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Lau Q, Lee ZM, Shunmugarajoo A, Tan CY, Azmel A, Yap SY. Association of dengue serotypes and its complications: a retrospective cohort study. Med J Malaysia 2023; 78:372-378. [PMID: 37271848] [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: 06/06/2023]
Abstract
INTRODUCTION Dengue fever is an arthropod-borne disease and has a wide clinical spectrum. It is hypothesised that dengue serotypes could be a possible factor for such phenomena and therefore be a possible predictor for the development of severe dengue. METHOD A retrospective cohort study was done to explore the association between dengue serotypes and the various complications. All patients who underwent dengue serotyping from 1st January to 31st December 2018 in Tengku Ampuan Rahimah Hospital were selected. Serotypes were randomly done for admitted dengue patients. Notes were then retrieved for data collection. Secondary outcomes like length of stay and highest lactate level were also studied. Data analysis was done using SPSS version 20. RESULT A total of 193 patient records were included in the analysis. Chi-square test for independence indicated that the proportion of dengue complications between male and female were significantly different (χ2(1) = 11.37, p = 0.001). Dengue serotype was not associated with the development of dengue complications, total number of dengue complications, length of admission, lactate level and survival among the serotypes. Results of the binary logistic regression showed that men have thrice the odds (AOR = 3.3, 95% CI: 1.6 6.7) for developing dengue complications. One patient was found to be co-infected with serotype 2 and 3. CONCLUSION Our study did not reveal any association between the different dengue virus serotypes and its complications. Therefore, all dengue infection should be approached with equal meticulousness. There are possibilities that apart from serotype, dengue genotype and lineage would determine clinical outcome. However, more studies are required to study such associations.
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Affiliation(s)
- Q Lau
- Hospital Tengku Ampuan Rahimah, Internal Medicine Department, Ministry of Health, Selangor, Malaysia.
| | - Z M Lee
- Hospital Duchness of Kent, Internal Medicine, Ministry of Health, Sabah, Malaysia
| | - A Shunmugarajoo
- Hospital Tengku Ampuan Rahimah, Internal Medicine Department, Ministry of Health, Selangor, Malaysia
| | - C Y Tan
- Hospital Tengku Ampuan Rahimah, Infectious Disease Unit, Ministry of Health, Selangor, Malaysia
| | - A Azmel
- Hospital Tengku Ampuan Rahimah, Infectious Disease Unit, Ministry of Health, Selangor, Malaysia
| | - S Y Yap
- Hospital Tengku Ampuan Rahimah, Clinical Research Center (CRC), Ministry of Health, Selangor, Malaysia
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Spears RJ, Chrzastek A, Yap SY, Karu K, Aliev AE, Baker JR, Chudasama V. Unearthing the unique stability of thiophosphonium-C-terminal cysteine adducts on peptides and proteins. Chem Commun (Camb) 2022; 58:5359-5362. [PMID: 35394478 DOI: 10.1039/d2cc01090a] [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
Herein we report a fundamental discovery on the use of tris(dialkylamino)phosphine reagents for peptide and protein modification. We discovered that C-terminal thiophosphonium species, which are uniquely stable, could be selectively and rapidly generated from their disulfide counterparts. In sharp and direct contrast, internal thiophosphonium species rapidly degrade to dehydroalanine. We demonstrate this remarkable chemoselectivity on a bis-cysteine model peptide, and the formation of a stable C-terminal-thiophosphonium adduct on an antibody fragment, as well as characterise the species in various small molecule/peptide studies.
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Affiliation(s)
- Richard J Spears
- UCL Department of Chemistry, 20 Gordon Street, London WC1H 0AJ, UK.
| | - Alina Chrzastek
- UCL Department of Chemistry, 20 Gordon Street, London WC1H 0AJ, UK.
| | - Steven Y Yap
- UCL Department of Chemistry, 20 Gordon Street, London WC1H 0AJ, UK.
| | - Kersti Karu
- UCL Department of Chemistry, 20 Gordon Street, London WC1H 0AJ, UK.
| | - Abil E Aliev
- UCL Department of Chemistry, 20 Gordon Street, London WC1H 0AJ, UK.
| | - James R Baker
- UCL Department of Chemistry, 20 Gordon Street, London WC1H 0AJ, UK.
| | - Vijay Chudasama
- UCL Department of Chemistry, 20 Gordon Street, London WC1H 0AJ, UK.
