• Journal of Korean Neurosurgical Society
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• 제64권3호
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• pp.386-405
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• 2021

Recent advancements in basic research on the process of secondary neurulation and increased clinical experience with caudal spinal anomalies with associated abnormalities in the surrounding and distal structures shed light on further understanding of the pathoembryogenesis of the lesions and led to the new classification of these dysraphic entities. We summarized the changing concepts of lesions developed from the disordered secondary neurulation shown during the last decade. In addition, we suggested our new pathoembryogenetic explanations for a few entities based on the literature and the data from our previous animal research. Disordered secondary neurulation at each phase of development may cause corresponding lesions, such as failed junction with the primary neural tube (junctional neural tube defect and segmental spinal dysgenesis), dysgenesis or duplication of the caudal cell mass associated with disturbed activity of caudal mesenchymal tissue (caudal agenesis and caudal duplication syndrome), failed ingression of the primitive streak to the caudal cell mass (myelomeningocele), focal limited dorsal neuro-cutaneous nondisjunction (limited dorsal myeloschisis and congenital dermal sinus), neuro-mesenchymal adhesion (lumbosacral lipomatous malformation), and regression failure spectrum of the medullary cord (thickened filum and filar cyst, low-lying conus, retained medullary cord, terminal myelocele and terminal myelocystocele). It seems that almost every anomalous entity of the primary neural tube may occur in the area of secondary neurulation. Furthermore, the close association with the activity of caudal mesenchymal tissue in secondary neurulation involves a wider range of surrounding structures than in primary neurulation. Although the majority of the data are from animals, not from humans and many theories are still conjectural, these changing concepts of normal and disordered secondary neurulation will provoke further advancements in our management strategies as well as in the pathoembryogenetic understanding of anomalous lesions in this area.

• Nutrition Research and Practice
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• 제16권6호
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• pp.700-715
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• 2022

BACKGROUND/OBJECTIVES: Chronic colitis is a risk factor for colorectal cancer (CRC) development in both animals and humans. Previously, we reported that a diet rich in protein (with casein as the protein source) significantly increased the risk of mouse CRC development in a dose-dependent manner. In this study, we investigated the effects of different protein sources on the risk of colitis development. MATERIALS/METHODS: Balb/c mice were divided into 7 experimental groups: 20% casein (20C), 20C-dextran sulfate sodium (DSS), 40% casein-DSS (40CD), 40% whey protein-DSS (40WD), 40% soy protein-DSS (40SD), 40% white meat-DSS (40WMD), and 40% red meat-DSS (40RMD). Mice were fed an experimental diet for 4 wk and received 3% DSS in their drinking water for 6 days during the 4th wk of the experimental period. RESULTS: Compared to other groups, the 40CD group showed the most aggravated colitis with increased disease activity and inflammatory markers. In the 40RMD group, interleukin (IL)-6 levels were the highest among all the groups. The 40SD group showed conflicting effects, for example, elevated mortality and disease activity but decreased nitric oxide (NO) levels. The 40WD group showed attenuated colitis with increased IL-10 levels and decreased NO levels. The 40WMD group showed conflicting effects, including decreased NO levels and elevated fecal lipocalin-2 and IL-6 levels. CONCLUSIONS: These results suggest that, at levels of 40% in the diet, casein and red meat exacerbate colitis, whereas whey protein mitigates it the most effectively.

• The Plant Pathology Journal
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• 제31권3호
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• pp.203-211
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• 2015

Maize is the dominant cereal crop produced in the US. One of the main fungal pathogens of maize is Fusarium verticillioides, the causative agent of ear and stalk rots. Significantly, the fungus produces a group of mycotoxins - fumonisins - on infested kernels, which have been linked to various illnesses in humans and animals. Nonetheless, durable resistance against F. verticillioides in maize is not currently available. In Texas, over 2.1 million acres of maize are vulnerable to fumonisin contamination, but understanding of the distribution of toxigenic F. verticillioides in maize-producing areas is currently lacking. Our goal was to investigate the genetic variability of F. verticillioides in Texas with an emphasis on fumonisin trait and geographical distribution. A total of 164 F. verticillioides cultures were isolated from 65 maize-producing counties. DNA from each isolate was extracted and analyzed by PCR for the presence of FUM1- a key fumonisin biosynthesis gene - and mating type genes. Results showed that all isolates are in fact F. verticillioides capable of producing fumonisins with a 1:1 mating-type gene ratio in the population. To further study the genetic diversity of the population, isolates were analyzed using RAPD fingerprinting. Polymorphic markers were identified and the analysis showed no clear correlation between the RAPD profile of the isolates and their corresponding geographical origin. Our data suggest the toxigenic F. verticillioides population in Texas is widely distributed wherever maize is grown. We also hypothesize that the population is fluid, with active movement and genetic recombination occurring in the field.

