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Ooi SH, Ng KP, Sthaneshwar P, Lim SK, Khor PY, Lim JY, Siow WS, Lim KW, Azlan M. A study of hospitalized COVID-19 patients with AKI in a setting of multiracial developing country. BMC Nephrol 2024; 25:122. [PMID: 38580977 PMCID: PMC10998399 DOI: 10.1186/s12882-024-03498-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Accepted: 02/12/2024] [Indexed: 04/07/2024] Open
Abstract
BACKGROUND The commonest indication for hospitalization in COVID-19 patients is hypoxemia or severe respiratory symptoms. However, COVID-19 disease may result in extrapulmonary complications including kidney-related pathology. The reported incidence of renal involvement related to COVID infection varies based on geographical location. OBJECTIVE This study aimed to assess the incidence rate of AKI in hospitalized COVID-19 patients and identify risk factors and prognostic predictors. METHOD In this retrospective study, we recruited hospitalized COVID-19 patients from January 2021 until June 2021 at the University Malaya Medical Center. The inclusion criteria were hospitalized for ≥ 48 h with confirmed COVID-19 infection and at least 18 years old. Patient demographic and clinical data were collected from electronic medical records. The staging of AKI was based on criteria as per KDIGO guidelines. RESULTS One thousand five hundred twenty-nine COVID patients fulfilled the inclusion criteria with a male-to-female ratio of 759 (49.6%) to 770 (50.3%). The median age was 55 (IQR: 36-66). 500 patients (32.7%) had diabetes, 621 (40.6%) had hypertension, and 5.6% (n = 85) had pre-existing chronic kidney disease (CKD). The incidence rate of AKI was 21.1% (n = 323). The percentage of COVID patients in different AKI stages of 1,2 and 3 were 16.3%, 2.1%, and 2.7%, respectively. Fifteen hospitalized patients (0.98%) required renal replacement therapy. 58.8% (n = 190) of AKI group had complete recovery of kidney function. Demographic factors included age (p < 0.001), diabetes (p < 0.001), hypertension (p < 0.012), CKD (p < 0.001), and vaccination status (p = 0.042) were associated with an increased risk of developing AKI. We found that the AKI cohort had statistically significant lower platelet counts and higher ferritin levels than the non-AKI cohort. AKI is a risk predictor of prolonged hospitalization (p < 0.001) and higher mortality rates (P < 0.001). CONCLUSION AKI is a common clinical complication among hospitalized COVID-19 patients. The etiology of AKI is multifactorial and may have an adverse impact on patient morbidity and mortality.
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Affiliation(s)
- S H Ooi
- Internal Medicine Department, University Malaya Medical Center, Kuala Lumpur, Malaysia
| | - K P Ng
- Internal Medicine Department, University Malaya Medical Center, Kuala Lumpur, Malaysia.
| | | | - S K Lim
- Internal Medicine Department, University Malaya Medical Center, Kuala Lumpur, Malaysia
| | - P Y Khor
- Internal Medicine Department, University Malaya Medical Center, Kuala Lumpur, Malaysia
| | - J Y Lim
- Internal Medicine Department, University Malaya Medical Center, Kuala Lumpur, Malaysia
| | - W S Siow
- Internal Medicine Department, University Malaya Medical Center, Kuala Lumpur, Malaysia
| | - K W Lim
- Internal Medicine Department, University Malaya Medical Center, Kuala Lumpur, Malaysia
| | - Muhummad Azlan
- Internal Medicine Department, University Malaya Medical Center, Kuala Lumpur, Malaysia
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Biswas S, Kang K, Ng KP, Radivoyevitch T, Schalper K, Zhang H, Lindner DJ, Thomas A, MacPherson D, Gastman B, Schrump DS, Wong KK, Velcheti V, Saunthararajah Y. Neuroendocrine lineage commitment of small cell lung cancers can be leveraged into p53-independent non-cytotoxic therapy. Cell Rep 2023; 42:113016. [PMID: 37597186 PMCID: PMC10528072 DOI: 10.1016/j.celrep.2023.113016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 07/10/2023] [Accepted: 08/04/2023] [Indexed: 08/21/2023] Open
Abstract
Small cell lung cancers (SCLCs) rapidly resist cytotoxic chemotherapy and immune checkpoint inhibitor (ICI) treatments. New, non-cross-resistant therapies are thus needed. SCLC cells are committed into neuroendocrine lineage then maturation arrested. Implicating DNA methyltransferase 1 (DNMT1) in the maturation arrests, we find (1) the repression mark methylated CpG, written by DNMT1, is retained at suppressed neuroendocrine-lineage genes, even as other repression marks are erased; (2) DNMT1 is recurrently amplified, whereas Ten-Eleven-Translocation 2 (TET2), which functionally opposes DNMT1, is deleted; (3) DNMT1 is recruited into neuroendocrine-lineage master transcription factor (ASCL1, NEUROD1) hubs in SCLC cells; and (4) DNMT1 knockdown activated ASCL1-target genes and released SCLC cell-cycling exits by terminal lineage maturation, which are cycling exits that do not require the p53/apoptosis pathway used by cytotoxic chemotherapy. Inhibiting DNMT1/corepressors with clinical compounds accordingly extended survival of mice with chemorefractory and ICI-refractory, p53-null, disseminated SCLC. Lineage commitment of SCLC cells can hence be leveraged into non-cytotoxic therapy able to treat chemo/ICI-refractory SCLC.
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Affiliation(s)
- Sudipta Biswas
- Department of Translational Hematology and Oncology Research, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Kai Kang
- Department of Translational Hematology and Oncology Research, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Kwok Peng Ng
- Department of Translational Hematology and Oncology Research, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Tomas Radivoyevitch
- Department of Quantitative Health Sciences, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Kurt Schalper
- Department of Pathology, School of Medicine, Yale University, New Haven, CT 06510, USA
| | - Hua Zhang
- Thoracic Oncology Program, Langone-Laura and Isaac Perlmutter Cancer Center, New York University, New York, NY 10016, USA
| | - Daniel J Lindner
- Department of Translational Hematology and Oncology Research, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Anish Thomas
- Experimental Therapeutics Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | | | - Brian Gastman
- Department of Plastic Surgery, Surgery Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - David S Schrump
- Thoracic Epigenetics Section, Thoracic Surgery Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Kwok-Kin Wong
- Thoracic Oncology Program, Langone-Laura and Isaac Perlmutter Cancer Center, New York University, New York, NY 10016, USA
| | - Vamsidhar Velcheti
- Thoracic Oncology Program, Langone-Laura and Isaac Perlmutter Cancer Center, New York University, New York, NY 10016, USA.
| | - Yogen Saunthararajah
- Department of Translational Hematology and Oncology Research, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH 44195, USA; Department of Hematology and Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH 44195, USA.
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Gauthier S, Ismail Z, Goodarzi Z, Ng KP, Rosa-Neto P. Viewpoint: Clinicians' Perspectives on How Disease Modifying Drugs for Alzheimer's Disease Impact Specialty Care. J Prev Alzheimers Dis 2023; 10:339-341. [PMID: 37357267 DOI: 10.14283/jpad.2023.72] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/27/2023]
Abstract
Clinicians specialized in the diagnosis and management of persons living with early-stage Alzheimer's disease need to enable access, for those meeting criteria, to the new class of disease modifying drugs (DMDs). These drugs act on amyloid β42 and delay progression of symptoms. Thus, there will be interest from patients and families. Over the short term, the use of antibodies administered intravenously with serial MRIs to detect amyloid-related imaging abnormalities (ARIA) may require participation in structured phase 4 studies or in registries with third party funding for support staff and MRI scans. In the mid term, the availability of oral anti-amyloid therapy, likely with lower risk of ARIA, may transform clinical practice to a model of screening suitable patients using plasma biomarkers, with a subsequent rapid referral to a specialized memory clinic. Eventually, the biological profile of patients for amyloid, tau, and inflammation will determine which type of DMD to use. We are optimistic that clinicians will gain confidence with the use DMDs and answer the increasing needs of our aging population.
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Affiliation(s)
- S Gauthier
- Serge Gauthier, Translational Neuroimaging Laboratory, The McGill University Research Centre for Studies in Aging, 6875 La Salle Blvd - FBC room 3149, Montreal, QC, Canada H4H 1R3,
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Ng KP, Shen JY, Chiew HJ, Ng ASL, Kandiah N, Rosa-Neto P, Gauthier S. White Matter Hyperintensity as a Vascular Contribution to the AT(N) Framework. J Prev Alzheimers Dis 2023; 10:387-400. [PMID: 37357280 DOI: 10.14283/jpad.2023.53] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/27/2023]
Abstract
The AT(N) framework enables the classification of an individual within the biological Alzheimer's disease (AD) continuum by pairing the cognitive stage with the biomarker status of amyloid-beta (Aβ, A), tau (T) and neurodegeneration (N). AD is a multifactorial disease that may involve different pathogenic mechanisms such as cerebrovascular disease (CVD). Therefore, biomarkers of these mechanisms can be added to the AT(N) framework to enhance the biomarker characterization of individuals within the AD continuum. In AD, white matter hyperintensities (WMH) which are postulated to develop as a result of chronic ischemia from small vessel CVD are shown to play a role in the aetiology. However, the interplay of WMH with Aβ and tau pathophysiology in AD remains unclear. In this review, we summarized the studies that evaluated the associations between WMH and AD pathophysiology (Aβ and tau). We found that the evidence supporting the association of WMH with Aβ was mixed, and this may be explained by the relative contributions of WMH due to its differential load and anatomical distribution. More studies are also needed to determine the association of WMH with tau pathology. Future longitudinal studies with harmonized methodologies to quantify WMH and account for the anatomical differences of WMH are required to validate the relationship between WMH and AT(N) biomarkers. This will allow a clearer understanding of the utility of WMH as a vascular biomarker in the AT(N) framework. Novel CVD biomarkers will also have the potential to further elucidate the contributions of CVD to the AD pathophysiology.
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Affiliation(s)
- K P Ng
- A/Prof. Ng Kok Pin, Senior Consultant, National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore 308433, Tel: +65 63577153,
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Gan CC, Jalalonmuhali M, Nordin NZ, Abdul Wahab MZ, Yahya R, Ng KP, Tan SY, Lim SK. ABO-Incompatible Living-Donor Kidney Transplantation in a Developing Country: A Multicenter Experience in Malaysia. Transplant Proc 2021; 53:856-864. [PMID: 33487455 DOI: 10.1016/j.transproceed.2020.10.038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Accepted: 10/30/2020] [Indexed: 11/28/2022]
Abstract
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.
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Affiliation(s)
- C C Gan
- Renal Division, Department of Medicine, Faculty of Medicine, University of Malaya, Jalan Universiti, Kuala Lumpur, Wilayah Persekutuan, Kuala Lumpur, Malaysia
| | - M Jalalonmuhali
- Renal Division, Department of Medicine, Faculty of Medicine, University of Malaya, Jalan Universiti, Kuala Lumpur, Wilayah Persekutuan, Kuala Lumpur, Malaysia
| | - N Z Nordin
- Department of Nephrology, Hospital Kuala Lumpur, Ministry of Health Malaysia, Jalan Pahang, Kuala Lumpur, Malaysia
| | - M Z Abdul Wahab
- Department of Nephrology, Hospital Kuala Lumpur, Ministry of Health Malaysia, Jalan Pahang, Kuala Lumpur, Malaysia
| | - R Yahya
- Department of Nephrology, Hospital Kuala Lumpur, Ministry of Health Malaysia, Jalan Pahang, Kuala Lumpur, Malaysia
| | - K P Ng
- Renal Division, Department of Medicine, Faculty of Medicine, University of Malaya, Jalan Universiti, Kuala Lumpur, Wilayah Persekutuan, Kuala Lumpur, Malaysia
| | - S Y Tan
- Department of Nephrology, Prince Court Medical Center, Kuala Lumpur, Malaysia
| | - S K Lim
- Renal Division, Department of Medicine, Faculty of Medicine, University of Malaya, Jalan Universiti, Kuala Lumpur, Wilayah Persekutuan, Kuala Lumpur, Malaysia.
