• Title/Summary/Keyword: sensitive period

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Development of Conformal Radiotherapy with Respiratory Gate Device (호흡주기에 따른 방사선입체조형치료법의 개발)

  • Chu Sung Sil;Cho Kwang Hwan;Lee Chang Geol;Suh Chang Ok
    • Radiation Oncology Journal
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    • v.20 no.1
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    • pp.41-52
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    • 2002
  • Purpose : 3D conformal radiotherapy, the optimum dose delivered to the tumor and provided the risk of normal tissue unless marginal miss, was restricted by organ motion. For tumors in the thorax and abdomen, the planning target volume (PTV) is decided including the margin for movement of tumor volumes during treatment due to patients breathing. We designed the respiratory gating radiotherapy device (RGRD) for using during CT simulation, dose planning and beam delivery at identical breathing period conditions. Using RGRD, reducing the treatment margin for organ (thorax or abdomen) motion due to breathing and improve dose distribution for 3D conformal radiotherapy. Materials and Methods : The internal organ motion data for lung cancer patients were obtained by examining the diaphragm in the supine position to find the position dependency. We made a respiratory gating radiotherapy device (RGRD) that is composed of a strip band, drug sensor, micro switch, and a connected on-off switch in a LINAC control box. During same breathing period by RGRD, spiral CT scan, virtual simulation, and 3D dose planing for lung cancer patients were peformed, without an extended PTV margin for free breathing, and then the dose was delivered at the same positions. We calculated effective volumes and normal tissue complication probabilities (NTCP) using dose volume histograms for normal lung, and analyzed changes in doses associated with selected NTCP levels and tumor control probabilities (TCP) at these new dose levels. The effects of 3D conformal radiotherapy by RGRD were evaluated with DVH (Dose Volume Histogram), TCP, NTCP and dose statistics. Results : The average movement of a diaphragm was 1.5 cm in the supine position when patients breathed freely. Depending on the location of the tumor, the magnitude of the PTV margin needs to be extended from 1 cm to 3 cm, which can greatly increase normal tissue irradiation, and hence, results in increase of the normal tissue complications probabiliy. Simple and precise RGRD is very easy to setup on patients and is sensitive to length variation (+2 mm), it also delivers on-off information to patients and the LINAC machine. We evaluated the treatment plans of patients who had received conformal partial organ lung irradiation for the treatment of thorax malignancies. Using RGRD, the PTV margin by free breathing can be reduced about 2 cm for moving organs by breathing. TCP values are almost the same values $(4\~5\%\;increased)$ for lung cancer regardless of increasing the PTV margin to 2.0 cm but NTCP values are rapidly increased $(50\~70\%\;increased)$ for upon extending PTV margins by 2.0 cm. Conclusion : Internal organ motion due to breathing can be reduced effectively using our simple RGRD. This method can be used in clinical treatments to reduce organ motion induced margin, thereby reducing normal tissue irradiation. Using treatment planning software, the dose to normal tissues was analyzed by comparing dose statistics with and without RGRD. Potential benefits of radiotherapy derived from reduction or elimination of planning target volume (PTV) margins associated with patient breathing through the evaluation of the lung cancer patients treated with 3D conformal radiotherapy.

Studies on Controlling Mixed Annual and Perennial Weeds in Paddy Fields - On the Herbicidal Properties of Perfluidone - (수종(數種) 다년생잡초혼생답(多年生雜草混生沓)에 있어서 제초제(除草劑)에 의한 효과적(效果的)인 잡초방제(雜草防除) - Perfluidone의 작용특성구명(作用特性究明)을 중심(中心)으로 -)

