176
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Mangum FI, Jeske AH, Chan JT, Powers JM. Effect of fluoride iontophoresis on dentinal bonding. GENERAL DENTISTRY 1993; 41:139-142. [PMID: 8330729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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177
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Sparaco M, Bonilla E, DiMauro S, Powers JM. Neuropathology of mitochondrial encephalomyopathies due to mitochondrial DNA defects. J Neuropathol Exp Neurol 1993; 52:1-10. [PMID: 8426185 DOI: 10.1097/00005072-199301000-00001] [Citation(s) in RCA: 97] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
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178
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Powers JM. No longer destined to eat their young: satisfaction among Army family practice faculty. Mil Med 1993; 158:32-7. [PMID: 8437738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
In January 1987, all 63 faculty members at Army Family Practice Residencies received satisfaction questionnaires. Fifty-nine faculty (93.8%) responded with 40 (67.8%) being satisfied and 19 (32.2%) dissatisfied. Compared to faculty 7 years prior, these faculty are slightly older, have more practice experience, more opportunities for fellowship training, and are less likely both to have remaining mandatory military obligation and to leave the Army after 3 years. The key areas of faculty development, control over professional life, administration, and departmental goals and objectives truly discriminated satisfaction from dissatisfaction. A strategy to systematically develop potential faculty and reduce dissatisfaction is proposed.
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179
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Powers JM, Liu Y, Moser AB, Moser HW. The Inflammatory Myelinopathy of Adreno-Leukodystrophy. J Neuropathol Exp Neurol 1992; 51:630-43. [PMID: 1362438 DOI: 10.1097/00005072-199211000-00007] [Citation(s) in RCA: 173] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Prominent inflammation in the demyelinative lesion of adreno-leukodystrophy (ALD) has suggested an immune-mediated pathogenetic component. Commercially available antibodies to T cells, B cells, macrophages, class I and II molecules, complement, IgG, IgM, IgA, interleukin-1 (IL-1), intercellular adhesion molecule-1 (ICAM-1) and tumor necrosis factor-alpha (TNF) were applied to paraffin sections of formaldehyde-fixed postmortem samples. Twenty-five primary demyelinative lesions from five juvenile ALD, three adult ALD, and three adrenomyeloneuropathic patients were evaluated with appropriate positive and negative controls. Macrophages and astrocytes were the predominant cells detected at the active edge; T lymphocytes, including T4 and CD45R subsets, were nearly as numerous but usually located around vessels within the lesion. B cells and plasma cells, usually containing IgG, were uncommon. The expression of class II molecules, restricted to one adult, was problematic; class I expression was increased in microvascular and other cells. Degraded myelin was labeled with antibodies to C3d and IL-1; IL-1 and ICAM-1 immunoreactivity was seen on microvessels and astrocytes. Tumor necrosis factor-alpha immunoreactivity was detected in macrophages, but more prominently in astrocytes. These data support a natural immune response in the demyelinative lesion of ALD, consisting predominantly of reactive astrocytes, macrophages, T cells and cytokines. A two-stage pathogenetic theory is discussed. The postulated roles of TNF and reactive astrocytes, in concert with a fundamental myelinolytic biochemical defect, suggest a different pathogenetic mechanism and raise novel therapeutic possibilities.
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180
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Hair LS, Symmans F, Powers JM, Carmel P. Immunohistochemistry and proliferative activity in Lhermitte-Duclos disease. Acta Neuropathol 1992; 84:570-3. [PMID: 1462769 DOI: 10.1007/bf00304477] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We have evaluated a recurrence of Lhermitte-Duclos disease by immunohistochemistry for Purkinje cell markers and proliferative activity (proliferating cell nuclear antigen), by electron microscopy and for DNA ploidy (image analysis). While most of the abnormal neurons in the lesion appear to be derived from granule cells, several Purkinje cell specific polyclonal and monoclonal antibodies, including L7, PEP 19 and calbindin, labeled a minor subpopulation. Staining with monoclonal antibodies to proliferating cell nuclear antigen and measuring cell DNA index and ploidy with a cell image analyzer revealed no proliferative activity. Electron microscopy findings were similar to those previously reported. In spite of its recurrence, our findings support the notion that Lhermitte-Duclos disease is malformative, not neoplastic, and that the characteristic neurons are derived predominantly but not exclusively from a non-Purkinje cell source, probably the granule cell.
