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Sample records for leeches

  1. [Medicinal leeches].

    PubMed

    Massart, D; Sohawon, S; Noordally, O

    2009-01-01

    Leeches are hermaphroditic and hematophagous annelids. One important medical species, Hirudo medicinalis, comes from hirudiniculture of fresh water pools. Thanks to their three mandibles with some 300 teeth on their anterior muscular sucker, they easily grab to tissues and by secreting their saliva containing numerous powerful enzymes, such as hyaluronidase, collagenase and inhibitors of platelet aggregation and coagulation, like hirudin, allow blood sucking. Once they are full of blood (up to 15 g of blood), they detach themselves from their prey. Used ever since the 18th Egyptian Dynasty, leeches became famous during the first part of the XIXth century, thanks to a French physician, François Joseph Victor Broussais, known to his adversaries as the "vampire of medicine" for treating various conditions such as phlebotomy, laryngitis, ocular problems, obesity, mental disorders, etc. Overfishing, therapeutic failures and most particularly, the emergence of hygiene, brought the decline of living leeches. In 1884, an extract of leeches was obtained--hirudin and henceforth used. Nowadays, leeches are still used in microsurgery to enhance the venous circulation in finger reimplantation or skin flap transposition. Hirudin is synthesized through recombinant DNA technology and molecules such as lepirudin and desirudin are available on the market as anticoagulant.

  2. 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...

  3. 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

  4. [Medicinal leeches and hirudotherapy].

    PubMed

    Gödekmerdan, Ahmet; Arusan, Suat; Bayar, Batu; Sağlam, Naim

    2011-01-01

    Leeches have been used in the treatment of certain diseases since ancient times. There are a few species of medicinal leeches. However, H. medicinalis and H. verbana are known in Turkey. Currently, Turkey is one of the world's most important leech-exporting countries. Secretion of the salivary glands of medical leeches contains more than 100 bioactive substances. These secretions include vasodilators, bacteriostatic, analgesic, anti-inflammatory and anticoagulants, anti-edematous, which eliminate microcirculatory disorders, restore the damaged vascular permeability of tissues and organs, eliminate hypoxia, reduce blood pressure, increase immune system activity, resolving the cause of pain and improve the bioenergetic status of the organism. U.S. Food and Drug Administration (Food and Drug Authority of USA-FDA) have allowed the sale of leeches in this country, the use for plastic surgery, the general purposes and microsurgery in 2004. Turkey is the richest source in terms of the medical leech. Better evaluation of this valuable commodity and more effective use of hirudotherapy in modern medical practice as supportive treatment is very important.

  5. 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

  6. 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...

  7. Medicinal leech therapy (hirudotherapy): a brief overview.

    PubMed

    Singh, Amrit Pal

    2010-11-01

    Hirudotherapy is a treatment using medicinal leeches. Hirudo medicinali, have been used to treat patients for centuries. In the past, leeches have proved to be an effective treatment for a number of conditions including battle wound treatment. Currently leeches may be used to assist in the treatment of abscesses, arthritis, glaucoma, myasthenia gravis, thrombosis and some venous disorders. Medical leeches may also be used in plastic surgery and in some blood circulatory problems. During feeding, leeches secrete a complex mixture of different biologically and pharmacologically active substances into the wound. Hirudin is the prominent constituent of leech saliva. It is sometimes used to describe all the active constituents in the leech saliva. This paper outlines the potential use of leech therapy in current medical care in India.

  8. Aeromonas species isolated from medicinal leeches.

    PubMed

    Mackay, D R; Manders, E K; Saggers, G C; Banducci, D R; Prinsloo, J; Klugman, K

    1999-03-01

    Aeromonas hydrophila infections are a recognized complication of the use of medicinal leeches. The authors performed an experiment designed to find a safe and practical way to sterilize the leech gut of pathogenic organisms. Leeches were incubated for a 12-hour period in solutions of antibiotic effective against A. hydrophila. The incubations in the antibiotic solutions failed to eradicate pathogenic bacteria from the gut of the leeches. The authors examined cultures of bacteria isolated from the guts of the commonly used Hirudo medicinalis (European leech) and found a wide variety of pathogenic organisms. A. hydrophila is widely believed to be the most common enteric pathogen, but the authors found A. sobria more frequently in their experiment. They also cultured the guts of the leech H. michaelseni recently used clinically in South Africa. A. caviae was the most common pathogen encountered in these leeches. A. caviae and A. sobria cause a spectra of disease similar to A. hydrophila. The authors endorse the current recommendation that all patients who have leech therapy for congested flaps or replants receive broad-spectrum prophylactic antibiotics. This appears to be the safest and simplest way to prevent leech-related infections.

  9. Pruritis and palpable purpura from leeches in the Australian Rainforest

    PubMed Central

    Seiverling, Elizabeth V.; Khalsa, Amrit; Ahrns, Hadjh T.

    2014-01-01

    Leeches are prevalent in the Australian Rainforest. We report two cases of leech bites resulting in pruritis and palpable purpura. The dermatologic sequelae of leech bites, differential diagnosis of pruritic palpable purpura, leech bite treatment, prevention, and complications are reviewed. PMID:26839767

  10. [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. PMID:25264804

  11. [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.

  12. 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... Winnibigoshish and Pokegama dams, Leech River between outlet of Leech Lake and Mississippi River, and...

  13. 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... Winnibigoshish and Pokegama dams, Leech River between outlet of Leech Lake and Mississippi River, and...

  14. Findings of Bone Scintigraphy After Leech Theraphy

    PubMed Central

    Özyurt, Sinem; Koca, Gökhan; Demirel, Koray; Baskın, Aylin; Korkmaz, Meliha

    2014-01-01

    In this case report, we present a 70 year old female patient who had recieved Leech therapy (hirudotherapy) on her leg without informing referring physician. In dynamic bone scintigraphy there was increased perfusion and hyperemia in her left ankle and leg, also in late static images moderate increased uptake was seen in soft tissue region and at the fracture site of ankle. We learned that she had Leech therapy applied on her leg, which could explain the increased perfusion and hyperemia in dynamic and blood pool phases of bone scintigraphy because of Leech therapy’s dilatory effects on superficial veins. Leech therapy may lead to an increase in perfusion and hyperemia in blood pool phase of bone scintigraphy, which may cause confusion in differential diagnosis. To our best knowledge this report is the first case that shows the scintigraphic findigs after Leech therapy. Conflict of interest:None declared. PMID:24653932

  15. The Dynamics of Group Formation Among Leeches

    PubMed Central

    Bisson, Giacomo; Bianconi, Ginestra; Torre, Vincent

    2012-01-01

    Leeches exploring a new environment continuously meet each other and merge in temporary groups. After 2–3 h, leeches become attracted to each other eventually forming a large and stable group. When their number is reduced, leeches remain solitary, behaving independently. Group formation is facilitated by body injection of serotonin (5-HT) and the level of endogenous 5-HT is elevated in leeches forming a large group. In contrast, intravenous injection of 5-HT antagonists prevented injected leeches from joining a large group of conspecifics. When sensilla near the head were ablated or the supraesophageal ganglion disconnected, leeches remained solitary, but explored the environment swimming and crawling. These results suggest that group formation is initiated by a release of 5-HT triggered by sensilla stimulation and its dynamics can be explained by the establishment of a reinforcement dynamics, as observed during human group formation. As 5-HT affects social interactions also in humans, group formation in leeches and humans share a similar dynamics and hormonal control. PMID:22629247

  16. Heart Motorneuron Dynamics of Leeches

    NASA Astrophysics Data System (ADS)

    Buono, Pietro-Luciano; Palacios, Antonio

    2003-08-01

    The heartbeat of the medicinal leech consists of two intricate patterns of oscillatory behavior, which are driven by two lateral arrays of motorneurons. On one side of the animal the motorneurons oscillate synchronously, while on the other side they produce a peristaltic wave of oscillations. Then every 20 heartbeats, approximately, the two sides alternate their activity. These two rhythms, including the transitions between them, are known to be initiated by a Central Pattern Generator (CPG) network of neurons. The translation mechanism from CPG dynamics to motorneuron activity, however, is not well understood. In this work, we use symmetric systems of differential equations, accompanied with computational simulations, to investigate such mechanism.

  17. [Leeches, today and yesterday present parasites].

    PubMed

    Vera, Cristián; Blu, Antonieta; Torres, Marisa

    2005-03-01

    Leeches are flattened annelids or segmented worms that live in still, warm waters of the pond or in land. They feed of blood or body fluids. Medicinal leeches (Hirudo medicinalis) have been used in medicine for thousands of years to treat a wide range of ailments. Nowadays, leeches are used successfully for only a few conditions, notably in the field of reconstructive or microsurgery, to salvage tissue flaps and skin grafts whose viability is threatened by venous congestion. However, it is also important to keep it in mind as a differential diagnosis in some circumstances. This review pretends to give an actualize view of a subject that is a part of medical history.

  18. Medicinal leech therapy in pain syndromes: a narrative review.

    PubMed

    Koeppen, Detlev; Aurich, Michael; Rampp, Thomas

    2014-03-01

    Medicinal leech therapy is used in a variety of conditions; most of which have pain as a major symptom. Its mode of action relies on the injection of leech saliva into patients' tissues during the process of blood withdrawal. Leech saliva contains active ingredients with anti-inflammatory, thrombolytic, anti-coagulant and blood- and lymph-circulation enhancing properties. A specific analgesic substance within the leech saliva is yet to be identified. Pain relief from leech therapy is rapid, effective and long-lasting in many conditions. This review compiles studies and case reports that provide clinical evidence for leech therapy's analgesic effects.

  19. Medicinal leech therapy and Aeromonas spp. infection.

    PubMed

    Verriere, B; Sabatier, B; Carbonnelle, E; Mainardi, J L; Prognon, P; Whitaker, I; Lantieri, L; Hivelin, M

    2016-06-01

    While the use of medicinal leech therapy (MLT) in reconstructive and orthopaedic surgery is widely described, post-operative complications related to leeches remain a major concern. Aeromonas spp. strains are involved in the majority of reported cases. As surgical success rate is directly impacted, an adapted antibiotic prophylaxis should be instituted in order to minimize these complications. We assessed pharmaceutical process, microbiological control and related infections in order to provide data and choose the appropriate antibiotherapy for patients requiring MLT. We report a clinical and microbiological study over a 24-month period. Clinical data were collected from patients' database, and microbiological analysis both on leeches' tank water and crushed leeches were performed to characterize isolated strains and their susceptibility to antibiotics. A total of 595 leeches were used to treat 28 patients (12 in plastic surgery and 16 in orthopaedic surgery), and three documented cases of post-operative infections were reported. Aeromonas spp. isolates yielded from 62 % of analyzed batches (75 % of Aeromonas veronii). Eighteen Aeromonas spp. isolates yielded from 23 water samples and three crushed leeches. Isolates were similar in tank and crushed leeches. Strains were susceptible to fluoroquinolones, sulfamethoxazole/trimethoprim, aminosides, and third-generation cephalosporins but resistant to amoxicillin/clavulanic acid and second-generation cephalosporins. According to collected data, routine tank water microbiological analyses are mandatory in order to identify leeches' batches containing resistant strains and to discard them. In this context, the surgeon is able to select an appropriated antibiotic prophylaxis in order to avoid MLT associated serious post-operative complications.

  20. Reach the Leech: An Unusual Cause of Hematuria.

    PubMed

    Mansoor, Sahibzada Nasir; Anwar, Zahid; Sheen, Salman Najam

    2016-02-01

    Leeches are found in fresh water as well as moist marshy tropical areas. Orifical Hirudiniasis is the presence of leech in natural human orifices. Leech have been reported in nose, oropharynx, vagina, rectum and bladder but leech per urethra is very rare. We report a case of leech in urethra causing hematuria and bleeding disorder in the form of epistaxis and impaired clotting profile after use of stream water for ablution. The case was diagnosed after a prolonged diagnostic dilemma. Asingle alive leech was recovered from the urethra after ten days with the help of forceps. The hematuria and epistaxis gradually improved over next 48 hours and the patient became asymptomatic. Natives of leech infested areas should be advised to avoid swimming in fresh water and desist from drinking and using stream water without inspection for leeches. PMID:26876408

  1. From bloodletting to bioconcentration: Science resurrects the leech

    SciTech Connect

    Gorvalski, M.

    1990-07-01

    Leeches are being used by environmental chemists at the Westwater Research Center at the University of British Columbia to measure the contamination levels of local rivers. As the chemical Agent Orange is broken down, chlorinated phenols are released and absorbed by the leeches. The levels of the chlorophenols are too small to be detected by conventional methods, so the leeches are used as monitoring organisms. The leeches are being tested to see if they could be used to monitor other pollutants as well.

  2. Melena revealing a nasopharyngeal leech: a paediatric case.

    PubMed

    El Koraichi, Alae; Ayoubi, Ali; Benjelloun, Mohamed Y; Bentalha, A; El Kettani, Salma E

    2014-03-01

    Leech infestation occurs after swimming or ingestion of freshwater, especially in rural areas. Symptoms are different depending on the binding site of the leech. At the nasopharynx, it is mainly responsible for epistaxis. We report a case of an unknown pharyngeal location of a leech in a three year-old girl responsible for melena and leading to a severe anaemia. PMID:24630513

  3. Aeromonas hydrophila infection associated with the use of medicinal leeches.

    PubMed Central

    Snower, D P; Ruef, C; Kuritza, A P; Edberg, S C

    1989-01-01

    The use of medicinal leeches (Hiruda medicinalis) is becoming more common after plastic surgery to control venous congestion of skin grafts. We describe a patient with Aeromonas hydrophila infection whose graft was treated with medicinal leeches. The infection required systemic antibiotic therapy. A. hydrophila is the predominant bacterial flora in the gut of the leech, where it plays an essential role for the animal in the digestion of blood. The potential for A. hydrophila wound infection, and appropriate antibiotic prophylaxis of the leech or patient, should be considered when medicinal leeches are used. Images PMID:2666448

  4. A simple method for the control of medicinal leeches.

    PubMed

    Granzow, Jay W; Armstrong, Milton B; Panthaki, Zubin J

    2004-08-01

    The medicinal leech, Hirudo medicinalis, has been widely used in the salvage of microvascular free flaps. Numerous publications have detailed the biology, use, benefits, and risks of leech therapy. One reported significant risk is the risk of leech movement or migration from the surgical site, possibly into body orifices or even deeper into the wound itself. The authors report a simple method of limiting the movement of medicinal leeches from the surgical site, namely, affixing one end of a surgical suture to the leech and tying the free end to a firm object or dressing. This simple method limits the potential range of movement of the leech and reduces the risk of leech migration to unwanted areas.

  5. Building exploration with leeches Hirudo verbana.

    PubMed

    Adamatzky, Andrew; Sirakoulis, Georgios Ch

    2015-08-01

    Safe evacuation of people from building and outdoor environments, and search and rescue operations, always will remain actual in course of all socio-technological developments. Modern facilities offer a range of automated systems to guide residents towards emergency exists. The systems are assumed to be infallible. But what if they fail? How occupants not familiar with a building layout will be looking for exits in case of very limited visibility where tactile sensing is the only way to assess the environment? Analogous models of human behaviour, and socio-dynamics in general, are provided to be fruitful ways to explore alternative, or would-be scenarios. Crowd, or a single person, dynamics could be imitated using particle systems, reaction-diffusion chemical medium, electro-magnetic fields, or social insects. Each type of analogous model offer unique insights on behavioural patterns of natural systems in constrained geometries. In this particular paper we have chosen leeches to analyse patterns of exploration. Reasons are two-fold. First, when deprived from other stimuli leeches change their behavioural modes in an automated regime in response to mechanical stimulation. Therefore leeches can give us invaluable information on how human beings might behave under stress and limited visibility. Second, leeches are ideal blueprints of future soft-bodied rescue robots. Leeches have modular nervous circuitry with a rich behavioral spectrum. Leeches are multi-functional, fault-tolerant with autonomous inter-segment coordination and adaptive decision-making. We aim to answer the question: how efficiently a real building can be explored and whether there any dependencies on the pathways of exploration and geometrical complexity of the building. In our case studies we use templates made on the floor plan of real building.

  6. The contemporary use of the medicinal leech.

    PubMed

    Bunker, T D

    1981-03-01

    Over 100 000 patients with head injuries are admitted to General Hospitals every year in Britain (Jennet, 1978). A fair proportion of these have periorbital haematoma. Evacuation of the haematoma using a leech is a painless procedure which can be carried out by a nurse. It allows the patient to open his eye and see immediately, relieving him of discomfort and disfigurement. It allows the doctor or nurse to open the eye easily and painlessly for observation of pupil size and reaction. Leeches are cheap and very easily kept. PMID:7263055

  7. Persistence of leech repellents on cloth.

    PubMed

    Nath, D R; Das, N G; Das, S C

    1993-05-01

    Trials on persistence of repellent properties of N, N-diethyl phenyl acetamide (DEPA), N,N-diethyl-m-toluamide (DEET), 3acetyl2(2-6-dimethyl-5-heptenyl)oxazolidine(Citronyl) , dimethyl phthalate (DMP) and N-benzoyl piperidine (NBP) on cloth were conducted against land leeches in evergreen rain and deciduous forests of Assam. Results obtained were compared with volatile oil of Zanthoxylum armatum DC. syn. Z. alatum Roxb (Timur) to evaluate its efficacy as leech repellent. DEPA and DEET were found to be the best. Timur oil was at par with Citronyl and exhibited better results than DMP and NBP.

  8. 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

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

    PubMed

    Kruger, Natasha; Du Preez, Louis

    2015-04-01

    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.

  10. Nurses' experiences of leech therapy in plastic and reconstructive surgery.

    PubMed

    Reynolds, Alison; OBoyle, Colm

    2016-07-14

    The aim of this study was to explore nurses' experience of using leech therapy. Leech therapy is useful in promoting revascularisation of skin grafts. Nurse disquiet in their role as leech therapists has been noted. This study explored the experience of Irish nurses. A qualitative design with an interview schedule was used to learn about emotional and practical clinical experiences. Interviews were carried out with seven nurses working with leeches in reconstructive surgery in 2013. These interviews were coded and explored for themes. Results revealed that many nurses feel aversion to the use of leeches. This may be associated with the use of a parasitic organism as treatment in conflict with the nurse's role in cross infection. It was also found that management of a nurse's own and patient's emotional responses is required. In conclusion, preparation for the role of leech therapy beyond the purely practical is necessary, and should explore affective responses of the practitioner and patients. PMID:27409780

  11. New gammaproteobacteria associated with blood-feeding leeches and a broad phylogenetic analysis of leech endosymbionts.

    PubMed

    Perkins, Susan L; Budinoff, Rebecca B; Siddall, Mark E

    2005-09-01

    Many monophagous animals have coevolutionary relationships with bacteria that provide unavailable nutrients to the host. Frequently, these microbial partners are vertically inherited and reside in specialized structures or tissues. Here we report three new lineages of bacterial symbionts of blood-feeding leeches, one from the giant Amazonian leech, Haementeria ghilianii, and two others from Placobdelloides species. These hosts each possess a different mycetome or esophageal organ morphology where the bacterial cells are located. DNA sequencing of the bacterial 16S rRNA genes and fluorescent in situ hybridization placed these symbionts in two separate clades in the class Gammaproteobacteria. We also conducted a broad phylogenetic analysis of the herein-reported DNA sequences as well as others from bacterial symbionts reported elsewhere in the literature, including alphaproteobacterial symbionts from the leech genus Placobdella as well as Aeromonas veronii from the medicinal leech, Hirudo medicinalis, and a Rickettsia sp. detected in Hemiclepsis marginata. Combined, these results indicate that blood-feeding leeches have forged bacterial partnerships at least five times during their evolutionary history.

  12. Helobdella (leech): a model for developmental studies.

    PubMed

    Weisblat, David A; Kuo, Dian-Han

    2009-04-01

    Helobdella is a genus of freshwater leeches, several species of which have been used for developmental studies since the 1970s. Helobdella embryos have been used for cell-lineage tracing and dye-mediated photoablation, and they have also been very useful for studies in cellular neurobiology. In this article, we discuss the reasons that Helobdella is used for studying development and some of the questions that are addressed through the use of this organism. PMID:20147121

  13. Discontinuous locomotion and prey sensing in the leech.

    PubMed

    Harley, Cynthia M; Rossi, Matthew; Cienfuegos, Javier; Wagenaar, Daniel

    2013-05-15

    The medicinal leech, Hirudo verbana, is an aquatic predator that utilizes water waves to locate its prey. However, to reach their prey, the leeches must move within the same water that they are using to sense prey. This requires that they either move ballistically towards a pre-determined prey location or that they account for their self-movement and continually track prey. We found that leeches do not localize prey ballistically. Instead, they require continual sensory information to track their prey. Indeed, in the event that the prey moves, leeches will approach the prey's new location. While leeches need to continually sense water disturbances to update their percept of prey location, their own behavior is discontinuous--prey involves switching between swimming, crawling and non-locomoting. Each of these behaviors may allow for different sensory capabilities and may require different sensory filters. Here, we examined the sensory capabilities of leeches during each of these behaviors. We found that while one could expect the non-locomoting phases to direct subsequent behaviors, crawling phases were more effective than non-locomotor phases for providing direction. During crawling bouts, leeches adjusted their heading so as to become more directed towards the stimulus. This was not observed during swimming. Furthermore, in the presence of prey-like stimuli, leeches crawled more often and for longer periods of time.

  14. Recommendations for the Use of Leeches in Reconstructive Plastic Surgery

    PubMed Central

    2014-01-01

    A written informed consent should be obtained from the patient before hirudotherapy is initiated. The patients should be treated each day of leech therapy with anti-Aeromonas antibiotics. Leeches should be applied on the darker spots of the reattached body parts or flaps. Usually 1–10 leeches are used for each treatment, while at the beginning, the patient might need two or more treatments per day. Leech therapy is used until venous capillary return is established across the wound border by angiogenesis. Usually the treatment with leeches lasts for 2–6 days. Hematologic evaluations should be performed every 4 hrs and the patient has to receive blood transfusions when the hemoglobin level is lower than 8 g/dL. Signs of regional lymphadenitis, slight swelling, and pain of regional lymph nodes on the side of leech application and subfebrile temperature can occur. Contraindications related to hirudotherapy include arterial insufficiency, hemophilia, hemorrhagic diathesis, hematological malignancies, anemia, hypotension, and sepsis. Leech therapy is not recommended in pregnancy and lactation and in patients with an unstable medical status, history of allergy to leeches or severe allergic diathesis, and disposition to keloid scar formation, as well as in those using anticoagulants and immunosuppressants. PMID:24653746

  15. Salivary transcriptome of the North American medicinal leech, Macrobdella decora.

    PubMed

    Min, Gi-Sik; Sarkar, Indra Neil; Siddall, Mark E

    2010-12-01

    A variety of bioactive proteins from medicinal leeches, like species of Hirudo , have been characterized and evaluated for their potential therapeutic biomedical properties. However, there has not previously been a comprehensive attempt to fully characterize the salivary transcriptome of a medicinal leech that would allow a clearer understanding of the suite of polypeptides employed by these sanguivorous annelids and provide insights regarding their evolutionary origins. An Expressed Sequence Tag (EST) library-based analysis of the salivary transcriptome of the North American medicinal leech, Macrobdella decora, reveals a complex cocktail of anticoagulants and other bioactive secreted proteins not previously known to exist in a single leech. Transcripts were identified that correspond to each of saratin, bdellin, destabilase, hirudin, decorsin, endoglucoronidase, antistatin, and eglin, as well as to other previously uncharacterized predicted serine protease inhibitors, lectoxin-like c-type lectins, ficolin, disintegrins and histidine-rich proteins. This work provides a lens into the richness of bioactive polypeptides that are associated with sanguivory. In the context of a well-characterized molecular phylogeny of leeches, the results allow for preliminary evaluation of the relative evolutionary origins and historical conservation of leech salivary components. The goal of identifying evolutionarily significant residues associated with biomedically significant phenomena implies continued insights from a broader sampling of blood-feeding leech salivary transcriptomes.

  16. Developmental biology of the leech Helobdella.

    PubMed

    Weisblat, David A; Kuo, Dian-Han

    2014-01-01

    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

  17. 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

  18. 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.

  19. Medicinal leeches used to salvage a traumatic nasal flap.

    PubMed

    Mortenson, B W; Dawson, K H; Murakami, C

    1998-12-01

    We report a case in which medicinal leeches (Hirudo medicinalis) were used to rescue a traumatic nasal flap from venous congestion and loss. A healthy 18-year-old had a bicycling accident and, in addition to other facial injuries, presented with a complex full thickness nasal laceration. After he had been resuscitated and the flap sutured, he was treated with two leeches four times a day for 48 h. His recovery was satisfactory and uncomplicated. Oral and maxillofacial surgeons should be familiar with the use of leeches, as they have a small but occasionally important role in the management of both traumatic and reconstructive flaps.

  20. Flap infection associated with medicinal leeches in reconstructive surgery: two new drug-resistant organisms.

    PubMed

    Bibbo, Christopher; Fritsche, Thomas; Stemper, Mary; Hall, Matthew

    2013-09-01

    The use of medicinal leeches in reconstructive surgery has proven value for the salvage of flaps with venous congestion but is associated with a risk of leech-acquired infection. The most common leech-associated organism is Aeromonas hydrophila, which antibiotic prophylaxis is typically directed against. The authors describe two new multidrug-resistant organisms acquired from medicinal leech therapy that resulted in flap infection. The evaluation of suspected leech-borne infection and management protocol for this leech-acquired resistant multi-organism infection is presented.

  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. 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).

  3. Proton magnetic resonance spectroscopy of leech muscle and nervous system.

    PubMed

    Petroff, O A; Hogan, E; Johansen, J; Kleinhaus, A L

    1987-01-01

    1. Proton nuclear magnetic resonance spectroscopy (1H NMR) was used to measure the major intracellular metabolites in perchloric acid extracts of the Macrobdella decora muscle and nervous systems and the Oryctolagus cuniculus cerebrum. 2. Acetate, alanine, choline, glutamate, inositol, and lactate were assigned in the spectrum of leech ventral cord, leech muscle, and rabbit cerebrum. 3. Hirudonine and propionate were clearly observed only in the spectrum of leech muscle. 4. Creatine, N-acetyl aspartate, gamma aminobutyric acid, aspartate, and taurine, distinctive components of spectra of the mammalian cerebrum, were not seen in the invertebrate spectra. 5. 1H NMR spectroscopy provides a simple and rapid means of characterizing the major organic metabolites found in leech muscle and nervous tissues.

  4. A systematic overview of the medicinal importance of sanguivorous leeches.

    PubMed

    Zaidi, S M Abbas; Jameel, S S; Zaman, F; Jilani, Shazia; Sultana, A; Khan, Shariq A

    2011-03-01

    Leeches are a class of segmented invertebrates, known for their blood-feeding habits and used in phlebotomy to treat various ailments since antiquity. In Europe, medicinal leeches have recently been rediscovered and are used by maxillofacial and other microsurgeons to aid salvage of compromised venous engorged tissue and amputations, such as digits, ears, and nasal tips. Because of their important salivary components, blood-sucking (sanguivorous) leeches, such as Hirudo medicinalis and related species, have engendered great interest from pharmaceutical companies searching for anticoagulants to prevent blood clotting during microsurgeries. Scientific research reveals that the beneficial effects of leeching, in addition to decongestion, include injection of a cocktail of several medicinally useful bioactive molecules present in their saliva. Owing to its therapeutic potential, the research is continuing as many new salivary compounds are being isolated and synthesized. PMID:21438647

  5. 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 ...

  6. A systematic overview of the medicinal importance of sanguivorous leeches.

    PubMed

    Zaidi, S M Abbas; Jameel, S S; Zaman, F; Jilani, Shazia; Sultana, A; Khan, Shariq A

    2011-03-01

    Leeches are a class of segmented invertebrates, known for their blood-feeding habits and used in phlebotomy to treat various ailments since antiquity. In Europe, medicinal leeches have recently been rediscovered and are used by maxillofacial and other microsurgeons to aid salvage of compromised venous engorged tissue and amputations, such as digits, ears, and nasal tips. Because of their important salivary components, blood-sucking (sanguivorous) leeches, such as Hirudo medicinalis and related species, have engendered great interest from pharmaceutical companies searching for anticoagulants to prevent blood clotting during microsurgeries. Scientific research reveals that the beneficial effects of leeching, in addition to decongestion, include injection of a cocktail of several medicinally useful bioactive molecules present in their saliva. Owing to its therapeutic potential, the research is continuing as many new salivary compounds are being isolated and synthesized.

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

    PubMed Central

    Kuo, Dian-Han

    2011-01-01

    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. PMID:21938507

  8. 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.

  9. Statistical characterization of social interactions and collective behavior in medicinal leeches.

    PubMed

    Bisson, Giacomo; Torre, Vincent

    2011-07-01

    In the present study we analyzed the behavior and interactions among leeches in the same observation tank. Colored beads were glued onto their skin so that their behavior could be followed and quantified. When two or three leeches were present in the observation tank, they searched around for a maximum of 2 h and their motion and behavior were independent from those of their conspecifics. When the number of leeches in the tank was increased to 10, leeches were attracted to each other and exhibited episodes of highly correlated behavior. Solitary leeches injected with serotonin or dopamine increased the portion of time spent pseudoswimming and crawling, respectively. The behavior of three to five leeches injected with serotonin was not statistically independent, and leeches were attracted to their conspecifics and exhibited episodes of correlated behavior. Therefore, serotonin not only induces pseudoswimming in leeches but also promotes social interactions, characterized by a mutual attraction and by episodes of correlated/collective behavior.

  10. Novel role for Aeromonas jandaei as a digestive tract symbiont of the North American medicinal leech.

    PubMed

    Siddall, Mark E; Worthen, Paul L; Johnson, Matthew; Graf, Joerg

    2007-01-01

    The gut bacteria of the North American medicinal leech, Macrobdella decora, were characterized. Biochemical tests and DNA sequences indicated that Aeromonas jandaei is the dominant culturable symbiont in leeches from a broad geographic area. In this work we identified a new habitat for A. jandaei, and here we suggest that there is unexpected specificity between leeches and Aeromonas species.

  11. [Review on scientific connotation of leech processed under high temperature].

    PubMed

    Ma, Li; Ma, Lin; Wang, Shu-bin; Wang, Xuan; Yue, Lin

    2015-10-01

    Animal medicines mainly contain protein which was organic molecule with quaternary structure and had the property of thermal denaturation. When suffering from heat for a consistent time, the native conformation of protein would be destroyed. After denaturation the biological activity of protein will lose and some physicochemical and biochemical properties will be changed. Leech was a classical animal medicine in the views of traditional Chinese medicine (TCM) which had the functions of breaking stagnant and eliminating blood stasis. In the usage history, it was processed for a long time. No matter stir-frying leech with talc powder embodied in Chinese Pharmacopoeia or stir-baking with wine as a distinctive method in Beijing district, the process procedure was basically performed under high temperature. The purposes and intentions of process are mostly limited to technology conditions at specific historical period. In this article, based on existing processing procedure and its character of Leech, the changes of active components and pharmacological activities before and after processing under high temperature were summarized. The results demonstrate that the protein of leech would be denaturated; some active peptide such as hirudin were partly or totally destroyed; some toxic mineral elements, such as Pb, Hg, Cd, were decreased; at the same time, heating can promote some chemical components transforming into hypoxanthine which had the function of antihypertensive, antiasthmatic and antalgic. Consequently, after processed under high temperature, the purpose of decreasing toxicity and alleviating the strong property was achieved. Pharmacological changes of leech processed under high temperature were mainly manifested in the anticoagulant and antithrombotic activity, etc. Based on current processing research status about animal medicine leech, future research methods and directions on scientific connotation of leech processed under high temperature were put forward in

  12. [Review on scientific connotation of leech processed under high temperature].

    PubMed

    Ma, Li; Ma, Lin; Wang, Shu-bin; Wang, Xuan; Yue, Lin

    2015-10-01

    Animal medicines mainly contain protein which was organic molecule with quaternary structure and had the property of thermal denaturation. When suffering from heat for a consistent time, the native conformation of protein would be destroyed. After denaturation the biological activity of protein will lose and some physicochemical and biochemical properties will be changed. Leech was a classical animal medicine in the views of traditional Chinese medicine (TCM) which had the functions of breaking stagnant and eliminating blood stasis. In the usage history, it was processed for a long time. No matter stir-frying leech with talc powder embodied in Chinese Pharmacopoeia or stir-baking with wine as a distinctive method in Beijing district, the process procedure was basically performed under high temperature. The purposes and intentions of process are mostly limited to technology conditions at specific historical period. In this article, based on existing processing procedure and its character of Leech, the changes of active components and pharmacological activities before and after processing under high temperature were summarized. The results demonstrate that the protein of leech would be denaturated; some active peptide such as hirudin were partly or totally destroyed; some toxic mineral elements, such as Pb, Hg, Cd, were decreased; at the same time, heating can promote some chemical components transforming into hypoxanthine which had the function of antihypertensive, antiasthmatic and antalgic. Consequently, after processed under high temperature, the purpose of decreasing toxicity and alleviating the strong property was achieved. Pharmacological changes of leech processed under high temperature were mainly manifested in the anticoagulant and antithrombotic activity, etc. Based on current processing research status about animal medicine leech, future research methods and directions on scientific connotation of leech processed under high temperature were put forward in

  13. 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.

  14. 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

  15. Ecdysone receptor homologs from mollusks, leeches and a polychaete worm.

    PubMed

    Laguerre, Michel; Veenstra, Jan A

    2010-11-01

    The genomes of the mollusk Lottia gigantea, the leech Helobdella robusta and the polychaete worm Capitella teleta each have a gene encoding an ecdysone receptor homolog. Publicly available genomic and EST sequences also contain evidence for ecdysone receptors in the seahare Aplysia californica, the bobtail squid Euprymna scolopes and the medicinal leech Hirudo medicinalis. Three-dimensional models of the ligand binding domains of these predicted ecdysone receptor homologs suggest that each of them could potentially bind an ecdysone-related steroid. Thus, ecdysone receptors are not limited to arthropods and nematodes.

  16. Neural circuits controlling behavior and autonomic functions in medicinal leeches.

    PubMed

    Lamb, Damon G; Calabrese, Ronald L

    2011-09-28

    In the study of the neural circuits underlying behavior and autonomic functions, the stereotyped and accessible nervous system of medicinal leeches, Hirudo sp., has been particularly informative. These leeches express well-defined behaviors and autonomic movements which are amenable to investigation at the circuit and neuronal levels. In this review, we discuss some of the best understood of these movements and the circuits which underlie them, focusing on swimming, crawling and heartbeat. We also discuss the rudiments of decision-making: the selection between generally mutually exclusive behaviors at the neuronal level.

  17. Evaluation of performance characteristics of the medicinal leech (Hirudo medicinalis) for the treatment of venous congestion.

    PubMed

    Conforti, Michael L; Connor, Nadine P; Heisey, Dennis M; Hartig, Gregory K

    2002-01-01

    Medicinal leeches (Hirudo medicinalis) are a standard treatment for venous congestion, a complication that can occur after reconstructive surgery. If the cause of venous congestion cannot be surgically corrected, then medicinal leeches are used to temporarily increase perfusion levels and maintain physiologic requirements within the congested tissue. Leeches increase perfusion within congested tissue by actively drawing off blood as a bloodmeal. Furthermore, the leech bite continues to bleed and relieve congestion after detachment because of the anticoagulation effects of leech saliva left behind in the bite. In a porcine model, a 10 x 10 cm cutaneous flank flap was congested by clamping the venae comitantes. Four medicinal leeches were allowed to attach to the congested flap, and parameters of active feeding and passive bleeding after detachment were recorded. The average bloodmeal volume for the medicinal leeches was 2.45 ml. Average passive bleeding for the first 2 and 4 hours after leech detachment totaled 2.21 and 2.50 ml, respectively, with 90 percent of passive bleeding occurring within 5 hours after detachment. Laser Doppler imaging indicated that the spatial arrangement of surface perfusion increases were localized to a 1.6-cm-diameter circle around the leech head (bite) and corresponded well with the visual return of normal skin tones to the same area. This study provides a realistic and quantitative estimate of the spatial and volumetric characteristics of leech feeding and passive bleeding using a clinically relevant model of acute, severe congestion.

  18. A Leech Capable of Surviving Exposure to Extremely Low Temperatures

    PubMed Central

    Suzuki, Dai; Miyamoto, Tomoko; Kikawada, Takahiro; Watanabe, Manabu; Suzuki, Toru

    2014-01-01

    It is widely considered that most organisms cannot survive prolonged exposure to temperatures below 0°C, primarily because of the damage caused by the water in cells as it freezes. However, some organisms are capable of surviving extreme variations in environmental conditions. In the case of temperature, the ability to survive subzero temperatures is referred to as cryobiosis. We show that the ozobranchid leech, Ozobranchus jantseanus, a parasite of freshwater turtles, has a surprisingly high tolerance to freezing and thawing. This finding is particularly interesting because the leach can survive these temperatures without any acclimation period or pretreatment. Specifically, the leech survived exposure to super-low temperatures by storage in liquid nitrogen (−196°C) for 24 hours, as well as long-term storage at temperatures as low as −90°C for up to 32 months. The leech was also capable of enduring repeated freeze-thaw cycles in the temperature range 20°C to −100°C and then back to 20°C. The results demonstrated that the novel cryotolerance mechanisms employed by O. jantseanus enable the leech to withstand a wider range of temperatures than those reported previously for cryobiotic organisms. We anticipate that the mechanism for the observed tolerance to freezing and thawing in O. jantseanus will prove useful for future studies of cryopreservation. PMID:24466250

  19. A renin-like enzyme in the leech Theromyzon tessulatum.

    PubMed

    Salzet, M; Stefano, G

    1997-07-01

    We report on the biochemical isolation and characterization of a 32 kDa aspartyl protease from the leech Theromyzon tessulatum. Following a three step purification (gel permeation chromatography, pepstatin A-sepharose affinity column separation followed by reversed-phase HPLC) a renin-like enzyme was purified to homogeneity. The first 124 amino acid residues of the N-terminal part of the purified S-pyridylethylated leech renin exhibits a 26.5-35.5% sequence identity with that of mammals. The 20-81 region of leech renin exhibits a 80% sequence homology with the 175-232 region in mammals. This highly conserved region, which is also found in all aspartic proteases, possesses the aspartyl catalytic residue (D11TGSS). Leech renin hydrolyses at neutral pH and at 37 degrees C the Leu10-Leu11 bond of synthetic porcine angiotensinogen tetradecapeptide yielding the angiotensin I and the Leu11-Val12-Tyr13-Ser14 peptides, with a specific activity of 115 microg AI/min/mg (K[M] 22 microM; K[cat], 2.7). This hydrolysis is inhibited by pepstatin A (IC50: 4.6 microM). Moreover, this enzyme is found on a multiple hormone precursor of 19 kDa which exhibits a specific activity of 850 pmol AI/min/mg of renin. This is the first biochemical characterization of a renin-like enzyme in invertebrates and non-mammalian vertebrates.

  20. Leech Lake American Indian Foster Care Project 1978. Final Report.

    ERIC Educational Resources Information Center

    Walker and Associates, Inc., Minneapolis, Minn.

    In its second year the project continued to attempt to reduce the incidence of separation of Indian children from their families and to establish permanent planning for those children who were removed, thus improving the child welfare services to Minnesota Chippewa Indian children and families on the Leech Lake Reservation through direct foster…

  1. Scanning behavior in the medicinal leech Hirudo verbana.

    PubMed

    Harley, Cynthia M; Wagenaar, Daniel A

    2014-01-01

    While moving through their environment, medicinal leeches stop periodically and wave their head or body back and forth. This activity has been previously described as two separate behaviors: one called 'head movement' and another called 'body waving'. Here, we report that these behaviors exist on a continuum, and provide a detailed description of what we now call 'scanning'. Scanning-related behavior has been thought to be involved in orientation; its function has never before been assessed. While previous studies suggested an involvement of scanning in social behavior, or sucker placement, our behavioral studies indicate that scanning is involved in orienting the leech towards prey stimuli. When such stimuli are present, scanning behavior is used to re-orient the leech in the direction of a prey-like stimulus. Scanning, however, occurs whether or not prey is present, but in the presence of prey-like stimuli scanning becomes localized to the stimulus origin. Most likely, this behavior helps the leech to gain a more detailed picture of its prey target. The display of scanning, regardless of the presence or absence of prey stimuli, is suggestive of a behavior that is part of an internally driven motor program, which is not released by the presence of sensory stimuli. The data herein include first steps to understanding the neural mechanisms underlying this important behavior.

  2. Scanning Behavior in the Medicinal Leech Hirudo verbana

    PubMed Central

    Harley, Cynthia M.; Wagenaar, Daniel A.

    2014-01-01

    While moving through their environment, medicinal leeches stop periodically and wave their head or body back and forth. This activity has been previously described as two separate behaviors: one called ‘head movement’ and another called ‘body waving’. Here, we report that these behaviors exist on a continuum, and provide a detailed description of what we now call ‘scanning’. Scanning-related behavior has been thought to be involved in orientation; its function has never before been assessed. While previous studies suggested an involvement of scanning in social behavior, or sucker placement, our behavioral studies indicate that scanning is involved in orienting the leech towards prey stimuli. When such stimuli are present, scanning behavior is used to re-orient the leech in the direction of a prey-like stimulus. Scanning, however, occurs whether or not prey is present, but in the presence of prey-like stimuli scanning becomes localized to the stimulus origin. Most likely, this behavior helps the leech to gain a more detailed picture of its prey target. The display of scanning, regardless of the presence or absence of prey stimuli, is suggestive of a behavior that is part of an internally driven motor program, which is not released by the presence of sensory stimuli. The data herein include first steps to understanding the neural mechanisms underlying this important behavior. PMID:24465907

  3. Characterization of shed medicinal leech mucus reveals a diverse microbiota

    PubMed Central

    Ott, Brittany M.; Rickards, Allen; Gehrke, Lauren; Rio, Rita V. M.

