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Nguyen TH, Tran LT, Nguyen BC, Dinh NT, Mai HT, Pham QNM, Van Ho L, Ky TD, Nguyen TL. Rare Cause of Gastrointestinal Bleeding: A Case Report of Pancreatic Arteriovenous Malformation. Am J Case Rep 2023; 24:e941638. [PMID: 37995202 PMCID: PMC10684828 DOI: 10.12659/ajcr.941638] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Revised: 10/18/2023] [Accepted: 10/05/2023] [Indexed: 11/25/2023]
Abstract
BACKGROUND Arteriovenous malformation is an unusual cause of gastrointestinal bleeding, particularly in the pancreas. A definitive treatment strategy is not yet established. CASE REPORT We present the case of a 37-year-old man with underlying hypertension and no significant family history who presented with a 3-month history of intermittent epigastric pains and unintentional weight loss of 5 kg in 2 months. The upper endoscopy showed a large duodenal ulcer, which was uncontrolled with a standard dose of proton pump inhibitors. An abdominal computed tomography scan with contrast was indicated and revealed an enhanced mass of 2.5×3.5×4 cm in size, located on the second and third parts of the duodenum and head of the pancreas, indicating an arteriovenous malformation. On day 10 of hospitalization, the patient suddenly had melena and a drop of hemoglobin level to 5.6 g/dL; angiography intervention was successful to control the bleeding. However, gastrointestinal bleeding recurred after 2 weeks, and the patient successfully underwent a Whipple procedure. CONCLUSIONS The diagnosis and therapeutic management of arteriovenous malformations are uniquely challenging; therefore, pancreatic arteriovenous malformations should be listed on the differential diagnosis, particularly in those cases with non-healing and large duodenal ulcers. Otherwise, early imaging modalities should be performed to confirm the diagnosis. In particular, angiography can temporarily control bleeding before proceeding with more definitive therapy.
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Affiliation(s)
- Thanh Huu Nguyen
- Department of Internal Medicine, College of Health Sciences, VinUniversity, Hanoi, Vietnam
| | - Lam Tung Tran
- Department of Gastrointestinal, 108 Military Central Hospital, Hanoi, Vietnam
| | - Binh Canh Nguyen
- Department of Gastrointestinal, 108 Military Central Hospital, Hanoi, Vietnam
| | - Nga Thi Dinh
- Department of Gastrointestinal, 108 Military Central Hospital, Hanoi, Vietnam
| | - Hoai Thu Mai
- Department of Gastrointestinal, 108 Military Central Hospital, Hanoi, Vietnam
| | | | - Linh Van Ho
- Department of Surgical Gastroenterology, 108 Military Central Hospital, Hanoi, Vietnam
| | - Thai Doan Ky
- Department of Gastrointestinal, 108 Military Central Hospital, Hanoi, Vietnam
| | - Tung Lam Nguyen
- Department of Gastrointestinal, 108 Military Central Hospital, Hanoi, Vietnam
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Behrle T, Nguyen TL, Reiter F, Baur D, de Neeve B, Stadler M, Marinelli M, Lancellotti F, Yelin SF, Home JP. Phonon Laser in the Quantum Regime. Phys Rev Lett 2023; 131:043605. [PMID: 37566845 DOI: 10.1103/physrevlett.131.043605] [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] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 05/30/2023] [Indexed: 08/13/2023]
Abstract
We demonstrate a trapped-ion system with two competing dissipation channels, implemented independently on two ion species cotrapped in a Paul trap. By controlling coherent spin-oscillator couplings and optical pumping rates we explore the phase diagram of this system, which exhibits a regime analogous to that of a (phonon) laser but operates close to the quantum ground state with an average phonon number of n[over ¯]<10. We demonstrate phase locking of the oscillator to an additional resonant drive, and also observe the phase diffusion of the resulting state under dissipation by reconstructing the quantum state from a measurement of the characteristic function.
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Affiliation(s)
- T Behrle
- Institute for Quantum Electronics, ETH Zürich, Otto-Stern-Weg 1, 8093 Zürich, Switzerland
| | - T L Nguyen
- Institute for Quantum Electronics, ETH Zürich, Otto-Stern-Weg 1, 8093 Zürich, Switzerland
| | - F Reiter
- Institute for Quantum Electronics, ETH Zürich, Otto-Stern-Weg 1, 8093 Zürich, Switzerland
- Harvard University, 17 Oxford Street, Cambridge, Massachusetts 02138, USA
| | - D Baur
- Institute for Quantum Electronics, ETH Zürich, Otto-Stern-Weg 1, 8093 Zürich, Switzerland
| | - B de Neeve
- Institute for Quantum Electronics, ETH Zürich, Otto-Stern-Weg 1, 8093 Zürich, Switzerland
| | - M Stadler
- Institute for Quantum Electronics, ETH Zürich, Otto-Stern-Weg 1, 8093 Zürich, Switzerland
| | - M Marinelli
- Institute for Quantum Electronics, ETH Zürich, Otto-Stern-Weg 1, 8093 Zürich, Switzerland
| | - F Lancellotti
- Institute for Quantum Electronics, ETH Zürich, Otto-Stern-Weg 1, 8093 Zürich, Switzerland
| | - S F Yelin
- Harvard University, 17 Oxford Street, Cambridge, Massachusetts 02138, USA
| | - J P Home
- Institute for Quantum Electronics, ETH Zürich, Otto-Stern-Weg 1, 8093 Zürich, Switzerland
- Quantum Center, ETH Zürich, 8093 Zürich, Switzerland
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Le DT, Ngo MT, Dang VT, Nguyen TL. A sensorless anti-windup speed control approach to axial gap bearingless motors with nonlinear lumped mismatched disturbance observers. ISA Trans 2023; 138:408-431. [PMID: 36922337 DOI: 10.1016/j.isatra.2023.03.005] [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: 06/07/2022] [Revised: 12/19/2022] [Accepted: 03/04/2023] [Indexed: 06/16/2023]
Abstract
In this paper, sensorless robust speed control with nonlinear lumped mismatched disturbance observers for a permanent magnet type axial gap bearingless motor (AGBM) is designed. Multistage anti-windup-based dynamic surface control combined with integral backstepping control is proposed to control the motor's axial displacement and rotor speed. The approach is against parameter uncertainties and external disturbances, improving steady-state accuracy, eliminating the derivative explosion phenomenon, no chattering problem, and reducing the magnitude of the control system when current saturation occurs. In addition, a novel nonlinear lumped mismatched disturbance observer is proposed to improve the approach under unmodeled dynamics and external disturbances. To obtain high-accuracy tracking control, the control system includes the robust controller combined with the disturbance observers and anticipatory activation of anti-windup (AW) compensation, which means the controller is more complex. Then, to design a sensorless robust speed control for the motor, the rotor position and speed observer require higher accuracy. High-gain back-EMF observer combined with an improved phase-locked loop is proposed to estimate rotor angular position and speed even when the motor speed is reversed. Overall stability of closed-loop system control, including a sensorless speed control approach for motors using back-EMF estimation combined with saturation of the currents and lumped disturbance observers, is mathematically proven. Finally, the simulation results under measurement noise show that the proposed control system are obtained the effectiveness, feasibility, and robustness.
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Affiliation(s)
- Duc Thinh Le
- Hanoi University of Science and Technology, Hanoi, 100000, Viet Nam
| | - Manh Tung Ngo
- Hanoi University of Industry, Hanoi, 100000, Viet Nam
| | - Van Trong Dang
- Hanoi University of Science and Technology, Hanoi, 100000, Viet Nam
| | - Tung Lam Nguyen
- Hanoi University of Science and Technology, Hanoi, 100000, Viet Nam.
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Quach DT, Mai BH, Tran MK, Dao LV, Tran HV, Vu KT, Vu KV, Pham HTT, Bui HH, Ho DDQ, Trinh DT, Nguyen VT, Duong TH, Tran TTK, Nguyen HTV, Nguyen TT, Nguyen TD, Nguyen LC, Dao HV, Thai KD, Phan NT, Le LT, Vo CHM, Ho PT, Nguyen TL, Le QD, Le NV, Phan HQ, Nguyen BC, Tran TT, Tran TV, Ta L. Vietnam Association of Gastroenterology (VNAGE) consensus on the management of Helicobacter pylori infection. Front Med (Lausanne) 2023; 9:1065045. [PMID: 36714104 PMCID: PMC9878302 DOI: 10.3389/fmed.2022.1065045] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Accepted: 12/21/2022] [Indexed: 01/15/2023] Open
Abstract
Helicobacter pylori (H. pylori) infection is prevalent and has a rapidly increasing antibiotic resistance rate in Vietnam. Reinfection is quite common, and gastric carcinoma remains one of the most common malignancies, which is not uncommon to develop after successful eradication. The purpose of this consensus is to provide updated recommendations on the management of H. pylori infection in the country. The consensus panel consisted of 32 experts from 14 major universities and institutions in Vietnam who were invited to review the evidence and develop the statements using the Delphi method. The process followed the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system. The consensus level was defined as ≥80% for agreement on the proposed statements. Due to the limited availability of high-quality local evidence, this consensus was also based on high-quality evidence from international studies, especially those conducted in other populations in the Asia-Pacific region. The panel finally reached a consensus on 27 statements after two voting rounds, which consisted of four sections (1) indications for testing and selection of diagnostic tests (2), treatment regimens, (3) post-treatment confirmation of H. pylori status, and (4) reinfection prevention methods and follow-up after eradication. Important issues that require further evidence include studies on third-line regimens, strategies to prevent H. pylori reinfection, and post-eradication follow-up for precancerous gastric lesions. We hope this consensus will help guide the current clinical practice in Vietnam and promote multicenter studies in the country and international collaborations.