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181
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Hoffman PM, Cimino EF, Robbins DS, Broadwell RD, Powers JM, Ruscetti SK. Cellular tropism and localization in the rodent nervous system of a neuropathogenic variant of Friend murine leukemia virus. J Transl Med 1992; 67:314-21. [PMID: 1405490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND We studied PVC-211 murine leukemia virus (MuLV) (1), a neuropathogenic variant of Friend MuLV, to determine its cellular tropism and distribution in the nervous system of infected rats and the factors that affected disease expression. EXPERIMENTAL DESIGN Rats from five different strains and mice from 3 strains were inoculated intracerebrally or intraperitoneally from birth to 10 days of age and observed for signs of neurologic disease and tumors for 24 weeks. Nervous system pathology, MuLV gp70 expression, and virus production were evaluated weekly for 4 weeks after perinatal infection of Fisher (F344) rats. Blood-brain-barrier integrity and ultrastructure were evaluated in 21-day-old symptomatic infected rats. Microvessel and mixed glial cell cultures were prepared from brains of infected and uninfected 21-day-old F344 rats and evaluated for virus production, MuLV gp70 expression, and the presence of PVC-211 MuLV DNA. RESULTS Tremor, ataxia, spasticity, and hindlimb weakness occurred in rats and mice as early as 3 weeks after neonatal infection. Severity, latency, and progression varied among mouse and rat strains but exposure to PVC-211 MuLV before 6 days of age was required for disease expression. Rapid PVC-211 MuLV replication in brain capillary endothelial cells (BCEC) early in the perinatal period was followed by widespread astrogliosis, neuropil vacuolation, and finally, neuronal degeneration in the spinal cord, brainstem, cerebellum, and subcortex. MuLV gp70 expression in vivo increased during infection, was restricted to BCEC, but was not associated with perivascular inflammatory infiltrates. BCEC cultured from microvessel preparations but not astrocytes or microglia in mixed glial cell cultures isolated from infected rats contained PVC-211 MuLV DNA, expressed MuLV gp70, and produced infectious virus. CONCLUSIONS The rapid replication of PVC-211 MuLV that occurs in the nervous system of infected rodents is restricted to BCEC. These infected BCEC appear to play a critical role in initiating the astroglial response in this neurodegenerative process through mechanisms that remain to be defined.
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MESH Headings
- Animals
- Blood-Brain Barrier
- Cells, Cultured
- DNA, Viral/analysis
- DNA, Viral/genetics
- Endothelium, Vascular/cytology
- Endothelium, Vascular/physiology
- Friend murine leukemia virus/genetics
- Friend murine leukemia virus/isolation & purification
- Genetic Variation/genetics
- Leukemia, Experimental/pathology
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C3H
- Nervous System/microbiology
- Nervous System/pathology
- Nervous System/ultrastructure
- Neuroglia/microbiology
- Neuroglia/pathology
- Neuroglia/ultrastructure
- Rats
- Rats, Inbred F344
- Rats, Inbred Lew
- Rats, Inbred WF
- Rats, Sprague-Dawley
- Virus Replication
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Abstract
PURPOSE The in vivo wear resistance of 12 composite resins were compared with an amalgam control using the Latin Square experimental design. Sixteen edentulous patients wearing specially designed complete dentures formed the experimental population. MATERIALS AND METHODS The Michigan Computer Graphics Measurement System was used to digitize the surface of the control and composite resin samples before and after 3-month test periods to obtain wear data. The 12 composite resins selected for this investigation based on their published composite classification types were seven fine particle composites, three blends, and two microfilled composite resins. The Latin Square experimental design was found to be valid with the factor of material being statistically different at the 5% level of significance. Wear was computed as volume loss (mm3/mm2), and all of the composites studied had more wear than the amalgam control (P = .001). RESULTS After 3 months, the mean (error) of wear of the amalgam was 0.028 (0.006). Means (error) of wear for the 12 composites were ranked from most to least wear by mean wear volume loss. CONCLUSION The absence of any relationship between mean wear volume loss and the volume percentage filler was confirmed by the correlation coefficient r = -0.158.
