212 research outputs found

    Morphometric study on tadpoles of Bombina variegata (Linnaeus, 1758) (Anura; Bombinatoridae)

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    The tadpoles of Yellow-bellied toad (Bombina variegata) can be easily recognized from other Italian anuran species, except those of B. pachypus (though the two congeneric species are allopatric). In this paper we report morphometric data on B. variegata tadpoles from a Lombard population living near a torrent at 450 m a.s.l. On a sample of 264 tadpoles (stages 19-44, according to Gosner, 1960) we measured the following five variables: snout-vent length, tail length, maximum tail height, total length and weight. We found a slight allometric relationship between snout-vent length and tail length, while, as expectes,.the weight is nearly proportional to the cube of linear measures. According to literature data, our results point to highly constant proportions during the development phases up to prometamorphic stages. The ratio between snout-vent length and tail length was about 0.75 during the whole growing phase, while from stage 42 the proportion increases as the resorption of the tail starts

    Understanding the Pathogenesis of Red Mark Syndrome in Rainbow Trout (Oncorhynchus mykiss) through an Integrated Morphological and Molecular Approach

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    Red mark syndrome (RMS) is a widespread skin disorder of rainbow trout in freshwater aquaculture, believed to be caused by a Midichloria-like organism (MLO). Here, we aimed to study the pathologic mechanisms at the origin of RMS by analyzing field samples from a recent outbreak through gene expression, MLO PCR, quantitative PCR, and a histopathological scoring system proposed for RMS lesions. Statistical analyses included a One-Way Analysis of Variance (ANOVA) with a Dunnett’s multiple comparisons test to assess differences among gene expression groups and a nonparametric Spearman correlation between various categories of skin lesions and PCR results. In short, the results confirmed the presence of a high quantity of 16S gene copy numbers of Midichloria-like organisms in diseased skin tissues. However, the number of Midichloria-like organisms detected was not correlated to the degree of severity of skin disease. Midichloria-like organism DNA was found in the spleen and head kidney. The spleen showed pathologic changes mainly of hyperplastic type, reflecting its direct involvement during infection. The most severe skin lesions were characterized by a high level of inflammatory cytokines sustaining and modulating the severe inflammatory process. IL-1 β, IL-6, IL-10, MHC-II, and TCR were upregulated in severe skin lesions, while IL-10 was highly expressed in moderate to severe ones. In the moderate form, the response was driven to produce immunoglobulins, which appeared crucial in controlling the skin disease’s severity. Altogether our results illustrated a complex immune interaction between the host and Midichloria-like organism

    Gastrointestinal nematodes of dairy goats, anthelmintic resistance and practices of parasite control in Northern Italy

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    Background: Gastrointestinal nematodes (GINs) is one of the main constraints to ruminant production worldwide. Anthelmintic resistance (AR) has been reported in goats throughout Europe, yet little is known about the AR status in Italy. The aims of the study were: i) determine the frequency of AR in GINs in goat flocks in Northern Italy, Italy, ii) survey goat farmers on the current practices of parasite control, iii) update the species composition of the gastrointestinal helminthofauna. Thirty three flocks were enrolled and 1288 individual fecal samples were collected. Based on the egg per gram (EPG), 15 flocks were selected to evaluate the presence of AR in GINs with the Fecal Egg Count Reduction Test (FECRT). A questionnaire surveyed 110 dairy goat farmers to acquire information about farm management and drenching practices against GINs. Further, the gastrointestinal tracts of 42 goats were analyzed. Results: The FECRs indicated that five of the 15 flocks had problems of AR, which was identified in all two of the anthelmintic classes tested. Resistance and suspected resistance was found in 40% of the flocks selected for AR testing that were treated with benzimidazoles while 20% of the flocks treated with eprinomectin had resistant GINs. Teladorsagia/Trichostrongylus L3 were isolated from the post-treatment coprocultures of all flocks with resistance but not from the flock with suspected oxfendazole resistance. Treatments against helminths were performed once annually in 73.63% of the flocks, but 20.00% of farmers declared not regularly treating their goats every year. Annual treatments usually occurred in autumn or winter at dose rate for sheep. Te. circumcincta, H. contortus, Tr. colubriformis, Skrjabinema caprae and Oesophagostomum venulosum were the most abundant and prevalent species of the gastrointestinal tract. Conclusions: Strategies to prevent the development of AR should be widely adopted in Northern Italy. Further, farmers and practitioners should be educated about the importance of using the correct dose rates in goats. In addition, the presence of highly pathogenic GINs coupled with high worm burden in all sector of gastrointestinal tract and the prevalence values further suggest that improved diagnosis and active surveillance of GIN infection is needed

