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Korutla L, Wang PJ, Lewis DM, Neustadter JH, Stromberg MF, Mackler SA. Differences in expression, actions and cocaine regulation of two isoforms for the brain transcriptional regulator NAC1. Neuroscience 2002; 110:421-9. [PMID: 11906783 DOI: 10.1016/s0306-4522(01)00518-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
BTB/POZ proteins can influence the cell cycle and contribute to oncogenesis. Many family members are present in the mammalian CNS. Previous work demonstrated elevated NAC1 mRNA levels in the rat nucleus accumbens in response to cocaine. NAC1 acts like other BTB/POZ proteins that regulate transcription but is unusual because of the absence of identifiable DNA binding domains. cDNAs were isolated encoding two NAC1 isoforms differing by only 27 amino acids (the longer isoform contains 514 amino acids). The mRNAs for both isoforms were simultaneously expressed throughout the rat brain and peripheral tissues. Semi-quantitative reverse transcription-polymerase chain reaction analysis revealed that the mRNA of the longer isoform was more abundant than the mRNA of the shorter isoform. Western blot analysis demonstrated a similar unequal distribution between the isoforms in the CNS. The longer isoform was the more abundant of the two NAC1 proteins and the ratio between them differed throughout the rat brain. The shorter isoform was not detected in most of the examined peripheral tissues, suggesting differences from the CNS in post-transcriptional processing. Both isoforms repressed transcription in H293T cells using a Gal4-luciferase reporter system. However, the shorter isoform did not repress transcription as effectively as the longer isoform. Transfection of different ratios for both isoforms, in order to replicate the relative amounts observed throughout the CNS, supported an interaction between the isoforms. The net effect on transcriptional repression was determined by the ratio of the two NAC1 isoforms. Each isoform exhibited the subnuclear localization that is characteristic of many BTB/POZ proteins. A rapid and transient increase in the level of the shorter isoform occurred in the nucleus accumbens 2 h following a single i.p. cocaine injection. We conclude that the two isoforms of NAC1 may differentially affect neuronal functions, including the regulation of cocaine-induced locomotion.
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Saxena RK, Weissman D, Saxena QB, Simpson J, Lewis DM. Kinetics of changes in lymphocyte sub-populations in mouse lungs after intrapulmonary infection with M. bovis (Bacillus Calmette-Guerin) and identity of cells responsible for IFNgamma responses. Clin Exp Immunol 2002; 128:405-10. [PMID: 12067293 PMCID: PMC1906272 DOI: 10.1046/j.1365-2249.2002.01839.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Gamma interferon (IFNgamma) plays a key role in host defense against pulmonary mycobacterial infections. A variety of lymphocyte subsets may participate in producing pulmonary IFNgamma responses, but their relative contributions after mycobacterial infection have not been clearly elucidated. To address this question, C57Bl/6 female mice were infected by intrapulmonary instillation of 2.5 x 104 BCG (Mycobacterium bovis Bacillus Calmette-Guerin). Lymphocyte populations in lung interstitium were examined at different time points after the infection. BCG load in lungs peaked between 4 and 6 weeks post-infection and declined to very low levels by the 12th week of infection. Recovery of lung interstitial lymphocytes doubled by 4-6 weeks after infection and declined thereafter. Flow cytometric analysis of the lung-derived lymphocytes revealed that about 5% of the these cells made IFNgamma in control mice, and this baseline IFNgamma production involved T (CD3+NK1.1-), NK (CD3-NK1.1+) and NKT (CD3+NK1.1+) cells. As the BCG lung infection peaked, the total number of CD3+ T cells in the lungs increased threefold at 5-6 weeks post-infection. There was a marked increase (sixfold) in the number of T cells secreting IFNgamma 5-6 weeks post-infection. Some increase was also noted in the NKT cells making IFNgamma, but the numbers of NK cells making IFNgamma in BCG-infected lungs remained unaltered. Our results suggest that whereas NK and NKT cells contribute to baseline IFNgamma secretion in control lungs, expansion in the IFNgamma-producing T-cell population was essentially responsible for the augmented response seen in lungs of BCG-infected mice.
