SciCombinator

Discover the most talked about and latest scientific content & concepts.

Journal: Journal of veterinary science

151

Composite biological and synthetic grafts with progenitor cells offer an alternative approach to auto- or allografts for fracture repair. This study aimed to evaluate osteogenesis of autologous serum-derived albumin (ASA) scaffolds seeded with canine adipose tissue-derived mesenchymal stem cells (Ad-MSCs) in a canine segmental bone defect model. ASA scaffold was prepared with canine serum using cross-linking and freeze-drying procedures. Beta-tricalcium phosphate (β-TCP) was mixed at the cross-linking stage. Ad-MSCs were seeded into the scaffold and incubated for a day before implantation. After 16 weeks, the grafts were harvested for histological analysis. The dogs were divided into five groups: control, ASA scaffolds with and without Ad-MSCs, and ASA scaffolds including β-TCP with and without Ad-MSCs. ASA scaffolds with Ad-MSCs had significantly larger area of increased opacity at the proximal and distal host cortex-implant interfaces in radiographs 16 weeks after implantation compared to the groups with β-TCP (p < 0.05). Histomorphometric analysis showed that ASA scaffolds with Ad-MSCs had significantly more new bone formation than other groups (p < 0.05). These results suggest that Ad-MSCs seeded into ASA scaffolds enhanced osteogenesis in the bone defect model but β-TCP in the ASA scaffold might prevent penetration of the cells required for bone healing.

Concepts: Stem cell, Mesenchymal stem cell, Bone marrow, Stem cells, Adipocyte, Endochondral ossification

138

On December 3, 2014, a type O foot-and-mouth disease (FMD) outbreak occurred in South Korea. Although vaccinations were administered, cases of FMD increased steadily for five months and reached 185 cases by April 2015. Most of the affected animals were pigs, which are vulnerable to vaccinations. The FMD virus belonged to the South-East Asia (SEA) topotype that had been observed three times in Korea from April 2010 to July 2014. However, the virus in December 2014 had a unique difference in a partial deletion of the 5' noncoding region, which had not been seen in the previous SEA topotype isolates that were identified in Korea. Therefore, we inferred that this outbreak was the introduction of a new strain and that South Korea was affected by genetically similar strains of the FMD virus similar to those from neighboring countries.

Concepts: DNA, Gene, Virus, Vaccination, Philippines, Asia, East Asia, Foot-and-mouth disease

136

Appropriate hoof preparation and symmetry are linked to the wellbeing of the horse. Previous studies have shown the efficacy of the pressure plates (PP) in delivering objective biomechanical analysis. We aimed to assess the effect of hoof trimming on hoof biomechanics using a PP. Nine clinically sound Arabian horses were walked across the PP while foot strike was recorded by a digital camera. Kinetic and kinematic parameters were recorded before and after trimming. P values ≤ 0.05 were considered significant. Vertical force (P = 0.026) and contact pressure (P = 0.006), increased after trimming. Stance phase duration (P = 0.006), swing phase duration (P = 0.023) and gait cycle duration (P = 0.007), decreased significantly post-trimming. The observed changes in kinetic and kinematic parameters are related to hoof trimming. The reported results underline the importance of the farriery practice and its effect on hoof biomechanics, which should be considered by farriers and veterinarians.

Concepts: Horse, Biomechanics, Classical mechanics, Velocity, Kinematics, Walking, Horse hoof, Farrier

26

The purpose of the study was to establish normal electroretinogram (ERG) parameters in 56 normal eyes of four common dog breeds in Thailand: Poodle, Labrador Retriever, Thai Ridgeback and Thai Bangkaew. Standard ERGs were bilaterally recorded using a handheld multi-species ERG unit with the ERG-jet lens electrode in 28 dogs under preanesthesia with diazepam, induction with propofol and anesthesia maintenance with isoflurane. There were significant differences in the means of ERG amplitudes and implicit times among the four dog breeds (P<0.05) except for the b-wave implicit time of the photopic 30 Hz flicker response with 3 cd.s/m(2) (P=0.610). Among all breeds, Thai Bangkaew had the longest implicit time (p<0.001) of scotopic low intensity responses, b-wave of scotopic standard intensity responses (3 cd.s/m(2)), a-wave of the higher intensity response (10 cd.s/m(2)) and a-wave of the photopic single flash response (3 cd.s/m(2)). For b/a ratio, only the ratio of the Cone response had a significant difference among dog breeds. This study reported normal ERG parameters in four dog breeds and supported that the breed-specific limits of normality to ERG response are necessary in each clinic and laboratory.

