MyMedR

Diabetes mellitus exacerbates advanced glycation end product accumulation in the veins of end-stage renal failure patients

Nazratun N, Mahmood AA, Kuppusamy UR, Ahmad TS, Tan SY

Vasc Med, 2006 Nov;11(4):245-50.

PMID: 17390548

The excess accumulation of advanced glycation end products (AGEs) contributes to the chronic complications of type 2 diabetes mellitus (DM) and renal failure. Biopsy specimens (n = 184) of arterial (n = 92) and venous (n = 92) tissues were obtained (radial artery and cephalic vein) from end-stage renal disease (ESRD) patients with or without DM and normal healthy subjects (n = 12) requiring surgery (trauma patients). Immunohistochemical assessment of the blood vessels revealed the presence of pentosidine (AGE marker) in both veins and arteries in 72% of the ESRD patients. The percentage of arteries and veins that showed positive pentosidine staining in ESRD patients with type 2 DM alone was 100% and 92% respectively, in the non-diabetic ESRD patients it was < 70% (for arteries and veins), and in the ESRD patients with hypertension as an additional co-morbidity to type 2 DM it was 70% and 82%, respectively. The veins of ESRD patients with DM showed a strong (+++) positive staining and very strong (++++) positive staining was observed in the patients with DM and hypertension. Only mild (+) or moderate (++) pentosidine staining intensity was observed in the arteries of ESRD patients without or with comorbidities, respectively. The accumulation of AGE in the vein rather than the artery may be a better reflection of the extent of complications of ESRD.

Fulltext Recombinant proteins from new constructs of SAG1 and GRA7 sequences and their usefulness to detect acute toxoplasmosis

Kotresha D, Poonam D, Muhammad Hafiznur Y, Saadatnia G, Nurulhasanah O, Sabariah O, et al.

Trop Biomed, 2012 Mar;29(1):129-37.

PMID: 22543613 MyJurnal

In this study we have cloned unreported gene fragments of Toxoplasma gondii GRA7 and SAG1 and expressed the corresponding recombinant proteins, followed by evaluation of their usefulness for the serological diagnosis of toxoplasmosis. Both recombinant proteins were expressed efficiently in insoluble form, purified by single step Ni-NTA affinity chromatography and their antigenicity to detect toxoplasma specific IgG antibodies were determined by immunoblotting. A total of 60 serum samples from three groups of individuals based on their anti-toxoplasma antibody profiles were tested, namely (I) IgM+, IgG+ (n=20), (II) IgM-, IgG+ (n=20) and (III) IgM-, IgG- (n=20). Both recombinant proteins exhibited high sensitivity (100%) with sera from Group I. rGRA7 and rSAG1 reacted 40% and 80% respectively with Group II sera. The specificity of the recombinant proteins based on reactivities with Group III sera were 100% and 80% with rGRA7 and rSAG1 respectively. Thus rGRA7 was found to be better at discriminating probable acute from chronic phases of toxoplasmosis, and it also showed higher specificity.

Fulltext New mosquito species records (Diptera: Culicidae) from Singapore

Jeffery J, Lee RM, Tan SY, Liew C, Ng LC, Lam-Phua SG

Trop Biomed, 2010 Apr;27(1):138-42.

PMID: 20562825

Nine species of mosquitoes in eight genera are recorded for the first time in Singapore. An additional two species were overlooked in a 1986 checklist for mosquitoes in Singapore, and one was described after 1986. Location and habitat data are provided for the nine new records. With the inclusion of these new records the number of species reported from Singapore is 137.

Dengue maculopathy: a case report

Tan SY, Kumar G, Surrun SK, Ong YY

Travel Med Infect Dis, 2007 Jan;5(1):62-3.

PMID: 17161325

Dengue fever is endemic in many countries of South East Asia. In spite of the occasional epidemics, dengue maculopathy remains a rare entity.

