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Stermitz FR, Belofsky GN, Ng D, Singer MC. Quinolizidine alkaloids obtained byPedicularis semibarbata (Scrophulariaceae) fromLupinus fulcratus (Leguminosae) fail to influence the specialist herbivoreEuphydryas editha (Lepidoptera). J Chem Ecol 2013; 15:2521-30. [PMID: 24271594 DOI: 10.1007/bf01014728] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/1988] [Accepted: 01/03/1989] [Indexed: 10/25/2022]
Abstract
Pedicularis semibarbata is apparently an obligate hemiparasite of coniferous trees. It is also a facultative parasite ofLupinus fulcratus from which we find that it obtains quinolizidine alkaloids, principally α-isolupanine. As a result, a single population ofP. semibarbata contains both alkaloidrich and alkaloid-free plants. The butterflyEuphydryas editha naturally oviposits on both plant types. This butterfly population, which is the principal herbivore attackingP. semibarbata at this site, is known to contain two morphs. Individuals of a specialist morph discriminate when ovipositing among individualP. semibarbata plants and produce offspring that survive better on accepted than on rejected plants. Those of a generalist morph accept allP. semibarbata plants and produce offspring that survive equally well on plants accepted or rejected by the discriminating morph. Because of the existence of this complex variation among the butterflies, the presence of naturally laid eggs on alkaloid-containing plants still leaves the possibility that the alkaloids may defend the plants against the specialist morph. In experiments on both oviposition preference and larval performance in early instars, we failed to detect any correlation between alkaloid content of a plant and either its acceptability to or suitability for the discriminating morph of the insect. Alkaloid presence in the host-plant population, achieved through root parasitism, is currently neither subject to strong insect-mediated selection nor a major cause of selection on the insects.
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Kadivar K, Malloch L, Adonsou-Hoyi Y, Ng D, Lavoie S, Pulido K, Kim J. Would CLSI M53-A have helped in the diagnosis of HIV in Canada? Results of the performance of Canadian laboratories participating in a recent NLHRS proficiency testing panel containing HIV-1 antigen positive (antibody negative) and HIV-2 samples. J Clin Virol 2013; 58:303-5. [PMID: 23890809 DOI: 10.1016/j.jcv.2013.04.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Revised: 03/25/2013] [Accepted: 04/08/2013] [Indexed: 01/15/2023]
Abstract
INTRODUCTION The Clinical and Laboratory Standards Institute recently published M53-A, Criteria for Laboratory Testing and Diagnosis of Human Immunodeficiency Virus (HIV) Infection; Approved Guideline (2011), which includes a state of the art algorithm for identifying HIV-1 acute and HIV-2 infections. To assess the ability of Canadian laboratories to detect these sample types and the impact of M53-A, the National Laboratory for HIV Reference Services distributed a special proficiency testing panel. METHODS HIVS425-2012Nov22 was sent to 42 laboratories across Canada. It contained one HIV negative sample (B), two HIV-1 positive samples (A and E), one HIV-2 positive sample (C) and one HIV-1/2 antibody negative-HIV-1 antigen positive sample (D). Data was collected and analyzed using DigitalPT; a standardized on-line tool. RESULTS Forty-one laboratories returned results. Sample B (HIV negative) was identified by 95% of laboratories (39/41) and samples A and E (HIV-1 positive) by 98% (40/41). No laboratory identified sample C as HIV-2 positive, although 85% (35/41) detected reactivity prompting a referral for further testing. The remaining laboratories identified sample C as HIV-1 positive (4), indeterminate (1) or gave no final status (1). Sample D (HIV antibody negative-antigen positive) was correctly identified by two laboratories as HIV-1 antigen positive while 78% (32/41) detected reactivity, recommending further testing. One laboratory did not provide a final status. Alarmingly, six laboratories called this sample HIV negative. CONCLUSION Although there is a high quality of HIV testing across Canada, introduction of the M53-A guideline would further improve the ability of laboratories to diagnose HIV-1 acute and HIV-2 infection.
