Myxobolus allami sp. n. is described from the intestinal wall of the silvery black porgy, Sparidentex hasta (Valenciennes), off Saudi Arabian coast of Arabian Gulf. Two of 20 examined fish were found to be infected with irregular-shaped plasmodia 3-8 mm long × 2-3 mm wide. Mature myxospores are subspherical to elliptical in the valvular view and oval in the sutural view, and are 11-13 (12) µm long, 7-8 (7.5) µm wide and 10-12 (10.8) µm thick. Spores have relatively thin valves and mostly (~ 72%) end with short caudal appendages of ~3 µm long. The spores also have two polar capsules, which are oval to elliptical and measure 5-7 (5.7) µm in length and 2-3 (2.7) µm in width. Polar filaments are coiled, with three turns. Transmission electron microscopy revealed that caudal appendages originated from the sutural edge at the posterior pole of the myxospore with density similar to that of its valves. The SSU rRNAgene sequence of the present species does not match any available sequences in GenBank. Phylogenetically, this species is sister to Myxobolus khaliji Zhang, Al-Qurausihy et Abdel-Baki, 2014 within a well-supported clade of Myxobolus-Henneguya with species infecting marine fishes. The combination of molecular data and morphological differences between this and other species of Myxobolus Bütschli, 1882 lead us to propose that the present form be established as a new species, M. allami. The present study also provides more evidence for the idea that caudal appendages cannot be reliably used to distinguish the species of the genera Myxobolus and Henneguya Thélohan, 1892.
Spermiogenesis in the amphilinidean cestode Amphilina foliacea (Rudolphi, 1819) was examined using transmission electron microscopy. The orthogonal development of the two flagella is followed by a flagellar rotation and their proximodistal fusion with the median cytoplasmic process. This process is accompanied by extension of both the mitochondrion and nucleus into the median cytoplasmic process. The two pairs of electron-dense attachment zones mark the lines where the proximodistal fusion of the median cytoplasmic process with the two flagella takes place. The intercentriolar body, previously undetermined in A. foliacea, is composed of three electron-dense and two electron-lucent plates. Also new for this species is the finding of electron-dense material in the apical region of the differentiation zone at the early stage of spermiogenesis, and the fact that two arching membranes appear at the base of the differentiation zone only when the two flagella rotate towards the median cytoplasmic process. The present data add more evidence for a close relationship between the Amphilinidea and the Eucestoda.
The effect of ultraviolet B radiation (UV-B) on cellular ultrastructure, chlorophyll (Chl), carotenoids, and total phenolics of Acrostichum danaeifolium gametophytes was analyzed. The control group of spores was germinated under standard conditions, while the test group of spores was germinated with additional UV-B for 30 min every day for 34 d. The cell characteristics were preserved in gametophytes irradiated with UV-B, but the number of starch grains increased in the chloroplasts and the more developed grana organization in contrast to the chloroplasts of the control group. Chl a content decreased, while Chl b content increased in the gametophytes cultivated with UV-B for 34 d. Contents of lutein and zeaxanthin decreased and trans-β-carotene concentration was enhanced in the gametophytes irradiated with UV-B. The content of total phenolic compounds increased in the gametophytes cultivated with UV-B. Therefore our data suggest that the gametophytes of A. danaeifolium, a fern endemic to the mangrove biome, were sensitive to enhancement of UV-B radiation at the beginning of their development and they exhibited alterations in their ultrastructure, pigment contents, and protective mechanisms of the photosynthetic apparatus, when exposed to this radiation., A. M. Randi, M. C. A. Freitas, A. C. Rodrigues, M. Maraschin, M. A. Torres., and Obsahuje bibliografii