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Affiliation(s)
- Duc Trong Quach
- Department of Internal Medicine, University of Medicine and Pharmacy at Ho Chi Minh City, Ho Chi Minh City, Vietnam,Nhan Dan Gia Dinh Hospital, Ho Chi Minh City, Vietnam,*Correspondence: Duc Trong Quach, ; orcid.org/0000-0003-0141-921X
| | - Bang Hong Mai
- 108 Military Central Hospital, Hanoi, Vietnam,Bang Hong Mai,
| | - Mien Kieu Tran
- Department of Internal Medicine, University of Medicine and Pharmacy at Ho Chi Minh City, Ho Chi Minh City, Vietnam
| | - Long Van Dao
- Internal Medicine Faculty, Hanoi Medical University, Hanoi, Vietnam
| | - Huy Van Tran
- Hue University of Medicine and Pharmacy, Hue, Vietnam
| | | | | | - Ho Thi-Thu Pham
- Internal Medicine Faculty, Hanoi Medical University, Hanoi, Vietnam
| | - Hoang Huu Bui
- Department of Internal Medicine, University of Medicine and Pharmacy at Ho Chi Minh City, Ho Chi Minh City, Vietnam
| | | | | | - Vinh Thuy Nguyen
- Department of Internal Medicine, Hanoi National University, Hanoi, Vietnam
| | - Thai Hong Duong
- Department of Internal Medicine, Thai Nguyen University of Medicine and Pharmacy, Thai Nguyen, Vietnam
| | - Tuong Thi-Khanh Tran
- Department of Internal Medicine, Pham Ngoc Thach University of Medicine, Ho Chi Minh City, Vietnam
| | | | | | | | | | - Hang Viet Dao
- Internal Medicine Faculty, Hanoi Medical University, Hanoi, Vietnam
| | | | | | | | | | | | | | - Quang Dinh Le
- Department of Internal Medicine, University of Medicine and Pharmacy at Ho Chi Minh City, Ho Chi Minh City, Vietnam
| | - Nho Viet Le
- Department of Internal Medicine, Da Nang University of Medical Technology and Pharmacy, Da Nang, Vietnam
| | | | | | - Trung Thien Tran
- Department of Internal Medicine, University of Medicine and Pharmacy at Ho Chi Minh City, Ho Chi Minh City, Vietnam
| | | | - Long Ta
- 108 Military Central Hospital, Hanoi, Vietnam
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Chuyen TD, Hoa RV, Dien ND, Nguyen TL. Mobile robots interacting with obstacles control based on artificial intelligence. ANNALS OF COMPUTER SCIENCE AND INFORMATION SYSTEMS 2022. [DOI: 10.15439/2021r21] [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: 11/18/2022] Open
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Tan PV, Duc NQ, Minh LN, Manh CN, Nguyen DH, Nguyen TL. State Observer-Based Backstepping Sliding Mode Control for Electro-Hydraulic Systems. ANNALS OF COMPUTER SCIENCE AND INFORMATION SYSTEMS 2022. [DOI: 10.15439/2021r22] [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: 11/18/2022] Open
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Chuyen TD, Huy HV, Nguyen TL. Control design of an UAV–Q based on feedback linearization and optimum modulus methods. ANNALS OF COMPUTER SCIENCE AND INFORMATION SYSTEMS 2022. [DOI: 10.15439/2021r20] [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: 11/18/2022] Open
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Nguyen TL. Favouring imperfect awareness over perfect ignorance: Response to Knight & Cook regarding their comment on 'Incomparability of treatment groups is often blindly ignored in randomised controlled trials - a post hoc analysis of baseline characteristic tables'. J Clin Epidemiol 2021; 138:238-239. [PMID: 34139314 DOI: 10.1016/j.jclinepi.2021.05.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 05/19/2021] [Indexed: 11/29/2022]
Affiliation(s)
- T L Nguyen
- Section of Epidemiology, Department of Public Health, University of Copenhagen, Copenhagen, Denmark.
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Tran Doan Trung H, Lee D, Nguyen TL, Lee H. Image formation by a biological curved mirror array of the fisheye in the deep-sea environment. Appl Opt 2021; 60:5227-5235. [PMID: 34143092 DOI: 10.1364/ao.424812] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 05/21/2021] [Indexed: 06/12/2023]
Abstract
In this paper, we present the imaging formation process of the piecewise mirror eyes of the deep-sea spookfish, which has a strange combination of refractive and reflective eyes. The biological reflective eye structure is formulated to the curved surface's flat mirror array. Zemax is utilized to evaluate optical features such as the modulation transfer function, distortion, and imaging performances. However, the natural images are highly distorted, and the resolution is lower than expected. Therefore, we increase the number of piecewise mirrors of the fisheye to see higher quality images, which can be improved entirely by the mirror shapes. Finally, the fisheye's imaging analysis reveals the deep-sea creature's resolution limit and also shows the possibility of artificial and biomimetic camera applications.
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Fox GJ, Nguyen VN, Dinh NS, Nghiem LPH, Le TNA, Nguyen TA, Nguyen BH, Nguyen HD, Tran NB, Nguyen TL, Le TN, Nguyen VH, Phan TL, Nguyen KC, Ho J, Pham DC, Britton WJ, Bestrashniy JRBM, Marks GB. Post-treatment Mortality Among Patients With Tuberculosis: A Prospective Cohort Study of 10 964 Patients in Vietnam. Clin Infect Dis 2020; 68:1359-1366. [PMID: 30202910 DOI: 10.1093/cid/ciy665] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [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: 03/18/2018] [Accepted: 08/14/2018] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Tuberculosis is the leading infectious cause of death. Steep reductions in tuberculosis-related mortality are required to realize the World Health Organization's "End Tuberculosis Strategy." However, accurate mortality estimates are lacking in many countries, particularly following discharge from care. This study aimed to establish the mortality rate among patients with pulmonary tuberculosis in Vietnam and to quantify the excess mortality in this population. METHODS We conducted a prospective cohort study among adult patients treated for smear-positive pulmonary tuberculosis in 70 clinics across Vietnam. People living in the same households were recruited as controls. Participants were re-interviewed and their survival was established at least 2 years after their treatment with an 8-month standardized regimen. The presence of relapse was established by linking identifying data on patients and controls to clinic registries. Verbal autopsies were performed. The cumulative mortality among patients was compared to that among a control population, adjusting for age and gender. RESULTS We enrolled 10964 patients and 25707 household controls. Among enrolled tuberculosis patients, 9% of patients died within a median follow-up period of 2.9 years: 342 (3.1%) during treatment and 637 (5.8%) after discharge. The standardized mortality ratio was 4.0 (95% confidence interval 3.7-4.2) among patients with tuberculosis, compared to the control population. Tuberculosis was the likely cause of death for 44.7% of these deceased patients. CONCLUSIONS Patients treated for tuberculosis had a markedly elevated risk of death, particularly in the post-treatment period. Interventions to reduce tuberculosis mortality must enhance the early detection of drug-resistance, improve treatment effectiveness, and address non-communicable diseases.
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Affiliation(s)
- G J Fox
- Faculty of Medicine and Health, University of Sydney, Australia.,Woolcock Institute of Medical Research, Glebe, New South Wales, Australia
| | - V N Nguyen
- National Lung Hospital, Ba Dinh, Hanoi, Vietnam
| | - N S Dinh
- National Lung Hospital, Ba Dinh, Hanoi, Vietnam
| | - L P H Nghiem
- Woolcock Institute of Medical Research, Glebe, New South Wales, Australia
| | - T N A Le
- National Lung Hospital, Ba Dinh, Hanoi, Vietnam
| | - T A Nguyen
- Woolcock Institute of Medical Research, Glebe, New South Wales, Australia
| | - B H Nguyen
- National Lung Hospital, Ba Dinh, Hanoi, Vietnam.,Centre for Operational Research, International Union Against Tuberculosis and Lung Disease, Paris, France
| | - H D Nguyen
- Pham Ngoc Thach Hospital, Ho Chi Minh City, Vietnam
| | - N B Tran
- Woolcock Institute of Medical Research, Glebe, New South Wales, Australia
| | - T L Nguyen
- Woolcock Institute of Medical Research, Glebe, New South Wales, Australia
| | - T N Le
- Woolcock Institute of Medical Research, Glebe, New South Wales, Australia
| | - V H Nguyen
- Woolcock Institute of Medical Research, Glebe, New South Wales, Australia
| | - T L Phan
- Woolcock Institute of Medical Research, Glebe, New South Wales, Australia
| | - K C Nguyen
- National Lung Hospital, Ba Dinh, Hanoi, Vietnam.,Hanoi Medical University, Hanoi, Vietnam
| | - J Ho
- Faculty of Medicine and Health, University of Sydney, Australia
| | - D C Pham
- Woolcock Institute of Medical Research, Glebe, New South Wales, Australia
| | - W J Britton
- Faculty of Medicine and Health, University of Sydney, Australia.,Centenary Institute of Cancer Medicine and Cell Biology, University of Sydney, Camperdown, New South Wales, Australia
| | | | - G B Marks
- Woolcock Institute of Medical Research, Glebe, New South Wales, Australia.,South Western Sydney Clinical School, University of New South Wales, Kensington, New South Wales, Australia
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Liu X, Yang CY, Miao R, Zhou CL, Cao PH, Lan J, Zhu XJ, Mou CL, Huang YS, Liu SJ, Tian YL, Nguyen TL, Jiang L, Wan JM. DS1/OsEMF1 interacts with OsARF11 to control rice architecture by regulation of brassinosteroid signaling. Rice (N Y) 2018; 11:46. [PMID: 30084027 PMCID: PMC6082143 DOI: 10.1186/s12284-018-0239-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 07/27/2018] [Indexed: 05/05/2023]
Abstract
BACKGROUND Plant height and leaf angle are important determinants of yield in rice (Oryza sativa L.). Genes involved in regulating plant height and leaf angle were identified in previous studies; however, there are many remaining unknown factors that affect rice architecture. RESULTS In this study, we characterized a dwarf mutant named ds1 with small grain size and decreased leaf angle,selected from an irradiated population of ssp. japonica variety Nanjing35. The ds1 mutant also showed abnormal floral organs. ds1 plants were insensitive to BL treatment and expression of genes related to BR signaling was changed. An F2 population from a cross between ds1 and indica cultivar 93-11 was used to fine map DS1 and to map-based clone the DS1 allele, which encoded an EMF1-like protein that acted as a transcriptional regulator. DS1 was constitutively expressed in various tissues, and especially highly expressed in young leaves, panicles and seeds. We showed that the DS1 protein interacted with auxin response factor 11 (OsARF11), a major transcriptional regulator of plant height and leaf angle, to co-regulate D61/OsBRI1 expression. These findings provide novel insights into understanding the molecular mechanisms by which DS1 integrates auxin and brassinosteroid signaling in rice. CONCLUSION The DS1 gene encoded an EMF1-like protein in rice. The ds1 mutation altered the expression of genes related to BR signaling, and ds1 was insensitive to BL treatment. DS1 interacts with OsARF11 to co-regulate OsBRI1 expression.
