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1.
Tidsskr Nor Laegeforen ; 144(4)2024 Mar 19.
Article in Norwegian | MEDLINE | ID: mdl-38506014

ABSTRACT

Background: The knowledge base on new psychoactive substances (NPS) is generally limited. This introduces new challenges and increased unpredictability in substance abuse treatment. Case presentation: A man in his thirties was submitted to detoxification after reportedly using flubromazolam, a high potency designer benzodiazepine, which he had purchased on the dark web. Extensive drug testing of serum, urine and hair, and the remains in a dropper bottle delivered by the patient, did not reveal flubromazolam or possible metabolites, but did reveal several common drugs of abuse, and 8-aminoclonazolam, a metabolite of clonazolam, another designer benzodiazepine sold on the dark web. The detoxification was uncomplicated. An excessive treatment protocol based on the patient's information, involving high preparedness and increased resources, both clinically and analytically, turned out to be unnecessary. Interpretation: The drug use and clinical course in this case proved to be more common than the unit prepared for. The case history illustrates both the challenges with users of NPS and the general unpredictability in substance abuse treatment.


Subject(s)
Designer Drugs , Substance-Related Disorders , Male , Humans , Benzodiazepines/adverse effects , Substance Abuse Detection/methods , Psychotropic Drugs
2.
Forensic Sci Int ; 347: 111680, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37062138

ABSTRACT

Rocuronium is a neuromuscular blocking agent mainly used in anesthetic procedures. Two patients who died 53 and 76 days, respectively, after their last rocuronium exposure had low (0.002-0.007 mg/L) levels of the drug in femoral blood, urine and vitreous humor samples obtained at autopsy. In neither case, the cause of death was related to the exposure to rocuronium. Here, these two cases are presented and the implications of the findings discussed.


Subject(s)
Neuromuscular Blocking Agents , Neuromuscular Nondepolarizing Agents , Humans , Rocuronium , Neuromuscular Nondepolarizing Agents/adverse effects , Androstanols/adverse effects
3.
Nat Commun ; 13(1): 880, 2022 02 15.
Article in English | MEDLINE | ID: mdl-35169118

ABSTRACT

The impacts of enhanced nitrogen (N) deposition on the global forest carbon (C) sink and other ecosystem services may depend on whether N is deposited in reduced (mainly as ammonium) or oxidized forms (mainly as nitrate) and the subsequent fate of each. However, the fates of the two key reactive N forms and their contributions to forest C sinks are unclear. Here, we analyze results from 13 ecosystem-scale paired 15N-labelling experiments in temperate, subtropical, and tropical forests. Results show that total ecosystem N retention is similar for ammonium and nitrate, but plants take up more labelled nitrate ([Formula: see text]%) ([Formula: see text]) than ammonium ([Formula: see text]%) while soils retain more ammonium ([Formula: see text]%) than nitrate ([Formula: see text]%). We estimate that the N deposition-induced C sink in forests in the 2010s  is [Formula: see text] Pg C yr-1, higher than previous estimates because of a larger role for oxidized N and greater rates of global N deposition.


Subject(s)
Ammonium Compounds/analysis , Carbon Sequestration/physiology , Environmental Restoration and Remediation , Forests , Nitrates/analysis , Trees/metabolism , Environment , Nitrogen Isotopes/chemistry , Nitrogen Oxides/analysis , Soil/chemistry
4.
Glob Chang Biol ; 28(4): 1529-1543, 2022 02.
Article in English | MEDLINE | ID: mdl-34800306

