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Low L, Cheung C, Bennett M, Sinha S. Embryological origin-specific vascular smooth muscle cells in therapeutic revascularisation. Atherosclerosis 2012. [DOI: 10.1016/j.atherosclerosis.2012.10.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Low L, Cheung C, Bennett M, Sinha S. 20 In vivo tracking of human pluripotent stem cell vascular derivatives. BRITISH HEART JOURNAL 2012. [DOI: 10.1136/heartjnl-2012-302951.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Li M, Chen Z, Deng W, He Z, Wang Q, Jiang L, Ma X, Wang Y, Chua SE, Cheung C, McAlonan GM, Sham PC, Collier DA, Gong Q, Li T. Volume increases in putamen associated with positive symptom reduction in previously drug-naive schizophrenia after 6 weeks antipsychotic treatment. Psychol Med 2012; 42:1475-1483. [PMID: 22030695 DOI: 10.1017/s0033291711002157] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
BACKGROUND Brain structure appears to alter after antipsychotic administration, but it is unknown whether these alterations are associated with improvement of psychopathology in patients with schizophrenia. In this study, the authors explore this relationship. METHOD Altogether, 66 first-episode, drug-naive patients with schizophrenia and 23 well-matched healthy controls underwent brain magnetic resonance imaging scans at baseline. All 23 healthy controls and 42 of the patients were rescanned after 6 weeks follow-up. The patients received regular antipsychotic treatment during the 6-week period and their psychopathology was assessed using the Positive and Negative Syndrome Scale (PANSS) at baseline and 6 weeks. The difference in PANSS scores between baseline and 6 weeks was expressed as a ratio of the scores at baseline - 'PANSS reduction ratio'. A modified tensor-based morphometry procedure was applied to analyse longitudinal images. Correlations between regional volume changes, PANSS reduction ratio and antipsychotic drug dosages were explored. RESULTS Compared with healthy controls, there was a significant increase in grey-matter volume of the right putamen in patients after 6 weeks treatment. This volume change was positively correlated with a positive PANSS reduction score but not related to drug dosages. CONCLUSIONS Putaminal volume increased after 6 weeks antipsychotic treatment in first-episode schizophrenia. The increased volume was closely correlated with improved psychopathology, suggesting the putamen might be a biomarker to predict the treatment response in schizophrenia.
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Leung K, Cheung C, Lam W, Yu S, Chua T. OC-0390 COMPARISON OF TWO ATLAS SELECTION STRATEGIES FOR SEGMENTATION OF HEAD AND NECK CT SCANS. Radiother Oncol 2012. [DOI: 10.1016/s0167-8140(12)70729-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Cheung C, Leung K, Lam W, Yu S, Chua T. PO-0846 THE APPLICATION OF SPECTRAL CT IMAGING IN AUTO-CONTOURING OF HEAD AND NECK CASES. Radiother Oncol 2012. [DOI: 10.1016/s0167-8140(12)71179-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Leone A, Aquila I, Vicinanza C, Iaconetti C, Bochicchio A, Ottolenghi S, Indolfi C, Nadal-Ginard B, Ellison GM, Torella D, Mias C, Genet G, Guilbeau-Frugier C, Pathak A, Senard JM, Gales C, Egorova AD, Khedoe PSJ, Goumans MTH, Nauli SM, Ten Dijke P, Poelmann RE, Hierck BP, Miragoli M, Lab MJ, Singh A, Sikkel M, Lyon A, Gorelik J, Cheung C, Bernardo AS, Trotter MW, Pedersen RA, Sinha S, Mioulane M, Foldes G, Harding SE, Reglin B, Secomb TW, Pries AR, Buckingham M, Lescroart F, Meilhac S, Le Garrec JF, Rozmaritsa N, Christ T, Wettwer E, Knaut M, Ravens U, Tokar S, Schobesberger S, Singh A, Wright PT, Miragoli M, Lyon AR, Sikkel M, Harding SE, Gorelik J, Van Mil A, Grundmann S, Goumans MJ, Jaksani S, Doevendans PA, Sluijter JP, Tijsen AJ, Amin AS, Giudicessi JR, Tanck MW, Bezzina CR, Creemers EE, Wilde AM, Ackerman MJ, Pinto YM, Gedicke-Hornung C, Behrens-Gawlik V, Khajetoorians D, Mearini G, Reischmann S, Geertz B, Voit T, Dreyfus P, Eschenhagen T, Carrier L, Duerr GD, Heinemann JC, Wenzel D, Ghanem A, Alferink JC, Zimmer A, Lutz B, Welz A, Fleischmann BK, Dewald O, Sbroggio' M, Bertero A, Giuliano L, Brancaccio M, Tarone G, Meiser M, Kohlhaas M, Chen Y, Csordas G, Dorn G, Maack C, Stapel B, Hoch M, Haghikia A, Fischer P, Maack C, Hilfiker-Kleiner D, Schroen B, Corsten M, Verhesen W, De Windt L, Pinto YM, Zacchigna S, Thum T, Carmeliet P, Papageorgiou A, Heymans S, Lunde IG, Finsen AV, Florholmen G, Skrbic B, Kvaloy H, Jarstadmarken HO, Sjaastad I, Tonnessen T, Carlson CR, Christensen G, Paavola J, Schliffke S, Rossetti S, Kuo I, Yuan S, Sun Z, Harris P, Torres V, Ehrlich B, Robinson P, Adams K, Zhang YH, Casadei B, Watkins H, Redwood C, Seneviratne AN, Cole JE, Goddard ME, Mohri Z, Cross AJ, Krams R, Monaco C, Everaert BR, Van Laere SJ, Hoymans VY, Timmermans JP, Vrints CJ. Oral abstract presentations & Young Investigators Competition. Cardiovasc Res 2012. [DOI: 10.1093/cvr/cvr333] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Cheung C, Bernardo A, Trotter M, Pedersen RA, Sinha S. 11 Generation of developmental origin-specific vascular smooth muscle cells from human embryonic stem cells. BRITISH HEART JOURNAL 2011. [DOI: 10.1136/heartjnl-2011-300920b.11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Wang Q, Deng W, Huang C, Li M, Ma X, Wang Y, Jiang L, Lui S, Huang X, Chua SE, Cheung C, McAlonan GM, Sham PC, Murray RM, Collier DA, Gong Q, Li T. Abnormalities in connectivity of white-matter tracts in patients with familial and non-familial schizophrenia. Psychol Med 2011; 41:1691-1700. [PMID: 21205362 DOI: 10.1017/s0033291710002412] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND Abnormalities in the connectivity of white-matter (WM) tracts in schizophrenia are supported by evidence from post-mortem investigations, functional and structural magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI). The aims of this study were to explore the microstructural changes in first-episode schizophrenia in a Han Chinese population and to investigate whether a family history of psychiatric disorder is related to the severity of WM tract integrity abnormalities in these patients. METHOD T1-weighted MR and DT images were collected in 68 patients with first-episode schizophrenia [22 with a positive family history (PFH) and 46 with a negative family history (NFH)] and 100 healthy controls. Voxel-based analysis was performed and WM integrity was quantified by fractional anisotropy (FA). Cluster- and voxel-level analyses were performed by using two-sample t tests between patients and controls and/or using a full factorial model with one factor and three levels among the three sample groups (patients with PFH or NFH, and controls), as appropriate. RESULTS FA deficits were observed in the patient group, especially in the left temporal lobe and right corpus callosum. This effect was more severe in the non-familial schizophrenia than in the familial schizophrenia subgroup. CONCLUSIONS Overall, these findings support the hypothesis that loss of WM integrity may be an important pathophysiological feature of schizophrenia, with particular implications for brain dysmaturation in non-familial and familial schizophrenia.
