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MacKerell AD, Bashford D, Bellott M, Dunbrack RL, Evanseck JD, Field MJ, Fischer S, Gao J, Guo H, Ha S, Joseph-McCarthy D, Kuchnir L, Kuczera K, Lau FT, Mattos C, Michnick S, Ngo T, Nguyen DT, Prodhom B, Reiher WE, Roux B, Schlenkrich M, Smith JC, Stote R, Straub J, Watanabe M, Wiórkiewicz-Kuczera J, Yin D, Karplus M. All-atom empirical potential for molecular modeling and dynamics studies of proteins. J Phys Chem B 2014; 102:3586-616. [PMID: 24889800 DOI: 10.1021/jp973084f] [Citation(s) in RCA: 11152] [Impact Index Per Article: 1013.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
New protein parameters are reported for the all-atom empirical energy function in the CHARMM program. The parameter evaluation was based on a self-consistent approach designed to achieve a balance between the internal (bonding) and interaction (nonbonding) terms of the force field and among the solvent-solvent, solvent-solute, and solute-solute interactions. Optimization of the internal parameters used experimental gas-phase geometries, vibrational spectra, and torsional energy surfaces supplemented with ab initio results. The peptide backbone bonding parameters were optimized with respect to data for N-methylacetamide and the alanine dipeptide. The interaction parameters, particularly the atomic charges, were determined by fitting ab initio interaction energies and geometries of complexes between water and model compounds that represented the backbone and the various side chains. In addition, dipole moments, experimental heats and free energies of vaporization, solvation and sublimation, molecular volumes, and crystal pressures and structures were used in the optimization. The resulting protein parameters were tested by applying them to noncyclic tripeptide crystals, cyclic peptide crystals, and the proteins crambin, bovine pancreatic trypsin inhibitor, and carbonmonoxy myoglobin in vacuo and in crystals. A detailed analysis of the relationship between the alanine dipeptide potential energy surface and calculated protein φ, χ angles was made and used in optimizing the peptide group torsional parameters. The results demonstrate that use of ab initio structural and energetic data by themselves are not sufficient to obtain an adequate backbone representation for peptides and proteins in solution and in crystals. Extensive comparisons between molecular dynamics simulations and experimental data for polypeptides and proteins were performed for both structural and dynamic properties. Energy minimization and dynamics simulations for crystals demonstrate that the latter are needed to obtain meaningful comparisons with experimental crystal structures. The presented parameters, in combination with the previously published CHARMM all-atom parameters for nucleic acids and lipids, provide a consistent set for condensed-phase simulations of a wide variety of molecules of biological interest.
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Miyazaki H, Oh-ishi S, Ookawara T, Kizaki T, Toshinai K, Ha S, Haga S, Ji LL, Ohno H. Strenuous endurance training in humans reduces oxidative stress following exhausting exercise. Eur J Appl Physiol 2001; 84:1-6. [PMID: 11394236 DOI: 10.1007/s004210000342] [Citation(s) in RCA: 233] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The aim of this study was to evaluate whether high-intensity endurance training would alleviate exercise-induced oxidative stress. Nine untrained male subjects (aged 19-21 years) participated in a 12-week training programme, and performed an acute period of exhausting exercise on a cycle ergometer before and after training. The training programme consisted of running at 80% maximal exercise heart rate for 60 min.day-1, 5 days.week-1 for 12 weeks. Blood samples were collected at rest and immediately after exhausting exercise for measurements of indices of oxidative stress, and antioxidant enzyme activities [superoxide dismutase (SOD), glutathione peroxidase (GPX), and catalase (CAT)] in the erythrocytes. Maximal oxygen uptake (VO2max) increased significantly (P < 0.001) after training, indicating an improvement in aerobic capacity. A period of exhausting exercise caused an increase (P < 0.01) in the ability to produce neutrophil superoxide anion (O2.-) both before and after endurance training, but the magnitude of the increase was smaller after training (P < 0.05). There was a significant increase in lipid peroxidation in the erythrocyte membrane, but not in oxidative protein, after exhausting exercise, however training attenuated this effect. At rest, SOD and GPX activities were increased after training. However, there was no evidence that exhausting exercise enhanced the levels of any antioxidant enzyme activity. The CAT activity was unchanged either by training or by exhausting exercise. These results indicate that high-intensity endurance training can elevate antioxidant enzyme activities in erythrocytes, and decrease neutrophil O2.- production in response to exhausting exercise. Furthermore, this up-regulation in antioxidant defences was accompanied by a reduction in exercise-induced lipid peroxidation in erythrocyte membrane.