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Lewis DM. Responding to a violent incident: physical restraint or anger management as therapeutic interventions. J Psychiatr Ment Health Nurs 2002; 9:57-63. [PMID: 11896857 DOI: 10.1046/j.1351-0126.2001.00440.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
By finding more feasible alternatives to managing aggression which can be effectively used in health care settings, as well as expanding nursing knowledge on the detrimental effects of restraints, forensic clinicians can use their creativity and resources to enhance the quality of life for their patients using beneficial therapeutic alternatives to restraint. A closer examination of alternatives to managing aggressive behaviour leads the author to the introduction of a case study, promoting non-touch interventions. The importance of this paper lies in reorienting forensic clinicians away from the perceived ideologies of physical restraint as a primary intervention, moving towards the productive use of anger management.
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Lewis DM, Schuh WH, Wittgen CM. Infrainguinal vein graft surveillance: the criteria for intervention. JOURNAL OF VASCULAR NURSING 2001; 19:117-21. [PMID: 11734796 DOI: 10.1067/mvn.2001.120246] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In most patients, infrainguinal vein grafts are commonly performed for limb-threatening ischemia. Once limb salvage has been achieved, most clinicians agree that regular appointments with the vascular team are important to monitor graft patency. However, the timing of these appointments and what defines an adequate examination remains debatable. The following cases illustrate the natural history and interventions performed in 2 such patients. A review of the literature and a commentary on surveillance strategies is provided to elucidate the advantages and disadvantages of currently available vascular laboratory testing. Recommendations also are made for the appropriate timing of intervention to revise these grafts.
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Wang J, Lewis DM, Castranova V, Frazer DG, Goldsmith T, Tomblyn S, Simpson J, Stone S, Afshari A, Siegel PD. Characterization of asphalt fume composition under simulated road paving conditions by GC/MS and microflow LC/quadrupole time-of-flight MS. Anal Chem 2001; 73:3691-700. [PMID: 11510836 DOI: 10.1021/ac010334m] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A highly sensitive, selective, and reliable analytical method has been developed and validated for characterization of asphalt fume generated under simulated road paving conditions. A dynamic asphalt fume generation system was modified to provide consistent test atmospheres at simulated asphalt road paving conditions. In the process of fume generation, asphalt was initially preheated in an oven to 170 degrees C, pumped to a large kettle, which maintained the asphalt temperature between 150 and 170 degrees C, and then transferred to the generator. The fume was conducted from the generator to an exposure chamber through a heated transfer line. Characterization of the asphalt fume test atmospheres included the following: (1) determination of the consistency of the asphalt aerosol composition within the generation system; (2) quantification of total organic matter of the asphalt fume by electron impact ionization of isotope dilution gas chromatography/ mass spectrometry); and (3) identification of individual priority polycyclic aromatic hydrocarbons (PAHs) in asphalt fume by selected ion monitoring. With the developed method, asphalt fumes could be characterized into three fractions: (1) filter collection of a large molecular size fraction over a range of mass-to-charge (m/z) ratios of 173-309; (2) XAD-2 trapping of a medium molecular size fraction over a range of m/z ratios of 121-197; and (3) charcoal trapping of a small molecular size fraction that contained mainly the volatile vapor fraction over a range of m/z ratios of 57-141. Total organic matter of the asphalt fume was quantified over the 5 exposure days. Sixteen specific priority PAHs were monitored and identified. These PAHs were determined at trace levels on the filter fraction. A novel approach, which utilizes collision-induced dissociation of fragmentation pathway leading to a characteristic fragmentation pattern by coupling microflow liquid chromatography to atmospheric pressure chemical ionization of quadrupole time-of-flight mass spectrometry, was used to further clarify the trace amount of key components present in simulated road paving asphalt fumes. These results demonstrate that asphalt fume composition could be characterized and specific priority PAHs could be identified by this method. The major advantages of this method are its highly sensitivity, selectivity, and reliability for chemical hazard characterization in a complex mixture. This method is suitable for support toxicity studies using simulated occupational exposure to asphalt fumes.
