LIMB PATTERNING
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Rat hypodactyly (hd) is an autosomal recessive mutation manifesting in homozygotes as reduction or loss of digits II and III. We mapped the hd allele to a short segment of chromosome 10, containing 16 genes. None of these genes has been shown to influence limb development yet. In situ hybridization showed no changes in several important patterning genes (Shh, Fgf8, Bmp2, 4, 7). However, we found that expression of cartilage condensation marker Sox9, and Bmp receptor Bmpr1b (acting as an upstream activator of Sox9 expression) is absent from the subepithelial mesenchyme of the digit condensations II and III. The failure of the chondrogenic condensations to extend towards the subepithelial mesenchyme may reduce the size of digit primordia and underlie the subsequent loss of phalanges and reduction of metacarpals/metatarsals in hd rats.
- MeSH
- embryo savčí anatomie a histologie metabolismus MeSH
- fenotyp MeSH
- financování organizované MeSH
- homeodoménové proteiny genetika metabolismus MeSH
- končetinové pupeny abnormality metabolismus MeSH
- končetiny MeSH
- krysa rodu rattus MeSH
- mutace MeSH
- potkani Wistar MeSH
- receptory morfogenetických kostních proteinů typu I genetika metabolismus MeSH
- rozvržení tělního plánu genetika MeSH
- transkripční faktor SOX9 genetika metabolismus MeSH
- vývojová regulace genové exprese MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
Two theories address the origin of repeating patterns, such as hair follicles, limb digits, and intestinal villi, during development. The Turing reaction-diffusion system posits that interacting diffusible signals produced by static cells first define a prepattern that then induces cell rearrangements to produce an anatomical structure. The second theory, that of mesenchymal self-organisation, proposes that mobile cells can form periodic patterns of cell aggregates directly, without reference to any prepattern. Early hair follicle development is characterised by the rapid appearance of periodic arrangements of altered gene expression in the epidermis and prominent clustering of the adjacent dermal mesenchymal cells. We assess the contributions and interplay between reaction-diffusion and mesenchymal self-organisation processes in hair follicle patterning, identifying a network of fibroblast growth factor (FGF), wingless-related integration site (WNT), and bone morphogenetic protein (BMP) signalling interactions capable of spontaneously producing a periodic pattern. Using time-lapse imaging, we find that mesenchymal cell condensation at hair follicles is locally directed by an epidermal prepattern. However, imposing this prepattern's condition of high FGF and low BMP activity across the entire skin reveals a latent dermal capacity to undergo spatially patterned self-organisation in the absence of epithelial direction. This mesenchymal self-organisation relies on restricted transforming growth factor (TGF) β signalling, which serves to drive chemotactic mesenchymal patterning when reaction-diffusion patterning is suppressed, but, in normal conditions, facilitates cell movement to locally prepatterned sources of FGF. This work illustrates a hierarchy of periodic patterning modes operating in organogenesis.
- MeSH
- buněčná diferenciace MeSH
- inbrední kmeny myší MeSH
- kůže cytologie embryologie metabolismus MeSH
- myši MeSH
- rozvržení tělního plánu MeSH
- signální transdukce MeSH
- stanovení celkové genové exprese MeSH
- transformující růstový faktor beta metabolismus fyziologie MeSH
- vlasový folikul embryologie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Článek shrnuje výsledky disertační práce, která představuje nový přístup v navrhování kompenzačních pomůcek z hlediska mechanického řešení a netradičního designu. Práce byla řešena pro konkrétního pacienta s vrozeným postižením horních končetin zvaným fokomélie. Řešení vzniklo na základě osobních konzultací a schůzek na specializovaném pracovišti, kde byla pro našeho pacienta vyrobena kompenzační pomůcka na míru, avšak způsobem a z dílů určených pro jiný druh postižení. Jak se ukázalo, používání této pomůcky je spojeno s celou řadou problémů, a proto se ve výsledku toto řešení ukázalo jako nevyhovující. Díky ní však bylo možné problémy blíže specifikovat, odhalit důležité zákonitosti a poukázat na nutnost vývoje zcela nové a unikátní pomůcky speciálně pro pacienty postižené fokomélií. Práce vychází z těchto nabytých zjištění a z rešeršních poznatků z oblasti ortotiky, protetiky, kompenzačních pomůcek a protetického vybavení. Následně byl proveden kompletní redesign, jehož cílem bylo odstranit všechny zjištěné problémy. Výsledkem předkládané práce je koncept jedinečné pomůcky pro osoby se specifickým vrozeným postižením horních končetin, která nese pracovní označení 4TE.
