Science.gov

Sample records for leeches

  1. Annelida, Euhirudinea (leeches)

    EPA Science Inventory

    Worldwide, there are over 600 species of leeches described which occur in freshwater, marine, estuarine, and moist-terrestrial ecosystems. Leeches are included in the Class Clitellata, Subclass Hirudinida, and Superorder Euhirudinea. Seven of the ten families of leeches occur in...

  2. Leech Therapeutic Applications

    PubMed Central

    Abdualkader, A. M.; Ghawi, A. M.; Alaama, M.; Awang, M.; Merzouk, A.

    2013-01-01

    Hematophagous animals including leeches have been known to possess biologically active compounds in their secretions, especially in their saliva. The blood-sucking annelids, leeches have been used for therapeutic purposes since the beginning of civilization. Ancient Egyptian, Indian, Greek and Arab physicians used leeches for a wide range of diseases starting from the conventional use for bleeding to systemic ailments, such as skin diseases, nervous system abnormalities, urinary and reproductive system problems, inflammation, and dental problems. Recently, extensive researches on leech saliva unveiled the presence of a variety of bioactive peptides and proteins involving antithrombin (hirudin, bufrudin), antiplatelet (calin, saratin), factor Xa inhibitors (lefaxin), antibacterial (theromacin, theromyzin) and others. Consequently, leech has made a comeback as a new remedy for many chronic and life-threatening abnormalities, such as cardiovascular problems, cancer, metastasis, and infectious diseases. In the 20th century, leech therapy has established itself in plastic and microsurgery as a protective tool against venous congestion and served to salvage the replanted digits and flaps. Many clinics for plastic surgery all over the world started to use leeches for cosmetic purposes. Despite the efficacious properties of leech therapy, the safety, and complications of leeching are still controversial. PMID:24019559

  3. Ocular leech infestation

    PubMed Central

    Lee, Yueh-Chang; Chiu, Cheng-Jen

    2015-01-01

    This case report describes a female toddler with manifestations of ocular leech infestation. A 2-year-old girl was brought to our outpatient clinic with a complaint of irritable crying after being taken to a stream in Hualien 1 day previous, where she played in the water. The parents noticed that she rubbed her right eye a lot. Upon examination, the girl had good fix and follow in either eye. Slit-lamp examination showed conjunctival injection with a moving dark black–brown foreign body partly attached in the lower conjunctiva. After applying topical anesthetics, the leech, measuring 1 cm in length, was extracted under a microscope. The patient began using topical antibiotic and corticosteroid agents. By 1 week after extraction, the patient had no obvious symptoms or signs, except for a limited subconjunctival hemorrhage, and no corneal/scleral involvement was observed. PMID:25784786

  4. Satellite stabilization using space leeches

    NASA Technical Reports Server (NTRS)

    Walker, Michael W.; Kim, Dong-Min

    1990-01-01

    A control algorithm for satellite stabilization using a space leech is presented. The space leech is assumed to have n reaction wheels with known moments of inertia about their axis of rotation. All mass properties of the satellite are assumed to be unknown. The algorithm brings the satellite to a specified attitude trajectory. Simulations were performed to demonstrate the controller. The model parameters and specific algorithm used and the results obtained are presented.

  5. LEECHES (ANNELIDA: EUHIRUDINEA) OF NORTHERN ARKANSAS

    EPA Science Inventory

    Twenty-one lotic and lentic environments throughout central and northern Arkansas were surveyed for the presence of leeches during June 2004, and April, July - October, 2005. Fourteen species of leeches (Desserobdella cryptobranchii, Desserobdella phalera, Desserobdella picta, H...

  6. [Design of an electronic leech].

    PubMed

    Lomelí-Mejía, Pedro Alejandro; Domínguez-Rubio, René; Espinosa-Gutiérrez, Alejandro; Lecona-Butrón, Hugo; Rodríguez-Reyna, Reynaldo Manuel

    2014-07-01

    This research presents the development of a continual suction electromechanical device (CSED) which emulates the feeding characteristics of a medicinal leech to drain body fluids. After the research, design and building of the device, its performance in normal conditions with fluids of different viscosity was evaluated. Finally, the device was submitted to a test of blood draining in three adult male rabbits NZW with a weight of three kilograms, obtaining drain.

  7. Leeches run cold, then hot

    PubMed Central

    Petersen, Ann M.; Chin, Wendy; Feilich, Kara L.; Jung, Grace; Quist, Jessica L.; Wang, Jasmine; Ellerby, David J.

    2011-01-01

    Food processing is costly, potentially limiting the energy and time devoted to other essential functions such as locomotion or reproduction. In ectotherms, post-prandial thermophily, the selection of a warm environmental temperature after feeding, may be advantageous in minimizing the duration of this elevated cost. Although present in many vertebrate taxa, this behaviour had not previously been observed in invertebrates. Sanguivorous leeches ingest large blood meals that are costly to process and limit mobility until excess fluid can actively be expelled to reduce body volume. When presented with a temperature gradient from 10°C to 30°C, leeches select a temperature that is significantly warmer (24.3 ± 0.9°C, n = 6) than their acclimation temperature (Ta, 21°C). Unfed leeches preferred temperatures that were significantly cooler than ambient (12.8 ± 0.9°C, n = 6). This behavioural strategy is consistent with minimizing the time course of elevated post-feeding energy costs and reducing energy expenditure during fasting. Our observations raise the possibility that thermoregulatory behaviour of this type is an unrecognized feature of other invertebrate taxa. PMID:21551223

  8. Ciprofloxacin-resistant Aeromonas hydrophila cellulitis following leech therapy.

    PubMed

    Giltner, Carmen L; Bobenchik, April M; Uslan, Daniel Z; Deville, Jaime G; Humphries, Romney M

    2013-04-01

    We report a case of surgical site infection with ciprofloxacin-resistant Aeromonas hydrophila following leech therapy. Antimicrobial and genetic analyses of leech and patient isolates demonstrated that the resistant isolates originated from the leech gut microbiota. These data suggest that ciprofloxacin monotherapy as a prophylaxis regimen prior to leech therapy may not be effective in preventing infection.

  9. Ciprofloxacin-Resistant Aeromonas hydrophila Cellulitis following Leech Therapy

    PubMed Central

    Giltner, Carmen L.; Bobenchik, April M.; Uslan, Daniel Z.; Deville, Jaime G.

    2013-01-01

    We report a case of surgical site infection with ciprofloxacin-resistant Aeromonas hydrophila following leech therapy. Antimicrobial and genetic analyses of leech and patient isolates demonstrated that the resistant isolates originated from the leech gut microbiota. These data suggest that ciprofloxacin monotherapy as a prophylaxis regimen prior to leech therapy may not be effective in preventing infection. PMID:23363826

  10. Reproductive strategies of the kangaroo leech, Marsupiobdella africana (Glossiphoniidae)

    PubMed Central

    Kruger, Natasha; Du Preez, Louis

    2015-01-01

    The Kangaroo Leech, Marsupiobdella africana, is a hermaphroditic organism, with insemination taking place by the planting of a spermatophore on another leech. Spermatophores are mostly planted on the anterior of the recipient leech, but not always. Several spermatophores may be planted by different leeches on a single recipient. The spermatophore consists of two side by side lobes. Within minutes from planting of the spermatophore, the contents are squeezed out and into the body of the recipient. Sperm are believed to find the way to the ova by following chemical cues. Kangaroo Leeches display advanced parental care by transferring fertilized eggs from the reproductive opening to a brood pouch on the ventral side. Fully developed leeches may copulate after detaching from the amphibian host Xenopus laevis, or from the Cape River Crab Potamonautes perlatus with which it maintains a phoretic association. PMID:25830114

  11. External decontamination of wild leeches with hypochloric acid

    PubMed Central

    Aydin, Atakan; Nazik, Hasan; Kuvat, Samet Vasfi; Gurler, Nezahat; Ongen, Betigul; Tuncer, Serdar; Hocaoglu, Emre; Kesim, Sinan Nur

    2004-01-01

    Background Medicinal leech, Hirudo medicinalis, has been used in plastic and reconstructive surgery, to relieve venous congestion and to improve the microrevascularization of flaps. In many countries, wild leeches are still provided from local markets and utilised with antibiotic prophylaxies. In this research, results of identification of bacteria in the transport fluid is reported, oral and intestinal floras and the antibiograms of the identified microorganisms are investigated. Also, to avoid possible infections, the ability of hypochloric acid, a disinfectant, to suppress the relevant microorganisms without changing the life style and behavior of leeches in terms of sucking function, is investigated. Methods Bacterial identifications and antibiograms of oral and intestinal flora and transport medium were performed for 10 leeches. The optimum concentration of hypochloric acid which eliminated microorganisms without affecting the viability and sucking function of the leeches were determined by dilution of hypochloric acid to 100, 50, 25, 12.5, 6.25 ppm concentrations in different groups of 25 leeches. Finally, 20 leeches were applied atraumatically to the bleeding areas of rats, the duration of suction was determined and compared statistically between the leeches treated and not treated with hypochloric acid solution. Results Aeromonas hydrophilia was the most commonly identified microorganism and found to be resistant to first generation cephalosporins, frequently used in prophylaxis at surgical wards. In the next stages of the study, the leeches were subjected to a series of diluted hypochloric acid solutions. Although disinfection of the transport material and suppression of the oral flora of hirudo medicinalis were successful in 100, 50, 25, 12.5, 6.25 ppm concentrations; 12.5 ppm solution was the greatest concentration in which hirudo medicinalis could survive and sucking function was not affected significantly. Conclusions External decontamination of wild

  12. The eyes have it: long-distance dispersal by an intraorbital leech parasite of birds.

    PubMed

    Siddall, Mark E; Rood-Goldman, Rebecca; Barrio, Amalie; Barboutis, Christos

    2013-12-01

    A leech was found parasitizing the ocular orbit of a common redstart captured during a faunistic survey of Antikythira in the Aegean Sea during the spring migration of 2012. Morphological and molecular characterizations placed the leech in the mucous-membrane specific leech family Praobdellidae and definitively as the species Parapraobdella lineata. This is the first record of any leech parasitizing a passerine bird, Phoenicurus phoenicurus , and the first of a praobdellid leech on any avian host.

  13. 33 CFR 207.330 - Mississippi River between Winnibigoshish and Pokegama dams, Leech River between outlet of Leech...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Mississippi River between Winnibigoshish and Pokegama dams, Leech River between outlet of Leech Lake and Mississippi River, and Pokegama... OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.330 Mississippi River...

  14. 33 CFR 207.330 - Mississippi River between Winnibigoshish and Pokegama dams, Leech River between outlet of Leech...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Mississippi River between Winnibigoshish and Pokegama dams, Leech River between outlet of Leech Lake and Mississippi River, and Pokegama... OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.330 Mississippi River...

  15. 33 CFR 207.330 - Mississippi River between Winnibigoshish and Pokegama dams, Leech River between outlet of Leech...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Mississippi River between Winnibigoshish and Pokegama dams, Leech River between outlet of Leech Lake and Mississippi River, and Pokegama... OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.330 Mississippi River...

  16. 33 CFR 207.330 - Mississippi River between Winnibigoshish and Pokegama dams, Leech River between outlet of Leech...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Mississippi River between Winnibigoshish and Pokegama dams, Leech River between outlet of Leech Lake and Mississippi River, and Pokegama... OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.330 Mississippi River...

  17. 33 CFR 207.330 - Mississippi River between Winnibigoshish and Pokegama dams, Leech River between outlet of Leech...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Mississippi River between Winnibigoshish and Pokegama dams, Leech River between outlet of Leech Lake and Mississippi River, and Pokegama... OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.330 Mississippi River...

  18. Developmental biology of the leech Helobdella

    PubMed Central

    WEISBLAT, DAVID A.; KUO, DIAN-HAN

    2015-01-01

    Glossiphoniid leeches of the genus Helobdella provide experimentally tractable models for studies in evolutionary developmental biology (Evo-Devo). Here, after a brief rationale, we will summarize our current understanding of Helobdella development and highlight the near term prospects for future investigations, with respect to the issues of: D quadrant specification; the transition from spiral to bilaterally symmetric cleavage; segmentation, and the connections between segmental and non-segmental tissues; modifications of BMP signaling in dorsoventral patterning and the O-P equivalence group; germ line specification and genome rearrangements. The goal of this contribution is to serve as a summary of, and guide to, published work. PMID:25690960

  19. Leeches--the good, the bad and the wiggly.

    PubMed

    O'Dempsey, Tim

    2012-11-01

    Leeches have been making a remarkable come-back in medical practice in recent years, particularly in reconstructive surgery. This paper opens with a brief review of the historical aspects of the medicinal use of leeches and their recent renaissance in modern medical practice. We then embark on a journey through the murky waters of leech infestation and the potentially life-threatening complications arising from close encounters with these extraordinary creatures. Finally, we get to grips with the tricky issue of safely apprehending and removing uninvited hangers-on.

  20. Micromere lineages in the glossiphoniid leech Helobdella

    NASA Technical Reports Server (NTRS)

    Huang, Francoise Z.; Kang, Dongmin; Ramirez-Weber, Felipe-Andres; Bissen, Shirley T.; Weisblat, David A.

    2002-01-01

    In leech embryos, segmental mesoderm and ectoderm arise from teloblasts by lineages that are already relatively well characterized. Here, we present data concerning the early divisions and the definitive fate maps of the micromeres, a group of 25 small cells that arise during the modified spiral cleavage in leech (Helobdella robusta) and contribute to most of the nonsegmental tissues of the adult. Three noteworthy results of this work are as follows. (1) The c"' and dm' clones (3d and 3c in traditional nomenclature) give rise to a hitherto undescribed network of fibers that run from one end of the embryo to the other. (2) The clones of micromeres b" and b"' (2b and 3b in traditional nomenclature) die in normal development; the b" clone can be rescued to assume the normal c" fate if micromere c" or its clone are ablated in early development. (3) Two qualitative differences in micromere fates are seen between H. robusta (Sacramento) and another Helobdella sp. (Galt). First, in Helobdella sp. (Galt), the clone of micromere b" does not normally die, and contributes a subset of the cells arising exclusively from c" in H. robusta (Sacramento). Second, in Helobdella sp. (Galt), micromere c"' makes no definitive contribution, whereas micromere dm' gives rise to cells equivalent to those arising from c"' and dm' in H. robusta (Sacramento).

  1. Calcium dynamics and compartmentalization in leech neurons.

    PubMed

    Andjelic, Sofija; Torre, Vincent

    2005-12-01

    Calcium dynamics in leech neurons were studied using a fast CCD camera. Fluorescence changes (DeltaF/F) of the membrane impermeable calcium indicator Oregon Green were measured. The dye was pressure injected into the soma of neurons under investigation. DeltaF/F caused by a single action potential (AP) in mechanosensory neurons had approximately the same amplitude and time course in the soma and in distal processes. By contrast, in other neurons such as the Anterior Pagoda neuron, the Annulus Erector motoneuron, the L motoneuron, and other motoneurons, APs evoked by passing depolarizing current in the soma produced much larger fluorescence changes in distal processes than in the soma. When APs were evoked by stimulating one distal axon through the root, DeltaF/F was large in all distal processes but very small in the soma. Our results show a clear compartmentalization of calcium dynamics in most leech neurons in which the soma does not give propagating action potentials. In such cells, the soma, while not excitable, can affect information processing by modulating the sites of origin and conduction of AP propagation in distal excitable processes.

  2. NEW HOST DATA FOR THE LEECH OLIGOBDELLA BIANNULATE (EUHIRUDINEA: GLOSSIPHONIIDAE)

    EPA Science Inventory

    The leech Oligobdella biannulata is a relatively rare species, endemic to mountain streams of the Southern Blue Ridge Physiographic Zone, exclusive of Virginia. Oligobdella biannulata was originally thought to be host specific to Desmognathus quadramaculatus. However, the host ...

  3. Intermediate filament genes as differentiation markers in the leech Helobdella.

    PubMed

    Kuo, Dian-Han; Weisblat, David A

    2011-10-01

    The intermediate filament (IF) cytoskeleton is a general feature of differentiated cells. Its molecular components, IF proteins, constitute a large family including the evolutionarily conserved nuclear lamins and the more diverse collection of cytoplasmic intermediate filament (CIF) proteins. In vertebrates, genes encoding CIFs exhibit cell/tissue type-specific expression profiles and are thus useful as differentiation markers. The expression of invertebrate CIFs, however, is not well documented. Here, we report a whole-genome survey of IF genes and their developmental expression patterns in the leech Helobdella, a lophotrochozoan model for developmental biology research. We found that, as in vertebrates, each of the leech CIF genes is expressed in a specific set of cell/tissue types. This allows us to detect earliest points of differentiation for multiple cell types in leech development and to use CIFs as molecular markers for studying cell fate specification in leech embryos. In addition, to determine the feasibility of using CIFs as universal metazoan differentiation markers, we examined phylogenetic relationships of IF genes from various species. Our results suggest that CIFs, and thus their cell/tissue-specific expression patterns, have expanded several times independently during metazoan evolution. Moreover, comparing the expression patterns of CIF orthologs between two leech species suggests that rapid evolutionary changes in the cell or tissue specificity of CIFs have occurred among leeches. Hence, CIFs are not suitable for identifying cell or tissue homology except among very closely related species, but they are nevertheless useful species-specific differentiation markers.

  4. On exploration of geometrically constrained space by medicinal leeches Hirudo verbana.

    PubMed

    Adamatzky, Andrew

    2015-04-01

    Leeches are fascinating creatures: they have simple modular nervous circuitry yet exhibit a rich spectrum of behavioural modes. Leeches could be ideal blue-prints for designing flexible soft robots which are modular, multi-functional, fault-tolerant, easy to control, capable for navigating using optical, mechanical and chemical sensorial inputs, have autonomous inter-segmental coordination and adaptive decision-making. With future designs of leech-robots in mind we study how leeches behave in geometrically constrained spaces. Core results of the paper deal with leeches exploring a row of rooms arranged along a narrow corridor. In laboratory experiments we find that rooms closer to ends of the corridor are explored by leeches more often than rooms in the middle of the corridor. Also, in series of scoping experiments, we evaluate leeches capabilities to navigating in mazes towards sources of vibration and chemo-attraction. We believe our results lay foundation for future developments of robots mimicking behaviour of leeches.

  5. Bed bugs, leeches and hookworm larvae in the skin.

    PubMed

    Heukelbach, Jorg; Hengge, Ulrich R

    2009-01-01

    Bed bugs, leeches, and hookworm-related cutaneous larva migrans are skin infestations that are usually considered of minor importance because they produce discomfort rather than cause or transmit disease. Bed bugs have been increasing tremendously in high-income countries in recent years, causing distress to affected individuals and economic loss. Infestation by land leeches causes mainly unpleasant skin reactions, whereas infestation by aquatic leeches may be more dangerous, leading to anemia and in severe cases, to death. Cutaneous larva migrans produces an intense pruritus that can be exasperating for the patient and cause sleep disturbance. An overview is given of these three infestations with a discussion of the causative agents, transmission, clinical manifestations, diagnosis, and treatment.

  6. Bronchial Leech Infestation in a 15-Year-Old Female

    PubMed Central

    Moslehi, Mohammad Ashkan; Imanieh, Mohammad Hadi

    2016-01-01

    Foreign body aspiration (FBA) is a common incidence in young children. Leeches are rarely reported as FBA at any age. This study describes a 15-year-old female who presented with hemoptysis, hematemesis, coughs, melena, and anemia seven months prior to admission. Chest X-ray showed a round hyperdensity in the right lower lobe. A chest computed tomography (CT) demonstrated an area of consolidation and surrounding ground glass opacities in the right lower lobe. Hematological investigations revealed anemia. Finally, bronchoscopy was performed and a 5 cm leech was found within the right B7-8 bronchus and removed by forceps and a Dormia basket. PMID:27752380

  7. Bronchial Leech Infestation in a 15-Year-Old Female.

    PubMed

    Moslehi, Mohammad Ashkan; Imanieh, Mohammad Hadi; Adib, Ali

    2016-01-01

    Foreign body aspiration (FBA) is a common incidence in young children. Leeches are rarely reported as FBA at any age. This study describes a 15-year-old female who presented with hemoptysis, hematemesis, coughs, melena, and anemia seven months prior to admission. Chest X-ray showed a round hyperdensity in the right lower lobe. A chest computed tomography (CT) demonstrated an area of consolidation and surrounding ground glass opacities in the right lower lobe. Hematological investigations revealed anemia. Finally, bronchoscopy was performed and a 5 cm leech was found within the right B7-8 bronchus and removed by forceps and a Dormia basket.

  8. Entrainment of leech swimming activity by the ventral stretch receptor.

    PubMed

    Yu, Xintian; Friesen, W Otto

    2004-11-01

    Rhythmic animal movements originate in CNS oscillator circuits; however, sensory inputs play an important role in shaping motor output. Our recent studies demonstrated that leeches with severed nerve cords swim with excellent coordination between the two ends, indicating that sensory inputs are sufficient for maintaining intersegmental coordination. In this study, we examined the neuronal substrates that underlie intersegmental coordination via sensory mechanisms. Among the identified sensory neurons in the leech, we found the ventral stretch receptor (VSR) to be the best candidate for our study because of its sensitivity to tension in longitudinal muscle. Our experiments demonstrate that (1) the membrane potential of the VSR is depolarized during swimming and oscillates with an amplitude of 1.5-5.0 mV, (2) rhythmic currents injected into the VSR can entrain ongoing swimming over a large frequency range (0.9-1.8 Hz), and (3) large current pulses injected into the VSR shift the phase of the swimming rhythm. These results suggest that VSRs play an important role in generating and modulating the swim rhythm. We propose that coordinated swimming in leech preparations with severed nerve cords results from mutual entrainment between the two ends of the leech mediated by stretch receptors.

  9. Serotonin modulates muscle function in the medicinal leech Hirudo verbana

    PubMed Central

    Gerry, Shannon P.; Ellerby, David J.

    2011-01-01

    The body wall muscles of sanguivorous leeches power mechanically diverse behaviours: suction feeding, crawling and swimming. These require longitudinal muscle to exert force over an extremely large length range, from 145 to 46 per cent of the mean segmental swimming length. Previous data, however, suggest that leech body wall muscle has limited capacity for force production when elongated. Serotonin (5-HT) alters the passive properties of the body wall and stimulates feeding. We hypothesized that 5-HT may also have a role in allowing force production in elongated muscle by changing the shape of the length–tension relationship (LTR). LTRs were measured from longitudinal muscle strips in vitro in physiological saline with and without the presence of 10 µM 5-HT. The LTR was much broader than previously measured for leech muscle. Rather than shifting the LTR, 5-HT reduced passive muscle tonus and increased active stress at all lengths. In addition to modulating leech behaviour and passive mechanical properties, 5-HT probably enhances muscle force and work production during locomotion and feeding. PMID:21561963

  10. [Study on the processing of leech by FTIR and 2D-IR correlation spectroscopy].

    PubMed

    Li, Bing-Ning; Wu, Yan-Wen; Ouyang, Jie; Sun, Su-Qin; Chen, Shun-Cong

    2011-04-01

    The chemical differences of traditional Chinese medicine leech before and after processing were analyzed by FTIR and two-dimensional correlation infrared (2D-IR) spectroscopy. The result showed that the leech was high in protein, with characteristic peaks of amide I, II bands. Comparing the IR spectra of samples, the primary difference was that the characteristic peak of fresh leech was at 1 543 cm(-1), while that of crude and processed leech was at 1 535 cm(-1). A 2D-IR spectrum with heating perturbation was used to track the processing dynamics of leech In the 2D-IR correlation spectra, fresh leech exhibited stronger automatic peaks of the amide I and II bands than that of processed leech, which indicates that the protein components of the fresh leech were more sensitive to heat perturbation than the processed one. Moreover, the result of FTIR and 2D-IR correlation spectra validated that the 3-dimensional structure of protein was damaged and hydrogen bonds were broken after processing, which resulted in the inactivation of protein. The fatty acids and cholesterol components of leech were also oxidized in this process.

  11. An improved anti-leech mechanism based on session identifier

    NASA Astrophysics Data System (ADS)

    Zhang, Jianbiao; Zhu, Tong; Zhang, Han; Lin, Li

    2011-12-01

    With the rapid development of information technology and extensive requirement of network resource sharing, plenty of resource hotlinking phenomenons appear on the internet. The hotlinking problem not only harms the interests of legal websites but also leads to a great affection to fair internet environment. The anti-leech technique based on session identifier is highly secure, but the transmission of session identifier in plaintext form causes some security flaws. In this paper, a proxy hotlinking technique based on session identifier is introduced firstly to illustrate these security flaws; next, this paper proposes an improved anti-leech mechanism based on session identifier, the mechanism takes the random factor as the core and detects hotlinking request using a map table that contains random factor, user's information and time stamp; at last the paper analyzes the security of mechanism in theory. The result reveals that the improved mechanism has the merits of simple realization, high security and great flexibility.

  12. An improved anti-leech mechanism based on session identifier

    NASA Astrophysics Data System (ADS)

    Zhang, Jianbiao; Zhu, Tong; Zhang, Han; Lin, Li

    2012-01-01

    With the rapid development of information technology and extensive requirement of network resource sharing, plenty of resource hotlinking phenomenons appear on the internet. The hotlinking problem not only harms the interests of legal websites but also leads to a great affection to fair internet environment. The anti-leech technique based on session identifier is highly secure, but the transmission of session identifier in plaintext form causes some security flaws. In this paper, a proxy hotlinking technique based on session identifier is introduced firstly to illustrate these security flaws; next, this paper proposes an improved anti-leech mechanism based on session identifier, the mechanism takes the random factor as the core and detects hotlinking request using a map table that contains random factor, user's information and time stamp; at last the paper analyzes the security of mechanism in theory. The result reveals that the improved mechanism has the merits of simple realization, high security and great flexibility.

  13. Spontaneous Electrical Activity and Behavior in the Leech Hirudo Medicinalis

    PubMed Central

    Garcia-Perez, Elizabeth; Mazzoni, Alberto; Torre, Vincent

    2007-01-01

    In the absence of external stimuli, animals explore the environment by performing irregular movements, but the neuronal mechanisms underlying this arrhythmic motion are largely unknown. In this paper, we studied the relationship between the spontaneous neuronal activity in the leech (Hirudo medicinalis) and its behavior. We analyzed the electrical activity of isolated ganglia, chains of two connected ganglia, and semi-intact preparations. The spontaneous electrical activity in ganglia was characterized by the occurrence of irregular bursts of spikes with variable duration and size. Properties of these bursts were modified by synaptic inputs arriving from the neighboring ganglia and from the two primitive brains located in the head and tail. In fact, in semi-intact preparations, unusually large bursts of spikes occurring spontaneously were recorded and caused the leech to move even in the absence of any external sensory stimulation. These large bursts appear to act as internal triggers controlling the spontaneous leech behavior and determining the duration of stereotypical motor patterns. PMID:18958236

  14. Occurrence of three leech species (Annelida: Hirudinida) on fishes in the Kentucky River

    EPA Science Inventory

    Leeches were collected from six fish species distributed among four of ten sites sampled. The leech species observed were Myzobdella reducta (Meyer, 1940) and Myzobdella lugubris Leidy, 1851 of the family Piscicolidae and Placobdella pediculata Hemingway, 1908 of the family Gloss...

  15. Johann Friedrich Dieffenbach: successful use of leeches in plastic surgery in the 1820s.

    PubMed

    Sawyer, R T

    2000-04-01

    Johann Friedrich Dieffenbach (1792-1847) regularly and successfully utilised leeches in sophisticated plastic surgery in Berlin in the 1820s and 1830s, well before anaesthesia, antisepsis and antibiotics. Inexplicably, it took nearly another 150 years before the use of leeches in this context was revived.

  16. OCCURRENCE OF TWO LEECH SPECIES (ANNELIDA: HIRUDINEA) ON FISHES IN THE KENTUCKY RIVER

    EPA Science Inventory

    Little is known specifically on the feeding relationships between parasitic leeches and fish in North America. During an electrofishing survey conducted on the main stem of the Kentucky River in the summer of 2000, the presence of leeches was documented on six species of fish. ...

  17. Detection and selective avoidance of near ultraviolet radiation by an aquatic annelid: the medicinal leech.

    PubMed

    Jellies, John

    2014-03-15

    Medicinal leeches are aquatic predators that inhabit surface waters during daylight and also leave the water where they might be exposed to less screened light. Whereas the leech visual system has been shown to respond to visible light, leeches in the genus Hirudo do not appear to be as negatively phototactic as one might expect in order to avoid potential ultraviolet radiation (UVR)-induced damage. I used high intensity light emitting diodes to test the hypothesis that leeches could detect and specifically avoid near UVR (395-405 nm). Groups of unfed juvenile leeches exhibited a robust negative phototaxis to UVR, but had no behavioral response to blue or red and only a slight negative phototaxis to green and white light. Individual leeches also exhibited a vigorous negative phototaxis to UVR; responding in 100% of trials compared with modest negative responses to visible light (responding in ~8% of the trials). The responses in fed and unfed leeches were comparable for UVR stimuli. The responses depended upon the stimulus site: leeches shortened away from UV light to the head, and extended away from UV light to the tail. Electrophysiological nerve recordings showed that the cephalic eyes responded vigorously to UVR. Additionally, individual leech photoreceptors also showed strong responses to UVR, and a higher-order neuron associated with shortening and rapid behavioral responses, the S-cell, was activated by UVR, on both the head and tail. These results demonstrate that the leech can detect UVR and is able to discriminate behaviorally between UVR and visible light.

  18. Detection and selective avoidance of near ultraviolet radiation by an aquatic annelid: the medicinal leech

    PubMed Central

    Jellies, John

    2014-01-01

    Medicinal leeches are aquatic predators that inhabit surface waters during daylight and also leave the water where they might be exposed to less screened light. Whereas the leech visual system has been shown to respond to visible light, leeches in the genus Hirudo do not appear to be as negatively phototactic as one might expect in order to avoid potential ultraviolet radiation (UVR)-induced damage. I used high intensity light emitting diodes to test the hypothesis that leeches could detect and specifically avoid near UVR (395–405 nm). Groups of unfed juvenile leeches exhibited a robust negative phototaxis to UVR, but had no behavioral response to blue or red and only a slight negative phototaxis to green and white light. Individual leeches also exhibited a vigorous negative phototaxis to UVR; responding in 100% of trials compared with modest negative responses to visible light (responding in ~8% of the trials). The responses in fed and unfed leeches were comparable for UVR stimuli. The responses depended upon the stimulus site: leeches shortened away from UV light to the head, and extended away from UV light to the tail. Electrophysiological nerve recordings showed that the cephalic eyes responded vigorously to UVR. Additionally, individual leech photoreceptors also showed strong responses to UVR, and a higher-order neuron associated with shortening and rapid behavioral responses, the S-cell, was activated by UVR, on both the head and tail. These results demonstrate that the leech can detect UVR and is able to discriminate behaviorally between UVR and visible light. PMID:24265432

  19. Central nervous system regeneration: from leech to opossum.

    PubMed

    Mladinic, M; Muller, K J; Nicholls, J G

    2009-06-15

    A major problem of neurobiology concerns the failure of injured mammalian spinal cord to repair itself. This review summarizes work done on two preparations in which regeneration can occur: the central nervous system of an invertebrate, the leech, and the spinal cord of an immature mammal, the opossum. The aim is to understand cellular and molecular mechanisms that promote and prevent regeneration. In the leech, an individual axon regrows successfully to re-establish connections with its synaptic target, while avoiding other neurons. Functions that were lost are thereby restored. Moreover, pairs of identified neurons become re-connected with appropriate synapses in culture. It has been shown that microglial cells and nitric oxide play key roles in leech CNS regeneration. In the opossum, the neonatal brain and spinal cord are so tiny that they survive well in culture. Fibres grow across spinal cord lesions in neonatal animals and in vitro, but axon regeneration stops abruptly between postnatal days 9 and 12. A comprehensive search has been made in spinal cords that can and cannot regenerate to identify genes and establish their locations. At 9 days, growth-promoting genes, their receptors and key transcription molecules are up-regulated. By contrast at 12 days, growth-inhibitory molecules associated with myelin are prominent. The complete sequence of the opossum genome and new methods for transfecting genes offer ways to determine which molecules promote and which inhibit spinal cord regeneration. These results lead to questions about how basic research on mechanisms of regeneration could be 'translated' into effective therapies for patients with spinal cord injuries.

  20. Central nervous system regeneration: from leech to opossum

    PubMed Central

    Mladinic, M; Muller, K J; Nicholls, J G

    2009-01-01

    A major problem of neurobiology concerns the failure of injured mammalian spinal cord to repair itself. This review summarizes work done on two preparations in which regeneration can occur: the central nervous system of an invertebrate, the leech, and the spinal cord of an immature mammal, the opossum. The aim is to understand cellular and molecular mechanisms that promote and prevent regeneration. In the leech, an individual axon regrows successfully to re-establish connections with its synaptic target, while avoiding other neurons. Functions that were lost are thereby restored. Moreover, pairs of identified neurons become re-connected with appropriate synapses in culture. It has been shown that microglial cells and nitric oxide play key roles in leech CNS regeneration. In the opossum, the neonatal brain and spinal cord are so tiny that they survive well in culture. Fibres grow across spinal cord lesions in neonatal animals and in vitro, but axon regeneration stops abruptly between postnatal days 9 and 12. A comprehensive search has been made in spinal cords that can and cannot regenerate to identify genes and establish their locations. At 9 days, growth-promoting genes, their receptors and key transcription molecules are up-regulated. By contrast at 12 days, growth-inhibitory molecules associated with myelin are prominent. The complete sequence of the opossum genome and new methods for transfecting genes offer ways to determine which molecules promote and which inhibit spinal cord regeneration. These results lead to questions about how basic research on mechanisms of regeneration could be ‘translated’ into effective therapies for patients with spinal cord injuries. PMID:19525562

  1. Control of epileptiform bursting in the leech heart interneuron

    NASA Astrophysics Data System (ADS)

    Barnett, William; Anquez, Martin; Harris, Torrey; Cymbalyuk, Gennady

    2009-11-01

    The network controlling heartbeat in the medicinal leech contains leech heart interneurons (HNs). We modeled them under specific pharmacological conditions. The Ca^2+ currents were blocked by Co^2+. The K^+ currents, apart from the non-inactivating current, IK2, were blocked by 4AP. The hyperpolarization-activated current, Ih, was blocked by Cs^+. Under these conditions, epileptiform bursting characterized by long interburst intervals (IBI) has been shown. We considered three distinct cases. Model 1 included IK2, Ih, and the fast Na^+ current, INa. Model 2 was characterized by INa, IK2, and the persistent Na^+ current, INaP. Model 3 consisted of INa, IK2, Ih, and INaP. We also investigated the bi-stability of bursting and silence as the leak conductance, gleak, was varied. We showed that in 1 and 3, model HNs demonstrated bi-stability of silence and bursting. We analyzed how IBI and burst duration are controlled by the manipulation of Ih and INaP. In 1, as V1/2 of Ih decreased, IBI grew towards infinity one over the square root of the parameter difference. In 2, we showed that as gNaP decreased from 6.156 nS to 6.155 nS, IBI grew in accordance with the one over square root law. The system underwent a saddle-node bifurcation just below 6.155 nS. Supported by NSF PHY-0750456.

  2. Host Matters: Medicinal Leech Digestive-Tract Symbionts and Their Pathogenic Potential

    PubMed Central

    Marden, Jeremiah N.; McClure, Emily A.; Beka, Lidia; Graf, Joerg

    2016-01-01

    Digestive-tract microbiota exert tremendous influence over host health. Host-symbiont model systems are studied to investigate how symbioses are initiated and maintained, as well as to identify host processes affected by resident microbiota. The medicinal leech, Hirudo verbana, is an excellent model to address such questions owing to a microbiome that is consistently dominated by two species, Aeromonas veronii and Mucinivorans hirudinis, both of which are cultivable and have sequenced genomes. This review outlines current knowledge about the dynamics of the H. verbana microbiome. We discuss in depth the factors required for A. veronii colonization and proliferation in the leech crop and summarize the current understanding of interactions between A. veronii and its annelid host. Lastly, we discuss leech usage in modern medicine and highlight how leech-therapy associated infections, often attributable to Aeromonas spp., are of growing clinical concern due in part to an increased prevalence of fluoroquinolone resistant strains. PMID:27790190

  3. STUDIES ON RARE AND POORLY KNOWN LEECHES (ANNELIDA: HIRUDINEA: GLOSSIPHONIIDAE) IN EASTERN NORTH AMERICA

    EPA Science Inventory

    Three taxa within the leech family Glossiphoniidae, Actinobdella inequiannulata, Placobdella hollensis, and Theromyzon spp., though widespread in eastern North America, remain poorly known with respect to their biology and systematics. All three taxa have been collected in New E...

  4. A new species of glossiphoniid leech from Rana pretiosa (Amphibia: Ranidae) in Oregon.

    PubMed

    Siddall, Mark E; Bowerman, Jay

    2006-08-01

    A new species of ectoparasitic glossiphoniid leech was found feeding on frogs in the Nature Center Pond and elsewhere in Deschutes County, Oregon. The new species of Placobdella resembles the southern alligator leech, Placobdella multilineata Moore, 1953, notwithstanding their vast geographic separation in North America. The new species is readily distinguished by possessing subdivided annuli, by its papillation and pigmentation patterns as well as by the arrangement of ovarian tissues. There is strong evidence of nocturnality and of the potential for parasitizing humans.

  5. First Isolation of a Giant Virus from Wild Hirudo medicinalis Leech: Mimiviridae isolation in Hirudo medicinalis

    PubMed Central

    Boughalmi, Mondher; Pagnier, Isabelle; Aherfi, Sarah; Colson, Philippe; Raoult, Didier; La Scola, Bernard

    2013-01-01

    Giant viruses and amoebae are common in freshwater, where they can coexist with other living multicellular organisms. We screened leeches from the species Hirudo medicinalis for giant viruses. We analyzed five H. medicinalis obtained from Tunisia (3) and France (2). The leeches were decontaminated and then dissected to remove internal parts for co-culture with Acanthamoeba polyphaga. The genomes of isolated viruses were sequenced on a 454 Roche instrument, and a comparative genomics analysis was performed. One Mimivirus was isolated and the strain was named Hirudovirus. The genome assembly generated two scaffolds, which were 1,155,382 and 25,660 base pairs in length. Functional annotations were identified for 47% of the genes, which corresponds to 466 proteins. The presence of Mimividae in the same ecological niche as wild Hirudo may explain the presence of the mimivirus in the digestive tract of the leech, and several studies have already shown that viruses can persist in the digestive tracts of leeches fed contaminated blood. As leeches can be used medically and Mimiviruses have the potential to be an infectious agent in humans, patients treated with leeches should be surveyed to investigate a possible connection. PMID:24287596

  6. New Records of Lake Baikal Leech Fauna: Species Diversity and Spatial Distribution in Chivyrkuy Gulf

    PubMed Central

    Kaygorodova, Irina A.; Pronin, Nikolay M.

    2013-01-01

    The study of several Lake Baikal leech collections offered us the possibility to determine species diversity in the Chivyrkuy Gulf, the biggest one in the lake. As a result, the first information on the Chivyrkuy Hirudinea fauna (Annelida, Clitellata) has been revealed. There are two orders and four families of leeches in the Chivyrkuy Gulf: order Rhynchobdellida (families Glossiphoniidae and Piscicolidae) and order Arhynchobdellida (families Erpobdellidae and Haemopidae). In total, 22 leech species and 2 subspecies belonging to 11 genera were identified. Of these, 4 taxa belong to the family Glossiphoniidae (G. concolor, A. hyalina, A. heteroclita f. papillosa, and A. heteroclita f. striata) recorded in Baikal for the first time. Representatives of 8 unidentified species (Glossophinia sp., Baicaloclepsis sp., Baicalobdella sp., Piscicola sp. 1, Piscicola sp. 2, Erpobdella sp. 1, Erpobdella sp. 2, and Erpobdella sp. 3) have been also recorded. The checklist gives a contemporary overview of the species composition of leech parasites, their hosts, and distribution within the Chivyrkuy Gulf. The analysis of spatial distribution has shown that the leech species diversity is correlated with the biological productivity of the bay. The most diverse community of leech species is detected in the eutrophic zone of the lake. PMID:23844382

  7. First isolation of a giant virus from wild Hirudo medicinalis leech: Mimiviridae isolation in Hirudo medicinalis.

    PubMed

    Boughalmi, Mondher; Pagnier, Isabelle; Aherfi, Sarah; Colson, Philippe; Raoult, Didier; La Scola, Bernard

    2013-11-27

    Giant viruses and amoebae are common in freshwater, where they can coexist with other living multicellular organisms. We screened leeches from the species Hirudo medicinalis for giant viruses. We analyzed five H. medicinalis obtained from Tunisia (3) and France (2). The leeches were decontaminated and then dissected to remove internal parts for co-culture with Acanthamoeba polyphaga. The genomes of isolated viruses were sequenced on a 454 Roche instrument, and a comparative genomics analysis was performed. One Mimivirus was isolated and the strain was named Hirudovirus. The genome assembly generated two scaffolds, which were 1,155,382 and 25,660 base pairs in length. Functional annotations were identified for 47% of the genes, which corresponds to 466 proteins. The presence of Mimividae in the same ecological niche as wild Hirudo may explain the presence of the mimivirus in the digestive tract of the leech, and several studies have already shown that viruses can persist in the digestive tracts of leeches fed contaminated blood. As leeches can be used medically and Mimiviruses have the potential to be an infectious agent in humans, patients treated with leeches should be surveyed to investigate a possible connection.

  8. Detection of Viral Hemorrhagic Septicemia virus (VHSV) from the leech Myzobdella lugubris Leidy, 1851.

    PubMed

    Faisal, Mohamed; Schulz, Carolyn A

    2009-09-28

    The leech Myzobdella lugubris is widespread in the Lake Erie Watershed, especially Lake St. Clair. However, its role in pathogen transmission is not fully understood. In this same watershed, several widespread fish mortalities associated with the Viral Hemorrhagic Septicemia virus (VHSV) were recorded. Viral Hemorrhagic Septicemia is an emerging disease in the Great Lakes Basin that is deadly to the fish population, yet little is known about its mode of transmission. To assess the potential role of M. lugubris in VHSV transmission, leeches were collected from Lake St. Clair and Lake Erie and pooled into samples of five. Cell culture and reverse transcriptase polymerase chain reaction (RT-PCR) were used to determine the presence of the virus and its identity. Results showed that 57 of the 91 pooled leech samples were positive by cell culture for VHSV and 66 of the 91 pooled leech samples were positive by RT-PCR for the VHSV. Two representative virus isolates were sequenced for further genetic confirmation and genotype classification. VHSV detected within M. lugubris was homologous to the Great Lakes strain of VHSV genotype IVb. This is the first record of the VHSV being detected from within a leech, specifically M. lugubris, and suggests the potential of M. lugubris being involved in VHSV transmission.

  9. Specialized brain regions and sensory inputs that control locomotion in leeches

    PubMed Central

    Mullins, Olivia J.; Brodfuehrer, Peter D.; Jusufović, Saša; Hackett, John T.; Friesen, W. Otto

    2011-01-01

    Locomotor systems are often controlled by specialized cephalic neurons and undergo modulation by sensory inputs. In many species, dedicated brain regions initiate and maintain behavior and set the duration and frequency of the locomotor episode. In the leech, removing the entire head brain enhances swimming, but the individual roles of its components, the supra- and subesophageal ganglia, in the control of locomotion are unknown. Here we describe the influence of these two structures and that of the tail brain on rhythmic swimming in isolated nerve cord preparations and in nearly-intact leeches suspended in an aqueous, “swim-enhancing” environment. We found that, in isolated preparations, swim episode duration and swim burst frequency are greatly increased when the supraesophageal ganglion is removed, but the subesophageal ganglion is intact. The prolonged swim durations observed with the anterior-most ganglion removed were abolished by removal of the tail ganglion. Experiments on the nearly intact leeches show that, in these preparations, the subesophageal ganglion acts to decrease cycle period but, unexpectedly, also decreases swim duration. These results suggest that the supraesophageal ganglion is the primary structure that constrains leech swimming; however, the control of swim duration in the leech is complex, especially in the intact animal. PMID:22037913

  10. Detection of Viral Hemorrhagic Septicemia virus (VHSV) from the leech Myzobdella lugubris Leidy, 1851

    PubMed Central

    Faisal, Mohamed; Schulz, Carolyn A

    2009-01-01

    The leech Myzobdella lugubris is widespread in the Lake Erie Watershed, especially Lake St. Clair. However, its role in pathogen transmission is not fully understood. In this same watershed, several widespread fish mortalities associated with the Viral Hemorrhagic Septicemia virus (VHSV) were recorded. Viral Hemorrhagic Septicemia is an emerging disease in the Great Lakes Basin that is deadly to the fish population, yet little is known about its mode of transmission. To assess the potential role of M. lugubris in VHSV transmission, leeches were collected from Lake St. Clair and Lake Erie and pooled into samples of five. Cell culture and reverse transcriptase polymerase chain reaction (RT-PCR) were used to determine the presence of the virus and its identity. Results showed that 57 of the 91 pooled leech samples were positive by cell culture for VHSV and 66 of the 91 pooled leech samples were positive by RT-PCR for the VHSV. Two representative virus isolates were sequenced for further genetic confirmation and genotype classification. VHSV detected within M. lugubris was homologous to the Great Lakes strain of VHSV genotype IVb. This is the first record of the VHSV being detected from within a leech, specifically M. lugubris, and suggests the potential of M. lugubris being involved in VHSV transmission. PMID:19785752

  11. Allium sativum L.: the anti-immature leech (Limnatis nilotica) activity compared to Niclosomide.

    PubMed

    Bahmani, Mahmoud; Abbasi, Javad; Mohsenzadegan, Ava; Sadeghian, Sirous; Ahangaran, Majid Gholami

    2013-03-01

    This study was carried out to determine the effects of methanolic extracts of Allium sativum L. on Limnatis nilotica compared with Niclosomide. In this experimental study in September 2010, a number of leeches (70 in total) from the southern area of Ilam province were prepared, and the effects of methanolic extract of A. sativum L. with Niclosomide as the control drug were compared and distilled water was evaluated as the placebo group which investigated L. nilotica using anti-leech assay. The average time of paralysis and death of L. nilotica for Niclosomide (1,250 mg/kg) and the methanol extract of A. sativum L. (600 μg/ml) were 6.22 ± 2.94 and 68.44 ± 28.39 min, respectively. Distilled water and garlic tablets at a dose of 400 mg were determined as the inert group. In this research, the attraction time of the leeches' death among different treatments is significant. In this study, it was determined that Niclosomide, with an intensity of 4+, and methanolic extracts of A. sativum L., with an intensity of 3+, have a good anti-leech effect and can be shown to be effective in cases of leech biting, while distilled water was negative.

  12. Bugs as drugs, part two: worms, leeches, scorpions, snails, ticks, centipedes, and spiders.

    PubMed

    Cherniack, E Paul

    2011-03-01

    In this second of a two-part series analyzing the evidence for the use of organisms as medicine, the use of a number of different "bugs" (worms, leeches, snails, ticks, centipedes, and spiders) is detailed. Several live organisms are used as treatments: leeches for plastic surgery and osteoarthritis and the helminths Trichuris suis and Necator americanus for inflammatory bowel disease. Leech saliva is the source of a number of anticoagulants, including the antithrombin agent hirudin and its synthetic analogues, which have been approved for human use. Predatory arthropods, such as certain species of snails, spiders, scorpions, centipedes, and ticks provide a trove of potential analgesic peptides in their venom. A synthetic analogue of a snail venom peptide, ziconotide, has been approved for human use and is used as an alternative to opioids in severe pain cases. Arthropods, such as ticks, have venom that contains anticoagulants and centipede venom has a protein that corrects abnormalities in lipid metabolism.

  13. 3H-GABA uptake selectively labels identifiable neurons in the leech central nervous system

    SciTech Connect

    Cline, H.T.

    1983-04-10

    Segmental ganglia of the leech ventral nerve cord synthesize the neurotransmitter gamma-aminobutyric acid (GABA) when incubated in the presence of the precursor glutamate, suggesting that there may be GABA-ergic neurons in the leech nerve cord. GABA-accumulating neurons of the two taxonomically distant leech species, Haementeria ghilianii and Hirudo medicinalis, have been labeled by taking advantage of their high-affinity uptake system for the neurotransmitter. Autoradiography of sectioned segmental ganglia previously exposed to 3H-GABA reveals a reproducible pattern of about thirty 3H-GABA-labeled neuronal cell bodies per ganglion. The majority of 3H-GABA-labeled neuronal cell bodies are bilaterally paired, although some apparently unpaired cell bodies also accumulate label. Neuronal processes were reproducibly labeled by GABA uptake and could be traced in the neuropil through commissures and fiber tracts into the segmental nerve roots and interganglionic connectives, respectively.

  14. Triassic leech cocoon from Antarctica contains fossil bell animal

    NASA Astrophysics Data System (ADS)

    Bomfleur, Benjamin; Kerp, Hans; Taylor, Thomas N.; Moestrup, Øjvind; Taylor, Edith L.

    2012-12-01

    Our understanding of the evolution of life on Earth is limited by the imperfection of the fossil record. One reason for this imperfect record is that organisms without hard parts, such as bones, shells, and wood, have a very low potential to enter the fossil record. Occasionally, however, exceptional fossil deposits that preserve soft-bodied organisms provide a rare glimpse of the true biodiversity during past periods of Earth history. We here present an extraordinary find of a fossil ciliate that is encased inside the wall layer of a more than 200 Ma leech cocoon from Antarctica. The microfossil consists of a helically contractile stalk that attaches to a main body with a peristomial feeding apparatus and a large C-shaped macronucleus. It agrees in every aspect with the living bell animals, such as Vorticella. Vorticellids and similar peritrichs are vital constituents of aquatic ecosystems worldwide, but so far have lacked any fossil record. This discovery offers a glimpse of ancient soft-bodied protozoan biotas, and also highlights the potential of clitellate cocoons as microscopic "conservation traps" comparable to amber.

  15. Channel modulation by tyrosine phosphorylation in an identified leech neuron.

    PubMed Central

    Aniksztejn, L; Catarsi, S; Drapeau, P

    1997-01-01

    1. We have examined the effects of tyrosine phosphorylation on a spontaneously active cation channel that also participates in the modulation of pressure-sensitive (P) neurons in the leech. Cation channel activity in cell-attached or isolated, inside-out membrane patches from P cells in culture was monitored before and after treatments that altered the level of tyrosine phosphorylation. 2. In cell-attached recordings from intact P cells, bath application of genistein, an inhibitor of tyrosine kinases, resulted in a 6.6 +/- 2.6-fold increase in channel activity with no change in the mean open time or amplitude. Daidzein, an inactive form of genistein, was without effect. Addition of pervanadate, a membrane-permeant inhibitor of tyrosine phosphatases, had no effect on its own and blocked the effect of subsequent addition of genistein. 3. In inside-out P cell membrane patch recordings, exposure to a catalytically active fragment of a tyrosine phosphatase resulted in a 10.3 +/- 3.6-fold increase in channel activity with no change in the mean open time or amplitude. Orthovanadate had no effect on channel activity and, when added with the phosphatase, prevented the increase in activity. 4. Our results demonstrate that the basal activity of cation channels is increased by tyrosine dephosphorylation, suggesting a constitutive modulation of channel activity under resting conditions. PMID:9023773

  16. Triassic leech cocoon from Antarctica contains fossil bell animal.

    PubMed

    Bomfleur, Benjamin; Kerp, Hans; Taylor, Thomas N; Moestrup, Øjvind; Taylor, Edith L

    2012-12-18

    Our understanding of the evolution of life on Earth is limited by the imperfection of the fossil record. One reason for this imperfect record is that organisms without hard parts, such as bones, shells, and wood, have a very low potential to enter the fossil record. Occasionally, however, exceptional fossil deposits that preserve soft-bodied organisms provide a rare glimpse of the true biodiversity during past periods of Earth history. We here present an extraordinary find of a fossil ciliate that is encased inside the wall layer of a more than 200 Ma leech cocoon from Antarctica. The microfossil consists of a helically contractile stalk that attaches to a main body with a peristomial feeding apparatus and a large C-shaped macronucleus. It agrees in every aspect with the living bell animals, such as Vorticella. Vorticellids and similar peritrichs are vital constituents of aquatic ecosystems worldwide, but so far have lacked any fossil record. This discovery offers a glimpse of ancient soft-bodied protozoan biotas, and also highlights the potential of clitellate cocoons as microscopic "conservation traps" comparable to amber.

  17. Triassic leech cocoon from Antarctica contains fossil bell animal

    PubMed Central

    Bomfleur, Benjamin; Kerp, Hans; Taylor, Thomas N.; Moestrup, Øjvind; Taylor, Edith L.

    2012-01-01

    Our understanding of the evolution of life on Earth is limited by the imperfection of the fossil record. One reason for this imperfect record is that organisms without hard parts, such as bones, shells, and wood, have a very low potential to enter the fossil record. Occasionally, however, exceptional fossil deposits that preserve soft-bodied organisms provide a rare glimpse of the true biodiversity during past periods of Earth history. We here present an extraordinary find of a fossil ciliate that is encased inside the wall layer of a more than 200 Ma leech cocoon from Antarctica. The microfossil consists of a helically contractile stalk that attaches to a main body with a peristomial feeding apparatus and a large C-shaped macronucleus. It agrees in every aspect with the living bell animals, such as Vorticella. Vorticellids and similar peritrichs are vital constituents of aquatic ecosystems worldwide, but so far have lacked any fossil record. This discovery offers a glimpse of ancient soft-bodied protozoan biotas, and also highlights the potential of clitellate cocoons as microscopic “conservation traps” comparable to amber. PMID:23213234

  18. Sibling competition in a brood-tending leech

    PubMed Central

    Burd, Martin; Govedich, Fredric R; Bateson, Laura

    2006-01-01

    Conflict among siblings over parental investment, particularly over parental feeding, is a feature of family life in many kinds of animals. In some bird species, the size of prey items provided to juveniles has been implicated as a cause of aggressive competition among sibling chicks, because prey size determines whether dominance allows monopolization of parental offerings. Our experiment was meant to test the generality of this factor in creating intrafamilial conflict. We investigated sibling competition in relation to prey size using the carnivorous, brood-tending leech Helobdella papillornata. We equalized the total amount of food available to H. papillornata broods, but varied the size of individual prey items. Competition, measured by disparity in body size at independence, was more intense in broods provisioned with small items than in broods receiving large items, but similar between broods receiving large items and broods fed ad libitum. These patterns suggest that the intensity of conflict did not depend only on the total food amount, but was enhanced by small prey size. Our results indicate that conflict over the provision of parental resources to offspring can have a similar basis across very dissimilar organisms. PMID:16959636

  19. Excitotoxicity of lathyrus sativus neurotoxin in leech retzius neurons.

    PubMed

    Cemerikic, D; Nedeljkov, V; Lopicic, S; Dragovic, S; Beleslin, B

    2001-01-01

    The effects of Lathyrus sativus neurotoxin were studied on the cell membrane potential and cellular cation composition in Retzius nerve cells of the leech Haemopis sanguisuga, with ion-selective microelectrodes using liquid ion-exchangers. Bath application of 10(-4) mol/l Lathyrus sativus neurotoxin for 3 min depolarized the cell membrane potential and decreased the input resistance of directly polarized membrane in Retzius neurons. At the same time the cellular Na+ activity increased and cellular K+ activity decreased with slow but complete recovery, while the intracellular Ca2+ concentration was not changed. Na+-free Ringer solutions inhibited the depolarizing effect of the neurotoxin on the cell membrane potential. Zero-Ca2+ Ringer solution or Ni2+-Ringer solution had no influence on the depolarizing effect of the neurotoxin on the cell membrane potential. It is obvious that the increase in membrane conductance and depolarization of the cell membrane potential are due to an influx of Na+ into the cell accompanied by an efflux of K+ from the cell.

  20. Microsurgical replantation and postoperative leech treatment of a large severed nasal segment.

    PubMed

    Stemann Andersen, Peter; Elberg, Jens Jørgen

    2012-12-01

    The survival of a microsurgically replanted segment of nose in a 41-year-old woman was facilitated by the assistance of the medicinal leech Hirudo medicinalis. An arterial microanastomosis was made to a severed partial segment of nose with no possibility of recreating a venous anastomosis. The resulting venous congestion was treated with nine days of treatment with a medical leech until venous neovascularisation had been achieved. At follow-up six months after discharge there was a well-heeled nasal segment and a satisfying functional - as well as cosmetic - result.

  1. Medicinal Leech Therapy for Glans Penis Congestion After Primary Bladder Exstrophy-Epispadias Repair in an Infant: A Case Report.

    PubMed

    Wagenheim, Gavin N; Au, Jason; Gargollo, Patricio C

    2016-01-01

    Many postoperative complications have been reported after repair of classic bladder exstrophy. We present a case of medicinal leech therapy for glans penis congestion following exstrophy repair in an infant. A 2-week-old male with classic bladder exstrophy underwent complete primary repair. On postoperative day 1, he developed rapidly worsening glans penis venous congestion. Medicinal leech therapy was instituted with antibiotics and blood transfusions to maintain a hematocrit >30%. After 24 hours, venous congestion improved and therapy was discontinued. The patient's remaining hospital course was uncomplicated. Medicinal leeches are an effective therapy to relieve glans penis venous congestion.

  2. Free Flap Salvage after Recurrent Venous Thrombosis by Means of Large-Scale Treatment with Medical Leeches

    PubMed Central

    Fujiki, Masahide; Arikawa, Masaki; Kagaya, Yu; Miyamoto, Shimpei

    2016-01-01

    Summary: An anterolateral thigh flap was salvaged using 110 medical leeches in the absence of an available vein for reanastomosis. After surgical construction of the flap for full-thickness thoracic wall reconstruction, the patient developed complete venous occlusion. Specifically, the anastomotic vein developed complete occlusion, and the internal jugular vein had a thrombus. In addition, because the lung was posterior to the flap, the angiogenic area of the flap was very small. When the medical leeches were first applied, the flap showed prominent venous congestion. However, the congestion began to resolve by day 6 of leech use, leading to complete survival of the flap. PMID:28293509

  3. Experimental infection of yellow stingrays Urobatis jamaicensis with the marine leech Branchellion torpedinis.

    PubMed

    Marancik, David P; Dove, Alistair D; Camus, Alvin C

    2012-10-10

    Infestations of elasmobranchs by the marine leech Branchellion torpedinis can be problematic in aquaria and negatively affect host health. To better characterize the extent and pathogenesis of disease, 12 yellow stingrays Urobatis jamaicensis were infected with 1 or 3 leeches for 14 d. Leeches were associated with anorexia, extensive cutaneous ulceration, decreased host packed cell volume (PCV) and serum total solids (TS), and mortality in 3 rays. Average decrease in host PCV positively correlated with ulcer size and parasite:host ratio. Average decrease in host serum TS positively correlated with parasite:host ratio. Blood chemistry and total white blood cell counts revealed no significant trends. Additional necropsy findings included gill and splenic pallor, pericardial edema, perirenal edema, and decreased hepatocellular lipid deposits. Microscopic evaluation of leeches demonstrated host erythrocytes and proteinaceous fluid within parasite intestines, confirming active blood feeding. Results indicate B. torpedinis has the potential to cause significant disease in elasmobranchs, including death in as few as 5 d, and identifies ulcer size and parasite:host ratio as risk factors for disease. Elucidation of this host-parasite interaction helps characterize host response to parasites and facilitate care of parasitized elasmobranchs in aquarium and wild settings.

  4. High contrast imaging at the LBT: the LEECH exoplanet imaging survey

    NASA Astrophysics Data System (ADS)

    Skemer, Andrew J.; Hinz, Philip; Esposito, Simone; Skrutskie, Michael F.; Defrère, Denis; Bailey, Vanessa; Leisenring, Jarron; Apai, Daniel; Biller, Beth; Bonnefoy, Mickaël.; Brandner, Wolfgang; Buenzli, Esther; Close, Laird; Crepp, Justin; De Rosa, Robert J.; Desidera, Silvano; Eisner, Josh; Fortney, Jonathan; Henning, Thomas; Hofmann, Karl-Heinz; Kopytova, Taisiya; Maire, Anne-Lise; Males, Jared R.; Millan-Gabet, Rafael; Morzinski, Katie; Oza, Apurva; Patience, Jenny; Rajan, Abhijith; Rieke, George; Schertl, Dieter; Schlieder, Joshua; Su, Kate; Vaz, Amali; Ward-Duong, Kimberly; Weigelt, Gerd; Woodward, Charles E.; Zimmerman, Neil

    2014-07-01

    In Spring 2013, the LEECH (LBTI Exozodi Exoplanet Common Hunt) survey began its ~130-night campaign from the Large Binocular Telescope (LBT) atop Mt Graham, Arizona. This survey benefits from the many technological achievements of the LBT, including two 8.4-meter mirrors on a single fixed mount, dual adaptive secondary mirrors for high Strehl performance, and a cold beam combiner to dramatically reduce the telescope's overall background emissivity. LEECH neatly complements other high-contrast planet imaging efforts by observing stars at L' (3.8 μm), as opposed to the shorter wavelength near-infrared bands (1-2.4 μm) of other surveys. This portion of the spectrum offers deep mass sensitivity, especially around nearby adolescent (~0.1-1 Gyr) stars. LEECH's contrast is competitive with other extreme adaptive optics systems, while providing an alternative survey strategy. Additionally, LEECH is characterizing known exoplanetary systems with observations from 3-5μm in preparation for JWST.

  5. Avulsion of the auricle in an anticoagulated patient: is leeching contraindicated? A review and a case.

    PubMed

    Mommsen, Jens; Rodríguez-Fernández, Javier; Mateos-Micas, Mario; Vázquez-Bouso, Olga; Gumbao-Grau, Victor; Forteza-Gonzalez, Gabriel

    2011-06-01

    Amputation of the auricle is a periodic occurrence leading to disfigurement if not treated properly. Venous stasis is a common complication in reattachments and requires decongestant and anticoagulant treatment. Today, leech therapy is the treatment of choice. Common problems are that it is not available everywhere and that it is usually contraindicated in anticoagulated patients. The peculiarities of leech therapy and the various aspects of surgical management are reviewed. A case of a partial amputation of the auricle in a patient under concomitant anticoagulation therapy with warfarin is presented. The amputated part was reattached in another hospital without microvascular anastomosis. The patient presented to our department with early signs of venous congestion. Leech therapy was started 35 hours after trauma, and the patient continued his anticoagulation therapy. With this treatment, 90% of the amputated part was rescued. The anticoagulation therapy of the patient may have played an important role in the first hours after reattachment, preventing capillary thrombosis and in consequence facilitating the minimal oxygenation necessary. The claim that anticoagulation therapy is a contraindication to leeching should be questioned in cases of reattachments in well-controllable locations without arterial anastomosis.

  6. Avulsion of the Auricle in an Anticoagulated Patient: Is Leeching Contraindicated? A Review and a Case

    PubMed Central

    Mommsen, Jens; Rodríguez-Fernández, Javier; Mateos-Micas, Mario; Vázquez-Bouso, Olga; Gumbao-Grau, Victor; Forteza-Gonzalez, Gabriel

    2011-01-01

    Amputation of the auricle is a periodic occurrence leading to disfigurement if not treated properly. Venous stasis is a common complication in reattachments and requires decongestant and anticoagulant treatment. Today, leech therapy is the treatment of choice. Common problems are that it is not available everywhere and that it is usually contraindicated in anticoagulated patients. The peculiarities of leech therapy and the various aspects of surgical management are reviewed. A case of a partial amputation of the auricle in a patient under concomitant anticoagulation therapy with warfarin is presented. The amputated part was reattached in another hospital without microvascular anastomosis. The patient presented to our department with early signs of venous congestion. Leech therapy was started 35 hours after trauma, and the patient continued his anticoagulation therapy. With this treatment, 90% of the amputated part was rescued. The anticoagulation therapy of the patient may have played an important role in the first hours after reattachment, preventing capillary thrombosis and in consequence facilitating the minimal oxygenation necessary. The claim that anticoagulation therapy is a contraindication to leeching should be questioned in cases of reattachments in well-controllable locations without arterial anastomosis. PMID:22655116

  7. The Physiology and Mechanics of Undulatory Swimming: A Student Laboratory Exercise Using Medicinal Leeches

    ERIC Educational Resources Information Center

    Ellerby, David J.

    2009-01-01

    The medicinal leech is a useful animal model for investigating undulatory swimming in the classroom. Unlike many swimming organisms, its swimming performance can be quantified without specialized equipment. A large blood meal alters swimming behavior in a way that can be used to generate a discussion of the hydrodynamics of swimming, muscle…

  8. LIFE HISTORY AND DISTRIBUTION OF THE LEECH OLIGOBDELLA BIANNULATA (MOORE, 1900) (EUHIRUDINEA: GLOSSIPHONNIDAE)

    EPA Science Inventory

    Oligobdella biannulata (Moore, 1900) is a rare, endemic leech species originally described from a mountain stream near Blowing Rock, North Carolina. Specimens of O. biannulata were collected seasonally from Fall 1999, to Summer 2002, with new county records in North Carolina and ...

  9. Effects of 5-hydroxytryptamine on the dorsal muscle of the leech (hirudo medicinalis)

    PubMed Central

    Schain, R. J.

    1961-01-01

    5-Hydroxytryptamine has an inhibiting effect on the leech muscle. It reduces the contractions produced by acetylcholine or nicotine and accelerates the relaxation of the muscle when these substances are washed out. This acceleration of relaxation allows a more rapid assay of acetylcholine in this preparation. PMID:13747232

  10. ERPOBDELLA LAHONTANA (ANNELIDA: HIRUDINEA: ARHYNCHOBDELLIDA: ERPOBDELLIDAE), A NEW SPECIES OF FRESHWATER LEECH FROM NORTH AMERICA

    EPA Science Inventory

    New species of a leech, Erpobdella lahontana, is described from the Lahontan Basin in California and Nevada of the western United States. This species has four pairs of eyes, the preatrial loops of male paired ducts extend to ganglion XI, and the male and female gonopores are loc...

  11. Infections following the application of leeches: two case reports and review of the literature

    PubMed Central

    2012-01-01

    Introduction Since the 1980s, leeches have been ingeniously used in the management of venous flap congestion. The presence of anticoagulative substances in their saliva improves the blood drainage. Their digestive tract contains several bacterial species, the main ones being Aeromonas hydrophila and Aeromonas veronii biovar sobria, which contribute to the digestion of ingested blood. These bacteria can be the cause of infections. Case presentation We report two cases of septicemia related to Aeromonas veronii biovar sobria that presented after leeches had been applied to congested transverse rectus abdominis myocutaneous flaps for delayed mammary reconstructions. Patient number 1 was a 55-year-old Caucasian woman who underwent a delayed breast reconstruction procedure. On the sixth postoperative day she showed a clinical presentation of septicemia. Aeromonas veronii biovar sobria was identified in the patient’s skin and blood bacteriological samples. Her fever ceased after 4 days of antibiotic treatment. Patient number 2 was a 56-year-old Caucasian woman who underwent a delayed breast reconstruction procedure. On the seventh postoperative day we noticed that she showed a clinical presentation of septicemia. Aeromonas veronii biovar sobria was identified in the patient’s blood cultures and local bacteriological samples. An antibiogram showed resistance to amoxicillin/clavulanic acid. Her fever ceased on the eleventh postoperative day after 4 days of antibiotic treatment. Conclusion The rate of infection after application of leeches is not negligible. The concentration of Aeromonas inside the digestive tracts of leeches largely decreases when the patient is under antibiotic therapy. These germs are sensitive to third-generation cephalosporins and fluoroquinolones and resistant to amoxicillin/clavulanic acid. We recommend preventive treatment based on classical measures of asepsis and on oral antibioprophylaxy with a fluoroquinolone during the whole period of

  12. BIOLOGY AND OCCURRENCE OF THE LEECH, ACTINOBDELLA INEQUIANNULATA (ANNELIDA: HIRUDINEA: GLOSSIPHONIIDAE) PARASITIC ON TWO SPECIES OF SUCKERS

    EPA Science Inventory

    Actinobdella inequiannulata was found on the white sucker, Catostomus commersoni, and less frequently on the longnose sucker, Catostomus catostomus, in Algonquin Provincial Park, Ontario, Canada. This study established the presence of only one species of leech, Actinobdela inequ...

  13. A new leech species (Hirudinida: Erpobdellidae: Erpobdella) from a cave in the West Azerbaijan province of Iran.

    PubMed

    Cichocka, Joanna M; Bielecki, Aleksander; Kur, Jarosław; Pikuła, Dorota; Kilikowska, Adrianna; Biernacka, Beata

    2015-09-09

    Erpobdella borisi n. sp. is a predatory leech inhabiting cave waters in Iran. Probably, it is either a troglobiont or troglophile. The leech has no eyes, and the complete mid-body somite is divided unequally into five annuli. Results of phylogenetic analysis based on morphological characters and COI gene sequence indicate the species to be closely related to Erpobdella japonica, E. octoculata and E. testacea.

