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Won SY, Han GP, Kwon CH, Lee EC, Kil DY. Effect of individual or combination of dietary betaine and glycine on productive performance, stress response, liver health, and intestinal barrier function in broiler chickens raised under heat stress conditions. Poult Sci 2023; 102:102771. [PMID: 37236038 DOI: 10.1016/j.psj.2023.102771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Revised: 04/20/2023] [Accepted: 04/29/2023] [Indexed: 05/28/2023] Open
Abstract
The current experiment was conducted to investigate the effect of individual or combination of dietary betaine (Bet) and glycine (Gly) on productive performance, stress response, liver health, and intestinal barrier function in broiler chickens raised under heat stress (HS) conditions. A total of four hundred twenty 21-d-old Ross 308 broiler chickens were randomly allotted to 1 of 5 dietary treatments with 7 replicates. Birds in treatment 1 were raised under the thermoneutral condition (TN; 23 ± 0.6°C). Birds in other 4 treatment groups were subjected to a cyclic HS by exposing them to 32 ± 0.9°C for 8 h/d (from 09:00 to 17:00 h) and 28 ± 1.2°C for the remaining time for 14 d. Birds were fed a basal diet in TN condition (TN-C) and one group in HS conditions (HS-C), whereas other birds raised under HS conditions were fed the basal diet supplemented with 0.20% Bet (HS-Bet), 0.79% Gly (HS-Gly), or their combination (0.20% Bet + 0.79% Gly; HS-Bet+Gly). Results indicated that birds in HS-Bet, HS-Gly, or HS-Bet+Gly treatment had higher (P < 0.05) final BW and BW gain, but lower (P < 0.05) feed conversion ratio (FCR) than those in HS-C treatment. However, values for improved final BW, BW gain, and FCR by dietary treatments were lower (P < 0.05) than those measured in TN-C treatment. Under HS conditions, birds in HS-Bet, HS-Gly, or HS-Bet+Gly treatment had lower (P < 0.05) heterophil to lymphocyte ratio than those in HS-C treatment. Birds in HS-Gly or HS-Bet+Gly treatment had higher (P < 0.05) villus height and goblet cell number than birds in HS-C treatment. Intestinal permeability was higher (P < 0.05) in all HS-treatment groups than in TN-C treatment, but it was not affected by dietary treatment. In conclusion, individual supplementation of 0.20% Bet or 0.79% Gly in diets alleviates the negative effect of HS in broiler chickens. However, the synergistic effect of the combination of 0.20% Bet and 0.79% Gly in broiler diets seems lower than expected.
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Affiliation(s)
- Seung Yeon Won
- Department of Animal Science and Technology, Chung-Ang University, Anseong-si, Gyeonggi-do 17546, Republic of Korea
| | - Gi Ppeum Han
- Department of Animal Science and Technology, Chung-Ang University, Anseong-si, Gyeonggi-do 17546, Republic of Korea
| | - Chan Ho Kwon
- Department of Animal Science and Technology, Chung-Ang University, Anseong-si, Gyeonggi-do 17546, Republic of Korea
| | - Eun Cheol Lee
- Department of Animal Science and Technology, Chung-Ang University, Anseong-si, Gyeonggi-do 17546, Republic of Korea
| | - Dong Yong Kil
- Department of Animal Science and Technology, Chung-Ang University, Anseong-si, Gyeonggi-do 17546, Republic of Korea.
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Lee EC, Park J. Unraveling the Structural Instability of Li(Ni 0.80 Co 0.15 Al 0.05 )O 2 as a Cathode Material Due to Operating a Li-ion Battery. Small 2022; 18:e2200581. [PMID: 35607753 DOI: 10.1002/smll.202200581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 03/17/2022] [Indexed: 06/15/2023]
Abstract
The change of the crystal structure for Li(Ni0.80 Co0.15 Al0.05 )O2 as a cathode material in a Li-ion battery is traced. During charging and discharging, the crystallographic change of Lix (Ni0.80 Co0.15 Al0.05 )O2 (x ≈ 1.0-0.25) is confirmed with in situ X-ray diffraction, an electrochemical measurement, and the density functional theory calculation. Li atoms after cycling do not completely return to the initial state and defects in the Li-layer generate about 5%. The effect of defects in the Li-layer reveals the transformation of crystal structure and the change of lattice constants. Upon increasing the temperature, the instability of Li0.95 (Ni0.80 Co0.15 Al0.05 )O2 is clearly shown as the movement of transition metals using X-ray and neutron diffraction. The crystallographic values dramatically change upon increasing from 373 to 423 K, but linearly vary upon decreasing temperature. Furthermore, the result of the calculation demonstrates that the possible atom for mixing is Ni. The evolution of magnetic properties explicitly certifies the atomic movement that gives rise to a spin-glass state through the induction of ferromagnetism. In conclusion, defects are created in crystal structure during operation of the Li-ion battery and generate structural instability. The results provide the cause and mechanism of the degradation of cathode material in a Li-ion battery.
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Affiliation(s)
- Eun Cheol Lee
- R&D Center, Samsung SDI Co. Ltd., 130, Samsung-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do, 16678, Republic of Korea
| | - Junghwan Park
- R&D Center, Samsung SDI Co. Ltd., 130, Samsung-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do, 16678, Republic of Korea
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Vingren JL, Boyett JC, Lee EC, Levitt DE, Luk HY, McDermott BP, Munoz CX, Ganio MS, Armstrong LE, Hill DW. A Single Dose of Ibuprofen Impacts IL-10 Response to 164-km Road Cycling in the Heat. Res Q Exerc Sport 2022:1-7. [PMID: 35344476 DOI: 10.1080/02701367.2021.1981539] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 09/08/2021] [Indexed: 06/14/2023]
Abstract
Purpose: The purpose was to determine the effect of a single-dose prophylactic ibuprofen use before a 164-km road cycling event in high ambient temperature on the circulating cytokine and leukocyte responses. Methods: Twenty-three men (53 ± 8 y, 172.0 ± 22.0 cm, 85.1 ± 12.8 kg, 19.6 ± 4.4% body fat) completed a 164-km self-paced recreational road cycling event in a hot, humid, sunny environment (WBGT = 29.0 ± 2.9°C) after consuming 600 mg of ibuprofen (n = 13) or a placebo (n = 10). Blood samples were obtained one to two hours before (PRE) and immediately after (POST) the event, and analyzed for concentrations of circulating cytokines interleukins (IL)-1β, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12, IL-13, GM-CSF, IFN-γ, and TNF-α and leukocytes (total leukocytes, granulocytes, monocytes, and lymphocytes). Results: Event completion time was 400.2 ± 74.8 min. Concentrations of all cytokines (except IL-1β, IL-2, IL-5, IL-12, GM-CSF, and IFN-γ) and of all leukocyte subsets increased from PRE to POST. Ibuprofen ingestion attenuated the increase in IL-10 (86% increase with Ibuprofen; 270% increase with placebo). Conclusions: Consuming 600 mg of Ibuprofen prior to a 164-km road cycling event in a hot-humid environment attenuates exercise-induced increases in the concentration of the anti-inflammatory cytokine IL-10, but does not alter the effect of the exercise event on concentrations of other circulating cytokines or leukocyte subset concentrations.
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Affiliation(s)
| | | | | | | | - H Y Luk
- University of North Texas
- Texas Tech University
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Sharp SP, Ata A, Chismark AD, Canete JJ, Valerian BT, Wexner SD, Lee EC. Racial disparities after stoma construction in colorectal surgery. Colorectal Dis 2020; 22:713-722. [PMID: 31876362 DOI: 10.1111/codi.14943] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 11/29/2019] [Indexed: 12/12/2022]
Abstract
AIM Racial disparities are under-recognized among patients undergoing colorectal surgery. The purpose of this study was to determine the complication rates and surgical outcomes stratified by race and ethnicity among patients undergoing colorectal surgery with intestinal stoma creation. METHOD The ACS NSQIP database from 2013 to 2016 was used. Colon, rectum and small bowel cases requiring intestinal stoma creation were selected. Both African-American and other groups of minority patients were compared with Caucasian patients using a complex multivariable analysis model. Primary outcomes of interest were complication rates, mortality and extended hospital length of stay. RESULTS The study included 38 088 admissions. After multivariable analysis, African-American patients still had a prolonged length of hospital stay and higher complication rates. Other minorities also had a prolonged length of hospital stay and higher complication rates. CONCLUSIONS Both African-American and other groups of minority patients requiring an ostomy suffer significantly higher postoperative complication rates and a prolonged hospital length of stay, even after comorbidity adjustment. Access to care, socioeconomic status and comorbid disease management are all important factors for minority patients who undergo colorectal surgery requiring intestinal stoma construction.
