Establishment of withdrawal time and analysis of tiamulin residue in tissues of orally dosed broiler chickens

This study was conducted to investigate tiamulin (TML) residues in the edible tissues of orally dosed broiler chickens and to re-establish the withdrawal time (WT). Thirty-six healthy Ross broiler chickens were administered 0.5 (TML-1) and 2.5 kg (TML-2) per ton feed, respectively, of the drug containing TML 78 g/kg for 10 days. Twenty-four tissue samples were collected from 6 chickens in each of the TML-1 and TML-2 groups on 0, 1, 3, and 5 days after drug administration, respectively. The residual concentrations of TML were measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The correlation coefficient of the calibration curves was 0.9978 to 0.9998, and the limits of detection and the limits of quantification (LOQ) were in the range of 0.03 to 0.06, and 0.1 to 0.2 µg/kg, respectively. Recoveries ranged between 89.0% to 116.7%, and the coefficients of variation were less than 13.9%. After the drug administration, TML in the TML-1 and TML-2 groups was detected above the LOQ in 1 and 6 samples of liver, respectively, at day 0, and in 1 liver sample from both groups on day one. At 3 days after administration, TML was detected below the LOQ in all samples of TML-1 and TML-2. The calculated WT of TML in both TML-1 and TML-2 using the WT calculation program WT 1.4 was 0 days. In conclusion, the developed analytical method is suitable for detection, and the calculated WT of TML in poultry edible tissues is shorter than the current recommended WT of 7 days for TML in broiler chickens.

Establishment of withdrawal time and analysis of dexamethasone residue in milk of intramuscularly dosed cows

This study investigated dexamethasone (DXM) residues in the milk from intramuscularly dosed dairy cows and established the withdrawal time (WT) of DXM in milk. Eighteen healthy Holstein cows were injected with 20 (DXM-1) or 40 mL (DXM-2) of a drug containing 1 mg/mL of DXM. After administering DXM, milk samples were collected from all cows at 12-hour intervals for five days. The DXM residue concentrations in milk were determined by liquid chromatography-mass spectrometry/mass spectrometry. The correlation coefficient of the calibration curve was 0.9966, and the limits of detection and quantification (LOQ) were 0.03 and 0.1 μg/kg, respectively. The recoveries were 97.0% to 104.0%, and the coefficient of variations was less than 7.22%. After treatment, DXM in DXM-1 was detected above the LOQ in two milk samples at 36 hours and below the LOQ in all milk samples of DXM-2 at 48 hours. Using the WT calculation program WT 1.4, the withdrawal periods of DXM-1 and DXM-2 in milk were established to be two days. In conclusion, the developed analytical method is sensitive and reliable for detecting DXM in milk. The estimated WT of DXM in bovine milk is shorter than the current milk WT recommendation of three days for DXM in lactating dairy cows.

Anti-diabetic effects of aqueous extract of Dendropanax morbifera Lev. leaves in streptozotocin-induced diabetic Sprague-Dawley rats

This study examined the anti-diabetic effects of aqueous extracts of Dendropanax morbifera leaves (DMWEs) in streptozotocin-induced diabetic Sprague-Dawley (SD) rats. Thirty male SD rats (body weight [BW], 250.4 ± 19.7 g) were divided into the following six groups: normal control rats (NC), diabetic control rats (DC), diabetic rats treated with metformin HCl 100 mg/kg BW (DT), diabetic rats treated with DMWEs 50 mg/kg BW (DM-50), diabetic rats treated with DMWEs 100 mg/kg BW (DM-100), and diabetic rats treated with DMWEs 200 mg/kg BW (DM-200). From two weeks of administration of DMWEs, the BW of all groups treated with DMWEs increased significantly compared to DC (p < 0.05). At four weeks after treatment, the blood glucose levels in DT, DM-100, and DM-200 decreased below 200 mg/dL, while the glycated hemoglobin concentrations in all groups administered DMWEs were similar to those of NC and DT. Regarding the blood biochemical parameters, the levels of aspartate transaminase, alanine transaminase, blood urea nitrogen, and creatinine in DM-100 and DM-200 were similar to those in NC and DT. Overall, these results highlight the effectiveness of DM-100 in the treatment of diabetes.

