Phương Uyên Nguyễn - Academia.edu (original) (raw)
Papers by Phương Uyên Nguyễn
The Journal of Immunology, 2000
Kaposi’s sarcoma-associated herpes virus (KSHV) is a recently identified human γ2-herpesvirus ass... more Kaposi’s sarcoma-associated herpes virus (KSHV) is a recently identified human γ2-herpesvirus associated with Kaposi’s sarcoma, primary effusion lymphoma, and Castleman’s disease. We reasoned that CTL responses may provide host defense against this virus, and consequently, KSHV may have evolved strategies to evade the CTL-mediated immune surveillance. In this study six B cell lines latently infected with KSHV were found to express reduced levels of HLA class I surface molecules compared with B cell lines transformed by the related γ-herpesvirus EBV. KSHV-infected cells also required higher concentrations of soluble peptides to induce efficient CTL-mediated lysis than control cell lines and were unable to process and/or present intracellularly expressed Ag. Incubation of the KSHV-infected cell lines with high concentrations of soluble HLA class I binding peptides did not restore the deficient HLA class I surface expression. To assess the underlying mechanisms of these phenomena, TAP-...
Can Tho University Journal of Science
Vibrio spp. là nguyên nhân gây ra các bệnh vi khuẩn trên thủy sản nói chung và tôm nói riêng. Phư... more Vibrio spp. là nguyên nhân gây ra các bệnh vi khuẩn trên thủy sản nói chung và tôm nói riêng. Phương pháp điều trị bằng kháng sinh đã tạo ra các chủng vi sinh vật đa kháng thuốc. Mục đích của nghiên cứu này là đánh giá ảnh hưởng của cao chiết và cao chiết kết hợp thực khuẩn thể đối với các dòng Vibrio spp. Nghiên cứu được thực hiện theo hai phương pháp là khuếch tán qua đĩa thạch và trải đếm so sánh mật số vi khuẩn. Kết quả cho thấy, ở thí nghiệm khuếch tán qua đĩa thạch, hầu hết cao chiết và cao chiết kết hợp thực khuẩn thể đều tạo vòng ức chế, khác biệt có ý nghĩa thống kê so với đối chứng tetracycline 5 mg/mL. Kết quả trải đếm cho thấy hầu hết các loại thực khuẩn thể và cao chiết đều làm giảm mật số vi khuẩn. Tuy nhiên, cao chiết lựu, cao chiết đầu lân và ɸTT1H, ɸTT2H làm thay đổi mật số không có ý nghĩa thống kê (p<0,05).
Vietnamese Journal of Radiology and Nuclear Medicine
Mục tiêu: Khảo sát đặc điểm siêu âm đường thông động mạch quay - tĩnh mạch đầu sau mổ 2 tuần và 3... more Mục tiêu: Khảo sát đặc điểm siêu âm đường thông động mạch quay - tĩnh mạch đầu sau mổ 2 tuần và 3 tuần trên bệnh nhân suy thận mạn có chỉ định lọc máu chu kỳ.Đối tượng và phương pháp nghiên cứu: Nghiên cứu trên 34 bệnh nhân suy thận mạn có chỉ định lọc máu chu kỳ, được mổ tạo thông nối động mạch quay - tĩnh mạch đầu bên tận ở cẳng tay, được siêu âm sau mổ 2 tuần và 3 tuần từ tháng 4/2016 đến tháng 7/2017, tại khoa Thận nhân tạo bệnh viện Trung Ương Huế.Kết quả: Độ tuổi trung bình của bệnh nhân 45,79 ± 14,59 tuổi; nam chiếm 47,10%, nữ chiếm 52,90%. Tỷ lệ bệnh nhân đái tháo đường là 5,88%. Đường kính tĩnh mạch dẫn lưu sau mổ 2 tuần là 4,96 ± 0,88 mm và sau 3 tuần là 5,40 ± 0,99 mm (p < 0,05); lưu lượng tĩnh mạch dẫn lưu sau mổ 2 tuần và 3 tuần là 531,33 ± 162,40 ml/p và 666,56 ± 260 ml/p (p < 0,05). Tỷ lệ đường thông động tĩnh mạch trưởng thành sau mổ 3 tuần là 82,35%. Bất thường đường thông động tĩnh mạch (Đ-TM) gặp nhiều nhất là hẹp ở tĩnh mạch dẫn lưu và miệng nối.Kết luận: S...