  • Ryang, H.S.;Han, S.S.
    • Korean Journal of Weed Science
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    • v.3 no.1
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    • pp.75-99
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    • 1983
  • The herbicidal properties of perfluidone [1,1,1-trifluoro-N-2-methyl-4-(phenylsulponyl) phenyl methanesulfonamide] were investigated in pots and paddy fields. At the rate of 2.0kg prod./10a, perfluidone did not cause any injury to the 4 leaf stage (LS) rice seedlings. Although the crop injury increased with increasing the application rate, the injury caused by 16kg prod. perfluidone/10a gave rise to only 30% yield reduction. The crop injury was greatest when perfluidone was applied 2 days before transplanting and decreased as the application time delayed. Perfluidone showed greater crop injury to the 3 LS seedlings, at more than 7cm water depth, and at high temperature than to the 4 LS seedlings, at 3-5cm water depth, and at low temperature. Indica and indica ${\times}$ japonica rice varieties were generally more sensitive to perfluidone than japonica rice variety. Perfluidone effectively controlled most of annual weeds and such perennial weeds as Sagittaria pygmaea MIQ., Potamogeton distinctus A. BENN, Cyperus serotinus ROTTB, Scirpus maritimus L., Eleocharis kuroguwai OHWL, and Scirpus hotarui OHWL, whereas Sagittaria trifolia L. and Polygonum hydropiper SPACH. were tolerent to perfluidone. The weeding effect decreased with increasing the leaching amount of water and the overflowing of irrigated water within 24 hours after the herbicide application. When the application time was done later than 8 days after transplanting, the perennial weeds were shown at deeper soil layers, and the standing water was deeper than 7cm, the effect tended to decrease. However, there was no difference in the weeding effect between soil types. Downward movement of perfluidone in flooded soil ranged from 2 to 8cm deep. The movement increased with increasing the leaching amount of water and the application rate and at a sandy loam soil which possessed less adsorptive capacity. Residual effect of perfluidone was found at 35 to 80 days after application, which varied such factors as Soil types. Increase in the leaching amount of water resulted in decrease in the period of the residual effect. The period was shorter at non-sterilized soil than at sterilized soil. The 0.75kg ai perfluidone + 1.5kg ai SL-49 (1,3-dimethyl-6-(2,4-dichlor-benzoyl)-5-phenacyloxy-pyrazole)/ha and 1.5kg ai perfluidone + 1.05kg ai bifenox (2,4-dichlorophenyl-3-methoxy carbonyl-4-nitro phenyl ether)/ha showed less crop injury than 1.5kg ai/ha perfluidone alone. However, the weeding effect of the former was similar to that of the later.

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Changes in Serum IGF-I and Spermatogenesis Analysed by Flow Cytometry in Growing Male Rabbit (성장 중인 수토끼에서 혈청 IGF-I 수준과 Flow Cytometry 측정에 의한 정자 형성의 변화)

  • Lee J. H.;Kim C. K.;Chang Y. M.;Ryu J. W.;Park M. Y.;Chung Y. C.;Pang M. G.
    • Reproductive and Developmental Biology
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    • v.29 no.3
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    • pp.163-168
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    • 2005
  • The aim of this study was to investigate the changes in insulin-like growth factor-I (IGF-I) and growth hormone (GH) in serum, the quantitation of spermato-genesis and the comparable relationships among these measurements during pubertal period in New Zealand White male rabbits. To investigate the age-related testicular changes in DNA contents of spermatogenic cells, the fine-needle testicular biopsies from males aged 10 to 28 wks were evaluated by flow cytometry(FCM). Body weight increased significantly between the ages of 12 and 20 wks (P<0.05) and reached 3.4 kg at 28 wks of age. The highest serum IGF-I level (451.3ng/mL) was observed at 20wks of age (P<0.05) and thereafter remained stable at low levels. Serum GH level at 18 wks of age was 183.3 pg/mL which was significantly higher compared to the other ages (P<0.05), and the rising time in serum GH tend to be somewhat earlier than that of IGF-I. The relative percentage of It-cells in testicular cell compartments was $48.2\%$ at the age of 18 wks which significantly increased than those of 16-wk-old (P<0.05) and thereafter increased with the advance of age to $68\%$. The percentage of 2C-cells in testis was $26.8\%$ at 18 wks of age which was significantly lower than $54.3\%$ at 16 wks old (P<0.05). The percentage of 4C-cells was constantly maintained $2\~6\%$ except the $9.9\%$ at 18 wks of age. In conclusion, the results suggest that the puberty onset occurred at about the 18 wks of age and that the IGF-I and GH in serum during the pubertal period showed the age/growth-specific changes and these changes might be related to the spermatogenesis. The DNA FCM combined with fine-needle testicular biopsy could offer a very sensitive method to monitor the quantitative spermatogenic events related to the puberty onset.