Development of an analytical method for the determination of dl-methylephedrine hydrochloride in porcine muscle using liquid chromatography-tandem mass spectrometry

This study examined the residue of dl-methylephedrine hydrochloride (MEP) on the muscle of pigs administered orally with MEP 12 g/ton feed for seven consecutive days. Twenty healthy cross swine were administered MEP. Four treated animals were selected arbitrarily to be sacrificed at 1, 2, 3, 4, and 5 days after treatment. MEP residue concentrations in the muscle were determined by liquid chromatography coupled with tandem mass spectrometry. The drug was extracted from muscle samples using 10 mM ammonium formate in acetonitrile followed by clean-up with n-hexane. The analyte was separated on an XBridgeTM hydrophilic interaction liquid chromatography column using 10 mM ammonium formate in deionized distilled water and acetonitrile. The correlation coefficient (R2 ) of the calibration curve was 0.9974, and the limits of detection and quantification were 0.05 and 0.15 μg/ kg, respectively. The recoveries at three spiking levels were 94.5–101.2%, and the relative Standard Deviations was less than 4.06%.In the MEP-treated group, MEP residues on one day post-treatment were below the maximum residue limit in the muscle. The developed method is sensitive and reliable for the detection of MEP in porcine muscle tissues. Furthermore, it exhibits low quantification limits for animal-derived food products destined for human consumption.

Development of an analytical method for the determination of dl-methylephedrine hydrochloride in porcine muscle using liquid chromatography-tandem mass spectrometry

This study examined the residue of dl-methylephedrine hydrochloride (MEP) on the muscle of pigs administered orally with MEP 12 g/ton feed for seven consecutive days. Twenty healthy cross swine were administered MEP. Four treated animals were selected arbitrarily to be sacrificed at 1, 2, 3, 4, and 5 days after treatment. MEP residue concentrations in the muscle were determined by liquid chromatography coupled with tandem mass spectrometry. The drug was extracted from muscle samples using 10 mM ammonium formate in acetonitrile followed by clean-up with n-hexane. The analyte was separated on an XBridgeTM hydrophilic interaction liquid chromatography column using 10 mM ammonium formate in deionized distilled water and acetonitrile. The correlation coefficient (R2 ) of the calibration curve was 0.9974, and the limits of detection and quantification were 0.05 and 0.15 μg/ kg, respectively. The recoveries at three spiking levels were 94.5–101.2%, and the relative Standard Deviations was less than 4.06%.In the MEP-treated group, MEP residues on one day post-treatment were below the maximum residue limit in the muscle. The developed method is sensitive and reliable for the detection of MEP in porcine muscle tissues. Furthermore, it exhibits low quantification limits for animal-derived food products destined for human consumption.

Prevalence of allergic symptoms and occupational allergic diseases among veterinary clinic workers