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183
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Theda C, Moser AB, Powers JM, Moser HW. Phospholipids in X-linked adrenoleukodystrophy white matter: fatty acid abnormalities before the onset of demyelination. J Neurol Sci 1992; 110:195-204. [PMID: 1506859 DOI: 10.1016/0022-510x(92)90028-j] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Changes in fatty acid composition of complex lipids were analyzed in postmortem white matter from a patient with late onset adrenoleukodystrophy (ALD). The specimen showed three regions with progressive myelin breakdown: morphologically normal white matter; areas with active demyelination and perivascular lymphocyte and macrophage infiltration; and areas with marked gliosis. In the morphologically intact region, cholesterol esters were similar in amount and fatty acid composition to those in control tissue, although marked changes were observed in the actively demyelinating area. Galactolipids in these areas were also similar to those in controls. In contrast, glycerophospholipids were increased in amount and in very long chain fatty acids (VLCFA), which are the hallmark of ALD, at the active edge of the demyelinative lesion and even in the apparently intact sample. Further fractionation of the glycerophospholipids by high performance liquid chromatography showed a significant (up to 39-fold) accumulation of hexacosanoic acid (C26:0) in phosphatidylcholine, but not in other phosphatidyl derivatives. The consistent increases in phosphatidylcholine VLCFA in all samples from the ALD brain, which are postulated to represent progressive stages in the development of the disorder, suggest that phosphatidylcholine may be involved in antigen formation and may underlie an immunological basis for the pathogenesis of ALD.
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184
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Smith LT, Powers JM, Ladd D. Mechanical properties of new denture resins polymerized by visible light, heat, and microwave energy. INT J PROSTHODONT 1992; 5:315-20. [PMID: 1520453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Properties of seven newer resins polymerized using a water bath, microwave energy, or by visible light were measured. Generally, the new resins were harder and less flexible but had lower impact strength than did the heat-polymerized, rubber-modified resin (Lucitone). The light-activated urethane dimethacrylate resin (Triad) was the least flexible. Microwave polymerization improved the modulus of elasticity of two resins, decreased the impact strength of one, and had little effect on the properties of two other resins.
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185
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O'Keefe KL, Powers JM, McGuckin RS, Pierpont HP. In vitro bond strength of silica-coated metal posts in roots of teeth. INT J PROSTHODONT 1992; 5:373-6. [PMID: 1520460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
This study determined the in-vitro bond strength of abrasive-sprayed and silica-coated Ni-Cr-Be posts to roots of extracted teeth using three resin cements (Panavia EX [P], Super-Bond C&B [SB], Prisma Universal Bond 2-Dicor [PUB-D]) and zinc phosphate cement (ZP). There were no significant differences among bond strengths of resin cements (8.8 to 10.8 MPa) bonded to abrasive-sprayed posts, but the bonds were stronger than those obtained using zinc phosphate cement (4.4 MPa). With the silica-coated posts, Super-Bond C&B produced the highest bond strength (14.5 MPa), followed by PUB-D (10.9 MPa), P (7.5 MPa), and ZP (5.4 MPa).
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186
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Hair LS, Nuovo G, Powers JM, Sisti MB, Britton CB, Miller JR. Progressive multifocal leukoencephalopathy in patients with human immunodeficiency virus. Hum Pathol 1992; 23:663-7. [PMID: 1592389 DOI: 10.1016/0046-8177(92)90322-t] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Lesions of progressive multifocal leukoencephalopathy (PML) in patients infected with the human immunodeficiency virus (HIV) often have mononuclear cell infiltrates so intense that they obscure the nature of the lesion. This response may be especially prominent in stereotactic biopsies of contrast-enhancing areas. Of 10 consecutive PML lesions biopsied stereotactically, three were markedly, two were moderately, and five were mildly inflamed. There were few to no enlarged oligodendrocytic nuclei with inclusions in the markedly and moderately inflamed lesions. We investigated all biopsies with immunoperoxidase, DNA in situ hybridization, polymerase chain reaction, and Southern immunoblot methodologies for toxoplasmosis and the following viruses: JC, cytomegalovirus, herpes simplex viruses I and II, and human T-cell lymphotropic viruses I, II, and III. We confirmed the presence of JC virus in each lesion; polymerase chain reaction revealed HIV genome only in one. Inflammatory PML lesions in HIV+ patients do not reflect co-infection with toxoplasmosis or viruses commonly seen in these patients. The mononuclear cells are primarily T lymphocytes. Patients with severely inflamed PML lesions, whether HIV+ or not, often show stabilization of symptoms with or without antiviral treatment and have longer lengths of survival than patients with less inflamed lesions.
