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Bayer LE, Brown A, Mactutus CF, Booze RM, Strupp BJ. Prenatal cocaine exposure increases sensitivity to the attentional effects of the dopamine D1 agonist SKF81297. J Neurosci 2000; 20:8902-8. [PMID: 11102500 PMCID: PMC6773060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023] Open
Abstract
Sensitivity to the attentional effects of SKF81297, a selective full agonist at dopamine D(1) receptors, was assessed in adult rats exposed to cocaine prenatally (via intravenous injections) and controls. The task assessed the ability of the subjects to monitor an unpredictable light cue of either 300 or 700 msec duration and to maintain performance when presented with olfactory distractors. SKF81297 decreased nose pokes before cue presentation and increased latencies and response biases (the tendency to respond to the same port used on the previous trial), suggesting an effect of SKF81297 on the dopamine (DA) systems responsible for response initiation and selection. The cocaine-exposed (COC) and control animals did not differ in sensitivity to the effects of SKF81297 on these measures. In contrast, the COC animals were significantly more sensitive than were controls to the impairing effect of SKF81297 on omission errors, a measure of sustained attention. This pattern of results provides evidence that prenatal cocaine exposure produces lasting changes in the DA system(s) subserving sustained attention but does not alter the DA system(s) underlying response selection and initiation. These findings also provide support for the role of D(1) receptor activation in attentional functioning.
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602
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Aboody KS, Brown A, Rainov NG, Bower KA, Liu S, Yang W, Small JE, Herrlinger U, Ourednik V, Black PM, Breakefield XO, Snyder EY. Neural stem cells display extensive tropism for pathology in adult brain: evidence from intracranial gliomas. Proc Natl Acad Sci U S A 2000; 97:12846-51. [PMID: 11070094 PMCID: PMC18852 DOI: 10.1073/pnas.97.23.12846] [Citation(s) in RCA: 865] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
One of the impediments to the treatment of brain tumors (e.g., gliomas) has been the degree to which they expand, infiltrate surrounding tissue, and migrate widely into normal brain, usually rendering them "elusive" to effective resection, irradiation, chemotherapy, or gene therapy. We demonstrate that neural stem cells (NSCs), when implanted into experimental intracranial gliomas in vivo in adult rodents, distribute themselves quickly and extensively throughout the tumor bed and migrate uniquely in juxtaposition to widely expanding and aggressively advancing tumor cells, while continuing to stably express a foreign gene. The NSCs "surround" the invading tumor border while "chasing down" infiltrating tumor cells. When implanted intracranially at distant sites from the tumor (e.g., into normal tissue, into the contralateral hemisphere, or into the cerebral ventricles), the donor cells migrate through normal tissue targeting the tumor cells (including human glioblastomas). When implanted outside the CNS intravascularly, NSCs will target an intracranial tumor. NSCs can deliver a therapeutically relevant molecule-cytosine deaminase-such that quantifiable reduction in tumor burden results. These data suggest the adjunctive use of inherently migratory NSCs as a delivery vehicle for targeting therapeutic genes and vectors to refractory, migratory, invasive brain tumors. More broadly, they suggest that NSC migration can be extensive, even in the adult brain and along nonstereotypical routes, if pathology (as modeled here by tumor) is present.
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603
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Abstract
Efforts to observe the slow axonal transport of cytoskeletal polymers during the past decade have yielded conflicting results, and this has generated considerable controversy. The movement of neurofilaments has now been seen, and it is rapid, infrequent and highly asynchronous. This motile behaviour could explain why slow axonal transport has eluded observation for so long.
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604
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Nemec J, Garratt KN, Schaff HV, Goodwin M, Morrow D, Brown A, Khandheria BK. Asymptomatic occlusion of the left main coronary artery by an aortic pseudoaneurysm. Mayo Clin Proc 2000; 75:1205-8. [PMID: 11075753 DOI: 10.4065/75.11.1205] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Extrinsic compression of the left main coronary artery is a rare cause of coronary ischemia. We describe a 35-year-old Asian woman with complete asymptomatic occlusion of the left main coronary artery by a large aortic pseudoaneurysm. She underwent repair of the pseudoaneurysm and coronary artery bypass grafting at the Mayo Clinic in Rochester, Minn. The differential diagnosis is discussed. Based on this patient's age and associated vascular lesions, we conclude that Takayasu arteritis was the most likely cause of her condition.