    2015-01-01

    Microbial transmission through mucosal-mediated mechanisms is widespread throughout the animal kingdom. One example of this occurs with Hirudo verbana, the medicinal leech, where host attraction to shed conspecific mucus facilitates horizontal transmission of a predominant gut symbiont, the Gammaproteobacterium Aeromonas veronii. However, whether this mucus may harbor other bacteria has not been examined. Here, we characterize the microbiota of shed leech mucus through Illumina deep sequencing of the V3-V4 hypervariable region of the 16S rRNA gene. Additionally, Restriction Fragment Length Polymorphism (RFLP) typing with subsequent Sanger Sequencing of a 16S rRNA gene clone library provided qualitative confirmation of the microbial composition. Phylogenetic analyses of full-length 16S rRNA sequences were performed to examine microbial taxonomic distribution. Analyses using both technologies indicate the dominance of the Bacteroidetes and Proteobacteria phyla within the mucus microbiota. We determined the presence of other previously described leech symbionts, in addition to a number of putative novel leech-associated bacteria. A second predominant gut symbiont, the Rikenella-like bacteria, was also identified within mucus and exhibited similar population dynamics to A. veronii, suggesting persistence in syntrophy beyond the gut. Interestingly, the most abundant bacterial genus belonged to Pedobacter, which includes members capable of producing heparinase, an enzyme that degrades the anticoagulant, heparin. Additionally, bacteria associated with denitrification and sulfate cycling were observed, indicating an abundance of these anions within mucus, likely originating from the leech excretory system. A diverse microbiota harbored within shed mucus has significant potential implications for the evolution of microbiomes, including opportunities for gene transfer and utility in host capture of a diverse group of symbionts. PMID:25620963

  4. Incidence of the leech Actinobdella pediculata on freshwater drum in Lake Erie

    USGS Publications Warehouse

    Bur, Michael T.

    1994-01-01

    Actinobdella pediculata (Glossiphoniidae), a freshwater leech, was found attached to freshwater drum (Aplodinotus grunniens) from western Lake Erie during 1991 through 1993. The animal was first observed during routine examinations of freshwater drum collected in May 1991. The leeches were usually attached to the inside, lower portion of the opercula near the isthmus. Incidence of attachment increased with freshwater drum age and length. No noticeable adverse effects on the fish from attachment by the leech were noted.

  5. Structural characterization of a novel neuropeptide from the central nervous system of the leech Erpobdella octoculata. The leech osmoregulator factor.

    PubMed

    Salzet, M; Bulet, P; Weber, W M; Clauss, W; Verger-Bocquet, M; Malecha, J

    1996-03-22

    Purification of a material immunoreactive to an antiserum against the C-terminal part of the oxytocin (Pro-Leu-Gly-amide) and present in the central nervous system of the Pharyngobdellid leech Erpobdella octoculata was performed by reversed-phase high performance liquid chromatography combined with both enzyme-linked immunosorbent and dot immunobinding assays for oxytocin. The amino acid sequence of the purified peptide (Ile-Pro-Glu-Pro-Tyr-Val-Trp-Asp) was established by Edman degradation and confirmed by electrospray mass spectrometry measurement. When injected in leeches, purified or synthetic peptides exert an anti-diuretic effect, the most effective ranged between 10 pmol and 1 nmol. They provoked an uptake of water 1-2 h post-injection. Furthermore, electrophysiological experiments conducted in the leech Hirudo medicinalis revealed an inhibition of the potency of Na+ conductances of leech skin by this peptide. Immunocytochemical studies with an antiserum against synthetic oxytocin-like molecule provided the cytological basis for existence of a neuropeptide, since large amounts of immunoreactive neurons were detected in the central nervous systems of E. octoculata. The purified molecule is both different to peptides of the oxytocin/vasopressin family and is a novel neuropeptide in the animal kingdom. It was named the leech osmoregulator factor (LORF). An identification of the proteins immunoreactive to an antiserum against oxytocin performed at the level of both central nervous systems extracts and in vitro central nervous system-translated RNA products indicated that in the two cases, a single protein was detected. These proteins with a molecular masses of, respectively, approximately 34 kDa (homodimer of 17 kDa) for the central nervous systems extracts and approximately 19 kDa for in vitro central nervous system-translated RNA products were not recognized by the antiserum against MSEL- and VLDV-neurophysin (proteins associated to oxytocin and vasopressin

  6. Presence of the leech Placobdella costata in the south of the Iberian Peninsula.

    PubMed

    Romero, David; Duarte, Jesús; Narváez-Ledesma, Lucía; Farfán, Miguel Angel; Real, Raimundo

    2014-06-01

    Placobdella costata is a leech specific to freshwater turtle Emys orbicularis. Both genera are native to North America and have co-evolved and undergone dispersion through the Palearctic. The leech is present throughout the Mediterranean area, always associated with E. orbicularis. Their only known presence in the Iberian Peninsula is in the north and center of the peninsula. Here we present the first description of the leech in southern Spain (Andalusia) in association with a small fragmented population of fresh-water turtles in which E. orbicularis and Mauremys leprosa coexist. Unusually, the leech was found attached to the carapace of a male M. leprosa.

  7. Presence of the leech Placobdella costata in the south of the Iberian Peninsula.

    PubMed

    Romero, David; Duarte, Jesús; Narváez-Ledesma, Lucía; Farfán, Miguel Angel; Real, Raimundo

    2014-06-01

    Placobdella costata is a leech specific to freshwater turtle Emys orbicularis. Both genera are native to North America and have co-evolved and undergone dispersion through the Palearctic. The leech is present throughout the Mediterranean area, always associated with E. orbicularis. Their only known presence in the Iberian Peninsula is in the north and center of the peninsula. Here we present the first description of the leech in southern Spain (Andalusia) in association with a small fragmented population of fresh-water turtles in which E. orbicularis and Mauremys leprosa coexist. Unusually, the leech was found attached to the carapace of a male M. leprosa. PMID:24827095

  8. Bacterial symbioses of the medicinal leech Hirudo verbana.

    PubMed

    Nelson, Michael C; Graf, Joerg

    2012-01-01

    Gastrointestinal microbiomes play important roles in the health and nutrition of animals and humans. The medicinal leech, Hirudo verbana, serves as a powerful model for the study of microbial symbioses of the gut, due to its naturally limited microbiome compared with other popular models, the ability to cultivate the most abundant microbes, and genetically manipulate one of them, Aeromonas veronii. This review covers the relevance and application of leeches in modern medicine as well as recent discoveries detailing the nature of the gut microbiome. Additionally, the dual life-style of A. veronii allows one to do direct comparisons between colonization factors for beneficial and pathogenic associations, and relevant findings are detailed with respect to their role within the host and pathogenicity to other animals.

  9. Leeches as Sensor-bioindicators of River Contamination by PCBs

    PubMed Central

    Macova, Stanislava; Harustiakova, Danka; Kolarova, Jitka; Machova, Jana; Zlabek, Vladimir; Vykusova, Blanka; Randak, Tomas; Velisek, Josef; Poleszczuk, Gorzyslaw; Hajslova, Jana; Pulkrabova, Jana; Svobodova, Zdenka

    2009-01-01

    The aim of the study was to evaluate the use of leeches of the genus Erpobdella as a means of assessing polychlorinated biphenyl contamination of watercourses. The River Skalice, heavily contaminated with PCBs, was selected as a model. The source of contamination was a road gravel processing factory in Rožmitál pod Třemšínem from which an estimated 1 metric ton of PCBs leaked in 1986. Levels of PCB were measured in leeches collected between 1992 to 2003 from 11 sites covering about 50 km of the river (the first sampling site upstream to the source of contamination and 10 sites downstream). The PCB indicator congeners IUPA no. 28, 52, 101, 118, 138, 153, and 180 were measured. Levels were highest at the four sampling sites nearest the source of pollution. The highest values of PCB congeners were found in 1992. PCB content decreased from 1992 to 2003 and with distance from the source. The study indicated that leeches of the genus Erpobdella are a suitable bioindicator of contamination in the surface layer of river sediments. PMID:22573988

  10. A model for intersegmental coordination in the leech nerve cord.

    PubMed

    Pearce, R A; Friesen, W O

    1988-01-01

    The neuronal circuits that generate swimming movements in the leech were simulated by a chain of coupled harmonic oscillators. Our model incorporates a gradient of rostrocaudally decreasing cycle periods along the oscillator chain, a finite conduction delay for coupling signals, and multiple coupling channels connecting each pair of oscillators. The interactions mediated by these channels are characterized by sinusoidal phase response curves. Investigations of this model were carried out with the aid of a digital computer and the results of a variety of manipulations were compared with data from analogous physiological experiments. The simulations reproduced many aspects of intersegmental coordination in the leech, including the findings that: 1) phase lags between adjacent ganglia are larger near the caudal than the rostral end of the leech nerve cord; 2) intersegmental phase lags increase as the number of ganglia in nerve cord preparations is reduced; 3) severing one of the paired lateral connective nerves can reverse the phase lag across the lesion and 4) blocking synaptic transmission in midganglia of the ventral nerve cord reduces phase lags across the block.

  11. A classic model animal in the 21st century: recent lessons from the leech nervous system.

    PubMed

    Wagenaar, Daniel A

    2015-11-01

    The medicinal leech (genus Hirudo) is a classic model animal in systems neuroscience. The leech has been central to many integrative studies that establish how properties of neurons and their interconnections give rise to the functioning of the animal at the behavioral level. Leeches exhibit several discrete behaviors (such as crawling, swimming and feeding) that are each relatively simple. Importantly, these behaviors can all be studied - at least at a basal level - in the isolated nervous system. The leech nervous system is particularly amenable to such studies because of its distributed nature; sensory processing and generation of behavior occur to a large degree in iterated segmental ganglia that each contain only ∼400 neurons. Furthermore, the neurons are relatively large and are arranged with stereotyped topography on the surface of the ganglion, which greatly facilitates their identification and accessibility. This Commentary provides an overview of recent work on the leech nervous system, with particular focus on circuits that underlie leech behavior. Studies that combine the unique features of the leech with modern optical and genetic techniques are also discussed. Thus, this Commentary aims to explain the continued appeal of the leech as an experimental animal in the 21st century. PMID:26538172

  12. 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...

  13. Symbiont succession during embryonic development of the European medicinal leech, Hirudo verbana.

    PubMed

    Rio, Rita V M; Maltz, Michele; McCormick, Benjamin; Reiss, Alexander; Graf, Joerg

    2009-11-01

    The European medicinal leech, Hirudo verbana, harbors simple microbial communities in the digestive tract and bladder. The colonization history, infection frequency, and growth dynamics of symbionts through host embryogenesis are described using diagnostic PCR and quantitative PCR. Symbiont species displayed diversity in temporal establishment and proliferation through leech development.

  14. Salvage of venous congestion using medicinal leeches for traumatic nasal flap.

    PubMed

    Jose, Mathew; Varghese, Jomy; Babu, Arun

    2015-03-01

    Medicinal leeches are extremely useful and safe in the salvage of venous outflow compromised tissue, particularly in digit replants and various forms of flaps. Although it is unusual for a partial soft tissue avulsion of the face to require medicinal leech therapy, situations may occur in which there is adequate arterial inflow but inadequate venous outflow. In such cases, medicinal leeches may play a very important role in salvaging the soft tissue segment. We report a case of a 34-year-old gentleman who showed signs of venous congestion following primary management for a traumatic nasal flap. Successful salvage of venous congestion was done using medicinal leech therapy, once daily, for 5 days. His recovery deemed satisfactory and uncomplicated. Medicinal leeches are well-known in the treatment of venous congestion or complete venous outflow obstruction in larger pedicled flaps and microvascular transfers. In trauma, it is well established that medicinal leeches are invaluable in treating venous congestion in digit replants and replantation of totally avulsed external ear segments. A limited number of other reports have demonstrated the use of medicinal leeches for salvage of other partially avulsed facial structures. Medicinal leeches have a significant role in the management of traumatic and microvascular flaps, the oral and maxillofacial surgeon should weigh the benefits of such treatment before instituting other expensive or complex treatment modalities.

  15. 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. ...

  16. [Hirudo medicinalis-leech applications in plastic and reconstructive microsurgery--a literature review].

    PubMed

    Knobloch, K; Gohritz, A; Busch, K; Spies, M; Vogt, P M

    2007-04-01

    Medical leech therapy has enjoyed a renaissance in the world of reconstructive microsurgery during recent years. Especially venous congestion is decreased using hirudo medicinalis application such as following replantation of amputated fingers or congested flaps. They provide a temporary relief to venous engorgement whilst venous drainage is re-established. Living in symbiosis with Aeromonas hydrophila, who can digest the sixfold blood meal related to their body weight, and a broad number of anticoagulant agents such as the thrombin inhibitor hirudin, apyrase as well as collagenase, hyaluronidase, Factor Xa inhibitor and fibrinase I and II, leeches decrease venous congestion. Laser Doppler flowmetry could demonstrate a significant increase in superficial skin perfusion following leech application 16 mm around the biting zone. Following the initial blood meal accounting for about 2.5 ml, the anticoagulant effect of the various leeches enzymes follows within the next 5-6 hours, which both account for the beneficial effects. Infection associated with leech therapy is a documented complication of leech application, with reported incidences ranging from 2.4 to 20 % and a chinolone antibiotic is currently recommended to face the potential Aeromonas hydrophila infection. Anemia is a second adverse effect during medicinal leech application which has to be taken account with repetitive blood samples. Besides the successful applications of leeches in various applications in plastic and reconstructive microsurgery, randomized-controlled trials are pending to elucidate the value of hirudo medicinalis according to evidence-based criteria above from case series and case studies.

  17. Diverse molecular data demonstrate that commercially available medicinal leeches are not Hirudo medicinalis.

    PubMed

    Siddall, Mark E; Trontelj, Peter; Utevsky, Serge Y; Nkamany, Mary; Macdonald, Kenneth S

    2007-06-22

    The European medicinal leech is one of vanishingly few animal species with direct application in modern medicine. In addition to the therapeutic potential held by many protease inhibitors purified from leech saliva, and notwithstanding the historical association with quackery, Hirudo medicinalis has been approved by the United States Food and Drug Administration as a prescription medical device. Accurate annotation of bioactive compounds relies on precise species determination. Interpretations of developmental and neurophysiological characteristics also presuppose uniformity within a model species used in laboratory settings. Here, we show, with mitochondrial sequences and nuclear microsatellites, that there are at least three species of European medicinal leech, and that leeches marketed as H. medicinalis are actually Hirudo verbana. Beyond the obvious need for reconsideration of decades of biomedical research on this widely used model organism, these findings impact regulatory statutes and raise concerns for the conservation status of European medicinal leeches.

  18. Diverse molecular data demonstrate that commercially available medicinal leeches are not Hirudo medicinalis

    PubMed Central

    Siddall, Mark E; Trontelj, Peter; Utevsky, Serge Y; Nkamany, Mary; Macdonald, Kenneth S

    2007-01-01

    The European medicinal leech is one of vanishingly few animal species with direct application in modern medicine. In addition to the therapeutic potential held by many protease inhibitors purified from leech saliva, and notwithstanding the historical association with quackery, Hirudo medicinalis has been approved by the United States Food and Drug Administration as a prescription medical device. Accurate annotation of bioactive compounds relies on precise species determination. Interpretations of developmental and neurophysiological characteristics also presuppose uniformity within a model species used in laboratory settings. Here, we show, with mitochondrial sequences and nuclear microsatellites, that there are at least three species of European medicinal leech, and that leeches marketed as H. medicinalis are actually Hirudo verbana. Beyond the obvious need for reconsideration of decades of biomedical research on this widely used model organism, these findings impact regulatory statutes and raise concerns for the conservation status of European medicinal leeches. PMID:17426015

  19. 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

  20. 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.

  1. Medicinal use of leeches in the texts of ancient Greek, Roman and early Byzantine writers.

    PubMed

    Papavramidou, N; Christopoulou-Aletra, H

    2009-09-01

    Blood-letting was a common therapeutic method in antiquity; many means were used to draw blood, including the application of leeches. In this paper, ancient Greek, Roman and Byzantine authors up to the 7th century AD were studied, a research that provided us with references that may be divided into two groups: those related to the medicinal use of leeches, and those related to cases in which leeches were swallowed and had to be removed. In the first group, detailed descriptions of the method of usage and of the diseases requiring leeching were found. In the second group, brief reference is made to the problems caused by swallowing leeches, and to the methods used to expel them from the human organism. The earliest references to the medicinal use of leeches may be found in the writings of Theocritus (3rd century BC), Nicander (2nd century BC) and Horace (1st century BC, while the phenomenon of swallowing a leech is first mentioned in one of the Epidaurian 'iamata' dating to the 4th century BC.

  2. 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. PMID:19525562

  3. 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.

  4. Water and sediment toxicity assessment by use of behavioural responses of medicinal leeches.

    PubMed

    Petrauskiene, Laima

    2003-03-01

    Behaviour has been shown to be a sensitive indicator of chemically induced stress and pathology in aquatic organisms. However, ecotoxicological investigations on medicinal leech are restricted because of scarce leech resources in natural waters. We used artificially bred medicinal leech (Hirudo medicinalis L.) of two different ages: young (1-2 weeks old) and adult leeches (1 year old). Animals were exposed to: (1) waters of Lake Drukshiai-the cooler of Ignalina Nuclear Power Plant, (2) sediments of the river Nemunas and (3) solution of heavy metal model mixture (HMMM). The following behavioural responses of leech were investigated: mobility (number of moving individuals within certain periods of time), avoidance response (number of individuals escaping the tested water or sediments) changes in body shape (contractions of some muscles, abnormal position of suckers) and feeding activity (longevity of attachment process, interruptions of feeding bouts, size of blood meal). Mobility of young leeches was increased in the tested waters of Lake Drukshiai, whereas adult leeches showed no changes of this index. Avoidance response as well as impaired feeding activity (prolonged attachment process or completely suppressed attachment reflex, decreased size of blood meal) was observed in young leeches exposed to the waters from Lake Drukshiai and in adult animals exposed to all three kind of trials mentioned above. Avoidance response and changes in mobility were recorded during the first hour of exposure to tested samples; therefore, these responses can be used as an express method for water and sediment pollution assessment. Impaired feeding activity was recorded after 1-3-week exposure: this response may be used in assessing a chronic toxicity of pollution. Medicinal leech, due to its sensitivity, simplicity of measured indices and ease of laboratory maintenance, can be used as a test organism in ecotoxicity studies. PMID:12605921

  5. Water and sediment toxicity assessment by use of behavioural responses of medicinal leeches.

    PubMed

    Petrauskiene, Laima

    2003-03-01

    Behaviour has been shown to be a sensitive indicator of chemically induced stress and pathology in aquatic organisms. However, ecotoxicological investigations on medicinal leech are restricted because of scarce leech resources in natural waters. We used artificially bred medicinal leech (Hirudo medicinalis L.) of two different ages: young (1-2 weeks old) and adult leeches (1 year old). Animals were exposed to: (1) waters of Lake Drukshiai-the cooler of Ignalina Nuclear Power Plant, (2) sediments of the river Nemunas and (3) solution of heavy metal model mixture (HMMM). The following behavioural responses of leech were investigated: mobility (number of moving individuals within certain periods of time), avoidance response (number of individuals escaping the tested water or sediments) changes in body shape (contractions of some muscles, abnormal position of suckers) and feeding activity (longevity of attachment process, interruptions of feeding bouts, size of blood meal). Mobility of young leeches was increased in the tested waters of Lake Drukshiai, whereas adult leeches showed no changes of this index. Avoidance response as well as impaired feeding activity (prolonged attachment process or completely suppressed attachment reflex, decreased size of blood meal) was observed in young leeches exposed to the waters from Lake Drukshiai and in adult animals exposed to all three kind of trials mentioned above. Avoidance response and changes in mobility were recorded during the first hour of exposure to tested samples; therefore, these responses can be used as an express method for water and sediment pollution assessment. Impaired feeding activity was recorded after 1-3-week exposure: this response may be used in assessing a chronic toxicity of pollution. Medicinal leech, due to its sensitivity, simplicity of measured indices and ease of laboratory maintenance, can be used as a test organism in ecotoxicity studies.

  6. [Extract of Hirudo medicinalis leeches: biogenic substance for the creation of effective drugs].

    PubMed

    Nikonov, G I; Titova, E A; Lebedeva, A O

    2015-01-01

    Investigations of the extract of medicinal leech Girulux established parameters that enable one to verify the authenticity of related drugs using the characteristics of their UV spectra the and anticoagulant and antithrombin activity. The limits of pH must range from 5.5 to 7.5. Pilot-scale series of medical leech extract are in compliance with terms of "microbiological purity" quality characteristics. The natural storage has been used to assess the temporal stability of leech extract. The obtained characteristics showed that the activity of extract was retained after 3-year storage.

  7. Heartbeat control in leeches. II. Fictive motor pattern.

    PubMed

    Wenning, Angela; Hill, Andrew A V; Calabrese, Ronald L

    2004-01-01

    The rhythmic beating of the tube-like hearts in the medicinal leech is driven and coordinated by rhythmic activity in segmental heart motor neurons. The motor neurons are controlled by rhythmic inhibitory input from a network of heart interneurons that compose the heartbeat central pattern generator. In the preceding paper, we described the constriction pattern of the hearts in quiescent intact animals and showed that one heart constricts in a rear-to-front wave (peristaltic coordination mode), while the other heart constricts in near unison over its length (synchronous coordination mode) and that they regularly switch coordination modes. Here we analyze intersegmental and side-to-side-coordination of the fictive motor pattern for heartbeat in denervated nerve cords. We show that the intersegmental phase relations among heart motor neurons in both coordination modes are independent of heartbeat period. This finding enables us to combine data from different experiments to form a detailed analysis of the relative phases, duty cycle, and intraburst spike frequency of the bursts of the segmental heart motor neurons. The fictive motor pattern and the constriction pattern seen in intact leeches closely match in their intersegmental and side-to-side coordination, indicating that sensory feedback is not necessary for properly phased intersegmental coordination. Moreover, the regular switches in coordination mode of the fictive motor pattern mimic those seen in intact animals indicating that these switches likely arise by a central mechanism.

  8. 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...

  9. 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

  10. Genetic Diversity of Freshwater Leeches in Lake Gusinoe (Eastern Siberia, Russia)

    PubMed Central

    Kaygorodova, Irina A.; Mandzyak, Nadezhda; Petryaeva, Ekaterina; Pronin, Nikolay M.

    2014-01-01

    The study of leeches from Lake Gusinoe and its adjacent area offered us the possibility to determine species diversity. As a result, an updated species list of the Gusinoe Hirudinea fauna (Annelida, Clitellata) has been compiled. There are two orders and three families of leeches in the Gusinoe area: order Rhynchobdellida (families Glossiphoniidae and Piscicolidae) and order Arhynchobdellida (family Erpobdellidae). In total, 6 leech species belonging to 6 genera have been identified. Of these, 3 taxa belonging to the family Glossiphoniidae (Alboglossiphonia heteroclita f. papillosa, Hemiclepsis marginata, and Helobdella stagnalis) and representatives of 3 unidentified species (Glossiphonia sp., Piscicola sp., and Erpobdella sp.) have been recorded. The checklist gives a contemporary overview of the species composition of leeches and information on their hosts or substrates. The validity of morphological identification of each taxon has been verified by phylogenetic approach with a molecular marker adopted for a DNA barcoding of most invertebrates. PMID:25544958

  11. Elimination of symbiotic Aeromonas spp. from the intestinal tract of the medicinal leech, Hirudo medicinalis, using ciprofloxacin feeding.

    PubMed

    Mumcuoglu, K Y; Huberman, L; Cohen, R; Temper, V; Adler, A; Galun, R; Block, C

    2010-06-01

    The use of the medicinal leech (Hirudo medicinalis) in promoting venous drainage in tissues whose vitality is threatened by venous congestion and obstruction, especially in plastic and reconstructive surgery, has been complicated by infections caused by Aeromonas spp. These are leech endosymbionts for which patients undergoing hirudotherapy frequently receive systemic chemoprophylaxis. In order to evaluate the possibility of rendering leeches safe for use on patients, H. medicinalis were fed artificially with a 2 g/L arginine solution (used as a phagostimulant) supplemented with ciprofloxacin (100 mg/L). Aeromonads were detected in 57 out of 80 control leeches (71.3%), but in none of the 56 leeches treated with ciprofloxacin (p <0.001). Treated leeches survived for up to 4 months. Tested weekly, 61% of these leeches took human blood for at least 4 weeks after treatment and all remained negative for aeromonads. All water samples in which leeches were kept before treatment were contaminated with Aeromonas spp.; none were detected in any of the NaCl/arginine solutions with which treated animals were fed. Molecular characterization of two phenotypically distinct isolates using gyrB sequencing showed that one clustered tightly with A. veronii and the other was closely related to A. media. Other environmental bacteria and fungi were isolated from 26.5% of treated leeches that had taken a blood meal 1-4 weeks after treatment. Ciprofloxacin reduced the number of leech-associated aeromonads to undetectable levels for extended periods. Most treated leeches were ready to take a blood meal after treatment, suggesting the possibility of using ciprofloxacin-treated leeches instead of chemoprophylaxis in patients undergoing hirudotherapy.

  12. Detection of Infectious Pancreatic Necrosis Virus from the Leeches Hemiclepsis marginata and Hirudo medicinalis.

    PubMed

    Salimi, Behnam; Abdi, Kazem

    2016-12-01

    Leeches have been reported to harbor several important fish pathogens, including spring viremia of carp virus, infectious hematopoietic necrosis virus (IHNV), and viral hemorrhagic septicemia virus (VHSV), and also may contain blood protozoa. In the present study, leeches were collected from water bodies located in Kurdistan province, Iran. The specimens were tested for IHNV, VHSV, and infectious pancreatic necrosis virus (IPNV) using the PCR method. The results showed that two different species of leeches, Hemiclepsis marginata and Hirudo medicinalis, were infected by IPNV among the seven species studied. The infected leeches were found in areas that were polluted with untreated sewage coming from upstream fish farms culturing Rainbow Trout Oncorhynchus mykiss. In addition, the fish at fish farms in the vicinity had been infected with IPNV 9 months previously. Our results showed that the virus causing infectious pancreatic necrosis is present in the leeches H. marginata and H. medicinalis, suggesting that leeches are a potential source of IPNV in fish farms. Received October 14, 2015; accepted June 1, 2016. PMID:27687675

  13. The use of medical leeches for venous congestion. A review and case report.

    PubMed

    Buote, N J

    2014-01-01

    The medicinal leech, Hirudo medicinalis, has been used for hundreds of years in human medicine for a variety of diseases, most recently including venous congestion following reconstructive surgeries (skin flaps and reimplantations), excessive lingual and periorbital swelling, and non-traditional treatments for osteoarthritis, compartment syndrome and sialoadenitis. The treatment of venous congestion in animals using leeches has been mentioned anecdotally, but the only published report pertains to the use of leeches in a cat suffering from polycythemia vera. We report the use of medical grade leeches in a one-year-old male castrated Domestic Shorthaired cat presenting with severe swelling of the paw after sustaining a constrictive injury from a bandage. The limb use had become compromised and the swelling was not responsive to compression bandages so leech therapy was instituted for four days and the swelling dramatically improved. The patient's limb use improved back to normal and the constrictive wound went on to heal without complication. The use of leeches in this case allowed for resolution of severe venous congestion and a full return to function in this patient with no continued skin loss. The mechanism of action of hirudotherapy for venous congestion is to allow for an alternative egress of pooled venous blood leading to a reduction in capillary pressure and increases in arterial reperfusion of capillary beds. The human and veterinary applications, method, and potential complications with hirudotherapy are discussed in this review.

  14. Bacterial symbiont and salivary peptide evolution in the context of leech phylogeny.

    PubMed

    Siddall, Mark E; Min, Gi-Sik; Fontanella, Frank M; Phillips, Anna J; Watson, Sara C

    2011-11-01

    The evolutionary history of leeches is employed as a general framework for understanding more than merely the systematics of this charismatic group of annelid worms, and serves as a basis for understanding blood-feeding related correlates ranging from the specifics of gut-associated bacterial symbionts to salivary anticoagulant peptides. A variety of medicinal leech families were examined for intraluminal crop bacterial symbionts. Species of Aeromonas and Bacteroidetes were characterized with DNA gyrase B and 16S rDNA. Bacteroidetes isolates were found to be much more phylogenetically diverse and suggested stronger evidence of phylogenetic correlation than the gammaproteobacteria. Patterns that look like co-speciation with limited taxon sampling do not in the full context of phylogeny. Bioactive compounds that are expressed as gene products, like those in leech salivary glands, have 'passed the test' of evolutionary selection. We produced and bioinformatically mined salivary gland EST libraries across medicinal leech lineages to experimentally and statistically evaluate whether evolutionary selection on peptides can identify structure-function activities of known therapeutically relevant bioactive compounds like antithrombin, hirudin and antistasin. The combined information content of a well corroborated leech phylogeny and broad taxonomic coverage of expressed proteins leads to a rich understanding of evolution and function in leech history.

  15. Leech Therapy- A Holistic Approach of Treatment in Unani (Greeko-Arab) Medicine

    PubMed Central

    Lone, Azad Hussain; Ahmad, Tanzeel; Anwar, Mohd; Habib, Shahida; Sofi, Gh; Imam, Hashmat

    2011-01-01

    The Unani System of Medicine also known as Greeko-Arab medicine, founded by Hippocrates is based on the concept of equilibrium and balance of natural body humours (blood, bile, black bile and phlegm). The imbalance in the quality and quantity of these humours leads to diseases whereas restoration of this balance maintains health of a person. The treatment methodology of diseases is based on four therapeutic modalities viz. Regimental therapy, Dieto-therapy, Pharmacotherapy and surgery. Irsale Alaq (Leech or Hirudo therapy) is one of the most important and widely practised methods of regimental therapy used for local evacuation of morbid humours. It is a procedure of treatment with the use of medicinal leeches. It has been suggested and successfully practised by Greeko-Arab physicians in the management of musculoskeletal diseases, gynaecological disorders, chronic skin diseases, thromboembolic diseases, varicose veins, ENT disorders etc since long. According to Unani doctrine, the efficacy of leech therapy is attributed to the analgesic and resolvent activities of leeches. However, from modern perspective, the saliva of leech contains about 100 pharmacologically active biological substances like Hirudin, hyaluronidase, vasodilators, anesthetics, antibacterial, fibrinases, collagenase etc. These substances are injected into human body while sucking of the blood and are responsible for the analgesic, anti inflammatory and anesthetic effects of leech therapy. PMID:22736888

  16. 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.

  17. Chromosome numbers for three species of medicinal leeches (Hirudo spp.).

    PubMed

    Utevsky, Serge; Kovalenko, Nataliya; Doroshenko, Karyna; Petrauskiene, Laima; Klymenko, Vyacheslav

    2009-10-01

    Karyological preparations were made from the testisacs of three medicinal leech species Hirudo medicinalis Linnaeus, 1758, H. verbana Carena, 1820 and H. orientalis Utevsky & Trontelj, 2005 . The samples originated from different populations in Azerbaijan, Kazakhstan, Russian Federation, Ukraine and Uzbekistan. The chromosome numbers were determined both from mitotic and meiotic stages of spermatogenesis using the propionic haematoxylin staining technique. All three species were found to have different haploid chromosome numbers: H. medicinalis 14, H. verbana 13 and H. orientalis 12, thus corroborating the validity of these taxa. The chromosomes can be classified as meta-, submetacentric and acrocentric. The chromosome numbers obtained are similar to that of the related species Haemopis sanguisuga (Linnaeus, 1758), which has 13 pairs.

  18. Diversity and selective pressures of anticoagulants in three medicinal leeches (Hirudinida: Hirudinidae, Macrobdellidae).

    PubMed

    Kvist, Sebastian; Min, Gi-Sik; Siddall, Mark E

    2013-04-01

    Although medicinal leeches have long been used as treatment for various ailments because of their potent anticoagulation factors, neither the full diversity of salivary components that inhibit coagulation, nor the evolutionary selection acting on them has been thoroughly investigated. Here, we constructed expressed sequence tag libraries from salivary glands of two species of medicinal hirudinoid leeches, Hirudo verbana and Aliolimnatis fenestrata, and identified anticoagulant-orthologs through BLASTx searches. The data set then was augmented by the addition of a previously constructed EST library from the macrobdelloid leech Macrobdella decora. The identified orthologs then were compared and contrasted with well-characterized anticoagulants from a variety of leeches with different feeding habits, including non-sanguivorous species. Moreover, four different statistical methods for predicting signatures of positive and negative evolutionary pressures were used for 10 rounds each to assess the level and type of selection acting on the molecules as a whole and on specific sites. In total, sequences showing putative BLASTx-orthology with five and three anticoagulant-families were recovered in the A. fenestrata and H. verbana EST libraries respectively. Selection pressure analyses predicted high levels of purifying selection across the anticoagulant diversity, although a few isolated sites showed signatures of positive selection. This study represents a first attempt at mapping the anticoagulant repertoires in a comparative fashion across several leech families.

  19. The medical use of leeches in contemporary Spain: between science and tradition.

    PubMed

    Vallejo, Jose Ramon; Gonzalez, Jose Antonio

    2015-01-01

    In Spain leeches have been used both in popular and scientific medicine throughout its history. In this study we analyze the historical fluctuations of leech therapy. At the start of the 20th century it was still being used in in scientific medicine, as can be seen in the treatment administered to Germán Gamazo, a minister during the reign of Alfonso XII and the regency of Archduchess Maria Christina of Austria, during a serious illness in 1901. Leech therapy was to fall dramatically into disuse and was to survive only in folk medicine, with leeches losing their reputation as a therapeutic agent. The data obtained is the result of a systematic review of the literature and of the major databases in the fields of folklore, ethnography, social anthropology and medical anthropology. Leeches have been used in Spanish folk medicine to treat ailments and disorders in up to 11 categories of the International Statistical Classification of Diseases and Related Health Problems (ICD-10), particularly in the treatment of diseases of the circulatory, respiratory and musculoskeletal systems. According to the available literature, they were part of the folk therapeutic arsenal, at least until the seventies of the last century. Our study also provides information about the medicinal use, commerce and consumption of these animals in recent years.

  20. 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. PMID:23483830

  1. An Unusual Cause of Bleeding on the Floor of Mouth: Leech Infestation.

    PubMed

    Kantekin, Yunus; Sarı, Kamran; Özkırış, Mahmut; Kapusuz Gencer, Zeliha

    2015-12-01

    Leech infestation is a very rare phenomenon in humans. It mostly occurs in humans when rural untreated water is drunk or while swimming in streams or lakes. When leeches adhere to the mucous membrane, they ingest blood. Thus, they can sometimes cause severe anemia that may require blood transfusion. We report a case that was referred to emergency service with bleeding in the floor of the mouth. A 10-year-old child was referred to the emergency service of a city hospital with a complaint of swelling in the floor of the mouth and spitting of blood. The patient was promptly taken to the operating room. Using local anesthesia, a surgical incision was made, and a moving, dark brown foreign body was removed from the floor of the mouth and identified as a leech. Leech endoparasitism should be considered as a cause of unexplained anemia due to bleeding from the throat. Accordingly, leech infestation must be considered in differential diagnosis when a patient complains of spitting of blood, hoarseness, or dysphagia.

  2. An Unusual Cause of Bleeding on the Floor of Mouth: Leech Infestation.

    PubMed

    Kantekin, Yunus; Sarı, Kamran; Özkırış, Mahmut; Kapusuz Gencer, Zeliha

    2015-12-01

    Leech infestation is a very rare phenomenon in humans. It mostly occurs in humans when rural untreated water is drunk or while swimming in streams or lakes. When leeches adhere to the mucous membrane, they ingest blood. Thus, they can sometimes cause severe anemia that may require blood transfusion. We report a case that was referred to emergency service with bleeding in the floor of the mouth. A 10-year-old child was referred to the emergency service of a city hospital with a complaint of swelling in the floor of the mouth and spitting of blood. The patient was promptly taken to the operating room. Using local anesthesia, a surgical incision was made, and a moving, dark brown foreign body was removed from the floor of the mouth and identified as a leech. Leech endoparasitism should be considered as a cause of unexplained anemia due to bleeding from the throat. Accordingly, leech infestation must be considered in differential diagnosis when a patient complains of spitting of blood, hoarseness, or dysphagia. PMID:26809923

  3. Morphological and genetic variations of the freshwater leech, Hirudinaria spp., in Peninsular Malaysia.

    PubMed

    Chong, L K; Ong, Alan H K; Tan, S G; Taranjeet, K A S; Peris, M M; Sana, A M M A; Hassan, H R

    2014-06-01

    In this study the genetic diversity of local freshwater leeches (Hirudinaria spp.) was inferred using mtDNA COI gene analysis and compared with the gross external variations of 26 freshwater leech specimens obtained from the wild and leech farms. Based on a neighbor-joining tree generated from 516 COI base sequences, four distinct clades of Hirudinaria were seen with interspecific genetic divergence in the range of 7.6-14.5%. The external morphological variations based on the presence of stripes, location of gonopores, and anus separated the samples into four morphologically distinct groups matching the four clades obtained from the molecular data. Two black stripes at the ventral region were observed only in specimens found clustered with clades that contained the GenBank-reported H. manillensis, whereas the brown or dark green coloration without stripes on the ventral region was seen in samples that clustered with H. javanica and H. bpling clades. PMID:24535156

  4. The medicinal leech as a convenient tool for water toxicity assessment.

    PubMed

    Petrauskiene, Laima

    2004-08-01

    Medicinal leeches previously were used in various toxicological and pharmacological studies because they are sensitive and easy to keep under laboratory conditions. Toxicological studies using leeches became restricted when their natural sources decreased dramatically. We breed medicinal leeches under laboratory conditions and have the possibility of using them for various investigations. The aim of the current study was to investigate changes in behavioral and physiological responses of leeches exposed to a heavy metal model mixture (HMMM). The composition of the HMMM was determined on the basis of the average annual amounts of representative metals (Zn, Mn, Cu, Cr, Ni, Cd, and Pb) in wastewater discharging from the Ignalina Nuclear Power Plant. An annual average was considered a concentration of 1%. Animals were exposed to 0.13%, 0.25%, 0.5%, 1%, and 2% concentrations of the HMMM. The avoidance responses, changes in body weight, feeding behavior, and excretion rates of the leeches were recorded. Avoidance response was observed in animals treated with 1% and 2% concentrations of the HMMM during the first 2 h of exposure. A decrease in body weight was recorded after a 4-week exposure to all tested concentrations. Disturbances in feeding behavior were observed after a 4-week exposure to 0.13%-2% concentrations. An increase in the defecation rate was observed during the 5-week exposure to 0.25%-2% concentrations. The excretion rate via nephridia was decreased during postfeeding period after exposure to 0.25%-2% concentrations. The avoidance response of medicinal leeches can be used as an express method for water quality assessment, whereas physiological responses may be used for the assessment of chronic toxicity of polluted environments.

  5. The physiology and mechanics of undulatory swimming: a student laboratory exercise using medicinal leeches.

    PubMed

    Ellerby, David J

    2009-09-01

    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 mechanics, hydrostatic skeletons, and the physiological features that allow leeches to deal with the volume increase and osmotic load imposed by the meal. Analyses can be carried out at a range of levels tailored to suit a particular class.

  6. 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

  7. 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.

  8. [Inheritance of reproductive traits of medicinal leeches (Hirudo medicinalis L.)].

    PubMed

    Utevskaia, O M; Atramentova, L A

    2002-01-01

    The phenotype variability and inheritance of reproductive traits were investigated in the medicinal leech. Distribution parameters were determined for the following traits: batch size (X = 4.3 +/- 0.2, sigma = 1.7, CV = 40%, As = 0.23 +/- 0.25, Ex = 0.19 +/- 0.51), number of juveniles in a cocoon (X = 10.9 +/- 0.3, sigma = 4.6, CV = 42%, As = 0.31 +/- 0.15, Ex = 0.23 +/- 0.30), and juvenile weight (X = 32.0 +/- 0.3, sigma = 14.9, CV = 47%, As = 1.38 +/- 0.05, Ex = 3.32 +/- 0.11. A nonlinear negative correlation between the number of juveniles in a cocoon and their weight was found (correlation ratio R = 0.86). It was shown that the environmental variance dominated over the genotypic one in the structure of phenotypic variance of the traits studied. The genetic variability is determined mainly by additive gene interactions and, to a small extent, intralocus dominance. The narrow-sense heritability, h2, for batch size was 0.35-0.40; for the number of juveniles in a cocoon, 0.35; for juvenile weight, 0.42.

  9. 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

  10. Analysis of responses in visual cells of the leech

    PubMed Central

    Fioravanti, R.; Fuortes, M. G. F.

