scholarly journals The behaviour of thiomolybdates in in vitro systems

1979 ◽  
Vol 41 (2) ◽  
pp. 403-405 ◽  
Author(s):  
K. M. Weber ◽  
D. D. Leaver ◽  
A. G. Wedd
Keyword(s):  
Copper Metabolism ◽  
Hydrogen Ion ◽  
In Vivo Studies ◽  
In Vitro Systems ◽  
The Stability

The stability of potassium tetrathiomolybdate was studied in vitro using solutions with molybdenum, hydrogen ion and phosphate concentrations similar to those normally found in the rumen. Under these conditions K2[MoS4] hydrolysed rapidly and as a result the solution contained [MoS4]2−, [MoOS3]2−, [MoO2S2]2−, [HS]− and H2S in equilibrium. In view of this hydrolysis, in vivo studies of thiomolybdate on copper metabolism of sheep should not exclude the possibility that either sulphide or molybdate is responsible for any observed effect.

scholarly journals Human Oligodendrocytes and Myelin In Vitro to Evaluate Developmental Neurotoxicity

2021 ◽  
Vol 22 (15) ◽  
pp. 7929
Author(s):  
Megan Chesnut ◽  
Thomas Hartung ◽  
Helena Hogberg ◽  
David Pamies
Keyword(s):  
Large Scale ◽  
In Vitro Models ◽  
Environmental Chemicals ◽  
Developmental Neurotoxicity ◽  
In Vivo Studies ◽  
Regulatory Guidelines ◽  
In Vitro Systems ◽  
Human Oligodendrocytes

Neurodevelopment is uniquely sensitive to toxic insults and there are concerns that environmental chemicals are contributing to widespread subclinical developmental neurotoxicity (DNT). Increased DNT evaluation is needed due to the lack of such information for most chemicals in common use, but in vivo studies recommended in regulatory guidelines are not practical for the large-scale screening of potential DNT chemicals. It is widely acknowledged that developmental neurotoxicity is a consequence of disruptions to basic processes in neurodevelopment and that testing strategies using human cell-based in vitro systems that mimic these processes could aid in prioritizing chemicals with DNT potential. Myelination is a fundamental process in neurodevelopment that should be included in a DNT testing strategy, but there are very few in vitro models of myelination. Thus, there is a need to establish an in vitro myelination assay for DNT. Here, we summarize the routes of myelin toxicity and the known models to study this particular endpoint.

scholarly journals Preparation and Preliminary Evaluation of Novel β-Cyclodextrin/IUDR Prodrug Formulations

2008 ◽  
Vol 11 (2) ◽  
pp. 32 ◽  
Author(s):  
Leonard I. Wiebe ◽  
Xiao-Hong Yang ◽  
Shradha Singh ◽  
Jim Diakur
Keyword(s):  
Inclusion Complexes ◽  
In Vivo Studies ◽  
Preliminary Evaluation ◽  
Target Tissue ◽  
Molar Ratios ◽  
Nmr Spectrometry ◽  
Complex Approach ◽  
The Stability

PURPOSE. Iododeoxyuridine (IUdR) has a very short in vivo half-life and consequently achieves low target-tissue concentrations with concomitant lower efficacy than would be predicted from in vitro studies. This work reports the preparation of IUdR:?-cyclodextrin (?-CyD) inclusion complexes designed to reduce in vivo inactivation of IUdR. METHODS. IUdR was derivatized with either 1-adamantanecarbonyl chloride or 4-(1-adamantyl-carbamoyl)butanoic acid, to prepare 5’-O-(1-adamantoyl)-5-iodo-2’-deoxyuridine 1 and 5’-O-(4-(1-adamantylcarbamoyl)butoyl)-5-iodo-2’-deoxy-uridine 4, respectively. ?-CyD complexes 5 and 6 were formed by vigorous stirring of 1:1 solutions of ?-CyD and 1 or 4, respectively, in D2O under argon. Complexation was inferred from DSC, powder x-ray diffractometry and NMR spectrometry. The dissociation of 5 in water and under cholesterol challenge, and the effect of complexation on the stability of 1 was determined by incubation in plasma. RESULTS. IUdR coupling with adamantanecarbonyl chloride proceeded smoothly to afford 1 (69 %) and the di-substituted derivative, 3’,5’-di-O-(1-adamantoyl)-5-iodo-2’-deoxyuridine 2 (8 %); 4 was obtained in 42 % yield. The formation of 1:1 complexes 5 and 6 was inferred from NMR chemical shift data. In serum, 1 was 90 % hydrolyzed to IUdR in 30 min, compared to 10 % hydrolysis of 1 to IUdR when from complex 5. CONCLUSIONS. Inclusion complexes were formed between ?-CyD and adamantamine-IUdR conjugates at 1:1 molar ratios. The complex 5 was resistant to dissociation by cholesterol challenge, and 5 was more slowly converted to IUdR than non-complexed 1. In vivo studies are required to further exploit the ?-CyD inclusion complex approach for improved delivery of nucleoside derivatives.