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Yap SY, Frias B, Wren MC, Schöll M, Fox NC, Årstad E, Lashley T, Sander K. Discriminatory ability of next-generation tau PET tracers for Alzheimer's disease. Brain 2021; 144:2284-2290. [PMID: 33742656 PMCID: PMC8453387 DOI: 10.1093/brain/awab120] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 02/02/2021] [Accepted: 02/02/2021] [Indexed: 12/15/2022] Open
Abstract
A next generation of tau PET tracers for the imaging of Alzheimer’s disease and other dementias has recently been developed. Whilst the new compounds have now entered clinical studies, there is limited information available to assess their suitability for clinical applications. Head-to-head comparisons are urgently needed to understand differences in the radiotracer binding profiles. We characterized the binding of the tau tracers PI2620, RO948, MK6240 and JNJ067 in human post-mortem brain tissue from a cohort of 25 dementia cases and age-matched controls using quantitative phosphorimaging with tritium-labelled radiotracers in conjunction with phospho-tau specific immunohistochemistry. The four radiotracers depicted tau inclusions composed of paired helical filaments with high specificity, both in cases with Alzheimer’s disease and in primary tauopathy cases with concomitant Alzheimer’s disease pathology. In contrast, cortical binding to primary tauopathy in cases without paired helical filament tau was found to be within the range of age-matched controls. Off-target binding to monoamine oxidase B has been overcome, as demonstrated by heterologous blocking studies in basal ganglia tissue. The high variability of cortical tracer binding within the Alzheimer’s disease group followed the same pattern with each tracer, suggesting that all compounds are suited to differentiate Alzheimer’s disease from other dementias.
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Affiliation(s)
- Steven Y Yap
- Centre for Radiopharmaceutical Chemistry, Department of Imaging, University College London, London, UK.,Department of Chemistry, University College London, London, UK
| | - Barbara Frias
- Queen Square Brain Bank for Neurological Disorders, Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, UK.,Department of Neurodegenerative Disease, Queen Square Institute of Neurology, University College London, London, UK
| | - Melissa C Wren
- Centre for Radiopharmaceutical Chemistry, Department of Imaging, University College London, London, UK.,Department of Chemistry, University College London, London, UK.,Queen Square Brain Bank for Neurological Disorders, Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, UK.,Department of Neurodegenerative Disease, Queen Square Institute of Neurology, University College London, London, UK
| | - Michael Schöll
- Wallenberg Centre for Molecular and Translational Medicine and the Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, University of Gothenburg, 405 30 Gothenburg, Sweden.,Dementia Research Centre, Queen Square Institute of Neurology, University College London, London, UK
| | - Nick C Fox
- Dementia Research Centre, Queen Square Institute of Neurology, University College London, London, UK.,UK Dementia Research Institute, Queen Square Institute of Neurology, University College London, London, UK
| | - Erik Årstad
- Centre for Radiopharmaceutical Chemistry, Department of Imaging, University College London, London, UK.,Department of Chemistry, University College London, London, UK
| | - Tammaryn Lashley
- Queen Square Brain Bank for Neurological Disorders, Department of Clinical and Movement Neurosciences, Queen Square Institute of Neurology, University College London, London, UK.,Department of Neurodegenerative Disease, Queen Square Institute of Neurology, University College London, London, UK
| | - Kerstin Sander
- Centre for Radiopharmaceutical Chemistry, Department of Imaging, University College London, London, UK.,Department of Chemistry, University College London, London, UK
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Yap SY, Savoie H, Renard I, Burke BP, Sample HC, Michue-Seijas S, Archibald SJ, Boyle RW, Stasiuk GJ. Synthesis of a porphyrin with histidine-like chelate: an efficient path towards molecular PDT/SPECT theranostics. Chem Commun (Camb) 2020; 56:11090-11093. [PMID: 32812554 DOI: 10.1039/d0cc03958f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The goal of "personalised" medicine has seen a growing interest in the development of theranostic agents. Bifunctional, and targeted-trifunctional, theranostic water-soluble porphyrins with a histidine-like chelating group have been synthesised via copper-catalysed azide-alkyne cycloaddition (CuAAC) "click" chemistry in high yield and purity. They are capable of photodynamic treatment and [99mTc(CO)3]+ complexation for single-photon emission computed tomography (SPECT) imaging, with a radiochemical yield of >95%. The toxicity and phototoxicity were evaluated on HT-29 cells, DU145, and DU145-PSMA cell lines, with the targeted theranostic showing more potent phototoxicity towards DU145-PSMA expressing cells.
