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Ali U, Zainal M, Zainol Z, Tai CW, Tang SF, Lee PC, Wong KK. Performance evaluation of two multiplex qualitative RT-PCR assays for detection of respiratory infection in paediatric population. Malays J Pathol 2023; 45:215-227. [PMID: 37658531] [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: 09/03/2023]
Abstract
INTRODUCTION Acute respiratory infection (ARI) contributes to significant mortality and morbidity worldwide and is usually caused by a wide range of respiratory pathogens. This study aims to describe the performance of QIAstat-Dx® Respiratory Panel V2 (RP) and RespiFinder® 2SMART assays for respiratory pathogens detection. MATERIALS AND METHODS A total of 110 nasopharyngeal swabs (NPS) were collected from children aged one month to 12 years old who were admitted with ARI in UKMMC during a one-year period. The two qPCR assays were conducted in parallel. RESULTS Ninety-seven samples (88.2%) were positive by QIAstat-Dx RP and 86 (78.2%) by RespiFinder assay. The overall agreement on both assays was substantial (kappa value: 0.769) with excellent concordance rate of 96.95%. Using both assays, hRV/EV, INF A/H1N1 and RSV were the most common pathogens detected. Influenza A/H1N1 infection was significantly seen higher in older children (age group > 60 months old) (53.3%, p-value < 0.05). Meanwhile, RSV and hRV/EV infection were seen among below one-year-old children. Co-infections by two to four pathogens were detected in 17 (17.5%) samples by QIAstat-Dx RP and 12 (14%) samples by RespiFinder, mainly involving hRV/EV. Bacterial detection was observed only in 5 (4.5%) and 6 (5.4%) samples by QIAstat-Dx RP and RespiFinder, respectively, with Mycoplasma pneumoniae the most common detected. CONCLUSION The overall performance of the two qPCR assays was comparable and showed excellent agreement. Both detected various clinically important respiratory pathogens in a single test with simultaneous multiple infection detection. The use of qPCR as a routine diagnostic test can improve diagnosis and management.
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Affiliation(s)
- U Ali
- Universiti Kebangsaan Malaysia, Department of Medical Microbiology and Immunology, Kuala Lumpur, Malaysia
| | - M Zainal
- Universiti Kebangsaan Malaysia, Department of Medical Microbiology and Immunology, Kuala Lumpur, Malaysia.
| | - Z Zainol
- Universiti Kebangsaan Malaysia, Department of Medical Microbiology and Immunology, Kuala Lumpur, Malaysia
| | - C W Tai
- Universiti Kebangsaan Malaysia, Department of Paediatric, Kuala Lumpur, Malaysia
| | - S F Tang
- Universiti Kebangsaan Malaysia, Department of Paediatric, Kuala Lumpur, Malaysia
| | - P C Lee
- Universiti Kebangsaan Malaysia, Department of Paediatric, Kuala Lumpur, Malaysia
| | - K K Wong
- Universiti Kebangsaan Malaysia, Department of Medical Microbiology and Immunology, Kuala Lumpur, Malaysia
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Haron FN, Azazi A, Chua KH, Lim YAL, Lee PC, Chew CH. In silico structural modeling and quality assessment of Plasmodium knowlesi apical membrane antigen 1 using comparative protein models. Trop Biomed 2022; 39:394-401. [PMID: 36214436 DOI: 10.47665/tb.39.3.009] [Citation(s) in RCA: 1] [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] [Indexed: 06/16/2023]
Abstract
Plasmodium knowlesi is the most common zoonotic parasite associated with human malaria infection in Malaysia. Apical membrane antigen 1 (AMA1) protein in the parasite plays a critical role in parasite invasion into host cells. To date, there is no complete three-dimensional ectodomain structure of P. knowlesi AMA1 (PkAMA1) protein. The knowledge of a protein structure is important to understand the protein molecular functions. Three in silico servers with respective structure prediction methods were used in this study, i.e., SWISS-MODEL for homology modeling and Phyre2 for protein threading, which are template-based modeling, while I-TASSER for template-free ab initio modeling. Two query sequences were used in the study, i.e., native ectodomain of PkAMA1 strain H protein designated as PkAMA1-H and a modified PkAMA1 (mPkAMA1) protein sequence in adaptation for Pichia pastoris expression. The quality of each model was assessed by ProSA-web, QMEAN and SAVES v6.0 (ERRAT, Verify3D and Ramachandran plot) servers. Generated models were then superimposed with two models of Plasmodium AMA1 deposited in Protein Data Bank (PDB), i.e., PkAMA1 (4UV6.B) and Plasmodium vivax AMA1 (PvAMA1, 1W81) protein structures for similarity assessment, quantified by root-meansquare deviation (RMSD) value. SWISS-MODEL, Phyre2 and I-TASSER server generated two, one and five models, respectively. All models are of good quality according to ProSA-web assessment. Based on the average values of model quality assessment and superimposition, the models that recorded highest values for most parameters were selected as best predicted models, i.e., model 2 for both PkAMA1-H and mPkAMA1 from SWISS-MODEL as well as model 1 of PkAMA1-H and model 3 of mPkAMA1 from I-TASSER. Template-based method is useful if known template is available, but template-free method is more suitable if there is no known available template. Generated models can be used as guidance in further protein study that requires protein structural data, i.e., protein-protein interaction study.
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Affiliation(s)
- F N Haron
- Faculty of Health Sciences, Universiti Sultan Zainal Abidin, 21300 Kuala Nerus, Terengganu, Malaysia
| | - A Azazi
- Faculty of Health Sciences, Universiti Sultan Zainal Abidin, 21300 Kuala Nerus, Terengganu, Malaysia
| | - K H Chua
- Department of Biomedical Science, Faculty of Medicine, Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| | - Y A L Lim
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| | - P C Lee
- Faculty of Science and Natural Resources, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia
- Biotechnology Research Institute, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia
| | - C H Chew
- Faculty of Health Sciences, Universiti Sultan Zainal Abidin, 21300 Kuala Nerus, Terengganu, Malaysia
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3
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Azazi A, Haron FN, Chua KH, Lim YAL, Lee PC, Chew CH. Bioinformatics characterization of Plasmodium knowlesi apical membrane antigen 1 (PkAMA1) for multi-epitope vaccine design. Trop Biomed 2021; 38:265-275. [PMID: 34362869 DOI: 10.47665/tb.38.3.067] [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] [Indexed: 11/21/2022]
Abstract
Malaria caused by Plasmodium knowlesi species has become a public health concern, especially in Malaysia. Plasmodium knowlesi parasite which originates from the macaque species, infects human through the bite of the Anopheles mosquitoes. Research on malaria vaccine has been a continuous effort to eradicate the malaria infection, yet there is no vaccine against P. knowlesi malaria to date. Apical membrane antigen 1 (AMA1) is a unique surface protein of all apicomplexan parasites that plays a crucial role in parasite-host cell invasion and thus has been a long-standing malaria vaccine candidate. The selection of protective epitopes in silico has led to significant advances in the design of the vaccine. The present study aimed to employ bioinformatics tools to predict the potential immunogenic B- and T-cell epitopes in designing malaria vaccine targeting P. knowlesi AMA1 (PkAMA1). B-cell epitopes were predicted using four bioinformatics tools, i.e., BepiPred, ABCpred, BcePred, and IEDB servers whereas T-cell epitopes were predicted using two bioinformatics servers, i.e., NetMHCpan4.1 and NetMHCIIpan-4.0 targeting human major histocompatibility complex (MHC) class I and class II molecules, respectively. The antigenicity of the selected epitopes computed by both B- and T-cell predictors were further analyzed using the VaxiJen server. The results demonstrated that PkAMA1 protein encompasses multi antigenic regions that have the potential for the development of multi-epitope vaccine. Two B- and T-cell epitopes consensus regions, i.e., NSGIRIDLGEDAEVGNSKYRIPAGKCP (codons 28-54) and KTHAASFVIAEDQNTSY RHPAVYDEKNKT (codons 122-150) at domain I (DI) of PkAMA1 were reported. Advancement of bioinformatics in characterization of the target protein may facilitate vaccine development especially in vaccine design which is costly and cumbersome process. Thus, comprehensive B-cell and T-cell epitope prediction of PkAMA1 offers a promising pipeline for the development and design of multi-epitope vaccine against P. knowlesi.
