Enhancement of bio-stability and mechanical properties of hyaluronic acid hydrogels by tannic acid treatment

Lee, Ho-Yong,Hwang, Chang-Ha,Kim, Hyoun-Ee,Jeong, Seol-Ha Elsevier 2018 Carbohydrate Polymers Vol.186 No.-

<P><B>Abstract</B></P> <P>Hyaluronic acid (HA) has been widely investigated because of its excellent biocompatibility and its ability to form hydrogels with various chemical modifications. However, HA hydrogels undergo rapid degradation and exhibit poor mechanical stability under physiological conditions. Tannic acid (TA), a naturally occurring polyphenol found in plants and fruits, has recently attracted interest as a crosslinking agent because of its abundant hydroxyl groups. In this study, we prepared HA hydrogels chemically crosslinked by polyethylene glycol diglycidyl ether (PEGDE) and treated with TA in an attempt to enhance the physical properties of HA hydrogels. TA acts as a physical crosslinker owing to the strong hydrogen bonding between TA and PEGDE, resulting in improved mechanical properties that support both cell attachment and proliferation without any sign of cytotoxicity. The enzymatic stability of the HA–TA hydrogels was significantly enhanced with the addition of TA, which was attributed to the hyaluronidase inhibition activity of TA. Additionally, the antioxidant potential of TA resulted in good resistance to degradation by reactive oxygen species, which can be generated in human tissues.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Crosslinking strategy of hyaluronic acid by using polyethylene glycol and tannic acid is proposed. </LI> <LI> Superior bio-stability and mechanical properties of hyaluronic acid hydrogels are obtained. </LI> <LI> Enhanced biological responses of hyaluronic acid- tannic acid hydrogel are achieved. </LI> </UL> </P>

Prednisolone 投與로 因한 家兎中樞淋巴組織의 形態學的硏究

河在昌,李東久,洪錫宰 啓明大學校 醫科大學 1982 계명의대학술지 Vol.1 No.1

成熟家兎를 實驗動物로 하여 prednisolone 을 5㎎ 및 10㎎ 씩 1日 1回 連 3日間 注射하고 中樞淋巴組織인 胸腺과 蟲垂淋巴組織에 惹起되는 變化를 機能的組織構造에 따라 光學 및 電子顯微鏡的으로 檢索한 結果를 要約하면 다음과 같다. 組織學的으로 胸腺에 있어서는 小葉皮質에서 淋巴球의 甚한 消失과 細綱細胞 및 大食細胞의 顯著한 增加를 볼 수 있었으나 隨質에서는 淋巴球가 거의 減少되지 않았다. 蟲垂淋巴組織은 dome, corooa 및 follicle에서 다같이 大小淋巴球의 甚한 消失과 大食細胞의 著明한 增加를 볼 수 있었으며 TDA에서는 淋巴球가 極히 輕한 程度로 減少하였을 뿐으로서 거의 正常한 狀態로 보였다. 電子顯微鏡的으로 胸腺皮質의 淋巴球는 核邊綠의 不規則, 核膜의 消失 및 核破壞 等의 甚한 變性 내지 壞死性變化가 惹起되었으며 細綱細胞 및 大食細胞에서는 空胞의 養性擴張, mitochondria의 종신 및 cristae의 消失 그리고 破壞된 淋巴球의 탐식 等이 5㎎ 注射群보다는 10㎎ 群에서 좀 더 顯著하게 나타났다. 