• Korean Journal of Veterinary Research
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• v.36 no.2
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• pp.305-312
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• 1996

Cell volume regulatory mechanisms are usually disclosed by exposure of cell to anisotonic media. If a cell is suddenly exposed to hypotonic media, it swells initially like an osmometer but within minutes regains its original cell volume. This behavior has been labelled as regulatory cell volume decrease(RVD). RVD is believed to result from the loss of permeable ions through the membrane. In this study, we examined hypotonically induced changes in the membrance currents involved in RVD by using whole cell voltage clamp technique in the unfertilized hamster egg. At -40mV of the holding potential, the stationary current was maintained in the hamster egg exposed to isotonic solution composed of, mainly, 115mM NaCl and 40mM mannitol. Hypotonic solution was prepared by removing mannitol. Therefore, the concentrations of $Na^+$ and $Cl^-$ in this hypotonic media were the same as those in the isotonic solution. Following 30 to 60 sec after applying the hypotonic media to the egg, the inward current was evoked. This inward current was eliminated by $100{\mu}M$ 4-acetamido-4'-isothiocyanostil-bene-2,2'-disulfonic acid(SITS), an anion channel blocker, leaving the small outward current component. Further addition of 2mM $Ba^{2+}$, a broad $K^+$ channel blocker, completely abolished the small outward current left even in the presence of SITS during hypotonic stress. These results suggest that $K^+$ and $Cl^-$ move out of cells, resulting in RVD. To test the involvement of $Na^+$ in RVD, 20mM Na-isethionate was substituted for mannitol in isotonic media(135mM $Na^+$) and Na-isethionate (20mM) was freed the hypotonic solution. Only $Cl^-$ concentration in both isotonic and hypotonic media was kept constant at 115mM, whereas concentration of $Na^+$ was lowered in hypotonic solution to 115mM from 135mM in isotonic solution. Hypotonic medium induced the outward current in the egg equilibrated isotonically. This current was reduced by $100{\mu}M$ SITS but was augmented by 2 mM $Ba^{2+}$. In terms of RVD, these results imply that $Cl^-$ efflux is coupled with $K^+$, maybe for electroneutrality during hypotonic stress and/or with $Na^+$ via unknown transport mechanism(s). From the overall results, the hypotonic stress facilitates the movement of $Cl^-$ and $K^+$ out of the hamster egg to regain cellular volume with electroneutrality. If there exist a difference in $[Na^+]_0$ between isotonic and hypotonic solution, another transport mechanism concerned with $Na^+$ may, at least partly, participate in regulatory volume decrease.

• Korean Journal of Ecology and Environment
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• v.39 no.3 s.117
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• pp.378-389
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• 2006

Seasonal changes of biomass and cell size of bacteria and protozoa, and factors affecting their distribution in Lake Paldang and Kyungan Stream were analyzed from April to December, 2005. Bacterial abundance at Paldang Dam and Kyungan Stream was similar, but it did not much increase during hot summer period. Protozoan carbon biomass was much greater at Kyungan Stream compared to Paldang Dam. HNAN generally accounted for the majority of total protozoan biomass, but ciliates made up the highest proportion in April and November at Paldang Dam and June at both sites. PNAN showed low biomass at both sites, but it was high during spring and fall season. Small-sized HNAN ($3{\sim}7\;{\mu}m$) numerically predominated the protozoan community at both sites. Average cell size of HNAN was bigger at Kyungan Stream where nutrients concentration was much higher than Paldang Dam. Average cell size of ciliates varied seasonally; it was relatively small during the summer. HNAN biomass significantly correlated with Chl-a concentration and ciliates biomass at Paldang Dam, indicating that HNAN increase might link to the ciliates increase. At Kyungan Stream, HNAN biomass showed a significant relationship with PNAN biomass, and Chl-a concentration was closely related with both of HNAN and PNAN biomass. Ciliate biomass showed significant relationship with nutrient (TN, TP) and particulate matter (SS) only at Kyungan Stream. At both sites, protozoan biomass was significantly correlated with bacterial biomass, and ciliates were additionally related flagellates. High biomass of microbial components and the close relationships among them suggest that the energy transfer through the microbial loop may important in the plankton food web of Lake Paldang ecosystem.

