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Sathiakumar N, Delzell E, Morrisey MA, Falkson C, Yong M, Chia V, Blackburn J, Arora T, Kilgore ML. Mortality following bone metastasis and skeletal-related events among men with prostate cancer: a population-based analysis of US Medicare beneficiaries, 1999-2006. Prostate Cancer Prostatic Dis 2011; 14:177-83. [PMID: 21403668 DOI: 10.1038/pcan.2011.7] [Citation(s) in RCA: 166] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Information on the impact of bone metastasis and skeletal-related events (SREs) on mortality among prostate cancer patients is limited. Using the linked Surveillance, Epidemiology and End Results (SEER)-Medicare database, we identified men aged 65 years or older diagnosed with prostate cancer between July 1 1999 and December 31 2005 and followed to determine deaths through December 31 2006. We classified subjects as having bone metastasis and SREs as indicated by Medicare claims. Using Cox regression, we estimated mortality hazards ratios (HR) among men with bone metastasis with or without SRE, compared with men without bone metastasis. Among 126,978 men with prostate cancer (median follow-up, 3.3 years), 9746 (7.7%) had bone metastasis at prostate cancer diagnosis (1.7%) or during follow-up (5.9%). SREs occurred in 4296 (44%) men with bone metastasis. HRs for risk of death were 6.6 (95% CI=6.4-6.9) and 10.2 (95% CI=9.8-10.7), respectively, for men with bone metastasis but no SRE and for men with bone metastasis plus SRE, compared with men without bone metastasis. Bone metastasis was associated with mortality among prostate cancer patients. This association appeared to be stronger for bone metastasis plus SRE than for bone metastasis without SRE.
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Research Support, Non-U.S. Gov't |
14 |
166 |
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Blackburn J, Hodgskinson R, Currey JD, Mason JE. Mechanical properties of microcallus in human cancellous bone. J Orthop Res 1992; 10:237-46. [PMID: 1740742 DOI: 10.1002/jor.1100100211] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Until now, the mechanical properties of the microcalluses that form in human cancellous bone have been unexplained. We measured the microhardnesses of microcalluses in cancellous bone, of the trabeculae within the microcalluses, of the trabeculae adjacent to microcalluses, and of trabeculae lacking microcalluses in a human tibia and femur. We observed no important differences between materials at the four different sites. Because the microhardness of bone is very closely related to its stiffness, this finding indicates that microcalluses are likely to stiffen the trabeculae in which they are formed, even though they may surround unhealed fractures of the cancellous trabeculae.
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Blackburn J, Carroll PK, Costello J, O’Sullivan G. Spectra of Xe vii, viii, and ix in the extreme ultraviolet: 4d–mp, nf transitions. ACTA ACUST UNITED AC 1983. [DOI: 10.1364/josa.73.001325] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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42 |
48 |
4
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Ingham KE, Gorrel C, Blackburn J, Farnsworth W. Prevalence of odontoclastic resorptive lesions in a population of clinically healthy cats. J Small Anim Pract 2001; 42:439-43. [PMID: 11570386 DOI: 10.1111/j.1748-5827.2001.tb02497.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The prevalence of odontoclastic resorptive lesions (ORLs) was determined in a clinically healthy cat population (228 cats) using both clinical (oral examination) and radiographic (full-mouth series with intraorally positioned dental film) methods. The overall prevalence rate was 29 per cent (mean age of the cat population 4.9 years). The mandibular third premolars (307, 407) were the most commonly affected tooth and the pattern of ORL development was symmetrical in most cats. The risk of having ORLs was found to increase with increasing age and cats with clinically and radiographically missing teeth were more likely to have the condition. Neutering, gender, age at neutering or mean whole mouth gingivitis index did not affect the prevalence of ORLs.
