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Sample records for striated shieldbug graphosoma

  1. OBLIQUELY STRIATED MUSCLE

    PubMed Central

    Rosenbluth, Jack

    1967-01-01

    Segments of the obliquely striated body muscle of Ascaris were fixed at minimum body length after treatment with acetylcholine and at maximum body length after treatment with piperazine citrate and then studied by light and electron microscopy. Evidence was found for two mechanisms of length change: sliding of thin filaments with respect to thick filaments such as occurs in cross-striated muscle, and shearing of thick filaments with respect to each other such that the degree of their stagger increases with extension and decreases with shortening. The shearing mechanism could account for great extensibility in this muscle and in nonstriated muscles in general and could underlie other manifestations of "plasticity" as well. In addition, it is suggested that the contractile apparatus is attached to the endomysium in such a way that the sarcomeres can act either in series, as in cross-striated muscle, or individually. Since the sarcomeres are virtually longitudinal in orientation and are almost coextensive with the muscle fiber, it would, therefore, be possible for a single sarcomere contracting independently to develop tension effectively between widely separated points on the fiber surface, thus permitting very efficient maintenance of isometric tension. PMID:6040534

  2. Striated morphology during electrodeposition

    SciTech Connect

    Jorne, J.; Lee, M.G.

    1996-03-01

    Comparative study of striated morphologies obtained during the electrodeposition of various metals is performed using rotating electrodes. The formation of striation during electrodeposition of zinc, copper, and silver follows the streamlines of the fluid, and is observed to be accompanied by small or negative polarization resistance. The spacings between striae depends strongly on the applied current density. The spacing decreases with current density in the case of zinc and silver, however, a reverse trend is observed in the case of copper. Linear stability analysis shows that spatial multiplicity occurs when ({partial_derivative}i/{partial_derivative}C){sub {eta}} < 0. The experimentally observed spacings between striae (0.1 {approximately} 1 mm) are in agreement with the wavelength obtained from the linear stability analysis. The analysis of polarization and striation data shows fairly good qualitative agreement with respect to the effects of current density, diffusion layer thickness, and electrolyte concentration on striation.

  3. Ophthalmic striated muscle neoplasms.

    PubMed

    Knowles, D M; Jakobiec, F A; Potter, G D; Jones, I S

    1976-01-01

    Rhabdomyosarcoma, the most common primary malignant childhood orbital tumor, is composed of neoplastic striated muscle cells (rhabdomyoblasts) in various stages of differentiation and in patterns suggestive of neoplastic analogs of normal muscle embryogenesis. Orbital rhabdomyosarcoma is most commonly seen in children and adolescents, the average age of onset of symptoms being 7.8 years. The tumor usually presents as a rapidly evolving exophthalmos, often associated with drooping of the upper eyelid. A mass is palapable in only 25% of cases, loss of central vision at the time of presentation is uncommon, and laboratory studies are often of little help in diagnosis. The best diagnostic aid is a high index of suspicion whenever one sees a rapidly progressive exophthalamos in a child. Orbital rhabdomyosarcoma is almost always of the embryonal type, believed to originate in the orbital soft tissues from undifferentiated pluripotential embryonic mesenchyme. In the past, orbital exenteration has been the primary therapy. Review of 162 literature cases of orbital rhabdomyosarcoma, generally treated by unassisted surgery, revealed that only 25% of the patients survived 3 or more years. Recently, it has been shown that radiation therapy, alone or combined with chemotherapy, can be successful. A multidisciplinary approach, utilizing surgery, radiation therapy and chemotherapy has also been advocated. Both approaches appear to offer greater survival than unassisted orbital exenteration. The possibility of primary radiation therapy is extremely promising; if it becomes increasingly effective, a mutilating surgical procedure may become obsolete.

  4. Gammaproteobacteria as essential primary symbionts in the striped shield bug, Graphosoma Lineatum (Hemiptera: Pentatomidae)

    PubMed Central

    Karamipour, Naeime; Mehrabadi, Mohammad; Fathipour, Yaghoub

    2016-01-01

    Many members of suborder Heteroptra harbor heritable symbiotic bacteria. Here we characterize the gut symbiotic bacterium in Graphosoma lineatum (Hemiptera: Pentatomidae) by using molecular phylogeny, real-time PCR analysis as well as light and electron microscopy observations. The microscopy observations revealed the presence of a large number of rod-shaped bacterial cells in the crypts. A very high prevalence (98 to 100%) of the symbiont infection was found in the insect populations that strongly supports an intimate association between these two organisms. Real-time PCR analysis also showed that the Gammaproteobacteria dominated the crypts. The sequences of 16sr RNA and groEL genes of symbiont showed high levels of similarity (93 to 95%) to Pantoea agglomeranse and Erwinia herbicola Gammaproteobacteria. Phylogenetic analyses placed G. lineatum symbiont in a well-defined branch, divergent from other stink bug bacterial symbionts. Co-evolutionary analysis showed lack of host-symbiont phylogenetic congruence. Surface sterilization of eggs resulted in increased pre-adult stage in the offspring (aposymbionts) in comparison to the normal. Also, fecundity, longevity, and adult stage were significantly decreased in the aposymbionts. Therefore, it seems that the symbiont might play a vital function in the host biology, in which host optimal development depends on the symbiont. PMID:27609055

  5. Gammaproteobacteria as essential primary symbionts in the striped shield bug, Graphosoma Lineatum (Hemiptera: Pentatomidae).

    PubMed

    Karamipour, Naeime; Mehrabadi, Mohammad; Fathipour, Yaghoub

    2016-01-01

    Many members of suborder Heteroptra harbor heritable symbiotic bacteria. Here we characterize the gut symbiotic bacterium in Graphosoma lineatum (Hemiptera: Pentatomidae) by using molecular phylogeny, real-time PCR analysis as well as light and electron microscopy observations. The microscopy observations revealed the presence of a large number of rod-shaped bacterial cells in the crypts. A very high prevalence (98 to 100%) of the symbiont infection was found in the insect populations that strongly supports an intimate association between these two organisms. Real-time PCR analysis also showed that the Gammaproteobacteria dominated the crypts. The sequences of 16sr RNA and groEL genes of symbiont showed high levels of similarity (93 to 95%) to Pantoea agglomeranse and Erwinia herbicola Gammaproteobacteria. Phylogenetic analyses placed G. lineatum symbiont in a well-defined branch, divergent from other stink bug bacterial symbionts. Co-evolutionary analysis showed lack of host-symbiont phylogenetic congruence. Surface sterilization of eggs resulted in increased pre-adult stage in the offspring (aposymbionts) in comparison to the normal. Also, fecundity, longevity, and adult stage were significantly decreased in the aposymbionts. Therefore, it seems that the symbiont might play a vital function in the host biology, in which host optimal development depends on the symbiont. PMID:27609055

  6. Reactions of green lizards (Lacerta viridis) to major repellent compounds secreted by Graphosoma lineatum (Heteroptera: Pentatomidae).

    PubMed

    Gregorovičová, Martina; Černíková, Alena

    2015-06-01

    The chemical defence of Heteroptera is primarily based on repellent secretions which signal the potential toxicity of the bug to its predators. We tested the aversive reactions of green lizards (Lacerta viridis) towards the major compounds of the defensive secretion of Graphosoma lineatum, specifically: (i) a mixture of three aldehydes: (E)-hex-2-enal, (E)-oct-2-enal, (E)-dec-2-enal; (ii) a mixture of these three aldehydes and tridecane; (iii) oxoaldehyde: (E)-4-oxohex-2-enal; (iv) secretion extracted from metathoracic scent glands of G. lineatum adults and (v) hexane as a non-polar solvent. All chemicals were presented on a palatable food (Tenebrio molitor larvae). The aversive reactions of the green lizards towards the mealworms were evaluated by observing the approach latencies, attack latencies and approach-attack intervals. The green lizards exhibited a strong aversive reaction to the mixture of three aldehydes. Tridecane reduced the aversive reaction to the aldehyde mixture. Oxoaldehyde caused the weakest, but still significant, aversive reaction. The secretion from whole metathoracic scent glands also clearly had an aversive effect on the green lizards. Moreover, when a living specimen of G. lineatum or Pyrrhocoris apterus (another aposematic red-and-black prey) was presented to the green lizards before the trials with the aldehyde mixture, the aversive effect of the mixture was enhanced. In conclusion, the mixture of three aldehydes had the strong aversive effect and could signal the potential toxicity of G. lineatum to the green lizards. PMID:25869384

  7. Titin: major myofibrillar components of striated muscle.

    PubMed Central

    Wang, K; McClure, J; Tu, A

    1979-01-01

    Electrophoretic analyses of protein components of striated muscle myofibril purified from various vertebrate and invertebrate species revealed that proteins much larger than myosin heavy chain are present in significant amounts. To define possible roles of these heretofore unidentified proteins, we purified a combination of two uncommonly large proteins, designated as titin, from chicken breast myofibrils. Chemical and immunological studies indicated that titin is distinct from myosin, actin, and filamin. Specific titin anti body crossreacts with similar protein in both skeletal and cardiac myofibrils of many vertebrate and invertebrate species. Immunofluorescent staining of glycerinated chicken breast myofibrils indicated that titin is present in M lines, Z lines, the junctions of A and I bands, and perhaps throughout the entire A bands. Similar staining studies of myofibrils from other species suggest that titinlike proteins may be organized in all myofibrils according to a common architectural plan. We conclude that titin is a structurally conserved myofibrillar component of vertebrate and invertebrate striated muscles. Images PMID:291034

  8. Objective forensic analysis of striated, quasi-striated and impressed toolmarks

    NASA Astrophysics Data System (ADS)

    Spotts, Ryan E.

    Following the 1993 Daubert v. Merrell Dow Pharmaceuticals, Inc. court case and continuing to the 2010 National Academy of Sciences report, comparative forensic toolmark examination has received many challenges to its admissibility in court cases and its scientific foundations. Many of these challenges deal with the subjective nature in determining whether toolmarks are identifiable. This questioning of current identification methods has created a demand for objective methods of identification - "objective" implying known error rates and statistically reliability. The demand for objective methods has resulted in research that created a statistical algorithm capable of comparing toolmarks to determine their statistical similarity, and thus the ability to separate matching and nonmatching toolmarks. This was expanded to the creation of virtual toolmarking (characterization of a tool to predict the toolmark it will create). The statistical algorithm, originally designed for two-dimensional striated toolmarks, had been successfully applied to striated screwdriver and quasi-striated plier toolmarks. Following this success, a blind study was conducted to validate the virtual toolmarking capability using striated screwdriver marks created at various angles of incidence. Work was also performed to optimize the statistical algorithm by implementing means to ensure the algorithm operations were constrained to logical comparison regions (e.g. the opposite ends of two toolmarks do not need to be compared because they do not coincide with each other). This work was performed on quasi-striated shear cut marks made with pliers - a previously tested, more difficult application of the statistical algorithm that could demonstrate the difference in results due to optimization. The final research conducted was performed with pseudostriated impression toolmarks made with chisels. Impression marks, which are more complex than striated marks, were analyzed using the algorithm to separate

  9. Independent evolution of striated muscles in cnidarians and bilaterians

    PubMed Central

    Steinmetz, Patrick R.H.; Kraus, Johanna E.M.; Larroux, Claire; U. Hammel, Jörg; Amon-Hassenzahl, Annette; Houliston, Evelyn; Wörheide, Gert; Nickel, Michael; Degnan, Bernard M.; Technau, Ulrich

    2012-01-01

    Striated muscles are present in bilaterian animals (e.g. vertebrates, insects, annelids) and some non-bilaterian eumetazoans (i.e. cnidarians and ctenophores). The striking ultrastructural similarity of striated muscles between these animal groups is thought to reflect a common evolutionary origin1, 2. Here we show that a muscle protein core set, including a Myosin type II Heavy Chain motor protein characteristic of striated muscles in vertebrates (MyHC-st), was already present in unicellular organisms before the origin of multicellular animals. Furthermore, myhc-st and myhc-non-muscle (myhc-nm) orthologues are expressed differentially in two sponges, compatible with the functional diversification of myhc paralogues before the origin of true muscles and the subsequent deployment of MyHC-st in fast-contracting smooth and striated muscle. Cnidarians and ctenophores possess myhc-st orthologues but lack crucial components of bilaterian striated muscles, such as troponin complex and titin genes, suggesting the convergent evolution of striated muscles. Consistently, jellyfish orthologues of a shared set of bilaterian z-disc proteins are not associated with striated muscles, but are instead expressed elsewhere or ubiquitously. The independent evolution of eumetazoan striated muscles through the addition of novel proteins to a pre-existing, ancestral contractile apparatus may serve as a paradigm for the evolution of complex animal cell types. PMID:22763458

  10. Interrelated striated elements in vestibular hair cells of the rat

    NASA Technical Reports Server (NTRS)

    Ross, M. D.; Bourne, C.

    1983-01-01

    A series of interrelated striated organelles in types I and II vestibular hair cells of the rat which appear to be less developed in cochlear hair cells have been revealed by unusual fixation procedures, suggesting that contractile elements may play a role in sensory transduction in the inner ear, especially in the vestibular system. Included in the series of interrelated striated elements are the cuticular plate and its basal attachments to the hair cell margins, the connections of the strut array of the kinociliary basal body to the cuticular plate, and striated organelles associated with the plasma membrane and extending below the apical junctional complexes.

  11. Representation of the visual field in the occipital striate cortex.

    PubMed Central

    McFadzean, R; Brosnahan, D; Hadley, D; Mutlukan, E

    1994-01-01

    The representation of the field of vision in the human striate cortex is based on the Holmes map in which about 25% of the surface area of the striate cortex is allocated to the central 15 degrees of vision. Following the introduction of computed tomography of the brain, the accuracy of the Holmes map was apparently confirmed by clinical/radiological correlation, but a revision has been proposed by Horton and Hoyt based on a magnetic resonance imaging study of three patients with visual field defects due to striate lesions. They propose that the central cortical representation of vision occupies a much larger area. This study reviews the perimetric and imaging findings in a larger series of patients with striate cortical disease and provides support for the revised representation. The clinical phenomenon of macular sparing and its relation to representation of the macula at the occipital pole is also discussed. Images PMID:8148333

  12. Poorly Understood Aspects of Striated Muscle Contraction

    PubMed Central

    Månsson, Alf

    2015-01-01

    Muscle contraction results from cyclic interactions between the contractile proteins myosin and actin, driven by the turnover of adenosine triphosphate (ATP). Despite intense studies, several molecular events in the contraction process are poorly understood, including the relationship between force-generation and phosphate-release in the ATP-turnover. Different aspects of the force-generating transition are reflected in the changes in tension development by muscle cells, myofibrils and single molecules upon changes in temperature, altered phosphate concentration, or length perturbations. It has been notoriously difficult to explain all these events within a given theoretical framework and to unequivocally correlate observed events with the atomic structures of the myosin motor. Other incompletely understood issues include the role of the two heads of myosin II and structural changes in the actin filaments as well as the importance of the three-dimensional order. We here review these issues in relation to controversies regarding basic physiological properties of striated muscle. We also briefly consider actomyosin mutation effects in cardiac and skeletal muscle function and the possibility to treat these defects by drugs. PMID:25961006

  13. Subcellular distribution of potassium in striated muscles

    SciTech Connect

    Edelmann, L.

    1984-01-01

    Microanalytical experiments have been performed to answer the question whether the main cellular cation, K+, follows the water distribution in the striated muscle cell or whether K+ follows the distribution of negative fixed charges (beta- and gamma-carboxyl groups of aspartic and glutamic acid residues). Subcellular localization of K and/or of the K surrogates Rb, Cs, and Tl has been investigated by the following methods: Chemical precipitation of K with tetraphenylborate. Autoradiography of alkali-metals and Tl in air-dried and frozen-hydrated preparations. TEM visualization of electron dense Cs and Tl in sections of freeze-dried and plastic embedded muscle. X-ray microanalysis of air-dried myofibrils and muscle cryosections. The experiments consistently show that K, Rb, Cs, and Tl do not follow the water distribution but are mainly accumulated in the A band, especially in the marginal regions, and at Z lines. The same sites preferentially accumulate Cs or uranyl cations when sections of freeze-dried, embedded muscle are exposed to these electron microscopic stains. It is concluded that the detected uneven distribution of K, Rb, Cs, and Tl in muscle is neither a freeze-drying artifact nor an embedding artifact and may result from a weak ion binding to the beta- and gamma-carboxyl groups of cellular proteins.

  14. An invertebrate smooth muscle with striated muscle myosin filaments

    PubMed Central

    Sulbarán, Guidenn; Alamo, Lorenzo; Pinto, Antonio; Márquez, Gustavo; Méndez, Franklin; Padrón, Raúl; Craig, Roger

    2015-01-01

    Muscle tissues are classically divided into two major types, depending on the presence or absence of striations. In striated muscles, the actin filaments are anchored at Z-lines and the myosin and actin filaments are in register, whereas in smooth muscles, the actin filaments are attached to dense bodies and the myosin and actin filaments are out of register. The structure of the filaments in smooth muscles is also different from that in striated muscles. Here we have studied the structure of myosin filaments from the smooth muscles of the human parasite Schistosoma mansoni. We find, surprisingly, that they are indistinguishable from those in an arthropod striated muscle. This structural similarity is supported by sequence comparison between the schistosome myosin II heavy chain and known striated muscle myosins. In contrast, the actin filaments of schistosomes are similar to those of smooth muscles, lacking troponin-dependent regulation. We conclude that schistosome muscles are hybrids, containing striated muscle-like myosin filaments and smooth muscle-like actin filaments in a smooth muscle architecture. This surprising finding has broad significance for understanding how muscles are built and how they evolved, and challenges the paradigm that smooth and striated muscles always have distinctly different components. PMID:26443857

  15. Dynamic Regulation of Sarcomeric Actin Filaments in Striated Muscle

    PubMed Central

    Ono, Shoichiro

    2010-01-01

    In striated muscle, the actin cytoskeleton is differentiated into myofibrils. Actin and myosin filaments are organized in sarcomeres and specialized for producing contractile forces. Regular arrangement of actin filaments with uniform length and polarity is critical for the contractile function. However, the mechanisms of assembly and maintenance of sarcomeric actin filaments in striated muscle are not completely understood. Live imaging of actin in striated muscle has revealed that actin subunits within sarcomeric actin filaments are dynamically exchanged without altering overall sarcomeric structures. A number of regulators for actin dynamics have been identified, and malfunction of these regulators often result in disorganization of myofibril structures or muscle diseases. Therefore, proper regulation of actin dynamics in striated muscle is critical for assembly and maintenance of functional myofibrils. Recent studies have suggested that both enhancers of actin dynamics and stabilizers of actin filaments are important for sarcomeric actin organization. Further investigation of the regulatory mechanism of actin dynamics in striated muscle should be a key to understanding how myofibrils develop and operate. © 2010 Wiley-Liss, Inc. PMID:20737540

  16. Neurohypophyseal Hormones: Novel Actors of Striated Muscle Development and Homeostasis

    PubMed Central

    Costa, Alessandra; Rossi, Eleonora; Scicchitano, Bianca Maria; Coletti, Dario; Moresi, Viviana

    2014-01-01

    Since the 1980’s, novel functional roles of the neurohypophyseal hormones vasopressin and oxytocin have emerged. Several studies have investigated the effects of these two neurohormones on striated muscle tissues, both in vitro and in vivo. The effects of vasopressin on skeletal myogenic cells, developing muscle and muscle homeostasis have been documented. Oxytocin appears to have a greater influence on cardiomyocite differentiation and heart homeostasis. This review summarizes the studies on these novel roles of the two neurohypophyseal hormones, and open the possibility of new therapeutic approaches for diseases affecting striated muscle. PMID:26913138

  17. Enrichment and terminal differentiation of striated muscle progenitors in vitro

    SciTech Connect

    Becher, Ulrich M.; Breitbach, Martin; Sasse, Philipp; Garbe, Stephan; Ven, Peter F.M. van der; Fuerst, Dieter O.; Fleischmann, Bernd K.

    2009-10-01

    Enrichment and terminal differentiation of mammalian striated muscle cells is severely hampered by fibroblast overgrowth, de-differentiation and/or lack of functional differentiation. Herein we report a new, reproducible and simple method to enrich and terminally differentiate muscle stem cells and progenitors from mice and humans. We show that a single gamma irradiation of muscle cells induces their massive differentiation into structurally and functionally intact myotubes and cardiomyocytes and that these cells can be kept in culture for many weeks. Similar results are also obtained when treating skeletal muscle-derived stem cells and progenitors with Mitomycin C.

  18. Histochemical characteristics of the striated inclusions of adrenoleukodystrophy.

    PubMed

    Johnson, A B; Schaumburg, H H; Powers, J M

    1976-06-01

    The straited accumulations in adrenal cortical cells and brain macrophages that are characteristic of adrenoleukodystrophy have been studied histochemically in cryostat sections to seek leads for the biochemical identification of the striated material. It stained pale pink with oil red O and did not stain with the Schultz cholesterol procedure or periodic acid-Schiff technique. By utilizing the birefringence of the accumulations as a marker, it was determined that, unlike natural cholesterol and cholesterol esters, the striated material was resistant to acetone and ethanol extraction. It was readily soluble, however, in nonpolar solvents such as n-hexane and chloroform. These findings indicated that the material was most probably a lipid, and they suggested that sequential extraction of adrenoleukodystrophy adrenal and brain with acetone and then n-hexane could be used to isolate this material in relatively pure form. Based on this lead, biochemical studies have just revealed a fatty acid abnormality in adrenoleukodystrophy which appears to be unique to this genetic disease.

  19. Virtual and simulated striated toolmarks for forensic applications.

    PubMed

    Baiker, Martin; Petraco, Nicholas D K; Gambino, Carol; Pieterman, René; Shenkin, Peter; Zoon, Peter

    2016-04-01

    Large numbers of experimental toolmarks of screwdrivers are often required in casework of toolmark examiners and in research environments alike, to be able to recover the angle of attack of a crime scene mark and to determine statistically meaningful properties of toolmarks respectively. However, in practice the number of marks is limited by the time needed to create them. In this article, we present an approach to predict how a striated mark of a particular tool would look like, using 3D surface datasets of screwdrivers. We compare these virtual toolmarks qualitatively and quantitatively with real experimental marks in wax and show that they are very similar. In addition we study toolmark similarity, dependent on the angle of attack, with a very high angular resolution of 1°. The results show that for the tested type of screwdriver, our toolmark comparison framework yields known match similarity scores that are above the mean known non-match similarity scores, even for known match differences in angle of attack of up to 40°. In addition we demonstrate an approach to automatically recover the angle of attack of an experimental toolmark and experiments yield high accuracy and precision of 0.618 ± 4.179°. Furthermore, we present a strategy to study the structural elements of striated toolmarks using wavelet analysis, and show how to use the results to simulate realistic toolmarks.

  20. Allergic Interstitial Nephritis Manifesting as a Striated Nephrogram

    PubMed Central

    Moinuddin, Irfan; Bracamonte, Erika; Thajudeen, Bijin; Sussman, Amy; Madhrira, Machaiah; Costello, James

    2015-01-01

    Allergic interstitial nephritis (AIN) is an underdiagnosed cause of acute kidney injury (AKI). Guidelines suggest that AIN should be suspected in a patient who presents with an elevated serum creatinine and a urinalysis that shows white cells, white cell casts, or eosinophiluria. Drug-induced AIN is suspected if AKI is temporally related to the initiation of a new drug. However, patients with bland sediment and normal urinalysis can also have AIN. Currently, a definitive diagnosis of AIN is made by renal biopsy which is invasive and fraught with risks such as bleeding, infection, and hematoma. Additionally, it is frequently unclear when a kidney biopsy should be undertaken. We describe a biopsy proven case of allergic interstitial nephritis which manifested on contrast enhanced Magnetic Resonance Imaging (MRI) as a striated nephrogram. Newer and more stable macrocyclic gadolinium contrast agents have a well-demonstrated safety profile. Additionally, in the presentation of AKI, gadolinium contrast agents are safe to administer in patients who demonstrate good urine output and a downtrending creatinine. We propose that the differential for a striated nephrogram may include AIN. In cases in which the suspicion for AIN is high, this diagnostic consideration may be further characterized by contrast enhanced MRI. PMID:26664405

  1. Topography of Striate-Extrastriate Connections in Neonatally Enucleated Rats

    PubMed Central

    Laing, Robyn J.; Lasiene, Jurate; Olavarria, Jaime F.

    2013-01-01

    It is known that retinal input is necessary for the normal development of striate cortex and its corticocortical connections, but there is little information on the role that retinal input plays in the development of retinotopically organized connections between V1 and surrounding visual areas. In nearly all lateral extrastriate areas, the anatomical and physiological representation of the nasotemporal axis of the visual field mirrors the representation of this axis in V1. To determine whether the mediolateral topography of striate-extrastriate projections is preserved in neonatally enucleated rats, we analyzed the patterns of projections resulting from tracer injections placed at different sites along the mediolateral axis of V1. We found that the correlation between the distance from injection sites to the lateral border of V1 and the distance of the labeling patterns in area 18a was strong in controls and much weaker in enucleates. Data from pairs of injections in the same animal revealed that the separation of area 18a projection fields for a given separation of injection sites was more variable in enucleated than in control rats. Our analysis of single and double tracer injections suggests that neonatal bilateral enucleation weakens, but not completely abolishes, the mediolateral topography in area 18a. PMID:24199194

  2. Theoretical study of interactions between striated cylindrical particles and membrane

    NASA Astrophysics Data System (ADS)

    Wang, Jing-Jing; Jia-Wei, Feng; Ren, Chun-Lai

    2015-08-01

    The interaction of nanoparticles with cell membranes is of great importance because of their potential biomedical applications. In this paper, we investigate the adhesion of stripe-patterned cylinders to a fluid membrane with a full consideration of the Helfrich free energy. Three situations are considered: one striated cylindrical particle, two pure cylindrical particles, and two Janus cylindrical particles. It is found that, with the adhesion of a single sparse striated cylinder, there are a variety of steady-states with energy barriers and the stable state is determined by the pattern of the cylinder. However, when the particle is densely striped, it has no effect on the stable state. By comparing the wrapping degree of two cylindrical particles with that of a single cylindrical particle, we find that two pure cylindrical particles can promote or suppress their interaction with the membrane under different situations. However, two Janus cylindrical particles can only inhibit their interaction with the membrane. Besides, this interaction is related to a first-order transition which is a shallow-to-deep wrapping transition for two pure cylinders while it is a shallow-to-half wrapping transition for two Janus cylinders. Furthermore, the position where the transition happens as a function of adhesion energy is given for fixed membrane tension and the precondition of the transition is presented. Project supported by the National Natural Science Foundation of China (Grant Nos. 91027040 and 21274062).

  3. Weakly nonlinear ion waves in striated electron temperatures.

    PubMed

    Guio, P; Pécseli, H L

    2016-04-01

    The existence of low-frequency waveguide modes of electrostatic ion acoustic waves is demonstrated in magnetized plasmas for cases where the electron temperature is striated along magnetic field lines. For low frequencies, the temperature striation acts as waveguide that supports a trapped mode. For conditions where the ion cyclotron frequency is below the ion plasma frequency we find a dispersion relation having also a radiative frequency band, where waves can escape from the striation. Arguments for the formation and propagation of an equivalent of electrostatic shocks are presented and demonstrated numerically for these conditions. The shock represents here a balance between an external energy input maintained by ion injection and a dissipation mechanism in the form of energy leakage of the harmonics generated by nonlinear wave steepening. This is a reversible form for energy loss that can replace the time-irreversible losses in a standard Burgers equation. PMID:27176415

  4. The Chromatin Remodeling Complex Chd4/NuRD Controls Striated Muscle Identity and Metabolic Homeostasis.

    PubMed

    Gómez-Del Arco, Pablo; Perdiguero, Eusebio; Yunes-Leites, Paula Sofia; Acín-Pérez, Rebeca; Zeini, Miriam; Garcia-Gomez, Antonio; Sreenivasan, Krishnamoorthy; Jiménez-Alcázar, Miguel; Segalés, Jessica; López-Maderuelo, Dolores; Ornés, Beatriz; Jiménez-Borreguero, Luis Jesús; D'Amato, Gaetano; Enshell-Seijffers, David; Morgan, Bruce; Georgopoulos, Katia; Islam, Abul B M M K; Braun, Thomas; de la Pompa, José Luis; Kim, Johnny; Enriquez, José A; Ballestar, Esteban; Muñoz-Cánoves, Pura; Redondo, Juan Miguel

    2016-05-10

    Heart muscle maintains blood circulation, while skeletal muscle powers skeletal movement. Despite having similar myofibrilar sarcomeric structures, these striated muscles differentially express specific sarcomere components to meet their distinct contractile requirements. The mechanism responsible is still unclear. We show here that preservation of the identity of the two striated muscle types depends on epigenetic repression of the alternate lineage gene program by the chromatin remodeling complex Chd4/NuRD. Loss of Chd4 in the heart triggers aberrant expression of the skeletal muscle program, causing severe cardiomyopathy and sudden death. Conversely, genetic depletion of Chd4 in skeletal muscle causes inappropriate expression of cardiac genes and myopathy. In both striated tissues, mitochondrial function was also dependent on the Chd4/NuRD complex. We conclude that an epigenetic mechanism controls cardiac and skeletal muscle structural and metabolic identities and that loss of this regulation leads to hybrid striated muscle tissues incompatible with life.

  5. Striated spectral activity in Jovian and Saturnian radio emission

    NASA Astrophysics Data System (ADS)

    Thieman, James R.; Alexander, Joseph K.; Arias, Tomas A.; Staelin, David H.

    1988-09-01

    Examination of high time resolution frequency-time spectrograms of radio emission measured near the Voyager 1 and 2 encounters with Jupiter reveals occasional striation patterns within the normally diffuse hectometric radiation. The patterns are characterized by distinctive banded structures of enhanced intensity meandering in frequency over time scales of minutes to tens of minutes. This banded form of striated spectral activity (SSA) has an occurrence probability of the order of 5 percent during the three weeks before and after Jupiter encounters. Plots of single 6-s frequency sweeps often exhibit a slow rise in intensity followed by a sharp drop-off in each band as frequency decreases. Banded SSA is often preceded or followed by chaotic SSA in which banding of the emission becomes discontinuous or unrecognizable, although the intensity modulation is still evident. Although SSA normally occurs in the frequency range of roughly 0.2-1.0 MHz, similar but longer-lasting patterns have been found occasionally in decametric emission above 10 MHz. Analogous modulation has also been observed in the Saturnian radio emission, suggesting that SSA may be a common feature intrinsic to the radio emission at both planets.

  6. X-ray Diffraction Studies of Striated Muscles

    SciTech Connect

    Squire, J.M.; Knupp, C.; Roessle, M.; Al-Khayat, H.A.; Irving, T.C.; Eakins, F.; Mok, N.-S.; Harford, J.J.; Reedy, M.K.

    2006-04-24

    In this short review a number of recent X-ray diffraction results on the highly ordered striated muscles in insects and in bony fish have been briefly described. What is clear is that this technique applied to muscles which are amenable to rigorous analysis, taken together with related data from other sources (e.g. protein crystallography, biochemistry, mechanics, computer modelling) can provide not only the best descriptions yet available on the myosin head organisations on different myosin filaments in the relaxed state, but can also show the sequence of molecular events that occurs in the contractile cycle, and may also help to explain such phenomena as stretch-activation. X-ray diffraction is clearly an enormously powerful tool in studies of muscle. It has already provided a wealth of detail on muscle ultrastructure; it is providing ever more fascinating insights into molecular events in the 50-year old sliding filament mechanism, and there remains a great deal more potential that is as yet untapped.

  7. Spatially congruent model for the striate visual cortex

    NASA Astrophysics Data System (ADS)

    da Fontoura Costa, Luciano

    1994-05-01

    A spatially congruent new model for the striate visual cortex (SVC) is proposed which accounts for some of the known functional and organizational properties of the superior mammalian SVC. Even though there is a broad consensus that the topographical representation of the visual field is one of the principal structuring principles underlying the SVC organization, the orientation maps in the SVC have often been described as non-topographical maps. In the present model, the adopted foot-of-normal representation of straight lines has allowed full congruency between the visual field topographic map and the orientation maps in the SVC. The proposed computational model includes three neural layers and assumes that the ocular dominance columns are already established at birth; three possibilities of neural mechanisms leading to orientation encoding are outlined and discussed. The model provides reasonable explanation to some of the most intriguing recently verified properties of the SVC such as the increased neural activity at the cytochrome oxidase blobs, the reduced orientation selectivity at these same places, and the pinwheel-like organization of the orientation selectivity in the SVC.

  8. Neuronal basis of perceptual learning in striate cortex

    PubMed Central

    Ren, Zhen; Zhou, Jiawei; Yao, Zhimo; Wang, Zhengchun; Yuan, Nini; Xu, Guangwei; Wang, Xuan; Zhang, Bing; Hess, Robert F.; Zhou, Yifeng

    2016-01-01

    It is well known that, in humans, contrast sensitivity training at high spatial frequency (SF) not only leads to contrast sensitivity improvement, but also results in an improvement in visual acuity as assessed with gratings (direct effect) or letters (transfer effect). However, the underlying neural mechanisms of this high spatial frequency training improvement remain to be elucidated. In the present study, we examined four properties of neurons in primary visual cortex (area 17) of adult cats that exhibited significantly improved acuity after contrast sensitivity training with a high spatial frequency grating and those of untrained control cats. We found no difference in neuronal contrast sensitivity or tuning width (Width) between the trained and untrained cats. However, the trained cats showed a displacement of the cells’ optimal spatial frequency (OSF) to higher spatial frequencies as well as a larger neuronal signal-to-noise ratio (SNR). Furthermore, both the neuronal differences in OSF and SNR were significantly correlated with the improvement of acuity measured behaviorally. These results suggest that striate neurons might mediate the perceptual learning-induced improvement for high spatial frequency stimuli by an alteration in their spatial frequency representation and by an increased SNR. PMID:27094565

  9. Calcium signaling in insulin action on striated muscle.

    PubMed

    Contreras-Ferrat, A; Lavandero, S; Jaimovich, E; Klip, A

    2014-11-01

    Striated muscles (skeletal and cardiac) are major physiological targets of insulin and this hormone triggers complex signaling pathways regulating cell growth and energy metabolism. Insulin increases glucose uptake into muscle cells by stimulating glucose transporter (GLUT4) translocation from intracellular compartments to the cell surface. The canonical insulin-triggered signaling cascade controlling this process is constituted by well-mapped tyrosine, lipid and serine/threonine phosphorylation reactions. In parallel to these signals, recent findings reveal insulin-dependent Ca(2+) mobilization in skeletal muscle cells and cardiomyocytes. Specifically, insulin activates the sarco-endoplasmic reticulum (SER) channels that release Ca(2+) into the cytosol i.e., the Ryanodine Receptor (RyR) and the inositol 1,4,5-triphosphate receptor (IP3R). In skeletal muscle cells, a rapid, insulin-triggered Ca(2+) release occurs through RyR, that is brought about upon S-glutathionylation of cysteine residues in the channel by reactive oxygen species (ROS) produced by the early activation of the NADPH oxidase (NOX2). In cardiomyocytes insulin induces a fast and transient increase in cytoplasmic [Ca(2+)]i trough L-type Ca(2+) channels activation. In both cell types, a relatively slower Ca(2+) release also occurs through IP3R activation, and is required for GLUT4 translocation and glucose uptake. The insulin-dependent Ca(2+) released from IP3R of skeletal muscle also promotes mitochondrial Ca(2+) uptake. We review here these actions of insulin on intracellular Ca(2+) channel activation and their impact on GLUT4 traffic in muscle cells, as well as other implications of insulin-dependent Ca(2+) release from the SER. PMID:25224502

  10. Receptive fields and functional architecture of monkey striate cortex.

    PubMed

    Hubel, D H; Wiesel, T N

    1968-03-01

    1. The striate cortex was studied in lightly anaesthetized macaque and spider monkeys by recording extracellularly from single units and stimulating the retinas with spots or patterns of light. Most cells can be categorized as simple, complex, or hypercomplex, with response properties very similar to those previously described in the cat. On the average, however, receptive fields are smaller, and there is a greater sensitivity to changes in stimulus orientation. A small proportion of the cells are colour coded.2. Evidence is presented for at least two independent systems of columns extending vertically from surface to white matter. Columns of the first type contain cells with common receptive-field orientations. They are similar to the orientation columns described in the cat, but are probably smaller in cross-sectional area. In the second system cells are aggregated into columns according to eye preference. The ocular dominance columns are larger than the orientation columns, and the two sets of boundaries seem to be independent.3. There is a tendency for cells to be grouped according to symmetry of responses to movement; in some regions the cells respond equally well to the two opposite directions of movement of a line, but other regions contain a mixture of cells favouring one direction and cells favouring the other.4. A horizontal organization corresponding to the cortical layering can also be discerned. The upper layers (II and the upper two-thirds of III) contain complex and hypercomplex cells, but simple cells are virtually absent. The cells are mostly binocularly driven. Simple cells are found deep in layer III, and in IV A and IV B. In layer IV B they form a large proportion of the population, whereas complex cells are rare. In layers IV A and IV B one finds units lacking orientation specificity; it is not clear whether these are cell bodies or axons of geniculate cells. In layer IV most cells are driven by one eye only; this layer consists of a mosaic

  11. Use of flow, electrical, and mechanical stimulation to promote engineering of striated muscles.

    PubMed

    Rangarajan, Swathi; Madden, Lauran; Bursac, Nenad

    2014-07-01

    The field of tissue engineering involves design of high-fidelity tissue substitutes for predictive experimental assays in vitro and cell-based regenerative therapies in vivo. Design of striated muscle tissues, such as cardiac and skeletal muscle, has been particularly challenging due to a high metabolic demand and complex cellular organization and electromechanical function of the native tissues. Successful engineering of highly functional striated muscles may thus require creation of biomimetic culture conditions involving medium perfusion, electrical and mechanical stimulation. When optimized, these external cues are expected to synergistically and dynamically activate important intracellular signaling pathways leading to accelerated muscle growth and development. This review will discuss the use of different types of tissue culture bioreactors aimed at providing conditions for enhanced structural and functional maturation of engineered striated muscles.

  12. Proteins related to green algal striated fiber assemblin are present in stramenopiles and alveolates.

    PubMed

    Harper, John D I; Thuet, Jacques; Lechtreck, Karl F; Hardham, Adrienne R

    2009-07-01

    In green algae, striated fiber assemblin (SFA) is the major protein of the striated microtubule-associated fibers that are structural elements in the flagellar basal apparatus. Using Basic Local Alignment Search Tool (BLAST) searches of recently established databases, SFA-like sequences were detected in the genomes not only of green algal species but also of a range of other protists. These included species in two alveolate subgroups, the ciliates (Tetrahymena thermophila, Paramecium tetraurelia) and the dinoflagellates (Perkinsus marinus), and two stramenopile subgroups, the oomycetes (Phytophthora sojae, Phytophthora ramorum, Phytophthora infestans) and the diatoms (Thalassiosira pseudonana, Phaeodactylum tricornutum). Together with earlier identification of SFA-like sequences in the apicomplexans, these results indicate that homologs of SFA are present across the alveolates and stramenopiles. Antibodies raised against SFA from the green alga, Spermatozopsis similis, react in immunofluorescence assays with the two basal bodies and an anteriorly directed striated fiber in the flagellar apparatus of biflagellate Phytophthora zoospores.

  13. Use of flow, electrical, and mechanical stimulation to promote engineering of striated muscles

    PubMed Central

    Rangarajan, Swathi; Madden, Lauran; Bursac, Nenad

    2014-01-01

    The field of tissue engineering involves design of high-fidelity tissue substitutes for predictive experimental assays in vitro and cell-based regenerative therapies in vivo. Design of striated muscle tissues, such as cardiac and skeletal muscle, has been particularly challenging due to a high metabolic demand and complex cellular organization and electromechanical function of the native tissues. Successful engineering of highly functional striated muscles may thus require creation of biomimetic culture conditions involving medium perfusion, electrical and mechanical stimulation. When optimized, these external cues are expected to synergistically and dynamically activate important intracellular signaling pathways leading to accelerated muscle growth and development. This review will discuss the use of different types of tissue culture bioreactors aimed at providing conditions for enhanced structural and functional maturation of engineered striated muscles. PMID:24366526

  14. Striated boulder pavements within glaciomarine diamicts of the Yakataga Formation, Middleton Island, Alaska

    SciTech Connect

    Eyles, C.H.

    1985-01-01

    The presence of striated boulder pavements in glacial sequences is often cited as evidence of transport and deposition by grounded glacier ice. However, recent reports show that striated pavements also form in non-glacial environments by the abrasion of boulder lag surfaces by floating glacier and seasonal ice. Several striated boulder pavements are identified within Early Pleistocene upper Yakataga Formation sediments exposed on Middleton Island close to the southern edge of the Gulf of Alaska continental shelf. The sequence is dominated by thick stratiform units of massive and stratified diamict formed by the settling of fine-grained sands and muds from suspension together with ice-rafted debris. Boulder pavements outcrop as extensive planar horizons within the diamicts, can be traced for several kilometers along strike and consist of single lines of clasts with faceted upper surfaces showing consistently oriented striation directions. Clasts are not preferentially aligned, however, and do not have the characteristic bullet shape of boulders transported at a glacier base and deposited by lodgement processes. Striated boulder pavements on Middleton Island appear to have formed as boulder lag surfaces generated by wave and tidal current reworking of diamict on relatively shallow banks. Lags were then overridden and abraded by a grounding ice shelf. The glacially-abraded boulder pavements on Middleton Island record the repeated expansion of a continuous ice shelf to the edge of the Gulf of Alaska continental shelf during the Early Pleistocene.

  15. Ultrastructure of geniculocortical synaptic connections in the tree shrew striate cortex.

    PubMed

    Familtsev, Dmitry; Quiggins, Ranida; Masterson, Sean P; Dang, Wenhao; Slusarczyk, Arkadiusz S; Petry, Heywood M; Bickford, Martha E

    2016-04-15

    To determine whether thalamocortical synaptic circuits differ across cortical areas, we examined the ultrastructure of geniculocortical terminals in the tree shrew striate cortex to compare directly the characteristics of these terminals with those of pulvinocortical terminals (examined previously in the temporal cortex of the same species; Chomsung et al. [] Cereb Cortex 20:997-1011). Tree shrews are considered to represent a prototype of early prosimian primates but are unique in that sublaminae of striate cortex layer IV respond preferentially to light onset (IVa) or offset (IVb). We examined geniculocortical inputs to these two sublayers labeled by tracer or virus injections or an antibody against the type 2 vesicular glutamate antibody (vGLUT2). We found that layer IV geniculocortical terminals, as well as their postsynaptic targets, were significantly larger than pulvinocortical terminals and their postsynaptic targets. In addition, we found that 9-10% of geniculocortical terminals in each sublamina contacted GABAergic interneurons, whereas pulvinocortical terminals were not found to contact any interneurons. Moreover, we found that the majority of geniculocortical terminals in both IVa and IVb contained dendritic protrusions, whereas pulvinocortical terminals do not contain these structures. Finally, we found that synaptopodin, a protein uniquely associated with the spine apparatus, and telencephalin (TLCN, or intercellular adhesion molecule type 5), a protein associated with maturation of dendritic spines, are largely excluded from geniculocortical recipient layers of the striate cortex. Together our results suggest major differences in the synaptic organization of thalamocortical pathways in striate and extrastriate areas.

  16. Magnetization transfer imaging reveals geniculocalcarine and striate area degeneration in primary glaucoma: a preliminary study

    PubMed Central

    Zhang, Yan; Liang, Wenwen; Wu, Guijun; Zhang, Xuelin

    2016-01-01

    Background Glaucoma is a neurodegenerative disease that affects both the retina and central visual pathway. Magnetization transfer imaging (MTI) is a sensitive magnetic resonance imaging (MRI) technique that can detect degenerative changes in the brain. Purpose To investigate the geniculocalcarine (GCT) and striate areas in primary glaucoma patients using region of interest (ROI) analysis of magnetization transfer ratio (MTR). Material and Methods Twenty patients with primary glaucoma in both eyes were compared with 31 healthy control patients. All of the participants were examined on a 3.0 T scanner using a three-dimensional T1-weighted spoiled gradient recalled acquisition (SPGR) with and without a MT saturation pulse. A two-sample t-test was used to evaluate the MTR difference between the groups. P < 0.05 was used to determine statistical significance. Results The MTR of the glaucoma group was lower than the healthy controls in both the bilateral GCT (t = 3.781, P = 0.001) and striate areas (t = 4.177, P = 0.000). Conclusion The MTR reductions in the bilateral GCT and striate areas suggest that there is GCT demyelination and striate area degeneration in primary glaucoma. These neurodegenerative effects may be induced as a direct effect of retrograde axonal degeneration along with the indirect effect of anterograde trans-synaptic degeneration.

  17. The retinotopic organization of striate cortex is well predicted by surface topology

    PubMed Central

    Benson, Noah C.; Butt, Omar H.; Datta, Ritobrato; Radoeva, Petya D.; Brainard, David H.; Aguirre, Geoffrey Karl

    2012-01-01

    Summary In 1918, Gordon Holmes combined observations of visual field scotomas across brain lesioned soldiers to produce a schematic map of the projection of the visual field upon the striate cortex [1]. One limit to the precision of his result, and the mapping of anatomy to retinotopy generally, is the substantial individual variation in the size [2,3], volumetric position [4], and cortical magnification [5] of area V1. When viewed within the context of the curvature of the cortical surface, however, the boundaries of striate cortex fall at a consistent location across individuals [6]. We asked if the surface topology of the human brain can be used to accurately predict the internal, retinotopic function of striate cortex as well. We used fMRI to measure polar angle and eccentricity in 25 participants and combined their maps within a left-right, transform-symmetric representation of the cortical surface [7]. These data were then fit using a deterministic, algebraic model of visual field representation [8]. We found that an anatomical image alone can be used to predict the retinotopic organization of striate cortex for an individual as accurately as 10–25 minutes of functional mapping. This indicates tight developmental linkage of structure and function within a primary, sensory cortical area. PMID:23041195

  18. Structure and protein composition of the striated flagellar rootlets of some protists.

    PubMed

    Dingle, A D; Larson, D E

    1981-01-01

    The striated rootlets of different protists are extremely diverse and, on the basis of structural organization, can be assigned to no fewer than four major types. In light of this extreme variation in fine-structure is it reasonable to expect that all striated rootlets may share common protein species? Using the flagellar rootlet of Naegleria gruberi strain NB-1 as reference, we compared rootlet size, structure, and protein composition to another Naegleria strain, another amoebo-flagellate, Tetramitus rostratus, and to the ciliate Tetrahymena pyriformis. Although differing in size and distribution in the cells, the rootlets of all three amoebo-flagellates appeared very similar in structure, periodicity, and in the presence of a common 170 000 Dalton subunit. Kinetodesmal fibres of Tetrahymena differed markedly in detailed fine-structure, in periodicity, and in the apparent absence of the 170 000 Dalton subunit as tested either by SDS gel electrophoresis or by indirect immunofluorescence staining using a specific antiserum directed against the NB-1 major rootlet protein. Consideration of literature describing striated rootlet structure in a wide variety of ciliated and flagellated cells led to the speculation that striated rootlets arose subsequent to primitive flagella and likely evolved along two major pathways: a narrow-period rootlet similar to those discussed above, which developed from the microtubule rootlets of algal flagellates, and a wide-band, contractile rootlet which originated from the primitive interbasal body connector prominent in both algal and protozoan species.

  19. Magnetization transfer imaging reveals geniculocalcarine and striate area degeneration in primary glaucoma: a preliminary study

    PubMed Central

    Zhang, Yan; Liang, Wenwen; Wu, Guijun; Zhang, Xuelin

    2016-01-01

    Background Glaucoma is a neurodegenerative disease that affects both the retina and central visual pathway. Magnetization transfer imaging (MTI) is a sensitive magnetic resonance imaging (MRI) technique that can detect degenerative changes in the brain. Purpose To investigate the geniculocalcarine (GCT) and striate areas in primary glaucoma patients using region of interest (ROI) analysis of magnetization transfer ratio (MTR). Material and Methods Twenty patients with primary glaucoma in both eyes were compared with 31 healthy control patients. All of the participants were examined on a 3.0 T scanner using a three-dimensional T1-weighted spoiled gradient recalled acquisition (SPGR) with and without a MT saturation pulse. A two-sample t-test was used to evaluate the MTR difference between the groups. P < 0.05 was used to determine statistical significance. Results The MTR of the glaucoma group was lower than the healthy controls in both the bilateral GCT (t = 3.781, P = 0.001) and striate areas (t = 4.177, P = 0.000). Conclusion The MTR reductions in the bilateral GCT and striate areas suggest that there is GCT demyelination and striate area degeneration in primary glaucoma. These neurodegenerative effects may be induced as a direct effect of retrograde axonal degeneration along with the indirect effect of anterograde trans-synaptic degeneration. PMID:27651931

  20. Non-conscious recognition of affect in the absence of striate cortex.

    PubMed

    de Gelder, B; Vroomen, J; Pourtois, G; Weiskrantz, L

    1999-12-16

    Functional neuroimaging experiments have shown that recognition of emotional expressions does not depend on awareness of visual stimuli and that unseen fear stimuli can activate the amygdala via a colliculopulvinar pathway. Perception of emotional expressions in the absence of awareness in normal subjects has some similarities with the unconscious recognition of visual stimuli which is well documented in patients with striate cortex lesions (blindsight). Presumably in these patients residual vision engages alternative extra-striate routes such as the superior colliculus and pulvinar. Against this background, we conjectured that a blindsight subject (GY) might recognize facial expressions presented in his blind field. The present study now provides direct evidence for this claim. PMID:10716205

  1. Z-line formins promote contractile lattice growth and maintenance in striated muscles of C. elegans

    PubMed Central

    Mi-Mi, Lei; Votra, SarahBeth; Kemphues, Kenneth; Bretscher, Anthony

    2012-01-01

    Muscle contraction depends on interactions between actin and myosin filaments organized into sarcomeres, but the mechanism by which actin filaments incorporate into sarcomeres remains unclear. We have found that, during larval development in Caenorhabditis elegans, two members of the actin-assembling formin family, CYK-1 and FHOD-1, are present in striated body wall muscles near or on sarcomere Z lines, where barbed ends of actin filaments are anchored. Depletion of either formin during this period stunted growth of the striated contractile lattice, whereas their simultaneous reduction profoundly diminished lattice size and number of striations per muscle cell. CYK-1 persisted at Z lines in adulthood, and its near complete depletion from adults triggered phenotypes ranging from partial loss of Z line–associated filamentous actin to collapse of the contractile lattice. These results are, to our knowledge, the first genetic evidence implicating sarcomere-associated formins in the in vivo organization of the muscle cytoskeleton. PMID:22753896

  2. Amino acid sequence of horseshoe crab, Tachypleus tridentatus, striated muscle troponin C.

    PubMed

    Kobayashi, T; Kagami, O; Takagi, T; Konishi, K

    1989-05-01

    The amino acid sequence of troponin C obtained from horseshoe crab, Tachypleus tridentatus, striated muscle was determined by sequence analysis and alignments of chemically and enzymatically cleaved peptides. Troponin C is composed of 153 amino acid residues with a blocked N-terminus and contains no tryptophan or cysteine residue. The site I, one of the four Ca2+-binding sites, is considered to have lost its ability to bind Ca2+ owing to the replacements of certain amino acid residues.

  3. Neural correlates of visual motion processing without awareness in patients with striate cortex and pulvinar lesions.

    PubMed

    Barleben, Maria; Stoppel, Christian M; Kaufmann, Jörn; Merkel, Christian; Wecke, Thoralf; Goertler, Michael; Heinze, Hans-Jochen; Hopf, Jens-Max; Schoenfeld, Mircea A

    2015-04-01

    Patients with striate cortex lesions experience visual perception loss in the contralateral visual field. In few patients, however, stimuli within the blind field can lead to unconscious (blindsight) or even conscious perception when the stimuli are moving (Riddoch syndrome). Using functional magnetic resonance imaging (fMRI), we investigated the neural responses elicited by motion stimulation in the sighted and blind visual fields of eight patients with lesions of the striate cortex. Importantly, repeated testing ensured that none of the patients exhibited blindsight or a Riddoch syndrome. Three patients had additional lesions in the ipsilesional pulvinar. For blind visual field stimulation, great care was given that the moving stimulus was precisely presented within the borders of the scotoma. In six of eight patients, the stimulation within the scotoma elicited hemodynamic activity in area human middle temporal (hMT) while no activity was observed within the ipsilateral lesioned area of the striate cortex. One of the two patients in whom no ipsilesional activity was observed had an extensive lesion including massive subcortical damage. The other patient had an additional focal lesion within the lateral inferior pulvinar. Fiber-tracking based on anatomical and functional markers (hMT and Pulvinar) on individual diffusion tensor imaging (DTI) data from each patient revealed the structural integrity of subcortical pathways in all but the patient with the extensive subcortical lesion. These results provide clear evidence for the robustness of direct subcortical pathways from the pulvinar to area hMT in patients with striate cortex lesions and demonstrate that ipsilesional activity in area hMT is completely independent of conscious perception. PMID:25529748

  4. Segregation of striated and smooth muscle lineages by a Notch-dependent regulatory network

    PubMed Central

    2014-01-01

    Background Lineage segregation from multipotent epithelia is a central theme in development and in adult stem cell plasticity. Previously, we demonstrated that striated and smooth muscle cells share a common progenitor within their epithelium of origin, the lateral domain of the somite-derived dermomyotome. However, what controls the segregation of these muscle subtypes remains unknown. We use this in vivo bifurcation of fates as an experimental model to uncover the underlying mechanisms of lineage diversification from bipotent progenitors. Results Using the strength of spatio-temporally controlled gene missexpression in avian embryos, we report that Notch harbors distinct pro-smooth muscle activities depending on the duration of the signal; short periods prevent striated muscle development and extended periods, through Snail1, promote cell emigration from the dermomyotome towards a smooth muscle fate. Furthermore, we define a Muscle Regulatory Network, consisting of Id2, Id3, FoxC2 and Snail1, which acts in concert to promote smooth muscle by antagonizing the pro-myogenic activities of Myf5 and Pax7, which induce striated muscle fate. Notch and BMP closely regulate the network and reciprocally reinforce each other’s signal. In turn, components of the network strengthen Notch signaling, while Pax7 silences this signaling. These feedbacks augment the robustness and flexibility of the network regulating muscle subtype segregation. Conclusions Our results demarcate the details of the Muscle Regulatory Network, underlying the segregation of muscle sublineages from the lateral dermomyotome, and exhibit how factors within the network promote the smooth muscle at the expense of the striated muscle fate. This network acts as an exemplar demonstrating how lineage segregation occurs within epithelial primordia by integrating inputs from competing factors. PMID:25015411

  5. Visual receptive fields in the striate-recipient zone of the lateral posterior-pulvinar complex.

    PubMed

    Chalupa, L M; Abramson, B P

    1989-01-01

    The lateral posterior (LP)-pulvinar complex of the cat is known to contain multiple visual areas. In the present study, we examined the receptive field properties of single neurons isolated in the lateral division of this complex (the LPI). The LPI is designated the striate-recipient zone because it is the only region of the LP-pulvinar receiving cortical projections from areas 17 and 18. The recordings revealed that the striate-recipient zone of LP comprises 2 subareas, which we have termed LPI-1 and LPI-2. In the main segment (LPI-1), virtually all cells responded securely to visual stimuli. The vast majority of these neurons were binocular, with relatively small and well-defined receptive fields. More than half of the cells were found to be directionally selective, and almost this many were orientation specific. The orientation tuning of these cells was found to be quite precise, comparable to complex cells in area 17. In contrast, in the small dorsolateral segment of the striate-recipient zone (the LPI-2), a substantial proportion of cells could not be visually activated. Here, the visual cells had very large receptive fields, and relatively few were direction or orientation selective. The LPI-2 receives subcortical inputs from the superficial layers of the superior colliculus, the hypothalamus, and cerebellum, while the LPI-1 is innervated only by cortical axons. It is suggested that the subcortical connections of the LPI-2 account for the differences in the response properties of the 2 striate-recipient areas. The present results, in conjunction with our previous findings on the principal tectorecipient zone (Chalupa et al., 1983), permit 2 generalizations regarding the functional organization of the cat's LP-pulvinar complex. First, there are clear differences among the visual areas of the LP-pulvinar in the cellular processing of visual information. Second, these functional differences can be related to the principal sources of visual input to the various

  6. The significance of striated muscle in the mammary glands of marsupials.

    PubMed Central

    Griffiths, M; Slater, E

    1988-01-01

    The distribution and amounts of striated muscle within the mammary glands of pouched and pouchless marsupials from Australia and South America are described. Invasions into the mammary secretory parenchyma in pouchless marsupials by swathes of striated muscle from the ilio-marsupialis muscle are massive, in some instances concentrated into discrete muscles, which are inserted on to the bases of the teats; the name retractor mammae is proposed for these muscles. In pouched marsupials striated muscle penetrates the parenchyma, but the distribution is diffuse and the muscle strands are not inserted on to teats except in the instance of the glands of the honey possum Tarsipes rostratus. The young of anaesthetised pouchless marsupials hang down from the teats; as anaesthesia wears off they are hauled up tightly into the mammary area. It is concluded that this is a result of contraction of the retractor mammae muscles and that it is a means of protecting the naked young from injury by rough terrain. The mammary gland musculature in pouched marsupials is considered to be vestigial, but its contraction may have the function of initiating a 'tap-response' contraction of myoepithelium acting synergistically with the 'let-down' hormone mesotocin. Mechanisms of imbibition of milk by marsupial neonates, based on observations that they can suck fluid from non-distortable tubes, are discussed. Images Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 PMID:3417541

  7. Striated muscle involvement in experimental oral infection by herpes simplex virus type 1.

    PubMed

    Gonzalez, María Inés; Sanjuan, Norberto A

    2013-07-01

    Herpes simplex virus type 1 is one of the most frequent causes of oral infection in humans, especially during early childhood. Several experimental models have been developed to study the pathogenesis of this virus but all of them employed adult animals. In this work, we developed an experimental model that uses mice younger than 4 days old, to more closely resemble human infection. Mice were infected subcutaneously with the prototype strain McIntyre of Herpes simplex-1, and the progression of infection was studied by immunoperoxidase. All animals died within 24-72 h post-infection, while viral antigens were found in the oral epithelium, nerves and brain. The most striking result was the finding of viral antigens in the nucleus and cytoplasm of cells belonging to striated muscles. Organotypic cultures of striated muscles were performed, and viral replication was observed in them by immunocytochemistry, electron microscopy and viral isolation. We conclude that the infection of striated muscles is present from the onset of oral infection and, eventually, could explain some clinical observations in humans.

  8. Muscle Lim Protein isoform negatively regulates striated muscle actin dynamics and differentiation

    PubMed Central

    Vafiadaki, Elizabeth; Arvanitis, Demetrios A.; Papalouka, Vasiliki; Terzis, Gerasimos; Roumeliotis, Theodoros I.; Spengos, Konstantinos; Garbis, Spiros D.; Manta, Panagiota; Kranias, Evangelia G.; Sanoudou, Despina

    2015-01-01

    Muscle Lim Protein (MLP) has emerged as a critical regulator of striated muscle physiology and pathophysiology. Mutations in cysteine and glycine-rich protein 3 (CSRP3), the gene encoding MLP, have been directly associated with human cardiomyopathies, while aberrant expression patterns are reported in human cardiac and skeletal muscle diseases. Increasing evidence suggests that MLP has an important role in both myogenic differentiation and myocyte cytoarchitecture, although the full spectrum of its intracellular roles has not been delineated. We report the discovery of an alternative splice variant of MLP, designated as MLP-b, showing distinct expression in neuromuscular disease and direct roles in actin dynamics and muscle differentiation. This novel isoform originates by alternative splicing of exons 3 and 4. At the protein level, it contains the N-terminus first half LIM domain of MLP and a unique sequence of 22 amino acids. Physiologically it is expressed during early differentiation, whereas its overexpression reduces C2C12 differentiation and myotube formation. This may be mediated through its inhibition of MLP/CFL2-mediated F-actin dynamics. In differentiated striated muscles, MLP-b localizes to the sarcomeres and binds directly to Z-disc components including α-actinin, T-cap and MLP. Our findings unveil a novel player in muscle physiology and pathophysiology that is implicated in myogenesis as a negative regulator of myotube formation, and in differentiated striated muscles as a contributor to sarcomeric integrity. PMID:24860983

  9. Myosin filament sliding through the Z-disc relates striated muscle fibre structure to function.

    PubMed

    Rode, Christian; Siebert, Tobias; Tomalka, Andre; Blickhan, Reinhard

    2016-03-16

    Striated muscle contraction requires intricate interactions of microstructures. The classic textbook assumption that myosin filaments are compressed at the meshed Z-disc during striated muscle fibre contraction conflicts with experimental evidence. For example, myosin filaments are too stiff to be compressed sufficiently by the muscular force, and, unlike compressed springs, the muscle fibres do not restore their resting length after contractions to short lengths. Further, the dependence of a fibre's maximum contraction velocity on sarcomere length is unexplained to date. In this paper, we present a structurally consistent model of sarcomere contraction that reconciles these findings with the well-accepted sliding filament and crossbridge theories. The few required model parameters are taken from the literature or obtained from reasoning based on structural arguments. In our model, the transition from hexagonal to tetragonal actin filament arrangement near the Z-disc together with a thoughtful titin arrangement enables myosin filament sliding through the Z-disc. This sliding leads to swivelled crossbridges in the adjacent half-sarcomere that dampen contraction. With no fitting of parameters required, the model predicts straightforwardly the fibre's entire force-length behaviour and the dependence of the maximum contraction velocity on sarcomere length. Our model enables a structurally and functionally consistent view of the contractile machinery of the striated fibre with possible implications for muscle diseases and evolution.

  10. Distinctive serum miRNA profile in mouse models of striated muscular pathologies.

    PubMed

    Vignier, Nicolas; Amor, Fatima; Fogel, Paul; Duvallet, Angélique; Poupiot, Jérôme; Charrier, Sabine; Arock, Michel; Montus, Marie; Nelson, Isabelle; Richard, Isabelle; Carrier, Lucie; Servais, Laurent; Voit, Thomas; Bonne, Gisèle; Israeli, David

    2013-01-01

    Biomarkers are critically important for disease diagnosis and monitoring. In particular, close monitoring of disease evolution is eminently required for the evaluation of therapeutic treatments. Classical monitoring methods in muscular dystrophies are largely based on histological and molecular analyses of muscle biopsies. Such biopsies are invasive and therefore difficult to obtain. The serum protein creatine kinase is a useful biomarker, which is however not specific for a given pathology and correlates poorly with the severity or course of the muscular pathology. The aim of the present study was the systematic evaluation of serum microRNAs (miRNAs) as biomarkers in striated muscle pathologies. Mouse models for five striated muscle pathologies were investigated: Duchenne muscular dystrophy (DMD), limb-girdle muscular dystrophy type 2D (LGMD2D), limb-girdle muscular dystrophy type 2C (LGMD2C), Emery-Dreifuss muscular dystrophy (EDMD) and hypertrophic cardiomyopathy (HCM). Two-step RT-qPCR methodology was elaborated, using two different RT-qPCR miRNA quantification technologies. We identified miRNA modulation in the serum of all the five mouse models. The most highly dysregulated serum miRNAs were found to be commonly upregulated in DMD, LGMD2D and LGMD2C mouse models, which all exhibit massive destruction of striated muscle tissues. Some of these miRNAs were down rather than upregulated in the EDMD mice, a model without massive myofiber destruction. The dysregulated miRNAs identified in the HCM model were different, with the exception of one dysregulated miRNA common to all pathologies. Importantly, a specific and distinctive circulating miRNA profile was identified for each studied pathological mouse model. The differential expression of a few dysregulated miRNAs in the DMD mice was further evaluated in DMD patients, providing new candidates of circulating miRNA biomarkers for DMD.

  11. Ultrastructural studies of the mitochondriae in the striated muscles of birds with regard to experimental hypokinesis

    NASA Technical Reports Server (NTRS)

    Belak, M.; Kocisova, J.; Boda, K.

    1980-01-01

    Electron microscopic studies were carried out on the mitochrondria of the transversely striated muscles with regard to experimental hypokinesia. As compared to the central group the mitochondria of m. pectoralis thoracicus and the m. iliotibialis posterior in hypokinetic birds reveal marked changes. In filamentous and ovoid mitochondria, vacuoles can be observed which in some cases produced larger light formations with following disappearance of the cristae and destruction of mitochondria. Fat particles located at the poles of the altered mitochondria, sporadically occurring also laterally, presented another finding. The Z-lines of the sarcomere did not form a continuous line, but were somewhat shifted.

  12. Actin capping proteins, CapZ (β-actinin) and tropomodulin in amphioxus striated muscle.

    PubMed

    Bao, Yulong; Kake, Takei; Hanashima, Akira; Nomiya, Yui; Kubokawa, Kaoru; Kimura, Sumiko

    2012-11-15

    CapZ (β-actinin) and tropomodulin (Tmod) are capping proteins involved in the maintenance of thin filaments in vertebrate skeletal muscles. In this study, we focused on amphioxus, the most primitive chordate. We searched for CapZ and Tmod genes in the amphioxus genome and determined their primary structures. Amphioxus possess one CapZα gene (CAPZA) and one CapZβ gene (CAPZB), and the transcripts of these genes were found to be 67%-85% identical to those of human CapZ genes. On the other hand, amphioxus contain one Tmod gene (TMOD), and the product of this gene has an identity of approximately 50% with human Tmod genes 1-4. However, helix 2 of amphioxus Tmod, which is involved in protein-binding to tropomyosin, was highly conserved with approximately 74% identity to human Tmod genes. Western blotting indicated the presence of CapZ and Tmod in the striated muscle of amphioxus. These results suggest that unlike most of vertebrates, such as fish, amphibian, bird, and mammal, CapZ from amphioxus striated muscle is derived from two genes CAPZA and CAPZB, and Tmod is derived from one TMOD gene.

  13. The Popeye Domain Containing Genes and their Function in Striated Muscle

    PubMed Central

    Schindler, Roland FR; Scotton, Chiara; French, Vanessa; Ferlini, Alessandra; Brand, Thomas

    2016-01-01

    The Popeye domain containing (POPDC) genes encode a novel class of cAMP effector proteins, which are abundantly expressed in heart and skeletal muscle. Here we will review their role in striated muscle as deduced from work in cell and animal models and the recent analysis of patients carrying a missense mutation in POPDC1. Evidence suggests that POPDC proteins control membrane trafficking of interacting proteins. Furthermore, we will discuss the current catalogue of established protein-protein interactions. In recent years, the number of POPDC-interacting proteins is rising and currently includes ion channels (TREK-1), sarcolemma-associated proteins serving functions in mechanical stability (Dystrophin), compartmentalization (Caveolin 3), scaffolding (ZO-1), trafficking (NDRG4, VAMP2/3) and repair (Dysferlin), or acting as a guanine nucleotide exchange factor for Rho-family GTPases (GEFT). Recent evidence suggests that POPDC proteins might also control the cellular level of the nuclear proto-oncoprotein c-Myc. These data suggests that this family of cAMP-binding proteins probably serves multiple roles in striated muscle. PMID:27347491

  14. MRI in occipital lobe infarcts: classification by involvement of the striate cortex.

    PubMed

    Kitajima, M; Korogi, Y; Kido, T; Ikeda, O; Morishita, S; Takahashi, M

    1998-11-01

    We reviewed the MRI studies of 25 patients with occipital lobe infarcts to clarify the distribution of infarcts in the posterior cerebral arterial territory, focussing on their relationship to the striate cortex. Visual field defects and MRI findings were also correlated in 16 patients. On coronal and/or sagittal images, the distribution of the infarct and its relationship to the striate cortex were classified. Involvement of the cortex of both upper and lower lips of the calcarine fissure was observed in 10 patients, and involvement of the lower lip alone in 15. The upper cortical lesions were always accompanied by lower cortical lesions. The visual field defects were complete hemianopia in nine patients, superior quadrantanopia in six and hemianopia with a preserved temporal crescent in one. All patients with superior quadrantanopia had involvement of the lower cortex alone; there were no cases of inferior quadrantanopia. The characteristic vascular anatomy, and poor development of the collateral circulation in the lower cortical area, may explain the vulnerability of this area to infarcts.

  15. [A cause of terminal constipation: hypertonia of the striated pelvic muscle. Value of complementary studies].

    PubMed

    Veyrac, M; Parelon, G; Daures, J P; Bories, P; Michel, H

    1988-12-01

    The aim of this study was to define an other cause of idiopathic constipation with a mathematic automatic classification Fifty patients were studied by colonic transit time, anorectal manometry and defecography. Three classical causes were found: 12 patients had hypertonic upper anal pressure; 8 patients had abnormal rectonanal inhibitory reflex and 12 patients had anatomic conditions reducing stool frequencies Automatic mathematic classification coming from optimised bowls technic has led to the characterization of a new cause. Eight young women (mean age 33 years) with hypertonic striated pelvic muscles on straining were identified. Three items were significantly different: defect of sphincteric relaxation without high sphincteric pressure; closure or non opening anorectal angle, hypertonic levator ani on straining. There was a significant high frequency (p less than 0.05) of urinary disorders in this new group. All abnormalities occurred during defecation. This group can be studied with other methods: balloon expulsion, anal electromyography. Clinical identity with urinary pathology may be explained by common neurologic disorders of pelvic striated muscle innervation.

  16. A striated muscle on the hard palate of rodents and rabbits.

    PubMed

    Pavlíková, H; Witter, K; Mísek, I

    2004-04-01

    Summary A striated muscle of the hard palate has been previously described in some rodents and rabbits. It is not termed in the official veterinary anatomical nomenclature. The aim of this work was to verify the existence of this muscle. Heads of the golden hamster (Mesocricetus auratus), the guinea pig (Cavia aperea f. porcellus), the laboratory rat (Rattus norvegicus var. alba), the field vole (Microtus agrestis) and the domestic rabbit (Oryctolagus cuniculus f. domesticus) have been dissected. Moreover, histological sections have been prepared from heads of the field vole. In all species under study, we could detect a striated muscle of the hard palate composed of an anterior and a posterior muscle. The anterior muscle originated on the os incisivum and diverged in anterior, lateral and posterior directions. The posterior muscle originated on the processus palatinus maxillae and verged into the m. buccinator. Inter-species differences could be detected in shape and position of the muscle. The palatal muscle was innervated by the ramus buccalis of the facial nerve. Whether this muscle should be classified as an individual facial muscle or as a part of the m. buccinator remains to be discussed. PMID:15027950

  17. Striated Acto-Myosin Fibers Can Reorganize and Register in Response to Elastic Interactions with the Matrix

    PubMed Central

    Friedrich, Benjamin M.; Buxboim, Amnon; Discher, Dennis E.; Safran, Samuel A.

    2011-01-01

    The remarkable striation of muscle has fascinated many for centuries. In developing muscle cells, as well as in many adherent, nonmuscle cell types, striated, stress fiberlike structures with sarcomere-periodicity tend to register: Based on several studies, neighboring, parallel fibers at the basal membrane of cultured cells establish registry of their respective periodic sarcomeric architecture, but, to our knowledge, the mechanism has not yet been identified. Here, we propose for cells plated on an elastic substrate or adhered to a neighboring cell, that acto-myosin contractility in striated fibers close to the basal membrane induces substrate strain that gives rise to an elastic interaction between neighboring striated fibers, which in turn favors interfiber registry. Our physical theory predicts a dependence of interfiber registry on externally controllable elastic properties of the substrate. In developing muscle cells, registry of striated fibers (premyofibrils and nascent myofibrils) has been suggested as one major pathway of myofibrillogenesis, where it precedes the fusion of neighboring fibers. This suggests a mechanical basis for the optimal myofibrillogenesis on muscle-mimetic elastic substrates that was recently observed by several groups in cultures of mouse-, human-, and chick-derived muscle cells. PMID:21641316

  18. Modulation of the cytosolic androgen receptor in striated muscle by sex steroids

    NASA Technical Reports Server (NTRS)

    Rance, N. E.; Max, S. E.

    1982-01-01

    The influence of orchiectomy (GDX) and steroid administration on the level of the cytosolic androgen receptor in the rat levator ani muscle and in rat skeletal muscles (tibialis anterior and extensor digitorum longus) was studied. Androgen receptor binding to muscle cytosol was measured using H-3 methyltrienolone (R1881) as ligand, 100 fold molar excess unlabeled R1881 to assess nonspecific binding, and 500 fold molar excess of triamcinolone acetonide to prevent binding to glucocorticoid and progestin receptors. Results demonstrate that modification of the levels of sex steroids can alter the content of androgen receptors of rat striated muscle. Data suggest that: (1) cytosolic androgen receptor levels increase after orchiectomy in both levator ani muscle and skeletal muscle; (2) the acute increase in receptor levels is blocked by an inhibitor of protein synthesis; and (3) administration of estradiol-17 beta to castrated animals increases receptor binding in levator ani muscle but not in skeletal muscle.

  19. Morphometric variability of minicolumns in the striate cortex of Homo sapiens, Macaca mulatta, and Pan troglodytes.

    PubMed

    Casanova, Manuel F; Trippe, Juan; Tillquist, Christopher; Switala, Andrew E

    2009-02-01

    Radially oriented ensembles of neurons and their projections, termed minicolumns, are hypothesized to be the basic microcircuit of mammalian cerebral cortex. Minicolumns can be divided into a core and a peripheral neuropil space compartment. The core of minicolumns is constrained by the migratory path of pyramidal cells and their attendant radially oriented projections. Variation in minicolumnar morphometry and density is observed both within and across species. Using a scale-independent measure of variability in minicolumnar width (V(CW)), we demonstrated a significant increase in V(CW) in layers III-V of striate cortex in humans relative to macaques and chimpanzees. Despite changes in minicolumnar width (CW) across species, their core space (w) remained the same. Given that cellular elements and processes within the peripheral neuropil space of minicolumns are derived from assorted sources, cross-species differences in VCW may result from genetic and epigenetic influences acting primarily on this compartment of the minicolumn.

  20. Analytical study of striated nozzle flow with small radius of curvature ratio throats

    NASA Technical Reports Server (NTRS)

    Norton, D. J.; White, R. E.

    1972-01-01

    An analytical method was developed which is capable of estimating the chamber and throat conditions in a nozzle with a low radius of curvature throat. The method was programmed using standard FORTRAN 4 language and includes chemical equilibrium calculation subprograms (modified NASA Lewis program CEC71) as an integral part. The method determines detailed and gross rocket characteristics in the presence of striated flows and gives detailed results for the motor chamber and throat plane with as many as 20 discrete zones. The method employs a simultaneous solution of the mass, momentum, and energy equations and allows propellant types, 0/F ratios, propellant distribution, nozzle geometry, and injection schemes to be varied so to predict spatial velocity, density, pressure, and other thermodynamic variable distributions in the chamber as well as the throat. Results for small radius of curvature have shown good comparison to experimental results. Both gaseous and liquid injection may be considered with frozen or equilibrium flow calculations.

  1. Isoform composition, gene expression and sarcomeric protein phosphorylation in striated muscle of mice after space flight

    NASA Astrophysics Data System (ADS)

    Vikhlyantsev, Ivan; Ulanova, Anna; Salmov, Nikolay; Gritsyna, Yulia; Bobylev, Alexandr; Rogachevsky, Vadim; Shenkman, Boris; Podlubnaya, Zoya

    Using RT-PCR and SDS-PAGE, changes in isoform composition, gene expression, titin and nebulin phosphorylation, as well as changes in isoform composition of myosin heavy chains in striated muscles of mice were studied after 30-day-long space flight onboard the Russian spacecraft “BION-M” No. 1. The muscle fibre-type shift from slow-to-fast was observed in m. gastrocnemius and m. tibialis anterior of animals from “Flight” group. A decrease in the content of the NT and N2A titin isoforms and nebulin in the skeletal muscles of animals from “Flight” group was found. Meanwhile, significant differences in gene expression of these proteins in skeletal muscles of mice from “Flight” and “Control” groups were not observed. Using Pro-Q Diamond stain, an increase in titin phosphorylation in m. gastrocnemius of mice from “Flight” group was detected. The content of the NT, N2BA and N2B titin isoforms in cardiac muscle of mice from “Flight” and “Control” groups did not differ, nevertheless an increase in titin gene expression in the myocardium of the “Flight” group animals was found. The observed changes will be discussed in the context of theirs role in contractile activity of striated muscles of mice in conditions of weightlessness. This work was supported by the Russian Foundation for Basic Research (grants No. 14-04-32240, 14-04-00112). Acknowledgement. We express our gratitude to the teams of Institute of Biomedical Problems RAS and “PROGRESS” Corporation involved in the preparation of the “BION-M” mission.

  2. Neurons in Striate Cortex Signal Disparity in Half-Matched Random-Dot Stereograms

    PubMed Central

    Read, Jenny C. A.; Cumming, Bruce G.

    2016-01-01

    Human stereopsis can operate in dense “cyclopean” images containing no monocular objects. This is believed to depend on the computation of binocular correlation by neurons in primary visual cortex (V1). The observation that humans perceive depth in half-matched random-dot stereograms, although these stimuli have no net correlation, has led to the proposition that human depth perception in these stimuli depends on a distinct “matching” computation possibly performed in extrastriate cortex. However, recording from disparity-selective neurons in V1 of fixating monkeys, we found that they are in fact able to signal disparity in half-matched stimuli. We present a simple model that explains these results. This reinstates the view that disparity-selective neurons in V1 provide the initial substrate for perception in dense cyclopean stimuli, and strongly suggests that separate correlation and matching computations are not necessary to explain existing data on mixed correlation stereograms. SIGNIFICANCE STATEMENT The initial step in stereoscopic 3D vision is generally thought to be a correlation-based computation that takes place in striate cortex. Recent research has argued that there must be an additional matching computation involved in extracting stereoscopic depth in random-dot stereograms. This is based on the observation that humans can perceive depth in stimuli with a mean binocular correlation of zero (where a correlation-based mechanism should not signal depth). We show that correlation-based cells in striate cortex do in fact signal depth here because they convert fluctuations in the correlation level into a mean change in the firing rate. Our results reinstate the view that these cells provide a sufficient substrate for the perception of stereoscopic depth. PMID:27559177

  3. Involvement of catecholaminergic neurons in motor innervation of striated muscle in the mouse esophagus.

    PubMed

    van der Keylen, Piet; Garreis, Fabian; Steigleder, Ruth; Sommer, Daniel; Neuhuber, Winfried L; Wörl, Jürgen

    2016-05-01

    Enteric co-innervation is a peculiar innervation pattern of striated esophageal musculature. Both anatomical and functional data on enteric co-innervation related to various transmitters have been collected in different species, although its function remains enigmatic. However, it is unclear whether catecholaminergic components are involved in such a co-innervation. Thus, we examined to identify catecholaminergic neuronal elements and clarify their relationship to other innervation components in the esophagus, using immunohistochemistry with antibodies against tyrosine hydroxylase (TH), vesicular acetylcholine transporter (VAChT), choline acetyltransferase (ChAT) and protein gene product 9.5 (PGP 9.5), α-bungarotoxin (α-BT) and PCR with primers for amplification of cDNA encoding TH and dopamine-β-hydroxylase (DBH). TH-positive nerve fibers were abundant throughout the myenteric plexus and localized on about 14% of α-BT-labelled motor endplates differing from VAChT-positive vagal nerve terminals. TH-positive perikarya represented a subpopulation of only about 2.8% of all PGP 9.5-positive myenteric neurons. Analysis of mRNA showed both TH and DBH transcripts in the mouse esophagus. As ChAT-positive neurons in the compact formation of the nucleus ambiguus were negative for TH, the TH-positive nerve varicosities on motor endplates are presumably of enteric origin, although a sympathetic origin cannot be excluded. In the medulla oblongata, the cholinergic ambiguus neurons were densely supplied with TH-positive varicosities. Thus, catecholamines may modulate vagal motor innervation of esophageal-striated muscles not only at the peripheral level via enteric co-innervation but also at the central level via projections to the nucleus ambiguus. As Parkinson's disease, with a loss of central dopaminergic neurons, also affects the enteric nervous system and dysphagia is prevalent in patients with this disease, investigation of intrinsic catecholamines in the esophagus may

  4. Interactive effects among several stimulus parameters on the responses of striate cortical complex cells.

    PubMed

    Gawne, T J; Richmond, B J; Optican, L M

    1991-08-01

    1. Although neurons within the visual system are often described in terms of their responses to particular patterns such as bars and edges, they are actually sensitive to many different stimulus features, such as the luminances making up the patterns and the duration of presentation. Many different combinations of stimulus parameters can result in the same neuronal response, raising the problem of how the nervous system can extract information about visual stimuli from such inherently ambiguous responses. It has been shown that complex cells transmit significant amounts of information in the temporal modulation of their responses, raising the possibility that different stimulus parameters are encoded in different aspects of the response. To find out how much information is actually available about individual stimulus parameters, we examined the interactions among three stimulus parameters in the temporally modulated responses of striate cortical complex cells. 2. Sixteen black and white patterns were presented to two awake monkeys at each of four luminance-combinations and five durations, giving a total of 320 unique stimuli. Complex cells were recorded in layers 2 and 3 of striate cortex, with the stimuli centered on the receptive fields as determined by mapping with black and white bars. 3. An analysis of variance (ANOVA) was applied to these data with the three stimulus parameters of pattern, the luminance-combinations, and duration as the independent variables. The ANOVA was repeated with the magnitude and three different aspects of the temporal modulation of the response as the dependent variables. For the 19 neurons studied, many of the interactions between the different stimulus parameters were statistically significant. For some response measures the interactions accounted for more than one-half of the total response variance. 4. We also analyzed the stimulus-response relationships with the use of information theoretical techniques. We defined input codes

  5. Detection of a troponin I-like protein in non-striated muscle of the tardigrades (water bears).

    PubMed

    Obinata, Takashi; Ono, Kanako; Ono, Shoichiro

    2011-03-01

    Tardigrades, also known as water bears, have somatic muscle fibers that are responsible for movement of their body and legs. These muscle fibers contain thin and thick filaments in a non-striated pattern. However, the regulatory mechanism of muscle contraction in tardigrades is unknown. In the absence of extensive molecular and genomic information, we detected a protein of 31 kDa in whole lysates of tardigrades that cross-reacted with the antibody raised against nematode troponin I (TnI). TnI is a component of the troponin complex that regulates actin-myosin interaction in a Ca(2+)-dependent and actin-linked manner. This TnI-like protein was co-extracted with actin in a buffer containing ATP and EGTA, which is known to induce relaxation of a troponin-regulated contractile system. The TnI-like protein was specifically expressed in the somatic muscle fibers in adult animals and partially co-localized with actin filaments in a non-striated manner. Interestingly, the pharyngeal muscle did not express this protein. These observations suggest that the non-striated somatic muscle of tardigrades has an actin-linked and troponin-regulated system for muscle contraction.

