Xenon treatment after severe traumatic brain injury improves locomotor outcome, reduces acute neuronal loss and enhances early beneficial neuroinflammation: a randomized, blinded, controlled animal study.

BACKGROUND: Traumatic brain injury (TBI) is a major cause of morbidity and mortality, but there are no clinically proven treatments that specifically target neuronal loss and secondary injury development following TBI. In this study, we evaluate the effect of xenon treatment on functional outcome, lesion volume, neuronal loss and neuroinflammation after severe TBI in rats. METHODS: Young adult male Sprague Dawley rats were subjected to controlled cortical impact (CCI) brain trauma or sham surgery followed by treatment with either 50% xenon:25% oxygen balance nitrogen, or control gas 75% nitrogen:25% oxygen. Locomotor function was assessed using Catwalk-XT automated gait analysis at baseline and 24 h after injury. Histological outcomes were assessed following perfusion fixation at 15 min or 24 h after injury or sham procedure. RESULTS: Xenon treatment reduced lesion volume, reduced early locomotor deficits, and attenuated neuronal loss in clinically relevant cortical and subcortical areas. Xenon treatment resulted in significant increases in Iba1-positive microglia and GFAP-positive reactive astrocytes that was associated with neuronal preservation. CONCLUSIONS: Our findings demonstrate that xenon improves functional outcome and reduces neuronal loss after brain trauma in rats. Neuronal preservation was associated with a xenon-induced enhancement of microglial cell numbers and astrocyte activation, consistent with a role for early beneficial neuroinflammation in xenon's neuroprotective effect. These findings suggest that xenon may be a first-line clinical treatment for brain trauma.

Xenon improves long-term cognitive function, reduces neuronal loss and chronic neuroinflammation, and improves survival after traumatic brain injury in mice.

BACKGROUND: Xenon is a noble gas with neuroprotective properties that can improve short and long-term outcomes in young adult mice after controlled cortical impact. This follow-up study investigates the effects of xenon on very long-term outcomes and survival. METHODS: C57BL/6N young adult male mice (n=72) received single controlled cortical impact or sham surgery and were treated with either xenon (75% Xe:25% O2) or control gas (75% N2:25% O2). Outcomes measured were: (i) 24 h lesion volume and neurological outcome score; (ii) contextual fear conditioning at 2 weeks and 20 months; (iii) corpus callosum white matter quantification; (iv) immunohistological assessment of neuroinflammation and neuronal loss; and (v) long-term survival. RESULTS: Xenon treatment significantly reduced secondary injury (P<0.05), improved short-term vestibulomotor function (P<0.01), and prevented development of very late-onset traumatic brain injury (TBI)-related memory deficits. Xenon treatment reduced white matter loss in the contralateral corpus callosum and neuronal loss in the contralateral hippocampal CA1 and dentate gyrus areas at 20 months. Xenon's long-term neuroprotective effects were associated with a significant (P<0.05) reduction in neuroinflammation in multiple brain areas involved in associative memory, including reduction in reactive astrogliosis and microglial cell proliferation. Survival was improved significantly (P<0.05) in xenon-treated animals compared with untreated animals up to 12 months after injury. CONCLUSIONS: Xenon treatment after TBI results in very long-term improvements in clinically relevant outcomes and survival. Our findings support the idea that xenon treatment shortly after TBI may have long-term benefits in the treatment of brain trauma patients.

Phylogenetic relationships within Dicrocoeliidae (Platyhelminthes: Digenea) from birds from the Czech Republic using partial 28S rDNA sequences.

Partial (D1-D3) 28S rRNA gene sequences from 16 isolates of digenean parasites of the family Dicrocoeliidae recovered from 16 bird species from the Czech Republic were used for phylogenetic reconstruction. Comparison with sequences available from GenBank suggests that the genus Brachylecithum is paraphyletic, requiring further validation and possible systematic revision. Although partial 28S rDNA is relatively conserved, analyses suggest that the following taxa are synonymous: Lutztrema attenuatum = L. monenteron = L. microstomum, Brachylecithum lobatum = B. glareoli. Zonorchis petiolatus is reassigned back to the genus Lyperosomum with L. collurionis as a junior synonym. The study revealed how complicated the systematics of the family Dicrocoeliidae is currently. The morphology of the group is variable, and the current distinguishing characters at species and even generic level are not sufficiently distinctive; it is difficult to identify the specimens correctly and identification of GenBank isolates is not reliable. Extensive sampling of isolates for both molecular and morphological studies is necessary to resolve the relationships within the family.

