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Pan J, Tan YH, Zhao JX, Chen XH, Xu ZF, Xu J, Chang JM, Xue F, Zhang N, Ren FG, Zhang YF, Wang XJ, Wang HW. [Discovery of a novel spliceosome of ABL gene (ABL(Δexon7+35INS)) and its association with TKIs resistance in chronic myeloid leukemia]. ZHONGHUA XUE YE XUE ZA ZHI = ZHONGHUA XUEYEXUE ZAZHI 2016; 37:503-6. [PMID: 27431076 PMCID: PMC7348335 DOI: 10.3760/cma.j.issn.0253-2727.2016.06.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
OBJECTIVE To explore whether the ABL(Δexon7) and ABL(35INS) spliceosome contributed to TKIs resistance. METHODS Screening ABL(Δexon7) and ABL(35INS) in 74 normal people and 76 CML patients (53 patients in remission and 23 patients with TKIs resistance) by using polyacrylamide gel electrophoresis combined with cloning sequencing. RESULTS A novel spliceosome ABL(Δexon7+ 35INS) (ABL(Δexon7) and ABL(3)5INS existed at the same time) was identified and the mutation was detected in 8 (10.8%) of 74 normal people, 4 (7.5%) of 53 remission patients and 2 (8.7%) of 23 resistant patients. While 47 (63.5%) cases expressed ABL(Δexon7) and 8 (10.8% ) cases expressed ABL(35INS) in 74 healthy people, 30 (56.6%) cases expressed ABL(Δexon7) and 5 (9.4% ) cases expressed ABL(35INS) in 53 remission patients, 12 (52.2%) cases expressed ABL(Δexon7) and 3(13.0%) cases expressed ABL(35INS) in 23 resistant patients. Three kinds of spliceosome in all groups had no statistical difference. CONCLUSION ABL(Δexon7+ 35INS), ABL(Δexon7) and ABL(35INS) may be not uncommon in ABL gene and were unrelated to resistance in CML with TKIs treatment. ABL(35INS) were often accompanying with exon 7 deletion.
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Li L, Qi XL, Chen XH, Ren FG, Xu ZF, Tan YH, Yang SY, Pan J, Xu J, Li J, Wang HW. Identification of RUNX1 gene breakage and copy number variation in acute myeloid leukemia. Int J Lab Hematol 2015; 38:e23-6. [PMID: 26696592 DOI: 10.1111/ijlh.12452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Yao X, Goodale UM, Li ZL, Huang Y, Wang XF, Cheng FY, Tan YH, Xiao CF, Lan QY. Relative importance of seed drying rate, desiccation tolerance, and cryotolerance for the conservation of Ardisia elliptica, A. brunnescens and A. virens. CRYO LETTERS 2014; 35:162-170. [PMID: 24997833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
BACKGROUND The pan-tropical genus Ardisia has more than 400 species and is of high horticultural and medicinal value. Due to overexploitation it is important to conserve the germplasm of this genus. OBJECTIVE To investigate the feasibility and methods of cryopreservation for long-term seed storage of three Ardisia species: A. elliptica Thunb., A. brunnescens Walker, and A. virens Kurz. METHODS We tested whether rapid desiccation can increase desiccation tolerance and cryotolerance, and whether the thawing rate can affect cryopreservation success. Seeds were subjected to three desiccation treatments: 1) activated silica gel at 25 +/- 2 degree C, and 4% relative humidity (RH); 2) saturated NaCl solution in closed jars in 25 +/- 2 degree C and 75% RH; and 3) air-drying at room conditions at 27 +/- 2 degree C and RH 60% for different desiccation durations (12h, 24h, 48h, 96h, and 196h). Seeds were then assessed for desiccation tolerance and cryotolerance after rapid thawing (direct immersion in 36 degree C water bath for 2 min) or slow thawing (at 27°C for 1 h). RESULTS For all three species, desiccation method and duration significantly affected cryotolerance (P < 0.0001). Fast desiccation did not improve germination compared to slower desiccation (P < 0.01). Whereas A. elliptica germination was unaffected by desiccation duration, drying time significantly (P < 0.0001) affected germination percentage in the other two species especially after 48h. Although slow thawing improved cryotolerance of A. brunnescens seeds (P < 0.05), there was no significant effect of thawing rate on A. elliptica. A. virens seed did not survive cryopreservation. CONCLUSIONS Cryopreservation protocols of Ardisia species may be species-specific and should be established for each species in the genus so that cryopreservation can be used as a successful conservation strategy.
