• Asian-Australasian Journal of Animal Sciences
• /
• v.4 no.1
• /
• pp.41-45
• /
• 1991

Insulin responsiveness to glucose and tissue responsiveness to insulin, using the hyperglycemic clamp and the hyperinsulinemic euglycemic clamp techniques, were compared among cows, sheep and pigs. The plasma insulin concentrations during the hyperglaycemic clamp period were highest (p < 0.05) in cows, followed by sheep and pigs. The glucose infusion rate in the hyperinsulinemic euglycemic clamp technique was greater (p < 0.01) in pigs than in cows and sheep. These results suggest responsiveness to insulin is higher in pigs than in cows and sheep.

• Asian-Australasian Journal of Animal Sciences
• /
• v.19 no.7
• /
• pp.1010-1018
• /
• 2006

A glucose clamp technique was used to investigate the effects of non-protein energy intake on tissue responsiveness and sensitivity to insulin for glucose metabolism in intact adults male goats. Three goats were fed diets at 1.0, 1.5 and 2.0 times of ME for maintenance, each for 21 d. Crude protein intake was 1.5 times of maintenance requirement in each treatment. Tissue responsiveness and sensitivity to insulin were evaluated using a hyperinsulinemic euglycemic clamp technique with four levels of insulin infusion, beginning at 13 h after feeding. Concentrations of plasma metabolites and insulin were also measured at 3, 6 and 13 h after feeding, for evaluating effects of non-protein energy intake on the metabolic status of the animals. Increasing non-protein energy intake prevented an increase in plasma NEFA concentration at 13 h after feeding (p = 0.03). Plasma urea-nitrogen and total amino-nitrogen concentrations decreased (p<0.01) and increased (p = 0.03), respectively, with increasing non-protein energy intake across time relating to feeding. Plasma insulin concentration was unaffected (p = 0.43) by non-protein energy intake regardless of time relating to feeding. In the glucose clamp experiment, increasing non-protein energy intake decreased numerically (p = 0.12) the plasma insulin concentration at half-maximal glucose infusion rate (insulin sensitivity), but did not affect (p = 0.60) maximal glucose infusion rate (tissue responsiveness to insulin). The present results suggest that an increase in non-protein energy intake may enhance insulin sensitivity for glucose metabolism, unlike responsiveness to insulin, in adult male goats. The possible enhancement in insulin sensitivity may play a role in establishing anabolic status in the body, when excess energy is supplied to the body.

• Asian-Australasian Journal of Animal Sciences
• /
• v.20 no.3
• /
• pp.385-392
• /
• 2007

A glucose clamp technique was used to compare dietary starch (ST), starch plus sucrose (ST+SU) and sucrose (SU) with regard to the effect on tissue responsiveness and sensitivity to insulin in intact adult male goats. The goats were fed diets containing 1.2 times of ME and CP for maintenance requirements twice daily for 21 d. Of the energy intake, 30% was offered with ST, ST+SU or SU for the respective diets, and 70% as alfalfa hay, ground corn and ground soybean meal at the respective weight ratio of 1, 1, and 0.3 for all diets. Tissue responsiveness and sensitivity to insulin were evaluated using a hyperinsulinemic euglycemic clamp technique with four levels of insulin infusion beyond 13 h after feeding. The concentrations of plasma metabolites and insulin were also determined at 3, 6 and 13 h after feeding to evaluate the effects of different carbohydrates on metabolic states in the body. Plasma glucose concentration was higher (p = 0.01) for SU diet than for ST and ST+SU diets. Increasing SU intake decreased (p<0.01) plasma acetate concentration across the time. At 3 h but not 6 and 13 h after feeding, high lactate (p = 0.01), and non-significant high propionate (p = 0.14) and low urea nitrogen (p = 0.19) concentrations were observed in plasma on SU compared with ST and ST+SU diets. Plasma insulin concentration was not different (p = 0.44) between ST and SU fed animals. In the glucose clamp experiment, considering the effects on the maximal glucose infusion rate (tissue responsiveness to insulin, p = 0.54) and the plasma insulin concentration at half-maximal glucose infusion rate (insulin sensitivity, p = 0.54), SU was not different from ST. It is concluded that SU may not be greatly different from ST with regard to the effect on tissue responsiveness and sensitivity to insulin in adult goats when fed twice daily as part of a high-concentrate diet. The possible greater effects of SU on plasma metabolites concentrations at 3 h than at 6 and 13 h after feeding suggest that a lack of persistency of SU effects during the postfeeding period may be associated with the poor response to SU in insulin action.