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605
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LaForce CF, Pearlman DS, Ruff ME, Silvers WS, Weinstein SW, Clements DS, Brown A, Duke S, Harding SM, House KW. Efficacy and safety of dry powder fluticasone propionate in children with persistent asthma. Ann Allergy Asthma Immunol 2000; 85:407-15. [PMID: 11101186 DOI: 10.1016/s1081-1206(10)62556-2] [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: 12/01/2022]
Abstract
BACKGROUND Flovent Diskus is a powder formulation of the inhaled corticosteroid fluticasone propionate (FP) delivered via a breath-actuated, multidose inhaler. OBJECTIVE To determine the efficacy and safety of dry powder FP administered once or twice daily (200 microg per day) to children with persistent asthma. METHODS Twelve-week, randomized, double-blind, placebo-controlled, multicenter trial with a 52-week, open-label extension. Children aged 4 to 11 were required to have pulmonary function 50% to 85% of predicted values. The population was stratified for baseline therapy (inhaled corticosteroid/cromolyn or bronchodilators only). After a 2-week placebo run-in, 242 patients received dry powder FP 200 microg each morning, dry powder FP 100 microg BID, or placebo for 12 weeks; 192 were rerandomized to the QD or BID regimen for an additional 52 weeks of open-label treatment. Primary endpoints were mean changes in FEV1 and morning PEF recorded at clinic visits. RESULTS Both dry powder FP regimens significantly improved FEV1, evening PEF, and asthma symptoms at the double-blind phase endpoint (P < or = .017 compared with placebo). The BID regimen also significantly improved morning PEF and nighttime awakenings due to asthma (P < or = .005). Among patients previously treated with inhaled corticosteroids/cromolyn, improvements observed with the QD and BID regimens were similar. Patients switched from BID to open-label QD treatment showed additional improvements at week 52 generally comparable to patients who received the BID regimen during both phases. Fluticasone propionate was well tolerated for up to 64 weeks with few reports of drug-related adverse events or morning plasma cortisol abnormalities. CONCLUSIONS Once daily dosing of dry powder FP 200 microg is an effective and convenient alternative for children whose asthma is controlled with a more frequent dosing regimen of inhaled corticosteroids.
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606
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Brown A, Tipping RH, Maté B. Theoretical Study of the Collision-Induced Double Transition CO(2) (nu(3) = 1) + N(2) (nu(1) = 1) <-- CO(2) (nu(3) = 0) + N(2) (nu(1) = 0) at 296 K. JOURNAL OF MOLECULAR SPECTROSCOPY 2000; 204:153-158. [PMID: 11034854 DOI: 10.1006/jmsp.2000.8214] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A procedure is presented for the calculation of the double vibrational collision-induced absorption CO(2) (nu(3) = 1) + N(2) (nu(1) = 1) <-- CO(2) (nu(3) = 0) + N(2) (nu(1) = 0) on the basis of quantum lineshapes computed using an isotropic potential and dipole-induced dipole functions. The linestrengths and energies of the vibration-rotation transitions are treated explicitly for N(2), utilizing the HITRAN database for CO(2). The theoretical absorption profile is compared to recent experimental results. By narrowing the width of the individual lines contributing to the overall absorption profile relative to their values determined for N(2)-N(2) collision-induced absorption, excellent agreement between theory and experiment is obtained. Copyright 2000 Academic Press.
