Малакологічні дослідження кафедри зоології Житомирського педуніверситету та їх значення в розвитку пізнавальних інтересів студентів і учнів

В статті розглянуто об’єкти і деякі напрямки досліджень малакологічної школи, а також значення та можливості використання досягнутих результатів в процесі навчання біології в школі

Trematode infection among freshwater gastropods in the Gharb area, Morocco

In the summer of 2012 and the spring of 2013, a snail survey aimed at determining relationships between the distribution of molluscan fauna, various environmental factors and trematode infection was carried out in the Gharb area, Morocco. The molluscan fauna consisted of eleven species belonging to 6 families, (including 9 gastropods and 2 bivalves). Cercariae belonging to five families were collected. Only Melanopsis praemorsa, Lymnea peregra and Lymnaea truncatula issued the cercariae. No case of mixed-species infections was found. The present study, first of its kind at the Gharb region, paved the way for other studies to know information about the distribution and ecology of freshwater molluscs in the region. Keywords : Cercariae, freshwater gastropods, Trematode infection, The Garb area, Morocco.

Reconnaissance of the Distribution and Abundance of Schistosomatium Douthitti, a Possible Human Disease Agent in Surface Waters in Alaska

Studies during the summer and early fall of 1967 show that Schistosomatium douthitti, a blood fluke which may pose a health hazard to man, is well established in the surface waters and surrounding terrestrial environments in the Fairbanks area. It is almost certain that this situation exists throughout Interior Alaska. Ecologically and geologically, the lakes and ponds in which it has been found are the most abundant types in the Interior and both the specific lakes and the types which they represent are abundantly used by man. The life cycle of the worm in this area is probably sustained mostly in small mammals, especially in Microtus pennsvlvanicus but also in Clethrionomys rutilus. The infection certainly over-winters in the mammal host but probably also survives in the snail host under the ice. Although the fluke was only found in two of the nine mammalian species examined, it is probable that it occurs in other than Microtus pennsvlvanicus and Clethrionomys rutilus.The work upon which this report is based was supported in part by funds provided by the U. S. Department of the Interior, Office of Water Resources Research, as authorized under the Water Resources Research Act of 1964. Project Number: A-O20- ALAS Agreement Number: 14-01-0001-89

Структура угруповань прісноводних легеневих молюсків Романівського району у водоймах різного типу

Прісноводні молюски – одна з найчисленніших груп безхребетних тварин у гідроценозах. Завдяки значній екологічній пластичності вони можуть траплятися в широкому спектрі водних біотопів, від невеликих за розмірами тимчасових до великих стоячих і текучих постійних водойм. Слід відмітити, що у більшості випадків молюски є „піонерами” у заселенні гідротопів з несприятливими для інших безхребетних гідробіонтів умовами існування. Їх поява ініціює кардинальні зміни в водоймі, які часто можуть супроводжуватися покращенням умов існування для інших груп гідробіонтів. Легеневі молюски (Pulmonata) – підклас черевоногих молюсків. Їхні розміри варіюють від 2-3 мм до кількох десятків сантиметрів. Характерною рисою цих молюсків є асиметричність будови, яка виражається у формі черепашки, редукції органів мантійного комплексу однієї сторони (здебільшого правої) та посиленим розвитком таких самих органів іншої сторони (здебільшого лівої)

Review on the Biology of Fasciola Parasites and the Epidemiology on Small Ruminants

Small ruminant fasciolosis is a serious problem in animal production in different areas of the world especially in Ethiopia. It is a wide spread trematodal disease affecting small ruminants (sheep and goats) and also other species of animals. Fasciola hepatica and Faciola gigantica are the parasitic species belonging to Genus Fasciola under the phylum platyhelminths. Fasciola hepatica was shown to be the most important fluke species in Ethiopian livestock and it requires snail of the genus Lymnae for the completion of its life cycle and its biological features; mainly its external body structures such as the teguments and spines besides the enzymes it secrets for exsheathment are responsible for its pathogenicity. Fasciola gigantica which is tropical species can exist up to 2600m of elevation although an effective transmission cycle in a single year can only be maintained at elevation below 1700m. Availability of suitable ecology for snail; temperature, moisture and pH are factors influencing the agent and its epidemiology. The course of the disease runs from chronic long lasting to acute rapidly fatal. These give rise to application of different diagnostic methods including fecal egg examination, post-mortem examination, immunological assessment and serological liver enzyme analysis. Therefore, people have to be aware of the significance (both economic and public health significance) and have to do all their best so as to minimize the occurrence or control the disease by taking measures like forecasting the occurrence, reduction of snail population, prophylactic use of anthelmintic and immunologic approach. Keywords: Fasciola, Biological characteristics, Small Ruminants, Epidemiolog

