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Sample records for hind limb scaling

  1. Scaling and functional morphology in strigiform hind limbs

    PubMed Central

    Madan, Meena A.; Rayfield, Emily J.; Bright, Jen A.

    2017-01-01

    Strigiformes are an order of raptorial birds consisting exclusively of owls: the Tytonidae (barn owls) and the Strigidae (true owls), united by a suite of adaptations aiding a keen predatory lifestyle, including robust hind limb elements modified for grip strength. To assess variation in hind limb morphology, we analysed how the dimensions of the major hind limb elements in subfossil and modern species scaled with body mass. Comparing hind limb element length, midshaft width, and robusticity index (RI: ratio of midshaft width to maximum length) to body mass revealed that femoral and tibiotarsal width scale with isometry, whilst length scales with negative allometry, and close to elastic similarity in the tibiotarsus. In contrast, tarsometatarsus width shows strong positive allometry with body mass, whilst length shows strong negative allometry. Furthermore, the tarsometatarsi RI scales allometrically to mass0.028, whilst a weak relationship exists in femora (mass0.004) and tibiotarsi (mass0.004). Our results suggest that tarsometatarsi play a more substantial functional role than tibiotarsi and femora. Given the scaling relationship between tarsometatarsal width and robusticity to body mass, it may be possible to infer the body mass of prehistoric owls by analysing tarsometatarsi, an element that is frequently preserved in the fossil record of owls. PMID:28327549

  2. Ontogenetic Scaling of Fore- and Hind Limb Posture in Wild Chacma Baboons (Papio hamadryas ursinus)

    PubMed Central

    Patel, Biren A.; Horner, Angela M.; Thompson, Nathan E.; Barrett, Louise; Henzi, S. Peter

    2013-01-01

    Large-scale interspecific studies of mammals ranging between 0.04–280 kg have shown that larger animals walk with more extended limb joints. Within a taxon or clade, however, the relationship between body size and joint posture is less straightforward. Factors that may affect the lack of congruence between broad and narrow phylogenetic analyses of limb kinematics include limited sampling of (1) ranges of body size, and/or (2) numbers of individuals. Unfortunately, both issues are inherent in laboratory-based or zoo locomotion research. In this study, we examined the relationship between body mass and elbow and knee joint angles (our proxies of fore- and hind limb posture, respectively) in a cross-sectional ontogenetic sample of wild chacma baboons (Papio hamadryas ursinus) habituated in the De Hoop Nature Reserve, South Africa. Videos were obtained from 33 individuals of known age (12 to ≥108 months) and body mass (2–29.5 kg) during walking trials. Results show that older, heavier baboons walk with significantly more extended knee joints but not elbow joints. This pattern is consistent when examining only males, but not within the female sample. Heavier, older baboons also display significantly less variation in their hind limb posture compared to lighter, young animals. Thus, within this ontogenetic sample of a single primate species spanning an order of magnitude in body mass, hind limb posture exhibited a postural scaling phenomenon while the forelimbs did not. These findings may further help explain 1) why younger mammals (including baboons) tend to have relatively stronger bones than adults, and 2) why humeri appear relatively weaker than femora (in at least baboons). Finally, this study demonstrates how field-acquired kinematics can help answer fundamental biomechanical questions usually addressed only in animal gait laboratories. PMID:23923046

  3. Ontogenetic scaling of fore- and hind limb posture in wild chacma baboons (Papio hamadryas ursinus).

    PubMed

    Patel, Biren A; Horner, Angela M; Thompson, Nathan E; Barrett, Louise; Henzi, S Peter

    2013-01-01

    Large-scale interspecific studies of mammals ranging between 0.04-280 kg have shown that larger animals walk with more extended limb joints. Within a taxon or clade, however, the relationship between body size and joint posture is less straightforward. Factors that may affect the lack of congruence between broad and narrow phylogenetic analyses of limb kinematics include limited sampling of (1) ranges of body size, and/or (2) numbers of individuals. Unfortunately, both issues are inherent in laboratory-based or zoo locomotion research. In this study, we examined the relationship between body mass and elbow and knee joint angles (our proxies of fore- and hind limb posture, respectively) in a cross-sectional ontogenetic sample of wild chacma baboons (Papio hamadryas ursinus) habituated in the De Hoop Nature Reserve, South Africa. Videos were obtained from 33 individuals of known age (12 to ≥ 108 months) and body mass (2-29.5 kg) during walking trials. Results show that older, heavier baboons walk with significantly more extended knee joints but not elbow joints. This pattern is consistent when examining only males, but not within the female sample. Heavier, older baboons also display significantly less variation in their hind limb posture compared to lighter, young animals. Thus, within this ontogenetic sample of a single primate species spanning an order of magnitude in body mass, hind limb posture exhibited a postural scaling phenomenon while the forelimbs did not. These findings may further help explain 1) why younger mammals (including baboons) tend to have relatively stronger bones than adults, and 2) why humeri appear relatively weaker than femora (in at least baboons). Finally, this study demonstrates how field-acquired kinematics can help answer fundamental biomechanical questions usually addressed only in animal gait laboratories.

  4. Scaling factor relating conduction velocity and diameter for myelinated afferent nerve fibres in the cat hind limb.

    PubMed Central

    Boyd, I A; Kalu, K U

    1979-01-01

    1. Compound action potentials were recorded from certain muscle and cutaneous nerves in normal and chronically de-efferentated hind limbs of cats during stimulation of the appropriate dorsal spinal roots, 2. The peaks for groups I, II and III in the compound action potential were correlated with the corresponding peaks in the fibre-diameter histograms of the same de-efferentated nerve after processing it for light microscopy. 3. The scaling factor (ratio of conduction velocity in m/sec to total diameter in micrometer) was not constant for all sizes of fibre nor did it increase progressively with fibre size. Evidence is presented that a logarithmic relation between conduction velocity and fibre diameter is not appropriate. 4. In muscle nerves the scaling factor for fibres fixed by glutaraldehyde perfusion and embedded in Epon was 5.7 for group I afferent fibres and 4.6 for myelinated fibres in both group II and group III. 5. In cutaneous nerves the scaling factor was 5.6 for large fibres (group I or Abeta) and 4.6 for small fibres (group III or Adelta). 6. The scaling factor for group I fibres is the same as was found previously for alpha-efferent fibres, and that for groups II and III is the same as for gamma-efferent fibres (Boyd & Davey, 1968). 7. The possibility that there is a clear discontinuity in scaling factor between fibres in groups I and alpha, and those in other functional groups, is discussed. 8. It is concluded that there must be some structural feature of alpha and group I fibres which differs from that of smaller myelinated fibres. It is likely that a difference in the relative thickness of the myelin sheath is involved and possibly also in the conductances responsible for generating the action potential. Images Plate 1 PMID:458657

  5. Pelvic and hind limb musculature of Staurikosaurus pricei (Dinosauria: Saurischia).

    PubMed

    Grillo, Orlando N; Azevedo, Sergio A K

    2011-03-01

    The study of pelvic and hind limb bones and muscles in basal dinosaurs is important for understanding the early evolution of bipedal locomotion in the group. The use of data from both extant and extinct taxa placed into a phylogenetic context allowed to make well-supported inferences concerning most of the hind limb musculature of the basal saurischian Staurikosaurus pricei Colbert, 1970 (Santa Maria Formation, Late Triassic of Rio Grande do Sul, Brazil). Two large concavities in the lateral surface of the ilium represent the origin of the muscles iliotrochantericus caudalis plus iliofemoralis externus (in the anterior concavity) and iliofibularis (in the posterior concavity). Muscle ambiens has only one head and originates from the pubic tubercle. The origin of puboischiofemoralis internus 1 possibly corresponds to a fossa in the ventral margin of the pré-acetabular iliac process. This could represent an intermediate stage prior to the origin of a true pré-acetabular fossa. Muscles caudofemorales longus et brevis were likely well developed, and Staurikosaurus is unique in bearing a posteriorly projected surface for the origin of caudofemoralis brevis.

  6. Hind-limb vascular-capacitance responses in anaesthetized dogs.

    PubMed Central

    Hainsworth, R; Karim, F; McGregor, K H; Wood, L M

    1983-01-01

    In anaesthetized dogs a hind limb was vascularly isolated, perfused through the femoral artery at either constant flow or constant pressure and drained from the femoral vein at constant pressure. Inflow and outflow were recorded. Vascular-resistance changes were calculated from changes in pressure or flow and volume changes from the differences between inflow and outflow. During constant-flow perfusion, both changes in carotid sinus pressure and direct stimulation of efferent sympathetic nerves resulted in large resistance responses. However, changes in carotid sinus pressure did not result in changes in limb blood volume and only small decreases were obtained in response to direct stimulation. During constant-pressure perfusion, both reflex and direct stimulation resulted not only in significant changes in resistance but also in significant volume changes which were much larger than those obtained during constant-flow perfusion. Similar responses were obtained when the flow rate was changed by altering the pump speed. These results indicate that changes in pressure to carotid baroreceptors do not result in active capacitance responses in the limb circulation and that only very small responses are obtained even to electrical stimulation of sympathetic nerves. The larger responses occurring during constant-pressure perfusion are thought to be secondary to changes in blood flow. PMID:6875939

  7. Bone morphology of the hind limbs in two caviomorph rodents.

    PubMed

    de Araújo, F A P; Sesoko, N F; Rahal, S C; Teixeira, C R; Müller, T R; Machado, M R F

    2013-04-01

    In order to evaluate the hind limbs of caviomorph rodents a descriptive analysis of the Cuniculus paca (Linnaeus, 1766) and Hydrochoerus hydrochaeris (Linnaeus, 1766) was performed using anatomical specimens, radiography, computed tomography (CT) and full-coloured prototype models to generate bone anatomy data. The appendicular skeleton of the two largest rodents of Neotropical America was compared with the previously reported anatomical features of Rattus norvegicus (Berkenhout, 1769) and domestic Cavia porcellus (Linnaeus, 1758). The structures were analyzed macroscopically and particular findings of each species reported. Features including the presence of articular fibular projection and lunulae were observed in the stifle joint of all rodents. Imaging aided in anatomical description and, specifically in the identification of bone structures in Cuniculus paca and Hydrochoerus hydrochaeris. The imaging findings were correlated with the anatomical structures observed. The data may be used in future studies comparing these animals to other rodents and mammalian species.

  8. New Australovenator hind limb elements pertaining to the holotype reveal the most complete Neovenatorid leg.

    PubMed

    White, Matt A; Benson, Roger B J; Tischler, Travis R; Hocknull, Scott A; Cook, Alex G; Barnes, David G; Poropat, Stephen F; Wooldridge, Sarah J; Sloan, Trish; Sinapius, George H K; Elliott, David A

    2013-01-01

    We report new skeletal elements pertaining to the same individual which represents the holotype of Australovenator wintonensis, from the 'Matilda Site' in the Winton Formation (Upper Cretaceous) of western Queensland. The discovery of these new elements means that the hind limb of Australovenator is now the most completely understood hind limb among Neovenatoridae. The new hind limb elements include: the left fibula; left metatarsal IV; left pedal phalanges I-2, II-1, III-4, IV-2, IV-3; and right pedal phalanges, II-2 and III-1. The detailed descriptions are supported with three dimensional figures. These coupled with the completeness of the hind limb will increase the utility of Australovenator in comparisons with less complete neovenatorid genera. These specimens and the previously described hind limb elements of Australovenator are compared with other theropods classified as neovenatorids (including Neovenator, Chilantaisaurus, Fukuiraptor, Orkoraptor and Megaraptor). Hind limb length proportion comparisons indicate that the smaller neovenatorids Australovenator and Fukuiraptor possess more elongate and gracile hind limb elements than the larger Neovenator and Chilantaisaurus. Greater stride lengths to body size exist in both Fukuiraptor and Australovenator with the femur discovered to be proportionally shorter the rest of the hind limb length. Additionally Australovenator is identified as possessing the most elongate metatarsus. The metatarsus morphology varies with body size. The larger neoventorids possess a metatarsus with greater width but shorter length compared to smaller forms.

  9. New Australovenator Hind Limb Elements Pertaining to the Holotype Reveal the Most Complete Neovenatorid Leg

    PubMed Central

    White, Matt A.; Benson, Roger B. J.; Tischler, Travis R.; Hocknull, Scott A.; Cook, Alex G.; Barnes, David G.; Poropat, Stephen F.; Wooldridge, Sarah J.; Sloan, Trish; Sinapius, George H. K.; Elliott, David A.

    2013-01-01

    We report new skeletal elements pertaining to the same individual which represents the holotype of Australovenator wintonensis, from the ‘Matilda Site’ in the Winton Formation (Upper Cretaceous) of western Queensland. The discovery of these new elements means that the hind limb of Australovenator is now the most completely understood hind limb among Neovenatoridae. The new hind limb elements include: the left fibula; left metatarsal IV; left pedal phalanges I-2, II-1, III-4, IV-2, IV-3; and right pedal phalanges, II-2 and III-1. The detailed descriptions are supported with three dimensional figures. These coupled with the completeness of the hind limb will increase the utility of Australovenator in comparisons with less complete neovenatorid genera. These specimens and the previously described hind limb elements of Australovenator are compared with other theropods classified as neovenatorids (including Neovenator, Chilantaisaurus, Fukuiraptor, Orkoraptor and Megaraptor). Hind limb length proportion comparisons indicate that the smaller neovenatorids Australovenator and Fukuiraptor possess more elongate and gracile hind limb elements than the larger Neovenator and Chilantaisaurus. Greater stride lengths to body size exist in both Fukuiraptor and Australovenator with the femur discovered to be proportionally shorter the rest of the hind limb length. Additionally Australovenator is identified as possessing the most elongate metatarsus. The metatarsus morphology varies with body size. The larger neoventorids possess a metatarsus with greater width but shorter length compared to smaller forms. PMID:23894328

  10. Treatment of hind limb ischemia using angiogenic peptide nanofibers.

    PubMed

    Kumar, Vivek A; Liu, Qi; Wickremasinghe, Navindee C; Shi, Siyu; Cornwright, Toya T; Deng, Yuxiao; Azares, Alon; Moore, Amanda N; Acevedo-Jake, Amanda M; Agudo, Noel R; Pan, Su; Woodside, Darren G; Vanderslice, Peter; Willerson, James T; Dixon, Richard A; Hartgerink, Jeffrey D

    2016-08-01

    For a proangiogenic therapy to be successful, it must promote the development of mature vasculature for rapid reperfusion of ischemic tissue. Whole growth factor, stem cell, and gene therapies have yet to achieve the clinical success needed to become FDA-approved revascularization therapies. Herein, we characterize a biodegradable peptide-based scaffold engineered to mimic VEGF and self-assemble into a nanofibrous, thixotropic hydrogel, SLanc. We found that this injectable hydrogel was rapidly infiltrated by host cells and could be degraded while promoting the generation of neovessels. In mice with induced hind limb ischemia, this synthetic peptide scaffold promoted angiogenesis and ischemic tissue recovery, as shown by Doppler-quantified limb perfusion and a treadmill endurance test. Thirteen-month-old mice showed significant recovery within 7 days of treatment. Biodistribution studies in healthy mice showed that the hydrogel is safe when administered intramuscularly, subcutaneously, or intravenously. These preclinical studies help establish the efficacy of this treatment for peripheral artery disease due to diminished microvascular perfusion, a necessary step before clinical translation. This peptide-based approach eliminates the need for cell transplantation or viral gene transfection (therapies currently being assessed in clinical trials) and could be a more effective regenerative medicine approach to microvascular tissue engineering.

  11. Mechanical constraints on the functional morphology of the gibbon hind limb.

    PubMed

    Channon, Anthony J; Günther, Michael M; Crompton, Robin H; Vereecke, Evie E

    2009-10-01

    Gibbons utilize a number of locomotor modes in the wild, including bipedalism, leaping and, most of all, brachiation. Each locomotor mode puts specific constraints on the morphology of the animal; in some cases these may be complementary, whereas in others they may conflict. Despite several studies of the locomotor biomechanics of gibbons, very little is known about the musculoskeletal architecture of the limbs. In this study, we present quantitative anatomical data of the hind limb for four species of gibbon (Hylobates lar, H. moloch, H. pileatus and Symphalangus syndactylus). Muscle mass and fascicle lengths were obtained from all of the major hind limb muscles and the physiological cross-sectional area was calculated and scaled to remove the effect of body size. The results clearly indicate that, for all of the species studied, the major hip, knee and ankle extensors are short-fascicled and pennate. The major hip and knee flexors, however, are long-fascicled, parallel muscles with relatively small physiological cross-sectional areas. We hypothesize that the short-fascicled muscles could be coupled with a power-amplifying mechanism and are predominantly useful in leaping. The long-fascicled knee and hip flexors are adapted for a wide range of joint postures and can play a role in flexing the legs during brachiation.

  12. A case report of partial bilateral hind limb adactyly in a male lamb.

    PubMed

    Rajabioun, Masoud; Kazemi Mehrjerdi, Hossein; Ghasemi, Samaneh

    2016-01-01

    Hemimelia as a congenital anomaly is a failure of development of extremities formation in embryonic period. This anomaly is defined as complete absence of the part of extremities and different forms were explained for hemimelia. Adactyly is an alternative name for transverse hemimelia and is a rare disorder in the most of animal species. A two months old male lamb with normal vital signs was referred to clinic due to both hind limbs shortness and absence of hooves from the birth day. Clinical and radiological examinations were performed and partial hemimelia was confirmed radiographically in both hind limbs. In left hind limb, total absence of the toe indicated presence of adactyly in this limb. No other congenital deformities were diagnosed in skeletal system based on clinical and radiological examinations. According to our knowledge, this is the first report of such rare conditions in a lamb. Clinical findings and radiological signs of this rare anomaly in a lamb were described in this report.

  13. The role of hind limb flexor muscles during swimming in the toad, Bufo marinus.

    PubMed

    Gillis, Gary B

    2007-01-01

    Most work examining muscle function during anuran locomotion has focused largely on the roles of major hind limb extensors during jumping and swimming. Nevertheless, the recovery phase of anuran locomotion likely plays a critical role in locomotor performance, especially in the aquatic environment, where flexing limbs can increase drag on the swimming animal. In this study, I use kinematic and electromyographic analyses to explore the roles of four anatomical flexor muscles in the hind limb of Bufo marinus during swimming: m. iliacus externus, a hip flexor; mm. iliofibularis and semitendinosus, knee flexors; and m. tibialis anticus longus, an ankle flexor. Two general questions are addressed: (1) What role, if any, do these flexors play during limb extension? and (2) How do limb flexors control limb flexion? Musculus iliacus externus exhibits a large burst of EMG activity early in limb extension and shows low levels of activity during recovery. Both m. iliofibularis and m. semitendinosus are biphasically active, with relatively short but intense bursts during limb extension followed by longer and typically weaker secondary bursts during recovery. Musculus tibialis anticus longus becomes active mid way through recovery and remains active through the start of extension in the next stroke. In conclusion, flexors at all three joints exhibit some activity during limb extension, indicating that they play a role in mediating limb movements during propulsion. Further, recovery is controlled by a complex pattern of flexor activation timing, but muscle intensities are generally lower, suggesting relatively low force requirements during this phase of swimming.

  14. Comparative anatomy and muscle architecture of selected hind limb muscles in the Quarter Horse and Arab.

    PubMed

    Crook, T C; Cruickshank, S E; McGowan, C M; Stubbs, N; Wakeling, J M; Wilson, A M; Payne, R C

    2008-02-01

    The Quarter Horse (bred for acceleration) and the Arab (bred for endurance) are situated at either end of the equine athletic spectrum. Studies into the form and function of the leg muscles in human sprint and endurance runners have demonstrated that differences exist in their muscle architecture. It is not known whether similar differences exist in the horse. Six Quarter Horse and six Arab fresh hind limb cadavers were dissected to gain information on the muscle mass and architecture of the following muscles: gluteus medius; biceps femoris; semitendinosus; vastus lateralis; gastrocnemius; tibialis cranialis and extensor digitorum longus. Specifically, muscle mass, fascicle length and pennation angle were quantified and physiological cross-sectional area (PCSA) and maximum isometric force were estimated. The hind limb muscles of the Quarter Horse were of a significantly greater mass, but had similar fascicle lengths and pennation angles when compared with those of the Arab; this resulted in the Quarter Horse hind limb muscles having greater PCSAs and hence greater isometric force potential. This study suggests that Quarter Horses as a breed inherently possess large strong hind limb muscles, with the potential to accelerate their body mass more rapidly than those of the Arab.

  15. Hind-limb paresis in a dog with paralumbar solitary T-cell lymphoma.

    PubMed

    Ortega, Maria; Castillo-Alcala, Fernanda

    2010-05-01

    A 2-year-old, neutered, male golden retriever was referred to the Ontario Veterinary College, with a 6-week history of hind limb weakness and back pain. Magnetic resonance imaging of the lumbar vertebral column, and histopathology and immunohistochemistry following euthanasia identified an uncommon solitary T-cell lymphoma in the paralumbar area.

  16. Effects of immobilization on rat hind limb muscles under non-weight-bearing conditions

    NASA Technical Reports Server (NTRS)

    Jaspers, Stephen R.; Fagan, Julie M.; Satarug, Soisungwan; Cook, Paul H.; Tischler, Marc E.

    1988-01-01

    The effect of stretched and unstretched immobilization of a hind limb on the concentration and the metabolism of proteins in the hind-limb muscles of rats was investigated. The animals were divided into three groups: (1) weight-bearing controls, (2) tail-cast-suspended, and (3) suspended, with one hind limb immobilized with the ankle in dorsiflexion (30-40 deg angle) and the other freely moving. It was found that unloading the hind limbs for 6 days by tail cast suspension caused soleus to atrophy and reduced growth of the gastrocnemius and plantaris muscles; unloading resulted in a higher degradation rate and lower synthesis rate in both in vitro and in vivo. Chronic stretch of the unloaded soleus not only prevented its atrophy but led to significant hypertrophy, relative to weight-bearing controls, with increases in both the sarcoplasmic and myofibrillar protein fractions. Immobilizing one ankle in dorsiflexion prevented the inhibition of growth in the plantaris and gastrocnemius muscles due to unloading.

  17. A case report of partial bilateral hind limb adactyly in a male lamb

    PubMed Central

    Rajabioun, Masoud; Kazemi Mehrjerdi, Hossein; Ghasemi, Samaneh

    2016-01-01

    Hemimelia as a congenital anomaly is a failure of development of extremities formation in embryonic period. This anomaly is defined as complete absence of the part of extremities and different forms were explained for hemimelia. Adactyly is an alternative name for transverse hemimelia and is a rare disorder in the most of animal species. A two months old male lamb with normal vital signs was referred to clinic due to both hind limbs shortness and absence of hooves from the birth day. Clinical and radiological examinations were performed and partial hemimelia was confirmed radiographically in both hind limbs. In left hind limb, total absence of the toe indicated presence of adactyly in this limb. No other congenital deformities were diagnosed in skeletal system based on clinical and radiological examinations. According to our knowledge, this is the first report of such rare conditions in a lamb. Clinical findings and radiological signs of this rare anomaly in a lamb were described in this report. PMID:28144430

  18. Hind limb malformations in free-living northern leopard frogs (Rana pipiens) from Maine, Minnesota, and Vermont suggest multiple etiologies

    USGS Publications Warehouse

    Meteyer, C.U.; Loeffler, I.K.; Fallon, J.F.; Converse, K.A.; Green, E.; Helgen, J.C.; Kersten, S.; Levey, R.; Eaton-Poole, L.; Burkhart, J.G.

    2000-01-01

    Background Reports of malformed frogs have increased throughout the North American continent in recent years. Most of the observed malformations have involved the hind limbs. The goal of this study was to accurately characterize the hind limb malformations in wild frogs as an important step toward understanding the possible etiologies. Methods During 1997 and 1998, 182 recently metamorphosed northern leopard frogs (Rana pipiens) were collected from Minnesota, Vermont, and Maine. Malformed hind limbs were present in 157 (86%) of these frogs, which underwent necropsy and radiographic evaluation at the National Wildlife Health Center. These malformations are described in detail and classified into four major categories: (1) no limb (amelia); (2) multiple limbs or limb elements (polymelia, polydactyly, polyphalangy); (3) reduced limb segments or elements (phocomelia, ectromelia, ectrodactyly, and brachydactyly; and (4) distally complete but malformed limb (bone rotations, bridging, skin webbing, and micromelia). Results Amelia and reduced segments and/or elements were the most common finding. Frogs with bilateral hind limb malformations were not common, and in only eight of these 22 frogs were the malformations symmetrical. Malformations of a given type tended to occur in frogs collected from the same site, but the types of malformations varied widely among all three states, and between study sites within Minnesota. Conclusions Clustering of malformation type suggests that developmental events may produce a variety of phenotypes depending on the timing, sequence, and severity of the environmental insult. Hind limb malformations in free-living frogs transcend current mechanistic explanations of tetrapod limb development.

  19. Reinnervation of hind limb extremity after lumbar dorsal root ganglion injury.

    PubMed

    Liu, Song; Bréjot, Thomas; Cressant, Arnaud; Bacci, Josette; Saïd, Gérard; Tadié, Marc; Heard, Jean Michel

    2005-12-01

    Loss of dorsal root ganglion neuron, or injury to dorsal roots, induces permanent somatosensory defect without therapeutic option. We explored an approach to restoring hind limb somatosensory innervation after elimination of L4, L5 and L6 dorsal root ganglion neurons in rats. Somatosensory pathways were reconstructed by connecting L4, L5 and L6 lumbar dorsal roots to T10, T11 and T12 intercostal nerves, respectively, thus allowing elongation of thoracic ganglion neuron peripheral axons into the sciatic nerve. Connection of thoracic dorsal root ganglion neurons to peripheral tissues was documented 4 and 7 months after injury. Myelinated and unmyelinated fibers regrew in the sciatic nerve. Nerve terminations expressing calcitonin-gene-related-peptide colonized the footpad skin. Retrograde tracing showed that T10, T11 and T12 dorsal root ganglion neurons expressing calcitonin-gene-related-peptide or the neurofilament RT97 projected axons to the sciatic nerve and the footpad skin. Recording of somatosensory evoked potentials in the upper spinal cord indicated connection between the sciatic nerve and the central nervous system. Hind limb retraction in response to nociceptive stimulation of the reinnervated footpads and reversion of skin lesions suggested partial recovery of sensory function. Proprioceptive defects persisted. Delayed somatosensory reinnervation of the hind limb after destruction of lumbar dorsal root neurons in rats indicates potential approaches to reduce chronic disability after severe injury to somatosensory pathways.

  20. Identifying risk factors for poor hind limb cleanliness in Danish loose-housed dairy cows.

    PubMed

    Nielsen, B H; Thomsen, P T; Sørensen, J T

    2011-08-01

    The objective of this study was to identify possible risk factors for poor cow hind limb cleanliness in Danish loose-housed, lactating dairy cows. The study was conducted as a cross-sectional study of 1315 cows in 42 commercial Danish dairy herds with primarily Danish Holstein cows. The effect of four cow-level factors (parity, days in milk, daily lying time and lameness) and eight herd-level factors (herd size, milk production, milking system, floor type, access to pasture grazing, floor scraping frequency, hoof bathing frequency and hoof washing frequency) on the risk of having dirtier hind limbs were analysed using ordinal logistic regression fitting a proportional odds model. Cow hind limb cleanliness was scored using an ordinal score from 1 to 4: 1 being clean and 4 being covered in dirt. The odds ratios (ORs) estimated from the proportional odds model depict the effect of a risk factor on the odds of having a higher rather than a lower cleanliness score. First parity cows had an increased risk of being dirtier compared with third parity or older cows (OR=1.70). Compared with late lactation, early and mid lactation were associated with an increased risk of being dirtier (OR=2.07 and 1.33, respectively). Decreasing the daily time lying by 30 min was associated with an increased risk of being dirtier (OR=1.05). Furthermore, an increased risk of being dirtier was found in herds with no pasture access (OR=3.75).

  1. Disparate Igf1 expression and growth in the fore- and hind limbs of a marsupial mammal (Monodelphis domestica).

    PubMed

    Sears, Karen E; Patel, Ankit; Hübler, Merla; Cao, Xiaoyi; Vandeberg, John L; Zhong, Sheng

    2012-06-01

    Proper regulation of growth is essential to all stages of life, from development of the egg into an embryo to the maintenance of normal cell cycle progression in adults. However, despite growth's importance to basic biology and health, little is known about how mammalian growth is regulated. In this study, we investigated the molecular basis of the highly disparate growth of opossum fore- and hind limbs in utero. We first used a novel, opossum-specific microarray to identify several growth-related genes that are differentially expressed in opossum fore- and hind limbs of comparable developmental stages. These genes included Igf1. Given Igf1's role in the growth of other systems, we further investigated the role of Igf1 in opossum limb growth. Supporting the microarray results, RT-PCR indicated that Igf1 levels are approximately two times higher in opossum fore- than hind limbs. Consistent with this, while Igf1 transcripts were readily detectable in opossum forelimbs using whole-mount in situ hybridization, they were not detectable in opossum hind limbs. Furthermore, opossum limbs treated with exogenous Igf1 protein experienced significantly greater cellular proliferation and growth than control limbs in vitro. Taken together, results suggest that the differential expression of Igf1 in developing opossum limbs contributes to their divergent rate of growth, and the unique limb phenotype of opossum newborns. This study establishes the opossum limb as a new mammalian model system for study of organ growth.

  2. Imaging receptor for advanced glycation end product expression in mouse model of hind limb ischemia

    PubMed Central

    2013-01-01

    Background The purpose of this study is to image the effect of diabetes on expression of receptor for advanced glycation endproducts (RAGE) in limb ischemia in live animals. Methods Male wild-type C57BL/6 mice were either made diabetic or left as control. Two months later, diabetic and non-diabetic mice underwent left femoral artery ligation. The right leg served as lesion control. Five days later, mice were injected with 15.1 ± 4.4 MBq 99mTc-anti-RAGE F(ab’)2 and 4 to 5 h later (blood pool clearance) underwent SPECT/CT imaging. At the completion of imaging, mice were euthanized, hind limbs counted and sectioned, and scans reconstructed. Regions of interest were drawn on serial transverse sections comprising the hind limbs and activity in millicuries summed and divided by the injected dose (ID). Quantitative histology was performed for RAGE staining and angiogenesis. Results Uptake of 99mTc-anti-RAGE F(ab')2 as %ID × 10−3 was higher in the left (ischemic) limbs for the diabetic mice (n = 8) compared to non-diabetic mice (n = 8) (1.20 ± 0.44% vs. 0.49 ± 0.40%; P = 0.0007) and corresponded to less angiogenesis in the diabetic mice. Uptake was also higher in the right limbs of diabetic compared to non-diabetic animals (0.82 ± 0.33% vs. 0.40 ± 0.14%; P = 0.0004). Conclusions These data show the feasibility of imaging and quantifying the effect of diabetes on RAGE expression in limb ischemia. PMID:23663412

  3. Hind limb unloading, a model of spaceflight conditions, leads to decreased B lymphopoiesis similar to aging.

    PubMed

    Lescale, Chloé; Schenten, Véronique; Djeghloul, Dounia; Bennabi, Meriem; Gaignier, Fanny; Vandamme, Katleen; Strazielle, Catherine; Kuzniak, Isabelle; Petite, Hervé; Dosquet, Christine; Frippiat, Jean-Pol; Goodhardt, Michele

    2015-02-01

    Within the bone marrow, the endosteal niche plays a crucial role in B-cell differentiation. Because spaceflight is associated with osteoporosis, we investigated whether changes in bone microstructure induced by a ground-based model of spaceflight, hind limb unloading (HU), could affect B lymphopoiesis. To this end, we analyzed both bone parameters and the frequency of early hematopoietic precursors and cells of the B lineage after 3, 6, 13, and 21 d of HU. We found that limb disuse leads to a decrease in both bone microstructure and the frequency of B-cell progenitors in the bone marrow. Although multipotent hematopoietic progenitors were not affected by HU, a decrease in B lymphopoiesis was observed as of the common lymphoid progenitor (CLP) stage with a major block at the progenitor B (pro-B) to precursor B (pre-B) cell transition (5- to 10-fold decrease). The modifications in B lymphopoiesis were similar to those observed in aged mice and, as with aging, decreased B-cell generation in HU mice was associated with reduced expression of B-cell transcription factors, early B-cell factor (EBF) and Pax5, and an alteration in STAT5-mediated IL-7 signaling. These findings demonstrate that mechanical unloading of hind limbs results in a decrease in early B-cell differentiation resembling age-related modifications in B lymphopoiesis.

  4. COORDINATED, MULTI-JOINT, FATIGUE-RESISTANT FELINE STANCE PRODUCED WITH INTRAFASCICULAR HIND LIMB NERVE STIMULATION

    PubMed Central

    Normann, R A; Dowden, B R; Frankel, M A; Wilder, A M; Hiatt, S D; Ledbetter, N M; Warren, D A; Clark, G A

    2012-01-01

    The production of graceful skeletal movements requires coordinated activation of multiple muscles that produce torques around multiple joints. The work described herein is focused on one such movement, stance, that requires coordinated activation of extensor muscles acting around the hip, knee and ankle joints. The forces evoked in these muscles by external stimulation all have a complex dependence on muscle length and shortening velocities, and some of these muscles are bi-articular. In order to recreate sit-to-stand maneuvers in the anesthetized feline, we excited the hind limb musculature using intrafascicular multielectrode stimulation (IFMS) of the muscular branch of the sciatic nerve, the femoral nerve, and the main branch of the sciatic nerve. Stimulation was achieved with either acutely or chronically implanted Utah Slanted Electrode Arrays (USEAs) via subsets of electrodes 1) that activated motor units in the extensor muscles of the hip, knee, and ankle joints, 2) that were able to evoke large extension forces, and 3) that manifested minimal coactivation of the targeted motor units. Three hind limb force-generation strategies were investigated, including sequential activation of independent motor units to increase force, and interleaved or simultaneous IFMS of three sets of six or more USEA electrodes that excited the hip, knee, and ankle extensors. All force-generation strategies evoked stance, but the interleaved IFMS strategy also reduced muscle fatigue produced by repeated sit-to-stand maneuvers compared with fatigue produced by simultaneous activation of different motor neuron pools. These results demonstrate the use of interleaved IFMS as a means to recreate coordinated, fatigue-resistant multi-joint muscle forces in the unilateral hind limb. This muscle activation paradigm could provide a promising neuroprosthetic approach for the restoration of sit-to-stand transitions in individuals who are paralyzed by spinal cord injury, stroke, or disease. PMID

  5. Coordinated, multi-joint, fatigue-resistant feline stance produced with intrafascicular hind limb nerve stimulation

    NASA Astrophysics Data System (ADS)

    Normann, R. A.; Dowden, B. R.; Frankel, M. A.; Wilder, A. M.; Hiatt, S. D.; Ledbetter, N. M.; Warren, D. A.; Clark, G. A.

    2012-04-01

    The production of graceful skeletal movements requires coordinated activation of multiple muscles that produce torques around multiple joints. The work described herein is focused on one such movement, stance, that requires coordinated activation of extensor muscles acting around the hip, knee and ankle joints. The forces evoked in these muscles by external stimulation all have a complex dependence on muscle length and shortening velocities, and some of these muscles are biarticular. In order to recreate sit-to-stand maneuvers in the anesthetized feline, we excited the hind limb musculature using intrafascicular multielectrode stimulation (IFMS) of the muscular branch of the sciatic nerve, the femoral nerve and the main branch of the sciatic nerve. Stimulation was achieved with either acutely or chronically implanted Utah Slanted Electrode Arrays (USEAs) via subsets of electrodes (1) that activated motor units in the extensor muscles of the hip, knee and ankle joints, (2) that were able to evoke large extension forces and (3) that manifested minimal coactivation of the targeted motor units. Three hind limb force-generation strategies were investigated, including sequential activation of independent motor units to increase force, and interleaved or simultaneous IFMS of three sets of six or more USEA electrodes that excited the hip, knee and ankle extensors. All force-generation strategies evoked stance, but the interleaved IFMS strategy also reduced muscle fatigue produced by repeated sit-to-stand maneuvers compared with fatigue produced by simultaneous activation of different motor neuron pools. These results demonstrate the use of interleaved IFMS as a means to recreate coordinated, fatigue-resistant multi-joint muscle forces in the unilateral hind limb. This muscle activation paradigm could provide a promising neuroprosthetic approach for the restoration of sit-to-stand transitions in individuals who are paralyzed by spinal cord injury, stroke or disease.

  6. Muscular reconstruction and functional morphology of the hind limb of santacrucian (Early Miocene) sloths (Xenarthra, Folivora) of Patagonia.

    PubMed

    Toledo, Néstor; Bargo, M Susana; Vizcaíno, Sergio F

    2015-05-01

    This article presents a morphofunctional analysis of the hind limb of Santacrucian (Early Miocene) sloths from southernmost Patagonia (Argentina). These fossil sloths were mid sized to large animals, ranging from 40 to 120 kg, and their postcranial skeleton was markedly different in shape compared with that of extant tree sloths, which vary from 2 to 10 kg. The functional anatomy of the hind limb of Santacrucian sloths was compared with that of living xenarthrans (tree sloths, anteaters, and armadillos), which involved reconstruction of the hind limb musculature and comparative and qualitative morphofunctional analyses, and hypotheses on the biological role of the hind limb in terms of preferences in substrate, posture, and strategies of locomotion were formulated. The hind limb of Santacrucian sloths bears strong resemblances to that of living South American anteaters in stoutness of skeletal elements, form of the characteristics related to muscular and ligamentous attachments, and conservative, pentadactylous strong-clawed pes. The musculature was very well developed, allowing powerful forces, principally in entire limb adduction, crus flexion and extension, pes extension, and toe prehension. These functional features, together with those of the forelimb, are congruent with climbing behavior, and support the hypothesis that Santacrucian sloths were good but slow climbing mammals. However, their climbing strategies were limited, owing principally to their comparatively large body size, and they relied to a large extent on their powerful musculature and curved manual and pedal unguals for both moving and standing on the arboreal supports.

  7. The effect of baclofen on the hind limb flexor reflex of the spinal rat.

    PubMed

    Sypniewska, M

    1979-01-01

    The effect of baclofen on the hind limb flexor reflex of the spinal rat was studied. Baclofen inhibited the flexor reflex, this effect not being antagonized by picrotoxin and bicuculline. Baclofen reduced the stimulating action of quipazine and LSD, had no effect on the clonidine-induced reflex stimulation, but inhibited the flexor reflex stimulation induced by amphetamine and fenfluramine. The results obtained bring forth some doubts as to the GABA-mimetic action of baclofen. The action of baclofen on the spinal cord seems to be directed mainly to the presynaptic part of the noradrenergic and serotonergic systems.

  8. Combined effects of soy isoflavones and milk basic protein on bone mineral density in hind-limb unloaded mice

    PubMed Central

    Matsumoto, Yu; Tousen, Yuko; Nishide, Yoriko; Tadaishi, Miki; Kato, Ken; Ishimi, Yoshiko

    2016-01-01

    We examined whether the combination of isoflavone and milk basic protein both are reported to be effective for bone metabolism, prevents bone loss induced by skeletal hind-limb unloading in mice. Female ddY strain mice, aged 8 weeks, were divided into six groups (n = 6–8 each): (1) normally housed group, (2) loading group, (3) hind-limb unloading group fed a control diet, (4) hind-limb unloading group fed a 0.2% isoflavone conjugates diet, (5) hind-limb unloading group fed a 1.0% milk basic protein diet, and (6) hind-limb unloading group fed a 0.2% isoflavone conjugates and 1.0% milk basic protein diet. After 3 weeks, femoral bone mineral density was markedly reduced in unloading mice. The combination of isoflavone and milk basic protein showed cooperative effects in preventing bone loss and milk basic protein inhibited the increased expression of osteogenic genes in bone marrow cells in unloading mice. These results suggest that the combination of soy isoflavone and milk basic protein may be useful for bone health in subjects with disabling conditions as well as astronauts. PMID:27013781

  9. Perivertebral B-cell lymphoma in a Queensland koala (Phascolarctos cinereus adustus) with paralytic symptoms in the hind limbs.

    PubMed

    Kido, Nobuhide; Edamura, Kazuya; Inoue, Naomi; Shibuya, Hisashi; Sato, Tsuneo; Kondo, Masako; Shindo, Izumi

    2012-08-01

    A male Queensland koala (Phascolarctos cinereus adustus) at Kanazawa Zoological Gardens (Kanagawa, Japan) exhibited paralytic symptoms in the hind limbs. Computed tomography and magnetic resonance imaging revealed a mass on the left ventral side of the 11th to 13th thoracic vertebrae, and the presence of myelitis or edema in the spinal cord. The koala was under anesthesia during the examination and suddenly developed ventricular fibrillation and died. Necropsy revealed a firm flat ovoid hemorrhagic mass on the vertebrae. Following a microscopic examination including immunohistochemistry, the perivertebral mass was diagnosed as B cell lymphoma. Therefore, neoplastic cell infiltration into the spinal cord may cause paralytic symptoms in the hind limbs.

  10. The development of functional innervation in the hind limb of the chick embryo.

    PubMed Central

    Landmesser, L; Morris, D G

    1975-01-01

    1. The development of functional motor innervation was studied in the hind limb of chick embryos from Stages 25 to 43 by observing contraction of individual muscles and by recording the resultant tension when individual spinal nerves were electrically stimulated. 2. At later developmental stages (35-43) a given muscle always received functional innervation from specific spinal nerves. This pattern, with respect to the craniocaudal position of motoneurones, was similar to those described for amphibians and mammals. 3. The observed pattern was similar throughout development from the time that movement could first be elicited at Stages 27-28. There was no indication that motoneurones form initial synapses with inappropriate muscles. 4. Recordings from muscle nerves during excitation of individual spinal nerves gave results similar to the tension recordings, showing that even at early developmental stages muscle nerves did not contain substantial numbers of inappropriate axons. 5. Most limb muscles or primitive muscle masses became functionally innervated at the same time with no clearly defined proximo-distal sequence of limb innervation. 6. It appears that chick motoneurones are initially specified with respect to their peripheral destination and grow out selectively to synapse with appropriate muscles from the outset. PMID:1177095

  11. FACS-based Satellite Cell Isolation From Mouse Hind Limb Muscles.

    PubMed

    Gromova, Anastasia; Tierney, Matthew T; Sacco, Alessandra

    2015-08-20

    Fluorescence Activated Cell Sorting (FACS) is a sensitive and accurate method for purifying satellite cells, or muscle stem cells, from adult mouse skeletal muscle (Liu et al., 2013; Sacco et al., 2008; Tierney et al., 2014). Mechanical and enzymatic digestion of hind limb muscles releases mononuclear muscle cells into suspension. This protocol employs fractionation strategies to deplete cells expressing the cell surface markers CD45, CD31, CD11b and Ly-6A/E-Sca1, both by magnetic separation and FACS-based exclusion, and positively select for cells expressing a7-integrin and CD34. This enables the researcher to successfully enrich satellite cells that uniformly express the paired-box transcription factor Pax7 and are capable of long-term self-renewal, skeletal muscle repair and muscle stem cell pool repopulation.

  12. Effect of demedullation on freezing injury in hind limbs of rats

    NASA Astrophysics Data System (ADS)

    Dhingra, Shashi; Bhatia, B.; Chhina, G. S.; Singh, Baldev

    1987-09-01

    Freezing incidence and tissue loss on exposure of hind limbs of female Wistar rats to freezing mixture was reduced by demedullation 6 days prior to cold exposure (p<0.01 and p<0.001 respectively); demedullation 1 h after freezing injury had no effect on tissue loss. Noradrenaline (1 mg/kg i.p.) 5 min before exposure increased the freezing incidence in intact (p<0.05) as well as in demedullated rats (p<0.01), with no effect on tissue loss. Adrenaline (500 mg/kg i.p.) had no effect on either. A sustained fall in plasma adrenaline after demedullation leading to reduced reactivity of the blood vessels to some vasoactive agents is postulated.

  13. 3D reconstruction of digitized histological sections for vasculature quantification in the mouse hind limb

    NASA Astrophysics Data System (ADS)

    Xu, Yiwen; Pickering, J. Geoffrey; Nong, Zengxuan; Gibson, Eli; Ward, Aaron D.

    2014-03-01

    In contrast to imaging modalities such as magnetic resonance imaging and micro computed tomography, digital histology reveals multiple stained tissue features at high resolution (0.25μm/pixel). However, the two-dimensional (2D) nature of histology challenges three-dimensional (3D) quantification and visualization of the different tissue components, cellular structures, and subcellular elements. This limitation is particularly relevant to the vasculature, which has a complex and variable structure within tissues. The objective of this study was to perform a fully automated 3D reconstruction of histology tissue in the mouse hind limb preserving the accurate systemic orientation of the tissues, stained with hematoxylin and immunostained for smooth muscle α actin. We performed a 3D reconstruction using pairwise rigid registrations of 5μm thick, paraffin-embedded serial sections, digitized at 0.25μm/pixel. Each registration was performed using the iterative closest points algorithm on blood vessel landmarks. Landmarks were vessel centroids, determined according to a signed distance map of each pixel to a decision boundary in hue-saturation-value color space; this decision boundary was determined based on manual annotation of a separate training set. Cell nuclei were then automatically extracted and corresponded to refine the vessel landmark registration. Homologous nucleus landmark pairs appearing on not more than two adjacent slides were chosen to avoid registrations which force curved or non-sectionorthogonal structures to be straight and section-orthogonal. The median accumulated target registration errors ± interquartile ranges for the vessel landmark registration, and the nucleus landmark refinement were 43.4+/-42.8μm and 2.9+/-1.7μm, respectively (p<0.0001). Fully automatic and accurate 3D rigid reconstruction of mouse hind limb histology imaging is feasible based on extracted vasculature and nuclei.

  14. Investigating the involvement of TRPV1 ion channels in remote hind limb preconditioning-induced cardioprotection in rats.

    PubMed

    Randhawa, Puneet Kaur; Jaggi, Amteshwar Singh

    2017-02-01

    Remote ischemic preconditioning (RIPC) treatment strategy is a breakthrough in the field of cardiovascular pharmacology as it has the potential to attenuate myocardial ischemia-reperfusion injury. However, the underlying intracellular pathways have not been widely explored. The present study intends to explore the possible role of TRPV1 channels in mediating remote hind limb preconditioning-induced cardioprotection. Remote hind limb preconditioning stimulus (4 cycles in succession) was delivered by tying the blood pressure cuff at the inguinal level of the rat. The Langendorff system was used to perfuse the isolated heart and afterward was subjected to 30 min of global ischemia and 120 min of reperfusion. Sustained ischemia and, thereafter, reperfusion led to cardiac injury that was assessed in terms of infarct size, lactate dehydrogenase (LDH) release, creatine kinase (CK) release, left ventricular end diastolic pressure (LVEDP), left ventricular developed pressure (LVDP), +dp/dtmax, -dp/dtmin, heart rate, rate pressure product, and coronary flow rate. The pharmacological modulators employed included capsaicin as TRPV1 agonist and capsazepine as TRPV1 antagonist. Remote hind limb preconditioning stimulus and capsaicin preconditioning (5 and 10 mg/kg) led to significant reduction in infarct size, LVEDP, LDH release, CK release, and significant improvement in LVDP, +dp/dtmax, -dp/dtmin, heart rate, rate pressure product, and coronary flow rate. However, remote hind limb preconditioning-induced cardioprotective effects were considerably abolished in the presence of capsazepine (2.5 and 5 mg/kg). This indicates that remote hind limb preconditioning stimulus possibly activates TRPV1 channels to produce cardioprotective effects.

  15. The development of motor projection patterns in the chick hind limb.

    PubMed Central

    Landmesser, L

    1978-01-01

    1. Retrograde transport of horseradish peroxidase was used to map the initial projection patterns of lumbosacral motoneurones to the embryonic chick hind limb. 2. The stage 28 segmental projection pattern to each of the four primary muscle masses was characteristic and indistinguishable from the stage 36 projection pattern to the sum of the muscles derived from that mass. In addition, the adductor motoneurone pool was found to be similar in position (both rostro-caudal and mediolateral) at stages 29, 30, 32, 33 1/2 and 36. 3. Therefore axons from lumbosacral motoneurones project for the most part only to appropriate regions from early times shortly after they grow into the limb bud. Furthermore, the attainment of the segmental projection pattern occurs prior to the normal time of, and therefore without the aid of, cell death. This conclusion was supported by electrophysiological recordings made from muscle nerves. 4. A regionalization of the projection patterns within a single muscle mass could be shown both anatomically and physiologically prior to the cleavage of the mass into individual muscles and the projections were in a general way appropriate for the muscles derived from those regions. 5. Therefore the process of muscle cleavage does not in itself create the specific projection patterns observed, and motoneurone axons appear to grow to and to ramify and make synapses only within regions which correspond to their adult muscles. 6. Finally, the termination site of each motoneurone axon in the early limb was found to be tightly correlated in a somatotopic fashion with the position occupied by its soma in the cord. This suggests that some feature of the motoneurone related to its position may be of importance in achieving the specific projection patterns observed. Images Plate 1 PMID:731552

  16. A Reproducible Radiation Delivery Method for Unanesthetized Rodents during Periods of Hind Limb Unloading

    PubMed Central

    Walb, M.C.; Black, P.J.; Payne, V.S.; Munley, M.T.; Willey, J.S.

    2015-01-01

    Exposure to the spaceflight environment has long been known to be a health challenge concerning many body systems. Both microgravity and/or ionizing radiation can cause acute and chronic effects in multiple body systems. The hind limb unloaded (HLU) rodent model is a ground-based analogue for microgravity that can be used to simulate and study the combined biologic effects of reduced loading with spaceflight radiation exposure. However, studies delivering radiation to rodents during periods of HLU are rare. Herein we report the development of an irradiation protocol using a clinical linear accelerator that can be used with hind limb unloaded, unanesthetized rodents that is capable of being performed at most academic medical centers. A 30.5 cm × 30.5 cm × 40.6 cm rectangular chamber was constructed out of polymethyl methacrylate (PMMA) sheets (0.64 cm thickness). Five cm of water-equivalent material were placed outside of two PMMA inserts on either side of the rodent that permitted the desired radiation dose buildup (electronic equilibrium) and helped to achieve a flatter dose profile. Perforated aluminum strips permitted the suspension dowel to be placed at varying heights depending on the rodent size. Radiation was delivered using a medical linear accelerator at an accelerating potential of 10 MV. A calibrated PTW Farmer ionization chamber, wrapped in appropriately thick tissue-equivalent bolus material to simulate the volume of the rodent, was used to verify a uniform dose distribution at various regions of the chamber. The dosimetry measurements confirmed variances typically within 3%, with maximum variance <10% indicated through optically stimulated luminescent dosimeter (OSLD) measurements, thus delivering reliable spaceflight-relevant total body doses and ensuring a uniform dose regardless of its location within the chamber. Due to the relative abundance of LINAC’s at academic medical centers and the reliability of their dosimetry properties, this method

  17. A reproducible radiation delivery method for unanesthetized rodents during periods of hind limb unloading

    NASA Astrophysics Data System (ADS)

    Walb, M. C.; Black, P. J.; Payne, V. S.; Munley, M. T.; Willey, J. S.

    2015-07-01

    Exposure to the spaceflight environment has long been known to be a health challenge concerning many body systems. Both microgravity and/or ionizing radiation can cause acute and chronic effects in multiple body systems. The hind limb unloaded (HLU) rodent model is a ground-based analogue for microgravity that can be used to simulate and study the combined biologic effects of reduced loading with spaceflight radiation exposure. However, studies delivering radiation to rodents during periods of HLU are rare. Herein we report the development of an irradiation protocol using a clinical linear accelerator that can be used with hind limb unloaded, unanesthetized rodents that is capable of being performed at most academic medical centers. A 30.5 cm × 30.5 cm × 40.6 cm rectangular chamber was constructed out of polymethyl methacrylate (PMMA) sheets (0.64 cm thickness). Five centimeters of water-equivalent material were placed outside of two PMMA inserts on either side of the rodent that permitted the desired radiation dose buildup (electronic equilibrium) and helped to achieve a flatter dose profile. Perforated aluminum strips permitted the suspension dowel to be placed at varying heights depending on the rodent size. Radiation was delivered using a medical linear accelerator at an accelerating potential of 10 MV. A calibrated PTW Farmer ionization chamber, wrapped in appropriately thick tissue-equivalent bolus material to simulate the volume of the rodent, was used to verify a uniform dose distribution at various regions of the chamber. The dosimetry measurements confirmed variances typically within 3%, with maximum variance <10% indicated through optically stimulated luminescent dosimeter (OSLD) measurements, thus delivering reliable spaceflight-relevant total body doses and ensuring a uniform dose regardless of its location within the chamber. Due to the relative abundance of LINACs at academic medical centers and the reliability of their dosimetry properties, this

  18. Effects of Hind Limb Unloading on Pharmacokinetics of Procainamide in Mice

    NASA Technical Reports Server (NTRS)

    Risin, Semyon A.; Dasgupta, Amitava; Ramesh, Govindarajan T.; Risin, Diana

    2007-01-01

    The pharmacokinetics (PK) of medications administered to astronauts could be altered by the conditions in space. It is prudent to expect that low gravity and free floating (and associated hemodynamic changes) could affect the absorption, distribution, metabolism and excretion of the drugs. Knowledge of these alterations is essential for adjusting the dosage and the regimen of drug administration. Among the medications of special interest are the cardiovascular drugs, especially the antiarrhythmic agents. In this study we used hind limb unloaded (HLU) mice as a model to investigate possible changes in the PK of a common antiarrhythmic drug procainamide (PA). Prior to drug administration the experimental animals were tail suspended for 24 hours and the control animals were kept free. PA (150-250 mg per kg) was given orally by a gavage procedure. After that the experimental mice were kept suspended for additional 1, 2, 3 and 6 hours. At these time points the serum concentration of PA and N-acetyl-procainamide (NAPA), an active metabolite which is formed by N-acetyltransferase in the liver, were measured by the fluorescence polarization immunoassay (FPIA) on the AxSYM autoanalyzer (Abbott Laboratories, Abbott Park, IL). The serum level of PA in HLU mice at 1 hour after administration was almost 40% lower than in controls. At 2-3 hours the difference still maintained, however, it was not statistically significant; at 6 hours no difference was detected. The level of NAPA in HLU mice was slightly lower at 1 and 2 hours but the difference did not reach statistical significance. The estimated PA half-life time in HLU mice was almost 55% longer than in control animals. These results confirm that hind limb unloading and related hemodynamic changes significantly alter the PK of PA. The effects are most likely primarily associated with a decrease in the drug absorption, especially within the first two hours after administration. At the same time prolongation of the PA half

  19. A reproducible radiation delivery method for unanesthetized rodents during periods of hind limb unloading.

    PubMed

    Walb, M C; Black, P J; Payne, V S; Munley, M T; Willey, J S

    2015-07-01

    Exposure to the spaceflight environment has long been known to be a health challenge concerning many body systems. Both microgravity and/or ionizing radiation can cause acute and chronic effects in multiple body systems. The hind limb unloaded (HLU) rodent model is a ground-based analogue for microgravity that can be used to simulate and study the combined biologic effects of reduced loading with spaceflight radiation exposure. However, studies delivering radiation to rodents during periods of HLU are rare. Herein we report the development of an irradiation protocol using a clinical linear accelerator that can be used with hind limb unloaded, unanesthetized rodents that is capable of being performed at most academic medical centers. A 30.5 cm×30.5 cm×40.6 cm30.5 cm×30.5 cm×40.6 cm rectangular chamber was constructed out of polymethyl methacrylate (PMMA) sheets (0.64 cm thickness). Five centimeters of water-equivalent material were placed outside of two PMMA inserts on either side of the rodent that permitted the desired radiation dose buildup (electronic equilibrium) and helped to achieve a flatter dose profile. Perforated aluminum strips permitted the suspension dowel to be placed at varying heights depending on the rodent size. Radiation was delivered using a medical linear accelerator at an accelerating potential of 10 MV. A calibrated PTW Farmer ionization chamber, wrapped in appropriately thick tissue-equivalent bolus material to simulate the volume of the rodent, was used to verify a uniform dose distribution at various regions of the chamber. The dosimetry measurements confirmed variances typically within 3%, with maximum variance <10% indicated through optically stimulated luminescent dosimeter (OSLD) measurements, thus delivering reliable spaceflight-relevant total body doses and ensuring a uniform dose regardless of its location within the chamber. Due to the relative abundance of LINACs at academic medical centers and the reliability of their

  20. Three-dimensional kinematics of the pelvis and hind limbs in chimpanzee (Pan troglodytes) and human bipedal walking.

    PubMed

    O'Neill, Matthew C; Lee, Leng-Feng; Demes, Brigitte; Thompson, Nathan E; Larson, Susan G; Stern, Jack T; Umberger, Brian R

    2015-09-01

    The common chimpanzee (Pan troglodytes) is a facultative biped and our closest living relative. As such, the musculoskeletal anatomies of their pelvis and hind limbs have long provided a comparative context for studies of human and fossil hominin locomotion. Yet, how the chimpanzee pelvis and hind limb actually move during bipedal walking is still not well defined. Here, we describe the three-dimensional (3-D) kinematics of the pelvis, hip, knee and ankle during bipedal walking and compare those values to humans walking at the same dimensionless and dimensional velocities. The stride-to-stride and intraspecific variations in 3-D kinematics were calculated using the adjusted coefficient of multiple correlation. Our results indicate that humans walk with a more stable pelvis than chimpanzees, especially in tilt and rotation. Both species exhibit similar magnitudes of pelvis list, but with segment motion that is opposite in phasing. In the hind limb, chimpanzees walk with a more flexed and abducted limb posture, and substantially exceed humans in the magnitude of hip rotation during a stride. The average stride-to-stride variation in joint and segment motion was greater in chimpanzees than humans, while the intraspecific variation was similar on average. These results demonstrate substantial differences between human and chimpanzee bipedal walking, in both the sagittal and non-sagittal planes. These new 3-D kinematic data are fundamental to a comprehensive understanding of the mechanics, energetics and control of chimpanzee bipedalism.

  1. Influence of 14-day hind limb unloading on isolated muscle spindle activity in rats.

    PubMed

    Zhao, Xue Hong; Fan, Xiao Li; Song, Xin Ai; Wu, Su Di; Ren, Jun Chan; Chen, Ming Xia

    2010-09-01

    During hind limb unloading (HU), the soleus is often in a shortened position and the natural physiological stimulus of muscle spindles is altered, such that muscle spindle activity also changes. Using isolated spindle conditions, the present study investigates the electrophysiological activity and ultrastructure of muscle spindles following HU. Results show that muscle spindle discharges fall into either of two main patterns, single spikes or spike clusters in shortened positions, with a steady frequency of 18-38 spikes/s (mean 29.08 +/- 2.45) in an extended position. Following 14-day HU, afferent discharge activity was significantly altered in soleus muscle spindles. Duration of individual spikes was significantly prolonged, from 0.54 +/- 0.05 ms for control rats to 1.53 +/- 0.25 ms for rats in the HU group. In a shortened position, regular rhythm afferent discharges were obviously depressed, and the majority of muscle spindles became silent, while in an extended position, the discharges remained continuous but with decreased frequency. Results also show that the ultrastructure of muscle spindles experience degenerative changes during HU. Altered muscle spindle afference could possibly modify the activity of motor neurons and further affect the activity of extrafusal fibers.

  2. Du-zhong (Eucommia ulmoides) prevents disuse-induced osteoporosis in hind limb suspension rats.

    PubMed

    Pan, Yalei; Niu, Yinbo; Li, Chenrui; Zhai, Yuankun; Zhang, Rong; Guo, Xin; Mei, Qibing

    2014-01-01

    Du-Zhong has a long history of being used in traditional Chinese formulas to treat bone related diseases. The objective of the present study is to systematically investigate the effects of Du-Zhong cortex extract (DZCE) on disuse-induced osteoporosis. Rats were randomly divided into four groups, and three groups were treated with hind limb suspension (HLS). Control and HLS group received deionized distilled water, while the other two groups received alendronate (2.0 mg/kg/day) and DZCE (300 mg/kg/day) respectively by intragastric gavage for six weeks (two weeks prior to and during the four weeks of HLS). Dual-energy X-ray absorptiometry, assay of biochemical markers, and three-point bending test were employed to determine the effect of various treatments on bone mass, turnover, and strength. The trabecular bone microarchitecture was assessed by microCT analysis. DZCE could effectively prevent the bone loss induced by HLS, which was indicated by decreased levels of bone turnover markers as well as the changes in urinary calcium and phosphorus. The DZCE treatment also enhanced the biomechanical strength of bone and prevented the deterioration of trabecular bone microarchitecture. DZCE administration was able to prevent disuse-induced osteoporosis by regulating the bone metabolism, suggesting that DZCE could be used as an alternative therapy for the prevention of disuse-induced osteoporosis.

  3. Muscle moment arms of the gibbon hind limb: implications for hylobatid locomotion.

    PubMed

    Channon, Anthony J; Crompton, Robin H; Günther, Michael M; Vereecke, Evie E

    2010-04-01

    Muscles facilitate skeletal movement via the production of a torque or moment about a joint. The magnitude of the moment produced depends on both the force of muscular contraction and the size of the moment arm used to rotate the joint. Hence, larger muscle moment arms generate larger joint torques and forces at the point of application. The moment arms of a number of gibbon hind limb muscles were measured on four cadaveric specimens (one Hylobates lar, one H. moloch and two H. syndactylus). The tendon travel technique was used, utilizing an electro-goniometer and a linear voltage displacement transducer. The data were analysed using a technique based on a differentiated cubic spline and normalized to remove the effect of body size. The data demonstrated a functional differentiation between voluminous muscles with short fascicles having small muscle moment arms and muscles with longer fascicles and comparatively smaller physiological cross-sectional area having longer muscle moment arms. The functional implications of these particular configurations were simulated using a simple geometric fascicle strain model that predicts that the rectus femoris and gastrocnemius muscles are more likely to act primarily at their distal joints (knee and ankle, respectively) because they have short fascicles. The data also show that the main hip and knee extensors maintain a very small moment arm throughout the range of joint angles seen in the locomotion of gibbons, which (coupled to voluminous, short-fascicled muscles) might help facilitate rapid joint rotation during powerful movements.

  4. Segmentation of digitized histological sections for quantification of the muscularized vasculature in the mouse hind limb.

    PubMed

    Xu, Yiwen; Pickering, J Geoffrey; Nong, Zengxuan; Ward, Aaron D

    2017-04-01

    Immunohistochemical tissue staining enhances microvasculature characteristics, including the smooth muscle in the medial layer of the vessel walls that is responsible for regulation of blood flow. The vasculature can be imaged in a comprehensive fashion using whole-slide scanning. However, since each such image potentially contains hundreds of small vessels, manual vessel delineation and quantification is not practically feasible. In this work, we present a fully automatic segmentation and vasculature quantification algorithm for whole-slide images. We evaluated its performance on tissue samples drawn from the hind limbs of wild-type mice, stained for smooth muscle using 3,3'-Diaminobenzidine (DAB) immunostain. The algorithm was designed to be robust to vessel fragmentation due to staining irregularity, and artefactual staining of nonvessel objects. Colour deconvolution was used to isolate the DAB stain for detection of vessel wall fragments. Complete vessels were reconstructed from the fragments by joining endpoints of topological skeletons. Automatic measures of vessel density, perimeter, wall area and local wall thickness were taken. The segmentation algorithm was validated against manual measures, resulting in a Dice similarity coefficient of 89%. The relationships observed between these measures were as expected from a biological standpoint, providing further reinforcement of the accuracy of this system. This system provides a fully automated and accurate means of measuring the arteriolar and venular morphology of vascular smooth muscle.

  5. A three-dimensional analysis of the morphological evolution and locomotor behaviour of the carnivoran hind limb

    PubMed Central

    2014-01-01

    Background The shape of the appendicular bones in mammals usually reflects adaptations towards different locomotor abilities. However, other aspects such as body size and phylogeny also play an important role in shaping bone design. We used 3D landmark-based geometric morphometrics to analyse the shape of the hind limb bones (i.e., femur, tibia, and pelvic girdle bones) of living and extinct terrestrial carnivorans (Mammalia, Carnivora) to quantitatively investigate the influence of body size, phylogeny, and locomotor behaviour in shaping the morphology of these bones. We also investigated the main patterns of morphological variation within a phylogenetic context. Results Size and phylogeny strongly influence the shape of the hind limb bones. In contrast, adaptations towards different modes of locomotion seem to have little influence. Principal Components Analysis and the study of phylomorphospaces suggest that the main source of variation in bone shape is a gradient of slenderness-robustness. Conclusion The shape of the hind limb bones is strongly influenced by body size and phylogeny, but not to a similar degree by locomotor behaviour. The slender-robust “morphological bipolarity” found in bone shape variability is probably related to a trade-off between maintaining energetic efficiency and withstanding resistance to stresses. The balance involved in this trade-off impedes the evolution of high phenotypic variability. In fact, both morphological extremes (slender/robust) are adaptive in different selective contexts and lead to a convergence in shape among taxa with extremely different ecologies but with similar biomechanical demands. Strikingly, this “one-to-many mapping” pattern of evolution between morphology and ecology in hind limb bones is in complete contrast to the “many-to-one mapping” pattern found in the evolution of carnivoran skull shape. The results suggest that there are more constraints in the evolution of the shape of the appendicular

  6. Impact of neonatal asphyxia and hind limb immobilization on musculoskeletal tissues and S1 map organization: implications for cerebral palsy.

    PubMed

    Coq, Jacques-Olivier; Strata, Fabrizio; Russier, Michaël; Safadi, Fayez F; Merzenich, Michael M; Byl, Nancy N; Barbe, Mary F

    2008-03-01

    Cerebral palsy (CP) is a complex disorder of locomotion, posture and movements resulting from pre-, peri- or postnatal damage to the developing brain. In a previous study (Strata, F., Coq, J.O., Byl, N.N., Merzenich, M.M., 2004. Comparison between sensorimotor restriction and anoxia on gait and motor cortex organization: implications for a rodent model of cerebral palsy. Neuroscience 129, 141-156.), CP-like movement disorders were more reliably reproduced in rats by hind limb sensorimotor restriction (disuse) during development rather than perinatal asphyxia (PA). To gain new insights into the underpinning mechanisms of CP symptoms we investigated the long-term effects of PA and disuse on the hind limb musculoskeletal histology and topographical organization in the primary somatosensory cortex (S1) of adult rats. Developmental disuse (i.e. hind limb immobilization) associated with PA induced muscle fiber atrophy, extracellular matrix changes in the muscle, and mild to moderate ankle and knee joint degeneration at levels greater than disuse alone. Sensorimotor restricted rats with or without PA exhibited a topographical disorganization of the S1 cortical hind limb representation with abnormally large, multiple and overlapping receptive fields. This disorganization was enhanced when disuse and PA were associated. Altered cortical neuronal properties included increased cortical responsiveness and a decrease in neuronal selectivity to afferent inputs. These data support previous observations that asphyxia per se can generate the substrate for peripheral tissue and brain damage, which are worsened by aberrant sensorimotor experience during maturation, and could explain the disabling movement disorders observed in children with CP.

  7. Osteology and radiographic anatomy of the pelvis and hind limb of healthy ring-tailed lemurs (Lemur catta).

    PubMed

    Makungu, M; Groenewald, H B; du Plessis, W M; Barrows, M; Koeppel, K N

    2014-06-01

    In family Lemuridae, anatomical variations exist. Considering its conservation status (near threatened) and presence of similarities between strepsirrhines and primitive animals, it was thought to be beneficial to describe the gross osteology and radiographic anatomy of the pelvis and hind limb of ring-tailed lemurs (Lemur catta) as a reference for clinical use and species identification. Radiography was performed in 14 captive adult ring-tailed lemurs. The radiographic findings were correlated with bone specimens from two adult animals. Additionally, computed tomography of the hind limbs was performed in one animal. The pelvic bone has a well-developed caudal ventral iliac spine. The patella has a prominent tuberosity on the cranial surface. The first metatarsal bone and digit 1 are markedly stouter than the other metatarsal bones and digits with medial divergence from the rest of the metatarsal bones and digits. Ossicles were seen in the lateral meniscus, inter-phalangeal joint of digit 1 and in the infrapatellar fat pad. Areas of mineral opacity were seen within the external genitalia, which are believed to be the os penis and os clitoris. Variations exist in the normal osteology and radiographic appearance of the pelvis and hind limb of different animal species. The use of only atlases from domestic cats and dogs for interpretative purposes may be misleading.

  8. Effect of recovery mode following hind-limb suspension on soleus muscle composition in the rat

    NASA Technical Reports Server (NTRS)

    McNulty, A. L.; Otto, A. J.; Kasper, C. E.; Thomas, D. P.

    1992-01-01

    The purpose of this study was to compare the effects of two different recovery modes from hind-limb suspension-induced hypodynamia on whole body and muscle (soleus) growth as well as soleus composition and size changes of different fiber types within this same muscle. Following 28 days of tail-suspension, rats were returned to their cages and sedentarily recovered (HS), or were exercised by running on a treadmill 5 days/wk, at progressively increasing workloads (HR) for one month. Sedentary and running control groups of animals (CS, CR) were also evaluated for comparative purposes. The exercise program, which was identical for CR and HR groups, had no effect on body wt., soleus wt., soleus muscle composition or fiber size in CR rats. Atrophied soleus muscle and reduced soleus wt./body wt. ratio (both 60% of control) had returned to control values by day 7 of recovery in both suspended groups despite the fact that whole body wt. gain was significantly reduced (p less than 0.05) in HR as compared to HS rats. Atrophied soleus Type I fiber mean cross-sectional area in both HR and HS groups demonstrated similar and significant (p less than 0.01) increases during recovery. Increases in Type IIa and IIc fiber area during this same period were significant only in the HR group. While the percentage area of muscle composed of Type I fibers increased in both hypodynamic groups during recovery, the reduction in area percentage of muscle made up of Type IIa fibers was again only significant in the HR group.(ABSTRACT TRUNCATED AT 250 WORDS).

  9. Muscle growth and fiber type composition in hind limb muscles during postnatal development in pigs.

    PubMed

    Wank, Veit; Fischer, Martin S; Walter, Bernd; Bauer, Reinhard

    2006-01-01

    Rapid postnatal development in pigs is reflected by differentiation in skeletal muscle. This process depends on muscle function and demands, but a comprehensive overview of individual developmental characteristics of quickly growing leg muscles in pigs is still missing. This study focused on the development of 10 hind limb muscles in pigs. To determine these changes in mass, fiber type patterns and fiber diameters were analyzed 0, 2, 4, 7, 14, 28, 42, 56 and 400 days after birth. Generally, the proportion of slow fibers increased from birth to 8 weeks. Thereafter, only minor changes in muscle fiber type composition were observed. The majority of the muscles contained less then 10% slow-twitch fibers at birth, increasing to between 12 (Musculus vastus lateralis) and 38% (M. gastrocnemius medialis) in adult pigs. By contrast, postural muscles already had 20-30% slow fibers at birth, and this contribution increased up to 65% in adults (i.e. M. vastus intermedius). From birth to the 2nd week, only in slow fibers could activity of oxidative enzymes be detected. A differentiation of fast-twitch fibers into subtypes with high (comparable to type IIA) and low oxidative metabolism (equivalent to type IIB) occurred between the 2nd and 4th week of life. The ratio between type II fibers with high and low oxidative enzyme activity did not change markedly through development in any muscle, although there was a trend towards an increasing proportion of type IIA fibers in the soleus. In the majority of the muscles investigated, the fast-twitch fibers with low oxidative metabolism (IIB) obtained the largest cross-sectional area. In contrast, at birth no remarkable differences in the diameter of fast and slow fibers were found. The rapid increase in muscle mass compared to body mass reflects the high performance in meat production of the cross pig investigated.

  10. A Modified Heterotopic Swine Hind Limb Transplant Model for Translational Vascularized Composite Allotransplantation (VCA) Research

    PubMed Central

    Ibrahim, Zuhaib; Cooney, Damon S.; Shores, Jaimie T.; Sacks, Justin M.; Wimmers, Eric G.; Bonawitz, Steven C.; Gordon, Chad; Ruben, Dawn; Schneeberger, Stefan; Lee, W. P. Andrew; Brandacher, Gerald

    2013-01-01

    Vascularized Composite Allotransplantation (VCA) such as hand and face transplants represent a viable treatment option for complex musculoskeletal trauma and devastating tissue loss. Despite favorable and highly encouraging early and intermediate functional outcomes, rejection of the highly immunogenic skin component of a VCA and potential adverse effects of chronic multi-drug immunosuppression continue to hamper widespread clinical application of VCA. Therefore, research in this novel field needs to focus on translational studies related to unique immunologic features of VCA and to develop novel immunomodulatory strategies for immunomodulation and tolerance induction following VCA without the need for long term immunosuppression. This article describes a reliable and reproducible translational large animal model of VCA that is comprised of an osteomyocutaneous flap in a MHC-defined swine heterotopic hind limb allotransplantation. Briefly, a well-vascularized skin paddle is identified in the anteromedial thigh region using near infrared laser angiography. The underlying muscles, knee joint, distal femur, and proximal tibia are harvested on a femoral vascular pedicle. This allograft can be considered both a VCA and a vascularized bone marrow transplant with its unique immune privileged features. The graft is transplanted to a subcutaneous abdominal pocket in the recipient animal with a skin component exteriorized to the dorsolateral region for immune monitoring. Three surgical teams work simultaneously in a well-coordinated manner to reduce anesthesia and ischemia times, thereby improving efficiency of this model and reducing potential confounders in experimental protocols. This model serves as the groundwork for future therapeutic strategies aimed at reducing and potentially eliminating the need for chronic multi-drug immunosuppression in VCA. PMID:24145603

  11. A three-dimensional musculoskeletal model of the chimpanzee (Pan troglodytes) pelvis and hind limb.

    PubMed

    O'Neill, Matthew C; Lee, Leng-Feng; Larson, Susan G; Demes, Brigitte; Stern, Jack T; Umberger, Brian R

    2013-10-01

    Musculoskeletal models have become important tools for studying a range of muscle-driven movements. However, most work has been in modern humans, with few applications in other species. Chimpanzees are facultative bipeds and our closest living relatives, and have provided numerous important insights into our own evolution. A chimpanzee musculoskeletal model would allow integration across a wide range of laboratory-based experimental data, providing new insights into the determinants of their locomotor performance capabilities, as well as the origins and evolution of human bipedalism. Here, we described a detailed three-dimensional (3D) musculoskeletal model of the chimpanzee pelvis and hind limb. The model includes geometric representations of bones and joints, as well as 35 muscle-tendon units that were represented using 44 Hill-type muscle models. Muscle architecture data, such as muscle masses, fascicle lengths and pennation angles, were drawn from literature sources. The model permits calculation of 3D muscle moment arms, muscle-tendon lengths and isometric muscle forces over a wide range of joint positions. Muscle-tendon moment arms predicted by the model were generally in good agreement with tendon-excursion estimates from cadaveric specimens. Sensitivity analyses provided information on the parameters that model predictions are most and least sensitive to, which offers important context for interpreting future results obtained with the model. Comparisons with a similar human musculoskeletal model indicate that chimpanzees are better suited for force production over a larger range of joint positions than humans. This study represents an important step in understanding the integrated function of the neuromusculoskeletal systems in chimpanzee locomotion.

