Academic literature on the topic 'Brittains Group'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Brittains Group.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "Brittains Group"
1
Blin-Rolland, Armelle. "A Breton Bande Dessinée? Graphic Mosaics of Brittany." Nottingham French Studies 60, no. 2 (July 2021): 254–71. http://dx.doi.org/10.3366/nfs.2021.0320.
Full textAbstract:
This article uses the figure of the mosaic to explore the multiple ways in which Breton creators of bande dessinée have engaged with cutural, social and political questions from the 1940s to the twenty-first century. Graphic works published in the 1940s magazine O Lo Lê, created by Herri and Ronan Caouissin and later revived in the early 1970s, offered nostalgic images of a fantasized past, a form of cultural propaganda based on myths of Celtic ancestors, literary forefathers such as Auguste Brizeux, and the politics of provincialism. In the second half of the 1970s and early 1980s, amid calls for internal decolonization, the Breton BD scene became more varied, depicting emigration, unemployment and social unrest while giving voice to political dissent and deconstructing the clichés of picturesque localism. Finally, a selection of contemporary texts offers a space for re-examining Frenchness through the interplay between different languages and cultures, new models of relationality informed by postcolonial and ecocritical frameworks. As a hybrid, dynamic art form, BD emerges as a key contributor to the construction and deconstruction of community and group identities.
2
JONES, NEIL S., DOUGLAS W. HOLLIDAY, and JOHN A. McKERVEY. "Warwickshire Group (Pennsylvanian) red-beds of the Canonbie Coalfield, England–Scotland border, and their regional palaeogeographical implications." Geological Magazine 148, no. 1 (June 9, 2010): 50–77. http://dx.doi.org/10.1017/s001675681000035x.
Full textAbstract:
AbstractLate Carboniferous red-beds, < 700 m thick, at outcrop and in the subsurface of the Canonbie Coalfield can be assigned to the Warwickshire Group. They are preserved within the axial part of the Solway Syncline and are divisible into the Eskbank Wood, Canonbie Bridge Sandstone and Becklees Sandstone formations. Sedimentation largely took place on a well-drained alluvial plain, characterized mainly by early, primary oxidation of the strata. Large, northerly-flowing braided river systems were common, with overbank and floodplain fines deposited lateral to the channels; soils formed during intervals of low sediment aggradation. The Canonbie succession includes some of the youngest Carboniferous rocks preserved in the UK. Correlation of the Eskbank Wood Formation is equivocal, but using petrographical, heavy mineral, zircon age dating and palaeocurrent data, the Canonbie Bridge Sandstone Formation can be unambiguously correlated with the Halesowen Formation of Warwickshire, the Pennant Sandstone Formation of South Wales and the offshore Boulton Formation. This suggests that southerly-derived detritus travelled considerable distances from the Variscan highlands of Brittany and/or central Germany across the southern North Sea and UK areas, to a position some hundreds of kilometres north of that previously recognized. The Becklees Sandstone Formation has much in common with the Salop Formation of the English Midlands. It appears to have no preserved equivalent elsewhere in the UK or in the UK sector of the southern North Sea but resembles stratigraphically higher parts of the southern North Sea succession seen in the Dutch sector.
3
NG, HEOK HEE, and MAURICE KOTTELAT. "The identity of the cyprinid fishes Rasbora dusonensis and R. tornieri (Teleostei: Cyprinidae)." Zootaxa 3635, no. 1 (March 25, 2013): 62–70. http://dx.doi.org/10.11646/zootaxa.3635.1.6.
Full textAbstract:
Rasbora dusonensis, R. tornieri and R. myersi are valid species. Rasbora dusonensis sensu Brittan (1954) is R. tornieri and R. dusonensis sensu Kottelat (1991) is R. myersi. Both R. dusonensis and R. tornieri are members of the R. argyrotaenia group and can be distinguished from congeners in having a broad, dark, sharply-defined midlateral stripe on body extending from opercle to caudal-fin base and separated from the dark dorsum by a highly contrasting light longitudinal area; 12–14 predorsal scales; the dorsohypural distance equal to or slightly less than the distance between the dorsal-fin origin and the posterior orbital margin and 14 circumpeduncular scale rows. The two species differ from each other by the color and color pattern on the caudal fin, and caudal peduncle depth.