• International Journal of Advanced Culture Technology
• /
• v.11 no.4
• /
• pp.456-463
• /
• 2023

We conducted this study to identify the components of H&B store app service quality and their effect on customer satisfaction. The survey was conducted through an online survey for teenagers or older with experience in using H&B store app. A total of 330 copies were distributed and a total of 282 copies were used for the final analysis. The results of this study are summarized as follows: First, eight factors such as ease of use & design, fulfillment, playfulness, responsiveness, personalization, security, contextual usefulness, interactivity were derived as service quality components of H&B store app. Second, as a result of regression analysis, the six service quality components, such as 'ease of use & design', 'fulfillment', 'playfulness', 'responsiveness', 'security', and 'interactivity' were found to have a significant positive (+) effect on customer satisfaction (p<0.05) and 'playfulness (β=.372)' had the greatest effect on customer satisfaction. Based on the results of this study, we should strive to establish effective marketing strategies in the H&B industry.

• Polymer(Korea)
• /
• v.39 no.3
• /
• pp.359-364
• /
• 2015

A self-oscillating interpenetrating polymer network (IPN) poly(acrylic acid)/poly(ethylene glycol) (PAA/PEG) hydrogel was prepared by using radical polymerization with a two-step method. The IPN hydrogel was characterized by FTIR spectroscopy and morphological analysis. The results indicated that the chains of PEG and PAA twined to form porous structure which is beneficial to water molecules entering inside of the hydrogel. In addition, the pH-responsive behavior, salt sensitivity, swelling/de-swelling oscillatory behaviors and self-oscillation in a closed pH oscillator were also studied. The results showed that the prepared hydrogel exhibited pH-sensitivity, good swelling/de-swelling reversibility and excellent salt sensitivity. The self-oscillating behavior of swelling/de-swelling for the prepared hydrogel was caused by pH alteration coupled with the external media. This study may create a new possibility as biomaterial including new self-walking actuators and other related devices.

• Korean Journal of Animal Reproduction
• /
• v.22 no.1
• /
• pp.61-66
• /
• 1998

In vitro contractile response of the uterus in the pregnant rat to oxytocin increases with advancing gestation. This increase coincides with an increase in uterine oxytocin receptor number. However, in vitro the change in uterine contractile response of the pregnant uterus to oxytocin with advancing gestation is not clear. The purpose of the present study was to find out that the uterine response in vitro to oxytocin changes as delivery a, pp.oaches. Secondly, to determine if the incubation of uterine tissue in vitro altered the uterine oxytocin receptor number and affinity and thus explain the ambiguity between the in vitro and in vitro results. The studies were performed on rats at days 15, 20 and 21 or pregnancy. In vitro the uterine contractile response to oxytocin was sgreater (P<0.05) at day 21 compared to days 15 and 20 (Emax : 724.8　88.9, 130.0　81.5 and 133.4　53.4, respectively). This correlated with a significant increase (P<0.05) in uterine oxytocin receptor number at day 21 (days 21, 15 and 20 : 540　89, 53　24, 89　35 fmoles/mg protein, respectively). However, the kids at days 15, 20 and 21 did not differ (P>0.05). Finally no difference (P>0.05) in oxytocin receptor number or affinity was detected between incubated and non-incubated tissue. The results of these studies suggest that either pre-oxytocin or post-oxytocin receptor factors are important in determining the uterine myometrial responsiveness to oxytocin.

• Journal of Periodontal and Implant Science
• /
• v.47 no.2
• /
• pp.66-76
• /
• 2017

Purpose: Oral wound healing requires gingival fibroblasts to respond to local growth factors. Epigenetic silencing through DNA methylation can potentially decrease the responsiveness of gingival fibroblasts to local growth factors. In this study, our aim was to determine whether the inhibition of DNA methylation sensitized gingival fibroblasts to transforming growth factor-${\beta}1$ (TGF-${\beta}1$). Methods: Gingival fibroblasts were exposed to 5-aza-2'-deoxycytidine (5-aza), a clinically approved demethylating agent, before stimulation with TGF-${\beta}1$. Gene expression changes were evaluated using quantitative polymerase chain reaction (PCR) analysis. DNA methylation was detected by methylation-sensitive restriction enzymes and PCR amplification. Results: We found that 5-aza enhanced TGF-${\beta}1$-induced interleukin-11 (IL11) expression in gingival fibroblasts 2.37-fold (P=0.008). 5-aza had no significant effects on the expression of proteoglycan 4 (PRG4) and NADPH oxidase 4 (NOX4). Consistent with this, 5-aza caused demethylation of the IL11 gene commonly next to a guanosine (CpG) island in gingival fibroblasts. The TGF-${\beta}$ type I receptor kinase inhibitor SB431542 impeded the changes in IL11 expression, indicating that the effects of 5-aza require TGF-${\beta}$ signaling. 5-aza moderately increased the expression of TGF-${\beta}$ type II receptor (1.40-fold; P=0.009), possibly enhancing the responsiveness of fibroblasts to TGF-${\beta}1$. As part of the feedback response, 5-aza increased the expression of the DNA methyltransferases 1 (DNMT1) (P=0.005) and DNMT3B (P=0.002), which are enzymes responsible for gene methylation. Conclusions: These in vitro data suggest that the inhibition of DNA methylation by 5-aza supports TGF-${\beta}$-induced IL11 expression in gingival fibroblasts.

