specific pathogen free egg and the MDCK-Sky3851 cell line up to 15 passage, and the changes in the antigen sequence of the influenza viruses were confirmed by gene sequencing and protein structure analysis.RESULTS: In term of the hemagglutination titer of influenza virus, the reactivity to chicken and guinea pig red blood cell showed different results between egg propagated and cell propagated viruses. In the sequence analysis results for hemagglutinin and neuraminidase, no antigenic mutation was observed throughout all passages when cultured in MDCK-Sky3851 cells. On the other hand, mutations occurred in three amino acid sequences (H156R, G186S, S219F) in hemagglutinin up to 15 passages when cultured in eggs.CONCLUSION: H3N2 influenza virus cultured in eggs could lead mutations in amino acid sequence of hemagglutinin, distinct from the corresponding virus cultured in cells for which no antigenic mutation was observed. These findings suggest that cell culture is a more stable and effective way of production with lower risk of antigenic mutations for the manufacture of influenza vaccines.]]>
Amino Acid Sequence ; Animals ; Cell Culture Techniques ; Cell Line ; Chickens ; Eggs ; Erythrocytes ; Guinea Pigs ; Hand ; Hemagglutination ; Hemagglutinins ; Humans ; Influenza Vaccines ; Influenza, Human ; Neuraminidase ; Orthomyxoviridae ; Ovum ; Sequence Analysis ; Specific Pathogen-Free Organisms

Animals ; Chemical and Drug Induced Liver Injury ; drug therapy ; Diabetes Mellitus, Experimental ; drug therapy ; Diabetes Mellitus, Type 2 ; drug therapy ; Dyslipidemias ; drug therapy ; Glycemic Load ; drug effects ; Male ; Protective Agents ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Specific Pathogen-Free Organisms ; Stilbenes ; pharmacology

Occupational exposure to 1-bromopropane (1-BP) induces learning and memory deficits. However, no therapeutic strategies are currently available. Accumulating evidence has suggested that N-methyl-D-aspartate receptors (NMDARs) and neuroinflammation are involved in the cognitive impairments in neurodegenerative diseases. In this study we aimed to investigate whether the noncompetitive NMDAR antagonist MK801 protects against 1-BP-induced cognitive dysfunction. Male Wistar rats were administered with MK801 (0.1 mg/kg) prior to 1-BP intoxication (800 mg/kg). Their cognitive performance was evaluated by the Morris water maze test. The brains of rats were dissected for biochemical, neuropathological, and immunological analyses. We found that the spatial learning and memory were significantly impaired in the 1-BP group, and this was associated with neurodegeneration in both the hippocampus (especially CA1 and CA3) and cortex. Besides, the protein levels of phosphorylated NMDARs were increased after 1-BP exposure. MK801 ameliorated the 1-BP-induced cognitive impairments and degeneration of neurons in the hippocampus and cortex. Mechanistically, MK801 abrogated the 1-BP-induced disruption of excitatory and inhibitory amino-acid balance and NMDAR abnormalities. Subsequently, MK801 inhibited the microglial activation and release of pro-inflammatory cytokines in 1-BP-treated rats. Our findings, for the first time, revealed that MK801 protected against 1-BP-induced cognitive dysfunction by ameliorating NMDAR function and blocking microglial activation, which might provide a potential target for the treatment of 1-BP poisoning.
Animals ; Brain ; drug effects ; metabolism ; pathology ; Cognitive Dysfunction ; drug therapy ; metabolism ; pathology ; Disease Models, Animal ; Dizocilpine Maleate ; pharmacology ; Excitatory Amino Acid Antagonists ; pharmacology ; Hydrocarbons, Brominated ; Inflammasomes ; drug effects ; metabolism ; Male ; Maze Learning ; drug effects ; physiology ; Microglia ; drug effects ; metabolism ; pathology ; NLR Family, Pyrin Domain-Containing 3 Protein ; metabolism ; Neurons ; drug effects ; metabolism ; pathology ; Nootropic Agents ; pharmacology ; Random Allocation ; Rats, Wistar ; Receptors, N-Methyl-D-Aspartate ; antagonists & inhibitors ; metabolism ; Spatial Memory ; drug effects ; physiology ; Specific Pathogen-Free Organisms

The oral microbiota is associated with oral diseases and digestive systemic diseases. Nevertheless, the causal relationship between them has not been completely elucidated, and colonisation of the gut by oral bacteria is not clear due to the limitations of existing research models. The aim of this study was to develop a human oral microbiota-associated (HOMA) mouse model and to investigate the ecological invasion into the gut. By transplanting human saliva into germ-free (GF) mice, a HOMA mouse model was first constructed. 16S rRNA gene sequencing was used to reveal the biogeography of oral bacteria along the cephalocaudal axis of the digestive tract. In the HOMA mice, 84.78% of the detected genus-level taxa were specific to the donor. Principal component analysis (PCA) revealed that the donor oral microbiota clustered with those of the HOMA mice and were distinct from those of specific pathogen-free (SPF) mice. In HOMA mice, OTU counts decreased from the stomach and small intestine to the distal gut. The distal gut was dominated by Streptococcus, Veillonella, Haemophilus, Fusobacterium, Trichococcus and Actinomyces. HOMA mice and human microbiota-associated (HMA) mice along with the GF mice were then cohoused. Microbial communities of cohoused mice clustered together and were significantly separated from those of HOMA mice and HMA mice. The Source Tracker analysis and network analysis revealed more significant ecological invasion from oral bacteria in the small intestines, compared to the distal gut, of cohoused mice. In conclusion, a HOMA mouse model was successfully established. By overcoming the physical and microbial barrier, oral bacteria colonised the gut and profiled the gut microbiota, especially in the small intestine.
Animals ; Bacteria ; Gastrointestinal Microbiome ; Germ-Free Life ; Humans ; Mice ; Microbiota ; RNA, Ribosomal, 16S

