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Johnson ME, Hauser PM. The practices of expert psychiatric nurses: accompanying the patient to a calmer personal space. Issues Ment Health Nurs 2001; 22:651-68. [PMID: 11881180 DOI: 10.1080/016128401750434464] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The focus of the care of potentially aggressive psychiatric patients has been on the use of seclusion and restraints. Recent concerns, however, about the potential for patient injury have made it imperative that nurses use alternative methods to calm patients who are escalating. Little is known about how expert nurses de-escalate the escalating patient. The purpose of this interpretive phenomenological study was to uncover and describe the knowledge embedded in the stories of psychiatric nurses who are skilled in the practices of de-escalating an escalating patient. Twenty registered nurses were interviewed using an unstructured format. The analysis of the data revealed that these nurses were skilled at noticing the patient, reading the situation and the patient, knowing where the patient was on the continuum, understanding the meaning of the behavior, knowing what the patient needed, connecting with the patient, and matching the intervention with the patient's needs.
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Park S, Mehboob S, Luo BH, Hurtuk MG, Johnson ME, Fung LWM. Molecular Studies of the Erythrocyte Spectrin Tetramerization Region. Cell Mol Biol Lett 2001; 6:224. [PMID: 11544675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023] Open
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Somers EB, Johnson ME, Wong AC. Biofilm formation and contamination of cheese by nonstarter lactic acid bacteria in the dairy environment. J Dairy Sci 2001; 84:1926-36. [PMID: 11573770 DOI: 10.3168/jds.s0022-0302(01)74634-6] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Defects in cheese, such as undesirable flavors, gas formation, or white surface haze from calcium lactate crystals, can result from growth of nonstarter lactic acid bacteria (NSLAB). The potential for biofilm formation by NSLAB during cheese manufacturing, the effect of cleaning and sanitizing on the biofilm, and bacterial growth and formation of defects during ripening of the contaminated cheese were studied. Stirred-curd Cheddar cheese was made in the presence of stainless steel chips containing biofilms of either of two strains of erythromycin-resistant NSLAB (Lactobacillus curvatus strain JBL2126 or Lactobacillus fermentum strain AWL4001). During ripening, the cheese was assayed for total lactic acid bacteria, numbers of NSLAB, and percentage of lactic acid isomers. Biofilms of L. curvatus formed during cheese making survived the cleaning process and persisted in a subsequent batch of cheese. The starter culture also survived the cleaning process. Additionally, L. curvatus biofilms present in the vat dislodged, grew to high numbers, and caused a calcium lactate white haze defect in cheese during ripening. On the other hand, biofilms of L. fermentum sloughed off during cheese making but could not compete with other NSLAB present in cheese during ripening. Pulsed-field gel electrophoresis results verified the presence of the two biofilm strains during cheese making and in the ripening cheese. Probable contamination sites in the plant for other NSLAB isolated in the cheese were identified, thus supporting the hypothesis that resident NSLAB biofilms are a viable source of contamination in the dairy environment.
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Rogers MW, Hedman LD, Johnson ME, Cain TD, Hanke TA. Lateral stability during forward-induced stepping for dynamic balance recovery in young and older adults. J Gerontol A Biol Sci Med Sci 2001; 56:M589-94. [PMID: 11524454 DOI: 10.1093/gerona/56.9.m589] [Citation(s) in RCA: 107] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Balance dysfunction related to lateral instability has been associated with falls and fall-related injuries among older individuals. Protective stepping for dynamic balance recovery requires the effective control of lateral body motion. This study investigated the relationship between aging, falls, and lateral stability during forward-induced stepping for dynamic balance recovery. METHODS Forward steps were induced by a motor-driven waist-pull system in 12 younger adults, 20 healthy community-dwelling older adult nonfallers, and 18 older adults who had reported falls. Group differences in kinetic and kinematic stepping characteristics for a range of postural disturbance magnitudes were evaluated. RESULTS Despite group similarities in anticipatory postural adjustments for minimizing lateral instability, the older fallers demonstrated significantly greater sideways body motion toward the stepping side at first-step foot contact and a more laterally directed foot placement. During the first step, forward-stepping characteristics were generally comparable between the groups, but the older fallers had an earlier liftoff time and longer step duration. CONCLUSIONS During forward-induced protective stepping, otherwise healthy older adults who had experienced falls showed particular differences in their control of lateral body motion that were not attributable to changes in anticipatory postural mechanisms. Aging changes in controlling lateral body motion during protective stepping appear to involve factors that intervene between the first-step liftoff and foot contact and/or adaptations in stepping patterns related to prior planning.