• Progress in Medical Physics
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• v.2 no.2
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• pp.109-120
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• 1991

Total body irradiation is operated to irradicate malignant cells of bone marrow of patients to be treated with bone marrow transplantation. Field size of a linear accelerator or cobalt teletherapy unit with normal geometry for routine technique is too small to cover whole body of a patient. So, any special method to cover patient whole body must be developed. Because such environments as room conditions and machine design are not universal, some characteristic method of TBI for each hospital could be developed. At Seoul National University Hospital, at present, only a cobalt unit is available for TBI because source head of the unit could be tilted. When the head is tilted outward by 90$^{\circ}$, beam direction is horizontal and perpendicular to opposite wall. Then, the distance from cobalt source to the wall was 319 cm. Provided that the distance from the wall to midsagittal plane of a patient is 40cm, nominal field size at the plane(SCD 279cm) is 122cm$\times$122cm but field size by measurement of exposure profile was 130cm$\times$129cm and vertical profile was not symmetric. That field size is large enough to cover total body of a patient when he rests on a couch in a squatting posture. Assuming that average lateral width of patients is 30cm, percent depth dose for SSD 264cm and nominal field size 115.5cm$\times$115.5cm was measured with a plane-parallel chamber in a polystyrene phantom and was linear over depth range 10～20cm. An anthropomorphic phantom of size 25cm wide and 30cm deep. Depth of dose maximum, surface dose and depth of 50% dose were 0.3cm, 82% and 16.9cm, respectively. A dose profile on beam axis for two opposing beams was uniform within 10% for mid-depth dose. Tissue phantom ratio with reference depth 15cm for maximum field size at SCD 279cm was measured in a small polystyrene phantom and was linear over depth range 10～20cm. An anthropomorphic phantom with TLD chips inserted in holes on the largest coronal plane was bilaterally irradiated by 15 minute in each direction by cobalt beam aixs in line with the cross line of the coronal plane and contact surface of sections No. 27 and 28. When doses were normalized with dose at mid-depth on beam axis, doses in head/neck, abdomen and lower lung region were close to reference dose within $\pm$ 10% but doses in upper lung, shoulder and pelvis region were lower than 10% from reference dose. Particulaly, doses in shoulder region were lower than 30%. On this result, the conclusion such that under a geometric condition for TBI with cobalt beam as SNUH radiotherapy departement, compensators for head/neck and lung shielding are not required but boost irradiation to shoulder is required could be induced.

• Journal of Sericultural and Entomological Science
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• v.16 no.2
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• pp.119-125
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• 1974