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607
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Pai P, Thomas S, Hoenich N, Roberts R, House I, Brown A. Treatment of a case of severe mercuric salt overdose with DMPS (dimercapo-1-propane sulphonate) and continuous haemofiltration. Nephrol Dial Transplant 2000; 15:1889-90. [PMID: 11071989 DOI: 10.1093/ndt/15.11.1889] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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608
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Brown A, Hill C, Khan K. Drains in reduction mammaplasty. Ann Plast Surg 2000; 45:466-7. [PMID: 11037177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
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609
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Din-Dzietham R, Liao D, Diez-Roux A, Nieto FJ, Paton C, Howard G, Brown A, Carnethon M, Tyroler HA. Association of educational achievement with pulsatile arterial diameter change of the common carotid artery: the Atherosclerosis Risk in Communities (ARIC) Study, 1987-1992. Am J Epidemiol 2000; 152:617-27. [PMID: 11032156 DOI: 10.1093/aje/152.7.617] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Education is strongly inversely associated with common carotid artery intima-media thickness in the Atherosclerosis Risk in Communities (ARIC) Study. The authors extended the ARIC study of preclinical atherosclerosis by evaluating the cross-sectional association of education with common carotid artery elasticity. This study included 10,091 Black and White men and women aged 45-64 years who were free of clinical coronary heart disease and stroke/transient ischemic attack. Arterial elasticity was assessed by pulsatile arterial diameter change (PADC), derived from phase-locked echo-tracking. The smaller the PADC, the stiffer the artery. Education was categorized into grade school, high school without graduation, high school with graduation, vocational school, some college, and graduate/professional school. PADC was directly associated with educational attainment. The mean PADCs, adjusted for age, height, diastolic diameter, systolic blood pressure, pulse pressure (linear and squared), ethnicity, gender, and smoking status, in successively higher education strata were 402 (standard error (SE) 5), 403 (SE 4), 407 (SE 3), 413 (SE 4), 416 (SE 2), and 417 (SE 4) microm (p = 0.007). To the authors' knowledge, this is the first time such an association has been reported. If arterial dilation impairment precedes arterial wall thickening in the atherosclerotic process, as recent studies on endothelial dysfunction suggest, these results indicate that low socioeconomic status may be associated with early arterial pathophysiologic changes-an effect that appears to be mediated by established cardiovascular disease risk factors.
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610
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Hunter GR, Wetzstein CJ, Fields DA, Brown A, Bamman MM. Resistance training increases total energy expenditure and free-living physical activity in older adults. J Appl Physiol (1985) 2000; 89:977-84. [PMID: 10956341 DOI: 10.1152/jappl.2000.89.3.977] [Citation(s) in RCA: 179] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The purpose of this study was to determine what effects 26 wk of resistance training have on resting energy expenditure (REE), total free-living energy expenditure (TEE), activity-related energy expenditure (AEE), engagement in free-living physical activity as measured by the activity-related time equivalent (ARTE) index, and respiratory exchange ratio (RER) in 61- to 77-yr-old men (n = 8) and women (n = 7). Before and after training, body composition (four-compartment model), strength, REE, TEE (doubly labeled water), AEE (TEE - REE + thermic response to meals), and ARTE (AEE adjusted for energy cost of standard activities) were evaluated. Strength (36%) and fat-free mass (2 kg) significantly increased, but body weight did not change. REE increased 6.8%, whereas resting RER decreased from 0.86 to 0.83. TEE (12%) and ARTE (38%) increased significantly, and AEE (30%) approached significance (P = 0.06). The TEE increase remained significant even after adjustment for the energy expenditure of the resistance training. In response to resistance training, TEE increased and RER decreased. The increase in TEE occurred as a result of increases in both REE and physical activity. These results suggest that resistance training may have value in increasing energy expenditure and lipid oxidation rates in older adults, thereby improving their metabolic profiles.
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611
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Noula C, Bonzom P, Brown A, Gibbons WA, Martin J, Nicolaou A. 1H-NMR lipid profiles of human blood platelets; links with coronary artery disease. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1487:15-23. [PMID: 11004608 DOI: 10.1016/s1388-1981(00)00078-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Blood platelets are closely involved in the early development of atherosclerosis and in the events that lead to thrombosis, both of which are dominating factors in coronary artery disease (CAD). The aim of the present study was to evaluate the platelet lipid profiles of patients suffering from CAD and explore the possibility of a link between platelet lipids and CAD, using high-resolution high-field proton nuclear magnetic resonance spectroscopy as the analytical tool. The total platelet lipid profiles of healthy volunteers were compared with those of patients presenting with chest pain requiring coronary angiography. Two lipid groups changed significantly: cholesterol increased by 16.5% and total diacylglycerophospholipids decreased by 15.7%. There was also a significant decrease of the ethanolamine-containing phospholipids, by 4.7%; the extent of unsaturation of the fatty acid chains, by 0.2, and increase of the linoleate content of the fatty acid chains, by 1.9%. Our results suggest that platelet lipid abnormalities occur in patients with CAD and these changes may predate the development of overt atherosclerosis.
