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Engku Nur Syafirah EAR, Che Azmi NA, Nik Hashim NHH, Muhd Besari A, Mustaffa N, Harun A, Chan YY. A rare and unusual cause of Vibrio cholerae non-O1, non-O139 causing spontaneous peritonitis in a patient with cirrhosis. Trop Biomed 2021; 38:183-186. [PMID: 33797544 DOI: 10.47665/tb.38.1.012] [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
Spontaneous bacterial peritonitis caused by Vibrio cholerae non-O1/ non-O139 is a rare phenomenon. V. cholerae is known as a common aetiology of epidemic diarrheal disease and rarely causes extra-gastrointestinal infections. In this report, a 52-year-old man presented to our hospital with a clinical scenario for chronic liver cirrhosis with low grade fever and loose stools. V. cholerae was isolated from peritoneal fluid culture, which was further confirmed as non-O1/ non-O139 strain by multiplex polymerase chain reaction. The patient was successfully treated with antimicrobial therapy and peritoneal drainage. This case represents the first isolation of V. cholerae non-O1/ non-O139 strain from peritoneal fluid.
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Affiliation(s)
- E A R Engku Nur Syafirah
- Department of Medical Microbiology and Parasitology, School of Medical Sciences, Universiti Sains Malaysia, Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia
| | - N A Che Azmi
- Department of Medical Microbiology and Parasitology, School of Medical Sciences, Universiti Sains Malaysia, Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia
| | - N H H Nik Hashim
- Department of Medical Microbiology and Parasitology, School of Medical Sciences, Universiti Sains Malaysia, Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia.,Hospital Universiti Sains Malaysia, Universiti Sains Malaysia, Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia
| | - A Muhd Besari
- Department of Medicine, School of Medical Sciences, Universiti Sains Malaysia, Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia.,Hospital Universiti Sains Malaysia, Universiti Sains Malaysia, Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia
| | - N Mustaffa
- Department of Medicine, School of Medical Sciences, Universiti Sains Malaysia, Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia.,Hospital Universiti Sains Malaysia, Universiti Sains Malaysia, Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia
| | - A Harun
- Department of Medical Microbiology and Parasitology, School of Medical Sciences, Universiti Sains Malaysia, Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia.,Hospital Universiti Sains Malaysia, Universiti Sains Malaysia, Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia
| | - Y Y Chan
- Department of Medical Microbiology and Parasitology, School of Medical Sciences, Universiti Sains Malaysia, Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia.,Hospital Universiti Sains Malaysia, Universiti Sains Malaysia, Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia
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2
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Radtke S, Pande D, Cui M, Perez AM, Chan YY, Enstrom M, Schmuck S, Berger A, Eunson T, Adair JE, Kiem HP. Purification of Human CD34 +CD90 + HSCs Reduces Target Cell Population and Improves Lentiviral Transduction for Gene Therapy. Mol Ther Methods Clin Dev 2020; 18:679-691. [PMID: 32802914 PMCID: PMC7424231 DOI: 10.1016/j.omtm.2020.07.010] [Citation(s) in RCA: 20] [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] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 07/09/2020] [Indexed: 01/09/2023]
Abstract
Hematopoietic stem cell (HSC) gene therapy has the potential to cure many genetic, malignant, and infectious diseases. We have shown in a nonhuman primate gene therapy and transplantation model that the CD34+CD90+ cell fraction was exclusively responsible for multilineage engraftment and hematopoietic reconstitution. In this study, we show the translational potential of this HSC-enriched CD34 subset for lentivirus-mediated gene therapy. Alternative HSC enrichment strategies include the purification of CD133+ cells or CD38low/– subsets of CD34+ cells from human blood products. We directly compared these strategies to the isolation of CD90+ cells using a good manufacturing practice (GMP) grade flow-sorting protocol with clinical applicability. We show that CD90+ cell selection results in about 30-fold fewer target cells in comparison to CD133+ or CD38low/– CD34+ hematopoietic stem and progenitor cell (HSPC) subsets without compromising the engraftment potential in vivo. Single-cell RNA sequencing confirmed nearly complete depletion of lineage-committed progenitor cells in CD90+ fractions compared to alternative selections. Importantly, lentiviral transduction efficiency in purified CD90+ cells resulted in up to 3-fold higher levels of engrafted gene-modified blood cells. These studies should have important implications for the manufacturing of patient-specific HSC gene therapy and gene-engineered cell products.
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Affiliation(s)
- Stefan Radtke
- Stem Cell and Gene Therapy Program, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.,Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Dnyanada Pande
- Stem Cell and Gene Therapy Program, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.,Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Margaret Cui
- Stem Cell and Gene Therapy Program, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.,Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Anai M Perez
- Stem Cell and Gene Therapy Program, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.,Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Yan-Yi Chan
- Stem Cell and Gene Therapy Program, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.,Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Mark Enstrom
- Stem Cell and Gene Therapy Program, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.,Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Stefanie Schmuck
- Stem Cell and Gene Therapy Program, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.,Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Andrew Berger
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Tom Eunson
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Jennifer E Adair
- Stem Cell and Gene Therapy Program, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.,Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.,Department of Medical Oncology, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Hans-Peter Kiem
- Stem Cell and Gene Therapy Program, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.,Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.,Department of Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA.,Department of Pathology, University of Washington School of Medicine, Seattle, WA 98195, USA
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3
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Mohd Ali MR, Foo PC, Hassan M, Maning N, Hussin A, Syed Ahmad Yunus SZ, Fauzi MH, Muhd Besar A, Harun A, Ismail N, Chan YY. Development and validation of TaqMan real-time PCR for the detection of Burkholderia pseudomallei isolates from Malaysia. Trop Biomed 2019; 36:379-389. [PMID: 33597399] [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
Rapid detection of Burkholderia pseudomallei, the etiologic agent of melioidosis, allows for timely initiation of appropriate treatment and better clinical outcomes. In the current gold standard, the culture method is time consuming and suffers from low sensitivity. Meanwhile, previously reported molecular assays are fast and sensitive, but their performance on isolates from Malaysia, an endemic region of melioidosis is under reported. This study designed oligonucleotides targeting orf2 of Type III secretion system (TTSS) genes cluster for the detection of Malaysian B. pseudomallei isolates and evaluated the assay on 95 local B. pseudomallei strains, 58 other microorganisms and 71 clinical specimens from patients. The developed assay exclusively detected all tested B. pseudomallei isolates with a detection limit of 20 fg per reaction (equivalent to ~2.5 copies). Subsequent testing on clinical samples showed that the assay detected all confirmed specimens with the growth of B. pseudomallei (n = 10/10). None of the negative specimens had a detectable signal of our TTSS-orf2 assay (n = 0/61). In conclusion, the present study provides crucial preliminary data for a subsequent study and should be considered as a potential alternative to current time-consuming culture method for the detection of B. pseudomallei.
