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1.
J Forensic Sci ; 66(5): 2006-2009, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34145581

RESUMO

Lethal jellyfish envenoming is a very rare event. Two illustrative cases of fatalities following envenomation from the multi-tentacled box jellyfish, Chironex fleckeri, are reported that involved a six-year-old boy and a three-year-old girl, both of whom had been playing in shallow beach waters in remote Northern Territory communities (Australia). A recommended approach to autopsy in suspected cases is described, which should include examination of the clothing and skin surfaces for the fine tentacles of Chironex fleckeri. In addition, the combined length and maximum width of tentacle marks should be measured/calculated and collection of unfixed tentacles with adhesive tape onto a glass slide should be undertaken to check for nematocysts. Such rare cases show that children are at higher risk of a lethal outcome, particularly if they are resident in remote coastal tropical communities.


Assuntos
Mordeduras e Picadas/complicações , Venenos de Cnidários/envenenamento , Cubomedusas , Animais , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Nematocisto/ultraestrutura
2.
Sci Rep ; 11(1): 10280, 2021 05 13.
Artigo em Inglês | MEDLINE | ID: mdl-33986430

RESUMO

Cubozoan jellyfish are classified as plankton despite the strong swimming and orientation abilities of cubomedusae. How these capabilities could affect cubozoan population structures is poorly understood. Medusae of the cubozoan Copula sivickisi can uniquely attach to surfaces with the sticky pads on their bells. Biophysical modelling was used to investigate the spatial scales of connectivity in a C. sivickisi population. When the medusae were active at night they could maintain their observed distribution on fringing reef if they attached to the reef when the current speed exceeded a moderate threshold. This behaviour facilitated the isolation of a C. sivickisi population on reefs fringing Magnetic Island, Queensland, Australia. Within this distribution, there was considerable within bay retention and medusae rarely travelled > 3 km. The few (< 0.1%) medusae lost from the island habitat were largely advected into open water and away from the mainland coast which lies 8 km from the island. Given that successful emigration is unlikely, the island population probably represents a stock that is ecologically distinct from any mainland populations. The cosmopolitan distribution of C. sivickisi could contain incipient or cryptic species given the small scales of connectivity demonstrated here.


Assuntos
Comportamento Animal , Cubomedusas/fisiologia , Oceanografia , Animais , Recifes de Corais , Queensland
3.
Zoolog Sci ; 38(2): 170-178, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33812356

RESUMO

The exumbrellar surfaces of six pelagic cnidarians from three classes were ultra-structurally compared to reveal their structural diversity in relation to their gelatinous, transparent bodies. We examined two hydrozoans (Diphyes chamissonis and Colobonema sericeum), a cubozoan (Chironex yamaguchii), and three scyphozoans (Atolla vanhöffeni, Aurelia coerulea, and Mastigias papua). The exumbrellar surfaces of the mesoglea in D. chamissonis, Ch. yamaguchii, Au. coerulea, and M. papua were covered with a simple epidermis; the shapes of the epidermal cells were remarkably different among the species. The epidermal cells of Ch. yamaguchii and M. papua possessed an array of microvilli on the apical side. The array possibly reduced light reflectance and provided some other surface properties, as seen for the cuticular nipple array in tunicates, considering the length, width, and pitch of the microvilli. The reduction of light reflectance on the array of microvilli was supported by the simulation with rigorous coupled wave analysis (RCWA). Microvilli were sparse and did not form an array in metephyrae of Au. coerulea. The mesoglea matrix beneath the basal side of the epidermis was loose in all of the species. The exumbrellar side of the mesoglea was exposed only in the mesopelagic species, At. vanhöffeni and Co. sericeum, and electron-dense layer(s) covered the surface of the mesoglea. It is uncertain whether the exumbrellar epidermis is absent in these species or the epidermal cells are completely exfoliated during the sampling and handling processes. In the latter case, the electron-dense layer(s) on the mesoglea surface might originally underlie the epidermis.