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Affiliation(s)
- X Liu
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, China
| | - C Y Yang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, China
| | - R Miao
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, China
| | - C L Zhou
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, China
| | - P H Cao
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, China
| | - J Lan
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, China
| | - X J Zhu
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, China
| | - C L Mou
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, China
| | - Y S Huang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, China
| | - S J Liu
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, China
| | - Y L Tian
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, China
| | - T L Nguyen
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, China
| | - L Jiang
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, China.
| | - J M Wan
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, China.
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
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Burgess SN, Juergens CP, Nguyen TL, Leung M, Richards DAB, Thomas L, Mussap CJ, Lo STH, French JK. P1642The impact of residual non-culprit stenoses in diabetic and non-diabetic patients with ST elevation myocardial infarction. Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy565.p1642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- S N Burgess
- University of New South Wales, Liverpool hospital, Cardiology department, & Nepean Hospital, Cardiology department, Sydney, Australia
| | - C P Juergens
- University of New South Wales, Liverpool Hospital, Cardiology department, Sydney, Australia
| | - T L Nguyen
- University of New South Wales, Liverpool Hospital, Cardiology department, Sydney, Australia
| | - M Leung
- University of New South Wales, Liverpool Hospital, Cardiology department, Sydney, Australia
| | - D A B Richards
- University of New South Wales, Liverpool Hospital, Cardiology department, Sydney, Australia
| | - L Thomas
- University of New South Wales, & Westmead hospital, Cardiology department, Sydney, Australia
| | - C J Mussap
- University of New South Wales, Liverpool Hospital, Cardiology department, Sydney, Australia
| | - S T H Lo
- University of New South Wales, Liverpool Hospital, Cardiology department, Sydney, Australia
| | - J K French
- University of New South Wales, Liverpool Hospital, Cardiology department, Sydney, Australia
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Marengo S, Houde D, Brasseur N, Nguyen TL, Ouellet R, van Lier JE. Mesure du rendement d'oxygène singulet généré à partir de photosensibilisateurs tumoraux à base de naphtalocyanines. ACTA ACUST UNITED AC 2017. [DOI: 10.1051/jcp/1994911211] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Brasseur N, Nguyen TL, Langlois R, Ouellet R, Marengo S, Houde D, van Lier JE. Activité biologique de dérivés 2,3-naphtalocyanines de silicium comme sensibilisateurs potentiels en photochimiothérapie du cancer. ACTA ACUST UNITED AC 2017. [DOI: 10.1051/jcp/1994911011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Nguyen TL, Lim YJ, Kim DH, Austin B. Development of real-time PCR for detection and quantitation of Streptococcus parauberis. J Fish Dis 2016; 39:31-39. [PMID: 25345976 DOI: 10.1111/jfd.12322] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Revised: 09/06/2014] [Accepted: 09/07/2014] [Indexed: 06/04/2023]
Abstract
Streptococcus parauberis is an increasing threat to aquaculture of olive flounder, Paralichthys olivaceus Temminck & Schlegel, in South Korea. We developed a real-time polymerase chain reaction (PCR) method using the TaqMan probe assay to detect and quantify S. parauberis by targeting the gyrB gene sequences, which are effective for molecular analysis of the genus Streptococcus. Our real-time PCR assay is capable of detecting 10 fg of genomic DNA per reaction. The intra- and interassay coefficient of variation (CV) values ranged from 0.42-1.95%, demonstrating that the assay has good reproducibility. There was not any cross-reactivity to Streptococcus iniae or to other streptococcal/lactococcal fish pathogens, such as S. agalactiae and Lactococcus garvieae, indicating that the assay is highly specific to S. parauberis. The results of the real-time PCR assay corresponded well to those of conventional culture assays for S. parauberis from inoculated tissue homogenates (r = 0.957; P < 0.05). Hence, this sensitive and specific real-time PCR is a valuable tool for diagnostic quantitation of S. parauberis in clinical samples.
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Affiliation(s)
- T L Nguyen
- Department of Aquatic Life Medicine, College of Fisheries Science, Pukyong National University, Busan, South Korea
| | - Y J Lim
- Department of Aquatic Life Medicine, College of Fisheries Science, Pukyong National University, Busan, South Korea
| | - D-H Kim
- Department of Aquatic Life Medicine, College of Fisheries Science, Pukyong National University, Busan, South Korea
| | - B Austin
- Institute of Aquaculture, Pathfoot Building, University of Stirling, Stirling, UK
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Teixeira RC, Hermann-Avigliano C, Nguyen TL, Cantat-Moltrecht T, Raimond JM, Haroche S, Gleyzes S, Brune M. Microwaves Probe Dipole Blockade and van der Waals Forces in a Cold Rydberg Gas. Phys Rev Lett 2015; 115:013001. [PMID: 26182093 DOI: 10.1103/physrevlett.115.013001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Indexed: 06/04/2023]
Abstract
We show that microwave spectroscopy of a dense Rydberg gas trapped on a superconducting atom chip in the dipole blockade regime reveals directly the dipole-dipole many-body interaction energy spectrum. We use this method to investigate the expansion of the Rydberg cloud under the effect of repulsive van der Waals forces and the breakdown of the frozen gas approximation. This study opens a promising route for quantum simulation of many-body systems and quantum information transport in chains of strongly interacting Rydberg atoms.
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Affiliation(s)
- R Celistrino Teixeira
- Laboratoire Kastler Brossel, Collège de France, CNRS, ENS-PSL Research University, UPMC-Sorbonne Universités, 11 place Marcelin Berthelot, 75005 Paris, France
| | - C Hermann-Avigliano
- Laboratoire Kastler Brossel, Collège de France, CNRS, ENS-PSL Research University, UPMC-Sorbonne Universités, 11 place Marcelin Berthelot, 75005 Paris, France
| | - T L Nguyen
- Laboratoire Kastler Brossel, Collège de France, CNRS, ENS-PSL Research University, UPMC-Sorbonne Universités, 11 place Marcelin Berthelot, 75005 Paris, France
| | - T Cantat-Moltrecht
- Laboratoire Kastler Brossel, Collège de France, CNRS, ENS-PSL Research University, UPMC-Sorbonne Universités, 11 place Marcelin Berthelot, 75005 Paris, France
| | - J M Raimond
- Laboratoire Kastler Brossel, Collège de France, CNRS, ENS-PSL Research University, UPMC-Sorbonne Universités, 11 place Marcelin Berthelot, 75005 Paris, France
| | - S Haroche
- Laboratoire Kastler Brossel, Collège de France, CNRS, ENS-PSL Research University, UPMC-Sorbonne Universités, 11 place Marcelin Berthelot, 75005 Paris, France
| | - S Gleyzes
- Laboratoire Kastler Brossel, Collège de France, CNRS, ENS-PSL Research University, UPMC-Sorbonne Universités, 11 place Marcelin Berthelot, 75005 Paris, France
| | - M Brune
- Laboratoire Kastler Brossel, Collège de France, CNRS, ENS-PSL Research University, UPMC-Sorbonne Universités, 11 place Marcelin Berthelot, 75005 Paris, France
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Dongaonkar RM, Nguyen TL, Quick CM, Heaps CL, Hardy J, Laine GA, Wilson E, Stewart RH. Mesenteric lymphatic vessels adapt to mesenteric venous hypertension by becoming weaker pumps. Am J Physiol Regul Integr Comp Physiol 2014; 308:R391-9. [PMID: 25519727 DOI: 10.1152/ajpregu.00196.2014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Lymphangions, the segments of lymphatic vessels between two adjacent lymphatic valves, actively pump lymph. Acute changes in transmural pressure and lymph flow have profound effects on lymphatic pump function in vitro. Chronic changes in pressure and flow in vivo have also been reported to lead to significant changes in lymphangion function. Because changes in pressure and flow are both cause and effect of adaptive processes, characterizing adaptation requires a more fundamental analysis of lymphatic muscle properties. Therefore, the purpose of the present work was to use an intact lymphangion isovolumetric preparation to evaluate changes in mesenteric lymphatic muscle mechanical properties and the intracellular Ca(2+) in response to sustained mesenteric venous hypertension. Bovine mesenteric veins were surgically occluded to create mesenteric venous hypertension. Postnodal mesenteric lymphatic vessels from mesenteric venous hypertension (MVH; n = 6) and sham surgery (Sham; n = 6) animals were isolated and evaluated 3 days after the surgery. Spontaneously contracting MVH vessels generated end-systolic active tension and end-diastolic active tension lower than the Sham vessels. Furthermore, steady-state active tension and intracellular Ca(2+) concentration levels in response to KCl stimulation were also significantly lower in MVH vessels compared with those of the Sham vessels. There was no significant difference in passive tension in lymphatic vessels from the two groups. Taken together, these results suggest that following 3 days of mesenteric venous hypertension, postnodal mesenteric lymphatic vessels adapt to become weaker pumps with decreased cytosolic Ca(2+) concentration.