Insights into channel function via channel dysfunction

The nicotinic synapse has been a touchstone for advances in neuroscience ever since Jean Nicot, the French ambassador to Portugal, sent some tobacco seeds home to Paris in 1550 with a note that the New World plant had interesting effects when smoked. Now the muscle nicotinic acetylcholine receptor (nAChR) is a well-studied example of ligand-gated ion channels. After a motor neuron is stimulated, the nerve impulse reaches the presynaptic terminal, where it evokes release of acetylcholine (ACh) into the synapse. The nAChR depolarizes the postsynaptic muscle and triggers muscle action potentials; muscle contraction follows. To date, several nAChR subtypes have been successfully isolated, purified, imaged, and expressed, and unitary currents have been recorded from these channels (1). Researchers continue to unravel the molecular mechanisms of these macromolecules that are embedded in membranes at vertebrate nerve-muscle synapses, at invertebrate nicotinic synapses (which explains why nicotine-producing tobacco plants have a select advantage against invertebrate pests), and in the vertebrate central system (which explains Jean Nicot’s fascination with those leaves). However, the precise structural events that trigger channel opening or "gating" remain mostly unknown

Review on the Biology of Fasciola Parasites and the Epidemiology on Small Ruminants

Small ruminant fasciolosis is a serious problem in animal production in different areas of the world especially in Ethiopia. It is a wide spread trematodal disease affecting small ruminants (sheep and goats) and also other species of animals. Fasciola hepatica and Faciola gigantica are the parasitic species belonging to Genus Fasciola under the phylum platyhelminths. Fasciola hepatica was shown to be the most important fluke species in Ethiopian livestock and it requires snail of the genus Lymnae for the completion of its life cycle and its biological features; mainly its external body structures such as the teguments and spines besides the enzymes it secrets for exsheathment are responsible for its pathogenicity. Fasciola gigantica which is tropical species can exist up to 2600m of elevation although an effective transmission cycle in a single year can only be maintained at elevation below 1700m. Availability of suitable ecology for snail; temperature, moisture and pH are factors influencing the agent and its epidemiology. The course of the disease runs from chronic long lasting to acute rapidly fatal. These give rise to application of different diagnostic methods including fecal egg examination, post-mortem examination, immunological assessment and serological liver enzyme analysis. Therefore, people have to be aware of the significance (both economic and public health significance) and have to do all their best so as to minimize the occurrence or control the disease by taking measures like forecasting the occurrence, reduction of snail population, prophylactic use of anthelmintic and immunologic approach. Keywords: Fasciola, Biological characteristics, Small Ruminants, Epidemiolog

Acute and Chronic Toxicity of Cobalt to Freshwater Organisms: Using a Species Sensitivity Distribution Approach to Establish International Water Quality Standards

