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1.
Sci Rep ; 10(1): 19602, 2020 11 11.
Article in English | MEDLINE | ID: mdl-33177568

ABSTRACT

For over a century, researchers have assumed that the plane of the lateral semicircular canal of the inner ear lies parallel to the horizon when the head is at rest, and used this assumption to reconstruct head posture in extinct species. Although this hypothesis has been repeatedly questioned, it has never been tested on a large sample size and at a broad taxonomic scale in mammals. This study presents a comprehensive test of this hypothesis in over one hundred "ungulate" species. Using CT scanning and manual segmentation, the orientation of the skull was reconstructed as if the lateral semicircular canal of the bony labyrinth was aligned horizontally. This reconstructed cranial orientation was statistically compared to the actual head posture of the corresponding species using a dataset of 10,000 photographs and phylogenetic regression analysis. A statistically significant correlation between the reconstructed cranial orientation and head posture is found, although the plane of the lateral semicircular canal departs significantly from horizontal. We thus caution against the use of the lateral semicircular canal as a proxy to infer precisely the horizontal plane on dry skulls and in extinct species. Diet (browsing or grazing) and head-butting behaviour are significantly correlated to the orientation of the lateral semicircular canal, but not to the actual head posture. Head posture and the orientation of the lateral semicircular canal are both strongly correlated with phylogenetic history.


Subject(s)
Head , Mammals/physiology , Semicircular Canals/physiology , Animal Nutritional Physiological Phenomena , Animals , Artiodactyla/anatomy & histology , Artiodactyla/physiology , Body Weight , Databases, Factual , Female , Male , Mammals/anatomy & histology , Perissodactyla/anatomy & histology , Perissodactyla/physiology , Photography , Posture , Skull
2.
J Comp Pathol ; 168: 35-40, 2019 Apr.
Article in English | MEDLINE | ID: mdl-31103057

ABSTRACT

A mature, adult female, offshore killer whale (Orcinus orca) was stranded deceased in Portage Bay, Alaska, in October 2015. Full necropsy examination with histopathology was performed. Consistent with previous studies of offshore killer whales, and thought to be a result of their unique elasmobranch diet, all the teeth were significantly abraded and almost flush with the gingival margin. Age was estimated at 30-35 years based on annuli and growth arrest lines in a remaining tooth. The dentate portion of the mandibles were excised en bloc and frozen until imaging could be completed. Radiography and computed tomography revealed lesions consistent with severe abrasion, pulp exposure and evidence of endodontic and/or periodontal disease in nine of the 15 mandibular teeth present (60.0%). Only five (33.3%) teeth were suspected to have been vital at the time of death based on imaging. Lesions were more severe rostrally, with the caudal teeth less affected. Autolysis precluded gingival histopathology and no teeth were analyzed histologically. Necropsy examination revealed a likely multifactorial cause of death, with most significant lesions including the severe chronic periodontal/endodontic disease with abrasion, inanition and emaciation with possible cardiovascular disease. This case highlights the importance of imaging in evaluating periodontal and endodontic status, especially post mortem when other tissues are no longer available, and demonstrates that periodontal and endodontic disease occur naturally in this species and can be a significant cause of morbidity in mature free-ranging killer whales of the offshore ecotype.


Subject(s)
Mandible/pathology , Periodontal Diseases/veterinary , Tooth Diseases/veterinary , Whale, Killer , Animals , Female , Tomography, X-Ray Computed
3.
Ann Dermatol Venereol ; 143(12): 831-835, 2016 Dec.
Article in French | MEDLINE | ID: mdl-27663385

