Measurement of 87Sr/86Sr in limestones after acid leaching and direct injection in a liquid chromatograph coupled to Multicollector ICP-MS

A procedure for the measurement of 87Sr/86Sr in carbonates without off-line strontium separation was developed, validated and applied to Normandy chalkstones. The method is based on the injection of the...

The Correlation Between Children’s Acute Lymphoblastic Leukemia Drug Resistance System Induced by Metabolomics-Based 6-Mercaptopurine and Hypoxanthine-Guanine Phosphoribosyl Transferase 1 Protein

This study aimed to explore 6-mercaptopurine (MP)-induced children’s acute lymphoblastic leukemia (ALL) drug resistance system and leukemia hypoxanthine-guanine phosphoribosyl transferase 1 (HPRT1) protein. Based on metabonomics, drug resistance of 6MP-Reh cell line was established by increasing concentration administration method, and the degree of drug resistance of 6MP-Reh was verified by apoptosis test, western blotting (WB) test, and drug sensitivity test. The changes of tissue inhibitor of matrix metalloproteinase (TIMP) and thioguanosine monophosphate (TGMP) in drug-resistant cells were detected through liquid chromatograph (LC)/mass spectrometer (MS). The 6MP-Reh-wt cell line was established by lentivirus infection, so as to verify the correlation between HPRT1 and drug resistance mechanism. The results showed that the inhibition concentration (IC50) value, cell vitality (CV), apoptosis rate, and 6-MP content of 6MP-Reh were higher hugely than those of Reh (P < 0.05). The contents of HPRT1, TIMP, and TGMP in 6MP-Reh cells were lower sharply than the contents of Reh cells (P < 0.001). The IC50 value of 6MP-Reh-wt was also lower steeply than the value of 6MP-Reh (P < 0.001), and the concentrations of TIMP and TGMP increased obviously (P < 0.05). Therefore, it indicated that the mutation of HPRT1 in drugresistant cell lines could lead to a decrease in their viability and cause leukemia cells to develop resistance to 6-MP. In addition, HPRT1 gene could improve their resistance to 6-MP.

Comparative Study on the Phenolic Fingerprint and Antioxidant Activity of Strawberry Tree (Arbutus unedo L.) Leaves and Fruits

The strawberry tree (Arbutus unedo L., Ericaceae family) is an evergreen Mediterranean shrub whose leaves and fruits are used in traditional medicine due to their antioxidant, antimicrobial, antidiabetic, diuretic, and antiproliferative properties. The health benefits are mainly attributed to the presence of phenolic compounds. The aim of this study was to compare the phenolic profiles, total phenolic content (TPC), and radical scavenging activity (RSA) of A. unedo leaves and fruits collected at two locations in Croatia. Phenolic profiles were identified using an ultra-high-performance liquid chromatograph (UHPLC) coupled with a hybrid mass spectrometer (LTQ Orbitrap MS). TPC was determined by Folin–Ciocalteu’s assay, while RSA was investigated using DPPH reagent. A total of 64 phenolics (60 and 42 compounds in leaves and fruits, respectively) were identified. Hyperoside and flavan-3-ols were predominant compounds in leaves, while gallocatechin and catechin were the major compounds found in fruits. To the authors’ knowledge, 16 and 5 phenolics in leaves and fruits, respectively, were reported for the first time. Principal component analysis (PCA) showed that UHPLC-LTQ Orbitrap MS could be used to identify which phenolics were able to discriminate samples regarding plant tissue and geographical origin. TPC in leaves and fruits were in the ranges of 67.07–104.74 and 16.78–25.86 mg gallic acid equivalents (GAE)/g dried weight (dw), respectively. RSA for leaves and fruits were in the ranges of 408.92–430.98 and 74.30–104.04 μmol Trolox equivalents (TE)/g dw, respectively. The number of identified phenolics was lower in fruits compared to leaves. Such a large number of bioactive phenolics identified and the strong antioxidant activity pointed to A. unedo as a promising health-promoting plant and natural food preservative.

