Salidroside directly activates HSC70, revealing a new role for HSC70 in BDNF signalling and neurogenesis after cerebral ischemia.

Salidroside, a principal bioactive component of Rhodiola crenulata, is neuroprotective across a wide time window in stroke models. We investigated whether salidroside induced neurogenesis after cerebral ischemia and aimed to identify its primary molecular targets. Rats, subjected to transient 2 h of middle cerebral artery occlusion (MCAO), received intraperitoneal vehicle or salidroside ± intracerebroventricular HSC70 inhibitor VER155008 or TrkB inhibitor ANA-12 for up to 7 days. MRI, behavioural tests, immunofluorescent staining and western blotting measured effects of salidroside. Reverse virtual docking and enzymatic assays assessed interaction of salidroside with purified recombinant HSC70. Salidroside dose-dependently decreased cerebral infarct volumes and neurological deficits, with maximal effects by 50 mg/kg/day. This dose also improved performance in beam balance and Morris water maze tests. Salidroside significantly increased BrdU+/nestin+, BrdU+/DCX+, BrdU+/NeuN+, BrdU-/NeuN+ and BDNF+ cells in the peri-infarct cortex, with less effect in striatum and no significant effect in the subventricular zone. Salidroside was predicted to bind with HSC70. Salidroside dose-dependently increased HSC70 ATPase and HSC70-dependent luciferase activities, but it did not activate HSP70. HSC70 immunoreactivity concentrated in the peri-infarct cortex and was unchanged by salidroside. However, VER155008 prevented salidroside-dependent increases of neurogenesis, BrdU-/NeuN+ cells and BDNF+ cells in peri-infarct cortex. Salidroside also increased BDNF protein and p-TrkB/TrkB ratio in ischemic brain, changes prevented by VER155008 and ANA-12, respectively. Additionally, ANA-12 blocked salidroside-dependent neurogenesis and increased BrdU-/NeuN+ cells in the peri-infarct cortex. Salidroside directly activates HSC70, thereby stimulating neurogenesis and neuroprotection via BDNF/TrkB signalling after MCAO. Salidroside and similar activators of HSC70 might provide clinical therapies for ischemic stroke.

Emodepside targets SLO-1 channels of Onchocerca ochengi and induces broad anthelmintic effects in a bovine model of onchocerciasis.

Onchocerciasis (river blindness), caused by the filarial worm Onchocerca volvulus, is a neglected tropical disease mostly affecting sub-Saharan Africa and is responsible for >1.3 million years lived with disability. Current control relies almost entirely on ivermectin, which suppresses symptoms caused by the first-stage larvae (microfilariae) but does not kill the long-lived adults. Here, we evaluated emodepside, a semi-synthetic cyclooctadepsipeptide registered for deworming applications in companion animals, for activity against adult filariae (i.e., as a macrofilaricide). We demonstrate the equivalence of emodepside activity on SLO-1 potassium channels in Onchocerca volvulus and Onchocerca ochengi, its sister species from cattle. Evaluation of emodepside in cattle as single or 7-day treatments at two doses (0.15 and 0.75 mg/kg) revealed rapid activity against microfilariae, prolonged suppression of female worm fecundity, and macrofilaricidal effects by 18 months post treatment. The drug was well tolerated, causing only transiently increased blood glucose. Female adult worms were mostly paralyzed; however, some retained metabolic activity even in the multiple high-dose group. These data support ongoing clinical development of emodepside to treat river blindness.

Synthesis and identification of a novel derivative of salidroside as a selective, competitive inhibitor of monoamine oxidase B with enhanced neuroprotective properties.