When the nomal silkworms reached active time of 3rd instar stage both non-moulting larva and normal silkworms from the same rearing tray were collected and fixed. The silkworms in 4th instar stage whose growth was as dwarfish as those in 1st and 2nd instar stages were also collected and fix with the normal silkworms. Non-moulting larva and normal silkworms were morphologically compared and the examined results from the tissue inspection are summarized as follows： 1. In spite of the fact that the normal silkworms reached the active eating time of 3rd instar stage non-moulting silkworms were dwarfish as if they had been reared for two days. Non-moulting silkworms which were observed at the time of 4th instar stage showed no much difference in their growth. 2. There was the tendency that the exuvial gland as was shown in Fig. 1 and 2 was flat cyslidium of ellipse and its size at thorax was small shile the gland at abdomen was big. 3. The exuvial gland at thorax has been reported to be bigger at thoracic base than at dorsal vessel but according to the present it was examined to be irregular. 4. The size of exuvial gland of silkworms in the active eating stage of 3rd instar was from 151.3${\mu}$ (major axis) to 94.5${\mu}$ (minor axis) at prothorax and from 568.6${\mu}$ (major axis) to 495.1${\mu}$ (minor axis) at 7th abdominal segment. The sire oe exuvial gland of non-moulting silkworm was 57.5${\mu}$ (major axis) to 51.3${\mu}$ (minor axis) at prothorax and from 91.5${\mu}$ (major axis) to 75.5${\mu}$ (minor axis) at 5th abdominal segment (see Fig. 1) 5. When the normal silkworms reached 4th instar active eating stage its exuvial gland was compared to that of dwarfish silkworm. The result was that the size of normal silkworm at prothorax was from 252.2${\mu}$ (major axis) to 131.6${\mu}$ (minor axis) and the size of exuvial gland at 7th abdominal segment was from 691.5${\mu}$ (major axis) to 493.4${\mu}$ (minor axis) while the sire of exuvial gland of non-moulting at prothorax was from 71.4${\mu}$ (major axis) to 61.5${\mu}$ (minor axis) and the size of the non-moulting silkworm's 8th abdominal segment was from 94.6${\mu}$ (major axis) to 71.5${\mu}$ (minor axis) (See Table 2) 6. There was a remarkable difference in the from of exuvial gland of non-moulting silkworm. The size of alveolar of the non-moulting silkworm was many times larger compared to that of normal silkworm 7. There was no great difference between secretory cells of normal and non-moulting silkworms but the granular type exuvial gland was small in sire compared to that of normal silkworm.

• Tuberculosis and Respiratory Diseases
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• v.46 no.2
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• pp.195-203
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• 1999

Background: Telomerase enzyme activity is not detected in most normal cells, a phonomenon believed to be associated with limitations on cellular proliferation. Since this activity is detected in nearly all human tumor, including lung cancers, it has been suggested that telomerase activation may be coupled to acquisition of malignant phenotype. In this study, we determined whether telomerase activity was associated with tumor pathologic stage. Methods: Primary tumor specimens obtained by bronchoscopic biopsies from 33 patients were analyzed. Telomerase activity was measured by means of a modified Telomeric Repeat Amplication Protocol(TRAP) assay. Results: Telomerase activity was detected in 23 of the 27 non-small-cell lung cancer and 5 of 6 small-cell lung cancer. A few primary tumors did not appear to have detectable telomerase activity. Positive associations were found between the telomerase-positive rate and tumor stage(p<0.05). Conclusion: High telomerase activity is detected frequently in primary lung cancers that exhibit high tumor cell proliferation rates and advanced pathologic stage.

• Radiation Oncology Journal
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• v.22 no.1
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• pp.1-10
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• 2004

Locally advanced (Stage III) non-small cell lung cancer (NSCLC) accounts for approximately one third of all cases of NSCLC. Few patients with locally advanced NSCLC present with disease amenable to curative surgical resection. Historically, these patients were treated with primary thoracic radiation therapy (RT) and had poor long term survival rates, due to both progression of local disease and development on distant metastases. Over the last two decades, the use of multidisciplinary approach has improved the outcome for patients with locally advanced NSCLC. Combined chemoradiotherapy is the most favored approach for treatment of locally advanced unresectable NSCLC. There are two basic treatment protocols for administering combined chemotherapy and radiation, sequential versus concurrent. The rationale for using chemotherapy is to eliminate subclinical metastatic disease while improving local control. Sequential use of chemotherapy followed by radiotherapy has improved median and long term survival compared to radiation therapy alone. This approach appears to decrease the risk of distant metastases,, but local failure rates remain the same as radiation alone. Concurrent chemoradiotherapy has been studied extensively. The potential advantages of this approach may include sensitization of tumor cells to radiation by the administration of chemotherapy, and reduced overall treatment time compared to sequential therapy; which is known to be important for improving local control in radiation biology. This approach Improves survival primarily as a result of improved local control. However, it doesn't seem to decrease the risk of distant metastases probably because concurrent chemoradiation requires dose reductions in chemotherapy due to increased risks of acute morbidity such as acute esophageal toxicity. Although multidisciplinary therapy has led to improved survival rates compared to radiation therapy alone and has become the new standard of care, the optimal therapy of locally advanced NSCLC continues to evolve. The current issues in the multidisciplinary management of locally advanced NSCLC will be reviewed in this report.

