• Journal of Korean Society on Water Environment
• /
• v.21 no.1
• /
• pp.7-13
• /
• 2005

With the appearance of pathogenic microorganisms, which were resistant to free chlorine, the significant attention to the necessity of powerful alternative disinfection methods such as ozone, chlorine dioxide, LTV irradiation to inactivating pathogens has been increased in water treatment. Among these alternative disinfection methods, ozone is well known as strong biocidal method and the usage of ozone is also increasing in Korea. However, in Korea, there has been no report on the quantitative study of Cryptosporidium parvum with ozone and its evaluation in advanced drinking water treatments. This study reports on the methodology for predicting the ozone inactivation of Cryptosporidium parvum by ozone disinfection in advanced drinking water treatment. The method is based on the fact that a specific inactivation level of microorganisms is achieved at a unique value of ozone exposures, independent of ozone dose and type of water, and quantitatively described by a delayed Chick-Watson model. The required values ${\bar{C}}T$ for 2 log inactivation of Cryptosporidium parvum was $6.0mg/L{\cdot}min$ and $15.5mg/L{\cdot}min$ at $20^{\circ}C$ and $5^{\circ}C$, respectively. From this obtained Cryptosporidium parvum inactivation curves and calculated ${\bar{C}}T$ values of advanced drinking water treatment water in Korea with FIA (Flow injection alaysis), we can predict that water treatment plant can achieve a 1.1~1.8 log inactivation and 0~0.4 log inactivation at $20^{\circ}C$ and $5^{\circ}C$, respectively. This methodology will be useful for drinking water treatment plants which intend to evaluate the disinfection efficiencies of their ozonation process without full scale test and direct experiments with Cryptosporidium parvum.

• Asian-Australasian Journal of Animal Sciences
• /
• v.17 no.11
• /
• pp.1586-1590
• /
• 2004

An experiment was carried out with day-old "Sonali" (♂RIR$\times$♀Fayoumi) chicks to investigate the efficacy of locally made low cost brooders for brooding chicks in rural areas. Three types of indigenous brooders viz. charcoal, haricane and sawdust brooders were used for brooding chicks throughout the experimental period of 28 days. The efficiency of the brooders was observed in respect of their ability to maintain temperature, fluctuation in temperature during operation and cost effectiveness. Following initial trial of temperature maintenance for 48 h, the chicks were put under the brooder stoves and brooded up to 28 days. The experimental birds were fed on chick starter diet. Maintenance of temperature with sawdust brooders was found satisfactory and optimum for brooding the chicks at different stages of brooding and at the same time involved least cost for brooding in comparison with charcoal and haricane brooders which did not perform well in generating heat necessary for brooding and were not economically feasible for poor farmers. On the other hand, performance of charcoal brooders was better in respect of temperature maintenance during initial stage (when the brooder was started) but the temperature fluctuated rapidly, whereas fluctuation of temperature was gradual in sawdust brooders. Body weight gain and feed conversion were best in sawdust brooders. Survivability was highest in sawdust brooders and lowest in haricane brooders. Sawdust brooders may be appropriate for brooding chicks in rural areas, where electricity is not available.

• Asian-Australasian Journal of Animal Sciences
• /
• v.19 no.2
• /
• pp.236-244
• /
• 2006

This study was designed to determine the effects of daidzein (DE) on hepatic lipid metabolism in chicks fed with low protein (LP) diet based on casein. In experiment 1, the male chicks were fed with one of the three levels of dietary protein containing 10.95%, 21.9% and 43.8% protein content for 2 days. In experiment 2, the chicks were fed one of the three levels of protein with or without DE at 1,000 mg/kg diet for 2 days. Experiment 3 was conducted to compare DE (LP+DE) with estradiol (LP+E2) in chicks fed with LP diet for 7 days. Plasma lipid profiles, hepatic lipid profiles, activities of hepatic malic enzyme and isocitrate dehydrogenase (ICDH) were measured. Transcriptions of hepatic fatty acid synthase, apolipoprotein-B (APO-B), and fructose bisphosphatase mRNA were measured by RT-PCR. Increasing dietary protein levels markedly decreased the concentrations of plasma triglycerides, hepatic total lipids, hepatic TG, and the mRNA transcriptions while the increased dietary protein levels increased hepatic ICDH activities in experiment 1. In experiment 2, the effects of dietary protein levels on blood and hepatic lipid content were more prominent than those of the additional DE. Interestingly, plasma TG levels were affected by DE supplementation (p<0.05). In experiment 3, DE inhibited APO-B mRNA expressions and stimulated the accumulation of lipid in the liver through mechanisms different from E2. In this study, we demonstrate that DE has beneficial effects on blood lipid profiles, but that it inhibits APO-B mRNA transcription and aggravates the fatty liver induced by LP diet in chicks.

