While investigating the parasites of several marine fishes from the Western Atlantic, the Southern Gulf of Mexico and Central America (Panama), the following monogenoidean species from the gills of gerreid fishes (Gerreidae) were found: Diplectanum gatunense sp. n. (Diplectanidae) and Octouncuhaptor eugerrei gen. et sp. n. (Dactylogyridae) in Eugerres brasilianus (Cuvier) from Gatun Lake in the Panama Canal Watershed, and Diplectanum mexicanum sp. n. in Diapterus rhombeus (Cuvier) from the coast of Campeche State, Mexico. New diplectanid species are distinguished from other species of the genus by the general morphology of the copulatory complex and by the shape of the anchors and bars on the haptor. Octouncuhaptor gen. n. is proposed for its new species having slightly overlapping gonads (testis posterodorsal to the ovary), a dextrolateral vaginal aperture, a copulatory complex consisting of a coiled male copulatory organ with counterclockwise rings with the base articulated to the accessory piece, 8 pairs of hooks and the absence of anchors and bars on haptor. Our analysis of morphological features of Diplectanum species on gerreids evidences that these parasites more closely resemble each other than the known species from sciaenids suggesting that split between gerreids and sciaenids resulted in parasite speciation.
Specimens representing two new species of Guidus Ivanov, 2006 were collected from the Magellan skate (Bathyraja magellanica [Philippi]) in the Patagonian Continental Shelf of Argentina, Southwestern Atlantic Ocean. Guidus francoi sp. n. and Guidus magellanicus sp. n. differ from their congeners by a particular combination of features, including type of bothridia, worm length, number of testes, and distribution of vitelline follicles. Guidus francoi sp. n. is distinguished from G. magellanicus sp. n. by having fewer proglottids, fewer testes and a higher ratio between the cirrus sac length and the proglottid width. The microthrix pattern of species of Guidus from the Southwestern Atlantic is described, based on specimens of G. francoi sp. n., Guidus magellanicus sp. n., and newly collected specimens of Guidus argentinense Ivanov, 2006. These three species share the presence of wide aristate gladiate spinitriches on the proximal bothridial surface, narrow gladiate spinitriches on the bothridial rim, and filitriches on the distal bothridial surface. The diagnosis of Guidus is revised to include several features exhibited by the new species (i.e., presence of bothridial indentations and bothridial stalks, distribution of vitelline follicles, and eggs grouped in cocoons). The discovery of G. francoi sp. n. and G. magellanicus sp. n. from B. magellanica increases the number of species of Guidus collected from batoids in the Southwestern Atlantic from one to three. The specificity exhibited by the species herein described reinforces the tight association between rays in the genera Guidus and Bathyraja.
Despite the small sample size the diversity of Rhabdias Stiles et Hassall, 1905 from anurans in the Afrotropical region was found to be high. Four species were collected from four localities, one in South Africa, two on Cameroonese mountains and one in Madagascar: Rhabdias picardiae sp. n. from the bufonid Amietophrynus gutturalis (Power); Rhabdias ohlerae sp. n. and Rhabdias tanyai sp. n. from the arthroleptids Leptopelis brevirostris (Werner) and Astylosternus rheophilus Amiet, respectively; and Rhabdias vencesi sp. n. from the mantellid Boophis madagascariensis (Peters). Distinctive characters between these species are numerous and obvious, based on body size, shape and size of the buccal capsule, arrangement of head papillae, and shape and size of the oesophagus and intestinal apex. Molecular data based on 500 bp of 12S rDNA and 600 bp of coxI of three of the four species are presented. Rhabdias vencesi resembles Rhabdias madagascariensis Chabaud, Brygoo et Petter, 1961 from an African ptychadenid introduced on Madagascar, but differs in body size and head morphology. The remaining new species are clearly distinct from those previously known from Afrotropical anurans. Outside the Afrotropics, some Rhabdias species present characters similar to those observed in the new species, but they all differ in various other characters. No clear correlation was seen between Rhabdias species and families of anuran hosts in this region. However, the narrow buccal capsule seen in Rhabdias species from Afrotropical lissamphibians opposes them to the majority of Rhabdias parasitic in chamaeleonids. Furthermore, the infective larva of R. vencesi has a conical pointed tail, while those of Rhabdias from chameleons have a rounded tail tip ornated with a few buds.