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Gan VHL, Wan WK, Tan YH. Myxoid perineurioma in a transplanted kidney. Transplant Proc 2014; 46:286-9. [PMID: 24507070 DOI: 10.1016/j.transproceed.2013.09.030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Revised: 09/17/2013] [Accepted: 09/26/2013] [Indexed: 01/01/2023]
Abstract
Perineuriomas are rare, benign peripheral nerve sheath tumors, most commonly found in the extremities and trunks. A handful of cases have been reported to arise from the retroperitoneum and in kidneys. To our knowledge, this is the first reported case of a myxoid perineurioma arising from a transplanted kidney. The patient is a 40-year-old Chinese male with end-stage kidney disease secondary to chronic sclerosing glomerulonephritis. He has a nonfunctioning renal graft in his right iliac fossa and a functioning graft in the left. Routine imaging found a mass in the nonfunctioning graft which was increasing in size. He underwent graft nephrectomy and histology revealed a myxoid perineurioma with no atypical features or malignancy.
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Naderali N, Nejat N, Tan YH, Vadamalai G. First Report of Two Distinct Phytoplasma Species, 'Candidatus Phytoplasma cynodontis' and 'Candidatus Phytoplasma asteris,' Simultaneously Associated with Yellow Decline of Wodyetia bifurcata (Foxtail Palm) in Malaysia. PLANT DISEASE 2013; 97:1504. [PMID: 30708488 DOI: 10.1094/pdis-04-13-0412-pdn] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The foxtail palm (Wodyetia bifurcata), an Australian native species, is an adaptable and fast-growing landscape tree. The foxtail palm is most commonly used in landscaping in Malaysia. Coconut yellow decline (CYD) is the major disease of coconut associated with 16SrXIV phytoplasma group in Malaysia (1). Symptoms consistent with CYD, such as severe chlorosis, stunting, general decline, and death were observed in foxtail palms from the state of Selangor in Malaysia, indicating putative phytoplasma infection. Symptomatic trees loses their green and vivid appearance as a decorative and landscape ornament. To determine the presence of phytoplasma, samples were collected from the fronds of 12 symptomatic and four asymptomatic palms in September 2012, and total DNA was extracted using the CTAB method (3). Phytoplasma DNA was detected in eight symptomatic palms using nested PCR with universal phytoplasma 16S rDNA primer pairs, P1/P7 followed by R16F2n/R16R2 (2). Amplicons (1.2 kb in length) were generated from symptomatic foxtail palms but not from symptomless plants. Phytoplasma 16S rDNAs were cloned using a TOPO TA cloning kit (Invitrogen). Several white colonies from rDNA PCR products amplified from one sample with R16F2n/R16R2 were sequenced. Phytoplasma 16S rDNA gene sequences from single symptomatic foxtail palms showed 99% homology with a phytoplasma that causes Bermuda grass white leaf (AF248961) and coconut yellow decline (EU636906), which are both members of the 16SrXIV 'Candidatus Phytoplasma cynodontis' group. The sequences also showed 99% sequence identity with the onion yellows phytoplasma, OY-M strain, (NR074811), from the 'Candidatus Phytoplasma asteris' 16SrI-B subgroup. Sequences were deposited in the NCBI GenBank database (Accession Nos. KC751560 and KC751561). Restriction fragment length polymorphism (RFLP) analysis was done on nested PCR products produced with the primer pair R16F2n/R16R2. Amplified products were digested separately with AluI, HhaI, RsaI, and EcoRI restriction enzymes based on manufacturer's specifications. RFLP analysis of 16S rRNA gene sequences from symptomatic plants revealed two distinct profiles belonging to groups 16SrXIV and 16SrI with majority of the 16SrXIV group. RFLP results independently corroborated the findings from DNA sequencing. Additional virtual patterns were obtained by iPhyclassifier software (4). Actual and virtual patterns yielded identical profiles, similar to the reference patterns for the 16SrXIV-A and 16SrI-B subgroups. Both the sequence and RFLP results indicated that symptoms in infected foxtail palms were associated with two distinct phytoplasma species in Malaysia. These phytoplasmas, which are members of two different taxonomic groups, were found in symptomatic palms. Our results revealed that popular evergreen foxtail palms are susceptible to and severely affected by phytoplasma. To our knowledge, this is the first report of a mixed infection of a single host, Wodyetia bifurcata, by two different phytoplasma species, Candidatus Phytoplasma cynodontis and Candidatus Phytoplasma asteris, in Malaysia. References: (1) N. Nejat et al. Plant Pathol. 58:1152, 2009. (2) N. Nejat et al. Plant Pathol. J. 9:101, 2010. (3) Y. P. Zhang et al. J. Virol. Meth. 71:45, 1998. (4) Y. Zhao et al. Int. J. Syst. Evol. Microbiol. 59:2582, 2009.
