Publications by authors named "Chloee H Armour"

Three heat-resistant mutant cell lines (78-1, 78-2, 78-3) were previously selected from Chinese hamster ovary cells. In this study, we investigated whether the differences in intrinsic thermal sensitivity result from alteration of stress protein levels or cellular structural changes. Although there was no significant difference in the levels of stress proteins, i.

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The development of a brachytherapy technique that will use a scanning source to simulate continuous low dose rate irradiation holds the possibility of improving dose distributions and other clinically relevant factors as well as enhancing radiation safety. Rat 9L gliosarcoma cells growing in vitro have been used as a model to determine the role of fraction size when individual pulses of irradiation are given at appropriate intervals to result in an overall dose rate that is identical to currently applied continuous low dose rate irradiation. With an overall dose rate of 0.

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Purpose: Preferential amplification of low dose-rate irradiation toxicity in tumor cells is one way of improving presently applied brachytherapy. Low temperature hyperthermia applied to a tumor volume during irradiation is one candidate for reaching this goal. The ranges of relevant temperatures and dose-rate have been determined in a tissue culture system.

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Third-year medical students participated in a program using a meal conference approach to teach ambulatory nutrition concepts called "Building Better Health Through Nutrition." The series of three interactive presentations was given during the required family medicine clerkship. A pretest and posttest were used to measure acquisition of nutrition knowledge.

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Following evidence of reduced efficacy of ivermectin in a field population of Haemonchus contortus in Brazil, this strain of the parasite was submitted to a controlled anthelmintic test. Eighty worm-free lambs were randomly split into two groups of 40. Each lamb in the first group was infected with 5000 third stage larvae (L3) of the ivermectin-resistant strain; the remaining 40 lambs were each infected with 5000 L3 of a H.

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Modification of survival by long duration, 41 degrees C hyperthermia in combination with low dose rate radiation (0.5 Gy/h) was determined in rat 9L gliosarcoma cells. Cells were exposed to radiation in a manner that simulated continuous irradiation at a dose rate relevant to clinical brachytherapy.

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A strain of Haemonchus contortus resistant to the benzimidazoles, ivermectin and salicylanilides was used to study the effect of exposure to ivermectin or oxfendazole on the number of eggs produced by adult female parasites. After anthelmintic administration there was a reduction in the faecal egg count of the infected lambs. Ivermectin caused a reduction in the number of eggs within adult parasites for up to 72 hours but this returned to higher than pre-treatment levels at 168 hours after treatment.

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An intravenous glucose sensor was implanted in six dogs for 1-15 wk. The glucose sensor is a flexible cylinder, approximately 0.2 cm diam and 30 cm long, with a tip containing immobilized glucose oxidase and catalase coupled to a potentiostatic O2 sensor.

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The severity of bone disease in phosphopenic rickets is not correlated with serum phosphate levels. In order to determine whether growth hormone (GH) secretion may influence rachitic changes, we evaluated the 24 h integrated concentration of growth hormone (IC-GH) in five children with phosphopenic rickets. Two patients with marked clinical and roentgenographic rachitic abnormalities had normal IC-GH levels.

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An isolated in-vitro perifused interrenal gland preparation from the dogfish Scyliorhinus canicula was used to study production of quantitatively the major corticosteroid 1 alpha-hydroxycorticosterone (1 alpha-OH-B), measured by radioimmunoassay. Basal secretory rates were 877.1 +/- 145 (S.

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To investigate the possibility that heat-induced protein degradation may play a role in heat killing of mammalian cells, we have compared cellular survival and protein degradation rates for cells treated with cycloheximide, puromycin, or histidinol. These three compounds all inhibit protein synthesis and protect against the lethal effects of heat shock. When cells were treated with histidinol for 2 h before heating, as well as during heating at 43 degrees C for 3 h, they became resistant to heat killing.

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The formation of new membrane vesicles normally occurs during eukaryotic organellogenesis and maturation of bacteriophage PM2. This virus was studied as a simple model for membrane morphogenesis. Previous biochemical and genetic studies suggest that a major structural protein of PM2, sp6.

