scholarly journals Evidence for substrate-cycling of 3-, 3,4-, 4-, and 4,5-phosphorylated phosphatidylinositols in plants

1995 ◽  
Vol 311 (3) ◽  
pp. 1001-1007 ◽  
Author(s):  
C A Brearley ◽  
D E Hanke
Keyword(s):  
Half Life ◽  
Short Term ◽  
Spirodela Polyrhiza ◽  
Phosphatase Activities ◽  
Inositol Phospholipids ◽  
Turnover Process ◽  
Inositol Phospholipid ◽  
Turn Over ◽  
First Time

Short-term 32P labelling and enzymic dissection of inositol phospholipids was used to study the turnover of 3-, 3,4-, 4-, and 4,5-phosphorylated phosphatidylinositols in the plant Spirodela polyrhiza L. Analysis of label in the whole headgroup reveals that phosphatidylinositol 3- and 4-monophosphates (PtdIns3P and PtdIns4P) and phosphatidylinositol 3,4- and 4,5-bisphosphates [PtdIns(3,4)P2 and PtdIns(4,5)P2] all turn over with a half-life of approximately 2-5 h. Analysis of the labelling of individual phosphomonoesters and phosphodiesters of these lipids indicates a rapid equilibration of label between the 4- and 5-monoester phosphates of PtdIns(4,5)P2 within 5 h and largely independent of changes of labelling in the diester. We observed substantially slower equilibration of label (within approximately 27 h) between the monoester and diester of PtdIns4P. These studies therefore indicate that PtdIns4P and PtdIns(4,5)P2 participate in substrate-cycling reactions, evidence for which has been described experimentally only in erythrocytes, and give confirmation in vivo of the previous detection of inositol phospholipid phosphomonoesterase activity. Similar analyses of label in PtdIns3P and PtdIns(3,4)P2 reveal the likely participation of these molecules in substrate cycles and hence for the first time the presence of PtdIns3P 3-phosphatase and PtdIns(3,4)P2 4-phosphatase activities in plants. PtdIns3P and PtdIns(3,4)P2 undergo turnover at rates similar to those of PtdIns4P and PtdIns(4,5)P2. Estimates are made of the relative sizes of the pools of phospholipid participating in the turnover process.

Short-Term Training in Mindfulness Predicts Helping Behavior Toward Racial Ingroup and Outgroup Members

2021 ◽  
pp. 194855062110530
Author(s):  
Daniel R. Berry ◽  
Catherine S. J. Wall ◽  
Justin D. Tubbs ◽  
Fadel Zeidan ◽  
Kirk Warren Brown
Keyword(s):  
Controlled Trial ◽  
Helping Behavior ◽  
Mindfulness Training ◽  
Trait Mindfulness ◽  
Short Term ◽  
Randomized Controlled ◽  
Ecological Momentary ◽  
First Time ◽  
Momentary Assessment

A randomized controlled trial tested whether mindfulness training would increase lab-based and in vivo spontaneous helping behaviors toward racial outgroup members. First, across conditions, those scoring higher in baseline trait mindfulness showed higher levels of preintervention lab-based and ecological momentary assessment (EMA)-based helping behavior. Next, short-term (4-day) training in mindfulness, relative to a well-matched sham meditation training, increased interracial helping behavior in a lab-based simulation. Finally, among people scoring lower in a basic form of trait mindfulness at baseline—that is, with greater room for improvement—mindfulness training predicted higher postintervention in vivo helping behavior reported via EMA. However, neither training condition alone attenuated preferential helping toward racial ingroup members. These findings indicate, for the first time, that mindfulness and its training fosters helping behavior toward strangers and acquaintances regardless of their racial ingroup or outgroup status, but preferential helping of racial ingroup members remains.

scholarly journals Short-term transplantation of isolated human ovarian follicles and cortical tissue into nude mice

Reproduction ◽  
2007 ◽  
Vol 134 (2) ◽  
pp. 253-262 ◽  
Author(s):  
Marie-Madeleine Dolmans ◽  
Belen Martinez-Madrid ◽  
Elodie Gadisseux ◽  
Yves Guiot ◽  
Wu Yuan Yuan ◽  
...  
Keyword(s):  
Nude Mice ◽  
Human Origin ◽  
Cortical Tissue ◽  
Short Term ◽  
Ki 67 ◽  
Primordial Follicles ◽  
Histological Aspect ◽  
The Right ◽  
First Time