Concepts: Labrador Retriever, Dog, Dog breed, Gun dog, Dog breeds, Progressive retinal atrophy, Golden Retriever, Labradoodle

26

Ischemic stroke was induced by permanent middle cerebral artery occlusion in 9 healthy experimental dogs. The dogs were divided into 3 groups according to survival time and duration of the experimental period: group A (survived only one day), group B (one-week experimental period), group C (two-week experimental period). Neurologic status was evaluated daily. MRI were performed at a predetermined schedule. Concentration of CSF interleukin (IL)-6 was measured serially after ischemic stroke. Postmortem examination was performed in all experimental dogs. Ischemic lesions on gross findings revealed correspondence to lesions on MRI. Histopathological examinations showed variable degrees of cavitation and necrosis due to neuronal cytopathic effects, such as pyknotic nuclei and cytoplasmic shrinkage, were observed on the affected side of the cerebral cortex in all dogs. Immunohistochemistry against IL-6 showed increased positivity in the ischemic lesions. CSF IL-6 concentrations and ischemic lesion volumes at 1 day after ischemic stroke were significantly higher in group A compared to groups B, C. The purpose of this study is to identify time related changese with clinical, MRI, histopathologic, and immunohistochemical findings in canine ischemic stroke. Additionally, the associations of the CSF and tissue levels of IL-6 were related with clinical prognosis.

Concepts: Brain, Pathology, Anatomical pathology, Histology, Magnetic resonance imaging, Cerebral cortex, Temporal lobe, Cerebrum

26

Cows with different IGF-I concentrations showed comparable hepatic growth hormone receptor (GHR) expression. Suppressor of cytokine signaling 2 (SOCS2), a negative regulator of the GHR signal transduction could be responsible for additional blocking of the GHR. The aims were to monitor cows with high vs. low ante partal IGF-I concentrations (groups: IGF-Ihigh vs. IGF-Ilow) and model interrelationships of endocrine endpoints and to measure hepatic SOCS2 expression. Dairy cows (n = 20) were selected on day 240 to 254 after AI. Daily (day -17 until calving) blood samples were drawn and analyzed for IGF-I, GH, insulin, thyroid hormones, estradiol and progesterone. Liver biopsies were taken (d 264 ± 1 after AI and postpartum) to determine mRNA abundance (IGF-I, IGFBP-3,-4,-2, acid labile subunit, SOCS2, deiodinase1, GHR1A). The IGF-I concentration remained different between both groups (p < 0.0001). However, GH concentrations and GHR1A expression were comparable (p > 0.05). Thyroxine levels and hepatic mRNA expression of acid labile subunit were higher in IGF-Ihigh compared to IGF-Ilow cows. Estradiol tended to be higher in the IGF-Ilow group (p = 0.06). The hypothesis that low IGF-I levels are associated with enhanced SOCS2 expression could not be confirmed by the present study.

Concepts: Immune system, Protein, Signal transduction, Insulin, Growth factor, Hormone, Insulin-like growth factor 1, Growth hormone

26

Currently, killed-virus and modified-live porcine reproductive and respiratory syndrome virus (PRRSV) vaccines are used to control PRRS. However, both types of vaccines have inherent drawbacks and the development of novel PRRSV vaccines is urgently needed. Previous studies have suggested that yeast possesses adjuvant activities and has been used as an expression vehicle to elicit immune responses to foreign antigens. In this report, the recombinant Kluyveromyces lactis (K.lactis) expressing GP5 of HP-PRRSV (Yeast-GP5) was generated and the immune responses were analyzed in mice. Our results showed that intestinal mucosal PRRSV-specific sIgA antibody and higher levels of IFN-γ in spleen CD4+ and CD8+ T cells were induced by oral administration of Yeast-GP5. Yeast-GP5 administrated subcutaneously evoked vigorous cell-mediated immunity, and PRRSV-specific lymphocyte proliferation and IFN-γ secretion were detected in splenocytes of mice. These results suggest that Yeast-GP5 might have the potential to be a vaccine candidate for PRRSV in the future.