ABSTRACT

BACKGROUND: Linear scleroderma is a fibrotic disease affecting the skin and sometimes the deeper tissues. We describe a case of scleroderma associated with neurological anomalies not previously reported in the literature. PATIENTS AND METHODS: A 16-year-old male patient presented in 2009 for hemifacial linear scleroderma. Treatment with methotrexate for 14 months resulted in stabilization of the disease. In 2013, we noted worsening of the patient's skin lesions as well as homolateral ptosis. Head MRI revealed unilateral hemispherical signal abnormalities with T2 hypersignal in the basal gangliaand punctate foci of T2* hyposignal corresponding to microbleeds. In 2014 and 2015, the patient presented three brief episodes of right hemicorpus paresthesia (with temporary aphasia followed by headache during the first episode). The head MRI showed worsening of the anomalies, suggesting progressing cerebral microangiopathy. DISCUSSION: Clinicians may not always be familiar with the neurological abnormalities associated with localized facial scleroderma even if such abnormalities are not uncommon (their exact prevalence is unknown). Clinical signs vary but, in most cases, the radiological features are calcifications and hyperintense foci of white matter lesions in T2. As far as we are aware, there have been no reports to date of microbleeding as observed in our patient. The worsening with time of these neurological anomalies of unknown origin does not appear to be correlated with the dermatological lesions. It is important for dermatologists be aware of these complications of facial linear scleroderma.


Subject(s)
Cerebral Small Vessel Diseases/complications , Facial Dermatoses/complications , Scleroderma, Localized/complications , Adolescent , Blepharoptosis/etiology , Cerebral Small Vessel Diseases/diagnosis , Humans , Magnetic Resonance Imaging , Male , Paresthesia/etiology
4.
Ann Dermatol Venereol ; 143(5): 369-71, 2016 May.
Article in French | MEDLINE | ID: mdl-27021901

ABSTRACT

BACKGROUND: Harlequin phenomenon consists of facial flush and erythrosis with unilateral sweating and pallor, associated with contralateral anhidrosis. We present the case of a child in whom the syndrome was associated with Horner's syndrome, epilepsy, mental and psychomotor retardation. PATIENTS AND METHODS: A 9-year-old boy presented with right unilateral hemifacial erythema on effort, with normal colouring and Horner's syndrome on the left side of the face. His medical history revealed generalized myoclonic epilepsy, psychomotor delay and mental retardation. No underlying anomalies were identified. Harlequin phenomenon was diagnosed. DISCUSSION: Despite its stereotypical clinical features, Harlequin phenomenon is a poorly known disease. However, clinicians must be aware of it in order to determine the diagnosis and investigate for causes and any associated abnormalities. The underlying mechanism is an autonomic neuropathy affecting the sympathetic vasodilator neurons. To our knowledge, there have been no previous reports of Harlequin phenomenon in association with Horner syndrome, psychomotor delay and mental retardation.


Subject(s)
Autonomic Nervous System Diseases/complications , Flushing/complications , Horner Syndrome/complications , Hypohidrosis/complications , Child , Epilepsy/complications , Humans , Intellectual Disability/complications , Male , Pallor/complications
5.
Food Chem ; 151: 554-60, 2014 May 15.
Article in English | MEDLINE | ID: mdl-24423570

ABSTRACT

Kava (Piper methysticum) is used to prepare the traditional beverage of the Pacific islands. In Europe, kava has been suspected to cause hepatoxicity with flavokavin B (FKB) considered as a possible factor. The present study describes an HPTLC protocol for rapid screening of samples. The objectives are: to detect the presence of flavokavins in extracts and to compare the FKB levels in different cultivars. Overall, 172 samples originating from four cultivars groups (noble, medicinal, two-days and wichmannii), were analysed. Results indicate that the ratio FKB/kavalactones is much higher in two-days (0.39) and wichmannii (0.32) compared to nobles (0.09) and medicinal cultivars (0.10). For each group, the ratios flavokavins/kavalactones do not change significantly between roots, stumps or basal stems and among clones, indicating that they are genetically controlled. This protocol has good accuracy and is cost efficient for routine analysis. We discuss how it could be used for quality control.


