Causes of death and pathogen prevalence in bottlenose dolphins Tursiops truncatus stranded in Alabama, USA, between 2015 and 2020, following the Deepwater Horizon oil spill.

Between 2010 and 2014, an unusual mortality event (UME) involving bottlenose dolphins Tursiops truncatus occurred in the northern Gulf of Mexico, associated with the Deepwater Horizon oil spill (DWHOS). Cause of death (COD) patterns in bottlenose dolphins since then have not been analyzed, and baseline prevalence data for Brucella ceti and cetacean morbillivirus, 2 pathogens previously reported in this region, are lacking. We analyzed records from bottlenose dolphins stranded in Alabama from 2015 to 2020 with necropsy and histological findings to determine COD (n = 108). This period included another UME in 2019 associated with prolonged freshwater exposure. A subset of individuals that stranded during this period were selected for molecular testing for Brucella spp. and Morbillivirus spp. Causes of death for all age classes were grouped into 6 categories, including (1) human interaction, (2) infectious disease, (3) noninfectious disease (prolonged freshwater exposure and degenerative), (4) trauma, (5) multifactorial, and (6) unknown. Two additional categories unique to perinates included fetal distress and in utero pneumonia. Human interaction was the most common primary COD (19.4%) followed closely by infectious disease (17.6%) and noninfectious disease (freshwater exposure; 13.9%). Brucella was detected in 18.4% of the 98 animals tested, but morbillivirus was not detected in any of the 66 animals tested. Brucella was detected in some moderately to severely decomposed carcasses, indicating that it may be beneficial to test a broad condition range of stranded animals. This study provides valuable information on COD in bottlenose dolphins in Alabama following the DWHOS and is the first to examine baseline prevalence of 2 common pathogens in stranded animals from this region.

Convergence of marine megafauna movement patterns in coastal and open oceans.

The extent of increasing anthropogenic impacts on large marine vertebrates partly depends on the animals' movement patterns. Effective conservation requires identification of the key drivers of movement including intrinsic properties and extrinsic constraints associated with the dynamic nature of the environments the animals inhabit. However, the relative importance of intrinsic versus extrinsic factors remains elusive. We analyze a global dataset of ∼2.8 million locations from >2,600 tracked individuals across 50 marine vertebrates evolutionarily separated by millions of years and using different locomotion modes (fly, swim, walk/paddle). Strikingly, movement patterns show a remarkable convergence, being strongly conserved across species and independent of body length and mass, despite these traits ranging over 10 orders of magnitude among the species studied. This represents a fundamental difference between marine and terrestrial vertebrates not previously identified, likely linked to the reduced costs of locomotion in water. Movement patterns were primarily explained by the interaction between species-specific traits and the habitat(s) they move through, resulting in complex movement patterns when moving close to coasts compared with more predictable patterns when moving in open oceans. This distinct difference may be associated with greater complexity within coastal microhabitats, highlighting a critical role of preferred habitat in shaping marine vertebrate global movements. Efforts to develop understanding of the characteristics of vertebrate movement should consider the habitat(s) through which they move to identify how movement patterns will alter with forecasted severe ocean changes, such as reduced Arctic sea ice cover, sea level rise, and declining oxygen content.

The importance of sample size in marine megafauna tagging studies.

Telemetry is a key, widely used tool to understand marine megafauna distribution, habitat use, behavior, and physiology; however, a critical question remains: "How many animals should be tracked to acquire meaningful data sets?" This question has wide-ranging implications including considerations of statistical power, animal ethics, logistics, and cost. While power analyses can inform sample sizes needed for statistical significance, they require some initial data inputs that are often unavailable. To inform the planning of telemetry and biologging studies of marine megafauna where few or no data are available or where resources are limited, we reviewed the types of information that have been obtained in previously published studies using different sample sizes. We considered sample sizes from one to >100 individuals and synthesized empirical findings, detailing the information that can be gathered with increasing sample sizes. We complement this review with simulations, using real data, to show the impact of sample size when trying to address various research questions in movement ecology of marine megafauna. We also highlight the value of collaborative, synthetic studies to enhance sample sizes and broaden the range, scale, and scope of questions that can be answered.