Assuntos
Cubomedusas/ultraestrutura , Hidrozoários/ultraestrutura , Cifozoários/ultraestrutura , Animais , Simulação por Computador , Luz , Modelos Biológicos
4.
Biomed Res Int ; 2021: 8855248, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33748281

RESUMO

Neurodegenerative diseases are one of the major causes of death worldwide, characterized by neurite atrophy, neuron apoptosis, and synapse loss. No effective treatment has been indicated for such diseases so far, and the search for new drugs is being increased in the last years. Animal venoms' secretion/venom can be an alternative for the discovery of new molecules, which could be the prototype for a new treatment. Here, we present the biochemical characterization and activity of the extract from the box jellyfish Chiropsalmus quadrumanus (Cq) on neurites. The Cq methanolic extract was obtained and incubated to human SH-SY5Y neurons, and neurite parameters were evaluated. The extract was tested in other cell types to check its cytotoxicity and was submitted to biochemical analysis by mass spectrometry in order to check its composition. We could verify that the Cq extract increased neurite outgrowth length and branching junctions, amplifying the contact between SH-SY5Y neurons, without affecting cell body and viability. The extract action was selective for neurons, as it did not cause any effects on other cell types, such as tumor line, nontumor line, and red blood cells. Moreover, mass spectrometry analysis revealed that there are no proteins but several low molecular mass compounds and peptides. Three peptides, characterized as cryptides, and 14 low molecular mass compounds were found to be related to cytoskeleton reorganization, cell membrane expansion, and antioxidant/neuroprotective activity, which act together to increase neuritogenesis. After this evaluation, we conclude that the Cq extract is a promising tool for neuronal connection recovery, an essential condition for the treatment of neurodegenerative diseases.


Assuntos
Misturas Complexas/farmacologia , Cubomedusas/química , Neuritos/metabolismo , Fármacos Neuroprotetores/farmacologia , Animais , Linhagem Celular Tumoral , Misturas Complexas/química , Humanos , Fármacos Neuroprotetores/química
5.
Mar Environ Res ; 162: 105175, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33070064

RESUMO

Deoxygenation and acidification co-occur in many coastal ecosystems because nutrient enrichment produces excess organic matter that intensifies aerobic respiration during decomposition, thereby depleting O2, increasing CO2 and lowering pH. Despite this link between coastal deoxygenation (CD) and acidification (CA), and evidence that both stressors pose a risk to marine fauna, few studies have examined the effects of these drivers in combination on marine animals including invertebrates. Here, we studied the individual and combined effects of CD (~1.5 mg L-1 O2) and CA (~7.7 pH) on the survival, number of tentacles, settlement and movement behaviours of creeping polyps of the Irukandji jellyfish, Alatina alata. Low DO increased the survival rate (17% more) of the creeping polyps. 12% more creeping polyps settled in low pH than ambient pH and 16.7% more settled in low DO than ambient DO treatment. Exposure to CA and CD did not influence the number of tentacles, mobility or movement velocity of the creeping polyps, but after 4 h exposure to the treatments, they moved approximately half as fast. Our results indicate that CD can enhance survival and settlement success, but CA does not intensify these outcomes on A. alata creeping polyps.


Assuntos
Cnidários , Cubomedusas , Animais , Ecossistema , Concentração de Íons de Hidrogênio , Cifozoários
6.
PLoS One ; 15(10): e0241410, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33119724

RESUMO

Biological investigations on free ranging marine species are regarded as challenging throughout the scientific community. This is particularly true for 'logistically difficult species' where their cryptic natures, low abundance, patchy distributions and difficult and/or dangerous sampling environments, make traditional surveys near impossible. What results is a lack of ecological knowledge on such marine species. However, advances in UAV technology holds potential for overcoming these logistical difficulties and filling this knowledge gap. Our research focused on one such logistically difficult species, the Australian box Jellyfish (Chironex fleckeri), and we investigated the capacity of consumer grade UAV technology to detect this, highly venomous, target species in the inshore waters of Northern Queensland Australia. At two sites in the Weipa area, we utilized video analysis, visual count comparisons with a netted animal tally, and evaluated the role of associated environmental conditions, such as wind speed, water visibility and cloud cover on jellyfish detection rates. In total fifteen, 70 meter transects were completed between two sites, with 107 individuals captured. Drone success varied between the two sites with a significant difference between field and post-field (laboratory) counts. Animal size and cloud cover also had significant effects on detection rates with an increase in cloud cover and animal size enhancing detection probability. This study provides evidence to suggest drone surveys overcome obstacles that traditional surveys can't, with respect to species deemed logistically difficult and open scope for further ecological investigations on such species.