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Ha S, Walker D, Shi Y, Walker S. The 1.9 A crystal structure of Escherichia coli MurG, a membrane-associated glycosyltransferase involved in peptidoglycan biosynthesis. Protein Sci 2000; 9:1045-52. [PMID: 10892798 PMCID: PMC2144650 DOI: 10.1110/ps.9.6.1045] [Citation(s) in RCA: 184] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The 1.9 A X-ray structure of a membrane-associated glycosyltransferase involved in peptidoglycan biosynthesis is reported. This enzyme, MurG, contains two alpha/beta open sheet domains separated by a deep cleft. Structural analysis suggests that the C-terminal domain contains the UDP-GlcNAc binding site while the N-terminal domain contains the acceptor binding site and likely membrane association site. Combined with sequence data from other MurG homologs, this structure provides insight into the residues that are important in substrate binding and catalysis. We have also noted that a conserved region found in many UDP-sugar transferases maps to a beta/alpha/beta/alpha supersecondary structural motif in the donor binding region of MurG, an observation that may be helpful in glycosyltransferase structure prediction. The identification of a conserved structural motif involved in donor binding in different UDP-sugar transferases also suggests that it may be possible to identify--and perhaps alter--the residues that help determine donor specificity.
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Lau YL, Chan LC, Chan YY, Ha SY, Yeung CY, Waye JS, Chui DH. Prevalence and genotypes of alpha- and beta-thalassemia carriers in Hong Kong -- implications for population screening. N Engl J Med 1997; 336:1298-301. [PMID: 9113933 DOI: 10.1056/nejm199705013361805] [Citation(s) in RCA: 162] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND The thalassemias are common in southern China. We determined the prevalence of heterozygous carriers of these genetic disorders in Hong Kong and assessed the feasibility of a community-based screening program. METHODS An educational and screening program for the thalassemias was carried out in three high schools with a total of 2420 students. Seventy-five percent of the students agreed to undergo screening, which consisted of blood counts, hemoglobin electrophoresis, serum ferritin measurements, and DNA analyses. RESULTS Of the 1800 blood samples tested, 150 (8.3 percent) had microcytosis (mean corpuscular volume, <80 microm3). Ninety students (5.0 percent) were carriers of alpha-thalassemia, of whom 81 (4.5 percent) were carriers of the Southeast Asian type of deletion, in which both alpha-globin genes on the same chromosome 16 are deleted. Sixty-one students (3.4 percent) were carriers of either beta-thalassemia or the mutation coding for hemoglobin E. Six students were carriers of both alpha- and beta-thalassemias. On the basis of these figures, the estimated numbers of pregnancies in Hong Kong in which the fetus is at risk for homozygous alpha-thalassemia and beta-thalassemia major or intermedia are 145 and 80 per year, respectively. In Hong Kong the actual numbers of women referred for prenatal diagnoses of these disorders are approximately 95 and 40 per year, respectively. CONCLUSIONS Despite the availability of hospital-based screening and prenatal diagnosis for many years in Hong Kong, many women carrying fetuses at risk for thalassemia are not referred for genetic counseling. A community-based program of education, screening, and counseling is needed in Hong Kong and southern China.
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Chen FE, Ooi C, Ha SY, Cheung BM, Todd D, Liang R, Chan TK, Chan V. Genetic and clinical features of hemoglobin H disease in Chinese patients. N Engl J Med 2000; 343:544-50. [PMID: 10954762 DOI: 10.1056/nejm200008243430804] [Citation(s) in RCA: 156] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Normally, one pair of each of the two alpha-globin genes, alpha1 and alpha2, resides on each copy of chromosome 16. In hemoglobin H disease, three of these four alpha-globin genes are affected by a deletion, a mutation, or both. We studied the alpha1-globin gene abnormalities and the clinical and hematologic features of Chinese patients with hemoglobin H disease in Hong Kong. METHODS We assessed the clinical features, hematologic values, serum ferritin levels, and liver function of 114 patients with hemoglobin H disease. We also performed echocardiography and magnetic resonance imaging of the liver and examined the two pairs of alpha-globin genes. RESULTS Hemoglobin H disease in 87 of the 114 patients (76 percent) was due to the deletion of three of the four alpha-globin genes (--/-alpha), a combination termed the deletional type of hemoglobin H. The remaining 27 patients (24 percent) had the nondeletional type of hemoglobin H disease, in which two alpha-globin genes are deleted and a third is mutated (--/alphaalphaT). All 87 patients with the deletional type of hemoglobin H were double heterozygotes in whom there was a deletion of both alpha-globin genes from one chromosome, plus a deletion of the alpha1 or alpha2 gene from the other chromosome (--/alpha- or --/-alpha). A variety of mutated alpha-globin genes was found in the patients with nondeletional type of hemoglobin H disease. Patients with the nondeletional type of the H disease had more symptoms at a younger age, more severe hemolytic anemia, and larger spleens and were more likely to require transfusions than patients with deletional hemoglobin H disease. The severity of iron overload was not related to the genotype. CONCLUSIONS Chinese patients in Hong Kong with the nondeletional type of hemoglobin H disease have more severe disease than those with the deletional type of the disease. Iron overload is a major cause of disability in both forms of the disease.