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187
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Smith LT, Powers JM. Relative fit of new denture resins polymerized by heat, light and microwave energy. AMERICAN JOURNAL OF DENTISTRY 1992; 5:140-2. [PMID: 1388951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
This study compared in vitro the relative fit of seven denture resins polymerized by different methods to their gypsum casts. Relative fit in the molar-to-molar region of the resin bases on their stone casts was evaluated independently by five evaluators at three times (after processing, after polishing and after storage in water) and ranked using non-parametric statistics. The denture resins polymerized by microwave energy, (Acron MC), low heat, (Perform, 45 degrees C), and visible light, (Triad) fit better after polishing and after storage in water than those resins polymerized at higher temperatures (Lucitone 199, 74 degrees C and Accelar 20, Compak and Permacryl 20, 100 degrees C). The traditional heat-polymerized resin (Lucitone) had an average fit after storage in water.
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188
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Schneider W, Powers JM, Pierpont HP. Bond strength of composites to etched and silica-coated porcelain fusing alloys. Dent Mater 1992; 8:211-5. [PMID: 1325930 DOI: 10.1016/0109-5641(92)90086-r] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
In vitro bond strengths of two composite veneering materials to two porcelain fusing alloys were measured utilizing two storage conditions. The alloys were etched or treated with silica applied by blasted, thermal or pyrogenic techniques and then silanated. Bond strengths were higher for the Ni-Cr-Be than the Au-Pd alloy with most values greater than 18 MPa. Bond strengths to etched and silanated Au-Pd alloy were low (less than 6.5 MPa), whereas samples treated with silica and silanated had significantly higher values. Bond strengths to the Ni-Cr-Be alloy were highest with the thermal and pyrogenic silica treatments. After thermocycling, most bond strengths to the Au-Pd alloy decreased, but were the same or higher to the Ni-Cr-Be alloy. Cohesive failures of the opaquers were observed.
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189
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Wolf DM, Powers JM, O'Keefe KL. Bond strength of composite to porcelain treated with new porcelain repair agents. Dent Mater 1992; 8:158-61. [PMID: 1521702 DOI: 10.1016/0109-5641(92)90074-m] [Citation(s) in RCA: 82] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
In vitro tensile bond strengths of composite to porcelain were evaluated using three pretreatments (HF etching, sandblasting, diamond abrasion) of the porcelain, four bonding agents (Clearfil Porcelain Bond, Porcelain Liner M, Porcelain Liner M with Super-Bond C&B, and Scotchprime) and two storage conditions (24 h and thermocycling). The overall coefficient of variation was 27%. Significant differences among bond strengths were observed, with storage condition being the most important factor, followed by bonding agent and then pretreatment. Thermocycling decreased the bond strength of all samples, but samples treated with Scotchprime were affected least. For 24 h storage, Clearfil Porcelain Bond and Scotchprime had bond strengths above 23 MN/m2 to sandblasted porcelain.
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190
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Powers JM, Liu Y, Hair LS, Kascsack RJ, Lewis LD, Levy LA. Concomitant Creutzfeldt-Jakob and Alzheimer diseases. Acta Neuropathol 1991; 83:95-8. [PMID: 1792870 DOI: 10.1007/bf00294437] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We report a 69-year-old female with cerebral and cerebellar symptomatology of 15-month duration. At autopsy, both panencephalopathic Creutzfeldt-Jakob and plaque-predominant Alzheimer diseases were found. Plaque amyloid was exclusively of the beta/A4 type, but abundant abnormal protease-resistant protein was identified by Western blot analysis of brain extracts.
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191
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Powers JM, Wander A, Rous PJ, Somorjai GA. Structural analysis of the beta -SiC(100)-c(2 x 2) surface reconstruction by automated tensor low-energy electron diffraction. PHYSICAL REVIEW. B, CONDENSED MATTER 1991; 44:11159-11166. [PMID: 9999236 DOI: 10.1103/physrevb.44.11159] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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192
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Eidelberg D, Dhawan V, Moeller JR, Sidtis JJ, Ginos JZ, Strother SC, Cederbaum J, Greene P, Fahn S, Powers JM. The metabolic landscape of cortico-basal ganglionic degeneration: regional asymmetries studied with positron emission tomography. J Neurol Neurosurg Psychiatry 1991; 54:856-62. [PMID: 1744638 PMCID: PMC1014567 DOI: 10.1136/jnnp.54.10.856] [Citation(s) in RCA: 118] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Regional metabolic rate for glucose (rCMRGlc) was estimated using [18F]fluorodeoxyglucose (FDG) and positron emission tomography (PET) in five patients (four men, one woman; mean age 68; mean disease duration 2.4 years) with clinical findings consistent with the syndrome of cortico-basal ganglionic degeneration (CBGD). Left-right rCMRGlc asymmetry, (L-R)/(L + R) x 100, was calculated for 13 grey matter regions and compared with regional metabolic data from 18 normal volunteers and nine patients with asymmetrical Parkinson's disease (PD). In the CBGD group mean metabolic asymmetry values in the thalamus, inferior parietal lobule and hippocampus were greater than those measured in normal control subjects and patients with asymmetrical PD (p less than 0.02). Parietal lobe asymmetry of 5% or more was evident in all CBGD patients, whereas in PD patients and normal controls, all regional asymmetry measures were less than 5% in absolute value. Measures of frontal, parietal and hemispheric metabolic asymmetry were found to be positively correlated with asymmetries in thalamic rCMRGlc (p less than 0.05). The presence of cortico-thalamic metabolic asymmetry is consistent with the focal neuropathological changes reported in CBGD brains. Our findings suggest that metabolic asymmetries detected with FDG/PET may support a diagnosis of CBGD in life.