OBJECTIVEThe present study was undertaken to evaluate the subchronic toxicity of lanthanum and to determine the no observed adverse effect level (NOAEL), which is a critical factor in the establishment of an acceptable dietary intake (ADI).

METHODSIn accordance with the Organization for Economic Co-operation and Development (OECD) testing guidelines, lanthanum nitrate was administered once daily by gavage to Sprague-Dawley (SD) rats at dose levels of 0, 1.5, 6.0, 24.0, and 144.0 mg/kg body weight (BW) per day for 90 days, followed by a recovery period of 4 weeks in the 144.0 mg/kg BW per day and normal control groups. Outcome parameters were mortality, clinical symptoms, body and organ weights, serum chemistry, and food consumption, as well as ophthalmic, urinary, hematologic, and histopathologic indicators. The benchmark dose (BMD) approach was applied to estimate a point of departure for the hazard risk assessment of lanthanum.

RESULTSSignificant decreases were found in the 144.0 mg/kg BW group in the growth index, including body weight, organ weights, and food consumption. This study suggests that the NOAEL of lanthanum nitrate is 24.0 mg/kg BW per day. Importantly, the 95% lower confidence value of the benchmark dose (BMDL) was estimated as 9.4 mg/kg BW per day in females and 19.3 mg/kg BW per day in males.

CONCLUSIONThe present subchronic oral exposure toxicity study may provide scientific data for the risk assessment of lanthanum and other rare earth elements (REEs).

Animals ; Blood Chemical Analysis ; Body Weight ; Dose-Response Relationship, Drug ; Drug Administration Schedule ; Female ; Lanthanum ; administration & dosage ; toxicity ; Male ; No-Observed-Adverse-Effect Level ; Rats ; Rats, Sprague-Dawley ; Specific Pathogen-Free Organisms ; Toxicity Tests, Subchronic ; Urinalysis

Fowl adenovirus (FAdV) is distributed worldwide and causes economic losses in the poultry industry. The objectives of this study were to determine the hexon and fiber gene changes in an attenuated FAdV isolate from Malaysia in specific pathogen-free chicken embryonated eggs (SPF CEE) and its infectivity in commercial broiler chickens. SPF CEE were inoculated with 0.1 mL FAdV inoculum via the chorioallantoic membrane (CAM) for 20 consecutive passages. The isolate at passage 20 (E20), with a virus titer of 10(8.7)TCID₅₀/mL (TCID₅₀, 50% tissue culture infective dose), was inoculated (0.5 mL) into one-day-old commercial broiler chicks either via oral or intraperitoneal routes. The study demonstrated that 100% embryonic mortality was recorded from E2 to E20 with a delayed pattern at E17 onwards. The lesions were confined to the liver and CAM. Substitutions of amino acids in the L1 loop of hexon at positions 49 and 66, and in the knob of fiber at positions 318 and 322 were recorded in the E20 isolate. The isolate belongs to serotype 8b and is non-pathogenic to broiler chickens, but it is able to induce a FAdV antibody titer. It appears that molecular changes in the L1 loop of hexon and the knob of fiber are markers for FAdV infectivity.
Adenoviridae ; Amino Acids ; Chickens ; Chorioallantoic Membrane ; Eggs ; Fowl adenovirus A ; Liver ; Malaysia ; Mortality ; Ovum ; Poultry ; Serogroup ; Specific Pathogen-Free Organisms ; Viral Load

OBJECTIVEThe effect of the silica nanoparticles (SNs) on lungs injury in rats was investigated to evaluate the toxicity and possible mechanisms for SNs.

METHODSMale Wistar rats were instilled intratracheally with 1 mL of saline containing 6.25, 12.5, and 25.0 mg of SNs or 25.0 mg of microscale SiO2 particles suspensions for 30 d, were then sacrificed. Histopathological and ultrastructural change in lungs, and chemical components in the urine excretions were investigated by light microscope, TEM and EDS. MDA, NO and hydroxyproline (Hyp) in lung homogenates were quantified by spectrophotometry. Contents of TNF-α, TGF-β1, IL-1β, and MMP-2 in lung tissue were determined by immunohistochemistry staining.

RESULTSThere is massive excretion of Si substance in urine. The SNs lead pulmonary lesions of rise in lung/body coefficients, lung inflammation, damaged alveoli, granuloma nodules formation, and collagen metabolized perturbation, and lung tissue damage is milder than those of microscale SiO2 particles. The SNs also cause increase lipid peroxidation and high expression of cytokines.

