Use of computed tomography and magnetic resonance imaging to assess a case of spinal injury in a Showa koi Cyprinus carpio.

OBJECTIVE: A privately owned, 4-year-old female Showa koi (ornamental variant of Common Carp Cyprinus carpio) was presented for erratic swimming, air gasping, water spitting, and abnormal orientation in the water column. Initial physical examination revealed an obese patient with no external abnormalities except a small plaque localized to filaments on a right gill hemibranch. METHODS: The fish was anesthetized using AQUI-S 20E (10% eugenol solution) at 50 mg/L to facilitate diagnostic evaluation. Biopsy of the gill lesion yielded no significant findings. Whole-body computed tomography confirmed an excess of adipose tissue and mild scoliosis, with narrowing of the 10th-11th intervertebral space. A weight loss plan and need for repeat assessment were recommended. RESULT: The patient's original abnormal behaviors resolved over the following weeks, but it subsequently became hyporexic and depressed. Full-body magnetic resonance imaging (MRI) showed extensive alteration of vertebral centra, with multifocal compression of the spinal cord. Due to the patient's declining clinical condition and the grave prognosis based on MRI findings, the patient was humanely euthanized. CONCLUSION: Postmortem examination showed severe transmural myelomalacia associated with a vertebral subluxation. This case demonstrates the practical application of advanced cross-sectional imaging that has not been commonly afforded to fish or other lower vertebrates.

USE OF TOPICAL TREATMENTS AND EFFECTS OF WATER TEMPERATURE ON WOUND HEALING IN COMMON CARP (CYPRINUS CARPIO).

Skin lesions are frequently diagnosed in fish medicine. Although systemic fish treatments exist, little is known about the efficacy of topical drugs on fish skin lesions. This study aimed to investigate the efficacy of medical-grade honey and silver sulfadiazine on skin lesions using common carp (Cyprinus carpio) as a model. Additionally, the effect of temperature on the wound healing process was evaluated. Punch biopsies were generated on six fish per treatment group under anesthesia. Treatment groups received one of the following topical medications after wounding: Dr. Nordyke's Wound Honey, MicroLyte Ag Vet, or SilvaSorb Gel. Nontreated positive control groups were similarly wounded but did not receive topical treatment. Fish were housed at 10°C to 13°C or 18°C to 21°C for 29 days. Macroscopic evaluation and image collection of wounds were performed on days 0, 4, 8, 12, 21, and 29 after wounding to compare changes in wound areas and inflammation over time. On day 29, tissue samples were collected for histologic analysis. From day 12 after wounding onward, wounds in positive controls maintained at 18°C to 21°C were significantly smaller (days 12, 21, and 29: P < 0.0001) compared with positive controls kept at 10°C to 13°C. There was an overall improvement in macroscopic appearance in honey-treated groups compared with positive controls on day 12 after wounding at 18°C to 21°C (P = 0.001), whereas with the use of Microlyte and Silvasorb, wounds had increased inflammation grades (P < 0.0001 and P < 0.0001, respectively) with enlarged wound areas (P < 0.0001 and P < 0.001, respectively) in comparison with positive controls on day 12 after wounding at 18°C to 21°C. This study suggests that topical use of medical-grade honey produces positive effects on wound healing in the carp model and higher water temperatures enhance the effects, whereas the use of silver sulfadiazine and lower water temperatures delays or worsens the wound healing process.

Protective action of the phyllanthin against carbon tetrachloride-induced hepatocyte damage in Cyprinus carpio.

The present study was to investigate the protective effect and possible mechanism of phyllanthin against carbon tetrachloride (CCl4)-induced hepatocyte damage in carp. Phyllanthin (5, 10, and 15 µg/ml) was added to carp primary hepatocytes before (pre-treatment) and after (post-treatment) incubation of the hepatocytes in medium containing CCl4 at 8 mM; supernatant and cell were collected for the analyses of cell viability, biochemical parameters, and gene expression. The results showed that phyllanthin at the concentration of 15 µg/ml significantly suppressed the elevation of glutamate pyruvate transaminase (GPT), glutamate oxalate transaminase (GOT), lactate dehydrogenase (LDH), and malondialdehyde (MDA), and the reduction of cell viability, superoxide dismutase (SOD) activity, cytochrome P450 1a (CYP1A), and cytochrome P450 3a (CYP3A) messenger RNA (mRNA) levels expect LDH in the post-treatment. The levels of GPT, GOT, and CYP1A mRNA were also effectively restored in the pretreatment with phyllanthin (10 µg/ml). Overall, our results suggested that phyllanthin may be used as a hepatoprotective agent to prevent liver diseases in fish.

ß-glucan enriched bath directly stimulates the wound healing process in common carp (Cyprinus carpio L.).

Wound healing is a complex and well-organized process in which physiological factors and immune mechanisms are involved. A number of different immune modulators have been found to enhance the non-specific defence system in vertebrates, among which ß-glucans are the most powerful and extensively investigated. The aim of the present study was to investigate the biological impact of two different commercially available ß glucan containing products on the wound healing process in carp. Throughout a two week experiment fish were kept either untreated (control), or in water supplemented with the two different types of ß-glucans. The wound healing process was monitored using a multispectral visualisation system. The correlation between wound closure and immune response was investigated by measuring the gene expression patterns of IL-1ß, IL-6 family member M17, IL-8 and Muc5b, and measurement of production of radical oxygen species. PAMPs/DAMPs stimulation caused by the wounding and or ß-glucans resulted in an inflammatory response by activating IL-1ß, IL-6 family member M17 and IL-8 and differences in the expression pattern were seen depending on stimuli. IL-1ß, IL-6 family member M17 and IL-8 were activated in all wounds regardless of treatment. Expression of all three interleukins was highly up regulated in control wounded muscle already at day 1 post-wounding and decreased at subsequent time-points. The reverse was the case with control wounded skin, where expression increased from day 1 through day 14. The results for the ß-glucan treated wounds were more complex. The images showed significantly faster wound contraction in both treated groups compared to the control. The obtained results clearly demonstrated that a ß glucan enriched bath promotes the closure of wounds in common carp and induce a local change in cytokine expression.