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Affiliation(s)
- A Azazi
- Faculty of Health Sciences, Universiti Sultan Zainal Abidin, 21300 Kuala Nerus, Terengganu, Malaysia
| | - F N Haron
- Faculty of Health Sciences, Universiti Sultan Zainal Abidin, 21300 Kuala Nerus, Terengganu, Malaysia
| | - K H Chua
- Department of Biomedical Science, Faculty of Medicine, Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| | - Y A L Lim
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, 50603 Kuala Lumpur, Malaysia.,Centre of Excellence for Research in AIDS (CERiA), Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| | - P C Lee
- Faculty of Science and Natural Resources, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia
| | - C H Chew
- Faculty of Health Sciences, Universiti Sultan Zainal Abidin, 21300 Kuala Nerus, Terengganu, Malaysia
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Md. Shahin AN, Shaayegan V, Lee PC, Park CB. In Situ Visualization for Control of Nano-Fibrillation Based on Spunbond Processing Using a Polypropylene/Polyethylene Terephthalate System. INT POLYM PROC 2021. [DOI: 10.1515/ipp-2020-4072] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
In situ generation of polyethylene terephthalate (PET) nanofibrils in polypropylene (PP) microfibers via fiber spinning in a spunbond process was studied in this work. The effects of polymer flow rate and air speed in the drafter on the formation of PET fibrils were investigated using a pilot scale machine. An in-situ visualization technique was applied to examine the fiber evolution events and stretch profile at die exit. A scanning electron microscope was used to analyze and investigate the morphology of the dispersed domain. The PET dispersed phase was fibrillated within the PP matrix such that a nonofibrillated composite containing fibrils with an average size around 100 nm was obtained. It was found that the final fibril size directly depends on the degree of die swell, the air speed and the polymer flow rate. It was also found that the in situ observed size of the micro-scale PP/PET fibers was well correlated to the size of the nano-scale PET fibers formed in the PP matrix. The visualization results revealed that a smaller fibril diameter was obtainable by increasing the stretching on the spin line and/or decreasing the die swell.
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Affiliation(s)
- A. N. Md. Shahin
- Microcellular Plastics Manufacturing Laboratory, Department of Mechanical and Industrial Engineering, University of Toronto , Toronto , Canada
| | - V. Shaayegan
- Microcellular Plastics Manufacturing Laboratory, Department of Mechanical and Industrial Engineering, University of Toronto , Toronto , Canada
| | - P. C. Lee
- Microcellular Plastics Manufacturing Laboratory, Department of Mechanical and Industrial Engineering, University of Toronto , Toronto , Canada
- Multifunctional Composites Manufacturing Laboratory, Department of Mechanical and Industrial Engineering, University of Toronto , Toronto , Canada
| | - C. B. Park
- Microcellular Plastics Manufacturing Laboratory, Department of Mechanical and Industrial Engineering, University of Toronto , Toronto , Canada
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Mahmud F, Lee PC, Abdul Wahab H, Mustaffa KMF, Leow CH, Azhar R, Lai NS. Plasmodium falciparum protein kinase as a potential therapeutic target for antimalarial drugs development. Trop Biomed 2020; 37:822-841. [PMID: 33612795 DOI: 10.47665/tb.37.3.822] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Malaria is one of the most dangerous infectious diseases due to its high infection and mortality rates, especially in the tropical belt. Plasmodium falciparum (P. falciparum), the most virulent malaria parasite in humans, was recently reported to develop resistance against the final efficient antimalarial drug, artemisinin. Little is known about the resistance mechanisms, which further complicates the problem as a proper counteraction is unable to be taken. Hence, the understanding of drug mode of action and its molecular target is valuable knowledge that needs to be considered to develop the next generation of antimalarial drugs. P. falciparum protein kinase (Pf PK) is an attractive target for antimalarial chemotherapy due to its vital roles in all P. falciparum life stages. Moreover, overall structural differences and the presence of unique Pf PKs that are absent in human kinome, suggesting specific inhibition of Pf PK without affecting human cells is achievable. To date, at least 86 eukaryotic protein kinases have been identified in P. falciparum kinome, by which less than 40 were validated as potential targets at the erythrocytes stage. In this review, recent progress of the furthest validated Pf PKs; Pf Nek-1, Pf CDPK1, Pf CDPK4, Pf PKG, and Pf CLK-3 will be briefly discussed.
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Affiliation(s)
- F Mahmud
- Institute for Research in Molecular Medicine, Universiti Sains Malaysia.,Faculty of Science and Natural Resources, Universiti Malaysia Sabah
| | - P C Lee
- Faculty of Science and Natural Resources, Universiti Malaysia Sabah
| | - H Abdul Wahab
- School of Pharmaceutical Science, Universiti Sains Malaysia
| | - K M F Mustaffa
- Institute for Research in Molecular Medicine, Universiti Sains Malaysia
| | - C H Leow
- Institute for Research in Molecular Medicine, Universiti Sains Malaysia
| | - R Azhar
- Department of Zoology, Government College University Faisalabad, Pakistan
| | - N S Lai
- Institute for Research in Molecular Medicine, Universiti Sains Malaysia
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Goh XT, Chua KH, Vythilingam I, Lee PC, Tan TC, Yap NJ, Chai HC, Nissapatorn V, Lim YAL. Genetic diversity of Merozoite Surface Protein-1 gene block 2 allelic types in Plasmodium falciparum isolates from Malaysia and Thailand. Trop Biomed 2019; 36:70-80. [PMID: 33597428] [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
Malaria is the most common vector-borne parasitic disease in Malaysia and Thailand, especially in Malayan Borneo and along the Thailand border areas, but little is known about the genetic diversity of the parasite. Present study aims to investigate the genetic diversity of Plasmodium falciparum isolates in these two countries and eventually contributes to more effective malaria control strategies, particularly in vaccine and antimalarial treatment. One hundred and seventy three P. falciparum isolates were collected from Malaysia (n = 67) and Thailand (n = 106) and genotyped using nested PCR targeting the polymorphic region of MSP-1, block 2. Sequence analysis was conducted to investigate the allele diversity of the isolates. Three allelic families were identified in Malaysian and Thailand P. falciparum isolates, MAD20, K1 and RO33. Sequence analysis revealed that there were 5 different MAD20, 1 K1 and 2 different RO33 for Malaysian isolates. Thailand isolates exhibited greater polymorphism because there were 13 different MAD20, 6 different K1 and 2 different RO33 identified in this study. Multiclonal infections were observed for the isolates in both countries, however, low multiplicity of infection (MOI) was observed for Malaysian (1.1) and Thailand (1.2) isolates. Phylogenetic analysis showed that P. falciparum isolates of Malaysia and Thailand were clustered in the same group for all the allelic families. Population structure of P. falciparum isolates in Malaysia and Thailand exhibit extensive genetic polymorphism but showed high similarities as well as comparable MOI.
