Influence of residual antegrade coronary blood flow on the long-term prognosis of medically treated patients with myocardial infarction and single-vessel disease

This is a review article concerning an influence of trematodes infections on a defence system of snails. Changes in: snails' plasma composition, a number of hemocytes, size of a hemopoietic organ, molecules secreted by hemocytes and defence cells activities caused by the infections are discussed in detail. The differences in humoral and cellular response between susceptible and resistant strains of snails as well as between young and old snails are also presented in the article. Finally, the problem of an existence of the specific immunological memory in snails is analyzed.     

Mitochondrial ND1 gene sequences used to identify echinostome isolates from Australia and New Zealand

Echinostomes were collected in Australia and New Zealand as cercariae, metacercariae or adults. Using DNA sequences from the mitochondrial ND1 gene Echinostoma revolutum and Echinostoma paraensei were discovered in Australia. The presence of a further five, as yet unidentified, echinostome species was inferred in Northern Australia and a further isolate, closely allied to E. revolutum, occurs in New Zealand. ND1 sequences of species within the genus diverge from each other by 9.6-30.8%. Sequence divergence levels among strains within a single species are 0-3.6%. The phylogenetic tree produced from the Australasian isolates, in addition to species described previously, identifies the 37-collar-spine species as a well supported monophyletic group. The five unidentified Australian species cluster away from the 37-collar-spine group. These unidentified species appear to divide further into > 37-collar-spine and < 37-collar-spine clusters. Three strains of E. revolutum, collected as metacercariae from snails, were identified from two ponds located 6 km apart. Two of these strains may be cycling through a planorbid snail, Glyptophysa sp., as first intermediate host; however, this hypothesis could not be confirmed as specimens could not be obtained to match sequences between larvae and adults.     

Developmental plasticity of respiratory behavior in Lymnaea

The authors investigated the contribution of experience to development and maintenance of pulmonary respiration in Lymnaea stagnalis. Respiration in L. stagnalis is bimodal via both the skin and the lung. Rearing snails from eggs to adulthood while preventing lung respiration (differentially reared snails) showed that L. stagnalis can develop and survive without pulmonary respiration. These snails were able to open and close their pneumostome when given the opportunity as adults. However, quantitative aspects of their respiratory behavior were significantly altered. Prevention of pulmonary respiration in adult, normally reared snails also induced behavioral changes. Comparison of these changes with those in differentially reared snails revealed specific developmental effects, which were reversible. Thus, this is a suitable model system for studying questions related to behavioral plasticity.     

Intraarterial infusion of anti-cancer agents. (A suitable technic introducing a polyethylene tube, with angiographic visualization, through the deep femoral artery directly into the artery in the abdomen selected for injection, using two kinds of guidewires) (author''s transl)

The authors have infected 127 B. glabrata by 2 miracidia of S. mansoni, either on the Same day, or introducing a second miracidium after 3, 7 and 16 days. 1 All the groups of planorbid snails had a low percentage of positivity (31 to 41 %). 2 The first cercarial emissions, in the 4 groups were scattered in the time, the delay being in correlation with the second infection. 3 In the snails reinfected after 3 and 7 days occured the highest emissions, those with the simultaneous double infection or second infection delayed to 16 days, had the lesser emissions. 4 An interval cycle of about 3 weeks was discovered for the highest emissions. All those phenomena are probably due to competition between the sporocysts born from both miracidia. Moreover, evident reduction of the fecundity in the positive snails were shown only after the beginning of the cercarial emissions, while a normal, or even increased fecundity was established in the prepatent period of the infected snails.     

Detection of Ehrlichia risticii, the agent of Potomac horse fever, in freshwater stream snails (Pleuroceridae: Juga spp.) from northern California

Ehrlichia DNA was identified by nested PCR in operculate snails (Pleuroceridae: Juga spp.) collected from stream water in a northern California pasture in which Potomac horse fever (PHF) is enzootic. Sequencing of PCR-amplified DNA from a suite of genes (the 16S rRNA, groESL heat shock operon, 51-kDa major antigen genes) indicated that the source organism closely resembled Ehrlichia risticii, the causative agent of PHF. The minimum percentage of Juga spp. harboring the organism in the population studied was 3.5% (2 of 57 snails). No ehrlichia DNA was found in tissues of 123 lymnaeid, physid, and planorbid snails collected at the same site. These data suggest that pleurocerid stream snails may play a role in the life cycle of E. risticii in northern California.     