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Affiliation(s)
- M R Mohd Ali
- Department of Medical Microbiology and Parasitology, School of Medical Sciences, Universiti Sains Malaysia, Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia
- Bacteriology Unit, Infectious Disease Research Center (IDRC), Institute for Medical Research (IMR), Complex National Institutes of Health (NIH), Section U13 Setia Alam, 40170 Shah Alam, Selangor, Malaysia
| | - P C Foo
- Department of Medical Microbiology and Parasitology, School of Medical Sciences, Universiti Sains Malaysia, Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia
- Acarology Unit, Infectious Disease Research Center (IDRC), Institute for Medical Research (IMR), Complex National Institutes of Health (NIH), Section U13 Setia Alam, 40170 Shah Alam, Selangor, Malaysia
| | - M Hassan
- Department of Pathology, Hospital Raja Perempuan Zainab II, 15586 Kota Bharu, Kelantan, Malaysia
| | - N Maning
- Department of Pathology, Hospital Raja Perempuan Zainab II, 15586 Kota Bharu, Kelantan, Malaysia
| | - A Hussin
- Department of Pathology, Hospital Raja Perempuan Zainab II, 15586 Kota Bharu, Kelantan, Malaysia
| | - S Z Syed Ahmad Yunus
- Bacteriology Unit, Infectious Disease Research Center (IDRC), Institute for Medical Research (IMR), Complex National Institutes of Health (NIH), Section U13 Setia Alam, 40170 Shah Alam, Selangor, Malaysia
| | - M H Fauzi
- Department of Emergency Medicine, School of Medical Science, Universiti Sains Malaysia, Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia
- Hospital Universiti Sains Malaysia, Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia
| | - A Muhd Besar
- Hospital Universiti Sains Malaysia, Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia
- Department of Medicine, School of Medical Science, Universiti Sains Malaysia, Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia
| | - A Harun
- Department of Medical Microbiology and Parasitology, School of Medical Sciences, Universiti Sains Malaysia, Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia
- Hospital Universiti Sains Malaysia, Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia
| | - N Ismail
- Department of Medical Microbiology and Parasitology, School of Medical Sciences, Universiti Sains Malaysia, Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia
- Hospital Universiti Sains Malaysia, Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia
| | - Y Y Chan
- Department of Medical Microbiology and Parasitology, School of Medical Sciences, Universiti Sains Malaysia, Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia
- Hospital Universiti Sains Malaysia, Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia
- Institute for Research in Molecular Medicine, Universiti Sains Malaysia, Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia
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4
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Abd Razak MA, Ahmad NA, Chan YY, Mohamad Kasim N, Yusof M, Abdul Ghani MKA, Omar M, Abd Aziz FA, Jamaluddin R. Validity of screening tools for dementia and mild cognitive impairment among the elderly in primary health care: a systematic review. Public Health 2019; 169:84-92. [PMID: 30826688 DOI: 10.1016/j.puhe.2019.01.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [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: 06/04/2018] [Revised: 12/14/2018] [Accepted: 01/02/2019] [Indexed: 12/30/2022]
Abstract
OBJECTIVES This systematic review aims to provide updated and comprehensive evidence on the validity and feasibility of screening tools for mild cognitive impairment (MCI) and dementia among the elderly at primary healthcare level. STUDY DESIGN A review of articles was performed. METHODS A search strategy was used by using electronic bibliographic databases including PubMed, Embase and CENTRAL for published studies and reference list of published studies. The articles were exported to a bibliographic database for further screening process. Two reviewers worked independently to screen results and extract data from the included studies. Any discrepancies were resolved and confirmed by the consensus of all authors. RESULTS There were three screening approaches for detecting MCI and dementia - screening by a healthcare provider, screening by a self-administered questionnaire and caretaker informant screening. Montreal Cognitive Assessment (MoCA) was the most common and preferable tool for MCI screening (sensitivity [Sn]: 81-97%; specificity [Sp]: 60-86%), whereas Addenbrooke's Cognitive Examination (ACE) was the preferable tool for dementia screening (Sn: 79-100%; Sp: 86%). CONCLUSION This systematic review found that there are three screening approaches for detecting early dementia and MCI at primary health care. ACE and MoCA are recommended tools for screening of dementia and MCI, respectively.
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Affiliation(s)
- M A Abd Razak
- Institute for Public Health, Ministry of Health Malaysia, Jalan Bangsar, 50590 Kuala Lumpur, W.P. Kuala Lumpur, Malaysia.
| | - N A Ahmad
- Institute for Public Health, Ministry of Health Malaysia, Jalan Bangsar, 50590 Kuala Lumpur, W.P. Kuala Lumpur, Malaysia.
| | - Y Y Chan
- Institute for Public Health, Ministry of Health Malaysia, Jalan Bangsar, 50590 Kuala Lumpur, W.P. Kuala Lumpur, Malaysia.
| | - N Mohamad Kasim
- Institute for Public Health, Ministry of Health Malaysia, Jalan Bangsar, 50590 Kuala Lumpur, W.P. Kuala Lumpur, Malaysia.
| | - M Yusof
- Women and Child Hospital Kuala Lumpur, Ministry of Health Malaysia, Jalan Dr Latiff, 50586 Kuala Lumpur, W.P. Kuala Lumpur, Malaysia.
| | - M K A Abdul Ghani
- Klinik Rafeeq & Nurul, Sungai Rengit, 81620 Pengerang, Johor, Malaysia.
| | - M Omar
- Kuala Selangor Health District, Ministry of Health Malaysia, Jalan Semarak, 45000 Kuala Selangor, Selangor, Malaysia.
| | - F A Abd Aziz
- Institute for Public Health, Ministry of Health Malaysia, Jalan Bangsar, 50590 Kuala Lumpur, W.P. Kuala Lumpur, Malaysia.
| | - R Jamaluddin
- Institute for Public Health, Ministry of Health Malaysia, Jalan Bangsar, 50590 Kuala Lumpur, W.P. Kuala Lumpur, Malaysia.
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5
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Radtke S, Adair JE, Giese MA, Chan YY, Norgaard ZK, Enstrom M, Haworth KG, Schefter LE, Kiem HP. A distinct hematopoietic stem cell population for rapid multilineage engraftment in nonhuman primates. Sci Transl Med 2018; 9:9/414/eaan1145. [PMID: 29093179 DOI: 10.1126/scitranslmed.aan1145] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 04/12/2017] [Accepted: 07/26/2017] [Indexed: 12/12/2022]
Abstract
Hematopoietic reconstitution after bone marrow transplantation is thought to be driven by committed multipotent progenitor cells followed by long-term engrafting hematopoietic stem cells (HSCs). We observed a population of early-engrafting cells displaying HSC-like behavior, which persisted long-term in vivo in an autologous myeloablative transplant model in nonhuman primates. To identify this population, we characterized the phenotype and function of defined nonhuman primate hematopoietic stem and progenitor cell (HSPC) subsets and compared these to human HSPCs. We demonstrated that the CD34+CD45RA-CD90+ cell phenotype is highly enriched for HSCs. This population fully supported rapid short-term recovery and robust multilineage hematopoiesis in the nonhuman primate transplant model and quantitatively predicted transplant success and time to neutrophil and platelet recovery. Application of this cell population has potential in the setting of HSC transplantation and gene therapy/editing approaches.
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Affiliation(s)
- Stefan Radtke
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.,Institute for Transfusion Medicine, University Hospital Essen, University of Duisburg-Essen, Essen 45147, Germany
| | - Jennifer E Adair
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.,Department of Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Morgan A Giese
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Yan-Yi Chan
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Zachary K Norgaard
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Mark Enstrom
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Kevin G Haworth
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Lauren E Schefter
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Hans-Peter Kiem
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA. .,Department of Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA.,Department of Pathology, University of Washington School of Medicine, Seattle, WA 98195, USA
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6
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Kee CC, Lim KH, Sumarni MG, Teh CH, Chan YY, Nuur Hafizah MI, Cheah YK, Tee EO, Ahmad Faudzi Y, Amal Nasir M. Validity of self-reported weight and height: a cross-sectional study among Malaysian adolescents. BMC Med Res Methodol 2017; 17:85. [PMID: 28577547 PMCID: PMC5457653 DOI: 10.1186/s12874-017-0362-0] [Citation(s) in RCA: 35] [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: 01/08/2017] [Accepted: 05/23/2017] [Indexed: 11/10/2022] Open
Abstract
Background Self-reported weight and height are commonly used in lieu of direct measurements of weight and height in large epidemiological surveys due to inevitable constraints such as budget and human resource. However, the validity of self-reported weight and height, particularly among adolescents, needs to be verified as misreporting could lead to misclassification of body mass index and therefore overestimation or underestimation of the burden of BMI-related diseases. The objective of this study was to determine the validity of self-reported weight and height among Malaysian secondary school children. Methods Both self-reported and directly measured weight and height of a subgroup of 663 apparently healthy schoolchildren from the Malaysian Adolescent Health Risk Behaviour (MyAHRB) survey 2013/2014 were analysed. Respondents were required to report their current body weight and height via a self-administrative questionnaire before they were measured by investigators. The validity of self-reported against directly measured weight and height was examined using intraclass correlation coefficient (ICC), the Bland-Altman plot and weighted Kappa statistics. Results There was very good intraclass correlation between self-reported and directly measured weight [r = 0.96, 95% confidence interval (CI): 0.93, 0.97] and height (r = 0.94, 95% CI: 0.90, 0.96). In addition the Bland-Altman plots indicated that the mean difference between self-reported and direct measurement was relatively small. The mean difference (self-reported minus direct measurements) was, for boys: weight, −2.1 kg; height, −1.6 cm; BMI, −0.44 kg/m2 and girls: weight, −1.2 kg; height, −0.9 cm; BMI, −0.3 kg/m2. However, 95% limits of agreement were wide which indicated substantial discrepancies between self-reported and direct measurements method at the individual level. Nonetheless, the weighted Kappa statistics demonstrated a substantial agreement between BMI status categorised based on self-reported weight and height and the direct measurements (kappa = 0.76, 95% CI: 0.67, 0.84). Conclusion Our results show that the self-reported weight and height were consistent with direct measurements and therefore can be used in assessing the nutritional status of Malaysian school children from the age of 13 to 17 years old in epidemiological studies and for surveillance purposes when direct measurements are not feasible, but not for assessing nutritional status at the individual level.