Subject(s)
Chalcone/analogs & derivatives , Chromatography, Thin Layer/methods , Flavonoids/analysis , Kava/chemistry , Beverages/analysis , Chalcone/analysis , Food Quality , Pacific Islands , Plant Roots/chemistry , Quality Control
6.
J Evol Biol ; 25(2): 293-303, 2012 Feb.
Article in English | MEDLINE | ID: mdl-22107024

ABSTRACT

Ever since Eldredge and Gould proposed their model of punctuated equilibria, evolutionary biologists have debated how often this model is the best description of nature and how important it is compared to the more gradual models of evolution expected from natural selection and the neo-Darwinian paradigm. Recently, Cubo proposed a method to test whether morphological data in extant ratites are more compatible with a gradual or with a speciational model (close to the punctuated equilibrium model). As shown by our simulations, a new method to test the mode of evolution of characters (involving regression of standardized contrasts on their expected standard deviation) is easier to implement and more powerful than the previously proposed method, but the Mesquite module comet (aimed at investigating evolutionary models using comparative data) performs better still. Uncertainties in branch length estimates are probably the largest source of potential error. Cubo hypothesized that heterochronic mechanisms may underlie morphological changes in bone shape during the evolution of ratites. He predicted that the outcome of these changes may be consistent with a speciational model of character evolution because heterochronic changes can be instantaneous in terms of geological time. Analysis of a more extensive data set confirms his prediction despite branch length uncertainties: evolution in ratites has been mostly speciational for shape-related characters. However, it has been mostly gradual for size-related ones.


Subject(s)
Genetic Speciation , Models, Biological , Palaeognathae/genetics , Animals , Computer Simulation , Likelihood Functions , Palaeognathae/anatomy & histology , Phylogeny , Regression Analysis
7.
Plant Biol (Stuttg) ; 8(6): 748-57, 2006 Nov.
Article in English | MEDLINE | ID: mdl-17203430

ABSTRACT

Carnivorous plants have emerged as model systems for addressing many ecological and evolutionary questions, and since Lentibulariaceae comprise more than half of all known carnivorous species (325 spp.), they are of particular interest. Studies using various molecular markers have established that Lentibulariaceae and their three genera are monophyletic with Pinguicula being sister to a Genlisea-Utricularia-clade, while the closest relatives of the family remain uncertain. Character states of the carnivorous syndrome in related proto-carnivorous lamialean families apparently emerged independently. In Utricularia, the terrestrial habit has been reconstructed as plesiomorphic, and an extension of subgenus Polypompholyx is warranted. In the protozoan-attracting Genlisea, subgenus Tayloria is revealed as basal lineage. In Pinguicula, the six major lineages found reflect radiations in clearly defined geographic regions, whereas most previously recognized subgeneric taxa are non-monophyletic. Genlisea and Utricularia exhibit substitutional rates that rank among the highest in angiosperms for the molecular markers analyzed. One possible explanation for this lies in selective constraints on a wide range of genomic regions that may have been lowered due to the use of an alternative mode of acquiring nutrients.


Subject(s)
Evolution, Molecular , Magnoliopsida/physiology , Animals , Insecta/physiology , Magnoliopsida/classification , Magnoliopsida/genetics , Phylogeny
8.
Plant Biol (Stuttg) ; 6(4): 477-90, 2004 Jul.
Article in English | MEDLINE | ID: mdl-15248131

