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Ee HL, Yosipovitch G, Chan R, Ong BH. Resolution of vulvitis circumscripta plasmacellularis with topical imiquimod: two case reports. Br J Dermatol 2003; 149:638-41. [PMID: 14511002 DOI: 10.1046/j.1365-2133.2003.05583.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Vulvitis circumscripta plasmacellularis (VCP) is a rare but well-described entity. It is notorious for its recalcitrant nature to various modalities of treatment. Intralesional interferon-alpha showed some promise, with complete resolution, but is coupled with the side-effect of myelosuppression. Topical imiquimod is a novel immune response modifier with the ability to induce the production of interferon-alpha. In this paper, we report two cases of VCP whose lesions were resistant to antibiotics, topical and oral corticosteroids, but resolved after a treatment trial with imiquimod.
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Lopez FJ, Arias L, Chan R, Clarke DE, Elworthy TR, Ford APDW, Guzman A, Jaime-Figueroa S, Jasper JR, Morgans DJ, Padilla F, Perez-Medrano A, Quintero C, Romero M, Sandoval L, Smith SA, Williams TJ, Blue DR. Synthesis, pharmacology and pharmacokinetics of 3-(4-aryl-piperazin-1-ylalkyl)-uracils as uroselective alpha1A-antagonists. Bioorg Med Chem Lett 2003; 13:1873-8. [PMID: 12749888 DOI: 10.1016/s0960-894x(03)00305-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Predominance in the urethra and prostate of the alpha(1A)-adrenoceptor subtype, which is believed to be the receptor mediating noradrenaline induced smooth muscle contraction in these tissues, led to the preparation of alpha(1A)-selective antagonists to be tested as uroselective compounds for the treatment of benign prostatic hyperplasia. Thus, a number of selective alpha(1A)-adrenoceptor antagonists were synthesized and assayed in vitro for potency and selectivity. Dog pharmacokinetic parameters of 12 (RO700004) and its metabolite 40 (RO1104253) were established. The relative selectivity of intravenously administered 12, 40 and standard prazosin to inhibit hypogastric nerve stimulation-induced increases in intraurethral prostatic pressure versus phenylephrine-induced increases in diastolic blood pressure in anesthetized dogs was 76, 71 and 0.6, respectively.
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Lim D, Van Bever H, Chan R, Chua K. Anaphylaxis after hamster bites—Identification of a novel allergen. J Allergy Clin Immunol 2003. [DOI: 10.1016/s0091-6749(03)81180-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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129
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Gordon AE, El Ahmer OR, Chan R, Al Madani OM, Braun JM, Weir DM, Busuttil A, Blackwell CC. Why is smoking a risk factor for sudden infant death syndrome? Child Care Health Dev 2002; 28 Suppl 1:23-5. [PMID: 12515434 DOI: 10.1046/j.1365-2214.2002.00007.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Smoking is a major risk factor for both Sudden Infant Death Syndrome (SIDS) and respiratory tract infections. Such infections, both viral and bacterial, also increase the SIDS risk. This study investigated the effect of cigarette smoke at two stages of infection: 1) mucosal surface colonization; 2) induction and control of inflammatory responses. For colonization, RSV or influenza A infected cells bound several bacterial species in significantly higher numbers due to increased expression of host cell antigens. Buccal epithelial cells from smokers bound significantly more bacteria. For Staphylococcus aureus, this was associated with increased tar levels. Some SIDS deaths have been proposed to result from high levels of pro-inflammatory mediators elicited by infection and/or cigarette smoke during a developmental period when infants are less able to control inflammatory responses. Inflammatory reponses were compared between blood samples from smokers (n = 42) and non-smokers (n = 60) stimulated with TSST-1 or LPS. Non-smokers had significantly higher IL-6 (P = 0.011), IFN (P = 0.003) and IL-10 (P = 0.000) baseline levels. Non-smokers had higher IFN (P = 0.008) and IL-1 (P = 0.001, 0.007) responses to LPS and higher IL-10 responses to TSST-1 (P < 0.05) and LPS (P < 0.000). This study highlights that smoking increases the SIDS risk by greater susceptibility to viral and bacterial infections and enhanced bacterial binding after passive coating of mucosal surfaces with smoke components. In animal models, IL-10 reduced the lethal effect of staphylococcal toxins. In this study, smokers had lower IL-10 responses toTSST-1 and LPS. Dose response effects of cigarette smoke exposure needs to be established in relation to inflammatory response control and infantile infections.