Current opinion in immunology, Jan 26, 2018
The emergence of avian influenza viruses stimulated pandemic concerns and efforts to develop prot... more The emergence of avian influenza viruses stimulated pandemic concerns and efforts to develop protective vaccines. Studies of the immune responses to experimental vaccines for pandemic influenza have taught us lessons about human immunity to influenza in general that can be applied to seasonal, pandemic, and even universal vaccine responses. For example, the concepts of targeting the hemagglutinin stalk and elicitation of stalk reactive antibodies grew out of studies of the 2009 pandemic H1N1 vaccines. More recently, the phenomenon of imprinting, the influence of early life exposure to influenza modifying responses to the viruses or vaccines later in life, has been reinforced through the study of potential pandemic influenza virus vaccines such as H7N9. These studies have also revealed potential strategies to improve responses to novel influenza strains and produce more broadly cross-reactive B cell and antibody responses. These concepts are discussed in detail in this review.
Aquaculture Research, 2014
Lipopolysaccharide (LPS), a component of Gram negative bacteria, was reported as important immuno... more Lipopolysaccharide (LPS), a component of Gram negative bacteria, was reported as important immunostimulant for fish. In this study, striped catfish were fed diets containing different Escherichia coli LPS concentrations (0%, 0.01% and 0.05%) for 2 weeks and then fed control feed (0% LPS) for 4 weeks. Plasma cortisol and glucose were rather low and did not differ significantly among treatments (P > 0.05). The respiratory burst activity, lysozyme, complement, total of antibody as well as mortality in fish challenged with Edwardsiella ictaluri were recorded every 2 weeks (W2, W4 and W6). The lysozyme activity significantly increased in fish treated with LPS (P < 0.05) in W2, W4 and W6. The highest values of respiratory burst activity were observed at week 4 in fish fed 0.01% LPS. There were significant differences in total of antibody between fish fed LPS (0.01%) and control in W2, W4. The challenge test with Edwardsiella ictaluri showed that fish fed 0.01% LPS had lower cumulative mortality (40%, 33% and 42%) compared with the fish fed 0.05% LPS (50%, 40% and 47%) and control fish (40%, 57% and 53%) in the three difference sampling times respectively. These results suggest that feed supplemented with 0.01% LPS could enhance immunity of striped catfish after 2 weeks of oral administration and fish could be protected against bacterial infection during the following 4 weeks.
Microbial Cell Factories, 2014
Background: The development of chemical refolding of transforming growth factor-beta (TGF-β) supe... more Background: The development of chemical refolding of transforming growth factor-beta (TGF-β) superfamily ligands has been instrumental to produce the recombinant proteins for biochemical studies and exploring the potential of protein therapeutics. The osteogenic human bone morphogenetic protein-2 (hBMP-2) and its Drosophila DPP homolog were the early successful cases of refolding into functional form. Despite the similarity in their three dimensional structure and amino acid sequences, several other TGF-β superfamily ligands could not be refolded readily by the same methods. Results: Here, we report a comprehensive study on the variables of a rapid-dilution refolding method, including the concentrations of protein, salt, detergent and redox agents, pH, refolding duration and the presence of aggregation suppressors and host-cell contaminants, in order to identify the optimal condition to refold human BMP-9 (hBMP-9). To produce a recombinant form of hBMP-9 in E. coli cells, a synthetic codon-optimized gene was designed to encode the mature domain of hBMP-9 (Ser320-Arg429) directly behind the first methionine, which we herein referred to as MB109. An effective purification scheme was also developed to purify the refolded MB109 to homogeneity with a final yield of 7.8 mg from 100 mg of chromatography-purified inclusion bodies as a starting material. The chemically refolded MB109 binds to ALK1, ActRIIb and BMPRII receptors with relatively high affinity as compared to other Type I and Type II receptors based on surface plasmon resonance analysis. Smad1-dependent luciferase assay in C2C12 cells shows that the MB109 has an EC 50 of 0.61 ng/mL (25 pM), which is nearly the same as hBMP-9. Conclusion: MB109 is prone to be refolded as non-functional dimer and higher order multimers in most of the conditions tested, but bioactive MB109 dimer can be refolded with high efficiency in a narrow window, which is strongly dependent on the pH, refolding duration, the presence of aggregation suppressors and the concentrations of protein, salt and detegent. These results add to the current understanding of producing recombinant TGF-β superfamily ligands in the microbial E. coli system. An application of the technique to produce a large number of synthetic TGF-β chimeras for activity screen is also discussed.