• Korean Journal of Environment and Ecology
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• v.23 no.5
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• pp.431-438
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• 2009

The main purpose of this research is to prepare and provide basic materials for the propagational strategy of eelgrass by investigating on the morphological adaptation of Korean Zostera marina to ocean currents. An eelgrass plant mainly consists of rhizome, leaf sheath, leaves and roots. The rhizome is the horizontal stem of the plant that serves as the backbone from which the leaves and roots emerge. The leaf sheath is the bundle at the base of the leaves that holds the leaves together, protecting the meristem, the primary growth point of the shoot. Leaves originate from a meristem which is protected by a sheath at the actively growing end of the rhizome. As the shoot grows, the rhizome elongates, moving across or within the sediment, forming roots as it progresses. The aggregated leaves from the leaf sheath are found to have two cell layers on one side and multiple layers of airy tissues called aerenchyma on the other. The aerenchyma tissues are developed in multi-layered cell structures surrounding the veins which are formed in the leaf sheath. Generative shoots are made of rhizomes, which are circular or ovoidal, stem, and spathe and spadix. The transverse section of rhizome and the stem and central floral axis is found to be circular, ovoid and in the shape of convex respectively, and the vascular bundle, which is a part of transport system, has one large tube in the center and two small tubes on both sides. The layers of collenchyma cells numbered from 12 to 15 in the stem, and from 7 to 12 in the rhizome. The seed coat is composed of sclereids, small bundles of sclerenchyma tissues, which prevent the influx of sea water from the outside and help endure the environmental stress. In conclusion, alternative multi-layer structure in circular, convex type aggregated leaf base are interpreted to morphological adaption as doing tolerable elastic structure through movement of seawater. The generative shoots develop long slim stem and branches in circular or ovoidal shapes to minimize the adverse impacts of sea current, which can be interpreted as the plant's morphological adaptation to its environment.

• Tuberculosis and Respiratory Diseases
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• v.52 no.2
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• pp.117-127
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• 2002

Backgroud : MUC1 mucin is a heavily glycosylated large glycoprotein and is expressed aberrantly in carcinoma. CD44 is polymorphic family of cell surface glycoproteins participating in cell-cell adhesion and modulation of the cell-matrix interaction. MUC1 mucin and CD44 expression have been implicated in a tumor invasion and metastasis in certain malignancies. In this study, the expression of MUC1 and the standard form of CD44 (CD44s) was examined in non-small cell lung cancer (NSCLC). Methods : Immunohistochemical staining using monoclonal antibodies including MUC1 glycoprotein and CD44s was performed on 80 NSCLC surgical specimens. The association between MUC1 and CD44s expression and the histological type and tumor stage was investigated. Results : Depolarized MUC1 expression in more than 10% of cancer cells was found in 12 (27.9%) out of 43 squamous cell carcinomas (SCCs) and 12 (32.4%) out of 37 adenocarcinomas (ACs). It was not associated with the tumor histological type and the TNM-stage in SCCs. Depolarized MUC1 expression correlated with the N-stage in ACs (p=0.036). CD44s was expressed in 36 (83.7%) out of 43 SCCs and 14 (37.8%) out of 37 ACs. Reduced CD44s expression correlated with the N-stage (p=0.031) and the TNM-stage (p=0.006) in SCCs. Conclusions : Depolarized MUC1 expression was related to the nodal stage in NSCLC adenocarcinoma. Reduced CD44s expression was related to nodal involvement and the TNM-stage in squamous cell carcinoma. This suggests that MUC1 and CD44s expression in NSCLC might play important roles in tumor progression and cap be used as prognostic variables.