    Dietary Supplementation of Nile Tilapia (Oreochromis niloticus) With Panax ginseng Essential Oil: Positive Impact on Animal Health and Productive Performance, and Mitigating Effects on Atrazine-Induced Toxicity

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    The present study assessed the impact of Panax ginseng essential oil (GEO) supplementation on physiological parameters related to productive performance and health status in Nile tilapia reared under standard conditions and exposed to a sub-lethal atrazine (ATZ) concentration. Fish were allocated into 6 groups: the control group was reared in clean water and fed with a commercial basal diet (CNT), two groups were fed with the basal diet supplemented with two different levels of GEO (GEO1 and GEO2, respectively), one group was intoxicated with 1/5 of ATZ 96-h lethal concentration 50 (1.39 mg/L) (ATZ group), and the remaining two groups were fed with the GEO-supplemented diets and concurrently exposed to 1.39 mg ATZ/L (GEO1+ATZ and GEO2+ATZ, respectively). The experiment lasted for 60 days. GEO supplementation exerted a significantly positive influence on fish growth, feed utilization, and hepatic antioxidant defense systems at both levels of supplementation. ATZ exposure significantly reduced fish survival rates and impaired fish growth and feed utilization, with the lowest final weights, weight gain, total feed intake, and the highest feed conversion ratio being recorded in the ATZ-intoxicated group. ATZ exposure caused significant changes in intestinal digestive enzyme activity (decreased lipase activity), hematological indices (decreased hemoglobin, packed cell volume, erythrocytes, and leukocytes), blood biochemical variables (decreased total proteins, albumin, globulins, and immunoglobulin M; increased total cholesterol, triglycerides, and cortisol), and hepatic oxidative/antioxidant indices (decreased glutathione level, superoxide dismutase and catalase enzyme activity and mRNA expression levels, and increased malondialdehyde content). Moreover, in the hepatic tissue of ATZ-intoxicated Nile tilapia, histopathological alterations and upregulated mRNA expression levels of stress- and apoptosis-related genes (Hsp70, caspase 3, and p53) were observed. GEO supplementation in ATZ-treated groups significantly attenuated the aforementioned negative effects, though some parameters did not reach the CNT values. These findings provide further and partly new evidence that sub-lethal ATZ toxicity induces reduced survivability, growth retardation, impaired digestive function, anemia, immunosuppression, hepatic oxidative stress damage, and overall increased stress level in Nile tilapia, and suggest that GEO supplementation may be useful for mitigating this toxicity and provide more general support to the productive performance and health status of this fish species

    Immunosuppressive Effects of Thallium Toxicity in Nile Tilapia Fingerlings: Elucidating the Rescue Role of Astragalus membranaceus Polysaccharides

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    This study evaluated the immunotoxic effects of thallium (Tl) in Nile tilapia fingerlings and the recovery role of dietary Astragalus membranaceus polysaccharides (ASs). An 8-week experiment was designed where 180 fishes were randomly and equally assigned in triplicates into the six groups: the control group (CNT) was reared in unpolluted water and fed a commercial diet, two groups were fed a well-balanced commercial diet plus 1.5 and 3.0 g AS/kg diet (AS0.15 and AS0.30), respectively, the fourth group was exposed to a sublethal dose of Tl (41.9 μg l−1) [equal to 1/10 of 96-h lethal concentration 50 (LC50)], and the last two groups were fed 0.15 and 0.3% AS, respectively, and concurrently exposed to Tl (41.9 μg l−1) (AS0.15+Tl and AS0.30+Tl). Fish hematobiochemical parameters, serum immunity [nitric oxide, total immunoglobulin M (IgM) levels, and lysozyme activity], transcription of hepatic interferon-g (IFN-g), interleukin-1b (IL-1b), and tumor necrosis factor-a (TNF-a), and resistance to Aeromonas hydrophila (A. hydrophila) were assessed. Hematobiochemical parameters and serum immune indices were significantly decreased in the fish group exposed to sublethal Tl concentration compared to the CNT group. Furthermore, Tl exposure significantly induced overexpression of IL-1b, TNF-a, and IFN-g genes (4.22-, 5.45-, and 4.57-fold higher, respectively) compared to CNT values. Tl exposure also increased the cumulative mortality (%) in Nile tilapia challenged with A. hydrophila. Remarkably, the groups fed AS0.15+Tl and AS0.30+Tl significantly ameliorated all the aforementioned parameters, but did not reach CNT values. Our findings suggest the possible immunomodulating roles of dietary AS in recovering the immunotoxic effects of Tl in Nile tilapia. We can conclude that dietary AS would be useful for maintaining the immunity of Nile tilapia fingerlings