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Affiliation(s)
- R M Dongaonkar
- Michael E. DeBakey Institute, Texas A&M University, College Station, Texas
| | - T L Nguyen
- Michael E. DeBakey Institute, Texas A&M University, College Station, Texas
| | - C M Quick
- Michael E. DeBakey Institute, Texas A&M University, College Station, Texas;
| | - C L Heaps
- Michael E. DeBakey Institute, Texas A&M University, College Station, Texas
| | - J Hardy
- Large Animal Clinical Sciences, Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas; and
| | - G A Laine
- Michael E. DeBakey Institute, Texas A&M University, College Station, Texas
| | - E Wilson
- Department of Medical Physiology, Texas A&M Health Science Center, Texas A&M University, College Station, Texas
| | - R H Stewart
- Michael E. DeBakey Institute, Texas A&M University, College Station, Texas
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Yaghmour MA, Nguyen TL, Roubtsova TV, Hasey JK, Fichtner EJ, DeBuse C, Seybold SJ, Bostock RM. First Report of Geosmithia morbida on English Walnut and its Paradox Rootstock in California. Plant Dis 2014; 98:1441. [PMID: 30703976 DOI: 10.1094/pdis-06-14-0569-pdn] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Geosmithia morbida, the causal agent of thousand cankers disease (TCD), is vectored by the walnut twig beetle (WTB), Pityophthorus juglandis, causing decline in eastern black walnut, Juglans nigra (4), and canker development on many Juglans species (5). In the summer of 2012, a survey for TCD incidence in English walnut, J. regia, in orchards in California identified many trees with WTB activity and characteristic TCD symptoms. Both the J. regia scion and its Paradox hybrid rootstock (J. hindsii× J. regia) were affected. In some cases, trees exhibited bleeding on the bark surface from WTB entrance holes. Removal of the outer bark revealed cankers in the phloem around the WTB galleries. Two samples were taken from scions and three samples were collected from rootstocks of trees in orchards in northern California. Pieces (~3 to 4 mm2) of symptomatic tissue were placed in acidified potato dextrose agar (APDA), and the plates were incubated for 4 to 5 days at 30°C. Samples exhibiting fungal growth similar in morphology to G. morbida were transferred to PDA plates to obtain pure cultures and then processed to obtain single-spore cultures. Culture morphology for five single-spore isolates (Gm103, Gm104, Gm105, Gm107, and Gm108) was similar to that described by Kolařík et al. (4) for G. morbida. Conidiophores were penicillate and verrucose. Conidia were narrowly cylindrical, 5.2 ± 0.06 × 2.2 ± 0.04 μm (n = 50). Single-spore isolates were then grown in 1% yeast extract glucose liquid culture for 7 to 10 days. DNA was extracted and the ITS region was amplified, including the 5.8S region by using primers ITS1F/ITS4. Sequences were assembled and deposited in GenBank under accessions KJ664793 to KJ664797. Sequences were compared to those in GenBank; all sequences matched (99 to 100% identity) the ITS sequences of G. morbida strain CBS 124663. Pathogenicity tests were performed on 28-cm-long detached branches of J. regia. Four branches per isolate were inoculated with a 5-mm-diameter mycelial plug from a 2-week-old culture. Branches were incubated at room temperature (23 ± 2°C) in a humidified container for 3 weeks, and then canker lengths were measured. Pieces of the cankered area were placed in APDA and incubated as described above with G. morbida re-isolated from the cankers for all of the isolates, completing Koch's postulates. Average canker lengths ranged from 48.6 ± 4.3 to 72.1 ± 7.1 mm. Re-isolated G. morbida exhibited the same growth and reproductive structure morphology in culture on PDA as the original cultures. TCD in association with WTB has been observed in California English walnut orchards since 2008 (1,2,3). However, this is the first report for completion of Koch's postulates and morphological and molecular confirmation of G. morbida in J. regia and the Paradox rootstock, the predominant rootstock used in commercial orchards. TCD is a concern to the walnut industry in California with over 245,000 bearing acres reported in 2012. References: (1) M. Flint et al. CAPCA Adviser 8:36, 2010. (2) A. D. Graves et al. Walnut Twig Beetle and Thousand Cankers Disease: Field Identification Guide. UC-IPM website publication, http://www.ipm.ucdavis.edu/PDF/MISC/thousand_cankers_field_guide.pdf , 2009. (3) J. Hasey et al. (Abstr.) Phytopathology 100:S48, 2010. (4) M. Kolařík et al. Mycologia 103:325, 2011. (5) C. Utley et al. Plant Dis. 97:601, 2013.
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Affiliation(s)
- M A Yaghmour
- Department of Plant Pathology, University of California, Davis, CA 95616
| | - T L Nguyen
- Department of Plant Pathology, University of California, Davis, CA 95616
| | - T V Roubtsova
- Department of Plant Pathology, University of California, Davis, CA 95616
| | - J K Hasey
- University of California Cooperative Extension, Yuba City, CA 95991
| | - E J Fichtner
- University of California Cooperative Extension, Tulare, CA 93274
| | | | - S J Seybold
- Pacific Southwest Research Station, USDA Forest Service, Davis, CA 95618
| | - R M Bostock
- Department of Plant Pathology, University of California, Davis, CA 95616
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Dongaonkar RM, Nguyen TL, Quick CM, Hardy J, Laine GA, Wilson E, Stewart RH. Adaptation of mesenteric lymphatic vessels to prolonged changes in transmural pressure. Am J Physiol Heart Circ Physiol 2013; 305:H203-10. [PMID: 23666672 DOI: 10.1152/ajpheart.00677.2012] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [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] [Indexed: 12/13/2022]
Abstract
In vitro studies have revealed that acute increases in transmural pressure increase lymphatic vessel contractile function. However, adaptive responses to prolonged changes in transmural pressure in vivo have not been reported. Therefore, we developed a novel bovine mesenteric lymphatic partial constriction model to test the hypothesis that lymphatic vessels exposed to higher transmural pressures adapt functionally to become stronger pumps than vessels exposed to lower transmural pressures. Postnodal mesenteric lymphatic vessels were partially constricted for 3 days. On postoperative day 3, constricted vessels were isolated, and divided into upstream (UP) and downstream (DN) segment groups, and instrumented in an isolated bath. Although there were no differences between the passive diameters of the two groups, both diastolic diameter and systolic diameter were significantly larger in the UP group than in the DN group. The pump index of the UP group was also higher than that in the DN group. In conclusion, this is the first work to report how lymphatic vessels adapt to prolonged changes in transmural pressure in vivo. Our results suggest that vessel segments upstream of the constriction adapt to become both better fluid conduits and lymphatic pumps than downstream segments.
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Affiliation(s)
- R M Dongaonkar
- Michael E. DeBakey Institute, Texas A&M University, College Station, TX 77843-4466, USA
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Tran TNL, Nguyen TL, Luong MA, Khieu TQT. Can blood alcohol concentration of road traffic injury patients decrease after information education communication campaign in Vietnam. Inj Prev 2012. [DOI: 10.1136/injuryprev-2012-040590r.6] [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: 11/04/2022]
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21
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Tran TNL, Nguyen TL, Luong MA, Tran AT, Nguyen QT, Khieu TQT. Evaluation on first-aids' quality of volunteer network of pre-hospital trauma care system in Vietnam. Inj Prev 2012. [DOI: 10.1136/injuryprev-2012-040590b.2] [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: 11/04/2022]
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22
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Nguyen TL, Blanquet A, Staiger MP, Dias GJ, Woodfield TBF. On the role of surface roughness in the corrosion of pure magnesium in vitro. J Biomed Mater Res B Appl Biomater 2012; 100:1310-8. [PMID: 22566378 DOI: 10.1002/jbm.b.32697] [Citation(s) in RCA: 22] [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] [Received: 11/08/2011] [Revised: 01/29/2012] [Accepted: 02/12/2012] [Indexed: 11/08/2022]
Abstract
The relationship between surface roughness and degradation behavior in magnesium (Mg) biomaterials is still a controversial issue. This study aims to clarify the relationship between surface roughness and corrosion rate of pure Mg. Pure Mg samples with surface roughness values (Ra) of 0.59, 2.68, and 9.12 μm were cast using an indirect solid-free form fabrication method. The in vitro corrosion behavior was evaluated using hydrogen evolution, mass loss, potentiodynamic polarization, and electrochemical impedance spectroscopy. It was confirmed that surface roughness had a significant influence on the corrosion rate of pure Mg, with increasing roughness resulting in an accelerated corrosion rate. However, pitting corrosion was not observed, suggesting that surface roughness does not affect the pitting potential of Mg.
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Affiliation(s)
- T L Nguyen
- Department of Mechanical Engineering, University of Canterbury, Christchurch, New Zealand
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23
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Nakada C, Tsukamoto Y, Matsuura K, Nguyen TL, Hijiya N, Uchida T, Sato F, Mimata H, Seto M, Moriyama M. Abstract 131: Biological effect of miR-210 overexpression on renal carcinoma cells. Cancer Res 2011. [DOI: 10.1158/1538-7445.am2011-131] [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] [Indexed: 11/16/2022]
Abstract
Abstract
MiR-210 is significantly upregulated in clear cell renal cell carcinoma (CCC), but the mechanism and biological consequences of miR-210 upregulation are poorly understood. Here, we show that miR-210 is highly expressed in renal carcinoma cell lines and that its expression is clearly correlated with accumulation of hypoxia inducible factor 1α (HIF1α) under normoxia as well as hypoxia, suggesting that miR-210 upregulation in renal carcinoma cells is most likely due to accumulation of HIF1α. To reveal the effects of miR-210 upregulation, the miR-210 precursor was transfected into renal carcinoma cells. After transfection, the cells accumulated at G2/M phase of the cell cycle and their viability was decreased, suggesting that miR-210 overexpression may trigger an event that hinders normal cell division. Immunocytochemistry demonstrated a multipolar spindle accompanied by centrosome amplification in cells overexpressing miR-210. It has been reported that centrosome amplification induces chromosome mis-segregation, finally leading to chromosome instability and aneuploidy. Indeed, the proportion of aneuploid cells (>4n) was increased in miR-210 overexpressed cells. By using the TargetScan and PicTar algorithms, E2F3 was identified as one of the possible targets of miR-210, and was suppressed at the protein level by miR-210. Moreover, the proportion of aneuploid cells was increased in E2F3 siRNA transfected cells. On the basis of these results, we propose that miR-210 upregulation due to HIF1α accumulation may induce aneuploidy via E2F3 downregulation at least in part, and may play a role in tumorigenesis and/or progression of CCC.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 131. doi:10.1158/1538-7445.AM2011-131
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Nakada C, Tsukamoto Y, Matsuura K, Nguyen TL, Hijiya N, Uchida T, Sato F, Mimata H, Seto M, Moriyama M. Overexpression of miR-210, a downstream target of HIF1α, causes centrosome amplification in renal carcinoma cells. J Pathol 2011; 224:280-8. [PMID: 21465485 DOI: 10.1002/path.2860] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2010] [Revised: 12/16/2010] [Accepted: 01/12/2011] [Indexed: 12/14/2022]
Abstract
MiR-210 is significantly up-regulated in clear cell renal cell carcinoma (CCC), but the mechanism and biological consequences of miR-210 up-regulation are poorly understood. Here, we show that miR-210 is highly expressed in renal carcinoma cell lines and that its expression is clearly correlated with accumulation of hypoxia-inducible factor 1α (HIF1α) under normoxia as well as hypoxia, suggesting that miR-210 up-regulation in renal carcinoma cells is most likely due to accumulation of HIF1α. To reveal the effects of miR-210 up-regulation, the miR-210 precursor was transfected into renal carcinoma cells. After transfection, the cells accumulated at the G2/M phase of the cell cycle and their viability was decreased, suggesting that miR-210 overexpression may trigger an event that hinders normal cell division. Immunocytochemistry demonstrated a multipolar spindle accompanied by centrosome amplification in cells overexpressing miR-210. It has been reported that centrosome amplification induces chromosome mis-segregation, finally leading to chromosome instability and aneuploidy. Indeed, the proportion of aneuploid cells (>4n) was increased in miR-210 overexpressed cells. By using the TargetScan and PicTar algorithms, E2F3 was identified as one of the possible targets of miR-210 and was suppressed at the protein level by miR-210. Moreover, the proportion of aneuploid cells was increased in E2F3 siRNA transfected cells. On the basis of these results, we propose that miR-210 up-regulation due to HIF1α accumulation may induce aneuploidy via E2F3 down-regulation at least in part, and may play a role in tumourigenesis and/or progression of CCC.
