Augmented visual feedback of movement performance to enhance walking recovery after stroke: study protocol for a pilot randomised controlled trial

ABSTRACT: BACKGROUND: Increasing evidence suggests that use of augmented visual feedback could be a useful approach to stroke rehabilitation. In current clinical practice, visual feedback of movement performance is often limited to the use of mirrors or video. However, neither approach is optimal since cognitive and self-image issues can distract or distress patients and their movement can be obscured by clothing or limited viewpoints. Three-dimensional motion capture has the potential to provide accurate kinematic data required for objective assessment and feedback in the clinical environment. However, such data are currently presented in numerical or graphical format, which is often impractical in a clinical setting. Our hypothesis is that presenting this kinematic data using bespoke visualisation software, which is tailored for gait rehabilitation after stroke, will provide a means whereby feedback of movement performance can be communicated in a more meaningful way to patients. This will result in increased patient understanding of their rehabilitation and will enable progress to be tracked in a more accessible way. METHODS: The hypothesis will be assessed using an exploratory (phase II) randomised controlled trial. Stroke survivors eligible for this trial will be in the subacute stage of stroke and have impaired walking ability (Functional Ambulation Classification of 1 or more). Participants (n = 45) will be randomised into three groups to compare the use of the visualisation software during overground physical therapy gait training against an intensity-matched and attention-matched placebo group and a usual care control group. The primary outcome measure will be walking speed. Secondary measures will be Functional Ambulation Category, Timed Up and Go, Rivermead Visual Gait Assessment, Stroke Impact Scale-16 and spatiotemporal parameters associated with walking. Additional qualitative measures will be used to assess the participant's experience of the visual feedback provided in the study. DISCUSSION: Results from the trial will explore whether the early provision of visual feedback of biomechanical movement performance during gait rehabilitation demonstrates improved mobility outcomes after stroke and increased patient understanding of their rehabilitation.Trial registrationCurrent Controlled Trials ISRCTN79005974.     

Action de la prolactine chez l'Anguille

Résumé Les modifications histologiques de la thyroïde de l'Anguille traitée avec la prolactine ovine indiquent une forte activation qui paraît liée à une hypersécrétion d'hormone thyréotrope, les cellules adénohypophysaires élaborant cette stimuline étant très actives.L'emploi de l'iode radioactif ¹³¹I permet de préciser que la prolactine provoque une augmentation de la fixation thyroïdienne de l'isotope, et l'histoautoradiographie met en évidence un accroissement marqué de la synthèse des composés organiques iodés. On observe également une chute plus rapide de la radioactivité sérique, le rapport thyroïde/sérum étant beaucoup plus élevé chez les animaux traités que chez les témoins, par contre l'excrétion de l'iode dans le milieu externe est ralentie.Ces diverses données permettent donc d'établir que la prolactine ovine n'agit pas chez l'Anguille comme une substance antithyroïdienne et ne confirment pas l'hypothèse d'une action goitrogène formulée par Etkin et Gona chez divers Amphibiens. Au contraire, ces résultats sont similaires à ceux de Mazzi et ses collaborateurs sur un autre Amphibien, montrant que la prolactine stimule l'activité fonctionnelle de la thyroïde; cette action s'exerce par l'intermédiaire de l'hypophyse et paraît offrir une analogie avec celle d'un TRF, toutefois le mécanisme initial de ce processus reste à élucider.

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Action of prolactin in eelsIV. Thyroidal metabolism

Summary The histological changes described in the thyroid gland of ovinprolactin treated eels indicate a strong stimulation (Figs. 1 and 2) which seems correlated with a hypersecretion of thyrotrophic hormone as the adenohypophyseal cells elaborating this stimulin are highly activated.In prolactin injected eels, the utilization of radioiodine ¹³¹I demonstrates that the thyroidal iodine uptake increases (Fig. 7) and histoautoradiography shows a significant increase in the synthesis of iodinated organic compounds (Figs. 3 to 6). The thyroid/serum ratio has much higher values than in control animals, in correlation with a decrease in serum radioactivity (Fig. 8); the iodine excretion in water is reduced.These various data establish that ovin prolactin has no antithyroid effect in the eel, although the hypothesis of a goitrogenic action has been formulated for some amphibians by Etkin and Gona. On the other hand, these results are similar to those of Mazzi and his school, obtained in another amphibian, which show that prolactin stimulates the thyroidal functional activity. This action seems mediated by the pituitary gland and appears to be somewhat analogous with that of a thyrotropic releasing factor; however, the initial step of this process remains to be investigated.