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Karaballi RA, Nel A, Krishnan S, Blackburn J, Brosseau CL. Development of an electrochemical surface-enhanced Raman spectroscopy (EC-SERS) aptasensor for direct detection of DNA hybridization. Phys Chem Chem Phys 2016; 17:21356-63. [PMID: 25780805 DOI: 10.1039/c4cp05077k] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Rapid detection of disease biomarkers at the patient point-of-care is essential to timely and effective treatment. The research described herein focuses on the development of an electrochemical surface-enhanced Raman spectroscopy (EC-SERS) DNA aptasensor capable of direct detection of tuberculosis (TB) DNA. Specifically, a plausible DNA biomarker present in TB patient urine was chosen as the model target for detection. Cost-effective screen printed electrodes (SPEs) modified with silver nanoparticles (AgNP) were used as the aptasensor platform, onto which the aptamer specific for the target DNA was immobilized. Direct detection of the target DNA was demonstrated through the appearance of SERS peaks characteristic for adenine, present only in the target strand. Modulation of the applied potential allowed for a sizeable increase in the observed SERS response and the use of thiol back-filling prevented non-specific adsorption of non-target DNA. To our knowledge, this work represents the first EC-SERS study of an aptasensor for the direct, label-free detection of DNA hybridization. Such a technology paves the way for rapid detection of disease biomarkers at the patient point-of-care.
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Research Support, Non-U.S. Gov't |
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41 |
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Foote CJ, Clarke WC, Blackburn J. Inhibition of smolting in precocious male chinook salmon, Oncorhynchus tshawytscha. CAN J ZOOL 1991. [DOI: 10.1139/z91-255] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The ontogeny of precocious maturation in chinook salmon from Nicola River, British Columbia, was examined in conjunction with the effects of such maturation on smoltification and growth. A high proportion (56%) of male parr matured as yearlings. The growth patterns of precocious males and nonmaturing individuals of both sexes differed significantly. Precocious males appeared to grow rapidly relative to nonmaturing individuals in the early spring, but thereafter displayed a decreasing specific growth rate. In addition, precocious individuals gained more weight per increment of body length than nonmaturing individuals. The seawater adaptability of precocious individuals was lower than that of nonmaturing individuals at the three monthly sampling periods and decreased steadily as maturation proceeded.
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Dishner W, Cordasco EM, Blackburn J, Demeter S, Levin H, Carey WD. Pulmonary lymphangiomyomatosis. Chest 1984; 85:796-9. [PMID: 6723393 DOI: 10.1378/chest.85.6.796] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Lymphangiomyomatosis is an interesting disease with distinctive clinical and histopathologic findings. We report herein two additional cases of lymphangiomyomatosis, including one with clinical improvement after therapy with progesterone. This case is of particular significance in view of the patient's negative sex steroid receptor analysis. These findings open new avenues for future considerations in the therapy of this unusual but interesting disease.
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Case Reports |
41 |
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Foote CJ, Mayer I, Wood CC, Clarke WC, Blackburn J. On the developmental pathway to nonanadromy in sockeye salmon, Oncorhynchus nerka. CAN J ZOOL 1994. [DOI: 10.1139/z94-056] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The evolution of nonanadromous forms of salmonids has been linked to adaptive similarities between migration to the sea and migration to lakes, and to inhibition of smoltification by rapid development rates and early maturation. We examined the seasonal cycle of seawater adaptability in a landlocked (10 000 years) population of kokanee, Oncorhynchus nerka, to determine if the typical anadromous cycle persists in the absence of recent gene flow from sockeye salmon, as would be expected if components of smoltification are beneficial to a lacustrine existence. We also monitored the effects of maturation on seawater adaptability, to determine if they had an inhibitory effect on smoltification, as would be expected if a developmental conflict was responsible for the evolution of nonanadromous forms. Maturation was measured through the growth of gonadal tissue and the increase in circulating testosterone and 11-ketotestosterone. Landlocked kokanee showed the seawater adaptability cycle typical of sockeye salmon, and maturation had no inhibitory effect on seawater adaptability until near, or at, full maturity. We conclude that at least some components of smoltification must be beneficial to a life in lakes to account for the continued maintenance of the cycle. Further, rapid development and maturation on their own do not appear to account for the evolution of nonanadromous populations of O. nerka.