Hypertension-induced myocardial metabolic, structural and electrophysiological remodeling deteriorates with aging and contributes to both heart failure and occurrence of malignant arrhythmias. It has been shown in clinical trials that n-3 polyunsaturated fatty acids (n-3 PUFA) reduce the incidence of cardiovascular diseases and sudden cardiac death. We investigated the cardioprotective effects of n-3 PUFA in aged spontaneously hypertensive rats (SHR) and possible cellular mechanisms involved. Male and female 14-month-old SHR were fed with n-3 PUFA (Vesteralens, Norway, 20 mg/day for two months) and compared with untreated SHR. Results showed that n-3 PUFA supplementation led to 1) significant decline of blood pressure; 2) suppression of inducible ventricular fibrillation (VF) by 57 % (male) and 67 % (female) , although the arrhythmogenic substrates, like fibrosis, hypertrophy and abnormal gap junctions distribution were not eliminated; 3) preservation of the cardiomyocytes and the inte grity of their junctions; 4) enhancement of energetic metabolism enzyme activity; 5) augmentation of capillary density associated with increased alkaline phosphatase and decreased dipeptidyl peptidase-4 (DPP4) activity and 6/ increase in gap junction channel connexin-43 expression. Thus, aged male as well as female SHR benefit from n-3 PUFA supplementation that results in decrease in VF susceptibility, partly due to an improvement of myocardial metabolic state, cardiomyocyte and cell-to-cell junctions integrity and Cx43 up-regulation., M. Mitašíková, S. Šmidová, A. Mascaliová, V. Knezl, K. Dlugošová, Ľ. Okruhlicová, P. Weismann, N. Tribulová., and Obsahuje bibliografii a bibliografické odkazy
In Capillaria pterophylli Heinze, 1933, two lateral bacillary bands extend along the whole body in female and male worms. A ventral bacillary band is present in females only. The bacillary bands consist of glandular and non-glandular cells, and in the region between the nerve ring and the end of the sticliosome, ciliated sense receptors in tight connection with gland cells are present.
Infection with the liver fluke Opisthorchis viverrini (Digenea) (Poirier, 1886) causes bile duct injury and periductal fibrosis by chronic overproduction of inflammatory-mediators and eventually results in cholangiocarcinoma development. While extensive research works have been done on O. viverrini infection-associated changes of bile ducts and periductal fibrosis, little attention was paid on morphological and biochemical changes of the bile canaliculi (BC), the origin of bile flow. We aimed to investigate the morphological and functional alterations of BC in the liver of hamsters infected with O. viverrini at one and three months post-infection. Ultrastructural changes of BC showed dilatation of BC and significant reduction of the density of microvilli as early as at one month post-infection. Immunohistochemistry revealed that CD10, a BC marker, expression was reduced early as one month post-infection. The mRNA expression of the genes encoding molecules related to bile secretion including bile acid uptake transporters (slc10a1 and slco1a1), bile acid dependent (abcb11) and independent (abcc2) bile flow and bile acid biosynthesis (cyp7a1 and cyp27a1) were significantly decreased at one month post-infection in association with the reduction of bile volume. In contrast, the expression of the mRNA of bile acid regulatory genes (fxr and shp-1) was significantly increased. These changes essentially persisted up to three months post-infection. In conclusion, O. viverrini infection induces morphological and functional changes of BC in association with the decrease of bile volume.
Calodium hepaticum (Bancroft, 1893) Moravec, 1982 (syn. Capillaria hepatica) is a cosmopolitan capillariid nematode, infecting mainly rodents and occasionally other mammals, including humans. Reports of C. hepaticum in canids are rare and the present one is, to the best of our knowledge, the first reported case in a red fox (Vulpes vulpes Linnaeus) in Italy. Scanning electron microscopy (SEM) examination of the eggs of C. hepaticum allowed a precise description of the egg morphology, which is one of the most relevant specific characteristics of capillariid nematodes. The egg shell showed a fibrous beam-like network which differs from that of the eggs of closely related trichinelloid species. This characteristic can be useful especially in case of spurious infection, when misdiagnosis among different trichinelloids species can occur.