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Affiliation(s)
- Steven Y Yap
- Department of Chemistry and Biochemistry, Faculty of Science and Engineering, University of Hull, HU6 7RX, UK.
| | - Huguette Savoie
- Department of Chemistry and Biochemistry, Faculty of Science and Engineering, University of Hull, HU6 7RX, UK.
| | - Isaline Renard
- Department of Biomedical Sciences, University of Hull, Cottingham Road, Hull, HU6 7RX, UK and Positron Emission Tomography Research Centre, University of Hull, Cottingham Road, Hull, HU6 7RX, UK
| | - Benjamin P Burke
- Department of Biomedical Sciences, University of Hull, Cottingham Road, Hull, HU6 7RX, UK and Positron Emission Tomography Research Centre, University of Hull, Cottingham Road, Hull, HU6 7RX, UK
| | - Harry C Sample
- Department of Chemistry and Biochemistry, Faculty of Science and Engineering, University of Hull, HU6 7RX, UK.
| | - Saul Michue-Seijas
- Department of Chemistry and Biochemistry, Faculty of Science and Engineering, University of Hull, HU6 7RX, UK.
| | - Stephen J Archibald
- Department of Biomedical Sciences, University of Hull, Cottingham Road, Hull, HU6 7RX, UK and Positron Emission Tomography Research Centre, University of Hull, Cottingham Road, Hull, HU6 7RX, UK
| | - Ross W Boyle
- Department of Chemistry and Biochemistry, Faculty of Science and Engineering, University of Hull, HU6 7RX, UK.
| | - Graeme J Stasiuk
- Department of Biomedical Sciences, University of Hull, Cottingham Road, Hull, HU6 7RX, UK and Department of Imaging Chemistry and Biology, School of Biomedical Engineering and Imaging Sciences, King's College London, Fourth Floor Lambeth Wing, St Thomas' Hospital, London SE1 7EH, UK.
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Price TW, Yap SY, Gillet R, Savoie H, Charbonnière LJ, Boyle RW, Nonat AM, Stasiuk GJ. Evaluation of a Bispidine‐Based Chelator for Gallium‐68 and of the Porphyrin Conjugate as PET/PDT Theranostic Agent. Chemistry 2020; 26:7602-7608. [DOI: 10.1002/chem.201905776] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 01/27/2020] [Indexed: 12/18/2022]
Affiliation(s)
- Thomas W. Price
- School of Life SciencesFaculty of Health SciencesUniversity of Hull Cottingham Road Hull HU6 7RX UK
- Positron Emission Tomography Research CenterUniversity of Hull Cottingham Road Hull HU6 7RX UK
- Department of Imaging Chemistry and BiologySchool of Biomedical Engineering and Imaging SciencesKing's College London Cottingham Road London SE1 7EH UK
| | - Steven Y. Yap
- Chemistry, School of Mathematical and Physical SciencesUniversity of Hull Cottingham Road Hull HU6 7RX UK
| | - Raphaël Gillet
- Equipe de Synthèse pour l'Analyse (SynPA)CNRS, IPHC UMR 7178Université de Strasbourg 67000 Strasbourg France
| | - Huguette Savoie
- Chemistry, School of Mathematical and Physical SciencesUniversity of Hull Cottingham Road Hull HU6 7RX UK
| | - Loïc J. Charbonnière
- Equipe de Synthèse pour l'Analyse (SynPA)CNRS, IPHC UMR 7178Université de Strasbourg 67000 Strasbourg France
| | - Ross W. Boyle
- Chemistry, School of Mathematical and Physical SciencesUniversity of Hull Cottingham Road Hull HU6 7RX UK
| | - Aline M. Nonat
- Equipe de Synthèse pour l'Analyse (SynPA)CNRS, IPHC UMR 7178Université de Strasbourg 67000 Strasbourg France
| | - Graeme J. Stasiuk
- School of Life SciencesFaculty of Health SciencesUniversity of Hull Cottingham Road Hull HU6 7RX UK
- Positron Emission Tomography Research CenterUniversity of Hull Cottingham Road Hull HU6 7RX UK
- Department of Imaging Chemistry and BiologySchool of Biomedical Engineering and Imaging SciencesKing's College London Cottingham Road London SE1 7EH UK
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Yap SY, Price TW, Savoie H, Boyle RW, Stasiuk GJ. Selective radiolabelling with 68Ga under mild conditions: a route towards a porphyrin PET/PDT theranostic agent. Chem Commun (Camb) 2018; 54:7952-7954. [PMID: 29956694 DOI: 10.1039/c8cc03897j] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
