Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “LEECHES”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4Linked to original sources
PubMed2002

Model for intersegmental coordination of leech swimming: central and sensory mechanisms.

Sensory feedback as well as the coupling signals within the CNS are essential for leeches to produce intersegmental phase relationships in body movements appropriate for swimming behavior. To study the interactions between the central pattern generator (CPG) and peripheral feedback in controlling intersegmental coordination, we have constructed a computational model for the leech swimming system with physiologically realistic parameters. First, the leech swimming CPG is simulated by a chain of phase oscillators coupled by three channels of coordinating signals. The activity phase, the projection direction, and the phase response curve (PRC) of each channel are based on the identified intersegmental interneuron network. Output of this largely constrained model produces stable coordination in the simulated CPG with average phase lags of 8-10 degrees/segment in the period range from 0.5 to 1.5 s, similar to those observed in isolated nerve cords. The model also replicates the experimental finding that shorter chains of leech nerve cords have larger phase lags per segment. Sensory inputs, represented by stretch receptors, were subsequently incorporated into the CPG model. Each stretch receptor with its associated PRC, which was defined to mimic the experimental results of phase-dependent phase shifts of the central oscillator by the ventral stretch receptor, can alter the phase of the local central oscillator. Finally, mechanical interactions between the muscles from neighboring segments were simulated by PRCs linking adjacent stretch receptors. This model shows that interactions between neighboring muscles could globally increase the phase lags to the larger value required for the one-wavelength body form observed in freely swimming leeches. The full model also replicates the experimental observation that leeches with severed nerve cords have larger intersegmental phase lags than intact animals. The similarities between physiological and simulation results demonstrate that we have established a realistic model for the central and peripheral control of intersegmental coordination of leech swimming.

Animals↗
PubMed1999

The medicinal leech in Jewish writings.

Leeches were widely used for healing throughout antiquity and the Middle Ages. The rabbinic responsa literature acknowledges the use of leeching for the prevention and treatment of certain illnesses, and classic Jewish sources including the Bible, Talmud, and Codes of Jewish Law describe leeches and mention their medicinal use. Although the swallowing of a leech is considered dangerous and may lead to abdominal swelling, the Talmud describes an oral concoction containing leeches in wine for patients with enlarged spleens. It is also documented that engorged leeches placed in salt quickly discharge their blood and can be used again. Modern plastic and microsurgery have rediscovered the medicinal leech, Hirudo medicinalis, to reduce venous congestion. Clearly, the value of this annelid worm lies in its secretion of an anticoagulant known as hirudin, which has several advantages over heparin. One cannot help but marvel at the wisdom and ingenuity of our forefathers.

Animals↗
PubMed2006

Delayed leech-borne infection with Aeromonas hydrophilia in escharotic flap wound.

Medicinal leeches (Hirudo medicinalis) are commonly used in plastic surgery for the salvage of congested flaps and replanted parts compromised by venous congestion. Infection associated with leech therapy is a documented complication of leech application, with reported incidences ranging from 2.4 to 20% [De Chalain TM. Exploring the use of the medicinal leech: a clinical risk-benefit analysis. J Reconstr Microsurg 1996;12(3):165-72.1]. We describe a case of delayed leech-borne infection, from the escharotic portion of a latissimus dorsi flap, which developed several days after stopping leech therapy for venous congestion in a reconstructed breast.

Aeromonas↗
PubMed2004

Salvage of partial facial soft tissue avulsions with medicinal leeches.

BACKGROUND: Medicinal leeches have been demonstrated to be extremely useful and safe in the salvage of venous outflow compromised tissue, particularly in digit replants and various forms of flaps. OBJECTIVE: To demonstrate the utility of medicinal leeches in the salvage of venous outflow-compromised traumatic soft tissue avulsions in key facial structures. METHODS: A retrospective review of 4 cases involving the external ear, nose, lip, and scalp in which apparent venous outflow compromise was present. Medicinal leeches were applied acutely in each of these 4 cases, salvaging each of the partially avulsed soft tissue segments. RESULTS: Complete or near complete salvage of each soft tissue segment after using medicinal leeches. CONCLUSIONS: 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. This is particularly important in vital structures such as the ear, nose, lip, and eyelid in which acute or secondary reconstruction is complex. EBM RATING: C.

