scholarly journals Comparison of the Bioavailability of Waste Laden Soils Using ''In Vivo'' ''In Vitro'' Analytical Methodology and Bioaccessibility of Radionuclides for Refinement of Exposure/Dose Estimates

10.2172/14331 ◽  
1999 ◽  
Author(s):  
P. J. Lioy ◽  
M. Gallo ◽  
P. Georgopoulos ◽  
R. Tate ◽  
B. Buckley
Keyword(s):  
Exposure Dose ◽  
Analytical Methodology

scholarly journals Novel and Modified Neutrophil Elastase Inhibitor Loaded in Topical Formulations for Psoriasis Management

Pharmaceutics ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 358 ◽  
Author(s):  
Andreia Nunes ◽  
Joana Marto ◽  
Lídia Maria Gonçalves ◽  
Sandra Simões ◽  
Rita Félix ◽  
...  
Keyword(s):  
Serine Protease ◽  
Neutrophil Elastase ◽  
In Vitro Cytotoxicity ◽  
Human Neutrophil Elastase ◽  
Therapeutic Effects ◽  
Neutrophil Elastase Inhibitor ◽  
Analytical Methodology ◽  
Elastase Inhibitor

Human neutrophil elastase (HNE) is a serine protease that degrades matrix proteins. An excess of HNE may trigger several pathological conditions, such as psoriasis. In this work, we aimed to synthesize, characterize and formulate new HNE inhibitors with a 4-oxo-β-lactam scaffold with less toxicity, as well as therapeutic index in a psoriasis context. HNE inhibitors with 4-oxo-β-lactam scaffolds were synthesized and characterized by NMR, FTIR, melting point, mass spectrometry and elemental analysis. In vitro cytotoxicity and serine protease assays were performed. The compound with the highest cell viability (AAN-16) was selected to be incorporated in an emulsion (AAN-16 E) and in a microemulsion (AAN-16 ME). Formulations were characterized in terms of organoleptic properties, pH, rheology, droplet size distribution, in vitro drug release and in vivo psoriatic activity. All compounds were successfully synthesized according to analytical methodology, with good yields. Both formulations presented suitable physicochemical properties. AAN-16 E presented the most promising therapeutic effects in a murine model of psoriasis. Overall, new HNE inhibitors were synthesized with high and selective activity and incorporated into topical emulsions with potential to treat psoriasis.

Quantification of the Active Decitabine-Triphosphate (DAC-TP) Metabolite: A Novel Pharmacoanalytical Endpoint for Optimization of Hypomethylating Therapy in Acute Myeloid Leukemia (AML)

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3578-3578
Author(s):  
Hongyan Wang ◽  
Ping Chen ◽  
Jiang Wang ◽  
Ramasamy Santhanam ◽  
Josephine Aimiuwu ◽  
...  
Keyword(s):  
Mononuclear Cells ◽  
Conflicts Of Interest ◽  
Dna Methyltransferases ◽  
Analytical Methodology ◽  
In Vivo Experiments ◽  
Accuracy And Precision ◽  
Coefficients Of Variation ◽  
The Mean