그러나 隨質에서는 몇몇 淋巴球에서 核濃縮과 核邊綠의 不規則性이 있을뿐 著明한 變性變化는 없었다. 蟲垂淋巴組織에서도 dome, corona 및 follicle의 淋巴球는 甚한 壞死性變化를 보였으며 TDA에서는 그 變化가 極히 輕하였다. Dome 및 follicle의 大食細胞에서는 破壞된 淋巴球가 가끔 탐식되어 있었다. 以上의 成績으로 보아 一般的으로 cortiosteroid의 中樞淋巴組織에 對한 影響은 胸腺에서는 皮質의 淋巴球에 그리고 蟲垂淋巴組織에서는 주로 B淋巴球領域의 淋巴球에 일어나며 그 變化는 非可逆性 壞死까지도 誘發하는 것으로 推定된다. This study was carried out to investigate morphological changes in the central lymphoid tissue of thymus gland and appendix of 12 healthy adult rabbits treated with injecting prednisolone of 5 and 10mg each to the animals once per day 3 consecutive days. The results were as follows: Light microscopically, a considerable loss of lymphocytes in lobular cortex of thymus gland, along with noticeable increase of macrophages and reticulum cells, were found. However, no significant decrease of lymphocytes in its medulla persent. Significant loss of large and small lymphocytes and considerable increased macrophages in the areas of dome, corona, and follicles of appendiceal lymphoid tissue were noted. However, very meagre decrease of lymphocytes in thymus dependent area only was noticed. Electron microscopically marked degeneration and necrotic changes of lymphocytes, such as irregularity of nulear margin, loss of nuclear membrane, and destruction of lymphocytes in the cortex of thymus gland occured. in reticulum cells and macrophages, cystic degeneration of vesicles, swelling of mitochondria, loss of cristae, and phagocytosis of destructed lymphocytes were prominent in the group of 10mg injection than in that of 5mg. Nevertheless, nuclear condensations and irregularities of nuclear margin of some lymphocytes were noticed in medulla with no clear degenerative changes. In appendiceal lymphoid tissue, a severe nocrotic changes of lymphocytes of dome, corona and follicles were observed. However, its changes in thymus dependent area were very little. In macrophages of dome and follicles, destructed lymphocytes were seen to be occasionally phagocytosed. It may be summarized that the effects of corticosteroid on the central lymphoid tissue take place in lymphocytes in cortex of thymus gland and in lymphocytes of B lymphocytical area of appendiceal lymphoid tissue. It may also be assumed that the changes aforementioned can include irreversible necrosis.