Animals↗
PubMed2002

Nosocomial Infections with Aeromonas hydrophila from Leeches.

The manner in which leeches are maintained before they are used for therapy has not been studied as a factor contributing to nosocomial infections. A 5-year retrospective survey of Aeromonas hydrophila nosocomial infections at a hospital in Marseille, France, revealed infections in 5 (4.1%) of an estimated 122 patients treated with leeches in the Hand Surgery Unit and 2 (2.4%) of an estimated 85 patients treated with leeches in other hospital units. The retrospective survey showed that the Hand Surgery Unit was the only unit that had its own aquarium for maintaining leeches; this aquarium was filled with tap water contaminated with Aeromonas species and was not regularly disinfected or cleaned. Leeches used in other units were maintained in noncarbonated water in a transport device. Use of leeches kept in aquariums that are filled with tap water and not disinfected or cleaned regularly may be linked to A. hydrophila infections.

Aeromonas hydrophila↗
PubMed2002

Leech therapy for patients with surgically unsalvageable venous obstruction after revascularized free tissue transfer.

OBJECTIVE: To assess the efficacy and associated complications of a leech therapy protocol used for patients with a head and neck free tissue transfer in whom flap viability is threatened because of surgically unsalvageable venous obstruction. DESIGN: Medical record review of a prospective protocol. SETTING: Tertiary care academic medical center. PATIENTS: Of the 450 free tissue transfers to the head and neck region performed by our microvascular program from January 1, 1995, to October 31, 2000, 8 patients (1.8%) developed venous obstruction not considered salvageable by conventional surgical or thrombolytic therapy. INTERVENTIONS: All 8 patients were placed on a protocol using leeches (Hirudo medicinalis), intensive care unit monitoring, antithrombotic pharmacotherapy, frequent hematologic evaluation, blood transfusions as needed, and antibiotic prophylaxis for Aeromonas hydrophila. MAIN OUTCOME MEASURES: Flap salvage rate, number of leeches used per patient, time needed for inosculation, duration of intensive care unit admission, transfusion requirement per patient, and complications during leech therapy. RESULTS: All 8 flaps survived with the application of this protocol. An average of 215 leeches were used per patient, and the average time needed for inosculation was 6.6 days. The average duration in the intensive care unit was 9.6 days. The morbidity of our protocol was substantial, with intensive care unit psychosis, prerenal azotemia, and large transfusion requirements being the most frequent complications. An average of 13 U of packed red blood cells per patient was necessary. CONCLUSIONS: Aggressive application of the presented leech therapy protocol can salvage free tissue transfers with venous obstruction that are otherwise unsalvageable. The associated morbidity can be marked. Thus, judicious application of this protocol for flap preservation is essential.

Aged↗
PubMed1995

Distribution and developmental expression of octopamine-immunoreactive neurons in the central nervous system of the leech.