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Affiliation(s)
- S P Sharp
- Division of Colon and Rectal Surgery, Albany Medical Center, Albany, New York, USA.,Digestive Disease Center, Department of Colorectal Surgery, Cleveland Clinic Florida, Weston, Florida, USA
| | - A Ata
- Division of Colon and Rectal Surgery, Albany Medical Center, Albany, New York, USA
| | - A D Chismark
- Division of Colon and Rectal Surgery, Albany Medical Center, Albany, New York, USA
| | - J J Canete
- Division of Colon and Rectal Surgery, Albany Medical Center, Albany, New York, USA
| | - B T Valerian
- Division of Colon and Rectal Surgery, Albany Medical Center, Albany, New York, USA
| | - S D Wexner
- Digestive Disease Center, Department of Colorectal Surgery, Cleveland Clinic Florida, Weston, Florida, USA
| | - E C Lee
- Division of Colon and Rectal Surgery, Albany Medical Center, Albany, New York, USA
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Yoo HS, Lee EC, Chung SJ, Lee YH, Lee SG, Yun M, Lee PH, Sohn YH, Seong JK, Ye BS. Effects of Alzheimer's disease and Lewy body disease on subcortical atrophy. Eur J Neurol 2019; 27:318-326. [PMID: 31487756 DOI: 10.1111/ene.14080] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 08/21/2019] [Indexed: 11/30/2022]
Abstract
BACKGROUND AND PURPOSE Subcortical structures are affected by neurodegeneration in Alzheimer's disease (AD) and Lewy body disease (LBD). Although the co-occurrence of AD and LBD pathologies and their possible interaction have been reported, the effect of AD and LBD on subcortical structures remains unknown. The effects of AD and LBD on subcortical atrophy and their relationship with cognitive dysfunction were investigated. METHODS The cross-sectional study recruited 42 patients with pure AD related cognitive impairment (ADCI), 30 patients with pure LBD related cognitive impairment (LBCI), 58 patients with mixed ADCI and LBCI, and 29 normal subjects. A general linear model was used to compare subcortical volume and shape amongst the groups, to investigate the independent and interaction effects of ADCI and LBCI on subcortical shape and volume, and to analyze the relationship between subcortical volume and cognitive dysfunction in each group. RESULTS Alzheimer's disease related cognitive impairment and LBCI were independently associated with subcortical atrophies in the hippocampus and amygdala and in the hippocampus and putamen respectively, but their interaction effect was not significant. Compared to the control group, the pure LBCI group exhibited additional local atrophies in the amygdala, caudate and thalamus. Subcortical atrophies correlated differently with cognitive dysfunction according to the underlying causes of cognitive dysfunction. CONCLUSIONS The patterns of subcortical atrophies and their correlation with cognitive dysfunction differ according to the underlying AD, LBD or concomitant AD and LBD.
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Affiliation(s)
- H S Yoo
- Department of Neurology, Yonsei University College of Medicine, Seoul, South Korea
| | - E C Lee
- Department of Bio-convergence Engineering, Korea University, Seoul, South Korea
| | - S J Chung
- Department of Neurology, Yonsei University College of Medicine, Seoul, South Korea
| | - Y H Lee
- Department of Neurology, Yonsei University College of Medicine, Seoul, South Korea
| | - S G Lee
- Department of Radiology, Yonsei University College of Medicine, Seoul, South Korea
| | - M Yun
- Department of Nuclear Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - P H Lee
- Department of Neurology, Yonsei University College of Medicine, Seoul, South Korea
| | - Y H Sohn
- Department of Neurology, Yonsei University College of Medicine, Seoul, South Korea
| | - J-K Seong
- Department of Bio-convergence Engineering, Korea University, Seoul, South Korea.,School of Biomedical Engineering, Korea University, Seoul, South Korea
| | - B S Ye
- Department of Neurology, Yonsei University College of Medicine, Seoul, South Korea
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Affiliation(s)
- Hyun Jun Jang
- Department of Medical Biotechnology (BK21 Plus team), Dongguk University Biomedi Campus, Gyeonggi-do, Korea
| | - Eun Cheol Lee
- Department of Medical Biotechnology (BK21 Plus team), Dongguk University Biomedi Campus, Gyeonggi-do, Korea
| | | | - Young Kwon Seo
- Department of Medical Biotechnology (BK21 Plus team), Dongguk University Biomedi Campus, Gyeonggi-do, Korea
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Kim SH, Lee EC, Park SJ. Living-donor Liver Retransplantation Using the Vessels of the Previous Allograft by Means of Intragraft Dissection. Transplant Proc 2018; 50:3562-3563. [PMID: 30577238 DOI: 10.1016/j.transproceed.2018.09.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 08/27/2018] [Accepted: 09/11/2018] [Indexed: 11/16/2022]
Abstract
Retransplantation with the use of a living-donor graft can be the only therapeutic option for patients with irreversible graft failure, especially in regions with limited access to deceased donors, but it can be technically demanding because of severe adhesion around the hepatic hilum and inferior vena cava. We introduce an effective and safe technique to overcome this challenge for right-lobe living-donor liver retransplantation by using the vessels of the previous right liver allograft with the use of intragraft dissection. The technique was used in 2 critically ill patients undergoing the graft failure. The operative times were 360 and 410 minutes. The recipients were discharged on days 18 and 25 with normal liver function. One postoperative complication occurred 3 months after retransplantation: biliary leakage, corrected with the use of percutaneous transhepatic biliary drainage. Both patients were alive with a functioning allograft at last follow-up of >3 years. Intragraft dissection to use the vessels of the previous right-liver allograft can be a useful technique and should be considered for right-lobe living-donor liver retransplantation.
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Affiliation(s)
- S H Kim
- National Cancer Center, Goyang-si, Gyeonggi-do, Korea.
| | - E C Lee
- National Cancer Center, Goyang-si, Gyeonggi-do, Korea
| | - S J Park
- National Cancer Center, Goyang-si, Gyeonggi-do, Korea
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Park HM, Han SS, Lee EC, Lee SD, Yoon HM, Eom BW, Kim SH, Ryu KW, Park SJ, Kim YW, Park B. Randomized clinical trial of preoperative skin antisepsis with chlorhexidine gluconate or povidone–iodine. Br J Surg 2016; 104:e145-e150. [DOI: 10.1002/bjs.10395] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Revised: 07/04/2016] [Accepted: 09/06/2016] [Indexed: 11/11/2022]
Abstract
Abstract
Background
Skin antiseptic agents are used to prevent surgical-site infection (SSI); few trials have reported the superiority of any specific agent in clean-contaminated abdominal surgery. This RCT was designed to compare the effectiveness of chlorhexidine gluconate and povidone–iodine.
Methods
Consecutive patients who underwent clean-contaminated upper gastrointestinal or hepatobiliary–pancreatic open surgery between 2011 and 2014 were assigned randomly to either chlorhexidine gluconate or povidone–iodine. The primary endpoint was the occurrence of SSI within 30 days of surgery. Secondary endpoints included causative organisms and risk factors for SSI.
Results
A total of 534 patients were randomized; 31 (5·8 per cent) developed an SSI. There was no difference in the overall SSI rate in the chlorhexidine gluconate and povidone–iodine groups: 15 of 267 (5·6 per cent) and 16 of 267 (6·0 per cent) respectively (P = 0·853). The most common causative organism was Enterococcus faecalis. In subgroup analysis, biliary–pancreatic surgery had a higher SSI rate (26 of 127, 20·5 per cent) than upper gastrointestinal (2 of 204, 1·0 per cent) and hepatic (3 of 203, 1·5 per cent) resection. Both age (60 years and over) and type of incision were associated with the risk of SSI.
Conclusion
No difference was detected between chlorhexidine gluconate and povidone–iodine antiseptics for prevention of SSI. Registration number: NCT01495117 (http://www.clinicaltrials.gov).
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Affiliation(s)
- H M Park
- Centre for Liver Cancer, National Cancer Centre, South Korea
| | - S-S Han
- Centre for Liver Cancer, National Cancer Centre, South Korea
| | - E C Lee
- Centre for Liver Cancer, National Cancer Centre, South Korea
| | - S D Lee
- Centre for Liver Cancer, National Cancer Centre, South Korea
| | - H M Yoon
- Centre for Gastric Cancer, National Cancer Centre, South Korea
| | - B W Eom
- Centre for Gastric Cancer, National Cancer Centre, South Korea
| | - S H Kim
- Centre for Liver Cancer, National Cancer Centre, South Korea
| | - K W Ryu
- Centre for Gastric Cancer, National Cancer Centre, South Korea
| | - S-J Park
- Centre for Liver Cancer, National Cancer Centre, South Korea
| | - Y W Kim
- Centre for Gastric Cancer, National Cancer Centre, South Korea
| | - B Park
- Biometric Research Branch, Research Institute and Hospital, National Cancer Centre, South Korea
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Park S, Won MJ, Mun S, Lee EC, Whang M. Does visual fatigue from 3D displays affect autonomic regulation and heart rhythm? Int J Psychophysiol 2014; 92:S0167-8760(14)00056-7. [PMID: 24534823 DOI: 10.1016/j.ijpsycho.2014.02.003] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Revised: 02/03/2014] [Accepted: 02/09/2014] [Indexed: 11/16/2022]
Abstract
Most investigations into the negative effects of viewing stereoscopic 3D content on human health have addressed 3D visual fatigue and visually induced motion sickness (VIMS). Very few, however, have looked into changes in autonomic balance and heart rhythm, which are homeostatic factors that ought to be taken into consideration when assessing the overall impact of 3D video viewing on human health. In this study, 30 participants were randomly assigned to two groups: one group watching a 2D video, (2D-group) and the other watching a 3D video (3D-group). The subjects in the 3D-group showed significantly increased heart rates (HR), indicating arousal, and an increased VLF/HF (Very Low Frequency/High Frequency) ratio (a measure of autonomic balance), compared to those in the 2D-group, indicating that autonomic balance was not stable in the 3D-group. Additionally, a more disordered heart rhythm pattern and increasing heart rate (as determined by the R-peak to R-peak (RR) interval) was observed among subjects in the 3D-group compared to subjects in the 2D-group, further indicating that 3D viewing induces lasting activation of the sympathetic nervous system and interrupts autonomic balance.