  6. Two dust populations of particle fragments in the striated tail of Comet MRKOS 1957 V

    NASA Technical Reports Server (NTRS)

    Sekanina, Z.; Farrell, J. A.

    1982-01-01

    The striated tail of Comet Mrkos 1957 V is investigated. The formation and motions of the striae are described by the same particle-fragmentation model that has been successfully applied to Comet West. Two new kinds of striae are discovered, one made of absorbing particles and the other of essentially nonabsorbing ones. The grains appear to range in size from 0.1 and 0.3 micron. Tentative evidence is found for an excess of dielectric particles with radii near 0.1 micron, whereas among absorbing grains such sizes are relatively scarce. These results illustrate a high degree of sensitivity of the brightness variation along a stria to the particle size distribution. The regular spacing of the bursts of parent particles suggests that all the striae originated in three emission areas on the comet's nucleus rotating with a period of 19.7 hr. The apparent pairing of striae in the tail is a by-product of the existence of more than one discrete source on the nucleus surface and of the different lifetimes of the parent particles.

  7. Two dust populations of particle fragments in the striated tail of Comet Mrkos 1957 V

    SciTech Connect

    Sekanina, Z.; Farrell, J.A.

    1982-12-01

    A total of 26 striae in the dust tail of Comet Mrkos 1957 V is investigated on five small-scale photographs taken 14--17 August 1957. The dynamical parameters of the striae are determined on the premise that these formations are products of the ejection of dust particles that subsequently break up in the tail. We establish the existence of two kinds of striae, consisting of submicron-sized particle fragments made of strongly absorbing and essentially dielectric materials. Although particles in the striae of both kinds are apparently restricted to sizes between 0.1 and 0.3 ..mu..m, inferred size distribution functions of the two dust populations are quite different. A calculated sequence of ejection times indicates that the striae originated in three isolated emission areas on the nucleus rotating with a 19.7-hr period. The discrete dust sources also account for an observed ''doublet'' structure of the striated pattern. We point out differences between the dust tails of Comets West 1976 VI and Mrkos and compare the particle-fragmentation model with a hypothesis that advocates a strong coupling between charged dust and comet plasma.

  8. Increased cytosolic androgen receptor binding in rat striated muscle following denervation and disuse

    NASA Technical Reports Server (NTRS)

    Bernard, P. A.; Fishman, P. S.; Max, S. R.; Rance, N. E.

    1984-01-01

    The effects of denervation and disuse on cytosolic androgen receptor binding by rat striated muscle are investigated. Denervation of the extensor digitorum longus and tibialis anterior muscles caused by a 40-50-percent increase in cytosolic androgen receptor concentration with no change in apparent binding affinity. This effect was evident at 6 h postdenervation, maximal at 24 h, and declined to 120 percent of the control level 72 h after denervation. A 40-percent increase in cytosolic androgen receptor concentration was also noted 24 hr after denervation of the hormone-sensitive levator ani muscle. The effect of denervation on androgen receptors was blocked by in vivo injection of cycloheximide; therefore, de novo receptor synthesis probably is not involved in the observed increase. Disuse, produced by subperineurial injection of tetrodotoxin into the tibial and common peroneal branches of the sciatic nerve, mimicked the effect of denervation on androgen receptor binding, suggesting that neuromuscular activity is important in regulation of receptor concentration. Possible mechanisms subserving this effect are discussed.

  9. Dietary Fish Oil Blocks the Microcirculatory Manifestations of Ischemia- Reperfusion Injury in Striated Muscle in Hamsters

    NASA Astrophysics Data System (ADS)

    Lehr, Hans-Anton; Hubner, Christoph; Nolte, Dirk; Kohlschutter, Alfried; Messmer, Konrad

    1991-08-01

    Epidemiologic observations and experimental studies have demonstrated a protective effect of dietary fish oil on the clinical manifestations of ischemia-reperfusion injury. To investigate the underlying mechanisms, we used the dorsal skinfold chamber model for intravital fluorescence microscopy of the microcirculation in striated muscle of awake hamsters. In control hamsters (n = 7), reperfusion after a 4-hr pressure-induced ischemia to the muscle tissue elicited the adhesion of fluorescently stained leukocytes to the endothelium of postcapillary venules, capillary obstruction, and the breakdown of endothelial integrity. These microvascular manifestations of ischemia-reperfusion injury were significantly attenuated in animals (n = 7) when fed with a fish oil-enriched diet for 4 weeks prior to the experiments. In leukocyte total lipids, the fish oil diet resulted in a substantial displacement of arachidonic acid, the precursor of the potent adhesionpromoting leukotriene (LT) B_4, by fish oil-derived eicosapentaenoic acid, the precursor of biologically less potent LTB_5, emphasizing the mediator role of LTB_4 in ischemia-reperfusion injury. These results suggest that the preservation of microvascular perfusion by dietary fish oil contributes to its protective effects on the clinical manifestations of ischemia-reperfusion injury.

  10. Minor sarcoplasmic reticulum membrane components that modulate excitation–contraction coupling in striated muscles

    PubMed Central

    Treves, Susan; Vukcevic, Mirko; Maj, Marcin; Thurnheer, Raphael; Mosca, Barbara; Zorzato, Francesco

    2009-01-01

    In striated muscle, activation of contraction is initiated by membrane depolarisation caused by an action potential, which triggers the release of Ca2+ stored in the sarcoplasmic reticulum by a process called excitation–contraction coupling. Excitation–contraction coupling occurs via a highly sophisticated supramolecular signalling complex at the junction between the sarcoplasmic reticulum and the transverse tubules. It is generally accepted that the core components of the excitation–contraction coupling machinery are the dihydropyridine receptors, ryanodine receptors and calsequestrin, which serve as voltage sensor, Ca2+ release channel, and Ca2+ storage protein, respectively. Nevertheless, a number of additional proteins have been shown to be essential both for the structural formation of the machinery involved in excitation–contraction coupling and for its fine tuning. In this review we discuss the functional role of minor sarcoplasmic reticulum protein components. The definition of their roles in excitation–contraction coupling is important in order to understand how mutations in genes involved in Ca2+ signalling cause neuromuscular disorders. PMID:19403606

  11. Static magnetic fields affect capillary flow of red blood cells in striated skin muscle.

    PubMed

    Brix, Gunnar; Strieth, Sebastian; Strelczyk, Donata; Dellian, Marc; Griebel, Jürgen; Eichhorn, Martin E; Andrā, Wilfried; Bellemann, Matthias E

    2008-01-01

    Blood flowing in microvessels is one possible site of action of static magnetic fields (SMFs). We evaluated SMF effects on capillary flow of red blood cells (RBCs) in unanesthetized hamsters, using a skinfold chamber technique for intravital fluorescence microscopy. By this approach, capillary RBC velocities (v(RBC)), capillary diameters (D), arteriolar diameters (D(art)), and functional vessel densities (FVD) were measured in striated skin muscle at different magnetic flux densities. Exposure above a threshold level of about 500 mT resulted in a significant (P < 0.001) reduction of v(RBC) in capillaries as compared to the baseline value. At the maximum field strength of 587 mT, v(RBC) was reduced by more than 40%. Flow reduction was reversible when the field strength was decreased below the threshold level. In contrast, mean values determined at different exposure levels for the parameters D, D(art), and FVD did not vary by more than 5%. Blood flow through capillary networks is affected by strong SMFs directed perpendicular to the vessels. Since the influence of SMFs on blood flow in microvessels directed parallel to the field as well as on collateral blood supply could not be studied, our findings should be carefully interpreted with respect to the setting of safety guidelines.

  12. Magnetization ac loss reduction in HTS CORC® cables made of striated coated conductors

    NASA Astrophysics Data System (ADS)

    Vojenčiak, M.; Kario, A.; Ringsdorf, B.; Nast, R.; van der Laan, D. C.; Scheiter, J.; Jung, A.; Runtsch, B.; Gömöry, F.; Goldacker, W.

    2015-10-01

    High temperature superconductors (HTSs), like for instance REBCO (RE = rare earth) coated conductors, are of high potential for building large superconducting magnets. Some magnets, such as accelerator magnets, require the use of superconducting cables to allow fast ramping, and low magnetization loss to mitigate field quality issues. One of the methods to lower ac loss is to divide the superconducting layer in the tape into filaments. In this paper, conductors with copper stabilization for practical applications are laser scribed into narrow filaments. Striated tapes are then wound into conductor on round core (CORC®) cables. The critical current and magnetization ac loss of single tapes were measured. We found that the stabilizing copper layer causes difficulties for laser scribing. The degradation of the critical current is more pronounced than in the case of non-stabilized tapes. The selection of the number of filaments is therefore a compromise between critical current degradation and reduction of ac loss. Based on the results obtained from single tape experiments, the optimum number of filaments in 4 mm wide tapes was chosen, and CORC® cables with 2, 3 and 4 layers of tapes with and without filaments were manufactured. Magnetization ac loss measurements at 77 K showed a reduction of ac loss in the cables with filaments. This reduction corresponds almost to the number of filaments. Measurement at different frequencies also showed that the coupling loss in CORC® cables with a short twist-pitch is relatively small in comparison to hysteretic loss.

  13. Isoforms of gelsolin from lobster striated muscles differ in calcium-dependence.

    PubMed

    Unger, Andreas; Brunne, Bianka; Hinssen, Horst

    2013-08-01

    Two distinct isoforms of the Ca-dependent actin filament severing protein gelsolin were identified in cross-striated muscles of the American lobster. The variants (termed LG1 and LG2) differ by an extension of 18 AA at the C-terminus of LG1, and by two substitutions at AA735 and AA736, the two C-terminal amino acids of LG2. Functional comparison of the isolated and purified proteins revealed gelsolin-typical properties for both with differences in Ca(2+)-sensitivity, LG2 being activated at significant lower Ca-concentration than LG1: Half maximal activation for both filament severing and G-actin binding was ∼4×10(-7)M Ca(2+) for LG2 vs. ∼2×10(-6)M Ca(2+) for LG1. This indicates a differential activation for the two isoproteins in vivo where they are present in almost equal amounts in the muscle cell. Structure prediction modeling on the basis of the known structure of mammalian gelsolin shows that LG2 lacks the C-terminal alpha-helix which is involved in contact formation between domains G6 and G2. In both mammalian gelsolin and LG1, this "latch bridge" is assumed to play a critical role in Ca(2+)-activation by keeping gelsolin in a closed, inactive conformation at low [Ca(2+)]. In LG2, the reduced contact between G6 and G2 may be responsible for its activation at low Ca(2+)-concentration.

  14. Characterization of beta-connectin (titin 2) from striated muscle by dynamic light scattering.

    PubMed Central

    Higuchi, H; Nakauchi, Y; Maruyama, K; Fujime, S

    1993-01-01

    Connectin (titin) is a large filamentous protein (single peptide) with a molecular mass of approximately 3 MDa, contour length approximately 900 nm, and diameter approximately 4 nm, and resides in striated muscle. Connectin links the thick filaments to the Z-lines in a sarcomere and produces a passive elastic force when muscle fiber is stretched. The aim of this study is to elucidate some aspects of physical properties of isolated beta-connectin (titin 2), a proteolytic fragment of connectin, by means of dynamic light-scattering (DLS) spectroscopy. The analysis of DLS spectra for beta-connectin gave the translational diffusion coefficient of 3.60 x 10(-8) cm2/s at 10 degrees C (or the hydrodynamic radius of 44.1 nm), molecular mass little smaller than 3.0 MDa (for a literature value of sedimentation coefficient), the root-mean-square end-to-end distance of 163 nm (or the radius of gyration of 66.6 nm), and the Kuhn segment number of 30 and segment length of 30 nm (or the persistence length of 15 nm). These results permitted to estimate the flexural rigidity of 6.0 x 10(-20) dyn x cm2 for filament bending, and the elastic constant of 7 dyn/cm for extension of one persistence length. Based on a simple model, implications of the present results in muscle physiology are discussed. Images FIGURE 1 PMID:8298020

  15. Revealing T-Tubules in Striated Muscle with New Optical Super-Resolution Microscopy Techniquess

    PubMed Central

    Clowsley, Alexander H.; Munro, Michelle; Hou, Yufeng; Crossman, David J.

    2014-01-01

    The t-tubular system plays a central role in the synchronisation of calcium signalling and excitation-contraction coupling in most striated muscle cells. Light microscopy has been used for imaging t-tubules for well over 100 years and together with electron microscopy (EM), has revealed the three-dimensional complexities of the t-system topology within cardiomyocytes and skeletal muscle fibres from a range of species. The emerging super-resolution single molecule localisation microscopy (SMLM) techniques are offering a near 10-fold improvement over the resolution of conventional fluorescence light microscopy methods, with the ability to spectrally resolve nanometre scale distributions of multiple molecular targets. In conjunction with the next generation of electron microscopy, SMLM has allowed the visualisation and quantification of intricate t-tubule morphologies within large areas of muscle cells at an unprecedented level of detail. In this paper, we review recent advancements in the t-tubule structural biology with the utility of various microscopy techniques. We outline the technical considerations in adapting SMLM to study t-tubules and its potential to further our understanding of the molecular processes that underlie the sub-micron scale structural alterations observed in a range of muscle pathologies. PMID:26913143

  16. Differential expression of beta 1 integrins in nonneoplastic smooth and striated muscle cells and in tumors derived from these cells.

    PubMed Central

    Mechtersheimer, G.; Barth, T.; Quentmeier, A.; Möller, P.

    1994-01-01

    Integrins are a superfamily of transmembrane alpha beta heterodimers that play an important role in cell-matrix and cell-cell interactions by acting as receptors for extracellular matrix proteins and for cell adhesion molecules. Using monoclonal antibodies against beta 1, alpha 1 to alpha 6, and alpha v subunits, the in situ distribution pattern of beta 1 integrins was examined immunohistochemically in nonneoplastic smooth and striated muscle cells and in their tumors. Nonneoplastic smooth muscle cells were beta 1+, alpha 1+, alpha 3+, alpha v+ and, in diverse localizations, also alpha 5+ or even alpha 6+. The expression of the beta 1 chain was conserved in all leiomyomas and leiomyosarcomas. The distribution pattern of the alpha subunits by contrast underwent several changes during malignant transformation of smooth muscle cells. These alterations consisted in a neoexpression of alpha 2, alpha 4, and alpha 6 as well as in an abnormal abrogation of alpha 1 and alpha 3 in some leiomyosarcomas. Except for the absence of alpha 5 in the majority of epithelioid leiomyosarcomas, expression of the alpha 5 and alpha v subunits was mainly conserved. In addition, tumors with epithelioid differentiation differed from typical cases by the absence of alpha 1 and the simultaneous presence of alpha 4. Adult striated muscle cells were beta 1+ but alpha 1- to alpha 6- and alpha v-, whereas fetal striated muscle cells were not only beta 1+ but also alpha 3+/-, alpha 4+/-, alpha 5+ and alpha 6+. In all rhabdomyosarcomas the expression of beta 1 was retained. Furthermore, the majority of cases showed the expression of one or more alpha subunits most of which, ie, alpha 4, alpha 5, and alpha 6, were also found in fetal striated muscle cells. In conclusion, beta 1 integrins exhibited a differential expression pattern along the two lines of myogenic differentiation. This integrin profile underwent characteristic changes during malignant transformation. Nevertheless, the compiled

  17. The Intriguing Dual Lattices of the Myosin Filaments in Vertebrate Striated Muscles: Evolution and Advantage

    PubMed Central

    Luther, Pradeep K.; Squire, John M.

    2014-01-01

    Myosin filaments in vertebrate striated muscle have a long roughly cylindrical backbone with cross-bridge projections on the surfaces of both halves except for a short central bare zone. In the middle of this central region the filaments are cross-linked by the M-band which holds them in a well-defined hexagonal lattice in the muscle A-band. During muscular contraction the M-band-defined rotation of the myosin filaments around their long axes influences the interactions that the cross-bridges can make with the neighbouring actin filaments. We can visualise this filament rotation by electron microscopy of thin cross-sections in the bare-region immediately adjacent to the M-band where the filament profiles are distinctly triangular. In the muscles of teleost fishes, the thick filament triangular profiles have a single orientation giving what we call the simple lattice. In other vertebrates, for example all the tetrapods, the thick filaments have one of two orientations where the triangles point in opposite directions (they are rotated by 60° or 180°) according to set rules. Such a distribution cannot be developed in an ordered fashion across a large 2D lattice, but there are small domains of superlattice such that the next-nearest neighbouring thick filaments often have the same orientation. We believe that this difference in the lattice forms can lead to different contractile behaviours. Here we provide a historical review, and when appropriate cite recent work related to the emergence of the simple and superlattice forms by examining the muscles of several species ranging back to primitive vertebrates and we discuss the functional differences that the two lattice forms may have. PMID:25478994

  18. The intriguing dual lattices of the Myosin filaments in vertebrate striated muscles: evolution and advantage.

    PubMed

    Luther, Pradeep K; Squire, John M

    2014-01-01

    Myosin filaments in vertebrate striated muscle have a long roughly cylindrical backbone with cross-bridge projections on the surfaces of both halves except for a short central bare zone. In the middle of this central region the filaments are cross-linked by the M-band which holds them in a well-defined hexagonal lattice in the muscle A-band. During muscular contraction the M-band-defined rotation of the myosin filaments around their long axes influences the interactions that the cross-bridges can make with the neighbouring actin filaments. We can visualise this filament rotation by electron microscopy of thin cross-sections in the bare-region immediately adjacent to the M-band where the filament profiles are distinctly triangular. In the muscles of teleost fishes, the thick filament triangular profiles have a single orientation giving what we call the simple lattice. In other vertebrates, for example all the tetrapods, the thick filaments have one of two orientations where the triangles point in opposite directions (they are rotated by 60° or 180°) according to set rules. Such a distribution cannot be developed in an ordered fashion across a large 2D lattice, but there are small domains of superlattice such that the next-nearest neighbouring thick filaments often have the same orientation. We believe that this difference in the lattice forms can lead to different contractile behaviours. Here we provide a historical review, and when appropriate cite recent work related to the emergence of the simple and superlattice forms by examining the muscles of several species ranging back to primitive vertebrates and we discuss the functional differences that the two lattice forms may have. PMID:25478994

  19. Digital image analysis of striated skeletal muscle tissue injury during reperfusion after induced ischemia

    NASA Astrophysics Data System (ADS)

    Rosero Salazar, Doris Haydee; Salazar Monsalve, Liliana

    2015-01-01

    Conditions such as surgical procedures or vascular diseases produce arterial ischemia and reperfusion injuries, which generate changes in peripheral tissues and organs, for instance, in striated skeletal muscle. To determine such changes, we conducted an experimental method in which 42 male Wistar rat were selected, to be undergone to tourniquet application on the right forelimb and left hind limb, to induce ischemia during one and three hours, followed by reperfusion periods starting at one hour and it was prolonged up to 32 days. Extensor carpi radialis longus and soleus respectively, were obtained to be processed for histochemical and morphometric analysis. By means of image processing and detection of regions of interest, variations of areas occupied by muscle fibers and intramuscular extracellular matrix (IM-ECM) throughout reperfusion were observed. In extensor carpi radialis longus, results shown reduction in the area occupied by muscle fibers; this change is significant between one hour and three hours ischemia followed by 16 hours, 48 hours and 32 days reperfusión (p˂0.005). To compare only periods of reperfusión that continued to three hours ischemia, were found significant differences, as well. For area occupied by IM-ECM, were identified increments in extensor carpi radialis longus by three hours ischemia and eight to 16 days reperfusion; in soleus, was observed difference by one hour ischemia with 42 hours reperfusion, and three hours ischemia followed by four days reperfusion (p˂0.005). Skeletal muscle develops adaptive changes in longer reperfusion, to deal with induced injury. Descriptions beyond 32 days reperfusion, can determine recovering normal pattern.

  20. Lessons from mammalian hibernators: molecular insights into striated muscle plasticity and remodeling.

    PubMed

    Tessier, Shannon N; Storey, Kenneth B

    2016-05-01

    Striated muscle shows an amazing ability to adapt its structural apparatus based on contractile activity, loading conditions, fuel supply, or environmental factors. Studies with mammalian hibernators have identified a variety of molecular pathways which are strategically regulated and allow animals to endure multiple stresses associated with the hibernating season. Of particular interest is the observation that hibernators show little skeletal muscle atrophy despite the profound metabolic rate depression and mechanical unloading that they experience during long weeks of torpor. Additionally, the cardiac muscle of hibernators must adjust to low temperature and reduced perfusion, while the strength of contraction increases in order to pump cold, viscous blood. Consequently, hibernators hold a wealth of knowledge as it pertains to understanding the natural capacity of myocytes to alter structural, contractile and metabolic properties in response to environmental stimuli. The present review outlines the molecular and biochemical mechanisms which play a role in muscular atrophy, hypertrophy, and remodeling. In this capacity, four main networks are highlighted: (1) antioxidant defenses, (2) the regulation of structural, contractile and metabolic proteins, (3) ubiquitin proteosomal machinery, and (4) macroautophagy pathways. Subsequently, we discuss the role of transcription factors nuclear factor (erythroid-derived 2)-like 2 (Nrf2), Myocyte enhancer factor 2 (MEF2), and Forkhead box (FOXO) and their associated posttranslational modifications as it pertains to regulating each of these networks. Finally, we propose that comparing and contrasting these concepts to data collected from model organisms able to withstand dramatic changes in muscular function without injury will allow researchers to delineate physiological versus pathological responses. PMID:26982616

  1. Large-scale Models Reveal the Two-component Mechanics of Striated Muscle

    PubMed Central

    Jarosch, Robert

    2008-01-01

    This paper provides a comprehensive explanation of striated muscle mechanics and contraction on the basis of filament rotations. Helical proteins, particularly the coiled-coils of tropomyosin, myosin and α-actinin, shorten their H-bonds cooperatively and produce torque and filament rotations when the Coulombic net-charge repulsion of their highly charged side-chains is diminished by interaction with ions. The classical “two-component model” of active muscle differentiated a “contractile component” which stretches the “series elastic component” during force production. The contractile components are the helically shaped thin filaments of muscle that shorten the sarcomeres by clockwise drilling into the myosin cross-bridges with torque decrease (= force-deficit). Muscle stretch means drawing out the thin filament helices off the cross-bridges under passive counterclockwise rotation with torque increase (= stretch activation). Since each thin filament is anchored by four elastic α-actinin Z-filaments (provided with force-regulating sites for Ca2+ binding), the thin filament rotations change the torsional twist of the four Z-filaments as the “series elastic components”. Large scale models simulate the changes of structure and force in the Z-band by the different Z-filament twisting stages A, B, C, D, E, F and G. Stage D corresponds to the isometric state. The basic phenomena of muscle physiology, i. e. latency relaxation, Fenn-effect, the force-velocity relation, the length-tension relation, unexplained energy, shortening heat, the Huxley-Simmons phases, etc. are explained and interpreted with the help of the model experiments. PMID:19330099

  2. Comparative studies on troponin, a Ca²⁺-dependent regulator of muscle contraction, in striated and smooth muscles of protochordates.

    PubMed

    Obinata, Takashi; Sato, Naruki

    2012-01-01

    Troponin is well known as a Ca(2+)-dependent regulator of striated muscle contraction and it has been generally accepted that troponin functions as an inhibitor of muscle contraction or actin-myosin interaction at low Ca(2+) concentrations, and Ca(2+) at higher concentrations removes the inhibitory action of troponin. Recently, however, troponin became detectable in non-striated muscles of several invertebrates and in addition, unique troponin that functions as a Ca(2+)-dependent activator of muscle contraction has been detected in protochordate animals, although troponin in vertebrate striated muscle is known as an inhibitor of the contraction in the absence of a Ca(2+). Further studies on troponin in invertebrate muscle, especially in non-striated muscle, would provide new insight into the evolution of regulatory systems for muscle contraction and diverse function of troponin and related proteins. The methodology used for preparation and characterization of functional properties of protochordate striated and smooth muscles will be helpful for further studies of troponin in other invertebrate animals.

  3. Potential dynamics of the human striate cortex cerebrum realistic neural network under the influence of an external signal

    NASA Astrophysics Data System (ADS)

    Melnikov, Leonid A.; Novosselova, Anna V.; Blinova, Nadejda V.; Vinitsky, Sergey I.; Serov, Vladislav V.; Bakutkin, Valery V.; Camenskich, T. G.; Guileva, E. V.

    2000-03-01

    In this work the numerical investigations of a potential dynamics of a neural network as the non-linear system and dynamics of the visual nerve which connect the eye retina receptors with the striate cortex cerebrum as the answer to the through-skin excitement of the eye retina by the electrical signal were realized. The visual evoked potential is the answer and characterizes the human brain state over the structures retina state and the conduction of the visual nerve fibers. The results of these investigations were presented. Specific features of the neural network, such as the excitation and depression, we took into account too. The discussion about the model parameters, used at the time of the numerical investigation, was made. The comparative analysis of the retina potential data and the data of the external signal filing by the brain hemicerebrum visual centers was made too.

  4. Computed tomography of cerebral infarction along the distribution of the basal perforating arteries. Part 1. Striate arterial group

    SciTech Connect

    Takahashi, S.; Goto, K.; Fukasawa, H.; Kawata, Y.; Uemura, K.; Suzuki, K.

    1985-04-01

    Computed tomographic (CT) manifestations of cerebral infarction along the distribution of the basal perforating arteries were reviewed in correlation with cerebral angiography. Infarcts in the territories of perforators were demonstrated individually based on knowledge of their three dimensional distribution as demonstrated by microangiography of cadavers. In Part I of the study, the areas supplied by the medial (MSA) and lateral striate arteries (LSA) were examined. Infarction along the branches of the MSA usually involved the antero-inferior portion of the corpus striatum, immediately posterolateral to the most inferior part of the frontal horn of the lateral ventricle. Infarcts along the branches of the LSA abutted the territory of the MSA posteriorly and superiorly and involved the posterolateral region of the corpus striatum. Clinical and neuroradiological correlations are discussed.

  5. Co-localization of glutamic acid decarboxylase and vesicular GABA transporter in cytochrome oxidase patches of macaque striate cortex.

    PubMed

    Adams, Daniel L; Economides, John R; Horton, Jonathan C

    2015-01-01

    The patches in primary visual cortex constitute hot spots of metabolic activity, manifested by enhanced levels of cytochrome oxidase (CO) activity. They are also labeled preferentially by immunostaining for glutamic acid decarboxylase (GAD), γ-aminobutyric acid (GABA), and parvalbumin. However, calbindin shows stronger immunoreactivity outside patches. In light of this discrepancy, the distribution of the vesicular GABA transporter (VGAT) was examined in striate cortex of two normal macaques. VGAT immunoreactivity was strongest in layers 4B, 4Cα, and 5. In tangential sections, the distribution of CO, GAD, and VGAT was compared in layer 2/3. There was a close match between all three labels. This finding indicates that GABA synthesis is enriched in patches, and that inhibitory synapses are more active in patches than interpatches. PMID:26579566

  6. Relationship between large-aperture optical components of striated surface shape and focal spot characteristics in the far-field

    NASA Astrophysics Data System (ADS)

    Lei, Zemin; Sun, Xiaoyan; Yin, Xianhua; Lv, Fengnian; Zhang, Zhen; Lu, Xingqiang; Fan, Dianyuan

    2015-07-01

    Surface shape of optical components is an essential factor of the laser beam quality. Different types of surface correspond to different characteristics of the laser focal spot. Striated surface shape is one of common and typical cases of optical component surfaces in laser facilities, which have attracted great attention. For learning the impact of the component on focal spot in the far-field, a model component with the similar features was introduced in the study. Intensity distributions of focal spot in the far-field was simulated after laser beam went through the model component. Effects of the modulation depth and the modulation period on spot morphology were presented. Furthermore, the relations between these optical specifications and focal spots with some requirements had been analyzed. The results can enhance our understanding about striae degrees of optical elements and have reference values to guide the processing and the use of large-aperture components correctly.

  7. Effect of halothane on isometric twitch and tetanus response and the associated heat production in striated muscle of frogs.

    PubMed

    Price, K A; Matsumoto, Y; Frederickson, E L

    1975-01-01

    The purpose of these investigations was to determine the effect of halothane on isometric contraction of striated muscle and to measure the associated heat production. This basic information is necessary before studies more directly relating to malignant hyperthermia are undertaken. Sartorius muscles were isolate from Rana pipiens during winter and summer months. It appears from these experiments that there is a prolongation of the relaxation phase of the twitch and tetanus responses with low concentrations of halothane, with a more diffuse effect on the contractile process evident at higher administered concentrations. The results of heat measurements, using a sensitive thermopile-galvanometer system, are compatible with the hypotheses that this effect on relaxation could result from either an interference with calcium reuptake by the sarcoplasmic reticulum or an increased affinity of the troponintropomyosin complex for available calcium. PMID:1080024

  8. Evolution of the regulatory control of vertebrate striated muscle: the roles of troponin I and myosin binding protein-C.

    PubMed

    Shaffer, Justin F; Gillis, Todd E

    2010-08-01

    Troponin I (TnI) and myosin binding protein-C (MyBP-C) are key regulatory proteins of contractile function in vertebrate muscle. TnI modulates the Ca(2+) activation signal, while MyBP-C regulates cross-bridge cycling kinetics. In vertebrates, each protein is distributed as tissue-specific paralogs in fast skeletal (fs), slow skeletal (ss), and cardiac (c) muscles. The purpose of this study is to characterize how TnI and MyBP-C have changed during the evolution of vertebrate striated muscle and how tissue-specific paralogs have adapted to different physiological conditions. To accomplish this we have completed phylogenetic analyses using the amino acid sequences of all known TnI and MyBP-C isoforms. This includes 99 TnI sequences (fs, ss, and c) from 51 different species and 62 MyBP-C sequences from 26 species, with representatives from each vertebrate group. Results indicate that the role of protein kinase A (PKA) and protein kinase C (PKC) in regulating contractile function has changed during the evolution of vertebrate striated muscle. This is reflected in an increased number of phosphorylatable sites in cTnI and cMyBP-C in endothermic vertebrates and the loss of two PKC sites in fsTnI in a common ancestor of mammals, birds, and reptiles. In addition, we find that His(132), Val(134), and Asn(141) in human ssTnI, previously identified as enabling contractile function during cellular acidosis, are present in all vertebrate cTnI isoforms except those from monotremes, marsupials, and eutherian mammals. This suggests that the replacement of these residues with alternative residues coincides with the evolution of endothermy in the mammalian lineage.

  9. The myosin interacting-heads motif is present in the relaxed thick filament of the striated muscle of scorpion.

    PubMed

    Pinto, Antonio; Sánchez, Fredi; Alamo, Lorenzo; Padrón, Raúl

    2012-12-01

    Electron microscopy (EM) studies of 2D crystals of smooth muscle myosin molecules have shown that in the inactive state the two heads of a myosin molecule interact asymmetrically forming a myosin interacting-heads motif. This suggested that inactivation of the two heads occurs by blocking of the actin-binding site of one (free head) and the ATP hydrolysis site of the other (blocked head). This motif has been found by EM of isolated negatively stained myosin molecules of unregulated (vertebrate skeletal and cardiac muscle) and regulated (invertebrate striated and vertebrate smooth muscle) myosins, and nonmuscle myosin. The same motif has also been found in 3D-reconstructions of frozen-hydrated (tarantula, Limulus, scallop) and negatively stained (scallop, vertebrate cardiac) isolated thick filaments. We are carrying out studies of isolated thick filaments from other species to assess how general this myosin interacting-heads motif is. Here, using EM, we have visualized isolated, negatively stained thick filaments from scorpion striated muscle. We modified the iterative helical real space reconstruction (IHRSR) method to include filament tilt, and band-pass filtered the aligned segments before averaging, achieving a 3.3 nm resolution 3D-reconstruction. This reconstruction revealed the presence of the myosin interacting-heads motif (adding to evidence that is widely spread), together with 12 subfilaments in the filament backbone. This demonstrates that conventional negative staining and imaging can be used to detect the presence of the myosin interacting-heads motif in helically ordered thick filaments from different species and muscle types, thus avoiding the use of less accessible cryo-EM and low electron-dose procedures. PMID:22982253

  10. Gene expression analyses of essential catch factors in the smooth and striated adductor muscles of larval, juvenile and adult great scallop (Pecten maximus).

    PubMed

    Andersen, Øivind; Torgersen, Jacob S; Pagander, Helene H; Magnesen, Thorolf; Johnston, Ian A

    2009-01-01

    The scallop adductor muscle consists of striated fibres responsible for the fast closure of the shells, and smooth fibres able to maintain tension in a prolonged state of contraction called catch. Formation of the force-bearing catch linkages has been demonstrated to be initiated by dephosphorylation of the key catch-regulating factor twitchin by a calcineurin-like phosphatase, while the involvement of other thick filament proteins is uncertain. Here we report on the development of catchability of the adductor smooth muscle in the great scallop (Pecten maximus) by analysing the spatio-temporal gene expression patterns of the myosin regulatory light chain (MLCr), twitchin, myorod and calcineurin using whole mount in situ hybridization and real-time quantitative PCR. The MLCr signal was identified in the retractor and adductor muscles of the pediveliger larvae, and the juvenile and adult scallop displayed abundant mRNA levels of MLCr in the smooth and striated adductor muscles. Twitchin was mainly expressed in the smooth adductor muscle during metamorphosis, whereas the adult striated adductor muscle contained seven-folds higher twitchin mRNA levels compared to the smooth portion. Calcineurin expression predominated in the gonads and in the smooth adductor, and five-folds higher mRNA levels were measured in the smooth than in the striated fibres at the adult stage. In contrast to the other genes examined, the expression of myorod was confined to the smooth adductor muscle suggesting that myorod plays a permissive role in the molluscan catch muscles, which are first required at the vulnerable settlement stage as a component of the predator defence system.

  11. Macrophage density in pharyngeal and laryngeal muscles greatly exceeds that in other striated muscles: an immunohistochemical study using elderly human cadavers

    PubMed Central

    Rhee, Sunki; Kitamura, Kei; Masaaki, Kasahara; Katori, Yukio; Murakami, Gen; Abe, Shin-ichi

    2016-01-01

    Macrophages play an important role in aging-related muscle atrophy (i.e., sarcopenia). We examined macrophage density in six striated muscles (cricopharyngeus muscle, posterior cricoarytenoideus muscle, genioglossus muscle, masseter muscle, infraspinatus muscle, and external anal sphincter). We examined 14 donated male cadavers and utilized CD68 immunohistochemistry to clarify macrophage density in muscles. The numbers of macrophages per striated muscle fiber in the larynx and pharynx (0.34 and 0.31) were 5–6 times greater than those in the tongue, shoulder, and anus (0.05–0.07) with high statistical significance. Thick muscle fibers over 80 µm in diameter were seen in the pharynx, larynx, and anal sphincter of two limited specimens. Conversely, in the other sites or specimens, muscle fibers were thinner than 50 µm. We did not find any multinuclear muscle cells suggestive of regeneration. At the beginning of the study, we suspected that mucosal macrophages might have invaded into the muscle layer of the larynx and pharynx, but we found no evidence of inflammation in the mucosa. Likewise, the internal anal sphincter (a smooth muscle layer near the mucosa) usually contained fewer macrophages than the external sphincter. The present result suggest that, in elderly men, thinning and death of striated muscle fibers occur more frequently in the larynx and pharynx than in other parts of the body. PMID:27722010

  12. Geologic continuous casting below continental and deep-sea detachment faults and at the striated extrusion of Sacsayhuaman, Peru

    USGS Publications Warehouse

    Spencer, J.E.

    1999-01-01

    In the common type of industrial continuous casting, partially molten metal is extruded from a vessel through a shaped orifice called a mold in which the metal assumes the cross-sectional form of the mold as it cools and solidifies. Continuous casting can be sustained as long as molten metal is supplied and thermal conditions are maintained. I propose that a similar process produced parallel sets of grooves in three geologic settings, as follows: (1) corrugated metamorphic core complexes where mylonized mid-crustal rocks were exhumed by movement along low-angle normal faults known as detachment faults; (2) corrugated submarine surfaces where ultramafic and mafic rocks were exhumed by normal faulting within oceanic spreading centers; and (3) striated magma extrusions exemplified by the famous grooved outcrops at the Inca fortress of Sacsayhuaman in Peru. In each case, rocks inferred to have overlain the corrugated surface during corrugation genesis molded and shaped a plastic to partially molten rock mass as it was extruded from a moderate- to high-temperature reservoir.

  13. Overexpression of Striated Muscle Activator of Rho Signaling (STARS) Increases C2C12 Skeletal Muscle Cell Differentiation

    PubMed Central

    Wallace, Marita A.; Della Gatta, Paul A.; Ahmad Mir, Bilal; Kowalski, Greg M.; Kloehn, Joachim; McConville, Malcom J.; Russell, Aaron P.; Lamon, Séverine

    2016-01-01

    Background: Skeletal muscle growth and regeneration depend on the activation of satellite cells, which leads to myocyte proliferation, differentiation and fusion with existing muscle fibers. Skeletal muscle cell proliferation and differentiation are tightly coordinated by a continuum of molecular signaling pathways. The striated muscle activator of Rho signaling (STARS) is an actin binding protein that regulates the transcription of genes involved in muscle cell growth, structure and function via the stimulation of actin polymerization and activation of serum-response factor (SRF) signaling. STARS mediates cell proliferation in smooth and cardiac muscle models; however, whether STARS overexpression enhances cell proliferation and differentiation has not been investigated in skeletal muscle cells. Results: We demonstrate for the first time that STARS overexpression enhances differentiation but not proliferation in C2C12 mouse skeletal muscle cells. Increased differentiation was associated with an increase in the gene levels of the myogenic differentiation markers Ckm, Ckmt2 and Myh4, the differentiation factor Igf2 and the myogenic regulatory factors (MRFs) Myf5 and Myf6. Exposing C2C12 cells to CCG-1423, a pharmacological inhibitor of SRF preventing the nuclear translocation of its co-factor MRTF-A, had no effect on myotube differentiation rate, suggesting that STARS regulates differentiation via a MRTF-A independent mechanism. Conclusion: These findings position STARS as an important regulator of skeletal muscle growth and regeneration. PMID:26903873

  14. Correction of Multiple Striated Muscles in Murine Pompe Disease Through Adeno-associated Virus-Mediated Gene Therapy

    PubMed Central

    Sun, Baodong; Young, Sarah P.; Li, Ping; Di, Chunhui; Brown, Talmage; Salva, Maia Z.; Li, Songtao; Bird, Andrew; Yan, Zhen; Auten, Richard; Hauschka, Stephen D.; Koeberl, Dwight D.

    2009-01-01

    Glycogen storage disease type II (GSD-II; Pompe disease; MIM 232300) stems from the deficiency of acid-α-glucosidase (GAA; acid maltase; EC 3.2.1.20), which primarily involves cardiac and skeletal muscles. We hypothesized that systemic administration of an adeno-associated virus (AAV) vector containing a muscle specific regulatory cassette could drive efficacious transgene expression in GAA-knockout (GAA-KO) mice. AAV2/8 vectors containing the muscle creatine kinase (CK1) or hybrid α-myosin heavy chain enhancer-/muscle creatine kinase enhancer-promoter (MHCK7) cassettes were compared. The CK1 reduced glycogen content by approximately 50% in the heart and quadriceps, in comparison to untreated GAA-KO mice, whereas the MHCK7 containing vector reduced glycogen content even further: >95% in heart and >75% in the diaphragm and quadriceps. Administration of the MHCK7-containing vector significantly increased striated muscle function as assessed by increased Rotarod times at 18 weeks post-injection, whereas the CK1-containing vector did not increase Rotarod performance. Transduction efficiency was evaluated with an AAV2/8 vector in which MHCK7 drives alkaline-phosphatase, revealing that many more myofibers were transduced in the quadriceps than in the gastrocnemius. An AAV2/9 vector containing the MHCK7 cassette corrected GAA deficiency in the skeletal muscles of the distal limb, including the gastrocnemius, extensor digitalis longus, and soleus; furthermore, glycogen accumulations were substantially cleared by hGAA expression therein. Importantly, type IIb myofibers in the extensor digitalis longus were transduced, thereby correcting a myofiber type that is unresponsive to enzyme replacement therapy. In summary, AAV8 and AAV9-pseudotyped vectors containing the MHCK7 regulatory cassette achieved enhanced efficacy in Pompe disease mice. PMID:18560415

  15. The “Goldilocks Zone” from a redox perspective—Adaptive vs. deleterious responses to oxidative stress in striated muscle

    PubMed Central

    Alleman, Rick J.; Katunga, Lalage A.; Nelson, Margaret A. M.; Brown, David A.; Anderson, Ethan J.

    2014-01-01

    Consequences of oxidative stress may be beneficial or detrimental in physiological systems. An organ system's position on the “hormetic curve” is governed by the source and temporality of reactive oxygen species (ROS) production, proximity of ROS to moieties most susceptible to damage, and the capacity of the endogenous cellular ROS scavenging mechanisms. Most importantly, the resilience of the tissue (the capacity to recover from damage) is a decisive factor, and this is reflected in the disparate response to ROS in cardiac and skeletal muscle. In myocytes, a high oxidative capacity invariably results in a significant ROS burden which in homeostasis, is rapidly neutralized by the robust antioxidant network. The up-regulation of key pathways in the antioxidant network is a central component of the hormetic response to ROS. Despite such adaptations, persistent oxidative stress over an extended time-frame (e.g., months to years) inevitably leads to cumulative damages, maladaptation and ultimately the pathogenesis of chronic diseases. Indeed, persistent oxidative stress in heart and skeletal muscle has been repeatedly demonstrated to have causal roles in the etiology of heart disease and insulin resistance, respectively. Deciphering the mechanisms that underlie the divergence between adaptive and maladaptive responses to oxidative stress remains an active area of research for basic scientists and clinicians alike, as this would undoubtedly lead to novel therapeutic approaches. Here, we provide an overview of major types of ROS in striated muscle and the divergent adaptations that occur in response to them. Emphasis is placed on highlighting newly uncovered areas of research on this topic, with particular focus on the mitochondria, and the diverging roles that ROS play in muscle health (e.g., exercise or preconditioning) and disease (e.g., cardiomyopathy, ischemia, metabolic syndrome). PMID:25278906

  16. (−)-EPICATECHIN IMPROVES MITOCHONDRIAL RELATED PROTEIN LEVELS AND AMELIORATES OXIDATIVE STRESS IN DYSTROPHIC DELTA SARCOGLYCAN NULL MOUSE STRIATED MUSCLE

    PubMed Central

    Ramirez-Sanchez, Israel; De los Santos, Sergio; Gonzalez-Basurto, Silvia; Canto, Patricia; Mendoza-Lorenzo, Patricia; Palma-Flores, Carlos; Ceballos-Reyes, Guillermo; Villarreal, Francisco; Zentella-Dehesa, Alejandro; Coral-Vazquez, Ramon

    2014-01-01

    Muscular dystrophies (MD) are a group of heterogeneous genetic disorders characterized by progressive striated muscle wasting and degeneration. Although the genetic basis for many of these disorders has been identified, the exact mechanism for disease pathogenesis remains unclear. The presence of oxidative stress (OS) is known to contribute to the pathophysiology and severity of the MD. Mitochondrial dysfunction is observed in MD and likely represents an important determinant of increased OS. Experimental antioxidant therapies have been implemented with the aim of protecting against disease progression, but results from clinical trials have been disappointing. In this study, we explored the capacity of the cacao flavonoid (−)-epicatechin (Epi) to mitigate OS by acting as a positive regulator of mitochondrial structure/function endpoints and redox balance control systems in skeletal and cardiac muscles of dystrophic, δ-sarcoglycan (δ-SG) null mice. Wild type or δ-SG null 2.5 month old male mice were treated via oral gavage with either water (control animals) or Epi (1 mg/kg, twice/day) for 2 weeks. Results evidence a significant normalization of total protein carbonylation, recovery of reduced/oxidized glutathione (GSH/GSSG ratio) and enhanced superoxide dismutase 2, catalase and citrate synthase activities with Epi treatment. These effects were accompanied by increases in protein levels for thiolredoxin, glutathione peroxidase, superoxide dismutase 2, catalase and mitochondrial endpoints. Furthermore, we evidence decreases in heart and skeletal muscle fibrosis, accompanied with an improvement in skeletal muscle function with treatment. These results warrant the further investigation of Epi as a potential therapeutic agent to mitigate MD associated muscle degeneration. PMID:25284161

  17. Eudistomin D and penaresin derivatives as modulators of ryanodine receptor channels and sarcoplasmic reticulum Ca2+ ATPase in striated muscle.

    PubMed

    Diaz-Sylvester, Paula L; Porta, Maura; Juettner, Vanessa V; Lv, Yuanzhao; Fleischer, Sidney; Copello, Julio A

    2014-04-01

    Eudistomin D (EuD) and penaresin (Pen) derivatives are bioactive alkaloids from marine sponges found to induce Ca(2+) release from striated muscle sarcoplasmic reticulum (SR). Although these alkaloids are believed to affect ryanodine receptor (RyR) gating in a "caffeine-like" manner, no single-channel study confirmed this assumption. Here, EuD and MBED (9-methyl-7-bromoeudistomin D) were contrasted against caffeine on their ability to modulate the SR Ca(2+) loading/leak from cardiac and skeletal muscle SR microsomes as well as the function of RyRs in planar bilayers. The effects of these alkaloids on [(3)H]ryanodine binding and SR Ca(2+) ATPase (SERCA) activity were also tested. MBED (1-5 μM) fully mimicked maximal activating effects of caffeine (20 mM) on SR Ca(2+) leak. At the single-channel level, MBED mimicked the agonistic action of caffeine on cardiac RyR gating (i.e., stabilized long openings characteristic of "high-open-probability" mode). EuD was a partial agonist at the maximal doses tested. The tested Pen derivatives displayed mild to no agonism on RyRs, SR Ca(2+) leak, or [(3)H]ryanodine binding studies. Unlike caffeine, EuD and some Pen derivatives significantly inhibited SERCA at concentrations required to modulate RyRs. Instead, MBED's affinity for RyRs (EC50 ∼ 0.5 μM) was much larger than for SERCA (IC50 > 285 μM). In conclusion, MBED is a potent RyR agonist and, potentially, a better choice than caffeine for microsomal and cell studies due to its reported lack of effects on adenosine receptors and phosphodiesterases. As a high-affinity caffeine-like probe, MBED could also help identify the caffeine-binding site in RyRs. PMID:24423447

  18. (-)-Epicatechin improves mitochondrial-related protein levels and ameliorates oxidative stress in dystrophic δ-sarcoglycan null mouse striated muscle.

    PubMed

    Ramirez-Sanchez, Israel; De los Santos, Sergio; Gonzalez-Basurto, Silvia; Canto, Patricia; Mendoza-Lorenzo, Patricia; Palma-Flores, Carlos; Ceballos-Reyes, Guillermo; Villarreal, Francisco; Zentella-Dehesa, Alejandro; Coral-Vazquez, Ramon

    2014-12-01

    Muscular dystrophies (MDs) are a group of heterogeneous genetic disorders characterized by progressive striated muscle wasting and degeneration. Although the genetic basis for many of these disorders has been identified, the exact mechanism of disease pathogenesis remains unclear. The presence of oxidative stress (OS) is known to contribute to the pathophysiology and severity of the MD. Mitochondrial dysfunction is observed in MD, and probably represents an important determinant of increased OS. Experimental antioxidant therapies have been implemented with the aim of protecting against disease progression, but results from clinical trials have been disappointing. In this study, we explored the capacity of the cacao flavonoid (-)-epicatechin (Epi) to mitigate OS by acting as a positive regulator of mitochondrial structure/function endpoints and redox balance control systems in skeletal and cardiac muscles of dystrophic, δ-sarcoglycan (δ-SG) null mice. Wild-type or δ-SG null 2.5-month-old male mice were treated via oral gavage with either water (controls) or Epi (1 mg·kg(-1) , twice daily) for 2 weeks. The results showed significant normalization of total protein carbonylation, recovery of the glutathione/oxidized glutathione ratio and enhanced superoxide dismutase 2, catalase and citrate synthase activities with Epi treatment. These effects were accompanied by increases in the protein levels of thioredoxin, glutathione peroxidase, superoxide dismutase 2, catalase, and mitochondrial endpoints. Furthermore, we found decreases in heart and skeletal muscle fibrosis, accompanied by an improvement in skeletal muscle function, with treatment. These results warrant further investigation of Epi as a potential therapeutic agent to mitigate MD-associated muscle degeneration. PMID:25284161

  19. Stimulus rate dependence of regional cerebral blood flow in human striate cortex, demonstrated by positron emission tomography

    SciTech Connect

    Fox, P.T.; Raichle, M.E.

    1984-05-01

    The purpose of this investigation was to determine the relationship between the repetition rate of a simple sensory stimulus and regional cerebral blood flow (rCBF) in the human brain. Positron emission tomography (PET), using intravenously administered H/sub 2/(/sup 15/)O as the diffusible blood-flow tracer, was employed for all CBF measurements. The use of H/sub 2/(/sup 15/)O with PET allowed eight CBF measurements to be made in rapid sequence under multiple stimulation conditions without removing the subject from the tomograph. Nine normal volunteers each underwent a series of eight H2(/sup 15/)O PET measurements of CBF. Initial and final scans were made during visual deprivation. The six intervening scans were made during visual activation with patterned-flash stimuli given in random order at 1.0-, 3.9-, 7.8-, 15.5-, 33.1-, and 61-Hz repetition rates. The region of greatest rCBF increase was determined. Within this region the rCBF was determined for every test condition and then expressed as the percentage change from the value of the initial unstimulated scan (rCBF% delta). In every subject, striate cortex rCBF% delta varied systematically with stimulus rate. Between 0 and 7.8 Hz, rCBF% delta was a linear function of stimulus repetition rate. The rCBF response peaked at 7.8 Hz and then declined. The rCBF% delta during visual stimulation was significantly greater than that during visual deprivation for every stimulus rate except 1.0 Hz. The anatomical localization of the region of peak rCBF response was determined for every subject to be the mesial occipital lobes along the calcarine fissure, primary visual cortex. Stimulus rate is a significant determinant of rCBF response in the visual cortex. Investigators of brain responses to selective activation procedures should be aware of the potential effects of stimulus rate on rCBF and other measurements of cerebral metabolism.

  20. Changes in Late Cretaceous-Quaternary Caribbean plate motion directions inferred from paleostress measurements from striated fault planes

    NASA Astrophysics Data System (ADS)

    Batbayar, K.; Mann, P.; Hippolyte, J.

    2013-12-01

    We compiled paleostress analyses from previous research works collected at 591 localities of striated fault planes in rocks ranging in age from Late Cretaceous to Quaternary in the circum-Caribbean and Mexico. The purpose of the study is to quantify a progressive clockwise rotation of the Caribbean plate during its Late Cretaceous to recent subduction of the Proto-Caribbean seaway. Paleostress analysis is based on the assumption that slickenside lineations indicate both the direction and sense of maximum resolved shear stress on that fault plane. We have plotted directions of maximum horizontal stress onto plate tectonic reconstructions of the circum-Caribbean plate boundaries and infer that these directions are proxies for paleo-plate motion directions of the Caribbean plate. Plotting these stress directions onto reconstructions provided a better visualization of the relation of stress directions to blocks at their time of Late Cretaceous to recent deformation. Older, more deformed rocks of Late Cretaceous to Eocene ages yield a greater scatter in derived paleostress directions as these rocks have steeper dips, more pervasive faulting, and were likely affected by large rotations as known from previous paleomagnetic studies of Caribbean plate margins. Despite more scatter in measurements from older rock units, four major events that affected the Caribbean plate and the Great Arc of the Caribbean (GAC) are recognizable from changing orientations of stress directions: 1) Late Cretaceous collision of the GAC with southern Mexico and Colombia is consistent with NE directions of maximum compression in rocks of this age range in southern Mexico and EW directions in Colombia as the GAC approached the Proto-Caribbean seaway; 2) Paleocene-Eocene collision of the GAC with the Bahamas platform in Cuba and Hispaniola and with the South American plate in Venezuela is consistent with CW rotations of stress directions in rocks of these ages in the northern Caribbean and CCW

  1. [Receptive fields of cat striate neurons: dynamics of weight and topographical characteristics of the excitatory zone of the neuron receptive fields in the visual cortex].

    PubMed

    Lazareva, N A; Kozhukhov, S A; Sharaev, G A; Novikova, R V; Tikhomirov, A S; Tsutskiridze, D Iu; Shevelev, I A

    2010-01-01

    In 22 acute experiments on anesthetized and immobilized adult cats, the dynamics of 83 on- and/or off-receptive fields (RF) was studied in 47 striate neurons with the method of temporal slices by mapping with single-flash stimuli. The latency of the RF appearance was 88 +/- 5 ms, and its duration was 192 +/- 12 ms. Dynamical wavy changes in the RF sizes and weights repeating up to three times were revealed. The mean duration of one wave was 95 +/- 4 ms. In 99% of cases, the RF discharge center defined for one temporal slice also displaced in an undulatory way relatively the RF's center defined for whole analysis period. The mean duration of this undulatory cycle was 67.3 +/- 3 ms. In 72.5% of cases, the displacement of the discharge center followed different trajectories inscribed in an ellipse. The functional significance of such changes in the RFs of striate neurons is discussed with regard to the dynamics of their detector features and underlying mechanisms.

  2. Detection of the nicotinic acetylcholine receptor alpha-subunit mRNA by in situ hybridization at neuromuscular junctions of 15-day-old chick striated muscles.

    PubMed Central

    Fontaine, B; Sassoon, D; Buckingham, M; Changeux, J P

    1988-01-01

    In adult vertebrate striated muscle, the nicotinic acetylcholine receptor (AChR) is almost exclusively localized in the postsynaptic membrane of the neuromuscular junction. Using in situ hybridization, we show that, in two different chicken muscles [the slow multi-innervated anterior latissimus dorsi (ALD) and the fast singly innervated posterior latissimus dorsi (PLD)], the AChR alpha-subunit mRNA is detected at discrete regions on myofibres and that these regions co-localize (80% correspondence) with neuromuscular junctions identified by histochemical staining for acetylcholinesterase. Moreover, autoradiographic grains densely accumulate on and around subsynaptic nuclei. In contrast, hybridization with an actin probe results in a strong signal distributed over the entire length of the myofibres. Denervation increases the level of AChR alpha-subunit mRNA both in the PLD and to a lesser extent in the ALD. By in situ hybridization we observe that, although a perinuclear pattern is maintained, the labelled nuclei appear randomly distributed among approximately 10% of the nuclei. These results are discussed in a model of AChR gene expression in vertebrate striated muscle fibres. Images PMID:3396533

  3. The ultrastructure and contractile properties of a fast-acting, obliquely striated, myosin-regulated muscle: the funnel retractor of squids

    PubMed Central

    Rosenbluth, Jack; Szent-Györgyi, Andrew G.; Thompson, Joseph T.

    2010-01-01

    We investigated the ultrastructure, contractile properties, and in vivo length changes of the fast-acting funnel retractor muscle of the long-finned squid Doryteuthis pealeii. This muscle is composed of obliquely striated, spindle-shaped fibers ~3 μm across that have an abundant sarcoplasmic reticulum, consisting primarily of membranous sacs that form ‘dyads’ along the surface of each cell. The contractile apparatus consists of ‘myofibrils’ ~0.25–0.5 μm wide in cross section arrayed around the periphery of each cell, surrounding a central core that contains the nucleus and large mitochondria. Thick myofilaments are ~25 nm in diameter and ~2.8 μm long. ‘Dense bodies’ are narrow, resembling Z lines, but are discontinuous and are not associated with the cytoskeletal fibrillar elements that are so prominent in slower obliquely striated muscles. The cells approximate each other closely with minimal intervening intercellular connective tissue. Our physiological experiments, conducted at 17°C, showed that the longitudinal muscle fibers of the funnel retractor were activated rapidly (8 ms latent period following stimulation) and generated force rapidly (peak twitch force occurred within 50 ms). The longitudinal fibers had low Vmax (2.15 ±0.26 L0 s−1, where L0 was the length that generated peak isometric force) but generated relatively high isometric stress (270±20 mN mm−2 physiological cross section). The fibers exhibited a moderate maximum power output (49.9 W kg−1), compared with vertebrate and arthropod cross striated fibers, at a V/Vmax of 0.33±0.044. During ventilation of the mantle cavity and locomotion, the funnel retractor muscle operated in vivo over a limited range of strains (+0.075 to −0.15 relative to resting length, LR) and at low strain rates (from 0.16 to 0.91 LR s−1 ), corresponding to a range of V/Vmax from 0.073 to 0.42. During the exhalant phase of the jet the range of strains was even narrower: maximum range less than ±0

  4. Reticulated, Hyperchromic Rash in a Striated Pattern Mimicking Atopic Dermatitis and Fungal Infection in a 2-Month-Old Female: A Case of Incontinentia Pigmenti

    PubMed Central

    Poliak, Nina; Le, Alexandre; Rainey, Anthony

    2016-01-01

    We present a 12-month-old Hispanic female with a reticulated, hyperchromic rash in a striated pattern appearing on upper and lower extremities and trunk and back since the age of 6 weeks. Over the next 10 months, the rash persisted. The rash did not respond to treatment with antifungals and steroids. During her 6-month wellness visit, the patient was diagnosed with incontinentia pigmenti (IP), a rare X-linked dominant disorder, fatal to male fetuses in utero. IP can lead to serious neurological and ophthalmologic consequences. Early diagnosis by primary care physicians and parental education about the condition are essential for prevention of retinal detachment, developmental delay, and dental abnormalities. PMID:27195166

  5. Segregation of short-wavelength sensitive ("blue") cone signals among neurons in the lateral geniculate nucleus and striate cortex of marmosets.

    PubMed

    Hashemi-Nezhad, Maziar; Blessing, Esther M; Dreher, Bogdan; Martin, Paul R

    2008-11-01

    We measured functional input from short-wavelength selective (S) cones to neurons in the dorsal lateral geniculate nucleus (LGN) and striate cortex (area V1) in anaesthetized marmosets. We found that most magnocellular (MC) and parvocellular (PC) cells receive very little (<5%) functional input from S cones, whereas blue-on cells of the koniocellular (KC) pathway receive dominant input from S cones. Cells dominated by S cone input were not encountered in V1, but V1 cells received more S cone input than PC or MC cells. This suggests that S cone inputs are distributed broadly among neurons in V1. No differences in strength of S cone inputs were seen on comparing dichromatic and trichromatic marmosets, suggesting that the addition of a medium-long wavelength selective cone-opponent ("red-green") channel to a dichromatic visual system does not detectably affect the chromatic properties of the S cone pathways. PMID:18397798

  6. Acute ethanol inhibits calcium influxes into esophageal smooth but not striated muscle: a possible mechanism for ethanol-induced inhibition of esophageal contractility.

    PubMed

    Keshavarzian, A; Zorub, O; Sayeed, M; Urban, G; Sweeney, C; Winship, D; Fields, J

    1994-09-01

    In both humans and cats, EtOH administered in vivo and acutely decreases contractility of smooth muscle of lower esophageal sphincter (LES) and lower esophagus (LE), but not striated muscle of upper esophagus. To see if these effects are associated with perturbation of Ca++ homeostasis, esophageal muscle slices were incubated in vitro with EtOH and then 45Ca++. At steady-state Ca++ uptake, some slices were exposed to 1 microM carbachol (CCH). Although 100 mM EtOH had no effect on Ca++ uptake into resting or stimulated striated muscle of upper esophagus, it significantly inhibited Ca++ uptake into smooth muscle of LES and LE. For unstimulated LE and resting LES, 100 mM EtOH significantly inhibited both initial uptake and steady-state levels, whereas lower doses had no significant effect. EtOH at 100 mM also affected changes in Ca++ content induced by CCH stimulation. CCH increased total exchangeable tissue Ca++ content in LE, whereas it decreased Ca++ content in LES. EtOH at 100 mM blunted these CCH-induced effects in both LES and LE. In contrast to resting muscle, inhibition of CCH-stimulated LE muscle was not limited to 100 mM EtOH, because substantial and significant inhibition was also seen at EtOH doses of 25 and 50 mM, doses which are relevant even in social drinking. Thus, EtOH inhibition of Ca++ influx into esophageal muscle is selective for smooth muscle, can occur at pharmacologically relevant EtOH doses and could be the underlying mechanism for EtOH's inhibition of contractility of esophageal smooth muscle. PMID:7932153

  7. Short-term microvascular response of striated muscle to cp-Ti, Ti-6Al-4V, and Ti-6Al-7Nb.

    PubMed

    Pennekamp, Peter H; Gessmann, Jan; Diedrich, Oliver; Burian, Björn; Wimmer, Markus A; Frauchiger, Vinzenz M; Kraft, Clayton N

    2006-03-01

    Due to excellent mechanical properties and good corrosion resistance, titanium-aluminium-vanadium (Ti-6Al-4V) and titanium-aluminium-niobium (Ti-6Al-7Nb) are extensively used for orthopedic surgery. Concern has been voiced concerning the implications of the constituent vanadium in Ti-6Al-4V on the surrounding environment. Particularly in osteosynthesis where the alloys stand in direct contact to skeletal muscle, undesirable biologic reactions may have severe consequences. In a comparative study, we assessed in vivo nutritive perfusion and leukocytic response of striated muscle to the metals Ti-6Al-4V, Ti-6Al-7Nb, and commercially pure titanium (cpTi), thereby drawing conclusions on their short-term inflammatory potential. In 28 hamsters, utilizing the dorsal skinfold chamber preparation and intravital microscopy, we quantified primary and secondary leukocyte-endothelial cell interaction, leukocyte extravasation, microvascular diameter change, and capillary perfusion in collecting and postcapillary venules of skeletal muscle. A manifest discrepancy between the metals concerning impact on local microvascular parameters was not found. All metals induced an only transient and moderate inflammatory response. Only a slight increase in leukocyte recruitment and a more sluggish recuperation of inflammatory parameters in animals treated with Ti-6Al-4V compared to the other two metals suggested a minor, overall not significant discrepancy in biocompatibility. Gross toxicity of bulk Ti-6Al-4V on surrounding tissue could not be found. Conclusively, the commonly used biomaterials Ti-6Al-4V, Ti-6Al-7Nb, and cpTi induce an only transient inflammatory answer of the skeletal muscle microvascular system. Our results indicate that on the microvascular level the tested bulk Ti-alloys and cpTi do not cause adverse biologic reactions in striated muscle.

  8. A role of the LIN-12/Notch signaling pathway in diversifying the non-striated egg-laying muscles in C. elegans.

    PubMed

    Hale, Jared J; Amin, Nirav M; George, Carolyn; Via, Zachary; Shi, Herong; Liu, Jun

    2014-05-15

    The proper formation and function of an organ is dependent on the specification and integration of multiple cell types and tissues. An example of this is the Caenorhabditis elegans hermaphrodite egg-laying system, which requires coordination between the vulva, uterus, neurons, and musculature. While the genetic constituents of the first three components have been well studied, little is known about the molecular mechanisms underlying the specification of the egg-laying musculature. The egg-laying muscles are non-striated in nature and consist of sixteen cells, four each of type I and type II vulval muscles and uterine muscles. These 16 non-striated muscles exhibit distinct morphology, location, synaptic connectivity and function. Using an RNAi screen targeting the putative transcription factors in the C. elegans genome, we identified a number of novel factors important for the diversification of these different types of egg-laying muscles. In particular, we found that RNAi knockdown of lag-1, which encodes the sole C. elegans ortholog of the transcription factor CSL (CBF1, Suppressor of Hairless, LAG-1), an effector of the LIN-12/Notch pathway, led to the production of extra type I vulval muscles. Similar phenotypes were also observed in animals with down-regulation of the Notch receptor LIN-12 and its DSL (Delta, Serrate, LAG-2) ligand LAG-2. The extra type I vulval muscles in animals with reduced LIN-12/Notch signaling resulted from a cell fate transformation of type II vulval muscles to type I vulval muscles. We showed that LIN-12/Notch was activated in the undifferentiated type II vulval muscle cells by LAG-2/DSL that is likely produced by the anchor cell (AC). Our findings provide additional evidence highlighting the roles of LIN-12/Notch signaling in coordinating the formation of various components of the functional C. elegans egg-laying system. We also identify multiple new factors that play critical roles in the proper specification of the different types

  9. Monocular and binocular response properties of cells in the striate-recipient zone of the cat's lateral posterior-pulvinar complex.

    PubMed

    Casanova, C; Freeman, R D; Nordmann, J P

    1989-08-01

    1. We have studied response properties of single cells in the striate-recipient zone of the cat's lateral posterior-pulvinar (LP-P) complex. This zone is in the lateral section of the lateral posterior nucleus (LP1). Our purpose was to determine basic response characteristics of these cells and to investigate the possibility that the LP-P complex is a center of integration that is dominated by input from visual cortex. 2. The majority (72%) of cells in the striate-recipient zone respond to drifting sinusoidal gratings with unmodulated discharge. 3. Cells in the LP1 are selective to the orientation of gratings, and tuning functions have a mean bandwidth of 31 degrees. More than one-half of these units are direction-selective. The preferred orientation and the tuning widths for the two eyes are generally well matched. However, a few cells exhibited the interesting property of opposite preferred directions for the two eyes. Orientation tuning for a small group of cells was different for the mean discharge and first harmonic components, suggesting a convergence from different inputs to these cells. 4. Two-thirds of LP1 cells are tuned to low spatial frequencies (less than 0.5 c/deg). The tuning is broad with a mean bandwidth of 2.2 octaves. The remaining one-third of the units are low-pass because they show no attenuation of their responses to low spatial frequencies. Both eyes exhibit the same spatial frequency preference and the same spatial frequency tuning. There is a high correlation between spatial frequency and orientation selectivities. 5. All cells tested are tuned for temporal frequency with a sharp attenuation for low frequencies. The optimal values range between 4 and 8 Hz, and the mean bandwidth is 2.2 octaves. 6. Cells in LP1 are mostly binocular. When monocular, cells are almost always contralaterally driven. Dichoptic presentation of gratings reveals the presence of strong binocular interaction. In almost all cases, these interactions are phase specific

  10. Isoform composition and gene expression of thick and thin filament proteins in striated muscles of mice after 30-day space flight.

    PubMed

    Ulanova, Anna; Gritsyna, Yulia; Vikhlyantsev, Ivan; Salmov, Nikolay; Bobylev, Alexander; Abdusalamova, Zarema; Rogachevsky, Vadim; Shenkman, Boris; Podlubnaya, Zoya

    2015-01-01

    Changes in isoform composition, gene expression of titin and nebulin, and isoform composition of myosin heavy chains as well as changes in titin phosphorylation level in skeletal (m. gastrocnemius, m. tibialis anterior, and m. psoas) and cardiac muscles of mice were studied after a 30-day-long space flight onboard the Russian spacecraft "BION-M" number 1. A muscle fibre-type shift from slow-to-fast and a decrease in the content of titin and nebulin in the skeletal muscles of animals from "Flight" group was found. Using Pro-Q Diamond staining, an ~3-fold increase in the phosphorylation level of titin in m. gastrocnemius of mice from the "Flight" group was detected. The content of titin and its phosphorylation level in the cardiac muscle of mice from "Flight" and "Control" groups did not differ; nevertheless an increase (2.2 times) in titin gene expression in the myocardium of flight animals was found. The observed changes are discussed in the context of their role in the contractile activity of striated muscles of mice under conditions of weightlessness.

  11. Merosin, a protein specific for basement membranes of Schwann cells, striated muscle, and trophoblast, is expressed late in nerve and muscle development.

    PubMed Central

    Leivo, I; Engvall, E

    1988-01-01

    We have identified a tissue-specific basement membrane-associated protein by using monoclonal antibodies prepared against a protein fraction of human placenta. In immunofluorescence, the monoclonal antibodies stained basement membranes of Schwann cells, striated muscle, and trophoblast, whereas no reaction was seen with any other basement membrane or tissue structure. In antibody-affinity chromatography of proteolytic digests of human placenta, a 65-kDa polypeptide was bound by these monoclonal antibodies. Rabbit antisera and monoclonal antibodies raised against the isolated 65-kDa polypeptide stained human and monkey tissues identically to the original monoclonal antibodies and reacted with an 80-kDa polypeptide in tissue extracts prepared without proteolysis. The 65-kDa and 80-kDa polypeptides were shown to be immunologically distinct from laminin, type IV collagen, fibronectin, and major serum proteins. They presumably represent a novel basement membrane-associated protein, which we have named merosin. No merosin immunoreactivity could be detected in cultures of any of 28 established cell lines. In developing mouse tissues, merosin staining first appeared at the newborn stage. The restricted tissue distribution and late developmental appearance of merosin suggest that the protein has a tissue-specific function associated with a high level of differentiation. Images PMID:3278318

  12. Manipulation of mtDNA heteroplasmy in all striated muscles of newborn mice by AAV9-mediated delivery of a mitochondria-targeted restriction endonuclease.

    PubMed

    Bacman, S R; Williams, S L; Duan, D; Moraes, C T

    2012-11-01

    Mitochondrial diseases are frequently caused by heteroplasmic mitochondrial DNA (mtDNA) mutations. As these mutations express themselves only at high relative ratios, any approach able to manipulate mtDNA heteroplasmy can potentially be curative. In this study, we developed a system to manipulate mtDNA heteroplasmy in all skeletal muscles from neonate mice. We selected muscle because it is one of the most clinically affected tissues in mitochondrial disorders. A mitochondria-targeted restriction endonuclease (mito-ApaLI) expressed from AAV9 particles was delivered either by intraperitoneal or intravenous injection in neonate mice harboring two mtDNA haplotypes, only one of which was susceptible to ApaLI digestion. A single injection was able to elicit a predictable and marked change in mtDNA heteroplasmy in all striated muscles analyzed, including heart. No health problems or reduction in mtDNA levels were observed in treated mice, suggesting that this approach could have clinical applications for mitochondrial myopathies.

  13. Isoform Composition and Gene Expression of Thick and Thin Filament Proteins in Striated Muscles of Mice after 30-Day Space Flight

    PubMed Central

    Ulanova, Anna; Gritsyna, Yulia; Vikhlyantsev, Ivan; Salmov, Nikolay; Bobylev, Alexander; Abdusalamova, Zarema; Rogachevsky, Vadim; Shenkman, Boris; Podlubnaya, Zoya

    2015-01-01

    Changes in isoform composition, gene expression of titin and nebulin, and isoform composition of myosin heavy chains as well as changes in titin phosphorylation level in skeletal (m. gastrocnemius, m. tibialis anterior, and m. psoas) and cardiac muscles of mice were studied after a 30-day-long space flight onboard the Russian spacecraft “BION-M” number 1. A muscle fibre-type shift from slow-to-fast and a decrease in the content of titin and nebulin in the skeletal muscles of animals from “Flight” group was found. Using Pro-Q Diamond staining, an ~3-fold increase in the phosphorylation level of titin in m. gastrocnemius of mice from the “Flight” group was detected. The content of titin and its phosphorylation level in the cardiac muscle of mice from “Flight” and “Control” groups did not differ; nevertheless an increase (2.2 times) in titin gene expression in the myocardium of flight animals was found. The observed changes are discussed in the context of their role in the contractile activity of striated muscles of mice under conditions of weightlessness. PMID:25664316

  14. Identification of striated muscle activator of Rho signaling (STARS) as a novel calmodulin target by a newly developed genome-wide screen.

    PubMed

    Furuya, Yusui; Denda, Miwako; Sakane, Kyohei; Ogusu, Tomoko; Takahashi, Sumio; Magari, Masaki; Kanayama, Naoki; Morishita, Ryo; Tokumitsu, Hiroshi

    2016-07-01

    To search for novel target(s) of the Ca(2+)-signaling transducer, calmodulin (CaM), we performed a newly developed genome-wide CaM interaction screening of 19,676 GST-fused proteins expressed in human. We identified striated muscle activator of Rho signaling (STARS) as a novel CaM target and characterized its CaM binding ability and found that the Ca(2+)/CaM complex interacted stoichiometrically with the N-terminal region (Ala13-Gln35) of STARS in vitro as well as in living cells. Mutagenesis studies identified Ile20 and Trp33 as the essential hydrophobic residues in CaM anchoring. Furthermore, the CaM binding deficient mutant (Ile20Ala, Trp33Ala) of STARS further enhanced its stimulatory effect on SRF-dependent transcriptional activation. These results suggest a connection between Ca(2+)-signaling via excitation-contraction coupling and the regulation of STARS-mediated gene expression in muscles.

  15. Isoform composition and gene expression of thick and thin filament proteins in striated muscles of mice after 30-day space flight.

    PubMed

    Ulanova, Anna; Gritsyna, Yulia; Vikhlyantsev, Ivan; Salmov, Nikolay; Bobylev, Alexander; Abdusalamova, Zarema; Rogachevsky, Vadim; Shenkman, Boris; Podlubnaya, Zoya

    2015-01-01

    Changes in isoform composition, gene expression of titin and nebulin, and isoform composition of myosin heavy chains as well as changes in titin phosphorylation level in skeletal (m. gastrocnemius, m. tibialis anterior, and m. psoas) and cardiac muscles of mice were studied after a 30-day-long space flight onboard the Russian spacecraft "BION-M" number 1. A muscle fibre-type shift from slow-to-fast and a decrease in the content of titin and nebulin in the skeletal muscles of animals from "Flight" group was found. Using Pro-Q Diamond staining, an ~3-fold increase in the phosphorylation level of titin in m. gastrocnemius of mice from the "Flight" group was detected. The content of titin and its phosphorylation level in the cardiac muscle of mice from "Flight" and "Control" groups did not differ; nevertheless an increase (2.2 times) in titin gene expression in the myocardium of flight animals was found. The observed changes are discussed in the context of their role in the contractile activity of striated muscles of mice under conditions of weightlessness. PMID:25664316

  16. Seasonal changes in isoform composition of giant proteins of thick and thin filaments and titin (connectin) phosphorylation level in striated muscles of bears (Ursidae, Mammalia).

    PubMed

    Salmov, N N; Vikhlyantsev, I M; Ulanova, A D; Gritsyna, Yu V; Bobylev, A G; Saveljev, A P; Makariushchenko, V V; Maksudov, G Yu; Podlubnaya, Z A

    2015-03-01

    Seasonal changes in the isoform composition of thick and thin filament proteins (titin, myosin heavy chains (MyHCs), nebulin), as well as in the phosphorylation level of titin in striated muscles of brown bear (Ursus arctos) and hibernating Himalayan black bear (Ursus thibetanus ussuricus) were studied. We found that the changes that lead to skeletal muscle atrophy in bears during hibernation are not accompanied by a decrease in the content of nebulin and intact titin-1 (T1) isoforms. However, a decrease (2.1-3.4-fold) in the content of T2 fragments of titin was observed in bear skeletal muscles (m. gastrocnemius, m. longissimus dorsi, m. biceps) during hibernation. The content of the stiffer N2B titin isoform was observed to increase relative to the content of its more compliant N2BA isoform in the left ventricles of hibernating bears. At the same time, in spite of the absence of decrease in the total content of T1 in the myocardium of hibernating brown bear, the content of T2 fragments decreased ~1.6-fold. The level of titin phosphorylation only slightly increased in the cardiac muscle of hibernating brown bear. In the skeletal muscles of brown bear, the level of titin phosphorylation did not vary between seasons. However, changes in the composition of MyHCs aimed at increasing the content of slow (I) and decreasing the content of fast (IIa) isoforms of this protein during hibernation of brown bear were detected. Content of MyHCs I and IIa in the skeletal muscles of hibernating Himalayan black bear corresponded to that in the skeletal muscles of hibernating brown bear.

  17. Spectral sideband produced by a hemispherical concave multilayer on the African shield-bug Calidea panaethiopica (Scutelleridae)

    NASA Astrophysics Data System (ADS)

    Vigneron, Jean Pol; Ouedraogo, Moussa; Colomer, Jean-François; Rassart, Marie

    2009-02-01

    The African shield-backed bug Calidea panaethiopica is a very colorful insect which produces a range of iridescent yellow, green, and blue reflections. The cuticle of the dorsal side of the insect, on the shield, the prothorax and part of the head, is pricked of uniformly distributed hemispherical hollow cavities a few tens micrometers deep. Under normal illumination and viewing the insect’s muffin-tin shaped surface gives rise to two distinct colors: a yellow spot arising from the bottom of the well and a blue annular cloud that appears to float around the yellow spot. This effect is explained by multiple reflections on a hemispherical Bragg mirror with a mesoscopic curvature. A multiscale computing methodology was found to be needed to evaluate the reflection spectrum for such a curved multilayer. This multiscale approach is very general and should be useful for dealing with visual effects in many natural and artificial systems.

  18. Microvascular response of striated muscle to common arthroplasty-alloys: A comparative in vivo study with CoCrMo, Ti-6Al-4V, and Ti-6Al-7Nb.

    PubMed

    Kraft, Clayton N; Burian, Björn; Diedrich, Oliver; Gessmann, Jan; Wimmer, Markus A; Pennekamp, Peter H

    2005-10-01

    The impairment of skeletal muscle microcirculation by a biomaterial may have profound consequences. Due to excellent physical and corrosion characteristics, CoCrMo-, Ti-6Al-4V-, and Ti-6Al-7Nb-alloys are commonly used in orthopedic surgery. Yet concern has been raised with regard to the implications of inevitable corrosion product of these metals on the surrounding biologic environment, particularly in the case of CoCrMo. We, therefore, studied in vivo nutritive perfusion and leukocytic response of striated muscle to these alloys, thereby drawing conclusions on their inflammatory potential. In 28 hamsters, utilizing the dorsal skinfold chamber preparation and intravital microscopy, we could demonstrate that the implant material CoCrMo has a marked impact on local microvascular parameters. While the Ti-alloys Ti-6Al-4V and Ti-6Al-7Nb induced only a transient and moderate inflammatory response, the implantation of a CoCrMo sample led to a distinct and persistent activation of leukocytes combined with disruption of the microvascular endothelial integrity and marked leukocyte extravasation. Animals with Ti-alloys showed a clear tendency of recuperation, while in all but one CoCrMo-treated animals, a breakdown of microcirculation prior to the scheduled end of the experiment was observed. Overall, the alloy Ti-6Al-7Nb was tolerated slightly better than Ti-6Al-4V under the chosen test conditions, though this discrepancy was not statistically significant. Conclusively, the commonly used biomaterials Ti-6Al-7Nb and Ti-6Al-4V induce a considerably lower inflammatory response in the skeletal muscle microvascular system, compared to a CoCrMo-alloy. With a minimum of adverse host reaction, our results indicate that for this particular model Ti-alloys are better tolerated than CoCrMo implant materials.