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Affiliation(s)
- Chisato Nakada
- Department of Molecular Pathology, Faculty of Medicine, Oita University, Oita 879-5593, Japan
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Abstract
We propose, and quantify from first principles, two novel HO(x)-regenerating unimolecular reactions in isoprene oxidation, which are estimated to yield in pristine tropical forest conditions about 0.7 HO(2) and 0.03 OH radicals per isoprene oxidized; it is further argued that the photolabile coproduct of HO(2) can be a major source of OH, with a yield of the order of 1. The newly proposed chemistry could provide a rationalization for the unexpectedly high OH concentrations often observed in forested environments, such as over the Amazon forest in the recent Gabriel campaign.
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Affiliation(s)
- J Peeters
- Department of Chemistry, K.U. Leuven, Celestijnenlaan 200F, B-3001, Leuven, Belgium.
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Nguyen TL, Winterhalter R, Moortgat G, Kanawati B, Peeters J, Vereecken L. The gas-phase ozonolysis of β-caryophyllene (C15H24). Part II: A theoretical study. Phys Chem Chem Phys 2009; 11:4173-83. [PMID: 19458819 DOI: 10.1039/b817913a] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- T L Nguyen
- Department of Chemistry, K. U. Leuven, Celestijnenlaan 200F, B-3001, Leuven, Belgium
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Pham TB, Nguyen TH, Vu TQH, Nguyen TL, Malvy D. [Predictive factors of dengue shock syndrome at the children Hospital No. 1, Ho-chi-Minh City, Vietnam]. Bull Soc Pathol Exot 2007; 100:43-7. [PMID: 17402695] [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: 05/14/2023]
Abstract
The dengue shock syndrome (DSS) is primarily a complication of dengue haemorrhagic fever (DHF) among children in South East Asia. A case-control study was carried out at the children hospital no 1 (Ho-Chi-Minh City, Vietnam) in May-July 2005, to identify the predictive factors of the DSS among 1-15 year patients with DHE Forty consecutive admitted cases and forty controls were studied. The associated features of DSS were the 7-12 year age group and the re-infection by the dengue virus. The vaccination against the Japanese encephalitis B was not associated statistically significantly with the shock syndrome. The clinical predictors of DSS gathered an abdominal tenderness, an hepatomegaly, a lethargy, a cold extremity presentation. DSS associated laboratory features were a value of hematocrit a 50 % and a platelet cell count < or = 75,000/mm3.
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Affiliation(s)
- T B Pham
- EA 3677 et Centre Rene-Labusquiere (Médecine et hygiène tropicales), Université Victor-Segalen Bordeaux-II, 146 rue Leo-Saignat, 33076 Bordeaux, France.
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Kislov VV, Nguyen TL, Mebel AM, Lin SH, Smith SC. Photodissociation of benzene under collision-free conditions: an ab initio/Rice-Ramsperger-Kassel-Marcus study. J Chem Phys 2006; 120:7008-17. [PMID: 15267601 DOI: 10.1063/1.1676275] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The ab initio/Rice-Ramsperger-Kassel-Marcus (RRKM) approach has been applied to investigate the photodissociation mechanism of benzene at various wavelengths upon absorption of one or two UV photons followed by internal conversion into the ground electronic state. Reaction pathways leading to various decomposition products have been mapped out at the G2M level and then the RRKM and microcanonical variational transition state theories have been applied to compute rate constants for individual reaction steps. Relative product yields (branching ratios) for C(6)H(5)+H, C(6)H(4)+H(2), C(4)H(4)+C(2)H(2), C(4)H(2)+C(2)H(4), C(3)H(3)+C(3)H(3), C(5)H(3)+CH(3), and C(4)H(3)+C(2)H(3) have been calculated subsequently using both numerical integration of kinetic master equations and the steady-state approach. The results show that upon absorption of a 248 nm photon dissociation is too slow to be observable in molecular beam experiments. In photodissociation at 193 nm, the dominant dissociation channel is H atom elimination (99.6%) and the minor reaction channel is H(2) elimination, with the branching ratio of only 0.4%. The calculated lifetime of benzene at 193 nm is about 11 micros, in excellent agreement with the experimental value of 10 micros. At 157 nm, the H loss remains the dominant channel but its branching ratio decreases to 97.5%, while that for H(2) elimination increases to 2.1%. The other channels leading to C(3)H(3)+C(3)H(3), C(5)H(3)+CH(3), C(4)H(4)+C(2)H(2), and C(4)H(3)+C(2)H(3) play insignificant role but might be observed. For photodissociation upon absorption of two UV photons occurring through the neutral "hot" benzene mechanism excluding dissociative ionization, we predict that the C(6)H(5)+H channel should be less dominant, while the contribution of C(6)H(4)+H(2) and the C(3)H(3)+C(3)H(3), CH(3)+C(5)H(3), and C(4)H(3)+C(2)H(3) radical channels should significantly increase.
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Affiliation(s)
- V V Kislov
- Institute of Atomic and Molecular Sciences, Academia Sinica, P.O. Box 23-166, Taipei 10764, Taiwan
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Abstract
Although pore formation by protective antigen (PA) is critical to cell intoxication by anthrax toxin (AT), the structure of the pore form of PA (the PA63 pore) has not been determined. Hence, in this study, the PA63 pore was modeled using the X-ray structures of monomeric PA and heptameric alpha-hemolysin (alpha-HL) as templates. The PA63 pore model consists of two weakly associated domains, namely the cap and stem domains. The ring-like cap domain has a length of 80 A and an outside diameter of 120 A, while the cylinder-like stem domain has a length of 100 A and outside diameter of approximately 28 A. This provides the PA63 pore model with a length of 180 A. Based on experimental results, the channel in the PA63 pore model was built to have a minimum diameter of ~12 A, depending on side chain conformations. Because of its large size and structural complexity, the all-atom model of the PA63 pore is the end-stage construction of four separate modeling projects described herein. The final model is consistent with published experimental results, including mutational analysis and channel conductance experiments. In addition, the model was energetically and hydropathically refined to optimize molecular packing within the protomers and at the protomer-protomer interfaces. By providing atomic detail to biochemical and biophysical data, the PA63 pore model may afford new insights into the binding mode of PA on the membrane surface, the prepore-pore transition, and the mechanism of cell entry by anthrax toxin.
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Affiliation(s)
- T L Nguyen
- Developmental Therapeutics Program, National Cancer Institute, 378 Ware Drive, Frederick, MD 21702, USA.
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De Smedt F, Bui XV, Nguyen TL, Peeters J, Vereecken L. Theoretical and Experimental Study of the Product Branching in the Reaction of Acetic Acid with OH Radicals. J Phys Chem A 2005; 109:2401-9. [PMID: 16839011 DOI: 10.1021/jp044679v] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The product distribution of the reaction of acetic acid, CH(3)COOH, with hydroxyl radicals, OH, was studied experimentally and theoretically. Mass-spectrometric measurements at 290 K and 2 Torr of He of the CO(2) yield versus the loss of acetic acid yielded a branching fraction of 64 +/- 14% for the abstraction of the acidic hydrogen as follows: CH(3)COOH + OH --> CH(3)COO + H(2)O --> CH(3) + CO(2) + H(2)O. A quantum chemical and theoretical kinetic analysis showed that the abstraction of the acidic hydrogen is enhanced relative to the abstraction of -CH(3) hydrogens because of the formation of a strong pre-reactive H-bonded complex, where the H-bonds are retained in the H-abstraction transition state. The potential energy surface of the reaction is explored in detail, and the reaction products of the individual channels are identified. The theoretical product branching is found to be critically dependent on the energetic and rovibrational differences between the H-abstraction transition states.
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Affiliation(s)
- F De Smedt
- Department of Chemistry, University of Leuven, Celestijnenlaan 200F, 3001 Leuven, Belgium
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31
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Kaiser RI, Le TN, Nguyen TL, Mebel AM, Balucani N, Lee YT, Stahl F, Schleyer PR, Schaefer HF. A combined crossed molecular beam and ab initio investigation of C2 and C3 elementary reactions with unsaturated hydrocarbons--pathways to hydrogen deficient hydrocarbon radicals in combustion flames. Faraday Discuss 2002:51-66; discussion 121-43. [PMID: 11878006 DOI: 10.1039/b101967h] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.8] [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
Crossed molecular beam experiments on dicarbon and tricarbon reactions with unsaturated hydrocarbons acetylene, methylacetylene, and ethylene were performed to investigate the dynamics of channels leading to hydrogen-deficient hydrocarbon radicals. In the light of the results of new ab initio calculations, the experimental data suggest that these reactions are governed by an initial addition of C2/C3 to the pi molecular orbitals forming highly unsaturated cyclic structures. These intermediates are connected via various transition states and are suggested to ring open to chain isomers which decompose predominantly by displacement of atomic hydrogen, forming C4H, C5H, HCCCCCH2, HCCCCCCH3, H2CCCCH and H2CCCCCH. The C2(1 sigma g+) + C2H4 reaction has no entrance barrier and the channel leading to the H2CCCCH product is strongly exothermic. This is in strong contrast with the C3(1 sigma g+) + C2H4 reaction as this is characterized by a 26.4 kJ mol-1 threshold to form a HCCCCCH2 isomer. Analogous to the behavior with ethylene, preliminary results on the reactions of C2 and C3 with C2H2 and CH3CCH showed the H-displacement channels of these systems to share many similarities such as the absence/presence of an entrance barrier and the reaction mechanism. The explicit identification of the C2/C3 vs. hydrogen displacement demonstrates that hydrogen-deficient hydrocarbon radicals can be formed easily in environments like those of combustion processes. Our work is a first step towards a systematic database of the intermediates and the reaction products which are involved in this important class of reactions. These findings should be included in future models of PAH and soot formation in combustion flames.