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Wang BZ, Zailan FZ, Wong BYX, Ng KP, Kandiah N. Identification of novel candidate autoantibodies in Alzheimer's disease. Eur J Neurol 2020; 27:2292-2296. [PMID: 32356904 DOI: 10.1111/ene.14290] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 04/23/2020] [Indexed: 12/19/2022]
Abstract
BACKGROUND AND PURPOSE Accumulated failures in Alzheimer's disease (AD) clinical trials have highlighted an urgent need to identify additional biomarkers involved in AD. Recently, mounting evidence reported that autoantibodies are ubiquitous in human sera. However, it is unknown whether autoantibodies are upregulated in amyloid-tau biomarker-confirmed AD. METHODS A total of 40 subjects with mild dementia (Clinical Dementia Rating = 1) were stratified into AD (n = 16) and non-AD (n = 24) groups according to their cerebrospinal fluid levels of tau and Aβ42 . Their sera were collected and analyzed using a microarray containing > 1600 potential human autoantigens. Autoantibodies that were present exclusively in the AD group were identified and selected using the penetrance-based fold change method with the following criteria: penetrance fold change(AD) ≥ 2, frequency(AD) ≥ 15% and frequency(non-AD) = 0%. RESULTS All controls and samples passed the quality control criteria and were further used for biomarker analysis. Six autoantibodies with elevated responses to the following autoantigens were found exclusively in the AD group: nucleosome assembly protein 1-like 3 (31.3%, 5/16 subjects) and microtubule-associated protein 4, pantothenic acid kinase 3, phosphoinositide-3-kinase regulatory subunit 1, protein tyrosine phosphatase type IVA member 1 and SRY (sex-determining region Y)-box 15 (all 18.8%, 3/16 subjects). CONCLUSIONS Although some identified autoantigens are linked to AD and cognitive dysfunction, the increased autoantibody levels have not been reported in AD. Autoantibodies may provide deeper insights into the pathogenesis of AD and serve as diagnostic biomarkers; their corresponding antigens can be further studied to assess their potential as therapeutic targets.
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Affiliation(s)
- B Z Wang
- Department of Neurology, National Neuroscience Institute, Singapore
| | - F Z Zailan
- Department of Neurology, National Neuroscience Institute, Singapore
| | - B Y X Wong
- Department of Neurology, National Neuroscience Institute, Singapore
| | - K P Ng
- Department of Neurology, National Neuroscience Institute, Singapore
| | - N Kandiah
- Department of Neurology, National Neuroscience Institute, Singapore.,Duke-NUS Graduate Medical School, Singapore.,NTU-Imperial Lee Kong Chian School of Medicine, Singapore, Singapore
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Li Y, Ba M, Du Y, Xia C, Tan S, Ng KP, Ma G. Aβ1-42 increases the expression of neural KATP subunits Kir6.2/SUR1 via the NF-κB, p38 MAPK and PKC signal pathways in rat primary cholinergic neurons. Hum Exp Toxicol 2019; 38:665-674. [PMID: 30868916 DOI: 10.1177/0960327119833742] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
ATP-sensitive potassium channels (KATP) may mediate a potential neuroprotective role in Alzheimer's disease (AD). Given that exposure to Aβ1-42 in cultured primary cholinergic neurons for 72 h significantly upregulates the expression of KATP subunits Kir6.2/SUR1, we aim to study the underlying signal transduction mechanisms that are involved in Aβ1-42-induced upregulation of KATP subunits Kir6.2/SUR1. In the present study, we first identified the primary cultured rat cortical and hippocampal neurons using immunocytochemistry. 0.5 μM NF-κB inhibitor SN-50, 2 μM p38MAPK inhibitor SB203580 or 2 μM PKC inhibitor Chelerythrine chloride (CTC) were then added in three separate groups, followed by 2 μM Aβ1-42 30 min later in all 3 groups. Western Blot was performed 72 h later to detect the expression of KATP subunits Kir6.2/SUR1. We found that Aβ1-42 significantly increased the level of KATP subunits Kir6.2/SUR1 expression at 72 h when compared with the control group ( p < 0.05). However, when compared with the Aβ1-42 group, the level of KATP subunits Kir6.2/SUR1 expression at 72 h significantly decreased in the SN50 + Aβ1-42 group, SB203580 + Aβ1-42 group, and the CTC + Aβ1-42 group ( p < 0.05). Our findings suggest that the NF-κB, p38 MAPK, and PKC signal pathways are partially involved in the upregulation of KATP subunits Kir6.2/SUR1 expression induced by Aβ1-42 cytotoxicity in neurons, which supports a potential theoretical basis of targeting these signal pathways in the treatment of AD.
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Affiliation(s)
- Y Li
- 1 Department of Neurology, Provincial Hospital affiliated to Shandong University, Jinan, Shandong, People's Republic of China
| | - M Ba
- 2 Department of Neurology, The Affiliated Yantai Yuhuangding Hospital of Qingdao University, Yantai City, Shandong, People's Republic of China
| | - Y Du
- 1 Department of Neurology, Provincial Hospital affiliated to Shandong University, Jinan, Shandong, People's Republic of China
| | - C Xia
- 1 Department of Neurology, Provincial Hospital affiliated to Shandong University, Jinan, Shandong, People's Republic of China
| | - S Tan
- 1 Department of Neurology, Provincial Hospital affiliated to Shandong University, Jinan, Shandong, People's Republic of China
| | - K P Ng
- 3 Department of Neurology, National Neuroscience Institute, Singapore, Singapore
| | - G Ma
- 4 Department of Neurology, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, Shandong, People's Republic of China
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Madhavan P, Chong PP, Farida J, Fauziah O, Cheah YK, Arunkumar Karunanidhi A, Ng KP. Antimicrobial susceptibilities and random amplified polymorphic DNA-PCR fingerprint characterization of Candida glabrata, Candida parapsilosis and Candida rugosa from two major hospitals in Kuala Lumpur, Malaysia. Trop Biomed 2019; 36:183-193. [PMID: 33597438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The purpose of this study is to characterize 3 non-albicans Candida spp. that were collected from two major hospitals in a densely populated area of Kuala Lumpur for their susceptibilities to azole and genetic background. Fifteen non-albicans Candida clinical isolates in two major hospitals in Kuala Lumpur area of Malaysia were collected by convenience sampling during 2007 and 2010. The genetic diversity of 15 non-albicans Candida species comprising C. glabrata (n = 5), C. parapsilosis (n = 5) and C. rugosa (n = 5) were assessed by RAPD-PCR typing. Strains were initially identified using biochemical tests and CHROMagar Candida medium. Fluconazole and voriconazole susceptibilities were determined by E-test method. Commercial kits were used for DNA extraction and amplification with RAPD primers (OPA02, OPA03 and OPA08). PCR conditions were optimized and simultaneous identification was possible by agarose gel electrophoresis of PCR products and the bands obtained were analyzed using BioNumerics Applied Maths v.6.6 software. The RAPD primers used in this study generated 100% polymorphic profile. Cluster analysis using the RAPD-PCR profile showed 12.5-25% similarity among the strains. The genetic diversity was based on the strain susceptibility towards both the azoles, site of isolation and place according to their unique banding patterns. In contrast, strains susceptible to azoles were found to be genetically similar with clonal dissimilarity. The use of OPA02, OPA03 and OPA08 primers in differentiating non-albicans Candida spp. underscores the higher resolution of RAPD-PCR as a reliable tool for strain/species level differentiation.
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Affiliation(s)
- P Madhavan
- School of Medicine, Faculty of Health and Medical Sciences, Taylor's University, No. 1, Jalan Taylor's, 47500 Subang Jaya, Selangor Darul Ehsan, Malaysia
- Department of Medical Microbiology and Parasitology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 Serdang, Selangor Darul Ehsan, Malaysia
| | - P P Chong
- School of Biosciences, Faculty of Health and Medical Sciences, Taylor's University, No. 1, Jalan Taylor's, 47500 Subang Jaya, Selangor Darul Ehsan, Malaysia
| | - J Farida
- Department of Medical Microbiology and Parasitology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 Serdang, Selangor Darul Ehsan, Malaysia
| | - O Fauziah
- Department of Human Anatomy, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 Serdang, Selangor Darul Ehsan, Malaysia
| | - Y K Cheah
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 Serdang, Selangor Darul Ehsan, Malaysia
| | - A Arunkumar Karunanidhi
- Department of Medical Microbiology and Parasitology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 Serdang, Selangor Darul Ehsan, Malaysia
| | - K P Ng
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur, Malaysia
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Ba M, Ng KP, Gao X, Kong M, Guan L, Yu L. The combination of apolipoprotein E4, age and Alzheimer's Disease Assessment Scale - Cognitive Subscale improves the prediction of amyloid positron emission tomography status in clinically diagnosed mild cognitive impairment. Eur J Neurol 2019; 26:733-e53. [PMID: 30561868 DOI: 10.1111/ene.13881] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2018] [Accepted: 12/06/2018] [Indexed: 01/28/2023]
Abstract
BACKGROUND AND PURPOSE Randomized clinical trials involving anti-amyloid interventions focus on the early stages of Alzheimer's disease (AD) with proven amyloid pathology, using amyloid positron emission tomography (amyloid-PET) imaging or cerebrospinal fluid analysis. However, these investigations are either expensive or invasive and are not readily available in resource-limited centres. Hence, the identification of cost-effective clinical alternatives to amyloid-PET is highly desirable. This study aimed to investigate the accuracy of combined clinical markers in predicting amyloid-PET status in mild cognitive impairment (MCI) individuals. METHODS In all, 406 MCI participants from the Alzheimer's Disease Neuroimaging Initiative database were dichotomized into amyloid-PET(+) and amyloid-PET(-) using a cut-off of >1.11. The accuracies of single clinical markers [apolipoprotein E4 (ApoE4) genotype, demographics, cognitive measures and cerebrospinal fluid analysis] in predicting amyloid-PET status were evaluated using receiver operating characteristic curve analysis. A logistic regression model was then used to determine the optimal model with combined clinical markers to predict amyloid-PET status. RESULTS Cerebrospinal fluid amyloid-β (Aβ) showed the best predictive accuracy of amyloid-PET status [area under the curve (AUC) = 0.927]. Whilst ApoE4 genotype (AUC = 0.737) and Alzheimer's Disease Assessment Scale - Cognitive Subscale (ADAS-Cog) 13 (AUC = 0.724) independently discriminated amyloid-PET(+) and amyloid-PET(-) MCI individuals, the combination of clinical markers (ApoE4 carrier, age >60 years and ADAS-Cog 13 > 13.5) improved the predictive accuracy of amyloid-PET status (AUC = 0.827, P < 0.001). CONCLUSIONS Cerebrospinal fluid Aβ, which is an invasive procedure, is most accurate in predicting amyloid-PET status in MCI individuals. The combination of ApoE4, age and ADAS-Cog 13 also accurately predicts amyloid-PET status. As this combination of clinical markers is cheap, non-invasive and readily available, it offers an attractive surrogate assessment for amyloid status amongst MCI individuals in resource-limited settings.
