This study was designed to investigate the effect of kinetin on in vitro development of parthenogenetic porcine oocytes exposed to demecolcine prior to activation. In vitro matured metaphase II stage oocytes were incubated in 0 or 2 g/ml demecolcine supplemented defined culture medium for 3 h and the oocytes were activated electrically. The parthenogenetic porcine embryos were then cultured in 0 or 200 M kinetin supplemented defined culture medium for 7 days. Regardless of demecolcine treatment, kinetin supplementation increased blastocyst rates significantly (7.0% versus 12.1% and 4.9% versus 8.5%; Control versus Kinetin and Demecolcine versus Kinetin + Demecolcine, respectively, p<0.05). Demecolcine treatment before activation tended to decrease blastocyst rates regardless of kinetin supplementation although it is not statistically significant. Total cell numbers in the blastocysts also tended to be elevated in embryos when supplemented with kinetin, however only the result between Kinetin and Demecolcine groups is statistically significant (37.6 7.2 versus 28.1 9.5, respectively, p<0.05). In conclusion, the present report shows that kinetin enhances developmental competence of parthenogenetic porcine embryo regardless of demecolcine pre-treatment before parthenogenetic activation when they were developed in defined culture condition.

본 연구에서는 poly(vinyl chloride) (PVC)가지형 공중합체 전해질과 헤테로폴리산(HPA)을 이용하여 유무기 합성 전해질막을 제조하였다. poly(vinyl chloride)-g-poly(styrene sulfonic acid) (PVC-g-PSSA)는 PVC의 이차 염소의 직접적인 개시를 이용한 atom transfer radical polymerization (ATRP)로 합성하였다. 이때, HPA 나노입자는 수소 결합을 통해 PVC-g-PSSA 가지형 공중합체와 결합하는 것을 FT-IR spectroscopy를 통하여 확인하였다. 전해질막의 수소이온 전도도는 HPA의 질량 분율이 0.3이 될 때까지 상온에서 0.049에서 0.068 S/cm로 증가하였다. 이것은 HPA 나노입자 고유의 전도도와 가지형 공중합체가 가지고 있는 술폰산의 강화된 산도 때문이라고 추정된다. 합습률은 HPA의 질량 분율이 0.45까지 증가할수록 130에서 84%로 감소하였다. 이것은 HPA나노입자와 고분자 메트릭스 사이의 수소 결합의 상호작용 때문에 물을 흡수하는 site의 수가 감소한 결과라고 볼 수 있다. 열중량 분석결과 HPA의 농도가 증가할수록 전해질막의 열적 안정성이 강화된다는 것을 알 수 있었다.

Successful in vitro embryo production heavily relies on the normal maturation and fertilisation of oocytes. We examined the normal and abnormal fertilisation of zebu cattle oocytes matured in vitro. Immature cumulus oocyte complexes (COCs) from zebu cattle ovaries at slaughter were matured in vitro (IVM) for 24 h. The oocytes were either fixed, stained and examined for nuclear changes or fertilised in vitro (IVF) with Percoll-separated, heparintreated spermatozoa (1.0 /mL) of zebu (n = 7) and crossbred bulls (n = 7). After 18 h of sperm-COCs co-incubation at C with 5% in humidified air, the presumptive zygotes were fixed, stained and examined for pronuclei. The number of oocytes retrieved per ovary was 5.4 0.7. The percentage of matured oocytes was 73.0. The difference in motility of spermatozoa before and after Percoll seperation was significant (p<0.001). The percentages of normal and abnormal fertilisation (polyspermia and oocytes with one pronucleus) varied significantly depending on individual bulls (p<0.05). A protocol for IVF of IVM oocytes in Bangladeshi zebu cattle is developed. A future study may elucidate the capacity of such IVM-IVF oocytes to develop to the blastocyst stage for transfer to surrogate mother.

Poly(vinyl chloride) (PVC) 주사슬과 poly(hydroxyethyl acrylate) (PHEA) 곁사슬로 구성된 빗살모양의 PVC-g-PHEA 공중합체를 원자전달라디칼 중합을 통해 합성하였다. 이렇게 합성된 PVC-g-PHEA의 OH 그룹과 이미다졸 디카르복실릭산 (IDA)의 COOH 그룹과의 에스테르 반응에 의하여 가교된 전해질막을 제조하였다. 인산(PA)을 도핑하여 이미다졸-인산 착체를 형성한 결과, PA함량이 증가함에 따라 고분자 전해질막의 수소 이온 전도도가 증가하였다. 특히 100도 비가습 조건에서 수소 이온 전도도는 최대 0.011 S/cm까지 증가하였다. 만능 재료 시험기(UTM) 측정결과, 제조된 PVC-g-PHEA/IDA/PA 전해질막은 575 MPa의 높은 Young 모듈러스 및 기계적 강도를 보여주었다. 열분석 결과(TGA) 전해질막은 200℃까지 열적으로 안정함을 확인하였다.