ABSTRACT

The responses of forests to nitrogen (N) deposition largely depend on the fates of deposited N within the ecosystem. Nitrogen-fixing legume trees widely occur in terrestrial forests, but the fates of deposited N in legume-dominated forests remain unclear, which limit a global evaluation of N deposition impacts and feedbacks on carbon sequestration. Here, we performed the first ecosystem-scale 15 N labeling experiment in a typical legume-dominated forest as well as in a nearby non-legume forest to determine the fates of N deposition between two different forest types and to explore their underlying mechanisms. The 15 N was sprayed bimonthly for 1 year to the forest floor in control and N addition (50 kg N ha-1  year-1 for 10 years) plots in both forests. We unexpectedly found a strong capacity of the legume forest to retain deposited N, with 75 ± 5% labeled N recovered in plants and soils, which was higher than that in the non-legume forest (56 ± 4%). The higher 15 N recovery in legume forest was mainly driven by uptake by the legume trees, in which 15 N recovery was approximately 15% more than that in the nearby non-legume trees. This indicates higher N-demand by the legume than non-legume trees. Mineral soil was the major sink for deposited N, with 39 ± 4% and 34 ± 3% labeled N retained in the legume and non-legume forests, respectively. Moreover, N addition did not significantly change the 15 N recovery patterns of both forests. Overall, these findings indicate that legume-dominated forests act as a strong sink for deposited N regardless of high soil N availability under long-term atmospheric N deposition, which suggest a necessity to incorporate legume-dominated forests into N-cycling models of Earth systems to improve the understanding and prediction of terrestrial N budgets and the global N deposition effects.


Subject(s)
Fabaceae , Nitrogen , Ecosystem , Forests , Soil , Trees/physiology
5.
Basic Clin Pharmacol Toxicol ; 130(3): 415-422, 2022 Mar.
Article in English | MEDLINE | ID: mdl-34964262

ABSTRACT

BACKGROUND AND OBJECTIVES: Metformin is used to treat gestational diabetes. It is also used to treat women with polycystic ovary syndrome and has been shown to prevent late miscarriage and preterm birth. However, increased renal clearance during pregnancy causes a decline in serum concentrations of metformin. The aim of this study was to explore the time course of the pregnancy-related changes in metformin pharmacokinetics and the return to the non-pregnant state. METHOD: A subgroup of women in the PregMet2 study (n = 73) agreed to provide serum samples at three time-points in pregnancy (gestational weeks 19, 28 and 32) and once in post partum, (either 2, 4 or 8 weeks after delivery). Serum metformin concentrations were compared using a four-parameter logistic model. FINDINGS: The mean steady-state serum concentration of metformin during pregnancy was 9.39 µmoL/L, whereas the post partum concentration was 12.36 µmoL/L, an increase of 32% (p = 0,019). This change took place already during the first 2 weeks post partum. CONCLUSION: Clinicians who treat pregnant women with metformin should be aware of the significant decrease in metformin concentration mediated by pregnancy, and the rapid increase after delivery, as it may impact both the therapeutic efficacy and the risk of adverse drug reactions.


Subject(s)
Abortion, Spontaneous , Metformin , Polycystic Ovary Syndrome , Premature Birth , Abortion, Spontaneous/chemically induced , Female , Humans , Hypoglycemic Agents/adverse effects , Hypoglycemic Agents/pharmacokinetics , Infant, Newborn , Metformin/adverse effects , Polycystic Ovary Syndrome/drug therapy , Pregnancy
6.
Sci Total Environ ; 798: 149306, 2021 Dec 01.
Article in English | MEDLINE | ID: mdl-34340072

ABSTRACT

Human activities have disturbed global phosphorus (P) cycling by introducing substantial amounts of P to natural ecosystems. Although natural P gradients and fertilization studies have found that plant community traits are closely related to P availability, it remains unclear how increased P supply affects plant growth and diversity in P-deficient tropical forests. We used a decadal P-addition experiment (2007-2017) to study the effects of increased P input on plant growth and diversity in understory layer in tropical forests. We monitored the dynamics of seedling growth, survival rate, and diversity of understory plants throughout the fertilization period under control and P addition at 15 g P m-2 yr-1. To identify the drivers of responses, P concentration, photosynthesis rate and nonstructural carbon were analyzed. Results showed that long-term P addition significantly increased P concentrations both in soil pools and plant tissues. However, P addition did not increase the light-saturated photosynthesis rate or growth rate of the understory plants. Furthermore, P addition significantly decreased the survival rate of seedlings and reduced the species richness and density of understory plants. The negative effects of P addition may be attributed to an increased carbon cost due to the tissue maintenance of plants with higher P concentrations. These findings indicate that increased P supply alone is not necessary to benefit the growth of plants in ecosystems with low P availability, and P inputs can inhibit understory plants and may alter community composition. Therefore, we appeal to a need for caution when inputting P to tropical forests ecosystems.


