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Yeh E, Ng S, Starich T, Shaw J, Zhen M. [P64]: The
C. elegans
gap junction protein UNC‐7 is required for chemical synapse formation. Int J Dev Neurosci 2006. [DOI: 10.1016/j.ijdevneu.2006.09.127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Wilder-Smith A, Ng S, Earnest A. Seroepidemiology of pertussis in the adult population of Singapore. ANNALS OF THE ACADEMY OF MEDICINE, SINGAPORE 2006; 35:780-2. [PMID: 17160193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
INTRODUCTION Pertussis is a highly communicable, vaccine-preventable respiratory disease and a frequent but often underestimated cause of prolonged cough illness in adults. Protection after childhood vaccination is minimal after 10 years without boosting. The need for adult booster depends on the national epidemiology. MATERIALS AND METHODS We did a seroepidemiological survey amongst the adult population (aged 18 to 45 years) of Singapore. None had received pertussis booster vaccine in the preceding 10 years. We measured IgG antibodies to pertussis whole cell antigen. RESULTS Two hundred and seventy subjects with the median age of 30 years were enrolled. We found positive IgG antibody levels in 97% of the population. Seropositivity was not associated with age, gender or race. CONCLUSION The seroprevalence in adults was much higher than the previously documented seroprevalence of around 50% in the adolescent age group in Singapore. The increase is most likely due to natural infection with B. pertussis. Pertussis booster vaccine for adolescents/young adults in Singapore would be indicated.
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Villemagne VL, Ng S, Cappai R, Barnham KJ, Fodero-Tavoletti MT, Rowe CC, Masters CL. La lunga attesa: towards a molecular approach to neuroimaging and therapeutics in Alzheimer's disease. Neuroradiol J 2006; 19:453-74. [PMID: 24351248 DOI: 10.1177/197140090601900406] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2006] [Accepted: 04/08/2006] [Indexed: 12/20/2022] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterised by the gradual onset of dementia. The pathological hallmarks of the disease are Aβ amyloid plaques, neurofibrillary tangles (NFT), synaptic loss and reactive gliosis. Current diagnosis of AD is made by clinical, neuropsychologic, and neuroimaging assessments. Routine structural neuroimaging evaluation with computed tomography (CT) and magnetic resonance imaging (MRI) is based on non-specific features such as atrophy, a late feature in the progression of the disease, hence the crucial importance of developing new approaches for early and specific recognition at the prodromal stages of AD. Functional neuroimaging techniques such as functional magnetic resonance imaging (fMRI), magnetic resonance spectroscopy (MRS), positron emission tomography (PET) and single photon emission computed tomography (SPECT), possibly in conjuction with other related Aβ biomarkers in plasma and CSF, could prove to be valuable in the differential diagnosis of AD, as well as in assessing prognosis. With the advent of new therapeutic strategies aimed at reducing the Aβ amyloid burden in the brain, there is increasing interest in the development of MRI contrast agents and PET and SPECT radioligands that will permit the assessment of Aβ amyloid burden in vivo. - ma dov'è / la lenta processione di stagioni / che fu un'alba infinita e senza strade, / dov'è la lunga attesa e qual è il nome / del vuoto che ci invade. - Eugenio Montale.