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Amenomori M, Bi XJ, Chen D, Chen TL, Chen WY, Cui SW, Ding LK, Feng CF, Feng Z, Feng ZY, Gou QB, Guo YQ, Hakamada K, He HH, He ZT, Hibino K, Hotta N, Hu H, Hu HB, Huang J, Jia HY, Jiang L, Kajino F, Kasahara K, Katayose Y, Kato C, Kawata K, Le GM, Li AF, Li HJ, Li WJ, Liu C, Liu JS, Liu MY, Lu H, Meng XR, Mizutani K, Munakata K, Nanjo H, Nishizawa M, Ohnishi M, Ohta I, Onuma H, Ozawa S, Qian XL, Qu XB, Saito T, Saito TY, Sakata M, Sako TK, Shao J, Shibata M, Shiomi A, Shirai T, Sugimoto H, Takita M, Tan YH, Tateyama N, Torii S, Tsuchiya H, Udo S, Wang H, Wu HR, Xue L, Yamamoto Y, Yang Z, Yasue S, Yuan AF, Yuda T, Zhai LM, Zhang HM, Zhang JL, Zhang XY, Zhang Y, Zhang Y, Zhang Y, Zhou XX. Probe of the solar magnetic field using the "cosmic-ray shadow" of the sun. PHYSICAL REVIEW LETTERS 2013; 111:011101. [PMID: 24027782 DOI: 10.1103/physrevlett.111.011101] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We report on a clear solar-cycle variation of the Sun’s shadow in the 10 TeV cosmic-ray flux observed by the Tibet air shower array during a full solar cycle from 1996 to 2009. In order to clarify the physical implications of the observed solar cycle variation, we develop numerical simulations of the Sun’s shadow, using the potential field source surface model and the current sheet source surface (CSSS) model for the coronal magnetic field. We find that the intensity deficit in the simulated Sun’s shadow is very sensitive to the coronal magnetic field structure, and the observed variation of the Sun’s shadow is better reproduced by the CSSS model. This is the first successful attempt to evaluate the coronal magnetic field models by using the Sun’s shadow observed in the TeV cosmic-ray flux.
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Yazdani D, Zainal Abidin MA, Tan YH, Kamaruzaman S. Molecular identification of Aspergillus and Eurotium species isolated from rice and their toxin-producing ability. MIKROBIOLOGIIA 2011; 80:707-713. [PMID: 22168015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Thirty milled rice samples were collected from retailers in 4 provinces of Malaysia. These samples were evaluated for Aspergillus spp. infection by direct plating on malt extract salt agar (MESA). All Aspergillus holomorphs were isolated and identified using nucleotide sequences of ITS 1 and ITS 2 of rDNA. Five anamorphs (Aspergillus flavus, A. oryzae, A. tamarii, A. fumigatus and A. niger) and 5 teleomorphs (Eurotium rubrum, E. amstelodami, E. chevalieri, E. cristatum and E. tonophilum) were identified. The PCR-sequencing based technique for sequences of ITS 1 and ITS 2 is a fast technique for identification of Aspergillus and Eurotium species, although it doesn't work flawlessly for differentiation of Eurotium species. All Aspergillus and Eurotium isolates were screened for their ability to produce aflatoxin and ochratoxin A (OTA) by HPLC and TLC techniques. Only A. flavus isolate UPM 89 was able to produce aflatoxins B1 and B2.
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Ngeow JYY, Quek RHH, Ng DCE, Hee SW, Tao M, Lim LC, Tan YH, Lim ST. High SUV uptake on FDG-PET/CT predicts for an aggressive B-cell lymphoma in a prospective study of primary FDG-PET/CT staging in lymphoma. Ann Oncol 2009; 20:1543-1547. [PMID: 19474116 DOI: 10.1093/annonc/mdp030] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Data assessing the role of positron emission tomography (PET)/computed tomography (CT) imaging in lymphoma staging is still being accumulated and current staging is based primarily on CT. This study aims to compare the value of PET/CT over conventional CT and bone marrow biopsy (BMB) in the initial evaluation of patients with lymphoma. METHODS Data on 122 patients with PET/CT scans as part of their initial staging were prospectively collected and reviewed. All patients had complete staging, including BMB. RESULTS Among the 122 patients, 101 had non-Hodgkin's lymphoma (NHL) and 21 had Hodgkin's lymphoma (HL). Compared with conventional CT, PET/CT upstaged 21 (17%) cases [B-cell non-Hodgkin's lymphoma (B-NHL), 12; T-cell non-Hodgkin's lymphoma (T-NHL), 3; HL, 6]. Of significance, in 13 patients with 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG)-avid splenic lesions, four had normal CT findings. A maximum FDG uptake of >10 standardized uptake value (SUV) seems to significantly correlate with an aggressive B-cell lineage (odds ratio 2.47, 95% confidence interval 2.23-2.70). Overall, PET scan was concordant with BMB results in 108 (89%) and discordant in 14 (11%) cases. In HL, our data show that PET scan and marrow results agreed in 19 of the cases (90%), being concordantly negative in 18 cases and concordantly positive in one, giving a negative predictive value (NPV) of 100%, sensitivity of 100% and specificity of 90%. Of note, all 13 with early-stage HL had negative PET/CT scan and BMB. In NHL, all 17 cases of T-NHL had concordant PET and BMB results. In patients with aggressive B-NHL, BMB and PET/CT agreed in 58 patients (92%) and disagreed in five (8%), while the corresponding rates in indolent B-cell lymphoma were 14 (67%) and seven patients (33%), respectively. All seven were falsely negative. CONCLUSIONS PET/CT upstages 17% of cases and detects occult splenic involvement. This may have potential therapeutic and prognostic implications. SUV >10 may predict for an aggressive histology. Except for indolent B-NHL, our data show that PET scans have a good overall NPV in excluding lymphomatous bone marrow involvement. This is particularly true of early-stage HL, suggesting that BMB may be safely omitted in this group.
