Systematic Studies on Temperature-Dependent in Vitro Stability During Storage and Smoking of the Synthetic Cannabinoid 5F-MDMB-P7AICA

2021 ◽  
Author(s):  
Nadja Walle ◽  
Adrian A Doerr ◽  
Matthias W Laschke ◽  
Michael D Menger ◽  
Markus R Meyer ◽  
...  
Keyword(s):  
Degradation Products ◽  
Parent Compound ◽  
Hydrolysis Product ◽  
Synthetic Cannabinoid ◽  
Butanoic Acid ◽  
Serum Samples ◽  
Liquid Chromatography Tandem Mass ◽  
Different Temperatures ◽  
In Vitro Stability

Abstract Metabolism studies have shown that the synthetic cannabinoid (SC) 5F-MDMB-P7AICA is predominantly degraded by ester hydrolysis to 5F-MDMB-P7AICA dimethyl butanoic acid. To investigate the stability of 5F-MDMB-P7AICA during storage for a certain period of time or smoking, in vitro stability tests were performed. Blood and serum samples were collected repeatedly during a toxicokinetic study using a pig model and were retested after a 5 and 12 months storage at different temperatures (-20 °C, 4 °C, or room temperature, RT). Analysis was performed using fully validated liquid chromatography tandem mass spectrometry methods following liquid-liquid extraction and protein precipitation. One set of samples was analyzed immediately following the experiment (WS). In the WS samples, 5F-MDMB-P7AICA and 5F-MDMB-P7AICA dimethyl butanoic acid were present in every sample collected throughout the whole experiment. Analysis of the blood and serum samples stored for 5 and 12 months at -20 °C and 4 °C revealed relatively stable concentrations of the parent substance and the dimethyl butanoic acid metabolite. Regarding the samples stored at RT, concentrations of 5F-MDMB-P7AICA decreased, whilst concentrations of the hydrolysis product increased. This change could particularly be observed in samples with a high initial concentration of the analytes. A further screening of the samples stored at RT revealed no other degradation products. In conclusion, the SC 5F-MDMB-P7AICA could be detected even after 12 months of storage at RT and therefore seems to be more stable than its isomer, 5F-ADB. Regarding the smoke condensate, beside the parent compound only trace amounts of dimethyl butanoic acid were found.

scholarly journals Vitamin D Metabolites and Clinical Outcome in Hospitalized COVID-19 Patients

Nutrients ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 2129
Author(s):  
Sieglinde Zelzer ◽  
Florian Prüller ◽  
Pero Curcic ◽  
Zdenka Sloup ◽  
Magdalena Holter ◽  
...  
Keyword(s):  
Vitamin D ◽  
Degradation Products ◽  
University Hospital ◽  
Vitamin D Metabolites ◽  
Serum Concentrations ◽  
Serum Samples ◽  
Liquid Chromatography Tandem Mass ◽  
Relevant Role ◽  
Metabolite Ratio ◽  
The University

(1) Background: Vitamin D, a well-established regulator of calcium and phosphate metabolism, also has immune-modulatory functions. An uncontrolled immune response and cytokine storm are tightly linked to fatal courses of COVID-19. The present retrospective study aimed to inves-tigate vitamin D status markers and vitamin D degradation products in a mixed cohort of 148 hospitalized COVID-19 patients with various clinical courses of COVID-19. (2) Methods: The serum concentrations of 25(OH)D3, 25(OH)D2, 24,25(OH)2D3, and 25,26(OH)2D3 were determined by a validated liquid-chromatography tandem mass-spectrometry method in leftover serum samples from 148 COVID-19 patients that were admitted to the University Hospital of the Medical Uni-versity of Graz between April and November 2020. Anthropometric and clinical data, as well as outcomes were obtained from the laboratory and hospital information systems. (3) Results: From the 148 patients, 34 (23%) died within 30 days after admission. The frequency of fatal outcomes did not differ between males and females. Non-survivors were significantly older than survivors, had higher peak concentrations of IL-6 and CRP, and required mechanical ventilation more frequently. The serum concentrations of all vitamin D metabolites and the vitamin D metabolite ratio (VMR) did not differ significantly between survivors and non-survivors. Additionally, the need for res-piratory support was unrelated to the serum concentrations of 25(OH)D vitamin D and the two vitamin D catabolites, as well as the VMR. (4) Conclusion: The present results do not support a relevant role of vitamin D for the course and outcome of COVID-19.

