'Pearls' of the nineteenth-century: from therapeutic actors to global commodities medicinal leeches in the Ottoman Empire.

Nineteenth-century physicians increasingly favoured leeching - the placing of a live leech onto a patient's skin to stimulate or limit blood flow - as a cure for numerous ailments. As conviction in their therapeutic properties spread, leech therapy dominated European medicine; France imported over fifty million leeches in one year. Demand soon outpaced supply, spawning a lucrative global trade. Over-collection and farming eventually destroyed leech habitats, wreaked environmental havoc and forced European merchants to seek new supply sources. Vast colonies of leeches were found to inhabit the immense wetlands of the Ottoman Empire, which soon became a major exporter of medicinal leeches. Following the Treaty of Balta Liman (1838), the Ottoman state moved to exert control over the lucrative trade, imposing a tax on leech gathering and contracting with tax-farmers (mültezim) to collect the taxes. British diplomats, merchants and other stakeholders protested the imposition of the tax, as had previously happened with the commodification of wildlife; their pursuit of profit led collectors and farmers to over-gather leeches, with catastrophic consequences. By the end of the century, so great had their worth climbed that the leech population faced extinction. This paper situates medicinal leeches as therapeutic actors of history and adopts an interscale approach in formulating the human-leech interaction. It offers a substantive contribution to the history of medicine, in revealing the centrality of leeches to the rise of modern medicine and global trade, but also by making visible their role in shaping imperial diplomacy and worldwide economic markets.

Effects of mammalian blood with different glucose levels on reproduction, growth and survival of the southern medicinal leech, Hirudo verbana Carena, 1820.

Medicinal leeches are generally fed using pure mammalian blood. In the present study reproduction, growth and survival of medicinal leeches (Hirudo spp.) fed by mammalian blood with modified glucose level were investigated for the first time. Leeches were fed by cattle blood in a final glucose level of 152 mg/dL (control group; Glucose-free), 200 mg/dL (G200 group), 300 mg/dL (G300 group), 500 mg/dL (G500 group), 750 mg/dL (G750 group), 1000 mg/dL (G1000 group), 2500 mg/dL (G2500 group) and 5000 mg/dL (G5000 group) with the addition of D-Glucose Monohydrate. Greatest growth performance was determined in the G2500 group with a specific growth rate of 2.34% (final body weight: 10.37 ± 3.86 g) (P < 0.05). A quadratic increase was observed in the body weight values of the leeches depending on the glucose dose (Plinear and Pquadratic < 0.05). The greatest survival and gravidity rates were 89% and 38%, respectively, in the G750 group (P < 0.05). The increased glucose level caused a sharp decrease in the survival and gravidity rates of leeches. The glucose level did not significantly effected the cocoon and offspring productivity (P > 0.05). According to the broken line model, optimum glucose levels based on growth, survival rate and gravidity rate were 2461 mg/dL, 750.0 mg/dL and 749.9 mg/dL, respectively. The study showed that, although the optimum growth performance was obtained in the G2500 group, blood with glucose level of 750 mg/dL should be used for profitable medicinal leech culture considering survival and gravidity rates.

Serotonin mediates stress-like effects on responses to non-nociceptive stimuli in the medicinal leech Hirudo verbana.

Noxious stimuli can elicit stress in animals that produce a variety of adaptations including changes in responses to nociceptive and non-nociceptive sensory input. One example is stress-induced analgesia that may be mediated, in part, by the endocannabinoid system. However, endocannabinoids can also have pro-nociceptive effects. In this study, the effects of electroshock, one experimental approach for producing acute stress, were examined on responses to non-nociceptive mechanical stimuli and nociceptive thermal stimuli in the medicinal leech (Hirudo verbana). The electroshock stimuli did not alter the leeches' responses to nociceptive stimuli, but did cause sensitization to non-nociceptive stimuli, characterized by a reduction in response threshold. These experiments were repeated with drugs that either blocked synthesis of the endocannabinoid transmitter 2-arachidonoylglycerol (2-AG) or transient receptor potential vanilloid (TRPV) channel, which is known to act as an endocannabinoid receptor. Surprisingly, neither treatment had any effect on responses following electroshock. However, the electroshock stimuli reliably increased serotonin (5-hydroxytryptamine or 5HT) levels in the H. verbana CNS. Injection of 5HT mimicked the effects of the electroshocks, sensitizing responses to non-nociceptive stimuli and having no effect on responses to nociceptive stimuli. Injections of the 5HT receptor antagonist methysergide reduced the sensitization effect to non-nociceptive stimuli after electroshock treatment. These results indicate that electroshocks enhance response to non-nociceptive stimuli but do not alter responses to nociceptive stimuli. Furthermore, while 5HT appears to play a critical role in this shock-induced sensitizing effect, the endocannabinoid system seems to have no effect.