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Tarttelin EE, Gregory-Evans CY, Bird AC, Weleber RG, Klein ML, Blackburn J, Gregory-Evans K. Molecular genetic heterogeneity in autosomal dominant drusen. J Med Genet 2001; 38:381-4. [PMID: 11389162 PMCID: PMC1734899 DOI: 10.1136/jmg.38.6.381] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
OBJECTIVE Autosomal dominant drusen is of particular interest because of its phenotypic similarity to age related macular degeneration. Currently, mutation R345W of EFEMP1 and, in a single pedigree, linkage to chromosome 6q14 have been causally related to the disease. We proposed to investigate and quantify the roles of EFEMP1 and the 6q14 locus in dominant drusen patients from the UK and USA. DESIGN Molecular genetic analysis. PARTICIPANTS Ten unrelated families and 17 young drusen patients. MAIN OUTCOME MEASURES Exons 1 and 2 of EFEMP1 were characterised by 5' rapid amplification of cDNA ends and direct sequencing. Exons 1-12 of EFEMP1 were then investigated for mutation by direct sequencing. A HpaII restriction digest test was constructed to detect the EFEMP1 R345W mutation. Marker loci spanning the two dominant drusen linked loci were used to generate haplotype data. RESULTS Only seven of the 10 families (70%) and one of the 17 sporadic patients (6%) had the R345W mutation. The HpaII restriction digest test was found to be a reliable and quick method for detecting this. No other exonic or splice site mutation was identified. Of the three families without EFEMP1 mutation, two were linked to the 2p16 region. CONCLUSIONS EFEMP1 R345W accounts for only a proportion of the dominant drusen phenotype. Importantly, other families linked to chromosome 2p16 raise the possibility of EFEMP1 promoter sequence mutation or a second dominant drusen gene at this locus. Preliminary haplotype data suggest that the disease gene at the 6q14 locus is responsible for only a minority of dominant drusen cases.
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research-article |
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10
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Chang B, Allen C, Blackburn J, Hilton P. Thermal and Fluid Flow Characteristics and their Relationships with Porosity in Laser Welding of AA5083. ACTA ACUST UNITED AC 2013. [DOI: 10.1016/j.phpro.2013.03.104] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Blackburn J, Kawasaki K, Porntaveetus T, Kawasaki M, Otsuka-Tanaka Y, Miake Y, Ota MS, Watanabe M, Hishinuma M, Nomoto T, Oommen S, Ghafoor S, Harada F, Nozawa-Inoue K, Maeda T, Peterková R, Lesot H, Inoue J, Akiyama T, Schmidt-Ullrich R, Liu B, Hu Y, Page A, Ramírez Á, Sharpe PT, Ohazama A. Excess NF-κB induces ectopic odontogenesis in embryonic incisor epithelium. J Dent Res 2014; 94:121-8. [PMID: 25376721 DOI: 10.1177/0022034514556707] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Nuclear factor kappa B (NF-κB) signaling plays critical roles in many physiological and pathological processes, including regulating organogenesis. Down-regulation of NF-κB signaling during development results in hypohidrotic ectodermal dysplasia. The roles of NF-κB signaling in tooth development, however, are not fully understood. We examined mice overexpressing IKKβ, an essential component of the NF-κB pathway, under keratin 5 promoter (K5-Ikkβ). K5-Ikkβ mice showed supernumerary incisors whose formation was accompanied by up-regulation of canonical Wnt signaling. Apoptosis that is normally observed in wild-type incisor epithelium was reduced in K5-Ikkβ mice. The supernumerary incisors in K5-Ikkβ mice were found to phenocopy extra incisors in mice with mutations of Wnt inhibitor, Wise. Excess NF-κB activity thus induces an ectopic odontogenesis program that is usually suppressed under physiological conditions.