4
Baltzer, Agnès, Marine Reynaud, Axel Ehrhold, Jérôme Fournier, Céline Cordier, and Hélène Clouet. "Space-time evolution of a large field of pockmarks in the Bay of Concarneau (NW Brittany)." Bulletin de la Société géologique de France 188, no. 4 (2017): 23. http://dx.doi.org/10.1051/bsgf/2017191.
Full textAbstract:
About a decade ago, a large field of pockmarks, covering an overall area of 36 km2 was discovered in water depths of < 30 m in the central part of the Bay of Concarneau (Southern Brittany, France). This field, composed of features from 5 m to 35 m in diameter and < 1 m in depth, is characterized by unusual high densities of pockmarks, up to 5840 per square kilometre. Geophysical data correlated with sedimentary samples acquired in 2005 and 2009 show that pockmarks and their immediate surroundings are associated with dense tubes benches cover, built by a filter-feeding amphipod: Haploops nirae, forming original benthic communities. Two complementary surveys were carried out in April 2011 (Pock and Ploops) and April 2014 (Pock and Tide), on the Oceanographic Vedette (O/V) Haliotis (Ifremer/Genavir), to map the limit of the pockmarks and Haploops fields with the maximum accuracy. The link between the presence of the Haploops nirae communities and the occurrence of pockmarks /gas was then established and the proposed hypothesis was that tidal cycles may provide a good candidate for a short-term (monthly) triggering mechanism of fluid expulsion (Baltzer A, Ehrhold A, Rigolet C, Souron A, Cordier C, Clouet H. 2014. Geophysical exploration of an active pockmark field in the Bay of Concarneau, southern Brittany, and implications for resident suspension feeders. Geo-Marine Letters, 34, 215–230). Due to the high-level precision (50 cm) of the positioning system (Magellan Aquarius Ixsea Hydrins) coupled with the RTK attitude system, these new bathymetric and imagery maps together with the sub-bottom Chirp profiles, allow us to compare the data sets from April 2011 and April 2014. The superimposition of the two data sets shows that the distribution of the pockmarks remains similar between these 2 dates (i.e. for 3 years), for the group of large, widely scattered pockmarks, which are deeply rooted in the Holocene palaeo-valley infills and for the group of pockmarks identified as the trawl-scour pockmarks, initiated by trawling action. Most of the pockmarks present very recent shapes without any infilling but sonar imagery reveals that some of them have been covered by a thin muddy layer, thereby reflecting, at least, a temporary cessation of expulsion or a different activity. Chirp profiles indicate some acoustic flares above the pockmarks, revealing gas/fluid expulsion. Different gas clues within the sedimentary column, such as acoustic turbidity, enhanced gas reflectors (EGR), chimneys pipes, occur at exactly the same places on the chirp seismic profiles from 2011 and 2014. Therefore, contrary to most examples described in the literature, this pockmarks field is still active.
5
Clauer, Norbert, Philippe Vidal, and Bernard Auvray. "Differential behaviour of the Rb-Sr and K-Ar systems of spilitic flows and interbedded metasediments: the spilite group of Erquy (Brittany, France). Paleomagnetic implications." Contributions to Mineralogy and Petrology 89, no. 1 (March 1985): 81–89. http://dx.doi.org/10.1007/bf01177593.
Full text
6
Field, Michael H., Felix Y. Velichkevich, Valerie Andrieu-Ponel, and Phillipe Woltz. "Significance of Two New Pleistocene Plant Records from Western Europe." Quaternary Research 54, no. 2 (September 2000): 253–63. http://dx.doi.org/10.1006/qres.2000.2158.