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Bissonnette RP, Fan B, Roegner K, Ng S, Corpuz M, Prudente R, Negro-Vilar A, Yen W. Cooperative antitumor activity between the retinoid X receptor (RXR)-selective agonist bexarotene and EGFR-tyrosine kinase inhibitors in preclinical models of NSCLC. J Clin Oncol 2006. [DOI: 10.1200/jco.2006.24.18_suppl.17073] [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
17073 Background: Gefitinib and erlotinib, small molecule inhibitors of the EGFR-tyrosine kinase (EGFR-TKI), can have antitumor activity in patients with advanced NSCLC. However, analysis of clinical samples and in vitro characterization of NSCLC cell lines has revealed EGFR mutations that correlate with the clinical responses. While EGFR-mutant cell lines are hypersensitive to EGFR-TKI-mediated growth inhibition and have a greater tendency to undergo apoptosis in response to EGFR inhibition, wild-type EGFR cell lines undergo growth inhibition only at high concentrations, and are resistant to apoptosis induction. Bexarotene (Targretin) is a RXR modulator with clinical activity enhancing survival in a subset of NSCLC patients. We have shown that bexarotene can suppress the growth of epithelial tumors by modulating the expression and function of the EGFR pathway. This study examined the effect of bexarotene/EGFR-TKI combinations in preclinical models of NSCLC, and evaluated the possible molecular mechanisms for cooperative antitumor activity between these agents. Results: Bexarotene enhanced the activity of gefitinib in most of the cell lines tested, and did so regardless of their EGFR mutation status or intrinsic sensitivity to gefitinib alone. Resistant lines were sensitized by the combination, which decreased gefitinib IC50s to clinically achievable concentrations. Bexarotene increased the pro-apoptotic activity of both gefitinib and erlotinib, an effect which was paralleled by enhanced repression of p-Akt and p-Her2 levels by the combinations. In ex vivo cultures of human NSCLC explant tissue, the addition of bexarotene enhanced the growth inhibitory activity of both gefitinib and erlotinib. Finally, combinations of bexarotene and EGFR-TKI produced growth inhibition of TKI-resistant A427 NSCLC xenograft tumors that was superior to either agent alone. Conclusions: These results indicate that bexarotene can sensitize NSCLC cells which are unresponsive to the effects of EGFR-TKIs, resulting in cooperative growth inhibition and apoptosis induction. Combination therapy using bexarotene in conjunction with EGFR-TKIs may provide a powerful new therapeutic strategy. [Table: see text]
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Hermann TW, Yen W, Tooker P, Ng S, Negro-Vilar A, Lamph WW. Bexarotene prevents and reverses gemcitabine resistance in non-small-cell lung cancer cells by affecting gene amplification. J Clin Oncol 2006. [DOI: 10.1200/jco.2006.24.18_suppl.2057] [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
2057 Background: Bexarotene (BEX) is a retinoid X receptor selective drug approved for treatment of CTCL and has activity in various cancers. Here we evaluate its effect on acquired drug resistance towards gemcitabine (GEM) in Calu3 NSCLC models. Methods: Parental or GEM-resistant Calu3 NSCLC cells were treated with BEX and GEM as single agents or in combination. Over the treatment course the cells were evaluated for molecular changes (RNA expression and DNA amplification), which were associated with resistance status. Results: Calu3 cells treated with repeated cycles of GEM alone gradually developed resistance to this drug. However, inclusion of BEX prevented the development of resistance and cells remained chemosensitive. Microarray analysis showed a strong increase of rrm1 (ribonucleotide reductase M1) expression in the resistant cells (Calu3-GemR), a gene known to be involved in GEM resistance. In addition, the expression of genes surrounding the chromosomal location of rrm1 was increased suggesting that resistance was due to gene amplification at the 11p15 locus. This was confirmed by analysis of genomic DNA, indicating a 20-fold increase of rrm1 gene copy number. To evaluate BEX’s activity on pre-existing GEM-resistance, Calu3-GemR cells were treated with ten 10-day cycles of vehicle, GEM, BEX, or GEM plus BEX. After 4 treatment cycles the cultures treated with the combination regimen showed a loss in cell numbers, which continued until the end of the 10th cycle. This indicated a re-sensitization of the Calu3-GemR cells to treatment. The cultures treated with the single drug regimens expanded as the vehicle controls. However, analysis of RNA and DNA samples collected over the treatment course revealed that rrm1 gene amplification was gradually reduced even in the cultures treated with BEX alone, reaching parental levels at the end of the study. As expected from these data, the BEX-treated Calu3-GemR cells were again sensitive to GEM. Conclusions: The data indicate that bexarotene can re-sensitize GEM-resistant tumor cells by reversing gene amplification. This suggests that bexarotene may have general clinical utility in cancers where drug-resistance by gene amplification is a major obstacle to successful therapy. [Table: see text]
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Ng SH, Chave TA. Tumoral melanosis as a manifestation of a completely regressed primary melanoma with metastases. Br J Dermatol 2006; 155:627-8. [PMID: 16911294 DOI: 10.1111/j.1365-2133.2006.07370.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Ng SH, Wang ZF, Shi ZF, Tjeung RT, Lok BK. Realization of a microelectrofluidic platform. ACTA ACUST UNITED AC 2006. [DOI: 10.1088/1742-6596/34/1/061] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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158
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Guo ZP, Ng SH, Wang JZ, Huang ZG, Liu HK, Too CO, Wallace GG. Electrochemical hydrogen storage in single-walled carbon nanotube paper. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2006; 6:713-8. [PMID: 16573126 DOI: 10.1166/jnn.2006.083] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Single-walled carbon nanotube (SWNT) papers were successfully prepared by dispersing SWNTs in Triton X-100 solution, then filtered by PVDF membrane (0.22 microm pore size). The electrochemical behavior and the reversible hydrogen storage capacity of single-walled carbon nanotube (SWNT) papers have been investigated in alkaline electrolytic solutions (6 N KOH) by cyclic voltammetry, linear micropolarization, and constant current charge/discharge measurements. The effect of thickness and the addition of carbon black on hydrogen adsorption/desorption were also investigated. It was found that the electrochemical charge-discharge mechanism occurring in SWNT paper electrodes is somewhere between that of carbon nanotubes (physical process) and that of metal hydride electrodes (chemical process), and consists of a charge-transfer reaction (Reduction/Oxidation) and a diffusion step (Diffusion).
