Bucillamine prevents cisplatin-induced ototoxicity through induction of glutathione and antioxidant genes

Kim, Se-Jin,Ho Hur, Joon,Park, Channy,Kim, Hyung-Jin,Oh, Gi-Su,Lee, Joon No,Yoo, Su-Jin,Choe, Seong-Kyu,So, Hong-Seob,Lim, David J,Moon, Sung K,Park, Raekil Nature Publishing Group 2015 Experimental and molecular medicine Vol.47 No.2

<P>Bucillamine is used for the treatment of rheumatoid arthritis. This study investigated the protective effects of bucillamine against cisplatin-induced damage in auditory cells, the organ of Corti from postnatal rats (P2) and adult Balb/C mice. Cisplatin increases the catalytic activity of caspase-3 and caspase-8 proteases and the production of free radicals, which were significantly suppressed by pretreatment with bucillamine. Bucillamine induces the intranuclear translocation of Nrf2 and thereby increases the expression of γ-glutamylcysteine synthetase (γ-GCS) and glutathione synthetase (GSS), which further induces intracellular antioxidant glutathione (GSH), heme oxygenase 1 (HO-1) and superoxide dismutase 2 (SOD2). However, knockdown studies of HO-1 and SOD2 suggest that the protective effect of bucillamine against cisplatin is independent of the enzymatic activity of HO-1 and SOD. Furthermore, pretreatment with bucillamine protects sensory hair cells on organ of Corti explants from cisplatin-induced cytotoxicity concomitantly with inhibition of caspase-3 activation. The auditory-brainstem-evoked response of cisplatin-injected mice shows marked increases in hearing threshold shifts, which was markedly suppressed by pretreatment with bucillamine <I>in vivo</I>. Taken together, bucillamine protects sensory hair cells from cisplatin through a scavenging effect on itself, as well as the induction of intracellular GSH.</P>

Chemical Properties and Nutrient Loadings of Rainwater during Farming Season

Min-Kyeong Kim,Seong-Chang Hong,Jong-Sik Lee,Goo-Buk Jung,Soon-Ik Kwon,Mi-Jin Chae,Sun-Gang Yun,Kyu-Ho So 한국토양비료학회 2013 한국토양비료학회지 Vol.46 No.5

Recently, special attention has been given to acid rain and its problem to environment such as acid precipitation and air pollution in East Asia. In the present study, rainwater samples were collected from Apr to Nov in 2012. The samples were chemically characterized for the assessment of emission sources. Suwon and Yeoju regions, typical agricultural areas in South Korea, were chosen for study sites. Ion composition and cation-affected neutralization were determined to evaluate the contribution of cations to the acidity of rainwater. Ion and electrical conductivity between the measured and the estimated showed high correlation. The cations observed in Suwon and Yeoju were Na<SUP>+</SUP> > NH4<SUP>+</SUP> > K<SUP>+</SUP> > Ca<SUP>2+</SUP> > Mg<SUP>2+</SUP> > H<SUP>+</SUP> and Na<SUP>+</SUP> > K<SUP>+</SUP> > NH4<SUP>+</SUP> > Ca<SUP>2+</SUP> > Mg<SUP>2+</SUP> = H<SUP>+</SUP>, respectively. The anions of all sites were SO4<SUP>2-</SUP> > NO3- > Cl<SUP>-</SUP>. While the amounts of sulfate, one of the major dissolved components of rainwater, were 77.6 and 75.6 ueq L<SUP>-1</SUP> in Suwon and Yeoju, the ones of NSS-SO4<SUP>2-</SUP> (Non-Sea Salt sulfate) were 83 and 82% in Suwon and Yeoju, respectively. The comparison of observed pH values (pHobs) with the theoretical pH values (pHthe) showed that the neutralization of rain water considerably went along during the study periods. The highest amounts of rainfall throughout the year in Suwon and Yeoju were 572.3 and 484.6 mm in July, and its corresponding nitrogen loadings in Suwon and Yeoju were 5.28 and 3.50 kg ha-1, respectively. The major ion contents for crop growth with SO4<SUP>2-</SUP>, Ca<SUP>2+</SUP>, K<SUP>+</SUP> and Mg<SUP>2+</SUP> were 51.7, 5.2, 11.8 and 1.8 kg ha<SUP>-1</SUP> in Suwon and 34.2, 4.0, 4.2 and 1.1 kg ha<SUP>-1</SUP> in Yeoju.