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Ng D, Ferrusi I, Khong H, Earle C, Trudeau M, Marshall D, Leighl N. Abstract P5-18-14: Cardiac monitoring during adjuvant trastuzumab therapy for breast cancer. Cancer Res 2012. [DOI: 10.1158/0008-5472.sabcs12-p5-18-14] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background: Adjuvant trastuzumab improves survival in HER2+ breast cancer. Cardiac toxicity is an important potential side effect. We report real world practice patterns in cardiac monitoring and outcomes during adjuvant trastuzumab therapy in Ontario.
Methods: A cohort of female patients diagnosed with early breast cancer from Jan 1, 2006 to Dec 31, 2007 and who received trastuzumab was identified retrospectively through linkage of provincial administrative and registry databases. Demographic, pathology, treatment, hospital admissions, claims for cardiac tests (MUGA or echo), and outcomes were extracted for individuals. Pre-existing cardiac disease (CHF, MI, angina, valve disorder, arrhythmia, cardiomyopathy) and risk factors (diabetes, lipid disorder, hypertension) were classified using ICD-10 codes. Appropriate cardiac monitoring definitions were based on published trials and expert opinion. Symptomatic cardiac toxicity was defined as a physician claim or hospital admission with a cardiac diagnosis occurring within 2 years of the first trastuzumab dose. Asymptomatic cardiac toxicity was defined as temporary or permanent cessation of trastuzumab with additional cardiac tests. Patients were categorized into treatment groups: G1 received at least 17 doses (standard 3-weekly administration for 51 weeks) with no complications; G2 stopped early for non-cardiac reasons (no additional cardiac tests); G3 had symptomatic or asymptomatic cardiac toxicity. Analyses of patient, treatment and system factors possibly affecting cardiac monitoring and toxicity were performed.
Results: 1,357 patients diagnosed with early breast cancer between 2006–7 received trastuzumab (median = 18 doses). 77% received anthracyclines; 4.1% had at least 1 cardiac risk factor. The majority (91%) had a baseline cardiac test, including 96% of those with cardiac risks. Geographic region was associated with baseline testing, but multivariable analysis of other factors including urbanicity, left lateral radiation, age, income, and anthracycline use, did not explain the variation in baseline testing patterns. The majority, 81%, had ≥3 cardiac tests, 62.2% had ≥4. Cardiac monitoring was deemed appropriate in 80.7% of patients without cardiac events, and 73.4% in those with symptomatic or asymptomatic cardiac events. Multivariable analysis revealed duration of trastuzumab to be the most significant factor associated with appropriateness of cardiac monitoring (G1 - OR 0.62, p = 0.018, 95% CI 0.45–0.92; G3 - OR 4.56, p < 0.001, 95% CI 2.47–8.42). 297 patients (22%) experienced symptomatic (7%) or asymptomatic (15%) cardiac toxicity. Duration of trastuzumab (<17 doses; OR 6.47, p < 0.001, 95% CI 4.79–8.75) was associated with cardiac toxicity.
Conclusions: The majority of early breast cancer patients that received adjuvant trastuzumab in Ontario between 2006–7 had cardiac monitoring consistent with clinical trials. Cardiac toxicity in this real world population, as defined by our database analysis, was unexpectedly higher than reported in trials. Shorter duration of trastuzumab was associated with cardiac toxicity, likely reflecting the practice of stopping trastuzumab in the presence of cardiac events.
Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-18-14.
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Ng D, Klein W, Tran R, Riddle-Branske D, Luna PJ, Nguyen HB. Combination therapy with high-frequency oscillatory ventilation, neuromuscular blockade, inhaled nitric oxide and prone position in acute respiratory distress syndrome with refractory hypoxaemia. Anaesth Intensive Care 2012; 40:898-899. [PMID: 22934878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
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Tran N, Skafidas E, Yang J, Bai S, Fu M, Ng D, Halpern M, Mareels I. A prototype 64-electrode stimulator in 65 nm CMOS process towards a high density epi-retinal prosthesis. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2012; 2011:6729-32. [PMID: 22255883 DOI: 10.1109/iembs.2011.6091660] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
This paper presents a highly flexible 64-electrode stimulator using 65 nm CMOS process fabricated as a stage towards a 1024-electrode epi-retinal prosthesis, which aims to restore partial vision in patients suffering from eye diseases such as retinitis pigmentosa (RP) and age-related macular degradation (AMD). The stimulator drives 64 electrodes with many flexible features, which are necessary before making a complete 1024-electrode implant chip. Each electrode driver can provide a bi-phasic stimulus current with fully programmable parameters such as amplitude, pulse duration, inter-phase gap, and stimulation rate. The electrode driver operates in an alternately pull-push manner with only one current source working at a time, which helps reduce headroom voltage while controlling charge balance at the active electrode. The stimulator varies both stimulus current amplitude and stimulation rate to represent phosphene brightness. The stimulus current amplitude starts from the tissue depolarization threshold with 64 different levels. The selection of active and return electrodes is arbitrary, any electrodes and any number of them can be selected at any time. The power consumption of the stimulator is 400 μW excluding the stimulus power. Measurement results verify correct operation. The stimulator is easily scaled up to drive 1024 electrodes.