• Journal of Microbiology and Biotechnology
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• 제26권7호
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• pp.1173-1181
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• 2016

Salmonella spp. are gram-negative flagellated bacteria that cause a variety of diseases in humans and animals, ranging from mild gastroenteritis to severe systemic infection. To explore development of a potent vaccine against Salmonella infections, the gene encoding outer membrane protein L (ompL) was inserted into the swinepox virus (SPV) genome by homologous recombination. PCR, western blot, and immunofluorescence assays were used to verify the recombinant swinepox virus rSPV-OmpL. The immune responses and protection efficacy of rSPV-OmpL were assessed in a mouse model. Forty mice were assigned to four groups, which were immunized with rSPV-OmpL, inactive Salmonella (positive control), wild-type SPV (wtSPV; negative control), or PBS (challenge control), respectively. The OmpL-specific antibody in the rSPV-OmpL-immunized group increased dramatically and continuously over time post-vaccination, and was present at a significantly higher level than in the positive control group (p < 0.05). The concentrations of IFN-γ and IL-4, which represent Th1-type and Th2-type cytokine responses, were significantly higher (p < 0.05) in the rSPV-OmpL-vaccinated group than in the other three groups. After intraperitoneal challenge with a lethal dose of Salmonella typhimurium CVCC542, eight out of ten mice in the rSPV-OmpL-vaccinated group were protected, whereas all the mice in the negative control and challenge control groups died within 3 days. Passive immune protection assays showed that hyperimmune sera against OmpL could provide mice with effective protection against challenge from S. typhimurium. The recombinant swinepox virus rSPV-OmpL might serve as a promising vaccine against Salmonella infection.

• 대한핵의학회지
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• 제36권1호
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• pp.74-79
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• 2002

In addition to the well-established use of positron emission tomography (PET) in clinical oncology, novel roles for PET are rapidly emerging in the field of gene therapy. Methods for controlled gene delivery to living bodies, made available through advances in molecular biology, are currently being employed in animals for research purposes and in humans to treat diseases such as cancer. Although gene therapy is still in its early developmental stage, it is perceived that many serious illnesses could be treated successfully by the use of therapeutic gene delivery. A major challenge for the widespread use of human gene therapy is to achieve a controlled and effective delivery of foreign genes to target cells and subsequently, adequate levels of expression. As such, the availability of noninvasive imaging methods to accurately assess the location, duration, and level of transgene expression is critical for optimizing gene therapy strategies. Current endeavors to achieve this goal include methods that utilize magnetic resonance imaging, optical imaging, and nuclear imaging techniques. As for PET, reporter systems that utilize genes encoding enzymes that accumulate positron labeled substrates and those transcribing surface receptors that bind specific positron labeled ligands have been successfully developed. More recent advances in this area include improved reporter gene constructs and radiotracers, introduction of potential strategies to monitor endogenous gene expression, and human pilot studies evaluating the distribution and safety of reporter PET tracers. The remarkably rapid progress occurring in gene imaging technology indicates its importance and wide range of application. As such, gene imaging is likely to become a major and exciting new area for future application of PET technology.

• 대한바이러스학회지
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• 제27권2호
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• pp.185-195
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• 1997

Sequence comparison of the RNA-dependent RNA polymerase of human caliciviruses (HuCVs) from Korean children with gastroenteritis revealed significant genetic variation among them. cDNA clones were produced from the HuCVs collected from pediatric population during a period of 1987-1994. The application of reverse transcription-polymerase chain reaction (RT-PCR) using primers directed to the RNA-dependent RNA polymerase region within ORF1 of Norwalk virus (NV) showed that 13.7% of HuCVs yielded PCR products of similar size to the NV prototype, NV8FIIa/68/US, with exceptions of HuCV 185/87/Korea and HuCV 1115/90/Korea. Computer analyses showed that the PCR products had a continuous protein encoding frame on the positive strand, and contained GLPSG and YGDD amino acid motifs at the predicted distance from primers. Alignment of the amino acid sequences of HuCVs with previously published sequences for Snow Mountain agent (SMA), NV, and Sapporo/82/Japan indicated that these strains can be divided into four major genogroups. There were 10 (45%) SMA-like CVs, one (4.5%) NV-like HuCVs, two (9%) Sapporo-like HuCVs, and nine (41%) unidentified HuCVs. This fourth genogroup should be investigated further. HuCV 185/87/Korea and HuCV 1115/90/Korea, Sapporo-like CVs, were genetically distinct from previously characterized HuCVs and more closely related to known animal CVs. One of the animal CV-like strain, HuCV 185/87/Korea, showed nucleotide and amino acid homology of only 67% and 73% with the prototype Sapporo/82/Japan. Further characterization of animal and human CV genomes and studies of possible cross-transmission of CVs from animals to humans are likely to be beneficial in understanding the epidemiology of HuCVs.