Purpose@#Veterinary clinic workers are frequently exposed to various animal allergens, increasing the possibility of occupational allergy. However, allergic symptoms in this group have not been studied extensively. We aim to investigate the prevalence of allergic symptoms and especially occupational allergic diseases in veterinary clinic workers. @*Methods@#A questionnaire-based cross-sectional study was conducted. The questionnaire for allergic symptoms was sent to the veterinary clinic workers in the Gyeongsangnam-do region and was collected for statistical analysis. Occupational asthma, rhinitis, or dermatitis were defined as the new onset or worsening of each symptom at work and improvement in the condition while away from the work. @*Results@#Ninety-five veterinary clinic workers participated in this study; 33.7% were male and their mean age was 33.7 years. Fiftytwo subjects (54.7%) experienced conjunctivitis symptoms along with rhinitis symptoms. Fifty-seven subjects (60.0%) experienced rhinitis symptoms, but not cold or flu, and 40% of the subjects were suspected of having occupational rhinitis. Forty subjects reported that they had lower respiratory symptoms, while 11 (11.6%) and 4 subjects (4.2%) had asthma and occupational asthma, respectively. Twenty-two subjects with respiratory symptoms complained of symptom worsening upon contact with animals, especially cats. Of 95 subjects, 31 had skin itching, 11 reported skin rash, and 6 had occupational dermatitis. There was no significant difference in the type of work performed by the study participants. @*Conclusion@#This study is the first to analyze the prevalence of allergic symptoms in veterinary clinic workers in Korea. The data can be employed for the prevention of occupational allergic diseases in veterinary clinic workers and can provide a basis for further studies.

Conditions for the disinfectant efficacy test under subzero temperatures / 대한수의학회지

To establish appropriate conditions for a disinfectant efficacy test at subzero temperatures, this study examined mixtures of frozen foot-and-mouth disease virus or avian influenza virus solutions and disinfectant diluents at −5℃ and monitored temperature and freezing status of an anti-freezing diluent (AFD, 15% ethanol + 30% propylene glycol + 55% distilled water) over time at various subzero temperatures. Viral solutions and disinfectant diluents froze before the mixtures reached −5℃, whereas the AFD was not frozen at −30℃. The times taken for the AFD to reach −10, −20, −30, and −40℃ from room temperature were 36, 39, 45, and 48 min, respectively.

Conditions for the disinfectant efficacy test under subzero temperatures

To establish appropriate conditions for a disinfectant efficacy test at subzero temperatures, this study examined mixtures of frozen foot-and-mouth disease virus or avian influenza virus solutions and disinfectant diluents at −5℃ and monitored temperature and freezing status of an anti-freezing diluent (AFD, 15% ethanol + 30% propylene glycol + 55% distilled water) over time at various subzero temperatures. Viral solutions and disinfectant diluents froze before the mixtures reached −5℃, whereas the AFD was not frozen at −30℃. The times taken for the AFD to reach −10, −20, −30, and −40℃ from room temperature were 36, 39, 45, and 48 min, respectively.

Withdrawal: Protective effects of cultured and fermented ginseng extracts against scopolamine-induced memory loss in a mouse model / 한국실험동물학회지

The reason why the author withdraw the paper is a controversy on intellectual property rights between JIBiopharm Inc. and Hoseo University.

Erratum: Protective effects of cultured and fermented ginseng extracts against scopolamine-induced memory loss in a mouse model / 한국실험동물학회지

In the Materials and Methods section, material supply source is incorrectly cited and has been changed upon request of authors.

Tannic acid-mediated immune activation attenuates Brucella abortus infection in mice

Brucellosis is an emerging infectious disease affecting humans and animals. In this study, we investigated the in vitro and in vivo effects of tannic acid (TA) against Brucella abortus infection. After infection, F-actin polymerization and mitogen-activated protein kinases (MAPKs) (ERK 1/2 and p38α) phosphorylation were reduced in TA-treated cells compared with that in control cells. The mice were infected via an intraperitoneal route and were orally given TA or phosphate-buffered saline for 14 days. Spleen weights of the TA-treated and control mice were not different; however, splenic proliferation of B. abortus was significantly reduced in the TA-treated group. Immune response analysis showed that, compared with the control group, non-infected TA-treated mice displayed increased levels of interferon-γ (IFN-γ), monocyte chemoattractant protein-1 (MCP-1), and interleukin-10 at 3 days post-infection and a further increase in IFN-γ and MCP-1 at 14 days post-infection. In contrast, compared with the control group, infected TA-treated mice displayed elevated levels of IFN-γ at 3 days post-infection, which continued to increase at 14 days post-infection, as was also observed for tumor necrosis factor. Taken together, the results showing TA activation of cytokine production and inhibition of bacterial proliferation in the host highlight a potential use of TA treatment in the control of Brucella infection.