정신분열병에 대한 리스페리돈의 효과 및 안정성

이민수,김용구,김영훈,연병길,오병훈,윤도준,윤진상,이철,정희연,강병조,김광수,김동언,김명정,김상훈,김희철,나철,노승호,민경준,박기창,박두병,백기청,백인호,손봉기,손진욱,양병환,양창국,우행원,이정호,이종범,이홍식,임기영,전태연,정영조,정영철,정인과,정인원,지익성,채정호,한상익,한선호,한진희,서광윤 大韓神經精神醫學會 1998 신경정신의학 Vol.37 No.1

연구목적 : 본 시험의 목적은 임상시험 시작전에 연구자들을 대상으로 PANSS Workshop을 통하여 PANSS, ESRS에 대한 국내에서의 표준화 작업을 구축하고 새로운 정신병 치료제인 리스페리돈의 효과와 안정성을 재확인하여 리스페리돈 사용에 대한 적정화를 이루는데 있다. 연구방법 : 1996년 4월부터 1996년 9월까지 국내 39개 대학병원 정신과에 입원중인 혹은 증상이 악화되어 입원하는 정신분열병 환자 377명을 대상으로 다시설 개방 연구를 시행하였다. 1주일간의 약물 배설기간을 가진후, 리스페리돈을 8주간 투여하였고, 기준점, 1주, 2주, 4주, 그리고 8주후에 평가되었다. 용량은 제1일에는 리스페리돈 1mg씩 1일 2회, 제2일에는 2mg씩 1일 2회, 제3∼7일에는 3mg씩 1일 2회 투여하였다. 이후 환자의 임상상태에 따라 임의로 증량할 수 있으며, 최대 일일 16mg을 초과하지 않도록 하였다. 추체외로 증상을 조절하기 위한 투약을 허용하였다. 임상증상 및 부작용의 평가는 PANSS(Positive and Negative Syndrome Scale), CGI(Clinical Global Impression) 그리고 ESRS(Extrapyramidal Symptom Rating Scale)을 사용하였다. 연구결과 : 377명중 343명(91%)이 8주간의 연구를 완결하였다. 치료 종결시점인 8주후 PANSS 총점수가 20% 이상 호전된 경우를 약물 반응군으로 정의할때, 약물반응군은 81.3%였다. 리스페리돈에 반응하는 예측인자로는 발병연령, 이전의 입원 횟수, 유병기간이 관련 있었다. 리스페리돈은 1주후부터 PANSS양성, 음성, 및 일반정신병리 점수상에 유의한 호전을 보여 효과가 빨랐다. CGI의 경우도 기준점에 비해 1주후부터 유의한 감소를 나타내었다. ESRS의 경우, 파킨슨 평가점수는 기준점과 비교해 투여 1주, 2주, 4주후 유의하게 증가되었다가 8주후 기준점과 차이가 없었다. Dystonia 평가점수는 1주후만 유의한 증가를 보였으며, dyskinesia 평가점수는 유의한 차이가 없었다. 혈압, 맥박수의 생명징후 및 일반 혈액학 검사, 생화학적 검사, 심전도 검사에서 유의한 변화는 없었다. 결 론 : 이상의 다시설 개방 임상 연구를 통해 리스페리돈은 정신분열병 환자에서 양성증상뿐만 아니라 음성증상 및 전반적인 증상에도 효과적인 것으로 사료된다. 보다 명확한 평가를 위해서는 다른 항정신병약물과의 이중맹검 연구가 필요할 것으로 생각되며, 또한 장기적 치료에 대한 평가도 함께 이루어져야 하겠다. Objective : The purpose of this study was to investigate the efficacy and safety of risperidone in the treatment of Korean schizophrenic patients. Method : This multicenter open study included 377 schizophrenic patients drawn from 39 university hospitals. After a wash-out period of 1 week, the schizophrenic patients were treated with risperidone for 8 weeks and evaluated at 5 points ; at baseline, and 1, 2, 4 and 8 weeks of treatment. The dose was increased from 2mg/day(1mg twice daily) to 6mg/day(3mg twice daily) during the first week and adjusted to a maximum of 16mg/day over the next 7 weeks according to the patient's clinical response. Medication to control extrapyramidal symptoms was permitted. The psychiatric and neurological status of the patients was assessed by PANSS, CGI, and ESRS scales. Results : 343(91%) of 377 patients completed the 8-week trial period. Clinical improvement, as defined by a 20% or more reduction in total PANSS score at end point, was shown by 81.3% of patients. The predictors of response to risperidone were associated older age, shorter duration of illness, fewer previous hospitalization. Risperidone had rapid onset of action ; a significant decrease of the total PANSS and three PANSS factor(positive, negative, general), and CGI was already noticed at the end of first week. For the ESRS, parkinsonism rating scores were significantly increased until week 4 comparing with baseline. Dystonia rating scores were significantly increased until week 1, and dyskinesia rating scores were not significantly changed during the study. Laboratory parameters including vital sign, EKG, hematological, and biochemical values showed no significant changes during the trial. Conclusions : This study suggests that risperidone is generally safe and effective against both the positive and negative symptoms in our group of patients.

Bloodstream Infections and Clinical Significance of Healthcare-associated Bacteremia: A Multicenter Surveillance Study in Korean Hospitals

Son, Jun Seong,Song, Jae-Hoon,Ko, Kwan Soo,Yeom, Joon Sup,Ki, Hyun Kyun,Kim, Shin-Woo,Chang, Hyun-Ha,Ryu, Seong Yeol,Kim, Yeon-Sook,Jung, Sook-In,Shin, Sang Yop,Oh, Hee Bok,Lee, Yeong Seon,Chung, Doo The Korean Academy of Medical Sciences 2010 JOURNAL OF KOREAN MEDICAL SCIENCE Vol.25 No.7