The protective effect of silymarin on the carbon tetrachloride (CCl4)-induced liver injury in common carp (Cyprinus carpio).

Silymarin, a mixture of bioactive flavonolignans from the milk thistle (Silybum marianum), is traditionally used in herbal medicine to defend against various hepatotoxic agents. The aim of the present study was to evaluate the protective effect of silymarin against carbon tetrachloride (CCl4)-induced liver injury in fish. Common carp, with an average initial weight of 17.0 ± 1.1 g, were fed diet containing four doses of silymarin (0, 0.1, 0.5, and 1 g/kg diet) for 60 d. Fish were then given an intraperitoneal injection of CCl4 (30% in arachis oil) at a dose of 0.5 ml/kg body weight. At 72 h after CCl4 injection, blood and liver samples were collected for the analyses of serum biochemical parameters, liver index, peroxidation product, glutathione, and antioxidant enzyme activities. The results showed that administration of silymarin at 0.5 and 1 g/kg diet for 60 d prior to CCl4 intoxication significantly reduced the elevated activities of glutamate pyruvate transaminase, glutamate oxalate transaminase, lactate dehydrogenase (LDH), and increased the reduced levels of total protein and albumin in the serum. The reduced levels of liver index, superoxide dismutase, glutathione peroxidase, catalase, glutathione, and total antioxidant capacity were markedly increased, and malondialdehyde formation was significantly restrained in the liver. However, these parameters, except LDH, were not significantly changed in fish fed with silymarin at 0.1 g/kg diet. Based on the results, it can be concluded that silymarin has protective effect against CCl4-induced hepatotoxicity in fish. It is suggested that silymarin may be used as a hepatoprotective agent to prevent liver diseases in fish.

Response of the chromatophores in relation to the healing of skin wounds in an Indian Major Carp, Labeo rohita (Hamilton).

Chromatophores show significant changes during healing of skin wounds in Labeo rohita (Common Name--Rohu). Wound area can be divided into regions I, II and III. After infliction of wound, skin colour becomes significantly dark by 2h that is gradually restored by 2d. In regions II and III at 5 min, epidermal melanophores appear with beaded dendrites. In these regions at 2h and in region I at 6h, epidermal melanophores appear small, rounded or irregular shaped having dendritic processes with aggregated melanosomes. Subsequently, melanophores appear having elongated dendrites with dispersed or aggregated melanosomes. At 24h, clusters of pigmented bodies appear in regions I and II. These bodies increase up to 2d, and then diminish gradually and disappear by 8d. Changes in dermal melanophores in region II at 5 min indicate the onset of degeneration. Degenerating melanophores increase up to 12h, then gradually decline, and disappear by 4d. Simultaneously, stellate melanophore reappear, gradually increase and appear like control by 8d. Dermal melanophores in region III at different intervals appear stellate. In region I stellate dermal melanophores appear at 4d. Stellate melanophores in all regions show different distribution of dispersed or aggregated melanosomes. With the appearance of dermal melanophores, highly refractive, crystalline structures, possibly the refractive platelets of the iridophores, are visualized around them. At subsequent intervals, these are frequently observed. This study provides interesting insights in injury induced changes in chromatophores in fish. The findings could be considered useful in perception of intriguing features in the development of pigment research in future.

In vitro and in vivo hepatoprotective and antioxidant effects of Astragalus polysaccharides against carbon tetrachloride-induced hepatocyte damage in common carp (Cyprinus carpio).

The present study is aiming at evaluating the hepatoprotective and antioxidant effects of Astragalus polysaccharide (APS) on the carbon tetrachloride (CCl(4))-induced hepatocyte and liver injury in common carp in vitro and in vivo. In vitro, APS (200, 400 and 800 µg/ml) was added to the carp primary hepatocytes before (pre-treatment), after (post-treatment) and both before and after (pre- and post-treatment) the incubation of the hepatocytes with CCl(4) at 8 mM in the culture medium. APS at concentrations of 200, 400 and 800 µg/ml significantly improved cell viability and inhibited the elevation of glutamate pyruvate transaminase (GPT), glutamate oxalate transaminase (GOT), lactate dehydrogenase (LDH) and malondialdehyde (MDA) and significantly increased the reduced level of superoxide dismutase (SOD). In vivo administration of APS at the doses of 1.5 and 3 g/kg in the diet for 60 days prior to CCl(4) intoxication significantly reduced the elevated activities of GPT, GOT and LDH and increased the reduced levels of total protein and albumin in the serum; meanwhile, the reduced levels of SOD, glutathione and total antioxidant capacity (T-AOC) were markedly increased and the MDA formation was significantly inhibited in liver tissue. Overall results proved the hepatoprotective action of APS, which is likely related to its antioxidant activity. The results support the use of APS as a hepatoprotective and antioxidant agent in fish.