The effect of near-infrared fluorescence conjugation on the anti-cancer potential of cetuximab / 한국실험동물학회지

This study investigated the anti-cancer potential of a near-infrared fluorescence (NIRF) molecule conjugated with Cetuximab (Cetuximab-NIRF) in six-week-old female BALB/c athymic (nu+/nu+) nude mice. A431 cells were cultured and injected into the animals to induce solid tumors. Paclitaxel (30 mg/kg body weight (BW)), Cetuximab (1 mg/kg BW), and Cetuximab-NIRF (0.25, 0.5 and 1.0 mg/kg BW) were intraperitoneally injected twice a week into the A431 cell xenografts of the nude mice. Changes in BW, tumor volume and weight, fat and lean mass, and diameter of the peri-tumoral blood vessel were determined after two weeks. Tumor volumes and weights were significantly decreased in the Cetuximab-NIRF (1 mg/kg BW) group compared with the control group (P < 0.001). Lean mass and total body water content were also conspicuously reduced in the Cetuximab-NIRF (1 mg/kg BW) group compared with the vehicle control group. Peri-tumoral blood vessel diameters were very thin in the Cetuximab-NIRF groups compared with those of the paclitaxel group. These results indicate that the conjugation of Cetuximab with NIRF does not affect the anti-cancer potential of Cetuximab and NIRF can be used for molecular imaging in cancer treatments.

Protective effects of cultured and fermented ginseng extracts against scopolamine-induced memory loss in a mouse model / 한국실험동물학회지

This study was performed to investigate the effect of a concentrate of fermented wild ginseng root culture (HLJG0701) on memory improvement in the scopolamine (SPL)-induced memory-deficient mouse model. Eight-week-old male ICR mice were used to evaluate the protective effect of HLJG0701 against the SPL-induced memory loss animal model. The Morris water maze test, which measures hippocampus-dependent learning ability, and the Y-maze test, a short-term memory assessment test, were performed and related markers were analyzed. HLJG0701-treated groups displayed significantly reduced acetylcholinesterase activity and increased acetylcholine level compared with the SPL-administered group (SPL-G) (P < 0.05). In the Y-maze test, the spontaneous alternation in al HLJG0711-treated groups was significantly increased compared with that in SPL-G (P < 0.05). In the Morris water maze test, the escape latency and time spent in the target quadrant in all HLJG0701-treated groups were significantly decreased and increased, respectively, compared with those in SPL-G (P < 0.05). In addition, the brain-derived neurotrophic factor level in groups treated with HLJG0701 300 and 600 mg/kg body weight was significantly increased compared with that in SPL-G (P < 0.05). These results suggest that the HLJG0701 may protect against memory loss by inhibiting acetylcholinesterase activity and preventing acetylcholine deficiency.

Effects of dietary acetaminophen and vitamin C supplement on serum cortisol and tumor necrosis factor-alpha concentrations in pigs vaccinated with foot-and-mouth disease vaccine

This study evaluated the effect of a combination of acetaminophen and vitamin C (CAV) on reducing serum cortisol and tumor necrosis factor-α (TNF-α) concentrations in piglets vaccinated with foot-and-mouth disease (FMD) vaccine. Piglets were vaccinated with FMD vaccine and treated with CAV at concentrations of 0.0, 0.5, 1.0, and 2.0 kg/ton feed (P-CON, AD-1, AD-2, and AD-3, groups, respectively) for 5 days post-vaccination. Cortisol and TNF-α levels at 5 days post-treatment in the AD-1–3 groups were significantly lower than that in the P-CON group (p < 0.05). There were no significant differences between AD-2 and AD-3 groups and non-vaccinated, non-CAV-treated piglets.