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Wong JFS, Ho HSS, Tan YH, Cheng CWS. Rare cause of intestinal obstruction after laparoscopic radical nephrectomy: internal herniation via a mesenteric defect. Urology 2008; 72:716.e13-4. [PMID: 18597821 DOI: 10.1016/j.urology.2007.12.028] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2007] [Revised: 12/07/2007] [Accepted: 12/10/2007] [Indexed: 12/11/2022]
Abstract
A 43-year-old man had painless macroscopic hematuria and was diagnosed with a 9-cm renal carcinoma in the lower pole of the left kidney. He underwent laparoscopic transperitoneal left radical nephrectomy (LRN) with an uneventful recovery. Eleven days later, he developed intestinal obstruction (IO). Abdominal computed tomography scan showed dilated small bowels occupying the left renal fossa. Laparotomy revealed closed-loop small bowel obstruction resulting from internal intestinal herniation via a 5-cm mesenteric defect. It was repaired after the herniated bowels were reduced. This case illustrates a rare cause of IO after LRN, in which mesenteric defect is necessary.
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Sim HG, Tan YH, Wong M. Contemporary results of endopyelotomy for ureteropelvic junction obstruction. ANNALS OF THE ACADEMY OF MEDICINE, SINGAPORE 2005; 34:179-83. [PMID: 15827665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
INTRODUCTION Endopyelotomy is an accepted treatment option for ureteropelvic junction obstruction (UPJO). In this study, we reviewed our 7-year experience with antegrade endopyelotomy for UPJO. MATERIALS AND METHODS We reviewed the records of 35 consecutive antegrade endopyelotomy for UPJO between 1996 and 2002. Patients were included if they had shown radiographic evidence of UPJO on diuresis urography or intravenous urogram with signs and symptoms or deterioration of renal function. RESULTS A total of 34 consecutive patients underwent 35 antegrade endopyelotomy procedures in 35 renal units. One patient had bilateral endopyelotomy for bilateral UPJO. Eighteen renal units (51%) had concomitant renal calculi that required percutaneous nephrolithotomy, including 8 renal units with pelvi-ureteric junction stones. Twenty-four renal units (69%) had moderate degree of hydronephrosis whilst 11 renal units (31%) had severe hydronephrosis. The mean operating time for antegrade endopyelotomy was 94 +/- 28 minutes and the mean hospital stay was 4.7 +/- 2.8 days. No patients had conversion to open pyeloplasty and no patient required perioperative blood transfusion. The mean followup was 33 +/- 23 months and the overall success rate following endopyelotomy was 83% (n = 29 renal units). The success rate for primary UPJO was 81%, whilst the success rate for secondary UPJO was 84%. Four renal units (11%) required ancillary procedures for failed endopyelotomy. Two patients required repeat endopyelotomy, and 2 patients needed open pyeloplasty. Two patients were lost to follow-up. CONCLUSION Endopyelotomy remains a viable approach for UPJO compared to open reconstruction. Careful patient selection can optimise the surgical outcome and minimise endopyelotomy failures.
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Dröes RM, Meiland FJM, Doruff C, Varodi I, Akkermans H, Baida Z, Faber E, Haaker T, Moelaert F, Kartseva V, Tan YH. A Dynamic Interactive Social Chart in Dementia CareAttuning Demand and Supply in the Care for Persons with Dementia and their Carers. Stud Health Technol Inform 2005; 114:210-20. [PMID: 15923777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
We-centric services may play an important role in the field of care and support for elderly persons with dementia and their carers. They may solve problems, such as fragmentation of care, gaps in the continuum of care and welfare services, and inefficient and uncustomized service delivery to patients and carers. In the FRUX Health Care pilot opportunities for we-centric, context-sensitive service bundles in the field of dementia care will be explored. The service on which we focus in this paper is a dynamic interactive social chart for dementia care (DEM-DISC). The feasibility of DEM-DISC will be investigated from a domain specific content perspective (needs, offerings, information and advice), an ICT perspective (ontology and application), a user perspective (persons with dementia, their carers and professionals/organizations), and an organisational perspective (necessary collaboration, governance and control, business modelling). A first demonstrator (validator) of the DEM-DISC will be designed, built and evaluated. Future possibilities to connect DEM-DISC to actual service delivery will be explored. In this paper we discuss the most important research questions from the different perspectives and the methods used to answer them.