Abstract Abstract 3578 Decitabine (DAC) is successfully used for treatment of patients (pts) with myelodysplastic syndromes and AML. Following cellular uptake, DAC is thought to be activated to DAC-TP and incorporated into DNA. The DAC-TP/DNA complex binds and inactivates DNA methyltransferases (DNMTs), thereby leading to hypomethylation and re-expression of epigenetically silenced tumor suppressor genes and ultimately anti-leukemia activity. However, direct evidence of in vivo DAC-TP occurrence in DAC-treated pts has been difficult to demonstrate due to a lack of suitable validated analytical methodology. Thus, we developed and validated a sensitive and specific LC-MS/MS method for quantification of DAC-TP. The assay exhibited excellent accuracy and precision. The accuracy values were 83.7–109.4%, as determined by calculating the percentage of measured DAC-TP relative to the respective nominal concentrations (50, 500 and 5,000 nM) of the quality control samples. The within-day coefficients of variation (CVs) were 19.9 % (n=6) at 50 nM and 4.7–7.0 % between 500–5,000 nM; the between-day CVs (n=3) were 15.2 % at 50 nM and 7.5–10.2 % between 500–5,000 nM. Following DAC treatment, we detected DAC-TP in parental and DAC-resistant MV4–11, and in THP-1 and FDC-P1/Kitmut cells (in vitro); and in bone marrow (BM) and spleen of normal and FDC-P1/Kitmut-driven AML mice (in vivo). DAC-TP reached peak levels (0.8, 1.4 and 0.5 pmol/106 cells) in 1–4 hours and declined to 20 % of its peak concentration after 24 hours incubation with 2.5 μM DAC in MV4–11, THP-1 and FDC-P1/Kitmut cells, respectively. Inhibition of hENT1 that mediates DAC transport into the cells and dCK that phosphorylates DAC into DAC-TP by NBTI and 2-thio-2′-deoxycytidine, respectively, significantly inhibited DAC-TP accumulation in AML cells. DAC-TP decay was instead blocked by tetrahydrouridine (THU)-induced inhibition of CDA, the catabolizing enzyme for cytidine and deoxycytidine and analogs. Consistent with these results, low dCK and hENTs but not CDA expression were detected in DAC-resistant MV4–11 cells, which showed 60 % decrease in DAC-TP levels as compared to their parental counterparts. DAC/DAC-TP-mediated downregulation of DNMT proteins (preferentially DNMT1 and DNMT3a) was also demonstrated in the AML cells even at DAC-TP concentrations as low as 0.1–1.3 pmol/106 cells in vitro after 4 hours DAC incubation. In the in vivo experiments, DAC-TP levels in leukemic mice were comparable to that in normal C57BL/6 mice, 0.3 pmol/106 cells in BM and 199.2 pmol/g tissue in spleen at 4-hours and 0.2 pmol/106 cells in BM and 165.3 pmol/g tissue in spleen at 24-hours following an i.v. bolus of 6.5 mg/kg DAC. In BM of leukemic mice, not only DNMT1 and DNMT3a but also DNMT3b protein expression reduced 80 % (DNMT3a) or diminished (DNMT1 and DNMT3b). The clinical applicability of this method was proven by measuring DAC-TP level in BM and blood mononuclear cells (PBMC) from AML pts treated with a 10-day regimen of DAC given 20 mg/m2/day i.v. over 1 hour. In BM samples, the mean DAC-TP levels were 0.8 ± 0.6 (Day 1) and 0.9 ± 0.5 pmol/106 cells (Day∼5) in complete responsive (CR) pts (n=4); and 0.4 ± 0.3 (Day 1) and 0.12 ± 0.02 pmol/106 cells (Day∼5) in non-responsive (NR) pts (n=3). In PBMC samples, the mean DAC-TP levels were 0.5 ± 0.2 (Day 1) and 1.2 ± 0.4 pmol/106 cells (Day∼5) in CR pts (n=3); and 0.02 ± 0.02 (Day 1) and 0.21 ± 0.04 pmol/106 cells (Day∼5) in NR pts (n=3). These data suggested that higher levels are seemingly associated with clinical response, but a larger number of pts need to be tested. In conclusion, monitoring the intracellular concentration of DAC-TP is feasible, and DAC-TP levels correlate with DNMT downregulation and may serve as a novel pharmacological endpoint for designing more effective DAC-based regimens. Disclosures: No relevant conflicts of interest to declare.

Tocopherol Fate in Plasma and Liver of Streptozotocin-Treated Rats that Orally Received Antioxidants and Spirulina Extracts

2007 ◽  
Vol 77 (4) ◽  
pp. 263-271 ◽  
Author(s):  
García-Martínez ◽  
Rupérez ◽  
Ugarte ◽  
Barbas
Keyword(s):  
Antioxidant Activity ◽  
Vitamin E ◽  
Storage Conditions ◽  
Tocopherol Content ◽  
Diabetic Rats ◽  
Tocopherol Concentration ◽  
Analytical Methodology ◽  
Before And After

Streptozotocin-induced diabetic rats constitute a model of oxidative stress, and vitamin E continues to be a topic of speculation in this area. On the other hand, marine extracts, particularly microalgae extracts obtained with environmentally clean technologies and which demonstrate antioxidant activity in vitro, are a potential source of in vivo antioxidant defense. We have studied the α-tocopherol content in the plasma and liver of diabetic rats after 7 and 14 days under the condition, and before and after the treatment with vitamin E and C, as well as with different Spirulina extracts, as compared with the corresponding controls. The improvement of analytical methodology related to the determination of α-tocopherol in the plasma and liver of rats was also considered. To do this, a method previously developed for plasma, employing a single extraction step, was adapted and validated for liver after minor modifications. Moreover, stability of α-tocopherol in plasma of diabetic and control animals was compared in different storage conditions. Results showed that diabetic plasma strongly influences stability of α-tocopherol, even at –20° C, but samples are stable for at least one year at –80° C. Finally, regarding supplementation, results indicate that supplementation with α-tocopherol increases stored α-tocopherol in liver, but not in plasma, but this availability is strongly dependent on the stage of diabetes of the animal. Extracts of Spirulina platensis, despite showing antioxidant activity in vitro, increased α-tocopherol concentration in neither plasma nor liver.

scholarly journals Evaluation of a Propolis Water Extract Using a Reliable RP-HPLC Methodology andIn VitroandIn VivoEfficacy and Safety Characterisation

