Intravenous and sublingual buprenorphine in horses: pharmacokinetics and influence of sampling site

ObjectiveTo describe the pharmacokinetics and adverse effects of intravenous (IV) and sublingual (SL) buprenorphine in horses, and to determine the effect of sampling site on plasma concentrations after SL administration.Study designRandomized crossover experiment; prospective study.AnimalsEleven healthy adult horses between 6 and 20 years of age and weighing 487–592 kg.MethodsIn the first phase; buprenorphine was administered as a single IV or SL dose (0.006 mg kg^?1) and pharmacokinetic parameters were determined for each route of administration using a noncompartmental model. In the second phase; the jugular and lateral thoracic veins were catheterized for simultaneous venous blood sampling, following a dose of 0.006 mg kg^?1 SL buprenorphine. For both phases, plasma buprenorphine concentrations were measured using ultra-performance liquid chromatography with mass spectrometry. At each sampling period, horses were assessed for behavioral excitement and gastrointestinal motility.ResultsFollowing IV administration, buprenorphine mean ± SD half-life was 5.79 ± 1.09 hours. Systemic clearance (Cl) following IV administration was 6.13 ± 0.86 mL kg^?1 minute^?1 and volume of distribution at steady-state was 3.16 ± 0.65 L kg^?1. Following IV administration, horses showed signs of excitement. Gastrointestinal sounds were decreased following both routes of administration; however, none of the horses exhibited signs of colic. There was a significant discrepancy between plasma buprenorphine concentrations measured in the jugular vein versus the lateral thoracic vein following phase 2, thus pharmacokinetic parameters following SL buprenorphine are not reported.Conclusions and clinical relevanceBuprenorphine has a long plasma half-life and results in plasma concentrations that are consistent with analgesia in other species for up to 4 hours following IV administration of this dose in horses. While buprenorphine is absorbed into the circulation following SL administration, jugular venous sampling gave a false measurement of the quantity absorbed and should not be used to study the uptake from SL administration.     

Interpreting the spatio-temporal patterns of sea turtle strandings: Going with the flow

Knowledge of the spatial and temporal distribution of specific mortality sources is crucial for management of species that are vulnerable to human interactions. Beachcast carcasses represent an unknown fraction of at-sea mortalities. While a variety of physical (e.g., water temperature) and biological (e.g., decomposition) factors as well as the distribution of animals and their mortality sources likely affect the probability of carcass stranding, physical oceanography plays a major role in where and when carcasses strand. Here, we evaluate the influence of nearshore physical oceanographic and wind regimes on sea turtle strandings to decipher seasonal trends and make qualitative predictions about stranding patterns along oceanfront beaches. We use results from oceanic drift-bottle experiments to check our predictions and provide an upper limit on stranding proportions. We compare predicted current regimes from a 3D physical oceanographic model to spatial and temporal locations of both sea turtle carcass strandings and drift bottle landfalls. Drift bottle return rates suggest an upper limit for the proportion of sea turtle carcasses that strand (about 20%). In the South Atlantic Bight, seasonal development of along-shelf flow coincides with increased numbers of strandings of both turtles and drift bottles in late spring and early summer. The model also predicts net offshore flow of surface waters during winter - the season with the fewest relative strandings. The drift bottle data provide a reasonable upper bound on how likely carcasses are to reach land from points offshore and bound the general timeframe for stranding post-mortem (< two weeks). Our findings suggest that marine turtle strandings follow a seasonal regime predictable from physical oceanography and mimicked by drift bottle experiments. Managers can use these findings to reevaluate incidental strandings limits and fishery takes for both nearshore and offshore mortality sources.     

Smoke-derived taint in wine: the release of smoke-derived volatile phenols during fermentation of Merlot juice following grapevine exposure to smoke

The release of smoke-derived volatile phenols during the fermentation of Merlot grapes, following grapevine exposure to smoke, has been investigated. The concentrations of guaiacol, 4-methylguaiacol, 4-ethylguaiacol, 4-ethylphenol, and eugenol were determined by gas chromatography-mass spectrometry and found to increase throughout the winemaking process. Only trace levels (< or = 1 microg/L) of guaiacol and 4-methylguaiacol could be detected in free run juice derived from the fruit of smoked vines; the highest levels, 388 microg/L and 93 microg/L, respectively, were observed in the finished wine. Control wine (derived from fruit of unsmoked vines) contained 4 microg/L guaiacol, with the volatile phenols either not detected or detected at only trace levels (< or = 1 microg/L) throughout fermentation. The role of enzyme and acid catalyzed hydrolysis reactions in releasing smoke-derived volatile compounds was also investigated. The volatile phenols were released from smoked free run juice by strong acid hydrolysis (pH 1.0) and enzyme (beta-glucosidase) hydrolysis, but not mild acid hydrolysis (juice pH 3.2-3.7). Guaiacol was again the most abundant smoke-derived phenol, present at 431 microg/L and 325 microg/L in strong acid and enzyme hydrolysates, respectively. Only trace levels of each phenol could be detected in each control hydrolysate. This study demonstrates the potential for under-estimation of smoke taint in fruit and juice samples; the implications for the assessment of smoke taint and quantification of volatile phenols are discussed.     

Redwood/tanoak stand development and response to tanoak mortality caused by Phytophthora ramorum

Coast redwood (Sequoia sempervirens) and tanoak (Lithocarpus densiflorus) form mixed-evergreen forests along the northern California coast. In the mid-1990s, an introduced pathogen (Phytophthora ramorum) began causing extensive mortality of tanoak in these forests. This research reconstructed stand development patterns occurring in stands with and without the pathogen, measured stand responses to tanoak mortality, and developed projections of future stand development and structure in the presence of P. ramorum. Redwood forms an upper canopy layer while tanoak forms a multicohort lower canopy, resulting in distinct vertical stratification patterns. Individual redwood tree response patterns to tanoak mortality included crown expansion, increased basal sprouting, and increased basal area growth. Future stand structures will likely have greater proportions of redwood relative to tanoak.