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Tham KY, Tan YH, Loh OH, Tan WL, Ong MK, Tang HK. Psychiatric morbidity among emergency department doctors and nurses after the SARS outbreak. ANNALS OF THE ACADEMY OF MEDICINE, SINGAPORE 2004; 33:S78-9. [PMID: 15651222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
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Amenomori M, Ayabe S, Cui SW, Ding LK, Ding XH, Feng CF, Feng ZY, Gao XY, Geng QX, Guo HW, He HH, He M, Hibino K, Hotta N, Hu H, Hu HB, Huang J, Huang Q, Jia HY, Kajino F, Kasahara K, Katayose Y, Kato C, Kawata K, Le GM, Li JY, Lu H, Lu SL, Meng XR, Mizutani K, Mori S, Mu J, Munakata K, Nanjo H, Nishizawa M, Ohnishi M, Ohta I, Onuma H, Ouchi T, Ozawa S, Ren JR, Saito T, Sakata M, Sasaki T, Shibata M, Shiomi A, Shirai T, Sugimoto H, Takita M, Tan YH, Tateyama N, Torii S, Tsuchiya H, Udo S, Utsugi T, Wang BS, Wang H, Wang X, Wang YG, Wu HR, Xue L, Yamamoto Y, Yan CT, Yang XC, Yasue S, Ye ZH, Yu GC, Yuan AF, Yuda T, Zhang HM, Zhang JL, Zhang NJ, Zhang XY, Zhang Y, Zhou XX. Observation by an air-shower array in Tibet of the multi-TeV cosmic-ray anisotropy due to terrestrial orbital motion around the Sun. PHYSICAL REVIEW LETTERS 2004; 93:061101. [PMID: 15323615 DOI: 10.1103/physrevlett.93.061101] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2004] [Revised: 05/03/2004] [Indexed: 05/24/2023]
Abstract
We report on the solar diurnal variation of the galactic cosmic-ray intensity observed by the Tibet III air shower array during the period from 1999 to 2003. In the higher-energy event samples (12 and 6.2 TeV), the variations are fairly consistent with the Compton-Getting anisotropy due to the terrestrial orbital motion around the Sun, while the variation in the lower-energy event sample (4.0 TeV) is inconsistent with this anisotropy. This suggests an additional anisotropy superposed at the multi-TeV energies, e.g., the solar modulation effect. This is the highest-precision measurement of the Compton-Getting anisotropy ever made.
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Yip SKH, Tan YH, Cheng C, Sim HG, Lee YM, Chee C. Routine vascular control using the Hem-o-lok clip in laparoscopic nephrectomy: animal study and clinical application. J Endourol 2004; 18:77-81. [PMID: 15006060 DOI: 10.1089/089277904322836730] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND AND PURPOSE During laparoscopic nephrectomy (LPN), a stapling device is often used for vascular control, especially of the renal vein. Herein, we report our experience using a polymer clip (Hem-o-lok) for routine control of the vessels during LPN in the animal and clinical setting. PATIENTS AND METHODS Fifty ablative and fifteen live-donor nephrectomies were performed in domestic pigs. Hem-o-lok clips (10 mm; Weck Closure System, Research Triangle Park, NC) were routinely used for vascular control. In addition, from January 2001 to July 2002, 46 patients underwent hand-assisted laparoscopic (HAL) (N=40) or laparoscopic (N=6) nephrectomy for renal disease or donor nephrectomy. Venous control was achieved solely by the Hem-o-lok clips where at least two clips were applied on the patient side. Arterial control was obtained by the Hem-o-lok clips either alone or in combination with the metal clips. The technical difficulty in obtaining vascular control, transfusion requirement, and clinical outcome were evaluated. RESULTS In the animal study (total 65 nephrectomies), individual vascular control was obtained by the Hem-o-lok clip in all cases except two, where vascular injury during dissection necessitated endoscopic stapling of renal hilum or open conversion. The warm ischemic time for animal donor kidney harvest was uniformly <2 minutes. In the clinical study, arterial control was obtained mostly by a combination of Hem-o-lok and metal clips. Venous control using the Hem-o-lok was successful in all 46 cases without any slipping of clips or uncontrolled bleeding. The mean operating time was 148 minutes. No open conversion was required. The transfusion rate was 6.5% (N=3), with none of the transfusions being related to inadequacy of vascular control using the Hem-o-lok. Major complications included deep vein thrombosis and postoperative retroperitoneal hemorrhage (same patient) and acute respiratory distress syndrome (N = 1). The mean postoperative stay was 5.2 days (range 1-20 days). CONCLUSION The Hem-o-lok is a reliable and economical device for vascular control in laparoscopic renal surgery.