Full textAbstract:
The first records of extinct Caulinia goretskyi (Dorofeev) Dorofeev (synonym Najas goretskyi Dorofeev) in western Europe and of Potamogeton occidentalis M.H. Field sp. nov. were obtained from plant macrofossil analyses of Middle Pleistocene temperate stage deposits exposed at Trez Rouz, Brittany, France. Palynological assemblages recovered suggest correlation with the Holsteinian Stage. This discovery greatly expands the western limit of the paleogeographical distribution of Caulinia goretskyi. The record of Potamogeton occidentalis indicates an affinity with the eastern Asiatic flora, as the fruits resemble those of the extant Potamogeton maackianus A. Bennett. Other extinct Pleistocene species related to P. maackianus have been described, and it is possible to follow the development of this group through the Pleistocene in the European fossil record. These new finds illustrate the importance of a complete paleobotanical approach (both plant macrofossil and palynological analyses). The plant macrofossil assemblages not only provide detailed insight into local vegetation and environment, because they are often not transported long distances (in temperate areas) and can frequently be identified to species level; they can also offer the opportunity to investigate Pleistocene evolutionary trends.
7
Metges, Jean Philippe, Jean François Ramée, Jean-Yves Douillard, Eveline Boucher, Roger Faroux, Veronique Guerin-Meyer, Isabelle Cumin, et al. "Efficacy and safety of FOLFIRINOX in patients with metastatic pancreatic cancer." Journal of Clinical Oncology 32, no. 3_suppl (January 20, 2014): 305. http://dx.doi.org/10.1200/jco.2014.32.3_suppl.305.
Full textAbstract:
305 Background: FOLFIRINOX, one of the gold standard in metastatic pancreatic cancer as first-line therapy for patients under 76 years with PS 0-1, good haematological and renal function and a subnormal bilirubin level (Prodige 4 criteria), was analysed in Brittany (B) and Pays de la Loire (PL) in routine clinical practice. Methods: Our aim is to evaluate the use of Folfirinox between July 2010 and December 2012 in B/PL. Results: Data of 340 patients have been studied (198 men, median age 63 years [29-81]). 208 patients were metastatic at diagnosis (liver 67%). 62 primary tumors were resected and 51 patients had received previous adjuvant chemotherapy (gemcitabine, n=48). The median progression free survival PFS and overall survival OS were respectively 6.80 months IC95% [6.18-7.43] and 10.97 months IC 95% [9.56-11.83]. Patients could be divided into 4 groups : Group 1 composed of patients treated according to Prodige 4 trial (n=242), Group 2 1st line metastatic patients with at least one Prodige 4 non-eligibility criterion (n=25), Group 3 locally advanced patients (n=59) and Group 4 by Folfirinox in 2ndline (n=14). The median number of cycles was 9 [1-27] in Group 1 and 6 [1-12] in Group 2. Clinical benefit was 65% (group 1) vs 56% (group 2). During treatment, 81% of patients had a dose adjustment (Group 1) vs 72% (Group 2) and 32% vs 40% presented grade III/IV toxicity (mostly neuro- or haematotoxicity). Median PFS were respectively in Group 1 vs Group 2 : 6.54 months IC95% [5.98-7.29] vs 4.14 [1.68-6.21] (p=0.0107) and median OS :10.91 months IC 95% [8.94-12.02] vs 7.0 IC95% [4.01-11.20] (p=0.0166). For Group 3 and 4, median OS were respectively 11.24 months [10.0-15.01] vs 11.50 [4.83-14.09]. Others results will be shown at the meeting. For Group 1, stopping treatment before progression induced significatively better median PFS and OS than going on treatment until progression : PFS : 8.25 IC95[7.52-8.74] vs 3.48. IC95 [3.09-4.44] (p<0.0001) and OS : 12.78 months IC95 [11.60-15.54] vs 7.62 IC95 [6.44-9.49] (p<0.0001). Conclusions: Our results for Group 1 are relatively consistent with those of Prodige 4: objective response rate (39% vs 32%), PFS (6.5 vs 6.4 months) and OS (10.9 vs 11.1 months). Non eligibity for Prodige 4’s criteria decreases PFS and OS significantly.