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612
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Raeside DA, Smith A, Brown A, Patel KR, Madhok R, Cleland J, Peacock AJ. Pulmonary artery pressure measurement during exercise testing in patients with suspected pulmonary hypertension. Eur Respir J 2000; 16:282-7. [PMID: 10968504 DOI: 10.1034/j.1399-3003.2000.16b16.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
It is recognized that exercise produces abnormally large increases in pulmonary artery pressure in patients with pulmonary vascular disease as a consequence of a variety of disorders, but the relationship between pressure and cardiopulmonary exercise performance is poorly understood. This lack of understanding is due (in part) to difficulty making measurements of pulmonary haemodynamics using conventional fluid filled catheters. This article seeks to improve understanding by comparing variables measured during formal exercise testing with simultaneous measurements of pulmonary artery pressure using a micro-manometer tipped catheter. Ten patients with suspected pulmonary hypertension were studied using a micromanometer tipped pulmonary artery catheter, during cardiopulmonary exercise testing. Ventilatory equivalents for oxygen and carbon dioxide correlated with the pulmonary artery pressure measured on exercise, but oxygen pulse and oxygen uptake did not. Ventilatory equivalents, noninvasively measured during exercise, may merit further study as potential surrogates of pulmonary artery pressure and hence be useful in identifying individuals at risk of developing pulmonary hypertension.
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613
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Massarella JW, He GZ, Dorr A, Nieforth K, Ward P, Brown A. The pharmacokinetics and tolerability of the oral neuraminidase inhibitor oseltamivir (Ro 64-0796/GS4104) in healthy adult and elderly volunteers. J Clin Pharmacol 2000; 40:836-43. [PMID: 10934667 DOI: 10.1177/00912700022009567] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The tolerability and pharmacokinetics of Ro 64-0802, a potent, selective inhibitor of influenza neuraminidase, and its oral prodrug oseltamivir were investigated in three double-blind, placebo-controlled studies. Two studies involved healthy adult volunteers (18-55 years) (n = 48) who received single (20-1000 mg) or bid doses (50-500 mg) (n = 32) of oseltamivir or placebo for 7 days. Healthy elderly volunteers (> or = 65 years) (n = 24) received oseltamivir 100 to 200 mg bid or placebo for 7 days in a third study. Measurable plasma concentrations of the active metabolite appeared rapidly in plasma and were significantly higher and longer lasting than those of oseltamivir. Pharmacokinetics of both compounds were linear. Multiple-dose exposure was predictable from single-dose data, and steady-state plasma concentrations were achieved within 3 days of bid drug administration. Oseltamivir was well tolerated at single doses of up to 1000 mg and twice-daily doses of up to 500 mg. Adverse events were mild in intensity. Exposure to both prodrug and active metabolite was increased in elderly patients by approximately 25%. However, due to the wide safety margin of both compounds, no dose adjustment is necessary for elderly patients.
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614
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Venkataraman ST, Khan N, Brown A. Validation of predictors of extubation success and failure in mechanically ventilated infants and children. Crit Care Med 2000; 28:2991-6. [PMID: 10966284 DOI: 10.1097/00003246-200008000-00051] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To validate predictors of extubation success and failure in mechanically ventilated infants and children by using bedside measures of respiratory function. DESIGN Prospective, descriptive study. SETTING A university-affiliated children's hospital with a 51-bed critical care area. PATIENTS All infants and children who were mechanically ventilated for > or =24 hrs except neonates < or =37 wks gestation and patients with neuromuscular disease. INTERVENTIONS None. MEASUREMENTS AND METHODS Extubation failure was defined as reintubation within 48 hrs of extubation in the absence of upper airway obstruction. Failure rates were calculated for different ranges (selected a priori of preextubation measures of breathing effort, ventilator support, respiratory mechanics, central inspiratory drive, and integrated indices useful in adults. Effort of spontaneous breathing was assessed by the respiratory rate standardized to age, the presence of retractions and paradoxic breathing, inspiratory pressure, maximal negative inspiratory pressure, ratio of inspiratory pressure to maximal negative inspiratory pressure, and tidal volume indexed to body weight of a spontaneous breath. Ventilator support was measured by F(IO2), mean airway pressure, oxygenation index, and the fraction of total minute ventilation provided by the ventilator. Respiratory mechanics was assessed by peak ventilatory inspiratory pressure and dynamic compliance. Central inspiratory drive was assessed by mean inspiratory flow. Frequency to tidal