  19. Hyperactivation of L-type voltage-gated Ca2+ channels in Caenorhabditis elegans striated muscle can result from point mutations in the IS6 or the IIIS4 segment of the α1 subunit.

    PubMed

    Lainé, Viviane; Ségor, Jean Rony; Zhan, Hong; Bessereau, Jean-Louis; Jospin, Maelle

    2014-11-01

    Several human diseases, including hypokalemic periodic paralysis and Timothy syndrome, are caused by mutations in voltage-gated calcium channels. The effects of these mutations are not always well understood, partially because of difficulties in expressing these channels in heterologous systems. The use of Caenorhabditis elegans could be an alternative approach to determine the effects of mutations on voltage-gated calcium channel function because all the main types of voltage-gated calcium channels are found in C. elegans, a large panel of mutations already exists and efficient genetic tools are available to engineer customized mutations in any gene. In this study, we characterize the effects of two gain-of-function mutations in egl-19, which encodes the L-type calcium channel α1 subunit. One of these mutations, ad695, leads to the replacement of a hydrophobic residue in the IIIS4 segment. The other mutation, n2368, changes a conserved glycine of IS6 segment; this mutation has been identified in patients with Timothy syndrome. We show that both egl-19 (gain-of-function) mutants have defects in locomotion and morphology that are linked to higher muscle tone. Using in situ electrophysiological approaches in striated muscle cells, we provide evidence that this high muscle tone is due to a shift of the voltage dependency towards negative potentials, associated with a decrease of the inactivation rate of the L-type Ca(2+) current. Moreover, we show that the maximal conductance of the Ca(2+) current is decreased in the strongest mutant egl-19(n2368), and that this decrease is correlated with a mislocalization of the channel. PMID:25214488

  20. Striated muscle activator of Rho signalling (STARS) is a PGC-1α/oestrogen-related receptor-α target gene and is upregulated in human skeletal muscle after endurance exercise.

    PubMed

    Wallace, Marita A; Hock, M Benjamin; Hazen, Bethany C; Kralli, Anastasia; Snow, Rod J; Russell, Aaron P

    2011-04-15

    The striated muscle activator of Rho signalling (STARS) is an actin-binding protein specifically expressed in cardiac, skeletal and smooth muscle. STARS has been suggested to provide an important link between the transduction of external stress signals to intracellular signalling pathways controlling genes involved in the maintenance of muscle function. The aims of this study were firstly, to establish if STARS, as well as members of its downstream signalling pathway, are upregulated following acute endurance cycling exercise; and secondly, to determine if STARS is a transcriptional target of peroxisome proliferator-activated receptor gamma co-activator 1-α (PGC-1α) and oestrogen-related receptor-α (ERRα). When measured 3 h post-exercise, STARS mRNA and protein levels as well as MRTF-A and serum response factor (SRF) nuclear protein content, were significantly increased by 140, 40, 40 and 40%, respectively. Known SRF target genes, carnitine palmitoyltransferase-1β (CPT-1β) and jun B proto-oncogene (JUNB), as well as the exercise-responsive genes PGC-1α mRNA and ERRα were increased by 2.3-, 1.8-, 4.5- and 2.7-fold, 3 h post-exercise. Infection of C2C12 myotubes with an adenovirus-expressing human PGC-1α resulted in a 3-fold increase in Stars mRNA, a response that was abolished following the suppression of endogenous ERRα. Over-expression of PGC-1α also increased Cpt-1β, Cox4 and Vegf mRNA by 6.2-, 2.0- and 2.0-fold, respectively. Suppression of endogenous STARS reduced basal Cpt-1β levels by 8.2-fold and inhibited the PGC-1α-induced increase in Cpt-1β mRNA. Our results show for the first time that the STARS signalling pathway is upregulated in response to acute endurance exercise. Additionally, we show in C2C12 myotubes that the STARS gene is a PGC-1α/ERRα transcriptional target. Furthermore, our results suggest a novel role of STARS in the co-ordination of PGC-1α-induced upregulation of the fat oxidative gene, CPT-1β.

  1. Ontogenesis of receptive fields in the rabbit striate cortex

    NASA Technical Reports Server (NTRS)

    Mathers, L. H.; Chow, K. L.; Spear, P. D.; Grobstein, P.

    1974-01-01

    The development of receptive fields in rabbit pups was investigated by measuring their responses to various light stimuli and to electric shock delivered to the optic nerve head. The pups ranged in age from three to twenty-five days, allowing correlation of findings with maturation. The data, classified according to relation with symmetric or asymmetric field types, strongly suggest that retina maturation is the key factor in the rate of development in central visual pathways, and that central synaptic connections are made before the onset of retinal activity.

  2. Frog striated muscle is permeable to hydroxide and buffer anions.

    PubMed

    Venosa, R A; Kotsias, B A; Horowicz, P

    1994-04-01

    Hydroxide, bicarbonate and buffer anion permeabilities in semitendinosus muscle fibers of Rana pipiens were measured. In all experiments, the fibers were initially equilibrated in isotonic, high K2SO4 solutions at pHo = 7.2 buffered with phosphate. Two different methods were used to estimate permeabilities: (i) membrane potential changes were recorded in response to changes in external ion concentrations, and (ii) intracellular pH changes were recorded in response to changes in external concentrations of ions that alter intracellular pH. Constant field equations were used to calculate relative or absolute permeabilities. In the first method, to increase the size of the membrane potential change produced by a sudden change in anion entry, external K+ was replaced by Cs+ prior to changes of the anion under study. At constant external Cs+ activity, a hyperpolarization results from increasing external pH from 7.2 to 10.0 or higher, using either CAPS (3-[cyclohexylamino]-1-propanesulfonic acid) or CHES (2-[N-cyclohexylamino]-ethanesulfonic acid) as buffer. For each buffer, the protonated form is a zwitterion of zero net charge and the nonprotonated form is an anion. Using reported values of H+ permeability, calculations show that the reduction in [H+]o cannot account for the hyperpolarizations produced by alkaline solutions. Membrane hyperpolarization increases with increasing total external buffer concentration at constant external pH, and with increasing external pH at constant external buffer anion concentration. Taken together, these observations indicate that both OH- and buffer anions permeate the surface membrane. The following relative permeabilities were obtained at pHo = 10.0 +/- 0.3: (POH/PK) = 890 +/- 150, (PCAPS/PK) = 12 +/- 2, (PCHES/PK) = 5.3 +/- 0.9, and (PNO3/PK) = 4.7 +/- 0.5. PNO3/PK was independent of pHo up to 10.75. At pHo = 9.6, (PHCO3/PK) = 0.49 +/- 0.03; at pHo = 8.9, (PCl/PK) = 18 +/- 2 and at pHo = 7.1, (PHEPES/PK) = 20 +/- 2. In the second method, on increasing external pH from 7.2 to 10.0, using 2.5 mM CAPS (total buffer concentration), the internal pH increases linearly with time over the next 10 min. This alkalinization is due to the entry of OH- and the absorption of internal H+ by entering CAPS- anion. The rate of CAPS- entry was determined in experiments in which the external CAPS concentration was increased at constant external pH. Such increases invariably produced an increase in the rate of internal alkalinization, which was reversed when the CAPS concentration was reduced to its initial value.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:8071988

  3. Age changes in cross striated muscle of the rat

    PubMed Central

    Gutmann, E.; Hanzlíková, V.; Vyskočil, F.

    1971-01-01

    1. Senile muscle atrophy is characterized by a marked reduction in the frequency of spontaneous transmitter release with no electrophysiological evidence of denervation. 2. In spite of the reduced number of muscle fibres, there is no ultrastructural evidence for denervation at the end-plates. There is agglutination of synaptic vesicles, neurotubules and filaments, thickening of the basement membrane, widening of the primary synaptic cleft, and irregular branching of the junctional infoldings, but no axonal degeneration. 3. The contractile process in senile muscles is slowed down as is indicated by a prolongation of contraction time, latency period, maximum rate of twitch tension and relaxation time. 4. The muscle fibres show proliferation of the T system and increased SR but no fragmentation as is observed in denervation atrophy. 5. Senile muscle atrophy thus presents some specific features affecting both pre- and post-synaptic structures, related to a very slow process of deterioration of the neuromuscular contact. ImagesFig. 4Fig. 5Fig. 6Fig. 7Fig. 8Fig. 9Fig. 10Fig. 1Fig. 2Fig. 3 PMID:4326996

  4. Mapping striate and extrastriate visual areas in human cerebral cortex.

    PubMed Central

    DeYoe, E A; Carman, G J; Bandettini, P; Glickman, S; Wieser, J; Cox, R; Miller, D; Neitz, J

    1996-01-01

    Functional magnetic resonance imaging (fMRI) was used to identify and map the representation of the visual field in seven areas of human cerebral cortex and to identify at least two additional visually responsive regions. The cortical locations of neurons responding to stimulation along the vertical or horizontal visual field meridia were charted on three-dimensional models of the cortex and on unfolded maps of the cortical surface. These maps were used to identify the borders among areas that would be topographically homologous to areas V1, V2, V3, VP, and parts of V3A and V4 of the macaque monkey. Visually responsive areas homologous to the middle temporal/medial superior temporal area complex and unidentified parietal visual areas were also observed. The topography of the visual areas identified thus far is consistent with the organization in macaque monkeys. However, these and other findings suggest that human and simian cortical organization may begin to differ in extrastriate cortex at, or beyond, V3A and V4. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 PMID:8637882

  5. Induction into Educational Research Networks: The Striated and the Smooth

    ERIC Educational Resources Information Center

    Hodgson, Naomi; Standish, Paul

    2006-01-01

    Educational research as an academic field can be understood as a network or group of networks and, therefore, to consist of interconnected nodes that structure the way the field operates and understands its purpose. This paper deals with the nature of the induction of postgraduate students into the network of educational research that takes place…

  6. Statistical methods for the forensic analysis of striated tool marks

    SciTech Connect

    Hoeksema, Amy Beth

    2013-01-01

    In forensics, fingerprints can be used to uniquely identify suspects in a crime. Similarly, a tool mark left at a crime scene can be used to identify the tool that was used. However, the current practice of identifying matching tool marks involves visual inspection of marks by forensic experts which can be a very subjective process. As a result, declared matches are often successfully challenged in court, so law enforcement agencies are particularly interested in encouraging research in more objective approaches. Our analysis is based on comparisons of profilometry data, essentially depth contours of a tool mark surface taken along a linear path. In current practice, for stronger support of a match or non-match, multiple marks are made in the lab under the same conditions by the suspect tool. We propose the use of a likelihood ratio test to analyze the difference between a sample of comparisons of lab tool marks to a field tool mark, against a sample of comparisons of two lab tool marks. Chumbley et al. (2010) point out that the angle of incidence between the tool and the marked surface can have a substantial impact on the tool mark and on the effectiveness of both manual and algorithmic matching procedures. To better address this problem, we describe how the analysis can be enhanced to model the effect of tool angle and allow for angle estimation for a tool mark left at a crime scene. With sufficient development, such methods may lead to more defensible forensic analyses.

  7. Responses of neurons in cat striate cortex to vernier offsets in reverse contrast stimuli.

    PubMed

    Swindale, N V

    1995-01-01

    This paper examines how the responses of cells in area 17 of the cat vary as a function of the vernier offset between a bright and a dark bar. The study was prompted by the finding that human vernier acuity is reduced for bars or edges of opposite contrast sign (Mather & Morgan, 1986; O'Shea & Mitchell, 1990). Both simple and complex cells showed V-shaped tuning curves for reverse contrast stimuli: i.e. response was minimum at alignment, and increased with increasing vernier offset. For vernier bars with the same contrast sing, v-shaped tuning curves were found, as reported earlier (Swindale & Cynader, 1986). Sensitivity to offset was inversely correlated in the two paradigms. However, complex cells with high sensitivity to offsets in a normal vernier stimulus were significantly less sensitive to offsets in reverse contrast stimuli. A cell's response to a vernier stimulus in which both bars are bright can be predicted by the shape of its orientation tuning curve, if the vernier stimulus is approximated by a single bar with an orientation equal to that of a line joining the midpoints of the two component bars (Swindale & Cynader, 1986). This approximation did not hold for the reverse contrast condition: orientation tuning curves for compound bars were broad and shallow, rather than bimodal, with peaks up to 40 deg from the preferred orientation. Results from simple cells were compared with predictions made by a linear model of the receptive field. The model predicted the [symbol: see text]-shaped tuning curves found for reverse contrast stimuli. It also predicted that absolute values of tuning slopes for vernier offsets in reverse contrast stimuli might sometimes be higher than with normal stimuli. This was observed in some simple cells. The model was unable to explain the shape of orientation tuning curves for compound bars, nor could it explain the breakdown of the equivalent orientation approximation. PMID:8924405

  8. Testosterone enhances C-14 2-deoxyglucose uptake by striated muscle. [sex hormones and muscle

    NASA Technical Reports Server (NTRS)

    Toop, J.; Max, S. R.

    1982-01-01

    The effect of testosterone propionate (TP) on C-14 2-deoxyglucose (C-14 2DG) uptake was studied in the rat levator ani muscle in vivo using the autoradiographic technique. Following a delay of 1 to 3 h after injecting TP, the rate of C-14 2DG uptake in experimental animals began to increase and continued to increase for at least 20 h. The label, which corresponds to C-14 2-deoxyglucose 6-phosphate, as demonstrated by chromatographic analysis of muscle extracts, was uniformly distributed over the entire muscle and was predominantly in muscle fibers, although nonmuscular elements were also labeled. The 1 to 3 h time lag suggests that the TP effect may be genomic, acting via androgen receptors, rather than directly on muscle membranes. Acceleration of glucose uptake may be an important early event in the anabolic response of the rat levator ani muscle to androgens.

  9. Modulation of the cytosolic androgen receptor in striated muscle by sex steroids

    NASA Technical Reports Server (NTRS)

    Rance, N. E.; Max, S. R.

    1984-01-01

    The effects of orchiectomy (GDX) and of subsequent administration of testosterone propionate (TP) or 17(beta)-estradiol (E2) on the maximum binding (Bmax) and apparent Kd of the cytosolic androgen receptor in levator ani (LA) and skeletal muscles of adult male Sprague-Dawley rats are investigated experimentally. The results are presented in graphs and discussed. In LA, BMAX is found to rise from a control level of 2.5 fmol/mg protein to 280, 600, 478, and 133 percent of control at 12 h, 14 d, 30 d, and 44 d after GDX, respectively, while Kd increased only insignificantly (from 680 to 960 fM); Bmax is held at control levels for 6 h by cycloheximide given at GDX, is unaffected by TP given at 30 d, and is further increased (by 480 percent at 44 d) by administration of E2 at 30 d. Bmax in skeletal muscles is found to increase to 139, 212, 220, and 158 percent of control at 12 h, 14 d, 30 d, and 44 d, respectively; Bmax is returned to control at 44 d by TP at 30 d but is not affected by E2. The effect of E2 in LA is attributed to either induction of the cytosolic receptor or a decreased rate of receptor degradation.

  10. Holonomy, quantum mechanics and the signal-tuned Gabor approach to the striate cortex

    NASA Astrophysics Data System (ADS)

    Torreão, José R. A.

    2016-02-01

    It has been suggested that an appeal to holographic and quantum properties will be ultimately required for the understanding of higher brain functions. On the other hand, successful quantum-like approaches to cognitive and behavioral processes bear witness to the usefulness of quantum prescriptions as applied to the analysis of complex non-quantum systems. Here, we show that the signal-tuned Gabor approach for modeling cortical neurons, although not based on quantum assumptions, also admits a quantum-like interpretation. Recently, the equation of motion for the signal-tuned complex cell response has been derived and proven equivalent to the Schrödinger equation for a dissipative quantum system whose solutions come under two guises: as plane-wave and Airy-packet responses. By interpreting the squared magnitude of the plane-wave solution as a probability density, in accordance with the quantum mechanics prescription, we arrive at a Poisson spiking probability — a common model of neuronal response — while spike propagation can be described by the Airy-packet solution. The signal-tuned approach is also proven consistent with holonomic brain theories, as it is based on Gabor functions which provide a holographic representation of the cell’s input, in the sense that any restricted subset of these functions still allows stimulus reconstruction.

  11. Striated dust tail of Comet West 1976 VI as a particle fragmentation phenomenon

    SciTech Connect

    Sekanina, Z.; Farrell, J.A.

    1980-11-01

    The motions of 16 striae in the dust tail of Comet West between 4 and 7 March 1976 have been successfully fitted on four small-scale photographs. Our model assumes that the striae are the result of the ejection of dust particles that subsequently fragment in the tail. The particles responsible for the formation of a discrete stria must be emitted simultaneously, be subjected to the same repulsive acceleration in the tail, and break up simultaneously. The results of the analysis indicate a strong correlation between the ejection times and the times of known explosive events. The repulsive accelerations of the fragments are found to be between 0.6 and 2.7 times the solar attraction, indicating submicron-sized absorbing particles. We also find that the repulsive accelerations of parent particles are only slightly smaller than those of their fragments, suggesting comparable area-to-mass ratios between parents and fragments, and therefore highly nonspherical shapes of parents. Complex, tenuously bonded, chain-like aggregates of submicron-sized grains would satisfy these conditions. The mass of dust in an average stria is estimated to be about 10/sup 9/ g. There was no measurable effect from the Lorentz force, indicating an upper limit of a few volts for the electric charge of the fragments. We consider rotational bursting caused by a ''windmill'' effect of radiation pressure to be a possible fragmentation mechanism. Application of a simple chain-particle model suggests the existence of discrete particle types.

  12. The striated dust tail of Comet West 1976 VI as a particle fragmentation phenomenon

    NASA Technical Reports Server (NTRS)

    Sekanina, Z.; Farrell, J. A.

    1980-01-01

    The motions of 16 striae in the dust tail of Comet West are studied. It is found that all 16 striae have originated from particle ejections, and that the particles responsible for the formation of a discrete striae must be emitted simultaneously, be subjected to the same repulsive acceleration in the tail, and break up simultaneously. A strong correlation is found between the ejection times and the times of known explosive events. The repulsive accelerations of particle fragments in the striae vary from 0.6 to 2.7 times the solar attraction, indicating submicron grains of strongly absorbing materials. The repulsive acceleration of parent particles range from 0.55 to 1.10, which is only slightly smaller than those of their fragments and suggests highly nonspherical shapes of parents. The mass of dust in an average striae is estimated to be one-billion grams. Rotational bursting is discussed as a possible fragmentation mechanism. The absence of measurable effects of the Lorentz force indicate an upper limit of a few volts for the electric charge of the fragments.

  13. Effects of different activity and inactivity paradigms on myosin heavy chain gene expression in striated muscle

    NASA Technical Reports Server (NTRS)

    Baldwin, K. M.; Haddad, F.

    2001-01-01

    The goal of this mini-review is to summarize findings concerning the role that different models of muscular activity and inactivity play in altering gene expression of the myosin heavy chain (MHC) family of motor proteins in mammalian cardiac and skeletal muscle. This was done in the context of examining parallel findings concerning the role that thyroid hormone (T(3), 3,5,3'-triiodothyronine) plays in MHC expression. Findings show that both cardiac and skeletal muscles of experimental animals are initially undifferentiated at birth and then undergo a marked level of growth and differentiation in attaining the adult MHC phenotype in a T(3)/activity level-dependent fashion. Cardiac MHC expression in small mammals is highly sensitive to thyroid deficiency, diabetes, energy deprivation, and hypertension; each of these interventions induces upregulation of the beta-MHC isoform, which functions to economize circulatory function in the face of altered energy demand. In skeletal muscle, hyperthyroidism, as well as interventions that unload or reduce the weight-bearing activity of the muscle, causes slow to fast MHC conversions. Fast to slow conversions, however, are seen under hypothyroidism or when the muscles either become chronically overloaded or subjected to intermittent loading as occurs during resistance training and endurance exercise. The regulation of MHC gene expression by T(3) or mechanical stimuli appears to be strongly regulated by transcriptional events, based on recent findings on transgenic models and animals transfected with promoter-reporter constructs. However, the mechanisms by which T(3) and mechanical stimuli exert their control on transcriptional processes appear to be different. Additional findings show that individual skeletal muscle fibers have the genetic machinery to express simultaneously all of the adult MHCs, e.g., slow type I and fast IIa, IIx, and IIb, in unique combinations under certain experimental conditions. This degree of heterogeneity among the individual fibers would ensure a large functional diversity in performing complex movement patterns. Future studies must now focus on 1) the signaling pathways and the underlying mechanisms governing the transcriptional/translational machinery that control this marked degree of plasticity and 2) the morphological organization and functional implications of the muscle fiber's capacity to express such a diversity of motor proteins.

  14. Dynamic coupling of regulated binding sites and cycling myosin heads in striated muscle.

    PubMed

    Campbell, Kenneth S

    2014-03-01

    In an activated muscle, binding sites on the thin filament and myosin heads switch frequently between different states. Because the status of the binding sites influences the status of the heads, and vice versa, the binding sites and myosin heads are dynamically coupled. The functional consequences of this coupling were investigated using MyoSim, a new computer model of muscle. MyoSim extends existing models based on Huxley-type distribution techniques by incorporating Ca(2+) activation and cooperative effects. It can also simulate arbitrary cross-bridge schemes set by the researcher. Initial calculations investigated the effects of altering the relative speeds of binding-site and cross-bridge kinetics, and of manipulating cooperative processes. Subsequent tests fitted simulated force records to experimental data recorded using permeabilized myocardial preparations. These calculations suggest that the rate of force development at maximum activation is limited by myosin cycling kinetics, whereas the rate at lower levels of activation is limited by how quickly binding sites become available. Additional tests investigated the behavior of transiently activated cells by driving simulations with experimentally recorded Ca(2+) signals. The unloaded shortening profile of a twitching myocyte could be reproduced using a model with two myosin states, cooperative activation, and strain-dependent kinetics. Collectively, these results demonstrate that dynamic coupling of binding sites and myosin heads is important for contractile function.

  15. Posttraining transcranial magnetic stimulation of striate cortex disrupts consolidation early in visual skill learning.

    PubMed

    De Weerd, Peter; Reithler, Joel; van de Ven, Vincent; Been, Marin; Jacobs, Christianne; Sack, Alexander T

    2012-02-01

    Practice-induced improvements in skilled performance reflect "offline " consolidation processes extending beyond daily training sessions. According to visual learning theories, an early, fast learning phase driven by high-level areas is followed by a late, asymptotic learning phase driven by low-level, retinotopic areas when higher resolution is required. Thus, low-level areas would not contribute to learning and offline consolidation until late learning. Recent studies have challenged this notion, demonstrating modified responses to trained stimuli in primary visual cortex (V1) and offline activity after very limited training. However, the behavioral relevance of modified V1 activity for offline consolidation of visual skill memory in V1 after early training sessions remains unclear. Here, we used neuronavigated transcranial magnetic stimulation (TMS) directed to a trained retinotopic V1 location to test for behaviorally relevant consolidation in human low-level visual cortex. Applying TMS to the trained V1 location within 45 min of the first or second training session strongly interfered with learning, as measured by impaired performance the next day. The interference was conditional on task context and occurred only when training in the location targeted by TMS was followed by training in a second location before TMS. In this condition, high-level areas may become coupled to the second location and uncoupled from the previously trained low-level representation, thereby rendering consolidation vulnerable to interference. Our data show that, during the earliest phases of skill learning in the lowest-level visual areas, a behaviorally relevant form of consolidation exists of which the robustness is controlled by high-level, contextual factors.

  16. Twitchin kinase interacts with MAPKAP kinase 2 in Caenorhabditis elegans striated muscle

    PubMed Central

    Matsunaga, Yohei; Qadota, Hiroshi; Furukawa, Miho; Choe, Heejoo (Helen); Benian, Guy M.

    2015-01-01

    In Caenorhabditis elegans, twitchin is a giant polypeptide located in muscle A-bands. The protein kinase of twitchin is autoinhibited by 45 residues upstream (NL) and 60 residues downstream (CRD) of the kinase catalytic core. Molecular dynamics simulation on a twitchin fragment revealed that the NL is released by pulling force. However, it is unclear how the CRD is removed. To identify proteins that may remove the CRD, we performed a yeast two-hybrid screen using twitchin kinase as bait. One interactor is MAK-1, C. elegans orthologue of MAPKAP kinase 2. MAPKAP kinase 2 is phosphorylated and activated by p38 MAP kinase. We demonstrate that the CRD of twitchin is important for binding to MAK-1. mak-1 is expressed in nematode body wall muscle, and antibodies to MAK-1 localize between and around Z-disk analogues and to the edge of A-bands. Whereas unc-22 mutants are completely resistant, mak-1 mutants are partially resistant to nicotine. MAK-1 can phosphorylate twitchin NL-Kin-CRD in vitro. Genetic data suggest the involvement of two other mak-1 paralogues and two orthologues of p38 MAP kinase. These results suggest that MAK-1 is an activator of twitchin kinase and that the p38 MAP kinase pathway may be involved in the regulation of twitchin. PMID:25851606

  17. The formation and regression of synapses during the re-innervation of axolotl striated muscles.

    PubMed Central

    Bennett, M R; Raftos, J

    1977-01-01

    1. A study has been made of the formation and regression of synapses formed by spinal nerves 16 and 17 in axolotl hind-limb flexor muscles following the severing of nerve 16, using histological, ultrastructural and electrophysiological techniques. 2. Axolotl hind-limb flexor myofibres possessed 'en plaque' end-plates from either spinal nerve 16 or 17 or both at intervals of about 1000 micronm along their length; the myofibre's length constant was about 700 micronm allowing electrophysiological observations of at least two of these synapses during a single impalement; transmitter release at these synapses could be described by binomial statistics and in a given set of ionic conditions the binomial statistic parameter n was directly proportional to the size of the nerve terminals whilst the binomial statistic parameter p was invariant to changes in nerve terminal size. 3. The distribution of synapses formed by spinal nerves 16 and 17 in different sectors of the axolotl hind-limb flexor muscles was determined from a study of evoked end-plate potentials; the middle and proximal sectors of the flexor muscles contained myofibres which received an innervation from nerve 16 only, whereas the sectors surrounding these contained myofibres innervated either by nerve 16 or nerve 17 or by both nerves. 4. Six days following the severing of spinal nerve 16, evoked transmitter release from the synapses formed by this nerve had failed; transmission was subsequently recorded at a few synapses formed by nerve 17 in the middle and proximal sectors of the flexor muscles which are not normally innervated by this nerve and these synapses had a low n; during the succeeding four weeks the value of n at the synapses increased to a size about 70% that of the terminals normally formed by nerve 16 at these sites. 5. Four weeks after severing nerve 16, myofibres which possessed synapses formed by nerve 17 also possessed synapses from re-innervating nerve 16 and these were sometimes formed at the same synaptic sites as those occupied by nerve 17. 6. In the subsequent sixteen weeks, the n value of synapses formed by nerve 17 declined whilst the n values of synapses formed by re-innervating nerve 16 on the same myofibres matured to their control size. 7. It is suggested that on severing nerve 16 collateral sprouting of nearby intact nerve 17 occurs and these collateral sprouts innervate the denervated synaptic sites, although the sprouts arenot as well matched to the denervated synaptic sites as are the original nerve terminals; thus if nerve 16 returns it preferentially forms synapses at its original synaptic sites, and the collateral synapses formed by nerve 17 regress. Images Plate 1 Plate 2 PMID:191597

  18. Electron microscopical and histochemical studies on the transverse striated muscles of birds after prolonged hypokinesis

    NASA Technical Reports Server (NTRS)

    Belak, M.; Kocisova, J.; Marcanik, J.; Boda, K.; Skarda, R.

    1981-01-01

    Studies of the gastrocnemius muscle were carried out in 4 month old cockerels of the laying hybrid after hypokinesis lasting 15 and 30 days. It was found that restricted movement resulted in dystrophic changes of myotibrils, enlargement of the sarcoplasmic reticulum and oedem of interfibrillar spaces. Histochemical studies revealed focuses of increased activity of non-specific esterase, decreased activity of dehydrogenase of lactic acid and a positive reaction of acid phosphatase.

  19. Triclosan impairs excitation-contraction coupling and Ca2+ dynamics in striated muscle.

    PubMed

    Cherednichenko, Gennady; Zhang, Rui; Bannister, Roger A; Timofeyev, Valeriy; Li, Ning; Fritsch, Erika B; Feng, Wei; Barrientos, Genaro C; Schebb, Nils H; Hammock, Bruce D; Beam, Kurt G; Chiamvimonvat, Nipavan; Pessah, Isaac N

    2012-08-28

    Triclosan (TCS), a high-production-volume chemical used as a bactericide in personal care products, is a priority pollutant of growing concern to human and environmental health. TCS is capable of altering the activity of type 1 ryanodine receptor (RyR1), but its potential to influence physiological excitation-contraction coupling (ECC) and muscle function has not been investigated. Here, we report that TCS impairs ECC of both cardiac and skeletal muscle in vitro and in vivo. TCS acutely depresses hemodynamics and grip strength in mice at doses ≥12.5 mg/kg i.p., and a concentration ≥0.52 μM in water compromises swimming performance in larval fathead minnow. In isolated ventricular cardiomyocytes, skeletal myotubes, and adult flexor digitorum brevis fibers TCS depresses electrically evoked ECC within ∼10-20 min. In myotubes, nanomolar to low micromolar TCS initially potentiates electrically evoked Ca(2+) transients followed by complete failure of ECC, independent of Ca(2+) store depletion or block of RyR1 channels. TCS also completely blocks excitation-coupled Ca(2+) entry. Voltage clamp experiments showed that TCS partially inhibits L-type Ca(2+) currents of cardiac and skeletal muscle, and [(3)H]PN200 binding to skeletal membranes is noncompetitively inhibited by TCS in the same concentration range that enhances [(3)H]ryanodine binding. TCS potently impairs orthograde and retrograde signaling between L-type Ca(2+) and RyR channels in skeletal muscle, and L-type Ca(2+) entry in cardiac muscle, revealing a mechanism by which TCS weakens cardiac and skeletal muscle contractility in a manner that may negatively impact muscle health, especially in susceptible populations.

  20. Androgens enhance in vivo 2-deoxyglucose uptake by rat striated muscle

    NASA Technical Reports Server (NTRS)

    Max, S. R.; Toop, J.

    1983-01-01

    It is shown that testosterone propionate (TP) causes a striking increase in the in vivo uptake of 2-deoxyglucose (2-DG) by the levator ani muscle of immature male rats, which was found to be uniformly distributed over the entire muscle. After a single subcutaneous injection of TP, no enhancement of 2-DG was observed before 3.5 hr, at which time uptake was increased 2-fold; maximum enhancement (4-fold) was attained at 12 hr. At 72 hr, 2-DG uptake remained elevated at twice the control value. It was determined that the effect of TP probably is mediated by specific androgen receptors. In addition, it was found that the effect of TP was blocked by the simultaneous administration of an androgen antagonist, cyproterone acetate. TP also was found to enhance the uptake of 2-DG in the bulbocavernosus (253 percent over control) and extensor digitorum longus muscles (150 percent over control), but not in the biceps brachii or soleus. It is suggested that the increased uptake of glucose may be an important early step in the anabolic response of muscle to androgens.

  1. Critical current density measurement of striated multifilament-coated conductors using a scanning Hall probe microscope

    NASA Astrophysics Data System (ADS)

    Li, Xiao-Fen; Kochat, Mehdi; Majkic, Goran; Selvamanickam, Venkat

    2016-08-01

    In this paper the authors succeeded in measuring the critical current density ({J}{{c}}) of multifilament-coated conductors (CCs) with thin filaments as low as 0.25 mm using the scanning hall probe microscope (SHPM) technique. A new iterative method of data analysis is developed to make the calculation of {J}{{c}} for thin filaments possible, even without a very small scan distance. The authors also discussed in detail the advantage and limitation of the iterative method using both simulation and experiment results. The results of the new method correspond well with the traditional fast Fourier transform method where this is still applicable. However, the new method is applicable for the filamentized CCs in much wider measurement conditions such as with thin filament and a large scan distance, thus overcoming the barrier for application of the SHPM technique on {J}{{c}} measurement of long filamentized CCs with narrow filaments.

  2. Neural Representations of Natural and Scrambled Movies Progressively Change from Rat Striate to Temporal Cortex

    PubMed Central

    Vinken, Kasper; Van den Bergh, Gert; Vermaercke, Ben; Op de Beeck, Hans P.

    2016-01-01

    In recent years, the rodent has come forward as a candidate model for investigating higher level visual abilities such as object vision. This view has been backed up substantially by evidence from behavioral studies that show rats can be trained to express visual object recognition and categorization capabilities. However, almost no studies have investigated the functional properties of rodent extrastriate visual cortex using stimuli that target object vision, leaving a gap compared with the primate literature. Therefore, we recorded single-neuron responses along a proposed ventral pathway in rat visual cortex to investigate hallmarks of primate neural object representations such as preference for intact versus scrambled stimuli and category-selectivity. We presented natural movies containing a rat or no rat as well as their phase-scrambled versions. Population analyses showed increased dissociation in representations of natural versus scrambled stimuli along the targeted stream, but without a clear preference for natural stimuli. Along the measured cortical hierarchy the neural response seemed to be driven increasingly by features that are not V1-like and destroyed by phase-scrambling. However, there was no evidence for category selectivity for the rat versus nonrat distinction. Together, these findings provide insights about differences and commonalities between rodent and primate visual cortex. PMID:27146315

  3. Fluid model of a single striated filament in an RF plasma jet at atmospheric pressure

    NASA Astrophysics Data System (ADS)

    Sigeneger, F.; Loffhagen, D.

    2016-06-01

    The filaments occurring in an RF argon atmospheric-pressure plasma jet are investigated by means of numerical modelling. The special setup of the jet leads to the establishment of filaments in very regular modes under certain conditions. Such a single filament generated in the active volume between the powered and grounded electrode is described by a time-dependent, spatially two-dimensional fluid model. This self-consistent model includes those mechanisms which can lead to constriction and stratification such as the heat balance equation and the dependence of electron collision rate coefficients on the ionization degree. A curved filament with a contracted radial profile of particle densities and very pronounced striations along its trace has been obtained by the model calculation for a typical discharge parameter condition of the plasma jet. The resulting calculated electron density and mean energy in the filament as well as the period length of the striations agree qualitatively with recent experimental observations. The analysis of the ionization budget makes clear that the constriction and stratification is mainly caused by the different nonlinear dependences of ionization and recombination rates on the electron density.

  4. [Localization of minor proteins and structural changes in the myosin filaments of vertebrate striated muscle].

    PubMed

    Lednev, V V; Srebnitskaia, L K; Kornev, A N; Khromov, A S; Malinchik, S B

    1981-01-01

    The origin of meridional reflections in the X-ray diffraction patterns of vertebrate skeletal muscles in resting and rigor states was studied. The main results may be summarized as follows. 1. Most of the meridional reflections localized in groups at the positions of successive orders of the repeat period of about 430 A are contributed mainly by the C-protein component of thick filaments. 2. The meridional reflections at about 143 and 72 A in the X-ray diffraction pattern of the resting muscle are contributed mainly by the cross-bridge axial repeat period, while in the X-ray diffraction patterns of the rigorized muscle the reflections at approximately the same positions are contributed mainly by C-protein. The change in the positions of these particular reflections accompanying the transition of the muscle from rest to rigor and from rest to contraction cannot be considered as an indication of a change in the axial repeat period of the cross-bridges, as it was earlier suggested by some authors. 3. The transition of the muscle from resting to rigor state is accompanied by substantial changes in the positions of the meridional reflections contributed my minor proteins, which is indicative of the structural transition in the thick filaments. The observed changes may be interpreted as the result of the thick filaments elongation by about 1.5% or, alternatively, as a consequence of the redistribution of electron density of the meridional reflections 215 and 143 A during a single twitch of the muscle (Huxley et al., Nature, 1980 284, 140) may be interpreted as a natural consequence of the structural change in the thick filaments. It is concluded therefore that on stimulation of the vertebrate skeletal muscle the thickness filaments undergo a reversible structural change which may reflect the existence of myosin-linked regulation in that type of muscle.

  5. Morphology and histology of chimpanzee primary visual striate cortex indicate that brain reorganization predated brain expansion in early hominid evolution.

    PubMed

    Holloway, Ralph L; Broadfield, Douglas C; Yuan, Michael S

    2003-07-01

    Human brain evolution is characterized by an overall increase in brain size, cerebral reorganization, and cerebral lateralization. It is generally understood when brain enlargement occurred during human evolution. However, issues concerning cerebral reorganization and hemispheric lateralization are more difficult to determine from brain endocasts, and they are topics of considerable debate. One region of the cerebral cortex that may represent the earliest evidence for brain reorganization is the primary visual cortex (PVC), or area 17 of Brodmann. In nonhuman primates, this region is larger in volume (demarcated anteriorly by the lunate sulcus), and extends further rostrally than it does in modern humans. In early hominid fossil (Australopithecus) endocasts, this region appears to occupy a smaller area compared to that in nonhuman primates. Some have argued that the brain first underwent size expansion prior to reorganization, while others maintain that reorganization predated brain expansion. To help resolve this question, we provide a description of two male, common chimpanzee (Pan troglodytes) brains, YN77-111 and YN92-115, which clearly display a more posterior lunate sulcal morphology than seen in other chimpanzees. These data show that neurogenetic variability exists in chimpanzees, and that significant differences in organization (e.g., a reduced PVC) can predate brain enlargement. While the human brain has experienced numerous expansion and reorganization events throughout evolution, the data from these two chimpanzees offer significant support for the hypothesis that the neurogenetic basis for brain reorganization was present in our early fossil ancestors (i.e., the australopithecines) prior to brain enlargement. PMID:12808644

  6. Expression of sarcomeric tropomyosin in striated muscles in axolotl treated with shz-1, a small cardiogenic molecule.

    PubMed

    Nan, Changlong; Dube, Syamalima; Matoq, Amr; Mikesell, Lauren; Abbott, Lynn; Alshiekh-Nasany, Ruham; Chionuma, Henry; Huang, Xupei; Poiesz, Bernard J; Dube, Dipak K

    2015-01-01

    We evaluated the effect of shz-1, a cardiogenic molecule, on the expression of various tropomyosin (TM) isoforms in the Mexican axolotl (Ambystoma mexicanum) hearts. qRT-PCR data show a ~1.5-fold increase in cardiac transcripts of the Nkx2.5 gene, which plays a crucial role in cardiogenesis in vertebrates. Shz-1 augments the expression of transcripts of the total sarcomeric TPM1 (both TPM1α & TPM1κ) and sarcomeric TPM4α. In order to understand the mechanism by which shz-1 augments the expression of sarcomeric TPM transcription in axolotl hearts, we transfected C2C12 cells with pGL3.axolotl. We transfected C2C12 cells with pGL3-axolotl TPM4 promoter constructs containing the firefly luciferase reporter gene. The transfected C2C12 cells were grown in the absence or presence of shz-1 (5 μM). Subsequently, we determined the firefly luciferase activity in the extracts of transfected cells. The results suggest that shz-1 activates the axolotl TPM4 promoter-driven ectopic expression in C2C12 cells. Also, we transfected C2C12 cells with a pGL3.1 vector containing the promoter of the mouse skeletal muscle troponin-I and observed a similar increase in the luciferase activity in shz-1-treated cells. We conclude that shz-1 activates the promoters of a variety of genes including axolotl TPM4. We have quantified the expression of the total sarcomeric TPM1 and observed a 1.5-fold increase in treated cells. Western blot analyses with CH1 monoclonal antibody specific for sarcomeric isoforms show that shz-1 does not increase the expression of TM protein in axolotl hearts, whereas it does in C2C12 cells. These findings support our hypothesis that cardiac TM expression in axolotl undergoes translational control.

  7. Response of the JAK-STAT pathway to mammalian hibernation in 13-lined ground squirrel striated muscle.

    PubMed

    Logan, Samantha M; Tessier, Shannon N; Tye, Joann; Storey, Kenneth B

    2016-03-01

    Over the course of the torpor-arousal cycle, hibernators must make behavioral, physiological, and molecular rearrangements in order to keep a very low metabolic rate and retain organ viability. 13-lined ground squirrels (Ictidomys tridecemlineatus) remain immobile during hibernation, and although the mechanisms of skeletal muscle survival are largely unknown, studies have shown minimal muscle loss in hibernating organisms. Additionally, the ground squirrel heart undergoes cold-stress, reversible cardiac hypertrophy, and ischemia-reperfusion without experiencing fatal impairment. This study examines the role of the Janus kinase-signal transducer and activator of transcription (JAK-STAT) signaling pathway in the regulation of cell stress in cardiac and skeletal muscles, comparing euthermic and hibernating ground squirrels. Immunoblots showed a fivefold decrease in JAK3 expression during torpor in skeletal muscle, along with increases in STAT3 and 5 phosphorylation and suppressors of cytokine signaling-1 (SOCS1) protein levels. Immunoblots also showed coordinated increases in STAT1, 3 and 5 phosphorylation and STAT1 inhibitor protein expression in cardiac muscle during torpor. PCR analysis revealed that the activation of these pro-survival signaling cascades did not result in coordinate changes in downstream genes such as anti-apoptotic B-cell lymphoma-2 (Bcl-2) family gene expression. Overall, these results indicate activation of the JAK-STAT pathway in both cardiac and skeletal muscles, suggesting a response to cellular stress during hibernation. PMID:26885984

  8. Computer-assisted morphometric analysis of intrinsic axon terminals in the supragranular layers of cat striate cortex.

    PubMed

    Gomes-Leal, Walace; Silva, G Jesus; Oliveira, Ricardo B; Picanço-Diniz, Cristovam W

    2002-07-01

    Qualitative and quantitative analyses of terminal arborizations of biocytin-labeled axon terminals were carried out in the cat primary visual cortex (V1). Extracellular iontophoretic injections of 5% biocytin were made into V1 of five adult cats. The animals were perfused 24-48 h after the injections. Labeled-axon fragments were considered to comprise two presumptive groups, according to the qualitative features, thickness, bouton features and appearance of terminal arbors. Forty axon fragments (20 for each presumptive group) were digitized using a microscope with motorized stage and a z-encoder, attached to a microcomputer. The densities of boutons, branching points and axon segments per mm of axon as well as axon segment length were used for comparison of the two groups. The two qualitative groups were confirmed to contain two axon types (I and II), according to cluster analysis of characteristics of the 40 axons in our sample. Forward stepwise discriminant analysis retained two variables as predictors of group membership: axonal length and bouton density. Parametric and non-parametric tests were employed for statistical comparisons (significance at P < 0.01). Type II axon fragments showed the greatest densities of boutons, axonal segments and branching points and the smallest values of length of segments ( P < 0.01). Both the qualitative and quantitative differences found for both types of axons suggest that they belong to different functional classes of neurons, namely spiny (type I) and smooth neurons (type II). Computer-assisted morphometric analysis of individual axon fragments seems to be a suitable approach with which different axon types can be objectively distinguished from each other.

  9. Expression of sarcomeric tropomyosin in striated muscles in axolotl treated with shz-1, a small cardiogenic molecule.

    PubMed

    Nan, Changlong; Dube, Syamalima; Matoq, Amr; Mikesell, Lauren; Abbott, Lynn; Alshiekh-Nasany, Ruham; Chionuma, Henry; Huang, Xupei; Poiesz, Bernard J; Dube, Dipak K

    2015-01-01

    We evaluated the effect of shz-1, a cardiogenic molecule, on the expression of various tropomyosin (TM) isoforms in the Mexican axolotl (Ambystoma mexicanum) hearts. qRT-PCR data show a ~1.5-fold increase in cardiac transcripts of the Nkx2.5 gene, which plays a crucial role in cardiogenesis in vertebrates. Shz-1 augments the expression of transcripts of the total sarcomeric TPM1 (both TPM1α & TPM1κ) and sarcomeric TPM4α. In order to understand the mechanism by which shz-1 augments the expression of sarcomeric TPM transcription in axolotl hearts, we transfected C2C12 cells with pGL3.axolotl. We transfected C2C12 cells with pGL3-axolotl TPM4 promoter constructs containing the firefly luciferase reporter gene. The transfected C2C12 cells were grown in the absence or presence of shz-1 (5 μM). Subsequently, we determined the firefly luciferase activity in the extracts of transfected cells. The results suggest that shz-1 activates the axolotl TPM4 promoter-driven ectopic expression in C2C12 cells. Also, we transfected C2C12 cells with a pGL3.1 vector containing the promoter of the mouse skeletal muscle troponin-I and observed a similar increase in the luciferase activity in shz-1-treated cells. We conclude that shz-1 activates the promoters of a variety of genes including axolotl TPM4. We have quantified the expression of the total sarcomeric TPM1 and observed a 1.5-fold increase in treated cells. Western blot analyses with CH1 monoclonal antibody specific for sarcomeric isoforms show that shz-1 does not increase the expression of TM protein in axolotl hearts, whereas it does in C2C12 cells. These findings support our hypothesis that cardiac TM expression in axolotl undergoes translational control. PMID:24958154

  10. Response of the JAK-STAT pathway to mammalian hibernation in 13-lined ground squirrel striated muscle.

    PubMed

    Logan, Samantha M; Tessier, Shannon N; Tye, Joann; Storey, Kenneth B

    2016-03-01

    Over the course of the torpor-arousal cycle, hibernators must make behavioral, physiological, and molecular rearrangements in order to keep a very low metabolic rate and retain organ viability. 13-lined ground squirrels (Ictidomys tridecemlineatus) remain immobile during hibernation, and although the mechanisms of skeletal muscle survival are largely unknown, studies have shown minimal muscle loss in hibernating organisms. Additionally, the ground squirrel heart undergoes cold-stress, reversible cardiac hypertrophy, and ischemia-reperfusion without experiencing fatal impairment. This study examines the role of the Janus kinase-signal transducer and activator of transcription (JAK-STAT) signaling pathway in the regulation of cell stress in cardiac and skeletal muscles, comparing euthermic and hibernating ground squirrels. Immunoblots showed a fivefold decrease in JAK3 expression during torpor in skeletal muscle, along with increases in STAT3 and 5 phosphorylation and suppressors of cytokine signaling-1 (SOCS1) protein levels. Immunoblots also showed coordinated increases in STAT1, 3 and 5 phosphorylation and STAT1 inhibitor protein expression in cardiac muscle during torpor. PCR analysis revealed that the activation of these pro-survival signaling cascades did not result in coordinate changes in downstream genes such as anti-apoptotic B-cell lymphoma-2 (Bcl-2) family gene expression. Overall, these results indicate activation of the JAK-STAT pathway in both cardiac and skeletal muscles, suggesting a response to cellular stress during hibernation.

  11. The disinhibitory zone of the striate neuron receptive field and its sensitivity to cross-like figures.

    PubMed

    Lazareva, N A; Shevelev, I A; Novikova, R V; Tikhomirov, A S; Sharaev, G A; Tsutskiridze, D Yu

    2002-01-01

    Acute experiments on immobilized anesthetized cats were used to confirm the suggestion that the sensitivity of many neurons on the primary visual cortex to cross-shaped, angular, and Y-shaped figures may be determined by the presence within their receptive fields of disinhibitory zones, which block end-stopping inhibition. A total of 55 neurons (84 functions, i.e.. on and off responses) were used for studies of sensitivity to crosses, and responses to single bars of different lengths were compared before and after stimulation of an additional lateral zone of the field (the presumptive disinhibitory zone), which was located in terms of responses to crosses. Seventeen of the 55 cells in which increases in the length of a single bar decreased responses, i.e., which demonstrated end-stopping inhibition, showed significant increases in responses (by an average factor of 2.06 +/- 0.16) during simultaneous stimulation of the lateral zone of the receptive field, which we interpreted as a disinhibitory effect on end-stopping inhibition. These data provide the first direct evidence for the role of end-stopping inhibition and its blockade by the disinhibitory zone of the receptive field in determining the sensitivity of some neurons in the primary visual cortex of the cat to cross-shaped figures.

  12. Some Relations between Changes in the Linear Electrical Properties of Striated Muscle Fibers and Changes in Ultrastructure

    PubMed Central

    Freygang, W. H.; Rapoport, S. I.; Peachey, L. D.

    1967-01-01

    Some of the linear electrical properties of frog sartorius muscle have been investigated in Ringer's fluid and in a Ringer fluid made hypertonic by the addition of sucrose or NaCl. Electrical constants were determined from measurements of the phase angle of the admittance of a fiber for an applied alternating current, from measurements of the voltage induced by an inward pulse of current, and from measurements of the conduction velocity of the action potential and the time constant of its foot. The dilation of the transverse tubular system induced by the sucrose hypertonic Ringer fluid was correlated with the change in the electrical constants. From this it is concluded that a two time constant equivalent circuit for the membrane, as proposed by Falk and Fatt, is in good agreement with our results. Both the area of the membrane of the transverse tubular system, and the capacity (ce) attributed to it, increased in the sucrose hypertonic Ringer fluid. The resistance re, which is in series with ce, did not fall when the transverse tubular system was dilated and probably is not located in that system. PMID:6063689

  13. Multi-Tasking Role of the Mechanosensing Protein Ankrd2 in the Signaling Network of Striated Muscle

    PubMed Central

    Mittempergher, Lorenza; Campanaro, Stefano; Martinelli, Valentina C.; Mouly, Vincent; Valle, Giorgio; Kojic, Snezana; Faulkner, Georgine

    2011-01-01

    Background Ankrd2 (also known as Arpp) together with Ankrd1/CARP and DARP are members of the MARP mechanosensing proteins that form a complex with titin (N2A)/calpain 3 protease/myopalladin. In muscle, Ankrd2 is located in the I-band of the sarcomere and moves to the nucleus of adjacent myofibers on muscle injury. In myoblasts it is predominantly in the nucleus and on differentiation shifts from the nucleus to the cytoplasm. In agreement with its role as a sensor it interacts both with sarcomeric proteins and transcription factors. Methodology/Principal Findings Expression profiling of endogenous Ankrd2 silenced in human myotubes was undertaken to elucidate its role as an intermediary in cell signaling pathways. Silencing Ankrd2 expression altered the expression of genes involved in both intercellular communication (cytokine-cytokine receptor interaction, endocytosis, focal adhesion, tight junction, gap junction and regulation of the actin cytoskeleton) and intracellular communication (calcium, insulin, MAPK, p53, TGF-β and Wnt signaling). The significance of Ankrd2 in cell signaling was strengthened by the fact that we were able to show for the first time that Nkx2.5 and p53 are upstream effectors of the Ankrd2 gene and that Ankrd1/CARP, another MARP member, can modulate the transcriptional ability of MyoD on the Ankrd2 promoter. Another novel finding was the interaction between Ankrd2 and proteins with PDZ and SH3 domains, further supporting its role in signaling. It is noteworthy that we demonstrated that transcription factors PAX6, LHX2, NFIL3 and MECP2, were able to bind both the Ankrd2 protein and its promoter indicating the presence of a regulatory feedback loop mechanism. Conclusions/Significance In conclusion we demonstrate that Ankrd2 is a potent regulator in muscle cells affecting a multitude of pathways and processes. PMID:22016770

  14. Primate striate and prestriate cortical neurons during discrimination. I. simultaneous temporal encoding of information about color and pattern.

    PubMed

    McClurkin, J W; Optican, L M

    1996-01-01

    1. We recorded the responses of neurons in cortical areas V1, V2, and V4 to a set of 36 colored patterns while monkeys discriminated among the stimuli on the basis of their color or their pattern. In the discrimination task a colored square or a black and white pattern was presented foveally as a cue stimulus. The monkey was required to choose, by making a saccade, which of three peripheral targets had the same property as the cue. One of the peripheral targets was centered on the receptive field of the neuron, and the other two were positioned at equally distant points around the circumference of an imaginary circle centered on the cue and passing through the receptive field. 2. An examination of the responses to the stimuli showed that there was a complex interaction between the effects of color and of pattern on the neuronal responses. Because of these interactions, we tested sensitivity to color and pattern by sorting the responses to all stimuli according to the color or pattern of the stimulus. We found that the number of spikes in the responses was affected by only one or the other of the stimulus parameters, but that the temporal distribution of spikes was affected by both stimulus parameters. We quantified the relative sensitivities of each neuron to color and pattern by dividing the amount of information the neuron transmitted about color by the amount of information the neuron transmitted about pattern. The distributions of information ratios assuming a spike count code were broad, indicating that many neurons were sensitive to only one stimulus parameter or the other. In contrast, the distributions of information ratios assuming a wave-form code were narrow and centered near 1.0, indicating nearly equal sensitivities to both stimulus parameters. 3. In our initial experiments, it appeared that the color or pattern used as the cue for the discrimination task affected the responses of many neurons to stimuli on the receptive field. To determine whether the cue effect was due to simple visual interactions or to the cognitive requirements of the discrimination task, we performed a control experiment in which the cue was turned on 80 ms after the peripheral stimuli. For many of the neurons in the control experiment, an effect related to the cue appeared in the response before the cue had been turned on. Thus the effect we observed must have been due to visual interactions with the distractor targets, even though these were outside the neuron's classically defined receptive field. 4. We compared the rate at which color and pattern information developed in the response over time assuming either a spike count or a waveform code. The spike count code gained more of its information in the first 20ms of the response than did the waveform code, but thereafter the information carried by the spike count code developed more slowly and reached a lower asymptote than did the information carried by the waveform code. 5. The waveform codes carried nearly equal amounts of information about color and pattern, but the messages about these two parameters did not develop at the same rate in all areas. The messages about color and pattern developed at the same rate in area V1, but messages about color developed more slowly than did the messages about pattern in areas V2 and V4. 6. These results offer a neurophysiological basis for both the psychological separateness of color and pattern, and the binding of color and pattern into a unified percept. We propose that the separateness of color and form arises not by virtue of their being encoded by different populations of neurons, but by virtue of their being encoded by separable waveform codes in the responses of single neurons. We propose that the binding of color and form occurs by virtue of their codes being multiplexed on the same neurons.

  15. Beyond Discourse? Using Deleuze and Guattari's Schizoanalysis to Explore Affective Assemblages, Heterosexually Striated Space, and Lines of Flight Online and at School

    ERIC Educational Resources Information Center

    Ringrose, Jessica

    2011-01-01

    This paper explores how Deleuze and Guattari's philosophical concepts extend and elaborate discursive and psychoanalytic interpretations of qualitative research findings. Analyzing data from a UK research project exploring young people's engagements with Social Networking Sites (SNSs), Deleuze and Guattari's schizoanalytic method is drawn upon to…

  16. Heterogeneity of neuromuscular junctions in striated muscle of human esophagus demonstrated by triple staining for the vesicular acetylcholine transporter, alpha-bungarotoxin, and acetylcholinesterase.

    PubMed

    Kallmünzer, Bernd; Sörensen, Björn; Neuhuber, Winfried L; Wörl, Jürgen

    2006-05-01

    During studies on enteric co-innervation in the human esophagus, we found that not all acetylcholinesterase (AChE)-positive motor endplates stained for alpha-bungarotoxin (alpha-BT) and the vesicular acetylcholine transporter (VAChT), respectively. Therefore, we probed for differences in neuromuscular junctions in human esophagus by using triple staining for VAChT, alpha-BT, and AChE followed by qualitative and quantitative analysis. To exclude that the results were caused by processing artifacts, we additionally examined the influence of a number of factors including post-mortem changes and the type and duration of fixation on the staining results. Four types of neuromuscular junction could be distinguished in human esophagus: type I with VAChT-positive and type II with VAChT-negative nerve terminals on a alpha-BT-positive and AChE-positive endplate area, type III with VAChT-positive nerve terminals on a alpha-BT-negative but AChE-positive endplate area, and type IV with VAChT-negative nerve terminals on a alpha-BT-negative but AChE-positive endplate area. On average, 32% of evaluated AChE-positive motor endplates were type I, 6% type II, 24% type III, and 38% type IV. Based on these results, we suggest that, in human esophagus, (1) the most reliable method for staining motor endplates is presently AChE histochemistry, (2) alpha-BT-sensitive and alpha-BT-resistant nicotinic acetylcholine receptors exist in neuromuscular junctions, and (3) different types of VAChT or transport mechanisms for acetylcholine probably exist in neuromuscular junctions.

  17. [Electric activity of striated muscles of the cervical part of the rabbit esophagus under conditions of hunger, food intake and satiation].

    PubMed

    Kromin, A A

    1990-07-01

    The experiments of free-moving rabbits have shown that the muscles of the proximal zone in the esophageal cervical part functions as the superior esophageal sphincter. In hunger stage the motor unit activity of the sphincter has regular low-amplitude discharge with monomodal distribution of interspike intervals. The process of food satisfaction leads to the appearance of burst-like unit activity with bimodal distribution of interspike intervals. During the food intake reorganization of the motor unit activity of the esophageal cervical part is manifested in characteristic patterns of interspike interval distribution.

  18. Immunological localization of ribosomes in striated rat muscle. Evidence for myofibrillar association and ontological changes in the subsarcolemmal:myofibrillar distribution.

    PubMed Central

    Horne, Z; Hesketh, J

    1990-01-01

    Ribosome distribution in skeletal-muscle fibres was investigated immunohistochemically by using polyclonal antibodies raised against large-ribosomal-subunit proteins isolated from rat liver. Immunoblot analysis showed the antibodies to recognize five major proteins of the large subunit; these were identified as L4, L6, L7, L15 and L17 by two-dimensional electrophoresis. Immunohistochemistry of frozen rat skeletal-muscle sections showed staining of both the subsarcolemmal and intermyofibrillar cytoplasm. A distinct banding pattern was observed, and when peroxidase and phase-contrast images of the same field were compared by image analysis the anti-ribosome staining was found to correspond to the A-bands. These results suggest that a proportion of muscle ribosomes are present in the myofibrillar cytoplasm in a regular fashion, possibly associated with myosin. Densitometric analysis of the peroxidase immunostaining showed that the ratio of myofibrillar to sub-sarcolemmal ribosomal material was lower in muscle from 51-day-old rats compared with those from 14-day-old animals. Images Fig. 3. Fig. 4. Fig. 5. Fig. 6. PMID:2188648

  19. Relative contributions of 2D and 3D cues in a texture segmentation task, implications for the roles of striate and extrastriate cortex in attentional selection.

    PubMed

    Zhaoping, Li; Guyader, Nathalie; Lewis, Alex

    2009-01-01

    Experimental evidence has given strong support to the theory that the primary visual cortex (V1) realizes a bottom-up saliency map (A. R. Koene & L. Zhaoping, 2007; Z. Li, 2002; L. Zhaoping, 2008a; L. Zhaoping & K. A. May, 2007). Unlike the conventional models of texture segmentation, this theory predicted that segmenting two textures in an image I(rel) comprising obliquely oriented bars would become much more difficult when a task-irrelevant texture I(ir) of spatially alternating horizontal and vertical bars is superposed on the original texture I(rel). The irrelevant texture I(ir) interferes with I(rel)'s ability to direct attention. This predicted interference was confirmed (L. Zhaoping & K. A. May, 2007) in the form of a prolonged task reaction time (RT). In this study, we investigate whether and how 3D depth perception, believed to be processed mostly beyond V1 and starting in V2 (J. S. Bakin, K. Nakayama, & C. D. Gilbert, 2000; B. G. Cumming & A. J. Parker, 2000; F. T. Qiu & R. von der Heydt, 2005; R. von der Heydt, H. Zhou, & H. S. Friedman, 2000), contribute additionally to direct attention. We measured the reduction of the interference or the RT when the position of the texture grid for I(ir) was offset horizontally from that for I(rel), forming an offset, 2D, stimulus. This reduction was compared with that when this positional offset was only present in the input image to one eye, or when it was in the opposite directions in the images for the two eyes, creating a 3D stimulus with a depth separation between I(ir) and I(rel). The contribution by 3D processes to attentional guidance would be manifested by any extra RT reduction associated with the 3D stimulus over the offset 2D stimulus. This 3D contribution was not present unless the task was so difficult that RT (by button press) based on 2D cues alone was longer than about 1 second. Our findings suggest that, without other top-down factors, V1 plays a dominant role in attentional guidance during an initial window of processing, while cortical areas beyond V1 play an increasing role in later processing. Subject-dependent variations in the manifestations of the 3D effects also suggest that this later, 3D, contribution to attentional guidance can be easily influenced by top-down control.

  20. Hand-Held Model of a Sarcomere to Illustrate the Sliding Filament Mechanism in Muscle Contraction

    ERIC Educational Resources Information Center

    Jittivadhna, Karnyupha; Ruenwongsa, Pintip; Panijpan, Bhinyo

    2009-01-01

    From our teaching of the contractile unit of the striated muscle, we have found limitations in using textbook illustrations of sarcomere structure and its related dynamic molecular physiological details. A hand-held model of a striated muscle sarcomere made from common items has thus been made by us to enhance students' understanding of the…

  1. Skeletal muscle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There are approximately 650-850 muscles in the human body these include skeletal (striated), smooth and cardiac muscle. The approximation is based on what some anatomists consider separate muscle or muscle systems. Muscles are classified based on their anatomy (striated vs. smooth) and if they are v...

  2. Disassembly of myofibrils in adult cardiomyocytes during dedifferentiation

    NASA Astrophysics Data System (ADS)

    Liu, Honghai; Qin, Wan; Shao, Yonghong; Wang, Zhonghai; Yang, Huaxiao; Runyan, Raymond B.; Borg, Thomas K.; Gao, Bruce

    2013-02-01

    Using hybrid TPEF-SHG imaging and immunocytological techniques, we studied dedifferentiation of adult cardiomyocytes. First, the myofibrils shrank to shorten the sarcomere length. At the cell ends, the striated pattern of myosin filaments began to dissociate; at the center of the cell, the striated pattern of alpha-actinin first faded away and reappeared near the cell membrane during dedifferentiation. The results suggest that when freshly isolated adult cardiomyocytes are used to model cardiac muscle, the end-to-end connection may be important to maintain their striated myofibrillar structure and rod-shape morphology.

  3. Types of muscle tissue (image)

    MedlinePlus

    The 3 types of muscle tissue are cardiac, smooth, and skeletal. Cardiac muscle cells are located in ... heart, appear striated, and are under involuntary control. Smooth muscle fibers are located in walls of hollow ...

  4. Insights from diploblasts; the evolution of mesoderm and muscle.

    PubMed

    Burton, Patrick Michael

    2008-01-15

    The origin of both mesoderm and muscle are central questions in metazoan evolution. The majority of metazoan phyla are triploblasts, possessing three discrete germ layers. Attention has therefore been focused on two outgroups to triploblasts, Cnidaria and Ctenophora. Modern texts describe these taxa as diploblasts, lacking a mesodermal germ layer. However, some members of Medusozoa, one of two subphyla within Cnidaria, possess tissue independent of either the ectoderm or endoderm referred to as the entocodon. Furthermore, members of both Cnidaria and Ctenophora have been described as possessing striated muscle, a mesodermal derivative. While it is widely accepted that the ancestor of Eumetazoa was diploblastic, homology of the entocodon and mesoderm as well as striated muscle within Eumetazoa has been suggested. This implies a potential triploblastic ancestor of Eumetazoa possessing striated muscle. In the following review, I examine the evidence for homology of both muscle and mesoderm. Current data support a diploblastic ancestor of cnidarians, ctenophores, and triploblasts lacking striated muscle.

  5. Midline cervical cleft. A case report.

    PubMed

    Ikuzawa, M; Matsumoto, K; Amino, K; Sakuda, M

    1992-10-01

    A case of incomplete midline cervical cleft of the upper neck is reported. It showed histological resemblance to a mature teratoma with three different germ-cell components, including cartilage, striated muscles, small salivary glands, and nerves.

  6. The musculature and pupillary response of the great horned owl iris.

    PubMed

    Oliphant, L W; Johnson, M R; Murphy, C; Howland, H

    1983-12-01

    There is considerable confusion in the literature regarding the nature of the musculature of the avian iris. The most commonly held view is that both the sphincter and dilator are striated. The iris of the Great Horned Owl (Bubo virginianus) has a complex iridial musculature consisting of three circumferential components (a myoepithelium, smooth muscle and striated muscle) and two radial components (a well-developed myoepithelium and a few striated fibers). On the basis of the anatomy and relative development of these components, and a quantitative analysis of the pupillary reflex, it is proposed that the circumferential striated muscle is the primary pupillary constrictor and radial myoepithelium is the primary dilator. The annular band of smooth muscle may play an important role in maintaining pupillary size. PMID:6662207

  7. Botulinum toxin in the treatment of chronic urinary retention in women.

    PubMed

    Fowler, C J; Betts, C D; Christmas, T J; Swash, M; Fowler, C G

    1992-10-01

    Six women were identified as having difficulty in voiding or complete urinary retention due to abnormal myotonic-like electromyographic (EMG) activity in the striated muscle of the urethral sphincter. An attempt was made to improve voiding by injection of botulinum toxin into the striated sphincter muscle. Although 3 patients then developed transient stress incontinence, demonstrating that sufficient botulinum toxin had been given to cause sphincter weakness, no patient had significant symptomatic benefit.

  8. Host Chemical Footprints Induce Host Sex Discrimination Ability in Egg Parasitoids

    PubMed Central

    Peri, Ezio; Frati, Francesca; Salerno, Gianandrea; Conti, Eric; Colazza, Stefano

    2013-01-01

    Trissolcus egg parasitoids, when perceiving the chemical footprints left on a substrate by pentatomid host bugs, adopt a motivated searching behaviour characterized by longer searching time on patches were signals are present. Once in contact with host chemical footprints, Trissolcus wasps search longer on traces left by associated hosts rather than non-associated species, and, in the former case, they search longer on traces left by females than males. Based on these evidences, we hypothesized that only associated hosts induce the ability to discriminate host sex in wasps. To test this hypothesis we investigated the ability of Trissolcus basalis, T. brochymenae, and Trissolcus sp. to distinguish female from male Nezara viridula, Murgantia histrionica, and Graphosoma semipunctatum footprints. These three pentatomid bugs were selected according to variable association levels. Bioassays were conducted on filter paper sheets, and on Brassica oleracea (broccoli) leaves. The results confirmed our hypothesis showing that wasps spent significantly more time on female rather than male traces left by associated hosts on both substrates. No differences were observed in the presence of traces left by non-associated hosts. The ecological consequences for parasitoid host location behaviour are discussed. PMID:24244417

  9. Translational control of tropomyosin expression in vertebrate hearts.

    PubMed

    Dube, Dipak K; McLean, Matthew D; Dube, Syamalima; Poiesz, Bernard J

    2014-09-01

    The tropomyosin (TM) gene family produces a set of related TM proteins with important functions in striated and smooth muscle, and nonmuscle cells. In vertebrate striated muscle, the thin filament consists largely of actin, TM, the troponin (Tn) complex (Tn-I, Tn-C and Tn-T), and tropomodulin (Tmod) and is responsible for mediating Ca(2+) control of muscle contraction and relaxation. There are four known genes (designated as TPM1, TPM2, TPM3, and TPM4) for TM in vertebrates. The four TM genes generate a multitude of tissue- and developmental-specific isoforms through the use of different promoters, alternative mRNA splicing, different 3'-end mRNA processing and tissue-specific translational control. In this review, we have focused mainly on the regulation of TM expression in striated muscles, primarily in vertebrate hearts with special emphasis on translational control using mouse and Mexican axolotl animal models. PMID:25125172

  10. Braille alexia during visual hallucination in a blind man with selective calcarine atrophy.

    PubMed

    Maeda, Kengo; Yasuda, Hitoshi; Haneda, Masakazu; Kashiwagi, Atsunori

    2003-04-01

    The case of a 56-year-old man who has been blind for 25 years due to retinal degeneration is herein described. The patient complained of elementary visual hallucination, during which it was difficult for him to read Braille. Brain magnetic resonance imaging showed marked atrophy of the bilateral striate cortex. Visual hallucination as a release phenomenon of the primary visual cortex has never been reported to cause alexia for Braille. The present case supports the results of recent functional imaging studies of the recruitment of striate and prestriate cortex for Braille reading.

  11. The detection and mapping of the spatial distribution of insect defense compounds by desorption atmospheric pressure photoionization Orbitrap mass spectrometry.

    PubMed

    Rejšek, Jan; Vrkoslav, Vladimír; Hanus, Robert; Vaikkinen, Anu; Haapala, Markus; Kauppila, Tiina J; Kostiainen, Risto; Cvačka, Josef

    2015-07-30

    Many insects use chemicals synthesized in exocrine glands and stored in reservoirs to protect themselves. Two chemically defended insects were used as models for the development of a new rapid analytical method based on desorption atmospheric pressure photoionization-mass spectrometry (DAPPI-MS). The distribution of defensive chemicals on the insect body surface was studied. Since these chemicals are predominantly nonpolar, DAPPI was a suitable analytical method. Repeatability of DAPPI-MS signals and effects related to non-planarity and roughness of samples were investigated using acrylic sheets uniformly covered with an analyte. After that, analytical figures of merit of the technique were determined. The spatial distribution of (E)-1-nitropentadec-1-ene, a toxic nitro compound synthesized by soldiers of the termite Prorhinotermes simplex, was investigated. Then, the spatial distribution of the unsaturated aldehydes (E)-hex-2-enal, (E)-4-oxohex-2-enal, (E)-oct-2-enal, (E,E)-deca-2,4-dienal and (E)-dec-2-enal was monitored in the stink bug Graphosoma lineatum. Chemicals present on the body surface were scanned along the median line of the insect from the head to the abdomen and vice versa, employing either the MS or MS(2) mode. In this fast and simple way, the opening of the frontal gland on the frons of termite soldiers and the position of the frontal gland reservoir, extending deep into the abdominal cavity, were localized. In the stink bug, the opening of the metathoracic scent glands (ostiole) on the ventral side of the thorax as well as the gland reservoir in the median position under the ventral surface of the anterior abdomen were detected and localized. The developed method has future prospects in routine laboratory use in life sciences. PMID:26320640

  12. The detection and mapping of the spatial distribution of insect defense compounds by desorption atmospheric pressure photoionization Orbitrap mass spectrometry.

    PubMed

    Rejšek, Jan; Vrkoslav, Vladimír; Hanus, Robert; Vaikkinen, Anu; Haapala, Markus; Kauppila, Tiina J; Kostiainen, Risto; Cvačka, Josef

    2015-07-30

    Many insects use chemicals synthesized in exocrine glands and stored in reservoirs to protect themselves. Two chemically defended insects were used as models for the development of a new rapid analytical method based on desorption atmospheric pressure photoionization-mass spectrometry (DAPPI-MS). The distribution of defensive chemicals on the insect body surface was studied. Since these chemicals are predominantly nonpolar, DAPPI was a suitable analytical method. Repeatability of DAPPI-MS signals and effects related to non-planarity and roughness of samples were investigated using acrylic sheets uniformly covered with an analyte. After that, analytical figures of merit of the technique were determined. The spatial distribution of (E)-1-nitropentadec-1-ene, a toxic nitro compound synthesized by soldiers of the termite Prorhinotermes simplex, was investigated. Then, the spatial distribution of the unsaturated aldehydes (E)-hex-2-enal, (E)-4-oxohex-2-enal, (E)-oct-2-enal, (E,E)-deca-2,4-dienal and (E)-dec-2-enal was monitored in the stink bug Graphosoma lineatum. Chemicals present on the body surface were scanned along the median line of the insect from the head to the abdomen and vice versa, employing either the MS or MS(2) mode. In this fast and simple way, the opening of the frontal gland on the frons of termite soldiers and the position of the frontal gland reservoir, extending deep into the abdominal cavity, were localized. In the stink bug, the opening of the metathoracic scent glands (ostiole) on the ventral side of the thorax as well as the gland reservoir in the median position under the ventral surface of the anterior abdomen were detected and localized. The developed method has future prospects in routine laboratory use in life sciences.

  13. Two distinct myosin II populations coordinate ovulatory contraction of the myoepithelial sheath in the Caenorhabditis elegans somatic gonad

    PubMed Central

    Ono, Kanako; Ono, Shoichiro

    2016-01-01

    The myoepithelial sheath in the somatic gonad of the nematode Caenorhabditis elegans has nonstriated contractile actomyosin networks that produce highly coordinated contractility for ovulation of mature oocytes. Two myosin heavy chains are expressed in the myoepithelial sheath, which are also expressed in the body-wall striated muscle. The troponin/tropomyosin system is also present and essential for ovulation. Therefore, although the myoepithelial sheath has smooth muscle–like contractile apparatuses, it has a striated muscle–like regulatory mechanism through troponin/tropomyosin. Here we report that the myoepithelial sheath has a distinct myosin population containing nonmuscle myosin II isoforms, which is regulated by phosphorylation and essential for ovulation. MLC-4, a nonmuscle myosin regulatory light chain, localizes to small punctate structures and does not colocalize with large, needle-like myosin filaments containing MYO-3, a striated-muscle myosin isoform. RNA interference of MLC-4, as well as of its upstream regulators, LET-502 (Rho-associated coiled-coil forming kinase) and MEL-11 (a myosin-binding subunit of myosin phosphatase), impairs ovulation. Expression of a phosphomimetic MLC-4 mutant mimicking a constitutively active state also impairs ovulation. A striated-muscle myosin (UNC-54) appears to provide partially compensatory contractility. Thus the results indicate that the two spatially distinct myosin II populations coordinately regulate ovulatory contraction of the myoepithelial sheath. PMID:26864628

  14. New evidence for mid-Pliocene-early Pleistocene glaciation in the northern Patagonian Andes Argentina

    SciTech Connect

    Stephens, G.C.; Evenson, E.B.; Rabassa, J.

    1985-01-01

    Mount Tronador is an extinct, glacially eroded strato-volcano located in the northern Patagonian Andes. With a summit elevation of 3556 m, Mount Tronador lies mostly above the present regional snowline (2000 m) and is largely covered by extensive snow fields and glaciers. The rocks of Mount Tronador comprise the Tronador Formation, a 2000 m thick sequence of interlayered basalts, andesites, ignimbrites, agglomerates, volcanic mudflows and lahars. This volcanic edifice is built on an erosional land surface of Tertiary age. Three K-Ar dates from the Tronador Formation yield radiometric ages of 3.2, 0.34 and 0.18 m.y. Striated clasts have been found included in several large glacial boulders derived from volcanic mudflows and lahars of the Tronador Fm. These boulders have been eroded by the Rio Manso Glacier and deposited in its Neoglacial moraines. The lahar boulders themselves contain pebbles and boulders of andesitic rocks in a vitroclastic matrix of pyroclastic origin. The striated clasts are well-rounded, shaped and polished, and the striations can be traced beneath the volcanic matrix. Thus these striated clasts represent a pre-Holocene cycle of glaciation. Mercer (1976) and Ciesielski (1982) document glaciations from southern Patagonia (2.1-3.5 m.y.) and from the southwestern Atlantic (2.1-3.9 m.y.) respectively. The discovery of striated clasts in lahars and mudflows of the Tronador Fm. indicates the existence of a heretofore undocumented Pliocene-Pleistocene glaciation in northern Patagonia.

  15. Revision of the Genus Corallomycetella with Corallonectria gen. nov. for C. jatrophae (Nectriaceae, Hypocreales)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The genus Corallomycetella (Ascomycota, Sordariomycetes, Hypocreales, Nectriaceae) has been defined to include red nectrioid fungi associated with rhizomorphs in nature and culture. With the recent collection of an unusual specimen having striated ascospores, the genus was re-examined using this and...

  16. A leiomyoma arising from the deep palmar arterial arch.

    PubMed

    Yagi, K; Hamada, Y; Yasui, N

    2006-12-01

    Vascular leiomyomas, or angioleiomyomas, are benign tumours originating from smooth non-striated muscle. Leiomyomas in the hand are uncommon and their pre-operative diagnosis is difficult. We report a 65 year-old woman who developed a vascular leiomyoma arising from the deep palmar arterial arch.

  17. Comparison of sensory descriptive texture attributes of broiler breast fillets with different degree of white striping

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The white striping condition in chicken meat, known as the presence of white striated tissue in the muscle of breast or thighs, is currently an emerging concern to the chicken processing industry. This condition, negatively affecting appearance in retail chicken and consumer buying decision, but no...

  18. The Development of Luminance- and Texture-Defined Form Perception during the School-Aged Years

    ERIC Educational Resources Information Center

    Bertone, Armando; Hanck, Julie; Guy, Jacalyn; Cornish, Kim

    2010-01-01

    The objective of the present study was to assess the development of luminance- and texture-defined static form perception in school-aged children. This was done using an adapted Landolt-C technique where C-optotypes were defined by either luminance or texture information, the latter necessitating extra-striate neural processing to be perceived.…

  19. Improving Generalisation Skills in a Neural Network on the Basis of Neurophysiological Data

    ERIC Educational Resources Information Center

    Mermillod, M.; Chauvin, A.; Guyader, N.

    2005-01-01

    The distribution of striate cortex cells exhibits a maximum number of cells tuned to vertical and horizontal orientations (Mansfield, 1974). This was interpreted as an adaptation of the visual system to the presence in the visual environment of greater amounts of vertical and horizontal information compared to information from other orientations…

  20. Unusual clinic presentation of polyarteritis nodosa: involvement of axillary and brachial artery.

    PubMed

    Kocyigit, Ismail; Koyuncu, Sumeyra; Mavili, Ertugrul; Unal, Aydin; Tokmak, Turgut Tursem; Cilan, Havva; Kavuncuoglu, Feridun; Oymak, Oktay; Utas, Cengiz

    2011-01-01

    Polyarteritis nodosa (PAN) is a necrotizing inflammatory vasculitis of small- and medium-sized muscular arteries. Multiple organs, especially the kidney, skin, peripheric nerves, striated muscles, and intestine, are affected. In this case report, a patient with renal and hepatic involvement and axillary and brachial artery aneurysm resulting in shoulder hematoma and pain due to underlying PAN is presented.

  1. Subcortical Modulation of Spatial Attention Including Evidence that the Sprague Effect Extends to Man

    ERIC Educational Resources Information Center

    Weddell, Rodger A.

    2004-01-01

    The Sprague effect is well-established--small tectal lesions restore visual orientation in the hemianopic field of animals with extensive unilateral geniculo-striate lesions. Studies of human midbrain visual functions are rare. This man with a midbrain tumour developed left-neglect through subsequent right frontal damage. Bilateral orientation…

  2. Smoothness and Striation in Digital Learning Spaces

    ERIC Educational Resources Information Center

    Bayne, Sian

    2004-01-01

    It is Deleuze & Guattari's description of smooth and striated cultural spaces (Deleuze & Guattari, 1988) which informs this exploration of pedagogical alternatives within the learning environments of cyberspace. Digital spaces work to constitute subject and text in ways which are distinct, and it is awareness of this distinctiveness which must…

  3. Biofeedback for Developing Self-Control of Tension and Stress in One's Hierarchy of Psychological States.

    ERIC Educational Resources Information Center

    Cassel, Russell

    1985-01-01

    Describes six stage hierarchial patterns in the development of self-control through biofeedback. The stages include Skeletal and Striated Muscle Tension; Visceral Involvement-Anxiety Neuroses; Chronic Physiological Dysfunctioning; Decision Making Competency; Twilight Learning-Permissive Concentration; and Autogenic Feedback Training. (BL)

  4. Mechanism of toxicity of MPTP: A cause of Parkinsonism in human beings

    SciTech Connect

    Denton, T.L.

    1988-01-01

    1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) was found in 1983 to cause a syndrome virtually identical to Parkinson's Disease in humans and other primates. The symptoms, as in idiopathic Parkinson's syndrome, are due to destruction of dopaminergic neurons in the pars compacta of the substantia nigra resulting in depletion of dopamine in the basal ganglia. The mechanism of toxicity was investigated with a dopamine containing cell line, PC12, a MPTP resistant variant (MPTP{sup r}), and synaptosomes from the striate cortex of mice, rats, guinea pigs and a monkey. The mechanism of acute effects was studied with membrane preparations from human and rat striate cortex. MPTP displaced ({sup 3}H)haloperidol from binding sites in human and rat striate cortex, but could not displace ({sup 3}H)flupenthixol, suggesting that MPTP is a D2 receptor ligand of equivalent potency in both species. MPTP was a competitive inhibitor of uptake of ({sup 3}H)dopamine in PC12 but did not accumulate in PC12 or in synaptosomes of rat, guinea pig, mouse or monkey striate cortex. 100 uM MPTP depleted catecholamine levels in PC12 cells by about 50%, without killing.

