Labelling of biological structures with technetium 99 m

International Nuclear Information System (INIS)

Bernardo Filho, M.

1988-01-01

The labelling of red blood cells (RBC) with technetium 99m ( 99m Tc) depends on several factors, as the stannous ion (Sn ++ ) concentration, the time and temperature of incubation, the anticoagulant utilized, the presence of plasma proteins (PP) and others. Although the blinding of 99m Tc with hemoglobin and PP are similar, they appear to have specific characteristics as demonstrated by precipitation with alcohol, acetone, trichloroacetic acid, hydrochloric acid and mercury chloride. The bacterial cultures labeled with Technetium- 99m , at optimal Sn ++ ion concentration, presents a large stability and their viability is not altered by this treatment. The electrophoretic mobility, the hydrophobicity, the cationized ferritin distribution and the adherence to human buccal epithelial cells are not modified either. The possibility of labelling with 99m Tc of planaria and cercariae of Schistossoma mansoni evaluative cycle increases the utilization of this radionuclide to an experimental level. The results described with the labelling of these biological structures with 99m Tc demonstrated that stable labeled and viable operations are obtained. (author)

Optically sectioned in vivo imaging with speckle illumination HiLo microscopy

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Lim, Daryl; Ford, Tim N.; Chu, Kengyeh K.; Mertz, Jerome

2011-01-01

We present a simple wide-field imaging technique, called HiLo microscopy, that is capable of producing optically sectioned images in real time, comparable in quality to confocal laser scanning microscopy. The technique is based on the fusion of two raw images, one acquired with speckle illumination and another with standard uniform illumination. The fusion can be numerically adjusted, using a single parameter, to produce optically sectioned images of varying thicknesses with the same raw data. Direct comparison between our HiLo microscope and a commercial confocal laser scanning microscope is made on the basis of sectioning strength and imaging performance. Specifically, we show that HiLo and confocal 3-D imaging of a GFP-labeled mouse brain hippocampus are comparable in quality. Moreover, HiLo microscopy is capable of faster, near video rate imaging over larger fields of view than attainable with standard confocal microscopes. The goal of this paper is to advertise the simplicity, robustness, and versatility of HiLo microscopy, which we highlight with in vivo imaging of common model organisms including planaria, C. elegans, and zebrafish.

WD60/FAP163 is a dynein intermediate chain required for retrograde intraflagellar transport in cilia

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Patel-King, Ramila S.; Gilberti, Renée M.; Hom, Erik F. Y.; King, Stephen M.

2013-01-01

Retrograde intraflagellar transport (IFT) is required for assembly of cilia. We identify a Chlamydomonas flagellar protein (flagellar-associated protein 163 [FAP163]) as being closely related to the D1bIC(FAP133) intermediate chain (IC) of the dynein that powers this movement. Biochemical analysis revealed that FAP163 is present in the flagellar matrix and is actively trafficked by IFT. Furthermore, FAP163 copurified with D1bIC(FAP133) and the LC8 dynein light chain, indicating that it is an integral component of the retrograde IFT dynein. To assess the functional role of FAP163, we generated an RNA interference knockdown of the orthologous protein (WD60) in planaria. The Smed-wd60(RNAi) animals had a severe ciliary assembly defect that dramatically compromised whole-organism motility. Most cilia were present as short stubs that had accumulated large quantities of IFT particle–like material between the doublet microtubules and the membrane. The few remaining approximately full-length cilia had a chaotic beat with a frequency reduced from 24 to ∼10 Hz. Thus WD60/FAP163 is a dynein IC that is absolutely required for retrograde IFT and ciliary assembly. PMID:23864713

SMED-TLX-1 (NR2E1) is critical for tissue and body plan maintenance in Schmidtea mediterranea in fasting/feeding cycles.

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Raška, O; Kostrouchová, V; Behenský, F; Yilma, P; Saudek, V; Kostrouch, Z; Kostrouchová, M

2011-01-01

Nuclear receptors (NRs), or nuclear hormone receptors (NHRs), are transcription factors that regulate development and metabolism of most if not all animal species. Their regulatory networks include conserved mechanisms that are shared in-between species as well as mechanisms that are restricted to certain phyla or even species. In search for conserved members of the NHR family in Schmidtea mediterranea, we identified a molecular signature of a class of NRs, NR2E1, in the S. mediterranea genome and cloned its complete cDNA coding sequence. The derived amino acid sequence shows a high degree of conservation of both DNA-binding domain and ligand- binding domain and a remarkably high homology to vertebrate NR2E1 and C. elegans NHR-67. Quantitative PCR detected approximately ten-fold higher expression of Smed-tlx-1 in the proximal part of the head compared to the tail region. The expression of Smed-tlx-1 is higher during fed state than during fasting. Smed-tlx-1 down-regulation by RNA interference affects the ability of the animals to maintain body plan and induces defects of brain, eyes and body shape during fasting and re-growing cycles. These results suggest that SMED-TLX-1 is critical for tissue and body plan maintenance in planaria.