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Goh PY, Tan YJ, Lim SP, Tan YH, Lim SG, Fuller-Pace F, Hong W. Cellular RNA helicase p68 relocalization and interaction with the hepatitis C virus (HCV) NS5B protein and the potential role of p68 in HCV RNA replication. J Virol 2004; 78:5288-98. [PMID: 15113910 PMCID: PMC400326 DOI: 10.1128/jvi.78.10.5288-5298.2004] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Chronic infection by hepatitis C virus (HCV) can lead to severe hepatitis and cirrhosis and is closely associated with hepatocellular carcinoma. The replication cycle of HCV is poorly understood but is likely to involve interaction with host factors. In this report, we show that NS5B, the HCV RNA-dependent RNA polymerase (RdRp), interacts with a human RNA helicase, p68. Transient expression of NS5B alone, as well as the stable expression of all the nonstructural proteins in a HCV replicon-bearing cell line (V. Lohmann, F. Korner, J.-O. Koch, U. Herian, L. Theilmann, and R. Bartenschlager, Science 285:110-113), causes the redistribution of endogenous p68 from the nucleus to the cytoplasm. Deletion of the C-terminal two-thirds of NS5B (NS5BDeltaC) dramatically reduces its coimmunoprecipitation (co-IP) with endogenous p68, while the deletion of the N-terminal region (NS5BDeltaN1 and NS5BDeltaN2) does not affect its interaction with p68. In consistency with the co-IP results, NS5BDeltaC does not cause the relocalization of p68 whereas NS5BDeltaN1 does. With a replicon cell line, we were not able to detect a change in positive- and negative-strand synthesis when p68 levels were reduced using small interfering RNA (siRNA). In cells transiently transfected with a full-length HCV construct, however, the depletion (using specific p68 siRNA) of endogenous p68 correlated with a reduction in the transcription of negative-strand from positive-strand HCV RNA. Overexpression of NS5B and NS5BDeltaN1, but not that of NS5BDeltaC, causes a reduction in the negative-strand synthesis, indicating that overexpressed NS5B and NS5BDeltaN1 sequesters p68 from the replication complexes (thus reducing their replication activity levels). Identification of p68 as a cellular factor involved in HCV replication, at least for cells transiently transfected with a HCV expression construct, is a step towards understanding HCV replication.
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Tan YJ, Lim SP, Ting AE, Goh PY, Tan YH, Lim SG, Hong W. An anti-HIV-1 gp120 antibody expressed as an endocytotic transmembrane protein mediates internalization of HIV-1. Virology 2003; 315:80-92. [PMID: 14592761 DOI: 10.1016/s0042-6822(03)00514-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In this study, we used HIV-1 as a model to demonstrate a novel approach for receptor-independent cell entry of virus. The heavy chain of an anti-HIV-1 gp120 antibody was engineered with endocytotic and transmembrane motifs from either the cation-independent mannose 6-phosphate receptor or the low-density lipoprotein receptor. Flow cytometry and immunofluorescence studies showed that the chimeric antibodies were expressed on the cell surface and can undergo rapid internalization. Furthermore, one of the chimeric antibodies was able to bind and internalize HIV-1. Using a luciferase reporter HIV-1, we further showed that internalized viruses could undergo replication. Therefore, we have demonstrated a proof-of-principle of a novel method that can be used to internalize virus into cells, without prior knowledge of the cellular receptor for the virus. We propose that this approach would be particularly useful for studying viruses whose cellular receptor(s) is not known.
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Zhang T, Tan YH, Fu J, Lui D, Ning Y, Jirik FR, Brenner S, Venkatesh B. The regulation of retina specific expression of rhodopsin gene in vertebrates. Gene 2003; 313:189-200. [PMID: 12957390 DOI: 10.1016/s0378-1119(03)00680-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Rhodopsin genes in most vertebrate species, with the exception of teleost fishes, contain introns. Despite differences in the gene structure, similar regulatory motifs have been identified in fish, amphibian and mammalian rhodopsin promoters, suggesting that rhodopsin gene regulation may be conserved in vertebrates. However, there is no direct evidence to support this notion. To address this, the rhodopsin promoter from the pufferfish, Fugu rubripes, was isolated and tested in transgenic mice and frogs. A 6.5 kb Fugu genomic fragment containing the rhodopsin gene and 4.5 kb 5' flanking region was able to direct expression of the Fugu rhodopsin gene to the retina of transgenic mice. In transgenic tadpoles, photoreceptor rod cell-specific expression of a reporter gene was achieved using only 500 bp Fugu rhodopsin promoter fragment. Mutagenesis of this promoter fragment revealed that a conserved NRE-like motif is crucial for the retina-specific expression. Our investigation suggests that the regulation of retinal specific expression is conserved in the pufferfish, frog and mouse and that the ancestral intron-containing rhodopsin gene has been displaced by an intronless copy in teleosts.
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Tan YJ, Lim SP, Ng P, Goh PY, Lim SG, Tan YH, Hong W. CD81 engineered with endocytotic signals mediates HCV cell entry: implications for receptor usage by HCV in vivo. Virology 2003; 308:250-69. [PMID: 12706076 DOI: 10.1016/s0042-6822(02)00136-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Although CD81 has been shown to bind HCV E2 protein, its role as a receptor for HCV remains controversial. In this study, we constructed two CD81 chimeras by linking the cytoplasmic domains of recycling surface receptors, low-density lipoprotein receptor (LDLR), and transferrin receptor (TfR), respectively, to CD81 and compared their internalization properties to wild-type CD81. Binding experiments with anti-hCD81 antibody showed that cell-surface CD81 chimeric receptors were internalized much more efficiently than wild-type CD81. In addition, CD81 chimeras, but not wild-type CD81, could internalize recombinant E2 protein and E2-enveloped viral particles from the serum of HCV-infected patients into Huh7 liver cells. The latter resulted in persistent positive-strand viral RNA and accumulation of replication intermediates, negative-strand viral RNA, in the infected cells, suggesting that the internalized viruses have undergone replication. Therefore, it appeared that CD81, possibly in association with a liver-specific endocytotic protein(s), represents one of the pathways by which HCV can infect hepatocytes.