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Affiliation(s)
- M Ba
- Department of Neurology, Affiliated Yantai Yuhuangding Hospital of Qingdao University, Yantai, China
| | - K P Ng
- Department of Neurology, National Neuroscience Institute, Singapore, Singapore
| | - X Gao
- Department of Neurology, Affiliated Yantai Yuhuangding Hospital of Qingdao University, Yantai, China
| | - M Kong
- Department of Neurology, Yantaishan Hospital, Yantai City, China
| | - L Guan
- Department of Neurology, Affiliated Yantai Yuhuangding Hospital of Qingdao University, Yantai, China
| | - L Yu
- Department of Neurology, Yantaishan Hospital, Yantai City, China
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Lotfalikhani A, Khosravi Y, Sabet NS, Na SL, Ng KP, Tay ST. Genetic diversity, antifungal susceptibility and enzymatic characterisation of Malaysian clinical isolates of Candida glabrata. Trop Biomed 2018; 35:1123-1130. [PMID: 33601859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Candida glabrata has been reported as the second or third most common yeast species isolated from patients with vaginitis and invasive candidiasis. This study was aimed to determine the genetic diversity, antifungal susceptibility and enzymatic profiles of C. glabrata isolated from vaginal and blood samples in the Medical Microbiology Diagnostic Laboratory, University Malaya Medical Centre. A random amplified polymorphic DNA (RAPD) analysis method, using M13 and (GTG)5 primers, was used for strain differentiation of C. glabrata isolates. Antifungal susceptibility testing of C. glabrata isolates was determined using E-test against amphotericin B, caspofungin, fluconazole and voriconazole and microbroth dilution method against clotrimazole. The enzymic profiles of C. glabrata were determined using APIZYM semi-quantitation kit and egg-yolk agar method. A total of 14 RAPD patterns were identified amongst C. glabrata isolates investigated this study. Susceptibility to amphotericin B, caspofungin, fluconazole and voriconazole was noted. Approximately one third of the isolates demonstrated resistance to clotrimazole (MIC>=1 µg/ml). A single isolate of C. glabrata was resistant to caspofungin (MIC:1.5 µg/ml). Enzymatic activities of acid and alkaline phosphatase, aminopeptidases, esterase and lipase and phospholipase were detected in the C. glabrata isolates. The genetic diversity and antifungal susceptibility profiles of C. glabrata isolates were presented in this study. Continued surveillance and monitoring of the incidence and antifungal resistance in C. glabrata isolates is necessary.
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Affiliation(s)
- A Lotfalikhani
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Y Khosravi
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - N S Sabet
- Faculty of Medicine, SEGi University, 47810, Petaling Jaya, Malaysia
| | - S L Na
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - K P Ng
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - S T Tay
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
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11
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Molokie R, Lavelle D, Gowhari M, Pacini M, Krauz L, Hassan J, Ibanez V, Ruiz MA, Ng KP, Woost P, Radivoyevitch T, Pacelli D, Fada S, Rump M, Hsieh M, Tisdale JF, Jacobberger J, Phelps M, Engel JD, Saraf S, Hsu LL, Gordeuk V, DeSimone J, Saunthararajah Y. Oral tetrahydrouridine and decitabine for non-cytotoxic epigenetic gene regulation in sickle cell disease: A randomized phase 1 study. PLoS Med 2017; 14:e1002382. [PMID: 28880867 PMCID: PMC5589090 DOI: 10.1371/journal.pmed.1002382] [Citation(s) in RCA: 93] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 08/03/2017] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Sickle cell disease (SCD), a congenital hemolytic anemia that exacts terrible global morbidity and mortality, is driven by polymerization of mutated sickle hemoglobin (HbS) in red blood cells (RBCs). Fetal hemoglobin (HbF) interferes with this polymerization, but HbF is epigenetically silenced from infancy onward by DNA methyltransferase 1 (DNMT1). METHODS AND FINDINGS To pharmacologically re-induce HbF by DNMT1 inhibition, this first-in-human clinical trial (NCT01685515) combined 2 small molecules-decitabine to deplete DNMT1 and tetrahydrouridine (THU) to inhibit cytidine deaminase (CDA), the enzyme that otherwise rapidly deaminates/inactivates decitabine, severely limiting its half-life, tissue distribution, and oral bioavailability. Oral decitabine doses, administered after oral THU 10 mg/kg, were escalated from a very low starting level (0.01, 0.02, 0.04, 0.08, or 0.16 mg/kg) to identify minimal doses active in depleting DNMT1 without cytotoxicity. Patients were SCD adults at risk of early death despite standard-of-care, randomized 3:2 to THU-decitabine versus placebo in 5 cohorts of 5 patients treated 2X/week for 8 weeks, with 4 weeks of follow-up. The primary endpoint was ≥ grade 3 non-hematologic toxicity. This endpoint was not triggered, and adverse events (AEs) were not significantly different in THU-decitabine-versus placebo-treated patients. At the decitabine 0.16 mg/kg dose, plasma concentrations peaked at approximately 50 nM (Cmax) and remained elevated for several hours. This dose decreased DNMT1 protein in peripheral blood mononuclear cells by >75% and repetitive element CpG methylation by approximately 10%, and increased HbF by 4%-9% (P < 0.001), doubling fetal hemoglobin-enriched red blood cells (F-cells) up to approximately 80% of total RBCs. Total hemoglobin increased by 1.2-1.9 g/dL (P = 0.01) as reticulocytes simultaneously decreased; that is, better quality and efficiency of HbF-enriched erythropoiesis elevated hemoglobin using fewer reticulocytes. Also indicating better RBC quality, biomarkers of hemolysis, thrombophilia, and inflammation (LDH, bilirubin, D-dimer, C-reactive protein [CRP]) improved. As expected with non-cytotoxic DNMT1-depletion, platelets increased and neutrophils concurrently decreased, but not to an extent requiring treatment holds. As an early phase study, limitations include small patient numbers at each dose level and narrow capacity to evaluate clinical benefits. CONCLUSION Administration of oral THU-decitabine to patients with SCD was safe in this study and, by targeting DNMT1, upregulated HbF in RBCs. Further studies should investigate clinical benefits and potential harms not identified to date. TRIAL REGISTRATION ClinicalTrials.gov, NCT01685515.
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Affiliation(s)
- Robert Molokie
- Department of Medicine, University of Illinois Hospital and Health Sciences System, Chicago, Illinois, United States of America
- Jesse Brown VA Medical Center, Chicago, Illinois, United States of America
| | - Donald Lavelle
- Department of Medicine, University of Illinois Hospital and Health Sciences System, Chicago, Illinois, United States of America
- Jesse Brown VA Medical Center, Chicago, Illinois, United States of America
| | - Michel Gowhari
- Department of Medicine, University of Illinois Hospital and Health Sciences System, Chicago, Illinois, United States of America
| | - Michael Pacini
- Department of Medicine, University of Illinois Hospital and Health Sciences System, Chicago, Illinois, United States of America
| | - Lani Krauz
- Department of Medicine, University of Illinois Hospital and Health Sciences System, Chicago, Illinois, United States of America
| | - Johara Hassan
- Department of Medicine, University of Illinois Hospital and Health Sciences System, Chicago, Illinois, United States of America
| | - Vinzon Ibanez
- Jesse Brown VA Medical Center, Chicago, Illinois, United States of America
| | - Maria A. Ruiz
- Jesse Brown VA Medical Center, Chicago, Illinois, United States of America
| | - Kwok Peng Ng
- Translational Hematology and Oncology Research, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Philip Woost
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Tomas Radivoyevitch
- Department of Quantitative Health Sciences, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Daisy Pacelli
- Department of Medicine, University of Illinois Hospital and Health Sciences System, Chicago, Illinois, United States of America
| | - Sherry Fada
- Department of Hematology and Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Matthew Rump
- Department of Hematology and Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Matthew Hsieh
- Molecular and Clinical Hematology Section, National Institutes of Health, Bethesda, Maryland, United States of America
| | - John F. Tisdale
- Molecular and Clinical Hematology Section, National Institutes of Health, Bethesda, Maryland, United States of America
| | - James Jacobberger
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Mitch Phelps
- College of Pharmacy, The Ohio State University, Columbus, Ohio, United States of America
| | - James Douglas Engel
- Cell and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Santhosh Saraf
- Department of Medicine, University of Illinois Hospital and Health Sciences System, Chicago, Illinois, United States of America
| | - Lewis L. Hsu
- Department of Medicine, University of Illinois Hospital and Health Sciences System, Chicago, Illinois, United States of America
| | - Victor Gordeuk
- Department of Medicine, University of Illinois Hospital and Health Sciences System, Chicago, Illinois, United States of America
| | - Joseph DeSimone
- Department of Medicine, University of Illinois Hospital and Health Sciences System, Chicago, Illinois, United States of America
| | - Yogen Saunthararajah
- Translational Hematology and Oncology Research, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
- Department of Hematology and Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
- * E-mail:
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12
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Enane FO, Shuen WH, Gu X, Quteba E, Przychodzen B, Makishima H, Bodo J, Ng J, Chee CL, Ba R, Seng Koh L, Lim J, Cheong R, Teo M, Hu Z, Ng KP, Maciejewski J, Radivoyevitch T, Chung A, Ooi LL, Tan YM, Cheow PC, Chow P, Chan CY, Lim KH, Yerian L, Hsi E, Toh HC, Saunthararajah Y. GATA4 loss of function in liver cancer impedes precursor to hepatocyte transition. J Clin Invest 2017; 127:3527-3542. [PMID: 28758902 DOI: 10.1172/jci93488] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 06/08/2017] [Indexed: 12/18/2022] Open
Abstract
The most frequent chromosomal structural loss in hepatocellular carcinoma (HCC) is of the short arm of chromosome 8 (8p). Genes on the remaining homologous chromosome, however, are not recurrently mutated, and the identity of key 8p tumor-suppressor genes (TSG) is unknown. In this work, analysis of minimal commonly deleted 8p segments to identify candidate TSG implicated GATA4, a master transcription factor driver of hepatocyte epithelial lineage fate. In a murine model, liver-conditional deletion of 1 Gata4 allele to model the haploinsufficiency seen in HCC produced enlarged livers with a gene expression profile of persistent precursor proliferation and failed hepatocyte epithelial differentiation. HCC mimicked this gene expression profile, even in cases that were morphologically classified as well differentiated. HCC with intact chromosome 8p also featured GATA4 loss of function via GATA4 germline mutations that abrogated GATA4 interactions with a coactivator, MED12, or by inactivating mutations directly in GATA4 coactivators, including ARID1A. GATA4 reintroduction into GATA4-haploinsufficient HCC cells or ARID1A reintroduction into ARID1A-mutant/GATA4-intact HCC cells activated hundreds of hepatocyte genes and quenched the proliferative precursor program. Thus, disruption of GATA4-mediated transactivation in HCC suppresses hepatocyte epithelial differentiation to sustain replicative precursor phenotype.
