• Parasites, Hosts and Diseases
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• v.45 no.2 s.142
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• pp.95-102
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• 2007

The mRNA expression of several cytokines was evaluated in splenocytes and mesenteric lymph node (MLN) cells of rats infected with Capillaria hepatica by reverse-transcription (RT)-PCR until week 12 after infection. IgG1 and IgG2a, which are associated with Th1 and Th2 response, respectively, were also assessed by ELISA. The results indicated that the majority of cytokines, including the Th1 (IL-2 and $IFN-{\gamma}$ and Th2 cytokines (IL-4, IL-5 and IL-10) were expressed at maximal levels during the early stage of infection (after week 1-2), and the ELISA data also evidenced a similar pattern of changes in IgG1 arid IgG2a. Th1 and Th2 cytokines responded in a similar fashion in this rat model. The expression of cytokines in splenocytes was significantly higher than that in MLN cells, thereby indicating that cytokine production is controlled more by spleen than by MLN. In addition, the observation that $IFN-{\gamma}$ expression increased unexpectedly at the time of maximal egg production (6 weeks after infection) indicated that $IFN-{\gamma}$ is a cytokine reacting against egg production. However, increased IL-5 expression occurring in tandem with worm activity indicated that the activity of C. hepatica might be controlled by IL-5 expression.

• Korean Journal of Poultry Science
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• v.44 no.4
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• pp.245-251
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• 2017

A dose-response experiment was conducted to determine the lysine requirement for broiler breeder hens during pre-peak production. Totally, one hundred and twenty-six flock 23-week-old Ross 308 broiler breeder hens with similar body weight were selected ($2,188{\pm}32g$) for a 6-week experiment. Hens were fed with a basal diet of corn-wheat-soybean meal formulated to achieve the Ross 308 breeder nutrient specifications (2016), except for lysine. The 7 graded, daily lysine intake levels used in this experiment were 732, 785, 838, 891, 944, 997, and 1,050 mg, and hens were restricted to 133 g of feed throughout this experiment. Pen based egg production were recorded once a day and all eggs were weighed daily. Age at sexual maturity was determined when the hens attained age at 25% production. Body weight at 23~29 weeks of age was not affected (P>0.05) by lysine levels. By fitting a linear-plateau model, the daily lysine requirements for feed conversion ratio, total produced egg weight, and age at sexual maturity at 23~29 weeks of age were estimated as 865, 907, and 891 mg, respectively. Using a quadratic-plateau model, the daily lysine requirement at 23~29 weeks of age were estimated as 974, 964, and 950 mg for feed conversion ratio, total produced egg weight, and age at sexual maturity, respectively. These results suggested that the daily lysine requirement for modern broiler breeder hens according to the National Research Council (1994) are insufficient for higher total produced egg weight, sexual maturity, and feed efficiency, and 120% of the NRC recommendation level would improve hen productivity when data are fitted under linear- and quadratic-plateau models.

• Journal of the Korean Home Economics Association
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• v.43 no.2
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• pp.19-31
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• 2005

The purpose of this study was to evaluate the microbiological quality and assure the hygienic safety of the Bibimbap production in elementary school foodservice in accordance with the HACCP(Hazzard Analysis Critical Control Point) program. The time-temperature relationship and the microbiological quality(total plate count and coliform bacteria count) were assessed to find the critical control point(CCP) during each of the production phase. In the pre-preparation phase, the risk factors of the raw ingredients exceeded the standard level suggested by Solberg et al. Mungbean starch jelly, egg and Kochujang were satisfactory in that no coliform groups were observed over the standard TPC level. In particular, there was a high the risk of beef from the early stages in terms of the coliform level. In the pre-preparation phase, green pumpkin had more coliform groups than the standard level even after washed, which calls for special attention to washing, sterilization, secondary infection of the handler, and the required time for pre-preparation of raw vegetables. In the cooking phase, the temperature of the soybean sprout and mungbean starch jelly decreased to 42$^{\circ}C$ and 26$^{\circ}C$, respectively, which was within the risk zone. In particular, mungbean starch jelly had a great risk factor even after boiling in hot water. During the storage stage before serving, a lot of ingredients were exposed to poor management of temperature and time and thus exceeded the standard level in the total plate counts. In particular, the microbiological count of beef was five times the standard level. Green pumpkins and soybean sprouts were left at 15-38$^{\circ}C$ that is within the risk zone for a long period of time after they were cooked. It is highly recommended that the time of the storage stage before consumption should be shortened and that proper devices should be used to prevent proliferation of bacteria. The number of TPC of the utensils was satisfactory enough, but the knife used exceeded the standard level and thus was a risk factor of bacteria proliferation.