The natural compound sanguinarine perturbs the regenerative capabilities of planarians.

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Balestrini, Linda; Di Donfrancesco, Alessia; Rossi, Leonardo; Marracci, Silvia; Isolani, Maria E; Bianucci, Anna M; Batistoni, Renata

2017-01-01

The natural alkaloid sanguinarine has remarkable therapeutic properties and has been used for centuries as a folk remedy. This compound exhibits interesting anticancer properties and is currently receiving attention as a potential chemotherapeutic agent. Nevertheless, limited information exists regarding its safety for developing organisms. Planarians are an animal model known for their extraordinary stem cell-based regenerative capabilities and are increasingly used for toxicological and pharmacological studies. Here, we report that sanguinarine, at micromolar concentrations, perturbs the regeneration process in the planarian Dugesia japonica. We show that sanguinarine exposure causes defects during anterior regeneration and visual system recovery, as well as anomalous remodelling of pre-existing structures. Investigating the effects of sanguinarine on stem cells, we found that sanguinarine perturbs the transcriptional profile of early and late stem cell progeny markers. Our results indicate that sanguinarine exposure alters cell dynamics and induces apoptosis without affecting cell proliferation. Finally, sanguinarine exposure influences the expression level of H + , K + -ATPase α subunit, a gene of the P-type-ATPase pump family which plays a crucial role during anterior regeneration in planaria. On the whole, our data reveal that sanguinarine perturbs multiple mechanisms which regulate regeneration dynamics and contribute to a better understanding of the safety profile of this alkaloid in developing organisms.

Identification and Actions of a Novel Third Maresin Conjugate in Tissue Regeneration: MCTR3.

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Jesmond Dalli

Full Text Available Maresin conjugates in tissue regeneration (MCTR are a new family of evolutionarily conserved chemical signals that orchestrate host responses to promote tissue regeneration and resolution of infections. Herein, we identified the novel MCTR3 and established rank order potencies and matched the stereochemistries of MCTR1, MCTR2 and MCTR3 using material prepared by total organic synthesis and mediators isolated from both mouse and human systems. MCTR3 was produced from endogenous substrate by E. coli activated human macrophages and identified in sepsis patients. Each of the three synthetic MCTR dose-dependently (1-100 nM accelerated tissue regeneration in planaria by 0.6-0.9 days. When administered at the onset or peak of inflammation, each of the MCTR promoted resolution of E. coli infections in mice. They increased bacterial phagocytosis by exudate leukocytes (~15-50%, limited neutrophil infiltration (~20-50%, promoted efferocytosis (~30% and reduced eicosanoids. MCTR1 and MCTR2 upregulated human neutrophil and macrophage phagocytic responses where MCTR3 also proved to possess potent actions. These results establish the complete stereochemistry and rank order potencies for MCTR1, MCTR2 and MCTR3 that provide novel resolution moduli in regulating host responses to clear infections and promote tissue regeneration.

Inform: Efficient Information-Theoretic Analysis of Collective Behaviors

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Douglas G. Moore

2018-06-01

Full Text Available The study of collective behavior has traditionally relied on a variety of different methodological tools ranging from more theoretical methods such as population or game-theoretic models to empirical ones like Monte Carlo or multi-agent simulations. An approach that is increasingly being explored is the use of information theory as a methodological framework to study the flow of information and the statistical properties of collectives of interacting agents. While a few general purpose toolkits exist, most of the existing software for information theoretic analysis of collective systems is limited in scope. We introduce Inform, an open-source framework for efficient information theoretic analysis that exploits the computational power of a C library while simplifying its use through a variety of wrappers for common higher-level scripting languages. We focus on two such wrappers here: PyInform (Python and rinform (R. Inform and its wrappers are cross-platform and general-purpose. They include classical information-theoretic measures, measures of information dynamics and information-based methods to study the statistical behavior of collective systems, and expose a lower-level API that allow users to construct measures of their own. We describe the architecture of the Inform framework, study its computational efficiency and use it to analyze three different case studies of collective behavior: biochemical information storage in regenerating planaria, nest-site selection in the ant Temnothorax rugatulus, and collective decision making in multi-agent simulations.