scholarly journals Desbutyl-Lumefantrine Is a Metabolite of Lumefantrine with PotentIn VitroAntimalarial Activity That May Influence Artemether-Lumefantrine Treatment Outcome

2011 ◽  
Vol 55 (3) ◽  
pp. 1194-1198 ◽  
Author(s):  
Rina P. M. Wong ◽  
Sam Salman ◽  
Kenneth F. Ilett ◽  
Peter M. Siba ◽  
Ivo Mueller ◽  
...  
Keyword(s):  
Confidence Interval ◽  
High Performance ◽  
Geometric Mean ◽  
Artemisinin Combination Therapy ◽  
Parent Compound ◽  
Plasma Concentrations ◽  
Liquid Chromatography Tandem Mass ◽  
The Mean ◽  
The Relationship

ABSTRACTDesbutyl-lumefantrine (DBL) is a metabolite of lumefantrine. Preliminary data fromPlasmodium falciparumfield isolates show greater antimalarial potency than, and synergy with, the parent compound and synergy with artemisinin. In the present study, thein vitroactivity and interactions of DBL were assessed from tritium-labeled hypoxanthine uptake in cultures of the laboratory-adapted strains 3D7 (chloroquine sensitive) and W2mef (chloroquine resistant). The geometric mean 50% inhibitory concentrations (IC50s) for DBL against 3D7 and W2mef were 9.0 nM (95% confidence interval, 5.7 to 14.4 nM) and 9.5 nM (95% confidence interval, 7.5 to 11.9 nM), respectively, and those for lumefantrine were 65.2 nM (95% confidence interval, 42.3 to 100.8 nM) and 55.5 nM (95% confidence interval, 40.6 to 75.7 nM), respectively. An isobolographic analysis of DBL and lumefantrine combinations showed no interaction in either laboratory-adapted strain but mild synergy between DBL and dihydroartemisinin (sums of the fractional inhibitory concentrations of 0.92 [95% confidence interval, 0.87 to 0.98] and 0.94 [95% confidence interval, 0.90 to 0.99] for 3D7 and W2mef, respectively). Using a validated ultra-high-performance liquid chromatography-tandem mass spectrometry assay and 94 day 7 samples from a previously reported intervention trial, the mean plasma DBL was 31.9 nM (range, 1.3 to 123.1 nM). Mean plasma DBL concentrations were lower in children who failed artemether-lumefantrine treatment than in those with an adequate clinical and parasitological response (ACPR) (P= 0.053 versusP> 0.22 for plasma lumefantrine and the plasma lumefantrine-to-DBL ratio, respectively). DBL is more potent than the parent compound and mildly synergistic with dihydroartemisinin. These properties and the relationship between day 7 plasma concentrations and the ACPR suggest that it could be a useful alternative to lumefantrine as a part of artemisinin combination therapy.

Green Nanotechnology from Brassicaceae

2013 ◽  
Vol 1 ◽  
pp. 194308921350947 ◽  
Author(s):  
Menka Khoobchandani ◽  
Ajit Zambre ◽  
Kavita Katti ◽  
Chung-Ho Lin ◽  
Kattesh V. Katti
Keyword(s):  
Mass Spectrometry ◽  
Gold Nanoparticles ◽  
Biological Fluids ◽  
Biologically Active ◽  
Gas Chromatography Mass Spectrometry ◽  
Therapeutic Effects ◽  
Cytotoxic Effects ◽  
Liquid Chromatography Tandem Mass ◽  
In Vitro Stability

The interaction of cocktail of phytochemicals from broccoli with gold salt results in dual reduction and surface capping to produce well-defined stable and biocompatible gold nanoparticles (B-AuNPs). Broccoli phytochemicals–coated gold nanoparticles (B-AuNPs) have been fully characterized. Detailed in vitro stability in various biological fluids and affinity and selectivity for tumor cells have been investigated. The B-AuNPs showed significant in vitro cytotoxic effects against various cancer cells (MDA-MB-231, PC-3, U266, SkBr3, and T47D) as confirmed by 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium (MTT) and flow cytometry apoptosis assays. Surface encapsulation of cocktail of broccoli phytochemicals on AuNPs facilitates the cellular internalization, thereby validating the in vitro therapeutic effects of these nanoparticles. Detailed analyses performed by combination of gas chromatography–mass spectrometry (GC–MS) and liquid chromatography–tandem mass spectrometry (LC–MS–MS) have confirmed the presence of biologically active phytochemicals including glucoraphanin, phenethyl glucosinolates, quercetin, folic acid, vitamin C, allyl isothiocyanates, 2-phenylethyl isothiocyanates, and sulforaphane. The unique synergistic cocktail effects of B-AuNPs will provide new opportunities for generating biocompatible AuNPs for molecular imaging and therapeutic applications.