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Abstract
OBJECTIVE To characterize an unusual mode of presentation of systemic lupus erythematosus: acute and severe pancytopenia related to reactive hemophagocytosis. DESIGN Retrospective case series. SETTING Two general community hospitals in Hong Kong. PATIENTS Six patients presenting with a reactive hemophagocytic syndrome, identified over a 3.5 year period, diagnosed with systemic lupus erythematosus according to the criteria of the American Rheumatism Association. RESULTS In addition to severe pancytopenia and marrow hemophagocytosis, other characteristic features were fever, hypocomplementemia, high antinuclear antibody titer, and cutaneous and visceral vasculitis. There was no evidence of an underlying infection. The pancytopenia responded dramatically to treatment with steroids. CONCLUSION Recognition of the acute lupus hemophagocytic syndrome and distinction from an infection-associated hemophagocytic syndrome is important because it responds well to steroid therapy. The evaluation of patients presenting with a hemophagocytic syndrome should include serologic tests for systemic lupus erythematosus.
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Abstract
BACKGROUND Increased iron store has been linked to risk of cardiovascular disease. Structural alterations of arteries in beta-thalassemia major patients and in vitro functional disturbance of vascular endothelial cells by thalassemic serum have been described. We sought to determine whether arterial stiffness and endothelial function are altered in vivo. METHODS AND RESULTS Thirty thalassemia patients (16 male) aged 22.2+/-7.4 years were recruited. Left ventricular (LV) mass and function were assessed echocardiographically. Carotid and brachioradial artery stiffness was assessed by stiffness index and pulse-wave velocity (PWV), respectively. Brachial artery endothelial function was assessed by vascular response to reactive hyperemia (flow-mediated dilation [FMD]) and sublingual glyceryl trinitrate. These indexes were compared with those of 30 age- and sex-matched controls. None of the patients had LV systolic or diastolic dysfunction. When compared with controls, patients had greater absolute (113.8+/-38.0 versus 109.0+/- 32.6 g, P=0.04) and indexed (82.4+/-17.5 versus 66.7+/-12.7 g/m(2), P<0.001) LV mass, carotid artery stiffness index (8.1+/-3.5 versus 5.5+/-1.6, P<0.001), and brachioradial PWV (8.9+/-2.4 versus 7.9+/-1.7 m/s, P= 0.03). Their FMD was impaired (3.5+/-3.3% versus 8.8+/-3.9%, P<0.001), whereas glyceryl trinitrate- mediated dilation was preserved (17.9+/-7.6% versus 16.3+/-6.1%, P=0.40). Both stiffness index and PWV correlated inversely with magnitude of FMD (r=-0.40, P=0.03; r=-0.41, P=0.03) and positively with indexed LV mass (r=0.50, P=0.005; r=0.40, P=0.027). Nonetheless, no significant correlation existed between ferritin level and carotid stiffness, PWV, or FMD. CONCLUSIONS Increased arterial stiffness, endothelial dysfunction, and LV hypertrophy occur in patients with beta-thalassemia major, which may result in reduction of mechanical efficiency of the heart.
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Alexander FE, Chan LC, Lam TH, Yuen P, Leung NK, Ha SY, Yuen HL, Li CK, Li CK, Lau YL, Greaves MF. Clustering of childhood leukaemia in Hong Kong: association with the childhood peak and common acute lymphoblastic leukaemia and with population mixing. Br J Cancer 1997; 75:457-63. [PMID: 9020498 PMCID: PMC2063384 DOI: 10.1038/bjc.1997.77] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Incidence data of childhood leukaemia (CL) in Hong Kong (1984-90) have been analysed for evidence of variation between small areas. All cases (n=261) were classified by morphological cell type, with the majority (n=205) being acute lymphoblastic leukaemia (ALL), and haematological review has permitted immunophenotypic classification for 73% of these. The data have been examined for evidence of spatial clustering within small census areas (TPUs) and for association with population mixing, with attention focused on those subgroups (especially the childhood peak of ALL--taken here to be diagnoses in children from 24 months up to the seventh birthday--and common ALL) which, it has been hypothesized, may be caused by unusual patterns of exposure and response to common infections. For the whole of Hong Kong, there was evidence of spatial clustering of ALL at ages 0-4 years (P = 0.09) and in the childhood peak (P<0.05). When these analyses were restricted to TPUs where extreme population mixing may have occurred, overall incidence was elevated and significant evidence of clustering was found for ALL (P<0.007) at these ages and for the common ALL in the childhood peak (P = 0.032). Replication of the analyses for subsets of leukaemia that were not dominated by the childhood peak of ALL found no evidence of clustering. This is the first investigation of an association between population mixing and childhood leukaemia in Asia and the first to include clustering and to consider particular subsets. The results are supportive of the 'infectious' aetiology hypothesis for subsets of childhood leukaemia, specifically common ALL in the childhood peak.