volume ratio and the CROP (compliance, rate, oxygenation, and pressure) indexed to body weight, the integrated indices useful in predicting extubation failure in adults, were also calculated. A regression test for a linear trend in proportions was performed with preselected ranges and the corresponding failure rates. The failure rates from this study (validation group) were compared to those published previously (prediction group) by the chi-square test for proportions. The distribution of categorical variables between groups was analyzed by using the chi-square test or the Fisher's exact test, and p < .05 was considered significant. MAIN RESULTS The study involved 312 patients. There were no differences in any of the clinical characteristics between the prediction and validation groups. The reasons for reintubation were similar in both groups. Preextubation data were also similar between the two groups. There were no differences between the prediction and the validation groups in failure rates with different ranges. There were no differences in the failure rates for any of the cutoff values for peak ventilatory inspiratory pressure, mean airway pressure, F(IO2), oxygenation index, dynamic compliance, tidal volume indexed to body weight of a spontaneous breath, fraction of total minute ventilation provided by the ventilator, and mean inspiratory flow. CONCLUSIONS Bedside measures of respiratory function can predict extubation success and failure in infants and children. Both a low risk and a high risk of failure can be determined by using these measures. Integrated indices useful in adults do not reliably predict extubation success or failure in infants and children. Our study validates our previously published study.
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615
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Whitlock WL, Brown A, Moore K, Pavliscsak H, Dingbaum A, Lacefield D, Buker K, Xenakis S. Telemedicine improved diabetic management. Mil Med 2000; 165:579-84. [PMID: 10957848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
Effective control of diabetes is known to delay or prevent the end-organ complications of this disease. Can telemedicine improve a patient's ability to self-manage diabetes? Twenty-eight patients entered a study comparing home telemedicine consultation with standard outpatient care. A nurse case manager contacted the telemedicine group once a week under the direction of a primary care physician, who contacted the telemedicine group once a month. Laboratory studies and total body weight were measured at the beginning and at the end of the 3-month study. The hemoglobin A1c (HbA1c) and total body weight improved significantly in the intervention (telemedicine) group, as shown by a 16% reduction in mean HbA1c level (from 9.5 to 8.2%) and a 4% mean weight reduction (from 214.3 to 206.7 pounds). Based on our experience, we present a functionally based telemedicine classification system to improve the application of electronic medicine in future studies.
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616
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McParland VJ, Kad NM, Kalverda AP, Brown A, Kirwin-Jones P, Hunter MG, Sunde M, Radford SE. Partially unfolded states of beta(2)-microglobulin and amyloid formation in vitro. Biochemistry 2000; 39:8735-46. [PMID: 10913285 DOI: 10.1021/bi000276j] [Citation(s) in RCA: 282] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Dialysis-related amyloidosis (DRA) involves the aggregation of beta(2)-microglobulin (beta(2)m) into amyloid fibrils. Using Congo red and thioflavin-T binding, electron microscopy, and X-ray fiber diffraction, we have determined conditions under which recombinant monomeric beta(2)m spontaneously associates to form fibrils in vitro. Fibrillogenesis is critically dependent on the pH and the ionic strength of the solution, with low pH and high ionic strength favoring fibril formation. The morphology of the fibrils formed varies with the growth conditions. At pH 4 in 0.4 M NaCl the fibrils are approximately 10 nm wide, relatively short (50-200 nm), and curvilinear. By contrast, at pH 1.6 the fibrils formed have the same width and morphology as those formed at pH 4 but extend to more than 600 nm in length. The dependence of fibril growth on ionic strength has allowed the conformational properties of monomeric beta(2)m to be determined under conditions where fibril growth is impaired. Circular dichroism studies show that titration of one or more residues with a pK(a) of 4.7 destabilizes native beta(2)m and generates a partially unfolded species. On average, these molecules retain significant secondary structure and have residual, non-native tertiary structure. They also bind the hydrophobic dye 1-anilinonaphthalene-8-sulfonic acid (ANS), show line broadening in one-dimensional (1)H NMR spectra, and are weakly protected from hydrogen exchange. Further acidification destabilizes this species, generating a second, more highly denatured state that is less fibrillogenic. These data are consistent with a model for beta(2)m fibrillogenesis in vitro involving the association of partially unfolded molecules into ordered fibrillar assemblies.