  14. Model of intersegmental coordination in the leech heartbeat neuronal network.

    PubMed

    Hill, Andrew A V; Masino, Mark A; Calabrese, Ronald L

    2002-03-01

    We have created a computational model of the timing network that paces the heartbeat of the medicinal leech, Hirudo medicinalis. The rhythmic activity of this network originates from two segmental oscillators located in the third and fourth midbody ganglia. In the intact nerve cord, these segmental oscillators are mutually entrained to the same cycle period. Although experiments have shown that the segmental oscillators are coupled by inhibitory coordinating interneurons, the underlying mechanisms of intersegmental coordination have not yet been elucidated. To help understand this coordination, we have created a simple computational model with two variants: symmetric and asymmetric. In the symmetric model, neurons within each segmental oscillator called oscillator interneurons, inhibit the coordinating interneurons. In contrast, in the asymmetric model only the oscillator interneurons of one segmental oscillator inhibit the coordinating interneurons. In the symmetric model, when two segmental oscillators with different inherent periods are coupled, the faster one leads in phase, and the period of the coupled system is equal to the period of the faster oscillator. This behavior arises because, during each oscillation cycle, the oscillator interneurons of the faster segmental oscillator begin to burst before those of the slower oscillator, thereby terminating spike activity in the coordinating interneurons. Thus there is a brief period of time in each cycle when the oscillator interneurons of the slower segmental oscillator are relieved of inhibition from the coordinating interneurons. This "removal of synaptic inhibition" allows, within certain limits, the slower segmental oscillator to be sped to the period of the faster one. Thus the symmetric model demonstrates a plausible biophysical mechanism by which one segmental oscillator can entrain the other. In general the asymmetric model, in which only one segmental oscillator has the ability to inhibit the

  15. Earthquake relocation near the Leech River Fault, southern Vancouver Island

    NASA Astrophysics Data System (ADS)

    Li, G.; Liu, Y.; Regalla, C.

    2015-12-01

    The Leech River Fault (LRF), a northeast dipping thrust, extends across the southern tip of Vancouver Island in Southwest British Columbia, where local tectonic regime is dominated by the subduction of the Juan de Fuca plate beneath the North American plate at the present rate of 40-50 mm/year. British Columbia geologic map (Geoscience Map 2009-1A) shows that this area also consists of many crosscutting minor faults in addition to the San Juan Fault north of the LRF. To investigate the seismic evidence of the subsurface structures of these minor faults and of possible hidden active structures in this area, precise earthquake locations are required. In this study, we relocate 941 earthquakes reported by Canadian National Seismograph Network (CNSN) catalog from 2000 to 2015 within a 100km x 55km study area surrounding the LRF. We use HypoDD [Waldhauser, F., 2001] double-difference relocation method by combining P/S phase arrivals provided by the CNSN at 169 stations and waveform data with correlation coefficient values greater than 0.7 at 50 common stations and event separation less than 10km. A total of 900 out of the 931 events satisfy the above relocation criteria. Velocity model used is a 1-D model extracted from the Ramachandran et al. (2005) model. Average relative location errors estimated by the bootstrap method are 546.5m (horizontal) and 1128.6m (in depth). Absolute errors reported by SVD method for individual clusters are ~100m in both dimensions. We select 5 clusters visually according to their epicenters (see figure). Cluster 1 is parallel to the LRF and a thrust FID #60. Clusters 2 and 3 are bounded by two faults: FID #75, a northeast dipping thrust marking the southwestern boundary of the Wrangellia terrane, and FID #2 marking the northern boundary. Clusters 4 and 5, to the northeast and northwest of Victoria respectively, however, do not represent the surface traces of any mapped faults. The depth profile of Cluster 5 depicts a hidden northeast

  16. Humoral response of captive zebra sharks Stegostoma fasciatum to salivary gland proteins of the leech Branchellion torpedinis.

    PubMed

    Marancik, David P; Leary, John H; Fast, Mark M; Flajnik, Martin F; Camus, Alvin C

    2012-10-01

    Parasitism by the marine leech Branchellion torpedinis is known to cause disease and mortality in captive elasmobranchs and is difficult to control when inadvertently introduced into public aquaria. Preliminary characterization of the salivary gland transcriptome of B. torpedinis has identified anticoagulants, proteases, and immunomodulators that may be secreted into host tissues to aid leech feeding. This retrospective study examined antigen-specific serum IgM responses in captive zebra sharks Stegostoma fasciatum to leech salivary gland extract. Antibody response was examined by ELISA and Western blot assays in 20 serum samples from six zebra sharks, with a 5 year history of leech infection, and 18 serum samples from 8 captive bred zebra sharks, with no history of leech exposure. ELISA demonstrated significantly higher serum IgM titers to salivary gland extract in exposed zebra sharks compared to the non-exposed population. No obvious trends in antibody titers were appreciated in exposed zebra sharks over a four-year period. One-dimensional and two-dimensional Western blot assays revealed IgM targeted specific salivary gland proteins within the 40, 55, 70 and 90 kD range. Antigenic proteins identified by liquid chromatography-tandem mass spectrometry and de novo peptide sequencing include a secreted disintegrin, metalloproteinase and thrombospondin motif containing protein (ADAMTS), tubulin, aldehyde dehydrogenase and two unknown proteins. Humoral immune responses to leech salivary gland proteins warrants further investigation as there may be options to exploit immune mechanisms to reduce parasite burdens in aquaria.

  17. Morphological and molecular characterization of a marine fish trypanosome from South Africa, including its development in a leech vector

    PubMed Central

    2014-01-01

    Background Trypanosomes are ubiquitous blood parasites of marine and freshwater fishes, typically transmitted by aquatic leeches. Phylogenetic studies have been dominated by examples derived from freshwater fishes, with few marine representatives. Furthermore, life cycle studies on marine fish trypanosomes have focused on those of the northern hemisphere. In this investigation, we have examined the life cycle and molecular taxonomy of a marine fish trypanosome from South Africa. Methods To locate trypanosome stages, leeches were removed from fishes captured on the west and south coasts of South Africa, and fish blood films and leech squashes were Giemsa-stained and screened; leeches were also examined histologically. To determine whether trypanosome stages in fishes and leeches were of the same genotype, DNA was extracted from Giemsa-stained fish blood films and leech squashes, and from fish whole blood. Fragments of the 18S rRNA gene were amplified by PCR using trypanosome-specific primers and sequenced. Resulting sequence data were compared with each other and with published trypanosome 18S rDNA sequences, and used for phylogenetic analysis. Results Trypanosomes were detected in blood films from fishes of the families Clinidae, Blenniidae and Gobiidae. The flagellates ranged in size and staining properties within the films and across fish hosts. In squashes and histological sections of adult and juvenile leeches, identified as Zeylanicobdella arugamensis, trypanosome developmental stages were predominantly slender epimastigotes. Sequence data showed that trypanosomes derived from fishes were identical, irrespective of whether they were small or large forms; sequences derived largely from leech epimastigotes were also identical to those obtained from fish trypanosomes. Fish and leech trypanosome sequences fell into a marine fish aquatic clade, and aligned most closely with two trypanosome sequences from marine fishes off Norway. Conclusions Combined morphological

  18. Annotated checklist of the leech species diversity in the Maloe More Strait of Lake Baikal, Russia

    PubMed Central

    Kaygorodova, Irina A.

    2015-01-01

    Abstract In this paper, the very first checklist of the freshwater leeches of Maloe More Strait, a special part of Lake Baikal, is presented. It includes 14 free-living and parasitic species, of which four species belong to endemic Baikal genera – two species from Baicalobdella and one species each from Baicaloclepsis and Codonobdella. The checklist highlights six potentially new morphological species recorded for the first time in the area. The exact systematic position is stated for all leech species. Each species from the list is provided with information on taxonomic synonymy, data on its geographic distribution, and ecological characteristics. New species records are additionally provided with brief morphological characteristics and photos of their external morphology. PMID:26798292

  19. New species of rhynchobdellid leech (Hirudinea: Glossiphoniidae): a parasite of turtles from Chiapas, Mexico.

    PubMed

    López-Jiménez, Serapio; Oceguera-Figueroa, Alejandro

    2009-12-01

    A new species of rhynchobdellid leech, Placobdella ringueleti n. sp., is described based on the examination of 25 specimens. Leeches were collected from body appendages of freshwater turtles (Kinosternon leucostomum, Dermatemys mawii, and Staurotypus triporcatus ) from Chiapas, Mexico. The new species resembles other members of the genus in the ocular morphology, bilobated ovaries, and presence of 1 pair of elongated mycetomes, but it is distinguished from them by the dorsal papillar pattern, by having a continuous longitudinal mid-dorsal stripe along the dorsal surface and papillae on the dorsal surface of the posterior sucker. Placobdella ringueleti represents the third species of the genus in Mexico. The type locality of the new species is part of the “El Ocote” Biosphere Reserve, Chiapas, Mexico.

  20. A mathematical model of motorneuron dynamics in the heartbeat of the leech

    NASA Astrophysics Data System (ADS)

    Buono, Pietro-Luciano; Palacios, A.

    2004-02-01

    The heartbeat of the medicinal leech is driven by direct contact between two arrays of motorneurons and two lateral blood vessels. At any given time, motorneurons exhibit one of two alternating states so that, on one side of the animal, the heart beats in a rear-to-front fashion (peristaltic), while on the other side the heart beats synchronously. Every 20 heartbeats, approximately, the two sides switch modes. It is known that the heartbeat rhythm is generated through burst of oscillatory activity produced by a central pattern generator (CPG) network of neurons. However, to the best of our knowledge, how the CPG activity is translated into peristaltic and synchronous rhythms in the motorneurons is yet unknown. In this work, we use symmetric systems of differential equations, accompanied with computational simulations, to investigate possible mechanisms for generating the motorneuron activity that characterizes the heartbeat of leeches and in particular the switching scenario.

  1. Functional morphology of suction discs and attachment performance of the Mediterranean medicinal leech (Hirudo verbana Carena)

    PubMed Central

    Eberhard, Laura; Gallenmüller, Friederike; Speck, Thomas

    2016-01-01

    Medicinal leeches use their suction discs for locomotion, adhesion to the host and, in the case of the anterior disc, also for blood ingestion. The biomechanics of their suction-based adhesion systems has been little understood until now. We investigated the functional morphology of the anterior and posterior suckers of Hirudo verbana by using light and scanning electron microscopy. Furthermore, we analysed the adhesion qualitatively and quantitatively by conducting behavioural and mechanical experiments. Our high-speed video analyses provide new insights into the attachment and detachment processes and we present a detailed description of the leech locomotion cycle. Pull-off force measurements of the anterior and posterior suction organs on seven different substrates under both aerial and water-submersed conditions reveal a significant influence of the surrounding medium, the substrate surface roughness and the tested organ on attachment forces and tenacities. PMID:27075001

  2. A new lineage of trypanosomes from Australian vertebrates and terrestrial bloodsucking leeches (Haemadipsidae).

    PubMed

    Hamilton, P B; Stevens, J R; Gidley, J; Holz, P; Gibson, W C

    2005-04-01

    Little is known about the trypanosomes of indigenous Australian vertebrates and their vectors. We surveyed a range of vertebrates and blood-feeding invertebrates for trypanosomes by parasitological and PCR-based methods using primers specific to the small subunit ribosomal RNA (SSU rRNA) gene of genus Trypanosoma. Trypanosome isolates were obtained in culture from two common wombats, one swamp wallaby and an Australian bird (Strepera sp.). By PCR, blood samples from three wombats, one brush-tailed wallaby, three platypuses and a frog were positive for trypanosome DNA. All the blood-sucking invertebrates screened were negative for trypanosomes both by microscopy and PCR, except for specimens of terrestrial leeches (Haemadipsidae). Of the latter, two Micobdella sp. specimens from Victoria and 18 Philaemon sp. specimens from Queensland were positive by PCR. Four Haemadipsa zeylanica specimens from Sri Lanka and three Leiobdella jawarerensis specimens from Papua New Guinea were also PCR positive for trypanosome DNA. We sequenced the SSU rRNA and glycosomal glyceraldehyde phosphate dehydrogenase (gGAPDH) genes in order to determine the phylogenetic positions of the new vertebrate and terrestrial leech trypanosomes. In trees based on these genes, Australian vertebrate trypanosomes fell in several distinct clades, for the most part being more closely related to trypanosomes outside Australia than to each other. Two previously undescribed wallaby trypanosomes fell in a clade with Trypanosoma theileri, the cosmopolitan bovid trypanosome, and Trypanosoma cyclops from a Malaysian primate. The terrestrial leech trypanosomes were closely related to the wallaby trypanosomes, T. cyclops and a trypanosome from an Australian frog. We suggest that haemadipsid leeches may be significant and widespread vectors of trypanosomes in Australia and Asia.

  3. Human recombinant RNASET2-induced inflammatory response and connective tissue remodeling in the medicinal leech.

    PubMed

    Baranzini, Nicolò; Pedrini, Edoardo; Girardello, Rossana; Tettamanti, Gianluca; de Eguileor, Magda; Taramelli, Roberto; Acquati, Francesco; Grimaldi, Annalisa

    2017-01-09

    In recent years, several studies have demonstrated that the RNASET2 gene is involved in the control of tumorigenicity in ovarian cancer cells. Furthermore, a role in establishing a functional cross-talk between cancer cells and the surrounding tumor microenvironment has been unveiled for this gene, based on its ability to act as an inducer of the innate immune response. Although several studies have reported on the molecular features of RNASET2, the details on the mechanisms by which this evolutionarily conserved ribonuclease regulates the immune system are still poorly defined. In the effort to clarify this aspect, we report here the effect of recombinant human RNASET2 injection and its role in regulating the innate immune response after bacterial challenge in an invertebrate model, the medicinal leech. We found that recombinant RNASET2 injection induces fibroplasias, connective tissue remodeling and the recruitment of numerous infiltrating cells expressing the specific macrophage markers CD68 and HmAIF1. The RNASET2-mediated chemotactic activity for macrophages has been further confirmed by using a consolidated experimental approach based on injection of the Matrigel biomatrice (MG) supplemented with recombinant RNASET2 in the leech body wall. One week after injection, a large number of CD68(+) and HmAIF-1(+) macrophages massively infiltrated MG sponges. Finally, in leeches challenged with lipopolysaccharides (LPS) or with the environmental bacteria pathogen Micrococcus nishinomiyaensis, numerous macrophages migrating to the site of inoculation expressed high levels of endogenous RNASET2. Taken together, these results suggest that RNASET2 is likely involved in the initial phase of the inflammatory response in leeches.

  4. Identification and quantification of nucleosides and nucleobases in Geosaurus and Leech by hydrophilic-interaction chromatography.

    PubMed

    Chen, Pei; Li, Wei; Li, Qin; Wang, Yinghua; Li, Zhenguo; Ni, Yefeng; Koike, Kazuo

    2011-09-15

    A simple hydrophilic-interaction chromatography (HILIC) method was developed for the identification and quantification of 14 nucleosides and nucleobases, namely cytosine, uracil, cytidine, guanine, hypoxanthine, xanthine, uridine, thymine, inosine, guanosine, thymidine, 2'-deoxyadenosine, 2'-deoxyinosine and 2'-deoxyuridine in two traditional Chinese medicines, Geosaurus and Leech. The separation was achieved on a TSKgel Amide-80 column (150 mm × 2.0 mm, 3.0 μm) with a mixture of acetonitrile and 10 mM aqueous ammonium acetate as the mobile phase at a flow rate of 0.2 mL/min. The temperature was set at 30°C and UV detection wavelength was set at 260 nm. All calibration curves showed good linearity (R(2)>0.9957) within the test ranges. The overall intra- and inter-day RSD ranged from 0.4 to 3.4% and from 0.7 to 3.3%, respectively. The LOD and LOQ were in the range of 0.07-30.49 ng/mL and 0.26-60.98 ng/mL, respectively. The repeatability of the method was in the range of 2.2-5.8% for Geosaurus and 1.4-5.5% for Leech. The recoveries of the samples were in the range of 91.4-100.9% for Geosaurus, and 91.9-99.3% for Leech. The established method was applied successfully for the analysis of nucleosides and nucleobases in 22 commercially available samples collected from different regions in China and Japan. Our data showed that HILIC had advantages as a useful tool for the study of the bioactive components in Geosaurus and Leech as well as their quality control, and could therefore be used for the determination of the analytes in pharmaceutical products and biological fluids.

  5. Land Leeches of the g. Haemadipsa (Haemadipsoidea: Haemadipsidae). I. Conditions Essential to Laboratory Colonization.

    DTIC Science & Technology

    1982-05-01

    segmented aquatic and terrestrial worms that belong to the Order Hirudinea, ( Annelida : Clitellata, Scriban and Autrum (2)) and are most closely related to the...WORTH, C.B. Description and discussion of the biting of an Indian land leech. ( Annelida : Hirudinea). J Bombay Nat Hist Soc 50:423-426, 1951 39...Haemadlpsidae and their Suborder, the Gnathobdellae (after 2-6,60). Phylum: Annelida Class: Clitellata Order: Ifirudinea (=Hirudiniformes) Suborder 1

  6. Multiple Changes in Peptide and Lipid Expression Associated with Regeneration in the Nervous System of the Medicinal Leech

    PubMed Central

    Meriaux, Céline; Arafah, Karim; Tasiemski, Aurélie; Wisztorski, Maxence; Bruand, Jocelyne; Boidin-Wichlacz, Céline; Desmons, Annie; Debois, Delphine; Laprévote, Olivier; Brunelle, Alain; Gaasterland, Terry; Macagno, Eduardo; Fournier, Isabelle; Salzet, Michel

    2011-01-01

    Background The adult medicinal leech central nervous system (CNS) is capable of regenerating specific synaptic circuitry after a mechanical lesion, displaying evidence of anatomical repair within a few days and functional recovery within a few weeks. In the present work, spatiotemporal changes in molecular distributions during this phenomenon are explored. Moreover, the hypothesis that neural regeneration involves some molecular factors initially employed during embryonic neural development is tested. Results Imaging mass spectrometry coupled to peptidomic and lipidomic methodologies allowed the selection of molecules whose spatiotemporal pattern of expression was of potential interest. The identification of peptides was aided by comparing MS/MS spectra obtained for the peptidome extracted from embryonic and adult tissues to leech transcriptome and genome databases. Through the parallel use of a classical lipidomic approach and secondary ion mass spectrometry, specific lipids, including cannabinoids, gangliosides and several other types, were detected in adult ganglia following mechanical damage to connected nerves. These observations motivated a search for possible effects of cannabinoids on neurite outgrowth. Exposing nervous tissues to Transient Receptor Potential Vanilloid (TRPV) receptor agonists resulted in enhanced neurite outgrowth from a cut nerve, while exposure to antagonists blocked such outgrowth. Conclusion The experiments on the regenerating adult leech CNS reported here provide direct evidence of increased titers of proteins that are thought to play important roles in early stages of neural development. Our data further suggest that endocannabinoids also play key roles in CNS regeneration, mediated through the activation of leech TRPVs, as a thorough search of leech genome databases failed to reveal any leech orthologs of the mammalian cannabinoid receptors but revealed putative TRPVs. In sum, our observations identify a number of lipids and

  7. Experimental Investigation on the Morphology and Adhesion Mechanism of Leech Posterior Suckers

    PubMed Central

    Dong, Wenhao

    2015-01-01

    The posterior sucker of a leech represents a fascinating natural system that allows the leech to adhere to different terrains and substrates. However, the mechanism of adhesion and desorption has not yet to be elucidated. In order to better understand how the adhesion is performed, we analyzed the surface structure, adsorption movements, the muscles’ distribution, physical characteristics, and the adsorption force of the leech posterior suckers by experimental investigation. Three conclusions can be drawn based on the obtained experimental results. First, the adhesion by the posterior sucker is wet adhesion, because the surface of the posterior sucker is smooth and the sealing can only be achieved on wet surfaces. Second, the deformation texture, consisting of soft collagen tissues and highly ductile epidermal tissues, plays a key role in adhering to rough surfaces. Finally, the adhesion and desorption is achieved by the synergetic operation of six muscle fibers working in different directions. Concrete saying, directional deformation of the collagen/epithermal interface driven by spatially-distributed muscle fibers facilitates the excretion of fluids in the sucker venter, thus allowing liquid sealing. Furthermore, we found that the adhesion strength is directly related to the size of the contact surface which is generated and affected by the sucker deformation. Such an underlying physical mechanism offers potential cues for developing innovative bio-inspired artificial adhesion systems. PMID:26536352

  8. Small bite, large impact-saliva and salivary molecules in the medicinal leech, Hirudo medicinalis

    NASA Astrophysics Data System (ADS)

    Hildebrandt, Jan-Peter; Lemke, Sarah

    2011-12-01

    Blood-sucking leeches have been used for medical purposes in humans for hundreds of years. Accordingly, one of the most prominent species has been named Hirudo medicinalis by Carl Linne in 1758. Feeding on vertebrate blood poses some serious problems to blood-sucking ectoparasites, as they have to penetrate the body surface of the host and to suppress the normal reactions of the host to such injuries (swelling, pain, inflammation) to remain undetected during the feeding period. Furthermore, the parasites have to take measures to inhibit the normal reactions in host tissues to blood vessel damage, namely hemostasis and blood coagulation (platelet aggregation and activation, activation of thrombin and formation of fibrin clots). During evolution, leeches have acquired the ability to control these processes in their hosts by transferring various bioactive substances to the host. These substances are supposedly produced in unicellular salivary gland cells and injected into the wound at the feeding site through tiny salivary ductule openings in the jaws that the leech uses to slice open the host body surface and to cut blood vessels in the depth of the wound. This review summarizes current knowledge about the salivary gland cells and the biological effects of individual saliva components as well as hints to the potential usefulness of some of these compounds for medical purposes.

  9. Reciprocal immune benefit based on complementary production of antibiotics by the leech Hirudo verbana and its gut symbiont Aeromonas veronii

    PubMed Central

    Tasiemski, Aurélie; Massol, François; Cuvillier-Hot, Virginie; Boidin-Wichlacz, Céline; Roger, Emmanuel; Rodet, Franck; Fournier, Isabelle; Thomas, Frédéric; Salzet, Michel

    2015-01-01

    The medicinal leech has established a long-term mutualistic association with Aeromonas veronii, a versatile bacterium which can also display free-living waterborne and fish- or human-pathogenic lifestyles. Here, we investigated the role of antibiotics in the dynamics of interaction between the leech and its gut symbiont Aeromonas. By combining biochemical and molecular approaches, we isolated and identified for the first time the antimicrobial peptides (AMPs) produced by the leech digestive tract and by its symbiont Aeromonas. Immunohistochemistry data and PCR analyses evidenced that leech AMP genes are induced in the gut epithelial cells when Aeromonas load is low (starved animals), while repressed when Aeromonas abundance is the highest (post blood feeding). The asynchronous production of AMPs by both partners suggests that these antibiotic substances (i) provide them with reciprocal protection against invasive bacteria and (ii) contribute to the unusual simplicity of the gut microflora of the leech. This immune benefit substantially reinforces the evidence of an evolutionarily stable association between H. verbana and A. veronii. Altogether these data may provide insights into the processes making the association with an Aeromonas species in the digestive tract either deleterious or beneficial. PMID:26635240

  10. Prevalence, Abundance, and Intensity of Implanted Spermatophores in the Leech Haementeria officinalis (Glossiphoniidae: Hirudinida) from Guanajuato, Mexico.

    PubMed

    Salas-Montiel, Ricardo; Phillips, Anna J; Contreras-Mirón, Samantha; Oceguera-Figueroa, Alejandro

    2017-02-01

    Fertilization through hypodermic implantation of spermatophores has been recorded in at least 4 groups of leeches: Glossiphoniidae, Piscicolidae, Ozobranchidae, and Erpobdelliformes. In Piscicola respirans (Piscicolidae), vector tissue responsible for sperm transfer from a specialized region of the body to the ovaries has led to the non-random attachment of spermatophores on the body surface of the recipient leech. It has been suggested that in glossiphoniid leeches, spermatophores are implanted in any part of the body surface of the recipient leech without a clear pattern or preference for region. In order to determine if the donor leech implants its spermatophores in a specific area of the conspecific recipient's body, we surveyed 81 specimens of Haementeria officinalis (Clitellata: Glossiphoniidae) from a wild population in Guanajuato, Mexico, and recorded the distribution of the spermatophores over the recipient's body surface. We describe for the first time a spermatophore of H. officinalis using scanning electron and light microscopy. Spermatophores were found attached dorsally between somites XVII and XXI 59.57% of the time, and the rest were found in other parts of the body, including on the ventral surface. The non-specific attachment for spermatophores does not support the presence of specialized tissue responsible for sperm transfer and instead attributes the placement of implantation to mechanical characteristics of the copulation process.

  11. Reciprocal immune benefit based on complementary production of antibiotics by the leech Hirudo verbana and its gut symbiont Aeromonas veronii.

    PubMed

    Tasiemski, Aurélie; Massol, François; Cuvillier-Hot, Virginie; Boidin-Wichlacz, Céline; Roger, Emmanuel; Rodet, Franck; Fournier, Isabelle; Thomas, Frédéric; Salzet, Michel

    2015-12-04

    The medicinal leech has established a long-term mutualistic association with Aeromonas veronii, a versatile bacterium which can also display free-living waterborne and fish- or human-pathogenic lifestyles. Here, we investigated the role of antibiotics in the dynamics of interaction between the leech and its gut symbiont Aeromonas. By combining biochemical and molecular approaches, we isolated and identified for the first time the antimicrobial peptides (AMPs) produced by the leech digestive tract and by its symbiont Aeromonas. Immunohistochemistry data and PCR analyses evidenced that leech AMP genes are induced in the gut epithelial cells when Aeromonas load is low (starved animals), while repressed when Aeromonas abundance is the highest (post blood feeding). The asynchronous production of AMPs by both partners suggests that these antibiotic substances (i) provide them with reciprocal protection against invasive bacteria and (ii) contribute to the unusual simplicity of the gut microflora of the leech. This immune benefit substantially reinforces the evidence of an evolutionarily stable association between H. verbana and A. veronii. Altogether these data may provide insights into the processes making the association with an Aeromonas species in the digestive tract either deleterious or beneficial.

  12. Historical Article: Hirudo medicinalis: ancient origins of, and trends in the use of medicinal leeches throughout history.

    PubMed

    Whitaker, I S; Rao, J; Izadi, D; Butler, P E

    2004-04-01

    Blood letting and the therapeutic use of Hirudo medicinalis date back to ancient Egypt and the beginning of civilisation. Their popularity has varied over the years, reaching such a peak in Europe between 1825 and 1850 that supplies were exhausted. Towards the end of the century they fell out of favour and, during this period, the leech, once used by the physicians of emperors and influential academic surgeons, became associated with lay therapists and quackery. Leeches have enjoyed a renaissance in reconstructive microsurgery during the last 15 years, having been used by maxillofacial [Br. J. Oral Maxillofac. Surg 41 (2003) 44] and other reconstructive surgeons to aid salvage of compromised microvascular free tissue transfers [Laryngoscope 108 (1998) 1129; Br. J. Plast. Surg. 34 (1984) 358], replanted digits [Int. J. Microsurg. 3 (1981) 265], ears [Ann. Plast. Surg. 43 (1999) 427], lips [Plast. Reconstr. Surg. 102 (1998) 358; J. Reconstr. Microsurg. 9 (1993) 327] and nasal tips [Br. J. Oral Maxillofac. Surg. 36 (1998) 462]. Peer-reviewed evidence suggests that the survival of compromised, venous-congested tissues is improved by early application of a leech [J. Reconstr. Microsurg. 12 (1996) 165; Arch. Otolaryngol. Head Neck Surg. 114 (1988) 1395; Br. J. Plast. Surg. 45 (1992) 235]. Leeches have also recently been used to treat a wide range of conditions, including periorbital haematomas [Br. J. Ophthalmol. 75 (1991) 755], severe macroglossia [Otolaryngol. Head Neck Surg. 125 (2001) 649; J. Laryngol. Otol. 109 (1995) 442] and purpura fulminans [Ann. Plast. Surg. 35 (1995) 300]. The first medicinal leech farm, Biopharm, was set up in Swansea in 1981 by Dr Roy Sawyer, and now supplies leeches to hospitals all over the world. In this paper, we summarise the history of treatment with Hirudo medicinalis from its origin to the present day, and take a brief look at the possible future of the annelid.

  13. Occurrence of the Leech, Pontobdella muricata Linnaeus, on Elasmobranch Species in the Northern and Central Adriatic Sea.

    PubMed

    Bolognini, Luca; Leoni, Simone; Polidori, Piero; Grati, Fabio; Scarcella, Giuseppe; Pellini, Giulio; Domenichetti, Filippo; Ferrà, Carmen; Fabi, Gianna

    2016-12-01

    This study provides a parasitological analysis of the elasmobranch species caught in the northern and central Adriatic Sea. Sixty-two marine leeches were recorded on 747 individuals of Raja clavata Linnaeus, 1758 (thornback ray), Myliobatis aquila Linnaeus, 1758 (common eagle ray), and Torpedo marmorata Risso, 1810 (marbled torpedo ray) caught in 56 hauls over a 5 yr period. All leeches were identified as Pontobdella muricata, which is a typical ectoparasite of benthic elasmobranchs. The prevalence of infection ranged from 7.11% on R. clavata to 12.00% on M. aquila. The intensity of infection, the preferential sites of attachment to the host, and the periodicity of infection were evaluated.

  14. Establishment of segment polarity in the ectoderm of the leech Helobdella

    NASA Technical Reports Server (NTRS)

    Seaver, E. C.; Shankland, M.

    2001-01-01

    The segmented ectoderm and mesoderm of the leech arise via a stereotyped cell lineage from embryonic stem cells called teloblasts. Each teloblast gives rise to a column of primary blast cell daughters, and the blast cells generate descendant clones that serve as the segmental repeats of their particular teloblast lineage. We have examined the mechanism by which the leech primary blast cell clones acquire segment polarity - i.e. a fixed sequence of positional values ordered along the anteroposterior axis of the segmental repeat. In the O and P teloblast lineages, the earliest divisions of the primary blast cell segregate anterior and posterior cell fates along the anteroposterior axis. Using a laser microbeam, we ablated single cells from both o and p blast cell clones at stages when the clone was two to four cells in length. The developmental fate of the remaining cells was characterized with rhodamine-dextran lineage tracer. Twelve different progeny cells were ablated, and in every case the ablation eliminated the normal descendants of the ablated cell while having little or no detectable effect on the developmental fate of the remaining cells. This included experiments in which we specifically ablated those blast cell progeny that are known to express the engrailed gene, or their lineal precursors. These findings confirm and extend a previous study by showing that the establishment of segment polarity in the leech ectoderm is largely independent of cell interactions conveyed along the anteroposterior axis. Both intercellular signaling and engrailed expression play an important role in the segment polarity specification of the Drosophila embryo, and our findings suggest that there may be little or no conservation of this developmental mechanism between those two organisms.

  15. Isolation of infectious hematopoietic necrosis virus from a leech (Piscicola salmositica) and a copepod (Salmincola sp.), ectoparasites of sockeye salmon Oncorhynchus nerka

    USGS Publications Warehouse

    Mulcahy, D.; Klaybor, D.; Batts, W.N.

    1990-01-01

    ectious hematopoietic necrosis (IHN) virus was isolated from freshwater leeches Piscicola salmositica and copepods Salmincola sp. removed from the gills of spawning sockeye salmon Oncorhynchus nerka. This is the first report of the isolation of IHN virus from an animal other than salmonid fishes. High levels of IHN virus were also found in leeches taken from the bottom gravel of the spawning area. The prevalence of IHN virus in samples of individual leeches was as high as 100 "/o and the virus was isolated from 95 % of pooled samples of copepods. The highest level of virus was 8.7 X lo5 pfu (plaque forming units) g-' in the copepod and 1.5 X 10"fu g-' in the leech. The level of virus in leeches removed from fish gills was sometimes higher than the level of virus in the gill tissue itself. Virus persisted for at least 16 d in leeches held in the laboratory without feeding. Transmission of IHN virus by leeches probably increases the infection rate of spawning sockeye salmon.

  16. iDNA from terrestrial haematophagous leeches as a wildlife surveying and monitoring tool - prospects, pitfalls and avenues to be developed.

    PubMed

    Schnell, Ida Bærholm; Sollmann, Rahel; Calvignac-Spencer, Sébastien; Siddall, Mark E; Yu, Douglas W; Wilting, Andreas; Gilbert, M Thomas P

    2015-01-01

    Invertebrate-derived DNA (iDNA) from terrestrial haematophagous leeches has recently been proposed as a powerful non-invasive tool with which to detect vertebrate species and thus to survey their populations. However, to date little attention has been given to whether and how this, or indeed any other iDNA-derived data, can be combined with state-of-the-art analytical tools to estimate wildlife abundances, population dynamics and distributions. In this review, we discuss the challenges that face the application of existing analytical methods such as site-occupancy and spatial capture-recapture (SCR) models to terrestrial leech iDNA, in particular, possible violations of key assumptions arising from factors intrinsic to invertebrate parasite biology. Specifically, we review the advantages and disadvantages of terrestrial leeches as a source of iDNA and summarize the utility of leeches for presence, occupancy, and spatial capture-recapture models. The main source of uncertainty that attends species detections derived from leech gut contents is attributable to uncertainty about the spatio-temporal sampling frame, since leeches retain host-blood for months and can move after feeding. Subsequently, we briefly address how the analytical challenges associated with leeches may apply to other sources of iDNA. Our review highlights that despite the considerable potential of leech (and indeed any) iDNA as a new survey tool, further pilot studies are needed to assess how analytical methods can overcome or not the potential biases and assumption violations of the new field of iDNA. Specifically we argue that studies to compare iDNA sampling with standard survey methods such as camera trapping, and those to improve our knowledge on leech (and other invertebrate parasite) physiology, taxonomy, and ecology will be of immense future value.

  17. Physiological, pharmacological and behavioral evidence for a TRPA1 channel that can elicit defensive responses in the medicinal leech.

    PubMed

    Summers, Torrie; Wang, Yanqing; Hanten, Brandon; Burrell, Brian D

    2015-10-01

    Transient receptor potential ankyrin subtype 1 (TRPA1) channels are chemosensitive to compounds such as allyl isothiocyanate (AITC, the active component of mustard oil) and other reactive electrophiles and may also be thermodetectors in many animal phyla. In this study, we provide the first pharmacological evidence of a putative TRPA1-like channel in the medicinal leech. The leech's polymodal nociceptive neuron was activated by both peripheral and central application of the TRPA1 agonist AITC in a concentration-dependent manner. Responses to AITC were inhibited by the selective TRPA1 antagonist HC030031, but also by the TRPV1 antagonist SB366791. Other TRPA1 activators - N-methylmaleimide (NMM) and cinnamaldehyde (CIN) - also activated this nociceptive neuron, although HC030031 only inhibited the effects of NMM. The polymodal nociceptive neurons responded to moderately cold thermal stimuli (<17°C) and these responses were blocked by HC030031. AITC sensitivity was also found in the pressure-sensitive sensory neurons and was blocked by HC030031, but not by SB366791. AITC elicited a nocifensive withdrawal of the posterior sucker in a concentration-dependent manner that could be attenuated with HC030031. Peripheral application of AITC in vivo also produced swimming-like behavior that was attenuated by HC030031. These results suggest the presence of a TRPA1-like channel in the medicinal leech nervous system that responds to cold temperatures and may interact with the leech TRPV-like channel.

  18. Purification and Characterization of a Novel Kazal-Type Trypsin Inhibitor from the Leech of Hirudinaria manillensis

    PubMed Central

    Lai, Yanmei; Li, Bowen; Liu, Weihui; Wang, Gan; Du, Canwei; Ombati, Rose; Lai, Ren; Long, Chengbo; Li, Hongyuan

    2016-01-01

    Kazal-type serine proteinase inhibitors are found in a large number of living organisms and play crucial roles in various biological and physiological processes. Although some Kazal-type serine protease inhibitors have been identified in leeches, none has been reported from Hirudinaria manillensis, which is a medically important leech. In this study, a novel Kazal-type trypsin inhibitor was isolated from leech H. manillensis, purified and named as bdellin-HM based on the sequence similarity with bdellin-KL and bdellin B-3. Structural analysis revealed that bdellin-HM was a 17,432.8 Da protein and comprised of 149 amino acid residues with six cysteines forming three intra-molecular disulfide bonds. Bdellin-HM showed similarity with the Kazal-type domain and may belong to the group of “non-classical” Kazal inhibitors according to its CysI-CysII disulfide bridge position. Bdellin-HM had no inhibitory effect on elastase, chymotrypsin, kallikrein, Factor (F) XIIa, FXIa, FXa, thrombin and plasmin, but it showed a potent ability to inhibit trypsin with an inhibition constant (Ki) of (8.12 ± 0.18) × 10−9 M. These results suggest that bdellin-HM from the leech of H. manillensis plays a potent and specific inhibitory role towards trypsin. PMID:27455325

  19. Identification and characterization of a novel neuropeptide (neuropeptide Y-HS) from leech salivary gland of Haemadipsa sylvestris.

    PubMed

    Liu, Wei-Hui; Chen, Yan; Bai, Xue-Wei; Yao, Hui-Min; Zhang, Xu-Guang; Yan, Xiu-Wen; Lai, Ren

    2016-09-01

    The present study was designed to identify immunomodulatory components from the leech salivary gland of Haemadipsa sylvestris. The Sephadex G-50, Resource(TM) S column chromatography and reverse-phase high performance liquid chromatography (RP-HPLC) were used to isolate and purify the salivary gland extracts (SGE). Structural analysis of isolated compounds was based on Edman degradation and matrix assisted laser desorption ionization time-of-flight mass spectrometer (MALDI-TOF-MS). The cDNA encoding the precursor of the compound was cloned from the cDNA library of the salivary gland of H. sylvestris. The levels of inflammatory mediators, including tumor necrosis factor-α (TNF-α), interferon γ (IFN-γ), interleukin-6 (IL-6), and monocyte chemotactic protein-1 (MCP-1) were assayed using an enzyme-linked immunosorbent assay (ELISA). The effects on cell proliferation and cell viability were observed using MTT assay. A novel neuropeptide Y (Neuropeptide Y-HS) from the leech salivary gland of H. sylvestris was purified and characterized. It was composed of 36 amino acid residues and the amino acid sequence was determined to be FLEPPERPAVFTSVEQMKSYIKALNDYYLLLGRPRF-NH2, containing an amidated C-terminus. It showed significant inhibitory effects on the production of inflammatory cytokines including TNF-α, IFN-γ, IL-6, and MCP-1. Neuropeptide Y was identified from leeches for the first time. The presence of neuropeptide Y-HS in leech salivary gland may help get blood meal from hosts and inhibit inflammation.

  20. Spatial-specific action of serotonin within the leech midbody ganglion.

    PubMed

    Calviño, María Ana; Szczupak, Lidia

    2008-06-01

    Serotonin is a conspicuous neuromodulator in the nervous system of many vertebrates and invertebrates. In previous experiments performed in the leech nervous system, we compared the effect of the amine released from endogenous sources [using selective serotonin reuptake inhibitors (SSRIs), e.g. fluoxetine] with that of bath-applied serotonin. The results suggested that the amine does not reach all its targets in a uniform way, but produces the activation of an interneuronal pathway that generated specific synaptic responses on different neurons. Taking into account that the release of the amine is often regulated at the presynaptic level, we have investigated whether autoreceptor antagonists mimic the SSRIs effect. We found that methiothepin (100 microM) produced similar effects than fluoxetine. To further test the hypothesis that endogenous serotonin produce its effect by acting locally at specific sites, we analyzed the effect of iontophoretic applications of serotonin. We found a site in the neuropil of the leech ganglia where serotonin application mimicked the effect of the SSRIs and the 5-HT antagonist. The results further support the view that the effect of serotonin exhibits a spatial specificity that can be relevant to understand its modulatory actions.

  1. Toxicity induced by cumene hydroperoxide in leech Retzius nerve cells: the protective role of glutathione.

    PubMed

    Jovanovic, Zorica; Jovanovic, Svetlana

    2013-01-01

    In the present study, we studied the ability of glutathione (GSH) to detoxify exogenously applied cumene hydroperoxide (CHP). Exposure of leech Retzius nerve cells to CHP (1.5 mM) induced a marked prolongation of the spontaneous spike potential of these cells. Early after depolarization, and a cardiac-like action potential with a rapid depolarization followed by a sustained depolarization or plateau, which is terminated by a rapid repolarization were recorded. GSH (0.2 mM) significantly inhibited the effects of CHP on the duration of the action potential and suppressed CHP-induced spontaneous repetitive activity. Voltage-clamp recordings showed that CHP (1.5 mM) caused significant changes in the outward potassium currents. The fast and slow steady part of the potassium outward current was reduced by 46% and 39%, respectively. GSH applied in a concentration of 0.2 mM partially blocked the effect of CHP on the calcium-activated potassium currents. The fast and slow calcium-activated potassium currents were suppressed by about 20% and 15%, respectively. These results suggest that the neurotoxic effect of CHP on spontaneous spike electrogenesis and calcium-activated potassium currents of leech Retzius nerve cells was reduced in the presence of GSH.

  2. Molecular basis of gap junctional communication in the CNS of the leech Hirudo medicinalis.

    PubMed

    Dykes, Iain M; Freeman, Fiona M; Bacon, Jonathan P; Davies, Jane A

    2004-01-28

    Gap junctions are intercellular channels that allow the passage of ions and small molecules between cells. In the nervous system, gap junctions mediate electrical coupling between neurons. Despite sharing a common topology and similar physiology, two unrelated gap junction protein families exist in the animal kingdom. Vertebrate gap junctions are formed by members of the connexin family, whereas invertebrate gap junctions are composed of innexin proteins. Here we report the cloning of two innexins from the leech Hirudo medicinalis. These innexins show a differential expression in the leech CNS: Hm-inx1 is expressed by every neuron in the CNS but not in glia, whereas Hm-inx2 is expressed in glia but not neurons. Heterologous expression in the paired Xenopus oocyte system demonstrated that both innexins are able to form functional homotypic gap junctions. Hm-inx1 forms channels that are not strongly gated. In contrast, Hm-inx2 forms channels that are highly voltage-dependent; these channels demonstrate properties resembling those of a double rectifier. In addition, Hm-inx1 and Hm-inx2 are able to cooperate to form heterotypic gap junctions in Xenopus oocytes. The behavior of these channels is primarily that predicted from the properties of the constituent hemichannels but also demonstrates evidence of an interaction between the two. This work represents the first demonstration of a functional gap junction protein from a Lophotrochozoan animal and supports the hypothesis that connexin-based communication is restricted to the deuterostome clade.

  3. New host and geographical records for the leech Acanthobdella peledina Grube 1851 (Hirudinea, Acanthobdellidae)

    USGS Publications Warehouse

    Hauck, A. K.; Fallon, Michael J.; Burger, Carl V.

    1979-01-01

    A total of four leeches (Acanthobdella peledina), parasitizing four specimens of the least cisco (Coregonus sardinella), were found during July and August 1977. The hosts and parasites were collected during a fishery survey by the U.S. Fish and Wildlife Service in the North Slope waters of Naval Petroleum Reserve, Alaska. Two host fishes were collected from the Chipp River (70035' latitude, 155012' longitude) and two from an unnamed, landlocked lake (69054' latitude, 153o23' longitude). The Chipp River collection site is about 130 km southeast of Barrow, and the unnamed lake about 200 km southeast of Barrow. The leeches, which were fixed in situ with neutral formalin, appeared to have penetrated the integument and were embedded in subcutaneous tissues and white muscle at the base of the pelvic fins. The specimens were cylindrical and about 23 mm long and 2-3 mm wide. Color before fixation was olive-green. The five anterior segments each had four pairs of hooked setae at the ventral surface. Our identification was based on a description in Bykhovskaya-Pavlovskaya et al., 1962, Key to parasites of freshwater fish of the USSR (Transl. from Russian), NTIS TT-64-11040.

  4. Expression and function of an even-skipped homolog in the leech Helobdella robusta.

    PubMed

    Song, Mi Hye; Huang, Françoise Z; Chang, Gwendolen Y; Weisblat, David A

    2002-08-01

    We have identified homologs of the Drosophila pair-rule gene even-skipped in the glossiphoniid leeches Helobdella robusta and Theromyzon trizonare. In leech embryos, segments arise sequentially from five pairs of embryonic stem cells (teloblasts) that undergo iterated divisions to generate columns (bandlets) of segmental founder cells (primary blast cells), which in turn generate segmentally iterated sets of definitive progeny. In situ hybridization revealed that Hro-eve is expressed in the teloblasts and primary blast cells, and that these transcripts appear to be associated with mitotic chromatin. In more advanced embryos, Hro-eve is expressed in segmentally iterated sets of cells in the ventral nerve cord. Lineage analysis revealed that neurons expressing Hro-eve arise from the N teloblast. To assess the function of Hro-eve, we examined embryos in which selected blastomeres had been injected with antisense Hro-eve morpholino oligonucleotide (AS-Hro-eve MO), concentrating on the primary neurogenic (N teloblast) lineage. Injection of AS-Hro-eve MO perturbed the normal patterns of teloblast and blast cell divisions and disrupted gangliogenesis. These results suggest that Hro-eve is important in regulating early cell divisions through early segmentation, and that it also plays a role in neuronal differentiation.

  5. The European land leech: biology and DNA-based taxonomy of a rare species that is threatened by climate warming

    NASA Astrophysics Data System (ADS)

    Kutschera, U.; Pfeiffer, I.; Ebermann, E.

    2007-12-01

    The European land leech Xerobdella lecomtei was discovered in 1868 and is one of the rarest animals on Earth. During the 1960s, several individuals of these approx. 40 mm long, cold-adapted terrestrial annelids that inhabit the moist soils of birch forests around Graz, Austria, were investigated. Only one original research paper has been published on the biology of this species. Between 2001 and 2005, we re-investigated the morphology of preserved specimens and searched for living individuals in their natural habitat that appeared to be intact. We found only one juvenile individual (length approx. 10 mm), indicating that this local leech population became largely extinct over the past four decades. The feeding behaviour of our ‘lonesome George of the annelids’ was studied and is described here in detail. After its death, the Xerobdella individual was used for chemical extraction and molecular studies (deoxyribonucleic acid [DNA] barcoding, based on one gene, the mitochondrial cytochrome c oxidase subunit I). In addition, novel DNA barcodes for a land leech from Madagascar and a recently discovered species from Europe were obtained. Our phylogenetic tree shows that X. lecomtei is not a member of the tropical land leeches (family Haemadipsidae), as previously thought, but represents a separate line of descent (family Xerobdellidae). The decline of the local leech population around Graz correlates with a rise in average summer temperatures of +3°C between 1961 and 2004. This warming led to a drastic reduction in the moisture content of the soil where X. lecomtei lives. We suggest that human-induced climate change without apparent habitat destruction can lead to the extinction of populations of cold-adapted species that have a low colonization ability.

  6. Helminth and leech community structure in tadpoles and caudatan larvae of two amphibian species from Western Nebraska.

    PubMed

    Rhoden, Heather R; Bolek, Matthew G

    2012-04-01

    Currently no comparative studies exist on helminth and leech community structure among sympatric anuran tadpoles and salamander larvae. During June-August 2007-2009, we examined 50 bullfrog tadpoles, Rana catesbeiana , 50 barred tiger salamander larvae, Ambystoma mavortium , and 3 species of snails from Nevens Pond, Keith County, Nebraska for helminth and leech infections. The helminth and leech compound community of this larval amphibian assemblage consisted of at least 7 species, 4 in bullfrog tadpoles and 4 in barred tiger salamander larvae. Bullfrog tadpoles were infected with 2 species of nematodes ( Gyrinicola batrachiensis and Spiroxys sp.) and 2 types of metacercariae ( Telorchis sp. and echinostomatids), whereas barred tiger salamander larva were infected with 1 species of leech ( Placobdella picta ), 2 species of adult trematodes ( Telorchis corti and Halipegus sp.), and 1 species of an unidentified metacercaria. The component community of bullfrog tadpoles was dominated by helminths acquired through active penetration, or incidentally ingested through respiratory currents, or both, whereas the component community of larval salamanders was dominated by helminths acquired through ingestion of intermediate hosts (χ²  =  3,455.00, P < 0.00001). Differences in amphibian larval developmental time (2-3 yr for bullfrog tadpoles versus 2-5 mo for salamander larvae), the ephemeral nature of intermediate hosts in Nevens Pond, and the ability of bullfrog tadpole to eliminate echinostome infections had significant effects on mean helminth species richness among amphibian species and years (t  =  12.31, P < 0.0001; t  =  2.09, P  =  0.04). Differences in herbivorous and carnivorous diet and time to metamorphosis among bullfrog tadpoles and barred tiger salamander larvae were important factors in structuring helminth communities among the larval stages of these 2 sympatric amphibian species, whereas size was important in structuring helminth and leech

  7. Field and experimental evidence of a new caiman trypanosome species closely phylogenetically related to fish trypanosomes and transmitted by leeches.

    PubMed

    Fermino, Bruno R; Paiva, Fernando; Soares, Priscilla; Tavares, Luiz Eduardo R; Viola, Laerte B; Ferreira, Robson C; Botero-Arias, Robinson; de-Paula, Cátia D; Campaner, Marta; Takata, Carmen S A; Teixeira, Marta M G; Camargo, Erney P

    2015-12-01

    Trypanosoma terena and Trypanosoma ralphi are known species of the South American crocodilians Caiman crocodilus, Caiman yacare and Melanosuchus niger and are phylogenetically related to the tsetse-transmitted Trypanosoma grayi of the African Crocodylus niloticus. These trypanosomes form the Crocodilian clade of the terrestrial clade of the genus Trypanosoma. A PCR-survey for trypanosomes in caiman blood samples and in leeches taken from caimans revealed unknown trypanosome diversity and frequent mixed infections. Phylogenies based on SSU (small subunit) of rRNA and gGAPDH (glycosomal Glyceraldehyde Phosphate Dehydrogenase) gene sequences revealed a new trypanosome species clustering with T. terena and T. ralphi in the crocodilian clade and an additional new species nesting in the distant Aquatic clade of trypanosomes, which is herein named Trypanosoma clandestinus n. sp. This new species was found in Caiman yacare, Caiman crocodilus and M. niger from the Pantanal and Amazonian biomes in Brazil. Large numbers of dividing epimastigotes and unique thin and long trypomastigotes were found in the guts of leeches (Haementeria sp.) removed from the mouths of caimans. The trypanosomes recovered from the leeches had sequences identical to those of T. clandestinus of caiman blood samples. Experimental infestation of young caimans (Caiman yacare) with infected leeches resulted in long-lasting T. clandestinus infections that permitted us to delineate its life cycle. In contrast to T. terena, T. ralphi and T. grayi, which are detectable by hemoculturing, microscopy and standard PCR of caiman blood, T. clandestinus passes undetected by these methods due to very low parasitemia and could be detected solely by the more sensitive nested PCR method. T. clandestinus n. sp. is the first crocodilian trypanosome known to be transmitted by leeches and positioned in the aquatic clade closest to fish trypanosomes. Our data show that caimans can host trypanosomes of the aquatic or

  8. The European land leech: biology and DNA-based taxonomy of a rare species that is threatened by climate warming.

    PubMed

    Kutschera, U; Pfeiffer, I; Ebermann, E

    2007-12-01

    The European land leech Xerobdella lecomtei was discovered in 1868 and is one of the rarest animals on Earth. During the 1960s, several individuals of these approx. 40 mm long, cold-adapted terrestrial annelids that inhabit the moist soils of birch forests around Graz, Austria, were investigated. Only one original research paper has been published on the biology of this species. Between 2001 and 2005, we re-investigated the morphology of preserved specimens and searched for living individuals in their natural habitat that appeared to be intact. We found only one juvenile individual (length approx. 10 mm), indicating that this local leech population became largely extinct over the past four decades. The feeding behaviour of our 'lonesome George of the annelids' was studied and is described here in detail. After its death, the Xerobdella individual was used for chemical extraction and molecular studies (deoxyribonucleic acid [DNA] barcoding, based on one gene, the mitochondrial cytochrome c oxidase subunit I). In addition, novel DNA barcodes for a land leech from Madagascar and a recently discovered species from Europe were obtained. Our phylogenetic tree shows that X. lecomtei is not a member of the tropical land leeches (family Haemadipsidae), as previously thought, but represents a separate line of descent (family Xerobdellidae). The decline of the local leech population around Graz correlates with a rise in average summer temperatures of +3 degrees C between 1961 and 2004. This warming led to a drastic reduction in the moisture content of the soil where X. lecomtei lives. We suggest that human-induced climate change without apparent habitat destruction can lead to the extinction of populations of cold-adapted species that have a low colonization ability.

  9. Field and experimental evidence of a new caiman trypanosome species closely phylogenetically related to fish trypanosomes and transmitted by leeches

    PubMed Central

    Fermino, Bruno R.; Paiva, Fernando; Soares, Priscilla; Tavares, Luiz Eduardo R.; Viola, Laerte B.; Ferreira, Robson C.; Botero-Arias, Robinson; de-Paula, Cátia D.; Campaner, Marta; Takata, Carmen S.A.; Teixeira, Marta M.G.; Camargo, Erney P.

    2015-01-01

    Trypanosoma terena and Trypanosoma ralphi are known species of the South American crocodilians Caiman crocodilus, Caiman yacare and Melanosuchus niger and are phylogenetically related to the tsetse-transmitted Trypanosoma grayi of the African Crocodylus niloticus. These trypanosomes form the Crocodilian clade of the terrestrial clade of the genus Trypanosoma. A PCR-survey for trypanosomes in caiman blood samples and in leeches taken from caimans revealed unknown trypanosome diversity and frequent mixed infections. Phylogenies based on SSU (small subunit) of rRNA and gGAPDH (glycosomal Glyceraldehyde Phosphate Dehydrogenase) gene sequences revealed a new trypanosome species clustering with T. terena and T. ralphi in the crocodilian clade and an additional new species nesting in the distant Aquatic clade of trypanosomes, which is herein named Trypanosoma clandestinus n. sp. This new species was found in Caiman yacare, Caiman crocodilus and M. niger from the Pantanal and Amazonian biomes in Brazil. Large numbers of dividing epimastigotes and unique thin and long trypomastigotes were found in the guts of leeches (Haementeria sp.) removed from the mouths of caimans. The trypanosomes recovered from the leeches had sequences identical to those of T. clandestinus of caiman blood samples. Experimental infestation of young caimans (Caiman yacare) with infected leeches resulted in long-lasting T. clandestinus infections that permitted us to delineate its life cycle. In contrast to T. terena, T. ralphi and T. grayi, which are detectable by hemoculturing, microscopy and standard PCR of caiman blood, T. clandestinus passes undetected by these methods due to very low parasitemia and could be detected solely by the more sensitive nested PCR method. T. clandestinus n. sp. is the first crocodilian trypanosome known to be transmitted by leeches and positioned in the aquatic clade closest to fish trypanosomes. Our data show that caimans can host trypanosomes of the aquatic or

  10. Encoding of Tactile Stimuli by Mechanoreceptors and Interneurons of the Medicinal Leech

    PubMed Central

    Kretzberg, Jutta; Pirschel, Friederice; Fathiazar, Elham; Hilgen, Gerrit

    2016-01-01

    For many animals processing of tactile information is a crucial task in behavioral contexts like exploration, foraging, and stimulus avoidance. The leech, having infrequent access to food, developed an energy efficient reaction to tactile stimuli, avoiding unnecessary muscle movements: The local bend behavior moves only a small part of the body wall away from an object touching the skin, while the rest of the animal remains stationary. Amazingly, the precision of this localized behavioral response is similar to the spatial discrimination threshold of the human fingertip, although the leech skin is innervated by an order of magnitude fewer mechanoreceptors and each midbody ganglion contains only 400 individually identified neurons in total. Prior studies suggested that this behavior is controlled by a three-layered feed-forward network, consisting of four mechanoreceptors (P cells), approximately 20 interneurons and 10 individually characterized motor neurons, all of which encode tactile stimulus location by overlapping, symmetrical tuning curves. Additionally, encoding of mechanical force was attributed to three types of mechanoreceptors reacting to distinct intensity ranges: T cells for touch, P cells for pressure, and N cells for strong, noxious skin stimulation. In this study, we provide evidences that tactile stimulus encoding in the leech is more complex than previously thought. Combined electrophysiological, anatomical, and voltage sensitive dye approaches indicate that P and T cells both play a major role in tactile information processing resulting in local bending. Our results indicate that tactile encoding neither relies on distinct force intensity ranges of different cell types, nor location encoding is restricted to spike count tuning. Instead, we propose that P and T cells form a mixed type population, which simultaneously employs temporal response features and spike counts for multiplexed encoding of touch location and force intensity. This hypothesis

  11. Effect of a nonspiking neuron on motor patterns of the leech.

    PubMed

    Rodriguez, Mariano J; Alvarez, Rodrigo J; Szczupak, Lidia

    2012-04-01

    Premotor and motoneurons could play regulatory roles in motor control. We have investigated the role of a premotor nonspiking (NS) neuron of the leech nervous system in two locomotive patterns: swimming and crawling. The NS neuron is coupled through rectifying electrical junctions to all the excitatory motoneurons examined. In addition, activation of motoneurons evokes chemically mediated inhibitory responses in NS. During swimming and crawling, the NS membrane potential (Vm(NS)) oscillated phase locked to the motor output. Hyperpolarization or depolarization of NS had no effect on swimming, but hyperpolarization of NS slowed down the crawling activity and decreased the motoneuron firing frequency. Depolarization of NS increased the motoneuron activity, and, at stages where the crawling pattern was fading, depolarization of NS reinstated it. Future work should determine if NS is actually a member of the central pattern generator or a regulatory element.

  12. Widespread inhibition proportional to excitation controls the gain of a leech behavioral circuit

    PubMed Central

    Kristan, William B.

    2014-01-01

    SUMMARY Changing gain in a neuronal system has important functional consequences, but the underlying mechanisms have been elusive. Models have suggested a variety of neuronal and systems properties to accomplish gain control. Here, we show that the gain of the neuronal network underlying local bending behavior in leeches depends on widespread inhibition. Using behavioral analysis, intracellular recordings, and voltage-sensitive dye imaging, we compared the effects of blocking just the known lateral inhibition with blocking all GABAergic inhibition. This revealed an additional source of inhibition, which was widespread and increased in proportion to increasing stimulus intensity. In a model of the input/output functions of the three-layered local bending network, we showed that inhibiting all interneurons in proportion to the stimulus strength produces the experimentally observed change in gain. This relatively simple mechanism for controlling behavioral gain could be prevalent in vertebrate as well as invertebrate nervous systems. PMID:18215624

  13. Development of swimming in the medicinal leech, the gradual acquisition of a behavior.

    PubMed

    French, K A; Chang, J; Reynolds, S; Gonzalez, R; Kristan, W B; Kristan, W B

    2005-09-01

    Observing the development of behavior provides an assay for the developmental state of an embryo's nervous system. We have previously described the development of behaviors that were largely confined to one or a few segments. We now extend the work to a kinematic analysis of the development of swimming, a behavior that requires coordination of the entire body. When leech embryos first begin to swim they make little forward progress, but within several days they swim as effectively as adults. This increase in efficacy depends on changes in body shape and on improved intersegmental coordination of the swim central pattern generator. These kinematic details suggest how the swim central pattern generating circuit is assembled during embryogenesis.

  14. Dextran backfill tracers combined with Lucifer yellow injections for neuroanatomic studies of the leech head ganglion.

    PubMed

    Daberkow, D P; Vaughan, D K

    1996-08-01

    Several neuronal tracing substances were applied to the cut ends of leech cephalic nerves and the resulting backfills into the subesophageal ganglion (sbEG) were mapped. A 12 h incubation in 3 kDa dextrans conjugated either to a fluorochrome or to biotin (subsequently tagged with peroxidase) was satisfactory. In separate experiments, possible targets of cephalic nerve afferents (R3 Retzius neurons) were injected with Lucifer Yellow (LY) to visualize their projections. Comparison of the LY-R3 Retzius neuron map with that of the dextran-backfilled D1 nerve revealed extensive overlap in the sbEG. Experiments were performed combining the two protocols, confirming this observation. Moreover, confocal microscopy placed D1 nerve processes in close proximity to R3 Retzius neuron processes, suggesting that they could make synaptic contact with one another in the sbEG. With modifications, this method could be used to identify such contacts using electron microscopy.

  15. Leech segmental repeats develop normally in the absence of signals from either anterior or posterior segments

    NASA Technical Reports Server (NTRS)

    Seaver, E. C.; Shankland, M.

    2000-01-01

    We have investigated whether the development of segmental repeats is autonomous in the embryo of the leech Helobdella robusta. The segmental tissues of the germinal band arise from progeny of five stem cells called teloblasts. Asymmetric divisions of the teloblasts form chains of segment founder cells (called primary blast cells) that divide in a stereotypical manner to produce differentiated descendants. Using two distinct techniques, we have looked for potential interactions between neighboring blast cell clones along the anterior-posterior axis. In one technique, we prevented the birth of primary blast cells by injection of DNase I into the teloblast, thereby depriving the last blast cell produced before the ablation of its normal posterior neighbors. We also ablated single blast cells with a laser microbeam, which allowed us to assess potential signals acting on either more anterior or more posterior primary blast cell clones. Our results suggest that interactions along the anterior-posterior axis between neighboring primary blast cell clones are not required for development of normal segmental organization within the blast cell clone. We also examined the possibility that blast cells receive redundant signals from both anterior and posterior neighboring clones and that either is sufficient for normal development. Using double blast cell laser ablations to isolate a primary blast cell clone by removal of both its anterior and its posterior neighbor, we found that the isolated clone still develops normally. These results reveal that the fundamental segmental repeat in the leech embryo, the primary blast cell clone, can develop normally in the apparent absence of signals from adjacent repeats along the anterior-posterior axis.

  16. Acetyl-L-carnitine affects nonassociative learning processes in the leech Hirudo medicinalis.

    PubMed

    Ristori, C; Cataldo, E; Zaccardi, M L; Traina, G; Calvani, M; Lombardo, P; Scuri, R; Brunelli, M

    2006-11-03

    Acetyl-L-carnitine is a natural molecule widely distributed in vertebrate and invertebrate nervous system. It is known to have significant effects on neuronal activity playing a role as neuroprotective and anti-nociceptive agent, as well as neuromodulatory factor. About its capability of affecting learning processes the available data are controversial. In the present study, we utilized the simplified model system of the leech Hirudo medicinalis to analyze the effects of acetyl-L-carnitine, assessing whether and how it might affect elementary forms of nonassociative learning processes. In leeches with the head ganglion disconnected from the first segmental ganglion, repetitive application of weak electrical shocks onto the caudal portion of the body wall induces habituation of swim induction whereas brush strokes on the dorsal skin produces sensitization or dishabituation when the nociceptive stimulus is delivered on previously habituated animals. Herein, the effects of different concentrations of acetyl-L-carnitine (2 mM - 0.05 mM) have been tested at different times on both sensitization and dishabituation. The results show that a single treatment of acetyl-L-carnitine blocked the onset of sensitization in a dose- and time-dependent manner. In fact, the most effective concentration able to block this process was 2 mM, which induced its major effects 11 days after the treatment, whereas 0.05 mM was unable to affect the sensitization process at all considered time points. On the contrary, acetyl-L-carnitine did not completely abolish dishabituation at the tested concentrations and at every time point. Finally, acetyl-L-carnitine also impaired the habituation of swim induction, but only 11 days after treatment.

  17. Forskolin induces NMDA receptor-dependent potentiation at a central synapse in the leech.

    PubMed

    Grey, Kathryn B; Burrell, Brian D

    2008-05-01

    In vertebrate hippocampal neurons, application of forskolin (an adenylyl cyclase activator) and rolipram (a phosphodiesterase inhibitor) is an effective technique for inducing chemical long-term potentiation (cLTP) that is N-methyl-d-aspartate (NMDA) receptor (NMDAR)-dependent. However, it is not known whether forskolin induces a similar potentiation in invertebrate synapses. Therefore, we examined whether forskolin plus rolipram treatment could induce potentiation at a known glutamatergic synapse in the leech (Hirudo sp.), specifically between the pressure (P) mechanosensory and anterior pagoda (AP) neurons. Perfusion of isolated ganglia with forskolin (50 muM) in conjunction with rolipram (0.1 muM) in Mg(2+)-free saline significantly potentiated the P-to-AP excitatory postsynaptic potential. Application of 2-amino-5-phosphonovaleric acid (APV, 100 muM), a competitive NMDAR antagonist, blocked the potentiation, indicating P-to-AP potentiation is NMDAR-dependent. Potentiation was blocked by injection of bis-(o-aminophenoxy)-N,N,N',N'-tetraacetic acid (BAPTA, 1 mM) into the postsynaptic cell, but not by BAPTA injection into the presynaptic neuron, indicating a requirement for postsynaptic elevation of intracellular Ca(2+). Application of db-cAMP mimicked the potentiating effects of forskolin, and Rp-cAMP, an inhibitor of protein kinase A, blocked forskolin-induced potentiation. Potentiation was also blocked by autocamtide-2-related inhibitory peptide (AIP), indicating a requirement for activation of Ca(2+)/calmodulin-dependent kinase II (CaMKII). Finally, potentiation was blocked by botulinum toxin, suggesting that trafficking of glutamate receptors also plays a role in this form of synaptic plasticity. These experiments demonstrate that techniques used to induce cLTP in vertebrate synapses also induce NMDAR-dependent potentiation in the leech CNS and that many of the cellular processes that mediate LTP are conserved between vertebrate and invertebrate phyla.

  18. Flavobacterium cutihirudinis sp. nov., isolated from the skin of the medical leech Hirudo verbana.

    PubMed

    Glaeser, S P; Galatis, H; Martin, K; Kämpfer, P

    2013-08-01

    A Gram-staining-negative, non-endospore-forming, yellow-pigmented strain (E89(T)) was isolated from the skin of the medical leech Hirudo verbana obtained from a leech farm located in Biebertal, Germany. 16S rRNA gene sequencing analysis showed that the isolate was grouped in the genus Flavobacterium. Strain E89(T) was most closely related to Flavobacterium chilense LM-09-Fp(T) (98.2 %), Flavobacterium chungangense CJ7(T) (98.1 %), and Flavobacterium oncorhynchi 631-08(T) (98.1 %). 16S rRNA gene sequence similarities to all other species of the genus Flavobacterium were ≤ 97.4 %. A menaquinone of the type MK-6 was found to be the predominant respiratory quinone and the polar lipid profile consisted of the major compounds phosphatidylethanolamine, phosphatidylserine, two unidentified aminolipids, one unknown phospholipid and two unknown lipids. The fatty acid profile was composed of iso-C15 : 0, C15 : 0, summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH) found in major amounts and several hydroxylated fatty acids in smaller amounts, among them iso-C15 : 0 3-OH and iso-C17 : 0 3-OH. All these data support the allocation of the isolate in the genus Flavobacterium. Physiological/biochemical characterization and DNA-DNA hybridizations with the type strains of the most closely related species allowed a clear phenotypic and genotypic differentiation of the strain. Based on these data, strain E89(T) represents a novel species of the genus Flavobacterium, for which the name Flavobacterium cutihirudinis sp. nov. is proposed. The type strain is E89(T) (= DSM 25795(T) = LMG 26922(T) = CIP 110374(T)).

  19. From the Worm in a Bottle of Mezcal: iDNA Confirmation of a Leech Parasitizing the Antillean Manatee.

    PubMed

    Pérez-Flores, J; Rueda-Calderon, H; Kvist, S; Siddall, M E; Oceguera-Figueroa, A

    2016-10-01

    Invertebrate-derived ingested DNA (iDNA) is quickly proving to be a valuable, non-invasive tool for monitoring vertebrate species of conservation concern. Using the DNA barcoding locus, we successfully identified both the blood-feeding leech Haementeria acuecueyetzin and its blood meal-the latter is shown to be derived from the Caribbean manatee, Trichechus manatus . DNA amplification was successful despite the fact that the specimen was fixed in Mezcal (a beverage distilled from agave). We report the first confirmed case of a leech feeding on a manatee, the first record of H. acuecueyetzin for the State of Chiapas and, to our knowledge, the first case of successful DNA amplification of a biological sample fixed in Mezcal other than the caterpillar "worms" more commonly found in that beverage.

  20. Sublethal effects of crude oil on a cold-water marine leech, Johanssonia arcitca, following chronic exposure

    SciTech Connect

    Khan, R.A. ); Kiceniuk, J.W. )

    1989-10-01

    Petroleum polyaromatic hydrocarbons (PAH) are known to affect many species of animals. Mortality and/or morbidity from acute toxicity are usually restricted to the immediate vicinity of a spill, seep or discharge. Subtle effects are sometimes not recognized unless long term observations are made. Several studies have shown that some species of invertebrates tend to accumulate and retain petroleum hydrocarbons for varying periods, sometimes with detrimental effects. In a previous communication, it was noted that water soluble fractions (WSF) of a crude oil distributed digestion and affected reproduction of a hematophagous marine leech, Johanssonia arctica. This leech is a benthic, cold-adapted species that is widely distributed on the continental shelf off eastern Canada especially on the Grand Banks where petroleum reserves have been recently discovered. The present study provides additional evidence that crude oil fractions not only alters egg production but also hatching of eggs and survival of the progeny.

  1. Comparative Mitogenomics of Leeches (Annelida: Clitellata): Genome Conservation and Placobdella-Specific trnD Gene Duplication

    PubMed Central

    Moya, Andrés; Siddall, Mark E.; Latorre, Amparo

    2016-01-01

    Mitochondrial DNA sequences, often in combination with nuclear markers and morphological data, are frequently used to unravel the phylogenetic relationships, population dynamics and biogeographic histories of a plethora of organisms. The information provided by examining complete mitochondrial genomes also enables investigation of other evolutionary events such as gene rearrangements, gene duplication and gene loss. Despite efforts to generate information to represent most of the currently recognized groups, some taxa are underrepresented in mitochondrial genomic databases. One such group is leeches (Annelida: Hirudinea: Clitellata). Herein, we expand our knowledge concerning leech mitochondrial makeup including gene arrangement, gene duplication and the evolution of mitochondrial genomes by adding newly sequenced mitochondrial genomes for three bloodfeeding species: Haementeria officinalis, Placobdella lamothei and Placobdella parasitica. With the inclusion of three new mitochondrial genomes of leeches, a better understanding of evolution for this organelle within the group is emerging. We found that gene order and genomic arrangement in the three new mitochondrial genomes is identical to previously sequenced members of Clitellata. Interestingly, within Placobdella, we recovered a genus-specific duplication of the trnD gene located between cox2 and atp8. We performed phylogenetic analyses using 12 protein-coding genes and expanded our taxon sampling by including GenBank sequences for 39 taxa; the analyses confirm the monophyletic status of Clitellata, yet disagree in several respects with other phylogenetic hypotheses based on morphology and analyses of non-mitochondrial data. PMID:27176910

  2. Comparative Mitogenomics of Leeches (Annelida: Clitellata): Genome Conservation and Placobdella-Specific trnD Gene Duplication.