Octopamine, a biogenic amine analogous to norepinephrine, plays an important role in the orchestration and modulation of invertebrate behavior. In the leech, the behavioral actions of octopamine have been demonstrated; however, identification of octopaminergic neurons had not been determined by using immunohistochemical techniques. Thus, we used an antibody highly specific to octopamine to examine the distribution of octopamine-immunoreactive neurons in the segmental ganglia of American and European medicinal leeches (Macrobdella decora and Hirudo medicinalis). One pair of octopamine-immunoreactive neurons was located in the dorsolateral ganglionic region of anterior ganglia 1-6 and posterior ganglia 15-21. No corresponding octopamine-immunoreactive neurons were found in midbody ganglia 7-14. Using Neutral Red staining in combination with intracellular Neurobiotin injections and octopamine immunostaining, we determined the identity of the dorsolateral octopamine-immunoreactive cells. The dorsolateral octopamine-immunoreactive neuron (the DLO) was not cell 21, the only previously reported Neutral Red staining neuron in the dorsolateral position. We also determined that the Leydig neuron was not octopamine immunoreactive in either of the two medicinal leech species. Octopamine immunostaining in the sex ganglia revealed hundreds of immunoreactive neurons in sexually mature leeches. Such neurons were not observed in juvenile leeches. The developmental time course of octopamine immunoreactivity in the dorsolateral octopamine-immunoreactive neurons was also investigated by staining embryonic Hirudo medicinalis. Octopamine expression occurred relatively late as compared with the detectable onset of serotonin expression. Octopamine expression in the dorsolateral octopamine-immunoreactive cells was not detectable at early to mid-embryonic stages, and must commence during late embryonic to early juvenile stages. The identification of octopamine-immunoreactive cells now sets the stage for further investigations into the functional role of octopamine in leech behavior and the development of behavior.

Animals↗
PubMed1995

Regionalization and segmentation of the leech.

Regionalization and segmentation of the leech body plan have been examined by numerous approaches over the years. A wealth of knowledge has accumulated regarding the normally invariant cell lineages of the leech and the degree of developmental plasticity that is possible in each cell line in early development and in neurogenesis. Homologues of genes that control regionalization and segmentation in Drosophila have been cloned from the leech and the expression patterns reveal conserved features with those in Drosophila and other organisms. Possible developmental functions of the en-class proteins in spatial and temporal modes of segment formation are discussed in light of leech and Drosophila development. Annelida and Arthropoda cell lineages of engrailed-class gene expression are compared in leech blast cell clones and crustacean parasegments. In addition, future directions for molecular analysis of segmentation of the leech are summarized.

Animals↗
PubMed2004

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

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.

Animals↗
PubMed2005

Rickettsia infection in natural leech populations.

Field-collected specimens of glossiphoniid leeches, Torix tagoi, Torix tukubana, Hemiclepsis marginata, and Hemiclepsis japonica, were surveyed for Rickettsia infection by using a diagnostic PCR assay. Rickettsia was detected in 96% (69/72) of T. tagoi, 83% (24/29) of T. tukubana, 29% (33/113) of H. marginata, and 0% (0/30) of H. japonica. The frequencies of Rickettsia infection were stably maintained in different seasons. In H. marginata and T. tukubana, distant local populations exhibited remarkably different frequencies of Rickettsia infection. Eggs carried by infected females of T. tagoi and H. marginata were all Rickettsia-positive, indicating nearly 100% vertical transmission. Analysis of 16S rDNA sequences revealed that phylogenetic relationship of the leech-associated Rickettsia reflected the specific and populational divisions of the host leeches. However, circumstantial lines of evidence strongly suggested that horizontal transmission of Rickettsia must have occurred in the ancestors of these leeches. In T. tagoi and T. tukubana, infected individuals were remarkably larger in size than uninfected individuals, wheras in H. marginata, infected and uninfected individuals were almost comparable in size. This study first provides information on ecological aspects of leech-bone endocellular bacteria of the genus Rickettsia. On the basis of these data, we discuss possible mechanisms whereby Rickettsia infection is maintained in natural populations of these leeches in the freshwater ecosystem.

Animals↗
PubMed2004

Aquatic leech infestation: a rare cause of severe anaemia in an adolescent Tanzanian girl.