CONCLUSIONThe SNs result into pulmonary fibrosis by means of increase lipid peroxidation and high expression of cytokines. Milder effect of the SNs on pulmonary fibrosis comparing to microscale SiO2 particles is contributed to its elimination from urine due to their ultrafine particle size.

Air Pollutants ; toxicity ; Animals ; Dose-Response Relationship, Drug ; Lung ; drug effects ; pathology ; ultrastructure ; Male ; Microscopy, Electron, Transmission ; Nanoparticles ; toxicity ; Pulmonary Fibrosis ; chemically induced ; metabolism ; pathology ; Random Allocation ; Rats ; Rats, Wistar ; Silicon Dioxide ; toxicity ; Specific Pathogen-Free Organisms ; Spectrometry, X-Ray Emission ; Urine ; chemistry

In Korea, several outbreaks of low pathogenic AI (H9N2) viral infections leading to decreased egg production and increased mortality have been reported on commercial farms since 1996, resulting in severe economic losses. To control the H9N2 LPAI endemic, the Korea Veterinary Authority has permitted the use of the inactivated H9N2 LPAI vaccine since 2007. In this study, we developed a killed vaccine using a low pathogenic H9N2 AI virus (A/chicken/Korea/ADL0401) and conducted safety and efficacy tests in commercial layer farms while focusing on analysis of factors that cause losses to farms, including egg production rate, egg abnormality, and feed efficiency. The egg production rate of the control group declined dramatically 5 days after the challenge. There were no changes in feed consumption of all three groups before the challenge, but rates of the control declined afterward. Clinical signs in the vaccinated groups were similar, and a slight decline in feed consumption was observed after challenge; however, this returned to normal more rapidly than the control group and commercial layers. Overall, the results of this study indicate that the safety and efficacy of the vaccine are adequate to provide protection against the AI field infection (H9N2) epidemic in Korea.
Animals ; Chickens ; Emulsions ; Female ; Influenza A Virus, H9N2 Subtype/*immunology ; Influenza Vaccines/*immunology/*standards ; Influenza in Birds/immunology/prevention & control ; Oviparity ; Specific Pathogen-Free Organisms ; Vaccines, Inactivated/immunology

The present study describes the development of DNA vaccines using the hemagglutinin-neuraminidase (HN) and fusion (F) genes from AF2240 Newcastle disease virus strain, namely pIRES/HN, pIRES/F and pIRES-F/HN. Transient expression analysis of the constructs in Vero cells revealed the successful expression of gene inserts in vitro. Moreover, in vivo experiments showed that single vaccination with the constructed plasmid DNA (pDNA) followed by a boost with inactivated vaccine induced a significant difference in enzyme-linked immunosorbent assay antibody levels (p < 0.05) elicited by either pIRES/F, pIRES/F+ pIRES/HN or pIRES-F/HN at one week after the booster in specific pathogen free chickens when compared with the inactivated vaccine alone. Taken together, these results indicated that recombinant pDNA could be used to increase the efficacy of the inactivated vaccine immunization procedure.
Animals ; Antibodies, Viral/blood ; Cercopithecus aethiops ; Chickens ; *HN Protein/genetics/immunology ; Immunogenicity, Vaccine/*immunology ; Newcastle Disease/immunology ; Newcastle disease virus/enzymology/*genetics/immunology ; Specific Pathogen-Free Organisms ; Vaccines, DNA/genetics/*immunology ; Vaccines, Inactivated/immunology ; Vero Cells ; *Viral Fusion Proteins/genetics/immunology ; Viral Vaccines/genetics/*immunology/*standards

In order to observe the effect of the immune and weight of chickens after use the attenuated vaccine with low dose of chicken infectious anemia virus (CIAV). In this study, the effects of low dose of CIAV on the weight of SPF chickens and NDV antibody production were observed by simulated experiments. The results showed that 10 EID50 and 5 EID50 CIAV per plume attenuated NDV vaccines were used to cause the weight loss of SPF chickens. Compared with the use of the non contaminated vaccine group, it has significant difference. And NDV antibody levels compared with the use of the non contaminated groups also decreased after use the vaccine with two doses of CIAV contaminated. It has significant difference. A certain proportion of CIAV antibody positive was detected at the beginning of the second week after use the NDV vaccine with two doses of CIAV contaminated. The detection of a high proportion of CIAV nucleic acid was detected in the first week after the use of a contaminated vaccine. The results of the study demonstrate the effects of CIAV pollution on the production and immune function of SPF chickens, and it is suggested that increasing the detection of viral nucleic acid can help save time and improve the detection rate in the detection of exogenous virus contamination by SPF chicken test method.
Animals ; Antibodies, Viral ; immunology ; Chicken anemia virus ; genetics ; immunology ; physiology ; Chickens ; Circoviridae Infections ; immunology ; veterinary ; virology ; Poultry Diseases ; immunology ; virology ; Specific Pathogen-Free Organisms ; Vaccines, Attenuated ; administration & dosage ; genetics ; immunology