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Johnson ME. Neurotoxicity of spinal procaine[mdash ]a caution. Reg Anesth Pain Med 2001; 26:288. [PMID: 11359235 DOI: 10.1053/rapm.2001.23216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Johnson ME, Chen CM, Jaeggi JJ. Effect of rennet coagulation time on composition, yield, and quality of reduced-fat cheddar cheese. J Dairy Sci 2001; 84:1027-33. [PMID: 11384028 DOI: 10.3168/jds.s0022-0302(01)74562-6] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
This study compared the effect of coagulum firmness at cutting on composition of 50% reduced-fat Cheddar cheese. Coagulum firmness was determined by subjective evaluation by the cheese maker. Three firmness levels were tested, and these corresponded to average times of coagulant addition to cutting the curd of 25, 48, and 65 min. A slow acid-producing culture was used, and ripening times were altered to give similar curd pH values throughout cheese making. A longer rennet coagulation time (firmer coagulum at cutting) resulted in an increase in cheese moisture as well as an increase in cheese yield. The percentages of fat recovered in the cheese decreased with increasing curd firmness. The percentage of nitrogen recovered in the cheese was similar among the treatments. The amount of whey collected from the curd after milling increased as the coagulum firmness at cutting increased. Higher moisture content and lower pH of cheese made from the firmer curd at cutting contributed to softer, smoother-bodied cheeses, but the Cheddar flavor intensity was not affected.
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Strickland M, Johnson ME, Broadbent JR. Qualitative and quantitative analysis of proteins and peptides in milk products by capillary electrophoresis. Electrophoresis 2001; 22:1510-7. [PMID: 11386663 DOI: 10.1002/1522-2683(200105)22:8<1510::aid-elps1510>3.0.co;2-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Milk protein is an important component of the human diet throughout much of the world. The ability to assess the relative composition and integrity of milk proteins or peptides in dairy foods or food ingredients is important because these molecules have a profound effect on product functionality and quality. This communication describes two capillary electrophoretic methods that are useful for the analysis of proteins and casein-derived peptides in cheese and milk products. One technique, which uses a buffer containing citrate/phosphate (pH 3.3), 4 M urea, and a polymeric additive in a coated capillary, is useful for qualitative and quantitative analysis of proteins and peptides in milk, cheese, and whey products. The second method employs a citrate/phosphate buffer (pH 2.8) and a bare silica capillary, and is well suited for the analysis of small, casein-derived peptides in aqueous cheese extracts.
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Fiechtner BK, Nuttall GA, Johnson ME, Dong Y, Sujirattanawimol N, Oliver WC, Sarpal RS, Oyen LJ, Ereth MH. Plasma tranexamic acid concentrations during cardiopulmonary bypass. Anesth Analg 2001; 92:1131-6. [PMID: 11323334 DOI: 10.1097/00000539-200105000-00010] [Citation(s) in RCA: 128] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
UNLABELLED Although tranexamic acid is used to reduce bleeding after cardiac surgery, there is large variation in the recommended dose, and few studies of plasma concentrations of the drug during cardiopulmonary bypass (CPB) have been performed. The plasma tranexamic acid concentration reported to inhibit fibrinolysis in vitro is 10 microg/mL. Twenty-one patients received an initial dose of 10 mg/kg given over 20 min followed by an infusion of 1 mg. kg(-1). h(-1) via a central venous catheter. Two patients were removed from the study secondary to protocol violation. Perioperative plasma tranexamic acid concentrations were measured with high-performance liquid chromatography. Plasma tranexamic acid concentrations (microg/mL; mean +/- SD [95% confidence interval]) were 37.4 +/- 16.9 (45.5, 29.3) after bolus, 27.6 +/- 7.9 (31.4, 23.8) after 5 min on CPB, 31.4 +/- 12.1 (37.2, 25.6) after 30 min on CPB, 29.2 +/- 9.0 (34.6, 23.8) after 60 min on CPB, 25.6 +/- 18.6 (35.1, 16.1) at discontinuation of tranexamic acid infusion, and 17.7 +/- 13.1 (24.1, 11.1) 1 h after discontinuation of tranexamic acid infusion. Four patients with renal insufficiency had increased concentrations of tranexamic acid at discontinuation of the drug. Repeated-measures analysis revealed a significant main effect of abnormal creatinine concentration (P = 0.02) and time (P < 0.001) on plasma tranexamic acid concentration and a significant time x creatinine concentration interaction (P < 0.001). IMPLICATIONS A 10 mg/kg initial dose of tranexamic acid followed by an infusion of 1 mg.kg(-1).h(-1)produced plasma concentrations throughout the cardiopulmonary bypass period sufficient to inhibit fibrinolysis in vitro. The dosing of tranexamic acid may require adjustment for renal insufficiency.