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Cheung V, Chiu CPY, Law CW, Cheung C, Hui CLM, Chan KKS, Sham PC, Deng MY, Tai KS, Khong PL, McAlonan GM, Chua SE, Chen E. Positive symptoms and white matter microstructure in never-medicated first episode schizophrenia. Psychol Med 2011; 41:1709-1719. [PMID: 20809999 DOI: 10.1017/s003329171000156x] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
BACKGROUND We investigated cerebral structural connectivity and its relationship to symptoms in never-medicated individuals with first-onset schizophrenia using diffusion tensor imaging (DTI). METHOD We recruited subjects with first episode DSM-IV schizophrenia who had never been exposed to antipsychotic medication (n=34) and age-matched healthy volunteers (n=32). All subjects received DTI and structural magnetic resonance imaging scans. Patients' symptoms were assessed on the Positive and Negative Syndrome Scale. Voxel-based analysis was performed to investigate brain regions where fractional anisotropy (FA) values significantly correlated with symptom scores. RESULTS In patients with first-episode schizophrenia, positive symptoms correlated positively with FA scores in white matter associated with the right frontal lobe, left anterior cingulate gyrus, left superior temporal gyrus, right middle temporal gyrus, right middle cingulate gyrus, and left cuneus. Importantly, FA in each of these regions was lower in patients than controls, but patients with more positive symptoms had FA values closer to controls. We found no significant correlations between FA and negative symptoms. CONCLUSIONS The newly-diagnosed, neuroleptic-naive patients had lower FA scores in the brain compared with controls. There was positive correlation between FA scores and positive symptoms scores in frontotemporal tracts, including left fronto-occipital fasciculus and left inferior longitudinal fasciculus. This implies that white matter dysintegrity is already present in the pre-treatment phase and that FA is likely to decrease after clinical treatment or symptom remission.
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Hawker GA, French MR, Waugh EJ, Gignac MAM, Cheung C, Murray BJ. The multidimensionality of sleep quality and its relationship to fatigue in older adults with painful osteoarthritis. Osteoarthritis Cartilage 2010; 18:1365-71. [PMID: 20708004 DOI: 10.1016/j.joca.2010.08.002] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2010] [Revised: 06/04/2010] [Accepted: 08/02/2010] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To evaluate subjective sleep quality and its relationship to fatigue in older adults with osteoarthritis (OA). METHOD In a community cohort with hip/knee OA, subjective sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI) and fatigue was measured by the Profile of Mood States - Fatigue subscale (POMS-F). Correlates of sleep quality and fatigue were determined by standardized interviews including socio-demographics, OA severity (Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) summary score), comorbidity, depression (Center for Epidemiologic Studies Depression Scale, CES-D), stressful life events, daytime napping, symptoms of restless legs syndrome (RLS) and prior sleep disorder diagnoses. Logistic regression examined correlates of poor sleep (PSQI score>5). Linear regression evaluated the relationship between poor sleep and fatigue, and the effect of napping on this relationship. RESULTS In 613 respondents, mean age was 78 years, 78% were female, 11% had concomitant fibromyalgia, and 26% had 3+ comorbid conditions. Responses indicated moderate OA severity. Seventy percent reported poor sleep; 25% met criteria for RLS and 6.5% reported a diagnosed sleep disorder. Independent correlates of poor sleep were: greater arthritis severity (adjusted odds ratio (OR) per unit increase in WOMAC score=1.03, P<0.0001), 3+ comorbid conditions (adjusted OR=1.88; P=0.03), depressed mood (adjusted OR per unit increase in CES-D score=1.09, P<0.0001), and RLS (adjusted OR=1.87; P=0.02). Controlling for previously reported fatigue correlates, poor sleep was significantly associated with greater fatigue (parameter estimate=1.63, P=0.0003) and napping did not moderate this relationship (P=0.55 for the interaction between napping and poor sleep). CONCLUSIONS Among older people with OA, poor sleep is highly prevalent and significantly linked with fatigue. Identifying the nature of sleep disturbances in OA is important as treatment of sleep disturbances may reduce OA-related fatigue.
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Cheung C, Shuter J. Pneumocystis jirovecii prophylaxis discontinuation based upon total lymphocyte count in HIV-infected adults treated with antiretroviral therapy. Int J STD AIDS 2010; 21:406-9. [DOI: 10.1258/ijsa.2009.009090] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Pneumocystis jirovecii pneumonia (PCP) prophylaxis may be discontinued when CD4 is ≥200 cells/mm3 for three months in response to highly active antiretroviral therapy (HAART). Unlike CD4, the total lymphocyte count (TLC) is inexpensive and widely available in resource-constrained countries. Paired TLC and CD4 values of HIV-infected patients attending an HIV clinic from 1998 to 2005 were analysed by Spearman's correlation. The sensitivity, specificity, positive predictive value, negative predictive value and receiver operating characteristics (ROC) using TLC cut-off points between ≥1400 and ≥2000 cells/mm3 to predict CD4 ≥200 cells/mm3 were calculated. Next, a cohort of patients who had a TLC ≤ 1200 cells/mm3 and subsequently achieved various TLC cut-off points sustained over three months while receiving HAART was identified. Subjects with subsequent CD4 ≥200 cells/mm3 in response to HAART were considered to have negligible risk for PCP. There was significant correlation between TLC and CD4 in 46,250 observations from 4307 individuals ( r = 0.695, P ≤ 0.001). The area under the ROC curve was 0.85 (95% CI = 0.85–0.86). In the historical cohort analysis, 85% and 70% of subjects who achieved TLC ≥ 2000 cells/mm3 and ≥1400, respectively, had a corresponding CD4 ≥ 200 cells/mm3. A sustained rise in TLC in response to HAART may potentially serve as a criterion for discontinuing PCP prophylaxis in resource-constrained countries.
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McAlonan GM, Cheung C, Cheung V, Wong N, Suckling J, Chua SE. Differential effects on white-matter systems in high-functioning autism and Asperger's syndrome. Psychol Med 2009; 39:1885-1893. [PMID: 19356262 DOI: 10.1017/s0033291709005728] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND Whether autism spectrum maps onto a spectrum of brain abnormalities and whether Asperger's syndrome (ASP) is distinct from high-functioning autism (HFA) are debated. White-matter maldevelopment is associated with autism and disconnectivity theories of autism are compelling. However, it is unknown whether children with ASP and HFA have distinct white-matter abnormalities. METHOD Voxel-based morphometry mapped white-matter volumes across the whole brain in 91 children. Thirty-six had autism spectrum disorder. A history of delay in phrase speech defined half with HFA; those without delay formed the ASP group. The rest were typically developing children, balanced for age, IQ, gender, maternal language and ethnicity. White-matter volumes in HFA and ASP were compared and each contrasted with controls. RESULTS White-matter volumes around the basal ganglia were higher in the HFA group than ASP and higher in both autism groups than controls. Compared with controls, children with HFA had less frontal and corpus callosal white matter in the left hemisphere; those with ASP had less frontal and corpus callosal white matter in the right hemisphere with more white matter in the left parietal lobe. CONCLUSIONS HFA involved mainly left hemisphere white-matter systems; ASP affected predominantly right hemisphere white-matter systems. The impact of HFA on basal ganglia white matter was greater than ASP. This implies that aetiological factors and management options for autism spectrum disorders may be distinct. History of language acquisition is a potentially valuable marker to refine our search for causes and treatments in autism spectrum.
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Cheung C, Chua SE, Cheung V, Khong PL, Tai KS, Wong TKW, Ho TP, McAlonan GM. White matter fractional anisotrophy differences and correlates of diagnostic symptoms in autism. J Child Psychol Psychiatry 2009; 50:1102-12. [PMID: 19490309 DOI: 10.1111/j.1469-7610.2009.02086.x] [Citation(s) in RCA: 127] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND Individuals with autism have impairments in 3 domains: communication, social interaction and repetitive behaviours. Our previous work suggested early structural and connectivity abnormalities in prefrontal-striato-temporal-cerebellar networks but it is not clear how these are linked to diagnostic indices. METHOD Children with autism (IQ > 70) aged 6 to 14 years old and matched typically developing controls were studied using diffusion tensor imaging. Voxel-based methods were used to compare fractional anisotrophy (FA) measures in each group and to correlate FA measures in the autism group with the diagnostic phenotype described by the Autism Diagnostic Interview - Revised (ADI-R) algorithm for ICD-10. RESULTS After controlling for the effects of age and white matter volume, we found that FA in the autism group was significantly lower than controls in bilateral prefrontal and temporal regions, especially in the right ventral temporal lobe adjacent to the fusiform gyrus. FA was greater in autism in the right inferior frontal gyrus and left occipital lobe. We observed a tight correlation between lower FA and higher ADI-R diagnostic algorithm scores across white matter tracts extending from these focal regions of group difference. Communication and social reciprocity impairments correlated with lower FA throughout fronto-striato-temporal pathways. Repetitive behaviours correlated with white matter indices in more posterior brain pathways, including splenium of the corpus callosum and cerebellum. CONCLUSIONS Our data support the position that diagnostic symptoms of autism are associated with a core disruption of white matter development.