Fasciola hepatica: a study of the shedding of cercariae from Lymnaea truncatula raised under constant conditions of temperature and photoperiod

Investigations on the shedding of cercariae of Fasciola hepatica were carried out in Lymnaea truncatula in order to verify the existence of a low-frequency periodicity in the numerical distribution of metacercariae per snail and per day when the snails are raised under controlled conditions. Preadult L. truncatula were thus collected in the field, individually exposed to two miracidia, and subsequently raised until their death under constant temperature (20 degrees C) and photoperiod (12 h/12 h diurnal rhythm). The 102 snails shedding parasites produced 24,325 metacercariae of which 5% were floating cysts. The daily production of cercariae was maximal during the first 30 days of the patent period, subsequently decreased until day 114, and ceased on day 124. No infradian-type rhythm was noted in the daily distribution of mean values. The snails shed their cercariae in one to 14 waves; 20.6% and 15.7% of the snails produced their parasites in four and five periods respectively. The authors suggest that the seven-day periodicity found by Audousset et al. (1989) in the daily distribution of cercariae produced by three colonies of L. truncatula raised in seminatural conditions must be attributed only to the influence of environmental factors.     

Host choice by larval parasites: a study of Biomphalaria glabrata snails and Schistosoma mansoni miracidia related to host size

Within snail/trematode associations the age/size of the host at infection has consequences with regard to miracidial infection success, further intramolluscan parasite development and reproduction, and the host response, mainly in terms of growth and reproductive effort. Taking into account these differences, we were interested in determining whether miracidia could discriminate and make a choice between snails of different sizes. Using the Schistosoma mansoni/Biomphalaria glabrata system, we compared data on the snail infection rate and the mother sporocyst abundance among three size classes of snails (juvenile, subadult, and adult) exposed separately or together to the parasite larvae. When exposed individually, juvenile snails (3-5 mm) had significantly higher prevalence and abundance values than did subadult snails, followed by adult snails. In contrast, when snails of the three size classes were exposed together in heterogeneous size groups the prevalence and abundance values were always significantly higher for subadult snails of the 7- to 9-mm class than for juvenile and adult snails. A host choice experiment confirmed that significantly more miracidia were attracted by subadult snails, suggesting that the parasite has been selected for specific locating and recognition mechanisms increasing the infection rate of subadult snails when the latter have been exposed in a heterogeneous size group. Selective forces that may be responsible for such a preferential infectivity of the parasite vis-à-vis particular host age/size class are discussed in relation to host resources and host responses.     

Oligodendroglioma with signet-ring cell morphology: a case report with an immunohistochemical and ultrastructural study

Clinical reports have suggested an unusual frequency in the number of patients with food allergy to snails who are also allergic to the house-dust mite (HDM). As allergy to HDM is one of the most frequent sensitizations in atopic patients of Western countries, evaluation of the relevance of the concomitant sensitization to Dermatophagoides pteronyssinus and to snails is an important consideration. To evaluate the responsibility of different snail components and of snail mites for inducing in vivo hypersensitivity in patients allergic to HDM, the in vivo reactivity of patients with clinical symptoms after ingestion of snails was assessed by skin prick tests with extracts and hemolymph from four different Helix species snails, and extracts from the snail parasitic mite, Riccardoella limacum. In addition, to obtain epidemiologic data on cosensitization to HDM and snails in allergic patients, the frequency of snail sensitization and its relationship to HDM sensitization were determined in a population of 169 allergic children. All patients allergic to snails had positive skin prick tests to the snail extracts and none to R. limacum extract. The number of positive skin reactions did not significantly differ whatever the species, snail part, or heating procedure used. The strongest reactions were obtained with Helix pomatia (Burgundy snail). Among the 169 prospectively tested children, 38 had a positive prick test to snail extracts; 79% of the snail-sensitized children had sensitization to HDM; and 31% of the children allergic to HDM were found to be sensitized to snails. These results show that snail components, and not the mite R. limacum, were responsible for the in vivo hypersensitivity. These snail components reacting in vivo are present in different parts of snails, including the hemolymph. One-third of the children allergic to HDM were sensitized to snails without any previous ingestion of snails: this observation suggests that HDM was the sensitizing agent and that the cross-reaction could be clinically relevant in countries where eating snails is common.     

Density-dependent foraging strategy of a large carnivorous lizard, the savanna monitor (Varanus albigularis).