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Stanga PE, Kychenthal A, Fitzke FW, Halfyard AS, Chan R, Bird AC, Aylward GW. Retinal pigment epithelium translocation and central visual function in age related macular degeneration: preliminary results. Int Ophthalmol 2002; 23:297-307. [PMID: 11944854 DOI: 10.1023/a:1014482025960] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
PURPOSE To test the feasibility of a new surgical technique, and to assess visual function over the translocated retinal pigment epithelium (RPE) cells in patients operated upon for subfoveal choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD). MATERIALS AND METHODS Six patients presenting previously untreated exudative AMD underwent surgical excision of the subfoveal CNV with RPE translocation and were followed from 1 to 10.5 months. The surgery consisted of a standard three port pars plana vitrectomy (TPPPV), excision of the CNV and RPE translocation. Pre and post-operative ocular examination included best-corrected visual acuity measurement, fundus color stereo photography and fundus fluorescein angiography. Optical coherence tomography (OCT) and confocal laser scanning ophthalmoscopy (cLSO) were performed post-operatively. A cross fixation target and a single-point flashing light were projected on different areas of the posterior pole using a cLSO. Photopic 10-2 perimetry, photopic fine matrix mapping, cLSO microperimetry were also performed pre and post-operatively in four patients. OCT cross-sectional scans and cLSO RPE autofluorescence were recorded to detect the presence of viable translocated RPE. Visual acuity, fixation, photopic 10-2 perimetry, photopic fine matrix mapping and cLSO microperimetry were tested for the presence of central visual function. RESULTS RPE could be effectively translocated at the time of CNV removal from the edge of the RPE defect to a subfoveal location. OCT showed the translocated RPE as an area of increased optical reflectivity with optical shadowing external to it. cLSO showed autofluorescence of the translocated RPE. The cross fixation target was seen when projected on the translocated RPE. During eccentric fixation, the patients could see a flashing point-target projected on the translocated RPE. Photopic 10-2 perimetry, photopic fine matrix mapping and cLSO microperimetry showed presence of central visual function. CONCLUSIONS The authors propose that translocation of RPE at the time of CNV removal, from the edge of the RPE defect to a subfoveal location, may have a role in the surgical management of AMD.
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Stanga PE, Kychenthal A, Fitzke FW, Halfyard AS, Chan R, Asaria RH, Bird AC, Aylward GW. Functional assessment of the native retinal pigment epithelium after the surgical excision of subfoveal choroidal neovascular membranes type II: preliminary results. Int Ophthalmol 2002; 23:309-16. [PMID: 11944855 DOI: 10.1023/a:1014434110031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Pirie-Shepherd SR, Coffman KT, Resnick D, Chan R, Kisker O, Folkman J, Waters DJ. The role of angiostatin in the spontaneous bone and prostate cancers of pet dogs. Biochem Biophys Res Commun 2002; 292:886-91. [PMID: 11944897 DOI: 10.1006/bbrc.2002.6749] [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: 11/22/2022]
Abstract
Angiostatin is a potent inhibitor of angiogenesis generated in cancer-bearing hosts by tumor-derived proteases. Because the naturally occurring bone and prostate cancers of pet dogs provide unique model systems to study factors that regulate cancer progression and tumor dormancy, we investigated the capacity of these tumors to generate angiostatin. We determined that angiostatin fragments are present in urine of dogs with bone cancer. The identity of these fragments was confirmed by comparison of the experimentally determined protein sequence to that of a clone of canine angiostatin. Importantly, these fragments were absent in urine collected from the same dogs after complete surgical removal of the primary tumor. We also demonstrate that canine prostate cancer cells are capable of processing plasminogen to angiostatin in vitro. These findings provide rationale for using spontaneous canine tumor models to isolate endogenous angiogenesis inhibitors and to investigate their therapeutic use against cancer.