Blood parameter changes in Korean traditional calves and pigs after foot-and-mouth disease vaccination

This study investigated changes in certain blood parameters in calves and pigs after foot-and-mouth disease (FMD) vaccination. In this study, five calves and five pigs were selected from groups of 10 calves and pigs, respectively, and were vaccinated with an FMD vaccine. The remaining animals formed two non-treatment control groups. Blood samples were collected from all animals on the 1st, 3rd, 5th, and 7th days post-vaccination. In the FMD-vaccinated calves and pigs on day 7 post-vaccination, white blood cell counts, blood urea nitrogen levels, and alanine aminotransferase and aspartate aminotransferase activities were higher than those in the respective controls. The present data suggested that the certain hemato-biochemical parameters on cattle and pigs were meaningfully changed between before and after FMD vaccination.

Analysis of antibiotic residues in milk from healthy dairy cows treated with bovine mastitis ointment using ultra-performance liquid chromatography coupled with electrospray tandem mass spectrometry

This study was conducted to analyze penicillin G (PEG), streptomycin (STR) and neomycin (NEO) residues in milk of healthy lactating cows. Milk samples were collected from all four quarters of 12 dairy cows 2–7 days after intramammary infusions of an ointment containing PEG, STR and NEO once (n = 4; group I) or twice (n = 4, group II) daily. Ultra-performance liquid chromatography coupled with electrospray tandem mass spectrometry was used to determine the antibiotic residues in the samples. The correlation coefficient (r 2) of the calibration curves for all antibiotics was > 0.999 and the limits of detection and quantification were 0.002–0.005 µg/mL and 0.007–0.02 µg/mL, respectively. Recovery rates were ranged from 75.5 to 92.3%. In group I, PEG, STR and NEO residues were detected in milk at 2, 3 and 2 days post-treatment, respectively, which were below the maximum residue limit (MRL). In group II, PEG, STR and NEO residues were detected in milk at 2, 3 and 3 days post-treatment, respectively, which were bellow the MRL. These results suggest that a 3-day for milk withdrawal period after the ointment treatment might be sufficient for reduction of the antibiotic residues below the MRL.

Effect of a mixture of Galla rhois and Cinnamomum cassia extracts on susceptibility to the colonization of Campylobacter jejuni in broiler chickens

The present study evaluated the effects of a mixture of Galla rhois and Cinnamomum cassia extracts (GCE) (1 : 1, w/w) on susceptibility to the colonization of Campylobacter (C.) jejuni in broilers. Eighty two-week-old broilers (n = 20 per group) were used to estimate the efficacy of GCE against C. jejuni infection via drinking water. Antibacterial activity testing revealed that the minimum bactericidal concentration of GCE against C. jejuni was 2.5 mg/mL. Broilers challenged with C. jejuni were administered 0.0 (Non-GCE), 2.5 (GCE-2.5), 5.0 (GCE-5.0) and 10.0 g/L (GCE-10) GCE for 7 days, and the cecal contents were collected from five broilers per group on the 1st, 3rd, 5th, and 7th day post-treatment. On day 3 post-administration, the number of C. jejuni in GCE-5.0 (p < 0.05) and GCE-10 (p < 0.01) was significantly decreased relative to Non-GCE, while on day 7 those in all GCE-treated groups were significantly decreased compared to the Non-GCE group (p < 0.001). Hematological and blood biochemical analysis revealed no significant differences in parameters between the Non-GCE and GCE-treated groups. Based on the results of the present study, GCE was identified as a safe and alternative candidate to suppress C. jejuni colonization in broilers.