Captive, subadult white-throated savanna monitor lizards (Varanus albigularis; n?=?15) were tested in a prey density-dependent foraging experiment. Within a test arena individual lizards were offered 10 large and 10 small snails in both a large and small circular area. Results showed that at high prey density, these lizards selected large over small snails. At low prey densities, however, large and small snails were selected at an equal rate. Apparently, when prey densities are high, the lizards have the opportunity to select the larger prey items without incurring locomotor costs. These data support optimal foraging theory but are unique in that they are an example from a little-studied, widely foraging species of lizard. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Chloroethylclonidine and alpha-adrenoceptor agonist interaction in blood vessels following heart failure

We compare and contrast the putative mechanisms underlying CO2 chemoreceptor function in air breathing vertebrates and terrestrial pulmonate snails. We discuss the role of intracellular pH (pHi) in central respiratory responses to CO2 and describe a variety of patterns of pHi regulation in chemosensory areas. One pattern, in which pHi retains a fixed relationship to the CO2 stimulus over time, seems well suited to chemoreceptor cells. Alphastat regulation of ventilation is apparent in both air breathing vertebrates and terrestrial pulmonate snails. Diethyl pyrocarbonate inhibits respiratory responses to hypercapnia in both groups of animals. The neuronal basis of chemosensitivity is similar, in that putative chemoreceptor cells depolarize during hypercapnic stimulation, but the ionic basis of excitability appears to be a potassium conductance in the vertebrates studied to date and a calcium conductance in the snails. Despite divergent evolutionary histories, chemosensory responses and mechanisms are remarkably similar in air breathing vertebrates and terrestrial pulmonate snails.     

Allergic contact dermatitis from cobalt in animal feed

A 39-year-old woman with systemic lupus erythematosus suffered a prolonged neurological illness associated with very low levels of glucose in her cerebrospinal fluid (CSF). Six months later, and after numerous CSF investigations, Histoplasma capsulatum was cultured. To our knowledge, this is the first report of cerebral histoplasmosis in Australia in a patient who is not HIV positive.     

Dr Eliza Foster McDonogh Frikart: advertiser

Eliza Frikart was the first woman doctor registered in New Zealand. She moved round Australia and New Zealand and advertised her presence wherever she went. She was struck off the British register.     

Isozyme polymorphism of esterases in the genus Lanistes (Mollusca:Prosobranchiata) and genetic analysis of populations

Esterases from the digestive gland of the snails Lanistes carinatus and Lanistes bolteni collected from Egyptian governorates were extracted and analyzed using starch gel electrophoresis and five substrates. Twelve esterase bands were detected in both Lanistes species. The esterase bands were distributed in three main zones, which could be classified as acetylesterases, carboxylesterases, and cholinesterases. Depending on the substrates specificity, inhibition properties, and relative mobility of esterase bands, the three zones of esterase activity could be traced to eight genetic loci. Locality-specific loci were found. Inter- and intrapopulation variations are discussed. There is an absence of equilibria at all esterase loci in all populations studied, and a high proportion of genetic diversity in different esterase loci. The absence of interspecific variations proves that Lanistes snails in Egypt belong to one species.     

Invasion of the Nile Valley in Egypt by a hybrid of Biomphalaria glabrata and Biomphalaria alexandrina, snail vectors of Schistosoma mansoni

Two years (1996-1997) of systematic survey showed that a hybrid of Biomphalaria glabrata and Biomphalaria alexandrina has invaded the irrigation and drainage systems in the Nile Delta and the Valley nor the of El-Menya. However, the infestation of water courses by and the population density of this snail were variable in various localities. The infestation rate ranged between 7.1% in El-Fayoum Governorate and 52.6% in El-Dakahliya Governorate and the snail density from 2 snails/site to 69.7 snails/site in the same governorates, respectively. Comparing the survey results of the two study years in the sampling sites indicated that the hybrid snail has relatively increased in population density than B. alexandrina. The hybrid snail of B. glabrata and B. alexandrina was found alone in some sites, but was mostly associated with B. alexandrina. The results showed also that both Biomphalaria have almost the same major physicochemical requirements. However, the hybrid snails and B. alexandrina were found differently associated with aquatic snails and plants. The hybrid snail was found naturally infected with S. mansoni thus giving indication that it is presently participating in schistosomiasis mansoni transmission in Egypt.     