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Abstract
The importance of predation in regulating the size of competing plankton and larval fish populations has long been appreciated. However, it has only recently been recognized that turbulence must have a significant influence on predator-prey interactions because most rival species of microorganisms co-exist in oceanic or fast moving fresh water flows. Turbulence is likely to influence predation strategies in two ways. The extra energy imparted to a micro-organism from the flow field will enhance the number of encounters or "contacts" between predators and prey. At the same time, because the velocity of a predator relative to its potential prey will be increased, the time-scale over which a capture must be completed is reduced. Balancing the benefits of extra encounters with the drawbacks of more difficult captures, will dictate an optimal predation strategy, either foraging behaviour or ambush feeding, on the predator. This will depend on its own and the prey's swimming capabilities, as well as the characteristics of the turbulent environment. In this paper some previous work, examining the increased encounter rate in turbulence, will be extended to look at the capture problem. The main proposal is that the capture event should be encapsulated in a capture probability function, from which the optimal predation strategy can be derived. As an illustration, plausible capture probability functions will be postulated and the resulting predictions tested against numerical simulations carried out in a turbulent-like flow field. Good agreement between the predictions and the simulations is demonstrated.
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Tribble DL, Rizzo M, Chait A, Lewis DM, Blanche PJ, Krauss RM. Enhanced oxidative susceptibility and reduced antioxidant content of metabolic precursors of small, dense low-density lipoproteins. Am J Med 2001; 110:103-10. [PMID: 11165551 DOI: 10.1016/s0002-9343(00)00700-2] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
PURPOSE Elevated plasma concentrations of low-density lipoproteins (LDL) increase risk for coronary heart disease. However, lipoprotein profiles rich in small, dense LDL particles confer greater risk than those that mainly consist of large, buoyant LDL. This may be due, in part, to the greater oxidative susceptibility of small, dense LDL. In the current studies, we tested whether differences in the oxidative behavior of buoyant and dense LDL arise from differences in their immediate metabolic precursors, intermediate-density lipoproteins. SUBJECTS AND METHODS We compared the properties of intermediate-density lipoproteins and buoyant and dense LDL subfractions in 9 subjects with the large, buoyant LDL phenotype versus 6 with the small, dense LDL phenotype. Oxidative susceptibility was evaluated based on conjugated diene formation and parinaric acid oxidation induced by copper. Antioxidants (ubiquinol-10 and alpha-tocopherol) were measured by high-performance liquid chromatography. RESULTS Oxidative susceptibility was increased and antioxidant concentrations were decreased with increasing lipoprotein density (intermediate intermediate-density lipoproteins to buoyant LDL to dense LDL). Intermediate-density lipoproteins from subjects with the small, dense LDL phenotype had a greater oxidative susceptibility (by the parinaric acid test) and lower antioxidant concentrations than corresponding particles from subjects with the large, buoyant LDL phenotype. CONCLUSIONS Differences in oxidative susceptibility between large, buoyant and small, dense LDL particles are apparent in their lipoprotein precursors. These results suggest that lipoprotein oxidative susceptibility may be metabolically programmed and that intermediate-density lipoproteins may contribute to the increased risk associated with the small, dense LDL phenotype.
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Brenton AG, Dutton J, Harris FM, Jones RA, Lewis DM. Experimental determination of total scattering cross sections for positron-helium collisions. ACTA ACUST UNITED AC 2001. [DOI: 10.1088/0022-3700/10/13/023] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Fan QG, Lewis DM, Tapley KN. Characterization of cellulose aldehyde using Fourier transform infrared spectroscopy. J Appl Polym Sci 2001. [DOI: 10.1002/app.1953] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Abstract
Sports medicine practitioners must be sensitive to even the smallest injuries that affect athletes. Often, less severe ligament injuries go undetected. Scapholunate dissociation is often overlooked in this manner. The authors provide an overview of presentation, diagnosis, and nonoperative and operative treatments of this condition.
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Abstract
Cohort differences in body image, drive for thinness, and eating attitudes in middle-aged and elderly women were examined. Participants were 125 women between the ages of 50 and 65 (middle-aged group), and 125 women 66 years old and older (elderly group). Instruments used were figure ratings (Stunkard, Sorensen, & Schulsinger, 1983), and scales of the Eating Disorder Inventory (EDI; Garner,Olmstead, & Polivy, 1983). Items were developed to assess fear of aging. The middle-aged group, as compared to the elderly group, had more drive for thinness, disinhibited eating, and interoceptive confusion. The elderly group reported body size preferences and levels of body dissatisfaction that were similar to the younger women. There was a positive relationship between fear of aging and disordered eating. Sociocultural standards of body image and pressures toward thinness affect different generations of older women in similar ways.