  5. Nomads with Maps: Musical Connections in a Glocalized World

    ERIC Educational Resources Information Center

    Richerme, Lauren Kapalka

    2013-01-01

    This article presents the author's views on the concepts of the philosophers Deleuze and Guattari on striated (sedentary) space and smooth (mobile) space, asserting that "nomads" can move freely about their space. She relates these concepts to music education, incorporating Deleuze and Guattari's concept of mapping as it…

  6. Volcanic twilights from the fuego eruption.

    PubMed

    Volz, F E

    1975-07-01

    Striated twilight glows have been observed since 26 November 1974 in New England, indicating the spread of stratospheric dust earlier observed over Arizona. Similar photometric results were obtained from New Mexico and Florida, and twilights in Puerto Rico showed features not hitherto measured. Letters and verbal reports indicate the source to be eruptions of Fuego Volcano in Guatemala between 13 and 23 October 1974.

  7. Molecular Characterization of TGF-β Type I Receptor Gene (Tgfbr1) in Chlamys farreri, and the Association of Allelic Variants with Growth Traits

    PubMed Central

    Guo, Huihui; Bao, Zhenmin; Li, Jiqin; Lian, Shanshan; Wang, Shi; He, Yan; Fu, Xiaoteng; Zhang, Lingling; Hu, Xiaoli

    2012-01-01

    Background Scallops are an economically important aquaculture species in Asian countries, and growth-rate improvement is one of the main focuses of scallop breeding. Investigating the genetic regulation of scallop growth could benefit scallop breeding, as such research is currently limited. The transforming growth factor beta (TGF-β) signaling through type I and type II receptors, plays critical roles in regulating cell proliferation and growth, and is thus a plausible candidate growth regulator in scallops. Results We cloned and characterized the TGF-β type I receptor (Tgfbr1) gene from Zhikong scallops (Chlamys farreri). The deduced amino acid sequence contains characteristic residues and exhibits the conserved structure of Tgfbr1 proteins. A high expression level of scallop Tgfbr1 was detected during early embryonic stages, whereas Tgfbr1 expression was enriched in the gonad and striated muscle in adults. A single nucleotide polymorphism (SNP, c. 1815C>T) in the 3′ UTR was identified. Scallops with genotype TT had higher growth traits values than those with genotype CC or CT in a full-sib family, and significant differences were found between genotypes CC and TT for shell length, shell height, and striated muscle weight. An expression analysis detected significantly more Tgfbr1 transcripts in the striated muscle of scallops with genotype CC compared to those with genotype TT or CT. Further evaluation in a population also revealed higher striated muscle weight in scallops with genotype TT than those with the other two genotypes. The inverse correlation between striated muscle mass and Tgfbr1 expression is consistent with TGF-β signaling having a negative effect on cell growth. Conclusion The scallop Tgfbr1 gene was cloned and characterized, and an SNP potentially associated with both scallop growth and Tgfbr1 expression was identified. Our results suggest the negative regulation of Tgfbr1 in scallop growth and provide a candidate marker for Zhikong scallop

  8. Studies on kallikrein in the duct systems of the salivary glands of the cat

    PubMed Central

    Shnitka, †T. K.; Maranda, B.; Rodrigues, J. A. A.; Schachter, M.; Weinberg, J.

    1978-01-01

    By correlating immunofluorescence light microscopy with electron microscope studies and with kallikrein concentrations under various conditions, we have made the following observations and conclusions about kallikrein in the submandibular and other salivary glands. 1. In the submandibular gland, specific immunofluorescence to kallikrein was observed in the luminal region of the striated ducts particularly, but also in the outer epithelial cells of the stratified epithelial collecting ducts. Sympathetic nerve stimulation resulted in a reduction in intensity of specific fluorescence and in its increased localization towards the lumen. The nearly complete elimination of kallikrein from the gland by duct obstruction for four days resulted in complete disappearance of specific fluorescence in the gland. Prolonged parasympathetic nerve stimulation at frequencies which did not reduce the kallikrein concentration of the gland failed to alter the specific immunofluorescence despite copious secretion of saliva. Our results failed to reveal evidence of secretion of kallikrein either into or towards the interstitium of the gland. The luminal layer of stratified epithelial cells in the collecting ducts contained small secretory granules closely resembling those in the striated ducts. Our results are not conclusive, but do suggest that kallikrein is located in these granules whence it is secreted into the lumen of the duct. 2. The parotid gland was found to contain much lower concentrations of kallikrein than the submandibular gland. This finding was associated with the presence of far fewer striated ducts in the parotid gland. Otherwise, specific fluorescence and the response to sympathetic nerve stimulation was like that of the submandibular gland. Small secretory granules in the striated and collecting ducts resembled those of the submandibular gland. 3. The sublingual gland, like the parotid, had a low concentration of kallikrein and very few striated ducts. These ducts were

  9. Freeze-fracture surface of salivary glands of rat observed by scanning electron microscopy.

    PubMed

    Espinal, E G; Ubios, A M; Cabrini, R L

    1983-01-01

    The structure of parenchymal components of rat submandibular glands observed with scanning electron microscopy is presented. The glands were fixed, submerged in liquid nitrogen, cryofractured, dehydrated and critical-point-dried. The fracture surface displayed the acini, granular ducts and striated ducts. Acini exhibit a typical sponge-like pattern of irregular and empty cavities. Granular ducts are lined by bulging cells laden with numerous secretory granules. Their diameter ranged from 0.2 to 3.2 microns, with a mean value of 1.240.4 microns. Measurement of the actual granules was rendered possible by direct observation. Striated ducts exhibited a cribiform pattern near the basal cell region which corresponds to infoldings of the basal cell membrane. PMID:6637370

  10. Microdistribution of oxygen in silicon

    NASA Technical Reports Server (NTRS)

    Murgai, A.; Chi, J. Y.; Gatos, H. C.

    1980-01-01

    The microdistribution of oxygen in Czochralskii-grown, p-type silicon crystals was determined by using the SEM in the EBIC mode in conjunction with spreading resistance measurements. When the conductivity remained p-type, bands of contrast were observed in the EBIC image which corresponded to maxima in resistivity. When at the oxygen concentration maxima the oxygen donor concentration exceeded the p-type dopant concentration, an inversion of the conductivity occurred. It resulted in the formation of p-n junctions in a striated configuration and the local inversion of the EBIC image contrast. By heat-treating silicon at 1000 C prior to the activation of oxygen donors, some silicon-oxygen micro-precipitates were observed in the EBIC image within the striated oxygen concentration maxima.

  11. Some distinctive features of zebrafish myogenesis based on unexpected distributions of the muscle cytoskeletal proteins actin, myosin, desmin, alpha-actinin, troponin and titin.

    PubMed

    Costa, Manoel L; Escaleira, Roberta C; Rodrigues, Viviane B; Manasfi, Muhamed; Mermelstein, Claudia S

    2002-08-01

    The current myofibrillogenesis model is based mostly on in vitro cell cultures and on avian and mammalian embryos in situ. We followed the expression of actin, myosin, desmin, alpha-actinin, titin, and troponin using immunofluorescence microscopy of zebrafish (Danio rerio) embryos. We could see young mononucleated myoblasts with sharp striations. The striations were positive for all the sarcomeric proteins. Desmin distribution during muscle maturation changes from dispersed aggregates to a perinuclear concentration to striated afterwards. We could not observe desmin-positive, myofibrillar-proteins-negative cells, and we could not find any non-striated distribution of sarcomeric proteins, such as stress fiber-like structures. Some steps, like fusion before striation, seem to be different in the zebrafish when compared with the previously described myogenesis sequences.

  12. Electron microscopy of the intestine of the African lungfish, Protopterus aethiopicus.

    PubMed

    Purkerson, M L; Jarvis, J U; Luse, S A; Dempsey, E W

    1975-05-01

    Electron microscopic observations are reported on the intestine of the African lungfish, Protopterus aethiopicus. The lungfish has a spiral valve rather than a true stomach. Segments of mucosa from this area reveal, by transmission microscopy, that most cells have distinct striated borders with parallel microvilli. Fibrils within the core of the microvilli extend deeply into the cytoplasm. Microvilli on the surface of goblet cells are less regularly arranged than those of absorptive cells. Interspersed among the cells with striated borders are cells, similar in cytologic appearance except that they are covered with tufts of kinetocilia. By transmission electron microscopy, abnormal cilia having one complete complement of microtubules plus incomplete sets from other cilia which share some of the peripheral doublets of the complete cilium are enclosed by a single membrane. Cilia are usual in the intestine of many lower forms but ordinarily absent in higher vertebrates. Their functional significance in this primitive fish is unknown. PMID:1155792

  13. Ankyrins and cellular targeting of diverse membrane proteins to physiological sites.

    PubMed

    Bennett, V; Chen, L

    2001-02-01

    Ankyrins are spectrin-binding proteins that associate via ANK repeats with a variety of ion channels/pumps, calcium release channels and cell adhesion molecules. Recent studies in mice indicate that ankyrins have a physiological role in restricting voltage-gated sodium channels and members of the L1 CAM family of cell adhesion molecules to excitable membranes in the central nervous system and in targeting calcium-release channels to the calcium homeostasis compartment of striated muscle.

  14. Mees' lines in a patient with multiple parasitic infections.

    PubMed

    Hepburn, M J; English, J C; Meffert, J J

    1997-06-01

    Mees' lines, or transverse striate leukonychia, are classically associated with arsenic poisoning, but have been described in other cases of acute or chronic illness. Their pathogenesis is thought to be a disruption of nail plate keratinization secondary to systemic stress. Mees' lines are observed in a patient with helminthic and amebic infections and no history of arsenic exposure. This case demonstrates another clinical setting in which Mees' lines can appear, providing further evidence that Mees' lines may chronicle systemic disease.

  15. Embryonal rhabdomyosarcoma: A rare oral tumor

    PubMed Central

    Datta, Sila; Ray, Jay Gopal; Deb, Tushar; Patsa, Santanu

    2016-01-01

    Rhabdomyosarcoma is the malignant neoplasm of striated muscle and a relatively uncommon tumor of the oral cavity. Embryonal variety is the most common subtype, observed in children below 10 years of age but occasionally seen in adolescents and young adults. The present report describes a case of embryonal rhabdomyosarcoma in the left posterior buccal mucosa, with extension in the adjacent alveolus, soft palate, oropharynx and nasopharynx of a 17-year-old female. PMID:27721622

  16. Mullerian adenosarcoma of the cervix with heterologous elements and sarcomatous overgrowth

    PubMed Central

    Pinto, Karen R.

    2016-01-01

    Cervical adenosarcomas are exceedingly infrequent tumors that occur most often in women of reproductive age. Adenosarcomas comprise benign epithelial elements and malignant stromal elements. The malignant stromal elements can either be homologous, such as fibroblasts or smooth muscle, or heterologous, like cartilage, striated muscle, or bone. We report a case of adenosarcoma of the cervix with heterologous elements and sarcomatous overgrowth in a 38-year-old woman. PMID:26722175

  17. [Polydermatomyositis in the adult and its management].

    PubMed

    Albert, J; Lamberti, A; Ott, H; Wauthier, D

    1983-02-24

    Polydermatomyositis is a chronic, non-suppurative disease of the striated muscle. In practice, the diagnostic criteria are often associated with other factors--alcoholism, corticotherapy--which, by themselves, may induce myopathy. In adults, the possible association of dermatomyositis with cancer rises the problem of scanning for neoplasia at regular intervals. In addition to corticotherapy, physical therapy helps the patient to maintain maximal autonomy.

  18. Muscle as a “Mediator“ of Systemic Metabolism

    PubMed Central

    Baskin, Kedryn K.; Winders, Benjamin R.; Olson, Eric N.

    2015-01-01

    Skeletal and cardiac muscles play key roles in the regulation of systemic energy homeostasis and display remarkable plasticity in their metabolic responses to caloric availability and physical activity. In this Perspective we discuss recent studies highlighting transcriptional mechanisms that govern systemic metabolism by striated muscles. We focus on the participation of the Mediator complex in this process, and suggest that tissue-specific regulation of Mediator subunits impacts metabolic homeostasis. PMID:25651178

  19. Incidental finding of a microsporidian parasite from an AIDS patient.

    PubMed Central

    McDougall, R J; Tandy, M W; Boreham, R E; Stenzel, D J; O'Donoghue, P J

    1993-01-01

    Light microscopic examination of feces from a human immunodeficiency virus-positive patient with chronic diarrhea, anorexia, and lethargy revealed the presence of numerous refractile bodies resembling microsporidian spores. They were subsequently identified as belonging to the genus Nosema on the basis of their ultrastructural characteristics. However, the microsporidia were enclosed within striated muscle cells, suggesting that they were probably ingested in food; thus, this represented an incidental finding rather than a true infection. Images PMID:8432833

  20. The occurrence of nymphal stage of Linguatula serrata in water buffaloes (Bubalus bubalis): nymphal morphometry and lymph node pathology.

    PubMed

    Sivakumar, P; Sankar, M; Nambi, P A; Praveena, P E; Singh, N

    2005-12-01

    The mesenteric lymph nodes (MLN) of buffaloes (n = 100) were examined for the presence of parasitic infection. The nymphal stage of Linguatula serrata was observed in two buffaloes. A single white-coloured nymph with transversely striated spines on a segmented body, two pairs of oral suckers and hooks was observed in the MLN. The morphometrics of the nymphs were studied. The affected lymph nodes were grossly enlarged with cyst and showed pathological lesions of fibroblastic reaction with a mild underlying inflammatory zone.

  1. Non-linearities in cortical simple cells and the possible detection of zero crossings.

    PubMed

    Richter, J; Ullman, S

    1986-01-01

    A theory of early visual information processing proposed by Marr and co-workers suggests that simple cortical cells may be involved in the detection of zero crossing in the retinal output. We have tested this theory by using pairs of adjacent edges (staircases stimuli) and recording from edge-specific simple cells in cat striate cortex. The zero crossing hypothesis gives rise for such stimuli to non-obvious predictions that were generally confirmed by the experiment.

  2. Improvement of Glucose Metabolism in the Visual Cortex Accompanies Visual Field Recovery in a Patient with Hemianopia.

    PubMed

    Suzuki, Yukihisa; Kiyosawa, Motohiro; Oda, Keiichi; Ishiwata, Kiich; Ishii, Kenji

    2016-01-01

    Damage to the visual cortex or the geniculostriatal pathways could cause homonymous visual field (VF) defects at the contralateral side of the lesion. In clinical practice, it is known that the VF defects are gradually recovered over months on the cases. We report a case with recovered homonymous hemianopia following an infarction in the visual cortex by positron emission tomography (PET) with (18)F-fluorodeoxyglucose (FDG) and (11)C-flumazenil (FMZ). A 58-year-old man experienced defect of left VF, and magnetic resonance imaging (MRI) revealed a localized infarction in the right occipital lobe. Goldmann VF perimetry revealed left homonymous hemianopia, but central VF was intact. Three months after the onset of infarction, we measured cerebral glucose metabolism with FDG and FMZ binding using PET. FMZ binding reflects the density of surviving neurons. Moreover, eight months after the onset, FDG-PET scan was performed. Goldmann VF perimetry was also performed at the same times of PET examinations. Decrease of cerebral glucose metabolism in the right anterior striate cortex was observed at three months after onset, while FMZ binding in the same area did not decrease in the patient. At eight months after onset, we observed recovery of VF and improvement of cerebral glucose metabolism in the anterior striate cortex. We presented change of cerebral glucose metabolism using PET accompanying improvement of VF. Evaluation of cerebral glucose metabolism and FMZ binding in the striate cortex is useful for estimating the prognosis of hemianopia caused by organic brain damage. PMID:27039943

  3. Mechanical Properties of Respiratory Muscles

    PubMed Central

    Sieck, Gary C.; Ferreira, Leonardo F.; Reid, Michael B.; Mantilla, Carlos B.

    2014-01-01

    Striated respiratory muscles are necessary for lung ventilation and to maintain the patency of the upper airway. The basic structural and functional properties of respiratory muscles are similar to those of other striated muscles (both skeletal and cardiac). The sarcomere is the fundamental organizational unit of striated muscles and sarcomeric proteins underlie the passive and active mechanical properties of muscle fibers. In this respect, the functional categorization of different fiber types provides a conceptual framework to understand the physiological properties of respiratory muscles. Within the sarcomere, the interaction between the thick and thin filaments at the level of cross-bridges provides the elementary unit of force generation and contraction. Key to an understanding of the unique functional differences across muscle fiber types are differences in cross-bridge recruitment and cycling that relate to the expression of different myosin heavy chain isoforms in the thick filament. The active mechanical properties of muscle fibers are characterized by the relationship between myoplasmic Ca2+ and cross-bridge recruitment, force generation and sarcomere length (also cross-bridge recruitment), external load and shortening velocity (cross-bridge cycling rate), and cross-bridge cycling rate and ATP consumption. Passive mechanical properties are also important reflecting viscoelastic elements within sarcomeres as well as the extracellular matrix. Conditions that affect respiratory muscle performance may have a range of underlying pathophysiological causes, but their manifestations will depend on their impact on these basic elemental structures. PMID:24265238

  4. Site differences of Toll-like receptor expression in the mucous epithelium of rat small intestine.

    PubMed

    Mantani, Y; Kamezaki, A; Udayanga, K G S; Takahara, E-i; Qi, W M; Kawano, J; Yokoyama, T; Hoshi, N; Kitagawa, H

    2011-10-01

    Toll-like receptors (TLRs) are known to recognize pathogen-associated molecular patterns and might function as receptors to detect microbes. In this study, the distribution of TLR-2, -4 and -9 were immunohistochemically investigated in the rat small intestine. As a result, TLR-2 was detected in the striated borders of villous columnar epithelial cells throughout the small intestine, except for the apices of a small number of intestinal villi. TLR-4 and -9 were detected in the striated borders of the villous columnar epithelial cells only in the duodenum. TLR-4-immunopositive minute granules were found in the apical cytoplasms of epithelial cells, subepithelial spaces and blood capillary lumina. TLR-2 and -4 were detected in the striated borders of undifferentiated epithelial cells and in the luminal substances of the intestinal crypts throughout the small intestine, but TLR-9 was not detected in the crypts throughout the small intestine. Only TLR-4 was detected in the secretory granules of Paneth cells in both the jejunal and ileal intestinal crypts. These findings suggest that duodenal TLRs might monitor indigenous bacteria proliferation in the upper alimentary tract, that TLR-2 might also monitor the proliferation of colonized indigenous bacteria throughout the small intestine, that the lack of TLR-2 at the villous apices might contribute to the settlement of indigenous bacteria, and that TLR-2 and -4 are secreted from intestinal crypts.

  5. Statistical-mechanical analysis of self-organization and pattern formation during the development of visual maps

    NASA Astrophysics Data System (ADS)

    Obermayer, K.; Blasdel, G. G.; Schulten, K.

    1992-05-01

    We report a detailed analytical and numerical model study of pattern formation during the development of visual maps, namely, the formation of topographic maps and orientation and ocular dominance columns in the striate cortex. Pattern formation is described by a stimulus-driven Markovian process, the self-organizing feature map. This algorithm generates topologically correct maps between a space of (visual) input signals and an array of formal ``neurons,'' which in our model represents the cortex. We define order parameters that are a function of the set of visual stimuli an animal perceives, and we demonstrate that the formation of orientation and ocular dominance columns is the result of a global instability of the retinoptic projection above a critical value of these order parameters. We characterize the spatial structure of the emerging patterns by power spectra, correlation functions, and Gabor transforms, and we compare model predictions with experimental data obtained from the striate cortex of the macaque monkey with optical imaging. Above the critical value of the order parameters the model predicts a lateral segregation of the striate cortex into (i) binocular regions with linear changes in orientation preference, where iso-orientation slabs run perpendicular to the ocular dominance bands, and (ii) monocular regions with low orientation specificity, which contain the singularities of the orientation map. Some of these predictions have already been verified by experiments.

  6. Giant secretory granules in the ducts of the parotid and submandibular glands of the slow loris.

    PubMed

    Tandler, B; Pinkstaff, C A; Nagato, T; Phillips, C J

    1996-06-01

    The parotid and submandibular glands of a slow loris, a rare Southeast Asian primate, were obtained after the head had been perfused by fixative for a study of the brain. These tissues were processed by conventional means for electron microscopy. Glands also were obtained at autopsy from 2 other lorises, fixed by immersion in formalin, and subjected to a battery of tests for glycoconjugates. In the parotid gland, a short segment of the proximal striated duct lacks both basal striations and any sign of secretory activity. The major portion of the striated duct consists of tall cells that contain a spectrum of secretory granules, some larger than the nuclei (many granules are > 9 mum in diameter). These granules, which are delimited by a single membrane, are capable of chain exocytosis. Many of the giant granules have bundles of cytofilaments (4.5-6.5 nm) in apparent association with their surface. Occasional cells contain numerous small granules. Duct cells with or without granules lack basal striations. The granules contain neutral glycoconjugates but no acidic glycoconjugates. Some, but not all, interlobular excretory ducts also have secretory granules that run the gamut from tiny to giant. Exactly the same situation occurs in the submandibular gland. Unlike other primates, which may have duct cells that contain only a few tiny granules in their apices, the cells in both the striated and excretory ducts in the slow loris appear to be specialized for secretion rather than for transport. The biofunction of the giant granules is unknown.

  7. Improvement of Glucose Metabolism in the Visual Cortex Accompanies Visual Field Recovery in a Patient with Hemianopia.

    PubMed

    Suzuki, Yukihisa; Kiyosawa, Motohiro; Oda, Keiichi; Ishiwata, Kiich; Ishii, Kenji

    2016-01-01

    Damage to the visual cortex or the geniculostriatal pathways could cause homonymous visual field (VF) defects at the contralateral side of the lesion. In clinical practice, it is known that the VF defects are gradually recovered over months on the cases. We report a case with recovered homonymous hemianopia following an infarction in the visual cortex by positron emission tomography (PET) with (18)F-fluorodeoxyglucose (FDG) and (11)C-flumazenil (FMZ). A 58-year-old man experienced defect of left VF, and magnetic resonance imaging (MRI) revealed a localized infarction in the right occipital lobe. Goldmann VF perimetry revealed left homonymous hemianopia, but central VF was intact. Three months after the onset of infarction, we measured cerebral glucose metabolism with FDG and FMZ binding using PET. FMZ binding reflects the density of surviving neurons. Moreover, eight months after the onset, FDG-PET scan was performed. Goldmann VF perimetry was also performed at the same times of PET examinations. Decrease of cerebral glucose metabolism in the right anterior striate cortex was observed at three months after onset, while FMZ binding in the same area did not decrease in the patient. At eight months after onset, we observed recovery of VF and improvement of cerebral glucose metabolism in the anterior striate cortex. We presented change of cerebral glucose metabolism using PET accompanying improvement of VF. Evaluation of cerebral glucose metabolism and FMZ binding in the striate cortex is useful for estimating the prognosis of hemianopia caused by organic brain damage.

  8. THE FINE STRUCTURE OF EPENDYMA IN THE BRAIN OF THE RAT

    PubMed Central

    Brightman, M. W.; Palay, S. L.

    1963-01-01

    The ciliated ependyma of the rat brain consists of a sheet of epithelial cells, the luminal surface of which is reflected over ciliary shafts and numerous evaginations of irregular dimensions. The relatively straight lateral portions of the plasmalemma of contiguous cells are fused at discrete sites to form five-layered junctions or zonulae occludentes which obliterate the intercellular space. These fusions occur usually at some distance below the free surface either independently or in continuity with a second intercellular junction, the zonula adhaerens. The luminal junction is usually formed by a zonula adhaerens or, occasionally, by a zonula occludens. The finely granular and filamentous cytoplasm contains supranuclear dense bodies, some of which are probably lysosomes and dense whorls of perinuclear filaments which send fascicles toward the lateral plasmalemma. The apical regions of the cytoplasm contain the basal body complexes of neighboring cilia. These complexes include a striated basal foot and short, non-striated rootlets emanating from the wall of each basal body. The rootlets end in a zone of granules about the proximal region of the basal body, adjacent to which may lie a striated mass of variable shape. All components of the basal body complex of adjacent cilia are independent of each other. PMID:14086765

  9. Chloral hydrate alters the organization of the ciliary basal apparatus and cell organelles in sea urchin embryos

    NASA Technical Reports Server (NTRS)

    Chakrabarti, A.; Schatten, H.; Mitchell, K. D.; Crosser, M.; Taylor, M.

    1998-01-01

    The mitotic inhibitor, chloral hydrate, induces ciliary loss in the early embryo phase of Lytechinus pictus. It causes a breakdown of cilia at the junction of the cilium and the basal body known as the basal plate. This leaves the plasma membrane temporarily unsealed. The basal apparatus accessory structures, consisting of the basal body, basal foot, basal foot cap, striated side arm, and striated rootlet, are either misaligned or disintegrated by treatment with chloral hydrate. Furthermore, microtubules which are associated with the basal apparatus are disassembled. Mitochondria accumulate at the base of cilia - underneath the plasma membrane - and show alterations in their structural organization. The accumulation of mitochondria is observed in 40% of all electron micrograph sections while 60% show the areas mostly devoid of mitochondria. The microvilli surrounding a cilium and striated rootlet remain intact in the presence of chloral hydrate. These results suggest that deciliation in early sea urchin embryos by chloral hydrate is caused by combined effects on the ciliary membrane and on microtubules in the cilia. Furthermore, it is suggested that chloral hydrate can serve as a tool to explore the cytoskeletal mechanisms that are involved in cilia motility in the developing sea urchin embryo.

  10. The cruciated microtubule-associated fibers of the green alga Dunaliella bioculata consist of a 31 kDa SF-assemblin.

    PubMed

    Lechtreck, K F; Frins, S; Bilski, J; Teltenkötter, A; Weber, K; Melkonian, M

    1996-04-01

    Cytoskeletons of Dunaliella bioculata, the biflagellate wallless green alga, were isolated and analyzed using a monoclonal and a polyclonal antibody raised against SF-assemblin, the major protein of the two striated microtubule-associated fibers of the alga Spermatozopsis similis. Indirect immunofluorescence showed antigenic structures associated with the four microtubular flagellar roots. SDS-PAGE followed by immunoblot analysis revealed a cross-reacting polypeptide of 31 kDa. This protein of D. bioculata was isolated using gel filtration chromatography in 8 M urea and in vitro reassembly of striated fibers. Microsequencing of the purified protein yielded various peptides, which could be aligned along the sequence of SF-assemblin from S. similis. A complete sequence of the Dunaliella protein was obtained by cDNA cloning. It documents the non helical head domain followed by a helical rod domain with a 29 residue repeat pattern based on four heptads followed by a skip residue. Compared to SF-assemblin of S. similis the SF-assemblin of Dunaliella has a shorter head and a slightly longer rod domain. The two algal SF-assemblins share only 57% sequence identity. We conclude that SF-assemblin and related proteins in various protists are representatives of a new class of alpha-helical proteins characterized by the ability to form a special segmented coiled coil and to assemble into striated fibers of 2 nm protofilaments in vivo and in vitro.

  11. Selective and superselective angiography of pediatric moyamoya disease angioarchitecture: the anterior circulation.

    PubMed

    Baltsavias, Gerasimos; Valavanis, Anton; Filipce, Venko; Khan, Nadia

    2014-01-01

    The angioarchitecture of the so-called moyamoya vessels in children has not been explicitly analyzed. We aimed to investigate the precise anatomy of the vascular anastomotic networks in patients with childhood moyamoya disease. Six children diagnosed with moyamoya disease for the first time underwent an angiographic investigation with selective and superselective injections. We recorded the arterial branches feeding the moyamoya anastomotic networks, their connections and the recipient vessels. Depending on the level of the steno-occlusive lesion, the feeding vessels included the medial striate arteries, the perforators of the choroidal segment of the carotid, the uncal artery, the medial and lateral branches of the intraventricular segment of the anterior choroidal artery, perforators of the communicating segment, the superior hypophyseal arteries, the prechiasmal branches of the ophthalmic artery, the ethmoidal arteries and the dural branches of the cavernous carotid. Through connections, which are described, the recipient vessels were the lateral striate arteries and the middle cerebral, the medial striate arteries and the anterior cerebral, medullary arteries around the ventricular system, anterior temporal branches of the middle cerebral, orbitofrontal and frontopolar branches of the anterior cerebral, as well as other cortical branches of the anterior and middle cerebral territories. The use of high quality selective and superselective angiography enabled us to clearly demonstrate for the first time aspects of the microangiographic anatomy of the moyamoya anastomotic network previously only vaguely or incompletely described.

  12. X-Tream: a novel dosimetry system for Synchrotron Microbeam Radiation Therapy

    NASA Astrophysics Data System (ADS)

    Petasecca, M.; Cullen, A.; Fuduli, I.; Espinoza, A.; Porumb, C.; Stanton, C.; Aldosari, A. H.; Bräuer-Krisch, E.; Requardt, H.; Bravin, A.; Perevertaylo, V.; Rosenfeld, A. B.; Lerch, M. L. F.

    2012-07-01

    Microbeam Radiation Therapy (MRT) is a radiation treatment technique under development for inoperable brain tumors. MRT is based on the use of a synchrotron generated X-ray beam with an extremely high dose rate ( ~ 20 kGy/sec), striated into an array of X-ray micro-blades. In order to advance to clinical trials, a real-time dosimeter with excellent spatial resolution must be developed for absolute dosimetry. The design of a real-time dosimeter for such a radiation scenario represents a significant challenge due to the high photon flux and vertically striated radiation field, leading to very steep lateral dose gradients. This article analyses the striated radiation field in the context of the requirements for temporal dosimetric measurements and presents the architecture of a new dosimetry system based on the use of silicon detectors and fast data acquisition electronic interface. The combined system demonstrates micrometer spatial resolution and microsecond real time readout with accurate sensitivity and linearity over five orders of magnitude of input signal. The system will therefore be suitable patient treatment plan verification and may also be expanded for in-vivo beam monitoring for patient safety during the treatment.

  13. Association of myostatin variants with growth traits of Zhikong scallop ( Chlamys farreri)

    NASA Astrophysics Data System (ADS)

    Fu, Qiang; Guo, Huihui; Feng, Liying; Li, Xue; Zhang, Lingling; Wang, Shi; Hu, Xiaoli; Bao, Zhenmin

    2016-02-01

    Scallop is a popular sea food and an important aquaculture shellfish. Identification of genes and genetic variants relating to scallop growth could benefit high-yielding scallop breeding. Myostatin ( MSTN) is a conservative regulator of muscle growth, and has become one of the most important target genes for genetic improvement of the production of farmed animals. In this study, four single nucleotide polymorphisms (SNPs) were identified in the 5' flanking region of MSTN gene ( CfMSTN) in Zhikong scallop ( Chlamys farreri). The association of these SNPs with scallop growth traits, including shell length, shell height, body weight and striated muscle weight was analyzed. The SNP g-1162Gstriated muscle weight. The TT type scallops showed significantly higher trait values than those of GT type, and the GG type individuals exhibited median values. On the contrary, significantly more CfMSTN transcripts were detected in the striated muscle of GT type scallops than in those of TT and GG type ones. Our results suggested that CfMSTN might regulate the scallop muscle growth negatively, and SNP g-1162G

  14. Cytoskeletal and cellular adhesion proteins in zebrafish (Danio rerio) myogenesis.

    PubMed

    Costa, M L; Escaleira, R; Manasfi, M; de Souza, L F; Mermelstein, C S

    2003-08-01

    The current myogenesis and myofibrillogenesis model has been based mostly on in vitro cell culture studies, and, to a lesser extent, on in situ studies in avian and mammalian embryos. While the more isolated artificial conditions of cells in culture permitted careful structural analysis, the actual in situ cellular structures have not been described in detail because the embryos are more difficult to section and manipulate. To overcome these difficulties, we used the optically clear and easy to handle embryos of the zebrafish Danio rerio. We monitored the expression of cytoskeletal and cell-adhesion proteins (actin, myosin, desmin, alpha-actinin, troponin, titin, vimentin and vinculin) using immunofluorescence microscopy and video-enhanced, background-subtracted, differential interference contrast of 24- to 48-h zebrafish embryos. In the mature myotome, the mononucleated myoblasts displayed periodic striations for all sarcomeric proteins tested. The changes in desmin distribution from aggregates to perinuclear and striated forms, although following the same sequence, occurred much faster than in other models. All desmin-positive cells were also positive for myofibrillar proteins and striated, in contrast to that which occurs in cell cultures. Vimentin appeared to be striated in mature cells, while it is developmentally down-regulated in vitro. The whole connective tissue septum between the somites was positive for adhesion proteins such as vinculin, instead of the isolated adhesion plaques observed in cell cultures. The differences in the myogenesis of zebrafish in situ and in cell culture in vitro suggest that some of the previously observed structures and protein distributions in cultures could be methodological artifacts.

  15. Towards a “canonical” agranular cortical microcircuit

    PubMed Central

    Beul, Sarah F.; Hilgetag, Claus C.

    2015-01-01

    Based on regularities in the intrinsic microcircuitry of cortical areas, variants of a “canonical” cortical microcircuit have been proposed and widely adopted, particularly in computational neuroscience and neuroinformatics. However, this circuit is founded on striate cortex, which manifests perhaps the most extreme instance of cortical organization, in terms of a very high density of cells in highly differentiated cortical layers. Most other cortical regions have a less well differentiated architecture, stretching in gradients from the very dense eulaminate primary cortical areas to the other extreme of dysgranular and agranular areas of low density and poor laminar differentiation. It is unlikely for the patterns of inter- and intra-laminar connections to be uniform in spite of strong variations of their structural substrate. This assumption is corroborated by reports of divergence in intrinsic circuitry across the cortex. Consequently, it remains an important goal to define local microcircuits for a variety of cortical types, in particular, agranular cortical regions. As a counterpoint to the striate microcircuit, which may be anchored in an exceptional cytoarchitecture, we here outline a tentative microcircuit for agranular cortex. The circuit is based on a synthesis of the available literature on the local microcircuitry in agranular cortical areas of the rodent brain, investigated by anatomical and electrophysiological approaches. A central observation of these investigations is a weakening of interlaminar inhibition as cortical cytoarchitecture becomes less distinctive. Thus, our study of agranular microcircuitry revealed deviations from the well-known “canonical” microcircuit established for striate cortex, suggesting variations in the intrinsic circuitry across the cortex that may be functionally relevant. PMID:25642171

  16. Histotopographical study of human periocular elastic fibers using aldehyde-fuchsin staining with special reference to the sleeve and pulley system for extraocular rectus muscles.

    PubMed

    Osanai, Hajime; Murakami, Gen; Ohtsuka, Aiji; Suzuki, Daisuke; Nakagawa, Takashi; Tatsumi, Haruyuki

    2009-09-01

    The aim of this study was to investigate the detailed configuration of periocular elastic fibers. Semiserial paraffin sections were made using 40 whole orbital contents from 27 elderly cadavers and stained by the aldehyde-fuchsin method. Periocular tissues were classified into three types according to directions of the elastic fibers, i.e., tissues containing anteroposteriorly running elastic fibers, those with mediolateral fibers, and those with meshwork of fibers. Anteroposterior elastic fiber-dominant tissue was seen in the upper eyelid and newly defined pulley plate for the medial and lateral recti (MR, LR). Mediolateral fibers were predominant in the central part of the inferior rectus pulley. In the pulley plates for the MR and LR, anteroposteriorly running fibers encased the striated muscle. Tenon's capsule and the epimysium of the recti were mediolateral fiber-dominant. However, at the entrance of the muscle terminal where Tenon's capsule reflects and continues to the epimysium, composite elastic fibers provided a meshwork-like skeleton. The elastic mesh was also seen around the lacrimal canaliculi. The pulley for the recti seemed to be composed of two parts--a connective tissue plate encasing the recti and specialized Tenon's capsule at an entrance or porta of the muscle. For both parts, elastic fibers were major functional components. The anteroposterior elastic fibers in the MR and LR pulley plates, especially, seemed to receive anteroposteriorly directed stress and tension from these striated muscles. The elastic interfaces seemed to prevent any concentration of stress that would interfere with periocular striated muscle functions, including hypothetical active pulleys.

  17. Dopamine, vesicular transporters, and dopamine receptor expression in rat major salivary glands.

    PubMed

    Tomassoni, Daniele; Traini, Enea; Mancini, Manuele; Bramanti, Vincenzo; Mahdi, Syed Sarosh; Amenta, Francesco

    2015-09-01

    The localization of dopamine stores and the expression and localization of dopamine (DAT) and vesicular monoamine transporters (VMAT) type-1 and -2 and of dopamine D1-like and D2-like receptor subtypes were investigated in rat submandibular, sublingual, and parotid salivary glands by HPLC with electrochemical detection, as well as immunochemical and immunohistochemical techniques. Male Wistar rats of 2 mo of age were used. The highest dopamine levels were measured in the parotid gland, followed by the submandibular and sublingual glands. Western blot analysis revealed DAT, VMAT-1, VMAT-2, and dopamine receptors immunoreactivity in membrane preparations obtained from the three glands investigated. Immunostaining for dopamine and transporters was developed within striated ducts. Salivary glands processed for dopamine receptors immunohistochemistry developed an immunoreaction primarily in striated and excretory ducts. In the submandibular gland, acinar cells displayed strong immunoreactivity for the D2 receptor, while cells of the convoluted granular tubules were negative for both D1-like and D2-like receptors. Parotid glands acinar cells displayed the highest immunoreactivity for both D1 and D2 receptors compared with other salivary glands. The above localization of dopamine and dopaminergic markers investigated did not correspond closely with neuron-specific enolase (NSE) localization. This indicates that at least in part, catecholamine stores and dopaminergic markers are independent from glandular innervation. These findings suggest that rat major salivary glands express a dopaminergic system probably involved in salivary secretion. The stronger immunoreactivity for dopamine transporters and receptors in striated duct cells suggests that the dopaminergic system could regulate not only quality, but also volume and ionic concentration of saliva.

  18. Preservative solution for skeletal muscle biopsy samples

    PubMed Central

    Kurt, Yasemin Gulcan; Kurt, Bulent; Ozcan, Omer; Topal, Turgut; Kilic, Abdullah; Muftuoglu, Tuba; Acikel, Cengizhan; Sener, Kenan; Sahiner, Fatih; Yigit, Nuri; Aydin, Ibrahim; Alay, Semih; Ekinci, Safak

    2015-01-01

    Context: Muscle biopsy samples must be frozen with liquid nitrogen immediately after excision and maintained at -80°C until analysis. Because of this requirement for tissue processing, patients with neuromuscular diseases often have to travel to centers with on-site muscle pathology laboratories for muscle biopsy sample excision to ensure that samples are properly preserved. Aim: Here, we developed a preservative solution and examined its protectiveness on striated muscle tissues for a minimum of the length of time that would be required to reach a specific muscle pathology laboratory. Materials and Methods: A preservative solution called Kurt-Ozcan (KO) solution was prepared. Eight healthy Sprague-Dawley rats were sacrificed; striated muscle tissue samples were collected and divided into six different groups. Muscle tissue samples were separated into groups for morphological, enzyme histochemical, molecular, and biochemical analysis. Statistical method used: Chi-square and Kruskal Wallis tests. Results: Samples kept in the KO and University of Wisconsin (UW) solutions exhibited very good morphological scores at 3, 6, and 18 hours, but artificial changes were observed at 24 hours. Similar findings were observed for the evaluated enzyme activities. There were no differences between the control group and the samples kept in the KO or UW solution at 3, 6, and 18 hours for morphological, enzyme histochemical, and biochemical features. The messenger ribonucleic acid (mRNA) of β-actin gene was protected up to 6 hours in the KO and UW solutions. Conclusion: The KO solution protects the morphological, enzyme histochemical, and biochemical features of striated muscle tissue of healthy rats for 18 hours and preserves the mRNA for 6 hours. PMID:26019417

  19. Electron Microscopy Study of Tin Whisker Growth

    SciTech Connect

    Norton, Murray G.; Lebret, Joel

    2003-03-30

    The growth of tin whiskers formed on sputtered tin layers deposited on brass was studied using electron microscopy. The occurrence of whiskers appeared to be largely independent of the macroscopic stress state in the film; rather it was microscopic compressive stresses arising from the formation of an intermetallic phase that appeared to be the necessary precursor. Whisker morphology was a result of whether nucleation had occurred on single grains or on multiple grains. In the latter case, the whiskers had a fluted or striated surface. The formation of whiskers on electron transparent samples was demonstrated. These samples showed the whiskers were monocrystalline and defect free, and that the growth direction could be determined.

  20. Recognizing, diagnosing, and treating rhabdomyolysis.

    PubMed

    Heard, Henry; Barker, James

    2016-05-01

    Rhabdomyolysis is an acute and potentially fatal syndrome characterized by striated muscle breakdown and subsequent release of muscle cell contents into the systemic circulation. The sudden release of large quantities of potassium, calcium, organic acids, and myoglobin into the bloodstream can cause renal tubal toxicity, cardiac dysrhythmias, and death. Complications can be managed and minimized if predicted and treated early, but patients may not have classic symptoms of rhabdomyolysis and may even be asymptomatic on presentation. This article reviews the pathophysiology, causes, diagnosis, and treatment of acute rhabdomyolysis.

  1. Beryllium-10 dating of the duration and retreat of the last pinedale glacial sequence.

    PubMed

    Gosse, J C; Klein, J; Lawn, B; Middleton, R; Evenson, E B

    1995-06-01

    Accurate terrestrial glacial chronologies are needed for comparison with the marine record to establish the dynamics of global climate change during transitions from glacial to interglacial regimes. Cosmogenic beryllium-10 measurements in the Wind River Range indicate that the last glacial maximum (marine oxygen isotope stage 2) was achieved there by 21,700 +/- 700 beryllium-10 years and lasted 5900 years. Ages of a sequence of recessional moraines and striated bedrock surfaces show that the initial deglaciation was rapid and that the entire glacial system retreated 33 kilometers to the cirque basin by 12,100 +/- 500 beryllium-10 years.

  2. A new structural interpretation relating NW Libya to the Hun Graben, western Sirt Basin based on a new paleostress inversion

    NASA Astrophysics Data System (ADS)

    Abdunaser, K. M.; McCaffrey, K. J. W.

    2015-12-01

    The present study is based on fault-slip data (striated fault planes with known sense of slip) measured in outcrops in two structural domains located along the Hun Graben, western Sirt Basin (150 fault-slip data) and the Jifarah Basin and Nafusah Uplift, northwest Libya (200 fault-slip data). Pre-existing field data collected in two previous studies were reprocessed using standard inversion methods in MyFaultTM(v. 1.03) stereonet software, produced by Pangaea Scientific Ltd.

  3. Perineal choristoma and atresia ani in 2 female Holstein Friesian calves.

    PubMed

    Binanti, D; Prati, I; Locatelli, V; Pravettoni, D; Sironi, G; Riccaboni, P

    2013-01-01

    Atresia ani, a congenital anomaly of the anus, can be associated with other types of malformation. Two female Holstein Friesian calves had imperforate anus, rectovaginal fistula, and perineal choristomas. In one case, the choristoma was composed of mature adipose and fibrous tissue with nephrogenic rests. In the other calf, the choristoma consisted of fragments of trabecular bone coated by cartilage and containing marrow, mixed with mature adipose and fibrous tissue, striated muscle fibers, nerves, and vessels. This combination of malformations resembles the association of anorectal malformations and perineal masses in children.

  4. Lutzomyia diamantinensis sp. nov., a new phlebotomine species (Diptera: Psychodidae) from a quartzite cave in Diamantina, state of Minas Gerais, Brazil.

    PubMed

    Barata, Ricardo Andrade; Serra e Meira, Paula Cavalcante Lamy; Carvalho, Gustavo Mayr de Lima

    2012-12-01

    A new species of Brazilian phlebotomine sandfly found in Brazil, municipality of Diamantina, state of Minas Gerais, is described based on males and females collected in a quartzite cave. The body of spermathecae is continuous to the individual duct, lanky and tapering at the end, with conical shaped, not striated and presenting the head with dense setae. The male presents gonostyle with four spines and a small subterminal seta and gonocoxite with one group of persistent setae. The paramere is simple with a group of small setae on the dorsal apex. The morphological features of this new species permit its inclusion in the migonei group.

  5. In Situ Sedimentological Evidence for Climate Change in Early Mars Provided by the Curiosity Rover in Gale Crater

    NASA Astrophysics Data System (ADS)

    Heydari, Ezat; Fairen, Alberto G.

    2016-10-01

    The Striated formation is one of the rock units that was deposited in Gale crater, Mars, during the Late Noachian to Hesperian time (4.2 to 3.6 billion years ago). It crops out for 3 km along the Curiosity's traverse. The Striated formation strikes N65○E and has a depositional dip of 10○ - 20○ to SE. It consists of 500 m to 1000 m of highly rhythmic layers each 1 m to 4 m in thickness. Study of MAHLI and MastCam images provided by the Curiosity Rover indicates that layers form fining-upward cycles consisting of thick-bedded to massive conglomerate at the base that grades upward to thinly bedded conglomerate, then to pebbly sandstone, and topped by laminated, fine grained sandstone. Layers show slump folds, soft sediment deformation, and cross-beddings.The highly rhythmic occurrence and the fining-upward grain size characteristic indicate that each layer within the Striated formation is a coarse-grained turbidite: a type of rock that forms when sediments move down-hill by gravity-driven turbidity flows and deposit in deep waters. We propose that turbidite layers of the Striated formation are related to delivery of sediments to Gale crater by megafloods through its northern rim. Upon entering Gale crater, sediments moved down-hill and deposited as turbidite layers when the crater may have been filled to the rim with water. About 1000 to 3000 turbidite layers are present suggesting the occurrences of as many megafloods during hothouse climatic intervals when Mars was warmer than the Present and had plenty of liquid water. Floods were generated by one or a combination of the following processes: (1) torrential rain along the margins of Mars's Northern Ocean, 500 km to 1000 km to the north, (2) rapid melting of ice in highland areas, and (3) tsunamis formed by impacts on the Northern Ocean. Cold and/or dry climate of icehouse intervals may have followed each warming episode. Mars's climate forcing mechanism and periodicities of climate change are not clear at this

  6. Cytomegalovirus in the parotid gland of a slow loris, Nyctecibus coucang.

    PubMed

    Tandler, B

    1997-07-01

    Sporadic enlarged cells with both nuclear and cytoplasmic viruses were found in the intralobular ducts of the parotid salivary gland of an adult female slow loris; these ducts are homologous to striated ducts in the salivary glands of other primates. The duct cell nuclei contained reticular inclusions and virions in all stages of development. Cytoplasmic virions were, in almost every case, confined to vacuoles; only a very few were free in the cytosol. The viruses conformed in ultrastructure to that of cytomegaloviruses described in other species. This may be the first observation by electron microscopy of in situ cytomegaloviruses in the salivary glands of a nonhuman primate.

  7. Beryllium-10 dating of the duration and retreat of the last pinedale glacial sequence.

    PubMed

    Gosse, J C; Klein, J; Lawn, B; Middleton, R; Evenson, E B

    1995-06-01

    Accurate terrestrial glacial chronologies are needed for comparison with the marine record to establish the dynamics of global climate change during transitions from glacial to interglacial regimes. Cosmogenic beryllium-10 measurements in the Wind River Range indicate that the last glacial maximum (marine oxygen isotope stage 2) was achieved there by 21,700 +/- 700 beryllium-10 years and lasted 5900 years. Ages of a sequence of recessional moraines and striated bedrock surfaces show that the initial deglaciation was rapid and that the entire glacial system retreated 33 kilometers to the cirque basin by 12,100 +/- 500 beryllium-10 years. PMID:17778979

  8. The length-tension curve in muscle depends on lattice spacing

    SciTech Connect

    Williams, C. D.; Salcedo, M. K.; Irving, T. C.; Regnier, M.; Daniel, T. L.

    2013-07-10

    Classic interpretations of the striated muscle length–tension curve focus on how force varies with overlap of thin (actin) and thick (myosin) filaments. New models of sarcomere geometry and experiments with skinned synchronous insect flight muscle suggest that changes in the radial distance between the actin and myosin filaments, the filament lattice spacing, are responsible for between 20% and 50% of the change in force seen between sarcomere lengths of 1.4 and 3.4 µm. Thus, lattice spacing is a significant force regulator, increasing the slope of muscle's force–length dependence.

  9. Sonographic appearance of angioedema in local allergic reactions to insect bites and stings.

    PubMed

    Tay, Ee Tein; Tsung, James W

    2014-09-01

    Soft tissue infections and angioedema from insect bites and stings may be difficult to differentiate by inspection. We present sonographic findings of 4 cases of soft tissue swelling from insect bites and stings suggestive of angioedema. Sonographic features of soft tissue angioedema consist of thickened subcutaneous tissue layers with multiple linear, horizontal, striated, and hypoechoic lines following the tissue planes between soft tissue layers. In addition to the history and physical examination, sonographic findings may assist in differentiating between local allergic reactions and cellulitis in patients with insect bites and stings. Further study is warranted for clinical application.

  10. Image-based assessment of microvascular function and structure in collagen XV- and XVIII-deficient mice

    PubMed Central

    Rygh, C B; Løkka, G; Heljasvaara, R; Taxt, T; Pavlin, T; Sormunen, R; Pihlajaniemi, T; Curry, F R; Tenstad, O; Reed, R K

    2014-01-01

    Collagen XV and XVIII are ubiquitous constituents of basement membranes. We aimed to study the physiological roles of these two components of the permeability barrier non-invasively in striated muscle in mice deficient in collagen XV or XVIII by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). Structural information was obtained with transmission electron microscopy (TEM). MR data were analysed by two different analysis methods to quantify tissue perfusion and microcirculatory exchange parameters to rule out data analysis method-dependent results. Control mice (C57BL/6J Ola/Hsd strain) or mice lacking either collagen XV (Col15a1−/−) or XVIII (Col18a1−/−) were included in the study. MR images were acquired using a preclinical system using gadodiamide (Gd-DTPA-BMA, molecular weight 0.58 kDa) as a tracer. Exchange capacity (permeability (P)–surface area (S) product relative to blood flow (FB)) was increased in test mice compared to controls, but the contributions from P, S, and FB were different in these two phenotypes. FB was significantly increased in Col18a1−/−, but slightly decreased in Col15a1−/−. PS was significantly increased only in Col18a1−/− even though P was increased in both phenotypes suggesting S might also be reduced in Col15a1−/− mice. Immunohistochemistry and electron microscopy demonstrated alterations in capillary density and morphology in both knockout mouse strains in comparison to the control mice. Both collagen XV and XVIII are important for maintaining normal capillary permeability in the striated muscle. DCE-MRI and the perfusion analyses successfully determined microvascular haemodynamic parameters of genetically modified mice and gave results consistent with more invasive methods. Key points Collagen XV and XVIII occur in muscle and connective tissue capillaries and are needed for maintaining a normal circulatory phenotype. Lack of collagen XV in mice leads to increased vascular permeability

  11. Alexia for Braille following bilateral occipital stroke in an early blind woman.

    PubMed

    Hamilton, R; Keenan, J P; Catala, M; Pascual-Leone, A

    2000-02-01

    Recent functional imaging and neurophysiologic studies indicate that the occipital cortex may play a role in Braille reading in congenitally and early blind subjects. We report on a woman blind from birth who sustained bilateral occipital damage following an ischemic stroke. Prior to the stroke, the patient was a proficient Braille reader. Following the stroke, she was no longer able to read Braille yet her somatosensory perception appeared otherwise to be unchanged. This case supports the emerging evidence for the recruitment of striate and prestriate cortex for Braille reading in early blind subjects.

  12. Stem cell therapy: a future treatment of stress urinary incontinence.

    PubMed

    Nikolavasky, Dmitriy; Stangel-Wójcikiewicz, Klaudia; Stec, Malgorzata; Chancellor, Michael B

    2011-01-01

    The main urinary continence mechanism in human is the striated muscle rhabdosphincter that forms a ring around the mid-urethra. Cellular therapy and the use of stem cells transplanted into the site of the rhabdosphincter in a setting of stress urinary incontinence (SUI) may augment sphincter regeneration. Implanted cells may also release trophic factors promoting muscle and nerve integration into this muscle. We review the use of cellular therapy for SUI and our experience with the development of muscle-derived stem cells.

  13. Beryllium-10 dating of the duration and retreat of the last pinedale glacial sequence

    SciTech Connect

    Gosse, J.C. |; Klein, J.; Evenson, E.B.

    1995-06-02

    Accurate terrestrial glacial chronologies are needed for comparison with the marine record to establish the dynamics of global climate change during transitions from glacial to interglacial regimes. Cosmogenic beryllium-10 measurements in the Wind River Range indicate that the last glacial maximum (marine oxygen isotope stage 2) was achieved there by 21,700 {+-} 700 beryllium-10 years and lasted 5900 years. Ages of a sequence of recessional moraines and striated bedrock surfaces show that the initial deglaciation was rapid and that the entire glacial system retreated 33 kilometers to the cirque basin by 12,100 {+-} 500 beryllium-10 years.

  14. Structural Phenotyping of Stem Cell-Derived Cardiomyocytes

    PubMed Central

    Pasqualini, Francesco Silvio; Sheehy, Sean Paul; Agarwal, Ashutosh; Aratyn-Schaus, Yvonne; Parker, Kevin Kit

    2015-01-01

    Summary Structural phenotyping based on classical image feature detection has been adopted to elucidate the molecular mechanisms behind genetically or pharmacologically induced changes in cell morphology. Here, we developed a set of 11 metrics to capture the increasing sarcomere organization that occurs intracellularly during striated muscle cell development. To test our metrics, we analyzed the localization of the contractile protein α-actinin in a variety of primary and stem-cell derived cardiomyocytes. Further, we combined these metrics with data mining algorithms to unbiasedly score the phenotypic maturity of human-induced pluripotent stem cell-derived cardiomyocytes. PMID:25733020

  15. Background issues for defensive interceptors

    SciTech Connect

    Canavan, G.H.

    1991-03-01

    Mean nuclear backgrounds are large, but are arguably amenable to frame-to-frame subtraction. Striated backgrounds on the sensors for defensive interceptors could, however, cause clutter leak-through, which could make detection and track difficult. Nominal motions and backgrounds give signal to clutter ratios too low to be useful. Clutter leakage due to line-of-sight drift can be reduced by stabilizing the line of sight around the background clutter itself. Current interceptors have detector arrays large enough for operation independent of nuclear backgrounds in their fields of view. 6 refs., 2 figs.

  16. Fine structure of the submandibular salivary gland of the venomous short-tailed shrew, Blarina brevicauda Say (Insectivora: Soricidae).

    PubMed

    Carson, K A; Rose, R K

    1993-01-01

    Adult male short-tailed shrews, Blarina brevicauda, (Insectivora: Soricidae) were trapped in Virginia and Pennsylvania, anesthetized, and perfused via the left ventricle of the heart with fixative. The submandibular glands were dissected free and prepared for transmission electron microscopy. The lobular, compound tubuloacinar glands had secretory endpieces consisting of seromucous acini and serous tubules connected to intercalated ducts, granular ducts, striated ducts, and excretory ducts. The general cytology of the submandibular gland of Blarina shared morphological characters with individuals in several other mammalian orders and yet differed in many ways from another Insectivore, the European hedgehog, Erinaceus europaeus. PMID:8398545

  17. Did Mozart have a chronic extradural haematoma?

    PubMed

    Puech, B; Puech, P F; Dhellemmes, P; Pellerin, P; Lepoutre, F; Tichy, G

    1989-11-01

    When Mozart died at the age of 36, was he suffering from the belated complications of a calcified extradural haematoma? This theory took shape during the identification process of the skull owned by the Mozarteum, when the print of calcified extradural haematoma was discovered on the left inner temporoparietal calvarial surface of the skull. This print looks like a rosette, with three distinct concentric areas. The first outer area is striated, the second middle one is granular and scattered with bony deposits, the third central one is marked with vascular grooves.

  18. Diagnostic imaging in internal medicine

    SciTech Connect

    Eisenberg, R.L.

    1985-01-01

    This book examines medical diagnostic techniques. Topics considered include biological considerations in the approach to clinical medicines; infectious diseases; disorders of the heart; disorders of the vascular system; disorders of the respiratory system; diseases of the kidneys and urinary tract; disorders of the alimentary tract; disorders of the hepatobiliary system and pancreas; disorders of the hematopoietic system; disorders of bone and bone mineralization; disorders of the joints, connective tissues, and striated muscles; disorders of the nervous system; miscellaneous disorders; and procedures in diagnostic imaging.

  19. Geology and geochemistry of the Macheng Algoma-type banded iron-formation, North China Craton: Constraints on mineralization events and genesis of high-grade iron ores

    NASA Astrophysics Data System (ADS)

    Wu, Huaying; Niu, Xianglong; Zhang, Lianchang; Pirajno, Franco; Luo, Huabao; Qin, Feng; Cui, Minli; Wang, Changle; Qi, Min

    2015-12-01

    The Macheng iron deposit is located in the eastern Hebei province of the North China Craton (NCC). It is hosted in Neoarchean metamorphic rocks of Baimiaozi formation in the Dantazi Group, consisting of biotite-leptynite, plagioclase-gneiss, plagioclase-amphibolite, migmatite, migmatitic granite and quartz schist. Geochemical analyses of the host biotite leptynite and plagioclase amphibolites show that their protoliths are both volcanics, inferred to be trachytic basalt and basaltic andesite, respectively. Based on the geochemical signature of the host rocks, together with geology of the iron deposit, it is inferred that the Macheng BIF is an Algoma-type iron exhalative formation, formed in an arc-related basin in the Neoarchean. Post-Archean Australian Shale (PAAS)-normalized rare earth elements (REEs) plus yttrium (Y) concentrations of different BIF ores with gneissic, striated and banded structure in the Macheng deposit, show similar patterns with depletions in light rare earth elements (LREEs) and middle rare earth elements (MREEs) relative to heavy rare earth elements (HREEs) and with apparently positive La, Y and Eu anomalies. Y/Ho ratios of the gneissic, striated and banded BIF ores vary from 37 to 56. These geochemical features of the BIF ores reveal their affinity with the sea water and the presence of a high-temperature hydrothermal component, indicating that both the seawater and high temperature hydrothermal fluids derived from alteration of oceanic basalts and komatiites may contribute to formation of the Macheng BIF. Geological, mineralogical and geochemical studies of the Macheng deposit recognized two kinds of high-grade iron ores. One is massive oxidized high-grade ore (Fe2O3T = 74.37-86.20 wt.%), mainly consisting of hematite with some magnetite, which shows geochemical characteristics of the gneissic, striated and banded BIF ores. The other type is magnetite high-grade ore, also massive and consisting of magnetite, with distinct characteristics

  20. [Venomous and poisonous animals. III. Elapidae snake envenomation].

    PubMed

    Chippaux, J P

    2007-02-01

    Envenomation by Elapidae snakes is less frequent than by Viperidae snakes but represents a true medical emergency due to rapid progression of cobra syndrome. Elapidae venom contains neurotoxins that paralyze striated muscles especially in the thoracic cavity. Respiratory paralysis can occur within a few hours and is preceded by neurological symptoms (local paresthesia and paresis progressing to the cranial nerves). When cobra envenomation is suspected, antivenom administration by the direct venous route must be undertaken as quickly as possible to stop the envenomation process. Artificial ventilation is necessary in case of dyspnea.

  1. Muscle assembly: a titanic achievement?

    PubMed

    Gregorio, C C; Granzier, H; Sorimachi, H; Labeit, S

    1999-02-01

    The formation of perfectly aligned myofibrils in striated muscle represents a dramatic example of supramolecular assembly in eukaryotic cells. Recently, considerable progress has been made in deciphering the roles that titin, the third most abundant protein in muscle, has in this process. An increasing number of sarcomeric proteins (ligands) are being identified that bind to specific titin domains. Titin may serve as a molecular blueprint for sarcomere assembly and turnover by specifying the precise position of its ligands within each half-sarcomere in addition to functioning as a molecular spring that maintains the structural integrity of the contracting myofibrils.

  2. A new geographic and host record for infectious pancreatic necrosis

    USGS Publications Warehouse

    Parisot, T.J.; Yasutake, W.T.; Bressler, V.

    1963-01-01

    The occurrence of infectious pancreatic necrosis in rainbow trout (Salmo gairdneri), brook trout (Salvelinus fontinalis), and cutthroat trout (Salmo clarki) has been experimentally authenticated for the first time in the western United States. The cutthroat trout represents a new host. Brook trout fin tissue culture inoculated with bacteria-free filtrate from the diseased fish tissue showed marked degenerative changes after 24 hours. Chinook salmon (Oncorhynchus tshawytscha), kokanee (O. nerka), and silver salmon (O. kisutch) were not susceptible to the virus when inoculated. Histologically, extensive pancreatic necrosis was observed in the original and experimental materials, but striated muscle hyalinization was detected only in the original material.

  3. Stratification of electron-hole plasma and blue electroluminescence near a static domain of GaAs

    SciTech Connect

    Kerner, B.S.; Osipov, V.V.; Romanko, M.T.; Sinkevich, V.F.

    1986-07-01

    Experiments have been carried out on n-GaAs films in which a static domain forms near the anode, while at the same time a Gunn domain forms and travels away from the cathode. The electron-hole plasma which is produced homogeneously by a traveling domain becomes striated near the static domain, where a highly inhomogeneous short-wave emission is observed. Included in this emission are bright blue points, 1-2 microns in size, spaced about 4 microns apart. 5 references.

  4. The length–tension curve in muscle depends on lattice spacing

    PubMed Central

    Williams, C. David; Salcedo, Mary K.; Irving, Thomas C.; Regnier, Michael; Daniel, Thomas L.

    2013-01-01

    Classic interpretations of the striated muscle length–tension curve focus on how force varies with overlap of thin (actin) and thick (myosin) filaments. New models of sarcomere geometry and experiments with skinned synchronous insect flight muscle suggest that changes in the radial distance between the actin and myosin filaments, the filament lattice spacing, are responsible for between 20% and 50% of the change in force seen between sarcomere lengths of 1.4 and 3.4 µm. Thus, lattice spacing is a significant force regulator, increasing the slope of muscle's force–length dependence. PMID:23843386

  5. EEG correlation and impulse activity of neuronal populations of individual structures of the cat brain during elaboration and reproduction of motor and alimentary reactions in instrumental conditioned reflexes.

    PubMed

    Vasilevskiĭ, N N; Katinas, V Ia; Popova, L A; Ur'iash, V V

    1976-01-01

    Stable changes in EEG and spike activity of neuronal populations in different brain formations were studied on models of instrumental conditioned reflexes: motor and motor alimentary. A depencence has been established of the EEG amplitude-frequency parameters in the motor and striate cortical zones and the hippocampus on definite changes of unit spike activity in these areas. Simultaneous recording of the EEG and the spike activity of neuronal populations helps to elucidate the neurophysiological nature of individual rhythms of bio-electrical activity. Learned animals exhibit a stable reproduction of the spatial-temporal EEG patterns and motor alimentary reactions when automatic presentation of reinforcement is changed over to an arbitrary one.

  6. Neural variant of fetal rhabdomyoma and naevoid basal cell carcinoma syndrome.

    PubMed

    Hardisson, D; Jimenez-Heffernan, J A; Nistal, M; Picazo, M L; Tovar, J A; Contreras, F

    1996-09-01

    A 15-year-old boy with the characteristic features of the naevoid basal cell carcinoma syndrome presented with a retroperitoneal mass. The tumour showed morphological features of a still ill-defined variant of fetal rhabdomyoma, characterized by well-differentiated nerve fibres admixed with immature striated muscle cells, similar to neuromuscular choristoma. Four cases of fetal rhabdomyoma and naevoid basal cell carcinoma syndrome have been previously reported. The behaviour of this tumour has been benign, although a complete excision was impossible due to its close relation with abdominal vascular trunks.

  7. Imaging of Retrochiasmal and Higher Cortical Visual Disorders.

    PubMed

    Tantiwongkosi, Bundhit; Salamon, Noriko

    2015-08-01

    Retrochiasmal visual pathways include optic tracts, lateral geniculate nuclei, optic radiations, and striate cortex (V1). Homonymous hemianopsia and field defect variants with relatively normal visual acuity suggest that the lesions involve retrochiasmal pathways. From V1, visual input is projected to higher visual association areas that are responsible for perception of objects, faces, colors, and orientation. Visual association areas are classified into ventral and dorsal pathways. Damage to the ventral stream results in visual object agnosia, prosopagnosia, and achromatopsia. Balint syndrome, visual inattention, and pure alexia are examples of dorsal stream disorders. Posterior cortical atrophy can involve ventral and dorsal streams, often preceding dementia. PMID:26208417

  8. Spontaneous sarcomere dynamics

    NASA Astrophysics Data System (ADS)

    Günther, Stefan; Kruse, Karsten

    2010-12-01

    Sarcomeres are the basic force generating units of striated muscles and consist of an interdigitating arrangement of actin and myosin filaments. While muscle contraction is usually triggered by neural signals, which eventually set myosin motors into motion, isolated sarcomeres can oscillate spontaneously between a contracted and a relaxed state. We analyze a model for sarcomere dynamics, which is based on a force-dependent detachment rate of myosin from actin. Our numerical bifurcation analysis of the spontaneous sarcomere dynamics reveals notably Hopf bifurcations, canard explosions, and gluing bifurcations. We discuss possible implications for experiments.

  9. Catalogue of the mite family Tydeidae (Acari: Prostigmata) with the world key to the species.

    PubMed

    Silva, Guilherme Liberato Da; Metzelthin, Maicon Henrique; Silva, Onilda Santos Da; Ferla, Noeli Juarez

    2016-01-01

    Members of the Tydeidae are cosmopolitan, soft-bodied, striated or reticulated mites that are reported to be mainly phytophages, mycophages, pollenophages, insect parasites or scavengers. This catalogue includes 328 species belonging to 30 genera, and their distributions and type habitat. Until now, Brachytydeus comprises the largest number of species with 200, followed by Tydeus, with 50 species, and Pretydeus and Pseudolorryia, with 12 species each. An updated list of the Tydeidae (Acari: Prostigmata), a world key to the species and data on the zoogeographical distribution of the species are presented. PMID:27395702

  10. Note: Effective measurement of retained I(c) in evaluating electromechanical properties of high temperature superconductor tapes by the voltage tap clipping technique.

    PubMed

    Dedicatoria, Marlon J; Bautista, Zhierwinjay; Shin, Hyung-Seop; Sim, Kideok

    2015-08-01

    In this note, the effectiveness of voltage tap clipping technique was assessed in evaluating the electromechanical properties of high temperature superconductor (HTS) tapes in the aspect of practical device applications. In the four-probe transport I(c) measurement, instead of directly soldering the voltage lead wires onto the HTS samples, they were tapped to the sample by either just clipping or soldering them to the clips. This technique facilitated the simultaneous and repeated retained I(c) measurement test for multiple samples. Finally, the critical double bending diameter of HTS tapes and the electrical properties of jointed and striated coated conductor tapes could be easily determined.

  11. [Application of ultrasonic investigation in estimation of morphofunctional state of muscles in patients with ischemic contracture of foot].

    PubMed

    Liabakh, A P; Vovchenko, H Ia

    2002-03-01

    Results of ultrasonic investigation of the shin and foot muscles were analyzed in 14 patients with an ischemic contracture of foot (ICF). All the patients were operated on, clinical significance of ICF ultrasonic semiotics was estimated. Structural changes were demonstrated by diffuse strengthening of echogeneicity, striateness loss, ischemized muscles thickness reduction, origination of hypoechogenic (of hydrophilic nature) portions in places of necrosis of muscular tissues. Hyperechogeneicity is caused by fibrosis of an ischemized muscles, which during isometric contraction somewhat thickened, their echogeneicity did not change.

  12. Formation and characterisation of neuromuscular junctions between hiPSC derived motoneurons and myotubes.

    PubMed

    Demestre, M; Orth, M; Föhr, K J; Achberger, K; Ludolph, A C; Liebau, S; Boeckers, T M

    2015-09-01

    Striated skeletal muscle cells from humans represent a valuable source for in vitro studies of the motoric system as well as for pathophysiological investigations in the clinical settings. Myoblasts can readily be grown from human muscle tissue. However, if muscle tissue is unavailable, myogenic cells can be generated from human induced pluripotent stem cells (hiPSCs) preferably without genetic engineering. Our study aimed to optimize the generation of hiPSCs derived myogenic cells by employing selection of CD34 positive cells and followed by distinct, stepwise culture conditions. Following the expansion of CD34 positive single cells under myogenic cell culture conditions, serum deprived myoblast-like cells finally fused and formed multinucleated striated myotubes that expressed a set of key markers for muscle differentiation. In addition, these myotubes contracted upon electrical stimulation, responded to acetylcholine (Ach) and were able to generate action potentials. Finally, we co-cultured motoneurons and myotubes generated from identical hiPSCs cell lines. We could observe the early aggregation of acetylcholine receptors in muscle cells of immature co-cultures. At later stages, we identified and characterised mature neuromuscular junctions (NMJs). In summary, we describe here the successful generation of an iPS cell derived functional cellular system consisting of two distinct communicating cells types. This in vitro co-culture system could therefore contribute to research on diseases in which the motoneurons and the NMJ are predominantly affected, such as in amyotrophic lateral sclerosis or spinal muscular atrophy. PMID:26255853

  13. Observations of grain-boundary sliding and surface topography in an 8090 Al alloy after uniaxial and biaxial superplastic deformation

    SciTech Connect

    Chen, T.R.; Huang, J.C.

    1999-01-01

    The surface topography of an 8090 aluminum alloy was studied after uniaxial or biaxial superplastic deformation, with particular reference to grain-boundary sliding (GBS) offsets, grain rotation angles, formation of striated bands (SBs) or fibers, cavity distribution, and cavity formation mechanisms. Additionally, the contribution of GBS or grain separation to the overall strain was evaluated. Striated bands were observed and are thought to be the newly exposed faces of the grains inclined to the specimen`s surface. They were formed by sliding of grains upward and downward relative to the specimen surface. Grooves and crests inside SBs were formed from the relative motion of grain-boundary defects. Fibers were observed and are thought to be the further development of the SBs resulting from the formation of elongated cavities and grain separation. More cavitation was found in equibiaxially strained regions than in other regions subjected to approximately equivalent levels of strain. About 50 pct of the total strain was contributed to GBS in the uniaxial tensile-loaded specimens, as compared to about 30 pct in the biaxial-strained specimens. The effects of grain separation, grain rotation, and secondary GBS may be the reasons for the reduction of the observed strain contribution from GBS in biaxially strained specimens.

  14. Molecular structural basis for polymorphism in Alzheimer's β-amyloid fibrils

    PubMed Central

    Paravastu, Anant K.; Leapman, Richard D.; Yau, Wai-Ming; Tycko, Robert

    2008-01-01

    We describe a full structural model for amyloid fibrils formed by the 40-residue β-amyloid peptide associated with Alzheimer's disease (Aβ1–40), based on numerous constraints from solid state NMR and electron microscopy. This model applies specifically to fibrils with a periodically twisted morphology, with twist period equal to 120 ± 20 nm (defined as the distance between apparent minima in fibril width in negatively stained transmission electron microscope images). The structure has threefold symmetry about the fibril growth axis, implied by mass-per-length data and the observation of a single set of 13C NMR signals. Comparison with a previously reported model for Aβ1–40 fibrils with a qualitatively different, striated ribbon morphology reveals the molecular basis for polymorphism. At the molecular level, the 2 Aβ1–40 fibril morphologies differ in overall symmetry (twofold vs. threefold), the conformation of non-β-strand segments, and certain quaternary contacts. Both morphologies contain in-register parallel β-sheets, constructed from nearly the same β-strand segments. Because twisted and striated ribbon morphologies are also observed for amyloid fibrils formed by other polypeptides, such as the amylin peptide associated with type 2 diabetes, these structural variations may have general implications. PMID:19015532

  15. The dislocation of medical dominance: making space for interprofessional care.

    PubMed

    Bleakley, Alan

    2013-09-01

    The historical transition of modern medicine from an autonomous profession to a team-based interprofessional practice can be described in terms of space rather than time, with "place" as the unit of analysis. Imagining modern medicine spatially was instigated by Foucault, who described medical dominance as a territorializing of both individual body spaces and public spaces--the former through the diagnostic medical gaze, the latter in a gaze of health surveillance. However, much has happened since Foucault's (1963) analysis. The diagnostic gaze has been dispersed to develop a collaborative gaze including patients and healthcare professionals; political interests have appropriated the public health gaze; and the medical profession is subject to democratic processes of accountability. Medicine has lost its territorial imperative as new "liquid" and "nomadic" work practices emerge, making space for interprofessional care. Such dislocation of medical dominance and its multiple relocations are poorly theorised. Deleuze and Guattari distinguish between "striated" and "smooth" spaces. Striated space is associated with hierarchies and boundaries, where smooth space includes boundary crossing and democratic collaboration. Smooth or liminal spaces in hospitals, such as corridors, can paradoxically act as catalysts for collaboration or assembly democracy, affording opportunities for improvised interprofessional encounters. Such encounters can act as an antidote to planned protocols or imperatives for interprofessional collaboration. PMID:23930686

  16. Leukotrienes as mediators in ischemia-reperfusion injury in a microcirculation model in the hamster.

    PubMed Central

    Lehr, H A; Guhlmann, A; Nolte, D; Keppler, D; Messmer, K

    1991-01-01

    Leukotriene (LT)B4 promotes leukocyte chemotaxis and adhesion to the endothelium of postcapillary venules. The cysteinyl leukotrienes, LTC4, LTD4, and LTE4, elicit macromolecular leakage from this vessel segment. Both leukocyte adhesion to the endothelium and macromolecular leakage from postcapillary venules hallmark the microcirculatory failure after ischemia-reperfusion, suggesting a role of leukotrienes as mediators of ischemia-reperfusion injury. Using the dorsal skinfold chamber model for intravital fluorescence microscopy of the microcirculation in striated muscle in awake hamsters and sequential RP-HPLC and RIA for leukotrienes, we demonstrate in this study that (a) the leukotrienes (LT)B4 and LTD4 elicit leukocyte/endothelium interaction and macromolecular leakage from postcapillary venules, respectively, that (b) leukotrienes accumulate in the tissue after ischemia and reperfusion, and that (c) selective inhibition of leukotriene biosynthesis (by MK-886) prevents both postischemic leukotriene accumulation and the microcirculatory changes after ischemia-reperfusion, while blocking of LTD4/E4 receptors (by MK-571) inhibits postischemic macromolecular leakage. These results demonstrate a key role of leukotrienes in ischemia-reperfusion injury in striated muscle in vivo. Images PMID:1645749

  17. Identification and localization of caldesmon in cardiac muscle.

    PubMed Central

    Scott-Woo, G C; Walsh, M P; Ikebe, M; Kargacin, G J

    1998-01-01

    Caldesmon has been detected in smooth muscle and in a number of non-muscle cells. It binds both actin and myosin and may act as a regulator of contraction or a structural element in smooth muscle. The presence of caldesmon in striated muscle has not been well established. To address this issue, polyclonal antibodies and a panel of monoclonal antibodies were raised against chicken gizzard smooth muscle caldesmon and used to demonstrate that caldesmon is present in adult cardiac muscle of a variety of mammalian species. Western-blot analysis revealed the presence of caldesmon in ventricular myocytes isolated from rat heart. The epitopes for the individual monoclonal antibodies were mapped to the caldesmon primary structure using chymotryptic and 2-nitro-5-thiocyanatobenzoic acid fragments. Bovine and rat cardiac caldesmons were recognized only by a subset of these monoclonal antibodies, indicating primary sequence differences from the chicken smooth muscle protein. Immunofluorescence labelling of isolated myocytes from rat, rabbit and guinea pig cardiac muscle revealed a striated pattern of fluorescence labelling. Dual labelling of caldesmon and myosin or caldesmon and alpha-actinin demonstrated that caldesmon was present at the centre of the I-band rather than in the A-band, as might have been expected from the myosin binding properties of the smooth muscle protein. These results suggest a structural role for caldesmon in cardiac muscle cells. PMID:9693116

  18. A Comparative Overview of the Flagellar Apparatus of Dinoflagellate, Perkinsids and Colpodellids

    PubMed Central

    Okamoto, Noriko; Keeling, Patrick J.

    2014-01-01

    Dinoflagellates are a member of the Alveolata, and elucidation of the early evolution of alveolates is important for our understanding of dinoflagellates, and vice versa. The ultrastructure of the flagellar apparatus has been described from several dinoflagellates in the last few decades, and the basic components appear to be well conserved. The typical dinoflagellate apparatus is composed of two basal bodies surrounded by striated collars attached to a connective fiber. The longitudinal basal body is connected to a longitudinal microtubular root (LMR; equivalent of R1) and single microtubular root (R2), whereas the transverse basal body is connected to a transverse microtubular root (TMR; R3) and transverse striated root (TSR) with a microtubule (R4). Some of these components, especially the connective fibers and collars, are dinoflagellate specific characteristics that make their flagellar apparatus relatively complex. We also compare these structures with the flagellar apparatus from a number of close relatives of dinoflagellates and their sister, the apicomplexans, including colpodellids, perkinsids, and Psammosa. Though the ultrastructural knowledge of these lineages is still relatively modest, it provides us with an interesting viewpoint of the character evolution of the flagellar apparatus among those lineages.

  19. Regulation of muscle contraction by Drebrin-like protein 1 probed by atomic force microscopy

    NASA Astrophysics Data System (ADS)

    Garces, Renata; Butkevich, Eugenia; Platen, Mitja; Schmidt, Christoph F.; Biophysics Team

    Sarcomeres are the fundamental contractile units of striated muscle cells. They are composed of a variety of structural and regulatory proteins functioning in a precisely orchestrated fashion to enable coordinated force generation in striated muscles. Recently, we have identified a C. elegans drebrin-like protein 1 (DBN-1) as a novel sarcomere component, which stabilizes actin filaments during muscle contraction. To further characterize the function of DBN-1 in muscle cells, we generated a new dbn-1 loss-of-function allele. Absence of DBN-1 resulted in a unique worm movement phenotype, characterized by hyper-bending. It is not clear yet if DBN-1 acts to enhance or reduce the capacity for contraction. We present here an experimental mechanical study on C. elegans muscle mechanics. We measured the stiffness of the worm by indenting living C. eleganswith a micron-sized sphere adhered to the cantilever of an atomic force microscope (AFM). Modeling the worm as a pressurized elastic shell allows us to monitor the axial tension in the muscle through the measured stiffness. We compared responses of wild-type and mutant C. elegans in which DBN-1 is not expressed..