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Affiliation(s)
- X T Goh
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - K H Chua
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - I Vythilingam
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - P C Lee
- Faculty of Natural Resources, University Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia
| | - T C Tan
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - N J Yap
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - H C Chai
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - V Nissapatorn
- Research Excellence Center for Innovation and Health Products (RECIHP) and School of Allied Health Sciences, Walailak University, Nakhon Si Thammarat, Thailand
| | - Y A L Lim
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
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7
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Lee PC, Ganguly S, Goh SY. Weight loss associated with sodium-glucose cotransporter-2 inhibition: a review of evidence and underlying mechanisms. Obes Rev 2018; 19:1630-1641. [PMID: 30253050 DOI: 10.1111/obr.12755] [Citation(s) in RCA: 114] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 07/13/2018] [Accepted: 07/16/2018] [Indexed: 02/07/2023]
Abstract
With their novel, insulin-independent mechanism, sodium-glucose cotransporter-2 (SGLT2) inhibitors are a major turning point in the management of type 2 diabetes mellitus. At present, there are several SGLT2 inhibitors available or in development, and these oral anti-hyperglycaemic agents lower plasma glucose through the inhibition of SGLT2-mediated reuptake of filtered glucose in the kidney. This unique mechanism of action is also expected to result in other beneficial effects, such as weight loss and blood pressure reduction. In various studies, including randomized controlled trials and real-world studies, patients treated with SGLT2 inhibitors have reported weight loss of around 1 to 3 kg. This review describes the characteristics of weight loss associated with SGLT2 inhibitor therapy, the clinical factors affecting SGLT2 inhibitor-associated weight loss and the possible underlying mechanisms of SGLT2 inhibitor-associated weight loss, including changes in metabolism and body composition, and the role of a reduction in insulin dose and compensatory hyperphagia. Understanding the weight loss effect of SGLT2 inhibitors, its related factors and underlying mechanisms can aid clinicians in optimal treatment decision-making, provide valuable insight on both obesity and diabetes management and reveal areas of future research and new therapeutic options.
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Affiliation(s)
- P C Lee
- Department of Endocrinology, Singapore General Hospital, Singapore.,Duke-NUS Medical School, Singapore
| | - S Ganguly
- Department of Endocrinology, Singapore General Hospital, Singapore.,Duke-NUS Medical School, Singapore
| | - S-Y Goh
- Department of Endocrinology, Singapore General Hospital, Singapore.,Duke-NUS Medical School, Singapore
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Teoh CP, Wong CMVL, Lee DJH, González MA, Najimudin N, Lee PC, Cheah YK. Genome Sequences of Two Cold-Adapted <i>Cryobacterium</i> Spp. SO1 and SO2 from Fildes Peninsula, Antarctica. CURR SCI INDIA 2018. [DOI: 10.18520/cs/v115/i9/1706-1708] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Lee PC, Ching WM, Kam CW, Yau HH. A Case Series of Candle Wax Burns during the Lantern Festival in Hong Kong. HONG KONG J EMERG ME 2017. [DOI: 10.1177/102490790200900408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Every year there was significant number of burn cases during the Lantern (Mid-Autumn) Festival in Hong Kong because children liked to play with fire on that day. They would either burn the lantern or boil the wax from candles in a pot over a fire. When the wax has melted, they poured cold water into it, causing a small explosion with water vapour and wax droplets. Children and adolescents were more common than adults to be burnt by the hot vapour, fire or hot wax. The majority sustained partial thickness burns involving the face. Such burn injuries should be preventable by education and legislation.
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Yao SX, Lee PC. A new gas/supercritical fluid (SCF) diffusivity measurement method for CO2 saturated polymer systems using a dielectric property. EXPRESS POLYM LETT 2017. [DOI: 10.3144/expresspolymlett.2017.64] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Suhaini S, Liew SZ, Norhaniza J, Lee PC, Jualang G, Embi N, Hasidah MS. Anti-malarial and anti-inflammatory effects of Gleichenia truncata mediated through inhibition of GSK3β. Trop Biomed 2015; 32:419-433. [PMID: 26695202] [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: 06/05/2023]
Abstract
Gleichenia truncata is a highland fern from the Gleicheniaceae family known for its traditional use among indigenous communities in Asia to treat fever. The scientific basis of its effect has yet to be documented. A yeast-based kinase assay conducted in our laboratory revealed that crude methanolic extract (CME) of G. truncata exhibited glycogen synthase kinase-3 (GSK3)-inhibitory activity. GSK3β is now recognized to have a pivotal role in the regulation of inflammatory response during bacterial infections. We have also previously shown that lithium chloride (LiCl), a GSK3 inhibitor suppressed development of Plasmodium berghei in a murine model of malarial infection. The present study is aimed at evaluating G. truncata for its anti-malarial and anti-inflammatory effects using in vivo malarial and melioidosis infection models respectively. In a four-day suppressive test, intraperitoneal injections of up to 250 mg/kg body weight (bw) G. truncata CME into P.berghei-infected mice suppressed parasitaemia development by >60%. Intraperitoneal administration of 150 mg/kg bw G. truncata CME into Burkholderia pseudomallei-infected mice improved survivability by 44%. G. truncata CME lowered levels of pro-inflammatory cytokines (TNF-α, IFN-γ) in serum and organs of B. pseudomallei-infected mice. In both infections, increased phosphorylations (Ser9) of GSK3β were detected in organ samples of animals administered with G. truncata CME compared to controls. Taken together, results from this study strongly suggest that the anti-malarial and anti-inflammatory effects elicited by G. truncata in part were mediated through inhibition of GSK3β. The findings provide scientific basis for the ethnomedicinal use of this fern to treat inflammation-associated symptoms.
