Untargeted and targeted analysis of sarin poisoning biomarkers in rat urine by liquid chromatography and tandem mass spectrometry.

Chemical warfare agents continue to pose a real threat to humanity, despite their prohibition under the Chemical Weapons Convention. Sarin is one of the most toxic and lethal representatives of nerve agents. The methodology for the targeted analysis of known sarin metabolites has reached great heights, but little attention has been paid to the untargeted analysis of biological samples of victims exposed to this deadly poisonous substance. At present, the development of computational and statistical methods of analysis offers great opportunities for finding new metabolites or understanding the mechanisms of action or effect of toxic substances on the organism. This study presents the targeted LC-MS/MS determination of methylphosphonic acid and isopropyl methylphosphonic acid in the urine of rats exposed to a non-lethal dose of sarin, as well as the untarget urine analysis by LC-HRMS. Targeted analysis of polar acidic sarin metabolites was performed on a mixed-mode reversed-phase anion-exchange column, and untargeted analysis on a conventional reversed-phase C18 column. Isopropyl methylphosphonic acid was detected and quantified within 5 days after subcutaneous injection of sarin at a dose of 1/4 LD50. A combination of generalized additive mixed models and dose-response analysis with database searches using accurate mass of precursor ions and corresponding MS/MS spectra enabled us to propose new six potential biomarkers of biological response to exposure. The results confirm the well-known fact that sarin poisoning has a significant impact on the victims' metabolome, with inhibition of acetylcholinesterase being just the first step and trigger of the complex toxicodynamic response.

A novel strategy for isolation and determination of sugars and sugar alcohols from conifers.

The ultrasound-assisted extraction method for isolation of 17 sugars and sugar alcohols from conifers with a subsequent hydrophilic interaction liquid chromatography-tandem mass spectrometry method for their determination is proposed. The optimization of extraction parameters was carried out using Taguchi - L9 (34) orthogonal array experimental design for the following parameters-a methanol concentration in the extraction solution, an extraction time, a type of plant sample and an extraction temperature. The optimal ultrasound-assisted extraction conditions were-MeOH concentration - 30% (water - 70%), extraction time - 30 min, type of plant sample - II (grinded leaves 2-4 mm long), extraction temperature - 60 °C. Pure water and acetonitrile were used as eluents in gradient elution mode to separate the analytes. Direct determination of multiple sugars and sugar alcohols was carried out using a mass spectrometric detector operated in a multiple reaction monitoring mode, providing detection limits in the range between 0.1 and 20 ng/mL and good analytical characteristics of the method without derivatization. The developed approach was validated by multiple successive extraction method applied to test its performance on a series of 10 samples, i.e. 2 samples per each of 5 genera: Abies, Larix, Picea, Pinus (Pinaceae) and Juniperus (Cupressaceae), widely distributed in the boreal conifer forests of Eurasia. The novel strategy can be used for profiling of sugars and sugar alcohols in a wide range of plant species.

Hydrophilic interaction liquid chromatography-tandem mass spectrometry methylphosponic and alkyl methylphosphonic acids determination in environmental samples after pre-column derivatization with p-bromophenacyl bromide.

Once exposed to the environment organophosphate nerve agents readily degrade by rapid hydrolysis to the corresponding alkyl methylphosphonic acids which do not exist in nature. These alkyl methylphosphonic acids are finally slowly hydrolyzed to methylphosphonic acid. Methylphosphonic acid is the most stable hydrolysis product of organophosphate nerve agents, persisting in environment for a long time. A highly sensitive method of methylphosphonic acid and alkyl methylphosphonic acids detection in dust and ground mixed samples has been developed and validated. The fact that alkyl methylphosphonic acids unlike methylphosphonic acid did not react with p-bromophenacyl bromide under chosen conditions was discovered. This allowed simultaneous chromatographic separation and mass spectrometric detection of derivatized methylphosphonic acid and underivatized alkyl methylphosphonic acids using HILIC-MS/MS method. Very simple sample pretreatment with high recoveries for each analyte was developed. Methylphosphonic acid pre-column derivate and alkyl methylphosphonic acids were detected using tandem mass spectrometry with electrospray ionization after hydrophilic interaction liquid chromatography separation. The developed approach allows achieving ultra-low detection limits: 200 pg mL(-1) for methylphosphonic acid, 70 pg mL(-1) for ethyl methylphosphonic acid, 8 pg mL(-1) for i-propyl methylphosphonic acid, 8 pg mL(-1) for i-butyl methylphosphonic acid, 5 pg mL(-1) for pinacolyl methylphosphonic acid in the extracts of dust and ground mixed samples. This approach was successfully applied to the dust and ground mixed samples from decommissioned plant for the production of chemical weapons.

Health effects of a subway environment in healthy volunteers.

