Publications by authors named "Steidley K"

Recently, the decarboxylation of oleic acid (9()-octadecenoic acid) catalyzed by triruthenium dodecacarbonyl, Ru(CO), to give a mixture of heptadecenes with concomitant formation of other hydrocarbons, heptadecane and C17 alkylbenzenes, was reported. The product mixture, consisting of about 77% heptadecene isomers, 18% heptadecane, and slightly >4% C17 alkylbenzenes, possesses acceptable diesel fuel properties. This reaction is now applied to other fatty acids of varying chain length and degree of saturation as well as double-bond configuration and position.

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Used cooking or frying oils are of increasing interest as inexpensive feedstock for biodiesel production. In this work, used frying oils obtained from 16 local restaurants were investigated regarding their fatty acid profile vs. the fatty acid profile of the oil or fat prior to use.

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The composition and structures of triacylglycerols (TAG) in a commercially prepared hydrogenated soybean oil margarine basestock [iodine value (IV) 65, 39.7% trans fatty acids] were determined by high-performance liquid chromatography (HPLC) in tandem with atmospheric pressure chemical ionization (APCI) mass spectrometry (MS). The basestock was separated by preparative HPLC into four fractions.

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Purpose: Carbamazepine is one of several antiepileptic drugs (AEDs) that release the inhibitory neurotransmitter serotonin as part of their pharmacodynamic action on brain neurons. We undertook this study to investigate the cellular processes by which carbamazepine (CBZ) releases serotonin from brain tissue.

Methods: Tissue slices were prepared from hippocampi of Sprague-Dawley rats.

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An important quality assurance (QA) procedure in high dose rate (HDR) remote afterloading brachytherapy is the verification of the system's control of the source by a direct test with dosimetry medium prior to the patient's first treatment. In this test radiochromic film is placed in direct contact with the applicator and the patient's proposed treatment is then run with their EPROM card. Examination of the film allows a quick appraisal of step size, number of steps, and offset.

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Effective doses for patients undergoing chest radiography were computed utilizing updated weighting factors, published organ doses and measured entrance doses. The effective dose decreases with beam energy (kVp) and reaches a minimum value after 100 kVp, with values when a grid is used (6.90 microSv) being 145% higher at this energy than when no grid is used (2.

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Mesothelial cells in vitro exhibited binding sites for L-quinuclidinyl[phenyl-4-3H]-benzilate ([3H]-QNB), but not [3H]-N-methylscopolamine (NMS), a cell-impermeable ligand. [3H]-QNB binding demonstrated a biphasic pattern of binding in living cells: a maximum after 15 min at 37 degrees C was followed by a decrease out to 90 min. [3H]-QNB binding was blocked by increasing concentrations of atropine; WIN35428 and GBR12909, dopamine transport inhibitors also decreased binding.

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A Clarkson's sector integration scheme has been implemented on a personal computer to calculate mean scatter-air ratio (SAR) and mean tissue-air ratio (TAR) for external photon beams of irregular shape. To find where a given radial line from the point of interest intersects the edge of the radiation field, polygon clipping algorithms have been adapted from the field of image processing. The program has calculation run times of approximately 1 s on an 80387 with a math coprocessor for an integration of 36 sectors.

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A beam stop technique was used to measure the densitometric scatter fractions under three regions of a humanoid chest phantom utilizing LaOBr and Gd2O2S screens. For these receptors, the scatter fractions under the lung and retrocardiac areas were 13%-36% lower than published values for CaWO4. In the mediastinal area, there was no significant difference between the CaWO4 and rare-earth phosphors.

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Objective: To determine the effect of extracellular choline concentration on phospholipid production and handling by peritoneal mesothelial cells in vitro.

Design And Measurements: Radiolabeled choline was used to monitor the formation of phosphatidylcholine (PC), sphingomyelin (SPH), and lysophosphatidylcholine (LPC) by rat and rabbit mesothelial cells as a function of concentration and time of exposure to choline. The subcellular location of the newly formed phospholipids was examined by ultracentrifugation in Percoll-sucrose gradients using analytical cell fractionation techniques.

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Preliminary evidence of muscarinic acetylcholine receptors (AchRs) in rabbit and human peritoneal mesothelial cells grown in tissue culture is reported. Atropine displaceable binding of L-quinuclidinyl[phenyl-4-3H]-benzilate (QNB), an antagonist that binds to all AchR subtypes, and [N-methyl-3H]-4-diphenylacetoxy-N-methyl-piperidine methiodide (4-DAMP), an antagonist specific for AchR subtypes 1 and 3, to homogenates of mesothelial cells was approximately 400 and 120 fmol ligand bound/milligram cell protein, respectively. A similar value for specific [3H]-QNB binding was observed in living cells exposed to ligand and atropine for 1 hour at 37C.