ABSTRACT

As a basis for analysing the evolution of the carnivorous syndrome in Lentibulariaceae (Lamiales), phylogenetic reconstructions were conducted based on coding and non-coding chloroplast DNA (matK gene and flanking trnK intron sequences, totalling about 2.4 kb). A dense taxon sampling including all other major lineages of Lamiales was needed since the closest relatives of Lentibulariaceae and the position of "proto-carnivores" were unknown. Tree inference using maximum parsimony, maximum likelihood, and Bayesian approaches resulted in fully congruent topologies within Lentibulariaceae, whereas relationships among the different lineages of Lamiales were only congruent between likelihood and Bayesian optimizations. Lentibulariaceae and their three genera (Pinguicula, Genlisea, and Utricularia) are monophyletic, with Pinguicula being sister to a Genlisea-Utricularia clade. Likelihood and Bayesian trees converge on Bignoniaceae as sister to Lentibulariaceae, albeit lacking good support. The "proto-carnivores" (Byblidaceae, Martyniaceae) are found in different positions among other Lamiales but not as sister to the carnivorous Lentibulariaceae, which is also supported by Khishino-Hasegawa tests. This implies that carnivory and its preliminary stages ("proto-carnivores") independently evolved more than once among Lamiales. Ancestral states of structural characters connected to the carnivorous syndrome are reconstructed using the molecular tree, and a hypothesis on the evolutionary pathway of the carnivorous syndrome in Lentibulariaceae is presented. Extreme DNA mutational rates found in Utricularia and Genlisea are shown to correspond to their unusual nutritional specialization, thereby hinting at a marked degree of carnivory in these two genera.


Subject(s)
Biological Evolution , Magnoliopsida/genetics , Magnoliopsida/physiology , Animals , Base Sequence , DNA, Plant/genetics , Genetic Variation , Introns , Magnoliopsida/anatomy & histology , Magnoliopsida/classification , Nutritional Physiological Phenomena , Phylogeny
9.
Cytometry ; 44(3): 164-72, 2001 Jul 01.
Article in English | MEDLINE | ID: mdl-11429766

ABSTRACT

BACKGROUND: The present review is based on the identification of four major environmental crises that have been approached from a biological oceanographic viewpoint. These crises are the release of contaminants in near shore marine waters, the collapse of marine resources that were renewable until recently, the loss of biodiversity, and global climate change METHODS: The review examines the contribution of cytometry-based biological oceanography to the resolution of the four environmental crises. Using a database of 302 papers, flow cytometric (FCM) studies in biological oceanography over the 1989--1999 decade are examined. Future biological oceanographic applications of FCM are discussed. RESULTS: Most of the published FCM oceanographic studies focus on phytoplankton and bacterioplankton. Analysis of our 1989-1999 database shows the predominance of studies dedicated to phytoplankton (77%), followed by heterotrophic bacteria (21%). The latter progressively increased over the last decade, together with the improved understanding of the biogeochemical and trophic roles of marine bacteria. Most studies on these two microorganisms were conducted in vitro until 1996, after which the trend reversed in favor of in situ research. The most investigated areas were those with major international sampling efforts, related to the changing climate. Concerning environmental topics, 62% of papers on phytoplankton and bacterioplankton focused on the structure of microbial communities and fluxes (e.g., production, grazing); this provides the basis for biological oceanographic studies on resources and climate change. CONCLUSIONS: Future progress in the biological oceanographic use of FCM will likely fall into two categories, i.e., applications where FCM will be combined with the development of other methods and those where FCM will be the main analytical tool. It is expected that FCM and other cytometric approaches will improve the ability of biological oceanography to address the major environmental challenges that are confronting human societies.


Subject(s)
Flow Cytometry/trends , Research/trends , Animals , Environment , Forecasting , Humans , Oceans and Seas
10.
Science ; 291(5512): 2398-400, 2001 Mar 23.
Article in English | MEDLINE | ID: mdl-11264533

ABSTRACT

Food-web processes are important controls of oceanic biogenic carbon flux and ocean-atmosphere carbon dioxide exchange. Two key controlling parameters are the growth efficiencies of the principal trophic components and the rate of carbon remineralization. We report that bacterial growth efficiency is an inverse function of temperature. This relationship permits bacterial respiration in the euphotic zone to be computed from temperature and bacterial production. Using the temperature-growth efficiency relationship, we show that bacterial respiration generally accounts for most community respiration. This implies that a larger fraction of assimilated carbon is respired at low than at high latitudes, so a greater proportion of production can be exported in polar than in tropical regions. Because bacterial production is also a function of temperature, it should be possible to compute euphotic zone heterotrophic respiration at large scales using remotely sensed information.


