UTERINE TISSUES FROM PREGNANT GOATS PRODUCE 6-OXO-PROSTAGLANDIN F1α IN VITRO

1978 ◽  
Vol 79 (3) ◽  
pp. 401-402 ◽  
Author(s):  
M. D. MITCHELL ◽  
A. P. F. FLINT ◽  
B. R. HICKS ◽  
E. J. KINGSTON ◽  
G. D. THORBURN ◽  
...  
Keyword(s):  
Biological Systems ◽  
Aqueous Media ◽  
Late Pregnancy ◽  
University Of Oxford ◽  
Obstetrics And Gynaecology ◽  
Nuffield Department ◽  
John Radcliffe Hospital ◽  
Prostaglandin F

Nuffield Department of Obstetrics and Gynaecology, University of Oxford, John Radcliffe Hospital, Headington, Oxford, 0X3 9DU (Received 21 July 1978) It now seems likely that prostaglandins play an important role in the mechanisms of parturition in many species (Flint & Hillier, 1976; Thorburn, Challis & Robinson, 1977), including the goat (Thorburn, Nicol, Bassett, Shutt & Cox, 1972; Currie & Thorburn, 1977). This evidence has been further strengthened by the demonstration of the production of prostaglandins in vitro by uterine tissues from goats during late pregnancy (Mitchell, Flint, Robinson & Thorburn, 1978b). The recent discovery of prostacyclin (Moncada, Gryglewski, Bunting & Vane, 1976) has added a new dimension to prostaglandin research since in some biological systems it has a greater potency than other prostaglandins (Moncada et al. 1976; Omini, Moncada & Vane, 1977). Prostacyclin is highly unstable in aqueous media and degrades spontaneously to 6-oxo-prostaglandin F1α (6-oxo-PGF1α; Johnson, Morton, Kinner, Gorman,

PRODUCTION OF THROMBOXANE B2 BY INTRA-UTERINE TISSUES FROM PREGNANT GOATS IN VITRO

1978 ◽  
Vol 78 (1) ◽  
pp. 159-160 ◽  
Author(s):  
M. D. MITCHELL ◽  
A. P. F. FLINT ◽  
E. J. KINGSTON ◽  
G. D. THORBURN ◽  
J. S. ROBINSON
Keyword(s):  
Thromboxane B2 ◽  
Basic Data ◽  
University Of Oxford ◽  
Obstetrics And Gynaecology ◽  
Nuffield Department ◽  
John Radcliffe Hospital ◽  
Prostaglandin F ◽  
Prostaglandins E

Nuffield Department of Obstetrics and Gynaecology, University of Oxford, John Radcliffe Hospital, Headington, Oxford, OX3 9DU (Received 9 February 1978) It has been shown that prostaglandins play an important role in the mechanism of parturition in many species, including the goat (Currie & Thorburn, 1977; Thorburn, Challis & Robinson, 1977). Recently we have demonstrated that intra-uterine tissues from pregnant goats, when superfused in vitro, produce prostaglandins E and F (PGE, PGF) and 13,14-dihydro-15-oxo-prostaglandin F at various rates (Mitchell, Flint, Robinson & Thorburn, 1978). The exciting discoveries of two potent prostaglandin-like compounds, thromboxane A2 (TXA2; Hamberg, Svensson & Samuelsson, 1975) and prostacyclin (PGI2; Moncada, Gryglewski, Bunting & Vane, 1976), have radically altered our thinking on prostaglandins and basic data are urgently required concerning these compounds. Since prostaglandin endoperoxides are the immediate precursors of both prostaglandins and TXA2 (and PGI2) and since TXA2 has been shown to cause contraction of a number

CONCENTRATIONS OF 6-OXO-PROSTAGLANDIN F1α AND THROMBOXANE B2 IN THE TRACHEAL FLUID OF FOETAL SHEEP

1978 ◽  
Vol 79 (3) ◽  
pp. 403-404
Author(s):  
M. D. MITCHELL ◽  
J. S. ROBINSON
Keyword(s):  
Smooth Muscle ◽  
Guinea Pig ◽  
Guinea Pigs ◽  
University Of Oxford ◽  
Obstetrics And Gynaecology ◽  
Nuffield Department ◽  
John Radcliffe Hospital ◽  
Prostaglandin F ◽  
Tracheal Insufflation ◽  
Prostaglandins E