Historical analysis of the type species of the genus Trichobilharzia Skrjabin et Zakharov, 1920 (Platyhelminthes: Schistosomatidae).

Trichobilharzia Skrjabin & Zakharov, 1920 is known as the most species-rich genus of the blood fluke family Schistosomatidae. To date, more than 40 species have been described, even though validity of some of them is questionable (Horák et al. 2002). Members of the genus use various birds as final hosts, but they attract attention mostly as causative agents of hypersensitive skin reaction (cercarial dermatitis or swimmer's itch) in mammals including humans. As this is one of the.

Schistosomes in South African penguins.

During the years 2009-2012, faeces of African penguins (Spheniscus demersus L.) from South African rehabilitation centres were examined for helminths. In total, 46 out 555 samples (8.29 %), mostly belonging to adult birds, were found to contain oval schistosome eggs with a spine on one pole. Their dimensions were 153.21 ± 9.07 × 87.14 ± 8.67 µm. Selected DNA fragments (18S, 28S and ITS rDNA) were sequenced and compared to other schistosome isolates deposited in GenBank. The shape of the eggs suggests that they belong to the genus Gigantobilharzia; however, due to the insufficient stage of knowledge of the genus and limited number of species available for comparison, we were not able to assign the isolate unambiguously to this genus based on either the egg morphology or the results of molecular analysis.

Gigantobilharzia melanoidis n.sp. (Trematoda: Schistosomatidae) from Melanoides tuberculata (Gastropoda: Thiaridae) in the United Arab Emirates.

Delicate filamentous schistosomatids detected in the intestinal veins of experimentally infected chickens are here described as a new parasite species, Gigantobilharzia melanoidis, and details of its life cycle are given. It is the first complete description of a schistosome species that uses Melanoides tuberculata as an intermediate host. Apharyngeate ocellate brevifurcate cercariae found in 65 out of 950 M. tuberculata collected in a pond in Al Aweer, United Arab Emirates were used as infection material. The new species can be distinguished from the other species of the genus by the following combination of characters: caecal reunion in males situated anterior to seminal vesicle, a very short gynecophoric canal (gynecophoric canal length/body length ratio lower than 0.05) supported by 12-14 thickened bands. Cercariae of G. melanoidis can be distinguished from other Gigantobilharzia cercariae described in the literature based on the combination of these characters: flame cell formula 2[3 + 3 + (1)] = 14 and relatively longer tail stem in relation to body (tail stem length/body length ratio = 2). Under laboratory conditions at a temperature between 24 and 26 °C, M. tuberculata started to shed cercariae 7 weeks after exposure to miracidia. The prepatent period of G. melanoidis in experimentally infected chicken lasted between 43 and 49 days. The parasite inhabits the blood vessels mainly of the small intestine. Sections of adult worms and eggs were also found in histocuts of parenchymatous organs. Results of phylogenetic analysis corroborated that G. melanoidis is a distinct species; however, they also confirmed that the genus Gigantobilharzia is in need of revision and in future might be split into several genera.

Renal trematode infection due to Paratanaisia bragai in zoo housed Columbiformes and a red bird-of-paradise (Paradisaea rubra).

Trematode infections affect a diverse range of avian species and the organs that are parasitised are also very varied. The family Eucotylidae contains seven genera of renal flukes that parasitise various birds. In birds, mild to severe lesions have been reported for species of the genus Paratanaisia, which was originally described from columbiform and galliform specimens collected in South America and has been identified in a number of wild avian species. This paper investigates eight cases of renal trematode infection at Chester Zoo in the UK due to Paratanaisia bragai in five previously unreported species: red bird-of-paradise, Socorro dove, Mindanao bleeding heart dove, laughing dove and emerald dove. Pathological changes, which varied between species, are discussed. A known intermediate snail host Allopeas clavulinum was present in the enclosures but there was no direct evidence of trematode infection. The size of the snails, possible low prevalence and the difficulty of visualising sporocysts contributed to this. Thus the development and application of further molecular diagnostic markers that can be applied to snail tissues is warranted. Parasite identification was confirmed utilizing DNA amplification from formalin-fixed paraffin-embedded tissues using PCR and trematode specific primers. Sequencing full ssrDNA and D1-D3 lsrDNA confirmed the identity in all cases as P. bragai. However, the short 310 bp fragment used provides insufficient variation or sequence length for wider application. The epidemiology, pathology and consequences for the management of these endangered species are discussed. Preliminary work on developing an effective ante mortem diagnostic PCR test kit is also highlighted.