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Cheuk DKL, Wang P, Lee TL, Chiang AKS, Ha SY, Lau YL, Chan GCF. Risk factors and mortality predictors of hepatic veno-occlusive disease after pediatric hematopoietic stem cell transplantation. Bone Marrow Transplant 2007; 40:935-44. [PMID: 17768390 DOI: 10.1038/sj.bmt.1705835] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
A cohort of 138 children with 144 hematopoietic stem cell transplantation (HSCT) performed in 1997-2006 were analyzed to evaluate risk factors and mortality predictors of hepatic veno-occlusive disease (VOD). Nineteen patients (13.2%) developed VOD (nine boys, median age 3.5 years) at 1-21 days after HSCT (median 13 days). Age < or =2 years at transplant (odds ratio (OR)=5.25, P=0.011), BU-CY conditioning (OR=5.16, P=0.001), thalassemia major (OR=3.97, P=0.015), platelet engraftment beyond day +21 (OR=8.67, P=0.025) were univariate risk factors for VOD. The first two remained significant in multivariate regression. Seven patients (36.8%) with VOD died, at a median of 44 days post transplant (range, 30-421 days). The 5-year survival was 62%. All surviving patients had normal liver function on follow-up at 0.5-9 years. Patients with VOD had higher 100-day mortality (16.3 vs 9.6%, P=0.024). Mortality predictors included donors other than autologous or matched sibling (hazard ratio (HR)=23.6, P=0.006), hepatic and cutaneous GVHD (HR=8.15, P=0.038), maximal weight gain >9% (HR=6.81, P=0.023), pleural effusion, intensive care unit admission, peak bilirubin >300 micromol l(-1) (HR=13.6, P=0.016), day +21 bilirubin >200 micromol l(-1) (HR=33.9, P=0.001), and rise of bilirubin >15 micromol l(-1) per day within the first week (HR=19.8, P=0.006). Mortality was substantially higher if >3 predictors were present (HR=33.9, P=0.001). Meticulous monitoring in high-risk patients and early treatment should be considered before VOD progresses beyond salvage.
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Journal Article |
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Ma SK, Wan TS, Cheuk AT, Fung LF, Chan GC, Chan SY, Ha SY, Chan LC. Characterization of additional genetic events in childhood acute lymphoblastic leukemia with TEL/AML1 gene fusion: a molecular cytogenetics study. Leukemia 2001; 15:1442-7. [PMID: 11516105 DOI: 10.1038/sj.leu.2402202] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2000] [Accepted: 05/02/2001] [Indexed: 11/09/2022]
Abstract
TEL/AML1 gene fusion that results from a cryptic t(12;21) is the most common genetic aberration in childhood B-lineage acute lymphoblastic leukemia (ALL). While the translocation may initiate the leukemic process, critical secondary genetic events are currently believed to be pivotal for leukemogenesis. We investigated 12 cases of childhood ALL with TEL/AML1 gene fusion by fluorescence in situ hybridization (FISH) and comparative genomic hybridization (CGH) and documented additional or secondary genetic changes in seven patients (58%). Three patients showed extra copies of chromosome 21 including a case in which the trisomy 21 (+21) clone was distinct from the one harboring TEL/AML1 gene fusion. Interestingly, one patient without +21 showed amplification of the AML1 gene on chromosome 21q, supporting the contention that AML1 amplification may be an important additional genetic event. Gene expression study by semi-quantitative reverse-transcription polymerase chain reaction (RT-PCR) in two of these four patients showed an increase in AML1 transcripts that paralleled the increase in gene copy number. Deletion of the normal TEL allele was detected in two patients, with one of them showing loss of chromosome 12 together with duplication of the der(12)t(12;21). Finally, one patient showed duplication of the fusion signal. Our findings confirm that additional or secondary genetic changes including AML1 amplification are commonly encountered in childhood ALL with TEL/AML1 gene fusion, which are envisaged to play significant roles in disease progression.
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Taneja S, MacGregor J, Markus S, Ha S, Mohr I. Enhanced antitumor efficacy of a herpes simplex virus mutant isolated by genetic selection in cancer cells. Proc Natl Acad Sci U S A 2001; 98:8804-8. [PMID: 11438715 PMCID: PMC37516 DOI: 10.1073/pnas.161011798] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Replication-competent, attenuated herpes simplex virus-1 (HSV-1) derivatives that contain engineered mutations into the viral gamma 34.5 virulence gene have been used as oncolytic agents. However, as attenuated mutants often grow poorly, they may not completely destroy some tumors and surviving cancer cells simply regrow. Thus, although HSV-1 gamma 34.5 mutants can reduce the growth of human tumor xenografts in mice and have passed phase I safety studies, their efficacy is limited because they replicate poorly in many human tumor cells. Previously, we selected for a gamma 34.5 deletion mutant variant that regained the ability to replicate efficiently in tumor cells. Although this virus contains an extragenic suppressor mutation that confers enhanced growth in tumor cells, it remains attenuated. Here, we demonstrate that the suppressor virus replicates to greater levels in prostate carcinoma cells and, importantly, is a more potent inhibitor of tumor growth in an animal model of human prostate cancer than the gamma 34.5 parent virus. Thus, genetic selection in cancer cells can be used as a tool to enhance the antitumor activity of a replication-competent virus. The increased therapeutic potency of this oncolytic virus may be useful in the treatment of a wide variety of cancers.