This article summarizes the results of the project which deals with a new approach to designing ortho-prosthetic devices in terms of mechanical solution and innovative design. The work was addressed to a specific patient with congenital malformation of upper limbs called phocomelia. A custom-made compensatory aid was designed on the basis of personal consultations and meetings at specialized workplace; however the aid was built in a way and from parts for other kind of disability. As it turned out, the use of this device is associated with many complications, and therefore as a result, this solution proved as unsatisfactory. Nevertheless, thanks to this compensation aid, it was possible to specify the problems, to reveal important patterns and highlight the needs for development of entirely new and unique aid designed for patients with phocomelia disability. The work is based on these findings and knowledge acquired from bibliographic search in the field of orthotics, prosthetics, assistive devices and prosthetic equipment. A complete redesign was done with the aim to eliminate all detected problems. The presented result is a unique tool for people with specific congenital disability of upper limbs, with working label 4TE.
- Klíčová slova
- ortoprotetika, handicap, kompenzační pomůcka, design, vrozené postižení horní končetiny, fokomélie, 4TE,
- MeSH
- dítě MeSH
- ektromelie * MeSH
- lidé MeSH
- paže MeSH
- postižené děti MeSH
- postižení MeSH
- protézy - design * metody přístrojové vybavení MeSH
- umělé končetiny * normy MeSH
- vrozené deformity horní končetiny MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- kazuistiky MeSH
Lx mutation in SHR.Lx rat manifests in homozygotes as hindlimb preaxial polydactyly. It was previously mapped to a chromosome 8 segment containing the Plzf gene. Plzf (promyelocytic leukemia zinc finger protein) influences limb development as a direct repressor of posterior HoxD genes. However, the Plzf coding sequence is intact in the Lx mutants. Using linkage mapping in F2 hybrids, we downsized the segment containing Lx to 155 kb and sequenced conserved noncoding elements (CNEs) inside. A 2,964-bp deletion in Plzf intron 2, never detected in control animals, is the only candidate for Lx. The deletion removes the most deeply conserved CNE in the 155-kb segment, suggesting a regulatory influence on Plzf expression. Correspondingly, using in situ hybridization and quantitative real-time polymerase chain reaction, we found a decrease of Plzf expression in Lx/Lx limb buds with concomitant anterior expansion of expression domains of its targets, Hoxd10-13 genes, in the absence of ectopic Sonic hedgehog expression. Upstream regulation of Plzf in limb buds is currently unknown. We present here the first candidate Plzf cis-regulatory sequence. (c) 2009 Wiley-Liss, Inc.