• Korean Journal of Microbiology
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• v.50 no.4
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• pp.296-301
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• 2014

Rotavirus is a major cause of acute gastroenteritis in young children in developed and developing countries. The use of probiotics for the treatment of gastrointestinal diseases is both safe and easily accessible. In this study, we evaluated the anti-rotaviral activities of probiotic mixtures in a Sprague-Dawley rat. 24 litters with their dams were randomly assigned to four groups; placebo, phosphate buffered saline (PBS), and two probiotic mixture (PRO-1 and PRO-2) groups. All rats were inoculated with rotavirus at dose of 8 log plaque forming units per rat at 5 days old. Animals in the PRO-1 and PRO-2 groups were orally administered probiotic mixtures 1 or 2, respectively, at a dose of 8 log colony forming units daily during 4 days. For control purposes, placebo and PBS groups were orally administered the same amount of placebo (containing maltose and polydextrose) or PBS once daily for 4 days, respectively. Antiviral analysis was performed by real-time quantitative PCR (RT-qPCR) and observing intestinal villi. As a result, weights of small intestines were greater in the PRO-1, PRO-2 groups than in control groups. Villi were short and villous epithelial necrosis was exhibited in control groups, but these morphological changes were not observed in PRO-1, PRO-2 treated rats. RT-qPCR analysis showed that VP7 gene level of rotavirus in fecal samples and small intestinal epithelial cells were lower in the PRO-1 and PRO-2 groups. These findings suggest that probiotic mixtures may be useful probiotics for the treatment of or as alternative therapies for rotaviral gastroenteritis.

• Tuberculosis and Respiratory Diseases
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• v.56 no.5
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• pp.465-484
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• 2004

Background : Insulin-like growth factor (IGF)-binding protein-3 (IGFBP-3) inhibits the proliferation of non-small cell lung cancer (NSCLC) cells by inducing apoptosis. Methods : In this study, we investigated whether hypermethylation of IGFBP-3 promoter play an important role in the loss of IGFBP-3 expression in NSCLC. We also studied the mechanisms that mediate the silencing of IGFBP-3 expression in the cell lines which have hypermethylated IGFBP-3 promoter. Results : The IGFBP-3 promoter has hypermethylation in 7 of 15 (46.7%) NSCLC cell lines and 16 (69.7%) of 23, 7 (77.8%) of 9, 4 (80%) of 5, 4 (66.7 %) of 6, and 6 (100%) of 6 tumor specimens from patients with stage I, II, IIIA, IIIB, and IV NSCLC, respectively. The methylation status correlated with the level of protein and mRNA in NSCLC cell lines. Expression of IGFBP-3 was restored by the demethylating agent 5'-aza-2'-deoxycytidine (5'-aza-dC) in a subset of NSCLC cell lines. The Sp-1/ Sp-3 binding element in the IGFBP-3 promoter, important for promoter activity, was methylated in the NSCLC cell lines which have reduced IGFBP-3 expression and the methylation of this element suppressed the binding of the Sp-1 transcription factor. A ChIP assay showed that the methylation status of the IGFBP-3 promoter influenced the binding of Sp-1, methyl-CpG binding protein-2 (MeCP2), and histone deacetylase (HDAC) to Sp-1/Sp-3 binding element, which were reversed by by 5'-aza-dC. In vitro methylation of the IGFBP-3 promoter containing the Sp-1/Sp-3 binding element significantly reduced promoter activity, which was further suppressed by the overexpression of MeCP2. This reduction in activity was rescued by 5'-aza-dC. Conclusion : These findings indicate that hypermethylation of the IGFBP-3 promoter is one mechanism by which IGFBP-3 expression is silenced and MeCP2, with recruitment of HDAC, may play a role in silencing of IGFBP-3 expression. The frequency of this abnormality is also associated with advanced stages among the patients with NSCLC, suggesting that IGFBP-3 plays an important role in lung carcinogenesis/progression and that the promoter methylation status of IGFBP-3 may be a marker for early molecular detection and/or for monitoring chemoprevention efforts.