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McAlonan GM, Cheung V, Wong NK, Cheung C, Chua SE. Age-related differences in grey matter of children with high function autism and Asperger's syndrome. Neuroimage 2009. [DOI: 10.1016/s1053-8119(09)70050-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Bedikian AY, Sato T, Kim KB, Papadopoulos NE, Hwu W, Homsi J, Davies M, Cheung C, Imperiale SM, Prasad P, Hwu P. Phase II study of vincristine sulfate liposomes injection in patients with metastatic uveal melanoma. J Clin Oncol 2009. [DOI: 10.1200/jco.2009.27.15_suppl.9067] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
9067 Background: Preclinical and clinical studies showed that liposomal encapsulation of vincristine sulfate (VCR) results in increased drug circulation time and accumulation of VCR at the tumor site. Marqibo has been administered safely at 2.25 mg/m2, a dose exceeding that typically employed for VCR ( dose capped at 2 mg), with tolerable clinical toxicities consistent with VCR. Of the 27 previously treated patients with metastatic melanoma in the Marqibo pharmacokinetic studies, 3 patients had a tumor response, including one patient with uveal melanoma metastatic to the lung that experienced a complete response. Methods: Patients with metastatic uveal melanoma with no more than one prior systemic therapy were enrolled. Patients with controlled brain metastases were allowed. Marqibo (2.25 mg/m2 by 1-hour intravenous infusion, no dose capping) was administered every 14 days until tumor progression. Responses were assessed every 6 weeks using the Response Evaluation Criteria in Solid Tumors (RECIST). Toxicity was assessed at least as frequently as before each dose. Results: Preliminary data is available for 22 enrolled patients (73% female). Median age was 65 years (range 38–79), 23% were previously treated with systemic chemotherapy, 86% had liver metastasis and 96% had M1c disease. Baseline serum LDH levels were elevated in 73% and were more than 2 × ULN in 37% of the patients. Twenty-one patients were evaluable for response; one patient discontinued the treatment after a single dose of therapy for toxicity without tumor progression. No patients died of drug toxicity while on the study. Twelve patients (57%) had stable disease. Estimated median survival is 6.4 months. Fourteen patients are alive, 2 for more than 12 months. Treatment related side effects were mostly grade 1 or 2; peripheral neuropathy was the only grade 3 toxicity, seen in 18% of the patients. The hematologic toxicities were minor; no neutropenia or thrombocytopenia was seen. Conclusions: Marqibo is well tolerated as single agent therapy in patients with advanced stage IV uveal melanoma. Its impact on the progression-free and overall survival of these critically ill patients will be presented. No significant financial relationships to disclose.
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Chua SE, Deng Y, Chen EYH, Law CW, Chiu CPY, Cheung C, Wong JCH, Lienenkaëmper N, Cheung V, Suckling J, McAlonan GM. Early striatal hypertrophy in first-episode psychosis within 3 weeks of initiating antipsychotic drug treatment. Psychol Med 2009; 39:793-800. [PMID: 18713487 DOI: 10.1017/s0033291708004212] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND We and others have reported that patients experiencing their first episode of psychosis already have significant structural brain abnormalities. Antipsychotics seem to reverse subcortical volume deficits after months of treatment. However, the early impact of medication on brain morphology is not known. METHOD Forty-eight individuals in their first episode of psychosis underwent magnetic resonance imaging (MRI) brain scanning. Twenty-six were antipsychotic naive and 22 were newly treated with antipsychotic medication for a median period of 3 weeks. In each group, 80% of subjects received a diagnosis of schizophrenia. The two groups were balanced for age, sex, handedness, ethnicity, height, years of education, paternal socio-economic status (SES) and Positive and Negative Syndrome Scale (PANSS) score. Group differences in whole-brain grey matter were compared voxel by voxel, using Brain Activation and Morphological Mapping (BAMM) software. We also conducted testing of group differences with region-of-interest (ROI) measurements of the caudate nucleus. RESULTS Relative to the untreated group, those receiving antipsychotic medication for 3-4 weeks had significantly greater grey-matter volumes in the bilateral caudate and cingulate gyri, extending to the left medial frontal gyrus. ROI analysis confirmed that, in treated patients, the right and left caudate nuclei were significantly larger by 10% (p<0.039, two-tailed) and 9% (p<0.048, two-tailed) respectively. CONCLUSIONS Early striatal grey-matter enlargement may occur within the first 3-4 weeks of antipsychotic treatment. Possible reasons for putative striatal hypertrophy and its implications are discussed.
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Syyong HT, Yang HHC, Trinh G, Cheung C, Kuo KH, van Breemen C. Mechanism of asynchronous Ca(2+) waves underlying agonist-induced contraction in the rat basilar artery. Br J Pharmacol 2009; 156:587-600. [PMID: 19154440 DOI: 10.1111/j.1476-5381.2008.00063.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND AND PURPOSE Uridine 5'-triphosphate (UTP) is a potent vasoconstrictor of cerebral arteries and induces Ca(2+) waves in vascular smooth muscle cells (VSMCs). This study aimed to determine the mechanisms underlying UTP-induced Ca(2+) waves in VSMCs of the rat basilar artery. EXPERIMENTAL APPROACH Isometric force and intracellular Ca(2+) ([Ca(2+)](i)) were measured in endothelium-denuded rat basilar artery using wire myography and confocal microscopy respectively. KEY RESULTS Uridine 5'-triphosphate (0.1-1000 micromol.L(-1)) concentration-dependently induced tonic contraction (pEC(50) = 4.34 +/- 0.13), associated with sustained repetitive oscillations in [Ca(2+)](i) propagating along the length of the VSMCs as asynchronized Ca(2+) waves. Inhibition of Ca(2+) reuptake in sarcoplasmic reticulum (SR) by cyclopiazonic acid abolished the Ca(2+) waves and resulted in a dramatic drop in tonic contraction. Nifedipine reduced the frequency of Ca(2+) waves by 40% and tonic contraction by 52%, and the nifedipine-insensitive component was abolished by SKF-96365, an inhibitor of receptor- and store-operated channels, and KB-R7943, an inhibitor of reverse-mode Na(+)/Ca(2+) exchange. Ongoing Ca(2+) waves and tonic contraction were also abolished after blockade of inositol-1,4,5-triphosphate-sensitive receptors by 2-aminoethoxydiphenylborate, but not by high concentrations of ryanodine or tetracaine. However, depletion of ryanodine-sensitive SR Ca(2+) stores prior to UTP stimulation prevented Ca(2+) waves. CONCLUSIONS AND IMPLICATIONS Uridine 5'-triphosphate-induced Ca(2+) waves may underlie tonic contraction and appear to be produced by repetitive cycles of regenerative Ca(2+) release from the SR through inositol-1,4,5-triphosphate-sensitive receptors. Maintenance of Ca(2+) waves requires SR Ca(2+) reuptake from Ca(2+) entry across the plasma membrane via L-type Ca(2+) channels, receptor- and store-operated channels, and reverse-mode Na(+)/Ca(2+) exchange.
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Cheung V, Cheung C, McAlonan GM, Deng Y, Wong JG, Yip L, Tai KS, Khong PL, Sham P, Chua SE. A diffusion tensor imaging study of structural dysconnectivity in never-medicated, first-episode schizophrenia. Psychol Med 2008; 38:877-885. [PMID: 17949516 DOI: 10.1017/s0033291707001808] [Citation(s) in RCA: 157] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
BACKGROUND Diffusion tensor imaging (DTI) can be used to investigate cerebral structural connectivity in never-medicated individuals with first-episode schizophrenia. METHOD Subjects with first-episode schizophrenia according to DSM-IV-R who had never been exposed to antipsychotic medication (n=25) and healthy controls (n=26) were recruited. Groups were matched for age, gender, best parental socio-economic status and ethnicity. All subjects underwent DTI and structural magnetic resonance imaging (MRI) scans. Voxel-based analysis was performed to investigate brain regions where fractional anisotropy (FA) values differed significantly between groups. A confirmatory region-of-interest (ROI) analysis of FA scores was performed in which regions were placed blind to group membership. RESULTS In patients, FA values significantly lower than those in healthy controls were located in the left fronto-occipital fasciculus, left inferior longitudinal fasciculus, white matter adjacent to right precuneus, splenium of corpus callosum, right posterior limb of internal capsule, white matter adjacent to right substantia nigra, and left cerebral peduncle. ROI analysis of the corpus callosum confirmed that the patient group had significantly lower mean FA values than the controls in the splenium but not in the genu. The intra-class correlation coefficient (ICC) for independent ROI measurements was 0.90 (genu) and 0.90 (splenium). There were no regions where FA values were significantly higher in the patients than in the healthy controls. CONCLUSIONS Widespread structural dysconnectivity, including the subcortical region, is already present in neuroleptic-naive patients in their first episode of illness.