Subject(s)
Bacteria/growth & development , Bacteria/metabolism , Carbon Dioxide/metabolism , Carbon/metabolism , Seawater/microbiology , Atmosphere , Biomass , Ecosystem , Food Chain , Oceans and Seas , Oxygen Consumption , Temperature
11.
J Biol Chem ; 276(9): 6789-96, 2001 Mar 02.
Article in English | MEDLINE | ID: mdl-11096112

ABSTRACT

We have identified a yeast nuclear gene (FMC1) that is required at elevated temperatures (37 degrees C) for the formation/stability of the F(1) sector of the mitochondrial ATP synthase. Western blot analysis showed that Fmc1p is a soluble protein located in the mitochondrial matrix. At elevated temperatures in yeast cells lacking Fmc1p, the alpha-F(1) and beta-F(1) proteins are synthesized, transported, and processed to their mature size. However, instead of being incorporated into a functional F(1) oligomer, they form large aggregates in the mitochondrial matrix. Identical perturbations were reported previously for yeast cells lacking either Atp12p or Atp11p, two specific assembly factors of the F(1) sector (Ackerman, S. H., and Tzagoloff, A. (1990) Proc. Natl. Acad. Sci. U. S. A. 87, 4986--4990), and we show that the absence of Fmc1p can be efficiently compensated for by increasing the expression of Atp12p. However, unlike Atp12p and Atp11p, Fmc1p is not required in normal growth conditions (28--30 degrees C). We propose that Fmc1p is required for the proper folding/stability or functioning of Atp12p in heat stress conditions.


Subject(s)
Chaperonins , Genes, Fungal , Hot Temperature , Mitochondria/enzymology , Mitochondrial Proton-Translocating ATPases , Molecular Chaperones , Proton-Translocating ATPases/chemistry , Saccharomyces cerevisiae Proteins , Saccharomyces cerevisiae/genetics , Schizosaccharomyces pombe Proteins , Fungal Proteins/physiology , Mitochondrial Proteins , Oxygen Consumption , Protein Folding , Proton-Translocating ATPases/physiology , Saccharomyces cerevisiae/enzymology
12.
Can Vet J ; 40(11): 821-5, 1999 Nov.
Article in English | MEDLINE | ID: mdl-10563248
13.
Phytopathology ; 89(3): 197-203, 1999 Mar.
Article in English | MEDLINE | ID: mdl-18944759

ABSTRACT

ABSTRACT Even though Botrytis cinerea, the causal agent of gray mold, is a highly variable fungus with strains displaying very different degrees of virulence toward one given host plant species, no study has yet shown any correlation between the lack of aggressiveness of one given strain and its ability to stimulate a defense response from its host. Strains of B. cinerea collected from different host plant species were screened for their pathogenicity on grapevine to select two strains with similar morphological characteristics but different levels of virulence. In grapevine leaves, the less aggressive strain, T4, enhanced the accumulation of many defense products including secondary metabolites and the pathogenesis-related proteins, chitinase and beta-1,3-glucanase. Interestingly, secondary metabolites were formed in cells around a small group of dead cells. When compared with T4, the more aggressive strain, T8, had larger necrotic spots, no secondary metabolite biosynthesis, and accumulations of chitinases and beta-1,3-glucanases that were more delayed, yet only slightly weaker. The culture fluids of both strains mimicked the differential effect of each isolate in stimulating chitinase activity when infiltrated into grapevine leaves.

14.
J Vet Dent ; 15(4): 179-81, 1998 Dec.
Article in English | MEDLINE | ID: mdl-10518875

ABSTRACT

A compression fracture of the maxilla in a young cat was treated by splinting the maxillary canine teeth. Wire-reinforced composite resin was used to keep these teeth from tipping palatally. This technique stabilized the fracture with anatomic reduction and minimal invasion of the tissues. A mandibular symphyseal separation was also stabilized with a cerclage wire and composite resin bonded wire fixation of the mandibular canine teeth. Two years later, occlusion was normal.