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Chan R, Morrill S, Freeman D, Colman M, Zwischenberger J. Bi-modality (chemo-radiation) versus tri-modality (chemo-radiation followed by surgery) treatment for carcinoma of the esophagus. Dis Esophagus 2002; 14:202-7. [PMID: 11869320 DOI: 10.1046/j.1442-2050.2001.00185.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The purpose of the study was to investigate the difference in overall survival in patients with localized carcinoma of esophagus treated using chemo-radiation (bi-modality, BM) or chemo-radiation followed by surgery (tri-modality, TM). From 1981 to 1999, 65 patients were identified who had localized carcinoma of the esophagus treated with either concurrent chemo-radiation (BM, n=22) or concurrent chemo-radiation followed by surgery (TM, n=43) at the University of Texas Medical Branch at Galveston. All 65 patients received concurrent chemotherapy and external beam radiation. Radiation was delivered by linear accelerators (greater-than-or-equal 6 MV), except in one patient who had part of his treatment given by a Co-60 machine. Chemotherapy consisted of 5-fluorouracil and cisplatin plus minus vinblastine under different regimens. Median follow-up time was 10 months (range=1-195 months) for all patients. Of the 14 patients still alive, the median follow-up time was 32 months (range=2-192 months). No difference in overall survival was detected between the two treatment groups, BM vs. TM (P=0.394) despite a selection bias favoring the TM group. Five-year survival rates of the BM and TM groups were 17% and 18%, respectively; 10-year survival rates were 17% and 12%, respectively. The presence of significant past medical history (P=0.017) and a complete pathologic response in the TM group (P < 0.001) were significant independent predictors of survival. We did not find any difference in survival between chemo-radiation or chemo-radiation followed by surgery in patients with localized carcinoma of the esophagus. Use of biologic markers and functional imaging should be explored in order to segregate patients with different tumor biology for treatment using different treatment strategies.
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Liu S, Liu W, Jakubczak JL, Erexson GL, Tindall KR, Chan R, Muller WJ, Adhya S, Garges S, Merlino G. Genetic instability favoring transversions associated with ErbB2-induced mammary tumorigenesis. Proc Natl Acad Sci U S A 2002; 99:3770-5. [PMID: 11867754 PMCID: PMC122599 DOI: 10.1073/pnas.052710299] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
It has been argued that genetic instability is required to generate the myriad mutations that fuel tumor initiation and progression and, in fact, patients with heritable cancer susceptibility syndromes harbor defects in specific genes that normally maintain DNA integrity. However, the vast majority of human cancers arise sporadically, in the absence of deficiencies in known "mutator" genes. We used a cII-based mutation detection assay to show that the mean frequency of forward mutations in primary mammary adenocarcinomas arising in mouse mammary tumor virus-c-erbB2 transgenic mice harboring multiple copies of the lambda bacteriophage genome was significantly higher than in aged-matched, wild-type mammary tissue. Analysis of the cII mutational spectrum within the mammary tumor genomic DNA demonstrated a >6-fold elevation in transversion mutation frequency, resulting in a highly unusual inversion of the transition/transversion ratio characteristic of normal epithelium; frameshift mutation frequencies were unaltered. Arising oncogenic point mutations within the c-erbB2 transgene of such tumors were predominantly transversions as well. Data from this model system support the notion that elaboration of a mutator phenotype is a consequential event in breast cancer and suggest that a novel DNA replication/repair gene is a relatively early mutational target in c-erbB2-induced mammary tumorigenesis.
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MESH Headings
- Adenocarcinoma/genetics
- Adenocarcinoma/virology
- Aging
- Amino Acid Sequence
- Animals
- Bacteriophage lambda/genetics
- Cell Transformation, Neoplastic/genetics
- DNA Damage/genetics
- DNA Mutational Analysis
- Female
- Fibroblasts
- Gene Frequency/genetics
- Kinetics
- Male
- Mammary Glands, Animal/metabolism
- Mammary Glands, Animal/pathology
- Mammary Neoplasms, Animal/genetics
- Mammary Neoplasms, Animal/virology
- Mammary Tumor Virus, Mouse/physiology
- Mice
- Mice, Transgenic
- Molecular Sequence Data
- Mutagenesis/genetics
- Mutation, Missense/genetics
- Receptor, ErbB-2/genetics
- Receptor, ErbB-2/metabolism
- Transgenes/genetics
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Chan R, Hardy WR, Laing MA, Hardy SE, Muller WJ. The catalytic activity of the ErbB-2 receptor tyrosine kinase is essential for embryonic development. Mol Cell Biol 2002; 22:1073-8. [PMID: 11809799 PMCID: PMC134647 DOI: 10.1128/mcb.22.4.1073-1078.2002] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Activation of the epidermal growth factor receptor (EGFR) family is thought to play a critical role in both embryogenesis and oncogenesis. The diverse biological activities of the EGFR family are achieved through various ligand-receptor and receptor-receptor interactions. One receptor that has been found to play a central role in this signaling network is ErbB-2/Neu, and it is considered the preferred heterodimerization partner for other members of the EGFR family. To assess the importance of the catalytic activity of ErbB-2 in embryonic development, we have generated mice expressing a kinase-dead erbB-2 cDNA under the transcriptional control of the endogenous promoter. Here, we show that mice homozygous for the kinase-dead erbB-2 allele die at midgestation and display the same spectrum of embryonic defects seen in erbB-2 knockout mutants. These observations suggest that the catalytic activity of ErbB-2 is essential for normal embryonic development.