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Affiliation(s)
- C C Kee
- Epidemiology and Biostatistics Unit, Institute for Medical Research, Jalan Pahang, 50588, Kuala Lumpur, Malaysia.
| | - K H Lim
- Epidemiology and Biostatistics Unit, Institute for Medical Research, Jalan Pahang, 50588, Kuala Lumpur, Malaysia
| | - M G Sumarni
- Epidemiology and Biostatistics Unit, Institute for Medical Research, Jalan Pahang, 50588, Kuala Lumpur, Malaysia
| | - C H Teh
- Epidemiology and Biostatistics Unit, Institute for Medical Research, Jalan Pahang, 50588, Kuala Lumpur, Malaysia
| | - Y Y Chan
- Institute for Public Health, Jalan Bangsar, Federal Hill, 50590, Kuala Lumpur, Malaysia
| | - M I Nuur Hafizah
- Epidemiology and Biostatistics Unit, Institute for Medical Research, Jalan Pahang, 50588, Kuala Lumpur, Malaysia
| | - Y K Cheah
- Universiti Utara Malaysia, UUM, 06010, Sintok, Kedah, Malaysia
| | - E O Tee
- Allied Health Sciences College Sg. Buloh, Jalan Hospital, 47000, Sg. Buloh, Selangor, Malaysia
| | - Y Ahmad Faudzi
- Epidemiology and Biostatistics Unit, Institute for Medical Research, Jalan Pahang, 50588, Kuala Lumpur, Malaysia
| | - M Amal Nasir
- Epidemiology and Biostatistics Unit, Institute for Medical Research, Jalan Pahang, 50588, Kuala Lumpur, Malaysia
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7
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Gori JL, Butler JM, Chan YY, Chandrasekaran D, Poulos MG, Ginsberg M, Nolan DJ, Elemento O, Wood BL, Adair JE, Rafii S, Kiem HP. Vascular niche promotes hematopoietic multipotent progenitor formation from pluripotent stem cells. J Clin Invest 2015; 125:1243-54. [PMID: 25664855 DOI: 10.1172/jci79328] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 01/05/2015] [Indexed: 01/08/2023] Open
Abstract
Pluripotent stem cells (PSCs) represent an alternative hematopoietic stem cell (HSC) source for treating hematopoietic disease. The limited engraftment of human PSC-derived (hPSC-derived) multipotent progenitor cells (MPP) has hampered the clinical application of these cells and suggests that MPP require additional cues for definitive hematopoiesis. We hypothesized that the presence of a vascular niche that produces Notch ligands jagged-1 (JAG1) and delta-like ligand-4 (DLL4) drives definitive hematopoiesis. We differentiated hes2 human embryonic stem cells (hESC) and Macaca nemestrina-induced PSC (iPSC) line-7 with cytokines in the presence or absence of endothelial cells (ECs) that express JAG1 and DLL4. Cells cocultured with ECs generated substantially more CD34+CD45+ hematopoietic progenitors compared with cells cocultured without ECs or with ECs lacking JAG1 or DLL4. EC-induced cells exhibited Notch activation and expressed HSC-specific Notch targets RUNX1 and GATA2. EC-induced PSC-MPP engrafted at a markedly higher level in NOD/SCID/IL-2 receptor γ chain-null (NSG) mice compared with cytokine-induced cells, and low-dose chemotherapy-based selection further increased engraftment. Long-term engraftment and the myeloid-to-lymphoid ratio achieved with vascular niche induction were similar to levels achieved for cord blood-derived MPP and up to 20-fold higher than those achieved with hPSC-derived MPP engraftment. Our findings indicate that endothelial Notch ligands promote PSC-definitive hematopoiesis and production of long-term engrafting CD34+ cells, suggesting these ligands are critical for HSC emergence.
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8
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Teh CH, Lim KK, Chan YY, Lim KH, Azahadi O, Hamizatul Akmar AH, Ummi Nadiah Y, Syafinaz MS, Kee CC, Yeo PS, Fadhli Y. The prevalence of physical activity and its associated factors among Malaysian adults: findings from the National Health and Morbidity Survey 2011. Public Health 2014; 128:416-23. [PMID: 24726414 DOI: 10.1016/j.puhe.2013.10.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [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: 10/25/2012] [Revised: 10/14/2013] [Accepted: 10/15/2013] [Indexed: 11/15/2022]
Abstract
OBJECTIVES Despite the health-enhancing benefits of physical activity, a large segment of the Malaysian population does not engage in regular physical activity at the recommended level. This study aimed to determine physical activity patterns and the associated sociodemographic correlates of physical activity. STUDY DESIGN Data on physical activity were obtained from the National Health and Morbidity Survey (NHMS) 2011, a nationally representative, population-based cross-sectional study. A two-stage stratified sampling method was used to select a representative sample of Malaysian adults aged 16 years and above. METHODS A total of 19,145 adults aged 16 years and above were recruited, and face-to-face interviews were conducted using the International Physical Activity Questionnaire (IPAQ), short version. The correlates for physical activity were identified using multivariate analysis. RESULTS In this study, 64.3% (95%CI: 63.1-65.5) of Malaysian adults aged 16 and above were physically active, but overall physical activity levels decreased with advancing age. Men, rural residents, 'other' ethnic groups, and married women were more likely to demonstrate higher levels of physical activity. CONCLUSION Approximately 65% of Malaysian adults were physically active. However, it is recommended that health promotions for active lifestyles should be targeted to the least active segments, which constitute more than a quarter of the Malaysian population.
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Affiliation(s)
- C H Teh
- Institute for Public Health, Ministry of Health Malaysia, Jalan Bangsar, 50590 Kuala Lumpur, Malaysia.
| | - K K Lim
- Institute for Public Health, Ministry of Health Malaysia, Jalan Bangsar, 50590 Kuala Lumpur, Malaysia
| | - Y Y Chan
- Institute for Public Health, Ministry of Health Malaysia, Jalan Bangsar, 50590 Kuala Lumpur, Malaysia
| | - K H Lim
- Institute for Public Health, Ministry of Health Malaysia, Jalan Bangsar, 50590 Kuala Lumpur, Malaysia
| | - O Azahadi
- Institute for Public Health, Ministry of Health Malaysia, Jalan Bangsar, 50590 Kuala Lumpur, Malaysia
| | - A H Hamizatul Akmar
- Institute for Public Health, Ministry of Health Malaysia, Jalan Bangsar, 50590 Kuala Lumpur, Malaysia
| | - Y Ummi Nadiah
- Institute for Public Health, Ministry of Health Malaysia, Jalan Bangsar, 50590 Kuala Lumpur, Malaysia
| | - M S Syafinaz
- Institute for Public Health, Ministry of Health Malaysia, Jalan Bangsar, 50590 Kuala Lumpur, Malaysia
| | - C C Kee
- Institute for Medical Research, Ministry of Health Malaysia, Jalan Pahang, 50588 Kuala Lumpur, Malaysia
| | - P S Yeo
- Institute for Public Health, Ministry of Health Malaysia, Jalan Bangsar, 50590 Kuala Lumpur, Malaysia
| | - Y Fadhli
- Institute for Public Health, Ministry of Health Malaysia, Jalan Bangsar, 50590 Kuala Lumpur, Malaysia
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9
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Cheung E, Bow C, Loong C, Lee KK, Ho AYY, Soong C, Chan YY, Tan KCB, Kung AWC. A secular increase in BMD in Chinese women. J Bone Miner Metab 2014; 32:48-55. [PMID: 23636506 DOI: 10.1007/s00774-013-0463-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [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] [Received: 08/02/2012] [Accepted: 03/19/2013] [Indexed: 02/04/2023]
Abstract
Population-based studies have revealed a decline in the incidence of age-adjusted hip fractures in southern Chinese women during the past decade. To determine whether there was a secular change in population characteristics that accounted for this decline, we compared the bone mineral density (BMD) and lifestyle habits of two cohorts of women who were more than 50 years of age and who were recruited from 1995 to 2000 and 2005 to 2010. The BMD levels in the 2005-2010 cohort were significantly higher at the spine and hip and ranged from 3.6 to 17.8% among the different age groups. Additionally, a significantly lower prevalence of subjects with osteoporosis and osteopenia was observed. Longer reproductive years, higher levels of physical activity, higher estradiol and 25(OH) vitamin D levels, and lower alkaline phosphatase levels were found in the 2005-2010 cohort. After adjusting for bone-determining factors, significant differences were detected in the BMD levels at the lumbar spine, femoral neck, and total hip (4.17, 9.02, and 9.34%, respectively) in women >50 years of age but not in women ≤50 years of age. The secular increase in BMD and healthier lifestyles most likely led to the decline in the incidence of age-adjusted fractures.