장기저장 미곡의 성분 변화 특성

소규호,김영수,홍재식,정준영,조재민 한국식품영양학회 1999 韓國食品營養學會誌 Vol.12 No.4

미곡의 장기저장에 따른 이화학적 특성의 변화를 조사하여 효율적인 저장방법을 구명하기 위한 기초적 자료를 제공하기 위해 4년간 조곡상태의 미곡 50가마니를 상온 창고에서 저장하면서 성분 변화를 조사하였다. 고내 온도의 변화는 계절에 따라 35℃ 정도였다. 미곡의 수분함량은 저장기간 동안 15% 이상으로 증가한 적이 없어 비교적 안전하였으나 곡온이 18℃이상 유지되는 매년 6월부터 9월까지의 4개월 동안은 고내 습도의 상승과 함께 미질 저하를 일으킬 수 있는 저장 위험 기간이었다. 저장기간 중의 환원당, amylose 함량, 조단백의 변화를 조사한 결과 각각 입고시 0.24%, 19.23%, 7.02%에서 4년간 저장후 각각 0.5%, 20.31%, 7.46%로 증가하는 경향이었다. 저장미의 amylogram 특성을 조사한 결과 저장 기간이 길어짐에 따라 최고 점도, 최종 점도 및 setback은 입고시 각각 449B.U, 610B.U, 161B.U에서 4년 후 493B.U, 715B.U, 222B.U로 높아졌다. 반면에 Breakdown은 입고시 125B.U에서 4년 후 76B.U로 낮아졌다. 저장미의 호화응집성(gel consistency)은 입고시 44.7mm에서 4년후 39.9mm로 감소하였으며 지방산도는 입고시 4.5KOH㎎/100g에서 4년 저장후 각각 24.4KOH㎎/100g로 증가하였다. 배아율과 배아활성은 각각 97%, 100%에서 4년 후 각각 0%, 0.4%로 감소하였다. 한편 미곡에 착생한 미생물상의 변화를 조사한 결과 저장기간이 길어짐에 따라 세균 착생립수는 감소하고 곰팡이의 착생립수는 다소 증가하는 경향이었다. In order to investigate the changes of rice qualities during 4 years storage of paddy stored in warehouse of normal temperature condition. Temperature in warehouse was changed more than 30℃ under the influence of average temperature outside of a warehouse. Water content of paddy was not increased over 15%. But, as average temperature in wasehouse was gone up 18℃ from June to September every years, it was supposed that these periods were to be deterioration of rice quality. On investigation of change in paddy components during the long term storage, reducing sugar, amylose, crude protein were increased 0.24%, 19.23%, 7.02% at enterance time to 0.5%, 20.31%, 7.46% 4 years later, respectively. Max. viscosity, final visocity and set back value by amylograph were increased 449B.U, 610B.U, 161B.U to 493B.U, 715B.U, 222B.U but breakdown was decreased 125B.U to 76B.U with the increase of storage period. Gel consistency of rice stored was decreased 44.7mm at enterance time to 39.9mm 4 years later. Fatty acid was increased remarkably 4.5KOH㎎/100g to 24.4KOH㎎/100g. Germination ratio and germ activity of paddy during long-term storage were decreased 97%, 100% to 0%, 0.4%, respectively. With the increase of storage period, contaminated paddy by molds increased and its by bacteria decreased.