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Chang J, Chen L, Lin C, Liao C, Chen I, Wang H, Ng S. Brain Necrosis in Nasopharyngeal Cancer Patients - Prospective Study with MRI. Int J Radiat Oncol Biol Phys 2005. [DOI: 10.1016/j.ijrobp.2005.07.628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Wai CT, Wong ML, Ng S, Cheok A, Tan MH, Chua W, Mak B, Aung MO, Lim SG. Utility of the Health Belief Model in predicting compliance of screening in patients with chronic hepatitis B. Aliment Pharmacol Ther 2005; 21:1255-62. [PMID: 15882247 DOI: 10.1111/j.1365-2036.2005.02497.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
BACKGROUND Regular surveillance is recommended for patients with chronic hepatitis B, to select candidates for anti-viral therapy and detect early complications. However, factors that determine compliance are not well studied. AIM To determine the utility of the Health Belief Model in explaining non-compliance, among a group of chronic hepatitis B patients for screening. METHODS A total of 192 chronic hepatitis B patients who responded to advertisement for free screening took part in a telephonic interview study. Subjects were asked about the five constructs of the Health Belief Model, and factors associated with recent screening were analysed. RESULTS The mean age of the subjects was 42.1 +/- 0.7 years; 77% white male, and 97% Chinese. About 108 patients (56%) had recent screening. At multivariate analysis, only the ability to remember date of follow-up (OR: 4.37; 95% CI: 2.07-9.17) and the perception of having to wait a long time for venepuncture (OR: 0.38; 95% CI: 0.19-0.79) were significantly associated with recent screening. CONCLUSION Future public health measures should include improving the logistics of follow-up procedures and providing reminders for screening to improve compliance.
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Wong AMC, Ng SH, Chen YL, Wong HF, Wan YL, Wai YY. Cortical dysplasia associating with abnormal vasculature complicated with subdural haemorrhage. Int J Clin Pract 2005:76-8. [PMID: 15875631 DOI: 10.1111/j.1368-504x.2005.00475.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Cortical dysplasia is a neuronal migration disorder occasionally associated with anomalous draining veins. However, to our knowledge, no intracranial haemorrhage in conjunction with this association has been reported in the literature. We herein report a 7-month-old baby girl with cortical dysplasia associated with an ipsilateral cortical draining vein and complicated with subdural haemorrhage, with the diagnosis made by computed tomography and magnetic resonance imaging. This case demonstrated that patients with this condition could have an excellent prognosis even when the anomalous veins coexist with intracranial haemorrhage. We postulate that venous rupture may be the cause of this condition and further discuss the possible pathophysiology.
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Dogan A, Ngu LSP, Ng SH, Cervi PL. Pathology and clinical features of angioimmunoblastic T-cell lymphoma after successful treatment with thalidomide. Leukemia 2005; 19:873-5. [PMID: 15744336 DOI: 10.1038/sj.leu.2403710] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Abstract
Combined hepatocellular-cholangiocarcinoma (HCC-CC) is a rare primary liver tumour. We report a carrier of both HBV and HCV presenting with intermittent abdominal pain, fever, chillness and elevated á-fetoprotein (AFP) of 1197 ng/ml. Computed tomography showed an irregular hypodense mass in the left lateral segment of the liver with vague contrast enhancement and multiple regional lymphadenopathy. Hepatic angiogram showed that the mass was hypovascular and the left portal vein was occluded with a tapered end. Percutaneous ultrasound-guided core needle biopsy of the liver yielded HCC-CC. We suggest that HCC-CC should be considered in hypovascular liver tumours with striking elevation of serum AFP and multiple regional lymphadenopathy.
