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OS1.7 Genomic attributes of tumor evolution and treatment response in diffuse glioma. Neuro Oncol 2018. [DOI: 10.1093/neuonc/noy139.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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A review of recent non-target toxicity testing of vertebrate pesticides: establishing generic guidelines. NEW ZEALAND JOURNAL OF ZOOLOGY 2013. [DOI: 10.1080/03014223.2013.772067] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Abstract
Fumaric acid esters (FAE) have been used in the treatment of psoriasis for many years. In general, they are regarded as relatively safe compared with other antipsoriatic systemic treatments, with the most notable adverse effects being gastrointestinal upset, lymphopenia and transient flushing. Renal toxicity has only rarely been reported, and was not found in two independent prospective trials nor in a large retrospective evaluation of almost 1000 patients treated for a median of 44 months. We report three patients developing reversible proteinuria during FAE treatment. One of these displayed the same pattern upon repeated drug administration, thereby clearly indicating FAE treatment to be the causal trigger. The presented cases highlight proteinuria as a clinical concern in FAE treatment. Furthermore, as the novel FAE agent dimethylfumaric (DMF) ester (contained in BG00012/Panaclar) has previously been shown to be effective in psoriasis in a phase III trial and not shown renal toxicity in a large trial for multiple sclerosis, the current report suggests that market introduction of DMF for psoriasis should be pursued.
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Killed Mycobacterium vaccae suspension in children with moderate-to-severe atopic dermatitis: a randomized, double-blind, placebo-controlled trial. Clin Exp Allergy 2006; 36:1115-21. [PMID: 16961710 DOI: 10.1111/j.1365-2222.2006.02558.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
BACKGROUND The hygiene hypothesis is often proposed to explain the high prevalence of atopy in the western world. Dysregulation of the immune system may result from inadequate exposure to micro-organisms such as mycobacteria. A small trial suggested that a killed extract of Mycobacterium vaccae ameliorates atopic dermatitis (AD). OBJECTIVES To confirm in a large clinical trial whether killed M. vaccae ameliorates AD in 5-16-year-old children. METHODS This was a randomized, placebo-controlled, double-blind, multi-centre study of the effect of intradermal injection of killed M. vaccae (0.1 or 1 mg) on patients, aged 5-16, with moderate-to-severe AD. Patients were followed up for 24 weeks. The primary end point was the change in severity of AD at 12 weeks, assessed using the six area, six-sign, atopic dermatitis (SASSAD) score. Secondary end points included changes in disease extent, patient's global assessment and children's dermatology life quality index. RESULTS There were 166 patients randomized. The mean SASSAD score fell to a similar degree at week 12 in all treatment arms: from 33 to 24, (26%) in the high-dose group, from 30 to 23 (25%) in the low-dose group and from 36 to 27 (24%) in the placebo group (P>0.05). Secondary end points followed the same trend. Adverse events were generally those expected to occur in this population. Injection site reactions occurred in 32 patients at week 4. CONCLUSIONS M. vaccae was no more effective than the placebo in ameliorating the severity of AD.
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Abstract
The ability to integrate education, practice and research initiatives is well documented and the nursing literature presents several collaborative models that have emerged between educational institutions and service agencies to achieve this aim. However, a collaborative partnership agreement does more than integrate these initiatives; it is a vehicle by which the theory-clinical practice gap is bridged and best practice outcomes are achieved. This paper outlines an innovative collaborative partnership agreement between Fremantle Hospital and Health Service and Curtin University of Technology in Perth, Western Australia. The partnership engages academics in the clinical setting in two formalised collaborative appointments. This partnership not only enhances communication between educational and health services, but fosters the development of nursing research and knowledge. The process of the collaborative partnership agreement involved the development of a Practice-Research Model (PRM) of collaboration. This model encourages a close working relationship between registered nurses and academics, and has also facilitated strong links at the health service with the Nursing Research and Evaluation Unit, medical staff and other allied health professionals. Links have also been established with other health services and agencies in the metropolitan area. The key concepts exemplified in the application of the model include practice-driven research development, collegial partnership, collaborative ownership and best practice. Many specific outcomes have been achieved through implementation of the model, but overall the partnership between registered nurses and academics in the pursuit of research to support clinical practice has been the highlight. This has resulted in changes and innovations in current nursing practice and, importantly, dissemination of best practice outcomes.
