes, there were also differences. Synaptic membranes and axolemma appeared to have more proteins of higher molecular weight than the other membranes. Neuronal plasma membranes had a major concanavalin A binding glycoprotein at 79 kDa, which was not found in the other membranes. The three neuronal membrane fractions had a common wheat germ agglutinin binding glycoprotein at 82 kDa. The most interesting finding was the intense binding of neuronal plasma membrane glycoproteins to Ulex europaeus, suggesting high levels of fucose‐containing glycoproteins.
Effects of coculture on the morphology of identified raphe and substantia nigra neurons from the embryonic rat brain
Authors: König N. , Han V. , Lieth E. , Lauder J. 
Published: January 2005

AbstractThe substantia nigra (SN) is one of the earliest targets of the 5‐HT neurons of the raphe nuclei (RN). To test the hypothesis that embryonic 5‐HT and catechol‐amine neurons may influence the differentiation of their target cells or source neurons, we have produced dissociated cell cultures from embryonic day 14 (E14) rat rhombencephalon (containing the serotonergic RN) and mesencephalon (containing the dopaminergic substantia nigra, SN). These cells were grown for 6 days in vitro, either as single cultures (RN or SN) or cocultures (RN + SN). Effects of coculture on the morphological development of neurons immunoreactive (IR) for 5‐HT or tyrosine hydroxylase (TH) were studied by measuring a series of morphological parameters related to size of the cell body and dendritic field, as well as to the complexity of neurites within this field, using computer‐assisted morphometry. Increases in a number of these parameters were found in cocultures compared to single cultures for both types of monoamine neurons, but a greater number of parameters were increased for TH‐IR cells, including size of the cell body. Although this might suggest that there was a greater effect of coculture on the TH‐IR (dopaminergic) cells of the SN than on the 5‐HT‐IR cells of the RN, we must consider the fact that a significant population of TH‐IR cells were present in single RN cultures, which contributed to the total population of TH‐IR cells in cocultures. Indeed, when morphometric parameters for TH‐IR cells in RN and SN single cultures were compared, it was found that TH‐IR cells from the RN were generally larger and more complex than those from the SN. Therefore, an analysis was made of which parameters were significantly increased for TH‐IR cells in cocultures compared to single cultures from both SN and RN. This was the case for two parameters: cell body size and absolute field area, indicating that these increases were probably due to the effects of coculture itself rather than to contamination by the larger and more complex TH‐IR cells from the RN. It is impossible to ascertain, however, whether this effect was on cells from the RN, SN, or both. Coculture effects on 5‐HT‐IR cells were easier to analyze, since no such cells were found in single cultures of SN. Three parameters were consistently increased for 5‐HT‐IR cells in coculture: cumulative length of all segments, segment length density, and absolute field area. This indicates that 5‐HT‐IR cells in coculture had larger dendritic fields that contained a more complex array of neurites than their counterparts in single cultures. In sum, coculture seems to promote the growth of both 5‐HT and TH‐IR neurons, but in different ways and to different degrees. These results suggest that some factor or factors related to growth of these monoamine neurons are altered when the rhombencephalon and mesencephalon are cultured together. The exact nature of this developmental signal remains to be determined.
Development of innervation within syngeneic thymus tissue transplanted under the kidney capsule of the nude mouse: A light and ultrastructuarl microscope study
Authors: Bulloch K. , Cullen M. R. , Schwartz R. H. , Longo D. L. 
Published: January 2005