Subject(s)
Ecosystem , Phosphorus , Forests , Humans , Plants , Soil , Trees , Tropical Climate
8.
Glob Chang Biol ; 27(10): 2076-2087, 2021 May.
Article in English | MEDLINE | ID: mdl-33484031

ABSTRACT

The effects of nitrogen (N) deposition on forests largely depend on its fate after entering the ecosystem. While several studies have addressed the forest fate of N deposition using 15 N tracers, the long-term fate and redistribution of deposited N in tropical forests remains unknown. Here, we applied 15 N tracers to examine the fates of deposited ammonium ( NH 4 + ) and nitrate ( NO 3 - ) separately over 3 years in a primary and a secondary tropical montane forest in southern China. Three months after 15 N tracer addition, over 60% of 15 N was retained in the forests studied. Total ecosystem retention did not change over the study period, but between 3 months and 3 years following deposition 15 N recovery in plants increased from 10% to 19% and 13% to 22% in the primary and secondary forests, respectively, while 15 N recovery in the organic soil declined from 16% to 2% and 9% to 2%. Mineral soil retained 50% and 35% of 15 N in the primary and secondary forests, with retention being stable over time. The total ecosystem retention of the two N forms did not differ significantly, but plants retained more 15 NO 3 - than 15 NH 4 + and the organic soil more 15 NH 4 + than NO 3 - . Mineral soil did not differ in 15 NH 4 + and 15 NO 3 - retention. Compared to temperate forests, proportionally more 15 N was distributed to mineral soil and plants in these tropical forests. Overall, our results suggest that atmospherically deposited NH 4 + and NO 3 - is rapidly lost in the short term (months) but thereafter securely retained within the ecosystem, with retained N becoming redistributed to plants and mineral soil from the organic soil. This long-term N retention may benefit tropical montane forest growth and enhance ecosystem carbon sequestration.


Subject(s)
Ecosystem , Nitrogen , China , Forests , Soil , Trees
9.
Forensic Sci Int ; 311: 110274, 2020 Jun.
Article in English | MEDLINE | ID: mdl-32302877

ABSTRACT

The introduction of new psychoactive substances (NPS) on the illicit drug market has led to major challenges for the analytical laboratories. Keeping screening methods up to date with all relevant drugs is hard to achieve and the risk of missing important findings in biological samples is a matter of concern. Aiming for an extended retrospective data analysis, diagnostic fragment ions from synthetic cannabinoids (n=251), synthetic opioids (n=88) and designer benzodiazepines (n=26) not included in our original analytical method were obtained from the crowdsourced database HighResNPS.com and converted to a personalized library in a format compatible with the analytical instrumentation. Data files from the analysis of 1314 forensic post mortem samples with an Agilent 6540 ultra high pressure liquid chromatography quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) performed in our laboratory from January 2014 to December 2018 were retrieved and retrospectively processed with the new personalized library. Potentially positive findings were grouped in two: The most confident findings contained MS/MS data for library match (category 1) whereas the less confident findings lacked such data (category 2). Five new category 1 findings were identified: Flubromazepam in two data files from 2015 and 2016, respectively, phenibut (4-amino-3-phenylbutyric acid) in one data file from 2015, fluorofentanyl in one data file from 2016 and cyclopropylfentanyl in one data file from 2018. Retention time matches with reference standards further strengthened these findings. A list of 35 presumably positive category 2 findings was generated. Of these, only one finding of phenibut was considered plausible after checking retention times and signal-to-noise ratios. This study shows that new compounds can be detected retrospectively in data files from QTOF-MS using an updated library containing diagnostic fragment ions. Automatic screening procedures can be useful, but a manual re-evaluation of positive findings will always be necessary.