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Bruno Alves Rocha ◽  
Paula Carolina Pires Bueno ◽  
Mirela Mara de Oliveira Lima Leite Vaz ◽  
Andresa Piacezzi Nascimento ◽  
Nathália Ursoli Ferreira ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Biological Activities ◽  
Water Extract ◽  
Ethanolic Extract ◽  
Hplc Method ◽  
Analytical Methodology ◽  
Rp Hplc ◽  
Similar Chemical

Since the beginning of propolis research, several groups have studied its antibacterial, antifungal, and antiviral properties. However, most of these studies have only employed propolis ethanolic extract (PEE) leading to little knowledge about the biological activities of propolis water extract (PWE). Based on this, in a previous study, we demonstrated the anti-inflammatory and immunomodulatory activities of PWE. In order to better understand the equilibrium between effectiveness and toxicity, which is essential for a new medicine, the characteristics of PWE were analyzed. We developed and validated an RP-HPLC method to chemically characterize PWE and PEE and evaluated thein vitroantioxidant/antimicrobial activity for both extracts and the safety of PWE via determining genotoxic potential usingin vitroandin vivomammalian micronucleus assays. We have concluded that the proposed analytical methodology was reliable, and both extracts showed similar chemical composition. The extracts presented antioxidant and antimicrobial effects, while PWE demonstrated higher antioxidant activity and more efficacious for the most of the microorganisms tested than PEE. Finally, PWE was shown to be safe using micronucleus assays.

scholarly journals Use of an in silico knowledge discovery approach to determine mechanistic studies of silver nanoparticles-induced toxicity from in vitro to in vivo

2022 ◽  
Vol 19 (1) ◽  
Author(s):  
Bin-Hsu Mao ◽  
Yi-Kai Luo ◽  
Bour-Jr Wang ◽  
Chun-Wan Chen ◽  
Fong-Yu Cheng ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Knowledge Discovery ◽  
Exposure Time ◽  
In Silico ◽  
Surface Coating ◽  
Exposure Dose ◽  
Morphological Observation ◽  
Cell Type

Abstract Background Silver nanoparticles (AgNPs) are considered a double-edged sword that demonstrates beneficial and harmful effects depending on their dimensions and surface coating types. However, mechanistic understanding of the size- and coating-dependent effects of AgNPs in vitro and in vivo remains elusive. We adopted an in silico decision tree-based knowledge-discovery-in-databases process to prioritize the factors affecting the toxic potential of AgNPs, which included exposure dose, cell type and AgNP type (i.e., size and surface coating), and exposure time. This approach also contributed to effective knowledge integration between cell-based phenomenological observations and in vitro/in vivo mechanistic explorations. Results The consolidated cell viability assessment results were used to create a tree model for generalizing cytotoxic behavior of the four AgNP types: SCS, LCS, SAS, and LAS. The model ranked the toxicity-related parameters in the following order of importance: exposure dose > cell type > particle size > exposure time ≥ surface coating. Mechanistically, larger AgNPs appeared to provoke greater levels of autophagy in vitro, which occurred during the earlier phase of both subcytotoxic and cytotoxic exposures. Furthermore, apoptosis rather than necrosis majorly accounted for compromised cell survival over the above dosage range. Intriguingly, exposure to non-cytotoxic doses of AgNPs induced G2/M cell cycle arrest and senescence instead. At the organismal level, SCS following a single intraperitoneal injection was found more toxic to BALB/c mice as compared to SAS. Both particles could be deposited in various target organs (e.g., spleen, liver, and kidneys). Morphological observation, along with serum biochemical and histological analyses, indicated that AgNPs could produce pancreatic toxicity, apart from leading to hepatic inflammation. Conclusions Our integrated in vitro, in silico, and in vivo study revealed that AgNPs exerted toxicity in dose-, cell/organ type- and particle type-dependent manners. More importantly, a single injection of lethal-dose AgNPs (i.e., SCS and SAS) could incur severe damage to pancreas and raise blood glucose levels at the early phase of exposure.

scholarly journals An in vitro assay and artificial intelligence approach to determine rate constants of nanomaterial-cell interactions

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Edward Price ◽  
Andre J. Gesquiere
Keyword(s):  
Artificial Intelligence ◽  
Exposure Dose ◽  
Cellular Level ◽  
Screening Tools ◽  
Biological Interactions ◽  
Vitro Assay ◽  
Cellular Environment ◽  
Cell Simulation