    1972-01-01

    1. Potentials were recorded from the cytoplasm and from the vacuole of leech photoreceptors. Since the vacuole is lined with microvilli and is connected to the outside by narrow channels, the potential drops between vacuole and outside measure the current through the microvillar membrane. 2. In darkness, the potential of the cytoplasm with respect to the outside is about — 45 mV while the potential of the vacuole is approximately zero. 3. Following illumination the negativity of the cytoplasm decreases and the vacuole becomes negative relative to the outside. 4. For dim intensities, the response to a flash of light may grow proportionately more than the intensity of the flash. This is probably due to development of a depolarizing local response. 5. The resistance from the cytoplasm to the outside was about 150 MΩ in darkness and decreased to approximately 40 MΩ at the peak of the response to a bright flash (on average). Corresponding measurements from the vacuole gave 50 MΩ in darkness and 35 MΩ at the peak of the response. 6. Charging curves produced by steps of constant currents applied to the cytoplasm or to the vacuole include two time constants (about 5 and 50 msec on average). The longer time constant decreases greatly with bright illumination. 7. The results are consistent with the interpretation that the response to light is brought about by an increase of conductance of the microvillar membrane. PMID:4646575

  11. The bacterial community associated with the leech Myzobdella lugubris Leidy 1851 (Hirudinea: Piscicolidae) from Lake Erie, Michigan, USA.

    PubMed

    Schulz, C; Faisal, M

    2010-06-01

    Leeches are widespread in the Great Lakes Basin, yet their potential to harbor disease-causing agents has not been investigated. The purpose of this study was to identify the bacterial community of the commonly occurring leech, Myzobdella lugubris, within the Lake Erie Watershed. Leech samples were collected from the pectoral fins of channel catfish, Ictalurus punctatus, and freshwater drum, Aplodinotus grunniens, from Lake Erie in commercial trap nets and pooled into two samples based on host attachment. Bacteria from within the viscera of M. lugubris were identified by sequencing their 16S rRNA (rDNA) gene of amplified community bacterial DNA extracted from pooled leech homogenate samples and were checked for similarity in two public databases: the Ribosomal Database Project and BLAST. Bacteria belonging to the phylum Bacteroidetes, beta-proteobacteria, Verrucomicrobia, and unclassified Bacteria were present in the leech samples. A large number of bacteria found within leeches attached to channel catfish consisted of sequences that could not be classified beyond the Domain Bacteria. However, many of these sequences were homologous (< 45%) to the phylum Bacteroidetes. One of the five genera detected in the leech homogenates was Flavobacterium psychrophilum, a serious fish pathogen that causes Bacterial Cold Water Disease. While the occurrence of genera varies, bacteria associated with the two fish species were similar.

  12. 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.

  13. [Lysozyme activity of the salivary gland secretion of the medicinal leech H. verbana, H. medicinalis and H. orientalis].

    PubMed

    Baskova, I P; Kharitonova, O V; Zavalova, L L

    2011-01-01

    Salivary gland secretions of three species of the medicinal leech differ in the level of lysozyme peptidoglycan-lysing activity. Using the synthetic fluorogenic substrate, 4-methyl-umbelliferyl tetra N-acetyl-beta-chitotetraosid, the glycosidase activity (as one of peptidoglycan-lysing activities) of salivary gland secretion of three species of the medicinal leech was quantitatively evaluated in comparison with egg lysozyme. It is supposed, that lysozyme activity of the leech secretions is determined not only by 5 isoforms of destabilase-lysozyme, but by some other enzymes which can utilize this substrate. These may be lysozymes other than i- (invertebrate) lysozymes (such as destabilase-lysozyme, or related enzymes).

  14. The use of dendrograms to describe the electrical activity of motoneurons underlying behaviors in leeches

    PubMed Central

    Juárez-Hernández, León J.; Bisson, Giacomo; Torre, Vincent

    2013-01-01

    The present manuscript aims at identifying patterns of electrical activity recorded from neurons of the leech nervous system, characterizing specific behaviors. When leeches are at rest, the electrical activity of neurons and motoneurons is poorly correlated. When leeches move their head and/or tail, in contrast, action potential (AP) firing becomes highly correlated. When the head or tail suckers detach, specific patterns of electrical activity are detected. During elongation and contraction the electrical activity of motoneurons in the Medial Anterior and Dorsal Posterior nerves increase, respectively, and several motoneurons are activated both during elongation and contraction. During crawling, swimming, and pseudo-swimming patterns of electrical activity are better described by the dendrograms of cross-correlations of motoneurons pairs. Dendrograms obtained from different animals exhibiting the same behavior are similar and by averaging these dendrograms we obtained a template underlying a given behavior. By using this template, the corresponding behavior is reliably identified from the recorded electrical activity. The analysis of dendrograms during different leech behavior reveals the fine orchestration of motoneurons firing specific to each stereotyped behavior. Therefore, dendrograms capture the subtle changes in the correlation pattern of neuronal networks when they become involved in different tasks or functions. PMID:24098274

  15. Identification, isolation and expansion of myoendothelial cells involved in leech muscle regeneration.

    PubMed

    Grimaldi, Annalisa; Banfi, Serena; Gerosa, Laura; Tettamanti, Gianluca; Noonan, Douglas M; Valvassori, Roberto; de Eguileor, Magda

    2009-01-01

    Adult skeletal muscle in vertebrates contains myoendothelial cells that express both myogenic and endothelial markers, and which are able to differentiate into myogenic cells to contribute to muscle regeneration. In spite of intensive research efforts, numerous questions remain regarding the role of cytokine signalling on myoendothelial cell differentiation and muscle regeneration. Here we used Hirudo medicinalis (Annelid, leech) as an emerging new model to study myoendothelial cells and muscle regeneration. Although the leech has relative anatomical simplicity, it shows a striking similarity with vertebrate responses and is a reliable model for studying a variety of basic events, such as tissue repair. Double immunohistochemical analysis were used to characterize myoendothelial cells in leeches and, by injecting in vivo the matrigel biopolymer supplemented with the cytokine Vascular Endothelial Growth Factor (VEGF), we were able to isolate this specific cell population expressing myogenic and endothelial markers. We then evaluated the effect of VEGF on these cells in vitro. Our data indicate that, similar to that proposed for vertebrates, myoendothelial cells of the leech directly participate in myogenesis both in vivo and in vitro, and that VEGF secretion is involved in the recruitment and expansion of these muscle progenitor cells. PMID:19876402

  16. The leech nervous system: a valuable model to study the microglia involvement in regenerative processes.

    PubMed

    Le Marrec-Croq, Françoise; Drago, Francesco; Vizioli, Jacopo; Sautière, Pierre-Eric; Lefebvre, Christophe

    2013-01-01

    Microglia are intrinsic components of the central nervous system (CNS). During pathologies in mammals, inflammatory processes implicate the resident microglia and the infiltration of blood cells including macrophages. Functions of microglia appear to be complex as they exhibit both neuroprotective and neurotoxic effects during neuropathological conditions in vivo and in vitro. The medicinal leech Hirudo medicinalis is a well-known model in neurobiology due to its ability to naturally repair its CNS following injury. Considering the low infiltration of blood cells in this process, the leech CNS is studied to specify the activation mechanisms of only resident microglial cells. The microglia recruitment is known to be essential for the usual sprouting of injured axons and does not require any other glial cells. The present review will describe the questions which are addressed to understand the nerve repair. They will discuss the implication of leech factors in the microglial accumulation, the identification of nerve cells producing these molecules, and the study of different microglial subsets. Those questions aim to better understand the mechanisms of microglial cell recruitment and their crosstalk with damaged neurons. The study of this dialog is necessary to elucidate the balance of the inflammation leading to the leech CNS repair. PMID:23878582

  17. Morphological and functional characterization of leech circulating blood cells: role in immunity and neural repair.

    PubMed

    Boidin-Wichlacz, Céline; Vergote, David; Slomianny, Christian; Jouy, Nathalie; Salzet, Michel; Tasiemski, Aurélie

    2012-05-01

    Unlike most invertebrates, annelids possess a closed vascular system distinct from the coelomic liquid. The morphology and the function of leech blood cells are reported here. We have demonstrated the presence of a unique cell type which participates in various immune processes. In contrast to the mammalian spinal cord, the leech CNS is able to regenerate and restore function after injury. The close contact of the blood with the nerve cord also led us to explore the participation of blood in neural repair. Our data evidenced that, in addition to exerting peripheral immune functions, leech blood optimizes CNS neural repair through the release of neurotrophic substances. Circulating blood cells also appeared able to infiltrate the injured CNS where, in conjunction with microglia, they limit the formation of a scar. In mammals, CNS injury leads to the generation of a glial scar that blocks the mechanism of regeneration by preventing axonal regrowth. The results presented here constitute the first description of neuroimmune functions of invertebrate blood cells. Understanding the basic function of the peripheral circulating cells and their interactions with lesioned CNS in the leech would allow us to acquire insights into the complexity of the neuroimmune response of the injured mammalian brain. PMID:22159559

  18. 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 ...

  19. 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.

  20. Characterization of the digestive-tract microbiota of Hirudo orientalis, a european medicinal leech.

    PubMed

    Laufer, Alison S; Siddall, Mark E; Graf, Joerg

    2008-10-01

    FDA-approved, postoperative use of leeches can lead to bacterial infections. In this study, we used culture-dependent and culture-independent approaches to characterize the digestive-tract microbiota of Hirudo orientalis. Surprisingly, two Aeromonas species, A. veronii and A. jandaei, were cultured. Uncultured Rikenella-like bacteria were most similar to isolates from Hirudo verbana.

  1. Draft Genome Sequence of Pedobacter sp. Strain Hv1, an Isolate from Medicinal Leech Mucosal Castings

    PubMed Central

    Ott, Brittany M.; Beka, Lidia; Graf, Joerg

    2015-01-01

    The Pedobacter sp. Hv1 strain was isolated from the medicinal leech, Hirudo verbana, mucosal castings. These mucosal sheds have been demonstrated to play a role in horizontal symbiont transmission. Here, we report the draft 4.9 Mbp genome sequence of Pedobacter sp. strain Hv1. PMID:26679583

  2. 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…

  3. 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...

  4. Effect of taleeq (leech therapy) in dawali (varicose veins).

    PubMed

    Nigar, Zar; Alam, Md Anwar

    2011-01-01

    Dawali (varicose vein) is first described in Ebers Papyrus over 3500 years ago. Dawali is a disease in which veins of legs and feet become dilated, tortuous, and greenish in colour due to excess accumulation of blood which is derived from saudavi madda & balgham ghaleez. The aetiology of varicose veins is still incompletely under stood, despite the fact that it is a very common disease affecting all ages from teenagers to elderly people. The complication of varicose veins like venous eczema, venous pigmentation, lipodermatosclerosis, superficial thrombophlebitis, venous ulceration, etc impair health related quality of life significantly. The objective of the study is to evaluate the efficacy of Taleeq in Dawali and to provide safe & cost effective alternative treatment. Randomized controlled clinical open trial was conducted in regimenal unit of NIUM Hospital. 50 patients were divided into 2 groups, 30 in test & 20 in control group. Test group was treated with Taleeq on alternate day & control group was treated with grade 2 compression stockings & limb elevation for 2 months. Response was measured by assessment of pain / leg discomfort, limb girth at calf, ankle, and feet, pigmentation area & colour on every 15(th) day. Hb% was assessed on every 15(th) day to check anaemia. Effect on anatomy of vein was assessed by colour flow Doppler USG. Test group showed significant reduction in pain, limb girth, pigmentation, number of perforators. Control group showed significant reduction in pain & limb girth, but there was no improvement on pigmentation. Both groups do not show significant improvement on SFJ & SPJ incompetency. Test group has major effects in improvement of all parameters. Study stresses that leech therapy should be administered in combination with compression stockings & other effective treatment modalities like weight normalization for obese patients, physical therapy, dietary modification etc for optimal results. PMID:22557433

  5. Stratified bacterial community in the bladder of the medicinal leech, Hirudo verbana.

    PubMed

    Kikuchi, Yoshitomo; Bomar, Lindsey; Graf, Joerg

    2009-10-01

    Most animals harbour symbiotic microorganisms inside their body, where intimate interactions occur between the partners. The medicinal leech, Hirudo verbana, possesses 17 pairs of excretory bladders that harbour a large number of intracellular and extracellular symbiotic bacteria. In this study, we characterized the bladder symbionts using molecular phylogenetic analyses, transmission electron microscopy (TEM) and fluorescence in situ hybridization (FISH). Restriction fragment length polymorphism (RFLP) and sequence analyses of 16S rRNA gene clone libraries suggested that six bacterial species co-colonize the leech bladders. Phylogenetic analyses revealed that these species belong to the alpha-Proteobacteria (Ochrobactrum symbiont), beta-Proteobacteria (Beta-1 and Beta-2 symbionts), delta-Proteobacteria (Bdellovibrio symbiont) and Bacteroidetes (Niabella and Sphingobacterium symbionts). Species-specific PCR detection and FISH confirmed the localization of the symbiotic bacteria in the bladders. The Ochrobactrum, Beta-1, Bdellovibrio and Sphingobacterium symbionts were consistently detected in 13 leeches from two populations, while infection rate of the other symbionts ranged between 20% and 100% in the two leech populations. Transmission electron microscopy observations of the bladders revealed epithelial cells harbouring a number of intracellular bacilli and an additional type of extracellular, rod-shaped bacteria in the luminal region. Fluorescence in situ hybridization with group-specific oligonucleotide probes revealed the spatial organization of the bacterial species in the bladder: the Ochrobactrum symbiont was located intracellularly inside epithelial cells; the Bacteroidetes were localized close to the epithelium in the lumen of the bladder; and the Bacteroidetes layer was covered with dense beta-proteobacterial cells. These results clearly demonstrate that a simple but organized microbial community exists in the bladder of the medicinal leech.

  6. Viral infection risks for patients using the finished product Hirudo verbana (medicinal leech).

    PubMed

    von Rheinbaben, Friedrich; Riebe, Oliver; Koehnlein, Johanna; Werner, Sebastian

    2014-11-01

    The virological safety of medicinal leeches has to be ensured prior to their use on patients. While leeches can be kept and bred under standardized conditions, feeding them horse blood adds a non-standardized component, which poses some risk of infection of the treated patients. Here, we investigated the speed at which blood-borne viruses are degraded by the microbial flora in the leech intestine, in order to define the safety of the product and the length of the necessary quarantine period prior to its administration to patients. Feeding blood was spiked with bovine viral diarrhea virus (BVDV), reovirus, and murine parvovirus (10(7) ID₅₀ ml(-1)). The virus titer in the intestinal contents of the leeches was determined using permissive cell cultures and compared to that of the original virus titer at the following time points: immediately after feeding; after 3, 14, and 30 days; and monthly thereafter until the 7th month. The BVDV titer was below the detection limit of 10(1) TCID₅₀ ml(-1) after 3 months, while reovirus and murine parvovirus titers were undetectable after 4 months. No positive virus findings were obtained at later time points. Thus, when fed the blood of vertebrates, the finished product "Medicinal leech, Hirudo verbana" can be considered virologically safe if the animals are maintained at 20 °C, which corresponds to their natural habitat conditions and ensures a high metabolic rate. Therefore, after the last feeding, a quarantine period of 4-6 months and appropriate care at room temperature, which supports microbial degradation and digestive processes, are recommended.

  7. 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...

  8. Preventing Infective Complications following Leech Therapy: Elimination of Symbiotic Aeromonas spp. from the Intestine of Hirudo verbana Using Antibiotic Feeding

    PubMed Central

    Litwinowicz, Agata

    2014-01-01

    Abstract Background: Hirudotherapy is often used successfully in modern medicine, especially in plastic and reconstructive surgery. However, Aeromonas infections are the most common complications of post-operative leech application. Hence, prophylactic antibiotic administration is recommended before and during leech therapy. It has been confirmed that patient safety and achieving the desired therapeutic effect depend mainly on the microbiologic purity of the animals used. The aims of this study were to find a safe and practical way to eradicate symbiotic Aeromonas spp. occuring in the intestine of Hirudo verbana. Methods: Leeches were fed artificially with 1.5 mL of sterile defibrinated sheep blood supplemented with ciprofloxacin (CIP) or cefotaxime (CTX), at bacteriostatic concentrations of 0.2 mcg/mL or 1.5 mcg/mL, and bactericidal concentrations of 20 mcg/mL or 50 mcg/mL, respectively. Bacteria were isolated from the leech intestines before and after feeding at different time intervals: 1, 7, 14, 21, and 28 d. Results: Biochemical identification of bacterial isolates from water samples and intestines of H. verbana using the API-NE20 test showed that A. veronii biovar sobria was predominant. Bacteria belonging to the genus Aeromonas were detected in all control leeches. The results showed that optimum eradication of bacteria from leech intestines was obtained using 20 mcg/mL of CIP and 50 mcg/mL of CTX, which decreased the number of Aeromonas spp. to undetectable levels for two weeks after feeding in all treated leeches. A statistically significant reduction in the number of bacterial colonies (p<0.0001) was observed in leeches treated with bacteriostatic concentrations of CIP or CTX; no bacterial growth was found on the plates after only seven days of feeding with antibiotics. All water samples in which the leeches were kept before treatment were contaminated with Aeromonas spp., whereas these samples were negative after antibiotic feeding of

  9. 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

    2015-01-01

    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. PMID:26623905

  10. Proteins and peptides of the salivary gland secretion of medicinal leeches Hirudo verbana, H. medicinalis, and H. orientalis.

    PubMed

    Baskova, I P; Kostrjukova, E S; Vlasova, M A; Kharitonova, O V; Levitskiy, S A; Zavalova, L L; Moshkovskii, S A; Lazarev, V N

    2008-03-01

    The protein and peptide composition of medicinal leech salivary gland secretion (SGS) was analyzed in preparations obtained in July from three species--Hirudo verbana, H. medicinalis, and H. orientalis. Two-dimensional electrophoresis (molecular mass 10-150 kD and pI 3-10) revealed no distinctions in the distribution of over 100 silver-stained proteins. Differences were noted only in intensity of 10 protein spots at 30-90 kD and pI 4.7-7.5. Mass spectrometric profiling of SGS of the three leech species using the Zip-Tip/golden chip scheme and cation-exchanging chips CM-10 revealed over 50 components in SGS of each of the three leech species. It was noted that 30-40% of the individual masses of the SGS of each leech species fall within the masses present in SGS of at least one of the two other species. This rather small part of the total mass may be indicative of a high polymorphism of amino acid sequences or a high frequency of posttranslational modifications of the SGS proteins and peptides. Calculation of Jacquard's coefficient showed that H. medicinalis and H. orientalis are closest to each other in SGS composition, which is consistent with data in the literature on the phylogenetic relationship between these two species of medicinal leech. Comparison of detected molecular masses with those of six known biologically active compounds produced by medicinal leeches revealed their uneven distribution in SGS of each of the three medicinal leech species. This opens prospects for using certain species of medicinal leech for targeted therapy of various pathologies.

  11. 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

    2015-01-01

    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.

  12. Localized RNAi and ectopic gene expression in the medicinal leech.

    PubMed

    Shefi, Orit; Simonnet, Claire; Groisman, Alex; Macagno, Eduardo R

    2008-04-17

    In this video, we show the use of a pneumatic capillary gun for the accurate biolistic delivery of reagents into live tissue. We use the procedure to perturb gene expression patterns in selected segments of leech embryos, leaving the untreated segments as internal controls. The pneumatic capillary gun can be used to reach internal layers of cells at early stages of development without opening the specimen. As a method for localized introduction of substances into living tissues, the biolistic delivery with the gun has several advantages: it is fast, contact-free and non-destructive. In addition, a single capillary gun can be used for independent delivery of different substances. The delivery region can have lateral dimensions of approximately 50-150 microm and extends over approximately 15 microm around the mean penetration depth, which is adjustable between 0 and 50 microm. This delivery has the advantage of being able to target a limited number of cells in a selected location intermediate between single cell knock down by microinjection and systemic knockdown through extracellular injections or by means of genetic approaches. For knocking down or knocking in the expression of the axon guidance molecule Netrin, which is naturally expressed by some central neurons and in the ventral body wall, but not the dorsal domain, we deliver molecules of dsRNA or plasmid-DNA into the body wall and central ganglia. This procedure includes the following steps: (i) preparation of the experimental setup for a specific assay (adjusting the accelerating pressure), (ii) coating the particles with molecules of dsRNA or DNA, (iii) loading the coated particles into the gun, up to two reagents in one assay, (iv) preparing the animals for the particle delivery, (v) delivery of coated particles into the target tissue (body wall or ganglia), and (vi) processing the embryos (immunostaining, immunohistochemistry and neuronal labeling) to visualize the results, usually 2 to 3 days after the

  13. 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

  14. 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

  15. Upper airway obstruction and hemoptysis due to a leech infestation in a child.

    PubMed

    Draiss, G; Razzouki, K; Mouaffak, Y; Bouskraoui, M; Younous, S

    2016-01-01

    This paper presents the case of a 12-year-old child who presented with an 8-day history of cough, respiratory distress, and hemoptysis. He was admitted first to the pediatric intensive care unit to reestablish hemodynamic and respiratory stability. The chest X-ray showed a bilateral alveolar-interstitial syndrome. Four hours after admission, he had a coughing fit, moderately abundant hemoptysis, and a leech appeared in his mouth, which was removed by the mother. Symptoms completely disappeared afterwards. Endoscopy and ear-throat-laryngeal examination done thereafter were normal. The presence of a leech in the larynx has been rarely described in children, but is not a rare cause of hemoptysis. Extraction is imperative and should be performed as soon as the diagnosis is made to avoid a fatal progression. Prevention remains the best treatment. PMID:26655785

  16. 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.

  17. Leech Induced Pyoderma Gangrenosum in an Ulcerative Colitis Patient: A Case Report

    PubMed Central

    Sadeghi, Anahita; Navabakhsh, Behrouz; Izadi Vahedi, Niloofar

    2016-01-01

    Pyoderma gangrenosum (PG) is a painful skin lesion that results from excessive inflammatory response to a host of traumatic, inflammatory, or neoplastic processes in susceptible individuals. A clear pathogenetic mechanism as well as an exhaustive list of potential triggers for PG is yet to be fully characterized. This case documents the occurrence of pyoderma gangrenosum following leech-therapy in a patient who is a known case of ulcerative colitis and it deserves attention because leeches have been part of medical armamentarium since ancient times and have re-emerged in the last century relying on their ancient charm and modern research revealing potential benefits of several bioactive substances in their saliva. PMID:26933484

  18. Alpha-conotoxin ImI disrupts central control of swimming in the medicinal leech.

    PubMed

    Wagenaar, Daniel A; Gonzalez, Ruben; Ries, David C; Kristan, William B; French, Kathleen A

    2010-11-26

    Medicinal leeches (Hirudo spp.) swim using a metachronal, front-to-back undulation. The behavior is generated by central pattern generators (CPGs) distributed along the animal's midbody ganglia and is coordinated by both central and peripheral mechanisms. Here we report that a component of the venom of Conus imperialis, α-conotoxin ImI, known to block nicotinic acetyl-choline receptors in other species, disrupts swimming. Leeches injected with the toxin swam in circles with exaggerated dorsoventral bends and reduced forward velocity. Fictive swimming in isolated nerve cords was even more strongly disrupted, indicating that the toxin targets the CPGs and central coordination, while peripheral coordination partially rescues the behavior in intact animals.

  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. PMID:19566347

  20. Invertebrate proenkephalin: delta opioid binding sites in leech ganglia and immunocytes.

    PubMed

    Salzet, M; Stefano, G B

    1997-09-12

    The leech Theromyzon tessulatum and the marine mussel Mytilus edulis immunocytes contain a mammalian-like proenkephalin molecule. The opioid precursor was purified by gel permeation chromatography, anti-Met- and Leu-enkephalin-affinity column separation and then by reversed-phase HPLC. The amino acid sequence analysis, determined by Edman degradation, enzymatic treatments and matrix assisted laser desorption time of flight. The structure of the leech proenkephalin material demonstrates considerable amino acid sequence similarity with amphibian proenkephalin (e.g. 25.4% with Xenopus laevis) but it is smaller, 15 kDa vs. 30 kDa. In contrast, Mytilus proenkephalin is not only larger (26 kDa) but it exhibits a higher sequence identity with guinea pig proenkephalin (50%). Both of the invertebrate materials possess Met-enkephalin and Leu-enkephalin in a ratio of 3:1 for Mytilus and 1:2 in the leech. They also contain Met-enkephalin-Arg-Gly-Leu and Met-enkephalin-Arg-Phe sequences that are flanked by dibasic amino acid residues, demonstrating cleavage sites. Furthermore, using sequence comparison with bovine proenkephalin A (209-237), enkelytin (FAEPLPSEEEGESYSKEVPEMEKRYGGFM), an antibacterial peptide is found in the proenkephalin of both animals and it exhibits a 98% sequence identity with mammalian material. Finally, opioid binding experiments demonstrate the presence in leech ganglia and immunocytes of delta1 and delta2 opioid receptor subtypes as also found human and Mytilus immune cells. This report constitutes the first complete biochemical characterization of mammalian proenkephalin in invertebrates, demonstrating its origin in simpler animals.

  1. Leech egg-laying-like hormone: structure, neuronal distribution and phylogeny.

    PubMed

    Salzet, M; Verger-Bocquet, M; Vandenbulcke, F; Van Minnen, J

    1997-10-01

    Cells immunoreactive to antisera specifically directed against Lymnaea stagnalis caudo dorsal cells egg-laying hormone (CDCH) or against alpha- and beta-peptides (CDCP), encoded on the egg-laying hormone precursor, were detected in central nervous system (CNS) of the rhynchobdellid leech Theromyzon tessulatum. A co-localization of the CDC-like hormone and CDC-like peptides was found in T. tessulatum as in L. stagnalis CNS. approximately 45 immunoreactive cells to the anti-CDCH were detected in leech brain but this number varies according to the stage of the animal life cycle, i.e. it reaches a maximum just before egg-laying while after it decreases to 2-3 cells. CDCH and alpha-CDCP epitopes recognized by anti-CDCH and anti-alpha-CDCP were contained in neurosecretory granules. Following an extensive purification, including HPGPC and reverse-phase HPLC, the CDC-like hormone contained in the T. tessulatum CNA was isolated. The sequence (GSGVSNGGTEMIQLSHIRERQRYWAQDNLRRRFLEK-amide) was established by a combination of automated Edman degradation, arginyl-endopeptidase digestion, electrospray mass spectrometry measurement and carboxypeptidase A treatment. The results demonstrate that the peptide recognized by the anti-CDCH in the leech CNS possesses 27.8, 37.2 and 47.2% sequence identity with Aplysia parvula, Lymnaea stagnalis and Aplysia californica ELH, respectively. This molecule was named the leech egg-laying-like hormone (L-ELH). The secondary structure prediction of the L-ELH and all mollusks ELH, revealed the existence of a conserved segment (segment 29-34) in a strong helicoidal bend that might be important for receptor recognition and/or activation. This finding constitutes the first biochemical characterization of an egg-laying hormone in other invertebrates than mollusks.

  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. PMID:15777919

  3. Immediate use of medicinal leeches to salvage venous congested reverse pedicled neurocutaneous flaps.

    PubMed

    Gideroglu, Kaan; Yildirim, Serkan; Akan, Mithat; Akoz, Tayfun

    2003-01-01

    Reverse pedicled neurocutaneous flaps have recently become popular for reconstructing soft tissue defects of the lower extremity. Venous congestion is a relatively common problem in these flaps in diabetic patients and those with electric burns, and this may cause partial or complete loss if capillary perfusion is not re-established urgently. We describe our experience of 13 neurocutaneous flaps, of which five developed venous congestion and were treated successfully with leeches placed immediately.

  4. Phylogeny and phylogeography of medicinal leeches (genus Hirudo): fast dispersal and shallow genetic structure.

    PubMed

    Trontelj, Peter; Utevsky, Serge Y

    2012-05-01

    Medicinal leeches (Hirudo spp.) are among the best-studied invertebrates in many aspects of their biology. Yet, relatively little is known about their biogeography, ecology and evolution. Previous studies found vast ranges but suggested low genetic diversity for some species. To examine this apparent contradiction, the phylogeny and phylogeography of the widespread Hirudo verbana, Hirudo medicinalis and Hirudo orientalis were investigated in a comparative manner. Populations from across their ranges in Europe, Asia Minor, the Caucasus and Central Asia, were analyzed by various phylogenetic and population genetic approaches using both mitochondrial (COI and 12S) and nuclear DNA sequences (ITS1, 5.8S and ITS2). The populations showed surprisingly little genetic differentiation despite vast ranges. The only clear structure was observed in H. verbana. This species is subdivided into an Eastern (southern Ukraine, North Caucasus, Turkey and Uzbekistan) and a Western phylogroup (Balkans and Italy). The two phylogroups do not overlap, suggesting distinct postglacial colonization from separate refugia. Leeches supplied by commercial facilities belong to the Eastern phylogroup of H. verbana; they originate from Turkey and the Krasnodar Territory in Russia, two leading areas of leech export. H. verbana and H. medicinalis have experienced recent rapid population growth and range expansion, while isolation by distance has shaped the genetic setup of H. orientalis. The habitat of the latter is patchy and scattered about inhospitable arid and alpine areas of Central Asia and Transcaucasia. Centuries of leech collecting and transport across Europe seem not to have affected the natural distribution of genetic diversity, as the observed patterns can be explained by a combination of historical factors and present day climatic influences.

  5. Developmentally regulated multisensory integration for prey localization in the medicinal leech.

    PubMed

    Harley, Cynthia M; Cienfuegos, Javier; Wagenaar, Daniel A

    2011-11-15

    Medicinal leeches, like many aquatic animals, use water disturbances to localize their prey, so they need to be able to determine if a wave disturbance is created by prey or by another source. Many aquatic predators perform this separation by responding only to those wave frequencies representing their prey. As leeches' prey preference changes over the course of their development, we examined their responses at three different life stages. We found that juveniles more readily localize wave sources of lower frequencies (2 Hz) than their adult counterparts (8-12 Hz), and that adolescents exhibited elements of both juvenile and adult behavior, readily localizing sources of both frequencies. Leeches are known to be able to localize the source of waves through the use of either mechanical or visual information. We separately characterized their ability to localize various frequencies of stimuli using unimodal cues. Within a single modality, the frequency-response curves of adults and juveniles were virtually indistinguishable. However, the differences between the responses for each modality (visual and mechanosensory) were striking. The optimal visual stimulus had a much lower frequency (2 Hz) than the optimal mechanical stimulus (12 Hz). These frequencies matched, respectively, the juvenile and the adult preferred frequency for multimodally sensed waves. This suggests that, in the multimodal condition, adult behavior is driven more by mechanosensory information and juvenile behavior more by visual. Indeed, when stimuli of the two modalities were placed in conflict with one another, adult leeches, unlike juveniles, were attracted to the mechanical stimulus much more strongly than to the visual stimulus.

  6. 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.

  7. Transmission of Haemogregarina balli from painted turtles to snapping turtles through the leech Placobdella ornata.

    PubMed

    Siddall, M E; Desser, S S

    2001-10-01

    Six leeches (Placobdella ornata) were allowed to feed on a painted turtle (Chrysemys picta marginata) infected with Haemogregarina balli and subjected to a period of diapause before being allowed to feed on 2 laboratory-reared snapping turtles (Chelydra serpentina). Weekly examination of thin blood films revealed infections of the turtles at 130 days postfeeding. These observations provide support for broad host specificity of hemogregarine parasites of chelonians. PMID:11695407

  8. Metabolism of angiotensins by head membranes of the leech Theromyzon tessulatum.

    PubMed

    Laurent, V; Salzet, M

    1996-04-15

    Angiotensins (angiotensin I, angiotensin II, angiotensin II-amide) have been isolated in leeches and such peptides are involved in diuresis in these animals. To explore possible inactivation mechanisms of these peptides, angiotensins were incubated with head membranes of the leech T. tessulatum. Membranes derived from head parts of this leech are very rich in peptidases. They contain endopeptidase-24.11-like enzyme (NEP-like) associated with a battery of exopeptidase. The way that angiotensins are degraded by the combined attack of these membrane peptidases has been investigated. The contribution of individual peptidases was assessed by adding inhibitors (phosphoramidon, captopril and amastatin) to the membrane fractions, when they were incubated with the peptides. In the case of angiotensin I, the primary attack was performed by a combined action of the NEP-like and the ACE-like enzymes, followed by aminopeptidase attacks. Angiotensin II and III were hydrolyzed by NEP-like enzyme at the same Tyr-Ile bond, whereas the N-terminal arginine residue of angiotensin III was removed by an arginyl aminopeptidase. These results show that angiotensins are efficiently degraded by membranes and that NEP-like enzyme plays a key role in this process.

  9. 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

  10. The leech: a novel invertebrate model for studying muscle regeneration and diseases.

    PubMed

    Grimaldi, Annalisa; Banfi, Serena; Bianchi, Cristiano; Gabriella, Greco; Tettamanti, Gianluca; Noonan, Douglas M; Valvassori, Roberto; de Eguileor, Magda

    2010-01-01

    We focused our studies on the leech, Hirudo medicinalis. This invertebrate has a relative anatomical simplicity and is a reliable model for studying a variety of basic events, such as tissue repair, which has a striking similarity with vertebrate responses. Hirudo is also a good invertebrate model to test the actions of drugs and gene products, since the responses evoked by the different stimuli are clear and easily detectable due to their small size and anatomical simplicity. Here we review the use of this invertebrate model to investigate muscle regeneration and the role of hematopoietic stem cells in this process. Our recent data, summarized in this review, demonstrate that the injection of an appropriate combination of the matrigel biopolymer supplemented with Vascular Endothelial Growth factor (VEGF) in the leech Hirudo medicinalis is a remarkably effective tool for isolating a specific population of hematopoietic/endothelial precursor cells, which in turn can differentiate in muscle cells. Thus leeches can be considered as a new emerging model for studying endothelial and hematopoietic precursors cells involved in muscle post-natal growth and regeneration processes. PMID:20041825

  11. Characterization of central axon terminals of putative stretch receptors in leeches.

    PubMed

    Fan, Ruey-Jane; Friesen, W Otto

    2006-01-10

    Sensory feedback from stretch receptors, neurons that detect position or tension, is crucial for generating normal, robust locomotion. Among the eight pairs of putative stretch receptors associated with longitudinal muscles in midbody segments of medicinal leeches, only the ventral stretch receptor has been characterized in detail. To achieve the identification of all such receptors, we penetrated large axons in the nerve roots of nerve cords from adult leeches with dye-filled (Alexa Fluor hydrazide) electrodes. We identified the terminal arborizations of two additional putative stretch receptors with axons in anterior nerve roots and four more such receptors with axons in posterior roots of midbody ganglia. The axons are nonspiking and are individually identifiable by their entry point into the CNS; their projections within the neuropile; the pattern, extent, and orientation of their terminal branches; and the characteristics of small "spike-like" events. At least two of these axons undergo membrane potential oscillations that are phase locked to the swimming rhythm expressed in nerve cord-body wall preparations and, at a different phase angle, also in isolated nerve cords. Thus the membrane potentials of at least two axons are phasically modulated by the periphery and hence could provide cycle-by-cycle sensory input to coordinate swimming activity. One of these neurons has a soma associated with the dorsal body wall and hence is a putative stretch receptor in dorsal longitudinal muscle. Thus the traveling body wave expressed by swimming leeches may be regulated by sensory feedback from both ventral and dorsal longitudinal muscles.

  12. De novo transcriptome assembly databases for the central nervous system of the medicinal leech

    PubMed Central

    Hibsh, Dror; Schori, Hadas; Efroni, Sol; Shefi, Orit

    2015-01-01

    The study of non-model organisms stands to benefit greatly from genetic and genomic data. For a better understanding of the molecular mechanisms driving neuronal development, and to characterize the entire leech Hirudo medicinalis central nervous system (CNS) transcriptome we combined Trinity for de-novo assembly and Illumina HiSeq2000 for RNA-Seq. We present a set of 73,493 de-novo assembled transcripts for the leech, reconstructed from RNA collected, at a single ganglion resolution, from the CNS. This set of transcripts greatly enriches the available data for the leech. Here, we share two databases, such that each dataset allows a different type of search for candidate homologues. The first is the raw set of assembled transcripts. This set allows a sequence-based search. A comprehensive analysis of which revealed 22,604 contigs with high e-values, aligned versus the Swiss-Prot database. This analysis enabled the production of the second database, which includes correlated sequences to annotated transcript names, with the confidence of BLAST best hit. PMID:25977819

  13. Decision points: the factors influencing the decision to feed in the medicinal leech.

    PubMed

    Gaudry, Quentin; Kristan, William B

    2012-01-01

    The decision to feed is a complex task that requires making several small independent choices. Am I hungry? Where do I look for food? Is there something better I'd rather be doing? When should I stop? With all of these questions, it is no wonder that decisions about feeding depend on several sensory modalities and that the influences of these sensory systems would be evident throughout the nervous system. The leech is uniquely well suited for studying these complicated questions due to its relatively simple nervous system, its exceptionally well-characterized behaviors and neural circuits, and the ease with which one can employ semi-intact preparations to study the link between physiology and decision-making. We will begin this review by discussing the cellular substrates that govern the decision to initiate and to terminate a bout of feeding. We will then discuss how feeding temporarily blocks competing behaviors from being expressed while the animal continues to feed. Then we will review what is currently known about how feeding affects long-term behavioral choices of the leech. Finally, we conclude with a short discussion of the advantages of the leech's decision-making circuit's design and how this design might be applicable to all decision circuits. PMID:22783162

  14. Angiotensin-converting enzyme inhibition studies by natural leech inhibitors by capillary electrophoresis and competition assay.

    PubMed

    Deloffre, Laurence; Sautiere, Pierre-Eric; Huybrechts, Roger; Hens, Korneel; Vieau, Didier; Salzet, Michel

    2004-06-01

    A protocol to follow the processing of angiotensin I into angiotensin II by rabbit angiotensin-converting enzyme (ACE) and its inhibition by a novel natural antagonist, the leech osmoregulator factor (LORF) using capillary zonal electrophoresis is described. The experiment was carried out using the Beckman PACE system and steps were taken to determine (a) the migration profiles of angiotensin and its yielded peptides, (b) the minimal amount of angiotensin II detected, (c) the use of different electrolytes and (d) the concentration of inhibitor. We demonstrated that LORF (IPEPYVWD), a neuropeptide previously found in leech brain, is able to inhibit rabbit ACE with an IC(50) of 19.8 micro m. Interestingly, its cleavage product, IPEP exhibits an IC(50) of 11.5 micro m. A competition assay using p-benzoylglycylglycylglycine and insect ACE established that LORF and IPEP fragments are natural inhibitors for invertebrate ACE. Fifty-four percent of insect ACE activity is inhibited with 50 micro m IPEP and 35% inhibition with LORF (25 mm). Extending the peptide at both N- and C-terminus (GWEIPEPYVWDES) and the cleavage of IPEP in IP abolished the inhibitory activity of both peptides. Immunocytochemical data obtained with antisera raised against LORF and leech ACE showed a colocalization between the enzyme and its inhibitor in the same neurons. These results showed that capillary zonal electrophoresis is a useful technique for following enzymatic processes with small amounts of products and constitutes the first evidence of a natural ACE inhibitor in invertebrates.

  15. 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.

  16. 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

  17. 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.

  18. Morphological and molecular characterization of a new species of leech (Glossiphoniidae, Hirudinida): Implications for the health of its imperiled amphibian host (Cryptobranchus alleganiensis)

    PubMed Central

    Hopkins, William A.; Moser, William E.; Garst, David W.; Richardson, Dennis J.; Hammond, Charlotte I.; Lazo-Wasem, Eric A.

    2014-01-01

    Abstract The hellbender (Cryptobranchus alleganiensis) is among the most intriguing and imperiled amphibians in North America. Since the 1970s and 80s, western populations of the Ozark and eastern subspecies in Missouri have declined by nearly 80%. As a result of population declines, the Ozark hellbender was recently federally protected as an endangered species, and the eastern subspecies was granted protection under CITES. Although habitat degradation is probably the biggest threat to hellbender populations, recent evidence suggests that pathogens including chytrid fungus and “flesh-eating” bacteria may also contribute to declines in Ozark hellbenders. Leeches, which are very common on Ozark hellbenders, have recently been implicated as possible vectors of disease among Ozark hellbenders but have not been described in eastern hellbenders or outside of Missouri and Arkansas. We discovered a population of leeches on eastern hellbenders in southwest Virginia and confirmed that the species of leech is within the genus Placobdella, but is morphologically and genetically distinct from all previously described leech species. We named the new species Placobdella appalachiensis sp. n. Moser and Hopkins, based on the mountainous region in which it was discovered. Our surveys over a three consecutive year period suggested that this leech species may be patchily distributed and/or have a narrow geographic range. We consistently detected leeches at one site (mean prevalence in 80 hellbenders = 27.5%; median intensity = 3.0 leeches per parasitized hellbender [range 1 – >250 leeches]) during three years of surveys, but we never found leeches in any of our other seven study sites in two streams (mean prevalence in 139 hellbenders = 0%). We found a significant positive relationship between hellbender body size and the intensity of parasitism, and we suggest the possibility that the behavioral ecology of adults leading up to reproduction may increase their encounter rates

  19. Morphological and molecular characterization of a new species of leech (Glossiphoniidae, Hirudinida): Implications for the health of its imperiled amphibian host (Cryptobranchus alleganiensis).