Orientobilharzia Dutt & Srivastava, 1955 (Trematoda: Schistosomatidae), a junior synonym of Schistosoma Weinland, 1858.

In the last few decades, phylogenetic studies of the family Schistosomatidae based on molecular markers have revealed that members of the genus Orientobilharzia Dutt & Srivastava, 1955 belong within Schistosoma Weinland, 1858. In this study, the original descriptions and redescriptions of Orientobilharzia species and related revisions are reviewed, and it is confirmed that the morphological characters correspond with the results of the molecular studies. The two genera differ only in the number of testes; however, this character varies to a large extent within particular genera of the subfamily Schistosomatinae and cannot be used to justify the separation of Orientobilharzia from Schistosoma. Also, we have verified claims suggesting the synonymy of certain species of Orientobilharzia; the four valid species of this genus are transferred to Schistosoma and two new synonymies are formally presented. The following nomenclatural changes are made: Schistosoma Weinland, 1858 [syn. Orientobilharzia Dutt & Srivastava, 1955 (syn. nov.)]; Schistosoma bomfordi Montgomery, 1906 (comb. restit.); S. turkestanicum Skrjabin, 1913 (comb. restit.) [syns Ori. turkestanica var. tuberculata (Bhalerao, 1932) (syn. nov.) and Ori. cheni Hsü & Yang, 1957 (syn. nov.)]; S. dattai (Dutt & Srivastava, 1952) n. comb.; and S. harinasutai (Kruatrachue, Bhaibulaya & Harinasuta, 1965) n. comb. The generic diagnosis of Schistosoma is amended and a revised key to the subfamily Schistosomatinae Stiles & Hassall, 1898 is presented.

Bird schistosomes in planorbid snails in the Czech Republic.

Bird schistosomes have been in focus as causative agents of cercarial dermatitis of humans in the last years; however, our knowledge of their species spectrum and intermediate host specificity is still insufficient. Our study focused on bird schistosomes developing in planorbid snails that have been less studied so far. From 2001 to 2010, cercariae of bird schistosomes were found in four snail species (Gyraulus albus, Segmentina nitida, Anisus vortex and Planorbis planorbis) from seven localities in the Czech Republic. Based on morphology and results of molecular analysis, the isolates found belong to at least six species. Five of them are probably undescribed species, and one species appears to be identical with Gigantobilharzia vittensis Reimer, 1963 (syn. G. suebica Dönges, 1964). The finding from S. nitida represents the first report of a bird schistosome from this snail.

Parasitological and molecular study of the furcocercariae from Melanoides tuberculata as a probable agent of cercarial dermatitis.

Cercarial dermatitis is caused by animal schistosomes in many parts of the world including Iran. Various stages of the parasites have been studied in intermediate and definitive hosts in northern and southwestern Iran; however, no molecular investigation for species identification and classification of these agents has been carried out, so far. In the present study, more than 3,800 aquatic snails were collected from water sources of Khuzestan, southwest Iran. The snails were identified as Lymnaea gedrosiana, Radix auricularia, Melanoides tuberculata, Melanopsis sp. and Physa acuta. They were examined for schistosome cercariae. Two specimens of M. tuberculata were infected with ocellate furcocercariae belonging to the family Schistosomatidae. Molecular studies were carried on these schistosomatid samples. Both samples belong to an unknown schistosome species and genus in sister position to Gigantobilharzia-Dendritobilharzia clade. They differ from other species in their ITS sequence region as well as in their intermediate host specificity--This is one of the first reports on schistosome cercariae from M. tuberculata and the first including molecular data. Due to adaptability and invasiveness of this snail species, this new schistosome species, as a potential causative agent of cercarial dermatitis in humans, needs to be studied further.

Schistosomes in the north: a unique finding from a prosobranch snail using molecular tools.

Samples of schistosome cercariae from three different snail species (Lymnaea stagnalis, Radix auricularia and Valvata (Tropidina) macrostoma) collected from lakes in Central Finland were analyzed using molecular techniques. Based on sequences of ITS region of rDNA, the parasite isolates from L. stagnalis and R. auricularia belong to Trichobilharzia szidati and T. franki, respectively. This confirms a wide distribution of these two species in Europe. On the other hand, the isolates from V. macrostoma represent a unique finding--they belong to yet unknown schistosome species falling into the bird schistosome clade. Therefore, identification of natural final hosts and morphological characterization of particular developmental stages need to be performed in the future.