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PLoS Pathogens Jul 2023Schistosomiasis, a severe parasitic disease, is primarily caused by Schistosoma mansoni, Schistosoma japonicum, or Schistosoma haematobium. Currently, praziquantel is... (Review)
Review
Schistosomiasis, a severe parasitic disease, is primarily caused by Schistosoma mansoni, Schistosoma japonicum, or Schistosoma haematobium. Currently, praziquantel is the only recommended drug for human schistosome infection. However, the lack of efficacy of praziquantel against juvenile worms and concerns about the emergence of drug resistance are driving forces behind the research for an alternative medication. Schistosomes are obligatory parasites that survive on nutrients obtained from their host. The ability of nutrient uptake depends on their physiological structure. In short, the formation and maintenance of the structure and nutrient supply are mutually reinforcing and interdependent. In this review, we focus on the structural features of the tegument, esophagus, and intestine of schistosomes and their roles in nutrient acquisition. Moreover, we introduce the significance and modes of glucose, lipids, proteins, and amino acids intake in schistosomes. We linked the schistosome structure and nutrient supply, introduced the currently emerging targets, and analyzed the current bottlenecks in the research and development of drugs and vaccines, in the hope of providing new strategies for the prevention and control of schistosomiasis.
Topics: Animals; Humans; Praziquantel; Schistosomiasis; Schistosoma japonicum; Schistosoma haematobium; Schistosoma mansoni; Eating
PubMed: 37498810
DOI: 10.1371/journal.ppat.1011498 -
BioMed Research International 2020Planarians are bilaterally symmetric metazoans of the phylum Platyhelminthes. They have well-defined anteroposterior and dorsoventral axes and have a highly structured... (Review)
Review
Planarians are bilaterally symmetric metazoans of the phylum Platyhelminthes. They have well-defined anteroposterior and dorsoventral axes and have a highly structured true brain which consists of all neural cell types and neuropeptides found in a vertebrate. Planarian flatworms are famous for their strong regenerative ability; they can easily regenerate any part of the body including the complete neoformation of a functional brain within a few days and can survive a series of extreme environmental stress. Nowadays, they are an emerging model system in the field of developmental, regenerative, and stem cell biology and have offered lots of helpful information for these realms. In this review, we will summarize the response of planarians to some typical environmental stress and hope to shed light on basic mechanisms of how organisms interact with extreme environmental stress and survive it, such as altered gravity, temperature, and oxygen, and this information will help researchers improve the design in future studies.
Topics: Animals; Brain; Models, Biological; Neurons; Planarians; Regeneration; Stem Cells; Stress, Physiological
PubMed: 32596359
DOI: 10.1155/2020/7164230 -
Current Biology : CB Sep 2022A recent paper suggests that the flatworm Schmidtea mediterranea has an autosome that is 'primed' to evolve into a sex chromosome. However, this chromosome could be a...
A recent paper suggests that the flatworm Schmidtea mediterranea has an autosome that is 'primed' to evolve into a sex chromosome. However, this chromosome could be a balanced-lethal system and may illuminate these puzzling systems.
Topics: Animals; Platyhelminths; Sex Chromosomes
PubMed: 36099896
DOI: 10.1016/j.cub.2022.07.043 -
PeerJ 2024Cancer is one of the leading causes of death, with an estimated 19.3 million new cases and 10 million deaths worldwide in 2020 alone. Approximately 2.2 million cancer... (Review)
Review
Cancer is one of the leading causes of death, with an estimated 19.3 million new cases and 10 million deaths worldwide in 2020 alone. Approximately 2.2 million cancer cases are attributed to infectious diseases, according to the World Health Organization (WHO). Despite the apparent involvement of some parasitic helminths (especially trematodes) in cancer induction, there are also records of the potential suppressive effects of helminth infections on cancer. Tapeworms such as , , and more seem to have the potential to suppress malignant cell development, although in a few cases the evidence might be contradictory. Our review aims to summarize known epidemiological data on the cancer-helminth co-occurrence in the human population and the interactions of tapeworms with cancers, ., proven or hypothetical effects of tapeworms and their products on cancer cells (., in experimental animals) or . The prospect of bioactive tapeworm molecules helping reduce the growth and metastasis of cancer is within the realm of future possibility, although extensive research is yet required due to certain concerns.
Topics: Animals; Humans; Cestoda; Taenia; Cestode Infections; Helminthiasis; Helminths; Neoplasms
PubMed: 38563013
DOI: 10.7717/peerj.17196 -
Journal of Travel Medicine Feb 2023
Topics: Animals; Humans; Mites; Schistosoma haematobium; Schistosomiasis haematobia; Schistosoma mansoni
PubMed: 35678646
DOI: 10.1093/jtm/taac076 -
BMC Neuroscience May 2023Despite large morphological differences between the nervous systems of lower animals and humans, striking functional similarities have been reported. However, little is...
BACKGROUND
Despite large morphological differences between the nervous systems of lower animals and humans, striking functional similarities have been reported. However, little is known about how these functional similarities translate to cognitive similarities. As a first step towards studying the cognitive abilities of simple nervous systems, we here characterize the ongoing electrophysiological activity of the planarian Schmidtea mediterranea. One previous report using invasive microelectrodes describes that the ongoing neural activity is characterized by a 1/f power spectrum with the exponent 'x' of the power spectrum close to 1. To extend these findings, we aimed to establish a recording protocol to measure ongoing neural activity safely and securely from alive and healthy planarians under different lighting conditions using non-invasive surface electrodes.
RESULTS
As a replication and extension of the previous results, we show that the ongoing neural activity is characterized by a 1/f power spectrum, that the exponent 'x' in living planarians is close to 1, and that changes in lighting induce changes in neural activity likely due to the planarian photophobia.