제약업종 부산물 및 화장품 제조업 폐수처리오니의 고추 비해에 미치는 영향

임동규,이상범,권순익,이승환,소규호,성기석,고문환 한국환경농학회 2004 한국환경농학회지 Vol.23 No.4

본 연구는 퇴비의 원료로 지정된 제약업종 부산물(공정오니) 및 화장품 제조업 폐수처리오니를 시용한 후 고추를 재배하면서 시용한 오니에 의한 작물의 비료의 피해를 밝히기 위해 포장에서 작물의 생육과 수량(적과, 청과), 시기별로 토양 및 식물체 중 중금속 함량 등을 조사하였다. 토양 중 유기물 및 질소성분은 시험재료의 성분함량이 높은 처리구에서 생육 초기(6월 11일)에 높았다. 토양의 중금속 성분에서 전함량의 경우 As성분은 생육 중기(7월 8일)에 함량이 급격히 높아졌다가 감소하였으며 Zn·Cu·Pb·Cd성분은 수확기에 갑자기 함량이 증가하였고, 1 N-HCI 가용함량에서 Zn·Cu·Pb·As성분은 생육 중기에 증가하였다가 감소하는 경향이었다. 고추의 생육(초장, 간경)은 초기에는 오니구(제약오니3구 제외)가 화학비료구보다 전반적으로 불량하였는데 이는 유기물 함량이 높은 미 부숙된 오니의 영향인 것으로 생각되며, 생육 후기에는 회복이 되어서 화장품 오니구를 제외하고는 서로 비슷하였다. 고추 식물체(잎, 줄기)의 질소함량에서 생육 초기 및 중기에 제약오니1과 돈분구가 높은 것은 이들 시험재료의 유기물 및 질소성분의 특성과 함량에 기인된 것으로 보이며, 식물체 중 중금속 함량에서 잎은 Zn·Pb·Ni성분이, 줄기는 Zn·Pb성분이 수확기에 급격히 높아졌으므로 이들 성분에 대해서 주의할 필요가 있다고 생각된다. 고추의 총 적과 수량은 가축분뇨 > 제약오니3 > 제약오니1 > 화학비료 > 제약오니2구 순으로 낮아졌으며, 화장품오니구는 타 처리구보다 상당히 감수하였다. 수확기 고차 청과 및 적과의 중금속 함량은 Zn과 Cu성분이 타 성분들보다 높았고, 처리별로는 청과에서 Zn 및 Ni성분은 제약오니1구가, Pb성분은 제약오니3구가 타 처리구들보다 조금 높아서 유기성 오니를 퇴비원료로 사용할 경우 오니 중의 Zn·Cu·Pb·Ni성분의 특성과 함량이 상당히 중요할 것으로 판단된다. 따라서 퇴비원료로 지정된 오니 중에서 화장품오니와 제약오니2에서 생육 후기부터 수확기에 걸쳐 질소성분의 부족 현상에 의한 생육부진과 낙엽, 어떤 원인인지 알 수 없지만 비해에 의한 수량감소 등의 원인을 앞으로 연구를 통해서 밝힐 필요가 있다고 생각된다. 본 시험의 결과는 퇴비원료로 지정하거나, 지정된 퇴비원료의 사용을 신청할 때 허가할 퇴비원료가 작물에 대해 적합한지 알아보는 방법의 일환으로 활용될 수 있을 것이다. Three sludge types from pharmaceutical byproducts and one sludge type from cosmetic waste-water sludge as raw materials of compost were used in a field based concrete pot (4 m², 2m × 2m) for investigating damage of red pepper cultivation. These sludges and pig manure (1 Mg/10a, dry basis) were incorporated into the upper of clay loam soil prior to transplanting with red pepper. Changes in concentration and properties of heavy metal for both of soil and plant were investigated 4 times during of red pepper growth. Plant height and stem diameter of red pepper in sludge treatments except to Pharmaceutical sludge 3 were poor than those of NPK treatment. This result were regarded as an effect of incompleted decomposition sludge which has a lot of organic matter concentration. Amount of total As was increased rapidly Jul. 8. in soil, total Zn·Cu·Pb·Cd were in harvest time, and 1 N-HCl extractable Zn·Cu·Pb·As were rised at middle stage and then decreased. Amounts of nitrogen in plant (leaf and stem) were high in Phamaceutical Sludge 1 and Pig Manure treatment in early and middle stage because of organic matter and nitrogen concentrations and characteristics. Amounts of Zn, Pb, and Ni in leaf and amount of Zn and Pb in stem were increased in harvest time so that we need to have a concern in detail. Total yield of red pepper was Pig Manure > Phamaceutical Sludge 3 > Phamaceutical Sludge 1 > NPK > Phamaceutical Sludge 2 and Cosmetic Sludge treatment was decreased considerably to compare to others. Amounts of Zn and Cu in green and red pepper in harvest time were higher than the other heavy metals. Finally these results can use to utilize that finding damage on crop for authorization and suitability estimation of raw material of compost.