scholarly journals Tricyclic Derivative of Acyclovir and Its Esters in Relation to the Esters of Acyclovir Enzymatic Stability: Enzymatic Stability Study

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2156
Author(s):  
Izabela Muszalska-Kolos ◽  
Monika A. Lesniewska-Kowiel ◽  
Szymon Plewa ◽  
Agnieszka Klupczyńska
Keyword(s):  
Degradation Products ◽  
Parent Compound ◽  
Kinetic Studies ◽  
Reversed Phase ◽  
Stability Study ◽  
Porcine Liver ◽  
Enzymatic Stability ◽  
Liver Esterase ◽  
The Stability

The 3,9-dihydro-3-[(2-hydroxyethoxy)methyl]-6-(4-methoxyphenyl)-9-oxo-5H-imidazo[1,2-a]–purine (6-(4-MeOPh)-TACV) was selected to assess the enzymatic stability of the tricyclic acyclovir derivatives from the imidazo[1,2-a]-purine group. The parent compound and its esters (acetyl, isobutyryl, pivaloyl, nicotinic, ethoxycarbonyl) were subjected to kinetic studies and compared with the stability of analogous acyclovir (ACV) esters. The enzymatic hydrolysis was observed in vitro in a medium of 80% human plasma in the absence and presence of porcine liver esterase (PLE). The tests were carried out at 37 °C. To determine the kinetic parameters (kobs., t0.5) of the observed reaction, the validated HPLC-UV method in the reversed phase was used. The HPLC-MS/MS method was used to identify the degradation products under the tested conditions. In summary, it was found that 6-(4-MeOPh)-TACV esters are more susceptible to esterase metabolism than ACV esters. It was confirmed by HPLC-MS/MS that in the plasma, the main product of their hydrolysis is 6-(4-MeOPh)-TACV and not ACV, which confirms that their antiviral activity observed in vitro does not result from ring degradation.

scholarly journals Measurement of Folate in Fresh and Archival Serum Samples as p-Aminobenzoylglutamate Equivalents

2008 ◽  
Vol 54 (4) ◽  
pp. 665-672 ◽  
Author(s):  
Rita Hannisdal ◽  
Asbjørn Svardal ◽  
Per Magne Ueland
Keyword(s):  
Sample Preparation ◽  
Acid Hydrolysis ◽  
Degradation Products ◽  
Serum Folate ◽  
Serum Samples ◽  
Limit Of Quantification ◽  
Fresh Serum ◽  
Liquid Chromatography Tandem Mass ◽  
Automated Sample Preparation ◽  
Good Agreement

Abstract Background: The development of accurate and precise folate assays has been difficult, mainly because of folate instability. Large interassay and interlaboratory differences have been reported. We therefore developed a serum folate assay that measures folate and putative degradation products as p-aminobenzoylglutamate (pABG) equivalents following oxidation and acid hydrolysis. Methods: Serum was deproteinized with acid in the presence of 2 internal calibrators ([13C2]pABG and [13C5]5-methyltetrahydrofolate). 5-Methyltetrahydrofolate and other folate species in serum were converted to pABG by oxidation and mild acid hydrolysis. pABG and its internal calibrators were quantified by liquid chromatography–tandem mass spectrometry (LC-MS/MS). Results: The limit of quantification was 0.25 nmol/L, and the assay was linear in the range 0.25–96 nmol/L, which includes the 99.75 percentile for serum folate concentrations in healthy blood donors. Within- and between-day imprecision was ≤5%. We detected no residual folate in serum samples after sample preparation. Folate concentrations in fresh serum samples obtained with the pABG assay and with a microbiologic assay showed good agreement (r = 0.96). In stored samples containing low folate concentrations due to folate degradation, the pABG assay yielded substantially higher folate concentrations than the microbiologic assay. Conclusions: The pABG assay combines automated sample preparation with LC-MS/MS analysis. It allows measurement of folate not only in fresh samples of serum/plasma but also in stored samples in which the folate has become oxidized and degraded to an extent that it cannot be assayed with traditional folate assays.