    PubMed

    Oceguera-Figueroa, Alejandro; Manzano-Marín, Alejandro; Kvist, Sebastian; Moya, Andrés; Siddall, Mark E; Latorre, Amparo

    2016-01-01

    Mitochondrial DNA sequences, often in combination with nuclear markers and morphological data, are frequently used to unravel the phylogenetic relationships, population dynamics and biogeographic histories of a plethora of organisms. The information provided by examining complete mitochondrial genomes also enables investigation of other evolutionary events such as gene rearrangements, gene duplication and gene loss. Despite efforts to generate information to represent most of the currently recognized groups, some taxa are underrepresented in mitochondrial genomic databases. One such group is leeches (Annelida: Hirudinea: Clitellata). Herein, we expand our knowledge concerning leech mitochondrial makeup including gene arrangement, gene duplication and the evolution of mitochondrial genomes by adding newly sequenced mitochondrial genomes for three bloodfeeding species: Haementeria officinalis, Placobdella lamothei and Placobdella parasitica. With the inclusion of three new mitochondrial genomes of leeches, a better understanding of evolution for this organelle within the group is emerging. We found that gene order and genomic arrangement in the three new mitochondrial genomes is identical to previously sequenced members of Clitellata. Interestingly, within Placobdella, we recovered a genus-specific duplication of the trnD gene located between cox2 and atp8. We performed phylogenetic analyses using 12 protein-coding genes and expanded our taxon sampling by including GenBank sequences for 39 taxa; the analyses confirm the monophyletic status of Clitellata, yet disagree in several respects with other phylogenetic hypotheses based on morphology and analyses of non-mitochondrial data.

  3. Distribution and functional properties of glutamate receptors in the leech central nervous system.

    PubMed

    Dierkes, P W; Hochstrate, P; Schlue, W R

    1996-06-01

    1. The effect of kainate and other glutamatergic agonists on the membrane potential (Em), the intracellular Na+ activity (aNai), and the intracellular free Ca2+ concentration ([Ca2+]i) of identified leech neurons and neuropile glial cells was measured with conventional and ion-sensitive microelectrodes, as well as with the use of the iontophoretically injected fluorescent indicators sodium-binding benzofuran isophthalate and Fura-2. 2. In Retzius neurons, AE, L, 8, and 101 motoneurons, and in the unclassified 50 neurons (Leydig cells) and AP neurons, as well as in neuropile glial cells, bath application of 100 microM kainate evoked a marked membrane depolarization and an increase in aNai and [Ca2+]i. The kainate-induced aNai increase persisted in solutions with high Mg2+ concentration in which synaptic transmission is blocked. 3. A membrane depolarization as well as an increase in aNai and [Ca2+]i was also evoked by L-glutamate, quisqualate, and L-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA). The agonist-induced [Ca2+]i increase was inhibited by 6,7-dinitroquinoxaline-2,3-dione (DNQX). 4. In Ca(2+)-free solution, the kainate-induced [Ca2+]i increase was abolished in the neurons and in neuropile glial cells, whereas membrane depolarization and aNai increase were unchanged. In Na(+)-free solution, kainate had no effect on Em, aNai, or [Ca2+]i in the neurons. 5. In the mechanosensory T, P, and N neurons, kainate induced considerably smaller membrane depolarizations than in the other neurons or in neuropile glial cells, and it had no significant effect on aNai or [Ca2+]i. 6. It is concluded that in leech segmental ganglia the majority of the neurons and the neuropile glial cells, but probably not the mechanosensory neurons, possess glutamate receptors of the AMPA-kainate type. In the neurons, the [Ca2+]i increase caused by glutamatergic agonists is due to Ca2+ influx through voltage-dependent Ca2+ channels that are activated by the agonist

  4. The Ozobranchus leech as a mechanical vector for the fibropapilloma-associated turtle herpes virus found latently infecting skin tumors on Hawaiian green turtles (Chelonia mydas)

    USGS Publications Warehouse

    Greenblatt, R.J.; Work, T.M.; Balazs, G.; Sutton, C.A.; Casey, R.N.; Casey, J.W.

    2004-01-01

    Fibropapillomatosis (FP) of marine turtles is a neoplastic disease of ecological concern. A fibropapilloma-associated turtle herpesvirus (FPTHV) is consistently present, usually at loads exceeding one virus copy per tumor cell. DNA from an array of parasites of green turtles (Chelonia mydas) was examined with quantitative PCR (qPCR) to determine whether any carried viral loads are sufficient to implicate them as vectors for FPTHV. Marine leeches (Ozobranchus spp.) were found to carry high viral DNA loads; some samples approached 10 million copies per leech. Isopycnic sucrose density gradient/qPCR analysis confirmed that some of these copies were associated with particles of the density of enveloped viruses. The data implicate the marine leech Ozobranchus as a mechanical vector for FPTHV. Quantitative RT-PCR analysis of FPTHV gene expression indicated that most of the FPTHV copies in a fibropapilloma have restricted DNA polymerase expression, suggestive of latent infection.

  5. Asymmetric cell divisions in the early embryo of the leech Helobdella robusta.

    PubMed

    Weisblat, David A

    2007-01-01

    The small glossiphoniid leech Helobdella robusta is among the best-studied representatives of the super-phylum Lophotrochozoa in terms of early development. The Helobdella embryo undergoes a modified version of spiral cleavage, characterized by stereotyped cell lineages comprising multiple examples of equal and unequal divisions, many of which are well-conserved with respect to those of other clitellate annelids, such as the oligochaete Tubifex. Here, we review the early development of Helobdella, focusing on the variety of unequal cell divisions. We then summarize an experimental analysis of the mechanisms underlying the unequal first cleavage in Helobdella, concluding that the unequal first cleavages in Helobdella and Tubifex proceed by different mechanisms. This result demonstrates the evolvability of the basic cell biological mechanisms underlying well-conserved developmental processes. Finally, we propose a model in which the unequal second cleavage in Helobdella may be regulated by the polarized distribution of PAR protein homologs, convergent with the unequal first cleavage of the nematode Caenorhabditis elegans (super-phylum Ecdysozoa).

  6. Maintenance of Fura-2 fluorescence in glial cells and neurons of the leech central nervous system.

    PubMed

    Munsch, T; Deitmer, J W

    1995-04-01

    Identified glial cells and neurones of the leech central nervous system (CNS) were injected iontophoretically with the calcium indicator dye Fura-2 to measure intracellular Ca2+, while simultaneously recording the membrane potential using a double-barrelled theta-type microelectrode. Both glial cells and neurones responded with Ni(2+)-sensitive Ca2+ transients upon membrane depolarization, indicating Ca2+ influx through voltage-gated Ca2+ channels. In contrast to neurones, the glial cells showed a rapid loss of fluorescence with a half-time of 6.3 +/- 1.8 min (n = 6) after dye injection. Both kinetics and amplitudes of the stimulus-induced Ca2+ transients were affected by this rapid dye loss. The anion exchange inhibitor probenicid (2 mM) significantly reduced, but did not prevent, the loss of Fura-2 fluorescence, suggesting that some dye left the glial cell via an anion exchanger. In order to compensate this fluorescence loss, we injected Fura-2 throughout the experiment. Under this condition, similar Ca2+ transients could be elicited repeatedly for more than 1 h. In Retzius neurones single injections of Fura-2 yielded enough intracellularly trapped dye to allow measurement of intracellular Ca2+ for up to 30 min after the end of injection without large decrease in absolute fluorescence.

  7. Embryonic electrical connections appear to pre-figure a behavioral circuit in the leech CNS.

    PubMed

    Marin-Burgin, Antonia; Eisenhart, F James; Kristan, William B; French, Kathleen A

    2006-02-01

    During development, many embryos show electrical coupling among neurons that is spatially and temporally regulated. For example, in vertebrate embryos extensive dye coupling is seen during the period of circuit formation, suggesting that electrical connections could pre-figure circuits, but it has been difficult to identify which neuronal types are coupled. We have used the leech Hirudo medicinalis to follow the development of electrical connections within the circuit that produces local bending. This circuit consists of three layers of neurons: four mechanosensory neurons (P cells), 17 identified interneurons, and approximately 24 excitatory and inhibitory motor neurons. These neurons can be identified in embryos, and we followed the spatial and temporal dynamics as specific connections developed. Injecting Neurobiotin into identified cells of the circuit revealed that electrical connections were established within this circuit in a precise manner from the beginning. Connections first appeared between motor neurons; mechanosensory neurons and interneurons started to connect at least a day later. This timing correlates with the development of behaviors, so the pattern of emerging connectivity could explain the appearance first of spontaneous behaviors (driven by a electrically coupled motor network) and then of evoked behaviors (when sensory neurons and interneurons are added to the circuit).

  8. From synapses to behavior: development of a sensory-motor circuit in the leech.

    PubMed

    Marin-Burgin, Antonia; Kristan, William B; French, Kathleen A

    2008-05-01

    The development of neuronal circuits has been advanced greatly by the use of imaging techniques that reveal the activity of neurons during the period when they are constructing synapses and forming circuits. This review focuses on experiments performed in leech embryos to characterize the development of a neuronal circuit that produces a simple segmental behavior called "local bending." The experiments combined electrophysiology, anatomy, and FRET-based voltage-sensitive dyes (VSDs). The VSDs offered two major advantages in these experiments: they allowed us to record simultaneously the activity of many neurons, and unlike other imaging techniques, they revealed inhibition as well as excitation. The results indicated that connections within the circuit are formed in a predictable sequence: initially neurons in the circuit are connected by electrical synapses, forming a network that itself generates an embryonic behavior and prefigures the adult circuit; later chemical synapses, including inhibitory connections, appear, "sculpting" the circuit to generate a different, mature behavior. In this developmental process, some of the electrical connections are completely replaced by chemical synapses, others are maintained into adulthood, and still others persist and share their targets with chemical synaptic connections.

  9. Transmission at a 'direct' electrical connexion mediated by an interneurone in the leech.

    PubMed Central

    Muller, K J; Scott, S A

    1981-01-01

    1. Touch sensory neurones in the leech excite a rapidly conducting interneurone called the S-cell. Although the electrical synaptic connexion between the two cells is monosynaptic by physiological criteria, intracellular staining reveals that the touch cells and the S-cell do not make contact, but instead are linked by a pair of small interneurones. 2. The electrical coupling between touch cells and S-cells rectifies, in that depolarizing current but not hyperpolarizing current passes from the touch cell into the S-cell. The rectifying junction is between the touch cells and coupling interneurones, while the connexion between coupling interneurones and the S-cell passes current in both directions. 3. Selective destruction of the coupling interneurones by intracellular injection of a protease interrupts the disynaptic electrical connexion between touch and S-cells. 4. The touch cell's geometry and membrane properties account for the failure of impulses that are generated in certain portions of the receptive field in the skin to propagate beyond the first branch-points of the touch cell axon within the ganglion. Conduction block at branch-points is used to examine physiologically the spatial distribution of contacts between the touch cell and the coupling interneurones. In addition, it is shown that under natural conditions branch-point failure presynaptically reduces the effectiveness of the electrical synaptic connexions. Images Plate 1 Plate 2 Plate 3 Plate 4 PMID:6267257

  10. A Tale of Transmission: Aeromonas veronii Activity within Leech-Exuded Mucus

    PubMed Central

    Ott, Brittany M.; Dacks, Andrew M.; Ryan, Kenneth J.

    2016-01-01

    Transmission, critical to the establishment and persistence of host-associated microbiotas, also exposes symbionts to new environmental conditions. With horizontal transmission, these different conditions represent major lifestyle shifts. Yet genome-wide analyses of how microbes adjust their transcriptomes toward these dramatic shifts remain understudied. Here, we provide a comprehensive and comparative analysis of the global transcriptional profiles of a symbiont as it shifts between lifestyles during transmission. The gammaproteobacterium Aeromonas veronii is transmitted from the gut of the medicinal leech to other hosts via host mucosal castings, yet A. veronii can also transition from mucosal habitancy to a free-living lifestyle. These three lifestyles are characterized by distinct physiological constraints and consequently lifestyle-specific changes in the expression of stress-response genes. Mucus-bound A. veronii had the greatest expression in terms of both the number of loci and levels of transcription of stress-response mechanisms. However, these bacteria are still capable of proliferating within the mucus, suggesting the availability of nutrients within this environment. We found that A. veronii alters transcription of loci in a synthetic pathway that obtains and incorporates N-acetylglucosamine (NAG; a major component of mucus) into the bacterial cell wall, enabling proliferation. Our results demonstrate that symbionts undergo dramatic local adaptation, demonstrated by widespread transcriptional changes, throughout the process of transmission that allows them to thrive while they encounter new environments which further shape their ecology and evolution. PMID:26896136

  11. Riluzole suppresses postinhibitory rebound in an excitatory motor neuron of the medicinal leech.

    PubMed

    Angstadt, James D; Simone, Amanda M

    2014-08-01

    Postinhibitory rebound (PIR) is an intrinsic property often exhibited by neurons involved in generating rhythmic motor behaviors. Cell DE-3, a dorsal excitatory motor neuron in the medicinal leech exhibits PIR responses that persist for several seconds following the offset of hyperpolarizing stimuli and are suppressed in reduced Na(+) solutions or by Ca(2+) channel blockers. The long duration and Na(+) dependence of PIR suggest a possible role for persistent Na(+) current (I NaP). In vertebrate neurons, the neuroprotective agent riluzole can produce a selective block of I NaP. This study demonstrates that riluzole inhibits cell DE-3 PIR in a concentration- and Ca(2+)-dependent manner. In 1.8 mM Ca(2+) solution, 50-100 µM riluzole selectively blocked the late phase of PIR, an effect similar to that of the neuromodulator serotonin. However, 200 µM riluzole blocked both the early and late phases of PIR. Increasing extracellular Ca(2+) to 10 mM strengthened PIR, but high riluzole concentrations continued to suppress both phases of PIR. These results indicate that riluzole may suppress PIR via a nonspecific inhibition of Ca(2+) conductances and suggest that a Ca(2+)-activated nonspecific current (I(CAN)), rather than I NaP, may underlie the Na(+)-dependent component of PIR.

  12. Identification of iron and heme utilization genes in Aeromonas and their role in the colonization of the leech digestive tract

    PubMed Central

    Maltz, Michele; LeVarge, Barbara L.; Graf, Joerg

    2015-01-01

    It is known that many pathogens produce high-affinity iron uptake systems like siderophores and/or proteins for utilizing iron bound to heme-containing molecules, which facilitate iron-acquisition inside a host. In mutualistic digestive-tract associations, iron uptake systems have not been as well studied. We investigated the importance of two iron utilization systems within the beneficial digestive-tract association Aeromonas veronii and the medicinal leech, Hirudo verbana. Siderophores were detected in A. veronii using chrome azurol S. Using a mini Tn5, a transposon insertion in viuB generated a mutant unable to utilize iron using siderophores. The A. veronii genome was then searched for genes potentially involved in iron utilization bound to heme-containing molecules. A putative outer membrane heme receptor (hgpB) was identified with a transcriptional activator, termed hgpR, downstream. The hgpB gene was interrupted with an antibiotic resistance cassette in both the parent strain and the viuB mutant, yielding an hgpB mutant and a mutant with both iron uptake systems inactivated. In vitro assays indicated that hgpB is involved in utilizing iron bound to heme and that both iron utilization systems are important for A. veronii to grow in blood. In vivo colonization assays revealed that the ability to acquire iron from heme-containing molecules is critical for A. veronii to colonize the leech gut. Since iron and specifically heme utilization is important in this mutualistic relationship and has a potential role in virulence factor of other organisms, genomes from different Aeromonas strains (both clinical and environmental) were queried with iron utilization genes of A. veronii. This analysis revealed that in contrast to the siderophore utilization genes heme utilization genes are widely distributed among aeromonads. The importance of heme utilization in the colonization of the leech further confirms that symbiotic and pathogenic relationships possess similar

  13. Role of the tissue free amino acids in adaptation of medicinal leeches Hirudo medicinalis L., 1758 to extreme climatic conditions.

    PubMed

    Chernaya, L V; Kovalchuk, L A; Nokhrina, E S

    2016-01-01

    The first comparison of the spectra of free amino acids in tissues of the medicinal leeches H. medicinalis from different climatic and geographical Eurasian areas has been performed. Adaptation of H. medicinalis to extreme climatic conditions occurs via intensification of the amino acid metabolism resulting from a significant increase in the content of essential amino acids. Accumulation of arginine, histidine, and lysine (3.6-, 3.9-, and 2.0-fold increases, respectively) has proved to play a special protective role in adaptation of H. medicinalis to the low positive temperatures.

  14. Sodium-magnesium antiport in Retzius neurones of the leech Hirudo medicinalis.

    PubMed Central

    Günzel, D; Schlue, W R

    1996-01-01

    1. Intracellular free magnesium ([Mg2+]i) and sodium ([Na+]i) concentrations were measured in Retzius neurones of the leech Hirudo medicinalis using ion-sensitive microelectrodes. 2. The mean steady-state values for [Mg2+]i and [Na+]i were 0.46 mM (pMg, 3.34 +/- 0.23; range, 0.1-1.2 mM; n = 32) and 8.95 mM (pNa, 2.05 +/- 0.15; range, 5.1-15.5 mM, n = 21), respectively, at a mean membrane potential (Em) of -35.6 +/- 6.1 mV (n = 32). Thus, [Mg2+]i is far below the value calculated for a passive distribution (16.9 mM) but close to the equilibrium value calculated for a hypothetical 1 Na(+)-1 Mg2+ antiport (0.41 mM). 3. Simultaneous measurements of [Mg2+]i, [Na+]i and Em in Retzius neurones showed that an increase in the extracellular Mg2+ concentration ([Mg2+]o) resulted in an increase in [Mg2+]i, a parallel decrease in [Na+]i and a membrane depolarization, while a decrease in [Mg2+]o had opposite effects. These results are compatible with calculations based on a 1 Na(+)-1 Mg2+ antiport. 4. Na+ efflux at high [Mg2+]o still occurred when the Na(+)-K+ pump was inhibited by the application of ouabain or in K(+)-free solutions. This efflux was blocked by amiloride. 5. In the absence of extracellular Na+ ([Na+]o), no Mg2+ influx occurred. Mg2+ influx at high [Mg2+]o was even lower than in the presence of [Na+]o. Mg2+ efflux was blocked in the absence of [Na+]o. 6. The rate of Mg2+ extrusion was reduced by lowering [Na+]o, even if the Na+ gradient across the membrane remained almost unchanged. 7. Mg2+ efflux was blocked by amiloride (half-maximal effect at 0.25 mM amiloride; Hill coefficient, 1.3) but not by 5-(N-ethyl-N-isopropyl)-amiloride (EIPA). 8. No changes in intracellular Ca2+ and pH (pHi) could be detected when [Mg2+]o was varied between 1 and 30 mM. 9. Changing pHi by up to 0.4 pH units had no effect on [Mg2+]i. 10. The results suggest the presence of an electrogenic 1 Na(+)-1 Mg2+ antiport in leech Retzius neurones. This antiport can be reversed and is inhibited

  15. Creation and reduction of a morphologically detailed model of a leech heart interneuron

    PubMed Central

    Tobin, Anne-Elise; Van Hooser, Stephen D.; Calabrese, Ronald L.

    2010-01-01

    Conductance-based neuron models aid in understanding the role intrinsic and synaptic currents play in producing neuronal activity. Incorporating morphological detail into a model allows for additional analysis of non-homogeneous distributions of active and synaptic conductances, as well as spatial segregation of electrical events. We developed a morphologically detailed “Full Model” of a leech heart interneuron that replicates reasonably well intracellular recordings from these interneurons. However, it comprises hundreds of compartments, each increasing parameter space and simulation time. To reduce the number of compartments of the Full Model, while preserving conductance densities and distributions, its compartments were grouped into functional groups that each share identical conductance densities. Each functional group was sequentially reduced to one or two compartments, preserving surface area, conductance densities and its contribution to input resistance. As a result, the input resistance and membrane time constant were preserved. The axial resistances of several compartments were rescaled to match the amplitude of synaptic currents and low-threshold calcium currents and the shape of action potentials to those in the Full Model. This reduced model, with intrinsic conductances, matched the activity of the Full Model for a variety of simulated current-clamp and voltage-clamp data. Because surface area and conductance distribution of the functional groups of the Full Model were maintained, parameter changes introduced into the reduced model can be directly translated to the Full Model. Thus, our computationally efficient reduced morphology model can be used as a tool for exploring the parameter space of the Full Model and in network simulations. PMID:16760352

  16. Endogenous and half-center bursting in morphologically-inspired models of leech heart interneurons

    PubMed Central

    Tobin, Anne-Elise; Calabrese, Ronald L.

    2010-01-01

    Based on a detailed morphology ‘Full Model’ of a leech heart interneuron, we previously developed a computationally-efficient, morphologically-inspired ‘Reduced Model’ to expedite tuning the model to produce endogenous bursting and alternating bursting when configured as a half-center oscillator (paired with reciprocally inhibitory synapses). To find conductance density distributions that produce endogenous bursting, we implemented a genetic algorithm automated parameter search. With multiple searches, we found eight parameter sets that produced endogenous bursting in the Reduced Model. When these parameter sets were applied to the Full Model, all produced endogenous bursting, although when the simulation time was extended from 80 s to 300 s, only four parameter sets produced sustained bursting in the Reduced Models. All parameter sets produced alternating half-center bursting in the Reduced and Full Models throughout 300 s. When conductance amplitudes were systematically varied for each of the four sustained burster sets, the effects on bursting activity differed, both for the same parameter set in the Reduced and Full Models and for different parameter sets with the same level of morphological detail. This implies that morphological detail can affect burst activity and that these parameter sets may represent different mechanisms for burst generation and/or regulation. We also tested the models with parameter variations that correspond to experimental manipulations. We conclude that whereas similar output can be achieved with multiple different parameter sets, perturbations such as conductance variations can highlight differences. Additionally, this work demonstrates both the utility and limitations of using simplified models to represent more morphologically-accurate models. PMID:16760353

  17. Deciphering the Structural Basis That Guides the Oxidative Folding of Leech-derived Tryptase Inhibitor*

    PubMed Central

    Pantoja-Uceda, David; Arolas, Joan L.; Aviles, Francesc X.; Santoro, Jorge; Ventura, Salvador; Sommerhoff, Christian P.

    2009-01-01

    Protein folding mechanisms have remained elusive mainly because of the transient nature of intermediates. Leech-derived tryptase inhibitor (LDTI) is a Kazal-type serine proteinase inhibitor that is emerging as an attractive model for folding studies. It comprises 46 amino acid residues with three disulfide bonds, with one located inside a small triple-stranded antiparallel β-sheet and with two involved in a cystine-stabilized α-helix, a motif that is widely distributed in bioactive peptides. Here, we analyzed the oxidative folding and reductive unfolding of LDTI by chromatographic and disulfide analyses of acid-trapped intermediates. It folds and unfolds, respectively, via sequential oxidation and reduction of the cysteine residues that give rise to a few 1- and 2-disulfide intermediates. Species containing two native disulfide bonds predominate during LDTI folding (IIa and IIc) and unfolding (IIa and IIb). Stop/go folding experiments demonstrate that only intermediate IIa is productive and oxidizes directly into the native form. The NMR structures of acid-trapped and further isolated IIa, IIb, and IIc reveal global folds similar to that of the native protein, including a native-like canonical inhibitory loop. Enzyme kinetics shows that both IIa and IIc are inhibitory-active, which may substantially reduce proteolysis of LDTI during its folding process. The results reported show that the kinetics of the folding reaction is modulated by the specific structural properties of the intermediates and together provide insights into the interdependence of conformational folding and the assembly of native disulfides during oxidative folding. PMID:19820233

  18. Cycling of Dense Core Vesicles Involved in Somatic Exocytosis of Serotonin by Leech Neurons

    PubMed Central

    Trueta, Citlali; Kuffler, Damien P.; De-Miguel, Francisco F.

    2012-01-01

    We studied the cycling of dense core vesicles producing somatic exocytosis of serotonin. Our experiments were made using electron microscopy and vesicle staining with fluorescent dye FM1-43 in Retzius neurons of the leech, which secrete serotonin from clusters of dense core vesicles in a frequency-dependent manner. Electron micrographs of neurons at rest or after 1 Hz stimulation showed two pools of dense core vesicles. A perinuclear pool near Golgi apparatuses, from which vesicles apparently form, and a peripheral pool with vesicle clusters at a distance from the plasma membrane. By contrast, after 20 Hz electrical stimulation 47% of the vesicle clusters were apposed to the plasma membrane, with some omega exocytosis structures. Dense core and small clear vesicles apparently originating from endocytosis were incorporated in multivesicular bodies. In another series of experiments, neurons were stimulated at 20 Hz while bathed in a solution containing peroxidase. Electron micrographs of these neurons contained gold particles coupled to anti-peroxidase antibodies in dense core vesicles and multivesicular bodies located near the plasma membrane. Cultured neurons depolarized with high potassium in the presence of FM1-43 displayed superficial fluorescent spots, each reflecting a vesicle cluster. A partial bleaching of the spots followed by another depolarization in the presence of FM1-43 produced restaining of some spots, other spots disappeared, some remained without restaining and new spots were formed. Several hours after electrical stimulation the FM1-43 spots accumulated at the center of the somata. This correlated with electron micrographs of multivesicular bodies releasing their contents near Golgi apparatuses. Our results suggest that dense core vesicle cycling related to somatic serotonin release involves two steps: the production of clear vesicles and multivesicular bodies after exocytosis, and the formation of new dense core vesicles in the perinuclear

  19. Phase relationships between segmentally organized oscillators in the leech heartbeat pattern generating network.

    PubMed

    Masino, Mark A; Calabrese, Ronald L

    2002-03-01

    Motor pattern generating networks that produce segmentally distributed motor outflow are often portrayed as a series of coupled segmental oscillators that produce a regular progression (constant phase differences) in their rhythmic activity. The leech heartbeat central pattern generator is paced by a core timing network, which consists of two coupled segmental oscillators in segmental ganglia 3 and 4. The segmental oscillators comprise paired mutually inhibitory oscillator interneurons and the processes of intersegmental coordinating interneurons. As a first step in understanding the coordination of segmental motor outflow by this pattern generator, we describe the functional synaptic interactions, and activity and phase relationships of the heart interneurons of the timing network, in isolated nerve cord preparations. In the timing network, most (approximately 75%) of the coordinating interneuron action potentials were generated at a primary spike initiation site located in ganglion 4 (G4). A secondary spike initiation site in ganglion 3 (G3) became active in the absence of activity at the primary site. Generally, the secondary site was characterized by a reluctance to burst and a lower spike frequency, when compared with the primary site. Oscillator interneurons in G3 inhibited spike activity at both initiation sites, whereas oscillator interneurons in G4 inhibited spike activity only at the primary initiation site. This asymmetry in the control of spike activity in the coordinating interneurons may account for the observation that the phase of the coordinating interneurons is more tightly linked to the G3 than G4 oscillator interneurons. The cycle period of the timing network and the phase difference between the ipsilateral G3 and G4 oscillator interneurons were regular within individual preparations, but varied among preparations. This variation in phase differences observed across preparations implies that modulated intrinsic membrane and synaptic properties

  20. Regional differences in BMP-dependence of dorsoventral patterning in the leech Helobdella

    PubMed Central

    Kuo, Dian-Han; Shankland, Marty; Weisblat, David A.

    2012-01-01

    In the leech Helobdella, the ectoderm exhibits a high degree of morphological homonomy between body segments, but pattern elements in lateral ectoderm arise via distinct cell lineages in the segments of the rostral and midbody regions. In each of the four rostral segments, a complete set of ventrolateral (O fate) and dorsolateral (P fate) ectodermal pattern elements arises from a single founder cell, op. In the 28 midbody and caudal segments, however, there are two initially indeterminate o/p founder cells; the more dorsal of these is induced to adopt the P fate by BMP5-8 emanating from the dorsalmost ectoderm, while the more ventral cell assumes the O fate. Previous work has suggested that the dorsoventral patterning of O and P fates differs in the rostral region, but the role of BMP signaling in those segments has not been investigated. We show here that suppression of dorsal BMP5-8 signaling (which effects a P-to-O fate change in the midbody) has no effect on the patterning of O and P fates in the rostral region. Furthermore, ectopic expression of BMP5-8 in the ventral ectoderm (which induces an O-to-P fate change in the midbody) has no effect in the rostral region. Finally, expression of a dominant-negative BMP receptor (which induces a P-to-O fate change in the midbody) fails to affect O/P patterning in the rostral region. Thus, the rostral segments appear to use some mechanism other than BMP signaling to pattern O and P cell fates along the dorsoventral axis. From a mechanistic standpoint, the OP lineage of the rostral segments and the O-P equivalence group of the midbody and caudal segments constitute distinct developmental modules that rely to differing degrees on positional cues from surrounding ectoderm in order to specify homonomous cell fates. PMID:22641012

  1. Dopamine activates the motor pattern for crawling in the medicinal leech.

    PubMed

    Puhl, Joshua G; Mesce, Karen A

    2008-04-16

    Locomotion in segmented animals is thought to be based on the coupling of "unit burst generators," but the biological nature of the unit burst generator has been revealed in only a few animal systems. We determined that dopamine (DA), a universal modulator of motor activity, is sufficient to activate fictive crawling in the medicinal leech, and can exert its actions within the smallest division of the animal's CNS, the segmental ganglion. In the entire isolated nerve cord or in the single ganglion, DA induced slow antiphasic bursting (approximately 15 s period) of motoneurons known to participate in the two-step elongation-contraction cycle underlying crawling behavior. During each cycle, the dorsal (DE-3) and ventral (VE-4) longitudinal excitor motoneurons fired approximately 180 degrees out of phase from the ventrolateral circular excitor motoneuron (CV), which marks the elongation phase. In many isolated whole nerve cords, DE-3 bursting progressed in an anterior to posterior direction with intersegmental phase delays appropriate for crawling. In the single ganglion, the dorsal (DI-1) and ventral (VI-2) inhibitory longitudinal motoneurons fired out of phase with each DE-3 burst, further confirming that the crawl unit burst generator exists in the single ganglion. All isolated ganglia of the CNS were competent to produce DA-induced robust fictive crawling, which typically lasted uninterrupted for 5-15 min. A quantitative analysis indicated that DA-induced crawling was not significantly different from electrically evoked or spontaneous crawling. We conclude that DA is sufficient to activate the full crawl motor program and that the kernel for crawling resides within each segmental ganglion.

  2. Systematics of the freshwater leech genus Hirudinaria Whitman, 1886 (Arhynchobdellida, Hirudinidae) from northeastern Thailand

    PubMed Central

    Tubtimon, Jaruwan; Jeratthitikul, Ekgachai; Sutcharit, Chirasak; Kongim, Bangon; Panha, Somsak

    2014-01-01

    Abstract In total, 435 specimens of the Southeast Asian freshwater leech species within the Hirudinidae family were collected from 17 locations of various types of aquatic habitats in northeastern Thailand. They were all morphologically placed within the genus Hirudinaria Whitman, 1886 and there were three distinct species: the common Hirudinaria manillensis, 78.2% of all collected specimens and at all 17 locations, Hirudinaria javanica at 20.3% of collected samples and from five locations and a rarer unidentified morphospecies (Hirudinaria sp.) with six samples from only two locations. The karyotypes of these three species were examined across their range in this study area for 38, 11 and 6 adult specimens of Hirudinaria manillensis, Hirudinaria javanica and Hirudinaria sp., respectively. This revealed different chromosome numbers among all three species, with Hirudinaria javanica having n = 13, 2n = 26, Hirudinaria manillensis lacked one small chromosome pair with n = 12, 2n = 24, and the unknown Hirudinaria sp. differed from any known Hirudinaria karyotypes in exhibiting a higher chromosome number (n = 14, 2n = 28) and a gradual change in size from large to small chromosomes. This suggests that the unknown Hirudinaria sp. is a new biological species. However, phylogenetic analysis based upon a 658 bp fragment of the cytochrome oxidase subunit I gene placed this unknown morphospecies within the Hirudinaria manillensis clade, perhaps then suggesting a recent sympatric speciation, although this requires further confirmation. Regardless, the chromosomes of all three species were asymmetric, most with telocentric elements. A distinct bi-armed chromosome marker was present on the first chromosome pair in Hirudinaria javanica, whilst it was on pairs 1, 2, 3 and 5 in Hirudinaria manillensis, and on pairs 3 and 5 for the unknown Hirudinaria sp. PMID:25493052

  3. Hm-MyD88 and Hm-SARM: Two key regulators of the neuroimmune system and neural repair in the medicinal leech

    PubMed Central

    Rodet, F.; Tasiemski, A.; Boidin-Wichlacz, C.; Van Camp, C.; Vuillaume, C.; Slomianny, C.; Salzet, M.

    2015-01-01

    Unlike mammals, the CNS of the medicinal leech can regenerate damaged neurites, thus restoring neural functions after lesion. We previously demonstrated that the injured leech nerve cord is able to mount an immune response promoting the regenerative processes. Indeed neurons and microglia express sensing receptors like Hm-TLR1, a leech TLR ortholog, associated with chemokine release in response to a septic challenge or lesion. To gain insights into the TLR signaling pathways involved during these neuroimmune responses, members of the MyD88 family were investigated. In the present study, we report the characterization of Hm-MyD88 and Hm-SARM. The expression of their encoding gene was strongly regulated in leech CNS not only upon immune challenge but also during CNS repair, suggesting their involvement in both processes. This work also showed for the first time that differentiated neurons of the CNS could respond to LPS through a MyD88-dependent signalling pathway, while in mammals, studies describing the direct effect of LPS on neurons and the outcomes of such treatment are scarce and controversial. In the present study, we established that this PAMP induced the relocalization of Hm-MyD88 in isolated neurons. PMID:25880897

  4. Hm-MyD88 and Hm-SARM: two key regulators of the neuroimmune system and neural repair in the medicinal leech.

    PubMed

    Rodet, F; Tasiemski, A; Boidin-Wichlacz, C; Van Camp, C; Vuillaume, C; Slomianny, C; Salzet, M

    2015-04-16

    Unlike mammals, the CNS of the medicinal leech can regenerate damaged neurites, thus restoring neural functions after lesion. We previously demonstrated that the injured leech nerve cord is able to mount an immune response promoting the regenerative processes. Indeed neurons and microglia express sensing receptors like Hm-TLR1, a leech TLR ortholog, associated with chemokine release in response to a septic challenge or lesion. To gain insights into the TLR signaling pathways involved during these neuroimmune responses, members of the MyD88 family were investigated. In the present study, we report the characterization of Hm-MyD88 and Hm-SARM. The expression of their encoding gene was strongly regulated in leech CNS not only upon immune challenge but also during CNS repair, suggesting their involvement in both processes. This work also showed for the first time that differentiated neurons of the CNS could respond to LPS through a MyD88-dependent signalling pathway, while in mammals, studies describing the direct effect of LPS on neurons and the outcomes of such treatment are scarce and controversial. In the present study, we established that this PAMP induced the relocalization of Hm-MyD88 in isolated neurons.

  5. Host specificity in Metamera sillasenorum, n. sp., a gregarine parasite of the leech Helobdella triserialis with notes on transmission dynamics.

    PubMed

    Wise, M R; Janovy, J; Wise, J C

    2000-06-01

    Eugregarines of the suborder Septatorina are apicomplexan parasites that are found mainly in arthropods. Some exceptions are species in the Metameridae that contains the only 5 septate gregarines recorded from annelids. The type genus is Metamera Duke, 1910 with 2 species, Metamera schubergi Duke, 1910, in European Glossiphonia complanata, and Metamera reynoldsi Jones, 1943, from North American G. complanata. Over the summers of 1995-1998, in Keith County, Nebraska, septate gregarines were found in the glossiphoniid leech Helobdella triserialis. The gregarines were determined to be a new species of Metamera, herein named Metamera sillasenorum. Measurements of size and body proportions of over 600 gregarines and 50 oocysts showed differences from measurements of M. schubergi and M. reynoldsi, and secondary septa in the deutomerite were rarely observed. Field observations indicated that M. sillasenorum is probably host specific. In the laboratory, leeches also exhibited strong feeding preferences; e.g., H. triserialis and G. complanata consumed only snails, whereas Helobdella stagnalis consumed only oligochaetes. Infection experiments demonstrated that freshwater snails ingest the oocysts and are required as mechanical vectors. Oocysts were passed unaltered through the snails' intestines. Glossiphonia complanata did not become infected regardless of heavy exposure to oocysts, although only 5 G. complanata were used in the experiments. The results show that host specificity of M. sillasenorum is most likely due to a combination of host-feeding habits and host-parasite compatibility.

  6. Comparison of the effects of cumene hydroperoxide and hydrogen peroxide on Retzius nerve cells of the leech Haemopis sanguisuga.

    PubMed

    Jovanovic, Zorica; Jovanovic, Svetlana

    2013-01-01

    Oxidative stress and the production of reactive oxygen species are known to play a major role in neuronal cell damage, but the exact mechanisms responsible for neuronal injury and death remain uncertain. In the present study, we examined the effects of oxidative stress on spontaneous spike activity and depolarizing outward potassium current by exposing the Retzius neurons of the leech to cumene hydroperoxide (CHP) and hydrogen peroxide (H(2)O(2)), the oxidants commonly used to examine oxidative mechanisms mediating cell death. We observed that relatively low concentrations of CHP (0.25, 1, and 1.5 mM) led to a marked prolongation of spontaneous repetitive activity. The prolonged action potentials showed an initial, spike-like depolarization followed by a plateau phase. In contrast, H(2)O(2) at the same and much higher concentrations (0.25 to 5 mM) did not significantly change the duration of spontaneous spike potentials of leech Retzius nerve cells (LRNCs). In the voltage clamp experiments, calcium-activated outward potassium currents, needed for the repolarization of the action potential, were suppressed with CHP, but not with H(2)O(2). The present findings indicate that CHP is a more potent oxidant and neurotoxin than H(2)O(2) and that the effect of CHP on the electrophysiological properties of LRNCs may be due to the inhibition of the potassium channels.

  7. Population variation and individual maximum size in two leech populations: energy extraction from cannibalism or niche widening?

    PubMed

    Persson, Lennart; Elliott, J Malcolm

    2013-05-01

    The theory of cannibal dynamics predicts a link between population dynamics and individual life history. In particular, increased individual growth has, in both modeling and empirical studies, been shown to result from a destabilization of population dynamics. We used data from a long-term study of the dynamics of two leech (Erpobdella octoculata) populations to test the hypothesis that maximum size should be higher in a cycling population; one of the study populations exhibited a delayed feedback cycle while the other population showed no sign of cyclicity. A hump-shaped relationship between individual mass of 1-year-old leeches and offspring density the previous year was present in both populations. As predicted from the theory, the maximum mass of individuals was much larger in the fluctuating population. In contrast to predictions, the higher growth rate was not related to energy extraction from cannibalism. Instead, the higher individual mass is suggested to be due to increased availability of resources due to a niche widening with increased individual body mass. The larger individual mass in the fluctuating population was related to a stronger correlation between the densities of 1-year-old individuals and 2-year-old individuals the following year in this population. Although cannibalism was the major mechanism regulating population dynamics, its importance was negligible in terms of providing cannibalizing individuals with energy subsequently increasing their fecundity. Instead, the study identifies a need for theoretical and empirical studies on the largely unstudied interplay between ontogenetic niche shifts and cannibalistic population dynamics.

  8. The present state of the leech fauna (Annelida, Hirudinea) in the Upper Irtysh cascade of water reservoirs

    PubMed Central

    Fedorova, Lyudmila I.; Kaygorodova, Irina A.

    2016-01-01

    Abstract Hirudinea is a small and ecologically important group of aquatic organisms. However, up to date, the leech fauna of Kazakhstan is poorly studied. The presence of large under-collected areas, such as the Upper Irtysh basin, makes biodiversity studies concerning these invertebrates from Kazakhstan relevant. In this paper, the latest information on species diversity of the freshwater hirudofauna of the Upper Irtysh cascade of water reservoirs, the Kazakhstan part of Irtysh River, is presented. It includes 10 free-living and parasitic species, of which 7 and 9 inhabit the Shulbinsk and the Bukhtarma reservoirs, respectively. These species belong to 2 orders, 3 families and 6 genera. The faunal list highlights four potentially new morphological species (Alboglossiphonia sp., Erpobdella sp., Piscicola sp. 1 and Piscicola sp. 2). Besides them, another three species Erpobdella vilnensis, Helobdella stagnalis and Theromyzon tessulatum recorded for the first time in the area. The exact systematic position is stated for all leech taxa. Each species from the list accompanied with information on taxonomic synonymy, data on its geographic distribution, and brief summary of morphological and ecological characteristics. PMID:27408572

  9. Solubilization, molecular forms, purification and substrate specificity of two acetylcholinesterases in the medicinal leech (Hirudo medicinalis).

    PubMed Central

    Talesa, V; Grauso, M; Giovannini, E; Rosi, G; Toutant, J P

    1995-01-01

    Two acetylcholinesterases (AChE) differing in substrate and inhibitor specificities have been characterized in the medical leech (Hirudo medicinalis). A 'spontaneously-soluble' portion of AChE activity (SS-AChE) was recovered from haemolymph and from tissues dilacerated in low-salt buffer. A second portion of AChE activity was obtained after extraction of tissues in low-salt buffer alone or containing 1% Triton X-100 [detergent-soluble (DS-) AChE). Both enzymes were purified to homogeneity by affinity chromatography on edrophonium- and concanavalin A-Sepharose columns. Denaturing SDS/PAGE under reducing conditions gave one band at 30 kDa for purified SS-AChE and 66 kDa for DS-AChE. Sephadex G-200 chromatography indicated a molecular mass of 66 kDa for native SS-AChE and of 130 kDa for DS-AChE. SS-AChE showed a single peak sedimenting at 5.0 S in sucrose gradients with or without Triton X-100, suggesting that it was a hydrophylic monomer (G1). DS-AChE sedimented as a single 6.1-6.5 S peak in the presence of Triton X-100 and aggregated in the absence of detergent. A treatment with phosphatidylinositol-specific phospholipase C suppressed aggregation and gave a 7 S peak. DS-AChE was thus an amphiphilic glycolipid-anchored dimer. Substrate specificities were studied using p-nitrophenyl esters (acetate, propionate and butyrate) and corresponding thiocholine esters as substrates. SS-AChE displayed only limited variations in Km values with charged and uncharged substrates, suggesting a reduced influence of electrostatic interactions in the enzyme substrate affinity. By contrast, DS-AChE displayed higher Km values with uncharged than with charged substrates. SS-AChE was more sensitive to eserine and di-isopropyl fluorophosphate (IC50 5 x 10(-8) and 10(-8) M respectively) than DS-AChE (5 x 10(-7) and 5 x 10(-5) M. Images Figure 2 Figure 3 Figure 4 PMID:7702560

  10. Coding and adaptation during mechanical stimulation in the leech nervous system.

    PubMed

    Pinato, G; Torre, V

    2000-12-15

    The experiments described here were designed to characterise sensory coding and adaptation during mechanical stimulation in the leech (Hirudo medicinalis). A chain of three ganglia and a segment of the body wall connected to the central ganglion were used. Eight extracellular suction pipettes and one or two intracellular electrodes were used to record action potentials from all mechanosensory neurones of the three ganglia. When the skin of the body wall was briefly touched with a filament exerting a force of about 2 mN, touch (T) cells in the central ganglion, but also those in adjacent ganglia (i.e. anterior and posterior), fired one or two action potentials. However, the threshold for action potential initiation was lower for T cells in the central ganglion than for those in adjacent ganglia. The timing of the first evoked action potential in a T cell was very reproducible with a jitter often lower than 100 us. Action potentials in T cells were not significantly correlated. When the force exerted by the filament was increased above 20 mN, pressure (P) cells in the central and neighbouring ganglia fired action potentials. Action potentials in P cells usually followed those evoked in T cells with a delay of about 20 ms and had a larger jitter of 0.5-10 ms. With stronger stimulations exceeding 50 mN, noxious (N) cells also fired action potentials. With such stimulations the majority of mechanosensory neurones in the three ganglia fired action potentials. The spatial properties of the whole receptive field of the mechanosensory neurones were explored by touching different parts of the skin. When the mechanical stimulation was applied for a longer time, i.e. 1 s, only P cells in the central ganglion continued to fire action potentials. P cells in neighbouring ganglia fully adapted after firing two or three action potentials.P cells in adjacent ganglia, having fully adapted to a steady mechanical stimulation of one part of the skin, fired action potentials following

  11. The LEECH Exoplanet Imaging Survey. Further constraints on the planet architecture of the HR 8799 system

    NASA Astrophysics Data System (ADS)

    Maire, A.-L.; Skemer, A. J.; Hinz, P. M.; Desidera, S.; Esposito, S.; Gratton, R.; Marzari, F.; Skrutskie, M. F.; Biller, B. A.; Defrère, D.; Bailey, V. P.; Leisenring, J. M.; Apai, D.; Bonnefoy, M.; Brandner, W.; Buenzli, E.; Claudi, R. U.; Close, L. M.; Crepp, J. R.; De Rosa, R. J.; Eisner, J. A.; Fortney, J. J.; Henning, T.; Hofmann, K.-H.; Kopytova, T. G.; Males, J. R.; Mesa, D.; Morzinski, K. M.; Oza, A.; Patience, J.; Pinna, E.; Rajan, A.; Schertl, D.; Schlieder, J. E.; Su, K. Y. L.; Vaz, A.; Ward-Duong, K.; Weigelt, G.; Woodward, C. E.

    2015-04-01

    Context. Astrometric monitoring of directly imaged exoplanets allows the study of their orbital parameters and system architectures. Because most directly imaged planets have long orbital periods (>20 AU), accurate astrometry is challenging when based on data acquired on timescales of a few years and usually with different instruments. The LMIRCam camera on the Large Binocular Telescope is being used for the LBT Exozodi Exoplanet Common Hunt (LEECH) survey to search for and characterize young and adolescent exoplanets in L' band (3.8 μm), including their system architectures. Aims: We first aim to provide a good astrometric calibration of LMIRCam. Then, we derive new astrometry, test the predictions of the orbital model of 8:4:2:1 mean motion resonance proposed for the system, and perform new orbital fitting of the HR 8799 bcde planets. We also present deep limits on a putative fifth planet inside the known planets. Methods: We use observations of HR 8799 and the Θ1 Ori C field obtained during the same run in October 2013. Results: We first characterize the distortion of LMIRCam. We determine a platescale and a true north orientation for the images of 10.707 ± 0.012 mas/pix and -0.430 ± 0.076°, respectively. The errors on the platescale and true north orientation translate into astrometric accuracies at a separation of 1'' of 1.1 mas and 1.3 mas, respectively. The measurements for all planets agree within 3σ with a predicted ephemeris. The orbital fitting based on the new astrometric measurements favors an architecture for the planetary system based on 8:4:2:1 mean motion resonance. The detection limits allow us to exclude a fifth planet slightly brighter or more massive than HR 8799 b at the location of the 2:1 resonance with HR 8799 e (~9.5 AU) and about twice as bright as HR 8799 cde at the location of the 3:1 resonance with HR 8799 e (~7.5 AU). The LBT is an international collaboration among institutions in the United States, Italy, and Germany. LBT

  12. Effect of conduction block at axon bifurcations on synaptic transmission to different postsynaptic neurones in the leech.

    PubMed Central

    Gu, X N

    1991-01-01

    1. The cutaneous receptive field of the medial pressure (mP) sensory neurone in the leech has been examined. The cell has one major receptive field and an anterior and a posterior minor receptive field, principally on lateral and dorsal skin. The two minor receptive fields are contiguous with the major receptive field and are innervated by fine anterior and posterior axons, but there is no overlap between major and minor receptive fields. 2. At low frequencies of stimulation of the minor receptive fields, conduction block takes place in the mP cell at the central branch point within the leech ganglion. 3. The mP cell synapses directly with many other cells in the leech ganglion, including the anterior pagoda (AP) cell, longitudinal (L) motoneurone and the annulus erector (AE) motoneurone, which were studied as a group of postsynaptic neurones. Conduction block in the mP cell affects its synaptic transmission to all three postsynaptic neurones, but the effect can be different in different postsynaptic neurones. Block at the central branch point for an impulse travelling along the anterior axon reduces transmission to the AE cell much more than to the AP or L cells, while block at the central branch for an impulse travelling along the posterior axon has the reverse effect. 4. The distribution of functional connections of the branches of the mP cell with each postsynaptic cell was studied. For this analysis, branches of the mP cell were selectively silenced either during conduction block or by laser microsurgery. Generally, nearly all of the functional connections with the L and AP cell are made by anterior branches of the mP cell while the connection with the AE cell was primarily made by posterior branches of the mP cell. 5. The possible sites of contact between the mP cell and postsynaptic cells were determined by injecting separate markers into the mP cell and a postsynaptic cell. In confirmation of physiology, the mP cell's posterior branches had few, if any

  13. Interaction of HmC1q with leech microglial cells: involvement of C1qBP-related molecule in the induction of cell chemotaxis

    PubMed Central

    2012-01-01

    Background In invertebrates, the medicinal leech is considered to be an interesting and appropriate model to study neuroimmune mechanisms. Indeed, this non-vertebrate animal can restore normal function of its central nervous system (CNS) after injury. Microglia accumulation at the damage site has been shown to be required for axon sprouting and for efficient regeneration. We characterized HmC1q as a novel chemotactic factor for leech microglial cell recruitment. In mammals, a C1q-binding protein (C1qBP alias gC1qR), which interacts with the globular head of C1q, has been reported to participate in C1q-mediated chemotaxis of blood immune cells. In this study, we evaluated the chemotactic activities of a recombinant form of HmC1q and its interaction with a newly characterized leech C1qBP that acts as its potential ligand. Methods Recombinant HmC1q (rHmC1q) was produced in the yeast Pichia pastoris. Chemotaxis assays were performed to investigate rHmC1q-dependent microglia migration. The involvement of a C1qBP-related molecule in this chemotaxis mechanism was assessed by flow cytometry and with affinity purification experiments. The cellular localization of C1qBP mRNA and protein in leech was investigated using immunohistochemistry and in situ hybridization techniques. Results rHmC1q-stimulated microglia migrate in a dose-dependent manner. This rHmC1q-induced chemotaxis was reduced when cells were preincubated with either anti-HmC1q or anti-human C1qBP antibodies. A C1qBP-related molecule was characterized in leech microglia. Conclusions A previous study showed that recruitment of microglia is observed after HmC1q release at the cut end of axons. Here, we demonstrate that rHmC1q-dependent chemotaxis might be driven via a HmC1q-binding protein located on the microglial cell surface. Taken together, these results highlight the importance of the interaction between C1q and C1qBP in microglial activation leading to nerve repair in the medicinal leech. PMID:22356764

  14. Expression and characterization of the N-terminal half of antistasin, an anticoagulant protein derived from the leech Haementeria officinalis.

    PubMed

    Palladino, L O; Tung, J S; Dunwiddie, C; Alves, K; Lenny, A B; Przysiecki, C; Lehman, D; Nutt, E; Cuca, G C; Law, S W

    1991-02-01

    Antistasin, a 15-kDa anticoagulant protein isolated from the salivary glands of the Mexican leech Haementeria officinalis, has been shown to be a potent inhibitor of factor Xa in the blood coagulation cascade. Antistasin possesses a twofold internal homology between the N- and C-terminal halves of the molecule, suggesting a gene duplication event in the evolution of the antistasin gene. This structural feature also suggests that either or both halves of the protein may possess biological activity if expressed as separate domains. Because the N-terminal domain contains a factor Xa P1-reactive site, we chose to express this domain in an insect cell baculovirus expression system. Characterization of this recombinant half antistasin molecule reveals that the N-terminal domain inhibits factor Xa in vitro, with a K(i) of 1.7 nM.

  15. The neurotoxic effects of hydrogen peroxide and copper in Retzius nerve cells of the leech Haemopis sanguisuga

    PubMed Central

    Jovanovic, Zorica D.; Stanojevic, Marija B.; Nedeljkov, Vladimir B.

    2016-01-01

    ABSTRACT Oxidative stress and the generation of reactive oxygen species (ROS) play an important role in cellular damage. Electrophysiological analyses have shown that membrane transport proteins are susceptible to ROS. In the present study, oxidative stress was induced in Retzius nerve cells of the leech Haemopis sanguisuga by bath application of 1 mM of hydrogen peroxide (H2O2) and 0.02 mM of copper (Cu) for 20 min. The H2O2/Cu(II) produced considerable changes in the electrical properties of the Retzius nerve cells. Intracellular recording of the resting membrane potential revealed that the neuronal membrane was depolarized in the presence of H2O2/Cu(II). We found that the amplitude of action potentials decreased, while the duration augmented in a progressive way along the drug exposure time. The combined application of H2O2 and Cu(II) caused an initial excitation followed by depression of the spontaneous electrical activity. Voltage-clamp recordings revealed a second effect of the oxidant, a powerful inhibition of the outward potassium channels responsible for the repolarization of action potentials. The neurotoxic effect of H2O2/Cu(II) on the spontaneous spike electrogenesis and outward K+ current of Retzius nerve cells was reduced in the presence of hydroxyl radical scavengers, dimethylthiourea and dimethyl sulfoxide, but not mannitol. This study provides evidence for the oxidative modification of outward potassium channels in Retzius nerve cells. The oxidative mechanism of the H2O2/Cu(II) system action on the electrical properties of Retzius neurons proposed in this study might have a wider significance, referring not only to leeches but also to mammalian neurons. PMID:26935393

  16. Symbiosis of Aeromonas veronii Biovar sobria and Hirudo medicinalis, the Medicinal Leech: a Novel Model for Digestive Tract Associations

    PubMed Central

    Graf, Joerg

    1999-01-01

    Hirudo medicinalis, the medicinal leech, is applied postoperatively in modern medicine. Infections by Aeromonas occur in up to 20% of patients unless a preemptive antibiotic treatment is administered. The associated infections demonstrate the need for a better understanding of the digestive tract flora of H. medicinalis. Early studies reported the presence of a single bacterial species in the digestive tract and suggested that these bacteria were endosymbionts contributing to the digestion of blood. In this study, we cultivated bacteria from the digestive tract and characterized them biochemically. The biochemical test results identified the isolates as Aeromonas veronii biovar sobria. This species identification was supported by sequence comparison of a variable region of the genes coding for 16S rRNA. In a colonization assay, a rifampin-resistant derivative of a symbiotic isolate was fed in a blood meal to H. medicinalis. The strain colonized the digestive tract rapidly and reached a concentration similar to that of the native bacterial flora. For the first 12 h, the in vivo doubling time was 1.2 h at 23°C. After 12 h, at a density of 5 × 107 CFU/ml, the increase in viable counts ceased, suggesting a dramatic reduction in the bacterial growth rate. Two human fecal isolates, identified as Aeromonas hydrophila and A. veronii biovar sobria, were also able to colonize the digestive tract. These data demonstrate that the main culturable bacterium in the crop of H. medicinalis is A. veronii biovar sobria and that the medicinal leech can be used as a model for digestive tract association of Aeromonas species. PMID:9864188

  17. Mechanism of ammonia excretion in the freshwater leech Nephelopsis obscura: characterization of a primitive Rh protein and effects of high environmental ammonia

    PubMed Central

    Quijada-Rodriguez, Alex R.; Treberg, Jason R.

    2015-01-01

    Remarkably little is known about nitrogenous excretion in freshwater invertebrates. In the current study, the nitrogen excretion mechanism in the carnivorous ribbon leech, Nephelopsis obscura, was investigated. Excretion experiments showed that the ribbon leech is ammonotelic, excreting 166.0 ± 8.6 nmol·grams fresh weight (gFW)−1·h−1 ammonia and 14.7 ± 1.9 nmol·gFW−1·h−1 urea. Exposure to high and low pH hampered and enhanced, respectively, ammonia excretion rates, indicating an acid-linked ammonia trapping mechanism across the skin epithelia. Accordingly, compared with body tissues, the skin exhibited elevated mRNA expression levels of a newly identified Rhesus protein and at least in tendency the Na+/K+-ATPase. Pharmacological experiments and enzyme assays suggested an ammonia excretion mechanism that involves the V-ATPase, Na+/K+-ATPase, and carbonic anhydrase, but not necessarily a functional microtubule system. Most importantly, functional expression studies of the identified Rh protein cloned from leech skin tissue revealed an ammonia transport capability of this protein when expressed in yeast. The leech Rh-ammonia transporter (NoRhp) is a member of the primitive Rh protein family, which is a sister group to the common ancestor of vertebrate ammonia-transporting Rh proteins. Exposure to high environmental ammonia (HEA) caused a new adjustment of body ammonia, accompanied with a decrease in NoRhp and Na+/K+-ATPase mRNA levels, but unaltered ammonia excretion rates. To our knowledge, this is only the second comprehensive study regarding the ammonia excretion mechanisms in a freshwater invertebrate, but our results show that basic processes of ammonia excretion appear to also be comparable to those found in freshwater fish, suggesting an early evolution of ionoregulatory mechanisms in freshwater organisms. PMID:26180186

  18. Field evaluation of deet, Repel Care, and three plant based essential oil repellents against mosquitoes, black flies (Diptera: Simuliidae) and land leeches (Arhynchobdellida: Haemadipsidae) in Thailand.

    PubMed

    Tawatsin, Apiwat; Thavara, Usavadee; Chansang, Uruyakorn; Chavalittumrong, Pranee; Boonruad, Thidarat; Wongsinkongman, Prapai; Bansidhi, Jaree; Mulla, Mir S

    2006-06-01

    Diethyl methyl benzamide, or deet, a commercial plant-based repellent (Repel Care), and essential ils from 3 species of plants (finger root rhizomes, guava leaves, and turmeric rhizomes), steam distillated and formulated as insect repellents, were evaluated in the field on human volunteers against hematophagous mosquitoes, black flies, and land leeches in Thailand. Field trials were conducted against wild mosquitoes in Bang Bua Thong District, Nonthaburi Province, and in the Thap Lan National Park Headquarters, Nadee District, Pranchinburi Province; anthroophilic black flies (Diptera: Simuliidae) at the Forestry Fire Control Station in Doi Inthanon National Park, Chomthong district, Chiang Mai Province; and land leeches (Arhynchobdellida: Haemadipsidae) in the Khao Yai National Park, Pak Chong District, Nakhon Ratchasima Province. The 3 experimental plant-based essential oil formulations as well as Repel Care and deet provided complete protection from mosquito landing and biting for up to 9 h (duration of the experiment). Similar results were obtained with the 5 products against black flies, providing 100% protection for 9 h but 96-82% protection after 10 and 11 h posttreatment. The 5 repellent products also provided 100% protection against land leeches for at least 8 h. Thi is the 1st report of repellency of plant-based repellents against black flies and land leeches in Thailand. The identification and availability of inexpensive sources of plant-based oils, i.e., finger root rhizomes, guava leaves, and turmeric rhizomes providing long-lasting repellency against blood-sucking organisms are promising leads into commercial production of relatively safe and effective repellents.

  19. Mechanism of ammonia excretion in the freshwater leech Nephelopsis obscura: characterization of a primitive Rh protein and effects of high environmental ammonia.

    PubMed

    Quijada-Rodriguez, Alex R; Treberg, Jason R; Weihrauch, Dirk

    2015-09-15

    Remarkably little is known about nitrogenous excretion in freshwater invertebrates. In the current study, the nitrogen excretion mechanism in the carnivorous ribbon leech, Nephelopsis obscura, was investigated. Excretion experiments showed that the ribbon leech is ammonotelic, excreting 166.0 ± 8.6 nmol·grams fresh weight (gFW)(-1)·h(-1) ammonia and 14.7 ± 1.9 nmol·gFW(-1)·h(-1) urea. Exposure to high and low pH hampered and enhanced, respectively, ammonia excretion rates, indicating an acid-linked ammonia trapping mechanism across the skin epithelia. Accordingly, compared with body tissues, the skin exhibited elevated mRNA expression levels of a newly identified Rhesus protein and at least in tendency the Na(+)/K(+)-ATPase. Pharmacological experiments and enzyme assays suggested an ammonia excretion mechanism that involves the V-ATPase, Na(+)/K(+)-ATPase, and carbonic anhydrase, but not necessarily a functional microtubule system. Most importantly, functional expression studies of the identified Rh protein cloned from leech skin tissue revealed an ammonia transport capability of this protein when expressed in yeast. The leech Rh-ammonia transporter (NoRhp) is a member of the primitive Rh protein family, which is a sister group to the common ancestor of vertebrate ammonia-transporting Rh proteins. Exposure to high environmental ammonia (HEA) caused a new adjustment of body ammonia, accompanied with a decrease in NoRhp and Na(+)/K(+)-ATPase mRNA levels, but unaltered ammonia excretion rates. To our knowledge, this is only the second comprehensive study regarding the ammonia excretion mechanisms in a freshwater invertebrate, but our results show that basic processes of ammonia excretion appear to also be comparable to those found in freshwater fish, suggesting an early evolution of ionoregulatory mechanisms in freshwater organisms.

  20. Phoretic interaction between the kangaroo leech Marsupiobdella africana (Hirudinea: Glossiphoniidae) and the cape river crab Potamonautes perlatus (Decapoda: Potamonautidae)☆

    PubMed Central

    Badets, Mathieu; Preez, Louis Du

    2013-01-01

    The South African leech Marsupiobdella africana is a temporary ectoparasite of the amphibian Xenopus laevis, has a phoretic association with a freshwater crab Potamonautes perlatus, and exhibits advanced parental care by incubating its offspring in a brood pouch. Because phoretic associations are usually regarded to favor the phoront’s dispersion, its occurrence within the biology of a parasitic species reflects an intimate context of interactions. In addition to phoresy, attachment to the crab may confer other advantages pertaining to offspring development and predator avoidance, dispersion and the parasitic life cycle. Two ponds where amphibian and crab hosts co-occur were sampled twice a month for a period of 1 year. The population dynamics of the leeches and their use of specific microhabitats as attachment sites on the crabs were also investigated. Results indicate a direct relationship between intra-specific variation in the sex ratio among captured crab hosts and the number of leeches recruited over time. The attachments to specific microhabitats on the hard surfaces of the host suggest a proximal proximate anti-predatory strategy. Finally, the importance of oxygen accessibility for the offspring development has been investigated experimentally. Results revealed a remarkable network of interactions linking all partners of this system raising the question as to whether the crabs merely act as a vehicle or play a role within the parasitic life cycle. PMID:24918071

  1. The type II secretion system is essential for erythrocyte lysis and gut colonization by the leech digestive tract symbiont Aeromonas veronii.

    PubMed

    Maltz, Michele; Graf, Joerg

    2011-01-01

    Hemolysin and the type II secretion system (T2SS) have been shown to be important for virulence in many pathogens, but very few studies have shown their importance in beneficial microbes. Here, we investigated the importance of the type II secretion pathway in the beneficial digestive-tract association of Aeromonas veronii and the medicinal leech Hirudo verbana and revealed a critical role for the hemolysis of erythrocytes. A mutant with a miniTn5 insertion in exeM, which is involved in forming the inner membrane platform in the T2SS, was isolated by screening mutants for loss of hemolysis on blood agar plates. A hemolysis assay was used to quantify the mutant's deficiency in lysing sheep erythrocytes and revealed a 99.9% decrease compared to the parent strain. The importance of the T2SS in the colonization of the symbiotic host was assessed. Colonization assays revealed that the T2SS is critical for initial colonization of the leech gut. The defect was tied to the loss of hemolysin production by performing a colonization assay with blood containing lysed erythrocytes. This restored the colonization defect in the mutant. Complementation of the mutant using the promoter region and exeMN revealed that the T2SS is responsible for secreting hemolysin into the extracellular space and that both the T2SS and hemolysin export by the T2SS are critical for initial establishment of A. veronii in the leech gut.

  2. NMR structural characterization and computational predictions of the major intermediate in oxidative folding of leech carboxypeptidase inhibitor.

    PubMed

    Arolas, Joan L; D'Silva, Loyola; Popowicz, Grzegorz M; Aviles, Francesc X; Holak, Tad A; Ventura, Salvador

    2005-08-01

    The III-A intermediate constitutes the major rate-determining step in the oxidative folding of leech carboxypeptidase inhibitor (LCI). In this work, III-A has been directly purified from the folding reaction and structurally characterized by NMR spectroscopy. This species, containing three native disulfides, displays a highly native-like structure; however, it lacks some secondary structure elements, making it more flexible than native LCI. III-A represents a structurally determined example of a disulfide-insecure intermediate; direct oxidation of this species to the fully native protein seems to be restricted by the burial of its two free cysteine residues inside a native-like structure. We also show that theoretical approaches based on topological constraints predict with good accuracy the presence of this folding intermediate. Overall, the derived results suggest that, as it occurs with non-disulfide bonded proteins, native-like interactions between segments of secondary structure rather than the crosslinking of disulfide bonds direct the folding of LCI.

  3. Ionotropic and metabotropic activation of a neuronal chloride channel by serotonin and dopamine in the leech Hirudo medicinalis

    PubMed Central

    Ali, Declan W; Catarsi, Stefano; Drapeau, Pierre

    1998-01-01

    Cl− channels on the pressure-sensitive (P) neuron in the leech are directly activated by synaptic release of serotonin (5-HT) and are indirectly stimulated by the cAMP second messenger pathway, suggesting an unusual dual regulation of the channels. We have investigated the mode of action of 5-HT and dopamine (DA) on a Cl− channel in adult P cells in culture by recording from cell-attached patches.5-HT increased Cl− channel activity only when included in the recording pipette and not when applied in the bath.Pipette or, more effectively, bath application of DA led to an increase in Cl− channel activity. This effect was blocked by the potent and specific dopaminergic (DA1) receptor blocker, SCH-23390.The stimulation by DA, but not by 5-HT, was also blocked by the cAMP-dependent protein kinase A (PKA) inhibitor Rp-cAMP and was mimicked by the membrane-permeant cAMP analogue dibutyryl cAMP (db-cAMP).Our results show that 5-HT directly gates a Cl− channel that is also activated by DA via the cAMP pathway. This study demonstrates that a ligand-gated channel can be independently operated by another transmitter acting via a second messenger pathway. PMID:9547394

  4. Cathepsin L and cystatin B gene expression discriminates immune cœlomic cells in the leech Theromyzon tessulatum

    PubMed Central

    Lefebvre, Christophe; Vandenbulcke, Franck; Bocquet, Béatrice; Tasiemski, Aurélie; Desmons, Annie; Verstraete, Mathilde; Salzet, Michel; Cocquerelle, Claude

    2009-01-01

    Previous studies evidenced that cystatin B-like gene is specifically expressed and induced in large circulating cœlomic cells following bacterial challenge in the leech Theromyzon tessulatum. In order to understand the role of that cysteine proteinase inhibitor during immune response, we investigated the existence of members of cathepsin family. We cloned a cathepsin L-like gene and studied its tissue distribution. Immunohistochemical studies using anti-cathepsin L and anti-cystatin B antibodies and ultrastructural results demonstrated the presence of three distinct cœlomic cell populations, (1) the chloragocytes which were initially defined as large cœlomocytes, (2) the granular amœbocytes, and (3) small cœlomic cells. Among those cells, while chloragocytes contain cystatin B and cathepsin L, granular amœbocytes do only contain cathepsin L and third cell population contains neither cathepsin nor inhibitor. Finally, results evidenced that cathepsin L immunopositive granular amœbocytes are chemoattracted to the site of injury and phagocyte bacteria. PMID:18177937

  5. A dye mixture (Neurobiotin and Alexa 488) reveals extensive dye-coupling among neurons in leeches; physiology confirms the connections.

    PubMed

    Fan, Ruey-Jane; Marin-Burgin, Antonia; French, Kathleen A; Otto Friesen, W

    2005-12-01

    Although the neuronal circuits that generate leech movements have been studied for over 30 years, the list of interneurons (INs) in these circuits remains incomplete. Previous studies showed that some motor neurons (MNs) are electrically coupled to swim-related INs, e.g., rectifying junctions connect IN 28 to MN DI-1 (dorsal inhibitor), so we searched for additional neurons in these behavioral circuits by co-injecting Neurobiotin and Alexa Fluor 488 into segmental MNs DI-1, VI-2, DE-3 and VE-4. The high molecular weight Alexa dye is confined to the injected cell, whereas the smaller Neurobiotin molecules diffuse through gap junctions to reveal electrical coupling. We found that MNs were each dye-coupled to approximately 25 neurons, about half of which are likely to be INs. We also found that (1) dye-coupling was reliably correlated with physiologically confirmed electrical connections, (2) dye-coupling is unidirectional between MNs that are linked by rectifying connections, and (3) there are novel electrical connections between excitatory and inhibitory MNs, e.g. between excitatory MN VE-4 and inhibitory MN DI-1. The INs found in this study provide a pool of novel candidate neurons for future studies of behavioral circuits, including those underlying swimming, crawling, shortening, and bending movements.