Salidroside [(2R,3S,4S,5R,6R)-2-(hydroxymethyl)-6-(4-hydroxyphenethoxy)tetrahy-dro-2H-pyran-3,4,5-triol] is an antioxidant, anti-inflammatory and neuroprotective agent, but its drug-like properties are unoptimized and its mechanism of actions is uncertain. We synthesized twenty-six novel derivatives of salidroside and examined them in CoCl2-treated PC12 cells using MTT assay. pOBz, synthesized by esterifying the phenolic hydroxyl group of salidroside with benzoyl chloride, was one of five derivatives that were more cytoprotective than salidroside, with an EC50 of 0.038 µM versus 0.30 µM for salidroside. pOBz was also more lipophilic, with log P of 1.44 versus -0.89 for salidroside. Reverse virtual docking predicted that pOBz would bind strongly with monoamine oxidase (MAO) B by occupying its entrance and substrate cavities, and by interacting with the inter-cavity gating residue Ile199 and Tyr435 of the substrate cavity. Enzymatic studies confirmed that pOBz competitively inhibited the activity of purified human MAO-B (Ki = 0.041 µM versus Ki = 0.92 µM for salidroside), and pOBz was highly selective for MAO-B over MAO-A. In vivo, pOBz inhibited cerebral MAO activity after middle cerebral artery occlusion with reperfusion in rats, and it reduced cerebral infarct volume, improved neurological function and NeuN expression, and inhibited complement C3 expression and apoptosis. Our results suggest that pOBz is a structurally novel type of competitive and selective MAO-B inhibitor, with potent neuroprotective properties after cerebral ischemia-reperfusion injury in rats.

3D RNA-seq: a powerful and flexible tool for rapid and accurate differential expression and alternative splicing analysis of RNA-seq data for biologists.

RNA-sequencing (RNA-seq) analysis of gene expression and alternative splicing should be routine and robust but is often a bottleneck for biologists because of different and complex analysis programs and reliance on specialized bioinformatics skills. We have developed the '3D RNA-seq' App, an R shiny App and web-based pipeline for the comprehensive analysis of RNA-seq data from any organism. It represents an easy-to-use, flexible and powerful tool for analysis of both gene and transcript-level gene expression to identify differential gene/transcript expression, differential alternative splicing and differential transcript usage (3D) as well as isoform switching from RNA-seq data. 3D RNA-seq integrates state-of-the-art differential expression analysis tools and adopts best practice for RNA-seq analysis. The program is designed to be run by biologists with minimal bioinformatics experience (or by bioinformaticians) allowing lab scientists to analyse their RNA-seq data. It achieves this by operating through a user-friendly graphical interface which automates the data flow through the programs in the pipeline. The comprehensive analysis performed by 3D RNA-seq is extremely rapid and accurate, can handle complex experimental designs, allows user setting of statistical parameters, visualizes the results through graphics and tables, and generates publication quality figures such as heat-maps, expression profiles and GO enrichment plots. The utility of 3D RNA-seq is illustrated by analysis of data from a time-series of cold-treated Arabidopsis plants and from dexamethasone-treated male and female mouse cortex and hypothalamus data identifying dexamethasone-induced sex- and brain region-specific differential gene expression and alternative splicing.

Investigating the potential of novel non-woven fabrics for efficient pollination control in plant breeding.

Plant breeding is achieved through the controlled self- or cross-pollination of individuals and typically involves isolation of floral parts from selected parental plants. Paper, cellulose or synthetic materials are used to avoid self pollination or cross contamination. Low seed set limits the rate of breeding progress and increases costs. We hypothesized that a novel 'non-woven' fabric optimal for both pollination and seed set in multiple plant species could be developed. After determining the baseline pollen characteristics and usage requirements we established iterative three phase development and biological testing. This determined (1) that white fabric gave superior seed return and informed the (2) development of three non-woven materials using different fibre and layering techniques. We tested their performance in selfing and hybridisation experiments recording differences in performance by material type within species. Finally we (3) developed further advanced fabrics with increased air permeability and tested biological performance. An interaction between material type and species was observed and environmental decoupling investigated, showing that the non-woven fabrics had superior water vapour transmission and temperature regulation compared to controls. Overall, non-woven fabrics outperformed existing materials for both pollination and seed set and we found that different materials can optimize species-specific, rather than species-generic performance.

The CBP® mirror image® approach to reducing thoracic hyperkyphosis: a retrospective case series of 10 patients.