We describe a new species of Scincella similar to Sphenomorphus tridigitus based on a single specimen from Lang Son Province, northeastern Vietnam. The new species differs from the latter by presence of lower eyelids with undivided opaque window, forelimbs with fi ve digits, and by absence of prefrontals. Scincella apraefrontalis sp. n. is distinguished from all other species of Scincella and all other Asian limbreduced lygosomines by a combination of the following characters: no supranasals; no prefrontals; nasal and fi rst supralabial fused; six supralabials; lower eyelid with undivided opaque disc; no external ear openings; 18 midbody scale rows; and pentadactyl limbs.
Three new myxosporean species are described from Tetraodon fluviatilis (Osteichthyes: Tetraodontidae) imported from Southeast Asia to the Czech Republic. Zschokkella tetrafluvi sp. n. lives in the gall bladder. Di- or monosporic plasmodia produce ellipsoidal spores averaging 11.3 x 7.2 pm. Zschokkella pleomorpha sp. n. infects renal tubules and renal corpuscles; mono- to polysporic plasmodia produce spores averaging 15.7 x 7.1 pm. In the process of maturation, immature subspherical spores assume elongated shape. In both species, extremely curved suture line does not bisect poles of the spore. Ortholinea tetrafluvi sp. n. occurs as a rule in mixed infections with Z. pleomorpha sp. n. in the renal tubules. Mono- to polysporic plasmodia produce spores with a wide anterior and a narrow posterior end, averaging 8.3 x 7.8 pm. Both Z. pleomorpha sp. n. and O. tetrafluvi sp. n. have also limited number of stages located within the renal tubule epithelium, where they can complete sporogony. In one of the fish specimens, a myxosporean tentatively identified with Sinuolinea tetraodoni El-Matbou)i et Hoffmann, 1994 was found. A new genus is proposed for Ortholinea alata Kent et Moser, 1990 - Kentmoseria gen. n., and its diagnosis is presented.
Our study concerned the findings that rat and rabbit heart transplants do not survive after six hours. They become dark, hard and fail to contract within 2 min after reperfusion and never regain their function. We tested the supplementation of solutions for heart transplant preservation with tetrahydrobiopterin (H4B) and L-arginine (L-ARG) to maintain the oxidative and reductive domains of the endocardial NO synthase. We decided to study the excised rabbit hearts preserved in Hank’s balanced salt solution (HBSS) at 0 °C supplemented with different concentrations of H4B (0, 1, 5, 10 or 100 /¿M). At desired time intervals, successive pieces stored in the above solutions were warmed to rabbit body temperature in 4 ml of HBSS and maximally agonized by direct application of 20 l of 200 M bradykinin (or other agonist) onto the exposed endocardium. Nitric oxide bursts were monitored with a porphyrinic NO sensor lying on the exposed endocardium. Our goal was to find the lowest H4B concentration which would maximally agonize NO * and prolong the time of heart preservation to more than 6 hours. Ten /iM are a minimum H4B concentration which achieves maximum prolongation of heart preservation time up to 90 hours. This effect was based upon maximal potentiation of NO* release and minimizing of superoxide production.
The new test approach for evaluation of thermo-visco-elastic parameters of elastomers is designed, realized and discussed herein. The main attention is devoted to a kinematically excited rubber beam specimen under transient resonant sweep excitation. Mechanical material characteristics, i.e. Young modulus and loss angle, are identified from analytical formulas of frequency function based on measured dynamic loading and response signals. Heat material constants were estimated indirectly by numerical thermo-mechanical FE model and matching numerical and experimental results. The 'sweep' regime tests serve for estimation of thermal and mechanical dependences. Long-term fatigue tests with cyclic resonant loading enable analysis of material degradation, such as hardening and permanent deformations. and Obsahuje seznam literatury
The cytotoxicity of 18 new 1,2,6-thiadiazin-3,5-dione 1,1-dioxides was evaluated. This group of products was previously assayed against epimastigotes of Trypanosoma cruzi and some of them showed a high antiprotozoal activity. Thereafter 13 compounds with a high anti-epimastigote activity and low cytotoxicity were selected to be assayed against amastigotes. Some of the products showed the same or even lower cytotoxicity than nifurtimox and benznidazole, but most of them were very toxic for macrophages at 100 µg/ml. Only one of the compounds had an anti-amastigote activity similar to that of reference drugs at 10 µg/ml, but unfortunately this disappeared at lower concentrations.