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Li CC, Ko SF, Ng SH, Huang CC, Wan YL, Lee TY. Symptomatic giant Müllerian duct cyst in an infant: radiographic and CT findings. ABDOMINAL IMAGING 2004; 29:525-7. [PMID: 15024515 DOI: 10.1007/s00261-003-0143-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
We report an unusual case of Müllerian duct cyst in an 8-month-old infant who presented with frequent vomiting and recurrent urinary tract infections. Computed tomography showed a midline giant cyst in the pelvic floor. Delayed enhanced computed tomography demonstrated contrast filling of the cyst, indicating a communication with the urotract. Subsequent cystourethrogram and surgery confirmed a giant Müllerian duct cyst.
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Chan SC, Ko SF, Ng SH, Cheung YC, Chang JTC, Liao CT, Wang HM, Lui KW. Fluoroscopically guided percutaneous gastrostomy with modified gastropexy and a large-bore balloon-retained catheter in patients with head and neck tumors. Acta Radiol 2004; 45:130-5. [PMID: 15191094 DOI: 10.1080/02841850410003707] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
PURPOSE To report on fluoroscopically guided percutaneous gastrostomy (FPG) using a modified gastropexy technique with the insertion of a large-bore balloon-retained gastrostomy catheter in patients with head and neck tumors. MATERIAL AND METHODS Thirty-four patients with head and neck tumors underwent a modified gastropexy with two T-fasteners followed by the insertion of a 14-F ballooon-retained catheter through a peel-away introducer. The success rate and the complications of the procedures were evaluated at 14 days, 30 days, and 60 days. The complications were classified as: major complications that necessitated intensive and/or surgical treatment; minor complications that could be treated conservatively; and tube-related complications manageable by tube exchange. RESULTS FPG was technically successful in all cases. There were no major complications, two minor complications where superficial stoma infection was controlled by antibiotics, three minor tube-related complications, all three easily managed by catheter replacement via the original tract. CONCLUSION FPG with insertion of a large-bore balloon-retained catheter using a modified gastropexy technique is a safe and effective method that creates a feeding access for patients with head and neck tumors and esophageal obstruction. Minor complications can be managed conservatively. FPG may be a good alternative to surgical or percutaneous endoscopic gastrostomy.
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Huang CC, Ko SF, Chung MY, Shieh CS, Tiao MM, Lui CC, Ng SH. Infradiaphragmatic pulmonary sequestration combined with cystic adenomatoid malformation: unusual postnatal computed tomographic features. ACTA ACUST UNITED AC 2004; 29:439-42. [PMID: 15024518 DOI: 10.1007/s00261-003-0141-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
We present a surgically proven case of infradiaphragmatic pulmonary sequestration combined with cystic adenomatoid malformation. Prenatal magnetic resonance imaging revealed a well-defined hyperintense mass with a hypointense septum in the left infradiaphragmatic region. Postdelivery computed tomography (CT) and 3-month follow-up CT showed replacement of intralesional cystic areas by solid content. Such unusual postnatal CT changes, to our knowledge, have not been previously documented.
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Harwood J, Giles H, McCann RM, Cai D, Somera LP, Ng SH, Gallois C, Noels K. Older adults' trait ratings of three age-groups around the Pacific rim. J Cross Cult Gerontol 2004; 16:157-71. [PMID: 14617987 DOI: 10.1023/a:1010616316082] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
In this paper, we assess the traits that older adults associate with younger, middle-aged, and older adults in five Pacific Rim nations from Western and Eastern cultural traditions (Australia, People's Republic of China (PRC), Hong Kong, Philippines, Thailand). We find cross-cultural trends which replicate patterns found in the US context. In most cultures, attractiveness, strength, activity, liberalism, health, and flexibility are seen to decline with increasing age. Kindness assessments are positively associated with age across cultures. Mixed patterns are found with assessments of wisdom and generosity, with respondents from the PRC and Hong Kong being notably more negative about increasing age than other respondents. Implications for the aging process across cultures are discussed, and suggestions made for future research.