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Minnick A, Leipzig RM, Johnson ME. Elderly patients' reports of physical restraint experiences in intensive care units. Am J Crit Care 2001; 10:168-71. [PMID: 11340739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
BACKGROUND Use of physical restraints has undesirable sequelae. As they weigh the risks and benefits of protocols for reducing the use of restraints, staff members in intensive care units, where restraints are most used in hospitals, need to know how well elderly patients remember being restrained and how patients perceive the use of restraints. OBJECTIVES To estimate the proportion of patients who remember being restrained, describe the experience from the patients' perspectives, and describe any distress caused by use of restraints within the overall experience of being in the intensive care unit. METHODS Transcripts of semistructured, audiotaped interviews of patients who had been in the medical or surgical intensive care unit in any of 3 eastern and midwestern medical centers were analyzed by question and for overall themes. RESULTS Six patients (40%) remembered some aspect of being restrained but did not report great distress. Patients accepted restraints as needed because of the lack of alternatives. Patients reported remembering that they should not perform certain behaviors but being unable to stop themselves. Patients cited hallucinations and intubation as major stressors in the intensive care unit. Patients' continuing health problems after discharge from the intensive care unit severely limited recruitment of subjects. CONCLUSIONS Patients do not remember great distress specifically related to the use of restraints, but the overall situation leading to use of restraints is disturbing if remembered. The discovery of methods to reduce the distress of intubation and hallucinations could decrease use of restraints.
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Minnick A, Leipzig RM, Johnson ME. Elderly patients' reports of physical restraint experiences in intensive care units. Am J Crit Care 2001. [DOI: 10.4037/ajcc2001.10.3.168] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
BACKGROUND: Use of physical restraints has undesirable sequelae. As they weigh the risks and benefits of protocols for reducing the use of restraints, staff members in intensive care units, where restraints are most used in hospitals, need to know how well elderly patients remember being restrained and how patients perceive the use of restraints. OBJECTIVES: To estimate the proportion of patients who remember being restrained, describe the experience from the patients' perspectives, and describe any distress caused by use of restraints within the overall experience of being in the intensive care unit. METHODS: Transcripts of semistructured, audiotaped interviews of patients who had been in the medical or surgical intensive care unit in any of 3 eastern and midwestern medical centers were analyzed by question and for overall themes. RESULTS: Six patients (40%) remembered some aspect of being restrained but did not report great distress. Patients accepted restraints as needed because of the lack of alternatives. Patients reported remembering that they should not perform certain behaviors but being unable to stop themselves. Patients cited hallucinations and intubation as major stressors in the intensive care unit. Patients' continuing health problems after discharge from the intensive care unit severely limited recruitment of subjects. CONCLUSIONS: Patients do not remember great distress specifically related to the use of restraints, but the overall situation leading to use of restraints is disturbing if remembered. The discovery of methods to reduce the distress of intubation and hallucinations could decrease use of restraints.
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Rausch JL, Hobby HM, Shendarkar N, Johnson ME, Li J. Fluvoxamine treatment of mixed anxiety and depression: evidence for serotonergically mediated anxiolysis. J Clin Psychopharmacol 2001; 21:139-42. [PMID: 11270909 DOI: 10.1097/00004714-200104000-00004] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Although increasing evidence suggests that selective serotonin reuptake inhibitor (SSRI) treatment may be effective for anxiety in addition to depression, SSRI anxiolysis has not been definitively related to the inhibition of serotonin (5-HT) transport. The gene that encodes for the human serotonin transporter (5-HTT) expresses its protein in neurons and in blood platelets, and both tissues respond to transport inhibition similarly in response to SSRI treatment. This study examined the relationship between the change in the 5-HTT's apparent affinity for 5-HT and the anxiolytic response in a group of 18 fluvoxamine-treated patients meeting Structured Clinical Interview for DSM-IV criteria for both generalized anxiety disorder and major depression. Significant decreases were found in both Hamilton anxiety and Hamilton depression scores over a 2-month treatment period. Robust increases were found in the apparent affinity constant (Km) for platelet 5-HT transport with treatment, and the increases covaried significantly with the decrease in anxiety (F = 4.97, p < 0.03). The pretreatment 5-HTT Km significantly correlated with the improvement in depression scores (r = 0.53, p < 0.03), consistent with the Hypothesis of Initial Conditions. These results suggest that the therapeutic effect of SSRI treatment can be linked to the magnitude and time-course of 5-HT transport inhibition effected with fluvoxamine, a drug that seems to have an antianxiety effect of the same magnitude as its effect on depression.