    PubMed

    Hopkins, William A; Moser, William E; Garst, David W; Richardson, Dennis J; Hammond, Charlotte I; Lazo-Wasem, Eric A

    2014-01-01

    The hellbender (Cryptobranchus alleganiensis) is among the most intriguing and imperiled amphibians in North America. Since the 1970s and 80s, western populations of the Ozark and eastern subspecies in Missouri have declined by nearly 80%. As a result of population declines, the Ozark hellbender was recently federally protected as an endangered species, and the eastern subspecies was granted protection under CITES. Although habitat degradation is probably the biggest threat to hellbender populations, recent evidence suggests that pathogens including chytrid fungus and "flesh-eating" bacteria may also contribute to declines in Ozark hellbenders. Leeches, which are very common on Ozark hellbenders, have recently been implicated as possible vectors of disease among Ozark hellbenders but have not been described in eastern hellbenders or outside of Missouri and Arkansas. We discovered a population of leeches on eastern hellbenders in southwest Virginia and confirmed that the species of leech is within the genus Placobdella, but is morphologically and genetically distinct from all previously described leech species. We named the new species Placobdella appalachiensis sp. n. Moser and Hopkins, based on the mountainous region in which it was discovered. Our surveys over a three consecutive year period suggested that this leech species may be patchily distributed and/or have a narrow geographic range. We consistently detected leeches at one site (mean prevalence in 80 hellbenders = 27.5%; median intensity = 3.0 leeches per parasitized hellbender [range 1 - >250 leeches]) during three years of surveys, but we never found leeches in any of our other seven study sites in two streams (mean prevalence in 139 hellbenders = 0%). We found a significant positive relationship between hellbender body size and the intensity of parasitism, and we suggest the possibility that the behavioral ecology of adults leading up to reproduction may increase their encounter rates with parasites. We

  20. Interaction of leech neurons with topographical gratings: comparison with rodent and human neuronal lines and primary cells

    PubMed Central

    Tonazzini, Ilaria; Pellegrini, Monica; Pellegrino, Mario; Cecchini, Marco

    2014-01-01

    Controlling and improving neuronal cell migration and neurite outgrowth are critical elements of tissue engineering applications and development of artificial neuronal interfaces. To this end, a promising approach exploits nano/microstructured surfaces, which have been demonstrated to be capable of tuning neuronal differentiation, polarity, migration and neurite orientation. Here, we investigate the neurite contact guidance of leech neurons on plastic gratings (GRs; anisotropic topographies composed of alternating lines of grooves and ridges). By high-resolution microscopy, we quantitatively evaluate the changes in tubulin cytoskeleton organization and cell morphology and in the neurite and growth cone development. The topography-reading process of leech neurons on GRs is mediated by filopodia and is more responsive to 4-µm-period GRs than to smaller period GRs. Leech neuron behaviour on GRs is finally compared and validated with several other neuronal cells, from murine differentiated embryonic stem cells and primary hippocampal neurons to differentiated human neuroblastoma cells. PMID:24501675

  1. 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.

  2. 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.

  3. Phylogenomics of Reichenowia parasitica, an Alphaproteobacterial Endosymbiont of the Freshwater Leech Placobdella parasitica

    PubMed Central

    Kvist, Sebastian; Narechania, Apurva; Oceguera-Figueroa, Alejandro; Fuks, Bella; Siddall, Mark E.

    2011-01-01

    Although several commensal alphaproteobacteria form close relationships with plant hosts where they aid in (e.g.,) nitrogen fixation and nodulation, only a few inhabit animal hosts. Among these, Reichenowia picta, R. ornata and R. parasitica, are currently the only known mutualistic, alphaproteobacterial endosymbionts to inhabit leeches. These bacteria are harbored in the epithelial cells of the mycetomal structures of their freshwater leech hosts, Placobdella spp., and these structures have no other obvious function than housing bacterial symbionts. However, the function of the bacterial symbionts has remained unclear. Here, we focused both on exploring the genomic makeup of R. parasitica and on performing a robust phylogenetic analysis, based on more data than previous hypotheses, to test its position among related bacteria. We sequenced a combined pool of host and symbiont DNA from 36 pairs of mycetomes and performed an in silico separation of the different DNA pools through subtractive scaffolding. The bacterial contigs were compared to 50 annotated bacterial genomes and the genome of the freshwater leech Helobdella robusta using a BLASTn protocol. Further, amino acid sequences inferred from the contigs were used as queries against the 50 bacterial genomes to establish orthology. A total of 358 orthologous genes were used for the phylogenetic analyses. In part, results suggest that R. parasitica possesses genes coding for proteins related to nitrogen fixation, iron/vitamin B translocation and plasmid survival. Our results also indicate that R. parasitica interacts with its host in part by transmembrane signaling and that several of its genes show orthology across Rhizobiaceae. The phylogenetic analyses support the nesting of R. parasitica within the Rhizobiaceae, as sister to a group containing Agrobacterium and Rhizobium species. PMID:22132238

  4. The medicinal leech genome encodes 21 innexin genes: different combinations are expressed by identified central neurons.

    PubMed

    Kandarian, Brandon; Sethi, Jasmine; Wu, Allan; Baker, Michael; Yazdani, Neema; Kym, Eunice; Sanchez, Alejandro; Edsall, Lee; Gaasterland, Terry; Macagno, Eduardo

    2012-03-01

    Gap junctional proteins are important components of signaling pathways required for the development and ongoing functions of all animal tissues, particularly the nervous system, where they function in the intracellular and extracellular exchange of small signaling factors and ions. In animals whose genomes have been sufficiently sequenced, large families of these proteins, connexins, pannexins, and innexins, have been found, with 25 innexins in the nematode Caenorhabditis elegans Starich et al. (Cell Commun Adhes 8: 311-314, 2001) and at least 37 connexins in the zebrafish Danio rerio Cruciani and Mikalsen (Biol Chem 388:253-264, 2009). Having recently sequenced the medicinal leech Hirudo verbana genome, we now report the presence of 21 innexin genes in this species, nine more than we had previously reported from the analysis of an EST-derived transcriptomic database Dykes and Macagno (Dev Genes Evol 216: 185-97, 2006); Macagno et al. (BMC Genomics 25:407, 2010). Gene structure analyses show that, depending on the leech innexin gene, they can contain from 0 to 6 introns, with closely related paralogs showing the same number of introns. Phylogenetic trees comparing Hirudo to another distantly related leech species, Helobdella robusta, shows a high degree of orthology, whereas comparison to other annelids shows a relatively low level. Comparisons with other Lophotrochozoans, Ecdyzozoans and with vertebrate pannexins suggest a low number (one to two) of ancestral innexin/pannexins at the protostome/deuterostome split. Whole-mount in situ hybridization for individual genes in early embryos shows that ∼50% of the expressed innexins are detectable in multiple tissues. Expression analyses using quantitative PCR show that ∼70% of the Hirudo innexins are expressed in the nervous system, with most of these detected in early development. Finally, quantitative PCR analysis of several identified adult neurons detects the presence of different combinations of innexin genes

  5. Leeches of the genus Helobdella as model organisms for Evo-Devo studies.

    PubMed

    Kutschera, Ulrich; Weisblat, David A

    2015-12-01

    Model organisms are important tools in modern biology and have been used elucidate mechanism underlying processes, such as development, heredity, neuronal signaling, and phototropism, to name but a few. In this context, the use of model organisms is predicated on uncovering evolutionarily conserved features of biological processes in the expectation that the findings will be applicable to organisms that are either inaccessible or intractable for direct experimentation. For the most part, particular species have been adapted as model organisms because they can be easily reared and manipulated in the laboratory. In contrast, a major goal in the field of evolutionary developmental biology (Evo-Devo) is to identify and elucidate the differences in developmental processes among species associated with the dramatic range of body plans among organisms, and how these differences have emerged over time in various branches of phylogeny. At first glance then, it would appear that the concept of model organisms for Evo-Devo is oxymoronic. In fact, however, laboratory-compatible, experimentally tractable species are of great use for Evo-Devo, subject to the condition that the ensemble of models investigated should reflect the range of taxonomic diversity, and for this purpose glossiphoniid leeches are useful. Four decades ago (1975), leeches of the species-rich genus Helobdella (Lophotrochozoa; Annelida; Clitellata; Hirudinida; Glossiphoniidae) were collected in Stow Lake, Golden Gate Park, San Francisco, CA (USA). These and other Helobdella species may be taken as Evo-Devo models of leeches, clitellate annelids, and the super-phylum Lophotrochozoa. Here we depict/discuss the biology/taxonomy of these Evo-Devo systems, and the challenges of identifying species within Helobdella. In addition, we document that H. austinensis has been established as a new model organism that can easily be cultivated in the laboratory. Finally, we provide an updated scheme illustrating the unique

  6. Phylogenomics of Reichenowia parasitica, an alphaproteobacterial endosymbiont of the freshwater leech Placobdella parasitica.

    PubMed

    Kvist, Sebastian; Narechania, Apurva; Oceguera-Figueroa, Alejandro; Fuks, Bella; Siddall, Mark E

    2011-01-01

    Although several commensal alphaproteobacteria form close relationships with plant hosts where they aid in (e.g.,) nitrogen fixation and nodulation, only a few inhabit animal hosts. Among these, Reichenowia picta, R. ornata and R. parasitica, are currently the only known mutualistic, alphaproteobacterial endosymbionts to inhabit leeches. These bacteria are harbored in the epithelial cells of the mycetomal structures of their freshwater leech hosts, Placobdella spp., and these structures have no other obvious function than housing bacterial symbionts. However, the function of the bacterial symbionts has remained unclear. Here, we focused both on exploring the genomic makeup of R. parasitica and on performing a robust phylogenetic analysis, based on more data than previous hypotheses, to test its position among related bacteria. We sequenced a combined pool of host and symbiont DNA from 36 pairs of mycetomes and performed an in silico separation of the different DNA pools through subtractive scaffolding. The bacterial contigs were compared to 50 annotated bacterial genomes and the genome of the freshwater leech Helobdella robusta using a BLASTn protocol. Further, amino acid sequences inferred from the contigs were used as queries against the 50 bacterial genomes to establish orthology. A total of 358 orthologous genes were used for the phylogenetic analyses. In part, results suggest that R. parasitica possesses genes coding for proteins related to nitrogen fixation, iron/vitamin B translocation and plasmid survival. Our results also indicate that R. parasitica interacts with its host in part by transmembrane signaling and that several of its genes show orthology across Rhizobiaceae. The phylogenetic analyses support the nesting of R. parasitica within the Rhizobiaceae, as sister to a group containing Agrobacterium and Rhizobium species. PMID:22132238

  7. 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. PMID:26430464

  8. Forgotten digital tourniquet: salvage of an ischaemic finger by application of medicinal leeches.

    PubMed

    Durrant, C; Townley, W A; Ramkumar, S; Khoo, C T K

    2006-09-01

    Individual finger tourniquets are appropriate to the management of a wide range of conditions presenting to an accident and emergency department. They are simpler and more comfortable to use than upper arm pneumatic tourniquets and commercially available digital tourniquets are not readily available in the accident and emergency unit. However, if a finger tourniquet is overlooked, ischaemia of the digit results, and gangrene may follow if the problem is not defused early enough, leading to potential disaster. We present one case where a digit was salvaged after 4 days of tourniquet application, using medicinal leeches.

  9. 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.

  10. More than just one: multiplicity of Hirudins and Hirudin-like Factors in the Medicinal Leech, Hirudo medicinalis.

    PubMed

    Müller, Christian; Mescke, Katharina; Liebig, Stephanie; Mahfoud, Hala; Lemke, Sarah; Hildebrandt, Jan-Peter

    2016-02-01

    Blood-sucking leeches like the medicinal leech, Hirudo medicinalis, have been used for medical purposes since ancient times. During feeding, medicinal leeches transfer a broad range of bioactive substances into the host's wound to prevent premature hemostasis and blood coagulation. Hirudin is probably the best known of these substances. Despite its long history of investigation, recombinant production and clinical use, there still exist conflicting data regarding the primary structure of hirudin. Entirely unclear is the potential biological significance of three different subtypes and many isoforms of hirudins that have been characterized so far. Furthermore, there is only incomplete information on their cDNA sequences and no information at all on gene structures and DNA sequences are available in the databases. Our efforts to fill these gaps revealed the presence of multiple hirudin-encoding genes in the genome of Hirudo medicinalis. We have strong evidence for the expression of all three subtypes of hirudin within individual leeches and for the expression of additional hirudins or hirudin-like factors that may have different biological functions and may be promising candidates for new drugs.

  11. Culture-independent characterization of the digestive-tract microbiota of the medicinal leech reveals a tripartite symbiosis.

    PubMed

    Worthen, Paul L; Gode, Cindy J; Graf, Joerg

    2006-07-01

    Culture-based studies of the microbial community within the gut of the medicinal leech have typically been focused on various Aeromonas species, which were believed to be the sole symbiont of the leech digestive tract. In this study, analysis of 16S rRNA gene clone libraries confirmed the presence of Aeromonas veronii and revealed a second symbiont, clone PW3, a novel member of the Rikenellaceae, within the crop, a large compartment where ingested blood is stored prior to digestion. The diversity of the bacterial community in the leech intestinum was determined, and additional symbionts were detected, including members of the alpha-, gamma-, and delta-Proteobacteria, Fusobacteria, Firmicutes, and Bacteroidetes. The relative abundances of the clones suggested that A. veronii and the novel clone, PW3, also dominate the intestinum community, while other clones, representing transient organisms, were typically present in low numbers. The identities of these transients varied greatly between individual leeches. Neither time after feeding nor feeding on defibrinated blood caused a change in identity of the dominant members of the microbial communities. Terminal restriction fragment length polymorphism analysis was used to verify that the results from the clone libraries were representative of a larger data set. The presence of a two-member bacterial community in the crop provides a unique opportunity to investigate both symbiont-symbiont and symbiont-host interactions in a natural model of digestive-tract associations.

  12. 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

  13. 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. PMID:27667513

  14. Biochemical properties of the angiotensin-converting-like enzyme from the leech Theromyzon tessulatum.

    PubMed

    Laurent, V; Salzet, M

    1996-01-01

    This article reports the evidence and the biochemical properties of an angiotensin-converting (ACE)-like enzyme from head parts of the leech Theromyzon tessulatum. After solubilization from membranes with Triton X-114, the ACE-like enzyme was purified from the detergent-poor fraction. Four steps of purification including gel permeation and anion exchange chromatographies followed by a reversed-phase HPLC were needed. This poor glycosylated peptidyl dipeptidase (of ca. 120 kDa) hydrolyzes, at pH 8.4 and at 37 degrees C, the Phe8-His9 bond of angiotensin I with a high catalytic activity (i.e., K(m): 830 microM and Kcat/K(m): 153 s-1 mM-1). The hydrolysis of angiotensin I is inhibitable at 80% by captopril (IC50 = 175 nM) and lisinopril (IC50 = 35 nM). This activity is strictly dependent on the presence of NaCl and is increased by Zn2+. This zinc metallopeptidase also attacks peptides that have in their sequence either Gly-His, Gly-Phe, or Phe-His bond [e.g., enkephalins (Kcat/K(m): 12 s-1 mM-1) or bradykinin (Kcat/K(m): 2200 s-1 mM-1]. Taken together, these arguments are consistent with an ACE-like activity implicated in metabolism of angiotensins and bradykinin in leeches.

  15. Biochemical identification and ganglionic localization of leech angiotensin-converting enzymes.

    PubMed

    Vandenbulcke, F; Laurent, V; Verger-Bocquet, M; Stefano, G B; Salzet, M

    1997-10-01

    We demonstrate the presence of a membrane and soluble form of leech Theromyzon tessulatum angiotensin-converting enzyme (ACE). Four steps in the purification of this enzyme include gel-permeation, captopril-sepharose affinity and anion-exchange chromatography followed by a reverse-phase HPLC. The peptidyl dipeptidases (of approximately 120 and approximately 100 kDa) are glycosylated enzymes hydrolysing the Phe8-His9 bond of angiotensin I, exhibiting the same specific activity and Km whereas the soluble ACE exhibits a higher catalytic efficiency. This hydrolysis is inhibited by the ACE-specific antagonist captopril. Western blot analysis of a polyclonal antiserum raised against the first 11 amino-acid residues of the membrane ACE and the N-terminal sequence of the soluble molecule also demonstrates the presence of two ACE enzymes. Anti-ACE immunocytochemistry also supports the presence of two forms of ACE. This material is found in neurons and glia. We demonstrate for the first time the cellular localization and biochemical characterization of ACEs in the central nervous system of an invertebrate. Thus, the leech brain may represent a simple model for the study of these enzymes.

  16. The complex dynamic network of microtubule and microfilament cytasters of the leech zygote.

    PubMed

    Cantillana, V; Urrutia, M; Ubilla, A; Fernández, J

    2000-12-01

    The organization of the cytoskeleton in the early first interphase zygote and its involvement in organelle redistribution were studied in the glossiphoniid leech Theromyzon trizonare by confocal and electron microscopy, immunofluorescence, and time-lapse video imaging after microinjection of labeled tubulin and/or actin and loading with a mitotracker. The cytoskeleton consists of an inner or endoplasmic and an outer or ectoplasmic domain. The inner domain consists of a monaster whose fibers retract from the zygote periphery by the end of the early first interphase. The outer domain is built upon a network of microtubules and microfilaments cytasters. Short pulses of microinjected labeled actin or tubulin and Taxol treatment demonstrate that cytasters are centers of microtubule and microfilament nucleation. Immunostaining with anti-centrophilin, anti-BX-63, and anti-AH-6 indicates that the network of cytasters includes centrosomal antigens. Cytasters move in an orderly fashion at speeds of 0.5-2 micrometer/min, in an energy-dependent process retarded and finally blocked by the ATP analogue AMP-PNP and high concentrations of Taxol. Colliding cytasters fuse and form larger cytoskeletal nucleation centers. The leech zygote is a highly compartmentalized cell whose cytasters function as articulated components of a very dynamic cytoskeletal system engaged in bulk transportation of organelles during ooplasmic segregation. PMID:11087633

  17. Pentylenetetrazol-induced seizure-like behavior and neural hyperactivity in the medicinal leech.

    PubMed

    Hahn, Elizabeth; Burrell, Brian

    2015-01-01

    This study examined the capacity of a known pro-epileptic drug, pentylenetetrazol (PTZ), to elicit seizure-like activity in the medicinal leech, Hirudo verbana. During in vivo experiments, PTZ elicited increased motor activity in a concentration-dependent manner with the highest concentration (10 mM) eliciting episodes of highly uncoordinated exploratory and swimming behavior. Co-application of the anti-epileptic drug, phenytoin, failed to reduce the absolute amount of PTZ-induced motor behavior, but was able to prevent expression of abnormal exploratory and swimming behaviors. During in vitro experiments in which extracellular recordings of connective nerve activity were made, bath application of 1 μM PTZ in Mg(2+)-free saline elicited a significant increase in spontaneous activity. This PTZ-induced increase in activity was completely inhibited by phenytoin. Interestingly, PTZ-induced hyperactivity was also blocked by co-application of the endocannabinoid 2-arachidonoyl glycerol and the selective serotonin re-uptake inhibitor (SSRI) fluoxetine. These findings suggest that the leech can be a useful system in which to study potential anti-epileptic treatments.

  18. 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.

  19. 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.

  20. Involvement of nitric oxide through endocannabinoids release in microglia activation during the course of CNS regeneration in the medicinal leech.

    PubMed

    Arafah, Karim; Croix, Dominique; Vizioli, Jacopo; Desmons, Annie; Fournier, Isabelle; Salzet, Michel

    2013-04-01

    The medicinal leech is notable for its capacity to regenerate its central nervous system (CNS) following mechanical trauma. Using an electrochemical nitric oxide (NO)-selective electrode to measure NO levels, we found that the time course of NO release in the injured leech CNS is partially under the control of endocannabinoids, namely, N-arachidonyl ethanolamide (AEA) and 2-arachidonyl glycerol (2-AG). Relative quantification of these endocannabinoids was performed by stable isotope dilution (2AGd8 and AAEd8) coupled to mass spectrometry in course of regeneration process or adenosine triphosphate (ATP) treatment. Data show that 2-AG levels rose to a maximum about 30 min after injury or ATP treatment, and returned to baseline levels 4 h after injury. In same conditions, AEA levels also rapidly (within 5 min) dropped after injury or ATP treatment to the nerve cord, but did not fully return to baseline levels within 4 h of injury. In correlation with these data, chemoattraction activities of endocannabinoids on isolated leech microglial cells have been shown in vitro and in vivo reflecting that control over NO production is accompanied by the controlled chemoattraction of microglia directed from the periphery to the lesion site for neuronal repair purposes. Taken together, our results show that in the leech, after injury concurrent with ATP production, purinergic receptor activation, NO production, microglia recruitment, and accumulation to lesion site, a fine imbalance occurs in the endocannabinoid system. These events can bring explanations about the ability of the leech CNS to regenerate after a trauma and the key role of endocannabinoids in this phenomenon. PMID:23355252

  1. Novel genotypes of Trypanosoma binneyi from wild platypuses (Ornithorhynchus anatinus) and identification of a leech as a potential vector.

    PubMed

    Paparini, Andrea; Macgregor, James; Irwin, Peter J; Warren, Kristin; Ryan, Una M

    2014-10-01

    Little is known about the prevalence and pathogenesis of trypanosomes in Australian monotremes, and few genetic characterisation studies have been conducted with these haemoparasites. During the present investigation, molecular and microscopic methods were used to screen peripheral blood (n=28) and ectoparasites (n=10 adult ticks; n=5 tick nymphs; n=1 leech; and n>500 tick eggs) collected from wild Tasmanian platypuses (Ornithorhynchus anatinus), for the presence of trypanosomatid-specific DNA and/or trypomastigotes. The genes for the small ribosomal subunit RNA (18S rDNA) and glycosomal glyceraldehyde phosphate dehydrogenase (gGAPDH) were amplified and sequenced, prior to conducting phylogenetic analyses. The detection rate of the parasite-specific 18S rDNA in platypus blood was 85.7% (n=24/28), and the leech was also positive at both loci. Microscopically, high parasitaemia and the presence of abundant trypomastigotes, morphologically consistent with Trypanosoma binneyi Mackerras (1959), were observed in the blood films. Phylogenetic analyses at the 18S locus revealed the existence of four trypanosomatid-like genotypes, with variable similarity to two previously-described genotypes of T. binneyi (range of genetic p-distance: 0.0-0.5%). For the gGAPDH locus, for which only one T. binneyi sequence is available in GenBank, three genotypes closely related T. binneyi were identified (range of genetic p-distance: 0.1-0.4%). The leech-derived trypanosome isolate was virtually identical (at the two loci studied) to the other parasites sequenced from infected platypuses; however, the molecular or morphological identification of the leech species was not possible. Although further studies are required, the molecular detection of trypanosomes in an aquatic leech removed from a platypus, suggests the possibility that these haematophagous hirudineans may be a vector for T. binneyi (and closely related genotypes). PMID:25045852

  2. 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

  3. OA01.40. A clinical study to evaluate the efficacy of leech therapy and panchatikta ghrita in the management of psoriasis)

    PubMed Central

    Gond, Pushpa; Rani, Rekha; Shringi, M. K.

    2012-01-01

    Purpose: Modern medical science treats psoriasis with PUVA, corticosteroid, anti-mitotic drugs which gives serious side effects like liver and kindney failure etc. There is a need to discover safe and effective medicine without any side effects for Psoriasis and the role of Leech Therapy (Shodhan) and Panchatikta Ghrita (Shaman Karma) is evaluated in this study. Method: 30 patients were included who matched the clinical signs and symptoms of psoriasis. These patients were randomised into three groups. Group A Only on leech therapy, Group B-Only on panchatikta ghrita and Group C On both leech therapy and panchatikta ghrita Result: Group A showed 45% improvement and group B showed 47% improvement, while group C reported 65% improvement. Conclusion: It can be concluded that shodan(leech application) along with shaman (panchatikta ghrita) is effective in the management of psoriasis as it is safe, cost effective and free from any side effects.

  4. Laboratory and field tests of the effectiveness of the lemon-eucalyptus extract, Citridiol, as a repellent against land leeches of the genus Haemadipsa (Haemadipsidae).

    PubMed

    Kirton, L G

    2005-10-01

    Citridiol is an extract of the leaves of Corymbia citriodora (Myrtaceae), the lemon eucalyptus, and mostly consists of p-menthane-3,8-diol isomers. The effectiveness of this extract as a repellent against land leeches of the genus Haemadipsa (Haemadipsidae), primarily H. sylvestris, was tested in the laboratory and field, in Peninsular Malaysia. The formulation tested, Mosi-guard Natural spray, contained 40% (w/w) Citridiol in a base of ethanol, water and isopropanol. In the laboratory test, specimens of H. sylvestris that were placed within moist, untreated arenas enclosed by treated paper rings made numerous attempts to cross the rings but were prevented or delayed from crossing over, in a dose-dependent manner. Mortality was high among the leeches that attempted to cross over the paper rings that had been sprayed to saturation point but low among the leeches that attempted to cross over paper rings that had only been partially treated, with a droplet-spray. The field study was carried out using indices that were formulated to reflect the severity of leech attack and the degree of repellency. Heavy or moderate spraying of footwear and trouser legs (tucked into socks) not only gave complete protection against bites by H. sylvestris and H. picta but also provided high enough repellency to keep the treated footwear virtually free of leeches. Even a light spray greatly reduced the numbers of leeches on footwear and delayed their progression toward biting the test subjects, although it failed to prevent bites completely. There was no decline in the repellency of the Citridiol when hourly assessments were made over a 6-h test period in the field. The results of the study show that Citridiol is highly repellent as well as toxic to leeches, and can be effectively used to prevent leech bites in the field. PMID:16212803

  5. Peptides from two sanguinovorous leeches analyzed by ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometric detector

    PubMed Central

    Xiao, Ling; Nie, Jing; Li, Danping; Chen, Keli

    2015-01-01

    Background: Hirudo nipponica Whitman and Poecilobdella manillensis Lesson fall into the family of Hirudinidae Whitman, both of them are sanguinovorous leeches and used a anticoagulant medicines in China. Their medicinal parts are the dried bodies. However, the peptides in the dried body of the two leeches have not been very clear up to now. Objective: To analyze the peptides from two sanguinovorous leeches, H. nipponica and P. manillensis. Materials and Methods: In this article it is reported that the peptides were obtained from anticoagulant active extracted parts of dried bodies of the two leeches and their molecular weights were analyzed by ultra-performance liquid chromatography with electrospray ionization quadrupole time-of-flight mass spectrometry mass spectrometric detector online. Results: Three peptide components were identified from H. nipponica with their molecular weight separately 14998, 15988, and 15956, six peptide components were identified from P. manillensis with molecular weight 9590, 13642, 14998, 17631, 15988, and 16567. Two of peptides from P. manillensis have the same molecular weight 14998 and 15988 as that in H. nipponica. Conclusion: And the two peptides are the main peaks in the base peak ion chromatogram because they occupied a large ratio of total base peak area. Hence the composition of the extracted active part of the two leeches are very close, difference is in that the extract of P. manillensis has more small peptide peaks, but the extract of H. nipponica has not. Furthermore, the tryptic digestion hydrolysates of the extracted active part of each sample were analyzed and the results showed that there were four peaks which only exist in P. manillensis, but not in Hirudo nipponia. They may be the identified peak between the two leeches. This work support the viewpoint that P. manillensis can be used as a medicinal leech as H. nipponia and these peptide components of dried bodies of the two species leeches are a basis for their

  6. Isolation and structural characterization of enkephalins in the brain of the rhynchobdellid leech Theromyzon tessulatum.

    PubMed

    Salzet, M; Bulet, P; Verger-Bocquet, M; Malecha, J

    1995-01-01

    This paper reports the purification of four peptides related to enkephalins from the brain of the leech Theromyzon tessulatum. After reverse-phase HPLC purification, the sequence of the enkephalins (YGGFM, YGGFL, FM, FL) was established by a combination of automated Edman degradation, electrospray mass spectrometry measurement, and co-elution experiments in reverse-phase HPLC with synthetic peptides. ELISA titrations performed on each purified peptide indicated that the major amount was borne by the leucine-enkephalin. The ratio of leucine-enkephalin and methionine-enkephalin of 2:1 is in line with previous immunocytochemical data obtained on T. tessulatum brains. The presence of enkephalins in T. tessulatum, an animal belonging to the oldest group of coelomate metazoans (the Annelida) establishes the very ancient phylogenetic origin of opioids and their conservation in the course of evolution.

  7. Isolation of a renin-like enzyme from the leech Theromyzon tessulatum.

    PubMed

    Laurent, V; Salzet, M

    1995-01-01

    This article reports the purification of a renin-like enzyme (an aspartyl protease) from head parts of the leech Theromyzon tessulatum. After four steps of purification including gel permeation and anion exchange chromatographies followed by reversed-phase HPLC, this enzyme was purified to homogeneity. The renin-like enzyme (of 32 kDa) hydrolyses at neutral pH and at 37 degrees C, the Leu10-Leu11 bond of synthetic porcine angiotensinogen tetradecapeptide yielding the angiotensin I and the Leu11-Val12-Tyr13-Ser14 peptide as products, with a specific activity of 1.35 pmol AI/min/mg (Km 22 microM; Kcat 2.7). The hydrolysis of angiotensinogen is inhibitable at 90% by pepstatin A (IC50 = 4.6 microM), consistent with a renin activity. This is the first biochemical evidence of renin-like enzyme in invertebrates.

  8. Isolation of a neuropeptide-degrading endopeptidase from the leech Theromyzon tessulatum.

    PubMed

    Laurent, V; Salzet, M

    1995-10-01

    Extracts of head parts prepared from the leech Theromyzon tessulatum hydrolyse the Gly3-Phe4 bond of synthetic [D-Ala2, Leu5]enkephalin and the Gly-His bond of benzoyl-Gly-His-Leu. The metabolism of benzoyl-Gly-His-Leu was completely inhibited by captopril, consistent with an angiotensin-converting enzyme activity. Such an enzyme has recently been isolated from T. tessulatum. However, the enkephalin hydrolysis by captopril (100 microM) was inhibited to a maximum of 70%. The residual activity hydrolyzing enkephalin was inhibited by phosphoramidon, consistent with the presence of endopeptidase-24.11, a mammalian enzyme implicated in the metabolism of neuropeptides. This enzyme was isolated using four steps of purification including gel-permeation and anion-exchange chromatographies followed by reverse-phase HPLC. This neuropeptide endopeptidase (of approximate molecular mass 45 kDa) hydrolyses, at pH 7 and 37 degrees C, both the Gly3-Phe4 bond of synthetic [D-Ala2, Leu5]enkephalin and the Phe8-His9 bond of angiotensin I. Cleavage of [D-Ala2, Leu5]enkephalin yields, respectively, the Tyr-D-Ala-Gly and Phe-Leu peptides with a specific activity of 29 nmol Tyr-D-Ala-Gly.min-1.mg protein-1 (Km 95 microM). The hydrolysis of angiotensin I yields angiotensin II and the dipeptide His-Leu with a specific activity of 1.2 nmol angiotensin min-1.mg protein-1 (Km 330 microM). The metabolism of these peptides was totally inhibited by phosphoramidon. This study therefore provides biochemical evidence for neuropeptide-degrading endopeptidases in leeches.

  9. 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.

  10. Initial formation and secondary condensation of nerve pathways in the medicinal leech.

    PubMed

    Jellies, J; Kopp, D M; Johansen, K M; Johansen, J

    1996-09-01

    Invertebrates have proved to be important experimental systems for examining questions related to growth cone navigation and nerve formation, in large part because of their simpler nervous systems. However, such apparent simplicity can be deceiving because the final stereotyped patterns may be the result of multiple developmental mechanisms and not necessarily the sole consequence of the pathway choices of individual growth cones. We have examined the normal sequence of events that are involved in the formation of the major peripheral nerves in leech embryos by employing (1) an antibody directed against acetylated tubulin to label neurons growing out from the central nervous system, (2) the Lan3-2 antibody to label a specific population of peripheral neurons growing into the central nervous system, and (3) intracellular dye filling of single cells. We found that the mature pattern of nerves was characterized by a pair of large nerve roots, each of which branched into two major tracts. The earliest axonal projections did not, however, establish this pattern definitively. Rather, each of the four nerves initially formed as discrete, roughly parallel tracts without bifurcation, with the final branching pattern of the nerve roots being generated by a secondary condensation. In addition, we found that some of the nerves were pioneered in different ways and by different groups of neurons. One of the nerves was established by central neurons growing peripherally, another by peripheral neurons growing centrally. These results suggest that the formation of common nerves and neuronal pathfinding in the leech involves multiple sets of growth cone guidance strategies and morphogenetic mechanisms that belie its apparent simplicity. PMID:8876458

  11. The use of medicinal leeches in fingertip replantation without venous anastomosis - case report of a 4-year-old patient.

    PubMed

    Streit, L; Dvořák, Z; Novák, O; Stiborová, S; Veselý, J

    2014-01-01

    Replantation of amputated fingertip is a technical challenge to the microsurgeons. The success rate depends directly on the availability and the size of preserved vessels and on the degree of their damage. In distal digital amputations, veins are usually not easily recovered or even absent, and thus high number of replantation procedures fails because of the venous congestion. The use of medicinal leeches is a treatment option for venous congestion of replanted fingers. A case report of a 4-year-old patient after fingertip replantation without venous anastomosis when temporary venous drainage was provided by an application of medicinal leeches is reported together with literature review. We observed an unusually short duration of venous congestion (48 hours) and there was no need of blood transfusion.

  12. A new species of the medicinal leech (Oligochaeta, Hirudinida, Hirudo) from Transcaucasia and an identification key for the genus Hirudo.

    PubMed

    Utevsky, Serge Y; Trontelj, Peter

    2005-12-01

    A recent molecular phylogenetic study has suggested that the genus Hirudo contains a neglected species previously known as the orientalis coloration type of the medicinal leech Hirudo medicinalis. In this paper, the new species is formally described as Hirudo orientalis sp. n. It can most readily be identified by the grass green coloration of the dorsum, segmentally arranged pairs of black quadrangular or rounded dots on its paramarginal dorsal stripes and similarly arranged, but less regular light-colored markings on the predominantly black venter. It has medium-sized epididymes and an evenly coiled vagina. H. orientalis is known from Transcaucasia, Iran, and Uzbekistan. It is widely used in medicine as the "medicinal leech." Very little is known about its exact distribution, specific habitat, and conservation status. The paper contains an identification key to all species of the genus Hirudo.

  13. Calreticulin contributes to C1q-dependent recruitment of microglia in the leech Hirudo medicinalis following a CNS injury

    PubMed Central

    Le Marrec-Croq, Françoise; Bocquet-Garcon, Annelise; Vizioli, Jacopo; Vancamp, Christelle; Drago, Francesco; Franck, Julien; Wisztorski, Maxence; Salzet, Michel; Sautiere, Pierre-Eric; Lefebvre, Christophe

    2014-01-01

    Background The medicinal leech is considered as a complementary and appropriate model to study immune functions in the central nervous system (CNS). In a context in which an injured leech’s CNS can naturally restore normal synaptic connections, the accumulation of microglia (immune cells of the CNS that are exclusively resident in leeches) has been shown to be essential at the lesion to engage the axonal sprouting. HmC1q (Hm for Hirudo medicinalis) possesses chemotactic properties that are important in the microglial cell recruitment by recognizing at least a C1q binding protein (HmC1qBP alias gC1qR). Material/Methods Recombinant forms of C1q were used in affinity purification and in vitro chemotaxis assays. Anti-calreticulin antibodies were used to neutralize C1q-mediated chemotaxis and locate the production of calreticulin in leech CNS. Results A newly characterized leech calreticulin (HmCalR) has been shown to interact with C1q and participate to the HmC1q-dependent microglia accumulation. HmCalR, which has been detected in only some microglial cells, is consequently a second binding protein for HmC1q, allowing the chemoattraction of resident microglia in the nerve repair process. Conclusions These data give new insight into calreticulin/C1q interaction in an immune function of neuroprotection, suggesting another molecular target to use in investigation of microglia reactivity in a model of CNS injury. PMID:24747831

  14. Comparative Transcriptomic Analyses of Three Species of Placobdella (Rhynchobdellida: Glossiphoniidae) Confirms a Single Origin of Blood Feeding in Leeches.

    PubMed

    Siddall, Mark E; Brugler, Mercer R; Kvist, Sebastian

    2016-02-01

    One of the recalcitrant questions regarding the evolutionary history of clitellate annelids involves the feeding preference of the common ancestor of extant rhynchobdellid (proboscis bearing) and arhynchobdellid (jaw bearing) leeches. Whereas early evidence, based on morphological data, pointed towards independent acquisitions of blood feeding in the 2 orders, molecular-based phylogenetic data suggest that the ancestor of modern leeches was a sanguivore. Here, we use a comparative transcriptomic approach in order to increase our understanding of the diversity of anticoagulation factors for 3 species of the genus Placobdella, for which comparative data have been lacking, and inspect these in light of archetypal anticoagulant data for both arhynchobdellid and other rhynchobdellid species. Notwithstanding the varying levels of host specificity displayed by the 3 different species of Placobdella, transcriptomic profiles with respect to anticoagulation factors were largely similar -this despite the fact that Placobdella kwetlumye only retains a single pair of salivary glands, as opposed to the 2 pairs more common in the genus. Results show that 9 different anticoagulant proteins and an additional 5 putative antihemostasis proteins are expressed in salivary secretions of the 3 species. In particular, an ortholog of the archetypal, single-copy, anticoagulant hirudin (not previously available as comparative data for rhynchobdellids) is present in at least 2 of 3 species examined, corroborating the notion of a single origin of blood feeding in the ancestral leech. PMID:26535976

  15. A new species of marine leech (Hirudinida: Piscicolidae) from giant kelpfish, Heterostichus rostratus Girard, in southern California.

    PubMed

    Burreson, Eugene M; Passarelli, Julianne Kalman; Kim, Bernard

    2012-08-01

    Collections of giant kelpfish at inner Cabrillo Beach, San Pedro, California revealed the presence of an undescribed species of Heptacyclus, described here as Heptacyclus cabrilloi n. sp. The leech is small, only up to 14 mm total length including suckers; it has 2 pair of slightly crescentiform eyes on the oral sucker, 1 pair of punctiform ocelli on the second annulus of the trachelosome, 13 pairs of punctiform ocelli dorsally and ventrally on the urosome, and 14 marginal punctiform ocelli on the caudal sucker. Pigmentation is yellowish-tan with an unpigmented mid-dorsal stripe on both trachelosome and urosome, and with unpigmented halos around eyespots and urosome ocelli. Male reproductive system with 5 pairs of large, spherical testisacs. Mycetomes present, accessory gland cells on atrial cornu absent. Prevalence was 24.1% in June, 2011 with a range of 1-2 leeches per fish and 25.8% in October, 2011 with a range of 1-6 leeches per fish. PMID:22401824

  16. 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

  17. First record of Limnatis paluda (Hirudinida, Arhynchobdellida, Praobdellidae) from Kazakhstan, with comments on genetic diversity of Limnatis leeches

    PubMed Central

    Dujsebayeva, Tatjana; Nishikawa, Kanto

    2015-01-01

    Abstract Background Sawyer (1986) included three species in the nasal leech genus Limnatis Moquin-Tandon 1827: Limnatis nilotica (Savigny 1822), Limnatis bacescui Manoleli 1972 and Limnatis paluda (Tennent 1859). The first and last species have mainly been identified in Middle Eastern countries (e.g. Kinzelbach and Rückert 1985). The second species has been identified only in Romania Dobruja (Manoleli 1972). Although Limnatis leeches are well known species of endoparasitic leeches, Limnatis nilotica was recorded only once in Kazakhstan (Lukin 1976). New information Specimens of the genus Limnatis from Almaty Province, Kazakhstan are identified as Limnatis paluda. This is the first record of Limnatis paluda from Kazakhstan. Mitochondrial COI and 12S data demonstrated that the present specimens are genetically close to an Israeli specimen identified as Limnatis nilotica. In addition, molecular data suggest that some Limnatis specimens whose DNA sequences have been reported were misidentified. According to the observed phylogenetic relationships, the taxonomic status of the known Limnatis species should be revisited. PMID:25941456

  18. 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.

  19. Physiological and behavioral evidence of a capsaicin-sensitive TRPV-like channel in the medicinal leech.

    PubMed

    Summers, Torrie; Holec, Sara; Burrell, Brian D

    2014-12-01

    Transient receptor potential vanilloid (TRPV) channels are found throughout the animal kingdom, where they play an important role in sensory transduction. In this study, we combined physiological studies with in vivo behavioral experiments to examine the presence of a putative TRPV-like receptor in the medicinal leech, building upon earlier studies in this lophotrochozoan invertebrate. The leech polymodal nociceptive neuron was activated by both peripheral and central application of the TRPV1-activator capsaicin in a concentration-dependent manner, with 100 μmol l(-1) being the lowest effective concentration. Responses to capsaicin were inhibited by the selective TRPV1 antagonist SB366791. The polymodal nociceptive neuron also responded to noxious thermal stimuli (>40°C), and this response was also blocked by SB366791. Capsaicin sensitivity was selective to the polymodal nociceptor with no direct response being elicited in the mechanical nociceptive neuron or in the non-nociceptive touch- or pressure-sensitive neurons. Capsaicin also elicited nocifensive behavioral responses (withdrawals and locomotion) in a concentration-dependent manner, and these behavioral responses were significantly attenuated with SB366791. These results suggest the presence of a capsaicin-sensitive TRPV-like channel in the medicinal leech central nervous system and are relevant to the evolution of nociceptive signaling.

  20. 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. PMID:27176910

  1. The influence of agricultural and urban contamination on leech infestation of freshwater turtles, Phrynops geoffroanus, taken from two areas of the Uberabinha River.