8
Alexandridis, Nikolaos, Cédric Bacher, Nicolas Desroy, and Fred Jean. "Individual-based simulation of the spatial and temporal dynamics of macroinvertebrate functional groups provides insights into benthic community assembly mechanisms." PeerJ 6 (June 18, 2018): e5038. http://dx.doi.org/10.7717/peerj.5038.
Full textAbstract:
The complexity and scales of the processes that shape communities of marine benthic macroinvertebrates has limited our understanding of their assembly mechanisms and the potential to make projections of their spatial and temporal dynamics. Individual-based models can shed light on community assembly mechanisms, by allowing observed spatiotemporal patterns to emerge from first principles about the modeled organisms. Previous work in the Rance estuary (Brittany, France) revealed the principal functional components of its benthic macroinvertebrate communities and derived a set of functional relationships between them. These elements were combined here for the development of a dynamic and spatially explicit model that operates at two spatial scales. At the fine scale, modeling each individual’s life cycle allowed the representation of recruitment, inter- and intra-group competition, biogenic habitat modification and predation mortality. Larval dispersal and environmental filtering due to the tidal characteristics of the Rance estuary were represented at the coarse scale. The two scales were dynamically linked and the model was parameterized on the basis of theoretical expectations and expert knowledge. The model was able to reproduce some patterns of α- and β-diversity that were observed in the Rance estuary in 1995. Model analysis demonstrated the role of local and regional processes, particularly early post-settlement mortality and spatially restricted dispersal, in shaping marine benthos. It also indicated biogenic habitat modification as a promising area for future research. The combination of this mechanism with different substrate types, along with the representation of physical disturbances and more trophic categories, could increase the model’s realism. The precise parameterization and validation of the model is expected to extend its scope from the exploration of community assembly mechanisms to the formulation of predictions about the responses of community structure and functioning to environmental change.
9
WILSON, BLAKE. "Heinrich Isaac among the Florentines." Journal of Musicology 23, no. 1 (January 1, 2006): 97–152. http://dx.doi.org/10.1525/jm.2006.23.1.97.
Full textAbstract:
ABSTRACT In the archives of the old and wealthy patrician family of the ““da Filicaia”” housed in the Florentine Archivio di Stato survives a group of letters written by, among others, one Ambrogio Angeni to the young Antonio da Filicaia, away on family business in northern Europe for extended periods of time during the 1480s and 1490s. The correspondence details the musical activities of these young men's Florentine brigata and reveals a close involvement with Heinrich Isaac and proximity to Lorenzo de' Medici's private musical circles. The letters document a very active traffic in musical scores, both vernacular works composed in Florence by Isaac and others that were mailed north, as well as sacred and secular works composed in France and sent to Florence. More specifically, the letters contain many musical references to new compositions, works by Isaac, preparations for carnival, aesthetic judgments and technical discussions, Lorenzo's patronage, and a very active local composer previously unknown to musicologists. The correspondence dates from 1487––89, while Antonio was residing in Nantes (Brittany), and it provides an unprecedented view of musical life in Florence at a critical period when carnival celebrations were resurgent, northern repertory was being collected and copied, northern composers (like Isaac) were interacting with local composers, and compositional procedures were changing.
10
Medina Valentin, Anyela Andrea, Alessandra Gavazza, and George Lubas. "Prevalence of Dog Erythrocyte Antigen 1 in 7,414 Dogs in Italy." Veterinary Medicine International 2017 (2017): 1–10. http://dx.doi.org/10.1155/2017/5914629.