CONCLUSIONS
We confirm the existence of continuous EEG activity in planarians and show that it is possible to noninvasively record this activity with surface wire electrodes. This opens up broad possibilities for continuous recordings across longer intervals, and repeated recordings from the same animals to study cognitive processes.
Topics: Animals; Humans; Planarians; Electroencephalography
PubMed: 37138236
DOI: 10.1186/s12868-023-00799-z -
Parasitology Apr 2021Identifying the factors that structure host–parasite interactions is fundamental to understand the drivers of species distributions and to predict novel cross-species...
Identifying the factors that structure host–parasite interactions is fundamental to understand the drivers of species distributions and to predict novel cross-species transmission events. More phylogenetically related host species tend to have more similar parasite associations, but parasite specificity may vary as a function of transmission mode, parasite taxonomy or life history. Accordingly, analyses that attempt to infer host−parasite associations using combined data on different parasite groups may perform quite differently relative to analyses on each parasite subset. In essence, are more data always better when predicting host−parasite associations, or does parasite taxonomic resolution matter? Here, we explore how taxonomic resolution affects predictive models of host−parasite associations using the London Natural History Museum's database of host–helminth interactions. Using boosted regression trees, we demonstrate that taxon-specific models (i.e. of Acanthocephalans, Nematodes and Platyhelminthes) consistently outperform full models in predicting mammal-helminth associations. At finer spatial resolutions, full and taxon-specific model performance does not vary, suggesting tradeoffs between phylogenetic and spatial scales of analysis. Although all models identify similar host and parasite covariates as important to such patterns, our results emphasize the importance of phylogenetic scale in the study of host–parasite interactions and suggest that using taxonomic subsets of data may improve predictions of parasite distributions and cross-species transmission. Predictive models of host–pathogen interactions should thus attempt to encompass the spatial resolution and phylogenetic scale desired for inference and prediction and potentially use model averaging or ensemble models to combine predictions from separately trained models.
Topics: Acanthocephala; Animals; Host-Parasite Interactions; Mammals; Models, Biological; Nematoda; Phylogeny; Platyhelminths; Spatial Analysis
PubMed: 33342442
DOI: 10.1017/S0031182020002371 -
International Journal For Parasitology.... Apr 2022Parasitic diseases are major constraints in fish mariculture. The anthelmintic praziquantel (PZQ) can effectively treat a range of flatworm parasites in a variety of... (Review)
Review
Parasitic diseases are major constraints in fish mariculture. The anthelmintic praziquantel (PZQ) can effectively treat a range of flatworm parasites in a variety of fish species and has potential for broader application than its current use in the global aquaculture industry. In this review we report on PZQ's current use in the aquaculture industry and discuss its efficacy against various flatworm parasites of fish. Routes of PZQ administration are evaluated, along with issues related to palatability, pharmacokinetics and toxicity in fish, while PZQ's effects on non-target species, environmental impacts, and the development of drug-resistance are discussed.
Topics: Animals; Anthelmintics; Aquaculture; Platyhelminths; Praziquantel
PubMed: 35220160
DOI: 10.1016/j.ijpddr.2022.02.001 -
Toxicon : Official Journal of the... Sep 2022The marine polyclad flatworm Planocera multitentaculata is known to possess high levels of tetrodotoxin (TTX), but the presence of TTX analogues in the species has been...
The marine polyclad flatworm Planocera multitentaculata is known to possess high levels of tetrodotoxin (TTX), but the presence of TTX analogues in the species has been unexplored. In this study, TTX and several analogues such as 5,6,11-trideoxyTTX, monodeoxyTTXs, dideoxyTTXs, and 11-norTTX-6(S)-ol were identified in three adults and egg plates of P. multitentaculata using high resolution liquid chromatography-mass spectrometry (HR-LC/MS) for the first time.
Topics: Animals; Chromatography, Liquid; Mass Spectrometry; Platyhelminths; Tetrodotoxin
PubMed: 35843466
DOI: 10.1016/j.toxicon.2022.07.001 -
Acta Tropica Feb 2022Cystic echinococcosis (CE) and alveolar echinococcosis (AE) are the two most important global parasitic infectious diseases caused by species of Echinococcus granulosus... (Review)
Review
Cystic echinococcosis (CE) and alveolar echinococcosis (AE) are the two most important global parasitic infectious diseases caused by species of Echinococcus granulosus and E. multilocularis, respectively. Although numerous trials have been performed in search of novel therapeutic options to curb the neglected zoonosis, no other nonsurgical options are currently available to replace the licensed anti echinococcal drugs albendazole (ABZ) and mebendazole (MBZ). A safer and more effective treatment plan for echinococcosis is therefore urgently needed to compensate for this therapeutic shortfall. Here, we present a review of the literature for state-of-the-art valuable anti-parasitic compounds and novel strategies that have proved effective against CE and AE, which includes details about the pharmaceutical type, practical approach, experimental plan, model application and protoscolecidal effects in vivo and in vitro. The content includes the current application of traditional clinical chemicals, the preparation of new compounds with various drug loadings, repurposing findings, combined programs, the prospects for Chinese herbal medicines, non-drug administrations and the exploration of target inhibitors based on open-source information for parasitic genes. Next the conventional experimental projects and pharmacodynamic evaluation methods are systematically summarized and evaluated. The demands to optimize the construction of the echinococcosis model and improve the dynamic monitoring method in vivo are also discussed given the shortcomings of in vivo models and monitoring methods.
Topics: Albendazole; Animals; Echinococcosis; Echinococcus granulosus; Echinococcus multilocularis; Mebendazole
PubMed: 34808118
DOI: 10.1016/j.actatropica.2021.106252