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Yip SK, Tan YH, Cheng WS. Re: Comparison of hand assisted and standard laparoscopic radical nephroureterectomy for the management of localized transitional cell carcinoma. J Urol 2003; 169:1474-5. [PMID: 12629392 DOI: 10.1097/01.ju.0000053929.53029.a6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Kam MH, Tan YH, Wong MYC. A 12-year experience in the surgical management of vesicovaginal fistulae. Singapore Med J 2003; 44:181-4. [PMID: 12952029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
INTRODUCTION Vesicovaginal fistulae are largely iatrogenic and represent therapeutic dilemmas in surgical approach and timing of repairs. AIM We have reviewed our surgical management of vesicovaginal fistulae over a 12-year period to determine whether the outcome is dependent on surgical approach and timing of repair. PATIENTS AND METHODS From January 1990 to September 2001, 23 patients were referred to our department of whom 20 have retrievable records. Fourteen of these 20 patients had gynaecological operations as the primary cause for their fistulas whilst the remaining six had varied causes ranging from forceps delivery to recurrent pelvic malignancies. RESULTS Of 20 patients, four underwent transvaginal repair, seven transvesical repair, eight supravesical repair and one required an ileal conduit diversion. There was an 85% success after first repair with only three fistula recurrences, two of whom underwent a successful second repair and one was treated conservatively and successfully with urethral catheterisation. There were no further recurrences at mean follow-up of 23 months for our cohort. Earlier repair seemed to be associated with a higher recurrence rate (33% of six patients within six weeks) compared with delayed operations (7% of remaining 14 operated after six weeks). CONCLUSION Vesicovaginal fistulae can be successfully managed surgically. Although the type of approach did not affect outcome, the timing of the repair may affect the success of the operation.
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Tan YH, Yip SKH, Chee C, Cheng CWS. Comparison of laparoscopic and open adrenalectomy--a Singapore experience. Asian J Surg 2002; 25:330-4; discussion 335-6. [PMID: 12471008 DOI: 10.1016/s1015-9584(09)60202-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
OBJECTIVE We present our experience with laparoscopic adrenalectomy for benign adrenal diseases and compare clinical outcomes with the conventional open approach. METHODS Between 1990 and 2001, two consecutive series of patients who underwent adrenalectomy for small, benign adrenal diseases were reviewed retrospectively. Patients with large tumours(> 7 cm), cancer and phaeochromocytoma were excluded. Fifty-eight patients underwent laparoscopic adrenalectomy and 48 patients had open surgery for benign adrenal diseases. Perioperative and postoperative records of both approaches were reviewed. RESULTS The two groups were comparable in terms of patient age, sex, weight and side of lesion.The common indications for surgery were Conn's syndrome and Cushing's syndrome. The sizes of tumour were comparable between the laparoscopic and open groups (mean, 2.1 cm vs 2.4 cm). Despite the longer operating time (mean, 128 minutes vs 87 minutes), the postoperative morbidity, parenteral analgesic requirement and length of postoperative hospital stay (3.2 days vs 7.2 days) were less inpatients undergoing laparoscopic adrenalectomy. Patients also enjoyed earlier return to oral intake and ambulation. There were fewer complications in the laparoscopic group. There was no conversion to open surgery. CONCLUSION Laparoscopic adrenalectomy is safe and has become the treatment of choice for small, benign adrenal lesions at our institution.
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Aparicio S, Chapman J, Stupka E, Putnam N, Chia JM, Dehal P, Christoffels A, Rash S, Hoon S, Smit A, Gelpke MDS, Roach J, Oh T, Ho IY, Wong M, Detter C, Verhoef F, Predki P, Tay A, Lucas S, Richardson P, Smith SF, Clark MS, Edwards YJK, Doggett N, Zharkikh A, Tavtigian SV, Pruss D, Barnstead M, Evans C, Baden H, Powell J, Glusman G, Rowen L, Hood L, Tan YH, Elgar G, Hawkins T, Venkatesh B, Rokhsar D, Brenner S. Whole-genome shotgun assembly and analysis of the genome of Fugu rubripes. Science 2002; 297:1301-10. [PMID: 12142439 DOI: 10.1126/science.1072104] [Citation(s) in RCA: 1229] [Impact Index Per Article: 55.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The compact genome of Fugu rubripes has been sequenced to over 95% coverage, and more than 80% of the assembly is in multigene-sized scaffolds. In this 365-megabase vertebrate genome, repetitive DNA accounts for less than one-sixth of the sequence, and gene loci occupy about one-third of the genome. As with the human genome, gene loci are not evenly distributed, but are clustered into sparse and dense regions. Some "giant" genes were observed that had average coding sequence sizes but were spread over genomic lengths significantly larger than those of their human orthologs. Although three-quarters of predicted human proteins have a strong match to Fugu, approximately a quarter of the human proteins had highly diverged from or had no pufferfish homologs, highlighting the extent of protein evolution in the 450 million years since teleosts and mammals diverged. Conserved linkages between Fugu and human genes indicate the preservation of chromosomal segments from the common vertebrate ancestor, but with considerable scrambling of gene order.