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Ng D, De Silva RK, Smit R, De Silva H, Farella M. Facial attractiveness of skeletal Class II patients before and after mandibular advancement surgery as perceived by people with different backgrounds. Eur J Orthod 2012; 35:515-20. [DOI: 10.1093/ejo/cjs028] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Xie Z, Hoang M, Duong T, Ng D, Dao B, Gray S. Sol–gel derived poly(vinyl alcohol)/maleic acid/silica hybrid membrane for desalination by pervaporation. J Memb Sci 2011. [DOI: 10.1016/j.memsci.2011.08.036] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Chung AD, Ng D, Wang L, Garraway C, Bezjak A, Nyhof-Young J, Wong RKS. Informational stories: a complementary strategy for patients and caregivers with brain metastases. ACTA ACUST UNITED AC 2011; 16:33-9. [PMID: 19526083 PMCID: PMC2695708 DOI: 10.3747/co.v16i3.397] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Objective We compared the efficacy of a story-based writing style with that of a fact-based writing style for educational material on brain metastases. Methods Identical informational content on four topics—radiation therapy, side effects, steroid tapering, and palliative care—was constructed into equivalent story-based and fact-based materials. The content and reader preference for style were evaluated using a questionnaire of 20 + 1 items. Cancer patients and caregivers were invited to evaluate the materials. Results A total of 47 participants completed the questionnaire. The recorded preferences for facts, stories, or both were 42%, 7%, and 51% respectively (p = 0.0004). The fact-based materials were rated superior in providing factual information (for example, discussion of treatment, side effects) and selected general characteristics (clarity of information, for instance). A rating trend suggested that story-based materials were superior in describing “how it feels to have brain metastases” (21/40 fact-based vs. 26/43 story-based) and “how brain metastases affected a spouse” (17/41 fact-based vs. 21/47 story-based), and in being “sensitive to the frustrations of a patient with brain metastases” (25/40 fact-based vs. 30/44 story-based). Conclusions Half the participants preferred to read both fact-based and story-based materials. A combined story-based and fact-based educational resource may be more effective in conveying sensitive information and should be further investigated.
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Wilfley D, Berkowitz R, Goebel-Fabbri A, Hirst K, Ievers-Landis C, Lipman TH, Marcus M, Ng D, Pham T, Saletsky R, Schanuel J, Van Buren D. Binge eating, mood, and quality of life in youth with type 2 diabetes: baseline data from the today study. Diabetes Care 2011; 34:858-60. [PMID: 21357794 PMCID: PMC3064041 DOI: 10.2337/dc10-1704] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE The current study examines the prevalence of binge eating and its association with adiposity and psychosocial functioning in a large, diverse sample of youth with type 2 diabetes. RESEARCH DESIGN AND METHODS In the TODAY study, 678 (mean age 14.0 years; 64.9% girls) of the 704 youth randomized to the study completed a self-report measure of eating disorder symptoms and were categorized as nonovereaters, overeaters, subclinical binge eaters, or clinical binge eaters. RESULTS Youth with clinical (6%) and subclinical (20%) levels of binge eating had significantly higher levels and rates of extreme obesity, global eating disorder and depressive symptoms, and impaired quality of life. CONCLUSIONS These findings highlight the importance of evaluating youth with type 2 diabetes for the presence of binge eating. Future research is needed to determine the cumulative effects of disordered eating, obesity, and psychosocial distress on adherence to lifestyle change recommendations and longitudinal response to treatment.