The mechanisms and myocardial alterations associated with NO-deficient hypertension are still far from clear. The aim of the present study was to focus on the enzyme histochemical and subcellular changes in the heart of L-NAME treated rats, as well as to examine the influence of captopril treatment. Wistar rats were administered either L-NAME (40 mg/kg/day) alone or together with captopril (100 mg/kg/day) for a period of 4 weeks. A significant increase of blood pressure confirmed the reliability of the model. The results showed that long-lasting L-NAME administration was accompanied by a decrease of endothelial NO-synthase activity and by a significant local decrease of the following enzyme activities: capillary-related alkaline phosphatase, 5’-nucleotidase and ATPase (but not dipeptidyl peptidase IV) and cardiomyocyte-related glycogen phosphorylase, succinic dehydrogenase, ß-hydroxybutyrate dehydrogenase and ATPases. No activity of these enzymes was found in the scar, whereas a marked increase of alkaline phosphatase and dipeptidyl peptidase IV activities was found in the foci of fibrotization. Histochemical changes correlated with subcellular changes, which were characterized by 1) apparent fibroblast activation associated with interstitial/perivascular fibrosis, 2) heterogeneous population of the normal, hypertrophic and injured cardiomyocytes, 3) enhancement of the atrial granules and their translocation into the sarcolemma, and 4) impairment of capillaries as well as by induction of angiogenesis. Similar alterations were also found in the heart of captopril co-treated rats, despite of the significant suppression of blood pressure. The results indicate that NO-deficient hypertension is accompanied by metabolic disturbances and ultrastructural alterations of the heart and these changes are probably not induced by the renin-angiotensin system only., N. Tribulová, Ľ. Okruhlicová, I. Bernátová, O. Pecháňová., and Obsahuje bibliografii
The posterior attachment organ (sucker) of Temnocephala sp. is located ventrally attached to the posterior end of the body by a well defined stalk; those of Udonella caligorum Johnston and Anoplodiscus cirrusspiralis Roubal, Armitage et Rohde are extensions of the posterior end facing posteriorly. In Philophthalmus, the sucker is ventrally embedded in the main body. The sucker of Temnocephala is lined by an epidermis, its ventral part separated from the adjacent epidermis by a septate junction. The epidermis resembles that of the body proper, containing nuclei and numerous dense bodies, its surface enlarged by short microvilli, traversed by glandular ducts of two types and by sensory receptors, and based on a basal lamina with a thick underlying fibrous matrix. The stalk of the sucker contains many muscle fibres extending from the main body into the sucker. The posterior surface of the sucker of Udonella is separated from the adjacent tegument by a septate junction; it consists of numerous microvilli arising from the basal lamina and does not represent a tegument; glandular ducts of two types open through it, and muscle fibres extend from the body proper into the sucker. The posterior surface of the sucker of Anoplodiscus consists of a thin tegument not separated from the adjacent tegument by a septate junction, drawn out into a very large number of densely packed, long microvilli, some branching from a thick cross-striated base; large glandular ducts open postero-laterally. The ventral sucker of Philophthalmus is embedded in the body proper but clearly bounded by a “capsule” of basal lamina; it is lined by a tegument continuous with that of the main body and lacking microvilli except in a small band around the ventral sucker opening. There is no evidence from ultrastructure that the stickers of the four taxa are homologous. Since there is no convincing other evidence for the homology of the posterior attachment organs of the major groups of parasitic Platyhelminthes (Neodermata) and the Temnocephalida, a “cercomer theory” assuming such homology cannot be accepted as proven.
The pericarp of cereal crops is considered a photosynthetically active tissue. Although extensive studies have been performed on green leaves, the photosynthetic role of the pericarp in cereal caryopsis development has not been well investigated. In the present study, we investigated the anatomy, ultrastructure, chlorophyll (Chl) fluorescence, and oxygen evolution of the pericarp during caryopsis ontogenesis in field wheat (Triticum aestivum L.). The results showed that wheat pericarp cross-cells contained Chl; the grana stacks and thylakoid membranes in the cross-cells were more distinct in the pericarp than those in the flag leaves as shown by transmission electron microscopy. Chl fluorescence revealed that the photosynthetic efficiency, which was indicated by values of maximum efficiency of PSII photochemistry and effective PSII quantum yield, was lower in the pericarp compared to that of the flag leaf eight days after anthesis (DAA), whereas similar values were subsequently observed. The nonphotochemical quenching values were lower from 8-16 DAA but significantly increased in the pericarp from 24-32 DAA compared to the flag leaf. The oxygen evolution rate of the flag leaves was consistently higher than that of pericarp; notably, isolated pericarps released more oxygen than intact pericarps during caryopsis development. These results suggest that the pericarp plays a key role in caryopsis development by performing photosynthesis as well as by supplying oxygen to the endosperm and dissipating excessive energy during the
grain-filling stages., L. A. Kong , Y. Xie, M. Z. Sun, J. S. Si, L. Hu., and Obsahuje seznam literatury