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Affiliation(s)
- S Suhaini
- School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM, Bangi, Selangor, Malaysia
| | - S Z Liew
- School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM, Bangi, Selangor, Malaysia
| | - J Norhaniza
- Faculty of Science and Natural Resources, Universiti Malaysia Sabah, 88400 Kota Kinabalu, Sabah, Malaysia
| | - P C Lee
- Faculty of Science and Natural Resources, Universiti Malaysia Sabah, 88400 Kota Kinabalu, Sabah, Malaysia
| | - G Jualang
- Faculty of Science and Natural Resources, Universiti Malaysia Sabah, 88400 Kota Kinabalu, Sabah, Malaysia
| | - N Embi
- School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM, Bangi, Selangor, Malaysia
| | - M S Hasidah
- School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM, Bangi, Selangor, Malaysia
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Lee PC, Dietsche L, Dooley J, Parashar S. Improving Film Die Flow Uniformity Using Optimization Methods Coupled with Finite Element Computational Fluid Dynamics (CFD) Analysis. INT POLYM PROC 2015. [DOI: 10.3139/217.2887] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
The aim of this study was to evaluate various optimization strategies to be used with computational fluid dynamics (CFD), in order to optimize the geometry for a polymer die to meet the dual objectives of uniform flow at the exit with minimal pressure drop. 3D finite element simulations using the numerically optimized geometry predict a more uniform flow than simulations using the baseline geometry. However, some of the initial optimized results yielded die geometries that would be impractical to fabricate. Additional constraints were placed on the allowable geometric parameters and solution space to push the optimization towards more feasible optimal solutions. Thus we have shown how CFD-based optimization methods, coupled with knowledge of die design technology and fabrication techniques can lead to the design of better performing polymer dies.
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Affiliation(s)
- P. C. Lee
- School of Engineering , University of Vermont, Burlington, VT , USA
| | - L. Dietsche
- The Dow Chemical Company , Midland, MI , USA
| | - J. Dooley
- The Dow Chemical Company , Midland, MI , USA
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Lee PC, Bordelon Y, Bronstein J, Sinsheimer JS, Farrer M, Ritz B. Head injury, α-synuclein genetic variability and Parkinson's disease. Eur J Neurol 2014; 22:874-8. [PMID: 25370538 DOI: 10.1111/ene.12585] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [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: 04/13/2014] [Accepted: 08/29/2014] [Indexed: 11/26/2022]
Abstract
BACKGROUND AND PURPOSE Head injury has been linked to Parkinson's disease (PD) in some but not all studies. Differences in the genetic and environmental susceptibility to PD between populations might be one explanation. The joint effects of head injuries and SNCA genetic variants were investigated. METHODS From 2001 to 2012, 561 incident idiopathic PD cases and 721 population controls from central California were enrolled. Subjects reported on head injuries throughout their lifetime and were assessed for genetic variability in the SNCA 5' region (D4S3481; Rep1) and 3' untranslated region (rs356165). In unconditional logistic regression models adjusted for confounders, interactions between head injuries and genetic risk variants were investigated. RESULTS Parkinson's disease risk in individuals with head injury who are carriers of at least one 263 bp allele in D4S3481 or rs356165 variants was 3-4.5-fold higher compared with non-carriers without head injuries. However, tests for interaction between head injury and SNCA D4S3481or rs356165 were not statistically significant. CONCLUSIONS Our study finds some evidence that head injury and D4S3481 or rs356165 variants jointly increase the risk of PD but little evidence of interaction.
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Affiliation(s)
- P C Lee
- Department of Health Care Management, College of Healthcare Administration and Management, National Taipei University of Nursing and Health Sciences, Taipei, Taiwan
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Lau TP, Roslani AC, Lian LH, Lee PC, Hilmi I, Goh KL, Chua KH. Association between EGF and VEGF functional polymorphisms and sporadic colorectal cancer in the Malaysian population. Genet Mol Res 2014; 13:5555-61. [PMID: 25117311 DOI: 10.4238/2014.july.25.9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Growth factors are polypeptides that are critical for the initiation, progression, and metastasis of cancer. Most tumor cells are capable of synthesizing particular growth factors leading to constitutive pathway activation in these cells through autocrine signaling. Epidermal growth factor (EGF) is a potent mitogenic peptide that exerts direct effects on the proliferation and differentiation of tumor cells in carcinogenesis. By contrast, vascular endothelial growth factor (VEGF) is vital for the invasion and metastasis of neoplasms through the formation of new blood vessels from mature endothelial cells. In this study, we investigated the association between functional polymorphisms of both the EGF and VEGF genes and colorectal cancer (CRC) susceptibility. A total of 130 CRC patients and 212 healthy controls were recruited for this case-control study. Genotyping of genetic variants was conducted via real-time polymerase chain reaction (PCR) amplification with allele-specific TaqMan probes. None of the genotypes of the EGF +61 A>G and VEGF +936 C>T variants was significantly associated with CRC susceptibility among the Malaysian subjects evaluated (P > 0.05). The observed frequency distributions of the EGF +61 A>G polymorphism genotypes showed ethnic heterogeneity, which was not the case for the VEGF +936 C>T genotypes. In conclusion, no positive correlation between these functional polymorphisms and CRC risk was found in this Malaysian population. Studies of the EGF and VEGF genes and CRC susceptibility are scarce, and the results reported thus far differ from one population to another. Hence, more replication studies are warranted before any firm conclusions can be made.
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Affiliation(s)
- T P Lau
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - A C Roslani
- Division of General Surgery, Department of Surgery, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - L H Lian
- Casa Vista, Jalan Penaga, Kuala Lumpur, Malaysia
| | - P C Lee
- School of Science and Technology, Universiti Sabah Malaysia, Kota Kinabalu, Sabah, Malaysia
| | - I Hilmi
- Division of Gastroenterology and Hepatology, Department of Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - K L Goh
- Division of Gastroenterology and Hepatology, Department of Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - K H Chua
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
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Abstract
Mutations in the PAX6 gene that cause aniridia have been identified in various ethnicities but not in the Malaysian population. Therefore, the objective of this study was to investigate the PAX6 mutation in a Malaysian family with congenital aniridia. In this study, a complete ophthalmic examination was performed on a Dusun ethnic family with aniridia. Genomic DNA was extracted from the peripheral blood of the subjects and screened for the PAX6 gene mutation using polymerase chain reaction amplification high-resolution melting curve analysis (PCR-HRM) followed by confirmation via direct DNA sequencing. A heterozygous G deletion (c.857delG) in exon 7 causing a frame shift in PAX6 was identified in all affected family members. Genotype-phenotype correlation analysis revealed congenital cataract and all affected family members showed a similar spectrum of aniridia with no phenotypic variability but with differences in severity that were age-dependent. In summary, by using a PCR-HRM approach, this study is the first to report a PAX6 mutation in a Malaysian family. This mutation is the cause of the aniridia spectra observed in this family and of congenital cataract.