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Affiliation(s)
- Elaine Cheung
- Department of Medicine, The University of Hong Kong and Queen Mary Hospital, Hospital Authority, Hong Kong, China
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Chan YY, Kim KH, Cheah SH. Inhibitory effects of Sargassum polycystum on tyrosinase activity and melanin formation in B16F10 murine melanoma cells. J Ethnopharmacol 2011; 137:1183-8. [PMID: 21810462 DOI: 10.1016/j.jep.2011.07.050] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2010] [Revised: 05/27/2011] [Accepted: 07/18/2011] [Indexed: 05/31/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Sargassum polycystum, a type of brown seaweed, has been used for the treatment of skin-related disorders in traditional medicine. AIM OF THE STUDY The aim of the present study is to investigate the antimelanogenesis effect of Sargassum polycystum extracts by cell-free mushroom tyrosinase assay followed by cell viability assay, cellular tyrosinase assay and melanin content assay using B16F10 murine melanoma cells. MATERIALS AND METHODS Sargassum polycystum was extracted with 95% ethanol and further fractionated with hexane, ethyl acetate and water. The ethanolic crude extract and its fractionated extracts were tested for their potential to act as antimelanogenesis or skin-whitening agents by their abilities to inhibit tyrosinase activity in the cell-free mushroom tyrosinase assay and cellular tyrosinase derived from melanin-forming B16F10 murine melanoma cells. The tyrosinase inhibitory activity was correlated to the inhibition of melanin production in α-MSH-stimulated and unstimulated B16F10 cells. RESULTS Sargassum polycystum ethanolic extract and its fractions had little or no inhibitory effect on mushroom tyrosinase activity. However, when tested on cellular tyrosinase, the ethanolic extract and its non-polar fraction, hexane fraction (SPHF), showed significant inhibition of cellular tyrosinase activity. In parallel to its cellular tyrosinase inhibitory activity, SPHF was also able to inhibit basal and α-MSH-stimulated melanin production in B16F10 cells. CONCLUSIONS Our findings showed that (i) cellular tyrosinase assay is more reliable than mushroom tyrosinase assay in the initial testing of potential antimelanogenesis agents and, (ii) SPHF inhibited melanogenesis by inhibiting cellular tyrosinase activity. SPHF may be useful for treating hyperpigmentation and as a skin-whitening agent in cosmetics industry.
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Affiliation(s)
- Y Y Chan
- Department of Physiology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia
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Chan YY, Jayaprakasan K, Tan A, Thornton JG, Coomarasamy A, Raine-Fenning NJ. Reproductive outcomes in women with congenital uterine anomalies: a systematic review. Ultrasound Obstet Gynecol 2011; 38:371-382. [PMID: 21830244 DOI: 10.1002/uog.10056] [Citation(s) in RCA: 251] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
OBJECTIVE Congenital uterine anomalies are common but their effect on reproductive outcome is unclear. We conducted a systematic review to evaluate the association between different types of congenital uterine anomaly and various reproductive outcomes. METHODS Searches were performed using MEDLINE, EMBASE, the Cochrane Library and Web of Science. The Newcastle-Ottawa Quality Assessment Scale was used for quality assessment. Uterine defects were grouped into arcuate uteri, canalization defects (septate and subseptate uteri) and unification defects (unicornuate, bicornuate and didelphys uteri). Pooled risk ratios (RR) with 95% confidence intervals (CI) were computed using random effects models. RESULTS We identified nine studies comprising 3805 women. Meta-analysis showed that arcuate uteri were associated with increased rates of second-trimester miscarriage (RR, 2.39; 95% CI, 1.33-4.27, P = 0.003) and fetal malpresentation at delivery (RR, 2.53; 95% CI, 1.54-4.18; P < 0.001). Canalization defects were associated with reduced clinical pregnancy rates (RR, 0.86; 95% CI, 0.77-0.96; P = 0.009) and increased rates of first-trimester miscarriage (RR, 2.89; 95% CI; 2.02-4.14; P < 0.001), preterm birth (RR, 2.14; 95% CI, 1.48-3.11; P < 0.001) and fetal malpresentation (RR, 6.24; 95% CI, 4.05-9.62; P < 0.001). Unification defects were associated with increased rates of preterm birth (RR, 2.97; 95% CI, 2.08-4.23; P < 0.001) and fetal malpresentation (RR, 3.87; 95% CI, 2.42-6.18; P < 0.001). CONCLUSIONS Canalization defects reduce fertility and increase rates of miscarriage and preterm delivery. None of the unification defects reduces fertility but some are associated with miscarriage and preterm delivery. Arcuate uteri are specifically associated with second-trimester miscarriage. All uterine anomalies increase the chance of fetal malpresentation at delivery.
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Affiliation(s)
- Y Y Chan
- Department of Obstetrics and Gynaecology, Nottingham University Hospitals NHS Trust, Derby Road, Nottingham, UK.
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Chan YY, Jayaprakasan K, Zamora J, Thornton JG, Raine-Fenning N, Coomarasamy A. The prevalence of congenital uterine anomalies in unselected and high-risk populations: a systematic review. Hum Reprod Update 2011; 17:761-71. [PMID: 21705770 PMCID: PMC3191936 DOI: 10.1093/humupd/dmr028] [Citation(s) in RCA: 349] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND The prevalence of congenital uterine anomalies in high-risk women is unclear, as several different diagnostic approaches have been applied to different groups of patients. This review aims to evaluate the prevalence of such anomalies in unselected populations and in women with infertility, including those undergoing IVF treatment, women with a history of miscarriage, women with infertility and recurrent miscarriage combined, and women with a history of preterm delivery. METHODS Searches of MEDLINE, EMBASE, Web of Science and the Cochrane register were performed. Study selection and data extraction were conducted independently by two reviewers. Studies were grouped into those that used ‘optimal’ and ‘suboptimal’ tests for uterine anomalies. Meta-analyses were performed to establish the prevalence of uterine anomalies and their subtypes within the various populations. RESULTS We identified 94 observational studies comprising 89 861 women. The prevalence of uterine anomalies diagnosed by optimal tests was 5.5% [95% confidence interval (CI), 3.5–8.5] in the unselected population, 8.0% (95% CI, 5.3–12) in infertile women, 13.3% (95% CI, 8.9–20.0) in those with a history of miscarriage and 24.5% (95% CI, 18.3–32.8) in those with miscarriage and infertility. Arcuate uterus is most common in the unselected population (3.9%; 95% CI, 2.1–7.1), and its prevalence is not increased in high-risk groups. In contrast, septate uterus is the most common anomaly in high-risk populations. CONCLUSIONS Women with a history of miscarriage or miscarriage and infertility have higher prevalence of congenital uterine anomalies compared with the unselected population.
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Affiliation(s)
- Y Y Chan
- Department of Obstetrics and Gynaecology, Nottingham University Hospitals NHS Trust, Queen's Medical Centre Campus, Derby Road, Nottingham NG7 2UH, UK.