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Affiliation(s)
- R I Kaiser
- Department of Chemistry, University of York, York, UK YO10 5DD
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32
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Abstract
Ureas characteristically form one-dimensional hydrogen-bonded alpha-networks with a repeat distance of about 4.60 A. Oxamides form similar alpha-networks with a longer 5.05 A repeat distance. The urea of glycine and the oxamide of glycine were each cocrystallized with a series of four bipyridines, including two urea derivatives and two oxamide derivatives. This series of eight cocrystals was studied by X-ray diffraction in order to see what would happen when molecules that would normally form alpha-networks with incommensurate distances were forced into the same crystal. The two all-urea crystals and the two all-oxamide crystals contained the expected alpha-networks with repeat distances in accordance with normal urea or oxamide values. Four of the crystals were mixed, containing both oxamide and urea molecules. Three consisted of two-dimensional beta-networks with alternating parallel urea and oxamide subnetworks. The repeat distances averaged 4.87 A, a value close to the value expected for oxamides, but shorter than any previously observed examples. In the fourth mixed crystal, the urea alpha-network formed with a normal urea repeat distance, but the oxamide network did not form, the oxamide adopting an unusual molecular conformation that maximizes intramolecular hydrogen bonds instead.
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Affiliation(s)
- T L Nguyen
- Department of Chemistry, State University of New York, Stony Brook, NY 11794, USA
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Mazure NM, Nguyen TL, Danan JL. Severe hypoxia specifically downregulates hepatocyte nuclear factor-4 gene expression in HepG2 human hepatoma cells. Tumour Biol 2001; 22:310-7. [PMID: 11553861 DOI: 10.1159/000050632] [Citation(s) in RCA: 16] [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: 11/19/2022] Open
Abstract
The liver is one of the organs in which hypoxia helps to regulate gene expression under normal physiological conditions and in diseases such as cirrhosis and cancer. We postulated that the expression/activity of some of the 'liver-enriched' transcription factors, which control liver-specific genes, was sensitive to hypoxia. We tested hepatocyte nuclear factor-1 (HNF-1), HNF-3 and HNF-4, which play key roles in differentiation, development and hepatic gene expression, using HepG2 human hepatoma cells cultured under hypoxic conditions. Severe hypoxia/anoxia downregulated HNF-4 DNA-binding activity while DNA-binding activity of HNF-1 and HNF-3 remained unaffected. These hypoxic conditions also strongly and specifically decreased cell contents of HNF-4 protein, indicating that the decrease in HNF-4 DNA-binding activity was due to the lower amount of protein and not to decreased DNA-binding affinity. Northern analysis indicated that the expression of the hnf-4 gene was also downregulated in HepG2 cells cultured under hypoxic conditions. These results provide evidence that hypoxic stress triggers a cascade of events that inhibits the transactivation potential of HNF-4 in HepG2 cells. This step may be crucial in modulating the expression of a subset of liver genes that are targets for this nuclear receptor. This relationship provides a new route for the investigation of the effects of hypoxia on the liver cell.
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Affiliation(s)
- N M Mazure
- Centre de Recherche sur l'Endocrinologie Moléculaire et le Développement CNRS-UPR 9078, Meudon-Bellevue, France
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Wu CK, Hu B, Rose JP, Liu ZJ, Nguyen TL, Zheng C, Breslow E, Wang BC. Structures of an unliganded neurophysin and its vasopressin complex: implications for binding and allosteric mechanisms. Protein Sci 2001; 10:1869-80. [PMID: 11514677 PMCID: PMC2253203 DOI: 10.1110/ps.10601] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [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: 01/07/2023]
Abstract
The structures of des 1-6 bovine neurophysin-II in the unliganded state and as its complex with lysine vasopressin were determined crystallographically at resolutions of 2.4 A and 2.3 A, respectively. The structure of the protein component of the vasopressin complex was, with some local differences, similar to that determined earlier of the full-length protein complexed with oxytocin, but relatively large differences, probably intrinsic to the hormones, were observed between the structures of bound oxytocin and bound vasopressin at Gln 4. The structure of the unliganded protein is the first structure of an unliganded neurophysin. Comparison with the liganded state indicated significant binding-induced conformational changes that were the largest in the loop region comprising residues 50-58 and in the 7-10 region. A subtle binding-induced tightening of the subunit interface of the dimer also was shown, consistent with a role for interface changes in neurophysin allosteric mechanism, but one that is probably not predominant. Interface changes are suggested to be communicated from the binding site through the strands of beta-sheet that connect these two regions, in part with mediation by Gly 23. Comparison of unliganded and liganded states additionally reveals that the binding site for the hormone alpha-amino group is largely preformed and accessible in the unliganded state, suggesting that it represents the initial site of hormone protein recognition. The potential molecular basis for its thermodynamic contribution to binding is discussed.
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Affiliation(s)
- C K Wu
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602, USA
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35
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Eubanks S, Nguyen TL, Deeb R, Villafania A, Alfadhli A, Breslow E. Effects of diabetes insipidus mutations on neurophysin folding and function. J Biol Chem 2001; 276:29671-80. [PMID: 11395505 DOI: 10.1074/jbc.m103477200] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [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: 11/06/2022] Open
Abstract
Mechanisms underlying the pathogenicity of diabetes insipidus mutations were probed by studying their effects on the properties of bovine oxytocin-related neurophysin. The mutations G17V, DeltaE47, G57S, G57R, and C67STOP were each shown to have structural consequences that would diminish the conformational stability and folding efficiency of the precursors in which they were incorporated, and factors contributing to the origins of these property changes were identified. Effects of the mutations on dimerization of the folded proteins were similarly analyzed. The projected relative impact of the above mutations on precursor folding properties qualitatively parallels the reported relative severity of their effects on the biological handling of the human vasopressin precursor, but quantitative differences between thermodynamic effects and biological impact are noted and explored. The sole mutation for which no clear thermodynamic basis was found for its pathogenicity was 87STOP, suggesting that the region of the precursor deleted by this mutation plays a role in targeting independent from effects on folding, or participates in stabilizing interactions unique to the human vasopressin precursor.
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Affiliation(s)
- S Eubanks
- Department of Biochemistry, Weill Medical College of Cornell University, New York, New York 10021, USA
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Nguyen VM, Nguyen VT, Huynh PL, Dang DT, Nguyen TH, Phan VT, Nguyen TL, Le TL, Ivanoff B, Gentsch JR, Glass RI. The epidemiology and disease burden of rotavirus in Vietnam: sentinel surveillance at 6 hospitals. J Infect Dis 2001; 183:1707-12. [PMID: 11372022 DOI: 10.1086/320733] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.5] [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: 01/16/2001] [Revised: 03/21/2001] [Indexed: 11/04/2022] Open
Abstract
The disease burden of rotavirus diarrhea in Vietnam was assessed by surveillance of children <5 years old who were hospitalized for diarrhea at 3 centers in the north and 3 centers in the south. Rotavirus was identified in 56% (range, 47%-60%) of the 5768 patients surveyed between July 1998 and June 2000. G-typing of the first 224 strains indicated that only 2% were non-typeable, 9% were in mixed infections, and the remainder were of the common serotypes G1, G2, G3, G4, and G9. In Vietnam, diarrhea accounts for 9880 deaths per year, which is approximately 15% of all deaths among children <5 years old, or 6.5 deaths per 1000 children. If even 50% of these diarrhea-related deaths in Vietnam were due to rotavirus, the number would represent 4%-8% of all deaths among children <5 years old, 2700-5400 rotavirus-related deaths per year, and 1 death per 280-560 children during the first 5 years of life. Thus, the disease burden of rotavirus in Vietnam is substantial, and programs to encourage the use of oral rehydration should be encouraged while efforts to develop vaccines continue.
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Affiliation(s)
- V M Nguyen
- Poliomyelitis Vaccine Research and Production Center, Hanoi, Vietnam.
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Eubanks S, Nguyen TL, Peyton D, Breslow E. Modulation of dimerization, binding, stability, and folding by mutation of the neurophysin subunit interface. Biochemistry 2000; 39:8085-94. [PMID: 10891091 DOI: 10.1021/bi0001527] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [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: 11/28/2022]
Abstract
Bovine neurophysins, which have typically served as the paradigm for neurophysin behavior, are metastable in their disulfide-paired folded state and require ligand stabilization for efficient folding from the reduced state. Studies of unliganded porcine neurophysin (oxytocin-associated class) demonstrated that its dimerization constant is more than 90-fold greater than that of the corresponding bovine protein at neutral pH and showed that the increased dimerization constant is accompanied by an increase in stability sufficient to allow efficient folding of the reduced protein in the absence of ligand peptide. Using site-specific mutagenesis of the bovine protein and expression in Escherichia coli, the functional differences between the bovine and porcine proteins were shown to be attributable solely to two subunit interface mutations in the porcine protein, His to Arg at position 80 and Glu to Phe at position 81. Mutation of His-80 alone to Arg had a relatively small impact on dimerization, while mutation to either Glu or Asp markedly reduced dimerization in the unliganded state, albeit with apparent retention of the positive linkage between dimerization and binding. Comparison of the peptide-binding constants of the different mutants additionally indicated that substitution of His-80 led to modifications in binding affinity and specificity that were independent of effects on dimerization. The results demonstrate the importance of the carboxyl domain segment of the subunit interface in modulating neurophysin properties and suggest a specific contribution of the energetics of ligand-induced conformational change in this region to the overall thermodynamics of binding. The potential utility to future studies of the self-folding and monomeric mutants generated by altering the interface is noted.
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Affiliation(s)
- S Eubanks
- Department of Biochemistry, The Joan and Sanford I. Weill Medical College of Cornell University, 1300 York Avenue, New York, New York 10021, USA
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38
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Hober D, Nguyen TL, Shen L, Ha DQ, Huong VT, Benyoucef S, Nguyen TH, Bui TM, Loan HK, Le BL, Bouzidi A, De Groote D, Drouet MT, Deubel V, Wattré P. Tumor necrosis factor alpha levels in plasma and whole-blood culture in dengue-infected patients: relationship between virus detection and pre-existing specific antibodies. J Med Virol 1998; 54:210-8. [PMID: 9515771 DOI: 10.1002/(sici)1096-9071(199803)54:3<210::aid-jmv12>3.0.co;2-l] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [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: 02/06/2023]
Abstract
The pathogenesis of dengue hemorrhagic fever (DHF) is not well known, but the role of host factors has been suggested. The level of immunoreactive circulating and cell-generated tumor necrosis factor alpha (TNF alpha) was studied in 35 patients with DHF; its relationship with virus isolation and/or genome detection by reverse transcription polymerase chain reaction (RT-PCR) and specific antibodies were detected by hemagglutination inhibition (HI). Large variation of TNF alpha plasma levels was obtained in dengue-infected patients at the same stage of the disease and at the same day after infection. Most of the patients (14 out of 17 patients) who displayed augmented spontaneous in vitro production of TNF alpha by heparinized whole-blood culture compared with controls also had elevated levels of TNF alpha in the plasma. The TNF alpha values in lipopolysaccharide and phytohemagglutinin heparinized whole-blood cultures were not higher in patients than in controls, but low TNF alpha levels were obtained in three out of 30 patients. An inverse correlation was observed between spontaneous in vitro TNF alpha production and viral replication, which raises the issue of the antiviral effect of TNF alpha in dengue infection. The results do not support the hypothesis of the role of antibody-dependent enhancement giving rise to increased viremic titers and production of TNF alpha in patients. The present study demonstrates the activation of the TNF alpha-producing cells in dengue-infected patients and suggests further investigation to define the mechanism and the role of TNF alpha in the pathogenesis of dengue virus infection.