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Affiliation(s)
- Francis O Enane
- Translational Hematology and Oncology Research, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Wai Ho Shuen
- Division of Medical Oncology, National Cancer Centre Singapore, Singapore
| | - Xiaorong Gu
- Translational Hematology and Oncology Research, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Ebrahem Quteba
- Translational Hematology and Oncology Research, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Bartlomiej Przychodzen
- Translational Hematology and Oncology Research, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Hideki Makishima
- Translational Hematology and Oncology Research, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Juraj Bodo
- Translational Hematology and Oncology Research, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Joanna Ng
- Division of Medical Oncology, National Cancer Centre Singapore, Singapore
| | - Chit Lai Chee
- Division of Medical Oncology, National Cancer Centre Singapore, Singapore
| | - Rebecca Ba
- Division of Medical Oncology, National Cancer Centre Singapore, Singapore
| | - Lip Seng Koh
- Division of Medical Oncology, National Cancer Centre Singapore, Singapore
| | - Janice Lim
- Division of Medical Oncology, National Cancer Centre Singapore, Singapore
| | - Rachael Cheong
- Division of Medical Oncology, National Cancer Centre Singapore, Singapore
| | - Marissa Teo
- Division of Medical Oncology, National Cancer Centre Singapore, Singapore
| | - Zhenbo Hu
- Translational Hematology and Oncology Research, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Kwok Peng Ng
- Translational Hematology and Oncology Research, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Jaroslaw Maciejewski
- Translational Hematology and Oncology Research, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Tomas Radivoyevitch
- Department of Quantitative Health Sciences, Cleveland Clinic, Cleveland, Ohio, USA
| | - Alexander Chung
- Department of Hepato-pancreato-biliary and Transplant Surgery and
| | | | - Yu Meng Tan
- Department of Hepato-pancreato-biliary and Transplant Surgery and
| | - Peng-Chung Cheow
- Department of Hepato-pancreato-biliary and Transplant Surgery and
| | - Pierce Chow
- Department of Hepato-pancreato-biliary and Transplant Surgery and
| | - Chung Yip Chan
- Department of Hepato-pancreato-biliary and Transplant Surgery and
| | - Kiat Hon Lim
- Department of Pathology, Singapore General Hospital, Singapore
| | - Lisa Yerian
- Clinical Pathology, Pathology Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Eric Hsi
- Clinical Pathology, Pathology Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Han Chong Toh
- Division of Medical Oncology, National Cancer Centre Singapore, Singapore
| | - Yogen Saunthararajah
- Translational Hematology and Oncology Research, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio, USA
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13
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Kuan CS, Hooi PS, Lee LM, Sam IC, Ng KP. Comparison of Anyplex II RV16 assay with conventional methods for detection of respiratory viruses. Trop Biomed 2016; 33:311-319. [PMID: 33579098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Early detection of viral etiologies of acute respiratory tract infections of patients affects management and disease control in pediatric patients. In this study, the performance of Anyplex II RV16 assay (Seegene, Seoul, Korea) was evaluated by comparing with viral culture and direct immunofluorescence staining of clinical specimens for detection of respiratory viruses in patients. A total of 168 respiratory specimens were collected from 122 patients from November 2012 to May 2013 at the time of admission to the University of Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia. The Anyplex II RV16 assay, viral culture, and direct immunofluorescence staining were positive in 74.4%, 18.5% and 14.9% of the specimens, respectively. HRV was the predominant virus detected by the Anyplex II RV16 assay. In 47 cases, two or more respiratory viruses were detected by the Anyplex II RV16 assay, which were missed by conventional methods. The performance of the Anyplex II RV16 assay was better than viral culture and direct immunofluorescence staining of clinical specimens for the detection of respiratory viruses. The implementation of the Anyplex II RV16 assay in hospital laboratories will provide rapid diagnosis of major viral infections of the respiratory tract.
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Affiliation(s)
- C S Kuan
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - P S Hooi
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - L M Lee
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - I C Sam
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - K P Ng
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
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14
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Lee PY, Gam LH, Yong VC, Rosli R, Ng KP, Chong PP. Identification of immunogenic proteins of Candida parapsilosis by serological proteome analysis. J Appl Microbiol 2014; 116:999-1009. [PMID: 24299471 DOI: 10.1111/jam.12408] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Revised: 11/24/2013] [Accepted: 11/27/2013] [Indexed: 02/03/2023]
Abstract
AIMS Systemic candidiasis is the leading fungal bloodstream infection, and its incidence has been on the rise. Recently, Candida parapsilosis has emerged as an increasingly prevalent fungal pathogen, but little is known about its antigenic profile. Hence, the current work was performed to discover immunogenic proteins of C. parapsilosis using serological proteome analysis. METHODS AND RESULTS Cell wall proteins extracted from C. parapsilosis were resolved by two-dimensional electrophoresis followed by immunoblotting using antisera from experimentally infected mice. Mass spectrometry analysis of the 32 immunoreactive protein spots resulted in the identification of 12 distinct proteins. Among them, 11 proteins were known antigens of Candida albicans, whereas Idh2p was identified for the first time as an immunogenic protein of Candida species. Recombinant Idh2p was expressed in Escherichia coli, and its antigenicity was verified by immunoblot analysis. CONCLUSIONS An immunoproteomic approach was successfully applied to identify immunogenic proteins of C. parapsilosis, with Idh2p as a novel candidate antigen. The identified antigens may serve as potential biomarkers for development of diagnostic assay and/or vaccine for C. parapsilosis. SIGNIFICANCE AND IMPACT OF THE STUDY This work represents the first immunoproteomic analysis of C. parapsilosis, which provides new insights into host-pathogen interactions and pathogenesis of C. parapsilosis. The immunogenic proteins could be studied as biomarker candidates for C. parapsilosis.
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Affiliation(s)
- P Y Lee
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
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15
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Tan R, Ng KP, Gan GG, Na SL. Fusarium sp. infection in a patient with Acute Lymphoblastic Leukaemia. Med J Malaysia 2013; 68:479-480. [PMID: 24632920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In the past two decades, Fusarium species have been increasingly recognized as serious pathogens in immunocompromised patients. The outcome of fusariosis in the context of severe persistent neutropaenia has been almost universally fatal. The treatment of fusariosis in immunocompromised patients remains a challenge and the prognosis of systemic fusariosis in this population remains poor. This report presents a case of fatal fusariosis in a 37- year-old patient who was diagnosed with precursor-B cell Acute Lymphoblastic Leukaemia (ALL).
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Affiliation(s)
- R Tan
- University Malaya Medical Centre, Microbiology, Lembah Pantai, Kuala Lumpur, Wilayah Persekutuan 50603, Malaysia.
| | - K P Ng
- University Malaya Medical Centre, Microbiology, Lembah Pantai, Kuala Lumpur, Wilayah Persekutuan 50603, Malaysia
| | - G G Gan
- University Malaya Medical Centre, Microbiology, Lembah Pantai, Kuala Lumpur, Wilayah Persekutuan 50603, Malaysia
| | - S L Na
- University Malaya Medical Centre, Microbiology, Lembah Pantai, Kuala Lumpur, Wilayah Persekutuan 50603, Malaysia
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16
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Chin VK, Foong KJ, Maha A, Rusliza B, Norhafizah M, Ng KP, Chong PP. Candida albicans isolates from a Malaysian hospital exhibit more potent phospholipase and haemolysin activities than non-albicans Candida isolates. Trop Biomed 2013; 30:654-662. [PMID: 24522136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
This study was aimed at determining the phospholipase and haemolysin activity of Candida isolates in Malaysia. A total of 37 Candida clinical isolates representing seven species, Candida albicans (12), Candida tropicalis (8), Candida glabrata (4), Candida parapsilosis (1), Candida krusei (4), Candida orthopsilosis (1) and Candida rugosa (7) were tested. In vitro phospholipase activity was determined by using egg yolk plate assay whereas in vitro haemolysin activity was tested by using blood plate assay on sheep blood Sabouraud's dextrose agar (SDA) enriched with glucose. Phospholipase activity was detected in 75% (9 out of 12) of the C. albicans isolates. Among the 25 non- C. albicans Candida isolates, phospholipase activity was detected in only 24% of these isolates. The phospholipase activity of C. albicans was significantly higher than that of the non- C. albicans Candida isolates (P=0.002). Haemolysin activity was detected in 100% of the C. albicans, C. tropicalis, C. glabrata, C. krusei, C. parapsilosis, and C. orthopsilosis isolates while 75% of the C. krusei isolates and 12.3% of the C. rugosa isolates showed haemolysin activity. The haemolytic activity of C. albicans was significantly higher than that of the non- C. albicans Candida isolates (P=0.0001).The findings in this study indicate that C. albicans isolates in Malaysia may possess greater virulence potential than the non-albicans species.
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Affiliation(s)
- V K Chin
- Department of Biomedical Science, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia
| | - K J Foong
- Department of Biomedical Science, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia
| | - A Maha
- Department of Pathology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia
| | - B Rusliza
- Department of Human Anatomy, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia
| | - M Norhafizah
- Department of Pathology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia
| | - K P Ng
- Department of Microbiology, Faculty of Medicine, University of Malaya, Malaysia
| | - P P Chong
- Department of Biomedical Science, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia
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17
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Ng KP, Ngeow YF, K R, M R. Hepatitis B seroprevalence among University of Malaya Students in the Post-universal Infant Vaccination Era. Med J Malaysia 2013; 68:144-147. [PMID: 23629561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
AIM A nationwide HBV vaccination for neonates in the Expanded Programme on Immunization (EPI) was implemented in Malaysia in 1989. The objective of this study was to investigate the prevalence of HBsAg, anti-HBs and anti-HBc among the new student intakes in the Faculties of Medicine and Dentistry, University of Malaya from 2005 to 2011. MATERIALS AND METHODS All new students enrolled for undergraduate and postgraduate courses were screened for HBV infection. Serum samples collected were tested for the presence of HBsAg, anti-HBs and anti-HBc with the use of fully automated analysers. Statistical analyses were done using Open Epi version 2.3.1 RESULTS The overall HBsAg prevalence among the 2923 new intakes was 0.62%. The HBsAg prevalence rate was 1.08% (15/1390) for those born before 1989 and only 0.20% (3/1533) among those born in or after 1989. By year of testing, HBsAg prevalence declined steadily from 1.27% (5/394) in 2005 to 1.20% (5/418) in 2006, 0.95% (4/421) in 2007, 0.49% (2/410) in 2008, 0.49% (2/407) in 2009 and finally 0% in both 2010 (0/445) and 2011 (0/428). Although 66.14% of those vaccinated during infancy had no demonstrable immunity at the time of screening, only 6 (0.39%) students were found to have anti-HBc, including the 3 who were HBsAg positive. CONCLUSION These findings suggested effective prevention of HBV transmission with the universal and voluntary vaccination programs in Malaysia.
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Affiliation(s)
- K P Ng
- University of Malaya, Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia.
