• The Journal of Korean Society of Virology
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• v.26 no.1
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• pp.1-8
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• 1996

Human cytomegalovirus (HCMV) replication and $Ca^{2+}$ response in human cell lines of neuronal origin were investigated. SK-N-SH (neuroblastoma cells) and A172 cells (glioblastoma cells) were used. SK-N-SH cells were permissive for HCMV multiplication with a delay of one day compared to virus multiplication in human embryo lung (HEL) cells. The delay of HCMV multiplication in SK-N-SH cells appeared to be correlated with a delay in the $Ca^{2+}$ response. The cytoplasmic free $Ca^{2+}$ concentration ($[Ca^{2+}]_i$) began to increase at 12 h p.i. in HCMV-infected SK-N-SH cells, while $[Ca^{2+}]_i$ increase in HCMV-infected HEL cells was observed as early as 3 h p.i. On the whole, the level of the increase in $[Ca^{2+}]_i$ in SK-N-SH cells was about 30% of that in HEL cells. On the other hand, in A172 cells infected with HCMV, neither production of infectious virus nor detectable increase in $[Ca^{2+}]_i$ was observed. Treatment with TPA of HCMV-infected SK-N-SH cells resulted in $[Ca^{2+}]_i$ increase at 6 h p.i. The stimulatory effect of TPA on HCMV- induced $[Ca^{2+}]_i$ increase continued until 12 h p.i., but TPA failed to stimulate the $Ca^{2+}$ response in SK-N-SH cells at 24 h p.i., suggesting that the effect of TPA had disappeared in SK-N-SH cells at that time point. In conclusion, SK-N-SH cells are permissive for HCMV replication and the delay in $Ca^{2+}$ response may be a consequence of the lower responsiveness of SK-N-SH cells than HEL cells to HCMV infection.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.8
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• pp.1188-1192
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• 2003

Negative feedback on GH responses to GH-releasing hormone (GHRH) and GH-releasing peptides (GHRPs) has been reported and this action has been suggested to act through an increase in somatostatin. To determine whether the acute administration of porcine GH (pGH) inhibits GH responsiveness to GHRP-2 and GHRH in swine, swine were intravenously administered with pGH (5${\mu}g$/kg BW) or placebo followed 180 min later by a second intravenous administration of saline, GHRP-2 (30 ${\mu}g$/kg BW), GHRH (1${\mu}g$/kg BW) and a combination of GHRP-2 and GHRH. Plasma GH concentration was measured by radioimmunoassay. Administration of pGH caused a significant increase in GH area under curve and GH peak concentrations (p<0.001) over placebo-treated group. Plasma GH concentrations peaked at 15 min and returned to baseline level within 90 min. Pretreatment of pGH abolished (p<0.01) GH response to GHRH and attenuated (p<0.05) GH response to GHRP-2 and GHRH combined, without affecting GH response to GHRP-2. These results demonstrate that negative feedback action on GH releasing effect of GHRH occurs in swine, and that GHRP-2 has ability to interact in this action.

• Clean Technology
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• v.20 no.3
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• pp.226-231
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• 2014

This study presents a micromolding for the synthesis of Janus particles with reconfigurable shape by pH stimuli. First, we use acrylic acid (AA) as pH responsive monomer in the hydrophilic part and trimethylolpropane triacylate (TMPTA) in the hydrophobic part, respectively. The change of acidity in solvent induces the swelling of hydrophilic part in the Janus particles. The pH-responsive Janus particles show different swelling ratio of hydrophilic part in according to composition of acrylic acid in diverse range (0-70% v/v) and pH (3-11). As the concentration of acrylic acid in the hydrophilic part and environmental pH increase, the hydrophilic part in the Janus particles is proportionally swelled. Second, we fabricate novel type of Janus particles with two different hydrophilicities. As a proof of concept, we have applied acrylic acid (AA) and 2-(dimethylamino)ethyl methacrylate (DAEMA) into each part because the monomers provide reverse responsive activity. As expected, these Janus particles show different shape anisotropies with reconfigurable property in accordance with the polarity of each part at same acidity of environmental solvent. We envision that the stimuli responsive Janus particles have a wide application from fundamental science to diagnostic apparatus.