Journal of Periodontology, 2011
Background: Periodontitis is a local inflammatory disease that also has some systemic effects. We... more Background: Periodontitis is a local inflammatory disease that also has some systemic effects. We investigated the levels of interferon (IFN)-g, tumor necrosis factor (TNF)-a, and interleukin (IL)-2,-4,-5, and-10 in the serum of patients with periodontitis in relation to the bacterial load in the dental plaques. Methods: Serum cytokine levels in patients with generalized periodontitis and healthy control groups were determined using the cytometric bead array kit. Bacterial load in the dental plaque was determined semiquantitatively by real-time polymerase chain reaction. The proportions of different lymphocyte subsets were determined in the peripheral blood of patients with periodontitis by flow cytometry. Finally, relationships between the bacterial load in the subgingival plaques of patients with periodontitis and levels of cytokines and counts of lymphocyte subsets were established. Results: Serum levels of IFN-g, TNF-a, and IL-10 were significantly increased, whereas those of IL-2 were significantly decreased in patients with periodontitis compared to healthy controls. Increased serum levels of IFN-g and TNF-a in patients with periodontitis were associated with the enhanced dental plaque load with Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans) and Porphyromonas gingivalis, respectively. Finally, as revealed by analysis of lymphocyte populations, the presence of A. actinomycetemcomitans and Trepomena denticola was associated with an increased population of CD3-/CD16 + and CD3 + /CD8 + cells, respectively. Conclusion: Certain periodontal pathogens could be associated with an increased level of proinflammatory cytokines in the peripheral blood and thus increased risk of systemic diseases.
The Journal of Immunology, 2000
The precise immunologic functions of CD1d-restricted, CD161+ AV24AJ18 (Vα24JαQ) T cells are not w... more The precise immunologic functions of CD1d-restricted, CD161+ AV24AJ18 (Vα24JαQ) T cells are not well defined, although production of IL-4 has been suggested as important for priming Th2 responses. However, activation of human Vα24JαQ T cell clones by anti-CD3 resulted in the secretion of multiple cytokines notably important for the recruitment and differentiation of myeloid dendritic cells. Specific activation of Vα24JαQ T cells was CD1d restricted. Expression of CD1d was found on monocyte-derived dendritic cells in vitro, and immunohistochemical staining directly revealed CD1d preferentially expressed on dendritic cells in the paracortical T cell zones of lymph nodes. Moreover, myeloid dendritic cells both activated Vα24JαQ T cells and were susceptible to lysis by these same regulatory T cells. Because myeloid dendritic cells are a major source of IL-12 and control Th1 cell differentiation, their elimination by lysis is a mechanism for limiting the generation of Th1 cells and thus ...
The Journal of Immunology, 2000
The precise immunologic functions of CD1d-restricted, CD161+ AV24AJ18 (Vα24JαQ) T cells are not w... more The precise immunologic functions of CD1d-restricted, CD161+ AV24AJ18 (Vα24JαQ) T cells are not well defined, although production of IL-4 has been suggested as important for priming Th2 responses. However, activation of human Vα24JαQ T cell clones by anti-CD3 resulted in the secretion of multiple cytokines notably important for the recruitment and differentiation of myeloid dendritic cells. Specific activation of Vα24JαQ T cells was CD1d restricted. Expression of CD1d was found on monocyte-derived dendritic cells in vitro, and immunohistochemical staining directly revealed CD1d preferentially expressed on dendritic cells in the paracortical T cell zones of lymph nodes. Moreover, myeloid dendritic cells both activated Vα24JαQ T cells and were susceptible to lysis by these same regulatory T cells. Because myeloid dendritic cells are a major source of IL-12 and control Th1 cell differentiation, their elimination by lysis is a mechanism for limiting the generation of Th1 cells and thus ...