The Vascularity of Ayurvedic Leech Therapy: Sensory Translations and Emergent Agencies in Interspecies Medicine.

This article offers vascularity as a multi-dimensional imaginary for the interspecies entanglements constituting Ayurvedic leech therapy. Whether, when, where, and how a leech decides to bite, suck, and release comprise pivotal junctures in leech therapy as practiced in southern Kerala, India. In the course of leech-human intra-actions, leeches translate matter, providing sensory mediation, relief, and amusement. Enmeshed in social and ecological relations inflected by gender, religion, class, and caste, this analysis of Ayurvedic leech therapy reframes questions of agencies starting with and from the viewpoint of the vascular capacities of leeches in their interactions with humans. This image of vascularity provides an analytic for the emergent agencies of humans and leeches constituted by sensory intra-actions at branching points in this multispecies clinical practice.

Effects of maternal age on reproductive performance of the southern medicinal leech, Hirudo verbana Carena, 1820.

Medicinal leeches can be used to address important needs in medicine and veterinary medicine, as well as pharmaceutical and cosmetic industries. These leeches, however, are among the endangered species. The reproductive processes of the medicinal leeches are not well-known. The aim of the present study was to elucidate effects of maternal age on reproductive performance of medicinal leeches (Hirudo sp.). This study was conducted on Hirudo verbana which were 1, 2 and 3 years of age. The results from the study indicate the youngest maternal leeches have greater reproductive performance. Cocoon production was 4.30 ± 0.72, 3.00 ± 0.71 and 2.80 ± 0.65 cocoons/leech at 1-, 2- and 3-years of age, respectively. Offspring production was greater in younger leeches with there being 11.16 ± 0.63, 10.60 ± 0.96 and 7.14 ± 1.20 offspring produced per cocoon when the cocoon was produced by leeches that were 1, 2, and 3 years of age, respectively. With increasing age of leeches producing the cocoon, the number of cocoons from which there are no offspring produced and the rate of abnormalities of cocoons and morphological abnormalities of offspring increased. The mortality rate of offspring was 10% and 40% in offspring from cocoons produced by 1- and 3-year-old leeches, respectively, being greater when from cocoons produced by 3-year old leeches. Consistent with these findings, younger maternal leeches during their first reproductive phase after hatching from a cocoon have the greatest reproductive performance and should be utilized in leech aquaculture enterprises.

[Effects of MT on growth and gonad development of natural overwintering Whitmania pigra].

The objectives of study were to explore the effects of exogenous methyltestosterone( MT) on the growth and gonadal development of overwintering Whitmania pigra. Before overwintering,0. 1,1. 0,10. 0,100. 0,150. 0 µg·L-1 of MT were added to the aquaculture water for 6 weeks. The changes of growth performance,gonad index,endogenous steroid hormones level and internal quality were measured after hibernate for 60 days. Then the tissue slice technique was used to observe the spermary( ovary) of Wh. pigra.The results showed that the body weight,survival rate and gonadal index increased first and then decreased with the increase of exogenous MT concentration; the male gland index was found the highest at the concentration of MT 10. 0 µg·L-1 and the female gland index was the highest at the concentration of MT 1. 0 µg·L-1. The survival rate of Wh. pigra peaked at the concentration of MT 10. 0 µg·L-1.The weight reaches a peak at a concentration of MT 100. 0 µg·L-1( P<0. 05). The number of primary spermatocytes in the testis was negatively correlated with the concentration of exogenous MT. The number of secondary spermatocytes and sperm cells increased first and then decreased. The concentration of secondary spermatocytes was the highest when the concentration of MT was 100. 0 µg·L-1.The number and volume of oocytes in the ovary and the yolk granules increased first and then decreased with the increase of exogenous MT concentration,and the highest was observed at the MT concentration of 100. 0 µg·L-1. The endogenous steroid hormone of Wh.pigra increased first and then decreased with the increase of exogenous MT concentration. The concentration of androgen and progesterone was the highest in MT 100. 0 µg·L-1 treatment( P<0. 05),and the concentration of estrogen was found the highest in MT 10. 0 µg·L-1 treatment( P<0. 05). After adding exogenous MT,Wh. pigra moisture content,acid-insoluble ash content,p H and anti-thrombin activity met the quality criterion of medicinal Wh. pigra in Chinese Pharmacopoeia( 2015 edition). In conclusion,the short-term addition of 1. 0-100. 0 µg·L-1 exogenous MT before hibernation can promote the growth,the development of sperm cells and the antithrombin activity of Wh. pigra.