Simultaneous Determination of Four Marker Compounds in Lobelia chinensis Lour. Extract by HPLC-PDA

Lobelia chinensis Lour. (L. chinensis) has traditionally been used as a treatment for snake bites, high fever, jaundice, edema, and diarrhea, and modern studies have reported its anti-inflammatory, antioxidant, and antiviral activities. L. chinensis contains various compounds, such as flavonoids and coumarins, and its flavonoid components have been identified in many studies. In this study, a high-performance liquid chromatograph equipped with a photodiode array (PDA) detector and an Aegispak C18-L reverse-phase column (4.6 mm × 250 mm i.d., 5 μm) was used to simultaneously analyze four marker components in L. chinensis for standardization purposes. HPLC-PDA (detection at 340 nm), performed using a 0.1% formic acid-water/0.1% formic acid-acetonitrile gradient, separated the four marker compounds: luteolin-7-O-β-d-glucuronopyranosyl (1→2)-O-β-d-glucuronopyranoside, clerodendrin, chrysoeriol-7-O-diglucuronide, and diosmin. The developed analytical method showed excellent linearity values (r2 > 0.9991), limits of detection (LODs: 0.376–2.152 μg/mL), limits of quantification (LOQs: 1.147–6.521 μg/mL), intra- and inter-day precisions (RSD < 1.96%), and analyte recoveries (96.83–127.07%; RSD < 1.73%); thus, it was found to be suitable for the simultaneous analysis of these four marker compounds in L. chinensis.

Revealing and identification of isoniazid metabolites in beef meat in case of poisoning of service dogs

Relevance. Every year, dog breeders are faced with the problem of acute poisoning of dogs. Various toxic compounds can be the cause of dog poisoning. The huge variety of potentially toxic substances makes it difficult to identify the source of poisoning. Service dog breeding also faces this problem, as a result of which it is necessary to have information about the possibility of poisoning service dogs, as well as methods for detecting toxic substances and preventing further poisoning. In service dog breeding, they mainly use feed made by cooking gruel soup in boilers in the feed kitchens of nurseries. Due to the fact that there were cases of poisoning of service dogs in the Vyborg district of the Leningrad region, we conducted research to identify toxic compounds in beef from which feed was made in the feed kitchens of nurseries.Methods. The studies were carried out at the Institute of Toxicology of the Federal Medical and Biological Agency using an Acguity UPLC I-class ultra-performance liquid chromatograph with a spectrophotometric detecto and an Acguity UPLC H-class ultraperformance liquid chromatograph with a Xevo TQD tandem mass spectrometer. Sample components were identified by electronic spectra and mass numbers.Results. According to the results of the study, the presence of isoniazid metabolic products in the form of isonicatinic acid, as well as conjugates of isoniazid with sulfuric, acetic and glucuronic acids, was found in beef meat.The obtained results of the study of the chromatographic profiles of aqueous extracts and the chemical identification of their components in the products that are used for the preparation of food for service dogs make it possible to accurately determine and identify toxic substances with a wide variety of them. Thus, in order to prevent the loss of service dogs, it is necessary to control the newly received food and feed in order to prevent poisoning.

Liquid Chromatograph-Mass Spectrometry-Based Non-targeted Metabolomics Discovery of Potential Endogenous Biomarkers Associated With Prostatitis Rats to Reveal the Effects of Magnoflorine

Magnoflorine (Mag) has multiple pharmacological activities for the prevention and treatment of prostatitis. However, its molecular mechanisms andpharmacological targets are not clear. In this study, the ultra-performance liquid tandem mass spectrometry-based metabolomics method was used to clarify the intervention of Mag against prostatitis and the biological mechanism. A total of 25 biomarkers associated with the prostatitis model were identified by metabolomics, and a number of metabolic pathways closely related to the model were obtained by MetPA analysis. After given Mag treatment, the results of each indicator were shown that Mag alkaloid could inhibit the development of prostatitis effectively. We found that Mag had regulative effects on potential biomarkers of prostatitis model, which can regulate them to the control group. Our results indicated that alkaloids have an effective intervention therapy for prostatitis, and five types of metabolic pathways closely related to prostatitis model were obtained, including phenylalanine, tyrosine and tryptophan biosynthesis, phenylalanine metabolism, tyrosine metabolism, arginine and proline metabolism, glycine, serine and threonine metabolism, alanine, aspartate and glutamate metabolism. This study has provided the basic experimental data for the development of Mag in the prevention and treatment of prostatitis.