  12. Dynamics of goat distal hind limb muscle–tendon function in response to locomotor grade

    PubMed Central

    McGuigan, M. Polly; Yoo, Edwin; Lee, David V.; Biewener, Andrew A.

    2009-01-01

    Summary The functional roles of the lateral gastrocnemius (LG), medial gastrocnemius (MG) and superficial digital flexor (SDF) muscle–tendon units (MTUs) in domestic goats (N=6) were studied as a function of locomotor grade, testing the hypothesis that changes in distal limb muscle work would reflect changes in mechanical work requirements while goats walked or trotted on the level, 15 deg. decline and 15 deg. incline. As steep terrain-adapted animals, changes in muscle work output are expected to be particularly important for goats. In vivo muscle–tendon forces, fascicle length changes and muscle activation were recorded via tendon force buckles, sonomicrometry and electromyography to evaluate the work performance and elastic energy recovery of the three distal MTUs. These recordings confirmed that fascicle strain and force within goat distal hind limb muscles are adjusted in response to changes in mechanical work demand associated with locomotor grade. In general, muscle work was modulated most consistently by changes in fascicle strain, with increased net shortening (P<0.001) observed as goats switched from decline to level to incline locomotion. Peak muscle stresses increased as goats increased speed from a walk to a trot within each grade condition (P<0.05), and also increased significantly with grade (P<0.05 to P<0.01). Due to the increase in net fascicle shortening and muscle force, net muscle work per cycle also increased significantly (P<0.05 to P<0.005) as goats switched from decline to level to incline conditions (LG work: 20 mJ to 56 mJ to 209 mJ; MG work: –7 mJ to 34 mJ to 179 mJ; SDF work: –42 mJ to 14 mJ to 71 mJ, at a 2.5 ms–1 trot). Although muscle work was modulated in response to changes in grade, the amount of work produced by these three distal pennate muscles was small (being <3%) in comparison with the change in mechanical energy required of the limb as a whole. Elastic energy recovery in the SDF and gastrocnemius (GA) tendons was

  13. Exploring the Role of TRPV and CGRP in Adenosine Preconditioning and Remote Hind Limb Preconditioning-Induced Cardioprotection in Rats.

    PubMed

    Singh, Amritpal; Randhawa, Puneet Kaur; Bali, Anjana; Singh, Nirmal; Jaggi, Amteshwar Singh

    2017-02-14

    The cardioprotective effects of remote hind limb preconditioning (RIPC) are well known, but mechanisms by which protection occurs still remain to be explored. Therefore, the present study was designed to investigate the role of TRPV and CGRP in adenosine and remote preconditioning-induced cardioprotection, using sumatriptan, a CGRP release inhibitor and ruthenium red, a TRPV inhibitor, in rats. For remote preconditioning, a pressure cuff was tied around the hind limb of the rat and was inflated with air up to 150 mmHg to produce ischemia in the hind limb and during reperfusion pressure was released. Four cycles of ischemia and reperfusion, each consisting of 5 min of inflation and 5 min of deflation of pressure cuff were used to produce remote limb preconditioning. An ex vivo Langendorff's isolated rat heart model was used to induce ischemia reperfusion injury by 30 min of global ischemia followed by 120 min of reperfusion. RIPC demonstrated a significant decrease in ischemia reperfusion-induced significant myocardial injury in terms of increase in LDH, CK, infarct size and decrease in LVDP, +dp/dtmax and -dp/dtmin. Moreover, pharmacological preconditioning with adenosine produced cardioprotective effects in a similar manner to RIPC. Pretreatment with sumatriptan, a CGRP release blocker, abolished RIPC and adenosine preconditioning-induced cardioprotective effects. Administration of ruthenium red, a TRPV inhibitor, also abolished adenosine preconditioning-induced cardioprotection. It may be proposed that the cardioprotective effects of adenosine and remote preconditioning are possibly mediated through activation of a TRPV channels and consequent, release of CGRP.

  14. In Vivo Detection of Macrophage Recruitment in Hind-Limb Ischemia Using a Targeted Near-Infrared Fluorophore

    PubMed Central

    Yoo, Jung Sun; Das, Raj Kumar; Jow, Zhi Yen; Chang, Young-Tae

    2014-01-01

    Macrophages are an essential component of the immune system and have protective and pathogenic functions in various diseases. Imaging of macrophages in vivo could furnish new tools to advance evaluation of disease and therapies. Critical limb ischemia is a disease in which macrophages have considerable pathogenic roles, and are potential targets for cell-based immunotherapy. We sought to develop a new near-infrared fluorescence (NIRF) imaging probe to target macrophages specifically in vivo in various pathological states, including hind-limb ischemia. We rapidly screened the photostable cyanine-based NIRF library against different blood cell lines. The identified monocyte/macrophage-selective hit was tested in vitro in live-cell labeling assay. Non-invasive NIRF imaging was performed with murine models of paw inflammation by lipopolysaccharide challenge and hind-limb ischemia with femoral artery ligation. in vivo macrophage targeting was further evaluated using intravital microscopy with Csf1r-EGFP transgenic mice and immunofluorescent staining with macrophage-specific markers. We discovered MF800, a Macrophage-specific near-infrared Fluorophore, which showed selective live-cell imaging performance in a panel of cell lines and primary human blood samples. MF800 outperforms the clinically-available NIRF contrast agent ICG for in vivo specificity in paw inflammation and hind-limb ischemia models. We observed a marked overlap of MF800-labeled cells and EGFP-expressing macrophages in intravital imaging of Csf1r-EGFP transgenic mice. In the histologic analysis, MF800-positive cells also expressed the macrophage markers CD68 and CD169. NIRF imaging showcased the potential of using MF800 to understand macrophage behavior in vivo, characterize macrophage-associated diseases, and may help in assessing therapeutic responses in the clinic. PMID:25072508

  15. The response of the hind-limb vascular bed of the rabbit to sympathetic stimulation and its modification by pregnancy.

    PubMed Central

    Humphreys, P W; Joels, N

    1982-01-01

    1. Pressure-flow relationships in the hind limb, perfused with blood at a series of constant flows, have been compared in primigravid and virgin rabbits following section of the lumbar sympathetic chain. 2. In the absence of sympathetic stimulation perfusion pressure was lower (P less than 0.05) in the pregnant rabbits at all levels of flow to the leg. 3. It is concluded that pregnancy leads to a reduction in the vascular resistance of the acutely sympathectomized hind limb. 4. The pressure-flow curves of hind limbs from pregnant and non-pregnant rabbits in which the cutaneous circulation had been excluded by skinning the leg and ligating the ankle were also compared. Again, perfusion pressure at each flow level was lower in the limbs from the pregnant animals (P less than 0.05). 5. The sympathetic supply was stimulated at frequencies of 0.3, 1, 3, 7, 15 and 30 Hz. Irrespective of whether the cutaneous circulation was excluded, the pressure-flow curves for the hind limbs of pregnant and non-pregnant rabbits were different at the lower frequencies. As stimulus frequency rose this difference became smaller, and at a stimulus frequency of 7-15 Hz or more there was little difference in the position of the curves in pregnant and non-pregnant rabbits. 6. Examination of the pressure-flow curves suggests that when, as in these experiments, flow is held constant, the ability of sympathetic stimulation to increase the resistance to blood flow is reduced in pregnancy. However, if these pressure-flow curves are used to predict the change of flow that would occur at a constant perfusion pressure, the response to sympathetic stimulation appears to be greater in pregnancy. 7. Further analysis of the findings, based on certain assumptions, suggests that differences between the pressure-flow curves of pregnant and non-pregnant animals during sympathetic stimulation are due in the main to either a differing size of the unstimulated vascular beds or a differing compliance of their

  16. Fucoidan improves bioactivity and vasculogenic potential of mesenchymal stem cells in murine hind limb ischemia associated with chronic kidney disease.

    PubMed

    Lee, Jun Hee; Ryu, Jung Min; Han, Yong-Seok; Zia, Mohammad Farid; Kwon, Hyog Young; Noh, Hyunjin; Han, Ho Jae; Lee, Sang Hun

    2016-08-01

    Chronic kidney disease (CKD) is a significant risk factor for cardiovascular and peripheral vascular disease. Although mesenchymal stem cell (MSC)-based therapy is a promising strategy for treatment of ischemic diseases associated with CKD, the associated pathophysiological conditions lead to low survival and proliferation of transplanted MSCs. To address these limitations, we investigated the effects of fucoidan, a sulfated polysaccharide, on the bioactivity of adipose tissue-derived MSCs and the potential of fucoidan-treated MSCs to improve neovascularization in ischemic tissues of CKD mice. Treatment of MSCs with fucoidan increased their proliferative potential and the expression of cell cycle-associated proteins, such as cyclin E, cyclin dependent kinase (CDK) 2, cyclin D1, and CDK4, via focal adhesion kinase and the phosphatidylinositol-4,5-bisphosphate 3-kinase-Akt axis. Moreover, fucoidan enhanced the immunomodulatory activity of MSCs through the ERK-IDO-1 signal cascade. Fucoidan was found to augment the proliferation, incorporation, and endothelial differentiation of transplanted MSCs at ischemic sites in CKD mice hind limbs. In addition, transplantation of fucoidan-treated MSCs enhanced the ratio of blood flow and limb salvage in CKD mice with hind limb ischemia. To our knowledge, our findings are the first to reveal that fucoidan enhances the bioactivity of MSCs and improves their neovascularization in ischemic injured tissues of CKD. In conclusion, fucoidan-treated MSCs may provide an important pathway toward therapeutic neovascularization in patients with CKD.

  17. Increased androgenic sensitivity in the hind limb muscular system marks the evolution of a derived gestural display

    PubMed Central

    Mangiamele, Lisa A.; Fuxjager, Matthew J.; Schuppe, Eric R.; Taylor, Rebecca S.; Hödl, Walter; Preininger, Doris

    2016-01-01

    Physical gestures are prominent features of many species’ multimodal displays, yet how evolution incorporates body and leg movements into animal signaling repertoires is unclear. Androgenic hormones modulate the production of reproductive signals and sexual motor skills in many vertebrates; therefore, one possibility is that selection for physical signals drives the evolution of androgenic sensitivity in select neuromotor pathways. We examined this issue in the Bornean rock frog (Staurois parvus, family: Ranidae). Males court females and compete with rivals by performing both vocalizations and hind limb gestural signals, called “foot flags.” Foot flagging is a derived display that emerged in the ranids after vocal signaling. Here, we show that administration of testosterone (T) increases foot flagging behavior under seminatural conditions. Moreover, using quantitative PCR, we also find that adult male S. parvus maintain a unique androgenic phenotype, in which androgen receptor (AR) in the hind limb musculature is expressed at levels ∼10× greater than in two other anuran species, which do not produce foot flags (Rana pipiens and Xenopus laevis). Finally, because males of all three of these species solicit mates with calls, we accordingly detect no differences in AR expression in the vocal apparatus (larynx) among taxa. The results show that foot flagging is an androgen-dependent gestural signal, and its emergence is associated with increased androgenic sensitivity within the hind limb musculature. Selection for this novel gestural signal may therefore drive the evolution of increased AR expression in key muscles that control signal production to support adaptive motor performance. PMID:27143723

  18. Activation patterns of embryonic chick hind limb muscles recorded in ovo and in an isolated spinal cord preparation.

    PubMed

    Landmesser, L T; O'Donovan, M J

    1984-02-01

    Muscle activation patterns of embryonic chick hind limb muscles were determined from electromyographic (e.m.g.) recordings in an isolated spinal cord/hind limb preparation of stage 34-36 embryos, and were compared with in ovo e.m.g. activity from similarly staged embryos. Muscle activity in ovo consisted of periodically recurring sequences of bursts during which antagonistic muscles often alternated and synergistic muscles were co-active, as compatible with their mature function. However, more variable behaviour was also observed. Burst sequences in ovo were often initiated by a short-duration, high-amplitude discharge that occurred synchronously in all muscles studied, and which was followed by a period of electrical silence that was longest in the flexor muscles. This type of activity has not been described previously in mature animals. In ovo movement sequences were generally initiated by extensor activity which progressively declined in duration and intensity throughout the sequence, while flexor activity progressively intensified. The onset of activity in extensor muscles was accompanied by an abrupt decrease in flexor activity, whereas the converse was not observed. Spontaneous movement sequences also occurred when the spinal cord and hind limb were isolated and maintained in oxygenated Tyrode solution for several hours. Deafferentation experiments indicated that the motor pattern in this preparation was generated centrally by circuits within the spinal cord. Activity from the isolated cord was less variable than that occurring in ovo, consisting of sequences of highly regular recurring bursts. Each burst began with a brief high-amplitude discharge that occurred synchronously in all muscles and which was similar to that observed in ovo. This was followed by a silent period, which was longest in the flexors, and then by a more prolonged burst. Although its behaviour differs from that in ovo in some respects, it is concluded that the isolated cord maintained in

  19. Activation patterns of embryonic chick hind limb muscles recorded in ovo and in an isolated spinal cord preparation.

    PubMed Central

    Landmesser, L T; O'Donovan, M J

    1984-01-01

    Muscle activation patterns of embryonic chick hind limb muscles were determined from electromyographic (e.m.g.) recordings in an isolated spinal cord/hind limb preparation of stage 34-36 embryos, and were compared with in ovo e.m.g. activity from similarly staged embryos. Muscle activity in ovo consisted of periodically recurring sequences of bursts during which antagonistic muscles often alternated and synergistic muscles were co-active, as compatible with their mature function. However, more variable behaviour was also observed. Burst sequences in ovo were often initiated by a short-duration, high-amplitude discharge that occurred synchronously in all muscles studied, and which was followed by a period of electrical silence that was longest in the flexor muscles. This type of activity has not been described previously in mature animals. In ovo movement sequences were generally initiated by extensor activity which progressively declined in duration and intensity throughout the sequence, while flexor activity progressively intensified. The onset of activity in extensor muscles was accompanied by an abrupt decrease in flexor activity, whereas the converse was not observed. Spontaneous movement sequences also occurred when the spinal cord and hind limb were isolated and maintained in oxygenated Tyrode solution for several hours. Deafferentation experiments indicated that the motor pattern in this preparation was generated centrally by circuits within the spinal cord. Activity from the isolated cord was less variable than that occurring in ovo, consisting of sequences of highly regular recurring bursts. Each burst began with a brief high-amplitude discharge that occurred synchronously in all muscles and which was similar to that observed in ovo. This was followed by a silent period, which was longest in the flexors, and then by a more prolonged burst. Although its behaviour differs from that in ovo in some respects, it is concluded that the isolated cord maintained in

  20. Curcumin and dexmedetomidine prevents oxidative stress and renal injury in hind limb ischemia/reperfusion injury in a rat model.

    PubMed

    Karahan, M A; Yalcin, S; Aydogan, H; Büyükfirat, E; Kücük, A; Kocarslan, S; Yüce, H H; Taskın, A; Aksoy, N

    2016-06-01

    Curcumin and dexmedetomidine have been shown to have protective effects in ischemia-reperfusion injury on various organs. However, their protective effects on kidney tissue against ischemia-reperfusion injury remain unclear. We aimed to determine whether curcumin or dexmedetomidine prevents renal tissue from injury that was induced by hind limb ischemia-reperfusion in rats. Fifty rats were divided into five groups: sham, control, curcumin (CUR) group (200 mg/kg curcumin, n = 10), dexmedetomidine (DEX) group (25 μg/kg dexmedetomidine, n = 10), and curcumin-dexmedetomidine (CUR-DEX) group (200 mg/kg curcumin and 25 μg/kg dexmedetomidine). Curcumin and dexmedetomidine were administered intraperitoneally immediately after the end of 4 h ischemia, just 5 min before reperfusion. The extremity re-perfused for 2 h and then blood samples were taken and total antioxidant capacity (TAC), total oxidative status (TOS) levels, and oxidative stress index (OSI) were measured, and renal tissue samples were histopathologically examined. The TAC activity levels in blood samples were significantly lower in the control than the other groups (p < 0.01 for all comparisons). The TOS activity levels in blood samples were significantly higher in Control group and than the other groups (p <  0.01 for all comparison). The OSI were found to be significantly increased in the control group compared to others groups (p < 0.001 for all comparisons). Histopathological examination revealed less severe lesions in the sham, CUR, DEX, and CUR-DEX groups, compared with the control group (p < 0.01). Rat hind limb ischemia-reperfusion causes histopathological changes in the kidneys. Curcumin and dexmedetomidine administered intraperitoneally was effective in reducing oxidative stress and renal histopathologic injury in an acute hind limb I/R rat model.

  1. Morphology of the pelvis and hind limb of the red panda (Ailurus fulgens) evidenced by gross osteology, radiography and computed tomography.

    PubMed

    Makungu, M; du Plessis, W M; Groenewald, H B; Barrows, M; Koeppel, K N

    2015-12-01

    The red panda (Ailurus fulgens) is a quadrupedal arboreal animal primarily distributed in the Himalayas and southern China. It is a species commonly kept in zoological collections. This study was carried out to describe the morphology of the pelvis and hind limb of the red panda evidenced by gross osteology, radiography and computed tomography as a reference for clinical use and identification of skeletons. Radiography of the pelvis and right hind limb was performed in nine and seven animals, respectively. Radiographic findings were correlated with bone specimens from three adult animals. Computed tomography of the torso and hind limb was performed in one animal. The pelvic bone had a wide ventromedial surface of the ilium. The trochlea of the femur was wide and shallow. The patella was similar to that seen in feline species. The medial fabella was not seen radiographically in any animal. The cochlea grooves of the tibia were shallow with a poorly defined intermediate ridge. The trochlea of the talus was shallow and presented with an almost flattened medial ridge. The tarsal sesamoid bone was always present. The lateral process of the base of the fifth metatarsal (MT) bone was directed laterally. The MT bones were widely spaced. The morphology of the pelvis and hind limb of the red panda indicated flexibility of the pelvis and hind limb joints as an adaptation to an arboreal quadrupedal lifestyle.

  2. Dynamic imaging of allogeneic adipose-derived regenerative cells transplanted in ischemic hind limb of apolipoprotein E mouse model

    PubMed Central

    Zheng, Yi; Qin, Jinbao; Wang, Xin; Peng, Zhiyou; Hou, Peiyong; Lu, Xinwu

    2017-01-01

    Background Transplantation of allogeneic adipose-derived regenerative cells (ADRCs) is a promising treatment modality for severe ischemic diseases. However, minimal information is available on the in vivo effects, fate, and migration of ADRCs, as well as the mechanisms of their therapeutic angiogenesis. Materials and methods In this study, green fluorescent protein-expressing ADRCs (GFP-ADRCs) were obtained, labeled with acetylated 3-aminopropyltrimethoxysilane (APTS)-coated iron oxide nanoparticles (APTS NPs), and injected into an old apolipoprotein E knockout (ApoE-KO) mouse model with hind limb ischemia. Then, 3.0 T magnetic resonance imaging (MRI) was performed to dynamically trace the role of ADRCs targeting hind limb ischemia in the ApoE-KO mice model. Results Labeled cells were visualized as large hypointense spots in ischemic muscles by serial 3.0 T MRI scans during a 4-week follow-up. The presence of labeled GFP-ADRCs was confirmed by Prussian blue staining and fluorescence microscopy on postmortem specimens. Conclusion This study showed that allogeneic ADRCs offer great potential application for therapeutic angiogenesis in severe ischemic disease based on the efficacy and feasibility of ADRC transplantation and on the available amounts of tissue. PMID:28053524

  3. p66(ShcA) and oxidative stress modulate myogenic differentiation and skeletal muscle regeneration after hind limb ischemia.

    PubMed

    Zaccagnini, Germana; Martelli, Fabio; Magenta, Alessandra; Cencioni, Chiara; Fasanaro, Pasquale; Nicoletti, Carmine; Biglioli, Paolo; Pelicci, Pier Giuseppe; Capogrossi, Maurizio C

    2007-10-26

    Oxidative stress plays a pivotal role in ischemic injury, and p66(ShcA)ko mice exhibit both lower oxidative stress and decreased tissue damage following hind limb ischemia. Thus, it was investigated whether tissue regeneration following acute hind limb ischemia was altered in p66(ShcA)ko mice. Upon femoral artery dissection, muscle regeneration started earlier and was completed faster than in wild-type (WT) control. Moreover, faster regeneration was associated with decreased oxidative stress. Unlike ischemia, cardiotoxin injury induced similar skeletal muscle damage in both genotypes. However, p66(ShcA)ko mice regenerated faster, in agreement with the regenerative advantage upon ischemia. Since no difference between p66(ShcA)wt and knock-out (ko) mice was found in blood perfusion recovery after ischemia, satellite cells (SCs), a resident population of myogenic progenitors, were examined. Similar SCs numbers were present in WT and ko mice. However, in vitro cultured p66(ShcA)ko SCs displayed lower oxidative stress levels and higher proliferation rate and differentiated faster than WT. Furthermore, when exposed to sublethal H(2)O(2) doses, p66(ShcA)ko SCs were resistant to H(2)O(2)-induced inhibition of differentiation. Finally, myogenic conversion induced by MyoD overexpression was more efficient in p66(ShcA)ko fibroblasts compared with WT. The present work demonstrates that oxidative stress and p66(ShcA) play a crucial role in the regenerative pathways activated by acute ischemia.

  4. AB296. SPR-23 Aberrant bladder reflexes can drive hind limb locomotor activity following complete suprasacral spinal cord injury

    PubMed Central

    Inouye, Brian M.; Brooks, Jillene M.; Degoski, Danielle J.; Hughes, Francis M.; Purves, J. Todd; Fraser, Matthew O.

    2016-01-01

    Objective Many rats with chronic suprasacral spinal cord injury (SCI) demonstrate hind limb locomotor activity (HLLA) in response to external crede or high pressure contractions during cystometry. We propose that this aberrant, pressure-driven bladder reflex pathway may be harnessed to facilitate walking in SCI patients. As a first step in exploring this possibility, we examined the relationship between intravesical pressure (IVP) and HLLA in chronic suprasacral SCI rats. Methods Female rats (4 weeks post-SCI at T9-10, n=16) were anesthetized with isoflurane and fitted with transvesical catheters and right quadriceps EMG electrodes to monitor bladder and hind limb locomotor activities, respectively. The animals were mounted in Ballman restraint cages to which they had been previously acclimated. The catheter was connected to a pressure transducer, an infusion pump, and a saline-filled reservoir mounted on a metered vertical pole (pressure clamp). After 30 min of recovery from anesthesia, the bladder was filled at 0.1 mL/min with saline to verify bladder-to-bladder reflex activity for 30 min. IVP was then increased in an interrupted stepwise fashion from 0–120 cmH2O at 10 cmH2O increments. Each step consisted of five minutes: 3 minutes at the new pressure followed by 2 minutes at 0 cmH2O. IVP and the number of HLLA events (as defined by rhythmic EMG discharges of 3–10 cycles/event) were recorded for each pressure step. This process was repeated for two more trials for each rat to assess the durability of the reflex. Data were analyzed using ANOVA with repeated measures both within and across pressure escalation trials. P<0.05 was considered significant. Results ANOVA revealed that locomotor events increased with increasing IVP and decreased with the number of escalation trials (P<0.0001 for both effects). The increase in the number of locomotor events with increasing IVP appeared to plateau at ~50–60 cmH2O (P<0.05 for all). The average of the maximal number of

  5. Accuracy and precision of hind limb foot contact timings of horses determined using a pelvis-mounted inertial measurement unit.

    PubMed

    Starke, Sandra D; Witte, Thomas H; May, Stephen A; Pfau, Thilo

    2012-05-11

    Gait analysis using small sensor units is becoming increasingly popular in the clinical context. In order to segment continuous movement from a defined point of the stride cycle, knowledge about footfall timings is essential. We evaluated the accuracy and precision of foot contact timings of a defined limb determined using an inertial sensor mounted on the pelvis of ten horses during walk and trot at different speeds and in different directions. Foot contact was estimated from vertical velocity events occurring before maximum sensor roll towards the contralateral limb. Foot contact timings matched data from a synchronised hoof mounted accelerometer well when velocity minimum was used for walk (mean (SD) difference of 15 (18)ms across horses) and velocity zero-crossing for trot (mean (SD) difference from -4 (14) to 12 (7)ms depending on the condition). The stride segmentation method also remained robust when applied to movement data of hind limb lame horses. In future, this method may find application in segmenting overground sensor data of various species.

  6. Vasomotor responses in the hind limbs of foetal and new-born lambs to asphyxia and aortic chemoreceptor stimulation

    PubMed Central

    Dawes, G. S.; Lewis, B. V.; Milligan, J. E.; Roach, Margot R.; Talner, N. S.

    1968-01-01

    1. Hind limb blood flow was measured in lambs of from 91 days gestation (delivered by Caesarean section) to 1 month after birth (term is about 147 days), under chloralose anaesthesia. Vascular resistance/100 g wet wt. increased progressively with age. There was reflex femoral vascular tone from the earliest age studied, as shown by vasodilatation on cutting the sciatic nerve. 2. On asphyxia by cord occlusion reflex femoral vasoconstriction began earlier and was somewhat greater in older foetal lambs. At all ages, and after denervation of the hind limb, there was vasodilatation after local ischaemia, and a vasoconstriction of delayed onset during asphyxia attributed to release of noradrenaline into the circulation. The vasoconstrictor effect of noradrenaline in immature lambs was at least as great as at term or in the new-born. 3. Injections of minimal effective doses of cyanide were used to localize possible chemoreceptor sites in foetal lambs. Injection into the left atrium caused a rise of arterial pressure, femoral vasoconstriction and a complex change in heart rate (usually bradycardia) but rarely any respiratory movement. After atropine, cyanide caused a large tachycardia. All responses were much reduced or abolished by cervical vagotomy. 4. Injection of the same doses of cyanide into a jugular vein, the right ventricle, pulmonary or common carotid arteries of foetal lambs caused negligible cardiovascular or respiratory effects, whereas injection into the carotids of new-born lambs caused a profound hyperpnoea. 5. It is concluded that the aortic chemoreceptors are active in the foetus, are supplied from the left heart, and that they probably represent the primary defence in blood gas homeostasis by their effects on the circulation. PMID:4295757

  7. Arboreal Day Geckos (Phelsuma madagascariensis) Differentially Modulate Fore- and Hind Limb Kinematics in Response to Changes in Habitat Structure

    PubMed Central

    Zhuang, Mingna V.; Higham, Timothy E.

    2016-01-01

    By using adhesion, geckos can move through incredibly challenging habitats. However, continually changing terrain may necessitate modulation of the adhesive apparatus in order to maximize its effectiveness over a range of challenges. Behaviorally modulating how the adhesive system is applied can occur by altering the alignment of the foot relative to the long axis of the body and/or the angles between the digits (interdigital angle). Given the directionality of the adhesive system, geckos likely vary the application of the system via these mechanisms as they run. We quantified 3D movements (using high-speed video) of the day gecko, Phelsuma madagascariensis, running on a range of ecologically relevant inclines (0°, 45°, 90°) and perch diameters (1.5 cm, 10 cm and broad). We measured the instantaneous sum of interdigital angles and foot alignment relative to the body, as well as other kinematic variables, throughout each stride and across treatments. Modulation of foot alignment at 45° and 90° was similar between the forelimb and hind limb, but differed at 0°, suggesting that P. madagascariensis is able to exert an adhesive force using multiple strategies. Both the sum of interdigital angles and alignment in the fore- and hind foot were modulated. Differences in modulation between the limbs are likely related to the underlying morphology. The modulation of interdigital angle and foot alignment suggests that aspects other than the mechanism of adhesion, such as joint morphology, are important for arboreal movement in geckos. Our study of foot usage in arboreal locomotion reveals patterns that may be widespread across pad-bearing lizards. In addition to understanding the constraints exerted by the adhesive apparatus, we highlight how biomechanical traits may respond to the evolution of novel adaptations and morphologies. PMID:27145027

  8. Vasomotor responses in the hind limbs of foetal and new-born lambs to asphyxia and aortic chemoreceptor stimulation.

    PubMed

    Dawes, G S; Lewis, B V; Milligan, J E; Roach, M R; Talner, N S

    1968-03-01

    1. Hind limb blood flow was measured in lambs of from 91 days gestation (delivered by Caesarean section) to 1 month after birth (term is about 147 days), under chloralose anaesthesia. Vascular resistance/100 g wet wt. increased progressively with age. There was reflex femoral vascular tone from the earliest age studied, as shown by vasodilatation on cutting the sciatic nerve.2. On asphyxia by cord occlusion reflex femoral vasoconstriction began earlier and was somewhat greater in older foetal lambs. At all ages, and after denervation of the hind limb, there was vasodilatation after local ischaemia, and a vasoconstriction of delayed onset during asphyxia attributed to release of noradrenaline into the circulation. The vasoconstrictor effect of noradrenaline in immature lambs was at least as great as at term or in the new-born.3. Injections of minimal effective doses of cyanide were used to localize possible chemoreceptor sites in foetal lambs. Injection into the left atrium caused a rise of arterial pressure, femoral vasoconstriction and a complex change in heart rate (usually bradycardia) but rarely any respiratory movement. After atropine, cyanide caused a large tachycardia. All responses were much reduced or abolished by cervical vagotomy.4. Injection of the same doses of cyanide into a jugular vein, the right ventricle, pulmonary or common carotid arteries of foetal lambs caused negligible cardiovascular or respiratory effects, whereas injection into the carotids of new-born lambs caused a profound hyperpnoea.5. It is concluded that the aortic chemoreceptors are active in the foetus, are supplied from the left heart, and that they probably represent the primary defence in blood gas homeostasis by their effects on the circulation.

  9. TLR4 Accessory Molecule RP105 (CD180) Regulates Monocyte-Driven Arteriogenesis in a Murine Hind Limb Ischemia Model

    PubMed Central

    Bastiaansen, Antonius J. N. M.; Karper, Jacco C.; Wezel, Anouk; de Boer, Hetty C.; Welten, Sabine M. J.; de Jong, Rob C. M.; Peters, Erna A. B.; de Vries, Margreet R.; van Oeveren-Rietdijk, Annemarie M.; van Zonneveld, Anton Jan; Hamming, Jaap F.

    2014-01-01

    Aims We investigated the role of the TLR4-accessory molecule RP105 (CD180) in post-ischemic neovascularization, i.e. arteriogenesis and angiogenesis. TLR4-mediated activation of pro-inflammatory Ly6Chi monocytes is crucial for effective neovascularization. Immunohistochemical analyses revealed that RP105+ monocytes are present in the perivascular space of remodeling collateral arterioles. As RP105 inhibits TLR4 signaling, we hypothesized that RP105 deficiency would lead to an unrestrained TLR4-mediated inflammatory response and hence to enhanced blood flow recovery after ischemia. Methods and Results RP105−/− and wild type (WT) mice were subjected to hind limb ischemia and blood flow recovery was followed by Laser Doppler Perfusion Imaging. Surprisingly, we found that blood flow recovery was severely impaired in RP105−/− mice. Immunohistochemistry showed that arteriogenesis was reduced in these mice compared to the WT. However, both in vivo and ex vivo analyses showed that circulatory pro-arteriogenic Ly6Chi monocytes were more readily activated in RP105−/− mice. FACS analyses showed that Ly6Chi monocytes became activated and migrated to the affected muscle tissues in WT mice following induction of hind limb ischemia. Although Ly6Chi monocytes were readily activated in RP105−/− mice, migration into the ischemic tissues was hampered and instead, Ly6Chi monocytes accumulated in their storage compartments, bone marrow and spleen, in RP105−/− mice. Conclusions RP105 deficiency results in an unrestrained inflammatory response and monocyte over-activation, most likely due to the lack of TLR4 regulation. Inappropriate, premature systemic activation of pro-inflammatory Ly6Chi monocytes results in reduced infiltration of Ly6Chi monocytes in ischemic tissues and in impaired blood flow recovery. PMID:24945347

  10. A system identification analysis of neural adaptation dynamics and nonlinear responses in the local reflex control of locust hind limbs.

    PubMed

    Dewhirst, Oliver P; Angarita-Jaimes, Natalia; Simpson, David M; Allen, Robert; Newland, Philip L

    2013-02-01

    Nonlinear type system identification models coupled with white noise stimulation provide an experimentally convenient and quick way to investigate the often complex and nonlinear interactions between the mechanical and neural elements of reflex limb control systems. Previous steady state analysis has allowed the neurons in such systems to be categorised by their sensitivity to position, velocity or acceleration (dynamics) and has improved our understanding of network function. These neurons, however, are known to adapt their output amplitude or spike firing rate during repetitive stimulation and this transient response may be more important than the steady state response for reflex control. In the current study previously used system identification methods are developed and applied to investigate both steady state and transient dynamic and nonlinear changes in the neural circuit responsible for controlling reflex movements of the locust hind limbs. Through the use of a parsimonious model structure and Monte Carlo simulations we conclude that key system dynamics remain relatively unchanged during repetitive stimulation while output amplitude adaptation is occurring. Whilst some evidence of a significant change was found in parts of the systems nonlinear response, the effect was small and probably of little physiological relevance. Analysis using biologically more realistic stimulation reinforces this conclusion.

  11. Response of lymphatics of canine hind limb to sympathetic nerve stimulation.

    PubMed

    Browse, N L

    1968-07-01

    1. The changes in lymphatic pressure in a limb whose circulation was temporarily arrested with a pneumatic cuff have been studied.2. Stimulation of the lumbar sympathetic chain caused an increase in lymphatic pressure. It has been shown that this is a primary not a secondary phenomenon, due to an active lymphomotor mechanism.3. The increase of lymphatic tone is proportional to the rate of stimulation; peak values are reached between 5 and 9 impulses/sec.

  12. Study of Hind Limb Tissue Gas Phase Formation in Response to Suspended Adynamia and Hypokinesia

    NASA Technical Reports Server (NTRS)

    Butler, Bruce D.

    1996-01-01

    The purpose of this study was to investigate the hypothesis that reduced joint/muscle activity (hypo kinesia) as well as reduced or null loading of limbs (adynamia) in gravity would result in reduced decompression-induced gas phase and symptoms of decompression sickness (DCS). Finding a correlation between the two phenomena would correspond to the proposed reduction in tissue gas phase formation in astronauts undergoing decompression during extravehicular activity (EVA) in microgravity. The observation may further explain the reported low incidence of DCS in space.

  13. Effects of stretching and disuse on amino acids in muscles of rat hind limbs

    NASA Technical Reports Server (NTRS)

    Jaspers, Stephen R.; Henriksen, Erik J.; Satarug, Soisungwan; Tischler, Marc E.

    1989-01-01

    The effects of disuse and passive stretch on the concentrations of amino acids and ammonia in the unloaded soleus muscle was investigated in hindquarter-suspended (for six days by casting one foot in dorsiflexion) tail-casted rats. For a comparison with the condition of unloading, amino acids and ammonia were also measured in shortened extensor digitorum longus in the same casted limb and in denervated leg muscles. The results obtained suggest that passive stretch diminishes some of the characteristic alterations of amino acid concentrations due to unloading. This effect of stretch is considered to be due to the maintenance of muscle tension.

  14. Effect of picroside II on erythrocyte deformability and lipid peroxidation in rats subjected to hind limb ischemia reperfusion injury

    PubMed Central

    Çomu, Faruk Metin; Kılıç, Yiğit; Özer, Abdullah; Kirişçi, Mehmet; Dursun, Ali Doğan; Tatar, Tolga; Zor, Mustafa Hakan; Kartal, Hakan; Küçük, Ayşegül; Boyunağa, Hakan; Arslan, Mustafa

    2016-01-01

    Background Ischemia reperfusion injury (I/R) in hind limb is a frequent and important clinical phenomenon. Many structural and functional damages are observed in cells and tissues in these kinds of injuries. In this study, we aimed to evaluate the effect of picroside II on lipid peroxidation and erythrocyte deformability during I/R in rats. Methods Rats were randomly divided into four groups – each containing six animals (sham, I/R, sham + picroside II, and I/R + picroside II). The infrarenal section of the abdominal aorta was occluded with an atraumatic microvascular clamp in I/R groups. The clamp was removed after 120 minutes and reperfusion was provided for a further 120 minutes. Picroside II (10 mg·kg−1) was administered intraperitoneally to the animals in the appropriate groups (sham + picroside II, I/R + picroside II groups). All rats were euthanized by intraperitoneal administration of ketamine (100 mg·kg−1) and taking blood from the abdominal aorta. Erythrocytes were extracted from heparinized complete blood samples. Buffer (PT) and then erythrocytes (PE) were passed through the filtration system and the changes in pressure were measured to investigate the role of serum malondialdehyde and nitric oxide (NO) in lipid peroxidation and erythrocyte deformability index. Results Deformability index was significantly increased in the I/R group compared to groups sham, sham + picroside-II, and I/R + picroside-II (P<0.0001, P<0.0001, and P=0.007). Malondialdehyde (MDA) and NO levels were evaluated. MDA level and NO activity were also higher in the I/R group than in the other groups. Picroside II treatment before hind limb I/R prevented these changes. Conclusion These results support that deformability of erythrocytes is decreased in I/R injury and picroside II plays a critical role to prevent these alterations. Further experimental and clinical studies are needed to evaluate and clarify the molecular mechanisms of action and clinical importance of these

  15. Young's modulus and SEM analysis of leg bones exposed to simulated microgravity by hind limb suspension (HLS)

    SciTech Connect

    Patel, Niravkumar D.; Mehta, Rahul; Ali, Nawab; Soulsby, Michael; Chowdhury, Parimal

    2013-04-19

    The aim of this study was to determine composition of the leg bone tissue of rats that were exposed to simulated microgravity by Hind-Limb Suspension (HLS) by tail for one week. The leg bones were cross sectioned, cleaned of soft tissues, dried and sputter coated, and then placed horizontally on the stage of a Scanning Electron Microscope (SEM) for analysis. Interaction of a 17.5 keV electron beam, incident from the vertical direction on the sample, generated images using two detectors. X-rays emitted from the sample during electron bombardment were measured with an Energy Dispersive Spectroscopy (EDS) feature of SEM using a liquid-nitrogen cooled Si(Li) detector with a resolution of 144 eV at 5.9 keV ({sub 25}Mn K{sub {alpha}} x-ray). K{sub {alpha}}- x-rays from carbon, oxygen, phosphorus and calcium formed the major peaks in the spectrum. Relative percentages of these elements were determined using a software that could also correct for ZAF factors namely Z(atomic number), A(X-ray absorption) and F(characteristic fluorescence). The x-rays from the control groups and from the experimental (HLS) groups were analyzed on well-defined parts (femur, tibia and knee) of the leg bone. The SEM analysis shows that there are definite changes in the hydroxyl or phosphate group of the main component of the bone structure, hydroxyapatite [Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2}], due to hind limb suspension. In a separate experiment, entire leg bones (both from HLS and control rats) were subjected to mechanical stress by mean of a variable force. The stress vs. strain graph was fitted with linear and polynomial function, and the parameters reflecting the mechanical strength of the bone, under increasing stress, were calculated. From the slope of the linear part of the graph the Young's modulus for HLS bones were calculated and found to be 2.49 times smaller than those for control bones.

  16. Quantitative evaluation of bone development of the distal phalanx of the cow hind limb using computed tomography.

    PubMed

    Tsuka, T; Ooshita, K; Sugiyama, A; Osaki, T; Okamoto, Y; Minami, S; Imagawa, T

    2012-01-01

    Computed tomography (CT) was performed on 400 claws (200 inner and 200 outer claws) of 100 pairs of bovine hind limbs to investigate the etiological theory that an exacerbating factor for ulceration is exostosis of the tuberculum flexorium within the distal phalanx. A variety of morphological changes of the tuberculum flexorium of bovine hind limb claws was visualized by 3-dimensional CT, and the geometry of these claws suggested a growth pattern of bone development with respect to the assumed daily loading patterns. This growth occurs initially at the abaxial caudal aspect of the distal phalanx and is followed by horizontal progression toward the axial aspect. The length of downward bone development on the solar face of the distal phalanx was 2.73±1.32 mm in the outer claws, significantly greater than in the inner claws (2.38±0.96 mm). Ratios of downward (vertical) bone development to the thickness of the subcutis and the corium (VerBD ratios) did not differ between the outer and inner claws (36.7 vs. 38.3%, respectively). Ratios of horizontal bone development to the axial-to-abaxial line of the tuberculum flexorium (HorBD ratios) were approximately 60% for both outer and inner claws. These quantitative measures regarding horizontal and vertical bone development within the distal phalanx were positively correlated with age and VerBD ratios (r=0.53 and r=0.36 for the inner and outer claws, respectively). Correlations between claw width of the outer claw and length of vertical bone development (r=0.43), the HorBD ratio (r=0.51), and the VerBD ratio (r=0.42) suggested that the relative size difference between the inner and outer claws enhances bone development in the outer claw. Correlation coefficients between VerBD and HorBD ratios (r=0.52 and 0.63 for the inner and outer claws, respectively) suggested that horizontal and vertical bone development occurs as a synchronized process within the tuberculum flexorium. This age-related progress of bone development

  17. Young's modulus and SEM analysis of leg bones exposed to simulated microgravity by hind limb suspension (HLS)

    NASA Astrophysics Data System (ADS)

    Patel, Niravkumar D.; Mehta, Rahul; Ali, Nawab; Soulsby, Michael; Chowdhury, Parimal

    2013-04-01

    The aim of this study was to determine composition of the leg bone tissue of rats that were exposed to simulated microgravity by Hind-Limb Suspension (HLS) by tail for one week. The leg bones were cross sectioned, cleaned of soft tissues, dried and sputter coated, and then placed horizontally on the stage of a Scanning Electron Microscope (SEM) for analysis. Interaction of a 17.5 keV electron beam, incident from the vertical direction on the sample, generated images using two detectors. X-rays emitted from the sample during electron bombardment were measured with an Energy Dispersive Spectroscopy (EDS) feature of SEM using a liquid-nitrogen cooled Si(Li) detector with a resolution of 144 eV at 5.9 keV (25Mn Kα x-ray). Kα- x-rays from carbon, oxygen, phosphorus and calcium formed the major peaks in the spectrum. Relative percentages of these elements were determined using a software that could also correct for ZAF factors namely Z(atomic number), A(X-ray absorption) and F(characteristic fluorescence). The x-rays from the control groups and from the experimental (HLS) groups were analyzed on well-defined parts (femur, tibia and knee) of the leg bone. The SEM analysis shows that there are definite changes in the hydroxyl or phosphate group of the main component of the bone structure, hydroxyapatite [Ca10(PO4)6(OH)2], due to hind limb suspension. In a separate experiment, entire leg bones (both from HLS and control rats) were subjected to mechanical stress by mean of a variable force. The stress vs. strain graph was fitted with linear and polynomial function, and the parameters reflecting the mechanical strength of the bone, under increasing stress, were calculated. From the slope of the linear part of the graph the Young's modulus for HLS bones were calculated and found to be 2.49 times smaller than those for control bones.

  18. Actions on gamma-motoneurones elicited by electrical stimulation of cutaneous afferent fibres in the hind limb of the cat.

    PubMed

    Johansson, H; Sojka, P

    1985-09-01

    The reflex actions elicited by graded electrical stimulation of hind-limb cutaneous (sural, superficial peroneal and tibial) nerves were investigated with intra- and extracellular micro-electrode recordings in gamma-motoneurones projecting to hind-limb muscles in twenty-four cats anaesthetized with alpha-chloralose. In total, reflex responses of 100 gamma-motoneurones were analysed. 82 of the gamma-cells were classified as dynamic (43) or static (39) using the method of mesencephalic stimulation (Appelberg, Hulliger, Johansson & Sojka, 1982). The general responsiveness (i.e. number of input nerves with effect/number of input nerves tested) of the whole sample of gamma-cells to stimulation of skin nerves was extremely high (94.8%). All negative observations were encountered among static and non-classified gamma-cells. Generally, the stimulation strengths needed for evoking effects in the gamma-cells were very low. A majority of the excitatory effects in the dynamic cells appeared with stimulation intensities below 1.5 threshold (T), while most static cells were excited with stimulation strengths between 1.5 and 2 T. Also a statistical comparison of the populations of stimulation strength thresholds for the excitatory effects revealed a significant difference (P less than 0.0009) between dynamic and static gamma-cells. By contrast, the thresholds for inhibitory effects in dynamic cells were slightly higher than for excitatory effects (P less than 0.0009). As regards excitation of static cells, inhibition of dynamic cells and inhibition of static cells, no statistically significant threshold differences were found. A strong dominance of excitation over inhibition was found in both dynamic and static flexor (posterior biceps and semitendinosus) gamma-motoneurones from all input nerves. In comparison to flexor gamma-motoneurones, there was a much higher incidence of inhibitory and mixed (excitatory and inhibitory) responses in extensor (triceps) gamma-motoneurones, from

  19. Segment and joint angles of hind limb during bipedal and quadrupedal walking of the bonobo (Pan paniscus).

    PubMed

    D'Août, Kristiaan; Aerts, Peter; De Clercq, Dirk; De Meester, Koen; Van Elsacker, Linda

    2002-09-01

    We describe segment angles (trunk, thigh, shank, and foot) and joint angles (hip, knee, and ankle) for the hind limbs of bonobos walking bipedally ("bent-hip bent-knee walking," 17 sequences) and quadrupedally (33 sequences). Data were based on video recordings (50 Hz) of nine subjects in a lateral view, walking at voluntary speed. The major differences between bipedal and quadrupedal walking are found in the trunk, thigh, and hip angles. During bipedal walking, the trunk is approximately 33-41 degrees more erect than during quadrupedal locomotion, although it is considerably more bent forward than in normal human locomotion. Moreover, during bipedal walking, the hip has a smaller range of motion (by 12 degrees ) and is more extended (by 20-35 degrees ) than during quadrupedal walking. In general, angle profiles in bonobos are much more variable than in humans. Intralimb phase relationships of subsequent joint angles show that hip-knee coordination is similar for bipedal and quadrupedal walking, and resembles the human pattern. The coordination between knee and ankle differs much more from the human pattern. Based on joint angles observed throughout stance phase and on the estimation of functional leg length, an efficient inverted pendulum mechanism is not expected in bonobos.

  20. FACS-purified myoblasts producing controlled VEGF levels induce safe and stable angiogenesis in chronic hind limb ischemia.

    PubMed

    Wolff, Thomas; Mujagic, Edin; Gianni-Barrera, Roberto; Fueglistaler, Philipp; Helmrich, Uta; Misteli, Heidi; Gurke, Lorenz; Heberer, Michael; Banfi, Andrea

    2012-01-01

    We recently developed a method to control the in vivo distribution of vascular endothelial growth factor (VEGF) by high throughput Fluorescence-Activated Cell Sorting (FACS) purification of transduced progenitors such that they homogeneously express specific VEGF levels. Here we investigated the long-term safety of this method in chronic hind limb ischemia in nude rats. Primary myoblasts were transduced to co-express rat VEGF-A(164) (rVEGF) and truncated ratCD8a, the latter serving as a FACS-quantifiable surface marker. Based on the CD8 fluorescence of a reference clonal population, which expressed the desired VEGF level, cells producing similar VEGF levels were sorted from the primary population, which contained cells with very heterogeneous VEGF levels. One week after ischemia induction, 12 × 10(6) cells were implanted in the thigh muscles. Unsorted myoblasts caused angioma-like structures, whereas purified cells only induced normal capillaries that were stable after 3 months. Vessel density was doubled in engrafted areas, but only approximately 0.1% of muscle volume showed cell engraftment, explaining why no increase in total blood flow was observed. In conclusion, the use of FACS-purified myoblasts granted the cell-by-cell control of VEGF expression levels, which ensured long-term safety in a model of chronic ischemia. Based on these results, the total number of implanted cells required to achieve efficacy will need to be determined before a clinical application.

  1. RIP2-mediated LKB1 deletion causes axon degeneration in the spinal cord and hind-limb paralysis.

    PubMed

    Sun, Gao; Reynolds, Richard; Leclerc, Isabelle; Rutter, Guy A

    2011-03-01

    Axon degeneration is observed in neurodegenerative diseases and neuroinflammatory disorders, such as Alzheimer's disease, Parkinson's disease and multiple sclerosis. The molecular basis of this process remains largely unknown. Here, we show that mice deleted for the tumour suppressor LKB1 (also called STK11) in the spinal cord, some parts of the brain and in the endocrine pancreas (βLKB1KO mice) develop hind-limb dysfunction and axon degeneration at about 7 weeks. Demyelination and macrophage infiltration are observed in the white matter of these mice, predominantly in the bilateral and anterior funiculi of the thoracic segment of the spinal cord, suggesting damage to the ascending sensory signalling pathway owing to LKB1 deletion in the brain. Microtubule structures were also affected in the degenerated foci, with diminished neurofilament and tubulin expression. Deletion of both PRKAA1 genes, whose products AMPKα1 and AMPKα2 are also downstream targets of LKB1, with the same strategy was without effect. We thus define LKB1 as an intrinsic suppressor of axon degeneration and a possible target for strategies that can reverse this process.

  2. Real-time control of hind limb functional electrical stimulation using feedback from dorsal root ganglia recordings

    PubMed Central

    Bruns, Tim M; Wagenaar, Joost B; Bauman, Matthew J; Gaunt, Robert A; Weber, Douglas J

    2013-01-01

    Objective Functional electrical stimulation (FES) approaches often utilize an open-loop controller to drive state transitions. The addition of sensory feedback may allow for closed-loop control that can respond effectively to perturbations and muscle fatigue. Approach We evaluated the use of natural sensory nerve signals obtained with penetrating microelectrode arrays in lumbar dorsal root ganglia (DRG) as real-time feedback for closed-loop control of FES-generated hind limb stepping in anesthetized cats. Main results Leg position feedback was obtained in near real-time at 50 ms intervals by decoding the firing rates of more than 120 DRG neurons recorded simultaneously. Over 5 m of effective linear distance was traversed during closed-loop stepping trials in each of two cats. The controller compensated effectively for perturbations in the stepping path when DRG sensory feedback was provided. The presence of stimulation artifacts and the quality of DRG unit sorting did not significantly affect the accuracy of leg position feedback obtained from the linear decoding model as long as at least 20 DRG units were included in the model. Significance This work demonstrates the feasibility and utility of closed-loop FES control based on natural neural sensors. Further work is needed to improve the controller and electrode technologies and to evaluate long-term viability. PMID:23503062

  3. Real-time control of hind limb functional electrical stimulation using feedback from dorsal root ganglia recordings

    NASA Astrophysics Data System (ADS)

    Bruns, Tim M.; Wagenaar, Joost B.; Bauman, Matthew J.; Gaunt, Robert A.; Weber, Douglas J.

    2013-04-01

    Objective. Functional electrical stimulation (FES) approaches often utilize an open-loop controller to drive state transitions. The addition of sensory feedback may allow for closed-loop control that can respond effectively to perturbations and muscle fatigue. Approach. We evaluated the use of natural sensory nerve signals obtained with penetrating microelectrode arrays in lumbar dorsal root ganglia (DRG) as real-time feedback for closed-loop control of FES-generated hind limb stepping in anesthetized cats. Main results. Leg position feedback was obtained in near real-time at 50 ms intervals by decoding the firing rates of more than 120 DRG neurons recorded simultaneously. Over 5 m of effective linear distance was traversed during closed-loop stepping trials in each of two cats. The controller compensated effectively for perturbations in the stepping path when DRG sensory feedback was provided. The presence of stimulation artifacts and the quality of DRG unit sorting did not significantly affect the accuracy of leg position feedback obtained from the linear decoding model as long as at least 20 DRG units were included in the model. Significance. This work demonstrates the feasibility and utility of closed-loop FES control based on natural neural sensors. Further work is needed to improve the controller and electrode technologies and to evaluate long-term viability.

  4. Expression of nestin, desmin and vimentin in intact and regenerating muscle spindles of rat hind limb skeletal muscles.

    PubMed

    Cízková, Dana; Soukup, Tomás; Mokrý, Jaroslav

    2009-02-01

    We describe the expression and distribution patterns of nestin, desmin and vimentin in intact and regenerating muscle spindles of the rat hind limb skeletal muscles. Regeneration was induced by intramuscular isotransplantation of extensor digitorum longus (EDL) or soleus muscles from 15-day-old rats into the EDL muscle of adult female inbred Lewis rats. The host muscles with grafts were excised after 7-, 16-, 21- and 29-day survival and immunohistochemically stained. Nestin expression in intact spindles in host muscles was restricted to Schwann cells of sensory and motor nerves. In transplanted muscles, however, nestin expression was also found in regenerating "spindle fibers", 7 and 16 days after grafting. From the 21st day onwards, the regenerated spindle fibers were devoid of nestin immunoreactivity. Desmin was detected in spindle fibers at all developmental stages in regenerating as well as in intact spindles. Vimentin was expressed in cells of the outer and inner capsules of all muscle spindles and in newly formed myoblasts and myotubes of regenerating spindles 7 days after grafting. Our results show that the expression pattern of these intermediate filaments in regenerating spindle fibers corresponds to that found in regenerating extrafusal fibers, which supports our earlier suggestion that they resemble small-diameter extrafusal fibers.

  5. Implanting iodine-125 seeds into rat dorsal root ganglion for neuropathic pain: neuronal microdamage without impacting hind limb motion.

    PubMed

    Jiao, Ling; Zhang, Tengda; Wang, Huixing; Zhang, Wenyi; Fan, Saijun; Huo, Xiaodong; Zheng, Baosen; Ma, Wenting

    2014-06-15

    The use of iodine-125 ((125)I) in cancer treatment has been shown to relieve patients' pain. Considering dorsal root ganglia are critical for neural transmission between the peripheral and central nervous systems, we assumed that (125)I could be implanted into rat dorsal root ganglia to provide relief for neuropathic pain. (125)I seeds with different radioactivity (0, 14.8, 29.6 MBq) were implanted separately through L4-5 and L5-6 intervertebral foramen into the vicinity of the L5 dorsal root ganglion. von Frey hair results demonstrated the mechanical pain threshold was elevated after implanting (125)I seeds from the high radioactivity group. Transmission electron microscopy revealed that nuclear membrane shrinkage, nucleolar margination, widespread mitochondrial swelling, partial vacuolization, lysosome increase, and partial endoplasmic reticulum dilation were visible at 1,440 hours in the low radioactivity group and at 336 hours in the high radioactivity group. Abundant nuclear membrane shrinkage, partial fuzzy nuclear membrane and endoplasmic reticulum necrosis were observed at 1,440 hours in the high radioactivity group. No significant difference in combined behavioral scores was detected between preoperation and postoperation in the low and high radioactivity groups. These results suggested that the mechanical pain threshold was elevated after implanting (125)I seeds without influencing motor functions of the hind limb, although cell injury was present.

  6. Angiogenesis effect of therapeutic ultrasound on ischemic hind limb in mice

    PubMed Central

    Huang, Jing-Juan; Shi, Yi-Qin; Li, Rui-Lin; Hu, An; Zhou, Hong-Sheng; Cheng, Qian; Xu, Zheng; Yang, Zhi-Ming; Hao, Chang-Ning; Duan, Jun-Li

    2014-01-01

    Although significant progress in bypass surgery and catheter intervention against peripheral artery disease, the number of severe critical limb ischemia (CLI) patients is increasing. Thus, it is crucial to develop new, non-invasive therapeutic strategies. The purpose of this study was to determine the mechanism of therapeutic ultrasound (TUS) on ischemic angiogenesis using mouse model of hindlimb ischemia and the cellular/molecular mechanisms underlying TUS-related neovascularization. The hindlimb ischemic mice were exposed to extracorporeal TUS for 3, 6, 9 minute per day (1 MHz, 0.3 W/cm2) until day 14 after left femoral artery ligation. Increased blood perfusion and capillary density were determined following 9 min of TUS compared with ischemic group. Moreover, TUS treatment increased the protein levels of vascular endothelial growth factor (VEGF), hypoxic inducible factor-1α (HIF-1α), endothelial nitric oxide synthase (eNOS) and p-Akt in vivo. TUS promoted capillary-like tube formation, migration and motility of human umbilical venous endothelial cells (HUVECs). Furthermore, the protein expressions of VEGF, eNOS and p-Akt were increased after TUS treatment. In conclusion, TUS therapy promotes postnatal neovascularization through multiple angiogenic pathways in mice model of ischemic hindlimb. PMID:25628781

  7. Fasting increases palmitic acid incorporation into rat hind-limb intramuscular acylglycerols while short-term cold exposure has no effect.

    PubMed

    Synak, M; Zarzeczny, R; Górecka, M; Langfort, J; Kaciuba-Uściłko, H; Zernicka, Ewa

    2011-09-01

    The aim of the study was to investigate the palmitic acid incorporation into intramuscular acylglycerols in perfused hind-limb skeletal muscles of different fibre types in rats either fasted for 48 h or exposed to cold (6 °C) for 12 h. Hind-limb preparations of fasted and cold exposed rats were perfused with buffers containing tritium labelled and cold palmitic acid. Palmitic acid incorporation into intracellular lipid pools in the soleus, plantaris, red and white gastrocnemius and red and white quadriceps was measured. It was found that fasting increased approximately 2-fold palmitic acid incorporation in all muscles examined regardless of the fibre type composition of the muscle. On the other hand, exposure to cold had no effect on the palmitic acid incorporation into intramuscular acylglycerols regardless the muscle fibre type. The increased incorporation of palmitic acid into acylglycerols in fasted animals is in line with data showing that 48 h fasting stimulates the expression of plasma membrane proteins putatively facilitating fatty acid uptake. It appears that although 12 h cold exposure increases the use of fatty acids as energy substrates it does not alter the incorporation of palmitic acid into intramuscular acylglycerols in the perfused rat hind-limb.

  8. Longitudinal evaluation of mouse hind limb bone loss after spinal cord injury using novel, in vivo, methodology.

    PubMed

    McManus, Madonna M; Grill, Raymond J

    2011-12-07

    Spinal cord injury (SCI) is often accompanied by osteoporosis in the sublesional regions of the pelvis and lower extremities, leading to a higher frequency of fractures. As these fractures often occur in regions that have lost normal sensory function, the patient is at a greater risk of fracture-dependent pathologies, including death. SCI-dependent loss in both bone mineral density (BMD, grams/cm2) and bone mineral content (BMC, grams) has been attributed to mechanical disuse, aberrant neuronal signaling and hormonal changes. The use of rodent models of SCI-induced osteoporosis can provide invaluable information regarding the mechanisms underlying the development of osteoporosis following SCI as well as a test environment for the generation of new therapies. Mouse models of SCI are of great interest as they permit a reductionist approach to mechanism-based assessment through the use of null and transgenic mice. While such models have provided important data, there is still a need for minimally-invasive, reliable, reproducible, and quantifiable methods in determining the extent of bone loss following SCI, particularly over time and within the same cohort of experimental animals, to improve diagnosis, treatment methods, and/or prevention of SCI-induced osteoporosis. An ideal method for measuring bone density in rodents would allow multiple, sequential (over time) exposures to low-levels of X-ray radiation. This study describes the use of a new whole-animal scanner, the IVIS Lumina XR (Caliper Instruments) that can be used to provide low-energy (1-3 milligray (mGy)) high-resolution, high-magnification X-ray images of mouse hind limb bones over time following SCI. Significant bone density loss was seen in the tibiae of mice by 10 days post-spinal transection when compared to uninjured, age-matched control (naïve) mice (13% decrease, p < 0.0005). Loss of bone density in the distal femur was also detectable by day 10 post-SCI, while a loss of density in the proximal

  9. Calcium-dependent signalling is essential during collateral growth in the pig hind limb-ischemia model.

    PubMed

    Troidl, C; Nef, H; Voss, S; Schilp, A; Kostin, S; Troidl, K; Szardien, S; Rolf, A; Schmitz-Rixen, T; Schaper, W; Hamm, C W; Elsässer, A; Möllmann, H

    2010-07-01

    We investigated the effect of pharmacological activation of the Ca(2+)-channel transient receptor potential cation channel, subfamily V, member 4 (TRPV4) on collateral growth in a pig hind limb-ischemia model thereby identifying subcellular mechanisms. Domestic pigs received femoral artery ligature and were randomly assigned to one of the following groups (each n=6): (1) 4alpha-phorbol 12,13-didecanoate (4alphaPDD) treatment; (2) treatment with an arterio-venous shunt (AV-shunt) distal to the occlusion; or (3) implantation of NaCl-filled minipump. Six sham-operated pigs acted as controls. Aortic and peripheral mean arterial pressure (MAP) measurements were performed to assess the collateral flow index (CFI). Tissue was isolated from M. quadriceps for immunohistochemistry and from isolated collateral arteries for quantitative real time PCR (qRT-PCR). Shortly after ligature the CFI dropped from 0.96+/-0.02 to 0.21+/-0.02 in all ligature-treated groups. In ligature-only-treated pigs CFI increased to 0.56+/-0.03 after 7days. Treatment with 4alphaPDD led to an enhancement of CFI compared with ligature alone (0.73+/-0.03). CD31-staining showed improved arteriolar density. Increased Ki67 staining in collaterals indicated proliferation. qRT-PCR and Western blot analysis showed upregulation or modulation of Ca(2+)-dependent transcription factors nuclear factor of activated T-cells, cytoplasmic, calcineurin-dependent 1 (NFATc1), Kv channel interacting protein 3, calsenilin (KCNIP3/CSEN/DREAM), and myocyte enhancer factor 2C (MEF2C) in 4alphaPDD- and AV-shunt-treated pigs compared with controls. Improved CFI after 4alphaPDD treatment identifies TRPV4 as an initial fluid shear-stress sensor and collateral remodelling and growth trigger. Subcellularly, modulation of Ca(2+)-dependent transcription factors indicates a pivotal role for Ca(2+)-signalling during arteriogenesis.

  10. Treatment effect with anti-RAGE F(ab')2 antibody improves hind limb angiogenesis and blood flow in Type 1 diabetic mice with left femoral artery ligation.

    PubMed

    Tekabe, Yared; Anthony, Tamykah; Li, Qing; Ray, Rashmi; Rai, Vivek; Zhang, Geping; Schmidt, Ann Marie; Johnson, Lynne L

    2015-06-01

    We investigated treatment with a receptor for advanced glycation endproduct (RAGE) blocking antibody on angiogenic response to hind limb ischemia in diabetic mice. Streptozotocin treated C57BL/6 mice received either murine monoclonal anti-RAGE F(ab')2 intraperitoneally (n=10) or saline (n=9) for 9 weeks. Diabetic plus 10 non-diabetic C57BL/6 mice underwent left femoral artery ligation and 5 days later angiogenesis imaging with (99m)Tc-Arg-Gly-Asp (RGD) nanoSPECT/CT. Twenty-four days later, hind limb blood flow was measured with ultrasound, the mice were euthanized, and tissue was taken for immunohistochemistry. The angiogenic imaging signal in ischemic limbs was higher in RAGE-ab treated versus saline treated mice at day 5 (3.1±1.4 vs 1.68±0.35, p=0.02) and blood flow was higher at day 24 (1.49±0.5 vs 0.61±0.39, p=0.04). Immunohistochemistry of ischemic muscles showed greater capillary density in the RAGE-ab treated group versus the vehicle-treated group (p<0.001) (NS from non-diabetic mice). In conclusion, treatment with anti-RAGE F(ab')2 in diabetic mice improves neovascularization in the ischemic leg.

  11. GM-CSF treated F4/80+ BMCs improve murine hind limb ischemia similar to M-CSF differentiated macrophages.

    PubMed

    Kuwahara, Go; Nishinakamura, Hitomi; Kojima, Daibo; Tashiro, Tadashi; Kodama, Shohta

    2014-01-01

    Novel cell therapy is required to treat critical limb ischemia (CLI) as many current approaches require repeated aspiration of bone marrow cells (BMCs). The use of cultured BMCs can reduce the total number of injections required and were shown to induce therapeutic angiogenesis in a murine model of hind limb ischemia. Blood flow recovery was significantly improved in mice treated with granulocyte-macrophage colony-stimulating factor (GM-CSF)-dependent BMCs that secreted inflammatory cytokines. Angiogenesis, lymphangiogenesis, and blood flow recovery ratio were significantly higher in the GM-CSF-cultured F4/80+ macrophage (GM-Mø)-treated group compared with controls. Furthermore, Foxp3+ cell numbers and tissue IL-10 concentrations were significantly increased compared with controls. There was no significant difference in blood flow recovery between GM-Mø and M-CSF-cultured F4/80+ macrophages (M-Mø). Thus, GM-Mø were associated with improved blood flow in hind limb ischemia similar to M-Mø. The selective methods of culturing and treating GM-Mø cells similar to M-Mø cells could be used clinically to help resolve the large number of cells required for BMC treatment of CLI. This study demonstrates a novel cell therapy for CLI that can be used in conjunction with conventional therapy including percutaneous intervention and surgical bypass.

  12. Effects of N-acetylcysteine and pentoxifylline on remote lung injury in a rat model of hind-limb ischemia/reperfusion injury

    PubMed Central

    Takhtfooladi, Hamed Ashrafzadeh; Hesaraki, Saeed; Razmara, Foad; Takhtfooladi, Mohammad Ashrafzadeh; Hajizadeh, Hadi

    2016-01-01

    Objective : To investigate the effects of N-acetylcysteine (NAC) and pentoxifylline in a model of remote organ injury after hind-limb ischemia/reperfusion (I/R) in rats, the lungs being the remote organ system. Methods : Thirty-five male Wistar rats were assigned to one of five conditions (n = 7/group), as follows: sham operation (control group); hind-limb ischemia, induced by clamping the left femoral artery, for 2 h, followed by 24 h of reperfusion (I/R group); and hind-limb ischemia, as above, followed by intraperitoneal injection (prior to reperfusion) of 150 mg/kg of NAC (I/R+NAC group), 40 mg/kg of pentoxifylline (I/R+PTX group), or both (I/R+NAC+PTX group). At the end of the trial, lung tissues were removed for histological analysis and assessment of oxidative stress. Results : In comparison with the rats in the other groups, those in the I/R group showed lower superoxide dismutase activity and glutathione levels, together with higher malondialdehyde levels and lung injury scores (p < 0.05 for all). Interstitial inflammatory cell infiltration of the lungs was also markedly greater in the I/R group than in the other groups. In addition, I/R group rats showed various signs of interstitial edema and hemorrhage. In the I/R+NAC, I/R+PTX, and I/R+NAC+PTX groups, superoxide dismutase activity, glutathione levels, malondialdehyde levels, and lung injury scores were preserved (p < 0.05 for all). The differences between the administration of NAC or pentoxifylline alone and the administration of the two together were not significant for any of those parameters (p > 0.05 for all). Conclusions : Our results suggest that NAC and pentoxifylline both protect lung tissue from the effects of skeletal muscle I/R. However, their combined use does not appear to increase the level of that protection. PMID:26982035

  13. A flexible electrode array for muscle impedance measurements in the mouse hind limb: A tool to speed research in neuromuscular disease

    NASA Astrophysics Data System (ADS)

    Li, J.; Rutkove, S. B.

    2013-04-01

    Electrical impedance myography (EIM) is a bioelectrical impedance technique focused on the assessment of neuromuscular diseases using tetrapolar surface arrays. Recently, we have shown that reproducible and sensitive EIM measurements can be made on the gastrocnemius muscle of the mouse hind limb and that these are sensitive to disease alterations. A dedicated array would help speed data acquisition and provide additional sensitivity to disease-induced alterations. A flexible electrode array was developed with electrode sizes of 1mm × 1mm by Parlex, Inc. Tetrapolar electrode sets were arranged both parallel to (longitudinal) and orthogonally to (transverse) the major muscle fiber direction of the gastrocnemius muscle. Measurements were made with a dedicated EIM system. A total of 11 healthy animals and 7 animals with spinal muscular atrophy (a form of motor neuron disease) were evaluated after the fur was completely removed with a depilatory agent from the hind limb. Standard electrophysiologic testing (compound motor action potential amplitude and motor unit number estimation) was also performed. The flexible electrode array demonstrated high repeatability in both the longitudinal and transverse directions in the healthy and diseased animals (with intraclass correlation coefficients of 0.94 and 0.89, respectively, for phase angle measured transversely). In addition, differences between healthy and diseased animals were identifiable. For example, the 50 kHz transverse phase angle was higher in the healthy as compared to the SMA animals (16.8° ± 0.5 vs. 14.3° ± 0.7, respectively) at 21 weeks of age (p = 0.01). Differences in anisotropy were also identifiable. Correlations to several standard neurophysiologic parameters also appeared promising. This novel flexible tetrapolar electrode array can be used on the mouse hind limb and provides multidirectional data that can be used to assess muscle health. This technique has the potential of finding widespread use in

  14. The Effects of Inclination (Up and Down) of the Treadmill on the Electromyogram Activities of the Forelimb and Hind limb Muscles at a Walk and a Trot in Thoroughbred Horses

    PubMed Central

    TAKAHASHI, Toshiyuki; MATSUI, Akira; MUKAI, Kazutaka; OHMURA, Hajime; HIRAGA, Atsushi; AIDA, Hiroko

    2014-01-01

    ABSTRACT It is important to know the effects of the inclination of a slope on the activity of each muscle, because training by running on a sloped track is commonly used for Thoroughbred racehorses. The effects of incline (from −6 to +6%) on the forelimbs and hind limbs during walking and trotting on a treadmill were evaluated by an integrated electromyogram (iEMG). The muscle activities in the forelimbs (5 horses) and hind limbs (4 horses) were measured separately. Two stainless steel wires were inserted into each of the brachiocephalicus (Bc), biceps brachii (BB), splenius (Sp), and pectoralis descendens (PD) in the forelimb experiment and into the longissimus dorsi (LD), vastus lateralis (VL), gluteus medius (GM), and biceps femoris (BF) in the hind limb experiment. The EMG recordings were taken at a sampling rate of 1,000 Hz. At a walk, the iEMG values for the forelimb were not significantly different under any of the inclinations. In the hind limb, the iEMG values for the GM and BF significantly decreased as the inclination decreased. At a trot, the iEMG values for the Bc in the forelimb significantly decreased as the inclination of the treadmill decreased. In the hind limb, the iEMG values for the LD, GM, and BF significantly decreased as the inclination decreased. Uphill exercise increased the iEMG values for the Bc, LD, GM, and BF, while downhill exercise resulted in little increase in the iEMG values. It was concluded that the effects of inclination on the muscle activities were larger for the uphill exercises, and for the hind limb muscles compared with the forelimb muscles. PMID:25558180

  15. The Effects of Inclination (Up and Down) of the Treadmill on the Electromyogram Activities of the Forelimb and Hind limb Muscles at a Walk and a Trot in Thoroughbred Horses.

    PubMed

    Takahashi, Toshiyuki; Matsui, Akira; Mukai, Kazutaka; Ohmura, Hajime; Hiraga, Atsushi; Aida, Hiroko

    2014-01-01

    It is important to know the effects of the inclination of a slope on the activity of each muscle, because training by running on a sloped track is commonly used for Thoroughbred racehorses. The effects of incline (from -6 to +6%) on the forelimbs and hind limbs during walking and trotting on a treadmill were evaluated by an integrated electromyogram (iEMG). The muscle activities in the forelimbs (5 horses) and hind limbs (4 horses) were measured separately. Two stainless steel wires were inserted into each of the brachiocephalicus (Bc), biceps brachii (BB), splenius (Sp), and pectoralis descendens (PD) in the forelimb experiment and into the longissimus dorsi (LD), vastus lateralis (VL), gluteus medius (GM), and biceps femoris (BF) in the hind limb experiment. The EMG recordings were taken at a sampling rate of 1,000 Hz. At a walk, the iEMG values for the forelimb were not significantly different under any of the inclinations. In the hind limb, the iEMG values for the GM and BF significantly decreased as the inclination decreased. At a trot, the iEMG values for the Bc in the forelimb significantly decreased as the inclination of the treadmill decreased. In the hind limb, the iEMG values for the LD, GM, and BF significantly decreased as the inclination decreased. Uphill exercise increased the iEMG values for the Bc, LD, GM, and BF, while downhill exercise resulted in little increase in the iEMG values. It was concluded that the effects of inclination on the muscle activities were larger for the uphill exercises, and for the hind limb muscles compared with the forelimb muscles.

  16. Connexions from large, ipsilateral hind limb muscle and skin afferents to the rostral main cuneate nucleus and to the nucleus X region in the cat.

    PubMed Central

    Johansson, H; Silfvenius, H

    1977-01-01

    1. Evidence is presented for an input from ipsilateral hind limb group I muscle afferents and low threshold cutaneous afferents, to cells in the rostral division of the main cuneate nucleus (rMCN) and in the region of the descending vestibular nucleus and the nucleus X of Brodal & Pompeiano (1957a), the (DV-X). 2. Thirteen group I-rMCN cells were recorded from. The functional properties of these cells were similar to those of nueleus Z (Landgren & Silfvenius, 1971; Johansson & Silfvenius, 1977a, b). The cells were monosynaptically linked to spinal dorsolateral fascicle (DLF) fibres. Nine cells projected to the contralateral thalamus, i.e. a second group I hind limb bulbothalamic tract is described. Ten cells were synaptically activated from the ipsilateral cerebellum from the anterior projection zone of the dorsal spinocerebellar tract (DSCT). Axon-collateral activation by DSCT fibres was established for two of these cells. They were both bulbothalamic relay cells. For the remaining eight cells, activated from the cerebellum, this was not proven. These cells could, however, either be linked to DSCT fibres or to short axon-collaterals of a cell body of unknown location. A projection from the rMCN to the cerebellum is described and agrees with recent anatomical findings. Two cells were not excited from the cerebellum. 3. Four rMCN cells were activated by cutaneous afferents with their secondary axons in the DLF. Suggestive evidence for a bulbothalamic cutaneous hind limb path via the rMCN is presented. Two cells were activated from the cerebellum, presumably via axon-collaterals of nonsegmental cells. 4. Eight group I-DV-X cells were recorded from. They were monosynaptically linked to spinal DLF fibres and resembled functionally the nucleus Z and rMCN cells when stimulated from the periphery. Two cells projected to the contralateral thalamus, and two others were synaptically excited. Seven cells were activated from the ipsilateral cerebellum. Two of them projected to

  17. Comparative Anatomy of the Hind Limb Vessels of the Bearded Capuchins (Sapajus libidinosus) with Apes, Baboons, and Cebus capucinus: With Comments on the Vessels' Role in Bipedalism

    PubMed Central

    Aversi-Ferreira, Roqueline A. G. M. F.; de Abreu, Tainá; Pfrimer, Gabriel A.; Silva, Sylla F.; Ziermann, Janine M.; Carneiro-e-Silva, Frederico O.; Tomaz, Carlos; Tavares, Maria Clotilde H.; Maior, Rafael S.; Aversi-Ferreira, Tales A.