Community Characteristics and Biological Quality Assessment on Benthic Macroinvertebrates of Bongseonsa Stream in Gwangneung Forest, South Korea (광릉숲 내 봉선사천의 저서성 대형무척추동물의 군집 특성 및 생물학적 하천평가)

  • Jung, Sang-Woo;Cho, Yong-Chan;Lee, Hwang-Goo
    • Korean Journal of Environment and Ecology
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    • v.31 no.6
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    • pp.508-519
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    • 2017
  • There have been many studies on monitoring of biodiversity changes and preservation of Gwangneung Forest Biosphere Reserve (GFBR) in South Korea in recognition of the rare ecosystem that has been preserved for a long period. However, there are few studies on diversity and community characteristics of benthic macroinvertebrates as an indicator of stream health of GFBR. The purpose of this study was to assess the water quality of Bongseonsa Stream that penetrated through Gwangneung Forest and the nearby torrents by analyzing the benthic macroinvertebrates community during April to September 2016. The investigation collected a total of 114 species of benthic macroinvertebrates belonging to 56 families, 17 orders, 8 classes, and 5 phyla from the Bongseonsa Stream and Kwangneung Stream. Ephemeroptera and Trichoptera were the largest groups in species diversity with 30 species (32.3%) and 16 species (17.2%), respectively, and Tubificidae sp., Baetis fuscatus, Antocha KUa, and Cheumatopsyche brevilineata, which usually habit in contaminated streams, appeared frequently. Among the feeding function groups, the gatherers and hunters appeared relatively frequently, and the shredders and scrapers appeared frequently in the torrents. Among the habitat oriented groups, the clingers and burrower appeared more frequently and represented the microhabitats in the shallow areas. The result of the analysis of benthic macroinvertebrates community showed that the dominant index was $0.48{\pm}0.10$ in average while it was lowest with 0.33 in GS 8 of the Gwangneung Forest torrent and highest in BS 1 of Bongseonsa Stream. The diversity and richness indices were inversely proportional to the dominant index and were 2.53 and 4.22, respectively, in GS 8 where the dominant index was low. The result of the analysis of community stability showed that area I, which had high resistance and restoration, was high in Bongseonsa Stream while the area III, which had low resistance and restoration, was high in Gwangneung Forest, indicating that the water system in Gwangneung Forest had a wider distribution of specifies sensitive to agitation. The biological water quality assessment showed ESB of $50.88{\pm}17.69$, KSI of $1.11{\pm}0.57$, and BMI of $78.55{\pm}11.05$. GS 8 of Gwangneung Forest torrent was judged to be the highest priority protective water area with the best water environment and I class water quality with ESB of 63, KSI of 0.55, and BMI of 89.9. On the contrary, BS 1 of Bongseonsa Stream was judged to be the high priority improvement area that had the lowest water quality rating of III with ESB of 25, KSI of 2.13, and BMI of 62.7. Although the diversity of water beetle was higher in the water system of nearby Bongseonsa Stream than the water system inside the Gwangneung Forest, the annual community structure appeared to have distinct differences.