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Ha S, Andreani R, Robbins A, Muegge I. Evaluation of docking/scoring approaches: a comparative study based on MMP3 inhibitors. J Comput Aided Mol Des 2000; 14:435-48. [PMID: 10896316 DOI: 10.1023/a:1008137707965] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
An increasing number of docking/scoring programs are available that use different sampling and scoring algorithms. A reliable scoring function is the crucial element of such approaches. Comparative studies are needed to evaluate their current capabilities. DOCK4 with force field and PMF scoring as well as FlexX were used to evaluate the predictive power of these docking/scoring approaches to identify the correct binding mode of 61 MMP-3 inhibitors in a crystal structure of stromelysin and also to rank them according to their different binding affinities. It was found that DOCK4/PMF scoring performs significantly better than FlexX and DOCK4/FF in both ranking ligands and predicting their binding modes. Most notably, DOCK4/PMF was the only scoring/docking approach that found a significant correlation between binding affinity and predicted score of the docked inhibitors. However, comparing only those cases where the correct binding mode was identified (scoring highest among sampled poses), FlexX showed the best 'fine tuning' (lowest rmsd) in predicted binding modes. The results suggest that not so much the sampling procedure but rather the scoring function is the crucial element of a docking program.
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Comparative Study |
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Lau YL, Chan GC, Ha SY, Hui YF, Yuen KY. The role of phagocytic respiratory burst in host defense against Mycobacterium tuberculosis. Clin Infect Dis 1998; 26:226-7. [PMID: 9455564 DOI: 10.1086/517036] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
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Lau YL, Peiris M, Chan GC, Chan AC, Chiu D, Ha SY. Primary human herpes virus 6 infection transmitted from donor to recipient through bone marrow infusion. Bone Marrow Transplant 1998; 21:1063-6. [PMID: 9632282 DOI: 10.1038/sj.bmt.1701230] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
An 8.5-month-old boy with Wiskott-Aldrich syndrome received a sibling matched bone marrow transplant from his healthy non-identical twin brother. The donor had primary human herpes virus 6 (HHV-6) infection around the time of bone marrow donation. The recipient had hepatitis in the first week and then developed fever and rash on day 18. Skin biopsy was shown to have HHV-6 antigen and his peripheral blood leukocytes were HHV-6 DNA positive. He engrafted on day 18 but the ANC dropped from 5.5 x 10(9)/l (day 23) to 0.48 x 10(9)/l (day 34) with persistent HHV-6 DNAemia. Bone marrow on day 35 was positive for HHV-6 DNA. He was treated with G-CSF and ganciclovir with good response. He later had pneumonitis which was treated empirically with foscarnet, ceftazidime and clarithromycin.
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Case Reports |
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Lee KB, Lee JM, Park CY, Lee KB, Cho HY, Ha SY. What is the difference between squamous cell carcinoma and adenocarcinoma of the cervix? A matched case–control study. Int J Gynecol Cancer 2006; 16:1569-73. [PMID: 16884367 DOI: 10.1111/j.1525-1438.2006.00628.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The objective of this study was to investigate the efficacy of treatment strategies in patients with adenocarcinoma (AC) of the cervix and compare it with those with squamous cell carcinoma (SCC) of the cervix. Women with FIGO (1994) stage IB1 AC, especially pathologic tumor size of 2-4 cm, treated with class III hysterectomy, were compared with those with SCC treated with comparable strategy in a case-controlled study. Eighty patients (20 cases, 60 controls) were analyzed. Lymphvascular space invasion (P = 0.01) and lymph node metastasis (P = 0.07) were more frequent in patients with SCC than in those with AC. However, there was no significant difference in depth of stromal invasion (P = 0.51) and invasion of the parametrium (P = 0.44) between two groups. And there was also no statistically significant difference in disease-free survival (P = 0.86) and overall survival (P = 0.89) between two groups. Primary radical surgery followed by adjuvant therapy, same as for SCC, would be acceptable for AC with pathologic tumor size of 2-4 cm. Although it was difficult to determine whether AC recurred more systemically, more effective treatment strategies than those currently available for AC should be considered to reduce the systemic recurrence.
