• Korean Journal of Veterinary Research
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• v.39 no.2
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• pp.247-256
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• 1999

A disease of young Holstein calves characterized by recurrent pneumonia, ulcerative and granulomatous stomatitis, enteritis with bacterial overgrowth, periodontitis, delayed wound healing, persistent neutrophilia and death at an early age had been originally described in 1983 and again in 1987. Most of these calves had stunted growth and a persistent, progressive neutrophilia (often exceeding 100,000/ml). By investigation of pedigrees, all of the affected calves have now been traced to a common sire and confirmed by polymerase chain reaction (PCR) diagnostic DNA testing to be homozygous carriers of a defective allele for bovine CD18. Neutrophils from these calves have several functional deficits and, most importantly, fail to adhere in a ${\beta}_2$-integrin dependent manner. The ${\beta}_2$-integrins represent a family of glycoproteins which participate in various leukocyte adhesion reactions during host defense. The presence or absence of ${\beta}_2$-integrin molecules can be demonstrated on the surface of neutrophils, monocytes and lymphocytes from normal or affected calves using specific monoclonal antibodies and flow cytometry, or by colloidal gold immunolabeling and scanning electron microscopy in backscatter mode. Deficiency of the ${\beta}_2$-integrins on all leukocyte types in Holstein calves is analogous to leukocyte adhesion deficiency (LAD) seen in humans. Neutrophils in bovine (BLAD) and human LAD patients are unable to adhere to the endothelial lining of the cardiovascular system thus interrupting egression of neutrophils into infected tissues. Other leukocytes, while still deficient in expression of the ${\beta}_2$-integrins, are still able to efficiently egress from the blood stream due to interactions of other adhesion molecules that are not as highly expressed on neutrophils. Both BLAD cattle and LAD children (who do not receive bone marrow transplants) often die at an early age as a result of the failure of neutrophils to extravasate into infected tissues. In 1991, Shuster, et $al^{27}$, identified two point mutations within the alleles encoding bovine CD18 in a Holstein calf afflicted with leukocyte adhesion deficiency. One mutation causes an aspartic acid to glycine substitution at amino acid 128 (D128G) in an extracellular region of this adhesion glycoprotein that is highly conserved (> 95% identity) between humans, cattle and mice. The other mutation is silent. Numerous calves with clinical symptoms of leukocyte adhesion deficiency have since been tested and all have been found homozygous for the D128G allele. In addition, calves homozygous far the D128G allele have been identified during widespread DNA testing in the United States. All cattle with the mutant allele are related to one bull, who through artificial insemination (A.I.), sired many calves in the 1950's and 1960's. The carrier frequency of the D128G CD18 allele among U.S. Holstein cattle had reached approximately 15% among active A.I. bulls and 8% among cows. By 1993, the organization of the dairy industry and the diagnostic test developed to genotype cattle, enabled virtually complete eradication of bovine leukocyte adhesion deficiency among current and future A.I. bulls.

• Journal of the Korean Society of Tobacco Science
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• v.31 no.2
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• pp.69-74
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• 2009

Potato Virus Y (PVY), PVY-vein necrosis strain, causes severe damage at growth, yield and leaf quality on flue-cured tobacco in Korea. The development of PVY resistant flue-cured varieties without quality deterioration is therefore urgently desired. The flue-cured tobacco, KF120 (Korea Flue-cured 120), was a male-sterile (ms) $F_1$ hybrid derived from the cross between msKF117 and KF0007-7. msKF117 was developed from the cross of NC82 with N. africana and KF0007-7 was developed from the cross of KF117 with NC82. The agronomic characteristics and disease resistance of KF120 was evaluated during 2006-2007 field performance test. It showed better growth characteristics and yield performance than standard cultivar KF109. It had 2 more leaves per plant, flowered 2 days later than KF109. The yield of cured leaf of KF120 was increased by about 5% compared to KF109. The chemical composition and physical properties of the cured leaf of KF120 were as much acceptable as those of KF109. KF120 showed high resistance to PVY compared to KF109. It showed a similar mode of resistance to bacterial wilt and black shank as was found in KF109.