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Abstract
In this study, we reviewed pharmacoeconomic guidelines from the United Kingdom, Spain, Italy, Australia, Canada, and the United States to determine areas of emerging standardization. We examined the published literature, publication guidelines of major health journals, and published and unpublished recommendations from various task forces and conferences on related topics. The review revealed several general principles for which there was consensus across guidelines. These common features included the importance of using and reporting transparent methods so that readers can easily understand what calculations are being performed on which data elements, minimizing bias, and providing justification for the methods and assumptions used. Differences were detected across guidelines on the following topics: type of pharmacoeconomic assessment, perspective, comparators and data sources, data analysis, cost analysis, future cost analysis, outcomes assessment, modeling, time horizon, discounting, disclosure, and generalizability. Evolution of economic guidelines hinges on whether the primary goal is to increase the consistency or increase the validity of economic assessments. Some balance between these two objectives is desirable.
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Abstract
Cathepsin L is a major lysosomal cysteine protease produced by mouse placenta and fibroblasts. This study characterizes a novel cathepsin L-related mRNA expressed in rat placenta. Immunological and nucleotide screening of a rat placenta library identified six positive clones, the largest, pCLRP-9, being 924 base pairs in length. The combined sequences of all the clones contain an open reading frame of 711 nucleotides, a termination codon, a polyadenylation site, and 197 nucleotides of 3' untranslated region, but lack the 5' translation initiation codon. The pCLRP nucleotide sequence showed 60-64% identity to those of mouse, rat, and human cathepsin L. The deduced amino acid sequence of pCLRP codes for 237 amino acids, which align with the carboxy-terminal sequence of cathepsin L and has the active site residues characteristic of the cysteine protease family. Northern blot analysis showed hybridization of pCLRP with a major mRNA transcript of 1.3 kilobases expressed in placenta, but not kidney or liver. In contrast, a cDNA for mouse pro-cathepsin L hybridized with a transcript of 1.7 kilobases expressed in rat kidney, as well as placenta. During late gestation, steady-state levels of rat placental pCLRP mRNA were highest on day 18, whereas those of mouse procathepsin L were greatest on day 20 of gestation. Antiserum to mouse cathepsin L cross-reacted with four proteins of molecular weights 36,000 to 42,000 in rat placental culture medium, of which two were absent in the kidney. These data indicate that rat placenta expresses several species of cathepsin L-type proteins, which may be involved in placental function and nutrient supply.
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Abstract
This study was conducted to identify proteins synthesized and secreted de novo by the guinea pig uterus. Uterine samples were obtained from cycling, late-pregnant as well as ovariectomized and steroid-treated guinea pigs and cultured with either L-[3H]leucine or L-[35S]methionine. Two-dimensional SDS-PAGE of culture medium followed by fluorography was used to determine proteins synthesized and secreted de novo during a 24-h incubation period. Two complexes of estradiol-stimulated proteins (ESP) were detected. Each complex was composed of 5-7 unique proteins with slightly different isoelectric points. The higher molecular-weight complex had a molecular weight of 65,000-60,000 and an isoelectric point range of 5.2-6.1. The lower molecular-weight complex had a molecular weight of 60,000-55,000 and a similar range of isoelectric points. The two complexes of ESP were not observed in medium of explants from animals that received placebos, were late-pregnant, or were treated with progesterone only. Progesterone administered in combination with estradiol enhanced production of both complexes of ESP to similar degrees. Neither complex of ESP was secreted by the explant culture in the presence of tunicamycin, suggesting that the proteins are glycosylated. These findings demonstrate that the uterus of the guinea pig produces two unique complexes of proteins in response to estradiol stimulation, and all results are consistent with the hypothesis that ESP are contained in the carbohydrate-rich secretory granules of endometrial gland cells.