• Korean Journal of Veterinary Research
• /
• v.14 no.1
• /
• pp.33-40
• /
• 1974

It has been generally understood that the intestinal tracts are under the control of the autonomic nerves; the parasympathetics are excitatory and the sympathetics inhibitory. However, it is recently reported that the actions of these autonomic nerves in the newborn animals are shown to be different from those in the adult animals in some species. In order to elucidate the role of sympathetic innervation to the intestinal tracts, the effects of periarterial nerve stimulation were studied in the periarterial sympathetics-jejunum preparations of the chick and the effects of some autonomic drugs on the isolated muscle strips were also studied. The results obtained were as follows: 1. The periarterial stimulation in the periarterial sympathetics-jejunum preparation elicited the responses of three patterns; 1) contrcation followed by relaxation 2) contraction only 3) relaxation only. The excitatory response was most effective in the stimulus frequencies of 40 cps, whereas the inhibitory response was maximal in the stimulus frequencies of 30 cycle per second. 2. The excitatory response to the periarterial stimulation was not affected by the pretreatment with phenoxybenzamine, dibenamine, propranolol and atropine, whereas the inhibitory response was completely blocked by the pretreatment with phenoxybenzamine and propranolol. 3. In the periarterial syrnpathetics-jejunum preparation treated with reserpine, the periarterial stimulation evoked only contraction, and the contraction was not affected by the pretreatment with phenoxybenzamine, propranolol and atropine. 4. The administration of norepinephrine evoked a relaxation in the isolated jejunum muscle strips and the effect was completely blocked by the pretreatment with phenoxybenzamine. 5. The administration of isoproterenol produced a relaxation in the isolated jejunum muscle strips and the effect was not affected by pretreatment with phenoxybenzamine, whereas the effect was completely blocked by the pretratment with propranolol. 6) The administration of acetylcholine produced a marked contraction in the isolated jejunum muscle strips and the effect was completely abolished by the pretreatment of atropine. These experimental evidences indicate that the inhibitory response to the periarterial stimulation is due to adrenergic fibers and the excitatory response is due to neither adrenergic nor cholinergic component.

• Korean Journal of Poultry Science
• /
• v.31 no.1
• /
• pp.37-44
• /
• 2004

It has been recognized that the hen, like its mammalian counterparts, provides young chicks with antibodies as protection against hostile invaders. This system facilitates the transfer of specific antibodies from serum to egg yolk, and provides a supply of antibodies called immunoglobulin Y(IgY) to the developing embryo and the hatched chick. The protection against pathogens that the relatively immune-incompetent newly hatched chick has, is through transmission of antibodies from the mother via the egg. Egg yolk, therefore, can be loaded with a large amount of IgY against pathogens which can immobilize the existing or invading pathogens during the embryo development or in day-old chicks. Thus, the immunization of laying hens to various pathogens results in production of different antigen-specific IgY in eggs. Egg yolk contains 8∼20 mg of jmmunoglobulins (IgY) per ml or 136∼340 mg per yolk suggesting that more than 30 g of IgY can be obtained from one immunized hen in a year. By immunizing laying hens with antigens and collecting IgY from egg yolk, low cost antibodies at less than $10 per g compared to more than $20,000 per g of mammalian IgG can be obtained. This IgY technology opens new potential market applications in medicine, public health, veterinary medicine and food safety. A broader use of IgY technology could be applied as biological or diagnostic tool, nutraceutical or functional food development, oral-supplementation for prophylaxis, and as pathogen-specific antimicrobial agents for infectious disease control. This paper has emphasized that when IgY-loaded chicken eggs are produced and consumed, the specific antibody binds, immobilizes and consequently reduces or inhibits the growth or colony forming abilities of microbial pathogens. This concept could serve as an alternative agent to replace the use of antibiotics, since today, more and more antibiotics are less effective in the treatment of infections, due to the emergence of drug-resistant bacteria.

• Korean Journal of Veterinary Research
• /
• v.34 no.1
• /
• pp.49-54
• /
• 1994

Teratogenic effects of diazinon were assessed on morphology of chick embryos cholinergic blocking agents. Diazinon at doses ranging from 25 to $2000{\mu}g/egg$, was injected on Day 3 of incubation. $TD_{50S}$, were different for the various teratogenic sings such as wry neck, micromelia, abnormal feathering, abnormal beak and curled claws. The threshold dose for wry neck was higher than the threshold dose for other signs; $40{\mu}g/egg$ produced substantial micromelia, abnormal feathering, abnormal beak and curled claws, but gave no sings of wry neck. In contrast to the teratogenic doses, the $LD_{50}$ of diazinon was very high(above $2000{\mu}g/egg$). One of the characteristics of diazinon-induced teratogenesis was reduction of body weight(78.8%) and body length(73.8%). Maximal teratogenic effects, scored as sings of retarded growth, wry neck, micromelia, abnormal feathering, abnormal beak, and curled claws, were produced when the insectcide was administered on the third or fourth day. The threshold dose for type II teratogenic sings including wry neck and short neck was higher than for type I including micromelia and abnormal feathering. Morphorlogical studies, using atropine and gallamine, suggested that nicotinc but not muscarinic receptors may be involved in the mechanism of diazinon-induced type II malformations.