scholarly journals SPZ1 promotes deregulation of Bim to boost apoptosis resistance in colorectal cancer

2020 ◽  
Vol 134 (2) ◽  
pp. 155-167
Author(s):  
Xiao-Yu Liu ◽  
Chang-Bo Zheng ◽  
Teng Wang ◽  
Jian Xu ◽  
Meng Zhang ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cell Growth ◽  
Clinical Stage ◽  
In Vivo Studies ◽  
Apoptosis Resistance ◽  
Advanced Clinical Stage ◽  
Helix Loop Helix ◽  
The Stability

Abstract Colorectal cancer (CRC) is the third most common malignancies in adults. Similar to other solid tumors, CRC cells show increased proliferation and suppressed apoptosis during the development and progression of the disease. Previous studies have shown that a novel tumor oncogene, spermatogenic basic helix-loop-helix transcription factor zip 1 (SPZ1), can promote proliferation. However, it is unclear whether SPZ1 plays a role in suppressing apoptosis, and the molecular mechanism behind SPZ1’s suppression of apoptosis in CRC remains unclear. Here, we found that silencing endogenous SPZ1 inhibits cell growth and induces apoptosis, and overexpression of SPZ1 promotes cell growth. These findings were corroborated by in vitro and in vivo studies. Interestingly, SPZ1 overexpressing cells were resistant to 5-fluorouracil, a drug commonly used to treat cancer. Moreover, knocking down SPZ1 led to the activation of caspase through the deregulation of Bim by ERK1/2, we found that CRC tissues had significantly higher SPZ1 and lower Bim expression, and SPZ1HBimL were associated with advanced clinical stage of CRC. Collectively, our findings demonstrate that SPZ1 contributes to tumor progression by limiting apoptosis. SPZ1 reduces apoptosis by altering the stability of Bim, suggesting SPZ1 may serve as a biomarker and therapeutic target for CRC.

scholarly journals In-Silico Evaluation of Tiryaq-E-Wabai, an Unani Formulation for its Potency against SARS-CoV-2 Spike Glycoprotein and Main Protease

2021 ◽  
Vol 11 (4-S) ◽  
pp. 86-100
Author(s):  
N ZAHEER AHMED ◽  
DICKY JOHN DAVIS ◽  
NOMAN ANWAR ◽  
ASIM ALI KHAN ◽  
RAM PRATAP MEENA ◽  
...  
Keyword(s):  
In Silico ◽  
Dynamics Simulation ◽  
In Vivo Studies ◽  
Spike Glycoprotein ◽  
Unani Medicine ◽  
Main Protease ◽  
Pubchem Database ◽  
The Stability

COVID-19 was originated in Wuhan, China, in December 2019 and has been declared a pandemic disease by WHO. The number of infected cases continues unabated and so far, no specific drug approved for targeted therapy. Hence, there is a need for drug discovery from traditional medicine. Tiryaq-e-Wabai is a well-documented formulation in Unani medicine for its wide use as prophylaxis during epidemics of cholera, plague and other earlier epidemic diseases. The objective of the current study is to generate in-silico evidence and evaluate the potency of Tiryaq-e-Wabai against SARS-CoV-2 spike (S) glycoprotein and main protease (3CLpro). The structures of all phytocompounds used in this study were retrieved from PubChem database and some were built using Marvin Sketch. The protein structure of the SARS-CoV-2 S glycoprotein and 3CLpro was retrieved from the PDB ID: 6LZG and 7BQY respectively. AutoDock Vina was used to predict top ranking poses with best scores. The results of the molecular docking showed that phytocompounds of Tiryaq-e-Wabai exhibited good docking power with spike glycoprotein and 3CLpro. Among tested compounds Crocin from Zafran and Aloin A from Sibr showed strong binding to spike glycoprotein and 3CLpro respectively. Molecular dynamics simulation confirmed the stability of the S glycoprotein-Crocin and 3CLpro-Aloin A complexes. The Unani formulation Tiryaq-e-Wabai has great potential to inhibit the SARS-CoV-2, which have to be substantiated with further in-vitro and in-vivo studies. Keywords: In-silico study, SARS-CoV-2, Tiryaq-e-Wabai, Unani formulation, Crocin, Aloin A

Dimer-tetramer transition controls RUNX1/ETO leukemogenic activity

Blood ◽  
2010 ◽  
Vol 116 (4) ◽  
pp. 603-613 ◽  
Author(s):  
Christian Wichmann ◽  
Yvonne Becker ◽  
Linping Chen-Wichmann ◽  
Vitali Vogel ◽  
Anna Vojtkova ◽  
...  
Keyword(s):  
Amino Acids ◽  
Hot Spot ◽  
Chromosomal Translocation ◽  
Structural Motif ◽  
In Vivo Studies ◽  
Tetramerization Domain ◽  
The Stability ◽  
Transplantation Model