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Jayaprakasan K, Chan YY, Sur S, Deb S, Clewes JS, Raine-Fenning NJ. Prevalence of uterine anomalies and their impact on early pregnancy in women conceiving after assisted reproduction treatment. Ultrasound Obstet Gynecol 2011; 37:727-732. [PMID: 21337662 DOI: 10.1002/uog.8968] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 02/12/2011] [Indexed: 05/30/2023]
Abstract
OBJECTIVE To estimate the prevalence of congenital uterine anomalies in subfertile women and to evaluate their influence on early pregnancy following assisted reproduction treatment (ART). METHODS We prospectively recruited 1402 subjects undergoing ART over a period of 5 years from 2005 to 2009. Three-dimensional transvaginal sonography was performed in the early follicular phase of the menstrual cycle (days 2-5) and repeated in the late follicular phase (days 10-14) if the shape of the uterine cavity could not be assessed at the first scan. All subjects who conceived following ART were followed up to 12 weeks' gestation. Chi-square test was used to compare the pregnancy rates and miscarriage rates between women shown to have uterine anomalies and those with a normal uterus. RESULTS One thousand three hundred and eighty-five subjects were included for final analysis after excluding 17 subjects in whom a definitive diagnosis could not be made. While 1201 (86.7%) subjects had a normal uterine cavity, uterine anomalies were demonstrated in 184 (13.3%) subjects. Arcuate uteri represented the commonest anomaly (n = 164 (11.8%)) followed by septate (n = 7 (0.5%)), unicornuate (n = 6 (0.4%)), subseptate (n = 5 (0.4%)), bicornuate (n = 1 (0.1%)) and T-shaped uteri (n = 1 (0.1%)). A total of 440 subjects who underwent ART were followed up. The pregnancy rates in women with arcuate uteri (36/66 (54.5%)) and major uterine anomalies (7/10 (70.0%)) were statistically similar (P = 0.09 and P = 0.11, respectively) to that of the matched controls with normal uteri (158/364 (43.4%)). While first-trimester miscarriage rates were similar (P = 0.81) between the control group (20/158 (12.7%)) and women with arcuate uteri (5/36 (13.9%)), women with major uterine anomalies experienced a higher miscarriage rate (3/7 (42.9%); P = 0.05). CONCLUSIONS Women who are referred for ART have a high prevalence of congenital uterine anomalies, the most common anomaly being an arcuate uterus. These anomalies are not associated with a reduction in pregnancy rates following ART. However, while the arcuate uterus was not associated with an increase in first-trimester miscarriage, major uterine anomalies seemed to increase the risk of first-trimester miscarriage.
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Affiliation(s)
- K Jayaprakasan
- Nottingham University Research and Treatment Unit in Reproduction, Division of Human Development, School of Clinical Sciences, University of Nottingham, Nottingham, UK.
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Man BL, Baum L, Fu YP, Chan YY, Lam W, Hui CF, Leung WH, Wong KS. Genetic polymorphisms of Chinese patients with ischemic stroke and concurrent stenoses of extracranial and intracranial vessels. J Clin Neurosci 2010; 17:1244-7. [PMID: 20615707 DOI: 10.1016/j.jocn.2010.01.050] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2009] [Revised: 01/09/2010] [Accepted: 01/17/2010] [Indexed: 01/30/2023]
Abstract
The etiology of concurrent stenoses of extracranial and intracranial vessels in patients with ischemic stroke is poorly understood, but hereditary factors are believed to be important. We aimed to determine whether genetic polymorphisms affecting homocysteine and lipid metabolism are associated with concurrent stenoses. The genotypes of 191 Han Chinese patients with acute ischemic stroke, of whom 47 (25%) had concurrent stenoses, and 167 healthy control patients in Hong Kong were examined for the following polymorphisms: paraoxonase 1 (PON1) Q192R, methylenetetrahydrofolate reductase (MTHFR) A222V, glutamate-cysteine ligase catalytic-subunit (GCLC)-129C>T, and oxidized low-density lipoprotein receptor (OLR) 3' untranslated region C>T (rs1050283). The genotype distributions of PON1 Q192R and MTHFR A222V, which affect lipid and homocysteine metabolism, differed significantly between patients with stroke and healthy controls. The presence of at least one R allele in PON1 Q192R and a TT allele in OLR rs1050283 were associated with concurrent stenoses. We also identified a possible association between the presence of at least one V allele in MTHFR A222V and concurrent stenoses. This study shows that genetic polymorphisms affecting homocysteine and lipid metabolism are possible risk factors for stroke and concurrent stenoses.
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Affiliation(s)
- B L Man
- Department of Medicine and Geriatrics, Division of Neurology, Tuen Mun Hospital, 23 Tsing Chung Koon Road, Tuen Mun, New Territories, Hong Kong, China.
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Asmal HS, Mustafa M, Abdullah S, Zaidah AR, Nurhaslindawati AR, Sarimah A, Chan YY, Ravichandran M. Pneumocystis pneumonia among HIV patients in Malaysia. Southeast Asian J Trop Med Public Health 2009; 40:1293-1297. [PMID: 20578464] [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: 05/29/2023]
Abstract
Pneumocystis pneumonia (PCP) has become the most common opportunistic infection in HIV/AIDS patients with a CD4 count < or = 200. The incidence of PCP has declined as a result of prophylaxis and better highly active antiretroviral therapy (HAART). The objective of this study was to review the demographic data of HIV patients diagnosed clinically as having PCP at the Hospital Raja Perempuan Zainab II (HRPZ II) in Malaysia. This was a prospective study. All HIV patients admitted to HRPZ II with respiratory symptoms were enrolled in this study after giving informed consent. Their demographic data were collected. The total number of HIV patients reviewed in this study was 107. Nearly 60% of patients were clinically diagnosed as having pneumocystis pneumonia based on their signs, symptoms and chest x-ray findings. A CD4 count was available in 83 out of 107 patients. The fifty-three percent of patients(44) had a CD4 < 200 and were clinically diagnosed as having pneumocystis pneumonia. Thirty percent had a CD4 < 200 but did not have clinical pneumocystis pneumonia. Sixteen point nine percent had a CD4 > 200 and had clinical pneumocystis pneumonia, three of whom had received HAART, four patients had received prophylaxis. Overall, 94 patients (87.8%) received prophylaxis for pneumocystis pneumonia. Thirty-three patients (30.8%) received HAART. The occurrence of pneumocystis pneumonia was common before full implementation of HAART. Pneumocystis pneumonia can occur in patients with a CD4 >200.
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Affiliation(s)
- H Siti Asmal
- Department of Medical Microbiology and Parasitology, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Malaysia.
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Kwan TK, Ma ESK, Chan YY, Wan TSK, Liu HSY, Sim JPY, Yeung YM, Lie AKW, Yip SF. BCR-ABL mutational studies for predicting the response of patients with chronic myeloid leukaemia to second-generation tyrosine kinase inhibitors after imatinib failure. Hong Kong Med J 2009; 15:365-373. [PMID: 19801694] [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: 05/28/2023] Open
Abstract
Imatinib is the standard treatment for chronic myeloid leukaemia. BCR-ABL kinase domain mutation is the commonest mechanism implicated in imatinib resistance. In in-vitro studies, kinase domain mutations are variably resistant to second-line agents. We performed BCR-ABL kinase domain mutational studies in 25 patients in five institutions who failed imatinib and were treated with either nilotinib or dasatinib, to see if their mutational status would predict their clinical responses. Kinase domain mutations involving 11 amino acid substitutions were found in 12 (48%) patients. Most patients showed single kinase domain mutations. There was some concordance between reported drug sensitivity patterns and patient responses. Discordant responses could be related to drug dosage variations and unknown BCR-ABL independent mechanisms. The response prediction for patients with multiple kinase domain mutations was challenging and their mutational patterns could change after tyrosine kinase inhibitor therapy. Although BCR-ABL kinase domain mutational analysis has limitations as a means of predicting the clinical response to second-line tyrosine kinase inhibitors, it helps inform therapy decisions in the management of chronic myeloid leukaemia after imatinib failure.