• Journal of Microbiology and Biotechnology
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• v.26 no.8
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• pp.1446-1451
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• 2016

Clostridium difficile toxin A causes acute gut inflammation in animals and humans. It is known to downregulate the tight junctions between colonic epithelial cells, allowing luminal contents to access body tissues and trigger acute immune responses. However, it is not yet known whether this loss of the barrier function is a critical factor in the progression of toxin A-induced pseudomembranous colitis. We previously showed that NADH:quinone oxidoreductase 1 (NQO1) KO (knockout) mice spontaneously display weak gut inflammation and a marked loss of colonic epithelial tight junctions. Moreover, NQO1 KO mice exhibited highly increased inflammatory responses compared with NQO1 WT (wild-type) control mice when subjected to DSS-induced experimental colitis. Here, we tested whether toxin A could also trigger more severe inflammatory responses in NQO1 KO mice compared with NQO1 WT mice. Indeed, our results show that C. difficile toxin A-mediated enteritis is significantly enhanced in NQO1 KO mice compared with NQO1 WT mice. The levels of fluid secretion, villus disruption, and epithelial cell apoptosis were also higher in toxin A-treated NQO1 KO mice compared with WT mice. The previous and present results collectively show that NQO1 is involved in the formation of tight junctions in the small intestine, and that defects in NQO1 enhance C. difficile toxin A-induced acute inflammatory responses, presumably via the loss of epithelial cell tight junctions.

• Applied Biological Chemistry
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• v.43 no.3
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• pp.190-195
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• 2000

Tolaasin is a peptide toxin produced by Pseudomonas tolaasii and causes a brown blotch disease forming brown, slightly sunken spots and blotches on the cultivated mushrooms. It is a lipodepsipeptide consisting of 18 amino acids and its molecular mass is 1,985 Da. It forms a pore in plasma membranes, resulting in the disruption of membranes of fungal, bacterial, plant, and animal cells as well as mushroom tissue. In order to measure the toxicity of tolaasin, erythrocytes of blood were used to evaluate the tolaasin-induced hemolysis. Hemolytic activity of tolaasin was measured by observing the absorbance change either at 420 nm, representing the release of hemoglobins from red blood cells(RBCs), or at 600 nm, representing the density of residual cells. The hemolytic activity of culture-extract of P. tolaasii increased at early-stationary phase of growth and was maximal at late stationary phase. The hemolytic activity of tolaasin appeared high in the RBCs of dog and rat. The RBCs of rabbit and hen were less susceptible to tolaasin. The effects of various cations were also measured. $Cd^{2+}$ and $La^{3+}$. as well as $Zn^{2+}$ appeared inhibitory to the tolaasin-induced hemolysis. The effects of various anions on tolaasin-induced hemolysis were measured and carbonate showed the greatest inhibition to the hemolysis. However, phosphate stimulated the tolaasin-induced hemolysis and no effects were observed by chloride and nitrate.

• Journal of fish pathology
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• v.25 no.3
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• pp.271-277
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• 2012

The practical monitoring was performed to survey the mortalities in aquaculture farms of olive flounder, rockfish, rainbow trout, Japanese eel, white shrimp and abalone in South Korea from May to November, 2011. The aquatic organism disease inspectors, who have the national licenses for the diagnosis and prevention of aquatic disease and have close relationship with the farms, investigated the rates and causes of mortalities according to the standard manual. In 70 flounder farms, the cumulative mortalities rate was 27.9%, and the mortalities were caused by scuticociliatosis, streptococcosis, VHS, non-infectious loss, vibriosis and gliding bacterial disease. The moralities rate of 30 rockfish farms was 13.6%, and those were mainly contributed by gill flukes and streptococcosis. Most of mortalities of rainbow trout were caused by non-infectious loss and protozoan white spot disease. The mortalities rate of Japanese eel was 0.6% by edwardsiellosis, protozoan white spot disease and gill flukes. The loss rate of white shrimp was 71.2%, and most of them was related with non-infectious ones, such as carnivalization, transportation loss, and the rest was caused by viral white spot disease. The mortalities rate in the abalone farms was 10.7% and all of them were related with non-infectious loss.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1976.06a
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• pp.85.3-86
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• 1976

Sudden deafness requires immediate investigation and treat if there is to be any prospect of salvaging the hearing. It present an otological emergency and a diagnostic challenge. Sn Sudden sensorineural deafness can be caused by a wide variety of pathologies. A battery of tests and investigations must be performed forthwith if treatment is to be started without further delay. The concept that nothing can be done for the patient with sensori-neural deafness must be abandoned. Some pathologies causing sudden deafness are not amenable to therapy or can show only partial reversibility. But there are several causes, showing little or no spontaneous recovery, which do responed to appropriate treatment. It is important to identify them and concentrate on their management. The age and sex ratios and the unilaterral or bilateral nature of the lesion are related to the etiology and depend upon which type of case is included in the series. Though individually rare, collecting for about 2.5 per cent of new otoloical patients. Some 70 per cent of cases are unilateral. Viral, bacterial and treponemal infections accounted for about 30 per cent of the cases. Some 16 per cent were due to vascular lesions of the cochlea. In almost 22 per cent there was no obvious cause (idiopathic), they occurred in young adult and were either sensory or neural. About 12 per cent were traumatic and 9 per cent were ototoxic in origin. The remaining 11 per cent were due to a group of rarities. The two vital factors are the site of the lesion and the duration of the hearing loss. The earlier these are diagnosed and treated the better the response. The etiology, pathology and treatment are reviewed.