    2013-01-01

    Capuchin monkeys are known to exhibit sporadic bipedalism while performing specific tasks, such as cracking nuts. The bipedal posture and locomotion cause an increase in the metabolic cost and therefore increased blood supply to lower limbs is necessary. Here, we present a detailed anatomical description of the capuchin arteries and veins of the pelvic limb of Sapajus libidinosus in comparison with other primates. The arterial pattern of the bearded capuchin hind limb is more similar to other quadrupedal Cebus species. Similarities were also found to the pattern observed in the quadruped Papio, which is probably due to a comparable pelvis and the presence of the tail. Sapajus' traits show fewer similarities when compared to great apes and modern humans. Moreover, the bearded capuchin showed unique patterns for the femoral and the short saphenous veins. Although this species switches easily from quadrupedal to bipedal postures, our results indicate that the bearded capuchin has no specific or differential features that support extended bipedal posture and locomotion. Thus, the explanation for the behavioral differences found among capuchin genera probably includes other aspects of their physiology. PMID:24396829

  18. Development of a twenty-one-component finite element distal hind limb model: stress and strain in bovine digit structures as a result of loading on different floorings.

    PubMed

    Hinterhofer, C; Haider, H; Apprich, V; Ferguson, J C; Collins, S N; Stanek, C

    2009-03-01

    Finite element modeling is a unique way of introducing technical and material research into medical science. A bovine distal hind limb was scanned using computed tomography for geometric image capture and the data were subsequently divided (segmented) into 4 tissue types: bone, bone marrow, soft tissue, and the horn capsule. Material data from previous studies were integrated into the model. Flexor tendons were assembled as longitudinal structures starting at their cross-sectional areas at the height of the metatarsophalangeal joint, proceeding in the plantaro-distal direction and meeting the distal phalanx at the tuberculum flexorium. Three different flooring situations (full support floor, bearing weight in the abaxial half of the lateral claw and in the dorsal halves of both claws, respectively) were created to evaluate the effects of loading. Full support resulted in von Mises stress levels between 3.5 and 1.5 MPa for the osseous structures and some regions of the segmented soft tissue; stress patterns in the bulb and sole of the claw capsule (1.5 MPa) and in the floor (0.5 MPa) were similar to pressure plate data in vivo and in vitro, with corresponding strain values of 2.4%. Reduced support resulted in higher stresses (up to approximately 8 MPa) in bones, claw capsules, and tendons; high strains ( approximately 11%) were found in the soft tissue, depending on how the floor was constructed. Although the models may still be anatomically improved, stress and strain calculations are possible with results comparable to related research, and the model shows interaction between the 2 digits. This possibly will help with further understanding of the biomechanical function of this 2-digit structure. With respect to clinical interpretation, reduced support to the bovine hind limb increases focal stress peaks in the different tissues, which may indicate a location of potential injury.

  19. Proteomic analysis of fibroblastema formation in regenerating hind limbs of Xenopus laevis froglets and comparison to axolotl

    PubMed Central

    2014-01-01

    Background To gain insight into what differences might restrict the capacity for limb regeneration in Xenopus froglets, we used High Performance Liquid Chromatography (HPLC)/double mass spectrometry to characterize protein expression during fibroblastema formation in the amputated froglet hindlimb, and compared the results to those obtained previously for blastema formation in the axolotl limb. Results Comparison of the Xenopus fibroblastema and axolotl blastema revealed several similarities and significant differences in proteomic profiles. The most significant similarity was the strong parallel down regulation of muscle proteins and enzymes involved in carbohydrate metabolism. Regenerating Xenopus limbs differed significantly from axolotl regenerating limbs in several ways: deficiency in the inositol phosphate/diacylglycerol signaling pathway, down regulation of Wnt signaling, up regulation of extracellular matrix (ECM) proteins and proteins involved in chondrocyte differentiation, lack of expression of a key cell cycle protein, ecotropic viral integration site 5 (EVI5), that blocks mitosis in the axolotl, and the expression of several patterning proteins not seen in the axolotl that may dorsalize the fibroblastema. Conclusions We have characterized global protein expression during fibroblastema formation after amputation of the Xenopus froglet hindlimb and identified several differences that lead to signaling deficiency, failure to retard mitosis, premature chondrocyte differentiation, and failure of dorsoventral axial asymmetry. These differences point to possible interventions to improve blastema formation and pattern formation in the froglet limb. PMID:25063185

  20. Effect of prolonged ischaemic time on muscular atrophy and regenerating nerve fibres in transplantation of the rat hind limb.

    PubMed

    Tsuji, Naoko; Yamashita, Shuji; Sugawara, Yasushi; Kobayashi, Eiji

    2012-09-01

    Our aim was to test the influence of cold ischaemia on replanted limbs, focusing on muscular atrophy and neurological recovery. Inbred wild-type and green fluorescent protein (GFP) transgenic (Tg) Lewis rats aged 8-10 weeks were used. The amputated limbs were transplanted at several cold ischaemic times (0, 1, 8, 12, 24, 48, and 72 hours). An arterial ischaemic model and a denervation model were used as controls. To study nerve regeneration, a GFP limb was transplanted on to the syngenic wild Lewis rat. These animals were evaluated histologically, electrophysiologically, and immunohistochemically. The longer the ischaemic time, the more evident was atrophy of the muscles. Electrophysiological investigation showed that the latency at 3 weeks was longer in the transplantation models than in the normal controls, particularly in the longer ischaemia group. Larger numbers of migrating Schwann cells were seen in the group with no delay than in the group that had been preserved for 12 hours. Ischaemia after amputation of a limb causes muscle cells to necrose and atrophy, and these changes worsen in proportion to the ischaemic preservation time. A delay in nerve regeneration and incomplete paralysis caused by malregeneration also affect muscular atrophy.

  1. Transfection of VEGF(165) genes into endothelial progenitor cells and in vivo imaging using quantum dots in an ischemia hind limb model.

    PubMed

    Yang, Han Na; Park, Ji Sun; Woo, Dae Gyun; Jeon, Su Yeon; Park, Keun-Hong

    2012-11-01

    Endothelial progenitor cells (EPCs) were transfected with fluorescently labeled quantum dot nanoparticles (QD NPs) with or without VEGF(165) plasmid DNA (pDNA) to probe the EPCs after in vivo transplantation and to test whether they presented as differentiated endothelial cells (ECs). Bare QD NPs and QD NPs coated with PEI or PEI + VEGF(165) genes were characterized by dynamic light scattering, scanning electron microscopy, and atomic force microscopy. Transfection of EPCs with VEGF(165) led to the expression of specific genes and proteins for mature ECs. A hind limb ischemia model was generated in nude mice, and VEGF(165) gene-transfected EPCs were transplanted intramuscularly into the ischemic limbs. At 28 days after transplantation, the VEGF(165) gene-transfected EPCs significantly increased the number of differentiated ECs compared with the injection of medium or bare EPCs without VEGF(165) genes. Laser Doppler imaging revealed that blood perfusion levels were increased significantly by VEGF(165) gene-transfected EPCs compared to EPCs without VEGF(165). Moreover, the transplantation of VEGF(165) gene-transfected EPCs increased the specific gene and protein expression levels of mature EC markers and angiogenic factors in the animal model.

  2. Data set incongruence and correlated character evolution: An example of functional convergence in the hind-limbs of stifftail diving ducks

    USGS Publications Warehouse

    McCracken, K.G.; Harshman, J.; Mcclellan, D.A.; Afton, A.D.

    1999-01-01

    The unwitting inclusion of convergent characters in phylogenetic estimates poses a serious problem for efforts to recover phylogeny. Convergence is not inscrutable, however, particularly when one group of characters tracks phylogeny and another set tracks adaptive history. In such cases, convergent characters may be correlated with one or a few functional anatomical units and readily identifiable by using comparative methods. Stifftail ducks (Oxyurinae) offer one such opportunity to study correlated character evolution and function in the context of phylogenetic reconstruction. Morphological analyses place stifftail ducks as part of a large clade of diving ducks that includes the sea ducks (Mergini), Hymenolaimus, Merganetta, and Tachyeres, and possibly the pochards (Aythyini). Molecular analyses, on the other hand, place stifftails far from other diving ducks and suggest, moreover, that stifftails are polyphyletic. Mitochondrial cytochrome b gene sequences of eight stifftail species traditionally supposed to form a clade were compared with each other and with sequences from 50 other anseriform and galliform species. Stifftail ducks are not the sister group of sea ducks but lie outside the typical ducks (Anatinae). Of the four traditional stifftail genera, monophyly of Oxyura and its sister group relationship with Nomonyx are strongly supported. Heteronetta probably is the sister group of that clade, but support is weak. Biziura is not a true stifftail. Within Oxyura, Old World species (O. australis, O. leucocephala, O. mnccoa) appear to form a clade, with New World species (O. jamaicensis, O. vittata) branching basally. Incongruence between molecules and morphology is interpreted to be the result of adaptive specialization and functional convergence in the hind limbs of Biziura and true stifftails. When morphological characters are divided into classes, only hind-limb characters are significantly in conflict with the molecular tree. Likewise, null models of

  3. Data set incongruence and correlated character evolution: an example of functional convergence in the hind-limbs of stifftail diving ducks.

    PubMed

    McCracken, K G; Harshman, J; McClellan, D A; Afton, A D

    1999-12-01

    The unwitting inclusion of convergent characters in phylogenetic estimates poses a serious problem for efforts to recover phylogeny. Convergence is not inscrutable, however, particularly when one group of characters tracks phylogeny and another set tracks adaptive history. In such cases, convergent characters may be correlated with one or a few functional anatomical units and readily identifiable by using comparative methods. Stifftail ducks (Oxyurinae) offer one such opportunity to study correlated character evolution and function in the context of phylogenetic reconstruction. Morphological analyses place stifftail ducks as part of a large clade of diving ducks that includes the sea ducks (Mergini), Hymenolaimus, Merganetta, and Tachyeres, and possibly the pochards (Aythyini). Molecular analyses, on the other hand, place stifftails far from other diving ducks and suggest, moreover, that stifftails are polyphyletic. Mitochondrial cytochrome b gene sequences of eight stifftail species traditionally supposed to form a clade were compared with each other and with sequences from 50 other anseriform and galliform species. Stifftail ducks are not the sister group of sea ducks but lie outside the typical ducks (Anatinae). Of the four traditional stifftail genera, monophyly of Oxyura and its sister group relationship with Nomonyx are strongly supported. Heteronetta probably is the sister group of that clade, but support is weak. Biziura is not a true stifftail. Within Oxyura, Old World species (O. australis, O. leucocephala, O. maccoa) appear to form a clade, with New World species (O. jamaicensis, O. vittata) branching basally. Incongruence between molecules and morphology is interpreted to be the result of adaptive specialization and functional convergence in the hind limbs of Biziura and true stifftails. When morphological characters are divided into classes, only hind-limb characters are significantly in conflict with the molecular tree. Likewise, null models of

  4. Contribution of hind limb flexor muscle afferents to the timing of phase transitions in the cat step cycle.

    PubMed

    Hiebert, G W; Whelan, P J; Prochazka, A; Pearson, K G

    1996-03-01

    1. In this investigation, we tested the hypothesis that muscle spindle afferents signaling the length of hind-leg flexor muscles are involved in terminating extensor activity and initiating flexion during walking. The hip flexor muscle iliopsoas (IP) and the ankle flexors tibialis anterior (TA) and extensor digitorum longus (EDL) were stretched or vibrated at various phases of the step cycle in spontaneously walking decerebrate cats. Changes in electromyogram amplitude, duration, and timing were then examined. The effects of electrically stimulating group I and II afferents in the nerves to TA and EDL also were examined. 2. Stretch of the individual flexor muscles (IP, TA, or EDL) during the stance phase reduced the duration of extensor activity and promoted the onset of flexor burst activity. The contralateral step cycle also was affected by the stretch, the duration of flexor activity being shortened and extensor activity occurring earlier. Therefore, stretch of the flexor muscles during the stance phase reset the locomotor rhythm to flexion ipsilaterally and extension contralaterally. 3. Results of electrically stimulating the afferents from the TA and EDL muscles suggested that different groups of afferents were responsible for the resetting of the step cycle. Stimulation of the TA nerve reset the locomotor step cycle when the stimulus intensity was in the group II range (2-5 xT). By contrast, stimulation of the EDL nerve generated strong resetting of the step cycle in the range of 1.2-1.4 xT, where primarily the group Ia afferents from the muscle spindles would be activated. 4. Vibration of IP or EDL during stance reduced the duration of the extensor activity by similar amounts to that produced by muscle stretch or by electrical stimulation of EDL at group Ia strengths. This suggests that the group Ia afferents from IP and EDL are capable of resetting the locomotor pattern generator. Vibration of TA did not affect the locomotor rhythm. 5. Stretch of IP or

  5. Involvement of spinal α2 -adrenoceptors in prolonged modulation of hind limb withdrawal reflexes following acute noxious stimulation in the anaesthetized rabbit.

    PubMed

    Harris, John

    2016-03-01

    The role of spinal α2 -adrenoceptors in mediating long-lasting modulation of hind limb withdrawal reflexes following acute noxious chemical stimulation of distant heterotopic and local homotopic locations has been investigated in pentobarbitone-anaesthetized rabbits. Reflexes evoked in the ankle extensor muscle medial gastrocnemius (MG) by electrical stimulation of the ipsilateral heel, and reflexes elicited in the ankle flexor tibialis anterior and the knee flexor semitendinosus by stimulation at the base of the ipsilateral toes, could be inhibited for over 1 h after mustard oil (20%) was applied to either the snout or into the contralateral MG. The heel-MG response was also inhibited after applying mustard oil across the plantar metatarsophalangeal joints of the ipsilateral foot, whereas this homotopic stimulus facilitated both flexor responses. Mustard oil also caused a significant pressor effect when applied to any of the three test sites. The selective α2 -adrenoceptor antagonist, RX 821002 (100-300 μg, intrathecally), had no effect on reflexes per se, but did cause a decrease in mean arterial blood pressure. In the presence of the α2 -blocker, inhibitory and facilitatory effects of mustard oil on reflexes were completely abolished. These data imply that long-lasting inhibition of spinal reflexes following acute noxious stimulation of distant locations involves activation of supraspinal noradrenergic pathways, the effects of which are dependent on an intact α2 -adrenoceptor system at the spinal level. These pathways and receptors also appear to be involved in facilitation (sensitization) as well as inhibition of reflexes following a noxious stimulus applied to the same limb.

  6. Combination of anti-ICAM-1 and anti-LFA-1 monoclonal antibody therapy prolongs allograft survival in rat hind-limb transplants.

    PubMed

    Ozer, K; Siemionow, M

    2001-10-01

    Immunosuppressive effects of monoclonal antibodies against adhesion molecules were validated in solid organ transplants. There have been only a few reports on the effect of these antibodies on limb transplantation. In this study, the authors investigated the effects of anti-ICAM-1 and anti-LFA-1 therapy in the rat hind-limb-cremaster transplantation model. Twenty transplantations were performed across a major histocompatibility barrier between Lewis Brown Norway (LBN, RT-1(l+n)) and Lewis (LEW, RT-1(l)) rats in four experimental groups of five animals each. Group 1 animals received only vehicle solution; Groups 2 and 3 received monoclonal antibodies against ICAM-1 and LFA-1, respectively; Group 4 received a combination dose. Treatments were continued for 7 days. Clinical signs of rejection were noted daily, and correlated with in vivo microcirculatory measurements. The activation of adhering leukocytes was significantly lower in rats treated with anti-ICAM-1, anti-LFA-1, and combination than in controls (p < 0.05). Transmigrating leukocytes were also reduced in antibody-treated groups, when compared to the control group (p < 0.05). The mean number of rolling lymphocytes was significantly reduced only in the combination group (p < 0.05). Endothelial edema index, a measure of endothelial swelling, was lowest in the combination group (p < 0.05). The first clinical signs of rejection were noted between the 5(th) and 9(th) days in the control group, on the 9(th) day in the anti-ICAM-1 or anti-LFA-1 groups, and on the 13(th) day with combination therapy. Monoclonal antibodies against LFA-1 or ICAM-1 alone inhibit the activation of leukocytes at the microcirculatory level but do not prolong graft survival. However, the combination of anti-ICAM-1 and anti-LFA-1 monoclonal antibodies significantly prolonged allograft survival in this composite tissue transplantation model.

  7. Pharmacokinetics of Acetaminophen in Hind Limbs Unloaded Mice: A Model System Simulating the Effects of Low Gravity on Astronauts in Space

    NASA Technical Reports Server (NTRS)

    Peterson, Amanda; Risin, Semyon A.; Ramesh, Govindarajan T.; Dasgupta, Amitava; Risin, Diana

    2008-01-01

    The pharmacokinetics (PK) of medications administered to astronauts could be altered by the conditions in Space. Low gravity and free floating (and associated hemodynamic changes) could affect the absorption, distribution, metabolism and excretion of the drugs. Knowledge of these alterations is essential for adjusting the dosage and the regimen of drug administration in astronauts. Acquiring of such knowledge has inherent difficulties due to limited opportunities for experimenting in Space. One of the approaches is to use model systems that simulate some of the Space conditions on Earth. In this study we used hind limbs unloaded mice (HLU) to investigate the possible changes in PK of acetaminophen, a widely used analgesic with high probability of use by astronauts. The HLU is recognized as an appropriate model for simulating the effects of low gravity on hemodynamic parameters. Mice were tail suspended (n = 24) for 24-96 hours prior to introduction of acetaminophen (150 - 300 mg/kg). The drug (in aqueous solution containing 10% ethyl alcohol by volume) was given orally by a gavage procedure and after the administration of acetaminophen mice were additionally suspended for 30 min, 1 and 2 hours. Control mice (n = 24) received the same dose of acetaminophen and were kept freely all the time. Blood specimens were obtained either from retroorbital venous sinuses or from heart. Acetaminophen concentration was measured in plasma by the fluorescent polarization immunoassay and the AxSYM analyzer (Abbott Laboratories). In control mice peak acetaminophen concentration was achieved at 30 min. By 1 hour the concentration decreased to less than 50% of the peak level and at 2 hours the drug was almost undetectable in the serum. HLU for 24 hours significantly altered the acetaminophen pharmacokinetic: at 30 min the acetaminophen concentrations were significantly (both statistically and medically significant) lower than in control mice. The concentrations also reduced less

  8. Protective effects of erdosteine and vitamins C and E combination on ischemia-reperfusion-induced lung oxidative stress and plasma copper and zinc levels in a rat hind limb model.

    PubMed

    Sirmali, Mehmet; Uz, Efkan; Sirmali, Rana; Kilbaş, Aynur; Yilmaz, H Ramazan; Altuntaş, Irfan; Naziroğlu, Mustafa; Delibaş, Namik; Vural, Hüseyin

    2007-07-01

    The aim of this study was to investigate the protective effects of erdosteine and vitamins C and E (VCE) on the lungs after performing hind limb ischemia-reperfusion (I/R) by assessing oxidative stress, plasma copper (Cu), and zinc (Zn) analysis. The animals were divided randomly into four groups as nine rats each as follows: control, I/R, I/R plus erdosteine, and I/R plus VCE combination. I/R period for 60 min was performed on the both hind limbs of all the rats in the groups of I/R, erdosteine with I/R, VCE with I/R allowing 120 min of reperfusion. The animals received orally erdosteine one time in a day and 3 days before I/R in the erdosteine group. In the VCE group, the animals VCE combination received one time in a day and 3 days before I/R, although placebo was given to control and I/R group animals. Lung lipid peroxidation (malondialdehyde [MDA]) level, superoxide dismutase (SOD), and catalase activities were increased, although lung glutathione (GSH) and plasma Zn levels decreased in I/R group in lung tissue compared with the control group. Serum MDA level, creatine kinase, and lactate dehydrogenase activities were increased in I/R group compared with the control. Lung MDA and plasma Zn levels and lung SOD activity were decreased by erdosteine administration, whereas lung GSH levels after I/R increased. The plasma Zn levels and lung SOD activity were decreased by VCE administration, although the plasma Cu and lung GSH levels increased after I/R. In conclusion, erdosteine has an antioxidant role on the values in the rat model, and it has more protective affect than in VCE in attenuating I/R-induced lung injury in rats.

  9. Whole-bone scaling of the avian pelvic limb.

    PubMed

    Doube, Michael; Yen, Stephanie C W; Kłosowski, Michał M; Farke, Andrew A; Hutchinson, John R; Shefelbine, Sandra J

    2012-07-01

    Birds form the largest extant group of bipedal animals and occupy a broad range of body masses, from grams to hundreds of kilograms. Additionally, birds occupy distinct niches of locomotor behaviour, from totally flightless strong runners such as the ratites (moa, kiwi, ostrich) to birds that may walk, dabble on water or fly. We apply a whole-bone approach to investigate allometric scaling trends in the pelvic limb bones (femur, tibiotarsus, tarsometatarsus) from extant and recently extinct birds of greatly different size, and compare scaling between birds in four locomotor groups; flightless, burst-flying, dabbling and flying. We also compare scaling of birds' femoral cross-sectional properties to data previously collected from cats. Scaling exponents were not significantly different between the different locomotor style groups, but elevations of the scaling relationships revealed that dabblers (ducks, geese, swans) have particularly short and slender femora compared with other birds of similar body mass. In common with cats, but less pronounced in birds, the proximal and distal extrema of the bones scaled more strongly than the diaphysis, and in larger birds the diaphysis occupied a smaller proportion of bone length than in smaller birds. Cats and birds have similar femoral cross-sectional area (CSA) for the same body mass, yet birds' bone material is located further from the bone's long axis, leading to higher second and polar moments of area and a greater inferred resistance to bending and twisting. The discrepancy in the relationship between outer diameter to CSA may underlie birds' reputation for having 'light' bones.

  10. Scale Effects between Body Size and Limb Design in Quadrupedal Mammals

    PubMed Central

    Kilbourne, Brandon M.; Hoffman, Louwrens C.

    2013-01-01

    Recently the metabolic cost of swinging the limbs has been found to be much greater than previously thought, raising the possibility that limb rotational inertia influences the energetics of locomotion. Larger mammals have a lower mass-specific cost of transport than smaller mammals. The scaling of the mass-specific cost of transport is partly explained by decreasing stride frequency with increasing body size; however, it is unknown if limb rotational inertia also influences the mass-specific cost of transport. Limb length and inertial properties – limb mass, center of mass (COM) position, moment of inertia, radius of gyration, and natural frequency – were measured in 44 species of terrestrial mammals, spanning eight taxonomic orders. Limb length increases disproportionately with body mass via positive allometry (length ∝ body mass0.40); the positive allometry of limb length may help explain the scaling of the metabolic cost of transport. When scaled against body mass, forelimb inertial properties, apart from mass, scale with positive allometry. Fore- and hindlimb mass scale according to geometric similarity (limb mass ∝ body mass1.0), as do the remaining hindlimb inertial properties. The positive allometry of limb length is largely the result of absolute differences in limb inertial properties between mammalian subgroups. Though likely detrimental to locomotor costs in large mammals, scale effects in limb inertial properties appear to be concomitant with scale effects in sensorimotor control and locomotor ability in terrestrial mammals. Across mammals, the forelimb's potential for angular acceleration scales according to geometric similarity, whereas the hindlimb's potential for angular acceleration scales with positive allometry. PMID:24260117

  11. Scale effects between body size and limb design in quadrupedal mammals.

    PubMed

    Kilbourne, Brandon M; Hoffman, Louwrens C

    2013-01-01

    Recently the metabolic cost of swinging the limbs has been found to be much greater than previously thought, raising the possibility that limb rotational inertia influences the energetics of locomotion. Larger mammals have a lower mass-specific cost of transport than smaller mammals. The scaling of the mass-specific cost of transport is partly explained by decreasing stride frequency with increasing body size; however, it is unknown if limb rotational inertia also influences the mass-specific cost of transport. Limb length and inertial properties--limb mass, center of mass (COM) position, moment of inertia, radius of gyration, and natural frequency--were measured in 44 species of terrestrial mammals, spanning eight taxonomic orders. Limb length increases disproportionately with body mass via positive allometry (length ∝ body mass(0.40)); the positive allometry of limb length may help explain the scaling of the metabolic cost of transport. When scaled against body mass, forelimb inertial properties, apart from mass, scale with positive allometry. Fore- and hindlimb mass scale according to geometric similarity (limb mass ∝ body mass(1.0)), as do the remaining hindlimb inertial properties. The positive allometry of limb length is largely the result of absolute differences in limb inertial properties between mammalian subgroups. Though likely detrimental to locomotor costs in large mammals, scale effects in limb inertial properties appear to be concomitant with scale effects in sensorimotor control and locomotor ability in terrestrial mammals. Across mammals, the forelimb's potential for angular acceleration scales according to geometric similarity, whereas the hindlimb's potential for angular acceleration scales with positive allometry.

  12. Interspecific scaling of the morphology and posture of the limbs during the locomotion of cats (Felidae).

    PubMed

    Day, Lisa M; Jayne, Bruce C

    2007-02-01

    For phylogenetically diverse mammals, ranging from small rodents to large ungulates, the generalization that limb erectness increases with increased size is supported by some size-dependent scaling relationships of appendicular skeletal anatomy as well as a limited number of direct observations of limb posture during locomotion. If size alone is the causal basis for different limb posture, then the erectness of limbs should increase significantly with increased size within a phylogenetically narrow lineage, but such data are sparse. Thus, to better establish the correlation between size and posture of mammalian limbs, we quantified the scaling relationships between mass and limb dimensions and kinematics during walking of nine species within the felid (cat) clade, which has qualitatively similar limb design. We studied the domestic cat, serval, ocelot, lynx, leopard, cheetah, cougar, lion and tiger, which had masses ranging from <4 kg to nearly 200 kg. Apart from variation associated with overall size, the lengths of the appendicular skeletal structures of most of the felid species were morphologically very similar in multivariate space. The kinematics of the limbs were also relatively uniform, and size had little predictive value for limb posture among felid species. Only three out of a total of 24 angular variables at footfall and midstance changed significantly (0.02limbs than smaller species.

  13. A universal scaling relationship between body mass and proximal limb bone dimensions in quadrupedal terrestrial tetrapods

    PubMed Central

    2012-01-01

    Background Body size is intimately related to the physiology and ecology of an organism. Therefore, accurate and consistent body mass estimates are essential for inferring numerous aspects of paleobiology in extinct taxa, and investigating large-scale evolutionary and ecological patterns in the history of life. Scaling relationships between skeletal measurements and body mass in birds and mammals are commonly used to predict body mass in extinct members of these crown clades, but the applicability of these models for predicting mass in more distantly related stem taxa, such as non-avian dinosaurs and non-mammalian synapsids, has been criticized on biomechanical grounds. Here we test the major criticisms of scaling methods for estimating body mass using an extensive dataset of mammalian and non-avian reptilian species derived from individual skeletons with live weights. Results Significant differences in the limb scaling of mammals and reptiles are noted in comparisons of limb proportions and limb length to body mass. Remarkably, however, the relationship between proximal (stylopodial) limb bone circumference and body mass is highly conserved in extant terrestrial mammals and reptiles, in spite of their disparate limb postures, gaits, and phylogenetic histories. As a result, we are able to conclusively reject the main criticisms of scaling methods that question the applicability of a universal scaling equation for estimating body mass in distantly related taxa. Conclusions The conserved nature of the relationship between stylopodial circumference and body mass suggests that the minimum diaphyseal circumference of the major weight-bearing bones is only weakly influenced by the varied forces exerted on the limbs (that is, compression or torsion) and most strongly related to the mass of the animal. Our results, therefore, provide a much-needed, robust, phylogenetically corrected framework for accurate and consistent estimation of body mass in extinct terrestrial

  14. Reliability, agreement, and validity of digital weighing scale with MatScan in limb load measurement.

    PubMed

    Kumar, Senthil N S; Omar, Baharudin; Htwe, Ohnmar; Joseph, Leonard H; Krishnan, Jagannathan; Jafarzedah Esfehani, Ali; Min, Lee L

    2014-01-01

    Limb loading measurements serve as an objective evaluation of asymmetrical weight bearing in the lower limb. Digital weighing scales (DWSs) could be used in clinical settings for measurement of static limb loading. However, ambiguity exists whether limb loading measurements of DWSs are comparable with a standard tool such as MatScan. A cross-sectional study composed of 33 nondisabled participants was conducted to investigate the reliability, agreement, and validity of DWSs with MatScan in static standing. Amounts of weight distribution and plantar pressure on the individual lower limb were measured using two DWSs (A, B) and MatScan during eyes open (EO) and eyes closed (EC) conditions. The results showed that intra- and interrater reliability (3, 1) were excellent (0.94-0.97) within and between DWS A and B. Bland-Altman plot revealed good agreement between DWS and MatScan in EO and EC conditions. The area under the receiver operating characteristic curve was significant and identified as 0.68 (p = 0.01). The measurements obtained with DWSs are valid and in agreement with MatScan measurements. Hence, DWSs could be used interchangeably with MatScan and could provide clinicians an objective measurement of limb loading suitable for clinical settings.

  15. Scaling of Haversian canal surface area to secondary osteon bone volume in ribs and limb bones.

    PubMed

    Skedros, John G; Knight, Alex N; Clark, Gunnar C; Crowder, Christian M; Dominguez, Victoria M; Qiu, Shijing; Mulhern, Dawn M; Donahue, Seth W; Busse, Björn; Hulsey, Brannon I; Zedda, Marco; Sorenson, Scott M

    2013-06-01

    Studies of secondary osteons in ribs have provided a great deal of what is known about remodeling dynamics. Compared with limb bones, ribs are metabolically more active and sensitive to hormonal changes, and receive frequent low-strain loading. Optimization for calcium exchange in rib osteons might be achieved without incurring a significant reduction in safety factor by disproportionally increasing central canal size with increased osteon size (positive allometry). By contrast, greater mechanical loads on limb bones might favor reducing deleterious consequences of intracortical porosity by decreasing osteon canal size with increased osteon size (negative allometry). Evidence of this metabolic/mechanical dichotomy between ribs and limb bones was sought by examining relationships between Haversian canal surface area (BS, osteon Haversian canal perimeter, HC.Pm) and bone volume (BV, osteonal wall area, B.Ar) in a broad size range of mature (quiescent) osteons from adult human limb bones and ribs (modern and medieval) and various adult and subadult non-human limb bones and ribs. Reduced major axis (RMA) and least-squares (LS) regressions of HC.Pm/B.Ar data show that rib and limb osteons cannot be distinguished by dimensional allometry of these parameters. Although four of the five rib groups showed positive allometry in terms of the RMA slopes, nearly 50% of the adult limb bone groups also showed positive allometry when negative allometry was expected. Consequently, our results fail to provide clear evidence that BS/BV scaling reflects a rib versus limb bone dichotomy whereby calcium exchange might be preferentially enhanced in rib osteons.

  16. Functional specialization and ontogenetic scaling of limb anatomy in Alligator mississippiensis

    PubMed Central

    Allen, Vivian; Elsey, Ruth M; Jones, Nicola; Wright, Jordon; Hutchinson, John R

    2010-01-01

    Crocodylians exhibit a fascinating diversity of terrestrial gaits and limb motions that remain poorly described and are of great importance to understanding their natural history and evolution. Their musculoskeletal anatomy is pivotal to this diversity and yet only qualitative studies of muscle-tendon unit anatomy exist. The relative masses and internal architecture (fascicle lengths and physiological cross-sectional areas) of muscles of the pectoral and pelvic limbs of American alligators (Alligator mississippiensis Daudin 1801) were recorded for an ontogenetic series of wild specimens (n = 15, body masses from 0.5 to 60 kg). The data were analysed by reduced major axis regression to determine scaling relationships with body mass. Physiological cross-sectional areas and therefore muscle force-generating capacity were found to be greater in the extensor (anti-gravity) muscles of the pelvic limb than in the pectoral limb, reflecting how crocodylians differ from mammals in having greater loading of the hindlimbs than the forelimbs. Muscle masses and architecture were generally found to scale isometrically with body mass, suggesting an ontogenetic decrease in terrestrial athleticism. This concurs with the findings of previous studies showing ontogenetic decreases in limb bone length and the general scaling principle of a decline of strength : weight ratios with increasing size in animals. Exceptions to isometric scaling found included positive allometry in fascicle length for extensor musculature of both limbs, suggesting an ontogenetic increase in working range interpreted as increasing postural variability – in particular the major hip extensors – the interpretation of which is complicated by previous described ontogenetic increase of moment arms for these muscles. PMID:20148991

  17. Limb-Bone Scaling Indicates Diverse Stance and Gait in Quadrupedal Ornithischian Dinosaurs

    PubMed Central

    Maidment, Susannah C. R.; Linton, Deborah H.; Upchurch, Paul; Barrett, Paul M.

    2012-01-01

    Background The most primitive ornithischian dinosaurs were small bipeds, but quadrupedality evolved three times independently in the clade. The transition to quadrupedality from bipedal ancestors is rare in the history of terrestrial vertebrate evolution, and extant analogues do not exist. Constraints imposed on quadrupedal ornithischians by their ancestral bipedal bauplan remain unexplored, and consequently, debate continues about their stance and gait. For example, it has been proposed that some ornithischians could run, while others consider that none were cursorial. Methodology/Principal Findings Drawing on biomechanical concepts of limb bone scaling and locomotor theory developed for extant taxa, we use the largest dataset of ornithischian postcranial measurements so far compiled to examine stance and gait in quadrupedal ornithischians. Differences in femoral midshaft eccentricity in hadrosaurs and ceratopsids may indicate that hadrosaurs placed their feet on the midline during locomotion, while ceratopsids placed their feet more laterally, under the hips. More robust humeri in the largest ceratopsids relative to smaller taxa may be due to positive allometry in skull size with body mass in ceratopsids, while slender humeri in the largest stegosaurs may be the result of differences in dermal armor distribution within the clade. Hadrosaurs are found to display the most cursorial morphologies of the quadrupedal ornithischian cades, indicating higher locomotor performance than in ceratopsids and thyreophorans. Conclusions/Significance Limb bone scaling indicates that a previously unrealised diversity of stances and gaits were employed by quadrupedal ornithischians despite apparent convergence in limb morphology. Grouping quadrupedal ornithischians together as a single functional group hides this disparity. Differences in limb proportions and scaling are likely due to the possession of display structures such as horns, frills and dermal armor that may have affected

  18. Ontogenetic scaling patterns and functional anatomy of the pelvic limb musculature in emus (Dromaius novaehollandiae)

    PubMed Central

    Main, Russell P.; Hutchinson, John R.

    2014-01-01

    Emus (Dromaius novaehollandiae) are exclusively terrestrial, bipedal and cursorial ratites with some similar biomechanical characteristics to humans. Their growth rates are impressive, as their body mass increases eighty-fold from hatching to adulthood whilst maintaining the same mode of locomotion throughout life. These ontogenetic characteristics stimulate biomechanical questions about the strategies that allow emus to cope with their rapid growth and locomotion, which can be partly addressed via scaling (allometric) analysis of morphology. In this study we have collected pelvic limb anatomical data (muscle architecture, tendon length, tendon mass and bone lengths) and calculated muscle physiological cross sectional area (PCSA) and average tendon cross sectional area from emus across three ontogenetic stages (n = 17, body masses from 3.6 to 42 kg). The data were analysed by reduced major axis regression to determine how these biomechanically relevant aspects of morphology scaled with body mass. Muscle mass and PCSA showed a marked trend towards positive allometry (26 and 27 out of 34 muscles respectively) and fascicle length showed a more mixed scaling pattern. The long tendons of the main digital flexors scaled with positive allometry for all characteristics whilst other tendons demonstrated a less clear scaling pattern. Finally, the two longer bones of the limb (tibiotarsus and tarsometatarsus) also exhibited positive allometry for length, and two others (femur and first phalanx of digit III) had trends towards isometry. These results indicate that emus experience a relative increase in their muscle force-generating capacities, as well as potentially increasing the force-sustaining capacities of their tendons, as they grow. Furthermore, we have clarified anatomical descriptions and provided illustrations of the pelvic limb muscle–tendon units in emus. PMID:25551028

  19. Hinds Community College MSEIP program

    NASA Technical Reports Server (NTRS)

    2005-01-01

    Student Assistant Antoinette Davis (left) of Utica; Carmella Forsythe, 13, of Clinton; Terri Henderson, 14, of Clinton; Tyra Greer, 12, of Port Gibson; and Kala Battle, 14, of Edwards, answer curriculum questions about NASA's Return to Flight mission exhibit at StenniSphere, the visitor center at NASA's Stennis Space Center (SSC) near Bay St. Louis, Miss. The girls were on a field trip to StenniSphere with fellow participants in Hinds Community College's MSEIP (Minority Science Engineering Improvement Program) summer program. MSEIP encourages students to pursue and prepare for careers in science, technology, engineering and math.

  20. Small-scale Structuring of Ellerman Bombs at the Solar Limb

    NASA Astrophysics Data System (ADS)

    Nelson, C. J.; Scullion, E. M.; Doyle, J. G.; Freij, N.; Erdélyi, R.

    2015-01-01

    Ellerman bombs (EBs) have been widely studied in recent years due to their dynamic, explosive nature and apparent links to the underlying photospheric magnetic field implying that they may be formed by magnetic reconnection in the photosphere. Despite a plethora of researches discussing the morphologies of EBs, there has been a limited investigation of how these events appear at the limb, specifically, whether they manifest as vertical extensions away from the disk. In this article, we make use of high-resolution, high-cadence observations of an Active Region at the solar limb, collected by the CRisp Imaging SpectroPolarimeter (CRISP) instrument, to identify EBs and infer their physical properties. The upper atmosphere is also probed using the Solar Dynamic Observatory's Atmospheric Imaging Assembly (SDO/AIA). We analyze 22 EB events evident within these data, finding that 20 appear to follow a parabolic path away from the solar surface at an average speed of 9 km s-1, extending away from their source by 580 km, before retreating back at a similar speed. These results show strong evidence of vertical motions associated with EBs, possibly explaining the dynamical "flaring" (changing in area and intensity) observed in on-disk events. Two in-depth case studies are also presented that highlight the unique dynamical nature of EBs within the lower solar atmosphere. The viewing angle of these observations allows for a direct linkage between these EBs and other small-scale events in the Hα line wings, including a potential flux emergence scenario. The findings presented here suggest that EBs could have a wider-reaching influence on the solar atmosphere than previously thought, as we reveal a direct linkage between EBs and an emerging small-scale loop, and other near-by small-scale explosive events. However, as previous research found, these extensions do not appear to impact upon the Hα line core, and are not observed by the SDO/AIA EUV filters.

  1. SMALL-SCALE STRUCTURING OF ELLERMAN BOMBS AT THE SOLAR LIMB

    SciTech Connect

    Nelson, C. J.; Doyle, J. G.; Scullion, E. M.; Freij, N.; Erdélyi, R.

    2015-01-01

    Ellerman bombs (EBs) have been widely studied in recent years due to their dynamic, explosive nature and apparent links to the underlying photospheric magnetic field implying that they may be formed by magnetic reconnection in the photosphere. Despite a plethora of researches discussing the morphologies of EBs, there has been a limited investigation of how these events appear at the limb, specifically, whether they manifest as vertical extensions away from the disk. In this article, we make use of high-resolution, high-cadence observations of an Active Region at the solar limb, collected by the CRisp Imaging SpectroPolarimeter (CRISP) instrument, to identify EBs and infer their physical properties. The upper atmosphere is also probed using the Solar Dynamic Observatory's Atmospheric Imaging Assembly (SDO/AIA). We analyze 22 EB events evident within these data, finding that 20 appear to follow a parabolic path away from the solar surface at an average speed of 9 km s{sup –1}, extending away from their source by 580 km, before retreating back at a similar speed. These results show strong evidence of vertical motions associated with EBs, possibly explaining the dynamical ''flaring'' (changing in area and intensity) observed in on-disk events. Two in-depth case studies are also presented that highlight the unique dynamical nature of EBs within the lower solar atmosphere. The viewing angle of these observations allows for a direct linkage between these EBs and other small-scale events in the Hα line wings, including a potential flux emergence scenario. The findings presented here suggest that EBs could have a wider-reaching influence on the solar atmosphere than previously thought, as we reveal a direct linkage between EBs and an emerging small-scale loop, and other near-by small-scale explosive events. However, as previous research found, these extensions do not appear to impact upon the Hα line core, and are not observed by the SDO/AIA EUV filters.

  2. Measurement of lower-limb muscle spasticity: intrarater reliability of Modified Modified Ashworth Scale.

    PubMed

    Ghotbi, Nastaran; Nakhostin Ansari, Noureddin; Naghdi, Soofia; Hasson, Scott

    2011-01-01

    The Modified Modified Ashworth Scale (MMAS) is a clinical instrument for measuring spasticity. Few studies have been performed on the reliability of the MMAS. The aim of the present study was to investigate the intrarater reliability of the MMAS for the assessment of spasticity in the lower limb. We conducted a test-retest study on spasticity in the hip adductors, knee extensors, and ankle plantar flexors. Each patient was measured by a hospital-based clinical physiotherapist. Twenty-three patients with stroke or multiple sclerosis (fourteen women, nine men) and a mean +/- standard deviation age of 37.3 +/- 14.1 years participated. The weighted kappa was moderate for the hip adductors (weighted kappa = 0.45, standard error [SE] = 0.16, p = 0.007), good for the knee extensors (weighted kappa = 0.62, SE = 0.12, p < 0.001), and very good for the ankle plantar flexors (weighted kappa = 0.85, SE = 0.05, p < 0.001). The kappa value for overall agreement was very good (weighted kappa = 0.87, SE = 0.03, p < 0.001). The reliability for the ankle plantar flexors was significantly higher than that for the hip adductors. The intrarater reliability of the MMAS in patients with lower-limb muscle spasticity was very good, and it can be used as a measure of spasticity over time.

  3. Kinect One-based biomechanical assessment of upper-limb performance compared to clinical scales in post-stroke patients.

    PubMed

    Scano, Alessandro; Caimmi, Marco; Chiavenna, Andrea; Malosio, Matteo; Tosatti, Lorenzo Molinari

    2015-08-01

    This paper presents a Kinect One sensor-based protocol for the evaluation of the motor-performances of the upper limb of neurological patients during rehabilitative sessions. The assessment provides evaluations of kinematic, dynamic, motor and postural control variables. A pilot study was conducted on three post-stroke neurological patients, comparing Kinect-One biomechanical assessment with the outcomes of some of the most common clinical scales for the evaluation of the upper-limb functionality. Preliminary results indicate coherency between the clinical and instrumental evaluation. Moreover, the Kinect-One assessment seems to provide some complementary quantitative information, consistently integrating the clinical assessment.

  4. Increased SCE levels in Mediterranean Italian buffaloes affected by limb malformation (transversal hemimelia).

    PubMed

    Peretti, V; Ciotola, F; Albarella, S; Restucci, B; Meomartino, L; Ferretti, L; Barbieri, V; Iannuzzi, L

    2008-01-01

    In recent years some buffalo farms in Campania have reported the birth of calves with limb malformation, especially with transversal hemimelia. We investigated 20 Mediterranean Italian buffaloes (8 males and 12 females) from one day to six months of age, of which 10 were affected by transversal hemimelia (group 1) and 10 were healthy controls (group 2). The following clinical and radiological patterns were observed in the malformed animals: hind limbs amputated, the right amputated off the second tarsus bones and the left amputated off the proximal epiphysis metatarsus, and the right thoracic limb hypoplasic (1 female); left hind limb amputated off the proximal epiphysis metatarsus (2 females and 1 male); left hind limb amputated off the third tarsus bones (1 female); left hind limb amputated off the tibia (1 female and 1 male); left hind limb amputated off the distal epiphysis metatarsus (1 female); left hind limb amputated off the first phalanx (1 male); right hind limb amputated off the proximal epiphysis metatarsus (1 male). In their malformed limbs all the animals presented more or less developed outlines of claws. The mean rate of SCE/cell in animals with transversal hemimelia was 8.80 +/- 3.19, that of the controls 6.61 +/- 2.73. The difference was statistically significant (P < 0.001).

  5. Large-scale Extreme-Ultraviolet Disturbances Associated with a Limb Coronal Mass Ejection

    NASA Astrophysics Data System (ADS)

    Dai, Y.; Auchère, F.; Vial, J.-C.; Tang, Y. H.; Zong, W. G.

    2010-01-01

    We present composite observations of a coronal mass ejection (CME) and the associated large-scale extreme-ultraviolet (EUV) disturbances on 2007 December 31 by the Extreme-ultraviolet Imager (EUVI) and COR1 coronagraph on board the recent Solar Terrestrial Relations Observatory mission. For this limb event, the EUV disturbances exhibit some typical characteristics of EUV Imaging Telescope waves: (1) in the 195 Å bandpass, diffuse brightenings are observed propagating oppositely away from the flare site with a velocity of ~260 km s-1, leaving dimmings behind; (2) when the brightenings encounter the boundary of a polar coronal hole, they stop there to form a stationary front. Multi-temperature analysis of the propagating EUV disturbances favors a heating process over a density enhancement in the disturbance region. Furthermore, the EUVI-COR1 composite display shows unambiguously that the propagation of the diffuse brightenings coincides with a large lateral expansion of the CME, which consequently results in a double-loop-structured CME leading edge. Based on these observational facts, we suggest that the wave-like EUV disturbances are a result of magnetic reconfiguration related to the CME liftoff rather than true waves in the corona. Reconnections between the expanding CME magnetic field lines and surrounding quiet-Sun magnetic loops account for the propagating diffuse brightenings; dimmings appear behind them as a consequence of volume expansion. X-ray and radio data provide us with complementary evidence.

  6. Relationships among the Y balance test, Berg Balance Scale, and lower limb strength in middle-aged and older females

    PubMed Central

    Lee, Dong-Kyu; Kang, Min-Hyeok; Lee, Tae-Sik; Oh, Jae-Seop

    2015-01-01

    Background: Older females have less dynamic postural control and muscle strength than do middle-aged females. Aging-related strength losses may limit balancing performance. Objective: The purpose of this study was to investigate the ability of the Y Balance Test (YBT) and lower limb strength to discriminate between females in 2 age groups, the relationship between YBT distance and the Berg Balance Scale (BBS), and the degree to which performance on YBT distance is related to lower limb strength in middle-aged and older females. Method: The 40 healthy, independently active females were divided into 2 groups: older and middle-aged. The participants underwent measurements of YBT distance using the YBT, maximal muscular strength of the lower limbs using a handheld dynamometer, and the BBS. Results: The YBT distance in 3 directions and lower limb muscle strength for both lower limbs were significantly lower in the older adults than in the middle-aged group. A moderate correlation but insignificant correlation was found between the YBT composite distance and the BBS score. In the older females, YBT distance was significantly positively correlated with strength of the knee flexor and hip abductor. In the middle-aged group, YBT distance was significantly positively correlated with strength of the knee flexor and hip extensor. Conclusions: Performance on the YBT was influenced by the strength of lower limb. We suggested that YBT can be used to alternative as a measurement of dynamic balance. Proper training programs for older people could include not only strengthening exercises but also YBT performance to improve balance. PMID:26039033

  7. Cellular basis of differential limb growth in postnatal gray short-tailed opossums (Monodelphis domestica).

    PubMed

    Beiriger, Anastasia; Sears, Karen E

    2014-06-01

    While growth has been studied extensively in invertebrates, the mechanisms by which it is controlled in vertebrates, particularly in mammals, remain poorly understood. In this study, we investigate the cellular basis of differential limb growth in postnatal Monodelphis domestica, the gray short-tailed opossum, to gain insights into the mechanisms regulating mammalian growth. Opossums are an ideal model for the study of growth because they are born with relatively large, well-developed forelimbs and small hind limbs that must "catch up" to the forelimb before the animal reaches adulthood. Postnatal Days 1-17 were identified as a key period of growth for the hind limbs, during which they undergo accelerated development and nearly quadruple in length. Histology performed on fore- and hind limbs from this period indicates a higher rate of cellular differentiation in the long bones of the hind limbs. Immunohistochemical assays indicate that cellular proliferation is also occurring at a significantly greater rate in the long bones of the hind limb at 6 days after birth. Taken together, these results suggest that a faster rate of cellular proliferation and differentiation in the long bones of the hind limb relative to those of the forelimb generates a period of accelerated growth through which the adult limb phenotype of M. domestica is achieved. Assays for gene expression suggest that the molecular basis of this differential growth differs from that previously identified for differential pre-natal growth in opossum fore- and hind limbs.

  8. Goal Attainment Scaling in Individuals with Upper Limb Spasticity Post Stroke.

    PubMed

    Eftekhar, Parvin; Mochizuki, George; Dutta, Tilak; Richardson, Denyse; Brooks, Dina

    2016-12-01

    Focusing on rehabilitation goals is an effective approach for improving function in individuals with spasticity after stroke. The objectives of this study were to examine and map goals of post-stroke individuals with spasticity using the Goal Attainment Scale (GAS) and International Classification of Functioning, Disability and Health (ICF), and to evaluate the impact of botulinum toxin A (BoNTA) on occupational performance based on the type of rehabilitation goals. Thirty-one patients were recruited from an outpatient spasticity management clinic. Each patient set one goal, was injected with BoNTA in their spastic upper limb muscles and received standard rehabilitation services twice a week for four weeks. Twenty-seven participants achieved the expected level, and four exceeded the expected level of their rehabilitation goals. Fifty-five percent of the goals were related to Activity/Participation, and 45% of the goals were categorized in the Body Structures and Function domain of the ICF. Fifteen goals focused on positioning, while 16 goals focused on (independent) activities of daily living (ADL/IADL). Both the positioning and ADL/IADL groups experienced a reduction in MAS following the administration of BoNTA. The positioning group was older and more impaired. Mapping goals to ICF identifies specific targets for intervention, establishes a common language within the interdisciplinary team and contextualizes the ways disability impacts goals. This study is limited by a relatively small sample size and absence of a functional measure. Further studies can explore the development of goal/item banks to advance the use of GAS for spasticity management. Copyright © 2016 John Wiley & Sons, Ltd.

  9. 4. EAST ELEVATION OF HINDS PLANT. NOTE BUTTRESSING AS ON ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. EAST ELEVATION OF HINDS PLANT. NOTE BUTTRESSING AS ON EAGLE MOUNTAIN FOR SEISMIC REINFORCEMENT. - Hinds Pump Plant, East of Joshua Tree National Monument, 5 miles north of Route 10, Hayfield, Riverside County, CA

  10. 8. MAIN INLET FROM FILTER GALLERY AND CANAL INTO HINDS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. MAIN INLET FROM FILTER GALLERY AND CANAL INTO HINDS PLANT. VIEW LOOKING DUE WEST OF HINDS COMPLEX IN BACKGROUND OF SAND FILTERS. - Hinds Pump Plant, East of Joshua Tree National Monument, 5 miles north of Route 10, Hayfield, Riverside County, CA

  11. Hind, John R (1823-1895)

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    English astronomer, discovered in 1852 a small nebula in Taurus which, in 1861, was found by HEINRICH D'ARREST to have disappeared. By the end of the year, D'Arrest and OTTO WILHELM STRUVE had recovered it. Hind's variable nebula, as it came to be called, demonstrated that at least some nebulae were small, as nothing larger than a light year in dimension can disappear in a year. The nebula is a ...

  12. Suppression of morphogenesis in embryonic mouse limbs exposed in vitro to excess gravity

    NASA Technical Reports Server (NTRS)

    Duke, Jackie C.

    1983-01-01

    The effect of excess gravity on in vitro mammalian limb chondrogenesis is studied. Limb buds from mice of various gestational stages were exposed to excess gravity (2.6G) using a culture centrifuge. Both forelimbs and hind limbs were cultured, and the development of various limb elements was scored after four to six days. The 2.6G force significantly depressed the development of limb elements when applied during the teratogen-sensitive period of chondrogenesis.

  13. Non-linear scaling of a musculoskeletal model of the lower limb using statistical shape models.

    PubMed

    Nolte, Daniel; Tsang, Chui Kit; Zhang, Kai Yu; Ding, Ziyun; Kedgley, Angela E; Bull, Anthony M J

    2016-10-03

    Accurate muscle geometry for musculoskeletal models is important to enable accurate subject-specific simulations. Commonly, linear scaling is used to obtain individualised muscle geometry. More advanced methods include non-linear scaling using segmented bone surfaces and manual or semi-automatic digitisation of muscle paths from medical images. In this study, a new scaling method combining non-linear scaling with reconstructions of bone surfaces using statistical shape modelling is presented. Statistical Shape Models (SSMs) of femur and tibia/fibula were used to reconstruct bone surfaces of nine subjects. Reference models were created by morphing manually digitised muscle paths to mean shapes of the SSMs using non-linear transformations and inter-subject variability was calculated. Subject-specific models of muscle attachment and via points were created from three reference models. The accuracy was evaluated by calculating the differences between the scaled and manually digitised models. The points defining the muscle paths showed large inter-subject variability at the thigh and shank - up to 26mm; this was found to limit the accuracy of all studied scaling methods. Errors for the subject-specific muscle point reconstructions of the thigh could be decreased by 9% to 20% by using the non-linear scaling compared to a typical linear scaling method. We conclude that the proposed non-linear scaling method is more accurate than linear scaling methods. Thus, when combined with the ability to reconstruct bone surfaces from incomplete or scattered geometry data using statistical shape models our proposed method is an alternative to linear scaling methods.

  14. Global-scale Observations of the Limb and Disk (GOLD): From Simulations to Observations

    NASA Astrophysics Data System (ADS)

    Eastes, R.; McClintock, W. E.; Anderson, D. N.; Burns, A. G.; England, S.; Solomon, S. C.; Jones, S.; Talaat, E. R.; Aksnes, A.; Andersson, L.; Codrescu, M.; Daniell, R. E.; Harvey, J.; Krywonos, A.; Lumpe, J. D., Jr.; Richmond, A. D.; Rusch, D. W.; Siegmund, O.; Strickland, D. J.; Woods, T. N.; Budzien, S. A.; Dymond, K.; Eparvier, F. G.; Lieberman, R. S.; Martinis, C. R.; Oberheide, J.

    2015-12-01

    The GOLD mission is scheduled to launch a far ultraviolet (FUV), imaging spectrograph into geostationary orbit over the Americas in late 2017. Laboratory observations by an optical breadboard of the GOLD imager show performance that matches the expected performance of the flight instrument and that exceeds the requirements. Excellent agreement is seen between these laboratory observations and model calculations of the N2 LBH spectrum. Such laboratory data, as well as model simulations of the expected observations, will be used in the development and testing of the data processing to be used during flight. Simulated observations of increasing realism are being developed. These simulations are a valuable tool for developing and understanding GOLD's observations of the neutral temperatures on the disk and limb, neutral composition (O/N2 density) on the disk, molecular oxygen density profile and the nighttime ionosphere at low latitudes. Simulations will also be used test observing plans and software for data reduction. The contract for accommodation of the GOLD instrument on the SES-14 satellite was signed in April 2015. That made GOLD the first NASA mission of opportunity to establish a contract for commercial launch into geostationary orbit. The host satellite, a Eurostar 3000 built by Airbus Defence & Space for SES, will use electric propulsion for transfer to geostationary orbit. Securing a contract for hosting has allowed the interfaces to the spacecraft to be defined and the instrument design to be completed. This presentation describes the current status of the GOLD instrument, the future development of the mission, and the simulations of the GOLD measurements.

  15. How do the substrate reaction forces acting on a gecko's limbs respond to inclines?

    NASA Astrophysics Data System (ADS)

    Wang, Zhouyi; Dai, Zhendong; Li, Wei; Ji, Aihong; Wang, Wenbao

    2015-02-01

    Locomotion is an essential character of animals, and excellent moving ability results from the delicate sensing of the substrate reaction forces (SRF) acting on body and modulating the behavior to adapt the motion requirement. The inclined substrates present in habitats pose a number of functional challenges to locomotion. In order to effectively overcome these challenges, climbing geckos execute complex and accurate movements that involve both the front and hind limbs. Few studies have examined gecko's SRF on steeper inclines of greater than 90°. To reveal how the SRFs acting on the front and hind limbs respond to angle incline changes, we obtained detailed measurements of the three-dimensional SRFs acting on the individual limbs of the tokay gecko while it climbed on an inclined angle of 0-180°. The fore-aft forces acting on the front and hind limbs show opposite trends on inverted inclines of greater than 120°, indicating propulsion mechanism changes in response to inclines. When the incline angles change, the forces exerted in the normal and fore-aft directions by gecko's front and hind limbs are reassigned to take full advantage of limbs' different roles in overcoming resistance and in propelling locomotion. This also ensures that weight acts in the angle range between the forces generated by the front and hind limbs. The change in the distribution of SRF with a change in the incline angle is directly linked to the favorable trade-off between locomotive maneuverability and stability.

  16. 5. HINDS PUMPING FLOOR FROM WEST END TOP OF UNIT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. HINDS PUMPING FLOOR FROM WEST END TOP OF UNIT #9 (LENS STOPPED DOWN ALL THE WAY FOR DEPTH OF FIELD ENHANCEMENT). - Hinds Pump Plant, East of Joshua Tree National Monument, 5 miles north of Route 10, Hayfield, Riverside County, CA

  17. Ontogeny of joint mechanics in squirrel monkeys (Saimiri boliviensis): functional implications for mammalian limb growth and locomotor development

    PubMed Central

    Young, Jesse W.

    2009-01-01

    Summary Juvenile animals must often compete against adults for common resources, keep pace during group travel and evade common predators, despite reduced body size and an immature musculoskeletal system. Previous morphometric studies of a diverse array of mammals, including jack rabbits, cats and capuchin monkeys, have identified growth-related changes in anatomy, such as negative allometry of limb muscle mechanical advantage, which should theoretically permit young mammals to overcome such ontogenetic limits on performance. However, it is important to evaluate the potential impact of such `compensatory' growth trajectories within the context of developmental changes in locomotor behavior. I used standard kinematic and kinetic techniques to investigate the ontogenetic scaling of joint postures, substrate reaction forces, joint load arm lengths and external joint moments in an ontogenetic sample of squirrel monkeys (Saimiri boliviensis). Results indicated that young squirrel monkeys were frequently able to limit forelimb and hind limb joint loading via a combination of changes in limb posture and limb force distribution, potentially compensating for limited muscularity at younger ages. These results complement previous morphometric studies and suggest that immature mammals may utilize a combination of behavioral and anatomical mechanisms to mitigate ontogenetic limits on locomotor performance. However, ontogenetic changes in joint posture, not limb length per se, explained most of the variation in load arm lengths and joint loading in growing squirrel monkeys, indicating the importance of incorporating both anatomical and performance measures when studying the ontogeny of limb joint mechanics. PMID:19411552

  18. Artificial Limbs

    MedlinePlus

    ... you are missing an arm or leg, an artificial limb can sometimes replace it. The device, which is ... activities such as walking, eating, or dressing. Some artificial limbs let you function nearly as well as before.

  19. LIMB Demonstration Project Extension

    SciTech Connect

    Not Available

    1988-03-15

    The basic goal of the Limestone Injection Multistage Burner (LIMB) demonstration is to extend LIMB technology development to a full-scale application on a representative wall-fired utility boiler. The successful retrofit of LIMB to an existing boiler is expected to demonstrate that (a) reductions of 50 percent or greater in SO{sub x} and NO{sub x} emissions can be achieved at a fraction of the cost of add-on FGD systems, (b) boiler reliability, operability, and steam production can be maintained at levels existing prior to LIMB retrofit, and (c) technical difficulties attributable to LIMB operation, such as additional slagging and fouling, changes in ash disposal requirements, and an increased particulate load, can be resolved in a cost-effective manner. The primary fuel to be used will be an Ohio bituminous coal having a nominal sulfur content of 3 percent or greater.

  20. LIMB Demonstration Project Extension

    SciTech Connect

    Not Available

    1988-09-15

    The basic goal of the Limestone Injection Multistage Burner (LIMB) demonstration is to extend LIMB technology development to a full-scale application on a representative wall-fired utility boiler. The successful retrofit of LIMB to an existing boiler is expected to demonstrate that (a) reductions of 50 percent or greater in SO and NO emissions can be achieved at a fraction of the cost of add-on FGD systems, (b) boiler reliability, operability, and steam production can be maintained at levels existing prior to LIMB retrofit, and (c) technical difficulties attributable to LIMB operation, such as additional slagging and fouling, changes in ash disposal requirements, and an increased particulate load, can be resolved in a cost-effective manner. The primary fuel to be used will be an Ohio bituminous coal having a nominal sulfur content of 3 percent or greater.

  1. Global-scale Observations of the Limb and Disk (GOLD): Hosted Payload Accommodation on a Commercial Satellite

    NASA Astrophysics Data System (ADS)

    Lankton, M.; Eastes, R.; McClintock, W. E.; Pang, R.; Caffrey, R.; Krywonos, A.

    2013-12-01

    The Global-Scale Observations of the Limb and Disk (GOLD) mission will perform unprecedented imaging of the Earth's thermosphere and ionosphere (TI) system from geostationary (GEO) orbit. Flying as a hosted payload on a commercial communications satellite, GOLD takes advantage of the resource margins available in the early years of the commercial mission's planned 15-year life. This hosted payload approach is a pathfinder for cost-effective NASA science missions. The affordable ride to GEO makes it possible for an Explorer-class Mission of Opportunity to perform Far UltraViolet (FUV) imaging of nearly a complete hemisphere on a 30-minute cadence. This global-scale, high cadence imaging will enable GOLD to distinguish between spatial and temporal variations in the TI system caused by geomagnetic storms, variations in solar EUV, and forcing from the lower atmosphere. The most significant difference between developing instrumentation for a NASA-owned mission and accomplishing the same task for a commercial satellite is that communications satellites are procured on a faster schedule - 24 to 36 months from satellite contract to launch - than the instrument development. GOLD has partnered with SES Government Solutions (SES-GS), the comsat mission owner-operator, to define instrument interfaces and requirements that will be included in the eventual Request for Proposal to candidate spacecraft vendors. SES-GS launches 3 to 4 missions per year, which allows the GOLD-SES-GS partnership to match the instrument's launch readiness date with a suitable mission. In addition to making geostationary orbit accessible to a science instrument at relatively low cost, commercial communications satellites provides a host platform with very high reliability and long life, easy access to continuous high-speed data downlink and near-real-time data delivery, and stable pointing. SES-GS operates their satellite from established Telemetry, Tracking and Control (TT&C) centers. The GOLD Science

  2. Differences in the timing of prechondrogenic limb development in mammals: the marsupial-placental dichotomy resolved.

    PubMed

    Sears, Karen E

    2009-08-01

    In contrast to placentals, marsupials are born with forelimbs that are greatly developmentally advanced relative to their hind limbs. Despite significant interest, we still do not know why this is the case, or how this difference is achieved developmentally. Studies of prechondrogenic and chondrogenic limbs have supported the traditional hypothesis that marsupial forelimb development is accelerated in response to the functional requirements of the newborn's crawl to the teat. However, limb ossification studies have concluded that, rather than the forelimb being accelerated, hind limb development is delayed. By increasing the taxonomic coverage and number of prechondrogenic events relative to previous studies, and combining traditional phylogenetic analyses of event sequences with novel analyses of relative developmental rates, this study demonstrates that the timing of limb development in marsupials is more complex than commonly thought. The marsupial phenotype was derived through two independent evolutionary changes in developmental rate: (1) an acceleration of the forelimb's first appearance and (2) a delay of hind limb development from the bud stage onward. Surprisingly, this study also provides some support for an evolutionary acceleration of the marsupial hind limb's first appearance. Further study is needed on the developmental and genetic mechanisms driving these major evolutionary transitions.

  3. Limb Loss

    MedlinePlus

    ... limb. Learning how to use it takes time. Physical therapy can help you adapt. Recovery from the loss of a limb can be hard. Sadness, anger, and frustration are common. If you are having a tough time, talk to your doctor. Treatment with medicine or counseling can help.

  4. HD 38451 - J. R. Hind's star that changed colour

    NASA Astrophysics Data System (ADS)

    Warner, Brian; Sneden, Christopher

    1988-09-01

    In 1851, John Russell Hind announced that a star previously observed by him to be very red had become bluish white in color. It is shown that this star, HD 38451, is a ninth magnitude shell star which presumably was ejecting a shell when Hind first observed it. From high dispersion coude spectra, low dispersion IUE spectra, and ground-based photometry, HD 38451 is found to be a normal A21V shell star. Its current values of E(B-V) of about 0.14 is probably caused by interstellar rather than circumstellar reddening. There remains a problem to reconcile the large amount of reddening present when Hind first observed the star with its evidently small diminution in visual brightness at that time.

  5. Boots on horses: limb protection or hyperflexion training aids in the showjumping horse.

    PubMed

    Murphy, Jack

    2008-01-01

    Showjumping riders regularly employ various schooling strategies to control the horse's jump stride kinematics (JSK). Strategies include plyometric training regimes with fences of different heights and widths set at specific distances. Gymnastic grids teach the horse to jump cleanly. Rapping, once used almost routinely, is no longer in vogue. However, the use of performance enhancing (PE) boots on the distal hind limbs to alter equine JSK has become popular. There are two broad categories of PE boots: weighted and pressure. Some riders use so-called weighted boots on the horses' hind limbs during training and in competition to improve the jump stride. The application of so-called pressure boots may be little more than an adaptation of this technique. It appears that the PE boots induce hyperflexion of the hind limbs and incline the horse to jump fences cleanly. In the absence of scientific appraisal, it is unclear if such boots are acceptable and innovative training aids within equitation.

  6. Intraspecific scaling of the minimum metabolic cost of transport in leghorn chickens (Gallus gallus domesticus): links with limb kinematics, morphometrics and posture

    PubMed Central

    Rose, Kayleigh A.; Nudds, Robert L.; Codd, Jonathan R.

    2015-01-01

    ABSTRACT The minimum metabolic cost of transport (CoTmin; J kg−1 m−1) scales negatively with increasing body mass (∝Mb−1/3) across species from a wide range of taxa associated with marked differences in body plan. At the intraspecific level, or between closely related species, however, CoTmin does not always scale with Mb. Similarity in physiology, dynamics of movement, skeletal geometry and posture between closely related individuals is thought to be responsible for this phenomenon, despite the fact that energetic, kinematic and morphometric data are rarely collected together. We examined the relationship between these integrated components of locomotion in leghorn chickens (Gallus gallus domesticus) selectively bred for large and bantam (miniature) varieties. Interspecific allometry predicts a CoTmin ∼16% greater in bantams compared with the larger variety. However, despite 38% and 23% differences in Mb and leg length, respectively, the two varieties shared an identical walking CoTmin, independent of speed and equal to the allometric prediction derived from interspecific data for the larger variety. Furthermore, the two varieties moved with dynamic similarity and shared geometrically similar appendicular and axial skeletons. Hip height, however, did not scale geometrically and the smaller variety had more erect limbs, contrary to interspecific scaling trends. The lower than predicted CoTmin in bantams for their Mb was associated with both the more erect posture and a lower cost per stride (J kg−1 stride−1). Therefore, our findings are consistent with the notion that a more erect limb is associated with a lower CoTmin and with the previous assumption that similarity in skeletal shape, inherently linked to walking dynamics, is associated with similarity in CoTmin. PMID:25657211

  7. Conditional effect of selenium on the mammalian hind gut microbiota

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selenium (Se) status is linked to cancer risk in humans and other mammals. Because Se is used by certain microbial species which contain selenoproteins, and because hind gut microfloral composition is linked to cancer development, we proposed that supranutritional Se could reduce tumorigenisis by af...

  8. The Impact of Prophylactic Fasciotomy Following Porcine (Sus scrofa) Hind Limb Ischemia/Reperfusion Injury

    DTIC Science & Technology

    2012-03-23

    the 14-day survival period to calculate the composite physiologic model of recovery ( PMR ). Necropsy was performed for evaluation of nerve and...muscle histology. Results: In hemorrhage alone, according to the PMR the recovery was 94+/-28%, 63+/- 37% and 55+/-44% at 0, 3 and 6 hours of ischemia...hours. , , . v w and compared to baseline to create the Physiologic Model of Recovery ( PMR ). On day 14, necropsy was performed and

  9. The spatial organization of central sensitization of hind limb flexor reflexes in the decerebrated, spinalized rabbit.

    PubMed

    Clarke, R W; Harris, J

    2001-01-01

    This study was designed to investigate the relationship between the location of a noxious stimulus and the magnitude and duration of the plastic effects induced by that stimulus in withdrawal reflexes acting about the knee and the ankle, in rabbits. Reflexes were evoked in the nerves to the anterior tibial and semitendinosus flexor muscles by electrical stimulation at the toes. Repetitive, high intensity electrical stimulation of nerve trunks (sural, medial gastrocnemius, superficial peroneal, tibial, 100 pulses, 20 V, 1 ms at 0.5 Hz) was generally found to be a poor method for inducing central sensitization in these flexor reflexes. 'Natural' noxious stimulation induced more reliable enhancement of both reflexes. Mechanical (clamp) or chemical (mustard oil) stimulation of the heel induced prolonged (median duration >30 min) increases in reflexes to both muscles. Mechanical (clamp and superficial pinch) or chemical (mustard oil) stimulation of the toes, and injection of bradykinin into the gastrocnemius muscles or into the soft tissues of the sole of the foot, also led to enhancement of both reflexes, with the median duration of potentiation between 7 and 30 min. The effects obtained from deep tissue stimulation were generally weaker than those obtained after stimulation of superficial structures. These data show that there were no major differences in the effects obtained from the heel vs the toes, or between the two reflexes. It appears that the spatial organization of the spinal mechanisms underlying central sensitization of flexor withdrawal reflexes is rather more crudely drawn than that pertaining to the reflexes themselves. Furthermore, the data indicate that in the present preparation, afferents from deep tissues are no more effective in generating central sensitization than those from superficial structures.

  10. Reloading partly recovers bone mineral density and mechanical properties in hind limb unloaded rats

    NASA Astrophysics Data System (ADS)

    Zhao, Fan; Li, Dijie; Arfat, Yasir; Chen, Zhihao; Liu, Zonglin; Lin, Yu; Ding, Chong; Sun, Yulong; Hu, Lifang; Shang, Peng; Qian, Airong

    2014-12-01

    Skeletal unloading results in decreased bone formation and bone mass. During long-term space flight, the decreased bone mass is impossible to fully recover. Therefore, it is necessary to develop the effective countermeasures to prevent spaceflight-induced bone loss. Hindlimb Unloading (HLU) simulates effects of weightlessness and is utilized extensively to examine the response of musculoskeletal systems to certain aspects of space flight. The purpose of this study is to investigate the effects of a 4-week HLU in rats and subsequent reloading on the bone mineral density (BMD) and mechanical properties of load-bearing bones. After HLU for 4 weeks, the rats were then subjected to reloading for 1 week, 2 weeks and 3 weeks, and then the BMD of the femur, tibia and lumbar spine in rats were assessed by dual energy X-ray absorptiometry (DXA) every week. The mechanical properties of the femur were determined by three-point bending test. Dry bone and bone ash of femur were obtained through Oven-Drying method and were weighed respectively. Serum alkaline phosphatase (ALP) and serum calcium were examined through ELISA and Atomic Absorption Spectrometry. The results showed that 4 weeks of HLU significantly decreased body weight of rats and reloading for 1 week, 2 weeks or 3 weeks did not recover the weight loss induced by HLU. However, after 2 weeks of reloading, BMD of femur and tibia of HLU rats partly recovered (+10.4%, +2.3%). After 3 weeks of reloading, the reduction of BMD, energy absorption, bone mass and mechanical properties of bone induced by HLU recovered to some extent. The changes in serum ALP and serum calcium induced by HLU were also recovered after reloading. Our results indicate that a short period of reloading could not completely recover bone after a period of unloading, thus some interventions such as mechanical vibration or pharmaceuticals are necessary to help bone recovery.

  11. Effect of Endotoxin on Oxygen Consumption By a Flow-Controlled Canine Hind-Limb Preparation

    DTIC Science & Technology

    1980-10-01

    a reduction in the cardiac metabolic units of the periphery, (3) the red bloodq output and a widening of the central arteriovenous cell or...explained readily by the reduction in takeoff of the profunda femoris artery; the internal + SNum ber Volume 88 Effect of endotoxin on oxygen

  12. Morphological changes in neurons of the hind limb reflex arc during long term immobilization

    NASA Technical Reports Server (NTRS)

    Tkachenko, Z. Y.

    1980-01-01

    Twelve adult rabbits were immobilized for 9 to 31 days, followed by histological study of the nerve processes of lumbar vertebra 7 and sacral vertebra 1, the sciatic nerve and the motor endings of the thigh muscles. In the spinal ganglia, dystrophic changes of increasing severity with immobilization time were found, including pericellular edema, vacuolized neuroplasm, pycnotic changes, cytolysis and destruction. Chromatophilic matter decreased and was partly bleached, and amitotic division occurred. A portion of the sciatic nerve fibers were argentophilic, and some fragmentary decomposition occurred. Considerable dystrophic changes occurred in the motor nerve endings.

  13. Capillary-to-fiber ratio of hind limb muscles in the male Syrian golden hamster.

    PubMed

    Swisher, Anne K; Alway, Stephen E; Yeater, Rachel

    2004-04-01

    The hamster has been the accepted model of emphysema since the 1970s, demonstrating disease-related effects on respiratory skeletal muscle. However, there is scant information available about the model's ability to replicate the peripheral skeletal muscle changes seen in human disease, such as alterations in capillarity. The present study described the capillary-to-fiber ratio (C/F) of normal hamster plantaris, gastrocnemius, and soleus muscles in eight animals. C/F was 1.72 +/- 0.38 for plantaris, 1.95 +/- 0.40 for gastrocnemius, and 2.22 +/- 0.43 for soleus. C/F of soleus was significantly greater (P < 0.01) than plantaris. The C/F of hamster hindlimb muscles varies from those seen in rat species, and having baseline data on hamsters makes it possible to determine the effects of emphysema on C/F in this model.

  14. Cellular proliferation in the skin of X-rayed newt limbs (with a note on x-ray-induced limb regression)

    SciTech Connect

    Wertz, R.L.

    1982-07-01

    Left hind limbs, including the pelvis, of adult newts (Notophthalmus viridescens) were locally irradiated with a dose of x-rays that inhibited regeneration (2,000 R). This x-ray dose and other doses (700-2,000 R) capable of inhibiting limb regeneration also cause limb regression prior to amputation. Before limb regression occurred, there was a latent period of 3 to 6 weeks. Limb regression was characterized by necrotic wasting and resorption of distal elements. The degree of loss was variable and dependent upon dosage. After this further degenerative changes were not noted. Proliferation of epidermal cells was examined 4 days after irradiation prior to limb regression or after x-ray-induced degeneration of the limbs had ended. Proliferative activity in x-rayed limbs was also compared at various stages of contralateral control limb regeneration. Limbs examined after x-ray-induced limb regression had ended showed levels of (/sup 3/H)-thymidine incorporation into DNA comparable to normal epidermis. In contrast, limbs examined 4 days after irradiation had lower levels of DNA synthesis (P much less than 0.01). Amputation of limbs in both groups caused an increase in DNA synthesis (P much less than 0.01). Histological examination showed that cellular proliferation was associated primarily with the epidermis. These results indicate that epidermal cell proliferation was not resistant to x-rays. However, levels of normal cell division were observed after amputation of after cessation of x-ray-induced limb regression.

