scholarly journals Glutamine synthetase localization in cortisol-induced chick embryo retinas.

1980 ◽  
Vol 84 (3) ◽  
pp. 803-807 ◽  
Author(s):  
M D Norenberg ◽  
K Dutt ◽  
L Reif-Lehrer
Keyword(s):  
Enzyme Activity ◽  
Glutamine Synthetase ◽  
In Ovo ◽  
Immunohistochemical Technique ◽  
Cell Localization ◽  
Chick Retina ◽  
Age Dependent ◽  
Induced Changes ◽  
First Time

We report here for the first time, in chick retina, Muller cell localization of glutamine synthetase (GS) activity by an immunohistochemical technique, in agreement with previous reports of glial localization of this enzyme in rat brain and retina. Age-dependent changes in the endogenous enzyme activity as well as cortisol-induced changes in GS activity, both in ovo and in vitro, measured biochemically, reflect the changes observed by staining.

Steroid control of the normal development of glutamine synthetase in the embryonic chick retina

Development ◽  
1970 ◽  
Vol 23 (3) ◽  
pp. 729-737
Author(s):  
R. Piddington
Keyword(s):  
Glutamine Synthetase ◽  
Normal Development ◽  
Normal Growth ◽  
Embryonic Chick ◽  
Normal Pattern ◽  
Organ Cultures ◽  
In Ovo ◽  
Chick Retina ◽  
Study Case

Glutamine synthetase (GS) activity in the neural retina of the chick embryo is inducible with corticosteroids (Moscona & Piddington, 1966; Piddington, 1967; Moscona, Saenz & Moscona, 1967; Moscona, Moscona & Saenz, 1968; Alescio & Moscona, 1969). Striking increases in retinal GS activity can be elicited with hydrocortisone in ovo days in advance of the normal rapid rise of this enzyme (Piddington & Moscona, 1967). Rapid increases in GS activity can also be induced precociously with corticosteroids in organ cultures of young retina (Piddington & Moscona, 1967; Reif-Lehrer & Amos, 1968). The natural steroids most effective in stimulating retinal GS activities in vitro are the 11ß-hydroxyl steroids hydrocortisone, corticosterone and aldosterone (Moscona & Piddington, 1967; Reif-Lehrer, 1968). The effectiveness of corticosteroids in promoting premature changes in retinal GS suggests that the steroidogenic activity of the intact adrenals might control the normal pattern of GS development in the retina. A previous study (Case, 1952) indicates that the normal growth and maturation of the chick adrenal becomes dependent on endogenous corticotropin after the 15th day of embryonic development.

scholarly journals Regioselectivity of glucosylation of caffeic acid by a UDP-glucose:glucosyltransferase is maintained in planta1

2003 ◽  
Vol 373 (3) ◽  
pp. 987-992 ◽  
Author(s):  
Eng-Kiat LIM ◽  
Gillian S. HIGGINS ◽  
Yi LI ◽  
Dianna J. BOWLES
Keyword(s):  
Enzyme Activity ◽  
Caffeic Acid ◽  
Northern Blot Analysis ◽  
Transgenic Arabidopsis ◽  
Structural Features ◽  
Cauliflower Mosaic Virus ◽  
Leaf Extracts ◽  
Transgenic Lines ◽  
First Time

Caffeic acid is a phenylpropanoid playing an important role in the pathways leading to lignin synthesis and the production of a wide variety of secondary metabolites. The compound is also an antioxidant and has potential utility as a general protectant against free radicals. Three glucosylated forms of caffeic acid are known to exist: the 3-O- and 4-O-glucosides and the glucose ester. This study describes for the first time a glucosyltransferase [UDP-glucose:glucosyltransferase (UGT)] that is specific for the 3-hydroxyl, and not the 4-hydroxyl, position of caffeic acid. The UGT sequence of Arabidopsis, UGT71C1, has been expressed as a recombinant fusion protein in Escherichia coli, purified and assayed against a range of substrates in vitro. The assay confirmed that caffeic acid as the preferred substrate when compared with other hydroxycinnamates, although UGT71C1 also exhibited substantial activity towards flavonoid substrates, known to have structural features that can be recognized by many different UGTs. The expression of UGT71C1 in transgenic Arabidopsis was driven by the constitutive cauliflower mosaic virus 35 S (CaMV35S) promoter. Nine independent transgenic lines were taken to homozygosity and characterized by Northern-blot analysis, assay of enzyme activity in leaf extracts and HPLC analysis of the glucosides. The level of expression of UGT71C1 was enhanced considerably in several lines, leading to a higher level of the corresponding enzyme activity and a higher level of caffeoyl-3-O-glucoside. The data are discussed in the context of the utility of UGTs for natural product biotransformations.