• Journal of Life Science
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• v.31 no.8
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• pp.755-760
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• 2021

Swine diarrhea is a livestock disease that causes huge economic losses to pig farms. In general, diarrhea occurs because of the proliferation of pathogenic Escherichia coli (E. coli). The toxins produced by the proliferated E. coli cause edema in pigs. Although the proliferation of these coliforms can be prevented by using a vaccine, the vaccines containing chemically produced dead bacteria are not very effective, making it difficult to control the proliferation of E. coli. Therefore, there is a need to develop new, more effective vaccines. In this study, we prepared killed F4+ and F18ab+ E. coli, which induce diarrhea and edema in pigs, using the extracts of immune-induced silkworms containing antimicrobial peptides and examined their availability as a killed-bacteria vaccine. First, the antimicrobial activity analysis of the prepared immune-induced silkworm extract was conducted using the radial diffusion assay. The results showed high activity against both F4+ and F18ab+ E. coli. The production efficiency of E. coli dead cells was determined using the colony-counting method. The concentration of the E. coli dead cells was the highest (50 mg/ml) when treated at 4℃. In addition, the analysis of the prepared dead cells using a transmission electron microscope confirmed that E. coli leaked out of the cytoplasm and the cell membrane remained intact. Therefore, F4+ and F18ab+ E. coli produced using immune-induced silkworms extract are considered to be highly available as bacterial ghost vaccines that can help prevent swine diarrhea and the resulting edema.

• Journal of Food Hygiene and Safety
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• v.39 no.2
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• pp.102-108
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• 2024

This study was performed to establish the epidemiological features of a food poisoning outbreak that occurred in the cafeteria of a company in Chungcheongnam-do Province, Korea, in October 2020, and to recommend measures to prevent similar outbreaks. Twenty-one patients with acute gastroenteritis, three food handlers, seven cooking utensils, and 12 preserved food samples were subjected to viral and bacterial analyses based on procedures described in the "Manual for Detection of Foodborne Pathogens at Outbreaks". Among 135 individuals who had been served the meals, 21 (15.6%) showed symptoms of nausea and vomiting within an hour of consuming the food. Bacillus cereus were isolated from 11 (52.4%) of the 21 patients, one food service employee, one item of cooking ware, and 12 preserved food samples. In addition, we confirmed the toxin genes CER, nheA, and entFM from the isolated B. cereus strains. Pulsed-field gel electrophoresis results indicated that all of the isolated B. cereus strains were closely related, with the exception of strains obtained from one patient and one sample of preserved food. These findings provide evidence to indicate that the isolated B. cereus originated from preserved foods and an unhygienic eating environment. This outbreak highlights that the provision of food in non-commercial food systems must be thoroughly managed. In addition, it emphasizes the necessity for the correct and timely identification of causal pathogens for tracing the cause of food poisoning outbreaks, and the need to preserve food under appropriate conditions. To prevent similar cases of food poisoning, it is necessary to investigate cases based on an epidemiological approach and share the findings.

• Journal of Ginseng Culture
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• v.6
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• pp.51-79
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• 2024

In the 1970s and 1980s, during the nascent phase of ginseng disease research, efforts concentrated on isolating and identifying pathogens. Subsequently, their physiological ecology and pathogenesis characteristics were scrutinized. This led to the establishment of a comprehensive control approach for safeguarding major aerial part diseases like Alternaria blight, anthracnose, and Phytophthora blight, along with underground part diseases such as Rhizoctonia seedling damping-off, Pythium seedling damping-off, and Sclerotinia white rot. In the 1980s, the sunshade was changed from traditional rice straw to polyethylene (PE) net. From 1987 to 1989, focused research aimed at enhancing disease control methods. Notably, the introduction of a four-layer woven P.E. light-shading net minimized rainwater leakage, curbing Alternaria blight occurrence. Since 1990, identification of the bacterial soft stem rot pathogen facilitated the establishment of a flower stem removal method to mitigate outbreaks. Concurrently, efforts were directed towards identifying root rot pathogens causing continuous crop failure, employing soil fumigation and filling methods for sustainable crop land use. In 2000, adapting to rapid climate changes became imperative, prompting modifications and supplements to control methods. New approaches were devised, including a crop protection agent method for Alternaria stem blight triggered by excessive rainfall during sprouting and a control method for gray mold disease. A comprehensive plan to enhance control methods for Rhizoctonia seedling damping-off and Rhizoctonia damping-off was also devised. Over the past 50 years, the initial emphasis was on understanding the causes and control of ginseng diseases, followed by refining established control methods. Drawing on these findings, future ginseng cultivation and disease control methods should be innovatively developed to proactively address evolving factors such as climate fluctuations, diminishing cultivation areas, escalating labor costs, and heightened consumer safety awareness.