Crayfish Self-Administer Amphetamine in a Spatially Contingent Task

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Udita Datta

2018-05-01

Full Text Available Natural reward is an essential element of any organism’s ability to adapt to environmental variation. Its underlying circuits and mechanisms guide the learning process as they help associate an event, or cue, with the perception of an outcome’s value. More generally, natural reward serves as the fundamental generator of all motivated behavior. Addictive plant alkaloids are able to activate this circuitry in taxa ranging from planaria to humans. With modularly organized nervous systems and confirmed vulnerabilities to human drugs of abuse, crayfish have recently emerged as a compelling model for the study of the addiction cycle, including psychostimulant effects, sensitization, withdrawal, reinstatement, and drug reward in conditioned place preference paradigms. Here we extend this work with the demonstration of a spatially contingent, operant drug self-administration paradigm for amphetamine. When the animal enters a quadrant of the arena with a particular textured substrate, a computer-based control system delivers amphetamine through an indwelling fine-bore cannula. Resulting reward strength, dose-response, and the time course of operant conditioning were assessed. Individuals experiencing the drug contingent on their behavior, displayed enhanced rates of operant responses compared to that of their yoked (non-contingent counterparts. Application of amphetamine near the supra-esophageal ganglion elicited stronger and more robust increases in operant responding than did systemic infusions. This work demonstrates automated implementation of a spatially contingent self-administration paradigm in crayfish, which provides a powerful tool to explore comparative perspectives in drug-sensitive reward, the mechanisms of learning underlying the addictive cycle, and phylogenetically conserved vulnerabilities to psychostimulant compounds.

Ion channel signaling influences cellular proliferation and phagocyte activity during axolotl tail regeneration.

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Franklin, Brandon M; Voss, S Randal; Osborn, Jeffrey L

2017-08-01

Little is known about the potential for ion channels to regulate cellular behaviors during tissue regeneration. Here, we utilized an amphibian tail regeneration assay coupled with a chemical genetic screen to identify ion channel antagonists that altered critical cellular processes during regeneration. Inhibition of multiple ion channels either partially (anoctamin1/Tmem16a, anoctamin2/Tmem16b, K V 2.1, K V 2.2, L-type Ca V channels and H/K ATPases) or completely (GlyR, GABA A R, K V 1.5 and SERCA pumps) inhibited tail regeneration. Partial inhibition of tail regeneration by blocking the calcium activated chloride channels, anoctamin1&2, was associated with a reduction of cellular proliferation in tail muscle and mesenchymal regions. Inhibition of anoctamin 1/2 also altered the post-amputation transcriptional response of p44/42 MAPK signaling pathway genes, including decreased expression of erk1/erk2. We also found that complete inhibition via voltage gated K + channel blockade was associated with diminished phagocyte recruitment to the amputation site. The identification of H + pumps as required for axolotl tail regeneration supports findings in Xenopus and Planaria models, and more generally, the conservation of ion channels as regulators of tissue regeneration. This study provides a preliminary framework for an in-depth investigation of the mechanistic role of ion channels and their potential involvement in regulating cellular proliferation and other processes essential to wound healing, appendage regeneration, and tissue repair. Copyright © 2017 Elsevier B.V. All rights reserved.

The use of invertebrates as indicators of environmental change in alpine rivers and lakes

International Nuclear Information System (INIS)

Khamis, K.; Hannah, D.M.; Brown, L.E.; Tiberti, R.; Milner, A.M.

2014-01-01

In alpine regions climatic change will alter the balance between water sources (rainfall, ice-melt, snowmelt, and groundwater) for aquatic systems, particularly modifying the relative contributions of meltwater, groundwater and rain to both rivers and lakes. While these changes are expected to have implications for alpine aquatic ecosystems, little is known about potential ecological tipping points and associated indicator taxa. We examined changes in biotic communities along a gradient of glacier influence for two study systems: (1) a stream network in the French Pyrénées; and (2) a network of lakes in the Italian Alps, with the aim of identifying potential indicator taxa (macroinvertebrates and zooplankton) of glacier retreat in these environments. To assess parallels in biotic responses across streams and lakes, both primary data and findings from other publications were synthesised. Using TITAN (Threshold Indicator Taxa ANalysis) changes in community composition of river taxa were identified at thresholds of < 5.1% glacier cover and < 66.6% meltwater contribution. Below these thresholds the loss of cold stenothermic benthic invertebrate taxa, Diamesa spp. and the Pyrenean endemic Rhyacophila angelieri was apparent. Some generalist taxa including Protonemura sp., Perla grandis, Baetis alpinus, Rhithrogena loyolaea and Microspectra sp. increased when glacier cover was < 2.7% and < 52% meltwater. Patterns were not as distinct for the alpine lakes, due to fewer sampling sites; however, Daphnia longispina grp. and the benthic invertebrate groups Plectopera and Planaria were identified as potential indicator taxa. While further work is required to assess potential indicator taxa for alpine lake systems, findings from alpine river systems were consistent between methods for assessing glacier influence (meltwater contribution/glacier cover). Hence, it is clear that TITAN could become a useful management tool, enabling: (i) the identification of taxa particularly