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Developmental expression of rat insulin-like growth factor binding protein-2 by astrocytic glial cells in culture. Endocrinology 1991; 129:1066-74. [PMID: 1713158 DOI: 10.1210/endo-129-2-1066] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Brain astrocytes were established in primary culture from postnatal and adult rats to characterize the developmental expression of secreted proteins. Astrocytes cultured from 21-day rat brain, but not 1-day rat brain, secreted a distinct group of proteins with Mr of 35,000 as determined by analysis of [35S]methionine-labeled proteins using two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis. N-terminal amino acid sequence analysis of this protein group showed 100% identity to rat insulin-like growth factor binding protein-2 (rIGFBP-2), the BRL-3A IGFBP purified from a fetal rat liver cell line. An antiserum was generated against this astrocyte 35,000 Mr protein, and immunoblot analysis revealed a dramatic increase in rIGFBP-2 secretion in astrocytes cultured from 14-day, 21-day, and adult rat brain compared to astrocytes from 1-day and 7-day rat brain. Similar analysis of neonatal rat brain neurons in culture failed to show immunoreactive rIGFBP-2 in cell lysates or secreted protein. Ligand Western blot analysis demonstrated [125I]IGF-II binding to a single protein band which comigrated with a prominant rIGFBP-2 immunoreactive species in nonreduced conditioned medium from 21-day astrocytes. In comparison [125I]IGF-II binding proteins were detected only at low levels in medium from astrocytes cultured from 1-day rat brain and were undetectable in neuron-conditioned media. Northern blot analysis using a rIGFBP-2 complementary DNA revealed 5-fold greater messenger RNA levels in astrocytes from 21-day rat brain compared with astrocytes from 1-day brain, whereas neonate neurons showed no transcripts. Thus, rIGFBP-2 exhibits a pattern of developmental and cell-specific expression in cultured rat brain cells.
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Abstract
For the first time, we demonstrate here the ability of human relaxin to block cell division. During the induction of differentiation of 3T3-L1 fibroblasts to adipocytes, the cells typically undergo two rounds of cell division followed by accumulation of lipid droplets and expression of insulin-stimulated glucose transport as the cells attain the adipocyte phenotype. Human relaxin added during induction had no effect on the development of the adipocyte phenotype or insulin-stimulated glucose transport. However, it blocked cell division at a half-maximal concentration of 1.25 nM, well within physiological range. This could be reversed by the addition of antibodies specific for human relaxin. Thus relaxin joins a select number of hormones with growth inhibitory properties such as transforming growth factor-beta (TGF beta) and mammastatin. Potentially, this is an important but until now unidentified function of relaxin. Unlike other inhibitory polypeptides, like TGF beta, relaxin does not prevent differentiation but rather uncouples it from cell division.
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Abstract
Mid-to-late gestation rat placenta synthesizes a number of proteins related to prolactin, including rat placental lactogen II (rPL-II), rat prolactin-like protein A (rPLP-A) and rat prolactin-like protein B (rPLP-B). This study identifies a new family of proteins synthesized and secreted by gestation day 15 placental explants which exhibit amino acid homology to growth hormone precursors from several species. Placental explant medium was fractionated by ammonium sulfate precipitation and analyzed by two-dimensional SDS-polyacrylamide gel electrophoresis to isolate four distinct proteins with Mr values of 28,000, 23,000, 25,000 and 30,000 and pI values of 5.7, 5.7, 5.4 and 5.3, respectively. These proteins represent a major fraction of secretory proteins with Mr in the 20,000 to 30,000 range. Immunoblot analysis showed that none of the four proteins crossreacted with antipeptide antisera against rPL-II, rPLP-A, or rPLP-B. These proteins were electrophoretically transferred from two-dimensional SDS-polyacrylamide gels onto an Immobilon PVDF membrane and N-terminal amino acid microsequencing carried out with a gas phase sequencer. N-terminal sequences of 45, 37, 37 and 32 amino acid residues were identified for proteins 1, 2, 3 and 4, respectively. The four proteins exhibit 76% to 97% homology. Computer analysis further revealed a 28% identity in a 32 amino acid overlap which begins at residue 14 of the 28,000 Mr protein (protein 1) and at residue 31 of growth hormone precursors of rat, mouse and human. The 32 amino acid overlap is 78% homologous if conservative amino acid replacements are included.