  15. A possible function of the preference for hind nipples in prairie voles (Microtus ochrogaster).

    PubMed

    McGuire, B

    2001-12-01

    Prairie vole pups (Microtus ochrogaster) in laboratory cages prefer hind nipples. In this research, the author observed 8 litters of prairie voles in a seminatural environment to confirm the preference for hind nipples and to determine if young on hind nipples were groomed more frequently or dislodged less frequently than were young on other nipples. Prairie vole pups in seminatural environments preferred hind nipples; this preference was illustrated by the progressive use of more anterior nipples only as litter size increased and by the reluctance of pups to voluntarily release their hold on hind nipples. Maternal grooming of young did not vary with suckling location. Prairie vole young on hind nipples, however, were dislodged less frequently than were young on other nipples. Less frequent dislodgment from hind nipples during maternal movements may play a role in the preference for hind nipples in prairie voles.

  16. Edge detection of red hind grouper vocalizations in the littorals

    NASA Astrophysics Data System (ADS)

    Matthews, Cameron A.; Beaujean, Pierre-Philippe

    2016-05-01

    Littoral regions typically present to passive sensors as a high noise acoustic environment, particularly with respect to port and harbor regions where tidal variation, often characterized as pink, mixes with reverberation from on-shore business and commercial shipping, often characterized as white. Some fish in these regions, in particular epiphenalius Guttatus or more commonly the red hind grouper, emit relatively narrowband tones in low frequencies to communicate with other fish in such regions. The impact of anthropogenic noise sources on the red Hind and other fish is a topical area of interest for wildlife fisheries, private sportsmen and military offices that is not considered here; the fact that fish species continue to populate and communicate in these regions in the presence of high noise content lends some study to the signal content and modeling of a potential biologically inspired receiver structure.

  17. Ubx Regulates Differential Enlargement and Diversification of Insect Hind Legs

    PubMed Central

    Mahfooz, Najmus; Turchyn, Nataliya; Mihajlovic, Michelle; Hrycaj, Steven; Popadić, Aleksandar

    2007-01-01

    Differential enlargement of hind (T3) legs represents one of the hallmarks of insect evolution. However, the actual mechanism(s) responsible are yet to be determined. To address this issue, we have now studied the molecular basis of T3 leg enlargement in Oncopeltus fasciatus (milkweed bug) and Acheta domesticus (house cricket). In Oncopeltus, the T3 tibia displays a moderate increase in size, whereas in Acheta, the T3 femur, tibia, and tarsus are all greatly enlarged. Here, we show that the hox gene Ultrabithorax (Ubx) is expressed in the enlarged segments of hind legs. Furthermore, we demonstrate that depletion of Ubx during embryogenesis has a primary effect in T3 legs and causes shortening of leg segments that are enlarged in a wild type. This result shows that Ubx is regulating the differential growth and enlargement of T3 legs in both Oncopeltus and Acheta. The emerging view suggests that Ubx was co-opted for a novel role in regulating leg growth and that the transcriptional modification of its expression may be a universal mechanism for the evolutionary diversification of insect hind legs. PMID:17848997

  18. Hind Right Approach Pancreaticoduodenectomy: From Skill to Indications

    PubMed Central

    Georgescu, Stefan; Ursulescu, Corina

    2014-01-01

    Background. Pancreaticoduodenectomy is the potentially curative treatment for malignant and several benign conditions of the pancreatic head and periampullary region. While performing pancreaticoduodenectomy, early neck division may be impossible or inadequate in case of hepatic artery anatomic variants, suspected involvement of the superior mesenteric vessels, intraductal papillary mucinous neoplasm, and pancreatic head bleeding pseudoaneurysm. Our work aims to highlight a particular hind right approach pancreaticoduodenectomy in selected indications and assess the preliminary results. Methods. We describe our early hind right approach to the retropancreatic vasculature during pancreaticoduodenectomy by mesopancreas dissection before any pancreatic or digestive transection. Results. We used this approach in 52 patients. Thirty-two had hepatic artery anatomic variant and 2 had bleeding pancreatic head pseudoaneurysm. The hepatic artery variant was preserved in all cases out of 2 in which arterial reconstruction was performed. In nine patients with intraductal papillary mucinous neoplasms the pancreaticoduodenectomy was extended to the body in 6 and totalized in 3 patients. Seven patients with adenocarcinoma involving the portomesenteric axis required venous resection and reconstruction. Conclusions. Early hind right approach is advocated in selected cases of pancreaticoduodenectomy to improve locoregional vascular control and determine, safely and early, whether there is mesopancreas involvement. PMID:25221601

  19. 5-AZA-2'-DEOXYCYTIDINE INDUCED CYTOTOXICITY AND LONG BONE REDUCTION DEFECTS IN THE MURINE LIMB

    EPA Science Inventory

    The antineoplastic drug 5-aza-2'-deoxycytidine (dAZA) is a DNA hypomethylating agent that can be used to induce hind limb phocomelia in the offspring of CD-1 Swiss Webster mice. Previously, our laboratory investigated the possibility that dAZA induced alterations in gene express...

  20. Improved decoding of limb-state feedback from natural sensors.

    PubMed

    Wagenaar, J B; Ventura, V; Weber, D J

    2009-01-01

    Limb state feedback is of great importance for achieving stable and adaptive control of FES neuroprostheses. A natural way to determine limb state is to measure and decode the activity of primary afferent neurons in the limb. The feasibility of doing so has been demonstrated by [1] and [2]. Despite positive results, some drawbacks in these works are associated with the application of reverse regression techniques for decoding the afferent neuronal signals. Decoding methods that are based on direct regression are now favored over reverse regression for decoding neural responses in higher regions in the central nervous system [3]. In this paper, we apply a direct regression approach to decode the movement of the hind limb of a cat from a population of primary afferent neurons. We show that this approach is more principled, more efficient, and more generalizable than reverse regression.

  1. Postnatal allometry of the skeleton in Tupaia glis (Scandentia: Tupaiidae) and Galea musteloides (Rodentia: Caviidae)--a test of the three-segment limb hypothesis.

    PubMed

    Schilling, Nadja; Petrovitch, Alexander

    2006-01-01

    During the evolution of therian mammals, the two-segmented, sprawled tetrapod limbs were transformed into three-segmented limbs in parasagittal zig-zag configuration (three-segment limb hypothesis). As a consequence, the functional correspondence of limb segments has changed (now: scapula to thigh, upper arm to shank, fore arm plus hand to foot). Therefore, the scapula was taken into account in the current study of the postnatal growth of the postcranial skeleton in two small mammalian species (Tupaia glis, Galea musteloides). Comparisons were made between the functionally equivalent elements and not in the traditional way between serially homologous segments. This study presents a test of the three-segment limb hypothesis which predicts a greater ontogenetic congruence in the functionally equivalent elements in fore and hind limbs than in the serially homologous elements. A growth sequence, with decreasing regression coefficients from proximal to distal, was observed in both species under study. This proximo-distal growth sequence is assumed to be ancestral in the ontogeny of eutherian mammals. Different reproductive modes have evolved within eutherian mammals. To test the influence of different life histories on ontogenetic scaling during postnatal growth, one species with altricial juveniles (Tupaia glis) assumed to be the ancestral mode of development for eutherians and one species with derived, precocial young (Galea musteloides) were selected. The growth series covered postnatal development from the first successive steps with a lifted belly to the adult locomotory pattern; thus, functionally equivalent developmental stages were compared. The higher number of allometrically positive or isometrically growing segments in the altricial mammalian species was interpreted as a remnant of the fast growth period in the nest without great locomotor demands, and the clearly negative allometry in nearly all segments in the precocial young was interpreted as a response

  2. How well can interannual to decadal-scale variability in stratospheric ozone and water vapor be quantified using limb-based satellite measurements?

    NASA Astrophysics Data System (ADS)

    Davis, S. M.; Rosenlof, K. H.; Hurst, D. F.; Hassler, B.; Read, W. G.

    2015-12-01

    Vertical profiles of ozone and humidity from the upper troposphere to stratosphere have been retrieved from a number of limb sounding and solar occultation satellite instruments since the 1980's. In particular, measurements from the SAGE instruments, UARS MLS, UARS HALOE, and most recently Aura MLS, have provided overlapping data since 1984. In order to quantify interannual- to decadal-scale variability in water vapor and ozone, it is necessary to have a uniform and homogenous record over the period of interest. With this in mind, we merged the aforementioned satellite measurements to create the Stratospheric Water and Ozone Satellite Homogenized (SWOOSH) data set, which contains vertically resolved zonal-mean (2.5°) monthly-mean water vapor and ozone concentration at levels covering the stratosphere. In this presentation, we describe the process of merging the satellite data sets, which involves adjusting the data to a reference measurement using offsets calculated from coincident observations taken during instrument overlap periods. Uncertainties associated with individual measurement precision, geophysical variability, and the merging process are quantified and compared to one another. We show that while the SWOOSH data can be used to quantify interannual variability, quantifying long-term trends in SWOOSH is complicated by the various sources of uncertainty, as well as by potential drifts of individual instruments. The issue of satellite-derived trends is discussed in relation to the long-term record of balloon-borne frostpoint hygrometer measurements from Boulder, CO.

  3. Stereotaxic Device for Optical Imaging of Mice Hind Feet

    PubMed Central

    Cole, Richard; Hoffman, Timothy; Smith, Jason; Herron, Bruce

    2013-01-01

    Imaging of in vivo model systems, especially mouse models, has revolutionized our understanding of normal and pathological developments. However, mice present several challenges for imaging. They are living and therefore breathing organisms with a fast heart rate (>500 beat/min), which necessitates the need for restraints and positioning controls that do not compromise their normal physiology. We present here a device that immobilizes the rear legs of a mouse while retaining the ability to position both the hind feet and legs for reproducible imaging deep below the skin's surface. The device is highly adjustable to accommodate mice, 5 weeks of age and older. The function of this device is demonstrated by imaging the vasculature ∼250 μm beneath the skin in the hind leg. Whereas the overall dimensions are for a motorized stage (Märzhäuser Wetzlar GmbH, Wetzlar, Germany), minor modifications would allow it to be customized for use with most commercially available stages that accept an insert. PMID:23997660

  4. Propulsive forces of mudskipper fins and salamander limbs during terrestrial locomotion: implications for the invasion of land.

    PubMed

    Kawano, Sandy M; Blob, Richard W

    2013-08-01

    The invasion of land was a pivotal event in vertebrate evolution that was associated with major appendicular modifications. Although fossils indicate that the evolution of fundamentally limb-like appendages likely occurred in aquatic environments, the functional consequences of using early digited limbs, rather than fins, for terrestrial propulsion have had little empirical investigation. Paleontological and experimental analyses both have led to the proposal of an early origin of "hind limb-driven" locomotion among tetrapods or their ancestors. However, the retention of a pectoral appendage that had already developed terrestrial adaptations has been proposed for some taxa, and few data are available from extant functional models that can provide a foundation for evaluating the relative contributions of pectoral and pelvic appendages to terrestrial support among early stem tetrapods. To examine these aspects of vertebrate locomotor evolution during the invasion of land, we measured three-dimensional ground reaction forces (GRFs) produced by isolated pectoral fins of mudskipper fishes (Periophthalmus barbarus) during terrestrial crutching, and compared these to isolated walking footfalls by the forelimbs and hind limbs of tiger salamanders (Ambystoma tigrinum), a species with subequally-sized limbs that facilitate comparisons to early tetrapods. Pectoral appendages of salamanders and mudskippers exhibited numerous differences in GRFs. Compared with salamander forelimbs, isolated fins of mudskippers bear lower vertical magnitudes of GRFs (as a proportion of body weight), and had GRFs that were oriented more medially. Comparing the salamanders' forelimbs and hind limbs, although the peak net GRF occurs later in stance for the forelimb, both limbs experience nearly identical mediolateral and vertical components of GRF, suggesting comparable contributions to support. Thus, forelimbs could also have played a significant locomotor role among basal tetrapods that had limbs

  5. Effects of Ibuprofen and High-Voltage Electric Stimulation on Acute Edema Formation After Blunt Trauma to Limbs of Rats

    PubMed Central

    Dolan, Michael G; Graves, Paul; Nakazawa, Chika; Delano, Teresa; Hutson, Alan; Mendel, Frank C

    2005-01-01

    Context: Ibuprofen is widely used to manage pain and inflammation after orthopaedic trauma, but its effect on acute swelling has not been investigated. Cathodal high-voltage pulsed current (CHVPC) at 120 pulses per second and 90% of visible motor threshold is known to curb edema formation after blunt trauma to the hind limbs of rats. Objective: To examine the effects of ibuprofen, continuous CHVPC, and simultaneous ibuprofen and CHVPC on acute edema formation after blunt trauma to the hind limbs of rats. Design: Randomized, parallel-group, repeated-measures design. Setting: Laboratory animal facility. Participants: A total of 21 3-month-old Zucker Lean rats (mass = 288 ± 55 g) were studied. Intervention(s): We assessed the effects of ibuprofen, continuous CHVPC, and simultaneous ibuprofen and CHVPC on acute edema formation after blunt trauma to the hind limbs of rats. Main Outcome Measure(s): Limb volumes were measured immediately before and after trauma and every 30 minutes over the 4 hours of the experiment. Results: Volumes of treated limbs of all 3 experimental groups were smaller (P < .05) than those of untreated limbs, but no treatment was more effective than another. Conclusions: Ibuprofen, CHVPC, and simultaneous ibuprofen and CHVPC effectively curbed edema after blunt injury by roughly 50% relative to untreated but similarly injured control limbs of rats. PMID:15970957

  6. A comparison of the moment arms of pelvic limb muscles in horses bred for acceleration (Quarter Horse) and endurance (Arab).

    PubMed

    Crook, T C; Cruickshank, S E; McGowan, C M; Stubbs, N; Wilson, A M; Hodson-Tole, E; Payne, R C

    2010-07-01

    Selective breeding for performance has resulted in distinct breeds of horse, such as the Quarter Horse (bred for acceleration) and the Arab (bred for endurance). Rapid acceleration, seen during Quarter Horse racing, requires fast powerful muscular contraction and the generation of large joint torques, particularly by the hind limb muscles. This study compared hind limb moment arm lengths in the Quarter Horse and Arab. We hypothesized that Quarter Horse hind limb extensor muscles would have longer moment arms when compared to the Arab, conferring a greater potential for torque generation at the hip, stifle and tarsus during limb extension. Six Quarter Horse and six Arab hind limbs were dissected to determine muscle moment arm lengths for the following muscles: gluteus medius, biceps femoris, semitendinosus, vastus lateralis, gastrocnemius (medialis and lateralis) and tibialis cranialis. The moment arms of biceps femoris (acting at the hip) and gastrocnemius lateralis (acting at the stifle) were significantly longer in the Quarter Horse, although the length of the remaining muscle moment arms were similar in both breeds of horse. All the Quarter Horse muscles were capable of generating greater muscle moments owing to their greater physiological cross-sectional area (PCSA) and therefore greater isometric force potential, which suggests that PCSA is a better determinant of muscle torque than moment arm length in these two breeds of horse. With the exception of gastrocnemius and tibialis cranialis, the observed muscle fascicle length to moment arm ratio (MFL : MA ratio) was greater for the Arab horse muscles. It appears that the Arab muscles have the potential to operate at slower velocities of contraction and hence generate greater force outputs when compared to the Quarter Horse muscles working over a similar range of joint motion; this would indicate that Arab hind limb muscles are optimized to function at maximum economy rather than maximum power output.

  7. Population characteristics of a recovering US Virgin Islands red hind spawning aggregation following protection

    PubMed Central

    Nemeth, Richard S.

    2006-01-01

    Many species of groupers form spawning aggregations, dramatic events where 100s to 1000s of individuals gather annually at specific locations for reproduction. Spawning aggregations are often targeted by local fishermen, making them extremely vulnerable to over fishing. The Red Hind Bank Marine Conservation District located in St. Thomas, United States Virgin Islands, was closed seasonally in 1990 and closed permanently in 1999 to protect an important red hind Epinephelus guttatus spawning site. This study provides some of the first information on the population response of a spawning aggregation located within a marine protected area. Tag-and-release fishing and fish transects were used to evaluate population characteristics and habitat utilization patterns of a red hind spawning aggregation between 1999 and 2004. Compared with studies conducted before the permanent closure, the average size of red hind increased mostly during the seasonal closure period (10 cm over 12 yr), but the maximum total length of male red hind increased by nearly 7 cm following permanent closure. Average density and biomass of spawning red hind increased by over 60% following permanent closure whereas maximum spawning density more than doubled. Information from tag returns indicated that red hind departed the protected area following spawning and migrated 6 to 33 km to a ca. 500 km2 area. Protection of the spawning aggregation site may have also contributed to an overall increase in the size of red hind caught in the commercial fishery, thus increasing the value of the grouper fishery for local fishermen. PMID:16612415

  8. Optimizing the use of Limb Tourniquets in Tactical Combat Casualty Care: TCCC Guidelines Change 14-02

    DTIC Science & Technology

    2014-02-01

    Sebesta JA, Blackbourne LH, Herbert GS, Kauvar DS, Baer DG, Walters TJ, Mullenix PS, Holcomb JB, 31 st Combat Support Hospital Research Group...K, Dixon P, Cowart J, Spencer J, Rasmussen TE. Hemorrhagic shock worsens neuromuscular recovery in a porcine model of hind limb vascular injury and

  9. Lymph pump mechanics in the rabbit hind leg.

    PubMed

    Ikomi, F; Schmid-Schönbein, G W

    1996-07-01

    The mechanisms that govern fluid uptake by the initial lymphatics and adjustment of lymph flow rates remain to a large degree uncertain. The aim of this study was to examine how passive tissue movement contributes to lymph flow rates. Lymph fluid was collected via a cannula inserted into one of the popliteal prenodal lymphatics in the rabbit hind leg. Lymph flow rates were measured during periodic whole leg rotation and controlled oscillatory massage of the dorsal skin of the foot. Without whole leg rotation, lymph flow remained at low values (< 0.01 ml/h). Introduction of whole leg passive rotation caused a frequency-dependent increase in lymph flow rates, which were increased linearly with the log of frequency between 0.03 and 1.0 Hz. Local skin massage in the region of the initial lymphatics also led to a similar increase of lymph flow rates dependent on frequency as well as amplitude of skin displacement. Lymph flow rates during local skin massage reached a comparable order of magnitude regardless of whether the animal was alive or the heart had been arrested, suggesting that local lymph flow rates can be adjusted by periodic tissue motion independently of capillary fluid filtration pressures. The results indicate that periodic expansion and compression of initial lymphatics provide a mechanism for lymph pumping.

  10. Cholesterol metabolism: the main pathway acting downstream of cytochrome P450 oxidoreductase in skeletal development of the limb.

    PubMed

    Schmidt, Katy; Hughes, Catherine; Chudek, J A; Goodyear, Simon R; Aspden, Richard M; Talbot, Richard; Gundersen, Thomas E; Blomhoff, Rune; Henderson, Colin; Wolf, C Roland; Tickle, Cheryll

    2009-05-01

    Cytochrome P450 oxidoreductase (POR) is the obligate electron donor for all microsomal cytochrome P450 enzymes, which catalyze the metabolism of a wide spectrum of xenobiotic and endobiotic compounds. Point mutations in POR have been found recently in patients with Antley-Bixler-like syndrome, which includes limb skeletal defects. In order to study P450 function during limb and skeletal development, we deleted POR specifically in mouse limb bud mesenchyme. Forelimbs and hind limbs in conditional knockout (CKO) mice were short with thin skeletal elements and fused joints. POR deletion occurred earlier in forelimbs than in hind limbs, leading additionally to soft tissue syndactyly and loss of wrist elements and phalanges due to changes in growth, cell death, and skeletal segmentation. Transcriptional analysis of E12.5 mouse forelimb buds demonstrated the expression of P450s involved in retinoic acid, cholesterol, and arachidonic acid metabolism. Biochemical analysis of CKO limbs confirmed retinoic acid excess. In CKO limbs, expression of genes throughout the whole cholesterol biosynthetic pathway was upregulated, and cholesterol deficiency can explain most aspects of the phenotype. Thus, cellular POR-dependent cholesterol synthesis is essential during limb and skeletal development. Modulation of P450 activity could contribute to susceptibility of the embryo and developing organs to teratogenesis.

  11. Skeletal limb abnormalities

    MedlinePlus

    ... medlineplus.gov/ency/article/003170.htm Skeletal limb abnormalities To use the sharing features on this page, please enable JavaScript. Skeletal limb abnormalities refers to a variety of bone structure problems ...

  12. Critical Limb Ischemia (CLI)

    MedlinePlus

    ... High blood pressure Family history of vascular disease Warning Signs You may have critical limb ischemia if ... blood flow to the limb. Other treatments include laser atherectomy, where small bits of plaque are vaporized ...

  13. Earth's Dynamo: Fore- and Hind- casting Limits from a Variational Data Assimilation Approach

    NASA Astrophysics Data System (ADS)

    Dimitrova, L. L.; Egbert, G. D.; Kuang, W.; Tangborn, A.

    2010-12-01

    In the last decade, fully 3-D, nonlinear numerical dynamo models have allowed for the study of many geomagnetic field features. As the ultimate goal of geodynamo simulations is to explain the features of the real geomagnetic field, variational data assimilation (DA) techniques, in which observations are combined with the underlying dynamical principles governing the system, are a logical next step. A variational approach to DA allows inputs (e.g., initial and boundary data, and forcing) to be adjusted to simultaneously fit dynamical equations and observational data by minimizing a cost functional. The increased resolution and accuracy of geomagnetic field models and observations in recent years can be used to, on one hand, improve estimates of the geodynamo state in earlier years and, on the other hand, to produce better forecasts. Consequently, of interest is the time scales on which such fore- and hind- predictions are appropriate. Recently, Hullot et al. [2010] used a series of perturbed numerical dynamo simulations to estimate a time limit for predictability (time for forecast errors to grow to 100 nT) of 50-70 years for the geodynamo. We present our ongoing effort to develop modern variational DA methods (based on the representers, potentially allowing for weak constraint DA) for the Modular Scalable Self-consistent Three-dimensional (MoSST) geodynamo simulator. An implementation of variational DA requires developing tangent linear (TL) and adjoint (ADJ) codes for the nonlinear forcing and the three different time stepping schemes. The adjoint of the numerical time-stepping schemes is calculated in terms of adjoints of the discrete spatial operators. Because the linear parts of these operators are explicitly formed matrices, adjoints of these spatial operators are essentially matrix transposes. The non-linear terms, which must be linearized around a background state, require more care. The TL and the adjoint can be furthermore used to characterize (1) the

  14. Permanent antibiotic impregnated intramedullary nail in diabetic limb salvage: a case report and literature review.

    PubMed

    Woods, Jason B; Lowery, Nicholas J; Burns, Patrick R

    2012-01-01

    Managing complications after attempted hind foot and ankle arthrodesis with intramedullary nail fixation is a challenge. This situation becomes more problematic in the patient with diabetes mellitus and multiple comorbidities. Infection and subsequent osteomyelitis can be a devastating, limb threatening complication associated with these procedures. The surgeon must manage both the infectious process and the skeletal instability concurrently. This article provides a literature review and detailed management strategies for a modified technique of employing antibiotic impregnated polymethylmethacrylate-coated intramedullary nailing.

  15. A comparative study of trabecular bone mass distribution in cursorial and non-cursorial limb joints.

    PubMed

    Chirchir, Habiba

    2015-05-01

    Skeletal design among cursorial animals is a compromise between a stable body that can withstand locomotor stress and a light design that is energetically inexpensive to grow, maintain, and move. Cursors have been hypothesized to reduce distal musculoskeletal mass to maintain a balance between safety and energetic cost due to an exponential increase in energetic demand observed during the oscillation of the distal limb. Additionally, experimental research shows that the cortical bone in distal limbs experiences higher strains and remodeling rates, apparently maintaining lower mass at the expense of a smaller safety factor. This study tests the hypothesis that the trabecular bone mass in the distal limb epiphyses of cursors is relatively lower than that in the proximal limb epiphyses to minimize the energetic cost of moving the limb. This study utilized peripheral quantitative computed tomography scanning to measure the trabecular mass in the lower and upper limb epiphyses of hominids, cercopithecines, and felids that are considered cursorial and non-cursorial. One-way ANOVA with Tukey post hoc corrections was used to test for significant differences in trabecular mass across limb epiphyses. The results indicate that overall, both cursors and non-cursors exhibit varied trabecular mass in limb epiphyses and, in certain instances, conform to a proximal-distal decrease in mass irrespective of cursoriality. Specifically, hominid and cercopithecine hind limb epiphyses exhibit a proximal-distal decrease in mass irrespective of cursorial adaptations. These results suggest that cursorial mammals employ other energy saving mechanisms to minimize energy costs during running.

  16. Regeneration of limb joints in the axolotl (Ambystoma mexicanum).

    PubMed

    Lee, Jangwoo; Gardiner, David M

    2012-01-01

    In spite of numerous investigations of regenerating salamander limbs, little attention has been paid to the details of how joints are reformed. An understanding of the process and mechanisms of joint regeneration in this model system for tetrapod limb regeneration would provide insights into developing novel therapies for inducing joint regeneration in humans. To this end, we have used the axolotl (Mexican Salamander) model of limb regeneration to describe the morphology and the expression patterns of marker genes during joint regeneration in response to limb amputation. These data are consistent with the hypothesis that the mechanisms of joint formation whether it be development or regeneration are conserved. We also have determined that defects in the epiphyseal region of both forelimbs and hind limbs in the axolotl are regenerated only when the defect is small. As is the case with defects in the diaphysis, there is a critical size above which the endogenous regenerative response is not sufficient to regenerate the joint. This non-regenerative response in an animal that has the ability to regenerate perfectly provides the opportunity to screen for the signaling pathways to induce regeneration of articular cartilage and joints.

  17. Accuracy and precision of equine gait event detection during walking with limb and trunk mounted inertial sensors.

    PubMed

    Olsen, Emil; Andersen, Pia Haubro; Pfau, Thilo

    2012-01-01

    The increased variations of temporal gait events when pathology is present are good candidate features for objective diagnostic tests. We hypothesised that the gait events hoof-on/off and stance can be detected accurately and precisely using features from trunk and distal limb-mounted Inertial Measurement Units (IMUs). Four IMUs were mounted on the distal limb and five IMUs were attached to the skin over the dorsal spinous processes at the withers, fourth lumbar vertebrae and sacrum as well as left and right tuber coxae. IMU data were synchronised to a force plate array and a motion capture system. Accuracy (bias) and precision (SD of bias) was calculated to compare force plate and IMU timings for gait events. Data were collected from seven horses. One hundred and twenty three (123) front limb steps were analysed; hoof-on was detected with a bias (SD) of -7 (23) ms, hoof-off with 0.7 (37) ms and front limb stance with -0.02 (37) ms. A total of 119 hind limb steps were analysed; hoof-on was found with a bias (SD) of -4 (25) ms, hoof-off with 6 (21) ms and hind limb stance with 0.2 (28) ms. IMUs mounted on the distal limbs and sacrum can detect gait events accurately and precisely.

  18. Critical limb ischemia in association with Charcot neuroarthropathy: complex endovascular therapy for limb salvage.

    PubMed

    Palena, Luis Mariano; Brocco, Enrico; Manzi, Marco

    2014-02-01

    Charcot neuroarthropathy is a low-incidence complication of diabetic foot and is associated with ankle and hind foot deformity. Patients who have not developed deep ulcers are managed with offloading and supportive bracing or orthopedic arthrodesis. In patients who have developed ulcers and severe ankle instability and deformity, below-the-knee amputation is often indicated, especially when deformity and cutaneous involvement result in osteomyelitis. Ischemic association has not been described but can be present as a part of peripheral arterial disease in the diabetic population. In this extreme and advanced stage of combined neuroischemic diabetic foot disease, revascularization strategies can support surgical and orthopedic therapy, thus preventing osteomyelitis and leading to limb and foot salvage.

  19. Critical Limb Ischemia in Association with Charcot Neuroarthropathy: Complex Endovascular Therapy for Limb Salvage

    SciTech Connect

    Palena, Luis Mariano; Brocco, Enrico; Manzi, Marco

    2013-05-09

    Charcot neuroarthropathy is a low-incidence complication of diabetic foot and is associated with ankle and hind foot deformity. Patients who have not developed deep ulcers are managed with offloading and supportive bracing or orthopedic arthrodesis. In patients who have developed ulcers and severe ankle instability and deformity, below-the-knee amputation is often indicated, especially when deformity and cutaneous involvement result in osteomyelitis. Ischemic association has not been described but can be present as a part of peripheral arterial disease in the diabetic population. In this extreme and advanced stage of combined neuroischemic diabetic foot disease, revascularization strategies can support surgical and orthopedic therapy, thus preventing osteomyelitis and leading to limb and foot salvage.

  20. Artificial insemination following observational versus electronic methods of estrus detection in red deer hinds (Cervus elephus).

    PubMed

    Bowers, S D; Brown, C G; Strauch, T A; Gandy, B S; Neuendorff, D A; Randel, R D; Willard, S T

    2004-08-01

    The objectives were to determine the efficacy of the HeatWatch (HW) electronic estrus detection system for monitoring behavioral estrus (including duration and intensity) in red deer hinds and to evaluate pregnancy rate to AI after detected estrus. Red deer hinds (Cervus elephus; n = 50) were allocated into two treatment groups: AI following synchronization (CIDR/PMSG) and observed estrus (induced estrus group: IE; n = 25) or AI following the detection of natural estrus (NE; n = 25) without hormonal treatment. Hinds were fitted with two HeatWatch (HW) electronic estrus detection transmitters, one above the tail (bottom) and one between the tuber coxae of the pelvic girdle (top), and visual observations for mounting activity began with the aid of young sterile red deer stags (18 months old) fitted with marking harnesses. Hinds in both groups were inseminated (10-12h after observed estrus) with frozen-thawed red deer semen using a transvaginal/cervical AI approach. Following a 26-day period of AI, hinds were placed with a mature fertile stag for an additional 30-day natural breeding period. Pregnancy diagnosis was performed 57 and 86 days after the start of AI. While the hinds were housed with the young stags, 82% were detected in estrus by visual appraisal of stag crayon marks, but only 32% of these were detected by HW. In contrast, in the hinds housed with the mature stag, 93% detected in estrus by crayon marks were also detected by HW. The top HW transmitter consistently recorded more mounts (P < 0.05) than the bottom transmitter. The pregnancy rate was numerically better in IE versus NE hinds (42% versus 29%, P > 0.10). In summary, there were no differences (P > 0.10) in the intensity (number) or duration of mounts (detected by HW) during estrus in IE versus NE hinds, and HW was most effective in detecting estrus in the presence of a heavier, mature stag versus a younger stag. When used in combination with transvaginal AI, an overall first-service pregnancy rate

  1. Passive Exercise of the Hind Limbs after Complete Thoracic Transection of the Spinal Cord Promotes Cortical Reorganization

    PubMed Central

    Knudsen, Eric B.; Shumsky, Jed; Moxon, Karen A.

    2013-01-01

    Physical exercise promotes neural plasticity in the brain of healthy subjects and modulates pathophysiological neural plasticity after sensorimotor loss, but the mechanisms of this action are not fully understood. After spinal cord injury, cortical reorganization can be maximized by exercising the non-affected body or the residual functions of the affected body. However, exercise per se also produces systemic changes – such as increased cardiovascular fitness, improved circulation and neuroendocrine changes – that have a great impact on brain function and plasticity. It is therefore possible that passive exercise therapies typically applied below the level of the lesion in patients with spinal cord injury could put the brain in a more plastic state and promote cortical reorganization. To directly test this hypothesis, we applied passive hindlimb bike exercise after complete thoracic transection of the spinal cord in adult rats. Using western blot analysis, we found that the level of proteins associated with plasticity – specifically ADCY1 and BDNF – increased in the somatosensory cortex of transected animals that received passive bike exercise compared to transected animals that received sham exercise. Using electrophysiological techniques, we then verified that neurons in the deafferented hindlimb cortex increased their responsiveness to tactile stimuli delivered to the forelimb in transected animals that received passive bike exercise compared to transected animals that received sham exercise. Passive exercise below the level of the lesion, therefore, promotes cortical reorganization after spinal cord injury, uncovering a brain-body interaction that does not rely on intact sensorimotor pathways connecting the exercised body parts and the brain. PMID:23349859

  2. Correlative Imaging of the Murine Hind Limb Vasculature and Muscle Tissue by MicroCT and Light Microscopy

    PubMed Central

    Schaad, Laura; Hlushchuk, Ruslan; Barré, Sébastien; Gianni-Barrera, Roberto; Haberthür, David; Banfi, Andrea; Djonov, Valentin

    2017-01-01

    A detailed vascular visualization and adequate quantification is essential for the proper assessment of novel angiomodulating strategies. Here, we introduce an ex vivo micro-computed tomography (microCT)-based imaging approach for the 3D visualization of the entire vasculature down to the capillary level and rapid estimation of the vascular volume and vessel size distribution. After perfusion with μAngiofil®, a novel polymerizing contrast agent, low- and high-resolution scans (voxel side length: 2.58–0.66 μm) of the entire vasculature were acquired. Based on the microCT data, sites of interest were defined and samples further processed for correlative morphology. The solidified, autofluorescent μAngiofil® remained in the vasculature and allowed co-registering of the histological sections with the corresponding microCT-stack. The perfusion efficiency of μAngiofil® was validated based on lectin-stained histological sections: 98 ± 0.5% of the blood vessels were μAngiofil®-positive, whereas 93 ± 2.6% were lectin-positive. By applying this approach we analyzed the angiogenesis induced by the cell-based delivery of a controlled VEGF dose. Vascular density increased by 426% mainly through the augmentation of medium-sized vessels (20–40 μm). The introduced correlative and quantitative imaging approach is highly reproducible and allows a detailed 3D characterization of the vasculature and muscle tissue. Combined with histology, a broad range of complementary structural information can be obtained. PMID:28169309

  3. Ontogenetic changes in limb bone structural proportions in mountain gorillas (Gorilla beringei beringei).

    PubMed

    Ruff, Christopher B; Burgess, M Loring; Bromage, Timothy G; Mudakikwa, Antoine; McFarlin, Shannon C

    2013-12-01

    Behavioral studies indicate that adult mountain gorillas (Gorilla beringei) are the most terrestrial of all nonhuman hominoids, but that infant mountain gorillas are much more arboreal. Here we examine ontogenetic changes in diaphyseal strength and length of the femur, tibia, humerus, radius, and ulna in 30 Virunga mountain gorillas, including 18 immature specimens and 12 adults. Comparisons are also made with 14 adult western lowland gorillas (Gorilla gorilla gorilla), which are known to be more arboreal than adult mountain gorillas. Infant mountain gorillas have significantly stronger forelimbs relative to hind limbs than older juveniles and adults, but are nonsignificantly different from western lowland gorilla adults. The change in inter-limb strength proportions is abrupt at about two years of age, corresponding to the documented transition to committed terrestrial quadrupedalism in mountain gorillas. The one exception is the ulna, which shows a gradual increase in strength relative to the radius and other long bones during development, possibly corresponding to the gradual adoption of stereotypical fully pronated knuckle-walking in older juvenile gorillas. Inter-limb bone length proportions show a contrasting developmental pattern, with hind limb/forelimb length declining rapidly from birth to five months of age, and then showing no consistent change through adulthood. The very early change in length proportions, prior to significant independent locomotion, may be related to the need for relatively long forelimbs for climbing in a large-bodied hominoid. Virunga mountain gorilla older juveniles and adults have equal or longer forelimb relative to hind limb bones than western lowland adults. These findings indicate that both ontogenetically and among closely related species of Gorilla, long bone strength proportions better reflect actual locomotor behavior than bone length proportions.

  4. The hydraulic mechanism of the unfolding of hind wings in Dorcus titanus platymelus (order: Coleoptera).

    PubMed

    Sun, Jiyu; Ling, Mingze; Wu, Wei; Bhushan, Bharat; Tong, Jin

    2014-04-09

    In most beetles, the hind wings are thin and fragile; when at rest, they are held over the back of the beetle. When the hind wing unfolds, it provides the necessary aerodynamic forces for flight. In this paper, we investigate the hydraulic mechanism of the unfolding process of the hind wings in Dorcus titanus platymelus (Oder: Coleoptera). The wing unfolding process of Dorcus titanus platymelus was examined using high speed camera sequences (400 frames/s), and the hydraulic pressure in the veins was measured with a biological pressure sensor and dynamic signal acquisition and analysis (DSA) during the expansion process. We found that the total time for the release of hydraulic pressure during wing folding is longer than the time required for unfolding. The pressure is proportional to the length of the wings and the body mass of the beetle. A retinal camera was used to investigate the fluid direction. We found that the peak pressures correspond to two main cross-folding joint expansions in the hind wing. These observations strongly suggest that blood pressure facilitates the extension of hind wings during unfolding.

  5. The hydraulic mechanism in the hind wing veins of Cybister japonicus Sharp (order: Coleoptera).

    PubMed

    Sun, Jiyu; Wu, Wei; Ling, Mingze; Bhushan, Bharat; Tong, Jin

    2016-01-01

    The diving beetles (Dytiscidae, Coleoptera) are families of water beetles. When they see light, they fly to the light source directly from the water. Their hind wings are thin and fragile under the protection of their elytra (forewings). When the beetle is at rest the hind wings are folded over the abdomen of the beetle and when in flight they unfold to provide the necessary aerodynamic forces. In this paper, the unfolding process of the hind wing of Cybister japonicus Sharp (order: Coleoptera) was investigated. The motion characteristics of the blood in the veins of the structure system show that the veins have microfluidic control over the hydraulic mechanism of the unfolding process. A model is established, and the hind wing extending process is simulated. The blood flow and pressure changes are discussed. The driving mechanism for hydraulic control of the folding and unfolding actions of beetle hind wings is put forward. This can assist the design of new deployable micro air vehicles and bioinspired deployable systems.

  6. The hydraulic mechanism in the hind wing veins of Cybister japonicus Sharp (order: Coleoptera)

    PubMed Central

    Wu, Wei; Ling, Mingze; Tong, Jin

    2016-01-01

    Summary The diving beetles (Dytiscidae, Coleoptera) are families of water beetles. When they see light, they fly to the light source directly from the water. Their hind wings are thin and fragile under the protection of their elytra (forewings). When the beetle is at rest the hind wings are folded over the abdomen of the beetle and when in flight they unfold to provide the necessary aerodynamic forces. In this paper, the unfolding process of the hind wing of Cybister japonicus Sharp (order: Coleoptera) was investigated. The motion characteristics of the blood in the veins of the structure system show that the veins have microfluidic control over the hydraulic mechanism of the unfolding process. A model is established, and the hind wing extending process is simulated. The blood flow and pressure changes are discussed. The driving mechanism for hydraulic control of the folding and unfolding actions of beetle hind wings is put forward. This can assist the design of new deployable micro air vehicles and bioinspired deployable systems. PMID:27547607

  7. Analysis of the HindIII-catalyzed reaction by time-resolved crystallography

    SciTech Connect

    Kawamura, Takashi; Kobayashi, Tomoki; Watanabe, Nobuhisa

    2015-02-01

    A time-resolved study using the freeze-trap method elucidates the mechanism of the DNA-cleaving reaction of HindIII. In order to investigate the mechanism of the reaction catalyzed by HindIII, structures of HindIII–DNA complexes with varying durations of soaking time in cryoprotectant buffer containing manganese ions were determined by the freeze-trap method. In the crystal structures of the complexes obtained after soaking for a longer duration, two manganese ions, indicated by relatively higher electron density, are clearly observed at the two metal ion-binding sites in the active site of HindIII. The increase in the electron density of the two metal-ion peaks followed distinct pathways with increasing soaking times, suggesting variation in the binding rate constant for the two metal sites. DNA cleavage is observed when the second manganese ion appears, suggesting that HindIII uses the two-metal-ion mechanism, or alternatively that its reactivity is enhanced by the binding of the second metal ion. In addition, conformational change in a loop near the active site accompanies the catalytic reaction.

  8. Three-dimensional simulations of near-surface convection in main-sequence stars. IV. Effect of small-scale magnetic flux concentrations on centre-to-limb variation and spectral lines

    NASA Astrophysics Data System (ADS)

    Beeck, B.; Schüssler, M.; Cameron, R. H.; Reiners, A.

    2015-09-01

    Context. Magnetic fields affect the local structure of the photosphere of stars. They can considerably influence the radiative properties near the optical surface, flow velocities, and the temperature and pressure profiles. This has an impact on observables such as limb darkening and spectral line profiles. Aims: We aim at understanding qualitatively the influence of small magnetic flux concentrations in unipolar plage regions on the centre-to-limb variation of the intensity and its contrast and on the shape of spectral line profiles in cool main-sequence stars. Methods: We analyse the bolometric and continuum intensity and its angular dependence of 24 radiative magnetohydrodynamic simulations of the near-surface layers of main-sequence stars with six different sets of stellar parameters (spectral types F to early M) and four different average magnetic field strengths (including the non-magnetic case). We also calculated disc-integrated profiles of three spectral lines. Results: The small magnetic flux concentrations formed in the magnetic runs of simulations have a considerable impact on the intensity and its centre-to-limb variation. In some cases, the difference in limb darkening between magnetic and non-magnetic runs is larger than the difference between the spectral types. Spectral lines are not only broadened owing to the Zeeman effect, but are also strongly affected by the modified thermodynamical structure and flow patterns. This indirect magnetic impact on the line profiles is often bigger than that of the Zeeman effect. Conclusions: The effects of the magnetic field on the radiation leaving the star can be considerable and is not restricted to spectral line broadening and polarisation by the Zeeman effect. The inhomogeneous structure of the magnetic field on small length scales and its impact on (and spatial correlation with) the local thermodynamical structure and the flow field near the surface influence the measurement of the global field properties

  9. Effects of varying inter-limb spacing to limb length ratio in metachronal swimming

    NASA Astrophysics Data System (ADS)

    Lai, Hong Kuan; Merkel, Rachael; Santhanakrishnan, Arvind

    2016-11-01

    Crustaceans such as shrimp, krill and crayfish swim by rhythmic paddling of four to five pairs of closely spaced limbs. Each pair is phase-shifted in time relative to the neighboring pair, resulting in a metachronal wave that travels in the direction of animal motion. The broad goal of this study is to investigate how the mechanical design of the swimming limbs affect scalability of metachronal swimming in terms of limb-based Reynolds number (Re). A scaled robotic model of metachronal paddling was developed, consisting of four pairs of hinged acrylic plates actuated using stepper motors that were immersed in a rectangular tank containing water-glycerin fluid medium. 2D PIV measurements show that the propulsive jets transition from being primarily horizontal (thrust-producing direction) at Re of order 10 to angled vertically at Re of order 100. The ratio of inter-limb spacing to limb length among metachronal swimming organisms ranges between 0.2 to 0.65. 2D PIV will be used to examine the jets generated between adjacent limbs for varying inter-limb spacing to limb length ratios. The effect of increasing this ratio to beyond the biologically observed range will be discussed.

  10. Hox gene expression leads to differential hind leg development between honeybee castes.

    PubMed

    Bomtorin, Ana Durvalina; Barchuk, Angel Roberto; Moda, Livia Maria; Simoes, Zila Luz Paulino

    2012-01-01

    Beyond the physiological and behavioural, differences in appendage morphology between the workers and queens of Apis mellifera are pre-eminent. The hind legs of workers, which are highly specialized pollinators, deserve special attention. The hind tibia of worker has an expanded bristle-free region used for carrying pollen and propolis, the corbicula. In queens this structure is absent. Although the morphological differences are well characterized, the genetic inputs driving the development of this alternative morphology remain unknown. Leg phenotype determination takes place between the fourth and fifth larval instar and herein we show that the morphogenesis is completed at brown-eyed pupa. Using results from the hybridization of whole genome-based oligonucleotide arrays with RNA samples from hind leg imaginal discs of pre-pupal honeybees of both castes we present a list of 200 differentially expressed genes. Notably, there are castes preferentially expressed cuticular protein genes and members of the P450 family. We also provide results of qPCR analyses determining the developmental transcription profiles of eight selected genes, including abdominal-A, distal-less and ultrabithorax (Ubx), whose roles in leg development have been previously demonstrated in other insect models. Ubx expression in workers hind leg is approximately 25 times higher than in queens. Finally, immunohistochemistry assays show that Ubx localization during hind leg development resembles the bristles localization in the tibia/basitarsus of the adult legs in both castes. Our data strongly indicate that the development of the hind legs diphenism characteristic of this corbiculate species is driven by a set of caste-preferentially expressed genes, such as those encoding cuticular protein genes, P450 and Hox proteins, in response to the naturally different diets offered to honeybees during the larval period.

  11. An analysis of epipubic bone function in mammals using scaling theory.

    PubMed

    White, T D

    1989-08-09

    Linear dimensions of epipubic bones in 61 species of metatherians and monotremes scale to mass differently in groups with or without marsupia, presumably reflecting emphasis on different but non-mutually exclusive functions. Sexual dimorphism of epipubic form exists. However, the allometric relationships of the epipubic bones of taxa that possess marsupia do not conform to the hypothesis that epipubic bones support the marsupium nearly as well as those without a marsupium. This observation renders a new hypothesis relating litter mass to epipubic form in taxa without marsupia. It appears that support of the marsupium is not the primary function or, at least, not the most proximate determinate of epipubic form in taxa with marsupia. The scaling of epipubic bone dimensions is consistent with the hypothesis that predicts epipubic bones serve to assist in locomotion by acting with the hypaxial muscles of the trunk and pectineus to protract the pelvic limbs. Epipubic length is shown to scale to maintain a mechanical advantage between these opposing muscle groups that approximates the rate that inertia of the hind limbs increases with total mass and speed of locomotion. This hypothesis provides an explanation for a skeletal element scaling significantly above geometric similarity. This observation has important theoretical significance as it suggests that skeletal architecture may, within limits, scale independently of mass-related stress.

  12. Earth Limb Radiance Transformation.

    DTIC Science & Technology

    1981-03-02

    AD-A097 523 AEROSPACE CORP EL SEGUNDO CA CHEMISTRY AND PHYSICS LAB F/G 4/1 EARTH LIMB RADIANCE TRANSFORMATION (U) MAR AI S 4 YOUNG F0701-80 -C-0081... Earth Limb Radiance Trafisformation Prepared by S. J. YOUNG Chemistr and Physics Laboratory Laboratory Operations The Aerospace Corporation S.El...ITLEK (and Subtitle) TYPE OF REPORT & P53100 COVERED Earth Limb Radiance Transformation. ( Interim ./ / /TR-OJ081(697j7-g4)-l-- i7.Step hen J. Young

  13. Out on a Limb: Investigating the Anatomy of Tree Limbs

    ERIC Educational Resources Information Center

    Shaw, Edward L.

    2008-01-01

    The author presents several upper elementary science activities involving tree limbs that were collected after severe weather conditions. The activities involved 3rd-grade students arranging tree limb pieces in the correct order from the trunk to the tip of the limb, measuring the pieces, determining the age of a tree limb by its rings,…

  14. Phantom limb pain

    MedlinePlus

    ... Philadelphia, PA: Elsevier; 2015:chap 54. Nikolajsen L, Springer JS, Haroutiunian S. Phantom limb pain. In: Benzon HT, ... medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- ...

  15. Hyaluronan in limb morphogenesis.

    PubMed

    Li, Yingcui; Toole, Bryan P; Dealy, Caroline N; Kosher, Robert A

    2007-05-15

    Hyaluronan (HA) is a large glycosaminoglycan that is not only a structural component of extracellular matrices, but also interacts with cell surface receptors to promote cell proliferation, migration, and intracellular signaling. HA is a major component of the extracellular matrix of the distal subapical mesenchymal cells of the developing limb bud that are undergoing proliferation, directed migration, and patterning in response to the apical ectodermal ridge (AER), and has the functional potential to be involved in these processes. Here we show that the HA synthase Has2 is abundantly expressed by the distal subridge mesodermal cells of the chick limb bud and also by the AER itself. Has2 expression and HA production are downregulated in the proximal central core of the limb bud during the formation of the precartilage condensations of the skeletal elements, suggesting that downregulation of HA may be necessary for the close juxtaposition of cells and the resulting cell-cell interactions that trigger cartilage differentiation during condensation. Overexpression of Has2 in the mesoderm of the chick limb bud in vivo results in the formation of shortened and severely malformed limbs that lack one or more skeletal elements. Skeletal elements that do form in limbs overexpressing Has2 are reduced in length, exhibit abnormal morphology, and are positioned inappropriately. We also demonstrate that sustained HA production in micromass cultures of limb mesenchymal cells inhibits formation of precartilage condensations and subsequent chondrogenesis, indicating that downregulation of HA is indeed necessary for formation of the precartilage condensations that trigger cartilage differentiation. Taken together these results suggest involvement of HA in various aspects of limb morphogenesis.

  16. Production of prostaglandins in placentae and corpus luteum in pregnant hinds of red deer (Cervus elaphus).

    PubMed

    Korzekwa, A J; Szczepańska, A; Bogdaszewski, M; Nadolski, P; Malż, P; Giżejewski, Z

    2016-03-01

    Prostaglandins (PGs) are synthesized from arachidonic acid by prostaglandin synthase 2 (PTGS2) and specific terminal PG synthases such as PGES and PGFS. The role of PGs in the reproductive processes of domestic ruminants is well recognized, whereas in cervidae, it is almost unknown, although it is noteworthy because some species of this family are valued in meat production and trophies. The aim of this study was to determine an effective marker of pregnancy and investigate the production and secretion of PGs in placenta and CL tissue in pregnancy. In the preliminary experiment, the levels of progesterone and 17-β estradiol (RIA; N = 14 divided into seven pregnant and seven nonpregnant hinds) were measured in the peripheral blood. In the main experiment, a comparison of messenger RNA (real-time polymerase chain reaction) and protein expression (Western blotting) of PTGS2, PGES, and PGFS, the level of prostaglandin E2 (PGE2) and PGF2α in the placentae and CL in pregnant hinds (aged 3-4 years, ca. 100 days of pregnancy, N = 6). In pregnant hinds, the level of progesterone in the blood was higher than that in nonpregnant hinds (P < 0.05), whereas the level of E2 was similar in all animals (P > 0.05). The highest messenger RNA expression of PTGS2, PGES, and PGFS was observed in the placentae than in the CL (P < 0.05). The protein expression of PTGS2 and PGES was elevated in the placentae compared with the CL (P < 0.05). The PGE2 output was the highest in cotyledonary tissue (P < 0.05). Pregnancy development in hinds around 100 days is regulated by arachidonic acid metabolites, especially PGE2 produced by the placentae, which production increases in pregnancy. Further studies are required to unravel the mechanisms involved in the regulation of PG and biosynthetic enzymes in uteroplacental and ovarian tissues during pregnancy in red deer females.

  17. Limb regeneration: a new development?

    PubMed

    Nacu, Eugen; Tanaka, Elly M

    2011-01-01

    Salamander limb regeneration is a classical model of tissue morphogenesis and patterning. Through recent advances in cell labeling and molecular analysis, a more precise, mechanistic understanding of this process has started to emerge. Long-standing questions include to what extent limb regeneration recapitulates the events observed in mammalian limb development and to what extent are adult- or salamander- specific aspects deployed. Historically, researchers studying limb development and limb regeneration have proposed different models of pattern formation. Here we discuss recent data on limb regeneration and limb development to argue that although patterning mechanisms are likely to be similar, cell plasticity and signaling from nerves play regeneration-specific roles.

  18. Limb development and evolution: a frog embryo with no apical ectodermal ridge (AER)

    PubMed Central

    RICHARDSON, MICHAEL K.; CARL, TIMOTHY F.; HANKEN, JAMES; ELINSON, RICHARD P.; COPE, CELIA; BAGLEY, PETER

    1998-01-01

    The treefrog Eleutherodactylus coqui is a direct developer — it has no tadpole stage. The limb buds develop earlier than in metamorphosing species (indirect developers, such as Xenopus laevis). Previous molecular studies suggest that at least some mechanisms of limb development in E. coqui are similar to those of other vertebrates and we wished to see how limb morphogenesis in this species compares with that in other vertebrates. We found that the hind limb buds are larger and more advanced than the forelimbs at all stages examined, thus differing from the typical amniote pattern. The limb buds were also small compared to those in the chick. Scanning and transmission electron microscopy showed that although the apical ectoderm is thickened, there was no apical ectodermal ridge (AER). In addition, the limb buds lacked the dorsoventral flattening seen in many amniotes. These findings could suggest a mechanical function for the AER in maintaining dorsoventral flattening, although not all data are consistent with this view. Removal of distal ectoderm from E. coqui hindlimb buds does not stop outgrowth, although it does produce anterior defects in the skeletal pattern. The defects are less severe when the excisions are performed earlier. These results contrast with the chick, in which AER excision leads to loss of distal structures. We suggest that an AER was present in the common ancestor of anurans and amniotes and has been lost in at least some direct developers including E. coqui. PMID:9688504

  19. Unsteady aerodynamics of flapping flight - A fluid-structure interaction study of fore-hind wing phase difference

    NASA Astrophysics Data System (ADS)

    Rasani, M. R.; Shamsudeen, A.; Sulaiman, M. N.

    2016-11-01

    Flights of dragonflies, various insects and birds have been a subject of active research that may offer insight towards enhanced aerodynamic performance at low Reynolds numbers. To that end, we mimick the flapping biomechanics of a dragonfly by two thin flat airfoils plunging in tandem with each other. In the present study, we aim to investigate the effect of difference in flapping phase between fore and hind wings towards their aerodynamic performances. We computationally simulate incompressible, viscous, laminar flow around two thin flat airfoils that are purely plunging, at a Strouhal number of 0.25 and Reynolds number of 6500, using a flow solver in an Arbitrary Lagrangian-Eulerian framework. Kinematics of both fore and hind wing flapping followed a similar sinusoidal function but with relative phase angle difference to each other, that were varied between -50° to +50° including two cases were phase difference is 0° (i.e. in-phase fore-hind wing flapping) and +90° (i.e. fore wing lags hind wing by 90°). Numerical results indicate that maximum lift and drag forces for each fore and hind wings occur at phase angle of -40° and that power efficiency of tandem wings are better at phase angles when hind wing leads the fore wing, with maximum power efficiency occurring at a fore-hind wing phase difference of +30°. The complex fore-hind wing vortex interaction indicate likely benefit on the hind wing as it interacts with the fore wing at different phase angles.

  20. Limb salvage surgery

    PubMed Central

    Kadam, Dinesh

    2013-01-01

    The threat of lower limb loss is seen commonly in severe crush injury, cancer ablation, diabetes, peripheral vascular disease and neuropathy. The primary goal of limb salvage is to restore and maintain stability and ambulation. Reconstructive strategies differ in each condition such as: Meticulous debridement and early coverage in trauma, replacing lost functional units in cancer ablation, improving vascularity in ischaemic leg and providing stable walking surface for trophic ulcer. The decision to salvage the critically injured limb is multifactorial and should be individualised along with laid down definitive indications. Early cover remains the standard of care, delayed wound coverage not necessarily affect the final outcome. Limb salvage is more cost-effective than amputations in a long run. Limb salvage is the choice of procedure over amputation in 95% of limb sarcoma without affecting the survival. Compound flaps with different tissue components, skeletal reconstruction; tendon transfer/reconstruction helps to restore function. Adjuvant radiation alters tissue characters and calls for modification in reconstructive plan. Neuropathic ulcers are wide and deep often complicated by osteomyelitis. Free flap reconstruction aids in faster healing and provides superior surface for offloading. Diabetic wounds are primarily due to neuropathy and leads to six-fold increase in ulcerations. Control of infections, aggressive debridement and vascular cover are the mainstay of management. Endovascular procedures are gaining importance and have reduced extent of surgery and increased amputation free survival period. Though the standard approach remains utilising best option in the reconstruction ladder, the recent trend shows running down the ladder of reconstruction with newer reliable local flaps and negative wound pressure therapy. PMID:24501463

  1. [Limb edema and lymphoscintigraphy].

    PubMed

    Bourgeois, P; Munck, D; Belgrado, J P; Leduc, O; Leduc, A

    2003-02-01

    Lymphoscintigraphic investigations represent techniques of nuclear medicine very contributive for the management and treatment of the limb edemas, either primary or secundary. Their principle is presented and methodologies proposed in the literature are reviewed. Their diagnostic contributions are detailed. The sensitivities and specificities of several protocols of investigation are reported. Some limitations of these examinations are analyzed and discussed. Clinical indications for their use are proposed and their interest with regard to the various treatments that can be applied to these limb edemas is discussed.

  2. JKTLD: Limb darkening coefficients

    NASA Astrophysics Data System (ADS)

    Southworth, John

    2015-11-01

    JKTLD outputs theoretically-calculated limb darkening (LD) strengths for equations (LD laws) which predict the amount of LD as a function of the part of the star being observed. The coefficients of these laws are obtained by bilinear interpolation (in effective temperature and surface gravity) in published tables of coefficients calculated from stellar model atmospheres by several researchers. Many observations of stars require the strength of limb darkening (LD) to be estimated, which can be done using theoretical models of stellar atmospheres; JKTLD can help in these circumstances.

  3. Interaction between the fore- and hind-wings in hovering flight of modelled dragonfly

    NASA Astrophysics Data System (ADS)

    Kweon, Jihoon; Choi, Haecheon

    2009-11-01

    In the present study, we investigate the interaction between the fore- and hind-wings in hovering flight of modelled dragonfly using 3D numerical simulation. The three-dimensional wing shape is based on that of Aeschna juncea (Norberg 1972) and numerically realized using an immersed boundary method (Kim et al. 2001). The wing flapping motion is modelled using a sinusoidal function and the stroke plane angle is 60^o. We consider 12 different phase differences between the fore- and hind-wings (φ=0^o ˜ 330^o). The Reynolds number is 1,000 based on the maximum translational velocity and mean chord length. In counter stroke (φ=180^o), the wing-tip vortices from both wings are connected, generating an entangled wing-tip vortex (e-WTV). A strong downward motion induced by this vortex decreases the vertical force in the following stroke (Kweon & Choi 2008). In parallel stroke (φ=0^o), both wings meet e-WTV during the upstroke and thus the decrease of vertical force is small. At φ=270^o, although e-WTV is generated on a relatively narrow region, the hind-wing moves downward along with e-WTV, resulting in a significant reduction of vertical force on the hind-wing. Therefore, the sum of vertical forces on both wings is maximum with parallel stroke and minimum at φ=270^o. The power required has a similar trend to the vertical force and thus the efficiency does not show a large variation with the phase difference.

  4. Nifedipine improves blood flow and oxygen supply, but not steady-state oxygenation of tumours in perfusion pressure-controlled isolated limb perfusion.

    PubMed

    Thews, O; Hummel, M; Kelleher, D K; Lecher, B; Vaupel, P

    2002-12-02

    Isolated limb perfusion allows the direct application of therapeutic agents to a tumour-bearing extremity. The present study investigated whether the dihydropyridine-type Ca(2+)-channel blocker nifedipine could improve blood flow and oxygenation status of experimental tumours during isolated limb perfusion. Perfusion was performed by cannulation of the femoral artery and vein in rats bearing DS-sarcoma on the hind foot dorsum. Perfusion rate was adjusted to maintain a perfusion pressure of 100-140 mmHg throughout the experiment. Following equilibration, nifedipine was continuously infused for 30 min (8.3 microg min(-1) kg(-1) BW). During constant-pressure isolated limb perfusion, nifedipine can significantly increase perfusion rate (+100%) and RBC flux (+60%) through experimental leg tumours. "Steal phenomena" in favour of the surrounding normal tissue and oedema formation were not observed. Despite the increased oxygen availability (+63%) seen upon application of this calcium channel blocker, nifedipine does not result in a substantial reduction of tumour hypoxia, most probably due to an increase in O(2) uptake with rising O(2) supply to the tumour-bearing hind limb. Nifedipine application during isolated limb perfusion can enhance tumour microcirculation and may therefore promote the delivery (pharmacokinetics) of anti-cancer drugs to the tumour and by this improve the efficacy of pressure-controlled isolated limb perfusion.

  5. HindSight: Encouraging Exploration through Direct Encoding of Personal Interaction History.

    PubMed

    Feng, Mi; Deng, Cheng; Peck, Evan M; Harrison, Lane

    2017-01-01

    Physical and digital objects often leave markers of our use. Website links turn purple after we visit them, for example, showing us information we have yet to explore. These "footprints" of interaction offer substantial benefits in information saturated environments - they enable us to easily revisit old information, systematically explore new information, and quickly resume tasks after interruption. While applying these design principles have been successful in HCI contexts, direct encodings of personal interaction history have received scarce attention in data visualization. One reason is that there is little guidance for integrating history into visualizations where many visual channels are already occupied by data. More importantly, there is not firm evidence that making users aware of their interaction history results in benefits with regards to exploration or insights. Following these observations, we propose HindSight - an umbrella term for the design space of representing interaction history directly in existing data visualizations. In this paper, we examine the value of HindSight principles by augmenting existing visualizations with visual indicators of user interaction history (e.g. How the Recession Shaped the Economy in 255 Charts, NYTimes). In controlled experiments of over 400 participants, we found that HindSight designs generally encouraged people to visit more data and recall different insights after interaction. The results of our experiments suggest that simple additions to visualizations can make users aware of their interaction history, and that these additions significantly impact users' exploration and insights.

  6. Cloning and genetic variability of a HindIII repetitive DNA in Acrossocheilus paradoxus (Cyprinidae).

    PubMed

    Wu, W L; Wang, J P; Tseng, M C; Chiang, T Y

    1999-08-01

    Thirty clones of a highly repetitive HindIII fragment of DNA from seven populations of Acrossocheilus paradoxus (Cyprinidae) were isolated and sequenced. The fragment represents a tandemly repeated sequence, with a monomeric unit of 270 bp, amounting to 0.08-0.10% of the fish genome. Higher units of this monomer appear as a ladder in Southern blots. The HindIII satellite DNA family is conserved in three genera of the Cyprinidae. Variation in nucleotide sequences of this repetitive fragment, which is A+T-rich, is distributed both within individuals and among populations. High overall nucleotide divergence (dij = 0.056 +/- 0.001) was detected among clones of the HindIII satellite DNAs of Acrossocheilus paradoxus. Based on the molecular clock hypothesis, the maximum evolutionary rate was estimated to be 5.3 x 10(-7) substitutions per site per year. Lineage sorting may have contributed to the genetic heterogeneity within individuals and populations. Cladistic analyses indicated a closer phylogeographic relationship between populations of the central and south regions in Taiwan.

  7. Artificial limb connection

    NASA Technical Reports Server (NTRS)

    Owens, L. J.

    1974-01-01

    Connection simplifies and eases donning and removing artificial limb; eliminates harnesses and clamps; and reduces skin pressures by allowing bone to carry all tensile and part of compressive loads between prosthesis and stump. Because connection is modular, it is easily modified to suit individual needs.

  8. Proteomic analysis of blastema formation in regenerating axolotl limbs

    PubMed Central

    2009-01-01

    Background Following amputation, urodele salamander limbs reprogram somatic cells to form a blastema that self-organizes into the missing limb parts to restore the structure and function of the limb. To help understand the molecular basis of blastema formation, we used quantitative label-free liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS)-based methods to analyze changes in the proteome that occurred 1, 4 and 7 days post amputation (dpa) through the mid-tibia/fibula of axolotl hind limbs. Results We identified 309 unique proteins with significant fold change relative to controls (0 dpa), representing 10 biological process categories: (1) signaling, (2) Ca2+ binding and translocation, (3) transcription, (4) translation, (5) cytoskeleton, (6) extracellular matrix (ECM), (7) metabolism, (8) cell protection, (9) degradation, and (10) cell cycle. In all, 43 proteins exhibited exceptionally high fold changes. Of these, the ecotropic viral integrative factor 5 (EVI5), a cell cycle-related oncoprotein that prevents cells from entering the mitotic phase of the cell cycle prematurely, was of special interest because its fold change was exceptionally high throughout blastema formation. Conclusion Our data were consistent with previous studies indicating the importance of inositol triphosphate and Ca2+ signaling in initiating the ECM and cytoskeletal remodeling characteristic of histolysis and cell dedifferentiation. In addition, the data suggested that blastema formation requires several mechanisms to avoid apoptosis, including reduced metabolism, differential regulation of proapoptotic and antiapoptotic proteins, and initiation of an unfolded protein response (UPR). Since there is virtually no mitosis during blastema formation, we propose that high levels of EVI5 function to arrest dedifferentiated cells somewhere in the G1/S/G2 phases of the cell cycle until they have accumulated under the wound epidermis and enter mitosis in response to neural and

  9. Interaction of the elytra and hind wing of a rhinoceros beetle (Trypoxylus dichotomus) during a take-off mode

    NASA Astrophysics Data System (ADS)

    Oh, Seungyoung; Oh, Sehyeong; Choi, Haecheon; Lee, Boogeon; Park, Hyungmin; Kim, Sun-Tae

    2015-11-01

    The elytra are a pair of hardened wings that cover the abdomen of a beetle to protect beetle's hind wings. During the take-off, these elytra open and flap in phase with the hind wings. We investigate the effect of the elytra flapping on beetle's aerodynamic performance. Numerical simulations are performed at Re=10,000 (based on the wingtip mean velocity and mean chord length of the hind wing) using an immersed boundary method. The simulations are focused on a take-off, and the wing kinematics used is directly obtained from the experimental observations using high speed cameras. The simulation result shows three-dimensional vortical structures generated by the hind wing of the beetle and their interaction with the elytra. The presence of elytra has a negative effect on the lift generation by the hind wings, but the lift force on the elytra themselves is negligible. Further discussions on the elytra - hind wing interaction will be provided during the presentation. Supported by UD130070ID.

  10. Diversity of limb-bone safety factors for locomotion in terrestrial vertebrates: evolution and mixed chains.

    PubMed

    Blob, Richard W; Espinoza, Nora R; Butcher, Michael T; Lee, Andrew H; D'Amico, Angela R; Baig, Faraz; Sheffield, K Megan

    2014-12-01

    During locomotion over land, vertebrates' limb bones are exposed to loads. Like most biological structures, limb bones have a capacity to withstand greater loads than they usually experience, termed a safety factor (SF). How diverse are limb-bone SFs, and what factors correlate with such variation? We have examined these questions from two perspectives. First, we evaluated locomotor SF for the femur in diverse lineages, including salamanders, frogs, turtles, lizards, crocodilians, and marsupials (opossums). Comparisons with values for hind-limb elements in running birds and eutherian mammals indicate phylogenetic diversity in limb-bone SF. A high SF (∼7) is primitive for tetrapods, but low magnitudes of load and elevated strength of bones contribute to different degrees across lineages; moreover, birds and eutherians appear to have evolved lower SFs independently. Second, we tested the hypothesis that SFs would be similar across limb bones within a taxon by comparing data from the humerus and femur of alligators. Both in bending and in torsion, we found a higher SF for the humerus than for the femur. Such a "mixed chain" of different SFs across elements has been predicted if bones have differing variabilities in load, different costs to maintain, or high SF values in general. Although variability in load is similar for the humerus and femur, a high SF may be less costly for the humerus because it is smaller than the femur. The high SFs of alligators also might facilitate differences in SF among their limb bones. Beyond these specific findings, however, a more general implication of our results is that evaluations of the diversity of limb-bone SFs can provide important perspective to direct future research. In particular, more complete understanding of variation in SF could provide insight into factors that promoted the evolutionary radiation of terrestrial locomotor function in vertebrates.

  11. CRISM Limb Observations of Aerosols and Water Vapor

    NASA Technical Reports Server (NTRS)

    Smith, Michael D.; Wolff, M.J.; Clancy, R.T.; Seelos, F.; Murchie, S.L.

    2009-01-01

    Near-infrared spectra taken in a limb-viewing geometry by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) on-board the Mars Reconnaissance Orbiter (MRO) provide a useful tool for probing atmospheric structure. Here we describe preliminary work on the retrieval of vertical profiles of aerosols and water vapor from the CRISM limb observations. The first full set of CRISM limb observations was taken in July 2009, with subsequent limb observations planned once every two months. Each set of limb observations contains about four dozen scans across the limb giving pole-to-pole coverage for two orbits at roughly 100 and 290 W longitude. Radiative transfer modeling taking account of aerosol scattering in the limb-viewing geometry is used to model the observations. The retrievals show the height to which dust and water vapor extend and the location and height of water ice clouds. Results from the First set of CRISM limb observations (July 2009, Ls=300) show dust aerosol well-mixed to about three scale heights above the surface with thin water ice clouds above the dust near the equator and at mid-northern latitudes. Water vapor is concentrated at high southern latitudes.

  12. Experimental investigation of crustacean swimming with variation of limb structures

    NASA Astrophysics Data System (ADS)

    Lai, Hong Kuan; Samaee, Milad; Donnell, Geoffrey; Santhanakrishnan, Arvind; Guy, Robert; Lewis, Timothy

    2015-11-01

    Crustaceans such as crayfish and krill swim by rhythmically paddling a set of four to five limbs (known as swimmerets or pleopods) originating from their abdomen. The limb motion in these animals has been observed to follow tail-to-head metachronal wave pattern with an approximate quarter-period inter-limb phase difference. The goal of this study is to investigate the hydrodynamics of this swimming mechanism as a function of inter-limb phase difference, inclusion of hinges in the limbs, and Reynolds number (Re). 2D PIV measurements were conducted on a scaled robotic model of metachronal paddling, consisting of a rectangular tank fitted with stepper motors coupled to a four-bar linkage that actuated four paddles immersed in water-glycerin fluid medium. The inter-limb phase difference was varied from 0% (synchronous paddling) through 50% across Re range of O(10-1000). Two types of limb models were used, including a simple flat plate and a `split-paddle' structure with two flat plates connected halfway with hinges. The results of the study show that limb models with hinges generated increased horizontal (thrust-producing direction) fluid velocity compared to the simple flat plate paddles, suggesting that asymmetry between power and return strokes is important to augment thrust.

  13. Regeneration inducers in limb regeneration.

    PubMed

    Satoh, Akira; Mitogawa, Kazumasa; Makanae, Aki

    2015-08-01

    Limb regeneration ability, which can be observed in amphibians, has been investigated as a representative phenomenon of organ regeneration. Recently, an alternative experimental system called the accessory limb model was developed to investigate early regulation of amphibian limb regeneration. The accessory limb model contributed to identification of limb regeneration inducers in urodele amphibians. Furthermore, the accessory limb model may be applied to other species to explore universality of regeneration mechanisms. This review aims to connect the insights recently gained to emboss universality of regeneration mechanisms among species. The defined molecules (BMP7 (or2) + FGF2 + FGF8) can transform skin wound healing to organ (limb) regeneration responses. The same molecules can initiate regeneration responses in some species.

  14. Radiographic features of the limbs of juvenile and subadult loggerhead sea turtles (Caretta caretta)

    PubMed Central

    Valente, Ana Luisa; Marco, Ignasi; Zamora, Maria Angeles; Parga, Maria Luz; Lavín, Santiago; Alegre, Ferran; Cuenca, Rafaela

    2007-01-01

    This study aimed to provide the normal radiographic anatomic appearance of the limbs of the loggerhead sea turtle, Caretta caretta. Dorsopalmar and dorsoplantar radiographs were taken of the forelimbs and hindlimbs of 15 juvenile and 15 subadult loggerhead sea turtles, 17 alive and 13 dead. For comparison, computed tomographic, gross anatomic, osteologic, and histologic studies were performed on the limbs of 5 of the sea turtles. Bones from the distal part of the fore and hind flippers were seen in detail with a mammographic film–screen combination. The pectoral and pelvic girdles, superimposed by the carapace, were better seen on standard radiographs with the use of rare-earth intensifying screens. Mammographic radiographs of the manus of 5 small juvenile turtles showed active growth zones. Visualization of bone contours in the distal part of the limbs was clearer than in mammals owing to the very few superimpositions. The presence of a substantial amount of cartilage in the epiphyses produced better visibility of limb ends. We conclude that use of a mammography film–screen combination is the best way to evaluate the bony and joint structures of the limbs of sea turtles. Radiography provides reliable images for clinical purposes. Considering the low cost and logistics of this technique, it is a practical ancillary test for marine animal rehabilitation centers to use. PMID:17955906

  15. Passive resting state and history of antagonist muscle activity shape active extensions in an insect limb

    PubMed Central

    Ache, Jan M.

    2012-01-01

    Limb movements can be driven by muscle contractions, external forces, or intrinsic passive forces. For lightweight limbs like those of insects or small vertebrates, passive forces can be large enough to overcome the effects of gravity and may even generate limb movements in the absence of active muscle contractions. Understanding the sources and actions of such forces is therefore important in understanding motor control. We describe passive properties of the femur-tibia joint of the locust hind leg. The resting angle is determined primarily by passive properties of the relatively large extensor tibiae muscle and is influenced by the history of activation of the fast extensor tibiae motor neuron. The resting angle is therefore better described as a history-dependent resting state. We selectively stimulated different flexor tibiae motor neurons to generate a range of isometric contractions of the flexor tibiae muscle and then stimulated the fast extensor tibiae motor neuron to elicit active tibial extensions. Residual forces in the flexor muscle have only a small effect on subsequent active extensions, but the effect is larger for distal than for proximal flexor motor neurons and varies with the strength of flexor activation. We conclude that passive properties of a lightweight limb make substantial and complex contributions to the resting state of the limb that must be taken into account in the patterning of neuronal control signals driving its active movements. Low variability in the effects of the passive forces may permit the nervous system to accurately predict their contributions to behavior. PMID:22357791

  16. Spatial Distribution and Conservation of Speckled Hind and Warsaw Grouper in the Atlantic Ocean off the Southeastern U.S.

    PubMed Central

    Farmer, Nicholas A.; Karnauskas, Mandy

    2013-01-01

    There is broad interest in the development of efficient marine protected areas (MPAs) to reduce bycatch and end overfishing of speckled hind (Epinephelus drummondhayi) and warsaw grouper (Hyporthodus nigritus) in the Atlantic Ocean off the southeastern U.S. We assimilated decades of data from many fishery-dependent, fishery-independent, and anecdotal sources to describe the spatial distribution of these data limited stocks. A spatial classification model was developed to categorize depth-grids based on the distribution of speckled hind and warsaw grouper point observations and identified benthic habitats. Logistic regression analysis was used to develop a quantitative model to predict the spatial distribution of speckled hind and warsaw grouper as a function of depth, latitude, and habitat. Models, controlling for sampling gear effects, were selected based on AIC and 10-fold cross validation. The best-fitting model for warsaw grouper included latitude and depth to explain 10.8% of the variability in probability of detection, with a false prediction rate of 28–33%. The best-fitting model for speckled hind, per cross-validation, included latitude and depth to explain 36.8% of the variability in probability of detection, with a false prediction rate of 25–27%. The best-fitting speckled hind model, per AIC, also included habitat, but had false prediction rates up to 36%. Speckled hind and warsaw grouper habitats followed a shelf-edge hardbottom ridge from North Carolina to southeast Florida, with speckled hind more common to the north and warsaw grouper more common to the south. The proportion of habitat classifications and model-estimated stock contained within established and proposed MPAs was computed. Existing MPAs covered 10% of probable shelf-edge habitats for speckled hind and warsaw grouper, protecting 3–8% of speckled hind and 8% of warsaw grouper stocks. Proposed MPAs could add 24% more probable shelf-edge habitat, and protect an additional 14–29% of

  17. Spatial distribution and conservation of speckled hind and warsaw grouper in the Atlantic Ocean off the southeastern U.S.

