Morphological alterations of blood platelets induced by Platelet Activating Factor (PAF) and partial inhibition by Ketoprofen in calves

in Veterinary Research (1997), 28(5 Sep-Oct), 489-502

The influence of platelet activating factor (PAF) was investigated in vivo on the ultrastructure of bovine platelets, and on the platelet count. The effect of an intravenous administration of ketoprofen ... [more ▼]

The influence of platelet activating factor (PAF) was investigated in vivo on the ultrastructure of bovine platelets, and on the platelet count. The effect of an intravenous administration of ketoprofen (a non-steroidal anti-inflammatory drug) pretreatment followed by PAF infusion was also observed in a group of six healthy male Friesian calves. PAF infusion alone caused a moderate thrombocytopenia, which peaked one minute post challenge and returned to levels not significantly different from control after 30 min. Electron microscopy revealed that after PAF infusion, platelets lost their lentiform shape and became irregular, with many pseudopods. Their microtubules became impossible to distinguish. The numbers of alpha granules and dense bodies were significantly decreased. Glycogen particles became rare or even disappeared. Giant platelets occasionally appeared. The Golgi apparatus was more often visible and the number of mitochondria was significantly increased. Ketoprofen pretreatment lowered PAF-induced thrombocytopenia and decrease in the number of dense bodies. Under these conditions, the Golgi apparatus was rarely visible and giant platelets were not observed. These results showed that the morphological ultrastructure of blood platelets in bovines were modified following PAF infusion and that ketoprofen pretreatment before PAF infusion provided partial protection, limiting the extent of the morphological alterations and maintaining a normal platelet count [less ▲]

Morphological analysis of overproduction of hair cells and Deiters'cells in the E19 rat organ of Corti

in Acta Oto-Rhino-Laryngologica Belgica (2002), 56

Morphological and allozyme variation in a collection of Lagenaria siceraria (Molina) Standl. from Côte d'Ivoire

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2009), 13(2), 257-281

Morphological and ecological complexity in early eukaryotic ecosystems

in Nature (2001), 412(6842), 66-69

Molecular phylogeny and biogeochemistry indicate that eukaryotes differentiated early in Earth history. Sequence comparisons of small-subunit ribosomal RNA genes suggest a deep evolutionary divergence of ... [more ▼]

Molecular phylogeny and biogeochemistry indicate that eukaryotes differentiated early in Earth history. Sequence comparisons of small-subunit ribosomal RNA genes suggest a deep evolutionary divergence of Eukarya and Archaea(1); C-27-C-29 steranes (derived from sterols synthesized by eukaryotes) and strong depletion of C-13 (a biogeochemical signature of methanogenic Archaea) in 2,700 Myr old kerogens independently place a minimum age on this split(2,3). Steranes, large spheroidal microfossils, and rare macrofossils of possible eukaryotic origin occur in Palaeoproterozoic rocks(4-6). Until now, however, evidence for morphological and taxonomic diversification within the domain has generally been restricted to very late Mesoproterozoic and Neoproterozoic successions(7). Here we show that the cytoskeletal and ecological prerequisites for eukaryotic diversification were already established in eukaryotic microorganisms fossilized nearly 1,500 Myr ago in shales of the early Mesoproterozoic Roper Group in northern Australia. [less ▲]

Morphological and genetic divergences in a coral reef damselfish, Pomacentrus coelestis

in Evolutionary Biology (2012), 39(3), 359-370

Population differentiation is one of the main topics in evolutionary biology. Except the exploration of color variation, few studies focused on morphological divergences among populations of coral reef ... [more ▼]

Population differentiation is one of the main topics in evolutionary biology. Except the exploration of color variation, few studies focused on morphological divergences among populations of coral reef fishes. In this work, we studied morphological and genetic differentiation among populations of the damselfish, Pomacentrus coelestis, in the northwestern Pacific Ocean. The shapes of the mandible and the premaxilla were explored using geometric morphometric methods and the genetic structure was investigated using microsattelites. Various tests revealed significant shape variation among most P. coelestis populations for both skeletal units. Morphological variation of the mandible accompanies a genetic break between populations of mainland Japan and Okinawa-Taiwan. However, Mantel and Procrustes tests revealed no congruence between morphological and genetic structures. We illustrate that phenotypic plasticity and adaptive divergence are potential evolutionary mechanisms underlying shape difference among P. coelestis populations. An ecomorphological approach suggests that various diet could be related to shape variation of oral jaws. [less ▲]

Morphological and histological studies of sheep’s brain

Poster (2010)

