Morphology and molecules reveal the alien <Emphasis Type="Italic">Posthodiplostomum centrarchi</Emphasis> Hoffman, 1958 as the third species of <Emphasis Type="Italic">Posthodiplostomum</Emphasis> Dubois, 1936 (Digenea: Diplostomidae) in Europe

Metacercariae of two species of Posthodiplostomum Dubois, 1936 (Digenea: Diplostomidae) were subjected to morphological and molecular studies: P. brevicaudatum (von Nordmann, 1832) from Gasterosteus aculeatus (L.) (Gasterosteiformes: Gasterosteidae), Bulgaria (morphology, cox1 and ITS1-5.8S-ITS2) and Perca fluviatilis L. (Perciformes: Percidae), Czech Republic (morphology, cox1, ITS1-5.8S-ITS2 and 28S); and P. centrarchi Hoffman, 1958 from Lepomis gibbosus (L.) (Perciformes: Centrarchidae), Bulgaria (morphology, cox1 and ITS1-5.8S-ITS2) and Slovakia (cox1 and ITS1-5.8S-ITS2). In addition, cercariae of P. cuticola (von Nordmann, 1832) from Planorbis planorbis (L.) (Mollusca: Planorbidae), Lithuania (morphology and cox1) and metacercariae of Ornithodiplostomum scardinii (Schulman in Dubinin, 1952) from Scardinius erythrophthalmus (L.) (Cypriniformes: Cyprinidae), Czech Republic, were examined (morphology, cox1, ITS1-5.8S-ITS2 and 28S). These represent the first molecular data for species of Posthodiplostomum and Ornithodiplostomum Dubois, 1936 from the Palaearctic. Phylogenetic analyses based on cox1 and ITS1-5.8S-ITS2, using O. scardinii as the outgroup and including the three newly-sequenced Posthodiplostomum spp. from Europe and eight published unidentified (presumably species-level) lineages of Posthodiplostomum from Canada confirmed the distinct status of the three European species (contrary to the generally accepted opinion that only P. brevicaudatum and P. cuticola occur in the Palaearctic). The subspecies Posthodiplostomum minimum centrarchi Hoffmann, 1958, originally described from North America, is elevated to the species level as Posthodiplostomum centrarchi Hoffman, 1958. The undescribed “Posthodiplostomum sp. 3” of Locke et al. (2010) from centrarchid fishes in Canada has identical sequences with the European isolates of P. centrarchi and is recognised as belonging to the same species. The latter parasite, occurring in the alien pumpkinseed sunfish Lepomis gibbosus in Europe, is also supposed to be alien for this continent. It is speculated that it colonised Europe long ago and is currently widespread (recorded in Bulgaria, Slovakia and Spain); based on the cox1 sequence of an adult digenean isolate from the Ebro Delta, Spain, only the grey heron (Ardea cinerea L.) (Ciconiiformes: Ardeidae) is known to be its definitive host in Europe.     

Zinc content in the diet affects the activity of Cu/ZnSOD, lipid peroxidation and lipid profile of spontaneously hypertensive rats

The present study focused on the effect of Zn containing diets on the activity of superoxide dismutase (Cu/ZnSOD), systolic blood pressure (SBP), lipid peroxides (ROOH) and lipids (LDL, HDL, triglycerides and cholesterol) in male spontaneously hypertensive rats (SHR). Three experimental groups of animals were studied: a control (G1-40 mg), and two with zinc-supplemented diets (G2-100 and G3-160 mg Zn/kg lab chow). The diets were introduced at the beginning of the development of hypertension (2 months after birth) and the animals were fed for 8 weeks. The activity of CuZnSOD in erythrocytes was determined by spectrophotometry with the use of RANSOD kit (RANDOX Laboratories Ltd., UK). Atomic-absorption spectrometry was used to determine Zn and Cu concentrations in the rat's sera. A significantly increased Cu/ZnSOD activity was found in G3 compared with rats fed with control diet G1 (p = 0.020). SBP was significantly decreased in G3 in relation to G1 (p = 0.0048). The lipid hydroperoxide concentration was significantly decreased in G3 compared with G1 (p = 0.016) and G2 (p = 0.005). Zinc supplement affected lipids profile by decreasing LDL and increasing HDL. The present data suggest that Zn concentration in the diet plays an important role in the regulation of SBP and can be a critical nutrient for maintenance of anti-oxidative events in SHR.     