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193
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Smith LT, Powers JM. In vitro properties of light-polymerized reline materials. INT J PROSTHODONT 1991; 4:445-8. [PMID: 1811639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
One premixed and three powder-liquid light-polymerized, hard denture reline materials were evaluated for Knoop hardness, transverse strength, and tensile strength when bonded to a heat-activated denture resin. The chemical compositions of the components of the reline materials were analyzed. The premixed light-activated liner was harder, had a higher tensile bond strength to the heat-activated denture resin, and was somewhat stronger than the power-liquid reline materials. Properties of the resins were related to their compositions.
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194
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Fetell MR, Bruce JN, Burke AM, Cross DT, Torres RA, Powers JM, Stein BM. Non-neoplastic pineal cysts. Neurology 1991; 41:1034-40. [PMID: 2067630 DOI: 10.1212/wnl.41.7.1034] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
We identified 53 patients with non-neoplastic cysts of the pineal gland. In contrast to patients with pineal neoplasms, pineal cysts are usually asymptomatic. They infrequently obstruct the aqueduct to cause hydrocephalus or compress the tectum to produce the neuro-ophthalmologic signs of dorsal midbrain dysfunction. Obstructive hydrocephalus was present in only five patients (9.4%); three of them showed clinical signs of Parinaud's syndrome. CT and MRI typically reveal a cystic mass that averages 1.6 cm in anteroposterior (A-P) diameter with calcification at the periphery and faint rim-like contrast enhancement. Sagittal MRI is the most useful diagnostic test because it shows the anatomic relationship of the cyst to the aqueduct. The mass may compress the tectum and distort the proximal aqueduct; occasionally a large cyst may occlude the aqueduct. All patients with obstructive hydrocephalus had cysts greater than 2.0 cm in A-P diameter. Nine patients had suboccipital craniotomy. In all of them, the cysts contained clear fluid and were easily removed. We advocate conservative management with clinical observation of these benign lesions that may be developmental variants of normal pineal gland.
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195
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Roeder LB, DeSchepper EJ, Powers JM. In vitro bond strength of repaired amalgam with adhesive bonding systems. JOURNAL OF ESTHETIC DENTISTRY 1991; 3:126-32. [PMID: 1817580 DOI: 10.1111/j.1708-8240.1991.tb00983.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The in vitro tensile bond strengths of Amalgambond and All-Bond were evaluated as adhesive systems for the repair of amalgam (Valiant Ph.D.) by two repair amalgams (Valiant or Valiant Ph.D.). Other variables evaluated were two surface finishes (SiC finish and sandblasted) and two storage conditions (37 degrees C, 24 h, and thermocycled). The Amalgambond bond was not reliable. All-Bond bonded amalgam to amalgam with Liner-FX. Bond strengths ranged from 3.4 to 8.8 MPa. The highest bond strengths were achieved with a sandblasted surface repaired with Valiant. Thermocycling did not affect bond strength.