[Purpose] To present a case series demonstrating the reduction of thoracic hyperkyphosis by the Chiropractic BioPhysics® multimodal rehabilitation program. [Participants and Methods] Ten randomly selected files and corresponding radiographs were chosen from recent clinic archives of patients who were treated for thoracic hyperkyphosis. All patients were treated by CBP mirror image® thoracic extension traction and exercises, as well as spinal manipulative therapy. [Results] Results demonstrated an average reduction in hyperkyphosis of 11.3° over an average of 25 treatments, over an average of 9 weeks. Patients also experienced a reduction in pain levels and disability ratings. [Conclusion] Postural hyperkyphosis is a serious progressive deformity that is related to a plethora of symptoms, syndromes, and early death. Thoracic hyperkyphosis may be reduced/corrected by posture-specific, thoracic extension protocols including mirror image extension traction and exercises, as well as spinal manipulation as part of the CBP multi-modal rehabilitation program.

Consolidation hyperthermic intraperitoneal chemotherapy for the treatment of advanced stage ovarian carcinoma: a 3 year experience.

PURPOSE: Hyperthermic intraperitoneal chemotherapy (HIPEC) potentially confers significant survival benefits in the management of ovarian cancer although the long-term data remain scant. We sought to compare the survival rates of advanced stage ovarian cancer patients who were treated with primary induction therapy alone or in conjunction with consolidation HIPEC. METHODS: 69 ovarian cancer patients who underwent surgery and completed their primary induction chemotherapy were treated with consolidation carboplatin (AUC 10) based HIPEC and compared to a historical cohort that received surgery and primary chemotherapy alone (n = 69). The demographic and clinical characteristics on which we were primarily focused, included patient age, body mass index, surgery and pathology data, chemotherapy regimen, toxicity, and progression free/overall survival. RESULTS: The two patient groups' demographic and clinical characteristics were similar (P > 0.05). Progression-free survival was significantly more pronounced in the HIPEC (25.1 months) patients compared to the control group (20 months) (P = 0.024) and there was a decreased risk of disease progression accorded to the patients treated with HIPEC (HR 2.1028; 95% CI 1.2941-3.4167; P = 0.0027). However, we did not discern any HIPEC related overall survival advantages (P = 0.29). CONCLUSIONS: The results from our ovarian cancer study suggest that adjunctive HIPEC proffers a significant progression-free survival advantage and a decreased risk for disease progression. There was, however, no overall survival advantage discerned by the HIPEC group. We also recognize that HIPEC remains controversial, and thus randomized studies evaluating HIPEC compared to standard chemotherapy in the management of ovarian cancer are warranted.

A BMI >35 does not protect patients undergoing cardiac bypass surgery from red blood cell transfusion.

The effect of obesity on allogeneic intraoperative blood product transfusion in patients undergoing coronary artery bypass graft surgery (CABG) is poorly understood. We analyzed the influence of obesity on the risk of intraoperative red blood cell (RBC) transfusion among 45,200 consecutive non-reoperative CABG procedures from a multi-institutional perfusion database. A body mass index (BMI) in obese I category was associated with a 9.9% decrease in transfusion risk (p<0.05). Compared to patients with a normal BMI, obese I and obese III patients do not have any change in the relative risk of RBC transfusion. Overweight and mild obesity have a protective role in reducing intraoperative blood transfusion during cardiopulmonary bypass (CPB) surgery. However, logistic regression analysis showed that much of the observed reduction in transfusion rates for obese patients can be accounted for by other known confounds. The lack of a linear effect of increasing BMI on blood transfusion risk is a novel finding and warrants further investigation.

Measurement of Uranium Isotope Ratios in Keratinous Materials: A Noninvasive Bioassay for Special Nuclear Material.

Hair, toenail, and fingernail are noninvasive, integrative biological monitors routinely used to assess mineral intake.1-4 In this study, we demonstrate the feasibility of distinguishing between exposure to natural, depleted, and enriched U by measuring the (235)U/(238)U, (234)U/(238)U, and (236)U/(238)U ratios in the hair, fingernails, and toenails of occupationally exposed workers and control volunteers. The exposure history of cases and controls to non-natural U was assessed through voluntary self-reporting using a simple questionnaire. The measured U isotope ratios and U concentration in the hair, toenail, and fingernail of cases were compared to a nonexposed control group. No difference was observed in the uranium concentration between the two groups. Significant differences between the cases and the control group were observed in the (235)U/(238)U and (236)U/(238)U isotope ratios but not the (234)U/(238)U. This is the first time that hair, fingernail, and toenail have been demonstrated to be sensitive to occupational exposure to enriched and depleted U, a result with significant implications for proliferation compliance monitoring.