  6. D quadrant specification in the leech Helobdella: actomyosin contractility controls the unequal cleavage of the CD blastomere

    PubMed Central

    Lyons, Deirdre C.; Weisblat, David A.

    2009-01-01

    The unequal division of the CD blastomere at second cleavage is critical in establishing the second embryonic axis in the leech Helobdella, as in other unequally cleaving spiralians. When CD divides, the larger D and smaller C blastomeres arise invariantly on the left and right sides of the embryo, respectively. Here we show that stereotyped cellular dynamics, including the formation of an intercellular blastocoel, culminate in a morphological left-right asymmetry in the 2-cell embryo, which precedes cytokinesis and predicts the chirality of the second cleavage. In contrast to the unequal first cleavage, the unequal second cleavage does not result from down-regulation of one centrosome, nor from an asymmetry within the spindle itself. Instead, the unequal cleavage of the CD cell entails a symmetric mitotic apparatus moving and anisotropically growing rightward in an actomyosin-dependent process. Our data reveal that mechanisms controlling the establishment of the D quadrant differ fundamentally even among the monophyletic clitellate annelids. Thus, while the homologous spiral cleavage pattern is highly conserved in this clade, it has diverged significantly at the level of cell biological mechanisms. This combination of operational conservation and mechanistic divergence begins to explain how the spiral cleavage program has remained so refractory to change while, paradoxically, accommodating numerous modifications throughout evolution. PMID:19607823

  7. Enhancing the secretory yields of leech carboxypeptidase inhibitor in Escherichia coli: influence of trigger factor and signal recognition particle.

    PubMed

    Puertas, Juan-Miguel; Nannenga, Brent L; Dornfeld, Kevin T; Betton, Jean-Michel; Baneyx, François

    2010-11-01

    The signal recognition particle (SRP) dependent secretion pathway is as an attractive alternative to Sec-dependent export for the production of disulfide-bonded and/or fast-folding recombinant proteins in the Escherichia coli periplasm. SRP, which shares a ribosomal attachment site with the molecular chaperone trigger factor (TF), recognizes highly hydrophobic signal sequence as they emerge from the ribosome and delivers ribosome nascent chain complexes to FtsY for subsequent cotranslational translocation of target proteins across the SecYEG pore. However, like in the case of Sec-dependent export, secretory yields can be limited by the accumulation of precursor proteins in the cytoplasm. Using leech carboxypeptidase inhibitor (LCI) fused to the SRP-dependent DsbA signal sequence as a model system, we show that a null mutation in the gene encoding TF (Deltatig) or SRP co-expression reduce pre-LCI accumulation by half, and that quantitative export can be achieved by combining the two strategies. Interestingly, enhanced precursor processing did not alter periplasmic LCI levels but increased the amount of protein excreted in the growth medium. All mature LCI was nearly fully active and an 80% increase in productivity was achieved in Deltatig cells alone due to their faster growth. Our results show that competition between SRP and TF can interfere with efficient export of recombinant proteins targeted to the SRP pathway and establish TF-deficient strains and SRP co-expression as a simple solution to improve yields.

  8. A 3-SYNAPSE POSITIVE FEEDBACK LOOP REGULATES THE EXCITABILITY OF AN INTERNEURON CRITICAL FOR SENSITIZATION IN THE LEECH

    PubMed Central

    Crisp, Kevin M.; Muller, Kenneth J.

    2007-01-01

    Sensitization of reflexive shortening in the leech has been linked to serotonin (5-HT)-induced changes in the excitability of a single interneuron, the S cell. This neuron is necessary for sensitization and complete dishabituation of reflexive shortening, during which it contributes to the sensory-motor reflex. The S cell does not contain 5-HT, which is released primarily from the Retzius (R) cells, whose firing enhances S-cell excitability. Here we show that the S cell excites the R cells, mainly via a fast disynaptic pathway in which the first synapse is the electrical junction between the S cell and the coupling interneurons, and the second synapse is a glutamatergic synapse of the coupling interneurons onto the R cells. The S cell-triggered excitatory postsynaptic potential in the R cell diminishes and nearly disappears in elevated concentrations of divalent cations because the coupling interneurons become inexcitable under these conditions. Serotonin released from the R cells feeds back upon the S cell and increases its excitability by activating a 5-HT7-like receptor; 5-methoxytryptamine (5-MeOT; 10 μM) mimics the effects of 5-HT on S cell excitability, and effects of both 5-HT and 5-MeOT are blocked by pimozide (10 μM) and SB-269970 (5 μM). This feedback loop may be critical for the full expression of sensitization of reflexive shortening. PMID:16571760

  9. Ultrastructural study of spermatogenesis and sperm in the African medicinal leech Hirudo troctina Johnson, 1816 (Annelida, Hirudinida).

    PubMed

    Ben Ahmed, Raja; Tekaya, Saïda; Urbisz, Anna Z; Świątek, Piotr

    2015-06-01

    This paper presents the process of spermatogenesis in the leech Hirudo troctina Johnson, 1816 using light, fluorescent and transmission electron microscopy. At the onset of spermatogenesis in testes, the pear-shaped spermatogonia divide mitotically without full cytokinesis and as a result isogenic groups are formed (clusters, clones) with 2, 4, 8, 16, 32, 64, 128 spermatogonia and, finally, 256 primary spermatocytes occur. The final meiotic divisions of spermatocytes give rise to clones with 1024 spermatids. There are hundreds of developing germ-line clones in each testis. In each clone, the male germ cells divide in full synchrony and they are in the same phase of spermatogenesis. During complex spermiogenesis each spermatid becomes a filiform spermatozoon with a helicoid nucleus, which is characterized by the presence of a long acrosome with two regions - anterior and posterior, which are followed by a helicoid nucleus, a midpiece with only one mitochondrion and a long flagellum. Our results were compared to those on other clitellate annelids that have been studied to date, especially to sperm formation in Hirudo medicinalis Linnaeus, 1785. Only minor differences were found in the length and the diameter of different organelles and the number of spermatids in germ-line clones.

  10. Effects of millimeter wave irradiation and equivalent thermal heating on the activity of individual neurons in the leech ganglion

    PubMed Central

    Romanenko, Sergii; Siegel, Peter H.; Wagenaar, Daniel A.

    2014-01-01

    Many of today's radiofrequency-emitting devices in telecommunication, telemedicine, transportation safety, and security/military applications use the millimeter wave (MMW) band (30–300 GHz). To evaluate the biological safety and possible applications of this radiofrequency band for neuroscience and neurology, we have investigated the physiological effects of low-intensity 60-GHz electromagnetic irradiation on individual neurons in the leech midbody ganglia. We applied incident power densities of 1, 2, and 4 mW/cm2 to the whole ganglion for a period of 1 min while recording the action potential with a standard sharp electrode electrophysiology setup. For comparison, the recognized U.S. safe exposure limit is 1 mW/cm2 for 6 min. During the exposure to MMWs and gradual bath heating at a rate of 0.04°C/s (2.4°C/min), the ganglionic neurons exhibited similar dose-dependent hyperpolarization of the plasma membrane and decrease in the action potential amplitude. However, narrowing of the action potential half-width during MMW irradiation at 4 mW/cm2 was 5 times more pronounced compared with that during equivalent bath heating of 0.6°C. Even more dramatic difference in the effects of MMW irradiation and bath heating was noted in the firing rate, which was suppressed at all applied MMW power densities and increased in a dose-dependent manner during gradual bath heating. The mechanism of enhanced narrowing of action potentials and suppressed firing by MMW irradiation, compared with that by gradual bath heating, is hypothesized to involve specific coupling of MMW energy with the neuronal plasma membrane. PMID:25122711

  11. Transcription and protein synthesis inhibitors influence long-term effects of acetyl-l-carnitine on non-associative learning in the leech.

    PubMed

    Traina, Giovanna; Scuri, Rossana

    2015-01-01

    Acetyl-l-carnitine (ALC) is the principal acetyl ester of L-carnitine and it plays an essential role in intermediary metabolism. ALC affects several targets in the nervous system. Along this line of investigation, we analyzed the long-term effects of ALC on elementary nonassociative learning in the swimming induction model of the leech Hirudo medicinalis, in which nociceptive stimulation of the dorsal skin produces a more rapid swim response to a test stimulus (sensitization). In this simplified model a single ALC administration blocked the sensitizing effects of nociceptive stimulation in swim induction showing increasingly long lasting effects. Herein, we have analyzed the long-term effects of ALC on sensitization and dishabituation. Leeches were treated with inhibitors of either transcription or protein synthesis 30 min after the administration of ALC and, subsequently, subjected to noxious stimuli: the animals exhibited a sensitized swimming response 6 days after ALC treatment but not after 2 hours indicating that the long-term suppressive effects of ALC on sensitization/dishabituation needed mRNA and protein synthesis.

  12. Solving a Bloody Mess: B-Vitamin Independent Metabolic Convergence among Gammaproteobacterial Obligate Endosymbionts from Blood-Feeding Arthropods and the Leech Haementeria officinalis.

    PubMed

    Manzano-Marín, Alejandro; Oceguera-Figueroa, Alejandro; Latorre, Amparo; Jiménez-García, Luis F; Moya, Andres

    2015-10-09

    Endosymbiosis is a common phenomenon in nature, especially between bacteria and insects, whose typically unbalanced diets are usually complemented by their obligate endosymbionts. While much interest and focus has been directed toward phloem-feeders like aphids and mealybugs, blood-feeders such as the Lone star tick (Amblyomma americanum), Glossina flies, and the human body louse (Pediculus humanus corporis) depend on obligate endosymbionts which complement their B-vitamin-deficient diets, and thus are required for growth and survival. Glossiphoniid leeches have also been found to harbor distinct endosymbionts housed in specialized organs. Here, we present the genome of the bacterial endosymbiont from Haementeria officinalis, first of a glossiphoniid leech. This as-yet-unnamed endosymbiont belongs to the Gammaproteobacteria, has a pleomorphic shape and is restricted to bacteriocytes. For this bacterial endosymbiont, we propose the name Candidatus Providencia siddallii. This symbiont possesses a highly reduced genome with high A+T content and a reduced set of metabolic capabilities, all of which are common characteristics of ancient obligate endosymbionts of arthropods. Its genome has retained many pathways related to the biosynthesis of B-vitamins, pointing toward a role in supplementing the blood-restricted diet of its host. Through comparative genomics against the endosymbionts of A. americanum, Glossina flies, and P. humanus corporis, we were able to detect a high degree of metabolic convergence among these four very distantly related endosymbiotic bacteria.

  13. Solving a Bloody Mess: B-Vitamin Independent Metabolic Convergence among Gammaproteobacterial Obligate Endosymbionts from Blood-Feeding Arthropods and the Leech Haementeria officinalis

    PubMed Central

    Manzano-Marín, Alejandro; Oceguera-Figueroa, Alejandro; Latorre, Amparo; Jiménez-García, Luis F.; Moya, Andres

    2015-01-01

    Endosymbiosis is a common phenomenon in nature, especially between bacteria and insects, whose typically unbalanced diets are usually complemented by their obligate endosymbionts. While much interest and focus has been directed toward phloem-feeders like aphids and mealybugs, blood-feeders such as the Lone star tick (Amblyomma americanum), Glossina flies, and the human body louse (Pediculus humanus corporis) depend on obligate endosymbionts which complement their B-vitamin-deficient diets, and thus are required for growth and survival. Glossiphoniid leeches have also been found to harbor distinct endosymbionts housed in specialized organs. Here, we present the genome of the bacterial endosymbiont from Haementeria officinalis, first of a glossiphoniid leech. This as-yet-unnamed endosymbiont belongs to the Gammaproteobacteria, has a pleomorphic shape and is restricted to bacteriocytes. For this bacterial endosymbiont, we propose the name Candidatus Providencia siddallii. This symbiont possesses a highly reduced genome with high A+T content and a reduced set of metabolic capabilities, all of which are common characteristics of ancient obligate endosymbionts of arthropods. Its genome has retained many pathways related to the biosynthesis of B-vitamins, pointing toward a role in supplementing the blood-restricted diet of its host. Through comparative genomics against the endosymbionts of A. americanum, Glossina flies, and P. humanus corporis, we were able to detect a high degree of metabolic convergence among these four very distantly related endosymbiotic bacteria. PMID:26454017

  14. The LEECH Exoplanet Imaging Survey: Characterization of the Coldest Directly Imaged Exoplanet, GJ 504 b, and Evidence for Superstellar Metallicity

    NASA Astrophysics Data System (ADS)

    Skemer, Andrew J.; Morley, Caroline V.; Zimmerman, Neil T.; Skrutskie, Michael F.; Leisenring, Jarron; Buenzli, Esther; Bonnefoy, Mickael; Bailey, Vanessa; Hinz, Philip; Defrére, Denis; Esposito, Simone; Apai, Dániel; Biller, Beth; Brandner, Wolfgang; Close, Laird; Crepp, Justin R.; De Rosa, Robert J.; Desidera, Silvano; Eisner, Josh; Fortney, Jonathan; Freedman, Richard; Henning, Thomas; Hofmann, Karl-Heinz; Kopytova, Taisiya; Lupu, Roxana; Maire, Anne-Lise; Males, Jared R.; Marley, Mark; Morzinski, Katie; Oza, Apurva; Patience, Jenny; Rajan, Abhijith; Rieke, George; Schertl, Dieter; Schlieder, Joshua; Stone, Jordan; Su, Kate; Vaz, Amali; Visscher, Channon; Ward-Duong, Kimberly; Weigelt, Gerd; Woodward, Charles E.

    2016-02-01

    As gas giant planets and brown dwarfs radiate away the residual heat from their formation, they cool through a spectral type transition from L to T, which encompasses the dissipation of cloud opacity and the appearance of strong methane absorption. While there are hundreds of known T-type brown dwarfs, the first generation of directly imaged exoplanets were all L type. Recently, Kuzuhara et al. announced the discovery of GJ 504 b, the first T dwarf exoplanet. GJ 504 b provides a unique opportunity to study the atmosphere of a new type of exoplanet with a ˜500 K temperature that bridges the gap between the first directly imaged planets (˜1000 K) and our own solar system's Jupiter (˜130 K). We observed GJ 504 b in three narrow L-band filters (3.71, 3.88, and 4.00 μm), spanning the red end of the broad methane fundamental absorption feature (3.3 μm) as part of the LBTI Exozodi Exoplanet Common Hunt (LEECH) exoplanet imaging survey. By comparing our new photometry and literature photometry with a grid of custom model atmospheres, we were able to fit GJ 504 b's unusual spectral energy distribution for the first time. We find that GJ 504 b is well fit by models with the following parameters: Teff = 544 ± 10 K, g < 600 m s-2, [M/H] = 0.60 ± 0.12, cloud opacity parameter of fsed = 2-5, R = 0.96 ± 0.07 RJup, and log(L) = -6.13 ± 0.03 L⊙, implying a hot start mass of 3-30 Mjup for a conservative age range of 0.1-6.5 Gyr. Of particular interest, our model fits suggest that GJ 504 b has a superstellar metallicity. Since planet formation can create objects with nonstellar metallicities, while binary star formation cannot, this result suggests that GJ 504 b formed like a planet, not like a binary companion. The LBT is an international collaboration among institutions in the United States, Italy, and Germany. LBT Corporation partners are the University of Arizona on behalf of the Arizona university system; Istituto Nazionale di Astrophisica, Italy; LBT

  15. THE LEECH EXOPLANET IMAGING SURVEY: CHARACTERIZATION OF THE COLDEST DIRECTLY IMAGED EXOPLANET, GJ 504 b, AND EVIDENCE FOR SUPERSTELLAR METALLICITY

    SciTech Connect

    Skemer, Andrew J.; Leisenring, Jarron; Bailey, Vanessa; Hinz, Philip; Defrére, Denis; Apai, Dániel; Close, Laird; Eisner, Josh; Morley, Caroline V.; Fortney, Jonathan; Zimmerman, Neil T.; Buenzli, Esther; Bonnefoy, Mickael; Biller, Beth; Brandner, Wolfgang; Skrutskie, Michael F.; Esposito, Simone; Crepp, Justin R.; De Rosa, Robert J.; Desidera, Silvano; and others

    2016-02-01

    As gas giant planets and brown dwarfs radiate away the residual heat from their formation, they cool through a spectral type transition from L to T, which encompasses the dissipation of cloud opacity and the appearance of strong methane absorption. While there are hundreds of known T-type brown dwarfs, the first generation of directly imaged exoplanets were all L type. Recently, Kuzuhara et al. announced the discovery of GJ 504 b, the first T dwarf exoplanet. GJ 504 b provides a unique opportunity to study the atmosphere of a new type of exoplanet with a ∼500 K temperature that bridges the gap between the first directly imaged planets (∼1000 K) and our own solar system's Jupiter (∼130 K). We observed GJ 504 b in three narrow L-band filters (3.71, 3.88, and 4.00 μm), spanning the red end of the broad methane fundamental absorption feature (3.3 μm) as part of the LBTI Exozodi Exoplanet Common Hunt (LEECH) exoplanet imaging survey. By comparing our new photometry and literature photometry with a grid of custom model atmospheres, we were able to fit GJ 504 b's unusual spectral energy distribution for the first time. We find that GJ 504 b is well fit by models with the following parameters: T{sub eff} = 544 ± 10 K, g < 600 m s{sup −2}, [M/H] = 0.60 ± 0.12, cloud opacity parameter of f{sub sed} = 2–5, R = 0.96 ± 0.07 R{sub Jup}, and log(L) = −6.13 ± 0.03 L{sub ⊙}, implying a hot start mass of 3–30 M{sub jup} for a conservative age range of 0.1–6.5 Gyr. Of particular interest, our model fits suggest that GJ 504 b has a superstellar metallicity. Since planet formation can create objects with nonstellar metallicities, while binary star formation cannot, this result suggests that GJ 504 b formed like a planet, not like a binary companion.

  16. Na(+)/K(+) pump interacts with the h-current to control bursting activity in central pattern generator neurons of leeches.

    PubMed

    Kueh, Daniel; Barnett, William H; Cymbalyuk, Gennady S; Calabrese, Ronald L

    2016-09-02

    The dynamics of different ionic currents shape the bursting activity of neurons and networks that control motor output. Despite being ubiquitous in all animal cells, the contribution of the Na(+)/K(+) pump current to such bursting activity has not been well studied. We used monensin, a Na(+)/H(+) antiporter, to examine the role of the pump on the bursting activity of oscillator heart interneurons in leeches. When we stimulated the pump with monensin, the period of these neurons decreased significantly, an effect that was prevented or reversed when the h-current was blocked by Cs(+). The decreased period could also occur if the pump was inhibited with strophanthidin or K(+)-free saline. Our monensin results were reproduced in model, which explains the pump's contributions to bursting activity based on Na(+) dynamics. Our results indicate that a dynamically oscillating pump current that interacts with the h-current can regulate the bursting activity of neurons and networks.

  17. A large fragment approach to DNA synthesis: total synthesis of a gene for the protease inhibitor eglin c from the leech Hirudo medicinalis and its expression in E. coli.

    PubMed Central

    Rink, H; Liersch, M; Sieber, P; Meyer, F

    1984-01-01

    A DNA containing the coding sequence for the proteinase inhibitor protein, eglin c, from the leech Hirudo medicinalis has been obtained by enzymatic assembly of chemically synthesized DNA fragments. The synthetic gene consists of a 232 base-pair fragment containing initiation and termination codon signals with restriction enzyme recognition sites conveniently placed for cloning into a plasmid vector. Only six oligonucleotides from 34 to 61 bases in length, sharing pairwise stretches of complementary regions at their 3'-termini, were prepared by phosphotriester solid-phase synthesis. The oligomers were annealed pairwise and converted into double stranded DNA fragments by DNA polymerase I mediated repair synthesis. The fragments were assembled by ligation, and the synthetic gene was expressed in high yield in E. coli under the transcriptional control of the E. coli tryptophan promoter. The expression product was purified to homogeneity and was shown to have similar physicochemical and identical biological properties as the authentic protein isolated from the leech. Images PMID:6382168

  18. Evolution of clitellate phaosomes from rhabdomeric photoreceptor cells of polychaetes – a study in the leech Helobdella robusta (Annelida, Sedentaria, Clitellata)

    PubMed Central

    2013-01-01

    Introduction In Annelida two types of photoreceptor cells (PRCs) are regarded as generally present, rhabdomeric and ciliary PRCs. In certain taxa, however, an additional type of PRC may occur, the so called phaosomal PRC. Whereas the former two types of PRCs are always organized as an epithelium with their sensory processes projecting into an extracellular cavity formed by the PRCs and (pigmented) supportive cells, phaosomes are seemingly intracellular vacuoles housing the sensory processes. Phaosomal PRCs are the only type of PRC found in one major annelid group, Clitellata. Several hypotheses have been put forward explaining the evolutionary origin of the clitellate phaosomes. To elucidate the evolution of clitellate PRC and eyes the leech Helobdella robusta, for which a sequenced genome is available, was chosen. Results TEM observations showed that extraocular and ocular PRCs are structurally identical. Bioinformatic analyses revealed predictions for four opsin genes, three of which could be amplified. All belong to the rhabdomeric opsin family and phylogenetic analyses showed them in a derived position within annelid opsins. Gene expression studies showed two of them expressed in the eye and in the extraocular PRCs. Polychaete eye-typic key enzymes for ommochromme and pterin shading pigments synthesis are not expressed in leech eyes. Conclusions By comparative gene-expression studies we herein provide strong evidence that the phaosomal PRCs typical of Clitellata are derived from the rhabdomeric PRCs characteristic for polychaete adult eyes. Thus, they represent a highly derived type of PRC that evolved in the stem lineage of Clitellata rather than another, primitive type of PRC in Metazoa. Evolution of these PRCs in Clitellata is related to a loss of the primary eyes and most of their photoreceptive elements except for the rhabdomeric PRCs. Most likely this happened while changing to an endobenthic mode of life. This hypothesis of PRC evolution is in accordance

  19. Differential Expression of Conserved Germ Line Markers and Delayed Segregation of Male and Female Primordial Germ Cells in a Hermaphrodite, the Leech Helobdella

    PubMed Central

    Cho, Sung-Jin; Vallès, Yvonne; Weisblat, David A.

    2014-01-01

    In sexually reproducing animals, primordial germ cells (PGCs) are often set aside early in embryogenesis, a strategy that minimizes the risk of genomic damage associated with replication and mitosis during the cell cycle. Here, we have used germ line markers (piwi, vasa, and nanos) and microinjected cell lineage tracers to show that PGC specification in the leech genus Helobdella follows a different scenario: in this hermaphrodite, the male and female PGCs segregate from somatic lineages only after more than 20 rounds of zygotic mitosis; the male and female PGCs share the same (mesodermal) cell lineage for 19 rounds of zygotic mitosis. Moreover, while all three markers are expressed in both male and female reproductive tissues of the adult, they are expressed differentially between the male and female PGCs of the developing embryo: piwi and vasa are expressed preferentially in female PGCs at a time when nanos is expressed preferentially in male PGCs. A priori, the delayed segregation of male and female PGCs from somatic tissues and from one another increases the probability of mutations affecting both male and female PGCs of a given individual. We speculate that this suite of features, combined with a capacity for self-fertilization, may contribute to the dramatically rearranged genome of Helobdella robusta relative to other animals. PMID:24217283

  20. Na+/K+ pump interacts with the h-current to control bursting activity in central pattern generator neurons of leeches

    PubMed Central

    Kueh, Daniel; Barnett, William H; Cymbalyuk, Gennady S; Calabrese, Ronald L

    2016-01-01

    The dynamics of different ionic currents shape the bursting activity of neurons and networks that control motor output. Despite being ubiquitous in all animal cells, the contribution of the Na+/K+ pump current to such bursting activity has not been well studied. We used monensin, a Na+/H+ antiporter, to examine the role of the pump on the bursting activity of oscillator heart interneurons in leeches. When we stimulated the pump with monensin, the period of these neurons decreased significantly, an effect that was prevented or reversed when the h-current was blocked by Cs+. The decreased period could also occur if the pump was inhibited with strophanthidin or K+-free saline. Our monensin results were reproduced in model, which explains the pump’s contributions to bursting activity based on Na+ dynamics. Our results indicate that a dynamically oscillating pump current that interacts with the h-current can regulate the bursting activity of neurons and networks. DOI: http://dx.doi.org/10.7554/eLife.19322.001 PMID:27588351

  1. Lineage analysis of micromere 4d, a super-phylotypic cell for Lophotrochozoa, in the leech Helobdella and the sludgeworm Tubifex

    PubMed Central

    Gline, Stephanie E.; Nakamoto, Ayaki; Cho, Sung-Jin; Chi, Candace; Weisblat, David A.

    2011-01-01

    The super-phylum Lophotrochozoa contains the plurality of extant animal phyla and exhibits a corresponding diversity of adult body plans. Moreover, in contrast to Ecdysozoa and Deuterostomia, most lophotrochozoans exhibit a conserved pattern of stereotyped early divisions called spiral cleavage. In particular, bilateral mesoderm in most lophotrochozoan species arises from the progeny of micromere 4d, which is assumed to be homologous with a similar cell in the embryo of the ancestral lophotrochozoan, more than 650 million years ago. Thus, distinguishing the conserved and diversified features of cell fates in the 4d lineage among modern spiralians is required to understand how lophotrochozoan diversity has evolved by changes in developmental processes. Here we analyze cell fates for the early progeny of the bilateral daughters (M teloblasts) of micromere 4d in the leech Helobdella sp. Austin, a clitellate annelid. We show that the first six progeny of the M teloblasts (em1–em6) contribute five different sets of progeny to non-segmental mesoderm, mainly in the head and in the lining of the digestive tract. The latter feature, associated with cells em1 and em2 in Helobdella, is seen with the M teloblast lineage in a second clitellate species, the sludgeworm Tubifex tubifex and, on the basis of previously published work, in the initial progeny of the M teloblast homologs in molluscan species, suggesting that it may be an ancestral feature of lophotrochozoan development. PMID:21295566

  2. Description of a new leech species of Helobdella (Clitellata: Glossiphoniidae) from Mexico with a review of Mexican congeners and a taxonomic key.

    PubMed

    Salas-Montiel, Ricardo; Phillips, Anna J; De Leon, Gerardo Perez-Ponce; Oceguera-Figueroa, Alejandro

    2014-12-19

    To date, six species of the leech genus Helobdella have been recorded from Mexico: Helobdella atli, Helobdella elongata, Helobdella octatestisaca, Helobdella socimulcensis, Helobdella virginiae and Helobdella temiscoensis n. sp. This new species is characterized by a lanceolate body, the presence of a nuchal scute, uniform brown pigment on both dorsal and ventral surfaces, the absence of papillae, well-separated eyespots, six pairs of testisacs and five pairs of crop caeca, the last of which forms posterior caeca. In addition, we provide new geographic records for Helobdella species from Mexico resulting from our own collections, vouchers deposited at the Colección Nacional de Helmintos from the Instituto de Biología, UNAM, Mexico and vouchers at the Invertebrate Zoology Collection of the Smithsonian's National Museum of Natural History (USNM) Washington D.C., USA. We present a comprehensive review of Mexican Helobdella species, including the new species, with notes on the characteristic morphology and geographic distribution of each species with 91 new records from 20 states. In addition, we provide a taxonomic key for the identification of the Mexican species.

  3. Comparison of the effects of millimeter wave irradiation, general bath heating, and localized heating on neuronal activity in the leech ganglion

    NASA Astrophysics Data System (ADS)

    Romanenko, Sergii; Siegel, Peter H.; Wagenaar, Daniel A.; Pikov, Victor

    2013-02-01

    The use of electrically-induced neuromodulation has grown in importance in the treatment of multiple neurological disorders such as Parkinson's disease, dystonia, epilepsy, chronic pain, cluster headaches and others. While electrical current can be applied locally, it requires placing stimulation electrodes in direct contact with the neural tissue. Our goal is to develop a method for localized application of electromagnetic energy to the brain without direct tissue contact. Toward this goal, we are experimenting with the wireless transmission of millimeter wave (MMW) energy in the 10-100 GHz frequency range, where penetration and focusing can be traded off to provide non-contact irradiation of the cerebral cortex. Initial experiments have been conducted on freshly-isolated leech ganglia to evaluate the real-time changes in the activity of individual neurons upon exposure to the MMW radiation. The initial results indicate that low-intensity MMWs can partially suppress the neuronal activity. This is in contrast to general bath heating, which had an excitatory effect on the neuronal activity. Further studies are underway to determine the changes in the state of the membrane channels that might be responsible for the observed neuromodulatory effects.

  4. The marine leech Stibarobdella loricata (Harding, 1924) (Hirudinea, Piscicolidae), parasitic on the angel shark Squatina spp. and sandtiger shark Carcharias taurus Rafinesque, 1810 (Chondrichthyes: Squatinidae, Carchariidae) in Southern Brazilian waters.

    PubMed

    Soto, J M R

    2003-11-01

    The presence of the marine leech, Stibarobdella loricata (Harding, 1924) (Hirudinea, Piscicolidae), is reported on the southern coast of Brazil, based on seven lots with 47 specimens, between 71 and 182 mm in total length, collected on the dorsal region of angel sharks, Squatina argentina (Marini, 1930); S. guggenheim Marini, 1936; S. punctata Marini, 1936 (Chondrichthyes, Squatinidae); and on the head of a sandtiger shark, Carcharias taurus Rafinesque, 1810 (Chondrichthyes, Carchariidae). This is the first record of S. loricata in the western Atlantic and of its parasitic association with S. argentina, S. guggenheim, S. punctata, and C. taurus.

  5. Mucinivorans hirudinis gen. nov., sp. nov., an anaerobic, mucin-degrading bacterium isolated from the digestive tract of the medicinal leech Hirudo verbana

    PubMed Central

    Nelson, Michael C.; Bomar, Lindsey; Maltz, Michele

    2015-01-01

    Three anaerobic bacterial strains were isolated from the digestive tract of the medicinal leech Hirudo verbana, using mucin as the primary carbon and energy source. These strains, designated M3T, M4 and M6, were Gram-stain-negative, non-spore-forming and non-motile. Cells were elongated bacilli approximately 2.4 µm long and 0.6 µm wide. Growth only occurred anaerobically under mesophilic and neutral pH conditions. All three strains could utilize multiple simple and complex sugars as carbon sources, with glucose fermented to acid by-products. The DNA G+C contents of strains M3T, M4 and M6 were 44.9, 44.8 and 44.8 mol%, respectively. The major cellular fatty acid of strain M3T was iso-C15 : 0. Phylogenetic analysis of full-length 16S rRNA gene sequences revealed that the three strains shared >99 % similarity with each other and represent a new lineage within the family Rikenellaceae of the order Bacteroidales, phylum Bacteroidetes. The most closely related bacteria to strain M3T based on 16S rRNA gene sequences were Rikenella microfusus DSM 15922T (87.3 % similarity) and Alistipes finegoldii AHN 2437T (87.4 %). On the basis of phenotypic, genotypic and physiological evidence, strains M3T, M4 and M6 are proposed as representing a novel species of a new genus within the family Rikenellaceae, for which the name Mucinivorans hirudinis gen. nov., sp. nov. is proposed. The type strain of Mucinivorans hirudinis is M3T ( = ATCC BAA-2553T = DSM 27344T). PMID:25563920

  6. Using a model to assess the role of the spatiotemporal pattern of inhibitory input and intrasegmental electrical coupling in the intersegmental and side-to-side coordination of motor neurons by the leech heartbeat central pattern generator.

    PubMed

    García, Paul S; Wright, Terrence M; Cunningham, Ian R; Calabrese, Ronald L

    2008-09-01

    Previously we presented a quantitative description of the spatiotemporal pattern of inhibitory synaptic input from the heartbeat central pattern generator (CPG) to segmental motor neurons that drive heartbeat in the medicinal leech and the resultant coordination of CPG interneurons and motor neurons. To begin elucidating the mechanisms of coordination, we explore intersegmental and side-to-side coordination in an ensemble model of all heart motor neurons and their known synaptic inputs and electrical coupling. Model motor neuron intrinsic properties were kept simple, enabling us to determine the extent to which input and electrical coupling acting together can account for observed coordination in the living system in the absence of a substantive contribution from the motor neurons themselves. The living system produces an asymmetric motor pattern: motor neurons on one side fire nearly in synchrony (synchronous), whereas on the other they fire in a rear-to-front progression (peristaltic). The model reproduces the general trends of intersegmental and side-to-side phase relations among motor neurons, but the match with the living system is not quantitatively accurate. Thus realistic (experimentally determined) inputs do not produce similarly realistic output in our model, suggesting that motor neuron intrinsic properties may contribute to their coordination. By varying parameters that determine electrical coupling, conduction delays, intraburst synaptic plasticity, and motor neuron excitability, we show that the most important determinant of intersegmental and side-to-side phase relations in the model was the spatiotemporal pattern of synaptic inputs, although phasing was influenced significantly by electrical coupling.

  7. LEECH: LBTI Exozodi Exoplanet Common Hunt

    NASA Astrophysics Data System (ADS)

    Skemer, Andrew

    We propose to perform a direct exoplanet imaging survey around nearby (<25 pc), intermediate-aged (0.1-1.0 Gyr) stars using the LBT adaptive optics system (LBTAO) and the mid-infrared imager, LBTI. LBTAO is the first of the next generation extreme AO systems to come online and the only one that will operate in the mid-infrared (>3μm), where old/cool planets are brightest, and adaptive optics performance is superb (>95% Strehl ratio for LBTAO). The proposed survey will leverage 60 nights already-allocated to the NASA LBTI exozodiacal dust survey, which will target nearby stars with nulling interferometry to search for faint, warm debris disks. LBTI has a 3-5μm imager/spectrograph (LMIRCam) and an 8-13μm imager/spectrograph/nuller (NOMIC), which can be operated simultaneously using a beamsplitter, meaning that LMIRCam can search for gas-giant planets while NOMIC measures exozodiacal emission. Executing these two surveys simultaneously will greatly increase the scientific productivity of 60 already-allocated NASA nights by 1) creating exoplanet discovery opportunities and 2) providing a synergetic data set for studying debris disks (exozodis) as signposts of giant planets. The exozodi survey sample is older than the samples of other planned direct imaging surveys, which look at younger stars (<100 Myr) due to the fact that planets become fainter as they age. LBTI is still sensitive to planets around older stars because it operates at L (3.8 μm) where evolutionary models predict planets fade more slowly than at the wavelengths used by most direct-imaging surveys, (H; 1.65 μm). The ability to detect planets around nearby (<25 pc) intermediante-aged (0.1-1.0 Gyr) stars presents several scientific opportunities: 1) A variety of evolutionary models (hot-start, core-accretion/cold-start, warm-start) predict different cooling curves for extrasolar planets, based on different initial conditions. By imaging a population of old planets, we will determine how the planet population evolves by comparing our results to the young planet surveys (e.g. GPI and SPHERE). 2) Initial results show that young planets (such as HR 8799 bcde and 2M1207 b) have very different atmospheres from their older and more massive brown-dwarf analogs. Our sample is intermediate in age between the very young planets that will be discovered by other direct imaging surveys and the very old field brown- dwarf population. Multi-wavelength characterization of our old-planet sample will provide a key intermediate step for atmospheric models. 3) Our sample is composed of the nearest stars, which have been extensively studied by other types of surveys (Doppler RV planet searches, Spitzer and Herschel debris disk observations, and the concurrent LBTI exozodiacal dust survey). The combination of all of these data will reveal the overall architectures of planetary systems by constraining the presence of inner giant planets with RV data, outer giant planets with LBTI direct imaging, hot debris disks with LBTI exozodi data, and cold debris disks with Spitzer and Herschel. Based on planet population models and on-sky estimates of the LBTAO/LBTI instrument performance, we expect to discover ~2-7 planets by observing 117 nearby stars over the next 4 years. These planets will be older and nearer to the Sun than planets found by other surveys, and will benefit from synergetic data from several other surveys that target the nearest stars. Using these new discoveries, we will constrain the atmospheric and evolutionary models for intermediate-aged planets, and determine the extent to which debris disks can be used as signposts of extrasolar planets.

  8. Chinese Medicinal Leech: Ethnopharmacology, Phytochemistry, and Pharmacological Activities

    PubMed Central

    Dong, Han; Ren, Ji-Xiang; Wang, Jing-Jing; Ding, Li-Shuai; Zhao, Jian-Jun; Liu, Song-Yan; Gao, Hui-Min

    2016-01-01

    Hirudo (Shuizhi in Chinese) is an important Chinese medicine, which possesses many therapeutic properties for the treatment of the cerebral hemorrhage and other thrombosis-related diseases. The phytochemical investigation gave more than 51 compounds including pteridines, phosphatidylcholines, glycosphingolipids, and sterols, as well as some bioactive peptides from the Shuizhi derived from three animal species recorded in the current Chinese Pharmacopoeia. The pharmacological studies on the Shuizhi have revealed various activities such as anticoagulation, antithrombosis, antiatherosclerosis, antiplatelet aggregation, antitumor and anti-inflammatory as well as hemorheology improvement, and protective effects against cerebral ischemia-reperfusion injury. However, some important issues based on the traditional uses of Shuizhi are still not clear. The aim of the present review is to provide comprehensive knowledge on the ethnopharmacology, phytochemistry, and pharmacological activities of Shuizhi. It will provide a potential guidance in exploring main active compounds of Shuizhi and interpreting the action mechanism for the further research. PMID:27274755

  9. Land Leeches of the g.Haemadipsa (Haemadipsoidea:Haemadipsidae). II. Bibliography.

    DTIC Science & Technology

    1982-05-01

    Sangsues Terrestres). Bull Soc Pathol Exot 10:640-675, 1917 10. DEQUAL, L. Nuovi Irudinei esotici del Museo Zoologico di Torino. Boll Mus Zool Anat Comp...A. Forest pests man should avoid. Philipp J For 3:191-201, 1940 DEQUAL, L. Nuovi Irudinei esotici del Museo Zoologico di Torino. BtI)i Mus Zool Anat

  10. From leeches to personalized medicine: evolving concepts in the management of polycythemia vera

    PubMed Central

    Vannucchi, Alessandro M.

    2017-01-01

    Polycythemia vera is a clonal disorder of hematopoietic stem/progenitor cells. It manifests as an expansion of red cell mass. It is the most common chronic myeloproliferative neoplasm. In virtually all cases, it is characterized by a V617F point mutation in JAK2 exon 14 or less common mutations in exon 12. The landmark discovery of the autonomously activated JAK/STAT signaling pathway paved the way for the clinical development of the first target drug, the JAK1 and JAK2 inhibitor ruxolitinib. This is now approved for patients with resistance or intolerance to hydroxyurea. Phlebotomies and hydroxyurea are still the cornerstone of treatment, and aim to prevent the first appearance or recurrence of cardiovascular events that, together with progression to post-polycythemia vera myelofibrosis and leukemia, represent the main causes of death. Interferon-α is an alternative drug and has been shown to induce molecular remissions. It is currently undergoing phase III trials that might eventually lead to its approval for clinical use. The last few years have witnessed important advances towards an accurate early diagnosis of polycythemia vera, greater understanding of its pathogenesis, and improved patient management. This review will focus on the most recent achievements and will aim to unify the different concepts involved in a personalized approach to the patient with polycythemia vera. In spite of many recent advances in the understanding of its pathogenesis and improved disease management, polycythemia vera remains a life-threatening myeloproliferative neoplasm for which there is no cure. This review will present a critical overview of evolving concepts in diagnosis and treatment of this disease. PMID:27884974

  11. Characterization of a voltage-dependent conductance in the basolateral membrane of leech skin epithelium.

    PubMed

    Schnizler, M; Clauss, W

    1998-05-01

    Voltage clamp studies were performed on the dorsal integument of Hirudo medicinalis. Under apical calcium-free conditions an inward-directed component of transepithelial current was activated by changes of transepithelial voltage. Depolarization caused up to 50% increase of the transepithelial sodium current. Hyperpolarization had no comparable effects. With calcium (1.8 mM) or amiloride (100 microM) in the apical solution and in sodium-free solutions the inward-directed current failed to increase after depolarization. Activation also occurred under chloride-free conditions. Permeabilization of the apical membrane by nystatin (5 microM) increased the current activation significantly. After nystatin, calcium as well as amiloride lost their inhibitory effects. This indicates a basolateral localization of the voltage-dependent conductance. Vesicle insertion or cytoskeletal structures are probably not involved in regulation, as seen by the lack of effects of brefeldin A and the cytochalasins B and D. However, serosal hyposmolar solutions (170 mosmol.1(-1)) caused a reinforced activation of the current. Our results indicate a voltage-dependent conductance in a tight sodium-absorbing epithelium.

  12. The complete mitochondrial genome of Sasakia funebris (Leech) (Lepidoptera: Nymphalidae) and comparison with other Apaturinae insects.

    PubMed

    Wang, Ju Ping; Cao, Tian Wen; Xuan, Shan Bin; Wang, Hui; Zhang, Min; Ma, En bo

    2013-09-10

    Sasakia funebris, a member of the lepidopteran family, Nymphalidae (superfamily Papilionoidea) is a rare species and is found only in some areas of South China. In this study, the 15,233 bp long complete mitochondrial genome of S. funebris was determined, and harbors the gene arrangement identical to all other sequenced lepidopteran insects. The nucleotide composition of the genome is highly A+T biased, accounting for 81.2%. All protein-coding genes (PCGs) start with typical ATN codons, except for COI which begins with the CGA codon. All tRNAs have a typical clover-leaf secondary structure, except for tRNASer(AGN), the dihydrouridine (DHU) arm of which forms a simple loop. The S. funebris A+T-rich region of 370 bp contains several features common to the Lepidoptera insects, including the motif ATAGA followed by a 19 bp poly-T stretch, and two tandem repeats consisting of 18 bp repeat units and 14 bp repeat units. The phylogenetic analyses of Apaturinae based on mitogenome sequences showed: (S. funebris+Sasakia charonda)+(Apatura metis+Apatura ilia). This result is consistent with the morphological classification.

  13. [Leeching in the treatment of chronic inflammatory and dystrophic diseases of the salivary glands].

    PubMed

    Abal'masov, D V; Afanas'ev, V V; Pozharitskaia, M M

    2003-01-01

    Twenty patients with chronic inflammatory and dystrophic diseases of the salivary glands (sialadenitis, sialadenosis) were examined and treated using hirudotherapy. Positive clinical shifts were observed in 50% patients; the most pronounced therapeutic effect was observed in patients with sialadenosis. Hirudotherapy was ineffective in patients with chronic parenchymatous parotitis paralleled by Sjogren's syndrome.

  14. ANATOMY, LIFE HISTORY AND DISTRIBUTION OF THE PARASITIC LEECH OLIGOBDELLA BIANNULATA (MOORE, 1900) (EUHIRUDINEA: GLOSSIPHONIIDAE)

    EPA Science Inventory

    Oligobdella biannulata (Moore, 1900) is a rare, endemic species originally described from a mountain stream near Blowing Rock, North Carolina. Specimens of this species were collected seasonally from fall 1999 to winter 2001 with four new county records in North Carolina (Avery,...

  15. `Don't forget your leech socks'! Children's learning during an Eden Education Officer's workshop

    NASA Astrophysics Data System (ADS)

    Bowker, Rob; Jasper, Andy

    2007-04-01

    This study looked at 30 primary aged children between 10 and 11 years old who were visiting the Eden Project, Cornwall and participating in workshops led and designed by the Eden Education Officers. The study attempted to directly test the effects of the Education Officers' workshops on children's learning. Personal meaning mapping, a constructivist approach was used to measure change in the children's understanding along four semi-independent dimensions: extent, breadth, depth and mastery. The children's mastery of the subject regardless of ability was improved. Most of the workshop aims, such as ‘to recognise some plant adaptations in the humid tropics climate’ were shown to have been met. The research also highlighted areas to be reviewed, such as educating children about the way indigenous people use plants for their survival and also how children can transfer knowledge, so that they can understand the significance of plants in their own daily lives.

  16. The Iberian Leech: Napoleon’s Counterinsurgency Operations in the Peninsula, 1807-1810

    DTIC Science & Technology

    2007-11-02

    virtue of her Moorish blood. “Africa begins at the Pyrenees ,” is more than an apt phrase. It expresses succinctly the exotic, half-oriental quality...poured their blood and energy into the dead-end funnel that is Spain. The towering Pyrenees have sealed that funnel off from the rest of Europe more...Napoleon only required an excuse for entering Spain. Fortunately, for Napoleon, he had help in the Spanish government itself. This came in the form of the

  17. "Don't Forget Your Leech Socks"! Children's Learning during an Eden Education Officer's Workshop

    ERIC Educational Resources Information Center

    Bowker, Rob; Jasper, Andy

    2007-01-01

    This study looked at 30 primary aged children between 10 and 11 years old who were visiting the Eden Project, Cornwall and participating in workshops led and designed by the Eden Education Officers. The study attempted to directly test the effects of the Education Officers' workshops on children's learning. Personal meaning mapping, a…

  18. New Host and Distribution Records of the Leech Placobdella sophieaeOceguera-Figueroa et al., 2010 (Hirudinida: Glossiphoniidae)

    USGS Publications Warehouse

    Moser, William E.; Bowerman, Jay; Hovingh, Peter; Pearl, Christopher A.; Oceguera-Figueroa, Alajandro

    2014-01-01

    Placobdella sophieae Oceguera-Figueroa et al., 2010 (Hirudinida: Glossiphoniidae) is reported from Oregon, California, and British Columbia for the first time. New hosts reported for P. sophieae include Taricha granulosa (rough-skinned newt), Rana pretiosa (Oregon spotted frog), and Anaxyrus boreas (western toad). Placobdella sophieae exhibits relatively low host specificity and all amphibians occurring in the Pacific Northwest are potential hosts.

  19. Cultural Resources Survey Subterranean Cable Right-of-Way Adjacent to Leech Lake River, Cass County, Minnesota.

    DTIC Science & Technology

    1980-09-01

    of his youthful enthusiasm and his considerable muscle ; the latter provided his expertise in soils and vegetation both in the field and by preparing...requested, the Contractin . Officer will provide thle Contractor w-ith a letter of introduction signed by the St. Paul District Engineer explaining the

  20. The LEECH Exoplanet Imaging Survey: Orbit and Component Masses of the Intermediate-Age, Late-Type Binary NO UMa

    NASA Astrophysics Data System (ADS)

    Schlieder, Joshua E.; Skemer, Andrew J.; Maire, Anne-Lise; Desidera, Silvano; Hinz, Philip; Skrutskie, Michael F.; Leisenring, Jarron; Bailey, Vanessa; Defrère, Denis; Esposito, Simone; Strassmeier, Klaus G.; Weber, Michael; Biller, Beth A.; Bonnefoy, Mickaël; Buenzli, Esther; Close, Laird M.; Crepp, Justin R.; Eisner, Josh A.; Hofmann, Karl-Heinz; Henning, Thomas; Morzinski, Katie M.; Schertl, Dieter; Weigelt, Gerd; Woodward, Charles E.

    2016-02-01

    We present high-resolution Large Binocular Telescope LBTI/LMIRcam images of the spectroscopic and astrometric binary NO UMa obtained as part of the LBT Interferometer Exozodi Exoplanet Common Hunt exoplanet imaging survey. Our H-, Ks-, and L‧-band observations resolve the system at angular separations <0.″09. The components exhibit significant orbital motion over a span of ∼7 months. We combine our imaging data with archival images, published speckle interferometry measurements, and existing spectroscopic velocity data to solve the full orbital solution and estimate component masses. The masses of the K2.0 ± 0.5 primary and K6.5 ± 0.5 secondary are 0.83 ± 0.02 M⊙ and 0.64 ± 0.02 M⊙, respectively. We also derive a system distance of d = 25.87 ± 0.02 pc and revise the Galactic kinematics of NO UMa. Our revised Galactic kinematics confirm NO UMa as a nuclear member of the ∼500 Myr old Ursa Major moving group, and it is thus a mass and age benchmark. We compare the masses of the NO UMa binary components to those predicted by five sets of stellar evolution models at the age of the Ursa Major group. We find excellent agreement between our measured masses and model predictions with little systematic scatter between the models. NO UMa joins the short list of nearby, bright, late-type binaries having known ages and fully characterized orbits. Based on data obtained with the STELLA robotic telescope in Tenerife, an AIP facility jointly operated by AIP and IAC.

  1. A new and alien species of ``oyster leech'' (Platyhelminthes, Polycladida, Stylochidae) from the brackish North Sea Canal, The Netherlands

    NASA Astrophysics Data System (ADS)

    Sluys, Ronald; Faubel, Anno; Rajagopal, Sanjeevi; Velde, Gerard Van Der

    2005-11-01

    A new species of polyclad flatworm, Imogine necopinata Sluys, sp. nov., is described from a brackish habitat in The Netherlands. Taxonomic affinities with Asian species and the ecology of the animals suggest that the species is an introduced, exotic component of the Dutch fauna. The new species belongs to a group of worms with species that are known to predate on oysters.

  2. Cultural Resources Investigation of the Reservoir Shorelines: Gull Lake, Leech Lake, Pine River, and Lake Pokegama. Volume 1,

    DTIC Science & Technology

    1979-06-01

    Douglas Birk cites William Warren (1852), Lewis and Clark (1804-1806), Henry Schoolcraft (1820) and Nicholas King (1805-1807) to substantiate the loc...suggests this is the post indicated on Lewis’ and Clark’s map from the expedition in 1804-1806. (Birk, 1970: 2) Schoolcraft , in 1820, says there was an old...offshore. CM a -. >.dl aA Figure 27. Lithic artifacts from site CA 43. Top row ; left, triangular point: * center, bifacially flaked knife; right, side

  3. Hydrogeology and ground-water quality of glacial-drift aquifers, Leech Lake Indian Reservation, north-central Minnesota

    USGS Publications Warehouse

    Lindgren, R.J.

    1996-01-01

    Water collected from wells completed in the unconfined aquifer in residential and recreational land-use areas had concentrations of arsenic, cadmium, chromium, copper, lead, mercury, and cyanide equal to or less than 6 micrograms per liter. Concentrations of organic-acid herbicides in water from three wells screened in the unconfined aquifer in managed-forest land-use areas were all below detection levels. Concentrations of U.S. Environmental Protection Agency priority pollutants in water from three wells screened in the unconfined aquifer and from one well screened in the uppermost confined aquifer were also all below detection levels.

  4. THE LEECH EXOPLANET IMAGING SURVEY: ORBIT AND COMPONENT MASSES OF THE INTERMEDIATE-AGE, LATE-TYPE BINARY NO UMa

    SciTech Connect

    Schlieder, Joshua E.; Skemer, Andrew J.; Hinz, Philip; Leisenring, Jarron; Defrère, Denis; Close, Laird M.; Eisner, Josh A.; Maire, Anne-Lise; Desidera, Silvano; Skrutskie, Michael F.; Bailey, Vanessa; Esposito, Simone; Strassmeier, Klaus G.; Weber, Michael; Biller, Beth A.; Bonnefoy, Mickaël; Buenzli, Esther; Henning, Thomas; Crepp, Justin R.; Hofmann, Karl-Heinz; and others

    2016-02-10

    We present high-resolution Large Binocular Telescope LBTI/LMIRcam images of the spectroscopic and astrometric binary NO UMa obtained as part of the LBT Interferometer Exozodi Exoplanet Common Hunt exoplanet imaging survey. Our H-, K{sub s}-, and L′-band observations resolve the system at angular separations <0.″09. The components exhibit significant orbital motion over a span of ∼7 months. We combine our imaging data with archival images, published speckle interferometry measurements, and existing spectroscopic velocity data to solve the full orbital solution and estimate component masses. The masses of the K2.0 ± 0.5 primary and K6.5 ± 0.5 secondary are 0.83 ± 0.02 M{sub ⊙} and 0.64 ± 0.02 M{sub ⊙}, respectively. We also derive a system distance of d = 25.87 ± 0.02 pc and revise the Galactic kinematics of NO UMa. Our revised Galactic kinematics confirm NO UMa as a nuclear member of the ∼500 Myr old Ursa Major moving group, and it is thus a mass and age benchmark. We compare the masses of the NO UMa binary components to those predicted by five sets of stellar evolution models at the age of the Ursa Major group. We find excellent agreement between our measured masses and model predictions with little systematic scatter between the models. NO UMa joins the short list of nearby, bright, late-type binaries having known ages and fully characterized orbits.

  5. Transcriptome Sequence of the Bloodstream Form of Trypanoplasma borreli, a Hematozoic Parasite of Fish Transmitted by Leeches

    PubMed Central

    Carrington, Mark; Dóró, Eva; Wiegertjes, Geert F.

    2017-01-01

    ABSTRACT Here, we report a transcriptome sequence of Trypanoplasma borreli isolated from its natural host, the common carp, Cyprinus carpio. The transcriptome allows an analysis of abundant cell surface proteins and acts as a comparator for understanding the evolution and pathogenicity of other Kinetoplastida, including several that infect humans. PMID:28254980

  6. Oogenesis in the leech Glossiphonia heteroclita (Annelida, Hirudinea, Glossiphoniidae) II. Vitellogenesis, follicle cell structure and egg shell formation.

    PubMed

    Swiatek, Piotr

    2006-08-01

    By the end of previtellogenesis, the oocytes of Glossiphonia heteroclita gradually protrude into the ovary cavity. As a result they lose contact with the ovary cord (which begins to degenerate) and float freely within the hemocoelomic fluid. The oocyte's ooplasm is rich in numerous well-developed Golgi complexes showing high secretory activity, normal and transforming mitochondria, cisternae of rER and vast amounts of ribosomes. The transforming mitochondria become small lipid droplets as vitellogenesis progresses. The oolemma forms microvilli, numerous coated pits and vesicles occur at the base of the microvilli, and the first yolk spheres appear in the peripheral ooplasm. A mixed mechanism of vitellogenesis is suggested. The eggs are covered by a thin vitelline envelope with microvilli projecting through it. The envelope is formed by the oocyte. The vitelline envelope is produced by exocytosis of vesicles containing two kinds of material, one of which is electron-dense and seems not to participate in envelope formation. The cortical ooplasm of fully grown oocytes contains many cytoskeletal elements (F-actin) and numerous membrane-bound vesicles filled with stratified content. Those vesicles probably are cortical granules. The follicle cells surrounding growing oocytes have the following features: (1) they do not lie on a basal lamina; (2) their plasma membrane folds deeply, forming invaginations which eventually seem to form channels throughout their cytoplasm; (3) the plasma membrane facing the ovary lumen is lined with a layer of dense material; and (4) the plasma membrane facing the oocyte forms thin projections which intermingle with the oocyte microvilli. In late oogenesis, the follicle cells detach from the oocytes and degenerate in the ovary lumen.

  7. New records of the chaetiferous leech-like annelid Paracanthobdella livanowi (Epshtein, 1966) (Annelida: Clitellata: Acanthobdellida) from Kamchatka, Russia.

    PubMed

    Utevsky, Serge Y; Sokolov, Sergei G; Shedko, Marina B

    2013-01-01

    Acanthobdellidans are unique in their organisation and phylogenetic relationships due to having transitional characters that combine features of oligochaetous and achaetous annelids. Alongside the relatively well-studied Acanthobdella peledina Grube, 1851, there is another member of the group, Paracanthobdella livanowi (Epshtein, 1966), with five rows of chaetae and an anterior sucker. It appears that the anterior sucker is weakly developed in small juveniles but acquires a deep cavity in adults. Smaller individuals of P. livanowi can be distinguished from A. peledina, which does not possess an anterior sucker, by the varying breadth of their chaetae. The mid-body segment consists of two doubled annuli in juveniles and is quadri-annulate in large individuals. In Kamchatka freshwaters, hosts of P. livanowi mostly include Salvelinus spp. and more rarely Gasterosteus aculeatus, Oncorhynchus mykiss and O. kisutch. New information on the distribution and the biology of P. livanowi is presented.

  8. Actinobdella inequinnulata (Annelida: Hirudinida:Rhynchobdellida:Glossiphoniidae) from White Crappie, Pomoxis annularis (Perciformes: Centrarchidae), in Arkansas, USA

    EPA Science Inventory

    One of 4 (25%) white crappie, Pomoxis annularis from the Ouachita River, Dallas County, Arkansas, was found to be infested with 8 glossiphoniid leeches, Actinobdella inequiannulata Moore, 1901. Leeches were removed from within the oeprculum on gills and gill arches. This leech i...

  9. Cultural Resources Investigation of the Reservoir Shorelines: Gull Lake, Leech Lake, Pine River and Lake Pokegama. Volume 2. Site Location Data.

    DTIC Science & Technology

    1979-06-01

    affiliation Malmo (Middle Woodland ); Blackduck 4. Location: Sec. 4 Twp. 135N R. 29W Verbal description E NWk north end Upper Gull; just east of bridge over...affiliation Woodland 4. Location: Sec. 25 Twp. 134N R. 30W Verbal description NWk SEk on the southeast arm of the southwest part of Wilson Bay, Gull...mound, village, etc.) mound? burial? 2. Map reference USGS Gull Lake 3. Cultural affiliation Woodland and Historic 4. Location: Sec. 21 Tp. 135N R. 29W

  10. Case report of oral cavity infestation in a 3-year old jackass with Limnatis nilotica from Ilam province, west of Iran

    PubMed Central

    Bahmani, Mahmoud; Karamati, Seyed Ahmad; Anari, Morteza Mohamad Hosseini; Rahimirad, Amir; Asadzadeh, Jafar; Kheiri, Aghakhan; Hajiglolizadeh, Ghader; Ghotbian, Fereidoun; Bahmani, Farzaneh

    2014-01-01

    Leeches (phylum: Annelida, class: hirudinea) could infest wide range of livestock such as cow, buffalo, sheep, goat, horse, mule, ass, dog, pig and even human. In November 2013, a 3-year old jackass from Dehloran county, Ilam province, Iran, was infected through his mouth due to drinking spring water. Symptoms including stress, anxiety and tachycardia were seen. After examining oral cavity of jackass, a leech was observed in upper gum. The leech was measured after separation which was three inches in length. The leech was adult which has dark green with orange lines, and it was identified as Limnatis nilotica species. It seems that using spring, subterranean water, pond etc. is the main causes of livestock infestation with leech. Ranchers could be recommended to decontaminate leech waters to prevent further leech infestation cases.

  11. Hirudotherapy in Medicine and Dentistry

    PubMed Central

    Garg, Aarti; Narang, Ridhi; Das, Sunanda

    2015-01-01

    The concept of Unani medicine is based on balancing body humours, the imbalance of which causes diseases. The application of leech therapy in medical and dental science is well recognized. Although easy and non-invasive, complications also exist. The article aims to presents a brief review on the applications of leech therapy. The physiological effect, along with its therapeutic role in cancer, diabetes and dentistry have been underlined. Complications of leech therapy have also been dealt with. PMID:26817000

  12. Molecular Identification of Haemadipsa rjukjuana (Hirudiniformes: Haemadipsidae) in Gageo Island, Korea.

    PubMed

    Won, Sohyun; Park, Bae Keun; Kim, Baek Jun; Kim, Hye Won; Kang, Jun Gu; Park, Tae Seo; Seo, Hong Yul; Eun, Ye; Kim, Ki Gyoung; Chae, Joon Seok

    2014-04-01

    There are 60 species of blood-feeding land leeches, 50 species belonging to the family Haemadipsidae and 10 species belonging to the family Xerobdellidae. Despite recent papers on the land leeches, their taxonomic identification is not fully understood, especially at a species level. In Korea, there have been no historical records of the terrestrial leeches, but recently an unrecorded blood-feeding land leech was discovered at Gageo-do (Island), Korea. Molecular analysis was used to identify the species of 29 leeches collected from Mt. Dock-Sil in Gageo-do. Conventional PCR was conducted using nuclear 18S rRNA and mitochondrial cytochrome c oxidase subunit 1 (CO1) genetic marker. The 18S rRNA sequences revealed that the leeches share 99.9% identity with Haemadipsa rjukjuana (inhabiting Taiwan), and the CO1 sequences revealed that the leeches are very close to H. rjukjuana (inhabiting Taiwan). The CO1 sequences were separated into 2 categories, 1 with 94.6% and the other with 94.3% similarity to the H. rjukjuana L00115A (inhabiting Taiwan). This new finding of the land leech is the first record in Korea. In addition, the north range of the distribution of the blood-feeding leech (Hirudiniformes: Haemadipisidae) should be reconsidered including Korea.

  13. BIOLOGY OF THE LEECH ACTINOBDELLA INEQUIANNULATA MOORE, 1901 (ANNELIDA: HIRUDINEA: RHYNCHOBDELLIDA: GLOSSIPHONIIDAE), PARASITIC ON THE WHITE SUCKER, CATOSTOMUS COMMERSONI LACEPEDE, 1803 AND THE LONGNOSE SUCKER, CATOSTOMUS CATOSTOMUS FORSTER, 1773, IN ALGONQUIN PROVINCIAL PARK, ONTARIO, CANADA

    EPA Science Inventory

    Actinobdella inequiannulata was found on the white sucker, Catostomus commersoni, and less frequently on the longnose sucker, Catostomus catostomus, in Algonquin Provincial Park, Ontario, Canada. Catostomus commersoni parasitized with Act. inequiannulata was collected from July ...

  14. Mississippi Headwaters Reservoirs Oral History Interviews, Series 1 and 2

    DTIC Science & Technology

    1988-06-01

    up. Boat and livery from Wooded country Detroit)Ashelmans Resort, Pelican Lake. Lakes Leech, Sand. (52 lier day and ua) V-) (2) Pettibone Log,&o... Pettibone , Prop. River Leech. (610 per week ad up) (1𔃺 Livery John Rahm’s Auto and Horse Livery, Hotels Stanton, 82 per dlay, capacity 50. Detroit, Minn

  15. Oral hirudiniasis in a stray dog, first report in Italy

    PubMed Central

    RAELE, Donato Antonio; GALANTE, Domenico; CAFIERO, Maria Assunta

    2015-01-01

    In June 2014, a male stray dog was recovered at Ente Nazionale di Protezione Animali (ENPA) kennel of Manfredonia, Apulia region, showing oral bleeding and physical prostration. The dog fell in a water canal and was trapped. During the clinical examination, a specimen of leech was revealed into its oral cavity. The parasite, probably entered by drinking unfiltered and contaminated water, has been identified as an adult of aquatic leech Limnatis nilotica. Leeches could overrun wide variety of animals, and few reports about blood sucking leech infestations in mammals are available in literature. This paper describes here the first oral hirudiniasis in a dog in Italy and highlights the possibility of human nasopharyngeal leech-related infection in Apulia region. PMID:26004432

  16. Bleeding and cupping.

    PubMed Central

    Turk, J. L.; Allen, E.

    1983-01-01

    Bleeding and cupping have been used in medicine since ancient times in the treatment of fevers and local inflammatory disorders. Local bleeding, by 'wet cupping', was effected by a scarificator or by leeches. John Hunter recommended venesection in moderation but preferred leeches for local bleeding. Bleeding as an accepted therapeutic practice went out of vogue in the middle of the nineteenth century as a result of the introduction of modern scientific methods. Dry cupping and the use of leeches, as counter irritants, persisted until the middle of this century. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 PMID:6338802

  17. Training in Methods in Computational Neuroscience

    DTIC Science & Technology

    1992-08-29

    interneuron . These all have active Hodgkin-Huxley-like sodium- and potassiurm-channels, excitatory and inhibitory synapses. These cells and there connections...Leech heart neuron half-ocillator was simulated. The heart tubes of the leech are controlled by interneurons that lie in the third and fourth ganglia...Within a ganglion the right and the left interneuron are connected by mutually inhibitory coonections. This pair forms a half-oscillator which when

  18. Trypanosoma humboldti n. sp. from the Chilean catshark, Schroederichthys chilensis (Guichenot, 1848).

    PubMed

    Morillas, J; George-Nascimento, M; Valeria, H; Khan, R A

    1987-08-01

    The morphology of Trypanosoma humboldti n. sp. is described from living and stained specimens obtained from the blood of a catshark, Schroederichthys chilensis. This represents the first report of a trypanosome in fish from the eastern Pacific Ocean. It is distinguished by its size and apparent lack of pleomorphism. The presence of a leech, Branchellion ravenellii, attached to the catshark, raises the possibility that it can act as a vector. Additionally, this leech is recorded for the first time from the Pacific Ocean.

  19. Hirudotherapy in veterinary medicine.

    PubMed

    Sobczak, Natalia; Kantyka, Magdalena

    2014-01-01

    The saliva of medicinal leeches, e.g., Hirudo medicinalis and Hirudo verbana commonly used in hirudotherapy, contains more than 100 bioactive substances with various therapeutic effects, including anticoagulant, vasodilator, thrombolytic, anti-inflammatory and anaesthetic properties. Recently, leeches have been used very successfully in veterinary medicine to treat many diseases of animals, especially dogs, cats and horses. The most common indications for the use of leeches are hip and elbow dysplasia, acute and chronic arthritis, diseases associated with inflammation of tendons, ligaments, and fascia, diseases of the vertebrae and the treatment of scars. Leech therapy is a painless procedure which takes an average of 30 to 120 minutes, the time being dependent on the size of the animal. All leeches used in medical procedures should originate only from certified biofarms. The maintenance of sterile conditions for the culture, transport and storage of medical leeches is very important to protect animals from microbial infections. Hirudotherapy is successfully used in veterinary medicine, especially when traditional treatment is not effective, the effects of treatment are too slow, or after surgery, when the tissues may be threatened by venous congestion.

  20. Which way is up? Asymmetric spectral input along the dorsal-ventral axis influences postural responses in an amphibious annelid.

    PubMed

    Jellies, John

    2014-11-01

    Medicinal leeches are predatory annelids that exhibit countershading and reside in aquatic environments where light levels might be variable. They also leave the water and must contend with terrestrial environments. Yet, leeches generally maintain a dorsal upward position despite lacking statocysts. Leeches respond visually to both green and near-ultraviolet (UV) light. I used LEDs to test the hypothesis that ventral, but not dorsal UV would evoke compensatory movements to orient the body. Untethered leeches were tested using LEDs emitting at red (632 nm), green (513 nm), blue (455 nm) and UV (372 nm). UV light evoked responses in 100 % of trials and the leeches often rotated the ventral surface away from it. Visible light evoked no or modest responses (12-15 % of trials) and no body rotation. Electrophysiological recordings showed that ventral sensilla responded best to UV, dorsal sensilla to green. Additionally, a higher order interneuron that is engaged in a variety of parallel networks responded vigorously to UV presented ventrally, and both the visible and UV responses exhibited pronounced light adaptation. These results strongly support the suggestion that a dorsal light reflex in the leech uses spectral comparisons across the dorsal-ventral axis rather than, or in addition to, luminance.

  1. Evidence of ectoparasite-induced endocrine disruption in an imperiled giant salamander, the eastern hellbender (Cryptobranchus alleganiensis).

    PubMed

    DuRant, Sarah E; Hopkins, William A; Davis, Andrew K; Romero, L Michael

    2015-07-01

    Parasitic leeches and trypanosomes release chemical signals into their hosts to evade immuno-detection, but it is unknown whether these compounds manipulate host behavior or endocrine physiology. We determined whether parasitic infections with leeches and/or trypanosomes affected the immune and stress response of an imperiled giant species of amphibian, the eastern hellbender (Cryptobranchus alleganiensis Daudin). We monitored corticosterone and white blood cell counts in response to restraint and injection with adrenocorticotropin hormone (ACTH) or saline for up to 50 h. The presence of leeches dampened hellbender corticosterone responses to restraint and reduced diel patterns of plasma corticosterone. Injection with ACTH restored the normal inter-renal responses of hellbenders, suggesting that leeches, possibly through neurotransmitters in leech saliva, cause down-regulation of corticosterone release at the level of the pituitary or hypothalamus. Infection with leeches also increased the relative abundance of eosinophils, white blood cells often recruited into circulation in response to parasitic infection. Lastly, neutrophil to lymphocyte (N:L) ratios increased in all animals after 24 h of capture and remained elevated for up to 50 h, but these temporal dynamics did not differ with parasite infection. Trypanosome infection did not affect any aspect of hellbender physiology that we measured. Our findings reveal a previously undocumented host-parasite dynamic. While the functional significance to the parasite is unclear, the physiological and behavioral implications for the host are great, given the important role of glucocorticoids in regulating physiology and behavior.

  2. 77 FR 2083 - Notice of Inventory Completion: Minnesota Indian Affairs Council, Bemidji, MN

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-13

    ..., one individual were recovered near Ice Cracking Lake during road construction and donated to the... professional staff in consultation with representatives of the Leech Lake Band of the Minnesota Chippewa Tribe... individual were recovered from the north side of Height of Land Lake, site 21BK48, by Mr. William...

  3. Politeness Principle in Cross-Culture Communication

    ERIC Educational Resources Information Center

    Huang, Yongliang

    2008-01-01

    As we all know, different people hold different views about politeness. To be polite, Leech thinks you should follow "Politeness Principle" while Levinson suggests paying attention to others' "Face Wants". Sometimes what the Chinese people considered to be polite may not be true according to western culture. In order to…

  4. Detecting Age in Online Chat

    DTIC Science & Technology

    2009-09-01

    a smaller vocabulary and they preferred using emoticons more than older users [11]. 4. Analysis of Perverted Justice Chat Logs Nick Pender used a...1, 1996. [8] P. Rayson, G. Leech and M. Hodges , "Social differentiation in the use of English vocabulary: some analyses of the conversational

  5. 33 CFR 207.340 - Reservoirs at headwaters of the Mississippi River; use and administration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Mississippi River; use and administration. 207.340 Section 207.340 Navigation and Navigable Waters CORPS OF... headwaters of the Mississippi River; use and administration. (a) Description. These reservoirs include Winnibigoshish, Leech Lake, Pokegama, Sandy Lake, Pine River and Gull Lake. (b) Penalties. The River and...

