• 대한수의학회지
• /
• 제24권1호
• /
• pp.78-82
• /
• 1984

This study was undertaken to investigate congenital microphthalmia occurred at a pig farm in Gyeongbug province. These microphthalmic piglets composed of 20 piglets farrowed by three different sows(1, 11 and 8 piglets by No.1, 2 and 3 sow, respectively) that were apparently normal during pregnancy and after parturition. Attempts were made to know epidemiological findings and histopathological changes of these piglets and the results were summarized as follows; 1. One piglet from No. 1 sow exhibited staggering and incoordination and remained alive, but 19 piglets from No. 2 and 3 sow died between 3 and 20 minutes after birth. 2. In histopathological finding, hypoplasia and edema of all organs were observed in all piglets, and significant of lesions related to infection of microrganisms were not observed. 3. The cause of microphthalmia was considered as hypovitaminosis A in the sown intaked only barley barn before and during early pregnancy.

• 한국축산시설환경학회지
• /
• 제6권2호
• /
• pp.97-104
• /
• 2000

This study was carried out to determine the effects of different weaning age on feeding performance and behaviour of piglets. Sixty crossbred(YLxD) litters of piglets were randomly alloted to be 15 pens with 4 piglets per pen and 5 pens per treatment by weaned at 14, 21, and 28 days. Pens were video-taped for 24 hours immediately at 7 weeks and 8 weeks of age. The piglets weaned at 14 and 21 days were significantly (P<0.05) much intake than piglets weaning at 28 days. The piglets weaning at 14 days were significantly lighter than piglets weaning at 14 and 21 days fro m2 weeks to 8 weeks age. However, feed conversion ration was significantly(P<0.05) improved according to late weaning days. Times spent engaged in Feeding, lying and walking were similar in piglets across weaning age. They also showed similar occurrence of drinking and agonistic behaviour at 7 weeks and 8 weeks of age. Piglets weaned at 14 days exhibited more belly-nosing behaviour at 7 weeks of age, but similar in piglets at 8 weeks of age across weaning age. We concluded that piglets performance influenced by weaning day, however time spent for feeding, lying and walking behaviour were no significance. Drinking, Agonistic and belly-nosing were not significantly different by weaning age.

• 한국축산시설환경학회지
• /
• 제1권1호
• /
• pp.1-8
• /
• 1995

Litters such as sawdust and rice hulls are used to manage the waste excrements of Hanwoo(Korean Native Cattle). This experiment was conducted to investigate the adequate depth of bedding materials, and the effective substitutive rate of rice hulls and the recycled-dried sawdust mixed with cattle waste for sawdust from 1993 to 1994. The results were as follows; 1. The most adequate bedding depth of sawdust was 4cm and it was able to be utilized for 38 days. The cost of required sawdust was lower in order of 5, 15, 20 and 10cm in depth of bedding sawdust. 2. Rice hulls was able to be fully substituted for sawdust, but 50% substitution the most effective. 3. Recycled-dried sawdust mixed with cattle waste could be substituted less than 25% for sawdust.

• Toxicological Research
• /
• 제17권3호
• /
• pp.163-165
• /
• 2001

A patient,58 years of age, with suspected 0/l pneumoconiosis since 1993, complained of a dry cough and exertioning dyspnea for 6 months. He had worked in an asbestos company for more than 20 years from 1974. He was subsequently diagnosed with an interstitial lung disease during an annual special health check-up for asbestos workers. h chest X-ray showed an interstitial lung disease and high-resolution computed tomography (HRCT) showed a round opaque asbestosis with chronic hypersensitivity pneumonitis. A pulmonary function test indicated that the patient had a mild restrictive lung disease with FEV1 1.67 litters and 82% FEVl/FVC. The bronchoalveloar larvage fluid included many asbestos bodies, indicating previous exposure to asbestos. Transmission electron microscopy (TEM) using an energy dispersive X-ray analyzer (EDX) revealed many asbestos bodies consisting of mainly crocidolite fibers (6,071$\times$$10^6$fibers/g of dry lung). The patient had an unusually high asbestos content of 6,112$\times$$10^6$ asbestos fibers/9 of dry lung.

• 대한수의학회지
• /
• 제26권2호
• /
• pp.251-257
• /
• 1986

Isolation of Staphylococcus hyicus subsp. hyicus from piglets suffering from exudative epidermitis and healthy pigs was performed, and some properties of the isolates were examined. Twentry-six litters of exudative epidermitis observed in the field were sucking piglets with ages ranging from 1 to 5 weeks and most (73.1%) of these cases occurred in piglets between 2 and 3 weeks of age. Staphylococcus hyicus subsp. hyicus was isolated front 192(38.9%) of 494 healthy pigs. The rate of isolation of these organism from healthy pigs was found to vary greatly among farms at an isolation rate of 33.3% to 45.5% and this organism was isolated more frequently front sucking piglets below the age of 8 weeks than adult pigs. All of the isolates originated from the diseased and healthy pigs were positive in heat-stable DNase, Tween 80 hydrolysis, gelatinase, protease, but negative in clumping factor and hemelysin on sheep blood agar. There was no difference related to origin in the production of extracellular active substances. Typical lesions of the classic exudative epidermitis were produced by inoculation of Staphylococcus hyicus subsp. hyicus isolated from the diseased and healthy pigs. The pathogenic potentials of isolates from healthy pigs were no different from that of the isolates obtained from diseased pigs.