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18
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Ebrahem Q, Mahfouz RZ, Ng KP, Saunthararajah Y. High cytidine deaminase expression in the liver provides sanctuary for cancer cells from decitabine treatment effects. Oncotarget 2013; 3:1137-45. [PMID: 23087155 PMCID: PMC3717944 DOI: 10.18632/oncotarget.597] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
We document for the first time that sanctuary in an organ which expresses high levels of the enzyme cytidine deaminase (CDA) is a mechanism of cancer cell resistance to cytidine analogues. This mechanism could explain why historically, cytidine analogues have not been successful chemotherapeutics against hepatotropic cancers, despite efficacy in vitro. Importantly, this mechanism of resistance can be readily reversed, without increasing toxicity to sensitive organs, by combining cytidine analogue with an inhibitor of cytidine deaminase (tetrahydrouridine). Specifically, CDA rapidly metabolizes cytidine analogues into inactive uridine counterparts. Hence, to determine if sheltering/protection of cancer cells in organs which express high levels of CDA (e.g., liver) is a mechanism of resistance, we utilized a murine xenotransplant model of myeloid cancer that is sensitive to epigenetic therapeutic effects of the cytidine analogue decitabine in vitro and hepato-tropic in vivo. Treatment of tumor-bearing mice with decitabine (subcutaneous 0.2mg/kg 2X/week) doubled median survival and significantly decreased extra-hepatic tumor burden, but hepatic tumor burden remained substantial, to which the animals eventually succumbed. Combining a clinically-relevant inhibitor of CDA (tetrahydrouridine) with a lower dose of decitabine (subcutaneous 0.1mg/kg 2X/week) markedly decreased liver tumor burden without blood count or bone marrow evidence of myelotoxicity, and with further improvement in survival. In conclusion, sanctuary in a CDA-rich organ is a mechanism by which otherwise susceptible cancer cells can resist the effects of decitabine epigenetic therapy. This protection can be reversed without increasing myelotoxicity by combining tetrahydrouridine with a lower dose of decitabine.
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Affiliation(s)
- Quteba Ebrahem
- Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH, USA
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20
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Chong YB, Tan LP, Robinson S, Lim SK, Ng KP, Keng TC, Kamarulzaman A. Penicilliosis in lupus patients presenting with unresolved fever: a report of 2 cases and literature review. Trop Biomed 2012; 29:270-276. [PMID: 22735849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Penicilliosis is a rare occurrence among non human immunodeficiency virus (HIV) infected patients. We report here two cases of Penicillium marneffei infection in patients with systemic lupus erythematosus (SLE). Both patients had a recent flare of lupus and were on immunosuppressive drugs when they presented with prolonged fever without an obvious foci of infection, unresponsive to broad-spectrum antibiotics. They were leucopaenic upon admission, with rapid deterioration during the course of the illness. Diagnosis of penicilliosis via fungal isolation from blood culture was delayed resulting in the late initiation of antifungal agents. While both patients ultimately recovered, the delay in diagnosis led to a prolonged hospital stay with increased morbidity. Clinicians should be aware of this uncommon but emerging fungal pathogen in SLE patients and maintain a high index of suspicion in diagnosing this potentially fatal but treatable disease.
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Affiliation(s)
- Y B Chong
- Division of Nephrology, Department of Medicine, University Malaya Medical Centre, University of Malaya, Kuala Lumpur, Malaysia.
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Makishima H, Sugimoto Y, Szpurka H, Clemente MJ, Ng KP, Muramatsu H, O'Keefe C, Saunthararajah Y, Maciejewski JP. CBL mutation-related patterns of phosphorylation and sensitivity to tyrosine kinase inhibitors. Leukemia 2012; 26:1547-54. [PMID: 22246246 DOI: 10.1038/leu.2012.7] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Recurrent homozygous CBL-inactivating mutations in myeloid malignancies decrease ubiquitin ligase activity that inactivates SRC family kinases (SFK) and receptor tyrosine kinases (RTK). However, the most important SFK and RTK affected by these mutations, and hence, the most important therapeutic targets, have not been clearly characterized. We compared SFK and RTK pathway activity and inhibitors in acute myeloid leukemia cell lines containing homozygous R420Q mutation (GDM-1), heterozygous deletion (MOLM13) and wild-type (WT) CBL (THP1, U937). As expected with CBL loss, GDM-1 displayed high KIT expression and granulocyte-macrophage colony-stimulating factor (GM-CSF) hypersensitivity. Ectopic expression of WT CBL decreased GDM-1 proliferation but not cell lines with WT CBL. GDM-1, but not the other cell lines, was highly sensitive to growth inhibition by dasatinib (dual SFK and RTK inhibitor, LD50 50 nM); there was less or no selective inhibition of GDM-1 growth by sunitinib (RTK inhibitor), imatinib (ABL, KIT inhibitor), or PP2 (SFK inhibitor). Phosphoprotein analysis identified phosphorylation targets uniquely inhibited by dasatinib treatment of GDM-1, including a number of proteins in the KIT and GM-CSF receptor pathways (for example, KIT Tyr721, STAT3 Tyr705). In conclusion, the promiscuous effects of CBL loss on SFK and RTK signaling appear to be best targeted by dual SFK and RTK inhibition.
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Affiliation(s)
- H Makishima
- Department of Translational Hematology and Oncology Research, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH 44195, USA
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Sam IC, Karunakaran R, Kamarulzaman A, Ponnampalavanar S, Syed Omar SF, Ng KP, Mohd Yusof MY, Hooi PS, Jafar FL, Abubakar S. A large exposure to Brucella melitensis in a diagnostic laboratory. J Hosp Infect 2012; 80:321-5. [PMID: 22237130 DOI: 10.1016/j.jhin.2011.12.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Accepted: 12/02/2011] [Indexed: 11/30/2022]
Abstract
BACKGROUND Brucella species are easily transmitted by aerosols and can be acquired in the laboratory. AIM To report the management of a large exposure to Brucella melitensis that occurred over six days in a hospital diagnostic laboratory. METHODS Fifty-one exposed staff were managed according to Centers for Disease Control and Prevention guidelines. A further 96 non-exposed laboratory staff were tested for seroprevalence. Testing was carried out using the Brucella sp. serum agglutination test. FINDINGS Twenty-seven people had high-risk exposure and 24 had low-risk exposure. High-risk staff were offered post-exposure prophylaxis. Twelve (44.4%) agreed to this, of whom eight (66.7%) completed the course. Overall compliance with serological follow-up at baseline, 2, 4, 6 weeks and 8 months was 45.9%. Despite this poor compliance there were no clinical brucellosis cases and no seroconversion in the 47.1% of staff tested at 8 months. Brucella sp. seroprevalence among all staff tested was 3/147 (2.0%). CONCLUSION Lack of experience with Brucella spp. and lack of policies for handling potentially hazardous organisms contributed to this prolonged exposure. As compliance with current recommendations may be poor, the optimum frequency of serological follow-up and target groups for prophylaxis should be reassessed. Laboratories in low- or non-endemic areas must prepare for potential isolation of Brucella spp. The impact of human brucellosis in Malaysia requires further study.
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Affiliation(s)
- I-C Sam
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
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Abstract
BACKGROUND Severe acute kidney injury (AKI) occurs in 2-7% of all hospital admissions and is an independent poor prognostic marker. Nevertheless, information on the long-term outcome of AKI and the factors influencing this is limited. AIM To describe the short- and long-term outcome of patients requiring renal replacement therapy (RRT) for severe AKI and to examine factors affecting patient survival and renal recovery. DESIGN AND METHODS Single centre retrospective analysis of 481 consecutive patients over a period of 39 months. FOLLOW-UP 12 months. PRIMARY AND SECONDARY OUTCOMES overall mortality and RRT dependency at 30 days, 90 days and 1 year. RESULTS Survival at 30 days, 90 days and 1 year was 54.4, 47.2 and 37.6%, respectively. RRT independency at 30 days, 90 days and 1 year was 35.2, 27.2 and 25.8%, respectively. Of those RRT independent at 90 days, 55% had ongoing chronic kidney disease. There were two distinct groups of patients: Group A (haemofiltration in ITU) and Group B (intermittent haemodialysis in the renal unit). Patient survival was worse in Group A while RRT independence was higher. Independent predictors of survival included renal cause of AKI and lower CI score in Group A and renal or post-renal cause of AKI, younger age and the absence of malignancy in Group B. Independent predictors of renal recovery included the presence of sepsis in Group A and pre- or post-renal cause of AKI in Group B. CONCLUSIONS The short- and long-term survival outcome of severe AKI requiring RRT remains poor. Among those who survive, a significant number either continue to require RRT or have residual renal impairment necessitating ongoing follow-up.
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Affiliation(s)
- K P Ng
- Renal Department, Birmingham Heartlands Hospital, Heart of England NHS Foundation Trust, Birmingham, UK.
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Karunakaran R, Halim HA, Ng KP, Hanifah YA, Chin E, Jaafar FL, Abubakar S. Tsukamurella tyrosinosolvens intravascular catheter-related bacteremia in a haematology patient: a case report. Eur Rev Med Pharmacol Sci 2011; 15:1343-1346. [PMID: 22195371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Tsukamurella spp. are a rare but important cause of intravascular catheter-related bacteremia in immunocompromised patients. The organism is an aerobic, Gram-positive, weakly acid-fast bacillus that is difficult to differentiate using standard laboratory methods from other aerobic actinomycetales such as Nocardia spp., Rhododoccus spp., Gordonia spp., and the rapid growing Mycobacterium spp. We report a case of Tsukamurella tyrosinosolvens catheter-related bacteremia in a 51-year-old haematology patient who responded to treatment with imipenem and subsequent line removal. 16srRNA sequencing allowed for the prompt identification of this organism.
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Affiliation(s)
- R Karunakaran
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia.
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25
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Negrotto S, Ng KP, Jankowska AM, Bodo J, Gopalan B, Guinta K, Mulloy JC, Hsi E, Maciejewski J, Saunthararajah Y. CpG methylation patterns and decitabine treatment response in acute myeloid leukemia cells and normal hematopoietic precursors. Leukemia 2011; 26:244-54. [PMID: 21836612 PMCID: PMC3217177 DOI: 10.1038/leu.2011.207] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The DNA hypomethylating drug decitabine maintains normal hematopoietic stem cell (HSC) self-renewal but induces terminal differentiation in acute myeloid leukemia (AML) cells. The basis for these contrasting cell-fates, and for selective CpG hypomethylation by decitabine, is poorly understood. Promoter CpGs, with methylation measured by microarray, were classified by the direction of methylation change with normal myeloid maturation. In AML cells, the methylation pattern at maturation-responsive CpG suggested at least partial maturation. Consistent with partial maturation, in gene expression analyses, AML cells expressed high levels of the key lineage-specifying factor CEBPA, but relatively low levels of the key late-differentiation driver CEBPE. In methylation analysis by mass-spectrometry, CEBPE promoter CpG that are usually hypomethylated during granulocyte maturation were significantly hypermethylated in AML cells. Decitabine treatment induced cellular differentiation of AML cells, and the largest methylation decreases were at CpG that are hypomethylated with myeloid maturation, including CEBPE promoter CpG. In contrast, decitabine-treated normal HSC retained immature morphology, and methylation significantly decreased at CpG that are less methylated in immature cells. High expression of lineage-specifying factor and aberrant epigenetic repression of some key late-differentiation genes distinguishes AML cells from normal HSC and could explain the contrasting differentiation and methylation responses to decitabine.
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Affiliation(s)
- S Negrotto
- Department of Translational Hematology and Oncology Research, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH 44195, USA.
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Madhavan P, Jamal F, Chong PP, Ng KP. Identification of local clinical Candida isolates using CHROMagar Candida™ as a primary identification method for various Candida species. Trop Biomed 2011; 28:269-274. [PMID: 22041745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The objective of our study was to study the effectiveness of CHROMagar Candida™ as the primary identification method for various clinical Candida isolates, other than the three suggested species by the manufacturer. We studied 34 clinical isolates which were isolated from patients in a local teaching hospital and 7 ATCC strains. These strains were first cultured in Sabouraud dextrose broth (SDB) for 36 hours at 35ºC, then on CHROMagar plates at 30ºC, 35ºC and 37ºC. The sensitivity of this agar to identify Candida albicans, Candida dubliniensis, Candida tropicalis, Candida glabrata, Candida rugosa, Candida krusei and Candida parapsilosis ranged between 25 and 100% at 30ºC, 14% and 100% at 35ºC, 56% and 100% at 37ºC. The specificity of this agar was 100% at 30ºC, between 97% and 100% at 35ºC, 92% and 100% at 37ºC. The efficiency of this agar ranged between 88 and 100% at 30ºC, 83% and 100% at 35ºC, 88% and 100% at 37ºC. Each species also gave rise to a variety of colony colours ranging from pink to green to blue of different colony characteristics. Therefore, the chromogenic agar was found to be useful in our study for identifying clinical Candida isolates.