Study of the seroma volume changes in the patients who underwent Accelerated Partial Breast Irradiation (부분유방방사선치료(Accelerated Partial Breast Irradiation) 환자의 장액종(Seroma) 체적 변화에 대한 연구)

  • Kim, Dae Ho;Son, Sang Jun;Mun, Jun Ki;Seo, Seok Jin;Lee, Je Hee
    • The Journal of Korean Society for Radiation Therapy
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    • v.28 no.1
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    • pp.65-75
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    • 2016
  • Purpose : By analyzing seroma volume changes in the patients who underwent Partial breast radiation therapy after breast conserving surgery, we try to contribute to the improvement of radiotherapy effect. Materials and Methods : Enrolled 20 patients who underwent partial breast radiation therapy by ViewRay MRIdian System were subject. After seeking for the size of the removed sample in the patients during surgery and obtained seroma volume changes on a weekly basis. On the Basis of acquired volume, it was compared with age, term from start of the first treatment after surgery, BMI (body mass index) and the extracted sample size during surgery. And using the ViewRay MRIdian RTP System, the figure was analyzed by PTV(=seroma volume + margin) to obtain a specific volume of the Partial breast radiation therapy. Results : The changes of seroma volume from MR simulation to the first treatment (a week) is 0~5% in 8, 5~10% in 3, 10 to 15% in 2, and 20% or more in 5 people. Two patients(A, B patient) among subjects showed the biggest change. The A patient's 100% of the prescribed dose volume is 213.08 cc, PTV is 181.93 cc, seroma volume is 15.3 cc in initial plan. However, while seroma volume decreased 65.36% to 5.3 cc, 100% of the prescribed dose volume was reduced to 3.4% to 102.43 cc and PTV also did 43.6% to 102.54 cc. In the case of the B patient, seroma volume decreased 42.57% from 20.2 cc to 11.6 cc. Because of that, 100% of the prescribed dose volume decreased 8.1% and PTV also did to 40%. Conclusion : As the period between the first therapy and surgery is shorter, the patient is elder and the size of sample is smaller than 100 cc, the change grow bigger. It is desirable to establish an adaptive plan according to each patient's changes of seroma volume through continuous observation. Because partial breast patients is more sensitive than WBRT patients about dose conformity in accordance with the volume change.

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Comparison between the method of the measurement 25 Vitamin D3 (25 Vitamin D3 측정에 있어서 화학발광미세입자 측정법과 화학발광면역 측정법 간의 비교 및 고찰)

  • Kim, dae-won;Lee, jung-hee;Jung, an-na;Seo, so-yoen
    • The Korean Journal of Nuclear Medicine Technology
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    • v.19 no.2
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    • pp.112-114
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    • 2015
  • Purpose Vitamin D to Anti- Rickets both steroid compounds showing activity, By acting on bone tissue secretary and the key to maintain serum Ca homeostasis. The blood level of vitamin D is the largest in D3 that the concentration of the metabolite is reflected in the holding state of vitamin D in vivo. Sunlight to change the 7-dehydrocholesterol in the skin and through the skin to D3, In the liver in combination with the D2 and D3 D4 changes. The Radioimmunoassay(RIA) method is measuring the D 3, the sensitivity can be measured also difficult trace substance to measure the normal test because it is very sensitive, but recently, a check is possible, for the Total D3 in Chemimicroparticle immunoassay(CMIA) or Chemiluminescent immunoassay(CLIA) measuring using microparticle RIA and CMIA(Architect i2000SR) / use the CLIA(DXI-800) method to compare and evaluate the correlation between the tests in the same test items. Materials and Methods Commissioned from January 2014 to March 2015 patients were enrolled in a total of 273 people. 29 out of 273 people conducted by RIA were compared with CMIA, 244 patients were compared with CLIA. Using reagents and equipment were used RIA(Diasource), CMIA(Architect i2000SR, Abbott Diagnostics) / CLIA( Unicel DXi-800, Beckman coulter). Results Correlation of the RIA and CLIA was a R2 = 0.1844 (y = 0.7303x + 3.9005), and the correlation of RIA CMIA is R2 = 0.2762 (y = 0.8862x + 4.56) respectively. (According to statistics, during the same period RIA is Deficiency 4.31%, Insufficiency 90.53%, Sufficiency 5.16%, was Excess 0%, CLIA / CMIA is Deficiency 17.02%, Insufficiency 75.91%, Sufficiency 7.03%, indicating the distribution of 0.03 % Excess) Conclusion Serum vitamin D and parathyroid hormone that show an inverse relationship, the level above which are not parathyroid hormone and vitamin D reduced the increase. The density is different for each study, at most 20 is reported to be the maximum between 30 ng / ml. In Korea it requires a proposed standard of vitamin D deficiency, reference to the WHO lack the case more than 10ng/ml, 20ng/ml and defined by the lack of, if not more than, the IOM, but looking at 12ng/ml or less to the normal to lack, at least 20ng/ml, the reference do not match the deficit under 20ng/ml, 21-29ng/ml relative lack between, was also defined as a sufficient condition for more than 30ng/ml. Although not statistically is between RIA and CLIA two ways to vitamin D levels change according to season match, when seasonally seen in summer as commonly known (April to September), winter (October to March) relative to the increase measured than it was found. Finally, the study on the correlation between the two methods have been expected to result in a consistent and apply the same view high reference value on the graph is difficult. However, there may be differences between the test equipment and methods, and could be especially the case of RIA method using an organic solvent is difficult to compare different methods and correlated view similar trend in vitamin D deficiency and quarterly aspect ratio.