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Affiliation(s)
- S Park
- Dept. of Emotion Engineering, Graduate School, Sangmyung University, 7 Hongji-dong, Jongro-Ku, Seoul 110-743, Republic of Korea.
| | - M J Won
- Dept. of Emotion Engineering, Graduate School, Sangmyung University, 7 Hongji-dong, Jongro-Ku, Seoul 110-743, Republic of Korea.
| | - S Mun
- Dept. of Human Computer Interaction and Robotics, University of Science and Technology, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791, Republic of Korea.
| | - E C Lee
- Dept. of Computer Science, Sangmyung University, 7 Hongji-dong, Jongro-Ku, Seoul 110-743, Republic of Korea.
| | - M Whang
- Dept. of Digital Media, Sangmyung University, 7 Hongji-dong, Jongro-Ku, Seoul 110-743, Republic of Korea.
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Abstract
PURPOSE Single-incision laparoscopic surgery is gaining momentum in general surgery but it is essentially unstudied for laparoscopic colectomy. The aim of our study was to compare outcomes for single-incision laparoscopic colectomy with laparoscopic-assisted colectomy. METHODS Patients undergoing laparoscopic colectomy were prospectively entered into an institutional review board-approved database. Those that underwent single-incision laparoscopic colectomy were case matched for sex, age, disease, surgery, body mass index, previous surgeries, and surgeon with patients undergoing LAC. RESULTS Twenty-nine single-incision laparoscopic segmental colectomies were performed for polyps (4), adenocarcinoma (12), diverticulitis (6), and Crohn's disease (7) and were case matched to laparoscopic-assisted colectomy for the same indications. Mean body mass index was 28.8 ± 3 kg/m². Operative time was longer for single-incision laparoscopic colectomy (134.4 ± 40 vs 103.8 ± 54 min; P = .0002). Four single-incision laparoscopic colectomies were converted to LAC requiring either one extra port (2) or 2 extra ports (2), and there was one conversion to laparotomy. Extraction scar length (millimeters) was similar (38 ± 6.0 vs 45 ± 6.2; P = .746). Postoperative morbidity (5/29 vs 7/29; P = .284) and length of stay (day) (3.7 ± 1.1 vs 3.9 ± 1.1; P = .445) were similar between groups. CONCLUSIONS Single-incision laparoscopic colectomy is feasible and safe but takes more time than laparoscopic-assisted colectomy. Although results approximate those for laparoscopic-assisted colectomy, an additional learning curve is involved, and extra incisions are sometimes required. Single-incision laparoscopic colectomy requires further prospective validation so that the cost of the device can be justified by an improved clinical outcome.
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Affiliation(s)
- B J Champagne
- Division of Colorectal Surgery, University Hospitals Case Medical Center, 11100 Euclid Avenue, Cleveland, OH 44106-5047, USA.
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Min SK, Park M, Singh NJ, Lee HM, Lee EC, Kim KS, Lagutschenkov A, Niedner-Schatteburg G. Chiral transformation in protonated and deprotonated adipic acids through multistep internal proton transfer. Chemistry 2010; 16:10373-9. [PMID: 20652911 DOI: 10.1002/chem.200903355] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Protonated and deprotonated adipic acids (PAA: HOOC-(CH(2))(4)--COOH(2) (+) and DAA: HOOC-(CH(2))(4)-COO(-)) have a charged hydrogen bond under the influence of steric constraint due to the molecular skeleton of a circular ring. Despite the similarity between PAA and DAA, it is surprising that the lowest energy structure of PAA is predicted to have (H(2)O...H...OH(2))(+) Zundel-like symmetric hydrogen bonding, whereas that of DAA has H(3)O(+) Eigen-like asymmetric hydrogen bonding. The energy profiles show that direct proton transfer between mirror image structures is unfavorable. Instead, the chiral transformation is possible by subsequent backbone twistings through stepwise proton transfer along multistep intermediate structures, which are Zundel-like ions for PAA and Eigen-like ions for DAA. This type of chiral transformation by multistep intramolecular proton transfers is unprecedented. Several prominent OH...O short hydrogen-bond stretching peaks are predicted in the range of 1000-1700 cm(-1) in the Car-Parrinello molecular dynamics (CPMD) simulations, which show distinctive signatures different from ordinary hydrogen-bond peaks. The O-H-O stretching peaks in the range of 1800-2700 cm(-1) become insignificant above around 150 K and are almost washed out at about 300 K.
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Affiliation(s)
- Seung Kyu Min
- Center for Superfunctional Materials, Department of Chemistry, Pohang University of Science and Technology, San 31, Hyojadong, Namgu, 790-784 Pohang, South Korea
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Affiliation(s)
- Inacrist Geronimo
- Center for Superfunctional Materials, Department of Chemistry, Pohang University of Science and Technology, Pohang, 790-784, Korea
| | - Eun Cheol Lee
- Center for Superfunctional Materials, Department of Chemistry, Pohang University of Science and Technology, Pohang, 790-784, Korea
| | - N. Jiten Singh
- Center for Superfunctional Materials, Department of Chemistry, Pohang University of Science and Technology, Pohang, 790-784, Korea
| | - Kwang S. Kim
- Center for Superfunctional Materials, Department of Chemistry, Pohang University of Science and Technology, Pohang, 790-784, Korea
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Lee HM, Kumar A, Kołaski M, Kim DY, Lee EC, Min SK, Park M, Choi YC, Kim KS. Comparison of cationic, anionic and neutral hydrogen bonded dimers. Phys Chem Chem Phys 2010; 12:6278-87. [PMID: 20405079 DOI: 10.1039/b925551f] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Short Strong Hydrogen Bonds (SSHBs) play an important role in many fields of physics, chemistry and biology. Since it is known that SSHBs exist in many biological systems, the role of hydrogen bonding motifs has been particularly interesting in enzyme catalysis, bio-metabolism, protein folding and proton transport phenomena. To explore the characteristic features of neutral, anionic and cationic hydrogen bonds, we have carried out theoretical studies of diverse homogeneous and heterogeneous hydrogen bonded dimers including water, peroxides, alcohols, ethers, aldehydes, ketones, carboxylic acids, anhydrides, and nitriles. Geometry optimization and harmonic frequency calculations are performed at the levels of Density Functional Theory (DFT) and Møller-Plesset second order perturbation (MP2) theory. First principles Car-Parrinello molecular dynamics (CPMD) simulations are performed to obtain IR spectra derived from velocity- and dipole-autocorrelation functions. We find that the hydrogen bond energy is roughly inversely proportional to the fourth power of the r(O/N-H) distance. Namely, the polarization of the proton accepting O/N atom by the proton-donating H atom reflects most of the binding energy in these diverse cation/anion/neutral hydrogen bonds. The present study gives deeper insight into the nature of hydrogen-bonded dimers including SSHBs.
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Affiliation(s)
- Han Myoung Lee
- Center for Superfunctional Materials, Department of Chemistry, Pohang University of Science and Technology, San 31, Hyojadong, Namgu, 790-784 Pohang, South Korea
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Min SK, Lee EC, Lee HM, Kim DY, Kim D, Kim KS. Complete basis set limit ofAb initio binding energies and geometrical parameters for various typical types of complexes. J Comput Chem 2008; 29:1208-21. [DOI: 10.1002/jcc.20880] [Citation(s) in RCA: 140] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Singh NJ, Lee EC, Choi YC, Lee HM, Kim KS. Understanding Clusters toward the Design of Functional Molecules and Nanomaterials. BCSJ 2007. [DOI: 10.1246/bcsj.80.1437] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Abstract
Cation-pi and the corresponding anion-pi interactions have in general been investigated as binary complexes despite their association with counterions. However, a recent study of the ammonia channel highlights the important but overlooked role of anions in cation-pi interactions. In an effort to examine the structural and energetic consequences of the presence of counterions, we have carried out detailed ab initio calculations on some model cation-pi-anion ternary complexes and evaluated the nonpair potential terms, three-body contributions, and attractive and repulsive energy components of the interaction energy. The presence of the anion in the vicinity of the pi system leads to a large redistribution of electron density and hence leads to an inductive stabilization. The resulting electronic and geometrical changes have important consequences in both chemical and biological systems. Compared to cation-pi-anion ternary complexes, the magnitude of the cation-pi interaction in pi-cation-anion ternary complexes is markedly lower because of charge transfer from the anion to the cation.