Accounts of Chemical Research, 2014
E volution has fine-tuned proteins to accomplish a variety of tasks. Yet, with aging, some protei... more E volution has fine-tuned proteins to accomplish a variety of tasks. Yet, with aging, some proteins assemble into harmful amyloid aggregates associated with neurodegenerative diseases, such as Alzheimer's disease (AD), which presents a complex and costly challenge to our society. Thus, far, drug after drug has failed to slow the progression of AD, characterized by the self-assembly of the 39À43 amino acid β-amyloid (Aβ) protein into extracellular senile plaques that form a cross-β structure. While there is experimental evidence that the Aβ small oligomers are the primary toxic species, standard tools of biology have failed to provide structures of these transient, inhomogeneous assemblies. Despite extensive experimental studies, researchers have not successfully characterized the nucleus ensemble, the starting point for rapid fibril formation. Similarly scientists do not have atomic data to show how the compounds that reduce both fibril formation and toxicity in cells bind to Aβ42 oligomers. In this context, computer simulations are important tools for gaining insights into the self-assembly of amyloid peptides and the molecular mechanism of inhibitors. This Account reviews what analytical models and simulations at different time and length scales tell us about the dynamics, kinetics, and thermodynamics of amyloid fibril formation and, notably, the nucleation process. Though coarse-grained and mesoscopic protein models approximate atomistic details by averaging out unimportant degrees of freedom, they provide generic features of amyloid formation and insights into mechanistic details of the self-assembly process. The thermodynamics and kinetics vary from linear peptides adopting straight β-strands in fibrils to longer peptides adopting in parallel U shaped conformations in fibrils. In addition, these properties change with the balance between electrostatic and hydrophobic interactions and the intrinsic disorder of the system. However, simulations suggest that the critical nucleus size might be on the order of 20 chains under physiological conditions. The transition state might be characterized by a simultaneous change from mixed antiparallel/parallel β-strands with random side-chain packing to the final antiparallel or parallel states with the steric zipper packing of the side chains. Second, we review our current computer-based knowledge of the 3D structures of inhibitors with Aβ42 monomer and oligomers, a prerequisite for developing new drugs against AD. Recent extensive all-atom simulations of Aβ42 dimers with known inhibitors such as the green tea compound epigallocatechin-3-gallate and 1,4-naphthoquinon-2-yl-L-tryptophan provide a spectrum of initial Aβ42/inhibitor structures useful for screening and drug design. We conclude by discussing future directions that may offer opportunities to fully understand nucleation and further AD drug development.
Tạp chí Y Dược học Cần Thơ
Đặt vấn đề: Ung thư đại trực tràng là ung thư phổ biến và tử vong cao. Nội soi đại trực tràng phá... more Đặt vấn đề: Ung thư đại trực tràng là ung thư phổ biến và tử vong cao. Nội soi đại trực tràng phát hiện và cắt bỏ polyp là biện pháp phòng ngừa quan trọng nhất, làm giảm 76 – 90% số ca ung thư đại trực tràng mới. Mục tiêu nghiên cứu: Đánh giá tỉ lệ phát hiện polyp và các yếu tố liên quan qua nội soi đại trực tràng có NBI, mức độ tương hợp giữa bảng phân loại NICE và kết quả giải phẫu bệnh. Đối tượng và phương pháp nghiên cứu: Nghiên cứu tiến cứu các bệnh nhân được nội soi đại trực tràng có dải tần hẹp (NBI - Narrow - band imaging) về các yếu tố: Tỉ lệ phát hiện polyp, tuổi, giới tính, BMI, thói quen sinh hoạt, bệnh lý mãn tính, yếu tố gia đình, đặc điểm polyp, giải phẫu bệnh. Kết quả: 305 trường hợp nội soi đại tràng đủ tiêu chuẩn lấy mẫu. Tuổi trung bình là 50,07 (nhỏ nhất 16 tuổi – lớn nhất 84 tuổi), tỉ lệ nam nữ là 45,6/54,4. Tỉ lệ phát hiện polyp (PDR - polyp detection rate) là 38,4%, tỉ lệ phát hiện polyp tuyến (ADR - adenoma detection rate) là 18,7% tổng dân số lấy mẫu. Tuổi l...