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Affiliation(s)
- P C Lee
- School of Science and Technology, Universiti Malaysia Sabah, Jalan UMS, Kota Kinabalu, Sabah, Malaysia
| | - H H Lam
- Department of Ophthalmology, Queen Elizabeth Hospital, Kota Kinabalu, Sabah, Malaysia
| | - S A Ghani
- Department of Ophthalmology, Queen Elizabeth Hospital, Kota Kinabalu, Sabah, Malaysia
| | - V Subrayan
- Department of Ophthalmology, University of Malaya Medical Center, Kuala Lumpur, Malaysia
| | - K H Chua
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
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Lau TP, Roslani AC, Lian LH, Lee PC, Hilmi I, Goh KL, Chua KH. NOD2/CARD15 variants in Malaysian patients with sporadic colorectal cancer. Genet Mol Res 2014; 13:7079-85. [PMID: 24682985 DOI: 10.4238/2014.march.19.3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Colorectal cancer (CRC) is one of the most common types of cancer in both developed and developing countries. This disease is triggered by and progresses via the sequential accumulation of multiple genetic alterations. In addition, the interaction between low-penetrance genes and environmental factors can also increase the risk of developing CRC. Since inflammatory bowel diseases (IBDs) are one of the predisposing factors for CRC, IBD-related genes might, to a certain extent, be associated with cancer initiation. The nucleotide oligomerization domain 2/caspase activating recruitment domain 15 gene (NOD2/CARD15) is the most well-established gene to be associated with increased susceptibility to Crohn's disease. Thus, various studies have been performed to investigate the potential contribution of this gene to CRC risk. In this study, we aimed to determine the frequency of the Arg702Trp, Gly908Arg, 3020insC, Pro268Ser, and JW1 variants of NOD2/CARD15, and to investigate their association with CRC susceptibility. A total of 130 CRC patients and 212 healthy controls were recruited for this study. Subsequently, real-time polymerase chain reaction with TaqMan was performed for the genotyping of these NOD2/ CARD15 variants. None of the NOD2/CARD15 variants was statistically associated to CRC susceptibility in our Malaysian population. Our findings were remarkably similar to those of other Asian cohorts, which indicated that these NOD2/CARD15 variants exhibit genetic heterogeneity between Caucasian and Asian populations.
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Affiliation(s)
- T P Lau
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - A C Roslani
- Division of General Surgery, Department of Surgery, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - L H Lian
- Casa Vista, Jalan Penaga, Kuala Lumpur, Malaysia
| | - P C Lee
- School of Science and Technology, Universiti Sabah Malaysia, Kota Kinabalu, Sabah, Malaysia
| | - I Hilmi
- Division of Gastroenterology and Hepatology, Department of Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - K L Goh
- Division of Gastroenterology and Hepatology, Department of Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - K H Chua
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
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Stiles BM, Nasar A, Mirza F, Port JL, Lee PC, Paul S, Altorki NK. Quality of lymphadenectomy for esophageal cancer in the United States: An analysis of the SEER database. J Clin Oncol 2011. [DOI: 10.1200/jco.2011.29.15_suppl.4068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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20
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Abstract
Allele frequencies of 15 short tandem repeat (STR) loci, namely D5S818, D7S820, D13S317, D16S539, TH01, TPOX, Penta D, Penta E, D3S1358, D8S1179, D18S51, D21S11, CSF1PO, vWA, and FGA, were determined for 154 individuals from the Kadazan-Dusun tribe, an indigenous population of East Malaysia. All loci were amplified by polymerase chain reaction, using the Powerplex 16 system. Alleles were typed using a gene analyzer and the Genemapper ID software. Various statistical parameters were calculated and the combined power of discrimination for the 15 loci in the population was calculated as 0.999999999999999. These loci are thus, informative and can be used effectively in forensic and genetic studies of this indigenous population.
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Affiliation(s)
- B P Kee
- Department of Molecular Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
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Port JL, Yankelevitz D, Lee PC, Spinelli C, Altorki NK. Preoperative erlotinib in clinical stage I and II non-small cell lung cancer. J Clin Oncol 2010. [DOI: 10.1200/jco.2010.28.15_suppl.e13639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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22
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Stiles BM, Mirza F, Chiu Y, Port JL, Lee PC, Paul S, Altorki NK. Evaluation of neoadjuvant “window of opportunity” trials with targeted therapy in patients with surgically resectable non-small cell lung cancer. J Clin Oncol 2010. [DOI: 10.1200/jco.2010.28.15_suppl.7060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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23
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Rubinstein E, Barriere SL, Genter FC, Corey GR, Lee PC, Lalani T. Late ventilator-associated pneumonia: analysis of baseline characteristics and clinical outcomes in the ATTAIN studies. Crit Care 2010. [PMCID: PMC2934041 DOI: 10.1186/cc8312] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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24
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Lee PC, Lee CY, Hu RH, Lo C, Tsai MK, Lee PH. Intrarenal vascular resistance parameters in kidney transplant patients receiving calcineurin inhibitor-based or sirolimus-based regimens. Nephrol Dial Transplant 2009; 25:1675-80. [DOI: 10.1093/ndt/gfp716] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
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Gulkarov I, Paul S, Altorki NK, Lee PC. Use of Amplatzer device for endobronchial closure of bronchopleural fistulas. Interact Cardiovasc Thorac Surg 2009; 9:901-2. [DOI: 10.1510/icvts.2009.215202] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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27
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Affiliation(s)
- Bethan J. Morgan
- Conservation and Research for Endangered Species (CRES), Zoological Society of San Diego, BP 3055 Messa, Yaoundé, Cameroon
| | - P. C. Lee
- University of Stirling, Stirling FK9 4LA, U.K
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Abstract
We present evidence of agonistic buffering in captive chimpanzees, recorded from 1993 until 2005, mainly from ad libitum sampling in over 2000 hr of observation. A total of 33 agonistic buffering episodes were analyzed for context and effects of this complex social behavior. Agonistic buffering was directed at the whole chimpanzee colony as they supported an individual who initially received aggression from the alpha male, independently of the victim's age, sex or social rank. Chimpanzee agonistic buffering behavior is compared with that in other nonhuman primate species, and we describe some particularities of chimpanzee agonistic buffering: the status of the buffers used-socially important offspring such as those from the alpha female-and the social rank of the adult male responsible for the buffering episode-alpha male. Possible functions for this behavior in chimpanzees are suggested as appeasement of group members in a particularly crowded captive setting, and/or as a "forced reconciliation" mechanism. Chimpanzees exhibit behavioral flexibility by adapting themselves to new social and physical situations and use novel behavior to achieve social benefits.
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Affiliation(s)
- C Casanova
- Department of Biological Anthropology, University of Cambridge, Cambridge, United Kingdom.