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Affiliation(s)
- Dongwook Kim
- Center for Superfunctional Materials, Department of Chemistry, Pohang University of Science and Technology, San 31, Hyojadong, Pohang 790-784, Korea
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18
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Lee EC, Kim D, Jurecka P, Tarakeshwar P, Hobza P, Kim KS. Understanding of Assembly Phenomena by Aromatic−Aromatic Interactions: Benzene Dimer and the Substituted Systems. J Phys Chem A 2007; 111:3446-57. [PMID: 17429954 DOI: 10.1021/jp068635t] [Citation(s) in RCA: 580] [Impact Index Per Article: 34.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Interactions involving aromatic rings are important in molecular/biomolecular assembly and engineering. As a consequence, there have been a number of investigations on dimers involving benzene or other substituted pi systems. In this Feature Article, we examine the relevance of the magnitudes of their attractive and repulsive interaction energy components in governing the geometries of several pi-pi systems. The geometries and the associated binding energies were evaluated at the complete basis set (CBS) limit of coupled cluster theory with singles, doubles, and perturbative triples excitations [CCSD(T)] using a least biased scheme for the given data set. The results for the benzene dimer indicate that the floppy T-shaped structure (center-to-center distance: 4.96 A, with an axial benzene off-centered above the facial benzene) is isoenergetic in zero-point-energy (ZPE) corrected binding energy (D0) to the displaced-stacked structure (vertical interplanar distance: 3.54 A). However, the T-shaped structure is likely to be slightly more stable (D0 approximately equal to 2.4-2.5 kcal/mol) if quadruple excitations are included in the coupled cluster calculations. The presence of substituents on the aromatic ring, irrespective of their electron withdrawing or donating nature, leads to an increase in the binding energy, and the displaced-stacked conformations are more stabilized than the T-shaped conformers. This explains the wide prevalence of displaced stacked structures in organic crystals. Despite that the dispersion energy is dominating, the substituent as well as the conformational effects are correlated to the electrostatic interaction. This electrostatic origin implies that the substituent effect would be reduced in polar solution, but important in apolar media, in particular, for assembling processes.
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Affiliation(s)
- Eun Cheol Lee
- Center for Superfunctional Materials, Department of Chemistry, Pohang University of Science and Technology, San 31, Hyojadong, Namgu, Pohang 790-784, Korea
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19
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Lim H, Mujat M, Kerbage C, Lee EC, Chen Y, Chen TC, de Boer JF. High-speed imaging of human retina in vivo with swept-source optical coherence tomography. Opt Express 2006; 14:12902-8. [PMID: 19532183 DOI: 10.1364/oe.14.012902] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We present the first demonstration of human retinal imaging in vivo using optical frequency domain imaging (OFDI) in the 800-nm range. With 460-muW incident power on the eye, the sensitivity is 91 dB at maximum and >85 dB over 2-mm depth range. The axial resolution is 13 mum in air. We acquired images of retina at 43,200 depth profiles per second and a continuous acquisition speed of 84 frames/s (512 A-lines per frame) could be maintained over more than 2 seconds.
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20
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Abstract
The two dimensional (2D) to three dimensional (3D) transition for the protonated water cluster has been controversial, in particular, for H(+)(H(2)O)(7). For H(+)(H(2)O)(7) the 3D structure is predicted to be lower in energy than the 2D structure at most levels of theory without zero-point energy (ZPE) correction. On the other hand, with ZPE correction it is predicted to be either 2D or 3D depending on the calculational levels. Although the ZPE correction favors the 3D structure at the level of coupled cluster theory with singles, doubles, and perturbative triples excitations [CCSD(T)] using the aug-cc-pVDZ basis set, the result based on the anharmonic zero-point vibrational energy correction favors the 2D structure. Therefore, the authors investigated the energies based on the complete basis set limit scheme (which we devised in an unbiased way) at the resolution of the identity approximation Moller-Plesset second order perturbation theory and CCSD(T) levels, and found that the 2D structure has the lowest energy for H(+)(H(2)O)(7) [though nearly isoenergetic to the 3D structure for D(+)(D(2)O)(7)]. This structure has the Zundel-type configuration, but it shows the quantum probabilistic distribution including some of the Eigen-type configuration. The vibrational spectra of MP2/aug-cc-pVDZ calculations and Car-Parrinello molecular dynamics simulations, taking into account the thermal and dynamic effects, show that the 2D Zundel-type form is in good agreement with experiments.
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Affiliation(s)
- Ilgyou Shin
- Center for Superfunctional Materials, Department of Chemistry, Pohang University of Science and Technology, San 31, Hyojadong, Namgu, Pohang 790-784, Korea
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21
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Lim H, de Boer JF, Park BH, Lee EC, Yelin R, Yun SH. Optical frequency domain imaging with a rapidly swept laser in the 815-870 nm range. Opt Express 2006; 14:5937-44. [PMID: 19516763 DOI: 10.1364/oe.14.005937] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Optical frequency domain imaging (OFDI) in the 800-nm biological imaging window is demonstrated by using a novel wavelength-swept laser source. The laser output is tuned continuously from 815 to 870 nm at a 43.2-kHz repetition rate with 7-mW average power. Axial resolution of 10-mum in biological tissue and peak sensitivity of 96 dB are achieved. In vivo imaging of Xenopus laevis is demonstrated with an acquisition speed of 84 frames per second (512 axial lines per frame). This new imaging technique may prove useful in comprehensive retinal screening for medical diagnosis and contrast-agent-based imaging for biological investigations.
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22
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Yi HB, Diefenbach M, Choi YC, Lee EC, Lee HM, Hong BH, Kim KS. Interactions of Neutral and Cationic Transition Metals with the Redox System of Hydroquinone and Quinone: Theoretical Characterization of the Binding Topologies, and Implications for the Formation of Nanomaterials. Chemistry 2006; 12:4885-92. [PMID: 16671046 DOI: 10.1002/chem.200501551] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
To understand the self-assembly process of the transition metal (TM) nanoclusters and nanowires self-synthesized by hydroquinone (HQ) and calix[4]hydroquinone (CHQ) by electrochemical redox processes, we have investigated the binding sites of HQ for the transition-metal cations TM(n+)=Ag(+), Au(+), Pd(2+), Pt(2+), and Hg(2+) and those of quinone (Q) for the reduced neutral metals TM(0), using ab initio calculations. For comparison, TM(0)-HQ and TM(n+)-Q interactions, as well as the cases for Na(+) and Cu(+) (which do not take part in self-synthesis by CHQ) are also included. In general, TM-ligand coordination is controlled by symmetry constraints imposed on the respective orbital interactions. Calculations predict that, due to synergetic interactions, silver and gold are very efficient metals for one-dimensional (1D) nanowire formation in the self-assembly process, platinum and mercury favor both nanowire/nanorod and thin film formation, while palladium favors two-dimensional (2D) thin film formation.
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Affiliation(s)
- Hai-Bo Yi
- Center for Superfunctional Materials, Department of Chemistry, Pohang University of Science and Technology, Namgu, Pohang 790-784, Korea
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23
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Lee EC, Rafiq A, Merrell R, Ackerman R, Dennerlein JT. Ergonomics and human factors in endoscopic surgery: a comparison of manual vs telerobotic simulation systems. Surg Endosc 2005; 19:1064-70. [PMID: 16021368 DOI: 10.1007/s00464-004-8213-6] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2005] [Accepted: 02/09/2005] [Indexed: 02/05/2023]
Abstract
BACKGROUND Minimally invasive surgical techniques expose surgeons to a variety of occupational hazards that may promote musculoskeletal disorders. Telerobotic systems for minimally invasive surgery may help to reduce these stressors. The objective of this study was to compare manual and telerobotic endoscopic surgery in terms of postural and mental stress. METHODS Thirteen participants with no experience as primary surgeons in endoscopic surgery performed a set of simulated surgical tasks using two different techniques--a telerobotic master--slave system and a manual endoscopic surgery system. The tasks consisted of passing a soft spherical object through a series of parallel rings, suturing along a line 5-cm long, running a 32-in ribbon, and cannulation. The Job Strain Index (JSI) and Rapid Upper Limb Assessment (RULA) were used to quantify upper extremity exposure to postural and force risk factors. Task duration was quantified in seconds. A questionnaire provided measures of the participants' intuitiveness and mental stress. RESULTS The JSI and RULA scores for all four tasks were significantly lower for the telerobotic technique than for the manual one. Task duration was significantly longer for telerobotic than for manual tasks. Participants reported that the telerobotic technique was as intuitive as, and no more stressful than, the manual technique. CONCLUSIONS Given identical tasks, the time to completion is longer using the telerobotic technique than its manual counterpart. For the given simulated tasks in the laboratory setting, the better scores for the upper extremity postural analysis indicate that telerobotic surgery provides a more comfortable environment for the surgeon without any additional mental stress.
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Affiliation(s)
- E C Lee
- Department of Environmental Health, Harvard School of Public Health, Boston, MA 02115, USA
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24
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Abstract
The edge-to-face interactions for either axially or facially substituted benzenes are investigated by using ab initio calculations. The predicted maximum energy difference between substituted and unsubstituted systems is approximately 0.7 kcal/mol (approximately 1.2 kcal/mol if substituents are on both axially and facially substituted positions). In the case of axially substituted aromatic systems, the electron density at the para position is an important stabilizing factor, and thus the stabilization/destabilization by substitution is highly correlated to the electrostatic energy. This results in its subsequent correlation with the polarization and charge transfer. Thus, the stabilization/destabilization by substitution is represented by the sum of electrostatic energy and induction energy. On the other hand, the facially substituted aromatic system depends on not only the electron-donating ability responsible for the electrostatic energy but also the dispersion interaction and exchange repulsion. Although the dispersion energy is the most dominating interaction in both axial and facial substitutions, it is almost canceled by the exchange repulsion in the axial substitution, whereas in the facial substitution, together with the exchange repulsion it augments the electrostatic energy. The systems with electron-accepting substituents (NO2, CN, Br, Cl, F) favor the axial substituent conformation, while those with electron-donating substituents (NH2, CH3, OH) favor the facial substituent conformation. The interactions for the T-shape complex systems of an aromatic ring with other counterpart such as H2, H2O, HCl, and HF are also studied.