The Journal of Immunology, 2000
Kaposi’s sarcoma-associated herpes virus (KSHV) is a recently identified human γ2-herpesvirus ass... more Kaposi’s sarcoma-associated herpes virus (KSHV) is a recently identified human γ2-herpesvirus associated with Kaposi’s sarcoma, primary effusion lymphoma, and Castleman’s disease. We reasoned that CTL responses may provide host defense against this virus, and consequently, KSHV may have evolved strategies to evade the CTL-mediated immune surveillance. In this study six B cell lines latently infected with KSHV were found to express reduced levels of HLA class I surface molecules compared with B cell lines transformed by the related γ-herpesvirus EBV. KSHV-infected cells also required higher concentrations of soluble peptides to induce efficient CTL-mediated lysis than control cell lines and were unable to process and/or present intracellularly expressed Ag. Incubation of the KSHV-infected cell lines with high concentrations of soluble HLA class I binding peptides did not restore the deficient HLA class I surface expression. To assess the underlying mechanisms of these phenomena, TAP-...
Can Tho University Journal of Science
Vibrio spp. là nguyên nhân gây ra các bệnh vi khuẩn trên thủy sản nói chung và tôm nói riêng. Phư... more Vibrio spp. là nguyên nhân gây ra các bệnh vi khuẩn trên thủy sản nói chung và tôm nói riêng. Phương pháp điều trị bằng kháng sinh đã tạo ra các chủng vi sinh vật đa kháng thuốc. Mục đích của nghiên cứu này là đánh giá ảnh hưởng của cao chiết và cao chiết kết hợp thực khuẩn thể đối với các dòng Vibrio spp. Nghiên cứu được thực hiện theo hai phương pháp là khuếch tán qua đĩa thạch và trải đếm so sánh mật số vi khuẩn. Kết quả cho thấy, ở thí nghiệm khuếch tán qua đĩa thạch, hầu hết cao chiết và cao chiết kết hợp thực khuẩn thể đều tạo vòng ức chế, khác biệt có ý nghĩa thống kê so với đối chứng tetracycline 5 mg/mL. Kết quả trải đếm cho thấy hầu hết các loại thực khuẩn thể và cao chiết đều làm giảm mật số vi khuẩn. Tuy nhiên, cao chiết lựu, cao chiết đầu lân và ɸTT1H, ɸTT2H làm thay đổi mật số không có ý nghĩa thống kê (p<0,05).
Vietnamese Journal of Radiology and Nuclear Medicine
Mục tiêu: Khảo sát đặc điểm siêu âm đường thông động mạch quay - tĩnh mạch đầu sau mổ 2 tuần và 3... more Mục tiêu: Khảo sát đặc điểm siêu âm đường thông động mạch quay - tĩnh mạch đầu sau mổ 2 tuần và 3 tuần trên bệnh nhân suy thận mạn có chỉ định lọc máu chu kỳ.Đối tượng và phương pháp nghiên cứu: Nghiên cứu trên 34 bệnh nhân suy thận mạn có chỉ định lọc máu chu kỳ, được mổ tạo thông nối động mạch quay - tĩnh mạch đầu bên tận ở cẳng tay, được siêu âm sau mổ 2 tuần và 3 tuần từ tháng 4/2016 đến tháng 7/2017, tại khoa Thận nhân tạo bệnh viện Trung Ương Huế.Kết quả: Độ tuổi trung bình của bệnh nhân 45,79 ± 14,59 tuổi; nam chiếm 47,10%, nữ chiếm 52,90%. Tỷ lệ bệnh nhân đái tháo đường là 5,88%. Đường kính tĩnh mạch dẫn lưu sau mổ 2 tuần là 4,96 ± 0,88 mm và sau 3 tuần là 5,40 ± 0,99 mm (p < 0,05); lưu lượng tĩnh mạch dẫn lưu sau mổ 2 tuần và 3 tuần là 531,33 ± 162,40 ml/p và 666,56 ± 260 ml/p (p < 0,05). Tỷ lệ đường thông động tĩnh mạch trưởng thành sau mổ 3 tuần là 82,35%. Bất thường đường thông động tĩnh mạch (Đ-TM) gặp nhiều nhất là hẹp ở tĩnh mạch dẫn lưu và miệng nối.Kết luận: S...