• Korean Journal of Ichthyology
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• v.10 no.2
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• pp.184-190
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• 1998

The early life history of black bullhead, Pseudobagrus koreanus, endemic to Korea was investigated to get biological information needed in artificial production of seedlings and in recovering natural resources. The fertilized eggs showed some characteristics in having heavy sticky material and minute folds which is formed radical pattern on the egg membrane. The shape of egg was spherical and $2.59{\pm}0.08$(2.45~2.70, n=10)mm in diameter. The yolk had not oil globule. The first cleavage was observed 2 hrs after insemination at $21{\sim}23^{\circ}C$, and the progressive cleavage were done about 30 min. interval. The characteristic changing of the yolk surface started at morula stage and continued to the end of gastrula. Hatching was started 72 hrs and completed 90 hrs after fertilization. The size of the larvae were 5.41~5.81mm in total length and 2.76~2.94mm in preanal length, and the number of so mites was 15-16+33~34(48~50). The barbels and swimbladder were completed and all the fins except second dorsal were appeared 1 week after hatching. The larvae attained 9.67~10.52mm in total length and 5.20~5.65mm in preanal length. All the fin sets and color pattern were completed 2 weeks after hatching and body mucus was secreted at that stage. The juvenile attained 14.59~16.02mm in standard length, 3.31~4.16mm in head length and 8.07~9.31mm in prenal length.

• Journal of Aquaculture
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• v.10 no.1
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• pp.33-37
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• 1997

construct containing reporter gene(pFV4CAT) regulated by carp $\beta$-actin promoter was microinjected into the one-cell stage egg of mud loach (Misgurnus mizolepis), and was successfully expressed, possibly by the integration into the genome. Both mean hatching success and early survival of the microinjected groups were not significantly different with those of control groups (P>0.05). The incidence of transgene was ranged from 7 to 48% based on the PCR and/or Southern blot analyses with the DNA prepared from fin or blood tissue. The spatial and temporal patterns of expression of the pFV4CAT gene, measured by in situ immunohistochemical analysis peroxidase-conjugated anti-CAT antibody, were variable among the experimental individuals. These results suggest that carp $\beta$-actin promoter is effective to express other transgene in mud loach, such that this promoter can be useful in the generation of valuable transgenic mud loach.

• Korean journal of applied entomology
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• v.46 no.1 s.145
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• pp.141-145
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• 2007

Maggot therapy (MT) has been re-introduced for non-healing wounds such as pressure sore, diabetic and necrotic ulcers, as well as infected surgical wounds, burn, and trauma injuries since early 1990s. For the production of sterile maggot of proper developmental stage, Lucilia sericata were studied on developmental periods of immature stages on liver agar medium under six different temperatures such as 15.4, 20.6, 22.5, 26.2, 29.1, and $33.0^{\circ}C$, and adult longevity and egg Production under $29^{\circ}C$. The periods of eggs and larvae of the 1st and the 2nd instars were shortest at $33^{\circ}C$ by 9.0, 14.0 and 18.6 hours, respectively. The periods of the 3rd instar larvae and pupae were shortest at $29.1^{\circ}C$ by 285.0 and 171.0 hours, respectively. Developmental zero point and total effective temperature far the development of each stage were calculated based on the developmental periods. Adults of both female and male lived more than one month. Females laid an average of 338.5 eggs through 2.7 times of egg laying throughout her lifetime.

• Korean Journal of Animal Reproduction
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• v.5 no.1
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• pp.36-42
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• 1981

This experiment was carried out to determine the optimum interval between inseminations in artifical insemination of hens. Two hundred and forty hens of Hisex commercial stock at 25 weeks of age and 20 cocks of the Rhode Island Red at 40 weeks of age were used for the experiment, and a total of 6,784 eggs were obtained. The intervals between inseminations compared in this study were: 3 days (T1), 5 days (T2), and 7 days(T3). Mixed raw semen was inseminated and the semen does was 0.03ml per insemination per hen. The inseminations were conducted at 15:00 at each time. The total number of insemination performed was 9 for the T1, 6 for the T2 and 5 for the T3, and eggs were collected over a period of 31 days, 32 days and 35 dyas, respectively. The average egg production of the hens during the experiment was 85.9% and the average temperature during the experiment was around 30$^{\circ}C$. The average sperm count was 3.69 billion per ml. The results obtained in this experiment can be summarized as follows: The fertility over the entire experimental period bythe treatment was 91.7% for the T1, 84.4% for the T2, and 75.2% for the T3. The difference between T1 and T3 in fertility was significant at 5% level. The average fertility on the second, third and fourth day after the insemination in the T2 and T3 was maintained at a relatively high level, but it tended to decline rapidly from the fifth day after the insemination. The average fertility for one week after the last insemination was 88.8% for the T1, 88.8% for the T2 and 78.6% for the T3, and none of the differences among the treatments were statistically significant. On the basis of the results from this study, it is recommended to adjust the insemination intervals within the range from the 3 to 5 days in order to maintain a highest level of fertility in the hens at an early stage of egg production as in the case of the hens used in this experiment. An insemination interval of 3 days is recommended, especially at an initial stage of insemination. For the hens with a low fertility, shortening, of the insemination interval to 3 or 2 days is desirable.