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Affiliation(s)
- Eun Cheol Lee
- National Creative Research Initiative Center for Superfunctional Materials, Department of Chemistry, Division of Molecular and Life Sciences, Pohang University of Science and Technology, San 31, Hyojadong, Namgu, Pohang 790-784, Korea
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25
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Abstract
To understand the hydration phenomena of noble transition metals, we investigated the structures, hydration energies, electronic properties, and spectra of the Cu(+)(H(3)O)(1-6) and Au(+)(H(2)O)(1-6) clusters using ab initio calculations. The coordination numbers of these clusters are found to be only two, which is highly contrasted to those of Ag(+)(H(2)O)(n) (which have the coordination numbers of 3-4) as well as the hydrated alkali metal ions (which have the coordination numbers of approximately 6). For the possible identification of their interesting hydration structures, we predict their IR spectra for the OH stretch modes.
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Affiliation(s)
- Han Myoung Lee
- National Creative Research Initiative Center for Superfunctional Materials, Department of Chemistry, Division of Molecular and Life Sciences, Pohang University of Science and Technology, San 31, Hyojadong, Namgu, Pohang 790-784, Korea
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26
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27
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Kim HG, Lee CW, Yun S, Hong BH, Kim YO, Kim D, Ihm H, Lee JW, Lee EC, Tarakeshwar P, Park SM, Kim KS. An Electrochemically Controllable Nanomechanical Molecular System Utilizing Edge-to-Face and Face-to-Face Aromatic Interactions. Org Lett 2003. [DOI: 10.1021/ol034183g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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28
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Kim KS, Suh SB, Kim JC, Hong BH, Lee EC, Yun S, Tarakeshwar P, Lee JY, Kim Y, Ihm H, Kim HG, Lee JW, Kim JK, Lee HM, Kim D, Cui C, Youn SJ, Chung HY, Choi HS, Lee CW, Cho SJ, Jeong S, Cho JH. Assembling phenomena of calix[4]hydroquinone nanotube bundles by one-dimensional short hydrogen bonding and displaced pi-pi stacking. J Am Chem Soc 2002; 124:14268-79. [PMID: 12440926 DOI: 10.1021/ja0259786] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Using the computer-aided molecular design approach, we recently reported the synthesis of calix[4]hydroquinone (CHQ) nanotube arrays self-assembled with infinitely long one-dimensional (1-D) short hydrogen bonds (H-bonds) and aromatic-aromatic interactions. Here, we assess various calculation methods employed for both the design of the CHQ nanotubes and the study of their assembly process. Our calculations include ab initio and density functional theories and first principles calculations using ultrasoft pseudopotential plane wave methods. The assembly phenomena predicted prior to the synthesis of the nanotubes and details of the refined structure and electronic properties obtained after the experimental characterization of the nanotube crystal are reported. For better characterization of intriguing 1-D short H-bonds and exemplary displaced pi-pi stacks, the X-ray structures have been further refined with samples grown in different solvent conditions. Since X-ray structures do not contain the positions of H atoms, it is necessary to analyze the system using quantum theoretical calculations. The competition between H-bonding and displaced pi-pi stacking in the assembling process has been clarified. The IR spectroscopic features and NMR chemical shifts of 1-D short H-bonds have been investigated both experimentally and theoretically. The dissection of the two most important interaction components leading to self-assembly processes would help design new functional materials and nanomaterials.
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Affiliation(s)
- Kwang S Kim
- National Creative Research Initiative Center for Superfunctional Materials and Department of Chemistry, Division of Molecular and Life Sciences, Pohang University of Science and Technology, San 31, Hyojadong, Namgu, Pohang 790-784, Korea.
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29
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Kim HG, Lee CW, Yun S, Hong BH, Kim YO, Kim D, Ihm H, Lee JW, Lee EC, Tarakeshwar P, Park SM, Kim KS. An electrochemically controllable nanomechanical molecular system utilizing edge-to-face and face-to-face aromatic interactions. Org Lett 2002; 4:3971-4. [PMID: 12599505 DOI: 10.1021/ol0268541] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
[formula: see text] A new molecular system, 2,11-dithio[4,4]metametaquinocyclophane containing a quinone moiety, was designed and synthesized. As the quinone moiety can readily be converted into an aromatic pi-system (hydroquinone) upon reduction, the nanomechanical molecular cyclophane system exhibits a large flapping motion like a molecular flipper from the electrochemical redox process. The conformational changes upon reduction and oxidation are caused by changes of nonbonding interaction forces (devoid of bond formation/breaking) from the edge-to-face to face-to-face aromatic interactions and vice versa, respectively.
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Affiliation(s)
- Heon Gon Kim
- National Creative Research Initiative Center for Superfunctional Materials, Department of Chemistry, Pohang University of Science and Technology, San 31, Hyojadong, Namgu, Pohang 790-784, Korea
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30
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Lee EC, Soliman AM, Kim J. Traumatic auricular hematoma: a case report. J Craniomaxillofac Trauma 2002; 3:32-5. [PMID: 11951269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
Traumatic recurrent auricular hematoma can be a challenging medical problem, with complications resulting in cauliflower ear. Proper management often depends on an understanding of the pathophysiology and pathogenesis of fibroneocartilage--an abnormal fibrous cartilage formation in response to injury. Traditional treatment by incision and drainage, and compression dressing technique may be inadequate in the setting of recurrent or chronic hematoma. Instead, excision of the fibroneocartilage is essential in promoting hematoma resolution and wound healing. Appropriate treatment of auricular hematoma can reduce needless cosmetic deformity and can avoid difficult secondary reconstruction. The authors present a case of recurrent auricular hematoma and review its pathophysiology and current therapy.
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Affiliation(s)
- E C Lee
- Otolaryngology Division, Wilmington Veterans Administration Hospital, 1601 Kirkwood Highway, Wilmington, DE 19805, USA
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Lee EC, Yu D, Martinez de Velasco J, Tessarollo L, Swing DA, Court DL, Jenkins NA, Copeland NG. A highly efficient Escherichia coli-based chromosome engineering system adapted for recombinogenic targeting and subcloning of BAC DNA. Genomics 2001; 73:56-65. [PMID: 11352566 DOI: 10.1006/geno.2000.6451] [Citation(s) in RCA: 972] [Impact Index Per Article: 42.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Recently, a highly efficient recombination system for chromosome engineering in Escherichia coli was described that uses a defective lambda prophage to supply functions that protect and recombine a linear DNA targeting cassette with its substrate sequence (Yu et al., 2000, Proc. Natl. Acad. Sci. USA 97, 5978-5983). Importantly, the recombination is proficient with DNA homologies as short as 30-50 bp, making it possible to use PCR-amplified fragments as the targeting cassette. Here, we adapt this prophage system for use in bacterial artificial chromosome (BAC) engineering by transferring it to DH10B cells, a BAC host strain. In addition, arabinose inducible cre and flpe genes are introduced into these cells to facilitate BAC modification using loxP and FRT sites. Next, we demonstrate the utility of this recombination system by using it to target cre to the 3' end of the mouse neuron-specific enolase (Eno2) gene carried on a 250-kb BAC, which made it possible to generate BAC transgenic mice that specifically express Cre in all mature neurons. In addition, we show that fragments as large as 80 kb can be subcloned from BACs by gap repair using this recombination system, obviating the need for restriction enzymes or DNA ligases. Finally, we show that BACs can be modified with this recombination system in the absence of drug selection. The ability to modify or subclone large fragments of genomic DNA with precision should facilitate many kinds of genomic experiments that were difficult or impossible to perform previously and aid in studies of gene function in the postgenomic era.
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MESH Headings
- Animals
- Bacteriophage lambda/genetics
- Bacteriophage lambda/physiology
- Chromosomes, Artificial, Bacterial/genetics
- Cloning, Molecular/methods
- DNA, Bacterial/genetics
- DNA, Recombinant/genetics
- Defective Viruses/genetics
- Defective Viruses/physiology
- Escherichia coli/genetics
- Genes, Bacterial
- Genes, Reporter
- Genetic Engineering/methods
- Mice
- Mice, Transgenic
- Oligodeoxyribonucleotides/chemical synthesis
- Oligodeoxyribonucleotides/genetics
- Plasmids/genetics
- Recombination, Genetic
- Transformation, Bacterial
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Affiliation(s)
- E C Lee
- Mouse Cancer Genetics Program, National Cancer Institute-Frederick, Frederick, Maryland 21702, USA
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Wilson SM, Householder DB, Coppola V, Tessarollo L, Fritzsch B, Lee EC, Goss D, Carlson GA, Copeland NG, Jenkins NA. Mutations in Cdh23 cause nonsyndromic hearing loss in waltzer mice. Genomics 2001; 74:228-33. [PMID: 11386759 DOI: 10.1006/geno.2001.6554] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Mutations at the waltzer (v) locus result in deafness and vestibular dysfunction due to degeneration of the neuroepithelium within the inner ear. Here, we use a positional cloning approach to show that waltzer encodes a novel cadherin (Cdh23), which is most closely related to the Drosophila Fat protein. A single nucleotide deletion in the v(J) allele and a single nucleotide insertion in the v allele are predicted to truncate each protein near the N-terminus and produce a functional null allele. In situ hybridization analysis showed that Cdh23 is expressed in the sensory hair cells of the inner ear, where it has been suggested to be a molecule critical for crosslinking of the stereocilia. In addition, Cdh23 is expressed in the urticulo-saccular foramen,the ductus reuniens, and Reissner's membrane, suggesting that Cdh23 may also be involved in maintaining the ionic composition of the endolymph. Finally, mutations in human CDH23 have recently been described for two loci, DFNB12 and USH1D, which cause nonsyndromic deafness, identifying waltzer as a mouse model for human hearing loss.
