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Extracellular application of amtysol decreased the amplitude and increased the duration of evoked APs, not affecting the form of spontaneous APs in the leech Retzius' neurons. Besides, a disorder in the habituation process occurred which only normally develops during a high-frequency synaptic activation of the neurons.
The salivary gland secretion of the medicinal leech catalyzes the conversion into monomeric form of the fragment D dimer, the product of limited proteolysis of stabilized fibrin. Analysis of N-terminal sequences revealed identical fragments for the D-dimer gamma-gamma-chains and the D-monomer gamma-chains formed via this reaction and established the presence of only one N-terminal amino acid (Ser). These results provide evidence for the preservation of integrity of the polypeptide chains during monomerization of the D-dimer.
Using single-electrode voltage clamp, heart interneurons of the medicinal leech were shown to possess both a rapidly inactivating outward current, IA, and a more slowly inactivating outward current, IK. IA and IK could be separated by their voltage sensitivity and kinetic properties. FMRF-NH2 (Phe-Met-Arg-Phe-NH2) modulates IK by shifting both steady state activation and inactivation to more hyperpolarized potentials, but it does not affect the time constants. IA and IK appear to use K+ as a charge carrier; a change in the external [K+] produced a shift in the apparent reversal potential in the direction predicted with potassium as the charge carrier. Both IA and IK are sensitive to tetraethylammonium (TEA) and 4-aminopyridine (4-AP), and TEA and 4-AP both interfere with the effects of FMRF-NH2 on IK. The biophysical properties of IA and of IK in the presence and absence of FMRF-NH2 were incorporated into a Hodgkin-Huxley model of these currents that could reproduce voltage-clamp data. FMRF-NH2 produces two apparently dissimilar effects on the heartbeat rhythm--acceleration and disruption. We suggest that both effects could result from the hyperpolarizing shifts in steady state activation and inactivation of IK.
Experiences of pediatric ICU nurses as they cared for a child requiring leech therapy are described in this article along with the clinical conditions and therapy of the case. The nurses' ambivalence about participating in what seemed to be an archaic therapy and how they had to put such feelings aside to support the family are explained.
We demonstrate the presence in leech hemolymph of high levels of a peptide recognized by antiserum directed against bovine chromacin. The purification of the chromacin-like peptide was carried out by an acidic extraction, followed by solid phase and high pressure gel permeation chromatography and reversed-phase HPLC purification. Its sequence (GDFELPSIADPQATFESQRGPSAQQVDK) was established by a combination of techniques, including automated Edman degradation, MALDI-TOF measurement and DOT immunobinding assays with anti-chromogranin A. Mass spectrometry measurement revealed a m/z 3177Da, revealing the fact that the molecule is phosphorylated. ELISA titrations performed at each step of the purification revealed a major increase in the level of the peptide (ca. 125 nmol/microl of coelomic fluid) 15 min after LPS exposure. The increase in chromacin-like peptide levels is both time and concentration dependent. The level of this peptide decreased significantly 4 hours after LPS exposure. This report is the first discovery of a chromogranin derived like peptide in invertebrates.
AIMS: Testing the effectiveness of a topical combination preparation containing standardized leech extract, polidocanol and allantoin. STUDY DESIGN: Placebo-controlled, double-blind study in 80 patients with first and second degree hemorrhoids; duration of treatment one week; examinations performed on admission and on days 3, 4, 5 and 8. RESULTS: Both the subjective and objective symptoms and signs improved during the one week of treatment statistically significantly more rapidly under the test preparation as compared with placebo. Histologically demonstrable signs of inflammation were more clearly improved in the preparation group than in the placebo group. No side effects were observed. CONCLUSIONS: The good efficacy and tolerability of a topical therapeutic preparation in first and second degree hemorrhoids have been convincingly demonstrated.
Histological analysis of frontal section through the body of parasitic leeches (Codonobdella truncata, Caspiobdella fadejewi) of the subfamily Piscicolinae revealed the presence of 11 pairs of subepidermal pulsatile vesicles. The vesicles of C. truncata are poorly visible on the body surface, contrary to those of C. fadejewi, which results from the fact that in the former species the vesicles are located in a layer of subepidermal connective tissue thicker (82. 82 microm) than in C. fadejewi (20.6 microm). In the studied species the pulsatile vesicles have a club-like shape, are surronded by a muscular tunicle and connected with a short canal that penetrates the body wall. Some of the sections show that the vesicles are divided in two chambers (lower and upper) with an incomplete membrane.