  6. 33 CFR 207.340 - Reservoirs at headwaters of the Mississippi River; use and administration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Mississippi River; use and administration. 207.340 Section 207.340 Navigation and Navigable Waters CORPS OF... headwaters of the Mississippi River; use and administration. (a) Description. These reservoirs include Winnibigoshish, Leech Lake, Pokegama, Sandy Lake, Pine River and Gull Lake. (b) Penalties. The River and...

  7. 33 CFR 207.340 - Reservoirs at headwaters of the Mississippi River; use and administration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Mississippi River; use and administration. 207.340 Section 207.340 Navigation and Navigable Waters CORPS OF... headwaters of the Mississippi River; use and administration. (a) Description. These reservoirs include Winnibigoshish, Leech Lake, Pokegama, Sandy Lake, Pine River and Gull Lake. (b) Penalties. The River and...

  8. The Most Frequently Used English Phrasal Verbs in American and British English: A Multicorpus Examination

    ERIC Educational Resources Information Center

    Liu, Dilin

    2011-01-01

    This study uses the Corpus of Contemporary American English and the British National Corpus as data and Biber, Johansson, Leech, Conrad, and Finegan's (1999) and Gardner and Davies' (2007) informative studies as a starting point and reference. The study offers a cross-English variety and cross-register examination of the use of English phrasal…

  9. Compare and Contrast Inductive and Deductive Research Approaches

    ERIC Educational Resources Information Center

    Soiferman, L. Karen

    2010-01-01

    This discussion paper compares and contrasts "inductive" and "deductive" research approaches as described by Trochim (2006) and Plano Clark and Creswell (2007). It also examines the "exploratory" and "confirmatory" approaches by Onwueghuzie and Leech (2005) with respect to the assumption each holds about the nature of knowledge. The paper starts…

  10. 77 FR 2085 - Notice of Inventory Completion: Minnesota Indian Affairs Council, Bemidji, MN

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-13

    ... Leech Lake Band of the Minnesota Chippewa Tribe, Minnesota; the Minnesota Chippewa Tribe, Minnesota; and... removed from the Rock Lake area, Becker County, MN, by unknown person(s) and donated to the Becker County... from the north shore of Detroit Lake (Steffen Lot), Becker County, MN, by unknown person(s)...

  11. Endemic Scrub Typhus-like Illness, Chile

    DTIC Science & Technology

    2011-09-01

    assistant professor at the Pontifi cia Universidad Católica de Chile School of Medicine. Her research interests include tuberculosis diagnosis and...1596–9. doi:10.1093/molbev/msm092 13. Kikuchi Y, Fukatsu T. Rickettsia infection in natural leech popu- lations. Microb Ecol. 2005;49:265–71. doi

  12. Hitchhiking of host biology by beneficial symbionts enhances transmission

    PubMed Central

    Ott, Brittany M.; Cruciger, Michael; Dacks, Andrew M.; Rio, Rita V. M.

    2014-01-01

    Transmission plays a key role in the evolution of symbiosis. Mixed mode transmission combines horizontal and vertical mechanisms for symbiont acquisition. However, features that enable mixed transmission are poorly understood. Here, we determine the mechanistic basis for the recruitment of the beneficial bacterium, Aeromonas veronii by the leech, Hirudo verbana. We demonstrate that host mucosal secretions complement imperfect symbiont vertical transmission. First, we show that the A. veronii population within secretions originates from the host digestive tract and proliferates synchronously with shedding frequency, demonstrating the coupling of partner biology. Furthermore, leeches are attracted to these castings with oral contact proving sufficient for symbiont transmission. Leech attraction to mucus is not affected by the symbiont state of either the host or mucus, suggesting that A. veronii exploits preexisting host behavior and physiological traits. A dual transmission mode, integrating multiple layers of host contributions, may prove evolutionarily advantageous for a wide range of symbioses. Using such a strategy, host infection is ensured, while also providing access to a higher genetic diversity of symbionts. Countless host-associated microbes exhibit mixed mode transmission, supporting the use of the leech symbiosis as a model for enhancing our understanding of the specificity, establishment and persistence of microbiotas. PMID:25059557

  13. Partitioned Analysis for Multidisciplinary Problems Involving Structures.

    DTIC Science & Technology

    1986-04-30

    ATTN: R FRANK JOINT STRAT TGT PLANNING STAFF BDM CORP ATTN: JK (ATTN: DNA REP) ATTN: F LEECH LAWRENCE LIVERMORE NATIONAL LABORATORY BDM CORPORATION...KAMAN SCIENCES CORPATTN: LIBRARY/B. KINSLOW AIR FORCE INSTITUTE OF TECHNOLOGY/EN KAMAN SCIENCES CORPORATION ATTN: LIBRARY/AFIT/LDEE ATTN: DASIAC AIR

  14. Laboratory-Scale Airblast Precursor Experiments. Volume 3. HOB (Height of Burst) Studies Micro-Mach Experiments

    DTIC Science & Technology

    1989-03-31

    HEADQUARTERS USAF/IN ATTN: IN RM 4A932 APPLIED RESEARCH ASSOCIATES, INCATTN: R FRANK SECRETARY OF AF/AQQS ATTN: AF/RDQI BDM CORPATTN: F LEECH STRATEGIC...SOUTHWEST RESEARCH INSTITUTE ATTN: B KINSLOW ATTN: A WENZEL KAMAN SCIENCES CORP SRI INTERNATIONAL ATTN: E CONRAD ATTN: J COLTON KAMAN SCIENCES CORPORATION

  15. Silicon-Neuron Junction: Capacitive Stimulation of an Individual Neuron on a Silicon Chip

    NASA Astrophysics Data System (ADS)

    Fromherz, Peter; Stett, Alfred

    1995-08-01

    An identified nerve cell of the leech is attached to a planar silicon microstructure of p-doped silicon covered by a thin layer of insulating silicon oxide. A voltage step, applied between silicon and electrolyte, induces a capacitive transient in the cell which elicits an action potential. The capacitive extracellular stimulation is described by an equivalent electrical four-pole.

  16. Predicting High School Completion Using Student Performance in High School Algebra: A Mixed Methods Research Study

    ERIC Educational Resources Information Center

    Chiado, Wendy S.

    2012-01-01

    Too many of our nation's youth have failed to complete high school. Determining why so many of our nation's students fail to graduate is a complex, multi-faceted problem and beyond the scope of any one study. The study presented herein utilized a thirteen-step mixed methods model developed by Leech and Onwuegbuzie (2007) to demonstrate within a…

  17. 33 CFR 207.340 - Reservoirs at headwaters of the Mississippi River; use and administration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... maintained: Winnibigoshish, 150 cubic feet per second. Leech Lake, 70 cubic feet per second. Pokegama, 200 cubic feet per second. Sandy Lake, 80 cubic feet per second. Pine River, 90 cubic feet per second. Gull Lake, 30 cubic feet per second. (3) During the season of navigation on the upper Mississippi River,...

  18. The Paradox of Fight or Flight - A Leadership Guide to Understanding and Mitigating Operational Stress Injuries

    DTIC Science & Technology

    2006-04-01

    reproduction , both parents transfer sequences or copied portions of their DNA to their offspring. A particular type of DNA - called mitochondrial DNA - is...strength, willpower and self-control.59 To remedy a nostalgic patient, doctors prescribed purging, opium, leeches, and hypnotic emulsions. Less

  19. Three-dimensional visualisation of developmental stages of an apicomplexan fish blood parasite in its invertebrate host

    PubMed Central

    2011-01-01

    Background Although widely used in medicine, the application of three-dimensional (3D) imaging to parasitology appears limited to date. In this study, developmental stages of a marine fish haemogregarine, Haemogregarina curvata (Apicomplexa: Adeleorina), were investigated in their leech vector, Zeylanicobdella arugamensis; this involved 3D visualisation of brightfield and confocal microscopy images of histological sections through infected leech salivary gland cells. Findings 3D assessment demonstrated the morphology of the haemogregarine stages, their spatial layout, and their relationship with enlarged host cells showing reduced cellular content. Haemogregarine meronts, located marginally within leech salivary gland cells, had small tail-like connections to the host cell limiting membrane; this parasite-host cell interface was not visible in two-dimensional (2D) light micrographs and no records of a similar connection in apicomplexan development have been traced. Conclusions This is likely the first account of the use of 3D visualisation to study developmental stages of an apicomplexan parasite in its invertebrate vector. Elucidation of the extent of development of the haemogregarine within the leech salivary cells, together with the unusual connections between meronts and the host cell membrane, illustrates the future potential of 3D visualisation in parasite-vector biology. PMID:22107751

  20. Qualitative Analysis Techniques for the Review of the Literature

    ERIC Educational Resources Information Center

    Onwuegbuzie, Anthony J.; Leech, Nancy L.; Collins, Kathleen M. T.

    2012-01-01

    In this article, we provide a framework for analyzing and interpreting sources that inform a literature review or, as it is more aptly called, a research synthesis. Specifically, using Leech and Onwuegbuzie's (2007, 2008) frameworks, we delineate how the following four major source types inform research syntheses: talk, observations,…

  1. GABA-ergic neurons in the leach central nervous system

    SciTech Connect

    Cline, H.T.

    1985-01-01

    GABA is a candidate for an inhibitory neurotransmitter in the leech central nervous system because of the well-documented inhibitory action of GABA in other invertebrates. To demonstrate that GABA meets the criteria used to identify a substance as a neurotransmitter, the author examined GABA metabolism and synaptic interactions of inhibitory motor neurons in two leech species, Hirudo medicinalis and Haementeria ghilianii. Segmental ganglia of the leech ventral nerve cord and identified inhibitors have the capacity to synthesize GABA when incubated in the presence of the precursor glutamate. Application of GABA to cell bodies of excitatory motor neurons or muscle fibers innervated by the inhibitors hyperpolarizes the membrane potential of the target cell and activates a chloride ion conductance channel, similar to the inhibitory membrane response following intracellular stimulation of the inhibitor. Bicuculline methiodide (5 x 10/sup -5/M), GABA receptor antagonist, blocks reversibly the response to applied GABA and the inhibitory synaptic inputs onto the postsynaptic neurons or muscle fibers without interfering with their excitatory inputs. Furthermore, the inhibitors are included among approximately 25 neurons per segmental ganglion that take up GABA by a high affinity uptake system, as revealed by /sup 3/H-GABA-autoradiography. The development of the capacities to synthesize and to take up GABA were examined in leech embryos. The embryos are able to synthesize GABA at early stages of the development of the nervous system, before any neurons have extended neutrites.

  2. Study on the Effects of Diverting Water into Upper Burnt Pocket, Navigation Pool Number 18, Illinois and A Field Test of the Regression Simulation Model Previously Developed on Navigation Pool Number 8.

    DTIC Science & Technology

    1981-03-01

    earthworms ( Annelida : Oligochaeta). Pages 143-156 in C. W. Hart, Jr. and S. L. H. Fuller, eds. Pollution ecology of freshwater invertebrates...Site, Navigation Pool No. 18, Upper Mississippi River, between 1978 and 1980. NEMATODA round worms ANNELIDA Oligochaeta earth worms Hirudinea leeches

  3. Haematological and immunological characteristics of eastern hellbenders (Cryptobranchus alleganiensis alleganiensis) infected and co-infected with endo- and ectoparasites.

    PubMed

    Hopkins, William A; Fallon, Jesse A; Beck, Michelle L; Coe, Brittney H; Jachowski, Catherine M B

    2016-01-01

    Disease is among the leading causes of the global decline in amphibian populations. In North America, parasites and pathogens are among the factors implicated in precipitous population declines of the giant hellbender salamander (Cryptobranchus alleganiensis), but the incidence of infections and the responses of hellbenders to infections remain poorly studied. Here, we document the prevalence of leech and trypanosome infections in a wild population of eastern hellbenders (Cryptobranchus alleganiensis alleganiensis) and describe haematological and immunological characteristics of hellbenders harbouring these infections. We hypothesized that hellbenders parasitized by trypanosomes would be anaemic, that individuals infected with either or both parasites would exhibit shifts in white blood cell counts and that hellbenders infected with leeches would exhibit altered plasma bactericidal capacity. We found that 24 and 68% of hellbenders in our sample population were infected with leeches and trypanosomes, respectively, and 20% were co-infected with both parasites. We found no evidence suggestive of anaemia among infected individuals. However, hellbenders infected with either or both parasites exhibited marked shifts in circulating white blood cells that were consistent with predictable responses to parasitic infection. Additionally, we found that hellbenders harbouring leeches had much higher plasma bactericidal capacity than individuals without leeches, and we offer multiple potential mechanistic explanations for this observation. We also found evidence that cellular and serological immune responses to parasites were less robust in juvenile than adult hellbenders. This finding warrants further investigation in light of the demographic characteristics, specifically the scarcity of juvenile age classes, of hellbender populations where disease is a possible contributor to declines. Finally, we describe two methodological advances that will improve future studies seeking to

  4. Haematological and immunological characteristics of eastern hellbenders (Cryptobranchus alleganiensis alleganiensis) infected and co-infected with endo- and ectoparasites

    PubMed Central

    Hopkins, William A.; Fallon, Jesse A.; Beck, Michelle L.; Coe, Brittney H.; Jachowski, Catherine M. B.

    2016-01-01

    Disease is among the leading causes of the global decline in amphibian populations. In North America, parasites and pathogens are among the factors implicated in precipitous population declines of the giant hellbender salamander (Cryptobranchus alleganiensis), but the incidence of infections and the responses of hellbenders to infections remain poorly studied. Here, we document the prevalence of leech and trypanosome infections in a wild population of eastern hellbenders (Cryptobranchus alleganiensis alleganiensis) and describe haematological and immunological characteristics of hellbenders harbouring these infections. We hypothesized that hellbenders parasitized by trypanosomes would be anaemic, that individuals infected with either or both parasites would exhibit shifts in white blood cell counts and that hellbenders infected with leeches would exhibit altered plasma bactericidal capacity. We found that 24 and 68% of hellbenders in our sample population were infected with leeches and trypanosomes, respectively, and 20% were co-infected with both parasites. We found no evidence suggestive of anaemia among infected individuals. However, hellbenders infected with either or both parasites exhibited marked shifts in circulating white blood cells that were consistent with predictable responses to parasitic infection. Additionally, we found that hellbenders harbouring leeches had much higher plasma bactericidal capacity than individuals without leeches, and we offer multiple potential mechanistic explanations for this observation. We also found evidence that cellular and serological immune responses to parasites were less robust in juvenile than adult hellbenders. This finding warrants further investigation in light of the demographic characteristics, specifically the scarcity of juvenile age classes, of hellbender populations where disease is a possible contributor to declines. Finally, we describe two methodological advances that will improve future studies seeking to

  5. Cell dialysis by sharp electrodes can cause nonphysiological changes in neuron properties.

    PubMed

    Hooper, Scott L; Thuma, Jeffrey B; Guschlbauer, Christoph; Schmidt, Joachim; Büschges, Ansgar

    2015-08-01

    We recorded from lobster and leech neurons with two sharp electrodes filled with solutions often used with these preparations (lobster: 0.6 M K2SO4 or 2.5 M KAc; leech: 4 M KAc), with solutions approximately matching neuron cytoplasm ion concentrations, and with 6.5 M KAc (lobster, leech) and 0.6 M KAc (lobster). We measured membrane potential, input resistance, and transient and sustained depolarization-activated outward current amplitudes in leech and these neuron properties and hyperpolarization-activated current time constant in lobster, every 10 min for 60 min after electrode penetration. Neuron properties varied with electrode fill. For fills with molarities ≥2.5 M, neuron properties also varied strongly with time after electrode penetration. Depending on the property being examined, these variations could be large. In leech, cell size also increased with noncytoplasmic fills. The changes in neuron properties could be due to the ions being injected from the electrodes during current injection. We tested this possibility in lobster with the 2.5 M KAc electrode fill by making measurements only 10 and 60 min after penetration. Neuron properties still changed, although the changes were less extreme. Making measurements every 2 min showed that the time-dependent variations in neuron properties occurred in concert with each other. Neuron property changes with high molarity electrode-fill solutions were great enough to decrease neuron firing strongly. An experiment with (14)C-glucose electrode fill confirmed earlier work showing substantial leak from sharp electrodes. Sharp electrode work should thus be performed with cytoplasm-matched electrode fills.

  6. Genetic variation in Whitmania pigra, Hirudo nipponica and Poecilobdella manillensis, three endemic and endangered species in China using SSR and TRAP markers.

    PubMed

    Liu, Fei; Guo, Qiao-Sheng; Shi, Hong-Zhuan; Cheng, Bo-Xing; Lu, Yu-Xi; Gou, Ling; Wang, Jia; Shen, Wen-Biao; Yan, Shi-Meng; Wu, Man-Jun

    2016-04-01

    Leeches are not only important medicinal animals worldwide but also are endangered. We aimed to (i) explore the level of genetic diversity within/among populations of three leeches, (ii) assess genetic differentiation among these three leeches, and (iii) discuss an appropriate strategy for conserving leech germplasm. A total of 315 individuals of Whitmania pigra, Hirudo nipponica and Poecilobdella manillensis from 21 populations were collected in China and Vietnam. The genetic structure and genetic diversity among and within the 21 populations were evaluated using target region amplified polymorphism (TRAP) and simple sequence repeat (SSR) markers. Sixteen pairs of TRAP primers generated a total of 398 fragments, of which 396 (99.50%) were polymorphic; fourteen pairs of SSR primers generated a total of 60 fragments, of which 59 (98.33%) were polymorphic. Shannon's index (I) and Nei's gene diversity index (H) for the three leeches were high at the species level (I=0.4980 and H=0.3323 for TRAPs, I=0.4487 and H=0.2969 for SSRs in W. pigra; I=0.4147/0.3769, H=0.2788/0.2566 for H. nipponica; and I=0.4616/0.4717, H=0.3099/0.3203 for P. manillensis). However, low genetic diversity was determined at the population level; the average genetic diversity measures within populations were H=0.1767/0.1376, I=0.2589/0.2043 for W. pigra, H=0.2149/0.2021, I=0.3184/0.3000 for H. nipponica and H=0.2850/0.2724, I=0.4152/0.3967 for P. manillensis. We conclude that there was limited gene exchange within/among populations and species, as the gene flow number (Nm) was 0.5493/0.5807. However, for all three species, the genetic diversity was different at the population level. Gene differentiation (Gst) and Nm were 0.4682 /0.5364 and 0.5678/0.4321 for W. pigra, 0.2294/0.2127 and 1.6797/1.8512 for H. nipponica and 0.1214/0.1496 and 3.6202/2.8412 for P. manillensis. STRUCTURE analysis, Unweighted Pair-Group Method with Arithmetic means (UPGMA) cluster analysis and Principal Coordinates Analysis

  7. Evolutionary Origin of Body Axis Segmentation in Annelids and Arthropods

    NASA Technical Reports Server (NTRS)

    Shankland, S. Martin

    2003-01-01

    During the period of this report, we have made a number of important discoveries. To date this work has led to 4 peer-reviewed publications in primary research journals plus 1 minireview and 1 chapter in the proceedings of a meeting. Publications resulting from this grant support are enumerated at the end of the report. Two additional, on-going studies also described. 1. Using laser cell ablation, we have obtained evidence that an annelid - the leech Helobdella robusta - patterns the anteroposterior (AP) polarity of its nascent segment primordia independent of cell interactions oriented along the AP axis. 2. We cloned a Helobdella homologue (hro-hh) of the Drosophila segment polarity gene hedgehog, and used in situ hybridization and northern blots to characterize its expression in the embryo. 3. We have used laser cell ablations to examine the possible role of cell interactions during the developmental patterning of the 4 rostralmost "head" segments of the leech Helobdella robusta.

  8. Acute toxic effects of two lampricides on twenty-one freshwater invertebrates

    USGS Publications Warehouse

    Rye, Robert P.; King, Everett Louis

    1976-01-01

    We conducted laboratory static bioassays to determine acute toxicity of two lampricides -- a 70% 2-aminoethanol salt of 5,2'dichloro-4'-nitrosalicylanilide (Bayer 73) and a mixture containing 98% 3-trifluoromethyl-4-nitrophenol (TFM) and 2% Bayer 73 (TFM-2B) -- to 21 freshwater invertebrates. LC50 values were determined for 24-h exposure periods at 12.8 C. Organisms relatively sensitive to Bayer 73 were a turbellarian (Dugesia tigrina), aquatic earthworms (Tubifex tubifex and Lumbriculus inconstans), snails (Physa sp.) and (Pleurocera sp.), a clam (Eliptio dilatatus), blackflies (Simulium sp.), leeches (Erpobdellidae), and a daphnid (Daphnia pulex). The invertebrates most sensitive to TFM-2B were turbellarians, aquatic earthworms (Tubifex), snails (Physa), blackflies, leeches, and burrowing mayflies (Hexagenia sp.). Bayer 73 was generally much more toxic to the test organisms than TFM-2B. At lampricidal concentrations, TFM-2B was more highly selective than Bayer 73 against larval sea lampreys (Petromyzon marinus).

  9. A new species of Oceanobdella (Hirudinida: Piscicolidae) from the plain sculpin, Myoxocephalus jaok, from Bristol Bay, Alaska.

    PubMed

    Burreson, Eugene M; Williams, Julianne I

    2004-08-01

    Oceanobdella khani n. sp. is described from the plain sculpin, Myoxocephalus jaok, from Bristol Bay, Alaska, in the eastern Bering Sea. Prevalence was never greater than 10% in any single collection; maximum intensity was 12 leeches per host, but most fish had 5 or fewer leeches. Oceanobdella khani possesses generic characters of small oral sucker, 5 pairs of testisacs, unremarkable terminal male reproductive organs, coelomic system lacking pulsatile vesicles, and 3 pairs of eyes on the oral sucker-trachelosome. Oceanobdella khani is distinguished from other species in the genus by solid black pigmentation on the urosome, clitellum, trachelosome, and most of the oral sucker except for an unpigmented margin. The pigmentation of the caudal sucker is highly variable, ranging from overall mottled blackish gray to completely unpigmented. The caudal sucker lacks ocelli. Intestinal ceca are large, crop ceca are directed anteriorly, and postceca are separate for their entire length.

  10. A review of Biston Leach, 1815 (Lepidoptera, Geometridae, Ennominae) from China, with description of one new species.

    PubMed

    Jiang, Nan; Xue, Dayong; Han, Hongxiang

    2011-01-01

    The genus Biston Leach, 1815 is reviewed for China. Seventeen species are recognized, of which Biston mediolatasp. n. is described. Biston pustulata (Warren, 1896) and Biston panterinariaexanthemata (Moore, 1888) are newly recorded for China. The following new synonyms are established: Biston suppressaria suppressaria (Guenée, 1858) (= Biston suppressaria benescripta (Prout, 1915), syn. n. = Biston luculentus Inoue, 1992 syn. n.); Biston falcata (Warren, 1893) (= Amphidasiserilda Oberthür, 1910, syn. n. = Amphidasis clorinda Oberthür, 1910, syn. n. = Biston emarginaria Leech, 1897, syn. n.); Biston panterinaria panterinaria (Bremer & Grey, 1853) (= Biston panterinaria abraxata (Leech, 1889), syn. n. = Biston panterinaria lienpingensis (Wehrli, 1939), syn. n. = B. panterinaria szechuanensis (Wehrli, 1939), syn. n.). Biston falcata satura (Wehrli,1941), comb. n. is proposed. A key to Chinese Biston and diagnoses for Chinese species are provided. Illustrations of external features and genitalia are presented.

  11. Protein and cholesterol electrophoresis of plasma samples from captive cownose ray (Rhinoptera bonasus).

    PubMed

    Cray, Carolyn; Rodriguez, Marilyn; Field, Cara; McDermott, Alexa; Leppert, Lynda; Clauss, Tonya; Bossart, Gregory D

    2015-11-01

    Our study was undertaken to assess the application of semiautomated methods available at the reference laboratory level for the evaluation of plasma protein and cholesterol via electrophoresis in samples from cownose rays (Rhinoptera bonasus). Three groups of animals were assessed: clinically normal, clinically abnormal, and parasitized with leeches. As reported previously, the albumin band was negligible; the protein electrophoretograms were dominated by a large beta-globulin fraction. While the group of samples from the leech-parasitized rays did not show any large differences, the abnormal group exhibited significantly elevated total solids and cholesterol levels. The latter was related to a significant increase in very low density lipoprotein levels. The results demonstrate the potential application of these laboratory methods in quantitation of plasma proteins and cholesterol fractions in subclass Elasmobranchii.

  12. Fossilized spermatozoa preserved in a 50-Myr-old annelid cocoon from Antarctica

    PubMed Central

    Bomfleur, Benjamin; Mörs, Thomas; Ferraguti, Marco; Reguero, Marcelo A.; McLoughlin, Stephen

    2015-01-01

    The origin and evolution of clitellate annelids—earthworms, leeches and their relatives—is poorly understood, partly because body fossils of these delicate organisms are exceedingly rare. The distinctive egg cases (cocoons) of Clitellata, however, are relatively common in the fossil record, although their potential for phylogenetic studies has remained largely unexplored. Here, we report the remarkable discovery of fossilized spermatozoa preserved within the secreted wall layers of a 50-Myr-old clitellate cocoon from Antarctica, representing the oldest fossil animal sperm yet known. Sperm characters are highly informative for the classification of extant Annelida. The Antarctic fossil spermatozoa have several features that point to affinities with the peculiar, leech-like ‘crayfish worms' (Branchiobdellida). We anticipate that systematic surveys of cocoon fossils coupled with advances in non-destructive analytical methods may open a new window into the evolution of minute, soft-bodied life forms that are otherwise only rarely observed in the fossil record. PMID:26179804

  13. A review of Biston Leach, 1815 (Lepidoptera, Geometridae, Ennominae) from China, with description of one new species

    PubMed Central

    Jiang, Nan; Xue, Dayong; Han, Hongxiang

    2011-01-01

    Abstract The genus Biston Leach, 1815 is reviewed for China. Seventeen species are recognized, of which Biston mediolata sp. n. is described. Biston pustulata (Warren, 1896) and Biston panterinaria exanthemata (Moore, 1888) are newly recorded for China. The following new synonyms are established: Biston suppressaria suppressaria (Guenée, 1858) (= Biston suppressaria benescripta (Prout, 1915), syn. n. = Biston luculentus Inoue, 1992 syn. n.); Biston falcata (Warren, 1893) (= Amphidasis erilda Oberthür, 1910, syn. n. = Amphidasis clorinda Oberthür, 1910, syn. n. = Biston emarginaria Leech, 1897, syn. n.); Biston panterinaria panterinaria (Bremer & Grey, 1853) (= Biston panterinaria abraxata (Leech, 1889), syn. n. = Biston panterinaria lienpingensis (Wehrli, 1939), syn. n. = B. panterinaria szechuanensis (Wehrli, 1939), syn. n.). Biston falcata satura (Wehrli,1941), comb. n. is proposed. A key to Chinese Biston and diagnoses for Chinese species are provided. Illustrations of external features and genitalia are presented. PMID:22259309

  14. Ectoparasites and classification.

    PubMed

    Hopla, C E; Durden, L A; Keirans, J E

    1994-12-01

    The authors present an introductory overview of the principal groups of ectoparasites (flukes, leeches, crustaceans, insects, arachnids, lampreys and vampire bats) associated with domestic animals. Currently-accepted higher-level classifications are outlined for these parasites. Almost all significant ectoparasites of domestic animals are invertebrates, the majority being arthropods (crustaceans, insects and arachnids). Some of these ectoparasites are of particular importance as vectors of pathogens. Many ectoparasite species are host-specific, and vector species typically transmit characteristic pathogens.

  15. Family Practice History: Bloodletting

    PubMed Central

    Curtis, Peter

    1981-01-01

    For 2000 years bloodletting was an accepted form of treatment. During this time, the indications and philosophical basis for lancing, cupping, and the application of leeches evolved in conjunction with advances in anatomy and physiology. In the late 19th century discoveries by tissue pathologists using new diagnostic techniques undermined earlier dogma and bloodletting quickly became a highly suspect form of treatment. ImagesFig. 1 PMID:21289758

  16. Larval stages of Neoplagioporus elongatus (Goto and Ozaki, 1930) (Opecoelidae: Plagioporinae), with notes on potential second intermediate hosts.

    PubMed

    Yano, Ayaka; Urabe, Misako

    2017-04-01

    The morphology of sporocysts and cercariae of Neoplagioporus elongatus (Goto and Ozaki, 1930) is described for the first time. A cotylomicrocercous cercaria obtained from the sorbeoconch snail Semisulcospira nakasekoae was confirmed to be the cercaria of N. elongatus, based on the degree of sequence identity of the COI gene to that of adult worms. Freshwater annelids (oligochaetes and leeches) and some aquatic insects (odonates) were demonstrated experimentally to be potential second intermediate hosts.

  17. Biological Monitoring of Pesticides, Heavy Metals and Other Contaminants at Rocky Mountain Arsenal. Phase 1

    DTIC Science & Technology

    1979-07-01

    herbivorous , while the ground beetle is carnivorous , and both serve as major prey items for insectivorous vertebrates. Leeches and snails are representative...most conspicuous small mammal on RMA and is a strict herbivore that feeds on both above-ground plant parts and roots. The deer mouse is the most abundant...mammal inhabiting RMA. It is widely distributed throughout the Arsenal, but occupies a small home range. It is omnivorous in its food habits, 6 2-4

  18. [Taxonomic diversity of parasites in agnathans and fishes from the Volga River basin. VI. Acanthocephala, Hirudinea and Bivalvia].

    PubMed

    Molodozhnikova, N M; Zhokhov, A E

    2008-01-01

    The checklist of Acanthocephala, Hirudinea, and Bivalvia parasitizing agnathans and fishes in the Volga River basin is presented. Hosts and areas of distribution are indicated for each parasites species. The checklist includes 10 species of acanthocephalans, 7 species of leeches, and 9 species of Bivalvia (at the glochidium stage) from 45 fish species. None of the given parasite species is alien for the Volga River basin.

  19. Sediment Management at the Watershed Level

    DTIC Science & Technology

    2012-08-01

    James R. Leech and David Biedenharn PURPOSE: This Coastal and Hydraulics Engineering Technical Note (CHETN) is an approach to analyze and manage...States (U.S.). The magnitude of this problem is illustrated in the Corps of Engineers ’ final report to Congress for the Streambank Erosion Control...of riverine habitats and ecosystems. This complexity has led some engineers to conclude that treatment of sediment sources at the watershed level

  20. Challenge to Change: Developing Leaders for the Nonkinetic Fight

    DTIC Science & Technology

    2009-06-15

    more of discourse on history. Later, several recognized the end of the presentation was approaching as Goodfriend’s tone shifted and his pace...brigadier general representing the Field Artillery, interjected . “Sir, there are still comments about how IO leeches into public affairs and undermines our...it is coming together. I am most encouraged. The strong network of our communicators and their abilities as a team to shape a public discourse

  1. [Does garlic protect against vampires? An experimental study].

    PubMed

    Sandvik, H; Baerheim, A

    1994-12-10

    Vampires are feared everywhere, but the Balkan region has been especially haunted. Garlic has been regarded as an effective prophylactic against vampires. We wanted to explore this alleged effect experimentally. Owing to the lack of vampires, we used leeches instead. In strictly standardized research surroundings, the leeches were to attach themselves to either a hand smeared with garlic or to a clean hand. The garlic-smeared hand was preferred in two out of three cases (95% confidence interval 50.4% to 80.4%). When they preferred the garlic the leeches used only 14.9 seconds to attach themselves, compared with 44.9 seconds when going to the non-garlic hand (p < 0.05). The traditional belief that garlic has prophylactic properties is probably wrong. The reverse may in fact be true. This study indicates that garlic possibly attracts vampires. Therefore to avoid a Balkan-like development in Norway, restrictions on the use of garlic should be considered.

  2. Differentially Expressed Genes in Hirudo medicinalis Ganglia after Acetyl-L-Carnitine Treatment

    PubMed Central

    Federighi, Giuseppe; Macchi, Monica; Bernardi, Rodolfo; Scuri, Rossana; Brunelli, Marcello; Durante, Mauro; Traina, Giovanna

    2013-01-01

    Acetyl-l-carnitine (ALC) is a naturally occurring substance that, when administered at supra-physiological concentration, is neuroprotective. It is involved in membrane stabilization and in enhancement of mitochondrial functions. It is a molecule of considerable interest for its clinical application in various neural disorders, including Alzheimer’s disease and painful neuropathies. ALC is known to improve the cognitive capability of aged animals chronically treated with the drug and, recently, it has been reported that it impairs forms of non-associative learning in the leech. In the present study the effects of ALC on gene expression have been analyzed in the leech Hirudo medicinalis. The suppression subtractive hybridisation methodology was used for the generation of subtracted cDNA libraries and the subsequent identification of differentially expressed transcripts in the leech nervous system after ALC treatment. The method detects differentially but also little expressed transcripts of genes whose sequence or identity is still unknown. We report that a single administration of ALC is able to modulate positively the expression of genes coding for functions that reveal a lasting effect of ALC on the invertebrate, and confirm the neuroprotective and neuromodulative role of the substance. In addition an important finding is the modulation of genes of vegetal origin. This might be considered an instance of ectosymbiotic mutualism. PMID:23308261

  3. Timing and Scope of Genomic Expansion within Annelida: Evidence from Homeoboxes in the Genome of the Earthworm Eisenia fetida

    PubMed Central

    Zwarycz, Allison S.; Nossa, Carlos W.; Putnam, Nicholas H.; Ryan, Joseph F.

    2016-01-01

    Annelida represents a large and morphologically diverse group of bilaterian organisms. The recently published polychaete and leech genome sequences revealed an equally dynamic range of diversity at the genomic level. The availability of more annelid genomes will allow for the identification of evolutionary genomic events that helped shape the annelid lineage and better understand the diversity within the group. We sequenced and assembled the genome of the common earthworm, Eisenia fetida. As a first pass at understanding the diversity within the group, we classified 363 earthworm homeoboxes and compared them with those of the leech Helobdella robusta and the polychaete Capitella teleta. We inferred many gene expansions occurring in the lineage connecting the most recent common ancestor (MRCA) of Capitella and Eisenia to the Eisenia/Helobdella MRCA. Likewise, the lineage leading from the Eisenia/Helobdella MRCA to the leech H. robusta has experienced substantial gains and losses. However, the lineage leading from Eisenia/Helobdella MRCA to E. fetida is characterized by extraordinary levels of homeobox gain. The evolutionary dynamics observed in the homeoboxes of these lineages are very likely to be generalizable to all genes. These genome expansions and losses have likely contributed to the remarkable biology exhibited in this group. These results provide a new perspective from which to understand the diversity within these lineages, show the utility of sub-draft genome assemblies for understanding genomic evolution, and provide a critical resource from which the biology of these animals can be studied. PMID:26659921

  4. Compensatory plasticity restores locomotion after chronic removal of descending projections

    PubMed Central

    Harley, Cynthia M.; Reilly, Melissa G.; Stewart, Christopher; Schlegel, Chantel; Morley, Emma; Puhl, Joshua G.; Nagel, Christian; Crisp, Kevin M.

    2015-01-01

    Homeostatic plasticity is an important attribute of neurons and their networks, enabling functional recovery after perturbation. Furthermore, the directed nature of this plasticity may hold a key to the restoration of locomotion after spinal cord injury. Here we studied the recovery of crawling in the leech Hirudo verbana after descending cephalic fibers were surgically separated from crawl central pattern generators shown previously to be regulated by dopamine. We observed that immediately after nerve cord transection leeches were unable to crawl, but remarkably, after a day to weeks, animals began to show elements of crawling and intersegmental coordination. Over a similar time course, excessive swimming due to the loss of descending inhibition returned to control levels. Additionally, removal of the brain did not prevent crawl recovery, indicating that connectivity of severed descending neurons was not essential. After crawl recovery, a subset of animals received a second transection immediately below the anterior-most ganglion remaining. Similar to their initial transection, a loss of crawling with subsequent recovery was observed. These data, in recovered individuals, support the idea that compensatory plasticity directly below the site of injury is essential for the initiation and coordination of crawling. We maintain that the leech provides a valuable model to understand the neural mechanisms underlying locomotor recovery after injury because of its experimental accessibility, segmental organization, and dependence on higher-order control involved in the initiation, modulation, and coordination of locomotor behavior. PMID:25787951

  5. Artery-Only Ear Replantation in a Child: A Case Report With Daily Photographic Documentation.

    PubMed

    Mendenhall, Shaun D; Sawyer, Justin D; Adkinson, Joshua M

    2016-01-01

    Objective: Ear replantation poses a significant technical challenge even for the skilled microsurgeon. Many ear amputations result from avulsion and thus have damaged and often diminutive vessels with a paucity of veins. Artery-only replantation is an option for ear salvage, but little is published on the clinical course and appearance after this procedure. Methods: A subtotal ear replantation was performed on a 10-year-old boy without a venous anastomosis. Leech therapy was used to manage venous congestion postoperatively, and daily photography was performed to document the clinical course. Results: Postoperative venous congestion was successfully managed with leech therapy. Four days after the replantation, arterial thrombosis occurred that required a take back and salvage with an interposition vein graft for arterial repair. Native venous drainage and arterial revascularization from skin edges were evident by postoperative day 12, and leeches were discontinued on day 14. The patient required debridement of the posterior ear and superior helix necrotic skin, with burying of the upper portion of the ear in a superior auricular skin flap. The ear was subsequently released from the head, and the exposed portions were covered successfully with a full-thickness skin graft. Conclusions: While arterial and venous anastomoses should always be attempted, arterial-only ear replantation can provide excellent results when venous congestion is properly managed. Daily photography can be a useful tool to monitor subtle skin color changes that may indicate native venous drainage and arterial revascularization.

  6. Artery-Only Ear Replantation in a Child: A Case Report With Daily Photographic Documentation

    PubMed Central

    Mendenhall, Shaun D.; Sawyer, Justin D.

    2016-01-01

    Objective: Ear replantation poses a significant technical challenge even for the skilled microsurgeon. Many ear amputations result from avulsion and thus have damaged and often diminutive vessels with a paucity of veins. Artery-only replantation is an option for ear salvage, but little is published on the clinical course and appearance after this procedure. Methods: A subtotal ear replantation was performed on a 10-year-old boy without a venous anastomosis. Leech therapy was used to manage venous congestion postoperatively, and daily photography was performed to document the clinical course. Results: Postoperative venous congestion was successfully managed with leech therapy. Four days after the replantation, arterial thrombosis occurred that required a take back and salvage with an interposition vein graft for arterial repair. Native venous drainage and arterial revascularization from skin edges were evident by postoperative day 12, and leeches were discontinued on day 14. The patient required debridement of the posterior ear and superior helix necrotic skin, with burying of the upper portion of the ear in a superior auricular skin flap. The ear was subsequently released from the head, and the exposed portions were covered successfully with a full-thickness skin graft. Conclusions: While arterial and venous anastomoses should always be attempted, arterial-only ear replantation can provide excellent results when venous congestion is properly managed. Daily photography can be a useful tool to monitor subtle skin color changes that may indicate native venous drainage and arterial revascularization. PMID:28101290

  7. Timing and Scope of Genomic Expansion within Annelida: Evidence from Homeoboxes in the Genome of the Earthworm Eisenia fetida.

    PubMed

    Zwarycz, Allison S; Nossa, Carlos W; Putnam, Nicholas H; Ryan, Joseph F

    2015-12-10

    Annelida represents a large and morphologically diverse group of bilaterian organisms. The recently published polychaete and leech genome sequences revealed an equally dynamic range of diversity at the genomic level. The availability of more annelid genomes will allow for the identification of evolutionary genomic events that helped shape the annelid lineage and better understand the diversity within the group. We sequenced and assembled the genome of the common earthworm, Eisenia fetida. As a first pass at understanding the diversity within the group, we classified 363 earthworm homeoboxes and compared them with those of the leech Helobdella robusta and the polychaete Capitella teleta. We inferred many gene expansions occurring in the lineage connecting the most recent common ancestor (MRCA) of Capitella and Eisenia to the Eisenia/Helobdella MRCA. Likewise, the lineage leading from the Eisenia/Helobdella MRCA to the leech H. robusta has experienced substantial gains and losses. However, the lineage leading from Eisenia/Helobdella MRCA to E. fetida is characterized by extraordinary levels of homeobox gain. The evolutionary dynamics observed in the homeoboxes of these lineages are very likely to be generalizable to all genes. These genome expansions and losses have likely contributed to the remarkable biology exhibited in this group. These results provide a new perspective from which to understand the diversity within these lineages, show the utility of sub-draft genome assemblies for understanding genomic evolution, and provide a critical resource from which the biology of these animals can be studied.

  8. Real-time biomimetic Central Pattern Generators in an FPGA for hybrid experiments

    PubMed Central

    Ambroise, Matthieu; Levi, Timothée; Joucla, Sébastien; Yvert, Blaise; Saïghi, Sylvain

    2013-01-01

    This investigation of the leech heartbeat neural network system led to the development of a low resources, real-time, biomimetic digital hardware for use in hybrid experiments. The leech heartbeat neural network is one of the simplest central pattern generators (CPG). In biology, CPG provide the rhythmic bursts of spikes that form the basis for all muscle contraction orders (heartbeat) and locomotion (walking, running, etc.). The leech neural network system was previously investigated and this CPG formalized in the Hodgkin–Huxley neural model (HH), the most complex devised to date. However, the resources required for a neural model are proportional to its complexity. In response to this issue, this article describes a biomimetic implementation of a network of 240 CPGs in an FPGA (Field Programmable Gate Array), using a simple model (Izhikevich) and proposes a new synapse model: activity-dependent depression synapse. The network implementation architecture operates on a single computation core. This digital system works in real-time, requires few resources, and has the same bursting activity behavior as the complex model. The implementation of this CPG was initially validated by comparing it with a simulation of the complex model. Its activity was then matched with pharmacological data from the rat spinal cord activity. This digital system opens the way for future hybrid experiments and represents an important step toward hybridization of biological tissue and artificial neural networks. This CPG network is also likely to be useful for mimicking the locomotion activity of various animals and developing hybrid experiments for neuroprosthesis development. PMID:24319408

  9. Complex Evolutionary History of the Aeromonas veronii Group Revealed by Host Interaction and DNA Sequence Data

    PubMed Central

    Faucher, Joshua; Horneman, Amy J.; Gogarten, J. Peter; Graf, Joerg

    2011-01-01

    Aeromonas veronii biovar sobria, Aeromonas veronii biovar veronii, and Aeromonas allosaccharophila are a closely related group of organisms, the Aeromonas veronii Group, that inhabit a wide range of host animals as a symbiont or pathogen. In this study, the ability of various strains to colonize the medicinal leech as a model for beneficial symbiosis and to kill wax worm larvae as a model for virulence was determined. Isolates cultured from the leech out-competed other strains in the leech model, while most strains were virulent in the wax worms. Three housekeeping genes, recA, dnaJ and gyrB, the gene encoding chitinase, chiA, and four loci associated with the type three secretion system, ascV, ascFG, aexT, and aexU were sequenced. The phylogenetic reconstruction failed to produce one consensus tree that was compatible with most of the individual genes. The Approximately Unbiased test and the Genetic Algorithm for Recombination Detection both provided further support for differing evolutionary histories among this group of genes. Two contrasting tests detected recombination within aexU, ascFG, ascV, dnaJ, and gyrB but not in aexT or chiA. Quartet decomposition analysis indicated a complex recent evolutionary history for these strains with a high frequency of horizontal gene transfer between several but not among all strains. In this study we demonstrate that at least for some strains, horizontal gene transfer occurs at a sufficient frequency to blur the signal from vertically inherited genes, despite strains being adapted to distinct niches. Simply increasing the number of genes included in the analysis is unlikely to overcome this challenge in organisms that occupy multiple niches and can exchange DNA between strains specialized to different niches. Instead, the detection of genes critical in the adaptation to specific niches may help to reveal the physiological specialization of these strains. PMID:21359176

  10. Complex evolutionary history of the Aeromonas veronii group revealed by host interaction and DNA sequence data.

    PubMed

    Silver, Adam C; Williams, David; Faucher, Joshua; Horneman, Amy J; Gogarten, J Peter; Graf, Joerg

    2011-02-16

    Aeromonas veronii biovar sobria, Aeromonas veronii biovar veronii, and Aeromonas allosaccharophila are a closely related group of organisms, the Aeromonas veronii Group, that inhabit a wide range of host animals as a symbiont or pathogen. In this study, the ability of various strains to colonize the medicinal leech as a model for beneficial symbiosis and to kill wax worm larvae as a model for virulence was determined. Isolates cultured from the leech out-competed other strains in the leech model, while most strains were virulent in the wax worms. Three housekeeping genes, recA, dnaJ and gyrB, the gene encoding chitinase, chiA, and four loci associated with the type three secretion system, ascV, ascFG, aexT, and aexU were sequenced. The phylogenetic reconstruction failed to produce one consensus tree that was compatible with most of the individual genes. The Approximately Unbiased test and the Genetic Algorithm for Recombination Detection both provided further support for differing evolutionary histories among this group of genes. Two contrasting tests detected recombination within aexU, ascFG, ascV, dnaJ, and gyrB but not in aexT or chiA. Quartet decomposition analysis indicated a complex recent evolutionary history for these strains with a high frequency of horizontal gene transfer between several but not among all strains. In this study we demonstrate that at least for some strains, horizontal gene transfer occurs at a sufficient frequency to blur the signal from vertically inherited genes, despite strains being adapted to distinct niches. Simply increasing the number of genes included in the analysis is unlikely to overcome this challenge in organisms that occupy multiple niches and can exchange DNA between strains specialized to different niches. Instead, the detection of genes critical in the adaptation to specific niches may help to reveal the physiological specialization of these strains.

  11. Real-time biomimetic Central Pattern Generators in an FPGA for hybrid experiments.

    PubMed

    Ambroise, Matthieu; Levi, Timothée; Joucla, Sébastien; Yvert, Blaise; Saïghi, Sylvain

    2013-01-01

    This investigation of the leech heartbeat neural network system led to the development of a low resources, real-time, biomimetic digital hardware for use in hybrid experiments. The leech heartbeat neural network is one of the simplest central pattern generators (CPG). In biology, CPG provide the rhythmic bursts of spikes that form the basis for all muscle contraction orders (heartbeat) and locomotion (walking, running, etc.). The leech neural network system was previously investigated and this CPG formalized in the Hodgkin-Huxley neural model (HH), the most complex devised to date. However, the resources required for a neural model are proportional to its complexity. In response to this issue, this article describes a biomimetic implementation of a network of 240 CPGs in an FPGA (Field Programmable Gate Array), using a simple model (Izhikevich) and proposes a new synapse model: activity-dependent depression synapse. The network implementation architecture operates on a single computation core. This digital system works in real-time, requires few resources, and has the same bursting activity behavior as the complex model. The implementation of this CPG was initially validated by comparing it with a simulation of the complex model. Its activity was then matched with pharmacological data from the rat spinal cord activity. This digital system opens the way for future hybrid experiments and represents an important step toward hybridization of biological tissue and artificial neural networks. This CPG network is also likely to be useful for mimicking the locomotion activity of various animals and developing hybrid experiments for neuroprosthesis development.

  12. Unusual foreign body in the larynx: a bee.

    PubMed

    İlhan, Ethem; Yaman, Handan; Dost, Burhan; Köse, Gökçe Akman; Yaman, Hüseyin

    2015-01-01

    Foreign body lodgement in the larynx is a rare situation. Our review of the literature revealed no living foreign body in larynx except for laryngeal leeches and anisakiasis. In this article, we report a patient with unusual laryngeal foreign body lodgement: a bee which presented with sudden odynophagia and stinging sensation in throat. The bee was detected on the laryngeal mucosa in indirect laryngoscopic examination and removed immediately under general anesthesia in apneic period. In this case report, we describe the importance of detailed anamnesis and laryngeal examination even if the patient has no severe symptoms.

  13. The biology of some intraerythrocytic parasites of fishes, amphibia and reptiles.

    PubMed

    Davies, A J; Johnston, M R

    2000-01-01

    Fishes, amphibia and reptiles, the ectothermic vertebrates, are hosts for a variety of intraerythrocytic parasites including protists, prokaryotes, viruses and structures of uncertain status. These parasites may experience host temperature fluctuations, host reproductive strategies, population genetics, host habitat and migratory behaviour quite unlike those of endothermic hosts. Few blood infections of fishes, amphibia and reptiles have proven pathogenicity, in contrast to the many intraerythrocytic parasites of mammals and some birds which harm their hosts. Although not given the attention afforded to intraerythrocytic parasites of endotherms, those of ectotherms have been studied for more than a century. This review reports on the diversity, general biology and phylogeny of intraerythrocytic parasites of ectotherms. The existence of taxonomic confusion is emphasized and the main taxonomic features of most of the 23 better characterized genera, particularly the kinetoplastid and apicomplexan protists, are summarized. Transmission of protistan infections of aquatic ectotherms is also discussed. Leeches can transfer sporozoties or merozoites to the vertebrate host during feeding. Dormant sporozoites of Lankesterella may permit transmission of species of this genus between vertebrates by predation. The fish haemogregarine, Haemogregarina bigemina, probably has gnathiid isopods, rather than leeches, as its definitive hosts. Hepatozoon spp. in aquatic hosts, and Progarnia of caiman, may also use invertebrate hosts other than leeches. Protistan infections of terrestrial or semi-terrestrial hosts are transmitted by a variety of arthropods, or, in some cases, leeches, contaminated paratenic hosts, or sporocysts free in water. Transfer of protists between vertebrates by predation and congenitally may also occur. The biology of the host cells of these infections, the red blood cells of ectotherm vertebrates, is summarized and compared with that of mammalian erythrocytes

  14. Interpretative Analysis of Surficial Sediments as an Aid in Transport Studies of Dredged Materials Cape Canaveral, Florida.

    DTIC Science & Technology

    1984-03-01

    of Cocoa leech, nornda, to 40-55 ft of uster, on the inner continental shelf. Drefte isposal material io composed of clay, silt, ad fine send remved...of Cape Canaveral and 4.5 miles east of Cocoa Beach, Florida (Site B, Figure 1), has been in use since 1974. During the past 9 years, approximately...and direction diagrams, calculated for Cocoa Beach for the 10-year period (1945-1947 and 1950-1958), were located on project plansheets (SM 1979). A

  15. Corrections to the theory and the optimal line in the swimming diagram of Taylor (1952).

    PubMed

    Humphrey, Joseph A C; Chen, Jun; Iwasaki, Tetsuya; Friesen, W Otto

    2010-08-06

    The analysis of undulatory swimming gaits requires knowledge of the fluid forces acting on the animal body during swimming. In his classical 1952 paper, Taylor analysed this problem using a 'resistive-force' theory. The theory was used to characterize the undulatory gaits that result in the smallest energy dissipation to the fluid for a given swim velocity. The optimal gaits thus found were compared with data recorded from movies of a snake and a leech swimming. This report identifies and corrects a mathematical error in Taylor's paper, showing that his theory applies even better to animals of circular cross section.

  16. First record of a digenean from invasive lionfish, Pterois cf. volitans, (Scorpaeniformes: Scorpaenidae) in the northwestern Atlantic Ocean.

    PubMed

    Bullard, S A; Barse, A M; Curran, S S; Morris, J A

    2011-10-01

    Adults of Lecithochirium floridense (Digenea: Hemiuridae) parasitized the stomach in each of 22 necropsied lionfish, Pterois cf. volitans (Scorpaeniformes: Scorpaenidae) (prevalence  =  100%, mean intensity  =  11), captured in the northwestern Atlantic Ocean off Beaufort, North Carolina (34°14.83'N, 76°35.25'W). This is the first report of a digenean from the invasive lionfish and that of L. floridense from a species of Pterois. The leech specimen previously identified as Myzobdella lugubris from P. volitans in the northwestern Atlantic Ocean is re-identified as Trachelobdella lubrica based on a study of the original voucher specimen.

  17. Beauty and the beast: Superconformal symmetry in a monster module

    NASA Astrophysics Data System (ADS)

    Dixon, L.; Ginsparg, P.; Harvey, J.

    1988-06-01

    Frenkel, Lepowsky, and Meurman have constructed a representation of the largest sporadic simple finite group, the Fischer-Griess monster, as the automorphism group of the operator product algebra of a conformal field theory with central charge c=24. In string terminology, their construction corresponds to compactification on a Z 2 asymmetric orbifold constructed from the torus R 24/∧, where ∧ is the Leech lattice. In this note we point out that their construction naturally embodies as well a larger algebraic structure, namely a super-Virasoro algebra with central charge ĉ=16, with the supersymmetry generator constructed in terms of bosonic twist fields.

  18. Genetic Regulatory Networks in Embryogenesis and Evolution

    NASA Technical Reports Server (NTRS)

    1998-01-01

    The article introduces a series of papers that were originally presented at a workshop titled Genetic Regulatory Network in Embryogenesis and Evaluation. Contents include the following: evolution of cleavage programs in relationship to axial specification and body plan evolution, changes in cell lineage specification elucidate evolutionary relations in spiralia, axial patterning in the leech: developmental mechanisms and evolutionary implications, hox genes in arthropod development and evolution, heterochronic genes in development and evolution, a common theme for LIM homeobox gene function across phylogeny, and mechanisms of specification in ascidian embryos.

  19. HmCRIP, a cysteine-rich intestinal protein, is expressed by an identified regenerating nerve cell.

    PubMed

    Emes, R D; Wang, W-Z; Lanary, K; Blackshaw, S E

    2003-01-02

    A Hirudo medicinalis cDNA isolated from regenerating CNS tissue at 24 h post-axotomy was identified as a leech homologue of the mammalian cysteine-rich intestinal proteins (CRIPs) and named HmCRIP. HmCRIP is up-regulated within 6 h of axotomy, peaking at 24 h. This is the first demonstration of a CRIP homologue in regenerating CNS and in a serotonergic neurone. In rodents CRIP is an important factor in the regulation of the inflammatory immune response through control of Th1/Th2 differentiation. The role of HmCRIP in the regeneration competent environment of the annelid central nervous system is discussed.

  20. Synchronization Patterns and Related Problems in Combinatorial Analysis and Graph Theory

    DTIC Science & Technology

    1981-06-01

    APPENDIX 86 REFERENCES 90 Li ~1 ivF LIST OF FIGURES Figure Page 1-1 The Leech Tree 6 2-1 The Graph L and the Graph R 9 2-2 The Dodecahedron and Two...forest F with 4 nodes, but in this case Ithe direct count to find the number takes more work. D Figure 2-2. The Dodecahedron and Two Copies of the...with n - 2m nodes, girth > 4, and d - 3, then G m - 2 Om-4) T -(Zm 3 24m + 100m 147). The dodecahedron , D, and one graph, P, consisting of two copies

  1. Behavioral studies of contaminant effects on aquatic invertebrates: A review of Russian investigations

    USGS Publications Warehouse

    Nepomnyashchikh, V. A.; DeLonay, V. A.; Little, E.E.; Henshel, D. S.; Bengston, David A.

    1996-01-01

    Studies by Russian scientists have documented significant alterations and impairment of critical behavioral functions in aquatic organisms following exposure to environmental contaminants. Behavioral responses disrupted by sublethal exposure to toxicants are intimately involved in habitat selection, foraging, competition, predator-prey relationships, and reproduction, and are essential to survival. Behavioral responses of benthic invertebrates have received considerable study in Russia. A range of invertebrate taxa have been studied, including leeches, insects, molluscs, plankton, and crustaceans. In addition, aquatic invertebrates exhibit a large number of behavioral responses which are sensitive to contaminant exposure and are easily quantified. Standardized behavioral methodologies for measuring contaminant effects are being developed.

  2. Technical Basis for Flood Protection at Nuclear Power Plants

    DTIC Science & Technology

    2015-07-01

    ER D C/ CH L SR -1 5- 3 Technical Basis for Flood Protection at Nuclear Power Plants Co as ta l a nd H yd ra ul ic s La bo ra to ry...2015 Technical Basis for Flood Protection at Nuclear Power Plants James R. Leech, Loren L. Wehmeyer, David A. Margo, Landris T. Lee, Aaron R. Byrd...39180-6199 ERDC/CHL SR-15-3 ii Abstract Current flood- protection regulatory guidance for nuclear power plants is contained in the Regulatory Guide

  3. Bioactive proteins and peptides isolated from Chinese medicines with pharmaceutical potential

    PubMed Central

    2014-01-01

    Some protein pharmaceuticals from Chinese medicine have been developed to treat cardiovascular diseases, genetic diseases, and cancer. Bioactive proteins with various pharmacological properties have been successfully isolated from animals such as Hirudo medicinalis (medicinal leech), Eisenia fetida (earthworm), and Mesobuthus martensii (Chinese scorpion), and from herbal medicines derived from species such as Cordyceps militaris, Ganoderma, Momordica cochinchinensis, Viscum album, Poria cocos, Senna obtusifolia, Panax notoginseng, Smilax glabra, Ginkgo biloba, Dioscorea batatas, and Trichosanthes kirilowii. This article reviews the isolation methods, molecular characteristics, bioactivities, pharmacological properties, and potential uses of bioactive proteins originating from these Chinese medicines. PMID:25067942

  4. Examination of interaction of trypanosome infection and crude oil exposure on hematology of the longhorn sculpin (Myoxocephalus octodecemspinosus)

    SciTech Connect

    Kiceniuk, J.W.; Khan, R.A.; Dawe, M.; Williams, U.

    1982-04-01

    Adult longhorn sculpins were collected from Conception Bay, Newfoundland, and infected with trypanosomes via leeches. One group of these fish were exposed to water-accommodated Venezuelan crude oil, while the other served as controls. The results of the study suggests that water soluble fractions of Venezuelan crude oil have a minor effect on the hematology of sculpins in the concentration range 150-300 ppb, but that trypanosomes appear to potentiate the effect of oil on blood hemoglobin content of trypanosome infected fish. If this is found to be the case in active species of fish, the decrease in oxygen carrying capacity would likely limit the aerobic capacity of fish. (JMT)

  5. Clifford Algebras and Their Decomposition into Conjugate Fermionic Heisenberg Algebras

    NASA Astrophysics Data System (ADS)

    Catto, Sultan; Gürcan, Yasemin; Khalfan, Amish; Kurt, Levent; Kato La, V.

    2016-10-01

    We discuss a construction scheme for Clifford numbers of arbitrary dimension. The scheme is based upon performing direct products of the Pauli spin and identity matrices. Conjugate fermionic algebras can then be formed by considering linear combinations of the Clifford numbers and the Hermitian conjugates of such combinations. Fermionic algebras are important in investigating systems that follow Fermi-Dirac statistics. We will further comment on the applications of Clifford algebras to Fueter analyticity, twistors, color algebras, M-theory and Leech lattice as well as unification of ancient and modern geometries through them.

  6. Neuroelectronic device based on nanocoax arrays

    NASA Astrophysics Data System (ADS)

    Naughton, Jeffrey R.; Lundberg, Jaclyn N.; Varela, Juan A.; Burns, Michael J.; Chiles, Thomas C.; Christianson, John P.; Naughton, Michael J.

    2015-03-01

    We report on development of a nanocoax-based neuroelectronic array. The device has been used in real time to noninvasively couple to a ganglion sac located along the main nerve cord of the leech Hirudo medicinalis. This allowed for extracellular recording of synaptic activity in the form of spontaneous synapse firing in pre- and post-synaptic somata, with the next target being recording of local field potentials from rat hippocampal cells. We also discuss an alteration of the architecture to facilitate optical integration of the nanoarray, toward utilizing the so-modified device to elicit / inhibit action potentials in optogenetically-modified cells.

  7. Toll-like receptor genes (TLRs) from Capitella capitata and Helobdella robusta (Annelida).

    PubMed

    Davidson, Charis R; Best, Natalie M; Francis, Joseph W; Cooper, Edwin L; Wood, Todd Charles

    2008-01-01

    Toll-like receptors (TLRs) are an important part of the innate immunity system and are found throughout the animal kingdom, but have not yet been reported in annelids. We searched shotgun reads of the genomes of the leech Helobdella and polychaete Capitella for TLR homologs. We found 105 TLR homologs in Capitella and 16 in Helobdella. The deduced phylogeny of these sequences, together with TLRs from other animal phyla, reveals three major clades. One clade consists of a mixture of both vertebrates and invertebrates, including sequences from Capitella and Helobdella, while the other two clades contain only invertebrate TLRs.

  8. Automated video analysis of animal movements using Gabor orientation filters.

    PubMed

    Wagenaar, Daniel A; Kristan, Wiliam B

    2010-03-01

    To quantify locomotory behavior, tools for determining the location and shape of an animal's body are a first requirement. Video recording is a convenient technology to store raw movement data, but extracting body coordinates from video recordings is a nontrivial task. The algorithm described in this paper solves this task for videos of leeches or other quasi-linear animals in a manner inspired by the mammalian visual processing system: the video frames are fed through a bank of Gabor filters, which locally detect segments of the animal at a particular orientation. The algorithm assumes that the image location with maximal filter output lies on the animal's body and traces its shape out in both directions from there. The algorithm successfully extracted location and shape information from video clips of swimming leeches, as well as from still photographs of swimming and crawling snakes. A Matlab implementation with a graphical user interface is available online, and should make this algorithm conveniently usable in many other contexts.

  9. Recombinant decorsin: dynamics of the RGD recognition site.

    PubMed Central

    Krezel, A. M.; Ulmer, J. S.; Wagner, G.; Lazarus, R. A.

    2000-01-01

    Decorsin is an antagonist of integrin alphaIIbbeta3 and a potent platelet aggregation inhibitor. A synthetic gene encoding decorsin, originally isolated from the leech Macrobdella decora, was designed, constructed, and expressed in Escherichia coli. The synthetic gene was fused to the stII signal sequence and expressed under the transcriptional control of the E. coli alkaline phosphatase promoter. The protein was purified by size-exclusion filtration of the periplasmic contents followed by reversed-phase high-performance liquid chromatography. Purified recombinant decorsin was found to be indistinguishable from leech-derived decorsin based on amino acid composition, mass spectral analysis, and biological activity assays. Complete sequential assignments of 1H and proton bound 13C resonances were established. Stereospecific assignments of 21 of 25 nondegenerate b-methylene groups were determined. The RGD adhesion site recognized by integrin receptors was found at the apex of a most exposed hairpin loop. The dynamic behavior of decorsin was analyzed using several independent NMR parameters. Although the loop containing the RGD sequence is the most flexible one in decorsin, the conformation of the RGD site itself is more restricted than in other proteins with similar activities. PMID:10975565

  10. Therapeutic Response for Functional Abdominal Pain in Children with Occult Constipation: Laxatives versus Prokinetic Drugs

    PubMed Central

    2017-01-01

    The relationship between functional abdominal pain (FAP) and occult constipation (OC) in children who did not meet the Rome III criteria for constipation has rarely been reported. This study aimed to estimate the prevalence of OC in patients with FAP and to compare the effectiveness of prokinetic drugs and laxatives for FAP and OC. Pediatric outpatients (n = 212; aged 4–15 years) who satisfied the Rome III criteria for childhood FAP were divided into 2 groups based on Leech scores: group 1 < 8; group 2 ≥ 8. Group 2 received either prokinetic drugs or laxatives and pain severity was assessed after 2 weeks, 1 month, and 3 months. A total 52.4% (111/212) of patients had OC in this study. More patients who received laxatives had reduced pain scores compared with those who received prokinetic drugs. Those treated with laxatives in group 2 had a better response than those treated with prokinetic drugs throughout the study period (P < 0.001, P < 0.001, and P = 0.002 after 2 weeks, 1 month, and 3 months, respectively). OC was frequently encountered in children with FAP. Laxatives can be more effective than prokinetic drugs for relieving symptoms of FAP in children with a Leech score ≥ 8 and suspected OC. PMID:27914138

  11. Emergent Space-Time

    NASA Astrophysics Data System (ADS)

    Chapline, George

    It has been shown that a nonlinear Schrödinger equation in 2+1 dimensions equipped with an SU(N) Chern-Simons gauge field can provide an exact description of certain self-dual Einstein spaces in the limit N-=∞. Ricci flat Einstein spaces can then be viewed as arising from a quantum pairing of the classical self-dual and anti-self-dual solutions. In this chapter, we will outline how this theory of empty space-time might be generalized to include matter and vacuum energy by transplanting the nonlinear Schrödinger equation used to construct Einstein spaces to the 25+1-dimensional Lorentzian Leech lattice. If the distinguished 2 spatial dimensions underlying the construction of Einstein spaces are identified with a hexagonal lattice section of the Leech lattice, the wave-function becomes an 11 × 11 matrix that can represent fermion and boson degrees of freedom (DOF) associated with 2-form and Yang-Mills gauge symmetries. The resulting theory of gravity and matter in 3+1 dimensions is not supersymmetric, which provides an entry for a vacuum energy. Indeed, in the case of a Lemaitre cosmological model, the emergent space-time will naturally have a vacuum energy on the order of the observed cosmological constant.

  12. Phenotypically plastic responses of green frog embryos to conflicting predation risk.

    PubMed

    Ireland, D H; Wirsing, A J; Murray, D L

    2007-05-01

    Predators have been shown to alter the timing of switch points between life history stages, but few studies have addressed switch point plasticity in prey exposed simultaneously to conflicting predation pressure. We tested hatching responses of green frog (Rana clamitans) embryos subject to perceived predation risk from chemical cues released by two stage-specific predators, predicting that these predators would elicit: (1) directional hatching responses when presented independently, and (2) intermediate phenotypic responses when presented simultaneously. R. clamitans embryos in outdoor exclosures were exposed to cues from an egg predator (freshwater leeches; Nephelopsis obscura), a larval predator (dragonfly nymphs, Aeschna canadensis), and both predators in a 2 x 2 factorial experiment, and changes in hatchling size, hatchling developmental stage, and hatching time were compared to those for control embryos. Leeches alone induced embryos to hatch at a smaller size and an earlier developmental stage than controls, while dragonfly nymphs elicited a delay in egg hatching time that was associated with larger size and later developmental stage at hatching. Embryos failed to respond to simultaneous exposure to both predators, implying that responses to each occurred concurrently and were therefore dampened. Our results indicate that prey under threat from conflicting predators may manifest intermediate defensive phenotypes. Such intermediate responses may result in elevated rates of prey mortality with possible consequences at the population level.

  13. Rhopalobdella japonica n. gen., n. sp. (Hirudinea, Piscicolidae) from Dasyatis akajei (Chondrichthyes: Dasyatididae) in the northwestern Pacific.

    PubMed

    Burreson, E M; Kearn, G C

    2000-08-01

    A new genus and species of piscicolid leech in the Platybdellinae inhabits the oral cavity of Dasyatis akajei in the northwestern Pacific Ocean near Tanabe, Japan. The genus Rhopalobdella n. gen. is characterized externally by very small oral and caudal suckers and a smooth body that is widest just posterior to the clitellum. Eyespots and ocelli are lacking. The coelom is spacious with large segmental connecting sinuses between dorsal and ventral sinuses. There are 5 pairs of testisacs, an unusually extensive epididymis, and a very large bursa. Conducting tissue is absent. There are 2 pairs of esophageal diverticula and very well developed nephridia. Rhopalobdella japonica n. gen. n. sp. is characterized by a urosome that tapers strongly to the caudal sucker and by a single gonopore; the common oviduct opens into the posterior portion of the bursa. The coelomic and excretory systems resemble Aestabdella, but in other respects the genera are quite different. This is the first marine leech reported from rays in the northwestern Pacific.

  14. Effects of high-rate electrical stimulation upon firing in modelled and real neurons.

    PubMed

    Krauthamer, V; Crosheck, T

    2002-05-01

    Many medical devices use high-rate, low-amplitude currents to affect neural function. This study examined the effect of stimulation rate upon action potential threshold and sustained firing rate for two model neurons, the rabbit myelinated fibre and the unmyelinated leech touch sensory cell. These model neurons were constructed with the NEURON simulator from electrophysiological data. Alternating-phase current pulses (0-1250 Hz), of fixed phase duration (0.2 ms), were used to stimulate the neurons, and propagation success or failure was measured. One effect of the high pulse rates was to cause a net depolarisation, and this was verified by the relief of action potential conduction block by 500 Hz extracellular stimulation in leech neurons. The models also predicted that the neurons would maintain maximum sustained firing at a number of different stimulation rates. For example, at twice threshold, the myelinated model followed the stimulus up to 500 Hz stimulation, half the stimulus rate up to 850 Hz stimulation, and it did not fire at 1250 Hz stimulation. By contrast, the unmyelinated neuron model had a lower maximum firing rate of 190 Hz, and this rate was obtained at a number of stimulation rates, up to 1250 Hz. The myelinated model also predicted sustained firing with 1240 Hz stimulation at threshold current, but no firing when the current level was doubled. Most of these effects are explained by the interaction of stimulus pulses with the cell's refractory period.

  15. Control of traveling-wave oscillations and bifurcation behavior in central pattern generators

    NASA Astrophysics Data System (ADS)

    Landsman, Alexandra S.; Slotine, Jean-Jacques

    2012-10-01

    Understanding synchronous and traveling-wave oscillations, particularly as they relate to transitions between different types of behavior, is a central problem in modeling biological systems. Here, we address this problem in the context of central pattern generators (CPGs). We use contraction theory to establish the global stability of a traveling-wave or synchronous oscillation, determined by the type of coupling. This opens the door to better design of coupling architectures to create the desired type of stable oscillations. We then use coupling that is both amplitude and phase dependent to create either globally stable synchronous or traveling-wave solutions. Using the CPG motor neuron network of a leech as an example, we show that while both traveling and synchronous oscillations can be achieved by several types of coupling, the transition between different types of behavior is dictated by a specific coupling architecture. In particular, it is only the “repulsive” but not the commonly used phase or rotational coupling that can explain the transition to high-frequency synchronous oscillations that have been observed in the heartbeat pattern generator of a leech. This shows that the overall dynamics of a CPG can be highly sensitive to the type of coupling used, even for coupling architectures that are widely believed to produce the same qualitative behavior.

