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C Harley

Publications and source records attributed to C Harley.

28 records · Page 2Linked to original sources
PubMed1986

DSP-4 treatment accelerates kindling.

Norepinephrine depletion of the central nervous system by peripheral N-(2-chloroethyl)-N-ethyl bromobenzylamine administration accelerates the development of seizures kindled by repeated stimulation of the amygdala. These data, in conjunction with previous 6-hydroxydopamine data, demonstrate the robustness of this phenomenon and emphasize the importance of noradrenergic innervation originating from the locus ceruleus in the suppression of seizure development.

Action Potentials↗
PubMed1985

Physical health correlates of attitudes toward aging in the elderly.

Attitudes toward aging were assessed in three groups of elderly men (age 65-85), including: hospitalized veterans, veteran outpatients, and a group of non-hospitalized "healthy" veteran volunteers, using the Rosencranz and McNevin Semantic Differential Scale. Social objects rated included an "old man", a "young man", and the participant, himself, ("self"). Attitudes toward "old men" were significantly more negative than attitudes toward "young men" in all three groups. In addition, significant group by "object-rated" interactions were obtained on the autonomous/dependent and instrumental/ineffective dimensions of this scale. These interactions were attributable to a more negative "self" rating by the hospitalized group. These results suggest that within the population studied, older persons in poor health tend to view themselves more like the stereotyped "old person" than do healthy old people, who tend to perceive themselves as being more like a "young person".

Aged↗
PubMed1984

A comparison of physical health and psychosocial variables as predictors of reaction time and serial learning performance in elderly men.

Choice reaction time and serial learning tasks were studied in three groups of elderly men (aged 65 to 85), including (a) hospitalized veterans, (b) veteran outpatients, and (c) nonhospitalized veteran volunteers. Demographic variables, life satisfaction, and attitudes toward aging, as well as objective and subjective measures of physical impairment, were assessed in each group. The three groups differed on both reaction time and serial learning measures. Multivariate analysis revealed that objective physical health assessments were the best predictors of reaction time performance, whereas subjective assessments best predicted serial learning performance. More negative attitudes and life satisfaction were associated with impaired physical health, but these psychosocial measures were poor predictors of behavioral performance.

Aged↗
PubMed1982

Acetylcholinesterase in pontomedullary catecholamine neurons of the adult albino rat.

This study investigated the cholinesterasic reactivity of catecholamine neurons in the rat hindbrain with the aid of a two-step histochemical procedure. First, catecholamine cells were visualized by their formaldehyde/glutaraldehyde induced specific histofluorescence and then poststained in the same tissue with a thiocholine technique for acetylcholinesterase (AChE). Processing the vibratome-sectioned tissue in phosphate buffer subsequent to initial aldehyde fixation permitted satisfactory preservation of both amine fluorophores and esterasic reactivity. Our results, in both randomly sampled and serially sectioned material, unequivocally establish the presence of AChE in all pontomedullary cell groups emitting catecholamine fluorescence, the majority of which are known to consist of noradrenaline perikarya. Hence in contrast to previous reports the occurrence of AChE in central noradrenaline neurons appears to be generalized. The intensity of histofluorescence and esterasic staining were uncorrelated in most regions. It remains for future study to determine whether AChE in brain catecholamine neurons indicates their cholinoceptivity or subserves the catabolism of other neuromediators such as substance P.

Acetylcholinesterase↗
PubMed1981

Mechanism of resistance of variants of the Lewis lung carcinoma to N-(phosphonacetyl)-L-aspartic acid.