Changes in Gene Expression during Drying in a Desiccation-Tolerant Grass Sporobolus stapfianus and a Desiccation-Sensitive Grass Sporobolus pyramidalis

1997 ◽  
Vol 24 (5) ◽  
pp. 617 ◽  
Author(s):  
D.F. Gaff ◽  
D. Bartels ◽  
J.L. Gaff
Keyword(s):  
Gene Expression ◽  
Desiccation Tolerance ◽  
Transcriptional Level ◽  
Novel Proteins ◽  
Sporobolus Stapfianus ◽  
Induced Changes ◽  
First Time ◽  
Dimensional Electrophoresis ◽  
Water Contents

For the first time in the grasses, a desiccation-tolerant species (Sporobolus stapfianus) was examined for evidence of drought-induced changes in gene transcription. Desiccation tolerance (the ability of this species to recover from a water potential of –540 MPa) is induced in the resurrection grass during the drying process itself. Specific mRNA was compared in extracts of air-dry, drying and fully hydrated leaves by comparisons of the encoded proteins translated in vitro and partitioned by 2- dimensional electrophoresis. Forty-one genes, that were not expressed in hydrated leaves, were transcribed during drying, whereas only 25 novel polypeptides (translated in vitro) were detected; this suggests that gene expression was controlled mainly at the transcriptional level, but possibly also at the translational level. Leaves of S. stapfianus become desiccation tolerant as they dry on intact plants with mechanically undisturbed roots, whereas leaves on plants whose roots have been disturbed die during drying. Complements of mRNA from live S. stapfianus leaves changed markedly from full hydration to 70% RWC and to air-dryness; they also differed markedly from drought-sensitive leaves (on plants with disturbed roots) at 70% RWC and dead air-dry S. stapfianus leaves and from leaves of the desiccation sensitive grass S. pyramidalis at the same water contents. Drought-induced injury could not be attributed to low abundance of mRNA in either species. Five criteria which might be involved in desiccation tolerance were applied to specific in vitro proteins of S. stapfianus; 12 novel proteins correlated with desiccation tolerance in a least four of the five criteria.

scholarly journals PTP1B INHIBITORS FROM ISODON TERNIFOLIUS COLLECTED IN VIETNAM

2020 ◽  
Vol 58 (5) ◽  
pp. 533
Author(s):  
Nguyen Phi-Hung
Keyword(s):  
Enzyme Activity ◽  
Inhibitory Activity ◽  
In Vitro Assay ◽  
Vitro Assay ◽  
Chemical Structures ◽  
Whole Plant ◽  
Ic50 Values ◽  
Ptp1b Inhibitors ◽  
First Time

From the whole plant of Isodon ternifolius collected in Vietnam, four triterpens including ursaldehyde (1), ursolic acid (2), b-sitosterol (3) and b-sitosteryl ferulate (4) were purified. Their chemical structures were determined by interpretation of NMR and MS data and comparison with the literatures. Compounds 1-4 were evaluated for their inhibitory activity against PTP1B enzyme activity using in vitro assay. Compounds 1 and 2 displayed potential activities with IC50 values of 16.92 ± 0.12 and 3.42 ± 0.45 μM, respectively. This is the first time that compounds 1 and 4 have been isolated from the Isodon genus and I. ternifolius has been evaluated for the PTP1B inhibitory activity.