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Hoffman AS, Stayton PS, El-Sayed MEH, Murthy N, Bulmus V, Lackey C, Cheung C. Design of "Smart" Nano-Scale Delivery Systems for Biomolecular Therapeutics. J Biomed Nanotechnol 2007. [DOI: 10.1166/jbn.2007.031] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Cheung C, Guo Y, Gialanella P, Feldmesser M. Development of candidemia on caspofungin therapy: a case report. Infection 2007; 34:345-8. [PMID: 17180591 DOI: 10.1007/s15010-006-5613-7] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2005] [Accepted: 02/20/2006] [Indexed: 11/28/2022]
Abstract
Caspofungin, an echinocandin, is approved for use in invasive candidiasis. Few cases of break-through candidal infections during caspofungin therapy have been reported and none have involved Candida parapsilosis. Here, we report a patient who developed multiple post-operative complications after pancreaticoduodenectomy for a pancreatic mass, including fungemia due to C. parapsilosis, while on caspofungin for treatment of Candida glabrata peritonitis. The fungemia resolved after a central venous catheter was removed and therapy was switched from caspofungin to amphotericin B lipid complex. Studies of C. parapsilosis susceptibility and the pharmacodynamics and drug interactions of caspofungin that may contribute to breakthrough fungemia are discussed.
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Maher JM, Slitt AL, Callaghan TN, Cheng X, Cheung C, Gonzalez FJ, Klaassen CD. Alterations in transporter expression in liver, kidney, and duodenum after targeted disruption of the transcription factor HNF1alpha. Biochem Pharmacol 2006; 72:512-22. [PMID: 16806085 DOI: 10.1016/j.bcp.2006.03.016] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2006] [Revised: 03/18/2006] [Accepted: 03/20/2006] [Indexed: 10/24/2022]
Abstract
The transcription factor hepatocyte nuclear factor 1alpha (HNF1alpha) is involved in regulation of glucose metabolism and transport, and in the expression of several drug and bile acid metabolizing enzymes. Targeted disruption of the HNF1alpha gene results in decreased Cyp1a2, and Cyp2e1 expression, and increased Cyp4a1 and Cyp7a1 expression, suggesting these enzymes are HNF1alpha target genes. Since hepatic metabolism can be coordinately linked with drug and metabolite transport, this study aims to demonstrate whether HNF1alpha regulates expression of a variety of organic anion and cation transporters through utilization of an HNF1alpha-null mouse model. Expression of 32 transporters, including members of the Oat, Oatp, Oct, Mrp, Mdr, bile acid and sterolin families, was quantified in three different tissues: liver, kidney, and duodenum. The expression of 17 of 32 transporters was altered in liver, 21 of 32 in kidney, and 6 of 32 in duodenum of HNF1alpha-null mice. This includes many novel observations, including marked downregulation of Oats in kidney, as well as upregulation of many Mrp and Mdr family members in all three tissues. These data indicate that disruption of HNF1alpha causes a marked attenuation of several Oat and Oatp uptake transporters in liver and kidney, and increased expression of efflux transporters such as Mdrs and Mrps, thus suggesting that HNF1alpha is a central mediator in regulating hepatic, renal, and intestinal transporters.
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Houghton P, Patel N, Jurzysta M, Biely Z, Cheung C. Antidermatophyte activity of medicago extracts and contained saponins and their structure-activity relationships. Phytother Res 2006; 20:1061-6. [PMID: 17006971 DOI: 10.1002/ptr.1995] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Saponin-rich extracts of Medicago sativa L. have been shown to display antifungal activity against a range of common fungibut only a few individual saponins have been tested against dermatophytes. Total saponins were separately obtained from roots and aerial parts of Medicago sativa, M. murex, M. arabica and M. hybrida. Nineteen saponins and three parent triterpenoids, were tested against three dermatophytic fungi Microsporum gypseum, Trichophyton interdigitale and T. tonsurans using mircowell plate serial dilution assay to determine the Minimum Inhibitory Concentration (MIC). Miconazole was used as a positive control. T. tonsurans appeared to be the most sensitive of the dermatophytes to the active compounds. Aglycones showed less antifungal effect than the glycosides, which displayed a range of activities. Monodesmosidic glycosides of medicagenic acid were the most active compounds, especially the 3-O-beta-D-glucopyranoside, which displayed MIC less than 0.09mm against all three fungi, although those of hederagenin and zanhic acid also showed weak activity (MIC 3.3mm against two fungal species). Bidesmosidic saponins had weaker activity than monodesmosidic ones. This corresponds to activity of these and similar compounds against other fungal species but this is the first comprehensive report of activity of Medicago saponins against dermatophytes.
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Hegarty J, Middleton RJ, Krebs M, Hussain H, Cheung C, Ledson T, Hutchison AJ, Kalra PA, Rayner HC, Stevens PE, O'Donoghue DJ. Severe acute renal failure in adults: place of care, incidence and outcomes. QJM 2005; 98:661-6. [PMID: 16055475 DOI: 10.1093/qjmed/hci109] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Department of Health guidelines recommend specialist critical care facilities for patients with severe single-organ failure such as acute renal failure (ARF). Prospective studies examining incidence, causes and outcomes of ARF outside of intensive care settings are lacking. AIM To determine the incidence, causes, place of care and outcomes of severe single-organ ARF. DESIGN Prospective observational study. METHODS For 6 weeks in June-July 2003, renal physicians were contacted daily, and ICUs on alternate days, to identify cases of severe single-organ ARF in the Greater Manchester area. All patients with serum creatinine >or=500 micromol/l and not requiring other organ support were included. Patients with end-stage renal disease were excluded. Survivors were followed up at 90 days and 1 year from admission. Two independent consultant nephrologists assessed each case using anonymized summaries. RESULTS Eighty-five patients had multi-organ ARF and 28 had severe single-organ ARF (380 and 125 pmp/year, respectively). Of those with single-organ ARF, 10 (36%) had known pre-existing chronic kidney disease. Renal replacement therapy (RRT) was required in 15 (54%). Total bed occupancy on ICUs relating to single-organ ARF was 59 days (range per patient 1-21). At 90 days, 18 (64%) were alive, and 17 (94%) had independent renal function. At 1 year, 4/18 had died, none receiving RRT at the time of death. Survivors all had independent renal function. In 13 (46%) cases there was an unacceptable delay in patient transfer and in 7 (25%), delays in assessment or commencement of RRT may have adversely affected patient outcome. DISCUSSION The incidence of ARF treated with RRT is rising. Delays in transfer to renal services may result in inappropriate ICU bed use, and may adversely affect patient outcomes. There are serious problems regarding the appropriate use of expensive and limited medical resources in the critical care area, and in providing safe and effective treatment of patients with ARF.