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Nous remercions très vivement le NIH de Bethesda, Endocrinology Study Section, qui nous a généreusement offert la prolactine ovine utilisée dans ces expériences, Mr. F. Lachiver et Melle F. Boulu pour les mesures de la radioactivité sérique et de la fixation thyroïdienne totale qu'ils ont bien voulu effectuer, et Meile J. Olivereau, du CNRS, pour son assistance technique dans la réalisation de ce travail.     

Genome‐wide SNP analysis reveals an increase in adaptive genetic variation through selective breeding of coral

Marine heat waves are increasing in magnitude, duration, and frequency as a result of climate change and are the principal global driver of mortality in reef‐building corals. Resilience‐based genetic management may increase coral heat tolerance, but it is unclear how temperature responses are regulated at the genome level and thus how corals may adapt to warming naturally or through selective breeding. Here we combine phenotypic, pedigree, and genomic marker data from colonies sourced from a warm reef on the Great Barrier Reef reproductively crossed with conspecific colonies from a cooler reef to produce combinations of warm purebreds and warm‐cool hybrid larvae and juveniles. Interpopulation breeding created significantly greater genetic diversity across the coral genome compared to breeding between populations and maintained diversity in key regions associated with heat tolerance and fitness. High‐density genome‐wide scans of single nucleotide polymorphisms (SNPs) identified alleles significantly associated with larval families reared at 27.5°C (87–2,224 loci), including loci putatively associated with proteins involved in responses to heat stress (cell membrane formation, metabolism, and immune responses). Underlying genetics of these families explained 43% of PCoA multilocus variation in survival, growth, and bleaching responses at 27.5°C and 31°C at the juvenile stage. Genetic marker contribution to total variation in fitness traits (narrow‐sense heritability) was high for survival but not for growth and bleaching in juveniles, with heritability of these traits being higher at 31°C relative to 27.5°C. While based on only a limited number of crosses, the mechanistic understanding presented here demonstrates that allele frequencies are affected by one generation of selective breeding, key information for the assessments of genetic intervention feasibility and modelling of reef futures.     

Diversity of dermal denticle structure in sharks: Skin surface roughness and three‐dimensional morphology

Shark skin is covered with numerous placoid scales or dermal denticles. While previous research has used scanning electron microscopy and histology to demonstrate that denticles vary both around the body of a shark and among species, no previous study has quantified three‐dimensional (3D) denticle structure and surface roughness to provide a quantitative analysis of skin surface texture. We quantified differences in denticle shape and size on the skin of three individual smooth dogfish sharks (Mustelus canis) using micro‐CT scanning, gel‐based surface profilometry, and histology. On each smooth dogfish, we imaged between 8 and 20 distinct areas on the body and fins, and obtained further comparative skin surface data from leopard, Atlantic sharpnose, shortfin mako, spiny dogfish, gulper, angel, and white sharks. We generated 3D images of individual denticles and measured denticle volume, surface area, and crown angle from the micro‐CT scans. Surface profilometry was used to quantify metrology variables such as roughness, skew, kurtosis, and the height and spacing of surface features. These measurements confirmed that denticles on different body areas of smooth dogfish varied widely in size, shape, and spacing. Denticles near the snout are smooth, paver‐like, and large relative to denticles on the body. Body denticles on smooth dogfish generally have between one and three distinct ridges, a diamond‐like surface shape, and a dorsoventral gradient in spacing and roughness. Ridges were spaced on average 56 µm apart, and had a mean height of 6.5 µm, comparable to denticles from shortfin mako sharks, and with narrower spacing and lower heights than other species measured. We observed considerable variation in denticle structure among regions on the pectoral, dorsal, and caudal fins, including a leading‐to‐trailing edge gradient in roughness for each region. Surface roughness in smooth dogfish varied around the body from 3 to 42 microns.     