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Affiliation(s)
- D Hober
- Laboratoire de Virologie, CHU, Lille, France
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39
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Qi XL, Nguyen TL, Andries L, Sys SU, Rouleau JL. Vascular endothelial dysfunction contributes to myocardial depression in ischemia-reperfusion in the rat. Can J Physiol Pharmacol 1998; 76:35-45. [PMID: 9564547] [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: 02/07/2023]
Abstract
Endocardial and vascular myocardial capillary endothelium has been shown to modulate the contractile characteristics of myocardium by altering myofibrillar affinity for calcium. Although the release of endothelial-derived substances that modify myocardial contractility has been shown to be altered in certain physiologic and pathologic situations, until now no study has evaluated whether the direct modulatory effects of endothelium on its subjacent myocardium were altered in pathologic situations and contributed to loss of contractile function. This study was designed to evaluate whether the direct contractile modulatory effects of endocardial and (or) vascular endothelium were altered and whether these alterations contributed to contractile dysfunction in a model of ischemia-reperfusion. Sixty-two perfused rat hearts as Langendorff preparations were randomized to no intervention, intracoronary Triton X100 injection (to render vascular endothelium dysfunctional), ischemia (30 min)-reperfusion (20 min), and ischemia-reperfusion followed by intracoronary Triton X100 injection. Coronary endothelial-dependent vascular reactivity and vascular smooth muscle reactivity were assessed by serotonin and sodium nitroprusside, respectively. Myocardial damage was assessed by coronary effluent creatine phosphokinase and by morphologic studies. Papillary muscles were then excised and contractile characteristics evaluated at varying extracellular calcium concentration prior to and after endocardial endothelial removal with Triton X100. All three interventions eliminated all coronary vascular response to serotonin but did not modify response to nitroprusside. Creatine phosphokinase values rose only in hearts with ischemia-reperfusion, and only minor morphologic changes occurred, mostly in hearts with ischemia-reperfusion. Papillary muscles from hearts with intracoronary Triton X100 injection had lower contractile indices compared with normal controls (total tension 4.0 vs. 4.6 g/mm2, p < 0.01) and an abbreviation of contraction duration. Increasing extracellular calcium concentration from to 0.7 to 3.25 mM eliminated these differences. Similar but more marked decreases in contractile indices and twitch duration were noted in the two ischemia-reperfusion groups, but consistent with some myocardial damage being present, increasing extracellular calcium concentration to 3.25 or 7 mM did not fully eliminate these differences. In both ischemia-reperfusion groups and the intracoronary Triton X100 group, the relative increase in total tension with increasing extracellular calcium concentrations was similar (35 to 38%) and greater than that of the control group (25%), consistent with dysfunction of vascular endothelium contributing to myocardial dysfunction in the three intervention groups. Endocardial endothelial removal had a similar effect in all four groups, suggesting that dysfunction of endocardial endothelium does not play a role in this model. We conclude that vascular but not endocardial endothelial dysfunction contributes to the myocardial dysfunction that occurs during ischemia-reperfusion injury.
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MESH Headings
- Animals
- Calcium/metabolism
- Creatine Kinase/blood
- Endocardium/drug effects
- Endocardium/pathology
- Endocardium/physiopathology
- Endothelium, Vascular/pathology
- Endothelium, Vascular/physiopathology
- In Vitro Techniques
- Microscopy, Confocal
- Muscle Contraction/drug effects
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/pathology
- Muscle, Smooth, Vascular/physiopathology
- Myocardial Contraction/drug effects
- Myocardial Reperfusion Injury/pathology
- Myocardial Reperfusion Injury/physiopathology
- Myocardium/metabolism
- Myocardium/pathology
- Octoxynol/pharmacology
- Papillary Muscles/drug effects
- Papillary Muscles/metabolism
- Rats
- Rats, Wistar
- Vasodilation/drug effects
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Affiliation(s)
- X L Qi
- Department of Medicine, Institut de cardiologie de Montréal, QC, Canada
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40
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Qi XL, Nguyen TL, Andries L, Sys SU, Rouleau JL. Vascular endothelial dysfunction contributes to myocardial depression in ischemia-reperfusion in the rat. Can J Physiol Pharmacol 1998. [DOI: 10.1139/y97-185] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Endocardial and vascular myocardial capillary endothelium has been shown to modulate the contractile characteristics of myocardium by altering myofibrillar affinity for calcium. Although the release of endothelial-derived substances that modify myocardial contractility has been shown to be altered in certain physiologic and pathologic situations, until now no study has evaluated whether the direct modulatory effects of endothelium on its subjacent myocardium were altered in pathologic situations and contributed to loss of contractile function. This study was designed to evaluate whether the direct contractile modulatory effects of endocardial and (or) vascular endothelium were altered and whether these alterations contributed to contractile dysfunction in a model of ischemia-reperfusion. Sixty-two perfused rat hearts as Langendorff preparations were randomized to no intervention, intracoronary Triton X100 injection (to render vascular endothelium dysfunctional), ischemia (30 min) - reperfusion (20 min), and ischemia-reperfusion followed by intracoronary Triton X100 injection. Coronary endothelial-dependent vascular reactivity and vascular smooth muscle reactivity were assessed by serotonin and sodium nitroprusside, respectively. Myocardial damage was assessed by coronary effluent creatine phosphokinase and by morphologic studies. Papillary muscles were then excised and contractile characteristics evaluated at varying extracellular calcium concentration prior to and after endocardial endothelial removal with Triton X100. All three interventions eliminated all coronary vascular response to serotonin but did not modify response to nitroprusside. Creatine phosphokinase values rose only in hearts with ischemia-reperfusion, and only minor morphologic changes occurred, mostly in hearts with ischemia-reperfusion. Papillary muscles from hearts with intracoronary Triton X100 injection had lower contractile indices compared with normal controls (total tension 4.0 vs. 4.6 g/mm2, p << 0.01) and an abbreviation of contraction duration. Increasing extracellular calcium concentration from 0.7 to 3.25 mM eliminated these differences. Similar but more marked decreases in contractile indices and twitch duration were noted in the two ischemia-reperfusion groups, but consistent with some myocardial damage being present, increasing extracellular calcium concentration to 3.25 or 7 mM did not fully eliminate these differences. In both ischemia-reperfusion groups and the intracoronary Triton X100 group, the relative increase in total tension with increasing extracellular calcium concentrations was similar (35 to 38%) and greater than that of the control group (25%), consistent with dysfunction of vascular endothelium contributing to myocardial dysfunction in the three intervention groups. Endocardial endothelial removal had a similar effect in all four groups, suggesting that dysfunction of endocardial endothelium does not play a role in this model. We conclude that vascular but not endocardial endothelial dysfunction contributes to the myocardial dysfunction that occurs during ischemia-reperfusion injury.Key words: endocardial endothelium, vascular endothelium, ischemia reperfusion, myocardial contractility.
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Abstract
The impact of dengue haemorrhagic fever (DHF) on liver function was studied by measuring serum transaminase levels on 45 patients with DHF confirmed by virus isolation and serodiagnosis in 1995. Abnormal levels of AST and ALT were observed in 97.7 and 37.3% of the patients, respectively. The fact that the level of AST was higher than that of ALT and that the elevation of transaminases was mild to moderate in most cases (< 5-fold greater than the normal upper limit for AST and ALT) showed that liver involvement was also mild to moderate in most cases of DHF. The results of transaminases did not differ significantly between cases with and without hepatitis B or hepatitis C virus infection, nor between primary and secondary cases of infection, but a significantly higher elevation of AST and ALT was observed in DHF patients with gastrointestinal haemorrhage. Two patients with dengue encephalopathy (in 1992) and one patient with dengue encephalopathy who died of massive gastrointestinal haemorrhage (in 1995) had unusually high transaminase levels as a sign of acute liver failure. It is concluded that DHF may cause mild to moderate liver dysfunction in most cases; only some patients may suffer from acute liver failure leading to encephalopathy and death.
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Affiliation(s)
- T L Nguyen
- Dengue Hemorrhagic Fever Department, Children's Hospital no. 1, Ho Chi Minh City, Vietnam
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Nguyen TC, Solomon T, Mai XT, Nguyen TL, Nguyen TT, Wain J, To SD, Smith MD, Day NP, Le TP, Parry C, White NJ. Short courses of ofloxacin for the treatment of enteric fever. Trans R Soc Trop Med Hyg 1997; 91:347-9. [PMID: 9231214 DOI: 10.1016/s0035-9203(97)90102-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [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: 02/04/2023] Open
Abstract
Typhoid fever continues to be a major public health problem in tropical countries, exacerbated in recent years by the spread of multi-drug resistant strains of Salmonella typhi. Short treatment courses of fluoroquinolones are effective, and have the advantage of reduced cost and increased compliance, but the optimal length of treatment is unknown. In an open, randomized comparison, 107 adults with uncomplicated enteric fever (95 of whom had positive blood cultures for S. typhi and 5 for S. paratyphi) were treated with oral ofloxacin, 15 mg/kg/d for 2 d or 10 mg/kg/d for 3 d. Mean fever clearance times were the same in the 2 treatment groups (97 h). There were 7 treatment failures, one in the 2 d group and 6 in the 3 d group (P = 0.07). Three of the 5 patients infected with nalidixic acid resistant strains of S. typhi had treatment failures, compared with 4 of 90 with nalidixic acid sensitive isolates (P < 0.0001; relative risk 13.5, 95% confidence interval 4.1-43%). Treatment with ofloxacin for 2 or 3 d is equally effective in adults with uncomplicated enteric fever caused by nalidixic acid sensitive strains of S. typhi. The epidemiology and management of nalidixic acid resistent typhoid needs further investigation.