Subject(s)
Analgesics, Opioid/analysis , Benzodiazepines/analysis , Cannabinoids/analysis , Designer Drugs/analysis , Synthetic Drugs/analysis , Chromatography, High Pressure Liquid/methods , Forensic Toxicology , Humans , Illicit Drugs/analysis , Mass Spectrometry , Retrospective Studies , Substance Abuse Detection
10.
J Anal Toxicol ; 44(2): 140-148, 2020 Mar 07.
Article in English | MEDLINE | ID: mdl-31788682

ABSTRACT

New psychoactive substances are emerging on the illegal drug market. Synthetic opioids including fentanyl analogues are of special concern due to their high potency. This indicates the possibility of low drug concentrations in vivo and calls for sensitive analytical methods and identification of the most appropriate analytical targets. In this study the in vitro metabolism of ortho-, meta- and para-fluorofentanyl, three fluorinated derivatives of fentanyl, has been investigated using human hepatocytes and compared to the results from an authentic human urine sample. Based on knowledge on the metabolism of similar fentanyl analogues N-dealkylation and hydroxylation was hypothesized to be the most central pathways. The three fluorofentanyl isomers were incubated with pooled human hepatocytes at 1, 3 and 5 h. Liquid chromatography quadrupole time of flight mass spectrometry operating in data-dependent mode was used to analyse the hepatocyte samples, as well as the hydrolysed and non-hydrolysed authentic urine sample. Data were analysed by a targeted approach with a database of potential metabolites. The major metabolite formed in vitro was the N-dealkylation product norfluorofentanyl. In addition various hydroxylated metabolites, a N-oxide, dihydrodiol metabolites and a hydroxymethoxy metabolite were found. In total, 14 different metabolites were identified for each fluorofentanyl isomer. In the authentic urine sample, three metabolites were detected in addition to the ortho-fluorofentanyl parent compound, with hydroxymethoxy metabolite having the highest abundance followed by norfluorofentanyl and a metabolite hydroxylated on the ethylphenyl ring. This in vitro study showed that the metabolic pattern for ortho-, meta-, and para-fluorofentanyl was close to those previously reported for other fentanyl analogues. We suggest that the hydroxymethoxy metabolite and the metabolite hydroxylated on the ethylphenyl ring should be the metabolites primarily investigated in further studies to determine the most appropriate marker for intake of fluorofentanyl derivatives in urine drug screening for human subjects.


Subject(s)
Fentanyl/metabolism , Hepatocytes/metabolism , Illicit Drugs/metabolism , Substance Abuse Detection , Analgesics, Opioid , Chromatography, Liquid , Designer Drugs , Fentanyl/analogs & derivatives , Fentanyl/chemistry , Humans , Hydrolysis , Hydroxylation , Illicit Drugs/chemistry , Mass Spectrometry , Microsomes, Liver
11.
Ecol Appl ; 29(6): e01920, 2019 09.
Article in English | MEDLINE | ID: mdl-31058370