Assuntos
Cubomedusas , Monitoramento Ambiental/instrumentação , Inquéritos e Questionários , Animais , Tamanho Corporal , Cubomedusas/anatomia & histologia , Dinâmica Populacional
7.
Int Marit Health ; 71(2): 91-96, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32604451

RESUMO

BACKGROUND: Irukandji syndrome definition is still widely misunderstood. Irukandji-like syndrome is more unclear than Irukandji syndrome. This study aimed to describe Irukandji-like syndrome in cases involving stinging by single-tentacle box jellyfish species in Thailand. MATERIALS AND METHODS: Surveillance system and networks of toxic jellyfish incidents were established to enable case detection. In the period 2007 to 2019, all cases of stinging by single-tentacle box jellyfish resulting in collapse, hospital attendance or death were investigated. RESULTS: The majority of the 19 Irukandji-like syndrome cases were male (68.2%), median age 35.0 years (range 6.0-60.0), and Thai nationality (52.3%). Clinical manifestations of Irukandji-like syndrome were categorised as severe wound pain with immediate systemic reaction (66.7%), moderate wound pain with gradual systemic reaction (16.7%), and moderate wound pain with the immediate systemic reaction after a physical/chemical trigger (16.7%). The pain occurring when being stung differed from the pain occurring during the systemic reaction. The five most common symptoms were pain (100.0%), high blood pressure (100.0%), palpitations (86.7%), respiratory distress (52.6%), and near collapse/collapse (31.6%). The pain occurs when being stung was excruciating or burning pain at the wounds, felt like an electric shock, and rapidly expanded to heart pain. While the pain occurring during the systemic reaction was back pain, muscle pain, joint pain, abdominal pain, and body aches. The marks from the tentacles appeared similar in appearance to the caterpillar tracks of tanks. In 6 cases the species could be identified and all of them involving the Morbakka spp. CONCLUSIONS: This was the largest study of Irukandji-like syndrome cases involving stings by single-tentacle box jellyfish in Thailand and the different clinical manifestations might be caused by different species of single-tentacle box jellyfish.


Assuntos
Mordeduras e Picadas/epidemiologia , Venenos de Cnidários/envenenamento , Cubomedusas/patogenicidade , Adolescente , Adulto , Animais , Mordeduras e Picadas/mortalidade , Mordeduras e Picadas/patologia , Criança , Feminino , Humanos , Hipertensão/etiologia , Masculino , Pessoa de Meia-Idade , Dor/etiologia , Síndrome , Tailândia/epidemiologia
8.
Toxicon ; 185: 15-25, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32615183

RESUMO

Both Chironex fleckeri venom (CFV) and Carukia barnesi venoms (CBV) are known to cause significant cardiac morbidity and mortality. Many animal studies have demonstrated cardiac dysfunction with these venoms. This study specifically examines the systolic and diastolic cardiac functions using non-invasive pulse wave doppler. Mitral and aortic doppler sonograms of anaesthetised mice were obtained utilising a 10 MHz doppler probe. These continuous sonograms were analysed to ascertain changes in cardiac function before and after the parenteral administration of the test venoms. We found that CFV administration causes rapid cardiac dysfunction without a change in heart rate. Analysis of the resulting sonograms shows both systolic and diastolic dysfunction which together is suggestive of a progressively poorly compliant, contracted left ventricle. Additionally, the rapidity of cardiac dysfunction suggests a direct effect of CFV on myocardial cells. In contrast CBV showed a moderate immediate inotropic and chronotropic effect that was sustained until precipitous cardiac decompensation. This is consistent with the hypotheses of a toxin induced stress cardiomyopathy from sustained catecholaminergic activity.


Assuntos
Venenos de Cnidários/toxicidade , Cubomedusas/fisiologia , Animais , Insuficiência Cardíaca , Camundongos , Miócitos Cardíacos
9.
Hawaii J Health Soc Welf ; 79(5 Suppl 1): 135-138, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32490401

RESUMO

This is a case report of chronic esophagitis and gastritis following the ingestion of box jellyfish (Alatina alata) by a 12-year old boy with severe autism spectrum disorder and pica. Biopsies taken at esophagogastroduodenoscopy at two months post ingestion revealed histological evidence of esophagitis and gastritis, which resolved after treatment with H2 receptor agonist and proton pump inhibitor.