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MESH Headings
- Alleles
- Amino Acid Sequence
- Animals
- Cadherin Related Proteins
- Cadherins/biosynthesis
- Cadherins/genetics
- Chromosome Mapping
- Chromosomes, Artificial, Bacterial
- Chromosomes, Artificial, Yeast
- Cloning, Molecular
- Crosses, Genetic
- DNA, Complementary/metabolism
- Deafness/genetics
- Deafness/metabolism
- Drosophila
- Gene Library
- Humans
- In Situ Hybridization
- Membrane Proteins/genetics
- Mice
- Mice, Mutant Strains
- Models, Genetic
- Molecular Sequence Data
- Mutation
- Physical Chromosome Mapping
- Point Mutation
- Polymorphism, Genetic
- Polymorphism, Restriction Fragment Length
- Protein Structure, Tertiary
- Reverse Transcriptase Polymerase Chain Reaction
- Tissue Distribution
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Affiliation(s)
- S M Wilson
- Mouse Cancer Genetics Program, National Cancer Institute-Frederick, Frederick, Maryland 21702, USA
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33
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Abstract
A rapid method obviating the use of selectable markers to genetically manipulate large DNA inserts cloned into bacterial artificial chromosomes is described. Mutations such as single-base changes, deletions, and insertions can be recombined into a BAC by using synthetic single-stranded oligonucleotides as targeting vectors. The oligonucleotides include the mutated sequence flanked by short homology arms of 35-70 bases on either side that recombine with the BAC. In the absence of any selectable marker, modified BACs are identified by specific PCR amplification of the mutated BAC from cultures of pooled bacterial cells. Each pool represents about 10 electroporated cells from the original recombination mixture. Subsequently, individual clones containing the desired alteration are identified from the positive pools. Using this BAC modification method, we have observed a frequency of one recombinant clone per 90-260 electroporated cells. The combination of high targeting frequency and the sensitive yet selective PCR-based screening method makes BAC manipulation using oligonucleotides both rapid and simple.
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Affiliation(s)
- S Swaminathan
- Mouse Cancer Genetics Program, National Cancer Institute-Frederick, Frederick, Maryland 21702-1201, USA
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34
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Wilson SM, Toth PT, Oh SB, Gillard SE, Volsen S, Ren D, Philipson LH, Lee EC, Fletcher CF, Tessarollo L, Copeland NG, Jenkins NA, Miller RJ. The status of voltage-dependent calcium channels in alpha 1E knock-out mice. J Neurosci 2000; 20:8566-71. [PMID: 11102459 PMCID: PMC6773068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023] Open
Abstract
It has been hypothesized that R-type Ca currents result from the expression of the alpha(1E) gene. To test this hypothesis we examined the properties of voltage-dependent Ca channels in mice in which the alpha(1E) Ca channel subunit had been deleted. Application of omega-conotoxin GVIA, omega-agatoxin IVA, and nimodipine to cultured cerebellar granule neurons from wild-type mice inhibited components of the whole-cell Ba current, leaving a "residual" R current with an amplitude of approximately 30% of the total Ba current. A minor portion of this R current was inhibited by the alpha(1E)-selective toxin SNX-482, indicating that it resulted from the expression of alpha(1E). However, the majority of the R current was not inhibited by SNX-482. The SNX-482-sensitive portion of the granule cell R current was absent from alpha(1E) knock-out mice. We also identified a subpopulation of dorsal root ganglion (DRG) neurons from wild-type mice that expressed an SNX-482-sensitive component of the R current. However as with granule cells, most of the DRG R current was not blocked by SNX-482. We conclude that there exists a component of the R current that results from the expression of the alpha(1E) Ca channel subunit but that the majority of R currents must result from the expression of other Ca channel alpha subunits.
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MESH Headings
- Animals
- Barium/pharmacology
- Blotting, Western
- Calcium/metabolism
- Calcium Channel Blockers/pharmacology
- Calcium Channels, R-Type/drug effects
- Calcium Channels, R-Type/genetics
- Calcium Channels, R-Type/metabolism
- Cell Survival/genetics
- Cells, Cultured
- Cerebellum/cytology
- Cerebellum/drug effects
- Cerebellum/metabolism
- Electrophysiology
- Ganglia, Spinal/cytology
- Ganglia, Spinal/drug effects
- Ganglia, Spinal/metabolism
- Ion Transport/drug effects
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Neurons/cytology
- Neurons/drug effects
- Neurons/metabolism
- Nimodipine/pharmacology
- Patch-Clamp Techniques
- Protein Subunits
- Spider Venoms/pharmacology
- Synaptic Transmission/drug effects
- omega-Agatoxin IVA/pharmacology
- omega-Conotoxin GVIA/pharmacology
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Affiliation(s)
- S M Wilson
- Mouse Cancer Genetics Program, National Cancer Institute-Frederick Cancer Research and Development Center, Frederick, Maryland 21702, USA
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35
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Abstract
Notch (N) is a receptor for signals that inhibit neural precursor specification [1-6]. As N and its ligand Delta (DI) are expressed homogeneously, other molecules may be differentially expressed or active to permit neural precursor cells to arise intermingled with nonneural cells [7,8]. During Drosophila wing development, the glycosyltransferase encoded by the gene fringe (fng) promotes N signaling in response to DI, but inhibits N signaling in response to Serrate (Ser), which encodes a ligand that is structurally similar to DI. Dorsal expression of Fng protein localizes N signaling to the dorsoventral (DV) wing margin [9-11]. The secreted protein Scabrous (Sca) is a candidate for modulation of N in neural cells. Mutations at the scabrous (sca) locus alter the locations where precursor cells form in the peripheral nervous system [12,13]. Unlike fringe, sca mutations act cell non-autonomously [12]. Here, we report that targeted misexpression of Sca during wing development inhibited N signaling, blocking expression of all N target genes. Sca reduced N activation in response to DI more than in response to Ser. Ligand-independent signaling by overexpression of N protein, or by expression of activated truncated N molecules, was not inhibited by Sca. Our results indicate that Sca can act on N to reduce its availability for paracrine and autocrine interactions with DI and Ser, and can act as an antagonist of N signaling.
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Affiliation(s)
- E C Lee
- Department of Molecular Genetics, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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Yu D, Ellis HM, Lee EC, Jenkins NA, Copeland NG, Court DL. An efficient recombination system for chromosome engineering in Escherichia coli. Proc Natl Acad Sci U S A 2000; 97:5978-83. [PMID: 10811905 PMCID: PMC18544 DOI: 10.1073/pnas.100127597] [Citation(s) in RCA: 1353] [Impact Index Per Article: 56.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A recombination system has been developed for efficient chromosome engineering in Escherichia coli by using electroporated linear DNA. A defective lambda prophage supplies functions that protect and recombine an electroporated linear DNA substrate in the bacterial cell. The use of recombination eliminates the requirement for standard cloning as all novel joints are engineered by chemical synthesis in vitro and the linear DNA is efficiently recombined into place in vivo. The technology and manipulations required are simple and straightforward. A temperature-dependent repressor tightly controls prophage expression, and, thus, recombination functions can be transiently supplied by shifting cultures to 42 degrees C for 15 min. The efficient prophage recombination system does not require host RecA function and depends primarily on Exo, Beta, and Gam functions expressed from the defective lambda prophage. The defective prophage can be moved to other strains and can be easily removed from any strain. Gene disruptions and modifications of both the bacterial chromosome and bacterial plasmids are possible. This system will be especially useful for the engineering of large bacterial plasmids such as those from bacterial artificial chromosome libraries.
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Affiliation(s)
- D Yu
- Gene Regulation and Chromosome Biology Laboratory and Mouse Cancer Genetics Program, National Cancer Institute, Division of Basic Science, National Cancer Institute/Frederick Cancer Research and Development Center, Frederick, MD 21702, USA
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Lederman ED, McCoy G, Conti DJ, Lee EC. Diverticulitis and polycystic kidney disease. Am Surg 2000; 66:200-3. [PMID: 10695753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
Patients with adult polycystic kidney disease (PKD) have previously been shown to have an increased incidence of complicated diverticulitis after renal transplantation. The purpose of this study was to assess the risk of diverticulitis in the PKD population. We retrospectively reviewed patients with advanced PKD, defined as end-stage renal failure requiring dialysis. Patients were obtained from a single nephrology group practice between January 1985 and January 1997, or from all patients being evaluated or actively considered for renal transplantation at our institution as of May 1997. The incidence and severity of diverticulitis in these patients was compared with that observed in a similar cohort of patients with end-stage renal disease due to other etiologies. The study population consisted of 184 renal failure patients, 59 with PKD and 125 with other causes of end-stage renal disease. Twelve (20%) patients with PKD had a history of active diverticulitis, whereas only 4 (3%) of the non-PKD controls had diverticulitis (P = 0.0003, Fisher's exact test). Six of the 12 PKD patients required surgical intervention. Patients with renal failure due to PKD experience a significantly higher rate of diverticulitis than do other patients with end-stage renal disease. Furthermore, diverticulitis is frequently severe in PKD patients, with 50 per cent requiring surgical intervention. These data suggest that diverticular disease may be an extrarenal manifestation of polycystic kidney disease.