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29
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Affiliation(s)
- A. R. Mendes Pontes
- Departamento de Zoologia, Universidade Federal de Pernambuco, CCB, Recife, PE, Brazil
| | - D. J. Chivers
- Wildlife Research Group, Department of Anatomy, University of Cambridge, Cambridge, UK
| | - P. C. Lee
- University of Stirling, Stirling, UK
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31
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Abstract
The reproductive cycles of 23 captive olive baboons were studied over two successive parturitions. Interbirth intervals of 450 days were reduced by 60% in comparison to wild baboons, and consisted of 145 days of postpartum amenorrhea, 3.5 cycles, and a gestation of 185 days. Dominance rank was found to be one significant factor affecting female fertility. Low-ranking females had longer total intervals between successive births and, in particular, they experienced a longer delay to conception once they had resumed sexual cycles. Mothers of infants who were heavy for age resumed cycling more quickly and had fewer cycles before a subsequent conception. Mothers best able to sustain rapid early infant growth were those of high dominance rank and of high body mass; these females had more rapid reproductive rates. As female energy intake was unrelated to dominance, we suggest that social stresses are important suppressors of the hormonal and lactational competence of subordinate females.
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Affiliation(s)
- C Garcia
- Laboratoire de Dynamique de l'Evolution Humaine, CNRS UPR 2147, 75014 Paris, France
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33
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Abstract
Wild capuchin monkeys inhabiting dry forest were found to customarily use tools as part of their extractive foraging techniques. Tools consisted of twigs and sticks, often modified, which were used to probe for insects and, most frequently, of stones of a variety of sizes and shapes used for cracking and digging. The use of tools for digging has been thought to be restricted to humans. These monkeys, living in a harsh dry habitat, survive food limitation and foraging time constraints through their extensive tool use.
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Affiliation(s)
- A C de A Moura
- Darwin College, University of Cambridge, Silver Street, Cambridge CB3 9EU, UK.
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Abstract
BACKGROUND Starch digestion is dependent on a combination of pancreatic and salivary amylase and the intestinal brush border enzymes glucoamylase and sucrase-isomaltase. Glucoamylase splits successive glucose molecules from the nonreducing end of starch molecules and is particularly important in infants who are relatively deficient in pancreatic amylase. METHODS The authors measured glucoamylase activity in endoscopic mucosal biopsies submitted for measurement of disaccharidase activity from 214 patients aged 1 month to 20 years. Glucoamylase activity was measured using glucose polymers (polycose) as the substrate. The authors also related enzyme activity to histologic appearance and clinical indication for endoscopy. RESULTS The most common reasons for biopsy were abdominal pain, gastroesophageal reflux, and vomiting. Disaccharidase activity by age was similar to previous reports. Glucoamylase activity did not differ with age, but was 2 to 3 times the activity reported previously. Glucoamylase activity was significantly depressed in children with the most severe histologic abnormalities. Normal glucoamylase activity (+/-2 SD) was 80.6 +/- 54.8 micromoles of glucose produced per minute per gram of protein. CONCLUSIONS Glucoamylase activity is 2 to 3 times higher when glucose polymers are used as substrate than when glycogen is used. Severe mucosal disease is associated with reduced glucoamylase activity. Quantitation of glucoamylase activity with glucose polymers is more appropriate in evaluating children since these polymers are commonly used as carbohydrate source in the diet.
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Affiliation(s)
- P C Lee
- Department of Pediatrics, Division of Gastroenterology, The Medical College of Wisconsin, Milwaukee 53226, USA
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Garcia C, Rosetta L, Ancel A, Lee PC, Caloin M. Kinetics of stable isotope and body composition in olive baboons (Papio anubis) estimated by deuterium dilution space: a pilot study. J Med Primatol 2004; 33:146-51. [PMID: 15102071 DOI: 10.1111/j.1600-0684.2004.00064.x] [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] [Indexed: 11/28/2022]
Abstract
Morphometrics and isotope-labelled water were used to determine body composition [total body water, total body fat and fat-free mass (FFM)] of three captive female olive baboons (Papio anubis). Mean mass was 16.5 kg, comparable with other captive settings but heavier than wild olive baboons. Average water content was 66%; FFM averaged 90.5%. Baboon females have less body fat than human counterparts. Compared with captive or wild baboons, these females were adequately nourished for their energy expenditure. A positive association between total mass and FFM existed, but due to the small sample no general relationship was observed for body fat or FFM and condition or size measures. The kinetics of deuterium equilibration in body fluids for baboons was determined as 3-4 hours after injection, similar to that for humans. Deuterium dilution technique appears to be an appropriate method for studying body composition in baboons, although a larger sample is needed for relationships between morphometric indices and body composition.
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Affiliation(s)
- C Garcia
- Laboratoire de dynamique de l'évolution humaine, Paris, France
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36
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Huo TI, Huang YH, Wu JC, Lee PC, Chang FY, Lee SD. Persistent retention of acetic acid is associated with complete tumour necrosis in patients with hepatocellular carcinoma undergoing percutaneous acetic acid injection. Scand J Gastroenterol 2004; 39:168-73. [PMID: 15000280 DOI: 10.1080/00365520310008269] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Ultrasound (US)-guided percutaneous acetic acid injection therapy (PAIT) is effective for patients with hepatocellular carcinoma (HCC). This study aimed to determine the occurrence and predictive value of persistent intra-tumoral retention of acetic acid after PAIT. METHODS We prospectively studied 60 (52 M, mean age 68 +/- 10 years) patients with 72 HCC nodules (45 < or = 3 cm) treated with PAIT. The presence of post-treatment persistent retention of acetic acid, defined as a homogeneous and highly hyperechoid mass in US appearance 3 days after completion of the treatment, was correlated with the treatment response. RESULTS The mean size of the treated tumour was 2.9 +/- 1.0 cm (range 1.5-5 cm). Thirty (42%) HCC nodules showed complete tumour necrosis demonstrated by contrast-enhanced dynamic CT. Complete response was found in 22 (69%) of 32 nodules showing persistent intra-tumoral retention of acetic acid (P < 0.001). Small (< or = 3 cm) tumour size was also significantly associated with complete tumour necrosis (P = 0.001). There were no significant differences of the injection volume and treatment sessions between those with and without complete tumour necrosis in either small or large (> 3 cm) HCC (P > 0.1). Multivariate logistic regression analysis showed that persistent retention of acetic acid (odds ratio (OR) 10.4, 95% confidence interval (CI) 3.1-34.7; P < 0.001) and tumour size < or = 3 cm (OR 6.8, 95%, CI 1.8-25.8; P = 0.002) were independent factors predicting complete tumour necrosis. CONCLUSIONS The presence of persistent retention of acetic acid is associated with a favourable response and may predict complete tumour necrosis after PAIT.
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Affiliation(s)
- T I Huo
- Division of Gastroenterology, Dept. of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
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Lee PC, Lee SY, Hong SH, Chang HN. Batch and continuous cultures of Mannheimia succiniciproducens MBEL55E for the production of succinic acid from whey and corn steep liquor. Bioprocess Biosyst Eng 2003; 26:63-7. [PMID: 14530958 DOI: 10.1007/s00449-003-0341-1] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.2] [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: 01/14/2003] [Accepted: 08/15/2003] [Indexed: 10/26/2022]
Abstract
Mannheimia succiniciproducens MBEL55E isolated from bovine rumen is able to produce a large amount of succinic acid in a medium containing glucose, peptone, and yeast extract. In order to reduce the cost of the medium, whey and corn steep liquor (CSL) were used as substrates for the production of succinic acid by M. succiniciproducens MBEL55E. Anaerobic batch cultures of M. succiniciproducens MBEL55E in a whey-based medium containing CSL resulted in the production of succinic acid with a yield of 71% and productivity of 1.18 g/l/h, which are similar to those obtained in a whey-based medium containing yeast extract (72% and 1.21 g/l/h). Anaerobic continuous culture of M. succiniciproducens MBEL55E in a whey-based medium containing CSL resulted in a succinic acid yield of 69% and a succinic acid productivity as high as 3.90 g/l/h. These results show that succinic acid can be produced efficiently and economically by M. succiniciproducens MBEL55E from whey and CSL.