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Abstract
Mid- to late-gestation rat placenta expresses three PRL-related mRNAs, rat placental lactogen-II (rPL-II), rat PRL-like protein-A (rPLP-A), and rat PRL-like protein-B (rPLP-B). The protein product of rPL-II mRNA has been characterized, and the protein products of the rPLP-A mRNA were recently identified. The mol wt of a nonsecreted nonglycosylated rPLP-B protein would be 27,145 based on the mRNA sequence. The present study is the first to report the identification of the rPLP-B protein. Antiserum was generated against a chemically synthesized oligopeptide inferred from a specific region of the rPLP-B cDNA. Three or four distinct proteins synthesized and secreted by rat basal zone explants (day 15 gestation) showed cross-reactivity with the rPLP-B antiserum. The relative mol wt of these immunoreactive proteins is approximately 30,000, with a pI varying from 6.1-6.6. De novo synthesized rPLP-B proteins were not secreted by the explant tissue in the presence of tunicamycin, suggesting that the proteins are glycosylated. These data are consistent with the presence of one potential N-glycosylation site derived from the rPLP-B mRNA sequence. The rPLP-B antiserum showed no cross-reactivity with proteins identified using antisera against rPLP-A, rPL-II, or human pregnancy-specific beta 1-glycoprotein. Immunocytochemical studies were carried out using paraffin sections from placentas of day 14 and 17 pregnant rats which were treated with anti-rPLP-B, followed by avidin-biotin-peroxidase complex. These experiments show perinuclear staining, which was localized in basophilic cytotrophoblast cells, confirming previous in situ mRNA hybridization studies. Although no physiological role has been established for rPLP-B, the synthesis and secretion of this protein by cells in contact only with maternal circulation suggest a hormonal role.
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Benzo(a)pyrene inhibits epidermal growth factor binding and receptor autophosphorylation in human placental cell cultures. Mol Pharmacol 1990; 37:137-43. [PMID: 2154666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Studies investigated the effects of benzo(a)pyrene (BP) treatment on epidermal growth factor (EGF) receptor binding and kinase activity in human placental cell cultures. Specific binding of 125I-EGF to cells from early gestation placentae was significantly decreased by 37 and 60% following exposure to 1 and 10 microM BP, respectively, for 24 hr. In contrast, cells cultured from term placentae showed no inhibitory effect of either concentration of BP. Specific binding of 125I-labeled insulin and insulin-like growth factors-I and -II to early gestation cells was decreased only 15-18% at 10 microM BP, which indicates that loss of membrane receptors appears to be selective for EGF. Scatchard analysis of early gestation cells revealed that BP was associated with a dose-dependent loss in the number of high affinity EGF binding sites. Evidence from cross-linking and autophosphorylation experiments confirmed that the Mr 170,000 binding protein was decreased in a dose-dependent manner following BP treatment. In comparison, term placental cells exhibit a 26% loss of EGF receptor autophosphorylation without alteration in binding following exposure to 10 microM BP. Thus, early gestation cells exhibit a BP-related down-regulation of EGF receptors, whereas term placental cells show receptor desensitization. No adverse effect of BP treatment was observed on the incorporation of [35S] methionine into proteins secreted by early gestation cells. Further experiments compared the effects of BP with the related poly-cyclic compounds beta-naphthoflavone, alpha-naphthoflavone, and 3-methylcholanthrene. In early gestation cells, EGF binding and receptor autophosphorylation were measurably decreased at 10 microM concentrations of these polycyclic compounds, but to a lesser extent than observed with BP. In term placental cells, however, EGF binding was unchanged or increased, whereas receptor autophosphorylation was decreased 10-26%. Thus, exposure of term placental cells to these polycyclic compounds leads to a dissociation between EGF binding and receptor protein kinase activity. Finally, aryl hydrocarbon hydroxylase activity was induced 20- to 200-fold in early placental cells exposed to BP, beta-naphthoflavone, and 3-methylcholanthrene. In summary, the direct effects of BP and related compounds observed on placental EGF receptors may indicate altered function of EGF in the regulation of cell growth and differentiation in the human placenta.
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Pregnancy-specific beta 1-glycoprotein messenger ribonucleic acid and immunoreactive protein in the rat testis. Endocrinology 1990; 126:292-8. [PMID: 2403519 DOI: 10.1210/endo-126-1-292] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Human pregnancy-specific beta 1-glycoprotein (PS beta G) is synthesized in large quantities by syncytiotrophoblasts of the placenta. Recent studies using a partial cDNA of PS beta G isolated from human term placenta detected the presence of mRNA highly homologous to placental PS beta G in a number of extraplacental tissues, including human and rat testis. The present study determined in the rat that the amount of PS beta G mRNA based on percentage of total tissue RNA was greatest in the testis of mature rats, followed by senescent and prepubertal rats. In experiments using rats with testicular feminization syndrome (Tfm) which exhibit end-organ insensitivity to androgen stimulation, slot blot analysis of testicular RNA showed reduced levels of PS beta G mRNA in Tfm rats compared to normal rats. Northern blot analysis of rat testicular RNA probed with a human placental PS beta G cDNA demonstrated the presence of a single mRNA species of 1.65 kilobases. Subsequent studies investigated whether proteins immunologically similar to PS beta G were present in the testes from normal and Tfm rats. The rat testes were perfused with fixative, and sections from paraffin-embedded tissues were treated with rabbit anti-human PS beta G, followed by the avidin-biotin-peroxidase complex. Testes from the normal rat showed intense immunostaining in late spermatids (steps 16, 17, 18, and 19 of spermiogenesis), residual bodies, as well as cytoplasm of Leydig cells. Spermatozoa within the epididymis also demonstrated intense immunolabeling. Paraffin sections of the testes from the Tfm rat showed light diffuse cytoplasmic immunostaining in cells of the seminiferous tubules. Since spermiogenesis does not proceed normally, and no spermatids were seen, it was not possible to accurately stage the seminiferous tubules of the Tfm rat. The Leydig cells of the Tfm testes stained intensely, however, as was observed in the testes of the normal rat. These data suggest that the rat may provide an animal model for the investigation of the biological function and regulation of PS beta G in the testis.