In-vitro stability of human alpha-fetoprotein.

1985 ◽  
Vol 31 (10) ◽  
pp. 1692-1697 ◽  
Author(s):  
J T Wu ◽  
J A Knight
Keyword(s):  
Incubation Temperature ◽  
Enzyme Inhibitor ◽  
Alpha Fetoprotein ◽  
Proteolytic Enzyme Inhibitor ◽  
Different Temperatures ◽  
Normal Human ◽  
The Stability ◽  
Phosphate Buffered Saline ◽  
In Vitro Stability

Abstract We assessed the stability of alpha-fetoprotein (AFP) in clinical specimens in the presence and absence of serum and albumin, at different temperatures and concentrations. We find it depends on both AFP concentration and incubation temperature. Dilution of most specimens with either phosphate buffer or phosphate-buffered saline or by immunoelectrodiffusion resulted in some loss of AFP. Attempts to stabilize AFP during either sample dilution or incubation by use of albumin in concentrations up to 1 g/L did not protect it from inactivation unless normal human serum was also included. Frozen AFP solutions were less stable than solutions stored at 4 degrees C. AFP was most stable when lyophilized and stored desiccated. The AFP-inactivation curves were usually nonlinear. Apparently both polymerization and degradation occur simultaneously as AFP loses its activity. Proteolytic enzyme inhibitor and sulfhydryl reagent not only failed to protect it from inactivation, they appeared to speed it.

scholarly journals Serum thyroglobulin evaluation on LC-MS/MS and immunoassay in TgAb-positive patients with papillary thyroid carcinoma

2021 ◽  
Author(s):  
Eijun Nishihara ◽  
Yoshitaka Hobo ◽  
Akira Miyauchi ◽  
Yasuhiro Ito ◽  
Miyoko Higuchi ◽  
...  
Keyword(s):  
Papillary Thyroid Carcinoma ◽  
Thyroid Carcinoma ◽  
Lung Metastases ◽  
In Vitro Assays ◽  
Papillary Thyroid ◽  
Serum Samples ◽  
Serum Thyroglobulin ◽  
Liquid Chromatography Tandem Mass ◽  
Node Metastases

Objective: This study aimed to elucidate disproportionately low serum thyroglobulin (Tg) values in Tg antibody (TgAb)-positive patients with structural recurrence of papillary thyroid carcinoma (PTC) using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Design: A retrospective study was performed on 176 patients in whom Tg and TgAb levels were measured between 2016 and 2021. Several comprehensive analyses of Tg-LC-MS/MS with an electrochemiluminescence immunoassay for Tg (Tg-ECLIA) were conducted using serum samples. Methods: TgAb-positive patients who underwent total thyroidectomy with multiple lung metastases due to PTC were evaluated using Tg-LC-MS/MS and Tg-ECLIA. Tg expression in lymph node metastases and metastatic lesions was evaluated by immunohistochemistry and Tg levels of aspiration washouts. Two in vitro assays were performed to elucidate TgAb interference. Results: Tg concentrations of negative TgAb in both assays were similar (R2=0.99; n=52). Patients with structural recurrence showed higher Tg values with Tg-LC-MS/MS than with Tg-ECLIA. The undetectable proportion was significantly lower with Tg-LC-MS/MS (31.6%, 6/19) than with Tg-ECLIA (68.4%, 13/19; p=0.023). The spike-recovery rate and Tg concentrations determined by the serum mixture text (n=29) were significantly reduced to 75.0% (118.3% to 88.7%) and 81.3% (107.0% to 87.0%), respectively, with TgAb using Tg-ECLIA (both p<0.001) confirming assay interference, but not using Tg-LC-MS/MS (91.8 to 92.3%, p=0.77 and 98.4 to 100.8%, p=0.18, respectively). Conclusions: TgAb had no effect on the Tg-LC-MS/MS assay, but yielded 19%–25% lower values in Tg-ECLIA. Tg-LC-MS/MS is preferable for monitoring serum Tg levels in TgAb-positive patients, although those with structural recurrence often had disproportionally low Tg values.

scholarly journals Optimization of oestradiol assays to improve utility in an in vitro fertilization setting