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617
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Masungi Luko C, Vansanten G, Ryelandt M, Denis O, Wuilmart C, Andris F, Van Acker A, Brait M, Cloquet JP, Ismaili N, Nisol F, Latinne D, Brown A, Leo O, Bazin H, Urbain J. Distinct VH repertoires in primary and secondary B cell lymphocyte subsets in the preimmune repertoire of A/J mice: the CRI-A idiotype is preferentially associated with the HSA(low) B cell subset. Eur J Immunol 2000; 30:2312-22. [PMID: 10940922 DOI: 10.1002/1521-4141(2000)30:8<2312::aid-immu2312>3.0.co;2-p] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The anti-arsonate immune response of A/J mice is characterized by the occurrence of several recurrent idiotypes with a different temporal pattern of expression. The CRI-A idiotype is typically a memory idiotype since it appears late in the primary and dominates the secondary as well as subsequent immune responses. The CRI-C idiotype is present throughout the responses, including the primary one. Naive adult A/J mice treated repeatedly with anti-mu or anti-delta monoclonal antibodies exhibit a completely different balance of HSA(low) and HSA(high) B cell subsets and an opposite idiotype profile after immunization with p-azophenylarsonate coupled to hemocyanin. Anti-mu treatment leads to a striking enhancement of the HSA(low) cell subset associated with an earlier important synthesis of CRI-A(+) antibodies, while anti-delta treatment enhances significantly the HSA(high) compartment with a strong decrease of CRI-A and persistence of CRI-C1 antibodies. Semiquantitative PCR analysis reveals that the presence of CRI-A transcripts is associated with the HSA(low) compartment, while CRI-C transcripts are mainly associated with HSA(high) B cell subsets. This has been demonstrated with spleen cells of adult A/J mice treated with anti-mu or anti-delta antibodies and also with purified B cell subsets of unimmunized adult A/J mice and on neonatal spleen cells. It appears that the memory (CRI-A) idiotype is selected into the HSA(low) B cell subset before antigen arrival.
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618
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Prezant DJ, Freeman K, Kelly KJ, Malley KS, Karwa ML, McLaughlin MT, Hirschhorn R, Brown A. Impact of a design modification in modern firefighting uniforms on burn prevention outcomes in New York City firefighters. J Occup Environ Med 2000; 42:827-34. [PMID: 10953821 DOI: 10.1097/00043764-200008000-00013] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Our aim was to determine the impact of three different firefighting uniforms (traditional, modern, and modified modern) on the incidence and severity of thermal burn injuries, the major occupational injury affecting firefighters. Injury data were collected prospectively for the entire New York City Fire Department (FDNY) firefighting force wearing FDNY's traditional uniform (protective over-coat) from May 1, 1993 to August 31, 1993; FDNY's modern uniform (protective over-coat and over-pant) from May 1, 1995 to August 31, 1995; and FDNY's modified modern uniform (short sleeved shirt and short pants, rather than long-sleeved shirt and long pants, worn under firefighter's protective over-clothes) from May 1, 1998 to August 31, 1998. Outcome measures were burn incidence and severity. Adverse outcomes were heat exhaustion and cardiac events. During this 12-month study, 29,094 structural fires occurred. The incidence rate for upper extremity burns was 2341 per 100,000 fires and for lower extremity burns, 2076 per 100,000 fires. With the change from the traditional to modern uniform, the distribution of burns per fire decreased significantly (P = 0.001) for upper extremity burns (86%) and lower extremity burns (93%). With the change from traditional to modern uniform, days lost to medical leave for upper or lower extremity burns decreased by 89%. The majority of burns occurred at the lower arm and mid-leg, and the change to the modern uniform decreased such burns by 87% and 92%. Burn incidence and severity were not significantly affected by the change to the modified modern uniform. The distribution of heat exhaustion or cardiac events per fire was not significantly affected by the change from the traditional to modern uniform, and heat exhaustion was decreased (P < 0.001) by the change to the modified modern uniform. In conclusion, the modern uniform dramatically reduced burn incidence and severity without adverse impact. The modified modern uniform significantly reduced heat exhaustion without significantly affecting thermal protection.