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Gestational profiles of the immunocytochemical localization of rat prolactin-like protein-B, rat placental lactogen II and pregnancy-specific β1-glycoprotein in rat placenta. Placenta 1989. [DOI: 10.1016/0143-4004(89)90186-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Identification of proteins immunochemically related to human pregnancy-specific beta 1-glycoprotein in the rat placenta. Endocrinology 1989; 125:287-94. [PMID: 2786803 DOI: 10.1210/endo-125-1-287] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Human pregnancy-specific beta 1-glycoprotein (hPS beta G) consists of a set of glycoproteins present in placenta and maternal serum. This study characterized proteins in rat placenta that show immunological cross-reactivity with antisera to hPS beta G. Immunocytochemical studies using two independent preparations of anti-hPS beta G showed intense specific staining within basophilic cytotrophoblast cells of the basal zone of the gestation day 15 rat placenta. In contrast, basophilic cytotrophoblasts located in the labyrinth did not stain. Subsequent experiments used gel electrophoresis and immunoblot analysis to compare PS beta G in human placenta and serum with immunoreactive proteins in rat placenta and serum. A set of two or three proteins was detected in human villous tissue and pregnancy serum with apparent mol wt (Mr) ranging from 54,000-76,000. In contrast rat placenta showed a major immunoreactive protein with 120,000 Mr, while rat serum contained bands of 48,000 64,000 and 69,000 Mr. Explant cultures of rat basal zone tissue secreted two [35S]methionine-labeled proteins that were immunoreactive, a major 120,000 Mr species and a minor 76,000 Mr form, with pI values of 4.6-5.5; tunicamycin inhibited the secretion of both species. Thus, a 120,000 Mr glycoprotein appears to be the major tissue and secreted form of rat PS beta G analog in day 15 placenta. Finally, the cytochemical localization of PS beta G-like proteins in rat placenta showed a progressive gestational shift from giant trophoblast cells in the parietal yolk sac placenta on day 12 to the basal zone cytotrophoblast cells by day 15. Data indicate that the pregnant rat may provide an animal model for investigation of the biological function of PS beta G during late gestation.
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Characterization of epidermal growth factor receptors in astrocytic glial and neuronal cells in primary culture. Endocrinology 1989; 124:240-7. [PMID: 2783308 DOI: 10.1210/endo-124-1-240] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Studies characterized the structure and function of epidermal growth factor (EGF) receptors in astrocytic glial cells and neuronal cells in primary culture from neonatal rat brain. [125I]EGF binding to membranes prepared from glial and neuronal cultures was specific and dependent on protein concentration; however, glial preparations bound 5-fold more [125I]EGF per mg protein. Unlabeled EGF competed for binding to both glial and neuronal membranes with an IC50 of 5 nM, whereas insulin, insulin-like growth factor I, and nerve growth factor failed to compete. Scatchard plot analysis of binding data for glial cells yielded a curvilinear plot with dissociation constants of 7.12 nM for high affinity and 6.2 microM for low affinity sites. The higher level of binding in glial compared to neuronal membranes reflected a greater number of binding sites rather than differences in receptor affinity. In glial membranes, [125I]EGF covalently cross-linked to one major protein with a mol wt of 170,000, and EGF stimulated the phosphorylation of a 170,000 protein which was half-maximal at 20 nM. In contrast, neither covalent cross-linking nor receptor autophosphorylation could be detected in neuronal membranes. Culture of glial cells in the presence of EGF stimulated [35S]methionine incorporation into both cellular and secreted proteins, whereas no effect of EGF was observed in neuronal cultures. The addition of EGF to glial cultures produced a dose-dependent stimulation of [3H]thymidine incorporation as well as the multiplication of cells over a 6-day period. These observations show that functional EGF receptors in the neonatal brain are predominantly localized in glial cells.