A quantitative approach to the evaluation of the morphological variability of two echinostomes, Echinostoma miyagawai Ishii, 1932 and E. revolutum (Frölich, 1802), from Europe

A comparative morphometric analysis was conducted on two European species of Echinostoma in order to examine the degree of the variability in the metrical characteristics of the adults and to assess their value in discriminating species. Adult E. miyagawai and E. revolutum, obtained experimentally, were compared using univariate and multivariate statistical analyses of 35 and 25 metrical characters, respectively. All subsets of worms of different ages represented homogeneous samples with respect to their morphometric characteristics; however, univariate analyses revealed significant differences in 22 and 23 variables between the corresponding age subsets of the two species, and it was found that the different allometric growth patterns contribute to this. The variables, body width at the posterior border of the ventral sucker, pharynx length and width, ovary length, testes length and width and length of the pre-ovarian region, exhibited isometric or positive allometric growth in E. miyagawai and negative allometry in E. revolutum. A cluster analysis based on 61 specimens and 25 variables separated E. revolutum and E. miyagawai unambiguously, producing an exact ordering of the specimens with respect to their identity and age. A forward stepwise discriminant analysis identified five variables (body width at the posterior border of ventral sucker, head collar width, length of oesophagus, width of ventral sucker and length of the pre-ovarian region) which yielded a 100% accurate classification of the two species. We suggest, therefore, that the morphometric characteristics of the adult worms should be used in studies attempting the identification of species or isolates of Echinostoma spp. More comparative data need to be gathered in order that the species boundaries within the revolutum group be defined more accurately.     

Microalgae Improve the Photosynthetic Performance of Rice Seedlings (<i>Oryza sativa</i> L.) under Physiological Conditions and Cadmium Stress

The aim of this study was to assess the impact of the microalgae Chlorella vulgaris on the rice seedlings at physiological conditions and under cadmium (Cd) stress. We examined the effects of C. vulgaris in the nutrient solution on rice seedlings grown hydroponically in the presence and the absence of 150 μM CdCl₂, using the low (77 K) temperature and pulse amplitude modulated (PAM) chlorophyll fluorescence, P700 photooxidation measurements, photochemical activities of both photosystems, kinetic parameters of oxygen evolution, oxidative stress markers (MDA, H₂O₂ and proline), pigment content, growth parameters and Cd accumulation. Data revealed that the application C. vulgaris not only stimulates growth and improves the functions of photosynthetic apparatus under physiological conditions, but also reduces the toxic effect of Cd on rice seedlings. Furthermore, the presence of the green microalgae in the nutrient solution of the rice seedlings during Cd exposure, significantly improved the growth, photochemical activities of both photosystems, the kinetic parameters of the oxygen-evolving reactions, pigment content and decreased lipid peroxidation, H₂O₂ and proline content. Data showed that the alleviation of Cd-induced effects in rice seedlings is a result of the Cd sorption by microalgae, as well as the reduced Cd accumulation in the roots and its translocation from the roots to the shoots.     

A common F-box gene regulates the leucine homeostasis of Medicago truncatula and Arabidopsis thaliana

The F-box domain is a conserved structural protein motif that most frequently interacts with the SKP1 protein, the core of the SCFs (SKP1-CULLIN-F-box protein ligase) E3 ubiquitin protein ligases. As part of the SCF complexes, the various F-box proteins recruit substrates for degradation through ubiquitination. In this study, we functionally characterized an F-box gene (MtF-box) identified earlier in a population of Tnt1 retrotransposon-tagged mutants of Medicago truncatula and its Arabidopsis thaliana homolog (AtF-box) using gain- and loss-of-function plants. We highlighted the importance of MtF-box in leaf development of M. truncatula. Protein–protein interaction analyses revealed the 2-isopropylmalate synthase (IPMS) protein as a common interactor partner of MtF-box and AtF-box, being a key enzyme in the biosynthesis pathway of the branched-chain amino acid leucine. For further detailed analysis, we focused on AtF-box and its role during the cell division cycle. Based on this work, we suggest a mechanism for the role of the studied F-box gene in regulation of leucine homeostasis, which is important for growth.