    PubMed

    Farmer, Nicholas A; Karnauskas, Mandy

    2013-01-01

    There is broad interest in the development of efficient marine protected areas (MPAs) to reduce bycatch and end overfishing of speckled hind (Epinephelus drummondhayi) and warsaw grouper (Hyporthodus nigritus) in the Atlantic Ocean off the southeastern U.S. We assimilated decades of data from many fishery-dependent, fishery-independent, and anecdotal sources to describe the spatial distribution of these data limited stocks. A spatial classification model was developed to categorize depth-grids based on the distribution of speckled hind and warsaw grouper point observations and identified benthic habitats. Logistic regression analysis was used to develop a quantitative model to predict the spatial distribution of speckled hind and warsaw grouper as a function of depth, latitude, and habitat. Models, controlling for sampling gear effects, were selected based on AIC and 10-fold cross validation. The best-fitting model for warsaw grouper included latitude and depth to explain 10.8% of the variability in probability of detection, with a false prediction rate of 28-33%. The best-fitting model for speckled hind, per cross-validation, included latitude and depth to explain 36.8% of the variability in probability of detection, with a false prediction rate of 25-27%. The best-fitting speckled hind model, per AIC, also included habitat, but had false prediction rates up to 36%. Speckled hind and warsaw grouper habitats followed a shelf-edge hardbottom ridge from North Carolina to southeast Florida, with speckled hind more common to the north and warsaw grouper more common to the south. The proportion of habitat classifications and model-estimated stock contained within established and proposed MPAs was computed. Existing MPAs covered 10% of probable shelf-edge habitats for speckled hind and warsaw grouper, protecting 3-8% of speckled hind and 8% of warsaw grouper stocks. Proposed MPAs could add 24% more probable shelf-edge habitat, and protect an additional 14-29% of speckled

  18. Scales

    MedlinePlus

    Scales are a visible peeling or flaking of outer skin layers. These layers are called the stratum ... Scales may be caused by dry skin, certain inflammatory skin conditions, or infections. Eczema , ringworm , and psoriasis ...

  19. Anisotropy and non-homogeneity of an Allomyrina Dichotoma beetle hind wing membrane.

    PubMed

    Ha, N S; Jin, T L; Goo, N S; Park, H C

    2011-12-01

    Biomimetics is one of the most important paradigms as researchers seek to invent better engineering designs over human history. However, the observation of insect flight is a relatively recent work. Several researchers have tried to address the aerodynamic performance of flapping creatures and other natural properties of insects, although there are still many unsolved questions. In this study, we try to answer the questions related to the mechanical properties of a beetle's hind wing, which consists of a stiff vein structure and a flexible membrane. The membrane of a beetle's hind wing is small and flexible to the point that conventional methods cannot adequately quantify the material properties. The digital image correlation method, a non-contact displacement measurement method, is used along with a specially designed mini-tensile testing system. To reduce the end effects, we developed an experimental method that can deal with specimens with as high an aspect ratio as possible. Young's modulus varies over the area in the wing and ranges from 2.97 to 4.5 GPa in the chordwise direction and from 1.63 to 2.24 GPa in the spanwise direction. Furthermore, Poisson's ratio in the chordwise direction is 0.63-0.73 and approximately twice as large as that in the spanwise direction (0.33-0.39). From these results, we can conclude that the membrane of a beetle's hind wing is an anisotropic and non-homogeneous material. Our results will provide a better understanding of the flapping mechanism through the formulation of a fluid-structure interaction analysis or aero-elasticity analysis and meritorious data for biomaterial properties database as well as a creative design concept for a micro aerial flapper that mimics an insect.

  20. Anatomy of the hind legs and actions of their muscles during jumping in leafhopper insects.

    PubMed

    Burrows, Malcolm

    2007-10-01

    The rapid and simultaneous depression of the trochantera about the coxae of both hind legs of leafhoppers are the key joint movements powering a jump. The present study analyses the structure of these joints and the actions of the muscles that move them. The hind coxae are huge and are linked to each other at the midline by a protrusion from one coxa that inserts in a socket of the other and acts like a press-stud (popper) fastener. This asymmetry is not reflected in any left- or right-handed preference either within one species or between species. The movements of the joints in a jump are monitored by a number of possible proprioceptors that should be activated when a hind leg is fully levated in preparation for a jump: a hair row and two hair plates on the coxa, a hair plate on a trochanteral pivot with a coxa, and femoral spines at the femoro-tibial joint. The depressor and levator muscles that move the trochanter are of similar size and together occupy the greater part of the metathorax. Their lever arms are similar when the leg is fully levated, but the lever arm of the depressor increases with initial depression of the coxo-trochanteral joint while that of the levator declines. A jump is preceded by activity in the trochanteral depressor and levator muscles, which results in a forward movement of the coxa and metathorax with the trochanter fully levated. This period of co-contraction could result in storage of energy in skeletal structures in the thorax. Just before the rapid depression of the trochanter in the jump movement the frequency of depressor spikes increases while that in the levator declines, releasing any force stored by the preceding muscle contractions. These bursts of depressor spikes occur at the same time in the left and right muscles but none of the individual motor spikes appeared to be synchronous on the two sides.

  1. A new technique using roentgen stereophotogrammetry to measure changes in the spatial conformation of bovine hind claws in response to external loads.

    PubMed

    Ouweltjes, W; Gussekloo, S W S; Spoor, C W; van Leeuwen, J L

    2016-02-01

    Claw and locomotion problems are widespread in ungulates. Although it is presumed that mechanical overload is an important contributor to claw tissue damage and impaired locomotion, deformation and claw injury as a result of mechanical loading has been poorly quantified and, as a result, practical solutions to reduce such lesions have been established mostly through trial and error. In this study, an experimental technique was developed that allowed the measurement under controlled loading regimes of minute deformations in the lower limbs of dissected specimens from large ungulates. Roentgen stereophotogrammetric analysis (RSA) was applied to obtain 3D marker coordinates with an accuracy of up to 0.1 mm with optimal contrast and to determine changes in the spatial conformation. A force plate was used to record the applied forces in three dimensions. The results obtained for a test sample (cattle hind leg) under three loading conditions showed that small load-induced deformations and translations as well as small changes in centres of force application could be measured. Accuracy of the order of 0.2-0.3 mm was feasible under practical circumstances with suboptimal contrast. These quantifications of claw deformation during loading improve understanding of the spatial strain distribution as a result of external loading and the risks of tissue overload. The method promises to be useful in determining load-deformation relationships for a wide variety of specimens and circumstances.

  2. Claw and limb disorders in 12 Norwegian beef-cow herds

    PubMed Central

    Fjeldaas, Terje; Nafstad, Ola; Fredriksen, Bente; Ringdal, Grethe; Sogstad, Åse M

    2007-01-01

    Background The main aim of the study was to assess the prevalence of claw and limb disorders in Norwegian beef-cow herds. Methods Twenty-six herds with ≥15 cow-years were selected by computerized systematic assignment from the three most beef cattle-dense regions of Norway. The study population consisted of 12 herds with 28 heifers and 334 cows. The animals were trimmed and examined once by claw trimmers during the late winter and spring of 2003. The seven claw trimmers had been taught diagnosing and recording of claw lesions. Environment, feeding and management routines, age and breed, culling and carcass characteristics were also recorded. Results Lameness was recorded in 1.1% of the animals, and only in hind claws. Pericarpal swellings were recorded in one animal and peritarsal lesions in none. In total, claw and limb disorders including lameness were recorded in 29.6% of the animals, 4.1% with front and 28.2% with hind limb disorders, respectively. Most lesions were mild. Laminitis-related claw lesions were recorded in 18.0% of the animals and infectious lesions in 16.6%. The average claw length was 84 mm in front claws and 89 mm in hind claw. Both laminitis-related and infectious claw lesions were more prevalent with increasing age. Carcasses from animals with claw and limb disorders were on average 34 kg heavier than carcasses from animals without such disorders (p = 0.02). Our results also indicate association between some management factors and claw lesions. Conclusion The study shows that the prevalence of lameness was low in 12 Norwegian beef-cow herds compared to beef-cattle herds in other countries and also that there were less claw and limb disorders in these herds compared to foreign dairy-cattle herds. The prevalence of lameness and white-line fissures was approximately the same as in Norwegian dairy herds whereas less dermatitis, heel-horn erosions, haemorrhages of the sole and the white line and sole ulcers were recorded. PMID:17892582

  3. Acute and chronic nociceptive phases observed in a rat hind paw ischemia/reperfusion model depend on different mechanisms.

    PubMed

    Klafke, J Z; da Silva, M A; Rossato, M F; de Prá, S Dal Toé; Rigo, F K; Walker, C I B; Bochi, G V; Moresco, R N; Ferreira, J; Trevisan, G

    2016-02-01

    Complex regional pain syndrome type 1 (CRPS1) may be evoked by ischemia/reperfusion, eliciting acute and chronic pain that is difficult to treat. Despite this, the underlying mechanism of CRPS1 has not been fully elucidated. Therefore, the goal of this study is to evaluate the involvement of inflammation, oxidative stress, and the transient receptor potential ankyrin 1 (TRPA1) channel, a chemosensor of inflammation and oxidative substances, in an animal model of chronic post-ischemia pain (CPIP). Male Wistar rats were subjected to 3 h hind paw ischemia/reperfusion (CPIP model). Different parameters of nociception, inflammation, ischemia, and oxidative stress were evaluated at 1 (acute) and 14 (chronic) days after CPIP. The effect of a TRPA1 antagonist and the TRPA1 immunoreactivity were also observed after CPIP. In the CPIP acute phase, we observed mechanical and cold allodynia; increased levels of tumor necrosis factor-α (hind paw), ischemia-modified albumin (IMA) (serum), protein carbonyl (hind paw and spinal cord), lactate (serum), and 4-hydroxy-2-nonenal (4-HNE, hind paw and spinal cord); and higher myeloperoxidase (MPO) and N-acetyl-β-D-glucosaminidase (NAGase) activities (hind paw). In the CPIP chronic phase, we detected mechanical and cold allodynia and increased levels of IMA (serum), protein carbonyl (hind paw and spinal cord), and 4-HNE (hind paw and spinal cord). TRPA1 antagonism reduced mechanical and cold allodynia 1 and 14 days after CPIP, but no change in TRPA1 immunoreactivity was observed. Different mechanisms underlie acute (inflammation and oxidative stress) and chronic (oxidative stress) phases of CPIP. TRPA1 activation may be relevant for CRPS1/CPIP-induced acute and chronic pain.

  4. Glutaminase Increases in Rat Dorsal Root Ganglion Neurons after Unilateral Adjuvant-Induced Hind Paw Inflammation

    PubMed Central

    Hoffman, E. Matthew; Zhang, Zijia; Schechter, Ruben; Miller, Kenneth E.

    2016-01-01

    Glutamate is a neurotransmitter used at both the peripheral and central terminals of nociceptive primary sensory neurons, yet little is known concerning regulation of glutamate metabolism during peripheral inflammation. Glutaminase (GLS) is an enzyme of the glutamate-glutamine cycle that converts glutamine into glutamate for neurotransmission and is implicated in producing elevated levels of glutamate in central and peripheral terminals. A potential mechanism for increased levels of glutamate is an elevation in GLS expression. We assessed GLS expression after unilateral hind paw inflammation by measuring GLS immunoreactivity (ir) with quantitative image analysis of L4 dorsal root ganglion (DRG) neurons after one, two, four, and eight days of adjuvant-induced arthritis (AIA) compared to saline injected controls. No significant elevation in GLS-ir occurred in the DRG ipsilateral to the inflamed hind paw after one or two days of AIA. After four days AIA, GLS-ir was elevated significantly in all sizes of DRG neurons. After eight days AIA, GLS-ir remained elevated in small (<400 µm2), presumably nociceptive neurons. Western blot analysis of the L4 DRG at day four AIA confirmed the elevated GLS-ir. The present study indicates that GLS expression is increased in the chronic stage of inflammation and may be a target for chronic pain therapy. PMID:26771651

  5. The D1 family dopamine receptor, DopR, potentiates hind leg grooming behavior in Drosophila

    PubMed Central

    Pitmon, E.; Stephens, G.; Parkhurst, S. J.; Wolf, F. W.; Kehne, G.; Taylor, M.

    2016-01-01

    Drosophila groom away debris and pathogens from the body using their legs in a stereotyped sequence of innate motor behaviors. Here, we investigated one aspect of the grooming repertoire by characterizing the D1 family dopamine receptor, DopR. Removal of DopR results in decreased hind leg grooming, as substantiated by quantitation of dye remaining on mutant and RNAi animals vs. controls and direct scoring of behavioral events. These data are also supported by pharmacological results that D1 receptor agonists fail to potentiate grooming behaviors in headless DopR flies. DopR protein is broadly expressed in the neuropil of the thoracic ganglion and overlaps with TH‐positive dopaminergic neurons. Broad neuronal expression of dopamine receptor in mutant animals restored normal grooming behaviors. These data provide evidence for the role of DopR in potentiating hind leg grooming behaviors in the thoracic ganglion of adult Drosophila. This is a remarkable juxtaposition to the considerable role of D1 family dopamine receptors in rodent grooming, and future investigations of evolutionary relationships of circuitry may be warranted. PMID:26749475

  6. Nerve growth factor induced hyperalgesia in the rat hind paw is dependent on circulating neutrophils.

    PubMed

    Bennett, G; al-Rashed, S; Hoult, J R; Brain, S D

    1998-09-01

    The mechanisms by which nerve growth factor (NGF) induces thermal hyperalgesia and neutrophil accumulation have been investigated in the rat. Thermal nociceptive thresholds in rat hind paw were measured as the time taken for paw withdrawal from a heat source and neutrophil accumulation was measured in hind paw and dorsal skin samples using a myeloperoxidase assay. NGF (23-80 pmol intraplantar (i.pl.) injection) induced a significant (P < 0.05, n = 6-16) thermal hyperalgesia at 5 h after injection and significant neutrophil accumulation (P < 0.05, n = 6) was observed with NGF (40 pmol). In dorsal skin, where multiple samples can be assessed, intradermal (i.d.) NGF was 10-30 times less potent than interleukin-1beta in inducing neutrophil accumulation. The 5-lipoxygenase inhibitor ZM230487 (10 nmol co-injected with NGF) significantly attenuated neutrophil accumulation and hyperalgesia induced by NGF; unlike the histamine and 5-hydroxytryptamine antagonists (mepyramine and methysergide) which were without effect at the times measured. Furthermore, depletion of circulating neutrophils (using a rabbit anti-rat neutrophil antibody) abolished NGF induced hyperalgesia. These results indicate that neutrophils, which accumulate in response to a 5-lipoxygenase product, play a crucial role in NGF-induced hyperalgesia.

  7. Limb lengthening in achondroplasia

    PubMed Central

    Chilbule, Sanjay K; Dutt, Vivek; Madhuri, Vrisha

    2016-01-01

    Background: Stature lengthening in skeletal dysplasia is a contentious issue. Specific guidelines regarding the age and sequence of surgery, methods and extent of lengthening at each stage are not uniform around the world. Despite the need for multiple surgeries, with their attendant complications, parents demanding stature lengthening are not rare, due to the social bias and psychological effects experienced by these patients. This study describes the outcome and complications of extensive stature lengthening performed at our center. Materials and Methods: Eight achondroplasic and one hypochondroplasic patient underwent bilateral transverse lengthening for tibiae, humeri and femora. Tibia lengthening was carried out using a ring fixator and bifocal corticotomy, while a monolateral pediatric limb reconstruction system with unifocal corticotomy was used for the femur and humerus. Lengthening of each bone segment, height gain, healing index and complications were assessed. Subgroup analysis was carried out to assess the effect of age and bone segment on the healing index. Results: Nine patients aged five to 25 years (mean age 10.2 years) underwent limb lengthening procedures for 18 tibiae, 10 femora and 8 humeri. Four patients underwent bilateral lengthening of all three segments. The mean length gain for the tibia, femur and humerus was 15.4 cm (100.7%), 9.9 cm (52.8%) and 9.6 cm (77.9%), respectively. Healing index was 25.7, 25.6 and 20.6 days/cm, respectively, for the tibia, femur and humerus. An average of 33.3% height gain was attained. Lengthening of both tibia and femur added to projected height achieved as the 3rd percentile of standard height in three out of four patients. In all, 33 complications were encountered (0.9 complications per segment). Healing index was not affected by age or bone segment. Conclusion: Extensive limb lengthening (more than 50% over initial length) carries significant risk and should be undertaken only after due consideration. PMID

  8. Lipotyphla limb myology comparison.

    PubMed

    Neveu, Pauline; Gasc, Jean-Pierre

    2002-05-01

    Fore- and hindlimb muscles were dissected in four species of Lipotyphla: the western European hedgehog Erinaceus europaeus (Erinaceidae, Erinaceinae); the moonrat Echinosorex gymnura (Erinaceidae, Hylomyinae or Galericinae); the tailless tenrec Tenrec ecaudatus (Tenrecidae, Tenrecinae); and the common European white-toothed shrew Crocidura russula (Soricidae, Soricinae). This work completely reviews the limb musculature of these walking mammals. Twelve myological characters were evaluated in order to disclose phylogenetic relationships. The cladogram obtained supported previous ones based on cranial and dental characters. This study shows that myological characters are valuable in phylogenetic analyses.

  9. Vasospastic Limb Ischemia Presenting Acute and Chronic Limb Ischemia

    PubMed Central

    2014-01-01

    Vasospastic limb ischemia might have been underappreciated compared to vasospasm in other territories such as heart and brain. However, an increasing awareness of this vascular disorder can be translated to an improved patients’ care. Herein, we report a case of vasospasm presenting acute and chronic limb ischemia in four extremities. PMID:24995065

  10. LIMB Demonstration Project Extension

    SciTech Connect

    Not Available

    1989-08-15

    The subject of this report is progress during the quarter for Phase I -- Design and Permitting, Phase II -- Coolside/LIMB Construction, Start-Up and Phase III -- Operation, Data Collection, Reporting and Disposition. Under Phase I, Task 2, Consol Technology Transfer, Consol R D continued to review the status of the Coolside installation and identified construction details which required additional action. Activities in Task 4.0 -- Permitting and Licensing have focused on finalizing a subcontract agreement for trucking the DOE Coolside/LIMB ash to a solid waste landfill. Under Phase II, Task 1, Project Management, purchase orders were placed with two (2) lime suppliers for supplying the specified hydrated lime to be used for the Coolside test program. For Subtask 2.2 -- Sorbent Feed System Installation, the construction and installation of the sorbent feed system has been completed. Under Phase III, Subtask 2.1, Optimization of the Coolside sorbent feed system, the ash recycle system and the caustic injection system were initiated. 3 figs.

  11. LDTK: Limb Darkening Toolkit

    NASA Astrophysics Data System (ADS)

    Parviainen, H.; Aigrain, S.

    2015-11-01

    We present a PYTHON package LDTK that automates the calculation of custom stellar limb-darkening (LD) profiles and model-specific limb-darkening coefficients using the library of PHOENIX-generated specific intensity spectra by Husser et al. The aim of the package is to facilitate analyses requiring custom generated LD profiles, such as the studies of exoplanet transits - especially transmission spectroscopy, where the transit modelling is carried out for custom narrow passbands - eclipsing binaries, interferometry, and microlensing events. First, LDTK can be used to compute custom LD profiles with uncertainties propagated from the uncertainties in the stellar parameter estimates. Secondly, LDTK can be used to estimate the LD-model-specific coefficients with uncertainties for the most common LD models. Thirdly, LDTK can be directly integrated into the log posterior computation of any pre-existing modelling code with minimal modifications. The last approach can be used to constrain the LD model parameter space directly by the LD profile, allowing for the marginalization over the LD parameter space without the need to approximate the constraint from the LD profile using a prior.

  12. The hind wing of the desert locust (Schistocerca gregaria Forskål). I. Functional morphology and mode of operation.

    PubMed

    Wootton, R J; Evans, K E; Herbert, R; Smith, C W

    2000-10-01

    Detailed morphological investigation, mechanical testing and high-speed cinematography and stroboscopic examination of desert locusts, Schistocerca gregaria, in flight show that their hind wings are adapted to deform cyclically and automatically through the wing stroke and that the deformations are subtly dependent on the wings' structure: their shape, venation and vein design and the local properties of the membrane. The insects predominantly fly fast forwards, generating most force on the downstroke, and the hind wings generate extra lift by peeling apart at the beginning of the downstroke and by developing a cambered section during the stroke's translation phase through the 'umbrella effect' - an automatic consequence of the active extension of the wings' expanded posterior fan. Bending experiments indicate that most of the hind wing is more rigid to forces from below than from above and demonstrate that the membrane acts as a stressed skin to stiffen the structure.

  13. Elevated vacuum suspension preserves residual-limb skin health in people with lower-limb amputation: Randomized clinical trial.

    PubMed

    Rink, Cameron; Wernke, Matthew M; Powell, Heather M; Gynawali, Surya; Schroeder, Ryan M; Kim, Jayne Y; Denune, Jeffrey A; Gordillo, Gayle M; Colvin, James M; Sen, Chandan K

    2016-01-01

    A growing number of clinical trials and case reports support qualitative claims that use of an elevated vacuum suspension (EVS) prosthesis improves residual-limb health on the basis of self-reported questionnaires, clinical outcomes scales, and wound closure studies. Here, we report first efforts to quantitatively assess residual-limb circulation in response to EVS. Residual-limb skin health and perfusion of people with lower-limb amputation (N = 10) were assessed during a randomized crossover study comparing EVS with nonelevated vacuum suspension (control) over a 32 wk period using noninvasive probes (transepidermal water loss, laser speckle imaging, transcutaneous oxygen measurement) and functional hyperspectral imaging approaches. Regardless of the suspension system, prosthesis donning decreased perfusion in the residual limb under resting conditions. After 16 wk of use, EVS improved residual-limb oxygenation during treadmill walking. Likewise, prosthesis-induced reactive hyperemia was attenuated with EVS following 16 wk of use. Skin barrier function was preserved with EVS but disrupted after control socket use. Taken together, outcomes suggest chronic EVS use improves perfusion and preserves skin barrier function in people with lower-limb amputation.

  14. Niacin promotes revascularization and recovery of limb function in diet-induced obese mice with peripheral ischemia.

    PubMed

    Pang, Dominic K T; Nong, Zengxuan; Sutherland, Brian G; Sawyez, Cynthia G; Robson, Debra L; Toma, Jelena; Pickering, J Geoffrey; Borradaile, Nica M

    2016-06-01

    Niacin can reduce vascular disease risk in individuals with metabolic syndrome, but in light of recent large randomized controlled trials outcomes, its biological actions and clinical utility remain controversial. Niacin can improve endothelial function, vascular inflammation, and vascular regeneration, independent of correcting dyslipidemia, in various lean rodent models of vascular injury. Here, we tested whether niacin could directly improve endothelial cell angiogenic function during combined exposure to excess fatty acids and hypoxia, and whether intervention with niacin during continued feeding of western diet could improve revascularization and functional recovery in obese, hyperlipidemic mice with peripheral ischemia. Treatment with niacin (10 μmol/L) increased human microvascular endothelial cell angiogenic function during exposure to high fatty acids and hypoxia (2% oxygen), as determined by tube formation on Matrigel. To assess revascularization in vivo, we used western diet-induced obese mice with unilateral hind limb femoral artery ligation and excision. Treatment for 14 days postinjury with once daily i.p. injections of a low dose of niacin (50 mg/kg) improved recovery of hind limb use, in association with enhanced revascularization and decreased inflammation of the tibialis anterior muscle. These effects were concomitant with decreased plasma triglycerides, but not increased plasma apoAI. Thus, niacin improves endothelial tube formation under lipotoxic and hypoxic conditions, and moreover, promotes revascularization and functional hind limb recovery following ischemic injury in diet-induced obese mice with hyperlipidemia. These data may have implications for niacin therapy in the treatment of peripheral ischemic vascular disease associated with metabolic syndrome.

  15. Evaluation of Limb-Girdle Muscular Dystrophy

    ClinicalTrials.gov

    2014-03-06

    Becker Muscular Dystrophy; Limb-Girdle Muscular Dystrophy, Type 2A (Calpain-3 Deficiency); Limb-Girdle Muscular Dystrophy, Type 2B (Miyoshi Myopathy, Dysferlin Deficiency); Limb-Girdle Muscular Dystrophy, Type 2I (FKRP-deficiency)

  16. Complete mitochondrial genome of the sixblotch hind Cephalopholis sexmaculata (Pisces: Perciformes).

    PubMed

    Hsiao, Sheng-Tai; Chen, Kao-Sung; Tseng, Chen-Te; Wu, Chi-Lun

    2016-01-01

    The complete mitogenome of the sixblotch hind, Cephalopholis sexmaculata was presented in this study. This mitochondrial genome consists of 16,589 bp, with 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA genes, and a noncoding control region (CR), and its gene arrangement is identical to most vertebrates. The overall base composition of the heavy strand is A, 29.35%; G, 16.08%; C, 28.56%; and T, 26.01%. The COI gene started with GTG codon and the ATP6 gene started with CTG codon. The complete mitogenomic data may provide informative for further phylogenetic approach of species of Cephalopholis and related genera belong to the Epinephelidae groupers.

  17. Determining the size of American alligators using hind-foot track length

    USGS Publications Warehouse

    Wilkinson, Philip M.; Rice, Kenneth G.

    2000-01-01

    Size distribution information is useful for crocodilian management, but can be hard to obtain. Indirect and less costly demographic inferences made from track measurements may be valuable for management decisions. We related hind-foot lengths (HF) with total length (TL) to determine if we could indirectly assess alligator size using track length. Regression showed that HF was an excellent predictor (F1,246= 15722.9, R2=0.98, P<0.01) of TL and track length was an exceptional predictor of HF (F1,14=7520.3, R2= 1.00, P<0.01). The correlation between track length and HF length also was significant (N= 15, r=0.99, P <0.01). Thus, alligator size can be accurately estimated from measures of track length at sites where capture and direct measurement is impractical.

  18. Peripheral muscle dysfunction in COPD: lower limbs versus upper limbs.

    PubMed

    Miranda, Eduardo Foschini; Malaguti, Carla; Corso, Simone Dal

    2011-01-01

    In patients with COPD, the degree of functional impairment appears to differ between the upper and lower limbs. Significant dyspnea and fatigue have been reported by these patients when performing tasks with unsupported upper limbs and two mechanisms have been proposed to explain this fact: neuromechanical dysfunction of respiratory muscles; and changes in lung volume during such activities. The neuromechanical dysfunction seen in COPD patients during this type of exercise is related to changes in the breathing pattern, as well as to the simultaneity of afferent and efferent muscle stimuli, resulting in respiratory muscle asynchrony. In addition, the increased ventilation during upper limb exercise in patients with COPD leads to dynamic hyperinflation at different workloads. During lower limb exercises, the strength and endurance of the quadriceps muscle is lower in COPD patients than in healthy subjects. This could by explained by abnormal muscle metabolism (decreased aerobic capacity), dependence on glycolytic metabolism, and rapid accumulation of lactate during exercise. In comparison with lower limb exercises, upper limb exercises result in higher metabolic and ventilatory demands, as well as in a more intense sensation of dyspnea and greater fatigue. Because there are differences between the upper and lower limb muscles in terms of the morphological and functional adaptations in COPD patients, specific protocols for strength training and endurance should be developed and tested for the corresponding muscle groups.

  19. Multiscale models for vertebrate limb development.

    PubMed

    Newman, Stuart A; Christley, Scott; Glimm, Tilmann; Hentschel, H G E; Kazmierczak, Bogdan; Zhang, Yong-Tao; Zhu, Jianfeng; Alber, Mark

    2008-01-01

    Dynamical systems in which geometrically extended model cells produce and interact with diffusible (morphogen) and nondiffusible (extracellular matrix) chemical fields have proved very useful as models for developmental processes. The embryonic vertebrate limb is an apt system for such mathematical and computational modeling since it has been the subject of hundreds of experimental studies, and its normal and variant morphologies and spatiotemporal organization of expressed genes are well known. Because of its stereotypical proximodistally generated increase in the number of parallel skeletal elements, the limb lends itself to being modeled by Turing-type systems which are capable of producing periodic, or quasiperiodic, arrangements of spot- and stripe-like elements. This chapter describes several such models, including, (i) a system of partial differential equations in which changing cell density enters into the dynamics explicitly, (ii) a model for morphogen dynamics alone, derived from the latter system in the "morphostatic limit" where cell movement relaxes on a much slower time-scale than cell differentiation, (iii) a discrete stochastic model for the simplified pattern formation that occurs when limb cells are placed in planar culture, and (iv) several hybrid models in which continuum morphogen systems interact with cells represented as energy-minimizing mesoscopic entities. Progress in devising computational methods for handling 3D, multiscale, multimodel simulations of organogenesis is discussed, as well as for simulating reaction-diffusion dynamics in domains of irregular shape.

  20. Simulation of Upper Limb Movements

    NASA Astrophysics Data System (ADS)

    Uherčík, Filip; Hučko, Branislav

    2011-12-01

    The paper deals with controlling an upper limb prosthesis based on the measurement of myoelectric signals (MES) while drinking. MES signals have been measured on healthy limbs to obtain the same response for the prosthesis. To simulate the drinking motion of a healthy upper limb, the program ADAMS was used, with all degrees of freedom and a hand after trans-radial amputation with an existing hand prosthesis. Modification of the simulation has the exact same logic of control, where the muscle does not have to be strenuous all the time, but it is the impulse of the muscle which drives the motor even though the impulse disappears and passed away.

  1. Management of Major Limb Injuries

    PubMed Central

    Langer, Vijay

    2014-01-01

    Management of major limb injuries is a daunting challenge, especially as many of these patients have severe associated injuries. In trying to save life, often the limb is sacrificed. The existing guidelines on managing such trauma are often confusing. There is scope to lay down such protocols along with the need for urgent transfer of such patients to a multispecialty center equipped to salvage life and limb for maximizing outcome. This review article comprehensively deals with the issue of managing such major injuries. PMID:24511296

  2. Prevalence and Characteristics of Phantom Limb Pain and Residual Limb Pain in the Long Term after Upper Limb Amputation

    ERIC Educational Resources Information Center

    Desmond, Deirdre M.; MacLachlan, Malcolm

    2010-01-01

    This study aims to describe the prevalence and characteristics of phantom limb pain and residual limb pain after upper limb amputation. One-hundred and forty-one participants (139 males; mean age 74.8 years; mean time since amputation 50.1 years) completed a self-report questionnaire assessing residual and phantom limb pain experience. Prevalence…

  3. Enriched housing enhances recovery of limb placement ability and reduces aggrecan-containing perineuronal nets in the rat somatosensory cortex after experimental stroke.

    PubMed

    Madinier, Alexandre; Quattromani, Miriana Jlenia; Sjölund, Carin; Ruscher, Karsten; Wieloch, Tadeusz

    2014-01-01

    Stroke causes life long disabilities where few therapeutic options are available. Using electrical and magnetic stimulation of the brain and physical rehabilitation, recovery of brain function can be enhanced even late after stroke. Animal models support this notion, and housing rodents in an enriched environment (EE) several days after experimental stroke stimulates lost brain function by multisensory mechanisms. We studied the dynamics of functional recovery of rats with a lesion to the fore and hind limb motor areas induced by photothrombosis (PT), and with subsequent housing in either standard (STD) or EE. In this model, skilled motor function is not significantly enhanced by enriched housing, while the speed of recovery of sensori-motor function substantially improves over the 9-week study period. In particular, this stroke lesion completely obliterates the fore and hind limb placing ability when visual and whisker guidance is prevented, a deficit that persists for up to 9 weeks of recovery, but that is markedly restored within 2 weeks by enriched housing. Enriched housing after stroke also leads to a significant loss of perineuronal net (PNN) immunoreactivity; detection of aggrecan protein backbone with AB1031 antibody was decreased by 13-22%, and labelling of a glycan moiety of aggrecan with Cat-315 antibody was reduced by 25-30% in the peri-infarct area and in the somatosensory cortex, respectively. The majority of these cells are parvalbumin/GABA inhibitory interneurons that are important in sensori-information processing. We conclude that damage to the fore and hind limb motor areas provides a model of loss of limb placing response without visual guidance, a deficit also seen in more than 50% of stroke patients. This loss is amenable to recovery induced by multiple sensory stimulation and correlates with a decrease in aggrecan-containing PNNs around inhibitory interneurons. Modulating the PNN structure after ischemic damage may provide new therapies

  4. Scales

    ScienceCinema

    Murray Gibson

    2016-07-12

    Musical scales involve notes that, sounded simultaneously (chords), sound good together. The result is the left brain meeting the right brain — a Pythagorean interval of overlapping notes. This synergy would suggest less difference between the working of the right brain and the left brain than common wisdom would dictate. The pleasing sound of harmony comes when two notes share a common harmonic, meaning that their frequencies are in simple integer ratios, such as 3/2 (G/C) or 5/4 (E/C).

  5. Scales

    SciTech Connect

    Murray Gibson

    2007-04-27

    Musical scales involve notes that, sounded simultaneously (chords), sound good together. The result is the left brain meeting the right brain — a Pythagorean interval of overlapping notes. This synergy would suggest less difference between the working of the right brain and the left brain than common wisdom would dictate. The pleasing sound of harmony comes when two notes share a common harmonic, meaning that their frequencies are in simple integer ratios, such as 3/2 (G/C) or 5/4 (E/C).

  6. Limb displacement and brightness seismology

    NASA Astrophysics Data System (ADS)

    Emilio, Marcelo; Cunnyngham, Ian; Kuhn, Jeff; Mehret, Leandro; Bush, Rock; Scholl, Isabelle

    2015-08-01

    The Helioseismic and Magnetic Imager (HMI) abord the Solar Dynamics Observatory (SDO) has been used to obtain the most sensitive spectrally resolved observation of individual p-modes at the extreme solar limb. Such oscillation observations of the limb displacement and brightness for some spatial and temporal regimes are even competitive in signal-to-noise to full-disk doppler measurements of the p-mode spectrum. Limb measurements of 5-min p-modes, while having many similarities to full-disk doppler observations, have significantly different sensitivities to the solar rotation and the 5-min mode solar atmospheric structure. These may provide information about the solar structure which is complementary to full-disk measurements. In this work we present results from Individual spherical harmonic p-modes that were detected around solar limb with amplitudes at the micro-arcsecond level.

  7. Atmospheric Waves in MGS TES Limb-Scan Temperatures

    NASA Astrophysics Data System (ADS)

    Banfield, D. J.; Conrath, B. J.; Kaelberer, M. S.; Smith, M. D.

    2014-12-01

    We have quantified the expression of the lowest zonal wavenumber forced and traveling waves evident in the MGS TES Limb-scan temperature retrievals. The results were found to be broadly consistent with the vertically limited and vertically smoothed (although better spatially and temporally resolved) results from the more numerous MGS TES nadir temperature retrievals (e.g., Wilson et al., 2002, Banfield et al., 2003, Banfield et al. 2004). The MGS TES Limb-scan retrievals were used to compute a measure of the Diurnal Kelvin Waves (DK1 And DK2). The structures revealed are consistent with theory, and indicative of the importance of these wave modes at aerobraking altitudes (e.g., Wilson 2000, Forbes & Hagan, 2000, Wilson, 2002). The stationary wave structures revealed in the limb retrievals show the winter polar waves in both hemispheres continue to have their maximum amplitude aligned along the polar vortices, even for altitudes above 4 scale heights. The phase structures in and above the stationary waves revealed by the limb retrievals are consistent with the nadir results and the heat fluxes computed in those analyses (Banfield et al., 2003). The winter polar vortex zonal wavenumber 1 traveling waves continue along the edge of the polar vortex, reaching to 6 or more scale heights altitude in the northern winter and extending between 60N and the north pole. The peak amplitudes for these zonal wavenumber 1 traveling waves were found to lie at about 4 scale heights altitude. The limb retrievals revealed more clear evidence of a northern fall equinoctial global traveling wave mode having expression not only in the mid-latitudes in both hemispheres, but also out of phase above the tropics at altitudes above 4 scale heights. Zonal wavenumber 2 & 3 traveling waves could not be reliably retrieved from the limb retrievals.

  8. Differentiation of cartilaginous anlage in entire embryonic mouse limbs cultured in a rotating bioreactor.

    NASA Astrophysics Data System (ADS)

    Duke, P.; Oakley, C.; Montufar-Solis, D.

    The embryonic mammalian limb is sensitive both in vivo and in vitro to changes in gravitational force. Hypergravity of centrifugation and microgravity of space decreased size of elements due to precocious or delayed chondrogenesis respectively. In recapitulating spaceflight experiments, premetatarsals were cultured in suspension in a low stress, low sheer rotating bioreactor, and found to be shorter than those cultured in standard culture dishes, and cartilage development was delayed. This study only measured length of the metatarsals, and did not account for possible changes in width and/or in form of the skeletal elements. Shorter cartilage elements in limbbuds cultured in the bioreactor may be due to the ability of the system to reproduce a more in vivo 3D shape than traditional organ cultures. Tissues subjected to traditional organ cultures become flattened by their own weight, attachment to the filter, and restrictions imposed by nutrient diffusion. The purpose of the current experiment was to determine if entire limb buds could be successfully cultured in the bioreactor, and to compare the effects on 3D shape with that of culturing in a culture dish system. Fore and hind limbs from E11-E13 ICR mouse embryos were placed either in the bioreactor, in Trowell culture, or fixed as controls. Limbbuds were cultured for six days, fixed, and processed either as whole mounts or embedded for histology. Qualitative analysis revealed that the Trowell culture specimens were flattened, while bioreactor culture specimens had a more in vivo-like 3D limb shape. Sections of limbbuds from both types of cultures had excellent cartilage differentiation, with apparently more cell maturation, and hypertrophy in the specimens cultured in the bioreactor. Morphometric quantitation of the cartilaginous elements for comparisons of the two culture systems was complicated due to some limb buds fusing together during culture. This problem was especially noticeable in the younger limbs, and

  9. Pediatric limb differences and amputations.

    PubMed

    Le, Joan T; Scott-Wyard, Phoebe R

    2015-02-01

    Congenital limb differences are uncommon birth defects that may go undetected even with prenatal screening ultrasound scans and often go undetected until birth. For children with congenital limb differences, a diagnostic evaluation should be done to rule out syndromes involving other organ systems or known associations. The most common etiology of acquired amputation is trauma. Postamputation complications include pain and terminal bony overgrowth. A multidisciplinary approach to management with the child and family can lead to a successful, functional, and fulfilling life.

  10. Revising Australian Pristomerus (Hymenoptera, Ichneumonidae, Cremastinae): species with a tooth on the hind femur.

    PubMed

    Klopfstein, Seraina

    2016-09-15

    The Australian insect fauna is among the least-well studied in the world, and conservative estimates state that 75% of the species still await description. In the more species-rich groups, this percentage might be even larger, which is certainly the case in parasitoid wasps which have received very little attention by taxonomists. The genus Pristomerus of the family Ichneumonidae is distributed worldwide, with most species found in the tropics. Its members attack concealed larvae of small Lepidoptera, and several species are used in biocontrol. Five species have been reported from Australia, all of them endemic, but many more undescribed species are present in various collections.        I here revise Australian Pristomerus, focussing on the species that bear a tooth on the ventral side of the hind femur. Twenty-two species are recorded, 19 of which are described as new: Pristomerus australiensis n. sp., P. bertschmanni n. sp., P. callitrinus n. sp., P. dundeei n. sp., P. flavicephalus n. sp., P. fourecksensis n. sp., P. gracilis n. sp., P. kakaduensis n. sp., P. laetus n. sp., P. luculentus n. sp., P. lunatus n. sp., P. mangiferus n. sp., P. merus n. sp., P. nedkellyi n. sp., P. pellicius n. sp., P. periculosus n. sp., P. stellatus n. sp., P. tenebrosus n. sp., and P. venustus n. sp. A dichotomous key and an online interactive key to the known Australian species with a tooth on the hind femur are provided, including photographs of all the species.        The origin of the considerable number of Australian Pristomerus species remains unclear. They might represent Southern relict elements with affinities to South American taxa, or their ancestors might have immigrated from the Paleotropics in more recent times; this question can only be solved with a dated phylogeny of the genus. However, support for a Palaeotropic origin of at least a good portion of the taxa comes from their current distribution, as the Australian Pristomerus are found to be most

  11. Influence of adjustments to amputation and artificial limb on quality of life in patients following lower limb amputation.

    PubMed

    Sinha, Richa; van den Heuvel, Wim J A; Arokiasamy, Perianayagam; van Dijk, Jitse P

    2014-03-01

    The objectives of this study are to investigate the relationship between adjustments to amputation and artificial limb, and quality of life (QoL), and to analyse the influence of sociodemographic, medical and amputation-related factors on this relationship. Patients with unilateral and noncongenital lower limb amputation who were using artificial limb were interviewed (n=368) using structured questionnaires. The Trinity Amputation and Prosthesis Experience Scales (TAPES) were used to assess adjustments to amputation and artificial limb and the MOS Short-Form Health Survey (SF-36) was used to assess the physical (PCS) and mental (MCS) component summary of QoL. Absence of comorbidity and residual stump pain, being employed, young age, less functional restriction, being more adjusted to limitation, increased social adjustment and less restriction in athletic activity were related to better PCS scores. Absence of comorbidity and phantom limb pain, nonuse of assistive device, being more adjusted to limitation, increased social adjustment and being less functionally restricted were related to higher MCS scores. Comorbidity had a modifying effect on both PCS and MCS scores. In addition, age, being employed and residual stump pain had a modifying influence on PCS, whereas assistive device use and phantom limb pain had a modifying influence on MCS. Our findings show that TAPES subscales have a modifying effect on the associations between several background (sociodemographic and amputation characteristics) and QoL (PCS and MCS). This indicates that adjustments to amputation and artificial limb are the key determinants of QoL in individuals following lower limb amputation.

  12. Mice Hemizygous for a Pathogenic Mitofusin-2 Allele Exhibit Hind Limb/Foot Gait Deficits and Phenotypic Perturbations in Nerve and Muscle

    PubMed Central

    Bannerman, Peter; Burns, Travis; Xu, Jie; Miers, Laird; Pleasure, David

    2016-01-01

    Charcot-Marie-Tooth disease type 2A (CMT2A), the most common axonal form of hereditary sensory motor neuropathy, is caused by mutations of mitofusin-2 (MFN2). Mitofusin-2 is a GTPase required for fusion of mitochondrial outer membranes, repair of damaged mitochondria, efficient mitochondrial energetics, regulation of mitochondrial-endoplasmic reticulum calcium coupling and axonal transport of mitochondria. We knocked T105M MFN2 preceded by a loxP-flanked STOP sequence into the mouse Rosa26 locus to permit cell type-specific expression of this pathogenic allele. Crossing these mice with nestin-Cre transgenic mice elicited T105M MFN2 expression in neuroectoderm, and resulted in diminished numbers of mitochondria in peripheral nerve axons, an alteration in skeletal muscle fiber type distribution, and a gait abnormality. PMID:27907123

  13. Low-Level Laser Therapy (904 nm) Counteracts Motor Deficit of Mice Hind Limb following Skeletal Muscle Injury Caused by Snakebite-Mimicking Intramuscular Venom Injection

    PubMed Central

    Vieira, Willians Fernando; Kenzo-Kagawa, Bruno; Cogo, José Carlos; da Cruz-Höfling, Maria Alice

    2016-01-01

    Myotoxins present in Bothrops venom disrupt the sarcolemma of muscle fibers leading to the release of sarcoplasmic proteins and loss of muscle homeostasis. Myonecrosis and tissue anoxia induced by vascularization impairment can lead to amputation or motor functional deficit. The objective of this study was to investigate the dynamic behavior of motor function in mice subjected to injection of Bothrops jararacussu venom (Bjssu) and exposed to low-level laser therapy (LLLT). Male Swiss mice received Bjssu injection (830 μg/kg) into the medial portion of the right gastrocnemius muscle. Three hours later the injected region was irradiated with diode semiconductor Gallium Arsenide (GaAs– 904 nm, 4 J/cm²) laser following by irradiation at 24, 48 and 72 hours. Saline injection (0.9% NaCl) was used as control. Gait analysis was performed 24 hours before Bjssu injection and at every period post-Bjssu using CatWalk method. Data from spatiotemporal parameters Stand, Maximum Intensity, Swing, Swing Speed, Stride Length and Step Cycle were considered. The period of 3 hours post venom-induced injury was considered critical for all parameters evaluated in the right hindlimb. Differences (p<0.05) were concentrated in venom and venom + placebo laser groups during the 3 hours post-injury period, in which the values of stand of most animals were null. After this period, the gait characteristics were re-established for all parameters. The venom + laser group kept the values at 3 hours post-Bjssu equal to that at 24 hours before Bjssu injection indicating that the GaAs laser therapy improved spatially and temporally gait parameters at the critical injury period caused by Bjssu. This is the first study to analyze with cutting edge technology the gait functional deficits caused by snake envenoming and gait gains produced by GaAs laser irradiation. In this sense, the study fills a gap on the field of motor function after laser treatment following snake envenoming. PMID:27392016

  14. Experimental measurements of the temperature variation along artery-vein pairs from 200 to 1000 microns diameter in rat hind limb.

    PubMed

    He, Qinghong; Zhu, Liang; Lemons, Daniel E; Weinbaum, Sheldon

    2002-12-01

    Theoretical studies have indicated that a significant fraction of all blood-tissue heat transfer occurs in artery-vein pairs whose arterial diameter varies between 200 and 1000 microns. In this study, we have developed a new in vivo technique in which it is possible to make the first direct measurements of the countercurrent thermal equilibration that occurs along thermally significant vessels of this size. Fine wire thermocouples were attached by superglue to the femoral arteries and veins and their subsequent branches in rats and the axial temperature variation in each vessel was measured under different physiological conditions. Unlike the blood vessels < 200 microns in diameter, where the blood rapidly equilibrates with the surrounding tissue, we found that the thermal equilibration length of blood vessels between 200 microns and 1000 microns in diameter is longer than or at least equivalent to the vessel length. It is shown that the axial arterial temperature decays from 44% to 76% of the total core-skin temperature difference along blood vessels of this size, and this decay depends strongly on the local blood perfusion rate and the vascular geometry. Our experimental measurements also showed that the SAV venous blood recaptured up to 41% of the total heat released from its countercurrent artery under normal conditions. The contribution of countercurrent heat exchange is significantly reduced in these larger thermally significant vessels for hyperemic conditions as predicted by previous theoretical analyses. Results from this study, when combined with previous analyses of vessel pairs less than 200 microns diameter, enable one estimate the arterial supply temperature and the correction coefficient in the modified perfusion source term developed by the authors.

  15. Low-Level Laser Therapy (904 nm) Counteracts Motor Deficit of Mice Hind Limb following Skeletal Muscle Injury Caused by Snakebite-Mimicking Intramuscular Venom Injection.

    PubMed

    Vieira, Willians Fernando; Kenzo-Kagawa, Bruno; Cogo, José Carlos; Baranauskas, Vitor; Cruz-Höfling, Maria Alice da

    2016-01-01

    Myotoxins present in Bothrops venom disrupt the sarcolemma of muscle fibers leading to the release of sarcoplasmic proteins and loss of muscle homeostasis. Myonecrosis and tissue anoxia induced by vascularization impairment can lead to amputation or motor functional deficit. The objective of this study was to investigate the dynamic behavior of motor function in mice subjected to injection of Bothrops jararacussu venom (Bjssu) and exposed to low-level laser therapy (LLLT). Male Swiss mice received Bjssu injection (830 μg/kg) into the medial portion of the right gastrocnemius muscle. Three hours later the injected region was irradiated with diode semiconductor Gallium Arsenide (GaAs- 904 nm, 4 J/cm²) laser following by irradiation at 24, 48 and 72 hours. Saline injection (0.9% NaCl) was used as control. Gait analysis was performed 24 hours before Bjssu injection and at every period post-Bjssu using CatWalk method. Data from spatiotemporal parameters Stand, Maximum Intensity, Swing, Swing Speed, Stride Length and Step Cycle were considered. The period of 3 hours post venom-induced injury was considered critical for all parameters evaluated in the right hindlimb. Differences (p<0.05) were concentrated in venom and venom + placebo laser groups during the 3 hours post-injury period, in which the values of stand of most animals were null. After this period, the gait characteristics were re-established for all parameters. The venom + laser group kept the values at 3 hours post-Bjssu equal to that at 24 hours before Bjssu injection indicating that the GaAs laser therapy improved spatially and temporally gait parameters at the critical injury period caused by Bjssu. This is the first study to analyze with cutting edge technology the gait functional deficits caused by snake envenoming and gait gains produced by GaAs laser irradiation. In this sense, the study fills a gap on the field of motor function after laser treatment following snake envenoming.

  16. A gigantic new dinosaur from Argentina and the evolution of the sauropod hind foot.

    PubMed

    González Riga, Bernardo J; Lamanna, Matthew C; Ortiz David, Leonardo D; Calvo, Jorge O; Coria, Juan P

    2016-01-18

    Titanosauria is an exceptionally diverse, globally-distributed clade of sauropod dinosaurs that includes the largest known land animals. Knowledge of titanosaurian pedal structure is critical to understanding the stance and locomotion of these enormous herbivores and, by extension, gigantic terrestrial vertebrates as a whole. However, completely preserved pedes are extremely rare among Titanosauria, especially as regards the truly giant members of the group. Here we describe Notocolossus gonzalezparejasi gen. et sp. nov. from the Upper Cretaceous of Mendoza Province, Argentina. With a powerfully-constructed humerus 1.76 m in length, Notocolossus is one of the largest known dinosaurs. Furthermore, the complete pes of the new taxon exhibits a strikingly compact, homogeneous metatarsus--seemingly adapted for bearing extraordinary weight--and truncated unguals, morphologies that are otherwise unknown in Sauropoda. The pes underwent a near-progressive reduction in the number of phalanges along the line to derived titanosaurs, eventually resulting in the reduced hind foot of these sauropods.

  17. A gigantic new dinosaur from Argentina and the evolution of the sauropod hind foot

    NASA Astrophysics Data System (ADS)

    González Riga, Bernardo J.; Lamanna, Matthew C.; Ortiz David, Leonardo D.; Calvo, Jorge O.; Coria, Juan P.

    2016-01-01

    Titanosauria is an exceptionally diverse, globally-distributed clade of sauropod dinosaurs that includes the largest known land animals. Knowledge of titanosaurian pedal structure is critical to understanding the stance and locomotion of these enormous herbivores and, by extension, gigantic terrestrial vertebrates as a whole. However, completely preserved pedes are extremely rare among Titanosauria, especially as regards the truly giant members of the group. Here we describe Notocolossus gonzalezparejasi gen. et sp. nov. from the Upper Cretaceous of Mendoza Province, Argentina. With a powerfully-constructed humerus 1.76 m in length, Notocolossus is one of the largest known dinosaurs. Furthermore, the complete pes of the new taxon exhibits a strikingly compact, homogeneous metatarsus—seemingly adapted for bearing extraordinary weight—and truncated unguals, morphologies that are otherwise unknown in Sauropoda. The pes underwent a near-progressive reduction in the number of phalanges along the line to derived titanosaurs, eventually resulting in the reduced hind foot of these sauropods.

  18. HindIII polymorphism in the human c-sis proto-oncogene

    SciTech Connect

    Fourney, R.M.; Dietrich, K.D.; Aubin, R.A.; Paterson, M.C. )

    1988-08-25

    The 2.0 kb BamH1 restriction fragment corresponding to a cDNA insert encoding the human c-sis PDGF A chain and nucleotide sequences homologous to the v-sis gene was isolated from plasmid pSM-1. An identical polymorphism was noted using the 1.2 kb PstI fragment or the 1.0 kb PstI/XbaI fragment isolated from the v-sis sequence subcloned in the plasmid pV-sis. HindIII identifies a single bi-allelic polymorphism with bands at 22.6 kb and 19.4 kb. Co-dominant segregation was demonstrated in 1 family. This polymorphism is not easily detected unless the restricted DNA is separated on 0.6-0.8% agarose gels. Resolution was optimal if gels were run until the bromophenol blue tracking dye had migrated 14 cm from the origin and Southern blotting was performed under alkaline conditions.

  19. A gigantic new dinosaur from Argentina and the evolution of the sauropod hind foot

    PubMed Central

    González Riga, Bernardo J.; Lamanna, Matthew C.; Ortiz David, Leonardo D.; Calvo, Jorge O.; Coria, Juan P.

    2016-01-01

    Titanosauria is an exceptionally diverse, globally-distributed clade of sauropod dinosaurs that includes the largest known land animals. Knowledge of titanosaurian pedal structure is critical to understanding the stance and locomotion of these enormous herbivores and, by extension, gigantic terrestrial vertebrates as a whole. However, completely preserved pedes are extremely rare among Titanosauria, especially as regards the truly giant members of the group. Here we describe Notocolossus gonzalezparejasi gen. et sp. nov. from the Upper Cretaceous of Mendoza Province, Argentina. With a powerfully-constructed humerus 1.76 m in length, Notocolossus is one of the largest known dinosaurs. Furthermore, the complete pes of the new taxon exhibits a strikingly compact, homogeneous metatarsus—seemingly adapted for bearing extraordinary weight—and truncated unguals, morphologies that are otherwise unknown in Sauropoda. The pes underwent a near-progressive reduction in the number of phalanges along the line to derived titanosaurs, eventually resulting in the reduced hind foot of these sauropods. PMID:26777391

  20. Protein synthesis rates in atrophied gastrocnemius muscles after limb immobilization

    NASA Technical Reports Server (NTRS)

    Tucker, K. R.; Seider, M. J.; Booth, F. W.

    1981-01-01

    Noting that protein synthesis declines in the gastrocnemius 6 hr after immobilization, the study sought to detect an increase of protein synthesis when the limb was freed, and to examine the effects of exercise on the rate of increase. Rats were used as subjects, with their hind legs in plaster of Paris in plantar flexion to eliminate strain on the gastrocnemius. Periods of immobilization were varied and samples of blood from the muscle were taken to track protein synthesis rates for different groups in immobilization and exercise regimens (running and weightlifting). Synthesis rates declined 3.6% during time in the cast, then increased 6.3%/day after the casts were removed. Both running and weightlifting were found to increase the fractional rate of protein formation in the gastrocnemius muscle when compared with contralateral muscles that were not exercised and were used as controls, suggesting that the mechanism controlling protein synthesis in skeletal muscles is rapidly responsive to changes in muscular contractile activity.

  1. Influence of level of nutrition during late pregnancy on reproductive productivity of red deer (2) Adult hinds gestating wapitixred deer crossbred calves.

    PubMed

    Asher, G W; Scott, I C; O'Neill, K T; Littlejohn, R P

    2005-04-01

    The present study aimed to relate feed intake of red deer hinds in the later stages of gestating wapitixred deer crossbred foetuses on dam body condition, gestation length, birth weight and calf growth. Multiparous hinds (N=18) conceiving at known dates to either wapiti (n=12) or red deer (n=6) sires were housed in individual pens from days 150-220 of pregnancy, during which time they were offered either ad libitum access to pelletised rations (n=6 crossbred-bearing hinds [HH] and n=6 red deer-bearing hinds [RH]) or a restricted offer (n=6 crossbred-bearing hinds [HL]) set at 70% of the average ad libitum intake of HH hind in the previous week. Hinds were returned to pasture at day 220 and calving was closely monitored. Liveweights, body condition score (BCS), and lactation score (LS) of hinds were recorded weekly from day 130 of pregnancy until calves were weaned at 12 weeks of age. Calves were tagged and weighed at birth, and subsequently weighed at 7 and 12 weeks of age. HH and RH hinds exhibited similar patterns and levels of MEI/kg0.75, which peaked at 7.8 MJME/kg0.75 at day 220. HL hinds peaked at approximately 5 MJME/kg0.75 and showed significantly lower rates of liveweight gain during pregnancy. Interestingly, both crossbred-bearing groups initiated mammary development in advance of the RH hinds. While there were significant effects of foetal genotype on mean gestation length (239 days versus 234 days for crossbred versus red deer) and mean birth weight (14.5 kg versus 10 kg), the nutritional contrast for gestation length of crossbred-bearing hinds (i.e. HH versus HL) was not significant but approached significance for birth weight (14.5 kg versus 11.9 kg; P=0.06). Regression analysis revealed weak relationships between changes in hind liveweight and gestation length (P>0.05) but a significant relationship with birth weight (P<0.05). However, change in hind BCS was significantly related to both gestation length and birth weight. Crossbred calves reared by

  2. The effects of topical oxygen therapy on equine distal limb dermal wound healing

    PubMed Central

    Tracey, Alexandra K.; Alcott, Cody J.; Schleining, Jennifer A.; Safayi, Sina; Zaback, Peter C.; Hostetter, Jesse M.; Reinertson, Eric L.

    2014-01-01

    Topical oxygen therapy (TOT) has been used in human medicine to promote healing in chronic wounds. To test the efficacy and safety of TOT in horses, an experimental wound model was created by making 1 standardized dermal wound on each limb of 4 healthy horses (n = 16). Each wound was fitted with an oxygen delivery cannula and covered with a bandage. One limb of each front and hind pair was randomly assigned to the treatment group (fitted with an oxygen concentrator device), with the contralateral limb assigned to the control group (no device). Wound area, epithelial area, and contraction were measured every 3 to 4 d. Biopsy samples and culture swabs were taken on days 16 and 32 to evaluate angiogenesis, fibroplasia, epithelial hyperplasia, inflammation and bacterial growth. Mean healing time in treated wounds (45 d, range: 38 to 52 d) was not significantly different from that in the paired control wounds (50 d, range: 38 to 62 d). Topical oxygen therapy had little effect on dermal wound healing in this experimental wound model in healthy horses. PMID:25477541

  3. Cross-limb vascular shunting for major limb replantation.

    PubMed

    Lee, Yao-Chou; Lee, Jing-Wei

    2009-02-01

    In the management of traumatic major limb amputation, rapid re-establishment of circulation to the amputated part is imperative so as to prevent complications related to reperfusion injury, especially for those already suffering from prolonged ischemia. A temporary, extra-anatomic cross limb shunting with infusion lines can be used to perfuse the amputated part almost instantaneously. This allows the surgeon to carry out skeletal fixation and other reparative works in an unhurried manner. The cannulation site is targeted at intact vessels far away from the injury zone, obviating the need to explore and handle traumatized vessels at the mangled stump ends, thus greatly simplifying and expediting the revascularization process. Such a method had been successfully applied in 2 young people suffering traumatic arm amputation and thigh amputation, respectively. We suggested that such a procedure could be a useful adjunct in the field of major limb replantation.

  4. The phantom limb in dreams.

    PubMed

    Brugger, Peter

    2008-12-01

    Mulder and colleagues [Mulder, T., Hochstenbach, J., Dijkstra, P. U., Geertzen, J. H. B. (2008). Born to adapt, but not in your dreams. Consciousness and Cognition, 17, 1266-1271.] report that a majority of amputees continue to experience a normally-limbed body during their night dreams. They interprete this observation as a failure of the body schema to adapt to the new body shape. The present note does not question this interpretation, but points to the already existing literature on the phenomenology of the phantom limb in dreams. A summary of published investigations is complemented by a note on phantom phenomena in the dreams of paraplegic patients and persons born without a limb. Integration of the available data allows the recommendation for prospective studies to consider dream content in more detail. For instance, "adaptation" to the loss of a limb can also manifest itself by seeing oneself surrounded by amputees. Such projective types of anosognosia ("transitivism") in nocturnal dreams should also be experimentally induced in normally-limbed individuals, and some relevant techniques are mentioned.

  5. Possible living fossil in Bolivia: A new genus of flea beetles with modified hind legs (Coleoptera, Chrysomelidae, Galerucinae, Alticini)

    PubMed Central

    Konstantinov, Alexander S.

    2016-01-01

    Abstract A new genus (Chanealtica) with three new species (Chanealtica cuevas, Chanealtica ellimon, and Chanealtica maxi) from Bolivia is described and illustrated. It is compared with Aphthonoides Jacoby, 1885, Argopistes Motschulsky, 1860, Metroserrapha Bechyne, 1958, Psylliodes Berthold, 1827 and Psyllototus Nadein, 2010. Remarkably, based on the available characters, among all the flea beetles, Chanealtica is mostly similar to an extinct genus Psyllototus. A discussion of diversity and function of the hind leg in flea beetles is provided. PMID:27408546

  6. Cloning and characterization of a repetitive DNA detected by HindIII in the genome of Raja montagui (Batoidea, Chondrichthyes).

    PubMed

    Rocco, L; Stingo, V; Bellitti, M

    1996-10-17

    A repetitive HindIII fragment of DNA from Raja montagui (Rajiformes) was cloned and sequenced for the first time in cartilaginous fishes. This element, which comprises approximately 5% of the whole genome of the spotted ray, is absent in long tandem arrays, being typical of satellite DNA. It appeared constituted by 311 AT-rich bp (61%). The clone was hybridized to the genomic DNA of species with varying phyletic distances, revealing a high degree of conservation.

  7. Benefits for dominant red deer hinds under a competitive feeding system: food access behavior, diet and nutrient selection.

    PubMed

    Ceacero, Francisco; García, Andrés J; Landete-Castillejos, Tomás; Bartošová, Jitka; Bartoš, Ludek; Gallego, Laureano

    2012-01-01

    Social dominance is widely known to facilitate access to food resources in many animal species such as deer. However, research has paid little attention to dominance in ad libitum access to food because it was thought not to result in any benefit for dominant individuals. In this study we assessed if, even under ad libitum conditions, social rank may allow dominant hinds to consume the preferred components of food. Forty-four red deer hinds (Cervus elaphus) were allowed to consume ad libitum meal consisting of pellets of sunflower, lucerne and orange, and seeds of cereals, corn, cotton, and carob tree. The meal was placed only in one feeder, which reduced accessibility to a few individuals simultaneously. During seven days, feeding behavior (order of access, time to first feeding bout, total time spent feeding, and time per feeding bout) were assessed during the first hour. The relative abundance of each meal component was assessed at times 0, 1 and 5 h, as well as its nutritional composition. Social rank was positively related to the amount of time spent feeding during the 1(st) h (P = 0.048). Selection indices were positively correlated with energy (P = 0.018 during the 1(st) h and P = 0.047 from 1(st) to 5(th)) and fat (only during the 1(st) h; P = 0.036), but also negatively with certain minerals. Thus, dominant hinds could select high energy meal components for longer time under an ad libitum but restricted food access setting. Selection indices showed a higher selectivity when food availability was higher (1(st) hour respect to 1(st) to 5(th)). Finally, high and low ranking hinds had longer time per feeding bout than mid ones (P = 0.011), suggesting complex behavioral feeding tactics of low ranking social ungulates.

  8. Automated lower limb prosthesis design

    NASA Astrophysics Data System (ADS)

    Bhatia, Gulab H.; Commean, Paul K.; Smith, Kirk E.; Vannier, Michael W.

    1994-09-01

    The design of lower limb prostheses requires definitive geometric data to customize socket shape. Optical surface imaging and spiral x-ray computed tomography were applied to geometric analysis of limb residua in below knee (BK) amputees. Residua (limb remnants after amputation) of BK amputees were digitized and measured. Surface (optical) and volumetric (CT) data of the residuum were used to generate solid models and specify socket shape in (SDRC I-DEAS) CAD software. Volume measurements on the solid models were found to correspond within 2% of surface models and direct determinations made using Archimedean weighing. Anatomic 3D reconstruction of the residuum by optical surface and spiral x-ray computed tomography imaging are feasible modalities for prosthesis design.

  9. Apparatus for determining changes in limb volume

    NASA Technical Reports Server (NTRS)

    Bhagat, P. K.; Wu, V. C. (Inventor)

    1981-01-01

    Measuring apparatus for determining changes in the volume of limbs or other boty extremities by determining the cross-sectional area of such limbs many comprise a transmitter including first and second transducers for positioning on the surface of the limb at a predetermined distance there between, and a receiver including a receiver crystal for positioning on the surface of the limb. The distance between the receiver crystal and the first and second transducers are represented by respective first and second chords of the cross-section of the limb and the predetermined distance between the first and second transducers is represented by a third chord of the limb cross section.

  10. Factors Associated with Recently Transmitted Mycobacterium tuberculosis strain MS0006 in Hinds County, Mississippi

    PubMed Central

    Temple, Brian; Kwara, Awewura; Sunesara, Imran; Mena, Leandro; Dobbs, Thomas; Henderson, Harold; Holcomb, Mike; Webb, Risa

    2011-01-01

    Objective The objective of this study was to investigate risk factors associated with tuberculosis (TB) transmission that was caused by Mycobacterium tuberculosis strain MS0006 from 2004 to 2009 in Hinds County, Mississippi. Methods DNA fingerprinting using spoligotyping, mycobacterial interspersed repetitive unit, and IS6110-based restriction fragment length polymorphism of culture-confirmed cases of TB was performed. Clinical and demographic factors associated with strain MS0006 were analyzed by univariate and multivariate analysis. Results Of the 144 cases of TB diagnosed during the study period, 117 were culture positive with fingerprints available. There were 48 different strains, of which 6 clustered strains were distributed among 74 patients. The MS0006 strain accounted for 46.2% of all culture-confirmed cases. Risk factors for having the MS0006 strain in a univariate analysis included homelessness, HIV co-infection, sputum smear negativity, tuberculin skin test negativity, and noninjectable drug use. Multivariate analysis identified homelessness (odds ratio 7.88, 95% confidence interval 2.90-21.35) and African American race (odds ratio 5.80, 95% confidence interval 1.37-24.55) as independent predictors of having TB caused by the MS0006 strain of M tuberculosis. Conclusions Our findings suggest that a majority of recently transmitted TB in the studied county was caused by the MS0006 strain. African American race and homelessness were significant risk factors for inclusion in the cluster. Molecular epidemiology techniques continue to provide in-depth analysis of disease transmission and play a vital role in effective contact tracing and interruption of ongoing transmission. PMID:22089361

  11. Evolutionary Constraints in Hind Wing Shape in Chinese Dung Beetles (Coleoptera: Scarabaeinae)

    PubMed Central

    Bai, Ming; McCullough, Erin; Song, Ke-Qing; Liu, Wan-Gang; Yang, Xing-Ke

    2011-01-01

    paper sheds new light on the evolution of dung beetle hind wings. PMID:21738727

  12. Evolutionary constraints in hind wing shape in Chinese dung beetles (Coleoptera: Scarabaeinae).

    PubMed

    Bai, Ming; McCullough, Erin; Song, Ke-Qing; Liu, Wan-Gang; Yang, Xing-Ke

    2011-01-01

    paper sheds new light on the evolution of dung beetle hind wings.

  13. Asteroid Lightcurve Analysis at Riverland Dingo Observatory (RDO): 501 Urhixidur, 1897 Hind, 1928 Summa, 6261 Chione, and (68216) 2001 CV 26.

    NASA Astrophysics Data System (ADS)

    Hills, Kevin

    2013-01-01

    Lightcurves for five asteroids selected from the Collaborative Asteroid Lightcurve Link (CALL) were obtained at Riverland Dingo Observatory (RDO) from 2012 July-September: 501 Urhixidur, 1897 Hind, 1928 Summa, 6261 Chione, and (68216) 2001 CV26.

  14. Comparison of models to identify lame cows based on gait and lesion scores, and limb movement variables.

    PubMed

    Rajkondawar, P G; Liu, M; Dyer, R M; Neerchal, N K; Tasch, U; Lefcourt, A M; Erez, B; Varner, M A

    2006-11-01

    Bovine lameness results in pain and suffering in cattle and economic loss for producers. A system for automatically detecting lame cows was developed recently that measures vertical force components attributable to individual limbs. These measurements can be used to calculate a number of limb movement variables. The objective of this investigation was to explore whether gait scores, lesion scores, or combined gait and lesion scores were more effectively captured by a set of 5 limb movement variables. A set of 700 hind limb examinations was used to create gait-based, lesion-based, and combined (gait- and lesion-based) models. Logistic regression models were constructed using 1, 2, or 3 d of measurements. Resulting models were tested on cows not used in modeling. The accuracy of lesion-score models was superior to that of gait-score models; lesion-based models generated greater values of areas under the receiving operating characteristic curves (range 0.75 to 0.84) and lower mean-squared errors (0.13 to 0.16) compared with corresponding values for the gait-based models (0.63 to 0.73 and 0.26 to 0.31 for receiving operating characteristic and mean-squared errors, respectively). These results indicate that further model development and investigation could generate automated and objective methods of lameness detection in dairy cattle.

  15. Formation and ossification of limb elements in Trachemys scripta and a discussion of autopodial elements in turtles.

    PubMed

    Sheil, Christopher A; Portik, Daniel

    2008-06-01

    Though sequences of formation and ossification of bony elements have been described for many taxa, controversy surrounds the formation of limb elements in turtles. Three hypotheses for patterns of formation of autopodial elements have been proposed, differing primarily in the origin of Distal Carpal/Tarsal 3, the digital arch, and Centrale 4. Patterns of formation and ossification of limb elements are described for Trachemys scripta. These patterns are compared to similar data for representatives of four families of turtles (Cheloniidae, Chelydridae, Emydidae, and Trionychidae). Hypotheses of limb formation are compared in the context of new and published data. Three species (Trachemys scripta, Chrysemys picta, and Chelydra serpentina) suggest that Distal Carpal 3 forms by branching from the ulnare, whereas Distal Carpal 3 may branch from Distal Carpal 4 in Macrochelys temminckii and Chelonia mydas; data from Graptemys nigrinoda, Apalone spinifera, and Eretmochelys imbricata did not provide evidence for the origin of Distal Carpal 3. Centrale 4 was not observed to branch from the ulnare and apparently arises by de-novo condensation. Distal Carpal 4 did not branch from Centrale 4 in any species. Until the developmental origins of Distal Carpal 3 and Centrale 4 are understood, interspecific variation in the origin of these elements remains, and may explain some of the observed differences. Trends of ossification in the fore- and hind limb autopodium also are summarized. Homology of elements in pedal Digit V is discussed, and we suggest that the hooked proximal element of this digit be recognized as Distal Tarsal 5.

  16. Distorting limb design for dynamically similar locomotion.

    PubMed Central

    Bullimore, Sharon R.; Burn, Jeremy F.

    2004-01-01

    Terrestrial mammals of different sizes tend to move in a dynamically similar manner when travelling at speeds corresponding to equal values of the Froude number. This means that certain dimensionless locomotor parameters, including peak vertical ground reaction force relative to body weight, stride length relative to leg length and duty factor, are independent of animal size. The Froude number is consequently used to define equivalent speeds for mammals of different sizes. However, most musculoskeletal-tissue properties, including tendon elastic modulus, do not scale in a dynamically similar manner. Therefore, mammals could not be completely dynamically similar, even if perfectly geometrically similar. We argue that, for mammals to move in a dynamically similar manner, they must exhibit systematic 'distortions' of limb structure with size that compensate for the size independence of the tendon elastic modulus. An implication of this is that comparing mammals at equal Froude numbers cannot remove all size-dependent effects. We show that the previously published allometry of limb moment arms is sufficient to compensate for size-independent tendon properties. This suggests that it is an important factor in allowing mammals of different sizes to move in a dynamically similar manner. PMID:15058440

  17. Fingernails Yield Clues to Limb Regeneration

    MedlinePlus

    ... embryonic development, as well as limb regeneration in amphibians. They found that the Wnt pathway was active ... nerve cells was crucial for limb regeneration in amphibians, so they wanted to examine their role in ...

  18. Learning about Vertebrate Limb Development

    ERIC Educational Resources Information Center

    Liang, Jennifer O.; Noll, Matthew; Olsen, Shayna

    2014-01-01

    We have developed an upper-level undergraduate laboratory exercise that enables students to replicate a key experiment in developmental biology. In this exercise, students have the opportunity to observe live chick embryos and stain the apical ectodermal ridge, a key tissue required for development of the vertebrate limb. Impressively, every…

  19. Triple Compliant Limbs with Adaptive Body Structure

    DTIC Science & Technology

    2012-06-20

    legs, with the third limb being used as a tail to add stability and/or manipulation • One or Two Legged Hop : One or two limbs are used to store and...release energy to hop while the third limb is used for either stability or manipulation tasks • Brachiating: Limbs are used to grab objects overhead...2 LEG HOP (Energy Release) BRACHIATING DISMOUNTING (IMPACT ABSORBTION) CARTWHEELING 5 Gaits & Transitions Variety of gaits can be realized using

  20. The accessory limb model: an alternative experimental system of limb regeneration.

    PubMed

    Endo, Tetsuya; Gardiner, David M; Makanae, Aki; Satoh, Akira

    2015-01-01

    Accessory limb model (ALM) was developed as an experimental model and functional assay for limb regeneration. The ALM provides several ways to identify pathways and test for signaling molecules that regulate limb regeneration. Here, we summarize the history of the ALM and describe the specific details involved in inducing ectopic blastemas and limbs from a skin wound on the side of the arm.

  1. LIMB Demonstration Project Extension. Quarterly report no. 3, November, December 1987--January 1988

    SciTech Connect

    Not Available

    1988-03-15

    The basic goal of the Limestone Injection Multistage Burner (LIMB) demonstration is to extend LIMB technology development to a full-scale application on a representative wall-fired utility boiler. The successful retrofit of LIMB to an existing boiler is expected to demonstrate that (a) reductions of 50 percent or greater in SO{sub x} and NO{sub x} emissions can be achieved at a fraction of the cost of add-on FGD systems, (b) boiler reliability, operability, and steam production can be maintained at levels existing prior to LIMB retrofit, and (c) technical difficulties attributable to LIMB operation, such as additional slagging and fouling, changes in ash disposal requirements, and an increased particulate load, can be resolved in a cost-effective manner. The primary fuel to be used will be an Ohio bituminous coal having a nominal sulfur content of 3 percent or greater.