• 한국산업보건학회지
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• 제26권2호
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• pp.119-138
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• 2016

Objectives: The purpose of this study is to review size, shape, and crystal structure-dependent toxicity of major metal oxide particles such as silicon dioxide, tungsten trioxide, aluminum oxide, and titanium dioxide as byproducts generated in semiconductor fabrication facility. Methods: To review the toxicity of major metal oxide particles, we used various reported research and review papers. The papers were searched by using websites such as Google Scholar and PubMed. Keyword search terms included '$SiO_2$(or $WO_3$ or $Al_2O_3$ or $TiO_2$) toxicity', 'health effects $SiO_2$(or $WO_3$ or $Al_2O_3$ or $TiO_2$). Additional papers were identified in references cited in the searched papers. Results: In various cell lines and organs of human and animals, cytotoxicity, genotoxicity, hepatoxicity, fetotoxicity, neurotoxicity, and histopathological changes were induced by silicon dioxide, tungsten trioxide, aluminium oxide, and titanium dioxide particles. Differences in toxicity were dependent on the cell lines, organs, doses, as well as the chemical composition, size, surface area, shape, and crystal structure of the particles. However, the doses used in the reported papers were higher than the possible exposure level in general work environment. Oxidative stress induced by the metal oxide particles plays a significant role in the expression of toxicity. Conclusions: The results cannot guarantee human toxicity of the metal oxide particles, because there is still a lack of available information about health effects on humans. In addition, toxicological studies under the exposure conditions in the actual work environment are needed.

• Parasites, Hosts and Diseases
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• 제53권3호
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• pp.345-348
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• 2015

Toxoplasma gondii is a eukaryotic parasite of the phylum Apicomplexa, which infects all warm-blood animals, including humans. In the present study, we examined sequence variation in dense granule 20 (GRA20) genes among T. gondii isolates collected from different hosts and geographical regions worldwide. The complete GRA20 genes were amplified from 16 T. gondii isolates using PCR, sequence were analyzed, and phylogenetic reconstruction was analyzed by maximum parsimony (MP) and maximum likelihood (ML) methods. The results showed that the complete GRA20 gene sequence was 1,586 bp in length among all the isolates used in this study, and the sequence variations in nucleotides were 0-7.9% among all strains. However, removing the type III strains (CTG, VEG), the sequence variations became very low, only 0-0.7%. These results indicated that the GRA20 sequence in type III was more divergence. Phylogenetic analysis of GRA20 sequences using MP and ML methods can differentiate 2 major clonal lineage types (type I and type III) into their respective clusters, indicating the GRA20 gene may represent a novel genetic marker for intraspecific phylogenetic analyses of T. gondii.

• The Plant Pathology Journal
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• 제28권4호
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• pp.357-363
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• 2012

Several species belonging to the Gibberella fujikuroi species (Gf ) complex are commonly associated with rice and corn, not only causing serious diseases, but also producing fumonisins, a group of mycotoxins harmful to animals and humans. To characterize the population structure of the putative fumonisin-producing Gf complex in Korea, we obtained 276 candidate isolates from rice and corn harvested in 2009 and 2010 by diagnostic polymerase chain reaction with several specific primer sets. Phylogenetic trees were constructed using multilocus sequences (combined RPB2 and EF1A, totaling 1.6 kb) from these isolates. Among the 135 isolates from rice, F. fujikuroi (teleomorph: G. fujikuroi; 59.3%) and F. proliferatum (G. intermedia; 13.3%) were predominant, followed by F. concentricum (5.9%). Additionally, twenty-five (18.5%) rice isolates belonged in a distinct subclade of F. commune, a non-member of the Gf complex. In contrast, F. verticillioides was the most predominant species (38.3%) among the 141 corn isolates, and followed by F. fujikuroi (27.7%), F. proliferatum (14.9%), F. subglutinans (7.1%), and F. concentricum (2.8%). A single mating type (MAT1-1) was found predominantly among the Gf complex isolates examined. Possible distinct subclades were detected within the populations of F. fujikuroi and F. proliferatum; however, this needs further confirmation. This is the first reported population-level characterization of putative fumonisin-producing Gf complex associated with rice and corn in Korea.

• Biomolecules & Therapeutics
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• 제27권4호
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• pp.349-356
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• 2019

Behavioral analysis in mice provided important contributions in helping understand and treat numerous neurobehavioral and neuropsychiatric disorders. The behavioral performance of animals and humans is widely different among individuals but the neurobehavioral mechanism of the innate difference is seldom investigated. Many neurologic conditions share comorbid symptoms that may have common pathophysiology and therapeutic strategy. The forced swim test (FST) has been commonly used to evaluate the "antidepressant" properties of drugs yet the individual difference analysis of this test was left scantly investigated along with the possible connection among other behavioral domains. This study conducted an FST-screening in outbred CD-1 male mice and segregated them into three groups: high performers (HP) or the active swimmers, middle performers (MP), and low performers (LP) or floaters. After which, a series of behavioral experiments were performed to measure their behavioral responses in the open field, elevated plus maze, Y maze, three-chamber social assay, novel object recognition, delay discounting task, and cliff avoidance reaction. The behavioral tests battery revealed that the three groups displayed seemingly correlated differences in locomotor activity and novel object recognition but not in other behaviors. This study suggests that the HP group in FST has higher locomotor activity and novelty-seeking tendencies compared to the other groups. These results may have important implications in creating behavior database in animal models that could be used for predicting interconnections of various behavioral domains, which eventually helps to understand the neurobiological mechanism controlling the behaviors in individual subjects.