An Investigation Into the Effects of In Vitro Dilution With Different Colloid Resuscitation Fluids on Clot Microstructure Formation.

BACKGROUND: Balancing the beneficial effects of resuscitation fluids against their detrimental effect on hemostasis is an important clinical issue. We aim to compare the in vitro effects of 3 different colloid resuscitation fluids (4.5% albumin, hydroxyethyl starch [Voluven 6%], and gelatin [Geloplasma]) on clot microstructure formation using a novel viscoelastic technique, the gel point. This novel hemorheologic technique measures the biophysical properties of the clot and provides an assessment of clot microstructure from its viscoelastic properties. Importantly, in contrast to many assays in routine clinical use, the measurement is performed using unadulterated whole blood in a near-patient setting and provides rapid assessment of coagulation. We hypothesized that different colloids will have a lesser or greater detrimental effect on clot microstructure formation when compared against each other. METHODS: Healthy volunteers were recruited into the study (n = 104), and a 20-mL sample of whole blood was obtained. Each volunteer was assigned to 1 of the 3 fluids, and the sample was diluted to 1 of 5 different dilutions (baseline, 10%, 20%, 40%, and 60%). The blood was tested using the gel point technique, which measures clot mechanical strength and quantifies clot microstructure (df) at the incipient stages of fibrin formation. RESULTS: df and clot mechanical strength decrease with progressive dilution for all 3 fluids. A significant reduction in df from baseline was recorded at dilutions of 20% for albumin (P < .0001), 40% for starch (P < .0001), and 60% for gelatin (P < .0001). We also observed significant differences, in terms of df, when comparing the different types of colloid (P < .0001). We found that albumin dilution produced the largest changes in clot microstructure, providing the lowest values of df (= 1.41 ± 0.061 at 60% dilution) compared with starch (1.52 ± 0.081) and gelatin (1.58 ± 0.063). CONCLUSIONS: We show that dilution with all 3 fluids has a significant effect on coagulation at even relatively low dilution volumes (20% and 40%). Furthermore, we quantify, using a novel viscoelastic technique, how the physiochemical properties of the 3 colloids exert individual changes on clot microstructure.

Co-created in vivo pharmacology practical classes using the novel organism Lumbriculus variegatus.

Co-creation within higher education emphasizes learner empowerment to promote collaboration between the students and staff, enabling students to become active participants in their learning process and the construction of resources with academic staff. Concurrently, a diminishing number of higher education institutions offer in vivo practical classes, resulting in an in vivo skills shortage. To address this, and to actively engage students in their own learning, we describe the co-creation of a student-led drug trial using Lumbriculus variegatus. Under blinded conditions, final-year undergraduate biomedical science students, under the tutelage of academic staff and fellow students, were involved in the co-creation of an in vivo practical class to determine the effects of histamine and histamine receptor inverse agonists mepyramine and loratadine. Throughout this process, undergraduate- and masters-level students played key roles in every aspect of practical delivery and data analysis. Herein, students demonstrated the test compounds, both in isolation and in combination, resulted in reduced stereotypical movements of L. variegatus (p < .05, n ≥ 6). 15% of students in the class responded to a feedback survey (n = 8) after the class. Students reported the class provided "real life" insights into in vivo research and enabled the development of hands-on skills which would be useful in applying in their future careers. All students reported that they enjoyed the class with 25% (n = 2) reporting concerns about animal use in research, enabling useful discussions about animals in research. Moreover, these student-led in vivo trials add to the pharmacological knowledge of L. variegatus promoting education-led research.

Inhaled Corticosteroids and Risk of Cardiovascular Disease in Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Regression.