AbstractThe devloping thymus, prior to the onset of its functional and structural organization, is innervated by the autonomic nervous system (ANS). The present study extends these earlier findings by analyzing at the light and ultrastructural microscope level the distribution of ANS nerves within normal 18‐day‐old embryo thymus, adult thymus, and thymic tissue transplanted under the kidney capsule of syngeneic nude mice. The results of this study showed that prior to birth the murine thymus is innervated by AChE‐positive fibers that are distributed at the corticomedullary boundaries and throughout the adjacent cortex, as well as to cells beneath the thymic capsule. This pattern of distribution remains constant during adult life. The examination of the various thymic tissues by ultrastructural analysis demonstrated that myelinated and nonmyelinated fiber bundles penetrate the thymic capsule and the interface between the kidney and the thymus transplant. The myelinated fibers measured 2 m̈m or less in diameter; the nonmyelinated fibers were 1 m̈m in diameter. Myelination did not accompany the nerves into the parenchyma of the normal gland but was observed in the intralobular trabeculae of the transplanted thymus. Subcapsular nerves form a network that terminates among the thymocytes, whereas intrathymic nerves enter the parenchyma in bundles along the vasculature and interlobular septa before penetrating into the deeper layers of the thymic cortex. Some larger nerve fibers terminate in the corticomedullary boundaries and in the interlobular septa. Smaller fibers form en passant boutons near parenchymal cells. The innervation of both the normal thymus prior to the onset of thymic immune function supports a role for ANS innervation in the development of thymic competency.
Noradrenergic sympathetic innervation of the spleen: I. Nerve fibers associate with lymphocytes and macrophages in specific compartments of the splenic white pulp
Authors: Felten D. L. , Ackerman K. D. , Wiegand S. J. , Felten S. Y. 
Published: January 2005

AbstractSympathetic noradrenergic nerve fibers, stained with antiserum for tyrosine hydroxylase (TH), richly innervate the splenic white pulp. These fibers distribute with the vascular and trabecular systems, and associate mainly with the central artery and its branches, the periarteriolar lymphatic sheath (PALS), the marginal sinus, and the parafollicular zone, with occasional delicate fibers also present in the follicles. Simultaneous staining of TH‐positive nerve fibers and markers for specific lymphoid cells has shown several regions of contact between nerves and lymphocytes or macrophages. The TH‐positive nerve fibers in the plexuses around the central arterial system and in the PALS are present among T lymphocytes (OX‐19‐positive cells) including both T helper and T suppressor cells, and interdigitating cells. At the marginal sinus, TH‐positive fibers run adjacent to macrophages (ED3‐positive cells), B lymphocytes (IgM‐positive), and intensely fluorescent IgM‐positive cells. Along the parafollicular zone, TH‐positive nerve fibers run adjacent to T lymphocytes, peripheral follicular B lymphocytes, and intensely fluorescent IgM‐positive cells. Within some follicles, delicate fibers end adjacent to both T and B lymphocytes. These relationships suggest a direct interaction between norepinephrine release from the TH‐positive nerve terminals and the lymphocytes and macrophages closely associated with them, and focuses attention on the potential neural modulation of related functions such as T and B lymphocyte entry into the spleen and antigen capture (marginal zone), antigen presentation and T cell activation (PALS), B cell activation (parafollicular zone and marginal zone), and lymphocyte egress (outer marginal zone).
Modulation of T‐Suppressor cell activity by central nervous system catecholamine depletion
Authors: Cross R. J. , Brooks W. H. , Roszman T. L. 
Published: January 2005

AbstractThis study extends our previous findings, which indicate that depletion of CNS catecholamines has a marked inhibitory effect on humoral immune responsiveness. These data show that depletion of CNS catecholamines by injection of 6‐hydroxydopamine (6‐OHDA) into the cisterna magna in conjunction with immunization enhances activity of a population of splenic T‐suppressor cells as evidenced by the transfer of these cells to normal recipients. Increased suppressor cell activity does not results solely from 6‐OHDA treatment, but rather requires concomitant immunization. Further characterization shows that these suppressor cells are not antigen specific. Hypophysectomy abrogates the effect of 6‐OHDA injection suggesting that catecholamine depletion modulates immune function via the release of pituitary hormones. Thus, depletion of CNS catecholamines impairs immune responsiveness by inducing enhanced T‐suppressor cell activity, providing additional evidence of the involvement of the CNS in gegulation of immune responsiveness.
Vasoactive intestinal peptide 1‐12: A ligand for the CD4 (T4)/human immunodeficiency virus receptor
Authors: Sacerdote P. , Ruff M. R. , Pert C. B. 
Published: January 2005