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Breault LG, Fowler EB, Wolfgang MJ, Lewis DM. Peripheral giant cell granuloma: a case report. GENERAL DENTISTRY 2000; 48:716-9. [PMID: 12004669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
The peripheral giant cell granuloma is a reactive lesion of the soft tissue of the oral cavity. Clinical appearance ranges from normal tissue coloration to dark red or purplish. These are elevated lesions generally 5-15 mm in diameter. Etiology is considered to be chronic irritation. To decrease the risk of clinical recurrence, treatment is complete excision to include the underlying periosteum. Histologic features of the peripheral giant cell granuloma include multinucleated giant cells with a stroma that may contain osteoblasts, myofibroblasts, macrophages, and Langerhans cells. A case report is presented.
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Petsonk EL, Wang ML, Lewis DM, Siegel PD, Husberg BJ. Asthma-like symptoms in wood product plant workers exposed to methylene diphenyl diisocyanate. Chest 2000; 118:1183-93. [PMID: 11035694 DOI: 10.1378/chest.118.4.1183] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
BACKGROUND Diisocyanates, a group of highly reactive chemicals, have frequently been associated with occupational asthma. We evaluated respiratory health in workers at a new wood products manufacturing plant that uses methylene diphenyl diisocyanate (MDI), and was designed and operated with a goal of minimizing worker exposures. METHODS Health surveys using standardized respiratory questionnaires were done prior to the initial use of diisocyanates in the plant, and semiannually thereafter for a period of 2 years. Other testing included occupational and work practice histories, serial peak flow measurements, spirometry, methacholine challenge, and measurement of specific IgE antibodies to MDI-albumin conjugate. RESULTS Of 214 plant employees who participated in at least one health survey, a follow-up survey was also available from 178 employees (83%). New-onset asthma-like symptoms (NAS) were reported by 15 of 56 workers (27%) in areas with the highest potential for exposures to liquid MDI monomer and prepolymer, vs 0 of 43 workers in the lowest potential exposure areas (p = 0.001). In the areas with high potential exposure, NAS developed in 47% of workers who had noted MDI skin staining, vs 19% without skin stains (p = 0.07). Working around and cleaning up liquid MDI represented a significant risk for asthma-like symptoms in both current smokers and nonsmokers; work with finished wood products did not. Asthma-like symptoms were associated with variable airflow limitation (odds ratio [OR], 5.0; confidence interval [CI], 1.4 to 18.7) and specific IgE to MDI-albumin (OR, 3.2; CI, 1.1 to 9.0), but not with skin prick tests to common aeroallergens (OR, 1.1; CI, 0.5 to 2.7). CONCLUSIONS During the first 2 years of operation, in a plant designed and operated to control exposure to diisocyanates, the development of asthma-like symptoms was reported in a relatively high proportion of the employees who worked with liquid MDI. To prevent asthma symptoms among workers, careful control of respiratory tract exposures associated with liquid MDI is important, especially during cleanup activities. Strict limitation of skin contact with diisocyanates may also be necessary.
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Lewis DM, Pedley TJ. Planktonic contact rates in homogeneous isotropic turbulence: theoretical predictions and kinematic simulations. J Theor Biol 2000; 205:377-408. [PMID: 10882560 DOI: 10.1006/jtbi.2000.2073] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The key role played by turbulence in the environment of plankton and larval fish populations has become appreciated in recent years. In particular, the turbulent enhancement of encounter rates between different species of microorganisms, either swimming or passively advected by the flow, is well established. However, most of the current modelling approaches are rather ad hoc, giving rise to ambiguities in the specification of certain key parameters. In this paper, the encounter problem in a turbulent flow of large Reynolds number is re-examined from first principles and a number of new formulae will be established for different swimming strategies. The key innovation is the proposal of a model form for the conditional joint probability density function of predator and prey velocities when the organisms are separated by their given contact radius, R. Particular attention will be paid to the case when a microorganism follows a random trajectory, due to a combination of its own swimming and the action of the flow. The theoretical predictions are subsequently tested against corresponding quantities derived from a series of kinematic simulations of a turbulent-like flow field. Good agreement is demonstrated between the predictions and simulations.