ABSTRACT

The impacts of anthropogenic nitrogen (N) deposition on forest ecosystems depend in large part on its fate. However, our understanding of the fates of different forms of deposited N as well as the redistribution over time within different ecosystems is limited. In this study, we used the 15 N-tracer method to investigate both the short-term (1 week to 3 months) and long-term (1-3 yr) fates of deposited NH4+ or NO3- by following the recovery of the 15 N in different ecosystem compartments in a larch plantation forest and a mixed forest located in northeastern China. The results showed similar total ecosystem retention for deposited NH4+ and NO3- , but their distribution within the ecosystems (plants vs. soil) differed distinctly particularly in the short-term, with higher 15 NO3- recoveries in plants (while lower recoveries in organic layer) than found for 15 NH4+ . The different short-term fate was likely related to the higher mobility of 15 NO3- than 15 NH4+ in soils instead of plant uptake preferences for NO3- over NH4+ . In the long-term, differences between N forms became less prevalent but higher recoveries in trees (particularly in the larch forest) of 15 NO3- than 15 NH4+ tracer persisted, suggesting that incoming NO3- may contribute more to plant biomass increment and forest carbon sequestration than incoming NH4+ . Differences between the two forests in recoveries were largely driven by a higher 15 N recovery in the organic layer (both N forms) and in trees (for 15 NO3- ) in the larch forest compared to the mixed forest. This was due to a more abundant organic layer and possibly higher tree N demand in the larch forest than in the mixed forest. Leachate 15 N loss was minor (<1% of the added 15 N) for both N forms and in both forests. Total 15 N recovery averaged 78% in the short-term and decreased to 55% in the long-term but with increasing amount of 15 N label (re)-redistributed into slow turn-over pools (e.g., trees and mineral soil). The different retention dynamics of deposited NH4+ and NO3- may have implications in environmental policy related to the anthropogenic emissions of the two N forms.


Subject(s)
Ecosystem , Forests , China , Nitrogen , Soil , Trees
12.
Ecosystems ; 22(2): 379-400, 2019.
Article in English | MEDLINE | ID: mdl-30956544

ABSTRACT

Nitrogen (N) inputs from atmospheric deposition can increase soil organic carbon (SOC) storage in temperate and boreal forests, thereby mitigating the adverse effects of anthropogenic CO2 emissions on global climate. However, direct evidence of N-induced SOC sequestration from low-dose, long-term N addition experiments (that is, addition of < 50 kg N ha-1 y-1 for > 10 years) is scarce worldwide and virtually absent for European temperate forests. Here, we examine how tree growth, fine roots, physicochemical soil properties as well as pools of SOC and soil total N responded to 20 years of regular, low-dose N addition in two European coniferous forests in Switzerland and Denmark. At the Swiss site, the addition of 22 kg N ha-1 y-1 (or 1.3 times throughfall deposition) stimulated tree growth, but decreased soil pH and exchangeable calcium. At the Danish site, the addition of 35 kg N ha-1 y-1 (1.5 times throughfall deposition) impaired tree growth, increased fine root biomass and led to an accumulation of N in several belowground pools. At both sites, elevated N inputs increased SOC pools in the moderately decomposed organic horizons, but decreased them in the mineral topsoil. Hence, long-term N addition led to a vertical redistribution of SOC pools, whereas overall SOC storage within 30 cm depth was unaffected. Our results imply that an N-induced shift of SOC from older, mineral-associated pools to younger, unprotected pools might foster the vulnerability of SOC in temperate coniferous forest soils.

13.
New Phytol ; 223(1): 33-39, 2019 07.
Article in English | MEDLINE | ID: mdl-30636276

ABSTRACT

The extent to which ectomycorrhizal (ECM) fungi enable plants to access organic nitrogen (N) bound in soil organic matter (SOM) and transfer this growth-limiting nutrient to their plant host, has important implications for our understanding of plant-fungal interactions, and the cycling and storage of carbon (C) and N in terrestrial ecosystems. Empirical evidence currently supports a range of perspectives, suggesting that ECM vary in their ability to provide their host with N bound in SOM, and that this capacity can both positively and negatively influence soil C storage. To help resolve the multiplicity of observations, we gathered a group of researchers to explore the role of ECM fungi in soil C dynamics, and propose new directions that hold promise to resolve competing hypotheses and contrasting observations. In this Viewpoint, we summarize these deliberations and identify areas of inquiry that hold promise for increasing our understanding of these fundamental and widespread plant symbionts and their role in ecosystem-level biogeochemistry.