Neuromuscular patterns and the origin of trophic specialization in fishes

The pattern of muscle electrical activity in the pharyngeal muscles of the mollusc-eating sunfish Lepomis microlophus is highly specialized in comparison with the pattern displayed by most other members of the sunfish family and does not change when different prey are eaten. The closest genealogical relative of this species has the specialized muscle activity pattern for crushing prey when it feeds on snails but uses the primitive sequence of muscle activity during swallowing of other prey. The ability of species that crush snails to use molluscan prey effectively is due primarily to the evolutionary transformation of the neuromuscular program controlling the trophic apparatus.     

A polymerase chain reaction assay for detecting snails infected with bilharzia parasites (Schistosoma mansoni) from very early prepatency

In the present study, we adapted a polymerase chain reaction (PCR) assay, previously shown by us to be very sensitive for detecting cercariae in water, for the sensitive detection of Schistosoma mansoni DNA in infected snails from early prepatency. Polymerase chain reaction primers were designed based on the 121-basepair highly repeated sequence we previously identified in the genome of S. mansoni. The DNA was prepared from the snails by a simple alkaline extraction procedure, and the PCR assay enabled a clear differentiation between infected and normal snails. Infected snails were detected as early as one day after penetration of a single miracidium. The high sensitivity of the test enabled identification of a single infected snail even when its DNA was pooled with material from up to 99 uninfected snails, thus demonstrating the possibility of mass diagnosis in pools of snails. The assay has the potential for large-scale determination of prepatent infection prevalence in snails, thus offering new possibilities for the evaluation of schistosomiasis transmission and for schistosomiasis control, as discussed.     

Increased neopterin in patients with chronic and acute coronary syndromes

The effect of aprotinin on Schistosoma mansoni miracidial penetration process, by its direct topical application on Biomphalaria alexandrina snails, was studied The snails were exposed to S. mansoni miracidial suspension which was mixed with aprotinin at concentrations ranging from 0.02 to 20 Kallikrein inactivator units (KIU)/ml of applied solution. Results showed that aprotinin had marked inhibitory effect on miracidial penetration of the snails. The concentration that resulted in 50% inhibition of the miracidial penetration into B. alexandrina snails (LD50) was 2.4 KIU/ml while (LD96) was 20 KIU/ml of the applied solution. Thus, aprotinin may be one of the important methods in the control of schistosomiasis.     

The suitability of Trochoidea seetzenii of different ages as snail intermediate hosts of Muellerius cf. capillaris (Nematoda:Protostrongylidae)

Larval development of Muellerius cf. capillaris in small (1st-year juveniles, shell diameter 0.96 +/- 0.05 cm) and medium-size (2nd-year juveniles, 1.27 +/- 0.06 cm) Trochoidea seetzenii land snails was significantly more rapid than in large adult snails (1.96 +/- 0.09 cm). Only 9% of the inoculated 1st-stage larvae (400 +/- 20 per snail) were recovered from the large snails as compared to 25% from the medium and small snails. Of the exposed small snails, however, only 35% survived to the end of the experiment (33 days post-infection) as compared to a 97.5% and 98% survival rates for the same period in the medium and large adult snails, respectively.     

Recombinant human interleukin-1-mediated killing of Schistosoma mansoni primary sporocysts in Biomphalaria glabrata

Previous work has indicated that injection of recombinant-human interleukin (rhIL)-1beta in Schistosoma mansoni-infected M-line Biomphalaria glabrata resulted in a significant reduction in the number of cercariae shed. The purpose of the present work was to determine if primary sporocysts were killed following rhIL-1beta injection in susceptible snails and, if so, to determine if killing was the direct result of hemocyte activity. Counting of primary sporocysts indicated a 50% reduction in the number surviving at 3 days PE in snails from 2 susceptible strains following injection. Histological analysis indicated that killing occurred with little-to-no observable hemocyte/parasite contact, whereas short-term culture of primary sporocysts with cell-free plasma (hemolymph) from injected snails rapidly initiated killing in vitro. Because levels of a snail IL-1-like molecule (SnaIL-1) drop significantly following schistosome exposure in M-line snails, because resistant snails maintain higher SnaIL-1 levels following infection, and because rhIL-1beta upregulates hemocyte cytotoxic mechanisms, these data support the contention that SnaIL-1 plays a role in determining resistance in B. glabrata. These data also indicate that schistosome death may be separated from parasite encapsulation by hemocytes and that an as yet unidentified humoral killing mechanism/factor may exist in B. glabrata. Lastly, these data further support the hypothesis that cytokine-like molecules are important, functionally conserved immunodefense mediators in both vertebrates and invertebrates.