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196
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DeSchepper EJ, Cailleteau JG, Roeder L, Powers JM. In vitro tensile bond strengths of amalgam to treated dentin. JOURNAL OF ESTHETIC DENTISTRY 1991; 3:117-20. [PMID: 1817578 DOI: 10.1111/j.1708-8240.1991.tb00981.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Since amalgam traditionally relies on undercuts in the tooth preparation for retention, extensive tooth structure must be removed for amalgam core build-ups. In contrast, the ideal build-up material would achieve its retention by directly bonding to tooth structure. This study compared tensile bond strengths of amalgam to dentin using All-Bond Liner-FX with three different dentin pretreatment conditions and Amalgambond according to the manufacturer's directions. One hundred and twenty dentin samples were tested. Groups 1-3 used All-Bond Liner-FX as a bonding agent. Group 1 received a 15-second application of 10 percent phosphoric acid on the dentin; Group 2 received the recommended dentin conditioner; and Group 3 received no dentin pretreatment. Group 4 used Amalgambond as the bonding agent after a 10-second application of 10 percent citric acid/3 percent ferric chloride. Analysis of the data was conducted using both ANOVA and the Weibull statistic. Results of the analysis of variance indicate that there were no statistical differences among mean tensile bond strengths for the three dentin pretreatment conditions using All-Bond. All (30) of the Amalgambond specimens debonded prior to testing. The All-Bond fracture data was well described by the Weibull function as evidenced by the high coefficient of determination (R2 = 0.98-0.99). Fracture analysis indicated that all of the Amalgambond failures were adhesive at the Amalgambond-amalgam interface. All-Bond fractures were mixed cohesive/adhesive failures indicating similar bonding to amalgam and dentin.
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197
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Hair LS, Rogers JD, Chadburn A, Sisti MB, Knowles DM, Powers JM. Intracerebral Hodgkin's disease in a human immunodeficiency virus-seropositive patient. Cancer 1991; 67:2931-4. [PMID: 2025859 DOI: 10.1002/1097-0142(19910601)67:11<2931::aid-cncr2820671137>3.0.co;2-e] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Intracerebral involvement of Hodgkin's disease (HD) is rarely described, with only 42 cases in the literature. Since the outbreak of the acquired immune deficiency syndrome (AIDS) epidemic, there has been an increasing number of human immunodeficiency virus (HIV)-infected (HIV+) persons who have diffuse non-Hodgkin's lymphoma and, more recently, atypical aggressive HD. The authors report the case of a patient with a history of intravenous drug abuse (IVDA) and Stage IVB HD who, after a drug-induced clinical remission, had intracerebral mixed-cellularity HD. This appears to be the first report of intracerebral HD in a person who is HIV+.
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198
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Gunn S, Powers JM. Strength of ceramic brackets in shear and torsion tests. JOURNAL OF CLINICAL ORTHODONTICS : JCO 1991; 25:355-8. [PMID: 1939633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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199
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Abstract
The successful repair of a composite restoration may depend on the ability of a repair composite to spread on the restoration to be repaired. The purpose of this study was to measure the spreading of four oligomers on their polymers. The oligomers were: ethoxylated bisphenol A dimethacrylate (EB), BisGMA/3EDMA:70/30 (ED), BisGMA-Nupol (NU), and urethane dimethacrylate (UD). Polymer strips were made from these oligomers by light-curing. Spreading was calculated from measurements of the contact angle of the oligomers on the polymers, the surface tension of the oligomers, and the viscosity of the oligomers. In this model system, values of spreading of EB, ED, UD, and NU on oligomer ED were: 2.8, 1.4, 0.24, and 0.0009 cm/s, respectively. The spreading by oligomers EB, ED, and UD on polymer ED was slightly higher than that on polymer UD.
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200
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Robinson RM, Powers JM, Cleveland PH, Thyer BA. Inpatient treatment for depressed children and adolescents: preliminary evaluations. THE PSYCHIATRIC HOSPITAL 1991; 21:107-12. [PMID: 10112796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Reported are the results of two uncontrolled outcome studies that evaluate the effectiveness of inpatient psychiatric treatment of children and adolescents suffering from clinical depression. Study 1 employed a sample of 7 children and measured outcome with the Depression Self-rating Scale (DSRS), the Hopelessness Scale for Children (HSC), and the Global Asssessment of Functioning (GAF) scale, which were administered to each child upon admission and again at discharge. Inpatient treatment involved multiple interventions, including individual psychotherapy, medication, milieu therapy and token economy, and other procedures. At discharge, statistically significant improvements were found on the patients' GAF and HSC scores, but not on their DSRS scores. Study 2 used a sample of 15 adolescents, also admitted for clinical depression. Administered at each patient's admission and discharge, the Beck Depression Inventory (BDI), Generalized Contentment Scale (GCS), and Index of Self-esteem (ISE) were used to measure outcome. The multi-modal treatment program offered to the sample in Study 2 was similar to that offered the sample in Study 1. At discharge all three outcome measures reflected statistically significant improvements in the patients studies; therefore, these results provide addmtional support for the inpatient treatment of depressed children and adolescents.
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