  20. A new nodavirus is associated with covert mortality disease of shrimp.

    PubMed

    Zhang, Qingli; Liu, Qun; Liu, Shuang; Yang, Haolin; Liu, Sun; Zhu, Luoluo; Yang, Bing; Jin, Jiting; Ding, Lixue; Wang, Xiuhua; Liang, Yan; Wang, Qintao; Huang, Jie

    2014-12-01

    A new nodavirus, named covert mortality nodavirus (CMNV), is associated with covert mortality disease of shrimp which has caused serious loss in China since 2009. Histopathological examination of shrimp suffering the disease revealed coagulative necrosis of striated muscle similar to typical histopathology features of infectious myonecrosis virus (IMNV), Penaeus vannamei nodavirus (PvNV) and Macrobrachium rosenbergii nodavirus (MrNV). However, shrimp suffering this disease tested negative for IMNV, MrNV and PvNV by reverse transcription (RT)-PCR. Additionally, eosinophilic inclusions were found in epithelium of the tubules in the hepatopancreas and lymphoid organ, and mass karyopyknotic nuclei existed in the muscle and lymphoid organ. The tubular epithelium of the hepatopancreas showed significant atrophy. A cDNA library was constructed from total RNA of infected shrimp. Sequencing and alignment analysis showed that one clone with an 1185 bp insert (designated CMNV-7) shared 54, 53 and 39% identity with the amino acid sequences of RNA-dependent RNA polymerase from Flock House virus, black beetle virus and MrNV. The results of fluorescence in situ hybridization showed that the hepatopancreas, striated muscle and lymphoid organ were positively reacting tissues. The mean size of negative-stained virus particles was 32 nm. In addition, a nested RT-PCR assay was developed for CMNV, and the RT-PCR detection results revealed that Fenneropenaeus chinensis, Litopenaeus vannamei and Marsupenaeus japonicus suffering from this disease were CMNV-positive. PMID:25205685

  1. Compliance Accelerates Relaxation in Muscle by Allowing Myosin Heads to Move Relative to Actin.

    PubMed

    Campbell, Kenneth S

    2016-02-01

    The mechanisms that limit the speed at which striated muscles relax are poorly understood. This work presents, to our knowledge, novel simulations that show that the time course of relaxation is accelerated by interfilamentary movement resulting from series compliance; force drops faster when myosin heads move relative to actin during relaxation. This insight was obtained by using cross-bridge distribution techniques to simulate the mechanical behavior of half-sarcomeres that were connected in series with springs of varying stiffness. (The springs mimic the combined effects of half-sarcomere heterogeneity and muscle's series elastic component.) Half-sarcomeres that shortened by >∼10 nm when they were activated subsequently relaxed with a biphasic profile; force initially declined slowly and approximately linearly before collapsing with a fast exponential time course. Stretches imposed during the linear phase quickened relaxation, while shortening movements prolonged the time course. These predictions are consistent with data from experiments performed by many other groups using single muscle fibers and isolated myofibrils. When half-sarcomeres were linked to stiff springs (so that they did not shorten appreciably during the simulations), force relaxed with a slow exponential time course and did not show biphasic behavior. Together, these results suggest that fast relaxation of striated muscle is an emergent property that reflects multiscale interactions within the muscle architecture. The nonlinear behavior during relaxation reflects perturbations to the dynamic coupling of regulated binding sites and cycling myosin heads that are induced by interfilamentary movement.

  2. Background and stimulus-induced patterns of high metabolic activity in the visual cortex (area 17) of the squirrel and macaque monkey

    SciTech Connect

    Humphrey, A.L.; Hendrickson, A.E.

    1983-02-01

    The authors have used 2-deoxy-D-(/sup 14/C)glucose (2-DG) autoradiography and cytochrome oxidase histochemistry to examine background and stimulus-induced patterns of metabolic activity in monkey striate cortex. In squirrel monkeys (Saimiri sciureus) that binocularly or monocularly viewed diffuse white light or binocularly viewed bars of many orientations and spatial frequencies, 2-DG consumption was not uniform across the cortex but consisted of regularly spaced radial zones of high uptake. The cytochrome oxidase stain in these animals also revealed patches of high metabolism which coincided with the 2-DG patches. Squirrel monkeys binocularly viewing vertical stripes showed parallel bands of increased 2-DG uptake in the cortex, while the cytochrome label in these animals remained patchy. In macaque (Macaca nemestrina) monkeys, binocular stimulation with many orientations and spatial frequencies produced radial zones of high 2-DG uptake. When viewed tangentially, these zones formed a dots-in-rows pattern with a spacing of 350 X 500 microns; cytochrome oxidase staining produced an identical pattern. Macaca differed from Saimiri in that monocular stimulation labeled alternate rows. These results indicate that there are radial zones of high background metabolism across squirrel and macaque monkey striate cortex. In Saimiri these zones do not appear to be related to an eye dominance system, while in Macaca they do. The presence of these zones of high metabolism may complicate the interpretation of 2-DG autoradiographs that result from specific visual stimuli.

  3. The iojap gene in maize

    SciTech Connect

    Martienssen, Robert

    2001-12-01

    The classical maize mutant iojap (Iodent japonica) has variegated green and white leaves. Green sectors have cells with normal chloroplasts whereas white sectors have cells where plastids fail to differentiate. These mutant plastids, when transmitted through the female gametophyte, do not recover in the presence of wild type Iojap. We cloned the Ij locus, and we have investigated the mechanism of epigenetic inheritance and phenotypic expression. More recently, a modifier of this type of variegation, ''Inhibitor of striate'', has also been cloned. Both the iojap and inhibitor of striate proteins have homologs in bacteria and are members of ancient conserved families found in multiple species. These tools can be used to address fundamental questions of inheritance and variegation associated with this classical conundrum of maize genetics. Since the work of Rhoades there has been considerable speculation concerning the nature of the Iojap gene product, the origin of leaf variegation and the mechanism behind the material inheritance of defective plastids. This has made Iojap a textbook paradigm for cytoplasmic inheritance and nuclear-organellar interaction for almost 50 years. Cloning of the Iojap gene in maize, and homologs in other plants and bacteria, provides a new means to address the origin of heteroplastidity, variegation and cytoplasmic inheritance in higher plants.

  4. Does shape discrimination by the mouth activate the parietal and occipital lobes? - near-infrared spectroscopy study.

    PubMed

    Kagawa, Tomonori; Narita, Noriyuki; Iwaki, Sunao; Kawasaki, Shingo; Kamiya, Kazunobu; Minakuchi, Shunsuke

    2014-01-01

    A cross-modal association between somatosensory tactile sensation and parietal and occipital activities during Braille reading was initially discovered in tests with blind subjects, with sighted and blindfolded healthy subjects used as controls. However, the neural background of oral stereognosis remains unclear. In the present study, we investigated whether the parietal and occipital cortices are activated during shape discrimination by the mouth using functional near-infrared spectroscopy (fNIRS). Following presentation of the test piece shape, a sham discrimination trial without the test pieces induced posterior parietal lobe (BA7), extrastriate cortex (BA18, BA19), and striate cortex (BA17) activation as compared with the rest session, while shape discrimination of the test pieces markedly activated those areas as compared with the rest session. Furthermore, shape discrimination of the test pieces specifically activated the posterior parietal cortex (precuneus/BA7), extrastriate cortex (BA18, 19), and striate cortex (BA17), as compared with sham sessions without a test piece. We concluded that oral tactile sensation is recognized through tactile/visual cross-modal substrates in the parietal and occipital cortices during shape discrimination by the mouth.

  5. Anal sphincter injuries during hemorrhoidectomy: a multi center study.

    PubMed

    Mirzaei, Rezvan; Mahjoubi, Bahar; Kadivar, Maryam; Azizi, Rasoul; Zahedi-Shoolami, Leila

    2012-01-01

    Hemorrhoidectomy is the treatment of choice for patients with third or fourth-degree hemorrhoids. Although the majority of surgeons believe that surgical hemorrhoidectomy is the most effective approach with excellent results in the management of hemorrhoid disease, but hemorrhoidectomy is not a simple procedure. One of the complications of this surgery is an injury to anal sphincters that can lead to incontinency in some patients. In this study, we aimed to reveal the percentage of external and internal anal sphincter injuries in surgical hemorrhoidectomy. We prospectively enrolled 128 patients from April 2006 to February 2007. They underwent hemorrhoidectomy in three general hospitals in Tehran. All patients were in grade III or IV and underwent open hemorrhoidectomy (Milligan-Morgan). After surgery, all resected material was histopathologically examined by two expert pathologists and the results confirmed by other one if there is any discrepancy. From all specimens which sent to the pathology department 15.8% (21 Pts.) had muscle fibers that Smooth muscle fibers were seen in 80.5% (17 Pts.) of them and striated muscle fibers were found in 19.5% (4 Pts.). Although hemorrhoidectomy is a safe and effective method for treatment of hemorrhoid, but the inadvertent removal of smooth and striated muscle during open hemorrhoidectomy had raised concerns about its effects on postoperative anorectal function.

  6. Palaeozoic nonmarine firmground ichnofaunas: evidence from the permian of the Paganzo basin

    USGS Publications Warehouse

    Buatois, L.A.; Mangano, M.G.; Acenolaza, F.G.

    1996-01-01

    Meniscate striated traces are recorded from Permian fluvial deposits of the La Colina Formation (Paganzo Group) at Los Colorados de Patqui??a (La Rioja Province). These structures are characterized by their remarkable well developed striations, oblique to the margins of unbranched and unwalled traces. Taxonomic assessment of these structures must await clarification of the actual nature of the ichnogenus Scoyenia and its relationship with Taenidium. They are interpreted as arthropod feeding structures (fodinichnia). Meniscate striated traces characterize firm substrates and crosscut a softground ichnofauna ascribed to the Scoyenia ichnofacies. Trace makers probably colonized the desiccated margins of a floodplain water body. A review of the ichnologic record of nonmarine firmgrounds shows the widespread establishment of trace fossils in cohesive sediments during the Mesozoic and only an incipient development during the Palaeozoic. The Palaeozoic examples undoubtely ascribed to invertebrates are known from the Permian and seem to record the displacement of organisms in the interface of a firm substrate, rather than burrowing activities within the cohesive sediment.

  7. Audiovisual Association Learning in the Absence of Primary Visual Cortex.

    PubMed

    Seirafi, Mehrdad; De Weerd, Peter; Pegna, Alan J; de Gelder, Beatrice

    2015-01-01

    Learning audiovisual associations is mediated by the primary cortical areas; however, recent animal studies suggest that such learning can take place even in the absence of the primary visual cortex. Other studies have demonstrated the involvement of extra-geniculate pathways and especially the superior colliculus (SC) in audiovisual association learning. Here, we investigated such learning in a rare human patient with complete loss of the bilateral striate cortex. We carried out an implicit audiovisual association learning task with two different colors of red and purple (the latter color known to minimally activate the extra-genicular pathway). Interestingly, the patient learned the association between an auditory cue and a visual stimulus only when the unseen visual stimulus was red, but not when it was purple. The current study presents the first evidence showing the possibility of audiovisual association learning in humans with lesioned striate cortex. Furthermore, in line with animal studies, it supports an important role for the SC in audiovisual associative learning.

  8. A Comparative Overview of the Flagellar Apparatus of Dinoflagellate, Perkinsids and Colpodellids

    PubMed Central

    Okamoto, Noriko; Keeling, Patrick J.

    2014-01-01

    Dinoflagellates are a member of the Alveolata, and elucidation of the early evolution of alveolates is important for our understanding of dinoflagellates, and vice versa. The ultrastructure of the flagellar apparatus has been described from several dinoflagellates in the last few decades, and the basic components appear to be well conserved. The typical dinoflagellate apparatus is composed of two basal bodies surrounded by striated collars attached to a connective fiber. The longitudinal basal body is connected to a longitudinal microtubular root (LMR; equivalent of R1) and single microtubular root (R2), whereas the transverse basal body is connected to a transverse microtubular root (TMR; R3) and transverse striated root (TSR) with a microtubule (R4). Some of these components, especially the connective fibers and collars, are dinoflagellate specific characteristics that make their flagellar apparatus relatively complex. We also compare these structures with the flagellar apparatus from a number of close relatives of dinoflagellates and their sister, the apicomplexans, including colpodellids, perkinsids, and Psammosa. Though the ultrastructural knowledge of these lineages is still relatively modest, it provides us with an interesting viewpoint of the character evolution of the flagellar apparatus among those lineages. PMID:27694777

  9. Unusual case of traumatic neuroma of the orbit.

    PubMed

    Ulivieri, Simone; Muscas, Giovanni; Miracco, Clelia; Oliveri, Giuseppe; Galluzzi, Paolo; Giorgio, Antonio

    2016-01-01

    Traumatic or amputation neuromas are neoformations developing after damage to a peripheral nerve. They are not proper tumors but rather a reactive process or a frustrated attempt of nerve regeneration. Traumatic neuromas are potentially found in every sensory peripheral nerve and often at the site of past surgical intervention, including orbital surgery. A 29-year-old Northern African migrant presented progressive exophthalmos and progressive loss of acuity in left eye, which had started about 6 months before after a cranio-facial trauma caused by a violent assault. MRI of the orbits showed a massive intra-orbital, intra-conical lesion, clearly compressing and dislocating the optic nerve and extending posteriorly to the orbital apex. Surgery was performed through lateral approach of Kroenlein and led to complete excision of the lesion. Histology revealed fibrotic, adipose and striated muscle tissues, a disordered, non-neoplastic overgrowth of small and large fascicles of nerves, inflammatory infiltrates, and fibrosis with sparse calcifications were diffusely observed in a background of fat, scar and striated muscle tissued. Patient was discharged on the fifth day in good health condition, without deficit of eye motion but without recovery of visual acuity. In conclusion, this case demonstrates that traumatic neuromas may arise in the orbit in patients with minor direct trauma to nerves and without previous surgical treatment.

  10. Objective analysis of toolmarks in forensics

    SciTech Connect

    Grieve, Taylor N.

    2013-01-01

    Since the 1993 court case of Daubert v. Merrell Dow Pharmaceuticals, Inc. the subjective nature of toolmark comparison has been questioned by attorneys and law enforcement agencies alike. This has led to an increased drive to establish objective comparison techniques with known error rates, much like those that DNA analysis is able to provide. This push has created research in which the 3-D surface profile of two different marks are characterized and the marks’ cross-sections are run through a comparative statistical algorithm to acquire a value that is intended to indicate the likelihood of a match between the marks. The aforementioned algorithm has been developed and extensively tested through comparison of evenly striated marks made by screwdrivers. However, this algorithm has yet to be applied to quasi-striated marks such as those made by the shear edge of slip-joint pliers. The results of this algorithm’s application to the surface of copper wire will be presented. Objective mark comparison also extends to comparison of toolmarks made by firearms. In an effort to create objective comparisons, microstamping of firing pins and breech faces has been introduced. This process involves placing unique alphanumeric identifiers surrounded by a radial code on the surface of firing pins, which transfer to the cartridge’s primer upon firing. Three different guns equipped with microstamped firing pins were used to fire 3000 cartridges. These cartridges are evaluated based on the clarity of their alphanumeric transfers and the clarity of the radial code surrounding the alphanumerics.

  11. Quantification of neurological and other contributors to continence in female rats

    PubMed Central

    Jiang, Hai-Hong; Salcedo, Levilester B.; Damaser, Margot S.

    2011-01-01

    Smooth muscle, striated muscle, their central and peripheral innervations and control, and mucosal coaptation contribute to maintenance of continence. We used manual leak point pressure (mLPP) testing and electrical stimulation LPP (eLPP) testing in female rats to quantify the contribution of these factors to urethral resistance, a measure of continence. Abdominal muscles were electrically stimulated to induce leakage for eLPP. A Crede maneuver was applied for mLPP. These were repeated after complete T8 spinal cord injury (SCI) and/or bilateral pudendal nerve transection (PNT). After euthanasia, mLPP was repeated. MLPP was not significantly affected by opening the abdomen, suggesting that intra-abdominal pressure transmission contributes little to continence during slow pressure changes. ELPP was significantly higher than mLPP in intact rats, after PNT, and after SCI+PNT, suggesting that abdominal pressure transmission contributes to continence during rapid increases in intra-abdominal pressure. MLPP decreased significantly after PNT, indicating that urethral striated muscles contribute significantly to continence. ELPP decreased significantly after PNT with and without SCI, suggesting that supraspinal control significantly affects continence during rapid pressure changes, but not during slow pressure changes. MLPP after euthanasia was significantly decreased compared to mLPP after SCI+PNT, suggesting that urethral mucosal seal coaptation and tissue elasticity also contribute to continence. The urethra is a complex organ that maintains continence via a highly organized and hierarchical system involving both the central and peripheral nervous systems. PMID:21295013

  12. Developmental analysis of tropomyosin gene expression in embryonic stem cells and mouse embryos.

    PubMed Central

    Muthuchamy, M; Pajak, L; Howles, P; Doetschman, T; Wieczorek, D F

    1993-01-01

    Tropomyosins (TMs) comprise a family of actin-binding proteins which play an important role in the regulation of contractility in muscle (cardiac, skeletal, and smooth) and nonmuscle cells. Although they are present in all cells, different isoforms are characteristic of specific cell types. In vertebrates, there are four different TM genes (alpha-TM, beta-TM, TM30, and TM4), three of which generate alternatively spliced isoforms. This study defines the expression patterns of these isoforms during murine embryogenesis, using both in vivo and in vitro conditions. The embryonic stem cell culture system, which has been shown to mimic different stages of mouse embryonic development, including the differentiation of primitive organ systems such as the myocardium, is used for our in vitro analysis. Our results demonstrate that several TM isoforms are expressed in specific developmental patterns, often correlated with the differentiation of particular tissues or organs. Surprisingly, other TMs, such as the striated muscle beta-TM and smooth muscle alpha-TM, are expressed constitutively. This study also demonstrates that there is an excellent correlation between the expression patterns of the TM isoforms observed in developing embryonic stem cells and mouse embryos. In addition, a quantitative molecular analysis of TM isoforms was conducted in embryonic, neonatal, and adult cardiac tissue. Our results show for the first time that the alpha- and beta-TM striated muscle transcripts are present in the earliest functional stages of the heart, and these TM isoforms are identical to those present throughout cardiac development. Images PMID:7684495

  13. The fibrillar collagen family.

    PubMed

    Exposito, Jean-Yves; Valcourt, Ulrich; Cluzel, Caroline; Lethias, Claire

    2010-01-01

    Collagens, or more precisely collagen-based extracellular matrices, are often considered as a metazoan hallmark. Among the collagens, fibrillar collagens are present from sponges to humans, and are involved in the formation of the well-known striated fibrils. In this review we discuss the different steps in the evolution of this protein family, from the formation of an ancestral fibrillar collagen gene to the formation of different clades. Genomic data from the choanoflagellate (sister group of Metazoa) Monosiga brevicollis, and from diploblast animals, have suggested that the formation of an ancestral alpha chain occurred before the metazoan radiation. Phylogenetic studies have suggested an early emergence of the three clades that were first described in mammals. Hence the duplication events leading to the formation of the A, B and C clades occurred before the eumetazoan radiation. Another important event has been the two rounds of "whole genome duplication" leading to the amplification of fibrillar collagen gene numbers, and the importance of this diversification in developmental processes. We will also discuss some other aspects of fibrillar collagen evolution such as the development of the molecular mechanisms involved in the formation of procollagen molecules and of striated fibrils. PMID:20386646

  14. Sarcomeric Pattern Formation by Actin Cluster Coalescence

    PubMed Central

    Friedrich, Benjamin M.; Fischer-Friedrich, Elisabeth; Gov, Nir S.; Safran, Samuel A.

    2012-01-01

    Contractile function of striated muscle cells depends crucially on the almost crystalline order of actin and myosin filaments in myofibrils, but the physical mechanisms that lead to myofibril assembly remains ill-defined. Passive diffusive sorting of actin filaments into sarcomeric order is kinetically impossible, suggesting a pivotal role of active processes in sarcomeric pattern formation. Using a one-dimensional computational model of an initially unstriated actin bundle, we show that actin filament treadmilling in the presence of processive plus-end crosslinking provides a simple and robust mechanism for the polarity sorting of actin filaments as well as for the correct localization of myosin filaments. We propose that the coalescence of crosslinked actin clusters could be key for sarcomeric pattern formation. In our simulations, sarcomere spacing is set by filament length prompting tight length control already at early stages of pattern formation. The proposed mechanism could be generic and apply both to premyofibrils and nascent myofibrils in developing muscle cells as well as possibly to striated stress-fibers in non-muscle cells. PMID:22685394

  15. Titin stiffness modifies the force-generating region of muscle sarcomeres

    PubMed Central

    Li, Yong; Lang, Patrick; Linke, Wolfgang A.

    2016-01-01

    The contractile units of striated muscle, the sarcomeres, comprise the thick (myosin) and thin (actin) filaments mediating active contraction and the titin filaments determining “passive” elasticity. We hypothesized that titin may be more active in muscle contraction by directly modulating thick-filament properties. We used single-myofibril mechanical measurements and atomic force microscopy of individual sarcomeres to quantify the effects of sarcomere strain and titin spring length on both the inter-filament lattice spacing and the lateral stiffness of the actin-myosin overlap zone (A-band). We found that strain reduced the lattice spacing similarly in sarcomeres with stiff (rabbit psoas) or compliant titin (rabbit diaphragm), but increased A-band lateral stiffness much more in psoas than in diaphragm. The strain-induced alterations in A-band stiffness that occur independently of lattice spacing effects may be due to titin stiffness-sensing by A-band proteins. This mechanosensitivity could play a role in the physiologically important phenomenon of length-dependent activation of striated muscle. PMID:27079135

  16. Investigation of the electrophysiological correlates of negative BOLD response during intermittent photic stimulation: An EEG-fMRI study.

    PubMed

    Maggioni, Eleonora; Zucca, Claudio; Reni, Gianluigi; Cerutti, Sergio; Triulzi, Fabio M; Bianchi, Anna M; Arrigoni, Filippo

    2016-06-01

    Although the occurrence of concomitant positive BOLD responses (PBRs) and negative BOLD responses (NBRs) to visual stimuli is increasingly investigated in neuroscience, it still lacks a definite explanation. Multimodal imaging represents a powerful tool to study the determinants of negative BOLD responses: the integration of functional Magnetic Resonance Imaging (fMRI) and electroencephalographic (EEG) recordings is especially useful, since it can give information on the neurovascular coupling underlying this complex phenomenon. In the present study, the brain response to intermittent photic stimulation (IPS) was investigated in a group of healthy subjects using simultaneous EEG-fMRI, with the main objective to study the electrophysiological mechanisms associated with the intense NBRs elicited by IPS in extra-striate visual cortex. The EEG analysis showed that IPS induced a desynchronization of the basal rhythm, followed by the instauration of a novel rhythm driven by the visual stimulation. The most interesting results emerged from the EEG-informed fMRI analysis, which suggested a relationship between the neuronal rhythms at 10 and 12 Hz and the BOLD dynamics in extra-striate visual cortex. These findings support the hypothesis that NBRs to visual stimuli may be neuronal in origin rather than reflecting pure vascular phenomena. Hum Brain Mapp 37:2247-2262, 2016. © 2016 Wiley Periodicals, Inc.

  17. Ionic requirements for arterial action potential

    PubMed Central

    Keatinge, W. R.

    1968-01-01

    1. Strips of smooth muscle from common carotid arteries of sheep were electrically quiescent in solution containing Na 148 mM and Ca 2·5 mM. 2. When Ca was removed they became electrically active. Addition of low concentrations of Ca (0·025-0·075 mM) or Mg (0·025-0·750 mM) stopped their activity while ethylenediamine tetra-acetate (EDTA) (1·25 mM) accelerated it. 3. Replacement of Na by Tris or choline stopped the activity in Ca-free solution. After partial replacement of Na electrical activity could be restored by lowering the resting potential but after complete replacement of Na it could not. 4. In the presence of Ca (2·5 mM) small spikes could sometimes be induced after 20 min in Na-free Tris solution by lowering the resting potential by an increase in the external K concentration. 5. The results indicate that the depolarizing current of action potentials in this smooth muscle was largely carried by Na, although a little may have been carried by Ca in Ca-containing solutions. 6. The arteries in general resembled striated muscle rather than intestinal smooth muscle in these respects, but unlike striated muscle their action potentials were not stopped by tetrodotoxin. ImagesFig. 2 PMID:5639765

  18. Melting and cataclastic features in shatter cones in basalt from the Vista Alegre impact structure, Brazil

    NASA Astrophysics Data System (ADS)

    Pittarello, Lidia; Nestola, Fabrizio; Viti, Cecilia; Crósta, Alvaro Penteado; Koeberl, Christian

    2015-07-01

    Shatter cones are one of the most widely recognized pieces of evidence for meteorite impact events on Earth, but the process responsible for their formation is still debated. Evidence of melting on shatter cone surfaces has been rarely reported in the literature from terrestrial impact craters but has been recently observed in impact experiments. Although several models for shatter cones formation have been proposed, so far, no one can explain all the observed features. Shatter cones' from the Vista Alegre impact structure, Brazil, formed in fine-grained basalt of the Jurassic-Cretaceous Serra Geral Formation (Paraná large igneous province). A continuous quenched melt film, consisting of a crystalline phase, mica, and amorphous material, decorates the striated surface. Ultracataclasites, containing subrounded pyroxene clasts in an ultrafine-grained matrix, occur subparallel to the striated surface. Several techniques were applied to characterize the crystalline phase in the melt, including Raman spectroscopy and transmission electron microscopy. Results are not consistent with any known mineral, but they do suggest a possible rare or new type of clinopyroxene. This peculiar evidence of melting and cataclasis in relation with shatter cone surfaces is interpreted as the result of tensile fracturing at the tip of a fast propagating shock-induced rupture, which led to the formation of shatter cones at the tail of the shock front, likely during the early stage of the impact events.

  19. Cholesterol depletion by methyl-beta-cyclodextrin enhances myoblast fusion and induces the formation of myotubes with disorganized nuclei.

    PubMed

    Mermelstein, Cláudia S; Portilho, Débora M; Medeiros, Rommel B; Matos, Aline R; Einicker-Lamas, Marcelo; Tortelote, Giovane G; Vieyra, Adalberto; Costa, Manoel L

    2005-02-01

    The formation of a skeletal muscle fiber begins with the withdrawal of committed mononucleated precursors from the cell cycle. These myoblasts elongate while aligning with each other, guided by recognition between their membranes. This step is followed by cell fusion and the formation of long striated multinucleated myotubes. We used methyl-beta-cyclodextrin (MCD) in primary cultured chick skeletal muscle cells to deplete membrane cholesterol and investigate its role during myogenesis. MCD promoted a significant increase in the expression of troponin T, enhanced myoblast fusion, and induced the formation of large multinucleated myotubes with nuclei being clustered centrally and not aligned at the cell periphery. MCD myotubes were striated, as indicated by sarcomeric alpha-actinin staining, and microtubule and desmin filament distribution was not altered. Pre-fusion MCD-treated myoblasts formed large aggregates, with cadherin and beta-catenin being accumulated in cell adhesion contacts. We also found that the membrane microdomain marker GM1 was not present as clusters in the membrane of MCD-treated myoblasts. Our data demonstrate that cholesterol is involved in the early steps of skeletal muscle differentiation.

  20. [Anatomy and physiology of sexuality].

    PubMed

    Cour, F; Droupy, S; Faix, A; Methorst, C; Giuliano, F

    2013-07-01

    Knowledge of the physiology of male and female sexuality has advanced considerably. Initially there is always desire with its biological neuroendocrine components and its emotional field which is particularly marked in women. There is a distinction between "spontaneous" sexual desire related to intrinsic affective, cognitive stimuli, and fantasies, and "reactive" sexual desire in response to physical arousal. There are similarities between men and women concerning the activation of cerebral zones in sexual arousal contexts in laboratory conditions. The neural pathways for sexual arousal are similar between men and women, bringing into play the sympathetic centres of the thoracic and lumbar spinal cord and, at the sacral level, the parasympathetic center and the motoneurons controlling the muscular contractions of the pelviperineal striated muscles. Genital sensitivity is mainly transmitted by the pudendal nerve in both men and women. Sexual arousal in men consists of penile erection, and ejaculation accompanied with orgasm. In women, sexual arousal causes increase in blood to flow to the vagina leading to lubrication and to the vulva leading to the erection of the clitoris and vulvar hyperaemia. The orgasm which can be multiple in women is accompanied by contractions of the striated perineal muscles. Several neurotransmitters are closely involved in the control of sexuality at the central level: dopamine, ocytocin, serotonin, and peripheral: nitric oxide and noradrenaline in men, vasoactive intestinal peptide and neuropeptide Y in women. PMID:23830249

  1. Heterogeneity of myotubes generated by the MyoD and E12 basic helix-loop-helix transcription factors in otherwise non-differentiation growth conditions.

    PubMed

    Grubišić, Vladimir; Gottipati, Manoj K; Stout, Randy F; Grammer, J Robert; Parpura, Vladimir

    2014-02-01

    We used a synthetic biology approach to produce myotubes from mammalian C2C12 myoblasts in non-differentiation growth conditions using the expression of basic helix-loop-helix transcription factors, MyoD and E12, in various combinations and configurations. Our approach not only recapitulated the basics of muscle development and physiology, as the obtained myotubes showed qualities similar to those seen in striated muscle fibers in vivo, but also allowed for the synthesis of populations of myotubes which assumed distinct morphology, myofibrillar development and Ca(2+) dynamics. This fashioned class of biomaterials is suitable for the building blocks of soft actuators in micro-scale biomimetic robotics. This production line strategy can be embraced in reparative medicine as synthetic human myotubes with predetermined morphological/functional properties could be obtained using this very approach. This methodology can be adopted beyond striated muscle for the engineering of other tissue components/cells whose differentiation is governed by the principles of basic helix-loop-helix transcription factors, as in the case, for example, of neural or immune cell types.

  2. AB101. Therapeutic effect of low intensity pulsed ultrasound in stress urinary incontinence

    PubMed Central

    Yang, Bicheng; Lei, Hongen; Guan, Ruili; Li, Huixi; Xin, Zhongcheng

    2016-01-01

    Objective Stress urinary incontinence, a major type of urinary incontinence, increases with age and is often developed after partum injury. Low intensity pulsed ultrasound (LIPUS) has been investigated in the treatment of many diseases showing its ability of restoring soft tissue injury. We investigated the therapeutic effect of low intensity pulsed ultrasound in stress urinary incontinence. Methods Thirty-two Sprague Dawley rats in SUI group underwent vaginal distension (VD) and bilateral ovariectomy mimicking partum injury. Eight rats served as mock operation control. Eight rats each in SUI group was treated with low-dosage LESW (0.03 mJ/mm2), medium-dosage LESW (0.06 mJ/mm2), or high-dosage LESW (0.09 mJ/mm2). The rest eight rats served as none-treatment group. For functional study, leak point pressure test (LPP) was performed 2 weeks after the last LESW. Masson trichrome staining was performed to validate the pathological changes. Results The LPP was restored in medium-dosage LESW and high-dosage LESW groups, but not in low-dosage LESW group. More robust striated muscle regeneration was found in these two groups comparing with the none-treatment group. Conclusions LIPUS ameliorate the symptom of SUI via activating striated muscle regeneration.

  3. Chronic proctalgia and chronic pelvic pain syndromes: New etiologic insights and treatment options

    PubMed Central

    Chiarioni, Giuseppe; Asteria, Corrado; Whitehead, William E

    2011-01-01

    This systematic review addresses the pathophysiology, diagnostic evaluation, and treatment of several chronic pain syndromes affecting the pelvic organs: chronic proctalgia, coccygodynia, pudendal neuralgia, and chronic pelvic pain. Chronic or recurrent pain in the anal canal, rectum, or other pelvic organs occurs in 7% to 24% of the population and is associated with impaired quality of life and high health care costs. However, these pain syndromes are poorly understood, with little research evidence available to guide their diagnosis and treatment. This situation appears to be changing: A recently published large randomized, controlled trial by our group comparing biofeedback, electrogalvanic stimulation, and massage for the treatment of chronic proctalgia has shown success rates of 85% for biofeedback when patients are selected based on physical examination evidence of tenderness in response to traction on the levator ani muscle-a physical sign suggestive of striated muscle tension. Excessive tension (spasm) in the striated muscles of the pelvic floor appears to be common to most of the pelvic pain syndromes. This suggests the possibility that similar approaches to diagnostic assessment and treatment may improve outcomes in other pelvic pain disorders. PMID:22110274

  4. Chronic proctalgia and chronic pelvic pain syndromes: new etiologic insights and treatment options.

    PubMed

    Chiarioni, Giuseppe; Asteria, Corrado; Whitehead, William E

    2011-10-28

    This systematic review addresses the pathophysiology, diagnostic evaluation, and treatment of several chronic pain syndromes affecting the pelvic organs: chronic proctalgia, coccygodynia, pudendal neuralgia, and chronic pelvic pain. Chronic or recurrent pain in the anal canal, rectum, or other pelvic organs occurs in 7% to 24% of the population and is associated with impaired quality of life and high health care costs. However, these pain syndromes are poorly understood, with little research evidence available to guide their diagnosis and treatment. This situation appears to be changing: a recently published large randomized, controlled trial by our group comparing biofeedback, electrogalvanic stimulation, and massage for the treatment of chronic proctalgia has shown success rates of 85% for biofeedback when patients are selected based on physical examination evidence of tenderness in response to traction on the levator ani muscle--a physical sign suggestive of striated muscle tension. Excessive tension (spasm) in the striated muscles of the pelvic floor appears to be common to most of the pelvic pain syndromes. This suggests the possibility that similar approaches to diagnostic assessment and treatment may improve outcomes in other pelvic pain disorders.

  5. Behavioural and electrophysiological chromatic and achromatic contrast sensitivity in an achromatopsic patient.

    PubMed Central

    Heywood, C A; Nicholas, J J; Cowey, A

    1996-01-01

    OBJECTIVES--In cases of incomplete achromatopsia it is unclear whether residual visual function is mediated by intact striate cortex or results from incomplete lesions to extrastriate cortical visual areas. A patient with complete cerebral achromatopsia was tested to establish the nature of his residual vision and to determine the integrity of striate cortex function. METHODS--Behavioural contrast sensitivity, using the method of adjustment, and averaged visually evoked cortical potentials were measured to sinusoidally modulated chromatic and achromatic gratings in an achromatopsic patient and a normal observer. Eye movements were measured in the patient using a Skalar infrared monitoring system. RESULTS--The patient's chromatic contrast sensitivity was normal, indicating that despite his dense colour blindness his occipital cortex still processed information about spatial variations in hue. His sensitivity to achromatic gratings was depressed particularly at high spatial frequencies, possibly because of his jerk nystagmus. These behavioural results were reinforced by the nature of visually evoked responses to chromatic and achromatic gratings, in which total colour blindness coexisted with an almost normal cortical potential to isoluminant chromatic gratings. CONCLUSIONS--The results show that information about chromatic contrast is present in some cortical areas, and coded in a colour-opponent fashion, in the absence of any perceptual experience of colour. PMID:8648330

  6. Mesodermal iPSC–derived progenitor cells functionally regenerate cardiac and skeletal muscle

    PubMed Central

    Quattrocelli, Mattia; Swinnen, Melissa; Giacomazzi, Giorgia; Camps, Jordi; Barthélemy, Ines; Ceccarelli, Gabriele; Caluwé, Ellen; Grosemans, Hanne; Thorrez, Lieven; Pelizzo, Gloria; Muijtjens, Manja; Verfaillie, Catherine M.; Blot, Stephane; Janssens, Stefan; Sampaolesi, Maurilio

    2015-01-01

    Conditions such as muscular dystrophies (MDs) that affect both cardiac and skeletal muscles would benefit from therapeutic strategies that enable regeneration of both of these striated muscle types. Protocols have been developed to promote induced pluripotent stem cells (iPSCs) to differentiate toward cardiac or skeletal muscle; however, there are currently no strategies to simultaneously target both muscle types. Tissues exhibit specific epigenetic alterations; therefore, source-related lineage biases have the potential to improve iPSC-driven multilineage differentiation. Here, we determined that differential myogenic propensity influences the commitment of isogenic iPSCs and a specifically isolated pool of mesodermal iPSC-derived progenitors (MiPs) toward the striated muscle lineages. Differential myogenic propensity did not influence pluripotency, but did selectively enhance chimerism of MiP-derived tissue in both fetal and adult skeletal muscle. When injected into dystrophic mice, MiPs engrafted and repaired both skeletal and cardiac muscle, reducing functional defects. Similarly, engraftment into dystrophic mice of canine MiPs from dystrophic dogs that had undergone TALEN-mediated correction of the MD-associated mutation also resulted in functional striatal muscle regeneration. Moreover, human MiPs exhibited the same capacity for the dual differentiation observed in murine and canine MiPs. The findings of this study suggest that MiPs should be further explored for combined therapy of cardiac and skeletal muscles. PMID:26571398

  7. The cortical representation of shadows cast by retinal blood vessels.

    PubMed Central

    Horton, J C; Adams, D L

    2000-01-01

    PURPOSE: We inquired whether the representation of angioscotomas could be detected in the primary (striate) visual cortex. METHODS: In 12 normal squirrel monkeys, the ocular fundi were photographed and retinal vascular landmarks were projected onto a tangent screen for calibration. Each animal then underwent monocular enucleation under general anesthesia. Animals were perfused after 8 to 10 days, and flat-mounted sections of striate cortex were processed for the metabolic enzyme cytochrome oxidase (CO). RESULTS: In each animal, the cortical region corresponding to the blind spot appeared as a 3 x 2 mm oval in the CO staining pattern. It stood out because it received input from only 1 eye. In 9 of 12 animals, the representation of the major retinal vessels was also visible, for the same reason. In our best examples, CO sections showed about 10 thin lines radiating from the blind spot representation. Some could be traced for 15 mm, all the way to the vertical meridian. Vessels only 12 minutes of arc in diameter were represented in the cortex. Each angioscotoma representation in the cortex could be matched with its corresponding retinal vessel in the fundus. CONCLUSIONS: Our findings show that (1) the visual field map in layer IVc is more precise than indicated by physiological studies, and (2) visual experience must refine the final pattern of geniculocortical projections, given that the retinal vessels can produce a shadow only after birth. Images FIGURE 3 FIGURE 4 FIGURE 5 FIGURE 6 FIGURE 7 FIGURE 12 PMID:11190031

  8. Half-Sarcomere Dynamics in Myofibrils during Activation and Relaxation Studied by Tracking Fluorescent Markers

    PubMed Central

    Telley, Ivo A.; Denoth, Jachen; Stüssi, Edgar; Pfitzer, Gabriele; Stehle, Robert

    2006-01-01

    To study the dynamics of individual half-sarcomeres in striated muscle contraction, myofibrils prepared from rabbit psoas muscle and left ventricles of guinea pig were immunostained with two conjugated antibody complexes consisting of a primary antibody against either α-actinin or myomesin and a secondary fluorescently labeled Fab-fragment. We simultaneously measured force kinetics and determined the positions of the Z-line and M-band signals by fluorescence video microscopy and sophisticated computer vision (tracking) algorithms. Upon calcium activation, sarcomeres and half-sarcomeres shortened nonuniformly. Shortening occurred first rapidly and exponentially during the force rise and then slowly during the force plateau. In psoas myofibrils, time-resolved displacements of the A-band in sarcomeres were observed, i.e., the two halves of individual sarcomeres behaved nonuniformly. Nonuniformity in length changes between the two halves of sarcomeres was comparable to that between two adjacent half-sarcomeres of neighboring sarcomeres. Sequential lengthening of half-sarcomeres was observed in cardiac myofibrils during the rapid phase of force relaxation. The independent dynamics of the halves in a sarcomere reveals the half-sarcomere as the functional unit rather than the structural unit, the sarcomere. The technique will facilitate the study of filament sliding within individual half-sarcomeres and the mechanics of intersegmental chemomechanical coupling in multisegmental striated muscles. PMID:16239326

  9. Localization of centrins in the hypotrich ciliate Paraurostyla weissei.

    PubMed

    Lemullois, Michel; Fryd-Versavel, Ghislaine; Fleury-Aubusson, Anne

    2004-09-01

    Centrins are ubiquitous cytoskeletal proteins that are generally associated with the centrosome and form large cytoskeletal networks in protists. To obtain more data on the respective role of different centrin proteins, we studied their distribution and behavior in one ciliate species, Paraurostyla weissei, using specific antibodies. In this species, only two major proteins of 21 and 24 kDa corresponding to centrins, were identified by 1D and 2D electrophoresis. Immunofluorescence analysis showed that these two proteins displayed non-overlapping localization in the interphase cell and during morphogenesis. Both centrin proteins localize on the fibrous network linking the oral basal bodies in the interphase cell and in the form of marginal dots, which correspond to the proximal ends of the striated rootlets; the 21 kDa centrin was also detected within the basal bodies, whereas the 24 kDa centrin allowed identifying new structures, the frontal dashes. During morphogenesis, the 21 kDa centrin locates at the basal bodies, while the 24 kDa centrin is detected along the striated rootlets and in close association with the basal bodies pairs. These data are discussed in terms of the potential roles of the two centrins in different cellular functions.

  10. Drug Insight: biological effects of botulinum toxin A in the lower urinary tract

    PubMed Central

    Chancellor, Michael B; Fowler, Clare J; Apostolidis, Apostolos; de Groat, William C; Smith, Christopher P; Somogyi, George T; Aoki, K Roger

    2011-01-01

    SUMMARY Botulinum toxins can effectively and selectively disrupt and modulate neurotransmission in striated muscle. Recently, urologists have become interested in the use of these toxins in patients with detrusor overactivity and other urological disorders. In both striated and smooth muscle, botulinum toxin A (BTX-A) is internalized by presynaptic neurons after binding to an extracellular receptor (ganglioside and presumably synaptic vesicle protein 2C). In the neuronal cytosol, BTX-A disrupts fusion of the acetylcholine-containing vesicle with the neuronal wall by cleaving the SNAP-25 protein in the synaptic fusion complex. The net effect is selective paralysis of the low-grade contractions of the unstable detrusor, while still allowing high-grade contraction that initiates micturition. Additionally, BTX-A seems to have effects on afferent nerve activity by modulating the release of ATP in the urothelium, blocking the release of substance P, calcitonin gene-related peptide and glutamate from afferent nerves, and reducing levels of nerve growth factor. These effects on sensory feedback loops might not only help to explain the mechanism of BTX-A in relieving symptoms of overactive bladder, but also suggest a potential role for BTX-A in the relief of hyperalgesia associated with lower urinary tract disorders. PMID:18461049

  11. Neuropsychological changes after surgery for anterior communicating artery aneurysm.

    PubMed

    Jimbo, H; Hanakawa, K; Ozawa, H; Dohi, K; Sawabe, Y; Matsumoto, K; Nagata, K

    2000-02-01

    Neuropsychological disturbances following surgery for anterior communicating artery aneurysms were analyzed in 26 patients (11 males, 15 females) using the Hasegawa dementia scale-revised (HDS-R) over a 3-year period. The patients were aged from 34 to 76 years (mean 54.1 years). Lesions in the frontal lobe were evaluated using computed tomography (CT). Twenty-three patients had symptoms over the course. Four patients had basal forebrain lesion, five had ventral frontal lesion, and 12 had no lesion. Patients with basal forebrain lesion and no lesion tended to show disorientation. The mean HDS-R score was 10.2 points in the patients with ventral frontal lesion, and 13.5 points in the patients with no lesion. These scores are within the range for dementia. The mean HDS-R score in patients with basal forebrain and striate lesions was over 25 points and beyond the range for dementia. Significant differences were observed in the HDS-R score between patients with ventral frontal lesion and basal forebrain lesion, and between patients with no lesion and basal forebrain lesion (p < 0.05). Recovery from neuropsychological disturbances was poorer in patients with ventral frontal lesion and no lesion compared to those with basal forebrain and striate lesions, and their symptoms tended to persist.

  12. Decoding the direction of imagined visual motion using 7 T ultra-high field fMRI

    PubMed Central

    Emmerling, Thomas C.; Zimmermann, Jan; Sorger, Bettina; Frost, Martin A.; Goebel, Rainer

    2016-01-01

    There is a long-standing debate about the neurocognitive implementation of mental imagery. One form of mental imagery is the imagery of visual motion, which is of interest due to its naturalistic and dynamic character. However, so far only the mere occurrence rather than the specific content of motion imagery was shown to be detectable. In the current study, the application of multi-voxel pattern analysis to high-resolution functional data of 12 subjects acquired with ultra-high field 7 T functional magnetic resonance imaging allowed us to show that imagery of visual motion can indeed activate the earliest levels of the visual hierarchy, but the extent thereof varies highly between subjects. Our approach enabled classification not only of complex imagery, but also of its actual contents, in that the direction of imagined motion out of four options was successfully identified in two thirds of the subjects and with accuracies of up to 91.3% in individual subjects. A searchlight analysis confirmed the local origin of decodable information in striate and extra-striate cortex. These high-accuracy findings not only shed new light on a central question in vision science on the constituents of mental imagery, but also show for the first time that the specific sub-categorical content of visual motion imagery is reliably decodable from brain imaging data on a single-subject level. PMID:26481673

  13. Chemotherapy-Induced Weakness and Fatigue in Skeletal Muscle: The Role of Oxidative Stress

    PubMed Central

    St. Clair, Daret K.

    2011-01-01

    Abstract Significance Fatigue is one of the most common symptoms of cancer and its treatment, manifested in the clinic through weakness and exercise intolerance. These side effects not only compromise patient's quality of life (QOL), but also diminish physical activity, resulting in limited treatment and increased morbidity. Recent Advances Oxidative stress, mediated by cancer or chemotherapeutic agents, is an underlying mechanism of the drug-induced toxicity. Nontargeted tissues, such as striated muscle, are severely affected by oxidative stress during chemotherapy, leading to toxicity and dysfunction. Critical Issues These findings highlight the importance of investigating clinically applicable interventions to alleviate the debilitating side effects. This article discusses the clinically available chemotherapy drugs that cause fatigue and oxidative stress in cancer patients, with an in-depth focus on the anthracycline doxorubicin. Doxorubicin, an effective anticancer drug, is a primary example of how chemotherapeutic agents disrupt striated muscle function through oxidative stress. Future Directions Further research investigating antioxidants could provide relief for cancer patients from debilitating muscle weakness, leading to improved quality of life. Antioxid. Redox Signal. 15, 2543–2563. PMID:21457105

  14. Anococcygeal Raphe Revisited: A Histological Study Using Mid-Term Human Fetuses and Elderly Cadavers

    PubMed Central

    Arakawa, Takashi; Abe, Hiroshi; Abe, Shinichi; Cho, Baik Hwan; Murakami, Gen; Sugihara, Kenichi

    2012-01-01

    Purpose We recently demonstrated the morphology of the anococcygeal ligament. As the anococcygeal ligament and raphe are often confused, the concept of the anococcygeal raphe needs to be re-examined from the perspective of fetal development, as well as in terms of adult morphology. Materials and Methods We examined the horizontal sections of 15 fetuses as well as adult histology. From cadavers, we obtained an almost cubic tissue mass containing the dorsal wall of the anorectum, the coccyx and the covering skin. Most sections were stained with hematoxylin and eosin or Masson-trichrome solution. Results The adult ligament contained both smooth and striated muscle fibers. A similar band-like structure was seen in fetuses, containing: 1) smooth muscle fibers originating from the longitudinal muscle coat of the anal canal and 2) striated muscle fibers from the external anal sphincter (EAS). However, in fetuses, the levator ani muscle did not attach to either the band or the coccyx. Along and around the anococcygeal ligament, we did not find any aponeurotic tissue with transversely oriented fibers connecting bilateral levator ani slings. Instead, in adults, a fibrous tissue mass was located at a gap between bilateral levator ani slings; this site corresponded to the dorsal side of the ligament and the EAS in the immediately deep side of the natal skin cleft. Conclusion We hypothesize that a classically described raphe corresponds to the specific subcutaneous tissue on the superficial or dorsal side of the anococcygeal ligament. PMID:22665356

  15. THE GALACTIC MAGNETIC FIELD

    SciTech Connect

    Jansson, Ronnie; Farrar, Glennys R.

    2012-12-10

    With this Letter, we complete our model of the Galactic magnetic field (GMF), by using the WMAP7 22 GHz total synchrotron intensity map and our earlier results to obtain a 13-parameter model of the Galactic random field, and to determine the strength of the striated random field. In combination with our 22-parameter description of the regular GMF, we obtain a very good fit to more than 40,000 extragalactic Faraday rotation measures and the WMAP7 22 GHz polarized and total intensity synchrotron emission maps. The data call for a striated component to the random field whose orientation is aligned with the regular field, having zero mean and rms strength Almost-Equal-To 20% larger than the regular field. A noteworthy feature of the new model is that the regular field has a significant out-of-plane component, which had not been considered earlier. The new GMF model gives a much better description of the totality of data than previous models in the literature.

  16. Expression and cellular localizaion of melatonin-synthesizing enzymes in rat and human salivary glands.

    PubMed

    Shimozuma, Masashi; Tokuyama, Reiko; Tatehara, Seiko; Umeki, Hirochika; Ide, Shinji; Mishima, Kenji; Saito, Ichiro; Satomura, Kazuhito

    2011-04-01

    Melatonin, discovered in 1958, is secreted by the pineal gland primarily during the night. Its secretion is controlled by the light/dark cycle of the environment. Melatonin is also produced in and secreted by various extrapineal organs, tissues and cells and its synthesizing enzyme arylalkylamine N-acetyltransferase (AANAT) is expressed in various extrapineal organs, tissues and cells. Recently, it was reported that melatonin is present in saliva, but it is not certain where melatonin was synthesized and whether it was secreted into saliva and what function it may have in saliva. The present study was performed to investigate where melatonin was synthesized and whether it was secreted by salivary glands into saliva. We performed immunohistochemical analysis of the expression of AANAT in rat parotid, submandibular and sublingual glands and the expression of both AANAT and hydroxyindole-O-methyltransferase (HIOMT) in human submandibular glands. We evaluated the expression of AANAT and HIOMT mRNA in rat submandibular glands by quantitative reverse transcription-polymerase chain reaction. As a result, we observed expression of AANAT in epithelial cells of striated ducts in rat salivary glands and expression of AANAT, HIOMT and melatonin in epithelial cells of striated ducts in human submandibular glands. In addition, we also confirmed the expression of the most potent melatonin receptor, melatonin 1a receptor, in rat buccal mucosa. Our findings suggest that melatonin might be produced and secreted by salivary glands directly into saliva and that it might play some physiological role in the oral cavity.

  17. RICH-1 has a BIN/Amphiphysin/Rvsp domain responsible for binding to membrane lipids and tubulation of liposomes.

    PubMed

    Richnau, Ninna; Fransson, Asa; Farsad, Khashayar; Aspenström, Pontus

    2004-07-30

    RhoGAP interacting with CIP4 homologs-1 (RICH-1) was previously found in a yeast two-hybrid screen for proteins interacting with the SH3 domain of the Cdc42-interacting protein 4 (CIP4). RICH-1 was shown to be a RhoGAP for Cdc42 and Rac. In this study, we show that the BIN/Amphiphysin/Rvsp (BAR) domain in RICH-1 confers binding to membrane lipids, and has the potential to deform spherical liposomes into tubes. In accordance with previous findings for the BAR domains in endophilin and amphiphysin, RICH-1-induced tubes appeared striated. We propose that these striated structures are formed by oligomerization of RICH-1 through a putative coiled-coil region within the BAR domain. In support of this notion, we show that RICH-1 forms oligomers in the presence of the chemical cross-linker BS3. These results point to an involvement of RICH-1 in membrane deformation events. PMID:15240152

  18. Unique cellular structures in the parotid gland of an Old world fruit bat, Pteropus lylei (Lyle's flying fox).

    PubMed

    Lanlua, Passara; Sricharoenvej, Sirinush; Niyomchan, Apichaya; Chico, Diane E

    2007-01-01

    Pteropus lylei (Lyle's flying fox), an Old World fruit bat, consumes only ripe fruit, which contains low protein and sodium. The carpophagous diet of P. lylei presents an adaptive challenge for salivary glands to conserve sufficient nutrition for living. Therefore, the parotid glands in both sexes were investigated by using light microscopy and transmission electron microscopy. No structural difference was observed in the parotid glands between sexes. The acinar cell contained dense serous secretory granules, prominent luminal microvilli and intercellular canaliculi. The intercalated duct exhibited simple cuboidal epithelium with no secretory granule. Striated duct consisted of simple columnar epithelium with basal striation, numerous elongated mitochondria, and apical vesicles. In the interlobular duct, simple tall columnar epithelium and apocrine secretion were found. The interlobar and excretory ducts surprisingly contained continuous capillaries that intervened in stratified cuboidal epithelium. In addition, there were several blood vessels around the interlobular, interlobar and excretory ducts. The morphological adaptation of the parotid gland observed in P. lylei enables this species to obtain sufficient nutrients from the preferred consumption of ripe fruit. Serous secretory granule was suitable for digestion of ripe fruit. A well-developed striated duct, continuous capillaries among the epithelial cells of interlobar and excretory ducts, and numerous blood vessels around these ducts enhanced the reabsorption of amino acids and ions. Structural variations in the parotid gland can indicate not only a correlation to diet and survival but also a close relationship of the Old World fruit bat to other kinds of bats.

  19. Objective analysis of toolmarks in forensics

    NASA Astrophysics Data System (ADS)

    Grieve, Taylor N.

    Since the 1993 court case of Daubert v. Merrell Dow Pharmaceuticals, Inc. the subjective nature of toolmark comparison has been questioned by attorneys and law enforcement agencies alike. This has led to an increased drive to establish objective comparison techniques with known error rates, much like those that DNA analysis is able to provide. This push has created research in which the 3-D surface profile of two different marks are characterized and the marks' cross-sections are run through a comparative statistical algorithm to acquire a value that is intended to indicate the likelihood of a match between the marks. The aforementioned algorithm has been developed and extensively tested through comparison of evenly striated marks made by screwdrivers. However, this algorithm has yet to be applied to quasi-striated marks such as those made by the shear edge of slip-joint pliers. The results of this algorithm's application to the surface of copper wire will be presented. Objective mark comparison also extends to comparison of toolmarks made by firearms. In an effort to create objective comparisons, microstamping of firing pins and breech faces has been introduced. This process involves placing unique alphanumeric identifiers surrounded by a radial code on the surface of firing pins, which transfer to the cartridge's primer upon firing. Three different guns equipped with microstamped firing pins were used to fire 3000 cartridges. These cartridges are evaluated based on the clarity of their alphanumeric transfers and the clarity of the radial code surrounding the alphanumerics.

  20. Cellular neurothekeoma of the oral mucosa.

    PubMed

    Barrett, A W; Suhr, M

    2001-12-01

    Cellular neurothekeoma is an unusual benign neoplasm which, despite its name, is of uncertain origin. This report describes a cellular neurothekeoma of the cheek mucosa, the first at this site. The tumour presented in a 29-year-old man as a discrete mucosal thickening. Histology showed a generally well circumscribed, but unencapsulated, solid tumour which replaced the entire lamina propria and permeated between minor salivary glands and bundles of striated muscle in the submucosa. There was a sub-epithelial Grenz zone. The tumour was composed of nodules of pale, epithelioid cells separated by fascicles of spindle cells, with smaller strands and nests superficially. The nuclei were vesicular and, though mainly bland, occasionally atypical. The stroma was moderately infiltrated by mixed chronic inflammatory cells. Prominent nerves and blood vessels were seen at the periphery of the lesion, and neoplastic cells were noted within intact striated muscle fascicles. With immunohistochemistry, all the neoplastic cells strongly expressed NKI/C3, synaptophysin, neurone-specific enolase and vimentin, some expressed smooth muscle actin and PGP 9.5, but all were negative for S100, factor XIIIa, CD34, CD56, CD57, CD68, chromogranin A, desmin, epithelial membrane antigen and von Willebrand factor. The origin of the lesion is thus speculative. It was, however, completely excised and in 12 months there has been no recurrence.

  1. Lymphoepithelial duct lesions in Sjögren-type sialadenitis.

    PubMed

    Ihrler, S; Zietz, C; Sendelhofert, A; Riederer, A; Löhrs, U

    1999-04-01

    It is not clear, whether the so-called basal cells of the salivary striated ducts are an independent cell-type distinct from myoepithelial cells, making characterization of the cell proliferation typical of the duct lesions in Sjögren-type sialadenitis/benign lymphoepithelial lesion (BLEL) difficult. An immunohistochemical investigation including different cytokeratin subtypes, alpha-actin, Ki-67 and Bcl-2 was directed at the epithelial cytoskeleton in normal parotid parenchyma (n=8), BLEL (n=12), HIV-associated lymphoepithelial cysts (n=8) and palatine tonsils (n=8). There are profound morphological and functional differences between basal and myoepithelial cells in the normal salivary duct. Development of duct lesions in BLEL arises from basal cell hyperplasia of striated ducts with aberrant differentiation into a multi-layered and reticulated epithelium, characterized by profound alteration of the cytokeratin pattern. This functionally inferior, metaplastic epithelium is similar to the lymphoepithelial crypt epithelium of palatine tonsils. The often postulated participation of myoepithelial cells in duct lesions of Sjögren disease/BLEL cannot be supported. We regard the designations lymphoepithelial lesion and lymphoepithelial metaplasia as the most appropriate.

  2. Response characteristics of the cells of cortical area 21a of the cat with special reference to orientation specificity.

    PubMed

    Wimborne, B M; Henry, G H

    1992-04-01

    1. Extracellular recording using tungsten-in-glass microelectrodes was conducted on 115 neurons in area 21a of fifteen anaesthetized cats. Quantitative analysis using computer-controlled display and collecting routines were used to investigate the excitatory and inhibitory regions of the receptive field and to see if interaction, within and between these regions, contributed to the response properties of the cells. 2. The responses of the cells in the sample appeared to arise from a single, homogeneous class. All cells had single discharge regions which responded with composite ON/OFF firing to a stationary flashing bar. The same region also responded to moving light and dark bars and edges. There was little evidence of inhibition as measured by the suppression of spontaneous or induced firing. Most cells had relatively small receptive fields (primary width: mean = 2.1 +/- 0.9 deg (S.D.); n = 108), all were binocular and were located within 15.0 deg of the visual axes. 3. All cells responded well to slowly moving stimuli but generally failed to respond to stimuli moving faster than 10.0 deg s-1. All responses were bi-directional and, although many showed evidence of length summation, there was no sign of linear summation. 4. Despite the absence of significant sideband inhibition many cells were acutely tuned for orientation (half-width at half-height: mean = 15.6 +/- 5.3 deg; n = 48). To investigate this property further, cells were analysed to assess the effect of changing the length of a moving bar stimulus on the acuteness of the orientation tuning curve. Short bars, of similar length to the width of the receptive field, had orientation tuning curves of equivalent sharpness to those obtained with longer bars. 5. The equivalence of orientation tuning for long and short bars stands in contrast to the results obtained for both simple (S) and complex (C) cells of the striate cortex where tuning for the longer bar is sharper than that for the shorter. The result from

  3. Nucleotide and protein sequences for dog masticatory tropomyosin identify a novel Tpm4 gene product.

    PubMed

    Brundage, Elizabeth A; Biesiadecki, Brandon J; Reiser, Peter J

    2015-10-01

    Jaw-closing muscles of several vertebrate species, including members of Carnivora, express a unique, "masticatory", isoform of myosin heavy chain, along with isoforms of other myofibrillar proteins that are not expressed in most other muscles. It is generally believed that the complement of myofibrillar isoforms in these muscles serves high force generation for capturing live prey, breaking down tough plant material and defensive biting. A unique isoform of tropomyosin (Tpm) was reported to be expressed in cat jaw-closing muscle, based upon two-dimensional gel mobility, peptide mapping, and immunohistochemistry. The objective of this study was to obtain protein and gene sequence information for this unique Tpm isoform. Samples of masseter (a jaw-closing muscle), tibialis (predominantly fast-twitch fibers), and the deep lateral gastrocnemius (predominantly slow-twitch fibers) were obtained from adult dogs. Expressed Tpm isoforms were cloned and sequencing yielded cDNAs that were identical to genomic predicted striated muscle Tpm1.1St(a,b,b,a) (historically referred to as αTpm), Tpm2.2St(a,b,b,a) (βTpm) and Tpm3.12St(a,b,b,a) (γTpm) isoforms (nomenclature reflects predominant tissue expression ("St"-striated muscle) and exon splicing pattern), as well as a novel 284 amino acid isoform observed in jaw-closing muscle that is identical to a genomic predicted product of the Tpm4 gene (δTpm) family. The novel isoform is designated as Tpm4.3St(a,b,b,a). The myofibrillar Tpm isoform expressed in dog masseter exhibits a unique electrophoretic mobility on gels containing 6 M urea, compared to other skeletal Tpm isoforms. To validate that the cloned Tpm4.3 isoform is the Tpm expressed in dog masseter, E. coli-expressed Tpm4.3 was electrophoresed in the presence of urea. Results demonstrate that Tpm4.3 has identical electrophoretic mobility to the unique dog masseter Tpm isoform and is of different mobility from that of muscle Tpm1.1, Tpm2.2 and Tpm3.12 isoforms. We

  4. Chicxulub Impact Ejecta in Belize

    NASA Technical Reports Server (NTRS)

    Ocampo, A.; Pope, K.; Fischer, A.; Alvarez, W.; Fouke, B.; Asaro, F.; Webster, C., Jr.; Vega, F.; Smith, J.; Fritsche, A. E.

    1997-01-01

    Chicxulub ejecta deposits in Belize provide the closest exposures of ejecta to the crater and the only exposures of proximal ejecta deposited in a terrestrial environment. A quarry on Albion Island in northern Belize exposes Late Cretaceous, possibly Maastrichtian, carbonate platform sediments that were folded, eroded, and subaerially weathered prior to the deposition of coarse ejecta from Chicxulub. These ejecta deposits are composed of a basal, about 1-m-thick clay and dolomite Spheroid Bed overlain by a about 15-m-thick coarse Diamictite Bed. Many and perhaps most of the clay spheroids are altered glass. Many dolomite spheroids have concentric layers and angular cores are probably of accretionary lapilli origin. A slight Ir concentration (111-152 ppt) was detected in the base of the Spheroid Bed. The Diamictite Bed contains about 10% altered glass, rare shocked quartz, 3-8 m diameter boulders and striated and polished cobbles, one with a penetrating rock chip that plastically deformed the cobble. Ejecta deposits extend to the surface at Albion and the maximum thickness in this area is not known. Ejecta deposits are exposed in several roadside quarries in the Cayo District of central Belize. The Late Cretaceous here is also represented by carbonate platform sediments. The upper surface of the carbonate platform is a highly irregular and extensively recrystallized horizon possibly representing deep karst weathering. Approximately 30 in of diamictite overlies this horizon with a texture similar to the Diamictite Bed at the Albion quarry, but with a more diverse lithology. In three locations the Cayo diamictites, contain red clay layers with abundant polished and striated limestone pebbles and cobbles called Pook's Pebbles, several of which have penetrating rock chips and ablated surfaces. We interpret the Albion Spheroid Bed as a deposit from the impact vapor plume and the Albion and Cayo diamictites as the result of a turbulent flow that contained debris derived

  5. Nucleotide and protein sequences for dog masticatory tropomyosin identify a novel Tpm4 gene product

    PubMed Central

    Reiser, Peter J.

    2016-01-01

    Jaw-closing muscles of several vertebrate species, including members of Carnivora, express a unique, “masticatory”, isoform of myosin heavy chain, along with isoforms of other myofibrillar proteins that are not expressed in most other muscles. It is generally believed that the complement of myofibrillar isoforms in these muscles serves high force generation for capturing live prey, breaking down tough plant material and defensive biting. A unique isoform of tropomyosin (Tpm) was reported to be expressed in cat jaw-closing muscle, based upon two-dimensional gel mobility, peptide mapping, and immunohistochemistry. The objective of this study was to obtain protein and gene sequence information for this unique Tpm isoform. Samples of masseter (also a jaw-closing muscle), tibialis (with predominantly fast-twitch fibers), and the deep lateral gastrocnemius (predominantly slow-twitch fibers) were obtained from adult dogs. Expressed Tpm isoforms were cloned and sequencing yielded cDNAs that were identical to genomic predicted striated muscle Tpm1.1St(a,b,b,a) (historically referred to as αTpm), Tpm2.2St(a,b,b,a) (βTpm) and Tpm3.12St(a,b,b,a) (cTpm) isoforms (nomenclature reflects predominant tissue expression (“St”—striated muscle) and exon splicing pattern), as well as a novel 284 amino acid isoform observed in jaw-closing muscle that is identical to a genomic predicted product of the Tpm4 gene (δTpm) family. The novel isoform is designated as Tpm4.3St(a,b,b,a). The myofibrillar Tpm isoform expressed in dog masseter exhibits a unique electrophoretic mobility on gels containing 6 M urea, compared to other skeletal Tpm isoforms. To validate that the cloned Tpm4.3 isoform is the Tpm expressed in dog masseter, E. coli-expressed Tpm4.3 was electrophoresed in the presence of urea. Results demonstrate that Tpm4.3 has identical electrophoretic mobility to the unique dog masseter Tpm isoform and is of different mobility from that of muscle Tpm1.1, Tpm2.2 and Tpm3

  6. Late Permian Palynology and depositional environment of Chintalapudi sub basin, Pranhita-Godavari basin, Andhra Pradesh, India

    NASA Astrophysics Data System (ADS)

    Jha, Neerja; Pauline Sabina, K.; Aggarwal, Neha; Mahesh, S.

    2014-01-01

    The present study deals with the palynological dating, correlation and depositional setting of the sediments from bore cores MGP-11 and MGP-4 from Gauridevipet area of Chintalapudi sub-basin of Godavari master basin, south India. On the basis of palynological studies, three palynoassemblages have been identified, one in bore core MGP-11 a Faunipollenites (=Protohaploxypinus) and Striasulcites assemblage and two in bore core MGP-4; one is characterized by the dominance of striate bisaccates and Densipollenites and the other by Striatopodocarpites and Cresentipollenites palynoassemblages. The other stratigraphically significant taxa include Guttulapollenites hannonicus, Lunatisporites noviaulensis, Lunatisporites pellucidus, Densoisporites contactus, Chordasporites australiensis, Goubinispora spp., Lundbladispora microconata, Lundbladispora raniganjensis and Klausipollenites schaubergeri. The recovered taxa suggest a Late Permian, Lopingian age for these rocks. This interpretation is based on the correlation of the assemblages with similar assemblages from previous Gondwana studies chiefly Densipollenites magnicorpus Zone of Damodar Basin, India and Late Permian palynoassemblages from Africa, Antarctica, Australia and South America. On the basis of palaeobotanical affinity of the identified microflora it has been inferred that the peat forming plant community was composed mainly of gymnosperm pollen attributable to glossopterids, that includes striate and non-striate bisaccates and paucity of cordaites which includes monosaccates. Spores are subordinate and are derived from lycopsids (Lundbladispora, Densoisporites), sphenopsids (Latosporites) and filicopsids (Horriditriletes, Lophotriletes, Verrucosisporites, Osmundacidites, Leiotriletes, Callumispora, Brevitriletes and Microbaculispora) occurring in variable proportions. The dominance of subarborescent/arborescent vegetation suggests a development in a forest swamp probably in a small distant marginal part of the

  7. Temporal encoding of two-dimensional patterns by single units in primate primary visual cortex. I. Stimulus-response relations.

    PubMed

    Richmond, B J; Optican, L M; Spitzer, H

    1990-08-01

    1. Previously we developed a new approach for investigating visual system neuronal activity in which single neurons are considered to be communication channels transmitting stimulus-dependent codes in their responses. Application of this approach to the stimulus-response relations of inferior temporal (IT) neurons showed that these carry stimulus-dependent information in the temporal modulation as well as in the strength of their responses. IT cortex is a late station in the visual processing stream. Presumably the neuronal properties arise from the properties of the inputs. However, the discovery that IT neuronal spike trains transmit information in stimulus-dependent temporally modulated codes could not be assumed to be true for those earlier stations, so the techniques used in the earlier study were applied to single-striate cortical neurons in the studies reported here. 2. Single-striate cortical neurons were recorded from three awake, fixating rhesus monkeys. The neurons were stimulated by two sets of patterns. The first set was made up of 128 black-and-white patterns based on a complete, orthogonal set of two-dimensional Walsh-Hadamard functions. These stimuli appear as combinations of black-and-white rectangles and squares, and they fully span the range of all possible black-and-white pictures that can be constructed in an 8 x 8 grid. Except for the stimulus that appeared as an all-white or all-black square, each stimulus had equal areas of white and black. The second stimulus set was made up of single bars constructed in the same 8 x 8 grid as the Walsh stimuli. These were presented both as black against a gray background and white against a gray background. The stimuli were centered on the receptive field, and each member of the stimulus set was presented once before any stimulus appeared again. 3. The responses of 21 striate cortical neurons were recorded and analyzed. Two were identified as simple cells and the other 19 as complex cells according to the

  8. Electrolichas circumbalticus gen. et sp. nov. (Coleoptera: Byrrhoidea: Ptilodactylidae) from Baltic amber, the first anchytarsine toed-winged beetle described from Europe.

    PubMed

    Alekseev, Vitalii I; Jäch, Manfred A

    2016-01-01

    A new genus and species of Ptilodactylidae, Electrolichas circumbalticus gen. et sp. nov., the first fossil representative of the subfamily Anchytarsinae, is described from Baltic amber. This Eocene beetle can be distinguished from the extant genera of Anchytarsinae by the combination of the following characters: labrum transverse, terminal segment of maxillary palps cylindrical, antennae with non-articulated rami, basal pronotal margin only very finely crenulate, lacking a median denticle, anterior margin of scutellum not excised medially, elytra not striate, tarsi not pseudotetramerous, proportional lengths: 1.5: 1.2: 1.2: 1.1: 1.5, flashy pads on apex of first tarsomere as well as on tarsomeres 2-4. A list of the extant species of Anchytarsinae is provided. Both hitherto described fossil ptilodactylid genera are briefly discussed. PMID:27395736

  9. Alterations in Skeletal Muscle Microcirculation of Head-Down Tilted Rats

    NASA Technical Reports Server (NTRS)

    Musacchia, X. J.; Stepke, Bernhard; Fleming, John T.; Joshua, Irving G.

    1992-01-01

    In this study we assessed the function of microscopic blood vessels in skeletal muscle (cremaster muscle) for alterations which may contribute to the observed elevation of blood pressure associated with head-down tilted whole body suspension (HDT/WBS), a model of weightlessness. Arteriolar baseline diameters, vasoconstrictor responses to norepinephrine (NE) and vasodilation to nitroprusside (NP) were assessed in control rats, rats suspended for 7 or 14 day HDT/WBS rats, and rats allowed to recover for 1 day after 7 days HDT/WBS. Neither baseline diameters nor ability to dilate were influenced by HDT/WBS. Maximum vasoconstriction to norepinephrine was significantly greater in arterioles of hypertensive 14 day HDT/WBS rats. This first study of the intact microvasculature in skeletal muscle indicates that an elevated contractility of arterioles to norepinephrine in suspended rats, and suggests an elevated peripheral resistance in striated muscle may contribute to the increase in blood pressures among animals subjected to HDT/WBS.

  10. The solution of the Elrod algorithm for a dynamically loaded journal bearing using multigrid techniques

    NASA Technical Reports Server (NTRS)

    Woods, Claudia M.; Brewe, David E.

    1988-01-01

    A numerical solution to a theoretical model of vapor cavitation in a dynamically loaded journal bearing is developed utilizing a multigrid iteration technique. The method is compared with a noniterative approach in terms of computational time and accuracy. The computational model is based on the Elrod algorithm, a control volume approach to the Reynolds equation which mimics the Jakobsson-Floberg and Olsson cavitation theory. Besides accounting for a moving cavitation boundary and conservation of mass at the boundary, it also conserves mass within the cavitated region via a smeared mass or striated flow extending to both surfaces in the film gap. The mixed nature of the equations (parabolic in the full film zone and hyperbolic in the cavitated zone) coupled with the dynamic aspects of the problem create interesting difficulties for the present solution approach. Emphasis is placed on the methods found to eliminate solution instabilities. Excellent results are obtained for both accuracy and reduction of computational time.

  11. The solution of the Elrod algorithm for a dynamically loaded journal bearing using multigrid techniques

    NASA Technical Reports Server (NTRS)

    Woods, C. M.; Brewe, D. E.

    1989-01-01

    A numerical solution to a theoretical model of vapor cavitation in a dynamically loaded journal bearing is developed utilizing a multigrid iteration technique. The method is compared with a noniterative approach in terms of computational time and accuracy. The computational model is based on the Elrod algorithm, a control volume approach to the Reynolds equation which mimics the Jakobsson-Floberg and Olsson cavitation theory. Besides accounting for a moving cavitation boundary and conservation of mass at the boundary, it also conserves mass within the cavitated region via a smeared mass or striated flow extending to both surfaces in the film gap. The mixed nature of the equations (parabolic in the full film zone and hyperbolic in the cavitated zone) coupled with the dynamic aspects of the problem create interesting difficulties for the present solution approach. Emphasis is placed on the methods found to eliminate solution instabilities. Excellent results are obtained for both accuracy and reduction of computational time.

  12. Fine structure of the parotid gland in tree shrew (Tupaia glis).

    PubMed

    Suzuki, S; Mifune, H; Nishida, T; Obara, T; Kamimura, R; Sakamoto, H; Mohammad Abdul, A; Nishinakagawa, H

    1995-10-01

    The parotid glands of Tupaia glis were examined by light and transmission electron microscopy. The acinar cells were seromucous in nature, and contained many acidophilic granules with strong affinity for periodic acid-Schiff (PAS) and weak affinity for alcian blue (AB). These granules consisted of a fine granular matrix of moderate density in which a denser corpuscles or semilunar materials were present. Intercalated duct cells had a few fine vesicles, vacuoles and very few dense granules in the apical region. In occasional epithelial cells, acidophilic, PAS-positive and AB-negative bodies with moderate density were observed in the supranuclear region. The striated ducts consisted of columnar light and dark cells containing round or small ovoid granules of moderate density and did not show the granular duct as seen in the parotid glands of kobe mole and tenrec which are placed in the order insectivora.

  13. Spatial contrast sensitivity in unilateral cerebral ischaemic lesions involving the posterior visual pathway.

    PubMed

    Bulens, C; Meerwaldt, J D; van der Wildt, G J; Keemink, C J

    1989-04-01

    Contrast sensitivity function was studied in 16 patients with unilateral ischaemic lesions involving the posterior visual pathway. Sixty-two percent of the patients showed contrast sensitivity loss in at least one eye for horizontal or vertical stimulus orientation. Visual perception was distorted in a qualitatively different way according to the anteroposterior site of the lesion. Patients with occipital or occipitotemporal lesions showed high spatial frequency selective losses and patients with temporal or parietal lesions low frequency selective losses. Stimulus orientation selectivity was observed in patients with lesions of the primary visual cortex as well as in patients with lesions anterior to the striate cortex. Contrast sensitivity orientation-selective losses were demonstrated in 14 of the 17 'affected' eyes.

  14. The dorsal skinfold chamber: A versatile tool for preclinical research in tissue engineering and regenerative medicine.

    PubMed

    Laschke, M W; Menger, M D

    2016-01-01

    The dorsal skinfold chamber is a rodent model for non-invasive microcirculatory analyses of striated muscle and skin tissue throughout an observation period of 2-3 weeks. In combination with intravital fluorescence microscopy, this model allows the quantitative assessment of dynamic processes such as inflammation, angiogenesis, vascular remodelling and microcirculation. Accordingly, the dorsal skinfold chamber is increasingly used for preclinical research in tissue engineering and regenerative medicine. This includes studies on biocompatibility, vascularisation and incorporation of medical implants and artificial tissue constructs. Moreover, the chamber implantation procedure has been modified to analyse primary and secondary wound healing as well as revascularisation and blood perfusion of dermal substitutes, skin grafts and myocutaneous flaps. Hence, the dorsal skinfold chamber model does not only provide deep insights into fundamental regenerative mechanisms but also represents a versatile tool for the development of novel therapeutic strategies. PMID:27646143

  15. Lipoid proteinosis: clinical, histologic, and ultrastructural investigations.

    PubMed

    Muda, A O; Paradisi, M; Angelo, C; Mostaccioli, S; Atzori, F; Puddu, P; Faraggiana, T

    1995-10-01

    The case of a 12-year-old boy with lipoid proteinosis is reported. Physical examination revealed long-standing varicella-like scars and areas of hyperpigmentation on the face and upper limbs with no evidence of photosensitivity, hoarseness, small papules along the free margins of eyelids, tongue firmness with short frenulum, and widespread papular lesions of the oral cavity. Histologic and ultrastructural examination revealed the characteristic skin changes: pink, hyaline-like, strongly periodic acid-Schiff-positive material in the dermis, surrounding blood vessels, and sweat glands; thin (30 to 35 nm) collagen fibrils interspersed in abundant amorphous material; blood vessels surrounded by thickened, multilayered basement membranes, in which layers of typical, homogeneous basement membrane material were alternating with electronlucent areas filled by various amounts of thin, cross-striated fibrils, arranged perpendicularly. These findings are of great interest since they show a complex relationship between type IV and type III-like collagen components.

  16. NAD(P)H nitroblue tetrazolium reductase levels in apparently normoxic tissues: a histochemical study correlating enzyme activity with binding of radiolabelled misonidazole.

    PubMed

    Cobb, L M; Hacker, T; Nolan, J

    1990-04-01

    Hack and Helmy's method for the histochemical identification of NAD(P)H nitroblue tetrazolium reductase activity was employed to pinpoint reductase activity in certain cells in the mouse. High activity was observed in the following: lower airway epithelium, liver (centrilobular zone), eyelid (meibomian and sebaceous glands), vulval gland and parotid gland (striated cells of intralobular ducts). All of these cells had previously been identified as sites of binding of the reactive metabolites formed from the enzymic reduction of misonidazole (MISO) (Cobb et al., 1989). It had previously been thought that MISO binding would only take place in significant amounts in hypoxic tissues (tumour and possibly liver) since in normoxic tissues oxygen should reverse the initial one electron enzymic reduction, thus preventing progressive reduction to reactive species. We suggest that the very high levels of reductase in the above listed, probably normoxic, tissues contribute significantly to the accumulation of bound reactive MISO metabolite(s).

  17. Cell therapy of primary myopathies.

    PubMed

    Sampaolesi, M; Biressi, S; Tonlorenzi, R; Innocenzi, A; Draghici, E; Cusella de Angelis, M G; Cossu, G

    2005-09-01

    Mesoangioblasts are multipotent progenitors of mesodermal tissues. In vitro mesoangioblasts differentiate into many mesoderm cell types, such as smooth, cardiac and striated muscle, bone and endothelium. After transplantation mesoangioblasts colonize mostly mesoderm tissues and differentiate into many cell types of the mesoderm. When delivered through the arterial circulation, mesoangioblasts significantly restore skeletal muscle structure and function in a mouse model of muscular dystrophy. Their ability to extensively self-renew in vitro, while retaining multipotency, qualifies mesoangioblasts as a novel class of stem cells. Phenotype, properties and possible origin of mesoangioblasts are addressed in the first part of this paper. In the second part we will focus on the cell therapy approach for the treatment of Muscular Dystrophy and we will describe why mesangioblasts appear to be promising candidates for this strategy.

  18. Nitrotyrosine-modified SERCA2: a cellular sensor of reactive nitrogen species

    SciTech Connect

    Bigelow, Diana J.

    2009-01-19

    The SERCA2 isoform of the sarco/endoplasmic reticulum Ca2+-ATPase is sensitive to cellular conditions of inflammation and oxidative stress as evidenced by the common appearance of 3-nitrotyrosine modified forms of SERCA2 in aging and disease in both striated and smooth muscle of humans and several rodent models. Structural-functional studies of nitrated SERCA2 in aging heart and skeletal muscle demonstrate stoichiometric nitration of vicinal tyrosines, Tyr-294 and Tyr-295, on the lumenal side of the membrane-spanning helix, M4 that correlates with partial inhibition of its Ca2+-ATPase activity suggesting a possible regulatory function in down-regulating mitochondrial energy production and the associated generation of reactive oxygen/nitrogen species. This review discusses recent work regarding the nitrative and redox sensitivity of SERCA2 in muscle with respect to general cellular mechanisms of turnover and repair of modified proteins.

  19. Non-invasive optical modulation of local vascular permeability

    NASA Astrophysics Data System (ADS)

    Choi, Myunghwan; Choi, Chulhee

    2011-03-01

    For a systemically administered drug to act, it first needs to cross the vascular wall. This step represents a bottleneck for drug development, especially in the brain or retina, where tight junctions between endothelial cells form physiological barriers. Here, we demonstrate that femtosecond pulsed laser irradiation focused on the blood vessel wall induces transient permeabilization of plasma. Nonlinear absorption of the pulsed laser enabled the noninvasive modulation of vascular permeability with high spatial selectivity in three dimensions. By combining this method with systemic injection, we could locally deliver molecular probes in various tissues, such as brain cortex, meninges, ear, striated muscle, and bone. We suggest this method as a novel delivery tool for molecular probes or drugs.