• Tuberculosis and Respiratory Diseases
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• v.85 no.1
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• pp.18-24
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• 2022

Background: Neutrophilic asthma (NeuA) is usually resistant to corticosteroids. Tiotropium bromide (TIO) is a bronchodilator that is used as an add-on therapy to inhaled corticosteroid and long-acting β2 agonist in asthma treatment. However, the role of TIO in NeuA is not fully known. Thus, the aim of this study was to evaluate the effect of TIO on NeuA compared to that of corticosteroids. Methods: C57BL/6 female mice were sensitized with ovalbumin and lipopolysaccharide to induce neutrophilic inflammation. Dexamethasone (DEX) was administered on days 14, 17, 20, and 23. TIO was inhaled on days 21, 21, and 23. On day 24, mice were sacrificed. Airway hyper-responsiveness, levels of cytokines in bronchoalveolar lavage (BAL) and lung homogenates, and lung tissue histopathology were compared between the two groups. Results: Neutrophil counts, T helper 2 cells (T_H2)/T_H17 cytokines, and pro-inflammatory cytokine in BAL fluids were elevated in the NeuA group. TIO group showed lower total cells, neutrophil counts, and eosinophil counts in BAL fluids than the DEX group (p<0.001, p<0.05, and p<0.001, respectively). Airway resistance was attenuated in the TIO group but elevated in the NeuA group (p<0.001). Total protein, interleukin (IL)-5, and IL-17A levels in BAL fluids were lower in the TIO group than in the NeuA group (all p<0.05). Conclusion: TIO showed more potent effects than DEX in improving airway inflammation and attenuating airway resistance in NeuA.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.2
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• pp.174-178
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• 2004

The objectives of this study were to investigate the ovarian responsiveness of juvenile calves to exogenous gonadotropin treatments and to establish the oocyte retrieval technique for prepubertal heifers. Three 78-day-old calves were treated with 4 doses (40, 30, 30 and 30 mg) of FSH (Folltropin V) at 12 h interval up to 229 day-old. Surgical oocyte retrieval was performed 24 h after the last injection of FSH. Calves with good ovarian responses to FSH treatment had an average ovarian size of $5{\times}3$ cm compared to $3{\times}2$ cm in the less-responsive animals. Large variations were observed in the number of total follicles ($51{\pm}45$), aspirated follicles ($39{\pm}36$), oocytes recovered ($23{\pm}25$) and usable oocytes recovered ($11{\pm}19$) during 78 to 229 day-old. Oocytes derived from prepubertal calves had significantly lower maturation rate than those from cows (34 vs. 100%, p<0.05). Mean diameters of calf oocytes ($144{\pm}1{\mu}m$) and ooplasm ($110{\pm}1 {\mu}m$) were significantly lower than those of cows ($149{\pm}1$ and $25{\pm}1{\mu}m$, respectively). The diameter of the ooplasm also increased significantly after in vitro maturation (IVM) ($108{\pm}1$ vs. $112{\pm}1{\mu}m$). However, further studies are required to optimize the IVP system for the oocytes derived from prepubertal heifers.

• Journal of Veterinary Science
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• v.25 no.2
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• pp.30.1-30.16
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• 2024

Background: Biofilms, such as those from Staphylococcus epidermidis, are generally insensitive to traditional antimicrobial agents, making it difficult to inhibit their formation. Although quercetin has excellent antibiofilm effects, its clinical applications are limited by the lack of sustained and targeted release at the site of S. epidermidis infection. Objectives: Polyethylene glycol-quercetin nanoparticles (PQ-NPs)-loaded gelatin-N,O-carboxymethyl chitosan (N,O-CMCS) composite nanogels were prepared and assessed for the on-demand release potential for reducing S. epidermidis biofilm formation. Methods: The formation mechanism, physicochemical characterization, and antibiofilm activity of PQ-nanogels against S. epidermidis were studied. Results: Physicochemical characterization confirmed that PQ-nanogels had been prepared by the electrostatic interactions between gelatin and N,O-CMCS with sodium tripolyphosphate. The PQ-nanogels exhibited obvious pH and gelatinase-responsive to achieve on-demand release in the micro-environment (pH 5.5 and gelatinase) of S. epidermidis. In addition, PQ-nanogels had excellent antibiofilm activity, and the potential antibiofilm mechanism may enhance its antibiofilm activity by reducing its relative biofilm formation, surface hydrophobicity, exopolysaccharides production, and eDNA production. Conclusions: This study will guide the development of the dual responsiveness (pH and gelatinase) of nanogels to achieve on-demand release for reducing S. epidermidis biofilm formation.