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Research Support, Non-U.S. Gov't |
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Blackburn J, Locher JL, Morrisey MA, Becker DJ, Kilgore ML. The effects of state-level expenditures for home- and community-based services on the risk of becoming a long-stay nursing home resident after hip fracture. Osteoporos Int 2016; 27:953-961. [PMID: 26400010 DOI: 10.1007/s00198-015-3327-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 09/15/2015] [Indexed: 10/23/2022]
Abstract
SUMMARY This study measures the effect of spending policies for long-term care services on the risk of becoming a long-stay nursing home resident after a hip fracture. Relative spending on community-based services may reduce the risk of long-term nursing home residence. Policies favoring alternative sources of care may provide opportunities for older adults to remain community-bound. INTRODUCTION This study aims to understand how long-term care policies affect outcomes by investigating the effect of state-level spending for home- and community-based services (HCBSs) on the likelihood of an individual's nursing home placement following hip fracture. METHODS This study uses data from the 5% sample of Medicare beneficiaries from 2005 to 2010 to identify incident hip fractures among dual-eligibility, community-dwelling adults aged at least 65 years. A multilevel generalized estimating equation (GEE) model estimated the association between an individual's risk of nursing home residence within 1 year and the percent of states' Medicaid long-term support service (LTSS) budget allocated to HCBS. Other covariates included expenditures for Title III services and individual demographic and health status characteristics. RESULTS States vary considerably in HCBS spending, ranging from 17.7 to 83.8% of the Medicaid LTSS budget in 2009. Hip fractures were observed from claims among 7778 beneficiaries; 34% were admitted to a nursing home and 25% died within 1 year. HCBS spending was associated with a decreased risk of nursing home residence by 0.17 percentage points (p 0.056). CONCLUSIONS Consistent with other studies, our findings suggest that state policies favoring an emphasis on HCBS may reduce nursing home residence among low-income older adults with hip fracture who are at high risk for institutionalization.
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Blackburn J, Wylde V, Greenwood R, Blom AW, Levy A. The effect of numbness on outcome from total knee replacement. Ann R Coll Surg Engl 2017; 99:385-389. [PMID: 28462655 DOI: 10.1308/rcsann.2017.0026] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
INTRODUCTION Some patients report continuing pain and functional limitations after total knee replacement (TKR). While numbness around the TKR scar is common, the impact of numbness is less clear. One particular activity that could be influenced by numbness is kneeling. The aim of this study was to explore the impact of numbness around TKR scars on health related quality of life and kneeling ability. METHODS Fifty-six patients were recruited one year after primary TKR. Sensation around the knee was assessed through patient self-reporting, monofilament testing and vibration, and patients' distress was measured on a visual analogue scale. Patient reported outcome measures (PROMs) including the Western Ontario and McMaster Universities (WOMAC®) index, the Knee injury and Osteoarthritis Outcome Score (KOOS), the painDETECT® (Pfizer, Berlin, Germany) questionnaire and the EQ-5D™ (EuroQol, Rotterdam, Netherlands) questionnaire were used. Participants were also asked about kneeling ability. RESULTS While 68% of patients reported numbness around their TKR scar, there was no statistically significant correlation between numbness and distress at numbness (self-report: 0.23, p=0.08; monofilament: 0.15, p=0.27). Furthermore, numbness did not correlate significantly with joint specific PROMs (WOMAC®: 0.21, p=0.13; KOOS: 0.18, p=0.19). However, difficulty with kneeling did correlate with both self-reported numbness (0.36, p=0.020) and worse PROM scores (WOMAC® pain subscale: 0.62, p<0.001; KOOS: 0.64, p<0.001). CONCLUSIONS Numbness after knee replacement is common but is not associated with worse patient reported outcomes.
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Journal Article |
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14
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Bolut M, Kong C, Blackburn J, Cashell K, Hobson P. Yb-fibre Laser Welding of 6 mm Duplex Stainless Steel 2205. ACTA ACUST UNITED AC 2016. [DOI: 10.1016/j.phpro.2016.08.043] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Abstract
The effect of 1 g/kg D-glucose on amphetamine-induced increases in activity; stereotypy; and rotation in rats with unilateral 6-OHDA lesions of nigro-striatal neurons was examined. The amphetamine dose-response curve for stereotypy was shifted to the right by glucose but retained the same slope as the control curve, suggesting that glucose competes for amphetamine or dopamine receptors that mediate this behavior. The slope of the dose-response curve for activity was significantly decreased by glucose, suggesting that glucose reduces activity levels in a manner that is non-competitive with the action of amphetamine or dopamine. Amphetamine-induced turning was unaffected by glucose at all doses tested. These data suggest that the effect of amphetamine on each of the three motor behaviors may be mediated by different dopamine-containing neurons, or by different post-synaptic dopamine receptors. The findings are also consistent with other data suggesting that glucose antagonizes dopamine function, but they suggest that this antagonism may not be uniform over all dopaminergic neurons or receptor types.