Systemic Effects of ADP-induced Platelet Aggregation and Their Modification by Aspirin and by Pyridinolcarbamate

1973 ◽  
Vol 30 (01) ◽  
pp. 178-190 ◽  
Author(s):  
Itsuro Kobayashi ◽  
Paul Didisheim
Keyword(s):  
Platelet Aggregation ◽  
Venous Pressure ◽  
Systemic Effects ◽  
Central Venous ◽  
Platelet Aggregates ◽  
Induced Changes ◽  
Second Wave ◽  
Carotid Arterial ◽  
Arterial Po2

SummaryADP, AMP, or ATP was injected rapidly intravenously in rats. ADP injection resulted in the f olio wing transient changes: a drop in platelet count, a rise in central venous pressure, a fall in carotid arterial PO2, bradycardia, arrhythmia, flutter-fibrillation, and arterial hypotension. AMP and ATP produced some of these same effects; but except for hypotension, their frequency and severity Avere much less than those following ADP.Prior intravenous administration of acetylsalicylic acid or pyridinolcarbamate, two inhibitors of the second wave of ADP-induced platelet aggregation in vitro, significantly reduced the frequency and severity of all the above ADP-induced changes except hypotension. These observations suggest that many of the changes (except hypotension) observed to follow ADP injection are produced by platelet aggregates which lodge transiently in various microcirculatory beds then rapidly disaggregate and recirculate.

Somatic Embryogenesis and In vitro Plant Regeneration in Vigna trilobata (L.) Verd. - A Potential Pasture Legume

1970 ◽  
Vol 19 (1) ◽  
pp. 89-99
Author(s):  
K. Choudhary ◽  
M. Singh ◽  
M. S. Rathore ◽  
N. S. Shekhawat
Keyword(s):  
Somatic Embryogenesis ◽  
Growth Regulators ◽  
Somatic Embryos ◽  
Basal Medium ◽  
Long Term Study ◽  
Continuous Application ◽  
First Time ◽  
Pasture Legume

This long term study demonstrates for the first time that it is possible to propagate embryogenic Vigna trilobata and to subsequently initiate the differentiation of embryos into complete plantlets. Initiation of callus was possible on 2,4-D. Somatic embryos differentiated on modified MS basal nutrient medium with 1.0 mg/l  of 2,4-D and 0.5 mg/l  of Kn. Sustained cell division resulted in globular and heart shape stages of somatic embryos. Transfer of embryos on to a fresh modified MS basal medium with 0.5 mg/l of Kn and 0.5 mg/l of GA3 helped them to attain maturation and germination. However, the propagation of cells, as well as the differentiation of embryos, were inhibited by a continuous application of these growth regulators. For this reason, a long period on medium lacking these growth regulators was necessary before the differentiation of embryos occurred again. The consequences for improving the propagation of embryogenic cultures in Vigna species are discussed. Key words: Pasture  legume, Vigna trilobata, Globular, Heart shape, somatic embryogenesis D.O.I. 10.3329/ptcb.v19i1.4990 Plant Tissue Cult. & Biotech. 19(1): 89-99, 2009 (June)

Dwindling status of Epimedium Elatum (Morren & Decne) and its geographical distribution in Kashmir Himalaya, India

2018 ◽  
pp. 47-52
Keyword(s):  
Medicinal Plant ◽  
Biological Activities ◽  
Conservation Status ◽  
Natural Populations ◽  
Culture Techniques ◽  
Kashmir Himalayas ◽  
Near Future ◽  
First Time ◽  
Tissue Culture Techniques