Evaluation of antibacterial and therapeutic effects of egg-white lysozyme against Salmonella Typhimurium in ICR mice infected with Salmonella Typhimurium

Salmonellosis is a major bacterial zoonosis that causes self-limited enteritis in animals and foodborne disease and typhoid fever in humans. Recently, multi-drug-resistant strains of Salmonella spp. have increased and caused more serious problems in public health. The present study investigated the antibacterial effects of egg-white lysozyme (EWL) against Salmonella (S.) Typhimurium and the therapeutic effects of EWL for murine salmonellosis. Evaluation of the antibacterial effects of EWL against S. Typhimurium revealed a minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of EWL of 6.25 and 300 µg/mL, respectively. In the bacterial growth inhibition test, EWL at 300 (p < 0.05) and 600 µg/mL (p < 0.01) significantly inhibited the growth of S. Typhimurium at 4 h postincubation. EWL administration at MIC (LYS-1), MBC (LYS-2) and 2× MBC (LYS-3) for 14 days resulted in mortality of mice infected with S. Typhimurium of 70, 40 and 10%, respectively, while that of control mice (CON) was 90%. Counts of S. Typhimurium in murine spleens were significantly lower in LYS-2 and LYS-3 than CON (p < 0.05). The results of this study indicate that EWL has the potential for treatment of ICR mice infected with S. Typhimurium.

Inhibitory effect of red ginseng acidic polysaccharide from Korean red ginseng on phagocytic activity and intracellular replication of Brucella abortus in RAW 264.7 cells

Korean red ginseng (KRG) has long been used in traditional Korean and Oriental medicine. However, the anti-bacterial mechanism and therapeutic efficiency of KGR for intracellular Brucella infection are still unclear. In this study, the bactericidal activity of Korean red ginseng acidic polysaccharide (RGAP) on Brucella (B.) abortus and its cytotoxic effects on RAW 264.7 cells were evaluated. In addition, B. abortus internalization and intracellular replication in macrophages were investigated after RGAP treatment. RGAP-incubated cells displayed a marked reduction in the adherence, internalization and intracellular growth of B. abortus in macrophages. Furthermore, decreased F-actin fluorescence was observed relative to untreated B. abortus-infected cells. Western blot analysis of intracellular signaling proteins revealed reduced ERK, JNK and p38α phosphorylation levels in B. abortus-infected RGAP-treated cells compared to the control. Moreover, elevated co-localization of B. abortus-containing phagosomes with lysosome-associated membrane protein 1 (LAMP-1) were observed in RGAP-treated cells compared with the control. Overall, the results of this study suggest that RGAP can disrupt phagocytic activity of B. abortus via suppression of mitogen-activated protein kinases (MAPKs) signaling proteins ERK, JNK and p38 levels and inhibit intracellular replication of B. abortus by enhancing phagolysosome fusion, which may provide an alternative control of brucellosis.

Influence of various photoperiods on stress hormone production, immune function, and hematological parameters in ICR mice / 대한수의학회지

In the present study, the effects of different photoperiods on stress, immunity, and hematological parameters in ICR mice were evaluated. Fifty male ICR mice 7 weeks old (body weight, 27.3 +/- 2.5 g) were divided into five groups: DP-0 (0/24-h light/dark cycle), DP-6 (6/18-h light/dark cycle), DP-12 (12/12-h light/dark cycle), DP-18 (18/ 6-h light/dark cycle), and DP-24 (24/0-h light/dark cycle). During the experimental period, no significant differences in body weight or feed intake were observed between the groups. Hematological analysis revealed that white blood cell, red blood cell, and hemoglobin values for the DP-0 group were significantly different compared to those of the other groups. After 28 days, no significant difference in serum cortisol concentration was observed among the groups, but serum cortisol levels increased in a light exposure-dependent manner. Total serum immunoglobulin G (IgG) concentrations of the DP-0 and PD-6 groups were significantly increased compared to those of the other groups (P < 0.05), and serum total IgG levels decreased in a light exposure-dependent manner. Results of the present study indicated that various photoperiods affect hematological parameters and total serum IgG levels in ICR mice while having no significant effects on body weight, feed intake, or cortisol levels.