Social responses to variation in food supply and nest suitability in ants (Tapinoma erraticum)

The social organization of Tapinoma erraticum colonies has been studied in two environmental contexts: those of mild starvation and of disturbance inducing a complete change of nest site. Trophallactic activity was compared with brood transport behaviour in tests performed repeatedly on the same group of insects. Workers were individually marked enabling interactions to be analysed within the group. An age-dependent difference in behaviour exists during feeding. However, when the colony changed its location, certain workers were found to be transport specialists, whereas others remained inactive: the transport behaviour of T. erraticum workers does not appear to be agedependent, unlike feeding behaviour. A principal components analysis of the results indicated no link between these two types of activities at the individual level. This study indicates the existence of types of social organization which are specific to each of the activities performed.     

Characteristic alatoid ‘cineole cassette’ monoterpene synthase present in Nicotiana noctiflora

Nicotiana species of the section Alatae emit a characteristic floral scent comprising the? cineole cassette’ monoterpenes 1,8-cineole, limonene, myrcene, β-pinene, α-pinene, sabinene and α-terpineol. All previously isolated ‘cineole cassette’-monoterpene synthase genes are multi product enzymes that synthesize the seven compounds of the ‘cineole cassette’. Interestingly, so far this ‘alatoid’ trait was only shared with the eponymous species Nicotiana suaveolens of the sister section Suaveolentes. To determine the origin of the ‘cineole cassette’ monoterpene phenotype other potential parent species of section Noctiflorae or Petunoides as well as of the distantly related section Trigonophyllae were analysed. A monoterpene synthase producing the set of ‘cineole cassette’ compounds was isolated from N. noctiflorae. N. obtusifolia emitted solely 1,8-cineole and no monoterpenes were found in floral scents of N. petunoides and N. palmeri. Interestingly, the phylogenetic analysis clustered the new gene of N. noctiflora closely to the terpineol synthase genes of e.g. N. alata rather than to cineole synthase genes of e.g. N. forgetiana.     

Activité de la pars intermedia de l'hypophyse autotransplantée chez l'Anguille

Résumé Chez l'Anguille dont l'hypophyse est autotransplantée dans la musculature dorsale depuis 2 mois, la pigmentation est assez variable, mais généralement plus sombre que celle des animaux hypophysectomisés. De plus, une tache foncée apparaît au voisinage du greffon, indiquant une sécrétion d'intermédine ou MSH (melanocyte-stimulating hormone). Il existe une corrélation entre l'intensité de la pigmentation, le diamètre de cette tache noire et le degré de conservation de la pars intermedia dans les 13 cas où celle-ci est identifiée dans le greffon; le tissu intermédiaire est absent chez les 3 Anguilles aussi pâles que celles hypophysectomisées.La pars intermedia contient normalement 2 catégories cellulaires; seule celle colorable par l'hématoxyline au plomb (H-Pb) est encore présente dans les transplants: elle apparaît donc responsable de la sécrétion de l'intermédine; l'autre catégorie PAS (acide periodique-fuchsine de Schiff) positive, moins abondante, régresse fortement et peut même disparaître. Il s'agit donc bien de deux types cellulaires distincts, avec une évolution propre. Cependant, aucun caractère histologique ne permet de penser que les cellules hématoxylinophiles de la pars intermedia sont hyperactives, et ce fait, joint à l'absence d'une mélano-dispersion permanente n'autorise pas à conclure à la présence d'un facteur hypothalamique inhibant la décharge de MSH ou MSH-IF chez cette espèce, similaire à celui décrit chez les Amphibiens; l'hypothèse inverse de l'existence d'un MSH-RF, ou facteur de décharge de MSH, apparaît plus probable, bien que la pars intermedia jouisse d'une autonomie importante chez l'Anguille. Ces observations sont discutées à la lumière des données publiées chez d'autres Vertébrés.L'hormone de type prolactinique sécrétée par les cellules érythrosinophiles de l'hypophyse, présentes dans les 15 greffons viables, ne semble pas jouer de rôle primordial dans le contrôle de la pigmentation, elle apparaît même incapable de reproduire l'effet mélano-dispersant de la prolactine ovine. Les cellules corticotropes, identifiées dans les 15 greffons, ne paraissent pas intervenir dans le maintien de la pigmentation, mais il reste à préciser leur activité fonctionnelle.