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Affiliation(s)
- T C Nguyen
- Centre for Tropical Diseases, Cho Quan Hospital, Ho Chi Minh City, Viet Nam
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43
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Yoshida H, Li J, Yoneyama T, Yoshii K, Shimizu H, Nguyen TH, Toda K, Nguyen TL, Phan VT, Miyamura T, Hagiwara A. Two major strains of type 1 wild poliovirus circulating in Indochina. J Infect Dis 1997; 175:1233-7. [PMID: 9129093 DOI: 10.1086/593677] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [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: 02/04/2023] Open
Abstract
Two hundred ninety-four isolates from 329 patients with acute flaccid paralysis in Cambodia and Vietnam during 1992-1995 were identified as type 1 wild polioviruses. Among these isolates, 85 were selected as geographic representatives and were examined by determining the nucleotide sequences of their genome in the VP1 region. The phylogenic analysis revealed that all of the isolates examined were classified into groups A and B. Isolates belonging to group A had been found only in northern Vietnam until 1993 but not in 1994 and 1995. Group B isolates were located in both northern and southern Vietnam and Cambodia. In 1994 and 1995, however, only group B isolates were found in the Mekong Delta area in southern Vietnam and Cambodia. Isolates of groups A and B were genetically different from strains previously isolated in other Asian countries. One of the two indigenous wild polioviruses still remains to be eliminated in this area.
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Affiliation(s)
- H Yoshida
- Department of Virology II, National Institute of Health, Tokyo, Japan
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44
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Nguyen TL, Valayer J. [Congenital dilatation of the common bile duct in children. Study of a series of 52 cases]. Presse Med 1994; 23:1565-8. [PMID: 7824491] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
OBJECTIVE The aim of this study was to evaluate results at long-term follow-up of patients suffering from congenital dilatation of the bile duct according to the type of operative procedure. METHOD A retrospective study of 52 patients who were operated on during a 25-year period was carried out. Of 52 patients, 43 (83%) were female and 9 (17%) were male, with a ratio of 4.8/1. In six cases, the diagnosis was made antenatally by ultrasonography. Transhepatic cholangiography showed an extrahepatic dilatation in 25 cases (48%) and a combined extra and intrahepatic dilatation in 27 cases (52%). A common bilio-pancreatic channel was found in 25 patients. Mean age at the time of operation was 4.2 years. Operative procedures included: cyst excision and hepaticojejunostomy in 47 cases, cystojejunostomy or cystoduodenostomy in 4 cases and cystostomy in one case. There were two postoperative deaths. RESULTS Long-term follow-up was established in 43 of 50 survivors (80%). One patient was reoperated because of portal hypertension. Cholangitis developed in 11 patients: 2/2 patients who had undergone in internal drainage and 9/41 patients who had undergone a cyst excision with hepaticojejunostomy. In patients with cyst excision, cholangitis developed twice as frequently in those with associated intrahepatic dilatation. Two of 11 children with recurrent cholangitis died following sepsis, and three others were reoperated because of intrahepatic bile duct stones, one of these 15 years later. CONCLUSION A total excision of the extrahepatic biliary tract, followed by hepaticojejunostomy is considered as a treatment of choice. The site of the biliary anastomosis should be adapted to the type of dilatation of intrahepatic bile duct in the case of a combined extra and intrahepatic dilatation.
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Affiliation(s)
- T L Nguyen
- Service de Chirurgie pédiatrique, Hôpital de Bicêtre, Le Kremlin-Bicêtre
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45
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Férézou J, Nguyen TL, Leray C, Hajri T, Frey A, Cabaret Y, Courtieu J, Lutton C, Bach AC. Lipid composition and structure of commercial parenteral emulsions. Biochim Biophys Acta 1994; 1213:149-58. [PMID: 8025125 DOI: 10.1016/0005-2760(94)90021-3] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
In order to study the influence of the phospholipid/triacylglycerol (PL/TG) ratio of parenteral emulsions on the distribution and the physico-chemical properties of their fat particles, commercial 10, 20 or 30% fat formulas were fractionated by centrifugation into an upper lipid cake (resuspended in aqueous glycerol) and a subnatant or mesophase, from which a PL-rich subfraction (d = 1.010-1.030 g/l) was purified by density gradient ultracentrifugation. Chemical and 31P-NMR analyses of these fractions indicated that at least two types of fat particles coexist in parenteral emulsions: (i) TG-rich particles (mean diameter: 330, 400, 470 nm in the 10, 20, 30% emulsion) which contain practically all the TG and esterified phytosterols of native emulsions, but only a fraction of their PL, unesterified cholesterol and phytosterols, and other minor lipids; (ii) PL-bilayer particles or liposomes (mean diameter: 80-100 nm) which are constituted with the remaining PL and relatively very small amounts of TG and other lipids. The higher the oil content of the emulsion, the lower the amount of these PL-rich particles, which represent the major particle population of the mesophase. Indeed, minute amounts of TG-rich particles (probably the smallest ones) are also present in the mesophase, even in the PL-rich subfraction which contains the bulk of liposomal PL. Since the PL-rich particles of the infused emulsion generate lipoprotein X-like particles, only the large TG-rich particles can be considered as true chylomicron counterparts.
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Affiliation(s)
- J Férézou
- Physiologie de la Nutrition, Université Paris-Sud, Orsay, France
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Brasseur N, Nguyen TL, Langlois R, Ouellet R, Marengo S, Houde D, van Lier JE. Synthesis and photodynamic activities of silicon 2,3-naphthalocyanine derivatives. J Med Chem 1994; 37:415-20. [PMID: 8308868 DOI: 10.1021/jm00029a014] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.0] [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]
Abstract
Bis(tert-butyldimethylsiloxy)- (7), bis(dimethylthexylsiloxy)- (8), bis(tri-n-hexylsiloxy)- (9), and bis(dimethyloctadecylsiloxy)silicon 2,3-naphthalocyanines (10) were prepared via substitution of the bis(hydroxy) precursor with the corresponding chlorosilane ligands and characterized by spectroscopic and combustion analyses. They show strong absorption around 780 nm where tissues exhibit optimal transparency. Compounds 7-10 are capable of producing singlet oxygen. They are relatively photostable although less stable than the analogous phthalocyanine, i.e., the bis-(dimethylthexylsiloxy)silicon phthalocyanine (12). They were evaluated as potential photosensitizers for the photodynamic therapy (PDT) of cancer in vitro against V-79 cells and in vivo against the EMT-6 tumor in Balb/c mice. In vitro all four dyes showed limited phototoxicity combined with substantial dark toxicity. Surprisingly, in vivo (i.v., 0.1 mumol/kg, 24 h prior to the photoirradiation of the tumor with 780-nm light, 190 mW/cm2, 400 J/cm2) all dyes induced tumor regression in at least 50% of mice whereas compound 8 gave a complete tumor response in 80% of mice without apparent systemic toxicity at doses as high as 10 mumol/kg. At 24 h postinjection, compound 8 showed a favorable tumor to muscle ratio of 7, assuring minimal damage to the healthy tissue surrounding the tumor during PDT. Our data confirm the potential of silicon naphthalocyanines as far-red-shifted photosensitizers for the PDT of cancer and indicate the importance of the selection of the two axial silicon ligands for optimal photodynamic efficacy.
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Affiliation(s)
- N Brasseur
- MRC Group in the Radiation Sciences, Faculty of Medicine, University of Sherbrooke, Québec, Canada
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Shcherbakov AM, Nguyen TL, Chin KA, Chan KT, Rabinovich SA, Nguyen VD, Chan VF, Nguyen TL, Vu TT, Padelt H. [The clinical efficacy of and tolerance for lariam (mefloquine) in tropical malaria in the south of the Socialist Republic of Vietnam]. Med Parazitol (Mosk) 1990:57-9. [PMID: 2266908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The study was performed in the area of distribution of tropical malaria resistant to 4-aminoquinolines (Vietnam) on 30 patients receiving lariam (mefloquine). The results were compared to the standard therapy with quinine and fansidar. They indicate a high efficacy of and a good tolerance to the drug tested. The use of lariam leads to a more rapid (as compared to the standard treatment) elimination of parasitemia and complete eradication of the disease relapses. The findings make it possible to recommend lariam for the prevention and treatment of tropical malaria.
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Castagnoli KP, Shinohara Y, Furuta T, Nguyen TL, Gruenke LD, Miller RD, Castagnoli N. Quantitative estimation of quaternary ammonium neuromuscular blocking agents in serum by direct insertion probe chemical ionization mass spectrometry. Biomed Environ Mass Spectrom 1986; 13:327-32. [PMID: 2874852 DOI: 10.1002/bms.1200130703] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
A new method based on selected ion monitoring chemical ionization mass spectrometry was developed to measure the quaternary ammonium neuromuscular blocking agents, pancuronium and vecuronium, in serum. An ion-pair extraction procedure is utilized to separate the compounds of interest from biological fluids. The intensities of the ion currents produced by the bisamines formed from the drugs and the corresponding deuterated internal standards through thermolytic dequaternization are monitored. The assay shows good linearity over the range of 1-500 ng/ml. This assay has been utilized in a variety of clinical pharmacokinetic studies involving surgical pediatric, geriatric and obstetric patients requiring anesthesia.
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Gruenke LD, Craig JC, Klein FD, Nguyen TL, Hitzemann BA, Holaday JW, Loh HH, Braff L, Fischer A, Glick ID. Determination of chlorpromazine and its major metabolites by gas chromatography/mass spectrometry: application to biological fluids. Biomed Mass Spectrom 1985; 12:707-13. [PMID: 2936401 DOI: 10.1002/bms.1200121207] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
A method for the quantitative determination of chlorpromazine and five of its major metabolites in a single sample of biological fluid in the ng/ml range has been developed utilizing gas chromatography/mass spectrometry with selected ion recording. The assay is highly specific and quantification is accomplished by an inverse stable isotope dilution technique, using deuterium-labeled variants of the compounds as internal standards. In this way the concentrations of chlorpromazine and five of its major metabolites (the sulfoxide, the N-oxide, the monodemethylated, the didemethylated, and the 7-hydroxylated compounds) can be determined in biological fluids. Levels in humans have been measured both in plasma and in red blood cells and are compared to those found in related in vitro studies.
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Nguyen H, Leroy JP, Vallée B, Person H, Nguyen TL, Nguyen HV. [A little known segment of the cardiac wall: the muscular atrioventricular septum]. Ann Chir 1983; 37:558-61. [PMID: 6680826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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