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Rea D, Johnson ME, Havenga MJ, Melief CJ, Offringa R. Strategies for improved antigen delivery into dendritic cells. Trends Mol Med 2001; 7:91-4. [PMID: 11286763 DOI: 10.1016/s1471-4914(01)01948-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Efficacious vaccines against cancers and infectious diseases will, in general, need to elicit comprehensive immune responses, including cytotoxic T lymphocyte activity. Because of their unique T cell stimulatory capacities, dendritic cells (DC) have emerged as the most potent antigen-presenting cell. Vaccination strategies should therefore aim at the acquisition and display of the antigen(s) of choice by DC. Results from vaccination studies, in animal models and in humans, stress the need for optimized antigen delivery systems to DC, to increase vaccination efficacy as well as to improve control on the immunological outcome. Here, we discuss the advantages and limitations of several recently described methodologies for antigen delivery into DC.
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Park S, Johnson ME, Fung LW. NMR analysis of secondary structure and dynamics of a recombinant peptide from the N-terminal region of human erythroid alpha-spectrin. FEBS Lett 2000; 485:81-6. [PMID: 11086170 DOI: 10.1016/s0014-5793(00)02186-4] [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: 11/24/2022]
Abstract
We have studied the nuclear magnetic resonance solution secondary structure of the N-terminal region in human erythroid alpha-spectrin using a recombinant model peptide of alpha-spectrin consisting of residues 1-156. Pulsed field gradient diffusion coefficient measurements show that the model peptide exists as a monomer under the solution conditions used. The first 20 residues are in a random coil conformation, followed by a helix of 25 residues and then a random coil segment before the next helix. The random coil nature of this linker was confirmed by the presence of fast internal motion from (15)N relaxation measurements. The second, third and fourth helices are thought to form the triple helical bundle structural domain, consistent with previous studies. Our study shows that the N-terminal region of alpha-spectrin prior to the first structural domain forms a well behaved helix without its beta-spectrin partner.
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Trubatch BN, Fisher DG, Cagle HH, Fenaughty AM, Johnson ME. Nonprescription pharmacy sales of needles and syringes. Am J Public Health 2000; 90:1639-40. [PMID: 11030005 PMCID: PMC1446366 DOI: 10.2105/ajph.90.10.1639] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Johnson ME, Stewart GP, Nielsen CJ, Hatton JF. Evaluation of root reinforcement of endodontically treated teeth. ORAL SURGERY, ORAL MEDICINE, ORAL PATHOLOGY, ORAL RADIOLOGY, AND ENDODONTICS 2000; 90:360-4. [PMID: 10982959 DOI: 10.1067/moe.2000.108951] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVES The purpose of this study was to test the root reinforcing capabilities of a glass ionomer sealer and to test whether pretreatment of the instrumented canal to alter or remove the smear layer might enhance the reinforcement. STUDY DESIGN Ninety single-canaled roots of standardized dimensions were instrumented to International Standards Organization size 45 and were analyzed for resistance to vertical fracture. Six groups were tested (n = 15). RESULTS No significant difference in fracture resistance was observed between any of the groups. CONCLUSIONS Under the conditions of this study, reinforcement of endodontically treated mature teeth by placement of adhesive materials in the root was not demonstrated.