Full textAbstract:
The study aim was to establish the prevalence of DEA 1, the most immunogenic and clinically important blood group in canine blood transfusion, in 7,414 dogs from Italy. The potential sensitization risk following a first transfusion and the acute reaction risk following a second transfusion given without a cross-matching and blood typing test were also calculated. Dogs tested were purebred (4,798) and mongrel (2,616); 38.8% were DEA 1 negative and 61.2% were DEA 1 positive. High prevalence for DEA 1 positive blood type was found in Ariegeois and English Setter, whereas German Shepherd and Boxer had higher DEA 1 negative blood type. Breeds with blood type never reported before included French Brittany Spaniel and Pug showing a high prevalence of DEA 1 positive type, while French Bulldog and West Highland White Terrier were more often DEA 1 negative. Just 48.8% of purebred and 13.9% of mongrel dogs were considered as prospective blood donors based upon their blood type. Most of the breeds had a sensitization risk of 20.0–25.0%. Rottweiler and Ariegeois had less risk of sensitization (9.4 and 4.2%) and the minor risk of an acute transfusional reaction (0.9–0.2%). The prevalence of DEA 1 positive and negative dogs in Italy agrees with most of the data already reported in the literature.
Dissertations / Theses on the topic "Brittains Group"
1
Went, David John. "Sedimentology of the lower Palaeozoic Rozel conglomerate formation (Jersey), Alderney sandstone formation and Erquy-Frehel group (northern Brittany)." Thesis, University of Bristol, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.434829.
Full textBooks on the topic "Brittains Group"
1
Coadic, Ronan Le. Bretagne: Le fruit defendu ? Rennes: Presses Universitaires de Rennes, 2002.
Find full text
3
Kennedy, Sue, and Jane Thomas, eds. British Women's Writing, 1930 to 1960. Liverpool University Press, 2020. http://dx.doi.org/10.3828/liverpool/9781789621822.001.0001.
Full textAbstract:
British Women Writers 1930 – 1960: Between the Waves contributes to the vital recuperative work on mid-twentieth century writing by and for women. Fourteen original essays from leading academics and emerging critical voices shed new light on writers commonly dismissed as middlebrow in their concerns and conservative in their styles and politics. The essays showcase the stylistic, cultural and political vitality of the fiction, non-fiction, drama, poetry and journalism of a selection authors including Vera Brittain, Storm Jameson, Nancy Mitford, Phyllis Shand Allfrey, Rumer Godden, Attia Hosain, Doris Lessing, Kamala Markandaya, Susan Ertz, Marghanita Laski, Elizabeth Bowen, Edith Pargeter, Eileen Bigland, Nancy Spain, Vera Laughton Matthews, Pamela Hansford Johnson, Dorothy Whipple, Elizabeth Taylor, Daphne du Maurier, Barbara Comyns, Shelagh Delaney, Stevie Smith and Penelope Mortimer. The neologism ‘interfeminism’, coined to partner Kristin Bluemel’s ‘intermodernism’, locates this group chronologically and ideologically between two ‘waves’ of feminism, whilst forging connections between the political and cultural monoliths which have traditionally overshadowed its members. Drawing attention to the strengths of this ‘out-of-category’ writing, the volume also highlights how intersecting discourses of gender, class and society in the inter- and post- bellum anticipate the bold reassessments of female subjectivity that characterize second and third wave feminism. Exploration of popular women’s magazines of the period, and new archival material, add an innovative dimension to this study of the literature of a volatile and transformative period of British social and cultural history.
Book chapters on the topic "Brittains Group"
1
Vejby, Mara. "Enduring Past: Megalithic Tombs of Brittany and the Roman Occupation in Western France." In The Lives of Prehistoric Monuments in Iron Age, Roman, and Medieval Europe. Oxford University Press, 2015. http://dx.doi.org/10.1093/oso/9780198724605.003.0016.