Investigation of reproductive efficiency, growth performance and survival of the southern medicinal leech, Hirudo verbana Carena, 1820 fed with mammalian and poultry blood.

Medicinal leeches are one of the neglected organisms in animal reproduction studies. In this study, the effects of feeding two different types of blood, mammalian (cattle blood) and poultry (chicken blood), on the reproductive efficiency, growth performance and survival of the southern medicinal leech, Hirudo verbana, were investigated. The type of blood fed did not have a significant effect on the growth performance and survival of leeches, but the leeches fed chicken blood had a 2.5-fold greater performance compared to those fed cattle blood in terms of the gravidity process and reproductive efficiency. The final weight and survival for the cattle group was 10.79 ± 4.80 g and 87% and for the chicken group was 10.12 ± 5.26 g and 85%. Gravidity was initiated in the 7th month in both groups; however, while all gravidities in the leeches fed with chicken blood occurred in 1-month period, the gravidity of the leeches fed cattle blood occurred in a 3-month period. The cocoon efficiencies were 6.67 ± 1.50 cocoons/broodstock and 2.67 ± 3.37 cocoons/broodstock in the chicken and cattle groups, respectively. There were larger cocoons in the chicken compared to the cattle group. The offspring efficiencies were 12.59 ± 4.17 offspring/cocoon and 9.81 ± 3.67 offspring/cocoon in the chicken and cattle groups, respectively. The results of this study indicate poultry blood can be used in the management of broodstock with greater reproductive efficiency in medicinal leech aquaculture.

[Different arousal modes of hibernating Whitmania pigra].

To study the suitable arousal modes of hibernating Whitmania pigra, the biological characteristics, activity of amylase, lipase, and protease as well as morphologic structure of digestive tract were investigated by direct observational method and 3, 5-dinitrosalicylic acid colorimetry, p-nitrophenyl palmitate ester（p-NPP）colorimetry, folin-phenol and histological methods. The results revealed that Wh. pigra activity was increased with increases of the water temperature and prolonging treating duration. Except for the feeding groups of direct arousal mode at 24 h and 48 h, none of the other Wh. pigra groups died. Compared with that of normal groups, the digestive tract structure of hibernating Wh. pigra was looser and the mucosal folds of craw were more sparse. No obvious recovery was observed for the structure of the digestive tract before 48 h of direct arousal mode or the 5th day of 15 °C gradient arousal mode. The mucosal folds of craw increased and the muscularis were incrassated after 72 h of direct arousal mode or the 8th day of 20 °C gradient arousal mode, that indicated the tissue structure was approximately restored to the normal state. The digestive enzyme activities were increased with prolonging treating duration. And the feeding groups recovered faster than that of the no feeding groups. Additionally, the enzyme activities of feeding groups were significantly higher than that of no feeding groups (P<0.05) and approximately restored to the normal level after 48 h in the direct arousal mode or 20 °C in the gradient arousal mode. In conclusion, both of the two modes can be applied to the arouse of hibernating Wh. pigra, and it should be fed when the temperature is recovered to 15 °C or 20 °C at 2 °C·d⁻¹ in the gradient arousal mode after 72 h in the direct arousal mode to reduce the death ratio and improve effectively the economic profit of Wh. pigra aquaculture.

A double-sided microscope to realize whole-ganglion imaging of membrane potential in the medicinal leech.

Studies of neuronal network emergence during sensory processing and motor control are greatly facilitated by technologies that allow us to simultaneously record the membrane potential dynamics of a large population of neurons in single cell resolution. To achieve whole-brain recording with the ability to detect both small synaptic potentials and action potentials, we developed a voltage-sensitive dye (VSD) imaging technique based on a double-sided microscope that can image two sides of a nervous system simultaneously. We applied this system to the segmental ganglia of the medicinal leech. Double-sided VSD imaging enabled simultaneous recording of membrane potential events from almost all of the identifiable neurons. Using data obtained from double-sided VSD imaging, we analyzed neuronal dynamics in both sensory processing and generation of behavior and constructed functional maps for identification of neurons contributing to these processes.

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

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

[Study on correlation of oxygen consumption rate and suffocation point of Whitmania pigra and Bellamya purificata and optimum way of feeding Whitmania pigra].