Current opinion in immunology, Jan 26, 2018
The emergence of avian influenza viruses stimulated pandemic concerns and efforts to develop prot... more The emergence of avian influenza viruses stimulated pandemic concerns and efforts to develop protective vaccines. Studies of the immune responses to experimental vaccines for pandemic influenza have taught us lessons about human immunity to influenza in general that can be applied to seasonal, pandemic, and even universal vaccine responses. For example, the concepts of targeting the hemagglutinin stalk and elicitation of stalk reactive antibodies grew out of studies of the 2009 pandemic H1N1 vaccines. More recently, the phenomenon of imprinting, the influence of early life exposure to influenza modifying responses to the viruses or vaccines later in life, has been reinforced through the study of potential pandemic influenza virus vaccines such as H7N9. These studies have also revealed potential strategies to improve responses to novel influenza strains and produce more broadly cross-reactive B cell and antibody responses. These concepts are discussed in detail in this review.
Aquaculture Research, 2014
Lipopolysaccharide (LPS), a component of Gram negative bacteria, was reported as important immuno... more Lipopolysaccharide (LPS), a component of Gram negative bacteria, was reported as important immunostimulant for fish. In this study, striped catfish were fed diets containing different Escherichia coli LPS concentrations (0%, 0.01% and 0.05%) for 2 weeks and then fed control feed (0% LPS) for 4 weeks. Plasma cortisol and glucose were rather low and did not differ significantly among treatments (P > 0.05). The respiratory burst activity, lysozyme, complement, total of antibody as well as mortality in fish challenged with Edwardsiella ictaluri were recorded every 2 weeks (W2, W4 and W6). The lysozyme activity significantly increased in fish treated with LPS (P < 0.05) in W2, W4 and W6. The highest values of respiratory burst activity were observed at week 4 in fish fed 0.01% LPS. There were significant differences in total of antibody between fish fed LPS (0.01%) and control in W2, W4. The challenge test with Edwardsiella ictaluri showed that fish fed 0.01% LPS had lower cumulative mortality (40%, 33% and 42%) compared with the fish fed 0.05% LPS (50%, 40% and 47%) and control fish (40%, 57% and 53%) in the three difference sampling times respectively. These results suggest that feed supplemented with 0.01% LPS could enhance immunity of striped catfish after 2 weeks of oral administration and fish could be protected against bacterial infection during the following 4 weeks.
Microbial Cell Factories, 2014
Background: The development of chemical refolding of transforming growth factor-beta (TGF-β) supe... more Background: The development of chemical refolding of transforming growth factor-beta (TGF-β) superfamily ligands has been instrumental to produce the recombinant proteins for biochemical studies and exploring the potential of protein therapeutics. The osteogenic human bone morphogenetic protein-2 (hBMP-2) and its Drosophila DPP homolog were the early successful cases of refolding into functional form. Despite the similarity in their three dimensional structure and amino acid sequences, several other TGF-β superfamily ligands could not be refolded readily by the same methods. Results: Here, we report a comprehensive study on the variables of a rapid-dilution refolding method, including the concentrations of protein, salt, detergent and redox agents, pH, refolding duration and the presence of aggregation suppressors and host-cell contaminants, in order to identify the optimal condition to refold human BMP-9 (hBMP-9). To produce a recombinant form of hBMP-9 in E. coli cells, a synthetic codon-optimized gene was designed to encode the mature domain of hBMP-9 (Ser320-Arg429) directly behind the first methionine, which we herein referred to as MB109. An effective purification scheme was also developed to purify the refolded MB109 to homogeneity with a final yield of 7.8 mg from 100 mg of chromatography-purified inclusion bodies as a starting material. The chemically refolded MB109 binds to ALK1, ActRIIb and BMPRII receptors with relatively high affinity as compared to other Type I and Type II receptors based on surface plasmon resonance analysis. Smad1-dependent luciferase assay in C2C12 cells shows that the MB109 has an EC 50 of 0.61 ng/mL (25 pM), which is nearly the same as hBMP-9. Conclusion: MB109 is prone to be refolded as non-functional dimer and higher order multimers in most of the conditions tested, but bioactive MB109 dimer can be refolded with high efficiency in a narrow window, which is strongly dependent on the pH, refolding duration, the presence of aggregation suppressors and the concentrations of protein, salt and detegent. These results add to the current understanding of producing recombinant TGF-β superfamily ligands in the microbial E. coli system. An application of the technique to produce a large number of synthetic TGF-β chimeras for activity screen is also discussed.