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Human Lung Cancer Cell Xenografts Implanted under the Capsule of Kidney, Spleen and Liver (폐암 세포주를 사용한 신, 비장 및 간 피막하 분식법의 비교)

  • 김수현;김종인;이해영;조봉균;박성달;김송명
    • Journal of Chest Surgery
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    • v.36 no.10
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    • pp.711-720
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    • 2003
  • Bakground : Complete resection by the surgery has been selected as the treatment of choice in lung cancer patients, but in cases of recurrence after excision or inoperable cases, the importance of anticancer chemotherapy has been emphasized. If one can select a set of the sensitive chemotherapeutic agents before anticancer chemotherapy, it will give more favourable results. Subrenal capsular assay has been recognized as a useful in-vivo chemosensitivity test of thoracic and abdominal tumors and it can be done in a short time for a rapid interpretation of tumor responsiveness to anticancer chemotherapeutic drugs. It has been reported that various kinds of cancer cells can be implantable to the kidney, but so far there is no comparative study of xenogeneic cell implantation on liver, spleen and kidney. The author implanted the human lung cancer cells under the capsule of S.D rat's liver, spleen and kidney respectively and compared the pattern of growth and histology. Material and Method: After incubation of human lung cancer cell line (SW-900 G IV) in RPMI 1640 (Leibovitz L-15 medium) culture media, 3${\times}$3${\times}$3 mm size fibrin clots which contain 108 cancer cells were made. Thereafter the fibrin clots were implanted at subcapsule area of liver, spleen and kidney of S.D. female rat. For immune suppression, cyclosporin-A (80 mg/Kg) was injected subcutaneously daily from post-implantation first day to sixth day. The body weight was measured at pre and post implantation periods. The growth pattern and the size of tumor mass were observed and the pathologic examination and serum tumor marker tests were performed. Result: Body weight increased in both of control and experimental groups. Serum Cyfra 21-1 was not detected. Serum levels of CEA and NSE revealed no significant change. The SCC-Ag increased significantly in implanted group. The growth rate of human lung cancer cells which was implanted on spleen was higher than on liver or kidney. The surface area, thickness, and volume of tumor mass were predominant at spleen. The success rates of implantation were 80% on kidney, 76.7% on spleen and 43.3% on liver. Pathologic examination of implanted tumors showed characteristic findings according to different organs. Tumors that were implanted on kidney grew in a round shape, small and regular pattern. In the spleen, tumors grew well and microscopic neovascularization and tumor thrombi were also found, but the growth pattern was irregular representing frequent daughter mass. Human lung cancer cells that were implanted in the liver, invaded to the liver parenchyme, and had low success rate of implantation. Microscopically, coagulation necrosis and myxoid fibrous lesion were observed. Conclusion: The success rate of implantation was highest in the kidney. And the mass revealed regular growth that could be measured easily. The SCC-Ag was presented earlier than CEA or Cyfra21-1. The Cyfra21-1 was not detected at early time after implantation. The best model for tumor implantation experiment for chemosensitivity test was subrenal capsular analysis than liver and spleen and the useful serum tumor marker in early period of implantation was the SCC-Ag.