• 상하수도학회지
• /
• 제33권6호
• /
• pp.429-436
• /
• 2019

Since the discovery of the first artificial synthetic plastic, bakelite, polymer materials have been recognized as one of the most innovative fields of research. The plastic debris that is being piled up on the earth (called abandoned plastic litters) is now being observed everywhere on Earth, becoming an increasingly serious environmental threat. The term 'microplastics', created in 2004, now refers to plastic particles that are smaller than 5 mm, including all nano-sized plastic particles. However, there is no legal regulation, and there is still a lack of comprehensive definitions that practically include microplastic size standards. In this study, we will refer to "microplastics" as the English name, and look at how to identify these microplastics and propose new definitions that focus on their size. This study is expected to contribute to the domestic consensus on scientific definitions of microplastics.

• 한국환경성돌연변이발암원학회:학술대회논문집
• /
• 한국환경성돌연변이발암원학회 2002년도 Current Trends in Toxicological Sciences
• /
• pp.48-64
• /
• 2002

The primary recognized health risk from common deficiencies in glucose-6-phosphate dehydrogenase (G6PD), a cytoprotective enzyme for oxidative stress, is red blood cell hemolysis. Here we show that litters from untreated pregnant mutant mice with a hereditary G6PD deficiency had increased prenatal (fetal resorptions) and postnatal death. When treated with the anticonvulsant drug phenytoin, a human teratogen that is commonly used in pregnant women and causes embryonic oxidative stress, G6PD-deficient dams had higher embryonic DNA oxidation and more fetal death and birth defects. The reported G6PD gene mutation was confirmed and used to genotype fetal resorptions, which were primarily G6PD deficient. This is the first evidence that G6PD is a developmentally critical cytoprotective enzyme for both endogenous and xenobiotic-initiated embryopathic oxidative stress and DNA damage. G6PD deficiencies accordingly may have a broader biological relevance as important determinants of infertility, in utero and postnatal death, and teratogenesis.-Nicol, C. J., Zielenski, J., Tsui, L.-C., Wells, P. G. An embryoprotective role for glucose-6-phosphate dehydrogenase in developmental oxidative stress and chemical teratogenesis.

• The Korean Journal of Ecology
• /
• 제26권4호
• /
• pp.203-208
• /
• 2003

Losses in the dry weight of leaf litter from six tree species were studied during 16 months on the forest floor in temperate deciduous forest of Mt. Cheonma in the vicinity of Seoul in Korea by using litter bag method. The decomposition rate of each leaf litter varies with each species. After 16 months elapsed, the leaf litter of Acer pseudo-sieboidianum showed the highest decomposition constant (0.82) as Olson´s decomposition constant, while that of Pinus densiflora showed the lowest decomposition constant (0.33). The decomposition constant of Quercus mongolica, Q. serrata, Betula ermani and Carpinus laxiflora showed 0.43, 0.37, 0.66 and 0.75, respectively. The decomposition constant of leaf litter was considered with temperature and precipitation which accumulated daily during each term of litter bag collection. The decomposition constant of leaf litter showed closely positive correlation with daily accumulative temperature and precipitation. The relationships between decomposition constant and the daily accumulative temperature and precipitation at each period of litter bag collection were analyzed through multi-regression analysis. The correlation coefficients as a result of multi-regression analysis in Q. mongolica, Q. serrata, P densiflora, B. ermani, C. laxiflorais and A. pseudo-sieboldianum were 0.83, 0.81, 0.69, 0.77, 0.77 and 0.62, respectively. The precipitation showed higher effect, about 10 times, on the leaf litter decomposition than the daily accumulative temperature.

• The Korean Journal of Physiology and Pharmacology
• /
• 제13권2호
• /
• pp.79-83
• /
• 2009

Exposure to early stressful adverse life events such as maternal and social separation plays an essential role in the development of the nervous system. Adolescent Sprague-Dawley rats that were separated on postnatal day 14 from their dam and litters (maternal social separation, MSS) showed hyperactivity and anxiolytic behavior in the open field test, elevated plus-maze test, and forced-swim test. Biologically, the number of astrocytes was significantly increased in the prefrontal cortex of MSS adolescent rats. The hyperactive and anxiolytic phenotype and biological alteration produced by this MSS protocol may provide a useful animal model for investigating the neurobiology of psychiatric disorders of childhood-onset diseases, such as attention deficient hyperactive disorder.

• The Korean Journal of Physiology and Pharmacology
• /
• 제23권1호
• /
• pp.81-87
• /
• 2019

Ketamine has long been used as an anesthetic agent. However, ketamine use is associated with numerous side effects, including flashbacks, amnesia, delirium, and aggressive or violent behavior. Ketamine has also been abused as a cocktail with ecstasy, cocaine, and methamphetamine. Several studies have investigated therapeutic applications of ketamine, demonstrating its antidepressant and anxiolytic effects in both humans and rodents. We recently reported that neonatal maternal separation causes enhanced anxiety- and aggressive-like behaviors in adolescent. In the present study, we evaluated how acute and chronic ketamine administration affected the behavioral consequences of neonatal maternal separation in adolescent mice. Litters were separated from dams for 4 hours per day for 19 days beginning after weaning. Upon reaching adolescence (post-natal day 35-49), mice were acutely (single injection) or chronically (7 daily injections) treated with a sub-anesthetic dose (15 mg/kg) of ketamine. At least 1 h after administration of ketamine, mice were subjected to open-field, elevated-plus maze, and resident-intruder tests. We found that acute ketamine treatment reduced locomotor activity. In contrast, chronic ketamine treatment decreased anxiety, as evidenced by increased time spent on open arms in the elevated-plus maze, and remarkably reduced the number and duration of attacks. In conclusion, the present study suggests that ketamine has potential for the treatment of anxiety and aggressive or violent behaviors.