Ischemic stroke causes brain damage and neuronal cell death by depriving oxygen and nutrients and releasing excessive levels of glutamate and intracellular calcium. Epigallocatechin gallate (EGCG) is a polyphenolic compound present in green tea. It has antioxidant, anti-inflammatory, and neuroprotective effects. Hippocalcin is a calcium binding protein that regulates calcium concentration, neuronal differentiation, neuronal excitability, and neuronal cell death. In this study, we investigated whether EGCG regulates the expression of hippocalcin in neurons and astrocytes after focal cerebral ischemia. Cerebral ischemia was induced by meddle cerebral artery occlusion (MCAO). EGCG (50 mg/kg) or PBS was injected into the abdominal cavity just before MCAO surgery. Neurobehavioral tests were performed to evaluate the effect of EGCG on neurological behavioral deficits 24 h after MCAO surgery. Immunofluorescence staining was performed to evaluate the positive response to hippocalcin in the cerebral cortex after MCAO surgery. We also detected the positive reactions of neuronal nuclear protein (NeuN) and glial fibrillary acidic protein (GFAP) as markers of neuron and astrocyte, respectively. MCAO caused severe neurological impairment and EGCG treatment attenuated these impairments. MCAO damage reduced the number of NeuN-positive cells and increased the number of GFAP-positive cells. This result indicates a decrease in neurons and an increase in astrocytes. However, EGCG alleviated these changes caused by MCAO damage. MCAO reduced the number of hippocalcin-positive cells in neurons and astrocytes, and EGCG treatment attenuated these reductions. Hippocalcin exerts neuroprotective effect through regulating intracellular calcium concentration. In conclusion, EGCG regulates the expression of hippocalcin in neurons and astrocytes and has neuroprotective effects in focal cerebral ischemia.
Hazard Analysis Critical Control Point (HACCP) is a scientific and systematic food hygiene management method that identifies and controls hazards to ensure food safety. South Korea has made the application of HACCP mandatory across all slaughterhouses to supply safe animal products and has further established and utilized a general HACCP model and standardized plan for mammal slaughterhouses. To investigate the current status of the preparation and application of HACCP plans in slaughterhouses in South Korea, surveys were conducted with HACCP teams at 30 slaughterhouses. The challenges faced were the preparation and application of HACCP plans, such as during preparation of justification documents for hazard analysis, re-evaluations, and changes in process or when adjusting and reinforcing corrective actions for repetitive deviations. Additional needs were found for the smooth application of HACCP, including the provision of standardized manuals for HACCP applications, an easily accessible platform for exchanging scientific information, provision of standardized templates, and unification of templates. Overall, challenges were particularly experienced during hazard analysis and verification processes in the preparation and application of HACCP plans. This study provides information on the current status of HACCP applications in domestic slaughterhouses and baseline data for effective HACCP application in slaughterhouses.
The Animal and Plant Quarantine Agency conducts a targeted sampling plan and analysis for veterinary drugs within the country every year. Target compounds included tetrachlorvinphos as an organophosphate, diminazene as an anti-infective medication, ketoprofen as a nonsteroidal anti-inflammatory drug, triclabendazole and clorsulon as flukicides in 2022. These compounds were not included in National Residues Program (NRP), despite their high sales ranking. A total of 94 bovine muscle samples and 20 equine muscle samples were collected from various locations across the country. The analysis of target compounds in muscle was performed using LC-MS/MS coupled with Food code 8.3.1 revised in 2022. A 2 g sample of muscle tissue was extracted using a water: acetonitrile (1:4, v/v) solution, then cleaned up with C18 and hexane saturated with acetonitrile. Compounds were separated with C18 column and mobile phases consisted of 0.1% formic acid in water (A) and 0.1% formic acid in acetonitrile (B). All analytes exhibited good linearity with correlation coefficients (R2) higher than 0.992. The limit of quantification (LOQ) of these compounds ranged from 0.21 to 2.79 μg/kg except for diminazene (3.85~6.86 μg/kg). The average recoveries of these analytes were 89.45~129.13% in muscle at spiked level of 10 or 20 μg/kg. Relative standard deviations (%) (intra-day and inter-day) were lower than 20% for all target compounds, except for diminazene and triclabendazole, whose intra-day RSD % was slightly higher than 20% in equine muscle. Testing confirmed that all 94 bovine and 20 equine muscle samples from 9 provinces were free from residues of veterinary drugs. Monitoring of compounds not included in the NRP should continue to ensure consumer health and food safety.
Crowded pet shops can become infected with various pathogens. Although dog carriers of Clostridioides difficile tend to be asymptomatic, the toxigenic strains sometimes cause gastrointestinal symptoms in humans. The present study was conducted to determine the infection rate of C. difficile in pet shops. The feces of 137 dogs younger than one year of age, collected from four pet shops, were assessed by culture and PCR. Carriage rates of C. difficile in dogs aged ≤90, 91-180, and ≥181 day-old were 12.2% (10/82, 95% confidence interval: 6.0-21.3%), 0.0% (0/42, 95% confidence interval: 0.0-8.4%), and 7.7% (1/13, 95% confidence interval: 0.2-36.0%), respectively. Five C. difficile isolates carried genes encoding toxins A and B, while the remaining isolates contained only toxin B. However, none of the C. difficile carriers had diarrhea. These results highlight the necessity of promoting adequate hygiene precautions in pet shops to prevent infection by C. difficile.