  2. LIMB Demonstration Project Extension. Quarterly report no. 5, May, June and July 1988

    SciTech Connect

    Not Available

    1988-09-15

    The basic goal of the Limestone Injection Multistage Burner (LIMB) demonstration is to extend LIMB technology development to a full-scale application on a representative wall-fired utility boiler. The successful retrofit of LIMB to an existing boiler is expected to demonstrate that (a) reductions of 50 percent or greater in SO and NO emissions can be achieved at a fraction of the cost of add-on FGD systems, (b) boiler reliability, operability, and steam production can be maintained at levels existing prior to LIMB retrofit, and (c) technical difficulties attributable to LIMB operation, such as additional slagging and fouling, changes in ash disposal requirements, and an increased particulate load, can be resolved in a cost-effective manner. The primary fuel to be used will be an Ohio bituminous coal having a nominal sulfur content of 3 percent or greater.

  3. Noninvasive Multimodal Imaging to Predict Recovery of Locomotion after Extended Limb Ischemia.

    PubMed

    Radowsky, Jason S; Caruso, Joseph D; Luthra, Rajiv; Bradley, Matthew J; Elster, Eric A; Forsberg, Jonathan A; Crane, Nicole J

    2015-01-01

    Acute limb ischemia is a common cause of morbidity and mortality following trauma both in civilian centers and in combat related injuries. Rapid determination of tissue viability and surgical restoration of blood flow are desirable, but not always possible. We sought to characterize the response to increasing periods of hind limb ischemia in a porcine model such that we could define a period of critical ischemia (the point after which irreversible neuromuscular injury occurs), evaluate non-invasive methods for characterizing that ischemia, and establish a model by which we could predict whether or not the animal's locomotion would return to baselines levels post-operatively. Ischemia was induced by either application of a pneumatic tourniquet or vessel occlusion (performed by clamping the proximal iliac artery and vein at the level of the inguinal ligament). The limb was monitored for the duration of the procedure with both 3-charge coupled device (3CCD) and infrared (IR) imaging for tissue oxygenation and perfusion, respectively. The experimental arms of this model are effective at inducing histologically evident muscle injury with some evidence of expected secondary organ damage, particularly in animals with longer ischemia times. Noninvasive imaging data shows excellent correlation with post-operative functional outcomes, validating its use as a non-invasive means of viability assessment, and directly monitors post-occlusive reactive hyperemia. A classification model, based on partial-least squares discriminant analysis (PLSDA) of imaging variables only, successfully classified animals as "returned to normal locomotion" or "did not return to normal locomotion" with 87.5% sensitivity and 66.7% specificity after cross-validation. PLSDA models generated from non-imaging data were not as accurate (AUC of 0.53) compared the PLSDA model generated from only imaging data (AUC of 0.76). With some modification, this limb ischemia model could also serve as a means on which

  4. Gait changes in a line of mice artificially selected for longer limbs

    PubMed Central

    Sparrow, Leah M.; Pellatt, Emily; Yu, Sabrina S.; Raichlen, David A.; Pontzer, Herman

    2017-01-01

    In legged terrestrial locomotion, the duration of stance phase, i.e., when limbs are in contact with the substrate, is positively correlated with limb length, and negatively correlated with the metabolic cost of transport. These relationships are well documented at the interspecific level, across a broad range of body sizes and travel speeds. However, such relationships are harder to evaluate within species (i.e., where natural selection operates), largely for practical reasons, including low population variance in limb length, and the presence of confounding factors such as body mass, or training. Here, we compared spatiotemporal kinematics of gait in Longshanks, a long-legged mouse line created through artificial selection, and in random-bred, mass-matched Control mice raised under identical conditions. We used a gait treadmill to test the hypothesis that Longshanks have longer stance phases and stride lengths, and decreased stride frequencies in both fore- and hind limbs, compared with Controls. Our results indicate that gait differs significantly between the two groups. Specifically, and as hypothesized, stance duration and stride length are 8–10% greater in Longshanks, while stride frequency is 8% lower than in Controls. However, there was no difference in the touch-down timing and sequence of the paws between the two lines. Taken together, these data suggest that, for a given speed, Longshanks mice take significantly fewer, longer steps to cover the same distance or running time compared to Controls, with important implications for other measures of variation among individuals in whole-organism performance, such as the metabolic cost of transport. PMID:28243533

  5. Construction and validation of a microprocessor controlled extracorporal circuit in rats for the optimization of isolated limb perfusion.

    PubMed

    Gürtler, Ulrich; Fuchs, Peter; Stangelmayer, Achim; Bernhardt, Günther; Buschauer, Armin; Spruss, Thilo

    2004-12-01

    Although a few experimental approaches to isolated limb perfusion (ILP) are described in the literature, none of these animal models mimics the clinical perfusion techniques adequately to improve the technique of ILP on the basis of valid preclinical data. Therefore, we developed an ILP setup in rats allowing online monitoring of essential perfusion parameters such as temperature (in perfusate, various tissues, and rectum), pH (perfusate), perfusion pressure, and O(2) concentration (in perfusate, tissue), by a tailor-made data acquisition system. This setup permits close supervision of vital parameters during ILP. Various interdependencies, concerning the flow rate and the pressure of perfusate as well as tissue oxygenation were registered. For the measurement of pO(2) values in the perfusate and in different regions of the perfused hind limb, a novel type of microoptode based on quenching of a fluorescent dye was devised. Stable normothermic (37 degrees C) perfusion conditions were maintained at a constant perfusion pressure in the range of 40-60 mm Hg by administration of the spasmo lytic moxaverine (0.5 mg/mL of perfusate as initial dose) at a perfusate flow rate of 0.5 mL/min for 60 min. At the end of an ILP, there were no signs of tissue damage, neither concerning laboratory data (K(+), myoglobin, creatine kinase, lactic dehydrogenase) nor histopathological criteria. The reported ILP model is not only well suited to investigate the effects of hyperthermia but also to assess the efficacy of new antineoplastic approaches, when nude rats, bearing human tumours in the hind limbs, are used.

  6. Limb remote-preconditioning protects against focal ischemia in rats and contradicts the dogma of therapeutic time windows for preconditioning.

    PubMed

    Ren, C; Gao, X; Steinberg, G K; Zhao, H

    2008-02-19

    Remote ischemic preconditioning is an emerging concept for stroke treatment, but its protection against focal stroke has not been established. We tested whether remote preconditioning, performed in the ipsilateral hind limb, protects against focal stroke and explored its protective parameters. Stroke was generated by a permanent occlusion of the left distal middle cerebral artery (MCA) combined with a 30 min occlusion of the bilateral common carotid arteries (CCA) in male rats. Limb preconditioning was generated by 5 or 15 min occlusion followed with the same period of reperfusion of the left hind femoral artery, and repeated for two or three cycles. Infarct was measured 2 days later. The results showed that rapid preconditioning with three cycles of 15 min performed immediately before stroke reduced infarct size from 47.7+/-7.6% of control ischemia to 9.8+/-8.6%; at two cycles of 15 min, infarct was reduced to 24.7+/-7.3%; at two cycles of 5 min, infarct was not reduced. Delayed preconditioning with three cycles of 15 min conducted 2 days before stroke also reduced infarct to 23.0+/-10.9%, but with two cycles of 15 min it offered no protection. The protective effects at these two therapeutic time windows of remote preconditioning are consistent with those of conventional preconditioning, in which the preconditioning ischemia is induced in the brain itself. Unexpectedly, intermediate preconditioning with three cycles of 15 min performed 12 h before stroke also reduced infarct to 24.7+/-4.7%, which contradicts the current dogma for therapeutic time windows for the conventional preconditioning that has no protection at this time point. In conclusion, remote preconditioning performed in one limb protected against ischemic damage after focal cerebral ischemia.

  7. Technical note: Effects of attachment of hind teats before cleaning and attachment of front teats on milking characteristics in automatic milking systems.

    PubMed

    Besier, J; Schüpbach-Regula, G; Wellnitz, O; Bruckmaier, R M

    2017-04-01

    Milking characteristics differ between the 4 quarters of a dairy cow udder. In particular, milking time is mostly prolonged in hind quarters compared with front quarters because of the usually higher amount of stored milk. The standard milking routine (STDMR) in both conventional and automatic milking systems (AMS) consists of teat preparation of all 4 quarters, followed by attachment of the 4 teat cups, regardless of the distribution of milk between quarters. In the current study, an alternative teat preparation and milking routine (ALTMR) in AMS was tested, which consisted of cleaning and starting the milking of hind teats before cleaning and attachment of front teats. The hypothesis was based on the fact that hind quarters have usually a longer milking time than front quarters. Starting the milking of hind quarters while the front teats are being cleaned may reduce the difference in the end of milking between front and hind quarters and thus reduce total milking time. Both routines were tested on 5 Swedish dairy farms equipped with AMS in a 4-wk experiment in which treatments were alternated weekly. Total milk yield did not differ between treatments. Machine-on time (MOT) was longer in ALTMR than in STDMR because the difference in milking time between hind and front quarters was less than the time needed to prepare the front teats. However, the longer MOT in ALTMR was compensated by a shorter total preparation time, including the attachment of the first teat cup, as only the hind teats (instead of all 4 teats) were cleaned before milking was started. This resulted in a similar total milking time from start of cleaning of the first quarter until the end of milking of the last quarter in both treatments. Because of the prolonged MOT, average milk flow rate was lower in ALTMR than STDMR. Peak flow rate was higher in ALTMR than STDMR, but only in teat cups 1 (first attached, hind quarter) and 3 (third attached, front quarter), whereas main milk flow was higher in

  8. The migration and loss of human primordial germ stem cells from the hind gut epithelium towards the gonadal ridge.

    PubMed

    Mamsen, Linn Salto; Brøchner, Christian Beltoft; Byskov, Anne Grete; Møllgard, Kjeld

    2012-01-01

    Human primordial germ cells (PGCs) can be recognized in the yolk sac wall, from 3-4 weeks post conception (wpc), in the hind gut epithelium from week 4 and in the gonadal area from early week 5. The objective of this study was to map the migration route of PGCs and elucidate the role of the nervous system in this process. Sixteen human specimens, 5-14 wpc obtained from legal abortions were included. On serial paraffin sections, PGCs were detected immunohistochemically by expression of OCT4 and c-Kit, nerve fibers by β-III-tubulin and stem cell factor (SCF) as a possible chemoattractive cue for PGC migration. PGCs were present in the hind gut epithelium, in the mesenchyme of the dorsal mesentery and in the developing gonadal ridge of 4-6 wpc embryos, prior to connections between the enteric and the sympathetic nervous system. From 6 wpc onwards, the PGCs travelled along the developing nerve fibers from the wall of the hind gut via the dorsal mesentery to the midline of the dorsal wall and laterally into the gonads. Numerous PGCs were still present in the nervous system by 14 wpc. PGCs in 4-5 wpc embryos are suggested to leave the gut epithelium by EMT-like transition. SCF may facilitate further migration, but after establishment of connections between the enteric and sympathetic nervous systems. PGCs follow sympathetic nerve fibers towards the gonads. PGCs failing to exit the nerve branches at the gonadal site, may continue along the sympathetic trunk ending up in other organs where they may form germ cell tumors if not eliminated by apoptosis.

  9. Continuum limbed robots for locomotion

    NASA Astrophysics Data System (ADS)

    Mutlu, Alper

    This thesis focuses on continuum robots based on pneumatic muscle technology. We introduce a novel approach to use these muscles as limbs of lightweight legged robots. The flexibility of the continuum legs of these robots offers the potential to perform some duties that are not possible with classical rigid-link robots. Potential applications are as space robots in low gravity, and as cave explorer robots. The thesis covers the fabrication process of continuum pneumatic muscles and limbs. It also provides some new experimental data on this technology. Afterwards, the designs of two different novel continuum robots - one tripod, one quadruped - are introduced. Experimental data from tests using the robots is provided. The experimental results are the first published example of locomotion with tripod and quadruped continuum legged robots. Finally, discussion of the results and how far this technology can go forward is presented.

  10. Investigation of Mesospheric Metal Emission Signals from SCIAMACHY Limb Measurements

    DTIC Science & Technology

    2013-10-31

    identified (see, e.g. [3]). The first results from the comet trails of comets that pass closely by the earth on time scales on the order of 100 years. The...entering the earth atmoshere comes from the Jupiter Family Comets . The total daily mass input of meteoric material is still uncertain and estimates range...the daily input of meteoric material to the earth atmosphere. The knowledge won from the MLT dataset can be used to reanalyze the nominal limb and

  11. Allometric scaling for chemical restraint in greater Rheas (Rhea americana) with Tiletamine and Zolazepam

    PubMed Central

    2014-01-01

    Background Chemical restraint is of great importance in the clinical practice of wildlife animals. In such, interspecific allometric scaling proposes pharmacological doses to a wide range of species, based on previously known doses for domestic animals and the target animal’s body mass. The objective was to compare chemical restraint responses in the greater rhea (Rhea americana) with conventional doses of tiletamine/zolazepam, found in the literature for the species, and with doses calculated through interspecific allometric scaling extrapolation. From the Federal University of Piauí, six adult greater rheas (Rhea americana), three males and three females, were randomly selected to be subjects in this research. All six animals were submitted to two chemical restraint protocols with tiletamine and zolazepam, per intramuscular injection in the hind limb. The first protocol was composed of doses found on the literature for the species, while the second protocol used doses calculated by interspecific allometric scaling, with the domestic dog as model animal. Heart and respiratory rates, body temperature, eyelid reflex, digital pinch and metatarsal reflex were registered along with latency and ambulation times. Results The use of interspecific allometric scaling for chemical restraint with the combination tiletamine and zolazepam showed satisfying results, with great similarity to results obtained with conventional doses in Greater rheas. Conclusions Literature on chemical restraint and use of tiletamine and zolazepam in rheas is scarce. Chemical restraint is of extreme importance on these animals, due to their aggressive nature and low level of domesticity. This research may further establish the interspecific allometric scaling method as a viable tool for the veterinary physician in formulating anesthetic and chemical restraint protocols for wildlife animals. PMID:24625103

  12. Dose Response in Rodents and Nonhuman Primates After Hydrodynamic Limb Vein Delivery of Naked Plasmid DNA

    PubMed Central

    Hegge, Julia O.; Zhang, Guofeng; Sebestyén, Magdolna G.; Noble, Mark; Griffin, Jacob B.; Pfannes, Loretta V.; Herweijer, Hans; Hagstrom, James E.; Braun, Serge; Huss, Thierry; Wolff, Jon A.

    2011-01-01

    Abstract The efficacy of gene therapy mediated by plasmid DNA (pDNA) depends on the selection of suitable vectors and doses. Using hydrodynamic limb vein (HLV) injection to deliver naked pDNA to skeletal muscles of the limbs, we evaluated key parameters that affect expression in muscle from genes encoded in pDNA. Short-term and long-term promoter comparisons demonstrated that kinetics of expression differed between cytomegalovirus (CMV), muscle creatine kinase, and desmin promoters, but all gave stable expression from 2 to 49 weeks after delivery to mouse muscle. Expression from the CMV promoter was highest. For mice, rats, and rhesus monkeys, the linear range for pDNA dose response could be defined by the mass of pDNA relative to the mass of target muscle. Correlation between pDNA dose and expression was linear between a threshold dose of 75 μg/g and maximal expression at approximately 400 μg/g. One HLV injection into rats of a dose of CMV-LacZ yielding maximal expression resulted in an average transfection of 28% of all hind leg muscle and 40% of the gastrocnemius and soleus. Despite an immune reaction to the reporter gene in monkeys, a single injection transfected an average of 10% of all myofibers in the targeted muscle of the arms and legs and an average of 15% of myofibers in the gastrocnemius and soleus. PMID:21338336

  13. Exposure of the cat limb to @5C for 5 hours increases capillary permeability

    SciTech Connect

    Zhang, J.X.; Porter, L.P.; Wolf, M.B. )

    1991-03-11

    The authors previous study showed that 1 hr exposure to {approximately}5C temperatures did not decrease the solvent drag reflection coefficient ({sigma}{sub f}) for total plasma proteins in the isolated, constant-flow perfused cat hind limb. The present study determined if 5 hrs of cold exposure could increase permeability (decrease {sigma}{sub f}). {sigma}{sub f} was measured with their IMB method after lowering limb temperature to 3-6C by cooling the perfusing blood and the ambient air. To prevent edema at this low temperature, venous pressure had to be lowered to just above venous collapse and flow to {lt}2 ml/min/100g. 1 hr exposure to {approximately}5C did not reduce {sigma}{sub f} from the 37C control, but 5 hrs of exposure at {approximately}5C significantly reduced {sigma}{sub f} from 0.87 to 0.69. Hence, 5 hrs of perfusion at these low temperatures can cause a non-freezing cold injury with an increase in capillary permeability and edema formation. Also, the edema is enhanced by an increase in capillary hydrostatic pressure secondary to a venous resistance increase.

  14. Thermographic evaluation of hind paw skin temperature and functional recovery of locomotion after sciatic nerve crush in rats

    PubMed Central

    Z. Sacharuk, Viviane; A. Lovatel, Gisele; Ilha, Jocemar; Marcuzzo, Simone; Severo do Pinho, Alexandre; L. Xavier, Léder; A. Zaro, Milton; Achaval, Matilde

    2011-01-01

    INTRODUCTION: Peripheral nerves are often damaged by direct mechanical injury, diseases, and tumors. The peripheral nerve injuries that result from these conditions can lead to a partial or complete loss of motor, sensory, and autonomic functions, which in turn are related to changes in skin temperature, in the involved segments of the body. The aim of this study was to evaluate the changes in hind paw skin temperature after sciatic nerve crush in rats in an attempt to determine whether changes in skin temperature correlate with the functional recovery of locomotion. METHODS: Wistar rats were divided into three groups: control (n = 7), sham (n = 25), and crush (n = 25). All groups were subjected to thermographic, functional, and histological assessments. RESULTS: ΔT in the crush group was different from the control and sham groups at the 1st, 3rd and 7rd postoperative days (p<0.05). The functional recovery from the crush group returned to normal values between the 3rd and 4th week post-injury, and morphological analysis of the nerve revealed incomplete regeneration at the 4th week after injury. DISCUSSION: This study is the first demonstration that sciatic nerve crush in rats induces an increase in hind paw skin temperature and that skin temperature changes do not correlate closely with functional recovery PMID:21876984

  15. Vertical Distribution of Aersols and Water Vapor Using CRISM Limb Observations

    NASA Technical Reports Server (NTRS)

    Smith, Michael D.; Wolff, Michael J.; Clancy, R. Todd

    2011-01-01

    Near-infrared spectra taken in a limb-viewing geometry by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) on-board the Mars Reconnaissance Orbiter (MRO) provide a useful tool for probing atmospheric structure. Specifically, the observed radiance as a function of wavelength and height above the limb allows the vertical distribution of both dust and ice aerosols to be retrieved. These data serve as an important supplement to the aerosol profiling provided by the MRO/MCS instrument allowing independent validation and giving additional information on particle physical and scattering properties through multi-wavelength studies. A total of at least ten CRISM limb observations have been taken so far covering a full Martian year. Each set of limb observations nominally contains about four dozen scans across the limb giving pole-to-pole coverage for two orbits at roughly 100 and 290 W longitude over the Tharsis and Syrtis/Hellas regions, respectively. At each longitude, limb scans are spaced roughly 10 degrees apart in latitude, with a vertical spatial resolution on the limb of roughly 800 m. Radiative transfer modeling is used to model the observations. We compute synthetic CRISM limb spectra using a discrete-ordinates radiative transfer code that accounts for multiple scattering from aerosols and accounts for spherical geometry of the limb observations by integrating the source functions along curved paths in that coordinate system. Retrieved are 14-point vertical profiles for dust and water ice aerosols with resolution of 0.4 scale heights between one and six scale heights above the surface. After the aerosol retrieval is completed, the abundances of C02 (or surface pressure) and H20 gas are retrieved by matching the depth of absorption bands at 2000 nm for carbon dioxide and at 2600 run for water vapor. In addition to the column abundance of water vapor, limited information on its vertical structure can also be retrieved depending on the signal

  16. Prevalence and characteristics of phantom limb pain and residual limb pain in the long term after upper limb amputation.

    PubMed

    Desmond, Deirdre M; Maclachlan, Malcolm

    2010-09-01

    This study aims to describe the prevalence and characteristics of phantom limb pain and residual limb pain after upper limb amputation. One-hundred and forty-one participants (139 males; mean age 74.8 years; mean time since amputation 50.1 years) completed a self-report questionnaire assessing residual and phantom limb pain experience. Prevalence of phantom limb pain during the week preceding assessment was 42.6% (60 of 141). Prevalence of residual limb pain was 43.3% (61 of 141). More than one third of these had some pain constantly or most days. Phantom limb pain was commonly described as 'discomforting' (31 of 60) and associated with 'a little bit' of lifestyle interference (23 of 60). Residual limb pain was most often described as 'discomforting' (27 of 61) or 'distressing' (19 of 61) and was typically associated with low to moderate levels of lifestyle interference. Assessment of multiple dimensions of postamputation pain in the long term after upper limb amputation is warranted.

  17. The molecular regulation of vertebrate limb patterning.

    PubMed

    Butterfield, Natalie C; McGlinn, Edwina; Wicking, Carol

    2010-01-01

    The limb has long been considered a paradigm for organogenesis because of its simplicity and ease of manipulation. However, it has become increasingly clear that the processes required to produce a perfectly formed limb involve complex molecular interactions across all three axes of limb development. Old models have evolved with acquisition of molecular knowledge, and in more recent times mathematical modeling approaches have been invoked to explain the precise spatio-temporal regulation of gene networks that coordinate limb patterning and outgrowth. This review focuses on recent advances in our understanding of vertebrate limb development, highlighting the signaling interactions required to lay down the pattern on which the processes of differentiation will act to ultimately produce the final limb.

  18. Ultrasound imaging in lower limb prosthetics.

    PubMed

    Douglas, Tania; Solomonidis, Stephan; Sandham, William; Spence, William

    2002-03-01

    The biomechanical interaction between the residual limb and the prosthetic socket determines the quality of fit of the socket in lower limb prosthetics. An understanding of this interaction and the development of quantitative measures to predict the quality of fit of the socket are important for optimal socket design. Finite-element modeling is used widely for biomechanical modeling of the limb/socket interaction and requires information on the internal and external geometry of the residual limb. Volumetric imaging methods such as X-ray computed tomography, magnetic resonance imaging, and ultrasound have been used to obtain residual limb shape information. Of these modalities, ultrasound has been introduced most recently and its development for visualization in prosthetics is the least mature. This paper reviews ultrasound image acquisition and processing methods as they have been applied in lower limb prosthetics.

  19. Mangling upper limb injuries in industry.

    PubMed

    Ring, D; Jupiter, J B

    1999-01-01

    The salvage of upper limbs mangled by industrial machinery became possible with the development of predictable techniques of vascular and microvascular anastamosis. Unfortunately, many of these salvaged limbs are associated with fair and poor functional outcomes. The quality of the skeletal fixation can have a substantial effect on the functional outcome and should be a major focus of the limb repair process. Internal plate fixation facilitates wound care and limb mobilization without tethering muscle-tendon units and is safe in the majority of severe upper limb injuries provided that all devitalized tissue is debrided and, if necessary, reconstructed using microvascular tissue transfers. Injury patterns, especially those which involve associated injury of the elbow or forearm ligaments, must be identified and treated appropriately. Internal fixation should restore anatomical alignment and provide sufficient stability to allow immediate active mobilization of the limb without contributing to devascularization of the soft tissues or skeleton.

  20. Validation of NIRS in measuring tissue hemoglobin concentration and oxygen saturation on ex vivo and isolated limb models

    NASA Astrophysics Data System (ADS)

    Xu, Xiaorong; Zhu, Wen; Padival, Vikram; Xia, Mengna; Cheng, Xuefeng; Bush, Robin; Christenson, Linda; Chan, Tim; Doherty, Tim; Iatridis, Angelo

    2003-07-01

    Photonify"s tissue spectrometer uses Near-Infrared Spectroscopy for real-time, noninvasive measurement of hemoglobin concentration and oxygen saturation [SO2] of biological tissues. The technology was validated by a series of ex vivo and animal studies. In the ex vivo experiment, a close loop blood circulation system was built, precisely controlling the oxygen saturation and the hemoglobin concentration of a liquid phantom. Photonify"s tissue spectrometer was placed on the surface of the liquid phantom for real time measurement and compared with a gas analyzer, considered the gold standard to measure oxygen saturation and hemoglobin concentration. In the animal experiment, the right hind limb of each dog accepted onto the study was surgically removed. The limb was kept viable by connecting the femoral vein and artery to a blood-primed extracorporeal circuit. Different concentrations of hemoglobin were obtained by adding designated amount of saline solution into the perfusion circuit. Photonify"s tissue spectrometers measured oxygen saturation and hemoglobin concentration at various locations on the limb and compared with gas analyzer results. The test results demonstrated that Photonify"s tissue spectrometers were able to detect the relative changes in tissue oxygen saturation and hemoglobin concentration with a high linear correlation compared to the gas analyzer

  1. New concepts in lower limb orthotics.

    PubMed

    Loke, M

    2000-08-01

    Lower limb orthotics is in the process of a default transformation because of its association with lower limb prosthetics, a mechanical discipline that has translated component and material innovations into balance and velocity function gains to achieve a level of ambulation not possible a generation ago. This article discusses the fundamental mechanical similarities and differences of lower limb orthotics to prosthetics and their application to orthoses designed to improve the gait outcome of patients requiring orthotic intervention.

  2. Treatment of acute lower limb ischaemia.

    PubMed

    Lukasiewicz, Aleksander

    2016-01-01

    Acute lower limb ischaemia poses a major threat to limb survival. For many years surgical thromboembolectomy was the mainstay of treatment. Recent years have brought an endovascular revolution in the management of acute lower limb ischaemia. A wide range of endovascular procedures can nowadays be employed, providing results at least as good as the traditional surgical approach. This paper is an overview of currently utilised endovascular options as well as recent modifications of standard surgical techniques.

  3. Critical Limb Ischemia: Reporting Outcomes and Quality

    PubMed Central

    2012-01-01

    The impetus to pursue quality in limb salvage is high in the current economic environment. This has been spurred on by the diffusion of multiple technologies, the lack of well-defined cost-effectiveness benchmarks, and the paucity of process and structure benchmarks. Furthermore, no national database exists to capture current activity and trends, and lead structure and process changes that could analyze outcomes and improve standards in peripheral interventions for limb salvage. This manuscript examines the challenges in measuring outcomes and quality in limb salvage and explores the components necessary for ensuring quality in limb salvage interventions. PMID:23342183

  4. Endovascular Techniques in Limb Salvage: Stents

    PubMed Central

    El-Sayed, Hosam F.

    2013-01-01

    In patients with critical limb ischemia, the first-line approach for limb salvage has shifted over the past decade from bypass surgery to endovascular intervention. Stenting for the treatment of lower-extremity arterial occlusive disease is an important tool and continues to evolve, with new stent designs and technologies that have been developed to provide superior patency rates and limb salvage. In this article, we discuss the role of peripheral stenting in the treatment of patients with critical limb ischemia, including a review of the relevant current literature and the future directions of such interventions. PMID:23805339

  5. Development of body condition in hinds of Iberian red deer during gestation and its effects on calf birth weight and milk production.

    PubMed

    Carrión, Déborah; García, Andrés José; Gaspar-López, Enrique; Landete-Castillejos, Tomás; Gallego, Laureano

    2008-01-01

    Reproductive effort affects body reserves and subsequent ability to reproduce. In fact, the energy costs of gestation and lactation in hinds of red deer have a marked effect on maternal condition. The objectives of this study were to examine the development of hind monthly body condition during gestation in relation to reproductive rest, age and age class, just as its effects on total milk yield and calf birth weight. Eighty hinds of Iberian red deer were used as subjects during 2 years of study. They had ad libitum access to food and water. Animals were weighed weekly, and body condition was individually assessed. Milking was carried out under anesthesia with a milking machine followed by hand milking to collect the remaining milk. Age and reproductive rest influenced body condition, improving with age (coefficient: 0.10+/-0.01; P<0.001) and reproductive rest (mean+/-SEM, 3.75+/-0.05 vs. 3.25+/-0.02, with and without rest respectively; P<0.001). Hind age correlated positively with her body condition (R=0.62, P<0.001), however, when age class was included in the model, age was not significant. The greater the age class (up to age class 4) the greater the body condition; however, hinds of age class 5 had a lower body condition, but no significant differences were observed. Development of the body condition during gestation was different to age class 1 with respect to the others, just as between hinds that rested the preceding year and those that did not.

  6. Limb Bone Structural Proportions and Locomotor Behavior in A.L. 288-1 ("Lucy")

    PubMed Central

    Ruff, Christopher B.; Burgess, M. Loring; Ketcham, Richard A.; Kappelman, John

    2016-01-01

    While there is broad agreement that early hominins practiced some form of terrestrial bipedality, there is also evidence that arboreal behavior remained a part of the locomotor repertoire in some taxa, and that bipedal locomotion may not have been identical to that of modern humans. It has been difficult to evaluate such evidence, however, because of the possibility that early hominins retained primitive traits (such as relatively long upper limbs) of little contemporaneous adaptive significance. Here we examine bone structural properties of the femur and humerus in the Australopithecus afarensis A.L. 288–1 ("Lucy", 3.2 Myr) that are known to be developmentally plastic, and compare them with other early hominins, modern humans, and modern chimpanzees. Cross-sectional images were obtained from micro-CT scans of the original specimens and used to derive section properties of the diaphyses, as well as superior and inferior cortical thicknesses of the femoral neck. A.L. 288–1 shows femoral/humeral diaphyseal strength proportions that are intermediate between those of modern humans and chimpanzees, indicating more mechanical loading of the forelimb than in modern humans, and by implication, a significant arboreal locomotor component. Several features of the proximal femur in A.L. 288–1 and other australopiths, including relative femoral head size, distribution of cortical bone in the femoral neck, and cross-sectional shape of the proximal shaft, support the inference of a bipedal gait pattern that differed slightly from that of modern humans, involving more lateral deviation of the body center of mass over the support limb, which would have entailed increased cost of terrestrial locomotion. There is also evidence consistent with increased muscular strength among australopiths in both the forelimb and hind limb, possibly reflecting metabolic trade-offs between muscle and brain development during hominin evolution. Together these findings imply significant

  7. Balneotherapy in Treatment of Spastic Upper Limb after Stroke

    PubMed Central

    Erceg-Rukavina, Tatjana; Stefanovski, Mihajlo

    2015-01-01

    Introduction: After stroke, spasticity is often the main problem that prevents functional recovery. Pain occurs in up to 70% of patients during the first year post-stroke. Materials and methods: A total of 70 patients (30 female and 45 male) mean age (65.67) participated in prospective, controlled study. Inclusion criteria: ischaemic stroke, developed spasticity of upper limb, post-stroke interval <6 months. Exclusion criteria: contraindications for balneotherapy and inability to follow commands. Experimental group (Ex) (n=35) was treated with sulphurous baths (31°-33°C) and controlled group (Co) with taped water baths, during 21 days. All patients were additionally treated with kinesitherapy and cryotherapy. The outcome was evaluated using Modified Ashworth scale for spasticity and VAS scale for pain. The significance value was sat at p<0.05. Goal: To find out the effects of balneotherapy with sulphurous bath on spasticity and pain in affected upper limb. Results: Reduction in tone of affected upper limb muscles was significant in Ex group (p<0.05). Pain decreased significantly in Ex-group (p<0.01). Conclusion: Our results show that balneotherapy with sulphurous water reduces spasticity and pain significantly and can help in treatment of post-stroke patients. PMID:25870474

  8. Extracellular Control of Limb Regeneration

    NASA Astrophysics Data System (ADS)

    Calve, S.; Simon, H.-G.

    Adult newts possess the ability to completely regenerate organs and appendages. Immediately after limb loss, the extracellular matrix (ECM) undergoes dramatic changes that may provide mechanical and biochemical cues to guide the formation of the blastema, which is comprised of uncommitted stem-like cells that proliferate to replace the lost structure. Skeletal muscle is a known reservoir for blastema cells but the mechanism by which it contributes progenitor cells is still unclear. To create physiologically relevant culture conditions for the testing of primary newt muscle cells in vitro, the spatio-temporal distribution of ECM components and the mechanical properties of newt muscle were analyzed. Tenascin-C and hyaluronic acid (HA) were found to be dramatically upregulated in the amputated limb and were co-expressed around regenerating skeletal muscle. The transverse stiffness of muscle measured in situ was used as a guide to generate silicone-based substrates of physiological stiffness. Culturing newt muscle cells under different conditions revealed that the cells are sensitive to both matrix coating and substrate stiffness: Myoblasts on HA-coated soft substrates display a rounded morphology and become more elongated as the stiffness of the substrate increases. Coating of soft substrates with matrigel or fibronectin enhanced cell spreading and eventual cell fusion.

  9. [Critical limb ischemia--update].

    PubMed

    Melamed, Eitan; Kotyba, Baydousi; Galili, Offer; Karmeli, Ron

    2010-12-01

    Critical limb ischemia (CLI) is the most severe manifestation of peripheral artery occlusive disease. Without timely diagnosis and revascularization, patients with CLI are at risk of devastating complications including loss of limb and life. Therapeutic goals in treating patients with CLI include reducing cardiovascular risk factors, relieving ischemic pain, heating ulcers, preventing major amputation, improving quality of life and increasing survival. These aims may be achieved through medical therapy, revascularization or amputation. The past decade has seen substantial growth in endovascular therapies and options now exist for treating long segment occlusive disease, but surgical bypass may still yield more durable results. Patients who are younger, more active, and at low risk for surgery, may have better outcomes undergoing an operation. This is also indicated for endovascular failures, which may include technical failures or late occlusions after stents or other procedures. In contrast, frail patients with a limited life expectancy may experience better outcomes with endovascular therapy. For patients who are non-ambulatory, demented, or unfit to undergo revascularization, an amputation should be considered.

  10. Novel Dynamics Observed in a Spiking Neural Network Model of the NTS in the Rat Hind-brain

    NASA Astrophysics Data System (ADS)

    Zhou, Jingyi; Schaffer, J. David; Dilorenzo, Patricia; Laramee, Craig

    2012-02-01

    The Nucleus of the Solitary Tract (NTS) is a hind-brain structure in the rat that is the first way-station in taste processing. Its structure and function are poorly understood. Recently our group produced a model, implemented as a spiking neural network (SNN), that successfully replicated experimental data. The model's topology was manually devised and the parameters were set by a genetic algorithm. In order to better understand its information processing capabilities, we probed the model with a variety of input spike patterns and observed a striking winner-take-all decision-making dynamic. We show how the topology and tuned parameters enable this decision to depend on precise spike timing events. It is curious that the experimental data upon which the model was originally evolved did not include winner-take-all examples; this was an emergent capability. It remains for additional experiments on rats to confirm or reject this model prediction.

  11. Effect of external lymph drainage and of coumarin treatment on thermal injury in the rat hind leg

    PubMed Central

    Földi-Börcsök, Ethel

    1972-01-01

    1. External lymph drainage brings about a significant protective effect in thermal oedema of the rat hind leg. It is suggested that external lymph drainage prevents vasoactive substances drained from the site of injury from passing into the blood stream, which would further increase permeability of the injured blood capillaries. 2. Coumarin (5,6-benzo-alpha-pyron) brings about a significant protective effect against the same injury in sham-operated rats. 3. The strongest protective effect may be attained by combining external lymph drainage with the administration of coumarin. 4. The additional therapeutic effect brought about by coumarin treatment in rats with external lymph drainage is not mediated by an increased flow. The possible mechanisms are discussed. PMID:4651772

  12. Radioprotection by WR-151327 against the late normal tissue damage in mouse hind legs from gamma ray radiation

    SciTech Connect

    Matsushita, Satoru; Ando, Koichi; Koike, Sachiko

    1994-11-15

    To evaluate the protective effect of WR-151327 on late radiation-induced damaged to normal tissues in mice, the right hind legs of mice with or without WR-151327 administration (400 mg/kg) were irradiated with {sup 137}Cs gamma rays. Leg contracture and skin shrinkage assays were performed at 380 days after irradiation. The mice were killed on day 400 postirradiation and histological sections of the legs were made. The thickness of the dermis, epidermis, and skin (dermis plus epidermis) was measured. The muscular area of the legs and the posterior knee angle between the femur and tibia were also measured. The left hind legs were similarly assessed as nonirradiated controls. Group means and standard deviations were calculated and dose-response curves were drawn for every endpoint. Then, the dose modifying factor (DMF) for each endpoint and the correlations among endpoints were determined. Latae damage assayed by leg contracture and skin shrinkage progressed with increasing radiation dose. However, it was reduced by drug treatment. The significant effect was indicated for skin shrinkage by a DMF of 1.8 at 35%. The DMF for leg contracture was 1.3 at 6 mm. In the irradiated legs, epidermal hyperplasia and dermal fibrosis in the skin, muscular atrophy, and extension disturbance of the knee joint were observed. These changes progressed with increasing radiation dose. Skin damage assayed by the present endpoints was also reduced by drug treatment by DMFs of 1.4 to 1.7. However, DMFs for damage to the muscle and knee were not determined because no isoeffect was observed. There were good correlations between leg contracture or skin shrinkage and the other endpoints in both untreated and drug-treated mice. WR-151327 has the potential to protect against radiation-induced late normal tissue damage. 17 refs., 6 figs., 2 tabs.

  13. Titan's aerosol optical properties with VIMS observations at the limb

    NASA Astrophysics Data System (ADS)

    Rannou, Pascal; Seignovert, Benoit; Le Mouelic, Stephane; Sotin, Christophe

    2016-06-01

    The study of Titan properties with remote sensing relies on a good knowledge of the atmosphere properties. The in-situ observations made by Huygens combined with recent advances in the definition of methane properties enable to model and interpret observations with a very good accuracy. Thanks to these progresses, we can analyze in this work the observations made at the limb of Titan in order to retrieve information on the haze properties as its vertical profiles but also the spectral behaviour between 0.88 and 5.2 µm. To study the haze layer and more generally the source of opacities in the stratosphere, we use some observation made at the limb of Titan by the VIMS instrument onboard Cassini. We used a model in spherical geometry and in single scattering, and we accounted for the multiple scattering with a parallel plane model that evaluate the multiple scattering source function at the plane of the limb. Our scope is to retrieve informations about the vertical distribution of the haze, its spectral properties, but also to obtain details about the shape of the methane windows to desantangle the role of the methane and of the aerosols. We started our study at the latitude of 55°N, with a image taken in 2006 with a relatively high spatial resolution (for VIMS). Our preliminary results shows the spectral properties of the aerosols are the same whatever the altitude. This is a consequence of the large scale mixing. From limb profile between 0.9 and 5.2 µm, we can probe the haze layer from about 500 km (at 0.9 µm) to the ground (at 5.2 µm). We find that the vertical profile of the haze layer shows three distinct scale heights with transitions around 250 km and 350 km. We also clearly a transition around 70-90 km that may be due to the top of a condensation layer.

  14. Assessing upper limb function in nonambulant SMA patients: development of a new module.

    PubMed

    Mazzone, Elena; Bianco, Flaviana; Martinelli, Diego; Glanzman, Allan M; Messina, Sonia; De Sanctis, Roberto; Main, Marion; Eagle, Michelle; Florence, Julaine; Krosschell, Kristin; Vasco, Gessica; Pelliccioni, Marco; Lombardo, Marilena; Pane, Marika; Finkel, Richard; Muntoni, Francesco; Bertini, Enrico; Mercuri, Eugenio

    2011-06-01

    We report the development of a module specifically designed for assessing upper limb function in nonambulant SMA patients, including young children and those with severe contractures. The application of the module to a preschool cohort of 40 children (age 30-48 months) showed that all the items could be completed by 30 months. The module was also used in 45 nonambulant SMA patients (age 30 months to 27 years). Their scores were more variable than in the preschool cohort, ranging from 0 to 18. The magnitude of scores was not related to age (r=-0.19). The upper limb scores had a good correlation with the Hammersmith Functional Motor Scale, r=0.75, but the upper limb function did not always strictly follow the overall gross motor function. These findings suggest that even some of the very weak nonambulant children possess upper limb skills that can be measured.

  15. Calibration of the Microwave Limb Sounder on the Upper Atmosphere Research Satellite

    NASA Technical Reports Server (NTRS)

    Jarnot, R. F.; Cofield, R. E.; Waters, J. W.; Flower, D. A.; Peckham, G. E.

    1996-01-01

    The Microwave Limb Sounder (MLS) is a three-radiometer, passive, limb emission instrument onboard the Upper Atmosphere Research Satellite (UARS). Radiometric, spectral and field-of-view calibrations of the MLS instrument are described in this paper. In-orbit noise performance, gain stability, spectral baseline and dynamic range are described, as well as use of in-flight data for validation and refinement of prelaunch calibrations. Estimated systematic scaling uncertainties (3 sigma) on calibrated limb radiances from prelaunch calibrations are 2.6% in bands 1 through 3, 3.4% in band 4, and 6% in band 5. The observed systematic errors in band 6 are about 15%, consistent with prelaunch calibration uncertainties. Random uncertainties on individual limb radiance measurements are very close to the levels predicted from measured radiometer noise temperature, with negligible contribution from noise and drifts on the regular in-flight gain calibration measurements.

  16. The Floating Upper Limb: Multiple Injuries Involving Ipsilateral, Proximal, Humeral, Supracondylar, and Distal Radial Limb.

    PubMed

    Manaan, Qazi; Bashir, Adil; Zahoor, Adnan; Mokhdomi, Taseem A; Danish, Qazi

    2016-09-01

    Floating arm injury represents a common yet complicated injury of the childhood severely associated with limb deformation and even morbidity, if not precisely addressed and credibly operated. Here, we report a rare floating upper limb case of a 9-year-old boy with multiple injuries of ipsilateral proximal humeral, supracondylar and distal radial limb. This is the first report to document such a combined floating elbow and floating arm injury in the same limb. In this report, we discuss the surgical procedures used and recovery of the patient monitored to ascertain the effectiveness of the method in limb reorganisation.

  17. The Floating Upper Limb: Multiple Injuries Involving Ipsilateral, Proximal, Humeral, Supracondylar, and Distal Radial Limb

    PubMed Central

    Manaan, Qazi; Bashir, Adil; Zahoor, Adnan; Mokhdomi, Taseem A.

    2016-01-01

    Floating arm injury represents a common yet complicated injury of the childhood severely associated with limb deformation and even morbidity, if not precisely addressed and credibly operated. Here, we report a rare floating upper limb case of a 9-year-old boy with multiple injuries of ipsilateral proximal humeral, supracondylar and distal radial limb. This is the first report to document such a combined floating elbow and floating arm injury in the same limb. In this report, we discuss the surgical procedures used and recovery of the patient monitored to ascertain the effectiveness of the method in limb reorganisation. PMID:27583121

  18. Recipient twin limb ischemia with postnatal onset.

    PubMed

    Broadbent, Roland Spencer

    2007-02-01

    After the occurrence of 3 local cases of limb ischemia in newborn twins, we reviewed the literature to investigate this combination systematically. This review reveals a distinct condition: postnatal onset limb ischemia affecting recipient twins in twin-twin transfusion syndrome.

  19. 21 CFR 890.3475 - Limb orthosis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Limb orthosis. 890.3475 Section 890.3475 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3475 Limb orthosis. (a)...

  20. 21 CFR 890.3475 - Limb orthosis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Limb orthosis. 890.3475 Section 890.3475 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3475 Limb orthosis. (a)...

  1. 21 CFR 890.3475 - Limb orthosis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Limb orthosis. 890.3475 Section 890.3475 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3475 Limb orthosis. (a)...

  2. 21 CFR 890.3475 - Limb orthosis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Limb orthosis. 890.3475 Section 890.3475 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3475 Limb orthosis. (a)...

  3. 21 CFR 890.3475 - Limb orthosis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Limb orthosis. 890.3475 Section 890.3475 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3475 Limb orthosis. (a)...

  4. Newborn with Gastroschisis associated with Limb Anomalies

    PubMed Central

    Win, Phyu Phyu

    2017-01-01

    Gastroschisis is often found together with other extra intestinal conditions such as limb, spine, cardiac, central nervous system and genitourinary abnormalities. There are reports of its association with young maternal age. The cases presented here highlight the association of gastroschisis with limbs anomalies and young maternal age. PMID:28083494

  5. The aneurogenic limb identifies developmental cell interactions underlying vertebrate limb regeneration.

    PubMed

    Kumar, Anoop; Delgado, Jean-Paul; Gates, Phillip B; Neville, Graham; Forge, Andrew; Brockes, Jeremy P

    2011-08-16

    The removal of the neural tube in salamander embryos allows the development of nerve-free aneurogenic limbs. Limb regeneration is normally nerve-dependent, but the aneurogenic limb regenerates without nerves and becomes nerve-dependent after innervation. The molecular basis for these tissue interactions is unclear. Anterior Gradient (AG) protein, previously shown to rescue regeneration of denervated limbs and to act as a growth factor for cultured limb blastemal cells, is expressed throughout the larval limb epidermis and is down-regulated by innervation. In an aneurogenic limb, the level of AG protein remains high in the epidermis throughout development and regeneration, but decreases after innervation following transplantation to a normal host. Aneurogenic epidermis also shows a fivefold difference in secretory gland cells, which express AG protein. The persistently high expression of AG in the epithelial cells of an aneurogenic limb ensures that regeneration is independent of the nerve. These findings provide an explanation for this classical problem, and identify regulation of the epidermal niche by innervation as a distinctive developmental mechanism that initiates the nerve dependence of limb regeneration. The absence of this regulation during anuran limb development might suggest that it evolved in relation to limb regeneration.

  6. Limb pain in migraine and cluster headache.

    PubMed Central

    Guiloff, R J; Fruns, M

    1988-01-01

    Upper limb pain occurred in close temporal association with attacks of migraine, cluster headache and cluster-migraine in 22 cases. Seven had also lower limb pain. Limb pain was usually ipsilateral to the headache but could alternate sides and behaved like other accepted migraine accompaniments. It was always ipsilateral to the associated paraesthesiae/numbness (9 cases) and weakness (6 cases). The distribution and restricted localisations of limb pain were similar to those of the sensory symptoms and could not be accounted for by primary dysfunction of the peripheral or autonomic nervous systems. A central origin for limb pain is postulated. A temporary dysfunction in the somatosensory cortex, and/or its thalamic connections, during migraine or cluster headache attacks, might mediate such pain in a number of patients. PMID:3216204

  7. Slow Movements of Bio-Inspired Limbs

    NASA Astrophysics Data System (ADS)

    Babikian, Sarine; Valero-Cuevas, Francisco J.; Kanso, Eva

    2016-10-01

    Slow and accurate finger and limb movements are essential to daily activities, but the underlying mechanics is relatively unexplored. Here, we develop a mathematical framework to examine slow movements of tendon-driven limbs that are produced by modulating the tendons' stiffness parameters. Slow limb movements are driftless in the sense that movement stops when actuations stop. We demonstrate, in the context of a planar tendon-driven system representing a finger, that the control of stiffness suffices to produce stable and accurate limb postures and quasi-static (slow) transitions among them. We prove, however, that stable postures are achievable only when tendons are pretensioned, i.e., they cannot become slack. Our results further indicate that a non-smoothness in slow movements arises because the precision with which individual stiffnesses need to be altered changes substantially throughout the limb's motion.

  8. Planar cell polarity in vertebrate limb morphogenesis.

    PubMed

    Gao, Bo; Yang, Yingzi

    2013-08-01

    Studies of the vertebrate limb development have contributed significantly to understanding the fundamental mechanisms underlying growth, patterning, and morphogenesis of a complex multicellular organism. In the limb, well-defined signaling centers interact to coordinate limb growth and patterning along the three axes. Recent analyses of live imaging and mathematical modeling have provided evidence that polarized cell behaviors governed by morphogen gradients play an important role in shaping the limb bud. Furthermore, the Wnt/planar cell polarity (PCP) pathway that controls uniformly polarized cell behaviors in a field of cells has emerged to be critical for directional morphogenesis in the developing limb. Directional information coded in the morphogen gradient may be interpreted by responding cells through regulating the activities of PCP components in a Wnt morphogen dose-dependent manner.

  9. On stellar limb darkening and exoplanetary transits

    NASA Astrophysics Data System (ADS)

    Howarth, Ian D.

    2011-12-01

    This paper examines how to compare stellar limb-darkening coefficients evaluated from model atmospheres with those derived from photometry. Different characterizations of a given model atmosphere can give quite different numerical results (even for a given limb-darkening 'law'), while light-curve analyses yield limb-darkening coefficients that are dependent on system geometry, and that are not directly comparable to any model-atmosphere representation. These issues are examined in the context of exoplanetary transits, which offer significant advantages over traditional binary-star eclipsing systems in the study of stellar limb darkening. 'Like for like' comparisons between light-curve analyses and new model-atmosphere results, mediated by synthetic photometry, are conducted for a small sample of stars. Agreement between the resulting synthetic-photometry/atmosphere-model (SPAM) limb-darkening coefficients and empirical values ranges from very good to quite poor, even though the targets investigated show only a small dispersion in fundamental stellar parameters.

  10. [Psychological adjustment following lower limb amputation].

    PubMed

    Panyi, Lilla Krisztina; Lábadi, Beatrix

    2015-09-27

    Rehabilitation of lower limb amputees and the fitting of their prosthesis depend highly on the psychological adjustment process and motivational state of the patient. The loss of a limb is extremely challenging and can cause various physical and psychological problems. Depression, anxiety, decreased well-being and quality of life, body image dissatisfaction and changes in self-concept and identity are frequent after lower limb amputation. In the interest of adjustment patients have to cope with the emerging changes and difficulties in their lifes as well as the problems in psychological functioning. It is important for them to accept the alterations in their body and identity, and integrate them in a new self-concept in which process motivation is a fundamental issue. The aim of this article is to review the literature on psychological consequences of lower limb amputation, and to propose an integrative way of rehabilitation for lower limb amputees.

  11. Planar Cell Polarity in vertebrate limb morphogenesis

    PubMed Central

    Gao, Bo; Yang, Yingzi

    2013-01-01

    Studies of the vertebrate limb development have contributed significantly to understanding the fundamental mechanisms underlying growth, patterning and morphogenesis of a complex multicellular organism. In the limb, well-defined signaling centers interact to coordinate limb growth and patterning along the three axes. Recent analyses of live imaging and mathematical modeling have provided evidence that polarized cell behaviors governed by morphogen gradients play an important role in shaping the limb bud. Furthermore, the Wnt/Planar Cell Polarity (PCP) pathway that controls uniformly polarized cellular behaviors in a field of cells has emerged to be critical for directional morphogenesis in the developing limb. Directional information coded in the morphogen gradient may be interpreted by responding cells through regulating the activities of PCP components in a Wnt morphogen dose-dependent manner. PMID:23747034

  12. Molecular basis of vertebrate limb patterning.

    PubMed

    Tickle, Cheryll

    2002-10-15

    Mechanisms of limb development are common to all higher vertebrates. The current understanding of how vertebrate limbs develop comes mainly from studies on chick embryos, which are classical models for experimental manipulation, and mouse embryos, which can be genetically manipulated. Work on chick and mouse embryos is often complementary and has direct implications for human limb development. Analysis has moved to the molecular level, which allows direct links to genetics. Even though genes involved in limb development have been discovered by basic scientists through different routes to that taken by clinical geneticists, many of the same genes have been identified. Thus, the fields of embryology and clinical medicine increasingly converge. The next challenge will be to go back to animal models to begin to dissect how particular gene mutations lead to specific limb phenotypes.

  13. Saunders's framework for understanding limb development as a platform for investigating limb evolution.

    PubMed

    Young, John J; Tabin, Clifford J

    2016-11-11

    John W. Saunders, Jr. made seminal discoveries unveiling how chick embryos develop their limbs. He discovered the apical ectodermal ridge (AER), the zone of polarizing activity (ZPA), and the domains of interdigital cell death within the developing limb and determined their function through experimental analysis. These discoveries provided the basis for subsequent molecular understanding of how vertebrate limbs are induced, patterned, and differentiated. These mechanisms are strongly conserved among the vast diversity of tetrapod limbs suggesting that relatively minor changes and tweaks to the molecular cascades are responsible for the diversity observed in nature. Analysis of the pathway systems first identified by Saunders in the context of animals displaying limb reduction show how alterations in these pathways have resulted in multiple mechanisms of limb and digit loss. Other classes of modification to these same patterning systems are seen at the root of other, novel limb morphological alterations and elaborations.

  14. Threatened limb from stingray injury.

    PubMed

    Shiraev, Timothy P; Marucci, Damian; McMullin, Gabrielle

    2016-01-01

    We present the case of a 43-year-old female who suffered a stingray injury to her left ankle. The sting caused occlusion of the dorsalis pedis artery, causing dry gangrene of the medial forefoot. A below knee amputation was recommended but she was transferred for a second opinion. A Prostaglandin E1 infusion was commenced, resulting in alleviation of pain and improvement in perfusion. Amputation of great and second toes was performed, with the head of the first metatarsal preserved and covered via a cross-over skin flap raised from the contralateral leg. Achilles tendon lengthening was then performed to return the foot to a functional position. This case serves to highlight the utility of prostaglandin infusion, and the requirement for a multidisciplinary approach to critical limb ischemia in order to avoid major amputation.

  15. Sonic Hedgehog Signaling in Limb Development

    PubMed Central

    Tickle, Cheryll; Towers, Matthew

    2017-01-01

    The gene encoding the secreted protein Sonic hedgehog (Shh) is expressed in the polarizing region (or zone of polarizing activity), a small group of mesenchyme cells at the posterior margin of the vertebrate limb bud. Detailed analyses have revealed that Shh has the properties of the long sought after polarizing region morphogen that specifies positional values across the antero-posterior axis (e.g., thumb to little finger axis) of the limb. Shh has also been shown to control the width of the limb bud by stimulating mesenchyme cell proliferation and by regulating the antero-posterior length of the apical ectodermal ridge, the signaling region required for limb bud outgrowth and the laying down of structures along the proximo-distal axis (e.g., shoulder to digits axis) of the limb. It has been shown that Shh signaling can specify antero-posterior positional values in limb buds in both a concentration- (paracrine) and time-dependent (autocrine) fashion. Currently there are several models for how Shh specifies positional values over time in the limb buds of chick and mouse embryos and how this is integrated with growth. Extensive work has elucidated downstream transcriptional targets of Shh signaling. Nevertheless, it remains unclear how antero-posterior positional values are encoded and then interpreted to give the particular structure appropriate to that position, for example, the type of digit. A distant cis-regulatory enhancer controls limb-bud-specific expression of Shh and the discovery of increasing numbers of interacting transcription factors indicate complex spatiotemporal regulation. Altered Shh signaling is implicated in clinical conditions with congenital limb defects and in the evolution of the morphological diversity of vertebrate limbs. PMID:28293554

  16. Sonic Hedgehog Signaling in Limb Development.

    PubMed

    Tickle, Cheryll; Towers, Matthew

    2017-01-01

    The gene encoding the secreted protein Sonic hedgehog (Shh) is expressed in the polarizing region (or zone of polarizing activity), a small group of mesenchyme cells at the posterior margin of the vertebrate limb bud. Detailed analyses have revealed that Shh has the properties of the long sought after polarizing region morphogen that specifies positional values across the antero-posterior axis (e.g., thumb to little finger axis) of the limb. Shh has also been shown to control the width of the limb bud by stimulating mesenchyme cell proliferation and by regulating the antero-posterior length of the apical ectodermal ridge, the signaling region required for limb bud outgrowth and the laying down of structures along the proximo-distal axis (e.g., shoulder to digits axis) of the limb. It has been shown that Shh signaling can specify antero-posterior positional values in limb buds in both a concentration- (paracrine) and time-dependent (autocrine) fashion. Currently there are several models for how Shh specifies positional values over time in the limb buds of chick and mouse embryos and how this is integrated with growth. Extensive work has elucidated downstream transcriptional targets of Shh signaling. Nevertheless, it remains unclear how antero-posterior positional values are encoded and then interpreted to give the particular structure appropriate to that position, for example, the type of digit. A distant cis-regulatory enhancer controls limb-bud-specific expression of Shh and the discovery of increasing numbers of interacting transcription factors indicate complex spatiotemporal regulation. Altered Shh signaling is implicated in clinical conditions with congenital limb defects and in the evolution of the morphological diversity of vertebrate limbs.

  17. Management of Critical Limb Ischemia

    PubMed Central

    Kinlay, Scott

    2016-01-01

    Critical limb ischemia (CLI) is a clinical syndrome of ischemic pain at rest or tissue loss, such as non-healing ulcers or gangrene, related to peripheral artery disease. CLI has a high short-term risk of limb loss and cardiovascular events. Non-invasive or invasive angiography help determine the feasibility and approach to arterial revascularization. An “endovascular-first” approach is often advocated based on a lower procedural risk, however, specific patterns of disease may be best treated by open surgical revascularization. Balloon angioplasty and stenting form the backbone of endovascular techniques, with drug-eluting stents and drug-coated balloons offering low rates of repeat revascularization. Combined antegrade and retrograde approaches can increase success in long total occlusions. Below the knee, angiosome-directed angioplasty may lead to greater wound healing, but failing this, any straight line flow into the foot is pursued. Hybrid surgical techniques such as iliac stenting and common femoral endarterectomy are commonly used to reduce operative risk. Lower extremity bypass grafting is most successful with a good quality, long, single-segment autogenous vein of at least 3.5mm diameter. Minor amputations are often required for tissue loss as part of the treatment strategy. Major amputations (at or above the ankle) limit functional independence and their prevention is a key goal of CLI therapy. Medical therapy after revascularization targets risk factors for atherosclerosis and assesses wound healing and new or recurrent flow limiting disease. The ongoing NIH sponsored BEST-CLI study is a randomized trial of the contemporary endovascular versus open surgical techniques in patients with CLI. PMID:26858079

  18. Insights into the dynamics of hind leg development in honey bee (Apis mellifera L.) queen and worker larvae - A morphology/differential gene expression analysis

    PubMed Central

    Santos, Carolina Gonçalves; Hartfelder, Klaus

    2015-01-01

    Phenotypic plasticity is a hallmark of the caste systems of social insects, expressed in their life history and morphological traits. These are best studied in bees. In their co-evolution with angiosperm plants, the females of corbiculate bees have acquired a specialized structure on their hind legs for collecting pollen. In the highly eusocial bees (Apini and Meliponini), this structure is however only present in workers and absent in queens. By means of histological sections and cell proliferation analysis we followed the developmental dynamics of the hind legs of queens and workers in the fourth and fifth larval instars. In parallel, we generated subtractive cDNA libraries for hind leg discs of queen and worker larvae by means of a Representational Difference Analysis (RDA). From the total of 135 unique sequences we selected 19 for RT-qPCR analysis, where six of these were confirmed as differing significantly in their expression between the two castes in the larval spinning stage. The development of complex structures such as the bees’ hind legs, requires diverse patterning mechanisms and signaling modules, as indicated by the set of differentially expressed genes related with cell adhesion and signaling pathways. PMID:26500430

  19. Fatty liver accompanies an increase of Lactobacillus acidophilus in the hind gut of C57/BL mice fed a high-fat diet

    Technology Transfer Automated Retrieval System (TEKTRAN)

    High-fat diets can produce obesity and have been linked to the development of nonalcoholic fatty liver disease (NAFLD), which also induces changes in the gut microbiome. This study tested the hypothesis that high-fat feeding increases certain predominate hind gut bacteria in a C57BL/6 mouse model o...

  20. Remote Limb Ischemic Postconditioning Protects Against Neonatal Hypoxic–Ischemic Brain Injury in Rat Pups by the Opioid Receptor/Akt Pathway

    PubMed Central

    Zhou, Yilin; Fathali, Nancy; Lekic, Tim; Ostrowski, Robert P.; Chen, Chunhua; Martin, Robert D.; Tang, Jiping; Zhang, John H.

    2013-01-01

    Background and Purpose Remote ischemic postconditoning, a phenomenon in which brief ischemic stimuli of 1 organ protect another organ against an ischemic insult, has been demonstrated to protect the myocardium and adult brain in animal models. However, mediators of the protection and underlying mechanisms remain to be elucidated. In the present study, we tested the hypothesis that remote limb ischemic postconditioning applied immediately after hypoxia provides neuroprotection in a rat model of neonatal hypoxia–ischemia (HI) by mechanisms involving activation of the opioid receptor/phosphatidylinositol-3-kinase/Akt signaling pathway. Methods HI was induced in postnatal Day 10 rat pups by unilateral carotid ligation and 2 hours of hypoxia. Limb ischemic postconditioning was induced by 4 conditioning cycles of 10 minutes of ischemia and reperfusion on both hind limbs immediately after HI. The opioid antagonist naloxone, phosphatidylinositol-3-kinase inhibitor wortmannin, or opioid agonist morphine was administered to determine underlying mechanisms. Infarct volume, brain atrophy, and neurological outcomes after HI were evaluated. Expression of phosphorylated Akt, Bax, and phosphorylated ERK1/2 was determined by Western blotting. Results Limb ischemic postconditioning significantly reduced infarct volume at 48 hours and improved functional outcomes at 4 weeks after HI. Naloxone and wortmannin abrogated the postconditioning-mediated infarct-limiting effect. Morphine given immediately after hypoxia also decreased infarct volume. Furthermore, limb ischemic postconditioning recovered Akt activity and decreased Bax expression, whereas no differences in phosphorylated ERK1/2expression were observed. Conclusions Limb ischemic postconditioning protects against neonatal HI brain injury in rats by activating the opioid receptor/phosphatidylinositol-3-kinase/Akt signaling pathway. PMID:21183744

  1. Short-term outcomes of en bloc resection of solitary bone metastases in limbs

    PubMed Central

    Yang, Qingcheng; Zhao, Bizeng; Zhang, Zhichang; Dong, Yang; Pan, Yao; Du, Xinhui

    2012-01-01

    Summary Background To evaluate the pain, quality of life (QOL), and limb function of patients after en bloc resection of solitary metastatic bone cancer in the limbs. Material/Methods A total of 27 patients with solitary metastatic bone cancer in the limbs were recruited. All these patients underwent limb-salvage surgery with en bloc resection of the metastatic tumor. Pain and QOL were evaluated before and after surgery. Pain was assessed with a 10-point scale before and 1 month after surgery. The QOL was evaluated with the SF-30 scale before and 3 months after surgery. Limb function was evaluated with the Musculoskeletal Tumor Society scale (MSTS) 3 months after surgery. Follow-up was performed for 6~31 months (mean: 16.15±7.47 months). Results All procedures were successfully performed. Post-operative complications were found in 6 patients, including incision infection, prosthesis dislocation, deep vein thrombosis, and pulmonary infection. The pain score before and 1 month after surgery was 6.85±3.11 and 1.26±0.81, respectively, indicating obvious improvement (t=9.978, P<0.001). The QOL score before and 3 months after surgery was 38.30±13.05 and 65.78±10.65, respectively, indicating pronounced improvement (t=−18.550, P<0.001). The mean post-operative MSTS score was 23±3 (range: 17–30) (t=−1.450, P=0.016). No local recurrence was observed in any patient during the follow-up. Conclusions Limb salvage surgery with wide or marginal resection for solitary metastatic bone cancer may significantly improve the pain, QOL, and limb function, but there is no difference in local control between wide and marginal resection. PMID:23111740

  2. Single centre experience of the upper limb replantation and revascularisation.

    PubMed

    Visnjic, Milan M; Kovacevic, Predrag T; Paunkovic, Ljiljana M; Milenkovic, Sasa S

    2004-01-01

    Replantation is defined as reattachment of the amputated limb using the neurovascular and musculoskeletal structures in order to obtain the recovery of the limb. Fortunately, injuries causing limb amputation are rare. Adequate treatment within the optimal time scale can provide successful rehabilitation of the shape and function of the replanted part. We report the experience of our Clinical Centre (regional replantation centre) in the replantation of five forearms/hands and revascularisation of six hands between 1997 and 2001. The most frequent site of injury was the distal part of the forearm, while the major cause of injuries was a wood processing machine. The surgical procedures were performed under general anaesthesia within 2-6 hours after injury. Vascular anastomoses, nerve repair and muscle repair were performed following the external bone fixation. All patients were given anticoagulation treatment postoperatively. Thrombosis in the anastomotic site developed as an early complication in two patients who underwent thrombectomy; one of these patients developed gangrene and underwent amputation. Late postoperative results were good in 10 patients. One patient developed acral epidermolysis. Postoperative results after revascularisation were good in all patients.

  3. Limb apraxia in acute ischemic stroke: a neglected clinical challenge?

    PubMed

    Schell, Caroline; Suchan, Julia; Himmelbach, Marc; Haarmeier, Thomas; Borchers, Svenja

    2014-04-01

    Symptoms of limb apraxia and executive dysfunctions are currently not explicitly considered by the National Institutes of Health Stroke Scale and, thus, not routinely tested by clinicians in the acute care of patients with suspected stroke. Neuropsychological testing, clinical examination, MRI, and functional magnetic resonance imaging (fMRI) were performed in a right-handed patient with acute onset of left-sided sensorimotor hemiparesis due to a right hemisphere ischemic stroke. Deficits in the execution of meaningless and meaningful gestures were not detected properly on initial clinical examination but were revealed later on through neuropsychological testing. Instead, the patient's inability to respond to specific instructions in the acute care setting was mistaken to reflect severe deficits in auditory comprehension. fMRI revealed right-hemispheric localization of language in the right-handed patient. We suggest including a bedside test for limb apraxia symptoms in acute clinical care of stroke patients. The distinction between deficits in limb praxis and impairments of language can be complicated owing to the common hemispheric co-localization of the two functions.

  4. The functional anatomy of suggested limb paralysis.

    PubMed

    Deeley, Quinton; Oakley, David A; Toone, Brian; Bell, Vaughan; Walsh, Eamonn; Marquand, Andre F; Giampietro, Vincent; Brammer, Michael J; Williams, Steven C R; Mehta, Mitul A; Halligan, Peter W

    2013-02-01

    Suggestions of limb paralysis in highly hypnotically suggestible subjects have been employed to successfully model conversion disorders, revealing similar patterns of brain activation associated with attempted movement of the affected limb. However, previous studies differ with regard to the executive regions involved during involuntary inhibition of the affected limb. This difference may have arisen as previous studies did not control for differences in hypnosis depth between conditions and/or include subjective measures to explore the experience of suggested paralysis. In the current study we employed functional magnetic resonance imaging (fMRI) to examine the functional anatomy of left and right upper limb movements in eight healthy subjects selected for high hypnotic suggestibility during (i) hypnosis (NORMAL) and (ii) attempted movement following additional left upper limb paralysis suggestions (PARALYSIS). Contrast of left upper limb motor function during NORMAL relative to PARALYSIS conditions revealed greater activation of contralateral M1/S1 and ipsilateral cerebellum, consistent with the engagement of these regions in the completion of movements. By contrast, two significant observations were noted in PARALYSIS relative to NORMAL conditions. In conjunction with reports of attempts to move the paralysed limb, greater supplementary motor area (SMA) activation was observed, a finding consistent with the role of SMA in motor intention and planning. The anterior cingulate cortex (ACC, BA 24) was also significantly more active in PARALYSIS relative to NORMAL conditions - suggesting that ACC (BA 24) may be implicated in involuntary, as well as voluntary inhibition of prepotent motor responses.

  5. TES Limb-Geometry Observations of Aerosols

    NASA Technical Reports Server (NTRS)

    Smith, Michael D.

    2003-01-01

    The Thermal Emission Spectrometer (TES) on-board Mars Global Surveyor (MGS) has a pointing mirror that allows observations in the plane of the orbit anywhere from directly nadir to far above either the forward or aft limbs for details about the TES instrument). Nadir-geometry observations are defined as those where the field-of-view contains the surface of Mars (even if the actual observation is at a high emission angle far from true nadir). Limb-geometry observations are defined as those where the line-of-sight of the observations does not intersect the surface. At a number of points along the MGS orbit (typically every 10 deg. or 20 deg. of latitude) a limb sequence is taken, which includes a stack of overlapping TES spectra from just below the limb to more than 120 km above the limb. A typical limb sequence has approx. 20 individual spectra, and the projected size of a TES pixel at the limb is 13 km.

  6. The mangled limb: salvage versus amputation.

    PubMed

    Wolinsky, Philip R; Webb, Lawrence X; Harvey, Edward J; Tejwani, Nirmal C

    2011-01-01

    A mangled extremity is defined as a limb with injury to three of four systems in the extremity. The decision to salvage or amputate the injured limb has generated much controversy in the literature, with studies to support advantages of each approach. Various scoring systems have proved unreliable in predicting the need for amputation or salvage; however, a recurring theme in the literature is that the key to limb viability seems to be the severity of the soft-tissue injury. Factors such as associated injuries, patient age, and comorbidities (such as diabetes) also should be considered. Attempted limb salvage should be considered only if a patient is hemodynamically stable enough to tolerate the necessary surgical procedures and blood loss associated with limb salvage. For persistently hemodynamically unstable patients and those in extremis, life comes before limb. Recently, the Lower Extremity Assessment Project study attempted to answer the question of whether amputation or limb salvage achieves a better outcome. The study also evaluated other factors, including return-to-work status, impact of the level of and bilaterality of the amputation, and economic cost. There appears to be no significant difference in return to work, functional outcomes, or the cost of treatment (including the prosthesis) between the two groups. A team approach with different specialties, including orthopaedics, plastic surgery, vascular surgery and trauma general surgery, is recommended for treating patients with a mangled extremity.

  7. The Mars Express limbs observations database

    NASA Astrophysics Data System (ADS)

    Gondet, Brigitte; Bibring, Jean-Pierre; Montmessin, Franck; Giuranna, Marco; Hoffmann, Harald; Cardesin, Alejandro

    2015-04-01

    The capability to orient Mars Express allows a great diversity of observations modes, in particular nadir and limb. During day and night limb's observations, 4 out of 7 MEX instruments (the spectrometers: SPICAM, OMEGA, PFS and the high-resolution camera HRSC) work together to provide spectra (.12 µm to 45 µm) of the Martian atmosphere, at each altitude step, with the associated image. We will present the limbs database of more than 10 years in orbit with striking results (dust and clouds detached layers, day and night emissions). The database is now accessible to the scientific community via the ESA/PSA website (www.rssd.esa.int/PSA).

  8. A newborn with unilateral limb enlargement.

    PubMed

    Sharma, Shanel; Maino, Anna P F; Husain, Shad M; Adams, Gill G W

    2012-03-01

    On routine neonatal examination, a newborn term male was noted to have unilateral enlargement of the right lower limb, loose thickened red skin over the palm and widening of all the fingers on the right hand. His body was pinker and warmer on the right side compared with the left and he had a right undescended testicle and hypoplastic scrotum. Radiological examination of the lower limbs demonstrated the enlargement of the soft tissue of the right lower limb compared to the left (Fig. 1). Therefore, the diagnosis was unclear from this constellation of findings and an ophthalmic assessment was requested.

  9. Growing models of vertebrate limb development.

    PubMed

    Towers, Matthew; Tickle, Cheryll

    2009-01-01

    The developing limb has been a very influential system for studying pattern formation in vertebrates. In the past, classical embryological models have explained how patterned structures are generated along the two principal axes of the limb: the proximodistal (shoulder to finger) and anteroposterior (thumb to little finger) axes. Over time, the genetic and molecular attributes of these patterning models have been discovered, while the role of growth in the patterning process has been only recently highlighted. In this review, we discuss these recent findings and propose how the various models of limb patterning can be reconciled.

  10. Systematic Literature Review of AbobotulinumtoxinA in Clinical Trials for Lower Limb Spasticity.

    PubMed

    Dashtipour, Khashayar; Chen, Jack J; Walker, Heather W; Lee, Michael Y

    2016-01-01

    To elucidate clinical trial efficacy, safety, and dosing practices of AbobotulinumtoxinA (ABO) treatment in adult patients with lower limb spasticity.A systematic literature review was performed to identify randomized controlled trials of ABO in the treatment of adult lower limb spasticity.Of the 295 records identified, 6 primary publications evaluated ABO for the management of lower limb spasticity of various etiologies and were evaluated. Total ABO doses ranged between 500 and 2000 U for lower limb spasticity, depending on the muscles injected. All studies in lower limb spasticity showed statistically significant reduction in muscle tone based on Modified Ashworth Scale of ABO versus placebo. Significant effects on active movement and pain were demonstrated albeit less consistently. ABO was generally well tolerated across the individual studies; most adverse events reported were considered unrelated to treatment. Treatment-related adverse events included but not limited to fatigue, local pain at injection site, hypertonia, dry mouth, weakness of the noninjected muscle, abnormal gait, and urinary tract infection.These data from 6 randomized clinical studies provide the beginnings of an evidence base for the use of ABO to reduce lower limb spasticity. Ongoing studies in this area will add to this evidence base.

  11. Two-dimensional radiative transfer for the retrieval of limb emission measurements in the martian atmosphere

    NASA Astrophysics Data System (ADS)

    Kleinböhl, Armin; Friedson, A. James; Schofield, John T.

    2017-01-01

    The remote sounding of infrared emission from planetary atmospheres using limb-viewing geometry is a powerful technique for deriving vertical profiles of structure and composition on a global scale. Compared with nadir viewing, limb geometry provides enhanced vertical resolution and greater sensitivity to atmospheric constituents. However, standard limb profile retrieval techniques assume spherical symmetry and are vulnerable to biases produced by horizontal gradients in atmospheric parameters. We present a scheme for the correction of horizontal gradients in profile retrievals from limb observations of the martian atmosphere. It characterizes horizontal gradients in temperature, pressure, and aerosol extinction along the line-of-sight of a limb view through neighboring measurements, and represents these gradients by means of two-dimensional radiative transfer in the forward model of the retrieval. The scheme is applied to limb emission measurements from the Mars Climate Sounder instrument on Mars Reconnaissance Orbiter. Retrieval simulations using data from numerical models indicate that biases of up to 10 K in the winter polar region, obtained with standard retrievals using spherical symmetry, are reduced to about 2 K in most locations by the retrieval with two-dimensional radiative transfer. Retrievals from Mars atmospheric measurements suggest that the two-dimensional radiative transfer greatly reduces biases in temperature and aerosol opacity caused by observational geometry, predominantly in the polar winter regions.

  12. A bioinformatics expert system linking functional data to anatomical outcomes in limb regeneration

    PubMed Central

    Lobo, Daniel; Feldman, Erica B.; Shah, Michelle; Malone, Taylor J.