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Chinese hamster ovary (CHO) cells became thermotolerant after treatment with either heat for 10 min at 45.5 degrees C or incubation in 100 microM sodium arsenite for 1 h at 37 degrees C. Thermotolerance was tested using heat treatment at 45 degrees C or 43 degrees C administered 6-12 h after the inducing agent.

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An overall increase of 40% in nuclear-associated protein has been shown to be one of the sequellae of exposure of eukaryotic cells to elevated temperatures. Several investigators have shown that the increased protein/DNA ratios correlated well with the degree of cytotoxicity. In previous investigations, we have shown that cycloheximide, which protects the cell from the killing effects of heat, produces a dramatic reduction of the bulk nuclear-associated proteins after heating.

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The mechanism by which Cycloheximide (CHM) protects cells from heat induced killing has been investigated. Cycloheximide (10 micrograms/ml) added for 2 hr before and during a 3 hour heating at 43 degrees C prevented a 40% increase of heat-induced protein accumulation in the nucleus and protected cells (0.0001 vs.

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The activity of 394 spontaneously active neurons located in the ganglionated plexus of the ventral epicardial fat pad overlying the right atrium and pulmonary veins was recorded. Ganglia that contained various numbers of neurons, many with two or more nucleoli, were identified adjacent to the recording sites. Spontaneous activity was correlated with the cardiac cycle in 39% and with the respiratory cycle in 8% of the identified neurons.

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A unique direct-view stereo electron microscope technique was used to visualize the structure and three-dimensional distributions of mitochondria in CHO cells in situ following hyperthermic treatments. Aberrations induced by various heating regimens were recorded. The protocol included a trypsin digestion that may have enhanced the expression of the initial heat damage.

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1. Clonidine, an alpha 2-adrenergic agonist, is thought to inhibit noradrenergic neuronal activity (NNA) in the central nervous system (CNS) by a presynaptic alpha 2-receptor mechanism. Central NNA is thought to be the primary monoaminergic stimulus to pituitary ACTH release.

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The complete amino acid sequence of the BSC-1 cell growth inhibitor, including its precursor polypeptide, is reported. The sequence was deduced from the nucleotide sequence of the cDNA. The N-terminal amino acid sequence of the mature bioactive BSC-1 cell growth inhibitor is identical with the N-terminal sequences of the factors that have been called type beta 2 transforming growth factor and cartilage-inducing factor B, suggesting that these are identical.

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Rat 13762NF mammary adenocarcinoma cells (clone MTC) were heated to 42 degrees C either in vivo as a subcutaneous tumour in the rat mammary fat pad or in vitro as attached cells. Labelling in vivo or in vitro detected very similar heat-stress proteins (hsp) at 160, 112, 90, 70 and 56 kDa. Syngeneic rat endothelial and macrophage cells synthesized several cellular proteins in vitro differently than did the tumour cells in vitro, but both types of normal cells were similar to tumour cells in the hsp synthesized.

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The complete nucleotide sequences of RNA gamma from the Type and ND18 strains of barley stripe mosaic virus (BSMV) have been determined. The sequences are 3164 (Type) and 2791 (ND18) nucleotides in length. Both sequences contain a 5'-noncoding region (87 or 88 nucleotides) which is followed by a long open reading frame (ORF1).

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3H-clonidine and 3H-imipramine binding were measured in depressed patients, 55 years and older. There was no significant difference in either 3H-clonidine or 3H-imipramine binding between depressed patients and age- and sex-matched controls. There was no significant correlation between 3H-clonidine or 3H-imipramine binding and severity of depression before treatment.

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Acute transmural myocardial infarction has been reported to functionally denervate the normal myocardium distal to the infarcted zone by interrupting neurotransmission in axons coursing in the subepicardial region of the myocardial necrosis. To directly investigate the viability of such neurotransmission, the effects of acute transmural myocardial infarction on conduction in the intrinsic cardiac nerves overlying and distal to an experimentally induced acute transmural myocardial infarction were studied. In eight dogs, during control states electrical stimulation of the epicardium adjacent to a coronary artery produced compound action potentials in the more cranially located cardiopulmonary nerves.

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