• Korean Journal of Veterinary Service
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• v.24 no.3
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• pp.223-241
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• 2001

From September 1996 to September 1999, 419 Korean-native calves with diseases under 6-month old collected from Kyonggi, Chungcheong, Chonlla and Kyongsang were examined by clinical, microbiological, parasitic, hematologic and histopathological mean. Among them, 124 cases were tested about the neutralization antibodies against infectious bovine rhinotracheitis virus(IBRV), Parainfluenza-3 virus(PI-3V), bovine uiral diarrhea virus(BVDV), bovine ephemeral fever virus(BEFV). In calf diseases in the survey, enteric diseases(72.8%) were most frequently involved and the following orders were taken by respiratory(17.4%) and reproductive (5.0%) disorders. In the causative pathogens associated with calf diseases and motality, 48.4% was induced by bacteria origin and also 35.6% by viral agents. Calf mortality was up to 76.3% in the cae of bacterial diseases and 55.7% in viral diseases. In bacterial diseases, frequent disorders were composed of colibacillosis(52.7%), salmonellosis(13.8%), pasteurellosis(12.8%) and campylobacteriosis(3.9%) and their mortalities showed 73.8% in colibacillosis, 73.0% in pasteurellosis, 67.9% in salmonellosis and 50.0% in campylobacteriosis (50.0%). Among the outbreaks of viral diseases, there were BVD(22.8%), bovine rotavirus infection(20.8%), bovine coronavirus infection(16.8%), bovine respiratory syncytial virus infection(15.4%), IBR(15.4%). Akabane disease(4.7%) and Chuzan diseases(3.4%). Interesting results through this studies were obtained the first isolate to Chuzan virus and Ainovirus in Korea which could be promised the development for diagnostic method and vaccines soon. Calf mortality to Akabane and Chuzan diseases was 100%. Main parasitic diseases were occupied by coccidiosis and babesiosis and their mortality of babesiosis was 20.0%. Other diseases were abomasal impaction(6.7%) and toxicosis(4.5%). The mortality of abomasal impaction was 89.3%. In some causes with malformations(1.9%) were confirmed as anasarca, derodidymus, polymelia, humerus hypoplasia, and tracheal collapse. Calf diseases had mostly been occurred in one month old grout (52.5%) and its prevalence was 25.1% in two to three month old group and 22.4% in four to six month old group. In calf mortality by age, there were 37.9% in one month old group, 18.1% in two and three month old group, and 13.8% in four to six month old group, respectively. The older the age of calf, the less the prevalence of calf enteric diseases. Respiratory diseases in calves to be tested frequently occurred in one to two month old group (41.4%). In one month old calves, the prevalence of enteric disease was 80.0%(p<0.05) and that of reproductive and respiratory disease was 9.5% and 8.2%, respectively. In two month old and four to six month old, enteric disease was 65.7% and 63.8% and respiratory disease was 28.6% and 26.6%. Seasonal prevalence and mortality of Korean-native calf diseases were not a significant difference. Prevalence of calf diseases in summer(31.5%) frequently occurred to compare that in winter(20.3%). Abortion and malformation in calves frequently occurred in spring. Hematological values in 84 calves with clinical signs showed mild to marked leukocytosis. Also, there was slight increase in hematocrit, platelet, mean corpuscular volume and mean plasma volume, but all of those were included the higher level to normal ranges. Calves with respiratory signs showed slightly erythrocytosis. One hundred seventy three calves without clinical signs were not significant different to ill cases in hematological values, but number of platelets was in higher normal range. In 125 calves, 84.8% was taken the antibody to IBRV, but 72% with the antibody had recorded the titer level lower than log$_2$5. The neutralizing antibody levels of higher than $log_{2}5$ to PI-3V and BVD virus were 60.8% and 67.2% cases, respectively. There were the cases of 57.6% had the neutralizing antibody level lower than log$_2$5 to BEFV.