Full textAbstract:
The extended lives of prehistoric monuments, whether or not they were interacted with once their initial phase of use had ended and how they were treated, can reveal valuable details about a culture. To interact with a place means that the action or influence is reciprocal. The individual, or group of individuals, is somehow affected by the physical contact they’ve had with the site, and the place in turn has been altered. Interactions are more than just reuse of a space. In fact, missing pieces of monuments’ biographies, evidence of subsequent use and treatment, are details that may tell us how a people dealt with their own past as well as that of others. The focus of this study is a region in which the biographies of a group of monuments appear to be intimately tied to clashing cultures during the Roman occupation: Morbihan, Brittany. Brittany is the westernmost province of France, roughly 30 kilometres north-west of the mouth of the Loire river, and extending over 200 kilometres westward into the Celtic Sea. The south-easternmost department of this province is Morbihan, which makes up over 6,800 square kilometres and centres on the Gulf of Morbihan, a few kilometres south of Vannes (Darioritum), the Roman-period civitas-capital of the Veneti. Darioritum was not only a port for commercial ships, but was also on the major road network connecting the Coriosolitae (Corseul), Osismes (Carhaix-Plouguer) and Namnetes (Nantes) civitates (Galliou and Jones 1991, 77, 81, 84). Evidence found in a thorough survey of Iron Age and Roman materials at megalithic tombs in Atlantic Europe revealed that Brittany is by far the region with the highest concentration of direct Roman period interactions, despite both the distribution of megalithic tombs across the peninsula and subsequent habitation patterns during the Iron Age and Roman periods (Scarre 2011, 29–33; Vejby 2012) . It also revealed that this activity is a major shift from the comparatively low number of megalithic tombs at which Iron Age materials have been found.
2
O'Brien, William. "France and The Western Alps." In Prehistoric Copper Mining in Europe. Oxford University Press, 2014. http://dx.doi.org/10.1093/oso/9780199605651.003.0010.
Full textAbstract:
The use of copper was first established in the western Alps during the late fifth/ early fourth millennia BC. There were several metal-using groups in what is now modern Switzerland during the fourth millennium, including the Cortaillod and Pfyn cultures, followed in the third millennium BC by groups of the Saône-Rhône culture (Strahm 1994). The first direct evidence of copper production, however, only dates from the Late Bronze Age. This is based on the dating of smelting slag heaps in the valley of Oberhalbstein in the canton of Graubünden (Fasnacht 2004). These slags derive from the smelting of chalcopyrite ore derived from pillow lavas of the ophiolite geology in that area (Geiger 1984). The ability to smelt iron-rich copper ore involved a furnace technology that seems to have been first developed in the eastern Alps (see Chapter 7). No prehistoric mines are known; however, their existence may be inferred from the smelting of local ore at Late Bronze Age sites such as Savognin-Padnal and Marmorera-Stausees in the Oberhalbstein valley. Potential mining sites have been identified (see Schaer 2003), however, these have yet to be investigated in any detail. There are numerous deposits of copper mineralization in many parts of France. These occur in Brittany, the Pyrenees, the Corbières, on the margins of the Massif Central, the Maures, and the Alps. Research over the past 30 years has identified prehistoric copper mines in several of these areas. Further discoveries are possible in the difficult terrain of the Alps and Pyrenees, and also in areas where early copper mines have not been discovered, such as Brittany where deposits of steam tin and gold are also known. The oldest metal objects in France are recorded in the Paris Basin, where a small number of sheet copper beads date to the second half of the fourth millennium BC. These include the burial at Vignely (Seine-et-Marne) where a necklace of nine such beads was found with the burial of a five-year old child dated to 3499–3123 BC (Allard et al. 1998).
3
Freidberg, Susanne. "France: Expertise and Friendship." In French Beans and Food Scares. Oxford University Press, 2004. http://dx.doi.org/10.1093/oso/9780195169607.003.0007.