<P>Recent changes in healthcare systems have changed the epidemiologic paradigms in many infectious fields including bloodstream infection (BSI). We compared clinical characteristics of community-acquired (CA), hospital-acquired (HA), and healthcare-associated (HCA) BSI. We performed a prospective nationwide multicenter surveillance study from 9 university hospitals in Korea. Total 1,605 blood isolates were collected from 2006 to 2007, and 1,144 isolates were considered true pathogens. HA-BSI accounted for 48.8%, CA-BSI for 33.2%, and HCA-BSI for 18.0%. HA-BSI and HCA-BSI were more likely to have severe comorbidities. <I>Escherichia coli</I> was the most common isolate in CA-BSI (47.1%) and HCA-BSI (27.2%). In contrast, <I>Staphylococcus aureus</I> (15.2%), coagulase-negative <I>Staphylococcus</I> (15.1%) were the common isolates in HA-BSI. The rate of appropriate empiric antimicrobial therapy was the highest in CA-BSI (89.0%) followed by HCA-BSI (76.4%), and HA-BSI (75.0%). The 30-day mortality rate was the highest in HA-BSI (23.0%) followed by HCA-BSI (18.4%), and CA-BSI (10.2%). High Pitt score and inappropriate empirical antibiotic therapy were the independent risk factors for mortality by multivariate analysis. In conclusion, the present data suggest that clinical features, outcome, and microbiologic features of causative pathogens vary by origin of BSI. Especially, HCA-BSI shows unique clinical characteristics, which should be considered a distinct category for more appropriate antibiotic treatment.</P>

척수손상후 운동 유발전위와 지각 유발전위의 비교

지철,이재수,하영수,최창락,송진언 대한신경외과학회 1987 Journal of Korean neurosurgical society Vol.16 No.4

Electrical monitoring of the nervous system offers the potential for the detection of injury, intraoperatively. The relationship of MEP(Motor Evoked Potential) and SEP(Sensory Evoked Potential) taken in 30 rats before and after spinal cord injury is reported. MEP was obtained from distal portion to the site of spinal cord injury by electrical stimulation of the cerebral motor cortex after insertion of a ball electrode in the cerebral motor cortex. SEP was collected at the cerebral somatosensory cortex during the sciatic nerve stimulation. Experimental animals were divided into a 20g㎝ spinal cord-trauma group and 50g㎝ spinal cord-trauma group. Changes of cardiopulmonary function after cerebral motor cortex stimulation and pre-and post-injury MEP and SEP were obtained at constant time interval. The results were follows : 1) Significant changes in blood pressure, pulse rate, and respiratory rate were noted to be elevated after stimulation of cerebral motor cortex and these were returned to normal in 10 minutes after stimulation. 2) MEP in control group showed that the latency was 8.6±1.54msec and the amplitude was 20.60±3.2㎶. In MEP of 20g㎝ spinal cord trauma group, the latency was increased to 30% (11.26±1.76msec) compared to control group at 10 minutes after the injury and the amplitude was decreased to 29% (14.60±2.99㎶). The latency was slowly decreased with the passage of time, to 21% increase. (10.42±1.84msec) at 1 hour after injury but the amplitude was not changed. In 50 g㎝ spinal cord-trauma group the latency was decreased to 75%(4.9±1.52㎶) compared to control group. With the passage of time, no change was revealed in latency but amplitude was decreased. The amplitude was decreased to 80%(4.00±1.49㎶) compared to control group. Change of MEP was marked in 50g㎝ spinal cord-trauma group. With the passage of time MEP was slightly improved in 20g㎝ spinal cord-trauma group but deteriorated in 50g㎝ spinal cord-trauma group. 3) The latency of SEP in control group was 12.22±0.7msec and the amplitude of those was 20.00±2.21㎶. No significant statistical change was recorded in the SEP of each spinal cord-trauma group compared to control group. MEP might be more important indicator than SEP in estimation and evaluation of the functional change of spinal cord injury.