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Effects of estradiol and progesterone on accumulation of relaxin- and carbohydrate-containing granules in endometrial gland cells of the guinea pig. THE AMERICAN JOURNAL OF ANATOMY 1987; 179:333-41. [PMID: 3661457 DOI: 10.1002/aja.1001790404] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Guinea pigs were spayed and given various regimens of injections of estradiol and progesterone. The following were monitored in each animal: pubic separation (relaxin stimulation), resorption of the vaginal membrane (estrogen priming), and the presence of PAS-positive granules and/or relaxin in endometrial gland cells (EGC). Injections of estradiol alone resulted in resorption of the vaginal membrane, accumulation of PAS-positive granules in EGC of all animals, and accumulation of relaxin in EGC of two of four animals; but they did not cause pubic separation. Progesterone injections did not result in resorption of the vaginal membrane, separation of pubes, or accumulation of PAS-positive granules; however, one of three animals demonstrated a few EGC that contained relaxin. Animals that received both estradiol and progesterone exhibited PAS-positive granules and relaxin in EGC as well as separated pubes, but did not have resorbed vaginal membranes. Upon examination with the electron microscope, EGC from animals that received estradiol alone exhibited remarkable numbers of secretory granules that contained a carbohydrate-rich material. Secretory granules were not prominent in EGC from animals that received progesterone alone. Estradiol and progesterone injections resulted in accumulation of secretory granules in EGC that contained relaxin and a carbohydrate-rich material. The observations that estradiol and progesterone induce relaxin production in EGC support the hypothesis that uterine relaxin plays an important role in pregnancy and/or parturition in the guinea pig.
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Cytochemical detection of carbohydrate and immunocytochemical detection of relaxin in the same secretory granule. J Histochem Cytochem 1987; 35:693-7. [PMID: 3553319 DOI: 10.1177/35.6.3553319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
We administered estradiol and progesterone to spayed guinea pigs, with resultant accumulation of secretory granules in endometrial gland cells. By initially employing protein A-colloidal gold immunolocalization of relaxin, followed by cytochemical staining of carbohydrate with the thiocarbohydrazide-silver proteinate method on the same section, we showed clearly that the secretory granules were composed of a central core containing relaxin and a cortex of carbohydrate-rich material. Use of normal rabbit serum rather than relaxin antiserum, and omission of periodic acid, demonstrated the specificity of the technique.
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Abstract
The production of an extracellular deaminase activity involved with the utilization of amino acids as sole sources of nitrogen is under the control of the nit-2 locus of Neurospora crassa. This locus is the sole major nitrogen regulatory locus described for N. crassa and is believed to encode a positive effector required for induction of activities involved with the utilization of alternate nitrogen sources. Production of deaminase activity requires the lifting of nitrogen metabolite repression, the presence of a functional nit-2 gene product, and specific induction by amino acids. Additional parameters of enzyme production are described.
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Abstract
The effect of the nmr-1 and ms-5 mutations, which lead to insensitivity to glutamine-mediated nitrogen metabolite repression, was examined with respect to extracellular deaminase production by Neurospora crassa. Deaminase production normally requires nitrogen limitation, but these mutations eliminated this requirement and allowed production of deaminase activity under nitrogen metabolite repressing conditions. Demonstration of normal glutamine transport by both strains eliminated the possibility that these mutations exerted their effects through repressor exclusion. We have proposed a new working model for nitrogen regulation in Neurospora based on the findings that these mutations affected a nitrogen-regulated activity in addition to those activities originally reported and that the mutations are genetically very closely linked and likely allelic.
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Abstract
A strain of Neurospora crassa defective in amino acid transport can utilize a variety of amino acids for growth when readily metabolizable nitrogen is limiting. Growth is accompanied by the production of an extracellular deaminase that converts the amino acid to its respective keto acid plus equimolar quantities of utilizable nitrogen in the ammonium ion form. Production of the deaminase is subject to ammonium repression. The relationship between the ability of an amino acid to trigger deaminase production and the presence of particular amino acid permease deficiencies is complex. Four classes of amino acids have been defined with respect to this relationship. The existence of multiple extracellular deaminases is discussed.
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