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Simon EP, Lewis DM. Medical hypnosis for temporomandibular disorders: treatment efficacy and medical utilization outcome. ORAL SURGERY, ORAL MEDICINE, ORAL PATHOLOGY, ORAL RADIOLOGY, AND ENDODONTICS 2000; 90:54-63. [PMID: 10884636 DOI: 10.1067/moe.2000.106692] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
AIM The aim of this study was to examine the effectiveness of a particular behavioral medicine treatment modality, medical hypnosis, on reducing the pain symptoms of temporomandibular disorders (TMD). METHODS Twenty-eight patients who were recalcitrant to conservative treatment for TMD participated in a medical hypnosis treatment program and completed measures of their pain symptoms on 4 separate occasions: during wait list, before treatment, after treatment, and at a 6-month follow-up. In addition, pretreatment and posttreatment medical use were examined. RESULTS Statistical analysis of this open trial suggests that medical hypnosis is a potentially valuable treatment modality for TMD. Patients reported a significant decrease in pain frequency (F [3, 87] = 14.79, P<.001), pain duration (F [3, 87] = 9.56, P<.001), and pain intensity (F [3, 87] = 15.08, P<. 001), and an increase in daily functioning. Analysis suggests that their symptoms did not simply spontaneously improve, and that their treatment gains were maintained for 6 months after hypnosis treatment. Further, after hypnosis treatment, patients exhibited a significant reduction in medical use. CONCLUSION Medical hypnosis appears to be an effective treatment modality for TMD, in terms of reducing both symptoms and medical use.
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Page EH, Esswein EJ, Petersen MR, Lewis DM, Bledsoe TA. Natural rubber latex: glove use, sensitization, and airborne and latent dust concentrations at a Denver hospital. J Occup Environ Med 2000; 42:613-20. [PMID: 10874654 DOI: 10.1097/00043764-200006000-00010] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Exposure to natural rubber latex may cause immediate hypersensitivity reactions. Published latex sensitization prevalence rates range from 2.9% to 22% among health care workers, and from 0.12% to about 20% of occupationally unexposed populations. In this study, self-administered questionnaires addressed job and personal characteristics, glove use, and symptoms in two groups of hospital workers: those who regularly used latex gloves and those who did not. Serum was tested for latex-specific immunoglobulin E. Air, surface, and air-filter dust samples for natural rubber latex were collected. The prevalence of latex sensitization was 6.3% in the non-users and 6.1% in the latex glove users (P = 0.9); 81.3% of sensitized workers were atopic compared with 59.5% of non-sensitized workers (P < 0.05). Reporting of work-related hand dermatitis was more common in the latex glove users (23.4%) than in the non-users (4.9%), as were rhino-conjunctivitis (16.3% and 7.9%, respectively, [P < 0.01]), and hand urticaria (9.9% and 2.1%, respectively, [P < 0.01]). There was no significant difference in work-related symptoms between the sensitized and non-sensitized workers. Environmental concentrations of latex were higher in the work areas of the non-sensitized workers, but higher in the clinical than in the non-clinical areas. Occupational latex glove use was not a risk factor for sensitization.
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Kerr CM, Lewis DM. Factors influencing the documentation of care. PROFESSIONAL NURSE (LONDON, ENGLAND) 2000; 15:516-9. [PMID: 12026764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Nursing care plans should provide clear evidence of the quality of patient care provided. A study of a care plan used in a coronary care unit found that nurses were critical of the plan's format. Nurses need adequate education on the use of the chosen care plan and an understanding of the nursing model on which it is based.
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Shahan TA, Sorenson WG, Simpson J, Kefalides NA, Lewis DM. Tyrosine kinase activation in response to fungal spores is primarily dependent on endogenous reactive oxygen production in macrophages. J Biol Chem 2000; 275:10175-81. [PMID: 10744701 DOI: 10.1074/jbc.275.14.10175] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Studies from our laboratory (Shahan, T. A., Sorenson, W. G., and Lewis, D. M. (1994) Environ. Res. 67, 98-104) demonstrated that spores from different fungal species differentially activate rat alveolar macrophages as detected by the measurement of superoxide anion and cytokine production (Shahan, T. A., Siegel, P. D., Sorenson, W. G., Kuschner, W. G., and Lewis, D. M. (1998) Am. J. Respir. Cell Mol. Biol. 18, 435-441). Spores from Aspergillus candidus stimulated production of the highest levels of superoxide anion (5.2 nmol/1.0 x 10(6) alveolar macrophages (AMs)/30 min), followed by those from Aspergillus niger (2.4 nmol/1.0 x 10(6) AMs/30 min) and Eurotium amstelodami (0.4 nmol/1.0 x 10(6) AMs/30 min). The mechanism of this differential activation was studied. Our data demonstrate that the tyrosine kinases p56(Hck), p72(Syk), p77(Btk), p62(Yes), p56(Lck), and p59(Fyn) were specifically activated in response to spores from A. candidus, whereas spores from either A. niger or E. amstelodami activated p56(Hck), p72(Syk), and p77(Btk). Kinetic analysis of specific tyrosine kinases demonstrated that p56(Hck), p72(Syk), and p77(Btk) were activated faster and to a greater extent by spores from A. candidus as compared with spores from E. amstelodami. These data suggest a relationship between reactive oxygen species and tyrosine kinase activation. Treatment of AMs with H(2)O(2) (1 mM) caused the activation of p72(Syk) only, whereas treatment with superoxide dismutase and catalase before treatment with the spores had no effect on tyrosine kinase activation. Incubation with NADPH oxidase inhibitors inhibited both superoxide anion production and the activation of p56(Hck), p72(Syk), and p77(Btk) in response to fungal spores. These data indicate that endogenous reactive oxygen species are necessary for the activation of p56(Hck), p72(Syk), and p77(Btk) by spores; they also indicate that some species of spores are capable of activating tyrosine kinases independent of superoxide anion.