Grossly delayed graft function in a living related kidney transplant recipient: a case report

Thye YL, Lim SK, Wong CM, Keng TC, Chong YB, Tan SY

Transplant Proc, 2008 Sep;40(7):2435-6.

PMID: 18790259 DOI: 10.1016/j.transproceed.2008.07.051

Delayed graft function is a potentially challenging problem especially in cadaveric kidney transplant recipients. It adversely impacts long-term graft survival. It is rarely seen in living kidney transplants. Recovery of graft function usually occurs within a month. The chances of recovery of graft function diminish with further prolongation of delayed function. In fact, recovery of graft function after 3 months has rarely been described, we report herein recovery of graft function after 132 days of nonfunction in a living related kidney transplant.

Evaluation of live renal donors with three-dimensional contrast-enhanced magnetic resonance angiography in comparison to catheter angiography

Tan SP, Bux SI, Kumar G, Razack AH, Chua CB, Lee SH, et al.

Transplant Proc, 2004 Sep;36(7):1914-6.

PMID: 15518697

Catheter angiography is traditionally used to determine renal arterial anatomy in live renal donors. Three-dimensional (3D) contrast-enhanced magnetic resonance imaging (MRA) has been suggested as a noninvasive replacement. We assessed the possibility of using MRA in live renal donors in Malaysia.

Posttransplant lymphoproliferative disease masquerading as postbiopsy hematoma

Gan WH, Thye YL, Chang SH, Chua CB, Looi LM, Tan SY

Transplant Proc, 2004 Sep;36(7):2148-9.

PMID: 15518779

Disseminated nocardiosis with bilateral intraocular involvement in a renal allograft patient

Tan SY, Tan LH, Teo SM, Thiruventhiran T, Kamarulzaman A, Hoh HB

Transplant Proc, 2000 Nov;32(7):1965-6.

PMID: 11120022

Cyclosporine-associated encephalopathy: a case report and literature review

Chang SH, Lim CS, Low TS, Chong HT, Tan SY

Transplant Proc, 2001 12 26;33(7-8):3700-1.

PMID: 11750577

Cadaveric organ donation at University Hospital Kuala Lumpur

Chen TP, Teo SM, Tan JC, Koh SN, Ambalavanar N, Tan SY

Transplant Proc, 2000 Nov;32(7):1809-10.

PMID: 11119946

Cadaveric renal transplantation at University Hospital Kuala Lumpur: a preliminary report

Tan SY, Chen TP, Lee SH, Tan PS, Chua CT, Teo SM, et al.

Transplant Proc, 2000 Nov;32(7):1811-2.

PMID: 11119947

Conversion from Sandimmune to Neoral in patients with stable renal allograft function: UHKL experience

Goh BL, Jalil R, Koh SN, Chua CT, Tan SY

Transplant Proc, 1998 Nov;30(7):3535-6.

PMID: 9838548

FK506 "rescue" therapy complicated by renal tubular acidosis in renal allograft recipients

Goh BL, Tan SY

Transplant Proc, 1998 Nov;30(7):3594-5.

PMID: 9838575

FK506 rescue therapy for acute renal allograft rejection

Goh BL, Morad Z, Cheah PL, Chua CT, Tan SY

Transplant Proc, 1998 Nov;30(7):3592-3.

PMID: 9838574

Fulltext ABO-Incompatible Living-Donor Kidney Transplantation in a Developing Country: A Multicenter Experience in Malaysia

Gan CC, Jalalonmuhali M, Nordin NZ, Abdul Wahab MZ, Yahya R, Ng KP, et al.

Transplant Proc, 2021 Apr;53(3):856-864.