• Journal of Life Science
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• v.20 no.4
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• pp.496-502
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• 2010

The acidic saline animal model of pain has been suggested to mimic fibromyalgia (FM). Oligomeric proanthocyanidin complexes (OPC) from grape seeds are known to act as an antioxidant. We studied the effects of OPC on the pain threshold in the acidic saline animal model of pain. The left gastrocnemius muscle was injected with $100\;{\mu}l$ of saline at pH 4.0 under brief isoflurane anesthesia on days 0 and 5. Control rats (n=5) received identical injections of physiological saline (pH 7.2) on the same schedule. Rats (n=10) with acidic saline injection were separated into two study subgroups. After measurement of pre-drug pain thresholds, rats were injected intraperitoneally with either saline or OPC 300 mg/kg. Paw withdrawal thresholds to pressure were again measured 60 min after intraperitoneal injection. Nociceptive thresholds were measured with a Dynamic Plantar Aesthesiometer by applying an increasing pressure to right or left hind paw until the rat withdrew the paw. Compared to baseline (day 0), acid injections produced mechanical hyper-responsiveness on day 7 (pre-drug) in these rats [p<0.05]. A potent antihyperalgesic effect was observed when rats were injected intraperitoneally with OPC 300 mg/kg [injected paw, p=0.001; contralateral paw, p=0.002]. OPC treatment decreased the expression of acid sensing ion channel 3 in the brain motor cortex area on immunohistochemical staining when OPC 300 mg/kg was administered intraperitoneally in the animal model of FM pain [p<0.05]. Further research is required to determine the efficacy of OPC treatments in FM pain in humans.

• Biomedical Science Letters
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• v.9 no.4
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• pp.241-248
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• 2003

Sodium salicylate, a plant stress hormone that plays an important role(s) in defenses against pathogenic microbial and herbivore attack, has been shown to induce a variety of cell responses such as anti-inflammation, cell cycle arrest and apoptosis in animal cells. p38MAPK plays a critical role(s) in the cell regulation by sodium salicylate. However, the signal pathway for sodium salicylate-induced p38MAPK activation is yet unclear. In this study, we show that although sodium salicylate enhances reactive oxygen species (ROS) production, N-acetyl-L-cysteine, a general ROS scavenger, did not prevent sodium salicylate-induced p38MAPK, indicating ROS-independent activation of p38MAPK by sodium salicylate. Sodium salicylate-activated p38MAPK appeared to be very rapidly down-regulated 2 min after removal of sodium salicylate. Interestingly, sodium salicylate-pretreated cells remained fully responsive to re-induction of p38MAPK activity by a second sodium salicylate stimulation or by other stresses, $H_2O$$_2$ and methyl jasmonate (MeJA), thereby indicating that sodium salicylate does not exhibit both homologous and heterologous desensitization. In contrast, pre-exposure to MeJA, $H_2O$$_2$, heat shock, or hyperosmotic stress reduced the responsiveness to subsequent homologous stimulation. Sodium salicylate was able to activate p38MAPK in cells desensitized by other heterologous p38MAPK activators. These results indicate that there is a sensing mechanism highly specific to sodium salicylate for activation of p38MAPK, distinct trom pathways used by other stressors such as MeJA, $H_2O$$_2$ heat shock, and hyperosmotic stress.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.8
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• pp.1193-1198
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• 2003