Nuffield Department of Obstetrics and Gynaecology, University of Oxford, John Radcliffe Hospital, Headington, Oxford, OX3 9DU (Received 21 July 1978) Prostaglandins of the E and F series have been shown to relax or contract respectively guinea-pig trachea and recently it has been demonstrated that the prostaglandin endoperoxides PGG2 and PGH2 (immediate precursors of prostaglandins E and F) have far greater potency in contracting tracheal smooth muscle than prostaglandin F (Hamberg, Svensson, Hedqvist, Strandberg & Samuelsson, 1976). Furthermore, both thromboxane A2 and prostacyclin can also elicit contraction of the trachea with thromboxane A2 being considerably more active (Omini, Moncada & Vane, 1977; Svensson, Strandberg, Tuvemo & Hamberg, 1977). Administration of thromboxane A2 has been shown to raise the tracheal insufflation pressure in guinea-pigs (Svensson et al. 1977) and indeed its stable metabolite thromboxane B2 is released in relatively large amounts from sensitized guinea-pig lungs when challenged with antigen (Dawson, Boot, Cockerill,

EFFECT OF SOMATOSTATIN ON THE CONCENTRATION OF GROWTH HORMONE IN THE PLASMA OF FOETAL SHEEP

1978 ◽  
Vol 78 (3) ◽  
pp. 453-454 ◽  
Author(s):  
I. C. McMILLEN ◽  
G. JENKIN ◽  
G. D. THORBURN ◽  
J. S. ROBINSON
Keyword(s):  
Growth Hormone ◽  
Pituitary Gland ◽  
Medical Research ◽  
Pituitary Stalk ◽  
Obstetrics And Gynaecology ◽  
Nuffield Department ◽  
John Radcliffe Hospital ◽  
Ovine Placenta

Nuffield Institute for Medical Research and Nuffield Department of Obstetrics and Gynaecology, John Radcliffe Hospital, Headington, Oxford, 0X3 9DU (Received 6 April 1978) Growth hormone (GH) has been located in the ovine foetal pituitary gland by day 50 of gestation (Stokes & Boda, 1968). The concentration of GH in the plasma of foetal sheep is ten times higher than the postnatal value, increasing from 40 ng/ml on day 100 of gestation to 100–120 ng/ml on day 140 (Bassett, Thorburn & Wallace, 1970). After foetal hypophysectomy, the concentration of GH falls to < 2 ng/ml, indicating that it originates in the foetal pituitary gland (Wallace, Stacey & Thorburn, 1973). Labelled GH does not cross the ovine placenta (Wallace et al. 1973). After sectioning the foetal pituitary stalk, the concentration of GH in the foetal plasma drops to approximately 5 ng/ml (Wallace et al. 1973), which implies that the secretion of GH

INTRA-UTERINE TISSUES FROM LATE-PREGNANT RHESUS MONKEYS (MACACA MULATTA) PRODUCE 6-OXO-PROSTAGLANDIN F1α IN VITRO

1979 ◽  
Vol 81 (3) ◽  
pp. 339-343 ◽  
Author(s):  
M. D. MITCHELL ◽  
B. R. HICKS ◽  
G. D. THORBURN ◽  
J. S. ROBINSON
Keyword(s):  
Caesarean Section ◽  
Macaca Mulatta ◽  
Rhesus Monkeys ◽  
Late Pregnancy ◽  
Unit Weight ◽  
Decidua Basalis ◽  
Prostaglandin F ◽  
Near Term

The rates of production of 6-oxo-prostaglandin F1α (6-oxo-PGF1α) in vitro by intra-uterine tissues taken from late-pregnant monkeys at Caesarean section have been determined. For tissues obtained between days 140 and 149 of pregnancy (late pregnancy) the general quantitative order of rates of production (per unit weight) was decidua basalis> placenta > decidua parietalis>amnion>chorion = myometrium. When tissues were taken between days 160 and 168 of pregnancy (near term) this order was placenta > decidua parietalis = amnion> myometrium = decidua basalis > chorion. There was a significant reduction near term in the rate of production of 6-oxo-PGF1α by decidua basalis; all other tissues exhibited similar rates of production at the two gestational periods investigated.