This study was designed to evaluate follicular survival and growth after short-term transplantation of fresh isolated human follicles and ovarian cortical tissue to nude mice. Ovarian biopsies were obtained from nine women undergoing laparoscopy. Twelve nude mice were xenografted with an ovarian cortical fragment in the right ovarian bursa, and a clot containing isolated follicles in the left, for a period of 7 days. One ungrafted fragment was used as a control. Histological sections were analyzed to determine follicle number and stage. The proliferative status of follicular cells was assessed by Ki-67 immunostaining. A total of 659 follicles was analyzed by histology and 545 follicles by immunohistochemistry. The percentage of primordial follicles was found to be markedly reduced 1 week post-grafting when compared with ungrafted tissue, while the percentage of primary follicles had significantly increased. Only 8% of follicles showed Ki-67-positive granulosa cells before grafting, whereas 1 week after grafting, 71% of follicles in fragments and 67% of isolated follicles were Ki-67-positive (P<0.001). Moreover, the histological aspect of isolated follicle grafts was similar to that of grafted fragments: follicles were surrounded by vimentin-positive stroma-like tissue of human origin, as confirmed by fluorescent in situ hybridization with human-specific probes. Our results demonstrate, for the first time, that isolated human follicles are able to survive and grow after xenografting. This study also shows massive in vivo follicular activation after transplantation of grafted fragments and isolated follicles. One week after grafting, well-structured stroma-like tissue of human origin was observed around the isolated follicles. The potential origin of this stroma is discussed.

scholarly journals The lability of the products of mitochondrial protein synthesis in Saccharomyces cerevisiae. A novel method for protein half-life determination

1978 ◽  
Vol 170 (3) ◽  
pp. 569-576 ◽  
Author(s):  
G Y Bakalkin ◽  
S L Kalnov ◽  
A V Galkin ◽  
A S Zubatov ◽  
V N Luzikov
Keyword(s):  
Protein Synthesis ◽  
Half Life ◽  
Mitochondrial Protein ◽  
Double Labelling ◽  
Mitochondrial Protein Synthesis ◽  
Mitochondrial Translation ◽  
Novel Method ◽  
The Difference ◽  
First Time

A method for the determination of the half-life of mitochondrial translation products in yeast in vivo is proposed. The method uses inhibitors of cytoplasmic and mitochondrial protein synthesis and is based on double-labelling pulse-chase techniques, the second label being used to estimate ‘post-incorporation’ during the ‘chase’. For the first time the difference between post-incroporation and the widely known recycling of the label is considered. These studies show that, in the turnover of mitochondrial translation products, the problem is of post-incorporation into mitochondria (especially from the cell sap) is predominant. The results obtained with this procedure indicate that the half-life of the products of mitochondrial protein synthesis in yeast at the late-exponential phase is about 60 min. The results suggest that mitochondrial transplantation products are subject to proteolysis to acid-soluble forms.

Kinetics of Various 99mTc-Sn-Pyrophosphate Compounds in the Rat

1977 ◽  
Vol 16 (04) ◽  
pp. 157-162 ◽  
Author(s):  
C. Schümichen ◽  
B. Mackenbrock ◽  
G. Hoffmann
Keyword(s):  
Normal Saline ◽  
Half Life ◽  
Compound A ◽  
Short Half Life ◽  
Low Concentrations ◽  
The Stability ◽  
Kinetics Of ◽  
In Vitro Stability

SummaryThe bone-seeking 99mTc-Sn-pyrophosphate compound (compound A) was diluted both in vitro and in vivo and proved to be unstable both in vitro and in vivo. However, stability was much better in vivo than in vitro and thus the in vitro stability of compound A after dilution in various mediums could be followed up by a consecutive evaluation of the in vivo distribution in the rat. After dilution in neutral normal saline compound A is metastable and after a short half-life it is transformed into the other 99mTc-Sn-pyrophosphate compound A is metastable and after a short half-life in bone but in the kidneys. After dilution in normal saline of low pH and in buffering solutions the stability of compound A is increased. In human plasma compound A is relatively stable but not in plasma water. When compound B is formed in a buffering solution, uptake in the kidneys and excretion in urine is lowered and blood concentration increased.It is assumed that the association of protons to compound A will increase its stability at low concentrations while that to compound B will lead to a strong protein bond in plasma. It is concluded that compound A will not be stable in vivo because of a lack of stability in the extravascular space, and that the protein bond in plasma will be a measure of its in vivo stability.