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619
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Brown A, Yates PA, Burrola P, Ortuño D, Vaidya A, Jessell TM, Pfaff SL, O'Leary DD, Lemke G. Topographic mapping from the retina to the midbrain is controlled by relative but not absolute levels of EphA receptor signaling. Cell 2000; 102:77-88. [PMID: 10929715 DOI: 10.1016/s0092-8674(00)00012-x] [Citation(s) in RCA: 260] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Topographic maps are a fundamental feature of sensory representations in nervous systems. The formation of one such map, defined by the connection of ganglion cells in the retina to their targets in the superior colliculus of the midbrain, is thought to depend upon an interaction between complementary gradients of retinal EphA receptors and collicular ephrin-A ligands. We have tested this hypothesis by using gene targeting to elevate EphA receptor expression in a subset of mouse ganglion cells, thereby producing two intermingled ganglion cell populations that express distinct EphA receptor gradients. We find that these two populations form separate maps in the colliculus, which can be predicted as a function of the net EphA receptor level that a given ganglion cell expresses relative to its neighbors.
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620
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Bramley R, Brown A, Ellison S, Hardcastle W, Martin A. Qualitative analysis: a guide to best practice--forensic science extension. Sci Justice 2000; 40:163-70. [PMID: 11050848 DOI: 10.1016/s1355-0306(00)71971-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: 11/21/2022]
Abstract
Qualitative analysis is arguably the cornerstone of analysis since what cannot be recognised cannot be quantified. This is especially true in the case of the forensic sciences where, for example, the mere presence of a prohibited, or controlled, substance in an unauthorized setting is indicative of a potential offence. This paper presents a set of principles of good practice in qualitative analysis. The principles are placed in the context of forensic science and extend earlier published guidance.
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Brown A. Visualization of single neurofilaments by immunofluorescence microscopy of splayed axonal cytoskeletons. CELL MOTILITY AND THE CYTOSKELETON 2000; 38:133-45. [PMID: 9331218 DOI: 10.1002/(sici)1097-0169(1997)38:2<133::aid-cm3>3.0.co;2-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Treatment of cultured neurons with non-ionic detergents under certain conditions causes the axonal microtubules to splay apart from each other, allowing individual microtubules to be visualized by immunofluorescence microscopy [Brown et al., 1993, J. Cell Sci. 104: 339-352]. I have investigated whether axonal neurofilaments separate from each other under similar conditions. Cultures of dissociated dorsal root ganglion (DRG) neurons from fetal rats were treated with non-ionic detergent and fixed with formaldehyde. Neurofilaments were visualized by immunofluorescence microscopy using a polyclonal antiserum specific for NF-L. Treatment of the neurons with Triton X-100 or saponin caused filamentous structures to splay apart from each other along the entire length of the axon. Quantitative analysis of fluorescence intensity along the filamentous structures indicated that many of them represent single neurofilaments and that single and bundled neurofilaments can be distinguished based on their fluorescence intensity. The extent of this splaying phenomenon was dependent on time and detergent concentration. Temporal analysis indicated that short portions of single neurofilaments initially loop out from the axonal bundle and then subsequently splay apart further along their length and adhere to the polylysine/laminin coated substrate. The maximum observed length for a single axonal neurofilament was 183 microm in neurons after only 1 day in culture, which indicates that neurofilaments can attain remarkable lengths in these young cultured neurons. The splayed axonal cytoskeleton preparation described here allows individual axonal neurofilaments to be visualized by immunofluorescence microscopy, which is not possible in conventional preparations due to the dense packing of these polymers in axons.
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Abstract
The p53 tumour suppressor phosphoprotein associates with proteins involved in DNA replication, transcription, cell cycle machinery and regulation of its own expression. Recently it has been shown that p53 can also bind to trk A tyrosine kinase which is the receptor for nerve growth factor (NGF). This study demonstrates that p53 appears to associate with trk A via c-abl. Endogenous c-abl was detected when the trk A and p53 complex was immunoprecipitated from lysates of NGF stimulated NIH3T3 cells expressing trk A or NIH3T3 cells expressing trk A and a temperature sensitive p53 (val 135). Endogenous c-abl and trk A association was observed in NGF stimulated p53 negative fibroblasts transfected with trk A alone; suggesting that c-abl can independently bind to trk A in the absence of p53. Interestingly, association between endogenous p53 and trk A was not detected in NGF stimulated abl negative fibroblasts transfected with trk A or when these cells were exposed to gamma radiation. This result suggests that p53 preferentially binds to trk A in the presence of c-abl and that p53 and trk A do not appear to associate directly even if p53 is activated and its levels increased by gamma radiation. Overall, these data suggest that c-abl is possibly acting as an adaptor or bridge between p53 and trk A. Oncogene (2000).