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Abstract
The mitotic activity in muscles of growing rats and the effect of denervation were studied by means of continuous infusion of 5-bromo-2-deoxyuridine (BRDU). Denervated muscles after 10 weeks contained 20 to 60% fewer muscle nuclei than normal; BRDU labeled about 25% of the nuclei of normal soleus and extensor digitorum longus (EDL) and of denervated EDL muscles but only 5% in the denervated soleus muscle. Labeled nuclei persisted in denervated but not in normal muscles. After the main growth period, the turnover of myonuclei was at most 1 to 2% per week. The behavior of connective tissue nuclei was similar to that in muscle fibers. Infusion of BRDU had no effect on contractile properties. It is suggested that the exceptionally rapid atrophy of the denervated rat soleus associated with loss of satellite cells was due to loss of myonuclei and differentiation and fusion of satellite cells. The cause may possibly be that the phase of postdenervation fibrillation is shorter than in other muscles.
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Weissman DN, Lewis DM. Is specific antibody determination diagnostic for asthma attributable to low-molecular-weight agents? OCCUPATIONAL MEDICINE (PHILADELPHIA, PA.) 2000; 15:385-98. [PMID: 10769344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
It is important to understand a medical testís performance characteristics, so that it can be used appropriately. Performance characteristics of tests for antibodies specific to low-molecular-weight (LMW) agents in predicting asthma caused by these agents differ in the study population. In general, currently published data supporting the use of tests to detect specific IgE and IgG to LMW agents in the diagnosis of occupational asthma is limited and inconclusive. However, a few general statements can be made. The most promising results have been achieved for agents such as acid anhydrides and platinum salts, where specific IgE responses appear to play a significant pathogenic role in causing occupational asthma. Results have been less promising for agents such as isocyanates and plicatic acid, for which antibody responses do not appear to underlie the development of asthma in most individuals. In the case of isocyanates, determination of antigen-specific IgG might have some utility as a biomarker of exposure.
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Wrosch J, Morgan LK, Sullivant J, Lewis DM. Instruction of evidence-based medicine searching skills during first-year epidemiology. Med Ref Serv Q 2000; 17:49-57. [PMID: 10621389 DOI: 10.1300/j115v17n03_06] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Chun DT, Chew V, Bartlett K, Gordon T, Jacobs RR, Larsson BM, Larsson L, Lewis DM, Liesivuori J, Michel O, Milton DK, Rylander R, Thorne PS, White EM, Brown ME. Preliminary report on the results of the second phase of a round- robin endotoxin assay study using cotton dust. APPLIED OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2000; 15:152-7. [PMID: 10712070 DOI: 10.1080/104732200301971] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
In an on-going endotoxin assay study, a two-part interlaboratory endotoxin assay study has been completed. The purpose of the study was to compare the variation in assay results between different laboratories, and, if the variation was high, to see if a common protocol would reduce the variation. In both parts of the study, membrane filters laden with the same approximate amount and type of cotton dust were sent for analysis to laboratories that "routinely" perform endotoxin analyses. First, each of these laboratories performed the analysis using the methodology common to its laboratory. In the second part of the study, membrane filters with cotton dust were again sent to the same laboratories where the analyses were performed as before but with a common extraction protocol. The preliminary results from the first phase of the study have been collected and showed that intra-laboratory variations were small, but large and significant interlaboratory variation was observed. The results were reported elsewhere. The preliminary results from the second part of the study consisting of the data currently collected are presented here. Again, intra-laboratory variations were small, but, also again, large and significant inter-laboratory variation was observed. However, in this part of the study, the range between the highest and lowest average results was narrower than in the first part of the study. Influence of the assay kit type was examined. The variation within assay kit type was small but significant differences in results were observed between assay kit types. The findings suggest that endotoxin concentration in samples can be ranked within laboratories, but not necessarily between laboratories. However, some of the variation between laboratories has been reduced by a common extraction protocol which suggests the possibility of further standardization that may lead to better comparability between laboratories.