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Affiliation(s)
- P Madhavan
- Department of Medical Microbiology and Parasitology, Faculty of Medicine and Health Sciences, University Putra Malaysia, Serdang, Selangor, Malaysia.
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Negrotto S, Hu Z, Alcazar O, Ng KP, Triozzi P, Lindner D, Rini B, Saunthararajah Y. Noncytotoxic differentiation treatment of renal cell cancer. Cancer Res 2011; 71:1431-41. [PMID: 21303982 DOI: 10.1158/0008-5472.can-10-2422] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Current drug therapy for metastatic renal cell cancer (RCC) results in temporary disease control but not cure, necessitating continued investigation into alternative mechanistic approaches. Drugs that inhibit chromatin-modifying enzymes involved in transcription repression (chromatin-relaxing drugs) could have a role, by inducing apoptosis and/or through differentiation pathways. At low doses, the cytosine analogue decitabine (DAC) can be used to deplete DNA methyl-transferase 1 (DNMT1), modify chromatin, and alter differentiation without causing apoptosis (cytotoxicity). Noncytotoxic regimens of DAC were evaluated for in vitro and in vivo efficacy against RCC cell lines, including a p53-mutated RCC cell line developed from a patient with treatment-refractory metastatic RCC. The cell division-permissive mechanism of action-absence of early apoptosis or DNA damage, increase in expression of HNF4α (hepatocyte nuclear factor 4α), a key driver associated with the mesenchymal to epithelial transition, decrease in mesenchymal marker expression, increase in epithelial marker expression, and late increase in cyclin-dependent kinase inhibitor CDKN1B (p27) protein-was consistent with differentiation-mediated cell-cycle exit. In vivo blood counts and animal weights were consistent with minimal toxicity of therapy. The distinctive mechanism of action of a dose and schedule of DAC designed for noncytotoxic depletion of DNMT1 suggests a potential role in treating RCC.
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Affiliation(s)
- Soledad Negrotto
- Department of Translational Hematology and Oncology Research, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio, USA
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28
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Madhavan P, Jamal F, Chong PP, Ng KP. In vitro activity of fluconazole and voriconazole against clinical isolates of Candida spp. by E-test method. Trop Biomed 2010; 27:200-207. [PMID: 20962716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The in vitro susceptibility of clinical Candida isolates towards fluconazole and voriconazole was determined using the E-test method. A total of 41 clinical isolates recovered from patients since 2004 until 2009 from two local hospitals in Kuala Lumpur, Malaysia were used. These comprised Candida tropicalis, Candida albicans, Candida krusei, Candida parapsilosis, Candida rugosa, Candida dubliniensis and Candida glabrata. Strains from American Type Culture Collection were used as quality control. Lawn cultures of the isolates on RPMI-1640 agar medium supplemented with 2% glucose were incubated with the E-test strips at 35ºC for 48 h. Our results show that 71% were susceptible to fluconazole and 90% were susceptible to voriconazole. All strains of C. krusei were resistant to fluconazole and 50% were susceptible in a dose-dependent manner to voriconazole. There were 66% and 33% of C. glabrata that were resistant to fluconazole and voriconazole. Our study revealed that majority of the clinical Candida isolates was susceptible to fluconazole and voriconazole with a small percentage being resistant to both the drugs.
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Affiliation(s)
- P Madhavan
- Department of Medical Microbiology and Parasitology, Faculty of Medicine and Health Sciences, University Putra Malaysia, Serdang, Selangor, Malaysia
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Hu Z, Negrotto S, Gu X, Mahfouz R, Ng KP, Ebrahem Q, Copelan E, Singh H, Maciejewski JP, Saunthararajah Y. Decitabine maintains hematopoietic precursor self-renewal by preventing repression of stem cell genes by a differentiation-inducing stimulus. Mol Cancer Ther 2010; 9:1536-43. [PMID: 20501800 DOI: 10.1158/1535-7163.mct-10-0191] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The cytosine analogue decitabine alters hematopoietic differentiation. For example, decitabine treatment increases self-renewal of normal hematopoietic stem cells. The mechanisms underlying decitabine-induced shifts in differentiation are poorly understood, but likely relate to the ability of decitabine to deplete the chromatin-modifying enzyme DNA methyltransferase 1 (DNMT1), which plays a central role in transcription repression. HOXB4 is a transcription factor that promotes hematopoietic stem cell self-renewal. In hematopoietic precursors induced to differentiate by the lineage-specifying transcription factor Pu.1 or by the cytokine granulocyte-colony stimulating factor, there is rapid repression of HOXB4 and other stem cell genes. Depletion of DNMT1 using shRNA or decitabine prevents HOXB4 repression by Pu.1 or granulocyte-colony stimulating factor and maintains hematopoietic precursor self-renewal. In contrast, depletion of DNMT1 by decitabine 6 hours after the differentiation stimulus, that is, after repression of HOXB4 has occurred, augments differentiation. Therefore, DNMT1 is required for the early repression of stem cell genes, which occurs in response to a differentiation stimulus, providing a mechanistic explanation for the observation that decitabine can maintain or increase hematopoietic stem cell self-renewal in the presence of a differentiation stimulus. Using decitabine to deplete DNMT1 after this early repression phase does not impair progressive differentiation.
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Affiliation(s)
- Zhenbo Hu
- Department of Translational Hematology and Oncology Research, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio 44195, USA
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Pattanaik P, Fromondi L, Ng KP, He J, van den Akker F. Expression, purification, and characterization of the intra-cellular domain of the ANP receptor. Biochimie 2009; 91:888-93. [PMID: 19393286 DOI: 10.1016/j.biochi.2009.04.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2008] [Accepted: 04/15/2009] [Indexed: 11/25/2022]
Abstract
The membrane-bound atrial natriuretic peptide receptor (GCA) catalyzes the formation of cGMP from GTP in response to natriuretic peptide hormones. Previous structural studies have focused on the extra-cellular hormone binding domain of this receptor whereas its intra-cellular domain has not yet been amenable to such studies. We report here the baculovirus expression and purification of the GCA intra-cellular domain construct GCA(ID) comprising the complete intra-cellular region which includes the kinase-homology domain, coiled-coil region, and catalytic cyclase domain. The intra-cellular domain was enzymatically characterized in terms of guanylyl cyclase activity and the effects of ATP, manganese, and Triton X-100. Our results indicate that the activity of the intra-cellular domain of the ANP receptor is about 2 fold less active compared to a truncated cyclase domain construct lacking the kinase-like domain that was also expressed and purified. In addition, unlike the full length receptor, the intra-cellular domain could not be activated by Triton X-100/Mn(2+) or its activity stimulated by ATP. These data therefore indicate that the major part of the transition from the basal state to the fully, ANP/ATP-dependent, activated state as well its stimulation/enhancement by Triton X-100/Mn(2+) requires the full length receptor. These receptor insights could aid in the development of novel therapeutics as the GCA receptor is a key drug target for cardiovascular diseases.
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Affiliation(s)
- Priyaranjan Pattanaik
- Department of Biochemistry/RT500, Case Western Reserve University, 10900 Euclid Av., Cleveland, OH 44106, USA
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Sultan SM, Ng KP, Edwards JCW, Isenberg DA, Cambridge G. Clinical outcome following B cell depletion therapy in eight patients with refractory idiopathic inflammatory myopathy. Clin Exp Rheumatol 2008; 26:887-893. [PMID: 19032824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
OBJECTIVE To assess the efficacy of B lymphocyte depletion therapy (BCDT) in patients with refractive idiopathic inflammatory myopathy (IIM). METHODS Eight patients thought to have IIM were treated with BCDT utilising rituximab. Five were treated as part of an open label trial and three on the basis of perceived clinical need. Rituximab (1 gram) and methylprednisolone (100 mg) were given as intravenous infusions on days 0 and 14. The primary efficacy outcome at 6 months was 15% improvement in muscle strength and 30% reduction in CPK. RESULTS Two patients with Jo-1 antibody positive dermatomyositis (DM) demonstrated a clinical response. Both achieved >30% improvement in CPK. In one, the CPK remained within the normal range for 10 months, the other had a normalised CPK and stabilisation of lung function tests for 36 months. Muscle strength by myometry, however, did not achieve the primary outcome, although, patient 1, demonstrated an improvement of 20% at 8 months (the patient had elective surgery of the hand during the study period). Jo-1 antibody levels fell modestly in both patients but remained detectable. Re-evaluation of three patients revealed that one had inclusion body myositis, one had sporadic muscular dystrophy and one subsequently developed nodular sclerosing lymphoma. All except one patient showed adequate B cell depletion with re-population occurring 3- >42 months after BCDT. One patient did not deplete and died of an unrelated cause. CONCLUSIONS This study emphasizes the importance of identifying and selecting the appropriate sub-group of patients with IIM most likely to respond to BCDT.
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Affiliation(s)
- S M Sultan
- University College London Hospital, London, UK
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Fukuyama R, Ng KP, Cicek M, Kelleher C, Niculaita R, Casey G, Sizemore N. Role of IKK and oscillatory NFkappaB kinetics in MMP-9 gene expression and chemoresistance to 5-fluorouracil in RKO colorectal cancer cells. Mol Carcinog 2007; 46:402-13. [PMID: 17186550 DOI: 10.1002/mc.20288] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Nuclear factor kappa B (NFkappaB) is a central participant in the metastasis and chemoresistance of colorectal cancer (CRC). However, it is not fully understood to what extent NFkappaB contributes to induction of the metastasis-associated matrix metalloprotease-9 (MMP-9) gene and sensitivity to the commonly used chemotherapeutic 5-fluorouracil (5-Fu) in CRC. Using the RKO human CRC cell line and two NFkappaB signaling deficient RKO mutants, we investigated NFkappaB's role in the induction of MMP-9 and 5-Fu sensitivity in RKO CRC cells. NFkappaB plays a predominant role in MMP-9 gene induction in RKO cells, as evidenced by the failure of tumor necrosis factor alpha (TNFalpha) to induce MMP-9 in either of the NFkappaB signaling mutants. RKO cells exhibit a robust, oscillatory NFkappaB activity in response to TNFalpha not seen in either of the NFkappaB mutant cell lines, which instead demonstrate diminished, nonoscillatory NFkappaB activation. Analysis of TNFalpha-induced phosphorylation and MMP-9 promoter recruitment of the p65 NFkappaB subunit revealed a significant reduction in p65 phosphorylation as well as reduced and altered recruitment of p65 to the MMP-9 gene promoter in the mutants compared to the parental RKO cell line. 5-Fu only activated NFkappaB in the parental RKO cells through induction of IkappaB-kinase (IKK) activity and increased sensitivity to 5-Fu is observed in both NFkappaB mutant lines. Our results suggest that TNFalpha-dependent induction of MMP-9 gene expression is tightly regulated by oscillatory/cumulative activation of NFkappaB and that 5-Fu stimulates NFkappaB and RKO CRC cell survival through induction of IKK activity.