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Carreto-Vázquez V, Hernández I, Ng D, Rogers W, Mannan M. Inclusion of pressure hazards into NFPA 704 instability rating system. J Loss Prev Process Ind 2010. [DOI: 10.1016/j.jlp.2009.05.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Tran N, Yang J, Bai S, Ng D, Halpern M, Grayden DB, Skafidas E, Mareels I. A fully flexible stimulator using 65 nm CMOS process for 1024-electrode epi-retinal prosthesis. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2009; 2009:1643-1646. [PMID: 19964765 DOI: 10.1109/iembs.2009.5334239] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
This paper presents a fully flexible stimulator using 65 nm CMOS process for a 1024-electrode epi-retinal prosthesis. The stimulator can select any number of electrodes at any time and also supports both mono-polar and multi-polar stimulation. Furthermore, the stimulator supports a wide range of stimulus parameters. A novel feature is that the electrode driver operates in an alternately pull-push manner, which helps reduce headroom voltage while guaranteeing charge balance at the active electrode. The use of positive supplies instead of both positive and negative supplies simplifies CMOS circuit design. The current distribution between two nearby simultaneously active electrode groups was investigated and measurement result showed a maximum current crosstalk of 8%.
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McGoldrick R, Ng D, Sawyer A, Mackey S, Vadodaria S, Powell B. Malignant melanoma re-excision specimens: is there a need for histopathological analysis? J Plast Reconstr Aesthet Surg 2008; 61:983-4. [DOI: 10.1016/j.bjps.2007.11.051] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2006] [Revised: 11/19/2007] [Accepted: 11/21/2007] [Indexed: 11/16/2022]
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Alagappan K, McGowan J, DeClaro D, Ng D, Silverman RA. Tetanus antibody protection among HIV-infected US-born patients and immigrants. Int J Emerg Med 2008; 1:123-6. [PMID: 19384663 PMCID: PMC2657240 DOI: 10.1007/s12245-008-0020-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
INTRODUCTION Public health initiatives to immunize children and adults have effectively reduced the number of tetanus cases in the USA. However, in the Third National Health and Nutrition Examination Survey (NHANES III), immigrants from Mexico had a 67% nonprotective anti-tetanus antibody (ATA) level. Less work has been conducted among other vulnerable populations such as human immunodeficiency virus (HIV)-infected patients. The objective of this study was to measure ATA levels among the HIV immigrant population compared with US-born HIV-infected patients. METHODS A convenience sample of 158 HIV-infected individuals was recruited to determine the levels of ATA. A nonprotective level of ATA was defined as below 0.15 IU/ml. RESULTS Among the HIV-infected patients, 72% (114/158) were born in the USA. A total of 17% (27/158) lacked protective levels of ATA. A total of 6.1% (7/114) of those born in the USA lacked protection, compared to 45% (20/44) born outside the USA (p < 0.0001). CONCLUSION The results illustrate that the country of birth is an important predictor of ATA protection, even among HIV-infected patients.
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Howe TC, Padhy AK, Loke K, Magsombol B, Ng D, Goh A. Role of Tc-99m DMSA (V) scanning and serum calcitonin monitoring in the management of medullary thyroid carcinoma. Singapore Med J 2008; 49:19-22. [PMID: 18204763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
INTRODUCTION Medullary thyroid carcinoma (MTC) is a rare disease. Serum calcitonin levels and Tc-99m DMSA (V) scans are used in the follow-up of these patients after surgical resection. We present our experience in the follow-up of these patients at a tertiary institution. METHODS A retrospective review of the medical records was performed. Patients with histologically-proven MTC, and who had serum calcitonin assays and DMSA (V) scans in their postoperative follow-up, were included. RESULTS There were 17 patients with 56 DMSA (V) scans. Four out of seven patients with elevated preoperative calcitonin measurements had calcitonin normalisation within six months of surgery, and have remained disease-free. Two patients had persistently elevated calcitonin levels after six months, which predated positive DMSA (V) scans. Results of DMSA (V) scans and serum calcitonin levels were concordant in 38 of 48 instances (79.2 percent) and discordant in 10 of 48 instances (20.8 percent). Sensitivity of DMSA (V) scans for detecting recurrence was 71.4 percent. There were no false-positive scans. CONCLUSION Serum calcitonin level is a sensitive and specific indicator of disease recurrence in postoperative follow-up of patients with MTC. Early (within six months) normalisation of calcitonin levels postsurgery may predict subsequent disease-free status. Discordant results between serum calcitonin levels and DMSA (V) scans may be due to undetectable lesions and follow-up scans or alternative radionuclide imaging may be required.