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Affiliation(s)
- T K Kwan
- Department of Pathology, Queen Mary Hospital, Pokfulam Road, Hong Kong
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17
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Man BL, Fu YP, Chan YY, Lam W, Hui CF, Leung WH, Wong KS. Use of magnetic resonance angiography to predict long-term outcomes of ischemic stroke patients with concurrent stenoses in Hong Kong. Cerebrovasc Dis 2009; 28:112-8. [PMID: 19506369 DOI: 10.1159/000223435] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2008] [Accepted: 03/16/2009] [Indexed: 11/19/2022] Open
Abstract
PURPOSE To determine the long-term outcome of ischemic stroke patients with concurrent intracranial and extracranial atherosclerosis using magnetic resonance angiography. METHODS A prospective cohort of patients in Hong Kong with acute ischemic stroke was studied with magnetic resonance angiography of the brain and carotid duplex. All patients were followed up regularly for the development of recurrent stroke, cardiac events, or death. RESULTS Totally 343 patients with acute ischemic stroke were included, of whom 104 (30%) had concurrent intracranial and extracranial lesions. The follow-up period was up to 76 months (mean 44.5 months). Overall, 55 patients (15.5%) died of any cause and 91 patients (26.5%) suffered a further nonfatal vascular event. The overall 5-year cumulative rates of mortality, restroke and poor outcomes (combined death and further vascular events) were 18, 27 and 37%, respectively. In patients with concurrent lesions, these rates were 31, 41 and 51%, respectively. The corresponding rates were 13, 22 and 31% in patients without concurrent lesions. The risks were highest in the first year after stroke. More deaths (log rank, 16.3; p = 0.0001), restrokes (log rank, 9.71; p = 0.002) and poor outcomes (log rank, 13.87; p = 0.0001) were found among patients with concurrent lesions. The presence of concurrent vascular lesions, advanced age, smoking, hyperlipidemia and previous history of stroke were independent predictors of poor outcomes. CONCLUSIONS The long-term prognosis of ischemic stroke patients with concurrent atherosclerosis of intracranial and extracranial vessels is poor. They are at high risk of further vascular events or death.
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Affiliation(s)
- B L Man
- Division of Neurology, Department of Medicine and Geriatrics, Tuen Mun Hospital, Hong Kong, SAR, China.
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18
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Zaidah AR, Chan YY, Asma HS, Abdullah S, Nurhaslindawati AR, Salleh M, Zeehaida M, Lalitha P, Mustafa M, Ravichandran M. Detection of Cryptosporidium parvum in HIV-infected patients in Malaysia using a molecular approach. Southeast Asian J Trop Med Public Health 2008; 39:511-516. [PMID: 18564692] [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: 05/26/2023]
Abstract
This cross-sectional study determined the prevalence of cryptosporidiosis in HIV-infected patients using polymerase chain reaction (PCR). Stool specimens were collected from HIV infected patients who were admitted to Hospital Raja Perempuan Zainab II, Kota Bharu, Malaysia, for various indications from December 2004 to December 2005. A modified acid-fast stain was performed on the direct stool smears, then the stool specimens were further tested using nested PCR targeting the 18S rRNA gene of Cryptosporidium parvum, with a built-in internal control (IC). Out of 59 samples, 11 were positives. Nested PCR identified a total of nine samples (16%) compared to microscopy, which identified only three samples. All PCR negative results showed IC amplicons, suggesting that these samples were true negatives and were not due to inhibition of PCR. This study highlights the importance of molecular diagnosis in determining the true prevalence and epidemiology of C. parvum.
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Affiliation(s)
- A R Zaidah
- Department of Medical Microbiology and Parasitology, School of Health Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia.
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Chow KM, Chan YY, Choi PCL, Szeto CC. Cholestasis in an elderly patient with pneumonia. Intern Med J 2007; 37:832-3. [PMID: 18028086 DOI: 10.1111/j.1445-5994.2007.01507.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- K M Chow
- Department of Medicine & Therapeutics, Prince of Wales Hospital, The Chinese Uinversity of Hong Kong, Shatin, Hong Kong SAR
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Abstract
Burkholderia pseudomallei, the causative agent of melioidosis, is intrinsically resistant to a wide range of antimicrobial agents, including beta-lactams, aminoglycosides, macrolides, and polymyxins. An operon, bpeR-bpeA-bpeB-oprB, which encodes a putative repressor, a membrane fusion protein, an inner membrane protein, and an outer membrane protein, respectively, of a multidrug efflux pump of the resistance-nodulation-division family was identified in B. pseudomallei. The divergently transcribed bpeR gene encodes a putative repressor protein of the TetR family which probably regulates the expression of the bpeAB-oprB gene cluster. Comparison of the MICs and minimal bactericidal concentrations of antimicrobials for bpeAB deletion mutant KHW Delta bpeAB and its isogenic wild-type parent, KHW, showed that the B. pseudomallei BpeAB-OprB pump is responsible for the efflux of the aminoglycosides gentamicin and streptomycin, the macrolide erythromycin, and the dye acriflavine. Antibiotic efflux by the BpeAB-OprB pump was dependent on a proton gradient and differs from that by the AmrAB-OprA pump in that it did not efflux the aminoglycoside spectinomycin or the macrolide clarithromycin. The broad-spectrum efflux pump inhibitor MC-207,110 did not potentiate the effectiveness of the antimicrobials erythromycin and streptomycin in B. pseudomallei.
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Affiliation(s)
- Y Y Chan
- Department of Biochemistry, Faculty of Medicine, National University of Singapore, Singapore 117597, Singapore
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Abstract
Burkholderia pseudomallei, a facultatively intracellular pathogen, is a flagellated and motile gram-negative bacterium and is the causative agent of melioidosis in humans. Flagella are commonly recognized as important virulence determinants expressed by bacterial pathogens since the motility phenotype imparted by these organelles often correlates with the ability of an organism to cause disease. We used a virulent isolate of B. pseudomallei, KHW, to construct an isogenic deletion mutant with a mutation in the flagellin gene (fliC) by gene replacement transposon mutagenesis. The KHWDeltafliCKm mutant was aflagellate and nonmotile in semisolid agar. The isogenic KHWDeltafliCKm mutant was not impaired in terms of the ability to invade and replicate in cultured human lung cells compared with the wild type. It was also equally virulent in slow-killing assays involving Caenorhabditis elegans, but it was avirulent during intranasal infection of BALB/c mice. Very few bacteria, if any, were isolated from the lungs and spleens of KHWDeltafliCKm-infected mice. In contrast, the bacterial loads in the lungs and spleens were similar in mice infected with KHW and in mice infected with the complemented mutant, KHWDeltafliCKm/pUCP28TfliC. Unlike the Syrian hamster or diabetic rat models of infection, the B. pseudomallei flagellin was also a virulence factor during intraperitoneal infection of BALB/c mice. In this study, all animals infected with KHWDeltafliCKm remained healthy and did not succumb to disease regardless of the route of infection. The flagellum is therefore an important and necessary virulence determinant of B. pseudomallei during intranasal and intraperitoneal infection of mice.
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Affiliation(s)
- K L Chua
- Department of Biochemistry, National University of Singapore, Faculty of Medicine, 10 Kent Ridge Crescent, Singapore 119260.
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Chan YY, Bishop NJ. Clinical management of childhood osteoporosis. Int J Clin Pract 2002; 56:280-6. [PMID: 12074211] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/25/2023] Open
Abstract
A current working definition of osteoporosis in children is 'fragility fractures in association with low bone mass'. This review illustrates the determinants of bone mass and fracture risk. We elucidate the pathophysiology and causes of osteoporosis in various childhood disorders, with a particular focus on the commonest iatrogenic problem, glucocorticoid-induced osteoporosis. We discuss clinical evaluation, investigation and multidisciplinary management including lifestyle advice, diet, physiotherapy and occupational therapy, drug treatments and monitoring for children with osteoporosis. We also emphasise the important concepts of bone mass assessment and interpretation in children.
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Affiliation(s)
- Y Y Chan
- University of Sheffield, Sheffield Children's Hospital, Yorkshire, UK
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Abstract
Five new sesquiterpenes, mandolins R (1), S (2), U (3), W (4), and X (5), together with 39 known compounds, were isolated from the dried roots and stems of Aristolochia mollissima. Their structures were determined by spectroscopic methods.
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Affiliation(s)
- T S Wu
- Department of Chemistry, National Cheng Kung University, Tainan, Taiwan 701, Republic of China.
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Abstract
Three new phenanthrene derivatives, aristoliukine-C, aristofolin-E and aristolochic acid-Ia methyl ester, and one new sesquiterpene, madolin-P, together with 58 known compounds were isolated from the stem and root of Aristolochia kaempferi. The structures of these compounds were determined by spectral analysis. The cytotoxicity and antiplatelet activity of the isolated compounds are also discussed.
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Affiliation(s)
- T S Wu
- Department of Chemistry, National Cheng Kung University, Tainan. Taiwan, ROC.
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Abstract
Four new compounds, three phenanthrene derivatives, aristolochic acid-III methyl ester (1), cepharanone C (2), and sodium 7-hydroxyl-8-methoxyaristolate (3), and the benzoate derivative, sodium 3,4-dimethoxybenzoate (4), together with 53 known compounds were isolated and characterized from the fresh root and stem of Aristolochia cucurbitifolia. Their structures were elucidated by spectral analyses and chemical transformations. The cytotoxicity and antiplatelet activity of the isolated compounds are also discussed.