Water quality standards for cobalt (Co) have not been developed for the European Union or United States. The objective of the present study was to produce freshwater Co toxicity data that could be used by both the European Union and the United States to develop appropriate regulatory standards (i.e., environmental quality standards or predicted-no-effect concentrations in Europe and ambient water quality criteria or state water quality standards in the United States). Eleven species, including algae, an aquatic plant, and several invertebrate and fish species, were used in the performance of acute and chronic Co toxicity tests. Acute median lethal or median effective concentration (LC50 or EC50) values ranged from 90.1 mu g Co/L for duckweed (Lemna minor) to 157 000 mu g Co/L for midges (Chironomus tentans). Chronic 10% effect concentration (EC10) values ranged from 4.9 mu g Co/L for duckweed to 2170 mu g Co/L for rainbow trout (Oncorhynchus mykiss). Chronic 20% effect concentration (EC20) values ranged from 11.1 mu g Co/L for water flea (Ceriodaphnia dubia) to 2495 mu g Co/L for O. mykiss. Results indicated that invertebrate and algae/plant species are more sensitive to chronic Co exposures than fish. Acute-to-chronic ratios (derived as acute LC50s divided by chronic EC20s) were lowest for juvenile O. mykiss (0.6) and highest for the snail Lymnaea stagnalis (2670). Following the European-based approach and using EC10 values, species sensitivity distributions (SSDs) were developed and a median hazardous concentration for 5% of the organisms of 1.80 mu g Co/L was derived. Chronic EC20 values were used, also in an SSD approach, to derive a US Environmental Protection Agency-style final chronic value of 7.13 mu g Co/L

Neuronális és extraneuronális aminerg receptorok jellemzése gerinctelenekben = Characterization of neuronal and extraneuronal aminergic receptors in invertebrates

Radioaktív ligandok kötődésével vizsgáltuk az acetilkolin, szerotonin és dopamin receptorokat Lymnaea CNS-ben. A kolinerg ligandok kötődése nikotin és muskarin receptorok jelenlétét igazolták a CNS-ben. Nem kötődtek specifikusan és nagy affinitással az 5HT receptorok ligandjai és mérsékelt affinitású a dopamin receptor ligand kötődese. Az 3H-LSD az egyetlen ligand mely nagy affinitással kötődött mind a szerotonin, mind a dopamin receptorhoz. A kolinerg receptorok az evolúció során konzerválódtak, míg a szerotonin és dopamin receptorok gerincesekre jellemző típusai nem találhatók meg a puhatestűek idegrendszerében. A szárazföldi csigák a száraz meleg periódusokat inaktív "nyári álom" állapotban élik át. Ekkor metabolitikus aktivitásuk az aktív periódusra jellemzőnek csak a 20-30 %-a. Kísérleteinkben vizsgáltuk, hogy hogyan szabályozza a szerotonin és a dopamin az aktivációs/inaktivációs folyamatokat. Helix pomatia-ban. HPLC-s vizsgálatokkal kimutattuk, hogy az aktiváció során az idegrendszerben a MA szintje csökken, míg a szív és a talpizomban nő és szerotonin túlsúly alakul ki. A meg növekedett szerotonin szint az adenil cikláz stimulációja révén növelte a szövetek cAMP koncentrációját. A cAMP szint növekedése a protein kinazA aktivitásának serkentését eredményezte. A protein kinazA foszforilációval növelte egy 600 és egy 50 kDa molekulatömegű fehérje mennyiségét a szövetekben, melyek jelentős szereppel bírnak az izom kontrakciójának/relaxációjának szabályozásában. | We characterized acetylcholine, serotonin and dopamine receptors in the Lymnaea brain, using 3H-ligand binding methods. The ligands of cholinergic receptors bound with high affinity to the Lymnaea CNS and pharmacological properties of the binding suggest the presence of both nicotinic and muscarinic receptor types. No specific, high affinity binding of 5HT receptor ligands were found. The selective dopamine D1 and D2 receptors bound to the Lymnaea CNS with moderate affinity. The 3H-LSD was the single ligand displaying a high affinity binding to both serotonin and dopamine receptors. Terrestial snails are aestivated for several weeks, when the surrunding humidity becomes low. During this dormant state the overall metabolic rate depressed to a level of only 20-30 % of that of active snails. Our aim was to study how 5HT and DA are involved in the regulation of activatio/inactivation process in Helix pomatia. HPLC assay show that in Helix heart and foot there is a 5HT dominance and this dominance became more significant in active animals. The increased level and dominance of 5HT resulted in a increase of the concentration of cAMP by stimulating the adenylate cyclase. The high cAMP concentration stimulated the cAMP dependent protein kinaseA activity resulting in the phosphorylation a high (600 kDa) and a low (50 kDa) molecular weight protein involved in the regulation of the relaxation/contraction of the muscle