Half-Life of Platelet Factor 4 (PF-4) in Plasma and Platelets from Macaca Mulatta

1977 ◽  
Vol 37 (01) ◽  
pp. 073-080 ◽  
Author(s):  
Knut Gjesdal ◽  
Duncan S. Pepper
Keyword(s):  
Macaca Mulatta ◽  
Half Life ◽  
Human Platelet ◽  
Gel Filtration ◽  
Platelet Factor 4 ◽  
Active Protein ◽  
Platelet Factor ◽  
Membrane Bound

SummaryHuman platelet factor 4 (PF-4) showed a reaction of complete identity with PF-4 from Macaca mulatta when tested against rabbit anti-human-PF-4. Such immunoglobulin was used for quantitative precipitation of in vivo labelled PF-4 in monkey serum. The results suggest that the active protein had an intra-platelet half-life of about 21 hours. In vitro 125I-labelled human PF-4 was injected intravenously into two monkeys and isolated by immuno-precipita-tion from platelet-poor plasma and from platelets disrupted after gel-filtration. Plasma PF-4 was found to have a half-life of 7 to 11 hours. Some of the labelled PF-4 was associated with platelets and this fraction had a rapid initial disappearance rate and a subsequent half-life close to that of plasma PF-4. The results are compatible with the hypothesis that granular PF-4 belongs to a separate compartment, whereas membrane-bound PF-4 and plasma PF-4 may interchange.

Turnover of Human Extrinsic (Tissue-Type) Plasminogen Activator in Rabbits

1981 ◽  
Vol 46 (03) ◽  
pp. 658-661 ◽  
Author(s):  
C Korninger ◽  
J M Stassen ◽  
D Collen
Keyword(s):  
Plasminogen Activator ◽  
Intravenous Injection ◽  
Active Site ◽  
Half Life ◽  
Degradation Products ◽  
Gel Filtration ◽  
Tissue Type ◽  
Organ Distribution ◽  
Small Rise

SummaryThe turnover of highly purified human extrinsic plasminogen activator (EPA) (one- and two-chain form) was studied in rabbits. Following intravenous injection, EPA-activity declined rapidly. The disappearance rate of EPA from the plasma could adequately be described by a single exponential term with a t ½ of approximately 2 min for both the one-chain and two-chain forms of EPA.The clearance and organ distribution of EPA was studied by using 125I-labeled preparations. Following intravenous injection of 125I-1abeled EPA the radioactivity disappeared rapidly from the plasma also with a t ½ of approximately 2 min down to a level of 15 to 20 percent, followed by a small rise of blood radioactivity. Gel filtration of serial samples revealed that the secondary increase of the radioactivity was due to the reappearance of radioactive breakdown products in the blood. Measurement of the organ distribution of 125I at different time intervals revealed that EPA was rapidly accumulated in the liver, followed by a release of degradation products in the blood.Experimental hepatectomy markedly prolonged the half-life of EPA in the blood. Blocking the active site histidine of EPA had no effect on the half-life of EPA in blood nor on the gel filtration patterns of 125I in serial plasma samples.It is concluded that human EPA is rapidly removed from the blood of rabbits by clearance and degradation in the liver. Recognition by the liver does not require a functional active site in the enzyme. Neutralization in plasma by protease inhibitors does not represent a significant pathway of EPA inactivation in vivo.