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Abstract
Spinal (intrathecal) anesthesia has evolved into a safe, widely accepted method of anesthesia with many advantages. However, the past decade has seen a large number of case reports and incidence studies that implicate the local anesthetic (LA) lidocaine as being more neurotoxic than other commonly used LAs such as bupivacaine and tetracaine, based on patterns of clinical use current at the time of those reports. Available studies suggest a risk of persistent lumbosacral neuropathy after spinal lidocaine by single injection in about 1 in 1300 procedures and a risk as high as about 1 in 200 after continuous spinal anesthesia with lidocaine. While uncommon, this risk is probably an order of magnitude higher than the risk reported for other commonly used LAs or for general anesthesia. Spinal lidocaine is also implicated in the syndrome of transient neurologic symptoms (previously referred to as transient radicular irritation), manifest by pain or dysesthesia in the buttocks or legs after recovery from anesthesia. Although the pain typically resolves within 1 week without lasting sequelae, it can be severe in up to one third of patients with the syndrome. In addition to clinical studies, both whole animal and in vitro studies have shown that lidocaine can be neurotoxic at clinically available concentrations and that lidocaine is more neurotoxic than equipotent concentrations of other commonly used LAs. The mechanism of this neurotoxicity may involve changes in cytoplasmic calcium homeostasis and mitochondrial membrane potential.
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Häckel CG, Krueger S, Grote HJ, Oshiro Y, Hodges S, Johnston DA, Johnson ME, Roessner A, Ayala AG, Czerniak B. Overexpression of cathepsin B and urokinase plasminogen activator is associated with increased risk of recurrence and metastasis in patients with chondrosarcoma. Cancer 2000; 89:995-1003. [PMID: 10964329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
BACKGROUND Deregulation of the cellular protease network has been shown to be responsible for aggressive clinical behavior in several common human malignancies. In the current study, the authors evaluated the expression patterns of proteases in patients with chondrosarcoma of bone and correlated these patterns with clinical outcome. METHODS The expression levels of urokinase plasminogen activator; matrix metalloproteinase types-1, -2, and -9; and cathepsins B and L were determined immunohistochemically in 114 cases of chondrosarcomas of bone and were correlated with their clinicopathologic parameters as well as with long term follow-up data. RESULTS Overexpression of cathepsin B was associated with a high rate of local recurrence (P = 0.006) and a decreased recurrence free survival (P = 0.005). Overexpression of urokinase plasminogen activator was associated with an increased rate of metastasis (P = 0. 013), a decreased metastasis free survival (P = 0.016), and a decreased 5-year overall survival rate (P = 0.048). The univariate Cox model showed that tumor extension into soft tissue, high histologic grade, and overexpression of cathepsin B were predictors of adverse outcome. Multivariate analysis showed only overexpression of cathepsin B and tumor extension into soft tissue to be independent predictors of local recurrence. CONCLUSIONS Overexpression of cathepsin B and urokinase plasminogen activator can be used to identify those patients with chondrosarcoma of bone who have an increased risk of local recurrence and distant metastases.
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Chatziioannou AN, Johnson ME, Pneumaticos SG, Lawrence DD, Carrasco CH. Preoperative embolization of bone metastases from renal cell carcinoma. Eur Radiol 2000; 10:593-6. [PMID: 10795540 DOI: 10.1007/s003300050969] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The purpose of this study was to correlate the effectiveness of preoperative embolization with the blood loss and transfusion requirement during surgery for bone metastases from renal cell carcinoma. Twenty-eight preoperative embolizations in 26 patients with renal cell carcinoma metastatic to bone were retrospectively evaluated and divided into two groups: Group A included the embolizations that resulted in complete devascularization of the lesion as defined by the post-embolization arteriograms, and group B included those with an incomplete result. The two groups were compared with regard to blood loss and transfusion requirement during surgery, by unpaired two-tailed Student's t-test. Where complete embolization was effected (group A, 10 cases), there was a mean blood loss of 535 +/- 390 ml. When a less than complete embolization was achieved (group B, 18 cases), the mean blood loss was 1.247 +/- 1.047 ml (p = 0.049). The red blood cell transfusion in group A was 1.3 +/- 1 units, whereas in group B it was 2.4 +/- 1.2 (p = 0.03). Preoperative embolization of bone metastases from renal cell carcinoma with subsequent complete devascularization leads to significant reduction of blood loss during surgery. Interventional radiologists should pursue and embolize every feeder to the metastasis, because any less than complete devascularization increases the amount of blood loss and the amount of red blood cell transfusion during surgery.
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Park S, Wanna L, Johnson ME, Venton DL. A mass spectrometry screening method for antiaggregatory activity of proteins covalently modified by combinatorial library members: application to sickle hemoglobin. JOURNAL OF COMBINATORIAL CHEMISTRY 2000; 2:314-7. [PMID: 10891097 DOI: 10.1021/cc9900798] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A homogeneous assay, based on electrospray mass spectrometry, is described for identifying compounds in a combinatorial library that covalently modify a protein and thereby enhance its solubility. The technique is based on measuring the distribution of modified proteins in the supernatant versus aggregate. Compounds having the greatest anti-aggregatory activity are those with the highest supernatant/aggregate ratio. Mass is used as a marker to identify which covalent modifier in the library is involved. An exploratory study is presented which demonstrates that the antisickling activity of a family of isothiocyanates, as measured by the standard C(sat) assay, correlates well (r(2) = 0.98) with the mass spectrometry analysis of the supernatant/aggregate distribution. The technique has potential for screening libraries capable of covalently modifying other proteins of clinical interest, e.g., Alzheimer's, Huntington's, and various prion related diseases.