Assuntos
Cubomedusas/patogenicidade , Ingestão de Alimentos/fisiologia , Esofagite/etiologia , Gastrite/etiologia , Animais , Transtorno do Espectro Autista/complicações , Transtorno do Espectro Autista/psicologia , Criança , Cubomedusas/microbiologia , Endoscopia do Sistema Digestório/métodos , Esofagite/patologia , Gastrite/patologia , Hawaii , Humanos , Masculino , Pica/complicações , Pica/psicologia
10.
PLoS One ; 15(6): e0230768, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32555581

RESUMO

Relationships between environmental factors and oscillations in jellyfish abundance, especially in the early life stages, could help to interpret past increases and also predict scenarios in a changing future. For the first time, we present cubozoan spatial and temporal distributions in the earliest stages and their relationships with different factors. Abundances of Carybdea marsupialis medusae showed high interannual variability from 2008 to 2014 along the Dénia coast (SE Spain, W Mediterranean). During 2015, samples were collected from 11 beaches along 17 km of coastline, 8 times from January to November in order to determine the effects of environmental factors on the distribution of juvenile C. marsupialis. Juveniles (≤ 15 mm diagonal bell width) were present from May to July, with more sampled near shore (0-15 m). Most of them occurred in June when their numbers were unequal among beaches (average 0.05 ind m-3, maximum 6.71 ind m-3). We tested distributions of juveniles over time and space versus temperature, salinity, nutrients (N, P and Si), chlorophyll-a (Chl-a), and zooplankton abundance. Temperature and cladocerans (zooplankton group) were significantly positively correlated with juvenile distribution, whereas Chl-a concentration was weakly negative. By contrast, in 2014, high productivity areas (Chl-a and zooplankton) overlapped the maximum adult abundance (5.2 ind m-3). The distribution of juveniles during 2015 did not spatially coincide with the areas where ripe adults were located the previous year, suggesting that juveniles drift with the currents upon release from the cubopolyps. Our results yield important insights into the complexity of cubozoan distributions.


Assuntos
Cubomedusas , Meio Ambiente , Animais , Região do Mediterrâneo , Análise Espaço-Temporal
11.
Toxicon ; 184: 94-98, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32533959

RESUMO

The emergence of novel venom extraction techniques over the last half-century has greatly facilitated advances in the field of cnidarian research. A new recovery protocol utilizing ethanol as the primary stimulant in nematocyst discharge was recently published, however in vitro examination of the venom on organic models was not performed. This present study reports an original comparison of the chemically-induced discharge technique in vitro with a commonly used saltwater extraction method. Size-exclusion chromatography revealed distinct differences in venom profiles between the two methods: the saltwater recovery method FPLC profile and SDS-PAGE gel were similar to previously published results, whereas the ethanol-induced method was not. SDS-PAGE gel revealed distinct 40-55 kDa bands of previously identified cardiotoxic proteins recovered from the saltwater method, whereas the ethanol-induced method yielded degraded venom protein bands. A concentration-response curve generated through xCELLigence Real-Time Cell Analysis (RTCA) revealed a dramatic decrease in human cardiomyocyte activity when venom recovered via saltwater discharge was applied to these cells. With the exception of one sample, all ethanol-induced recovered venom failed to prompt a concentration-dependent decrease in cell survival when applied to human cardiomyocytes, resulting in a significant difference in IC50 concentrations between the compared venom samples. The data presented here facilitates an improved understanding of the parameters and analyses that are essential when developing and utilizing novel techniques for future cnidarian venom extraction research and supports the conclusion that recovery of venom from the tentacles of the box jellyfish Chironex fleckeri by ethanol is not an effective, efficient, or comprehensive extraction method compared to the published method of saltwater degradation of tentacles and bead mill extraction.


Assuntos
Venenos de Cnidários/análise , Cubomedusas , Animais , Sobrevivência Celular , Cromatografia em Gel , Eletroforese em Gel de Poliacrilamida , Miócitos Cardíacos , Nematocisto
12.
Molecules ; 25(4)2020 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-32079282

RESUMO

Cubozoan nematocyst venoms contain known cytolytic and hemolytic proteins, but small molecule components have not been previously reported from cubozoan venom. We screened nematocyst extracts of Alatina alata and Chironex yamaguchii by LC-MS for the presence of small molecule metabolites. Three isomeric compounds, cnidarins 4A (1), 4B (2), and 4C (3), were isolated from venom extracts and characterized by NMR and MS, which revealed their planar structure as cyclic γ-linked tetraglutamic acids. The full configurational assignments were established by syntheses of all six possible stereoisomers, comparison of spectral data and optical rotations, and stereochemical analysis of derivatized degradation products. Compounds 1-3 were subsequently detected by LC-MS in tissues of eight other cnidarian species. The most abundant of these compounds, cnidarin 4A (1), showed no mammalian cell toxicity or hemolytic activity, which may suggest a role for these cyclic tetraglutamates in nematocyst discharge.