  20. Differentiation of pluripotent stem cells to muscle fiber to model Duchenne muscular dystrophy.

    PubMed

    Chal, Jérome; Oginuma, Masayuki; Al Tanoury, Ziad; Gobert, Bénédicte; Sumara, Olga; Hick, Aurore; Bousson, Fanny; Zidouni, Yasmine; Mursch, Caroline; Moncuquet, Philippe; Tassy, Olivier; Vincent, Stéphane; Miyanari, Ayako; Bera, Agata; Garnier, Jean-Marie; Guevara, Getzabel; Hestin, Marie; Kennedy, Leif; Hayashi, Shinichiro; Drayton, Bernadette; Cherrier, Thomas; Gayraud-Morel, Barbara; Gussoni, Emanuela; Relaix, Frédéric; Tajbakhsh, Shahragim; Pourquié, Olivier

    2015-09-01

    During embryonic development, skeletal muscles arise from somites, which derive from the presomitic mesoderm (PSM). Using PSM development as a guide, we establish conditions for the differentiation of monolayer cultures of mouse embryonic stem (ES) cells into PSM-like cells without the introduction of transgenes or cell sorting. We show that primary and secondary skeletal myogenesis can be recapitulated in vitro from the PSM-like cells, providing an efficient, serum-free protocol for the generation of striated, contractile fibers from mouse and human pluripotent cells. The mouse ES cells also differentiate into Pax7(+) cells with satellite cell characteristics, including the ability to form dystrophin(+) fibers when grafted into muscles of dystrophin-deficient mdx mice, a model of Duchenne muscular dystrophy (DMD). Fibers derived from ES cells of mdx mice exhibit an abnormal branched phenotype resembling that described in vivo, thus providing an attractive model to study the origin of the pathological defects associated with DMD. PMID:26237517

  1. Contribution to the knowledge of the oribatid mite genus Aeroppia (Acari, Oribatida, Oppiidae).

    PubMed

    Ermilov, Sergey G

    2016-01-01

    Two new species of the genus Aeroppia (Oribatida, Oppiidae) are described from upper soil and leaf litter in the primary evergreen lowland rainforest in Peru. Aeroppia friedrichi sp. nov. differs from A. nasalis Mahunka, 1984 by the absence of striate ornamentation on the notogaster and notogastral setae h1, and the presence of setiform adanal setae ad1. Aeroppia longisensilla sp. nov. differs from A. adjacens Mahunka, 1985 by the smaller body size and long bothridial setae. The supplementary descriptions of Aeroppia consimilis (Banks, 1910) and A. magnipilosa (Ewing, 1909) are presented, based on material from U.S.A. A new generic diagnosis for Aeroppia is given. The taxonomic status of the subgenus Aeroppia (Paraeroppia) Sanyal, 2009 is discussed, resulting in the following taxonomic proposal: Aeroppia Hammer, 1961 (=Aeroppia (Paraeroppia) Sanyal, 2009 syn. nov.). PMID:27470768

  2. Emotional expressions modulate low α and β oscillations in a cortically blind patient.

    PubMed

    Del Zotto, Marzia; Deiber, Marie-Pierre; Legrand, Lore Billie; De Gelder, Beatrice; Pegna, Alan John

    2013-12-01

    Studies of cortical blindness have suggested that some residual visual function may persist without perceptual awareness, a condition known as blindsight. To investigate electrophysiological evidence of unconscious processing of emotional stimuli, we examined the event-related oscillations (EROs) in a 62year-old male patient (TN) with affective blindsight during random stimulation of three facial expressions (fearful, happy and neutral). Spectral power analysis in response to the different emotions revealed significant differences between fearful and happy faces over the right frontal regions at 7-8Hz (low α), and between emotional and neutral faces over the left frontal sites at 12-13Hz (low β) in a time period between 100-400ms after visual stimulus onset. These results demonstrate that emotional face processing occurs very early in time in the absence of any functional striate cortex, and further reveals the existence of specific oscillatory frequencies that reflect unconscious processing of facial expressions in affective blindsight. PMID:24144636

  3. Geometrical Origins of Contractility in Disordered Actomyosin Networks

    NASA Astrophysics Data System (ADS)

    Lenz, Martin

    2014-10-01

    Movement within eukaryotic cells largely originates from localized forces exerted by myosin motors on scaffolds of actin filaments. Although individual motors locally exert both contractile and extensile forces, large actomyosin structures at the cellular scale are overwhelmingly contractile, suggesting that the scaffold serves to favor contraction over extension. While this mechanism is well understood in highly organized striated muscle, its origin in disordered networks such as the cell cortex is unknown. Here, we develop a mathematical model of the actin scaffold's local two- or three-dimensional mechanics and identify four competing contraction mechanisms. We predict that one mechanism dominates, whereby local deformations of the actin break the balance between contraction and extension. In this mechanism, contractile forces result mostly from motors plucking the filaments transversely rather than buckling them longitudinally. These findings shed light on recent in vitro experiments and provide a new geometrical understanding of contractility in the myriad of disordered actomyosin systems found in vivo.

  4. Signaling in muscle contraction.

    PubMed

    Kuo, Ivana Y; Ehrlich, Barbara E

    2015-02-02

    Signaling pathways regulate contraction of striated (skeletal and cardiac) and smooth muscle. Although these are similar, there are striking differences in the pathways that can be attributed to the distinct functional roles of the different muscle types. Muscles contract in response to depolarization, activation of G-protein-coupled receptors and other stimuli. The actomyosin fibers responsible for contraction require an increase in the cytosolic levels of calcium, which signaling pathways induce by promoting influx from extracellular sources or release from intracellular stores. Rises in cytosolic calcium stimulate numerous downstream calcium-dependent signaling pathways, which can also regulate contraction. Alterations to the signaling pathways that initiate and sustain contraction and relaxation occur as a consequence of exercise and pathophysiological conditions.

  5. Attention-Induced Variance and Noise Correlation Reduction in Macaque V1 Is Mediated by NMDA Receptors

    PubMed Central

    Herrero, Jose L.; Gieselmann, Marc A.; Sanayei, Mehdi; Thiele, Alexander

    2013-01-01

    Summary Attention improves perception by affecting different aspects of the neuronal code. It enhances firing rates, it reduces firing rate variability and noise correlations of neurons, and it alters the strength of oscillatory activity. Attention-induced rate enhancement in striate cortex requires cholinergic mechanisms. The neuropharmacological mechanisms responsible for attention-induced variance and noise correlation reduction or those supporting changes in oscillatory activity are unknown. We show that ionotropic glutamatergic receptor activation is required for attention-induced rate variance, noise correlation, and LFP gamma power reduction in macaque V1, but not for attention-induced rate modulations. NMDA receptors mediate attention-induced variance reduction and attention-induced noise correlation reduction. Our results demonstrate that attention improves sensory processing by a variety of mechanisms that are dissociable at the receptor level. PMID:23719166

  6. [Embrionary-larval development of the tropical fish Hemirhamphus brasiliensis (Beloniformes: Hemirhamphidae) from eggs collected in the wild].

    PubMed

    Rosas, Jesús; Mata, Ernesto; Velásquez, Aidé; Cabrera, Tomas

    2008-09-01

    The embryo formation and larval development of Hemirhamphus brasiliensis Linnaeus, 1758 (Pisces: Hemirhamphidae) is described from morula stage eggs collected on Sargassum sp. Thalii in the field (10 degrees 50'55.2" N y 64 degrees 09'467" W). The eggs were spherical, 1 923.54 +/- 72.35 microm diameter with several corionic filaments, and are striated. During the first 48 h the embryo developed cephalic vesicle, miomers, and a heart located on the external body surface, beating strongly and circulating colorless blood which became pigmented red later. Before hatching, the larva developed kidney, gut tract, liver and biliar vesicle, pectoral fins, four pairs of gill arches and the mouth. The larva hatched at 114 h, the body was torpedo-shaped, yellow-green, with several dendriform melanophores; the pelvic fin was observed 72 h post hatching. At 240 hours the metamorphoses was completed. When the larvae hatched they could ingest Artemia metanauplii. PMID:19419056

  7. The effect of structural and rheological properties on blood flow distributions in capillary networks

    NASA Astrophysics Data System (ADS)

    Goldman, Daniel

    2001-11-01

    In various tissues microvascular structure, both geometric and topological, has been shown to be an important determinant of microcirculatory hemodynamics. In addition, blood rheology affects flow and hematocrit distributions in the microcirculation. Here we study steady-state hemodynamics in capillary networks modeled on the three-dimensional structure of the hamster cheek pouch retractor muscle. Capillary diameter is fixed while other structural properties are varied and an ensemble of similar random networks is generated for each parameter set. Using an experimentally derived two-phase continuum model for the flow of blood plasma and red cells, we investigate the effects of network size and topology on blood flow distributions and their variability. We also use typical capillary network structures to examine the importance of rheological effects under varying conditions. Our results indicate the relative importance of microvascular structure and blood rheology in determining the hemodynamic properties of capillary networks in striated muscle.

  8. Attention Decreases Phase-Amplitude Coupling, Enhancing Stimulus Discriminability in Cortical Area MT

    PubMed Central

    Esghaei, Moein; Daliri, Mohammad Reza; Treue, Stefan

    2015-01-01

    Local field potentials (LFPs) in cortex reflect synchronous fluctuations in the synaptic activity of local populations of neurons. The power of high frequency (>30 Hz) oscillations in LFPs is locked to the phase of low frequency (<30 Hz) oscillations, an effect known as phase-amplitude coupling (PAC). While PAC has been observed in a variety of cortical regions and animal models, its functional role particularly in primate visual cortex is largely unknown. Here, we document PAC for LFPs recorded from extra-striate area MT of macaque monkeys, an area specialized for the processing of visual motion. We further show that directing spatial attention into the receptive field of MT neurons decreases the coupling between the low frequency phase and high frequency power of LFPs. This attentional suppression of PAC increases neuronal discriminability for attended visual stimuli. Therefore, we hypothesize that visual cortex uses PAC to regulate inter-neuronal correlations and thereby enhances the coding of relevant stimuli. PMID:26733820

  9. Exploring the physiological correlates of chronic mild traumatic brain injury symptoms

    PubMed Central

    Astafiev, Serguei V.; Zinn, Kristina L.; Shulman, Gordon L.; Corbetta, Maurizio

    2016-01-01

    We report on the results of a multimodal imaging study involving behavioral assessments, evoked and resting-state BOLD fMRI, and DTI in chronic mTBI subjects. We found that larger task-evoked BOLD activity in the MT+/LO region in extra-striate visual cortex correlated with mTBI and PTSD symptoms, especially light sensitivity. Moreover, higher FA values near the left optic radiation (OR) were associated with both light sensitivity and higher BOLD activity in the MT+/LO region. The MT+/LO region was localized as a region of abnormal functional connectivity with central white matter regions previously found to have abnormal physiological signals during visual eye movement tracking (Astafiev et al., 2015). We conclude that mTBI symptoms and light sensitivity may be related to excessive responsiveness of visual cortex to sensory stimuli. This abnormal sensitivity may be related to chronic remodeling of white matter visual pathways acutely injured. PMID:26909324

  10. Endoscopic thymectomy: a neurologist’s perspective

    PubMed Central

    Melfi, Franca; Maestri, Michelangelo; De Rosa, Anna; Petsa, Afroditi; Lucchi, Marco; Mussi, Alfredo

    2016-01-01

    Myasthenia gravis (MG) is an autoimmune neuromuscular disease characterized by the presence of antibodies interacting at the neuromuscular junction (NMJ), resulting in loss of strength and severe exhaustibility of striated muscles. The abnormal production of these antibodies is triggered mainly in the thymus, and hence thymectomy in MG is considered a universally recommended treatment in order to improve the symptomatologic condition of this pathology. Currently, minimally invasive thymectomy using the Da Vinci robot system is certainly one of the most innovative techniques, performed in Pisa since 2001. This approach provides a valuable alternative to the traditional thymectomy through median sternotomy. The contribution of a neurologist is fundamental for preoperative patient selection and for the peri-operative clinical assistance in both approaches. We believe that in the robotic approach, the multidisciplinary collaboration between the neurologist, thoracic surgeon and anesthetist is important in reducing perioperative complications and ensuring a higher rate of complete remission or stable clinical improvement of MG. PMID:26904430

  11. Centimeter to Decimeter Size Spherical and Cylindrical Features in Gale Crater Sediments

    NASA Technical Reports Server (NTRS)

    Wiens, R. C.; Maurice, S.; Gasnault, O.; Clegg, S.; Fabre, C.; Nachon, M.; Rubin, D.; Goetz, W.; Mangold, N.; Schroeder, S.; Rapin, W.; Milliken, R.; Fairen, A. G.; Oehler, D.; Forni, O.; Sautter, V.; Blaney, D.; Le Moulelic, S.; Anderson, R. B.; Cousin, A.; Vasavada, A.; Grotzinger, J.

    2015-01-01

    The Curiosity rover traverse in Gale crater has explored a large series of sedimentary deposits in an ancient lake on Mars. Over the nine kilometers of traverse a recurrent observation has been southward-dipping sedimentary strata, from Shaler at the edge of Yellowknife Bay to the striated units near the Kimberley. Within the sedimentary strata cm- to decimeter- size hollow spheroidal objects and some apparent cylindrical objects have been observed. These features have not been seen by previous landed missions. The first of these were observed on sol 122 in the Gillespie Lake member at Yellowknife Bay. Additional hollow features were observed in the Point Lake outcrop in the same area. More recently a spherical and apparently hollow object, Winnipesaukee, was observed by ChemCam and Mastcam on sol 653. Here we describe the settings, morphology, and associated compositions, and we discuss possible origins of these objects.

  12. Simulation of feedback instability in the coupled magnetosphere-ionosphere system

    NASA Astrophysics Data System (ADS)

    Hasegawa, Hiroki; Ohno, Nobuaki; Sato, Tetsuya

    2010-08-01

    Quiet auroral arcs formation has been investigated theoretically and numerically in a self-consistent dynamic way. By using a three-dimensional magneto-hydro-dynamics simulation of a dipole magnetosphere-ionosphere coupling system, it is shown that multiple longitudinally striated structures of the ionospheric plasma density and the field-aligned current are formed, resulting from nonlinear feedback instability. The areas where these structures appear are consistent with the prediction by the integrated feedback theory that includes the effects of the spatially non-uniform electric field and non-uniform plasma density. Effects of the difference of the field line lengths between the ionosphere and the magnetospheric equator over the auroral latitudes are also discussed on the feedback instability.

  13. Arrangement of cytoskeletal filaments at the equator of chicken intrafusal muscle fibers.

    PubMed

    Maier, A; Zak, R

    1990-01-01

    The organization of the cytoskeleton at the equator of chicken intrafusal fibers was examined with immunofluorescence light microscopy, using monoclonal antibodies against myosin heavy chains, desmin, actin and tropomyosin. Actin was localized in the cytosol and in equatorial nuclei, while myosin heavy chains, desmin and tropomyosin were only observed in the cytosol. Although all four proteins were present at the equator and at the pole, the fluorescence produced after incubation with the different antibodies varied considerably between the two regions. Staining at the pole was in the form of striations, but at the equator it was non-striated and more uniform. The observed fluorescent patterns suggest that at the equator filaments are assembled into looser arrays than in the sarcomeres of the pole. A flexible cytoskeleton at the equator would be an appropriate substrate for distorting the affixed sensory endings during an applied stress.

  14. The dopamine theory of attention deficit hyperactivity disorder (ADHD).

    PubMed

    Levy, F

    1991-06-01

    Clinical, animal and neuroanatomical studies of differential isomer and dosage effects of CNS stimulant medications on behaviour are reviewed. Wender's hypothesis that an underlying biochemical abnormality and a disorder of reinforcement was the primary deficit in "MBD" children is restated in terms of a disorder of polysynaptic dopaminergic circuits, between prefrontal and striate centres. Wender's notion of a disorder of reinforcement is broadened to include a disorder of planning and correction of behaviour, including capacity for cortical control of automatic instinctual motor programmes. The dopamine hypothesis of Attention Deficit Hyperactivity Disorder (ADHD) is examined from the point of view of differential dose effects of CNS stimulant medications, and theories of neural control. Clinical, animal and neuropharmacological studies are reviewed. Implications of the findings for understanding clinical and side effects in ADHD children of stimulants are discussed.

  15. Role of A-type lamins in signaling, transcription, and chromatin organization

    PubMed Central

    González, José M.

    2009-01-01

    A-type lamins (lamins A and C), encoded by the LMNA gene, are major protein constituents of the mammalian nuclear lamina, a complex structure that acts as a scaffold for protein complexes that regulate nuclear structure and functions. Interest in these proteins has increased in recent years with the discovery that LMNA mutations cause a variety of human diseases termed laminopathies, including progeroid syndromes and disorders that primarily affect striated muscle, adipose, bone, and neuronal tissues. In this review, we discuss recent research supporting the concept that lamin A/C and associated nuclear envelope proteins regulate gene expression in health and disease through interplay with signal transduction pathways, transcription factors, and chromatin-associated proteins. PMID:20038676

  16. Pulmonary choriostoma in a case of tuberous sclerosis complex

    PubMed Central

    Spalgais, S; Gothi, D; Verma, AK

    2015-01-01

    A 52 years old lady was diagnosed to have Tuberous Sclerosis Complex (TSC) on the basis of 2 major and one minor criterion. She had family history of similar complaints in her sister and two sons. There was involvement of kidney in the form of angiomyolipoma, skin in the form of facial angiofibroma and teeth with a dental pit. She had an unusual lung involvement in the form of multiple small choristomas. Choristoma was diagnosed on transbronchial lung biopsy and was present in the form of disorganised striated muscles. The reported pulmonary manifestations of TCS i.e. lymphangioleiomyomatosis (LAM) and multifocal micronodular pneumocyte hyperplasia (MMPH) are types of hamartomas. Hamartomas and choristomas are both types of disorganized tissue. ‘Choristoma’of lung in TSC however is not reported. Clinopathological correlation of pulmonary hamartoma and choristoma, and treatment in TSC has been discussed. PMID:26119439

  17. [Myasthenia gravis].

    PubMed

    Schodrowski, J; Seipelt, M; Adibi-Sedeh, I; Eienbröker, C; Tackenberg, B

    2016-04-01

    Myasthenia gravis is an autoimmune disease, which leads to load-dependent weakness of voluntary skeletal muscles with recovery of function after resting. The disease is caused by autoantibodies directed against the postsynaptic nicotinic acetylcholine receptors (AChR) leading to a reduction of neuromuscular transmission. Muscles and nerves are not affected. Disorders of the thymus play a role in the pathogenesis of AChR antibody-positive myasthenia. The clinical symptoms include exercise-induced fatigue either of the ocular muscles alone (ocular myasthenia) or striated skeletal muscle and the ocular, facial and bulbar musculature (generalized myasthenia). Treatment of myasthenia gravis involves administration of acetylcholine esterase inhibitors and immunosuppressive drugs. A myasthenic crisis is characterized by life-threatening complications with severe weakness, swallowing difficulties and respiratory failure, which requires intensive care treatment. PMID:27000188

  18. A muscle stem cell for every muscle: variability of satellite cell biology among different muscle groups

    PubMed Central

    Randolph, Matthew E.; Pavlath, Grace K.

    2015-01-01

    The human body contains approximately 640 individual skeletal muscles. Despite the fact that all of these muscles are composed of striated muscle tissue, the biology of these muscles and their associated muscle stem cell populations are quite diverse. Skeletal muscles are affected differentially by various muscular dystrophies (MDs), such that certain genetic mutations specifically alter muscle function in only a subset of muscles. Additionally, defective muscle stem cells have been implicated in the pathology of some MDs. The biology of muscle stem cells varies depending on the muscles with which they are associated. Here we review the biology of skeletal muscle stem cell populations of eight different muscle groups. Understanding the biological variation of skeletal muscles and their resident stem cells could provide valuable insight into mechanisms underlying the susceptibility of certain muscles to myopathic disease. PMID:26500547

  19. Amyloids, melanins and oxidative stress in melanomagenesis.

    PubMed

    Liu-Smith, Feng; Poe, Carrie; Farmer, Patrick J; Meyskens, Frank L

    2015-03-01

    Melanoma has traditionally been viewed as an ultraviolet (UV) radiation-induced malignancy. While UV is a common inducing factor, other endogenous stresses such as metal ion accumulation or the melanin pigment itself may provide alternative pathways to melanoma progression. Eumelanosomes within melanoma often exhibit disrupted membranes and fragmented pigment which may be due to alterations in their amyloid-based striated matrix. The melanosomal amyloid can itself be toxic, especially in combination with reactive oxygen species (ROS) and reactive nitrogen species (RNS) generated by endogenous NADPH oxidase (NOX) and nitric oxide synthase (NOS) enzymes, a toxic mix that may initiate melanomagenesis. Further understanding of the loss of the melanosomal organization, the behaviour of the exposed melanin and the induction of ROS/RNS in melanomas may provide critical insights into this deadly disease.

  20. DMD mutation spectrum analysis in 613 Chinese patients with dystrophinopathy.

    PubMed

    Guo, Ruolan; Zhu, Guosheng; Zhu, Huimin; Ma, Ruiyu; Peng, Ying; Liang, Desheng; Wu, Lingqian

    2015-08-01

    Dystrophinopathy is a group of inherited diseases caused by mutations in the DMD gene. Within the dystrophinopathy spectrum, Duchenne and Becker muscular dystrophies are common X-linked recessive disorders that mainly feature striated muscle necrosis. We combined multiplex ligation-dependent probe amplification with Sanger sequencing to detect large deletions/duplications and point mutations in the DMD gene in 613 Chinese patients. A total of 571 (93.1%) patients were diagnosed, including 428 (69.8%) with large deletions/duplications and 143 (23.3%) with point mutations. Deletion/duplication breakpoints gathered mostly in introns 44-55. Reading frame rules could explain 88.6% of deletion mutations. We identified seventy novel point mutations that had not been previously reported. Spectrum expansion and genotype-phenotype analysis of DMD mutations on such a large sample size in Han Chinese population would provide new insights into the pathogenic mechanism underlying dystrophinopathies.

  1. Muscle intermediate filaments and their links to membranes and membranous organelles

    SciTech Connect

    Capetanaki, Yassemi . E-mail: ycapetanaki@bioacademy.gr; Bloch, Robert J.; Kouloumenta, Asimina; Mavroidis, Manolis; Psarras, Stelios

    2007-06-10

    Intermediate filaments (IFs) play a key role in the integration of structure and function of striated muscle, primarily by mediating mechanochemical links between the contractile apparatus and mitochondria, myonuclei, the sarcolemma and potentially the vesicle trafficking apparatus. Linkage of all these membranous structures to the contractile apparatus, mainly through the Z-disks, supports the integration and coordination of growth and energy demands of the working myocyte, not only with force transmission, but also with de novo gene expression, energy production and efficient protein and lipid trafficking and targeting. Desmin, the most abundant and intensively studied muscle intermediate filament protein, is linked to proper costamere organization, myoblast and stem cell fusion and differentiation, nuclear shape and positioning, as well as mitochondrial shape, structure, positioning and function. Similar links have been established for lysosomes and lysosome-related organelles, consistent with the presence of widespread links between IFs and membranous structures and the regulation of their fusion, morphology and stabilization necessary for cell survival.

  2. Desmin Related Disease: A Matter of Cell Survival Failure

    PubMed Central

    Capetanaki, Yassemi; Papathanasiou, Stamatis; Diokmetzidou, Antigoni; Vatsellas, Giannis; Tsikitis, Mary

    2015-01-01

    Maintenance of the highly organized striated muscle tissue requires a cell-wide dynamic network that through interactions with all vital cell structures, provides an effective mechanochemical integrator of morphology and function, absolutely necessary for intra- and intercellular coordination of all muscle functions. A good candidate for such a system is the desmin intermediate filament cytoskeletal network. Human desmin mutations and post-translational modifications cause disturbance of this network, thus leading to loss of function of both desmin and its binding partners, as well as potential toxic effects of the formed aggregates. Both loss of normal function and gain of toxic function are linked to mitochondrial defects, cardiomyocyte death, muscle degeneration and development of skeletal myopathy and cardiomyopathy. PMID:25680090

  3. Contractile Units in Disordered Actomyosin Bundles Arise from F-Actin Buckling

    NASA Astrophysics Data System (ADS)

    Lenz, Martin; Thoresen, Todd; Gardel, Margaret L.; Dinner, Aaron R.

    2012-06-01

    Bundles of filaments and motors are central to contractility in cells. The classic example is striated muscle, where actomyosin contractility is mediated by highly organized sarcomeres which act as fundamental contractile units. However, many contractile bundles in vivo and in vitro lack sarcomeric organization. Here we propose a model for how contractility can arise in bundles without sarcomeric organization and validate its predictions with experiments on a reconstituted system. In the model, internal stresses in frustrated arrangements of motors with diverse velocities cause filaments to buckle, leading to overall shortening. We describe the onset of buckling in the presence of stochastic motor head detachment and predict that buckling-induced contraction occurs in an intermediate range of motor densities. We then calculate the size of the “contractile units” associated with this process. Consistent with these results, our reconstituted actomyosin bundles show contraction at relatively high motor density, and we observe buckling at the predicted length scale.

  4. Biology of MET: a double life between normal tissue repair and tumor progression

    PubMed Central

    2015-01-01

    MNNG HOS transforming gene (MET) is a class IV receptor tyrosine kinase, expressed on the surface of epithelial cells. The interaction with the hepatocyte grow factor (HGF) induces MET dimerization and the activation of multiple intracellular pathways leading to cell proliferation, anti-apoptosis, morphogenic differentiation, motility, invasion, and angiogenesis. Knock out mice have demonstrated that MET is necessary for normal embryogenesis including the formation of striate muscles, liver and trophoblastic structures. The overexpression of MET and HGF are common in solid tumors and contribute to determine their growth. Indeed, MET has been cloned as a transforming gene from a chemically induced human osteosarcoma cell line and therefore is considered a proto-oncogene. Germline MET mutations are characteristic of hereditary papillary kidney cancers and MET amplification is observed in tumors including lung and gastric adenocarcinomas. The inhibition of MET signaling is the target for specific drugs that are raising exciting expectation for medical treatment of cancer. PMID:25992381

  5. Viremia in young herons and ibis infected with Venezuelan encephalitis virus.

    PubMed

    Dickerman, R W; Bonacorsa, C M; Scherer, W F

    1976-12-01

    Fifty-seven of 61 nestling, 8- to 30-day-old herons of three species (Black-crowned Night Heron, Great Egret, and Snowy Egret), developed viremia lasting one to three days following subcutaneous inoculation with small doses of endemic or epidemic strains of Venezuelan encephalitis virus from Mexico, Guatemala or Venezuela. Two epidemic strains from Guatemala or Venezuela stimulated levels of viremia similar to those following infection with enzootic strains. Great Egrets, Striated and Boat-billed Herons and Scarlet Ibis older than 30 days of age developed viremias of lower levels and shorter durtions than did young birds. Marked differences in levles of viremia were not observed among Black-crowned Night Herons, Great Egrets, or Snowy Egrets. Over 50% of viremic blood samples from herons 8-30 days of age contained 1000 or more chick embryo cell culture plaque forming units of Venezuelan encephalitis per ml, levels sufficient to infect some vector species mosquitoes.

  6. Surgical anatomy of the retroperitoneal spaces, Part V: Surgical applications and complications.

    PubMed

    Mirilas, Petros; Skandalakis, John E

    2010-04-01

    Knowledge of the surgical anatomy of the retroperitoneum is crucial for surgery of the retroperitoneal organs. Surgery is essential for treatment of retroperitoneal pathologies. The list of these diseases is extensive and comprises acute and chronic inflammatory processes (abscess, injury, hematoma, idiopathic fibrosis), metastatic neoplasms, and primary neoplasms from fibroadipose tissue, connective tissue, smooth and striated muscle, vascular tissue, somatic and sympathetic nervous tissue, extraadrenal chromaffin tissue, and lymphatic tissue. The retroperitoneum can be approached and explored by several routes, including the transperitoneal route and the extraperitoneal route. The retroperitoneal approach to the iliac fossa is used for ectopic renal transplantation. Safe and reliable primary retroperitoneal access can be performed for laparoscopic exploration. The anatomic complications of retroperitoneal surgery are the complications of the organs located in several compartments of the retroperitoneal space. Complications may arise from incisions to the somatic wall, somatic nerves, blood and lymphatic vessels, lymph nodes, visceral autonomous plexuses, and neighboring splanchna.

  7. Attention Decreases Phase-Amplitude Coupling, Enhancing Stimulus Discriminability in Cortical Area MT.

    PubMed

    Esghaei, Moein; Daliri, Mohammad Reza; Treue, Stefan

    2015-01-01

    Local field potentials (LFPs) in cortex reflect synchronous fluctuations in the synaptic activity of local populations of neurons. The power of high frequency (>30 Hz) oscillations in LFPs is locked to the phase of low frequency (<30 Hz) oscillations, an effect known as phase-amplitude coupling (PAC). While PAC has been observed in a variety of cortical regions and animal models, its functional role particularly in primate visual cortex is largely unknown. Here, we document PAC for LFPs recorded from extra-striate area MT of macaque monkeys, an area specialized for the processing of visual motion. We further show that directing spatial attention into the receptive field of MT neurons decreases the coupling between the low frequency phase and high frequency power of LFPs. This attentional suppression of PAC increases neuronal discriminability for attended visual stimuli. Therefore, we hypothesize that visual cortex uses PAC to regulate inter-neuronal correlations and thereby enhances the coding of relevant stimuli. PMID:26733820

  8. An optical image segmentor using neural based wavelet filtering techniques

    NASA Astrophysics Data System (ADS)

    Veronin, Christopher P.; Rogers, Steven K.; Kabrisky, Matthew; Priddy, Kevin L.; Ayer, Kevin W.

    1991-10-01

    This paper presents a neural based optical image segmentation scheme for locating potential targets in cluttered FLIR images. The advantage of such a scheme is speed, i.e., the speed of light. Such a design is critical to achieve real-time segmentation and classification for machine vision applications. The segmentation scheme used was based on texture discrimination and employed biologically based orientation specific filters (wavelet filters) as its main component. These filters are well understood impulse response functions of mammalian vision systems from input to striate cortex. By using the proper choice of aperture pair separation, dilation, and orientation, targets in FLIR imagery were optically segmented. Wavelet filtering is illustrated for glass template slides, as well as segmentation for static and real-time FLIR imagery displayed on a liquid crystal television.

  9. Optical image segmentation using neural-based wavelet filtering techniques

    NASA Astrophysics Data System (ADS)

    Veronin, Christopher P.; Priddy, Kevin L.; Rogers, Steven K.; Ayer, Kevin W.; Kabrisky, Matthew; Welsh, Byron M.

    1992-02-01

    This paper presents a neural based optical image segmentation scheme for locating potential targets in cluttered FLIR images. The advantage of such a scheme is speed, i.e., the speed of light. Such a design is critical to achieve real-time segmentation and classification for machine vision applications. The segmentation scheme used was based on texture discrimination and employed biologically based orientation specific filters (wavelet filters) as its main component. These filters are well understood impulse response functions of mammalian vision systems from input to striate cortex. By using the proper choice of aperture pair separation, dilation, and orientation, targets in FLIR imagery were optically segmented. Wavelet filtering is illustrated for glass template slides, as well as segmentation for static and real-time FLIR imagery displayed on a liquid crystal television.

  10. Skeletal muscle atrophy and the E3 ubiquitin ligases MuRF1 and MAFbx/atrogin-1

    PubMed Central

    Baehr, Leslie M.

    2014-01-01

    Muscle RING finger 1 (MuRF1) and muscle atrophy F-box (MAFbx)/atrogin-1 were identified more than 10 years ago as two muscle-specific E3 ubiquitin ligases that are increased transcriptionally in skeletal muscle under atrophy-inducing conditions, making them excellent markers of muscle atrophy. In the past 10 years much has been published about MuRF1 and MAFbx with respect to their mRNA expression patterns under atrophy-inducing conditions, their transcriptional regulation, and their putative substrates. However, much remains to be learned about the physiological role of both genes in the regulation of mass and other cellular functions in striated muscle. Although both MuRF1 and MAFbx are enriched in skeletal, cardiac, and smooth muscle, this review will focus on the current understanding of MuRF1 and MAFbx in skeletal muscle, highlighting the critical questions that remain to be answered. PMID:25096180

  11. Sarcolemmal ATP-sensitive K(+) channels control energy expenditure determining body weight.

    PubMed

    Alekseev, Alexey E; Reyes, Santiago; Yamada, Satsuki; Hodgson-Zingman, Denice M; Sattiraju, Srinivasan; Zhu, Zhiyong; Sierra, Ana; Gerbin, Marina; Coetzee, William A; Goldhamer, David J; Terzic, Andre; Zingman, Leonid V

    2010-01-01

    Metabolic processes that regulate muscle energy use are major determinants of bodily energy balance. Here, we find that sarcolemmal ATP-sensitive K(+) (K(ATP)) channels, which couple membrane excitability with cellular metabolic pathways, set muscle energy expenditure under physiological stimuli. Disruption of K(ATP) channel function provoked, under conditions of unaltered locomotor activity and blood substrate availability, an extra energy cost of cardiac and skeletal muscle performance. Inefficient fuel metabolism in K(ATP) channel-deficient striated muscles reduced glycogen and fat body depots, promoting a lean phenotype. The propensity to lesser body weight imposed by K(ATP) channel deficit persisted under a high-fat diet, yet obesity restriction was achieved at the cost of compromised physical endurance. Thus, sarcolemmal K(ATP) channels govern muscle energy economy, and their downregulation in a tissue-specific manner could present an antiobesity strategy by rendering muscle increasingly thermogenic at rest and less fuel efficient during exercise.

  12. Targeting Mitogen-Activated Protein Kinase Signaling in Mouse Models of Cardiomyopathy Caused by Lamin A/C Gene Mutations.

    PubMed

    Muchir, Antoine; Worman, Howard J

    2016-01-01

    The most frequently occurring mutations in the gene encoding nuclear lamin A and nuclear lamin C cause striated muscle diseases virtually always involving the heart. In this review, we describe the approaches and methods used to discover that cardiomyopathy-causing lamin A/C gene mutations increase MAP kinase signaling in the heart and that this plays a role in disease pathogenesis. We review different mouse models of cardiomyopathy caused by lamin A/C gene mutations and how transcriptomic analysis of one model identified increased cardiac activity of the ERK1/2, JNK, and p38α MAP kinases. We describe methods used to measure the activity of these MAP kinases in mouse hearts and then discuss preclinical treatment protocols using pharmacological inhibitors to demonstrate their role in pathogenesis. Several of these kinase inhibitors are in clinical development and could potentially be used to treat human subjects with cardiomyopathy caused by lamin A/C gene mutations.

  13. Pathology of eyelid tumors

    PubMed Central

    Pe’er, Jacob

    2016-01-01

    The eyelids are composed of four layers: skin and subcutaneous tissue including its adnexa, striated muscle, tarsus with the meibomian glands, and the palpebral conjunctiva. Benign and malignant tumors can arise from each of the eyelid layers. Most eyelid tumors are of cutaneous origin, mostly epidermal, which can be divided into epithelial and melanocytic tumors. Benign epithelial lesions, cystic lesions, and benign melanocytic lesions are very common. The most common malignant eyelid tumors are basal cell carcinoma in Caucasians and sebaceous gland carcinoma in Asians. Adnexal and stromal tumors are less frequent. The present review describes the more important eyelid tumors according to the following groups: Benign and malignant epithelial tumors, benign and malignant melanocytic tumors, benign and malignant adnexal tumors, stromal eyelid tumors, lymphoproliferative and metastatic tumors, other rare eyelid tumors, and inflammatory and infections lesions that simulate neoplasms. PMID:27146927

  14. Mid-Pleistocene cosmogenic minimum-age limits for pre-Wisconsinan glacial surfaces in southwestern Minnesota and southern Baffin Island: a multiple nuclide approach

    NASA Astrophysics Data System (ADS)

    Bierman, Paul R.; Marsella, Kimberly A.; Patterson, Carrie; Davis, P. Thompson; Caffee, Marc

    1999-02-01

    Paired 10Be and 26Al analyses ( n=14) indicate that pre-Wisconsinan, glaciated bedrock surfaces near the northern (Baffin Island) and southern (Minnesota) paleo-margins of the Laurentide Ice Sheet have long and complex histories of cosmic-ray exposure, including significant periods of partial or complete shielding from cosmic rays. Using the ratio, 26Al/ 10Be, we calculate that striated outcrops of Sioux Quartzite in southwestern Minnesota (southern margin) were last overrun by ice at least 500,000 years ago. Weathered bedrock tors on the once-glaciated uplands of Baffin Island (northern margin) are eroding no faster than 1.1 m Myr -1, the equivalent of at least 450,000 years of surface and near-surface exposure. Our data demonstrate that exposure ages and erosion rates calculated from single nuclides can underestimate surface stability dramatically because any intermittent burial, and the resultant lowering of nuclide production rates and nuclide abundances, will remain undetected.

  15. Sacral nerve stimulation.

    PubMed

    Matzel, K E; Stadelmaier, U; Besendörfer, M

    2004-01-01

    The current concept of recruiting residual function of an inadequate pelvic organ by electrostimulation involves stimulation of the sacral spinal nerves at the level of the sacral canal. The rationale for applying SNS to fecal incontinence was based on clinical observations of its effect on bowel habits and anorectal continence function in urologic patients (increased anorectal angulation and anal canal closure pressure) and on anatomic considerations: dissection demonstrated a dual peripheral nerve supply of the striated pelvic floor muscles that govern these functions. Because the sacral spinal nerve site is the most distal common location of this dual nerve supply, stimulating here can elicit both functions. Since the first application of SNS in fecal incontinence in 1994, this technique has been improved, the patient selection process modified, and the spectrum of indications expanded. At present SNS has been applied in more than 1300 patients with fecal incontinence limited.

  16. Paleozoic diamictites in the Peruvian Altiplano: evidence and tectonic implications

    NASA Astrophysics Data System (ADS)

    Díaz-Martínez, Enrique; Acosta, Harmuth; Cardenas, José; Carlotto, Víctor; Rodríguez, Rildo

    2001-11-01

    Striated and faceted clasts found within the diamictites of the San Gabán Formation immediately north of Ayaviri (southeast Peru) are interpreted as evidence for the late Ashgill-Llandovery glaciations in the Peruvian Altiplano, an area where this unit was previously considered not to be deposited. The Lower Paleozoic stratigraphic sequence cropping out in the area includes the Sandia, San Gabán, and Ananea Formations, and thus belongs to the Eastern Cordillera tectonostratigraphic domain, but within the Altiplano morphotectonic region. The marked difference between the Lower Paleozoic sequences of the Altiplano and Eastern Cordillera tectonostratigraphic domains suggests important tectonic shortening along the boundary fault zone during Andean Cenozoic deformation.

  17. Molecular mechanisms responsible for alcohol-induced myopathy in skeletal muscle and heart.

    PubMed

    Lang, Charles H; Frost, Robert A; Summer, Andrew D; Vary, Thomas C

    2005-10-01

    Chronic alcohol abuse has the potential to modulate striated muscle physiology and function. The skeletal muscle alcoholic myopathy is characterized by muscle weakness and difficulties in gait and locomotion, while chronic alcohol consumption ultimately leads to a decrease in cardiac contractility and output. In both tissues a loss of protein mass results in part from a decreased protein synthesis that initially manifests as a defect in translational efficiency. This review focuses on recent developments in understanding the cellular and molecular mechanisms by which alcohol impairs mRNA translation in skeletal and cardiac muscle, including identification of the signaling pathways and biochemical sites negatively impacted. Defective signaling potentially results from resistance to the normal stimulating effects of anabolic hormones (insulin and insulin-like growth factor-I) and nutrients (leucine) as well as increased production of several negative regulators of muscle mass. Overall, the biochemical mechanisms contributing to the pathogenesis of loss of skeletal and cardiac muscle are reviewed.

  18. General tissue characteristics of the lower urethral and vaginal walls in the domestic rabbit.

    PubMed

    Rodríguez-Antolín, Jorge; Xelhuantzi, Nicté; García-Lorenzana, Mario; Cuevas, Estela; Hudson, Robyn; Martínez-Gómez, Margarita

    2009-01-01

    In European rabbits, the distal urethra (DU) opens into the anterior pelvic vagina forming a single canal by which females copulate, give birth, and urinate. We investigated whether the histological characteristics of the DU and the pelvic and perineal vagina are different. The DU and vagina of rabbits (Oryctolagus cuniculus) were cut and stained with hematoxylin-eosin and Masson's trichrome (n = 3). Data were compared by using Friedman's ANOVA for repeated measures. The walls of the DU and vagina are composed of mucosa, submucosa, smooth muscle, and an external layer. Differences in tissue characteristics of the mucosa, orientation of the smooth muscle fibers, components of the external layer (connective tissue, blood vessels, and striated musculature), and thickness of the tissue layers were found among regions. The lack of histological homogeneity along the urethra and vagina possibly reflects differences in the functions of each segment.

  19. The Structure and Regulation of Human Muscle α-Actinin

    PubMed Central

    Ribeiro, Euripedes de Almeida; Pinotsis, Nikos; Ghisleni, Andrea; Salmazo, Anita; Konarev, Petr V.; Kostan, Julius; Sjöblom, Björn; Schreiner, Claudia; Polyansky, Anton A.; Gkougkoulia, Eirini A.; Holt, Mark R.; Aachmann, Finn L.; Žagrović, Bojan; Bordignon, Enrica; Pirker, Katharina F.; Svergun, Dmitri I.; Gautel, Mathias; Djinović-Carugo, Kristina

    2014-01-01

    Summary The spectrin superfamily of proteins plays key roles in assembling the actin cytoskeleton in various cell types, crosslinks actin filaments, and acts as scaffolds for the assembly of large protein complexes involved in structural integrity and mechanosensation, as well as cell signaling. α-actinins in particular are the major actin crosslinkers in muscle Z-disks, focal adhesions, and actin stress fibers. We report a complete high-resolution structure of the 200 kDa α-actinin-2 dimer from striated muscle and explore its functional implications on the biochemical and cellular level. The structure provides insight into the phosphoinositide-based mechanism controlling its interaction with sarcomeric proteins such as titin, lays a foundation for studying the impact of pathogenic mutations at molecular resolution, and is likely to be broadly relevant for the regulation of spectrin-like proteins. PMID:25433700

  20. Water-tunnel experiments on an oscillating airfoil at RE equals 21,000

    NASA Technical Reports Server (NTRS)

    Mcalister, K. W.; Carr, L. W.

    1978-01-01

    Flow visualization experiments were performed in a water tunnel on a modified NACA 0012 airfoil undergoing large amplitude harmonic oscillations in pitch. Hydrogen bubbles were used to: (1) create a conveniently striated and well preserved set of inviscid flow markers; and (2) to expose the succession of events occurring within the viscous domain during the onset of dynamic stall. Unsteady effects were shown to have an important influence on the progression of flow reversal along the airfoil surface prior to stall. A region of reversed flow underlying a free shear layer was found to momentarily exist over the entire upper surface without any appreciable disturbance of the viscous-inviscid boundary. A flow protuberance was observed to develop near the leading edge, while minor vortices evolve from an expanding instability of the free shear layer over the rear portion of the airfoil. The complete breakdown of this shear layer culminates in the successive formation of two dominant vortices.

  1. A new Lower Triassic ichthyopterygian assemblage from Fossil Hill, Nevada

    PubMed Central

    Motani, Ryosuke; Embree, Patrick; Orchard, Michael J.

    2016-01-01

    We report a new ichthyopterygian assemblage from Lower Triassic horizons of the Prida Formation at Fossil Hill in central Nevada. Although fragmentary, the specimens collected so far document a diverse fauna. One partial jaw exhibits isodont dentition with blunt tipped, mesiodistally compressed crowns and striated enamel. These features are shared with the Early Triassic genus Utatsusaurus known from coeval deposits in Japan and British Columbia. An additional specimen exhibits a different dentition characterized by relatively small, rounded posterior teeth resembling other Early Triassic ichthyopterygians, particularly Grippia. This Nevada assemblage marks a southward latitudinal extension for Early Triassic ichthyopterygians along the eastern margin of Panthalassa and indicates repeated trans-hemispheric dispersal events in Early Triassic ichthyopterygians. PMID:26855868

  2. YAP-Mediated Mechanotransduction in Skeletal Muscle

    PubMed Central

    Fischer, Martina; Rikeit, Paul; Knaus, Petra; Coirault, Catherine

    2016-01-01

    Skeletal muscle is not only translating chemical energy into mechanical work, it is also a highly adaptive and regenerative tissue whose architecture and functionality is determined by its mechanical and physical environment. Processing intra- and extracellular mechanical signaling cues contributes to the regulation of cell growth, survival, migration and differentiation. Yes-associated Protein (YAP), a transcriptional coactivator downstream of the Hippo pathway and its paralog, the transcriptional co-activator with PDZ-binding motif (TAZ), were recently found to play a key role in mechanotransduction in various tissues including skeletal muscle. Furthermore, YAP/TAZ modulate myogenesis and muscle regeneration and abnormal YAP activity has been reported in muscular dystrophy and rhabdomyosarcoma. Here, we summarize the current knowledge of mechanosensing and -signaling in striated muscle. We highlight the role of YAP signaling and discuss the different routes and hypotheses of its regulation in the context of mechanotransduction. PMID:26909043

  3. Chorea associated with anti-phospholipid antibodies: case report.

    PubMed

    Demonty, J; Gonce, M; Ribai, P; Verellen-Dumoulin, C; Hustinx, R

    2010-01-01

    A seventeen year-old boy developed left sided chorea in a few days, subsequently involving the four limbs. Although he presented a marfanoid phenotype, genetic analysis of the Fibrillin 1 was normal. The genes for familial chorea and Huntington's disease were also negative. Biological tests showed normal serum homocystein, but revealed very high levels of anti-beta2-GP1 IgG, anticardiolipin and lupus anticoagulant, which remained at similar values for a period of over three months. Electroencephalogram and cerebral magnetic resonance imaging (MRI) showed no abnormalities. Brain PET-scan disclosed bilateral striatal hypermetabolism. The patient was treated with methylprednisolone and low dose of acetylsalicylic acid. He improved markedly after six weeks of treatment, and choreic movements disappeared completely after two months. A control PET-scan performed at this time showed reversion of striated hypermetabolism to a normal pattern. The pathogenic aspects of this relatively rare case of chorea are discussed. PMID:21128564

  4. Titin, a Central Mediator for Hypertrophic Signaling, Exercise-Induced Mechanosignaling and Skeletal Muscle Remodeling

    PubMed Central

    Krüger, Martina; Kötter, Sebastian

    2016-01-01

    Titin is a giant scaffold protein with multiple functions in striated muscle physiology. Due to the elastic I-band domains and the filament-like integration in the half-sarcomere titin is an important factor for sarcomere assembly and serves as an adaptable molecular spring that determines myofilament distensibility. Protein-interactions e.g., with muscle ankyrin repeat proteins or muscle LIM-protein link titin to hypertrophic signaling and via p62 and Muscle Ring Finger proteins to mechanisms that control protein quality control. This review summarizes our current knowledge on titin as a central node for exercise-induced mechanosignaling and remodeling and further highlights the pathophysiological implications. PMID:26973541

  5. Dracunculus brasiliensis sp. n. (Nematoda: Dracunculidae) from the anaconda, Eunectes murinus (Ophidia: Boidae).

    PubMed

    Moravec, F; Santos, C P

    2009-02-01

    Dracunculus brasiliensis sp. n. (Dracunculidae), is described based on a single female specimen found in the body cavity of the anaconda, Eunectes murinus (L.) (Ophidia: Boidae), from the Mexiana Island, Amazon River delta, Brazil and one female previously recorded from the subcutaneous tissue of this host species imported from South America into Europe (ZOO in the Czech Republic). The new species is characterised mainly by markedly large, anteriorly protruding dorsal and ventral double papillae of the internal circle and small lateral papillae of the same circle, a widely rounded caudal end, the excretory pore situated just posterior to the nerve ring, a distinctly transversely striated cuticle and by the length (396-429 mum) of larvae from uterus. This is the first species of Dracunculus described from reptiles in South America.

  6. Snake velvet black: Hierarchical micro- and nanostructure enhances dark colouration in Bitis rhinoceros

    PubMed Central

    Spinner, Marlene; Kovalev, Alexander; Gorb, Stanislav N.; Westhoff, Guido

    2013-01-01

    The West African Gaboon viper (Bitis rhinoceros) is a master of camouflage due to its colouration pattern. Its skin is geometrically patterned and features black spots that purport an exceptional spatial depth due to their velvety surface texture. Our study shades light on micromorphology, optical characteristics and principles behind such a velvet black appearance. We revealed a unique hierarchical pattern of leaf-like microstructures striated with nanoridges on the snake scales that coincides with the distribution of black colouration. Velvet black sites demonstrate four times lower reflectance and higher absorbance than other scales in the UV – near IR spectral range. The combination of surface structures impeding reflectance and absorbing dark pigments, deposited in the skin material, provides reflecting less than 11% of the light reflected by a polytetrafluoroethylene diffuse reflectance standard in any direction. A view-angle independent black structural colour in snakes is reported here for the first time. PMID:23677278

  7. The Dystrophin Complex: structure, function and implications for therapy

    PubMed Central

    Gao, Quan; McNally, Elizabeth M

    2016-01-01

    The dystrophin complex stabilizes the plasma membrane of striated muscle cells. Loss of function mutations in the genes encoding dystrophin, or the associated proteins, triggers instability of the plasma membrane and myofiber loss. Mutations in dystrophin have been extensively cataloged providing remarkable structure-function correlation between predicted protein structure and clinical outcomes. These data have highlighted dystrophin regions necessary for in vivo function and fueled the design of viral vectors and now, exon skipping approaches for use in dystrophin restoration therapies. However, dystrophin restoration is likely more complex, owing to the role of the dystrophin complex as a broad cytoskeletal integrator. This review will focus on dystrophin restoration, with emphasis on the regions of dystrophin essential for interacting with its associated proteins and discuss the structural implications of these approaches. PMID:26140716

  8. A novel monoclonal antibody that binds to hemocytes from shrimps and oysters.

    PubMed

    Seibert, Caroline H; Gargioni, Rogério; Rosa, Rafael D; Perazzolo, Luciane M; Nazari, Evelise M; Ammar, Dib; Zanetti, Carlos R; Pinto, Aguinaldo R

    2010-04-01

    The monoclonal antibody (MAb) LITO-1 was produced from a stable hybridoma cell line generated by the fusion of NS1 myeloma cells with spleen cells isolated from Balb/c mice immunized with a paraformaldehyde-fixed hemocyte suspension of Litopenaeus vannamei. This MAb reacted with all three hemocyte subtypes, but no reaction was observed with components of plasma. Immunohistochemistry assays demonstrated that LITO-1 was very effective in specifically distinguishing hemocytes infiltrated in several tissues such as striated muscle, brain, and hepatopancreas. Moreover, this antibody was able to recognize hemocytes from two shrimp species, Litopenaeus schmitti and Farfantepenaeus paulensis, as well as hemocytes of the oyster Crassostrea gigas. No reaction was observed against hemocytes from the terrestrial insect Triatoma klugi or with mammalian RAW cells. This novel MAb can be useful in revealing the presence and function of a conservative epitope in hemocytes of marine crustaceans and mollusks.

  9. Probing the 3D structure of cornea-like collagen liquid crystals with polarization-resolved SHG microscopy.

    PubMed

    Teulon, Claire; Tidu, Aurélien; Portier, François; Mosser, Gervaise; Schanne-Klein, Marie-Claire

    2016-07-11

    This work aims at characterizing the three-dimensional organization of liquid crystals composed of collagen, in order to determine the physico-chemical conditions leading to highly organized structures found in biological tissues such as cornea. To that end, we use second-harmonic generation (SHG) microscopy, since aligned collagen structures have been shown to exhibit intrinsic SHG signals. We combine polarization-resolved SHG experiments (P-SHG) with the theoretical derivation of the SHG signal of collagen molecules tilted with respect to the focal plane. Our P-SHG images exhibit striated patterns with variable contrast, as expected from our analytical and numerical calculations for plywood-like nematic structures similar to the ones found in the cornea. This study demonstrates the benefits of P-SHG microscopy for in situ characterization of highly organized biopolymers at micrometer scale, and the unique sensitivity of this nonlinear optical technique to the orientation of collagen molecules. PMID:27410876

  10. Novel large deletion in the ACTA1 gene in a child with autosomal recessive nemaline myopathy.

    PubMed

    Friedman, Bethany; Simpson, Kara; Tesi-Rocha, Carolina; Zhou, Delu; Palmer, Cheryl A; Suchy, Sharon F

    2014-04-01

    Nemaline myopathy (NM) is a genetically and clinically heterogeneous disorder resulting from a disruption of the thin filament proteins of the striated muscle sarcomere. The disorder is typically characterized by muscle weakness including the face, neck, respiratory, and limb muscles and is clinically classified based on the age of onset and severity. Mutations in the ACTA1 gene contribute to a significant proportion of NM cases. The majority of ACTA1 gene mutations are missense mutations causing autosomal dominant NM by producing an abnormal protein. However, approximately 10% of ACTA1 gene mutations are associated with autosomal recessive NM; these mutations are associated with loss of protein function. We report the first case of a large deletion in the ACTA1 gene contributing to autosomal recessive NM. This case illustrates the importance of understanding disease mechanisms at the molecular level to accurately infer the inheritance pattern and potentially aid with clinical management. PMID:24447884

  11. The prelamin A pre-peptide induces cardiac and skeletal myoblast differentiation

    SciTech Connect

    Brodsky, Gary L. . E-mail: Gary.Brodsky@uchsc.edu; Bowersox, Jeffrey A.; Fitzgerald-Miller, Lisa; Miller, Leslie A.; Maclean, Kenneth N.

    2007-05-18

    Prelamin A processing is unique amongst mammalian proteins and results in the production of a farnesylated and carboxymethylated peptide. We examined the effect of pathogenic LMNA mutations on prelamin A processing, and of the covalently modified peptide on cardiac and skeletal myoblast differentiation. Here we report a mutation associated with dilated cardiomyopathy prevents prelamin A peptide production. In addition, topical application of the covalently modified C-terminal peptide to proliferating skeletal and cardiac myoblasts induced myotube and striated tissue formation, respectively. Western blot analysis revealed that skeletal and cardiac myoblasts are the first cell lines examined to contain unprocessed prelamin A, and immunostaining of peptide-treated cells revealed a previously unidentified role for prelamin A in cytoskeleton formation and intercellular organization. These results demonstrate a direct role for prelamin A in myoblast differentiation and indicate the prelamin A peptide may have therapeutic potential.

  12. Pathology of eyelid tumors.

    PubMed

    Pe'er, Jacob

    2016-03-01

    The eyelids are composed of four layers: skin and subcutaneous tissue including its adnexa, striated muscle, tarsus with the meibomian glands, and the palpebral conjunctiva. Benign and malignant tumors can arise from each of the eyelid layers. Most eyelid tumors are of cutaneous origin, mostly epidermal, which can be divided into epithelial and melanocytic tumors. Benign epithelial lesions, cystic lesions, and benign melanocytic lesions are very common. The most common malignant eyelid tumors are basal cell carcinoma in Caucasians and sebaceous gland carcinoma in Asians. Adnexal and stromal tumors are less frequent. The present review describes the more important eyelid tumors according to the following groups: Benign and malignant epithelial tumors, benign and malignant melanocytic tumors, benign and malignant adnexal tumors, stromal eyelid tumors, lymphoproliferative and metastatic tumors, other rare eyelid tumors, and inflammatory and infections lesions that simulate neoplasms. PMID:27146927

  13. Pseudotumoral hemicerebellitis as a mimicker of Lhermitte-Duclos disease in children: does neuroimaging help to differentiate them?

    PubMed

    Bosemani, Thangamadhan; Steinlin, Maja; Toelle, Sandra P; Beck, Jürgen; Boltshauser, Eugen; Huisman, Thierry A G M; Poretti, Andrea

    2016-05-01

    The clinical presentation and neuroimaging findings of children with pseudotumoral hemicerebellitis (PTHC) and Lhermitte-Duclos disease (LDD) may be very similar. The differentiation between these entities, however, is important because their management and prognosis are different. We report on three children with PTHC. For all three children, in the acute situation, the differentiation between PTHC and LDD was challenging. A review of the literature shows that a detailed evaluation of conventional and neuroimaging data may help to differentiate between these two entities. A striated folial pattern, brainstem involvement, and prominent veins surrounding the thickened cerebellar foliae on susceptibility weighted imaging favor LDD, while post-contrast enhancement and an increased choline peak on (1)H-Magnetic resonance spectroscopy suggest PTHC.

  14. Investigation of passive atmospheric sounding using millimeter and submillimeter wavelength channels

    NASA Technical Reports Server (NTRS)

    Gasiewski, Albin J.

    1993-01-01

    Presented in this study are the results of controlled partially polarimetric measurements of thermal emission at 91.65 GHz from a striated water surface as corroborated by a geometrical optics radiative model. The measurements were obtained outdoors using a precision polarimetric radiometer which directly measured the first three modified Stokes' parameters. Significant variations in these parameters as a function of azimuthal water wave angle were found, with peak-to-peak variations in T(sub u) of up to approximately 10 K. The measurements are well corroborated by the GO model over a range of observations angles from near nadir up to approximately 65 degrees from nadir. The model incorporates both multiple scattering and a realistic downwelling background brightness field.

  15. Neural consequences of competing stimuli in both visual hemifields: a physiological basis for visual extinction.

    PubMed

    Fink, G R; Driver, J; Rorden, C; Baldeweg, T; Dolan, R J

    2000-04-01

    We used positron emission tomography in healthy volunteers to test hemispheric rivalry theories for normal and pathological spatial attention, which provide an influential account of contralesional extinction on bilateral stimulation after unilateral brain injury. Subjects reported visual characters presented either unilaterally or bilaterally. An extinction-like pattern was found behaviorally, with characters in one hemifield reported less accurately when competing characters appeared in the other hemifield. Differences in neural activity for unilateral minus bilateral conditions revealed greater activation of striate and extrastriate areas for stimuli presented without competing stimuli in the other hemifield. Thus, simultaneous bilateral stimulation led to a significant reduction in response by spatiotopic visual cortex contralateral to a particular stimulus. These data provide physiological support for interhemispheric rivalry in the intact human brain, and demonstrate that such competition impacts at early levels of perceptual processing.

  16. Mid-Pleistocene cosmogenic minimum-age limits for pre-Wisconsinan glacial surfaces in southwestern Minnesota and southern Baffin Island: A multiple nuclide approach

    USGS Publications Warehouse

    Bierman, P.R.; Marsella, K.A.; Patterson, Chris; Davis, P.T.; Caffee, M.

    1999-01-01

    Paired 10Be and 26Al analyses (n = 14) indicate that pre-Wisconsinan, glaciated bedrock surfaces near the northern (Baffin Island) and southern (Minnesota) paleo-margins of the Laurentide Ice Sheet have long and complex histories of cosmic-ray exposure, including significant periods of partial or complete shielding from cosmic rays. Using the ratio, 26Al/10Be, we calculate that striated outcrops of Sioux Quartzite in southwestern Minnesota (southern margin) were last overrun by ice at least 500,000 years ago. Weathered bedrock tors on the once-glaciated uplands of Baffin Island (northern margin) are eroding no faster than 1.1 m Myr-1, the equivalent of at least 450,000 years of surface and near-surface exposure. Our data demonstrate that exposure ages and erosion rates calculated from single nuclides can underestimate surface stability dramatically because any intermittent burial, and the resultant lowering of nuclide production rates and nuclide abundances, will remain undetected.

  17. Pseudotumoral hemicerebellitis as a mimicker of Lhermitte-Duclos disease in children: does neuroimaging help to differentiate them?

    PubMed

    Bosemani, Thangamadhan; Steinlin, Maja; Toelle, Sandra P; Beck, Jürgen; Boltshauser, Eugen; Huisman, Thierry A G M; Poretti, Andrea

    2016-05-01

    The clinical presentation and neuroimaging findings of children with pseudotumoral hemicerebellitis (PTHC) and Lhermitte-Duclos disease (LDD) may be very similar. The differentiation between these entities, however, is important because their management and prognosis are different. We report on three children with PTHC. For all three children, in the acute situation, the differentiation between PTHC and LDD was challenging. A review of the literature shows that a detailed evaluation of conventional and neuroimaging data may help to differentiate between these two entities. A striated folial pattern, brainstem involvement, and prominent veins surrounding the thickened cerebellar foliae on susceptibility weighted imaging favor LDD, while post-contrast enhancement and an increased choline peak on (1)H-Magnetic resonance spectroscopy suggest PTHC. PMID:26649682

  18. Optimal compression and binarization of signature profiles for automated bullet identification systems

    NASA Astrophysics Data System (ADS)

    Chu, Wei; Song, John; Vorburger, Theodore; Thompson, Robert; Renegar, Thomas; Silver, Richard

    2010-06-01

    In some automated bullet identification systems, the similarity of striation marks between different bullets is measured using the cross correlation function of the compressed signature profile extracted from a land impression. Inclusion of invalid areas weakly striated by barrel features may lead to sub-optimal extraction of the signature profile and subsequent deterioration of correlation results. In this paper, a method for locating striation marks and selecting valid correlation areas based on an edge detection technique is proposed for the optimal extraction of the compressed signature profiles. Experimental results from correlating 48 bullets fired from 12 gun barrels of 6 manufacturers have demonstrated a higher correct matching rate than the previous study results without correlation area selection processing. Furthermore, an attempt to convert a traditional profile with multiple z-quantization (or gray scale) levels into a binary profile is made for the purpose of reducing storage space and increasing correlation speed.

  19. The local subsurface water and chlorine distributions evaluated by DAN/MSL in Curiosity observational campaigns

    NASA Astrophysics Data System (ADS)

    Litvak, Maxim; Mitrofanov, Igor; Hardgrove, Craig; Sanin, Anton; Lisov, Denis; Golovin, Dmitry; Jun, Insoo; Kozyrev, Alexander; Malakhov, Alexey; Mischna, Michael; Moersch, Jeffrey; Nikiforov, Sergey; Tate, Cristopher; Vostrukhin, Andrey

    2016-04-01

    The measurements with the Dynamic Albedo of Neutrons (DAN) instrument onboard the Mars Science Laboratory (MSL) Curiosity rover are presented and analyzed as a summary of observations acquired during several special observational campaigns at the Yellowknife Bay area (first discovery of habitability environment), at the striated units of Kimberley formation, at outcrops studied in Pahrump Hills (at the base of Mt Sharp) and in high silica area discovered in Marias Pass (Mudstone facies of the Murray formation). DAN data were analyzed to test local and global variability in the distribution of bulk hydrogen and neutron-absorbing elements, characterized as chlorine-equivalent concentration. Using multi instrument approach in the data analysis we have compared DAN estimations of subsurface H and Cl distributions with inhomogeneity of local geological context, top surface measurements of chlorine with APXS and with SAM measurements of absorbed H2O extracted from the drilled samples based on low temperature evolved gas analysis.

  20. Molluscan visceral muscle fine structure. General structure and sarcolemmal organization in the smooth muscle of the intestinal wall of Buccinum undatum L.

    PubMed

    Hunt, S

    1981-01-01

    Fine structure of intestinal muscle in the gastropod Buccinum undatum is described. Myofibrillar organization is typical of non-pseudostriated molluscan muscles. The dense body system is poorly developed but there are extensive attachments plaques. The sarcolemma is elaborately modified. Deep infoldings of the membrane give the cells an irregular outline. Such infoldings enclose extracellular matrix and are associated with attachment plaques. Arising from these and from the general sarcolemma are numerous tubular membranous invaginations ending blindly at varying depth in the sarcoplasm. These structures have a helical coat of particles on the cytoplasmic face. Associated with both types of invagination are subsarcolemmal vesicles. The possibility that the tubular invaginations are analogues of vertebrate smooth muscle caveolae or striated muscle T-tubules and that the vesicles are the corresponding sarcoplasmic reticulum is discussed. The occurrence of such structures in molluscan muscle and elsewhere is reviewed.

  1. Localization of reducing group activity in the structural protein ribbons of the egg capsule of the gastropod mollusc Buccinum undatum L.

    PubMed

    Hunt, S; Price, N R

    1977-01-01

    Egg capsules of the gastropod molluse Buccinum undatum L. show a staining reaction with silver-methenamine reagent with prior treatment with periodate. The reactivity is specifically localized on the striated structural protein ribbons which form the capsule walls. The staining is in the region of ribbon most resistant to chemical degradation and where the constituent protein monomers are believed to overlap and be cross-linked. Since the proteins contain little cysteine it is likely that the staining originates in aldehyde groups. Staining is abolished by borohydride reduction. It is suggested that the aldehyde groups are a locus of stabilization and cross-linking since previous work has also shown association of an aldehyde secretion with hardening of the capsules.

  2. Atrophy of submandibular gland by the duct ligation and a blockade of SP receptor in rats

    PubMed Central

    Hishida, Sumiyo; Ozaki, Noriyuki; Honda, Takashi; Shigetomi, Toshio; Ueda, Minoru; Hibi, Hideharu; Sugiura, Yasuo

    2016-01-01

    ABSTRACT To clarify the mechanisms underlying the submandibular gland atrophies associated with ptyalolithiasis, morphological changes were examined in the rat submandibular gland following either surgical intervention of the duct or functional blockade at substance P receptors (SPRs). Progressive acinar atrophy was observed after duct ligation or avulsion of periductal tissues. This suggested that damage to periductal tissue involving nerve fibers might contribute to ligation-associated acinar atrophy. Immunohistochemically labeled-substance P positive nerve fibers (SPFs) coursed in parallel with the main duct and were distributed around the interlobular, striated, granular and intercalated duct, and glandular acini. Strong SPR immunoreactivity was observed in the duct. Injection into the submandibular gland of a SPR antagonist induced marked acinar atrophy. The results revealed that disturbance of SPFs and SPRs might be involved in the atrophy of the submandibular gland associated with ptyalolithiasis. PMID:27303108

  3. Araceae from the Early Cretaceous of Portugal: Evidence on the emergence of monocotyledons

    PubMed Central

    Friis, Else Marie; Pedersen, Kaj Raunsgaard; Crane, Peter R.

    2004-01-01

    A new species (Mayoa portugallica genus novum species novum) of highly characteristic inaperturate, striate fossil pollen is described from the Early Cretaceous (Barremian–Aptian) of Torres Vedras in the Western Portuguese Basin. Based on comparison with extant taxa, Mayoa is assigned to the tribe Spathiphylleae (subfamily Monsteroideae) of the extant monocotyledonous family Araceae. Recognition of Araceae in the Early Cretaceous is consistent with the position of this family and other Alismatales as the sister group to all other monocots except Acorus. The early occurrence is also consistent with the position of Spathiphylleae with respect to the bulk of aroid diversity. Mayoa occurs in the earliest fossil floras (from circa 110 to 120 million years ago) that contain angiosperm flowers, carpels, and stamens. The new fossil provides unequivocal evidence of monocots in early angiosperm assemblages that also include a variety of key “magnoliid” lineages (e.g., Chloranthaceae) but only a limited diversity of eudicots. PMID:15546982

  4. Microscopy of the echidna sublingual glands.

    PubMed

    Krause, William J

    2011-10-01

    The secretory units and duct system of the echidna sublingual glands exhibit subtle architectural modifications to accommodate the viscous secretion produced by these glands. The glands are compound tubular glands, the secretory units of which are elongate with open lumina and consist only of mucous cells. Closely packed spindle-shaped myoepithelial cells invest the secretory units, but are absent around the ducts. The branched secretory tubules open into an abbreviated duct system characterized by wide lumina. Striated ducts normally associated with the second portion of the intralobular duct system are absent. The duct system shows the most obvious modification of general salivary gland architecture presumably to accommodate the viscous secretion propelled from the secretory units by surrounding myoepithelial cells. PMID:21671992

  5. Spatial contrast sensitivity in unilateral cerebral ischaemic lesions involving the posterior visual pathway.

    PubMed

    Bulens, C; Meerwaldt, J D; van der Wildt, G J; Keemink, C J

    1989-04-01

    Contrast sensitivity function was studied in 16 patients with unilateral ischaemic lesions involving the posterior visual pathway. Sixty-two percent of the patients showed contrast sensitivity loss in at least one eye for horizontal or vertical stimulus orientation. Visual perception was distorted in a qualitatively different way according to the anteroposterior site of the lesion. Patients with occipital or occipitotemporal lesions showed high spatial frequency selective losses and patients with temporal or parietal lesions low frequency selective losses. Stimulus orientation selectivity was observed in patients with lesions of the primary visual cortex as well as in patients with lesions anterior to the striate cortex. Contrast sensitivity orientation-selective losses were demonstrated in 14 of the 17 'affected' eyes. PMID:2706442

  6. The dorsal skinfold chamber: A versatile tool for preclinical research in tissue engineering and regenerative medicine.

    PubMed

    Laschke, M W; Menger, M D

    2016-09-20

    The dorsal skinfold chamber is a rodent model for non-invasive microcirculatory analyses of striated muscle and skin tissue throughout an observation period of 2-3 weeks. In combination with intravital fluorescence microscopy, this model allows the quantitative assessment of dynamic processes such as inflammation, angiogenesis, vascular remodelling and microcirculation. Accordingly, the dorsal skinfold chamber is increasingly used for preclinical research in tissue engineering and regenerative medicine. This includes studies on biocompatibility, vascularisation and incorporation of medical implants and artificial tissue constructs. Moreover, the chamber implantation procedure has been modified to analyse primary and secondary wound healing as well as revascularisation and blood perfusion of dermal substitutes, skin grafts and myocutaneous flaps. Hence, the dorsal skinfold chamber model does not only provide deep insights into fundamental regenerative mechanisms but also represents a versatile tool for the development of novel therapeutic strategies.

  7. The stone man disease: fibrodysplasia ossificans progressiva: imaging revisited

    PubMed Central

    Verma, Amit Kumar; Aga, Pallavi; Singh, Shailesh Kumar; Singh, Ragini

    2012-01-01

    Fibrodysplasia ossificans progressiva (FOP) is a rare, disabling connective tissue disorder of unknown aetiology. Its occurrence is usually sporadic but may be an inherited autosomal-dominant condition with wide range of expression. FOP is characterised by congenital malformations of the great toes and abnormal progressive heterotopic ossification of striated muscles, tendons, ligaments, fascia and aponeuroses of the trunk and extremities leading to painful swellings. The ossifications typically appear within the first decade of life, resulting in progressive morbidity and severe disability. So far, there has been no effective treatment or prevention. In the early localised phase of disease it may be misdiagnosed, hence the role of correct diagnosis through imaging is essential. Herein, we report a case of a 10-year-old female who was evaluated radiologically and diagnosed as a case of FOP. The findings of plain radiography are described and the role of CT is highlighted. PMID:22843760

  8. The Early Miocene Cape Melville Formation fossil assemblage and the evolution of modern Antarctic marine communities

    NASA Astrophysics Data System (ADS)

    Whittle, Rowan J.; Quaglio, Fernanda; Griffiths, Huw J.; Linse, Katrin; Crame, J. Alistair

    2014-01-01

    The fossil community from the Early Miocene Cape Melville Formation (King George Island, Antarctica) does not show the archaic retrograde nature of modern Antarctic marine communities, despite evidence, such as the presence of dropstones, diamictites and striated rocks, that it was deposited in a glacial environment. Unlike modern Antarctic settings, and the upper units of the Eocene La Meseta Formation on Seymour Island, Antarctica, which are 10 million years older, the Cape Melville Formation community is not dominated by sessile suspension feeding ophiuroids, crinoids or brachiopods. Instead, it is dominated by infaunal bivalves, with a significant component of decapods, similar to present day South American settings. It is possible that the archaic retrograde structure of the modern community did not fully evolve until relatively recently, maybe due to factors such as further cooling and isolation of the continent leading to glaciations, which resulted in a loss of shallow shelf habitats.

  9. Loss of Sarcomere-associated Formins Disrupts Z-line Organization, but does not Prevent Thin Filament Assembly in Caenorhabditis elegans Muscle

    PubMed Central

    Mi-Mi, Lei; Pruyne, David

    2015-01-01

    Members of the formin family of actin filament nucleation factors have been implicated in sarcomere formation, but precisely how these proteins affect sarcomere structure remains poorly understood. Of six formins in the simple nematode Caenorhabditis elegans, only FHOD-1 and CYK-1 contribute to sarcomere assembly in the worm's obliquely striated body-wall muscles. We analyze here the ultrastructure of body-wall muscle sarcomeres in worms with putative null fhod-1 and cyk-1 gene mutations. Contrary to a simple model that formins nucleate actin for thin filament assembly, formin mutant sarcomeres contain thin filaments. Rather, formin mutant sarcomeres are narrower and have deformed thin filament-anchoring Z-line structures. Thus, formins affect multiple aspects of sarcomere structure. PMID:26161293

  10. Laser and chemical surface modifications of titanium grade 2 for medical application

    NASA Astrophysics Data System (ADS)

    Kwaśniak, P.; Pura, J.; Zwolińska, M.; Wieciński, P.; Skarżyński, H.; Olszewski, L.; Marczak, J.; Garbacz, H.; Kurzydłowski, K. J.

    2015-05-01

    The article presents combined, chemical and physical approach to titanium surface functionalization designed for biomedical applications. The topography modification has been obtained by employing the double laser beam interference technique and chemical etching. In the outcome, clean and smooth Ti surface as well as periodic striated topography with the roughness range from nano- to micrometers were created. The obtained structures were characterized in terms of shape, roughness, chemical composition, mechanical properties and microstructures. In order to achieve all information, numerous of research methods have been used: scanning electron microscopy, atomic force microscopy, optical profilometry and microhardness measurements. Demonstrated methodology can be used as an effective tool for manufacturing controlled surface structures improving the bone-implants interactions.

  11. Application of electrical stimulation for functional tissue engineering in vitro and in vivo

    NASA Technical Reports Server (NTRS)

    Radisic, Milica (Inventor); Park, Hyoungshin (Inventor); Langer, Robert (Inventor); Freed, Lisa (Inventor); Vunjak-Novakovic, Gordana (Inventor)

    2013-01-01

    The present invention provides new methods for the in vitro preparation of bioartificial tissue equivalents and their enhanced integration after implantation in vivo. These methods include submitting a tissue construct to a biomimetic electrical stimulation during cultivation in vitro to improve its structural and functional properties, and/or in vivo, after implantation of the construct, to enhance its integration with host tissue and increase cell survival and functionality. The inventive methods are particularly useful for the production of bioartificial equivalents and/or the repair and replacement of native tissues that contain electrically excitable cells and are subject to electrical stimulation in vivo, such as, for example, cardiac muscle tissue, striated skeletal muscle tissue, smooth muscle tissue, bone, vasculature, and nerve tissue.

  12. Studies on the pathogenesis of shimao zheng (fleece-eating) in sheep and goats.

    PubMed

    Youde, H; Huaitao, C

    2001-12-01

    Research on the disease called shimao zheng, which had resulted in widespread fleece-eating and shedding by sheep and goats in the Haizi area of Akesa County of Gansu Province of China, was carried out by both laboratory studies and pathological observations. There was a marked deficiency of sulfur in the wool and tissues of the affected animals. The pathological changes were mainly loss of fleece, exposure of the skin, keratinization of the epidermal cells, narrowing and reduced numbers of the fleece follicles, and fewer sebaceous glands and sweat glands. Histologically, there was atrophy of the striated and cardiac muscles and of the epithelium of the convoluted tubules of the kidney, together with a glomerulonephritis. The disease was considered to be a local nutritional and metabolic disorder, probably mainly caused by sulfur deficiency.

  13. Ultrastructure and immunofluorescence of the midgut of Bombus morio (Hymenoptera: Apidae: Bombini).

    PubMed

    Gonçalves, Wagner Gonzaga; Fernandes, Kenner Morais; Barcellos, Marcelo Silva; Silva, Fernanda Pereira; Magalhães-Junior, Marcos Jorge; Zanuncio, José Cola; Martins, Gustavo Ferreira; Serrão, José Eduardo

    2014-06-01

    Bumblebees are widely distributed across the world and have great economic and ecological importance as pollinators in the forest as well as in agriculture. The insect midgut consists of three cell types, which play various important roles in digestion, absorption, and hormone production. The present study characterized the anterior and posterior midgut regions of the bumblebee, Bombus morio. The digestive, regenerative and endocrine cells in the midgut showed regional differences in their number, nuclear size, as well as the size of the striated border. Ultrastructurally, the digestive cells contained many mitochondria and long microvilli; however, in the anterior midgut region, these cells showed dilated basal labyrinths with a few openings for the hemocoel, whereas the labyrinths of the basal posterior region remained inverse characteristics. Thus, the characterization of the midgut of B. morio supported an ecto-endoperitrophic circulation, contributing to a better understanding of the digestive process in this bee.

  14. Mutations in either the essential or regulatory light chains of myosin are associated with a rare myopathy in human heart and skeletal muscle.

    PubMed

    Poetter, K; Jiang, H; Hassanzadeh, S; Master, S R; Chang, A; Dalakas, M C; Rayment, I; Sellers, J R; Fananapazir, L; Epstein, N D

    1996-05-01

    The muscle myosins and hexomeric proteins consisting of two heavy chains and two pairs of light chains, the latter called essential (ELC) and regulatory (RLC). The light chains stabilize the long alpha helical neck of the myosin head. Their function in striated muscle, however, is only partially understood. We report here the identification of distinct missense mutations in a skeletal/ventricular ELC and RLC, each of which are associated with a rare variant of cardiac hypertrophy as well as abnormal skeletal muscle. We show that myosin containing the mutant ELC has abnormal function, map the mutant residues on the three-dimensional structure of myosin and suggest that the mutations disrupt the stretch activation response of the cardiac papillary muscles.

  15. BAG3 Deficiency Results in Fulminant Myopathy and Early Lethality

    PubMed Central

    Homma, Sachiko; Iwasaki, Masahiro; Shelton, G. Diane; Engvall, Eva; Reed, John C.; Takayama, Shinichi

    2006-01-01

    Bcl-2-associated athanogene 3 (BAG3) is a member of a conserved family of cyto-protective proteins that bind to and regulate Hsp70 family molecular chaperones. Here, we show that BAG3 is prominently expressed in striated muscle and colocalizes with Z-disks. Mice with homozygous disruption of the bag3 gene developed normally but deteriorated postnatally with stunted growth evident by 1 to 2 weeks of age and death by 4 weeks. BAG3-deficient animals developed a fulminant myopathy characterized by noninflammatory myofibrillar degeneration with apoptotic features. Knockdown of bag3 expression in cultured C2C12 myoblasts increased apoptosis on induction of differentiation, suggesting a need for bag3 for maintenance of myotube survival and confirming a cell autonomous role for bag3 in muscle. We conclude that although BAG3 is not required for muscle development, this co-chaperone appears to be critically important for maintenance of mature skeletal muscle. PMID:16936253

  16. The stone man disease: fibrodysplasia ossificans progressiva: imaging revisited.

    PubMed

    Verma, Amit Kumar; Aga, Pallavi; Singh, Shailesh Kumar; Singh, Ragini

    2012-07-25

    Fibrodysplasia ossificans progressiva (FOP) is a rare, disabling connective tissue disorder of unknown aetiology. Its occurrence is usually sporadic but may be an inherited autosomal-dominant condition with wide range of expression. FOP is characterised by congenital malformations of the great toes and abnormal progressive heterotopic ossification of striated muscles, tendons, ligaments, fascia and aponeuroses of the trunk and extremities leading to painful swellings. The ossifications typically appear within the first decade of life, resulting in progressive morbidity and severe disability. So far, there has been no effective treatment or prevention. In the early localised phase of disease it may be misdiagnosed, hence the role of correct diagnosis through imaging is essential. Herein, we report a case of a 10-year-old female who was evaluated radiologically and diagnosed as a case of FOP. The findings of plain radiography are described and the role of CT is highlighted.

  17. Protein machines and self assembly in muscle organization

    NASA Technical Reports Server (NTRS)

    Barral, J. M.; Epstein, H. F.

    1999-01-01

    The remarkable order of striated muscle is the result of a complex series of protein interactions at different levels of organization. Within muscle, the thick filament and its major protein myosin are classical examples of functioning protein machines. Our understanding of the structure and assembly of thick filaments and their organization into the regular arrays of the A-band has recently been enhanced by the application of biochemical, genetic, and structural approaches. Detailed studies of the thick filament backbone have shown that the myosins are organized into a tubular structure. Additional protein machines and specific myosin rod sequences have been identified that play significant roles in thick filament structure, assembly, and organization. These include intrinsic filament components, cross-linking molecules of the M-band and constituents of the membrane-cytoskeleton system. Muscle organization is directed by the multistep actions of protein machines that take advantage of well-established self-assembly relationships. Copyright 1999 John Wiley & Sons, Inc.

  18. Early recurrent feedback facilitates visual object recognition under challenging conditions

    PubMed Central

    Wyatte, Dean; Jilk, David J.; O'Reilly, Randall C.