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Stayton PS, El-Sayed MEH, Murthy N, Bulmus V, Lackey C, Cheung C, Hoffman AS. 'Smart' delivery systems for biomolecular therapeutics. Orthod Craniofac Res 2005; 8:219-25. [PMID: 16022724 DOI: 10.1111/j.1601-6343.2005.00336.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE There is a strong need for drug delivery systems that can deliver biological signals from biomaterials and tissue engineering scaffolds, and a particular need for new delivery systems that can efficiently deliver biomolecules to intracellular targets. Viruses and pathogens have evolved potent molecular machinery that sense the lowered pH gradient of the endosomal compartment and become activated to destabilize the endosomal membrane, thereby enhancing protein or DNA transport to the cytoplasmic compartment. A key feature of many of these biological delivery systems is that they are reversible, so that the delivery systems are not directly toxic. These delivery systems have the ability to change their structural and functional properties and thus display remarkable 'smart' material properties. The objective of this presentation is to review the initial development of smart polymeric carriers that mimic these biological delivery systems and combine similar pH-sensitive, membrane-destabilizing activity for the delivery of therapeutic biomolecules. DESIGN We have developed new 'smart' polymeric carriers to more effectively deliver and broaden the available types of biomolecular therapeutics. The polymers are hydrophilic and stealth-like at physiological pH, but become membrane-destabilizing after uptake into the endosomal compartment where they enhance the release of therapeutic cargo into the cytoplasm. They can be designed to provide a range of pH profiles and membrane-destabilizing activities, allowing their molecular properties to be matched to specific drugs and loading ranges. A versatile set of linker chemistries is available to provide degradable conjugation sites for proteins, nucleic acids, and/or targeting moieties. RESULTS The physical properties of several pH-responsive polymers were examined. The activity and pH profile can be manipulated by controlling the length of hydrophobic alkyl segments. The delivery of poly(propyl acrylic acid) (PPAA)-containing lipoplexes significantly enhanced wound healing through the interconnected effects of altered extracellular matrix organization and greater vascularization. PPAA has also been shown to enhance cytoplasmic delivery of a model protein therapeutic. Polymeric carriers displaying pH-sensitive, membrane-destabilizing activity were also examined. The pH profile is controlled by the choice of the alkylacrylic acid monomer and by the ratio of the carboxylate-containing alkylacrylic acid monomer to alkylacrylate monomer. The membrane destabilizing activity is controlled by the lengths of the alkyl segment on the alkylacrylic acid monomer and the alkylacrylate monomer, as well as by their ratio in the final polymer chains. CONCLUSION The molecular mechanisms that proteins use to sense and destabilize provide interesting paradigms for the development of new polymeric delivery systems that mimic biological strategies for promoting the intracellular delivery of biomolecular drugs. The key feature of these polymers is their ability to directly enhance the intracellular delivery of proteins and DNA, by destabilizing biological membranes in response to vesicular compartment pH changes. The ability to deliver a wide variety of protein and nucleic acid drugs to intracellular compartments from tissue engineering and regenerative scaffolds could greatly enhance control of important processes such as inflammation, angiogenesis, and biomineralization.
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Doherty DR, Sutcliffe IT, Shih J, Stanimirovic D, Suppes R, Gulati H, Halmarson E, Selaman M, Dellinger P, Kramer A, Roberts D, Kumar A, Ronald J, Gray M, Nenadovic V, Perez-Velazquez JL, Pang E, Barnes M, Otsubo H, Hutchison JS, Cheung C, Alibhai SMH, Robinson M, Chittock D, Drover J, Skrobik Y, Skrobik Y, Alibhai S, Grant EC, Menon K, Kusum M, Clinton TB, Jacka, Jacka M, Vera N. In collaboration with the canadian critical care society, the canadian journal of Anesthesia is proud to publish the best posters presented at the Toronto critical care medicine symposium 2004 (adult and pediatric) held in Toronto, Ontario, october 21-october 23, 2004. Can J Anaesth 2005. [DOI: 10.1007/bf03016303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Kontopoulou M, Wang W, Gopakumar T, Cheung C. Effect of composition and comonomer type on the rheology, morphology and properties of ethylene-α-olefin copolymer/polypropylene blends. POLYMER 2003. [DOI: 10.1016/j.polymer.2003.08.043] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Chua SE, Lam IWS, Tai KS, Cheung C, Tang WN, Chen EYH, Lee PWH, Chan FL, Lieh-Mak F, McKenna PJ. Brain morphological abnormality in schizophrenia is independent of country of origin. Acta Psychiatr Scand 2003; 108:269-75. [PMID: 12956827 DOI: 10.1034/j.1600-0447.2003.00134.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVE The disorder schizophrenia has a worldwide prevalence of 1% and is generally associated with lateral cerebral ventricular enlargement. Whether there is a relationship between these two findings is unclear but has aetiological relevance. METHOD Consecutively admitted Chinese patients (n = 19) with first episode of schizophrenia and healthy community volunteers (n = 29) underwent magnetic resonance imaging brain scan. The groups were balanced for age, sex, best social class and handedness. These patients were similar on clinical and socio-demographic indices to those who declined participation (n = 15). Semi-automated volumetric analysis of whole brain volume, cortical grey matter, cerebrospinal fluid, sulci and lateral ventricles was performed. RESULTS Chinese patients in their first episode of schizophrenia have significant enlargement of lateral ventricles. CONCLUSION Brain morphological abnormality in schizophrenia is present regardless of the country of origin. The importance of genes in driving normal brain development and stable prevalence suggests that aetiology may favour genes over environment.
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Jain A, Bolton R, Abd-El-Barr M, Cheung C. On multiple-valued logic design of neural networks. PROCEEDINGS OF 36TH MIDWEST SYMPOSIUM ON CIRCUITS AND SYSTEMS 2002. [DOI: 10.1109/mwscas.1993.343395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
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Hutley LJ, Herington AC, Shurety W, Cheung C, Vesey DA, Cameron DP, Prins JB. Human adipose tissue endothelial cells promote preadipocyte proliferation. Am J Physiol Endocrinol Metab 2001; 281:E1037-44. [PMID: 11595661 DOI: 10.1152/ajpendo.2001.281.5.e1037] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Adipogenesis is preceded by development of a microvascular network, and optimal functioning of adipose tissue as an energy store and endocrine organ is dependent on extensive vascularization. We have examined the role of endothelial cell-derived factors that influence the proliferation of human preadipocytes. Microvascular endothelial cells and preadipocytes were isolated from human omental and subcutaneous adipose tissue biopsies by use of a developed procedure of collagenase digest, immunoselection, and differential trypsinization. Conditioned medium from microvascular endothelial cell cultures promoted the proliferation of preadipocytes (P = <0.001) and (to a lesser extent) other cell types. No depot-specific differences in mitogenic capacity of microvascular endothelial cell medium or of preadipocyte response were observed. These results indicate that adipose tissue endothelial cells secrete soluble adipogenic factor(s).
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Cheung C, Culver JP, Takahashi K, Greenberg JH, Yodh AG. In vivo cerebrovascular measurement combining diffuse near-infrared absorption and correlation spectroscopies. Phys Med Biol 2001; 46:2053-65. [PMID: 11512610 DOI: 10.1088/0031-9155/46/8/302] [Citation(s) in RCA: 155] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
We combine two near-infrared diffuse optical techniques to study variations of blood flow, haemoglobin concentration, and blood oxygen saturation in the functioning rat brain. Diffuse correlation spectroscopy (or flowmetry) monitors changes in the cerebral blood flow, without the use of the principles of tracer clearance, by measuring the optical phase-shifts caused by moving blood cells. Near-infrared absorption spectroscopy concurrently measures tissue absorption at two wavelengths to determine haemoglobin concentration and blood oxygen saturation in this same tissue volume. This optical probe is non-invasive and was employed through the intact skull. The utility of the technique is demonstrated in vivo by measuring the temporal changes in the regional vascular dynamics of rat brain during hypercapnia. Temporal and spatial variations of cerebral blood flow, haemoglobin concentration and blood oxygen saturation during hypercapnia are compared with other measurements in the literature, and a quantitative analysis demonstrating the self-consistency of our combined observations of vascular response is presented.
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Smith CK, Cheung C, Elahi EN, Hotchkiss SA. High-performance liquid chromatography method for the quantification of non-radiolabelled cinnamic compounds in analytes derived from human skin absorption and metabolism experiments. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 2001; 758:249-64. [PMID: 11486835 DOI: 10.1016/s0378-4347(01)00184-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An isocratic high-performance liquid chromatography method has been developed for the quantification of the skin sensitisers trans-cinnamaldehyde and trans-cinnamic alcohol, and their cinnamic metabolites. The relative standard deviations (RSDs) between the gradients of eight sets of standard curves were 2.8, 3.1 and 1.9% for cinnamic alcohol, cinnamaldehyde and cinnamic acid, respectively. Sample analytes were derived from two series of experiments: in vitro full-thickness human skin absorption and metabolism studies and metabolism studies using human skin homogenates, with non-radiolabelled cinnamic compounds. Skin absorption and metabolism experiments were performed in the absence and presence of the alcohol dehydrogenase inhibitor, pyrazole. Samples from full-thickness skin absorption studies were analysed without extraction; cinnamic compounds from within skin were extracted into methanolic solutions using newly developed methods. The intra-assay RSDs ranged from 0.17 to 2.52% for cinnamic alcohol, 0.24 to 9.14% for cinnamaldehyde and 0.26 to 6.43% for cinnamic acid. The inter-assay RSDs for cinnamic alcohol, cinnamaldehyde and cinnamic acid, respectively, as determined from n=20 HPLC runs, were 2.10, 4.16 and 2.26%.