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The average free choline level was determined to be 14 mumol/L in peritoneal dialysates and 22 mumol/L in the plasma of 30 patients on continuous ambulatory peritoneal dialysis (CAPD). Daily choline loss via dialysate averaged 129 mumol with 32 mumol choline lost per dwell. Daily choline loss via the dialysate was positively correlated with plasma choline concentrations.

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Previous reports describe a characteristic, rapidly progressive, periodontitis that is unique to patients who are seropositive for HIV antibody (Western blot +). The purpose of this study was to compare the T4 and T8 lymphocyte subpopulations in the peripheral blood and periodontal lesions of these HIV patients with those of healthy controls. T-cell subsets in peripheral blood were quantified by flow cytometry.

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Primary radiotherapy for 127 early breast cancers produced five-year local control of 96.1 percent and NED results of 81.1 percent.

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This study developed the mathematics of a rotating point source. The relative dose and the dose rate were numerically evaluated at various positions along the cardinal axes, both with and without a 1-m-thick concrete barrier. The point source model was compared to experimental data gathered at an operational megavoltage radiation therapy facility.

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The average free choline level was determined to be 14 M in peritoneal dialysates and 22 M in plasma of thirty patients on continuous ambulatory peritoneal dialysis (CAPD). Daily choline loss via dialysate averaged 129 moles with 32 moles choline lost per dwell. Daily choline loss via the dialysate was positively correlated with plasma choline concentrations.

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A survey of lectin-binding specificities present on rodent and human mesothelial cells propagated and maintained in tissue culture was made using fluorescein isothiocynate conjugated (FITC) lectins. Rodent and human cells exhibited cell-associated fluorescence following exposure to the FITC-lectins from C. ensiformis, T.

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Carbohydrates present on the surface of cells have been implicated in such processes as bacterial adherence, surfactant secretion and reutilization, and cell-cell recognition. In this study, fluorescein isothiocyanate (FITC) conjugated lectins were used to probe for such carbohydrates on the surface and interior regions of rabbit peritoneal mesothelial cells propagated in vitro. A cell permeabilization technique employing treatment with formalin and saponin provided the greatest presentation of surface membrane structure and lectin binding.

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The nature of intracytoplasmic lipid inclusions found in cultured rabbit and rat peritoneal mesothelial cells was examined by ultrastructural and biochemical techniques. Transmission electron microscopy also demonstrated extracellular release of these lipid bodies. Differential fixation with tannic acid revealed 2 types of inclusions, lamellated (lamellar bodies) and nonlamellated (homogeneous).

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Both the design considerations and the dosimetric properties of the Siemens Model 5800 linear accelerator are discussed. This unit is of such an energy (3.3 MV) as to imitate Cobalt-60 teletherapy depth doses.

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Renal cystic epithelia and peritoneal mesothelia from two humans with autosomal recessive polycystic kidney disease (ARPKD) were grown in culture. Cystic epithelial and mesothelial cells formed continuous monolayers in vitro. By electron microscopy, cystic renal cells exhibited a single apical cilium and numerous short, stubby microvilli, both in situ and in vitro.

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The radiation phosphene.

Vision Res

October 1990

A low flux of X-rays below the Cerenkov energy threshold generates a phosphene by direct action on the retina without a fluorescence in the ocular media. X-rays above the Cerenkov threshold can generate only a faint luminescence in the lens and cornea. From experimental work on humans in 1905 with unencapsulated radium, it is known that approximately 80% of the intensity of the radium phosphene is from the beta-ray component and approximately 20% from the gamma-ray.

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Ten cancer patients whose eyes were therapeutically irradiated with 6-18 MeV electrons reported visual light sensations. Nine reported seeing blue light and one reported seeing white light. Controls reported seeing no light.

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Immunochemical methods that are used to assess von Willebrand factor in human beings and dogs were used to assess von Willebrand factor in 3 cat species. Our findings indicated that the expression and multimeric composition of von Willebrand factor in plasma and platelets of cats were similar to those reported in human beings and dogs. We suggest that these methods may be used to evaluate von Willebrand disease in members of the cat family used in this study.

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