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Mailis-Gagnon A, Yegneswaran B, Lakha SF, Nicholson K, Steiman AJ, Ng D, Papagapiou M, Umana M, Cohodarevic T, Zurowski M. Pain characteristics and demographics of patients attending a university-affiliated pain clinic in Toronto, Ontario. Pain Res Manag 2007; 12:93-9. [PMID: 17505570 PMCID: PMC2670716 DOI: 10.1155/2007/658762] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND Pain clinics tend to see more complex chronic pain patients than primary care settings, but the types of patients seen may differ among practices. OBJECTIVE The aim of the present observational study was to describe the pain and demographic characteristics of patients attending a university-affiliated tertiary care pain clinic in Toronto, Ontario. METHODS Data were collected on 1242 consecutive new patients seen over a three-year period at the Comprehensive Pain Program in central Toronto. RESULTS Musculoskeletal problems affecting large joints and the spine were the predominant cause of pain (more prevalent in women), followed by neuropathic disorders (more prevalent in men) in patients with recognizable physical pathology. The most affected age group was in the 35- to 49-year age range, with a mean pain duration of 7.8 years before the consultation. While 77% of the Comprehensive Pain Program patients had relevant and detectable physical pathology for pain complaints, three-quarters of the overall study population also had significant associated psychological or psychiatric comorbidity. Women, in general, attended the pain clinic in greater numbers and had less apparent physical pathology than men. Finally, less than one in five patients was employed at the time of referral. CONCLUSIONS The relevance of the data in relation to other pain clinics is discussed, as well as waiting lists and other barriers faced by chronic pain patients, pain practitioners and pain facilities in Ontario and Canada.
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Ng D, Huang PY, Jeng YR, Liang H. Nanoparticle Removal Mechanisms during Post-CMP Cleaning. ACTA ACUST UNITED AC 2007. [DOI: 10.1149/1.2739817] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Kitchen AJ, Trivedi P, Ng D, Mokbel K. Is there a link between breast cancer and abortion: a review of the literature. INTERNATIONAL JOURNAL OF FERTILITY AND WOMEN'S MEDICINE 2005; 50:267-71. [PMID: 16526417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
The hormonal changes that take place in pregnancy cause breast tissue to proliferate and differentiate. Abortion interrupts this process and may leave the proliferated, undifferentiated breast tissue at higher risk of carcinogenesis. This review explains the supposed difference in effects of induced and spontaneous abortion upon the breast tissue and examines the literature for a link with breast cancer. Additional subcategories examined include parity, number of abortions, gestation, and maternal age at abortion. A comparison of retrospective and prospective studies is made and possible sources of bias are identified. There is no evidence to support a link between spontaneous abortion and breast cancer. Absence of a link with induced abortion is less clear, and further research should concentrate on investigating any relationship. We suggest that prospective research is used, with point of entry at first termination.
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Rostagno A, Tomidokoro Y, Lashley T, Ng D, Plant G, Holton J, Frangione B, Revesz T, Ghiso J. Chromosome 13 dementias. Cell Mol Life Sci 2005; 62:1814-25. [PMID: 15968464 PMCID: PMC11139122 DOI: 10.1007/s00018-005-5092-5] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The importance of cerebral amyloid deposition in the mechanism of neurodegeneration is still debatable. Classic arguments are usually centered on amyloid beta(Abeta) and its role in the neuronal loss characteristic of Alzheimer's disease, the most common form of human cerebral amyloidosis. Two non-Abeta cerebral amyloidoses, familial British and Danish dementias (FBD and FDD), share many aspects of Alzheimer's disease, including the presence of neurofibrillary tangles, parenchymal preamyloid and amyloid deposits, cerebral amyloid angiopathy and a variety of amyloid-associated proteins and inflammatory components. Both early-onset conditions are linked to specific mutations at or near the stop codon of the chromosome 13 gene BRI2 that cause generation of longer-than-normal protein products. Furin-like processing of these longer precursors releases two de novo-created peptides, ABri and ADan, which deposit as amyloid fibrils in FBD and FDD, respectively. Due to the similar pathology generated by completely unrelated amyloid subunits, FBD and FDD, collectively referred to as chromosome 13 dementias, constitute alternative models for studying the role of amyloid deposition in the mechanism of neuronal cell death.