5-Fluorouracil이 흰쥐 肝臟의 燐酸鹽 分解酵素의 活性에 미치는 影響

鄭鎬三,蘇秉造,李圭植 한양대학교 의과대학 1985 한양의대 학술지 Vol.5 No.1

The 5-Fluorouracil (5-FU) has been used as a synthetic antineoplastic agent with the synthesis of nucleic acid in the cell. Unfortunately this drug is known to cause toxic reaction in normal tissue also. In this experiment, the authors studied the effect of 5-FU on the rat liver histochemically observing the change in the activities of acid phosphatase and adenosine triphosphatase. Healthy albino male rats (Wistar strain) were used as experimental animals which were divided into the control and 5-FU treated groups. All experimental animals were given food and water unlimited. The animals of experimental group were administered 5-FU, in a dose of 50mg per kg of body weight by intraperitoneal injection. The animals of control groups were administered only water for injectio. The experimental animals were sacrificed at 6, 12, 24 and 36 hours after administration of 5-FU, respectively. The liver specimens, sectioned by cryostat were stained by Gomori method and by Wachestein and Meisel method for studying changes in the activities of acid phosphatase and that of ATPase, respectively. The results obtained were as follows: 1. The acid phosphatase activity was increased in the hepatic parenchymal cells of the 5-FU treated rat liver. 2. The adenosine triphophatase activity was decreased in the intralobular bile canaliculi of the 5-FU treated rat liver. Consequently, it is suggested that 5-FU would induce the change in the activities of possibly from production of toxic metabolites and subsequent damage in rat liver.

유기성자원의 퇴비원료로 활용 가능성 평가방법 개발

임동규,이승환,성기석,소규호,신중두,이정택 한국환경농학회 2006 한국환경농학회지 Vol.25 No.1

제약업종 부산물 및 화장품 제조업 폐수처리오니 처리토양에 대한 유기화합물 및 Bioassay 분석 평가

임동규,이상범,이승환,남재작,나영은,권장식,권순익,소규호 한국환경농학회 2004 한국환경농학회지 Vol.23 No.4

본 연구는 퇴비원료로 지정된 제약업종 부산물(공정오니) 및 화장품 제조업 폐수처리오니를 퇴비로서 활용 가능성을 판단하기 위하여 기존의 일반성분이나 중금속 성분 분석 이외 유기성 화합물과 기타 여러 생물검정법 등을 활용하여 시용한 오니에 의한 토양 내 비료의 피해를 밝혀내고 이들의 평가방법을 확립하고자 포장시험을 수행하였다. 오니의 처리에 따른 HEM의 함량은 제약업종 오니2(PS2)와 화장품 오니(CS)처리가 각각 0.51, 1.10 mg/kg로 가장 높았고, PAHs의 함량은 제약업종 오니2(PS2) 처리에서 3,406.8 μg/kg로 가장 높았다. 토양에 서식하는 미소동물의 밀도변화는 생육 중기(7월 23일) 및 수확기(10월 1일) 모두 제약오니2 및 돈분 처리구에서 가장 높았으며, 기타 처리구는 차이가 없이 아주 낮았다. 오니의 처리에 따른 세균 및 사상균의 균수는 제약업종 오니2처리에서 각각 736, 909 cfu/g로 가장 많았고, 화장품 오니도 각각 440, 236 cfu/g으로 다른 처리에 비해 많은 경향을 보였다. 제약오니 및 화장품오니 처리시 우점세균은 무비, 돈분처리에 비해 일정한 경향이 없었으나 3요소 처리보다 다양한 세균이 검출되었다. 오니의 처리에 따른 우점사상균은 무처리에 비해 제약업종 오니3와 화장품 오니처리에서 형태적 특징이 다른 콜로니가 검출되었으나 다른 처리는 비슷한 경향으로 종류 간에 큰 차이는 보이지 않았다. Microcosm test를 통하여 오니 처리 후 3개월이 경과한 토양의 오염정도를 평가한 결과는 제약업종 오니3과 화장품 오니처리는 약간 영향을 받아서 80~90% 생존하였으나, 제약업종 오니1처리는 처리 2주(14일) 이후에는 급격히 생존율이 떨어져서 4주 이후에는 10%만 생존하였다. 