    2014-01-01

    Standard models of the visual object recognition pathway hold that a largely feedforward process from the retina through inferotemporal cortex leads to object identification. A subsequent feedback process originating in frontoparietal areas through reciprocal connections to striate cortex provides attentional support to salient or behaviorally-relevant features. Here, we review mounting evidence that feedback signals also originate within extrastriate regions and begin during the initial feedforward process. This feedback process is temporally dissociable from attention and provides important functions such as grouping, associational reinforcement, and filling-in of features. Local feedback signals operating concurrently with feedforward processing are important for object identification in noisy real-world situations, particularly when objects are partially occluded, unclear, or otherwise ambiguous. Altogether, the dissociation of early and late feedback processes presented here expands on current models of object identification, and suggests a dual role for descending feedback projections. PMID:25071647

  19. The STARS signaling pathway: a key regulator of skeletal muscle function.

    PubMed

    Lamon, Séverine; Wallace, Marita A; Russell, Aaron P

    2014-09-01

    During the last decade, the striated muscle activator of Rho signaling (STARS), a muscle-specific protein, has been proposed to play an increasingly important role in skeletal muscle growth, metabolism, regeneration and stress adaptation. STARS influences actin dynamics and, as a consequence, regulates the myocardin-related transcription factor A/serum response factor (MRTF-A/SRF) transcriptional program, a well-known pathway controlling skeletal muscle development and function. Muscle-specific stress conditions, such as exercise, positively regulates, while disuse and degenerative muscle diseases are associated with a downregulation of STARS and its downstream partners, suggesting a pivotal role for STARS in skeletal muscle health. This review provides a comprehensive overview of the known role and regulation of STARS and the members of its signaling pathway, RhoA, MRTF-A and SRF, in skeletal muscle.

  20. Therapeutic gymnastics in comprehensive treatment of patients with generalized myasthenia

    NASA Technical Reports Server (NTRS)

    Kapelovich, R. L.

    1980-01-01

    The technique of therapeutic gymnastics was used for patients with mayasthenia gravis to control the consequences of hypodynamia induced by the myasthenic process. It is concluded that during myasthenia, the severity of the disease is due to the affection of the cross striated musculature. The most life threatening are the disorders in respiration and swallowing, that can be intensified by forced stay in bed and immobility. It is also concluded that the use of therapeutic gymnastics in patients which myasthenia promotes efficient presurgical preparation, and in the post surgical period; prevention of pulmonary complications and normalization of respiration. Therapeutic gymnastics with regard to the severity and localization of the myasthenic disorders must be a component part of the presurgical preparation and postsurgical management of patients with generalized myasthenia.

  1. Giant kidney worm (Dioctophyma renale) infection mimicking retroperitoneal neoplasm.

    PubMed

    Sun, T; Turnbull, A; Lieberman, P H; Sternberg, S S

    1986-07-01

    A 50-year-old Chinese man was found by ultrasound and computed tomography to have a retroperitoneal mass in the right upper quadrant of the abdomen. At operation, a hemorrhagic cyst was detected at the upper pole of the right kidney adjacent to the adrenal gland. Microscopic examination revealed that the cyst wall was composed of granulomatous tissue loaded with eggs and cross-sections of parasites, identified as Dioctophyma renale. The eggs were characterized by a birefringent striated double wall. The presence of cross sections of adult worms of D. renale in human tissue has not been previously described. Another unique feature of this case was that the right kidney was intact, as examined grossly at laparotomy and by intravenous pyelography. Eggs were not detected in the urine.

  2. Normal anatomic relationship between urethral sphincter complex and zones of prostrate in young Chinese males on MRI

    PubMed Central

    Wang, Xiangdong; Liu, Tieyan; Zhao, Jing; Sun, Jingyi; Chen, Yuefeng; Sun, Pengyu; Wang, Xuesong; Liu, Sheng

    2015-01-01

    Objective In this research, the normal anatomic relationship between urethral sphincter complex and zones of prostrate in young Chinese males has been studied. Methods: The sagittal, coronal, and axial T2-weighted non-fat suppressed fast spin-echo images of pelvic cavities of 86 Chinese young males were studied. Result: Urethral sphincter complex threaded through the prostate and divided it into 2 parts: transition zone (TZ), periurethral glands internal to the urethral sphincter and peripheral zone (PZ), central zone (CZ), anterior fibromuscular stroma (AFS) zone external to the urethral sphincter. The length of urethral striated sphincter is 12.26-20.94 mm (mean 16.59 mm) at membranous urethra. Conclusions: In this paper, we summarized the normal anatomic relationship between urethral sphincter complex and zones of prostrate in young Chinese males with no urinary control problems. PMID:26629244

  3. Tissue Differentiation: A Personal Account of Research on Myogenesis and Cardiogenesis.

    PubMed

    Buckingham, Margaret

    2016-01-01

    In this essay I trace my own research experience as a developmental biologist, from the study of cell differentiation in vitro to tissue formation and regeneration in vivo. Beginning with a thesis on histone modifications, I went on to study gene regulation during myogenesis, first in muscle cells in culture and then in the mouse embryo. Later, we also worked on muscle regeneration in the adult. Our work on striated muscle genes also led us into the field of cardiogenesis and characterization of cardiac progenitor cells that form the heart. Comments on the state of the art--changing concepts and the technological advances that underlie scientific progress--accompany this account, with concluding remarks about future directions. PMID:26970617

  4. Neurophysiologic intraoperative monitoring of the glossopharyngeal and vagus nerves.

    PubMed

    Singh, Rajdeep; Husain, Aatif M

    2011-12-01

    Neurophysiologic intraoperative monitoring (NIOM) of the glossopharyngeal and vagus nerves (CN IX and X) is often used during surgeries involving the lower brain stem. Although both of these nerves contain sensory, autonomic, and motor fibers, it is the motor fibers that are most amenable to NIOM. CN IX supplies the stylopharyngeus muscle, and CN X supplies striated muscles in the soft palate, pharynx, and larynx. Monitoring of these CN can be performed by monitoring free running and stimulated electromyography (EMG) from the stylopharyngeus muscle (CN IX) and the vocal cords (CN X). Various surface and needle electrodes can be used to monitor these muscle groups. When CN IX is monitored, CN X should also be monitored, as it is often needed to differentiate when CN IX is selectively activated. Data are accumulating noting the use of monitoring these CN in tumor surgeries involving the lower brain stem. PMID:22146360

  5. Sarcocystis dubeyi (Huong and Uggla, 1999) infection in water buffaloes (Bubalus bubalis) from Egypt.

    PubMed

    Hilali, M; El-Seify, M; Zayed, A; El-Morsey, A; Dubey, J P

    2011-06-01

    Water buffaloes (Bubalus bubalis) are intermediate hosts for 4 species of Sarcocystis , i.e., Sarcocystis fusiformis and Sarcocystis buffalonis with cats as definitive hosts; Sarcocystis levinei with dogs as definitive hosts; and Sarcocystis dubeyi with an unknown definitive host but thought to be zoonotic. Currently, the latter species has been identified with certainty only from Vietnam. In the present study, sarcocysts of S. dubeyi are reported in 11 (30%) of 35 Egyptian water buffaloes from which the esophageal muscles were examined histologically. Sarcocysts were microscopic, measuring 180-250 × 70-110 µm in size. Ultrastructurally, the sarcocyst wall was 3.5-6.5 µm thick and had palisade-like villar protrusions which give it a striated appearance. The villar protrusions contained microtubules that were distributed along the whole villus. This is the first report of S. dubeyi from water buffaloes in Egypt.

  6. 2,3,6-triaminopyridine, a metabolite of the urinary tract analgesic phenazopyridine, causes muscle necrosis and renal damage in rats.

    PubMed

    Munday, R; Manns, E

    1998-01-01

    Some aromatic polyamines form very stable free radicals and readily undergo autoxidation with concomitant formation of 'active oxygen' species. These substances cause necrosis of striated muscle in rats, and it has been suggested that this is due to free radical formation and disruption of energy production through their oxidation via the cytochrome c/cytochrome oxidase system of mitochondria. 2,3,6-Triaminopyridine, which is structurally related to the myotoxic amines and likewise undergoes autoxidation and disrupts mitochondrial metabolism, is a metabolite of the widely used urinary analgesic phenazopyridine. When administered to rats, triaminopyridine caused extensive necrosis of skeletal muscle and a lesser degree of damage to heart muscle. It also induced vacuolation and necrosis of distal tubules of the kidney, associated with tubular dilatation and cast formation. Both muscle damage and renal tubular necrosis have been reported following use or abuse of phenazopyridine, and it is likely that triaminopyridine is responsible for both of these effects.

  7. Gastric emptying, small intestinal transit and fecal output in dystrophic (mdx) mice.

    PubMed

    Mulè, Flavia; Amato, Antonella; Serio, Rosa

    2010-01-01

    Duchenne muscular dystrophy (DMD), which results from deficiency in dystrophin, a sarcolemma protein of skeletal, cardiac and smooth muscle, is characterized by progressive striated muscle degeneration, but various gastrointestinal clinical manifestations have been observed. The aim was to evaluate the possible impact of the dystrophin loss on the gastrointestinal propulsion in mdx mice (animal model for DMD). The gastric emptying of a carboxymethyl cellulose/phenol red dye non-nutrient meal was not significantly different at 20 min from gavaging between wild-type and mdx mice. The intestinal transit and the fecal output were significantly decreased in mdx versus normal animals, although the length of the intestine was similar in both animals. The present results provide evidence for motor intestinal alterations in mdx mice in in vivo conditions. PMID:19784719

  8. A review of environmental characteristics and health effects of barium in public water supplies.

    PubMed

    Kojola, W H; Brenniman, G R; Carnow, B W

    1979-01-01

    A comprehensive review is made of sources, occurrence, removal, health effects and water quality standard of barium in public drinking water supplies. The primary source of naturally occurring barium in drinking water results from the leaching and eroding of this metal from sedimentary rocks into the aquifers of ground water. It is a localized problem in several areas of the United States. The removal of barium from drinking water appears to be most efficiently accomplished utilizing ion exchange softening. Health effects studies are based primarily on animal experimentation. Such effects include stimulation of smooth, striated, and cardiac muscle, elevation of blood pressure, initiation of catecholamine release, rapid and preferential deposition in bone, and excretion principally in the feces. Humans over 60 years of age appear to be at high risk to developing cardiac arrhythmias following the barium enema. The current United States drinking water standard of 1.0 mg/l is based on several faulty assumptions and should be critically reevaluated.

  9. Static lung compliance and body pressures in Tupinambis merianae with and without post-hepatic septum.

    PubMed

    Klein, Wilfried; Abe, Augusto S; Perry, Steven F

    2003-04-15

    The surgical removal of the post-hepatic septum (PHS) in the tegu lizard, Tupinambis merianae, significantly reduces resting lung volume (V(Lr)) and maximal lung volume (V(Lm)) when compared with tegus with intact PHS. Standardised for body mass (M(B)), static lung compliance was significantly less in tegus without PHS. Pleural and abdominal pressures followed, like ventilation, a biphasic pattern. In general, pressures increased during expiration and decreased during inspiration. However, during expiration pressure changes showed a marked intra- and interindividual variation. The removal of the PHS resulted in a lower cranio-caudal intracoelomic pressure differential, but had no effect on the general pattern of pressure changes accompanying ventilation. These results show that a perforated PHS that lacks striated muscle has significant influence on static breathing mechanics in Tupinambis and by analogy provides valuable insight into similar processes that led to the evolution of the mammalian diaphragm.

  10. Canalicular adenoma--search for the cell of origin: ultrastructural and immunohistochemical analysis of 7 cases and review of the literature.

    PubMed

    Huebner, Thomas A; Almubarak, Hussain; Drachenberg, Cinthia B; Papadimitriou, John C

    2014-04-01

    Canalicular adenoma (CA) is a rare, benign epithelial neoplasm of the salivary glands. Historically considered to be a variant of basal cell adenoma, this "monomorphic" adenoma has a distinct clinical, morphologic, and immunohistochemical profile. The putative cell of origin remains a topic of debate. A combination of morphology, immunohistochemistry, and ultrastructural analyses have been employed to determine histogenesis, but the interpretations of these studies have implicated multiple different cell types along the salivary gland duct as the cell of origin. The authors sought to further characterize CA using electron microscopy, immunohistochemistry, and special and immuno-stains on 7 cases. Their morphologic, immunohistochemical, and ultrastructural findings support a cell of origin demonstrating features of both the intercalated duct cells and the striated duct luminal epithelial cells.

  11. The Musculature of Coleoid Cephalopod Arms and Tentacles

    PubMed Central

    Kier, William M.

    2016-01-01

    The regeneration of coleoid cephalopod arms and tentacles is a common occurrence, recognized since Aristotle. The complexity of the arrangement of the muscle and connective tissues of these appendages make them of great interest for research on regeneration. They lack rigid skeletal elements and consist of a three-dimensional array of muscle fibers, relying on a type of skeletal support system called a muscular hydrostat. Support and movement in the arms and tentacles depends on the fact that muscle tissue resists volume change. The basic principle of function is straightforward; because the volume of the appendage is essentially constant, a decrease in one dimension must result in an increase in another dimension. Since the muscle fibers are arranged in three mutually perpendicular directions, all three dimensions can be actively controlled and thus a remarkable diversity of movements and deformations can be produced. In the arms and tentacles of coleoids, three main muscle orientations are observed: (1) transverse muscle fibers arranged in planes perpendicular to the longitudinal axis; (2) longitudinal muscle fibers typically arranged in bundles parallel to the longitudinal axis; and (3) helical or obliquely arranged layers of muscle fibers, arranged in both right- and left-handed helixes. By selective activation of these muscle groups, elongation, shortening, bending, torsion and stiffening of the appendage can be produced. The predominant muscle fiber type is obliquely striated. Cross-striated fibers are found only in the transverse muscle mass of the prey capture tentacles of squid and cuttlefish. These fibers have unusually short myofilaments and sarcomeres, generating the high shortening velocity required for rapid elongation of the tentacles. It is likely that coleoid cephalopods use ultrastructural modifications rather than tissue-specific myosin isoforms to tune contraction velocities. PMID:26925401

  12. Shatter cone and microscopic shock-alteration evidence for a post-Paleoproterozoic terrestrial impact structure near Santa Fe, New Mexico, USA

    NASA Astrophysics Data System (ADS)

    Fackelman, Siobhan P.; Morrow, Jared R.; Koeberl, Christian; McElvain, Thornton H.

    2008-06-01

    Field mapping, morphologic description, and petrographic analysis of recently discovered shatter cones within Paleoproterozoic crystalline rocks exposed over an area > 5 km 2, located ˜ 8 km northeast of Santa Fe, New Mexico, USA, give robust evidence of a previously unrecognized terrestrial impact structure. Herein, we provisionally name this the "Santa Fe impact structure". The shatter cones are composed of nested sub-conical, curviplanar, and flat joint surfaces bearing abundant curved and bifurcating striations that strongly resemble the multiply striated joint surfaces (MSJS) documented from shatter cones at Vredefort dome. The cones occur as a penetrative feature in intrusive igneous and supracrustal metamorphic rocks, are unusually large (up to 2 m long and 0.5 m wide at the base), display upward-pointing apices, and have subvertical, northeastward-plunging axes that crosscut regional host-rock fabrics. Key characteristics of superficially similar, but non-shock-generated conical and striated features are inconsistent with the properties of the Santa Fe cones. In thin section, sub-millimeter-scale, dark, semi-opaque to isotropic veneers on cone surfaces and veinlets within cone interiors closely resemble previously described shock-induced melt features. Microscopic grain alteration, restricted generally to within 1 mm of the cone surfaces, includes random fractures, fluid micro-inclusions, sericite replacement in feldspar, rare kink bands in mica, optical mosaicism, and decorated planar fractures (PFs) and planar deformation features (PDFs) in quartz. The PFs and PDFs are dominated by a basal (0001) crystallographic orientation, which indicate a peak shock pressure of ˜ 5-10 GPa that is consistent with shatter cone formation. Regional structural and exhumation models, together with anomalous breccia units that overlie and crosscut the shatter cone-bearing rocks, may provide additional age constraints for the impact event. The observed shatter cone outcrop

  13. Anatomic and acoustic sexual dimorphism in the sound emission system of Phoenicoprocta capistrata (Lepidoptera: Arctiidae)

    NASA Astrophysics Data System (ADS)

    Rodríguez-Loeches, Laura; Barro, Alejandro; Pérez, Martha; Coro, Frank

    2009-04-01

    Both sexes of Phoenicoprocta capistrata have functional tymbals. The scanning electron microscopy revealed differences in the morphology of these organs in males and females. Male tymbals have a well-developed striated band, constituted by 21 ± 2 regularly arranged striae whereas female tymbals lack a striated band. This type of sexual dimorphism is rare in Arctiidae. The recording of the sound produced by moths held by the wings revealed that while males produced trains of pulses organized in modulation cycles, females produced clicks at low repetition rate following very irregular patterns. Statistically, there are differences between sexes in terms of the duration of pulses, which were 355 ± 24 μs in the case of males and 289 ± 29 μs for females. The spectral characteristics of the pulses also show sexual dimorphism. Male pulses are more tuned ( Q 10 = 5.2 ± 0.5) than female pulses ( Q 10 = 2.7 ± 0.5) and have a higher best frequency (42 ± 1 kHz vs. 29 ± 2 kHz). To our knowledge, this is the first report on an arctiid moth showing sexual dimorphism in tymbal’s anatomy that leads to a best frequency dimorphism. Males produce sound at mating attempts. The sounds recorded during mating are modulation cycles with the same spectral characteristics as those recorded when males are held by the wings. The morphological and acoustic features of female tymbals could indicate a process of degeneration and adaptation to conditions under which the emission of complex patterns is not necessary.

  14. Spectrum of Infantile Esotropia in Primates: Behavior, Brains and Orbits

    PubMed Central

    Tychsen, Lawrence; Richards, Michael; Wong, Agnes; Foeller, Paul; Burhkalter, Andreas; Narasimhan, Anita; Demer, Joseph

    2009-01-01

    Introduction Recent studies of human infants have described a spectrum of early-onset esotropia, from small-variable-angle to large heterotropias.1 We report here a similar spectrum of early-onset esotropia in infant monkeys, with emphasis on the relationship between visuomotor deficits, central nervous system (CNS) circuitry and orbital anatomy. Methods Eye movements were recorded in macaque monkeys with natural, infantile-onset esotropia (n=7) and in control monkeys (n=2) to assess alignment, latent nystagmus, dissociated vertical deviation (DVD), and pursuit/optokinetic nystagmus (OKN) asymmetries. Acuity was measured by preferential-looking technique or spatial sweep VEP (SSVEP). Geniculo-striate pathways were then analyzed with neuroanatomic tracers and metabolic labels. Extraocular muscles were examined by high-resolution magnetic resonance imaging (MRI) and anatomic sectioning of whole orbits. Results Esotropia ranged from 4-13.5° (7-24 prism diopters [PD]) with fixation preference (if any) varying idiosyncratically (as in human). Severity of ocular motor dysfunction (i.e. nystagmus velocity, DVD amplitude, pursuit-OKN nasal bias index), increased as the magnitude of esotropia angle. Animals with greater ocular motor deficits tended to have greater visual area V1 (striate cortex) neuroanatomic deficits, evident as fewer binocular horizontal connections in V1. Orbital MRI/anatomic analysis showed no difference in horizontal rectus cross sectional areas, muscle paths, innervation densities or cytoarchitecture compared to normal animals. Conclusion The infantile esotropia spectrum in non-human primates is remarkably similar to that reported in human infants. Concomitant esotropia in these primates cannot be ascribed to abnormalities of the extraocular muscles or orbit. These findings, combined with epidemiologic studies of human, suggest that perturbations of CNS binocular pathways in early development are the primary cause of the infantile esotropia syndrome

  15. Model studies of intracellular acid-base temperature responses in ectotherms.

    PubMed

    Reeves, R B; Malan, A

    1976-10-01

    Measurements of intracellular pH (pHi) in air-breathing ectotherms have only been made in the steady state; these pHi indicate that protein charge state, measured as alpha imidazole (alphaIM), the fractional dissociation of protein histidine imidazole groups, is preserved when ectotherm tissues change temperature in vivo, with related changes in pHi and PCO2. In partial answer to the question of how such tissues are able to avoid disrupting transients to functions sensitive to protein charge states, model studies were carried out to assess the passive intracellular buffer system response to a combined change in body temperature and CO2 partial pressure as occurs in vivo in these species. The cell compartment was modeled as a closed volume of ternary buffer solution, containing protein imidazole (50 mM/1); phosphate (15 mM/1) and CO2-bicarbonate buffer components, permeable only to CO2 and permitted no change in buffer base. Excursions from a steady-state non-equilibrium pHi were computed to a step-change in temperature/PCO2. Computations for frog (Rana catesbeiana) striated muscle show that the calculated pHi response on the basis of estimated composition and concentration of cell buffer components, moves along the curve describing the steady-state temperature relationship. No transient away from steady-state alphaIM and carbon dioxide content need be postulated. Applications to turtle (Pseudemys scripta) striated muscle are also explored. These calculations show that ectotherm cells may be capable of responding without appreciable time for adaptation to intracellular acid-base state changes incurred by sudden alteration of body temperature in vivo, given the observed adjustments of blood PCO2 with temperature.

  16. Reproductive morphology of Brittanichthys axelrodi (Teleostei: Characidae), a miniature inseminating fish from South America.

    PubMed

    Javonillo, Robert; Burns, John R; Weitzman, Stanley H

    2007-01-01

    Light and electron microscopy were used to investigate the morphology of reproductive characters in a characid fish, Brittanichthys axelrodi. Spermatozoa were found in ovaries of females, thereby confirming insemination in this species. Bony hooks can be found on the fourth unbranched ray and branched rays 1-4 of the anal fin and the unique sigmoidally-curved ray of the caudal fin in mature males. Testes have three distinct regions: an anterior spermatogenic region, an aspermatogenic middle region lined with a simple squamous epithelium and used for storage of mature spermatozoa, and a posterior region of coiled chambers lined with a high simple cuboidal epithelium. The most posterior region appears to be instrumental in the formation and storage of spermatozeugmata, unencapsulated sperm packets. Thus far, this tripartite testis morphology is unique among characids. The mature spermatozoon has an elongate nucleus ( approximately 5 microm in length). A striated rootlet originates at the anterior end of the distal centriole and continues to the anterior tip of the cell. The striated rootlet wraps around the entire ventral area of the anterior part of the nucleus and appears to continue around the anterior tip of the nucleus and down the dorsal side as electron-dense material. Several large, spherical mitochondria ( approximately 0.6 microm in diameter) with lamellar cristae overlap the posterior end of the nucleus and continue beyond together with the cytoplasmic collar that contains the flagellum which lacks axonemal fins. Each spermatozeugma is lanceolate in shape when sectioned mid-sagitally, with the core staining positively for mucopolysaccharides. In both sexes, the gonopore opens posterior to the anus, with the urinary pore having a separate opening posterior to the gonopore. Bands of skeletal muscle were found in the area of the male gonopore. These morphological features are likely linked to the reproductive mode of insemination, a trait that is so far as

  17. Upper Cisuralian palynology and palaeoclimate of Manuguru area Godavari basin, India and their global correlation

    NASA Astrophysics Data System (ADS)

    K, Pauline Sabina; Jha, Neerja

    2014-10-01

    The Permian system of the Palaeozoic Erathem is divided into three series, the Early Permian Cisuralian Series, the Middle Permian Guadalupian Series, and the Late Permian Lopingian Series. The Cisuralian Series encompasses the Asselian to Kungurian stages which constitute the basal part of the Gondwana supersequence I. In India, they are represented lithostratigraphically by the Talchir, Karharbari, and Barakar formations. This paper presents the palynological results from the Barakar Formation of the Upper Cisuralian Series from Manuguru which lies in the southeastern part of the Godavari basin. The succession studied comprises 35 subsurface samples from bore hole 1007 represented by clay, shale, sandstone, and coal. The palynofloras in this sequence have a homogenous composition demonstrating that not many significant floral changes took place through the considered stratigraphic range. The entire sequence is characterized by the dominance of nonstriate bisaccate genus Scheuringipollenites and sub-dominance of striate bisaccate genus Faunipollenites(= Protohaploxypinus). The other pollen genera among the nonstriate bisaccates are Rhizomaspora, Primuspollenites, Ibisporites, and Platysaccus. The striate bisaccates include Striatites, Striatopodocarpites, and Stroterosporites. The taeniate taxa are represented by Lueckisporites and Lunatisporites. The common monosaccate genera include Caheniasaccites, Potoniesporites, and Barakarites. Spores are less common and include Latosporites, Brevitriletes, Horriditriletes, Microbaculispora, and Callumispora. They characterize the palynofloral composition of the Lower Barakar Formation. The correlation of this assemblage with some of the biostratigraphic palynozones proposed previously for the Cisuralian sequences of the Paraná Basin of South America, Kalahari Karoo Basin of South Africa, Ruhuhu Basin of Tanzania, East Africa as well as palynoassemblages from South Victoria Land and Dronning Maud Land, Antarctica and

  18. Die Cnidogenese der Octocorallia (Anthozoa, Cnidaria): II. Reifung, Wanderung und Zerfall von Cnidoblast und Nesselkapsel

    NASA Astrophysics Data System (ADS)

    Schmidt, H.; Moraw, B.

    1982-03-01

    Migration of cnidoblasts has never been observed in Anthozoa. In contrast to hydrozoans, anthozoans are repeatedly reported to develop nematocysts locally without migration in the entoderm as well as in the ectoderm. The majority of the nematocysts studied in different Octocorallia species (Alcyonaria: Alcyonarium digitatum, Parerythropodium coralloides; Gorgonaria: Pseudopterogorgia aerosa; Pennatularia: Veretillum cynomorium) originate from the ectoderm of the scapus, where, however, no mature nematocysts occur. Cnidoblasts containing immature nematocysts accumulate in the distal scapus, from where they migrate singly like amoebae into the pinnulae of the tentacles. The nematocysts mature during migration, during which the capsular matrix becomes completely electron-translucent. Only in the oral disc, where few nematocysts occur, do they mature locally without migration. In the Octocorallia, nematocyst development and maturation takes places only in the ectoderm. Development of nematocysts has never been observed in the entoderm, nor in the pharynx; this demonstrates its entodermal origin. The entoderm contains only degenerated or phagocytized nematocysts. Contrary to hydrozoans, the mature anthozoan cnidocyte is rounded and has no processes to the mesogloea. Instead of a cnidocil it has a ciliary cone consisting of a normal flagellum, stereocilia and macrovilli. The cnidocyte is characterised by abundant electron-translucent cytoplasm and nematocyst-anchoring structures made up of cross-striated, collagen-like fibrillae and a fibrous basal ring. The position of the cross-striated fibrillae is distally similar to that of the supportive rods in hydrozoan cnidoblasts. The present study clearly demonstrates that structure and, possibly, function of an octocorallian cnidocyte is much simpler than that of a hydrozoan cnidocyte. On the other hand, cnidoblast migration, occurring in Hydrozoa as well in Octocorallia, turned out to be a much older phylogenetic character

  19. MORPHOLOGICAL AND CHEMICAL STUDIES OF COLLAGEN FORMATION

    PubMed Central

    Lowther, D. A.; Green, N. M.; Chapman, J. A.

    1961-01-01

    Electron micrographs of thin sections of nuclear, microsomal, and mitochondrial fractions obtained from a carrageenin-induced granuloma showed considerable contamination of the heavier by the lighter fractions. Striated collagen fibrils could be identified in the nuclei + debris fraction. Only a few striated fibrils occurred in the mitochondrial fraction; very fine filaments (diameter 50 A) could be seen in this fraction, but could not be distinguished with certainty from fibrillar material derived from broken nuclei. 35 per cent of the mitochondrial and 80 per cent of the microsomal collagen was extractable by 0.2 M NaCl and could be purified by the standard methods of solution and reprecipitation. The amino acid composition of these collagen fractions determined by ion exchange chromatography was within the range normally found for collagen and gelatin from other mammalian species, allowing for 10 to 20 per cent of some non-collagenous contaminant of the microsomal collagen. Hydroxyproline and proline were isolated by chromatography on paper from hydrolysates of the nuclear, mitochondrial, and microsomal collagen fractions, after incubation of tissue slices with L-14C-proline. The specific activities of the hydroxyproline from these collagens were in the approximate ratio 1:2:6, while that of bound hydroxyproline derived from the supernatant was only 1, indicating primary synthesis of collagen in the microsomes. Attempts to demonstrate incorporation of L-14C-proline into collagen or into free hydroxyproline in cell free systems were unsuccessful, nor was it possible to demonstrate non-specific incorporation of L-14C-valine into TCA-insoluble material by various combinations of subcellular fractions. PMID:13763869

  20. The myogenic electric organ of Sternopygus macrurus: a non-contractile tissue with a skeletal muscle transcriptome

    PubMed Central

    Samanta, Manoj P.; Chaidez, Alexander

    2016-01-01

    In most electric fish species, the electric organ (EO) derives from striated muscle cells that suppress many muscle properties. In the gymnotiform Sternopygus macrurus, mature electrocytes, the current-producing cells of the EO, do not contain sarcomeres, yet they continue to make some cytoskeletal and sarcomeric proteins and the muscle transcription factors (MTFs) that induce their expression. In order to more comprehensively examine the transcriptional regulation of genes associated with the formation and maintenance of the contractile sarcomere complex, results from expression analysis using qRT-PCR were informed by deep RNA sequencing of transcriptomes and miRNA compositions of muscle and EO tissues from adult S. macrurus. Our data show that: (1) components associated with the homeostasis of the sarcomere and sarcomere-sarcolemma linkage were transcribed in EO at levels similar to those in muscle; (2) MTF families associated with activation of the skeletal muscle program were not differentially expressed between these tissues; and (3) a set of microRNAs that are implicated in regulation of the muscle phenotype are enriched in EO. These data support the development of a unique and highly specialized non-contractile electrogenic cell that emerges from a striated phenotype and further differentiates with little modification in its transcript composition. This comprehensive analysis of parallel mRNA and miRNA profiles is not only a foundation for functional studies aimed at identifying mechanisms underlying the transcription-independent myogenic program in S. macrurus EO, but also has important implications to many vertebrate cell types that independently activate or suppress specific features of the skeletal muscle program. PMID:27114860

  1. Geological Mapping of Tectonized Terrains in the Trailing Hemisphere of Enceladus

    NASA Astrophysics Data System (ADS)

    Crow-Willard, E. N.; Pappalardo, R. T.

    2009-05-01

    Saturn's moon Enceladus has a currently active South Polar Terrain (SPT) that is intensely tectonized. Other portions of the surface of Enceladus, specifically the trailing hemisphere, have also been intensely tectonized, inviting comparisons to the SPT. Through geological mapping, we recognize seven different geological units and their relative ages on the trailing hemisphere. From oldest to youngest, they are: (1) heavily cratered terrain, at the northern edge of the tectonized region; (2) moderately cratered terrain, to the northeast and northwest of the tectonized region; (3) finely striated ridge and trough terrain, which make up the bulk of Sarandib and Diyar Planitiae; (4) boundary curved terrain, which is similar in shape to the southern curved terrain that comprises the northern edge of the SPT, but with more subdued topography, and is composed of Samarkand, Hamah, and Harran Sulci; (5) ridged terrain, composed of the Cufa Dorsa and Ebony Dorsum, which probably formed through deformation of older finely striated ridge and trough terrain; (6) terrain with linear, widely spaced, smooth depressions, comprising the southern portion of the trailing hemisphere's tectonized region; (7) southern curved terrain of Cashmere Sulci, which forms the northern boundary of the SPT. Fractures that are younger than or contemporaneous with the SPT's southern curved terrain (including Labtayt Sulci and Khorasan Fossa) cut across the trailing hemisphere. We will present a geological map of the region, along with interpretations of the stratigraphy and geological history that our mapping implies. We will address geological and age comparisons relative to the SPT, with implications for whether similar or different processes have shaped the SPT and the tectonized trailing hemisphere.

  2. Salutary effect of gastric pentadecapeptide BPC 157 in two different stress urinary incontinence models in female rats

    PubMed Central

    Jandric, Ivan; Vrcic, Hrvoje; Balen, Marica Jandric; Kolenc, Danijela; Brcic, Luka; Radic, Bozo; Drmic, Domagoj; Seiwerth, Sven; Sikiric, Predrag

    2013-01-01

    Background Since an originally anti-ulcer stable gastric pentadecapeptide BPC 157 (PL 14736) was shown to promote healing of injured striated muscle and smooth muscle in the gastrointestinal tract, we explored its therapeutic potentials for leak point pressure (LPP) recovery in rat stress urinary incontinence (SUI) after transabdominal urethrolysis (TU) and prolonged vaginal dilatation (VD). Material/Methods During a 7-day period, TU-rats and VD-rats (or healthy rats) received BPC 157, either (i) intraperitoneally, 10 μg/kg or 10 ng/kg, once daily (first administration 30 min after surgery, last 24 h before LPP-testing and sacrifice), or (ii) per-orally, 10 μg/kg in drinking water (0.16 μg/mL, 12 mL/rat/day). Vesicourethral segments were harvested for immunohistochemical evaluation. Results All BPC 157 regimens counteracted decrease of LPP values in TU-rats and VD-rats. Additionally, BPC 157-TU rats (μg-intraperitoneally or per-orally) and BPC 157-VD rats (μg intraperitoneally) reached LPP values originally noted in healthy rats. Conversely, in healthy rats, BPC 157 did not alter LPP. Immunohistochemical studies revealed higher desmin (delineates striated organization of skeletal muscle), smooth muscle actin, and CD34 (angiogenic marker) positivity within the urethral wall in BPC 157-treated rats vs. controls, as well as overall preserved muscle/connective tissue ratio assessed with Mallory’s trichrome staining. Conclusions Pentadecapeptide BPC 157, applied parenterally or per-orally, appears to ameliorate the SUI in rat models, improving the otherwise detrimental course of healing after VD and TU, which may be analogous to human injury. These beneficial effects may possibly be selectively used in future strategies for treatment of SUI. PMID:23478678

  3. Background and stimulus-induced patterns of high metabolic activity in the visual cortex (area 17) of the squirrel and macaque monkey

    SciTech Connect

    Humphrey, A.L.; Hendrickson, A.E.

    1983-02-01

    We have used 2-deoxy-D-(/sup 14/C)glucose (2-DG) autoradiography and cytochrome oxidase histochemistry to examine background and stimulus-induced patterns of metabolic activity in monkey striate cortex. In squirrel monkeys (Saimiri sciureus) that binocularly or monocularly viewed diffuse white light or binocularly viewed bars of many orientations and spatial frequencies, 2-DG consumption was not uniform across the cortex but consisted of regularly spaced radial zones of high uptake. The zones extended through all laminae except IVc beta and, when viewed tangentially, formed separate patches 500 microns apart. The cytochrome oxidase stain in these animals also revealed patches of high metabolism which coincided with the 2-DG patches. Squirrel monkeys binocularly viewing vertical stripes showed parallel bands of increased 2-DG uptake in the cortex, while the cytochrome label in these animals remained patchy. When monkeys were kept in the dark during 2-DG exposure, 2-DG-labeled patches were not seen but cytochrome oxidase-positive patches remained. In macaque (Macaca nemestrina) monkeys, binocular stimulation with many orientations and spatial frequencies produced radial zones of high 2-DG uptake in layers I to IVa and VI. When viewed tangentially, these zones formed a dots-in-rows pattern with a spacing of 350 X 500 microns; cytochrome oxidase staining produced an identical pattern. Macaca differed from Saimiri in that monocular stimulation labeled alternate rows. These results indicate that there are radial zones of high background metabolism across squirrel and macaque monkey striate cortex. In Saimiri these zones do not appear to be related to an eye dominance system, while in Macaca they do. The presence of these zones of high metabolism may complicate the interpretation of 2-DG autoradiographs that result from specific visual stimuli.

  4. Sequential myosin phosphorylation activates tarantula thick filament via a disorder-order transition.

    PubMed

    Espinoza-Fonseca, L Michel; Alamo, Lorenzo; Pinto, Antonio; Thomas, David D; Padrón, Raúl

    2015-08-01

    Phosphorylation of myosin regulatory light chain (RLC) N-terminal extension (NTE) activates myosin in thick filaments. RLC phosphorylation plays a primary regulatory role in smooth muscles and a secondary (modulatory) role in striated muscles, which is regulated by Ca(2+)via TnC/TM on the thin filament. Tarantula striated muscle exhibits both regulatory systems: one switches on/off contraction through thin filament regulation, and another through PKC constitutively Ser35 phosphorylated swaying free heads in the thick filaments that produces quick force on twitches regulated from 0 to 50% and modulation is accomplished recruiting additional force-potentiating free and blocked heads via Ca(2+)4-CaM-MLCK Ser45 phosphorylation. We have used microsecond molecular dynamics (MD) simulations of tarantula RLC NTE to understand the structural basis for phosphorylation-based regulation in tarantula thick filament activation. Trajectory analysis revealed that an inter-domain salt bridge network (R39/E58,E61) facilitates the formation of a stable helix-coil-helix (HCH) motif formed by helices P and A in the unphosphorylated NTE of both myosin heads. Phosphorylation of the blocked head on Ser45 does not induce any substantial structural changes. However, phosphorylation of the free head on Ser35 disrupts this salt bridge network and induces a partial extension of helix P along RLC helix A. While not directly participating in the HCH folding, phosphorylation of Ser35 unlocks a compact structure and allows the NTE to spontaneously undergo coil-helix transitions. The modest structural change induced by the subsequent Ser45 diphosphorylation monophosphorylated Ser35 free head facilitates full helix P extension into a single structurally stable α-helix through a network of intra-domain salt bridges (pS35/R38,R39,R42). We conclude that tarantula thick filament activation is controlled by sequential Ser35-Ser45 phosphorylation via a conserved disorder-to-order transition.

  5. Why There Are No Elliptical Galaxies More Flattened Than E7. Thirty Years Later

    NASA Astrophysics Data System (ADS)

    Caimmi, R.

    2006-12-01

    Elliptical galaxies are modelled as homeoidally striated Jacobi ellipsoids (Caimmi and Marmo 2005) where the peculiar velocity distribution is anisotropic, or equivalently as their adjoint configurations i.e. classical Jacobi ellipsoids of equal mass and axes, in real or imaginary rotation (Caimmi 2006). Reasons for the coincidence of bifurcation points from axisymmetric to triaxial configurations in both the sequences (Caimmi 2006), contrary to earlier findings (Wiegandt 1982a,b, Caimmi and Marmo 2005) are presented and discussed. The effect of centrifugal support at the ends of the major equatorial axis is briefly outlined. The existence of a lower limit to the flattening of elliptical galaxies is investigated in dealing with a number of limiting situations. More specifically, (i) elliptical galaxies are considered as isolated systems, and an allowed region within Ellipsoidland (Hunter and de Zeeuw 1997), related to the occurrence of bifurcation points from ellipsoidal to pear-shaped configurations, is shown to be consistent with observations; (ii) elliptical galaxies are considered as embedded within dark matter haloes and, under reasonable assumptions, it is shown that tidal effects from hosting haloes have little influence on the above mentioned results; (iii) dark matter haloes and embedded elliptical galaxies, idealized as a single homeoidally striated Jacobi ellipsoid, are considered in connection with the cosmological transition from expansion to relaxation, by generalizing an earlier model (Thuan and Gott 1975), and the existence of a lower limit to the flattening of relaxed (oblate-like) configurations, is established. On the other hand, no lower limit is found to the elongation of relaxed (prolate-like) configurations, and the existence of some sort of instability is predicted, owing to the observed lack of elliptical galaxies more flattened or elongated than E7.

  6. Myf5 and Myogenin in the development of thymic myoid cells - Implications for a murine in vivo model of myasthenia gravis.

    PubMed

    Hu, Bo; Simon-Keller, Katja; Küffer, Stefan; Ströbel, Philipp; Braun, Thomas; Marx, Alexander; Porubsky, Stefan

    2016-03-01

    Myasthenia gravis (MG) is caused by autoantibodies against the neuromuscular junction of striated muscle. Most MG patients have autoreactive T- and B-cells directed to the acetylcholine receptor (AChR). To achieve immunologic tolerance, developing thymocytes are normally eliminated after recognition of self-antigen-derived peptides. Presentation of muscle-specific antigens is likely achieved through two pathways: on medullary thymic epithelial cells and on medullary dendritic cells cross-presenting peptides derived from a unique population of thymic myoid cells (TMC). Decades ago, it has been hypothesized that TMC play a key role in the induction of immunological tolerance towards skeletal muscle antigens. However, an experimental model to address this postulate has not been available. To generate such a model, we tested the hypothesis that the development of TMC depends on myogenic regulatory factors. To this end, we utilized Myf5-deficient mice, which lack the first wave of muscle cells but form normal skeletal muscles later during development, and Myogenin-deficient mice, which fail to form differentiated myofibers. We demonstrate for the first time that Myf5- and Myogenin-deficient mice showed a partial or complete, respectively, loss of TMC in an otherwise regularly structured thymus. To overcome early postnatal lethality of muscle-deficient, Myogenin-knockout mice we transplanted Myogenin-deficient fetal thymuses into Foxn1(nu/nu) mice that lack their own thymus anlage. We found that the transplants are functional but lack TMC. In combination with established immunization strategies (utilizing AChR or Titin), this model should enable us in the future testing the hypothesis that TMC play an indispensable role in the development of central tolerance towards striated muscle antigens. PMID:26708556

  7. Dissecting Oceanic Detachment Faults: Fault Zone Geometry, Deformation Mechanisms, and Nature of Fluid-Rock Interactions

    NASA Astrophysics Data System (ADS)

    Bonnemains, D.; Escartin, J.; Verlaguet, A.; Andreani, M.; Mevel, C.

    2015-12-01

    To understand the extreme strain localization at long-lived oceanic detachment faults rooting deeply below the axis, we present results of geological investigations at the 13°19'N detachment along the Mid-Atlantic Ridge, conducted during the ODEMAR cruise (Nov-Dec13, NO Pourquoi Pas?) with ROV Victor6000 (IFREMER). During this cruise we investigated and sampled the corrugated fault to understand its geometry, nature of deformation, and links to fluid flow. We identified and explored 7 fault outcrops on the flanks of microbathymetric striations subparallel to extension. These outcrops expose extensive fault planes, with the most prominent ones extending 40-90m laterally, and up to 10 m vertically. These fault surfaces systematically show subhorizontal striations subparallel to extension, and define slabs of fault-rock that are flat and also striated at sample scale. Visual observations show a complex detachment fault zone, with anastomosing fault planes at outcrop scale (1-10 m), with a highly heterogeneous distribution of deformation. We observe heterogeneity in fault-rock nature at outcrop scale. In situ samples from striated faults are primarily basalt breccias with prior green-schist facies alteration, and a few ultramafic fault-rocks that show a complex deformation history, with early schistose textures, brittlely reworked as clasts within the fault. The basalt breccias show variable silicification and associated sulfides, recording important fluid-rock interactions during exhumation. To understand the link between fluid and deformation during exhumation, we will present microstructural observation of deformation textures, composition, and distribution and origin of quartz and sulfides, as well as constraints on the temperature of silicifying fluids from fluid inclusions in quartz. These results allow us to characterize in detail the detachment fault zone geometry, and investigate the timing of silicification relative to deformation.

  8. A role for the dystrophin-glycoprotein complex as a transmembrane linker between laminin and actin

    PubMed Central

    1993-01-01

    The dystrophin-glycoprotein complex was tested for interaction with several components of the extracellular matrix as well as actin. The 156-kD dystrophin-associated glycoprotein (156-kD dystroglycan) specifically bound laminin in a calcium-dependent manner and was inhibited by NaCl (IC50 = 250 mM) but was not affected by 1,000-fold (wt/wt) excesses of lactose, IKVAV, or YIGSR peptides. Laminin binding was inhibited by heparin (IC50 = 100 micrograms/ml), suggesting that one of the heparin-binding domains of laminin is involved in binding dystroglycan while negatively charged oligosaccharide moieties on dystroglycan were found to be necessary for its laminin-binding activity. No interaction between any component of the dystrophin- glycoprotein complex and fibronectin, collagen I, collagen IV, entactin, or heparan sulfate proteoglycan was detected by 125I-protein overlay and/or extracellular matrix protein-Sepharose precipitation. In addition, laminin-Sepharose quantitatively precipitated purified dystrophin-glycoprotein complex, demonstrating that the laminin-binding site is accessible when dystroglycan is associated with the complex. Dystroglycan of nonmuscle tissues also bound laminin. However, the other proteins of the striated muscle dystrophin-glycoprotein complex appear to be absent, antigenically dissimilar or less tightly associated with dystroglycan in nonmuscle tissues. Finally, we show that the dystrophin-glycoprotein complex cosediments with F-actin but does not bind calcium or calmodulin. Our results support a role for the striated muscle dystrophin-glycoprotein complex in linking the actin- based cytoskeleton with the extracellular matrix. Furthermore, our results suggest that dystrophin and dystroglycan may play substantially different functional roles in nonmuscle tissues. PMID:8349731

  9. Procyrnea chabaud, 1958 (Nematoda: Habronematoidea: Habronematidae) in birds from the Area de Conservación Guanacaste, Costa Rica, including descriptions of 3 new species.

    PubMed

    Zhang, Luping; Brooks, Daniel R; Causey, Douglas

    2004-04-01

    Four species of Procyrnea were collected in birds from the Area de Conservacion Guanacaste, Costa Rica. Procyrnea brevicaudata n. sp. in Crypturellus cinnamomeus resembles P. ficheuri, P. murrayi, P. ameerae, P. dollfusi, and P. aptera in lacking lateral alae but differs from all these species in having 2 longitudinal ridges on the left side of the body, in having a sinistral rather than ventral vulvar opening, and in having dorsally bent rather than straight female tails. Procyrnea mawsonae n. sp., in Buteo magnirostris, is similar to P. strialata in body size and in having 2 transverse striated lateral alae, but differs by having longer and differently shaped spicules, and by lacking a single preanal sessile papilla. Procyrnea mclennanae n. sp., in Heliomaster constantii, is similar to P. strialata (Zhang, 1991) and P. mawsonae n. sp. in having 2 transverse striated lateral alae, but it can be distinguished from P. strialata and P. mawsonae in having 4 rather than 3 small teeth on the interior border of the pseudolabia, in having unequal rather than equal lateral alae, and in having longer spicules. Procyrnea sp., on the basis of a single adult male in Campephilus guatemalensis, resembles P. suraiyae, P. tulostoma, and P. unilateralis in possessing a single and long lateral ala, but can be distinguished from P. suraiyae and P. tulostoma in the length of the left spicule, in the left spicule having a bifid distal end, the right spicule having a rounded distal end rather than both spicules having pointed distal ends, and in having the lateral ala beginning at the lip region instead of posterior to the cervical papillae. It differs from P. uncinipenis in having a spicule ratio of 1:3.5 rather than 1:2.5, in the left spicule having a bifid rather than alate distal end, and in the absence of a single preanal papilla. PMID:15165061

  10. Structural characterization and regulatory element analysis of the heart isoform of cytochrome c oxidase VIa

    NASA Technical Reports Server (NTRS)

    Wan, B.; Moreadith, R. W.; Blomqvist, C. G. (Principal Investigator)

    1995-01-01

    In order to investigate the mechanism(s) governing the striated muscle-specific expression of cytochrome c oxidase VIaH we have characterized the murine gene and analyzed its transcriptional regulatory elements in skeletal myogenic cell lines. The gene is single copy, spans 689 base pairs (bp), and is comprised of three exons. The 5'-ends of transcripts from the gene are heterogeneous, but the most abundant transcript includes a 5'-untranslated region of 30 nucleotides. When fused to the luciferase reporter gene, the 3.5-kilobase 5'-flanking region of the gene directed the expression of the heterologous protein selectively in differentiated Sol8 cells and transgenic mice, recapitulating the pattern of expression of the endogenous gene. Deletion analysis identified a 300-bp fragment sufficient to direct the myotube-specific expression of luciferase in Sol8 cells. The region lacks an apparent TATA element, and sequence motifs predicted to bind NRF-1, NRF-2, ox-box, or PPAR factors known to regulate other nuclear genes encoding mitochondrial proteins are not evident. Mutational analysis, however, identified two cis-elements necessary for the high level expression of the reporter protein: a MEF2 consensus element at -90 to -81 bp and an E-box element at -147 to -142 bp. Additional E-box motifs at closely located positions were mutated without loss of transcriptional activity. The dependence of transcriptional activation of cytochrome c oxidase VIaH on cis-elements similar to those found in contractile protein genes suggests that the striated muscle-specific expression is coregulated by mechanisms that control the lineage-specific expression of several contractile and cytosolic proteins.

  11. Procyrnea chabaud, 1958 (Nematoda: Habronematoidea: Habronematidae) in birds from the Area de Conservación Guanacaste, Costa Rica, including descriptions of 3 new species.

    PubMed

    Zhang, Luping; Brooks, Daniel R; Causey, Douglas

    2004-04-01

    Four species of Procyrnea were collected in birds from the Area de Conservacion Guanacaste, Costa Rica. Procyrnea brevicaudata n. sp. in Crypturellus cinnamomeus resembles P. ficheuri, P. murrayi, P. ameerae, P. dollfusi, and P. aptera in lacking lateral alae but differs from all these species in having 2 longitudinal ridges on the left side of the body, in having a sinistral rather than ventral vulvar opening, and in having dorsally bent rather than straight female tails. Procyrnea mawsonae n. sp., in Buteo magnirostris, is similar to P. strialata in body size and in having 2 transverse striated lateral alae, but differs by having longer and differently shaped spicules, and by lacking a single preanal sessile papilla. Procyrnea mclennanae n. sp., in Heliomaster constantii, is similar to P. strialata (Zhang, 1991) and P. mawsonae n. sp. in having 2 transverse striated lateral alae, but it can be distinguished from P. strialata and P. mawsonae in having 4 rather than 3 small teeth on the interior border of the pseudolabia, in having unequal rather than equal lateral alae, and in having longer spicules. Procyrnea sp., on the basis of a single adult male in Campephilus guatemalensis, resembles P. suraiyae, P. tulostoma, and P. unilateralis in possessing a single and long lateral ala, but can be distinguished from P. suraiyae and P. tulostoma in the length of the left spicule, in the left spicule having a bifid distal end, the right spicule having a rounded distal end rather than both spicules having pointed distal ends, and in having the lateral ala beginning at the lip region instead of posterior to the cervical papillae. It differs from P. uncinipenis in having a spicule ratio of 1:3.5 rather than 1:2.5, in the left spicule having a bifid rather than alate distal end, and in the absence of a single preanal papilla.

  12. Anion exchanger immunoreactivity in human salivary glands in health and Sjögren's syndrome.

    PubMed Central

    Vázquez, J. J.; Vázquez, M.; Idoate, M. A.; Montuenga, L.; Martínez-Ansó, E.; Castillo, J. E.; García, N.; Medina, J. F.; Prieto, J.

    1995-01-01

    Salivary gland ducts play a relevant role in saliva secretion through transport processes. Na(+)-independent chloride-bicarbonate anion exchangers (AE) may be involved in these processes by generating ion fluxes into the salivary secretion. In Sjögren's syndrome, a disorder with gland dysfunction, there might be an impaired expression of AE proteins. Here we study AE immunoreactivities in human salivary glands, both in health and in Sjögren's syndrome. Immunohistochemistry was carried out on salivary glands from normal subjects and patients with Sjögren's syndrome, using two monoclonal antibodies against AE1 and AE2. Normal salivary glands showed AE2 immunoreactivity, which was restricted to the epithelium of the ducts, with no staining at the acini. A strong positivity was seen in the basolateral portion of the striated ducts, while interlobular duct cells showed a discrete positivity at their apical pole. In salivary glands from most of the patients with Sjögren's syndrome, AE2 immunoreactivity was absent in the ducts as well as in the acini. In both normal and diseased salivary glands, AE1 immunoreactivity was only located at the erythrocyte membrane. The recently reported AE0 was discarded because no AE0 message was found in salivary glands by reverse transcription polymerase chain reaction. In conclusion, AE2 immunoreactivity is observed in the ducts of normal salivary glands, particularly in the striated ducts. AE2 immunoreactivity is virtually absent in salivary glands from patients with Sjögren's syndrome, which may reflect either a loss of AE2 after inflammatory atrophy, or a primary defect occurring in the disease. Images Figure 2 Figure 3 Figure 4 Figure 5 PMID:7778681

  13. Sequential myosin phosphorylation activates tarantula thick filament via a disorder-order transition.

    PubMed

    Espinoza-Fonseca, L Michel; Alamo, Lorenzo; Pinto, Antonio; Thomas, David D; Padrón, Raúl

    2015-08-01

    Phosphorylation of myosin regulatory light chain (RLC) N-terminal extension (NTE) activates myosin in thick filaments. RLC phosphorylation plays a primary regulatory role in smooth muscles and a secondary (modulatory) role in striated muscles, which is regulated by Ca(2+)via TnC/TM on the thin filament. Tarantula striated muscle exhibits both regulatory systems: one switches on/off contraction through thin filament regulation, and another through PKC constitutively Ser35 phosphorylated swaying free heads in the thick filaments that produces quick force on twitches regulated from 0 to 50% and modulation is accomplished recruiting additional force-potentiating free and blocked heads via Ca(2+)4-CaM-MLCK Ser45 phosphorylation. We have used microsecond molecular dynamics (MD) simulations of tarantula RLC NTE to understand the structural basis for phosphorylation-based regulation in tarantula thick filament activation. Trajectory analysis revealed that an inter-domain salt bridge network (R39/E58,E61) facilitates the formation of a stable helix-coil-helix (HCH) motif formed by helices P and A in the unphosphorylated NTE of both myosin heads. Phosphorylation of the blocked head on Ser45 does not induce any substantial structural changes. However, phosphorylation of the free head on Ser35 disrupts this salt bridge network and induces a partial extension of helix P along RLC helix A. While not directly participating in the HCH folding, phosphorylation of Ser35 unlocks a compact structure and allows the NTE to spontaneously undergo coil-helix transitions. The modest structural change induced by the subsequent Ser45 diphosphorylation monophosphorylated Ser35 free head facilitates full helix P extension into a single structurally stable α-helix through a network of intra-domain salt bridges (pS35/R38,R39,R42). We conclude that tarantula thick filament activation is controlled by sequential Ser35-Ser45 phosphorylation via a conserved disorder-to-order transition. PMID

  14. Loss of the Tectorial Membrane Protein CEACAM16 Enhances Spontaneous, Stimulus-Frequency, and Transiently Evoked Otoacoustic Emissions

    PubMed Central

    Goodyear, Richard J.; Homma, Kazuaki; Legan, P. Kevin; Korchagina, Julia; Naskar, Souvik; Siegel, Jonathan H.; Dallos, Peter; Zheng, Jing

    2014-01-01

    α-Tectorin (TECTA), β-tectorin (TECTB), and carcinoembryonic antigen-related cell adhesion molecule 16 (CEACAM) are secreted glycoproteins that are present in the tectorial membrane (TM), an extracellular structure overlying the hearing organ of the inner ear, the organ of Corti. Previous studies have shown that TECTA and TECTB are both required for formation of the striated-sheet matrix within which collagen fibrils of the TM are imbedded and that CEACAM16 interacts with TECTA. To learn more about the structural and functional significance of CEACAM16, we created a Ceacam16-null mutant mouse. In the absence of CEACAM16, TECTB levels are reduced, a clearly defined striated-sheet matrix does not develop, and Hensen's stripe, a prominent feature in the basal two-thirds of the TM in WT mice, is absent. CEACAM16 is also shown to interact with TECTB, indicating that it may stabilize interactions between TECTA and TECTB. Although brain-stem evoked responses and distortion product otoacoustic emissions are, for most frequencies, normal in young mice lacking CEACAM16, stimulus-frequency and transiently evoked emissions are larger. We also observed spontaneous otoacoustic emissions (SOAEs) in 70% of the homozygous mice. This incidence is remarkable considering that <3% of WT controls have SOAEs. The predominance of SOAEs >15 kHz correlates with the loss of Hensen's stripe. Results from mice lacking CEACAM16 are consistent with the idea that the organ of Corti evolved to maximize the gain of the cochlear amplifier while preventing large oscillations. Changes in TM structure appear to influence the balance between energy generation and dissipation such that the system becomes unstable. PMID:25080593

  15. Pituitary adenylate cyclase-activating polypeptide enhances saliva secretion via direct binding to PACAP receptors of major salivary glands in mice.

    PubMed

    Matoba, Yuko; Nonaka, Naoko; Takagi, Yoshitoki; Imamura, Eisaku; Narukawa, Masayuki; Nakamachi, Tomoya; Shioda, Seiji; Banks, William A; Nakamura, Masanori

    2016-09-01

    Xerostomia, or dry mouth, is a common syndrome that is generally treated with artificial saliva; however, no other effective methods have yet been established. Saliva secretion is mainly under the control of the autonomic nervous system. Pituitary adenylate cyclase-activating polypeptide (PACAP) is recognized as a multifunctional neuropeptide in various organs. In this study, we examined the effect of PACAP on saliva secretion, and detected the distribution of the PACAP type 1 receptor (PAC1R) in major salivary glands, including the parotid, submandibular, and sublingual glands, in 9-week-old male C57BL/6 mice. Intranasal administration of PACAP 38 increased the amount of saliva secreted, which was not inhibited by atropine pretreatment. Immunohistochemical analysis showed that PAC1R was distributed in the three major salivary glands. In the parotid and sublingual glands, PAC1R was detected in striated duct cells, whereas in the submandibular gland, a strong PAC1R immunoreaction was detected in tall columnar epithelial cells in the granular ducts (i.e., pillar cells), as well as in some striated duct cells. PACAP significantly increased the concentration of epidermal growth factor in saliva. These results suggest that PACAP directly regulates saliva secretion by controlling the absorption activity in the ducts, and that pillar cells regulate the function of granular epithelial cells in the granular duct, such as the secretion of growth factors into the saliva. Collectively, these results suggest the possibility of PACAP as a new effective treatment of xerostomia. Anat Rec, 299:1293-1299, 2016. © 2016 Wiley Periodicals, Inc. PMID:27339371

  16. Independent specialisation of myosin II paralogues in muscle vs. non-muscle functions during early animal evolution: a ctenophore perspective

    PubMed Central

    2012-01-01

    Background Myosin II (or Myosin Heavy Chain II, MHCII) is a family of molecular motors involved in the contractile activity of animal muscle cells but also in various other cellular processes in non-muscle cells. Previous phylogenetic analyses of bilaterian MHCII genes identified two main clades associated respectively with smooth/non-muscle cells (MHCIIa) and striated muscle cells (MHCIIb). Muscle cells are generally thought to have originated only once in ancient animal history, and decisive insights about their early evolution are expected to come from expression studies of Myosin II genes in the two non-bilaterian phyla that possess muscles, the Cnidaria and Ctenophora. Results We have uncovered three MHCII paralogues in the ctenophore species Pleurobrachia pileus. Phylogenetic analyses indicate that the MHCIIa / MHCIIb duplication is more ancient than the divergence between extant metazoan lineages. The ctenophore MHCIIa gene (PpiMHCIIa) has an expression pattern akin to that of "stem cell markers" (Piwi, Vasa…) and is expressed in proliferating cells. We identified two MHCIIb genes that originated from a ctenophore-specific duplication. PpiMHCIIb1 represents the exclusively muscular form of myosin II in ctenophore, while PpiMHCIIb2 is expressed in non-muscle cells of various types. In parallel, our phalloidin staining and TEM observations highlight the structural complexity of ctenophore musculature and emphasize the experimental interest of the ctenophore tentacle root, in which myogenesis is spatially ordered and strikingly similar to striated muscle formation in vertebrates. Conclusion MHCIIa expression in putative stem cells/proliferating cells probably represents an ancestral trait, while specific involvement of some MHCIIa genes in smooth muscle fibres is a uniquely derived feature of the vertebrates. That one ctenophore MHCIIb paralogue (PpiMHCIIb2) has retained MHCIIa-like expression features furthermore suggests that muscular expression of the

  17. Biochemical characterization of the mouse muscle-specific enolase: developmental changes in electrophoretic variants and selective binding to other proteins.

    PubMed Central

    Merkulova, T; Lucas, M; Jabet, C; Lamandé, N; Rouzeau, J D; Gros, F; Lazar, M; Keller, A

    1997-01-01

    The glycolytic enzyme enolase (EC 4.2.1.11) is active as dimers formed from three subunits encoded by different genes. The embryonic alphaalpha isoform remains distributed in many adult cell types, whereas a transition towards betabeta and gammagamma isoforms occurs in striated muscle cells and neurons respectively. It is not understood why enolase exhibits tissue-specific isoforms with very close functional properties. We approached this problem by the purification of native betabeta-enolase from mouse hindlimb muscles and by raising specific antibodies of high titre against this protein. These reagents have been useful in revealing a heterogeneity of the beta-enolase subunit that changes with in vivo and in vitro maturation. A basic carboxypeptidase appears to be involved in generating an acidic beta-enolase variant, and may regulate plasminogen binding by this subunit. We show for the first time that pure betabeta-enolase binds with high affinity the adjacent enzymes in the glycolytic pathway (pyruvate kinase and phosphoglycerate mutase), favouring the hypothesis that these three enzymes form a functional glycolytic segment. betabeta-Enolase binds with high affinity sarcomeric troponin but not actin and tropomyosin. Some of these binding properties are shared by the alphaalpha-isoenolase, which is also expressed in striated muscle, but not by the neuron-specific gammagamma-enolase. These results support the idea that specific interactions with macromolecules will address muscle enolase isoforms at the subcellular site where ATP, produced through glycolysis, is most needed for contraction. Such a specific targeting could be modulated by post-translational modifications. PMID:9169614

  18. Endopolyploidy Changes with Age-Related Polyethism in the Honey Bee, Apis mellifera

    PubMed Central

    Rangel, Juliana; Strauss, Kim; Seedorf, Kaileah; Hjelmen, Carl E.; Johnston, J. Spencer

    2015-01-01

    Honey bees (Apis mellifera) exhibit age polyethism, whereby female workers assume increasingly complex colony tasks as they age. While changes in DNA methylation accompany age polyethism, other DNA modifications accompanying age polyethism are less known. Changes in endopolyploidy (DNA amplification in the absence of cell division) with increased larval age are typical in many insect cells and are essential in adults for creating larger cells, more copies of essential loci, or greater storage capacity in secretory cells. However, changes in endopolyploidy with increased adult worker age and polyethism are unstudied. In this study, we examined endopolyploidy in honey bee workers ranging in age from newly emerged up to 55 days old. We found a nonsignificant increase in ploidy levels with age (P < 0.1) in the most highly endopolyploid secretory cells, the Malpighian tubules. All other cell types decreased ploidy levels with age. Endopolyploidy decreased the least amount (nonsignificant) in neural (brain) cells and the stinger (P < 0.1). There was a significant reduction of endopolyploidy with age in leg (P < 0.05) and thoracic (P < 0.001) muscles. Ploidy in thoracic muscle dropped from an average of 0.5 rounds of replication in newly emerged workers to essentially no rounds of replication (0.125) in the oldest workers. Ploidy reduction in flight muscle cells is likely due to the production of G1 (2C) nuclei by amitotic division in the multinucleate striated flight muscles that are essential to foragers, the oldest workers. We suggest that ploidy is constrained by the shape, size and makeup of the multinucleate striated muscle cells. Furthermore, the presence of multiple 2C nuclei might be optimal for cell function, while higher ploidy levels might be a dead-end strategy of some aging adult tissues, likely used to increase cell size and storage capacity in secretory cells. PMID:25881205

  19. Myf5 and Myogenin in the development of thymic myoid cells - Implications for a murine in vivo model of myasthenia gravis.

    PubMed

    Hu, Bo; Simon-Keller, Katja; Küffer, Stefan; Ströbel, Philipp; Braun, Thomas; Marx, Alexander; Porubsky, Stefan

    2016-03-01

    Myasthenia gravis (MG) is caused by autoantibodies against the neuromuscular junction of striated muscle. Most MG patients have autoreactive T- and B-cells directed to the acetylcholine receptor (AChR). To achieve immunologic tolerance, developing thymocytes are normally eliminated after recognition of self-antigen-derived peptides. Presentation of muscle-specific antigens is likely achieved through two pathways: on medullary thymic epithelial cells and on medullary dendritic cells cross-presenting peptides derived from a unique population of thymic myoid cells (TMC). Decades ago, it has been hypothesized that TMC play a key role in the induction of immunological tolerance towards skeletal muscle antigens. However, an experimental model to address this postulate has not been available. To generate such a model, we tested the hypothesis that the development of TMC depends on myogenic regulatory factors. To this end, we utilized Myf5-deficient mice, which lack the first wave of muscle cells but form normal skeletal muscles later during development, and Myogenin-deficient mice, which fail to form differentiated myofibers. We demonstrate for the first time that Myf5- and Myogenin-deficient mice showed a partial or complete, respectively, loss of TMC in an otherwise regularly structured thymus. To overcome early postnatal lethality of muscle-deficient, Myogenin-knockout mice we transplanted Myogenin-deficient fetal thymuses into Foxn1(nu/nu) mice that lack their own thymus anlage. We found that the transplants are functional but lack TMC. In combination with established immunization strategies (utilizing AChR or Titin), this model should enable us in the future testing the hypothesis that TMC play an indispensable role in the development of central tolerance towards striated muscle antigens.

  20. Cellular and humoral immune abnormalities in Gulf War veterans.

    PubMed Central

    Vojdani, Aristo; Thrasher, Jack D

    2004-01-01

    We examined 100 symptomatic Gulf War veterans (patients) and 100 controls for immunologic assays. The veterans and controls were compared for the percentage of T cells (CD3); B cells (CD19); helper:suppressor (CD4:CD8) ratio; natural killer (NK) cell activity; mitogenic response to phytohemagglutin (PHA) and pokeweed mitogen (PWM); level of immune complexes; myelin basic protein (MBP) and striated and smooth muscle autoantibodies; and antibodies against Epstein-Barr virus, cytomegalovirus, herpes simplex virus type 1 (HSV-1), HSV-2, human herpes Type 6 (HHV-6), and Varicella zoster virus (VZV). The percentage of T cells in patients versus controls was not significantly different, whereas a significantly higher proportion of patients had elevated T cells compared with controls. The percentage of B cells was significantly elevated in the patients versus the controls. The NK cell (NK) activity was significantly decreased in the patients (24.8 +/- 16.5 lytic units) versus the controls (37.3 +/- 26.4 lytic units). The percentage of patients with lower than normal response to PHA and PWM was significantly different from controls. Immune complexes were significantly increased in the patients (53.1 +/- 18.6, mean +/- SD) versus controls (34.6 +/- 14.3). Autoantibody titers directed against MBP and striated or smooth muscle were significantly greater in patients versus controls. Finally, the patients had significantly greater titers of antibodies to the viruses compared with the controls (p < 0.001). These immune alterations were detected 2-8 years after participation in the Gulf War. The immune alterations are consistent with exposure to different environmental factors. We conclude that Gulf War syndrome is a multifaceted illness with immune function alterations that may be induced by various factors and are probably associated with chronic fatigue syndrome. PMID:15175170

  1. A Novel Basal Apparatus Protein of 90 kD (BAp90) from the Flagellate Green Alga Spermatozopsis similis is a Component of the Proximal Plates and Identifies the d-(dexter)Surface of the Basal Body.

    PubMed

    Geimer, S; Lechtreck, K F; Melkonian, M

    1998-05-01

    The flagellar basal apparatus consists of the basal bodies and associated fibrous structures, and represents the organizing center for the microtubular cytoskeleton in many flagellate protists. To identify novel proteins associated with the basal bodies, basal apparatuses from the flagellate green alga Spermatozopsis similis (Chlorophyceae) were isolated and purified. A polyclonal antibody raised against a 95kD protein band enriched in purified basal apparatuses was used to screen a cDNA library of S. similis which resulted in the isolation of a full length clone coding for a novel protein of 812 amino acids (85.3kD). Sequence analysis of this clone identified extended a-helical regions and predicted several coiled-coil forming domains interrupted by spacer segments of variable lengths. A polyclonal antibody (anti-BAp90) raised against the bacterially expressed protein recognized a 90kD band (BAp90) in SDS-PAGE of isolated basal apparatuses of S. similis. Immunogold labeling using anti-BAp90 decorated the proximal plates (two striated, triangular fibers which serve as spacers between the basal bodies in their proximal region) and parts of the d-fibers (df) which interconnect the basal bodies with the microtubular d-roots and the striated microtubule-associated fibers (SMAFs). Thus, the 90kD basal apparatus protein of S. similis represents a biochemical landmark for the lateral asymmetry of the basal body identifying its d-(dexter)surface. Cytoskeletal elements containing BAp90 or structurally related proteins may be involved in the organization and/or maintenance of the positional relationship between basal bodies and the cellular cytoskeleton, and hence cell polarity.

  2. Functional roles of capsaicin-sensitive intrinsic neural circuit in the regulation of esophageal peristalsis in rats: in vivo studies using a novel method.

    PubMed

    Shima, Takeshi; Shiina, Takahiko; Naitou, Kiyotada; Nakamori, Hiroyuki; Shimizu, Yasutake

    2014-05-01

    A well-developed myenteric plexus exists in the esophagus composed of striated muscle layers, but its functional role in controlling peristaltic movements remains to be clarified. The purpose of this study was to clarify the role of a local neural reflex consisting of capsaicin-sensitive primary afferent neurons and intrinsic neurons in esophageal peristalsis. We firstly devised a method to measure peristaltic movement of esophagus in vivo in rats. Rats were anesthetized with urethane, and esophageal intraluminal pressure and propelled intraluminal liquid volume were recorded. In the experimental system, an intraluminal pressure stimulus evoked periodic changes in intraluminal pressure of the esophagus, which were consistently accompanied by intraluminal liquid propulsion. Bilateral vagotomy abolished changes in intraluminal pressure as well as liquid propulsion. These results indicate that the novel method is appropriate for inducing peristalsis in the esophagus composed of striated muscles. Then, by using the method, we examined functional roles of the local reflex in esophageal peristalsis. For that purpose, we used rats in which capsaicin-sensitive neurons had been destroyed. The esophagus of capsaicin-treated rats showed a multiphasic rise in intraluminal pressure, which may due to noncoordinated contractions of esophageal muscles, whereas a monophasic response was observed in the intact rat esophagus. In addition, destruction of capsaicin-sensitive neurons increased the propelled liquid volume and lowered the pressure threshold for initiating peristalsis. These results suggest that the local neural reflex consisting of capsaicin-sensitive neurons and intrinsic neurons contributes to coordination of peristalsis and suppresses mechanosensory function of vagal afferents in the esophagus.

  3. A discrepancy within primate spatial vision and its bearing on the definition of edge detection processes in machine vision

    NASA Technical Reports Server (NTRS)

    Jobson, Daniel J.

    1990-01-01

    The visual perception of form information is considered to be based on the functioning of simple and complex neurons in the primate striate cortex. However, a review of the physiological data on these brain cells cannot be harmonized with either the perceptual spatial frequency performance of primates or the performance which is necessary for form perception in humans. This discrepancy together with recent interest in cortical-like and perceptual-like processing in image coding and machine vision prompted a series of image processing experiments intended to provide some definition of the selection of image operators. The experiments were aimed at determining operators which could be used to detect edges in a computational manner consistent with the visual perception of structure in images. Fundamental issues were the selection of size (peak spatial frequency) and circular versus oriented operators (or some combination). In a previous study, circular difference-of-Gaussian (DOG) operators, with peak spatial frequency responses at about 11 and 33 cyc/deg were found to capture the primary structural information in images. Here larger scale circular DOG operators were explored and led to severe loss of image structure and introduced spatial dislocations (due to blur) in structure which is not consistent with visual perception. Orientation sensitive operators (akin to one class of simple cortical neurons) introduced ambiguities of edge extent regardless of the scale of the operator. For machine vision schemes which are functionally similar to natural vision form perception, two circularly symmetric very high spatial frequency channels appear to be necessary and sufficient for a wide range of natural images. Such a machine vision scheme is most similar to the physiological performance of the primate lateral geniculate nucleus rather than the striate cortex.

  4. Cerebral color blindness: an acquired defect in hue discrimination.

    PubMed

    Pearlman, A L; Birch, J; Meadows, J C

    1979-03-01

    In contrast to the traditional view that striate visual cortex (area 17) is surrounded by two homogeneous cortical areas (areas 18 and 19), recent studies have shown that mammalian extrastriate visual cortex contains several anatomically and functionally distinct subregions. One such region, the V-4 complex of the rhesus monkey, is highly specialized for the analysis of color information, suggesting that a lesion in a homologous region might produce a defect in color vision while sparing other visual functions. We have studied a patient whose clinical syndrome supports this suggestion: a 44-year-old man with normal color vision suffered two cerebral infarctions that produced first a right and then a left superior homonymous quadrantanopia and also caused prosopagnosia, topographical disorientation, and severely impaired color vision. Computed tomography demonstrated extensive lesions in both inferior occipital lobes in the territories of the lateral branches of the posterior cerebral arteries, involving the lingual and medial occipitotemporal gyri bilaterally; these gyri contain the inferior portion of striate cortex and segments of extrastriate visual cortex. The patient had no difficulty in giving the correct color names associated with common objects presented either verbally or in outline drawings. Standardized testing with the Farnsworth-Munsell 100-hue test, the Nagel anomaloscope, and a method that tests for just-noticeable differences between monochromatic stimuli all showed that the patient's ability to distinguish one color from another was markedly imparied but not totally absent. In contrast, visual acuity, reading, visually guided eye movements, and stereopsis were normal. Cells in the V-4 complex of monkey extrastriate cortex are highly specialized for distinguishing one color from another; the hue discrimination deficit that was demonstrated in this patient with cerebral color blindness indicates that a region or regions with similar function has

  5. [Immunohistochemical study on the mechanism of excretion of methamphetamine].

    PubMed

    Kajitani, A; Kaiho, M; Mori, A; Okada, Y; Mukaida, M; Ishiyama, I

    1989-06-01

    Many methods of analysis are available to the forensic toxicologist for determining the amount of methamphetamine within human tissues, but few have the potential of histochemistry for enabling the precise site of excretion of methamphetamine to be defined. We have established a method for the demonstration of methamphetamine by immunohistochemistry, and applied this method for showing morphologically the disposition of methamphetamine. The following cells in the tissues of methamphetamine-intoxicated mice gave a strong positive reaction of the localization, which was thought to be the histological evidence of excretion of this drug: epithelial cells of the distal part of the renal tubule and of the collecting tubule, transitional epithelial cells of the bladder, liver parenchymal cells, epithelial cells of the striated duct of the salivary gland, parietal cells of the gastric gland, part of epithelial cells of the distal portion of the large intestine, secretory cells and part of epithelial cells of the ductal portion of the sweat gland, alveolar cells of the mammary gland, secretory cells of the sebaceous gland and hair medulla and cortex. These results indicated passive diffusion of methamphetamine across membranes of the cells of the distal tubule and collecting tubule of the kidney, of the bladder and of the striated duct of the salivary gland. In the parietal cells of the gastric gland, part of epithelial cells of the distal portion of the large intestine and secretory cells of the sweat gland, methamphetamine was thought to be stored and subsequently released. In the mammary gland, methamphetamine was found to be combined with casein and excreted by exocytosis. Accumulation of methamphetamine in the hair was supposed to be chiefly due to the penetration of this drug derived from tissue fluid and sebum.

  6. Persistence of the synaptosomal-associated protein-25 cleavage product after intradetrusor botulinum toxin A injections in patients with myelomeningocele showing an inadequate response to treatment.

    PubMed

    Schulte-Baukloh, Heinrich; Zurawski, Tomas H; Knispel, Helmut H; Miller, Kurt; Haferkamp, Axel; Dolly, J Oliver

    2007-11-01

    OBJECTIVE To monitor the presence and cleavage of synaptosomal-associated protein of 25 kDa (SNAP-25) by botulinum toxin type A (botox-A), in human detrusor muscle, as the effects of botox-A in the urinary bladder last significantly longer than when applied for disorders of striated muscles. PATIENTS AND METHODS Tissue samples were obtained from eight patients with end-stage neurogenic bladder at different times after injection with botox-A. The resected bladder domes were examined using biochemical and immunohistological techniques. RESULTS The presence of intact SNAP-25 in human bladder was detected, for the first time, in all samples by both Western blotting and immunofluorescence. By contrast, detection of a band potentially representing toxin-cleaved SNAP-25(A) required its enrichment by precipitation with a specific antibody. This putative product was present in four of six patients treated with botox-A 5 weeks to 11 months previously, but could not be detected in one patient 30 months after botox injection, and in an untreated control. Fluorescence microscopy showed no obvious effects of the toxin treatment on the presence and pattern of SNAP-25-positive neurones. CONCLUSIONS A limited amount of SNAP-25 appears to be cleaved in nerves that innervate the smooth detrusor muscle in most patients who had been injected with botox-A; its absolute identification was precluded by the sensitivity of the detection. This protein was detectable much longer after toxin treatment than published for rodent striated muscle, and thus could contribute to the clinically reported longer duration of the effectiveness of botox-A.

  7. A Common Disease-Associated Missense Mutation in Alpha-Sarcoglycan Fails to Cause Muscular Dystrophy in Mice

    PubMed Central

    Kobuke, Kazuhiro; Piccolo, Federica; Garringer, Keith W.; Moore, Steven A.; Sweezer, Eileen; Yang, Baoli; Campbell, Kevin P.

    2009-01-01

    Limb-girdle muscular dystrophy type 2D (LGMD2D) is caused by autosomal recessive mutations in the α-sarcoglycan gene. An R77C substitution is the most prevalent cause of the disease, leading to disruption of the sarcoglycan-sarcospan complex. To model this common mutation, we generated knock-in mice with an H77C substitution in α-sarcoglycan. The floxed neomycin (Neo)-cassette retained at the targeted H77C α-sarcoglycan locus caused a loss of α-sarcoglycan expression, resulting in muscular dystrophy in homozygotes, whereas Cre-mediated deletion of the floxed Neo-cassette led to recovered H77C α-sarcoglycan expression. Contrary to expectations, mice homozygous for the H77C-encoding allele expressed both this mutant α-sarcoglycan and the other components of the sarcoglycan-sarcospan complex in striated muscle, and did not develop muscular dystrophy. Accordingly, conditional rescued expression of the H77C protein in striated muscle of the α-sarcoglycan-deficient mice prevented the disease. Adding to the case that the behavior of mutant α-sarcoglycan is different between humans and mice, mutant human R77C α-sarcoglycan restored the expression of the sarcoglycan-sarcospan complex when introduced by adenoviral vector into the skeletal muscle of previously created α-sarcoglycan null mice. These findings indicate that the α-sarcoglycan with the most frequent missense mutation in LGMD2D is correctly processed, is transported to the sarcolemma, and is fully functional in mouse muscle. Our study presents an unexpected difference in the behavior of a missense-mutated protein in mice versus human patients, and emphasizes the need to understand species-specific protein quality control systems. PMID:18252746

  8. Five new species of the genus Tripylella (Nematoda: Enoplida: Tripylidae).

    PubMed

    Prado-Vera, Ignacio Cid Del; Ferris, Howard; Nadler, Steven A

    2016-01-01

    Five new species of the genus Tripylella are described, two from México, one from Fátima, Portugal, one from Quito, Ecuador, and one from California, USA. Tripylella mexicana sp. n. is characterized by its short body (average 0.74 mm), short pharynx (average 161 μm), short tail (average 117 μm), presence of an excretory pore and small setae distributed sparsely along the body, the presence of body pores, the posterior position of the subventral teeth in relation to the small dorsal tooth with all teeth in contiguous stomal chambers, the finely-striated cuticle with many anastomoses, the non-protruding vulval lips, and the presence of sclerotized pieces in the vulval region. Tripylella muscusi sp. n. is characterized by its body length (average 0.94 mm), pharynx length (average 201 μm), tail length (average 140 μm), the anterior position of the subventral teeth in relation to the small dorsal tooth in a single stomal chamber, the presence of an excretory pore, the presence of body pores and sparse somatic setae, the finely-striated cuticle with sparse anastomoses, protruding vulval lips and sclerotized oval-shaped pieces present in the vulval region. Tripylella quitoensis sp. n. is characterized by the short body length (average 0.72 mm), the short outer labial setae, the short pharynx (average 175 μm), the location of the anterior subventral teeth and posterior dorsal tooth in the same stomal chamber, the short tail (average 98 μm), the apparent absence of an excretory pore, presence of body pores, presence of somatic setae, a finely-striated cuticle, non-protruding vulval lips, and very small oval sclerotized pieces in the vulva. Tripylella fatimaensis sp. n. is characterized by the short body, (average 0.74 mm) long, by the length of the pharynx (average 180 μm), the length of the tail (average 110 μm) and in the length of its reduced diameter portion, 45-58 μm, the presence of an excretory pore, body pores and three pairs of caudal setae (one pair

  9. Buzzcut or Fossil? Exploring the Origin of Perched Low-Relief Landscapes in the Tropics

    NASA Astrophysics Data System (ADS)

    Cunningham, M.; Stark, C. P.; Kaplan, M. R.; Schaefer, J. M.