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Cunningham M, Lin M, Buragina C, Milton S, Ng D, Hsu C, Keoshkerian B. Maximizing polymer livingness in nitroxide-mediated miniemulsion polymerizations. POLYMER 2005. [DOI: 10.1016/j.polymer.2004.11.038] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Song YC, Jin S, Louie H, Ng D, Lau R, Zhang Y, Weerasekera R, Al Rashid S, Ward LA, Der SD, Chan VL. FlaC, a protein of Campylobacter jejuni TGH9011 (ATCC43431) secreted through the flagellar apparatus, binds epithelial cells and influences cell invasion. Mol Microbiol 2004; 53:541-53. [PMID: 15228533 DOI: 10.1111/j.1365-2958.2004.04175.x] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Type III secretion systems identified in bacterial pathogens of animals and plants transpose effectors and toxins directly into the cytosol of host cells or into the extracellular milieu. Proteins of the type III secretion apparatus are conserved among diverse and distantly related bacteria. Many type III apparatus proteins have homologues in the flagellar export apparatus, supporting the notion that type III secretion systems evolved from the flagellar export apparatus. No type III secretion apparatus genes have been found in the complete genomic sequence of Campylobacter jejuni NCTC11168. In this study, we report the characterization of a protein designated FlaC of C. jejuni TGH9011. FlaC is homologous to the N- and C-terminus of the C. jejuni flagellin proteins, FlaA and FlaB, but lacks the central portion of these proteins. flaC null mutants form a morphologically normal flagellum and are highly motile. In wild-type C. jejuni cultures, FlaC is found predominantly in the extracellular milieu as a secreted protein. Null mutants of the flagellar basal rod gene (flgF) and hook gene (flgE) do not secrete FlaC, suggesting that a functional flagellar export apparatus is required for FlaC secretion. During C. jejuni infection in vitro, secreted FlaC and purified recombinant FlaC bind to HEp-2 cells. Invasion of HEp-2 cells by flaC null mutants was reduced to a level of 14% compared with wild type, suggesting that FlaC plays an important role in cell invasion.
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Ng D, Salvio F, Hicks G. Anti-leukotriene agents compared to inhaled corticosteroids in the management of recurrent and/or chronic asthma in adults and children. Cochrane Database Syst Rev 2004:CD002314. [PMID: 15106175 DOI: 10.1002/14651858.cd002314.pub2] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Anti-leukotrienes agents are currently being studied as alternative first line agents to inhaled corticosteroids in mild to moderate chronic asthma. OBJECTIVES To compare the safety and efficacy of anti-leukotriene agents with inhaled glucocorticoids (ICS) and to determine the dose-equivalence of anti-leukotrienes to daily dose of ICS. SEARCH STRATEGY We searched MEDLINE (1966 to Aug 2003), EMBASE (1980 to Aug 2003), CINAHL (1982 to Aug 2003), the Cochrane Airways Group trials register, and the Cochrane Central Register of Controlled Trials (August 2003), abstract books, and reference lists of review articles and trials. We contacted colleagues and international headquarters of anti-leukotrienes producers. SELECTION CRITERIA Randomised controlled trials that compared anti-leukotrienes with inhaled corticosteroids during a minimal 30-day intervention period in asthmatic patients aged 2 years and older. DATA COLLECTION AND ANALYSIS Two reviewers independently assessed the methodological quality or trials and extracted trial data. The primary outcome was the rate of exacerbations requiring systemic corticosteroids. Secondary outcomes included lung function, indices of chronic asthma control, adverse effects and withdrawal rates. MAIN RESULTS 27 trials (including 1 trial testing two protocols) met the inclusion criteria; 13 were of high methodological quality; 20 are published in full-text. All trials pertained to patients with mild to moderate persistent asthma. Only 3 trials focused on children and adolescents. Trial duration varied from 4 to 37 weeks. In most trials, daily dose of ICS was 400 mcg of beclomethasone or equivalent. Patients treated with anti-leukotrienes were 65% more likely to suffer an exacerbation