• Journal of Animal Science and Technology
• /
• v.51 no.6
• /
• pp.485-492
• /
• 2009

Estrogen has dramatic effects on the development and function of the reproductive tract in mammals. Although diethylstilbestrol (DES) triggers the development of reproductive organs in immature animals, continued exposure to DES induces dysfunction of the female reproductive tract in mice. To investigate the effects of neonatal estrogen exposure on the reproductive tract of female chickens, we implanted DES pellets into the abdominal region of immature female chicks and then examined the effects of DES on the oviducts of both immature chicks and sexually mature chickens (30 weeks old). DES induced mass growth and differentiation of the oviduct in immature chicks. The chick oviduct increased by 2.7- and 29-fold in length and weight, respectively, following primary DES stimulation. In secondary DES stimulation, the length and weight of the chick oviduct increased by 4.5- and 74-fold, respectively. Additionally, DES treatments caused abnormal development of the infundibulum and magnum in hen oviducts. Furthermore, infundibulum abnormality gave rise to unusual ovulation of follicles and resulted in infertility and dysfunction of the magnum, such as less production of egg white proteins. Our results indicate that DES exposure during early developmental stages in chickens has detrimental effects on the development and maintenance of the female reproductive tract after sexual maturation.

• The Korean Journal of Zoology
• /
• v.31 no.2
• /
• pp.95-103
• /
• 1988

Alterations in the amount of fibronectin during chick myogenesis were investigated. The amount of fibronectin as measured by immunoblotting was found to decrease during the process. As a first step in answering the precise mode of change in the level of ibronedin during myogensis, the interaction of 28,000 dalton(28 kDa) amino terminal fragment of fibronectin as well as 85,000 dalton (85 kDa) fragrxient with myoblasts was examined. The specific binding of 125 l-28 kDa fragment to myoblasts was time-dependent and reached a maximum within 60 min. Unlabelled 28 kDa fragment inhibited the binding of 125 I-28 kDa fragment, whereas 85 kDa fragment containing adhesion promoting activity did not inhibit it. This finding suggests that the 28 kDa fragment interacts with the matrix assembly receptors but not with the cell adhesion receptors. Accordingly, the decrease in the level of fibronectin is likely to correlate with the fall of fibronectin receptors on the myoblasts.

• The Korean Journal of Zoology
• /
• v.37 no.3
• /
• pp.324-330
• /
• 1994

The multicatalvtic 205 proteasome consisting of 12-15 subunits of 22-35 kDa is the catalytic core of the ATP/ubiquitin-dependent 26S protease complex that also is comprised of multiple subunits of 22-110 KDa. In order to determine whether the proteolvtic activities change during muscle development, the enzyme preparations were obtained from 11-, 14- and 17-day old chick embryonic muscle using a BioGel A-1.5m column. The 26S complex preparation from 14- or 17-day old muscle hvdr olvz e d both N -s uccinvl- Le u- Le u -Val-Tvr-7- amido -4- methvlco umarin ( Suc- LLVY- AMC) and ubiquitin-Ivsozvme conjugates about 50% as well as that from 11-day old muscle. In addition, the activity of 20S proteBsome against Suc-LLVY-AMC also decreased by about 20-30%. However, the protein level of 265 complex remained constant during the entire development period, while that of 205 proteasome increased 5- to 6-fold, as analyzed by nondenaturins polyacrvlamide gel elenrophoresis followed by immunoblot analysis using the antibodies raised against the purified enzymes. Thus, the specific activity of 20S proteasome against the peptide must decrease rather dramatically during the muscle development. These results suggest that the development-dependent changes in the proteolytic activities of both 20S proteasome and 26S protease complect from embryonic muscle are due to alterations in the expression of certain subunits in the enzvmes that are responsible for their specific cataIVtic functions but not to overall changes in the enzyme amounts.

• The Korean Journal of Zoology
• /
• v.25 no.2
• /
• pp.55-62
• /
• 1982

DNA synthesis, unscheduled DNA synthesis, excision of pyrimidine dimers and phtoreactivation were determined in UV-irradiated differentiating muscle cells at various times of primary culture of 12 day chick embryos and results obtained were as follows. The rates of UV-induced unscheduled DNA synthesis were increased as increase of UV dose. And the rates were gradually decreased as the increase of time after culture, but at higher doses the decreasing tendency was remarkable. The patterns of DNA replication were changed drastically as a function of time so that in the seven day cultures the rate of $^3$H-thymidine incorporation was found to be 0.2% of the original activity. The pattern of inhibition of DNA replication by UV damage demonstrated that in cells of earlier stages there were no remarkable changes, but in cells of later stages there was significant fluctuation. Photoreactivation and the excision of pyrimidine dimer in the one day cultures showed that photoreactivation occurred immediately after UV-irradiation, but excision of pyrimidine dimer was gradually and slowly occurred. These results indicate that the differentiation of embryonic muscle cells accompanies the gradual reduction of DNA replication and unscheduled DNA synthesis, and that the photoreactivation is rapid process compared to excision repair.