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Wassef AA, Dott SG, Harris A, Brown A, O'Boyle M, Meyer WJ, Rose RM. Randomized, placebo-controlled pilot study of divalproex sodium in the treatment of acute exacerbations of chronic schizophrenia. J Clin Psychopharmacol 2000; 20:357-61. [PMID: 10831024 DOI: 10.1097/00004714-200006000-00011] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Experimental and clinical data suggest that GABA-ergic drugs such as valproate may have a potential role in the treatment of schizophrenia. The authors designed a 21-day prospective, double-blind, randomized, placebo-controlled pilot study of divalproex sodium as add-on treatment to haloperidol in 12 hospitalized patients with acute exacerbations of chronic schizophrenia. All patients received haloperidol 10 mg/day for 3 days and 15 mg/day for the remaining 18 days. In addition, five patients were randomly assigned to receive divalproex augmentation and seven to receive placebo. The divalproex dose was adjusted to a target serum concentration of 75 microg/mL for 2 weeks; placebo replaced divalproex during the third and last weeks to determine any carryover effect. Psychiatric rating scales were administered at baseline and on days 7, 14, and 21. Although the placebo group improved with haloperidol treatment, the divalproex group demonstrated greater improvement. On day 21, the divalproex group had greater improvement from baseline on the Clinical Global Impression Scale (p < or = 0.04), Brief Psychiatric Rating Scale (p < or = 0.13), and Schedule for Assessment of Negative Symptoms scores (p < or = 0.007). After divalproex withdrawal on day 15, a carryover effect was observed during week 3. The authors concluded that the addition of divalproex sodium to standard antipsychotic drugs may prove effective in relieving the symptoms of acute schizophrenia. Future studies may benefit from the design of this pilot study. However, it is premature to apply this augmentation strategy in the clinical setting just yet because of the small sample size and the likely heterogeneity of the disorder.
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Brown A. Classification of JNC VI blood pressure stages and risk groups in the ARIC study. Am J Hypertens 2000. [DOI: 10.1016/s0895-7061(00)01009-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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Malaspina D, Goetz RR, Yale S, Berman A, Friedman JH, Tremeau F, Printz D, Amador X, Johnson J, Brown A, Gorman JM. Relation of familial schizophrenia to negative symptoms but not to the deficit syndrome. Am J Psychiatry 2000; 157:994-1003. [PMID: 10831482 DOI: 10.1176/appi.ajp.157.6.994] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Although a family history of schizophrenia has been associated with negative symptoms, family history is inconsistently related to the presence of the deficit syndrome. METHOD The authors assessed family history and the deficit syndrome in 99 patients with DSM-III-R-diagnosed schizophrenia who were assessed during clinical treatment. Of these 99 patients, 45 were assessed both while antipsychotic free and during antipsychotic treatment to index their treatment response. RESULTS Patients with (N=39) and without (N=60) a family history of schizophrenia had similar proportions of the deficit syndrome. Yet family history and deficit syndrome categorizations identified a group with greater negative symptoms on the Positive and Negative Syndrome Scale. Those with a family history had greater emotional withdrawal, poor rapport, and lack of spontaneity. Groups with and without the deficit syndrome similarly differed in these symptoms but also in affective blunting, motor retardation, and passive or apathetic social withdrawal. The study involving antipsychotic-free and antipsychotic treatment phases showed main medication effects explaining positive, psychopathology, depression, and activation symptoms but not negative symptoms. Only patients without a family history had improved negative symptoms with antipsychotic treatment. CONCLUSIONS Patients with a family history of schizophrenia had greater and more treatment-resistant negative symptoms than those without a family history. They were not more likely to have the deficit syndrome. The group with a family history had more pathology only in negative symptoms related to psychosocial function. The stable negative symptoms specifically related to the genetic vulnerability to inherit schizophrenia might be those associated with psychosocial functioning.
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