Piscicola brylinskae n. sp. is described from the lake Vechten in the village of Bunnik (Prov. Utrecht), The Netherlands. The characteristic features of this leeches allow to conclude that this species is a member of the subfamily Piscicolinae, probably a parasite of fish.
The article starts with a brief review of the use and abuse of Hirudo medicinalis. For a long time the word leech was a common name in England for the worm and for a physician, and possibly had its origin in the very old Indo-European stem leg, which is probably also the stem of our Scandinavian terms laege/lege/läkare. It is commonly known, however, that lege and other similar words used for physicians in Europe, both today and in former times, are of Celtic origin. This arouses one's curiosity. With the help of a wellknown American colleague and a Czech physician with a special knowledge of languages, I traced the source of these words back to the great Indo-European family of languages. All the traces pointed to leg-the stem with numerous ramifications in many old and modern languages. From the beginning, leg seemed to be associated with knowledge and wisdom. Tempted by this finding, I followed traces of history, as indicated in words referring specially to physicians in the different European languages. In this article I discuss the significance of the Celtic language in this connection, since in former times it was one of the main branches of the Indo-European family of languages. The old Greek word logos, with its corresponding verb legein containing the same implication as mentioned above, is also said to have some connection with our profession.
The authors analyze the laboratory and instrumental data obtained before and after single administration of leeches. Demonstrate that the animal's saliva corrects the coagulation properties of the circulating blood; inhibits platelet aggregation; that it may be used for blood letting; possesses hypotensive and anti-sclerotic properties; improves myocardial supply and its contractility. Based on a large clinical material the authors provide evidence for advisability of the use of hirudotherapy in patients suffering from coronary heart disease, essential hypertension, atherosclerosis, chronic cer pulmonale, and circulatory decompensation.
Synaptic transmission between reciprocally inhibitory heart interneurons (HN cells) of the medicinal leech was examined in the absence of Na-mediated action potentials. Under voltage clamp, depolarizing steps from a holding potential of -60 mV elicited 2 kinetically distinct components of inward current in the presynaptic HN cell: an early transient current that inactivates within 200 msec and a persistent current that only partially decays over several seconds. Both currents begin to activate near -60 mV. Steady-state inactivation occurs over the voltage range between -70 and -45 mV and is completely removed by 1-2-sec hyperpolarizing voltage steps to -80 mV. The inward currents are carried by Ca2+, Ba2+, or Sr2+ ions, but not by Co2+, Mn2+, or Ni2+. These same inward currents underlie the burst-generating plateau potentials previously described in HN cells (Arbas and Calabrese, 1987a,b). With a presynaptic holding potential of -60 mV, the threshold for transmitter release is near -45 mV. Postsynaptic currents in the contralateral HN cell have a reversal potential near -60 mV. The largest postsynaptic currents (300-400 pA) exhibit an initial peak response that is followed by a more slowly decaying component. The persistent component of Ca2+ current in the presynaptic neuron is strongly correlated with the prolonged component of the postsynaptic current, while the transient presynaptic Ca2+ current appears to correspond to the early peak of postsynaptic current. These data are consistent with the hypothesis that voltage-dependent calcium currents contribute to the oscillatory capability of reciprocally inhibitory HN cells by (1) generating the plateau potential that drives the burst of action potentials and (2) underlying the release of inhibitory transmitter onto the contralateral cell.
In the present contribution the distributive pattern of phosphatases and non-specific esterase amongst the constituents of the leech eye has been revealed and the significance of the enzymatic locales in relation to the visual processes has been discussed. All the phosphatases studied demonstrate absence of the activity in the lens. Activity of the phosphatases, however, is restricted to the plasma membrane and associated cytoplasm to varying degrees. The significance of the phosphatases in the nerve impulses and transmission has been highlightened. The observation of considerable significance relates the demonstration of a high degree of non-specific esterase activity in the lens, which has defied all the phosphatases. Another observation relates to the positive activity of 5-nucleotidase in the group of axons constituting optic nerve. The significance of this observation has also been discussed.