- MeSH
- delece genu MeSH
- DNA vazebné proteiny genetika metabolismus MeSH
- down regulace genetika MeSH
- embryo savčí embryologie metabolismus MeSH
- financování organizované MeSH
- introny genetika MeSH
- končetinové pupeny abnormality metabolismus MeSH
- konzervovaná sekvence MeSH
- krysa rodu rattus MeSH
- messenger RNA genetika MeSH
- nekódující RNA genetika MeSH
- polydaktylie genetika metabolismus MeSH
- rozvržení tělního plánu MeSH
- sekvence nukleotidů MeSH
- vývojová regulace genové exprese MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
Vrozené vady končetin patří mezi nejčastější vrozené vady u člověka. Významná část těchto vad má genetický původ. Rostoucí znalost konkrétních mutací podmiňujících malformace končetin u člověka umožňuje větší dostupnost diagnostického vyšetření DNA pro potvrzení klinické diagnózy a pro genetické poradenství. Přibývající znalosti vývojových procesů získané studiem vad končetin u člověka i na experimentálních modelech mohou v budoucnosti nabídnout i lepší terapeutické možnosti. Tento článek se soustřeďuje na roli Hox genů ve vývoji končetiny. Člověk má stejně jako ostatní savci 39 HOX genů, rozdělených do čtyř komplexů. Tyto geny hrají zásadní roli při organizaci tělního plánu a vývoji mnoha orgánových systémů. Z experimentálně získaných údajů víme, že při vývoji končetiny ovlivňují její proximodistální a palcomalíkovou osu. U člověka byly v souvislosti s postižením končetin popsány mutace v genech HOXA11, HOXA13, HOXD10 a HOXD13. Nejčastější z těchto onemocnění jsou syndrom hand-foot-genital podmíněný mutací genu HOXA13 a synpolydaktylie podmíněná mutací genu HOXD13. Závažnost fenotypových projevů těchto onemocnění je variabilní v závislosti na konkrétním typu mutace daného genu, kdy se mohou uplatnit bodové mutace, polyalaninové expanze či delece.
In human, congenital malformations of the limbs are ranked among the most prevalent of all congenital birth defects. Substantial portion of these defects has genetic origin. Increasing knowledge about the particular mutations responsible for limb malformations in human results in the increasing availability of DNA diagnostic procedures for confirmation of clinical diagnosis and family counselling. Increasing understanding of the underlying developmental processes revealed by studying limb defects both in human and animal models may offer better therapeutic options in the future. This review concentrates on the role of Hox genes in limb development. Man, as well as other mammals, has 39 HOX genes, divided into 4 complexes (clusters). HOX genes play a major role in body plan layout and development of many organ systems. Experimental data show that during the limb development, HOX genes influence patterning along the proximodistal and anteroposterior (thumb-little finger) axis of the limb bud. In human, limb malformation was described in patients with mutations in HOXA11, HOXA13, HOXD10, and HOXD13 genes. Most frequent among these malformations are hand-foot-genital syndrome caused by HOXA13 gene mutation, and synpolydactyly caused by HOXD13 mutation. Severity of the phenotype manifestation of these diseases is variable, and depends on the particular mutation type, where point mutations, polyalanine expansions and deletions can take part.
- MeSH
- homeoboxové geny MeSH
- lidé MeSH
- mutace MeSH
- vrozené deformity končetin embryologie genetika MeSH
- vývojová regulace genové exprese MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- přehledy MeSH
BACKGROUND: Limb girdle muscular dystrophy type R1/2A (LGMDR1/LGMD2A) is a progressive myopathy caused by deficiency of calpain 3, a calcium-dependent cysteine protease of skeletal muscle, and it represents the most frequent type of LGMD worldwide. In the last few years, muscle magnetic resonance imaging (MRI) has been proposed as a tool for identifying patterns of muscular involvement in genetic disorders and as a biomarker of disease progression in muscle diseases. In this study, 57 molecularly confirmed LGMDR1 patients from a European cohort (age range 7-78 years) underwent muscle MRI and a global evaluation of functional status (Gardner-Medwin and Walton score and ability to raise the arms). RESULTS: We confirmed a specific pattern of fatty substitution involving predominantly the hip adductors and hamstrings in lower limbs. Spine extensors were more severely affected than spine rotators, in agreement with higher incidence of lordosis than scoliosis in LGMDR1. Hierarchical clustering of lower limb MRI scores showed that involvement of anterior thigh muscles discriminates between classes of disease progression. Severity of muscle fatty substitution was significantly correlated with CAPN3 mutations: in particular, patients with no or one "null" alleles showed a milder involvement, compared to patients with two null alleles (i.e., predicting absence of calpain-3 protein). Expectedly, fat infiltration scores strongly correlated with functional measures. The "pseudocollagen" sign (central areas of sparing in some muscle) was associated with longer and more severe disease course. CONCLUSIONS: We conclude that skeletal muscle MRI represents a useful tool in the diagnostic workup and clinical management of LGMDR1.