From 2020, Korean Animal and Plant Quarantine Agency has reset the withdrawal time (WT) for veterinary drugs typically used in livestock in preparation for the introduction of positive list system (PLS) program in 2024. This study was conducted to reset the MRL for amprolium (APL) in broiler chickens as a part of PLS program introduction. Forty-eight healthy Ross broiler chickens were orally administered with APL at the concentration of 60 mg/L (APL-1, n=24) for 14 days and 240 mg/L (APL-2, n=24) for 7 days through drinking water, respectively. After the drug treatment, tissue samples were collected from six broiler chickens at 0, 1, 3 and 5 days, respectively. Residual APL concentrations in poultry tissues were determined using LC-MS/MS. Correlation coefficient (0.99 >), the limits quantification (LOQ, 0.3~5.0 μg/kg), recoveries (81.5~112.4%), and coefficient of variations (<15.5%) were satisfied the validation criteria of Korean Ministry of Food and Drug Safety. In APL-1, APL in all tissues except for kidney was detected less than LOQ at 3 days after drug treatment. In APL-2, APL in liver and kidney was detected more than LOQ at 5 days after treatment. According to the European Medicines Agency’s guideline on determination of withdrawal periods, withdrawal periods of APL-1 and APL-2 in poultry tissues were established to 3 and 2 days, respectively. In conclusion, the developed analytical method is sensitive and reliable for detecting APL in poultry tissues. The estimated WT of APL in poultry tissues is longer than the current WT recommendation of 2 days for APL in broiler chickens.
Selenium (Se) is known as an antioxidant mineral and heme iron is a major source for iron intake which can promote carcinogenesis in the body. This study was to investigate the effect of Se on heme-aggravated colon carcinogenesis in mice. Three experimental groups included control [normal diet + AOM (10 mg/kg body weight in saline)/DSS (2% in the drinking water)], [AOM/DSS + hemin (534 mg/kg body weight in CMC)], and [AOM/DSS + hemin + Se (2.82 mg/kg diet in CMC)] groups. Colonic mucosa were stained with 0.3% methylene blue and the colonic polyps, aberrant crypt (AC) and aberrant crypt foci (ACF) were counted. Lipid peroxidation in liver was evaluated by the thiobarbituric acid-reactive substances (TBARS) assay. The number of polyps in the hemin + Se group was 31.6% lower than that in the control group, and 41.4% lower than that in the hemin group. The number of AC in the hemin + Se group was 42.8% lower than that in the control group, and 49.1% lower than that in the hemin group. The number of ACF in the hemin + Se group was 49.0% lower than that in the control group, 45.7% than that in the hemin group. Hepatic TBARS level in the hemin + Se group was significantly low compared with the control group or the hemin group (p<0.05). These findings suggest that Se treatment may be protective against colon carcinogenesis promoted by a high heme-containing diet.
The aim of this study was to determine the contamination of mycotoxins and the concentration of preservatives and antioxidants in commercial pet food. 106 pet foods were purchased from online in Korea. Mycotoxin analysis were performed using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) and preservatives and antioxidants were analyzed by high performance liquid chromatography (HPLC). The contamination of the mycotoxins in all samples was proved to comply with the Korea legislation with regards to animal feed, the analyses revealed presence of aflatoxins, ochratoxin A, zearalenone and fumonisins, with values below 1.6 ㎍/㎏, 12.1 ㎍/㎏, 478.5 ㎍/㎏ and 1873.5 ㎍/㎏, respectively. Furthermore, the simultaneous presences of different mycotoxins were observed in most of positive samples. The levels of dehydroacetic acid (DHA), sorbic acid (SA) and benzoic acid (BA) were, respectively, with values below 0.24 g/㎏, 4.82 g/㎏ and 6.35 g/㎏. The concentrations of butylated hydroxy anisole (BHA) and butylated hydroxy toluene (BHT) were demonstrated to be acceptable, with values below 0.04 g/㎏, and 0.02 g/㎏. This indicated the need for further investigation into the potential risk deriving from chronic exposure to low doses of mycotoxins. Additionally, a co-contamination of mycotoxins which interact in synergic manner are more concern. As DHA that not accepted was detected and very high levels of SA were identified in samples, an upper limit for preservatives in pet foods should be established in pet foods. BHA and BHT were detected within the recommended levels for antioxidant content, so these are considered as safe.
A 11-year-old sexually intact female dog was presented because of a misshapen left elbow with a large mass. The masses on the elbow were diagnosed as high-grade canine mast cell tumor (cMCT) based on the cytological examination using fine-needle aspiration. Cytologically, the mass revealed moderate numbers of eosinophils, anisocytosis, anisokaryosis, and aberrant mitotic figures. The degree of cytologic dysplasia is diagnosed as moderate to severe. The blood analysis revealed low hematocrit and electrolytes. After examining the metastasis and surgical scope with radiographs and ultrasound, surgery was performed to removal the mass. Histopathologically, the mass revealed partially cytoplasmic granules, anisokaryosis of the nucleus, and mitotic counts. Scattered inflammatory cells and necrotic tissues were observed in the tumor. In this study, we found high-grade cMCT and treated the patient through a surgical approach.
This case report describes the pathological features of pulmonary alveolar proteinosis(PAP) in mouse. Grossly, multiple irregular yellow-grey patches were observed on the lung surface of a C57BL/6 mouse. Histopathologically, the alveolar walls were thickened by type II cell hyperplasia and cellular infiltrates, and the bronchioles and alveolar lumens were filled with amorphous eosinophilic lipoproteinaceous material. This material was positive for Periodic acid-Schiff stain. Gomori methenamine silver staining was negative. Immunohistochemical staining showed that cells in the alveolar wall and lumen were positive for surfactant protein B, chitinase-like protein-3, and CD68. As a result, PAP was diagnosed. This is a rare case of spontaneous PAP in mice, and we report the histopathological characteristics along with the literature.