The oxygen consumption, oxygen consumption rate and suffocation point of different quality Whitmania pigra and Bellamya purificata were determined by hydrostatic breathing room method. The effects of feeding modes on growth of W.pigra were determined by biomass. The results showed that the oxygen consumption correlated positively with the weight of W.pigra and B. purificata（P<0.05）, suffocation point increased with the increases of the weight（P<0.05）.Oxygen consumption correlated negatively with the weight of W. pigra, the oxygen consumption rate of B.purificata first increased and then decreased with the increasing of the weight. Feeding modes had no significant effects on the finial weight, SGR, WGR, death rates of W. pigra. Feeding modes had significant effects on eating ratio. It suggested that the optimum feeding frequency of W. pigra was once every three days. Scientific and reasonable feeding amount of B. purificata should be calculated based on oxygen consumption and suffocation point of W.pigra and B.purificata at every period. Meanwhile, stocking density, water area and water exchanging frequency should be taken into consideration.

[Studies on hibernation pivotal temperature of Whitmania pigra].

The biological characteristics, oxygen consumption, oxygen consumption rate, and activities of amylase, lipase and protease of Whitmania pigra at different temperature were studied by using direct observational method, the still water method and 3, 5-dinitrosalicylic acid colorimetry, right-nitrophenyl palmitate ester（ρ-NPP）colorimetry and folin-phenol method.The results revealed that with decreasing water temperature, the daily activity and the daily feeding ration were decreased. As the temperature was lowered to 4 ℃, the head and tail of Wh.pigra curved, showing a crescent-shape without feeding and daily activity. Oxygen consumption, oxygen consumption rate and digestive enzyme activities reduced along with temperature drops. The downward trend slowed below 10 ℃, began to stabilize below 4 ℃ and doesn't change with the decrease of temperature since then. During the 40 days treatment at 4 ℃, the changes of amylase were not significant, the lipase and protease activity decreased at the 20th day, and the lipase showed an slightly increase after the decrease and finally remained at a low level.In conclusions, the pivotal temperature of hibernation of Wh.pigra is 4 ℃ and the crescent shape can be considered as a symbol of hibernation.

Medical leech therapy in plastic reconstructive surgery.

The use of Hirudo medicinalis in clinical practice has increased in recent years. The primary indication in plastic surgery has traditionally been venous congestion. However, other reported clinical applications were in varicose veins, thrombophlebitis, and osteoarthritis. In this review, we summarize recent data elucidating the role that medicinal leeches play in the field of plastic surgery.

Basic morphofunctional features of pharmaceutic leech (Hirudo verbana Carena, 1820) tissues in various forms of response after hirudotherapeutic procedures.

It is analyzed morphofunctional features of Hirudo verbana tissues on histological sections in order to determine the possible causes of their partial death after hirudotherapeutic procedure. In the study was taken 4 groups of leeches: hungry (control), healthy well-fed, well-fed that vomited blood and well-fed dead. Morphofunctional changes in midgut of healthy well-fed H. verbana compared to the hungry are the changes of epithelium height through stretching eaten blood. In well-fed that vomited blood and well-fed dead leeches in the intestinal epithelium were observed degenerative processes that are accompanied by a decrease in the height of the epithelium, its partial desquamation. Botryoidal tissue of hungry leeches is in an inactive state, in healthy well-fed ones it responds with an increased physiological vascularization, activation of some botryoidal granulocytes with an increase in their average size, on receipt of the products of digestion. Activation of some botryoidal granulocytes, without a significant increase in their sizes, in well-fed leeches that vomited eaten blood and well-fed dead leeches, with increased infiltration of the adjacent connective tissue lymphocyte- and macrophage-like cells, amebocytes and granulocytes indicates the development of pathological processes, which are resulting in immunological conflict between eaten human blood and leeches' tissue microenvironment.

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

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.

Hirudotherapy in veterinary medicine.

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.

Scanning behavior in the medicinal leech Hirudo verbana.

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.

Medicinal leech therapy in pain syndromes: a narrative review.

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.

[Primary study of arginine as feed attractants on Whitmania pigra].

The effects of the feed attractants on Whitmania pigra were studied. The average weight of Wh. pigra were 5.0 g. Arginine was selected as feed attractants, xanthan gum was selected as feed substrate. The times of Wh. pigra going into the inducing room were recorded. The water temperature was 22-25 degrees C during the whole experiment. Arginine that had better inducing effect was chosen to carry on in the gradient experiment. The results showed that the best inducing effect was found when the added amount of arginine was 0.3%, which was close to the arginine content of the natural body fluid of Wh. Pigra and Bellamya purificata, 2.97 mg x g(-1).

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

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.