     

Presence of Rheumatoid Factor during Chronic HCV Infection Is Associated with Expansion of Mature Activated Memory B-Cells that Are Hypo-Responsive to B-Cell Receptor Stimulation and Persist during the Early Stage of IFN Free Therapy

Approximately half of those with chronic hepatitis C virus (HCV) infection have circulating rheumatoid factor (RF), and a portion of these individuals develop cryoglobulinemic vasculitis. B cell phenotype/function in relation to RF in serum has been unclear. We examined B cell subset distribution, activation state (CD86), cell cycle state (Ki67), and ex-vivo response to BCR, TLR9 and TLR7/8 stimulation, in chronic HCV-infected donors with or without RF, and uninfected donors. Mature-activated B-cells of HCV-infected donors had lower CD86 expression compared to uninfected donors, and in the presence of RF they also showed reduced CD86 expression in response to BCR and TLR9 stimulation. Additionally, mature activated memory B cells of HCV RF+ donors less commonly expressed Ki67⁺ than HCV RF- donors, and did not proliferate as well in response to BCR stimulation. Proportions of mature-activated B cells were enhanced, while naïve B-cells were lower in the peripheral blood of HCV-RF+ compared to RF- and uninfected donors. None of these parameters normalize by week 8 of IFN free direct acting antiviral (DAA) therapy in HCV RF+ donors, while in RF- donors, mature activated B cell proportions did normalize. These data indicate that while chronic HCV infection alone results in a lower state of activation in mature activated memory B cells, the presence of RF in serum is associated with a more pronounced state of unresponsiveness and an overrepresentation of these B cells in the blood. This phenotype persists at least during the early time window after removal of HCV from the host.     

Antioxidant response to drought in red and white clover

Antioxidant response to drought in red (Trifolium pratense L., cv. ??Start??) and white clover (Trifolium repens L, cv. ??Haifa?? and cv. ??Debut??) grown as soil cultures was evaluated in water-deprived and recovered plants. Drought provoked oxidative stress in leaves confirmed by the considerable changes in electrolyte leakage, malondialdehyde, hydrogen peroxides and proline contents. Immunoblot of ??-1-pyrroline-5-carboxylate synthetase (P5CS), which catalyzes the first two steps in proline biosynthesis, revealed strong induction of the enzyme in red clover plants submitted to drought. Water-deprived white clover plants exhibited distinct P5CS profiles. This was related to different drought tolerance of the studied T. repens cultivars. Isoenzyme analyses of superoxide dismutase (SOD), peroxidase (POX) and catalase (CAT) demonstrated certain differences in antioxidant defence among the tested varieties. It was confirmed that MnSOD (in both T. repens and T pratense) and FeSOD (in T. repens) isoforms were the most affected by drought. The red clover cultivar ??Start?? exhibited the lowest FeSOD and POX activities which could contribute to its poor performance under water deprivation.     

Ex vivo culture of intestinal crypt organoids as a model system for assessing cell death induction in intestinal epithelial cells and enteropathy

Intestinal epithelial cells (IECs) not only have a critical function in the absorption of nutrients, but also act as a physical barrier between our body and the outside world. Damage and death of the epithelial cells lead to the breakdown of this barrier function and inflammation due to access of the immune system to compounds of the intestinal flora. Intestinal epithelial damage is frequently associated with various inflammatory disorders, chemo- and radiotherapy as well as drug-mediated toxicity. Until recently, intestinal epithelial-damaging activities of drugs and treatments could be tested only in vivo in animal models because of the poor survival rate of primary IECs ex vivo. The three-dimensional culture and outgrowth of intestinal crypt stem cells into organoids have offered new possibilities to culture and study IECs ex vivo. Here we demonstrate that intestinal organoids are a useful and physiologically relevant model system to study cell death and survival in IECs. We further describe a number of microscopy-based as well as colorimetric methods to monitor and score survival and death of intestinal organoids. Finally, the comparison of organoids isolated from gene-deficient mice and wild-type mice allows investigating the role of specific genes in the regulation of IEC death. Owing to their comparable structure and behavior, intestinal organoids may serve as an interesting and physiologically relevant surrogate system for large- and mid-scale in vitro testing of intestinal epithelium-damaging drugs and toxins, and for the investigation of cell death pathways.     

Carney complex and lentiginosis

Initially described as the ‘complex of myxomas, spotty skin pigmentation and endocrine overactivity,’ Carney complex (CNC) is known as an autosomal dominant multiple neoplasia syndrome involving skin and cardiac myxomas, pigmented skin lesions and endocrine tumors. Pigmented cutaneous manifestations in CNC are important diagnostically because they can be used for the early detection of the disease and, thus, the prevention of life‐threatening complications of CNC related to heart myxomas and endocrine abnormalities. Specific for the disease skin lesions are present in more than half of the CNC patients. A major challenge is to distinguish pigmented skin lesions associated with CNC from other skin pathology, and thus accurately estimate the risk of cancer in affected patients; curiously, patients with CNC do not appear to have predisposition to skin cancers whereas this is not the case with other genetic syndromes associated with melanotic and other cutaneous lesions. In this paper, we review the current knowledge on cutaneous pathology associated with CNC and the most recent data on the molecular basis of the disease.