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Affiliation(s)
- P C Lee
- Metabolic and Biomolecular Engineering National Research Laboratory, Department of Chemical & Biomolecular Engineering, Korea Advanced Institute of Science and Technology, 373-1 Guseong-dong, 305-701 Yuseong-gu, Daejeon, Republic of Korea
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Abstract
Evolution, Gender, and Rape
. Cheryl Brown Travis, Ed. MIT Press, Cambridge, MA, 2003. 460 pp. $62, £41.50. ISBN 0-262-20143-7. Paper, $24.95, £16.50. ISBN 0-262-70090-5.
The contributors critique Randy Thornhill and Craig Palmer's Natural History of Rape from a variety of perspectives, and they also discuss responses to that book in the media and academia.
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Affiliation(s)
- P. C. Lee
- The reviewer is in the Department of Biological Anthropology, University of Cambridge, Downing Street, Cambridge CB2 3DZ, UK
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Huo TI, Huang YH, Wu JC, Lee PC, Chang FY, Lee SD. Comparison of percutaneous acetic acid injection and percutaneous ethanol injection for hepatocellular carcinoma in cirrhotic patients: a prospective study. Scand J Gastroenterol 2003; 38:770-8. [PMID: 12889565 DOI: 10.1080/00365520310003048] [Citation(s) in RCA: 60] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Ultrasound-guided percutaneous ethanol injection (PEI) and percutaneous acetic acid injection (PAI) are effective in the treatment of hepatocellular carcinoma (HCC). We conducted a prospective study to compare the therapeutic efficacy of both these methods. METHODS Sixty-three patients were treated by PAI using 50% acetic acid and 62 by PEI using pure ethanol. There were no significant baseline differences in age, sex, Child-Pugh class, tumour size and number, or other clinico-biochemical parameters between the two groups. RESULTS During a follow-up period of 24 +/- 9 (range 6-38) months, 19 (30%) of the PAI group and 21 (34%) of the PEI group died (P = 0.704). The 1- and 3-year survival rates were 84% and 51% for the PAI group and 81% and 46% for the PEI group (P = 0.651). The corresponding tumour recurrence rates were 51% and 74% for the PAI group, and 54% and 64% for the PEI group (P = 0.787). The treatment sessions were 3.9 +/- 1.6 and 6.2 +/- 2.3 for the PAI and PEI groups, respectively, in each treatment cycle (P = 0.008). A multivariate analysis using the Cox regression model revealed that ascites (relative risk (RR) 3.1, 95% confidence interval (CI) 1.5-6.3, P = 0.002), large (>3 cm) or multinodular HCCs (RR 2.4, 95% CI 1.1-5.4, P = 0.04), and development of tumour recurrence (RR 7.0, 95% CI 3.1-16.0, P < 0.001) were independent, poor prognostic factors in both groups. CONCLUSIONS PAI and PEI are equally effective in the treatment of HCC. PAI has the advantage of fewer treatment sessions in each treatment course. Careful pretreatment patient selection may improve survival.
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Affiliation(s)
- T I Huo
- Division of Gastroenterology, Dept. of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, Republic of China.
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40
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Barie PS, Coppa G, Cryer HG, Fry DE, Lee PC, Martens MG, Nichols RL, O'Leary JP, Rapp RP, Sirinek KR, Smith DW, Wilson SE. Roundtable discussion of antibiotic therapy in surgical infections. Surg Infect (Larchmt) 2003; 1:79-89. [PMID: 12594913 DOI: 10.1089/109629600321335] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- P S Barie
- Cornell University Medical College and Anne and Max A. Cohen Surgical Intensive Care Unit, The New York Presbyterian Hospital-Cornell Medical Center, New York, NY 10021, USA.
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41
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Abstract
Anaerobiospirillum succiniciproducens grew on a minimal salts medium containing wood hydrolysate (equivalent to 27 g glucose l(-1)) and, when supplemented with 10 g corn steep liquor l(-1) as a complex nitrogen source, succinic acid at 24 g l(-1) was obtained (yield = 88% w/w glucose). This may therefore be an economical method to produce succinic acid.
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Affiliation(s)
- P C Lee
- Metabolic and Biomolecular Engineering National Research Laboratory, Korea Advanced Institute of Science and Technology, 373-1 Guseong-dong, Yuseong-gu, Daejeon 305-701, Republic of Korea
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Lee PC, Chen SA, Chiang CE, Tai CT, Yu WC, Hwang B. Clinical and electrophysiological characteristics in children with atrioventricular nodal reentrant tachycardia. Pediatr Cardiol 2003; 24:6-9. [PMID: 12574975 DOI: 10.1007/s00246-002-0145-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Atrioventricular (AV) nodal reentrant tachycardia is one of the most common supraventricular tachycardias in childhood. However, information about AV nodal reentrant tachycardia in childhood is limited, especially about the variant and multiple forms. The purpose of this retrospective study was to investigate the clinical and electrophysiological characteristics in pediatric patients with AV nodal reentrant tachycardia. Forty-eight pediatric patients with AV nodal reentrant tachycardia were included (ages 11-18 years; 25 males and 23 females). The age of onset and duration of symptoms were significantly younger and shorter in pediatric patients, respectively. A higher incidence of antegrade dual AV nodal pathways was found in adult patients than pediatric patients (72.9 vs 52.1% p = 0.003). Both antegrade and retrograde slow pathway functions were better in pediatric than adult patients. There was no significant difference between children and adults in the occurrence of variant and multiple forms of AV nodal reentrant tachycardia. This study demonstrated that pediatric patients have different electrophysiologic characteristics from those of adult patients.
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Affiliation(s)
- P C Lee
- Department of Pediatrics, Taipei Veterans General Hospital and National Yang-Ming University, Taipei, Taiwan
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Lee PC, Schmidt-Dannert C. Metabolic engineering towards biotechnological production of carotenoids in microorganisms. Appl Microbiol Biotechnol 2002; 60:1-11. [PMID: 12382037 DOI: 10.1007/s00253-002-1101-x] [Citation(s) in RCA: 190] [Impact Index Per Article: 8.6] [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: 05/18/2002] [Revised: 07/16/2002] [Accepted: 07/18/2002] [Indexed: 11/29/2022]
Abstract
Carotenoids are important natural pigments produced by many microorganisms and plants. Traditionally, carotenoids have been used in the feed, food and nutraceutical industries. The recent discoveries of health-related beneficial properties attributed to carotenoids have spurred great interest in the production of structurally diverse carotenoids for pharmaceutical applications. The availability of a considerable number of microbial and plant carotenoid genes that can be functionally expressed in heterologous hosts has opened ways for the production of diverse carotenoid compounds in heterologous systems. In this review, we will describe the recent progress made in metabolic engineering of non-carotenogenic microorganisms for improved carotenoid productivity. In addition, we will discuss the application of combinatorial and evolutionary strategies to carotenoid pathway engineering to broaden the diversity of carotenoid structures synthesized in recombinant hosts.