Background: Previous studies have reported mixed associations between inhaled corticosteroids (ICSs) and cardiovascular disease (CVD) in people with chronic obstructive pulmonary disease (COPD). Using updated literature, we investigated the association between ICS-containing medications and CVD in COPD patients, stratified by study-related factors. Methods: We searched MEDLINE and EMBASE for studies that reported effect estimates for the association between ICS-containing medications and the risk of CVD in COPD patients. CVD outcomes specifically included heart failure, myocardial infarction, and stroke-related events. We conducted a random-effects meta-analysis and a meta-regression to identify effect-modifying study-related factors. Results: Fifteen studies met inclusion criteria and investigated the association between ICS-containing medications and the risk of CVD. Pooled results from our meta-analysis showed a significant association between ICS-containing medication and reduced risk of CVD (hazard ratio 0.87, 95% confidence intervals 0.78 to 0.97). Study follow-up time, non-ICS comparator, and exclusion of patients with previous CVD modified the association between ICS use and risk of CVD. Conclusions: Overall, we found an association between ICS-containing medications and reduced risk of CVD in COPD patients. Results from the meta-regression suggest that subgroups of COPD patients may benefit from ICS use more than others and further work is needed to determine this.

Lumbriculus variegatus: A novel organism for in vivo pharmacology education.

Pharmacology graduates require an understanding of both in vitro and in vivo drug responses but there has been a decline in animal use in pharmacology education over the last 30 years. To address this, we present the novel invertebrate model, Lumbriculus variegatus, for in vivo testing of drugs in a teaching environment. We have developed two novel behavioral assays: the stereotypical movement assay, which measures the effect of drugs on the ability of L. variegatus to perform stereotypical movements following tactile stimulation, and the free locomotion assay, which measures drug effects on unstimulated movement. We report the effects of compounds with diverse pharmacodynamic properties on L. variegatus using these assays. The ryanodine receptor antagonist, dantrolene, altered the unstimulated movement of L. variegatus at 5 µM, whereas stimulated movement was inhibited at ≥25 µM. Lidocaine, a voltage-gated sodium channel blocker, and quinine, a nonselective sodium and potassium channel blocker, reduced both stimulated and unstimulated L. variegatus movement at ≥0.5 mM. Inhibitory effects of quinine persisted for up to 24 h after drug removal, whereas lidocaine effects were reduced 10 min after drug removal. Herein, we provide proof-of-concept utilization of L. variegatus as an organism for use in in vivo pharmacology education but without regulatory constraints or the need for specialized equipment and training.

Gastrointestinal nematode control practices in ewes: Identification of factors associated with application of control methods known to influence anthelmintic resistance development.

Gastrointestinal nematodes (GIN) negatively impact productivity and welfare in sheep globally and are estimated to cost the European sheep industry €157-477 million annually. GIN are mainly controlled by anthelmintic treatment, however, as anthelmintic resistance becomes prominent, the routine treatment of ewes against GIN has been questioned. A questionnaire survey of 383 sheep farmers in Great Britain was conducted to identify strategies currently used to control GIN infections in ewes. Ordinal and binary regression analysis were used to identify factors associated with use of practices known to influence anthelmintic resistance development, including number and timing of ewe GIN anthelmintic treatment, targeted selective treatment (TST) of ewes, drench and move of ewes and long-acting moxidectin treatment of periparturient ewes. Participating farmers treated their ewes against GIN 1.68 times per year on average, with 42.3% and 32.1% of participating farmers worming their ewes once or twice a year on average, respectively. 17.2% of participating farmers wormed their ewes more than twice a year, and 8.4% never worm their ewes. Participating farmers who devised GIN control strategies based on SCOPS guidelines treated their ewes significantly less per year (P < 0.001), whilst those determining treatment timing based on ewe DAG scores or the time of year treated their ewes significantly more frequently (P < 0.001). Farmers who devised GIN control strategies in conjunction with their vet had greater odds of using TST (P < 0.001), as well as farmers who determined flock treatment timing based on ewe condition (P = 0.027). The use of narrow spectrum flukicides was significantly associated with reduced number of annual ewe GIN anthelmintic treatments (P < 0.001), TST of ewes against GIN (P < 0.001) and the avoidance of moving ewes to clean pastures following GIN treatment (P < 0.001). The presence of sheep scab on a farm or in the area was significantly associated with increased annual GIN treatments for ewes (P = 0.002), not using TST strategies to control GIN in ewes (P < 0.001) and moving ewes to clean pasture after anthelmintic treatment, whilst using macrocyclic lactones treatments to prevent sheep scab was significantly associated with the treatment of periparturient ewes with long-acting moxidectin (P = 0.001). This research suggests that by encouraging the application of evidence based targeted or targeted selective treatment strategies, further interaction between farmers and veterinarians/SCOPS guidance, and the uptake of best practices for controlling liver fluke and sheep scab on farms, sustainable GIN control strategies can become the common practice in ewes.