Journal of Periodontology, 2011
Background: Periodontitis is a local inflammatory disease that also has some systemic effects. We... more Background: Periodontitis is a local inflammatory disease that also has some systemic effects. We investigated the levels of interferon (IFN)-g, tumor necrosis factor (TNF)-a, and interleukin (IL)-2,-4,-5, and-10 in the serum of patients with periodontitis in relation to the bacterial load in the dental plaques. Methods: Serum cytokine levels in patients with generalized periodontitis and healthy control groups were determined using the cytometric bead array kit. Bacterial load in the dental plaque was determined semiquantitatively by real-time polymerase chain reaction. The proportions of different lymphocyte subsets were determined in the peripheral blood of patients with periodontitis by flow cytometry. Finally, relationships between the bacterial load in the subgingival plaques of patients with periodontitis and levels of cytokines and counts of lymphocyte subsets were established. Results: Serum levels of IFN-g, TNF-a, and IL-10 were significantly increased, whereas those of IL-2 were significantly decreased in patients with periodontitis compared to healthy controls. Increased serum levels of IFN-g and TNF-a in patients with periodontitis were associated with the enhanced dental plaque load with Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans) and Porphyromonas gingivalis, respectively. Finally, as revealed by analysis of lymphocyte populations, the presence of A. actinomycetemcomitans and Trepomena denticola was associated with an increased population of CD3-/CD16 + and CD3 + /CD8 + cells, respectively. Conclusion: Certain periodontal pathogens could be associated with an increased level of proinflammatory cytokines in the peripheral blood and thus increased risk of systemic diseases.
The Journal of Immunology, 2000
The precise immunologic functions of CD1d-restricted, CD161+ AV24AJ18 (Vα24JαQ) T cells are not w... more The precise immunologic functions of CD1d-restricted, CD161+ AV24AJ18 (Vα24JαQ) T cells are not well defined, although production of IL-4 has been suggested as important for priming Th2 responses. However, activation of human Vα24JαQ T cell clones by anti-CD3 resulted in the secretion of multiple cytokines notably important for the recruitment and differentiation of myeloid dendritic cells. Specific activation of Vα24JαQ T cells was CD1d restricted. Expression of CD1d was found on monocyte-derived dendritic cells in vitro, and immunohistochemical staining directly revealed CD1d preferentially expressed on dendritic cells in the paracortical T cell zones of lymph nodes. Moreover, myeloid dendritic cells both activated Vα24JαQ T cells and were susceptible to lysis by these same regulatory T cells. Because myeloid dendritic cells are a major source of IL-12 and control Th1 cell differentiation, their elimination by lysis is a mechanism for limiting the generation of Th1 cells and thus ...
The Journal of Immunology, 2000
The precise immunologic functions of CD1d-restricted, CD161+ AV24AJ18 (Vα24JαQ) T cells are not w... more The precise immunologic functions of CD1d-restricted, CD161+ AV24AJ18 (Vα24JαQ) T cells are not well defined, although production of IL-4 has been suggested as important for priming Th2 responses. However, activation of human Vα24JαQ T cell clones by anti-CD3 resulted in the secretion of multiple cytokines notably important for the recruitment and differentiation of myeloid dendritic cells. Specific activation of Vα24JαQ T cells was CD1d restricted. Expression of CD1d was found on monocyte-derived dendritic cells in vitro, and immunohistochemical staining directly revealed CD1d preferentially expressed on dendritic cells in the paracortical T cell zones of lymph nodes. Moreover, myeloid dendritic cells both activated Vα24JαQ T cells and were susceptible to lysis by these same regulatory T cells. Because myeloid dendritic cells are a major source of IL-12 and control Th1 cell differentiation, their elimination by lysis is a mechanism for limiting the generation of Th1 cells and thus ...