  16. Control of traveling-wave oscillations and bifurcation behavior in central pattern generators.

    PubMed

    Landsman, Alexandra S; Slotine, Jean-Jacques

    2012-10-01

    Understanding synchronous and traveling-wave oscillations, particularly as they relate to transitions between different types of behavior, is a central problem in modeling biological systems. Here, we address this problem in the context of central pattern generators (CPGs). We use contraction theory to establish the global stability of a traveling-wave or synchronous oscillation, determined by the type of coupling. This opens the door to better design of coupling architectures to create the desired type of stable oscillations. We then use coupling that is both amplitude and phase dependent to create either globally stable synchronous or traveling-wave solutions. Using the CPG motor neuron network of a leech as an example, we show that while both traveling and synchronous oscillations can be achieved by several types of coupling, the transition between different types of behavior is dictated by a specific coupling architecture. In particular, it is only the "repulsive" but not the commonly used phase or rotational coupling that can explain the transition to high-frequency synchronous oscillations that have been observed in the heartbeat pattern generator of a leech. This shows that the overall dynamics of a CPG can be highly sensitive to the type of coupling used, even for coupling architectures that are widely believed to produce the same qualitative behavior.

  17. Minnesota Tribal Coalition - Final Report

    SciTech Connect

    Michael Triplett

    2006-12-19

    The project helped tribal leaders, staff and community members on the Grand Portage, Leech Lake, and White Earth Reservations better understand their community's energy usage, assess local resources that might be utilized to reduce energy consumption and begin to formulate appropriate development strategies. The principal guiding interest was to assess energy usage and the potential for wind resource development on each of the three reservations. Key tribal staff became familiar with wind energy technology and assessment methodologies that will be of continued use as each tribe moves forward with development projects. The findings were that wind resources are available at each reservation with varying degrees of potential for development. At White Earth moderate to excellent resources are present at White Earth village and along the U.S. 59 corridor sufficient to be tapped to serve several scattered tribal complexes. At Grand Portage a former community television repeater tower site provides a viable elevated location for a wind turbine to serve the tribal community settlement. At Leech Lake, while most constrained by tree cover, a site adjacent to a casino holds promise for the newer taller wind turbines now coming to market at ever-increasing taller rotor heights. The project developed considerable data of importance regarding the potential for wind development on and near each reservation.

  18. Blood meal analysis of tabanid fly after it biting the rare Sumatran rhinoceros

    PubMed Central

    Rovie-Ryan, Jeffrine Japning; Zainuddin, Zainal Zahari; Marni, Wahap; Ahmad, Abdul Hamid; Ambu, Laurentius N.; Payne, Junaidi

    2013-01-01

    Objective To demonstrate a noninvasive large mammalian genetic sampling method using blood meal obtained from a tabanid fly. Methods Blood meal was recovered from the abdomen of an engorged tabanid fly (Haematopota sp.) which was captured immediately after biting a Sumatran rhino in captivity. The blood was applied on to a Whatman FTA® blood card. Subsequent laboratory work was conducted to extract, amplify and sequence the DNA from the sample. Validation was done by sampling the hair follicles and blood samples from the rhinoceros and subjecting it to the same laboratory process. Results BLAST search and constructed phylogenetic trees confirmed the blood meal samples were indeed from the rhino. Conclusions This method could be used in the field application to noninvasively collect genetic samples. Collection of tabanids and other haematophagous arthropods (e.g. mosquitoes and ticks) and other blood-sucking parasites (e.g. leeches and worms) could also provide information on vector-borne diseases. PMID:23593586

  19. Aquatic macroinvertebrates associated with Schoenoplectus litter in a constructed wetland in California (USA)

    USGS Publications Warehouse

    Nelson, S.M.; Thullen, J.S.

    2008-01-01

    Culm processing characteristics were associated with differences in invertebrate density in a study of invertebrates and senesced culm packs in a constructed treatment wetland. Invertebrate abundance differed by location within the wetland and there were differences between the two study years that appeared to be related to water quality and condition of culm material. Open areas in the wetland appeared to be critical in providing dissolved oxygen (DO) and food (plankton) to the important invertebrate culm processor, Glyptotendipes. As culm packs aged, invertebrate assemblages became less diverse and eventually supported mostly tubificid worms and leeches. It appears from this study that wetland design is vital to processing of plant material and that designs that encourage production and maintenance of high DO's will encourage microbial and invertebrate processing of material.

  20. [Proteins influencing the blood coagulation].

    PubMed

    Alberio, Lorenzo

    2011-11-01

    This review describes some natural proteins, which can be employed, either as factor concentrates derived from human plasma or as recombinant drug, to modulate the coagulation system. I will address some biochemical characteristics and the physiological role of von Willebrand factor, the coagulation factors of the extrinsic and intrinsic pathways, and the physiological anticoagulant protein C. In addition, I will detail the pharmacological compounds, which are available for influencing or substituting the coagulation proteins: desmopressin (DDAVP), single coagulation factor concentrates, prothrombin complex concentrates, and protein C concentrate. In particular, I will address some treatment topics of general medical interest, such as the treatment of massive bleeding, the correction of the coagulopathy induced by vitamin K-antagonists in patients with cerebral haemorrhage, and of the coagulopathy of meningococcemia. Finally, I will describe some properties and practical clinical applications of the recombinant anticoagulans lepirudin and bivalirudin, which are derived from hirudin, the natural anticoagulant of the medical leech.

  1. Neuronal control of swimming behavior: comparison of vertebrate and invertebrate model systems.

    PubMed

    Mullins, Olivia J; Hackett, John T; Buchanan, James T; Friesen, W Otto

    2011-02-01

    Swimming movements in the leech and lamprey are highly analogous, and lack homology. Thus, similarities in mechanisms must arise from convergent evolution rather than from common ancestry. Despite over 40 years of parallel investigations into this annelid and primitive vertebrate, a close comparison of the approaches and results of this research is lacking. The present review evaluates the neural mechanisms underlying swimming in these two animals and describes the many similarities that provide intriguing examples of convergent evolution. Specifically, we discuss swim initiation, maintenance and termination, isolated nervous system preparations, neural-circuitry, central oscillators, intersegmental coupling, phase lags, cycle periods and sensory feedback. Comparative studies between species highlight mechanisms that optimize behavior and allow us a broader understanding of nervous system function.

  2. Biogeochemistry of Mangrove Soil Organic Matter: a Comparison Between Rhizophoraand AvicenniaSoils in South-eastern Brazil

    NASA Astrophysics Data System (ADS)

    Lacerda, L. D.; Ittekkot, V.; Patchineelam, S. R.

    1995-06-01

    Soil core samples from Rhizophora mangleL. and Avicennia schauerianaStapf & Leech forests from south-eastern Brazil were analysed for their total organic matter content and their sugars, amino acid and amino sugars composition. Organic carbon and nitrogen contents were higher in Avicenniathan in Rhizophorasoils. The contribution of sugars and amino acids to the total organic carbon pool was constant with depth in Rhizophorasoils whereas in Avicenniasoils it increased. Spectral distribution of sugars and amino acids showed a dominance of Ca-affine monomers, particularly acidic amino acids, and the sugar arabinose. Biogeochemical indicators derived from ratios of individual sugar and amino acid monomers confirm previous studies which showed that organic matter in both soils is mainly of mangrove origin. The results further suggest accumulation of organic matter in Rhizophorasoils and a continuing degradation of organic matter in Avicenniasoils. The latter may thus release more nutrients to adjacent ecosystems than Rhizophorasoils.

  3. Patch-clamp experiments under micro-gravity.

    PubMed

    Meissner, Klaus; Hanke, Wolfgang

    2002-07-01

    For human based space research it is of high importance to understand the influence of gravity on the properties of single ion channels in biological membranes, as these are involved in about all biological processes. The patch clamp technique is the best established method to investigate electrophysiological properties of single ion channels in detail. Consequently, a patch clamp set-up was designed for the drop tower in Bremen, Germany. Using this set-up among others, successfully leech neurons have been patched under micro-gravity, delivering data about ion channel behaviour, which were compared to results from bilayer experiments in the drop tower and to results from lab controls under 1 g and under higher gravity.

  4. Test of a life support system with Hirudo medicinalis in a sounding rocket.

    PubMed

    Lotz, R G; Baum, P; Bowman, G H; Klein, K D; von Lohr, R; Schrotter, L

    1972-01-01

    Two Nike-Tomahawk rockets each carrying two Biosondes were launched from Wallops Island, Virginia, the first on 10 December 1970 and the second on 16 December 1970. The primary objective of both flights was to test the Biosonde life support system under a near weightless environment and secondarily to subject the Hirudo medicinalis to the combined stresses of a rocket flight. The duration of the weightless environment was approximately 6.5 minutes. Data obtained during the flight by telemetry was used to ascertain the operation of the system and the movements of the leeches during flight. Based on the information obtained, it has been concluded that the operation of the Biosondes during the flight was similar to that observed in the laboratory. The experiment and equipment are described briefly and the flight results presented.

  5. Excitotoxic potential of the cyanotoxin β-methyl-amino-L-alanine (BMAA) in primary human neurons.

    PubMed

    Chiu, Alexander S; Gehringer, Michelle M; Braidy, Nady; Guillemin, Gilles J; Welch, Jeffrey H; Neilan, Brett A

    2012-11-01

    The toxicity of the cyanobacterial modified amino acid, BMAA, has been described in rat, mouse and leech neurons. Particular emphasis has been placed on the potential ability of BMAA to induce neuronal damage via excitotoxic mechanisms. Here we present data indicating that the effects observed on lower organisms are also evident in a human model. Our data indicates that BMAA induces increased intracellular Ca²⁺ influx, DNA damage, mitochondrial activity, lactate dehydrogenase (LDH) release and generation of reactive oxygen species (ROS). The amelioration of LDH release in the presence of the N-methyl-D-aspartate (NMDA) receptor antagonist MK801 indicates that the neurotoxic effects of BMAA are mediated via NMDA receptor activation. Additionally, we have shown that BMAA induces the expression of neuronal nitric oxide synthase (nNOS) and caspase-3 indicating that it can stimulate apoptosis in human neurons, presumably via activation of NMDA receptors.

  6. A new species and two new combinations in the genus Strotihypera Kononenko & Han, 2011 (Lepidoptera, Noctuidae, Noctuinae: Elaphriini). A postscript to the description of the genus Strotihypera.

    PubMed

    Han, H L; Kononenko, V S

    2015-10-30

    Elaphriini is a small tribe of the subfamily Noctuinae with predominantly New World distribution. Only three genera, Elaphria Hübner, 1818 with four species, Galgula Guenée, 1852 with one species (Fibiger & Hacker 2010) and Strotihypera Kononenko & Han, 2011 with one species are known from the Eurasia. The majority of species occurs in tropical and subtropical regions. The review of Eurasian Elaphriini with description of the new genus Strotihypera has recently been published by Kononenko & Han (2011). In the subsequent years in the result of intensive collecting in South West China we found a new species allied to Strotihypera flavipuncta (Leech, 1889) and two related species Strotihypera ochreipuncta (Wileman, 1914), comb. n. and "Hyperstrotia" macroplaga (Hampson, 1907), comb. n. The description of a new species and the review of two of its allies are presented here as a postscript to the description of the genus Strotihypera (Kononenko & Han 2011).

  7. Traditional healers in the Qazvin region of the Islamic Republic of Iran: a qualitative study.

    PubMed

    Asefzadeh, S; Sameefar, F

    2001-05-01

    We identified and categorized by method of therapy 15 traditional healers in the Qazvin region. Problem-solving and treatment procedures were observed and recorded by actual patients or by observers simulating a medical condition. The treatment practices of the 15 healers (8 men and 7 women) included herbal remedies (four), bone-setting (five), traditional methods for the treatment of sore throat (two), massage therapy using plant oils (one), cupping (two), and leech therapy (one). Despite an adequate number of physicians practising in the region, traditional healers continue to be consulted. We recommend that the efficacy of their treatments be further studied and that they be encouraged to contribute positively to the broader health objectives of Iranian society.

  8. Direct methods for dynamic monitoring of secretions from single cells by capillary electrophoresis and microscopy with laser-induced native fluorescence detection

    SciTech Connect

    Tong, Wei

    1997-10-08

    Microscale separation and detection methods for real-time monitoring of dynamic cellular processes (e.g., secretion) by capillary electrophoresis (CE) and microscopic imaging were developed. Ultraviolet laser-induced native fluorescence (LINF) provides simple, sensitive and direct detection of neurotransmitters and proteins without any derivatization. An on-column CE-LINF protocol for quantification of the release from single cell was demonstrated. Quantitative measurements of both the amount of insulin released from and the amount remaining in the cell (βTC3) were achieved simultaneously. Secretion of catecholamines (norepinephrine (NE) and epinephrine (E)) from individual bovine adrenal chromaffin cells was determined using the on-column CE-LINF. Direct visualization of the secretion process of individual bovine adrenal chromaffin cells was achieved by LINF imaging microscopy with high temporal and spatial resolution. The secretion of serotonin from individual leech Retzius neurons was directly characterized by LINF microscopy with high spatial resolution.

  9. The complete mitochondrial genome of Paracymoriza distinctalis (Lepidoptera: Crambidae).

    PubMed

    Ye, Fei; You, Ping

    2016-01-01

    The complete mitochondrial genome of Paracymoriza distinctalis (Leech, 1889) has been determined in this article. The mitochondrial genome of P. distinctalis was 15,354 bp in length, containing 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, 2 ribosomal RNA (rRNA) genes and an A + T-rich region. All PCGs start with ATN codon, except for COI, which begins with CGA. Eleven PCGs stop with typical stop codon TAA. But ND5 and COII use incomplete stop codon T. All the 22 tRNAs have the typical clover-leaf structure except for tRNA(Ser)(AGN) lacking the dihydrouridine (DHU) stem. There were several conserved motifs in the intergenic region between tRNA(Ser)(UCN) and ND1 and the A + T-rich region of P. distinctalis.

  10. A review of Luxiaria Walker and its allied genus Calletaera Warren (Lepidoptera, Geometridae, Ennominae) from China.

    PubMed

    Jiang, Nan; Xue, Dayong; Han, Hongxiang

    2014-08-21

    The genus Luxiaria Walker and its allied genus Calletaera Warren in China, including 16 species in all, are reviewed. Five new species are described: C. obvia sp. nov., C. acuticornuta sp. nov., C. rotundicornuta sp. nov., C. dentata sp. nov., C. trigonoprocessus sp. nov. The species L. acutaria (Snellen, 1877) and L. tephrosaria (Moore, 1868) are newly recorded for China. Two new combinations are established: C. obliquata (Moore, 1888) comb. nov. and C. consimilaria (Leech, 1897) comb. nov. Four new synonyms are established: Eutoea Walker, 1860 (= Bithiodes Warren, 1894 syn. nov.); Calletaera Warren, 1895 (=Bithiodes Warren, 1899 syn. nov.), based on the fixation of nominal type Acidalia inexactata Walker, 1861, for the genus name Bithiodes Warren, 1894; L. emphatica Prout, 1925 (= L. costinota Inoue, 1978 syn. nov.); C. subexpressa (Walker, 1861) (= C. digrammata Wehrli, 1925 syn. nov.). Diagnoses for all Chinese species are provided. Illustrations of external features and genitalia are presented. 

  11. Release of acetylcholine by chick embryo heart before innervation

    PubMed Central

    Coraboeuf, E.; Le Douarin, G.; Obrecht-Coutris, G.

    1970-01-01

    1. In chick embryo hearts, 3-day-old and not yet innervated, repetitive direct stimulation causes a transitory inhibition of the spontaneous rhythm. 2. The degree of post-stimulation inhibition depends on the frequency and duration of the artificial stimulation and on the concentration of K and Ca ions in the extracellular solution. 3. After treatment with atropine (10-5 g/ml.) post-stimulation inhibition is no longer observed. The spontaneous rhythm is accelerated by atropine. The findings therefore suggest that an ACh-like substance is released from the non-innervated embryonic heart during activity. 4. By use of the dorsal muscle of the leech for biological assay the liberation of an ACh-like substance from the non-innervated embryonic heart was confirmed. ImagesPlate 1 PMID:5498489

  12. Sample Limited Characterization of a Novel Disulfide-Rich Venom Peptide Toxin from Terebrid Marine Snail Terebra variegata

    PubMed Central

    Anand, Prachi; Grigoryan, Alexandre; Bhuiyan, Mohammed H.; Ueberheide, Beatrix; Russell, Victoria; Quinoñez, Jose; Moy, Patrick; Chait, Brian T.; Poget, Sébastien F.; Holford, Mandë

    2014-01-01

    Disulfide-rich peptide toxins found in the secretions of venomous organisms such as snakes, spiders, scorpions, leeches, and marine snails are highly efficient and effective tools for novel therapeutic drug development. Venom peptide toxins have been used extensively to characterize ion channels in the nervous system and platelet aggregation in haemostatic systems. A significant hurdle in characterizing disulfide-rich peptide toxins from venomous animals is obtaining significant quantities needed for sequence and structural analyses. Presented here is a strategy for the structural characterization of venom peptide toxins from sample limited (4 ng) specimens via direct mass spectrometry sequencing, chemical synthesis and NMR structure elucidation. Using this integrated approach, venom peptide Tv1 from Terebra variegata was discovered. Tv1 displays a unique fold not witnessed in prior snail neuropeptides. The novel structural features found for Tv1 suggest that the terebrid pool of peptide toxins may target different neuronal agents with varying specificities compared to previously characterized snail neuropeptides. PMID:24713808

  13. [Bizerine: new anticholinesterase drug with selective gastrointestinal action].

    PubMed

    Prozorovskiĭ, V B; Pavlova, L V; Suslova, I M; Sazonova, A V; Shchemeleva, N I

    2010-08-01

    Bizerine-oxalate of hexamethylene-bic-[N-methylcarbamic acid-3-(2-dimethylaminomethyl)pyridyl ether] exhibits the properties of acetylcholine esterase (AChE) inhibitor, being comparable in this respect in in vitro tests to aminostigmine. Bizerine is 2.5 and 6.7 times less active in these tests than proserine and distigmine, respectively, but it forms more stable complex with the enzyme. Bizerine is 10-80 times less toxic for laboratory mammals as compared to prozerine; it is 3-60 times more active on the isolated urinary bladder of rats, but it is 100-500 times less effective on the spinal muscle of leeches and skeletal muscles of mice and rats. Bizerine actively inhibits intestinal cholinesterase (ChE) of guinea pigs. In systematic use, it does not inhibit brain ChE of mice. Bizerine is a prolonged peripheral muscarinic potentiating inhibitor of ChE and activator of intestinal peristalsis.

  14. Bilingual children show an advantage in controlling verbal interference during spoken language comprehension*

    PubMed Central

    FILIPPI, ROBERTO; MORRIS, JOHN; RICHARDSON, FIONA M.; BRIGHT, PETER; THOMAS, MICHAEL S. C.; KARMILOFF-SMITH, ANNETTE; MARIAN, VIORICA

    2014-01-01

    Studies measuring inhibitory control in the visual modality have shown a bilingual advantage in both children and adults. However, there is a lack of developmental research on inhibitory control in the auditory modality. This study compared the comprehension of active and passive English sentences in 7–10 years old bilingual and monolingual children. The task was to identify the agent of a sentence in the presence of verbal interference. The target sentence was cued by the gender of the speaker. Children were instructed to focus on the sentence in the target voice and ignore the distractor sentence. Results indicate that bilinguals are more accurate than monolinguals in comprehending syntactically complex sentences in the presence of linguistic noise. This supports previous findings with adult participants (Filippi, Leech, Thomas, Green & Dick, 2012). We therefore conclude that the bilingual advantage in interference control begins early in life and is maintained throughout development. PMID:26146479

  15. Screening of parasitic and IHHNV infections in wild giant freshwater prawn Macrobrachium rosenbergii from Rejang River at Kuching, Sarawak.

    PubMed

    Kua, Beng Chu; Choong, F C; Hazreen Nita, M K; Muhd Faizul H, A H; Bhassu, S; Imelda, R R; Mohammed, M

    2011-04-01

    A preliminary survey of parasitic and infectious hypodermal and haematopoietic necrosis virus (IHHNV) infections in giant freshwater prawn from the Damak Sea of Rejang River, Kuching, Sarawak was conducted. Symptoms of black spots/patches on the rostrum, carapace, pleopods or telson were observed in most of the 107 samples collected. Parasitic examination revealed sessiline peritrichs such as (Zoothamnium sp.), nematode larvae, gregarine stage and cocoon of leech with prevalences of 1.2%, 1.2%, 5% and 17% respectively. Under histopathological examination, changes like accumulation of hemocytes around hepatopancreatic tubules due to vibriosis, basophilic intranuclear inclusions in the epithelium and E-cell of hepatopancreatic tubules as a result of HPV were seen through the section. No positive infection of IHHNV was detected in 78 samples. As such, the wild giant freshwater prawns in Damak Sea of Rejang River in Kuching are IHHNV-free though infections of parvo-like virus and bacteria were seen in histopathology.

  16. Ab-initio study of polypyrrole as a pervaporation membrane

    NASA Astrophysics Data System (ADS)

    Botelho, Andre; Lin, Xi

    2010-03-01

    The affinities between polypyrrole, water, ethanol and a sulfonate-carrying ion were calculated from first principles. All interactions were demonstrably hydrogen bonds between the oxygen from the sulfonate groups and the hydrogen in the hydroxyl (for water and ethanol) and amine groups (for polypyrrole). Each sulfonate group was shown to form three hydrogen bonds, with any of the three other types of molecules, allowing the ion complex to bind to multiple polypyrrole chains, water, and ethanol molecules simultaneously. The energies indicated a higher affinity between the ion and poypyrrole, second highest between water and the ion, and the lowest for ethanol and the ion. A high affinity of the ion to the polymer backbone is desirable to prevent leeching. The ion was found to have a higher affinity to water molecules than to ethanol, confirming the system's selectivity in separating water from ethanol.

  17. Feeding behavior and trophic relationship of earthworms and other predators in vermifiltration system for liquid-state sludge stabilization using fatty acid profiles.

    PubMed

    Xing, Meiyan; Zhao, Chunhui; Yang, Jian; Lv, Baoyi

    2014-10-01

    The sludge reduction capability (VSS reduction) of vermifilter (VF) was 14.7% higher than that of conventional biofilter (BF) due to the fact that there was a net loss of biomass and energy when the food web in VF is extended. Therefore, feeding behavior and trophic relationship of earthworms and other predators (leeches, lymnaeidaes and limaxes) in VF were investigated using fatty acid (FA) profiles for the first time. Compared with BF biofilm, microbial community structure of VF biofilm got optimized by earthworms that the percentage of protozoa increased from 14.2% to 20.4%. Furthermore, analysis of specific microbial FAs composition in each predator suggested different trophic level of predators resulted from their selective ingestion of different microorganisms, and earthworms were at the second high trophic level in VF food web. Overall findings indicated earthworms modified microbial community and extended the food web of VF and thus enhanced the sludge reduction.

  18. Application of real time systems to the analysis of neuronal dynamics

    NASA Astrophysics Data System (ADS)

    Cymbalyuk, Gennady; Shilnikov, Andrey

    2008-03-01

    Neurons exhibit various activity regimes and transitions in between. The central pattern generator controlling the leech's heartbeat contains identified pairs of mutually inhibitory neurons (Calabrese et al. 1995). We describe real time systems approaches to the analysis of their activity. The hybrid system consists of a living neuron and a model neuron (or an artificial silicon neuron) interacting in the real time. Dynamic clamp is used to implement artificial ionic currents and synapses in the system (Sharp et al. 1993). Our study determines the mechanisms underlying and regulating bursting activity, based on intrinsic membrane dynamics and network interactions. The complexity of endogenous dynamics originates from the diversity of ionic currents operating on different time scales. Hybrid system analysis and slow-fast dynamical systems analysis have been combined in our studies of bursting, its origin and transformations in heart interneurons both as single cells and in the mutually inhibitory configuration.

  19. Biomonitoring of river pollution by heavy metals in reserves on the basis of studies on metal accumulation in the body of aquatic invertebrates

    SciTech Connect

    Zhulidov, A.V.; Emets, V.M.; Shevtsov, A.S.

    1980-05-01

    In recent years particular importance has been attached to biological monitoring, with biosphere reserves moving into the forefront as background-monitoring stations. However, the biomonitoring of river pollution by heavy metals is poorly developed and is not carried out in reserves. The realization of this type of monitoring is prevented in no small degree by the inadequate extent to which the accumulation of heavy metals in the body of freshwater invertebrates has been studied; some data exist on individual species os bivalve and gastropod mollusks, leeches, crustaceans, mayflies, dragonflies dipterous insects, and caddis flies. A number of groups of large freshwater invertebrates important in the biocenological sense, especially bugs and beetles, have not been investigated at all in respect to heavy-metal accumulation. The present communication demonstrates the possibility of utilizing aquatic gastropod mollusks and insects (bugs and beetles) to characterize river pollution by heavy metals in the reserves.

  20. Partial salvage of avulsed tissue after dog bite

    PubMed Central

    Øregaard, JS; Lang, CL; Venzo, A

    2016-01-01

    Injuries to the nose can be severe from both a functional and cosmetic perspective. After suffering a dog bite to the central part of the face, an 18-year old woman underwent replantation of the avulsed tissue with the help of microsurgical arterial anastomosis. A venous anastomosis was impossible and venous congestion was treated with leech therapy. Subsequent skin necrosis occurred after a few days and the replantation was revised, revealing healthy tissue immediately below. The defect was covered with a full-thickness skin graft. At follow-up review eight months later, the functional and cosmetic result was satisfactory. To our knowledge, this is one of few cases where an injury of this severity healed with a cosmetically acceptable result. PMID:26673050

  1. Hyperbaric oxygen (HBO2) treatment for a failing facial flap.

    PubMed

    McCrary, Brian F

    2007-01-01

    Hyperbaric oxygen (HBO2) is an approved treatment for 13 pathological entities. One of these indications--a failing facial flap--is presented in this case report of a traumatic wound to the face and right axilla after an unprovoked pit bull attack on a 4 year old girl. Surgical repair was started acutely but the facial flap became congested and ischaemic, indicating deterioration of the blood supply. HBO2 treatments were initiated twice a day, resulting in remarkably decreased swelling and discomfort after the first treatment. Leeching was also used to assist with reduction of venous congestion in the flap. The patient was discharged 5 days later with a well perfused, mostly intact, incision with minimal tenderness. Surgical repair was required for a small area of wound dehiscence. Photographs documenting the patient's progress with HBO2 are presented. A discussion of the mechanisms of action of HBO2 and its beneficial effects is provided in this case.

  2. Nanocoax neurointerface array recordings of Hirudo medicinalis neurons

    NASA Astrophysics Data System (ADS)

    Naughton, Jeffrey R.; Rizal, Binod; Aasen, Margaret H.; Burns, Michael J.; Chiles, Thomas C.; Naughton, Michael J.

    2014-03-01

    We report results for a nanocoax-based neuroelectronic array. The device was used in real time to noninvasively couple to a ganglion sac located along the main nerve cord of the leech Hirudo medicinalis. This allowed for extracellular recording of synaptic activity in the form of spontaneous synapse firing in pre- and post-synaptic somata. In addition, we show the ability to actuate localized stimulation (Faradaic regime) which, in some circumstances, appears to facilitate electroporation, which itself enables intracellular measurements. In conjunction with this latter recording with one subarray, we measured changes in the local field potential (extracellular) with another array at a second site, allowing us to calculate the action potential propagation or conduction speed. This work is supported by the Boston College Institute on Aging.

  3. Pop-Cola Acids and Tooth Erosion: An In Vitro, In Vivo, Electron-Microscopic, and Clinical Report

    PubMed Central

    Borjian, Amirfirooz; Ferrari, Claudia C. F.; Anouf, Antoni; Touyz, Louis Z. G.

    2010-01-01

    Introduction. Manufactured Colas are consumed universally as soft drinks. Evidence about the acid contents of Cola-beverages and its effects on teeth is rare. Aim. To assess (i) cola acidity and buffering capacity in vitro, (ii) tooth erosion after swishing with colas in vivo (iii) scanning electron microscopic effects on teeth of colas, and tooth-brush abrasion, and (iv) report a clinical case of erosion from cola consumption. Materials and Methods. (i) We measured six commercially available pop “Cola beverages”, pH, and buffering capacities using a pH-Mettler Automatic Titrator, with weak solution of Sodium Hydroxide (ii) two cohorts, one with teeth, the second without teeth rinsed with aliquots of Cola for 60 seconds. Swished cola samples tested for calcium and phosphorus contents using standardized chemical analytical methods (iii) enamel, dentine, and the enamel-cemental junction from unerupted extracted wisdom teeth were examined with a scanning electron microscope after exposure to colas, and tested for tooth-brush abrasion; (iv) a clinical case of pop cola erosion presentation, are all described. Results. Comparisons among pop colas tested in vitro reveal high acidity with very low pH. Buffering capacities in millilitres of 0.5 M NaOH needed to increase one pH unit, to pH 5.5 and pH 7 are reported. Rinsing in vivo with pop cola causes leeching of calcium from teeth; SEM shows dental erosion, and pop-cola consumption induces advanced dental erosion and facilitates abrasion. Conclusions. (i) Pop-Cola acid activity is below the critical pH 5.5 for tooth dissolution, with high buffering capacities countering neutralization effects of saliva; (ii) calcium is leeched out of teeth after rinsing with pop colas; (iii) SEM evidence explains why chronic exposure to acid pop colas causes dental frangibles; (iv) a clinical case of pop-cola erosion confirms this. PMID:21151663

  4. Neuroglial ATP release through innexin channels controls microglial cell movement to a nerve injury

    PubMed Central

    Lipitz, Jeffrey B.; Dahl, Gerhard

    2010-01-01

    Microglia, the immune cells of the central nervous system, are attracted to sites of injury. The injury releases adenosine triphosphate (ATP) into the extracellular space, activating the microglia, but the full mechanism of release is not known. In glial cells, a family of physiologically regulated unpaired gap junction channels called innexons (invertebrates) or pannexons (vertebrates) located in the cell membrane is permeable to ATP. Innexons, but not pannexons, also pair to make gap junctions. Glial calcium waves, triggered by injury or mechanical stimulation, open pannexon/innexon channels and cause the release of ATP. It has been hypothesized that a glial calcium wave that triggers the release of ATP causes rapid microglial migration to distant lesions. In the present study in the leech, in which a single giant glial cell ensheathes each connective, hydrolysis of ATP with 10 U/ml apyrase or block of innexons with 10 µM carbenoxolone (CBX), which decreased injury-induced ATP release, reduced both movement of microglia and their accumulation at lesions. Directed movement and accumulation were restored in CBX by adding ATP, consistent with separate actions of ATP and nitric oxide, which is required for directed movement but does not activate glia. Injection of glia with innexin2 (Hminx2) RNAi inhibited release of carboxyfluorescein dye and microglial migration, whereas injection of innexin1 (Hminx1) RNAi did not when measured 2 days after injection, indicating that glial cells’ ATP release through innexons was required for microglial migration after nerve injury. Focal stimulation either mechanically or with ATP generated a calcium wave in the glial cell; injury caused a large, persistent intracellular calcium response. Neither the calcium wave nor the persistent response required ATP or its release. Thus, in the leech, innexin membrane channels releasing ATP from glia are required for migration and accumulation of microglia after nerve injury. PMID:20876360

  5. ATP and NO Dually Control Migration of Microglia to Nerve Lesions

    PubMed Central

    Duan, Yuanli; Sahley, Christie L.; Muller, Kenneth J.

    2009-01-01

    Microglia migrate rapidly to lesions in the central nervous system (CNS), presumably in response to chemoattractants including ATP released directly or indirectly by the injury. Previous work on the leech has shown that nitric oxide (NO), generated at the lesion, is both a stop signal for microglia at the lesion and crucial for their directed migration from hundreds of micrometers away within the nerve cord, perhaps mediated by a soluble guanylate cyclase (sGC). In the present study, application of 100 μM ATP caused maximal movement of microglia in leech nerve cords. The nucleotides ADP, UTP, and the non-hydrolyzable ATP analog AMP-PNP (adenyl-5′-yl imidodiphosphate) also caused movement, whereas AMP, cAMP and adenosine were without effect. Both movement in ATP and migration after injury were slowed by 50 μM reactive blue 2 (RB2), an antagonist of purinergic receptors, without influencing the direction of movement. This contrasted with the effect of the NO scavenger cPTIO (2-(4-carboxyphenyl)-4,4,5,5-teramethylimidazoline-oxyl-3-oxide), which misdirected movement when applied at 1 mM. The cPTIO reduced cGMP immunoreactivity without changing immunoreactivity of eNOS (endothelial nitric oxide synthase), which accompanies increased NOS activity after nerve cord injury, consistent with involvement of sGC. Moreover, the sGC-specific inhibitor LY83583 applied at 50 μM had a similar effect, in agreement with previous results with methylene blue. Taken together, the experiments support the hypothesis that ATP released directly or indirectly by injury activates microglia to move, while NO which activates sGC directs migration of microglia to CNS lesions. PMID:19025930

  6. Variation in motor output and motor performance in a centrally generated motor pattern.

    PubMed

    Wenning, Angela; Norris, Brian J; Doloc-Mihu, Anca; Calabrese, Ronald L

    2014-07-01

    Central pattern generators (CPGs) produce motor patterns that ultimately drive motor outputs. We studied how functional motor performance is achieved, specifically, whether the variation seen in motor patterns is reflected in motor performance and whether fictive motor patterns differ from those in vivo. We used the leech heartbeat system in which a bilaterally symmetrical CPG coordinates segmental heart motor neurons and two segmented heart tubes into two mutually exclusive coordination modes: rear-to-front peristaltic on one side and nearly synchronous on the other, with regular side-to-side switches. We assessed individual variability of the motor pattern and the beat pattern in vivo. To quantify the beat pattern we imaged intact adults. To quantify the phase relations between motor neurons and heart constrictions we recorded extracellularly from two heart motor neurons and movement from the corresponding heart segments in minimally dissected leeches. Variation in the motor pattern was reflected in motor performance only in the peristaltic mode, where larger intersegmental phase differences in the motor neurons resulted in larger phase differences between heart constrictions. Fictive motor patterns differed from those in vivo only in the synchronous mode, where intersegmental phase differences in vivo had a larger front-to-rear bias and were more constrained. Additionally, load-influenced constriction timing might explain the amplification of the phase differences between heart segments in the peristaltic mode and the higher variability in motor output due to body shape assumed in this soft-bodied animal. The motor pattern determines the beat pattern, peristaltic or synchronous, but heart mechanics influence the phase relations achieved.

  7. Long-term biological investigations in space.

    PubMed

    Lotz, R G; Fuchs, H; Bertsche, U

    1975-01-01

    Missions in space within the next two decades will be of longer duration than those carried out up to the present time, and the effects of such long-term flights on biological organisms are unknown. Results of biological experiments that have been performed to date cannot be extrapolated to results in future flights because of the unknown influence of adaptation over a long period of time. Prior experiments with Axolotl, fishes, and vertebrates by our research team (in part with sounding rockets) showed that these specimens did not appear to be suitable for long-term missions on which minimization of expense, technique, and energy is required. Subsequent investigations have shown the suitability of the leech (Hirudo medicinalis), which consumes blood of mammals up to ten times its own weight (1 g) and can live more than 2 years without further food supply. Emphasis in the experiments with Hirudo medicinalis is placed on metabolic rhythm and motility. Resorption and diffusion in tissue, development, and growth under long-term effects of cosmic proton radiation and zero-gravity are other focal points. The constancy of cellular life in the mature animals is a point in favor of these specimens. We have also taken into account the synergistic effects of the space environment on the problems just mentioned. The life-support system constructed for the leech has been tested successfully in four sounding rocket flights and, on that basis, has been prepared for a long-term mission. Long-term investigations out of the terrestrial biosphere will provide us with information concerning the degree of adaptation of certain physiological and biochemical functions and as to what extent biological readjustment or repair processes can occur under the specific stress conditions of space flight.

  8. Incorporating Climate Change Predictions into Watershed Restoration and Protection Strategies (WRAPS) in the Upper Mississippi River Basin

    NASA Astrophysics Data System (ADS)

    Burke, M. P.; Foreman, C. S.

    2014-12-01

    Development of the Watershed Restoration and Protection Strategies (WRAPS) for the Pine and Leech Lake River Watersheds is underway in Minnesota. Project partners participating in this effort include the Minnesota Pollution Control Agency (MPCA), Crow Wing Soil and Water Conservation District (SWCD), Cass County, and other local partners. These watersheds are located in the Northern Lakes and Forest ecoregion of Minnesota and drain to the Upper Mississippi River. To support the Pine and Leech Lake River WRAPS, watershed-scale hydrologic and water-quality models were developed with Hydrological Simulation Program-FORTRAN (HSPF). The HSPF model applications simulate hydrology (discharge, stage), as well as a number of water quality constituents (sediment, temperature, organic and inorganic nitrogen, total ammonia, organic and inorganic phosphorus, dissolved oxygen and biochemical oxygen demand, and algae) continuously for the period 1995-2009 and provide predictions at points of interest within the watersheds, such as observation gages, management boundaries, compliance points, and impaired water body endpoints. The model applications were used to evaluate phosphorus loads to surface waters under resource management scenarios, which were based on water quality threats that were identified at stakeholder meetings. Simulations of land use changes including conversion of forests to agriculture, shoreline development, and full build-out of cities show a watershed-wide phosphorus increases of up to 80%. The retention of 1.1 inches of runoff from impervious surfaces was not enough to mitigate the projected phosphorus load increases. Changes in precipitation projected by climate change models led to a 20% increase in annual watershed phosphorus loads. The scenario results will inform the implementation strategies selected for the WRAPS.

  9. Caulerpenyne, a toxin from the seaweed Caulerpa taxifolia, depresses afterhyperpolarization in invertebrate neurons.

    PubMed

    Mozzachiodi, R; Scuri, R; Roberto, M; Brunelli, M

    2001-01-01

    The massive invasion of the Mediterranean Sea by the tropical seaweed Caulerpa taxifolia (Vahl) C. Agardh has stimulated several investigations in order to test the environmental risk from an ecotoxicological point of view. The studies carried out on various experimental models have shown that caulerpenyne, the major metabolite synthesized by the seaweed, affects several cellular and molecular targets. In addition, neurological disorders have been reported in patients who accidentally ate C. taxifolia, but no evidence about the potential effects of the seaweed and of its metabolites on nerve cells were up to now available. Herein we describe that caulerpenyne modifies the electrical properties of touch mechanosensory cells of the leech Hirudo medicinalis. The physiological firing of these cells causes an afterhyperpolarization that is mainly due to the activity of the Na+/K+-ATPase and to a lesser extent to a calcium-dependent potassium current. Caulerpenyne depressed this afterhyperpolarization; the effect was dose-dependent and partially reversible. Experiments have been carried out in order to understand the mechanism through which caulerpenyne reduced the afterhyperpolarization. The action of the biotoxin has been tested in the presence of pharmacological blockers of calcium-dependent potassium channels such as cadmium and apamin. In these experimental conditions, caulerpenyne still reduced the residual afterhyperpolarization, suggesting a direct effect of the toxin on the Na+/K+-ATPase. In order to test this hypothesis, we have performed experiments where the Na+/K+-ATPase was activated by the intracellular injection of sodium and where also its basal activity was modified as well. From the data collected we suggest that caulerpenyne inhibits both the basal and the sodium-induced activity of the Na+/K+-ATPase in leech touch neurons.

  10. Physical methods for generating and decoding neural activity in Hirudo verbana

    NASA Astrophysics Data System (ADS)

    Migliori, Benjamin John

    The interface between living nervous systems and hardware is an excellent proving ground for precision experimental methods and information classification systems. Nervous systems are complex (104 -- 10 15(!) connections), fragile, and highly active in intricate, constantly evolving patterns. However, despite the conveniently electrical nature of neural transmission, the interface between nervous systems and hardware poses significant experimental difficulties. As the desire for direct interfaces with neural signals continues to expand, the need for methods of generating and measuring neural activity with high spatiotemporal precision has become increasingly critical. In this thesis, I describe advances I have made in the ability to modify, generate, measure, and understand neural signals both in- and ex-vivo. I focus on methods developed for transmitting and extracting signals in the intact nervous system of Hirudo verbana (the medicinal leech), an animal with a minimally complex nervous system (10000 neurons distributed in packets along a nerve cord) that exhibits a diverse array of behaviors. To introduce artificial activity patterns, I developed a photothermal activation system in which a highly focused laser is used to irradiate carbon microparticles in contact with target neurons. The resulting local temperature increase generates an electrical current that forces the target neuron to fire neural signals, thereby providing a unique neural input mechanism. These neural signals can potentially be used to alter behavioral choice or generate specific behavioral output, and can be used endogenously in many animal models. I also describe new tools developed to expand the application of this method. In complement to this input system, I describe a new method of analyzing neural output signals involved in long-range coordination of behaviors. Leech behavioral signals are propagated between neural packets as electrical pulses in the nerve connective, a bundle of

  11. Mechanisms underlying rhythmic locomotion: interactions between activation, tension and body curvature waves.

    PubMed

    Chen, Jun; Friesen, W Otto; Iwasaki, Tetsuya

    2012-01-15

    Undulatory animal locomotion arises from three closely related propagating waves that sweep rostrocaudally along the body: activation of segmental muscles by motoneurons (MNs), strain of the body wall, and muscle tension induced by activation and strain. Neuromechanical models that predict the relative propagation speeds of neural/muscle activation, muscle tension and body curvature can reveal crucial underlying control features of the central nervous system and the power-generating mechanisms of the muscle. We provide an analytical explanation of the relative speeds of these three waves based on a model of neuromuscular activation and a model of the body-fluid interactions for leech anguilliform-like swimming. First, we deduced the motoneuron spike frequencies that activate the muscle and the resulting muscle tension during swimming in intact leeches from muscle bending moments. Muscle bending moments were derived from our video-recorded kinematic motion data by our body-fluid interaction model. The phase relationships of neural activation and muscle tension in the strain cycle were then calculated. Our study predicts that the MN activation and body curvature waves have roughly the same speed (the ratio of curvature to MN activation speed ≈0.84), whereas the tension wave travels about twice as fast. The high speed of the tension wave resulting from slow MN activation is explained by the multiplicative effects of MN activation and muscle strain on tension development. That is, the product of two slower waves (activation and strain) with appropriate amplitude, bias and phase can generate a tension wave with twice the propagation speed of the factors. Our study predicts that (1) the bending moment required for swimming is achieved by minimal MN spike frequency, rather than by minimal muscle tension; (2) MN activity is greater in the mid-body than in the head and tail regions; (3) inhibitory MNs not only accelerate the muscle relaxation but also reduce the intrinsic

  12. Acute toxicity and hazard assessment of Rodeo®, X-77 Spreader®, and Chem-Trol® to aquatic invertebrates

    USGS Publications Warehouse

    Henry, C. J.; Higgins, K. F.; Buhl, K.J.

    1994-01-01

    The herbicide Rodeo® provides waterfowl managers with an effective chemical tool for creating open water habitats in wetlands if its use does not adversely affect native invertebrate communities. The survival of caged Chironomus spp. (midge), Hyalella azteca (amphipod),Stagnicola elodes (pond snail), and Nephelopsis obscura (leech) was assessed in prairie pothole wetlands treated by air with a tank mixture of Rodeo®, the surfactant X-77 Spreader®, and the drift retardant Chem-Trol® at a rate recommended for controlling cattails. Laboratory studies were then conducted to determine the acute toxicities of Rodeo®, X-77 Spreader®, and Chem-Trol®, individually and in simulated tank mixtures, to the same invertebrates and to Daphnia magna in reconstituted water representative of these wetlands. There was no difference in the survival of caged invertebrates between treated and reference wetlands after 21 days. Based on nominal concentrations of the formulations, X-77 Spreader® (LC50s=2.0–14.1 mg/L) was about 83–136 times more toxic than Rodeo® (LC50s=218–1216 mg/L) to aquatic invertebrates. Chem-Trol® killed ≤10% of the animals at 10,000 mg/L and ≤50% of the animals at 28,000 mg/L. Daphnia magna were more sensitive than the other species to X-77 Spreader®, Rodeo®, and the simulated Rodeo® tank mixture (RTM). The joint toxic action of the RTM was additive for amphipods and midges, greater than additive for leeches, and was less than additive for daphnids. X-77 Spreader® was the major toxic component in the RTM. Binary mixtures of X-77 Spreader®, Rodeo®, and Chem-Trol® at tank mixture and equitoxic ratios also showed additive toxicity to amphipods. The use of Rodeo® (applied as a tank mixture with X-77 Spreader® and Chem-Trol®) as a management tool in wetlands does not pose an acute hazard to native aquatic invertebrates because the concentrations of Rodeo®, X-77 Spreader®, and Chem-Trol® found to be acutely toxic to these invertebrates were

  13. Disintegrins from Hematophagous Sources

    PubMed Central

    Assumpcao, Teresa C. F.; Ribeiro, José M. C.; Francischetti, Ivo M. B.

    2012-01-01

    Bloodsucking arthropods are a rich source of salivary molecules (sialogenins) which inhibit platelet aggregation, neutrophil function and angiogenesis. Here we review the literature on salivary disintegrins and their targets. Disintegrins were first discovered in snake venoms, and were instrumental in our understanding of integrin function and also for the development of anti-thrombotic drugs. In hematophagous animals, most disintegrins described so far have been discovered in the salivary gland of ticks and leeches. A limited number have also been found in hookworms and horseflies, and none identified in mosquitoes or sand flies. The vast majority of salivary disintegrins reported display a RGD motif and were described as platelet aggregation inhibitors, and few others as negative modulator of neutrophil or endothelial cell functions. This notably low number of reported disintegrins is certainly an underestimation of the actual complexity of this family of proteins in hematophagous secretions. Therefore an algorithm was created in order to identify the tripeptide motifs RGD, KGD, VGD, MLD, KTS, RTS, WGD, or RED (flanked by cysteines) in sialogenins deposited in GenBank database. The search included sequences from various blood-sucking animals such as ticks (e.g., Ixodes sp., Argas sp., Rhipicephalus sp., Amblyommasp.), tabanids (e.g., Tabanus sp.), bugs (e.g., Triatoma sp., Rhodnius prolixus), mosquitoes (e.g., Anopheles sp., Aedes sp., Culex sp.), sand flies (e.g., Lutzomyia sp., Phlebotomus sp.), leeches (e.g., Macrobdella sp., Placobdella sp.) and worms (e.g., Ancylostoma sp.). This approach allowed the identification of a remarkably high number of novel putative sialogenins with tripeptide motifs typical of disintegrins (>450 sequences) whose biological activity remains to be verified. This database is accessible online as a hyperlinked worksheet and displays biochemical, taxonomic, and gene ontology aspects for each putative disintegrin. It is also freely

  14. Flexibility of the Thrombin-activatable Fibrinolysis Inhibitor Pro-domain Enables Productive Binding of Protein Substrates*

    PubMed Central

    Valnickova, Zuzana; Sanglas, Laura; Arolas, Joan L.; Petersen, Steen V.; Schar, Christine; Otzen, Daniel; Aviles, Francesc X.; Gomis-Rüth, F. Xavier; Enghild, Jan J.

    2010-01-01

    We have previously reported that thrombin-activatable fibrinolysis inhibitor (TAFI) exhibits intrinsic proteolytic activity toward large peptides. The structural basis for this observation was clarified by the crystal structures of human and bovine TAFI. These structures evinced a significant rotation of the pro-domain away from the catalytic moiety when compared with other pro-carboxypeptidases, thus enabling access of large peptide substrates to the active site cleft. Here, we further investigated the flexible nature of the pro-domain and demonstrated that TAFI forms productive complexes with protein carboxypeptidase inhibitors from potato, leech, and tick (PCI, LCI, and TCI, respectively). We determined the crystal structure of the bovine TAFI-TCI complex, revealing that the pro-domain was completely displaced from the position observed in the TAFI structure. It protruded into the bulk solvent and was disordered, whereas TCI occupied the position previously held by the pro-domain. The authentic nature of the presently studied TAFI-inhibitor complexes was supported by the trimming of the C-terminal residues from the three inhibitors upon complex formation. This finding suggests that the inhibitors interact with the active site of TAFI in a substrate-like manner. Taken together, these data show for the first time that TAFI is able to form a bona fide complex with protein carboxypeptidase inhibitors. This underlines the unusually flexible nature of the pro-domain and implies a possible mechanism for regulation of TAFI intrinsic proteolytic activity in vivo. PMID:20880845

  15. Summation of excitatory postsynaptic potentials in electrically-coupled neurones.

    PubMed

    Vazquez, Y; Mendez, B; Trueta, C; De-Miguel, F F

    2009-09-29

    Dendritic electrical coupling increases the number of effective synaptic inputs onto neurones by allowing the direct spread of synaptic potentials from one neurone to another. Here we studied the summation of excitatory postsynaptic potentials (EPSPs) produced locally and arriving from the coupled neurone (transjunctional) in pairs of electrically-coupled Retzius neurones of the leech. We combined paired recordings of EPSPs, the production of artificial excitatory postsynaptic potentials (APSPs) in neurone pairs with different coupling coefficients and simulations of EPSPs produced in the coupled dendrites. Summation of the EPSPs produced in the dendrites was always linear, suggesting that synchronous EPSPs are produced at two or more different pairs of coupled dendrites and not in both sides of any one gap junction. The different spatio-temporal relationships explored between pairs of EPSPs or APSPs produced three main effects. (1) Synchronous pairs of EPSPs or APSPs exhibited an elongation of their decay phase compared to single EPSPs. (2) Asymmetries in the amplitudes between the pair of EPSPs added a "hump" to the smallest EPSP. (3) Modelling the inputs near the electrical synapse or anticipating the production of the transjunctional APSP increased the amplitude of the compound EPSP. The magnitude of all these changes depended on the coupling coefficient of the neurones. We also show that the hump improves the passive conduction of EPSPs by adding low frequency components. The diverse effects of summation of local and alien EPSPs shown here endow electrically-coupled neurones with a wider repertoire of adjustable integrative possibilities.

  16. Bioinspired Non-iridescent Structural Color from Polymer Blend Thin Films

    NASA Astrophysics Data System (ADS)

    Nallapaneni, Asritha; Shawkey, Matthew; Karim, Alamgir

    Colors exhibited in biological species are either due to natural pigments, sub-micron structural variation or both. Structural colors thus exhibited can be iridescent (ID) or non-iridescent (NID) in nature. NID colors originate due to interference and coherent scattering of light with quasi-ordered micro- and nano- structures. Specifically, in Eastern Bluebird (Sialia sialis) these nanostructures develop as a result of phase separation of β-keratin from cytoplasm present in cells. We replicate these structures via spinodal blend phase separation of PS-PMMA thin films. Colors of films vary from ultraviolet to blue. Scattering of UV-visible light from selectively leeched phase separated blends are studied in terms of varying domain spacing (200nm to 2 μm) of film. We control these parameters by tuning annealing time and temperature. Angle-resolved spectroscopy studies suggest that the films are weakly iridescent and scattering from phase-separated films is more diffused when compared to well-mixed films. This study offers solutions to several color-based application in paints and coatings industry.

  17. Interaction of hirudin with thrombin: Identification of a minimal binding domain of hirudin that inhibits clotting activity

    SciTech Connect

    Mao, S.J.T.; Yates, M.T.; Owen, T.J.; Krstenansky, J.L. )

    1988-10-18

    Hirudin, isolated from the European leech Hirudo medicinalis, is a potent inhibitor of thrombin, forming an almost irreversible thrombin-hirudin complex. Previously, the authors have shown that the carboxyl terminus of hirudin (residues 45-65) inhibits clotting activity and without binding to the catalytic site of thrombin. In the present study, a series of peptides corresponding to this carboxyl-terminal region of hirudin have been synthesized, and their anticoagulant activity and binding properties to thrombin were examined. Binding was assessed by their ability to displace {sup 125}I-hirudin 45-65 from Sepharose-immobilized thrombin and by isolation of peptide-thrombin complexes. They show that the carboxyl-terminal 10 amino acid residues 56-65 (Phe-Glu-Glu-Ile-Pro-Glu-Glu-Tyr-Leu-Gln) are minimally required for binding to thrombin and inhibition of clotting. Phe-56 was critical for maintaining anticoagulant activity as demonstrated by the loss of activity when Phe-56 was substituted with D-Phe, Glu, or Leu. In addition, they found that the binding of the carboxyl-terminal peptide of hirudin with thrombin was associated with a significant conformational change of thrombin as judged by circular dichroism. This conformational change might be responsible for the loss of clotting activity of thrombin.

  18. Common mechanics of mode switching in locomotion of limbless and legged animals

    PubMed Central

    Kuroda, Shigeru; Kunita, Itsuki; Tanaka, Yoshimi; Ishiguro, Akio; Kobayashi, Ryo; Nakagaki, Toshiyuki

    2014-01-01

    Crawling using muscular waves is observed in many species, including planaria, leeches, nemertea, aplysia, snails, chitons, earthworms and maggots. Contraction or extension waves propagate along the antero-posterior axis of the body as the crawler pushes the ground substratum backward. However, the observation that locomotory waves can be directed forward or backward has attracted much attention over the past hundred years. Legged organisms such as centipedes and millipedes exhibit parallel phenomena; leg tips form density waves that propagate backward or forward. Mechanical considerations reveal that leg-density waves play a similar role to locomotory waves in limbless species, and that locomotory waves are used by a mechanism common to both legged and limbless species to achieve crawling. Here, we report that both mode switching of the wave direction and friction control were achieved when backward motion was induced in the laboratory. We show that the many variations of switching in different animals can essentially be classified in two types according to mechanical considerations. We propose that during their evolution, limbless crawlers first moved in a manner similar to walking before legs were obtained. Therefore, legged crawlers might have learned the mechanical mode of movement involved in walking long before obtaining legs. PMID:24718452

  19. Marine-derived nitrogen and carbon in freshwater-riparian food webs of the Copper River Delta, southcentral Alaska.

    PubMed

    Hicks, Brendan J; Wipfli, Mark S; Lang, Dirk W; Lang, Maria E

    2005-08-01

    After rearing to adulthood at sea, coho salmon (Oncorhynchus kisutch) return to freshwater to spawn once and then die on or near their spawning grounds. We tested the hypothesis that spawning coho salmon return marine N and C to beaver (Castor canadensis) ponds of the Copper River Delta (CRD), Cordova, southcentral Alaska, thereby enhancing productivity of the aquatic food webs that support juvenile coho salmon. We sampled three types of pond treatment: (1) natural enrichment by spawning salmon, (2) artificial enrichment via addition of salmon carcasses and eggs, and (3) ponds with no salmon enrichment. All ponds supported juvenile coho salmon. Seasonal samples of stable isotopes revealed that juvenile coho salmon, threespine sticklebacks (Gasterosteus aculeatus), caddisfly larvae, leeches, and chironomid midge larvae were enriched with marine N and C. The aquatic vascular plants bur reed (Sparganium hyperboreum), pondweed (Potamogeton gramineus), and mare's tail (Hippuris vulgaris) were enriched with marine N only. Riparian vegetation (Sitka alder Alnus viridis ssp. sinuata and willow Salix spp.) did not show enrichment. Artificial additions of adult carcasses and eggs of coho salmon increased the delta15N and delta13C values of juvenile coho salmon. In this dynamic and hydrologically complex coastal environment, spawning coho salmon contributed marine N and C comprising 10-50% of the dietary needs of juvenile coho salmon through direct consumption of eggs and carcass material. Invertebrates that have assimilated marine N and C yield a further indirect contribution. This perennial subsidy maintains the productivity of the ecosystem of the coho salmon on the CRD.

  20. Acetyl-l-carnitine prevents serotonin-induced behavioural sensitization and dishabituation in Hirudo medicinalis.

    PubMed

    Traina, Giovanna; Ristori, Chiara; Brunelli, Marcello; Scuri, Rossana

    2013-09-15

    Several studies suggest that acetyl-l-carnitine (ALC) might influence learning processes. Along this line of investigation, we have previously shown that ALC impaired sensitization and dishabituation induced by nociceptive stimulation of the dorsal skin of the leech Hirudo medicinalis, in the behavioural paradigm of the swim induction (SI). In previous works we showed that 5HT was involved in both sensitization and dishabituation of SI acting through the second messenger cAMP. In this work, we have reported that for given doses and temporal ranges ALC was able to block sensitization and to impair dishabituation mimicked by the injection of 5-HT or 8Br-cAMP, a membrane permeable analogue of cAMP. Our results show that a single treatment with 2mM ALC was the most effective concentration to block the onset of sensitization induced by 5-HT injection and its major effects occurred 11 days after ALC treatment. 2mM ALC also blocked sensitization induced by 8Br-cAMP injection, whereas, ALC did not completely abolish dishabituation induced by 5-HT or 8Br-cAMP injection at the tested concentrations and at every time point.

  1. Aerodynamics of Unsteady Sailing Kinetics

    NASA Astrophysics Data System (ADS)

    Keil, Colin; Schutt, Riley; Borshoff, Jennifer; Alley, Philip; de Zegher, Maximilien; Williamson, Chk

    2015-11-01

    In small sailboats, the bodyweight of the sailor is proportionately large enough to induce significant unsteady motion of the boat and sail. Sailors use a variety of kinetic techniques to create sail dynamics which can provide an increment in thrust, thereby increasing the boatspeed. In this study, we experimentally investigate the unsteady aerodynamics associated with two techniques, ``upwind leech flicking'' and ``downwind S-turns''. We explore the dynamics of an Olympic class Laser sailboat equipped with a GPS, IMU, wind sensor, and camera array, sailed expertly by a member of the US Olympic team. The velocity heading of a sailing boat is oriented at an apparent wind angle to the flow. In contrast to classic flapping propulsion, the heaving of the sail section is not perpendicular to the sail's motion through the air. This leads to heave with components parallel and perpendicular to the incident flow. The characteristic motion is recreated in a towing tank where the vortex structures generated by a representative 2-D sail section are observed using Particle Image Velocimetry and the measurement of thrust and lift forces. Amongst other results, we show that the increase in driving force, generated due to heave, is larger for greater apparent wind angles.

  2. Morphology and life cycle of Apatemon hypseleotris species novum from Australia including metacercariae viability and excystment.

    PubMed

    Negm-Eldin, M; Davies, R W

    2002-07-01

    Experimental infection of pigeon squabs and rats with encysted metacercariae from the Western Carp gudgeon (Hypseleotris klunzingeri) showed them to be infected with a new strigeid trematode, Apatemon hypseleotris. Growth and development of A. hypseleotris in pigeons were significantly higher than in rats. Eggs appeared in pigeon faeces within 7-14 days; miracidia hatched within 15-21 days and in the snail Lymnaea tomentosa released within 21 days. Cercariae experimentally encysted in the leeches Helobdella papillornata (86.7%) and Alboglossiphonia australiensis (73.3%). In fish, encystation occurred in the abdominal cavity (100%) and muscles (40%) of Hypseleotris klunzingeri, in the abdominal cavity (80%) and head (30%) of Gambusia affinis and in the abdominal cavity (62.5%) of Oncorhynchus mykiss but no encystation occurred in Moenkhausia pittieri. Freezing (-7 degrees C for 3-7 days or -21 degrees C for 8-12 hours), chilling (6 degrees C for 12 days), boiling (3 minutes) or salting for 3-5 days of encysted metacercariae did not significantly reduce infectivity. In vitro excystation of metacercariae was achieved using pepsin followed by trypsin and/or bile salts.

  3. A Twist in fate: evolutionary comparison of Twist structure and function.

    PubMed

    Castanon, Irinka; Baylies, Mary K

    2002-04-03

    The general requirement to induce mesoderm and allocate cells into different mesodermal tissues such as body muscle or heart is common in many animal embryos. Since the discovery of the twist gene, there has been great progress toward unraveling the molecular mechanisms that control mesoderm specification and differentiation. Twist was first identified in Drosophila as a gene crucial for proper gastrulation and mesoderm formation. In the fly embryo, Twist continues to play additional roles, allocating mesodermal cells into the body wall muscle fate and patterning a subset of these muscles. Twist is also required for proper differentiation of the adult musculature. Twist homologues have been identified in a great variety of organisms, which span the phylogenetic tree. These organisms include other invertebrates such as jellyfish, nematode, leech and lancelet as well as vertebrates such as frog, chick, fish, mouse and human. The Twist family shares both homology in structure across the basic helix-loop-helix domain and in expression during mesoderm and muscle development in most species. Here we review the current state of knowledge of the Twist family and consider how Twist functions during development. Moreover, we highlight experimental evidence that shows common themes that Twist employs during specification and patterning of the mesoderm among evolutionarily distant organisms. Conserved principles and the molecular mechanisms underlying them are discussed.

  4. A preliminary disease survey in the wild Nile crocodile (Crocodylus niloticus) population in the Okavango Delta, Botswana.

    PubMed

    Leslie, A J; Lovely, C J; Pittman, J M

    2011-09-01

    The objective of this study was to conduct a preliminary survey of diseases that might be present in the wild Nile crocodile population in the Okavango Delta, Botswana. Blood samples were collected from crocodiles ranging in size from 34.0 cm to 463.0 cm total length. Samples were examined for blood parasites and underwent a haematological analysis. Before release the crocodiles were examined for various clinical abnormalities. Of the 144 crocodiles examined, none were visibly sick or displayed any signs of disease. No antibodies to Mycoplasma crocodyli were detected. Hepatozoon pettiti was present in 55.3% of blood smears examined, but there was no significant difference in any of the haematological values between the infected and uninfected crocodiles, and a high prevalence of Hepatozoon infection is not uncommon in other species. Only 7.6% of the examined crocodiles were infested with leeches. Further research is required for several of the crocodilian diseases, in particular to elucidate the role of wild crocodilians as reservoirs of infection.

  5. Bottle Traps and Dipnetting: Evaluation of two Sampling Techniques for Assessing Macroinvertebrate Biodiversity in Depressional Wetlands.

    NASA Astrophysics Data System (ADS)

    Serieyssol, C. A.; Bouchard, R. W.; Sealock, A. W.; Rufer, M. M.; Chirhart, J.; Genet, J.; Ferrington, L. C.

    2005-05-01

    Dipnet (DN) sampling is routinely employed for macroinvertebrate bioassessments, however it has been shown that some taxa are more effectively sampled with activity traps, commonly called Bottle Traps (BT). In 2001, the Minnesota Pollution Control Agency used both DN and BT sampling in nine depressional wetlands in the North Central Hardwood Forest Ecoregion to evaluate macroinvertebrate biodiversity for the purpose of assessing water quality and developing biological criteria. Both methods, consisting of five bottle trap samples and two dip net samples per wetland, were collected from each of two sites in each wetland. To determine the performance of each method in documenting biodiversity, we compared taxa and their abundances by wetland, for each type of sample. DN sampling was more effective, with 44 of 140 macroinvertebrate taxa only identified from DN, compared to 14 only from BT. By contrast, BT more effectively collected leeches and beetles, especially active swimmers such as Tropisternus and several genera of Dytiscidae. However, taxa richness patterns for BT and DN were not strongly correlated. Consequently, we conclude these two sampling methods complement each other, providing a better overall picture of macroinvertebrate biodiversity, and should be used jointly when investigating macroinvertebrate biodiversity in depressional wetlands.

  6. Barcoding, types and the Hirudo files: using information content to critically evaluate the identity of DNA barcodes.

    PubMed

    Kvist, Sebastian; Oceguera-Figueroa, Alejandro; Siddall, Mark E; Erséus, Christer

    2010-12-01

    Species identifications based on DNA barcoding rely on the correct identity of previously barcoded specimens, but little attention has been given to whether deposited barcodes include correspondence to the species' name-bearing type. The information content associated with COX1 sequences in the two most commonly used repositories of barcodes, GenBank and the Barcode of Life Data System (BOLD), is often insufficient for subsequent evaluation of the robustness of the identification procedure. We argue that DNA barcoding and taxonomy alike will benefit from more information content in the annotations of barcoded specimens as this will allow for validation and re-evaluation of the initial specimen identification. The aim should be to closely connect specimens from which reference barcodes are generated with the holotype through straight-forward taxonomy, and geographical and genetic correlations. Annotated information should also include voucher specimens and collector/identifier information. We examine two case studies based on empirical data, in which barcoding and taxonomy benefit from increased information content. On the basis of data from the first case study, we designate a barcoded neotype of the European medicinal leech, Hirudo medicinalis, on morphological and geographical grounds.

  7. Carrion fly-derived DNA as a tool for comprehensive and cost-effective assessment of mammalian biodiversity.

    PubMed

    Calvignac-Spencer, Sébastien; Merkel, Kevin; Kutzner, Nadine; Kühl, Hjalmar; Boesch, Christophe; Kappeler, Peter M; Metzger, Sonja; Schubert, Grit; Leendertz, Fabian H

    2013-02-01

    Large-scale monitoring schemes are essential in assessing global mammalian biodiversity, and in this framework, leeches have recently been promoted as an indirect source of DNA from terrestrial mammal species. Carrion feeding flies are ubiquitous and can be expected to feed on many vertebrate carcasses. Hence, we tested whether fly-derived DNA analysis may also serve as a novel tool for mammalian diversity surveys. We screened DNA extracted from 201 carrion flies collected in tropical habitats of Côte d'Ivoire and Madagascar for mammal DNA using multiple PCR systems and retrieved DNA sequences from a diverse set of species (22 in Côte d'Ivoire, four in Madagascar) exploiting distinct forest strata and displaying a broad range of body sizes. Deep sequencing of amplicons generated from pools of flies performed equally well as individual sequencing approaches. We conclude that the analysis of fly-derived DNA can be implemented in a very rapid and cost-effective manner and will give a relatively unbiased picture of local mammal diversity. Carrion flies therefore represent an extraordinary and thus far unexploited resource of mammal DNA, which will probably prove useful for future inventories of wild mammal communities.

  8. The Effect of the Crayfish Orconectes virilis (Crustacea: Decapoda: Cambaridae) in the Decomposition and Succession of Submerged Small Mammal Carrion

    NASA Astrophysics Data System (ADS)

    de Jong, G. D.; Chadwick, J. W.

    2005-05-01

    The role of the crayfish Orconectes virilis in the decomposition of submerged rat carrion and succession of other benthic macroinvertebrates was experimentally investigated in Slaughterhouse Gulch, a small, urban stream in Littleton, Colorado. Crayfish participation in carrion decomposition significantly altered the decomposition rate of the carrion. Nine carcasses were exposed in anchored minnow traps at three degrees of crayfish access: crayfish always present, crayfish having free access, and crayfish excluded. These three treatments required 23 days, 29 days, and 65 days, respectively, for complete decomposition of the rat carrion (<2% original biomass). Sample variability increased with number of crayfish present, especially as decomposition proceeded. Seven other macroinvertebrate taxa were collected from the carcasses, but their presence or absence could not be correlated with crayfish presence. The leech Haemopis marmoratus was generally the first macroinvertebrate to arrive at the carrion, being present in densities of <5 individuals/carcass early in succession and in larger densities (up to 25 individuals/carcass) after extensive decomposition and exposure of the viscera.

  9. On the Dynamics of the Spontaneous Activity in Neuronal Networks

    PubMed Central

    Bonifazi, Paolo; Ruaro, Maria Elisabetta; Torre, Vincent

    2007-01-01

    Most neuronal networks, even in the absence of external stimuli, produce spontaneous bursts of spikes separated by periods of reduced activity. The origin and functional role of these neuronal events are still unclear. The present work shows that the spontaneous activity of two very different networks, intact leech ganglia and dissociated cultures of rat hippocampal neurons, share several features. Indeed, in both networks: i) the inter-spike intervals distribution of the spontaneous firing of single neurons is either regular or periodic or bursting, with the fraction of bursting neurons depending on the network activity; ii) bursts of spontaneous spikes have the same broad distributions of size and duration; iii) the degree of correlated activity increases with the bin width, and the power spectrum of the network firing rate has a 1/f behavior at low frequencies, indicating the existence of long-range temporal correlations; iv) the activity of excitatory synaptic pathways mediated by NMDA receptors is necessary for the onset of the long-range correlations and for the presence of large bursts; v) blockage of inhibitory synaptic pathways mediated by GABAA receptors causes instead an increase in the correlation among neurons and leads to a burst distribution composed only of very small and very large bursts. These results suggest that the spontaneous electrical activity in neuronal networks with different architectures and functions can have very similar properties and common dynamics. PMID:17502919

  10. Effects of Carbon Nanotube Environmental Dispersion on an Aquatic Invertebrate, Hirudo medicinalis.

    PubMed

    Girardello, Rossana; Tasselli, Stefano; Baranzini, Nicolò; Valvassori, Roberto; de Eguileor, Magda; Grimaldi, Annalisa

    2015-01-01

    The recent widespread applications of nanomaterials, because of their properties, opens new scenarios that affect their dispersal in the environment. In particular multiwall carbon nanotubes (MWCNTs), despite their qualities, seem to be harmful for animals and humans. To evaluate possible toxic effects caused by carbon nanotube environmental dispersion, with regard to aquatic compartment, we proposed as experimental model a freshwater invertebrate: Hirudo medicinalis. In the present study we analyse acute and chronic immune responses over a short (1, 3, 6 and 12 hours) and long time (from 1 to 5 weeks) exposure to MWCNTs by optical, electron and immunohistochemical approaches. In the exposed leeches angiogenesis and fibroplasia accompanied by massive cellular migration occur. Immunocytochemical characterization using specific markers shows that in these inflammatory processes the monocyte-macrophages (CD45+, CD68+) are the most involved cells. These immunocompetent cells are characterized by sequence of events starting from the expression of pro-inflammatory cytokines (in particular IL-18), and amyloidogenensis. Our combined experimental approaches, basing on high sensitive inflammatory response can highlight adverse effects of nanomaterials on aquatic organisms and could be useful to assess the MWCNTs impact on aquatic, terrestrial animal and human health.