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Lee FY, Chu W, Chan R, Leung YF, Liu KH, Ng SM, Lai PB, Metreweli C, Lau WY. Incidence of deep vein thrombosis after colorectal surgery in a Chinese population. ANZ J Surg 2001; 71:637-40. [PMID: 11736821 DOI: 10.1046/j.0004-8682.2001.02227.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
INTRODUCTION Contemporary studies indicate that the incidence of deep vein thrombosis (DVT) is increasing in the Asian population. The present study aims to evaluate the incidence of postoperative DVT in Chinese patients undergoing surgery for colorectal malignancies. METHODS Fifty-one consecutive patients with carcinoma of the rectum or sigmoid colon scheduled for resection were included in the study. None of the study subjects were given any form of DVT prophylaxis. Serial duplex ultrasound of both lower limbs were examined in the preoperative and postoperative periods. RESULTS Three patients were excluded from the study because of the presence of DVT noted preoperatively. A total of 20/48 (41.7%) patients developed asymptomatic calf vein thrombosis. One out of 20 patients required anticoagulation because of thrombus propagation. None of the subjects showed signs or symptoms of DVT or pulmonary embolism. A total of 7/20 thrombi resolved completely at 4 weeks after operation. Only old age and smoking were identified as being associated with a higher incidence of DVT. Disseminated disease, type of operation, duration of operation and postoperative complications did not appear to be risk factors for DVT. CONCLUSION A high incidence of asymptomatic calf vein thrombosis occurred after colorectal surgery for malignancies in Chinese. The majority did not progress even without anticoagulation.
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137
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Lam AK, Chan R, Pang PC. The repeatability and accuracy of axial length and anterior chamber depth measurements from the IOLMaster . Ophthalmic Physiol Opt 2001; 21:477-483. [PMID: 11727876 DOI: 10.1016/s0275-5408(01)00016-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
BACKGROUND Axial length and anterior chamber depth have been measured clinically using conventional ultrasound biometry. Recently, a non-contact device has become available to measure these parameters. This study evaluated the repeatability and accuracy of this device. METHODS The axial length and anterior chamber depth were measured by two practitioners on a group of young subjects using the IOLMaster followed by a conventional ultrasound biometer operated by a third practitioner. The accommodation was controlled in ultrasound biometry through a full correction on the non-measured eye and a distant fixation target. RESULTS There was good repeatability and accuracy of axial length assessment. The mean difference between the IOLMaster and ultrasound biometry was -0.099 mm, with 95% limits of agreement between 0.66 and -0.85 mm. The axial length was slightly shorter from the IOLMaster and the difference was not significant. The anterior chamber depth was repeatable but was shown to be deeper than the ultrasound results. The mean difference in anterior chamber depth between the IOLMaster and ultrasound biometry was 0.15 mm, with 95% limits of agreement between 0.34 and -0.03 mm. It is suggested that the former device is not measuring the axial anterior chamber depth. CONCLUSIONS The IOLMaster is a non-contact 'optical' A-scan which is simple to use and good for axial length assessment. The anterior chamber depth assessment should be further evaluated.