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Affiliation(s)
- Ryuichi Fukuyama
- Department of Cancer Biology, Cleveland Clinic, Cleveland, Ohio 44195, and School of Biomedical Sciences, Kent State University, USA
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Ng KP, Smith CR, Isenberg DA. Muscular dystrophy mimicking refractory idiopathic inflammatory myositis: a trio of cases. Rheumatology (Oxford) 2007; 46:1618-9. [PMID: 17704520 DOI: 10.1093/rheumatology/kem196] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Sizemore S, Cicek M, Sizemore N, Ng KP, Casey G. Podocalyxin increases the aggressive phenotype of breast and prostate cancer cells in vitro through its interaction with ezrin. Cancer Res 2007; 67:6183-91. [PMID: 17616675 DOI: 10.1158/0008-5472.can-06-3575] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Podocalyxin is an anti-adhesive transmembrane sialomucin that has been implicated in the development of more aggressive forms of breast and prostate cancer. The mechanism through which podocalyxin increases cancer aggressiveness remains poorly understood but may involve the interaction of podocalyxin with ezrin, an established mediator of metastasis. Here, we show that overexpression of podocalyxin in MCF7 breast cancer and PC3 prostate cancer cell lines increased their in vitro invasive and migratory potential and led to increased expression of matrix metalloproteases 1 and 9 (MMP1 and MMP9). Podocalyxin expression also led to an increase in mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3K) activity. To determine the role of ezrin in these podocalyxin-dependent phenotypic events, we first confirmed that podocalyxin formed a complex with ezrin in MCF7 and PC3 cells. Furthermore, expression of podocalyxin was associated with a changed ezrin subcellular localization and increased ezrin phosphorylation. Transient knockdown of ezrin protein abrogated MAPK and PI3K signaling as well as MMP expression and invasiveness in cancer cells overexpressing podocalyxin. These findings suggest that podocalyxin leads to increased in vitro migration and invasion, increased MMP expression, and increased activation of MAPK and PI3K activity in MCF7 and PC3 cells through its ability to form a complex with ezrin.
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Affiliation(s)
- Steven Sizemore
- Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195, USA
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Chan AOK, Lam CW, Tong SF, Cheng MT, Yung K, Chan YW, Au KM, Yuen YP, Hung CT, Ng KP, Shek CC. Gene symbol: BCHE. Hum Genet 2007; 121:288. [PMID: 17598201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Affiliation(s)
- A O K Chan
- Chemical Pathology Laboratory, Queen Elizabeth Hospital, Kowloon, Hong Kong.
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Chan AOK, Lam CW, Tong SF, Tung CM, Yung K, Chan YW, Au KM, Yuen YP, Hung CT, Ng KP, Shek CC. Gene symbol: BCHE. Hum Genet 2007; 121:289. [PMID: 17598228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Affiliation(s)
- A O K Chan
- Chemical Pathology Laboratory, Queen Elizabeth Hospital, Kowloon, Hong Kong.
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Pfaller MA, Diekema DJ, Colombo AL, Kibbler C, Ng KP, Gibbs DL, Newell VA. Candida rugosa, an emerging fungal pathogen with resistance to azoles: geographic and temporal trends from the ARTEMIS DISK antifungal surveillance program. J Clin Microbiol 2006; 44:3578-82. [PMID: 17021085 PMCID: PMC1594768 DOI: 10.1128/jcm.00863-06] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Candida rugosa is a fungus that appears to be emerging as a cause of infection in some geographic regions. We utilized the extensive database of the ARTEMIS DISK Antifungal Surveillance Program to describe the geographic and temporal trends in the isolation of C. rugosa from clinical specimens and the in vitro susceptibilities of 452 isolates to fluconazole and voriconazole. C. rugosa accounted for 0.4% of 134,715 isolates of Candida, and the frequency of isolation increased from 0.03% to 0.4% over the 6.5-year study period (1997 to 2003). C. rugosa was most common in the Latin American region (2.7% versus 0.1 to 0.4%). Decreased susceptibility to fluconazole (40.5% susceptible) was observed in all geographic regions; however, isolates from Europe and North America were much more susceptible (97 to 100%) to voriconazole than those from other geographic regions (55.8 to 58.8%). C. rugosa was most often isolated from blood and urine in patients hospitalized at the Medical and Surgical inpatient services. Notably, bloodstream isolates were the least susceptible to both fluconazole and voriconazole. C. rugosa should be considered, along with the established pathogens Candida krusei and Candida glabrata, as a species of Candida with reduced susceptibility to the azole antifungal agents.
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Affiliation(s)
- M A Pfaller
- Medical Microbiology Division, C606 GH, Department of Pathology, University of Iowa College of Medicine, Iowa City, IA 52242, USA.
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Tay ST, Tanty Haryanty T, Ng KP, Rohani MY, Hamimah H. In vitro susceptibilities of Malaysian clinical isolates of Cryptococcus neoformans var. grubii and Cryptococcus gattii to five antifungal drugs. Mycoses 2006; 49:324-30. [PMID: 16784448 DOI: 10.1111/j.1439-0507.2006.01242.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The in vitro susceptibilities of Malaysian clinical isolates of Cryptococcus neoformans var. grubii and C . gattii to five antifungal drugs (amphotericin B, flucytosine, fluconazole, itraconazole and ketoconazole) were determined using the Etest method. None of the Malaysian isolates was resistant to amphotericin B and ketoconazole. Isolates resistant to flucytosine, fluconazole and itraconazole were observed in this study. Minimum inhibition concentrations (MICs) of > or = 32 microg ml(-1) against flucytosine, > or = 64 microg ml(-1) against fluconazole and > or = 1 microg ml(-1) against itraconazole were noted in four (8.3%), two (4.2%) and one (2.1%) isolates respectively. There was no significant difference in the MICs for both Cryptococcus species (P > 0.05), indicating that C. gattii was as susceptible as var. grubii to all the antifungal drugs tested. No significant difference in the MICs for both Cryptococcus species collected from 1980 to 1990 and 2002 to 2004 were observed (P > 0.05).
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Affiliation(s)
- S T Tay
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur.
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Tay ST, Chai HC, Na SL, Ng KP. Molecular subtyping of clinical isolates of Candida albicans and identification of Candida dubliniensis Malaysia. Mycopathologia 2006; 159:325-9. [PMID: 15883714 DOI: 10.1007/s11046-004-6269-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2004] [Revised: 11/12/2004] [Indexed: 11/29/2022]
Abstract
The genotypes of 221 recent isolates of Candida albicans from various clinical specimens of 213 patients admitted to the University Malaya Medical Centre, Malaysia was determined based on the amplification of a transposable intron region in the 25 S rRNA gene. The analyses of 178 C. albicans isolated from nonsterile clinical specimens showed that they could be classified into three genotypes: genotype A (138 isolates), genotype B (38 isolates) and genotype C (2 isolates). The genotyping of 43 clinical isolates from sterile specimens showed that they belonged to genotype A (29 isolates), genotype B (10 isolates), genotype C (2 isolates) and genotype D (2 isolates). The overall distribution of C. albicans genotypes in sterile and nonsterile specimens appeared similar, with genotype A being the most predominant type. This study reported the identification of C. dubliniensis (genotype D) in 2 HIV-negative patients with systemic candidiasis, which were missed by the routine mycological procedure. The study demonstrated the genetic diversity of clinical isolates of C. albicans in Malaysia.
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Affiliation(s)
- S T Tay
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia.
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Ng KP, Manson JJ, Rahman A, Isenberg DA. Association of antinucleosome antibodies with disease flare in serologically active clinically quiescent patients with systemic lupus erythematosus. ACTA ACUST UNITED AC 2006; 55:900-4. [PMID: 17139667 DOI: 10.1002/art.22356] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE To identify the prevalence of serologically active clinically quiescent (SACQ) patients in a cohort of 290 patients with systemic lupus erythematosus (SLE). We investigated if the presence of anti-double-stranded DNA (anti-dsDNA) or antinucleosome (anti-NCS) antibodies during the SACQ period was associated with future flares. METHODS SACQ patients defined as clinically inactive for 6 months (global British Isles Lupus Activity Group index [BILAG] scores <6) and serologically active (anti-dsDNA antibodies >50 units/ml on at least 2 occasions by enzyme-linked immunosorbent assay [ELISA]) were identified. Patient sera collected during the defined SACQ period were also tested for anti-NCS antibodies (ELISA). We retrospectively reviewed patient clinical details and episodes of flare using the BILAG activity index. RESULTS Twenty-seven (9%) patients were SACQ. Seventeen (81%) patients experienced a flare (total of 91 flares, up to 12 flares per person) in the next 5 years. Median duration to first flare was 15 months (range 2-46). Time to first flare after SACQ period was significantly correlated with the presence of anti-NCS (P = 0.0012), high anti-NCS antibody titers (P = 0.0006), and anti-dsDNA titers 5 times above the normal limit (P = 0.02). Patients with higher absolute anti-NCS antibody titers showed a significant correlation with the number of flares (r = 0.57, P = 0.007). CONCLUSION A minority of patients with SLE are SACQ. The majority of these patients experience a flare in the next 5 years and close followup is recommended. Anti-NCS antibodies may be a better predictor than anti-dsDNA antibodies for future flares.
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Affiliation(s)
- K P Ng
- University College London, London, UK
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Rasool S, Siar CH, Ng KP. Oral candidal species among smokers and non-smokers. J Coll Physicians Surg Pak 2005; 15:679-82. [PMID: 16300700 DOI: 11.2005/jcpsp.679682] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 01/17/2005] [Accepted: 09/06/2005] [Indexed: 11/07/2022]
Abstract
OBJECTIVE To determine the various oral Candidal species among healthy Malaysian adults. DESIGN Case-control study. PLACE AND DURATION OF STUDY This study was collaborated between the Department of Medical Microbiology, Faculty of Medicine and Department of Oral Pathology, Oral Medicine and Periodontology, Faculty of Dentistry, University of Malaya, Kuala Lumpur, Malaysia, between September 2002 till January 2004. PATIENTS AND METHODS One hundred adults (50 smokers and 50 non-smokers), aged between 40 and 70 years were studied. Swabs and carbohydrate assimilation (Saboraud Dextrose Agar, Corn Meal Agar, API 20C AUX System) were performed. Specimens were collected from dorsum of the tongue, buccal mucosa and commissures (right and left each). Colony forms were established by positive colony forming units, on SDA medium (24-48 hours). Germ tube test for (true/pseudohyphae) growth was done on Corn Meal Agar Medium. Candida biotypes were evaluated by API 20C AUX system, which had a numerical 7 digit profile, added to evaluate a definite Candida species. RESULTS Thirty-five percent of Malaysian adults harbored Candida intraorally. Candidal species identified among 100 subjects had C. albicans (27) 77%, C. glabrata (3) 8%, C. famata, C. tropicalis, C. krusei, C. lusitaniae and C. guilliermondii (1) 3% each. Thirty-three positive cases comprised of 35 species i.e. two cases had two species each. Fifty seven percent of these were smokers and 43% non-smokers. These included 40% Chinese, 36% Malays and 24% Indians. Species were, however, not specified according to intra-oral sites i.e. buccal, commissural mucosa and dorsum of tongue. CONCLUSION On this series C. albicans is the most common species found in the oral cavity of Malaysian adults. It is equally frequent in smokers and non-smokers, but showed a predilection for the ethnic Chinese group.
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Affiliation(s)
- S Rasool
- Department of Oral Pathology, Altamash Institute of Dental Medicine, Karachi.