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Affiliation(s)
- T S Wu
- Department of Chemisty, National Cheng Kung University, Tainan, Taiwan, ROC.
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Abstract
Seven new compounds, sodium aristolochate-VII (1), aristolactam-CIV (2), madolin-I (3), -J (4), -K (5), -L (6) and -M (7) together with 71 known compounds were isolated and characterized from the fresh root and stem of Aristolochia heterophylla Hemsl. Their structures were determined by spectral methods. Compound 8 was revised as aromadendrane-4beta, 10beta-diol by spectral data and single-crystal X-ray analysis.
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Affiliation(s)
- T S Wu
- Department of Chemistry, National Cheng Kung University, Tainan, Taiwan, ROC
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Abstract
A modified concentric nebulizer was used as the interface to couple capillary electrophoresis (CE) to inductively coupled plasma atomic emission spectrometry (ICP-AES). The CE capillary replaces the central tube of the concentric nebulizer. The tip of the nebulizer tapers slowly to allow uncertainty in the position of the capillary. A platinum wire was inserted into the CE capillary to provide electrical connection to the CE power supply. pH changes inside the capillary due to electrolysis of the background buffer electrolyte was small and has minimal effects on the CE separation. The peak broadening effects due to the nebulizing gas flow, however, were significant. Resolution decreases quickly when the flow-rate of the carrier gas increases. Sample stacking technique was used to improve the resolution of species of opposite charge, e.g., Cr(VI) vs. Cr(III) ions. Detection limit of Cr based on peak area is approximately 10 ppb for the CE-ICP-AES system.
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Affiliation(s)
- Y Y Chan
- Department of Chemistry, University of Hong Kong, Hong Kong
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Wu TS, Chan YY, Leu YL, Chen ZT. Sesquiterpene esters of aristolochic acid from the root and stem of Aristolochia heterophylla. J Nat Prod 1999; 62:415-418. [PMID: 10096848 DOI: 10.1021/np980212y] [Citation(s) in RCA: 5] [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] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Three novel sesquiterpene esters of aristolochic acid, aristoloterpenate-II (2), -III (3), and-IV (4), together with known aristoloterpenate-I (1), were isolated and characterized from the root and stem of Aristolochia heterophylla. Their structures were elucidated by spectroscopic methods. The absolute configuration of these compounds at C-4' was determined as R by circular dichroic studies. These compounds showed cytotoxicity against hepatoma G2, 2, 2, 15 cells.
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Affiliation(s)
- T S Wu
- Department of Chemistry, National Cheng Kung University, Tainan, Taiwan 701, Republic of China.
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Wu TS, Chan YY, Leu YL, Wu PL, Li CY, Mori Y. Four aristolochic acid esters of rearranged ent-elemane sesquiterpenes from aristolochia heterophylla. J Nat Prod 1999; 62:348-351. [PMID: 10075784 DOI: 10.1021/np980354s] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Four aristolochic acid esters of ent-elemane type sesquiterpene having a new carbon skeleton, aristophyllides A (1), B (2), C (3), and D (4), were isolated from the stems and roots of Aristolochia heterophylla. The esters were characterized by NMR and MS methods and included is a study of absolute configurations using the CD exciton chirality method.
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Affiliation(s)
- TS Wu
- Department of Chemistry, National Cheng Kung University, Tainan, Taiwan, R.O.C., and Faculty of Pharmacy, Meijo University, Tempaku-Ku, Nagoya 468-8503, Japan
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Abstract
Reinvestigation of the root of Rhinacanthus nasutus afforded, in addition to rhinacanthin-A to -D reported previously, two new dimethyldihydropyranonaphthoquinone esters (5, 6) and eight new 2-hydroxy-1,4-naphthoquinone esters (7-14) were isolated. The stereochemistry of rhinacanthin-A was determined as the R configuration. Compounds rhinacanthin-G to -N, belong to a class of 2-hydroxy-3-(3-hydroxy-2,2-dimethylpropyl)-1,4-naphthoquinone esters, and so far have been isolated only in this plant. Their biosynthesis is also discussed.
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Affiliation(s)
- T S Wu
- Department of Chemistry, National Cheng Kung University, Tainan, Taiwan, R.O.C
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Lau YL, Chan LC, Chan YY, Ha SY, Yeung CY, Waye JS, Chui DH. Prevalence and genotypes of alpha- and beta-thalassemia carriers in Hong Kong -- implications for population screening. N Engl J Med 1997; 336:1298-301. [PMID: 9113933 DOI: 10.1056/nejm199705013361805] [Citation(s) in RCA: 162] [Impact Index Per Article: 6.0] [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 The thalassemias are common in southern China. We determined the prevalence of heterozygous carriers of these genetic disorders in Hong Kong and assessed the feasibility of a community-based screening program. METHODS An educational and screening program for the thalassemias was carried out in three high schools with a total of 2420 students. Seventy-five percent of the students agreed to undergo screening, which consisted of blood counts, hemoglobin electrophoresis, serum ferritin measurements, and DNA analyses. RESULTS Of the 1800 blood samples tested, 150 (8.3 percent) had microcytosis (mean corpuscular volume, <80 microm3). Ninety students (5.0 percent) were carriers of alpha-thalassemia, of whom 81 (4.5 percent) were carriers of the Southeast Asian type of deletion, in which both alpha-globin genes on the same chromosome 16 are deleted. Sixty-one students (3.4 percent) were carriers of either beta-thalassemia or the mutation coding for hemoglobin E. Six students were carriers of both alpha- and beta-thalassemias. On the basis of these figures, the estimated numbers of pregnancies in Hong Kong in which the fetus is at risk for homozygous alpha-thalassemia and beta-thalassemia major or intermedia are 145 and 80 per year, respectively. In Hong Kong the actual numbers of women referred for prenatal diagnoses of these disorders are approximately 95 and 40 per year, respectively. CONCLUSIONS Despite the availability of hospital-based screening and prenatal diagnosis for many years in Hong Kong, many women carrying fetuses at risk for thalassemia are not referred for genetic counseling. A community-based program of education, screening, and counseling is needed in Hong Kong and southern China.
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Affiliation(s)
- Y L Lau
- Department of Pediatrics, University of Hong Kong and Queen Mary Hospital
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Chan YY, Grafstein-Dunn E, Delemarre-van de Waal HA, Burton KA, Clifton DK, Steiner RA. The role of galanin and its receptor in the feedback regulation of growth hormone secretion. Endocrinology 1996; 137:5303-10. [PMID: 8940350 DOI: 10.1210/endo.137.12.8940350] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
GH controls its own secretion through a mechanism involving short-loop feedback regulation of the synthesis and release of GH-releasing hormone (GHRH). GHRH neurons coexpress the peptide galanin, but the functional significance of this coexpression is unknown. In this study, we tested the hypotheses that 1) galanin gene expression in GHRH neurons is regulated by GH and 2) somatostatin (SS) or GHRH neurons are a target for the action of galanin in the hypothalamus. First, we compared levels of galanin messenger RNA (mRNA) in GHRH neurons between normal male rats and Lewis dwarf rats, which have markedly reduced blood levels of GH. The brains of normal and dwarf animals were processed for detection of galanin mRNA and GHRH mRNA by double-label in situ hybridization. We observed that Lewis dwarf rats had significantly reduced levels of galanin mRNA in their GHRH neurons (P < 0.05). Next, we tested the hypothesis that GH regulates galanin gene expression in GHRH neurons by experimentally altering circulating levels of GH. Three groups of adult male rats were used: 1) intact rats (n = 7); 2) hypophysectomized (hypox) rats (n = 7); and 3) hypox rats treated with 1.5 mg of rat GH (rGH) over a 3-day period (n = 6). At the end of the treatment period, the animals were killed, and their brains were collected and processed for double-label in situ hybridization for GHRH mRNA and galanin mRNA. The signal level of galanin mRNA in GHRH neurons was reduced in hypox animals to less than 10% of that in intact controls (P < 0.0001); whereas, the levels of galanin mRNA signal in GHRH neurons did not differ significantly between the groups of intact and rGH-treated hypox rats. Finally, to determine whether SS or GHRH neurons are targets for galanin, we used double-label in situ hybridization to determine whether either of these populations of neurons express galanin receptor mRNA. A subset of SS neurons in the PeN appeared to express the galanin receptor mRNA, whereas few, if any, GHRH neurons appeared to do so. We conclude that galanin, like its cotransmitter GHRH, is a target for GH action, and we infer that galanin may play a role in the feedback control of GH secretion by exerting a direct effect on SS neurons.