UNLABELLED: We report on a 15-year-old girl who presented with a history of chest pain, coughing, intermittent haemoptysis, fever, pallor and vomiting to a rural hospital in Tanzania. She was severely anaemic with signs of cardiorespiratory distress. Haemoglobin was 4.8 g/dl; the chest X-ray film was normal. She required one unit of blood. After 3 days, she vomited up a small parasite which proved to be an aquatic leech. Oesophagogastroscopy, then performed, revealed four small mucosal lesions in the pharynx and upper oesophagus. No other leeches were seen. Further oesophagogastroscopy 4 days later showed a normal mucosa. The girl was discharged on iron and folic acid supplements. A small lake near her village was identified as the likely source of her infestation. The family had used the water for drinking without any precautions-Terrestrial leeches can cause profound, life-threatening anaemia, but even more so do aquatic leeches. This type is acquired while bathing or drinking unfiltered water. They attach themselves to mucous membranes, having been described in sites like conjunctiva, nose, pharynx/larynx, trachea/bronchi, oesophagus, vagina, and rectum. Especially in the airways, they can cause even fatal bleeding or obstruction. Treatment consists of removal of the leech. CONCLUSION: In developing countries, even unusual causes like leech infestation have to be considered in the differential diagnosis of severe anaemia in children.

Adolescent↗
PubMed2001

Distribution and partial characterization of CREB-like immunoreactivity in the medicinal leech Hirudo.

The presence and distribution of immunoreactivity to the cyclic AMP response element binding protein (CREB) were determined in the central nervous system (CNS) and in peripheral tissues of the medicinal leech Hirudo. Western blots revealed several CREB-immunoreactive (CREB-IR) bands including one whose molecular weight (43-44 kDa) was similar to mammalian CREB. The 43-44 kDa CREB-like protein was detected in nuclear extracts of the ventral nerve cord and was not observed following preincubation of the primary antiserum with the epitope sequence. CREB-like immunoreactivity was detected in extracts from each of six regions of the leech CNS, and in extracts from leech body wall musculature, crop, intestine, jaw musculature, pharynx, and salivary tissues. Whole mounts of leech ganglia revealed specific CREB-IR in a restricted population of neurons distributed throughout the leech CNS. Apparent homologues to a pair of CREB-IR dorsolateral neurons were observed in most ganglia along the ventral nerve cord. Several CREB-IR neurons exhibited segmental specificity. A number of neurons stained with an antiserum to the cyclic AMP response element modulator (CREM). These neurons showed no overlap in location with CREB-IR neurons, and this staining was not eliminated with a preabsorption control. Possible roles for a CREB-like protein in the leech are discussed.

Animals↗
PubMed2001

Elements of angiotensin system are involved in leeches and mollusks immune response modulation.

We present immunocytochemical, biochemical and cellular evidences for the presence of a renin-angiotensin system (RAS) in coelomocytes of invertebrates (leech, Theromyzon tessulatum and mollusk Mytilus edulis). Leech coelomocytes are immunoreactive to polyclonal antisera raised against the T. tessulatum angiotensin-converting enzyme (ACE) and leech brain angiotensin II (AII) and a commercial anti-AT1 receptor. Biochemically, renin, ACE- and AT1-like receptor were identified in the leech immune cells. We further demonstrate that leech AII (10(-6) M) alone does not initiate nitric oxide (NO) release in invertebrate immunocytes but does only after pre-exposing the cells to IL-1 (15.9+/-2.6 nM; P<0.005 vs. 1.1 nM when AII is added alone). Similar results were obtained with human leukocytes (14.5+/-2.7 nM; P<0.005 IL-1+AII vs. 0.9 nM when AII is added alone). Then, an immunocytochemical study performed at the structural and ultrastructural levels confirmed the presence in same immune cells all the molecules of the renin-angiotensin system (RAS) in leeches as epitopes to IL-1-like protein and IL-1-like receptor. This is the first report in invertebrates and of a co-action between cytokines like substances and neuropeptides in an immune process and the involvement of the RAS in modulation of the immune response.

Angiotensins↗
PubMed2000

PLGamide characterization and role in osmoregulation in leech brain.