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Shwartz M, Martin SG, Cooper DD, Ljung GM, Whalen BJ, Blackburn J. The effect of a thirty per cent reduction in physician fees on Medicaid surgery rates in Massachusetts. Am J Public Health 1981; 71:370-5. [PMID: 7008635 PMCID: PMC1619671 DOI: 10.2105/ajph.71.4.370] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
In this paper, we use an interrupted time series analysis to assess the effect of a 30 per cent reduction in the Medicaid reimbursement fee for physician services on the rate at which eight elective surgical procedures were performed in the Massachusetts Medicaid population. Tonsillectomy/adenoidectomy is the only procedure in which there was a statistically significant decline in the rate of surgery in most areas of the state following the fee cut. There is some evidence of an increase in the rate of disc surgeries/spinal fusions. The rate of other procedures increased in some areas of the state and decreased in other areas in the period after the fee cut.
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research-article |
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Blackburn J, Molyneux G, Pitard A, Rice CR, Page MI, Afshinjavid S, Javid FA, Coles SJ, Horton PN, Hemming K. Synthesis, conformation and antiproliferative activity of isothiazoloisoxazole 1,1-dioxides. Org Biomol Chem 2016; 14:2134-44. [DOI: 10.1039/c5ob02586a] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Isothiazoles (I) reacted with 1,3-dipoles or NaN3 to give cycloadducts (II) or thiazete (III). Thiazete (III) rearranged to give 1,2,3-oxathiazoline (IV).
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Chaimowitz GA, Glancy GD, Blackburn J. The duty to warn and protect--impact on practice. CANADIAN JOURNAL OF PSYCHIATRY. REVUE CANADIENNE DE PSYCHIATRIE 2000; 45:899-904. [PMID: 11190358 DOI: 10.1177/070674370004501004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVE To discuss the concepts of the duty to protect and the associated threat to confidentiality and their impact on practice for Canadian psychiatrists. METHOD We review these concepts and provide a synthesis of legal cases impacting psychiatric practice. CONCLUSION The onus is on the psychiatrist to make him or herself aware of the current state of the legal obligation with respect to duty to protect. The evolving concept of duty to protect has and will continue to have significant impact on the practice of psychiatry.
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Review |
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Cows I, Bolland J, Nunn A, Kerins G, Stein J, Blackburn J, Hart A, Henry C, Britton JR, Coop G, Peeler E. Defining environmental risk assessment criteria for genetically modified fishes to be placed on the EU market. ACTA ACUST UNITED AC 2010. [DOI: 10.2903/sp.efsa.2010.en-69] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Forbes RD, Lowry RP, Gomersall M, Blackburn J. Comparative immunohistologic studies in an adoptive transfer model of acute rat cardiac allograft rejection. Transplantation 1985; 40:77-85. [PMID: 3892797 DOI: 10.1097/00007890-198507000-00016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
It has been shown that fulminant acute rejection of rat cardiac allografts across a full haplotype disparity may occur as a direct result of adoptive transfer of sensitized W3/25+ MRC OX8- SIg- T helper/DTH syngeneic spleen cells to sublethally irradiated recipients. In order to establish the immunohistologic parameters of this form of rejection, allografts and recipient lymphoid tissue were analyzed using a panel of monoclonal antibodies of known cellular distribution. These data were compared with those obtained following reconstitution of irradiated allograft recipients with unseparated sensitized spleen cells, with unreconstituted irradiated donor recipient pairs, with unmodified first-set rejection, and with induced myocardial infarction of syngeneic heart grafts transplanted to normal and to sublethally irradiated recipients. Rejecting cardiac allografts transplanted to all reconstituted irradiated recipients were characterized by extensive infiltration with MRC OX8+ (T cytotoxic-suppressor, natural killer) cells even when this subset was virtually excluded from the reconstituting inocula. A similar proportional accumulation of MRC OX8+ cells observed at the infarct margins of syngeneic heart grafts transplanted to irradiated unreconstituted recipients greatly exceeded that present in normal nonirradiated controls. These data provide evidence that under conditions of heavy recipient irradiation, MRC OX8+ cells may be