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Affiliation(s)
- Y Y Chan
- Department of Medicine, University of Washington, Seattle 98195, USA
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Shounan Y, Dolnikov A, MacKenzie KL, Miller M, Chan YY, Symonds G. Retroviral transduction of hematopoietic progenitor cells with mutant p53 promotes survival and proliferation, modifies differentiation potential and inhibits apoptosis. Leukemia 1996; 10:1619-28. [PMID: 8847897] [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: 02/02/2023]
Abstract
Mutations in the p53 tumor suppressor gene have been shown to be associated with many human tumors and various leukemias and lymphomas. To examine whether constitutive overexpression of mutant p53 can effect transformation of normal hematopoietic cells, a mutant p53 gene was introduced into normal murine bone marrow hematopoietic cells by retroviral gene transfer. Compared to vector alone-infected cells, hematopoietic progenitor cells transduced with mutant p53 showed increased proliferative potential, enhanced cloning efficiencies and a modified differentiation pattern in vitro. In addition, mutant p53-transduced hematopoietic cells were more resistant to loss of viability and/or induction of apoptosis when cultured in a low concentration of serum or in the absence of both growth factors and serum. These effects occurred rapidly with no apparent contributory secondary events. No permanent cell lines or growth factor-independent cell strains were obtained. The results indicate that introduction of mutant p53 into normal hematopoietic cells in vitro contributes to transformation, including enhanced proliferative potential, modified differentiation and the suppression of apoptosis in these cells.
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Affiliation(s)
- Y Shounan
- RW Johnson Pharmaceutical Research Institute, Sydney, Australia
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Abstract
Twenty-six patients with a total of 45 scars were studied to determine the efficacy of the new silicone sheet, Sil-K, in treating hypertrophic scars. Twenty-eight scars were treated with Sil-K and 17 scars were treated with the conventional gel, Epiderm. Evaluation based on the scar's colour, texture, thickness and regularity was done on a monthly interval for 6 months. Preliminary results suggest that both Sil-K and Epiderm are effective in treating hypertrophic scars. All of the four parameters studied showed improvement, with colour, texture and regularity showing higher percentage of improvement than thickness (90, 90, 80 and 50 per cent respectively). Complications such as rashes, pruitus, maceration and dry skin were reported by some subjects. Epiderm and Sil-K were also compared across factors such as cost, durability, conformity and hygiene to assist therapists in choosing the suitable silicone sheet for each individual patient.
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Affiliation(s)
- S M Lee
- Occupational Therapy Department, Singapore General Hospital, Singapore
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Abstract
GH is thought to exert a short-loop feedback action on the hypothalamic somatostatin- and GH-releasing hormone (GHRH)-containing neurons. The direct actions of GH are mediated through GH receptors. In the male rat, few GHRH-containing neurons in the arcuate nucleus (ARC) appear to express the GH receptor messenger RNA (mRNA); however, some unidentified neurons near GHRH neurons do. Recent evidence suggests that neuropeptide-Y (NPY)-containing neurons, which are located near GHRH neurons in the ARC, are targets for GH action because treatment of rats with GH induces c-fos expression in these cells. We conducted two experiments to test the hypothesis that GH acts on NPY neurons in the ARC. First, we performed double-label in situ hybridization to determine whether NPY neurons in the ARC express GH receptor mRNA. Second, we investigated the possibility that GH regulates NPY mRNA expression by using in situ hybridization to compare ARC NPY mRNA levels among groups of normal (n = 7), hypophysectomized (n = 7), and hypophysectomized/rGH-treated (1.5 mg rat GH over 3 days; n = 6) rats. We found that most of the NPY-containing neurons in the ARC expressed GH receptor mRNA, whereas hypothalamic NPY neurons residing outside of the ARC did not. Furthermore, hypophysectomy significantly decreased NPY mRNA levels, and GH treatment restored the levels to those of the intact animals. We conclude that GH regulates the activity of NPY neurons in the ARC by a direct action on GH receptors that are expressed by NPY neurons. Whether the action of GH on NPY neurons in the ARC is related to the feedback control of GH secretion or some other physiological function remains to be determined.
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Affiliation(s)
- Y Y Chan
- Department of Medicine, University of Washington School of Medicine, Seattle, 98195, USA
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Abstract
The neuroendocrine regulation of pulsatile growth hormone (GH) secretion involves the reciprocal interactions between growth hormone-releasing hormone (GHRH)- and somatostatin-containing neurones, residing primarily in the hypothalamic arcuate nucleus (ARC) and the periventricular nucleus (PeN), respectively. Considerable evidence supports the concept that GH itself participates in the regulation of its own rhythmic secretion through a reciprocal feedback on GHRH and somatostatin neurones. The direct actions of GH are mediated through GH receptors, and in the PeN, the majority of somatostatin neurones express this receptor. GH induces the expression of the immediate early gene c-fos in the ARC; however, few GHRH residing in the ARC express the GH receptor, suggesting that the action of GH on GHRH cells must be indirect through another population of unidentified cells. NPY neurones express c-fos in response to GH, and preliminary results suggest that NPY neurones in the ARC express the GH receptor. These observations suggest that NPY neurones play a physiological role in the feedback of regulation of GH secretion.
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Affiliation(s)
- Y Y Chan
- Department of Obstetrics and Gynecology, University of Washington School of Medicine, Seattle, USA
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Gottscho RA, Mitchell A, Scheller GR, Chan YY, Graves DB. Electric field reversals in dc negative glow discharges. Phys Rev A Gen Phys 1989; 40:6407-6414. [PMID: 9902037 DOI: 10.1103/physreva.40.6407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Abstract
Cognitive schema were used to explain health and illness behaviors among Chinese students. University students in Hong Kong were asked to attribute causes and suggest solutions to five health/mental health problems: Weakness/Fatigue, Tension/Anxiety, Sleep Difficulty, Hollow/Emptiness, and Headache. The patterns of endorsement on the causal and solution categories used for the five problems were compared using a new asymptotic chi-squared test. The response patterns were found to be significantly different across the five problems. Each problem was attributed to multiple causes including psychological, social, situational, somatic, and existential factors. The intended solutions were often related to the nature of the causal attributions especially when the problems were mild. In lay help-seeking, the Hong Kong students would attempt a variety of self-help measures. However, for professional consultation, the medical doctor would be the primary care professional the students would turn to for most of the problems except in the case of Hollow/Emptiness.
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Abstract
During the infection of mice with Listeria monocytogenes, there is a profound depletion of T (Thy-1+ Ig-) lymphocytes between days 1 and 4, followed by an increase in T cells to three times normal levels by day 9. The recovery of T cell numbers required cell proliferation, being sensitive to vinblastin and cyclophosphamide. Adult thymectomy 6 months before infection had no effect on recovery. The repopulating cells were no more sensitive than normal T cells to hydrocortisone. B lymphocytes (Ig+ cells) and null (Thy-1-Ig-) cells increased from day 1 after the injection of either live or (in contrast to T cells) killed Listeria organisms. Their increase was inhibited by vinblastin and cyclophosphamide. Despite T cell depletion, no depression of the antibody response to the T-dependent antigen, sheep erythrocytes, occurred during infection or when spleen cells were adoptively transferred from infected mice to irradiated recipients.
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Abstract
Marked changes in the splenic lymphocyte populations during murine infection with Listeria monocytogenes were observed histologically and quantitated by the immunofluorescence of Thy-1+ immunoglobulin (Ig-) (T) and Ig+ (B) cells. Cells were depleted from the T-dependent areas of the spleen, and the number of T cells in suspensions prepared from spleens of mice 1 to 3 days after primary or secondary infection were less than 1/10 of normal. High numbers of alcohol-killed Listeria sp. did not cause any depletion. Depletion was not prevented by adrenalectomy. Although injected radiolabeled T cells distributed normally between spleen, liver, lymph node, and gut in infected mice, there appeared to be a barrier to their entry into depleted T-dependent areas of the spleen. Evidence for the destruction of T cells, but not of B cells, in the infected mouse spleen was obtained.
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