Subject(s)
Carbon/metabolism , Mycorrhizae/physiology , Soil Microbiology , Soil/chemistry , Nitrogen/metabolism , Phylogeny
14.
Drug Test Anal ; 11(1): 51-67, 2019 Jan.
Article in English | MEDLINE | ID: mdl-29996011

ABSTRACT

Synthetic cannabinoids are one of the most significant groups within the category new psychoactive substances (NPS) and in recent years new compounds have continuously been introduced to the market of recreational drugs. A sensitive and quantitative screening method in urine with metabolites of frequently seized compounds in Norway (AB-FUBINACA, AB-PINACA, AB-CHMINACA, AM-2201, AKB48, 5F-AKB48, BB-22, JWH-018, JWH-073, JWH-081, JWH-122, JWH-203, JWH-250, PB-22, 5F-PB-22, RCS-4, THJ-2201, and UR-144) using ultra-high pressure liquid chromatography-quadrupole time of flight-mass spectrometry (UHPLC-QTOF-MS) has been developed. The samples were treated with ß-glucuronidase prior to extraction and solid-phase extraction was used. Liquid handling was automated using a robot. Chromatographic separation was achieved using a C18-column and a gradient of water and acetonitrile, both with 0.1% formic acid. Each sample was initially screened for identification and quantification followed by a second injection for confirmation. The concentrations by which the compounds could be confirmed varied between 0.1 and 12 ng/mL. Overall the validation showed that the method fulfilled the set criteria and requirements for matrix effect, extraction recovery, linearity, precision, accuracy, specificity, and stability. One thousand urine samples from subjects in drug withdrawal programs were analyzed using the presented method. The metabolite AB-FUBINACA M3, hydroxylated metabolite of 5F-AKB48, hydroxylated metabolite of AKB48, AKB48 N-pentanoic acid, 5F-PB-22 3-carboxyindole, BB-22 3-carboxyindole, JWH-018 N-(5-hydroxypentyl), JWH-018 N-pentanoic acid, and JWH-073 N-butanoic acid were quantified and confirmed in 2.3% of the samples. The method was proven to be sensitive, selective and robust for routine use for the investigated metabolites.


Subject(s)
Cannabinoids/chemistry , Cannabinoids/urine , Illicit Drugs/chemistry , Illicit Drugs/urine , Substance Abuse Detection/methods , Tandem Mass Spectrometry/methods , Chromatography, High Pressure Liquid/methods , Chromatography, High Pressure Liquid/standards , Humans , Retrospective Studies , Substance Abuse Detection/standards , Tandem Mass Spectrometry/standards
15.
Acta Oncol ; 57(10): 1392-1400, 2018 Oct.
Article in English | MEDLINE | ID: mdl-29775128

ABSTRACT

BACKGROUND: The long-term toxicities after cisplatin-based chemotherapy (CBCT) reveal a remarkable inter-individual variation among testicular cancer survivors (TCSs). Therefore, we assessed long-term platinum (Pt) changes and their associations with CBCT-related late effects in TCSs. MATERIAL AND METHODS: In 77 TCSs treated with CBCT from 1984 to 1990, blood samples for analyses of Pt and a questionnaire including self-reported neuro- and ototoxicity (NTX) symptoms were collected during two follow-up surveys at median 12 (Survey I; SI) and 20 (Survey II; SII) years after treatment. Information about second cancers after SII was retrieved from the Norwegian Cancer Registry. RESULTS: A larger Pt decline from SI to SII was associated with a decreased risk of a second cancer diagnosis (HR 0.78, 95% CI 0.62-0.99 per 10 ng/L/year), and worsening of paresthesias in hands (OR 1.98, 95% CI 1.09-3.59 per 10 ng/L/year) and tinnitus (OR 1.51, 95% CI 1.01-2.27 per 10 ng/L/year). CONCLUSION: In summary, we found a significant association between a larger Pt decline and a reduced risk of second cancers and deterioration of paresthesias in hands and tinnitus.