그러나 6개월이 경과한 토양에서는 지렁이의 생존율은 제약업종 오니1처리만 약간 영향을 받은 것으로 보였으며 다른 처리들은 전혀 영향을 받지 않았던 것으로 조사되었다. 유기성 오니의 퇴비원료로 활용은 비료관리법의 비료공정 규격 중 퇴비의 비고란에 "퇴비의 원료로 사용 가능한 물질과 사용 불가능한 물질'(별표1)에서 "희비의 원료 중 사전 분석검토 후 사용 가능한 원료에 대한 지정요령'에는 유기물과 중금속(8성분) 함량(건물증)과 제조공정 등을 검토하여 지정하고 있으나, 지정된 원료가 과연 회비원료로 적합한지 잘 알 수 없으며 또한 앞으로 현재의 퇴비원료 규정을 변경할 필요가 있을 경우를 대비하여 희비원료의 적합성 여부를 판별할 수 있는 방법의 개발이 필요하다. 따라서 퇴비원료로 이미 지정('02. 12. 31)된 제약오니 및 화장품 오니를 과량으로 토양에 시용한 후 유해 유기화합물, 미소동물, 미생물 및 생물학적(지렁이) 유해성 검정방법의 도입 가능성을 평가하기 위하여 고추를 재배한 포장에서 비료의 피해시험을 실시한 결과 유해 유기화합물과 생물학적(지렁이) 유해성 검정방법은 앞으로 연구를 통해서 보완할 경우 상당히 활용 가능성이 있는 좋은 평가방법인 것으로 생각된다. This study was conducted to assessment organic compound and bioassay (density of inhabited animal, fluctuation of predominant fungi, and survival ratio of earthworm) for finding damage on red pepper by heavily amount application of sludges in soil, which was treated with 3 pharmaceutical byproducts and a cosmetic industry wastewater sludge as raw materials of compost, and for establishing estimation method. HEM contents in the soil treated with pharmaceutical byproducts sludge2 (PS2) and cosmetic sludge (CS) were 0.51, 1.10 mg/kg respectively. PAHs content of PS2 treatment in the soil was 3406.8 ug/kg on July 8. In abundance of soil faunas, the pharmaceutical byproducts sludge2 treatment was the most highest. The next was decreased in the order of pig manure (PM) and the cosmetic sludge treatment. However the other pharmaceutical sludge treatments were remarkably reduced populations of soil inhabited animals. In upland soil treated with organic sludges, the numbers of bacteria and fungi of the pharmaceutical sludge treatment were 736, 909 cfu/g and those of the cosmetic sludge treatment were 440, 236 cfu/g, respectively. The pharmaceutical sludge treatments and the cosmetic sludge treatment in identification of predominant bacteria were not any tendency to compare with non fertilizer and pig manure treatments, but they had diverse bacteria than NPK treatment. In microcosm tests, the survival of the tiger earthworm in five soil samples was hardly affected against the soil of PSI (20%) after three months treated in the upland. But after six months, survival of PSI was 80%. At present, raw material of compost was authorized by contents of organic matter, heavy metal (8 elements), and product processing according to "The specified gist on possible materials of using after analysis and investigation among raw materials of compost", however, for preparing to change regulation of raw material of compost and for considering to possibility of application, this study was conducted to investigate toxic organic compound and bioassay methods using inhabited animal, fungi, and earthworm without current regulation.