    2014-12-01

    Throughout the tropics, high mountain regions have a "buzzcut" appearance, with low-relief spines perched high (>2500m) above deeply incised ridge-and-valley topography. Many of these mountain ranges intersect the local LGM ELA, but few studies have speculated on the role glacial erosion may have played in shaping their perched, low-relief landforms. Instead, multiple studies have invoked an abrupt increase tectonic uplift that switched the orogen from a low-relief, low erosion rate regime to a high-relief, high erosion rate mode. In this model context, perched landscapes are fossil remnants of the low-erosion rate regime, and the presence of glacial/paraglacial landforms is coincidental. However, an alternative interpretation is possible: rather than a tectonically-forced switch in erosion rate regime, low-relief spines were cut by alpine glacial erosion. To assess the influence of glacial/paraglacial processes on the formation of low-relief topography in a tropical mountain range, we conducted fieldwork at Mount Chirripó (3819m), Costa Rica. At Mount Chirripó, the estimated LGM ELA is ~3500m. River profile analysis shows a conspicuous cluster of knickpoints at ~2500m, which has been used to infer a rapid increase in regional tectonic uplift between 1-2 Ma that produced high-relief landscapes fringing ancient, low-relief landscapes. As an alternative, we hypothesize that glacial/postglacial processes acting throughout the Pleistocene played a dominant role in the formation and preservation of Mount Chirripó's low-relief spine. At Mount Chirripó, we identified glacial erosion features between 3400-3800m, including moraines, striated bedrock, glacial till, glaciofluvial outwash and post-glacial landslides. Additionally, we observed a low-sloping valley floored by angular debris at ~3100m that we interpret to be of glacial origin. We collected samples for surface exposure age dating from erratics, striated bedrock, and landslide debris boulders. Mapping of

  10. Language networks in anophthalmia: maintained hierarchy of processing in 'visual' cortex.

    PubMed

    Watkins, Kate E; Cowey, Alan; Alexander, Iona; Filippini, Nicola; Kennedy, James M; Smith, Stephen M; Ragge, Nicola; Bridge, Holly

    2012-05-01

    Imaging studies in blind subjects have consistently shown that sensory and cognitive tasks evoke activity in the occipital cortex, which is normally visual. The precise areas involved and degree of activation are dependent upon the cause and age of onset of blindness. Here, we investigated the cortical language network at rest and during an auditory covert naming task in five bilaterally anophthalmic subjects, who have never received visual input. When listening to auditory definitions and covertly retrieving words, these subjects activated lateral occipital cortex bilaterally in addition to the language areas activated in sighted controls. This activity was significantly greater than that present in a control condition of listening to reversed speech. The lateral occipital cortex was also recruited into a left-lateralized resting-state network that usually comprises anterior and posterior language areas. Levels of activation to the auditory naming and reversed speech conditions did not differ in the calcarine (striate) cortex. This primary 'visual' cortex was not recruited to the left-lateralized resting-state network and showed high interhemispheric correlation of activity at rest, as is typically seen in unimodal cortical areas. In contrast, the interhemispheric correlation of resting activity in extrastriate areas was reduced in anophthalmia to the level of cortical areas that are heteromodal, such as the inferior frontal gyrus. Previous imaging studies in the congenitally blind show that primary visual cortex is activated in higher-order tasks, such as language and memory to a greater extent than during more basic sensory processing, resulting in a reversal of the normal hierarchy of functional organization across 'visual' areas. Our data do not support such a pattern of organization in anophthalmia. Instead, the patterns of activity during task and the functional connectivity at rest are consistent with the known hierarchy of processing in these areas

  11. Alcohol differentially alters extracellular matrix and adhesion molecule expression in skeletal muscle and heart

    PubMed Central

    Steiner, Jennifer L.; Pruznak, Anne M.; Navaratnarajah, Maithili; Lang, Charles H.

    2015-01-01

    Background The production of fibrosis in response to chronic alcohol abuse is well recognized in liver but has not been fully characterized in striated muscle and may contribute to functional impairment. Therefore, the purpose of this study was to use an unbiased discovery-based approach to determine the effect of chronic alcohol consumption on the expression profile of genes important for cell-cell and cell-extracellular matrix (ECM) interactions in both skeletal and cardiac muscle. Methods Adult male rats were pair-fed an alcohol-containing liquid diet or control diet for 24 wks, and skeletal muscle (gastrocnemius) and heart collected in the freely fed state. A pathway-focused gene expression PCR array was performed on these tissues to assess mRNA content for 84 ECM proteins, and selected proteins were confirmed by Western analysis. Results In gastrocnemius, alcohol feeding up-regulated expression of 11 genes and down-regulated expression of 1 gene. Alcohol increased fibrosis as indicated by increased mRNA and/or protein for collagen α1(I), α2(I), α1(III) and α2(IV) as well as hydroxyproline. Alcohol also increased α-smooth muscle actin protein, an index of myofibroblast activation, but no concomitant change in TGF-β was detected. The mRNA and protein content for other ECM components, such as integrin α-5, L-selectin, PECAM, Sparc and Adamts2 was also increased by alcohol. Only laminin α-3 mRNA was decreased in gastrocnemius from alcohol-fed rats, while 66 ECM- or cell adhesion-related mRNAs were unchanged by alcohol. For heart, expression of 16 genes was up-regulated, expression of 3 genes was down-regulated, and 65 mRNAs were unchanged by alcohol; there were no common alcohol-induced gene expression changes between heart and skeletal muscle. Finally, alcohol increased TNFα and IL-12 mRNA in both skeletal and cardiac muscle, but IL-6 mRNA was increased and IL-10 mRNA decreased only in skeletal muscle. Conclusions These data demonstrate a fibrotic

  12. Movement preparation and execution: differential functional activation patterns after traumatic brain injury.

    PubMed

    Gooijers, Jolien; Beets, Iseult A M; Albouy, Genevieve; Beeckmans, Kurt; Michiels, Karla; Sunaert, Stefan; Swinnen, Stephan P

    2016-09-01

    Years following the insult, patients with traumatic brain injury often experience persistent motor control problems, including bimanual coordination deficits. Previous studies revealed that such deficits are related to brain structural white and grey matter abnormalities. Here, we assessed, for the first time, cerebral functional activation patterns during bimanual movement preparation and performance in patients with traumatic brain injury, using functional magnetic resonance imaging. Eighteen patients with moderate-to-severe traumatic brain injury (10 females; aged 26.3 years, standard deviation = 5.2; age range: 18.4-34.6 years) and 26 healthy young adults (15 females; aged 23.6 years, standard deviation = 3.8; age range: 19.5-33 years) performed a complex bimanual tracking task, divided into a preparation (2 s) and execution (9 s) phase, and executed either in the presence or absence of augmented visual feedback. Performance on the bimanual tracking task, expressed as the average target error, was impaired for patients as compared to controls (P < 0.001) and for trials in the absence as compared to the presence of augmented visual feedback (P < 0.001). At the cerebral level, movement preparation was characterized by reduced neural activation in the patient group relative to the control group in frontal (bilateral superior frontal gyrus, right dorsolateral prefrontal cortex), parietal (left inferior parietal lobe) and occipital (right striate and extrastriate visual cortex) areas (P's < 0.05). During the execution phase, however, the opposite pattern emerged, i.e. traumatic brain injury patients showed enhanced activations compared with controls in frontal (left dorsolateral prefrontal cortex, left lateral anterior prefrontal cortex, and left orbitofrontal cortex), parietal (bilateral inferior parietal lobe, bilateral superior parietal lobe, right precuneus, right primary somatosensory cortex), occipital (right striate and extrastriate visual cortices), and

  13. Kingdom protozoa and its 18 phyla.

    PubMed

    Cavalier-Smith, T

    1993-12-01

    The demarcation of protist kingdoms is reviewed, a complete revised classification down to the level of subclass is provided for the kingdoms Protozoa, Archezoa, and Chromista, and the phylogenetic basis of the revised classification is outlined. Removal of Archezoa because of their ancestral absence of mitochondria, peroxisomes, and Golgi dictyosomes makes the kingdom Protozoa much more homogeneous: they all either have mitochondria and peroxisomes or have secondarily lost them. Predominantly phagotrophic, Protozoa are distinguished from the mainly photosynthetic kingdom Chromista (Chlorarachniophyta, Cryptista, Heterokonta, and Haptophyta) by the absence of epiciliary retronemes (rigid thrust-reversing tubular ciliary hairs) and by the lack of two additional membranes outside their chloroplast envelopes. The kingdom Protozoa has two subkingdoms: Adictyozoa, without Golgi dictyosomes, containing only the phylum Percolozoa (flagellates and amoeboflagellates); and Dictyozoa, made up of 17 phyla with Golgi dictyosomes. Dictyozoa are divided into two branches: (i) Parabasalia, a single phylum with hydrogenosomes and 70S ribosomes but no mitochondria, Golgi dictyosomes associated with striated roots, and a kinetid of four or five cilia; and (ii) Bikonta (16 unicellular or plasmodial phyla with mitochondria and bikinetids and in which Golgi dictyosomes are not associated with striated ciliary roots), which are divided into two infrakingdoms: Euglenozoa (flagellates with discoid mitochondrial cristae and trans-splicing of miniexons for all nuclear genes) and Neozoa (15 phyla of more advanced protozoa with tubular or flat [usually nondiscoid] mitochondrial cristae and cis-spliced spliceosomal introns). Neozoa are divided into seven parvkingdoms: (i) Ciliomyxa (three predominantly ciliated phyla with tubular mitochondrial cristae but no cortical alveoli, i.e., Opalozoa [flagellates with tubular cristae], Mycetozoa [slime molds], and Choanozoa [choanoflagellates, with

  14. Characterization of muscle contraction with second harmonic generation microscopy

    NASA Astrophysics Data System (ADS)

    Prent, Nicole

    Muscle cells have the ability to change length and generate force due to orchestrated action of myosin nanomotors that cause sliding of actin filaments along myosin filaments in the sarcomeres, the fundamental contractile units, of myocytes. The correlated action of hundreds of sarcomeres is needed to produce the myocyte contractions. This study probes the molecular structure of the myofilaments and investigates the movement correlations between sarcomeres during contraction. In this study, second harmonic generation (SHG) microscopy is employed for imaging striated myocytes. Myosin filaments in striated myocytes inherently have a nonzero second-order susceptibility, [special characters omitted] and therefore generate efficient SHG. Employing polarization-in polarization-out (PIPO) SHG microscopy allows for the accurate determination of the characteristic ratio, [special characters omitted] in birefringent myocytes, which describes the structure of the myosin filament. Analysis shows that the b value at the centre of the myosin filament, where the nonlinear dipoles are better aligned, is slightly lower than the value at the edges of the filament, where there is more disorder in orientation of the nonlinear dipoles from the myosin heads. Forced stretching of myocytes resulted in an SHG intensity increase with the elongation of the sarcomere. SHG microscopy captured individual sarcomeres during contraction, allowing for the measurement of sarcomere length (SL) and SHG intensity (SI) fluctuations. The fluctuations also revealed higher SHG intensity in elongated sarcomeres. The sarcomere synchronization model (SSM) for contracting and quiescent myocytes was developed, and experimentally verified for three cases (isolated cardiomyocyte, embryonic chicken cardiomyocyte, and larva myocyte). During contraction, the action of SLs and SIs between neighbouring sarcomeres partially correlated, whereas in quiescent myocytes the SLs show an anti-correlation and the SIs have no

  15. Preserved Flora and Organics in Impact Melt Breccias: Implications for Capturing Past Life on Mars

    NASA Astrophysics Data System (ADS)

    Schultz, P. H.; Harris, R. S.; Clemett, S.; Thomas-Keprta, K.

    2013-12-01

    At least seven impact glass-bearing deposits have been documented in the Argentine stratigraphy, each recording separate events between the Holocene and late Miocene [1,2]. Detailed evidence for their origin by impact includes: planar deformation features (PDFs in quartz, feldspars, pyroxene, olivine, etc.), asymmetric isotropization (i.e., alternate-twin deformation) in plagioclase, diaplectic phases, ultra-high temperature melting (e.g., lechatelierite, molten rutile) and decomposition (e.g., baddeleyite), and quench textures around minerals, e.g., beta-crystobalite, etc. [1-3]. Incorporation of materials from depth indicates that this was not an airburst but a series of crater-forming impacts. Many hand samples also contain relicts of extant biota. Scanning electron microprobe (SEM) images reveal preservation of delicate forms including: striated layers between vesicular impact glass and parallel vein-like features at higher magnification. The striated patterns resemble vascular bundles of the mesophyll (ground tissue) of a plant. Identifiable parts of the plant anatomy, e.g. papillae and cell walls, contain skeletal magnetite crystals and high-temperature, i.e., phases indicating that vitreous fossilization occurred at extremely high temperatures and rapid quench rates. The morphology is generally similar to contemporary regional grasses (pampas grass) including small spherules (papilla). The intricate forms (20nm to 20mm) indicate features rapidly preserved rather than simple impressions. Reaction zones (vesiculation and quenched minerals) along the interface between the melt and entrained plants indicate rapid quenching. Compositional mapping reveals the presence of insignificant levels of carbon, but chemical analyses confirm the high silica content (> 60%). Various analytical techniques (micro-Raman, TEM/SEM, and μltra-L2MS) further reveal the preserved organic materials, including tetracyclic pyrrolines, essential members of the group of porphyrin species

  16. Sphaeromyxa artedielli sp. n. (Myxozoa: Sphaeromyxidae), a parasite of sculpins (Cottidae) in northern Norway.

    PubMed

    Karlsbakk, Egil; Einen, Ann-Cathrine Bårdsgjaere; Bartosová, Pavla

    2013-11-01

    Sphaeromyxa artedielli sp. n. is described from the gall bladder of the Atlantic hookear sculpin Artediellus atlanticus Jordan et Evermann (Cottidae; type host) from northern Norway. The parasite was also found to infect Triglops murrayi Günther (Cottidae). Spores are produced in disporic pansporoblasts in large flat plasmodia. Spores are straight and fusiform with truncated ends, and measure 16.5-18.7 microm x 4.9-6.2 microm. Valves are thick, striated and suture line is straight. Two equal ovoid polar capsules measure 4.2-6.8 microm x 2.9-4.4 microm and contain irregularly folded polar filaments. Distinctive features include spore shape and size, spore length/width relationship, striated valves, equal polar capsules and a short intercapsular distance. Sphaeromyxa bonaerensis Timi et Sardella, 1998, Sphaeromyxa cannolii Sears, Anderson et Greiner, 2011, and Sphaeromyxa sevastopoli Naidenova, 1970 produce straight spores with truncated ends that are of similar length as those of the new species. Sphaeromyxa cannolii differs in showing smooth spores with unequal polar capsules. The new species differs from S. bonaerensis and S. sevastopoli in significantly wider spores and polar capsules. Sphaeromyxa balbianii Thélohan, 1892, a species originally described with significantly smaller spores than S. artedielli sp. n., has previously been recorded from T. murrayi. We show that S. artedielli sp. n. differs from S. balbianii from the type host Gaidropsarus vulgaris (Cloquet) by its SSU rDNA sequence, and suggest that Atlantic records of Sphaeromyxa spp. from T. murrayi represent S. artedielli sp. n. The closest relative to S. artedielli sp. n. according to the SSU rDNA sequences, S. longa Dunkerly, 1921, differs clearly by spore size and shape. In the SSU rDNA-based phylogenetic analyses, S. artedielli sp. n. groups with other Sphaeromyxa spp. with straight spores and truncated ends in a clade that represents a sister-group to Sphaeromyxa spp. with arcuate spores and

  17. Increased anal basal pressure in chronic anal fissures may be caused by overreaction of the anal-external sphincter continence reflex.

    PubMed

    van Meegdenburg, Maxime M; Trzpis, Monika; Heineman, Erik; Broens, Paul M A

    2016-09-01

    Chronic anal fissure is a painful disorder caused by linear ulcers in the distal anal mucosa. Even though it counts as one of the most common benign anorectal disorders, its precise etiology and pathophysiology remains unclear. Current thinking is that anal fissures are caused by anal trauma and pain, which leads to internal anal sphincter hypertonia. Increased anal basal pressure leads to diminished anodermal blood flow and local ischemia, which delays healing and leads to chronic anal fissure. The current treatment of choice for chronic anal fissure is either lateral internal sphincterotomy or botulinum toxin injections. In contrast to current thinking, we hypothesize that the external, rather than the internal, anal sphincter is responsible for increased anal basal pressure in patients suffering from chronic anal fissure. We think that damage to the anal mucosa leads to hypersensitivity of the contact receptors of the anal-external sphincter continence reflex, resulting in overreaction of the reflex. Overreaction causes spasm of the external anal sphincter. This in turn leads to increased anal basal pressure, diminished anodermal blood flow, and ischemia. Ischemia, finally, prevents the anal fissure from healing. Our hypothesis is supported by two findings. The first concerned a chronic anal fissure patient with increased anal basal pressure (170mmHg) who had undergone lateral sphincterotomy. Directly after the operation, while the submucosal anesthetic was still active, basal anal pressure decreased to 80mmHg. Seven hours after the operation, when the anesthetic had completely worn off, basal anal pressure increased again to 125mmHg, even though the internal anal sphincter could no longer be responsible for the increase. Second, in contrast to previous studies, recent studies demonstrated that botulinum toxin influences external anal sphincter activity and, because it is a striated muscle relaxant, it seems reasonable to presume that it affects the striated

  18. Myoanatomy and serotonergic nervous system of the ctenostome Hislopia malayensis: evolutionary trends in bodyplan patterning of ectoprocta

    PubMed Central

    2011-01-01

    Background Ectoprocta is a large lophotrochozoan clade of colonial suspension feeders comprising over 5.000 extant species. Their phylogenetic position within the Lophotrochzoa remains controversially discussed, but also the internal relationships of the major ectoproct subclades -Phylactolaemata, Stenolaemata, and Gymnolaemata - remains elusive. To gain more insight into the basic configuration of ectoproct muscle systems for phylogenetic considerations, we analysed the adult myoanatomy and the serotonergic nervous system as well as myogenesis in budding stages of the ctenostome Hislopia malayensis. Results In adults, the serotonergic nervous system is restricted to the lophophoral base with a high concentration in the cerebral ganglion and serotonergic perikarya between each pair of tentacles. Prominent smooth apertural muscles extend from the basal cystid wall to each lateral side of the vestibular wall. The musculature of the tentacle sheath consists of regular strands of smooth longitudinal muscles. Each tentacle is supplied with two bands of longitudinal muscles that show irregular striation. At the lophophoral base several muscles are present: (i) Short muscle fibres that proximally diverge from a single point from where they split distally into two separate strands. (ii) Proximally of the first group are smooth, longitudinal fibres that extend to the proximal-most side of the lophophoral base. (iii) Smooth muscle fibres, the buccal dilatators, traverse obliquely towards the pharynx, and (iv) a circular ring of smooth muscle fibres situated distally of the buccal dilatators. Retractor muscles are mainly smooth with short distal striated parts. The foregut consists mainly of striated ring musculature with only few longitudinal muscle fibres in the esophagus, while the remaining parts of the digestive tract solely exhibit smooth musculature. During budding, apertural and retractor muscles are first to appear, while the parietal muscles appear at a later stage

  19. Activation of Visuomotor Systems during Visually Guided Movements: A Functional MRI Study

    NASA Astrophysics Data System (ADS)

    Ellermann, Jutta M.; Siegal, Joel D.; Strupp, John P.; Ebner, Timothy J.; Ugurbil, Kâmil

    1998-04-01

    The dorsal stream is a dominant visuomotor pathway that connects the striate and extrastriate cortices to posterior parietal areas. In turn, the posterior parietal areas send projections to the frontal primary motor and premotor areas. This cortical pathway is hypothesized to be involved in the transformation of a visual input into the appropriate motor output. In this study we used functional magnetic resonance imaging (fMRI) of the entire brain to determine the patterns of activation that occurred while subjects performed a visually guided motor task. In nine human subjects, fMRI data were acquired on a 4-T whole-body MR system equipped with a head gradient coil and a birdcage RF coil using aT*2-weighted EPI sequence. Functional activation was determined for three different tasks: (1) a visuomotor task consisting of moving a cursor on a screen with a joystick in relation to various targets, (2) a hand movement task consisting of moving the joystick without visual input, and (3) a eye movement task consisting of moving the eyes alone without visual input. Blood oxygenation level-dependent (BOLD) contrast-based activation maps of each subject were generated using period cross-correlation statistics. Subsequently, each subject's brain was normalized to Talairach coordinates, and the individual maps were compared on a pixel by pixel basis. Significantly activated pixels common to at least four out of six subjects were retained to construct the final functional image. The pattern of activation during visually guided movements was consistent with the flow of information from striate and extrastriate visual areas, to the posterior parietal complex, and then to frontal motor areas. The extensive activation of this network and the reproducibility among subjects is consistent with a role for the dorsal stream in transforming visual information into motor behavior. Also extensively activated were the medial and lateral cerebellar structures, implicating the cortico

  20. A physiological analysis of subcortical and commissural projections of areas 17 and 18 of the cat.

    PubMed Central

    Harvey, A R

    1980-01-01

    1. The corticotectal, corticothalamic and commissural projections of areas 17 and 18 of the cat have been examined using electrical stimulation techniques. 2. In both area 17 and area 18, almost all corticotectal neurones are C cells and have binocular receptive fields. Some of these cells respond equally well to both small moving spots and elongated stimuli, while others only respond to stimuli of restricted length (cf. Palmer & Rosenquist, 1974). Both types are highly direction-selective. A third type of corticotectal C cell responds optimally to long edges or bars and shows only weak direction selectivity. Corticotectal cells generally have fast conducting axons and the majority are encountered in lamina V. About 25% of all cells recorded in lamina V can be antidromically activated from the superior colliculus. 3. Striate and parastriate cells efferent to the thalamus can have either S or C type receptive fields. Corticothalamic S cells are the most common type of efferent cell in lamina VI and have more slowly conducting axons than C cells. Efferent S cells are almost always direction-selective and about half have binocular receptive fields. 4. It is suggested that there may be at least three subgroups within the corticothalamic cells: lamina V C cells project to the pulvinare complex (the same cells may also send axons to the superior colliculus), lamina VI C cells project to the perigeniculate nucleus and lamina VI S cells provide the cortical input to neurones within the lateral geniculate nucleus. 5. In contrast to the corticotectal and corticothalamic projections, the receptive fields of cells projecting through the corpus callosum forth a heterogenous group. All major striate and parastriate receptive field classes are efferent to the contralateral cortex. Their receptive field centres are located close to the vertical mid line and most cells respond best to stimuli moving towards the ipsilateral visual hemifield. Efferent neurones are mostly encountered

  1. Expression profiles of inhibitor of growth protein 2 in normal and cancer tissues: An immunohistochemical screening analysis.

    PubMed

    Zhao, Shuang; Yang, Xue-Feng; Gou, Wen-Feng; Lu, Hang; Li, Hua; Zhu, Zhi-Tu; Sun, Hong-Zhi; Zheng, Hua-Chuan

    2016-02-01

    Inhibitor of growth protein 2 (ING2) has an important role in the regulation of chromatin remodeling, cell proliferation, cell‑cycle arrest, senescence and apoptosis. The present study performed an immunohistochemical analysis for expression profiling of ING2 protein in an array of tissues comprising normal mouse and human tissues, as well as human hepatocellular (n=62), renal clear cell (n=62), pancreatic (n=62), esophageal squamous cell (n=45), cervical squamous cell (n=31), breast (n=144), gastric (n=196), colorectal (n=96), ovarian (n=208), endometrial (n=96) and lung (n=192) carcinoma tissues. In mouse tissues, ING2 was detected in the nuclei and cytoplasm of the glandular epithelium of breast, hepatocytes, intestine, bronchium and alveoli, as well as the squamous epithelium of skin and glomeruli, and in myocardial cells, while it was located in the cytoplasm of renal tubules and striated muscle cells. ING2 protein was scattered in the brain and spleen. In human tissues, ING2 protein was principally distributed in the cytoplasm, while in it was present in the cytoplasm and nuclei in the stomach, intestine, cervix, endometrium trachea, breast and pancreas. The nuclear location of ING2 in the stomach was more prominent than that in the cytoplasm. High ING2 immunoreactivity was detected in the tongue, stomach, skin, pancreas, cervix and breast, whereas weakly in the brain stem, thymus, thyroid, lung, striated muscle, testis, bladder and ovary. In total, 617 out of 1,194 of the tested cancer tissues (51.7%) were ING2-positive. In most cases, ING2 expression was found to be restricted to the cytoplasm of all cancer tissues, while in certain cancer types, including renal clear cell, ovarian and colorectal carcinoma, it was occasionally present in the nuclei. Among the cancer tissues examined, ING2 was most frequently expressed in breast cancer (67.4%) and gynecological cancer types, including ovarian cancer (61.5%) and endometrial cancer (57.3%). Compared with

  2. An electron microscopic study of the intestinal villus. II. The pathway of fat absorption.

    PubMed

    PALAY, S L; KARLIN, L J

    1959-05-25

    The intestinal pathway for absorbed fat was traced in thin sections of intestinal villi from rats fed corn oil by stomach tube after a fast of 24 to 40 hours. For electron microscopy the tissues were fixed in chilled buffered osmium tetroxide and embedded in methacrylate. For light microscopy, other specimens from the same animals were fixed in formal-calcium, mordanted in K(2)Cr(2)O(7), and embedded in gelatin. Frozen sections were stained with Sudan black B or Sudan IV. About 20 minutes after feeding, small fat droplets (65 mmicro maximal diameter) appear in the striated border between microvilli. At the same time fat particles are seen within pinocytotic vesicles in the immediately subjacent terminal web. In later specimens the fat droplets are generally larger (50 to 240 mmicro) and lie deeper in the apical cytoplasm. All intracellular fat droplets are loosely enveloped in a thin membrane, the outer surface of which is sometimes studded with the fine particulate component of the cytoplasm. This envelope, apparently derived from the cell surface by pinocytosis, has at this stage evidently become a part of the endoplasmic reticulum. Just above the nucleus numerous fat droplets lie clustered within the dilated cisternae of the Golgi complex. As absorption progresses fat droplets appear in the intercellular spaces of the epithelium, in the interstitial connective tissue spaces of the lamina propria, and in the lumen of the lacteals. All of these extracellular fat droplets are devoid of a membranous envelope. The picture of fat absorption as reconstructed from these studies involves a stream of fat droplets filtering through the striated border, entering the epithelial cell by pinocytosis at the bases of the intermicrovillous spaces, and coursing through the endoplasmic reticulum to be discharged at the sides of the epithelial cell into extracellular spaces. From the epithelial spaces, the droplets move into the lamina propria and thence into the lymph. If the lumen

  3. Why Is there a Limit to the Changes in Myofilament Ca2+-Sensitivity Associated with Myopathy Causing Mutations?

    PubMed Central

    Marston, Steven B.

    2016-01-01

    Mutations in striated muscle contractile proteins have been found to be the cause of a number of inherited muscle diseases; in most cases the mechanism proposed for causing the disease is derangement of the thin filament-based Ca2+-regulatory system of the muscle. When considering the results of experiments reported over the last 15 years, one feature has been frequently noted, but rarely discussed: the magnitude of changes in myofilament Ca2+-sensitivity due to myopathy-causing mutations in skeletal or heart muscle seems to be always in the range 1.5–3x EC50. Such consistency suggests it may be related to a fundamental property of muscle regulation; in this article we will investigate whether this observation is true and consider why this should be so. A literature search found 71 independent measurements of HCM mutation-induced change of EC50 ranging from 1.15 to 3.8-fold with a mean of 1.87 ± 0.07 (sem). We also found 11 independent measurements of increased Ca2+-sensitivity due to mutations in skeletal muscle proteins ranging from 1.19 to 2.7-fold with a mean of 2.00 ± 0.16. Investigation of dilated cardiomyopathy-related mutations found 42 independent determinations with a range of EC50 wt/mutant from 0.3 to 2.3. In addition we found 14 measurements of Ca2+-sensitivity changes due skeletal muscle myopathy mutations ranging from 0.39 to 0.63. Thus, our extensive literature search, although not necessarily complete, found that, indeed, the changes in myofilament Ca2+-sensitivity due to disease-causing mutations have a bimodal distribution and that the overall changes in Ca2+-sensitivity are quite small and do not extend beyond a three-fold increase or decrease in Ca2+-sensitivity. We discuss two mechanism that are not necessarily mutually exclusive. Firstly, it could be that the limit is set by the capabilities of the excitation-contraction machinery that supplies activating Ca2+ and that striated muscle cannot work in a way compatible with life outside

  4. H5N1 surveillance in migratory birds in Java, Indonesia.

    PubMed

    Stoops, Arthur C; Barbara, Katie A; Indrawan, Mochamad; Ibrahim, Ima N; Petrus, Wicaksana B; Wijaya, Susan; Farzeli, Arik; Antonjaya, Ungke; Sin, Lim W; Hidayatullah, N; Kristanto, Ige; Tampubolon, A M; Purnama, S; Supriatna, Adam; Burgess, Timothy H; Williams, Maya; Putnam, Shannon D; Tobias, Steve; Blair, Patrick J

    2009-12-01

    We sought to elucidate the role of migratory birds in transmission of H5N1 in an enzoonotic area. Resident, captive, and migratory birds were sampled at five sites in Java, Indonesia. Mist nets were used to trap birds. Birds were identified to species. RNA was extracted from swabs and reverse transcriptase polymerase chain reaction (RT-PCR) conducted for the HA and M genes of H5N1. Antibodies were detected by enzyme-linked immunosorbent assay and hemagglutination inhibition test. Between October 2006 and September 2007, a total of 4,067 captive, resident, and migratory birds comprising 98 species in 23 genera were sampled. The most commonly collected birds were the common sandpiper (6% of total), striated heron (3%), and the domestic chicken (14%). The overall prevalence of H5N1 antibodies was 5.3%. A significantly higher percentage of captive birds (16.1%) showed antibody evidence of H5N1 exposure when compared to migratory or resident birds. The greatest number of seropositive birds in each category were Muschovy duck (captive), striated heron (resident), and the Pacific golden plover (migratory). Seven apparently well captive birds yielded molecular evidence of H5N1 infection. Following amplification, the HA, NA, and M genes were analyzed. Phylogenetic analysis of the HA gene showed that the isolates were 97% similar to EU124153.1 A/chicken/West Java/Garut May 2006, an isolate obtained in a similar region of West Java. While no known markers of neuraminidase inhibitor resistance were found within the NA gene, M segment analysis revealed the V27A mutation known to confer resistance to adamantanes. Our results demonstrate moderate serologic evidence of H5N1 infection in captive birds, sampled in five sites in Java, Indonesia, but only occasional infection in resident and migratory birds. These data imply that in an enzoonotic region of Indonesia the role of migratory birds in transmission of H5N1 is limited.

  5. Expression profiles of inhibitor of growth protein 2 in normal and cancer tissues: An immunohistochemical screening analysis.

    PubMed

    Zhao, Shuang; Yang, Xue-Feng; Gou, Wen-Feng; Lu, Hang; Li, Hua; Zhu, Zhi-Tu; Sun, Hong-Zhi; Zheng, Hua-Chuan

    2016-02-01

    Inhibitor of growth protein 2 (ING2) has an important role in the regulation of chromatin remodeling, cell proliferation, cell‑cycle arrest, senescence and apoptosis. The present study performed an immunohistochemical analysis for expression profiling of ING2 protein in an array of tissues comprising normal mouse and human tissues, as well as human hepatocellular (n=62), renal clear cell (n=62), pancreatic (n=62), esophageal squamous cell (n=45), cervical squamous cell (n=31), breast (n=144), gastric (n=196), colorectal (n=96), ovarian (n=208), endometrial (n=96) and lung (n=192) carcinoma tissues. In mouse tissues, ING2 was detected in the nuclei and cytoplasm of the glandular epithelium of breast, hepatocytes, intestine, bronchium and alveoli, as well as the squamous epithelium of skin and glomeruli, and in myocardial cells, while it was located in the cytoplasm of renal tubules and striated muscle cells. ING2 protein was scattered in the brain and spleen. In human tissues, ING2 protein was principally distributed in the cytoplasm, while in it was present in the cytoplasm and nuclei in the stomach, intestine, cervix, endometrium trachea, breast and pancreas. The nuclear location of ING2 in the stomach was more prominent than that in the cytoplasm. High ING2 immunoreactivity was detected in the tongue, stomach, skin, pancreas, cervix and breast, whereas weakly in the brain stem, thymus, thyroid, lung, striated muscle, testis, bladder and ovary. In total, 617 out of 1,194 of the tested cancer tissues (51.7%) were ING2-positive. In most cases, ING2 expression was found to be restricted to the cytoplasm of all cancer tissues, while in certain cancer types, including renal clear cell, ovarian and colorectal carcinoma, it was occasionally present in the nuclei. Among the cancer tissues examined, ING2 was most frequently expressed in breast cancer (67.4%) and gynecological cancer types, including ovarian cancer (61.5%) and endometrial cancer (57.3%). Compared with

  6. Movement preparation and execution: differential functional activation patterns after traumatic brain injury.

    PubMed

    Gooijers, Jolien; Beets, Iseult A M; Albouy, Genevieve; Beeckmans, Kurt; Michiels, Karla; Sunaert, Stefan; Swinnen, Stephan P

    2016-09-01

    Years following the insult, patients with traumatic brain injury often experience persistent motor control problems, including bimanual coordination deficits. Previous studies revealed that such deficits are related to brain structural white and grey matter abnormalities. Here, we assessed, for the first time, cerebral functional activation patterns during bimanual movement preparation and performance in patients with traumatic brain injury, using functional magnetic resonance imaging. Eighteen patients with moderate-to-severe traumatic brain injury (10 females; aged 26.3 years, standard deviation = 5.2; age range: 18.4-34.6 years) and 26 healthy young adults (15 females; aged 23.6 years, standard deviation = 3.8; age range: 19.5-33 years) performed a complex bimanual tracking task, divided into a preparation (2 s) and execution (9 s) phase, and executed either in the presence or absence of augmented visual feedback. Performance on the bimanual tracking task, expressed as the average target error, was impaired for patients as compared to controls (P < 0.001) and for trials in the absence as compared to the presence of augmented visual feedback (P < 0.001). At the cerebral level, movement preparation was characterized by reduced neural activation in the patient group relative to the control group in frontal (bilateral superior frontal gyrus, right dorsolateral prefrontal cortex), parietal (left inferior parietal lobe) and occipital (right striate and extrastriate visual cortex) areas (P's < 0.05). During the execution phase, however, the opposite pattern emerged, i.e. traumatic brain injury patients showed enhanced activations compared with controls in frontal (left dorsolateral prefrontal cortex, left lateral anterior prefrontal cortex, and left orbitofrontal cortex), parietal (bilateral inferior parietal lobe, bilateral superior parietal lobe, right precuneus, right primary somatosensory cortex), occipital (right striate and extrastriate visual cortices), and

  7. Kingdom protozoa and its 18 phyla.

    PubMed Central

    Cavalier-Smith, T

    1993-01-01

    The demarcation of protist kingdoms is reviewed, a complete revised classification down to the level of subclass is provided for the kingdoms Protozoa, Archezoa, and Chromista, and the phylogenetic basis of the revised classification is outlined. Removal of Archezoa because of their ancestral absence of mitochondria, peroxisomes, and Golgi dictyosomes makes the kingdom Protozoa much more homogeneous: they all either have mitochondria and peroxisomes or have secondarily lost them. Predominantly phagotrophic, Protozoa are distinguished from the mainly photosynthetic kingdom Chromista (Chlorarachniophyta, Cryptista, Heterokonta, and Haptophyta) by the absence of epiciliary retronemes (rigid thrust-reversing tubular ciliary hairs) and by the lack of two additional membranes outside their chloroplast envelopes. The kingdom Protozoa has two subkingdoms: Adictyozoa, without Golgi dictyosomes, containing only the phylum Percolozoa (flagellates and amoeboflagellates); and Dictyozoa, made up of 17 phyla with Golgi dictyosomes. Dictyozoa are divided into two branches: (i) Parabasalia, a single phylum with hydrogenosomes and 70S ribosomes but no mitochondria, Golgi dictyosomes associated with striated roots, and a kinetid of four or five cilia; and (ii) Bikonta (16 unicellular or plasmodial phyla with mitochondria and bikinetids and in which Golgi dictyosomes are not associated with striated ciliary roots), which are divided into two infrakingdoms: Euglenozoa (flagellates with discoid mitochondrial cristae and trans-splicing of miniexons for all nuclear genes) and Neozoa (15 phyla of more advanced protozoa with tubular or flat [usually nondiscoid] mitochondrial cristae and cis-spliced spliceosomal introns). Neozoa are divided into seven parvkingdoms: (i) Ciliomyxa (three predominantly ciliated phyla with tubular mitochondrial cristae but no cortical alveoli, i.e., Opalozoa [flagellates with tubular cristae], Mycetozoa [slime molds], and Choanozoa [choanoflagellates, with

  8. Obscurin: a multitasking muscle giant.

    PubMed

    Kontrogianni-Konstantopoulos, Aikaterini; Bloch, Robert J

    2005-01-01

    Obscurin (approximately 800 kDa) is the third member of a family of giant proteins expressed in vertebrate striated muscle, along with titin (3-3.7 MDa) and nebulin (approximately 800 kDa). Like its predecessors, it is a multidomain protein composed of tandem adhesion modules and signaling domains. Unlike titin and nebulin, which are integral components of sarcomeres, obscurin is concentrated at the peripheries of Z-disks and M-lines, where it is appropriately positioned to communicate with the surrounding myoplasm. This unique distribution allows obscurin to bind small ankyrin 1, an integral component of the sarcoplasmic reticulum (SR) membrane. Obscurin also associates with the contractile apparatus through its binding to titin, sarcomeric myosin and perhaps other proteins of the contractile apparatus. Overexpression of the COOH-terminus of obscurin in primary myotubes has a dramatic and specific effect on the organization of sarcomeric myosin, indicating a role in the organization and regular assembly of A-bands. Given its ability to associate tightly, selectively and periodically with the periphery of the myofibril, its high affinity for an integral membrane protein of the SR and its close association with thick filaments, we speculate that obscurin is ideally suited to play key roles in modulating the organization and assembly of both the myofibril and the SR.

  9. Cold exposure induces alterations in porcine triiodothyronine tissue distribution

    SciTech Connect

    Quesada, M.H.; Reed, H.L.; Hesslink, R.; Licauco, G.; Castro, S.; Homer, L.; Young, B. Univ. of Alberta, Edmonton )

    1991-03-11

    Evidence suggests that thyroid hormone plays an active role in modulation of tissue metabolism in response to cold challenge. In an attempts to identify tissues that may have increased capacity for triiodothyronine (T{sub 3}) and be actively involved in the thermogenic process, the authors investigated the T{sub 3} tissue distribution in 5 month old swine exposed to cold (4C) (N = 5) for three weeks, compared with controls at a thermoneutral temperature (20C) (N = 4). Both groups were injected I.V. with ({sup 125}I)T{sub 3} three hours before sacrifice. ({sup 125}I)T{sub 3} was organically extracted from heart, kidney, thyroid gland, adrenal, brain, 4 different types of striated muscles and fat tissues and counted to determine the CPM/gm of tissue. Serum total T{sub 3} and free T{sub 3} were elevated. The bulk of the tissue/serum ratios of cold exposed swine compared with controls were unchanged. However, calculation of the T{sub 3} organ pools revealed that the majority was elevated 2 to 3 times over control. Increases in tissue distribution volume (TVD) occurred in hip fat. Body and organ weights tended to increase but not to a significant degree except for the thyroid gland, which increased 66% over the average control value. The physiological significance of the cold associated augmented organ pool and the increased TCD in hip fat needs to be explored.

  10. Digestion of starch granules from maize, potato and wheat by larvae of the the yellow mealworm, Tenebrio molitor and the Mexican bean weevil, Zabrotes subfasciatus.

    PubMed

    Meireles, Elaine A; Carneiro, Cíntia N B; DaMatta, Renato A; Samuels, Richard I; Silva, Carlos P

    2009-01-01

    Scanning electron microscopy images were taken of starch granules from different sources following exposure in vivo and in vitro to gut alpha-amylases isolated from Tenebrio molitor L. (Coleoptera: Tenebrionidae) and Zabrotes subfasciatus Boheman (Coleoptera: Bruchidae). One alpha-amylase was isolated from whole larval midguts of T. molitor using non-denaturing SDS-PAGE, while two other alpha-amylase fractions were isolated from whole larval midguts of Z. subfasciatus using hydrophobic interaction chromatography., Digested starch granules from larvae fed on maize, potato or wheat were isolated from midgut contents. Combinations of starch granules with isolated alpha-amylases from both species showed similar patterns of granule degradation. In vitro enzymatic degradation of maize starch granules by the three different alpha-amylase fractions began by creating small holes and crater-like areas on the surface of the granules. Over time, these holes increased in number and area resulting in extensive degradation of the granule structure. Granules from potato did not show formation of pits and craters on their surface, but presented extensive erosion in their interior. For all types of starch, as soon as the interior of the starch granule was reached, the inner layers of amylose and amylopectin were differentially hydrolyzed, resulting in a striated pattern. These data support the hypothesis that the pattern of starch degradation depends more on the granule type than on the alpha-amylase involved. PMID:19619014

  11. Locking regulatory myosin in the off-state with trifluoperazine.

    PubMed

    Patel, H; Margossian, S S; Chantler, P D

    2000-02-18

    Scallop striated adductor muscle myosin is a regulatory myosin, its activity being controlled directly through calcium binding. Here, we show that millimolar concentrations of trifluoperazine were effective at removal of all regulatory light chains from scallop myosin or myofibrils. More important, 200 microM trifluoperazine, a concentration 10-fold less than that required for light-chain removal, resulted in the reversible elimination of actin-activated and intrinsic ATPase activities. Unlike desensitization induced by metal ion chelation, which leads to an elevation of activity in the absence of calcium concurrent with regulatory light-chain removal, trifluoperazine caused a decline in actin-activated MgATPase activity both in the presence and absence of calcium. Procedures were equally effective with respect to scallop myosin, myofibrils, subfragment-1, or desensitized myofibrils. Increased alpha-helicity could be induced in the isolated essential light chain through addition of 100-200 microM trifluoperazine. We propose that micromolar concentrations of trifluoperazine disrupt regulation by binding to a single high-affinity site located in the C-terminal domain of the essential light chain, which locks scallop myosin in a conformation resembling the off-state. At millimolar trifluoperazine concentrations, additional binding sites on both light chains would be filled, leading to regulatory light-chain displacement.

  12. The myofilament elasticity and its effect on kinetics of force generation by the myosin motor.

    PubMed

    Piazzesi, Gabriella; Dolfi, Mario; Brunello, Elisabetta; Fusi, Luca; Reconditi, Massimo; Bianco, Pasquale; Linari, Marco; Lombardi, Vincenzo

    2014-06-15

    The half-sarcomere is the functional unit of striated muscle, in which, according to a "linear" mechanical model, myosin motors are parallel force generators with an average strain s acting between the opposing myosin and actin filaments that behave as a series elastic element with compliance Cf. Thus the definition of the mechanism of force generation by myosin motors in muscle requires integration of the crystallographic model of the working stroke with the mechanical constraints provided by the organization of motors in the half-sarcomere. The relation between half-sarcomere compliance and force (Chs-T) during the development of isometric contraction deviates, at low forces, from that predicted by the linear model, indicating the presence of an elastic element in parallel with the myosin motors, which may influence the estimate of s. A working stroke model, kinetically constrained by the early phase of the isotonic velocity transient following a force step, predicts that the rate of quick force recovery following a length step is reduced to the observed value by a Cf of 12.6nm/MPa. With this value of Cf, the fit of Chs-T relation during the isometric force rise gives s=1.8-1.9nm, similar to the values estimated using the linear model. PMID:24631572

  13. Assembling the myofibril: coordinating contractile cable construction with calcium.

    PubMed

    Ferrari, Michael B; Podugu, Sireesha; Eskew, Jeffery D

    2006-01-01

    Over the last half century, major theoretical and experimental advances have been made in understanding the molecular architecture (e.g., sarcomeric organization) and biophysics (e.g., excitation-contraction coupling) of striated muscle. Studies of how the contractile apparatus is assembled have a shorter history, but our understanding has deepened considerably over the last decade. This review focuses on spontaneous intracellular calcium (Ca2+) signals and their role in skeletal muscle myofibrillogenesis. In embryonic skeletal muscle, several classes of spontaneous Ca2+ signal occur both in vivo and in culture, and blocking their production prevents de novo sarcomere assembly. This review includes a brief overview of myofibrillogenesis, discussion of spontaneous Ca2+ signals produced in embryonic skeletal muscle, the Xenopus model system, the role of Ca2+ signals in regulating assembly of the three major filament systems (actin, titin, and myosin), integration of physiological and biochemical approaches to the problem, and the clinical relevance of basic research in this area. Interspersed throughout are suggestions for future directions and citations for reviews in closely related areas not covered herein.

  14. Sequential activation of alpha-actin genes during avian cardiogenesis: vascular smooth muscle alpha-actin gene transcripts mark the onset of cardiomyocyte differentiation

    PubMed Central

    1988-01-01

    The expression of cytoplasmic beta-actin and cardiac, skeletal, and smooth muscle alpha-actins during early avian cardiogenesis was analyzed by in situ hybridization with mRNA-specific single-stranded DNA probes. The cytoplasmic beta-actin gene was ubiquitously expressed in the early chicken embryo. In contrast, the alpha-actin genes were sequentially activated in avian cardiac tissue during the early stages of heart tube formation. The accumulation of large quantities of smooth muscle alpha-actin transcripts in epimyocardial cells preceded the expression of the sarcomeric alpha-actin genes. The accumulation of skeletal alpha-actin mRNAs in the developing heart lagged behind that of cardiac alpha-actin by several embryonic stages. At Hamburger- Hamilton stage 12, the smooth muscle alpha-actin gene was selectively down-regulated in the heart such that only the conus, which subsequently participates in the formation of the vascular trunks, continued to express this gene. This modulation in smooth muscle alpha- actin gene expression correlated with the beginning of coexpression of sarcomeric alpha-actin transcripts in the epimyocardium and the onset of circulation in the embryo. The specific expression of the vascular smooth muscle alpha-actin gene marks the onset of differentiation of cardiac cells and represents the first demonstration of coexpression of both smooth muscle and striated alpha-actin genes within myogenic cells. PMID:3204121

  15. Comparative morphology of leaf epidermis in eight populations of Atlas Pistachio (Pistacia atlantica Desf., Anacardiaceae).

    PubMed

    Belhadj, Safia; Derridj, Arezki; Aigouy, Thierry; Gers, Charles; Gauquelin, Thierry; Mevy, Jean-Philippe

    2007-10-01

    A comparative analysis was undertaken to conduct a micromorphological study of Pistacia atlantica leaves by comparing different populations grown under different climatic conditions. Leaf epidermis of eight wild populations was investigated under scanning electron microscope. Micromorphological characteristics (epidermis ornament, stomata type, waxes as well as trichomes) of the adaxial and abaxial leaf surfaces were examined. The epidermis ornament varied among populations and leaf surface, the abaxial leaf surface is reticulate with a striate surface. Messaad site shows a smooth uneven surface. The adaxial leaf surface is smooth but several ornamentations can be seen. The leaflet is amphistomatic; the stomata appeared to be slightly sunken. A variety of stomatal types were recorded; actinocytic and anomocytic types are the most frequent. The indumentum consisted of glandular and nonglandular trichomes. Unicellular glandular trichomes are recorded for P. atlantica leaves in this study. Their density is higher in Oued safene site, located at the highest altitude in comparison with the other populations. The wax occurred in all the sites and its pattern varied according to the populations studied, particularly between Berriane and Messaad. The morphological variability exhibited by the eight populations of P. atlantica may be interpreted as relevant to the ecological plasticity and the physiological mechanisms involved are discussed in this report.

  16. Intradermal Gene Immunization: The Possible Role of DNA Uptake in the Induction of Cellular Immunity to Viruses

    NASA Astrophysics Data System (ADS)

    Raz, Eyal; Carson, Dennis A.; Parker, Suezanne E.; Parr, Tyler B.; Abai, Anna M.; Aichinger, Gerald; Gromkowski, Stanislaw H.; Singh, Malini; Lew, Denise; Yankauckas, Michelle A.; Baird, Stephen M.; Rhodes, Gary H.

    1994-09-01

    The skin and mucous membranes are the anatomical sites where most viruses are first encountered by the immune system. Previous experiments have suggested that striated muscle cells are unique among mammalian cell types in their capacity to take up and express free DNA in the absence of a viral vector or physical carrier. However, we have found that mice injected into the superficial skin with free (naked) plasmid DNA encoding the influenza nucleoprotein gene had discrete foci of epidermal and dermal cells, including cells with dendritic morphology, that contained immunoreactive nucleoprotein antigen. A single intradermal administration of 0.3-15 μ g of free plasmid DNA induced anti-nucleoprotein-specific antibody and cytotoxic T lymphocytes that persisted for at least 68-70 weeks after vaccination. Intradermal gene administration induced higher antibody titers than did direct gene injection into skeletal muscle and did not cause local inflammation or necrosis. Compared with control animals, the gene-injected mice were resistant to challenge with a heterologous strain of influenza virus. These results indicate that the cells of the skin can take up and express free foreign DNA and induce cellular and humoral immune responses against the encoded protein. We suggest that DNA uptake by the skin-associated lymphoid tissues may play a role in the induction of cytotoxic T cells against viruses and other intracellular pathogens.

  17. Functional organization of the fusiform gyrus revealed with connectivity profiles.

    PubMed

    Zhang, Wen; Wang, Jiaojian; Fan, Lingzhong; Zhang, Yuanchao; Fox, Peter T; Eickhoff, Simon B; Yu, Chunshui; Jiang, Tianzi

    2016-08-01

    Within the object recognition-related ventral visual stream, the human fusiform gyrus (FG), which topographically connects the striate cortex to the inferior temporal lobe, plays a pivotal role in high-level visual/cognitive functions. However, though there are many previous investigations of distinct functional modules within the FG, the functional organization of the whole FG in its full functional heterogeneity has not yet been established. In the current study, a replicable functional organization of the FG based on distinct anatomical connectivity patterns was identified. The FG was parcellated into medial (FGm), lateral (FGl), and anterior (FGa) regions using diffusion tensor imaging. We validated the reasonability of such an organizational scheme from the perspective of resting-state whole brain functional connectivity patterns and the involvement of functional subnetworks. We found corroborating support for these three distinct modules, and suggest that the FGm serves as a transition region that combines multiple stimuli, the FGl is responsible for categorical recognition, and the FGa is involved in semantic understanding. These findings support two organizational functional transitions of the ventral temporal gyrus, a posterior/anterior direction of visual/semantic processing, and a media/lateral direction of high-level visual processing. Our results may facilitate a more detailed study of the human FG in the future. Hum Brain Mapp 37:3003-3016, 2016. © 2016 Wiley Periodicals, Inc.

  18. Segmental and descending control of the external urethral and anal sphincters in the cat.

    PubMed Central

    Mackel, R

    1979-01-01

    1. The present work concerns the contribution of the somatic central nervous system to two viscero-somatic reflexes, micturition and defecation. Descending and segmental actions and properties of the motoneurones innervating the striated external urethral and external anal sphincters were studied with intracellular recording in male cats, under chloralose anaesthesia. 2. Motoneurones innervating the external urethral and external anal sphincters were intermingled and most strongly concentrated in the lateral part of the ventral horn in the S2 segment of the spinal cord. 3. Stimulation of the S1 to S3 ipsilateral dorsal roots or of the homonymous pudendal nerve branches showed that less than half of the sphincter motoneurons receive monosynaptic excitatory connexions from low threshold afferents. 4. The after-hyperpolarization recorded in the external urethral and external anal sphincter motoneurones was relatively short lasting, not long lasting as would have been expected for motoneurones innervating slow-twitch, tonic type muscles. 5. There was no evidence for recurrent inhibition in pudendal motoneurones innervating the external urethral and external anal sphincters. 6. Descending excitation and inhibition to the sphincter motoneurones originated in the nucleus reticularis gigantocellularis of the medullary reticular formation. The descending reticulospinal actions are comparable to those observed in hind limb motoneurones. 7. It is suggested that the segmental reflex connexions play a role in controlling bladder and rectal continence. The descending actions studied also modulate the segmental reflex actions and may provide voluntary control of the sphincter muscles. PMID:512936

  19. Myosin filament 3D structure in mammalian cardiac muscle☆

    PubMed Central

    AL-Khayat, Hind A.; Morris, Edward P.; Kensler, Robert W.; Squire, John M.

    2008-01-01

    A number of cardiac myopathies (e.g. familial hypertrophic cardiomyopathy and dilated cardiomyopathy) are linked to mutations in cardiac muscle myosin filament proteins, including myosin and myosin binding protein C (MyBP-C). To understand the myopathies it is necessary to know the normal 3D structure of these filaments. We have carried out 3D single particle analysis of electron micrograph images of negatively stained isolated myosin filaments from rabbit cardiac muscle. Single filament images were aligned and divided into segments about 2 × 430 Å long, each of which was treated as an independent ‘particle’. The resulting 40 Å resolution 3D reconstruction showed both axial and azimuthal (no radial) myosin head perturbations within the 430 Å repeat, with successive crown rotations of approximately 60°, 60° and 0°, rather than the regular 40° for an unperturbed helix. However, it is shown that the projecting density peaks appear to start at low radius from origins closer to those expected for an unperturbed helical filament, and that the azimuthal perturbation especially increases with radius. The head arrangements in rabbit cardiac myosin filaments are very similar to those in fish skeletal muscle myosin filaments, suggesting a possible general structural theme for myosin filaments in all vertebrate striated muscles (skeletal and cardiac). PMID:18472277

  20. Comparison of biaxial mechanical properties of coronary sinus tissues from porcine, ovine and aged human species.

    PubMed

    Pham, Thuy; Sun, Wei

    2012-02-01

    Due to its proximity to the mitral valve, the coronary sinus (CS) vessel serves as a conduit for the deployment and implantation of the percutaneous transvenous mitral annuloplasty (PTMA) devices that can potentially reduce the mitral regurgitation. Because CS vessel is a venous tissue and seldom diseased, its mechanical properties have not been well studied. In this study, we performed a multi-axial mechanical test and histological analysis to characterize the mechanical and structural properties of the aged human, porcine and ovine CS tissues. The results showed that the aged human CS tissues exhibited much stiffer and highly anisotropic behaviors compared to the porcine and ovine. Both of the porcine and ovine CS vessel walls were thicker and mainly composed of striated muscle fibers (SMF), whereas the thinner aged human CS had higher collagen, less SMF, and more fragmented elastin fibers, which are possibly due to aging effects. We also observed that the anatomical features of porcine CS vessel might be not suitable for PTMA deployment. These differences between animal and human models raise questions for the validity of using animal models to investigate the biomechanics involved in the PTMA intervention. Therefore, caution must be taken in future studies of PTMA stents using animal models.

  1. Fine structure of body wall cuticle of females of eight genera of heteroderidae.

    PubMed

    Cliff, G M; Baldwin, J G

    1985-07-01

    Body wall cuticle of adult females of eight genera within the Heteroderidae was examined by transmission electron microscopy for comparison with previously studied species within the family. Cuticle structure was used to test some current hypotheses of phylogeny of Heteroderidae and to evaluate intrageneric variability in cuticle layering. Verutus, Rhizonema, and Meloidodera possess striated cuticle surfaces and have the simplest layering, suggesting that striations have not necessarily arisen repeatedly in Heteroderidae through convergent or parallel evolution. Atalodera and Thecavermiculatus possess similar cuticles with derived characteristics, strengthening the hypothesis that the two genera are sister groups. Similarly, the cuticle of Cactodera resembles the specialized cuticle of Globodera and Punctodera in having a basal layer (D) and a surface layer infused with electron-dense substance. Heterodera betulae has a unique cuticle in which the thickest layer (C) is infiltrated with an electron-dense matrix. Little intrageneric difference was found between cuticles of two species of Meloidodera or between two species of Atalodera. However, Atalodera ucri has a basal layer (E) not found in other Heteroderidae. The most striking intrageneric variation in cuticle structure was observed between the thin three-layered cuticle of Sarisodera africana and the much thicker four-layered cuticle of Sarisodera hydrophila; results do not support monophyly of Sarisodera.

  2. Prediction of in vivo background in phoswich lung count spectra

    SciTech Connect

    Richards, N.W. . Office of Radiation Protection)

    1999-05-01

    Phoswich scintillation counters are used to detect actinides deposited in the lungs. The resulting spectra, however, contain Compton background from the decay of [sup 40]K, which occurs naturally in the striated muscle tissue of the body. To determine the counts due to actinides in a lung count spectrum, the counts due to [sup 40]K scatter must first be subtracted out. The [sup 40]K background in the phoswich NaI(Tl) spectrum was predicted from an energy region of interest called the monitor region, which is above the [sup 238]Pu region and the [sup 241]Am region, where photopeaks from [sup 238]Pu and [sup 241]Am region, where photopeaks from [sup 238]Pu and [sup 241]Am occur. Empirical models were developed to predict the backgrounds in the [sup 238]Pu and [sup 241]Am regions by testing multiple linear and nonlinear regression models. The initial multiple regression models contain a monitor region variable as well as the variables gender, (weight/height)[sup [alpha

  3. Molecular analysis of the muscle protein projectin in Lepidoptera.

    PubMed

    Ayme-Southgate, A J; Turner, L; Southgate, R J

    2013-01-01

    Striated muscles of both vertebrates and insects contain a third filament composed of the giant proteins, namely kettin and projectin (insects) and titin (vertebrates). All three proteins have been shown to contain several domains implicated in conferring elasticity, in particular a PEVK segment. In this study, the characterization of the projectin protein in the silkmoth, Bombyx mori L. (Lepidoptera: Bombycidae), and the monarch butterfly, Danaus plexippus L. (Lepidoptera: Nymphalidae), as well as a partial characterization in the Carolina sphinx, Manduca sexta L. (Lepidoptera: Sphingidae), are presented. This study showed that, similar to other insects, projectin's overall modular organization was conserved, but in contrast, the PEVK region had a highly divergent sequence. The analysis of alternative splicing in the PEVK region revealed a small number of possible isoforms and the lack of a flight-muscle specific variant, both characteristics being in sharp contrast with findings from other insects. The possible correlation with difference in flight muscle stiffness and physiology between Lepidoptera and other insect orders is discussed.

  4. Phasmid ultrastructure of an ascaridoid nematode Hysterothylacium auctum.

    PubMed

    Fagerholm, Hans-Peter; Brunanská, Magdaléna; Roepstorff, Allan; Eriksen, Lis

    2004-06-01

    Here, for the first time in an ascaridoid (Hysterothylacium auctum), we present structural features of the phasmids, paired sense organs, positioned in a bilateral manner close to the point of the tail; the features were obtained using scanning and transmission electron microscopy. We found that each phasmid consists of a single ciliated dendritic process situated in a phasmidial canal surrounded by 2 supporting cells, a socket and a sheath cell. The socket cell contains clusters of electron-dense fibrous material in its apical region and covers the phasmidial canal along its whole length. The sheath cell is characterized by a well-developed endoplasmic reticulum. The phasmidial canal is lined with a thin layer of cuticle that becomes incomplete at the base of the ciliated dendritic process. In this region, the dendritic process consists primarily of a high number of microtubule singlets and some peripheral microtubule doublets. The base of the dendritic process, containing numerous striated rootlets, gives off a large number of fingerlike offshoots, villi, invading the surrounding sheath cell. The systematic significance and functional implication of the phasmid in nematodes are also discussed. PMID:15270092

  5. Serum creatinine concentration at the onset of uremia: higher levels in black males.

    PubMed

    Abuelo, J G; Shemin, D; Chazan, J A

    1992-06-01

    We compared serum creatinine and blood urea nitrogen concentrations, estimated creatinine clearances and frequency of uremic symptoms at the start of chronic hemodialysis in all 20 black and 179 white males treated between 1969 and 1983. Serum creatinine concentrations were significantly higher in black males (16.5 +/- 5.9 mg/dl) than in white males (11.7 +/- 4.7 mg/dl; p = 0.016). There were no significant differences in blood urea nitrogen concentration, estimated creatinine clearance and frequency of uremic symptoms between the two groups. Blood urea nitrogen to serum creatinine ratios were lower in black males, (7.3 +/- 1.9) than in white males (11.4 +/- 3.8; p = 0.0001), and only one black male had a ratio greater than 10 compared to 60% of whites. We concluded that black males tend to have higher serum creatinine concentrations than white males at the onset of uremic symptoms, and that higher striated muscle creatinine production in black males and not lower renal function may be the cause.

  6. Ulysses radio and plasma wave observations in the Jupiter environment

    NASA Technical Reports Server (NTRS)

    Stone, R. G.; Pedersen, B. M.; Harvey, C. C.; Canu, P.; Cornilleau-Wehrlin, N.; Desch, M. D.; De Villedary, C.; Fainberg, J.; Farrell, W. M.; Goetz, K.

    1992-01-01

    The Unified Radio and Plasma Wave (URAP) experiment has produced new observations of the Jupiter environment, owing to the unique capabilities of the instrument and the traversal of high Jovian latitudes. Broad-band continuum radio emission from Jupiter and in situ plasma waves have proved valuable in delineating the magnetospheric boundaries. Simultaneous measurements of electric and magnetic wave fields have yielded new evidence of whistler-mode radiation within the magnetosphere. Observations of auroral-like hiss provided evidence of a Jovian cusp. The source direction and polarization capabilities of URAP have demonstrated that the outer region of the Io plasma torus supported at least five separate radio sources that reoccurred during successive rotations with a measurable corotation lag. Thermal noise measurements of the Io torus densities yielded values in the densest portion that are similar to models suggested on the basis of Voyager observations of 13 years ago. The URAP measurements also suggest complex beaming and polarization characteristics of Jovian radio components. In addition, a new class of kilometer-wavelength striated Jovian bursts has been observed.

  7. The evolution of a disparity decision in human visual cortex

    PubMed Central

    Cottereau, Benoit R.; Ales, Justin M.; Norcia, Anthony M.

    2015-01-01

    We used fMRI-informed EEG source-imaging in humans to characterize the dynamics of cortical responses during a disparity-discrimination task. After the onset of a disparity-defined target, decision-related activity was found within an extended cortical network that included several occipital regions of interest (ROIs): V4, V3A, hMT+ and the Lateral Occipital Complex (LOC). By using a response-locked analysis, we were able to determine the timing relationships in this network of ROIs relative to the subject's behavioral response. Choice-related activity appeared first in the V4 ROI almost 200 ms before the button press and then subsequently in the V3A ROI. Modeling of the responses in the V4 ROI suggests that this area provides an early contribution to disparity discrimination. Choice-related responses were also found after the button-press in ROIs V4, V3A, LOC and hMT+. Outside the visual cortex, choice-related activity was found in the frontal and temporal pole before the button-press. By combining the spatial resolution of fMRI-informed EEG source imaging with the ability to sort out neural activity occurring before, during and after the behavioral manifestation of the decision, our study is the first to assign distinct functional roles to the extra-striate ROIs involved in perceptual decisions based on disparity, the primary cue for depth. PMID:24513152

  8. PHF6 Deletions May Cause Borjeson-Forssman-Lehmann Syndrome in Females.

    PubMed

    Berland, S; Alme, K; Brendehaug, A; Houge, G; Hovland, R

    2011-09-01

    In a 16-year-old girl with intellectual disability, irregular teeth, slight body asymmetry, and striated skin pigmentation, highly skewed X-inactivation increased the likelihood of an X-linked cause of her condition. Among these, prominent supraorbital ridges and hearing loss suggested a filaminopathy, but no filamin A mutation was found. The correct diagnosis, Borjeson-Forssman-Lehmann syndrome (BFLS, MIM#301900), was first made when a copy number array identified a de novo 15-kb deletion of the terminal 3 exons of the PHF6 gene. In retrospect, her phenotype resembled that of males with BFLS. Such deletions of PHF6 have not been reported previously. This might be because PHF6 mutations are rarely looked for in females since classical BFLS so far has been thought to be a male-specific syndrome, and large PHF6 deletions might be incompatible with male fetal survival. If this is the case, sporadic BFLS could be more frequent in females than in males.

  9. Three cases of primary small vessel vasculitis of the skeletal muscle–an own entity

    PubMed Central

    Benz, Nadja; Daikeler, Thomas; Frank, Stephan; Mehling, Matthias; Tyndall, Alan; Trendelenburg, Marten

    2011-01-01

    Whereas systemic vasculitis is the most common form of vasculitis, vasculitis restricted to a single organ system is rare. Primary vasculitis restricted to striated skeletal muscle has been described in few case reports for polyarteritis nodosa and leucocytoclastic vasculitis, but not for small vessel vasculitis, type microscopic polyangiitis. The authors describe three patients with primary small vessel vasculitis of the skeletal muscle without evidence of other major organ involvement. All three patients presented with myalgias and highly elevated acute phase reactants while muscle weakness and elevated creatine kinase levels were not consistently present. Diagnoses were established by muscle biopsy and extensive search for potential causes of secondary vasculitis. Complete remission could be accomplished by steroids alone in only one case, while additional immunosuppressants were needed in the other two cases. Primary small vessel vasculitis of the skeletal muscle should be considered in patients presenting with myalgia and signs of systemic inflammation in the absence of other organ manifestations. Once diagnosed, aggressive systemic immunosuppression is appropriate. PMID:22674106

  10. Reconstruction of the muscle system in Antygomonas sp. (Kinorhyncha, Cyclorhagida) by means of phalloidin labeling and cLSM.

    PubMed

    Müller, Monika C M; Schmidt-Rhaesa, Andreas

    2003-05-01

    In the present investigation the entire muscle system of the cyclorhagid kinorhynch Antygomonas sp. was three-dimensionally reconstructed from whole mounts by means of FITC-phalloidin labeling and confocal scanning microscopy. With this technique, which proved to be especially useful for microscopically small species, we wanted to reinvestigate and supplement the findings obtained by histological and electron microscopical methods. The organization of the major muscle systems can be summarized as follows: 1) All muscle fibers, apart from the intestinal ones, the spine, and the mouth cone muscles, show a cross-striated pattern; 2) Dorsal longitudinal muscle fibers as well as segmentally arranged dorsoventral fibers occur from segment III to XIII; 3) Diagonal muscle fibers are located laterally in segments III to X; 4) Two rings of circular fibers are present in segment II, forming the closing apparatus in Cyclorhagida. Further circular muscles are present in segment I, forming the mouth cone and the eversible introvert, and in the pharyngeal bulb. PMID:12635104

  11. Hypo-activity screening in school setting; examining reliability and validity of the Teacher Estimation of Activity Form (TEAF).

    PubMed

    Rosenblum, Sara; Engel-Yeger, Batya

    2015-06-01

    It is well established that physical activity during childhood contributes to children's physical and psychological health. The aim of this study was to test the reliability and validity of the Hebrew version of the Teacher Estimation of Activity Form (TEAF) questionnaire as a screening tool among school-aged children in Israel. Six physical education teachers completed TEAF questionnaires of 123 children aged 5-12 years, 68 children (55%) with Typical Development (TD) and 55 children (45%) diagnosed with Developmental Coordination Disorder (DCD). The Hebrew version of the TEAF indicates a very high level of internal consistency (α = .97). There were no significant gender differences. Significant differences were found between children with and without DCD attesting to the test's construct validity. Concurrent validity was established by finding a significant high correlation (r = .76, p < .01) between the TEAF and the Movement-ABC mean scores within the DCD group. The TEAF demonstrated acceptable reliability and validity estimates. It appears to be a promising standardized practical tool in both research and practice for describing information about school-aged children's involvement in physical activity. Further research is indicated with larger samples to establish cut-off scores determining what point identifies hypo activity in striated age groups. Furthermore, the majority of the participants in this study were boys, and further research is needed to include more girls for a better understanding of the phenomena of hypo activity.

  12. Gross and microscopic observations on the lingual structure of the Florida Manatee Trichechus manatus latirostris.

    PubMed

    Levin, M J; Pfeiffer, C J

    2002-10-01

    The tongue of the Florida manatee (Trichechus manatus latirostris) was studied macroscopically, light and electron microscopically. The tongue was slender, muscular and firmly fixed in the oral cavity; only the cranial tip was free and mobile. Numerous filiform papillae were distributed over the dorsal surface of the rostral tongue. Multiple raised, round fungiform-like papillae were distributed over most of the dorsum. Typical fungiform papillae were restricted to the lateral margins of the tongue. Foliate papillae, presenting as multi-fossulate openings, were noted on the caudolateral margins. Open pits were located on the dorsocaudal surface and lateral walls. Microscopic examination showed that most of the lingual dorsum was covered with a thick stratified squamous epithelium. Open pits led to well-developed mucous salivary glands. Glands within the foliate papillae were mostly mucous, although some seromucous glands were present. Taste buds were restricted to the epithelium of the foliate papillae. Throughout the tongue, striated muscle was abundant below the epithelium. Blood vessels, lymph channels and nerve fibres were freely distributed throughout the intermuscular stroma. Nerve fibres reacted positively with neurone specific enolase (NSE) antibody throughout the tongue, including nerve bundles, glands and taste buds. Clear to translucent vacuoles were found juxtaposed to nuclei in the stratum spinosum in the foliate papillae epithelium.

  13. The potential of milk thistle (Silybum marianum L.), an Israeli native, as a source of edible sprouts rich in antioxidants.

    PubMed

    Vaknin, Yiftach; Hadas, Rivka; Schafferman, Dan; Murkhovsky, Leonid; Bashan, Neta

    2008-06-01

    The potential of wild plants in Israel as sources of edible sprouts has not been investigated until now. Milk thistle (Silybum marianum L.) is native to the Mediterranean basin and is now widespread throughout the world; its young fleshy stems are traditionally eaten by the local Arab sector in Israel, and its sprouts are rich in antioxidants and have been used as a traditional medicine for diseases of the liver and biliary tract. The active extract of milk thistle, silymarin, is a mixture of flavonolignans and is a strong antioxidant that has been proved to promote liver cell regeneration, to reduce blood cholesterol and to help prevent cancer. The present objective was to investigate the potential of milk thistle as a source of edible sprouts rich in antioxidants. We found that seed germination within 3-4 days was high (96%, except for striated seeds). Exposure to light significantly reduced sprout growth and significantly increased the polyphenol content and antioxidative capacity. The polyphenol content was 30% higher in seeds originating from purple inflorescences than in those from white ones. We thus found milk thistle to be a good candidate source of healthy edible sprouts.

  14. Krp1 (Sarcosin) promotes lateral fusion of myofibril assembly intermediates in cultured mouse cardiomyocytes

    SciTech Connect

    Greenberg, Cynthia C.; Connelly, Patricia S.; Daniels, Mathew P.; Horowits, Robert

    2008-03-10

    Krp1, also called sarcosin, is a cardiac and skeletal muscle kelch repeat protein hypothesized to promote the assembly of myofibrils, the contractile organelles of striated muscles, through interaction with N-RAP and actin. To elucidate its role, endogenous Krp1 was studied in primary embryonic mouse cardiomyocytes. While immunofluorescence showed punctate Krp1 distribution throughout the cell, detergent extraction revealed a significant pool of Krp1 associated with cytoskeletal elements. Reduction of Krp1 expression with siRNA resulted in specific inhibition of myofibril accumulation with no effect on cell spreading. Immunostaining analysis and electron microscopy revealed that cardiomyocytes lacking Krp1 contained sarcomeric proteins with longitudinal periodicities similar to mature myofibrils, but fibrils remained thin and separated. These thin myofibrils were degraded by a scission mechanism distinct from the myofibril disassembly pathway observed during cell division in the developing heart. The data are consistent with a model in which Krp1 promotes lateral fusion of adjacent thin fibrils into mature, wide myofibrils and contribute insight into mechanisms of myofibrillogenesis and disassembly.

  15. An electrostatic model with weak actin-myosin attachment resolves problems with the lattice stability of skeletal muscle.

    PubMed

    Smith, D A; Stephenson, D G

    2011-06-01

    The stability of the filament lattice in relaxed striated muscle can be viewed as a balance of electrostatic and van der Waals forces. The simplest electrostatic model, where actin and myosin filaments are treated as charged cylinders, generates reasonable lattice spacings for skinned fibers. However, this model predicts excessive radial stiffness under osmotic pressure and cannot account for the initial pressure (∼1 kPa) required for significant compression. Good agreement with frog compression data is obtained with an extended model, in which S1 heads are weakly attached to actin when the lattice spacing is reduced below a critical value; further compression moves fixed negative charges on the heads closer to the myofilament backbone as they attach at a more acute angle to actin. The model predicts pH data in which the lattice shrinks as pH is lowered and protons bind to filaments. Electrostatic screening implies that the lattice shrinks with increasing ionic strength, but the observed expansion of the frog lattice at ionic strengths above 0.1 M with KCl might be explained if Cl(-) binds to sites on the motor domain of S1. With myosin-myosin and actin-actin interactions, the predicted lattice spacing decreases slightly with sarcomere length, with a more rapid decrease when actin-myosin filament overlap is very small. PMID:21641314

  16. Electron microscopy and three-dimensional reconstruction of native thin filaments reveal species-specific differences in regulatory strand densities

    SciTech Connect

    Cammarato, Anthony; Craig, Roger; Lehman, William

    2010-01-01

    Throughout the animal kingdom striated muscle contraction is regulated by the thin filament troponin-tropomyosin complex. Homologous regulatory components are shared among vertebrate and arthropod muscles; however, unique protein extensions and/or components characterize the latter. The Troponin T (TnT) isoforms of Drosophila indirect flight and tarantula femur muscle for example contain distinct C-terminal extensions and are {approx}20% larger overall than their vertebrate counterpart. Using electron microscopy and three-dimensional helical reconstruction of native Drosophila, tarantula and frog muscle thin filaments we have identified species-specific differences in tropomyosin regulatory strand densities. The strands on the arthropod thin filaments were significantly larger in diameter than those from vertebrates, although not significantly different from each other. These findings reflect differences in the regulatory troponin-tropomyosin complex, which are likely due to the larger TnT molecules aligning and extending along much of the tropomyosin strands' length. Such an arrangement potentially alters the physical properties of the regulatory strands and may help establish contractile characteristics unique to certain arthropod muscles.

  17. Tarantula Myosin Free Head Regulatory Light Chain Phosphorylation Stiffens N-terminal Extension Releasing it and Blocking its Docking Back

    PubMed Central

    Alamo, Lorenzo; Li, Xiaochuan (Edward); Espinoza-Fonseca, L. Michel; Pinto, Antonio; Thomas, David D.; Lehman, William; Padrón, Raúl

    2015-01-01

    Molecular dynamics simulations of smooth and striated muscle myosin regulatory light chain (RLC) N-terminal extension (NTE) showed that diphosphorylation induces a disorder-to-order transition. Our goal here was to further explore the effects of mono- and diphosphorylation on the straightening and rigidification of the tarantula myosin RLC NTE. For that we used MD simulations followed by persistence length analysis to explore the consequences of secondary and tertiary structure changes occurring on RLC NTE following phosphorylation. Static and dynamic persistence lengths analysis of tarantula RLC NTE peptides suggest that diphosphorylation produces an important 24-fold straightening and a 16-fold rigidification of the RLC NTE, while monophosphorylation has a less profound effect. This new information on myosin structural mechanics, not fully revealed by previous EM and MD studies, add support to a cooperative phosphorylation-dependent activation mechanism as proposed for the tarantula thick filament. Our results suggest that the RLC NTE straightening and rigidification after Ser45 phosphorylation leads to a release of the constitutively Ser35 monophosphorylated free head swaying away from the thick filament shaft in the relaxed state. This is so because the stiffened diphosphorylated RLC NTE would hinder the docking back of the free head after swaying away, becoming released and mobile and unable to recover its original interacting position on activation. PMID:26038302

  18. The first elateroid beetles (Coleoptera: Polyphaga: Elateroidea) from the Upper Jurassic of Australia.

    PubMed

    Oberprieler, Rolf G; Ashman, Lauren G; Frese, Michael; Ślipiński, Adam

    2016-01-01

    The first elateroid fossils from the Upper Jurassic Talbragar Fish Bed in Australia are described and illustrated. Wongaroo amplipectorale gen. et sp. n., based on two specimens, is placed in the family Cerophytidae due to its convex, posteriorly weakly angled and laterally carinate pronotum obscuring the head in dorsal view, its relatively long, pointed elytra and slender legs, its 9-striate elytra with deep basal pits and the absence of metacoxal plates. Beattieellus jurassicus gen. et sp. n., described from one specimen, possesses the acutely angled pronotum without a carina on the posterolateral angles and the ventral click apparatus typical of Eucnemidae and is classified in this family. Assignment of it to a eucnemid subfamily is impossible because of the insufficient preservation of relevant characters in the fossil. Four other elateroid fossils, possibly representing eucnemids and elaterids, are illustrated and briefly described but not named, due to their insufficient preservation. These fossils represent the first of their kind in Australia and in the Southern Hemisphere, and Beattieellus is also the oldest eucnemid fossil known and extends the fossil record of Eucnemidae into the Upper Jurassic. The discovery of elateroid fossils in the Talbragar Fish Bed adds to the coleopteran diversity of this ancient lake ecosystem, indicating that it was well wooded and provided suitable habitats of rotten wood for the development of the larvae of these taxa. PMID:27515614

  19. The structure of Ca(2+) release units in arthropod body muscle indicates an indirect mechanism for excitation-contraction coupling.

    PubMed Central

    Takekura, Hiroaki; Franzini-Armstrong, Clara

    2002-01-01

    The relative disposition of ryanodine receptors (RyRs) and L-type Ca(2+) channels was examined in body muscles from three arthropods. In all muscles the disposition of ryanodine receptors in the junctional gap between apposed SR and T tubule elements is highly ordered. By contrast, the junctional membrane of the T tubule is occupied by distinctive large particles that are clustered within the small junctional domain, but show no order in their arrangement. We propose that the large particles of the junctional T tubules represent L-type Ca(2+) channels involved in excitation-contraction (e-c) coupling, based on their similarity in size and location with the L-type Ca(2+) channels or dihydropyridine receptors (DHPRs) of skeletal and cardiac muscle. The random arrangement of DHPRs in arthropod body muscles indicates that there is no close link between them and RyRs. This matches the architecture of vertebrate cardiac muscle and is in keeping with the similarity in e-c coupling mechanisms in cardiac and invertebrate striated muscles. PMID:12414707

  20. Fine Structure of Body Wall Cuticle of Females of Eight Genera of Heteroderidae

    PubMed Central

    Cliff, G. M.; Baldwin, J. G.

    1985-01-01

    Body wall cuticle of adult females of eight genera within the Heteroderidae was examined by transmission electron microscopy for comparison with previously studied species within the family. Cuticle structure was used to test some current hypotheses of phylogeny of Heteroderidae and to evaluate intrageneric variability in cuticle layering. Verutus, Rhizonema, and Meloidodera possess striated cuticle surfaces and have the simplest layering, suggesting that striations have not necessarily arisen repeatedly in Heteroderidae through convergent or parallel evolution. Atalodera and Thecavermiculatus possess similar cuticles with derived characteristics, strengthening the hypothesis that the two genera are sister groups. Similarly, the cuticle of Cactodera resembles the specialized cuticle of Globodera and Punctodera in having a basal layer (D) and a surface layer infused with electron-dense substance. Heterodera betulae has a unique cuticle in which the thickest layer (C) is infiltrated with an electron-dense matrix. Little intrageneric difference was found between cuticles of two species of Meloidodera or between two species of Atalodera. However, Atalodera ucri has a basal layer (E) not found in other Heteroderidae. The most striking intrageneric variation in cuticle structure was observed between the thin three-layered cuticle of Sarisodera africana and the much thicker four-layered cuticle of Sarisodera hydrophila; results do not support monophyly of Sarisodera. PMID:19294096