  11. Mechanosensitive unpaired innexin channels in C. elegans touch neurons.

    PubMed

    Sangaletti, Rachele; Dahl, Gerhard; Bianchi, Laura

    2014-11-15

    Invertebrate innexin proteins share sequence homology with vertebrate pannexins and general membrane topology with both pannexins and connexins. While connexins form gap junctions that mediate intercellular communication, pannexins are thought to function exclusively as plasma membrane channels permeable to both ions and small molecules. Undoubtedly, certain innexins function as gap junction proteins. However, due to sequence similarity to pannexins, it was postulated that innexins also function as plasma membrane channels. Indeed, some of the leech innexins were found to mediate ATP release as unpaired membrane channels with shared pharmacology to pannexin channels. We show here that Caenorhabditis elegans touch-sensing neurons express a mechanically gated innexin channel with a conductance of ∼1 nS and voltage-dependent and K(+)-selective subconductance state. We also show that C. elegans touch neurons take up ethidium bromide through a mechanism that is activated and blocked by innexin activating stimuli and inhibitors, respectively. Finally, we present evidence that touch neurons' innexins are required for cell death induced by chemical ischemia. Our work demonstrates that innexins function as plasma membrane channels in native C. elegans neurons, where they may play a role in pathological cell death.

  12. Parasitism in Pterois volitans (Scorpaenidae) from coastal waters of Puerto Rico, the Cayman Islands, and the Bahamas.

    PubMed

    Ramos-Ascherl, Zullaylee; Williams, Ernest H; Bunkley-Williams, Lucy; Tuttle, Lillian J; Sikkel, Paul C; Hixon, Mark A

    2015-02-01

    Recently, Pterois volitans, a Pacific species of lionfish, invaded the Atlantic Ocean, likely via the aquarium trade. We examined for internal and external parasites 188 individuals from 8 municipalities of Puerto Rico collected during 2009-2012, 91 individuals from Little Cayman, Cayman Islands, collected during the summers of 2010 and 2011, and 47 individuals from Lee Stocking Island, Bahamas, collected during the summer of 2009. In total, 27 parasite taxa were found, including 3 previously reported species from lionfish, the digenean Lecithochirium floridense, the leech Trachelobdella lubrica, and an Excorallana sp. isopod. We also report another 24 previously unreported parasite taxa from lionfish, including digeneans, monogeneans, cestodes, nematodes, isopods, a copepod, and an acanthocephalan. Among these parasites, several were previously unreported at their respective geographic origins: We report 5 new locality records from Puerto Rico, 9 from Cayman Islands, 5 from the Bahamas, 5 from the Caribbean, and 3 from the subtropical western Atlantic region. Three parasites are reported to associate with a fish host for the first time. The parasite faunas of P. volitans among our 3 study sites were quite different; most of the species infecting lionfish were generalists and/or species that infect carnivorous fishes. Although our study did not assess the impact of parasites on the fitness of invasive lionfish, it provides an important early step. Our results provide valuable comparative data for future studies at these and other sites throughout the lionfish's invaded range.

  13. Graded boosting of synaptic signals by low-threshold voltage-activated calcium conductance

    PubMed Central

    Carbó Tano, Martín; Vilarchao, María Eugenia

    2015-01-01

    Low-threshold voltage-activated calcium conductances (LT-VACCs) play a substantial role in shaping the electrophysiological attributes of neurites. We have investigated how these conductances affect synaptic integration in a premotor nonspiking (NS) neuron of the leech nervous system. These cells exhibit an extensive neuritic tree, do not fire Na+-dependent spikes, but express an LT-VACC that was sensitive to 250 μM Ni2+ and 100 μM NNC 55-0396 (NNC). NS neurons responded to excitation of mechanosensory pressure neurons with depolarizing responses for which amplitude was a linear function of the presynaptic firing frequency. NNC decreased these synaptic responses and abolished the concomitant widespread Ca2+ signals. Coherent with the interpretation that the LT-VACC amplified signals at the postsynaptic level, this conductance also amplified the responses of NS neurons to direct injection of sinusoidal current. Synaptic amplification thus is achieved via a positive feedback in which depolarizing signals activate an LT-VACC that, in turn, boosts these signals. The wide distribution of LT-VACC could support the active propagation of depolarizing signals, turning the complex NS neuritic tree into a relatively compact electrical compartment. PMID:25972583

  14. Mechanisms underlying rhythmic locomotion: body-fluid interaction in undulatory swimming.

    PubMed

    Chen, J; Friesen, W O; Iwasaki, T

    2011-02-15

    Swimming of fish and other animals results from interactions of rhythmic body movements with the surrounding fluid. This paper develops a model for the body-fluid interaction in undulatory swimming of leeches, where the body is represented by a chain of rigid links and the hydrodynamic force model is based on resistive and reactive force theories. The drag and added-mass coefficients for the fluid force model were determined from experimental data of kinematic variables during intact swimming, measured through video recording and image processing. Parameter optimizations to minimize errors in simulated model behaviors revealed that the resistive force is dominant, and a simple static function of relative velocity captures the essence of hydrodynamic forces acting on the body. The model thus developed, together with the experimental kinematic data, allows us to investigate temporal and spatial (along the body) distributions of muscle actuation, body curvature, hydrodynamic thrust and drag, muscle power supply and energy dissipation into the fluid. We have found that: (1) thrust is generated continuously along the body with increasing magnitude toward the tail, (2) drag is nearly constant along the body, (3) muscle actuation waves travel two or three times faster than the body curvature waves and (4) energy for swimming is supplied primarily by the mid-body muscles, transmitted through the body in the form of elastic energy, and dissipated into the water near the tail.

  15. Does α-amino-β-methylaminopropionic acid (BMAA) play a role in neurodegeneration?

    PubMed

    Chiu, Alexander S; Gehringer, Michelle M; Welch, Jeffrey H; Neilan, Brett A

    2011-09-01

    The association of α-amino-β-methylaminopropionic acid (BMAA) with elevated incidence of amyotrophic lateral sclerosis/Parkinson's disease complex (ALS/PDC) was first identified on the island of Guam. BMAA has been shown to be produced across the cyanobacterial order and its detection has been reported in a variety of aquatic and terrestrial environments worldwide, suggesting that it is ubiquitous. Various in vivo studies on rats, mice, chicks and monkeys have shown that it can cause neurodegenerative symptoms such as ataxia and convulsions. Zebrafish research has also shown disruption to neural development after BMAA exposure. In vitro studies on mice, rats and leeches have shown that BMAA acts predominantly on motor neurons. Observed increases in the generation of reactive oxygen species (ROS) and Ca(2+) influx, coupled with disruption to mitochondrial activity and general neuronal death, indicate that the main mode of activity is via excitotoxic mechanisms. The current review pertaining to the neurotoxicity of BMAA clearly demonstrates its ability to adversely affect neural tissues, and implicates it as a potentially significant compound in the aetiology of neurodegenerative disease. When considering the potential adverse health effects upon exposure to this compound, further research to better understand the modes of toxicity of BMAA and the environmental exposure limits is essential.

  16. Medicinal use and social status of the soap berry endod (Phytolacca dodecandra) in Ethiopia.

    PubMed

    Esser, Kjell B; Semagn, Kassa; Wolde-Yohannes, Legesse

    2003-04-01

    Berries from Phytolacca dodecandra L'Herit. (endod in Amharic) offer a readily available molluscicide to control schistosomiasis. Parts of the endod plant have been used as a detergent and as traditional medicine for centuries in Ethiopia. An interview survey was performed in the highlands of Ethiopia to provide information on the distribution of the plant, people's traditional use of it, their perception of the plant, and the potential for increased production and use of endod as a soap for indirect control of schistosomiasis. People of all ages report that they are familiar with the plant and its detergent and medicinal uses. The plant is largely disappearing from unprotected areas due to land clearing. Younger people appear to use endod as a soap whenever it is available. Older women prefer commercial soap and consider endod to be associated with poor people. Common medicinal uses include treatment of skin itching (ringworm), abortion, gonorrhea, leeches, intestinal worms, anthrax and rabies. Two thirds of the people express interest in cultivating endod for personal use if supplied with rooted cuttings. Increased cultivation of endod and use of berries for washing might be possible if information about schistosomiasis and its control is disseminated among people. Preference for commercial soap and lack of land for cultivation are major obstacles for increasing the availability and use of endod.

  17. Discovery of anticoagulant drugs: a historical perspective.

    PubMed

    Gómez-Outes, Antonio; Suárez-Gea, Ma Luisa; Calvo-Rojas, Gonzalo; Lecumberri, Ramón; Rocha, Eduardo; Pozo-Hernández, Carmen; Terleira-Fernández, Ana Isabel; Vargas-Castrillón, Emilio

    2012-06-01

    The history of the traditional anticoagulants is marked by both perseverance and serendipity. The anticoagulant effect of heparin was discovered by McLean in 1915, while he was searching for a procoagulant in dog liver. Link identified dicumarol from spoiled sweet clover hay in 1939 as the causal agent of the sweet clover disease, a hemorrhagic disorder in cattle. Hirudin extracts from the medicinal leech were first used for parenteral anticoagulation in the clinic in 1909, but their use was limited due to adverse effects and difficulties in achieving highly purified extracts. Heparins and coumarins (i.e.: warfarin, phenprocoumon, acenocoumarol) have been the mainstay of anticoagulant therapy for more than 60 years. Over the past decades, the drug discovery paradigm has shifted toward rational design following a target-based approach, in which specific proteins, or "targets", are chosen on current understandings of pathophysiology, small molecules that inhibit the target's activity may be identified by high-throughput screening and, in selected cases, these new molecules can be developed further as drugs. Despite the application of rational design, serendipity has still played a significant role in some of the new discoveries. This review will focus on the discovery of the main anticoagulant drugs in current clinical use, like unfractionated heparin, low-molecular-weight heparins, fondaparinux, coumarins (i.e.: warfarin, acenocoumarol, phenprocoumon), parenteral direct thrombin inhibitors (DTIs) (i.e.: argatroban, recombinant hirudins, bivalirudin), oral DTIs (i.e.: dabigatran) and oral direct factor Xa inhibitors (i.e.: rivaroxaban, apixaban).

  18. Measurement of hematological, clinical chemistry, and infection parameters from hirudinized blood collected in universal blood sampling tubes.

    PubMed

    Menssen, H D; Brandt, N; Leben, R; Müller, F; Thiel, E; Melber, K

    2001-08-01

    Hirudin, the anticoagulatory polypeptide of the leech Hirudo medicinalis, strongly inhibits thrombus formation by specifically interacting with thrombin. For diagnostic purposes, hirudin should be superior to other anticlotting compounds because it only minimally alters the mineral, protein, and cellular blood constituents. To test this hypothesis, hirudinized and routinely processed venous blood from 80 healthy volunteers and patients was subjected to a variety of automated blood tests. A strong correlation was found between the results of automated complete blood counts obtained from K(2)-ethylenediaminetetraacetic acid (EDTA) anticoagulated and hirudinized blood (1000 antithrombin units [ATU] hirudin/ml). In addition, clinical chemistry and serological infection parameters (asparlat amintransferase [ASAT], lactate dehydrogenase [LDH], sodium, and so on, and antibodies against hepatitis B and C and human immunodeficiency virus [HIV]1/2, respectively) correlated well when measured in serum as compared with hirudinized plasma. Contrary to single clotting factors, global coagulation parameters (activated partial thromboplastin time [aPTT], prothrombin time [PT]) could not be measured in hirudinized blood. Recombinant hirudin neither interfered with immunophenotyping of mononuclear cells using FACScan analysis, nor did it alter the detection of Wilms' tumor gene expression by RT-PCR technology even at high doses (5000 ATU hirudin). Thus, a hirudin-containing blood sampling tube can be designed as a universal blood sampling tube (UBT) for testing the majority of diagnostic blood parameters.

  19. An Optically Stabilized Fast-Switching Light Emitting Diode as a Light Source for Functional Neuroimaging

    PubMed Central

    Wagenaar, Daniel A.

    2012-01-01

    Neuroscience research increasingly relies on optical methods for evoking neuronal activity as well as for measuring it, making bright and stable light sources critical building blocks of modern experimental setups. This paper presents a method to control the brightness of a high-power light emitting diode (LED) light source to an unprecedented level of stability. By continuously monitoring the actual light output of the LED with a photodiode and feeding the result back to the LED's driver by way of a proportional-integral controller, drift was reduced to as little as 0.007% per hour over a 12-h period, and short-term fluctuations to 0.005% root-mean-square over 10 seconds. The LED can be switched on and off completely within 100 s, a feature that is crucial when visual stimuli and light for optical recording need to be interleaved to obtain artifact-free recordings. The utility of the system is demonstrated by recording visual responses in the central nervous system of the medicinal leech Hirudo verbana using voltage-sensitive dyes. PMID:22238663

  20. Effects of Carbon Nanotube Environmental Dispersion on an Aquatic Invertebrate, Hirudo medicinalis

    PubMed Central

    Girardello, Rossana; Tasselli, Stefano; Baranzini, Nicolò; Valvassori, Roberto; de Eguileor, Magda; Grimaldi, Annalisa

    2015-01-01

    The recent widespread applications of nanomaterials, because of their properties, opens new scenarios that affect their dispersal in the environment. In particular multiwall carbon nanotubes (MWCNTs), despite their qualities, seem to be harmful for animals and humans. To evaluate possible toxic effects caused by carbon nanotube environmental dispersion, with regard to aquatic compartment, we proposed as experimental model a freshwater invertebrate: Hirudo medicinalis. In the present study we analyse acute and chronic immune responses over a short (1, 3, 6 and 12 hours) and long time (from 1 to 5 weeks) exposure to MWCNTs by optical, electron and immunohistochemical approaches. In the exposed leeches angiogenesis and fibroplasia accompanied by massive cellular migration occur. Immunocytochemical characterization using specific markers shows that in these inflammatory processes the monocyte-macrophages (CD45+, CD68+) are the most involved cells. These immunocompetent cells are characterized by sequence of events starting from the expression of pro-inflammatory cytokines (in particular IL-18), and amyloidogenensis. Our combined experimental approaches, basing on high sensitive inflammatory response can highlight adverse effects of nanomaterials on aquatic organisms and could be useful to assess the MWCNTs impact on aquatic, terrestrial animal and human health. PMID:26636582

  1. Two new species of Austrobdella (Hirudinida: Piscicolidae) from Chile.

    PubMed

    Williams, Julianne I; Urrutia, Paula M; Burreson, Eugene M

    2007-02-01

    Austrobdella coliumicus n. sp. is described from Coliumo Bay, Chile. It is characterized by a continuous, external coelomic canal (= marginal lacuna), 5 pairs of testisacs, accessory gland cells, a body not distinctly divided into trachelosome and urosome, 2 pairs of dorsal ocelli on the trachelosome, dorsal and ventral segmental ocelli present on the urosome, green overall pigmentation with transverse brown bands, and the absence of conducting tissue. Austrobdella coliumicus is distinguished from other species of Austrobdella by the presence of 2 pairs of ocelli on the trachelosome and a more cylindrical body. It is unusual that this leech was collected from inside the mantle cavity of the razor clam, Ensis macha. Austrobdella losmoliniensis n. sp. is described from the electric ray, Discopyge tschudii, collected at Los Molinos, Chile. It is characterized by a continuous, external coelomic canal; 5 pairs of testisacs; accessory gland cells; a body distinctly divided into trachelosome and urosome; 1 pair of eyes on the oral sucker; overall black pigmentation with unpigmented areas; and the absence of conducting tissue. Austrobdella losmoliniensis can be distinguished from other species of Austrobdella by the combination of 1 pair of eyes on the oral sucker and black pigmentation.

  2. Haemogregarines from western Palaearctic freshwater turtles (genera Emys, Mauremys) are conspecific with Haemogregarina stepanowi Danilewsky, 1885.

    PubMed

    Dvořáková, Nela; Kvičerová, Jana; Papoušek, Ivo; Javanbakht, Hossein; Tiar, Ghoulem; Kami, Hajigholi; Široký, Pavel

    2014-04-01

    The majority of Haemogregarina species have been based on the morphology of their erythrocytic stages and supposed strict host specificity. The quantity of species with a limited number of overlapping diagnostic traits has led to a considerable mess in haemogregarine taxonomy and significant synonymy. We analysed host specificity, intra- and interspecific variability, evolutionary relationships, and the distribution of the type species of the genus Haemogregarina--H. stepanowi. The morphology of blood stages and 18S rDNA sequences of this haemogregarine from four western Palaearctic hard-shelled freshwater turtles (Emys orbicularis, Mauremys caspica, Mauremys leprosa and Mauremys rivulata) were compared with Haemogregarina balli. Additional sequences of 18S rDNA of Haemogregarina-like isolates collected from three species of African hinged terrapins (genus Pelusios) were used to enlarge the dataset for phylogenetic analyses. Thirteen sequences (1085 bp) of Haemogregarina representing all four western Palaearctic turtle species were identical, corresponding to H. stepanowi, which is closely related to the Nearctic species H. balli. In our analyses, Haemogregarina spp. constituted a monophyletic clade sister to the genus Hepatozoon. Haemogregarina stepanowi possesses a wide distribution range from the Maghreb, through Europe, Turkey and the Middle East to Iran. We consider that the genus Haemogregarina has a low host specificity crossing the family level of its vertebrate hosts and that its distribution is likely to be linked to the vector and definitive host--the leech.

  3. The evolution and comparative neurobiology of endocannabinoid signalling

    PubMed Central

    Elphick, Maurice R.

    2012-01-01

    CB1- and CB2-type cannabinoid receptors mediate effects of the endocannabinoids 2-arachidonoylglycerol (2-AG) and anandamide in mammals. In canonical endocannabinoid-mediated synaptic plasticity, 2-AG is generated postsynaptically by diacylglycerol lipase alpha and acts via presynaptic CB1-type cannabinoid receptors to inhibit neurotransmitter release. Electrophysiological studies on lampreys indicate that this retrograde signalling mechanism occurs throughout the vertebrates, whereas system-level studies point to conserved roles for endocannabinoid signalling in neural mechanisms of learning and control of locomotor activity and feeding. CB1/CB2-type receptors originated in a common ancestor of extant chordates, and in the sea squirt Ciona intestinalis a CB1/CB2-type receptor is targeted to axons, indicative of an ancient role for cannabinoid receptors as axonal regulators of neuronal signalling. Although CB1/CB2-type receptors are unique to chordates, enzymes involved in biosynthesis/inactivation of endocannabinoids occur throughout the animal kingdom. Accordingly, non-CB1/CB2-mediated mechanisms of endocannabinoid signalling have been postulated. For example, there is evidence that 2-AG mediates retrograde signalling at synapses in the nervous system of the leech Hirudo medicinalis by activating presynaptic transient receptor potential vanilloid-type ion channels. Thus, postsynaptic synthesis of 2-AG or anandamide may be a phylogenetically widespread phenomenon, and a variety of proteins may have evolved as presynaptic (or postsynaptic) receptors for endocannabinoids. PMID:23108540

  4. The Reverse Superficial Sural Artery Flap Revisited for Complex Lower Extremity and Foot Reconstruction

    PubMed Central

    Sugg, Kristoffer B.; Schaub, Timothy A.; Concannon, Matthew J; Cederna, Paul S.

    2015-01-01

    Background: Soft-tissue defects of the distal lower extremity and foot present significant challenges to the reconstructive surgeon. The reverse superficial sural artery flap (RSSAF) is a popular option for many of these difficult wounds. Our initial experience with this flap at multiple institutions resulted in a 50% failure rate, mostly because of critical venous congestion. To overcome this, we have modified our operative technique, which has produced a more reliable flap. Methods: All patients reconstructed with an RSSAF between May 2002 and September 2013 were retrospectively reviewed. In response to a high rate of venous congestion in an early group of patients, we adopted a uniform change in operative technique for a late group of patients. A key modification was an increase in pedicle width to at least 4 cm. Outcomes of interest included postoperative complications and limb salvage rate. Results: Twenty-seven patients were reconstructed with an RSSAF (n = 12 for early group, n = 15 for late group). Salvage rate in the early group was 50% compared with 93% in the late group (P = 0.02). Postoperative complications (75% vs. 67%, P = 0.70) were similar between groups. Venous congestion that required leech therapy was 42% in the early group (n = 5) and 0% in the late group (P = 0.01). Conclusions: Venous congestion greatly impairs the survival of the RSSAF. A pedicle width of at least 4 cm is recommended to maintain venous drainage and preserve flap viability. PMID:26495232

  5. Reporter gene expression in dendritic cells after gene gun administration of plasmid DNA.

    PubMed

    Watkins, Craig; Hopkins, John; Harkiss, Gordon

    2005-07-21

    Dendritic cells (DC) play an integral role in plasmid DNA vaccination. However, the interaction between plasmid DNA and DC in vivo is incompletely understood. In this report, we utilise the sheep pseudoafferent cannulation model to examine the interaction between plasmid DNA encoding enhanced green fluorescent protein (pEGFP) and afferent lymph DC (ALDC) following gene gun administration. The results show that peaks of fluorescent ALDC tended to appear around days 1-4 and 9-13, then erratically thereafter for up to 2 months. Phenotypic analysis showed that EGFP+ ALDC expressed MHC class II, WC6, CD1b, and SIRPalpha markers. Plasmid, detected by PCR, was found in lymph cells and cell-free plasma on a daily basis, and was present variably for up to 2 months. Plasmid was also detected in purified CD1b+ ALDC, but the presence of plasmid did not correlate with EGFP expression by ALDC. Free EGFP in afferent lymph plasma was detectable by luminometry only after three administrations of the plasmid. The results show that gene gun administered pEGFP persisted for extended periods after a single administration, leeching out of skin on a daily basis. The plasmid was associated with both the cellular and fluid components of afferent lymph. EGFP protein appeared in afferent lymph in a pulsatile manner, but associated only with ALDC.

  6. Laboratory and Field Evaluation of the Molluscicidal Properties of Phytolacca dodecandra

    PubMed Central

    Lemma, Aklilu

    1970-01-01

    Dried berries of endod (Phytolacca dodecandra) (known also as soapberry) are widely used in Ethiopia instead of soap for laundering clothes. It was observed that in natural bodies of water where endod had been used there was a high mortality of snails. Subsequently, the molluscicidal potencies of various parts of male and female endod plants were determined and the berries were found to be the most potent. The potency of endod remained stable over a wide range of temperatures and pH values, in the presence of various concentrations of river-bed mud and after ultraviolet irradiation of solutions. The toxicity of endod to mammals and plants has been shown to be very low. Its toxicity to snail eggs also is low but it has been shown that this difficulty can be overcome in the field by repeated treatments. Endod kills leeches and schistosome cercariae and miracidia at very low concentrations. Comparative tests with endod and several standard molluscicides have given encouraging results. Being a natural product, endod could become a cheap and effective means of controlling schistosomiasis in certain areas since, under suitable climatic conditions, the plant grows rapidly and bears fruit twice a year. ImagesFIG. 1 PMID:5310955

  7. Pore opening dynamics in the exocytosis of serotonin

    NASA Astrophysics Data System (ADS)

    Ramirez-Santiago, Guillermo; Cercos, Montserrat G.; Martinez-Valencia, Alejandro; Salinas Hernandez, Israel; Rodríguez-Sosa, Leonardo; de-Miguel, Francisco F.

    2015-03-01

    The current view of the exocytosis of transmitter molecules is that it starts with the formation of a fusion pore that connects the intravesicular and the extracellular spaces, and is completed by the release of the rest of the transmitter contained in the vesicle upon the full fusion and collapse of the vesicle with the plasma membrane. However, under certain circumstances, a rapid closure of the pore before the full vesicle fusion produces only a partial release of the transmitter. Here we show that whole release of the transmitter occurs through fusion pores that remain opened for tens of milliseconds without vesicle collapse. This was demonstrated through amperometric measurements of serotonin release from electrodense vesicles in the axon of leech Retzius neurons and mathematical modelling. By modeling transmitter release with a diffusion equation subjected to boundary conditions that are defined by the experiment, we showed that those pores with a fast half rise time constant remained opened and allowed the full quantum release without vesicle collapse, whereas pores with a slow rise time constant closed rapidly, thus producing partial release. We conclude that a full transmitter release may occur through the fusion pore in the absence of vesicle collapse. This work was founded by a DGAPA-UNAM grants IN200914 and IN118410 CONACYT GRANT 130031, and CONACyT doctoral fellowships.

  8. Distribution and ecology of Dreissena polymorpha (pallas) and Dreissena bugensis (andrusov) in the upper Volga basin

    USGS Publications Warehouse

    Shcherbina, G. Kh; Buckler, D.R.

    2006-01-01

    This paper presents data on contemporary distribution patterns of two species of Dreissenidae, the zebra mussel (Dreissena polymorpha) and the Quagga mussel (Dreissena bugensis), and their role in ecosystem processes in the Ivan'kovo, Uglich, Rybinsk, and Gorky Reservoirs of the Upper Volga River basin. The role of zebra mussel was also studied in experimental mesocosms of 15 m3. Maximum abundance and species diversity of macroinvertebrates, especially of leeches, polychaetes, crustaceans, and heterotopic insects, were attained in the portions of reservoirs where Dreissenidae were present and in experimental mesocosms where zebra mussel biomass was the highest. In the mesocosm studies, the presence of zebra mussel druses (colonies) provided shelter for macroinvertebrates, reducing their vulnerability to predation by perch (Perca fluviatills) larvae and yearlings, thereby increasing macroinvertebrate species diversity. It was shown that in addition to its role in aquatic biocenosis (ecological community) formation and water purification, Dreissenidae are important food objects for benthophagous fishes, especially roach (Rutilus rutilus). Examination of intestines of benthophagous fishes showed that the length of Dreissenidae ranged from 5 to 20 mm in roach; from 4 to 14 mm in silver bream (Blicca bjoerkna), and from 2 to 10 mm in bream (Abramis brama). The largest mussels consumed were Quagga mussels up to 30 mm, noted in the predatory cyprinid, ide (Leuciscus idus). Copyright ?? 2006 by ASTM International.

  9. Insights into bilaterian evolution from three spiralian genomes

    SciTech Connect

    Simakov, Oleg; Marletaz, Ferdinand; Cho, Sung-Jin; Edsinger-Gonzales, Eric; Havlak, Paul; Hellsten, Uffe; Kuo, Dian-Han; Larsson, Tomas; Lv, Jie; Arendt, Detlev; Savage, Robert; Osoegawa, Kazutoyo; de Jong, Pieter; Grimwood, Jane; Chapman, Jarrod A.; Shapiro, Harris; Otillar, Robert P.; Terry, Astrid Y.; Boore, Jeffrey L.; Grigoriev, Igor V.; Lindberg, David R.; Seaver, Elaine C.; Weisblat, David A.; Putnam, Nicholas H.; Rokhsar, Daniel S.; Aerts, Andrea

    2012-01-07

    Current genomic perspectives on animal diversity neglect two prominent phyla, the molluscs and annelids, that together account for nearly one-third of known marine species and are important both ecologically and as experimental systems in classical embryology1, 2, 3. Here we describe the draft genomes of the owl limpet (Lottia gigantea), a marine polychaete (Capitella teleta) and a freshwater leech (Helobdella robusta), and compare them with other animal genomes to investigate the origin and diversification of bilaterians from a genomic perspective. We find that the genome organization, gene structure and functional content of these species are more similar to those of some invertebrate deuterostome genomes (for example, amphioxus and sea urchin) than those of other protostomes that have been sequenced to date (flies, nematodes and flatworms). The conservation of these genomic features enables us to expand the inventory of genes present in the last common bilaterian ancestor, establish the tripartite diversification of bilaterians using multiple genomic characteristics and identify ancient conserved long- and short-range genetic linkages across metazoans. Superimposed on this broadly conserved pan-bilaterian background we find examples of lineage-specific genome evolution, including varying rates of rearrangement, intron gain and loss, expansions and contractions of gene families, and the evolution of clade-specific genes that produce the unique content of each genome.

  10. Parasitic zoonoses in Papua New Guinea.

    PubMed

    Owen, I L

    2005-03-01

    Relatively few species of zoonotic parasites have been recorded in humans in Papua New Guinea. A greater number of potentially zoonotic species, mostly nematodes, occur in animals but are yet to be reported from humans. Protozoa is the best represented group of those infecting man, with Giardia duodenalis, Cryptosporidium parvum, Cyclospora cayetanesis, Toxoplasma gondii, Sarcocystis spp., Entamoeba polecki, Balantidium coli and, possibly, Blastocystis hominis. The only zoonotic helminths infecting humans include the trematode Paragonimus westermani, the cestodes Hymenolepis nana, H. diminuta and the sparganum larva of Spirometra erinacea, and the nematodes Trichinella papuae and Angiostrongylus cantonensis and, possibly, Ascaris suum. Other groups represented are Acanthocephala (Macracanthorhynchus hirudinaceus)), insects (Chrysomya bezziana, Cimex sp., Ctenocephalides spp.), and mites (Leptotrombidium spp. and, possibly Sarcoptes scabiei, and Demodex sp.). One leech (Phytobdella lineata) may also be considered as being zoonotic. The paucity of zoonotic parasite species can be attributed to long historical isolation of the island of New Guinea and its people, and the absence until recent times of large placental mammals other than pig and dog. Some zoonotic helminths have entered the country with recent importation of domestic animals, in spite of quarantine regulations, and a few more (two cestodes, one nematode and one tick) are poised to enter from neighbouring countries, given the opportunity. Improvement in water supplies, human hygiene and sanitation would reduce the prevalence of many of these parasites, and thorough cooking of meat would lessen the risk of infection by some others.

  11. Serotonin release from the neuronal cell body and its long-lasting effects on the nervous system.

    PubMed

    De-Miguel, Francisco F; Leon-Pinzon, Carolina; Noguez, Paula; Mendez, Bruno

    2015-07-05

    Serotonin, a modulator of multiple functions in the nervous system, is released predominantly extrasynaptically from neuronal cell bodies, axons and dendrites. This paper describes how serotonin is released from cell bodies of Retzius neurons in the central nervous system (CNS) of the leech, and how it affects neighbouring glia and neurons. The large Retzius neurons contain serotonin packed in electrodense vesicles. Electrical stimulation with 10 impulses at 1 Hz fails to evoke exocytosis from the cell body, but the same number of impulses at 20 Hz promotes exocytosis via a multistep process. Calcium entry into the neuron triggers calcium-induced calcium release, which activates the transport of vesicle clusters to the plasma membrane. Exocytosis occurs there for several minutes. Serotonin that has been released activates autoreceptors that induce an inositol trisphosphate-dependent calcium increase, which produces further exocytosis. This positive feedback loop subsides when the last vesicles in the cluster fuse and calcium returns to basal levels. Serotonin released from the cell body is taken up by glia and released elsewhere in the CNS. Synchronous bursts of neuronal electrical activity appear minutes later and continue for hours. In this way, a brief train of impulses is translated into a long-term modulation in the nervous system.

  12. [Healing Dental and Oral Problems by Remedies of Animal and of Human Origin].

    PubMed

    Kaán, Miklós

    2015-01-01

    Use of matierials of animal or human origin in dentistry (and generally in medicine) these days is regarded as an unusal way of intervention. However in earlier times, different tissues, parts, products and organs of animals were frequently used in healing. Some of these methods were rooted in magical thinking. As analogical treatments--based on similarity or analogy--e.g. powder of horn or teeth of pike was used for the treatment of decayed teeth and different worms, maggots, veenies were applied against "toothworm". By difficult eruption of primary teeth bone marrow or brain mixed with cockridge-blood and goatmilk was a widely used medicine. Butter and honey were able to help the growing of teeth, as well. Parts of frog (fe: flippers) were also components of curing materials. Egg as the symbol of life was often an ingredient of medicaments. For the treatment of inflamed gum different animal materials were used, like chin and teeth of wolf, pike, crayfish, milk, honey, human saliva etc. Animal or human stools, mucks (containing enzymes) did one's bit in healing of oral and dental illnesses and were applied as fomentation or swathing. Placing a leech on the inflamed face was a common procedure in the past even as the use of earwax in lipnook. In our days tissues, parts or products of animals (or human beings) usually never allowed to get into contact with the body of patients. It's a much safer routine, at the same time however a precious traditional knowledge vanishes forever.

  13. Old and new natural products as the source of modern antithrombotic drugs.

    PubMed

    Beretz, A; Cazenave, J P

    1991-10-01

    Natural compounds have been the first historical source of antithrombotic compounds (heparin, vitamin K antagonists, streptokinase, urokinase); molecules extracted from plants or animals still provide some of the most original and promising approaches for the discovery of new drugs in this class. In this review, we will briefly describe three examples of current research trends that could lead to the development of new antithrombotic drugs of natural origin. Flavonoids have been shown to be inhibitors of cyclic nucleotide phosphodiesterase; this enzymatic activity is one of the main mechanisms of inhibition of aggregation of blood platelets by flavonoids. Some of these compounds could represent templates for the development of new inhibitors of platelet activation. Garlic ( ALLIUM SATIVUM) has been shown to inhibit platelet aggregation IN VIVO and IN VITRO; a number of active principles has now been identified and their mechanisms of action are currently being explored. An ancient remedy, the medicinal leech ( HIRUDO MEDICINALIS), has been found to contain several potent anticoagulant proteins. Among them, hirudin, a polypeptide of 65 amino acids, has been identified as one of the most potent inhibitors of thrombin. The production of sufficient amounts of hirudin through molecular biology techniques has now allowed the performance of clinical trials. These three examples show that careful consideration of biochemical, ethnopharmacological, or toxicological properties of natural products can still constitute a valuable basis for the development of new drugs.

  14. Old and new natural products as the source of modern antithrombotic drugs.

    PubMed

    Beretz, A; Cazenave, J P

    1991-10-01

    Natural compounds have been the first historical source of antithrombotic compounds (heparin, vitamin K antagonists, streptokinase, urokinase); molecules extracted from plants or animals still provide some of the most original and promising approaches for the discovery of new drugs in this class. In this review, we will briefly describe three examples of current research trends that could lead to the development of new antithrombotic drugs of natural origin. Flavonoids have been shown to be inhibitors of cyclic nucleotide phosphodiesterase; this enzymatic activity is one of the main mechanisms of inhibition of aggregation of blood platelets by flavonoids. Some of these compounds could represent templates for the development of new inhibitors of platelet activation. Garlic (Allium sativum) has been shown to inhibit platelet aggregation in vivo and in vitro; a number of active principles has now been identified and their mechanisms of action are currently being explored. An ancient remedy, the medicinal leech (Hirudo medicinalis), has been found to contain several potent anticoagulant proteins. Among them, hirudin, a polypeptide of 65 amino acids, has been identified as one of the most potent inhibitors of thrombin. The production of sufficient amounts of hirudin through molecular biology techniques has now allowed the performance of clinical trials. These three examples show that careful consideration of biochemical, ethnopharmacological, or toxicological properties of natural products can still constitute a valuable basis for the development of new drugs.

  15. Desmoteplase: discovery, insights and opportunities for ischaemic stroke.

    PubMed

    Medcalf, Robert L

    2012-01-01

    Nature has provided a vast array of bioactive compounds that have been exploited for either diagnostic or therapeutic use. The field of thrombosis and haemostasis in particular has enjoyed much benefit from compounds derived from nature, notably from snakes and blood-feeding animals. Indeed, the likelihood that blood-feeding animals would harbour reagents with relevant pharmacology and with potential pharmaceutical benefit in haemostasis was not too far-fetched. Blood-feeding animals including leeches and ticks have evolved a means to keep blood from clotting or to at least maintain the liquid state, and some of these have been the subject of clinical development. A more recent example of this has been the saliva of the common vampire bat Desmodus rotundus, which has proven to harbour a veritable treasure trove of novel regulatory molecules. Among the bioactive compounds present is a fibrinolytic compound that was shown over 40 years ago to be a potent plasminogen activator. Studies of this vampire bat-derived plasminogen activator, more recently referred to as desmoteplase, revealed that this protease shared a number of structural and functional similarities to the human fibrinolytic protease, tissue-type plasminogen activator (t-PA) yet harboured critically important differences that have rendered this molecule attractive for clinical development for patients with ischaemic stroke.

  16. Mechanosensitive unpaired innexin channels in C. elegans touch neurons

    PubMed Central

    Sangaletti, Rachele; Dahl, Gerhard

    2014-01-01

    Invertebrate innexin proteins share sequence homology with vertebrate pannexins and general membrane topology with both pannexins and connexins. While connexins form gap junctions that mediate intercellular communication, pannexins are thought to function exclusively as plasma membrane channels permeable to both ions and small molecules. Undoubtedly, certain innexins function as gap junction proteins. However, due to sequence similarity to pannexins, it was postulated that innexins also function as plasma membrane channels. Indeed, some of the leech innexins were found to mediate ATP release as unpaired membrane channels with shared pharmacology to pannexin channels. We show here that Caenorhabditis elegans touch-sensing neurons express a mechanically gated innexin channel with a conductance of ∼1 nS and voltage-dependent and K+-selective subconductance state. We also show that C. elegans touch neurons take up ethidium bromide through a mechanism that is activated and blocked by innexin activating stimuli and inhibitors, respectively. Finally, we present evidence that touch neurons' innexins are required for cell death induced by chemical ischemia. Our work demonstrates that innexins function as plasma membrane channels in native C. elegans neurons, where they may play a role in pathological cell death. PMID:25252948

  17. Cells showing immunoreactivity for calcitonin or calcitonin gene-related peptide (CGRP) in the central nervous system of some invertebrates.

    PubMed

    Sasayama, Y; Katoh, A; Oguro, C; Kambegawa, A; Yoshizawa, H

    1991-09-01

    In the central nervous system of some species of several invertebrate phyla, including land planarians (Platyhelminthes), ribbon worms (Nemertina), slugs (Mollusca), polychaetes, earthworms and leeches (Annelida), pill bugs (Arthropoda), and beard worms (Pogonophora), salmon calcitonin-immunoreactive cells and rat calcitonin gene-related peptide (CGRP)-immunoreactive cells were found by immunohistochemistry. These immunoreactive cells were located in the region surrounding the neuropile, although the sizes of the cells varied according to species. Some of them were round or polygonal and regarded as apolar nerve cells because of their lack of cytoplasmic processes, whereas others were spindle-shaped or elongated, being comparable with unipolar nerve cells because of extension of their cytoplasmic processes in the direction of the neuropile. In some cases, it was noted that the cytoplasmic processes had complicated branches or formed loop-like structures at their ends. These observations suggest that a calcitonin-like or CGRP-like substance is extensively present in invertebrates as well as vertebrates.

  18. Homoclinic Spike adding in a neuronal model in the presence of noise

    NASA Astrophysics Data System (ADS)

    Fuwape, Ibiyinka; Neiman, Alexander; Shilnikov, Andrey

    2008-03-01

    We study the influence of noise on a spike adding transitions within the bursting activity in a Hodgkin-Huxley-type model of the leech heart interneuron. Spike adding in this model occur via homoclinic bifurcation of a saddle periodic orbit. Although narrow chaotic regions are observed near bifurcation transition, overall bursting dynamics is regular and is characterized by a constant number of spikes per burst. Experimental studies, however, show variability of bursting patterns whereby number of spikes per burst varies randomly. Thus, introduction of external synaptic noise is a necessary step to account for variability of burst durations observed experimentally. We show that near every such transition the neuron is highly sensitive to random perturbations that lead to and enhance broadly the regions of chaotic dynamics of the cell. For each spike adding transition there is a critical noise level beyond which the dynamics of the neuron becomes chaotic throughout the entire region of the given transition. Noise-induced chaotic dynamics is characterized in terms of the Lyapunov exponents and the Shannon entropy and reflects variability of firing patterns with various numbers of spikes per burst, traversing wide range of the neuron's parameters

  19. The Insect Chemoreceptor Superfamily Is Ancient in Animals.

    PubMed

    Robertson, Hugh M

    2015-11-01

    The insect chemoreceptor superfamily consists of 2 gene families, the highly diverse gustatory receptors (GRs) found in all arthropods with sequenced genomes and the odorant receptors that evolved from a GR lineage and have been found only in insects to date. Here, I describe relatives of the insect chemoreceptor superfamily, specifically the basal GR family, in diverse other animals, showing that the superfamily dates back at least to early animal evolution. GR-Like (GRL) genes are present in the genomes of the placozoan Trichoplax adhaerens, an anemone Nematostella vectensis, a coral Acropora digitifera, a polychaete Capitella teleta, a leech Helobdella robusta, the nematode Caenorhabditis elegans (and many other nematodes), 3 molluscs (a limpet Lottia gigantea, an oyster Crassostrea gigas, and the sea hare Aplysia californica), the sea urchin Strongylocentrotus purpuratus, and the sea acorn Saccoglossus kowalevskii. While some of these animals contain multiple divergent GRL lineages, GRLs have been lost entirely from other animal lineages such as vertebrates. GRLs are absent from the ctenophore Mnemiopsis leidyi, the demosponge Amphimedon queenslandica, and 2 available chaonoflagellate genomes, so it remains unclear whether this superfamily originated before or during animal evolution.

  20. Management of complications and compromised free flaps following major head and neck surgery.

    PubMed

    Kucur, Cuneyt; Durmus, Kasim; Uysal, Ismail O; Old, Matthew; Agrawal, Amit; Arshad, Hassan; Teknos, Theodoros N; Ozer, Enver

    2016-01-01

    Microvascular free flaps are preferred for most major head and neck reconstruction surgeries because of better functional outcomes, improved esthetics, and generally higher success rates. Numerous studies have investigated measures to prevent flap loss, but few have evaluated the optimal treatment for free flap complications. This study aimed to determine the complication rate after free flap reconstructions and discusses our management strategies. Medical records of 260 consecutive patients who underwent free flap reconstructions for head and neck defects between July 2006 and June 2010 were retrospectively reviewed for patient and surgical characteristics and postoperative complications. The results revealed that microvascular free flaps were extremely reliable, with a 3.5 % incidence of flap failure. There were 78 surgical site complications. The most common complication was neck wound infection, followed by dehiscence, vascular congestion, abscess, flap necrosis, hematoma, osteoradionecrosis, and brisk bleeding. Twenty patients with poor wound healing received hyperbaric oxygen therapy, which was ineffective in three patients who eventually experienced complete flap loss. Eleven patients with vascular congestion underwent medicinal leech therapy, which was effective. Among the 78 patients with complications, 44 required repeat surgery, which was performed for postoperative brisk bleeding in three. Eventually, ten patients experienced partial flap loss and nine experienced complete flap loss, with the latter requiring subsequent pectoralis major flap reconstruction. Microvascular free flap reconstruction represents an essential and reliable technique for head and neck defects and allows surgeons to perform radical resection with satisfactory functional results and acceptable complication rates.

  1. Significance of water quality to fish propagation, waterfowl habitat, livestock watering, and recreation use for 24 lakes and reservoirs in Valley and Phillips Counties, Montana

    USGS Publications Warehouse

    Ferreira, R.F.

    1983-01-01

    Twenty-four reservoirs were sampled for water quality to determine their suitability for fish propagation, waterfowl habitat, livestock watering, and recreation. Reservoir-surface areas ranged from 0.2 to 146 hectares and depths ranged from 0.01 to 6.0 meters. Of the reservoirs studied, six generally had water quality that would not be detrimental to fish propagation. Most of the reservoirs were enriched with nutrients and supported large concentrations of phytoplankton and dense growth of aquatic plants. In late winter and late summer, enrichment of shallow reservoirs often resulted in dissolved-oxygen concentrations less than 5.0 milligrams per liter, which is detrimental to fish. Three reservoirs lacked aquatic plants for water fowl habitat. Four reservoirs had small dissolved-oxygen concentration in the bottom water that might be critical to the protection of waterfowl if botulism were to occur. Specific conductance of water samples from three reservoirs was sufficiently close to the criterion of 4,800 microsiemens per centimeter at 25 degrees celsius to be regarded as potentially hazardous to livestock. However, most of the reservoirs generally would not be conducive to recreational swimming. Visibility was limited in most of the reservoirs. In addition, leech populations and growth of submersed aquatic plants in most of the reservoirs would be a nuisance to swimmers. (USGS)

  2. An optically stabilized fast-switching light emitting diode as a light source for functional neuroimaging.

    PubMed

    Wagenaar, Daniel A

    2012-01-01

    Neuroscience research increasingly relies on optical methods for evoking neuronal activity as well as for measuring it, making bright and stable light sources critical building blocks of modern experimental setups. This paper presents a method to control the brightness of a high-power light emitting diode (LED) light source to an unprecedented level of stability. By continuously monitoring the actual light output of the LED with a photodiode and feeding the result back to the LED's driver by way of a proportional-integral controller, drift was reduced to as little as 0.007% per hour over a 12-h period, and short-term fluctuations to 0.005% root-mean-square over 10 seconds. The LED can be switched on and off completely within 100 μs, a feature that is crucial when visual stimuli and light for optical recording need to be interleaved to obtain artifact-free recordings. The utility of the system is demonstrated by recording visual responses in the central nervous system of the medicinal leech Hirudo verbana using voltage-sensitive dyes.

  3. Platelet aggregation Inhibitors from Hametophagous Animals

    PubMed Central

    Francischetti, Ivo M. B.

    2010-01-01

    Salivary glands from blood-sucking animals (e.g., mosquitoes, bugs, sandflies, fleas, ticks, leeches, hookworms, bats) are a rich source of bioactive molecules that counteract hemostasis in a redundant and synergistic manner. This review discusses recent progress in the identification of salivary inhibitors of platelet aggregation, their molecular characterization, and detailed mechanism of action. Diversity of inhibitors is remarkable, with distinct families of proteins characterized as apyrases that enzymatically degrade ADP or as collagen-binding proteins that prevent its interaction with vWF, or platelet integrin α2β1 or GPVI. Molecules that bind ADP, TXA2, epinephrine, or serotonin with high affinity have also been cloned, expressed, and their structure determined. In addition, a repertoire of antithrombins and an increasingly number of RGD and non-RGD disintegrins targeting platelet αIIbβ3 have been reported. Moreover, metalloproteases with fibrinogen(olytic) activity and PAF phosphorylcholine hydrolase are enzymes that have been recruited to the salivary gland to block platelet aggregation. Platelet inhibitory prostaglandins, lysophosphatydilcholine, adenosine, and nitric oxide (NO)-carrying proteins are other notable examples of molecules from hematophagous salivary secretions (herein named sialogenins) with antihemostatic properties. Sialogenins have been employed as tools in biochemistry and cell biology and also display potential therapeutic applications. PMID:20035779

  4. Interactions of neurons with topographic nano cues affect branching morphology mimicking neuron-neuron interactions.

    PubMed

    Baranes, Koby; Kollmar, Davida; Chejanovsky, Nathan; Sharoni, Amos; Shefi, Orit

    2012-08-01

    We study the effect of topographic nano-cues on neuronal growth-morphology using invertebrate neurons in culture. We use photolithography to fabricate substrates with repeatable line-pattern ridges of nano-scale heights of 10-150 nm. We plate leech neurons atop the patterned-substrates and compare their growth pattern to neurons plated atop non-patterned substrates. The model system allows us the analysis of single neurite-single ridge interactions. The use of high resolution electron microscopy reveals small filopodia processes that attach to the line-pattern ridges. These fine processes, that cannot be detected in light microscopy, add anchoring sites onto the side of the ridges, thus additional physical support. These interactions of the neuronal process dominantly affect the neuronal growth direction. We analyze the response of the entire neuronal branching tree to the patterned substrates and find significant effect on the growth patterns compared to non-patterned substrates. Moreover, interactions with the nano-cues trigger a growth strategy similarly to interactions with other neuronal cells, as reflected in their morphometric parameters. The number of branches and the number of neurites originating from the soma decrease following the interaction demonstrating a tendency to a more simplified neuronal branching tree. The effect of the nano-cues on the neuronal function deserves further investigation and will strengthen our understanding of the interplay between function and form.

  5. Persistence of Clostridium botulinum type C toxin in blow fly (Calliphoridae) larvae as a possible cause of avian botulism in spring.

    PubMed

    Hubálek, Z; Halouzka, J

    1991-01-01

    Diverse samples were examined at a site of water-bird mortality, caused by Clostridium botulinum type C toxin in southern Moravia (Czechoslovakia). The toxin was detected in high concentrations in mute swan (Cygnus olor) carcasses (less than or equal to 1 x 10(6) LD50/g) as well as in necrophagous larvae and pupae of the blow flies Lucilia sericata and Calliphora vomitoria (less than or equal to 1 x 10(5) LD50/g) collected from them. It was detected in lower concentrations (less than or equal to 1 x 10(3) LD50/g) in other invertebrates (ptychopterid fly larvae, leeches, sow-bugs) associated with these carcasses, and occasionally in water samples (8 LD50/ml) close to the carrion. The toxin was not detected in the samples of water, mud or invertebrates collected at a distance greater than or equal to 5 m from the carcasses. The toxin-bearing larvae of L. sericata and C. vomitoria, containing 80,000 LD50/g of type C toxin, were exposed in the mud at the study site for 131 days from November to March. Although the toxin activity decreased 25-fold and 40-fold in the two samples of maggots exposed during this period, it remained very high (less than or equal to 3,200 LD50/g). Birds ingesting a relatively low number of these toxic larvae (or pupae) in the spring could receive a lethal dose of the toxin.

  6. Regeneration and asexual reproduction share common molecular changes: upregulation of a neural glycoepitope during morphallaxis in Lumbriculus.

    PubMed

    Martinez, Veronica G; Menger, Gus J; Zoran, Mark J

    2005-05-01

    Neural morphallaxis is a regenerative process characterized by wide-spread anatomical and physiological changes in an adult nervous system. During segmental regeneration of the annelid worm, Lumbriculus variegatus, neural morphallaxis involved a reorganization of sensory, interneuronal, and motor systems as posterior fragments gained a more anterior body position. A monoclonal antibody, Lan 3-2, which labels a neural glyco-domain in the leech, was reactive in Lumbriculus. In the worm, this antibody labeled neural structures, particularly axonal tracts and giant fiber pathways of the central nervous system. A 60kDa protein, possessing a lumbriculid mannose-rich glycoepitope, was upregulated during neural morphallaxis, peaking in its expression at 3 weeks post-amputation. Peak upregulation of the Lan 3-2 epitope, or the protein possessing it, corresponded to the time of major neurobehavioral plasticity during regeneration. Analyses of asexually reproducing animals also revealed induction of the Lan 3-2 epitope. In this developmental context, Lan 3-2 epitope upregulation was also confined to segments expressing both changes in positional identity and neurobehavioral plasticity, but these molecular and behavioral changes occurred prior to body fragmentation. These results suggest that the lumbriculid Lan 3-2 glycoepitope and proteins that bear them have been co-opted for neural morphallactic programs, induced both in anticipation of reproductive fragmentation and in compensation for injury-induced fragmentation.

  7. Fingertip replantation at or distal to the nail base: use of the technique of artery-only anastomosis.

    PubMed

    Akyürek, M; Safak, T; Keçik, A

    2001-06-01

    The authors describe the functional and aesthetic results of microsurgical replantation of 21 fingertip amputations at or distal to the nail base-namely, zone I amputations. There were 15 male and 6 female patients, with an average age of 26 years (age range, 1-41 years). Replantations were performed using the anastomosis of the artery-only technique, with neither vein nor nerve repair. Venous drainage was provided by an external bleeding method with a fish-mouth incision in "distal" zone I amputations for approximately 7 days, and by the use of leeches in more "proximal" zone I amputations for 10 to 12 days. Results indicated that the overall survival rate was 76%, with 16 of 21 digits surviving. Sensory evaluation at an average follow-up of 12 months (range, 6-18 months) revealed an average static two-point discrimination of 6.1 mm (range, 2.0-8.0 mm). Considering the unfavorable results and the donor site morbidity of various fingertip reconstructions, a microsurgical fingertip replantation should always be considered except in extremely distal, clean-cut, pediatric cases, in which case a composite graft is a possibility. The results of this series indicate that an amputated fingertip in zone I can be salvaged successfully by microvascular anastomosis of the artery only, with a nonmicrosurgical method of venous drainage. Furthermore, acceptable sensory recovery can be expected without any nerve coaptation.

  8. The toxicogenomic multiverse: convergent recruitment of proteins into animal venoms.

    PubMed

    Fry, Bryan G; Roelants, Kim; Champagne, Donald E; Scheib, Holger; Tyndall, Joel D A; King, Glenn F; Nevalainen, Timo J; Norman, Janette A; Lewis, Richard J; Norton, Raymond S; Renjifo, Camila; de la Vega, Ricardo C Rodríguez

    2009-01-01

    Throughout evolution, numerous proteins have been convergently recruited into the venoms of various animals, including centipedes, cephalopods, cone snails, fish, insects (several independent venom systems), platypus, scorpions, shrews, spiders, toxicoferan reptiles (lizards and snakes), and sea anemones. The protein scaffolds utilized convergently have included AVIT/colipase/prokineticin, CAP, chitinase, cystatin, defensins, hyaluronidase, Kunitz, lectin, lipocalin, natriuretic peptide, peptidase S1, phospholipase A(2), sphingomyelinase D, and SPRY. Many of these same venom protein types have also been convergently recruited for use in the hematophagous gland secretions of invertebrates (e.g., fleas, leeches, kissing bugs, mosquitoes, and ticks) and vertebrates (e.g., vampire bats). Here, we discuss a number of overarching structural, functional, and evolutionary generalities of the protein families from which these toxins have been frequently recruited and propose a revised and expanded working definition for venom. Given the large number of striking similarities between the protein compositions of conventional venoms and hematophagous secretions, we argue that the latter should also fall under the same definition.

  9. Drivers of symbiont diversity in freshwater snails: a comparative analysis of resource availability, community heterogeneity, and colonization opportunities.

    PubMed

    McCaffrey, Keegan; Johnson, Pieter T J

    2017-04-01

    Decades of community ecology research have highlighted the importance of resource availability, habitat heterogeneity, and colonization opportunities in driving biodiversity. Less clear, however, is whether a similar suite of factors explains the diversity of symbionts. Here, we used a hierarchical dataset involving 12,712 freshwater snail hosts representing five species to test the relative importance of potential factors in driving symbiont richness. Specifically, we used model selection to assess the explanatory power of variables related to host species identity, resource availability (average body size, host density), ecological heterogeneity (richness of hosts and other taxa), and colonization opportunities (wetland size and amount of neighboring wetland area) on symbiont richness in 146 snail host populations in California, USA. We encountered a total of 23 taxa of symbionts, including both obligatory parasites such as digenetic trematodes as well as more commensal, mutualistic, or opportunistic groups such as aquatic insect larvae, annelids, and leeches. After validating richness estimates per host population using species accumulative curves, we detected positive effects on symbiont richness from host body size, total richness of the aquatic community, and colonization opportunities. Neither snail density nor the richness of snail species accounted for significant variation in symbiont diversity. Host species identity also affected symbiont richness, with higher gamma and average alpha diversity among more common host species with higher local abundances. These findings highlight the importance of multiple, concurrent factors in driving symbiont richness that extend beyond epidemiological measures of host abundance or host diversity alone.

  10. Biomagnification of polychlorinated biphenyls through a riverine food web

    SciTech Connect

    Zaranko, D.T.; Kaushik, N.K.; Griffiths, R.W.

    1997-07-01

    From 1989 to 1993, biota collected from Pottersburg Creek, London, ON, Canada were analyzed for total polychlorinated biphenyls (PCBs) and lipids. Data were analyzed by analysis of covariance (ANCOVA) with lipid as the covariate, to investigate station, time, and trophic effects on PCB accumulation in aquatic organisms. All three variables were highly significant. PCB concentrations in biota decreased along the length of the creek away from the point source. PCB concentrations in biota collected in July 1993 were not significantly different from concentrations in biota collected in July 1990, suggesting that sources into the creek have not been alleviated. The relationship between PCBs and lipid for biota from Pottersburg Creek suggests that organisms accumulate PCBs relative to their position in the food web. Fish and leeches occupying the top of the food web accumulated more PCBs than organisms occupying a lower trophic position (crayfish and oligochaetes/chironomids), indicating that biomagnification through trophic transfer (i.e., the uptake of a chemical through ingestion) is the primary mechanism governing contaminant levels in biota and not bioconcentration (i.e, the uptake of a chemical from water).

  11. Evolutionary Dynamics of the wnt Gene Family: A Lophotrochozoan Perspective

    PubMed Central

    Cho, Sung-Jin; Vallès, Yvonne; Giani, Vincent C.; Seaver, Elaine C.; Weisblat, David A.

    2010-01-01

    expression analyses. The 36 wnt genes obtained represent 11, 12, and 9 distinct wnt subfamilies in Lottia, Capitella, and Helobdella, respectively. Thus, two of the three analyzed lophotrochozoan genomes retained an almost complete ancestral complement of wnt genes emphasizing the importance and complexity of this gene family across metazoans. The genome of the leech Helobdella reflects significantly more dynamism than those of Lottia and Capitella, as judged by gene duplications and losses, branch length, and changes in genetic linkage. Finally, we performed a detailed expression analysis for all the Helobdella wnt genes during embryonic development. We find that, although the patterns show substantial overlap during early cleavage stages, each wnt gene has a unique expression pattern in the germinal plate and during tissue morphogenesis. Comparisons of the embryonic expression patterns of the duplicated wnt genes in Helobdella with their orthologs in Capitella reveal extensive regulatory diversification of the duplicated leech wnt genes. PMID:20176615

  12. Erythropoietin promotes survival and regeneration of insect neurons in vivo and in vitro.

    PubMed

    Ostrowski, D; Ehrenreich, H; Heinrich, R

    2011-08-11

    In addition to its function as a regulator of hematopoiesis, the cytokine erythropoietin (Epo) initiates adaptive cellular responses to both moderate environmental challenges and tissue damaging insults in various non-hematopoietic mammalian tissues. Epo's neuroprotective and neuroregenerative functions mediated through janus kinases (JAK)/signal transducers and activators of transcription (STAT) transduction pathways and regulation of Epo and Epo receptor expression in the nervous system by hypoxia inducible factor (HIF) have been documented in a variety of in vitro and in vivo studies and homologs of the human Epo gene are present in fish, amphibians and mammals. The present study reproduces the hallmarks of Epo-mediated mammalian neuroprotection in the grasshopper nervous system. Recombinant human Epo (rhEpo) increases the survival of dissociated grasshopper brain neurons under normoxic and hypoxic conditions and promotes the regeneration of neurites in vitro. In addition, reestablishment of sound source localization after unilateral tympanic nerve crush injury was accelerated and more complete after application of rhEpo, demonstrating in vivo support of auditory receptor cell axon regeneration. Immunoblots of central nervous tissue extracts from mouse, grasshopper, crayfish and leech labeled protein bands of ∼38 kDa, fitting to the molecular weight of Epo reported in earlier studies. These results indicate that a ligand/receptor system that shares structural and functional similarities with mammalian Epo and Epo receptor exerts neuroprotective and neuroregenerative effects in insects. With both upstream (HIF system) and downstream (JAK/STAT pathway) elements of the mammalian Epo system being present in insects and other invertebrates, Epo-like signaling involved in tissue protection appears to be an ancient beneficial function shared by vertebrates and invertebrates.

  13. The evolution of filamin – A protein domain repeat perspective

    PubMed Central

    Light, Sara; Sagit, Rauan; Ithychanda, Sujay S.; Qin, Jun; Elofsson, Arne

    2013-01-01

    Particularly in higher eukaryotes, some protein domains are found in tandem repeats, performing broad functions often related to cellular organization. For instance, the eukaryotic protein filamin interacts with many proteins and is crucial for the cytoskeleton. The functional properties of long repeat domains are governed by the specific properties of each individual domain as well as by the repeat copy number. To provide better understanding of the evolutionary and functional history of repeating domains, we investigated the mode of evolution of the filamin domain in some detail. Among the domains that are common in long repeat proteins, sushi and spectrin domains evolve primarily through cassette tandem duplications while scavenger and immunoglobulin repeats appear to evolve through clustered tandem duplications. Additionally, immunoglobulin and filamin repeats exhibit a unique pattern where every other domain shows high sequence similarity. This pattern may be the result of tandem duplications, serve to avert aggregation between adjacent domains or it is the result of functional constraints. In filamin, our studies confirm the presence of interspersed integrin binding domains in vertebrates, while invertebrates exhibit more varied patterns, including more clustered integrin binding domains. The most notable case is leech filamin, which contains a 20 repeat expansion and exhibits unique dimerization topology. Clearly, invertebrate filamins are varied and contain examples of similar adjacent integrin-binding domains. Given that invertebrate integrin shows more similarity to the weaker filamin binder, integrin β3, it is possible that the distance between integrin-binding domains is not as crucial for invertebrate filamins as for vertebrates. PMID:22414427

  14. Factors Influencing the Stable Oxygen and Hydrogen Isotopic Composition (δ 18O and δ D) of a Subarctic Freshwater Lake Ecosystem

    NASA Astrophysics Data System (ADS)

    Wang, Y.; Wooller, M. J.

    2005-12-01

    Previous studies have shown that the stable oxygen and hydrogen isotopic compositions (δ 18O and δD) in various animal tissues can be used to examine past climates and animal migration pattern. Little attention has been paid to the relative roles of diet and water influencing the overall δ 18O and δD of animal tissues in freshwater ecosystems. It is unclear whether different trophic levels in a freshwater lake ecosystem have an identical relationship to the water that surrounds them. The δ18O and δD values of animal tissues may be controlled by numerous different factors, including metabolic and biosynthetic isotopic fractionation and variations of δ 18O and δD in the food available. We began to examine these issues by analyzing the δ 18O and δD throughout a freshwater aquatic ecosystem at Smith Lake in Alaska. We collected samples representing primary producers and consumers (primary and secondary). Samples included green algae, various aquatic plants, such as Nuphar variegatum (water lily), Polygonum amphibium (water smartweed), Carex utriculata (sedge), Utricularia vulgaris (common bladderwort), Typha latifolia (common cattail), and a range of aquatic invertebrates, including Chironomus. sp (midge), Zygoptera (damselfly), Anisoptera (dragonfly), Dytiscidae (diving beetle) and Euhirudinea (leeches). The δ 18O and δD of Smith Lake water were ~-13.5e and -129.0e, respectively, and we present the δ 18O and δD of the rest of the ecosystem relative to these data. For instance, the δ 18O of chironomus sp. was ~12.1, which is greater than the of the lake water. Preliminary results suggest the extent of the fractionation between δ 18O of chironomids vs. lake water δ 18O is consistent with previous studies. Our data provide an insight into the range of variations that could be expected within a single freshwater ecosystem.

  15. Fate of nitrogen deposition and decomposed nitrogen from litter in a 15N-tracer mesocosm experiment

    NASA Astrophysics Data System (ADS)

    Nair, R.; Perks, M.; Mencuccini, M.

    2013-12-01

    Atmospheric deposition of anthropogenic-derived nitrogen may be a major driver of the 0.6-0.7 Pg y-1 increase in the carbon sink in historically N-limited northern and boreal forests, but the magnitude of its effect is still uncertain. A strong effect depends on the allocation of N to trees, because of their high C:N ratio in woody tissues, and isotope tracer experiments have shown that the majority of 15N tracers applied directly to the soil are lost via leeching or retained in soil pools rather than being acquired by tree root systems. However, ambient anthropogenic inputs of N to these systems are transported in the atmosphere and intercepted by foliage before they reach the soil system, while labelled fertilization experiments also can only explicitly trace the fate of the 15N-tracer from deposition, as opposed to changes in the fate of N from litter, where decomposition rates may be enhanced at low ambient levels of deposition, affecting the availability of N from this pool for tree nutrition. We present initial results from a potted Sitka Spruce mesocosm 15N-tracer experiment where ambient nitrogen deposition was supplemented with a minor (0.4 kg ha-1 y-1) input of additional N, applied to either the soil or the foliage. Either this deposition, or litter in the pots, was enriched in 15N, allowing the fate of the isotope from two different methods of deposition to be compared with that of nitrogen released from the litter under the deposition treatment.

  16. Acidification of experimental wetlands: Effects on wetland productivity and survival of juvenile black ducks

    USGS Publications Warehouse

    Haramis, G.M.; Chu, D.S.; Bunck, C.M.; Mingo, T.M.; Schaffner, W.W.R.

    1997-01-01

    Six man-made wetlands (0.02 ha each) and pen-reared broods of American black ducks (Anas rubripes) were used to assess the effects of reduced pH on the quality of fish- free, palustrine habitat for brood rearing. Acid treatment was assigned randomly among newly constructed wetlands during April through June 1984-85, to simulate depressed pH from snowmelt and spring rain. Sampling of chlorophyll epiphytic growth, zooplankton and macroinvertebrates confirmed reduced productivity of acidified (pH 5.0) versus control (pH 6.8) wetlands. Primary productivity was particularly reduced in acidified wetlands in early spring as indicated by high water transparency and low chlorophyll a concentrations. Chlrophyll a concentrations showed treatment (p = 0.01) and date (p = 0.05) effects, but no interaction, and dry weight of epiphytic growth was lower (p = 0.03) in acidified versus control wetlands. Numbers of zooplankton were similar in experimental wetlands, although controls generally exceeded acidified wetlands in abundance; only a single treatment effect for cladocerans (p = 0.1) was detected. Sweep net samples yielded greater numbers (p = 0.03), taxa (p = 0.01) and biomass (p = 0.07) of macroinvertebrates in control wetlands with gastropods, pelecypods and leeches notably reduced by acidification. Placement of 18 broods (female with four 10-day-old ducklings) for 10-day trials on experimental wetlands revealed limited growth, altered behaviour and marked reduction in survival of ducklings on acidified wetlands. An inadequate number of invertebrates is indicated as the cause for poor duckling productivity on acidified wetlands

  17. CNQX and AMPA inhibit electrical synaptic transmission: a potential interaction between electrical and glutamatergic synapses

    PubMed Central

    Li, Qin; Burrell, Brian D.

    2008-01-01

    Electrical synapses play an important role in signaling between neurons and the synaptic connections between many neurons possess both electrical and chemical components. Although modulation of electrical synapses is frequently observed, the cellular processes that mediate such changes have not been studied as thoroughly as plasticity in chemical synapses. In the leech (Hirudo sp), the competitive AMPA receptor antagonist CNQX inhibited transmission at the rectifying electrical synapse of a mixed glutamatergic/electrical synaptic connection. This CNQX-mediated inhibition of the electrical synapse was blocked by concanavalin A (Con A) and dynamin inhibitory peptide (DIP), both of which are known to inhibit endocytosis of neurotransmitter receptors. CNQX-mediated inhibition was also blocked by pep2-SVKI (SVKI), a synthetic peptide that prevents internalization of AMPA-type glutamate receptor. AMPA itself also inhibited electrical synaptic transmission and this AMPA-mediated inhibition was partially blocked by Con A, DIP and SVKI. Low frequency stimulation induced long-term depression (LTD) in both the electrical and chemical components of these synapses and this LTD was blocked by SVKI. GYKI 52466, a selective non-competitive antagonist of AMPA receptors, did not affect the electrical EPSP, although it did block the chemical component of these synapses. CNQX did not affect non-rectifying electrical synapses in two different pairs of neurons. These results suggest an interaction between AMPA-type glutamate receptors and the gap junction proteins that mediate electrical synaptic transmission. This putative interaction between glutamate receptors and gap junction proteins represents a novel mechanism for regulating the strength of synaptic transmission. PMID:18601913

  18. Potential Reservoirs and Risk Factors for VHSV IVb in an Enzootic System: Budd Lake, Michigan.

    PubMed

    Throckmorton, Elizabeth; Brenden, Travis; Peters, Amber K; Newcomb, Tammy J; Whelan, Gary E; Faisal, Mohamed

    2017-03-01

    Viral hemorrhagic septicemia virus genotype IVb (VHSV IVb) has caused major, sporadic fish die-offs in the Laurentian Great Lakes region of North America since 2005. Presently, factors affecting VHSV IVb persistence in enzootic systems are not well understood. Even with annual surveillance, the virus can go undetected for several years after an outbreak before again re-emerging, which suggests that the virus is maintained in the system either below detectable levels or in untested reservoirs. The aim of this study was to identify potential reservoirs of VHSV IVb in Budd Lake, Michigan; VHSV IVb was first detected in Budd Lake in 2007 but remained undetected until 2011. Additionally, we explored the susceptibility of naive fish introduced into a water body enzootic for VHSV IVb by stocking age-0 Largemouth Bass Micropterus salmoides at varying densities into enclosures in the lake. The virus was not detected among samples of the fishes Notropis spp. and Lepomis spp., cylindrical papershell mussels Anodontoides ferussacianus, leeches (subclass Hirudinea), sediment, or water. However, the virus was successfully isolated from amphipods (family Hyalellidae) and Largemouth Bass held in the enclosures. Our finding of VHSV IVb in Hyalellidae amphipods in combination with other research that has detected the virus in Diporeia spp., a large benthic amphipod important as a food resource to Great Lake fishes, suggests that benthic macroinvertebrates are a reservoir for VHSV IVb in infected systems. If there are environmental reservoirs for VHSV IVb in infected systems, they are likely unevenly distributed. Findings of this study add to our understanding of the seemingly complex ecology of this deadly and economically detrimental virus. Received February 22, 2016; accepted October 16, 2016.