sequestered within heart grafts in response to nonspecific injury unrelated to the rejection process. Although there was no significant degree of MRC OX8+ cellular repopulation within organized secondary lymphoid tissues of irradiated animals over the study period, the density of ileal mucosal MRC OX8+ lymphocytes approximated normal at 7 days post-irradiation, raising the possibility that these cells could share a common origin with those sequestered within the heart grafts. Carbon+ MRC OX6+ macrophages were a significant component of the infiltrate in all rejecting cardiac allografts, as well as in all infarcted syngeneic heart grafts--providing further evidence that macrophage "activation" with expression of class II determinants may occur in response to nonspecific injury. In unmodified first-set rejection there was an intense B cell reaction in recipient spleens and lymph nodes. In the adoptive transfer model, marked B cell expansion was exclusively confined to the parathymic lymph nodes of irradiated allograft recipients reconstituted with the sensitized W3/25+, MRC OX8-, SIg- T helper/DTH donor cell inocula.(ABSTRACT TRUNCATED AT 400 WORDS)
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Comparative Study |
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Papalia-Finlay D, Blackburn J, Davis E, Dellmann M, Roberts P. Training cognitive functioning in the elderly--inability to replicate previous findings. Int J Aging Hum Dev 1981; 12:111-7. [PMID: 7203673 DOI: 10.2190/l11t-tm1t-86wy-n1by] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
This study was designed to replicate Hornblum and Overton's study which trained conservation ability in elderly women [1]. Thirty-four elderly women volunteers were given a pretest battery of area and volume conservation tasks; participants also completed an extensive life history questionnaire. Conservation scores were the highest yet recorded by elderly participants. Thirty-two women received perfect conservation scores; only two were "partial conservers"; no participant was a "nonconserver." Consequently, training was not implemented. These women had high levels of education, good health, adequate income, satisfying leisure activities, and positive attitudes about aging. Advanced chronological age does not guarantee poor conservation performance. The mechanism(s) whereby life history variables influence cognitive functioning needs to be determined.
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Roberts P, Papalia-Finlay D, Davis ES, Blackburn J, Dellmann M. "No two fields ever grow grass the same way": assessment of conservation abilities in the elderly. Int J Aging Hum Dev 1983; 15:185-95. [PMID: 7183564 DOI: 10.2190/l2cf-ppte-wgqq-78qw] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Within the past ten years, standard cognitive assessment procedures, including Piagetian tasks, have often been used with the elderly. The present paper examines several possible difficulties in interpreting the results of studied which employ Piagetian tasks, especially conservation tasks, with older individuals. First, it is noted that Piaget's clinical method allows more flexibility in the assessment of competence than do the more quantifiable, American techniques. However, most of the research studies suggesting a cognitive decline with age have utilized rigid assessment procedures. Second, the paper examines the possibility of task misinterpretation by the elderly. Examples from recent research, in which older persons stressed reality-based problem solving strategies rather than the more abstract strategies traditionally associated with Piagetian tasks, are provided. The possibility of cognitive change instead of cognitive decline with age is discussed, and the importance of utilizing procedures which can measure this change is stressed.
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Vanderwall J, Blackburn J. Suppression of some artifacts of modal noise in fiber-optic systems. OPTICS LETTERS 1979; 4:295-296. [PMID: 19687881 DOI: 10.1364/ol.4.000295] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Modal noise, which can cause severe distortion in signals transmitted by fiber optics, is an interference effect that is made more severe by the narrow spectral width of single-mode lasers. The linearity of these devices may be totally obscured after the optical signal has passed through the connectors and fiber lengths of a practical signal system. Dithering the laser's operating point by means of a high-frequency current (>2 GHz) has been found greatly to reduce modal noise.
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