Guided bone regeneration with beta-tricalcium phosphate and poly L-lactide-co-glycolide-co-epsilon-caprolactone membrane in partial defects of canine humerus

This study was performed to evaluate the effect of beta-tricalcium phosphate and poly L-lactide-co-glycolide-co-epsilon-caprolactone (TCP/PLGC) membrane in the repair of partial bone defects in canine proximal humerus. Three adult mixed-breed dogs were used during the experimental period. The length of the defect was quarter of the full length of humerus, and width of the defect was quarter of middle diameter of the lateral aspect of humerus. The humeri of each dog were divided into treatment (TCP/PLGC) and control groups. The defect was covered with TCP/PLGC membrane in treatment group. To evaluate regeneration of the bone, computerized tomography (CT) and histopathologic examination were performed. The radiopaque lines were appeared at the original defect sites in TCP/PLGC group but below the original site in control at 4th week. Radiopacity and thickness of the defect sites, and radiopaque lines were more increased at 8th week than those of 4th week. Histopathologic findings revealed fibrous connective tissue migration into the defect and the migration inhibited the structure of new cortex to be placed in the original level in control whereas new cortex growth was found in the level of original line in TCP/PLGC group. However, the new cortical bone in the TCP/PLGC group was thinner and less organized than the adjacent intact cortex, and the amount of new cancellous bones were also scanty. The result suggested that TCP/PLGC membrane is a good guided bone regeneration material to restore the original morphology of humerus in partial defect.     

Sargachromenol Isolated from Sargassum horneri Attenuates Glutamate-Induced Neuronal Cell Death and Oxidative Stress through Inhibition of MAPK/NF-κB and Activation of Nrf2/HO-1 Signaling Pathway

Oxidative stress-induced neuronal cell loss is considered to be the major mechanism underlying the pathogenesis of neurodegenerative diseases, which could be induced by a high concentration of glutamate. In this study, sargachromenol (SC) was isolated from a marine brown seaweed Sargassum horneri (S. horneri) and its neuroprotective effects against glutamate-induced oxidative stress in HT22 cells were investigated. An MTT assay was applied to assess the cytotoxicity of the SC, and the efficacies of SC were determined by flow cytometry, an analysis of ROS production, quantitative Real-Time PCR, and the Western blot assay. Our results showed that the pretreatment of SC reduced glutamate-induced apoptosis in HT22 cells via inhibiting the sub-G₁ population, DNA fragmentation, and nuclear condensation, as well as up-regulating anti-apoptotic protein (Bcl-2) and down-regulating apoptotic proteins (Bax, p53, cleaved-PARP, caspase-3, caspase-9, and cytochrome c). Additionally, SC attenuated glutamate-induced oxidative stress by suppressing mitogen-activated protein kinases (MAPKs;ERK, JNK, and p38) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling (IκBα and NF-κB p65), while activating nuclear factor erythroid-2-related factor 2 (Nrf2)/heme oxygenase 1 (HO-1) signaling (Nrf2; HO-1, and NQO-1). Our results suggest that SC could be used as a pharmacological candidate for the prevention and treatment of neurodegenerative diseases.     

Intergeneric hybrids and an amphiploid between Elymus canadensis and Psathyrostachys juncea

Summary Fifty four hybrid plants between Elymus canadensis and Psathyrostachys juncea were obtained by handpollination and embryo culture. The average cross compatibility between both species was 31.2 percent. One amphiploid plant was induced by colchicine treatment. The hybrid and amphiploid plants resembled P. juncea in appearance but showed a higher plant height and dry matter yield than the parents. The hybrids showed extremely low pollen stainability and were completely sterile. With the exception of one plant (2n=3x+1=22), all hybrid plants were allotriploids (SHN, 2n=3x=21). The amphiploid plant (SSHHNN, 2n=6x=42) showed 58.9% pollen stainability and 11.6% seed fertility.Mean chromosome associations of the hybrids and amphiploid at metaphase I were 0.02IV+0.06III+2.03II+16.91I and 0.07III+18.00II+5.85I, respectively. Lagging chromosomes, chromosome bridges, abnormal cytokinesis, and micronuclei were occasionally observed at the anaphase, telophase, or tetrad stage.     

Development of a multiplex PCR assay to detect Edwardsiella tarda,Streptococcus parauberis,and Streptococcus iniae in olive flounder (Paralichthys olivaceus)

A multiplex PCR protocol was established to simultaneously detect major bacterial pathogens in olive flounder (Paralichthys olivaceus) including Edwardsiella (E.) tarda, Streptococcus (S.) parauberis, and S. iniae. The PCR assay was able to detect 0.01 ng of E. tarda, 0.1 ng of S. parauberis, and 1 ng of S. iniae genomic DNA. Furthermore, this technique was found to have high specificity when tested with related bacterial species. This method represents a cheaper, faster, and reliable alternative for identifying major bacterial pathogens in olive flounder, the most important farmed fish in Korea.     