• Parasites, Hosts and Diseases
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• v.23 no.1
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• pp.24-32
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• 1985

The worm development and egg laying pattern of Echinostoma hortense (Trematoda; Echinosto-matidae) were studied in albino rats and the brief clinical course was observed in human volunteers. A total of 21 rats were infected with 20~69 metacercariae each and two humans were with 7 and 27 metacercariae, which were collected from the loaches. For recovery of worms, the rats were sacrificed at irregular intervals from the 6th to 150th day after infection and the human volunteers were treated with praziquantel and purged with magnesium salt on the 26~27th day. The stools of the rats and humans were examined for the eggs. The results were as follows: 1. The worm recovery rate from the rats was not affected by the increase of infection time but varied individually; 9.1~50.0% (31.1 % in average). From humans, 14.3% and 37.0% (32.4% in average) of challenged were recovered. 2. In the rats, it was revealed that the worms rapidly grew for the first 14 days to become 7.59mm in average length and 1.17mm in average width but the growth became much slower thereafter until the 150th day; 7.95mm in length on the 21 th day, 9.04mm on the 28th day, 10.21mm on the 49th day and 12. 62mm on the 150th day. During the early stage of infection, the growth of genital organs (male or female) was expressed as sigmoid curves whereas non-genital organs (such as suckers) was simply as straight lines. 3. The prepatent period of this fluke was 10~12 days in the rats and 16~17 days in men. After the start of oviposition, the egg production by the worms remarkably increased, reached maximum on the 32~33th day, followed by decrease thereafter. The maximum value of E.P.G./worm was 390. 4. The major subjective symptoms in human volunteers were abdominal pain and diarrhea during the early stage of infection. The results show that human is as susceptible as the rats to E. hortense infection and the amount of egg production in the rats is greatly affected by the age of worms.

• Journal of Microbiology and Biotechnology
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• v.33 no.12
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• pp.1576-1586
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• 2023

Vaccination is the most effective method for preventing the spread of the influenza virus. Cell-based influenza vaccines have been developed to overcome the disadvantages of egg-based vaccines and their production efficiency has been previously discussed. In this study, we investigated whether treatment with forskolin (FSK), an adenylyl cyclase activator, affected the output of a cell-based influenza vaccine. We found that FSK increased the propagation of three influenza virus subtypes (A/H1N1/California/4/09, A/H3N2/Mississippi/1/85, and B/Shandong/7/97) in Madin-Darby canine kidney (MDCK) cells. Interestingly, FSK suppressed the growth of MDCK cells. This effect could be a result of protein kinase A (PKA)-Src axis activation, which downregulates extracellular signal-regulated kinase (ERK)1/2 activity and delays cell cycle progression from G1 to S. This delay in cell growth might benefit the binding and entry of the influenza virus in the early stages of viral replication. In contrast, FSK dramatically upregulated ERK1/2 activity via the cAMP-PKA-Raf-1 axis at a late stage of viral replication. Thus, increased ERK1/2 activity might contribute to increased viral ribonucleoprotein export and influenza virus propagation. The increase in viral titer induced by FSK could be explained by the action of cAMP in assisting the entry and binding of the influenza virus. Therefore, FSK addition to cell culture systems could help increase the production efficiency of cell-based vaccines against the influenza virus.

• Journal of Aquaculture
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• v.3 no.1
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• pp.79-88
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• 1990

In order to obtain the basic data fir the effective seed production of sea squirt, Halocynthia roretzi(Drasche), the influence of water temperature and light intensity on spawning induction, egg development and seed settling were investigated during the Period from December 24, 1906 to February 24, 1987. The maximum number of eggs spawned was obtained at $14^{\circ}C$. The relationships between the water temperature (T, $^{\circ}C$) and the required time (h, hour) in each egg developmental stage were given as follows : Up to 8 cell 1/h =0.0147 T-0.0069(.=0.9816), Up to 32 cell 1/h =0.0100 T-0.0017(r=0.9672), Up to early tadpole 1/h =0.0043 T+0.0024(r=0.9913), Up to hatching larva 1/h =0.0021 T-0.0021 (r=0.9898). The highest rate of seed attachment was obtained at $14^{\circ}C$ of water temperature.