Metal-binding biomolecules in the liver of northern pike (Esox lucius Linnaeus, 1758): The first data for the family Esocidae.

Metal-handling strategies of various fish species are known to vary significantly in association with their intracellular metal behaviour. Thus, to better understand the possible consequences of increased metal exposure in fish it is important to perform comparative studies on metal-binding biomolecules in organs of different species. This study was the first of this kind on a liver of an esocid fish (northern pike, Esox lucius), and the gathered information were compared to fish belonging to three other families, Leuciscidae, Cyprinidae and Salmonidae. Distributions of ten elements among cytosolic biomolecules of different molecular masses were studied by size exclusion HPLC combined offline with high resolution ICP-MS. The results indicated predominant association of Co, Fe and Mo to high molecular mass biomolecules (>100 kDa), of Zn and Bi to both high and medium molecular mass biomolecules (>30 kDa), of Mn and Se to medium molecular mass biomolecules (30-100 kDa), and Ag, Cd and Cu to low molecular mass biomolecules (10-30 kDa), presumably metallothioneins. Evident binding to metallothioneins was also detected for Zn and Bi. For several metals, distinct differences were observed when cytosolic metal distributions of northern pike were compared to leuciscids, salmonids and cyprinids. More pronounced Zn binding to metallothioneins was recorded in leuciscids and cyprinids than both esocids and salmonids, whereas cytosolic Mn and Se distributions clearly differed between all studied fish families. Accordingly, in assessment of metal pollution it is vital to consider the exposed species, which requires prior comprehensive comparative research on numerous aquatic organisms.

Aspergillus Section Fumigati Pneumonia and Oxalate Nephrosis in a Foal.

Equine pulmonary aspergillosis is a rare deep mycosis often due to the hematogenous spread of hyphae after gastrointestinal tract disease. We describe herein the main clinic-pathological findings observed in a foal, which spontaneously died after showing diarrhea and respiratory distress. Necropsy and histopathological investigations allowed to diagnose pulmonary aspergillosis, which likely developed after necrotic typhlitis-colitis. Biomolecular studies identified Aspergillus section Fumigati strain as the causative agent. Notably, severe oxalate nephrosis was concurrently observed. Occasionally, oxalate nephropathy can be a sequela of pulmonary aspergillosis in humans. The present case report suggests that the renal precipitation of oxalates can occur also in horses affected by pulmonary aspergillosis and could likely contribute to the fatal outcome of the disease.

Effects of nitric oxide on blood-brain barrier permeability in common carp (Cyprinus carpio L.).

OBJECTIVE: To determine in vivo effects of nitric oxide (NO) on blood-brain barrier (BBB) permeability in common carp (Cyprinus carpio L.). ANIMALS: 148 carp. PROCEDURES Carp received glyceryl trinitrate (1 mg/kg) as an NO donor or received no treatment (control group). Nitrite and nitrate concentrations in carp sera were determined 0.25, 1, 3, 6, 8, 12, and 24 hours after treatment. In control and treatment groups, BBB permeability was analyzed by assessment of leakage of Evans blue dye into various brain areas at 6, 12, and 24 hours after glyceryl trinitrate treatment. Brain edema was determined by means of the wet-dry weight method and assessed with light microscopy on H&E-stained preparations of tissues obtained 6 and 24 hours after glyceryl trinitrate treatment. RESULTS: Treatment with glyceryl trinitrate induced endogenous synthesis of NO, which was upregulated 6 and 8 hours after treatment. Increased NO synthesis was associated with increased permeability of the BBB, which developed 6 hours after treatment with the NO donor. Although the BBB became impermeable again by 12 hours after glycerol trinitrate treatment, brain edema still persisted 24 hours after treatment. CONCLUSIONS AND CLINICAL RELEVANCE: In this study, treatment with an NO donor caused reversible opening of the BBB and brain edema in common carp. An intact BBB is important to prevent influx of potentially harmful substances into the brain. This investigation highlighted the possibility of BBB disarrangement caused by NO, a substance found in the CNS of all vertebrates evaluated.

Pomphorhynchus laevis (Acanthocephala) from the Sava River basin: New insights into strain formation, mtDNA-like sequences and dynamics of infection.

Here we report the genetic variability and presence of mtDNA-like sequences of Pomphorhynchus laevis from the chub, Squalius cephalus, caught at the sampling sites along the Sava River and its tributary the Sutla River in Croatia. Sequences of the cytochrome c oxidase subunit 1 (COI) gene of the recovered P. laevis specimens were used for haplotype network construction and phylogenetic analysis. These analyses showed that some specimens contained mitochondrial-like sequences, and they uncovered the existence of a Sava River basin strain different from known strains of P. laevis. This is the first time that P. laevis has been shown to contain mtDNA-like sequences, suggesting the need to exercise caution during COI analyses of P. laevis using universal primers. Highly conserved sequences of two nuclear markers, the ITS region and 18S rRNA, were not helpful for understanding genetic variability or differentiating strains. Furthermore, analysis of the dynamics of P. laevis infections in S. cephalus from the Sava and Sutla Rivers showed decreased prevalence and abundance at sites with inferior water quality, positive association of parasite abundance with fish size, and no clear association of parasite abundance with fish condition index or sex.

Structural changes in the rat placenta during the last third of gestation discovered by stereology.

Structural changes in the rat placenta during the last third of gestation were for the first time assessed by stereology. Fischer female rats were euthanized on the day 16 or day 19 of gestation, and 35 placentas were collected. Three randomly selected placentas from each group were stereologically analyzed for the absolute volume. The proportion of the glycogenic cells and the trophoblast giant cells (TGC) in the basal part of the placenta was calculated using volume density. The absolute volume of the rat placenta on the day 16 of gestation was determined as 0.0638 cm3. The labyrinth comprised 0.0274 cm3, the basal plate 0.0271 cm3 and the decidua 0.0093 cm3. On the day 19 of gestation, the absolute volume of the placenta was 0.1627 cm3, the labyrinth occupied 0.0922 cm3, the basal plate 0.0596 cm3 and the decidua 0.0109 cm3. The volume density of trophoblast giant cells was 0.174 cm0 on the day 16 and 0.107 cm0 on the day 19 of gestation. The glycogenic cells comprised 0.379 percentage of the basal plate on the day 16 and 0.236 on the day 19 of gestation. We conclude that the absolute volume of the whole placenta and the labyrinth has increased from day 16 to the day 19 of gestation. In contrast, the volume density of glycogenic cells and trophoblast giant cells was higher on the day 16 than on the day 19 of gestation, probably due to the intensive trophoblast invasion during that time.

Increased permeability of the blood-brain barrier following administration of glyceryl trinitrate in common carp (Cyprinus carpio L.).

Nitric oxide (NO) has been implicated in the pathogenesis of migraine and treatment with its exogenous donor glyceryl trinitrate (GTN) represents widely accepted experimental "migraine model". In this study, glyceryl trinitrate was administered intraperitoneally to carps, serum nitrite and nitrate levels were determined, permeability of blood-brain barrier was investigated, and histological changes of brain tissue were analyzed. Serum nitrite and nitrate levels displayed characteristic biphasic pattern with moderate initial increase and maximal terminal increase, suggesting the GTN-induced endogenous NO synthesis. Increased permeability of the blood-brain barrier in GTN-treated animals was determined based on Evans blue capillary leakage into the brain tissue. Histological analysis revealed changes consistent with vasodilatation and oedema. Our study strongly supports the importance of the NO role in the pathogenesis of migraine attacks and increase in blood-brain barrier permeability during the attack. The study has also provided evidence that this mechanism of action is conserved to the lower vertebrate.