Evolutionary relationships among barley and Arabidopsis core circadian clock and clock-associated genes.

The circadian clock regulates a multitude of plant developmental and metabolic processes. In crop species, it contributes significantly to plant performance and productivity and to the adaptation and geographical range over which crops can be grown. To understand the clock in barley and how it relates to the components in the Arabidopsis thaliana clock, we have performed a systematic analysis of core circadian clock and clock-associated genes in barley, Arabidopsis and another eight species including tomato, potato, a range of monocotyledonous species and the moss, Physcomitrella patens. We have identified orthologues and paralogues of Arabidopsis genes which are conserved in all species, monocot/dicot differences, species-specific differences and variation in gene copy number (e.g. gene duplications among the various species). We propose that the common ancestor of barley and Arabidopsis had two-thirds of the key clock components identified in Arabidopsis prior to the separation of the monocot/dicot groups. After this separation, multiple independent gene duplication events took place in both monocot and dicot ancestors.

Enhancement of insecticides against codling moth (Lepidoptera: Tortricidae) with L-aspartate in laboratory and field experiments.

The idea of enhancing insecticide efficacy against phytophagous insects with feeding stimulators was proposed as early as the 1960s, and a number of insect feeding stimulators based on sugars, molasses, and cottonseed extracts, biologically active at relatively high (5% and higher) concentrations, have been advocated. Here, we show that an acidic amino acid, L-aspartate, stimulates feeding in codling moth neonates at much lower concentrations and acts as an effective tank-mixed additive for increasing efficacy of insecticides, reducing fruit damage, and increasing yield of the fruit. In laboratory experiments, 1 mg/ml L-aspartate increased foliage consumption by 40-60% and, when added to Assail 30 SG, Baythroid XL, Delegate WG, or Carbaryl 80S, maintained its feeding stimulatory properties and reduced LD50(s) by approximately 10 times. In a 3-yr field trial, addition of L-aspartate to the aforementioned insecticides at 395 g/ha reduced fruit damage from approximately 6%, on average to < 1% for first-generation codling moth, and from approximately 20 to approximately 5% for the second generation. Interestingly, addition of L-aspartate also increased the average weight of apples by 11-27%, as measured at the time of harvest.

Effects of α-lipoic acid on mtDNA damage after isolated muscle contractions.

INTRODUCTION: Although pharmacological antioxidants have previously been investigated for a prophylactic effect against exercise oxidative stress, it is not known if α-lipoic acid supplementation can protect against DNA damage after high-intensity isolated quadriceps exercise. This randomized controlled investigation was designed to test the hypothesis that 14 d of α-lipoic acid supplementation can attenuate exercise-induced oxidative stress. METHODS: Twelve (n = 12) apparently healthy male participants (age = 28 ± 10 yr, stature = 177 ± 12 cm and body mass = 81 ± 15 kg) were randomly assigned to receive either a daily supplement of 1000 mg of α-lipoic acid (2 × 500-mg tablets) for 14 d (n = 6) or receive no supplement (n = 6) in a double-blinded experimental approach. Blood and muscle biopsy tissue samples were taken at rest and after the completion of 100 isolated and continuous maximal knee extension (minimum force = 200 N, speed of contraction = 60° · s(-1)). RESULTS: Exercise increased mitochondrial 8-hydroxy-2-deoxyguanosine (8-OHdG) concentration in both groups (P < 0.05 vs rest) with a concomitant decrease in total antioxidant capacity (P < 0.05 vs rest). There was a marked increase in blood total antioxidant capacity after oral α-lipoic acid supplementation (P < 0.05 vs nonsupplemented), whereas DNA damage (Comet assay and 8-OHdG), lipid peroxidation, and hydrogen peroxide increased after exercise in the nonsupplemented group only (P < 0.05 vs supplemented). Exercise increased protein oxidation in both groups (P < 0.05 vs rest). CONCLUSIONS: These findings suggest that short-term α-lipoic acid supplementation can selectively protect DNA (but not in muscle mitochondria) and lipids against exercise-induced oxidative stress.

Acute and chronic watercress supplementation attenuates exercise-induced peripheral mononuclear cell DNA damage and lipid peroxidation.