Assuntos
Cubomedusas/química , Ácido Glutâmico/biossíntese , Ácido Glutâmico/isolamento & purificação , Animais , Organismos Aquáticos/química , Morte Celular/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Cromatografia de Fase Reversa , Venenos de Cnidários/química , Venenos de Cnidários/toxicidade , Ácido Glutâmico/química , Células HEK293 , Hemólise/efeitos dos fármacos , Humanos , Espectroscopia de Prótons por Ressonância Magnética , Distribuição Tecidual
13.
Toxins (Basel) ; 13(1)2020 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-33383955

RESUMO

Carukia barnesi was the first in an expanding list of cubozoan jellyfish whose sting was identified as causing Irukandji syndrome. Nematocysts present on both the bell and tentacles are known to produce localised stings, though their individual roles in Irukandji syndrome have remained speculative. This research examines differences through venom profiling and pulse wave Doppler in a murine model. The latter demonstrates marked measurable differences in cardiac parameters. The venom from tentacles (CBVt) resulted in cardiac decompensation and death in all mice at a mean of 40 min (95% CL: ± 11 min), whereas the venom from the bell (CBVb) did not produce any cardiac dysfunction nor death in mice at 60 min post-exposure. This difference is pronounced, and we propose that bell exposure is unlikely to be causative in severe Irukandji syndrome. To date, all previously published cubozoan venom research utilised parenterally administered venom in their animal models, with many acknowledging their questionable applicability to real-world envenomation. Our model used live cubozoans on anaesthetised mice to simulate normal envenomation mechanics and actual expressed venoms. Consequently, we provide validity to the parenteral methodology used by previous cubozoan venom research.


Assuntos
Mordeduras e Picadas , Venenos de Cnidários/toxicidade , Cubomedusas/fisiologia , Cardiopatias/induzido quimicamente , Animais , Feminino , Cardiopatias/mortalidade , Humanos , Camundongos , Camundongos Endogâmicos BALB C
14.
Artigo em Inglês | MEDLINE | ID: mdl-33396697

RESUMO

Box jellyfish are extremely potent venom-producing marine organisms. While they have been found worldwide, the highest health burden has been anticipated to be the tropical Indo-Pacific of Southeast Asia (SEA). At least 12 Cubozoan species have now been documented in Thai waters, and many of them inflict acutely lethal strings, especially those under the order Chirodropida. Our previous study has successfully differentiated species of box jellyfish using DNA sequencing to support the morphological study. In this study, we specifically designed polymerase chain reaction (PCR) primers for the 16S ribosomal RNA (rRNA) gene and the mitochondrial DNA cytochrome oxidase subunit I (COI) gene of lethal Thai Chironex species. The SYBR green-based real-time PCR panel was performed for rapid species identification. The sensitivity and specificity of the panel were determined by testing samples of different species. Moreover, we applied the panel to the tentacle sample from a real patient, which helped confirm the animal-of-cause of envenomation. Our results show a success for species identification of box jellyfish using 16S rRNA and COI PCR panel, which revealed congruence between molecular and morphological identification. Furthermore, the panel worked very well with the unknown samples and jellyfish tissue from the real envenomation case. The results demonstrated that molecular panels were able to identify three species of Chironex box jellyfish both rapidly and accurately, and can be performed without having a complete specimen or morphological study.