Abstract In vitro assays and simulation technologies are powerful methodologies that can inform scientists of nanomaterial (NM) distribution and fate in humans or pre-clinical species. For small molecules, less animal data is often needed because there are a multitude of in vitro screening tools and simulation-based approaches to quantify uptake and deliver data that makes extrapolation to in vivo studies feasible. Small molecule simulations work because these materials often diffuse quickly and partition after reaching equilibrium shortly after dosing, but this cannot be applied to NMs. NMs interact with cells through energy dependent pathways, often taking hours or days to become fully internalized within the cellular environment. In vitro screening tools must capture these phenomena so that cell simulations built on mechanism-based models can deliver relationships between exposure dose and mechanistic biology, that is biology representative of fundamental processes involved in NM transport by cells (e.g. membrane adsorption and subsequent internalization). Here, we developed, validated, and applied the FORECAST method, a combination of a calibrated fluorescence assay (CF) with an artificial intelligence-based cell simulation to quantify rates descriptive of the time-dependent mechanistic biological interactions between NMs and individual cells. This work is expected to provide a means of extrapolation to pre-clinical or human biodistribution with cellular level resolution for NMs starting only from in vitro data.

Permanent CIED malfunctions after oncologic radiotherapy: a multi-centre, randomized, in vitro evaluation

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
E Di Girolamo ◽  
M Appignani ◽  
M Faustino ◽  
M Marini ◽  
P De Filippo ◽  
...  
Keyword(s):  
Treatment Plan ◽  
Exposure Dose ◽  
In Vivo Dosimetry ◽  
Implantable Cardioverter Defibrillators ◽  
Direct Exposure ◽  
Rate Adaptive ◽  
Photon Exposure

Abstract Background Direct photon exposure of pacemakers (PMs) or implantable cardioverter-defibrillators (ICDs) during oncologic radiotherapy may transiently or permanently affect normal device function. To evaluate potential malfunctions by direct exposure to doses up to 10 Gy in 6-MV oncologic radiotherapy, commonly considered unsafe or even not recommended, 145 PMs and 65 ICDs were observed in three different centres. Methods All devices had a baseline interrogation and reprogramming to VVI/40 or to DDD/40 mode, depending on type and model. Rate-adaptive function was disabled in all the devices, whereas in ICDs, even antitachycardia therapies were disabled with the ventricular tachycardia/fibrillation (VT/VF) windows left enabled. To build the corresponding treatment plan, a centring computed tomography was performed with different Treatment Plan Systems among the centres. The devices were blinded randomized to receive either 2-, 5- or 10-Gy direct exposure by a 6-MV linear accelerator (different among the three centres) in a water phantom (600 MU/min). The effective dose received was assessed by a random in-vivo dosimetry. All devices had a telemetry interrogation immediately after exposure and once monthly during a six-month follow-up. Results Immediately after photon exposure, no changes in device parameters or software errors were observed in 209 devices (99.5%). A non-reprogrammable reset to emergency back-up mode (VVI/65) occurred in a PM (0.5% overall; 0.7% among PMs). Seven PMs reached the Elective Replacement Indicator immediately after exposure (3.3% overall; 4.8% among PMs). Sixteen ICDs (7.6% overall; 24.6% among ICDs) had multiple VT/VF detections stored in the device memory. Two PMs (1% overall; 1.4% among PMs) reported atrial fibrillation detections. During a six-month follow-up, a non-reprogrammable software reset (back-up to VVI/65 mode) was reported in one PM three months after a single exposure of 2 Gy (0.5% overall; 0.7% among PMs). Abnormal battery drain was observed in thirteen PMs (6.2% overall; 9% among PMs), and in one ICD (0.5% overall; 1.5% among ICDs). All events presented regardless of exposure dose of either 2, 5, or 10 Gy. Conclusions Last-generation devices, both PMs and ICDs, withstood direct 6-MV photon exposure up to 10 Gy, commonly considered not recommended or even unsafe by manufacturer statements and clinical guidelines. The most common failures were referred to battery issues. Malfunctions occurred solely in less recent devices, regardless of photon dose. Funding Acknowledgement Type of funding source: None

Induction and Differentiation of Dental Epithelium in Vivo and in Vitro

1982 ◽  
Vol 40 ◽  
pp. 142-145
Author(s):  
E. J. Kollar
Keyword(s):  
Connective Tissue ◽  
Oral Mucosa ◽  
Basal Lamina ◽  
Functional Derivatives ◽  
Specific Source ◽  
Dental Epithelium ◽  
Connective Tissue Stroma

The differentiation and maintenance of many specialized epithelial structures are dependent on the underlying connective tissue stroma and on an intact basal lamina. These requirements are especially stringent in the development and maintenance of the skin and oral mucosa. The keratinization patterns of thin or thick cornified layers as well as the appearance of specialized functional derivatives such as hair and teeth can be correlated with the specific source of stroma which supports these differentiated expressions.

Sign in / Sign up

Export Citation Format

Share Document