Full textAbstract:
Que voulons-nous manger?—What do we want to eat? The French government posed this question in 2000 as part of a Ministry of Agriculture project on l’Etats Generaux de l’Alimentation (EGA), or the “General State of Food.” It also recruited thousands of citizens to respond in surveys, discussion groups, and a national colloquium, which were all duly recorded, analyzed, and interpreted by market researchers. Described as an effort to promote debate and dialogue around the French public’s “true” food concerns, the EGA seemed an extraordinary overture from a government not known for soliciting public opinion on policy matters (Marris 1999). But then, it was an extraordinary time. In the previous five years, mad cows, dioxin chickens, and listeria had found their way into the French food supply; opposition to genetically modified organisms (GMOs) had mushroomed into a major political crisis; a millennial shipwreck off the Brittany coast had dumped huge quantities of potential carcinogens into some of the country’s richest fishing waters. Media coverage of these affairs had played up the roles of government officials who were either corrupt, incompetent, disingenuous, or simply unable or unwilling to address questions about possible food risks (Jaillette 2000; Mamère and Narbonne 2001). The government badly needed to show that it was listening, and that it could protect the public’s health. Yet the EGA findings, while inconclusive in many respects, did show that alleviating public anxieties about the food supply would take more than stricter safety measures (Joly and Marris 2001). For the French were concerned not only about mad cow disease and listeria, but also the loss of their culinary patrimony. In particular, they feared that globalization would force upon them the travesties of “Anglo-Saxon” food culture, from Big Macs to biotech maize. France’s fresh produce importers would probably find the EGA’s findings old but ironic news. After all, the importers had helped to globalize one prominent part of the French diet, namely fresh produce. For much of the past century France, unlike Britain, had produced much of its own fruit and vegetable supply.
Conference papers on the topic "Brittains Group"
1
McCabe, P. J., L. E. Stratton, E. J. Hornby, and M. Foster. "INHIBITION OF GUINEA-PIG PLATELET FUNCTION IN VIVO AND EX VIVO USING THE THROMBOXANE A2 ANTAGONISTS, AH23848 AND GR32191." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643468.
Full textAbstract:
The thromboxane A2 antagonist, GR32191 (Lumley et al., this meeting) was tested as an inhibitor of platelet aggregation in the guinea-pig and compared with another Tx-antagonist, AH23848 (Brittain et al, 1985). Guinea-pigs were dosed with AH23848 or GR32191 at 0.01-1.0mg/kg. At intervals, blood was taken and PRP was prepared for ex vivo aggregation studies. Collagen concentrations causing half maximal aggregation (IC50) were calculated for test and vehicle-dosed groups. Inhibition was expressed as a concentration ratio (IC50 test/IC50 vehicle). For in vivo studies, 111In-labelled platelets (12μCi, 200μl) were injected into anaesthetised guinea-pigs and 24 hrs later oral doses of AH23848 or GR32191 (0.01-1.0mg/kg) or indomethacin (5mg/kg) were given. After one hour, blood was taken for platelet and radioactivity counting. The carotid artery was exposed under anaesthesia and a current of 2mA was applied for 60 sec. After 90 min, 1cm of the damaged and contralateral carotid vessels were removed for gamma-counting. Inhibition of accumulation of platelets on the injured artery was measured by comparison with the undamaged contralateral artery. Numbers of platelets deposited were calculated from the radioactivity of each section of artery and the radioactivity and platelet count in the blood. Oral doses of AH23848 or GR32191 inhibited ex vivo platelet aggregation induced by collagen. Maximum inhibition occurred one hour after dosing, and was still present at 6 hours for AH23848 (l.Omg/kg) and GR32191 (0.3mg/kg). GR32191 and AH23848 were active in vivo causing inhibition of platelet deposition at doses of 0.01-lmg/kg. The maximum inhibition of deposition was 58% for AH23848 (0.1mg/kg) and 63% for GR32191 (0.1mg/kg), with 50% inhibition at 0.02mg/kg for both. Indomethacin (5mg/kg p.o.) caused maximum inhibition of 58% at 5mg/kg p.o. suggesting that this represents the total thromboxane involvement in platelet deposition. GR32191 and AH23848 are thromboxane A2 antagonists with antithrombotic activity after oral dosing to guinea-pigs.Brittain R.T. et al Circulation, 72, 1208-1218, 1985.