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Tan CF, Ng KK, Ng SH, Cheung YC. Magnetic resonance imaging of hyaline cartilage regeneration in neocartilage graft implantation. Transplant Proc 2003; 35:3105-7. [PMID: 14697990 DOI: 10.1016/j.transproceed.2003.10.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
BACKGROUND The purpose of this study was to investigate the regenerative potential of hyaline cartilage in a neocartilage graft implant with the aid of MR cartilage imaging using a rabbit model. METHODS Surgical osteochondral defects were created in the femoral condyles of 30 mature New Zealand rabbits. The findings of neocartilage in autologous cartilage grafts packed into osteochondral defects were compared with control group of no implant to the osteochondral defect. The outcome of the implantations was correlated with histologic and MR cartilage imaging findings over a 3-month interval. RESULTS Neocartilage grafts packed into osteochondral defects showed regeneration of hyaline cartilage at the outer layer of the implant using MR cartilage imaging. Fibrosis of fibrocartilage developed at the outer layer of the autologous cartilage graft together with an inflammatory reaction within the osteochondral defect. CONCLUSION This animal study provides evidence of the regenerative ability of hyaline cartilage in neocartilage transplants to repair articular cartilage.
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Mitchell PLR, Basser R, Chipman M, Grigg A, Cebon J, Davis ID, Zalcberg J, Ng S, Appia F, Green M. A phase I dose-escalation study of docetaxel with granulocyte colony-stimulating factor support in patients with solid tumours. Ann Oncol 2003; 14:788-94. [PMID: 12702535 DOI: 10.1093/annonc/mdg202] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Docetaxel is a widely active cytotoxic agent. The principal dose-limiting toxicities (DLTs) of the 3-weekly regimen are neutropenia and febrile neutropenia. Use of prophylactic granulocyte colony-stimulating factor (G-CSF) may allow higher doses of docetaxel to be administered with potentially greater anticancer efficacy. The objectives of this study were to determine the maximum tolerated dose (MTD) and toxicity profile of docetaxel given with G-CSF support. PATIENTS AND METHODS Eligible patients had solid tumours and were aged 18-75 years with a WHO performance status of up to 2. Strict criteria for liver function were followed. Patients may have received one previous regimen of chemotherapy in addition to adjuvant chemotherapy. Cohorts of three to six patients received docetaxel over 60-90 min every 3 weeks, commencing at 110 mg/m(2) and escalating at 10 mg/m(2) increments. Patients also received G-CSF 5 micro g/kg/day until neutrophil recovery. A 3-day corticosteroid prophylaxis was given. RESULTS Twenty-nine patients with median age 55 years (range 29-75) were included. Fourteen (48%) had previously received chemotherapy. At the 170 mg/m(2) dose level (the MTD), two of three patients had DLTs and 160 mg/m(2) was determined to be the recommended dose. The principal DLTs were skin and neurosensory toxicity. Asthenia was frequent, especially at dose levels >/=140 mg/m(2). Grade 4 neutropenia occurred in only 10 patients (35%) and was not dose related, with febrile neutropenia in three patients (10%). CONCLUSIONS Docetaxel may be escalated considerably above standard doses when administered with G-CSF support. The recommended dose for phase II studies is 160 mg/m(2). With escalated-dose docetaxel, DLTs were non-haematological and qualitatively similar to the toxicity profile at standard doses.
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Yau Y, Piper I, Contant C, Citerio G, Kiening K, Enblad P, Nilsson P, Ng S, Wasserberg J, Kiefer M, Poon W, Dunn L, Whittle I. Multi-centre assessment of the Spiegelberg compliance monitor: interim results. ACTA NEUROCHIRURGICA. SUPPLEMENT 2003; 81:167-70. [PMID: 12168294 DOI: 10.1007/978-3-7091-6738-0_43] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Analyses of a multi-centre database of 71 patients at risk of raised ICP showed that in head injured patients (n = 19) and tumour patients (n = 13) clear inverse relationships of ICP vs compliance exist. SAH patients (n = 5) appear to exhibit a biphasic relationship between ICP and compliance, however greater numbers of patients need to be recruited to this group. Patients with hydrocephalus (n = 34) show an initial decrease in compliance while ICP is less than 20 mmHg, thereafter compliance does not show a dependence upon ICP. A power analysis confirmed that sufficient numbers of patients have been recruited in the hydrocephalus group and a ROC analysis determined that a mean compliance value of 0.809 (lower and upper 95% CL = 0.725 & 0.894 resp.) was a critical threshold for raised ICP greater than 10 mmHg. Preliminary time-series analyses of the ICP and compliance data is revealing evidence that the cumulative time compliance is in a low compliance state (< 0.5 ml/mmHg), as a proportion of total monitoring time, increases more rapidly than the cumulative time ICP is greater than 25 mmHg. Before trials testing compliance thresholds can be designed, we need to consider not just the absolute threshold, but the duration of time spent below threshold. A survey may be required to identify a consensus of what is the minimum duration of raised ICP above 25 mmHg needed to instigate treatment.