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138
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Chan R, He Y, Haque A, Zwischenberger J. Computed tomographic-pathologic correlation of gross tumor volume and clinical target volume in non-small cell lung cancer: a pilot experience. Arch Pathol Lab Med 2001; 125:1469-72. [PMID: 11698004 DOI: 10.5858/2001-125-1469-ctpcog] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
CONTEXT Computed tomographic (CT) scan data are used regularly in radiation treatment planning for patients with lung cancer. To our knowledge, the relationship of the CT images of tumors and their corresponding microscopic extent has not yet been studied in detail. OBJECTIVE To correlate tumor sizes on CT with tumor sizes measured microscopically (ie, the gross tumor volume [GTV]-clinical target volume margin) in non-small cell lung cancers. DESIGN Prospective pilot study. SETTING Single institution. PATIENTS Patients with operable non-small cell lung cancer were identified preoperatively. INTERVENTIONS Once the surgical specimen was available, it was oriented with the surgeon and the pathologist. Seven whole-mount, cross-sectional histologic glass slides were made from 5 tumors using formalin fixation and hematoxylin-eosin staining. The pathologist then outlined the cancer-containing area under the microscope (Micro-GTV) and the area of surrounding inflammatory response (Micro-GTV + inflammation). Preoperative CT scans were used for outlining tumor on the corresponding slice (CT-GTV). MAIN OUTCOME MEASURES Correlation of the areas of Micro-GTV, Micro-GTV + inflammation, and CT-GTV was performed. RESULTS There was an obvious trend that the CT-GTV was bigger than the Micro-GTV, except in specimen 1, in which the 2 areas were about equal. However, on comparing the values for the CT-GTV and the Micro-GTV + inflammation, the difference between the 2 areas became smaller. CONCLUSIONS Modern CT scans might overestimate the GTV in non-small cell lung cancer. The GTV-clinical target volume margin could actually be zero or even a negative value. The findings in this small study are interesting and provoking. Further study with a larger number of patients and more rigid quality control is warranted to confirm our findings.
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Lam AK, Chan R, Pang PC. The repeatability and accuracy of axial length and anterior chamber depth measurements from the IOLMaster . Ophthalmic Physiol Opt 2001; 21:477-83. [PMID: 11727876 DOI: 10.1046/j.1475-1313.2001.00611.x] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Axial length and anterior chamber depth have been measured clinically using conventional ultrasound biometry. Recently, a non-contact device has become available to measure these parameters. This study evaluated the repeatability and accuracy of this device. METHODS The axial length and anterior chamber depth were measured by two practitioners on a group of young subjects using the IOLMaster followed by a conventional ultrasound biometer operated by a third practitioner. The accommodation was controlled in ultrasound biometry through a full correction on the non-measured eye and a distant fixation target. RESULTS There was good repeatability and accuracy of axial length assessment. The mean difference between the IOLMaster and ultrasound biometry was -0.099 mm, with 95% limits of agreement between 0.66 and -0.85 mm. The axial length was slightly shorter from the IOLMaster and the difference was not significant. The anterior chamber depth was repeatable but was shown to be deeper than the ultrasound results. The mean difference in anterior chamber depth between the IOLMaster and ultrasound biometry was 0.15 mm, with 95% limits of agreement between 0.34 and -0.03 mm. It is suggested that the former device is not measuring the axial anterior chamber depth. CONCLUSIONS The IOLMaster is a non-contact 'optical' A-scan which is simple to use and good for axial length assessment. The anterior chamber depth assessment should be further evaluated.
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Davies SJ, Lum SK, Chan R, Wang LK. Evolution of myrmecophytism in western Malesian Macaranga (Euphorbiaceae). Evolution 2001; 55:1542-59. [PMID: 11580014 DOI: 10.1111/j.0014-3820.2001.tb00674.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Plants inhabited by ants (myrmecophytes) have evolved in a diversity of tropical plant lineages. Macaranga includes approximately 300 paleotropical tree species; in western Malesia there are 26 myrmecophytic species that vary in morphological specializations for ant association. The origin and diversification of myrmecophytism in Macaranga was investigated using phylogenetic analyses of morphological and nuclear ITS DNA characters and studies of character evolution. Despite low ITS variation, the combined analysis resulted in a well-supported hypothesis of relationships. Mapping myrmecophytism on all most parsimonious trees resulting from the combined analysis indicated that the trait evolved independently between two and four times and was lost between one and three times (five changes). This hypothesis was robust when tested against trees constrained to have three or fewer evolutionary transformations, although increased taxon sampling for the ITS analysis is required to confirm this. Mapping morphological traits on the phylogeny indicated that myrmecophytism was not homologous among lineages; each independent origin involved a suite of different specializations for ant-plant association. There was no evidence that myrmecophytic traits underwent sequential change through evolution; self-hollowing domatia evolved independently from ant-excavated domatia, and different food-body production types evolved in different lineages. The multiple origins of myrmecophytism in Macaranga were restricted to one small, exclusively western Malesian lineage of an otherwise large and nonmyrmecophytic genus. Although the evolution of aggregated food-body production and the formation of domatia coincided with the evolution of myrmecophytism in all cases, several morphological, ecological, and biogeographic factors appear to have facilitated and constrained this radiation of ant-plants.
