End Of Experimental Time Research Articles

Uptake of enrofloxacin from seawater to the macroalgae Ulva and its use in IMTA systems

Integrated multi-trophic aquaculture systems can minimize the environmental impacts of aquaculture, while delivering economical benefits. However, the use of extractive species such as seaweeds can accumulate pharmaceuticals commonly used in these systems. Therefore, this work evaluated the exposure of the seaweed Ulva to enrofloxacin (ENR), a vastly used antimicrobial in aquaculture, at two dosages (C1, 7.5 μg L−1 and C2, 15 μg L−1), and concentrations in water and in Ulva were measured through time. Traditional endpoints such as growth and mortality were assessed as ENR effects in the macroalgae. Enrofloxacin presented good stability in seawater, and degradation rates were influenced by the presence of seaweed at the lowest concentration tested. The seaweed was able to assimilate the antibiotic, reaching internal concentrations of 7.76 ± 1.11 ng g−1 WW after 30 min of exposure for C1, and 14.51 ± 1.22 ng g−1 WW, after 15 min for C2. Lowest concentrations detected at the end of experimental time were 4.08 ± 0.42 ng g−1 WW and 5.09 ± 1.57 ng g−1 WW for C1 and C2, respectively, which nonetheless, corresponds to ∼5% of the maximum residue limit established for fish for ENR by the European regulation. The presence of ENR stimulated Ulva growth, with differences observed 96 h after the beginning of the trial.

The Use of a Hypoallergenic Dermal Matrix for Wrapping in Peripheral Nerve Lesions Regeneration: Functional and Quantitative Morphological Analysis in an Experimental Animal Model.

Introduction The aim of this research was to test, in an animal model, the nerve regeneration technique with a hypoallergenic acellular dermal matrix used to wrap the microsurgical neural suture. Materials and Methods Two groups of rats received the cut of limb right median nerves. The regeneration technique considers for both groups an end-to-end nerve suture. In the experimental group (A) was used also a wrapping protocol by a conduit of collagen matrix currently used in oral surgery. The animals underwent functional grasping tests (at 1, 3, 5, and 7 months) and a histological and quantitative analysis of distal nerve was performed at the end of experimental time. Result After seven months, the grasping test reveals functional recovery in each tested animal; this improvement is more evident in Group A. The fibers appear well organized with restored myelin sheaths in both groups. Group A showed a great quantity of connective tissue surrounding the nerve. The quantitative morphology analysis in both groups shows a similar fibers density, fiber diameter, and myelin thickness. The differences between the groups in axon mean diameter are significant. In Group A M/d, D/d, and g-ratio is significantly higher compared to control group. Conclusions Histological and functional assessments show a functional recovery of the injured nerve in the test groups, stressed by the results of the grasping tests and the meaningful increasing in fiber diameter and higher g-ratio. Moreover, a connective tissue cuff distinguishes the distal portion of the injured nerve. Considering the easy availability and handling of the material used in this study we can conclude that this experimental technique can be considered as a valid alternative to protect nerves in nerve wrap surgery.

Potential Protective Effect of Pentoxifylline on Myocardial Injury Induced by Ischemia Reperfusion in Rat Model: A Histological and Immuno-Histochemical Study.

Background: Although, myocardial reperfusion is a pre-requisite to salvaging viable myocardium, the process of restoring coronary blood flow can paradoxically induce myocardial injury and cardiomyocyte death. A number of new therapeutic strategies are currently under investigation for preventing myocardial reperfusion injury and to improve clinical outcomes. Aim of the work: This study was performed to assess the potential benefit of pentoxifylline in the reduction of myocardial injury induced by ischemia/reperfusion . Material and Methods: In this study, 30 adult male albino rats were divided into 3 groups; control group, group II: subjected to ischemia (temporary occlusion of the left anterior descending coronary artery for 45 minutes) followed by reperfusion (for 120 minutes), and group III: single dose of pentoxifylline (40 mg/kg/bw) was injected intraperitoneal, 15 minutes before induction of ischemia/reperfusion. Samples from left ventricle from all animals were excised immediately, at the end of experimental time, and processed for examination by light and transmission electron microscopes. Also, immunohistochemical examination using caspase 3 and Anti TNF-α antibodies was performed. Results: Histological assessment revealed that the pretreatment with pentoxphilline protected the myocardium against ischemic/reperfusion induced injury; as demonstrated by improvement of histological structure of cardiac myocytes, minimal edema, hemorrage and fibrosis. No cellular inflammatory infiltration. Also, marked reduction of cardiomyocyte necrosis, indicating strong anti- apoptotic effect of pentoxphilline, and weak expression of TNF-α , indicating strong anti-inflammatory effect of pentoxphilline.

Performance, carcass parameters, meat quality and lipid profile from feedlot young bulls fed cottonseed

SUMMARY The objective of this study was to evaluate the performance, carcass, meat quality, fatty acid profile and liver alterations of cattle supplemented with cottonseed feedlot. It used 100 Nelore cattle, being divided into two groups of 50 animals, which received a cottonseed (CS) in grain form by the diet in the proportion of 15% and the other group was provided with control diet without CS in the feedlot for 88 days. The diets were isoprotein and isoenergetic and concentrate:roughage ratio of 60:40. The animals were slaughter in the end of experimental time and the collection of liver samples for histological analysis. After cooling 24 hours at ± 1°C were conducted evaluation of carcass and major cuts, final pH and collected muscle samples longissimus to carry out the physicochemical analyzes (Color, Cooking Loss, Pigments and Shear Force), chemical composition, fatty acid profile and oxidation. The inclusion of CS in the diet provided animals with higher slaughter weight, daily weight gain, Hindquarter, however, the animals showed reduced carcass yield, forequarter weight and Thin flank, without changing the parameters as rib-eye area and backfat thickness. There was an increase of the yellow values (b*) and moisture with the final pH reduction. There was no influence of the use of cottonseed in relation to histological parameters evaluated in the liver. The cottonseed in the feeding feedlot cattle promoted improvement in animal performance, despite the reduction of the forequarter weight, with appropriate aspects of meat quality, fatty acid profile and conservation.