• Genomics & Informatics
• /
• v.6 no.1
• /
• pp.36-43
• /
• 2008

Radiotherapy would be the choice of treatment for human cancers, because of high cost-effectiveness. However, a certain population of patients shows a resistance to radiotherapy and recurrence. In an effort to increase the efficacy of radiotherapy, many efforts were driven to find the genes causing the unresponsiveness to ionizing radiation. In this paper, we compared the gene expression profiles of two lung cancer cell lines, H460 and H1299, which showed differential responses to ionizing radiations. Each cell were irradiated at 2 Gy, and harvested after 0, 2, 4, 8, 12 and 24 hours to examine the expressions. Two-way ANOVA analysis on time-series experiments of two cells could select 2863 genes differentially expressed upon ionizing radiation among 32,321 genes in microarray (p<0.05). We classified these genes into 21 clusters by SOM clustering according to the interaction between cell types and time. Two SOM clusters were enriched with apoptosis-related genes in pathway analysis. One cluster contained higher levels of phosphatidyl inositol 3-phosphate kinase (PI3K) subunits in H1299, radio-resistant cells than H460, radiosensitive cells. TRAIL receptors were expressed in H460 cells while the decoy receptor for TRAIL was expressed in H1299 cells. From these results, we could characterize the differential responsiveness to ionizing radiation according to their differential expressions of apoptosis-related genes, which might be the candidates to increase the power of radiotherapy.

• Prospectives of Industrial Chemistry
• /
• v.24 no.6
• /
• pp.32-40
• /
• 2021

세포 투과성 펩타이드(cell penetrating peptide; CPP)는 강력한 세포막 투과성을 보유하고 있어 난투과성 중거대분자 약물의 세포 내 전달체 개발에 있어 중요한 요소 기술로 부각되고 있다. 하지만 대부분의 세포 투과성 펩타이드는 타겟 세포에 대한 선택성 없이 투과하므로, 전신 투여시 심각한 부작용이 발생할 수 있다. 이 글에서는 선택적 세포 투과성 펩타이드를 개발하는 최근 연구 전략 중, 타겟 세포 표면에 존재하는 수용체에 결합하는 리간드를 이용한 전략과, 타겟 세포 주변의 물리, 화학, 생물학적 신호 변화를 이용하는 전략에 대해 소개한다. 특히, 최근 논문에 발표된, 어피버디(affibody)와 세포 투과성 펩타이드 결합체를 이용하여 HER2 수용체를 지닌 유방암 세포에 선택적 투과성을 부여하는 방법과, 암세포 주변의 작은 pH 변화를 감지하여 양전하성을 조절함으로써 수용체가 없는 유방암 세포에도 선택적으로 투과성을 보이는 방법에 대해 자세하게 소개한다.

• Macromolecular Research
• /
• v.17 no.12
• /
• pp.1025-1031
• /
• 2009

Several kinds of biodegradable hydrogels were prepared via in situ photopolymerization of Pluronic F127/poly($\varepsilon$-caprolactone) macromer and acrylic acid (AA) comonomer in aqueous medium. The swelling kinetics measurements showed that the resultant hydrogels exhibited both thermo- and pH-sensitive behaviors, and that this stimuli-responsiveness underwent a fast reversible process. With increasing pH of the local buffer solutions, the pH sensitivity of the hydrogels was increased, while the temperature sensitivity was decreased. In vitro hydrolytic degradation in the buffer solution (pH 7.4, $37^{\circ}C$), the degradation rate of the hydrogels was greatly improved due to the introduction of the AA comonomer. The in vitro release profiles of bovine serum albumin (BSA) in-situ embedded into the hydrogels were also investigated: the release mechanism of BSA based on the Peppas equation was followed Case II diffusion. Such biodegradable dual-sensitive hydrogel materials may have more advantages as a potentially interesting platform for smart drug delivery carriers and tissue engineering scaffolds.