Environmental particle exposure, often estimated as the particulate mass of particles with a diameter <10 microm, <2.5 microm or <1 microm (PM(10), PM(2.5) or PM(1)), is known to have a negative impact on the health of the population. Little is known about how the size and origin of particles influence the effects. We have previously shown that exposure to a road tunnel environment causes a cellular inflammatory response in the airways of healthy individuals. In the present study, our aim was to investigate potential airway health effects from exposure to a subway environment. 20 healthy volunteers were exposed to a subway and a control environment for 2 h, followed by measurements of lung function and the inflammatory response in the lower airways (bronchoscopy) and in the peripheral blood. No cellular response was found in the airways after exposure to the subway environment. In the blood, we found a statistically significant increase in fibrinogen and regulatory T-cells expressing CD4/CD25/FOXP3. Subway and road tunnel environments have similar levels of PM(10) and PM(2.5), whilst the concentrations of ultrafine particles, nitrogen monoxide and dioxide are lower in the subway. Although no cellular response was detected, the findings indicate a biological response to the subway environment. Our studies show that using gravimetric estimates of ambient particulate air pollution alone may have clear limitations in health-risk assessment.

Birth weight and the risk of depressive disorder in late life.

BACKGROUND: Low birth weight is a risk factor for coronary heart disease, diabetes, stroke and hypertension. Depression is highly associated with these conditions. AIMS: To examine the association between birth weight and depression in late life. METHOD: A total of 882 singleton term births in the 1920s had contemporary records of birth weight and weight at 1 year. At 68 years all completed the Geriatric Depression Scale and 867 completed the Geriatric Mental State Examination. A logistic regression was used to analyse the associations between depression, birth weight and weight at 1 year while adjusting for known risk factors. RESULTS: Current social class, social class at birth, recent bereavement, social isolation and physical illness increased the risk of depression. After adjusting for these and weight at 1 year, the odds ratios for depression among men, but not women, rose incrementally with decreasing birth weight (1.0, 12.8; for continuous variable, P<0.007). CONCLUSIONS: Foetal undernutrition predisposes men to depression in late adult life. If replicated, these results would suggest a neurodevelopmental aetiology of depression, possibly mediated by programming of the hypothalamic-pituitary-adrenal axis.

[The experience of kidney transplantation at the Donetsk transplantation center]. / Opyt peresadki pochni v Donetskom transplantatsionnom tsentre.

In Donetskiy transplantational centre during the period from 1986 to 1996 yr were conducted 305 operations of the kidney transplantation from the cadaveric and living donor. Kidney transplantation permits to achieve higher level of rehabilitation than while application of hemodialysis and must become the method of choice in treatment of terminal stage of chronic renal insufficiency. Considering large demand for the organs transplantation in Ukraine it is necessary to create an economically substantiated programme "Transplantation of organs".

Effects of morning phototherapy on circadian markers in seasonal affective disorder.

BACKGROUND: The suppression of melatonin by light at 00.30 hours has been shown to be greater in winter than in summer on patients with seasonal affective disorder (SAD) but not in matched normal controls. METHOD: In this study 12 patients with SAD and 12 matched normal controls were exposed to morning light therapy in the winter. Melatonin profiles and sensitivity to light were measured before and after treatment. RESULTS: The SAD but not the normal group showed a phase advance of melatonin rhythms in response to phototherapy. There was an association between phase position and phase shift in the SAD but not in the normal group. CONCLUSIONS: There may be instability of circadian rhythms in SAD mediated by a high-amplitude phase response curve, rather than a fixed phase abnormality as had been previously suggested. This instability may be secondary to impaired serotoninergic function in the afferent pathways to the suprachiasmatic nuclei.

Effect of fluoxetine on melatonin in patients with seasonal affective disorder and matched controls.

BACKGROUND: The aim was to investigate the secretion profile of melatonin and seasonal affective disorder before and after treatment with fluoxetine. METHOD: A six-week case-controlled study with repeated overnight blood sampling was conducted. Ten patients fulfilling the criteria for major depressive disorder, seasonal type, with a 29-item Hamilton Depression Rating Scale (HDRS) score of at least 20 were compared with ten age- and sex-matched healthy controls in a clinical laboratory. The effects of fluoxetine (20 mg/day) on the HDRS and melatonin concentration were measured. RESULTS: Fluoxetine significantly reduced melatonin levels in both groups. There was no significant difference in melatonin secretion between the groups. CONCLUSIONS: The effect of fluoxetine differs from tricyclics and fluvoxamine, both of which increase melatonin.

[Effect of interferon inducers on the development of specific resistance to tick-borne encephalitis]. / Vliianie induktorov interferona na formirovanie spetsificheskoi rezistentnosti k kleshchevomu éntsefalitu

Various natural and synthetic interferon inducers stimulate postvaccination immunity to tick-borne encephalitis virus in mice. This capacity was found not only in macromolecular synthetic polyribonucleotides such as (poly I)-(poly C), (poly G)-(poly C), (poly A)-(poly U) and substances with much lower molecular weight such as copolymers of vinylpyrrolidone with maleic anhydride, crotonic acid or metacrylic acid but also in a low molecular interferon inducer tiloron. These and other interferon inducers examined (endotoxin S-typhi, statolon) exhibited no parallelism between the intensity of their stimulating effect of immunogenesis and levels of interferon production induced in mice and the associated resistance to tick-borne encephalitis. The results indicate a possibliity of using various interferon inducers for stimulation of post-vaccination immunity to tick-borne encephalitis.