복합레진의 exponential 중합법이 상아질접착제의 미세인장접착강도에 미치는 영향

성소래,서덕규,이인복,손호현,조병훈 大韓齒科保存學會 2010 Restorative Dentistry & Endodontics Vol.35 No.2

접착제를 통해 치아에 접착되는 상부의 복합레진의 빠른 중합은 접착제층에 높은 중합수축응력을 발생시킨다. 중합수축응력을 경감시키기 위해서, LED 광중합기의 하나인 Elipar FreeLight 2 (3M ESPE, USA)에서는 최초 5초 이내에 광강도를 증가시키는 exponential 중합법을 채택하고 있다. 본 연구에서는 짧은 시간내에 광강도를 증가시키는 exponential 중합법이 복합레진의 초기 중합수축속도를 효과적으로 조절할 수 있는지를 알아보기 위해 접착제 적용 후 상부의 복합레진을 exponential 중합법과 continuous 중합법으로 중합하여 상아질접착제의 미세인장접착강도를 비교하였다. 3M사의 Scotchbond Multipurpose Plus (MP), Single Bond 2 (SB), 및 Adper Prompt (AP)의 세 종류의 접착제를 발치한 대구치의 교합면 상아질에 제조사의 지시에 따라 적용하고, 혼합형 복합레진인 Denfil (Vericom, Korea)을 두 가지 광중합방법으로 중합하였다. 접착 후 48시간에 미세인장접착강도를 측정하고, 파절면은 FE-SEM.으로 관찰하였다. 그 결과, 각각의 접착제에서 중합방법에 따른 접착강도의 차이는 관찰할 수 없었다(Two-way ANOVA, p > 0.05). MP와 SB의 미세인장접착강도는 AP에 비해 유의하게 높았다(p < 0.05). 대부분의 파절시편에서는 혼합형 파절이 가장 많이 관찰되었으나, 중합방법에 따른 파절양상의 차이는 없었다. 결론적으로 5초 이내의 짧은 시간에 광강도를 증가시키는 exponential 중합법은 continuous 중합법과 비교하여 상아질접착제의 미세인장접착강도에 영향을 주지 않았다. Objectives: Rapid polymerization of overlying composite resin causes high polymerization shrinkage stress at the adhesive layer. In order to alleviate the shrinkage stress, increasing the light intensity over the first 5 seconds was suggested as an exponential curing mode by an LED light curing unit (Elipar FreeLight2, 3M ESPE). In this study, the effectiveness of the exponential curing mode on reducing stress was evaluated with measuring microtensile bond strength of three adhesives after the overlying composite resin was polymerized with either continuous or exponential curing mode. Methods: Scotchbond Multipurpose Plus (MP, 3M ESPE), Single Bond 2 (SB, 3M ESPE), and Adper Prompt (AP, 3M ESPE) were applied onto the flat occlusal dentin of extracted human molar. The overlying hybrid composite (Denfil, Vericom, Korea) was cured under one of two exposing modes of the curing unit. At 48h from bonding, microtensile bond strength was measured at a crosshead speed of 1.0 mm/min. The fractured surfaces were observed under FE-SEM. Results: There was no statistically significant difference in the microtensile bond strengths of each adhesive between curing methods (Two-way ANOVA, p > 0.05). The microtensile bond strengths of MP and SB were significantly higher than that of AP (p < 0.05). Mixed failures were observed in most of the fractured surfaces, and differences in the failure mode were not observed among groups. Conclusion: The exponential curing method had no beneficial effect on the microtensile dentin bond strengths of three adhesives compared to continuous curing method.

응축형 복합레진의 파괴거동에 관한 연구

김소영,최호영,최경규,박상진 대한치과보존학회 2000 Restorative Dentistry & Endodontics Vol.25 No.3

In this study, compressive strengths of three condensable composite resins(ALERT, SureFil. Solitaire), conventional hybrid composite resin(Z-100) and amalgam(HI-Aristaloy 21) according to the 6 types of cavity design(cylinder, trapezoidal, butt-joint, round bevel, long bevel and short bevel) were measured and appearance of fracture surfaces were observed with SEM, thus evaluated clinical applications of condensable composite resins according to the cavity designs. The results were as follows: 1.Compressive strengths according to experimental materials were the highest in SureFil, and Z-100, ALERT, Solitaire, Hl-Aristaloy 21 in order. 2.SureFil showed the highest compressive strength(p〈0.05) , compressive strengths of ALERT and Solitaire were lower than that of Z-100, hybrid composite(p〈0.05) . 3.Compressive strengths according to specimen design were the highest in trapezoidal shape(p〈0.05) and no significant difffrence was detected between other specimen designs. 4.The appearance of condensable composite resin under SEM was of a diverse configuration according to component of resin matrix, shapes of filler and surface treatments between resin and filler.

체중이동 과제 학습시 효과적인 운동학적 되먹임 유형과 상대적 빈도

차승규,박소연,정진호,김영호 한국전문물리치료학회 2000 한국전문물리치료학회지 Vol.7 No.1

Physical therapists have been using balance and weight shifting training to induce improvements in standing and walking. This study compared the effects of kinetic feedback frequency and concurrent kinetic feedback on the performance and learning of a weight shifting skill in young, nondisabled adults. Sixteen young adults without known impairment of the neuromusculoskeletal system volunteered for the study. Subjects in each of three kinetic feedback groups performed a weight shifting task in an attempt to minimize error between their effort and a center of pressure (COP) template for a 12 second period. Feedback was provided: 1) concurrently (concurrent feedback), 2) after each trial (100% feedback), 3) after ever other trial (50% feedback). Immediate and delayed (24 hous) retention tests were performed without feedback. During ascquistion phase, the concurrent feedback group exhibited less error than either of the post response feedback group. For the immediate retention test, the 50% feedback group exhibited less error than did the 100% feedback and concurrent feedback. During the delayed retention, 50% feedback group displayed less error than did the other groups. But no significant differences were found between groups. these results suggest that practice with concurrent feedback is beneficial for the immediate performance, but not for the learning of this weight shifting skill. Lower frequency of feedback resulted in more permanent changes in the subject's ability to complete the task.