Introduction: The study of normal structures of the sheep’s brain is very important to understand pathological changes caused by the bluetongue virus in the fetus’s brain at various stages of the ... [more ▼]

Introduction: The study of normal structures of the sheep’s brain is very important to understand pathological changes caused by the bluetongue virus in the fetus’s brain at various stages of the gestation. Bluetongue is an arthropod-borne viral disease of domestic and wild ruminants. The serotype 8 is responsible for outbreaks in Northern Europe in 2006. This virus causes lesions in the brain of fetuses as hydrancephaly and porencephaly. The aim of this work is to improve knowledge of anatomy and histology of the central nervous system of the sheep. Methods: Seven heads of adult sheep and one from a fetus aged 4,5 months were used. All heads were first opened in the frontal area using bone’s saw and immerged in a formalin solution for 10 days. After a good fixation, the brains were extracted and sectioned. Transversal, frontal and sagittal sections were realized. The sections of two brains were stained with Berlin-blue and treated to be embedded in methylmetacrylate for gross morphology. The different parts of the 6 resting brains were then embedded in paraffin, cut and the histological sections were stained with haematoxylin/eosin, cresyl violet or by use of silver impregnation. Results: Gross morphological examination of the brains embedded in methylmetacrylate showed the detailed anatomy of the different parts. The staining with haematoxylin/eosin permitted to differentiate the grey matter, the different nucleus and the layers of cerebral and cerebellum cortex. The cresyl violet technique permitted to visualize the Nissl bodies and the silver impregnation revealed nerve fibers. In the fetus brain, blood vessels were very numerous in the brainstem, the cerebellum and the cerebrum. The grey matter was less organized and looser. Conclusion: This work establishes an anatomical and histological approach allowing future studies in ovine fetuses with and without brain lesions potentially caused by the bluetongue virus. [less ▲]

Morphological and molecular characterization of planktonic cyanobacteria from Belgium and Luxembourg

in Journal of Phycology (2006), 42(6), 1312-1332

For the first time in Belgium and Luxembourg, the diversity and taxonomy of 95 cyanobacterial strains isolated from freshwater blooms were assessed by the comparison of phenotypes and partial 16S rRNA ... [more ▼]

For the first time in Belgium and Luxembourg, the diversity and taxonomy of 95 cyanobacterial strains isolated from freshwater blooms were assessed by the comparison of phenotypes and partial 16S rRNA gene sequences. The results showed the high diversity of nanoplanktonic, picoplanktonic, and benthic-periphytic cyanobacteria accompanying the main bloom-forming taxa. Indeed, besides 15 morphotypes of bloom-forming taxa, seven non-bloom-forming planktonic morphotypes and 11 morphotypes from benthic-periphytic taxa were isolated in culture from the plankton samples of 35 water bodies. The bloom-forming strains belonged to the genera Microcystis, Woronichinia, Planktothrix, Anabaena, and Aphanizomenon, whereas the other strains isolated from the same samples were assigned to the nanoplanktonic Aphanocapsa, Aphanothece, Snowella, and Pseudanabaena; to the picoplanktonic Cyanobium; and to the benthic periphytic Geitlerinema, Komvophoron, Leptolyngbya, Lyngbya, Phormidium, Calothrix, Nostoc, and Trichormus. The results supported both the polyphyletism of genera such as Aphanocapsa, Aphanothece, Leptolyngbya, Geitlerinema, Anabaena, and Aphanizomenon as well as the validity of genera such as Microcystis, Planktothrix, and Pseudanabaena with gas vesicles and cells constricted at the cross wall. The results obtained showed the close relationship between Snowella and Woronichinia for which very few sequences exist. The first sequence of Komvophoron appeared poorly related to other available cyanobacterial sequences. Although in a few cases a good agreement existed between phenotypic and genotypic features, there was generally a discrepancy. Strains with identical morphotypes show small differences in the 16S rRNA sequences, which might be related to the different chemical properties of their habitats. The results showed the importance of the polyphasic approach in order to improve the taxonomy of cyanobacteria. [less ▲]

Morphological and molecular diversity within Algerian cowpea (Vigna unguiculata (L.) Walp.) landraces

in Genetic Resources and Crop Evolution (2009)

Morphological and molecular studies of Sphaerospermopsis torques-reginae comb. nov. (Nostocales, Cyanobacteria) from South American water blooms

in Phycologia (2012), 51(2), 228-238

Morphological Biomarkers

in Gargaud et al (Ed.) Encyclopedia of Astrobiology (2011)