    2014-01-01

    Abstract Amphibians and molting arthropods have the remarkable capacity to regenerate amputated limbs, as described by an extensive literature of experimental cuts, amputations, grafts, and molecular techniques. Despite a rich history of experimental effort, no comprehensive mechanistic model exists that can account for the pattern regulation observed in these experiments. While bioinformatics algorithms have revolutionized the study of signaling pathways, no such tools have heretofore been available to assist scientists in formulating testable models of large‐scale morphogenesis that match published data in the limb regeneration field. Major barriers to preventing an algorithmic approach are the lack of formal descriptions for experimental regenerative information and a repository to centralize storage and mining of functional data on limb regeneration. Establishing a new bioinformatics of shape would significantly accelerate the discovery of key insights into the mechanisms that implement complex regeneration. Here, we describe a novel mathematical ontology for limb regeneration to unambiguously encode phenotype, manipulation, and experiment data. Based on this formalism, we present the first centralized formal database of published limb regeneration experiments together with a user‐friendly expert system tool to facilitate its access and mining. These resources are freely available for the community and will assist both human biologists and artificial intelligence systems to discover testable, mechanistic models of limb regeneration. PMID:25729585

  13. A new model predicting locomotor cost from limb length via force production.

    PubMed

    Pontzer, Herman

    2005-04-01

    Notably absent from the existing literature is an explicit biomechanical model linking limb design to the energy cost of locomotion, COL. Here, I present a simple model that predicts the rate of force production necessary to support the body and swing the limb during walking and running as a function of speed, limb length, limb proportion, excursion angle and stride frequency. The estimated rate of force production is then used to predict COL via this model following previous studies that have linked COL to force production. To test this model, oxygen consumption and kinematics were measured in nine human subjects while walking and running on a treadmill at range of speeds. Following the model, limb length, speed, excursion angle and stride frequency were used to predict the rate of force production both to support the body's center of mass and to swing the limb. Model-predicted COL was significantly correlated with observed COL, performing as well or better than contact time and Froude number as a predictor of COL for running and walking, respectively. Furthermore, the model presented here predicts relationships between COL, kinematic variables and body size that are supported by published reduced-gravity experiments and scaling studies. Results suggest the model is useful for predicting COL from anatomical and kinematic variables, and may be useful in intra- and inter-specific studies of locomotor anatomy and performance.

  14. Major ozonated autohemotherapy promotes the recovery of upper limb motor function in patients with acute cerebral infarction★

    PubMed Central

    Wu, Xiaona; Li, Zhensheng; Liu, Xiaoyan; Peng, Haiyan; Huang, Yongjun; Luo, Gaoquan; Peng, Kairun

    2013-01-01

    Major ozonated autohemotherapy is classically used in treating ischemic disorder of the lower limbs. In the present study, we performed major ozonated autohemotherapy treatment in patients with acute cerebral infarction, and assessed outcomes according to the U.S. National Institutes of Health Stroke Score, Modified Rankin Scale, and transcranial magnetic stimulation motor-evoked potential. Compared with the control group, the clinical total effective rate and the cortical potential rise rate of the upper limbs were significantly higher, the central motor conduction time of upper limb was significantly shorter, and the upper limb motor-evoked potential amplitude was significantly increased, in the ozone group. In the ozone group, the National Institutes of Health Stroke Score was positively correlated with the central motor conduction time and the motor-evoked potential amplitude of the upper limb. Central motor conduction time and motor-evoked potential amplitude of the upper limb may be effective indicators of motor-evoked potentials to assess upper limb motor function in cerebral infarct patients. Furthermore, major ozonated autohemotherapy may promote motor function recovery of the upper limb in patients with acute cerebral infarction. PMID:25206688

  15. Upper limb module in non-ambulant patients with spinal muscular atrophy: 12 month changes.

    PubMed

    Sivo, Serena; Mazzone, Elena; Antonaci, Laura; De Sanctis, Roberto; Fanelli, Lavinia; Palermo, Concetta; Montes, Jacqueline; Pane, Marika; Mercuri, Eugenio

    2015-03-01

    Recent studies have suggested that in non-ambulant patients affected by spinal muscular atrophy the Upper Limb Module can increase the range of activities assessed by the Hammersmith Functional Motor Scale Expanded. The aim of this study was to establish 12-month changes in the Upper Limb Module in a cohort of non-ambulant spinal muscular atrophy patients and their correlation with changes on the Hammersmith Functional Motor Scale Expanded. The Upper Limb Module scores ranged between 0 and 17 (mean 10.23, SD 4.81) at baseline and between 1 and 17 at 12 months (mean 10.27, SD 4.74). The Hammersmith Functional Motor Scale Expanded scores ranged between 0 and 34 (mean 12.43, SD 9.13) at baseline and between 0 and 34 at 12 months (mean 12.08, SD 9.21). The correlation betweeen the two scales was 0.65 at baseline and 0.72 on the 12 month changes. Our results confirm that the Upper Limb Module can capture functional changes in non-ambulant spinal muscular atrophy patients not otherwise captured by the other scale and that the combination of the two measures allows to capture changes in different subgroups of patients in whom baseline scores and functional changes may be influenced by several variables such as age.

  16. Venus cloud properties inferred from limb darkening curves

    NASA Astrophysics Data System (ADS)

    Longobardo, A.; Palomba, E.; Piccioni, G.; Zinzi, A.; Tsang, C. C. C.; Drossart, P.

    2011-10-01

    The limb darkening (LD) curve is the plot of radiance I as function of cosine of the emission angle (i.e. angle between the line of sight and the normal to the target). Its shape is related to atmospheric and cloud properties, such as opacity and scale height. These can be deduced also considering the plot of brightness temperature T as function of cos at some wavelengths [1,2]. In this work, Venus clouds have been studied by means of a LD study on infrared images of the Venus nightside, provided by the VIRTIS-Venus Express instrument [3].

  17. Transducers for ultrasonic limb plethysmography

    NASA Technical Reports Server (NTRS)

    Nickell, W. T.; Wu, V. C.; Bhagat, P. K.

    1983-01-01

    The design, construction, and performance characteristics of ultasonic transducers suitable for limb plethysmography are presented. Both 3-mm-diameter flat-plate and 12-mm-diameter hemispheric ceramic transducers operating at 2 MHz were fitted in 1-mm thick epoxy-resin lens/acoustic-coupling structures and mounted in exercie-EKG electrode housings for placement on the calf using adhesive collars. The effects of transducer directional characteristics on performance under off-axis rotation and the electrical impedances of the transducers were measured: The flat transducer was found to be sensitive to rotation and have an impedance of 800 ohms; the hemispheric transducer, to be unaffected by rotation and have an impedance of 80 ohms. The use of hemispheric transducers as both transmitter and receiver, or of a flat transducer as transmitter and a hemispheric transducer as receiver, was found to produce adequate dimensional measurements, with minimum care in transducer placement, in short-term physiological experiments and long-term (up to 7-day) attachment tests.

  18. Limb lengthening in Turner syndrome.

    PubMed

    Noonan, K J; Leyes, M; Forriol, F

    1997-01-01

    We report the results and complications of eight consecutive patients who underwent bilateral tibial lengthenings for dwarfism associated with Turner syndrome. Lengthening was performed via distraction osteogenesis with monolateral external fixation. Tibias were lengthened an average distance of 9.2 centimeters or 33 percent of the original tibial length. The average total treatment time was 268 days. The overall complication rate was 169 percent for each tibia lengthened and each segment required an average of 1.7 additional procedures. Seven cases (44 percent) required Achilles tendon lengthening and nine cases (56 percent) developed angulation before or after fixator removal; six of these segments required corrective osteotomy for axial malalignment. Two cases (12.5 percent) developed distraction site nonunion and required plating and bone grafting. From this series we conclude that tibial lengthening via distraction osteogenesis can be used to treat disproportionate short stature in patients with Turner syndrome. However, the benefit of a cosmetic increase in height may not compensate for the high complication rate. Efforts to determine the psychosocial and functional benefits of limb lengthening in patients with short stature is necessary to determine the true cost-benefit ratio of this procedure.

  19. Limb lengthening in Turner syndrome.

    PubMed Central

    Noonan, K. J.; Leyes, M.; Forriol, F.

    1997-01-01

    We report the results and complications of eight consecutive patients who underwent bilateral tibial lengthenings for dwarfism associated with Turner syndrome. Lengthening was performed via distraction osteogenesis with monolateral external fixation. Tibias were lengthened an average distance of 9.2 centimeters or 33 percent of the original tibial length. The average total treatment time was 268 days. The overall complication rate was 169 percent for each tibia lengthened and each segment required an average of 1.7 additional procedures. Seven cases (44 percent) required Achilles tendon lengthening and nine cases (56 percent) developed angulation before or after fixator removal; six of these segments required corrective osteotomy for axial malalignment. Two cases (12.5 percent) developed distraction site nonunion and required plating and bone grafting. From this series we conclude that tibial lengthening via distraction osteogenesis can be used to treat disproportionate short stature in patients with Turner syndrome. However, the benefit of a cosmetic increase in height may not compensate for the high complication rate. Efforts to determine the psychosocial and functional benefits of limb lengthening in patients with short stature is necessary to determine the true cost-benefit ratio of this procedure. Images Figure 1a Figure 1b Figure 1c PMID:9234980

  20. Laser Science and Limb Salvage.

    PubMed

    Friedman, Steven G

    2011-12-01

    Harnessing light energy in the form of lasers became possible after the discovery of electricity. Scientists found various uses for lasers beginning in the 1960s. Creating large amounts of pulsed UV light with any device, including a laser, remained difficult until excimer lasers were invented in the following decade. The invention of excimer lasers coincided with the advent of balloon angioplasty, leading physicians to speculate about using laser energy to obliterate obstructing arterial lesions. The first report of laser energy to vaporize an atherosclerotic plaque appeared in 1980. The ensuing decades witnessed dramatic refinements of laser fibers, laser energy sources, and catheter delivery systems. The favorable results achieved with excimer laser angioplasty in the early 2000s led to a renewed interest in this technology and to the current widespread use of these devices to treat peripheral as well as coronary artery disease. This paper provides a review of laser energy principles, traces the history of the use of lasers to treat vascular disease, and reviews the current literature pertaining to laser angioplasty and limb salvage.

  1. Residual limb skin temperature and thermal comfort in people with amputation during activity in a cold environment.

    PubMed

    Segal, Ava D; Klute, Glenn K

    2016-01-01

    Thermal comfort remains a common problem for people with lower-limb amputation. Both donning a prosthesis and engaging in activity at room temperature can increase residual limb skin temperature; however, the effects of activity on skin temperature and comfort in more extreme environments remain unknown. We examined residual limb skin temperatures and perceived thermal comfort (PTC; 11-point Likert scale) of participants with unilateral transtibial amputation (n = 8) who were snowshoeing in a cold environment. Residual limb skin temperature increased by 3.9°C [3.0°C to 4.7°C] (mean difference [95% confidence interval (CI)], p < 0.001) after two 30 min exercise sessions separated by a 5 min rest session. Minimal cooling (-0.2°C [-1.1°C to 0.6°C]) occurred during the rest period. Similar changes in PTC were found for the residual limb, intact limb, and whole body, with a mean scale increase of 1.6 [1.1 to 2.1] and 1.3 [0.8 to 1.8] for the first and second exercise sessions, respectively (p < 0.001). Activity in a cold environment caused similar increases in residual limb skin temperature as those found in studies conducted at room temperature. Participants with amputation perceived warming as their skin temperature increased during exercise followed by the perception of cooling during rest, despite minimal associated decreases in skin temperature.

  2. Development of limb volume measuring system

    NASA Technical Reports Server (NTRS)

    Bhagat, P. K.; Kadaba, P. K.

    1983-01-01

    The mechanisms underlying the reductions in orthostatic tolerance associated with weightlessness are not well established. Contradictory results from measurements of leg volume changes suggest that altered venomotor tone and reduced blood flow may not be the only contributors to orthostatic intolerance. It is felt that a more accurate limb volume system which is insensitive to environmental factors will aid in better quantification of the hemodynamics of the leg. Of the varous limb volume techniques presently available, the ultrasonic limb volume system has proven to be the best choice. The system as described herein is free from environmental effects, safe, simple to operate and causes negligible radio frequency interference problems. The segmental ultrasonic ultrasonic plethysmograph is expected to provide a better measurement of limb volume change since it is based on cross-sectional area measurements.

  3. Ways Children Adjust to Limb Loss

    MedlinePlus

    ... March/April 2006 Original article by Douglas G. Smith, MD Translated into plain language by Helen Osborne ... Limb Deficiencies: Issues and Expectations,” by Douglas G. Smith, MD and Kellye Campbell, RN, ARNP published in ...

  4. CONGENITAL DEFORMITIES OF THE UPPER LIMBS.

    PubMed Central

    Bisneto, Edgard Novaes França

    2015-01-01

    This article, divided into three parts, had the aims of reviewing the most common upper-limb malformations and describing their treatments. In this first part, failure of formation is discussed. The bibliography follows after the first part. PMID:27047864

  5. Limb Loss in Children: Prosthetic Issues

    MedlinePlus

    ... adults with limb loss. Meeting a world-class swimmer, for instance, shows children that they can do ... they won’t ever be the world’s fastest swimmers, children can learn that there is greatness inside ...

  6. Skeletal muscle dedifferentiation during salamander limb regeneration.

    PubMed

    Wang, Heng; Simon, András

    2016-10-01

    Salamanders can regenerate entire limbs throughout their life. A critical step during limb regeneration is formation of a blastema, which gives rise to the new extremity. Salamander limb regeneration has historically been tightly linked to the term dedifferentiation, however, with refined research tools it is important to revisit the definition of dedifferentiation in the context. To what extent do differentiated cells revert their differentiated phenotypes? To what extent do progeny from differentiated cells cross lineage boundaries during regeneration? How do cell cycle plasticity and lineage plasticity relate to each other? What is the relationship between dedifferentiation of specialized cells and activation of tissue resident stem cells in terms of their contribution to the new limb? Here we highlight these problems through the case of skeletal muscle.

  7. Spatial Coupling Affects Both Homologous and Non-Homologous Limbs

    ERIC Educational Resources Information Center

    Huh, Carey Y.

    2004-01-01

    The present study examined the interaction between limb movements in space. The amount of interaction was measured by how much moving one limb affected the movement of another limb. Participants were 24 right-handed university students (19 female, mean AGE=19 years). The task was to draw lines with the right hand while moving another limb in lines…

  8. Isolated primary lymphedema tarda of the upper limb.

    PubMed

    Shariati, Farzaneh; Ravari, Hasan; Kazemzadeh, Gholamhossein; Sadeghi, Ramin

    2013-03-01

    Primary lymphedema tarda is considered as a congenital disease with late presentation. Primary lymphedema tarda usually affects lower limbs, and primary lymphedema tarda of the upper limbs usually accompanies lower limb lymphedema. In the current case report, we present an 80-year-old male patient with isolated left upper limb swelling that lymphoscintigraphy imaging proved to be lymphedema.

  9. PTSD in Limb Trauma and Recovery

    DTIC Science & Technology

    2008-10-16

    self-report and performance-based measures; 2) To test a new scoring system for the Prosthetic Evaluation Questionnaire (PEQ); 3) To determine if...13 “ANALYSIS OF GAIT MECHANICS OF AMPUTEES USING A NEW LOWER LIMB PROSTHESIS ” CONCLUSION...of the first lower limb prosthesis with a powered, biomimetic ankle. ANNUAL REPORT 9/17/2008 VIRTUAL REALITY AND MOTION ANALYSIS TO

  10. Biomechanical Properties of Insect Wings: The Stress Stiffening Effects on the Asymmetric Bending of the Allomyrina dichotoma Beetle's Hind Wing

    PubMed Central

    Ha, Ngoc San; Truong, Quang Tri; Goo, Nam Seo; Park, Hoon Cheol

    2013-01-01

    Although the asymmetry in the upward and downward bending of insect wings is well known, the structural origin of this asymmetry is not yet clearly understood. Some researchers have suggested that based on experimental results, the bending asymmetry of insect wings appears to be a consequence of the camber inherent in the wings. Although an experimental approach can reveal this phenomenon, another method is required to reveal the underlying theory behind the experimental results. The finite element method (FEM) is a powerful tool for evaluating experimental measurements and is useful for studying the bending asymmetry of insect wings. Therefore, in this study, the asymmetric bending of the Allomyrina dichotoma beetle's hind wing was investigated through FEM analyses rather than through an experimental approach. The results demonstrated that both the stressed stiffening of the membrane and the camber of the wing affect the bending asymmetry of insect wings. In particular, the chordwise camber increased the rigidity of the wing when a load was applied to the ventral side, while the spanwise camber increased the rigidity of the wing when a load was applied to the dorsal side. These results provide an appropriate explanation of the mechanical behavior of cambered insect wings, including the bending asymmetry behavior, and suggest an appropriate approach for analyzing the structural behavior of insect wings. PMID:24339878

  11. Biomechanical properties of insect wings: the stress stiffening effects on the asymmetric bending of the Allomyrina dichotoma beetle's hind wing.

    PubMed

    Ha, Ngoc San; Truong, Quang Tri; Goo, Nam Seo; Park, Hoon Cheol

    2013-01-01

    Although the asymmetry in the upward and downward bending of insect wings is well known, the structural origin of this asymmetry is not yet clearly understood. Some researchers have suggested that based on experimental results, the bending asymmetry of insect wings appears to be a consequence of the camber inherent in the wings. Although an experimental approach can reveal this phenomenon, another method is required to reveal the underlying theory behind the experimental results. The finite element method (FEM) is a powerful tool for evaluating experimental measurements and is useful for studying the bending asymmetry of insect wings. Therefore, in this study, the asymmetric bending of the Allomyrina dichotoma beetle's hind wing was investigated through FEM analyses rather than through an experimental approach. The results demonstrated that both the stressed stiffening of the membrane and the camber of the wing affect the bending asymmetry of insect wings. In particular, the chordwise camber increased the rigidity of the wing when a load was applied to the ventral side, while the spanwise camber increased the rigidity of the wing when a load was applied to the dorsal side. These results provide an appropriate explanation of the mechanical behavior of cambered insect wings, including the bending asymmetry behavior, and suggest an appropriate approach for analyzing the structural behavior of insect wings.

  12. Mathematical modeling of vertebrate limb development.

    PubMed

    Zhang, Yong-Tao; Alber, Mark S; Newman, Stuart A

    2013-05-01

    In this paper, we review the major mathematical and computational models of vertebrate limb development and their roles in accounting for different aspects of this process. The main aspects of limb development that have been modeled include outgrowth and shaping of the limb bud, establishment of molecular gradients within the bud, and formation of the skeleton. These processes occur interdependently during development, although (as described in this review), there are various interpretations of the biological relationships among them. A wide range of mathematical and computational methods have been used to study these processes, including ordinary and partial differential equation systems, cellular automata and discrete, stochastic models, finite difference methods, finite element methods, the immersed boundary method, and various combinations of the above. Multiscale mathematical modeling and associated computational simulation have become integrated into the study of limb morphogenesis and pattern formation to an extent with few parallels in the field of developmental biology. These methods have contributed to the design and analysis of experiments employing microsurgical and genetic manipulations, evaluation of hypotheses for limb bud outgrowth, interpretation of the effects of natural mutations, and the formulation of scenarios for the origination and evolution of the limb skeleton.

  13. Hyperbaric oxygenation accelerates prosthetic rehabilitation of lower limb amputees.

    PubMed

    Igor, Simanic; Mirko, Teofilovski; Dalibor, Paspalj; Milutin, Radotic; Dusica, Djordjevic; Vladimir, Zivkovic; Vladimir, Jakovljevic

    2013-01-01

    The purpose of the study was to assess the effects of hyperbaric oxygen (HBO2) therapy on prosthetic rehabilitation of patients with unilateral lower limb amputation. Narang's scale,the Locomotor Capabilities Index and the two-minute walk test were used to assess functional abilities of amputees on the admission and on discharge from hospital. We also kept records of some clinical parameters whose improvement enables better mobility of patients: thigh and lower leg girth, strength of amputation stump, existence of amputation stump contracture, existence of some other complications on amputation stump, blood oxygenation and pulse palpation. Our results show that hyperbaric oxygenation accelerates prosthetic rehabilitation of lower limb amputees. HBO2-treated patients were discharged from the hospital faster than the controls (hospitalized for 133.2 +/- 54.87 days vs. 158.36 +/- 53.05 days), they had improved arterial Hb saturation (97.40 +/- 3.51% vs. 94.74 +/- 3.28 %) and pulse palpability (pulse palpable in 27 vs. 18 subjects), less complications of the amputation stump (complications present in 24 vs. 30 subjects), greater healthy leg thigh girth (50.75 +/- 3.96 cm vs. 48.90 +/- 2.59 cm), stronger amputation stump (mark 3.90 +/- 0.54 vs. 3.33 +/- 0.47) and better functional abilities as measured by adapted Narang's scale (category 3.43 +/- 1.30 vs. 4.10 +/- 1.12) and locomotor capabilities index (score 38.06 +/- 10.90 vs. 33.16 +/- 8.80). These findings highlight the increasing validity of this procedure after limb amputation, which should be confirmed by further research in multicenter studies involving a larger number of respondents.

  14. Regenerative Engineering and Bionic Limbs

    PubMed Central

    James, Roshan; Laurencin, Cato T.

    2015-01-01

    Amputations of the upper extremity are severely debilitating, current treatments support very basic limb movement, and patients undergo extensive physiotherapy and psychological counselling. There is no prosthesis that allows the amputees near-normal function. With increasing number of amputees due to injuries sustained in accidents, natural calamities and international conflicts, there is a growing requirement for novel strategies and new discoveries. Advances have been made in technological, material and in prosthesis integration where researchers are now exploring artificial prosthesis that integrate with the residual tissues and function based on signal impulses received from the residual nerves. Efforts are focused on challenging experts in different disciplines to integrate ideas and technologies to allow for the regeneration of injured tissues, recording on tissue signals and feed-back to facilitate responsive movements and gradations of muscle force. A fully functional replacement and regenerative or integrated prosthesis will rely on interface of biological process with robotic systems to allow individual control of movement such as at the elbow, forearm, digits and thumb in the upper extremity. Regenerative engineering focused on the regeneration of complex tissue and organ systems will be realized by the cross-fertilization of advances over the past thirty years in the fields of tissue engineering, nanotechnology, stem cell science, and developmental biology. The convergence of toolboxes crated within each discipline will allow interdisciplinary teams from engineering, science, and medicine to realize new strategies, mergers of disparate technologies, such as biophysics, smart bionics, and the healing power of the mind. Tackling the clinical challenges, interfacing the biological process with bionic technologies, engineering biological control of the electronic systems, and feed-back will be the important goals in regenerative engineering over the next

  15. DEMONSTRATION OF SORBENT INJECTION TECHNOLOGY ON A WALL-FIRED UTILITY BOILER (EDGEWATER LIMB DEMONSTRATION)

    EPA Science Inventory

    The report gives results of the full-scale demonstration of Limestone Injection Multistage Burner (LIMB) technology on the coal-fired, 105 MW, Unit 4 boiler at Ohio Edison's Edgewater Station. eveloped as a technology aimed at moderate levels of sulfur dioxide (SO2) and nitrogen ...

  16. Cross-sectional study of alteration of phantom limb pain with visceral stimulation in military personnel with amputation.

    PubMed

    Rafferty, Michael; Bennett Britton, Thomas M; Drew, Benjamin T; Phillip, Rhodri D

    2015-01-01

    While phantom limb pain is a well-recognized phenomenon, clinical experience has suggested that the augmentation of phantom limb pain with visceral stimulation is an issue for many military personnel with amputation (visceral stimulation being the sensation of the bowel or bladder either filling or evacuating). However, the prevalence of this phenomenon is not known. The aim of this study was to investigate the prevalence of the alteration in phantom limb pain and the effect that visceral stimulation has on phantom limb pain intensity. A cross-sectional study of 75 military personnel who have lost one or both lower limbs completed a questionnaire to assess the prevalence of the alteration of phantom limb pain with visceral stimulation. Included in the questionnaire was a pain visual analog scale (VAS) graded from 0 to 10. Patients recorded the presence and intensity of phantom limb pain. They also recorded whether and how this pain altered with a need to micturate or micturition, and/or a need to defecate or defecation, again using a pain VAS. Time since amputation, level of amputation, and medications were also recorded. Patients reported a phantom limb pain prevalence of 85% with a mean VAS of 3.6. In all, 56% of patients reported a change in the severity of phantom limb pain with visceral stimuli. The mean increase in VAS for visceral stimulation was 2.5 +/- 1.6 for bladder stimulation and 2.9 +/- 2.0 for bowel stimulation. Of the patients questioned, 65% reported an improvement in symptoms over time. VAS scores were highest in the subgroup less than 6 mo postamputation. An increase in phantom limb pain with visceral stimulation is a common problem for military personnel with amputation.

  17. Reproductive performance of pubertal red deer (Cervus elaphus) hinds: effects of genetic introgression of wapiti subspecies on pregnancy rates at 18 months of age.

    PubMed

    Asher, G W; Archer, J A; Scott, I C; O'Neill, K T; Ward, J; Littlejohn, R P

    2005-12-01

    Low reproductive productivity of young red deer (Cervus elaphus) hinds on New Zealand deer farms appears to reflect high incidences of puberty failure at 16 months of age. This is despite the general attainment of average liveweights 15-25 kg in excess of the accepted minimum threshold for puberty in subspecies of western European origin (scoticus, elaphus and hippelaphus) that form the basis of the national herd. The present study tests the hypotheses that introgression of the larger North American wapiti subspecies (nelsoni, manitobensis and roosevelti) into breeding herds (1) can be assessed from morphological features of individuals, (2) that there is a relationship between the level of wapiti parentage and non-pregnancy rate at 18 months of age (a proxy for puberty failure) and (3) that minimum liveweight thresholds for puberty increase with increasing levels of wapiti parentage. A total of 4329 18-month-old hinds across four "red" deer farms in southern New Zealand were scanned for pregnancy status. Each hind was assigned a wapiti score (WS) as a subjective assessment of the obviousness of wapiti features. Various body measurements were additionally recorded for each hind. A hair sample was collected for DNA analysis (14 markers) to objectively assign subspecies pedigree (i.e. "Elkmeter") on a subset of 1258 individuals. A total of 506 (11.7%) hinds were not pregnant at 18 months of age with rates varying between 4.1 and 37.3% between farms and years. Mean WS differed significantly between farms and reflected the genetic management policy of each farm. WS was positively correlated to Elkmeter for each farm/year (<0.05) although regression slopes varied significantly. WS was able to be adjusted for these differences to assign a corrected WS (CWS) for all 4329 individuals that estimated the proportion wapiti parentage. Discriminant analysis of morphological variables relative to Elkmeter supported the first hypothesis and showed that shoulder height and body

  18. Control of Dynamic Limb Motion Using Fatigue-Resistant Asynchronous Intrafascicular Multi-Electrode Stimulation

    PubMed Central

    Frankel, Mitchell A.; Mathews, V John; Clark, Gregory A.; Normann, Richard A.; Meek, Sanford G.

    2016-01-01

    Asynchronous intrafascicular multi-electrode stimulation (aIFMS) of small independent populations of peripheral nerve motor axons can evoke selective, fatigue-resistant muscle forces. We previously developed a real-time proportional closed-loop control method for aIFMS generation of isometric muscle force and the present work extends and adapts this closed-loop controller to the more demanding task of dynamically controlling joint position in the presence of opposing joint torque. A proportional-integral-velocity controller, with integrator anti-windup strategies, was experimentally validated as a means to evoke motion about the hind-limb ankle joint of an anesthetized feline via aIFMS stimulation of fast-twitch plantar-flexor muscles. The controller was successful in evoking steps in joint position with 2.4% overshoot, 2.3-s rise time, 4.5-s settling time, and near-zero steady-state error. Controlled step responses were consistent across changes in step size, stable against external disturbances, and reliable over time. The controller was able to evoke smooth eccentric motion at joint velocities up to 8 deg./s, as well as sinusoidal trajectories with frequencies up to 0.1 Hz, with time delays less than 1.5 s. These experiments provide important insights toward creating a robust closed-loop aIFMS controller that can evoke precise fatigue-resistant motion in paralyzed individuals, despite the complexities introduced by aIFMS. PMID:27679557

  19. IGF-1 and Chondroitinase ABC Augment Nerve Regeneration after Vascularized Composite Limb Allotransplantation

    PubMed Central

    Kostereva, Nataliya V.; Wang, Yong; Fletcher, Derek R.; Unadkat, Jignesh V.; Schnider, Jonas T.; Komatsu, Chiaki; Yang, Yang; Stolz, Donna B.; Davis, Michael R.; Plock, Jan A.; Gorantla, Vijay S.

    2016-01-01

    Impaired nerve regeneration and inadequate recovery of motor and sensory function following peripheral nerve repair remain the most significant hurdles to optimal functional and quality of life outcomes in vascularized tissue allotransplantation (VCA). Neurotherapeutics such as Insulin-like Growth Factor-1 (IGF-1) and chondroitinase ABC (CH) have shown promise in augmenting or accelerating nerve regeneration in experimental models and may have potential in VCA. The aim of this study was to evaluate the efficacy of low dose IGF-1, CH or their combination (IGF-1+CH) on nerve regeneration following VCA. We used an allogeneic rat hind limb VCA model maintained on low-dose FK506 (tacrolimus) therapy to prevent rejection. Experimental animals received neurotherapeutics administered intra-operatively as multiple intraneural injections. The IGF-1 and IGF-1+CH groups received daily IGF-1 (intramuscular and intraneural injections). Histomorphometry and immunohistochemistry were used to evaluate outcomes at five weeks. Overall, compared to controls, all experimental groups showed improvements in nerve and muscle (gastrocnemius) histomorphometry. The IGF-1 group demonstrated superior distal regeneration as confirmed by Schwann cell (SC) immunohistochemistry as well as some degree of extrafascicular regeneration. IGF-1 and CH effectively promote nerve regeneration after VCA as confirmed by histomorphometric and immunohistochemical outcomes. PMID:27272754

  20. Post-hatching growth and development of the pectoral and pelvic limbs in the black noddy, Anous minutus.

    PubMed

    Bennett, Michael B

    2008-06-01

    The black tern (Anous minutus) uses a semi-precocial growth strategy. Terrestrial locomotor capacity occurs soon after hatching, but pectoral limb development is delayed and flight is not possible until about post-hatching day 50. A growth series (hatchlings to fledglings) was used to explore how limb musculoskeletal development varied with body mass. In the pelvic limb, bone lengths scaled isometrically or with negative allometry. Gastrocnemius muscle mass and the failure load and stiffness of the tibiotarsus scaled isometrically. In the pectoral limb, pectoralis and supracoracoideus muscle masses increased with strong positive allometry that was mirrored by increases in wing bone strength and stiffness. Bending strength (sigma(ult)) and modulus (E) remained fairly constant throughout development to fledging for all limb bones. The moment of inertia (I) scaled with negative allometry for the tibiotarsus and with strong positive allometry in the wing bones. Differences in sigma(ult) and E of the tibiotarsus between pre-fledged chicks and adults was due, primarily, to increases in bone density rather than increases in the moment of inertia of the skeletal elements, whereas sigma(ult) of wing bones was a function of increases in both bone density and I. Early development of functional pelvic limbs in tree-nesting birds is relatively unusual, and presumably reflects a familial trait that does not appear to compromise breeding success in this species.

  1. Comparative architectural properties of limb muscles in Crocodylidae and Alligatoridae and their relevance to divergent use of asymmetrical gaits in extant Crocodylia

    PubMed Central

    Allen, Vivian; Molnar, Julia; Parker, William; Pollard, Andrea; Nolan, Grant; Hutchinson, John R

    2014-01-01

    Crocodiles and their kin (Crocodylidae) use asymmetrical (bounding and galloping) gaits when moving rapidly. Despite being morphologically and ecologically similar, it seems alligators and their kin (Alligatoridae) do not. To investigate a possible anatomical basis for this apparent major difference in locomotor capabilities, we measured relative masses and internal architecture (fascicle lengths and physiological cross-sectional areas) of muscles of the pectoral and pelvic limbs of 40 individuals from six representative species of Crocodylidae and Alligatoridae. We found that, relative to body mass, Crocodylidae have significantly longer muscle fascicles (increased working range), particularly in the pectoral limb, and generally smaller muscle physiological cross-sectional areas (decreased force-exerting capability) than Alligatoridae. We therefore hypothesise that the ability of some crocodylians to use asymmetrical gaits may be limited more by the ability to make large, rapid limb motions (especially in the pectoral limb) than the ability to exert large limb forces. Furthermore, analysis of scaling patterns in muscle properties shows that limb anatomy in the two clades becomes more divergent during ontogeny. Limb muscle masses, fascicle lengths and physiological cross-sectional areas scale with significantly larger coefficients in Crocodylidae than Alligatoridae. This combination of factors suggests that inter-clade disparity in maximal limb power is highest in adult animals. Therefore, despite their apparent morphological similarities, both mean values and scaling patterns suggest that considerable diversity exists in the locomotor apparatus of extant Crocodylia. PMID:25418112

  2. Dissociated lower limb muscle involvement in amyotrophic lateral sclerosis.

    PubMed

    Simon, Neil G; Lee, Michael; Bae, Jong Seok; Mioshi, Eneida; Lin, Cindy S-Y; Pfluger, Casey M; Henderson, Robert D; Vucic, Steve; Swash, Michael; Burke, David; Kiernan, Matthew C

    2015-06-01

    It has been suggested that corticomotoneuronal drive to ankle dorsiflexors is greater than to ankle plantar flexor muscles, despite the finding that plantar flexors are no less active than TA during walking and standing. The present study was undertaken to determine whether there was differential involvement of distal lower limb muscles in amyotrophic lateral sclerosis (ALS), to elucidate pathophysiological mechanisms of selective muscle involvement. Prospective studies were undertaken in 52 ALS patients, including clinical assessment, disease staging (revised ALS functional rating scale), Medical Research Council sum score, and a scale of upper motor neurone (UMN) dysfunction. Motor unit number estimates (MUNE) and compound muscle action potentials (CMAP) from ankle dorsiflexors and plantar flexors were used to provide objective measures. A novel 'split leg index' was calculated as follows: SLI = CMAPDF ÷ CMAPPF. In ALS, there was significantly greater reduction of MUNE and CMAP amplitude recorded from plantar flexors when compared to dorsiflexors, suggesting preferential involvement of plantar flexor muscles, underpinning a 'split leg' appearance. The SLI correlated with clinical plantar flexor strength (R= -0.56, p < 0.001). In no patient did the SLI suggest preferential dorsiflexor involvement. In subgroup analyses, mean SLI was greatest in lower limb-onset ALS. In conclusion, the present study has established dissociated involvement of muscles acting around the ankle in ALS. We suggest this reflects underlying differences in cortical, descending or local spinal modulation of these muscles.

  3. Detection of hemophilia a carriers in Azeri Turkish population of Iran: usefulness of HindIII and BclI markers.

    PubMed

    Moharrami, Tamouchin; Derakhshan, Sima Mansoori; Pourfeizi, Abbas Ali H; Khaniani, Mahmoud Shekari

    2015-11-01

    Hemophilia A (HA) is an inherited X-linked coagulation disorder caused by the deficiency of factor VIII (FVIII). Linkage analysis is a common indirect method for the detection of female carriers in families with HA. In the current study, 173 patients from 30 unrelated families with HA were recruited from the Azeri Turkish population of northwest Iran and analyzed for BclI and HindIII markers by polymerase chain reaction-restriction fragment length polymorphism. We investigated the potential of using these markers for the detection of mutation in carriers through linkage analysis, which would be of tremendous use in prenatal diagnosis. Among the tested women, 47% and 35% were found to be heterozygous for BclI and HindIII polymorphic markers, respectively. The BclI and HindIII markers were informative for the detection of 63% and 17% potential carriers, respectively, demonstrating the effectiveness of the BclI marker for the detection of HA carriers among the Azeri Turkish population.

  4. Dietary fat content and fiber type modulate hind gut microbial community and metabolic markers in the pig.

    PubMed

    Yan, Hui; Potu, Ramesh; Lu, Hang; Vezzoni de Almeida, Vivian; Stewart, Terry; Ragland, Darryl; Armstrong, Arthur; Adeola, Olayiwola; Nakatsu, Cindy H; Ajuwon, Kolapo M

    2013-01-01

    Obesity leads to changes in the gut microbial community which contribute to the metabolic dysregulation in obesity. Dietary fat and fiber affect the caloric density of foods. The impact of dietary fat content and fiber type on the microbial community in the hind gut is unknown. Effect of dietary fat level and fiber type on hindgut microbiota and volatile fatty acid (VFA) profiles was investigated. Expression of metabolic marker genes in the gut, adipose tissue and liver was determined. A 2 × 2 experiment was conducted in pigs fed at two dietary fat levels (5% or 17.5% swine grease) and two fiber types (4% inulin, fermentable fructo-oligosaccharide or 4% solka floc, non-fermentable cellulose). High fat diets (HFD) resulted in a higher (P<0.05) total body weight gain, feed efficiency and back fat accumulation than the low fat diet. Feeding of inulin, but not solka floc, attenuated (P<0.05) the HFD-induced higher body weight gain and fat mass accumulation. Inulin feeding tended to lead to higher total VFA production in the cecum and resulted in a higher (P<0.05) expression of acyl coA oxidase (ACO), a marker of peroxisomal β-oxidation. Inulin feeding also resulted in lower expression of sterol regulatory element binding protein 1c (SREBP-1c), a marker of lipid anabolism. Bacteria community structure characterized by DGGE analysis of PCR amplified 16S rRNA gene fragments showed that inulin feeding resulted in greater bacterial population richness than solka floc feeding. Cluster analysis of pairwise Dice similarity comparisons of the DGGE profiles showed grouping by fiber type but not the level of dietary fat. Canonical correspondence analysis (CCA) of PCR- DGGE profiles showed that inulin feeding negatively correlated with back fat thickness. This study suggests a strong interplay between dietary fat level and fiber type in determining susceptibility to obesity.

  5. [Exercise training in chronic obstructive pulmonary disease. Comparative study of aerobic training of lower limbs vs. combination with upper limbs].

    PubMed

    Sívori, M; Rhodius, E; Kaplan, P; Talarico, M; Gorojod, G; Carreras, B; López, C; Shimojo, C

    1998-01-01

    A prospective, randomized and controlled study has been performed in 28 patients with severe COPD. A group of 14 has been trained with their lower limbs (LL), while another similar group of 14 patients was also trained with their upper limbs (UL). Results showed improvement in both groups in the endurance test for LL, dyspnea scale, efficiency and muscular working capacity. A considerable improvement was observed in the oxygen uptake at the anerobic threshold (VO2AT) which suggests a training effect, expressed through an improvement in exercise tolerance. Only the group who trained UL showed a remarkable improvement in the dyspnea scale, endurance test and maximal static mouth pressure, showing a better intrinsic working capacity and participation of the UL muscles producing those manoeuvres. At the end of training, quality of life was significantly increased and the hospitalization rate was lower in both groups. According to these findings, it is suggested that patients with severe COPD included in training programmes add UL exercises to the LL usually carried out.

  6. Running With an Elastic Lower Limb Exoskeleton.

    PubMed

    Cherry, Michael S; Kota, Sridhar; Young, Aaron; Ferris, Daniel P

    2016-06-01

    Although there have been many lower limb robotic exoskeletons that have been tested for human walking, few devices have been tested for assisting running. It is possible that a pseudo-passive elastic exoskeleton could benefit human running without the addition of electrical motors due to the spring-like behavior of the human leg. We developed an elastic lower limb exoskeleton that added stiffness in parallel with the entire lower limb. Six healthy, young subjects ran on a treadmill at 2.3 m/s with and without the exoskeleton. Although the exoskeleton was designed to provide ~50% of normal leg stiffness during running, it only provided 24% of leg stiffness during testing. The difference in added leg stiffness was primarily due to soft tissue compression and harness compliance decreasing exoskeleton displacement during stance. As a result, the exoskeleton only supported about 7% of the peak vertical ground reaction force. There was a significant increase in metabolic cost when running with the exoskeleton compared with running without the exoskeleton (ANOVA, P < .01). We conclude that 2 major roadblocks to designing successful lower limb robotic exoskeletons for human running are human-machine interface compliance and the extra lower limb inertia from the exoskeleton.

  7. Neck muscle fatigue alters upper limb proprioception.

    PubMed

    Zabihhosseinian, Mahboobeh; Holmes, Michael W R; Murphy, Bernadette

    2015-05-01

    Limb proprioception is an awareness by the central nervous system (CNS) of the location of a limb in three-dimensional space and is essential for movement and postural control. The CNS uses the position of the head and neck when interpreting the position of the upper limb, and altered input from neck muscles may affect the sensory inputs to the CNS and consequently may impair the awareness of upper limb joint position. The purpose of this study was to determine whether fatigue of the cervical extensors muscles (CEM) using a submaximal fatigue protocol alters the ability to recreate a previously presented elbow angle with the head in a neutral position. Twelve healthy individuals participated. CEM activity was examined bilaterally using surface electromyography, and kinematics of the elbow joint was measured. The fatigue protocol included an isometric neck extension task at 70 % of maximum until failure. Joint position error increased following fatigue, demonstrating a significant main effect of time (F 2, 18 = 19.41, p ≤ 0.0001) for absolute error. No significant differences were found for variable error (F 2, 18 = 0.27, p = 0.76) or constant error (F 2, 18 = 1.16 of time, p ≤ 0.33). This study confirms that fatigue of the CEM can reduce the accuracy of elbow joint position matching. This suggests that altered afferent input from the neck subsequent to fatigue may impair upper limb proprioception.

  8. Amputation versus functional reconstruction in the management of complex hind foot injuries caused by land-mine explosions: a long-term retrospective comparison.

    PubMed

    Demiralp, Bahtiyar; Ege, Tolga; Kose, Ozkan; Yurttas, Yuksel; Basbozkurt, Mustafa

    2014-05-01

    The purpose of this study is to compare the long-term clinical outcomes of patients who were treated with either hind foot reconstruction or amputation in complex hind foot injuries accompanied with bone and soft tissue loss due to land-mine explosions. Between 1994 and 2004, all patients with hind foot complex injuries due to land-mine explosion, who were operated in our clinic, were enrolled to the study. All patients were evaluated with Short-Form 36 (SF-36), Foot and Ankle Disability Index (FADI) and Body Image Quality of Life Inventory (BIQLI) after a mean of 15.1 ± 2.2 (range 9-19) years of follow-up. Demographic characteristics, number of operations, necessity of psychiatric treatment and all complications were compared between groups. There were a total of 42 patients [21 in reconstruction group (Gr I) and 21 in amputation group (Gr II)]. The mean age at the time of final follow-up was 38.4 ± 3.04 years in Gr I and 38.2 ± 4.24 years in Gr II (p = 0.732). The mean follow-up duration was 15.7 ± 2.07 years in Gr I and 14.57 ± 2.29 years in Gr II (p = 0.081). The number of operations was significantly higher in Gr I (8.66 ± 10.2 times vs. 4.42 ± 7.7 times, respectively, p = 0.001). The mean FADI score at the final follow-up was 64.3 ± 18.1 in Gr I. In amputation group, more patients needed psychotherapy due to major depression (12 patients vs. 4 patients, p = 0.012). Major complications in Gr I were musculocutaneous flap atrophy in calcaneal region (n = 8 patients), limited ankle motion (n = 11) and painful osteophytes on plantar region (n = 6). In Gr II, stump problems were dominating (pain and tenderness n = 10, ulcer n = 2, allergic skin lesions n = 7, painful neuroma n = 10, bony spur n = 5, paresthesia n = 1, excessive sweating n = 12). At the final visit, although SF-36 scores were similar between groups (p = 0.182), extremity reconstruction group had significantly higher BIQLI scores than the amputation group (p = 0.016). If the dorsalis pedis is

  9. Goniometry and Limb Girth in Miniature Dachshunds

    PubMed Central

    Thomovsky, Stephanie A.; Chen, Annie V.; Kiszonas, Alecia M.; Lutskas, Lori A.

    2016-01-01

    Purpose. To report the mean and median pelvic limb joint angles and girth measurements in miniature Dachshunds presenting with varying degrees of pelvic limb weakness secondary to thoracolumbar intervertebral disc extrusion. Methods. 15 miniature Dachshunds who presented to WSU-VTH for thoracolumbar disc extrusion. Dachshunds varied in neurologic status from ambulatory paraparetic to paraplegic at the time of measurements. Results. There were no significant differences in joint angles or girth among the three groups (ambulatory paraparetic, nonambulatory paraparetic, or paraplegic) (P > 0.05). When group was disregarded and values for extension, flexion, and girth combined, no differences existed. Conclusions. Goniometry and limb girth measurements can successfully be made in the miniature Dachshund; however, the shape of the Dachshund leg makes obtaining these values challenging. There were no differences in joint angle or girth measurements between dogs with varying neurologic dysfunction at the time of measurement. PMID:27403455

  10. Endovascular management of acute limb ischemia.

    PubMed

    Peeters, P; Verbist, J; Keirse, K; Deloose, K; Bosiers, M

    2010-06-01

    Acute limb ischemia (ALI) refers to a rapid worsening of limb perfusion resulting in rest pain, ischemic ulcers or gangrene. With an estimated incidence of 140 million/year, ALI is serious limb-threatening and life-threatening medical emergency demanding prompt action. Three prospective, randomized clinical trials provide data on trombolytic therapy versus surgical intervention in patients with acute lower extremity ischemia. Although they did not give us the final answer, satisfactory results are reported for percutaneous thrombolysis compared with surgery. Moreover, they suggest an important advantage of thrombolysis in acute bypass graft occlusions. Therefore, we believe thrombolytic therapy should be a part of the vascular surgeon's armamentarium to safely and successfully treat ALI patients.

  11. The Special Sensor Ultraviolet Limb Imager instruments

    NASA Astrophysics Data System (ADS)

    Dymond, K. F.; Nicholas, A. C.; Budzien, S. A.; Coker, C.; Stephan, A. W.; Chua, D. H.

    2017-02-01

    The Special Sensor Ultraviolet Limb Imager (SSULI) instruments are ultraviolet limb scanning sensors flying on the United States Air Force Defense Meteorological Satellite Program Block 5D-3 satellites. The SSULIs cover the 800-1700 Å wavelength range at 18 Å spectral resolution. This wavelength range contains spectral signatures of all the dominant neutral and ionized species in the thermosphere and F region ionosphere. The instruments view ahead of the spacecraft and operate as limb imagers covering the 100-750 km altitude range at 10-15 km resolution with a 90 s scan cadence. We describe these instruments and summarize their calibration and on-orbit performance. Day-to-day variability of the nighttime ionosphere at low latitudes and longer-term variability of the global mean exospheric temperature are highlighted.

  12. Gradients of signalling in the developing limb.

    PubMed

    Towers, Matthew; Wolpert, Lewis; Tickle, Cheryll

    2012-04-01

    The developing limb is one of the first systems where it was proposed that a signalling gradient is involved in pattern formation. This gradient for specifying positional information across the antero-posterior axis is based on Sonic hedgehog signalling from the polarizing region. Recent evidence suggests that Sonic hedgehog signalling also specifies positional information across the antero-posterior axis by a timing mechanism acting in parallel with graded signalling. The progress zone model for specifying proximo-distal pattern, involving timing to provide cells with positional information, continues to be challenged, and there is further evidence that graded signalling by retinoic acid specifies the proximal part of the limb. Other recent papers present the first evidence that gradients of signalling by Wnt5a and FGFs govern cell behaviour involved in outgrowth and morphogenesis of the developing limb.

  13. The Lower Limb Functional Index - A reliable and valid functional outcome assessment in burns.

    PubMed

    Gittings, Paul M; Heberlien, Nicholas; Devenish, Neale; Parker, Matthew; Phillips, Michael; Wood, Fiona M; Edgar, Dale W

    2016-09-01

    Lower limb injuries account for up to 40% of all burns in Western Australia and affect physical function. Lower limb specific functional assessments are available to monitor recovery, yet no scale has been assessed for use in burns. The Lower Limb Functional Index (LLFI) which is validated in musculoskeletal patients was investigated for applicability in burn. Reliability was assessed using Cronbach's alpha, principal components analysis and Rasch analysis. Validity was assessed using Spearman's correlation coefficient with quality of life assessments (BSHS-B & SF-36) and physical assessments (TUG & ankle ROM). Regression analysis was performed with burn severity measures, time of recovery and location of the burn. The LLFI-10 was applied 1368 times on 739 patients at regular time points. It was internally consistent (α>0.8) and unidimensional. Associations were demonstrated with the BSHS-B and SF-36 (rho=-0.56 to -0.72, p<0.001), TUG (rho=0.41, p<0.001) and ankle ROM (rho=-0.31 to -0.35, p<0.001). The LLFI-10 also showed associations (p<0.001) with time since injury (rho=-0.29), age (rho=0.12) and TBSA (rho=0.12). The LLFI-10 is a reliable and valid tool to assess function in lower limb burns. This study supports the use of the LLFI-10 as part of a battery of assessment for lower limb burn recovery.

  14. A Pilot Study of Botulinum Toxin for Jerky, Position-Specific, Upper Limb Action Tremor

    PubMed Central

    Saifee, Tabish A.; Teodoro, Tiago; Erro, Roberto; Edwards, Mark J.; Cordivari, Carla

    2016-01-01

    Background We aimed to investigate the efficacy and safety of botulinum toxin (BT) injections for jerky action tremor of the upper limb. Methods We performed an uncontrolled, prospective study of electromyography (EMG)-guided BT injections for jerky, position-specific, upper limb action tremor. The primary outcome was clinical global impression at 3–6 weeks after baseline. Results Eight patients with jerky, position-specific action tremor involving the upper limb were consecutively recruited. After a median follow-up of 4.4 weeks (interquartile range [IQR] 3.6–6 weeks), four of them rated themselves as “improved” and two as “much improved.” Five of these six subjects reported improvements in specific activities of daily living (bringing liquids to mouth, feeding, shaving, and dressing). Upper limb subscore of the Fahn–Tolosa–Marin Tremor Rating Scale (FTM) significantly decreased from 4.5 (4–6) to 3 (2–5) (p = 0.01). Discussion This pilot, prospective cohort study suggests that EMG-guided BT injections may improve jerky, position-specific, upper limb action tremor. Placebo-controlled studies evaluating larger samples of patients are warranted to confirm these findings. PMID:27818844

  15. Special Considerations for Multiple Limb Amputation.

    PubMed

    Pasquina, Paul F; Miller, Matthew; Carvalho, A J; Corcoran, Michael; Vandersea, James; Johnson, Elizabeth; Chen, Yin-Ting

    2014-01-01

    It has been estimated that more than 1.6 million individuals in the United States have undergone at least one amputation. The literature abounds with research of the classifications of such injuries, their etiologies, epidemiologies, treatment regimens, average age of onset (average age of amputation), and much more. The subpopulation that is often overlooked in these evaluations, however, is comprised of individuals who have suffered multiple limb loss. The challenges faced by those with single-limb loss are amplified for those with multiple limb loss. Pain, lifestyle adjustment, and quality of life return are just a few key areas of concern in this population. Along with amputations resulting from trauma, many individuals with multiple amputations have endured them as a result of dysvascular disease. Over recent years, amputations as a result of dysvascular disease have risen to comprise more than 80 % of new amputations occurring in the United States every year. This compares to just 54 % of total current prevalence. Those with diabetes comorbid with dysvascular disease make up 74 % of those with dysvascular amputations, and these individuals with diabetes comorbid with dysvascular disease have a 55 % chance of enduring an amputation of their contralateral limb within 2-3 years of their initial amputation. With the well-documented aging of the nation's population and the similarly skyrocketing prevalence of dysvascular disease and diabetes, it can be expected that the number of individuals with multiple limb loss will continue to increase in the United States. This article outlines the recommended measures of care for this particular subpopulation, including pain management, behavioral health considerations, strategies for rehabilitation for various levels and variations of multiple limb loss, and the assistive technology and adaptive equipment that might be available for these individuals to best enable them to continue healthy, fulfilling lives following

  16. Sonic hedgehog: restricted expression and limb dysmorphologies.

    PubMed

    Hill, Robert E; Heaney, Simon J H; Lettice, Laura A

    2003-01-01

    Sonic hedgehog, SHH, is required for patterning the limb. The array of skeletal elements that compose the hands and feet, and the ordered arrangement of these bones to form the pattern of fingers and toes are dependent on SHH. The mechanism of action of SHH in the limb is not fully understood; however, an aspect that appears to be important is the localized, asymmetric expression of Shh. Shh is expressed in the posterior margin of the limb bud in a region defined as the zone of polarizing activity (ZPA). Analysis of mouse mutants which have polydactyly (extra toes) shows that asymmetric expression of Shh is lost due to the appearance of an ectopic domain of expression in the anterior limb margin. One such polydactylous mouse mutant, sasquatch (Ssq), maps to the corresponding chromosomal region of the human condition pre-axial polydactyly (PPD) and thus represents a model for this condition. The mutation responsible for Ssq is located 1 Mb away from the Shh gene; however, the mutation disrupts a long-range cis-acting regulator of Shh expression. By inference, human pre-axial polydactyly results from a similar disruption of Shh expression. Other human congenital abnormalities also map near the pre-axial polydactyly locus, suggesting a major chromosomal region for limb dysmorphologies. The distinct phenotypes range from loss of all bones of the hands and feet to syndactyly of the soft tissue and fusion of the digits. We discuss the role played by Shh expression in mouse mutant phenotypes and the human limb dysmorphologies.

  17. Sonic hedgehog: restricted expression and limb dysmorphologies

    PubMed Central

    Hill, Robert E; Heaney, Simon JH; Lettice, Laura A

    2003-01-01

    Sonic hedgehog, SHH, is required for patterning the limb. The array of skeletal elements that compose the hands and feet, and the ordered arrangement of these bones to form the pattern of fingers and toes are dependent on SHH. The mechanism of action of SHH in the limb is not fully understood; however, an aspect that appears to be important is the localized, asymmetric expression of Shh. Shh is expressed in the posterior margin of the limb bud in a region defined as the zone of polarizing activity (ZPA). Analysis of mouse mutants which have polydactyly (extra toes) shows that asymmetric expression of Shh is lost due to the appearance of an ectopic domain of expression in the anterior limb margin. One such polydactylous mouse mutant, sasquatch (Ssq), maps to the corresponding chromosomal region of the human condition pre-axial polydactyly (PPD) and thus represents a model for this condition. The mutation responsible for Ssq is located 1 Mb away from the Shh gene; however, the mutation disrupts a long-range cis-acting regulator of Shh expression. By inference, human pre-axial polydactyly results from a similar disruption of Shh expression. Other human congenital abnormalities also map near the pre-axial polydactyly locus, suggesting a major chromosomal region for limb dysmorphologies. The distinct phenotypes range from loss of all bones of the hands and feet to syndactyly of the soft tissue and fusion of the digits. We discuss the role played by Shh expression in mouse mutant phenotypes and the human limb dysmorphologies. PMID:12587915

  18. Creation of distal canine limb lymphedema

    SciTech Connect

    Chen, H.C.; Pribaz, J.J.; O'Brien, B.M.; Knight, K.R.; Morrison, W.A.

    1989-06-01

    A canine model of distal limb lymphedema was established in order to study the treatment of this condition by lymph node transfer. This model was more difficult to establish than whole-limb lymphedema. Significant edema was achieved by a combination of preoperative irradiation and circumferential removal of skin from the irradiated areas followed by removal of the contents of the popliteal fossa. Despite these measures, it was not possible to produce lymphedema in every case, possibly because of the presence of lymphaticovenous shunts and panvascular compensation mechanisms.

  19. Syndecan-3 in limb skeletal development.

    PubMed

    Kosher, R A

    1998-10-15

    Syndecan-3 is a member of a family of heparan sulfate proteoglycans that function as extracellular matrix receptors and as co-receptors for growth factors and signalling molecules. A variety of studies indicate that syndecan-3 is involved in several aspects of limb morphogenesis and skeletal development. Syndecan-3 participates in limb outgrowth and proliferation in response to the apical ectodermal ridge; mediates cell-matrix and/or cell-cell interactions involved in regulating the onset of chondrogenesis; may be involved in regulating the onset of osteogenesis and joint formation and, plays a role in regulating the proliferation of epiphyseal chondrocytes during endochondral ossification.

  20. Solar limb brightening at 350 microns

    SciTech Connect

    Lindsey, C.; Hildebrand, R.H.; Keene, J.; Whitcomb, S.E.

    1981-09-01

    We have used the NASA Infrared Telescope Facility at Mauna Kea to observe the intensity profile of the quiet solar limb in the 300--400 ..mu..m continuum. We find a significant resolved brightening of several percent over the outer 60'' of the solar limb in this band. However, the magnitude of the brightening is considerably less than that indicated by earlier observations of a total solar eclipse in integrated Sun--Moon radiation by Beckman, Lesurf, and Ross in the 1.2 mm continuum.

  1. Deciphering skeletal patterning: clues from the limb.

    PubMed

    Mariani, Francesca V; Martin, Gail R

    2003-05-15

    Even young children can distinguish a Tyrannosaurus rex from a Brontosaurus by observing differences in bone size, shape, number and arrangement, that is, skeletal pattern. But despite our extensive knowledge about cartilage and bone formation per se, it is still largely a mystery how skeletal pattern is established. Much of what we do know has been learned from studying limb development in chicken and mouse embryos. Based on the data from such studies, models for how limb skeletal pattern is established have been proposed and continue to be hotly debated.

  2. Dlx-5 in limb initiation in the chick embryo.

    PubMed

    Ferrari, D; Harrington, A; Dealy, C N; Kosher, R A

    1999-09-01

    Dlx-5 is a vertebrate homolog of the Drosophila Distal-less gene, one of the first genetic signals for limb formation in the fly. In the present study we have explored the possible role of Dlx-5 in limb initiation in the chick embryo. At stage 14 which is well before the initial formation of limb buds Dlx-5 is highly and specifically expressed in the ectoderm of the presumptive wing and leg forming regions of the lateral plate, but not in the intervening non-limb forming prospective flank. Thus, Dlx-5 expression distinguishes the limb-forming territories prior to limb budding, and is one of the first molecular markers of vertebrate limb initiation. Furthermore, Dlx-5 expression is induced in the non-limb-forming flank within 12 hours after implantation of an FGF2-soaked bead, a procedure that results in the induction of an ectopic limb. The rapid induction of Dlx-5 expression in response to a signal which ultimately leads to supernumerary limb formation is consistent with a role for Dlx-5 in limb initiation. We have also examined the expression of Dlx-5 in the limb buds of amelic limbless mutant chick embryos, which undergo normal limb formation but do not form an AER and thus fail to undergo further outgrowth. Dlx-5 is transiently expressed by the ectoderm of emergent limbless limb buds, consistent with a role for Dlx-5 in limb initiation. Together, our results suggest that Dlx-5 may be involved in the specification of the limb territories of the lateral plate, and in the initial formation of the limb bud from these regions. Dev Dyn 1999;216:10-15.

  3. Chronic Pain Associated with Upper-Limb Loss

    PubMed Central

    Hanley, Marisol A.; Ehde, Dawn M.; Jensen, Mark; Czerniecki, Joseph; Smith, Douglas G.; Robinson, Lawrence R.

    2011-01-01

    Objective To describe the prevalence, intensity, and functional impact of the following types of pain associated with upper-limb loss: phantom limb, residual limb, back, neck, and nonamputated-limb pain. Design Cross-sectional survey; 104 respondents with upper-limb loss at least 6 months postamputation completed measures of pain intensity, interference, disability, and health-related quality-of-life. Results Nearly all (90%) of the respondents reported pain, with 76% reporting more than one pain type. Phantom-limb pain and residual-limb pain were the most prevalent (79% and 71%, respectively), followed by back (52%), neck (43%), and nonamputated-limb pain (33%). Although nonamputated-limb pain was least prevalent, it was reported to cause the highest levels of interference and pain-related disability days. Self-reported quality-of-life was significantly lower for individuals with each type of pain compared with those without any pain. Age, time since amputation, and cause of amputation were not associated with pain. Conclusions In addition to pain in the phantom and residual limb, back, neck, and nonamputated-limb pain are also common after upper-limb loss. All of these pain types are associated with significant disability and activity interference for some individuals, suggesting that assessment of multiple pain types in persons with upper-limb amputation may be important. PMID:19692791

  4. Vertebrate limb development and possible clues to diversity in limb form.

    PubMed

    Tickle, Cheryll

    2002-04-01

    Chick embryos are good models for vertebrate development. The principles that underlie chick wing development have been discovered and there is increasing knowledge about the molecules involved. The importance of identifying molecules is that this provides a direct link to understanding the genetic basis of diversity in form. Chick wing development will be compared with limb development in other vertebrates. Possible mechanisms that could lead to variations in form, including limb reductions and limblessness, differences between fore- and hindlimbs, limb proportions, and interdigital webbing can be suggested.

  5. Lesion Characteristics of Individuals With Upper Limb Spasticity After Stroke.

    PubMed

    Cheung, Daniel K; Climans, Seth A; Black, Sandra E; Gao, Fuqiang; Szilagyi, Gregory M; Mochizuki, George

    2016-01-01

    This study explores the relationship between lesion location and volume and upper limb spasticity after stroke. Ninety-seven stroke patients (51 with spasticity) were included in the analysis (age = 67.5 ± 13.3 years, 57 males). Lesions were traced from computed tomography and magnetic resonance images and coregistered to a symmetrical brain template. Lesion overlays from the nonspastic group were subtracted from the spastic group to determine the regions of the brain more commonly lesioned in spastic patients. Similar analysis was performed across groups of participants whose upper limb (elbow or wrist) Modified Ashworth Scale (MAS) score ranged from 1 (mild) to 4 (severe). Following subtraction analysis and Fisher's exact test, the putamen was identified as the area most frequently lesioned in individuals with spasticity. More severe spasticity was associated with a higher lesion volume. This study establishes the neuroanatomical correlates of poststroke spasticity and describes the relationship between lesion characteristics and the severity of spasticity using mixed brain imaging modalities, including computed tomography imaging, which is more readily available to clinicians. Understanding the association between lesion location and volume with the development and severity of spasticity is an important first step toward predicting the development of spasticity after stroke. Such information could inform the implementation of intervention strategies during the recovery process to minimize the extent of impairment.

  6. When a Parent Loses a Limb: Helping Children Cope

    MedlinePlus

    ... us Digg Facebook Google Bookmarks Technorati Yahoo MyWeb Click here for optional PDF format. Requires Adobe Acrobat ... socket, limb, residual limb and prosthetist. Avoid adverse reactions, such as a child who cries or screams ...

  7. Functional specialisation of pelvic limb anatomy in horses (Equus caballus)

    PubMed Central

    Payne, RC; Hutchinson, JR; Robilliard, JJ; Smith, NC; Wilson, AM

    2005-01-01

    We provide quantitative anatomical data on the muscle–tendon units of the equine pelvic limb. Specifically, we recorded muscle mass, fascicle length, pennation angle, tendon mass and tendon rest length. Physiological cross sectional area was then determined and maximum isometric force estimated. There was proximal-to-distal reduction in muscle volume and fascicle length. Proximal limb tendons were few and, where present, were relatively short. By contrast, distal limb tendons were numerous and long in comparison to mean muscle fascicle length, increasing potential for elastic energy storage. When compared with published data on thoracic limb muscles, proximal pelvic limb muscles were larger in volume and had shorter fascicles. Distal limb muscle architecture was similar in thoracic and pelvic limbs with the exception of flexor digitorum lateralis (lateral head of the deep digital flexor), the architecture of which was similar to that of the pelvic and thoracic limb superficial digital flexors, suggesting a functional similarity. PMID:15960766

  8. Measurement of limb blood flow by electrical impedance plethysmography.

    PubMed Central

    Porter, J. M.; Swain, I. D.; Shakespeare, P. G.

    1985-01-01

    Limb blood flow has been measured in 72 individuals by the noninvasive technique of electrical impedance plethysmography. Venous occlusion was not used. Blood flow was measured in 230 limbs in which 195 limbs were either in normal individuals or the clinically normal limbs of patients (normal limbs). Thirty-five limbs were clinically abnormal. Measurements on limbs with clinical abnormalities showed that blood flow values often fell within the limits of the normal range. However 3 cases of known vascular injury and 2 cases studied after hand surgery under tourniquet showed lowered blood flow values by comparison with the unaffected limb. A simultaneously recorded range of cardiac output and stroke volume measurements gave similar results to those obtained in a previous, unconnected study. Images Fig. 1 PMID:4004047

  9. Mobile-bearing medial unicompartmental knee arthroplasty restores limb alignment comparable to that of the unaffected contralateral limb

    PubMed Central

    Mullaji, Arun B; Shah, Siddharth; Shetty, Gautam M

    2017-01-01

    Background and purpose — Medial unicompartmental knee arthroplasty (UKA) is undertaken in patients with a passively correctable varus deformity. We investigated whether restoration of natural soft tissue tension would result in a lower limb alignment similar to that of the contralateral unaffected lower limb after mobile-bearing medial UKA. Patients and methods — In this retrospective study, hip-knee-ankle (HKA) angle, position of the weight-bearing axis (WBA), and knee joint line obliquity (KJLO) after mobile-bearing medial UKA was compared with that of the unaffected (clinically and radiologically) contralateral lower limb in 123 patients. Results — Postoperatively, HKA angle was restored to within ±3° of the contralateral lower limb in 87% of the patients and the WBA passed within ±1 Kennedy and White’s tibial zone of the unaffected contralateral lower limb in 95% of the patients. The mean KJLO in the operated limbs was not significantly different from that in the unaffected lower limbs (p = 0.07) and the KJLO in the operated limb was restored to within ±3° of that in the contralateral lower limb in 96% of the patients. Interpretation — Lower limb alignment and knee joint line obliquity after mobile-bearing medial UKA were comparable to that of the unaffected contralateral limb in most patients. Comparison with the contralateral unaffected lower limb is a reliable method for evaluation and validation of limb mechanical alignment after mobile-bearing medial UKA. PMID:27794622

  10. Limb disparity and wing shape in pterosaurs.

    PubMed

    Dyke, G J; Nudds, R L; Rayner, J M V

    2006-07-01

    The limb proportions of the extinct flying pterosaurs were clearly distinct from their living counterparts, birds and bats. Within pterosaurs, however, we show that further differences in limb proportions exist between the two main groups: the clade of short-tailed Pterodactyloidea and the paraphyletic clades of long-tailed rhamphorhynchoids. The hindlimb to forelimb ratios of rhamphorhynchoid pterosaurs are similar to that seen in bats, whereas those of pterodactyloids are much higher. Such a clear difference in limb ratios indicates that the extent of the wing membrane in rhamphorhynchoids and pterodactyloids may also have differed; this is borne out by simple ternary analyses. Further, analyses also indicate that the limbs of Sordes pilosus, a well-preserved small taxon used as key evidence for inferring the extent and shape of the wing membrane in all pterosaurs, are not typical even of its closest relatives, other rhamphorhynchoids. Thus, a bat-like extensive hindlimb flight membrane, integrated with the feet and tail may be applicable only to a small subset of pterosaur diversity. The range of flight morphologies seen in these extinct reptiles may prove much broader than previously thought.

  11. What Determines Limb Selection for Reaching?

    ERIC Educational Resources Information Center

    Helbig, Casi Rabb; Gabbard, Carl

    2004-01-01

    While motor dominance appears to drive limb selection for reaching movements at the midline and ipsilateral (dominant) side, this study examined the possible determinants associated with what drives the programming of movements in response to stimuli presented in contralateral space. Experiment 1 distinguished between object proximity and a…

  12. Use and Usefulness of Lower Limb Prostheses.

    ERIC Educational Resources Information Center

    Buijk, Catharina A.

    1988-01-01

    Adults (n=181) in the Netherlands were surveyed concerning their use of lower limb prostheses. Results are analyzed in terms of age and sex of users, reason for amputation, level of amputation, description of prosthesis, amount of time able to walk or stand, satisfaction with the prosthesis, and user recommendations. (JDD)

  13. Io with Loki Plume on Bright Limb

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Voyager 1 image of Io showing active plume of Loki on limb. Heart-shaped feature southeast of Loki consists of fallout deposits from active plume Pele. The images that make up this mosaic were taken from an average distance of approximately 490,000 kilometers (340,000 miles).

  14. Rotations of Lower Limbs in Skiing.

    ERIC Educational Resources Information Center

    Twardokens, George R.

    This is a short paper about turns in skiing. It contrasts early and contemporary techniques and discusses biomechanical studies of rotation of limbs. It is stated that individual people's builds partially determine how they will accomplish turns. Diagrams are included. (CD)

  15. Upper Limb Motor Impairment Post Stroke

    PubMed Central

    Raghavan, Preeti

    2016-01-01

    Synopsis Understanding upper limb impairment after stroke is essential to planning therapeutic efforts to restore function. However determining which upper limb impairment to treat and how is complex for two reasons: 1) the impairments are not static, i.e. as motor recovery proceeds, the type and nature of the impairments may change; therefore the treatment needs to evolve to target the impairment contributing to dysfunction at a given point in time. 2) multiple impairments may be present simultaneously, i.e., a patient may present with weakness of the arm and hand immediately after a stroke, which may not have resolved when spasticity sets in a few weeks or months later; hence there may be a layering of impairments over time making it difficult to decide what to treat first. The most useful way to understand how impairments contribute to upper limb dysfunction may be to examine them from the perspective of their functional consequences. There are three main functional consequences of impairments on upper limb function are: (1) learned nonuse, (2) learned bad-use, and (3) forgetting as determined by behavioral analysis of tasks. The impairments that contribute to each of these functional limitations are described. PMID:26522900

  16. Neurofibromatosis with unilateral lower limb gigantism.

    PubMed

    Sabbioni, Giacomo; Rani, Nicola; Devescovi, Valentina

    2010-05-01

    The case of a 3-year-old child diagnosed with Type 1 neurofibromatosis is presented, showing pigmented birthmarks and gigantism of the left lower limb associated with the presence of multiple neurofibromas. Increased bone growth appears to be the direct or indirect consequence of a still undefined paracrine effect of nerve tumor cells.

  17. Effect of single-limb inertial loading on bilateral reaching: interlimb interactions.

    PubMed

    Hatzitaki, V; McKinley, P

    2001-09-01

    This study employed the paradigm of asymmetric limb loading during bilateral arm reaching to examine the motor system's ability to independently organize the discrete movement of both upper limbs to equidistant targets when one of the limbs is loaded under specific timing constraints. The loading procedure involved attaching two different Velcro strapped weights to the right wrist, thus increasing the right arm's mass by 25% (1 kg) and 50% (2 kg). Movements were captured by a high-speed digital camera (240 Hz), while electromyographic (EMG) activity of selected elbow and shoulder muscles of both limbs was recorded (1,000 Hz) simultaneously. The results revealed that the mechanisms used by the system to compensate for unilateral limb loading were as follows: First, addition of an inertial load resulted in an increased movement time and concomitant decrease in peak velocity of both the upper arm and forearm of only the loaded limb and was scaled to the added weight. Second, for the EMG parameters, adjustments to the inertial load were primarily characterized by an increase in burst duration of all muscles, with load-specific changes in activity and onset time: the elbow antagonist (biceps) demonstrated a decrease in activity with the 50% load, and the elbow agonist (triceps) had an earlier onset with the 25% load. Concomitant adjustments on the unloaded limb consisted primarily of an increase in burst duration of the shoulder and elbow agonists (pectoralis and triceps), an earlier triceps onset solely with the 25% load, and a decrease in activity of the biceps solely with the 50% load. Third, with the exception of biceps activity, the amplitude of EMG activity was invariant across changes in load for both the loaded and unloaded limb. This lack of modulation in activity may have been related to the inability of performers to meet the time constraint of simultaneous bilateral limb arrival to the end targets. This inability can be the result of an active strategy

  18. Effects of Robot-assisted therapy on upper limb recovery after stroke: A Systematic Review

    PubMed Central

    Kwakkel, Gert; Kollen, Boudewijn J.; Krebs, Hermano I.

    2009-01-01

    Background and Purpose To present a systematic review of studies that investigates the effects of robot-assisted therapy on motor and functional recovery in patients with stroke. Summary of Review A database of articles published up to October 2006 was compiled using the following MEDLINE key words: cerebral vascular accident, cerebral vascular disorders, stroke, paresis, hemiplegia, upper extremity, arm and robot. References listed in relevant publications were also screened. Studies that satisfied the following selection criteria were included: (1) patients were diagnosed with cerebral vascular accident; (2) effects of robot-assisted therapy for the upper limb were investigated; (3) the outcome was measured in terms of motor and/or functional recovery of the upper paretic limb; (4) The study was a randomised clinical trial (RCT). For each outcome measure, the estimated effect size (ES) and the summary effect size (SES) expressed in standard deviation units (SDU) were calculated for motor recovery and functional ability (ADL) using fixed and random effect models. Ten studies, involving 218 patients, were included in the synthesis. Their methodological quality ranged from 4 to 8 on a (maximum) 10 point scale. Meta-analysis showed a non-significant heterogeneous SES in terms of upper limb motor recovery. Sensitivity analysis of studies involving only shoulder-elbow robotics subsequently demonstrated a significant homogeneous SES for motor recovery of the upper paretic limb. No significant SES was observed for functional ability (ADL). Conclusion As a result of marked heterogeneity in studies between distal and proximal arm robotics, no overall significant effect in favour of robot-assisted therapy was found in the present meta-analysis. However, subsequent sensitivity analysis showed a significant improvement in upper limb motor function after stroke for upper arm robotics. No significant improvement was found in ADL function. However, the administered ADL scales in

  19. Geophysical implications of Io limb profile data

    NASA Astrophysics Data System (ADS)

    Nimmo, F.; Thomas, P. C.

    2013-12-01

    Limb profiles can be used both to determine a body's long-wavelength shape, and to infer its averaged elastic thickness [1]. Here we apply previously-developed techniques [1] to analyze Galileo limb profiles for Io [2], for comparison with control-point network analysis [3]. We determine Io's long-wavelength topography at spherical harmonic degrees 3 and 4. The amplitude of the topography is +/- 0.5 km, small compared to the degree-2 (tidal and rotational) shape. The l=4 components contain 4 times more power than l=3, consistent with tidal heating playing a role in producing topography [e.g. 4]. However, the topographic pattern is anti-symmetric about the equator, which is not expected from tidal models. Nor does the topography correlate with the global pattern of volcanoes and mountains [5]. The variation in limb profile roughness with wavelength can be used to infer an elastic thickness [1,6]. In the case of Io, despite local mountains, overall the topography is quite smooth. The highest-resolution limb profiles suggest an elastic thickness of about 50 km, higher than that of other outer solar system satellites [1]. This value is consistent with previous estimates based on the existence of mountains [7] and expectations of a thick, cold lid resulting from Io's heat loss being dominated by erupting melt [8]. [1] Nimmo et al. JGR 2011 [2] Thomas et al. Icarus 1998 [3] Oberst and Schuster JGR 2004 [4] Ross et al. Icarus 1990 [5] Kirchoff et al. EPSL 2011 [6] Araki et al. Science 2009 [7] Carr et al. Icarus 1998 [8] O'Reilly and Davies GRL 1981 Io long-wavelength topography, obtained from limb profile data and expanded from l=m=3 to l=m=4. Contour interval 0.1 km.