교정환자에 있어 chlorhexidine varnish 처치 전후의 차태내 균주변화에 관한 연구

장영일,이하진 대한치과교정학회 1997 대한치과교정학회지 Vol.27 No.2

본 연구는 교정환자를 대상으로 chlorhexidine varnish를 치면에 도포했을 때 치태내 균주의 변화양상을 관찰하여 교정치료환자에 있어 치아우식증예방을 위한 chlorhexidine 사용의 효용성을 평가하고자 하는데 그 목적이 있다. 서울대학교 병원 치과진료부 교정과에 내원한 신환 26명을 대상으로 각 13명씩을 실험군과 대조군으로 구분하여 실험군에는 chlorhexidine varnish를 1주일 가격으로 4회 도포하고 대조군에는 같은 방법으로 placebo varnish를 도포하여 처치 전과 처치 4주후, 처치 8주후의 치태내 균주 변화양상을 간접면역형광현미경법으로 분석하였다. 결과는 다음과 같다. 1. Chlorhexidine varnish 처치에 의해 Streptococcus mutans는 처치 8주후 까지 강력히 억제되었다(p<0.01). 2. Streptococcus sanguis는 chlorhexidine varnish처치 4주후에 일시적으로 증가하였다가(p<0.05) 8주후에 원상으로 회복되었다. 3. Streptococcus mitis, Actinomyces viscosus, Actinomyces naeslundii는 chlorhexidine varnish 처치에 의해 별 다른 변화를 나타내지 않았다. The purpose of this study was to evaluate the effectiveness of chlorhexidine varnish treatment in the prevention of dental caries in orthodontic patients by observing microbial change in dental plaque after varnish treatment. The sample consisted of 26 patients who were classified into an experimental group and a control group, 13 patients each. The experimental group was treated with chlorhexidine varnish once a week for 4 weeks. The control group was treated with placebo varnish using the same procedure. The microbial change was analysed by indirect immunofluorescence technique before treatment and 4 weeks, 8 weeks after treatment. The results were as follows. 1. Streptococcus mutans were strongly suppressed until 8 weeks after chlorhexidine varnish treatment(p<0.01). 2. The proportion of Streptococcus sanguis increased temporarily 4 weeks after chlorhexidine varnish treatment(p<0.05), decreased to original level after 8 weeks. 3. Streptococcus mitis, Actinomyces viscosus, Actinomyces naeslundii did not sho significant change after chlorhexidine varnish treatment.

Nutrikinetics of Isoflavone Metabolites After Fermented Soybean Product (Cheonggukjang) Ingestion in Ovariectomized Mice

Lee, Da‐,Hye,Kim, Min Jung,Ahn, Jiyun,Lee, Sang Hee,Lee, Hyunjung,Kim, Jin Hee,Park, So‐,Hyun,Jang, Young‐,Jin,Ha, Tae‐,Youl,Jung, Chang Hwa John Wiley and Sons Inc. 2017 Molecular Nutrition & Food Research (Print) Vol.61 No.12

<P><B>Scope</B></P><P>Cheonggukjang (CGJ) is a soybean‐based quick‐fermented food popular in Korea that contains a variety of biologically active compounds including isoflavones and saponins. Isoflavone bioavailability may be important for the bone health of postmenopausal women; therefore, the aim of this study is to evaluate the influence of fermentation on the isoflavone metabolite nutrikinetic profile after single dose CGJ or unfermented soybean administration in ovariectomized (OVX) and sham mice.</P><P><B>Methods and results</B></P><P>We identify 34 isoflavone metabolites using UPLC–QTOF‐MS and analyze their nutrikinetics at different time points (0.25, 0.5, 1, 2, 4, 8, 16, and 24 h) to understand their fermentation‐ and OVX‐mediated time‐dependent concentration changes. Nutrikinetics analysis shows that genistein, daidzein, genistein 4′‐sulfate, dihydrodaidzein sulfate, equol 4′‐sulfate, and equol‐7‐glucuronide are present at high concentrations in all groups based on area‐under‐the‐curve analysis. OVX mice appear to show lower isoflavone bioavailability than mice in the sham group. CGJ enhances various isoflavone metabolite bioavailability including genistein, 3‐hydroxygenistein, and equol 7‐glucuronide, compared to the unfermented soybean‐treated group. Among these metabolites, intact isoflavones, 3‐hydroxygenistein, genistein 4′‐sulfate, and equol 7‐glucuronide promote osteoblastogenesis and inhibit osteoclast formation.</P><P><B>Conclusions</B></P><P>CGJ has good isoflavone bioavailability and may be beneficial for the bone health of postmenopausal women.</P>