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Lowrey TK, Quinn CJ, Taylor RK, Chan R, Kimball RT, De Nardi JC. Molecular and morphological reassessment of relationships within the Vittadinia group of Astereae (Asteraceae). AMERICAN JOURNAL OF BOTANY 2001; 88:1279-1289. [PMID: 11454628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Morphological and ITS (internal transcribed spacer) sequence data for 40 species of the Austral-Pacific genera Camptacra, Kippistia, Minuria, Peripleura, Tetramolopium, and Vittadinia as well as one semiherbaceous species of Olearia were subjected to cladistic analysis, separately and together. Minuria, Peripleura, and Tetramolopium are paraphyletic as currently defined. Tetramolopium vagans from Australia appears to represent an undescribed genus. Both Kippistia suadefolia and Peripleura diffusa show close affinity to Minuria species, and Minuria macrorhiza appears to contain two distinct but closely related species. Vittadinia and the remaining species of Tetramolopium and Peripleura form a strong affinity group. The distribution of indels and the combined analysis each provide evidence that the Hawaiian and Cook Island species of Tetramolopium are descended from New Guinea species. The combined analysis also suggests that the Cook Island species T. mitiaroense is sister to the Hawaiian clade. Olearia arguta groups strongly with Camptacra and shows no close affinity with either of the arborescent species of Olearia used to root these analyses. Marked homoplasy among morphological characters indicates why generic delimitation in the group has been problematic.
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143
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Chan R. The effects of electrolyte concentration and pH on protein aggregation and deposition: critical flux and constant flux membrane filtration. J Memb Sci 2001. [DOI: 10.1016/s0376-7388(00)00645-1] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Sheiman RG, Chan R, Matthews JB. Percutaneous treatment of a pancreatic fistula after pancreaticoduodenectomy. J Vasc Interv Radiol 2001; 12:524-6. [PMID: 11287543 DOI: 10.1016/s1051-0443(07)61895-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Breakdown of the pancreaticojejunal anastomosis after a Whipple procedure is reported to occur in as many as 15% of cases. Intraoperative placement of a drain adjacent to the anastomosis is performed to allow the creation of a controlled pancreaticocutaneous fistula in the event of an anastomotic disruption. The authors present a case of successful percutaneous treatment of a disrupted pancreaticojejunal anastomosis. This was achieved with use of the resulting pancreaticocutaneous fistula for access to restore internal drainage, followed by fistula occlusion with use of gelatin pledgets.
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Wang J, Cheng J, Chan R, Tseng L, Chou K, Tang K, Chung Lee K, Lo Y, Wang J, Jan C. The anti-anginal drug fendiline increases intracellular Ca(2+) levels in MG63 human osteosarcoma cells. Toxicol Lett 2001; 119:227-33. [PMID: 11246176 DOI: 10.1016/s0378-4274(01)00262-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The effect of fendiline, an anti-anginal drug, on cytosolic free Ca(2+) levels ([Ca(2+)](i)) in MG63 human osteosarcoma cells was explored by using fura-2 as a Ca(2+) indicator. Fendiline at concentrations between 1 and 200 microM increased [Ca(2+)](i) in a concentration-dependent manner and the signal saturated at 100 microM. The Ca(2+) signal was inhibited by 65+/-5% by Ca(2+) removal and by 38+/-5% by 10 microM nifedipine, but was unchanged by 10 microM La(3+) or verapamil. In Ca(2+)-free medium, pre-treatment with 1 microM thapsigargin (an endoplasmic reticulum Ca(2+) pump inhibitor) to deplete the endoplasmic reticulum Ca(2+) store inhibited fendiline-induced intracellular Ca(2+) release. The Ca(2+) release induced by 50 microM fendiline appeared to be independent of IP(3) because the [Ca(2+)](i) increase was unaltered by inhibiting phospholipase C with 2 microM U73122. Collectively, the results suggest that in MG63 cells fendiline caused an increase in [Ca(2+)](i) by inducing Ca(2+) influx and Ca(2+) release in an IP(3)-independent manner.