DISEASE DIAGNOSED AND DESCRIBED BY NIRS

  • Tsenkova, Roumiana N.
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 2001.06a
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    • pp.1031-1031
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    • 2001
  • The mammary gland is made up of remarkably sensitive tissue, which has the capability of producing a large volume of secretion, milk, under normal or healthy conditions. When bacteria enter the gland and establish an infection (mastitis), inflammation is initiated accompanied by an influx of white cells from the blood stream, by altered secretory function, and changes in the volume and composition of secretion. Cell numbers in milk are closely associated with inflammation and udder health. These somatic cell counts (SCC) are accepted as the international standard measurement of milk quality in dairy and for mastitis diagnosis. NIR Spectra of unhomogenized composite milk samples from 14 cows (healthy and mastitic), 7days after parturition and during the next 30 days of lactation were measured. Different multivariate analysis techniques were used to diagnose the disease at very early stage and determine how the spectral properties of milk vary with its composition and animal health. PLS model for prediction of somatic cell count (SCC) based on NIR milk spectra was made. The best accuracy of determination for the 1100-2500nm range was found using smoothed absorbance data and 10 PLS factors. The standard error of prediction for independent validation set of samples was 0.382, correlation coefficient 0.854 and the variation coefficient 7.63%. It has been found that SCC determination by NIR milk spectra was indirect and based on the related changes in milk composition. From the spectral changes, we learned that when mastitis occurred, the most significant factors that simultaneously influenced milk spectra were alteration of milk proteins and changes in ionic concentration of milk. It was consistent with the results we obtained further when applied 2DCOS. Two-dimensional correlation analysis of NIR milk spectra was done to assess the changes in milk composition, which occur when somatic cell count (SCC) levels vary. The synchronous correlation map revealed that when SCC increases, protein levels increase while water and lactose levels decrease. Results from the analysis of the asynchronous plot indicated that changes in water and fat absorptions occur before other milk components. In addition, the technique was used to assess the changes in milk during a period when SCC levels do not vary appreciably. Results indicated that milk components are in equilibrium and no appreciable change in a given component was seen with respect to another. This was found in both healthy and mastitic animals. However, milk components were found to vary with SCC content regardless of the range considered. This important finding demonstrates that 2-D correlation analysis may be used to track even subtle changes in milk composition in individual cows. To find out the right threshold for SCC when used for mastitis diagnosis at cow level, classification of milk samples was performed using soft independent modeling of class analogy (SIMCA) and different spectral data pretreatment. Two levels of SCC - 200 000 cells/$m\ell$ and 300 000 cells/$m\ell$, respectively, were set up and compared as thresholds to discriminate between healthy and mastitic cows. The best detection accuracy was found with 200 000 cells/$m\ell$ as threshold for mastitis and smoothed absorbance data: - 98% of the milk samples in the calibration set and 87% of the samples in the independent test set were correctly classified. When the spectral information was studied it was found that the successful mastitis diagnosis was based on reviling the spectral changes related to the corresponding changes in milk composition. NIRS combined with different ways of spectral data ruining can provide faster and nondestructive alternative to current methods for mastitis diagnosis and a new inside into disease understanding at molecular level.