Clearance and In Vivo Release by Heparin of Human Platelet Factor 4 (PF4) in the Rabbit

1984 ◽  
Vol 52 (02) ◽  
pp. 157-159 ◽  
Author(s):  
M Prosdocimi ◽  
N Scattolo ◽  
A Zatta ◽  
F Fabris ◽  
F Stevanato ◽  
...  
Keyword(s):  
Half Life ◽  
Human Platelet ◽  
Slow Component ◽  
Platelet Factor 4 ◽  
Platelet Factor ◽  
In Vivo Release ◽  
Partial Release ◽  
Different Doses ◽  
New Zealand Rabbits

Summary13 male New Zealand rabbits were injected with two different doses (25 μg/Kg and 100 μg/Kg) of human platelet factor 4 antigen (PF4). The disappearance of the protein was extremely fast with an half-life for the fast component of 1.07 ± 0.16 and 1.76 ± 0.11 min respectively. The half-life for the slow component, detectable only with the highest dosage, was 18.8 min.The administration of 2500 I.U. of heparin 30 min after PF4 administration induced a partial release of the injected protein and its clearance from plasma was slow, with half-life of 23.3 ± 5.9 min and 30.9 ± 2.19 min respectively.

Effects of short-term saffron (Crocus sativus L.) intake on the in vivo activities of xenobiotic metabolizing enzymes in healthy volunteers

2019 ◽  
Vol 130 ◽  
pp. 32-43 ◽  
Author(s):  
Elias Begas ◽  
Maria Bounitsi ◽  
Thomas Kilindris ◽  
Evangelos Kouvaras ◽  
Konstantinos Makaritsis ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Crocus Sativus ◽  
Short Term ◽  
Metabolizing Enzymes ◽  
Xenobiotic Metabolizing Enzymes ◽  
Crocus Sativus L

scholarly journals Hexapod Assassins’ Potion: Venom Composition and Bioactivity from the Eurasian Assassin Bug Rhynocoris iracundus

Biomedicines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 819
Author(s):  
Nicolai Rügen ◽  
Timothy P. Jenkins ◽  
Natalie Wielsch ◽  
Heiko Vogel ◽  
Benjamin-Florian Hempel ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Galleria Mellonella ◽  
Systemic Reactions ◽  
Venom Composition ◽  
Assassin Bug ◽  
Molecular Components ◽  
First Time ◽  
Tissue Digestion

Assassin bug venoms are potent and exert diverse biological functions, making them potential biomedical goldmines. Besides feeding functions on arthropods, assassin bugs also use their venom for defense purposes causing localized and systemic reactions in vertebrates. However, assassin bug venoms remain poorly characterized. We collected the venom from the assassin bug Rhynocoris iracundus and investigated its composition and bioactivity in vitro and in vivo. It caused lysis of murine neuroblastoma, hepatoma cells, and healthy murine myoblasts. We demonstrated, for the first time, that assassin bug venom induces neurolysis and suggest that it counteracts paralysis locally via the destruction of neural networks, contributing to tissue digestion. Furthermore, the venom caused paralysis and melanization of Galleria mellonella larvae and pupae, whilst also possessing specific antibacterial activity against Escherichia coli, but not Listeria grayi and Pseudomonas aeruginosa. A combinatorial proteo-transcriptomic approach was performed to identify potential toxins responsible for the observed effects. We identified neurotoxic Ptu1, an inhibitory cystin knot (ICK) toxin homologous to ω-conotoxins from cone snails, cytolytic redulysins homologous to trialysins from hematophagous kissing bugs, and pore-forming hemolysins. Additionally, chitinases and kininogens were found and may be responsible for insecticidal and cytolytic activities. We demonstrate the multifunctionality and complexity of assassin bug venom, which renders its molecular components interesting for potential biomedical applications.

Carbon dots derived from Fusobacterium nucleatum for intracellular determination of Fe3+ and bioimaging both in vitro and in vivo

2021 ◽  
Author(s):  
Lijuan Liu ◽  
Shengting Zhang ◽  
Xiaodan Zheng ◽  
Hongmei Li ◽  
Qi Chen ◽  
...  
Keyword(s):  
Carbon Dots ◽  
Fusobacterium Nucleatum ◽  
Living Cells ◽  
First Time ◽  
Fluorescent Carbon Dots ◽  
Fluorescent Carbon

Fusobacterium nucleatum has been employed for the first time to synthesize fluorescent carbon dots which could be applied for the determination of Fe3+ ions in living cells and bioimaging in vitro and in vivo with excellent biocompatibility.

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