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Liu H, Xin L, Chan BPL, Teoh R, Tang BL, Tan YH. Interferon-beta administration confers a beneficial outcome in a rabbit model of thromboembolic cerebral ischemia. Neurosci Lett 2002; 327:146-8. [PMID: 12098656 DOI: 10.1016/s0304-3940(02)00371-3] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We demonstrate that treatment with the cytokine human interferon-beta (IFN-beta) resulted in a beneficial outcome in a rabbit model of thromboembolic cerebral ischemia. Rabbits administered subcutaneously with IFN-beta prior to (pre-treatment) or after (post-treatment) the introduction of an autologous blood clot into the middle cerebral artery have consistently smaller subcortical infarct volumes compared to control (untreated) counterparts. The average subcortical infarct volume of pre-treatment rabbits is 46.3+/-9.3 mm(3) (n=4), and that of post-treatment rabbit is 40.0+/-23.1 mm(3) (n=4). Both are significantly lower (P=0.003 and P=0.004, respectively) than the average subcortical infarct volume of control rabbits (121.6+/-32.9 mm(3), n=5). Although the precise mechanism responsible for the beneficial effect of IFN-beta on stroke is not yet clear, our results are in line with the known anti-inflammatory potential and anti-apoptotic function of IFN-beta.
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Abrahams BS, Mak GM, Berry ML, Palmquist DL, Saionz JR, Tay A, Tan YH, Brenner S, Simpson EM, Venkatesh B. Novel vertebrate genes and putative regulatory elements identified at kidney disease and NR2E1/fierce loci. Genomics 2002; 80:45-53. [PMID: 12079282 DOI: 10.1006/geno.2002.6795] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Fierce (frc) mice are deleted for nuclear receptor 2e1 (Nr2e1), and exhibit cerebral hypoplasia, blindness, and extreme aggression. To characterize the Nr2e1 locus, which may also contain the mouse kidney disease (kd) allele, we compared sequence from human, mouse, and the puffer fish Fugu rubripes. We identified a novel gene, c222389, containing conserved elements in noncoding regions. We also discovered a novel vertebrate gene conserved across its length in prokaryotes and invertebrates. Based on a dramatic upregulation in lactating breast, we named this gene lactation elevated-1 (LACE1). Two separate 100-bp elements within the first NR2E1 intron were virtually identical between the three species, despite an estimated 450 million years of divergent evolution. These elements represent strong candidates for functional NR2E1 regulatory elements in vertebrates. A high degree of conservation across NR2E1 combined with a lack of interspersed repeats suggests that an array of regulatory elements embedded within the gene is required for proper gene expression.
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Nguyen HD, Tan YH, Wong MYC, Nguyen HC. Percutaneous nephrolithotomy in the management of complex upper urinary tract calculi: the Singapore General Hospital experience. ANNALS OF THE ACADEMY OF MEDICINE, SINGAPORE 2002; 31:516-9. [PMID: 12161890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
Abstract
INTRODUCTION AND OBJECTIVES Presently, percutaneous nephrolithotomy (PCNL) is a well-established and effective method of treating upper urinary tract stones at our institution. The aim of this paper was to evaluate a single surgeon's four-year experience of PCNL in the Singapore General Hospital. MATERIALS AND METHODS Between January 1996 and December 2000, 300 PCNLs were performed on 280 renal units. The mean age was 53.7 years. PCNL was performed on 57 complete staghorn calculi (20.4%), 83 partial staghorn calculi (29.6%), 66 large pelvic calculi (23.6%), 60 impacted uretero-pelvic junction (UPJ) and upper ureteric stones (21.4%) that failed extracorporeal shock wave lithotripsy (ESWL) and 14 symptomatic lower pole calculi (5%). RESULTS The stone-free rate on discharge was 88.2% (n = 247). At 3 months and 1-year post PCNL, the stone-free rate was 91.1% (n = 255) and 95.7% (n = 268), respectively. The average postoperative stay was 4.5 days. Complications included 1 urosepsis post-PCNL (0.4%) and 2 arterio-venous fistulae (0.7%). Only 1 patient (0.4%) required blood transfusion. Thirty-four patients (12.1%) required ESWL and 4 needed ureteroscopy (1.3%). CONCLUSION In experienced hands, the use of PCNL for upper urinary tract calculi is safe and effective.
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