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Ostrowski ML, Johnson ME, Smith PD, Chevez-Barrios P, Spjut HJ. Low-grade intraosseous osteosarcoma with prominent lymphoid infiltrate. Arch Pathol Lab Med 2000; 124:868-71. [PMID: 10835523 DOI: 10.5858/2000-124-0868-lgiowp] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Low-grade intraosseous osteosarcoma is an uncommon and well-differentiated osteosarcoma with a good prognosis. We report a proximal tibial low-grade intraosseous osteosarcoma with a prominent intratumoral lymphoid infiltrate, which led to an initial diagnosis of probable malignant lymphoma. The importance of this infiltrate, which exhibited reactive features on flow cytometric studies, is not known. Our patient is free of tumor 1 year after limb salvage surgery, without hematologic or lymphoid abnormalities.
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Gallaher DL, Johnson ME. Nonaqueous capillary electrophoresis of fatty acids derivatized with a near-infrared fluorophore. Anal Chem 2000; 72:2080-6. [PMID: 10815969 DOI: 10.1021/ac9909251] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Saturated linear fatty acids, derivatized with a near-infrared absorbing fluorescent dye, were separated in 100% methanol with 12.5 mM tetraethylammonium chloride added as a charge carrier. Separation at 380 V/cm was acceptable for acids that differed in length by a single carbon. The labeled linear fatty acids behaved as random coils in the nonaqueous separation medium, as shown in a fit to a simple theoretical expression. However, even in 100% methanol with a trimethylsilylated capillary, significant adsorption to the capillary wall occurred, which reduced resolution and slowed the separation. Addition of water to the methanol medium caused significant differences in separation behavior of high molecular weight acids (>C16). Addition of a cetyltrimethylammonium bromide surfactant to the separation medium dynamically coated the capillary and greatly improved the separation. The surfactant also interacted with the acyl tail, apparently causing it to collapse. Resolution in an optimal separation medium (20 mM surfactant) ranged from 1.6 to 1.1, depending on chain length, and theoretical plate heights were under 4 microm (N > 10(5)). Resolution was more than adequate to separate stearic (C18:0) from oleic (C18:1) acid, as well as other unsaturated C18 homologues.
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Johnson ME. Perineural concentration of lidocaine is more relevant to spinal neurotoxicity than the concentration administered. Anesth Analg 2000; 90:766-7. [PMID: 10702475 DOI: 10.1097/00000539-200003000-00052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Gee AJ, Groen LA, Johnson ME. Ion trap mass spectrometry of trimethylsilylamides following gas chromatography. JOURNAL OF MASS SPECTROMETRY : JMS 2000; 35:305-310. [PMID: 10767758 DOI: 10.1002/(sici)1096-9888(200003)35:3<305::aid-jms917>3.0.co;2-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Fatty acid amides are a class of compounds with newly discovered biological activity. The ion trap mass spectrometric characteristics of silylated fatty acid amides were examined. Silylation of primary fatty acid amides is required prior to gas chromatography owing to thermal instability of the underivatized compound. The trimethylsilylated amides do not yield a molecular ion under normal electron ionization conditions (70 eV). With methane as a chemical ionization gas, the [M+H]+ ion appears. The [M+H]+ ion also appears when the helium buffer gas pressure is increased in the ion trap. There are three fragments other than the [M+H]+ peak that are predominant in the ion trap mass spectra of these compounds. Two of the fragments have been reported previously, namely the m/z 59 and the [M-71]+ fragments. The fragment of m/z 72 was identified and is the result of a rearrangement. Isotopic labeling was used to confirm fragment identity and the composition of the rearrangement products. Fragmentation patterns were affected by the amide chain length and concentration.
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Johnson ME. Electronic current awareness for mental health facilities. BULLETIN OF THE MEDICAL LIBRARY ASSOCIATION 2000; 88:77-80. [PMID: 10658969 PMCID: PMC35203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
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