47 research outputs found
Pathological and histopatnotogical studies of the swimbladder of eels Anguilla anguitla infected by Angutlticpta crassus (Nemafoda: Dracuncuioidea)
The swimbladder lesions produced by Anguillicola crassus (Nematoda) infection, causing mass mortality among eels in Lake Balaton (Hungary) were studied by histological methods. In the initial phase of infection, no severe changes developed in the swimbladder wall despite the presence and intensive blood-sucking activity of worms that filled the lumen of the swimbladder. After disruption of the worms and primarily because of repeated reinfection by larvae, however, the wall of the swimblaader markedly thickened and showed degenerative, inflammatory and proliferative changes. Acute processes were characterized by epithelial hyperplasia and hyperaemia of the swimbladder wall. In cases of chronic swimbladder inflammation, oedema and hyperplasia of tissues of the tunica propria, submucosa and serosa could be observed, as well as granulomatoid infiltration by mononuclear cells and fibrinoid degeneration around the larvae
Full genome sequence of a novel circo-like virus detected in an adult European eel Anguilla anguilla showing signs of cauliflower disease.
An adult European eel Anguilla anguilla, showing typical signs of the so-called cauliflower disease, was subjected to pathological and molecular virological examinations. Samples taken from internal organs and the polypoid proliferative tissue from the mouth were examined by PCR for the detection of several viruses. Positive results were obtained with a nested PCR targeting the rep gene of circoviruses. Analysis of the partial rep sequence indicated the presence of a putative novel circovirus, but attempts to isolate it remained unsuccessful. The missing part of the genome was acquired by an inverse nested PCR with 2 specific primer pairs, designed from the newly determined rep sequence, followed by genome walking. The circular full genome was found to consist of 1378 nt (GenBank accession no. KC469701). Two oppositely oriented open reading frames (ORFs) were present, of which one was unambiguously identified as a circoviral rep gene. However, the predicted product of the other ORF, though it is a clear positional counterpart of the cap genes, showed no obvious homology to any known circoviral capsid proteins. A stem-loop-like element in the intergenic region between the 5' ends of the ORFs was also found. Phylogenetic calculations indicated that the novel virus belongs to the genus Circovirus in the family Circoviridae. The relative amount of the viral DNA in the organ samples was estimated by quantitative real-time PCR. The results suggested that the examined fish was caught in an active viremic state, although the role of this circovirus in the etiology of the cauliflower diseases could not be ascertained
A 90-Day Oral Toxicological Evaluation of the Methylurate Purine Alkaloid Theacrine
A 90-day repeated-dose oral toxicological evaluation was conducted according to GLP and OECD guidelines on the methylurate purine alkaloid theacrine, which is found naturally in certain plants. Four groups of Hsd.Brl.Han Wistar rats (ten/sex/group) were administered theacrine by gavage doses of 0 (vehicle only), 180, 300, and 375 mg/kg bw/day. Two females and one male in the 300 and 375 mg/kg bw/day groups, respectively, died during the study. Histological examination revealed centrilobular hepatocellular necrosis as the probable cause of death. In 375 mg/kg bw/day males, slight reductions in body weight development, food consumption, and feed efficiency, decreased weight of the testes and epididymides and decreased intensity of spermatogenesis in the testes, lack or decreased amount of mature spermatozoa in the epididymides, and decreased amount of prostatic secretions were detected at the end of the three months. At 300 mg/kg bw/day, slight decreases in the weights of the testes and epididymides, along with decreased intensity of spermatogenesis in the testes, and lack or decreased amount of mature spermatozoa in the epididymides were detected in male animals. The NOAEL was considered to be 180 mg/kg bw/day, as at this dose there were no toxicologically relevant treatment-related findings in male or female animals
Molecular detection of a putatively novel cyprinid herpesvirus in sichel (Pelecus cultratus) during a mass mortality event in Hungary
In the early summer of 2014, mass mortality of Sichel (Pelecus cultratus) was observed in Lake Balaton, Hungary. Histological examination revealed degenerative changes within the tubular epithelium, mainly in the distal tubules and collecting ducts in the kidneys and multifocal vacuolisation in the brain stem and cerebellum. The routine molecular investigations showed the presence of the DNA of an unknown alloherpesvirus in some specimens. Subsequently, three genes were amplified and sequenced partially from the putative herpesviral genome (DNA polymerase, terminase, and helicase). Phylogenetic tree reconstruction, based on the concatenated sequence of these three conserved genes, implied that the virus undoubtedly belongs to the genus Cyprinivirus within the family Alloherpesviridae. The sequences of the Sichel herpesvirus differ markedly from those of the three known cypriniviruses (CyHV-1, CyHV-2 and CyHV-3); putatively representing the fourth virus species in the genus
Subchronic exposure to deoxynivalenol exerts slight effect on the immune system and liver morphology of growing rabbits
As the most common grain contaminant worldwide, deoxynivalenol is of high importance despite its low toxicity compared to other trichothecene mycotoxins. Data on the effects of deoxynivalenol in rabbits are scarce. Thus, the aim of this study was to investigate the effects of dietary deoxynivalenol fed at a high level (10 mg/kg of feed) on the productive performance, blood indices, immunological variables, histopathological changes, and genotoxicity in rabbits. Forty-eight Pannon White rabbits were exposed to contaminated diets for three weeks. Despite its high concentration, deoxynivalenol did not affect the feed intake, body weight, and body weight gain. Liver and kidney function was not affected, as shown by the clinical chemistry indices. Conversely, in two rabbits the toxin caused mild fibrosis of the liver, without degenerative changes of the hepatocytes. No genotoxicity could be observed either. Gut cytokines and the phagocytic activity of the macrophages did not differ significantly. The percentage of neutrophils was significantly lower, whereas that of eosinophils was significantly higher in the toxin-fed group. Deoxynivalenol did not cause significant changes in gut and villus morphology. In 4 out of the 6 deoxynivalenol-treated animals, the ratio of lymphoblast proliferation and simultaneous apoptosis shifted towards apoptosis in the gut-associated lymphoid tissue. In the central part of the lymphoid follicles of the spleen, lymphocyte depletion and follicular atrophy could be detected. It can be concluded that rabbits are less sensitive to deoxynivalenol, but the findings confirm that this Fusarium toxin is capable of modulating the immune response