2017 ◽  
Vol 55 (1) ◽  
pp. 113-120 ◽  
Author(s):  
M Peavey ◽  
N Akbas ◽  
W Gibbons ◽  
P Zarutskie ◽  
S Devaraj
Keyword(s):  
Mass Spectrometry ◽  
In Vitro Fertilization ◽  
Patient Outcomes ◽  
Ovarian Stimulation ◽  
Serum Samples ◽  
Vitro Fertilization ◽  
Chromatography Tandem Mass Spectrometry ◽  
Liquid Chromatography Tandem Mass ◽  
Abbott Architect

Background The measurement of oestradiol is an integral component for the management of ovarian stimulation for in vitro fertilization. Automated immunoassays offer fast assay times and high throughput, with less sensitivity and specificity. The aim of this study is to optimize the oestradiol assay in patients undergoing ovarian stimulation for in vitro fertilization via comparison of oestradiol values obtained using two immunoassays compared with mass spectrometry. Methods Patients undergoing ovarian stimulation were prospectively recruited. Serum samples were analysed with ADVIA Centaur® CP Immunoassay, Abbott Architect i1000® immunoassay and AB Sciex 5500 liquid chromatography-tandem mass spectrometry (LC-MS/MS) systems. Per cent bias was determined for each system to report the average tendency of the values to be larger or smaller than the LC-MS/MS value. Linear regression of total follicular volume and oestradiol was computed. Results The ADVIA Centaur® CP assay had a positive bias of 20% compared with LC-MS/MS, while the Architect i1000® had a non-significant, negative bias of 0.3%. With regression fit, a clear, positive relationship was seen between follicular volume and oestradiol. The Architect i1000® assay had a greater correlation (R2 = 0.46) compared with Centaur® CP (R2 = 0.36), when oestradiol values were >1000 pg/mL (3670 pmol/L). Conclusions The Abbott Architect i1000® oestradiol assay exhibits greater agreement with LC-MS/MS and exhibited better correlation to follicular volume when oestradiol values are >1000 pg/mL (3670 pmol/L), prompting a change in the clinic’s oestradiol platform. Attention to assay quality assurance via LC-MS/MS can improve the oestradiol accuracy and permit more informed clinical decisions for improved patient outcomes.

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.

Rhenium-188 Labeled Hydroxyapatite and Rhenium-188 Sulfur Colloid

1997 ◽  
Vol 36 (02) ◽  
pp. 71-75 ◽  
Author(s):  
S. Glatz ◽  
S. N. Reske ◽  
K. G. Grillenberger
Keyword(s):  
Synovial Fluid ◽  
Ph Value ◽  
Surgical Removal ◽  
Radiation Synovectomy ◽  
Sulfur Colloid ◽  
Target Organs ◽  
Aseptic Conditions ◽  
In Vitro Stability ◽  
Potential Use

Summary Aim: One therapeutic approach to rheumatoid arthritis and other inflammatory arthropathies besides surgical removal of inflamed synovium is radiation synovectomy using beta-emitting radionuclides to destroy the affected synovial tissue. Up to now the major problem associated with the use of labeled particles or colloids has been considerable leakage of radionuclides from the injected joint coupled with high radiation doses to liver and other non target organs. In this study we compared 188Re labeled hydroxyapatite particles and 188Re rhenium sulfur colloid for their potential use in radiation synovectomy. Methods: To this end we varied the labeling conditions (concentrations, pH-value, heating procedure) and analyzed the labeling yield, radiochemical purity, and in vitro stability of the resulting radiopharmaceutical. Results: After optimizing labeling conditions we achieved a labeling yield of more than 80% for 188Re hydroxyapatite and more than 90% for the rhenium sulfur colloid. Both of the radiopharmaceuticals can be prepared under aseptic conditions using an autoclav for heating without loss of activity. In vitro stability studies using various challenge solutions (water, normal saline, diluted synovial fluid) showed that 188Re labeled hydroxyapatite particles lost about 80% of their activity within 5 d in synovial fluid. Rhenium sulfur colloid on the other hand proved to be very stable with a remaining activity of more than 93% after 5 d in diluted synovial fluid. Conclusion: These in vitro results suggest that 188Re labeled rhenium sulfur colloid expects to be more suitable for therapeutic use in radiation synovectomy than the labeled hydroxyapatite particles.

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