Plasma Lipidomics Identifies Unique Lipid Signatures and Potential Biomarkers for Patients With Aortic Dissection

Aortic dissection (AD) is a catastrophic cardiovascular emergency with a poor prognosis, and little preceding symptoms. Abnormal lipid metabolism is closely related to the pathogenesis of AD. However, comprehensive lipid alterations related to AD pathogenesis remain unclear. Moreover, there is an urgent need for new or better biomarkers for improved risk assessment and surveillance of AD. Therefore, an untargeted lipidomic approach based on ultra-high-performance liquid chromatograph-mass spectrometry was employed to unveil plasma lipidomic alterations and potential biomarkers for AD patients in this study. We found that 278 of 439 identified lipid species were significantly altered in AD patients (n = 35) compared to normal controls (n = 32). Notably, most lipid species, including fatty acids, acylcarnitines, cholesteryl ester, ceramides, hexosylceramides, sphingomyelins, lysophosphatidylcholines, lysophosphatidylethanolamines, phosphatidylcholines, phosphatidylinositols, diacylglycerols, and triacylglycerols with total acyl chain carbon number ≥54 and/or total double bond number ≥4 were decreased, whereas phosphatidylethanolamines and triacylglycerols with total double bond number &lt;4 accumulated in AD patients. Besides, the length and unsaturation of acyl chains in triacylglycerols and unsaturation of 1-acyl chain in phosphatidylethanolamines were decreased in AD patients. Moreover, lysophosphatidylcholines were the lipids with the largest alterations, at the center of correlation networks of lipid alterations, and had excellent performances in identifying AD patients. The area under the curve of 1.0 and accuracy rate of 100% could be easily obtained by lysophosphatidylcholine (20:0/0:0) or its combination with lysophosphatidylcholine (17:0/0:0) or lysophosphatidylcholine (20:1/0:0). This study provides novel and comprehensive plasma lipidomic signatures of AD patients, identifies lysophosphatidylcholines as excellent potential biomarkers, and would be beneficial to the pathogenetic study, risk assessment and timely diagnosis and treatment of AD.

TTPAL promotes gastric tumorigenesis by directly targeting NNMT to activate PI3K/AKT signaling

Copy number alterations are crucial for gastric cancer (GC) development. In this study, Tocopherol alpha transfer protein-like (TTPAL) was identified to be highly amplified in our primary GC cohort (30/86). Multivariate analysis showed that high TTPAL expression was correlated with the poor prognosis of GC patients. Ectopic expression of TTPAL promoted GC cell proliferation, migration, and invasion in vitro and promoted murine xenograft tumor growth and lung metastasis in vivo. Conversely, silencing of TTPAL exerted significantly opposite effects in vitro. Moreover, RNA-sequencing and co-immunoprecipitation (Co-IP) followed by liquid chromatograph-mass spectrometry (LC-MS) identified that TTPAL exerted oncogenic functions via the interaction of Nicotinamide-N-methyl transferase (NNMT) and activated PI3K/AKT signaling pathway. Collectively, TTPAL plays a pivotal oncogenic role in gastric carcinogenesis through promoting PI3K/AKT pathway via cooperating with NNMT. TTPAL may serve as a prognostic biomarker of patients with GC.