Pharmacological antioxidant vitamins have previously been investigated for a prophylactic effect against exercise-induced oxidative stress. However, large doses are often required and may lead to a state of pro-oxidation and oxidative damage. Watercress contains an array of nutritional compounds such as ß-carotene and α-tocopherol which may increase protection against exercise-induced oxidative stress. The present randomised controlled investigation was designed to test the hypothesis that acute (consumption 2 h before exercise) and chronic (8 weeks consumption) watercress supplementation can attenuate exercise-induced oxidative stress. A total of ten apparently healthy male subjects (age 23 (SD 4) years, stature 179 (SD 10) cm and body mass 74 (SD 15) kg) were recruited to complete the 8-week chronic watercress intervention period (and then 8 weeks of control, with no ingestion) of the experiment before crossing over in order to compete the single-dose acute phase (with control, no ingestion). Blood samples were taken at baseline (pre-supplementation), at rest (pre-exercise) and following exercise. Each subject completed an incremental exercise test to volitional exhaustion following chronic and acute watercress supplementation or control. The main findings show an exercise-induced increase in DNA damage and lipid peroxidation over both acute and chronic control supplementation phases (P< 0.05 v. supplementation), while acute and chronic watercress attenuated DNA damage and lipid peroxidation and decreased H2O2 accumulation following exhaustive exercise (P< 0.05 v. control). A marked increase in the main lipid-soluble antioxidants (α-tocopherol, γ-tocopherol and xanthophyll) was observed following watercress supplementation (P< 0.05 v. control) in both experimental phases. These findings suggest that short- and long-term watercress ingestion has potential antioxidant effects against exercise-induced DNA damage and lipid peroxidation.

An hnRNP-like RNA-binding protein affects alternative splicing by in vivo interaction with transcripts in Arabidopsis thaliana.

Alternative splicing (AS) of pre-mRNAs is an important regulatory mechanism shaping the transcriptome. In plants, only few RNA-binding proteins are known to affect AS. Here, we show that the glycine-rich RNA-binding protein AtGRP7 influences AS in Arabidopsis thaliana. Using a high-resolution RT-PCR-based AS panel, we found significant changes in the ratios of AS isoforms for 59 of 288 analyzed AS events upon ectopic AtGRP7 expression. In particular, AtGRP7 affected the choice of alternative 5' splice sites preferentially. About half of the events are also influenced by the paralog AtGRP8, indicating that AtGRP7 and AtGRP8 share a network of downstream targets. For 10 events, the AS patterns were altered in opposite directions in plants with elevated AtGRP7 level or lacking AtGRP7. Importantly, RNA immunoprecipitation from plant extracts showed that several transcripts are bound by AtGRP7 in vivo and indeed represent direct targets. Furthermore, the effect of AtGRP7 on these AS events was abrogated by mutation of a single arginine that is required for its RNA-binding activity. This indicates that AtGRP7 impacts AS of these transcripts via direct interaction. As several of the AS events are also controlled by other splicing regulators, our data begin to provide insights into an AS network in Arabidopsis.

Implementation of a comprehensive blood conservation program can reduce blood use in a community cardiac surgery program.

OBJECTIVE: The study objective was to determine the effects of implementing a blood conservation algorithm on blood product use and outcomes in a community cardiac surgery program. METHODS: A blood management strategy including lower hemoglobin transfusion threshold and algorithm-driven decisions was adopted. Intraoperatively, point-of-care testing was used to avoid inappropriate component transfusion. A low prime perfusion circuit was adopted. Blood was withdrawn from patients before initiating bypass when possible. Patients undergoing coronary and valve procedures were included. Outlier patients receiving more than 10 units packed red blood cells were excluded. Data were collected for 6 months as a baseline group (group I). A 3-month period of program implementation was allotted. Data were subsequently collected for 6 months and comprised the study patients (group II). Prospective data were collected on demographics, blood use, and outcomes. RESULTS: Group I comprised 481 patients, and group II comprised 551 patients. Group II received fewer units of packed red blood cells, fresh-frozen plasma, and cryoprecipitate than group I. There was no difference in platelets transfused. Total blood product use was reduced by 40% in group II (P < .001). The overall 30-day mortality was 1.3%. There were no differences in mortality, reoperation for bleeding, or other postoperative outcomes between the groups. CONCLUSIONS: Implementation of a comprehensive blood conservation algorithm can be rapidly introduced, leading to reductions in blood and component use with no detrimental effect on early outcomes. Point-of-care testing can direct component transfusion in coagulopathic cases, with most coagulopathic patients requiring platelets. Further research will determine the effects of reduced transfusions on long-term outcomes.