The present study was carried out to establish an animal model, displaying long-term learning and memory dysfunction, since single intracerebroventricular (icv) injection of amyloid β peptide (Aβ) causes a short-term memory impairment. Male ICR mice were fed a high-cholesterol diet (HCD) containing 3% cholesterol, 1% corn oil and 0.5% cholic acid, and 1 week later, icv injected with Aβ_1-42 (5 μg/head). Learning/ memory function was assessed via passive avoidance performances 1 day and 2, 4, and 6 weeks after Aβ_1-42 injection, in addition to blood biochemical analyses for lipid profiles and hepatic function. Total cholesterol, lowdensity lipoproteins and hepatic dysfunction parameters markedly increased, while high-density lipoproteins were reduced following HCD feeding. Whereas single injection of Aβ induced temporary memory loss 1 day after administration, exhibiting full recovery after 2 weeks, Aβ treatment in combination with HCD feeding lasted the learning/memory impairment up to 6 weeks. Therefore, it is suggested that hypercholesterolemia augments Aβ-induced memory loss, and that Aβ injection plus HCD feeding could be a long-term memorydeficit model suitable for long-term treatment with drugs or stem cells.

Cytosolic Ca2+ is an important regulator of tumor cell proliferation and metastasis. Recently, the strategy of blocking receptors and channels specific to certain cancer cell types has emerged as a potentially viable future treatment. Oral squamous cell carcinoma is an aggressive form of cancer with a high metastasis rate but the receptor-mechanisms involved in Ca2+ signaling in these tumors have not yet been elucidated. In our present study, we report that bradykinin induces Ca2+ signaling and its modulation in the human oral squamous carcinoma cell line, HSC-3. Bradykinin was found to increase the cytosolic Ca2+ levels in a concentration-dependent manner. This increase was inhibited by pretreatment with the phospholipase C-β inhibitor, U73122, and also by 2-aminoethoxydiphenyl borate, an inhibitor of the inositol 1,4,5-trisphosphate receptor. Pretreatment with extracellular ATP also inhibited the peak bradykinin-induced Ca2+ rise. In contrast, the ATP-induced rise in cytosolic Ca2+ was not affected by pretreatment with bradykinin. Pretreatment of the cells with either forskolin or phorbol 12-myristate 13-acetate (activators of adenylyl cyclase and protein kinase C, respectively) prior to bradykinin application accelerated the recovery of cytosolic Ca2+ to baseline levels. These data suggest that bradykinin receptors are functional in Ca2+ signaling in HSC-3 cells and may therefore represent a future target in treatment strategies for human oral squamous cell carcinoma.

A level of dietary iron may play a role in colon carcinogenesis. The effect of dietary iron on colon carcinogenesis was investigated in male ICR mice. Five-week old mice were acclimated for one week and fed on iron-normal diet (35 ppm Fe), iron-deficient diet (3 ppm), or iron-overloaded diet (350 ppm Fe) for 8 weeks. Animals received three (0-2^nd weeks after starting experiment) injections of azoxymethane (AOM; 10 mg/kg b.w.) to induce colonic aberrant crypt foci (ACF). There were five experimental groups including normal control without AOM, AOM+iron-normal diet (AOM+NFe), AOM+iron-deficient (AOM+LFe), AOM+ironoverloaded diet (AOM+HFe) groups. The total numbers of ACF and aberrant crypt (AC) were measured in the colonic mucosa after staining with methylene blue. The blood and serum were analyzed with a blood cell differential counter and an automatic serum analyzer. The hepatic iron levels were significantly dependent on the presence of iron in the diets. Iron-deficient diet significantly decreased the several hematological values. The values of glutamic oxaloacetic transaminase (GOT) and glutamic pyruvate transaminase (GPT) were also significantly decreased in iron-overloaded or iron-deficient diet groups, compared with normal iron diet group. Dietary iron-deficiency decreased the numbers of ACF (64.9) and AC (79.8) per colon by 20.6 and 21.8%, respectively, compared with AOM+NFe group (72.4 ACF/colon and 90.3 AC/colon). However, ironoverloaded diet increased ACF (82.9) and AC (96.0) induction by AOM, compared with normal iron diet. These results suggest that dietary iron can affect the colon carcinogenesis in the animal model of mice.

This study was carried out to investigate chemical ingredient of Cryptoporus vovatus . Methanol extract of Cryptoporus vovatus was analyzed by column chromatography, thin layer chromatography, HPLC, mass spectrophotometer. CVM33100Me21 was isolated by prep-HPLC from methylene chloride fraction. From the physico-chemical data, including NMR, MS, the chemical structure of the compound was determined to be an ergosterol peroxide. (Fig. 1)

This study was carried out to investigate chemical ingredient of Amillaria tabescens. Methanol extract of Amillaria tabescens was analyzed by column chromatography, thin layer chromatography, HPLC, mass spectrophotometer. ATB201 was isolated by prep-HPLC from butyl alcohol fraction. From the physico-chemical data, including NMR, MS, the chemical structure of the compound was determined to be an uracil. (Fig. 1). The molecular weights of uracil was 112.