Accounts of Chemical Research, 2014
E volution has fine-tuned proteins to accomplish a variety of tasks. Yet, with aging, some protei... more E volution has fine-tuned proteins to accomplish a variety of tasks. Yet, with aging, some proteins assemble into harmful amyloid aggregates associated with neurodegenerative diseases, such as Alzheimer's disease (AD), which presents a complex and costly challenge to our society. Thus, far, drug after drug has failed to slow the progression of AD, characterized by the self-assembly of the 39À43 amino acid β-amyloid (Aβ) protein into extracellular senile plaques that form a cross-β structure. While there is experimental evidence that the Aβ small oligomers are the primary toxic species, standard tools of biology have failed to provide structures of these transient, inhomogeneous assemblies. Despite extensive experimental studies, researchers have not successfully characterized the nucleus ensemble, the starting point for rapid fibril formation. Similarly scientists do not have atomic data to show how the compounds that reduce both fibril formation and toxicity in cells bind to Aβ42 oligomers. In this context, computer simulations are important tools for gaining insights into the self-assembly of amyloid peptides and the molecular mechanism of inhibitors. This Account reviews what analytical models and simulations at different time and length scales tell us about the dynamics, kinetics, and thermodynamics of amyloid fibril formation and, notably, the nucleation process. Though coarse-grained and mesoscopic protein models approximate atomistic details by averaging out unimportant degrees of freedom, they provide generic features of amyloid formation and insights into mechanistic details of the self-assembly process. The thermodynamics and kinetics vary from linear peptides adopting straight β-strands in fibrils to longer peptides adopting in parallel U shaped conformations in fibrils. In addition, these properties change with the balance between electrostatic and hydrophobic interactions and the intrinsic disorder of the system. However, simulations suggest that the critical nucleus size might be on the order of 20 chains under physiological conditions. The transition state might be characterized by a simultaneous change from mixed antiparallel/parallel β-strands with random side-chain packing to the final antiparallel or parallel states with the steric zipper packing of the side chains. Second, we review our current computer-based knowledge of the 3D structures of inhibitors with Aβ42 monomer and oligomers, a prerequisite for developing new drugs against AD. Recent extensive all-atom simulations of Aβ42 dimers with known inhibitors such as the green tea compound epigallocatechin-3-gallate and 1,4-naphthoquinon-2-yl-L-tryptophan provide a spectrum of initial Aβ42/inhibitor structures useful for screening and drug design. We conclude by discussing future directions that may offer opportunities to fully understand nucleation and further AD drug development.
Tạp chí Y Dược học Cần Thơ
Đặt vấn đề: Ung thư đại trực tràng là ung thư phổ biến và tử vong cao. Nội soi đại trực tràng phá... more Đặt vấn đề: Ung thư đại trực tràng là ung thư phổ biến và tử vong cao. Nội soi đại trực tràng phát hiện và cắt bỏ polyp là biện pháp phòng ngừa quan trọng nhất, làm giảm 76 – 90% số ca ung thư đại trực tràng mới. Mục tiêu nghiên cứu: Đánh giá tỉ lệ phát hiện polyp và các yếu tố liên quan qua nội soi đại trực tràng có NBI, mức độ tương hợp giữa bảng phân loại NICE và kết quả giải phẫu bệnh. Đối tượng và phương pháp nghiên cứu: Nghiên cứu tiến cứu các bệnh nhân được nội soi đại trực tràng có dải tần hẹp (NBI - Narrow - band imaging) về các yếu tố: Tỉ lệ phát hiện polyp, tuổi, giới tính, BMI, thói quen sinh hoạt, bệnh lý mãn tính, yếu tố gia đình, đặc điểm polyp, giải phẫu bệnh. Kết quả: 305 trường hợp nội soi đại tràng đủ tiêu chuẩn lấy mẫu. Tuổi trung bình là 50,07 (nhỏ nhất 16 tuổi – lớn nhất 84 tuổi), tỉ lệ nam nữ là 45,6/54,4. Tỉ lệ phát hiện polyp (PDR - polyp detection rate) là 38,4%, tỉ lệ phát hiện polyp tuyến (ADR - adenoma detection rate) là 18,7% tổng dân số lấy mẫu. Tuổi l...