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Affiliation(s)
- E D Lederman
- Division of General Surgery, Albany Medical College, New York 12208, USA
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Lee EC, Walmsley S, Fantus IG. New-onset diabetes mellitus associated with protease inhibitor therapy in an HIV-positive patient: case report and review. CMAJ 1999; 161:161-4. [PMID: 10439826 PMCID: PMC1230467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023] Open
Affiliation(s)
- E C Lee
- Department of Medicine, Mount Sinai Hospital, Toronto, Ont
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Lee EC, Yu SY, Hu X, Mlodzik M, Baker NE. Functional analysis of the fibrinogen-related scabrous gene from Drosophila melanogaster identifies potential effector and stimulatory protein domains. Genetics 1998; 150:663-73. [PMID: 9755198 PMCID: PMC1460338 DOI: 10.1093/genetics/150.2.663] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The scabrous (sca) gene encodes a secreted dimeric glycoprotein with putative coiled-coil domains N-terminally and a C-terminal region related to the blood clot protein fibrinogen. Homozygous sca mutants have extra bristle organs and rough eyes. We describe a GAL4-based expression system for testing rescue of the sca mutant phenotype by altered SCA proteins and for misexpression. We find that deletion of the fibrinogen-related domain (FReD) greatly decreases SCA function, confirming the importance of this conserved region. SCA function could not be restored by FReDs from human fibrinogen chain genes. However, proteins lacking any FReD still showed some function in both rescue and misexpression experiments, suggesting that putative effector-binding regions lie outside this domain. Consistent with this, proteins expressing only the FReD had no rescuing activity but were recessive negative; i.e., they enhanced the phenotype of sca mutations but had no phenotype in the presence of a wild-type sca allele. This suggests that the FReD contributes to SCA function by binding to other components of the bristle determination pathway, increasing the activity of the linked N-terminal region.
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Affiliation(s)
- E C Lee
- Department of Molecular Genetics, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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Abstract
PURPOSE Colonic perforations in renal transplant recipients have historically been associated with mortality rates as high as 50 to 100 percent. However, these previous series generally predate the use of cyclosporine-based immunosuppressive protocols. METHODS We retrospectively reviewed all patients who had undergone renal transplant from our institution and who developed complicated diverticulitis. Complicated diverticulitis was defined as diverticulitis involving free perforation, abscess, phlegmon, or fistula. Factors analyzed included the time interval since transplantation, use of cyclosporine, living-related vs. cadaveric donor, cause of renal failure, and presenting signs and symptoms. RESULTS Between August 1969 and September 1996, 1,211 kidney transplants were performed in 1,137 patients. The first 388 patients (1969-1984) received prednisone and azathioprine, with cyclosporine added to the immunosuppressive regimen for the subsequent 823 recipients (1984-1996). Thirteen (1.1 percent) patients had episodes of complicated diverticulitis, occurring from 25 days to 14 years after transplant; all required surgical therapy. Clinical presentation was highly variable, ranging from asymptomatic pneumoperitoneum (2 patients) to generalized peritonitis. There was one perioperative mortality (7.7 percent). Patients with polycystic kidney disease as the cause of renal failure had a significantly higher rate of complicated diverticulitis. Specifically, patients with polycystic kidney disease (9 percent of the total transplant population) accounted for 46 percent of the cases of diverticulitis (P < 0.001, Fisher's exact probability test). Neither treatment with cyclosporine nor donor source had a significant effect on the rate of diverticular complications (P = 0.36 and P = 0.99, respectively, Fisher's exact probability test). CONCLUSION Complicated diverticulitis following renal transplantation is rare, and the clinical presentation may be atypical in the immunosuppressed transplant recipient. Patients with polycystic kidney disease experience a significantly higher rate of complicated diverticulitis than do other transplant patients and, therefore, warrant aggressive diagnostic evaluation of even vague abdominal symptoms. In addition, pretransplant screening and prophylactic sigmoid resection in this high-risk population deserve consideration and further study.
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Affiliation(s)
- E D Lederman
- Department of Surgery, Albany Medical College, New York, USA
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Abstract
BACKGROUND Staged resection of the sigmoid colon has been the traditional strategy for treating patients who require nonelective surgery to manage complications of diverticular disease. Resection and primary anastomosis has not generally been recommended when the clinical setting is compromised by contiguous inflammation or inadequate mechanical cleansing of the colon because of concerns regarding the potential risk of anastomotic dehiscence. Although many reports have confirmed that intraoperative colonic lavage (ICL) is a safe method for relieving fecal loading of the colon to facilitate primary intestinal anastomosis in patients with mechanical obstruction of the distal colon, there is very limited experience with the use of this technique in treating acute inflammatory disorders of the colon. In this report, we present our results with ICL in the nonelective treatment of patients with complications of diverticulitis. METHODS Records of all patients undergoing urgent operations at the Lahey Clinic to treat complications of diverticular disease from July 1987 to January 1996 were reviewed. RESULTS Of 62 patients who required nonelective operations, 33 underwent ICL in an attempt to perform primary anastomosis. In five patients, the operation included creation of a colostomy. The indication for surgery was obstruction in 13 patients (39 percent), persistent abscess or phlegmon in 13 (39 percent), perforation in 6 patients (18 percent), and hemorrhage in 1 patient (3 percent). According to Hinchey's classification system, 18 patients had Stage I disease, 10 had Stage II, and 5 patients had Stage III disease. There were no patients with Stage IV disease. The single anastomotic complication in the series was responsible for the sole operative mortality. The morbidity rate of 42 percent, included three intraoperative complications (2 splenic injuries and 1 ureteral laceration), two intra-abdominal abscesses (6 percent), and six wound infections (18 percent). CONCLUSION In our experience, ICL has proven to be a safe method for accomplishing single-stage resection of the colon in selected patients with diverticulitis who require an urgent operation. When there is no evidence of diffuse purulent or feculent peritonitis, we believe this is the preferred method for treating patients who are hemodynamically stable.
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Affiliation(s)
- E C Lee
- Department of Colon and Rectal Surgery, Lahey Hitchcock Clinic, Burlington, Massachusetts 01805, USA
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Abstract
The Notch protooncogene encodes a receptor important for determination and differentiation of many cell types, and is conserved between vertebrates and invertebrates. It has been suggested that the secreted protein scabrous (sca) might be a Notch ligand acting in the peripheral nervous system. The sca protein was purified and a cell line expressing 18,000 Notch molecules per cell surface used to test sca binding by coimmunoprecipitation, cell adhesion assays, and binding with labeled sca. No interaction was detected between gp300sca and Notch or the related protein Delta, suggesting that sca acts through a distinct mechanism.
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Affiliation(s)
- E C Lee
- Department of Molecular Genetics, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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Abstract
BACKGROUND Recent pressures to decrease the cost of medical care have mandated preoperative outpatient bowel preparation (OBP) for elective colorectal surgery without any data documenting equivalent quality of care. This study examined the safety and efficacy of OBP compared with inpatient bowel preparation (IBP). METHODS Records of all patients who underwent OBP for elective colorectal resection since the inception of the OBP program from July 1993 to June 1994 were compared with records of all patients who received IBP for elective procedures from January to June 1993. RESULTS The two groups, 90 patients who underwent OBP and 98 patients who had IBP, were well matched for age, sex, diagnosis, and operations performed. The OBP group had a shorter length of hospital stay (median, 7 vs. 9 days; P < 0.0001; chi-squared analysis), whereas the complication rate was similar (19 percent in the OBP group vs. 18 percent in the IBP group), including infectious complications (10 percent in the OBP group vs. 7 percent in the IBP group). Although operating time was similar (mean, 199 vs. 213 minutes) and estimated blood loss (mean, 528 vs. 536 ml), the OBP group had significantly higher perioperative fluid requirements: intraoperative fluids (median, 4300 vs. 3700 ml; P < 0.05; Student's t-test), intraoperative colloid administration (48 vs. 29 percent; P < 0.0002; chi-squared), 24-hour postoperative fluids (3224 vs. 2700 ml; P < 0.0001; Student's t-test), and postoperative fluid challenges (50 vs. 20 percent; P < 0.0001; chi-squared analysis). CONCLUSION Outpatient bowel preparation for elective colorectal surgery is safe and effective. It offers shorter hospital stay, and, therefore, potentially reduces medical care cost. Patients with multiple medical problems may not tolerate extensive fluid shifts; therefore, other preoperative arrangements, such as inpatient or outpatient intravenous fluid therapy, need to be considered to minimize complications that may outweigh potential cost savings.