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Yuen KY, Woo PC, Liang RH, Chiu EK, Chen FF, Wong SS, Lau YL, Ha SY, Peiris JS, Siau H, Chan TK. Clinical significance of alimentary tract microbes in bone marrow transplant recipients. Diagn Microbiol Infect Dis 1998; 30:75-81. [PMID: 9554172 DOI: 10.1016/s0732-8893(97)00213-7] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
A prospective study on the microbes isolated from the alimentary tract in 120 bone marrow transplant (BMT) recipients (1991-1993) was undertaken to define the spectrum of organisms isolated under antimicrobial prophylaxis, their temporal sequence of emergence, and the associated morbidity and mortality. Clostridium difficile (n = 20), isolated in the pre-engraftment and early post-engraftment periods (day 2-45 post-BMT), was the most common microbe recovered from stool of patients with diarrhea. In contrast to previous reports, no significant difference in mortality was observed between patients with and without C. difficile isolated in stool. Two patients had neutropenic ileocecitis with concomitant bacteremia due to Escherichia coli and Klebsiella pneumoniae. One patient was found to have astrovirus gastroenteritis (day 7), and Giardia lamblia was recovered from the stool of another (day -7). Heavy growth of Staphylococcus aureus from direct smear-positive specimens was found from the upper airway of two patients with severe mucositis and complete dysphagia (day 12 and 23). Salmonella spp. of groups B and E were found in the stool of five asymptomatic patients at the time of conditioning. No specific organisms was recovered from the endoscopic brushing of two patients with lower end esophagitis, three patients with upper gastrointestinal bleeding, and three patients with perirectal cellulitis. During the post-engraftment period, five patients had documented cytomegalovirus gastroenterocolitis (days 34-97), one had Mycobacterium chelonae colitis (day 70), and another had nodular gastritis due to Acremonium falciforme (day 270). Overall, only 28% of patients with alimentary tract symptoms/syndrome had specific pathogens isolated from clinical specimens. Differentiation of the causation of alimentary tract symptoms was often difficult because noninfectious complications such as conditioning toxicity, graft-versus-host disease, and its treatment often caused alimentary tract symptoms in addition to predisposed BMT patient to infection. The reluctance of obtaining tissue biopsy for ascertaining the importance of those potential alimentary tract pathogens often dictate the use of empirical treatment.
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Kim JA, Ha S, Shin KY, Kim S, Lee KJ, Chong YH, Chang KA, Suh YH. Neural stem cell transplantation at critical period improves learning and memory through restoring synaptic impairment in Alzheimer's disease mouse model. Cell Death Dis 2015; 6:e1789. [PMID: 26086962 PMCID: PMC4669825 DOI: 10.1038/cddis.2015.138] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Revised: 04/05/2015] [Accepted: 04/22/2015] [Indexed: 12/20/2022]
Abstract
Alzheimer's disease (AD) is characterized by neuronal loss in several regions of the brain. Recent studies have suggested that stem cell transplantation could serve as a potential therapeutic strategy to halt or ameliorate the inexorable disease progression. However, the optimal stage of the disease for stem cell transplantation to have a therapeutic effect has yet to be determined. Here, we demonstrated that transplantation of neural stem cells into 12-month-old Tg2576 brains markedly improved both cognitive impairments and neuropathological features by reducing β-amyloid processing and upregulating clearance of β-amyloid, secretion of anti-inflammatory cytokines, endogenous neurogenesis, as well as synapse formation. In contrast, the stem cell transplantation did not recover cognitive dysfunction and β-amyloid neuropathology in Tg2576 mice aged 15 months when the memory loss is manifest. Overall, this study underscores that stem cell therapy at optimal time frame is crucial to obtain maximal therapeutic effects that can restore functional deficits or stop the progression of AD.
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Research Support, Non-U.S. Gov't |
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Cheuk DKL, Mok ASP, Lee ACW, Chiang AKS, Ha SY, Lau YL, Chan GCF. Quality of life in patients with transfusion-dependent thalassemia after hematopoietic SCT. Bone Marrow Transplant 2008; 42:319-327. [PMID: 18560410 DOI: 10.1038/bmt.2008.165] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2008] [Revised: 04/25/2008] [Accepted: 05/02/2008] [Indexed: 02/08/2023]
Abstract
In this cross-sectional study, we compared the quality of life (QOL) in transfusion-dependent thalassemic patients who survived matched sibling hematopoietic SCT (HSCT, n=24) with patients treated conventionally with transfusion and iron chelation (n=74). WHOQOL-BREF(HK) and PedsQL questionnaires were administered to patients aged >18 years and 5-12 years, respectively. Patients aged 12-18 years received both questionnaires. WHOQOL-BREF(HK) revealed post transplant patients rated overall health better than those treated conventionally (score 3.67 vs 3.06, P=0.01). They are less dependent on medical aids (3.87 vs 2.96, P=0.006), having higher activity level (4.00 vs 3.36, P=0.026) and better personal relationships (4.13 vs 3.69, P=0.014). Physical health domain score was better (75.20 vs 63.94, P=0.007). These differences remained significant after adjustment for comorbidities. PedsQL revealed post transplant patients rated better for running (3.53 vs 2.72, P=0.001) and sports (3.20 vs 2.64, P=0.038), even after adjustment for comorbidities, but were less satisfied for school absence to attend hospital (2.53 vs 3.29, P=0.03). Post transplant patients were significantly more likely to consider marriage (100 vs 75.7%, P=0.033), but not childbearing (66.7 vs 51.4%, P=0.28). In conclusion, transplanted thalassemic patients enjoy better QOL, mainly in physical health, compared with conventionally treated patients. This information is important to patients considering HSCT.