  20. Internal models of limb dynamics and the encoding of limb state

    NASA Astrophysics Data System (ADS)

    Hwang, Eun Jung; Shadmehr, Reza

    2005-09-01

    Studies of reaching suggest that humans adapt to novel arm dynamics by building internal models that transform planned sensory states of the limb, e.g., desired limb position and its derivatives, into motor commands, e.g., joint torques. Earlier work modeled this computation via a population of basis elements and used system identification techniques to estimate the tuning properties of the bases from the patterns of generalization. Here we hypothesized that the neural representation of planned sensory states in the internal model might resemble the signals from the peripheral sensors. These sensors normally encode the limb's actual sensory state in which movement errors occurred. We developed a set of equations based on properties of muscle spindles that estimated spindle discharge as a function of the limb's state during reaching and drawing of circles. We then implemented a simulation of a two-link arm that learned to move in various force fields using these spindle-like bases. The system produced a pattern of adaptation and generalization that accounted for a wide range of previously reported behavioral results. In particular, the bases showed gain-field interactions between encoding of limb position and velocity, very similar to the gain fields inferred from behavioral studies. The poor sensitivity of the bases to limb acceleration predicted behavioral results that were confirmed by experiment. We suggest that the internal model of limb dynamics is computed by the brain with neurons that encode the state of the limb in a manner similar to that expected of muscle spindle afferents.

  1. The axolotl limb blastema: cellular and molecular mechanisms driving blastema formation and limb regeneration in tetrapods

    PubMed Central

    McCusker, Catherine; Bryant, Susan V.

    2015-01-01

    Abstract The axolotl is one of the few tetrapods that are capable of regenerating complicated biological structures, such as complete limbs, throughout adulthood. Upon injury the axolotl generates a population of regeneration‐competent limb progenitor cells known as the blastema, which will grow, establish pattern, and differentiate into the missing limb structures. In this review we focus on the crucial early events that occur during wound healing, the neural−epithelial interactions that drive the formation of the early blastema, and how these mechanisms differ from those of other species that have restricted regenerative potential, such as humans. We also discuss how the presence of cells from the different axes of the limb is required for the continued growth and establishment of pattern in the blastema as described in the polar coordinate model, and how this positional information is reprogrammed in blastema cells during regeneration. Multiple cell types from the mature limb stump contribute to the blastema at different stages of regeneration, and we discuss the contribution of these types to the regenerate with reference to whether they are “pattern‐forming” or “pattern‐following” cells. Lastly, we explain how an engineering approach will help resolve unanswered questions in limb regeneration, with the goal of translating these concepts to developing better human regenerative therapies. PMID:27499868

  2. Effects of prosthetic limb prescription on 3-year mortality among Veterans with lower-limb amputation.

    PubMed

    Kurichi, Jibby E; Kwong, Pui; Vogel, W Bruce; Xie, Dawei; Cowper Ripley, Diane; Bates, Barbara E

    2015-01-01

    Our objective was to determine the relationship between receipt of a prescription for a prosthetic limb and 3 yr mortality postsurgery among Veterans with lower-limb amputation (LLA). We conducted a retrospective observational study that included 4,578 Veterans hospitalized for LLA and discharged in fiscal years 2003 and 2004. The outcome was time to all-cause mortality from the amputation surgical date up to the 3 yr anniversary of the surgical date. Of the Veterans with LLA, 1,300 (28.4%) received a prescription for a prosthetic limb within 1 yr after the surgical amputation. About 46% (n = 2,086) died within 3 yr of the surgical anniversary. Among those who received a prescription for a prosthetic limb, only 25.2% died within 3 yr of the surgical anniversary. After adjustment, Veterans who received a prescription for a prosthetic limb were less likely to die after the surgery than Veterans without a prescription, with a hazard ratio of 0.68 (95% confidence interval: 0.60-0.77). Findings demonstrated that Veterans with LLA who received a prescription for a prosthetic limb within 1 yr after the surgical amputation were less likely to die within 3 yr of the surgical amputation after controlling for patient-, treatment-, and facility-level characteristics.

  3. Relationship of metabolic syndrome and its components with -844 G/A and HindIII C/G PAI-1 gene polymorphisms in Mexican children

    PubMed Central

    2012-01-01

    Background Several association studies have shown that -844 G/A and HindIII C/G PAI-1 polymorphisms are related with increase of PAI-1 levels, obesity, insulin resistance, glucose intolerance, hypertension and dyslipidemia, which are components of metabolic syndrome. The aim of this study was to analyze the allele and genotype frequencies of these polymorphisms in PAI-1 gene and its association with metabolic syndrome and its components in a sample of Mexican mestizo children. Methods This study included 100 children with an age range between 6-11 years divided in two groups: a) 48 children diagnosed with metabolic syndrome and b) 52 children metabolically healthy without any clinical and biochemical alteration. Metabolic syndrome was defined as the presence of three or more of the following criteria: fasting glucose levels ≥ 100 mg/dL, triglycerides ≥ 150 mg/dL, HDL-cholesterol < 40 mg/dL, obesity BMI ≥ 95th percentile, systolic blood pressure (SBP) and diastolic blood pressure (DBP) ≥ 95th percentile and insulin resistance HOMA-IR ≥ 2.4. The -844 G/A and HindIII C/G PAI-1 polymorphisms were analyzed by PCR-RFLP. Results For the -844 G/A polymorphism, the G/A genotype (OR = 2.79; 95% CI, 1.11-7.08; p = 0.015) and the A allele (OR = 2.2; 95% CI, 1.10-4.43; p = 0.015) were associated with metabolic syndrome. The -844 G/A and A/A genotypes were associated with increase in plasma triglycerides levels (OR = 2.6; 95% CI, 1.16 to 6.04; p = 0.02), decrease in plasma HDL-cholesterol levels (OR = 2.4; 95% CI, 1.06 to 5.42; p = 0.03) and obesity (OR = 2.6; 95% CI, 1.17-5.92; p = 0.01). The C/G and G/G genotypes of the HindIII C/G polymorphism contributed to a significant increase in plasma total cholesterol levels (179 vs. 165 mg/dL; p = 0.02) in comparison with C/C genotype. Conclusions The -844 G/A PAI-1 polymorphism is related with the risk of developing metabolic syndrome, obesity and atherogenic dyslipidemia, and the HindIII C/G PAI-1 polymorphism was

  4. Extended electrophoresis resolves the dystrophin gene 5. 2-kbp cDMD4-5a/HindIII fragment into two bands

    SciTech Connect

    Otto, Y.M.; Rothberg, P.G. )

    1992-12-01

    A 1% agarose gel is electrophoresed at 1.6V/cm for 16 h, the buffer is changed, unused lanes are loaded with samples, and electrophoresis is resumed for 4 h at 2.5V/cm. Short electrophoresis gave the expected pattern but long electrophoresis resolved the 5.2-kbp fragment into two bands estimated at 5.20 and 5.15 kbp. It is unlikely that this is a polymorphic fragment or the product of partial digestion. This finding may represent another exon in this region detectable using HindIII digestion.

  5. The Effect of an Upper Limb Rehabilitation Robot on Hemispatial Neglect in Stroke Patients

    PubMed Central

    2016-01-01

    Objective To investigate the effectiveness of an upper limb rehabilitation robot therapy on hemispatial neglect in stroke patients. Methods Patients were randomly divided into an upper limb rehabilitation robot treatment group (robot group) and a control group. The patients in the robot group received left upper limb training using an upper limb rehabilitation robot. The patients sat on the right side of the robot, so that the monitor of the robot was located on the patients' left side. In this position, patients could focus continuously on the left side. The control group received conventional neglect treatment, such as visual scanning training and range of motion exercises, administered by occupational therapists. Both groups received their respective therapies for 30 minutes a day, 5 days a week for 3 weeks. Several tests were used to evaluate treatment effects before and after the 3-week treatment. Results In total, 38 patients (20 in the robot group and 18 in the control group) completed the study. After completion of the treatment sessions, both groups showed significant improvements in the Motor-Free Visual Perception Test 3rd edition (MVPT-3), the line bisection test, the star cancellation test, the Albert's test, the Catherine Bergego scale, the Mini-Mental State Examination and the Korean version of Modified Barthel Index. The changes in all measurements showed no significant differences between the two groups. Conclusion This present study showed that the upper limb robot treatment had benefits for hemispatial neglect in stroke patients that were similar to conventional neglect treatment. The upper limb robot treatment could be a therapeutic option in the treatment of hemispatial neglect after stroke. PMID:27606267

  6. Comparative analysis of speech impairment and upper limb motor dysfunction in Parkinson's disease.

    PubMed

    Rusz, Jan; Tykalová, Tereza; Krupička, Radim; Zárubová, Kateřina; Novotný, Michal; Jech, Robert; Szabó, Zoltán; Růžička, Evžen

    2017-04-01

    It is currently unknown whether speech and limb motor effectors in Parkinson's disease (PD) are controlled by similar underlying brain processes. Based on computerized objective analysis, the aim of this study was to evaluate potential correlation between speech and mechanical tests of upper limb motor function. Speech and upper limb motor tests were performed in 22 PD patients and 22 healthy controls. Quantitative acoustic analyses of eight key speech dimensions of hypokinetic dysarthria, including quality of voice, sequential motion rates, consonant articulation, vowel articulation, average loudness, loudness variability, pitch variability, and number of pauses, were performed. Upper limb movements were assessed using the motor part of the Unified Parkinson's Disease Rating Scale, contactless three-dimensional motion capture system, blinded expert evaluation, and the Purdue Pegboard Test. Significant relationships were observed between the quality of voice assessed by jitter and amplitude decrement of finger tapping (r = 0.61, p = 0.003), consonant articulation evaluated using voice onset time and expert rating of finger tapping (r = 0.60, p = 0.003), and number of pauses and Purdue Pegboard Test score (r = 0.60, p = 0.004). The current study supports the hypothesis that speech impairment in PD shares, at least partially, similar pathophysiological processes with limb motor dysfunction. Vocal fold vibration irregularities appeared to be influenced by mechanisms similar to amplitude decrement during repetitive limb movements. Consonant articulation deficits were associated with decreased manual dexterity and movement speed, likely reflecting fine motor control involvement in PD.

  7. Effect of Upper Limb Deformities on Gross Motor and Upper Limb Functions in Children with Spastic Cerebral Palsy

    ERIC Educational Resources Information Center

    Park, Eun Sook; Sim, Eun Geol; Rha, Dong-wook

    2011-01-01

    The aims of this study were to investigate the nature and extent of upper limb deformities via the use of various classifications, and to analyze the relationship between upper limb deformities and gross motor or upper limb functionality levels. Upper extremity data were collected from 234 children with spastic cerebral palsy (CP) who were…

  8. Technologies Assessing Limb Bradykinesia in Parkinson’s Disease

    PubMed Central

    Hasan, Hasan; Athauda, Dilan S.; Foltynie, Thomas; Noyce, Alastair J.

    2017-01-01

    Background: The MDS-UPDRS (Movement Disorders Society – Unified Parkinson’s Disease Rating Scale) is the most widely used scale for rating impairment in PD. Subscores measuring bradykinesia have low reliability that can be subject to rater variability. Novel technological tools can be used to overcome such issues. Objective: To systematically explore and describe the available technologies for measuring limb bradykinesia in PD that were published between 2006 and 2016. Methods: A systematic literature search using PubMed (MEDLINE), IEEE Xplore, Web of Science, Scopus and Engineering Village (Compendex and Inspec) databases was performed to identify relevant technologies published until 18 October 2016. Results: 47 technologies assessing bradykinesia in PD were identified, 17 of which offered home and clinic-based assessment whilst 30 provided clinic-based assessment only. Of the eligible studies, 7 were validated in a PD patient population only, whilst 40 were tested in both PD and healthy control groups. 19 of the 47 technologies assessed bradykinesia only, whereas 28 assessed other parkinsonian features as well. 33 technologies have been described in additional PD-related studies, whereas 14 are not known to have been tested beyond the pilot phase. Conclusion: Technology based tools offer advantages including objective motor assessment and home monitoring of symptoms, and can be used to assess response to intervention in clinical trials or routine care. This review provides an up-to-date repository and synthesis of the current literature regarding technology used for assessing limb bradykinesia in PD. The review also discusses the current trends with regards to technology and discusses future directions in development. PMID:28222539

  9. Clustering-based limb identification for pressure ulcer risk assessment.

    PubMed

    Baran Pouyan, M; Nourani, M; Pompeo, M

    2015-01-01

    Bedridden patients have a high risk of developing pressure ulcers. Risk assessment for pressure ulceration is critical for preventive care. For a reliable assessment, we need to identify and track the limbs continuously and accurately. In this paper, we propose a method to identify body limbs using a pressure mat. Three prevalent sleep postures (supine, left and right postures) are considered. Then, predefined number of limbs (body parts) are identified by applying Fuzzy C-Means (FCM) clustering on key attributes. We collected data from 10 adult subjects and achieved average accuracy of 93.2% for 10 limbs in supine and 7 limbs in left/right postures.

  10. RESIDUAL LIMB VOLUME CHANGE: SYSTEMATIC REVIEW OF MEASUREMENT AND MANAGEMENT

    PubMed Central

    Sanders, JE; Fatone, S

    2014-01-01

    Management of residual limb volume affects decisions regarding timing of fit of the first prosthesis, when a new prosthetic socket is needed, design of a prosthetic socket, and prescription of accommodation strategies for daily volume fluctuations. The purpose of this systematic review was to assess what is known about measurement and management of residual limb volume change in persons with lower-limb amputation. Publications that met inclusion criteria were grouped into three categories: (I) descriptions of residual limb volume measurement techniques; (II) studies on people with lower-limb amputation investigating the effect of residual limb volume change on clinical care; and (III) studies of residual limb volume management techniques or descriptions of techniques for accommodating or controlling residual limb volume. The review showed that many techniques for the measurement of residual limb volume have been described but clinical use is limited largely because current techniques lack adequate resolution and in-socket measurement capability. Overall, there is limited evidence regarding the management of residual limb volume, and the evidence available focuses primarily on adults with trans-tibial amputation in the early post-operative phase. While we can draw some insights from the available research about residual limb volume measurement and management, further research is required. PMID:22068373

  11. Imparting regenerative capacity to limbs by progenitor cell transplantation

    PubMed Central

    Lin, Gufa; Chen, Ying; Slack, Jonathan M.W.

    2012-01-01

    Summary The frog Xenopus can normally regenerate its limbs at early developmental stages but loses the ability during metamorphosis. This behavior provides a potential gain-of-function model for measures that can enhance limb regeneration. Here we show that frog limbs can be caused to form multidigit regenerates after receiving transplants of larval limb progenitor cells. It is necessary to activate Wnt/β -catenin signaling in the cells, and to add Sonic hedgehog, FGF10 and thymosin β4. These factors promote survival and growth of the grafted cells and also provide pattern information. The eventual regenerates are not composed solely of donor tissue; the host cells also make a substantial contribution despite their lack of regeneration-competence. Cells from adult frog legs or from regenerating tadpole tails do not promote limb regeneration, demonstrating the necessity for limb progenitor cells. These findings have obvious implications for the development of a technology to promote limb regeneration in mammals. PMID:23273877

  12. One of the most urgent vascular circumstances: Acute limb ischemia

    PubMed Central

    Sahin, Muslum; Kirma, Cevat

    2013-01-01

    Acute limb ischemia is a sudden decrease in limb perfusion that threatens limb viability and requires urgent evaluation and management. Most of the causes of acute limb ischemia are thrombosis of a limb artery or bypass graft, embolism from the heart or a disease artery, dissection, and trauma. Assessment determines whether the limb is viable or irreversibly damaged. Prompt diagnosis and revascularization by means of catheter-based thrombolysis or thrombectomy and by surgery reduce the risk of limb loss and mortality. Amputation is performed in patients with irreversible damage. Despite urgent revascularization, amputation rate is 10%–15% in patients during hospitalization, mostly above the knee, and mortality within 1 year is 10%–15% due to the coexisting conditions. PMID:26770694

  13. Generation of pattern and form in the developing limb.

    PubMed

    Towers, Matthew; Tickle, Cheryll

    2009-01-01

    The developing limb is a major model for pattern formation in vertebrate embryos. Many of the seminal discoveries of the mechanisms involved in patterning have been made using chick embryos because of the ease of manipulating their developing limbs. More recently, the molecular basis of limb pattern formation has been increasingly uncovered and now, with the availability of genomic resources, the genetic approaches available are even more powerful. Nevertheless, since the limb is ultimately built of cells, gene action must ultimately be translated into cell behaviour and a major challenge will be to integrate genetics with molecular and cellular biology. In this review, we will first outline the stages in limb development, the major interacting signalling pathways that pattern the limb and the molecules involved. We will describe fate maps of the developing limb, and discuss what is known about cellular activities including proliferation, death, adhesiveness, communication and migration during the patterning process. Finally we will explore how these cell activities produce form.

  14. SPORTS INJURIES OF THE UPPER LIMBS

    PubMed Central

    da Silva, Rogerio Teixeira

    2015-01-01

    Sports injuries of the upper limbs are very common in physical activities and therefore, they need to be studied in detail, taking into consideration specific aspects of the types of sports practiced. Special attention should be paid to the dynamics of the shoulder girdle and the entire scapular belt, since the most appropriate treatment for athletes can only be provided in this manner. This can also help to prevent recurrences, which can occur in some cases because athletes always seek to return to their pre-injury level of sports activity. This article will focus primarily on the management of upper-limb tendon injuries, from the physiopathology through to the new methods of injury treatment that are more prevalent in sports practice in Brazil. PMID:27022529

  15. Rehabilitation protocol in upper limb lymphedema.

    PubMed

    Leduc, O; Leduc, A

    2002-01-01

    Edema of the upper limb is, frequently, very invalidating. The physical treatment for edema of the upper limb consists on a combination of different therapies: manual lymphatic drainage (MLD), intermittent sequential pressotherapy (IPP) with a very low intensity, multilayer bandages (MLB), and compression sleeves. Patients are not hospitalized. In the first step of physical treatment, the patients are treated daily during 2 or 3 weeks with different therapies (MLD, IPP and MLB). During the second step, bandages are no more used. The compression garments are applied after this 2 or 3 weeks period. The physical treatment consist now in: manual lynphatic drainage and intermittent sequential pressotherapy (with low intensity). The frequency of the physical treatment is progressively decreased.

  16. Lower-Limb Rehabilitation Robot Design

    NASA Astrophysics Data System (ADS)

    Bouhabba, E. M.; Shafie, A. A.; Khan, M. R.; Ariffin, K.

    2013-12-01

    It is a general assumption that robotics will play an important role in therapy activities within rehabilitation treatment. In the last decade, the interest in the field has grown exponentially mainly due to the initial success of the early systems and the growing demand caused by increasing numbers of stroke patients and their associate rehabilitation costs. As a result, robot therapy systems have been developed worldwide for training of both the upper and lower extremities. This paper investigates and proposes a lower-limb rehabilitation robot that is used to help patients with lower-limb paralysis to improve and resume physical functions. The proposed rehabilitation robot features three rotary joints forced by electric motors providing linear motions. The paper covers mechanism design and optimization, kinematics analysis, trajectory planning, wearable sensors, and the control system design. The design and control system demonstrate that the proposed rehabilitation robot is safe and reliable with the effective design and better kinematic performance.

  17. The upper limb of Australopithecus sediba.

    PubMed

    Churchill, Steven E; Holliday, Trenton W; Carlson, Kristian J; Jashashvili, Tea; Macias, Marisa E; Mathews, Sandra; Sparling, Tawnee L; Schmid, Peter; de Ruiter, Darryl J; Berger, Lee R

    2013-04-12

    The evolution of the human upper limb involved a change in function from its use for both locomotion and prehension (as in apes) to a predominantly prehensile and manipulative role. Well-preserved forelimb remains of 1.98-million-year-old Australopithecus sediba from Malapa, South Africa, contribute to our understanding of this evolutionary transition. Whereas other aspects of their postcranial anatomy evince mosaic combinations of primitive (australopith-like) and derived (Homo-like) features, the upper limbs (excluding the hand and wrist) of the Malapa hominins are predominantly primitive and suggest the retention of substantial climbing and suspensory ability. The use of the forelimb primarily for prehension and manipulation appears to arise later, likely with the emergence of Homo erectus.

  18. Stenting in Acute Lower Limb Arterial Occlusions

    SciTech Connect

    Raja, Jowad; Munneke, Graham; Morgan, Robert; Belli, Anna-Maria

    2008-07-15

    Management of critical limb ischemia of acute onset includes surgical embolectomy, bypass grafting, aspiration thrombectomy, thrombolysis, and mechanical thrombectomy followed by treatment of the underlying cause. We present our experience with the use of stents to treat acute embolic/thrombotic occlusions in one iliac and three femoropopliteal arteries. Although this is a small case series, excellent immediate and midterm results suggest that stenting of acute occlusions of the iliac, superficial femoral, and popliteal arteries is a safe and effective treatment option.

  19. Advances in lower-limb prosthetic technology.

    PubMed

    Laferrier, Justin Z; Gailey, Robert

    2010-02-01

    The boundaries once faced by individuals with amputations are quickly being overcome through biotechnology. Although there are currently no prosthetics capable of replicating anatomic function, there have been radical advancements in prosthetic technology, medical science, and rehabilitation in the past 30 years, vastly improving functional mobility and quality of life for individuals with lower-limb amputations. What once seemed impossible is rapidly becoming reality. The future seems limitless, and the replication of anatomic function now seems possible.

  20. The upper limb of Homo naledi.

    PubMed

    Feuerriegel, Elen M; Green, David J; Walker, Christopher S; Schmid, Peter; Hawks, John; Berger, Lee R; Churchill, Steven E

    2017-03-01

    The evolutionary transition from an ape-like to human-like upper extremity occurred in the context of a behavioral shift from an upper limb predominantly involved in locomotion to one adapted for manipulation. Selection for overarm throwing and endurance running is thought to have further shaped modern human shoulder girdle morphology and its position about the thorax. Homo naledi (Dinaledi Chamber, Rising Star Cave, Cradle of Humankind, South Africa) combines an australopith-like cranial capacity with dental characteristics akin to early Homo. Although the hand, foot, and lower limb display many derived morphologies, the upper limb retains many primitive traits. Here, we describe the H. naledi upper extremity (excluding the hand) in detail and in a comparative context to evaluate the diversity of clavicular, scapular, humeral, radial, and ulnar morphology among early hominins and later Homo. Homo naledi had a scapula with a markedly cranially-oriented glenoid, a humerus with extremely low torsion, and an australopith-like clavicle. These traits indicate that the H. naledi scapula was situated superiorly and laterally on the thorax. This shoulder girdle configuration is more similar to that of Australopithecus and distinct from that of modern humans, whose scapulae are positioned low and dorsally about the thorax. Although early Homo erectus maintains many primitive clavicular and humeral features, its derived scapular morphology suggests a loss of climbing adaptations. In contrast, the H. naledi upper limb is markedly primitive, retaining morphology conducive to climbing while lacking many of the derived features related to effective throwing or running purported to characterize other members of early Homo.

  1. Proximal monomelic amyotrophy of the upper limb.

    PubMed

    Amir, D; Magora, A; Vatine, J J

    1987-07-01

    A 30-year-old patient of Central European origin, suffering from monomelic amyotrophy, is presented. The disease was characterized by proximal weakness of one upper limb, mainly of the shoulder girdle, accompanied by atrophy. The electrodiagnostic examination revealed signs of partial denervation in the presence of normal motor and sensory conduction. The disease, which is probably of the anterior horn cells, had a benign course and good prognosis, as evident from repeated examinations during a follow-up of eight years.

  2. Cerebral aqueduct stenosis presenting with limb pain.

    PubMed

    Gallagher, A C; Trounce, J Q

    1998-05-01

    Two children are reported with hydrocephalus and aqueduct stenosis who presented with back and limb pains. Neither had the classic symptoms of headache and vomiting. The children had enlarged heads and later developed ataxic gait and papilloedema. The cause of the pains is uncertain but similar symptoms have been reported in subjects with benign intracranial hypertension and may relate to spinal nerve root pouch distension. Operative ventricular drainage resulted in rapid improvement of all symptoms in both children.

  3. [Limb lengthening in children with osteogenesis imperfecta].

    PubMed

    Sułko, Jerzy; Radło, Wojciech

    2005-01-01

    The authors operated on 7 children (5 girls, 2 boys) suffering from osteogenesis imperfecta (oi) type I according to Sillence classification, with lower limbs discrepancy. We elongated 10 segments (7 femurs and 3 tibias). Mean age at operation time was 14.7 years (13-17 years). The mean leg length discrepancy was 9.3 cm (4-18 cm), and shortening of one bone was 6.5 cm (4-9 cm). We used Ilizarov technique twice in tibial lengthening. We used Wagner technique in one tibial elongation and in 7 femur elongation. Except for one tibia, in the remaining cases there was Rush rod inserted intramedullary in the bone being elongated. During tibial elongation we fixed lateral malleous by screw. The osteotomy was performed in proximal metaphysis of the 5 femurs and 3 tibias, and in distal femurs in two cases. The elongation was 1 mm for day, with frequency 4 x 1/4 mm. The mean bone lengthening achieved was 5.5 cm (2-9 cm); the mean lengthening of the limb was 7.9 cm (2-18 cm). The mean time of elongation was 2.8 months (2-5 months). Elongation index was 26 days for 1 cm of lengthening. The mean time of fixator removal was 9.2 months (4-13 months). Healing index was 58 day/1 cm (overall number of days for 1 cm lengthening). The complications occurred in all the patients. Although the risk of numerous complication is high, lower limbs lengthening in children with type I osteogeneis imperfecta is possible to perform and allows equalizing discrepant limbs or, at least reducing the difference.

  4. [Risk assessment in upper limb overload].

    PubMed

    Martinelli, R; Casilli, A; Fanelli, C; Pizzuti, S; Tarquini, M; Tobia, L; Paoletti, A

    2007-01-01

    One of the most important factors of the work-related musculoskeletal disorders of the upper extremities (WMSDs) is the biomechanical overload. The purpose of this study is to evaluate the possibility to predict the upper limb repetitive stress, according to risk assessment procedures. In order to this aim, we gathered clinical-anamnestic data and risk assessment considerations of a cohort of workers in a car industry.

  5. Ultrasound of lower limb sports injuries

    PubMed Central

    Purohit, Neeraj B

    2015-01-01

    Musculoskeletal ultrasound utilises high-frequency linear transducers to produce high-resolution images of soft tissue structures. It is an increasingly useful tool in the assessment of both acute and chronic musculoskeletal injuries; it is relatively cheap, portable and can be used to facilitate targeted injections. In this review paper, we aim to provide a summary on the normal and abnormal appearances of skeletal tissue in the setting of acute and chronic lower limb sporting injuries. PMID:27433251

  6. Making digit patterns in the vertebrate limb.

    PubMed

    Tickle, Cheryll

    2006-01-01

    The vertebrate limb has been a premier model for studying pattern formation - a striking digit pattern is formed in human hands, with a thumb forming at one edge and a little finger at the other. Classic embryological studies in different model organisms combined with new sophisticated techniques that integrate gene-expression patterns and cell behaviour have begun to shed light on the mechanisms that control digit patterning, and stimulate re-evaluation of the current models.

  7. Central representation of phantom limb phenomenon in amputees studied with single photon emission computerized tomography.

    PubMed

    Liaw, M Y; You, D L; Cheng, P T; Kao, P F; Wong, A M

    1998-01-01

    To explore the possible mechanisms of phantom limb discomfort after amputation, three amputees with phantom limb pain were studied. This study examined the change of regional cerebral blood flow using technetium-99m hexamethylpropyleneamine oxime-single photon emission computerized tomography, which was arranged at the time of severe phantom limb discomfort and after the discomfort subsided or was completely relieved. Nine representative transverse slices parallel to the orbitomeatal line were selected for quantification. The cortical ribbon (2-cm thickness) was equally subdivided into 12 symmetrical pairs of sector regions of interest in each slice. The irregularly shaped regions of interest were drawn manually around the right thalamus and basal ganglion and then mirrored to the left thalamus and basal ganglion. The contralateral to ipsilateral ratio of regional cerebral blood flow for each area was calculated. The intensity of phantom limb pain was evaluated on a 0 to 10 visual analog scale. In Cases 1 and 2, the contralateral to ipsilateral regional cerebral blood flow ratios of multiple areas of the frontal, temporal, or parietal lobes were increased at the time of more severe phantom limb pain, and the ratios were normalized or even decreased when the phantom limb pain subsided. In Case 3, increased contralateral to ipsilateral regional cerebral blood flow ratios were also found over the frontal, temporal, and parietal lobe. However, most of the increased regional cerebral blood flow ratios of regions of interest in the first study persisted in the follow-up study. Also, the regional cerebral blood flow ratios of greater number of regions of interest of the same gyrus and new gyrus were increased. There was no significant right-left difference of regional cerebral blood flow over bilateral thalami and basal ganglia in all three cases. The results suggested that phantom limb pain might be associated with cortical activation involving the frontal, temporal, or

  8. Children with limb deficiencies: demographic characteristics.

    PubMed

    Al-Worikat, Abdel Fattah; Dameh, Walid

    2008-03-01

    The aim of this study is to determine the demographic data for amputations in children in relation of age, sex, level and cause of amputation. Data were collected from the records of amputees who attended the prosthetic clinic at the Royal Rehabilitation Center, King Hussein Medical Centre, Jordan, between 1 January 1995 and 31 December 2005. Demographic data (age, sex, level and cause of amputation) were analyzed. Some 120 children with different levels of amputation were included with mean age of 6.2 years. There were 64 (53.3%) males and 56 (46.7%) females. Male to female ratio was 1.15:1. The dominant level of amputation was trans-radial in 10 patients (15.62%) in the upper limb and trans-tibial in 18 patients (28.12%) in the lower limb. The dominant cause of amputation was congenital deficiency in 56 patients (46.67%) followed by trauma in 48 (40%). The results of this study presented greater similarities to others in the literature, congenital limb deficiency being the dominant cause of amputation in children. This study helps in planning the needs for materials and budgets for the treatment of amputee children in Jordan.

  9. Critical limb ischemia: medical and surgical management.

    PubMed

    Slovut, David Paul; Sullivan, Timothy M

    2008-08-01

    Chronic critical limb ischemia (CLI), defined as > 2 weeks of rest pain, ulcers, or tissue loss attributed to arterial occlusive disease, is associated with great loss of both limb and life. Therapeutic goals in treating patients with CLI include reducing cardiovascular risk factors, relieving ischemic pain, healing ulcers, preventing major amputation, improving quality of life and increasing survival. These aims may be achieved through medical therapy, revascularization, or amputation. Medical therapy includes administration of analgesics, local wound care and pressure relief, treatment of infection, and aggressive therapy to modify atherosclerotic risk factors. For patients who are not candidates for revascularization, and who are unwilling or unable to undergo amputation, treatments such as intermittent pneumatic compression or spinal cord stimulation may offer symptom relief and promote wound healing. Revascularization offers the best option for limb salvage. The decision to perform surgery, endovascular therapy, or a combination of the two modalities ('hybrid' therapy) must be individualized. Patients who are relatively fit and able to withstand the rigors of an open procedure may benefit from the long-term durability of surgical repair. In contrast, frail patients with a limited life expectancy may experience better outcomes with endovascular reconstruction. Hybrid therapy is an attractive option for patients with limited autologous conduit, as it permits complete revascularization with a less extensive procedure, shorter duration of operation, and decreased risk of peri-operative complications. Amputation should be considered for patients who are non-ambulatory, demented, or unfit to undergo revascularization.

  10. Therapeutic angiogenesis for critical limb ischemia.

    PubMed

    Ko, Sae Hee; Bandyk, Dennis F

    2014-03-01

    The application of gene- and cell-based therapies to promote angiogenesis is a novel concept to treat lower-limb critical limb ischemia (CLI) and may provide an unmet need for patients with no options for revascularization. Proof of concept was demonstrated in animal models resulting in clinical trials that have confirmed the feasibility and short-term efficacy of intramuscular injection of angiogenetic tissue growth factors or bone marrow stem cells. The safety of these biologic therapies has been demonstrated in randomized clinical trials with no "off-target" angiogenesis, growth of occult tumors, or progression of diabetic retinopathy. Current phase III randomized clinical trials using a DNA plasmid with the hepatocyte growth factor gene or bone marrow aspirate concentrate of mesenchymal cells are designed to address several crucial issues, including proper patient selection criteria, relevant clinical endpoints, and long-term efficacy. Because effectiveness of these novel therapies remains to be established, ongoing and future randomized clinical trials should be placebo-controlled, investigator-blinded, and have amputation-free survival as the primary endpoint. Further development of efficient gene transfer techniques and keeping transplanted stem cells healthy have the potential to make biologic therapies more robust in promoting angiogenesis, tissue regeneration, and resolution of CLI symptoms. If sustained efficacy can be demonstrated, new therapeutic strategies for patients with CLI will be available for clinicians, ie, limb revascularization using angiogenic gene or stem cell therapy alone, or in conjunction with endovascular intervention.

  11. The organization of upper limb physiological tremor.

    PubMed

    Carignan, Benoit; Daneault, Jean-François; Duval, Christian

    2012-04-01

    The objectives of this study are (1) to assess the relationship between tremor displacement of different segments of the upper limb, (2) to assess whether an attempt to voluntarily reduce tremor amplitude affects this relationship. Twenty-five young healthy participants were tested. Tremor of the finger, hand, arm and shoulder was assessed using laser displacement sensors while the upper limb was in a postural position. Results show strong correlations (r > 0.90), high coherence (>0.9) and in-phase movement between tremor displacement oscillations of different segments. The majority of finger tremor amplitude can be predicted by angular movement generated at the shoulder joint (r(2) > 0.86). Participants were able to voluntarily reduce tremor amplitude, but no change in the relationship between segments was observed. Tremor of all segments of the upper limb was mechanically driven by the angular movement generated at the shoulder joint. This study provides evidence that there is no compensatory organization of physiological tremor. This lays the groundwork to evaluate whether pathological tremors also lack this organization.

  12. Gap junctional communication during limb cartilage differentiation.

    PubMed

    Coelho, C N; Kosher, R A

    1991-03-01

    The onset of cartilage differentiation in the developing limb bud is characterized by a transient cellular condensation process in which prechondrogenic mesenchymal cells become closely apposed to one another prior to initiating cartilage matrix deposition. During this condensation process intimate cell-cell interactions occur which are necessary to trigger chondrogenic differentiation. In the present study, we demonstrate that extensive cell-cell communication via gap junctions as assayed by the intercellular transfer of lucifer yellow dye occurs during condensation and the onset of overt chondrogenesis in high density micromass cultures prepared from the homogeneous population of chondrogenic precursor cells comprising the distal subridge region of stage 25 embryonic chick wing buds. Furthermore, in heterogeneous micromass cultures prepared from the mesodermal cells of whole stage 23/24 limb buds, extensive gap junctional communication is limited to differentiating cartilage cells, while the nonchondrogenic cells of the cultures that are differentiating into the connective tissue lineage exhibit little or no intercellular communication via gap junctions. These results provide a strong incentive for considering and further investigating the possible involvement of cell-cell communication via gap junctions in the regulation of limb cartilage differentiation.

  13. OMPS Limb Profiler Instrument Performance Assessment

    NASA Technical Reports Server (NTRS)

    Jaross, Glen R.; Bhartia, Pawan K.; Chen, Grace; Kowitt, Mark; Haken, Michael; Chen, Zhong; Xu, Philippe; Warner, Jeremy; Kelly, Thomas

    2014-01-01

    Following the successful launch of the Ozone Mapping and Profiler Suite (OMPS) aboard the Suomi National Polar-orbiting Partnership (SNPP) spacecraft, the NASA OMPS Limb team began an evaluation of instrument and data product performance. The focus of this paper is the instrument performance in relation to the original design criteria. Performance that is closer to expectations increases the likelihood that limb scatter measurements by SNPP OMPS and successor instruments can form the basis for accurate long-term monitoring of ozone vertical profiles. The team finds that the Limb instrument operates mostly as designed and basic performance meets or exceeds the original design criteria. Internally scattered stray light and sensor pointing knowledge are two design challenges with the potential to seriously degrade performance. A thorough prelaunch characterization of stray light supports software corrections that are accurate to within 1% in radiances up to 60 km for the wavelengths used in deriving ozone. Residual stray light errors at 1000nm, which is useful in retrievals of stratospheric aerosols, currently exceed 10%. Height registration errors in the range of 1 km to 2 km have been observed that cannot be fully explained by known error sources. An unexpected thermal sensitivity of the sensor also causes wavelengths and pointing to shift each orbit in the northern hemisphere. Spectral shifts of as much as 0.5nm in the ultraviolet and 5 nm in the visible, and up to 0.3 km shifts in registered height, must be corrected in ground processing.

  14. Advanced upper limb prosthetic devices: implications for upper limb prosthetic rehabilitation.

    PubMed

    Resnik, Linda; Meucci, Marissa R; Lieberman-Klinger, Shana; Fantini, Christopher; Kelty, Debra L; Disla, Roxanne; Sasson, Nicole

    2012-04-01

    The number of catastrophic injuries caused by improvised explosive devices in the Afghanistan and Iraq Wars has increased public, legislative, and research attention to upper limb amputation. The Department of Veterans Affairs (VA) has partnered with the Defense Advanced Research Projects Agency and DEKA Integrated Solutions to optimize the function of an advanced prosthetic arm system that will enable greater independence and function. In this special communication, we examine current practices in prosthetic rehabilitation including trends in adoption and use of prosthetic devices, financial considerations, and the role of rehabilitation team members in light of our experiences with a prototype advanced upper limb prosthesis during a VA study to optimize the device. We discuss key challenges in the adoption of advanced prosthetic technology and make recommendations for service provision and use of advanced upper limb prosthetics. Rates of prosthetic rejection are high among upper limb amputees. However, these rates may be reduced with sufficient training by a highly specialized, multidisciplinary team of clinicians, and a focus on patient education and empowerment throughout the rehabilitation process. There are significant challenges emerging that are unique to implementing the use of advanced upper limb prosthetic technology, and a lack of evidence to establish clinical guidelines regarding prosthetic prescription and treatment. Finally, we make recommendations for future research to aid in the identification of best practices and development of policy decisions regarding insurance coverage of prosthetic rehabilitation.

  15. Limb lengthening and correction of deformity in the lower limbs of children with osteogenesis imperfecta.

    PubMed

    Saldanha, K A N; Saleh, M; Bell, M J; Fernandes, J A

    2004-03-01

    We performed limb lengthening and correction of deformity of nine long bones of the lower limb in six children (mean age, 14.7 years) with osteogenesis imperfecta (OI). All had femoral lengthening and three also had ipsilateral tibial lengthening. Angular deformities were corrected simultaneously. Five limb segments were treated using a monolateral external fixator and four with the Ilizarov frame. In three children, lengthening was done over previously inserted femoral intramedullary rods. The mean lengthening achieved was 6.26 cm (mean healing index, 33.25 days/cm). Significant complications included one deep infection, one fracture of the femur and one anterior angulation deformity of the tibia. The abnormal bone of OI tolerated the external fixators throughout the period of lengthening without any episodes of migration of wires or pins through the soft bone. The regenerate bone formed within the time which is normally expected in limb-lengthening procedures performed for other conditions. We conclude that despite the abnormal bone characteristics, distraction osteogenesis to correct limb-length discrepancy and angular deformity can be performed safely in children with OI.

  16. Limb Darkening study using Venus nightside infrared spectra from VIRTIS-Venus Express data

    NASA Astrophysics Data System (ADS)

    Longobardo, Andrea; Palomba, Ernesto; Zinzi, Angelo; Piccioni, Giuseppe; Tsang, Constantine C. C.; Drossart, Pierre

    2012-08-01

    The Limb Darkening (LD) effect consists in an attenuation of the measured radiance at increasing emergence angles, due to the larger portion of the atmosphere traversed by the radiation observed at higher emergence angles. The behaviour of radiance emerging with atmosphere as function of the emergence angle (i.e., the Limb Darkening Function) is related to several atmosphere and cloud properties, e.g., atmospheric opacity, temperature lapse rate, aerosol single scattering albedo, optical depth, cloud particles size, cloud scale height. In addition, the retrieval of the Limb Darkening Function allows the computation of radiances as they would be acquired in Nadir observations, which is an important process of data reduction. In this work Limb Darkening is studied on infrared images of the Venus nightside. The images are provided by the VIRTIS instrument (Visible and InfraRed Thermal Imaging Spectrometer) onboard the Venus Express mission. Analysis is performed at wavelengths characterised by emission coming from below the clouds (i.e., 1.03 μm, 1.31 μm, 1.74 μm, 2.30 μm) and from upper clouds (i.e., 3.72 μm, 4.00 μm), respectively. In the first case, the Limb Darkening Function is retrieved at different latitude ranges (-40° to 0°, -50° to -40°, -60° to -50°, -70° to -60°) and different optical depths. To this end, a novel approach is developed, based on a statistical analysis of observed data. This statistical analysis is possible thanks to the very extended dataset provided by the VIRTIS instrument. These empirical Limb Darkening Functions are then compared and interpreted with the aid of radiative transfer models. An agreement between our results and results of synthetic models is found between -60° and 0°, allowing us to consider our approach well validated. Furthermore, by means of a detailed analysis of the LDFs obtained at different latitudes, it is possible to infer a slight increase of the mode3/mode2 density ratio between -60° and -50

  17. The utility of scores in the decision to salvage or amputation in severely injured limbs.

    PubMed

    Shanmuganathan, Rajasekaran

    2008-10-01

    The decision to amputate or salvage a severely injured limb can be very challenging to the trauma surgeon. A misjudgment will result in either an unnecessary amputation of a valuable limb or a secondary amputation after failed salvage. Numerous scores have been proposed to provide guidelines to the treating surgeon, the notable of which are Mangled extremity severity score (MESS); the predictive salvage index (PSI); the Limb Salvage Index (LSI); the Nerve Injury, Ischemia, Soft tissue injury, Skeletal injury, Shock and Age of patient (NISSSA) score; and the Hannover fracture scale-97 (HFS-97). These scores have all been designed to evaluate limbs with combined orthopaedic and vascular injuries and have a poor sensitivity and specificity in evaluating IIIB injuries. Recently the Ganga Hospital Score (GHS) has been proposed which is specifically designed to evaluate a IIIB injury. Another notable feature of GHS is that it offers guidelines in the choice of the appropriate reconstruction protocol. The basis of the commonly used scores with their utility have been discussed in this paper.

  18. X-ray bursts from solar flares behind the limb. [OSO-h

    NASA Technical Reports Server (NTRS)

    Roy, J. R.; Datlowe, D. W.

    1975-01-01

    X-ray bursts are identified from the UCSD OSO-7 X-ray experiment data. X-ray spectroheliograms of OSO-5, H alpha activity at the limb, and the emergence and disappearance of sunspot groups at the limb were studied and 17 active centers were found as likely seats of the X-ray bursts beyond the limb. The analysis of 37 X-ray bursts and their physical parameters is presented. Results show that (1) the distributions of maximum temperature, maximum emission measure, and characteristic cooling time of the over-the-limb events do not significantly differ from those of disk events; (2) that radiation is the dominant cooling mechanism for the hot flare plasma; and (3) that the scale height for X-ray emission in the 5-10 keV range is large. Observations show that the fraction of soft X-ray bursts which have a nonthermal component is the same on and off of the disk. Hard X-ray emission over extended regions is indicated.

  19. Short Hairpin RNA Silencing of PHD-2 Improves Neovascularization and Functional Outcomes in Diabetic Wounds and Ischemic Limbs

    PubMed Central

    Paik, Kevin J.; Maan, Zeshaan N.; Zielins, Elizabeth R.; Duscher, Dominik; Whittam, Alexander J.; Morrison, Shane D.; Brett, Elizabeth A.; Ransom, Ryan C.; Hu, Michael S.; Wu, Joseph C.; Gurtner, Geoffrey C.; Longaker, Michael T.; Wan, Derrick C.

    2016-01-01

    The transcription factor hypoxia-inducible factor 1-alpha (HIF-1α) is responsible for the downstream expression of over 60 genes that regulate cell survival and metabolism in hypoxic conditions as well as those that enhance angiogenesis to alleviate hypoxia. However, under normoxic conditions, HIF-1α is hydroxylated by prolyl hydroxylase 2, and subsequently degraded, with a biological half-life of less than five minutes. Here we investigated the therapeutic potential of inhibiting HIF-1α degradation through short hairpin RNA silencing of PHD-2 in the setting of diabetic wounds and limb ischemia. Treatment of diabetic mouse fibroblasts with shPHD-2 in vitro resulted in decreased levels of PHD-2 transcript demonstrated by qRT-PCR, higher levels of HIF-1α as measured by western blot, and higher expression of the downstream angiogenic genes SDF-1 and VEGFα, as measured by qRT-PCR. In vivo, shPHD-2 accelerated healing of full thickness excisional wounds in diabetic mice compared to shScr control, (14.33 ± 0.45 days vs. 19 ± 0.33 days) and was associated with an increased vascular density. Delivery of shPHD-2 also resulted in improved perfusion of ischemic hind limbs compared to shScr, prevention of distal digit tip necrosis, and increased survival of muscle tissue. Knockdown of PHD-2 through shRNA treatment has the potential to stimulate angiogenesis through overexpression of HIF-1α and upregulation of pro-angiogenic genes downstream of HIF-1α, and may represent a viable, non-viral approach to gene therapy for ischemia related applications. PMID:26967994

  20. Effect of feeding growing-fattening rabbits a diet supplemented with whole white lupin (Lupinus albus cv. Amiga) seeds on fatty acid composition and indexes related to human health in hind leg meat and perirenal fat.

    PubMed

    Volek, Zdeněk; Marounek, Milan

    2011-01-01

    A total of 20 weaned rabbits (33 days old) (10 per treatment) were fed one of two diets that included 150 g of sunflower meal (SF)/kg of diet or 120 g of whole white lupin (WL)/kg of diet for 42 days. The WL diet contained less saturated fatty acids (SFA) and polyunsaturated fatty acids (PUFA) but more monounsaturated fatty acids (MUFA) than the SF diet. The WL diet significantly decreased SFA and PUFA content, as well as the PUFA n-6/PUFA n-3 ratio and saturation, atherogenic and thrombogenic indexes in hind leg meat. The fatty acid composition in perirenal fat was similar to that of hind leg meat; however, significantly higher MUFA levels were observed in rabbits fed the WL diet. Thus, feeding rabbits the WL diet affected the fatty acid profile of hind leg meat and perirenal fat in a favourable manner.

  1. Derivation and long-term culture of cells from newt adult limbs and limb blastemas.

    PubMed

    Ferretti, Patrizia; Kumar, Anoop

    2015-01-01

    Notwithstanding the key importance of in vivo models for understanding patterning and cellular interactions in the regenerating tailed amphibian (salamander) limb, dissection of molecular mechanisms, as in other species, can be greatly aided by robust in vitro models. This chapter focuses on derivation and maintenance of cell lines from adult post-metamorphic salamanders and in particular cells derived from normal and regenerating limbs. We also describe a protocol for nucleofecting newt cells that can be used both to investigate the gene function in short-term studies and to establish stable cell lines.

  2. Music Upper Limb Therapy—Integrated: An Enriched Collaborative Approach for Stroke Rehabilitation

    PubMed Central

    Raghavan, Preeti; Geller, Daniel; Guerrero, Nina; Aluru, Viswanath; Eimicke, Joseph P.; Teresi, Jeanne A.; Ogedegbe, Gbenga; Palumbo, Anna; Turry, Alan

    2016-01-01

    Stroke is a leading cause of disability worldwide. It leads to a sudden and overwhelming disruption in one’s physical body, and alters the stroke survivors’ sense of self. Long-term recovery requires that bodily perception, social participation and sense of self are restored; this is challenging to achieve, particularly with a single intervention. However, rhythmic synchronization of movement to external stimuli facilitates sensorimotor coupling for movement recovery, enhances emotional engagement and has positive effects on interpersonal relationships. In this proof-of-concept study, we designed a group music-making intervention, Music Upper Limb Therapy-Integrated (MULT-I), to address the physical, psychological and social domains of rehabilitation simultaneously, and investigated its effects on long-term post-stroke upper limb recovery. The study used a mixed-method pre-post design with 1-year follow up. Thirteen subjects completed the 45-min intervention twice a week for 6 weeks. The primary outcome was reduced upper limb motor impairment on the Fugl-Meyer Scale (FMS). Secondary outcomes included sensory impairment (two-point discrimination test), activity limitation (Modified Rankin Scale, MRS), well-being (WHO well-being index), and participation (Stroke Impact Scale, SIS). Repeated measures analysis of variance (ANOVA) was used to test for differences between pre- and post-intervention, and 1-year follow up scores. Significant improvement was found in upper limb motor impairment, sensory impairment, activity limitation and well-being immediately post-intervention that persisted at 1 year. Activities of daily living and social participation improved only from post-intervention to 1-year follow up. The improvement in upper limb motor impairment was more pronounced in a subset of lower functioning individuals as determined by their pre-intervention wrist range of motion. Qualitatively, subjects reported new feelings of ownership of their impaired limb, more

  3. Embryo transfer and sex determination following superovulated hinds inseminated with frozen-thawed sex-sorted Y sperm or unsorted semen in Wapiti (Cervus elaphus songaricus).

    PubMed

    Gao, Q H; Wang, H E; Zeng, W B; Wei, H J; Han, C M; Du, H Z; Zhang, Z G; Li, X M

    2011-07-01

    The aim of this study was to evaluate embryo production in superovulated wapiti hinds inseminated with either Y-sorted or unsorted semen. Eighteen hinds were allocated to three treatment groups: AI following multiple ovulation (CIDR/FSH) with 10×10(6) Y-sorted frozen-thawed semen (Y group, n=6), or 10×10(6) and 100×10(6) unsorted frozen-thawed semen for the unsorted (n=6) and the control group (n=6). The embryos from the sixth day following insemination were collected and classified. Fifteen embryos from the unsorted or the control group, and four embryos from the Y group were sex determinated based on DNA analysis of the amelogenin gene. Twenty-one embryos from the Y group and 42 embryos from the unsorted or the control group were transferred into 21 and 42 synchronized recipients via standard procedures on 6th day post estrus, respectively. There were no significant differences in the number of recovered eggs, transferable embryos, degenerated embryos or unfertilized oocytes per hind among the three groups of the control (9.2±3.6, 4.7±1.9, 3.0±2.0, 1.5±1.4), the unsorted (8.2±1.9, 4.8±0.7, 1.7±1.0, 1.7±1.0) and the Y group (8.8±4.2, 4.2±1.8, 2.2±1.2, 2.5±2.1), respectively (P>0.05). The sex ratio of embryos from the Y group (4M/0F) was significantly (P<0.05) distinct from that of the unsorted and control group (8M/7F). The sex ratio of the offspring from sexed embryos (8M/0F) was deviated significantly (P<0.05) from that of the non-sexed embryos (11M/9F). In conclusion, the results suggested that the male embryos of predicted sex can be achieved with AI of sex-sorted cryopreserved sperm. PCR amplification using the amelogenin gene primers can be applied to DNA analysis of micro samples from wapiti embryo biopsies for sex identification. The male offspring can be produced after transferred with the male embryos of predicted sex.

  4. The making of differences between fins and limbs

    PubMed Central

    Yano, Tohru; Tamura, Koji

    2013-01-01

    ‘Evo-devo’, an interdisciplinary field based on developmental biology, includes studies on the evolutionary processes leading to organ morphologies and functions. One fascinating theme in evo-devo is how fish fins evolved into tetrapod limbs. Studies by many scientists, including geneticists, mathematical biologists, and paleontologists, have led to the idea that fins and limbs are homologous organs; now it is the job of developmental biologists to integrate these data into a reliable scenario for the mechanism of fin-to-limb evolution. Here, we describe the fin-to-limb transition based on key recent developmental studies from various research fields that describe mechanisms that may underlie the development of fins, limb-like fins, and limbs. PMID:23256837

  5. Selection and control of limb posture for stability.

    PubMed

    Franklin, David W; Selen, Luc P J; Franklin, Sae; Wolpert, Daniel M

    2013-01-01

    Impedance control can be used to stabilize the limb against both instability and unpredictable perturbations. Limb posture influences motor noise, energy usage and limb impedance as well as their interaction. Here we examine whether subjects use limb posture as part of a mechanism to regulate limb stability. Subjects performed stabilization tasks while attached to a two dimensional robotic manipulandum which generated a virtual environment. Subjects were instructed that they could perform the stabilization task anywhere in the workspace, while the chosen postures were tracked as subjects repeated the task. In order to investigate the mechanisms behind the chosen limb postures, simulations of the neuro-mechanical system were performed. The results indicate that posture selection is performed to provide energy efficiency in the presence of force variability.

  6. Exploring the fine structure at the limb in coronal holes

    NASA Technical Reports Server (NTRS)

    Karovska, Magarita; Blundell, Solon F.; Habbal, Shadia Rifai

    1994-01-01

    The fine structure of the solar limb in coronal holes is explored at temperatures ranging from 10(exp 4) to 10(exp 6) K. An image enhancement algorithm orignally developed for solar eclipse observations is applied to a number of simultaneous multiwavelength observations made with the Harvard Extreme Ultraviolet Spectrometer experiment on Skylab. The enhanced images reveal the presence of filamentary structures above the limb with a characteristic separation of approximately 10 to 15 sec . Some of the structures extend from the solar limb into the corona to at least 4 min above the solar limb. The brightness of these structures changes as a function of height above the limb. The brightest emission is associated with spiculelike structures in the proximity of the limb. The emission characteristic of high-temperature plasma is not cospatial with the emission at lower temperatures, indicating the presence of different temperature plasmas in the field of view.

  7. Experiment M411: Two color earth limb photography

    NASA Technical Reports Server (NTRS)

    Petersen, M.

    1971-01-01

    Some simple calculations were made regarding the scattered light phenomenon of a sunlit earth limb. It was assumed that the light was to be scattered by an atmosphere irradiated by a zenith sun. Calculations were made with several different scattering coefficients assignable to various wavelengths of the extended visual region. The dependence of the excess blue-limb elevation was less obviously determined by the scattering angle than was suspected. It is reasonable to surmise that the variation of the values of excess blue-limb elevation originated principally from the red-limb variance, because the form of the blue-limb profiles (at least in their upper part) was more regular than was that of the red-limb profiles.

  8. Progressive specification rather than intercalation of segments during limb regeneration.

    PubMed

    Roensch, Kathleen; Tazaki, Akira; Chara, Osvaldo; Tanaka, Elly M

    2013-12-13

    An amputated salamander limb regenerates the correct number of segments. Models explaining limb regeneration were largely distinct from those for limb development, despite the presence of common patterning molecules. Intercalation has been an important concept to explain salamander limb regeneration, but clear evidence supporting or refuting this model was lacking. In the intercalation model, the first blastema cells acquire fingertip identity, creating a gap in positional identity that triggers regeneration of the intervening region from the stump. We used HOXA protein analysis and transplantation assays to show that axolotl limb blastema cells acquire positional identity in a proximal-to-distal sequence. Therefore, intercalation is not the primary mechanism for segment formation during limb regeneration in this animal. Patterning in development and regeneration uses similar mechanisms.

  9. Progressive limb ataxia following inferior olive lesions

    PubMed Central

    Horn, K M; Deep, A; Gibson, A R

    2013-01-01

    Cerebellar climbing fibres originate in the inferior olive (IO). Temporary IO inactivation produces movement deficits. Does permanent inactivation produce similar deficits and, if so, do they recover? The excitotoxin, kainic acid, was injected into the rostral IO of three cats. Behaviour was measured during reaching and locomotion. Two cats were injected during the reaching task. Within minutes, grasping became difficult and the trajectories of the reaches showed higher arcing than normally seen. During locomotion, both cats showed head and trunk deviation to the injected side, walking paths curved to the injected side, and the paws were lifted higher than normal. Limbs contralateral to the injections became rigid. Within 1 day, posture had normalized, locomotion was unsteady and high lifting of the paws had reversed to a tendency to drag the dorsum of the paws. Passive body movement produced vestibular signs. Over a few days, locomotion normalized and vestibular signs disappeared. Reach trajectories were normal but grasping deficits persisted. Over the first week, the amplitude of limb lift during reaching and locomotion began to increase. The increase continued over time and, after several months, limb movements became severely ataxic. The effects followed the somatotopy of the rostral IO: a loss of cells in medial rostral IO only affected the forelimb, whereas a loss of cells in medial and lateral IO affected both forelimb and hindlimb. Deficits produced by IO lesions involve multiple mechanisms; some recover rapidly, some appear stable, and some worsen over time. The nature of the progressive deficit suggests a gradual loss of Purkinje cell inhibition on cerebellar nuclear cells. PMID:23027819

  10. Limb Lengthening in Patients with Achondroplasia

    PubMed Central

    Park, Kwang-Won; Garcia, Rey-an Niño; Rejuso, Chastity Amor; Choi, Jung-Woo

    2015-01-01

    Purpose Although bilateral lower-limb lengthening has been performed on patients with achondroplasia, the outcomes for the tibia and femur in terms of radiographic parameters, clinical results, and complications have not been compared with each other. We proposed 1) to compare the radiological outcomes of femoral and tibial lengthening and 2) to investigate the differences of complications related to lengthening. Materials and Methods We retrospectively reviewed 28 patients (average age, 14 years 4 months) with achondroplasia who underwent bilateral limb lengthening between 2004 and 2012. All patients first underwent bilateral tibial lengthening, and at 9-48 months (average, 17.8 months) after this procedure, bilateral femoral lengthening was performed. We analyzed the pixel value ratio (PVR) and characteristics of the callus of the lengthened area on serial radiographs. The external fixation index (EFI) and healing index (HI) were computed to compare tibial and femoral lengthening. The complications related to lengthening were assessed. Results The average gain in length was 8.4 cm for the femur and 9.8 cm for the tibia. The PVR, EFI, and HI of the tibia were significantly better than those of the femur. Fewer complications were found during the lengthening of the tibia than during the lengthening of the femur. Conclusion Tibial lengthening had a significantly lower complication rate and a higher callus formation rate than femoral lengthening. Our findings suggest that bilateral limb lengthening (tibia, followed by femur) remains a reasonable option; however, we should be more cautious when performing femoral lengthening in selected patients. PMID:26446651

  11. Lower limb lengthening in turner dwarfism.

    PubMed

    Hahn, Soo Bong; Park, Hui Wan; Park, Hong Jun; Seo, Young Jin; Kim, Hyun Woo

    2003-06-30

    The aim of this study was to review our cases of lower limb lengthening to treat Turner dwarfism, and to speculate whether or not effective limb lengthening can be achieved in this rare condition. Twelve tibiae and 2 femora were lengthened in 6 patients using the Ilizarov method for the tibia and a gradual elongation nail for the femur. The mean age at the time of surgery was 19 years, and the patients were followed up for a minimum of 2 years. The average gain in the tibial and femoral length was 6.2 cm and 6.0 cm, respectively. The average healing index of tibia and femur was 1.9 and 1.7 months. The average tibia-to-femur ratio improved from 0.68 preoperatively to 0.81 postoperatively, and leg-trunk ratios improved from 0.88 to 0.99. Seven segments (50.0 percent) had completed the lengthening protocol without complications. Two segments (14.3 percent) had an intractable pin site infection requiring a pin exchange, and four segments (35.7 percent) had twelve complications (a nonunion at the distraction site, premature consolidation, Achilles tendon contractures and planovalgus). The overall rate of complications was 100 percent for each bone lengthened. All the patients showing a nonunion at the distraction site had a reduced bone mass, which was less than 65 percent of those of the age-matched normal population. Despite the complications, all patients were satisfied with the results, and lower limb lengthening in Turner Dwarfism believed to be a valid option. However, it may require careful management in a specialist unit in order to prevent complications during the lengthening procedure. In addition, the osteopenia associated with an estrogen deficiency leading to problems in consolidation is a difficult issue to address.

  12. LCD3: Three-parameter limb darkening coefficient sampling

    NASA Astrophysics Data System (ADS)

    Kipping, David M.

    2015-11-01

    LDC3 samples physically permissible limb darkening coefficients for the Sing et al. (2009) three-parameter law. It defines the physically permissible intensity profile as being everywhere-positive, monotonically decreasing from center to limb and having a curl at the limb. The approximate sampling method is analytic and thus very fast, reproducing physically permissible samples in 97.3% of random draws (high validity) and encompassing 94.4% of the physically permissible parameter volume (high completeness).

  13. Morphological integration versus ecological plasticity in the avian pelvic limb skeleton.

    PubMed

    Stoessel, Alexander; Kilbourne, Brandon M; Fischer, Martin S

    2013-05-01

    Understanding patterns and distributions of morphological traits is essential for discerning underpinning processes of morphological variation. We report on the variation in the avian pelvic limb skeleton. Length and width variables were measured in the skeletons of 236 avian species in order to examine the importance of body mass, ecological factors, phylogeny and integration in the formation of specific hindlimb morphology. Scaling relationships with body mass were analyzed across Aves and in individual avian subclades. Principal component analysis and multiple regressions were performed to examine the relationship between morphology, ecology, and phylogeny. Finally, the occurrence of within-limb morphological integration was tested by partial correlation analysis of the residuals from element lengths vs. body mass and correlation analysis of avian hindlimb proportions. Body mass is the greatest contributor to variation, and it strongly influences variation in avian skeletal lengths. Lengthening of the leg typically comes from disproportionate increases in tibiotarsal and tarsometatarsal length. Partial correlation analysis showed that only these two elements are distinctly integrated consistently across all bird taxa, whereas relation of femur and third toe to other limb elements displays no clear pattern. Hence, morphological integration of all elements is not a prerequisite for limb design, and variation between taxa is mainly to be found in femoral and digital length. Furthermore, variation in tibiotarsal relative length is much lower than in other elements likely due to geometric constrains. Clear ecological adaptations are obscured by multifunctionality of the avian hindlimb, and phylogeny significantly constrains the morphology. Finally, when looking at relative lengths segmented limbs meet the requirements of many-to-one-mapping of phenotype to functional property, in line with a common concept of evolvability of function and morphology.

  14. Powered lower limb orthoses for gait rehabilitation

    PubMed Central

    Ferris, Daniel P.; Sawicki, Gregory S.; Domingo, Antoinette

    2006-01-01

    Bodyweight supported treadmill training has become a prominent gait rehabilitation method in leading rehabilitation centers. This type of locomotor training has many functional benefits but the labor costs are considerable. To reduce therapist effort, several groups have developed large robotic devices for assisting treadmill stepping. A complementary approach that has not been adequately explored is to use powered lower limb orthoses for locomotor training. Recent advances in robotic technology have made lightweight powered orthoses feasible and practical. An advantage to using powered orthoses as rehabilitation aids is they allow practice starting, turning, stopping, and avoiding obstacles during overground walking. PMID:16568153

  15. Analysis of a Limb Eruptive Event

    NASA Astrophysics Data System (ADS)

    Kotrč, P. Kupryakov, Yu. A.; Bárta, M.; Kashapova, K., L.; Liu, W.

    2016-04-01

    We present the analysis of an eruptive event that took place on the eastern limb on April 21, 2015, which was observed by the Ondřejov horizontal telescope and spectrograph. The eruption of the highly twisted prominence was followed by the onset of soft X-ray sources. We identified the structures observed in Hα spectra with the details on the Hα filtergrams and analyzed the evolution of Doppler component velocities. The timing and observed characteristics of the eruption were compared with the prediction of the model based on the twisting of the flux ropes and the kink/torus instability.

  16. Compressive neuropathy in the upper limb

    PubMed Central

    Thatte, Mukund R.; Mansukhani, Khushnuma A.

    2011-01-01

    Entrampment neuropathy or compression neuropathy is a fairly common problem in the upper limb. Carpal tunnel syndrome is the commonest, followed by Cubital tunnel compression or Ulnar Neuropathy at Elbow. There are rarer entities like supinator syndrome and pronator syndrome affecting the Radial and Median nerves respectively. This article seeks to review comprehensively the pathophysiology, Anatomy and treatment of these conditions in a way that is intended for the practicing Hand Surgeon as well as postgraduates in training. It is generally a rewarding exercise to treat these conditions because they generally do well after corrective surgery. Diagnostic guidelines, treatment protocols and surgical technique has been discussed. PMID:22022039

  17. ATHLETE: A Limbed Vehicle for Solar System Exploration

    NASA Technical Reports Server (NTRS)

    Wilcox, Brian H.

    2012-01-01

    As part of the Human-Robot Systems project funded by NASA, the Jet Propulsion Laboratory has developed a vehicle called ATHLETE: the All-Terrain Hex-Limbed Extra-Terrestrial Explorer. Each vehicle is based on six wheels at the ends of six multi-degree-of-freedom limbs. Because each limb has enough degrees of freedom for use as a general-purpose leg, the wheels can be locked and used as feet to walk out of excessively soft or other extreme terrain. Since the vehicle has this alternative mode of traversing through or at least out of extreme terrain, the wheels and wheel actuators can be sized for nominal terrain. There are substantial mass savings in the wheel and wheel actuators associated with designing for nominal instead of extreme terrain. These mass savings are comparable-to or larger-than the extra mass associated with the articulated limbs. As a result, the entire mobility system, including wheels and limbs, can be about 25% lighter than a conventional mobility chassis. A side benefit of this approach is that each limb has sufficient degrees-of-freedom to use as a general-purpose manipulator (hence the name "limb" instead of "leg"). Our prototype ATHLETE vehicles have quick-disconnect tool adapters on the limbs that allow tools to be drawn out of a "tool belt" and maneuvered by the limb.

  18. Classic limb patterning models and the work of Dennis Summerbell.

    PubMed

    Galloway, Jenna L; Tabin, Clifford J

    2008-08-01

    Dennis Summerbell was a leading contributor to our understanding of limb patterning prior to the advent of molecular biology. He published several groundbreaking papers, including one that developed a key model for patterning the limb from the shoulder to the fingertips and another that presented the co-discovery of the effect of retinoids on limb morphogenesis. He brought detailed quantitative analyses to bear on these studies, as highlighted in two of his insightful papers published in the Journal of Embryology and Experimental Morphology, in which he provided elegant models that, today, remain relevant to limb patterning, as well as to many disciplines of developmental biology.

  19. Fundamental ratios and logarithmic periodicity in human limb bones.

    PubMed

    Pietak, Alexis; Ma, Siyan; Beck, Caroline W; Stringer, Mark D

    2013-05-01

    Fundamental mathematical relationships are widespread in biology yet there is little information on this topic with regard to human limb bone lengths and none related to human limb bone volumes. Forty-six sets of ipsilateral upper and lower limb long bones and third digit short bones were imaged by computed tomography. Maximum bone lengths were measured manually and individual bone volumes calculated from computed tomography images using a stereologic method. Length ratios of femur : tibia and humerus : ulna were remarkably similar (1.21 and 1.22, respectively) and varied little (<7%) between individuals. The volume ratio of femur : tibia was approximately half that of humerus : ulna (1.58 and 3.28, respectively; P < 0.0001). Lower limb bone volume ratios varied much more than upper limb ratios. The relationship between bone length and volume was found to be well described by power laws, with R(2) values ranging from 0.983 to 0.995. The most striking finding was a logarithmic periodicity in bone length moving from distal to proximal up the limb (upper limb λ = 0.72, lower limb λ = 0.93). These novel data suggest that human limb bone lengths and volumes follow fundamental and highly conserved mathematical relationships, which may contribute to our understanding of normal and disordered growth, stature estimation, and biomechanics.

  20. Telescope beam-profile diagnostics and the solar limb

    NASA Technical Reports Server (NTRS)

    Lindsey, Charles A.; Roellig, Thomas L.

    1991-01-01

    The basic method is described for determining the solar limb brightness profile properly corrected for spurious limb darkening caused by the far wings of the resolving beams encountered in large far-infrared and radio telescopes. When the far wings of the beam can be independently measured this problem is usually amenable to standard deconvolution procedures. Under a broad range of well-defined cases, solutions to the deconvolution problem are unique to within the discrimination provided by the core of the beam profile. The theory is applied to solar limb scans made recently on the James Clerk Maxwell Telscope to show solar limb brightening in 850 micron radiation.

  1. Telescope beam-profile diagnostics and the solar limb

    SciTech Connect

    Lindsey, C.A.; Roellig, T.L. NASA, Ames Research Center, Moffett Field, CA )

    1991-07-01

    The basic method is described for determining the solar limb brightness profile properly corrected for spurious limb darkening caused by the far wings of the resolving beams encountered in large far-infrared and radio telescopes. When the far wings of the beam can be independently measured this problem is usually amenable to standard deconvolution procedures. Under a broad range of well-defined cases, solutions to the deconvolution problem are unique to within the discrimination provided by the core of the beam profile. The theory is applied to solar limb scans made recently on the James Clerk Maxwell Telscope to show solar limb brightening in 850 micron radiation. 16 refs.

  2. Alien limb syndrome secondary to multimodal treatment of recurrent oligodendroglioma.

    PubMed

    Gallant, Rachel E; Bonney, Phillip A; Sughrue, Michael E; Bharucha, Kersi J; Battiste, James D

    2015-10-01

    We present a 41-year-old man who experienced alien limb syndrome as a complication of treatment for recurrent Grade III oligodendroglioma of the right parietal lobe. Alien limb syndrome is a rare phenomenon in which a limb performs involuntary actions and the affected individual feels a sense of estrangement towards the limb. It occurs most commonly as a result of corticobasal syndrome, though a variety of other etiologies have been reported. It is rarely associated with focal lesions, such as stroke or tumors.

  3. Fundamental ratios and logarithmic periodicity in human limb bones

    PubMed Central

    Pietak, Alexis; Ma, Siyan; Beck, Caroline W; Stringer, Mark D

    2013-01-01

    Fundamental mathematical relationships are widespread in biology yet there is little information on this topic with regard to human limb bone lengths and none related to human limb bone volumes. Forty-six sets of ipsilateral upper and lower limb long bones and third digit short bones were imaged by computed tomography. Maximum bone lengths were measured manually and individual bone volumes calculated from computed tomography images using a stereologic method. Length ratios of femur : tibia and humerus : ulna were remarkably similar (1.21 and 1.22, respectively) and varied little (<7%) between individuals. The volume ratio of femur : tibia was approximately half that of humerus : ulna (1.58 and 3.28, respectively; P < 0.0001). Lower limb bone volume ratios varied much more than upper limb ratios. The relationship between bone length and volume was found to be well described by power laws, with R2 values ranging from 0.983 to 0.995. The most striking finding was a logarithmic periodicity in bone length moving from distal to proximal up the limb (upper limb λ = 0.72, lower limb λ = 0.93). These novel data suggest that human limb bone lengths and volumes follow fundamental and highly conserved mathematical relationships, which may contribute to our understanding of normal and disordered growth, stature estimation, and biomechanics. PMID:23521756

  4. Prenatal imaging of distal limb abnormalities using OCT in mice

    NASA Astrophysics Data System (ADS)

    Larina, Irina V.; Syed, Saba H.; Dickinson, Mary E.; Overbeek, Paul; Larin, Kirill V.

    2012-01-01

    Congenital abnormalities of the limbs are common birth defects. These include missing or extra fingers or toes, abnormal limb length, and abnormalities in patterning of bones, cartilage or muscles. Optical Coherence Tomography (OCT) is a 3-D imaging modality, which can produce high-resolution (~8 μm) images of developing embryos with an imaging depth of a few millimeters. Here we demonstrate the capability of OCT to perform 3D imaging of limb development in normal embryos and a mouse model with congenital abnormalities. Our results suggest that OCT is a promising tool to analyze embryonic limb development in mammalian models of congenital defects.

  5. Crash simulation of lower limb with motorcycle basket.

    PubMed

    How, C K; Megat Ahmad, M M; Radin Umar, R S; Hamouda, A M; Harwant, S

    2001-03-01

    Lower limb injuries are the main cause of temporary and permanent disability among motorcyclists in Malaysia. They cause non-fatal but serious injuries requiring hospitalisation. Detailed studies on factors influencing lower limb injuries are justified in an attempt to reduce the occurrence of these injuries. This study presents a computer simulation of the crash behaviour of the basket of a small-engined motorcycle with the lower limb using finite element (FE) methods. The results suggest that the extensive deformation of the motorcycle basket may reduce the risk of injury to the lower limb. The behaviour of the basket during collision is analogous to the crumple zone of automobiles.

  6. Application of sonic hedgehog to the developing chick limb.

    PubMed

    Tiecke, Eva; Tickle, Cheryll

    2007-01-01

    Here, we describe methods for applying Sonic hedgehog (Shh) to developing chick limbs. The Sonic hedgehog gene is expressed in the polarizing region, a signaling region at the posterior margin of the limb bud and application of Shh-expressing cells or Shh protein to early limb buds mimics polarizing region signaling. The polarizing region (or zone of polarizing activity) is involved in one of the best known cell-cell interactions in vertebrate embryos and is pivotal in controlling digit number and pattern. At later stages of limb development, the application of Shh protein to the regions between digit primordia can induce changes in digit morphogenesis.

  7. Physical Map of the Channel Catfish Virus Genome: Location of Sites for Restriction Endonucleases EcoRI, HindIII, HpaI, and XbaI

    PubMed Central

    Chousterman, Suzanne; Lacasa, Michel; Sheldrick, Peter

    1979-01-01

    The overall arrangement of nucleotide sequences in the DNA of channel catfish virus has been studied by cleavage with four restriction endonucleases. Physical maps have been developed for the location of sites for EcoRI, HindIII, HpaI, and XbaI. The sum of the molecular weights of fragments generated by each restriction enzyme indicates a molecular weight of approximately 86 × 106 for the channel catfish virus genome. Fragments corresponding to the molecular ends of channel catfish virus DNA have been identified by their sensitivity to exonuclease treatment. The distribution of restriction sites in the genome shows that sequences included in a 12 × 106-molecular weight region at one end are repeated with direct polarity at the other end, and that the overall genomic sequence order is nonpermuted. Images PMID:16789182

  8. The hind wing of the desert locust (Schistocerca gregaria Forskål). III. A finite element analysis of a deployable structure.

    PubMed

    Herbert, R C; Young, P G; Smith, C W; Wootton, R J; Evans, K E

    2000-10-01

    Finite element analysis is used to model the automatic cambering of the locust hind wing during promotion: the umbrella effect. It was found that the model required a high degree of sophistication before replicating the deformations found in vivo. The model has been validated using experimental data and the deformations recorded both in vivo and ex vivo. It predicts that even slight modifications to the geometrical description used can lead to significant changes in the deformations observed in the anal fan. The model agrees with experimental data and produces deformations very close to those seen in free-flying locusts. The validated model may be used to investigate the varying geometries found in orthopteran anal fans and the stresses found throughout the wing when loaded.

  9. A 405-kb cosmid contig and HindIII restriction map of the progressive myoclonus epilepsy type 1 (EPM1) candidate region in 21q22.3

    SciTech Connect

    Lafreniere, R.G.; Rouleau, G.A.; De Jong, P.J.

    1995-09-01

    As a step toward identifying the molecular defect in patients afflicted with progressive myoclonus epilepsy type 1 (EPM1), we have assembled a cosmid contig of the candidate EPM1 region in 21q22.3. The contig constitutes a collection of 87 different cosmids spanning 405 kb based on a derived HindIII restriction map. Potential CpG-rich islands have been identified based on the