Determination of uric acid in grain using HPLC

В данной статье показана возможность улучшения определения мочевой кислоты методом высокоэффективной жидкостной хроматографии (ВЭЖХ), с помощью увеличения растворимости ее в 1 %-ном растворе ацетата натрия, повышения удержания мочевой кислоты и тем самым изменения времени выхода, что позволяет повысить точность анализа. Проведено сравнение градуировочных растворов и опытных образцов зерна зараженных вредителями хлебных запасов. В процессе исследования был опробован метод для определения и идентификации мочевой кислоты как одного из загрязняющих зерно веществ с помощью ВЭЖХ в обращенной фазе. Экспериментально опробована и усовершенствована методика анализа мочевой кислоты в зерне с использованием жидкостного хроматографа «Стайер». Описаны оборудование и материалы для ВЭЖХ, условия хроматографического разделения и детектирования, построения калибровочного графика, экстракции, включая методику экстракции, сходимости результатов при экстракции и введении экстракта в хроматограф, а также порядок и расчет измерений. Экспериментально показано, что усовершенствованная методика с применением ВЭЖХ позволяет использовать ее для проведения дальнейших исследований зависимости содержания мочевой кислоты от величины загрязнения зерна насекомыми. This article shows the possibility of improving the determination of uric acid by high-performance liquid chromatography (HPLC), by increasing its solubility in a 1 % solution of sodium acetate, increasing the retention of uric acid, and thereby changing the yield time, which allow to improve the accuracy of the analysis, a comparison of calibration solutions and experimental grain samples of pest-infected bread stocks have been carried out. During the research course a method for the determination and identification of uric acid has been tested as one of the grain polluting substance using HPLC in the reversed phase. The method of uric acid in grain analysis using a liquid chromatograph «Stayer» has been experimentally tested and improved. The equipment and materials for HPLC, the conditions of chromatographic separation and detection, the construction of a calibration graph, extraction, including the extraction method, the convergence of the results during extraction and the introduction of the extract into the chromatograph, as well as the course and calculation of measurements have been described. It has been experimentally shown that the improved method with HPLC allows to use it for further research of the uric acid content dependence on the amount of grain contamination by insects.

Laboratory evaluation of twelve portable devices for medicine quality screening

Background Post-market surveillance is a key regulatory function to prevent substandard and falsified (SF) medicines from being consumed by patients. Field deployable technologies offer the potential for rapid objective screening for SF medicines. Methods and findings We evaluated twelve devices: three near infrared spectrometers (MicroPHAZIR RX, NIR-S-G1, Neospectra 2.5), two Raman spectrometers (Progeny, TruScan RM), one mid-infrared spectrometer (4500a), one disposable colorimetric assay (Paper Analytical Devices, PAD), one disposable immunoassay (Rapid Diagnostic Test, RDT), one portable liquid chromatograph (C-Vue), one microfluidic system (PharmaChk), one mass spectrometer (QDa), and one thin layer chromatography kit (GPHF-Minilab). Each device was tested with a series of field collected medicines (FCM) along with simulated medicines (SIM) formulated in a laboratory. The FCM and SIM ranged from samples with good quality active pharmaceutical ingredient (API) concentrations, reduced concentrations of API (80% and 50% of the API), no API, and the wrong API. All the devices had high sensitivities (91.5 to 100.0%) detecting medicines with no API or the wrong API. However, the sensitivities of each device towards samples with 50% and 80% API varied greatly, from 0% to 100%. The infrared and Raman spectrometers had variable sensitivities for detecting samples with 50% and 80% API (from 5.6% to 50.0%). The devices with the ability to quantitate API (C-Vue, PharmaChk, QDa) had sensitivities ranging from 91.7% to 100% to detect all poor quality samples. The specificity was lower for the quantitative C-Vue, PharmaChk, & QDa (50.0% to 91.7%) than for all the other devices in this study (95.5% to 100%). Conclusions The twelve devices evaluated could detect medicines with the wrong or none of the APIs, consistent with falsified medicines, with high accuracy. However, API quantitation to detect formulations similar to those commonly found in substandards proved more difficult, requiring further technological innovation.