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Comparative Study |
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Chan LC, Ma SK, Chan AY, Ha SY, Waye JS, Lau YL, Chui DH. Should we screen for globin gene mutations in blood samples with mean corpuscular volume (MCV) greater than 80 fL in areas with a high prevalence of thalassaemia? J Clin Pathol 2001; 54:317-20. [PMID: 11304851 PMCID: PMC1731396 DOI: 10.1136/jcp.54.4.317] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AIMS To investigate whether it is worthwhile, in areas where thalassaemia is common, to screen for globin gene mutations in subjects with a mean corpuscular volume (MCV) above 80 fL, especially in partners of known thalassaemia carriers. METHODS Blood samples from 95 subjects with MCV between 80 and 85 fL were screened for the presence of alpha globin gene mutations and the haemoglobin (Hb) E mutation. RESULTS Thirty four subjects harboured globin gene mutations. Of these, 31 had deletions of one alpha globin gene, one had Hb Constant Spring, and three had Hb E mutations. CONCLUSION Based on the above figures and known prevalence rates of thalassaemia carriers, it would seem worthwhile to screen for globin gene mutations in partners of known thalassaemia carriers, regardless of MCV, to identify pregnancies at risk of Hb H disease or Hb E/beta thalassaemia.
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research-article |
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Yang DM, Yoon MH, Kim HS, Oh YH, Ha SY, Oh JH, Chung HS, Kim HS. Presacral epidermoid cyst: imaging findings with histopathologic correlation. ABDOMINAL IMAGING 2001; 26:79-82. [PMID: 11116367 DOI: 10.1007/s002610000118] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND The aim of this study was to determine the imaging characteristics of presacral epidermoid cysts and correlate the imaging findings with the histopathologic findings. METHODS We retrospectively reviewed sonographic, computed tomographic, and magnetic resonance examinations in four consecutive patients with a pathologically proven presacral epidermoid cyst. Imaging findings of the presacral epidermoid cyst were correlated with the histopathologic findings. RESULTS In all four patients, sonography showed a presacral mass with a heterogeneous low echogenicity, and computed tomography showed a discrete well-defined hypodense presacral mass with a thin wall. In the three patients who underwent magnetic resonance imaging, the mass showed a heterogeneous low signal intensity on the T1-weighted image and a high signal intensity with multiple small foci of low signal intensity in the nondependent portion of the mass on the T2-weighted image. These imaging findings correlated well with the pathologic results. Aggregates of keratinous material contributed to these imaging findings. CONCLUSION In the diagnosis of the presacral epidermoid cyst, sonographic and magnetic resonance imaging findings may be helpful.
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Chung M, Ha S, Jeong S, Bok J, Cho K, Baik M, Choi Y. Cloning and characterization of bovine stearoyl CoA desaturasel cDNA from adipose tissues. Biosci Biotechnol Biochem 2000; 64:1526-30. [PMID: 10945276 DOI: 10.1271/bbb.64.1526] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Two overlapping cDNA clones have been isolated from bovine adipose tissue by the reverse-transcription-polymerase chain reaction (RT-PCR) method. The combined sequence of the two clones was 1039 bp in length and encoded 345 amino acids. The deduced amino acid sequence of the clones showed 96.5% similarity to that of sheep SCD and more than 88% similarities to other mammalian SCD1s, indicating that the clones are the cDNAs for the bovine SCD1. The transcript size of the bovine SCD1 was about 4.9 kb, the message was detected in the bovine adipose tissues but not in the liver. Female cattle expressed threefold higher levels of SCD1 mRNA than male animals.
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Shehata N, Austin T, Ha S, Timmerman K. Barriers to and facilitators of hepatitis C virus screening and testing: A scoping review. CANADA COMMUNICABLE DISEASE REPORT = RELEVE DES MALADIES TRANSMISSIBLES AU CANADA 2018; 44:166-172. [PMID: 31011297 PMCID: PMC6449117 DOI: 10.14745/ccdr.v44i78a03] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
BACKGROUND As part of the global effort to eliminate hepatitis C virus (HCV), it is important to understand the barriers to and facilitators of HCV screening and testing. OBJECTIVE To examine the barriers and facilitators experienced by health care providers offering HCV screening and testing and patients seeking HCV testing. METHODS A literature search was conducted using Embase, Medline and Scopus databases to collect studies published between January 2012 and July 2017. We extracted the following data: author, year of publication, study design, population, setting, country, method of data collection, and knowledge and awareness outcomes. RESULTS A total of 16 articles were identified. Barriers to HCV screening and testing among patients included low self-perceived risk of acquiring HCV, perceived stigma and fear of a positive result. Facilitators of HCV screening and testing, as reported by patients, included increased knowledge of transmission and manifestations of HCV infection and having HCV testing included as part of routine care with or without HIV testing. Barriers to offering HCV screening and testing included time constraints, lack of specific knowledge about HCV and discomfort in asking about risk behaviours. Facilitators of offering HCV screening and testing included testing reminders and working in locations with a higher HCV caseload. CONCLUSION Lack of knowledge and fear of stigma and discrimination remain barriers to HCV testing at the patient level and lack of time, knowledge and discomfort in asking about risk behaviours remain barriers to offering HCV testing by health care providers. This identifies potential areas for future public health action.