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Activity of the pars intermedia of the autotransplanted pituitary gland in the European eel

Summary The pituitary gland was autotransplanted in the dorsal muscle of 16 eels; 2 months later, the pigmentation is quite variable, but generally darker than that of hypophysectomized animals. Also, a dark spot appears close to the graft, indicating intermedin (MSH) secretion. There is a correlation between the intensity of the pigmentation, the diameter of the black spot, and the degree of maintenance of the pars intermedia in the 13 cases where it was identified in the transplant. The intermediate lobe tissue is absent in the 3 eels which are as pale as the hypophysectomized ones.The pars intermedia normally contains 2 cell types: only the cell stainable with the leadhaematoxylin technique (H-Pb) is still present in the grafts: then, it appears responsible for the elaboration of intermedin. The other cell type, PAS positive, less abundant, is strongly regressed and can even disappear. It seems obvious that there are two distinct cell types with their own development. However, no histological criteria suggest that the H-Pb positive cells are hyperactive. As there is no permanent melano-dispersion in the grafted animals, it does not seem evident that the hypothalamus of the eel secretes a MSH-inhibiting factor (MSH-IF) similar to that described in Amphibians. Conversely, the hypothesis of a MSH-releasing factor (MSH-RF) would appear more probable despite a large degree of autonomy of the pars intermedia. These observations are compared with data published on various Vertebrates.The prolactin-like hormone secreted by the erythrosinophilic cells of the pituitary gland, identified in the 15 healthy grafts, does not seem to play an important role in the control of the pigmentation. It appears even unable to mimic the melanophoro-dispersing effect of the ovine prolactin. The corticotrophic cells present in the 15 transplants do not seem to act on the maintenance of the pigmentation, but their functional activity remains to be evaluated.

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Nous remercions bien vivement le Dr. Anastasija Dimovska pour l'aide amicale qu'elle nous a apportée au cours de cette expérience lors de son séjour en France rendu possible grâce à une bourse du Gouvernement Yougoslave. Nous remercions Mme Cuvier pour sa participation aux hypophysectomies et aux greffes et Melle J. Olivereau du CNRS pour sa collaboration histologique.     

Modifications des cellules corticotropes de l'hypophyse chez l'anguille radiothyroïdectomisée

Résumé Chez les Anguilles dont la destruction totale ou sub-totale de la glande thyroïde a été réalisée avec des injections répétées de fortes doses d'iode radioactif ¹³¹I, l'interrénal présente un aspect histologique indiquant un hypofonctionnement traduit par une atrophie cellulaire et nucléaire. De même, après 2 à 8 mois d'expérience, les cellules corticotropes de l'hypophyse sont plus petites, moins granulées à l'apex qui devient finement vacuolisé, le diamètre nucléaire est significativement réduit. La réponse de l'interrénal à la thyroïdectomie est donc contrôlée en partie par l'hypophyse. Comme l'apport de thyroxine stimule l'axe hypophyso-corticosurrénalien de l'Anguille, et la réduction ou la disparition des hormones thyroïdiennes le déprime, il semble exister chez ce Téléostéen une synergie entre les activités de la thyroïde et de l'interrénal ayant l'hypophyse comme intermédiaire.

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Modifications of the Corticotrophic Cells of the hypophysis of the radiothyroidectomized eel

Summary Eels were completely or sub-totally radiothyroidectomized with repeated injections of high doses of radioiodine ¹³¹I. After 2 to 8 months, the histological picture of the interrenal suggests a hypoactivity, indicated by a nuclear and nucleolar atrophy. Simultaneously, in the pituitary gland, the corticotrophic cells are smaller, less granulated with a finely vacuolated apical cytoplasm. The diameter of their nuclei is significantly reduced. It then appears that the adrenal response to thyroidectomy is, at least partly, mediated by the pituitary gland. As thyroxine treatment induces a stimulation of the hypophyso-adrenocortical system in the eel, and a decrease or disappearance of thyroidal hormones exerts a depressing effect, it seems that there is a synergy between the activity of the thyroid gland and the interrenal in this species, the hypophysis playing a role of mediator in these responses.

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Ce travail a été réalisé avec la collaboration technique de Mademoiselle Jacqueline Olivereau, du CNRS, que nous remercions bien vivement.     

Pattern and pace of morphological change due to variable human impact: the case of Japanese macaques

Primates - Human impact influences morphological variation in animals, as documented in many captive and domestic animal populations. However, there are different levels of human impact, and their...