    PubMed

    De Campos Brites, Vera Lucia; Rantin, Francisco Tadeu

    2004-01-01

    Infestation by leeches on adult freshwater turtles Phrynops geoffroanus in two areas of the Uberabinha River, in Uberlândia, was investigated during the summer (January 2000). Fifty eight turtles were trapped: 26 (12 males, 14 females) in an agricultural area and 32 (16 males, 16 females) in an area with a more urban environment. The females present larger length and body mass (291.77+/-29.18 mm; 2233.30+/-511.40 g) than males (259.71+/-33.15 mm; 1488.68+/-529.35 g). Blood samples were drawn from the retrorbital sinus using heparinized micro-hematocrit capillary tubes, for microscopic and direct examination for intracellular parasites. Ectoparasitism by leeches, Placobdella bistriata, on young and adult animals was observed in the limb cavities of 28.1% of the urban area turtles. No leeches were found on the turtles in the agricultural area. Hemogregarine erythrocytic gametocytes were found in 15.4% of the agricultural area turtles, and in 37.5% of the urban area turtles. Concurrent parasitism by leeches and hemogregarines on the same individuals was seen on six turtles. Infections with microorganisms (bacteria and fungus) facilitated by the bites of leeches were not observed in another study on the same sample of infested turtles. However, 19% of the turtles collected in the agricultural area and 15% of the turtles from the urban area presented normocytic acute anemia. The occupation of the soil apparently interfered in the aquatic ecosystem favoring parasitism in the urban area. PMID:15327164

  2. 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.

  3. A new genus and species of fish leeches Dolichobdella rubra, gen. n., sp. n., (Clitellata, Hirudinida, Piscicolidae) from the northern Sea ofJapan

    NASA Astrophysics Data System (ADS)

    Utevsky, Serge Y.; Chernyshev, Alexei V.

    2013-02-01

    A new species of fish leeches, Dolichobdella rubra gen. n., sp. n., was found in samples collected by RV Akademik M.A. Lavrentyev in the northern Sea of Japan from 470-528 m during the joint Russian-German expedition SoJaBio (Sea of Japan Biodiversity Studies) in August 2010. The leech does not exceed 13 mm in length and has the following morphological characteristics: body elongated, smooth, lacking gills and pulsatile vesicles; eyes and ocelli absent; coloration reddish; female gonopore larger than male one; 6pairs of testisacs; accessory glands, conductive tissue and copulatory area present; ovisacs short; bursa long; coelomic system reduced.

  4. Biochemical evidence of specific trypsin-chymotrypsin inhibitors in the rhynchobdellid leech, Theromyzon tessulatum.

    PubMed

    Chopin, V; Stefano, G; Salzet, M

    2000-01-01

    The presence of two specific trypsin-chymotrypsin inhibitors from head parts of the rhynchobdellid leech Theromyzon tessulatum is reported. Two proteins, anti-trypsin chymotrypsin A (ATCA; 14636.6 +/- 131 Da) and anti-trypsin-chymotrypsin B (ATCB; 14368 +/- 95 Da) were purified by size exclusion and anion-exchange chromatography followed by reversed-phase HPLC. Based on amino-acid composition, N-terminal sequence determination (MELCELGQSCSRD-NPQPSNM), matrix assisted laser desorption-time of flight measurement (MALDI-TOF), trypsin mapping comparison, inhibition constant determination (Ki), and influence on amidolytic activity of different serine proteases, it is demonstrated that ATCA and ATCB are novel and highly potent serine-protease inhibitors of trypsin and chymotrypsin (ATCA: 350fM towards trypsin and chymotrypsin; ATCB: 400 and 75 fM towards trypsin and chymotrypsin, respectively). It is further surmised that ATCA and ATCB are linked, in that ATCB would lead to the formation of ATCA after loss of few amino acid residues.

  5. Nitridergic platelet pathway activation by hementerin, a metalloprotease from the leech Haementeria depressa.

    PubMed

    Chudzinski-Tavassi, Ana M; Bermej, Emilse; Rosenstein, Ruth E; Faria, Fernanda; Sarmiento, María I Keller; Alberto, Fabiana; Sampaio, Misako U; Lazzari, María A

    2003-09-01

    Hementerin (HT) is an 80 kDa fibrino(geno)lytic metalloprotease, purified from saliva of the leech Haementeria depressa. In the present report, the effect of HT on several functional parameters of human platelets was assessed. HT inhibited platelet aggregation and ATP release induced by different agonists such as ADP, adrenaline, collagen, thrombin, and arachidonic acid. HT did neither modify the expression of platelet glycoproteins (Ib, IIb-IIIa, Ia-IIa, IV) nor intraplatelet fibrinogen levels, whereas it markedly decreased CD62P and CD63 levels after the stimulation with thrombin. HT significantly increased thrombin-induced platelet Ca2+ intracellular levels, cGMP content and nitric oxide synthase (NOS) activity. The effect of HT on platelet aggregation was reversed by two NOS inhibitors, N(omega)-Nitro-L-arginine methyl ester and 2 N(G)-Nitro-L-arginine. In summary, these results indicate that HT is an effective inhibitor of human platelet aggregation, presumably through activation of the platelet's nitridergic pathway.

  6. Seasonal variation of long-term potentiation at a central synapse in the medicinal leech.

    PubMed

    Grey, Kathryn B; Burrell, Brian D

    2011-08-01

    Long-term potentiation (LTP) is a persistent increase in synaptic transmission that is thought to contribute to a variety of adaptive processes including learning and memory. Although learning is known to undergo circannual variations, it is not known whether LTP undergoes similar changes despite the importance of LTP in learning and memory. Here we report that synapses in the CNS of the medicinal leech demonstrate seasonal variation in the capacity to undergo LTP following paired presynaptic and postsynaptic stimulation. LTP was observed during the April-October period, but no LTP was observed during the November-March period. Application of forskolin, a technique often used to produce chemical LTP, failed to elicit potentiation during the November-March period. Implementing stimulation patterns that normally result in long term depression (LTD) also failed to elicit any change in synaptic strength during the November-March period. These experiments indicate that LTP and LTD can be influenced by circannual rhythms and also suggest a seasonal influence on learning and memory.

  7. Destabilase complexes--natural liposome produced by medicinal leeches Hirudo medicinalis.

    PubMed

    Nikonov, G I; Titova, E A

    1999-01-01

    Electrophoretic analysis of destabilase preparation demonstrates the presence of protein combinations with MW 12.3, 25 and 50 kD. Fraction (MW 12.3 D) is a monomer of destabilase aggregation having properties of micellar proteins and represents a stable lipid-protein complex, where the role of lipid component is played by the stable analogue of prostacyclin (MW 391 D). The synthesis of a low molecular fraction of destabilase is fulfilled with bacteria--symbiont of leeches Aeromonas hydrophila. When the destabilase (MW 12.3 kD) contacts with blood a process of complexe formation is triggered with hirudin and blood plasma kallikrein inhibitor, forming a stable 'destabilase complex' (DC; MW 25 kD), possessing also a high aggregation capacity. Polymer forms of the destabilase complex form a liposome changing its spatial orientation depending on the nature of the solvent. Such structural organization provides a high stability of DC components and a rapid penetration through cellular membranes (transmembrane transfer) and it also provides prophylactic antithrombotic action in the case of peroral application to animals, due to the blockade of vascular platelets (inhibition of platelet aggregation by prostacyclin analogue) and plasmic (inhibition of thrombin activity and blood plasma kallikrein) links of the hemostasis process. Destabilase fraction with MW 50 kD is a dimer of the destabilase complex. As a result of DC destruction (liposome), hirudin, prostacycline analogue and blood plasma kallikrein inhibitor are released.

  8. 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.

  9. 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

  10. Generation of recombinant destabilase-lysozyme from medicinal leeches in three different expression systems.

    PubMed

    Manuvera, Valentin A; Kurdyumov, Alexey S; Filonova, Kseniya A; Lazarev, Vassili N

    2015-12-01

    Destabilase-lysozyme (mlDL) is an enzyme secreted by the salivary gland cells of medicinal leeches. Destabilase-lysozyme possesses lysozyme and isopeptidase activities. We generated recombinant destabilase-lysozyme isoform 2 in three expression systems, i.e., in the bacteria Escherichia coli, in the yeast Pichia pastoris, and in the human cell line Expi293F. In E. coli, we generated both polypeptide in inclusion bodies that was later undergone to the refolding and soluble protein that had been fused with the chaperone SlyD. The chaperone was later cleaved by a specific TEV-protease. In cultures of the yeast P. pastoris and the human cell line Expi293F, the soluble form of destabilase-lysozyme was accumulated in the culture media. For the generated enzymes, we determined the lysozyme, isopeptidase and fibrinolytic activities and tested their general antimicrobial effects. The comparisons of the enzymes generated in the different expression systems revealed that all of the destabilase-lysozymes obtained in the soluble forms possessed equal levels of lysozyme, isopeptidase and fibrinolytic activities that exceeded several to ten times the levels of the same activities of the destabilase-lysozyme renaturated from the inclusion bodies. A similar pattern of the differences in the levels of the general antimicrobial effects was observed for the destabilase-lysozymes generated in the soluble form and as inclusion bodies.

  11. Seasonal variation of long-term potentiation at a central synapse in the medicinal leech

    PubMed Central

    Grey, Kathryn B.; Burrell, Brian D.

    2011-01-01

    SUMMARY Long-term potentiation (LTP) is a persistent increase in synaptic transmission that is thought to contribute to a variety of adaptive processes including learning and memory. Although learning is known to undergo circannual variations, it is not known whether LTP undergoes similar changes despite the importance of LTP in learning and memory. Here we report that synapses in the CNS of the medicinal leech demonstrate seasonal variation in the capacity to undergo LTP following paired presynaptic and postsynaptic stimulation. LTP was observed during the April–October period, but no LTP was observed during the November–March period. Application of forskolin, a technique often used to produce chemical LTP, failed to elicit potentiation during the November–March period. Implementing stimulation patterns that normally result in long term depression (LTD) also failed to elicit any change in synaptic strength during the November–March period. These experiments indicate that LTP and LTD can be influenced by circannual rhythms and also suggest a seasonal influence on learning and memory. PMID:21753047

  12. 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).

  13. Multivariable harmonic balance analysis of the neuronal oscillator for leech swimming.

    PubMed

    Chen, Zhiyong; Zheng, Min; Friesen, W Otto; Iwasaki, Tetsuya

    2008-12-01

    Biological systems, and particularly neuronal circuits, embody a very high level of complexity. Mathematical modeling is therefore essential for understanding how large sets of neurons with complex multiple interconnections work as a functional system. With the increase in computing power, it is now possible to numerically integrate a model with many variables to simulate behavior. However, such analysis can be time-consuming and may not reveal the mechanisms underlying the observed phenomena. An alternative, complementary approach is mathematical analysis, which can demonstrate direct and explicit relationships between a property of interest and system parameters. This paper introduces a mathematical tool for analyzing neuronal oscillator circuits based on multivariable harmonic balance (MHB). The tool is applied to a model of the central pattern generator (CPG) for leech swimming, which comprises a chain of weakly coupled segmental oscillators. The results demonstrate the effectiveness of the MHB method and provide analytical explanations for some CPG properties. In particular, the intersegmental phase lag is estimated to be the sum of a nominal value and a perturbation, where the former depends on the structure and span of the neuronal connections and the latter is roughly proportional to the period gradient, communication delay, and the reciprocal of the intersegmental coupling strength. PMID:18663565

  14. 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

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

    PubMed

    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

  16. Metabolism of enkephalins in head membranes of the leech Theromyzon tessulatum by peptidases: isolation of an enkephalin-degrading aminopeptidase.

    PubMed

    Laurent, V; Salzet, M

    1996-09-01

    Metabolism of leucine and methionine enkephalins by enzyme preparations from head parts of the leech Theromyzon tessulatum was investigated. Leech homogenate degraded enkephalins by cleavage of the Tyr1-Gly2 and Gly3-Phe4 bonds. The Tyr1-Gly2-Gly3 was detected as a major metabolite when amastatin (aminopeptidase inhibitor) was present to prevent Tyr1-Gly2 breakdown. Around 50% of enkephalin-degrading activity was isolated in a 20000 x g membrane fraction and was shown to be almost entirely due to an aminopeptidase activity. This enzyme, a homodimer of approx. 70 kDa, has been purified to homogeneity by a combined approach including gel permeation and anion exchange chromatographies followed by reversed-phase HPLC. This enkephalin-degrading aminopeptidase is a typical integral membrane 'zincin' metalloprotein with an apparent k(m) of 30 microM, a specific activity of 12 nmol GGFM min-1 mg protein-1 and a catalytic efficiency (kcat/k(m)) of 46 x 10(6) mol-1 min-1. This enzyme is specifically inhibited by amastatin (IC50 = 0.5 microM), but not by bestatin and actinonin. In leech membranes, the other degrading activities performed at the same time were due to a neuropeptide-endopeptidase (NEP)-like enzyme attack, inhibited by phosphoramidon (IC50 = 0.1 microM) and in the case of the Met-enkephalin by a combined action of an angiotensin-converting-like enzyme, inhibited by captopril (IC50 = 0.2 microM) and the NEP-like enzyme. These two enzymes were previously isolated from head membranes of T. tessulatum and possess towards Met-enkephalin a catalytic efficiency (kcat/k(m)) of, respectively, 12 x 10(6) mol-1 min-1 and 78 x 10(6) mol-1 min-1. These findings constitute the first report in leeches on the nature and the sites of attack of the membrane peptidases involved in the metabolism of enkephalins and also the first biochemical evidence for a novel member of the aminopeptidase family.

  17. 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.

  18. 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

    2015-01-01

    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

  19. Microbial challenge promotes the regenerative process of the injured central nervous system of the medicinal leech by inducing the synthesis of antimicrobial peptides in neurons and microglia.

    PubMed

    Schikorski, David; Cuvillier-Hot, Virginie; Leippe, Matthias; Boidin-Wichlacz, Céline; Slomianny, Christian; Macagno, Eduardo; Salzet, Michel; Tasiemski, Aurélie

    2008-07-15

    Following trauma, the CNS of the medicinal leech, unlike the mammalian CNS, has a strong capacity to regenerate neurites and synaptic connections that restore normal function. In this study, we show that this regenerative process is enhanced by a controlled bacterial infection, suggesting that induction of regeneration of normal CNS function may depend critically upon the coinitiation of an immune response. We explore the interaction between the activation of a neuroimmune response and the process of regeneration by assaying the potential roles of two newly characterized antimicrobial peptides. Our data provide evidence that microbial components differentially induce the transcription, by microglial cells, of both antimicrobial peptide genes, the products of which accumulate rapidly at sites in the CNS undergoing regeneration following axotomy. Using a preparation of leech CNS depleted of microglial cells, we also demonstrate the production of antimicrobial peptides by neurons. Interestingly, in addition to exerting antibacterial properties, both peptides act as promoters of the regenerative process of axotomized leech CNS. These data are the first to report the neuronal synthesis of antimicrobial peptides and their participation in the immune response and the regeneration of the CNS. Thus, the leech CNS appears as an excellent model for studying the implication of immune molecules in neural repair. PMID:18606660

  20. 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

  1. 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

  2. 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

  3. 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

  4. Structural characterization of a diuretic peptide from the central nervous system of the leech Erpobdella octoculata. Angiotensin II Amide.

    PubMed

    Salzet, M; Bulet, P; Wattez, C; Verger-Bocquet, M; Malecha, J

    1995-01-27

    Purification of a material immunoreactive to an antiserum against angiotensin II and present in the central nervous system of the pharyngobdellid leech Erpobdella octoculata was performed by reversed-phase high pressure liquid chromatography combined with both enzyme-linked immunosorbent assay and dot immunobinding assays for angiotensin II. Establishment of the amino acid sequence by Edman degradation, electrospray, and fast atom bombardement mass spectrometry measurements and enzymatic treatment by carboxypeptidase A indicated that this "central" angiotensin II-like material, the first one fully characterized in the animal kingdom, is an angiotensin II amide. This finding constitutes also the first biochemical characterization of a peptide of the angiotensin family in an invertebrate. Synthetic angiotensin II amide exerts, when injected in leeches, a diuretic effect and is, 1 and 2 h postinjection, 100-fold more potent than vertebrate angiotensin II. An identification of the proteins immunoreactive to an antiserum against angiotensin II performed at the level of both central nervous system extracts and in vitro central nervous system-translated RNA products indicated that in the two cases, two proteins were detected. Their molecular masses, which were, respectively, approximately 14 and approximately 18 kDa for the central nervous system extracts and approximately 15 and approximately 19 kDa for in vitro central nervous system-translated RNA products, differ from that of angiotensinogen (approximately 60 kDa), the precursor of vertebrate angiotensin II.

  5. Biochemical evidence of angiotensin II-like peptides and proteins in the brain of the rhynchobdellid leech Theromyzon tessulatum.

    PubMed

    Salzet, M; Wattez, C; Baert, J L; Malecha, J

    1993-12-24

    The peptides contained in neurons localized in the brain of the leech Theromyzon tessulatum (Hirudinae, Rhynchobdellida) and showing an immunopositive reaction with an antibody directed against angiotensin II (AII), were purified by reversed-phase HPLC. Three AII-like peptides (P1, P2 and P3) which exhibited the same retention times and chromatographic behaviors as synthetic AVII (fragment 6-8 of AII), AIV (fragment 3-8 of AII) and AII, respectively, were resolved in brain extracts. An identification of the proteins immunoreactive to an anti-AII was performed at the level of both brain extracts and in vitro brain-translated RNA products. The protein detected at the level of the brain extracts (of a molecular mass of approximately 18 kDa) is multipeptidic as it is also recognized by two other antisera, a polyclonal one directed against gamma-MSH and a monoclonal one (Tt159) raised against a leech brain epitope. It could be the pro-AII-like precursor. The protein detected at the level of in vitro brain-translated RNA products (of a molecular mass of approximately 19 kDa) could be the prepro-AII-like precursor.

  6. Heartbeat control in the medicinal leech: a model system for understanding the origin, coordination, and modulation of rhythmic motor patterns.

    PubMed

    Calabrese, R L; Nadim, F; Olsen, O H

    1995-07-01

    We have analyzed in detail the neuronal network that generates heartbeat in the leech. Reciprocally inhibitory pairs of heart interneurons form oscillators that pace the heartbeat rhythm. Other heart interneurons coordinate these oscillators. These coordinating interneurons, along with the oscillators interneurons, form an eight-cell timing oscillator network for heartbeat. Still other interneurons, along with the oscillator interneurons, inhibit heart motor neurons, sculpting their activity into rhythmic bursts. Critical switch interneurons interface between the oscillator interneurons and the other premotor interneurons to produce two alternating coordination states of the motor neurons. The periods of the oscillator interneurons are modulated by endogenous RFamide neuropeptides. We have explored the ionic currents and graded and spike-mediated synaptic transmission that promote oscillation in the oscillator interneurons and have incorporated these data into a conductance-based computer model. This model has been of considerable predictive value and has led to new insights into how reciprocally inhibitory neurons produce oscillation. We are now in a strong position to expand this model upward, to encompass the entire heartbeat network, horizontally, to elucidate the mechanisms of FMRFamide modulation, and downward, to incorporate cellular morphology. By studying the mechanisms of motor pattern formation in the leech, using modeling studies in conjunction with parallel physiological experiments, we can contribute to a deeper understanding of how rhythmic motor acts are generated, coordinated, modulated, and reconfigured at the level of networks, cells, ionic currents, and synapses.

  7. 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

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

    PubMed

    Fedorova, Lyudmila I; Kaygorodova, Irina A

    2016-01-01

    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. 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

  11. Activation of two forms of locomotion by a previously identified trigger interneuron for swimming in the medicinal leech.

    PubMed

    Brodfuehrer, Peter D; McCormick, Kathryn; Tapyrik, Lauren; Albano, Alfonso M; Graybeal, Carolyn

    2008-03-01

    Higher-order projection interneurons that function in more than one behavior have been identified in a number of preparations. In this study, we document that stimulation of cell Tr1, a previously identified trigger interneuron for swimming in the medicinal leech, can also elicit the motor program for crawling in isolated nerve cords. We also show that motor choice is independent of the firing frequency of Tr1 and amount of spiking activity recorded extracellularly at three locations along the ventral nerve cord prior to Tr1 stimulation. On the other hand, during Tr1 stimulation there is a significant difference in the amount of activity elicited in the ventral nerve cord that correlates with the motor program activated. On average, Tr1 stimulation trials that lead to crawling elicit greater amounts of activity than in trials that lead to swimming.

  12. 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. PMID:1821771

  13. 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. PMID:23053229

  14. 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

  15. Isolation and structural characterization of a novel peptide related to gamma-melanocyte stimulating hormone from the brain of the leech Theromyzon tessulatum.

    PubMed

    Salzet, M; Wattez, C; Bulet, P; Malecha, J

    1994-07-01

    This paper reports the purification of a novel pro-opiomelanocortin derivative peptide (a gamma-melanocyte stimulating hormone-like (gamma-MSH-like) molecule) from the brain of the leech Theromyzon tessulatum. After reverse-phase HPLC purification, the sequence of the gamma-MSH-like peptide (YVMGHFRWDKFamide) was established by a combination of automated Edman degradation, electrospray mass spectrometry measurement, enzymatic treatment and co-elution experiments in reverse-phase HPLC with synthetic peptides.

  16. 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.

  17. Austrobdella cairae n. sp., an Oioxenous Marine Leech (Clitellata: Piscicolidae) from the Banded Guitarfish, Zapteryx exasperata, in the Northeastern Pacific Ocean.

    PubMed

    Curran, Stephen S; Phillips, Anna J; Overstreet, Robin M; Benz, George W; Henningsen, Alan D

    2016-04-01

    A new marine leech is herein described from specimens infecting the external surfaces, including the mouth and cloaca, of the banded guitarfish, Zapteryx exasperate, captured in the Gulf of California and eastern Pacific Ocean off the coast of San Diego, California. The leech is assigned to Austrobdella by possessing continuous contractile coelomic channels that lie outside the somatic musculature along the lateral edges of the urosome (marginal lacunae), clitellar gland cells densely packed in the urosome, 5 pairs of testisacs, and 6-annulate mid-body somites. The new leech is distinguished from its 6 congeners on the basis of body size (maximum 10 mm long) and shape (sub-cylindrical trachelosome distinctly demarcated from wider urosome that is ventrally flattened, convex dorsally, and narrowing toward caudal sucker that is narrow, 20-25% of maximum body width), number of eyespots (2 pairs), shape and arrangement of the ovisacs (pyriform and limited to somites XII/XIII), and characteristics of the midgut (1 pair of mycetomes, 6 pairs of simple thin-walled crop ceca, ventral postceca wanting, and 2 pairs of dendritic diverticula emerging from anterior portion of thick-walled intestine). The new species occurs in the northeastern Pacific Ocean on a benthic elasmobranch. Examination of host specificity for each Austrobdella species using the quantitative Index of Phylogenetic Host Specificity revealed that the new species is 1 of 4 oioxenous specialists in the genus, and the remaining 3 congeners are relative generalists herein classified as euryxenous. This is the first time host specificity for members of the Piscicolidae has been quantitatively assessed. The analysis suggests that associations between marine leeches belonging in Austrobdella and their vertebrate hosts are driven by ecological influences rather than host taxonomic placement. PMID:26800278

  18. New insights into the North American Cordillera forearc: Cretaceous to Eocene tectonic evolution of the Leech River Schist, Southern Vancouver Island, Canada

    NASA Astrophysics Data System (ADS)

    Jakob, Johannes; Johnston, Stephen

    2015-04-01

    The Leech River Complex on southern Vancouver Island is a part of the Pacific Rim Terrane of the North American Cordillera and comprises a series of fault-bounded slices of mainly meta-sedimentary and meta-igneous rocks of Triassic to Cretaceous age. The tectono-metamorphic history of this unit provides important constraints on the history of terrane accretion and the paleogeographic and tectonic evolution of the western North American forearc region. Our focus is on the structures and tectonic fabrics that developed within the western most part of the Leech River Schist from ~88 Ma through ~37 Ma. Similar syn- and post-instrusive structures that developed during emplacement of the ~88 Ma Jordan River meta-granodiorite and the ~51 Ma Walker Creek Intrusions respectively, indicate a consistent stress field during >35 m.y. of northward translation of the outboard Cordilleran terranes. A regional high temperature, Staurolite-Andalusite-grade metamorphic event is recorded in the meta-sedimentary rocks. Subcretion of the Crescent terrane beneath the Leech River Schist at ~51 Ma caused folding of the metamorphic rocks, the development of a system of dextral and sinistral brittle shears, and normal faulting. Related extension to the northwest resulted in the opening of Barkley Sound and the more westerly marine Tofino basin. These multi-faceted deformational structures are most likely a direct consequence of the subcretion of the Crescent terrane and the linked development of the Southern Vancouver Island Orocline. The deposition of sandstones and conglomerates of the Sooke Formation began at ca. 37 Ma. This siliciclastic sequence unconformably overlies the Leech River Schist, records rapid subsidence of the forearc following a preceding uplift and exhumation event, and may be a record of a younger subcretion event.

  19. 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

  20. 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. PMID:26180186

  1. Austrobdella cairae n. sp., an Oioxenous Marine Leech (Clitellata: Piscicolidae) from the Banded Guitarfish, Zapteryx exasperata, in the Northeastern Pacific Ocean.

    PubMed

    Curran, Stephen S; Phillips, Anna J; Overstreet, Robin M; Benz, George W; Henningsen, Alan D

    2016-04-01

    A new marine leech is herein described from specimens infecting the external surfaces, including the mouth and cloaca, of the banded guitarfish, Zapteryx exasperate, captured in the Gulf of California and eastern Pacific Ocean off the coast of San Diego, California. The leech is assigned to Austrobdella by possessing continuous contractile coelomic channels that lie outside the somatic musculature along the lateral edges of the urosome (marginal lacunae), clitellar gland cells densely packed in the urosome, 5 pairs of testisacs, and 6-annulate mid-body somites. The new leech is distinguished from its 6 congeners on the basis of body size (maximum 10 mm long) and shape (sub-cylindrical trachelosome distinctly demarcated from wider urosome that is ventrally flattened, convex dorsally, and narrowing toward caudal sucker that is narrow, 20-25% of maximum body width), number of eyespots (2 pairs), shape and arrangement of the ovisacs (pyriform and limited to somites XII/XIII), and characteristics of the midgut (1 pair of mycetomes, 6 pairs of simple thin-walled crop ceca, ventral postceca wanting, and 2 pairs of dendritic diverticula emerging from anterior portion of thick-walled intestine). The new species occurs in the northeastern Pacific Ocean on a benthic elasmobranch. Examination of host specificity for each Austrobdella species using the quantitative Index of Phylogenetic Host Specificity revealed that the new species is 1 of 4 oioxenous specialists in the genus, and the remaining 3 congeners are relative generalists herein classified as euryxenous. This is the first time host specificity for members of the Piscicolidae has been quantitatively assessed. The analysis suggests that associations between marine leeches belonging in Austrobdella and their vertebrate hosts are driven by ecological influences rather than host taxonomic placement.

  2. Electrogenic sodium-dependent bicarbonate secretion by glial cells of the leech central nervous system

    PubMed Central

    1991-01-01

    The ability to move acid/base equivalents across the membrane of identified glial cells was investigated in isolated segmental ganglia of the leech Hirudo medicinalis. The intracellular pH (pHi) of the glial cells was measured with double-barreled, neutral-ligand, ion- sensitive microelectrodes during step changes of the external pH (pHo 7.4-7.0). The rate of intracellular acidification after the decrease in extracellular pH (pHo) was taken as a measure of the rate of acid/base transport across the glial membrane. Taking into account the total intracellular buffering power, the maximum rate of acid/base flux was 0.4 mM/min in CO2/HCO3-free saline, and 3.92 mM/min in the presence of 5% CO2/10 mM HCO-3, suggesting that the acid/base flux was dependent upon HCO3-. The rate of acid influx/base efflux increased both with the external HCO3- concentration and with increasing pHi (and hence HCO3- i). This suggested that the decrease in pHi was due to HCO3- efflux. The rapid decrease of pHi was accompanied by a HCO3--dependent depolarization of the glial membrane from -74 +/- 5 mV (n = 20) to -54 +/- 7 mV (n = 13). Both this depolarization and the rate of intracellular acidification were greatly reduced by the anion exchange inhibitor 4,4-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS; 0.3- 0.5 mM), but were not affected by the removal of external Cl-. Reduction of the external Na+ concentration to one-tenth normal affected the rate of intracellular acidification only in the presence of CO2/HCO3-: the rate increased within the first 3-5 min after lowering external Na+; after longer exposures in low external Na+ the rate decreased, presumably due to depletion of intracellular Na+. Amiloride (1 mM), which inhibits the Na+-H+ exchange in these cells, had no effect on the rate of intracellular acidification. The intracellular Na activity (aNai) of the glial cells was measured to be 5.2 +/- 1.0 mM (n = 8) in CO2/HCO3-free saline; aNai increased to 7.3 +/- 2.2 mM (n = 8

  3. Infections of Hypostomus spp. by Trypanosoma spp. and leeches: a study of hematology and record of these hirudineans as potential vectors of these hemoflagellates.

    PubMed

    Corrêa, Lincoln Lima; Oliveira, Marcos Sidney Brito; Tavares-Dias, Marcos; Ceccarelli, Paulo Sérgio

    2016-01-01

    Among Kinetoplastida, the Trypanosoma is the genus with the highest occurrence infecting populations of marine fish and freshwater in the world, with high levels of prevalence, causing influences fish health and consequent economic losses, mainly for fish populations in situation stress. This study investigated infections of Hypostomus spp. by Trypanosoma spp. and leeches, as well as blood parameters of this host in the network of tributaries of the Tapajós River in the state of Pará, in the eastern Amazon region in Brazil. Of the 47 hosts examined, 89.4% were parasitized by Trypanosoma spp. and 55.4% also had leeches attached around the mouth. The intensity of Trypanosoma spp. increased with the size of the host, but the body conditions were not influenced by the parasitism. The number of red blood cells, and hemoglobin, mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC), mean corpuscular hemoglobin (MCH), total number of leukocytes and thrombocytes showed variations and negative correlation with the intensity of Trypanosoma spp. in the blood of the hosts. The results suggest that the leeches were vectors of Trypanosoma spp. in Hypostomus spp. PMID:27580397

  4. Isolation, structural characterization and biological function of a lysine-conopressin in the central nervous system of the pharyngobdellid leech Erpobdella octoculata.

    PubMed

    Salzet, M; Bulet, P; Van Dorsselaer, A; Malecha, J

    1993-11-01

    Several neuropeptides are suspected to act on the control of hydric balance in leeches. One of these peptides, a peptide immunoreactive to an antibody against oxytocin, was previously characterized from the central nervous system of the leech Erpobdella octoculata [Salzet, M., Wattez, C., Verger-Bocquet, M., Beauvillain, J.-C. & Malecha, J. (1993) Brain Res. 601, 173-184]. This paper reports the isolation from the central nervous system of E. octoculata of another peptide of the oxytocin/vasopressin family; a lysine-vasopressin-like molecule. Its purification was performed by reverse-phase high-performance liquid chromatography combined with both dot immunobinding assay and enzyme-linked immunosorbent assay for lysine-vasopressin. The amino acid sequence was established by Edman degradation and confirmed by electrospray-mass-spectrometry measurement. The nonapeptide obtained corresponded to the lysine-conopressin previously isolated from the venom of the mollusc Conus geographus [Cruz, L. L., de Santos, V., Zafaralla, G. C., Ramilo, C. A., Zeikus, R., Gray, W. R. & Olivera, B. M. (1987) J. Biol. Chem. 262, 15821-15824]. In leeches, synthetic lysine-conopressin exerts a diuretic effect which can be compared to that of the arginine-vasopressin-like peptide isolated in the Insect Locusta migratoria [Proux, J., Miller, C. A., Li, J. P., Carney, R. L., Girardie, A., Delaage, M. & Schooley, D. A. (1987) Biochem. Biophys. Res. Commun. 149, 180-186].

  5. 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

  6. Leeches of the genus Helobdella (Clitellata: Hirudinida) from São Paulo, Brazil with descriptions of two new species using micro-computed tomography and a new record of Barbronia weberi (Blanchard 1897).

    PubMed

    Iwama, Rafael Eiji; Arruda, Eliane Pintor

    2016-01-01

    Leeches are an important group of macroinvertebrates found in the benthic zone of rivers, streams, lakes and ponds. Despite their ecological importance and potential as bioindicators, little is known about the diversity of leeches in Brazil, where only a few sporadic studies have been performed. Six locations in the region of Sorocaba, in the state of São Paulo, were sampled in order to study the diversity of predatory leeches. Besides traditional dissections, micro-computed tomography was used to access the internal morphology of the new species Helobdella chaviensis n. sp. and Helobdella schlenzae n. sp. Four additional native species were found and redescribed using traditional techniques. The invasive species Barbronia weberi (Blanchard 1897) was reported in the Tietê River for the first time. PMID:27470865

  7. Receptive fields, geometry and conduction block of sensory neurones in the central nervous system of the leech.

    PubMed Central

    Yau, K W

    1976-01-01

    1. In segmental ganglia of the leech, the cutaneous mechanosensory neurones responding to to touch innervated the skin of their own segment and of part of the anterior and posterior adjacent segments. Each touch receptive field could be divided into three non-overlapping areas: a central part innervated by the branches of the cell which ran in the nerve roots of the ganglion containing the cell body, and anterior and posterior parts innervated by its branches which ran in the nerve roots of the anterior and posterior adjacent ganglia. 2. Impulses originating from the anterior and posterior parts of the receptive fields were susceptible to conduction block within the central nervous system when the touch cells fired repetitively at frequencies that could readily be elicited with weak mechanical stimulation. In contrast, impulses originating from the central part of the receptive fields were less susceptible to block. 3. The morphology of touch cells revealed by intracellular injection of horseradish peroxidase suggested that conduction block occurred at specific bifurcation points where small cell processes joined the main process. Different physiological experiments supported this conclusion. 4. In some touch cells, bifurcation points with particularly low safety margins of conduction operated as low-pass filters, limiting the frequency of impulses capable of invading certain branches. 5. The results suggest that mechanical stimuli which would likely be encountered by the animal can lead to conduction block within its central nervous system and as a result modify its integrative activities. PMID:1018277

  8. 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.

  9. A functional asymmetry in the Leech Heartbeat Timing Network is revealed by driving the network across various cycle periods.

    PubMed

    Masino, Mark A; Calabrese, Ronald L

    2002-06-01

    We tested predictions of a computational model (Hill et al., 2002) of the leech heartbeat timing network. The timing network consists of two segmental oscillators located in the third (G3) and fourth (G4) segmental ganglia. Each oscillator consists of two reciprocally inhibitory oscillator interneurons along with the coordinating interneuron fibers that link them. In the model, the network was driven to cycle periods around the normal period of the network by repeatedly stimulating one of the paired oscillator interneurons in G3 or G4. Here we replicate these experiments in the biological system. The model predicts that the G3 and G4 oscillators can entrain the timing network to periods faster but not slower than the inherent period of the nondriven ("follower") oscillator and that they can do so symmetrically. The biological system can be driven to periods both faster (such that the driven oscillator leads in phase) and slower (such that the driven oscillator lags in phase) than the inherent period of the timing network. Although both oscillators can entrain the network, the G4 oscillator does so over a narrower range of periods. Two differences between the assumptions of the model and the properties of the biological network, spike frequency adaptation in coordinating interneurons and asymmetry in the connections from the oscillator interneurons to the coordinating interneurons, may account for these discrepancies. Individual coordinating interneurons were also able to entrain the oscillators but with little effect of the phase relationship between the oscillators, suggesting that phase relations are determined by properties inherent to the oscillator interneurons.

  10. Kinematics and modeling of leech crawling: evidence for an oscillatory behavior produced by propagating waves of excitation.

    PubMed

    Cacciatore, T W; Rozenshteyn, R; Kristan, W B

    2000-02-15

    Many well characterized central pattern generators (CPGs) underlie behaviors (e.g., swimming, flight, heartbeat) that require regular rhythmicity and strict phase relationships. Here, we examine the organization of a CPG for leech crawling, a behavior whose success depends more on its flexibility than on its precise coordination. We examined the organization of this CPG by first characterizing the kinematics of crawling steps in normal and surgically manipulated animals, then by exploring its features in a simple neuronal model. The behavioral observations revealed the following. (1) Intersegmental coordination varied considerably with step duration, whereas the rates of elongation and contraction within individual segments were relatively constant. (2) Steps were generated in the absence of both head and tail brains, implying that midbody ganglia contain a CPG for step production. (3) Removal of sensory feedback did not affect step coordination or timing. (4) Imposed stretch greatly lengthened transitions between elongation and contraction, indicating that sensory pathways feed back onto the CPG. A simple model reproduced essential features of the observed kinematics. This model consisted of an oscillator that initiates propagating segmental waves of activity in excitatory neuronal chains, along with a parallel descending projection; together, these pathways could produce the observed intersegmental lags, coordination between phases, and step duration. We suggest that the proposed model is well suited to be modified on a step-by-step basis and that crawling may differ substantially from other described CPGs, such as that for swimming in segmented animals, where individual segments produce oscillations that are strongly phase-locked to one another. PMID:10662854

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

    PubMed

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

    2014-11-15

    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/cm(2) 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/cm(2) 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/cm(2) 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.

  12. 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

  13. A comparison of the leech Theromyzon tessulatum angiotensin I-like molecule with forms of vertebrate angiotensinogens: a hormonal system conserved in the course of evolution.

    PubMed

    Laurent, V; Bulet, P; Salzet, M

    1995-05-12

    After five steps of purification including gel permeation, anti-angiotensin I affinity column chromatography followed by reverse-phase HPLC, a peptide immunoreactive to two different antisera (anti-angiotensin II and anti-angiotensin I) was purified to homogeneity from extracts of the leech Theromyzon tessulatum. The first 14 amino acid residues of the purified peptide (DRVYIHPFHLLXWG) established by automated Edman degradation, reveal the existence in leeches of an angiotensin I-like molecule close to human angiotensin I. The sequence of the purified peptide presents 78.5% of homology with the N-terminal part of human angiotensinogen. Moreover, in its sequence, this peptide presents the cleavage sites of vertebrate angiotensin metabolic enzymes, i.e. the renin and the angiotensin-converting enzyme. This finding constitutes the first biochemical characterization of an angiotensin I in Invertebrates. It also reflects the high conservation of angiotensins in the course of evolution, suggesting a fundamental role of this family in fluid homeostasis.

  14. A comparison of the N-terminal sequence of the leech Theromyzon tessulatum angiotensin converting-like enzyme with forms of vertebrate angiotensin converting enzymes.

    PubMed

    Laurent, V; Salzet, M

    1995-09-22

    This paper reports the purification of an angiotensing-converting like enzyme (ACE) of ca. 120 kDa from extracts of head membranes of the leech Theromyzon tessulatum. After solubilization with Triton X-114, the ACE-like enzyme contained in the detergent-poor fraction was separated using five steps of purification including gel permeation and anion exchange chromatographies followed by reverse-phase HPLC. The first 23 amino acid residues of the N-terminal part (GLDPELSPGCFSADEAGAQLFAE) of the purified S-pyridylethylated leech ACE established by automated Edman degradation revealed ca. 87% sequence identity with the N-terminal sequence of the guinea pig ACE. This enzyme cleaves the hyppuryl-His-Leu substrate with a specific activity of 5600 nmol hyppurate min-1 mg protein-1. Hydrolysis of this substrate by ACE-like enzyme is inhibited at 80% by 10 microM captopril or 10 microM lisinopril (IC50 of 200 nM and 50 nM, respectively). This enzyme is close in sequence and in activity to single domain vertebrate ACE. This is the first N-terminal sequence of an ACE-like enzyme determined in invertebrates.

  15. 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

    2015-10-01

    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

  16. 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

  17. 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.

  18. 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

  19. 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

    2016-01-01

    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. PMID:27588351

  20. New data about the functional morphology of the chaetiferous leech-like annelids Acanthobdella peledina (Grube, 1851) and Paracanthobdella livanowi (Epshtein, 1966) (Clitellata, Acanthobdellida).

    PubMed

    Bielecki, Aleksander; Cichocka, Joanna Maria; Jeleń, Iwona; Swiątek, Piotr; Płachno, Bartosz Jan; Pikuła, Dorota

    2014-05-01

    Approximately 130 individuals of Acanthobdella peledina and 100 individuals of Paracanthobdella livanowi were studied. Morphometric measurements were taken to explore the body form. The digestive and the reproductive systems of leech-like annelids were analyzed for the first time in such a high number of specimens. Observation of A. peledina and P. livanowi revealed crucial differences in the reproductive system of the analyzed taxa, mostly regarding variation in the shape of the testisacs and the length of the ovisacs. The results of a digestive system analysis suggest that blood-sucking parasites of the order Acanthobdellida may also lead a predatory lifestyle. The presented findings support the taxonomic division of the order Acanthobdellida into the families Acanthobdellidae and Paracanthobdellidae. Multiple similarities between Acanthobdellida and Hirudinida were also discussed.

  1. 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.

  2. Intracellular pH of giant salivary gland cells of the leech Haementeria ghilianii: regulation and effects on secretion.