Subject(s)
Antineoplastic Agents/adverse effects , Cancer Survivors , Cisplatin/adverse effects , Platinum/blood , Testicular Neoplasms/drug therapy , Adolescent , Adult , Aged , Cisplatin/pharmacokinetics , Hearing Loss/chemically induced , Humans , Logistic Models , Longitudinal Studies , Male , Middle Aged , Testicular Neoplasms/metabolism , Testicular Neoplasms/mortality , Young Adult
16.
Article in English | MEDLINE | ID: mdl-29783197

ABSTRACT

BACKGROUND: Poor drug adherence in hypertensive patients can lead to treatment failure and increased cardiovascular morbidity, as well as increased costs to society. An analytical method based on ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MSMS) was developed and validated for use in routine therapeutic drug monitoring (TDM). The method includes 21 antihypertensive drugs or active metabolites from the groups beta blockers (n=5), calcium antagonists (n=5), angiotensin II receptor antagonists (n=4), angiotensin converting enzyme (ACE) inhibitors (n=3) and diuretics (n = 3), in addition to one α1-selective alpha blocker. METHOD: A 200 µL serum sample was handled automatically using a pipetting robot. Protein precipitation was performed with 600 µL of 1% formic acid in acetonitrile (v:v) and phospholipid removal was carried out using a Waters OSTRO™ 96-well plate. After evaporation and reconstitution the eluent was injected thrice with different inlet and mass spectrometric methods to cover the different physico-chemical properties of the drugs and the variations in therapeutic concentration ranges between drugs. Acquity UPLC BEH C18 (2.1x50mm, 1.7 µm) column equipped with a corresponding pre-column was used for chromatographic separation. For every analyte an isotopically labelled analogue served as internal standard, except for lisinopril where enalaprilat-d5 was used. RESULTS: Accuracies were in the range of -13.7 to 13.2% and intra-day and inter-day precisions in the range of 1.1 to 10.5%. The linearity within the calibration ranges expressed as coefficient of determination was higher than 0.995 for all compounds. Matrix effects and recovery efficiencies were within acceptable limits. The limits of quantitation varied from 0.02 to 10.7 µg/L. The stability of the drugs in serum at different conditions was tested. Diltiazem was not stable at 4-8 °C with up to 23.5 % loss after six days. Degradation of atenolol, irbesartan, bendroflumethiazide, hydrochlorothiazide and diltiazem was observed when stored at 30 °C. The suitability of the method was demonstrated in a routine TDM setting, analysing samples from 127 patients undergoing antihypertensive drug treatment.


Subject(s)
Antihypertensive Agents/blood , Drug Monitoring/methods , Tandem Mass Spectrometry/methods , Adrenergic alpha-Antagonists/blood , Adrenergic beta-Antagonists/blood , Angiotensin Receptor Antagonists/blood , Angiotensin-Converting Enzyme Inhibitors/blood , Calcium Channel Blockers/blood , Calibration , Chromatography, High Pressure Liquid/methods , Diuretics/blood , Humans , Limit of Detection , Metabolome/physiology , Reproducibility of Results , Serum
17.
Sci Total Environ ; 610-611: 555-562, 2018 Jan 01.
Article in English | MEDLINE | ID: mdl-28822339

ABSTRACT

Anthropogenic increase of nitrogen (N) deposition has threatened forest ecosystem health at both regional and global scales. In N-limited ecosystems, atmospheric N input is regarded as an important nutrient source for plant growth. However, it remains an open question on how elevated N deposition affects plant growth in N-rich forest ecosystems. To address this question, we used a simulated N deposition experiment in an N-rich mature tropical forest of southern China, with N addition levels as 0kgNha-1yr-1 (Control), 50kgNha-1yr-1 (Low-N), 100kgNha-1yr-1 (Middle-N) and 150kgNha-1yr-1 (High-N), respectively. We measured foliar nutrient element status (e.g., N, P, K, Ca and Mg), N metabolism and photosynthesis capacity of three dominant understory plant species (Cryptocarya concinna and Cryptocarya chinensis as medium-light species; and Randia canthioides as shade tolerant species) in this forest. Results showed that two years of N addition greatly increased foliar N content, but decreased the content of nutrient cations (e.g., K, Ca and Mg). Nitrogen addition also increased N accumulation as organic forms as soluble protein and/or free amino acid (FAA), but not as chlorophyll in all three species. We further found that the photosynthesis capacity (Pmax) of C. concinna and C. chinensis decreased significantly with elevated N addition, with no effects on R. canthioides. However, photosynthetic nitrogen use efficiency (PNUE) significantly declined with N addition for all three species, with significantly negative relationships between PNUE/Pmax and foliar N content. These findings suggest that excess N inputs can accelerate nutrient imbalance, and inhibit photosynthetic capacity of understory plant species, indicating continuous high N deposition can threat understory plant growth in N-rich tropical forests in the future. Meanwhile, PNUE can be used as a sensitive indicator to assess ecosystem N status under chronic N deposition.