A theranostic conjugate for use as a positron emission tomography (PET) radiotracer and as a photosensitiser for photodynamic therapy (PDT) has been synthesised. A water-soluble porphyrin was coupled with the bifunctional chelate, H4Dpaa.ga. This conjugate is capable of rapid 68Ga complexation under physiological conditions; with 93% and 80% radiochemical yields achieved, at pH 4.5 and pH 7.4 respectively, in 15 min at 25 °C. Photocytotoxicity was evaluated on HT-29 cells and showed the conjugate was capable of >50% cell death at 50 μM upon irradiation with light, while causing minimal toxicity in the absence of light (>95% cell survival).
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Affiliation(s)
- Steven Y Yap
- Chemistry, School of Mathematics and Physical Sciences, Faculty of Science and Engineering, University of Hull, HU6 7RX, UK.
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Yap SY, Traynor D. P124 A motivational interviewing (MI) intervention aimed at reducing sexual risk taking in men who have sex with men (MSM): the launch of a pilot service. Br J Vener Dis 2012. [DOI: 10.1136/sextrans-2012-050601c.124] [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: 11/04/2022]
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Yap SY. P170 A clinical case study of the use of motivational interviewing (MI) to address a HIV+ gay man's sexual risk taking and recreational drug use. Br J Vener Dis 2012. [DOI: 10.1136/sextrans-2012-050601c.170] [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: 11/04/2022]
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Yapp DTT, Yap SY. Lansium domesticum: skin and leaf extracts of this fruit tree interrupt the lifecycle of Plasmodium falciparum, and are active towards a chloroquine-resistant strain of the parasite (T9) in vitro. J Ethnopharmacol 2003; 85:145-150. [PMID: 12576213 DOI: 10.1016/s0378-8741(02)00375-6] [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] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Malaria remains a global problem in the light of chloroquine-resistant strains of Plasmodium falciparum. New compounds are needed for the development of novel antimalarial drugs. Seed, leaf, and fruit skin extracts of Lansium domesticum, a common fruit tree in South-East Asia, are used by indigenous tribes in Sabah, Malaysia for treating malaria. The skin and aqueous leaf extracts of the tree were found to reduce parasite populations of the drug sensitive strain (3D7) and the chloroquine-resistant strain (T9) of P. falciparum equally well. The skin extracts were also found to interrupt the lifecycle of the parasite. The data reported here indicate that extracts of L. domesticum are a potential source for compounds with activity towards chloroquine-resistant strains of P. falciparum.
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Affiliation(s)
- Donald T T Yapp
- The Institute of Health and Community Medicine, Universiti Malaysia Sarawak, 94300 Kota Samarahan, Malaysia.
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Abstract
Two ultrasonic techniques were compared for their ability to clean and shape root canals in extracted human teeth. One technique was recommended by the manufacturer (Cavi-Endo, Dentsply), while the other was a modification by the authors of the stepdown technique. Mesiobuccal root canals of molars were instrumented using these techniques, after which a silicone impression material was injected into the prepared canals. The roots were then split longitudinally and one half was stained for debris scoring while the silicone impressions were assessed for shape. The results showed that the modified technique produced significantly cleaner canals than the recommended technique. The shaping ability of both techniques was difficult to evaluate because of the complex morphology of molar root canals. The final shape of the prepared canal depended more on the initial shape than on the instrumentation technique.
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Affiliation(s)
- S Y Yap
- Department of Conservative Dentistry, Institute of Dental Surgery, London, UK
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