Effects of Ginkgo biloba constituents on fruit-infesting behavior of codling moth (Cydia pomonella) in apples.

Codling moth, Cydia pomonella (L.), is a cosmopolitan pest of apple, potentially causing severe damage to the fruit. Currently used methods of combating this insect do not warrant full success or are harmful to the environment. The use of plant-derived semiochemicals for manipulation with fruit-infesting behavior is one of the new avenues for controlling this pest. Here, we explore the potential of Ginkgo biloba and its synthetic metabolites for preventing apple feeding and infestation by neonate larvae of C. pomonella. Experiments with crude extracts indicated that deterrent constituents of ginkgo are present among alkylphenols, terpene trilactones, and flavonol glycosides. Further experiments with ginkgo synthetic metabolites of medical importance, ginkgolic acids, kaempferol, quercetin, isorhamnetin, ginkgolides, and bilobalide, indicated that three out of these chemicals have feeding deterrent properties. Ginkgolic acid 15:0 prevented fruit infestation at concentrations as low as 1 mg/mL, bilobalide had deterrent effects at 0.1 mg/mL and higher concentrations, and ginkgolide B at 10 mg/mL. On the other hand, kaempferol and quercetin promoted fruit infestation by codling moth neonates. Ginkgolic acids 13:0, 15:1, and 17:1, isorhamnetin, and ginkgolides A and C had no effects on fruit infestation-related behavior. Our research is the first report showing that ginkgo constituents influence fruit infestation behavior and have potential applications in fruit protection.

Distribution and weathering of crude oil residues on shorelines 18 years after the Exxon Valdez spill.

In 2007, a systematic study was conducted to evaluate the form and location of residues of oil buried on Prince William Sound (PWS) shorelines, 18 years after the 1989 Exxon Valdez Oil Spill (EVOS). We took 678 sediment samples from 22 sites that were most heavily oiled in 1989 and known to contain the heaviest subsurface oil (SSO) deposits based on multiple studies conducted since 2001. An additional 66 samples were taken from two sites, both heavily oiled in 1989 and known to be active otter foraging sites. All samples were analyzed for total extractable hydrocarbons (TEH), and 25% were also analyzed for saturated and aromatic hydrocarbon weathering parameters. Over 90% of the samples from all sites contained light or no SSO at all. Of samples containing SSO, 81% showed total polycyclic aromatic hydrocarbon (TPAH) losses greater than 70%, relative to cargo oil, with most having >80% loss. Samples with SSO were observed in isolated patches sequestered by surface boulder and cobble armoring. Samples showing lowest TPAH loss correlated strongly with higher elevations in the intertidal zones. Of the 17 atypical, less-weathered samples having less than 70% loss of TPAH (>30% remaining), only two were found sequestered in the lower intertidal zone, both at a single site. Most of the EVOS oil in PWS has been eliminated due to natural weathering. Some isolated SSO residues remain because they are sequestered and only slowly affected by natural weathering processes that normally would bring about their rapid removal. Even where SSO patches remain, most are highly weathered, sporadically distributed at a small number of sites, and widely separated from biologically productive lower intertidal zones where most foraging by wildlife occurs.

Biomarkers of PAH exposure in an intertidal fish species from Prince William Sound, Alaska: 2004-2005.