    PubMed

    Wuttke, W A; Munsch, T; Berry, M S

    1994-04-01

    1. Intracellular pH (pHi) and membrane potential (Em) of giant salivary gland cells of the leech, Haementeria ghilianii, were measured with double-barrelled, neutral-carrier, pH-sensitive microelectrodes. 2. Em was -51 +/- 11.2 mV and pHi was 6.98 +/- 0.1 (mean +/- S.D., N = 41) in Hepes-buffered saline (nominally HCO3(-)-free; extracellular pH, pHe = 7.4). pHi was independent of Em. 3. Amiloride (2 mmol l-1) had no effect on resting pHi or on pHi recovery from an acid load (induced by the NH4+ pre-pulse technique). Removal of external Na+ produced a progressive acidification which was blocked by amiloride, and the drug also slowed the recovery of pHi on reintroduction of Na+. The results indicate the presence of an electroneutral Na+/H+ exchanger whose access to amiloride is competitively blocked by Na+. 4. In certain smaller cells of the gland, which probably form a separate population, removal of external Na+ did not affect pHi, and recovery from an acid load was blocked by amiloride. There may, therefore, be two types of Na+/H+ exchanger, differing in reversibility and sensitivity to amiloride. 5. Recovery of pHi from NH4(+)-induced acid loading was not affected by bicarbonate-buffered saline (2% CO2; 11 mmol l-1 HCO3-) or by addition of the anion-exchange blocker SITS (10(-4) mol l-1). This suggests that there is no significant contribution of a HCO3(-)-dependent transport mechanism to pHi regulation in the gland cells. 6. Removal of external Cl- slowly reduced pHi and there was a transient increase (overshoot) in pHi when Cl- was reintroduced. These effects of Cl- are probably explained by changes in the Na+ gradient. Intracellular Na+ and Cl- activities were measured with ion-selective microelectrodes. 7. Acidification with NH4+ was difficult, probably because of the cells' poor permeability to this ion. Attempts to introduce NH4+ via the Na+ pump or Na+/Cl- transporter were not successful. The H+/K+ ionophore nigericin (1 microgram ml-1), however, produced

  3. Assessment of genotoxic potency of sulfate-rich surface waters on medicinal leech and human leukocytes using different versions of the Comet assay.

    PubMed

    Mihaljević, Zlatko; Ternjej, Ivančica; Stanković, Igor; Ivković, Marija; Zelježić, Davor; Mladinić, Marin; Kopjar, Nevenka

    2011-07-01

    The aim of the present study was to investigate how exposure to sulfate-rich surface waters affects the level of primary DNA damage in hemocytes of leech Hirudo medicinalis. Samples of surface water were collected at two sites near a gypsum factory (Knin, Croatia) and two reference sites. In the laboratory, samples were subjected to detailed chemical analysis and used in toxicity testing. For that purpose, previously acclimatized individuals of H. medicinalis were sub-chronically exposed (for 28 days) to tested water samples. Levels of primary DNA damage were evaluated using the alkaline Comet assay in hemocytes collected on days 7, 14, 21 and 28 of exposure and compared with their baseline values. Genotoxic potency of the water sample with the highest sulfate concentration was further evaluated using the alkaline, neutral and hOGG1-modified Comet assay on human peripheral blood leukocytes exposed ex vivo for 30 min. The purpose was to explore which mechanisms are responsible for DNA damage. Chemical analysis revealed that sulfate concentrations in two water samples collected in Mali Kukar Lake (1630 mg/L SO₄) and Kosovčica River (823.3 mg/L SO₄) exceeded the WHO and US EPA defined limits for sulfate in drinking water. Increased levels of metals were found only in the water sample collected in Mali Kukar Lake. However, of the 65 elements analyzed, only nickel and titanium exceed the value legally accepted in Croatia for drinking water. The levels of DNA damage, estimated by the alkaline Comet assay in hemocytes of medicinal leech, increased with the duration of exposure to two sulfate-rich water samples. Since hemocytes responded sensitively to treatment, they could be used for biomonitoring purposes. As observed on treated human peripheral blood leukocytes, all versions of the Comet assay were effective in detecting DNA damage, which was measured in samples with sulfate concentrations equal to or higher than the legally accepted levels for drinking water

  4. 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

  5. Assessment of genotoxic potency of sulfate-rich surface waters on medicinal leech and human leukocytes using different versions of the Comet assay.

    PubMed

    Mihaljević, Zlatko; Ternjej, Ivančica; Stanković, Igor; Ivković, Marija; Zelježić, Davor; Mladinić, Marin; Kopjar, Nevenka

    2011-07-01

    The aim of the present study was to investigate how exposure to sulfate-rich surface waters affects the level of primary DNA damage in hemocytes of leech Hirudo medicinalis. Samples of surface water were collected at two sites near a gypsum factory (Knin, Croatia) and two reference sites. In the laboratory, samples were subjected to detailed chemical analysis and used in toxicity testing. For that purpose, previously acclimatized individuals of H. medicinalis were sub-chronically exposed (for 28 days) to tested water samples. Levels of primary DNA damage were evaluated using the alkaline Comet assay in hemocytes collected on days 7, 14, 21 and 28 of exposure and compared with their baseline values. Genotoxic potency of the water sample with the highest sulfate concentration was further evaluated using the alkaline, neutral and hOGG1-modified Comet assay on human peripheral blood leukocytes exposed ex vivo for 30 min. The purpose was to explore which mechanisms are responsible for DNA damage. Chemical analysis revealed that sulfate concentrations in two water samples collected in Mali Kukar Lake (1630 mg/L SO₄) and Kosovčica River (823.3 mg/L SO₄) exceeded the WHO and US EPA defined limits for sulfate in drinking water. Increased levels of metals were found only in the water sample collected in Mali Kukar Lake. However, of the 65 elements analyzed, only nickel and titanium exceed the value legally accepted in Croatia for drinking water. The levels of DNA damage, estimated by the alkaline Comet assay in hemocytes of medicinal leech, increased with the duration of exposure to two sulfate-rich water samples. Since hemocytes responded sensitively to treatment, they could be used for biomonitoring purposes. As observed on treated human peripheral blood leukocytes, all versions of the Comet assay were effective in detecting DNA damage, which was measured in samples with sulfate concentrations equal to or higher than the legally accepted levels for drinking water

  6. 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.

  7. 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

  8. 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

    2014-01-01

    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. PMID:25543724

  9. 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

  10. Investigation into the physiologies of Aeromonas veronii in vitro and inside the digestive tract of the medicinal leech using RNA-seq.

    PubMed

    Bomar, Lindsey; Graf, Joerg

    2012-08-01

    Host-associated microbial communities are widespread in nature and vital to the health and fitness of the host. Deciphering the physiology of the microbiome in vivo is critical to understanding the molecular basis of the symbiosis. Recently, the development and application of high-throughput sequencing techniques, particularly RNA-seq, for studying microbial communities has enabled researchers to address not only which microbes are present in a given community but also how the community functions. For microbes that can also be cultivated in the laboratory, RNA-seq provides the opportunity to identify genes that are differentially expressed during symbiosis by comparing in vitro to in vivo transcriptomes. In the current study, we used RNA-seq to identify genes expressed by the digestive-tract microbiome of the medicinal leech, Hirudo verbana, and by one of the two dominant symbionts, Aeromonas veronii, in a rich medium. We used a comparative approach to identify genes differentially expressed during symbiosis and gain insight into the symbiont's physiology in vivo. Notable findings include evidence for the symbionts experiencing environmental stress, performing arginine catabolism, and expressing noncoding RNAs that are implicated in stationary phase survival, a state in which A. veronii persists for months within the host.

  11. 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.

  12. 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

  13. The receptor protein tyrosine phosphatase HmLAR1 is up-regulated in the CNS of the adult medicinal leech following injury and is required for neuronal sprouting and regeneration.

    PubMed

    Sethi, Jasmine; Zhao, Bailey; Cuvillier-Hot, Virginie; Boidin-Wichlacz, Céline; Salzet, Michel; Macagno, Eduardo R; Baker, Michael W

    2010-12-01

    LAR-like receptor protein tyrosine phosphatases (RPTPs), which are abundantly expressed in the nervous systems of most if not all bilaterian animals thus far examined, have been implicated in regulating a variety of critical neuronal processes. These include neuronal pathfinding, adhesion and synaptogenesis during development and, in adult mammals, neuronal regeneration. Here we explored a possible role of a LAR-like RPTP (HmLAR1) in response to mechanical trauma in the adult nervous system of the medicinal leech. In situ hybridization and QPCR analyses of HmLAR1 expression in individual segmental ganglia revealed a significant up-regulation in receptor expression following CNS injury, both in situ and following a period in vitro. Furthermore, we observed up-regulation in the expression of the leech homologue of the Abelson tyrosine kinase, a putative signaling partner to LAR receptors, but not among other tyrosine kinases. The effects on neuronal regeneration were assayed by comparing growth across a nerve crush by projections of individual dorsal P neurons (P(D)) following single-cell injection of interfering RNAs against the receptor or control RNAs. Receptor RNAi led to a significant reduction in HmLAR1 expression by the injected cells and resulted in a significant decrease in sprouting and regenerative growth at the crush site relative to controls. These studies extend the role of the HmLARs from leech neuronal development to adult neuronal regeneration and provide a platform to investigate neuronal regeneration and gene regulation at the single cell level. PMID:20708686

  14. The receptor protein tyrosine phosphatase HmLAR1 is up-regulated in the CNS of the adult medicinal leech following injury and is required for neuronal sprouting and regeneration.

    PubMed

    Sethi, Jasmine; Zhao, Bailey; Cuvillier-Hot, Virginie; Boidin-Wichlacz, Céline; Salzet, Michel; Macagno, Eduardo R; Baker, Michael W

    2010-12-01

    LAR-like receptor protein tyrosine phosphatases (RPTPs), which are abundantly expressed in the nervous systems of most if not all bilaterian animals thus far examined, have been implicated in regulating a variety of critical neuronal processes. These include neuronal pathfinding, adhesion and synaptogenesis during development and, in adult mammals, neuronal regeneration. Here we explored a possible role of a LAR-like RPTP (HmLAR1) in response to mechanical trauma in the adult nervous system of the medicinal leech. In situ hybridization and QPCR analyses of HmLAR1 expression in individual segmental ganglia revealed a significant up-regulation in receptor expression following CNS injury, both in situ and following a period in vitro. Furthermore, we observed up-regulation in the expression of the leech homologue of the Abelson tyrosine kinase, a putative signaling partner to LAR receptors, but not among other tyrosine kinases. The effects on neuronal regeneration were assayed by comparing growth across a nerve crush by projections of individual dorsal P neurons (P(D)) following single-cell injection of interfering RNAs against the receptor or control RNAs. Receptor RNAi led to a significant reduction in HmLAR1 expression by the injected cells and resulted in a significant decrease in sprouting and regenerative growth at the crush site relative to controls. These studies extend the role of the HmLARs from leech neuronal development to adult neuronal regeneration and provide a platform to investigate neuronal regeneration and gene regulation at the single cell level.

  15. 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

  16. Expression levels of a LAR-like receptor protein tyrosine phosphatase correlate with neuronal branching and arbor density in the medicinal leech.

    PubMed

    Baker, Michael W; Macagno, Eduardo R

    2010-08-01

    LAR-like receptor protein tyrosine phosphatases (RPTPs), which are reported to be highly expressed in the nervous systems of most bilaterian animals, have been implicated in the regulation of critical developmental processes, such as neuronal pathfinding, cell adhesion and synaptogenesis. Here we report that two LAR-like RPTPs in the medicinal leech, HmLAR1 and HmLAR2, play roles in regulating the size and density of neuronal arbors within the developing nervous system and in the body wall. Employing single-cell RNAi knockdown and transgene expression techniques, we demonstrate that the expression level of HmLAR1 is directly correlated with the density of an identified neuron's arborization. Knocking down HmLAR1 mRNA levels in the mechanosensory pressure (P) neurons produces a reduced central arbor and a smaller arbor in the peripheral body wall, with fewer terminal branches. By contrast, overexpression of this receptor in a P cell leads to extensive neuronal sprouting, including many supernumerary neurites and terminal branches as well as, in some instances, the normal monopolar morphology of the P cell becoming multipolar. We also report that induced neuronal sprouting requires the expression of the receptor's membrane tethered ectodomain, including the NH(2)-Ig domains, but not of the intracellular phosphatase domains of the receptor. Interestingly, sprouting could be elicited upon ectopic expression of HmLAR1 and the related RPTP, HmLAR2 in the P and other neurons, including those that do not normally express either RPTP, suggesting that the substrates involved in HmLAR-induced sprouting are present in most neurons irrespective of whether they normally express these LAR-like RPTPs. Our data are consistent with the hypothesis that the receptors' ectodomains promote an adhesive interaction that enhances the maintenance of new processes.

  17. 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. PMID:18579654

  18. [Use of the most recent reagent (CuFL) for stimulation of NO synthesis by the medicinal leech salivary cell secretion in the cultures of human endothelium cells (HUVEC) and in rat cardiomiocytes].

    PubMed

    Baskova, I P; Alekseeva, A Iu; Kostiuk, S V; Neverova, M E; Smirnova, T D; Veĭko, N N

    2012-01-01

    The medicinal leech salivary cell secretion (SCS) may stimulate NO-production in cultures of human endothelium cells (HUVEC) and rat cardiomiocytes (RCM). This effect was detected using a NO specific reagent, - the complex Cu2+ with a fluorescein derivative (Cu-Fl). NO had also been detected in the cells by fluorescent electronic microscopy and determined quantitatively in the cells and in culture fluid by the fluorescence method. SCS stimulated NO synthesis in HUVEC cells (but not in RCM) is accompanied by NO release into intercellular space. Localization of NO synthesis centers is presented and it is shown that the increase in NO levels during the SCS action on HUVEC and RCM is associated with the increase in the activity of eNOS/nNOS, but not iNOS. In endothelial cells SCS activates nitrosylation processes, assessed by the increase of nitrite-ions in the culture medium. It is therefore important to use Cu-Fl, other than Griss-reagent, during the first hour of analysis of NO synthesis. The NO-depended mechanism of SCS action on endothelial cells might be a factor in providing of its positive action in hirudotheraphy.

  19. Simultaneous measurements of intracellular pH in the leech giant glial cell using 2',7'-bis-(2-carboxyethyl)-5,6-carboxyfluorescein and ion-sensitive microelectrodes.

    PubMed

    Nett, W; Deitmer, J W

    1996-07-01

    We have employed two independent techniques to measure the intracellular pH (pHi) in giant glial cells of the leech Hirudo medicinalis, using the fluorescent dye 2',7'-bis-(2-carboxyethyl)-5,6-carboxyfluorescein (BCECF) and double-barreled neutral-carrier, pH-sensitive microelectrodes, which also record the membrane potential. We have compared two procedures for calibrating the ratio of the BCECF signal, excited at 440 nm and 495 nm: 1) the cell membrane was H(+)-permeabilized with nigericin in high-K+ saline at different external pH (pHo) values, and 2) the pHi of intact cells was perturbed in CO2/HCO3(-) -buffered saline of different pH, and the BCECF ratio was calibrated according to a simultaneous microelectrode pH reading. As indicated by the microelectrode measurements, the pHi did not fully equilibrate to the pHo values in nigericin-containing, high-K+ saline, but deviated by -0.12 +/- 0.02 (mean +/- SEM, n = 37) pH units. In intact cells, the microelectrode readings yielded up to 0.15 pH unit lower values than the calibrated BCECF signal. In addition, larger dye injections into the cells (> 100 microM) caused an irreversible membrane potential loss indicative of some damage to the cells. The amplitude and kinetics of slow pHi changes were equally followed by both sensors, and the dye ratio recorded slightly higher amplitudes during faster pHi shifts as induced by the addition and removal of NH4+.

  20. Simultaneous measurements of intracellular pH in the leech giant glial cell using 2',7'-bis-(2-carboxyethyl)-5,6-carboxyfluorescein and ion-sensitive microelectrodes.

    PubMed Central

    Nett, W; Deitmer, J W

    1996-01-01

    We have employed two independent techniques to measure the intracellular pH (pHi) in giant glial cells of the leech Hirudo medicinalis, using the fluorescent dye 2',7'-bis-(2-carboxyethyl)-5,6-carboxyfluorescein (BCECF) and double-barreled neutral-carrier, pH-sensitive microelectrodes, which also record the membrane potential. We have compared two procedures for calibrating the ratio of the BCECF signal, excited at 440 nm and 495 nm: 1) the cell membrane was H(+)-permeabilized with nigericin in high-K+ saline at different external pH (pHo) values, and 2) the pHi of intact cells was perturbed in CO2/HCO3(-) -buffered saline of different pH, and the BCECF ratio was calibrated according to a simultaneous microelectrode pH reading. As indicated by the microelectrode measurements, the pHi did not fully equilibrate to the pHo values in nigericin-containing, high-K+ saline, but deviated by -0.12 +/- 0.02 (mean +/- SEM, n = 37) pH units. In intact cells, the microelectrode readings yielded up to 0.15 pH unit lower values than the calibrated BCECF signal. In addition, larger dye injections into the cells (> 100 microM) caused an irreversible membrane potential loss indicative of some damage to the cells. The amplitude and kinetics of slow pHi changes were equally followed by both sensors, and the dye ratio recorded slightly higher amplitudes during faster pHi shifts as induced by the addition and removal of NH4+. PMID:8804622

  1. 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.

  2. Back to past leeches: repeated phlebotomies and cardiovascular risk

    PubMed Central

    2012-01-01

    In patients with metabolic syndrome, body iron overload exacerbates insulin resistance, impairment of glucose metabolism, endothelium dysfunction and coronary artery responses. Conversely, iron depletion is effective to ameliorate glucose metabolism and dysfunctional endothelium. Most of its effectiveness seems to occur through the amelioration of systemic and hepatic insulin resistance. In a study published by BMC Medicine, Michalsen et al. demonstrated a dramatic improvement of blood pressure, serum glucose and lipids after removing 550 to 800 ml of blood in subjects with metabolic syndrome. This effect was apparently independent of changes in insulin resistance, in contrast to previous cross-sectional and cohort studies investigating the association between iron overload, insulin resistance and cardiovascular disease. Despite drawbacks in the study design, its findings may lead the way to investigations aimed at exploring iron-dependent regulatory mechanisms of vascular tone in healthy individuals and patients with metabolic disease, thus providing a rationale for novel preventive and therapeutic strategies to counteract hypertension. Please see related article: http://www.biomedcentral.com/1741-7015/10/54 PMID:22647488

  3. Destabilase-lysozyme of medicinal leech. Multifunctionality of recombinant protein.

    PubMed

    Zavalova, L L; Lazarev, V N; Levitsky, S A; Yudina, T G; Baskova, I P

    2010-09-01

    Preparation and purification of a recombinant protein are described along with characteristics of its specific (for ε-(γ-Glu)-Lys and D-dimer substrates) and nonspecific (for L-γ-Glu-pNA) isopeptidase activities; the absence of peptidase function for α-(α-Glu)-Lys substrate is noted. It is shown that the protein exhibits muramidase (cell walls of Micrococcus lysodeikticus) and specific glycosidase activities. The latter was determined towards the fluorogenic substrate 4-methylumbelliferyl-tetra-N-acetyl-β-chitotetraoxide. Antimicrobial activity of recombinant destabilase-lysozyme protein (recDest-Lys) and its 11-membered amphipathic peptide was revealed towards cells of the strict anaerobic Archaean Methanosarcina barkeri, whose cell walls contain no murein. Possible mechanisms of the effect of recDest-Lys on these cells are discussed.

  4. 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

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

    PubMed

    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.

  6. 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

    ... reservoir; logging. 207.330 Section 207.330 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT... reservoir; logging. (a) Parties engaged in the transportation of loose logs, timbers, and rafts of...

  7. 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

    ..., launches, or other craft desiring to pass through a body of floating logs, poles, or ties shall be given... to maintain a clear navigable channel width of not less than 20 feet. (e) Parties using the river for... tie up where there will be less than 50 feet of clear waterway between their raft and the other...

  8. 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

    ..., launches, or other craft desiring to pass through a body of floating logs, poles, or ties shall be given... to maintain a clear navigable channel width of not less than 20 feet. (e) Parties using the river for... tie up where there will be less than 50 feet of clear waterway between their raft and the other...

  9. 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.

  10. 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,...

  11. Oral, direct thrombin and factor Xa inhibitors: the replacement for warfarin, leeches, and pig intestines?

    PubMed

    Straub, Alexander; Roehrig, Susanne; Hillisch, Alexander

    2011-05-01

    To prevent thromboses after surgery, patients have until now had to inject themselves daily with heparin. For stroke prophylaxis in atrial fibrillation, patients take vitamin K antagonists of the coumarin type, which have a narrow therapeutic window and whose dosage must be regularly monitored. In order to improve the standard of therapy in thromboembolic diseases such as deep-vein thrombosis, pulmonary embolism, and stroke in atrial fibrillation, intensive research has been carried out over the last decade in the search for new, orally active thrombin and factor Xa inhibitors. A number of these compounds are already on the market or are in advanced clinical development; they could revolutionize the anticoagulant market.

  12. "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…

  13. A redescription of the Australian leech Placobdelloides bancrofti with new records of its distribution.

    PubMed

    McKenna, S A; Betts, D A; Pong, W W; Govedich, F R; Barton, D P

    2005-02-01

    Placobdelloides bancrofti (Best, 1931) Sawyer, 1986 (Euhirudinea: Glossiphoniidae) is recorded for the first time from a location in North Queensland, Australia. Placobdelloides bancrofti was found feeding on the freshwater turtle Emydura krefftii and was collected from a new host species Elseya latisternum. Examination of live individuals enabled us to document external coloration and markings for the first time. Clarification of the original description of P. bancrofti is made, correcting the location of the anal pore, and then the taxonomic history of this species is discussed. PMID:15856883

  14. 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.

  15. The LEECH Exoplanet Imaging Survey. Further constraints on the planet architecture of the HR 8799 system (Corrigendum)

    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.

    2015-07-01

    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 Astrofisica, Italy; LBT Beteiligungsgesellschaft, Germany, representing the Max-Planck Society, the Astrophysical Institute Potsdam, and Heidelberg University; The Ohio State University, and The Research Corporation, on behalf of The University of Notre Dame, University of Minnesota, and University of Virginia.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  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. History of evidence-based medicine. Oranges, chloride of lime and leeches: barriers to teaching old dogs new tricks.

    PubMed

    Doherty, Steven

    2005-08-01

    Knowledge translation is the process of taking evidence from research and applying it in clinical practice. In this article I will cite some pivotal moments in the history of medicine to highlight the difficulties and delays associated with getting evidence into practice. These historical examples have much in common with modern medical trials and quality improvement processes. I will also review the reasons why evidence is not used and consider what factors facilitate the uptake of evidence. Understanding these concepts will make it easier for individual clinicians and institutions to change clinical behaviour and provide a starting point for those looking at implementing 'new' practices, new therapies and clinical guidelines. Finally, I will offer a list of criteria that clinicians might choose to consider when deciding on whether or not to adopt a new practice, treatment or concept. PMID:16091093

  2. 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.

  3. [Infections Associated with Treatment with Hirudo medicinalis - Report of Two Cases and Review of the Literature].

    PubMed

    Reese, K; Gümbel, D; Seifert, J; Daeschlein, G; Napp, M; Ekkernkamp, A

    2015-06-01

    Medicinal leeches are well-established for promoting venous drainage in transplants/flaps and analgesia in osteoarthritis. Although medicinal leeches are bred and kept under controlled conditions, they are colonised by a genuine species-specific bacterial flora. Therapeutic application of leeches implies skin penetration carrying an a priori risk of infection. We report 2 cases with different indications for medicinal leech therapy. In both cases wound infection occurred in close temporal and spatial correlation or with evidence of a leech-associated germ that could be treated successfully. An unclarified complication rate warrants strict indications for the application of medicinal leeches. Preventive measures are currently tested.

  4. Suckers for Science.

    ERIC Educational Resources Information Center

    Haugen, Heidi Helene

    2001-01-01

    Introduces an inquiry-based program on leeches that features five components: (1) engagement; (2) exploration; (3) explanation; (4) evaluation; and (5) extension/elaboration. Investigates the anatomy and environmental conditions of leeches. (YDS)

  5. 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...

  6. Computational model of touch sensory cells (T Cells) of the leech: role of the afterhyperpolarization (AHP) in activity-dependent conduction failure.

    PubMed

    Cataldo, Enrico; Brunelli, Marcello; Byrne, John H; Av-Ron, Evyatar; Cai, Yidao; Baxter, Douglas A

    2005-01-01

    Bursts of spikes in T cells produce an AHP, which results from activation of a Na+/K+ pump and a Ca2+-dependent K+ current. Activity-dependent increases in the AHP are believed to induce conduction block of spikes in several regions of the neuron, which in turn, may decrease presynaptic invasion of spikes and thereby decrease transmitter release. To explore this possibility, we used the neurosimulator SNNAP to develop a multi-compartmental model of the T cell. The model incorporated empirical data that describe the geometry of the cell and activity-dependent changes of the AHP. Simulations indicated that at some branching points, activity-dependent increases of the AHP reduced the number of spikes transmitted from the minor receptive fields to the soma and beyond. More importantly, simulations also suggest that the AHP could modulate, under some circumstances, transmission from the soma to the synaptic terminals, suggesting that the AHP can regulate spike conduction within the presynaptic arborizations of the cell and could in principle contribute to the synaptic depression that is correlated with increases in the AHP.

  7. 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

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

    PubMed

    Raele, Donato Antonio; Galante, Domenico; Cafiero, Maria Assunta

    2015-10-01

    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.

  9. 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

  10. 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 ...

  11. High prevalence of buccal ulcerations in largemouth bass, Micropterus salmoides (Centrarchidae) from Michigan inland lakes associated with Myzobdella lugubris Leidy 1851 (Annelida: Hirudinea).

    PubMed

    Faisal, M; Schulz, C; Eissa, A; Whelan, G

    2011-02-01

    Widespread mouth ulcerations were observed in largemouth bass collected from eight inland lakes in the Lower Peninsula of Michigan during the summer months of 2002 and 2003. These ulcerations were associated with, and most likely caused by, leech parasitism. Through the use of morphological dichotomous keys, it was determined that all leeches collected are of one species: Myzobdella lugubris. Among the eight lakes examined, Lake Orion and Devils Lake had the highest prevalence of leech parasitism (34% and 29%, respectively) and mouth ulcerations (53% and 68%, respectively). Statistical analyses demonstrated that leech and ulcer prevalence varied significantly from one lake to the other. Additionally, it was determined that the relationship between the prevalence of ulcers and the prevalence of leech attachment is significant, indicating that leech parasitism is most likely the cause of ulceration. The ulcers exhibited deep hemorrhagic centers and raised irregular edges. Affected areas lost their epithelial lining and submucosa, with masses of bacteria colonizing the damaged tissues. Since largemouth bass is a popular global sportfish and critical to the food web of inland lakes, there are concerns that the presence of leeches, damaged buccal mucosa, and general unsightliness may negatively affect this important sportfishery.

  12. 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

  13. Head lice

    MedlinePlus

    ... PA: Elsevier Saunders; 2015:chap 294. Elston DM. Arthropods and leeches. In: Goldman L, Schafer AI, eds. ... 15. Kliegman RM, Stanton BF, St Geme JW. Arthropods bites and infestations. In: Kliegman RM, Stanton BF, ...

  14. 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. PMID:25152938

  15. 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. PMID:25115059

  16. 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.

  17. 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. PMID:26034123

  18. 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.

  19. 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.

  20. Reply to comment by P.J. O'Brien on: “The onset of India-Asia continental collision: Early, steep subduction required by the timing of UHP metamorphism in the western Himalaya” by Mary L. Leech, S. Singh, A.K. Jain, Simon L. Klemperer and R.M. Manickavasagam, Earth Planetary Science Letters 234 (2005) 83-97

    NASA Astrophysics Data System (ADS)

    Leech, Mary L.; Singh, Sandeep; Jain, A. K.; Klemperer, Simon L.; Manickavasagam, R. M.

    2006-05-01

    We thank O'Brien for directing our attention to his recent publication on modeling of diffusion in garnets, including one garnet from the Tso Morari Complex [1], and allowing us to show how our data and existing interpretation are consistent with his model. It seems O'Brien wants the timing of ultrahigh-pressure metamorphism (UHPM) in the Tso Morari Complex to be the same as the well-established 46 Ma UHPM event in Kaghan over 500 km to the northwest (e.g., [2]), and is attempting to reinterpret our U-Pb zircon dating from the Tso Morari Complex to fit his notion. But rather than fight the age data, why not develop a model that fits the data? Guillot et al. [3] describe a warped geometry of the Indian subduction plane that places the Tso Morari Complex and Kaghan at different depths based on their ages of UHPM; this model allows for a 55-54 Ma UHP event in the Tso Morari Complex and a 46 Ma event in Kaghan [4].

  1. The Hirudo medicinalis species complex

    NASA Astrophysics Data System (ADS)

    Kutschera, U.

    2012-05-01

    Recently, Hildebrandt and Lemke (Naturwissenschaften 98:995-1008, 2011) argued that the taxonomic status of the three European medicinal leeches, Hirudo medicinalis Linnaeus 1758, Hirudo verbana Carena 1820, and Hirudo orientalis Utevsky and Trontelj (Parasitol Res 98:61-66, 2005) is "questionable" since "all three species interbreed in the laboratory". This statement is in conflict with data published by Elliott and Kutschera (Freshwater Reviews 4:21-41, 2011), indicating that these leeches, which are reciprocally copulating hermaphrodites, represent reproductively isolated biospecies. Here, I summarize evidence indicating that these three European taxa, plus the North African "dragon leech" ( Hirudo troctina Johnson 1816), must be interpreted as a complex of closely related species, and that the economically most important taxon H. verbana is polymorphic.

  2. 33 CFR 207.340 - Reservoirs at headwaters of the Mississippi River; use and administration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... February 11, 1931, which together with all subsequent amendments are hereby revoked and the following... 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....

  3. 33 CFR 207.340 - Reservoirs at headwaters of the Mississippi River; use and administration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... February 11, 1931, which together with all subsequent amendments are hereby revoked and the following... 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....

  4. Lexical Bundle Analysis in Mathematics Classroom Discourse: The Significance of Stance

    ERIC Educational Resources Information Center

    Herbel-Eisenmann, Beth; Wagner, David; Cortes, Viviana

    2010-01-01

    In this article, we introduce the lexical bundle, defined by corpus linguists as a group of three or more words that frequently recur together, in a single group, in a particular register (Biber, Johansson, Leech, Conrad, & Finegan, 2006; Cortes, "English for Specific Purposes" 23:397-423, 2004). Attention to lexical bundles helps to explore…

  5. 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…

  6. 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,…

  7. Characterization and immune function of two intracellular sensors, HmTLR1 and HmNLR, in the injured CNS of an invertebrate.

    PubMed

    Cuvillier-Hot, Virginie; Boidin-Wichlacz, Céline; Slomianny, Christian; Salzet, Michel; Tasiemski, Aurélie

    2011-02-01

    Unlike mammals, the CNS of the medicinal leech can regenerate damaged neurites, thus restoring neural functions. Our group recently demonstrated that the injured leech nerve cord is able to mount an immune response, which promotes the regenerative processes. This defense mechanism is microorganism-specific, suggesting that the leech CNS is able to discriminate among microbial components. We report here the characterization of two receptors potentially implicated in this detection: HmTLR1 and HmNLR. Interestingly, HmTLR1 presents an endosomal distribution in neurons and appears as a chimera combining the mammalian intraendosomal domain of TLR3 and the cytoplasmic section of TLR13, while HmNLR is cytosolic and has the highest homology to NLRC3 receptors. Both receptors show patterns of induction upon stimulation that suggest their involvement in the leech neuroimmune response. This work constitutes the first demonstration in an invertebrate of (i) an intracellular TLR and (ii) a cytosolic PRR related to the NLR family. PMID:20920526

  8. 76 FR 45570 - Consumer Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-29

    ... Keller National Center for Deaf-Blind Youth and Adults--Dorthy Walt Media Literacy Project--Andrea... and released January 11, 2011, as published at 76 FR 3633, January 20, 2011, the Commission announced... E. Leech Consumer Electronics Association--Julie Kearney Center for Media Justice--Amalia...

  9. 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

  10. Doctoral Students' Reasons for Reading Empirical Research Articles: A Mixed Analysis

    ERIC Educational Resources Information Center

    Burgess, Melissa L.; Benge, Cindy; Onwuegbuzie, Anthony J.; Mallette, Marla H.

    2012-01-01

    Little is known about reading ability among doctoral students. Thus, we used a fully mixed concurrent equal status design (Leech & Onwuegbuzie, 2009) to examine 205 doctoral students in the College of Education and their reasons for reading research articles. A thematic analysis revealed 5 themes (subsumed by 2 meta-themes) explaining reasons…

  11. 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…

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

    PubMed Central

    Hooper, Scott L.; Guschlbauer, Christoph; Schmidt, Joachim; Büschges, Ansgar

    2015-01-01

    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 14C-glucose electrode fill confirmed earlier work showing substantial leak from sharp electrodes. Sharp electrode work should thus be performed with cytoplasm-matched electrode fills. PMID:26063785

  13. 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

  14. 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.

  15. 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

  16. 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. PMID:26063785

  17. 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

  18. 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

  19. 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

  20. 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.

  1. The James Webb Space Telescope: Capabilities for Transiting Exoplanet Observations

    NASA Astrophysics Data System (ADS)

    Clampin, Mark

    2015-07-01

    Emission from zodiacal dust disks in other planetary systems, is both a noise source for future exoplanet imaging missions and a signpost of rocky material in, or near, the habitable zone. The LBT Interferometer has been designed to discover and characterize faint exozodiacal dust around nearby stars. I will summarize what we currently know about this dust and what we aim to learn with the LBTI's survey, the Hunt for Observable Signatures of Terrestrial Planets (HOSTS), along with its companion survey, LEECH, designed to identify wide-orbit giant planets a similar sample of stars. As an example of this, I will discuss the characterization the beta Leo system with both HOSTS and LEECH.

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

    PubMed

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

    2015-07-01

    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.

  3. 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

  4. 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).

  5. 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

  6. [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.

  7. Mechanisms underlying rhythmic locomotion: dynamics of muscle activation

    PubMed Central

    Chen, Jun; Tian, Jianghong; Iwasaki, Tetsuya; Friesen, W. Otto

    2011-01-01

    SUMMARY We have studied the dynamical properties of tension development in leech longitudinal muscle during swimming. A new method is proposed for modeling muscle properties under functionally relevant conditions where the muscle is subjected to both periodic activation and rhythmic length changes. The ‘dual-sinusoid’ experiments were conducted on preparations of leech nerve cord and body wall. The longitudinal muscle was activated periodically by injection of sinusoidal currents into an identified motoneuron. Simultaneously, sinusoidal length changes were imposed on the body wall with prescribed phase differences (12 values equally spaced over 2π radians) with respect to the current injection. Through the singular value decomposition of appropriately constructed tension data matrices, the leech muscle was found to have a multiplicative structure in which the tension was expressed as the product of activation and length factors. The time courses of activation and length factors were determined from the tension data and were used to develop component models. The proposed modeling method is a general one and is applicable to contractile elements for which the effects of series elasticity are negligible. PMID:21562183

  8. Prodynorphin in invertebrates.

    PubMed

    Salzet, M; Stefano, G

    1997-12-01

    We have characterized a prodynorphin-like molecule in an invertebrate, specifically in the rhynchobdellid leech Theromyzon tessulatum. The 14270 Da protein was purified by gel permeation chromatography, anti-leucine-enkephalin-affinity column separation followed by reverse-phase HPLC. Its complete characterization was performed by Edman degradation, enzymatic treatments, and matrix assisted laser-desorption time of flight mass spectrometry. This 119 amino-acid protein exhibits 28.8% sequence identity with rat prodynorphin, 22.9% with human prodynorphin, and 21.8% with the pig molecule. Within the leech precursor, alpha-Neo-endorphin, dynorphin-A, and dynorphin B-like peptides are present at the C-terminus as in vertebrate prodynorphin. These biological active peptides exhibit 100%, 50%, and 76.6% sequence identity with their counterparts in mammals, respectively. The amount of leucine-enkephalin is identical to that found in vertebrates. Leech prodynorphin is distinguished from that found in mammals in that the N-terminus is shorter. This report constitutes the first complete biochemical characterization of a prodynorphin in invertebrates.

  9. 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

  10. 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.

  11. 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

  12. [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.

  13. 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

  14. New U-Pb Age and Trace Element Composition of Young Metamorphic Zircon Rims from the UHP Tso Morari Complex, NW Himalaya, Distinguishes Peak from Retrograde Metamorphism

    NASA Astrophysics Data System (ADS)

    Leech, M. L.; Coble, M. A.; Singh, S.; Guillot, S.; Jain, A. K.

    2014-12-01

    The ultrahigh-pressure (UHP) Tso Morari Complex (TMC) sits in the footwall of the Indus-Yarlung suture zone in the NW Himalaya. The timing of metamorphism during subduction and exhumation in the complex is critical to constraining the age of the India-Asia collision. de Sigoyer et al. (2000) and Leech et al. (2005) reported mean U-Pb ages for thin outer rims of sectioned zircon between 55 ± 6 Ma and 53.3 ± 0.7 Ma, respectively, for the age of peak UHP through retrograde metamorphism, and Leech et al. (2005) used these data to calculate the minimum age for the start of continental subduction at 57 ± 1 Ma. Recently published results for the TMC have reignited debate on the age of metamorphism and thus, the timing of India-Asia collision. We used the same TM38 sample analyzed for the results described in Leech et al. (2005) and performed new SIMS U-Pb depth-profiling analyses to target only the outermost ~1.5 micron rims of zircon. Our results yield a mean age of 44.9 ± 0.7 Ma; adjacent spots for REE analyses yielded positive, enriched HREE profiles with negative Eu anomalies and corresponding Ti-in-zircon temperatures of ~550° to 680° C. Sharp boundaries between zircon domains are clearly resolved with CL and BSE imaging of TM38 zircons, and there is a large age difference between rims and protolith core ages; any mixing during depth-profiling through rims is clear. The positive HREE profiles imply the period of zircon growth in the TMC at c. 45 Ma to be retrograde. We suggest that the 47-43 Ma peak ages and flat heavy REE profiles with no Eu anomaly recently reported by Donaldson et al. (2013) on sectioned zircons, and interpreted as the age of UHP metamorphism of the TMC, may actually represent mixing between zircon rims and cores. The Leech et al. (2005) collision age of 57 ± 1 Ma assumed the TMC represents the leading edge of India. However, numerical modeling of Warren et al. (2008) suggests all exhumed material is derived from the central part of the pro

  15. 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.

  16. Botanical repellents and pesticides traditionally used against hematophagous invertebrates in Lao People's Democratic Republic: a comparative study of plants used in 66 villages.

    PubMed

    de Boer, Hugo; Vongsombath, Chanda; Pålsson, Katinka; Björk, Lars; Jaenson, Thomas G T

    2010-05-01

    Hematophagous parasites such as leeches, ticks, mites, lice, bedbugs, mosquitoes, and myiasis-producing fly larvae are common health problems in Lao People's Democratic Republic. Several arthropod-borne infections, e.g., malaria, dengue fever, and Japanese encephalitis, are endemic there. Effective vector control methods including the use of pesticides, insecticide-treated bed nets, and synthetic and plant-based repellents are important means of control against such invertebrates and the pathogens they may transmit or directly cause. In this study, we documented traditional knowledge on plants that are used to repel or kill hematophagous arthropods, including mosquitoes, bedbugs, human lice, mites and ticks, fly larvae, and blood-sucking leeches. Structured interviews were carried out in 66 villages comprising 17 ethnic groups, covering a range of cultures, throughout Lao People's Democratic Republic. A total of 92 plant species was recorded as traditional repellents (including plants for pesticidal usages) in 123 different plant-ectoparasite combinations. The number and species of plants, and animal taxa repelled (or killed) per plant species differed per region, village, and ethnic group. Traditional use was confirmed in the scientific literature for 74 of these plant species, and for an additional 13 species using literature on closely related species. The use of botanical repellents and pesticides from many plant species is common and widespread in the Lao countryside. In the future, the identification of the active components in certain plants to develop more optimal, inexpensive repellents, insecticides, acaricides, or antileech compounds as alternatives to synthetic repellents/pesticides against blood-feeding insects, ticks, mites, and leeches is warranted. PMID:20496588

  17. Ultrastructural analysis of apoptosis and autophagy in the midgut epithelium of Piscicola geometra (Annelida, Hirudinida) after blood feeding.

    PubMed

    Rost-Roszkowska, M M; Świątek, P; Poprawa, I; Rupik, W; Swadźba, E; Kszuk-Jendrysik, M

    2015-09-01

    Cell death in the endodermal region of the digestive tract of the blood-feeding leech Piscicola geometra was analyzed using light and transmission electron microscopes and the fluorescence method. Sexually mature specimens of P. geometra were bred under laboratory conditions and fed on Danio rerio. After copulation, the specimens laid cocoons. The material for our studies were non-feeding juveniles collected just after hatching, non-feeding adult specimens, and leeches that had been fed with fish blood (D. rerio) only once ad libitum. The fed leeches were prepared for our studies during feeding and after 1, 3, 7, and 14 days (not sexually mature specimens) and some weeks after feeding (the sexually mature). Autophagy in all regions of the endodermal part of the digestive system, including the esophagus, the crop, the posterior crop caecum (PCC), and the intestine was observed in the adult non-feeding and feeding specimens. In fed specimens, autophagy occurred at very high levels--in 80 to 90 % of epithelial cells in all four regions. In contrast, in adult specimens that did not feed, this process occurred at much lower levels--about 10 % (esophagus and intestine) and about 30 % (crop and PCC) of the midgut epithelial cells. Apoptosis occurred in the feeding adult specimens but only in the crop and PCC. However, it was absent in the non-feeding adult specimens and the specimens that were collected during feeding. Moreover, neither autophagy nor apoptosis were observed in the juvenile, non-feeding specimens. The appearance of autophagy and apoptosis was connected with feeding on toxic blood. We concluded that autophagy played the role of a survival factor and was involved in the protection of the epithelium against the products of blood digestion. Quantitative analysis was prepared to determine the number of autophagic and apoptotic cells.

  18. Botanical repellents and pesticides traditionally used against hematophagous invertebrates in Lao People's Democratic Republic: a comparative study of plants used in 66 villages.