Hepatoprotective Effects Exerted by Propolis against Doxorubicin-induced Rat Liver Toxicity: A Biochemical and Histopathological Study

Doxorubicin (DOX) is a currently used broad spectrum anticancer agent used to treat many cancer types. DOX belongs to anthracycline group of cytotoxic drugs. Unfortunately, DOX induces many side effects e.g. cardiotoxicity, hepatotoxicity and nephrotoxicity. In this experimental study, we assessed the protective potential of honey bee propolis against DOX-induced side effects. Thirty Sprague Dawley male rats (weighing about 200-220 g) were included in our study and divided into three equal experimental groups: group I (untreated control), group II (DOX-treated rats) that received 25 mg/kg DOX by intraperitoneal (i.p) injection for three consecutive days and group III where animals received both DOX and propolis oral propolis (250 mg/kg for 30 consecutive days). By the end of experimental time, all animals were sacrificed on the 30th day where blood samples and tissue sections were collected for detection of the biochemical and histopathological changes. Our data revealed that propolis evidently resulted in hepatoprotective effects against DOX-induced toxicity in rats liver. It can be concluded that propolis provides partial protection against DOX-induced hepatotoxicity.

Low stocking density negatively affects growth, metabolism and stress pathways in juvenile specimens of meagre (Argyrosomus regius, Asso 1801)

The influence of culture density on growth, stress system and metabolism has been assessed in A. regius juveniles submitted to different initial stocking densities (3, 7, 10 and 13gL−1) for 40days. On days 0, 12, 27 and 40 of the experiment, biometric parameters were measured. In addition, plasma, liver and muscle samples were taken for biochemical analysis at the end of experimental time. Our results showed better growth rates and feed utilization in those specimens held at high stocking densities when compared to those under low stocking densities. In addition, higher plasma cortisol, glucose and triglycerides levels found in the lowest stocking density tested suggest an activation of the stress system in fish held at this condition. Moreover, no changes in hepatic metabolites were observed, while values of muscle triglycerides, amino acids and lactate enhanced when stocking density increased. In conclusion, the culture of juvenile A. regius at higher initial densities (at least 13gL−1) ensures better growth and the optimization of the existing facilities, improving welfare of this species in aquaculture systems.

Rheological properties of dental resin cements during polymerization

Purpose: The purpose of this study was to observe the change of viscoelastic properties of dental resin cements during polymerization. Materials and methods: Six commercially available resin cement materials (Clearfil SA luting, Panavia F 2.0, Zirconite, Variolink N, RelyX Unicem clicker, RelyX U200) were investigated in this study. A dynamic oscillation-time sweep test was performed with AR1500 stress controlled rheometer at 32℃. The changes in shear storage modulus (G'), shear loss modulus (G''), loss tangent (tan δ ) and displacement were measured for twenty minutes and repeated three times for each material. The data were analyzed using one-way ANOVA and Tukey's post hoc test (α =0.05). Results: After mixing, all materials demonstrated an increase in G' with time, reaching the plateau in the end. RelyX U200 demonstrated the highest G' value, while RelyX Unicem (clicker type) and Variolink N demonstrated the lowest G' value at the end of experimental time. Tan δ was maintained at some level and reached the zero at the starting point where G' began to increase. The tan δ and displacement of the tested materials showed similar pattern in the graph within change of time. The displacement of all 6 materials approached to zero within 6 minutes. Conclusion: Compared to other resin cements used in this study, RelyX U200 maintained plastic property for a longer period of time. When it completed the curing process, RelyX U200 had the highest stiffness. It is convenient for clinicians to cement multiple units of dental prostheses simultaneously. (J Korean Acad Prosthodont 2014;52:82-9)

Adverse Effects of Resuscitation With Lactated Ringer Compared With Ringer Solution After Severe Hemorrhagic Shock in Rats

Lactated Ringer (LR) is a widely used resuscitation fluid that is known to mediate beneficial effects on acid-base balance when compared with normal saline. We here compared LR with the more physiological Ringer solution (RS) regarding acid-base status, hemodynamics, survival, and organ injury following fluid resuscitation subsequent to severe hemorrhagic shock. Anesthetized rats were hemorrhaged to a mean arterial blood pressure of 25 to 30 mmHg within 30 min. After 60 min, they were resuscitated with either RS or LR (three times the shed blood volume) or with RS or LR plus blood (shed blood plus twice its volume) within 30 min. Subsequently, the animals were observed for further 150 min. When the rats were resuscitated with pure LR or RS, all animals of the shock/LR group, but only three of eight shock/RS group rats were dead 100 min later (median survival, 50 ± 13.1 vs. 120 ± 14.1 min; P < 0.05). Coadministration of the shed blood with RS or LR increased the survival rates to 100%. In these blood-resuscitated groups, organ injury, especially of the kidney, was diminished by the use of RS compared with LR. Time-matched acid-base parameters were not different in all shock groups until death of the animals or euthanasia at the end of experimental time. We conclude that, in severe hemorrhagic shock, resuscitation with RS leads to an improved outcome compared with resuscitation with LR, regardless whether blood is coadministered or not.