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Cheung NT, Fung KW, Wong KC, Cheung A, Cheung J, Ho W, Cheung C, Shung E, Fung V, Fung H. Medical informatics--the state of the art in the Hospital Authority. Int J Med Inform 2001; 62:113-9. [PMID: 11470614 DOI: 10.1016/s1386-5056(01)00155-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Since its inception in 1990, the Hospital Authority (HA) has strongly supported the development and implementation of information systems both to improve the delivery of care and to make better information available to managers. This paper summarizes the progress to date and discusses current and future developments. Following the first two phases of the HA information technology strategy the basic infrastructural elements were laid in place. These included the foundation administrative and financial systems and databases; establishment of a wide area network linking all hospitals and clinics together; laboratory, radiology and pharmacy systems with access to results in the ward. A major push into clinical systems began in 1994 with the clinical management system (CMS), which established a clinical workstation for use in both ward and ambulatory settings. The CMS is now running at all major hospitals, and provides single logon access to almost all the electronically collected clinical data in the HA. The next phase of development is focussed on further support for clinical activities in the CMS. Key elements include the longitudinal electronic patient record (ePR), clinical order entry, generic support for clinical reports, broadening the scope to include allied health and the rehabilitative phase, clinical decision support, an improved clinical documentation framework, sharing of clinical information with other health care providers and a comprehensive data repository for analysis and reporting purposes.
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Rahman P, Nguyen E, Cheung C, Schentag CT, Gladman DD. Comparison of radiological severity in psoriatic arthritis and rheumatoid arthritis. J Rheumatol 2001; 28:1041-4. [PMID: 11361186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
Abstract
OBJECTIVE To compare the radiological severity of patients with psoriatic arthritis (PsA) and rheumatoid arthritis (RA). METHODS Patients were identified from the University of Toronto PsA and RA databases. Using the earliest available radiographs, each RA patient was matched to a single PsA patient on the basis of sex, age, and disease duration. Two rheumatologists blinded to the patient's diagnosis scored the radiographs using the modified Steinbrocker method. RESULTS PsA and RA groups were similar with respect to demographics as well as the use of disease modifying antirheumatic medications. No significant difference in Steinbrocker score for the hands and feet or the hands only was noted. Patients with RA had a higher radiological score in the feet. The 2 groups were similar in the number of joints with significant radiological damage (Steinbrocker 3 and 4). CONCLUSION; Overall the radiological severity in the hands and feet of patients with PsA was comparable to that of patients with RA.
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Oh HS, Costello C, Cheung C, Kung H, Kung M. Regeneration of Au/γ -Al2O3 Deactivated by CO Oxidation. ACTA ACUST UNITED AC 2001. [DOI: 10.1016/s0167-2991(01)80220-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2023]
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85
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Hoffman AS, Stayton PS, Bulmus V, Chen G, Chen J, Cheung C, Chilkoti A, Ding Z, Dong L, Fong R, Lackey CA, Long CJ, Miura M, Morris JE, Murthy N, Nabeshima Y, Park TG, Press OW, Shimoboji T, Shoemaker S, Yang HJ, Monji N, Nowinski RC, Cole CA, Priest JH, Harris JM, Nakamae K, Nishino T, Miyata T. Founder's Award, Society for Biomaterials. Sixth World Biomaterials Congress 2000, Kamuela, HI,May 15-20, 2000. Really smart bioconjugates of smart polymers and receptor proteins. JOURNAL OF BIOMEDICAL MATERIALS RESEARCH 2000; 52:577-86. [PMID: 11033539 DOI: 10.1002/1097-4636(20001215)52:4<577::aid-jbm1>3.0.co;2-5] [Citation(s) in RCA: 281] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Over the past 18 years we have been deeply involved with the synthesis and applications of stimuli-responsive polymer systems, especially polymer-biomolecule conjugates. This article summarizes our work with one of these conjugate systems, specifically polymer-protein conjugates. We include conjugates prepared by random polymer conjugation to lysine amino groups, and also those prepared by site-specific conjugation of the polymer to specific amino acid sites that are genetically engineered into the known amino acid sequence of the protein. We describe the preparation and properties of thermally sensitive random conjugates to enzymes and several affinity recognition proteins. We have also prepared site-specific conjugates to streptavidin with temperature-sensitive polymers, pH-sensitive polymers, and light-sensitive polymers. The preparation of these conjugates and their many fascinating applications are reviewed in this article.
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86
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Lee T, Cheung C, Chan C, Yip J, Cheung P, Chan C. Trail making across languages. Arch Clin Neuropsychol 2000. [DOI: 10.1093/arclin/15.8.702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Stayton PS, Hoffman AS, Murthy N, Lackey C, Cheung C, Tan P, Klumb LA, Chilkoti A, Wilbur FS, Press OW. Molecular engineering of proteins and polymers for targeting and intracellular delivery of therapeutics. J Control Release 2000; 65:203-20. [PMID: 10699281 DOI: 10.1016/s0168-3659(99)00236-9] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
There are many protein and DNA based therapeutics under development in the biotechnology and pharmaceutical industries. Key delivery challenges remain before many of these biomolecular therapeutics reach the clinic. Two important barriers are the effective targeting of drugs to specific tissues and cells and the subsequent intracellular delivery to appropriate cellular compartments. In this review, we summarize protein engineering work aimed at improving the stability and refolding efficiency of antibody fragments used in targeting, and at constructing new streptavidin variants which may offer improved performance in pre-targeting delivery strategies. In addition, we review recent work with pH-responsive polymers that mimic the membrane disruptive properties of viruses and toxins. These polymers could serve as alternatives to fusogenic peptides in gene therapy formulations and to enhance the intracellular delivery of protein therapeutics that function in the cytoplasm.
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Abstract
A case of pleural lymphoma that developed after an episode of empyema is described. This may be a variant presentation of the rare yet distinct condition termed pyothorax-associated lymphoma. This condition was first recognised in Japan; there have been only a few reports in Western countries to date. A feature of this case is the relatively short interval between diagnosis of empyema and subsequent development of lymphoma.
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Cheung C, Smith CK, Hoog JO, Hotchkiss SA. Expression and localization of human alcohol and aldehyde dehydrogenase enzymes in skin. Biochem Biophys Res Commun 1999; 261:100-7. [PMID: 10405330 DOI: 10.1006/bbrc.1999.0943] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Alcohol dehydrogenase (ADH; EC 1.1.1.1) and aldehyde dehydrogenase (ALDH; EC 1.2.1.3.) are important enzymes involved in the biotransformation of both alcohols and aldehydes. Today, six classes of ADH and twelve classes of ALDH have been defined in mammals. Here we report the detection and localisation of three classes of ADH and two classes of ALDH in human skin, using Western blot analysis and immunohistochemistry with class-specific antisera. Western blot analysis of human skin cytosol revealed that class I-III ADH and class 1 and class 3 ALDH enzymes are expressed, constitutively, in three different anatomical regions of human skin (foreskin, breast, abdomen). Densitometric analysis of the immunoreactive bands revealed differential constitutive expression of these enzymes in foreskin, breast, and abdomen skin. Immunohistochemistry showed the presence of class I ADH and class III ADH enzymes, predominantly in the epidermis with some localised expression in the dermal appendages of human skin. In comparison, staining for class II ADH was more faint in the epidermis with very little dermal expression. Class 1 ALDH and class 3 ALDH were predominantly localised to the epidermis with minimal, highly localised dermal appendageal expression. These cutaneous ADH and ALDH enzymes may play significant roles in the metabolism of endogenous or xenobiotic alcohols and aldehydes.