    PubMed

    de Boer, Hugo; Vongsombath, Chanda; Pålsson, Katinka; Björk, Lars; Jaenson, Thomas G T

    2010-05-01

    Hematophagous parasites such as leeches, ticks, mites, lice, bedbugs, mosquitoes, and myiasis-producing fly larvae are common health problems in Lao People's Democratic Republic. Several arthropod-borne infections, e.g., malaria, dengue fever, and Japanese encephalitis, are endemic there. Effective vector control methods including the use of pesticides, insecticide-treated bed nets, and synthetic and plant-based repellents are important means of control against such invertebrates and the pathogens they may transmit or directly cause. In this study, we documented traditional knowledge on plants that are used to repel or kill hematophagous arthropods, including mosquitoes, bedbugs, human lice, mites and ticks, fly larvae, and blood-sucking leeches. Structured interviews were carried out in 66 villages comprising 17 ethnic groups, covering a range of cultures, throughout Lao People's Democratic Republic. A total of 92 plant species was recorded as traditional repellents (including plants for pesticidal usages) in 123 different plant-ectoparasite combinations. The number and species of plants, and animal taxa repelled (or killed) per plant species differed per region, village, and ethnic group. Traditional use was confirmed in the scientific literature for 74 of these plant species, and for an additional 13 species using literature on closely related species. The use of botanical repellents and pesticides from many plant species is common and widespread in the Lao countryside. In the future, the identification of the active components in certain plants to develop more optimal, inexpensive repellents, insecticides, acaricides, or antileech compounds as alternatives to synthetic repellents/pesticides against blood-feeding insects, ticks, mites, and leeches is warranted.

  19. Patterns of presynaptic activity and synaptic strength interact to produce motor output.

    PubMed

    Wright, Terrence Michael; Calabrese, Ronald L

    2011-11-30

    Motor neuron activity is coordinated by premotor networks into a functional motor pattern by complex patterns of synaptic drive. These patterns combine both the temporal pattern of spikes of the premotor network and the profiles of synaptic strengths (i.e., conductances). Given the complexity of premotor networks in vertebrates, it has been difficult to ascertain the relative contributions of temporal patterns and synaptic strength profiles to the motor patterns observed in these animals. Here, we use the leech (Hirudo sp.) heartbeat central pattern generator (CPG), in which we can measure both the temporal pattern and the synaptic strength profiles of the entire premotor network and the motor outflow in individual animals. In this system, a series of motor neurons all receive input from the same premotor interneurons of the CPG but must be coordinated differentially to produce a functional pattern. These properties allow a theoretical and experimental dissection of the rules that govern how temporal patterns and synaptic strength profiles are combined in motor neurons so that functional motor patterns emerge, including an analysis of the impact of animal-to-animal variation in input to such variation in output. In the leech, segmental heart motor neurons are coordinated alternately in a synchronous and peristaltic pattern. We show that synchronous motor patterns result from a nearly synchronous premotor temporal pattern produced by the leech heartbeat CPG. For peristaltic motor patterns, the staggered premotor temporal pattern determines the phase range over which segmental motor neurons can fire while synaptic strength profiles define the intersegmental motor phase progression realized.

  20. 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.

  1. 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)

  2. 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.

  3. 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.

  4. A Silurian soft-bodied biota

    USGS Publications Warehouse

    Mikulic, Donald G.; Briggs, D.E.G.; Kluessendorf, Joanne

    1985-01-01

    A new Silurian (Llandoverian) biota from Wisconsin with a significant soft-bodied and lightly sclerotized component is dominated by arthropods and worms. The fauna includes the earliest well-preserved xiphosure, a possible marine uniramian, three new arthropods of uncertain affinity, and possibly the first Paleozoic leech. This may be only the second locality to yield a conodont animal. Lack of a normal shelly fauna suggests an unusual environment. The discovery adds significantly to the few such exceptionally preserved faunas known from Lower Paleozoic rocks.

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

    PubMed

    Wong, Kam Lok; Wong, Ricky Ngok Shun; Zhang, Liang; Liu, Wing Keung; Ng, Tzi Bun; Shaw, Pang Chui; Kwok, Philip Chi Lip; Lai, Yau Ming; Zhang, Zhang Jin; Zhang, Yanbo; Tong, Yao; Cheung, Ho-Pan; Lu, Jia; Sze, Stephen Cho Wing

    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

  6. 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.

  7. Innovative techniques in preventing and salvaging neurovascular pedicle flaps in reconstructive foot and ankle surgery.

    PubMed

    Zgonis, Thomas; Stapleton, John J

    2008-04-01

    Pedicle flaps to cover soft tissue defects of the foot, ankle, and lower extremity are invaluable. However, venous congestion and flap necrosis, a common complication, poses greater morbidity to the patient as few remaining options for attempted limb salvage remain. The authors discuss how to prevent flap failure by allowing close observation and strict offloading of the pedicle flap through current external fixation designs. This article also discusses the role of medicinal leeches in reestablishing blood flow through the pedicle flap to prevent tissue necrosis. In addition, the use of hydrosurgery as an innovative technique offers the surgeon another option if faced with pedicle flap necrosis. PMID:19825700

  8. The buccal gland of Lampetra japonica is a source of diverse bioactive proteins.

    PubMed

    Xiao, Rong; Pang, Yue; Li, Qing Wei

    2012-05-01

    The parasitic phase lampreys (Lampetra japonica) are bloodsuckers in the marine, and their buccal gland secretion (lamphredin) contains various regulators such as anticoagulants, ion channel blockers, and immune suppressors like those from leeches, insects, ticks, vampire bats, and snakes. This review focuses on the functions and characteristics of the active proteins from the buccal gland of L. japonica for the first time, and provides new insights into the parasitic mechanisms of lampreys and the possibilities of developing drugs such as novel anticoagulants, thrombolytic agents, local anesthetics, and immunosuppressants. PMID:22586701

  9. Time-delay-induced phase-transition to synchrony in coupled bursting neurons

    NASA Astrophysics Data System (ADS)

    Adhikari, Bhim Mani; Prasad, Awadhesh; Dhamala, Mukeshwar

    2011-06-01

    Signal transmission time delays in a network of nonlinear oscillators are known to be responsible for a variety of interesting dynamic behaviors including phase-flip transitions leading to synchrony or out of synchrony. Here, we uncover that phase-flip transitions are general phenomena and can occur in a network of coupled bursting neurons with a variety of coupling types. The transitions are marked by nonlinear changes in both temporal and phase-space characteristics of the coupled system. We demonstrate these phase-transitions with Hindmarsh-Rose and Leech-Heart interneuron models and discuss the implications of these results in understanding collective dynamics of bursting neurons in the brain.

  10. 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

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

    PubMed

    Wong, Kam Lok; Wong, Ricky Ngok Shun; Zhang, Liang; Liu, Wing Keung; Ng, Tzi Bun; Shaw, Pang Chui; Kwok, Philip Chi Lip; Lai, Yau Ming; Zhang, Zhang Jin; Zhang, Yanbo; Tong, Yao; Cheung, Ho-Pan; Lu, Jia; Sze, Stephen Cho Wing

    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.

  12. 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

  13. Ectoparasites of Propithecus diadema (Primates: Indriidae) With Notes on Unusual Attachment Site Selection by Haemaphysalis lemuris (Parasitiformes: Ixodidae).

    PubMed

    Klompen, Hans; Junge, Randall E; Williams, Cathy V

    2015-05-01

    An examination of ectoparasite loads in two populations of wild diademed sifakas, Propithecus diadema Bennett, yielded seven species-four mite species, a louse, a hippoboscid fly, and a leech. Prevalence of the tick Haemaphysalis lemuris Hoogstraal, the mites Liponyssella madagascariensis (Hirst) and Lemuralges propithecus Bochkov et al., and the louse Trichophilopterus babakotophilus Stobbe was quite high, at least 20%. H. lemuris was the most common ectoparasite in one population, while completely absent in a second one. When present, the most common attachment site for H. lemuris males was in the nares of their hosts. PMID:26334804

  14. Mechanics of cocoon secretion in a segmented worm (Annelida: Hirudinidae).

    PubMed

    Rossi, Anthony M; Saidel, William M; Gravante, Christopher J; Sayers, Charlene W; Shain, Daniel H

    2016-07-01

    Clitellate annelids (e.g., segmented earthworms, leeches) secrete proteinaceous cocoons into which eggs are deposited. The process of cocoon production is characterized by the coordinated release of micro-granules from secretory cells positioned asymmetrically within the clitellum. Collectively, these assemble into a tubular cocoon sheath that is sealed at either end by globular opercula. By transmission electron microscopy (TEM), we show here that granules destined to the cocoon operculum in the leech, Erpodbdella obscura, display a series of concentric rings surrounding a structureless core with dimensions approximating a single nanoglobule found in the operculum. Upon their channeling to the surface through narrow tubules, granules are secreted into the cocoon lumen where they appear to fragment upon contact with the operculum matrix. The distribution of partial concentric ring structures throughout the operculum suggests that granular fusion causes dynamic fragmentation of outer surface material, which thereafter integrates into operculum nanoglobules and cavities. Other granules within the same secretory cell display a punctate pattern and likely fuse with the cocoon sheath prior to crystallization.

  15. Local-distributed integration by a novel neuron ensures rapid initiation of animal locomotion.

    PubMed

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

    2011-01-01

    Animals are adapted to respond quickly to threats in their environment. In many invertebrate and some vertebrate species, the evolutionary pressures have resulted in rapidly conducting giant axons, which allow short response times. Although neural circuits mediating escape behavior are identified in several species, little attention has been paid to this behavior in the medicinal leech, a model organism whose neuronal circuits are well known. We present data that suggest an alternative to giant axons for the rapid initiation of locomotion. A novel individual neuron, cell E21, appears to be one mediator of this short-latency action in the leech. In isolated nerve cord and semi-intact preparations, cell E21 excitation initiates and extends swimming and reduces the cycle period. The soma of this cell is located caudally, but its axon extends nearly the entire length of the nerve cord. We found that cell E21 fires impulses following local sensory inputs anywhere along the body and makes excitatory synapses onto the gating cells that drive swimming behavior. These distributed input-output sites minimize the distance information travels to initiate swimming behavior, thus minimizing the latency between sensory input and motor output. We propose that this single cell E21 functions to rapidly initiate or modulate locomotion through its distributed synaptic connections. PMID:20980540

  16. The pharmacology of extinction.

    PubMed

    Huxtable, R J

    1992-08-01

    It is impossible to predict what compounds of pharmacological interest may be present in an unexamined species. The extinction of such species may result, therefore, in the loss of therapeutically significant compounds. The fact that science will never know what has been lost does not lessen the significance of the loss. A number of species are discussed to exemplify the potential loss. Ginkgo biloba is an ancient plant, apparently saved from a natural extinction by human intervention. From this tree, the ginkgolides have been isolated. These are potent inhibitors of platelet activating factor and hold promise in the treatment of cerebral ischemia and brain edema. Two species, the tree Taxus brevifolia and the leech Hirudo medicinalis, are threatened as a result of human activity. Both have recently yielded complex compounds of therapeutic importance. The antitumor agent, taxol, is obtained from T. brevifolia and the thrombin inhibitor, hirudin, is found in H. medicinalis. Catharanthus roseus, source of the anticancer agents vincristine and vinblastine, although not threatened, derives from a largely unexamined but severely stressed ecosystem of some 5000 plant species. In other examples, ethnobotanical knowledge of certain plants may be lost while the species survive, as exemplified by the suppression of the Aztec ethnobotany of Mesoamerica by the invading Spanish. Finally, the fallacy of the 'snail darter syndrome', where species may be viewed as too insignificant to worry about, is exposed by consideration of the pharmacological activities of a sea hare (a shell-less marine mollusc) and various leeches.

  17. The life cycle of Australapatemon magnacetabulum (Digenea: Strigeidae) from Northwestern Argentina.

    PubMed

    Davies, Dora; de Núñez, Margarita Ostrowski

    2012-08-01

    The life cycle of Australapatemon magnacetabulum Dubois, 1988 was resolved experimentally. Planorbid snails Biomphalaria tenagophila (d'Orbigny, 1835) collected in a small pond at the confluence of the San Lorenzo and Arias Rivers, near Salta City, Province of Salta, Argentina, were found to be shedding furcocercous cercariae possessing 4 pairs of penetration glands, 1 pair of unpigmented eyespots, 6 pairs of flame cells in the body, and 1 pair in the tail stem. Metacercariae were found encysted in naturally, and experimentally, exposed leeches Helobdella adiastola Ringuelet, 1972, Helobdella triserialis (Blanchard, 1849), Haementeria eichhorniae Ringuelet 1978, and Haementeria sp., and within their sporocysts in naturally infected planorbid intermediate hosts. Sexually mature adults were recovered from domestic chicks and a duck 8-28 days postexposure by metacercariae from leeches. The identification of the species was based upon the characteristic large ventral sucker and a genital cone, crossed by a hermaphroditic duct with internal folds, occupying approximately a 1/4 to 1/5 of the hindbody. PMID:22475196

  18. 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.

  19. Macin Family of Antimicrobial Proteins Combines Antimicrobial and Nerve Repair Activities*

    PubMed Central

    Jung, Sascha; Sönnichsen, Frank D.; Hung, Chien-Wen; Tholey, Andreas; Boidin-Wichlacz, Céline; Haeusgen, Wiebke; Gelhaus, Christoph; Desel, Christine; Podschun, Rainer; Waetzig, Vicki; Tasiemski, Aurélie; Leippe, Matthias; Grötzinger, Joachim

    2012-01-01

    The tertiary structures of theromacin and neuromacin confirmed the macin protein family as a self-contained family of antimicrobial proteins within the superfamily of scorpion toxin-like proteins. The macins, which also comprise hydramacin-1, are antimicrobially active against Gram-positive and Gram-negative bacteria. Despite high sequence identity, the three proteins showed distinct differences with respect to their biological activity. Neuromacin exhibited a significantly stronger capacity to permeabilize the cytoplasmic membrane of Bacillus megaterium than theromacin and hydramacin-1. Accordingly, it is the only macin that displays pore-forming activity and that was potently active against Staphylococcus aureus. Moreover, neuromacin and hydramacin-1 led to an aggregation of bacterial cells that was not observed with theromacin. Analysis of the molecular surface properties of macins allowed confirmation of the barnacle model as the mechanistic model for the aggregation effect. Besides being antimicrobially active, neuromacin and theromacin, in contrast to hydramacin-1, were able to enhance the repair of leech nerves ex vivo. Notably, all three macins enhanced the viability of murine neuroblastoma cells, extending their functional characteristics. As neuromacin appears to be both a functional and structural chimera of hydramacin-1 and theromacin, the putative structural correlate responsible for the nerve repair capacity in leech was located to a cluster of six amino acid residues using the sequence similarity of surface-exposed regions. PMID:22396551

  20. Multiplexed modulation of behavioral choice

    PubMed Central

    Palmer, Chris R.; Barnett, Megan N.; Copado, Saul; Gardezy, Fred; Kristan, William B.

    2014-01-01

    Stimuli in the environment, as well as internal states, influence behavioral choice. Of course, animals are often exposed to multiple external and internal factors simultaneously, which makes the ultimate determinants of behavior quite complex. We observed the behavioral responses of European leeches, Hirudo verbana, as we varied one external factor (surrounding water depth) with either another external factor (location of tactile stimulation along the body) or an internal factor (body distention following feeding). Stimulus location proved to be the primary indicator of behavioral response. In general, anterior stimulation produced shortening behavior, midbody stimulation produced local bending, and posterior stimulation usually produced either swimming or crawling but sometimes a hybrid of the two. By producing a systematically measured map of behavioral responses to body stimulation, we found wide areas of overlap between behaviors. When we varied the surrounding water depth, this map changed significantly, and a new feature – rotation of the body along its long axis prior to swimming – appeared. We found additional interactions between water depth and time since last feeding. A large blood meal initially made the animals crawl more and swim less, an effect that was attenuated as water depth increased. The behavioral map returned to its pre-feeding form after approximately 3 weeks as the leeches digested their blood meal. In summary, we found multiplexed impacts on behavioral choice, with the map of responses to tactile stimulation modified by water depth, which itself modulated the impact that feeding had on the decision to swim or crawl. PMID:24902753

  1. [Parasites-invaders of the Volga river basin: history of invasion, perspective of dispersion, possibility of epizootic].

    PubMed

    Zhokhov, A E; Pugacheva, M N

    2001-01-01

    The fauna of fish parasites in the Volga river increased by 15 species in last time. These parasites have invaded together with introduced hosts or dispersed after destruction of some physical and ecological barriers. The infusoria Ambiphrya ameuri, cestode Cestobothrium acheilognathi, trematodes Amurotrema dombrovskajae and Sanguinicola skrabini have been introduced together with their hosts. A creation of water reservoirs destroyed ecological barriers and created favorable conditions for the migration and dispersion of parasites. The cestodes Eubothrium rugosum, Proteocephalus longicollis, and nematode Cystidicola farionis migrated from the North, Aspidogaster limacoides migrated from the South. The leech Caspiobdella fadejevi, trematodes Rossicotrema donicus, Apophallus muehlingi, Niccola skrjabini, Plagioporus skrjabini migrated through the Volga-Don channel. Some invader have already finished their dispersion in the water reservoirs of Volga river, other parasites still continue this process. South border of the E. rugosum range is in the Kujbyshev water basin, the leech C. fadejevi is distributed in all water basins, trematodes R. donicus, A. muehlingi and P. skrjabini are found in the Volga delta, while N. skrjabini has already reached the Saratov water basin. Perspectives of new invaders and epizootic significance of invaders is discussed.

  2. 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.

  3. Mechanics of cocoon secretion in a segmented worm (Annelida: Hirudinidae).

    PubMed

    Rossi, Anthony M; Saidel, William M; Gravante, Christopher J; Sayers, Charlene W; Shain, Daniel H

    2016-07-01

    Clitellate annelids (e.g., segmented earthworms, leeches) secrete proteinaceous cocoons into which eggs are deposited. The process of cocoon production is characterized by the coordinated release of micro-granules from secretory cells positioned asymmetrically within the clitellum. Collectively, these assemble into a tubular cocoon sheath that is sealed at either end by globular opercula. By transmission electron microscopy (TEM), we show here that granules destined to the cocoon operculum in the leech, Erpodbdella obscura, display a series of concentric rings surrounding a structureless core with dimensions approximating a single nanoglobule found in the operculum. Upon their channeling to the surface through narrow tubules, granules are secreted into the cocoon lumen where they appear to fragment upon contact with the operculum matrix. The distribution of partial concentric ring structures throughout the operculum suggests that granular fusion causes dynamic fragmentation of outer surface material, which thereafter integrates into operculum nanoglobules and cavities. Other granules within the same secretory cell display a punctate pattern and likely fuse with the cocoon sheath prior to crystallization. PMID:27129037

  4. Principal sources and dispersal patterns of suspended particulate matter in nearshore surface waters of the northeast Pacific Ocean and the Hawaiian Islands

    NASA Technical Reports Server (NTRS)

    Carlson, P. R. (Principal Investigator)

    1973-01-01

    The author has identified the following significant results. Numerous geologic features can be discerned on ERTS-1 imagery of the northwestern Olympic Peninsula, Washington, and southern Vancouver Island, British Columbia. A thick homoclinal sequence of north-dipping Tertiary marine strata along the northwestern Olympic Peninsula is readily discernible because of the banded nature of its outcrop. The submarine basalt on which the sequence rests shows as a high, rugged ridge. Within the sedimentary sequence, alternating sandstone and siltstone members 100 m or more thick show in the southeast corner of the image. Broad folds in this banded sequence and faults that cut it can be detected. One large fault, the Pysht River fault, and a large syncline in sandstone and siltstone east of it show prominently on the image. Numerous lineations on the image of southern Vancouver Island correlate with faults shown on Muller's map. Particularly prominent are the Leech River and San Juan faults along the southernmost part of the island.

  5. Redescription and molecular characterization of Placobdella cryptobranchii (Johnson & Klemm, 1977) (Glossiphoniidae, Hirudinida)

    PubMed Central

    Moser, William E.; Briggler, Jeffrey T.; Richardson, Dennis J.; Schuette, Chawna D.; Hammond, Charlotte I.; Hopkins, William A.; Lazo-Wasem, Eric A.

    2013-01-01

    Abstract Placobdella cryptobranchii (Johnson & Klemm, 1977) was originally described from specimens collected from Ozark Hellbenders (Cryptobranchus alleganiensis bishopi) from the North Fork of the White River in Missouri, U.S.A. Leeches collected during August 2009 to August 2011 from five localities in Missouri (including the type locality) facilitated a redescription and molecular characterization of Placobdella cryptobranchii. Placobdella cryptobranchii has a rusty, reddish-brown dorsum with 2 lateral rows of unpigmented papillae, two unpigmented nuchal bands, unpigmented patches, and pair of four pre-anal papillae. Molecular comparison of CO-I sequence data from Placobdella cryptobranchii revealed a 93–94% similarity to Placobdella ornata and 10–17% difference among other species of Placobdella. PMID:24146580

  6. 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. 

  7. 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.

  8. [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.

  9. Ceramic waste form production and development at ANL-West.

    SciTech Connect

    Battisti, T. J.; Goff, K. M.; Bateman, K. J.; Simpson, M. F.; Lind, J. P.

    2002-08-21

    Argonne National Laboratory has developed a method to stabilize spent electrolyte salt discarded from electrorefiners (ER) used to treat spent nuclear fuel. The salt is stabilized in a ceramic using a pressureless consolidation technique. The starting material is zeolite 4A which is used as the host for the fission product and actinide rich salt. Glass frit is added to the salt loaded zeolite before processing to act as a binder. The zeolite 4A is converted to sodalite during processing via pressureless consolidation. This process differs from one used in the past that employed a hot isostatic press. Ceramic is created at 925 C and atmospheric pressure instead of the high pressures used in hot isostatic pressing. Process flow sheets, off-gas test results, processing equipment, and leech test results are presented.

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

    SciTech Connect

    Tong, W.

    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 ({beta}TC3) 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.

  11. 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.

  12. Uktena riparia n. gen., n. sp. (Annelida, Clitellata, Lumbriculidae), a new spermatophore-producing oligochaete.

    PubMed

    Fend, Steven V; Rodriguez, Pilar; Lenat, David R

    2015-01-01

    Uktena riparia n. gen., n. sp. has been collected in hyporheic habitats at several sites in North Carolina, southeastern USA. The genus is defined by unusual characters related to reproductive structures, including the formation of encapsulated spermatophores for sperm transfer and large bundles of genital chaetae, both previously unknown in the Lumbriculidae. The simultaneous occurrence of both spermatophores and spermathecae is rare in the microdrile oligochaetes. Uktena spermatophores appear more similar to those reported in leeches than to those in other microdrile oligochaete families. Possible synapomorphies associating Uktena with the genera Kincaidiana and Guestphalinus include a filiform, ringed proboscis, a forward shift of reproductive organs relative to the usual position in the family, and spermathecae in the atrial segment. The new species adds to the already diverse, endemic lumbriculid fauna of the North Carolina Sandhills ecoregion. PMID:26250281

  13. Cytokine loaded biopolymers as a novel strategy to study stem cells during wound-healing processes.

    PubMed

    Grimaldi, Annalisa; Banfi, Serena; Vizioli, Jacopo; Tettamanti, Gianluca; Noonan, Douglas M; de Eguileor, Magda

    2011-08-11

    The biopolymer matrigel loaded with cytokine can be used for the recruitment in vivo of specific cell populations and as a vector for the preparation of cell cultures. Data demonstrate that the injection of the matrigel biopolymer supplemented with interleukin-8 (IL-8) in the leech Hirudo medicinalis can be used to purify cell populations showing the same morphofunctional and molecular mechanisms of specific populations of vertebrate hematopoietic precursor cells involved in tissue repair. These cells spontaneously differentiated into myofibroblasts. This approach highlights how the innovative use of a cytokine-loaded biopolymer for an in vivo cell sorting method, applied to a simple invertebrate model, can be a tool for studying myofibroblast cell biology and its regulation, step by step. PMID:21400659

  14. Specific MALDI-MSI: Tag-Mass.

    PubMed

    Stauber, Jonathan; Ayed, Mohamed El; Wisztorski, Maxence; Salzet, Michel; Fournier, Isabelle

    2010-01-01

    MALDI imaging as a molecular mass spectrometry imaging technique (MSI) can provide accurate information about molecular composition on a surface. The last decade of MSI development has brought the technology to clinical and biomedical applications as a complementary technique of MRI and other molecular imaging. Then, this IMS technique is used for endogenous and exogenous molecule detection in pharmaceutical and biomedical fields. However, some limitations still exist due to physical and chemical aspects, and sensitivity of certain compounds is very low. Thus, we developed a multiplex technique for fast detection of different compound natures. The multiplex MALDI imaging technique uses a photocleavable group that can be detect easily by MALDI instrument. These techniques of targeted imaging using Tag-Mass molecules allow the multiplex detection of compounds like antibodies or oligonucleotides. Here, we describe how we used this technique to detect huge proteins and mRNA by MALDI imaging in rat brain and in a model for regeneration; the leech. PMID:20680601

  15. Use of scanning ion conductance microscopy to guide and redirect neuronal growth cones.

    PubMed

    Pellegrino, Mario; Orsini, Paolo; De Gregorio, Francesca

    2009-07-01

    Scanning ion conductance microscopy has been applied to neuronal growth cones of the leech either to image or to stimulate them. Growth cone advance was recorded in non-contact mode using a 2% ion current decrease criterion for pipette-membrane distance control. We demonstrate effective growth cone remodelling using a 5% criterion (near-scanning). Recurrent line near-scanning aligned growth cone processes along the scan line. The new membrane protrusions, marked by DiI, started a few minutes after scanning onset and progressively grew in thickness. Using scanning patterns suitable for connecting distinct growth cones, new links were consistently developed. Although the underlying mechanism is still a matter for investigation, a mechanical perturbation produced by the moving probe appeared to induce the process formation. Thanks to its deterministic and interactive features, this novel approach to guiding growth cones is a promising way to develop networks of identified neurons as well as link them with artificial structures. PMID:19447298

  16. 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.

  17. 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.

  18. Long term changes in atmospheric N and S throughfall deposition and effects on soil solution chemistry in a Scots pine forest in the Netherlands.

    PubMed

    Boxman, Andries W; Peters, Roy C J H; Roelofs, Jan G M

    2008-12-01

    In a Scots pine forest the throughfall deposition and the chemical composition of the soil solution was monitored since 1984. (Inter)national legislation measures led to a reduction of the deposition of nitrogen and sulphur. The deposition of sulphur has decreased by approximately 65%. The total mineral-nitrogen deposition has decreased by ca. 25%, which is mainly due to a reduction in ammonium-N deposition (-40%), since nitrate-N deposition has increased (+50%). The nitrogen concentration in the upper mineral soil solution at 10 cm depth has decreased, leading to an improved nutritional balance, which may result in improved tree vitality. In the drainage water at 90 cm depth the fluxes of NO3(-) and SO4(2-) have decreased, resulting in a reduced leeching of accompanying base cations, thus preserving nutrients in the ecosystem. It may take still several years, however, before this will meet the prerequisite of a sustainable ecosystem.

  19. 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.

  20. Redescription and molecular characterization of Placobdella cryptobranchii (Johnson & Klemm, 1977) (Glossiphoniidae, Hirudinida).

    PubMed

    Moser, William E; Briggler, Jeffrey T; Richardson, Dennis J; Schuette, Chawna D; Hammond, Charlotte I; Hopkins, William A; Lazo-Wasem, Eric A

    2013-01-01

    Placobdella cryptobranchii (Johnson & Klemm, 1977) was originally described from specimens collected from Ozark Hellbenders (Cryptobranchus alleganiensis bishopi) from the North Fork of the White River in Missouri, U.S.A. Leeches collected during August 2009 to August 2011 from five localities in Missouri (including the type locality) facilitated a redescription and molecular characterization of Placobdella cryptobranchii. Placobdella cryptobranchii has a rusty, reddish-brown dorsum with 2 lateral rows of unpigmented papillae, two unpigmented nuchal bands, unpigmented patches, and pair of four pre-anal papillae. Molecular comparison of CO-I sequence data from Placobdella cryptobranchii revealed a 93-94% similarity to Placobdella ornata and 10-17% difference among other species of Placobdella. PMID:24146580

  1. 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. PMID:25043348

  2. Long term changes in atmospheric N and S throughfall deposition and effects on soil solution chemistry in a Scots pine forest in the Netherlands.

    PubMed

    Boxman, Andries W; Peters, Roy C J H; Roelofs, Jan G M

    2008-12-01

    In a Scots pine forest the throughfall deposition and the chemical composition of the soil solution was monitored since 1984. (Inter)national legislation measures led to a reduction of the deposition of nitrogen and sulphur. The deposition of sulphur has decreased by approximately 65%. The total mineral-nitrogen deposition has decreased by ca. 25%, which is mainly due to a reduction in ammonium-N deposition (-40%), since nitrate-N deposition has increased (+50%). The nitrogen concentration in the upper mineral soil solution at 10 cm depth has decreased, leading to an improved nutritional balance, which may result in improved tree vitality. In the drainage water at 90 cm depth the fluxes of NO3(-) and SO4(2-) have decreased, resulting in a reduced leeching of accompanying base cations, thus preserving nutrients in the ecosystem. It may take still several years, however, before this will meet the prerequisite of a sustainable ecosystem. PMID:18457906

  3. 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.

  4. 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.

  5. Neuronal Control of Swimming Behavior: Comparison of Vertebrate and Invertebrate Model Systems

    PubMed Central

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

    2010-01-01

    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 forty 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. PMID:21093529

  6. A new species Micrarctia kautti (Lepidoptera: Erebidae, Arctiinae) from West China.

    PubMed

    Saldaitis, Aidas; Pekarsky, Oleg

    2015-05-04

    A new tiger moth, Micrarctia kautti sp. n., from southwest China, Sichuan is described. A diagnostic comparison with Micrarctia trigona (Leech, 1899) is provided. During recent years the Chinese Arctiini have been intensively collected and explored (Dubatolov, 1996a; Dubatolov, 1996b; Dubatolov, 2003; Dubatolov, Kishida & Wu, 2005; Fang & Cao, 1984; Fang, 2000 and numerous other publications) so the discovery of a striking new species by Sergey Murzin in the Dafengding Mountains, Sichuan Province, was most unexpected. Institutional acronyms used are as follows: ASV = Aidas Saldaitis (Vilnius, Lithuania); KNE = Kari Nupponen (Espoo, Finland); PKT = Peter Kautt (Tübingen, Germany); RMB = Ramon Macià (Barselona, Spain); WIGJ = World Insect Gallery (Joniškis, Lithuania).

  7. A new Haemogregarina species of the alligator snapping turtle, Macrochelys temminckii (Testudines: Chelydridae), in Georgia and Florida that produces macromeronts in circulating erythrocytes.

    PubMed

    Telford, Sam R; Norton, Terry M; Moler, Paul E; Jensen, John B

    2009-02-01

    Haemogregarina macrochelysi n. sp. (Apicomplexa: Haemogregarinidae) of the alligator snapping turtle, Macrochelys temminckii, is characterized by slender, recurved gamonts 29-35 x 3-4.5 microm, in which the anterior limb comprises 48-54% of the total length. The gamont nucleus, 5-7.5 x 2-5 microm, is situated at approximately midbody of the gamont. Meronts typical of Haemogregarina occupying erythrocytes have 3-8 small, compact nuclei and are 13-17 x 4.5-9 microm. Erythrocytic meronts that contain larger, nearly square or rectangular nuclei become rounded, and then undergo 7 or more nuclear divisions, which produce very large, usually ovoid to rounded meronts that may contain up to 150 nuclei or more within the thinly stretched host erythrocyte membrane. In tissues of the Placobdella spp. leech vectors, merogony occurs directly from sporozoites, forming merozoites that presumably are infective for the turtle host. PMID:19245282

  8. 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.

  9. A new Haemogregarina species of the alligator snapping turtle, Macrochelys temminckii (Testudines: Chelydridae), in Georgia and Florida that produces macromeronts in circulating erythrocytes.

    PubMed

    Telford, Sam R; Norton, Terry M; Moler, Paul E; Jensen, John B

    2009-02-01

    Haemogregarina macrochelysi n. sp. (Apicomplexa: Haemogregarinidae) of the alligator snapping turtle, Macrochelys temminckii, is characterized by slender, recurved gamonts 29-35 x 3-4.5 microm, in which the anterior limb comprises 48-54% of the total length. The gamont nucleus, 5-7.5 x 2-5 microm, is situated at approximately midbody of the gamont. Meronts typical of Haemogregarina occupying erythrocytes have 3-8 small, compact nuclei and are 13-17 x 4.5-9 microm. Erythrocytic meronts that contain larger, nearly square or rectangular nuclei become rounded, and then undergo 7 or more nuclear divisions, which produce very large, usually ovoid to rounded meronts that may contain up to 150 nuclei or more within the thinly stretched host erythrocyte membrane. In tissues of the Placobdella spp. leech vectors, merogony occurs directly from sporozoites, forming merozoites that presumably are infective for the turtle host.

  10. Helminthes and insects: maladies or therapies.

    PubMed

    El-Tantawy, Nora L

    2015-02-01

    By definition, parasites cause harm to their hosts. But, considerable evidence from ancient traditional medicine has supported the theory of using parasites and their products in treating many diseases. Maggots have been used successfully to treat chronic, long-standing, infected wounds which failed to respond to conventional treatment by many beneficial effects on the wound including debridement, disinfection, and healing enhancement. Maggots are also applied in forensic medicine to estimate time between the death and discovery of a corpse and in entomotoxicology involving the potential use of insects as alternative samples for detecting drugs and toxins in death investigations. Leeches are segmented invertebrates, famous by their blood-feeding habits and used in phlebotomy to treat various ailments since ancient times. Leech therapy is experiencing resurgence nowadays in health care principally in plastic and reconstructive surgery. Earthworms provide a source of medicinally useful products with potential antimicrobial, antiviral, and anticancer properties. Lumbrokinases are a group of fibrinolytic enzymes isolated and purified from earthworms capable of degrading plasminogen-rich and plasminogen-free fibrin and so can be used to treat various conditions associated with thrombotic diseases. Helminth infection has been proved to have therapeutic effects in both animal and human clinical trials with promising evidence in treating many allergic diseases and can block the induction of or reduce the severity of some autoimmune disorders as Crohn's disease or ulcerative colitis. What is more, venomous arthropods such as scorpions, bees, wasps, spiders, ants, centipedes, snail, beetles, and caterpillars. The venoms and toxins from these arthropods provide a promising source of natural bioactive compounds which can be employed in the development of new drugs to treat diseases as cancer. The possibility of using these active molecules in biotechnological processes can

  11. 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.

  12. Losses of biota from American aquatic communities due to acid rain.

    PubMed

    Schindler, D W; Kasian, S E; Hesslein, R H

    1989-07-01

    Models based on chemical survey data and geochemical assumptions were calibrated for areas where rates of acidification are known, then used to predict the declines in alkalinity and pH of lakes in the eastern and midwestern U.S.A. These results were combined with known acid tolerances of different taxonomic groups to estimate the extent of damage caused by acid rain to biological assemblages.An average of over 50% of the species in some taxonomic groups have probably been eliminated from lakes in the Adirondacks, Poconos-Catskills and southern New England. Moderate damage to biotic communities was predicted for lakes in central New England, and north-central Wisconsin. Damage predicted in Maine, upper Michigan, northeastern Minnesota and the remainder of the upper Great Lakes region was slight. Crustaceans, molluscs, leeches and insects were among the most severely affected groups. Among fishes, species of minnows (Cyprindae) were depleted in the most heavily acidified regions, with some declines in salmonid and centrarchid species.Predicted damage to individual lakes in all areas was highly variable. In areas receiving highly acidic deposition, 100% of the species in acid-sensitive taxonomic groups were eliminated in some lakes, while damage to other lakes was predicted to be slight.Estimated damage varied from lake to lake within each subregion, based on chemical characteristics. The most heavily damaged lakes in the Adirondacks and Pocono-Catskills have probably lost all species of molluscs, leeches and crustaceans. On the other hand, lakes of the Midwest showed either slight increases or decreases in the richness of predicted biotic communities.The possible ranges of original sulfate concentrations in lakes and the proportion of sulfuric acid in precipitation that liberated base cations from catchments were confined to relatively narrow limits by the model.

  13. Identifying Crucial Parameter Correlations Maintaining Bursting Activity

    PubMed Central

    Doloc-Mihu, Anca; Calabrese, Ronald L.

    2014-01-01

    Recent experimental and computational studies suggest that linearly correlated sets of parameters (intrinsic and synaptic properties of neurons) allow central pattern-generating networks to produce and maintain their rhythmic activity regardless of changing internal and external conditions. To determine the role of correlated conductances in the robust maintenance of functional bursting activity, we used our existing database of half-center oscillator (HCO) model instances of the leech heartbeat CPG. From the database, we identified functional activity groups of burster (isolated neuron) and half-center oscillator model instances and realistic subgroups of each that showed burst characteristics (principally period and spike frequency) similar to the animal. To find linear correlations among the conductance parameters maintaining functional leech bursting activity, we applied Principal Component Analysis (PCA) to each of these four groups. PCA identified a set of three maximal conductances (leak current, Leak; a persistent K current, K2; and of a persistent Na+ current, P) that correlate linearly for the two groups of burster instances but not for the HCO groups. Visualizations of HCO instances in a reduced space suggested that there might be non-linear relationships between these parameters for these instances. Experimental studies have shown that period is a key attribute influenced by modulatory inputs and temperature variations in heart interneurons. Thus, we explored the sensitivity of period to changes in maximal conductances of Leak, K2, and P, and we found that for our realistic bursters the effect of these parameters on period could not be assessed because when varied individually bursting activity was not maintained. PMID:24945358

  14. Pop-cola acids and tooth erosion: an in vitro, in vivo, electron-microscopic, and clinical report.

    PubMed

    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.

  15. 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

  16. Progressive Extensional Exhumation of the Ultrahigh-Pressure Tso Morari Terrain, NW Indian Himalaya

    NASA Astrophysics Data System (ADS)

    Hodges, K.; Clark, R.; Monteleone, B.; Sachan, H.; Mukherjee, B. K.; Ahmad, T.

    2011-12-01

    The core of the Tso Morari dome in the Ladakh region of NW India (roughly 33 °10'N; 78°10'E) is one of only two known ultrahigh-pressure (UHP) terrains in the Himalayan-Tibetan orogenic system. The quartzofeldspathic Puga Orthogneiss from the structurally deepest portions of the terrain does not contain UHP mineralogy but surrounds dismembered lenses of mafic eclogite with accessory coesite, confirming that at least the eclogite lenses experienced UHP metamorphic conditions (Mukherjee et al., 2003, International Geology Review; Sachan et al., 2004, European Journal of Mineralogy). U-Pb zircon dates from the Puga orthogneiss (53.3 ± 0.7 Ma: Leech et al., 2007, International Geology Review) provide what appear to be the most precise available constraints on the age of UHP metamorphism at Tso Morari provided we presume that the UHP assemblages in the eclogite lenses developed at the same time as the 53.3 ± 0.7 Ma metamorphic zircon in the orthogneiss. However, other components of the zircon population studied by Leech and co-workers, as well as the results obtained using other thermochronometers and geochronometers (de Sigoyer et al., 2004, Tectonics), demonstrate that a series of lower pressure metamorphic events also affected the Tso Morari terrain between ca. 53 Ma and ca. 45 Ma, implying rapid decompression at elevated temperatures (ca. 800 - 350°C). Our 1:50000-scale geologic mapping at Tso Morari provides evidence that this exhumation was largely accommodated by two previously unrecognized low-angle ductile detachments that separate the terrain into three tectonostratigraphic units with distinctive metamorphic histories. The structurally lowest shear zone (Karla detachment) separates the Puga Orthogneiss from overlying lower amphibolite facies metasedimentary rocks of the Zoboshisha Unit, which contains no UHP assemblages. Structurally higher and demonstrably younger detachments separate the Zoboshisha Unit and the Puga Orthogneiss from greenschist to

  17. 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

  18. Optically transparent multi-suction electrode arrays

    PubMed Central

    Nagarah, John M.; Stowasser, Annette; Parker, Rell L.; Asari, Hiroki; Wagenaar, Daniel A.

    2015-01-01

    Multielectrode arrays (MEAs) allow for acquisition of multisite electrophysiological activity with submillisecond temporal resolution from neural preparations. The signal to noise ratio from such arrays has recently been improved by substrate perforations that allow negative pressure to be applied to the tissue; however, such arrays are not optically transparent, limiting their potential to be combined with optical-based technologies. We present here multi-suction electrode arrays (MSEAs) in quartz that yield a substantial increase in the detected number of units and in signal to noise ratio from mouse cortico-hippocampal slices and mouse retina explants. This enables the visualization of stronger cross correlations between the firing rates of the various sources. Additionally, the MSEA's transparency allows us to record voltage sensitive dye activity from a leech ganglion with single neuron resolution using widefield microscopy simultaneously with the electrode array recordings. The combination of enhanced electrical signals and compatibility with optical-based technologies should make the MSEA a valuable tool for investigating neuronal circuits. PMID:26539078

  19. 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

  20. Production of specific-molecular-weight hyaluronan by metabolically engineered Bacillus subtilis 168.

    PubMed

    Jin, Peng; Kang, Zhen; Yuan, Panhong; Du, Guocheng; Chen, Jian

    2016-05-01

    Low-molecular-weight hyaluronan (LMW-HA) has attracted much attention because of its many potential applications. Here, we efficiently produced specific LMW-HAs from sucrose in Bacillus subtilis. By coexpressing the identified committed genes (tuaD, gtaB, glmU, glmM, and glmS) and downregulating the glycolytic pathway, HA production was significantly increased from 1.01gL(-1) to 3.16gL(-1), with a molecular weight range of 1.40×10(6)-1.83×10(6)Da. When leech hyaluronidase was actively expressed after N-terminal engineering (1.62×10(6)UmL(-1)), the production of HA was substantially increased from 5.96gL(-1) to 19.38gL(-1). The level of hyaluronidase was rationally regulated with a ribosome-binding site engineering strategy, allowing the production of LMW-HAs with a molecular weight range of 2.20×10(3)-1.42×10(6)Da. Our results confirm that this strategy for the controllable expression of hyaluronidase, together with the optimization of the HA synthetic pathway, effectively produces specific LMW-HAs, and could also be used to produce other LMW polysaccharides. PMID:26851304

  1. 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. PMID:26354932

  2. 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.