The effect of lipid extraction on carbon and nitrogen stable isotope ratios in oyster tissues: Implications for glycogen-rich species.

RATIONALE: Extraction of lipids from tissues prior to carbon stable isotope analysis (SIA) has become a common practice, despite a lack of species-specific data to indicate when lipid extraction is needed. Marine invertebrates, including bivalves, are known to store carbon as glycogen and less in the form of lipids than other species, potentially reducing the need for lipid extraction even when C:N values are above 3.5, a value that previous studies suggest indicates a need for lipid extraction of animal tissues. METHODS: We investigated the need for lipid extraction on individual tissues (adductor muscle, gut gland, gill) and whole tissue of a glycogen-storing species, the oyster Crassostrea virginica. Bulk and lipid-extracted samples were analyzed for their C and N stable isotope ratios by continuous flow isotope ratio mass spectrometry (IRMS). Samples were analyzed on a 20-20 isotope ratio mass spectrometer (PDZ Europa) after combustion in an elemental analyzer (PDZ Europa Automatic Analyzer-Gas Solid Liquid). RESULTS: Although the C:N values for most bulk (unextracted) tissue samples were greater than 3.5, the lipid-extracted δ13 C values did not differ from the bulk values. Lipid extraction, however, affected δ15 N values in all tissue types except adductor muscle, indicating that separate SIA may be required when tissues are lipid extracted. CONCLUSIONS: These data demonstrate that it is not necessary to lipid extract oyster tissues in all cases, and that C:N thresholds for lipid extraction in other species may not be reliable for organisms such as oysters that store glycogen. Our data indicate that minimizing unnecessary lipid extraction through preliminary testing will save researchers time and expense by avoiding superfluous sample handling, reducing concern over secondary effects on data quality, and reducing the costs of reagents and additional separate stable isotope analysis to ensure analytical accuracy. Copyright © 2016 John Wiley & Sons, Ltd.

GLC determination of aprindine in human plasma using a nitrogen--phosphorus flame-ionization detector.

A procedure for the determinations of aprindine in human plasma was developed. After the addition of N,N-diethyl-N'-(1,2,3,4-tetrahydro-2-naphthyl)-N'-phenyl-1,3-propanediamine as an internal standard, the plasma was buffered to pH 8.0, and the drug and the internal standard were extracted into ethyl acetate-hexane (9:1 v/v). The compounds then were extracted from the organic phase into 0.02 N HCl. The acidic solution was made basic with 0.2 M tribasic sodium phosphate, and aprindine and the internal standard were extracted into a small volume of hexane. The compounds were analyzed by GLC using a nitrogen--phosphorus flame-ionization detector. The drug concentration and instrument response were linear for 0.10--1.00 microgram of aprindine/ml, the slope was 1.1416 (0.0141), the y intercept was 0.0096 +/- 0.0082, and the correlation coefficient was 0.99960 +/- 0.00002. The sensitivity of the method was 0.02 microgram of aprindine/ml. The within-day coefficient of variation was 9.50, 3.14, and 2.21% for 0.05, 0.20, 0.40, and 0.80 microgram of aprindine/ml, respectively. The between-day coefficient of variation was 17.4, 3.40, 2.07, and 1.54% at the same concentrations. Total precision values of 19.9, 4.60, 4.26, and 2.69% were obtained. The overall relative error of the method +1.33, +2.00, -0.07, and +0.25% at these concentrations.

Benoxaprofen, a new anti-inflammatory agent: particle-size effect on dissolution rate and oral absorption in humans.

The particle-size effect of benoxaprofen, a new nonsteroidal anti-inflammatory agent, on the in vitro dissolution rate and oral absorption in humans was evaluated. Ten normal subjects participated in a randomized crossover-designed absorption study with two sieved particle-size formulations: one with crystals larger than 60 mesh (mean equivalent spherical diameter = 640 micron) and the other with crystals smaller than 100 mesh (mean equivalent spherical diameter = 67 micron). Plasma drug concentrations and urinary drug excretion were used to determine the relative absorption of the two formulations. The standard USP procedure was used for the dissolution study. Particle size had a dramatic effect on both the in vitro drug dissolution and its oral absorption in humans. In vitro, the smaller crystals dissolved more rapidly and more efficiently than the larger crystals. In vivo, the smaller crystals produced higher plasma concentrations, more rapid peak concentration attainment, and more drug excreted in the urine.