Abstract RUNX1/ETO, the fusion protein resulting from the chromosomal translocation t(8;21), is one of the most frequent translocation products in acute myeloid leukemia. Several in vitro and in vivo studies have shown that the homo-tetramerization domain of ETO, the nervy homology region 2 (NHR2), is essential for RUNX1/ETO oncogenic activity. We analyzed the energetic contribution of individual amino acids within the NHR2 to RUNX1/ETO dimer-tetramer transition and found a clustered area of 5 distinct amino acids with strong contribution to the stability of tetramers. Substitution of these amino acids abolishes tetramer formation without affecting dimer formation. Similar to RUNX1/ETO monomers, dimers failed to bind efficiently to DNA and to alter expression of RUNX1-dependent genes. RUNX1/ETO dimers do not block myeloid differentiation, are unable to enhance the self-renewal capacity of hematopoietic progenitors, and fail to induce leukemia in a murine transplantation model. Our data reveal the existence of an essential structural motif (hot spot) at the NHR2 dimer-tetramer interface, suitable for a molecular intervention in t(8;21) leukemias.

scholarly journals AN INTEGRATIVE BIOLOGY APPROACH TO QUANTIFY THE BIODISTRIBUTION OF AZIDOHOMOALANINE IN VIVO

2021 ◽  
Author(s):  
Aya M. Saleh ◽  
Tyler G. VanDyk ◽  
Kathryn Jacobson ◽  
Sarah Calve ◽  
Tamara L. Kinzer-Ursem
Keyword(s):  
Protein Dynamics ◽  
Compartmental Model ◽  
In Vivo Studies ◽  
Cellular Functions ◽  
Plasma Metabolome ◽  
In Vivo Labeling ◽  
In Vitro Systems ◽  
The Impact

Identification and quantitation of newly synthesized proteins (NSPs) are critical to understanding protein dynamics in development and disease. Probing the nascent proteome can be achieved using non-canonical amino acids (ncAAs) to selectively label the NSPs utilizing endogenous translation machinery, which can then be quantitated with mass spectrometry. Since its conception, ncAA labeling has been applied to study many in vitro systems and more recently the in vivo proteomes of complex organisms such as rodents. In vivo labeling is typically achieved by introducing ncAAs into diet, which requires extended labeling times. We have previously demonstrated that labeling the murine proteome is feasible via injection of azidohomoalanine (Aha), a ncAA and methionine (Met) analog, without the need for Met depletion. With the ability to isolate NSPs without applying stress from dietary changes, Aha labeling can address biological questions wherein temporal protein dynamics are significant. However, accessing this temporal resolution requires a more complete understanding of Aha distribution kinetics in tissues. Furthermore, studies of physiological effects of ncAA administration have been limited to gross observation of animal appearance. To address these gaps, we created a deterministic, compartmental model of the biokinetic transport and incorporation of Aha in mice. Parameters were informed from literature and experimentally. Model results demonstrate the ability to predict Aha distribution and labeling under a variety of dosing paradigms and confirms the use of the model as a tool for design of future studies. To establish the suitability of the method for in vivo studies, we investigated the impact of Aha administration on normal physiology by analyzing the plasma metabolome following Aha injection. We show that Aha administration does not significantly perturb cellular functions as reflected by an unchanged plasma metabolome compared to non-injected controls.

Formation and Structure of Casein Micelles in Lactating Mammary Tissue

1970 ◽  
Vol 28 ◽  
pp. 150-151
Author(s):  
Robert J. Carroll ◽  
Marvin P. Thompson ◽  
Harold M. Farrell
Keyword(s):  
Size Distribution ◽  
G Protein ◽  
Milk Proteins ◽  
Mammary Tissue ◽  
Colloidal System ◽  
Casein Micelles ◽  
The Stability

Milk is an unusually stable colloidal system; the stability of this system is due primarily to the formation of micelles by the major milk proteins, the caseins. Numerous models for the structure of casein micelles have been proposed; these models have been formulated on the basis of in vitro studies. Synthetic casein micelles (i.e., those formed by mixing the purified αsl- and k-caseins with Ca2+ in appropriate ratios) are dissimilar to those from freshly-drawn milks in (i) size distribution, (ii) ratio of Ca/P, and (iii) solvation (g. water/g. protein). Evidently, in vivo organization of the caseins into the micellar form occurs in-a manner which is not identical to the in vitro mode of formation.

In vitro and in vivo studies of new cationic Zn(II)‐benzonaphthoporphyrazines as photosensitizers for PDT

2001 ◽  
Vol 5 (8) ◽  
pp. 645-651
Author(s):  
M. Peeva ◽  
M. Shopova ◽  
U. Michelsen ◽  
D. Wöhrle ◽  
G. Petrov ◽  
...  
Keyword(s):  
In Vivo Studies

Effect of caffeine on theophyliine on cerebral blood flow response to brain activation: In vitro and in vivo studies

2005 ◽  
Vol 25 (1_suppl) ◽  
pp. S198-S198
Author(s):  
Joseph R Meno ◽  
Thien-son K Nguyen ◽  
Elise M Jensen ◽  
G Alexander West ◽  
Leonid Groysman ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Brain Activation ◽  
In Vivo Studies ◽  
Blood Flow Response ◽  
Flow Response
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