12 research outputs found

    Recovery ability of common carp (Cyprinus carpio) after a short-term exposure to terbuthylazine

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    Effects of a high terbuthylazine concentration (3.3 mg/l) on Cyprinus carpio were studied using a commercial herbicide formulation Click 500 SC (terbuthylazine 500 g/l). The fish were exposed to the pesticide for 24 h and allowed to recover for 6 days. Biometric parameters, plasma biochemical parameters and biomarkers of oxidative stress as well as histopathological changes in selected tissues were assessed on day 1 and 7. After a 24-h exposure, there were significant alterations found in the activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) as well as in the plasma concentrations of glucose, natrium, chlorides, calcium and phosphorus. Hepatosomatic index, plasma albumin and lactate reflected the treatment with a delay. Ion levels and ALT were found to be restored after a 6-day recovery period, which was too short for AST activity and glucose to diminish to the control levels. The histopathological examination revealed disorders in the gills of the exposed fish, however, the changes were not detected after a 6-day recovery period. The study shows high regeneration potential of the fish

    Effects of subchronic exposure to atrazine on zebrafish (Danio rerio)

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    The aim of this study was to investigate the effects of subchronic exposure to atrazine on fish growth and the development of histopathological changes in selected organs (gill, kidney, liver) in Danio rerio. Juvenile growth tests were performed on D. rerio according to OECD method No. 215. For 28 days, fish at an initial age of 30 days were exposed to the environmental atrazine concentration commonly detected in Czech rivers (0.3 ÎŒg/L) and a range of sublethal concentrations of atrazine (3.0, 30.0 and 90.0 ÎŒg/L). The results showed decreasing growth rates and morphological changes in the liver (dystrophic lesions of hepatocytes) at 90.0 ÎŒg/L of atrazine. The environmental concentration of atrazine in Czech rivers did not have any effect on fish growth and development of histopathological changes in D. rerio. The value of NOEC was 30.0 ÎŒg/L and the value of LOEC was 90.0 ÎŒg/L

    Response of a Collagenase-Induced Tendon Injury to Treatment with a Polysulphated Glycosaminoglycan (Adequan)

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    This study explored the hypothesis that local administration of a polysulphated glycosaminoglycan (PSGAG) in the early phase of healing of a standard collagenase-induced tendon injury in the superficial digital flexor tendon of the rabbit would reduce the degenerative effects of inflammatory mediators and proteases and preserve normal tendon morphology, composition, and biomechanical properties. Histological and ultrastructural changes together with the mechanical properties, dry weight, collagen content, and amount of DNA in healing tissue at the site of the lesion were assessed in treated and untreated animals. In treated lesions 28 days after injury, the normal orientation of tenoblasts and collagen fibrils was well preserved compared with the disorganized scar formation seen in untreated animals. The degree of cellularity was significantly higher in the untreated lesions. At the ultrastructural level the collagen in the healing tissue of the treated animals consisted of a mixture of small diameter, new regenerated fibrils intermingled with well-preserved large diameter, old fibrils, aligned to the long axis of the tendon; in untreated animals small, randomly arranged new fibrils predominated. The diameters of treated tendons had returned to normal, but in untreated animals the injured tendons remained significantly thicker than their controls. The percentage dry weight and collagen contents of treated injured tendons approximated those of control normal tendons, whereas those of untreated tendons were significantly less than those of the control values. The DNA content of injured treated tendons was not significantly different from that of normal contralateral controls, while in the untreated tendons it was significantly higher. There were no significant differences between the normal and the contralateral treated injured tendons in ultimate strength, fatigue strength, stiffness, and maximum absorbed energy. However in the untreated animals, although the tendon diameter was significantly greater, the ultimate strength, fatigue strength, stiffness, and maximum absorbed energy were significantly lower than the contralateral control. These data suggest that polysulphated glycosaminoglycans are effective in restoring the morphological, biochemical, and biomechanical properties of injured soft connective tissues and may be of clinical value in the treatment of acute tendon injury

    Effect of filler content on morphology and physical-chemical characteristics of poly(vinylidene fluoride)/NaY zeolite-filled membranes

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    Poly(vinylidene fluoride) electrospun membranes have been prepared with different NaY zeolite contents up to 32 wt%. Inclusion of zeolites induces an increase of average fiber size from ~200 nm in the pure polymer up to ~500 nm in the composite with 16 wt% zeolite content. For higher filler contents, a wider distribution of fibers occurs leading to a broader size distribution between the previous fiber size values. Hydrophobicity of the membranes increases from ~115Âș water contact angle to ~128Âș with the addition of the filler and is independent on filler content, indicating a wrapping of the zeolite by the polymer. The water contact angle further increases with fiber alignment up to ~137°. Electrospun membranes are formed with ~80 % of the polymer crystalline phase in the electroactive ÎČ phase, independently on the electrospinning processing conditions or filler content. Viability of MC3T3-E1 cells on the composite membranes after 72 h of cell culture indicates the suitability of the membranes for tissue engineering applications.This work was supported by FEDER through the COMPETE Program and by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Project PEST-C/FIS/UI607/2011 and the project Matepro-Optimizing Materials and Processes, "ref. NORTE-07-0124-FEDER-000037,'' co-funded by the "Programa Operacional Regional do Norte'' (ON.2-O Novo Norte), under the "Quadro de Referencia Estrategico Nacional'' (QREN), through the "Fundo Europeu de Desenvolvimento Regional'' (FEDER). A. C. L., C. R., and V. S. thank the support of the FCT (Grants SFRH/BD/62507/2009, SFRH/BPD/90870/2012 and SFRH/BPD/63148/2009 respectively). We also thank the support from the COST Action MP0902, Composites of Inorganic Nanotubes and Polymers, COINAPO
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