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Affiliation(s)
- P C Lee
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, 1479 Gortner Avenue, St. Paul 55108, USA
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Pham SM, Qi XS, Mallon SM, Kaplon RJ, Bauerlein EJ, Katariya K, Sequeira RF, Bolooki H, Rosenkranz E, Loo AF, Lee PC, Jimenez J, Salerno TA. Sirolimus and tacrolimus in clinical cardiac transplantation. Transplant Proc 2002; 34:1839-42. [PMID: 12176597 DOI: 10.1016/s0041-1345(02)03098-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Si M Pham
- Department of Surgery, University of Miami School of Medicine, Highland Professional Building, 5th Floor, 1801 NW 9th Avenue, Miami, FL 33136, USA
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Matheson MS, Lee PC, Meisel D, Pelizzetti E. Kinetics of hydrogen production from methyl viologen radicals on colloidal platinum. ACTA ACUST UNITED AC 2002. [DOI: 10.1021/j100226a008] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Lee PC, Lee SY, Hong SH, Chang HN. Isolation and characterization of a new succinic acid-producing bacterium, Mannheimia succiniciproducensMBEL55E, from bovine rumen. Appl Microbiol Biotechnol 2002; 58:663-8. [PMID: 11956751 DOI: 10.1007/s00253-002-0935-6] [Citation(s) in RCA: 232] [Impact Index Per Article: 10.5] [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: 10/25/2001] [Revised: 12/18/2001] [Accepted: 12/20/2001] [Indexed: 10/27/2022]
Abstract
A novel succinic acid-producing bacterium was isolated from bovine rumen. The bacterium is a non-motile, non-spore-forming, mesophilic and capnophilic gram-negative rod or coccobacillus. Phylogenetic analysis based on the 16S rRNA sequence and physiological analysis indicated that the strain belongs to the recently reclassified genus Mannheimia as a novel species, and has been named Mannheimia succiniciproducens MBEL55E. Under 100% CO(2) conditions, it grows well in the pH range of 6.0-7.5 and produces succinic acid, acetic acid and formic acid at a constant ratio of 2:1:1. When M. succiniciproducensMBEL55E was cultured anaerobically in medium containing 20 g l(-1) glucose as carbon source, 13.5 g l(-1) of succinic acid was produced.
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Affiliation(s)
- P C Lee
- Metabolic and Biomolecular Engineering National Research Laboratory, Department of Chemical Engineering and BioProcess Engineering Research Center, Korea
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Shan YS, Lee PC, Wang JR, Tsai HP, Sung CM, Jin YT. Fibrosing cholestatic hepatitis possibly related to persistent parvovirus B19 infection in a renal transplant recipient. Nephrol Dial Transplant 2001; 16:2420-2. [PMID: 11733638 DOI: 10.1093/ndt/16.12.2420] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Y S Shan
- Department of Surgery, College of Medicine, National Cheng Kung University, Tainan, Taiwan
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Abstract
BACKGROUND The relationship between celiac disease and juvenile diabetes has long been known. Only a single study in the United States, from Buffalo, New York, has reported the prevalence of celiac disease in a pediatric diabetic population. This study was conducted to determine the prevalence and clinical presentation of celiac disease in children and adolescents with juvenile diabetes in Wisconsin, USA, using serum antiendomysial antibody as a screening test. METHODS Two hundred eighteen patients with diabetes (113 males; age range, 4-21 years) and 117 age-and gender-matched control participants were tested for immunoglobulin A endomysial antibody. Patients with positive results were offered a small bowel biopsy. A questionnaire regarding abdominal pain, diarrhea, and growth failure was completed by the parents. RESULTS Seventeen of 218 diabetic patients (7.7%) had positive endomysial antibody. All control participants had negative results for the endomysial antibody. Small bowel biopsy was performed in 14 patients. Ten patients had villous atrophy. In one patient without villous atrophy, a repeat biopsy 2 years later showed villous atrophy, and two patients had increased intraepithelial lymphocytes without villous atrophy. Seventy percent of the patients with celiac disease were asymptomatic. The reported symptoms were abdominal pain and diarrhea (n = 1) and growth failure (n = 2). Two patients with celiac disease had Down syndrome. CONCLUSIONS The prevalence of celiac disease in children with juvenile diabetes in Wisconsin is at least 4.6%, which is comparable with European and Canadian studies. Because patients without villous atrophy may have latent celiac disease, the prevalence may be even higher. All children with juvenile diabetes should be screened for celiac disease.
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Affiliation(s)
- A N Aktay
- Division of Gastroenterology, Children's Hospital of Wisconsin, Milwaukee, Wisconsin, USA
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Lin YM, Teng YN, Lee PC, Lin YH, Hsu CC, Lin JS, Kuo PL. AZFa candidate gene deletions in Taiwanese patients with spermatogenic failure. J Formos Med Assoc 2001; 100:592-7. [PMID: 11695273] [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: 02/22/2023] Open
Abstract
BACKGROUND AND PURPOSE Deletions of the azoospermia factor subregion a (AZFa) genes in proximal Yq11 are not frequently reported. The majority of AZFa deletions are thought to be associated with more severe testicular phenotypes, such as Sertoli cell-only syndrome. There is a lack of data on AZFa gene deletions in East Asian populations. In this study, we investigated the deletion status of AZFa genes in Taiwanese men with spermatogenic failure. METHODS One hundred and eighty-three consecutive men with severe oligozoospermia or non-obstructive azoospermia were enrolled in this study. Genomic DNA was extracted from peripheral blood samples and polymerase chain reaction (PCR) was performed using primers specific to four AZFa genes: AZFaT1, DFFRY, DBY, and UTY. Sequence-tagged site markers (sY740, sY630, sY86, sY85, sY87, sY709, and sY88) were used to define the position of deletions. One hundred and twenty fertile men with normal spermatogenesis were enrolled as controls. RESULTS Of the 183 patients, two showed single AZFa gene deletions, resulting in an overall frequency of 1.1%. One of these two patients had DFFRY deletion and the other had DBY deletion; their testicular phenotypes were Sertoli cell-only syndrome and hypospermatogenesis, respectively. Neither patient had deletions extending from AZFa through AZFb or AZFc. CONCLUSION Our results suggest that AZFa gene deletion is infrequent in Taiwanese patients with severe oligozoospermia or non-obstructive azoospermia.
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Affiliation(s)
- Y M Lin
- Department of Urology, National Cheng Kung University, College of Medicine, Tainan
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