Epimedium elatum (Morren & Decne) of family Berberidaceace is a rare perennial medicinal plant, endemic to high altitude forests of Northwestern Himalayas in India. Ethnobotanically, it has been used as an ingredient for treatment of bone-joint disorders, impotence and kidney disorders in Kashmir Himalayas. Phytochemically, it is rich in Epimedin ABC and Icariin; all of these have been demonstrated to possess remarkable biological activities like PDE-5 inhibition (treatment of erectile dysfunction), anticancer, antiosteoporosis antioxidant and antiviral properties. The present investigation reports its traditional usage, comprehensive distribution and conservation status from twenty ecogeographical regions in Kashmir Himalayas, India. The species was reported from Gurez valley for the first time. Numerous threats like excessive grazing, deforestration, habitat fragmentation, tourism encroachment, landslides and excessive exploitation have decreased its natural populations in most of the surveyed habitats. Consequently, its existence may become threatened in near future if timely conservation steps are not taken immediately by concerned stakeholders involved in medicinal plant research. Moreover, use of plant tissue culture techniques is recommended for development of its in vitro propagation protocols. Therefore, introduction of this medicinal plant in botanical gardens, protected sites and development of monitoring programmes are needed for its immediate conservation in Northwestern Himalayas, India.

Structure-Reactivity Relationships on Substrates and Inhibitors of the Lysine Deacylase Sirtuin 2 from Schistosoma Mansoni (SmSirt2)

2019 ◽  
Author(s):  
Daria Monaldi ◽  
Dante Rotili ◽  
Julien Lancelot ◽  
Martin Marek ◽  
Nathalie Wössner ◽  
...  
Keyword(s):  
Schistosoma Mansoni ◽  
Human Cancer ◽  
Egg Laying ◽  
Human Cancer Cells ◽  
Parasite Survival ◽  
Survival And Reproduction ◽  
Emergence Of Resistance ◽  
First Time ◽  
Parasitic Life Cycle

The only drug for treatment of Schistosomiasis is Praziquantel, and the possible emergence of resistance makes research on novel therapeutic agents necessary. Targeting of Schistosoma mansoni epigenetic enzymes, which regulate the parasitic life cycle, emerged as promising approach. Due to the strong effects of human Sirtuin inhibitors on parasite survival and reproduction, Schistosoma sirtuins were postulated as therapeutic targets. In vitro testing of synthetic substrates of S. mansoni Sirtuin 2 (SmSirt2) and kinetic experiments on a myristoylated peptide demonstrated lysine long chain deacylation as an intrinsic SmSirt2 activity for the first time. Focused in vitro screening of the GSK Kinetobox library and structure-activity relationships (SAR) of identified hits, led to the first SmSirt2 inhibitors with activity in the low micromolar range. Several SmSirt2 inhibitors showed potency against both larval schistosomes (viability) and adult worms (pairing, egg laying) in culture without general toxicity to human cancer cells.<br>

α-Glucosidase Inhibition and Docking Studies of 5-Deoxyflavonols and Dihydroflavonols Isolated from Abutilon pakistanicum

2019 ◽  
Vol 23 (17) ◽  
pp. 1857-1866
Author(s):  
Munawar Hussain ◽  
Zaheer Ahmed ◽  
Shamsun N. Khan ◽  
Syed A. A. Shah ◽  
Rizwana Razi ◽  
...  
Keyword(s):  
Methanolic Extract ◽  
Docking Studies ◽  
Hydroxyl Group ◽  
Coumaric Acid ◽  
In Vitro Activity ◽  
Aerial Parts ◽  
First Time ◽  
Acid Esters ◽  
Phenol Moiety

Three new 5-deoxyflavonoid and dihydroflavonoids 2, 3 and 4 have been isolated from the methanolic extract of Abutioln pakistanicum aerial parts, for which structures were elucidated explicitly by extensive MS- and NMR-experiments. In addition to these, 3,7,4′-trihydroxy-3′-methoxy flavonol (1) is reported for the first time from Abutioln pakistanicum. Compound 2 and 4 are p-coumaric acid esters while compounds 2–4 exhibited α-glucosidase inhibitory activity. Docking studies indicated that the ability of flavonoids 2, 3 and 4 to form multiple hydrogen bonds with catalytically important residues is decisive hence is responsible for the inhibition activity. The docking results signified the observed in-vitro activity quite well which is in accordance with previously obtained conclusion that phenol moiety and hydroxyl group are critical for the inhibition of α-glucosidase enzyme.

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