The use of invertebrates as indicators of environmental change in alpine rivers and lakes

Energy Technology Data Exchange (ETDEWEB)

Khamis, K.; Hannah, D.M. [School of Geography Earth and Environmental Science, University of Birmingham, Birmingham B15 2TT (United Kingdom); Brown, L.E. [School of Geography/water@leeds, University of Leeds, Woodhouse Lane, Leeds LS2 9JT (United Kingdom); Tiberti, R. [DSTA, Dipartimento di Scienze della Terra e dell' Ambiente, University of Pavia, Via Ferrata 9, 27100 Pavia (Italy); Alpine Wildlife Research Centre, Gran Paradiso National Park, Degioz 11, I-1101 Valsavarenche, Aosta (Italy); Milner, A.M., E-mail: a.m.milner@bham.ac.uk [School of Geography Earth and Environmental Science, University of Birmingham, Birmingham B15 2TT (United Kingdom); Institute of Arctic Biology, University of Alaska, Fairbanks, AK 99775 (United States)

2014-09-15

In alpine regions climatic change will alter the balance between water sources (rainfall, ice-melt, snowmelt, and groundwater) for aquatic systems, particularly modifying the relative contributions of meltwater, groundwater and rain to both rivers and lakes. While these changes are expected to have implications for alpine aquatic ecosystems, little is known about potential ecological tipping points and associated indicator taxa. We examined changes in biotic communities along a gradient of glacier influence for two study systems: (1) a stream network in the French Pyrénées; and (2) a network of lakes in the Italian Alps, with the aim of identifying potential indicator taxa (macroinvertebrates and zooplankton) of glacier retreat in these environments. To assess parallels in biotic responses across streams and lakes, both primary data and findings from other publications were synthesised. Using TITAN (Threshold Indicator Taxa ANalysis) changes in community composition of river taxa were identified at thresholds of < 5.1% glacier cover and < 66.6% meltwater contribution. Below these thresholds the loss of cold stenothermic benthic invertebrate taxa, Diamesa spp. and the Pyrenean endemic Rhyacophila angelieri was apparent. Some generalist taxa including Protonemura sp., Perla grandis, Baetis alpinus, Rhithrogena loyolaea and Microspectra sp. increased when glacier cover was < 2.7% and < 52% meltwater. Patterns were not as distinct for the alpine lakes, due to fewer sampling sites; however, Daphnia longispina grp. and the benthic invertebrate groups Plectopera and Planaria were identified as potential indicator taxa. While further work is required to assess potential indicator taxa for alpine lake systems, findings from alpine river systems were consistent between methods for assessing glacier influence (meltwater contribution/glacier cover). Hence, it is clear that TITAN could become a useful management tool, enabling: (i) the identification of taxa particularly

Theoretical computer science and the natural sciences

Science.gov (United States)

Marchal, Bruno

2005-12-01

I present some fundamental theorems in computer science and illustrate their relevance in Biology and Physics. I do not assume prerequisites in mathematics or computer science beyond the set N of natural numbers, functions from N to N, the use of some notational conveniences to describe functions, and at some point, a minimal amount of linear algebra and logic. I start with Cantor's transcendental proof by diagonalization of the non enumerability of the collection of functions from natural numbers to the natural numbers. I explain why this proof is not entirely convincing and show how, by restricting the notion of function in terms of discrete well defined processes, we are led to the non algorithmic enumerability of the computable functions, but also-through Church's thesis-to the algorithmic enumerability of partial computable functions. Such a notion of function constitutes, with respect to our purpose, a crucial generalization of that concept. This will make easy to justify deep and astonishing (counter-intuitive) incompleteness results about computers and similar machines. The modified Cantor diagonalization will provide a theory of concrete self-reference and I illustrate it by pointing toward an elementary theory of self-reproduction-in the Amoeba's way-and cellular self-regeneration-in the flatworm Planaria's way. To make it easier, I introduce a very simple and powerful formal system known as the Schoenfinkel-Curry combinators. I will use the combinators to illustrate in a more concrete way the notion introduced above. The combinators, thanks to their low-level fine grained design, will also make it possible to make a rough but hopefully illuminating description of the main lessons gained by the careful observation of nature, and to describe some new relations, which should exist between computer science, the science of life and the science of inert matter, once some philosophical, if not theological, hypotheses are made in the cognitive sciences. In the