Semantic errors in deep dyslexia: does orthographic depth matter?

Semantic errors of oral reading by aphasic patients are said to be comparatively rare in languages with a shallow orthography. The present report concerns three bilingual brain-damaged patients who prior to their stroke were fluent in both English, an orthographically deep language, and Welsh, an orthographically shallow language. On a picture-naming task, each patient made a similar proportion of semantic errors in the two languages. Similarly, in oral reading of the corresponding words, no patient produced proportionally more semantic paralexias in English than in Welsh. The findings are discussed in relation to the summation hypothesis as invoked by Miceli, Capasso, and Caramazza (1994) to explain apparent differences in frequency of semantic errors of reading in languages differing in orthographic depth.

Fractal dimension (df) as a new structural biomarker of clot microstructure in different stages of lung cancer.

Venous thromboembolism (VTE) is common in cancer patients, and is the second commonest cause of death associated with the disease. Patients with chronic inflammation, such as cancer, have been shown to have pathological clot structures with modulated mechanical properties. Fractal dimension (df) is a new technique which has been shown to act as a marker of the microstructure and mechanical properties of blood clots, and can be performed more readily than current methods such as scanning electron microscopy (SEM). We measured df in 87 consecutive patients with newly diagnosed lung cancer prior to treatment and 47 matched-controls. Mean group values were compared for all patients with lung cancer vs controls and for limited disease vs extensive disease. Results were compared with conventional markers of coagulation, fibrinolysis and SEM images. Significantly higher values of df were observed in lung cancer patients compared with controls and patients with extensive disease had higher values than those with limited disease (p< 0.05), whilst conventional markers failed to distinguish between these groups. The relationship between df of the incipient clot and mature clot microstructure was confirmed by SEM and computational modelling: higher df was associated with highly dense clots formed of smaller fibrin fibres in lung cancer patients compared to controls. This study demonstrates that df is a sensitive technique which quantifies the structure and mechanical properties of blood clots in patients with lung cancer. Our data suggests that df has the potential to identify patients with an abnormal clot microstructure and greatest VTE risk.

Exercise-induced immunosuppression: roles of reactive oxygen species and 5'-AMP-activated protein kinase dephosphorylation within immune cells.

We previously proposed 5'-AMP-activated protein kinase (AMPK) dephosphorylation within immune cells as an intracellular mechanism linking exercise and immunosuppression. In this study, AMPK phosphorylation underwent transient (<1 h) decreases (53.8+/-7.2% basal) immediately after exercise (45 min of cycling at 70% VO2max) in a cohort of 16 adult male participants. Similar effects were seen with running. However, because exercise-induced inactivation of AMPK was previously shown to occur in an AMP-independent manner, the means by which AMPK is inactivated in this context is not yet clear. To investigate the hypothesis that exercise-induced inactivation of AMPK is mediated via signaling mechanisms distinct from changes in cellular AMP-to-ATP ratios, reactive oxygen species (ROS) and intracellular Ca2+ signaling were investigated in mononuclear cells before and after exercise and in cultured monocytic MM6 cells. In in vitro studies, treatment with an antioxidant (ascorbic acid, 4 h, 50 microM) decreased MM6 cell intracellular ROS levels (88.0+/-5.2% basal) and induced dephosphorylation of AMPK (44.7+/-17.6% basal). By analogy, the fact that exercise decreased mononuclear cell ROS content (32.8+/-16.6% basal), possibly due to downregulation (43.4+/-8.0% basal) of mRNA for NOX2, the catalytic subunit of the cytoplasmic ROS-generating enzyme NADPH oxidase, may provide an explanation for the AMPK-dephosphorylating effect of exercise. In contrast, exercise-induced Ca2+ signaling events did not seem to be coupled to changes in AMPK activity. Thus we propose that the exercise-induced decreases in both intracellular ROS and AMPK phosphorylation seen in this study constitute evidence supporting a role for ROS in controlling AMPK, and hence immune function, in the context of exercise-induced immunosuppression.