Polycyclic aromatic hydrocarbon (PAH) exposure biomarkers were measured in high cockscomb prickleback (Anoplarchus purpurescens) fish collected from both previously oiled and unoiled shore in Prince William Sound (PWS), Alaska, to test the hypothesis that fish living in the nearshore environment of the sound were no longer being exposed to PAH from the Exxon Valdez oil spill. Pricklebacks spend their entire lives in the intertidal zone of rocky shores with short-term movements during feeding and breeding restricted to an area of about 15 meters in diameter. Fish were assayed for the PAH exposure biomarkers, bile fluorescent aromatic compounds (FAC), and liver ethoxyresorufin O-deethylase (EROD) activity (a measure of cytochrome P450 1A (CYP1A) monooxygenase activity). Bile FAC concentrations and EROD activities were low and not significantly different in fish from previously oiled and unoiled sites. The similar low EROD activity and bile FAC concentrations in fish from oiled and unoiled shores, supports the hypothesis that these low-level biomarker responses were not caused by exposure of the fish to residues of the spilled oil.

Toxicity of weathered Exxon Valdez crude oil to pink salmon embryos.

Research was conducted at the University of Idaho (Moscow, ID, USA) on the toxicity of weathered Exxon Valdez crude oil to embryos of pink salmon from 2001 to 2003 for the purpose of comparing these data with those from the National Oceanic and Atmospheric Administration Fisheries Laboratory at Auke Bay (AK, USA). Mortality reported at Auke Bay for embryos chronically exposed to very low concentrations of aqueous solutions of weathered oil, measured as dissolved polycyclic aromatic hydrocarbons (PAHs), was inconsistent with that in other published research. Using the Auke Bay experimental design, we found that toxicity is not evident in pink salmon embryos until chronic exposure to laboratory weathered and naturally weathered oil concentrations exceeding 1,500 and 2,250 ppm, respectively, representing a total PAH tissue burden in excess of 7,100 ppb. Effluent hydrocarbons also drop well below concentrations sufficient to cause harm over the time frame of a few weeks, regardless of oiling level. Resolution of differences with Auke Bay involved the source of contributing hydrocarbons. The experimental design did not exclude dispersed oil droplets from the aqueous solution; thus, toxicity was not limited to the dissolved hydrocarbon fraction. The implications of the present results are discussed regarding the toxic risk of weathered oil to pink salmon embryos in streams of Prince William Sound (AK, USA).

Differential effects of phosphodiesterase-5 inhibitors on hypoxic pulmonary vasoconstriction and pulmonary artery cytokine expression.

BACKGROUND: Perioperative pulmonary hypertension is a challenging clinical problem with numerous etiologies including hypoxia, adrenergic stimulation, and local inflammation. New oral phosphodiesterase-5 (PDE-5) inhibitors used for the treatment of erectile dysfunction may have beneficial effects on the pulmonary vasculature owing to the abundance of PDE-5 receptors in the lung. The purpose of this study was to compare the efficacy of sildenafil, vardenafil, and tadalafil in preventing acute hypoxic pulmonary vasoconstriction and hypoxia-induced pulmonary artery tumor necrosis factor-alpha (TNF-alpha) and interleukin-1-beta (IL-1beta) expression. METHODS: Isolated rat pulmonary arteries suspended in physiologic organ baths for measurement of isometric force transduction were treated with vehicle (dimethyl sulfoxide), sildenafil, vardenafil, or tadalafil to assess (1) pulmonary artery relaxation; (2) inhibition of phenylephrine-induced pulmonary artery contraction; (3) inhibition of hypoxic pulmonary vasoconstriction (pO2 = 30-35 mm Hg); and (4) hypoxia-induced pulmonary artery TNF-alpha and IL-1beta expression (reverse transcriptase-polymerase chain reaction). RESULTS: Sildenafil, vardenafil, and tadalafil resulted in dose-dependent pulmonary artery relaxation and inhibited phenylephrine-induced pulmonary artery contraction, but only tadalafil significantly inhibited hypoxic pulmonary vasoconstriction (52.08% +/- 7.65% tadalafil versus 88.63% +/- 8.96% vehicle; 98.61% +/- 10.04% sildenafil; 68.46% +/- 15.84% vardenafil). Hypoxia-induced upregulation of TNF-alpha and IL-1beta mRNA in pulmonary artery was significantly decreased by tadalafil, but not sildenafil or vardenafil pretreatment. CONCLUSIONS: We conclude that sildenafil, vardenafil, and tadalafil were equally efficacious in causing pulmonary artery relaxation, but only tadalafil inhibited hypoxic pulmonary vasoconstriction and attenuated hypoxia-induced pulmonary artery TNF-alpha and IL-1beta expression.