柔軟性에 의한 제조시스템의 評價 模型

하정진,이창섭,김성희 동아대학교 공과대학 부설 한국자원개발연구소 1993 硏究報告 Vol.17 No.2

Flexibility has become a key objectives in the design of manufacturing systems and a critical measure of total manufacturing performance. The need for flexibility is increasing due to some environmental change such a changing technical characteristics of the products and the changing nature of market demands. Most importantly, flexibility embodies competitive value for a manufacturer. Therefore, the objective of this research is to offer a definition of flexibility as well as proposing a scheme for assessing the value of flexibility, one of the performance measures of manufacturing systems.

경북 최초의 신장이식 1례

이중현,김용섭,이정호,이창우,김상욱,이문섭,오민구,하달봉,이경섭 동국대학교 의학연구소 2000 東國醫學 Vol.7 No.-

신장이식은 환자의 삶의 질을 높이고 거의 정상적인 사회생활을 가능하게 함으로써 말기신부전 환자의 3가지 신대체 요법(혈액투석, 복막투석, 신장이식) 중에 가장 효과적이고 각광받는 치료법이라 할 수 있다. 최근 들어 의료기술과 의학의 발달로 신장이식의 성공률은 과거에 비해 비약적으로 높아지고 있으며 국내에서도 점차 신장이식수술을 받는 환자가 증가하고 있으나 서울이나 다른 대도시에 비해 의료환경이 열악한 중소도시나 지방의 병원에서는 아직도 시행하지 못하고 있는 형편이다. 이에 저자들은 경북 최초로 자체 의료진에 의해 고혈압과 말기 신부전으로 동국대 포항병원에서 혈액투석을 받고 있던 32세의 남자환자에게 부인으로부터 신장을 제공받아 신장이식을 성공적으로 시행하였기에 문헌고찰과 함께 보고하고자 한다. Kidney transplantation is the preferred treatment modality for many patients with end-stage renal disease (ESRD), because it offers improved quality of life over both hemodialysis and peritoneal dialysis. Patients who do well after transplantation generally report improvement in vitality and freedom to return to the style of life that they experienced before their progression to ESRD. Recently, the success rate of kidney transplantation is greatly being increased as the surgical technique and immunosuppressive drugs are developed. Kidney transplantation is also popular in Korea which has good result. But, until now the general hospitals which are located at small city can't try the kidney transplantation because they don't have proper facilities and experts. We firstly experienced a case of kidney transplantation in a 32 years old man with hypertension and chronic renal failure at KyoungBuk province. So we report this case with references.

Reducing Phosphorus Release from Paddy Soil by Coal Ash and Phospho-Gypsum Mixture

Lee, Chang Hoon,Lee, Yong Bok,Lee, Hyub,Ha, Byung Yun,Kim, Pil Joo 한국환경농학회 2005 한국환경농학회지 Vol.24 No.1

As a silicate source to rice, a coal ash was selected and mixed with phosphor-gypsum (50:50, wt wt^(-1)) to reduce the potential of boron toxicity and to supply calcium element We expected that high con-tent of calcium in this mixture might convert water-soluble phosphorus to less soluble forms and then reduce the release of soil phosphorus to surface runoff. The mixture was applied with the rate of 0, 20, 40, and 60 Mg ha^(-1) in paddy soil (Nagdong series, a somewhat excessively drained loamy fine sand) in Daegok, Jinju, Korea The mixture reduced significantly water-soluble phosphorus (W-P) in the surface soils by shifting from W-P and Fe-P to Ca-P and Al-P during whole rice cultivation. In contrast with W-P, plant available phosphorus increased significantly with the mixture application due to high content of phosphorus and silicate in the mixture. The mixture of coal ash and phosphor-gypsum (50:50, wt wt^(-1)) would be a good alternative to reduce a phosphorus export in rice paddy soil together with increasing rice yields.