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Olive C, Cheung C, Falk MC. Apoptosis and expression of cytotoxic T lymphocyte effector molecules in renal allografts. Transpl Immunol 1999; 7:27-36. [PMID: 10375075 DOI: 10.1016/s0966-3274(99)80016-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Cytotoxic T lymphocyte (CTL) mediated apoptosis is thought to play a major role in the rejection of renal allografts following transplantation, however, the CTL effector mechanism that is primarily responsible for immunological rejection is unknown. The two major effector pathways of CTL killing which lead to apoptosis involve the Fas/Fas ligand (Fas L) lytic pathway, and the perforin/granzyme degranulation pathway. The expression of CTL effector molecules which influence these pathways include Fas, Fas L and TiA-1 (cytotoxic granule protein). This study has investigated apoptosis by in situ terminal deoxytransferase-catalysed DNA nick end labelling (TUNEL), and the expression of CTL effector molecules by immunohistochemistry, in renal allograft biopsies obtained from patients following kidney transplantation. Renal biopsies were classified into three histological groups; acute cellular rejection, chronic rejection, or no rejection. The extent of T-cell infiltration of renal tissues was assessed by immunohistochemical staining with an anti-CD3 monoclonal antibody. Numerous TUNEL positive cells were detected in all transplant biopsies examined; these consisted mainly of renal tubular cells and infiltrating cells, with some TUNEL positive cells also detected in the glomeruli. In the case of normal kidney tissue, renal cells also stained positive for TUNEL but there was no lymphocytic infiltration. There was significantly more T-cell infiltration observed in acute rejection biopsies compared to the no rejection biopsies. In the case of Fas L expression, there was little expression in all three biopsy groups, apart from one case of chronic rejection. Conversely, although there were no significant differences in TiA-1 expression between the three biopsy groups, TiA-1 expression was more prominent in acute rejection biopsies. Furthermore, Fas expression was significantly decreased in acute rejection biopsies when compared to those of chronic and no rejection in which Fas was predominantly localized in the renal tubular cells. These results indicate that the mechanism of CTL killing leading to the rejection of renal allografts may be different in acute and chronic rejection. Moreover, our data indicate the potential for cytotoxic granule-based CTL killing in acute renal allograft rejection but not in chronic rejection.
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Abstract
The aim of this investigation was to compare the frequency of alleles at the HLA-C locus in patients with psoriatic arthritis to that in the disease free population and to relate the HLA genes to disease phenotype in psoriatic arthritis (PsA). Ninety-four consecutive patients seen in the (PsA) clinic between April and July 1996 and 100 disease-free controls had HLA typing performed by both serologic and molecular techniques. Patients' disease was assessed according to a standard protocol. Fisher's exact test was used to compare the frequency of HLA alleles in the patients and controls. HLA-C determined by PCR-SSP decreased the frequency of non-identified, that is, "blank" (or null) alleles to 6% in patients and controls. HLA-Cw*0602 was present in 32 patients and 18 controls: allele frequency of 17% in the patients versus 9% in the controls (p < 0.01). Amongst patients with psoriatic arthritis, those who carried the HLA-Cw*0602 allele had a significantly earlier mean age of onset of their psoriasis (p = 0.003). This study confirms that molecular DNA techniques improve detection of C-locus alleles. The HLA-Cw*0602 is increased amongst patients with psoriatic arthritis compared to controls. The HLA-Cw*0602 is associated with an earlier age of onset of psoriasis.
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Olive C, Cheung C, Nicol D, Falk MC. Expression of apoptotic regulatory molecules in renal cell carcinoma: elevated expression of Fas ligand. Immunol Cell Biol 1999; 77:11-8. [PMID: 10101681 DOI: 10.1046/j.1440-1711.1999.00791.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Renal cell carcinoma (RCC) is the most common renal neoplasm. Despite being infiltrated by tumour infiltrating lymphocytes (TIL), these TIL are unable to control tumour growth in vivo, suggesting that the cytotoxic capacity of TIL against RCC is impaired, or that the tumour cells are resistant to killing and therefore escape detection by the immune system. It is postulated that the expression of apoptotic regulatory molecules in RCC favours tumour cell survival. The present study has therefore determined the expression of Fas (APO-1/CD95), Fas ligand (Fas L) and bcl-2 in these tumours. The expression of Fas, Fas L and bcl-2 mRNA transcripts was determined in RCC, normal kidney and peripheral blood by semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR), following RNA extraction and cDNA synthesis from tissues and cell samples. Transcript levels were measured by densitometry after Southern blot hybridization of PCR products with internal radio-labelled oligonucleotide probes; a densitometry score was assigned to each hybridizing DNA band and expressed as a ratio of the glyceraldehyde-3-phosphate dehydrogenase content. In peripheral blood, the expression of Fas L and bcl-2 transcripts was similar between patients and normal healthy individuals; however, Fas transcript expression was significantly down-regulated in the patients' versus normal peripheral blood (P = 0.026). Most interestingly, significantly up-regulated Fas L expression was observed in RCC compared to normal kidney (P = 0.041). In contrast, bcl-2 transcripts were well represented in normal kidney but markedly decreased in RCC (P = 0.021). The expression of Fas transcripts in normal kidney and RCC was variable. These data demonstrate elevated expression of Fas L transcripts in RCC, but the functional relevance of this remains to be investigated.
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93
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Olive C, Cheung C, Falk MC. T cell engraftment in lymphoid tissues of human peripheral blood lymphocyte reconstituted SCID mice with or without prior activation of cells. Immunol Cell Biol 1998; 76:520-5. [PMID: 9893029 DOI: 10.1046/j.1440-1711.1998.00786.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The reconstitution of severe combined immunodeficiency (SCID) mice with human PBL (Hu-PBL-SCID) was assessed using fresh unstimulated PBL and anti-CD3-stimulated PBL. Mice were reconstituted with PBL by intraperitoneal injection of 1-2.5 x 107 PBL in PBS; controls received PBS. Successful engraftment of human PBL in SCID mice was determined by measurement of human IgG in mouse sera, polymerase chain reaction (PCR) detection of human-specific HLA-DRbeta DNA in SCID periphery, and immunohistochemical staining of mouse tissues (spleen, lymph nodes, thymus, liver and lung) with antibodies specific for human CD45 and CD3. Human IgG was detected 1 week after reconstitution in sera of all animals that received at least 1 x 107 PBL and continued to increase for 8 weeks. Human-specific HLA-DRbeta DNA was detected in the majority of mice 3 weeks after reconstitution but not in controls. Moreover, immunohistochemical analysis of Hu-PBL-SCID mouse tissues revealed the presence of human CD45+ cells in all tissues examined. CD3+ T cell engraftment was observed in lymphoid tissues irrespective of whether PBL had been activated prior to transfer or not.
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94
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Olive C, Cheung C, Nicol D, Falk MC. Expression of cytokine mRNA transcripts in renal cell carcinoma. Immunol Cell Biol 1998; 76:357-62. [PMID: 9723777 DOI: 10.1046/j.1440-1711.1998.00759.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Renal cell carcinoma (RCC) is a solid tumour of the kidney and is the most common renal neoplasm. Despite the presence of tumour infiltrating lymphocytes (TIL) in RCC, these tumours continue to progress in vivo suggesting a poor host immune response to the tumour, and the suppression of TIL effector function. Cytokines are key molecules that modulate the function of T cells. The possibility is investigated that the local production of cytokines in RCC contributes to immunosuppression of TIL. The expression of pro-inflammatory (IFN-gamma/IL-2) and immunosuppressive (IL-10/TGF-beta) cytokine mRNA transcripts was determined in RCC, normal kidney and peripheral blood of RCC patients using a semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) with cytokine-specific primers. Following Southern blot hybridization of the PCR products with internal radiolabelled oligonucleotide probes, cytokine transcript levels were measured by densitometry and expressed relative to the glyceraldehyde-3-phosphate dehydrogenase densitometry score. With the exception of IL-10, there were no differences in expression of cytokine mRNA transcripts between the peripheral blood of patients and normal healthy individuals. It was found that TGF-beta transcripts were well represented in normal kidney and RCC. In contrast, the expression of IFN-gamma transcripts, while low in the majority of samples, was significantly increased in RCC when compared to normal kidney (P=0.05). The IL-2 and IL-10 transcripts showed a more variable expression in normal kidney and RCC, with no significant differences in expression between the sample groups. The data demonstrating pro-inflammatory and immunosuppressive cytokine expression in RCC do not support a prominent immunosuppressive cytokine profile in these tumours.