Concepts: Immune system, Antibody, Bacteria, Vaccination, Immunology, Humoral immunity, Antigen, Cell-mediated immunity

25

Salmonella enterica Gallinarum (SG) causes fowl typhoid, a septicemic disease in avian species. We constructed deletion mutants lacking the stress sigma factor RpoS, the nitric oxide (NO)-detoxifying flavohemoglobin Hmp, and the SsrA/SsrB regulator, to confirm the functions of these genes in SG. Wild-type (WT) SG showed the full function of each gene product, whereas mutants harboring single mutations or a combination of rpoS, hmp, and ssrAB mutations showed hypersusceptibility to H2O2, loss of NO metabolism, and failure of expression of Salmonella pathogenicity island (SPI)-2, respectively. A triple-deletion mutant, SGΔ3 (SGΔrpoSΔhmpΔssrAB), was evaluated for attenuation and protection efficacy in two-week-old Lohmann layer chickens. The SGΔ3 mutant did not cause any mortality after inoculation with either 1 X 10(6) or 1 X 10(8) colony-forming units (CFU) of bacteria. Significantly lower numbers of salmonellae were recovered from the liver and spleen of chickens inoculated with the SGΔ3 mutant compared with the chickens inoculated with WT SG. Chickens vaccinated with SGΔ3 mutant showed complete protection against challenge with virulent SG, comparable to the group vaccinated with a conventional vaccine strain, SG9R. Overall, these results indicate that SGΔ3 could be a promising candidate for a Salmonella live vaccine against fowl typhoid.

Concepts: DNA, Gene, Gene expression, Microbiology, Vaccine, Salmonella enterica, Salmonella, Inoculation

20

The Democratic People’s Republic of Korea (DPRK) is located on the northern part of the Korean Peninsula in East Asia. While tick-borne pathogens of medical and veterinary importance have been reported from China and the Republic of Korea, they have not been reported from the DPRK. To screen for zoonotic tick-borne pathogens in the DPRK, ticks were collected from domestic goats. A total of 292 (27 nymph, 26 male, 239 female) Haemaphysalis longicornis were collected and assayed individually for selected tick-borne pathogens. Using the 16S ribosomal RNA and ITS species-specific nested PCR, a total of 77 (26.4%) were positive for Anaplasma bovis, followed by Bartonella grahamii (15, 5.1%), Anaplasma phagocytophilum (12, 4.1%), Bartonella henselae (10, 3.4%), and Borrelia spp. (3, 1.0%). Using the groEL-based nested PCR, a total of 6 and 1 H. longicornis were positive for B. grahamii and B. henselae. All products were sequenced and demonstrated 100% identity and homology with previously reported sequences from other countries in GenBank. This is the first report of the detection of tick-borne pathogens in the DPRK and suggests that farm animals may act as reservoirs for zoonotic tick-borne pathogens.

Concepts: Ribosomal RNA, East Asia, South Korea, Korea, Republic of China, North Korea, Korean Peninsula, Bartonella henselae

3

Novel subtypes of Asian-origin (Goose/Guangdong lineage) H5 highly pathogenic avian influenza (HPAI) viruses belonging to clade 2.3.4, such as H5N2, H5N5, H5N6, and H5N8, have been identified in China since 2008 and have since evolved into four genetically distinct clade 2.3.4.4 groups (A-D). Since 2014, HPAI clade 2.3.4.4 viruses have spread rapidly via migratory wild aquatic birds and have evolved through reassortment with prevailing local low pathogenicity avian influenza viruses. Group A H5N8 viruses and its reassortant viruses caused outbreaks in wide geographic regions (Asia, Europe, and North America) during 2014-2015. Novel reassortant Group B H5N8 viruses caused outbreaks in Asia, Europe, and Africa during 2016-2017. Novel reassortant Group C H5N6 viruses caused outbreaks in Korea and Japan during the 2016-2017 winter season. Group D H5N6 viruses caused outbreaks in China and Vietnam. A wide range of avian species, including wild and domestic waterfowl, domestic poultry, and even zoo birds, seem to be permissive for infection by and/or transmission of clade 2.3.4.4 HPAI viruses. Further, compared to previous H5N1 HPAI viruses, these reassortant viruses show altered pathogenicity in birds. In this review, we discuss the evolution, global spread, and pathogenicity of H5 clade 2.3.4.4 HPAI viruses.

Concepts: Microbiology, Virus, Influenza, Avian influenza, Bird, Influenza pandemic, Transmission and infection of H5N1, Global spread of H5N1