PMID: 33487455 DOI: 10.1016/j.transproceed.2020.10.038

Malaysia has a low deceased-donor donation rate and has not embarked on a paired kidney exchange program; therefore, ABO-incompatible and HLA-incompatible transplantation remain the main contributor to the sustainability of the national kidney transplantation (KT) program. There were 26 cases of ABO-incompatible KTs performed from 2011 to 2018 in 3 major transplant centers, namely, Hospital Kuala Lumpur, University Malaya Medical Centre, and Prince Court Medical Centre. We collected perioperative and follow-up data through June 2019. The desensitization protocol varies and is center specific: the localized Japanese protocol and Swedish protocol with a target anti-A/B isoagglutinin titer of 16 or 32 on the day of transplant. The induction and tacrolimus-based maintenance protocol was nearly identical. The median follow-up time was 62.3 months (interquartile range, 37.0-79.7). Fifteen subjects had the highest predesensitization anti-A/B titer of ≥32 (57.7%). The acute cellular rejection and antibody-mediated rejection incidence were 12.5% (3 cases) and 8.3% (2 cases), respectively. Patient, graft, and death-censored graft survival rates were 96.2%, 92.3%, and 96.0%, respectively, 1 year post-living-donor KT (LDKT) and 96.2%, 87.2%, and 90.7%, respectively, 5 years post-LDKT. Our experience shows that ABO-incompatible LDKT using a suitable desensitization technique could be a safe and feasible choice for LDKT even with varied desensitization regimens for recipients with relatively high baseline isoagglutinin titers.

Fulltext Twin-Schnorr: a security upgrade for the Schnorr identity-based identification scheme

Chin JJ, Tan SY, Heng SH, Phan RC

ScientificWorldJournal, 2015;2015:237514.

PMID: 25692179 DOI: 10.1155/2015/237514

Most identity-based identification (IBI) schemes proposed in recent literature are built using pairing operations. This decreases efficiency due to the high operation costs of pairings. Furthermore, most of these IBI schemes are proven to be secure against impersonation under active and concurrent attacks using interactive assumptions such as the one-more RSA inversion assumption or the one-more discrete logarithm assumption, translating to weaker security guarantees due to the interactive nature of these assumptions. The Schnorr-IBI scheme was first proposed through the Kurosawa-Heng transformation from the Schnorr signature. It remains one of the fastest yet most secure IBI schemes under impersonation against passive attacks due to its pairing-free design. However, when required to be secure against impersonators under active and concurrent attacks, it deteriorates greatly in terms of efficiency due to the protocol having to be repeated multiple times. In this paper, we upgrade the Schnorr-IBI scheme to be secure against impersonation under active and concurrent attacks using only the classical discrete logarithm assumption. This translates to a higher degree of security guarantee with only some minor increments in operational costs. Furthermore, because the scheme operates without pairings, it still retains its efficiency and superiority when compared to other pairing-based IBI schemes.

Fulltext Efficient and provable secure pairing-free security-mediated identity-based identification schemes

Chin JJ, Tan SY, Heng SH, Phan RC

ScientificWorldJournal, 2014;2014:170906.

PMID: 25207333 DOI: 10.1155/2014/170906

Security-mediated cryptography was first introduced by Boneh et al. in 2001. The main motivation behind security-mediated cryptography was the capability to allow instant revocation of a user's secret key by necessitating the cooperation of a security mediator in any given transaction. Subsequently in 2003, Boneh et al. showed how to convert a RSA-based security-mediated encryption scheme from a traditional public key setting to an identity-based one, where certificates would no longer be required. Following these two pioneering papers, other cryptographic primitives that utilize a security-mediated approach began to surface. However, the security-mediated identity-based identification scheme (SM-IBI) was not introduced until Chin et al. in 2013 with a scheme built on bilinear pairings. In this paper, we improve on the efficiency results for SM-IBI schemes by proposing two schemes that are pairing-free and are based on well-studied complexity assumptions: the RSA and discrete logarithm assumptions.

A follow-up study on the effects of a milk supplement on bone mineral density of postmenopausal Chinese women in Malaysia

Ting GP, Tan SY, Chan SP, Karuthan C, Zaitun Y, Suriah AR, et al.

J Nutr Health Aging, 2007 Jan-Feb;11(1):69-73.