Assuntos
Cubomedusas , Animais , Cubomedusas/classificação , Cubomedusas/genética , DNA Mitocondrial/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Humanos , Reação em Cadeia da Polimerase , RNA Ribossômico 16S/genética , Especificidade da Espécie , Tailândia
15.
Zootaxa ; 4608(3): zootaxa.4608.3.13, 2019 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-31717142

RESUMO

In a revision of the generic classification of the tanagers, Burns et al. (2016) proposed the name Islerothraupis with type species Tanagra cristata Linnaeus, 1766 (long known as Tachyphonus cristatus); however, they overlooked a previous designation of that species as the type of a genus. In 1821, Feliks Pawel Jarocki, in the second volume of Zoologiia czyli Zwiérzetopismo Ogólne podlug Naynowszego Systematu ulozone ("Zoology, or general natural history account according to the newest arranged system"), page 133, specified Tanagra cristata as the type of a proposed subgenus Loriotus. The original text in Polish is available at the website www.rcin.org.pl, the Digital Repository of Scientific Institutes, which has made a wide diversity of scholarship in Polish available over the Internet. The original description of Loriotus, in parallel with other names Jarocki introduced in his Zoologiia, is minimal: "Dziób ostro konczysty, cokolwiek zgiety. Zuchwy sczeki spodniey przy nasadzie bardzo malo zgrubiale." (Bill ending in a point, somewhat curved. Lower mandible slightly thickened at base.).


Assuntos
Cubomedusas , Passeriformes , Animais , Internet , Mandíbula , Zoologia
16.
Wilderness Environ Med ; 30(3): 310-320, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31477508

RESUMO

This case report describes the typical features of the dermatological progression of a patient stung by a (probable) box jellyfish. The purpose is to guide clinicians and patients to an understanding of what to expect after such a sting using the clinical narrative and unique sequential photographs of the injury. With knowledgeable consultation from experienced physicians and meticulous care, this envenomation healed without the need for skin grafting.


Assuntos
Mordeduras e Picadas/complicações , Mordeduras e Picadas/tratamento farmacológico , Cubomedusas , Dermatopatias/terapia , Pele/patologia , Adulto , Animais , Mordeduras e Picadas/terapia , Camboja , Humanos , Pele/fisiopatologia , Dermatopatias/tratamento farmacológico , Dermatopatias/etiologia , Resultado do Tratamento , Adulto Jovem
17.
Mar Drugs ; 17(8)2019 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-31409009

RESUMO

Formulas derived from theoretical physics provide important insights about the nematocyst discharge process of Cnidaria (Hydra, jellyfishes, box-jellyfishes and sea-anemones). Our model description of the fastest process in living nature raises and answers questions related to the material properties of the cell- and tubule-walls of nematocysts including their polysialic acid (polySia) dependent target function. Since a number of tumor-cells, especially brain-tumor cells such as neuroblastoma tissues carry the polysaccharide chain polySia in similar concentration as fish eggs or fish skin, it makes sense to use these findings for new diagnostic and therapeutic approaches in the field of nanomedicine. Therefore, the nematocyst discharge process can be considered as a bionic blue-print for future nanomedical devices in cancer diagnostics and therapies. This approach is promising because the physical background of this process can be described in a sufficient way with formulas presented here. Additionally, we discuss biophysical and biochemical experiments which will allow us to define proper boundary conditions in order to support our theoretical model approach. PolySia glycans occur in a similar density on malignant tumor cells than on the cell surfaces of Cnidarian predators and preys. The knowledge of the polySia-dependent initiation of the nematocyst discharge process in an intact nematocyte is an essential prerequisite regarding the further development of target-directed nanomedical devices for diagnostic and therapeutic purposes. The theoretical description as well as the computationally and experimentally derived results about the biophysical and biochemical parameters can contribute to a proper design of anti-tumor drug ejecting vessels which use a stylet-tubule system. Especially, the role of nematogalectins is of interest because these bridging proteins contribute as well as special collagen fibers to the elastic band properties. The basic concepts of the nematocyst discharge process inside the tubule cell walls of nematocysts were studied in jellyfishes and in Hydra which are ideal model organisms. Hydra has already been chosen by Alan Turing in order to figure out how the chemical basis of morphogenesis can be described in a fundamental way. This encouraged us to discuss the action of nematocysts in relation to morphological aspects and material requirements. Using these insights, it is now possible to discuss natural and artificial nematocyst-like vessels with optimized properties for a diagnostic and therapeutic use, e.g., in neurooncology. We show here that crucial physical parameters such as pressure thresholds and elasticity properties during the nematocyst discharge process can be described in a consistent and satisfactory way with an impact on the construction of new nanomedical devices.