  19. Bioaccumulation of radionuclides in fertilized Canadian Shield lake basins.

    PubMed

    Bird, G A; Hesslein, R H; Mills, K H; Schwartz, W J; Turner, M A

    1998-07-11

    Radionuclide tracers of heavy metals (59Fe, 60Co, 65Zn, 75Se, 85Sr, 134Cs and 203Hg) representing potential contamination from nuclear power plants, industry and agriculture were added to separate basins of Lake 226, Experimental Lakes Area, northwestern Ontario. The two basins were part of a eutrophication experiment and differed in their trophic status; the north basin (L226N) was eutrophic whereas the south basin (L226S) was mesotrophic. Our objective was to determine the uptake of the radionuclides by biota and the effect of lake trophic status on their bioaccumulation. The trophic status of the lakes did not appear to have a marked effect on the accumulation of radionuclides by the biota. This may have been because of a mid-summer leakage of nutrients between the basins which enhanced primary production in L226S, because there is a time lag between primary production and the availability of the radionuclides to the fishes or because trophic status does not affect the uptake of at least some of these radionuclides. However, there was a tendency for faster uptake of the radionuclides in L226N by fish than L226S, but the differences were not significant. Concentrations in the biota generally decreased in the order: fathead minnow > pearl dace > tadpoles > slimy sculpin > leeches. Concentrations in biota generally decreased in the order. 65Zn > 203Hg > 75Se > 134Cs > 60Co > 85Sr = 59Fe. Cobalt-60 concentrations in tadpoles were greater than in the other biota. Radionuclide concentrations in the tissues of lake whitefish indicated that uptake was predominantly from food. Radionuclide concentrations were usually higher in the posterior gut, liver and kidney than in other tissues, whereas body burdens were generally high in the muscle for 75Se, 134Cs and 203Hg; kidney and gut for 60Co; and bone for 65Zn and 75Se. Mercury-203 burdens were also high in the bone and gut.

  20. Exocytosis of serotonin from the neuronal soma is sustained by a serotonin and calcium-dependent feedback loop

    PubMed Central

    Leon-Pinzon, Carolina; Cercós, Montserrat G.; Noguez, Paula; Trueta, Citlali; De-Miguel, Francisco F.

    2014-01-01

    The soma of many neurons releases large amounts of transmitter molecules through an exocytosis process that continues for hundreds of seconds after the end of the triggering stimulus. Transmitters released in this way modulate the activity of neurons, glia and blood vessels over vast volumes of the nervous system. Here we studied how somatic exocytosis is maintained for such long periods in the absence of electrical stimulation and transmembrane Ca2+ entry. Somatic exocytosis of serotonin from dense core vesicles could be triggered by a train of 10 action potentials at 20 Hz in Retzius neurons of the leech. However, the same number of action potentials produced at 1 Hz failed to evoke any exocytosis. The 20-Hz train evoked exocytosis through a sequence of intracellular Ca2+ transients, with each transient having a different origin, timing and intracellular distribution. Upon electrical stimulation, transmembrane Ca2+ entry through L-type channels activated Ca2+-induced Ca2+ release. A resulting fast Ca2+ transient evoked an early exocytosis of serotonin from sparse vesicles resting close to the plasma membrane. This Ca2+ transient also triggered the transport of distant clusters of vesicles toward the plasma membrane. Upon exocytosis, the released serotonin activated autoreceptors coupled to phospholipase C, which in turn produced an intracellular Ca2+ increase in the submembrane shell. This localized Ca2+ increase evoked new exocytosis as the vesicles in the clusters arrived gradually at the plasma membrane. In this way, the extracellular serotonin elevated the intracellular Ca2+ and this Ca2+ evoked more exocytosis. The resulting positive feedback loop maintained exocytosis for the following hundreds of seconds until the last vesicles in the clusters fused. Since somatic exocytosis displays similar kinetics in neurons releasing different types of transmitters, the data presented here contributes to understand the cellular basis of paracrine neurotransmission

  1. Parasites of native and nonnative fishes of the Little Colorado River, Grand Canyon, Arizona.

    PubMed

    Choudhury, Anindo; Hoffnagle, Timothy L; Cole, Rebecca A

    2004-10-01

    A 2-yr, seasonal, parasitological study of 1,435 fish, belonging to 4 species of native fishes and 7 species of nonnative fishes from the lower Little Colorado River (LCR) and tributary creeks, Grand Canyon, Arizona, yielded 17 species of parasites. These comprised 1 myxozoan (Henneguya exilis), 2 copepods (Ergasilus arthrosis and Lernaea cyprinacea), 1 acarine (Oribatida gen. sp.), 1 piscicolid leech (Myzobdella lugubris), 4 monogeneans (Gyrodactylus hoffmani, Gyrodactylus sp., Dactylogyrus extensus, and Ligictaluridus floridanus), 4 nematodes (Contracaecum sp., Eustrongylides sp., Rhabdochona sp., and Truttaedacnitis truttae), 3 cestodes (Bothriocephalus acheilognathi, Corallobothrium fimbriatum, and Megathylacoides giganteum), and 2 trematodes (Ornithodiplostomum sp. and Posthodiplostomum sp.). Rhabdochona sp. was the only adult parasite native to the LCR. Infection intensities of Ornithodiplostomum sp. and B. acheilognathi were positively correlated with length of the humpback chub Gila cypha. Adult helminths showed a high degree of host specificity, except B. acheilognathi, which was recovered from all fish species examined but was most abundant in cyprinids. Abundance of B. acheilognathi in the humpback chub was highest in the fall and lowest in the summer in both reaches of the LCR. There was no major taxonomic difference in parasite assemblages between the 2 different reaches of the river (LC1 and LC2). Parasite community diversity was very similar in humpback chub, regardless of sampling site or time. The parasite fauna of the LCR is numerically dominated by B. acheilognathi and metacercariae of Ornithodiplostomum sp. The richest and most diverse component community occurred in a nonnative species, the channel catfish Ictalurus punctatus, but infracommunity species richness was highest in a native host, humpback chub.

  2. Neuronal Competition for Action Potential Initiation Sites in a Circuit Controlling Simple Learning

    PubMed Central

    Cruz, Georgina E.; Sahley, Christie L.; Muller, Kenneth J.

    2007-01-01

    The spatial and temporal patterns of action potential initiations were studied in a behaving leech preparation to determine the basis of increased firing that accompanies sensitization, a form of non-associative learning requiring the S-interneurons. Little is known at the network level about mechanisms of behavioral sensitization. The S-interneurons, one in each ganglion and linked by electrical synapses with both neighbors to form a chain, are interposed between sensory and motor neurons. In sensitized preparations the strength of shortening is related to S-cell firing, which itself is the result of impulses initiating in several S-cells. Because the S-cells, as independent initiation sites, all contribute to activity in the chain, it was hypothesized that during sensitization, increased multi-site activity increased the chain's firing rate. However, it was found that during sensitization, the single site with the largest initiation rate, the S-cell in the stimulated segment, suppressed initiations in adjacent ganglia. Experiments showed this was both because (1) it received the earliest, greatest input and (2) the delayed synaptic input to the adjacent S-cells coincided with the action potential refractory period. A compartmental model of the S-cell and its inputs showed that a simple, intrinsic mechanism of inexcitability after each action potential may account for suppression of impulse initiations. Thus, a non-synaptic competition between neurons alters synaptic integration in the chain. In one mode, inputs to different sites sum independently, whereas in another, synaptic input to a single site precisely specifies the overall pattern of activity. PMID:17644266

  3. Analysis of Family Structures Reveals Robustness or Sensitivity of Bursting Activity to Parameter Variations in a Half-Center Oscillator (HCO) Model

    PubMed Central

    2016-01-01

    The underlying mechanisms that support robustness in neuronal networks are as yet unknown. However, recent studies provide evidence that neuronal networks are robust to natural variations, modulation, and environmental perturbations of parameters, such as maximal conductances of intrinsic membrane and synaptic currents. Here we sought a method for assessing robustness, which might easily be applied to large brute-force databases of model instances. Starting with groups of instances with appropriate activity (e.g., tonic spiking), our method classifies instances into much smaller subgroups, called families, in which all members vary only by the one parameter that defines the family. By analyzing the structures of families, we developed measures of robustness for activity type. Then, we applied these measures to our previously developed model database, HCO-db, of a two-neuron half-center oscillator (HCO), a neuronal microcircuit from the leech heartbeat central pattern generator where the appropriate activity type is alternating bursting. In HCO-db, the maximal conductances of five intrinsic and two synaptic currents were varied over eight values (leak reversal potential also varied, five values). We focused on how variations of particular conductance parameters maintain normal alternating bursting activity while still allowing for functional modulation of period and spike frequency. We explored the trade-off between robustness of activity type and desirable change in activity characteristics when intrinsic conductances are altered and identified the hyperpolarization-activated (h) current as an ideal target for modulation. We also identified ensembles of model instances that closely approximate physiological activity and can be used in future modeling studies. PMID:27595135

  4. Muscle organizers in Drosophila: the role of persistent larval fibers in adult flight muscle development

    NASA Technical Reports Server (NTRS)

    Farrell, E. R.; Fernandes, J.; Keshishian, H.

    1996-01-01

    In many organisms muscle formation depends on specialized cells that prefigure the pattern of the musculature and serve as templates for myoblast organization and fusion. These include muscle pioneers in insects and muscle organizing cells in leech. In Drosophila, muscle founder cells have been proposed to play a similar role in organizing larval muscle development during embryogenesis. During metamorphosis in Drosophila, following histolysis of most of the larval musculature, there is a second round of myogenesis that gives rise to the adult muscles. It is not known whether muscle founder cells organize the development of these muscles. However, in the thorax specific larval muscle fibers do not histolyze at the onset of metamorphosis, but instead serve as templates for the formation of a subset of adult muscles, the dorsal longitudinal flight muscles (DLMs). Because these persistent larval muscle fibers appear to be functioning in many respects like muscle founder cells, we investigated whether they were necessary for DLM development by using a microbeam laser to ablate them singly and in combination. We found that, in the absence of the larval muscle fibers, DLMs nonetheless develop. Our results show that the persistent larval muscle fibers are not required to initiate myoblast fusion, to determine DLM identity, to locate the DLMs in the thorax, or to specify the total DLM fiber volume. However, they are required to regulate the number of DLM fibers generated. Thus, while the persistent larval muscle fibers are not obligatory for DLM fiber formation and differentiation, they are necessary to ensure the development of the correct number of fibers.

  5. Procarboxypeptidase A from the insect pest Helicoverpa armigera and its derived enzyme. Two forms with new functional properties.

    PubMed

    Bayés, Alex; Sonnenschein, Anka; Daura, Xavier; Vendrell, Josep; Aviles, Francesc X

    2003-07-01

    Although there is a significant knowledge about mammalian metallocarboxypeptidases, the data available on this family of enzymes is very poor for invertebrate forms. Here we present the biochemical characterization of a metallocarboxypeptidase from the insect Helicoverpa armigera (Lepidoptera: Noctuidae), a devastating pest spread in subtropical regions of Europe, Asia, Africa and Oceania. The zymogen of this carboxypeptidase (PCPAHa) has been expressed at high levels in a Pichia pastoris system and shown to display the characteristics of the enzyme purified from the insect midgut. The in vitro activation process of the proenzyme differs significantly from the mammalian ones. The lysine-specific endoprotease LysC activates PCPAHa four times more efficiently than trypsin, the general activating enzyme for all previously studied metalloprocarboxypeptidases. LysC and trypsin independently use two different activation targets and the presence of sugars in the vicinity of the LysC activation point affects the activation process, indicating a possible modulation of the activation mechanism. During the activation with LysC the prodomain is degraded, while the carboxypeptidase moiety remains intact except for a C-terminal octapeptide that is rapidly released. Interestingly, the sequence at the cleavage point for the release of the octapeptide is also found at the boundary between the activation peptide and the enzyme moieties. The active enzyme (CPAHa) is shown to have a very broad substrate specificity, as it appears to be the only known metallocarboxypeptidase capable of efficiently hydrolysing basic and aliphatic residues and, to a much lower extent, acidic residues. Two carboxypeptidase inhibitors, from potato and leech, were tested against CPAHa. The former, of vegetal origin, is the most efficient metallocarboxypeptidase inhibitor described so far, with a Ki in the pm range.

  6. Implications of the Organization to Assess Strategies for Ischemic Syndromes-2 (OASIS-2) study and the results in the context of other trials.

    PubMed

    Fox, K A

    1999-09-02

    Although unfractionated heparin is widely used for thrombin inhibition in the management of unstable coronary artery disease, clinical and experimental evidence suggests that it is suboptimal. Recent pharmaceutical strategies to improve upon unfractionated heparin's efficacy profile have centered on the development of 2 major classifications of thrombin inhibition medications: the naturally occurring leech protein hirudin (and synthetic analogs) and low-molecular-weight (LMW) heparins. In the Organisation to Assess Strategies for Ischaemic Syndromes-2 (OASIS-2) trial, hirudin was demonstrably more effective than heparin in diminishing rates of death, myocardial infarction (MI), and angina at both 72 hours and 7 days after unstable coronary artery disease index events, with risk ratios on the order of 0.8. Similarly, in the Efficacy and Safety of Subcutaneous Enoxaparin in Non-Q-Wave Coronary Events (ESSENCE) study, the LMW heparin enoxaparin emerged superior to unfractionated heparin in attenuating rates of unstable coronary artery disease at 14 days, 30 days, and 1 year. On the other hand, findings involving other LMW heparins (dalteparin sodium, Fragmin, and fraxaparin) are equivocal. Although the Fragmin During Instability in Coronary Artery Disease (FRISC) study demonstrated statistically significant superiority of this LMW heparin over aspirin/placebo in driving down death/MI/revascularization rates, the Fragmin in Unstable Coronary Artery Disease (FRIC) trial showed no such superiority, but had wide confidence intervals. Similarly, the Fraxaparin Versus Unfractionated Heparin in Acute Coronary Syndromes (FRAXIS) trial with fraxaparin failed to show superiority over unfractionated heparin. The favorable efficacy findings associated with hirudin and enoxaparin regimens, compared with unfractionated heparin, accrued without significant increases in the incidences of life-threatening bleeding events (e.g., hemorrhagic stroke), but did include more frequent lesser

  7. Analysis, Optimization and Verification of Illumina-Generated 16S rRNA Gene Amplicon Surveys

    PubMed Central

    Nelson, Michael C.; Morrison, Hilary G.; Benjamino, Jacquelynn; Grim, Sharon L.; Graf, Joerg

    2014-01-01

    The exploration of microbial communities by sequencing 16S rRNA genes has expanded with low-cost, high-throughput sequencing instruments. Illumina-based 16S rRNA gene sequencing has recently gained popularity over 454 pyrosequencing due to its lower costs, higher accuracy and greater throughput. Although recent reports suggest that Illumina and 454 pyrosequencing provide similar beta diversity measures, it remains to be demonstrated that pre-existing 454 pyrosequencing workflows can transfer directly from 454 to Illumina MiSeq sequencing by simply changing the sequencing adapters of the primers. In this study, we modified 454 pyrosequencing primers targeting the V4-V5 hyper-variable regions of the 16S rRNA gene to be compatible with Illumina sequencers. Microbial communities from cows, humans, leeches, mice, sewage, and termites and a mock community were analyzed by 454 and MiSeq sequencing of the V4-V5 region and MiSeq sequencing of the V4 region. Our analysis revealed that reference-based OTU clustering alone introduced biases compared to de novo clustering, preventing certain taxa from being observed in some samples. Based on this we devised and recommend an analysis pipeline that includes read merging, contaminant filtering, and reference-based clustering followed by de novo OTU clustering, which produces diversity measures consistent with de novo OTU clustering analysis. Low levels of dataset contamination with Illumina sequencing were discovered that could affect analyses that require highly sensitive approaches. While moving to Illumina-based sequencing platforms promises to provide deeper insights into the breadth and function of microbial diversity, our results show that care must be taken to ensure that sequencing and processing artifacts do not obscure true microbial diversity. PMID:24722003

  8. On the Basis of Synaptic Integration Constancy during Growth of a Neuronal Circuit

    PubMed Central

    De-La-Rosa Tovar, Adriana; Mishra, Prashant K.; De-Miguel, Francisco F.

    2016-01-01

    We studied how a neuronal circuit composed of two neuron types connected by chemical and electrical synapses maintains constant its integrative capacities as neurons grow. For this we combined electrophysiological experiments with mathematical modeling in pairs of electrically-coupled Retzius neurons from postnatal to adult leeches. The electrically-coupled dendrites of both Retzius neurons receive a common chemical input, which produces excitatory postsynaptic potentials (EPSPs) with varying amplitudes. Each EPSP spreads to the soma, but also crosses the electrical synapse to arrive at the soma of the coupled neuron. The leak of synaptic current across the electrical synapse reduces the amplitude of the EPSPs in proportion to the coupling ratio. In addition, summation of EPSPs generated in both neurons generates the baseline action potentials of these serotonergic neurons. To study how integration is adjusted as neurons grow, we first studied the characteristics of the chemical and electrical connections onto the coupled dendrites of neuron pairs with soma diameters ranging from 21 to 75 μm. Then by feeding a mathematical model with the neuronal voltage responses to pseudorandom noise currents we obtained the values of the coupling ratio, the membrane resistance of the soma (rm) and dendrites (rdend), the space constant (λ) and the characteristic dendritic length (L = l/λ). We found that the EPSPs recorded from the somata were similar regardless on the neuron size. However, the amplitude of the EPSPs and the firing frequency of the neurons were inversely proportional to the coupling ratio of the neuron pair, which also was independent from the neuronal size. This data indicated that the integrative constancy relied on the passive membrane properties. We show that the growth of Retzius neurons was compensated by increasing the membrane resistance of the dendrites and therefore the λ value. By solely increasing the dendrite resistance this circuit maintains

  9. Life history and propagation of the endangered dromedary pearlymussel (Dromus dromas) (Bivalvia:Unionidae)

    USGS Publications Warehouse

    Jones, J.W.; Neves, R.J.; Ahlstedt, S.A.; Mair, R.A.

    2004-01-01

    The reproduction, demography, and propagation of the endangered dromedary pearlymussel (Dromus dromas) (Lea, 1834) were studied in the Clinch and Powell rivers, Tennessee. Viable populations of the dromedary pearlymussel now occur only in the Clinch and Powell rivers; the species has been extirpated from the remaining portions of its range in the Cumberland and Tennessee river drainages. Females are long-term winter brooders, and they are gravid from October to June. Glochidia are contained in conglutinates that are red to white and resemble freshwater leeches or flatworms. Conglutinates are 20 to 40 mm long and are released through the excurrent aperture. Estimates of fecundity based on 7 gravid females collected from the Clinch River were 55,110 to 253,050 glochidia/mussel. The ages of 66 valves of D. dromas were determined by thin-sectioning and ranged from 3 to 25 y. Annual growth averaged 5 mm/y until age 10 and decreased to ???1.2 mm/ y thereafter. Nineteen fish species were tested for suitability as hosts for glochidia. Ten were confirmed as hosts through induced infestations of glochidia: black sculpin (Cottus baileyi), greenside darter (Etheostoma blennioides), fantail darter (Etheostoma flabellare), snubnose darter (Etheostoma simoterum), tangerine darter (Percina aurantiaca), blotchside logperch (Percina burtoni), logperch (Percina caprodes), channel darter (Percina copelandi), gilt darter (Percina evides), and Roanoke darter (Percina roanoka). Juveniles produced from these hosts were cultured in dishes held in nonrecirculating aquaculture systems containing fine sediment (<105 ??m) and were fed the green alga Nannochloropsis oculata every 2 d. Survival of 2810 newly metamorphosed juveniles was 836 (29.7%) after 1 to 2 wk.

  10. The making of indigenous vascular prosthesis

    PubMed Central

    Unnikrishnan, Madathipat; Viswanathan, Sidharth; Balasubramaniam, K.; Muraleedharan, C.V.; Lal, Arthur Vijayan; Mohanan, P.V.; Mohanty, Meera; Kapilamoorthy, Tirur Raman

    2016-01-01

    Background & objectives: Vascular illnesses are on the rise in India, due to increase in lifestyle diseases and demographic transition, requiring intervention to save life, organ or limbs using vascular prosthesis. The aim of this study was to develop indigenous large diameter vascular graft for treatment of patients with vascular pathologies. Methods: The South India Textile Research Association, at Coimbatore, Tamil Nadu, India, developed seamless woven polyester (Polyethylene terephthalate) graft at its research wing. Further characterization and testing followed by clinical trials were conducted at Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala, India. Fifteen in vivo experiments were carried out in 1992-1994 in pigs as animal model. Controlled (phase I) clinical trial in ten patients was performed along with control graft. Thereafter, phase II trial involved 22 patients who underwent multi-centre clinical trial in four centres across India. Results: Laboratory testing showed that polyester graft was non-toxic, non-leeching and non-haemolytic with preserved long-term quality, further confirming in pigs by implanting in thoracic aorta, comparable to control Dacron grafts. Perigraft incorporation and smooth neointima formation which are prime features of excellent healing characteristics, were noted at explantation at planned intervals. Subsequently in the phase I and II clinical trials, all patients had excellent recovery without mortality or device-related adverse events. Patients receiving the test graft were followed up for 10 and 5 years, respectively. Serial clinical, duplex scans and CT angiograms performed periodically confirmed excellent graft performance. Interpretation & conclusions: Indigenously developed Chitra vascular graft was comparable to commercially available Dacron graft, ready for clinical use at affordable cost to patients as against costly imported grafts. PMID:27748302

  11. Adverse event reporting in nonpharmacologic, noninterventional pain clinical trials: ACTTION systematic review.

    PubMed

    Hunsinger, Matthew; Smith, Shannon M; Rothstein, Daniel; McKeown, Andrew; Parkhurst, Melissa; Hertz, Sharon; Katz, Nathaniel P; Lin, Allison H; McDermott, Michael P; Rappaport, Bob A; Turk, Dennis C; Dworkin, Robert H

    2014-11-01

    Assessment of treatment safety is 1 of the primary goals of clinical trials. Organizations and working groups have created reporting guidelines for adverse events (AEs). Previous research examining AE reporting for pharmacologic clinical trials of analgesics in major pain journals found many reporting inadequacies, suggesting that analgesic trials are not adhering to existing AE reporting guidelines. The present systematic review documented AE reporting in 3 main pain journals for nonpharmacologic, noninterventional (NP/NI) trials examining pain treatments. To broaden our pool of nonpharmacologic trials, we also included trials examining acupuncture, leech therapy, and noninvasive stimulation techniques (eg, transcutaneous electrical nerve stimulation). We documented AE reporting at 2 levels of specificity using coding manuals based on the Consolidated Standards of Reporting Trials (CONSORT) harms reporting standards and Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks (ACTTION) AE reporting checklist. We identified a number of inadequacies in AE reporting across the 3 journals. For example, using the ACTTION coding manual, we found that less than one-half of the trials reported specific AE assessment methods; approximately one-third of the trials reported withdrawals due to AEs for each study arm; and about one-fourth of the trials reported all specific AEs. We also examined differences in AE reporting across several trial characteristics, finding that AE reporting was generally more detailed in trials with patients versus those using healthy volunteers undergoing experimentally evoked pain. These results suggest that investigators conducting and reporting NP/NI clinical trials are not adequately describing the assessment and occurrence of AEs.

  12. Expression patterns indicate that BMP2/4 and Chordin, not BMP5-8 and Gremlin, mediate dorsal-ventral patterning in the mollusk Crassostrea gigas.

    PubMed

    Tan, Sujian; Huan, Pin; Liu, Baozhong

    2016-12-16

    Though several bilaterian animals use a conserved BMP2/4-Chordin antagonism to pattern the dorsal-ventral (DV) axis, the only lophotrochozoan species in which early DV patterning has been studied to date, the leech Helobdella robusta, appears to employ BMP5-8 and Gremlin. These findings call into question the conservation of a common DV patterning mechanism among bilaterian animals. To explore whether the unusual DV patterning mechanism in H. robusta is also used in other lophotrochozoan species, we investigated the expression of orthologous genes in the early embryo of a bivalve mollusk, Crassostrea gigas. Searching of the genome and phylogenetic analysis revealed that C. gigas possesses single orthologs of BMP2/4, Chordin, and BMP5-8 and no Gremlin homolog. Whole mount in situ hybridization revealed mRNA localization of BMP2/4 and Chordin on the opposite sides of embryos, suggesting the potential involvement of a BMP2/4-Chordin antagonism in DV patterning in this species. Furthermore, universal BMP5-8 expression and the absence of a Gremlin homolog in the C. gigas genome called into question any major contribution by BMP5-8 and Gremlin to early DV patterning in this species. Additionally, we identified seven genes showing asymmetric expression along the DV axis, providing further insight into DV patterning in C. gigas. We present the first report of a Chordin gene in a lophotrochozoan species and of the opposite expression of BMP2/4 (dorsal) and Chordin (ventral) along the D/V axis of a lophotrochozoan embryo. The findings of this study further the knowledge of axis formation in lophotrochozoan species and provide insight into the evolution of the animal DV patterning mechanism.

  13. Thrombin immobilized to extracellular matrix is a potent mitogen for vascular smooth muscle cells: nonenzymatic mode of action.

    PubMed Central

    Bar-Shavit, R; Benezra, M; Eldor, A; Hy-Am, E; Fenton, J W; Wilner, G D; Vlodavsky, I

    1990-01-01

    Esterolytically inactive diisopropyl fluorophosphate-conjugated thrombin (DIP-alpha-thrombin) stimulated 3H-thymidine incorporation and proliferation of growth-arrested vascular smooth muscle cells (SMCs), similar to native alpha-thrombin. Half-maximal mitogenic response of SMCs was obtained at 1 nM thrombin and was specifically blocked by the leech-derived, high-affinity thrombin inhibitor, hirudin. Native thrombin and a variety of thrombin species that were chemically modified to alter thrombin procoagulant or esterolytic functions were found to induce 3H-thymidine incorporation to a similar extent. Exposure of SMCs to DIP-alpha-thrombin caused a rapid and transient expression of the c-fos protooncogene, determined by Northern blot analysis. These results indicate that thrombin is a potent mitogen for SMCs through a distinct non-enzymatic domain. Binding of 125I-alpha-thrombin to SMC cultures revealed an apparent dissociation constant of 6 nM and an estimated 5.4 x 10(5) binding sites per cell. This binding was inhibited to the same extent by native thrombin and by its nonenzymatic form, DIP-alpha-thrombin. Moreover, the chemotactic fragment of thrombin (CB67-129), which failed to elicit a mitogenic response, competed for 125I-alpha-thrombin binding to SMCs. Cross-linking analysis of 125I-alpha-thrombin to SMCs revealed a specific cell-surface binding site 55 kDa in size. Finally, thrombin immobilized to a naturally produced extracellular matrix retained potent mitogenic activity toward SMCs. These observations lend support to the possibility that in vivo, subendothelial basement membranes sequester thrombin (as well as other bioactive molecules), which may stimulate localized and persistent growth of arterial SMCs. Thrombin may thus be involved directly in progression of atherosclerotic plaque formation. Images PMID:1963793

  14. A Creek to Bay Biological Assessment in Oakland, California

    NASA Astrophysics Data System (ADS)

    Ahumada, E.; Ramirez, N.; Lopez, A.; Avila, M.; Ramirez, J.; Arroyo, D.; Bracho, H.; Casanova, A.; Pierson, E.

    2011-12-01

    In 2007, the Surface Water Ambient Monitoring Program (SWAMP) assessed the impact of trash on water quality in the Peralta Creek which is located in the Fruitvale district of Oakland, CA. This 2011 follow-up study will take further steps in evaluating the physical and biological impacts of pollution and human development on Peralta Creek and in the San Leandro Bay, where the Creek empties into the larger San Francisco Bay estuary. This study will utilize two forms of biological assessment in order to determine the level of water quality and ecosystem health of Peralta Creek and San Leandro Bay in Oakland, California. A Rapid Bioassesment Protocal (RBP) will be used as the method of biological assessment for Peralta Creek. RBP uses a biotic index of benthic macroinvertebrates to provide a measure of a water body's health. Larval trematodes found in two mud snails (Ilynassa obsoleta and Cerithidea californica) will be used to evaluate the health of the San Leandro Bay. Due to the complex life cycle of trematodes, the measure of trematode diversity and richness in host species serves as an indicator of estuarine health (Huspeni 2005). We have completed the assessment of one section of Peralta Creek, located at 2465 34th Avenue, Oakland, CA 94601. Abundance results indicate a moderately healthy creek because there were high levels of pollution tolerant benthic macroinvertebrates. The tolerant group of benthic macroinvertebrates includes such organisms as flatworms, leeches, and scuds. This is possibly due to this section of the creek being pumped up to the surface from culverts impacting the macroinvertebrate's life cycle. Another contributing factor to creek health is the amount of organic debris found in the creek, which inhibits the flow and oxygenation of the water, allowing for more pollution tolerant aquatic insects to persist. Further investigation is being conducted to fully assess the Peralta Creek watershed; from the preliminary results one can surmise that

  15. Parasites of native and nonnative fishes of the Little Colorado River, Grand Canyon, Arizona

    USGS Publications Warehouse

    Choudhury, A.; Hoffnagle, T.L.; Cole, R.A.

    2004-01-01

    A 2-yr, seasonal, parasitological study of 1,435 fish, belonging to 4 species of native fishes and 7 species of nonnative fishes from the lower Little Colorado River (LCR) and tributary creeks, Grand Canyon, Arizona, yielded 17 species of parasites. These comprised 1 myxozoan (Henneguya exilis), 2 copepods (Ergasilus arthrosis and Lernaea cyprinacea), 1 acarine (Oribatida gen. sp.), 1 piscicolid leech (Myzobdella lugubris), 4 monogeneans (Gyrodactylus hoffmani, Gyrodactylus sp., Dactylogyrus extensus, and Ligictaluridus floridanus), 4 nematodes (Contracaecum sp., Eustrongylides sp., Rhabdochona sp., and Truttaedacnitis truttae), 3 cestodes (Bothriocephalus acheilognathi, Corallobothrium fimbriatum, and Megathylacoides giganteum), and 2 trematodes (Ornithodiplostomum sp. and Posthodiplostomum sp.). Rhabdochona sp. was the only adult parasite native to the LCR. Infection intensities of Ornithodiplostomum sp. and B. acheilognathi were positively correlated with length of the humpback chub Gila cypha. Adult helminths showed a high degree of host specificity, except B. acheilognathi, which was recovered from all fish species examined but was most abundant in cyprinids. Abundance of B. acheilognathi in the humpback chub was highest in the fall and lowest in the summer in both reaches of the LCR. There was no major taxonomic difference in parasite assemblages between the 2 different reaches of the river (LC1 and LC2). Parasite community diversity was very similar in humpback chub, regardless of sampling site or time. The parasite fauna of the LCR is numerically dominated by B. acheilognathi and metacercariae of Ornithodiplostomum sp. The richest and most diverse component community occurred in a nonnative species, the channel catfish Ictalurus punctatus, but infracommunity species richness was highest in a native host, humpback chub.

  16. High Prevalence of Multistability of Rest States and Bursting in a Database of a Model Neuron

    PubMed Central

    Marin, Bóris; Barnett, William H.; Doloc-Mihu, Anca; Calabrese, Ronald L.; Cymbalyuk, Gennady S.

    2013-01-01

    Flexibility in neuronal circuits has its roots in the dynamical richness of their neurons. Depending on their membrane properties single neurons can produce a plethora of activity regimes including silence, spiking and bursting. What is less appreciated is that these regimes can coexist with each other so that a transient stimulus can cause persistent change in the activity of a given neuron. Such multistability of the neuronal dynamics has been shown in a variety of neurons under different modulatory conditions. It can play either a functional role or present a substrate for dynamical diseases. We considered a database of an isolated leech heart interneuron model that can display silent, tonic spiking and bursting regimes. We analyzed only the cases of endogenous bursters producing functional half-center oscillators (HCOs). Using a one parameter (the leak conductance ()) bifurcation analysis, we extended the database to include silent regimes (stationary states) and systematically classified cases for the coexistence of silent and bursting regimes. We showed that different cases could exhibit two stable depolarized stationary states and two hyperpolarized stationary states in addition to various spiking and bursting regimes. We analyzed all cases of endogenous bursters and found that 18% of the cases were multistable, exhibiting coexistences of stationary states and bursting. Moreover, 91% of the cases exhibited multistability in some range of . We also explored HCOs built of multistable neuron cases with coexisting stationary states and a bursting regime. In 96% of cases analyzed, the HCOs resumed normal alternating bursting after one of the neurons was reset to a stationary state, proving themselves robust against this perturbation. PMID:23505348

  17. In silico designing of a new cysteine analogue of hirudin variant 3 for site specific PEGylation

    PubMed Central

    Sajjadi, Seyed Mehdi; Rahimi, Hamzeh; Mohammadi, Saeed; Faranoush, Mohammad; Mirzahoseini, Hasan; Toogeh, Gholamreza

    2017-01-01

    Hirudin is an anticoagulant agent of the salivary glands of the medicinal leech. Recombinant hirudin (r-Hir) displays certain drawbacks including bleeding and immunogenicity. To solve these problems, cysteine-specific PEGylation has been proposed as a successful technique. However, proper selection of the appropriate cysteine residue for substitution is a critical step. This study has, for the first time, used a computational approach aimed at identifying a single potential PEGylation site for replacement by cysteine residue in the hirudin variant 3 (HV3). Homology modeling (HM) was performed using MODELLER. All non-cysteine residues of the HV3 were replaced with the cysteine. The best model was selected based on the results of discrete optimized protein energy score, PROCHECK software, and Verify3D. The receptor binding was investigated using protein-protein docking by ClusPro web tool which was then visualized using LigPlot+ software and PyMOL. Finally, multiple sequence alignment (MSA) using ClustalW software and disulfide bond prediction were performed. According to the results of HM and docking, Q33C, which was located on the surface of the protein, was the best site for PEGylation. Furthermore, MSA showed that Q33 was not a conserved residue and LigPlot+ software showed that it is not involved in the hirudin-thrombin binding pocket. Moreover, prediction softwares established that it is not involved in disulfide bond formation. In this study, for the first time, the utility of the in silico approach for creating a cysteine analogue of HV3 was introduced. Our study demonstrated that the substitution of Q33 by cysteine probably has no effect on the biological activity of the HV3. However, experimental analyses are required to confirm the results. PMID:28255315

  18. Chemical synthesis and structural characterization of the RGD-protein decorsin: a potent inhibitor of platelet aggregation.

    PubMed Central

    Polverino de Laureto, P.; Scaramella, E.; De Filippis, V.; Marin, O.; Doni, M. G.; Fontana, A.

    1998-01-01

    Decorsin is a 39-residue RGD-protein crosslinked by three disulfide bridges isolated from the leech Macrobdella decora belonging to the family of GPIIb-IIIa antagonists and acting as a potent inhibitor of platelet aggregation. Here we report the solid-phase synthesis of decorsin using the Fmoc strategy. The crude polypeptide was purified by reverse-phase HPLC in its reduced form and allowed to refold in the presence of glutathione. The homogeneity of the synthetic oxidized decorsin was established by reverse-phase HPLC and capillary zone electrophoresis. The results of amino acid analysis after acid hydrolysis of the synthetic protein, NH2-terminal sequencing and mass determination (4,377 Da) by electrospray mass spectrometry were in full agreement with this theory. The correct pairing of the three disulfide bridges in synthetic decorsin was determined by a combined approach of both peptide mapping using proteolytic enzymes and analysis of the disulfide chirality by CD spectroscopy in the near-UV region. Synthetic decorsin inhibited human platelet aggregation with an IC50 of approximately 0.1 microM, a figure quite similar to that determined utilizing decorsin from natural source. In particular, the synthetic protein was 2,000-fold more potent than a model RGD-peptide (e.g., Arg-Gly-Asp-Ser) in inhibiting platelet aggregation. Thermal denaturation experiments of synthetic decorsin, monitored by CD spectroscopy, revealed its high thermal stability (Tm approximately 74 degrees C). The features of the oxidative refolding process of reduced decorsin, as well as the thermal stability of the oxidized species, were compared with those previously determined for the NH2-terminal core domain fragment 1-41 or 1-43 from hirudin. This fragment shows similarity in size, pairing of the three disulfides and three-dimensional structure with those of decorsin, even if very low sequence similarity. It is suggested that the less efficient oxidative folding and the enhanced thermal

  19. Biophysics of active vesicle transport, an intermediate step that couples excitation and exocytosis of serotonin in the neuronal soma.

    PubMed

    De-Miguel, Francisco F; Santamaría-Holek, Iván; Noguez, Paula; Bustos, Carlos; Hernández-Lemus, Enrique; Rubí, J Miguel

    2012-01-01

    Transmitter exocytosis from the neuronal soma is evoked by brief trains of high frequency electrical activity and continues for several minutes. Here we studied how active vesicle transport towards the plasma membrane contributes to this slow phenomenon in serotonergic leech Retzius neurons, by combining electron microscopy, the kinetics of exocytosis obtained from FM1-43 dye fluorescence as vesicles fuse with the plasma membrane, and a diffusion equation incorporating the forces of local confinement and molecular motors. Electron micrographs of neurons at rest or after stimulation with 1 Hz trains showed cytoplasmic clusters of dense core vesicles at 1.5±0.2 and 3.7±0.3 µm distances from the plasma membrane, to which they were bound through microtubule bundles. By contrast, after 20 Hz stimulation vesicle clusters were apposed to the plasma membrane, suggesting that transport was induced by electrical stimulation. Consistently, 20 Hz stimulation of cultured neurons induced spotted FM1-43 fluorescence increases with one or two slow sigmoidal kinetics, suggesting exocytosis from an equal number of vesicle clusters. These fluorescence increases were prevented by colchicine, which suggested microtubule-dependent vesicle transport. Model fitting to the fluorescence kinetics predicted that 52-951 vesicles/cluster were transported along 0.60-6.18 µm distances at average 11-95 nms(-1) velocities. The ATP cost per vesicle fused (0.4-72.0), calculated from the ratio of the ΔG(process)/ΔG(ATP), depended on the ratio of the traveling velocity and the number of vesicles in the cluster. Interestingly, the distance-dependence of the ATP cost per vesicle was bistable, with low energy values at 1.4 and 3.3 µm, similar to the average resting distances of the vesicle clusters, and a high energy barrier at 1.6-2.0 µm. Our study confirms that active vesicle transport is an intermediate step for somatic serotonin exocytosis by Retzius neurons and provides a quantitative method

  20. Conservation, loss, and redeployment of Wnt ligands in protostomes: implications for understanding the evolution of segment formation

    PubMed Central

    2010-01-01

    subfamilies in lineages such as insects, nematodes and leeches, most protostomes have probably maintained much of their ancestral repertoire of twelve Wnt genes. The maintenance of a large set of these ligands could be in part due to their combinatorial activity in various tissues rather than functional redundancy. The activity of such Wnt 'landscapes' as opposed to the function of individual ligands could explain the patterns of conservation and redeployment of these genes in important developmental processes across metazoans. This requires further analysis of the expression and function of these genes in a wider range of taxa. PMID:21122121

  1. Overview of the Proposed Mississippi Headwaters - Red River Hydrologic Observatory

    NASA Astrophysics Data System (ADS)

    Schwartz, F. W.; Gerla, P. J.; Kucera, P. A.

    2004-12-01

    A consortium of universities, led by The Ohio State University and the University of North Dakota, in collaboration with The Nature Conservancy - Minnesota and the Dakotas Chapter, are proposing to develop the Mississippi Headwaters - Red River (MHRR) Hydrologic Observatory (HO). The region encompassed by the observatory includes the Red River watershed, the Upper Crow Wing River, the headwaters of the Mississippi River above Leech Lake, the closed Devils Lake basin and the central portion of the Prairie Pothole Region (PPR). The MHRR HO covers about 101,000 km2 and straddles the continental divide. The large size will permit the study of unique science problems and will provide a large contiguous region suitable for coupled large-scale climatic/hydrologic/ecological investigations. Although not part of this proposal, we are also organizing a consortium of primarily Canadian universities interested in carrying out complementary studies on the large Assiniboine basin in Manitoba and Saskatchewan with funding from Canadian sources. The combined study areas will facilitate climate/hydrologic/ecological studies on a broad scale, together with much more focused local scale studies. The research plan focuses on (i) climate variability and future climate change, (ii) wetland dynamics, restoration, and policy considerations associated with global climate change, (iii) carbon, nutrient, and contaminant cycling in complex systems, (iv) assessment and modeling of large, coupled climate/water systems, and (v) new and emerging technologies for near real-time monitoring and assessment. The science themes focus explicitly on exploring the interfaces among traditional science disciplines (hydrology, ecology, climatology) and implicitly on the atmosphere/land surface/subsurface interfaces that are part of the hydrologic cycle. The location of the MHRR HO was purposely selected as one of the most promising areas to pursue these science and technology themes. The region is

  2. Differential effects of GABA in modulating nociceptive vs. non-nociceptive synapses.

    PubMed

    Wang, Y; Summers, T; Peterson, W; Miiller, E; Burrell, B D

    2015-07-09

    GABA (γ-amino-butyric acid) -mediated signaling is normally associated with synaptic inhibition due to ionotropic GABA receptors that gate an inward Cl(-) current, hyperpolarizing the membrane potential. However, there are also situations where ionotropic GABA receptors trigger a Cl(-) efflux that results in depolarization. The well-characterized central nervous system of the medicinal leech was used to study the functional significance of opposing effects of GABA at the synaptic circuit level. Specifically, we focused on synapses made by the nociceptive N cell and the non-nociceptive P (pressure) cell that converge onto a common postsynaptic target. It is already known that GABA hyperpolarizes the P cell, but depolarizes the N cell and that inhibition of ionotropic GABA receptors by bicuculline (BIC) has opposing effects on the synapses made by these two inputs; enhancing P cell synaptic transmission, but depressing N cell synapses. The goal of the present study was to determine whether the opposing effects of GABA were due to differences in Cl(-) homeostasis between the two presynaptic neurons. VU 0240551 (VU), an inhibitor of the Cl(-) exporter K-Cl co-transporter isoform 2 (KCC2), attenuated GABA-mediated hyperpolarization of the non-nociceptive afferent while bumetanide (BUM), an inhibitor of the Cl(-) importer Na-K-Cl co-transporter isoform 1 (NKCC1), reduced GABA-mediated depolarization of the nociceptive neuron. VU treatment also enhanced P cell synaptic signaling, similar to the previously observed effects of BIC and consistent with the idea that GABA inhibits synaptic signaling at the presynaptic level. BUM treatment depressed N cell synapses, again similar to what is observed following BIC treatment and suggests that GABA has an excitatory effect on these synapses. The opposing effects of GABA could also be observed at the behavioral level with BIC and VU increasing responsiveness to non-nociceptive stimulation while BIC and BUM decreased responsiveness

  3. Biophysics of Active Vesicle Transport, an Intermediate Step That Couples Excitation and Exocytosis of Serotonin in the Neuronal Soma

    PubMed Central

    De-Miguel, Francisco F.; Santamaría-Holek, Iván; Noguez, Paula; Bustos, Carlos; Hernández-Lemus, Enrique; Rubí, J. Miguel

    2012-01-01

    Transmitter exocytosis from the neuronal soma is evoked by brief trains of high frequency electrical activity and continues for several minutes. Here we studied how active vesicle transport towards the plasma membrane contributes to this slow phenomenon in serotonergic leech Retzius neurons, by combining electron microscopy, the kinetics of exocytosis obtained from FM1-43 dye fluorescence as vesicles fuse with the plasma membrane, and a diffusion equation incorporating the forces of local confinement and molecular motors. Electron micrographs of neurons at rest or after stimulation with 1 Hz trains showed cytoplasmic clusters of dense core vesicles at 1.5±0.2 and 3.7±0.3 µm distances from the plasma membrane, to which they were bound through microtubule bundles. By contrast, after 20 Hz stimulation vesicle clusters were apposed to the plasma membrane, suggesting that transport was induced by electrical stimulation. Consistently, 20 Hz stimulation of cultured neurons induced spotted FM1-43 fluorescence increases with one or two slow sigmoidal kinetics, suggesting exocytosis from an equal number of vesicle clusters. These fluorescence increases were prevented by colchicine, which suggested microtubule-dependent vesicle transport. Model fitting to the fluorescence kinetics predicted that 52–951 vesicles/cluster were transported along 0.60–6.18 µm distances at average 11–95 nms−1 velocities. The ATP cost per vesicle fused (0.4–72.0), calculated from the ratio of the ΔGprocess/ΔGATP, depended on the ratio of the traveling velocity and the number of vesicles in the cluster. Interestingly, the distance-dependence of the ATP cost per vesicle was bistable, with low energy values at 1.4 and 3.3 µm, similar to the average resting distances of the vesicle clusters, and a high energy barrier at 1.6–2.0 µm. Our study confirms that active vesicle transport is an intermediate step for somatic serotonin exocytosis by Retzius neurons and provides a quantitative

  4. Lessons Learned in Developing Research Opportunities for Native American Undergraduate Students: The GEMscholars Project

    NASA Astrophysics Data System (ADS)

    Zurn-Birkhimer, S. M.; Filley, T. R.; Kroeger, T. J.

    2008-12-01

    Interventions for the well-documented national deficiency of underrepresented students in higher education have focused primarily on the undergraduate student population with significantly less attention given to issues of diversity within graduate programs. As a result, we have made little progress in transforming faculty composition to better reflect the nation's diversity resulting in relatively few minority mentors joining faculty ranks and schools falling short of the broader representation to create an enriched, diverse academic environment. The GEMscholars (Geology, Environmental Science and Meteorology scholars) Program began in the summer of 2006 with the goal of increasing the number of Native American students pursuing graduate degrees in the geosciences. We drew on research from Native American student education models to address three key themes of (a) mentoring, (b) culturally relevant valuations of geosciences and possible career paths, and (c) connections to community and family. A collaboration between Purdue University, West Lafayette, IN and three institutions in northern Minnesota; Bemidji State University, Red Lake Nation College and Leech Lake Tribal College, is structured to develop research opportunities and a support network for Native American undergraduate students (called GEMscholars) to participate in summer geoscience research projects in their home communities. Research opportunities were specifically chosen to have cultural relevance and yield locally important findings. The GEMscholars work on projects that directly link to their local ecosystems and permit them to engage in long term monitoring and cohesive interaction among each successive year's participants. For example, the GEMscholars have established and now maintain permanent field monitoring plots to assess the impacts of invasive European earthworm activity on forest ecosystem health. The culmination of the summer project is the GEMscholars Symposium at Purdue University

  5. Cleavage pattern and fate map of the mesentoblast, 4d, in the gastropod Crepidula: a hallmark of spiralian development

    PubMed Central

    2012-01-01

    Background Animals with a spiral cleavage program, such as mollusks and annelids, make up the majority of the superphylum Lophotrochozoa. The great diversity of larval and adult body plans in this group emerges from this highly conserved developmental program. The 4d micromere is one of the most conserved aspects of spiralian development. Unlike the preceding pattern of spiral divisions, cleavages within the 4d teloblastic sublineages are bilateral, representing a critical transition towards constructing the bilaterian body plan. These cells give rise to the visceral mesoderm in virtually all spiralians examined and in many species they also contribute to the endodermal intestine. Hence, the 4d lineage is an ideal one for studying the evolution and diversification of the bipotential endomesodermal germ layer in protostomes at the level of individual cells. Little is known of how division patterns are controlled or how mesodermal and endodermal sublineages diverge in spiralians. Detailed modern fate maps for 4d exist in only a few species of clitellate annelids, specifically in glossiphoniid leeches and the sludge worm Tubifex. We investigated the 4d lineage in the gastropod Crepidula fornicata, an established model system for spiralian biology, and in a closely related direct-developing species, C. convexa. Results High-resolution cell lineage tracing techniques were used to study the 4d lineage of C. fornicata and C. convexa. We present a new nomenclature to name the progeny of 4d, and report the fate map for the sublineages up through the birth of the first five pairs of teloblast daughter cells (when 28 cells are present in the 4d sublineage), and describe each clone’s behavior during gastrulation and later stages as these undergo differentiation. We identify the precise origin of the intestine, two cells of the larval kidney complex, the larval retractor muscles and the presumptive germ cells, among others. Other tissues that arise later in the 4d lineage

  6. Summary of biological and contaminant investigations related to stream water quality and environmental setting in the Upper Colorado River basin, 1938-95

    USGS Publications Warehouse

    Deacon, Jeffrey R.; Stephens, Verlin C.

    1996-01-01

    As part of the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) program, an inventory of the biological and contaminant investigations for the Upper Colorado River Basin study unit was conducted. To enhance the sampling design for the biological component of the program, previous studies about the ecology of aquatic organisms and contaminants were compiled from computerized literature searches of biological data bases and by contacting other Federal, State, and local agencies. Biological and contaminant investigations that have been conducted throughout the basin since 1938 were categorized according to four general categories of biological investigations and two categories of contaminant investigations: algal communities, macroinvertebrate communities, fish communities, habitat characterization, contaminants in organism tissue, and contaminants in bed sediment. The studies were identified by their locations in two physiographic provinces, the Southern Rocky Mountains and the Colorado Plateau, and by the predominant land use in the area of the investigation. Studies on algal communities and contaminants in organism tissue and in bed sediment are limited throughout the basin. Studies on macroinvertebrate and fish communities and habitat characterization are the most abundant in the study unit. Natural and human factors can affect biological communities and their composition. Natural factors that affect background water-quality conditions are physiography, climate, geology, and soils. Algae, macroinvertebrates, and fish that are present in the Southern Rocky Mountains and the Colorado Plateau physiographic provinces vary with altitude and physical environment. Green algae and diatoms are predominant in the higher altitude streams, and blue-green, golden-brown, and green algae are predominant in the lower altitude streams. Caddisflies, mayflies, and stoneflies are the dominant macroinvertebrates in the higher altitudes, whereas aquatic worms, leeches

  7. Proteinase inhibitors in severe inflammatory processes (septic shock and experimental endotoxaemia): biochemical, pathophysiological and therapeutic aspects.

    PubMed

    Fritz, H

    1979-01-01

    course of a local inflammatory response. Preliminary results indicate that HUSI-I, which is produced by the epithelial cells of mucous membranes, does not belong to any known structural type of acid-stable proteinase inhibitor. The search for other candidates suitable for medication in humans led to the discovery of a potent elastase--cathepsin G inhibitor, called eglin, in the leech Hirudo medicinalis. This acid-stable inhibitor with a molecular weight close to 8100 has an unusual structural property in that the structure of the molecule is not stabilized by any disulphide bridge.

  8. Spring viremia of carp

    USGS Publications Warehouse

    Ahne, W.; Bjorklund, H.V.; Essbauer, S.; Fijan, N.; Kurath, G.; Winton, J.R.

    2002-01-01

    pring viremia of carp (SVC) is an important disease affecting cyprinids, mainly common carp Cyprinus carpio. The disease is widespread in European carp culture, where it causes significant morbidity and mortality. Designated a notifiable disease by the Office International des Epizooties, SVC is caused by a rhabdovirus, spring viremia of carp virus (SVCV). Affected fish show destruction of tissues in the kidney, spleen and liver, leading to hemorrhage, loss of water-salt balance and impairment of immune response. High mortality occurs at water temperatures of 10 to 17°C, typically in spring. At higher temperatures, infected carp develop humoral antibodies that can neutralize the spread of virus and such carp are protected against re-infection by solid immunity. The virus is shed mostly with the feces and urine of clinically infected fish and by carriers. Waterborne transmission is believed to be the primary route of infection, but bloodsucking parasites like leeches and the carp louse may serve as mechanical vectors of SVCV. The genome of SVCV is composed of a single molecule of linear, negative-sense, single-stranded RNA containing 5 genes in the order 3¹-NPMGL-5¹ coding for the viral nucleoprotein, phosphoprotein, matrix protein, glycoprotein, and polymerase, respectively. Polyacrylamide gel electrophoresis of the viral proteins, and sequence homologies between the genes and gene junctions of SVCV and vesicular stomatitis viruses, have led to the placement of the virus as a tentative member of the genus Vesiculovirus in the family Rhabdoviridae. These methods also revealed that SVCV is not related to fish rhabdoviruses of the genus Novirhabdovirus. In vitro replication of SVCV takes place in the cytoplasm of cultured cells of fish, bird and mammalian origin at temperatures of 4 to 31°C, with an optimum of about 20°C. Spring viremia of carp can be diagnosed by clinical signs, isolation of virus in cell culture and molecular methods. Antibodies directed

  9. An ultrastructural study of the ovary cord organization and oogenesis in Erpobdella johanssoni (Annelida, Clitellata: Hirudinida).

    PubMed

    Ben Ahmed, Raja; Tekaya, Saïda; Małota, Karol; Świątek, Piotr

    2013-01-01

    The aims of the present study were to analyze the ovary cord structure and oogenesis in Erpobdella johanssoni under light, fluorescent and transmission electron microscopy and to compare the obtained results with other clitellate annelids, especially with other arhynchobdellid leeches. Each of the paired ovaries is composed of the ovary wall (ovisac) and several (7-8) short, cone-shaped ovary cords. The ovary cords are of the "Erpobdella" type, i.e. they are short and polarized and five zones containing germ cells at consecutives stages of their development can be distinguished along their long axis. One, huge somatic cell (the apical cell), oogonia and premeiotic germ cells occur at the tip of the apical part of the ovary cord - zone I. Below, in zone II germ cells enter meiosis, whereas in zone III only a few cells continue meiosis and gather nutrients (oocytes), while the rest become nurse cells. In zone IV, huge vitellogenic oocytes form protuberances on the surface of the cord, and degenerating germ cells were observed at the base of the ovary cord (zones IV and V). The germline cells form syncytial cysts in zones I-III. The germline cysts have broadly the same architecture as in the ovaries of all of the clitellate annelids that have been described to date. Each germ cell in a cyst has only one cytoplasmic bridge connecting it to the common cytoplasmic mass - the cytophore. The cytophore is poorly developed, and it has the form of thin, long cytoplasmic strands. The presence of two categories of germ cells suggests a meroistic mode of oogenesis. The germline cysts are closely associated with somatic, follicular cells. There are two subpopulations of follicular cells: one envelops the growing oocytes, while the second is distributed between other germ cells. The entire ovary cord is additionally enveloped by a layer of somatic cells with a spongy appearance - the spongiosa cells. A characteristic feature of vitellogenic oocytes is the condensation of the

  10. Geologic map of the Wildcat Lake 7.5' quadrangle: Kitsap and Mason counties, Washington

    USGS Publications Warehouse

    Haeussler, Peter J.; Clark, Kenneth P.

    2000-01-01

    The Wildcat Lake quadrangle lies in the forearc of the Cascadia subduction zone, about 20-km east of the Cascadia accretionary complex exposed in the Olympic Mountains (Tabor and Cady, 1978),and about 100-km west of the axis of the Cascades volcanic arc. The quadrangle lies near the middle of the Puget Lowland, which typically has elevations less than 600 feet (183 m), but on Gold Mountain, in the center of the quadrangle, the elevation rises to 1761 feet (537 m). This anomalously high topography also provides a glimpse of the deeper crust beneath the Lowland. Exposed on Green and Gold Mountains are rocks related to the Coast Range basalt terrane. This terrane consists of Eocene submarine and subaerial tholeiitic basalt of the Crescent Formation, which probably accreted to the continental margin in Eocene time (Snavely and others, 1968). The Coast Range basalt terrane may have originated as an oceanic plateau or by oblique marginal rifting (Babcock and others, 1992), but its subsequent emplacement history is complex (Wells and others, 1984). In southern Oregon, onlapping strata constrain the suturing to have occured by 50 Ma; but on southern Vancouver Island where the terrane-bounding Leech River fault is exposed, Brandon and Vance (1992) concluded suturing to North America occurred in the broad interval between 42 and 24 Ma. After emplacement of the Coast Range basalt terrane, the Cascadia accretionary complex,exposed in the Olympic Mountains west of the quadrangle,developed by frontal accretion and underplating (e.g., Clowes and others, 1987). The Seattle basin, part of which lies to the north of Green Mountain, also began to develop in late Eocene time due to forced flexural subsidence along the Seattle fault zone (Johnson and others, 1994). Domal uplift of the accretionary complex beneath the Olympic Mountains occurred after approximately 18 million years ago (Brandon and others, 1998). Ice-sheet glaciation during Quaternary time reshaped the topography of the

  11. Ethnobotany of the Monpa ethnic group at Arunachal Pradesh, India

    PubMed Central

    2011-01-01

    Background The present paper documents the uses of plants in traditional herbal medicine for human and veterinary ailments, and those used for dietary supplements, religious purpose, local beverage, and plants used to poison fish and wild animals. Traditional botanical medicine is the primary mode of healthcare for most of the rural population in Arunachal Pradesh. Materials and methods Field research was conducted between April 2006 and March 2009 with randomly selected 124 key informants using semi-structured questionnaire. The data obtained was analyzed through informant consensus factor (FIC) to determine the homogeneity of informant's knowledge on medicinal plants. Results We documented 50 plants species belonging to 29 families used for treating 22 human and 4 veterinary ailments. Of the medicinal plants reported, the most common growth form was herbs (40%) followed by shrubs, trees, and climbers. Leaves were most frequently used plant parts. The consensus analysis revealed that the dermatological ailments have the highest FIC (0.56) and the gastro-intestinal diseases have FIC (0.43). FIC values indicated that there was high agreement in the use of plants in dermatological and gastro-intestinal ailments category among the users. Gymnocladus assamicus is a critically rare and endangered species used as disinfectant for cleaning wounds and parasites like leeches and lice on livestocks. Two plant species (Illicium griffithii and Rubia cordifolia) are commonly used for traditional dyeing of clothes and food items. Some of the edible plants recorded in this study were known for their treatment against high blood pressure (Clerodendron colebrookianum), diabetes mellitus (Momordica charantia), and intestinal parasitic worms like round and tape worms (Lindera neesiana, Solanum etiopicum, and Solanum indicum). The Monpas of Arunachal Pradesh have traditionally been using Daphne papyracea for preparing hand-made paper for painting and writing religious scripts in

  12. Macrolepidoptera biodiversity in Wooster, Ohio from 2001 through 2009

    PubMed Central

    Downer, Roger A.; Ebert, Timothy A.

    2014-01-01

    Abstract A Skinner mercury vapor light trap was operated from 2001 through 2009 in a residential backyard to document biodiversity within the moth families Thyatiridae, Drepanidae, Geometridae, Mimallonidae, Apatelodidae, Lasiocampidae, Saturniidae, Sphingidae, Erebidae (including Lymantriinae and Arctiinae), Euteliidae, Nolidae, and Noctuidae. When making comparisons to older literature, we recalculated our results to conform to the older classification of the Noctuoidea. Moths were released after identification. There were 501 species documented in 77581 captures from 1290 sampling dates. There was a perceived risk that released moths would fly back into the trap the following evening. This should result in an abnormal number of rare moths that are caught multiple times. The number of species caught twice versus the number caught once was no different than a similar ratio for surveys that used more traditional sampling methods. Therefore this concern does not seem to be valid for these data. These data are provided in a supplementary file available for download. There were three previous surveys conducted in nearby natural areas. They documented fewer species than were documented here. To understand this better, we examined several specialized groups of moths that tend to use host plants not typically found in an urban residential yard. More species in Schinia Hübner, Catocala Schrank, Acronicta Ochsenheimer, and Herminiinae Leech were found in this survey than the other local surveys. Only in the Papaipema Smith did we recover fewer species, though it was still above 70% of what was expected. This diversity could be a result of sampling effort, but it shows that this urban location has a very diverse moth fauna. We suggest that this diversity is partly due to the planting of native plant species in the area about the light trap. Therefore we would concur with others that urban landscapes can be planned to increase biodiversity relevant to more natural

  13. Lidar-revised geologic map of the Uncas 7.5' quadrangle, Clallam and Jefferson Counties, Washington

    USGS Publications Warehouse

    Tabor, Rowland W.; Haeussler, Peter J.; Haugerud, Ralph A.; Wells, Ray E.

    2011-01-01

    uplifted and tilted eastward the Coast Range basalt basement and overlying marginal basin strata, which comprise most of the rocks of the Uncas quadrangle. The Eocene submarine and subaerial tholeiitic basalt of the Crescent Formation on the Olympic Peninsula is thought to be the exposed mafic basement of the Coast Range, which was considered by Snavely and others (1968) to be an oceanic terrane accreted to the margin in Eocene time. In this interpretation, the Coast Range basalt terrane may have originated as an oceanic plateau or by oblique marginal rifting, but its subsequent emplacement history was complex (Wells and others, 1984). Babcock and others (1992) and Haeussler and others (2003) favor the interpretation that the basalts were the product of an oceanic spreading center interacting with the continental margin. Regardless of their origin, onlapping strata in southern Oregon indicate that the Coast Range basalts were attached to North America by 50 Ma; but on southern Vancouver Island, where the terrane-bounding Leech River Fault is exposed, Brandon and Vance (1992) concluded that suturing to North America occurred in the broad interval between 42 and 24 Ma. After emplacement of the Coast Range basalt terrane, the Cascadia accretionary wedge developed by frontal accretion and underplating (Tabor and Cady, 1978b; Clowes and others, 1987). Domal uplift of the part of the accretionary complex beneath the Olympic Mountains occurred after ~18 Ma (Brandon and others, 1998). Continental and alpine glaciation during Quaternary time reshaped the uplifted rocks of the Olympic Mountains.

  14. Mixed vascular nevus syndrome: a report of four new cases and a literature review

    PubMed Central

    Polizzi, Agata; Strano, Serena; Schepis, Carmelo; Morano, Massimiliano; Belfiore, Giuseppe; Palmucci, Stefano; Foti, Pietro Valerio; Pirrone, Concetta; Sofia, Vito; David, Emanuele; Salpietro, Vincenzo; Mankad, Kshitij; Milone, Pietro

    2016-01-01

    Background Mixed vascular nevus (or nevus vascularis mixtus) represents an admixture of cutaneous vascular malformations of the telangiectatic type and angiospastic spots of nevus anemicus. It can occur as an purely cutaneous trait or as a hallmark of a neurocutaneous phenotype (mixed vascular nevus syndrome) characterised by the combination of: (I) paired vascular (telangiectatic and anemic) twin nevi and brain abnormalities of the Dyke-Davidoff-Masson type (i.e., crossed cerebral/cerebellar hemiatrophy with hypoplasia of the ipsilateral cerebral vessels and homolateral hypertrophy of the skull and sinuses (hyperpneumatisation) with contralateral hemispheric hypertrophy); or (II) paired vascular twin nevi and brain malformations of the Dyke-Davidoff-Masson type in association with systemic abnormalities consisting in facial asymmetry, skeletal anomalies (i.e., Legg-Calvé-Perthes-like disease) and disorders of autoimmunity (i.e., diabetes, thyroiditis). In 2014, Happle proposed to name the syndrome with the eponym Ruggieri-Leech syndrome. Methods Review of the existing literature on nevus vascularis mixtus and information on our personal experience on new cases and follow-up of previously reported cases by some of us. Results The existing literature revealed 4 previous studies including 33 cases with an inferred purely cutaneous trait and 3 cases with a combination of paired vascular twin nevi and brain malformation of the Dyke-Davidoff-Masson type. Our personal experience includes 4 unpublished patients (1 female and 3 males; currently aged 2 to 34 years) seen and followed-up at our Institutions in Italy who had: paired vascular nevi involving either the face (n=2) or the face and parts of the body (n=2); facial asymmetry (n=4); mild to moderate facial dysmorphic features (n=2); developmental delay (n=3); seizures/stroke-like episodes and associated hemiplegia (n=4); muscular hypotrophy (n=2); mild to moderate hemispheric atrophy (n=4); skull osseous hypertrophy

  15. HYALURONIDASES OF BACTERIAL AND ANIMAL ORIGIN.

    PubMed

    Meyer, K; Chaffee, E; Hobby, G L; Dawson, M H

    1941-02-28

    Hyaluronidase has been investigated in various strains of pneumococci and hemolytic streptococci, and in some material of animal origin. The enzyme activity was measured by a viscosimetric method using as a substrate a fluid containing hyaluronic acid as the viscous component, and by the hydrolysis of pure hyaluronic acid into its reducing components. In pneumococci the enzyme was demonstrated in all types and in all strains tested, including smooth and rough forms of Types I, II, III, and VI. In hemolytic streptococci the enzyme from strain H44, group A, reported previously, was further investigated. In this strain, as well as in other hemolytic streptococci containing the enzyme, great variability of the enzyme concentration was found. Furthermore, the enzyme proved to be very labile, giving in the viscosimetric measurements a typical stoppage of the activity initially present. In 13 out of 14 other strains of group A organisms investigated, no enzyme was demonstrable, but the variation in activity in the enzyme-active strains renders the negative findings inconclusive. A very active enzyme, though of great variability, was found in one group C strain. The enzyme was prepared from the leech in confirmation of the work of Claude. The enzyme from testis showed a maximum at pH 4.4 in contrast to the optimum of 5.8 in pneumococcal, streptococcal, and Cl. welchii preparations. The pH curve of the testis enzyme indicated, however, a second optimum coinciding with that of the bacterial enzymes. The hydrolysis further indicated a break at about 50 per cent hydrolysis, indicating primarily the hydrolysis down to aldobionic acid units. The depolymerizing action of testis enzyme is more marked than that of pneumococcal enzyme. The results have been interpreted as due to the presence of two enzymes, one attacking the long chain molecule, the other hydrolyzing the aldobionic acid formed. The enzyme was further prepared from beef spleen. Here the hydrolysis of beta

  16. Controlling the conductivity and stability of azoles: Proton and hydroxide exchange functionalities

    NASA Astrophysics Data System (ADS)

    Chaloux, Brian Leonard

    molecules, the extent of 1H-tetrazole dissociation in PS-Tet (~0.02--0.08%) was found to be the primary factor limiting proton conductivity, suggesting that further doping should substantially increase proton conductivity. Although small molecules can provide this doping, polymer--polymer doped blends were investigated to prevent evaporation and leeching of dopant over time. It was found that the pKa and pKb of the 1 H-azoles do not directly have an effect on proton conductivity, but instead play a large role with respect to dopants. Polymers containing low pKa or pKb azoles (e.g. 1H-tetrazole, 1 H-imidazoline) were more easily doped by residual acceptors / donors (e.g. water, acetic acid), leading to high conductivity compared to counterparts with high pKa and pKb (e.g. triazole). Doping PS-Tet with poly(styrenesulfonic acid) lead to conductivities higher by an order of magnitude than those in undoped PS-Tet, but which originated from water of hydration associated with the strong acid. Although acidic PS-Tet and alkaline PS-ImH2 might represent an ideal combination of 1H-azoles to improve mobile proton density, the presence of strongly interacting, residual small molecules (e.g. water, acetic acid) prevented full association of tetrazole and imidazoline moieties in their blends. Finally, N,N'-symmetrically disubstituted imidazoliums with bulky alkyl substitutents were synthesized to determine how substituents and substitution patterns improve alkaline stability of these species. Although literature often cite rates of reaction (and thus stability) as being trivially linked to orbital energies, it was found that stability in practice was more strongly correlated with steric bulk of the imidazolium substituents, consistent with traditional chemical intuition. Both isopropyl and neopentyl groups significantly slowed degradation compared to benzyltrimethylammonium (a control compound), with substitution at the N and N' positions improving stability more significantly than

  17. Closure of Tethys and early stages of Himalayan evolution: constraints from the detrital record, Ladakh, India

    NASA Astrophysics Data System (ADS)

    Jenks, D.; Najman, Y.; Godin, L.; Parrish, R.; Horstwood, M.; Green, O.; Bown, P.; Garzanti, E.; Willems, H.

    2009-04-01

    detrital zircons allows discrimination between Asian provenance (dominated by Mesozoic grains from the Trans-Himalayan arc) and Indian provenance (characterized by Precambrian grains and an absence of Mesozoic grains). Our data from the Kong and Chulung La Formations shows a primary provenance from the Asian plate (arc derived), with dominant grain populations between 55-70 Ma and 90-100 Ma, and a subordinate population of Precambrian grains suggesting an origin on either the Indian (High or Tethyan Himalaya) or Asian (Lhasa Block) plate. Thus collision is constrained by arrival of Asian detritus on the Indian plate during SBZ9-10, 53-50.5 Ma. Our results and identification of first arrival of Asian material on the Indian plate at 53-50.5 Ma 1) conflicts with the recent view that the commonly quoted 50 Ma collision was between the Indian plate and a small intra-oceanic arc [4] rather than Asia and 2) correlates with data from analogous sediments along strike in Southern Tibet [12,13], eastern Himalaya, implying collision was synchronous along a large portion of the Himalayas. In addition, our new ages from the Trans-Himalayan arc contribute to the existing database which shows a very low proportion of grains dated between 80-90 Ma. This has been interpreted by previous workers as an expression of a reduction in magmatic activity around this time, due to a period of "flat subduction" of the Neo-Tethyan oceanic slab followed by slab roll back and a more vigorous period of magmatism [14]. [1] Jaeger, J. J., Courtillot, V., and Tapponnier, P., 1989, Geology, 17 (4), 316-319. [2] Leech, M. L., Singh, S., Jain, A. K., Klemperer, S. L., Manickavasagam, R. M., 2005, Earth and Planetary Science Letters, 234, 83-97. [3] Klootwijk, C. T., Gee, J. S., Peirce, J. W., Smith, G. M., and McFadden, P. L., 1992, Geology, 20 (5), 395-398. [4] Aitchison, J. C., Ali, J. R., and Davis, A. M., 2007,Journal of Geophysical Research, 112 B05423, doi:10.1029/2006JB004706,. [5] Searle, M., Corfield