SPECIFIC CHANGE IN THE DIRECTION OF PROSTAGLANDIN SYNTHESIS BY INTRA-UTERINE TISSUES OF THE RHESUS MONKEY (MACACA MULATTA) DURING LATE PREGNANCY

1978 ◽  
Vol 78 (3) ◽  
pp. 343-350 ◽  
Author(s):  
M. D. MITCHELL ◽  
L. CLOVER ◽  
G. D. THORBURN ◽  
J. S. ROBINSON
Keyword(s):  
Rhesus Monkey ◽  
Macaca Mulatta ◽  
Late Pregnancy ◽  
Prostaglandin Synthesis ◽  
Unit Weight ◽  
Prostaglandin E ◽  
Specific Change ◽  
Decidua Basalis ◽  
Prostaglandin F

The rates of production of prostaglandin E (PGE), prostaglandin F (PGF) and 13,14-dihydro-15-oxo-prostaglandin F (PGFM) by intra-uterine tissues from pregnant monkeys in vitro have been determined using a method of tissue superfusion. The amnion, chorion, placenta, decidua basalis, decidua parietalis and myometrium were obtained at Caesarean section during late pregnancy. Production of PGE by all tissues was significantly lower at term than during late pregnancy, whereas production of PGF by the amnion, chorion, decidua parietalis and myometrium was significantly greater. All tissues produced significantly more PGE than PGF and also, excepting the decidua basalis and decidua parietalis, more PGFM than PGF. Close to parturition the amnion was quantitatively (per unit weight) the major source of prostaglandins. It is suggested that a specific change in the direction of prostaglandin synthesis by intra-uterine tissues occurs near parturition in the rhesus monkey.

scholarly journals Enzymatic Approach in Calcium Phosphate Biomineralization: A Contribution to Reconcile the Physicochemical with the Physiological View

2021 ◽  
Vol 22 (23) ◽  
pp. 12957
Author(s):  
Clément Guibert ◽  
Jessem Landoulsi
Keyword(s):  
Calcium Phosphate ◽  
Soft Tissues ◽  
Biological Systems ◽  
Aqueous Media ◽  
Research Field ◽  
Ion Concentration ◽  
Common Interest ◽  
Inorganic Matter

Biomineralization is the process by which organisms produce hard inorganic matter from soft tissues with outstanding control of mineral deposition in time and space. For this purpose, organisms deploy a sophisticated “toolkit” that has resulted in significant evolutionary innovations, for which calcium phosphate (CaP) is the biomineral selected for the skeleton of vertebrates. While CaP mineral formation in aqueous media can be investigated by studying thermodynamics and kinetics of phase transitions in supersaturated solutions, biogenic mineralization requires coping with the inherent complexity of biological systems. This mainly includes compartmentalization and homeostatic processes used by organisms to regulate key physiological factors, including temperature, pH and ion concentration. A detailed analysis of the literature shows the emergence of two main views describing the mechanism of CaP biomineralization. The first one, more dedicated to the study of in vivo systems and supported by researchers in physiology, often involves matrix vesicles (MVs). The second one, more investigated by the physicochemistry community, involves collagen intrafibrillar mineralization particularly through in vitro acellular models. Herein, we show that there is an obvious need in the biological systems to control both where and when the mineral forms through an in-depth survey of the mechanism of CaP mineralization. This necessity could gather both communities of physiologists and physicochemists under a common interest for an enzymatic approach to better describe CaP biomineralization. Both homogeneous and heterogeneous enzymatic catalyses are conceivable for these systems, and a few preliminary promising results on CaP mineralization for both types of enzymatic catalysis are reported in this work. Through them, we aim to describe the relevance of our point of view and the likely findings that could be obtained when adding an enzymatic approach to the already rich and creative research field dealing with CaP mineralization. This complementary approach could lead to a better understanding of the biomineralization mechanism and inspire the biomimetic design of new materials.

Cerium oxide nanomaterial with dual antioxidative scavenging potential: Synthesis and characterization

2021 ◽  
pp. 088532822110134
Author(s):  
Sushant Singh ◽  
Udit Kumar ◽  
David Gittess ◽  
Tamil S Sakthivel ◽  
Balaashwin Babu ◽  
...  
Keyword(s):  
Cerium Oxide ◽  
Biological Systems ◽  
Mixed Valence ◽  
Stable Solution ◽  
Ability To Act ◽  
Valence States ◽  
Transmission Electron ◽  
Efficient Reduction ◽  
Rich Media