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Ng KP, Leandro MJ, Edwards JC, Ehrenstein MR, Cambridge G, Isenberg DA. Repeated B cell depletion in treatment of refractory systemic lupus erythematosus. Ann Rheum Dis 2005; 65:942-5. [PMID: 16269424 PMCID: PMC1798232 DOI: 10.1136/ard.2005.044487] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
OBJECTIVES To report the clinical outcome and safety profile of repeated B cell depletion in seven patients with refractory systemic lupus erythematosus (SLE). METHODS Since June 2000, seven patients with refractory SLE had repeated cycles of B cell depletion (18 cycles in total, up to three cycles per patient) because of disease relapse. The clinical response (assessed by the British Isles Lupus Activity Guide (BILAG) activity index), duration of B cell depletion, and adverse events in these patients was reviewed. RESULTS Four patients (Nos 1, 2, 3, 6) had three cycles of treatment and three (Nos 4, 5, 7) had two cycles. Four of the seven patients (Nos 1, 3, 5, 6) improved. The mean global BILAG scores dropped from 15 to 6 at 5-7 months. The median duration of clinical response and B cell depletion was 13 months and 6 months, respectively. After the third cycle, 2/4 patients (Nos 1 and 2) improved. The median duration of clinical benefit was 12 months. Most patients tolerate re-treatment very well. CONCLUSION Re-treatment with B cell depletion of patients with severe SLE is safe and may be effective for 6-12 months on average.
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Affiliation(s)
- K P Ng
- Centre for Rheumatology, University College London, Arthur Stanley House, 40-50 Tottenham Street, London W1T 4NJ, UK
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Ng KP, Soo-Hoo TS, Na SL, Tay ST, Hamimah H, Lim PC, Chong PP, Seow HF, Chavez AJ, Messer SA. The mycological and molecular study of Hortaea werneckii isolated from blood and splenic abscess. Mycopathologia 2005; 159:495-500. [PMID: 15983734 DOI: 10.1007/s11046-005-1154-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2004] [Accepted: 01/06/2005] [Indexed: 10/25/2022]
Abstract
Hortaea werneckii is an environmental dematiaceous fungus found in the halophilic environment. It causes tinea nigra. We report the isolation of H. werneckii from blood and splenic abscess of two patients with acute myelomonocytic leukaemia. H. werneckii grew at room temperature but not at 37 degrees C, it was identified by biochemical tests, growth characteristics and the presence of conspicuous collarette intercalary on dividing yeast cells. The use of specific oligonucleotide primer Hor-F (5'-TGGACACCTTCA TAACTCTTG-3') and Hor-R (5'-TCACAACGCTTAGAGACGG-3') confirmed the two isolates were H. werneckii. The sequence for 281 nucleotide of HW299 and HW403 were 99% identical but differed only in one nucleotide. In vitro anti-fungal susceptibility testing showed that the isolates were resistant to amphotericin B and flucytosine.
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Affiliation(s)
- K P Ng
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia.
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Ng KP, Saw TL, Baki A, Rozainah K, Pang KW, Ramanathan M. Impact of the Expanded Program of Immunization against hepatitis B infection in school children in Malaysia. Med Microbiol Immunol 2005; 194:163-8. [PMID: 15834754 DOI: 10.1007/s00430-004-0231-4] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2004] [Indexed: 12/21/2022]
Abstract
The implementation of the Expanded Program of Immunization (EPI) in 1989 has dramatic impact on hepatitis B virus (HBV) infection in school children in Malaysia. A cross-sectional seroprevalence study of HBV infection in 190,077 school children aged 7-12 years from 1997 to 2003 showed a steady decline of HBV surface antigen (HBsAg) prevalence rate from 2.5% for children born in 1985 to 0.4% among school children born in 1996. The overall prevalence of HBsAg was 0.6%, 0.7% in males and 0.6% in females. Over 92.7% of school children had been vaccinated with HBV vaccine, in which 93.7% were vaccinated under the EPI and 6.3% on voluntary basis. The school children vaccinated under EPI had a 0.4% HBsAg carrier rate, which was significantly lower than school children vaccinated on a voluntary basis (HBsAg carrier rate 1.3%) and non-vaccinated school children (HBsAg carrier rate 2.7%), suggesting that HBV vaccination of infants was the most effective measure in preventing vertical transmission of HBV in the hyperendemic region.
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Affiliation(s)
- K P Ng
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia.
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Puthucheary SD, Ng KP, Hafeez A, Raja NS, Hassan HH. Salmonellosis in persons infected with human immunodeficiency virus: a report of seven cases from Malaysia. Southeast Asian J Trop Med Public Health 2004; 35:361-5. [PMID: 15691137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
Persons infected with human immunodeficiency virus (HIV) have an increased risk of salmonellosis when compared to the general population. We describe seven such patients with Salmonella bacteremia, of whom two had recurrent salmonellosis. In the latter two cases the infection was unusually severe, characterized by widespread infection, bacteremia and relapse, despite standard antimicrobial therapy. HIV-infected individuals will benefit from education on the source of Salmonella, mode of acquisition and prevention through safe food handling and food preparation practices. Because of the difficulty of eradicating Salmonella infection in patients with acquired immunodeficiency syndrome, long-term suppressive treatment with antimicrobials is warranted.
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Affiliation(s)
- S D Puthucheary
- Department of Medical Microbiology, University of Malaya Medical Center, Kuala Lumpur, Malaysia.
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Ghazali O, Chua KB, Ng KP, Hooi PS, Pallansch MA, Oberste MS, Chua KH, Mak JW. An outbreak of acute haemorrhagic conjunctivitis in Melaka, Malaysia. Singapore Med J 2004; 44:511-6. [PMID: 15024454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/28/2022]
Abstract
This paper reports a second outbreak of acute haemorrhagic conjunctivitis due to coxsackievirus A24 in peninsular Malaysia. Between June 2002 and early October 2003, 10,327 patients, comprising 3,261 children and 7,066 adults, were treated for acute conjunctivitis in 11 government health clinics in the Melaka Tengah district of the state of Melaka. The figure grossly underestimates the size of the outbreak; as no patients treated in private clinics in the same district were included. Institution and household surveillance showed that the commonest presenting clinical feature of the illness was eye-discharge (91.2%), followed by foreign body sensation (81.8%), pain (78.3%) and subconjunctival haemorrhage (74.4%). The mean duration of illness was 6.5 and five days for patients with and without subconjunctival haemorrhage respectively.
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Affiliation(s)
- O Ghazali
- Pejabat Kesihatan Daerah, Melaka Tengah, Melaka 75150, Malaysia.
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Ng KP, Soo-Hoo TS, Na SL, Gan GG, Sangkar JV, Teh AK. Scopulariopsis brevicaulis infection in a patient with acute myeloid leukemia. Med J Malaysia 2003; 58:608-12. [PMID: 15190640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
Scopulariopsis brevicaulis is a soil fungus normally associated with onychomycosis. It causes subcutaneous infection in immunocompromised patients and is rarely isolated from blood. A case of systemic Scopulariopsis brevicaulis infection was reported in a patient with acute myeloid leukemia. The patient developed persistent fever that did not respond to wide spectrum antibiotics and amphotericin B. Scopulariopsis brevicaulis was the only pathogen isolated from blood cultures. The fever subsided with itraconazole and there was no recurrence of fungal infection with prolonged maintenance of oral itraconazole.
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Affiliation(s)
- K P Ng
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur
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Ng KP, Saw TL, Baki A, Kamarudin R. Evaluation of three commercial rapid tests for detecting antibodies to human immunodeficiency virus. Med J Malaysia 2003; 58:454-60. [PMID: 14750391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
Abstract
Determine HIV-1/2, Chembio HIV-1/2 STAT-PAK and PenTest are simple/rapid tests for the detection of antibodies to HIV-1 and HIV-2 in human whole blood, serum and plasma samples. The assay is one step and the result is read visually within 15 minutes. Using 92 known HIV-1 reactive sera and 108 known HIV-1 negative sera, the 3 HIV tests correctly identified all the known HIV-1 reactive and negative samples. The results indicated that Determine HIV-1/2, Chembio HIV-1/2 STAT-PAK and PenTest HIV are as sensitive and specific (100% concordance) as Microparticle Enzyme Immunoassay. The data indicated that these 3 HIV tests are effective testing systems for diagnosis of HIV infection in a situation when the conventional Enzyme Immunoassay is not suitable.
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Affiliation(s)
- K P Ng
- Viral Hepatitis & AIDS Laboratory, Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur
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Abstract
A total of 576 dermatophytes were isolated from patients with a variety of skin infections from January 1993 to May 2000. Ten species of dermatophytes were identified: Epidermophyton floccosum (0.7%), Microsporum audouinii (1.1%), M. canis (3.1%), M. gypseum (0.3%), Trichophyton concentricum (3.5%), T. equinum (0.2%), T. mentagrophytes (36.1%), T. rubrum (53.8%), T. verrucosum (0.2) and T. violaceum (1.0%). The body sites most frequently affected by dermatophytes were the buttocks, nails and trunk. Anthropophilic dermatophytes made up 60.1% of the isolates; the most common species was T. rubrum, T. mentagrophytes and M. canis were the two main zoophilic dermatophytes. T. mentagrophytes was isolated from all body sites except the scalp. M. canis was found to be associated with domestic dogs and was not isolated from ethnic Malays. The only geophilic dermatophyte was M. gypseum, an uncommon dermatophyte associated with tinea pedis.
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Affiliation(s)
- K P Ng
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia.
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Zeng L, Si X, Yu WP, Le HT, Ng KP, Teng RMH, Ryan K, Wang DZM, Ponniah S, Pallen CJ. PTP alpha regulates integrin-stimulated FAK autophosphorylation and cytoskeletal rearrangement in cell spreading and migration. J Cell Biol 2003; 160:137-46. [PMID: 12515828 PMCID: PMC2172736 DOI: 10.1083/jcb.200206049] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
We investigated the molecular and cellular actions of receptor protein tyrosine phosphatase (PTP) alpha in integrin signaling using immortalized fibroblasts derived from wild-type and PTP alpha-deficient mouse embryos. Defects in PTP alpha-/- migration in a wound healing assay were associated with altered cell shape and focal adhesion kinase (FAK) phosphorylation. The reduced haptotaxis to fibronectin (FN) of PTP alpha-/- cells was increased by expression of active (but not inactive) PTP alpha. Integrin-mediated formation of src-FAK and fyn-FAK complexes was reduced or abolished in PTP alpha-/- cells on FN, concomitant with markedly reduced phosphorylation of FAK at Tyr397. Reintroduction of active (but not inactive) PTP alpha restored FAK Tyr-397 phosphorylation. FN-induced cytoskeletal rearrangement was retarded in PTP alpha-/- cells, with delayed filamentous actin stress fiber assembly and focal adhesion formation. This mimicked the effects of treating wild-type fibroblasts with the src family protein tyrosine kinase (Src-PTK) inhibitor PP2. These results, together with the reduced src/fyn tyrosine kinase activity in PTP alpha-/- fibroblasts (Ponniah et al., 1999; Su et al., 1999), suggest that PTP alpha functions in integrin signaling and cell migration as an Src-PTK activator. Our paper establishes that PTP alpha is required for early integrin-proximal events, acting upstream of FAK to affect the timely and efficient phosphorylation of FAK Tyr-397.
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Affiliation(s)
- Li Zeng
- Cell Regulation Laboratory, Institute of Molecular and Cell Biology, Singapore 117609, Singapore
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