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Tsui EYK, Yip SF, Ng SH, Cheung YK. Reversible MRI changes of hypothalamus in a multiple sclerosis patient with homeostatic disturbances. Eur Radiol 2002; 12 Suppl 3:S28-31. [PMID: 12522597 DOI: 10.1007/s00330-002-1468-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2001] [Revised: 03/15/2002] [Accepted: 03/20/2002] [Indexed: 10/25/2022]
Abstract
Multiple sclerosis (MS) patients occasionally present with homeostatic disturbances suggestive of hypothalamic dysfunction; however, the hypothalamus often appears normal on imaging, apart from confirmation in a few necropsy studies. In this article we describe a Chinese woman with atypical clinical presentation. She presented with relapsing symptoms and signs consistent with hypothalamic dysfunction including hyperprolactinema, syndrome of inappropriate secretion of anti-diuretic hormone (SIADH), hypersomnolence and temperature dysregulation. Serial MRI depicted the atypical reversible changes in the hypothalamus, correlating with the observed homeostatic abnormalities.
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Tsui EYK, Ng SH, Chow L, Lai KF, Fong D, Chan JHM. Syphilitic myelitis with diffuse spinal cord abnormality on MR imaging. Eur Radiol 2002; 12:2973-6. [PMID: 12439578 DOI: 10.1007/s00330-001-1244-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2001] [Accepted: 10/25/2001] [Indexed: 12/21/2022]
Abstract
Syphilitic myelitis is a very rare manifestation of neurosyphilis. The MRI appearance of syphilitic myelitis is not well documented and only a few cases have been reported. We present a 52-year-old woman with acute onset of paraplegia. Magnetic resonance imaging of the spine showed diffuse high signal intensity in the whole spinal cord on T2-weighted images. Focal enhancement was observed in the dorsal aspect of the thoracic cord on T1-weighted gadolinium-enhanced images. To our knowledge, diffuse spinal cord abnormality in syphilitic myelitis has not been reported in the international literature. Disappearance of the diffuse high-signal lesions with residual focal enhancement was noted after antibiotic therapy. The patient suffered significant neurological deficit despite improvement in the MR images. In this article we present the imaging findings and review the literature of this rare condition.
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Agha A, Ng S, Rogers B, Phillips J, Thompson CJ. Treatment outcome in acromegaly: results from the Beaumont Hospital pituitary database. Ir J Med Sci 2002. [DOI: 10.1007/bf03170245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Tsui EYK, Leung WH, Chan JH, Cheung YK, Ng SH. Tumefactive demyelinating lesions by combined perfusion-weighted and diffusion weighted imaging. Comput Med Imaging Graph 2002; 26:343-6. [PMID: 12204240 DOI: 10.1016/s0895-6111(02)00017-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Tumefactive demyelinating lesion may sometimes mimic intracranial neoplasm or abscess and pose a diagnostic problem both clinically and radiologically. The diagnosis is even more complicated since multiple sclerosis is relatively uncommon among Chinese and due to low incidence of oligoclonal protein in the cerebrospinal fluid. We present a Chinese lady with tumefactive demyelinating lesion, which mimic cystic neoplasm and cerebral abscess. The use of perfusion and diffusion weighted imaging obviated unnecessary surgical biopsy.
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Tsui EYK, Chan JH, Cheung YK, Lai KF, Fong D, Ng SH. Evaluation of cerebral abscesses by diffusion-weighted MR imaging and MR spectroscopy. Comput Med Imaging Graph 2002; 26:347-51. [PMID: 12204241 DOI: 10.1016/s0895-6111(02)00018-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Cerebral abscess may sometimes mimic necrotic tumor and cystic metastases both clinically and radiologically. The imaging findings may be indistinguishable on conventional magnetic resonance imaging. Although recent studies have shown that cerebral abscess displays restricted diffusion on diffusion-weighted imaging (DWI), it is not pathognomic. Necrotic tumor and cystic metastases may occasionally have restricted diffusion on DWI. Since the urgency of surgical intervention and approach of surgery is different, MR Spectroscopy may be used in conjunction with DWI in establishing the correct diagnosis.
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