Redescripción y algunos aspectos ecológicos de Girardia tigrina, G. cameliae y G. paramensis (Dugesiidae, Tricladida en Antioquia, Colombia Redescription and some ecological aspects of Girardia tigrina, G. cameliae y G. paramensis (Dugesiidae, Tricladida in Antioquia, Colombia

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Mauricio A Muñoz

2007-12-01

Full Text Available Turbellaria está integrada por 2 órdenes: Catenulida y Rhabditophora. Dentro del último, el suborden Paludicola comprende las familias Dendrocoelidae, Dugesiidae y Planariidae. En este estudio fueron encontradas: Girardia cameliae, G. paramensis y G. tigrina (Dugesiidae. Fueron analizados 22 sistemas acuáticos (captura manual en zonas de remanso del centro y sur oriente de Antioquia. En 3 individuos por especie, se hizo descripción de: ancho, longitud y color corporal; forma y tamaño de cabeza; posición auricular; distancia entre manchas oculares; longitud y posición de faringe. Se efectuó análisis histológico de: gonoporo; bulbo, papila, glándulas y lúmen peneal; vesículas seminales y vasos deferentes; atrio masculino; testículos; canal bursal y bolsa copuladora; ovario y oviductos; glándulas de la cáscara. Se midieron: oxigeno disuelto, pH, conductividad y dureza en el agua. Se realizó reconstrucción gráfica de órganos reproductivos (caracteres taxonómicos en cortes histológicos seriados. G. tigrina y G. paramensis, presentaron amplia distribución geográfica. Estas especies consumieron ex situ: Daphnia pulex, Chironomus sp., Culex sp. y Drosophila sp. (estados larvales. Tales planarias prefirieron aguas clase II y III (según BMWP/Col. Los aspectos físicos y químicos no exhibieron diferencias entre las preferencias de las especies. G. cameliae se encontró en una sola localidad en condiciones particulares.The Turbellaria comprises 2 orders: Catenulida and Rhabditophora. In the latter, the suborder Paludicola contains the families Dendrocoelidae, Dugesiidae and Planariidae. In this study, we found Girardia cameliae, Girardia paramensis and Giardia tigrina (Dugesiidae in 22 aquatic systems using manual capture in river ponds zones of central and southeastern Antioquia. In 3 individuals per species, a description of: corporal color, length, and wide; head form and size; auricles position; intraocular distance; pharynx

Regeneración biológica: Secretos de la naturaleza Biological regeneration: Secrets of nature

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Porfirio Hernández Ramírez

2006-12-01

Full Text Available En mayor o menor grado la naturaleza ha proporcionado capacidad regenerativa a diferentes organismos, tanto en el campo de la botánica como en el de la zoología. Entre los nuevos métodos para mejorar las características y propagación de las plantas están las técnicas de regeneración de plantas in vitro, que incluyen la organogénesis y la embriogénesis somática que da la posibilidad de formar las llamadas “semillas artificiales”. En el campo de la zoología también se ha observado la capacidad regenerativa de algunos animales, entre ellos las planarias, las hidras, las estrellas de mar y los crustáceos. Muchos vertebrados han perdido, al menos de una forma significativa, la potencialidad regenerativa de la mayor parte de sus tejidos y órganos. Sin embargo, algunos han retenido una notable habilidad regenerativa, entre ellos los peces teleósteos, los urodelos (salamandras y tritones y otros tipos de anfibios. Los quelonios, cocodrilos y serpientes han perdido en general la capacidad de regenerar partes perdidas. Los lagartos, tienen posibilidad de regenerar la cola. Los mamíferos tienen también limitaciones, ya que no pueden regenerar extremidades, órganos y tejidos de la misma forma que lo hacen algunos animales inferiores. Sin embargo, hay excepciones, entre las que se encuentran los ciervos, el delfín y algunos tipos de ratones como los de la línea MRL. El ser humano expresa solo algunos procesos regenerativos fisiológicos o ante algunas lesiones, que se manifiestan fundamentalmente en las células epidérmicas, de la mucosa oral y del tracto respiratorio, las células sanguíneas, el pelo, las uñas, el tejido muscular, la piel y el tejido óseo. Los nuevos conocimientos sobre las células madre han abierto una nueva era que ofrece al hombre posibilidad de influir terapéuticamente en la regeneración de órganos y tejidosIn a greater or lesser extent, nature has provided different organisms with the regenerative