  3. Production, purification and characterisation of recombinant Fahsin, a novel antistasin-type proteinase inhibitor.

    PubMed

    de Bruin, Eric C; Roem, Dorina; Bulder, Ingrid; Dieker, Miranda; Voerman, Gerard; Hack, C Erik

    2005-11-01

    Serine proteinases from inflammatory cells, including polymorphonuclear neutrophils, are involved in various inflammatory disorders, like pulmonary emphysema and rheumatoid arthritis. Inhibitors of these serine proteinases are potential drug candidates for the treatment of these disorders, since they prevent the unrestricted proteolysis. This study describes a novel specific antistasin-type inhibitor of neutrophil serine proteinases, we called Fahsin. This inhibitor was purified from the Nile leech Limnatis nilotica, sequenced and heterologously expressed using a synthetic gene in the methylotrophic yeast Pichia pastoris, yielding 0.5 g(-l) of the protein in the culture medium. Recombinant Fahsin was purified to homogeneity and characterised by N-terminal amino acid sequencing and mass spectrometry. Inhibition-kinetic analysis showed that recombinant Fahsin is a fast, tight-binding inhibitor of human neutrophil elastase with inhibition constant in the nanomolar range. Furthermore, recombinant Fahsin was, in contrast to various other neutrophil elastase inhibitors, insensitive to chemical oxidation and biological oxidation via myeloperoxidase-generated free oxygen radicals. Thus, Fahsin constitutes a novel member of a still expanding family of naturally occurring inhibitors of serine proteinases with potential therapeutic use for treatment of human diseases.

  4. Blood parasites of amphibians from Algonquin Park, Ontario.

    PubMed

    Barta, J R; Desser, S S

    1984-07-01

    During a 5 wk period beginning May 25, 1983, 329 amphibians, which included specimens of Rana catesbeiana Shaw, Rana clamitans Latreille, Rana septentrionalis Baird, Rana sylvatica LeConte, Hyla crucifer Wied, Bufo americanus Holbrook, and Plethodon cinereus Green, from Lake Sasajewun, Algonquin Park, Ontario, Canada were examined for blood parasites. The prevalences of species of Trypanosoma, Haemogregarina, Lankesterella, Babesiasoma, and Thrombocytozoons in these amphibians were determined. Two species of microfilaria (probably Foleyella spp.) and two intraerythrocytic forms, inclusions of an icosahedral cytoplasmic DNA virus (ICDV) and groups of rickettsial organisms, were also observed. The following are new host records: Trypanosoma ranarum (Lankester, 1871) in B. americanus; Trypanosoma ranarum (Lankester, 1871) in R. sylvatica; Trypanosoma pipientis Diamond, 1950, Babesiasoma stableri Schmittner and McGhee, 1961 and Thrombocytozoons ranarum Tchacarof, 1963 in R. septentrionalis. The aquatic frogs generally showed a much higher prevalence of infection with blood parasites than the terrestrial frogs, toads and salamanders, which is suggestive of an aquatic vector. The leech Batracobdella picta Verrill, 1872, which was found on many of the aquatic frogs, is the most likely vector in the study area. Also, an increasing prevalence of parasites was noted with increasing sizes (ages) of Rana clamitans and R. catesbeiana suggesting that longer exposure to water makes these species more likely to acquire blood parasites. The presence of Trypanosoma ranarum in B. americanus appeared to coincide with their attainment of sexual maturity. PMID:6492319

  5. 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.

  6. 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.

  7. 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)

  8. 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. PMID:15817228

  9. 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

    2015-07-01

    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.

  10. 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.

  11. 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.

  12. 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.

  13. Species-specific effects on the optical signals of voltage-sensitive dyes.

    PubMed

    Ross, W N; Reichardt, L F

    1979-08-01

    The absorption changes of two merocyanine dyes in response to membrane potential changes were measured on several neuronal preparations to see whether the dyes would be useful in recording from these cells. We were able to record large signals without averaging from barnacle and leech neurons. The greatest signal with WW375 was seen at 750 nm. Much smaller increases in transmitted light intensity were seen at all other wavelengths between 500 and 780 nm. In contrast, vertebrate neuronal preparations produced much smaller signals with an entirely different action spectrum. Essentially the same spectrum was seen in cells of the sympathetic ganglion of the bullfrog, Rana catesbiana, dissociated chick spinal cord neurons, or dissociated rat superior cervical ganglion neurons. In each case an action potential was accompanied by increases in transmitted light intensity between 500 and 600 nm and 730 and 780 nm, and decreases in intensity between 600 and 730 nm with the dye WW375, the best dye tested. Similar results were obtained with dye NK2367 on both vertebrate and invertebrate preparations, except that the spectral properties were shifted 30 nm towards the blue. Both dyes caused some photodynamic damage to the cultured neurons after a few minute's exposure to the illuminating light. Several analogues of these dyes were also tried, but did not produce larger signals. PMID:490629

  14. 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.

  15. 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.

  16. 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).

  17. Production of specific-molecular-weight hyaluronan by metabolically engineered Bacillus subtilis 168.

    PubMed

    Jin, Peng; Kang, Zhen; Yuan, Panhong; Du, Guocheng; Chen, Jian

    2016-05-01

    Low-molecular-weight hyaluronan (LMW-HA) has attracted much attention because of its many potential applications. Here, we efficiently produced specific LMW-HAs from sucrose in Bacillus subtilis. By coexpressing the identified committed genes (tuaD, gtaB, glmU, glmM, and glmS) and downregulating the glycolytic pathway, HA production was significantly increased from 1.01gL(-1) to 3.16gL(-1), with a molecular weight range of 1.40×10(6)-1.83×10(6)Da. When leech hyaluronidase was actively expressed after N-terminal engineering (1.62×10(6)UmL(-1)), the production of HA was substantially increased from 5.96gL(-1) to 19.38gL(-1). The level of hyaluronidase was rationally regulated with a ribosome-binding site engineering strategy, allowing the production of LMW-HAs with a molecular weight range of 2.20×10(3)-1.42×10(6)Da. Our results confirm that this strategy for the controllable expression of hyaluronidase, together with the optimization of the HA synthetic pathway, effectively produces specific LMW-HAs, and could also be used to produce other LMW polysaccharides.

  18. Protective barrier program: Test plan for plant community dynamics

    SciTech Connect

    Sackschewsky, M.R.; Chatters, J.C.; Link, S.O.; Brandt, C.A.

    1991-01-01

    The Westinghouse Hanford Company (Westinghouse Hanford) and Pacific Northwest Laboratory (PNL) are jointly developing protective barriers for the long term isolation of low-level radioactive defense waste for the US Department of Energy (DOE) at the Arid Sites. Protective barriers have been identified as an integral part of the overall final disposal strategy for low-level defense waste at the Arid Sites (DOE 1987). At present, the conceptual design of the Arid Site protective barrier is a multilayer structure that will minimize waster infiltration into and through the underlying waste, and will prevent intrusion into the waste by plant roots, animals, and humans. This multilayer system consists of a fine soil layer overlying a coarse sand and/or gravel geo-filter overlying a layer of large cobbles or basalt riprap. Plants contribute several crucial functions to the overall performance of the protective barrier.Through transpiration, plants are capable of removing considerably more moisture from a given volume of soil than the physical process of evaporation alone. This becomes especially important after periods of excessive precipitation when the possibility of saturation of the textural break and leeching to the buried waste is increased. Plants also function in significantly reducing the amount of wind and water erosion that would be expected to occur on the barrier surface. In addition to these physical functions, plants also influence other biotic effects on barrier performance.

  19. Comparing Precipitation and Soil Moisture Data in Quantifying the Yield Impact of Extremely Wet Planting Seasons for U.S. Maize and Soy

    NASA Astrophysics Data System (ADS)

    Urban, D.; Lobell, D. B.

    2013-12-01

    The current growing season began with extremely heavy rains in many parts of the U.S., significantly delaying maize planting in many fields and raising speculation over what year-end yields will be like. While 2013 has been exceptional in this regard, extreme precipitation over the major production regions of the country has been increasing over the last half century, and is likely to continue doing so under many climate change scenarios. While there exist many known reasons that extreme wetness during and around the sowing period can lead to yield losses - such as delayed planting, nitrogen leeching, anoxic soil conditions impeding nutrient uptake - the relationship between these factors and yields over broad spatial and temporal scales remains poorly quantified. We use downscaled historical precipitation data, as well as soil moisture data from the VIC model to assess the impact of extremely wet planting seasons after controlling for growing season conditions. We find that soil moisture, expressed as a fraction of the soil's holding capacity, better captures the effects of extremely wet years, and that yield losses at the county level due to extreme moisture can be on the order of 10%.

  20. [Bloodletting as medical therapy for 2500 years].

    PubMed

    Ulvik, R J

    1999-06-30

    Bloodletting has been part of the history of medicine for more than 2500 years. Up to the end of the Middle Ages, the rationale for bloodletting originated from the ancient greek humoral theory. The great scientific progress from the 16th century and onward, apparently did not weaken its position. Prominent physicians such as Andreas Vesalius (1514-64), William Harvey (1578-1657) and Thomas Sydenham (1624-89) defended bloodletting. In the beginning of the 19th century the use of leeches became the major technique of bloodletting in Europe. In Norway bloodletting was mentioned in royal decrees from the 13th century, and the method became popular in folk medicine. At the end of the 19th century bloodletting came at last to be regarded as ineffective for most of its traditional purposes, and its use declined rapidly. Today, however, bloodletting is being restored in modern medicine as the most effective method of treating the increasing frequent disorders caused by iron overload. PMID:10425902

  1. Common mechanics of mode switching in locomotion of limbless and legged animals.

    PubMed

    Kuroda, Shigeru; Kunita, Itsuki; Tanaka, Yoshimi; Ishiguro, Akio; Kobayashi, Ryo; Nakagaki, Toshiyuki

    2014-06-01

    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.

  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. PMID:12161969

  3. 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.

  4. 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

  5. Complete mitochondrial genome of Hirudo nipponia (Annelida, Hirudinea).

    PubMed

    Xu, Yunling; Nie, Jing; Hou, Junjie; Xiao, Ling; Lv, Pan

    2016-01-01

    The complete mitochondrial genome (14,414 bp) of the blood-feeding leech Hirudo nipponia, which was an important natural medicinal resource, was sequenced and characterized. The genome encodes 13 protein-coding genes, 2 rRNAs and 22 tRNAs. The content of A + T was 72.60% for H. nipponia (31.69% A, 40.91% T, 15.45% G and 11.95% C). All protein-coding genes started with ATN except for nad3 and nad5, which used GTG as start codon. Eight protein-coding genes stopped with termination codon TAA. Five protein-coding genes used incomplete stop codon TA or T. The A + T-rich region was located between tRNA-Arg and tRNA-His with a length of 83 bp. This is the first report about completely sequenced mitochondrial genome from the family Hirudinidae. The complete mitochondrial genomes of H. nipponia would be useful for the exploration of Hirudinea polygenetic relationships.

  6. Growth-inhibiting extracellular matrix proteins also inhibit electrical activity by reducing calcium and increasing potassium conductances.

    PubMed

    Vargas, J; De-Miguel, F F

    2009-01-23

    Inhibitionof neurite sprouting and electrical activity by extracellular matrix (ECM) glycoproteins was studied during neurite regeneration by using anterior pagoda (AP) neurons of the leech. Adult isolated neurons were plated in culture inside ganglion capsules, which among many ECM proteins, contain a group of inhibitory peanut lectin- (PNA) binding glycoproteins. These proteins inhibit neurite production and contribute to the formation of a bipolar outgrowth pattern by AP neurons. Addition of PNA lectin to the culture medium to block the inhibitory effects of ECM glycoproteins induced an increase of neurite sprouting, the loss of the bipolar pattern, and also an increase in the amplitude and duration of action potentials evoked by intracellular current injection. PNA lectin had independent effects on neurite sprouting and electrical activity, since there was no correlation between the total neurite length and the amplitude of the action potentials. Moreover, action potentials were increased by the presence of PNA lectin even in neurons that did not grow. The changes induced by PNA lectin on the active conductances underlying the action potentials were estimated by quantitative model simulations. We predict that the increases in the amplitude and duration of the action potential induced by PNA lectin were due to an increase in a calcium conductance and a reduction in the delayed rectifier potassium conductance. Our results suggest that inhibitory ECM glycoproteins may use independent signaling pathways to inhibit neurite sprouting and electrical activity. These proteins affect the action potential by changing the proportion of inward and outward active conductances. PMID:18976697

  7. 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.

  8. Diet of Chinese skink, Eumeces chinensis: is prey size important?

    PubMed

    Chen, Xiaolin; Jiang, Yong

    2006-06-01

    The diet of the skink, Eumeces chinensis (Lacertilia: Scincidae), in Xiamen (Amoy), China was examined using stomach analysis during April and May, and its selection of prey size was tested by feeding trials. Insects (primarily Coleoptera, Lepidoptera, and Orthoptera), gastropods and arachnids constituted most of the E. chinensis diet, but earthworms, leeches, crustaceans and fish were also consumed. In the field, male skinks ate more prey items that were 11-20 mm in length than other size classes. When presented with a choice of different-sized prey in the laboratory, male E. chinensis exhibited a strong preference for prey items 11-20 mm in length over other size classes. The relationship between prey size and handling time was exponential, indicating that there is an upper limit to the ability of E. chinensis to process prey. Mean energy intake for handling different-sized prey showed that selection of midsizeclass prey items would provide male E. chinensis with the most energy-efficient prey option. These results indicate that prey size selection in E. chinensis favors maximization of rates of energy intake, which is in agreement with optimal foraging theory. PMID:21395993

  9. 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. PMID:21627637

  10. Haemogregarine infections of three species of aquatic freshwater turtles from two sites in Costa Rica

    PubMed Central

    Rossow, John A.; Hernandez, Sonia M.; Sumner, Scarlett M.; Altman, Bridget R.; Crider, Caroline G.; Gammage, Mallory B.; Segal, Kristy M.; Yabsley, Michael J.

    2013-01-01

    Twenty-five black river turtles (Rhinoclemmys funerea) and eight white-lipped mud turtles (Kinosternon leucostomum) from Selva Verde, Costa Rica were examined for haemoparasites. Leeches identified as Placobdella multilineata were detected on individuals from both species. All turtles sampled were positive for intraerythrocytic haemogregarines (Apicomplexa:Adeleorina) and the average parasitemia of black river turtles (0.34% ± 0.07) was significantly higher compared to white-lipped mud turtles (0.05% ± 0.006). No correlation was found between parasitemia and relative body mass of either species or between black river turtles from the two habitats. In addition, one scorpion mud turtle (Kinosternon scorpioides) examined from La Pacifica, Costa Rica, was positive for haemogregarines (0.01% parasitemia). Interestingly, parasites of the scorpion mud turtle were significantly smaller than those from the other two species and did not displace the erythrocyte nucleus, whereas parasites from the other two species consistently displaced host cell nuclei and often distorted size and shape of erythrocytes. This is the first report of haemogregarines in turtles from Central America and of haemogregarines in K. leucostomum, K. scorpioides, and any Rhinoclemmys species. Additional studies are needed to better characterise and understand the ecology of these parasites. PMID:24533326

  11. Chinese Herbal Medicine for Aspirin Resistance: A Systematic Review of Randomized Controlled Trials

    PubMed Central

    Liu, Ai-ju; Li, Hui-qin; Li, Ji-huang; Wang, Yuan-yuan; Chen, Dong; Wang, Yan

    2014-01-01

    Aspirin resistance (AR) is a prevalent phenomenon and leads to significant clinical consequences, but the current evidence for effective interventional strategy is insufficient. The objective of this systematic review is thus to assess the efficacy and safety of Chinese herbal medicine (CHM) for AR. A systematical literature search was conducted in 6 databases until December 2012 to identify randomized controlled trials (RCTs) of CHM for AR. As a result, sixteen RCTs with a total of 1011 subjects were identified, suggesting that the interests of the medical profession and the public in the use of CHM for AR have grown considerably in the recent years. Tongxinluo capsule and Danshen-based prescriptions were the most frequently used herbal prescriptions, while danshen root, milkvetch root, Leech, and Rosewood were the most frequently used single herbs. Despite the apparent reported positive findings, it is premature to determine the efficacy and safety of CHM for the treatment of AR due to poor methodological quality and insufficient safety data. However, CHMs appeared to be well tolerated in all included studies. Thus, CHM as a promising candidate is worthy of improvement and development for further clinical AR trials. Large sample-size and well-designed rigorous RCTs are needed. PMID:24701247

  12. 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

  13. 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

  14. Neuroanatomical clues to peripheral locomotor control in small crustaceans (Artemia salina).

    PubMed

    Kane, E S

    1975-08-01

    Brine shrimp (Artemia salina) were prepared for light and electron microscopy at several stages. Immersion-fixed, rapid Golgi impregnations demonstrated two distinct neuronal types in thoracic appendages of mature, freely swimming Artemia. Isolated motor neurons had large cell somas and thick, radiating dendrites at the body wall-limb junction. A long, elaborate axon extended into the limb. Groups of a second type of neuron with smaller somas and very thin, radiating processes occurred in the distal limb near presumably tactile bristles. Thick axons from motor neurons were traced to terminals associated with limb muscle. Both muscle and axon were best seen with Nomarski optics. Motor axons possessed elongate, irregularly shaped boutons en passant and morphologically variable boutons terminaux; the latter included huge endings with knobbed projectiles arising from thick collaterals, or smaller, round boutons from thin collaterals. In addition, a thick unidentified axon coursed longitudinally within the central body wall, sending short collaterals peripherally. The elaborate peripheral neurons described in this Golgi study may be anatomical correlates for the extraordinary coordination of mature brine shrimp. Because Artemia movements resemble those of leech and decapods, which have been studied extensively electrophysiologically, the possibility of similarly elaborate peripheral structures supplementing central control of locomotion in those invertebrates should be considered.

  15. 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.

  16. 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.

  17. Serotonin release from the neuronal cell body and its long-lasting effects on the nervous system

    PubMed Central

    De-Miguel, Francisco F.; Leon-Pinzon, Carolina; Noguez, Paula; Mendez, Bruno

    2015-01-01

    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. PMID:26009775

  18. 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

  19. Responses to Conflicting Stimuli in a Simple Stimulus–Response Pathway

    PubMed Central

    Baljon, Pieter Laurens

    2015-01-01

    The “local bend response” of the medicinal leech (Hirudo verbana) is a stimulus–response pathway that enables the animal to bend away from a pressure stimulus applied anywhere along its body. The neuronal circuitry that supports this behavior has been well described, and its responses to individual stimuli are understood in quantitative detail. We probed the local bend system with pairs of electrical stimuli to sensory neurons that could not logically be interpreted as a single touch to the body wall and used multiple suction electrodes to record simultaneously the responses in large numbers of motor neurons. In all cases, responses lasted much longer than the stimuli that triggered them, implying the presence of some form of positive feedback loop to sustain the response. When stimuli were delivered simultaneously, the resulting motor neuron output could be described as an evenly weighted linear combination of the responses to the constituent stimuli. However, when stimuli were delivered sequentially, the second stimulus had greater impact on the motor neuron output, implying that the positive feedback in the system is not strong enough to render it immune to further input. PMID:25673834

  20. Promoting blood circulation for removing blood stasis therapy for acute intracerebral hemorrhage: a systematic review and meta-analysis

    PubMed Central

    Li, Hui-qin; Wei, Jing-jing; Xia, Wan; Li, Ji-huang; Liu, Ai-ju; Yin, Su-bing; Wang, Chen; Song, Liang; Wang, Yan; Zheng, Guo-qing; Fan, Ji-ping

    2015-01-01

    Aim: To conduct a systematic review and meta-analysis to assess the current evidence available regarding the promoting blood circulation and removing blood stasis (PBCRBS) therapy for Chinese patients with acute intracerebral hemorrhage (ICH). Methods: Six databases were searched from their inception to November 2013. The studies assessed in ≥4 domains with 'yes' were selected for detailed assessment and meta-analysis. The herbal compositions for PBCRBS therapy for acute ICH patients were also assessed. Results: From the 6 databases, 292 studies claimed randomized-controlled clinical trials (RCTs). Nine studies with 798 individuals were assessed in ≥4 domains with 'yes' by using the Cochrane RoB tool. Meta-analysis showed that PBCRBS monotherapy and adjuvant therapy for acute ICH could improve the neurological function deficit, reduce the volume of hematoma and perihematomal edema, and lower the mortality rate and dependency. Moreover, there were fewer adverse effects when compared with Western conventional medication controls. Xueshuantong Injection and Fufang Danshen Injection, Buyang Huanwu Decoction and Liangxue Tongyu formula, and three herbs (danshen root, sanqi and leech) were the most commonly used Chinese herbal patent injections, herbal prescriptions and single herbs, respectively. Conclusion: Despite the apparently positive findings, it is premature to conclude that there is sufficient efficacy and safety of PBCRBS for ICH because of the high clinical heterogeneity of the included studies and small number of trials in the meta-analysis. Further large sample-sizes and rigorously designed RCTs are needed. PMID:25960132

  1. 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. PMID:26636582

  2. Centrally patterned rhythmic activity integrated by a peripheral circuit linking multiple oscillators.

    PubMed

    Jellies, John; Kueh, Daniel

    2012-08-01

    The central pattern generator for heartbeat in the medicinal leech, Hirudo generates rhythmic activity conveyed by heart excitor motor neurons in segments 3-18 to coordinate the bilateral tubular hearts and side vessels. We focus on behavior and the influence of previously un-described peripheral nerve circuitry. Extracellular recordings from the valve junction (VJ) where afferent vessels join the heart tube were combined with optical recording of contractions. Action potential bursts at VJs occurred in advance of heart tube and afferent vessel contractions. Transections of nerves were performed to reduce the output of the central pattern generator reaching the heart tube. Muscle contractions persisted but with a less regular rhythm despite normal central pattern generator rhythmicity. With no connections between the central pattern generator and heart tube, a much slower rhythm became manifest. Heart excitor neuron recordings showed that peripheral activity might contribute to the disruption of centrally entrained contractions. In the model presented, peripheral activity would normally modify the activity actually reaching the muscle. We also propose that the fundamental efferent unit is not a single heart excitor neuron, but rather is a functionally defined unit of about three adjacent motor neurons and the peripheral assembly of coupled peripheral oscillators.

  3. Case report: successful use of hyperbaric oxygen therapy for a complete scalp degloving injury.

    PubMed

    Khandelwal, S; Wall, J; Kaide, C; Katz, G

    2008-01-01

    We report a case of a complete scalp degloving injury in a 43-year-old previously healthy, tobacco-using female whose hair was caught in a tractor power take-off causing an instantaneous total scalping injury. Microsurgical replantation was started 4 hours after injury with the surgical procedure lasting 4 hours. Only the superficial temporal arteries were reanastomosed with no venous anastomosis possible. Hyperbaric oxygen (HBO2) treatment at 2.5 atmospheres absolute (ATA) for 90 minutes was administered immediately after surgery due to duskiness of the flap. Further HBO2 treatments were administered twice daily for seven days and then once daily for 30 days. Additionally, leech therapy was used for the first ten postoperative days. The patient's right auricle and most of the left auricle were completely lost. Despite the tenuous vascular inflow and initially absent venous drainage, at 3 month follow-up there was reepithelialization of her scalp except for an area of granulation tissue in the occipitoparietal area. At one year follow-up the area of granulation tissue was reduced, but there was no detectable hair growth or nerve function. We propose that HBO2 may facilitate tissue survival in scalp degloving injuries in the face of incomplete surgical revascularization. PMID:19175199

  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. Anuran trypanosomes: phylogenetic evidence for new clades in Brazil.

    PubMed

    da S Ferreira, Juliana I G; da Costa, Andrea P; Ramirez, Diego; Roldan, Jairo A M; Saraiva, Danilo; da S Founier, Gislene F R; Sue, Ana; Zambelli, Erick R; Minervino, Antonio H H; Verdade, Vanessa K; Gennari, Solange M; Marcili, Arlei

    2015-05-01

    Trypanosomes of anurans and fish are grouped into the Aquatic Clade which includes species isolated from fish, amphibians, turtles and platypus, usually transmitted by leeches and phlebotomine sand flies. Trypanosomes from Brazilian frogs are grouped within the Aquatic Clade with other anuran trypanosome species, where there seems to be coevolutionary patterns with vertebrate hosts and association to Brazilian biomes (Atlantic Forest, Pantanal and Amazonia Rainforest). We characterised the anuran trypanosomes from two different areas of the Cerrado biome and examined their phylogenetic relationships based on the SSU rRNA gene. A total of 112 anurans of six species was analysed and trypanosome prevalence evaluated through haemoculture was found to be 7% (8 positive frogs). However, only three isolates (2.7%) from two anuran species were recovered and cryopreserved. Analysis including SSU rDNA sequences from previous studies segregated the anuran trypanosomes into six groups, the previously reported An01 to An04, and An05 and An06 reported herein. Clade An05 comprises the isolates from Leptodactylus latrans (Steffen) and Pristimantis sp. captured in the Cerrado biome and Trypanosoma chattoni Mathis & Leger, 1911. The inclusion of new isolates in the phylogenetic analyses provided evidence for a new group (An06) of parasites from phlebotomine hosts. Our results indicate that the diversity of trypanosome species is underestimated since studies conducted in Brazil and other regions of the world are still few. PMID:25862033

  6. 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

  7. 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.

  8. Amino acid sequences of lysozymes newly purified from invertebrates imply wide distribution of a novel class in the lysozyme family.

    PubMed

    Ito, Y; Yoshikawa, A; Hotani, T; Fukuda, S; Sugimura, K; Imoto, T

    1999-01-01

    Lysozymes were purified from three invertebrates: a marine bivalve, a marine conch, and an earthworm. The purified lysozymes all showed a similar molecular weight of 13 kDa on SDS/PAGE. Their N-terminal sequences up to the 33rd residue determined here were apparently homologous among them; in addition, they had a homology with a partial sequence of a starfish lysozyme which had been reported before. The complete sequence of the bivalve lysozyme was determined by peptide mapping and subsequent sequence analysis. This was composed of 123 amino acids including as many as 14 cysteine residues and did not show a clear homology with the known types of lysozymes. However, the homology search of this protein on the protein or nucleic acid database revealed two homologous proteins. One of them was a gene product, CELF22 A3.6 of C. elegans, which was a functionally unknown protein. The other was an isopeptidase of a medicinal leech, named destabilase. Thus, a new type of lysozyme found in at least four species across the three classes of the invertebrates demonstrates a novel class of protein/lysozyme family in invertebrates. The bivalve lysozyme, first characterized here, showed extremely high protein stability and hen lysozyme-like enzymatic features.

  9. 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

  10. 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.

  11. 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. PMID:15831107

  12. Parasitization by Sauroplasma sp. (Apicomplexa: Haemohormidiidae) in Chelonian Podocnemis expansa (Testudines: Podocnemididae) in the Brazilian Amazon.

    PubMed

    Picelli, Amanda M; Carvalho, Aluísio V; Viana, Lúcio A; Malvasio, Adriana

    2016-02-01

    The prevalence and parasitemia of the piroplasm Sauroplasma sp. were evaluated in the Amazon chelonian Podocnemis expansa in Brazil. Samples were collected from 75 chelonians from 3 locations, including a commercial breeding facility, an indigenous subsistence breeding facility, and a wild population. Sauroplasma were found in 72% (54/75) of the chelonians, and the prevalence varied among the sampling sites. No significant correlations were found between the prevalence and the sex and body condition index of the chelonians. The mean parasitemia rate was 44.14/2,000 erythrocytes (2.2%), and no significant correlation was found between the parasitemia and sex and body condition index of the chelonians. These results suggest that the parasite is not pathogenic to P. expansa. No ectoparasites were found in the animals evaluated in the present study; however, due to the aquatic habit of the chelonian, it is likely that the piroplasm is transmitted by leeches and not by ticks, as would be expected for piroplasms. PMID:26561340

  13. 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. PMID:24476992

  14. 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. PMID:19640225

  15. [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. PMID:26875294

  16. Estimation of neuronal activity based on voltage-sensitive dye imaging in a moving preparation.

    PubMed

    Fathiazar, Elham; Kretzberg, Jutta

    2015-01-01

    Voltage-sensitive dye imaging allows simultaneous recording of graded voltage changes of multiple neurons. While this experimental technique is a great tool to study neuronal network activity in neuroscience, the optical recording suffers from artifacts. In particular, bleaching of the dye and cell movement impede the analysis and interpretation of imaging results. In this paper, we present methods to tackle these two main artifacts. Cell movement during the experiment is corrected by an optical flow method. Bleaching decay is estimated based on a line fit of recordings without stimulus, which is subtracted from the rest of the recordings in the same experiment. Here, we use a leech ganglion as an example tissue to evaluate these processing procedures. This preparation allows simultaneous voltage-sensitive dye imaging of the entire neuronal network and intracellular recording of one cell's membrane voltage. Using the intracellularly recorded voltage as the ground truth reference, we show that our processing methods for the VSD imaging signal clearly improve the correlation between the real and the estimated voltage. Since other imaging techniques (e.g., calcium imaging) suffer from the same type of artifacts as voltage-sensitive dye imaging, our processing method might be useful for a wide range of biomedical imaging studies. PMID:26737729

  17. 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

  18. Amino acid sequences of lysozymes newly purified from invertebrates imply wide distribution of a novel class in the lysozyme family.

    PubMed

    Ito, Y; Yoshikawa, A; Hotani, T; Fukuda, S; Sugimura, K; Imoto, T

    1999-01-01

    Lysozymes were purified from three invertebrates: a marine bivalve, a marine conch, and an earthworm. The purified lysozymes all showed a similar molecular weight of 13 kDa on SDS/PAGE. Their N-terminal sequences up to the 33rd residue determined here were apparently homologous among them; in addition, they had a homology with a partial sequence of a starfish lysozyme which had been reported before. The complete sequence of the bivalve lysozyme was determined by peptide mapping and subsequent sequence analysis. This was composed of 123 amino acids including as many as 14 cysteine residues and did not show a clear homology with the known types of lysozymes. However, the homology search of this protein on the protein or nucleic acid database revealed two homologous proteins. One of them was a gene product, CELF22 A3.6 of C. elegans, which was a functionally unknown protein. The other was an isopeptidase of a medicinal leech, named destabilase. Thus, a new type of lysozyme found in at least four species across the three classes of the invertebrates demonstrates a novel class of protein/lysozyme family in invertebrates. The bivalve lysozyme, first characterized here, showed extremely high protein stability and hen lysozyme-like enzymatic features. PMID:9914527

  19. 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. PMID:2023331

  20. The evolution and comparative neurobiology of endocannabinoid signalling.

    PubMed

    Elphick, Maurice R

    2012-12-01

    CB(1)- and CB(2)-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 CB(1)-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. CB(1)/CB(2)-type receptors originated in a common ancestor of extant chordates, and in the sea squirt Ciona intestinalis a CB(1)/CB(2)-type receptor is targeted to axons, indicative of an ancient role for cannabinoid receptors as axonal regulators of neuronal signalling. Although CB(1)/CB(2)-type receptors are unique to chordates, enzymes involved in biosynthesis/inactivation of endocannabinoids occur throughout the animal kingdom. Accordingly, non-CB(1)/CB(2)-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.

  1. Mechanisms underlying rhythmic locomotion: body–fluid interaction in undulatory swimming

    PubMed Central

    Chen, J.; Friesen, W. O.; Iwasaki, T.

    2011-01-01

    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. PMID:21270304

  2. Analysis, optimization and verification of Illumina-generated 16S rRNA gene amplicon surveys.

    PubMed

    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

  3. Transparent magnetic photoresists for bioanalytical applications.

    PubMed

    Gach, Philip C; Sims, Christopher E; Allbritton, Nancy L

    2010-11-01

    Microfabricated devices possessing magnetic properties are of great utility in bioanalytical microdevices due to their controlled manipulation with external magnets. Current methods for creating magnetic microdevices yield a low-transparency material preventing light microscopy-based inspection of biological specimens on the structures. Uniformly transparent magnetic photoresists were developed for microdevices that require high transparency as well as consistent magnetism across the structure. Colloidal formation of 10 nm maghemite particles was minimized during addition to the negative photoresists SU-8 and 1002F through organic capping of the nanoparticles and utilization of solvent-based dispersion techniques. Photoresists with maghemite concentrations of 0.01-1% had a high transparency due to the even dispersal of maghemite nanoparticles within the polymer as observed with transmission electron microscopy (TEM). These magnetic photoresists were used to fabricate microstructures with aspect ratios up to 4:1 and a resolution of 3 μm. Various cell lines showed excellent adhesion and viability on the magnetic photoresists. An inspection of cells cultured on the magnetic photoresists with TEM showed cellular uptake of magnetic nanoparticles leeched from the photoresists. Cellular contamination by magnetic nanoparticles was eliminated by capping the magnetic photoresist surface with native 1002F photoresist or by removing the top layer of the magnetic photoresist through surface roughening. The utility of these magnetic photoresists was demonstrated by sorting single cells (HeLa, RBL and 3T3 cells) cultured on arrays of releasable magnetic micropallets. 100% of magnetic micropallets with attached cells were collected following release from the array. 85-92% of the collected cells expanded into colonies. The polymeric magnetic materials should find wide use in the fabrication of microstructures for bioanalytical technologies. PMID:20719380

  4. 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.

  5. Mercury in the biotic compartments of Northwest Patagonia lakes, Argentina.

    PubMed

    Rizzo, A; Arcagni, M; Arribére, M A; Bubach, D; Guevara, S Ribeiro

    2011-06-01

    We report on total mercury (THg) concentrations in the principal components of food webs of selected Northern Patagonia Andean Range ultraoligotrophic lakes, Argentina. The THg contents were determined using Instrumental Neutron Activation Analysis in muscle and liver of four fish species occupying the higher trophic positions (the introduced Salmo trutta, Oncorhynchus mykiss and Salvelinus fontinalis, and the native Percichthys trucha) accounted for eight lakes belonging to Nahuel Huapi and Los Alerces National Parks. We studied the food web components of both the West and East branches of Lake Moreno, including benthic primary producers such as biofilm, mosses, and macrophytes, three plankton fractions, fish, riparian tree leaves, and benthic invertebrates, namely decapods, molluscs, insect larvae, leeches, oligochaetes, and amphipods. Mercury concentrations in fish muscle varied in a wide range, from less than 0.05 to 4 μg g(-1) dry weight (DW), without a distribution pattern among species but showing higher values for P. trucha and S. fontinalis, particularly in Lake Moreno. The THg contents of the food web components of Lake Moreno varied within 4 orders of magnitude, with the lower values ranging from 0.01 to 0.5 μg g(-1) DW in tree leaves, some macrophytes, juvenile salmonids or benthic macroinvertebrates, and reaching concentrations over 200 μg g(-1) DW in the plankton. Juvenile Galaxias maculatus caught in the pelagic area presented the highest THg contents of all fish sampled, reaching 10 μg g(-1) DW, contents that could be associated with the high THg concentrations in plankton since it is their main food source. Although Lake Moreno is a system without local point sources of contamination, situated in a protected area, some benthic organisms presented high THg contents when compared with those from polluted ecosystems.

  6. Global carbon burial in lakes, reservoirs and ponds; an alternative approach

    NASA Astrophysics Data System (ADS)

    Boyle, John; Hoffmann, Thomas

    2013-04-01

    It is widely stated that approximately 0.6 Pg of carbon are annually sequestered by lake, reservoir and pond sediments. The study from which this figure arises, Tranvik et al (2009), accepts: previously published values for natural lakes (0.03 to 0.07 Pg), rather higher than previously thought values for reservoirs (0.4 Pg C yr-1, based on 400,000 km2 at 1000 g C m-2, up from 0.16-0.20 Pg previously estimated), and and a previously omitted large contribution from "small eutrophic impoundments" (0.15 Pg yr-1, based on 75,000 km2 at 2000 g C m-2). As these estimates depend heavily on C burial data from 25 artificial water bodies in Iowa, we have undertaken a wider analysis to assess their global applicability. Reference: Tranvik, L.J., Downing, J.A., Cotner, J.B., Loiselle, S.A., Striegl, R.G., Ballatore, T.J., Dillon, P., Finlay, K., Fortino, K., Knoll, L.B., Kortelainen, P.L., Kutser, T., Larsen, S., Laurion, I., Leech, D.M., McCallister, S.L., McKnight, D.M., Melack, J.M., Overholt, E., Porter, J.A., Prairie, Y., Renwick, W.H., Roland, F., Sherman, B.S., Schindler, D.W., Sobek, S., Tremblay, A., Vanni, M.J., Verschoor, A.M., von Wachenfeldt, E. and Weyhenmeyer, G.A., 2009. Lakes and reservoirs as regulators of carbon cycling and climate. Limnology and Oceanography, 54(6): 2298-2314.

  7. 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.

  8. On the Basis of Synaptic Integration Constancy during Growth of a Neuronal Circuit.

    PubMed

    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 (r dend), 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. Analysis of Family Structures Reveals Robustness or Sensitivity of Bursting Activity to Parameter Variations in a Half-Center Oscillator (HCO) Model.

    PubMed

    Doloc-Mihu, Anca; Calabrese, Ronald L

    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.

  10. 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.

  11. 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

  12. 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

  13. Lasting changes in a network of interneurons after synapse regeneration and delayed recovery of sensitization.

    PubMed

    Urazaev, A K; Arganda, S; Muller, K J; Sahley, C L

    2007-12-19

    Regeneration of neuronal circuits cannot be successful without restoration of full function, including recovery of behavioral plasticity, which we have found is delayed after regeneration of specific synapses. Experiments were designed to measure neuronal changes that may underlie recovery of function. Sensitization of the leech withdrawal reflex is a non-associative form of learning that depends on the S-interneuron. Cutting an S-cell axon in Faivre's nerve disrupted the capacity for sensitization. The S-cell axon regenerated its electrical synapse with its homologous cell after 3-4 weeks, but the capacity for sensitization was delayed for an additional 2-3 weeks. In the present experiments another form of non-associative conditioning, dishabituation, was also eliminated by S-cell axotomy; it returned following regeneration. Semi-intact preparations were made for behavioral studies, and chains of ganglia with some skin were used for intracellular recording and skin stimulation. In both preparations there was a similar time-course, during 6 weeks, of a lesion-induced decrease and delayed restoration of both S-cell action potential threshold to depolarizing pulses and S-cell firing in response to test stimuli. However, the ability of sensitizing stimuli to decrease S-cell threshold and enhance S-cell activity in response to test stimuli did not fully return after regeneration, indicating that there were lasting changes in the circuit extending beyond the period necessary for full recovery of behavior. Intracellular recordings from the axotomized S-cell revealed a shift in the usual balance of excitatory and inhibitory input, with inhibition enhanced. These results indicate that loss of behavioral plasticity of reflexive shortening following axotomy in the S-cell chain may be related to reduced S-cell activity, and that additional processes underlie full recovery of sensitization of the whole body shortening reflex. PMID:18031937

  14. 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

  15. 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

  16. 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.

  17. 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.

  18. 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.

  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. PMID:9718743

  20. Influence of therapeutic radiation on polycaprolactone and polyurethane biomaterials.

    PubMed

    Cooke, Shelley L; Whittington, Abby R

    2016-03-01

    Biomedical polymers are exposed in vivo to ionizing radiation as implants, coatings and bystander materials. High levels of ionizing radiation (e.g. X-ray and gamma) have been reported to cause degradation and/or cross-linking in many polymers. This pilot study sought to determine causes of failure, by investigating how therapeutic radiation affects two different porous polymeric scaffolds: polycaprolactone (PCL) and polyurethane (PU). PCL is a bioresorbable material used in biomedical devices (e.g., dentistry, internal fixation devices and targeted drug delivery capsules). PU is commonly used in medical applications (e.g., coatings for pacemakers, tissue expanders, catheter tubing and wound dressings). PU was specifically fabricated to be a non-degradable polymer in this study. Porous scaffolds, fabricated using solvent casting and/or salt leeching techniques, were placed in phosphate buffered saline (PBS, pH=7.4) and exposed to typical cancer radiotherapy. A total dose of 50 Gy was broken into 25 doses over an eleven-week period. Collected PBS was tested for polymer leachants and degradation products using Gas Chromatography Mass Spectroscopy (GC-MS), results revealed no analyzable leachants from either polymer. Scaffolds were characterized using Environmental Scanning Electron Microscopy, Size-exclusion chromatography (SEC), Differential Scanning Calorimetry (DSC) and Fourier Transform Infrared Spectroscopy (FTIR). No gross visual changes were observed in either polymer, however PU exhibited microstructure changes after irradiation. Increased number average molecular weight and weight average molecular weight in PCL and PU were observed after irradiation, indicating crosslinking. PU displayed an increase in intrinsic viscosity that further confirms increased crosslinking. PCL and PU showed decreases in crystallinity after irradiation, and PU crystallinity shifted from long-range-order hard segments to short-range-order hard segments after irradiation. Results