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Lewis DM, Bingham C, Beaman M, Nicholls AJ, Riad HN. Polypropylene mesh hernia repair--an alternative permitting rapid return to peritoneal dialysis. Nephrol Dial Transplant 1998; 13:2488-9. [PMID: 9794549 DOI: 10.1093/ndt/13.10.2488] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Lewis DM, Tooke JE, Beaman M, Gamble J, Shore AC. Peripheral microvascular parameters in the nephrotic syndrome. Kidney Int 1998; 54:1261-6. [PMID: 9767542 DOI: 10.1046/j.1523-1755.1998.00100.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Peripheral edema, in combination with severe proteinuria and low serum albumin levels, is pathognomonic of the nephrotic syndrome, yet the exact mechanism of its formation is unknown. Two of the most important of the factors in Starling's forces controlling fluid filtration across the capillary have hitherto not been studied in nephrotic subjects. METHODS The hydrostatic capillary pressure at the finger nail-fold in actively nephrotic subjects and age and sex matched controls was studied, using direct puncture of the apex of the capillary under video microscopy, and a servonulling apparatus to give a direct measurement of capillary pressure. Capillary filtration capacity (CFC) at the calf was measured noninvasively by a modern derivative of the technique of mercury strain gauge plethysmography. Fifteen nephrotic subjects with a variety of underlying pathological lesions, and age matched controls were studied. RESULTS Contrary to the assumption of the "overflow" hypothesis of edema formation, there was no evidence of capillary hypertension. The capillary pressure showed no difference between nephrotic subjects and controls: median (range) of 17.6 (12.0 to 24.2) compared with 17.3 (9.0 to 21.6) mm Hg, P = NS. CFC was significantly higher in nephrotic subjects than controls [5.23 (3.28 to 8.52) x 10(-3) versus 3.55 (2.43 to 5.28) x 10(-3) ml/min/100 g/mm Hg, P < 0.01]. CONCLUSIONS An increase in CFC provides a potentially novel mechanism contributing at least in part to the formation of peripheral edema in the nephrotic syndrome.
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Mahy IR, Lewis DM, Tooke JE. Limb capillary filtration coefficient in human subjects: the importance of the site of measurement. Physiol Meas 1998; 19:339-43. [PMID: 9735884 DOI: 10.1088/0967-3334/19/3/002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Capillary filtration coefficient is a critical determinant of fluid flux across the microvascular wall. Changes in capillary filtration coefficient have been described in a number of disease processes. Measurement is typically made by venous occlusion plethysmography using either the upper or lower limb, but a variety of measurement protocols have been used and the importance of the site of measurement remains unclear. In this study, forearm and calf capillary filtration coefficient were measured in healthy volunteers, either simultaneously (group A; n = 11) or sequentially in random order (group B; n = 11) using venous occlusion plethysmography, with the subject supine and the limb at heart level. In both studies capillary filtration coefficient was significantly higher when measured at the forearm than at the calf (group A: 6.1 +/- 1.0 versus 3.7 +/- 1.1 x 10(-3) ml min(-1) mmHg(-1) 100 ml(-1) (mean +/- SD), p < 0.01; group B: 5.1 +/- 1.2 versus 3.2 +/- 1.1 x 10(-3) ml min(-1) mmHg(-1) 100 ml(-1), p < 0.01). Isovolumetric venous pressure (the maximum pressure at which there is neither net filtration nor absorption at the microvascular wall) was similar in upper and lower limbs in both groups of subjects. We conclude that limb capillary filtration coefficient is dependent on the site of measurement. Caution is required when comparing data recorded at different sites even if corrected for the volume of soft tissue under study.
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