PMID: 17315084

A previous study on a randomized controlled trial in 173 postmenopausal Chinese women in Kuala Lumpur showed that milk supplementation was effective to reduce bone loss at the total body, lumbar spine, femoral neck and total hip compared to the control group on a usual diet (Chee et al. 2003).

Fulltext Peritoneal implantation of ureter in a cadaveric kidney transplant recipient

Tan SY, Lim CS, Teo SM, Lee SH, Razack A, Loh CS

Med J Malaysia, 2003 Dec;58(5):769-70.

PMID: 15190667

We report here a case of a kidney transplant recipient in whom the ureter was initially implanted into the peritoneum. Excessive ultrafiltration volume and reversal of serum vs dialysate creatinine ratio when the patient was recommenced on continuous ambulatory peritoneal dialysis first suggested the diagnosis which was subsequently confirmed by a plain abdominal x-ray demonstrating placement of ureteric stent in the peritoneum. This rare complication was successfully corrected with surgical re-implantation of ureter into the bladder and 5 years later, the patient remains well with good graft function.

Fulltext Genetic risk of extranodal natural killer T-cell lymphoma: a genome-wide association study

Li Z, Xia Y, Feng LN, Chen JR, Li HM, Cui J, et al.

Lancet Oncol, 2016 Sep;17(9):1240-7.

PMID: 27470079 DOI: 10.1016/S1470-2045(16)30148-6

BACKGROUND: Extranodal natural killer T-cell lymphoma (NKTCL), nasal type, is a rare and aggressive malignancy that occurs predominantly in Asian and Latin American populations. Although Epstein-Barr virus infection is a known risk factor, other risk factors and the pathogenesis of NKTCL are not well understood. We aimed to identify common genetic variants affecting individual risk of NKTCL.

METHODS: We did a genome-wide association study of 189 patients with extranodal NKTCL, nasal type (WHO classification criteria; cases) and 957 controls from Guangdong province, southern China. We validated our findings in four independent case-control series, including 75 cases from Guangdong province and 296 controls from Hong Kong, 65 cases and 983 controls from Guangdong province, 125 cases and 1110 controls from Beijing (northern China), and 60 cases and 2476 controls from Singapore. We used imputation and conditional logistic regression analyses to fine-map the associations. We also did a meta-analysis of the replication series and of the entire dataset.

FINDINGS: Associations exceeding the genome-wide significance threshold (p<5 × 10(-8)) were seen at 51 single-nucleotide polymorphisms (SNPs) mapping to the class II MHC region on chromosome 6, with rs9277378 (located in HLA-DPB1) having the strongest association with NKTCL susceptibility (p=4·21 × 10(-19), odds ratio [OR] 1·84 [95% CI 1·61-2·11] in meta-analysis of entire dataset). Imputation-based fine-mapping across the class II MHC region suggests that four aminoacid residues (Gly84-Gly85-Pro86-Met87) in near-complete linkage disequilibrium at the edge of the peptide-binding groove of HLA-DPB1 could account for most of the association between the rs9277378*A risk allele and NKTCL susceptibility (OR 2·38, p value for haplotype 2·32 × 10(-14)). This association is distinct from MHC associations with Epstein-Barr virus infection.

INTERPRETATION: To our knowledge, this is the first time that a genetic variant conferring an NKTCL risk is noted at genome-wide significance. This finding underlines the importance of HLA-DP antigen presentation in the pathogenesis of NKTCL.

FUNDING: Top-Notch Young Talents Program of China, Special Support Program of Guangdong, Specialized Research Fund for the Doctoral Program of Higher Education (20110171120099), Program for New Century Excellent Talents in University (NCET-11-0529), National Medical Research Council of Singapore (TCR12DEC005), Tanoto Foundation Professorship in Medical Oncology, New Century Foundation Limited, Ling Foundation, Singapore National Cancer Centre Research Fund, and the US National Institutes of Health (1R01AR062886, 5U01GM092691-04, and 1R01AR063759-01A1).

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