Canine model of ischemic stroke with permanent middle cerebral artery occlusion: clinical and histopathological findings

The aim of the present study was to assess the clinical and histopathological findings in a canine model of ischemic stroke. Cerebral ischemic stroke was induced by middle cerebral artery occlusion in four healthy beagle dogs using silicone plugs. They showed neurological signs of forebrain dysfunction such as reduced responsiveness, head turning, circling, postural reaction deficits, perceptual deficits, and hemianopsia. These signs gradually regressed within 4 weeks without therapy. On magnetic resonance imaging, T2 hyperintensity and T1 hypointensity were found in the cerebral cortex and basal ganglia. These lesions were well-defined and sharply demarcated from adjacent brain parenchyma with a homogenous appearance. No abnormalities of the cerebrospinal fluid were observed. At necropsy, atrophic and necrotic lesions were observed in the cerebral cortex. The cerebral cortex, basal ganglia, and thalamus were partially unstained with triphenyl-tetrazolium chloride. Histopathologically, typical features of infarction were identified in cortical and thalamic lesions. This study demonstrates that our canine model resembles the conditions of real stroke patients.     

Temperature-dependent development and survival of Podisus maculiventris (Hemiptera: Pentatomidae): implications for mass rearing and biological control

The spined soldier bug, Podisus maculiventris (Say), is a generalist predator that can control >75 insect pests in various agroecosystems. Despite valuable results from the previous studies, thermal development and survival of P. maculiventris over a wide range of temperatures had not been elucidated completely. This study was conducted to investigate the stage-specific development and survival of P. maculiventris at eight constant temperatures (13.2, 18.4, 21.7, 23.7, 27.2, 32.7, 35.2, and 40.6 °C) covering the entire thermal range for P. maculiventris development. Completion of egg development was observed at 13.2–32.7 °C, whereas nymphs successfully developed into adults at 18.4–32.7 °C. Survival model using log-normal equations showed bell-shape patterns for all stages, and temperatures resulting in highest survival of P. maculiventris were 19.9, 24.3, and 24.5 °C for egg, nymph, and egg to adult, respectively. Developmental rates at the eight temperatures were fitted with a nonlinear Briere model, which estimated optimal temperatures for development as 31.2, 30.6, and 30.6 °C for egg, nymph, and egg to adult, respectively. Operative thermal ranges (i.e., in-between the lower and upper developmental thresholds) were estimated to be 8.9–35.2, 12.8–35.2, and 12.7–35.2 °C for egg, nymph, and egg to adult, respectively. In a linear model, the lower thresholds were 10.9, 13.1, and 13.0 °C for egg, nymph, and egg to adult, respectively. Findings herein provide comprehensive data and explanations on optimal temperature and thermal requirement for P. maculiventris, which can be used to optimize environmental condition in mass rearing and predicting phenology of P. maculiventris in the field.     

Extraskeletal myxoid chondrosarcoma with systemic metastasis in a five-month-old irish setter dog

Extraskeletal myxoid chondrosarcoma was found in a five-month-old male Irish setter dog. At necropsy, the largest mass, measuring 15 × 13 × 13 cm, was found in the right caudal lobe of the lung, and metastatic small masses were observed in multiple organs. Microscopically, the tumor comprised mainly atypical mesenchymal cells and myxoid stroma, which stained positively with Alcian blue. Immunohistochemically, the tumor cells stained positively for vimentin, S-100 protein, neuron-specific enolase, calretinin, and chromogranin A. Ultrastructurally, the cytoplasm of the tumor cells was comprised abundant rough endoplasmic reticulum, mitochondria, Golgi complex, free ribosomes and short irregular microvillous processes extending from the cytoplasm. Based on these pathological findings, this tumor was diagnosed as extraskeletal myxoid chondrosarcoma.     

Evaluation of dietary natural mineral materials as an antibiotic replacer on growth performance,non‐specific immune responses and disease resistance in rainbow trout,Oncorhynchus mykiss

We evaluated the effects of some dietary natural mineral materials as an antibiotic replacer based on growth performance, non‐specific immune responses and disease resistance in juvenile and subadult rainbow trout, Oncorhynchus mykiss. First experiment, juvenile rainbow trout averaging 2.7 ± 0.02 g (mean ± SD) were fed one of the six experimental diets; a basal commercial diet as a control (CON), CON with oxytetracycline (OTC), with yellow loess (YL), with Macsumsuk^® (MS), with Song‐Gang^® stone (SG) and with barley stone (BS) at 0.4% of each diet. At the end of 8‐week feeding trial, weight gain (WG), specific growth rate (SGR), feed efficiency (FE) and protein efficiency ratio (PER) of fish fed YL diet were significantly higher than those of fish fed CON diet. Non‐specific immune responses such as superoxide dismutase (SOD), myeloperoxidase (MPO), lysozyme (LYS) activity and oxidative radical production of fish fed YL diet were higher than those of fish fed CON diet. At the end of 15 days of challenge test with Aeromonas salmonicida, average cumulative survival rate of fish fed YL diet was significantly higher than that of fish fed BS and CON diets. However, there were no significant differences among fish fed YL, SG and OTC diets. Second experiment, subadult rainbow trout averaging 261.5 ± 3.5 g (mean ± SD) were fed one of the four experimental diets for 22 weeks: CON, and CON with OTC, YL or SG at 0.4% of each diet. At the end of feeding, growth performance of fish fed SG and YL diets was significantly higher than that of fish fed CON diet. Non‐specific immune responses in terms of SOD, MPO, LYS and NBT of fish fed SG and YL diets were significantly higher than those of fish fed CON diet. However, there were no significant differences among the fish fed YL, SG and OTC diets. The results indicate that dietary yellow loess or Song‐gang^® stone at 0.4% of diet could replace oxytetracycline in juvenile and subadult rainbow trout.