    Modulatory effect of thymol on the immune response and susceptibility to Aeromonas hydrophila infection in Nile tilapia fish exposed to zinc oxide nanoparticles

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    Zinc oxide nanoparticles (ZnO-NPs) have many exciting properties that make their use in a continuous increase in various biomedical, industrial, and agricultural applications. This is associated with accumulation in the aquatic ecosystems and fish exposure with consequent deleterious effects. To determine the potential of thymol to counteract the immunotoxic effects of ZnO-NPs, Oreochromis niloticus was exposed to ZnO-NPs (⅕ LC50 =1.14 mg/L, for 28 days) with or without feeding a thymol-incorporated diet (1 or 2 g/kg diet). Our data demonstrated a reduction of aquaria water quality, leukopenia, and lymphopenia with a decrease in serum total protein, albumin, and globulin levels in exposed fish. At the same time, the stress indices (cortisol and glucose) were elevated in response to ZnO-NPs exposure. The exposed fish also revealed a decline in serum immunoglobulins, nitric oxide, and the activities of lysozyme and myeloperoxidase, in addition to reduced resistance to the Aeromonas hydrophila challenge. The RT-PCR analysis showed downregulation of antioxidant (SOD) superoxide dismutase and (CAT) catalase gene expression in the liver tissue with overexpression of the immune-related genes (TNF-α and IL-1β). Importantly, we found that thymol markedly protected against ZnO-NPs-induced immunotoxicity in fish co-supplemented with thymol (1 or 2 g/kg diet) in a dose-dependent manner. Our data confirm the immunoprotective and antibacterial effects of thymol in ZnO-NPs exposed fish, supporting the potential utility of thymol as a possible immunostimulant agent

    Preparation and In-Vitro Evaluation of Controlled-Release Matrices of Losartan Potassium Using Ethocel Grade 10 and Carbopol 934P NF as Rate-Controlling Polymers

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    Controlled-release formulations are essential for those drugs that require fine tuning of their activity to increase the ratio between therapeutic vs. adverse effects. Losartan potassium is among those drugs whose adverse effects may somehow impair its purported benefits. Previous investigations have been carried out to ascertain the suitability of several polymers for being associated with losartan. This study is focused on the effects of Ethocel grade 10 and Carbopol 934P NF on losartan release. Flow and physical properties were assessed according to the protocols standardized by the pharmacopeia (USP-NF 29), and the drug release in phosphate buffer (pH = 6.8) was measured for 24 h. Data evidenced good to excellent flow and physical properties according to the drug/polymer ratio and the addition of co-excipients. The release rate in 24 h was found to be 63–69% to 79–82% without or with the addition of co-excipients, respectively, following zero-order kinetics. The results also suggest a significant difference with the release profile of a traditional release losartan formulation. The results suggest the suitability of Ethocel grade 10 and Carbopol 934P NF as components of a controlled-release losartan formulation

    Zinc Oxide Nanoparticles (ZnO-NPs) Suppress Fertility by Activating Autophagy, Apoptosis, and Oxidative Stress in the Developing Oocytes of Female Zebrafish

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    In vertebrates, the core mechanisms that control gametogenesis are largely multiple, complex, successive, and orchestrated by intrinsic and extrinsic factors. However, age, health status, and hormonal activity are important factors for good fertility; other intangible intracellular molecular mechanisms that manage oocyte development are still unclear. The present study was designed to elucidate the ultrastructure changes in the ovary in response to its exposure to zinc oxide nanoparticles (ZnO-NPs) and to explore the role of autophagy and apoptosis during egg maturation and ovulation on the fertility of female zebrafish. In our study, ZnO-NPs could induce cytotoxicity in the maturing oocyte by activating autophagy and apoptosis in a caspase-dependent manner and could induce oxidative stress by generating reactive oxygen species (ROS) that elevated the mutated ovarian tP53 protein. Simultaneously, necroptosis developed, mimicking the features of apoptosis and necrosis. Collectively, ZnO-NPs created a suitable necrotic environment that led to follicular developmental retardation that altered oocyte ovulation and reduced fecundity of female zebrafish
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