Assuntos
Cnidários/química , Ácido N-Acetilneuramínico/química , Nematocisto/química , Animais , Parede Celular/química , Cubomedusas/química , Elasticidade/efeitos dos fármacos , Humanos , Hydra/química , Morfogênese/efeitos dos fármacos , Nanomedicina/métodos
18.
J Morphol ; 280(10): 1530-1536, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31334880

RESUMO

Cubozoans have a complex lifecycle in many ways similar to the scyphozoan lifecycle. The sexual reproduction within cubozoans varies between species with one clade having copulation and internal fertilization and the release of planula larvae. This cubozoan clade, the family Tripedaliidae, includes three species, Copula sivickisi, Tripedalia cystophora, and Tripedalia binata. In a recent study, it was suggested that in C. sivickisi cnidocytes play a new and important role during the sexual reproduction. Male derived cnidocytes anchor sperm packages to the female gonads and female derived cnidocytes protect the externalized embryo strand. Here, we have examined the gonads and gametes of T. cystophora and our results reveal that the male produced spermatozeugmata have a high number of isorhiza type cnidocytes, which are transferred along with the sperm during copulation. This adds further support to our hypothesis that they are important for sperm anchorage. The female gonads are lacking cnidocytes all together showing that cnidocyte production is not just a default state of the epithelium in these animals.


Assuntos
Cubomedusas/citologia , Gônadas/citologia , Animais , Cubomedusas/fisiologia , Feminino , Masculino , Reprodução
19.
Sci Total Environ ; 685: 471-479, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31176232

RESUMO

Ocean acidification and warming, fueled by excess atmospheric carbon dioxide, can impose stress on marine organisms. Most studies testing the effects of climate change on marine organisms, however, use extreme climate projection scenarios, despite moderate projections scenarios being most likely to occur. Here, we examined the interactive effects of warming and acidification on reproduction, respiration, mobility and metabolic composition of polyps of the Irukandji jellyfish, Carukia barnesi, to determine the responses of a cubozoan jellyfish to moderate and extreme climate scenarios in Queensland, Australia. The experiment consisted two orthogonal factors: temperature (current 25 °C and future 28 °C) and pH (current (8.0) moderate (7.9) and extreme (7.7)). All polyps survived in the experiment but fewer polyps were produced in the pH 7.7 treatment compared to pH 7.9 and pH 8.0. Respiration rates were elevated in the lowest pH treatment throughout most of the experiment and polyps were approximately half as mobile in this treatment compared to pH 7.9 and pH 8.0, regardless of temperature. We identified metabolites occurring at significantly lower relative abundance in the lowest pH (i.e. glutamate, acetate, betaine, methylguanidine, lysine, sarcosine, glycine) and elevated temperature (i.e. proline, trigonelline, creatinine, mannose, acetate, betaine, methylguanidine, lysine, sarcosine) treatments. Glycine was the only metabolite exhibiting an interactive effect between pH and temperature. Our results suggest that C. barnesi polyps are unaffected by the most optimistic climate scenario and may tolerate even extreme climate conditions to some extent.


Assuntos
Mudança Climática , Cubomedusas/fisiologia , Ecossistema , Animais , Austrália , Monitoramento Ambiental , Água do Mar/química
20.
Nat Commun ; 10(1): 1655, 2019 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-31040274

RESUMO

The box jellyfish Chironex fleckeri is extremely venomous, and envenoming causes tissue necrosis, extreme pain and death within minutes after severe exposure. Despite rapid and potent venom action, basic mechanistic insight is lacking. Here we perform molecular dissection of a jellyfish venom-induced cell death pathway by screening for host components required for venom exposure-induced cell death using genome-scale lenti-CRISPR mutagenesis. We identify the peripheral membrane protein ATP2B1, a calcium transporting ATPase, as one host factor required for venom cytotoxicity. Targeting ATP2B1 prevents venom action and confers long lasting protection. Informatics analysis of host genes required for venom cytotoxicity reveal pathways not previously implicated in cell death. We also discover a venom antidote that functions up to 15 minutes after exposure and suppresses tissue necrosis and pain in mice. These results highlight the power of whole genome CRISPR screening to investigate venom mechanisms of action and to rapidly identify new medicines.


Assuntos
Antídotos/toxicidade , Venenos de Cnidários/toxicidade , Animais , Western Blotting , Cálcio/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Cubomedusas , Células do Cúmulo , Ontologia Genética , Masculino , Camundongos , Necrose/induzido quimicamente , Esfingomielinas/metabolismo
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