The molecular mass of destabilase isolated from the medicinae leech Hirudo medicinalis was found to be equal to 12.3 kDa. A kinetic analysis of the sole presently known synthetic substrate, L-gamma-Glu-pNA, showed that the enzyme is relatively stable to heating (5 min, 70 degrees C); the pH optimum lies at 7.0-8.5. The enzyme has a specific activity of 0.15 x 10(-9) mol.s-1.mg-1; Km = 2.2 x 10(-4) M, kcat is 3.53 x 10(-3) s-1 (pH 8.0, 37 degrees C).
Leeches have had a long association with human beings and in recent years have proved valuable in biomedical research and surgery. Veterinary surgeons should be concerned with these creatures because of their role in causing disease, because of the part they may play in controlling the numbers of other invertebrates, because of their potential in veterinary therapy and because of the need to manage them properly in captivity.
Axons of lateral nociceptive (N) neurons in leech segmental ganglia wrap certain somata in adjacent ganglia but no somata in their own ganglion. In adults, the N neurons, which accurately regenerate axosomatic wrappings, can be induced to sprout in their own ganglion and wrap target homologues if the ganglion is isolated by cutting the nerve cord. Manipulations that denervate the new targets without injuring the lateral N cell, including focal lesions and protease injections into other N cells, also cause sprouting within 2-4 months. In contrast, cutting the lateral N cell's axons causes little or no sprouting within the ganglion without denervation. Therefore, denervation rather than injury accounts for sprouting within the ganglion. It is concluded that lateral N cells can wrap somata in their own ganglion that are homologues of their usual targets, but they are prevented from doing so by axonal wrappings from N cells in adjacent ganglia.
Five proteins with anticoagulant and antimetastatic activities were isolated from the salivary glands of the Amazon leech, Haementeria ghilianil. These proteins, designated ghilantens, were co-purified on DEAE-cellulose and heparin-agarose, and were purified by microbore C-18 reverse-phase HPLC. Each variant had a similar molecular weight (18,000), amino acid composition, and a blocked amino terminus. Ghilantens caused a dose-dependent prolongation of the prothrombin time of normal human plasma and blocked the factor Xa-mediated hydrolysis of methoxycarbonyl-D-cyclohexylglycyl-glycl-arginine-p-nitro anillide acetate. Ghilantens were quantitatively absorbed to bovine factor Xa-AffiGel-15 and were eluted with 0.1 mol/L benzamidine, an active-site reversible inhibitor of factor Xa. These findings show that ghilantens can form a reversible association with the enzyme. When administered intravenously to mice by tall vein injection, ghilantens potently suppressed lung metastases of B16-F10 melanoma cells. These findings suggest that ghilantens may have therapeutic value in the treatment of metastatic disease.
Sensory processing in the local bending reflex of the leech (Hirudo medicinalis) was studied by examining the input-output relations of the reflex. Sensory cells (P cells) were stimulated singly and in pairs and the responses of the longitudinal muscle motor neurons were recorded. Each pattern of single and paired P cell stimulation produced a unique pattern of motor neuron response. In general, motor neuron response patterns were consistent with the behavioral response of the whole animal.
Isolated midbody ganglia of the leech Hirudo medicinalis were surveyed for interneurons contributing to the dorsal component of the local bending reflex, i.e., to the excitation of dorsal excitatory motor neurons that follows stimulation of dorsal mechanoreceptors responsive to pressure (P cells). Nine types of local bending interneuron could be distinguished on physiological and morphological grounds--8 paired and 1 unpaired cell per ganglion. Synaptic latencies from sensory neurons to interneurons were consistent with a direct or possibly disynaptic pathway. Connections between interneurons appeared to be rare and hyperpolarization of individual interneurons during local bending produced small but reliable decrements in motor neuron response, suggesting that multiple parallel pathways contribute to the behavior. Paradoxically, most interneurons received substantial inputs from ventral as well as dorsal mechanoreceptors, indicating that interneurons that were distinguished by their contribution to dorsal local bending were, in fact, active in ventral and lateral bends as well. The capacity to detect a particular stimulus and produce the appropriate response cannot be localized to particular types of interneuron; rather, it appears to be a distributed property of the entire local bending network.