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95
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Keating J, Cheung C, Peters TJ, Sherwood RA. Carbohydrate deficient transferrin in the assessment of alcohol misuse: absolute or relative measurements? A comparison of two methods with regard to total transferrin concentration. Clin Chim Acta 1998; 272:159-69. [PMID: 9641357 DOI: 10.1016/s0009-8981(98)00008-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Carbohydrate deficient transferrin (CDT) is now accepted as a potentially useful marker for the detection of alcohol misuse. It is not clear whether absolute values or values expressed relative to the total transferrin concentration provide the same diagnostic efficiency. CDT was measured in 35 patients with alcohol related liver disease, 35 subjects abusing alcohol without evidence of liver disease and 35 patients with chronic viral hepatitis using two commercial methods (CDTect and %CDT). To compare the methods, results were normalised by dividing the actual result by the upper limit of the reference range. Subtracting normalised %CDT results from the normalised CDTect results demonstrated a linear relationship between CDTect and total transferrin. This linear relationship could be abolished by calculating the CDTect/total transferrin ratio. The sensitivity of the methods was similar with CDTect (43 and 57%) being slightly superior to %CDT (40 and 46%). Specificity was similar (78%) for both methods. Calculation of the CDTect/total transferrin ratio improved the sensitivity and specificity slightly. The linear relationship between CDTect and total transferrin may produce misleading results in populations with a high prevalence of abnormal total transferrin concentrations and could cause difficulties in method comparisons unless taken into account.
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MESH Headings
- Adolescent
- Adult
- Aged
- Aged, 80 and over
- Alcoholism/blood
- Alcoholism/complications
- Alcoholism/diagnosis
- Biomarkers/blood
- Chromatography, Ion Exchange/methods
- Female
- Hepatitis, Chronic/blood
- Hepatitis, Chronic/complications
- Hepatitis, Viral, Human/blood
- Hepatitis, Viral, Human/complications
- Humans
- Liver Diseases, Alcoholic/blood
- Liver Diseases, Alcoholic/complications
- Male
- Middle Aged
- Sensitivity and Specificity
- Transferrin/analogs & derivatives
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96
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Narayanan T, Cheung C, Tong P, Goldburg WI, Wu XL. Measurement of the velocity difference by photon correlation spectroscopy: an improved scheme. APPLIED OPTICS 1997; 36:7639-7644. [PMID: 18264279 DOI: 10.1364/ao.36.007639] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Homodyne photon correlation spectroscopy is used to measure the velocity difference delta v (l) over varying distance l. Different length scales are probed when the magnification factor M and the width S of a slit in the collecting optics are varied. The measured intensity autocorrelation function is found to be of scaling form for different values of M, provided S is kept at a value below the critical width S (c). A new convenient collecting optics is devised to expand the variable range of l up to 2 decades, over which delta v (l) can be accurately measured. The new scheme is useful for the study of turbulent and other self-similar flows.
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97
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Cheung C. Vascular Endothelial Growth Factor: Possible Role in Fetal Development and Placental Function. ACTA ACUST UNITED AC 1997. [DOI: 10.1016/s1071-5576(97)00025-7] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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98
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Pollanen MS, Cheung C, Chiasson DA. The diagnostic value of the diatom test for drowning, I. Utility: a retrospective analysis of 771 cases of drowning in Ontario, Canada. J Forensic Sci 1997; 42:281-5. [PMID: 9068187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The utility and validity of the diatom test for drowning was studied using a retrospective analysis of 771 cases of drowning mostly from Ontario, Canada, over the period 1977 to 1993. In this article (part one), the utility of the test was assessed using an analysis of test outcomes. In the companion article (part two), the validity of the test was assessed by analyzing the relationship between test outcome and characteristics of diatoms in the bone marrow and samples of putative drowning medium. In the present study, freshwater drownings accounted for 738 of the cases and 33 cases were drownings in bathtubs, pools, or toilets. Diatoms were recovered from the femoral bone marrow of 205 cases (28%) of freshwater drowning and four cases (12%) of domestic water drowning. There was a monthly variation in the frequency of positive test outcomes that could not be explained by seasonal differences in the total number of drownings. However, the monthly variation was strongly correlated with the periodic cycle of diatom blooms that occurs in freshwater. Positive diatom tests were characterized by a limited number of distinctive diatom species per case, and a restricted quantity and size range of diatom frustules. These results indicate that the diatom test for drowning will identify approximately one in three victims of freshwater drowning and may be useful in the assessment of deaths occurring in bathtubs. The correlation of the outcome of the diatom test for drowning with diatom blooms provides further evidence for the reliability of the test.
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99
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Wong SH, Yuen AP, Cheung C, Wei WI, Lam LK. Long-term results of voice rehabilitation after total laryngectomy using primary tracheoesophageal puncture in Chinese patients. Am J Otolaryngol 1997; 18:94-8. [PMID: 9074732 DOI: 10.1016/s0196-0709(97)90094-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
PURPOSE Prosthetic voice restoration is an increasingly popular method of postlaryngectomy voice rehabilitation. Despite its success in non-tonal languages, the efficacy of tracheoesophageal speech in tonal languages was largely unknown. The aim of the present study was to evaluate the long-term results of voice rehabilitation using a Blom-Singer valve (BSV) in the tonal language of Cantonese. PATIENTS AND METHODS The records of 159 patients who underwent total laryngectomy and primary tracheoesophageal puncture (TEP) between May 1985 and December 1994 were retrospectively reviewed. Tracheoesophageal speech was regarded as functional if effective communication could be made during face-to-face conversation and telephone conversation. Any TEP-related complications were noted. Perioperative factors that might contribute to nonfunctional speech were subjected to statistical analysis. RESULTS Six hospital mortalities were excluded from speech analysis. Of the remaining 153 patients, the median follow-up was 25 months, ranging from 3 to 113 months. Seventy-three patients had closure of tracheosophageal fistulae (TEF), and the main causes were ineffective voice production, dislodgment, and tracheostomal stenosis. Only 15 of them acquired functional speech before closure. The other 80 patients used a BSV as the chief modality of voice rehabilitation, with functional results achieved in 64 patients. None of the perioperative factors were found to be statistically significant in relation to nonfunctional speech. CONCLUSION Primary TEP is an established method of voice rehabilitation after total laryngectomy. In our series, 52% patients achieved functional tracheoesophageal speech using a BSV.
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100
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Tremblay F, De Becker I, Cheung C, LaRoche GR. Visual evoked potentials with crossed asymmetry in incomplete congenital stationary night blindness. Invest Ophthalmol Vis Sci 1996; 37:1783-92. [PMID: 8759345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
PURPOSE To investigate a proposed postretinal defect in patients with the incomplete form of congenital stationary night blindness (CSNB2) and to compare visual evoked potential (VEP) results with those found in various forms of albinism. METHODS Visual evoked potentials were performed in 10 patients with a diagnosis of CSNB2, 10 subjects with albinism, and 17 normal subjects. Visual evoked potentials were elicited monocularly with diffuse flash stimulation. Scalp electrodes were placed over each hemisphere and referred to the forehead. Interhemispheric bipolar recordings were derived, and the correlation coefficient (CC) was calculated for various segments of the interhemispheric responses. RESULTS A crossed visual evoked potential asymmetry pattern could be demonstrated in 9 of 10 patients with CSNB2. All subjects with albinism and none of the normal subjects showed the crossed asymmetry pattern. Statistical comparison of the CC computed for various segments of the interhemispheric response shows that the pattern of inversion in CSNB2 is more prominent in the 25 to 100 msec range (median CC, -0.37) and in the 175 to 250 msec range (CC, -0.27). In subjects with albinism, all segments show a negative CC (range, -0.46 to -0.60). In normal subjects, all segments are positively correlated (range, 0.36 to 0.66). CONCLUSIONS Crossed visual evoked potential asymmetry was found in patients with CSNB2; therefore, excessive decussation, as demonstrated by this testing procedure, should not be considered as pathognomonic for albinism.
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