An increase in frequency of administration of exogenous growth hormone (GH) or GH-releasing hormone was reported to be a model to increase blood circulating insulin-like growth factor-1 (IGF-1) and to improve growth performance in animals. We have investigated the effect of twice daily administration of GH-releasing peptide-2 (GHRP-2) on growth performance, GH responsiveness and plasma insulin-like growth factor IGF-1 in swine. We administered to eight swine, 3 control and 5 treatment, a twice daily s.c. injections of GHRP-2 ($30{\mu}g/kg\;BW$) for a period of 10 days. Every day blood samples immediately taken before injections of GHRP-2 or saline, at 08:00 h and 16:00 h, were measured for IGF-1 concentrations. Blood samples for GH assay were collected every 20 min on days 1, 6 and 10, from 1 hour before and 3 h after GHRP-2 or saline injections at 08:00 h. GH peak concentrations and GH area under curve (GH AUC) on day 1, 6 and 10 in treatment group of swine were higher than those in control swine (p<0.05). Twice daily administration of GHRP-2 caused a significantly attenuation (p<0.05) of GH peak concentrations ($80.25{\pm}13.87$, $39.73{\pm}5.72$ and $27.57{\pm}6.06ng/ml$ for day 1, 6 and 10, respectively) and GH AUCs ($3,536.15{\pm}738.35$, $1,310.31{\pm}203.55$ and $934.37{\pm}208.99ng/ml$ for day 1, 6 and 10, respectively). However, there was no significant difference in GH peak concentration and GH AUC between day 6 and 10. Plasma IGF-1 concentration levels were higher in treatment than control group of swine (p<0.05) after 3 days of the treatment, and the levels reached a plateau from day 3 to 10 of experiment. Growth performance did not alter by GHRP-2 administration, even though a numerical increase of body weight gain and feed efficiency was observed. These results indicate that twice daily administration of GHRP-2 for 10 days in swine did not significantly influence on growth performance, caused an overall attenuation of GH response, and that elevation of plasma GH concentrations caused by GHRP-2 administration increased plasma IGF-1 concentrations, even though an attenuation of GH response was observed.

• Clinical and Experimental Reproductive Medicine
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• v.32 no.1
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• pp.27-32
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• 2005

Objective: To evaluate the effectiveness of aromatase inhibitor (AI) for ovulation induction in polycystic ovary syndrome (PCOS) patients with thin endometrium, hyper-responsiveness after clomiphene citrate (CC) treatment. Material and Methods: A prospective study was performed in 43 PCOS patients (50 cycles) with ovulatory dysfunction between March 2004 and September 2004. AI group (total 36 cycles) included the patients 1) with thin endometrium below 6 mm on hCG day after CC (n=17), 2) with more than 5 ovulatory follicles after 50mg of CC (n=4), 3) who do not want multiple pregnancy (n=14). Patients were treated with Letrozole 2.5mg for days 3 to 7 of the menstrual cycle. CC group (total 14 cycles) were treated with CC 50~100 mg. Results: In PCOS patients, ovulation was occurred 97.2% after AI use. Between AI group and CC group, there was no significant difference in the mean age, duration of infertility, interval of menstruation, basal FSH, prior treatment cycles, and the day of hCG administration. But, the number of mature follicles (${\geq}15mm$) was lower in the AI group ($1.08{\pm}0.45$ vs. $1.64{\pm}0.75$) (p=0.018), and the thickness of endometrium (mm) was significantly thicker in the AI group ($10.35{\pm}1.74$ vs. $9.23{\pm}1.61$) (p=0.044), and E2 (pg/ml) concentration on hCG day was lower in the AI group ($116.9{\pm}75.8$ vs. $479.5{\pm}300.8$) (p=0.001). Among the AI group, patients with prior thin endometrium (below 6 mm) during CC treatment showed $10.6{\pm}1.6mm$ in the endometrial thickness and $106.6{\pm}66.8pg/ml$ in $E_2$ concentration. Patients with more than 5 ovulatory follicles after CC showed decreased follicle number ($1.25{\pm}0.5$) compared to prior CC cycle. Conclusions: In PCOS patients, AI group showed significantly thicker endometrium, lesser number of mature follicles, and lower E2 concentration on hCG day than CC group. AI might be useful alternative treatment for ovulation induction in PCOS patients with thin endometrium and hyper-responsiveness after CC treatment.