Flavonoids are a large family of polyphenolic compounds synthesized by plants that have a common chemical structure. Flavonoids may be further divided into subclasses, Anthocyanidins, Flavan-3- ols, Flavanones, Flavonols, Flavones, Isoflavones. Flavonoids have antioxidant and antiradical activities. The antiradical efficacy of flavonoids have established structure-activity relationships (SAR) of the antioxidant activity. Reactivity of flavonoids is highly dependent on the configuration of OH groups on the flavonoid B and C rings, there being little contribution from A ring to antioxidant effectiveness. This short article presents the current knowledge on structural aspects on their free radical reactions of flavonoids.

We investigate the degeneracy in the pattern of central microlensing perturbations of a pair of planetary systems where the planets are located from the primary with projected separations in units of the Einstein radius s and s-1, respectively. From this, we confirm the fact that although alike, the patterns of central perturbations induced by a close (s < 1) planet and a wide (s > 1) planet are not identical and the degree of difference depends on the planet/primary mass ratio and the planet-primary separation. We find that the difference can be greater than 5% for planetary systems with lensing parameters located in the parameter space of (1/1.8 < lsl < 1.8, q > 5 x 10-3), (1/1.3 < lsl < 1/3, q > 1 x 10-3), and (1/1.2 < lsl < 1.2, q > 5 x 10-4), where q represents the planet/primary mass ratio. Although this range occupies a small fraction of the entire parameter space of planetary systems, we predict that the chance of resolving the close/wide degeneracy would not be meager considering that the planet detection efficiency is higher for planets with resonant separations (s ~ 1) and heavier masses. We also find that the differences between the perturbation patterns are basically caused by the effect of the planetary caustic. This explains the tendency of the perturbation difference where (1) the difference increases as the planet/primary mass ratio increases and the separation approaches the Einstein radius, (2) the region of major difference is confined within the region around the line connecting the central and the planetary caustics, and (3) a wide (close) planetary system has a more extended central perturbation region toward the (opposite) direction of the planet.

We propose a diagnostic that can resolve the planet/binary degeneracy of central perturbations in caustic-crossing high-magnification microlensing events. The diagnostic is based on the difference in the morphology of perturbation inside the central caustics induced by a planet and a wide-separation binary companion. We find that the contours of excess exhibit a concentric circular pattern around the caustic center for the binary-lensing case, while the contours are elongated or off-centered for the planetary case. This difference results in the distinctive features of the individual lens populations in the residual of the trough region between the two peaks of the caustic crossings, where the shape of the residual is symmetric for binary lensing while it tends to be asymmetric for planetary lensing. We determine the ranges of the planetary parameters for which the proposed diagnostic can be used. The diagnostic is complementary to previously proposed diagnostics in the sense that it is applicable to caustic-crossing events with small finite-source effect.

The spatial and temporal distributions of phosphorus and nitrogen and a number of physical, chemical and biological parameters were analyzed to in the Youngsan and the Sumjin River systems, Korea. Substantial amount of P and N was observed in both the rivers all the year round. Mean N/P ratios showed large variations among the sampling sites; highest ratio was observed in most sampling sites during summer. Relative proportions of DOP: TP were fairly constant (0.08~0.09) in both the rivers. In the composition of nitrogen almost all sampling sites of both the rivers were dominated with NO3-N followed by NH3-N and NO2-N. Variations in dissolved nutrients tended to co-vary with particulate forms (PON and POP), implying that dissolved nutrients are primarily released from the decomposition of particulate forms or dissolved forms are in equilibrium with particulate forms. Chlorophyll a levels in the Sumjin River appear to be negatively correlated with the ammonia, implying ammonia is absorbed by algae with preference. While chlorophyll a was positively correlated with TP and DIP in the Sumjin River, negative correlations of these parameters was observed in the Youngsan River. The pattern of nutrients level was found to be related with land use and domestic sewage in the study area. Inter-parameter relationships may be strongly influenced by geographical factors relative to temporal factors.

This paper presents a case of the implementation of international distance courses between two universities of Taiwan and Japan in Asia-Pacific area. It reports the design of activities engaged in learning with supports of various communication tools. It also examines the students’ interaction and context of learning in distance education. The paper begins by briefly introducing the initiatives, the curriculum and the instructional design on implementation of the case. It then presents results of the study with discussion, along with assessment data available on its success. Meanwhile, it also explores cultural interaction among students and class dynamics observed throughout this study. Finally, this paper closes by making recommendations for further research possibilities and practical applications aiming at enhancing international distance education.