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Affiliation(s)
- E C Lee
- Department of Colon and Rectal Surgery, Lahey Hitchcock Clinic, Burlington, Massachusetts 01805, USA
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Lee EC, Hu X, Yu SY, Baker NE. The scabrous gene encodes a secreted glycoprotein dimer and regulates proneural development in Drosophila eyes. Mol Cell Biol 1996; 16:1179-88. [PMID: 8622662 PMCID: PMC231100 DOI: 10.1128/mcb.16.3.1179] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
R8 photoreceptor cells play a primary role in the differentiation of Drosophila eyes. In scabrous (sca) mutants, the pattern of R8 photoreceptor differentiation is altered. The sca gene is predicted to encode a secreted protein related in part to fibrinogen and tenascins. Using expression in Drosophila Schneider cells, we showed that sca encoded a dimeric glycoprotein which was secreted and found in soluble form in the tissue culture medium. The sca protein contained both N- and O-linked carbohydrates and interacted with heparin. This Schneider cell protein was similar to protein detected in embryos. We showed that sca mutations, along with conditional alleles of Notch (N) and Delta (Dl), each affected the pattern of cells expressing atonal (ato), the proneural gene required for R8 differentiation. In normal development, about 1 cell in 20 differentiates into an R8 cell; in the others, ato is repressed. N and Dl were required to repress ato in the vicinity of R8 cells, whereas sca had effects over several cell diameters. Certain antibodies detected uptake of sca protein several cells away from its source. The overall growth factor-like structure of sca protein, its solubility, and its range of effects in vivo are consistent with a diffusible role that complements mechanisms involving direct cell contact. We propose that as the morphogenic furrow advances, cell secreting sca protein control the pattern of the next ommatidial column.
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Affiliation(s)
- E C Lee
- Department of Molecular Genetics, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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Affiliation(s)
- E C Lee
- Department of Otolaryngology/Head & Neck Surgery, Columbia Presbyterian Medical Center, New York, USA
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Hu X, Lee EC, Baker NE. Molecular analysis of scabrous mutant alleles from Drosophila melanogaster indicates a secreted protein with two functional domains. Genetics 1995; 141:607-17. [PMID: 8647397 PMCID: PMC1206760 DOI: 10.1093/genetics/141.2.607] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Mutations at the scabrous locus (sca) affect cell-cell signaling during neural development. Twenty-one mutant alleles of scabrous have been analyzed. Many synthesize no sca protein. In others, a defective protein is arrested intracellularly. Two mutants in which protein is not arrested must affect sca protein function outside the cell. Both affect the fibrinogen related domain (FReD), a 200-amino acid segment conserved in fibrinogen, tenascins, and other proteins. In fibrinogen, this region is involved in protein interactions and is altered in human mutations affecting blood clotting. In sca(UM2), an invariant Asp residue is replaced by Asn. In sca(MSKF) allele has dominant negative properties, indicating that the truncated amino-terminal portion interferes with the function of so me other gene product. These mutations show that the conserved FReD is essential for wild-type sca function, but suggest that the amino-terminal domain also interacts with other proteins, but other neural mutations were without effect. Models for the role of a two-domain protein in neural development are discussed.
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Affiliation(s)
- X Hu
- Department of Molecular Genetics, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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Affiliation(s)
- E C Lee
- Department of Otolaryngology, Columbia-Presbyterian Medical Center, New York, NY, USA
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Lee EC. General practice screening clinic for Bangladeshi families. Br J Gen Pract 1994; 44:268-70. [PMID: 8037982 PMCID: PMC1238899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
AIM A screening clinic for Bangladeshi families was established in order to improve the health care provided by one general practice to its Bangladeshi patients. METHOD The clinic was run by a general practitioner, a health visitor and a Bangladeshi health worker. Patients were invited to attend household by household. The composition of each household was recorded using a genogram. Details of family illness, housing and employment were noted. A medical history was taken from each individual. Every adult was screened for diabetes and risk factors for coronary heart disease; cervical cytology was offered to women. The immunization status of all patients was recorded and adults were immunized. Children were referred to the child health clinic for immunizations. The clinic concluded with a health education session focusing on smoking, exercise and diet. RESULTS Over a two year period, 58% of the Bangladeshi families registered with the practice attended the clinic, a total of 207 people. Meeting Bangladeshi patients household by household was an effective and apparently efficient way of providing basic screening and health education. It allowed the practice to learn about the structure of its Bangladeshi families, the social problems faced by their community, and the areas in which their health care could be improved. CONCLUSION This clinic provides a model which could be adapted for use with other ethnic or 'hard-to-reach' groups. It may also prove an effective way of screening all families in general practice.
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Lee CH, Lee EC, Tsai ST, Kung HJ, Liu YC, Hwang J. An EGF-pseudomonas exotoxin A recombinant protein with a deletion in toxin binding domain specifically kills EGF receptor bearing cells. Protein Eng Des Sel 1993; 6:433-40. [PMID: 8332601 DOI: 10.1093/protein/6.4.433] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
We constructed two chimeric toxins; one composed of epidermal growth factor (EGF) and pseudomonas exotoxin A (PE), designated EGF-PE and the other composed of EGF and PE with a deletion of the Ia domain (cell-binding domain), designated EGF-PE (delta Ia). Both chimeric toxins reacted with anti-EGF and anti-PE antibodies. The cell-killing experiments showed that EGF-PE, but not EGF-PE (delta Ia), was cytotoxic to the murine fibroblast cell line NR6, which carried the PE receptor, but not the EGF receptor. However, after NR6 was transfected with DNA for the expression of human EGF receptor, the transfected cell line, designated NRHER5, over-expressed human EGF receptors and became sensitive to EGF-PE(delta IA). The cytotoxicity of EGF-PE(delta Ia), but not EGF-PE, to NRHER5 can be completely blocked by an excess amount of EGF. To completely reverse the cytotoxicity of EGF-PE on NRHER5, both the EGF receptor pathway and the PE receptor pathway need to be blocked. These results suggest that EGF-PE exhibits both EGF and PE binding activities, while EGF-PE(delta IA) possesses only EGF binding activity. Thus, EGF-PE(delta Ia) may be a better chimeric toxin than EGF-PE in terms of target specificity to EGF receptor bearing cells. We, therefore, examined the cytotoxicity of EGF-PE(delta Ia) to various human cancer cell lines. We find that human cancer cells containing more EGF receptors are more sensitive to EGF-PE(delta Ia).
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Affiliation(s)
- C H Lee
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
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Lotz MM, Andrews CW, Korzelius CA, Lee EC, Steele GD, Clarke A, Mercurio AM. Decreased expression of Mac-2 (carbohydrate binding protein 35) and loss of its nuclear localization are associated with the neoplastic progression of colon carcinoma. Proc Natl Acad Sci U S A 1993; 90:3466-70. [PMID: 7682704 PMCID: PMC46321 DOI: 10.1073/pnas.90.8.3466] [Citation(s) in RCA: 172] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The Mac-2 lectin (carbohydrate binding protein 35) is a soluble, 32- to 35-kDa phosphoprotein that binds galactose-containing glycoconjugates. We report here that the colonic epithelium is a major site of Mac-2 expression in vivo based on immunohistochemistry of human tissue specimens. In this epithelium, proliferating cells at the base of the crypts do not express Mac-2 but its expression increases with differentiation along the crypt-to-surface axis. Mac-2 expression is concentrated in the nuclei of these differentiated epithelial cells. The progression from normal mucosa to adenoma to carcinoma is associated with significant changes in Mac-2 nuclear localization and expression. In all adenomas (9/9) and carcinomas (13/13) examined, Mac-2 was not present in the nucleus but was localized in the cytoplasm. Sequencing of Mac-2 cDNAs from normal mucosa and carcinoma revealed no specific mutations that could account for this loss of nuclear localization. We also observed a 5- to 10-fold decrease in Mac-2 mRNA levels in cancer compared to normal mucosa as well as a significant reduction in the amount of Mac-2 protein expressed. These observations suggest that Mac-2 exclusion from the nucleus and its decreased expression may be related to the neoplastic progression of colon cancer.
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MESH Headings
- Adenocarcinoma/metabolism
- Adenocarcinoma/pathology
- Amino Acid Sequence
- Antigens, Differentiation/biosynthesis
- Antigens, Differentiation/genetics
- Antigens, Differentiation/metabolism
- Base Sequence
- Blotting, Northern
- Cell Nucleus/metabolism
- Cell Nucleus/ultrastructure
- Cell Transformation, Neoplastic
- Cloning, Molecular
- Colon/cytology
- Colon/metabolism
- Colon/pathology
- Colonic Neoplasms/metabolism
- Colonic Neoplasms/pathology
- Colonic Polyps/metabolism
- Colonic Polyps/pathology
- DNA/genetics
- DNA/isolation & purification
- DNA, Neoplasm/genetics
- DNA, Neoplasm/isolation & purification
- Galectin 3
- Humans
- Immunohistochemistry
- Intestinal Mucosa/cytology
- Intestinal Mucosa/metabolism
- Intestinal Mucosa/pathology
- Lectins/biosynthesis
- Lectins/genetics
- Lectins/metabolism
- Molecular Sequence Data
- Molecular Weight
- Oligodeoxyribonucleotides
- Polymerase Chain Reaction/methods
- RNA/genetics
- RNA/isolation & purification
- RNA, Messenger/genetics
- RNA, Messenger/isolation & purification
- RNA, Messenger/metabolism
- RNA, Neoplasm/genetics
- RNA, Neoplasm/isolation & purification
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Affiliation(s)
- M M Lotz
- Laboratory of Cancer Biology, Deaconess Hospital, Harvard Medical School, Boston, MA 02115
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