requiring systemic steroids [Relative Risk 1.65; 95% Confidence Interval (CI) 1.36 to 2.00]. Twenty six (95% CI: 17 to 47) patients must be treated with anti-leukotrienes instead of inhaled corticosteroids to cause one extra exacerbation. Significant differences favouring ICS were noted in secondary outcomes where()the improvement in FEV(1) reached 130 mL [13 trials; 95% CI: 50, 140 mL ]. Other significant benefits of ICS were seen for symptoms, nocturnal awakenings, rescue medication use, symptom-free days, and quality of life. Anti-leukotriene therapy was associated with 160% increased risk of withdrawals due to poor asthma control. Twenty nine (95% CI 20 to 48) patients must be treated with anti-leukotrienes instead of inhaled corticosteroids to cause one extra withdrawal due to poor control. Risk of side effects was not different between groups. REVIEWERS' CONCLUSIONS Inhaled steroids at a dose of 400 mcg/day of beclomethasone or equivalent are more effective than anti-leukotriene agents given in the usual licensed doses. The exact dose-equivalence of anti-leukotriene agents in mcg of ICS remains to be determined. Inhaled glucocorticoids should remain the first line monotherapy for persistent asthma.
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Turgay A, Tong L, Ansari R, Khosroshahi H, Ng D, Zafar M, Jagdeo J, Azzopardi P. Age, Gender, Subtype and Comorbidity Relations in 1000 Children and Adolescents with Adhd. Paediatr Child Health 2002. [DOI: 10.1093/pch/7.suppl_a.34ab] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Ng D. Heparin in hypertriglyceridemia: friend or foe? THE JOURNAL OF LABORATORY AND CLINICAL MEDICINE 2001; 138:356-8. [PMID: 11753281 DOI: 10.1067/mlc.2001.119433] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Ng D, Mowrey P, Ragoussis J, Mirza G, Coll E, Di Fazio MP, Turner C, Levin SW. Molecularly defined interstitial tandem duplication 6p case with mild manifestations. AMERICAN JOURNAL OF MEDICAL GENETICS 2001; 103:320-5. [PMID: 11746013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/17/2023]
Abstract
An interstitial tandem duplication of 6p21.1-p22.2 was found in a girl at 11 months of age when she was evaluated for developmental delay. Previous cases reported with partial 6p duplication usually have involved terminal duplications, with breakpoints ranging from 6p11 to 6p25. Our patient exhibits a milder phenotype compared to the previously reported cases in the literature. Features that she has in common with the other cases include craniofacial anomalies, such as broad nasal bridge and bulbous tip, thin lips, incomplete development of the scapha helix bilaterally, mild spastic paraparesis of the lower extremities, gross motor delay, and mild cognitive delays.
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Stephens M, Batres LA, Ng D, Baldassano R. Growth failure in the child with inflammatory bowel disease. SEMINARS IN GASTROINTESTINAL DISEASE 2001; 12:253-62. [PMID: 11726079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
Once considered rare in pediatric practice, chronic inflammatory bowel disease (IBD) is now being recognized with increasing frequency in children of all ages. In IBD, growth failure may be the only clinical presentation; it is imperative to perform a detailed history and physical examination to search for other systemic and gastrointestinal manifestations of the disease. IBD can have a significant impact on linear growth, weight gain, and bone mineralization, and can cause delays in the onset of puberty. Delays in growth and sexual development can be early indicators of disease activity, and assessment of growth and development should be performed frequently. Nutritional therapy is important not only to correct undernutrition, but also as therapy for IBD. Delayed puberty can have a significant impact on the self-esteem of the adolescent patient and diminish final adult height. Loss of bone mineral density is especially significant during a period in which the majority of bone accretion is expected to occur. These issues present unique problems to the gastroenterologist caring for a child or adolescent with IBD and require specific types of monitoring and interventions.
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