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Chan R, Khoo L, Ho TH, Koh CF, Lee IW, Yam KL, Chandra D, Pang M, Chow V. A comparative study of cervical cytology, colposcopy and PCR for HPV in female sex workers in Singapore. Int J STD AIDS 2001; 12:159-63. [PMID: 11231868 DOI: 10.1258/0956462011916956] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
This study examined the prevalence of human papillomavirus (HPV) infection in a cohort of female sex workers in Singapore. HPV infection was diagnosed by clinical examination, Papanicolaou (Pap) smears, histology and polymerase chain reaction (PCR). One hundred and eighty-seven female sex workers who came for their routine medical screening were enrolled into the study. PCR was positive for HPV in 27 (14.4%), 20 of these had a single HPV type detected, while 7 had multiple types of HPV detected. The most common HPV types identified were types 16, 58 and 18. In conclusion, HPV infection is moderately prevalent among sex workers as tested by PCR, but routine screening with Pap smears does not appear to be a sensitive method of diagnosis for HPV infection.
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McGettigan P, Golden J, Fryer J, Chan R, Feely J. Prescribers prefer people: The sources of information used by doctors for prescribing suggest that the medium is more important than the message. Br J Clin Pharmacol 2001; 51:184-9. [PMID: 11259994 PMCID: PMC2014444 DOI: 10.1111/j.1365-2125.2001.01332.x] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
AIMS The sources of prescribing information are legion but there is little knowledge about which are actually used in practice by doctors when prescribing. The aims of this study were to determine the sources of prescribing information considered important by doctors, establish which were used in practice, and investigate if hospital and primary care physicians differed in their use of the sources. METHODS Two hundred general practitioners (GPs) and 230 hospital doctors were asked to rate information sources in terms of their importance for prescribing 'old' and 'new' drugs, and then to name the source from which information about the last new drug prescribed was actually derived. RESULTS Among 108 GPs, the Drugs and Therapeutics Bulletin and medical journal articles were most frequently rated as important for information on both old and new drugs while pharmaceutical representatives and hospital/consultant recommendations were more important for information on new drugs, as opposed to old. In practice, information on the last new drug prescribed was derived from pharmaceutical representatives in 42% of cases and hospital/consultant recommendations in 36%, with other sources used infrequently. Among 118 hospital doctors, the British National Formulary (BNF) and senior colleagues were of greatest theoretical importance. In practice, information on the last new drug prescribed was derived from a broad range of sources: colleagues, 29%; pharmaceutical representatives, 18%; hospital clinical meetings, 15%; journal articles, 13%; lectures, 10%. GPs and hospital doctors differed significantly in their use of pharmaceutical representatives (42% vs 18%) and colleagues (7% vs 29%) as sources of prescribing information (P < 0.0001 for both). CONCLUSIONS The sources most frequently rated important in theory were not those most used in practice, especially among GPs. Both groups under-estimated the importance of pharmaceutical representatives. Most importantly, the sources of greatest practical importance were those involving the transfer of information through the medium of personal contact.
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Kang S, Chan R, White L, Waksman R. Analysis of intracoronary brachytherapy dosimetry using intravascular ultrasound-based 3-D treatment planning system. CARDIOVASCULAR RADIATION MEDICINE 2001; 2:55. [PMID: 11068268 DOI: 10.1016/s1522-1865(00)00059-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Vodovotz Y, Kollum M, Chan R, Waksman R. T-cell infiltration and apoptosis following intracoronary radiation for the prevention of restenosis in porcine coronaries. CARDIOVASCULAR RADIATION MEDICINE 2001; 2:58-59. [PMID: 11068280 DOI: 10.1016/s1522-1865(00)00070-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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