- MeSH
- dítě MeSH
- dospělí MeSH
- kosterní svaly diagnostické zobrazování patologie patofyziologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- magnetická rezonanční tomografie * MeSH
- mladiství MeSH
- mladý dospělý MeSH
- pletencové svalové dystrofie diagnostické zobrazování genetika patologie patofyziologie MeSH
- senioři MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Evropa MeSH
Alien limb phenomenon is a rare syndrome associated with a feeling of non-belonging and disowning toward one's limb. In contrast, anarchic limb phenomenon leads to involuntary but goal-directed movements. Alien/anarchic limb phenomena are frequent in corticobasal syndrome (CBS), an atypical parkinsonian syndrome characterized by rigidity, akinesia, dystonia, cortical sensory deficit, and apraxia. The structure-function relationship of alien/anarchic limb was investigated in multi-centric structural magnetic resonance imaging (MRI) data. Whole-group and single-subject comparisons were made in 25 CBS and eight CBS-alien/anarchic limb patients versus controls. Support vector machine was used to see if CBS with and without alien/anarchic limb could be distinguished by structural MRI patterns. Whole-group comparison of CBS versus controls revealed asymmetric frontotemporal atrophy. CBS with alien/anarchic limb syndrome versus controls showed frontoparietal atrophy including the supplementary motor area contralateral to the side of the affected limb. Exploratory analysis identified frontotemporal regions encompassing the pre-/and postcentral gyrus as compromised in CBS with alien limb syndrome. Classification of CBS patients yielded accuracies of 79%. CBS-alien/anarchic limb syndrome was differentiated from CBS patients with an accuracy of 81%. Predictive differences were found in the cingulate gyrus spreading to frontomedian cortex, postcentral gyrus, and temporoparietoocipital regions. We present the first MRI-based group analysis on CBS-alien/anarchic limb. Results pave the way for individual clinical syndrome prediction and allow understanding the underlying neurocognitive architecture.
- MeSH
- lidé středního věku MeSH
- lidé MeSH
- magnetická rezonanční tomografie MeSH
- mozek diagnostické zobrazování MeSH
- parkinsonské poruchy diagnostické zobrazování MeSH
- počítačové zpracování obrazu MeSH
- senioři MeSH
- syndrom cizí končetiny diagnostické zobrazování MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
This study investigated the whole-body coordination patterning in successful and faulty spikes using self-organising map-based cluster analysis. Ten young, elite volleyball players (aged 15.5 ± 0.7 years) performed 60 volleyball spikes in a real-game environment. Adopting the cluster analysis, based on a self-organising map, whole-body coordination patterning was explored between successful and faulty spikes of individual players. The self-organising maps (SOMs) portrayed whole body, lower and upper limb coordination dissimilarities during the jump phase and the ball impact phases between the successful and faulty spikes. The cluster analysis illustrated that the whole body, upper limb and lower limb coordination patterning of each individual's successful spikes were similar to their faulty spikes. Range of motion patterning also demonstrated no differences in kinematics between spike outcomes. Further, the upper limb angular velocity patterning of the players' successful/faulty spikes were similar. The SPM analysis portrayed significant differences between the normalized upper limb angular velocities from 35% to 45% and from 76% to 100% of the spike movement. Although the lower limb angular velocities are vital for achieving higher jumps in volleyball spikes, the results of this study portrayed that the upper limb angular velocities distinguish the differences between successful and faulty spikes among the attackers. This confirms the fact that volleyball coaches should shift their focus toward the upper limb velocity and coordination training for higher success rates in spiking for volleyball attackers.
- MeSH
- biomechanika MeSH
- dolní končetina MeSH
- lidé MeSH
- mladiství MeSH
- pohyb MeSH
- rozsah kloubních pohybů MeSH
- shluková analýza MeSH
- sportovní výkon * MeSH
- volejbal * MeSH
- Check Tag
- lidé MeSH
- mladiství MeSH
- Publikační typ
- časopisecké články MeSH