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Scoping Review |
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Ooi GC, Khong PL, Chan GCF, Chan KN, Chan KL, Lam W, Ng I, Ha SY. Magnetic resonance screening of iron status in transfusion-dependent β-thalassaemia patients. Br J Haematol 2004; 124:385-90. [PMID: 14717788 DOI: 10.1046/j.1365-2141.2003.04772.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The clinical utility of dual sequence (T1- and T2-weighted) magnetic resonance (MR) imaging in estimating liver iron concentration (LIC) in 32 transfusion-dependent beta-thalassaemia major (24 females; age 18.5+/-5.9 years) patients on desferrioxamine was evaluated. Signal intensity ratios (SIR) between liver, spleen and pancreas to psoas muscle were determined on both sequences. Relationships between clinical and MR parameters, and accuracy of SIR thresholds in determining adequacy of chelation from LIC were analysed. Liver T1- and T2-SIR were related to LIC (P < 0.001). T1-SIR < 0.60 predicted severe iron overload (LIC > 15 mg/g) with sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 100%, 87%, 33% and 100% respectively. T2-SIR < 0.1 yielded 100% sensitivity, 93% specificity, 50% PPV and 100% NPV. T1-SIR > or = 1.1 predicted LIC < 7 mg/g with 69% sensitivity, 88% specificity, 85% PPV and 74% NPV. T2-SIR > or = 0.20 yielded 56.5% sensitivity, 94% specificity, 90% PPV and 71% NPV. LIC correlated with liver T1-SIR, liver T2-SIR and serum ferritin (r = -0.76, -0.65, 0.47, respectively; P < 0.01). Serum ferritin was inversely related to liver T1-SIR, liver T2-SIR and spleen T2-SIR (r = -0.35, -0.43, -0.40, respectively; P < 0.05). Mean total transfusion burden was not related to any MR parameter. Although neither MR sequence was a highly accurate predictor of LIC, SIR thresholds are useful to determine presence of iron overload and adequacy of chelation treatment.
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Ho HK, Ha SY, Lam CK, Chan GC, Lee TL, Chiang AK, Lau YL. Alloimmunization in Hong Kong southern Chinese transfusion-dependent thalassemia patients. Blood 2001; 97:3999-4000. [PMID: 11405212 DOI: 10.1182/blood.v97.12.3999] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Letter |
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39 |
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Zhang XS, Ha S, Wang XL, Shi YL, Duan SS, Li ZA. Tanshinone IIA protects dopaminergic neurons against 6-hydroxydopamine-induced neurotoxicity through miR-153/NF-E2-related factor 2/antioxidant response element signaling pathway. Neuroscience 2015; 303:489-502. [PMID: 26116522 DOI: 10.1016/j.neuroscience.2015.06.030] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Revised: 05/23/2015] [Accepted: 06/17/2015] [Indexed: 12/30/2022]
Abstract
Parkinson's disease (PD) is the second most common progressive neurodegenerative disorder with increased oxidative stress, the underlying vital process contributing to cell death. Tanshinone IIA (Tan IIA), a major bioactive diterpene quinone of Salva miltiorrhiza, had been proved effective in the MPTP model through its anti-inflammatory activity. Here in this research, we found that Tan IIA prevented the loss of nigrostriatal dopaminergic neurons by activating the NF-E2-related factor 2 (Nrf2)-antioxidant response element (ARE) pathway. The cytotoxicity of 6-hydroxydopamine (6-OHDA) was attenuated by the treatment of Tan IIA in SH-SY5Y cells, which significantly reduced 6-OHDA-induced lactic dehydrogenase release and reactive oxygen species production. Further study indicated that Tan IIA contributed to the nuclear accumulation of Nrf2, which bound to the ARE sequence, and activated ARE-regulated genes, including heme oxygenase-1, glutamate cysteine ligase catalytic subunit (GCLC) and glutamate cysteine ligase modifier subunit (GCLM). Tan IIA also protected against damage to mitochondrial membrane potential, reduced the translocation of cytochrome c from the mitochondria to the cytoplasm and the activation of Caspase-9 and Caspase-3. Moreover, we demonstrated the above effects were performed in Nrf2-dependent manner. Further studies revealed that Tan IIA reduced the enhancement of miR-153 by 6-OHDA, which targeted the 3'-UTR of Nrf2, and suppressed its expression and activation. Additionally, neurodegeneration caused by in vivo stereotaxic injection of 6-OHDA could also be ameliorated by the administration of Tan IIA. Taken together, our results strongly suggest that Tan IIA may be beneficial for the treatment of PD, and also confirm that targeting the Nrf2/ARE pathway is a promising strategy for therapeutic intervention in PD.
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Research Support, Non-U.S. Gov't |
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38 |