Pharmacokinetic studies of benoxaprofen after therapeutic doses with a review of related pharmacokinetic and metabolic studies.

The pharmacokinetics of benoxaprofen in therapeutic doses of 400 or 600 mg as a solution, capsule or tablet were determined in 44 men after single or multiple doses. The plasma levels of the drug after oral administration of a solution best fitted a 2-compartment open pharmacokinetic model, whereas the levels after the solid dosage forms more appropriately fitted the simple 1-compartment open model. The plasma elimination half-life of the drug, when in solid dosage form, was found to be in the range of 19-26 h, justifying once-a-day dosage. Steady state levels of benoxaprofen were obtained after the 5th dose of a 400 mg capsule every 24 h.

Tracer microspheres as compliance markers in clinical research.

Tracer microspheres are small, ceramic-like particles (50 micron) containing one of several radionuclide markers. We have utilized them over a period of 9 years as quantitative fecal markers for recovery measurements in metabolic studies. The markers have been administered daily for up to 2 weeks, during which time the marker concentration per unit dry weight of feces remains fairly constant. Data on the markers and our experience with them are presented along with the concerns that must be addressed in considering them as compliance markers.

The effect of crystal size on the bioavailability of benoxaprofen: studies utilizing deuterium labeled drug.

A study of the effect of crystal size on the bioavailability of benoxaprofen, 2-[4-chlorophenyl]-alpha-methyl-5-benzoxazoleacetic acid, in man is reported. The technique utilized comparison of either the plasma concentrations or urine levels, resulting from administration of deuterium labeled (2H7) drug in solution coadministered with a test capsule formulation. Drug concentrations were determined by gas chromatography, and the ratio of labeled to unlabeled drug was obtained by gas chromatography mass spectrometry. Measurements following coadministration of labeled and unlabeled drug in solution established the absence of an isotope effect due to the presence of deuterium. The dry formulations consisted of either a 3.17--100 micron fraction (mean = 18.5 microns) or a 32--1000 micron fraction (mean = 610 microns) formulated with starch powder. The results in three subjects indicate an almost complete availability (0.95--0.98) of the small crystals as measured by comparison of either area under the plasma level curves or urine excretion (0.94--0.97) of labeled versus unlabeled drug measured to 168 hours. The larger crystals exhibited a lower availability as shown by plasma levels (0.41--0.46) or urine recovery (0.39--0.43). A higher dose of the large crystal formulation resulted in decreased relative availability with a fourfold dose dropping availability to 0.22 in a single subject.

Determination of fluoxetine and norfluoxetine in plasma by gas chromatography with electron-capture detection.

This gas-chromatographic method for assay of fluoxetine and norfluoxetine in human plasma involves extraction of the drugs and use of a 63Ni electron-capture detector. The linear range of detection is 25 to 800 micrograms/L for each drug. Overall precision (CV) in the concentration range of 10 to 100 micrograms/L for both drugs was approximately 10%. Accuracy (relative error) in the same concentration range was approximately +10%. None of the commonly prescribed antidepressants or tranquilizers that we tested interfere with the assay.

Clinical pharmacology of benoxaprofen.

Eating does not modify benoxaprofen blood concentrations. Combining benoxaprofen with tolbutamide does not significantly change plasma glucose, insulin, or tolbutamide concentrations. Probenecid, by blocking renal tubular secretion of benoxaprofen, increases the benoxaprofen half-life and decreases its renal clearance and urinary excretion. Excretion rate is halved in patients with severe renal impairment. Hemodialysis inefficiently lowers benoxaprofen plasma concentrations. Neither glomerular nor renal tubular function is affected by benoxaprofen, even after five years of therapy. The incidence in urine of microscopic spheroids (benoxaprofen glucuronide complexes) is related to urinary drug concentration and osmolality; increasing the fluid intake decreases incidence.