Subject(s)
Cats/injuries , Fracture Fixation/veterinary , Maxillary Fractures/veterinary , Splints/veterinary , Animals , Dental Occlusion , Male , Maxillary Fractures/therapy
17.
Science ; 272(5265): 1163-6, 1996 May 24.
Article in English | MEDLINE | ID: mdl-8662452

ABSTRACT

Models of biogenic carbon (BC) flux assume that short herbivorous food chains lead to high export, whereas complex microbial or omnivorous food webs lead to recycling and low export, and that export of BC from the euphotic zone equals new production (NP). In the Gulf of St. Lawrence, particulate organic carbon fluxes were similar during the spring phytoplankton bloom, when herbivory dominated, and during nonbloom conditions, when microbial and omnivorous food webs dominated. In contrast, NP was 1.2 to 161 times greater during the bloom than after it. Thus, neither food web structure nor NP can predict the magnitude or patterns of BC export, particularly on time scales over which the ocean is in nonequilibrium conditions.

19.
Biochim Biophys Acta ; 1289(2): 231-7, 1996 Mar 15.
Article in English | MEDLINE | ID: mdl-8600979

ABSTRACT

Generation of the microbicidal oxidative burst in human neutrophils requires participation of four proteins, a membrane bound flavocytochrome beta-558, two soluble proteins termed p47-phox and p67-phox, and the Ras-related GTPase Rac. Because plant cells exposed to pathogens produce a similar oxidative burst, we have looked for similarities between the oxidase complexes of the two systems. Antibodies against human neutrophil p47-phox and p67-phox were used to immunoblot cell extracts from several plant cell lines and were found to cross-react with proteins of the same molecular weight. Furthermore, plant cell lines not previously shown to produce an oxidative burst, yet found to express these immunoreactive proteins, rapidly generated hydrogen peroxide in response to elicitation. Finally, diphenylene iodonium (DPI) and alpha-naphthol, known specific inhibitors of the NADPH oxidase in neutrophils, also inhibited the oxidative burst in soybean cell suspensions with similar Ki values (about 15 microM and 30 microM respectively). These results provide evidence for involvement of proteins related to the neutrophil oxidase complex in the defense-related oxidative burst of plants.


Subject(s)
NADPH Dehydrogenase/analysis , Neutrophils/metabolism , Phosphoproteins/analysis , Plants/metabolism , Respiratory Burst , Cells, Cultured , Humans , NADPH Oxidases , Onium Compounds/pharmacology
20.
Plant Physiol ; 109(4): 1259-1266, 1995 Dec.
Article in English | MEDLINE | ID: mdl-12228667

ABSTRACT

Rapid release of H2O2 may constitute an initial defense response mounted by a plant. Inauguration of this oxidative burst is known to occur upon stimulation with chemical elicitors, but the possibility of mechanical elicitation arising from pathogen penetration/weakening of the cell wall has never been examined. To introduce an adjustable mechanical stress on the plasma membrane, cultured soybean (Glycine max Merr. cv Kent) cells were subjected to defined changes in medium osmolarity. Dilution of the medium with water or resuspension of cells in sucrose solutions of reduced osmolarity yielded an oxidative burst similar to those stimulated by chemical elicitors. Furthermore, the magnitude of oxidant biosynthesis and osmotic stress correlated directly. Upon return of the cells to normal tonicity, the oxidative burst abruptly halted, indicating that its expression depended on maintenance of the osmotic stress and not on any external chemical signal. To confirm the ability of soybean cells to respond to a mechanical stimulus with induction of an oxidative burst, cells were subjected to direct physical pressure. Application of pressure yielded a characteristic oxidative burst. Because neither these cells nor those subjected to osmotic pressure were damaged by their treatments, we conclude that plant cells can detect mechanical disturbances and initiate a classical defense reaction in response.

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