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Consideration About the Bacterial Endotoxin Test Showing False Positive Test Result When Performing LAL Test (LAL Test에서 위양성을 나타내는 원인들에 대한 고찰)

  • Hwang, Ki-Young;Cho, Yong-Hyun;Lee, Yong-Suk;Kim, Hyung-Woo;Lee, Hong-Jae;Kim, Hyun-Ju
    • The Korean Journal of Nuclear Medicine Technology
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    • v.13 no.3
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    • pp.156-158
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    • 2009
  • Purpose: Since radiopharmaceuticals are intended for human administration, it is imperative that we should undergo quality control very strictly. Now almost all the PET laboratories have adopted Bacterial Endotoxin Test as the stand quality control method to monitor whether pyrogen is free or not in the product vial containing crude solution. The aim of this study is to find out the reason why false positive result is observed when using commercially available test vial. Materials and Methods: For this experiment, we used commercially available single test kit (Associates of Cape Code. Inc. USA) and we made pH samples by mixing each buffer whose pH ranges are 1.0 to 12.0. Otherwise we made Ethanol samples diluted with distilled water. After making test samples, it added 0.2 mL to the test vial. Assay mixture in the test vial was incubated in a water bath (Chang Shin Co. KOR) for 60 min at $35{\pm}2^{\circ}C$. Results: After incubation period ($60{\pm}1^{\circ}C$), we inverted the test vial about $180^{\circ}$ To know what pH and how many percentage of Ethanol (Fisher Scientific Korea. Ltd) will affect the reaction. With pH buffer, false positive result was observed at pH 1.0 to 5.0 and 7.7 to 12.6 but at pH 5.2 to.7.5, the test results show negative. It's very strange that we couldn't observe negative test result with Tris buffer at pH 8.4, 8.6, 8.8, 9.0. in other case Ethanol, the test result was seen with 5 to 10% Ethanol. But to my surprise we could see very thick gel formation with 100% Ethanol. Conclusions: In this study, we could notice that pH which is too much acidic or alkalic or high concentrated Ethanol would affect Bacterial Endotoxin Test result. As you know, LAL test is sensitive and very reliable method. Therefore, we are needed to elicit the accurate test result as possible as we can.

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Clinical characteristics and risk factors for staphylococcal infections in neonatal intensive care unit (신생아 중환자실에서 포도알균 감염에 대한 임상적 고찰과 위험 요인 조사)

  • Chung, Min Kook;Choi, Jeong Ho;Chang, Jin Keun;Chung, Sung Hoon;Bae, Chong Woo;Cha, Sung Ho
    • Clinical and Experimental Pediatrics
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    • v.49 no.12
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    • pp.1287-1295
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    • 2006
  • Purpose : The importance of staphylococcal infections in NICU has been emphasized in terms of increased resistant strains and increased incidence of morbidity and mortality. In this study, we inrestignted the clinical characteristics and risk factors for staphylococcal infections, and looked into sensitivity trends of antibiotics in the era of a high rate of methicillin-resistant staphylococcus aureus (MRSA) in our society. Methods : This study included 240 neonates with positive blood, urine and other sites cultures for staphylococci who were admitted to NICU of Hanil General Hospital and Kyunghee University Hospital from January 2000 to December 2004. The analyses included clinical characteristics of staphylococcal infections and the relationship of incidence rate among various factors, including invasive procedures. Results : For 5 years, 3,593 patients were hospitalized in the NICU and 7,481 specimens were cultured from blood, urine, and other sites. During the study period, staphylococci were isolated from 240 patients, of whom 88 patients had MRSA, 41 patients methcillin sensitive staphylococcus aureus (MSSA), 63 patients S. epidermidis, 48 patients coagulase-negative staphylococcus (CNS) except S. epidermidis infections. The risk factors associated with staphylococcal infections were less than 37 weeks of gestational age, less than 7 on a 5 minutes Apgar score, receiving TPN, applied mechanical ventilation, use of central venous catheters and other tubes. The sensitivity to vancomycin was 100 percent. A relatively high sensitivity against teicoplanin, trimethoprim-sulfamethoxazole, chloramphenicol, clindamycin and low sensitivity against gentamicin and erythromycin were shown. Conclusion : To reduce staphylococcal infections in NICU, we need to monitor and manage premature neonates from the beginning of the birth process and to avoid as many invasive procedures as possible in NICU. Considering MRSA, control of preceding factors and early use of appropriate antibiotics is expected to reduce the morbidity and mortality caused by MRSA infections.