AbstractA five‐amino‐acid (TDNYT) sequence of vasoactive intestinal polypeptide (VIP) shares homology with the proposed attachment sequences of the human immunodeficiency virus (HIV). Synthetic peptides with these wequences have previously been shown to block viral envelop (gp120) binding and HIV infectivity and to serve as agonists of the CD4 (or T4) receptor. Utilizing an in vitro human monocyte chemotaxis bioassy we examined novel synthetic VIP and gp120 sequences and characterized their pharmacological activities on minocyte chemotaxis. CD4 receptor activity is primarily specified by N‐terminal (VIP [1–12]) amino acids. The profound immunosuppression of AIDS is not easily explained solely by virus infection. Recently described immunological functions of VIP are similar to some of the immunological abnormalities shown by patients with AIDS. An overproduction of a VIP‐like molecule from viral sources (e.g. gp120) could explain some of the immune system impairments which have been described in AIDS.
Purification of the 33,000‐dalton ligand binding‐protein constituent of the lymphoblast substance P receptor
Authors: McGillis J. P. , Organist M. L. , Scriven K. H. , Payan D. G. 
Published: January 2005

AbstractSubstance P (SP) acts as an immunoregulator by binding to specific funcitonal cell surface receptors on a subpopulation of human T‐helper lymphocytes. Receptors with similar properties have also been characterized on the human IM‐9 B‐lymphoblast cell line. Four distinct proteins of molecular weight (MW) 33,000, 58,000, 78,000, and 116,000 can be specifically affinity labeled using [125I]‐SP Bolton‐Hunter reagent and disuccinymidyl suberate (DSS). Peptide‐mapping studies of these individually purified affinity labeled proteins have shown that the 33,000 MW membrane protein is present in the higher molecular weight cross‐linked proteins. In the present studies, the 33,000 MW affinity‐labeled protein was purified using semi‐preparative sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS‐PAGE) followed by high‐performance hydroxylapatite chromatography. Starting with 800 mg of affinity‐labeled protein, the final yield was 39.0 μg of 33,000 MW affinity‐labeled protein. Based on an estimate of 53 mg receptor per 800 mg membrane protein, this represents an overall yield of greater than 70%.Peptide mapping was done by digesting 20 μg of the receptor protein with bovine trypsin. The proteolytic fragments were separated by reverse‐phase high‐performance liquid chromatography, and the amino acid content of 13 distinct peptides was determined. With this procedure, sufficient receptor can now be purified so that partial amino acid sequences can be obtained for further structural studies.
Rat and mouse identifier sequences are preferentially but not exclusively located in cortical neuronal genes expressed postnatally
Authors: Brown I. R. , Danielson P. , Rush S. , Godbout M. , Sutcliffe J. G. 
Published: January 2005

AbstractA genetic element called the identifier (ID) sequence, highly repeated in the rat genome, has previously been reported to be located in the introns of some genes transcribed in the adult rat brain by RNA polymerase II (Pol II). We show that nuclear RNA isolated from neurons of cerebral hemispheres (cortex) of 14‐day old rats is enrlched more than 10‐fold in ID sequences compared to nuclear RNA from liver, kidney, cerebellum, or cortical glia. The developmental onset of the difference is during the first 2 weeks after birth. Mouse cortical neuronal nuclear RNA is similarly enriched in an element related but not identical to the rat ID element, and the enrichment also has postnatal onset. The enriched appearnce of ID sequences in transcripts whose expression is increased postnatally in cortical neurons correlates developmentally and spatially with the transcription of ID elements by RNA polymerase III (Pol III) and with a change in chromatin structure.
Microsequencing of dopamine beta‐monoozygenase
Authors: McCafferty B. , Angeletti R. H. 
Published: January 2005

AbstractTryptic peptides and cyanogen bromide fragments of dopamine beta‐monooxygenase (DBH) were prepared and separated on C‐8 reverse phase columns by high pressure liquid chromatography. Absorbance profiles at both 220 nm and 280 nm were monitored so that peptides with aromatic residues could be isolated. These peptides were subjected to automated Edman degradation with a gas phase microsequencer.