Many studies have linked reactive oxygen species (ROS) to various diseases. Biomedical research has therefore sought a way to control and regulate ROS produced in biological systems. In recent years, cerium oxide nanoparticles (nanoceria, CNPs) have been pursued due to their ability to act as regenerative ROS scavengers. In particular, they are shown to have either superoxide dismutase (SOD) or catalase mimetic (CAT) potential depending on the ratio of Ce3+/Ce4+ valence states. Moreover, it has been demonstrated that SOD mimetic activity can be diminished by the presence of phosphate, which can be a problem given that many biological systems operate in a phosphate-rich environment. Herein, we report a CNP formulation with both SOD and catalase mimetic activity that is preserved in a phosphate-rich media. Characterization demonstrated a highly dispersed, stable solution of uniform-sized, spherical-elliptical shaped CNP of 12 ± 2 nm, as determined through dynamic light scattering, zeta potential, and transmission electron microscopy. Mixed valence states of Ce ions were observed via UV/Visible spectroscopy and XPS (Ce3+/Ce4+ > 1) (Ce3+∼ 62%). X-ray diffraction and XPS confirmed the presence of oxygen-deficient cerium oxide (CeO2-x) particles. Finally, the CNP demonstrated very good biocompatibility and efficient reduction of hydrogen peroxide under in-vitro conditions.

scholarly journals Improved Antioxidant Capacity of Black Tea Waste Utilizing PlantCrystals

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 592 ◽  
Author(s):  
Abraham M. Abraham ◽  
Reem M. Alnemari ◽  
Jana Brüßler ◽  
Cornelia M. Keck
Keyword(s):  
Antioxidant Capacity ◽  
Aqueous Media ◽  
Natural Antioxidants ◽  
Black Tea ◽  
Pharmaceutical Products ◽  
Small Scale ◽  
Alternative Source ◽  
Significant Difference ◽  
Plant Waste

Antioxidants are recommended to prevent and treat oxidative stress diseases. Plants are a balanced source of natural antioxidants, but the poor solubility of plant active molecules in aqueous media can be a problem for the formulation of pharmaceutical products. The potential of PlantCrystal technology is known to improve the extraction efficacy and antioxidant capacity (AOC) of different plants. However, it is not yet proved for plant waste. Black tea (BT) infusion is consumed worldwide and thus a huge amount of waste occurs as a result. Therefore, BT waste was recycled into PlantCrystals using small-scale bead milling. Their characteristics were compared with the bulk-materials and tea infusion, including particle size and antioxidant capacity (AOC) in-vitro. Waste PlantCrystals possessed a size of about 280 nm. Their AOC increased with decreasing size according to the DPPH (1,1-diphenyl-2-picrylhydrazyl) and ORAC (oxygen radical absorbance capacity) assays. The AOC of the waste increased about nine-fold upon nanonization, leading to a significantly higher AOC than the bulk-waste and showed no significant difference to the infusion and the used standard according to DPPH assay. Based on the results, it is confirmed that the PlantCrystal technology represents a natural, cost-effective plant-waste recycling method and presents an alternative source of antioxidant phenolic compounds.

scholarly journals Biocompatible Ir(III) Complexes as Oxygen Sensors for Phosphorescence Lifetime Imaging

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2898
Author(s):  
Ilya S. Kritchenkov ◽  
Anastasia I. Solomatina ◽  
Daria O. Kozina ◽  
Vitaly V. Porsev ◽  
Victor V. Sokolov ◽  
...  
Keyword(s):  
Near Infrared ◽  
Biological Systems ◽  
Aqueous Media ◽  
Oxygen Sensors ◽  
Quantum Yields ◽  
Complete Agreement ◽  
Phosphorescence Lifetime ◽  
Lifetime Imaging ◽  
Nir Emission ◽  
Phosphorescence Lifetime Imaging

Synthesis of biocompatible near infrared phosphorescent complexes and their application in bioimaging as triplet oxygen sensors in live systems are still challenging areas of organometallic chemistry. We have designed and synthetized four novel iridium [Ir(N^C)2(N^N)]+ complexes (N^C–benzothienyl-phenanthridine based cyclometalated ligand; N^N–pyridin-phenanthroimidazol diimine chelate), decorated with oligo(ethylene glycol) groups to impart these emitters’ solubility in aqueous media, biocompatibility, and to shield them from interaction with bio-environment. These substances were fully characterized using NMR spectroscopy and ESI mass-spectrometry. The complexes exhibited excitation close to the biological “window of transparency”, NIR emission at 730 nm, and quantum yields up to 12% in water. The compounds with higher degree of the chromophore shielding possess low toxicity, bleaching stability, absence of sensitivity to variations of pH, serum, and complex concentrations. The properties of these probes as oxygen sensors for biological systems have been studied by using phosphorescence lifetime imaging experiments in different cell cultures. The results showed essential lifetime response onto variations in oxygen concentration (2.0–2.3 μs under normoxia and 2.8–3.0 μs under hypoxia conditions) in complete agreement with the calibration curves obtained “in cuvette”. The data obtained indicate that these emitters can be used as semi-quantitative oxygen sensors in biological systems.

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