18.
J Anal Toxicol ; 41(8): 708-709, 2017 Oct 01.
Article in English | MEDLINE | ID: mdl-28985336

ABSTRACT

Two young males were hospitalized with miosis and respiratory dysfunction after exposure to a white powder obtained from a foreign source by mail. A few days later, one of the males was found dead at his home. A serum sample from one of the hospitalized patients and a blood sample from the deceased contained ortho-fluorofentanyl in concentrations of 2.5 and 2.4 ng/mL, respectively. It was concluded that death was caused by ortho-fluorofentanyl.


Subject(s)
Analgesics, Opioid/blood , Drug Overdose/diagnosis , Fentanyl/blood , Adult , Drug Overdose/blood , Fatal Outcome , Fentanyl/analogs & derivatives , Hospitalization , Humans , Male , Miosis/diagnosis , Respiratory Insufficiency/diagnosis
20.
Gynecol Oncol ; 145(1): 148-153, 2017 04.
Article in English | MEDLINE | ID: mdl-28202195

ABSTRACT

OBJECTIVE: Evaluate long-term cisplatin-induced ototoxicity in women treated for malignant ovarian germ cell tumors (MOGCT). METHODS: Seventy-four women treated for MOGCT in Norway (1980-2009) were analyzed: 41 had received cisplatin-based chemotherapy (CBCT) ("Cases") and 33 had no CBCT ("Controls"). Median follow-up was 15years. Hearing was assessed by pure tone audiometry and by the SCIN questionnaire. Air conduction thresholds were reported as absolute hearing thresholds and age-adjusted thresholds. Absolute and age-adjusted hearing loss were defined as thresholds of >20dB at any frequency. Tinnitus was evaluated using the Tinnitus Handicap Inventory. Serum Platinum Concentration (SPC) was determined. RESULTS: Absolute hearing loss was identified in 21 Cases (51%) and 24 Controls (73%). After adjusting for age, only 9 Cases (22%) and 5 Controls (15%) remained. Age-adjusted hearing thresholds at 4, 6 and 8kHz were slightly but significantly higher in Cases compared to Controls. Subjective hearing loss was reported by 27% of Cases and 21% of Controls, who were significantly older. Elevated SPC values were detected up to 20years after CBCT, but SPC did not correlate significantly with age-adjusted hearing loss. The rate of tinnitus was similar in Cases and Controls. CONCLUSION: Long-term MOGCT survivors treated with CBCT have small but significant reductions in age-adjusted hearing thresholds at 4, 6 and 8kHz versus Controls. Approximately one in four women experienced subjective hearing loss. To avoid overestimation of clinically relevant cisplatin-induced ototoxicity, absolute hearing thresholds should be age-adjusted and compared to an age-matched control group.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/adverse effects , Cisplatin/adverse effects , Hearing Loss/chemically induced , Neoplasms, Germ Cell and Embryonal/drug therapy , Ovarian Neoplasms/drug therapy , Ovariectomy , Adolescent , Adult , Aged , Aged, 80 and over , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Audiometry, Pure-Tone , Bleomycin/administration & dosage , Case-Control Studies , Chemotherapy, Adjuvant , Child , Cisplatin/administration & dosage , Etoposide/administration & dosage , Female , Hearing Loss/blood , Humans , Longitudinal Studies , Middle Aged , Platinum/blood , Vinblastine/administration & dosage , Young Adult
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