Neurons immunoreactive to an antiserum specifically directed against the Prolyl-Leucyl-Glycinamide peptide (PLGamide: Melanocyte Inhibiting Factor: MIF) were detected in the brain of the leech Theromyzon tessulatum. Radioimmunoassay titrations of the PLGamide-like material at different physiological stages of the life cycle indicated a maximal amount at stage 3B, which is correlated to phase of both maximal water uptake and coelomic vitellogenin accumulation. In vivo experiments demonstrate that this cerebral PLGamide-like material is an anti-diuretic factor that would act at stage 3B in order to permit a water uptake leading to water retention allowing coelomic yolk protein accumulation. In brains of the Gnatobdellid leech Hirudo medicinalis and the Pharyngobdellid leech Erpobdella octoculata, anti-PLGamide material was also detected with an amount not differing with the degree of sex maturation of the animals, confirming the link between osmoregulation and ovogenesis in rhynchobdellid leeches. Using a combination of biochemical techniques including high-pressure gel permeation chromatography followed by reversed-phase HPLC on brain extracts and Edman degradation, we demonstrated the presence of an authentic MIF-1 peptide in leech brain. Finally, since in vertebrates MIF-1 belongs to the non-classical opioid peptide family, we studied its binding displacement, in contrast to morphine, on mu-receptors and on nitric oxide (NO) release experiments in leech brain. PLGamide did not bind to mu-alkaloid opioid receptors and did not stimulate NO release.

Animals↗
PubMed2004

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

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.

Egypt↗
PubMed1994

Carbohydrate-binding proteins in the leech: I. Isolation and characterization of lactose-binding proteins.

Three lactose-binding proteins with apparent molecular masses of 16, 35, and 63 kDa [leech lectin 16, 35, and 63 (LL,16, LL35, and LL63, respectively)] were isolated from leech membranes. Polyclonal antibodies raised against LL35 cross-reacted with LL16 and LL63, indicating that all three lectins were immunologically related. These leech lectins, however, can be subdivided into two groups based on their tissue distributions and binding affinities for galactose derivatives. LL16 and LL35 are endogenous to the leech's CNS, whereas LL63 is only present in peripheral organs. LL16 and LL35, found in the CNS, bind both the alpha and beta anomers of methylgalactose, whereas the peripheral lectin LL63 binds only the beta form. LL35 and LL63 also differ in their binding affinities for galactosamine and N-acetylgalactosamine. The binding activity of LL35 was calcium independent and active over a wide pH range. Triton X-100 and 2-mercaptoethanol were necessary to recover LL35 binding activity during extraction. These characteristics strongly suggest that LL35 is another member of the calcium-independent galactose/lactose-specific lectins previously described in vertebrates and recently demonstrated in sponges and nematodes. Because a single leech expresses up to 100 micrograms of LL35, this leech lectin is readily amenable to structural and functional analysis.

Animals↗
PubMed1995

Mechanical leech therapy to relieve venous congestion.

When faced with venous insufficiency following replantation or free-tissue transfer, the surgeons' first choice is surgical repair. When repair is not possible, medicinal leeches may be applied to relieve congestion. However, leeches increase the possibility of infection through their gut contents, and there are times when the available leech supply is short and the need for rapid exsanguination is great. A mechanical device has been developed and tested which could be used as a substitute for the medicinal leech. Using a venous-congested rat epigastric flap, this device was demonstrated to be superior to a medicinal leech in restoring capillary perfusion to the flap during the first hour of exsanguination. The device may offer an alternative to the medicinal leech for the clinical treatment of small areas of tissue with venous congestion.

Animals↗
PubMed1990

Leech therapy and bleeding wound techniques to relieve venous congestion.

Temporary restoration of capillary skin blood flow can be established by using leeches or by the creation of a dermal wound and the promotion of continued bleeding from the wound site in a flap with venous occlusion. An increasing restoration of capillary flow occurred with initial application of the leech and tended to exceed other techniques of restoring flow. However, all techniques of exsanguination, including leech therapy, restored very low perfusion over a two-hour course of therapy for a volume of tissue simulating a distal finger replant. The temporary increase in flap perfusion with a single leech application was greatest during the feeding activity of the leech and tapered off after the leech was satiated, to approximate flows achieved with local heparin injection and a punch wound.

Animals↗