Variants of the Lewis lung carcinoma were selected for resistance to N-(phosphonacetyl)-L-aspartic acid (PALA) by treatment of tumor-bearing mice with repetitive subcurative doses of PALA. The specific activity of the target enzyme, L-aspartic acid transcarbamylase (ATCase), was measured in the four variants developed. Three had markedly elevated ATCase activities; however, the fourth line, LL/PALA-C, had an ATCase activity identical to that of the parent, PALA-sensitive line (LL/O). One high-ATCase variant, LL/PALA-J, and LL/PALA-C were compared with LL/O in subsequent biochemical studies on the mechanism of resistance to PALA. Enzyme activities in the salvage pathways which phosphorylate pyrimidine nucleosides and deoxynucleosides were found to be similar in all three lines. ATCase in these lines exhibits closely comparable kinetics with its natural substrates as well as with PALA. The time courses of restitution of ATCase after a single therapeutic dose of PALA show that both resistant variants recover full activity more rapidly than the parent. Additionally, inhibition of ATCase 24 hr following graded doses of PALA is lower in the resistant lines. The uptake of [14C]PALA in vitro into cell lines derived from the three Lewis lung carcinomas apparently occurs by passive diffusion and at comparable rates in both sensitive and resistant cells. Analysis of the nucleotide content of tumors reveals comparable spectrums of purine and pyrimidine nucleotide levels in the LL/O and LL/PALA-C lines, whereas the LL/PALA-J line has augmented nucleotide pools. In all three lines, 24 hr after treatment with PALA (400 mg/kg), uridine and cytidine nucleotide levels were substantially diminished (70 to 80%) while adenosine 5'-triphosphate and guanosine 5'-triphosphate levels were elevated (50 to 100%). Estimations of precursor flux through the de novo pyrimidine pathway by measuring orotate and orotidine levels in tumors of mice treated with pyrazofurin (an inhibitor of orotidine-5'-monophosphate decarboxylase) and either 0.9% NaCl solution or PALA shows that PALA treatment eliminates orotate and orotidine accumulation in LL/O but reduces it by only 75 and 50% in LL/PALA-C and LL/PALA-J, respectively. Similarly, PALA treatment (20 microM) of tumor lines in culture provokes a dramatic decrease in the incorporation of NaH14CO3 into pyrimidine intermediates and nucleotides in the LL/O cell line only. Determinations of specific activities of the other enzymes in this pathway reveal that the activity of carbamyl phosphate synthetase II, the rate-limiting step, is elevated 2- to 3-fold in both resistant lines. Since carbamyl phosphate synthetase II exists as a complex with ATCase, the suggestion is made that levels of carbamyl phosphate synthetase II are collaterally important determinants of PALA activity. An augmented pool of carbamyl phosphate in the resistant variants may serve to competitively displace PALA from ATCase, diminish enzyme inhibition, and allow pyrimidine biosynthesis to proceed despite therapy.

Amides↗
PubMed1978

Partial purification, characterization, and assay of a slightly acidic insulin-like peptide (ILAs) from human plasma.

An insulin radioreceptor assay (RRA) using human placental microsomal membranes was used to measure insulin-like activity (ILA) extracted from human plasma concentrates (Cohn fraction IV-4) by acid ethanol. The soluble activity (ILAs), chromatographed on Sephadex G-75 in 1 M acetic acid, migrated as a small molecule (fractional elution volume, 0.56) ahead of insulin (fractional elution volume, 0.70), whereas at neutral pH, ILAs migrated as a large molecular weight species. The ILAs peak from acid gel filtration on Sephadex was further purified by chromatography on carboxymethyl cellulose (CMC). The ILAs peak from both Sephadex and CMC diluted parallel to the porcine insulin standard in the insulin RRA and was totally unreactive in an insulin RIA. The CMC-purified material was iodinated and purified by binding to and elution from human placental membranes. The binding of [125I]ILAs to human placental membranes was inhibited only minimally by insulin and proinsulin and not at all by epidermal growth factor, nerve growth factor, glucagon, or lactogenic hormones, including human growth hormone. Multiplication-stimulating activity (MSA) inhibited in a manner parallel to ILAs. A Scatchard plot of the binding data was nonlinear. Sephadex ILAs was subjected to isoelectric focusing. The fractions assayed in both insulin and ILAs RRAs yielded comparable results. Peaks of ILA were observed at pHs 5.3, 6.6, and 8.4. When CMC-ILA was subjected to isoelectric focusing in polyacrylamide, a single peak of activity migrating between pH 6.2-6.8 was seen. [125I]ILAs focused at exactly the same pH. Electrophoresis of CMC-ILAs in acid-urea revealed a sharp peak of activity migrating with one of the five protein bands seen after staining. Again, [125I]ILAs comigrated with unlabeled ILAs. The molecular weight of ILAs, as determined on a calibrated Sephadex G-150 column at neutral pH, was 9,000-10,000 daltons. CMC-ILAs stimulated [14C]glucose incorporation into triglycerides of rat adipose tissue and augmented [3H]thymidine incorporation into human fibroblasts, chicken embryo fibroblasts, and BALB 3T3 cells as well as [35S]sulfate incorporation into macromolecules of rabbit chondrocyte culture medium. In summary, ILAs isolated on the basis of a RRA for insulin is a slightly acidic peptide with some of the biological activities expected of a somatomedin.

Adipose Tissue↗
PubMedDate not supplied

Telomerase inhibitors--oligonucleotide phosphoramidates as potential therapeutic agents.

We have designed, synthesized, and evaluated using physical, chemical and biochemical assays various oligonucleotide N3'-->P5' phosphoramidates, as potential telomerase inhibitors. Among the prepared compounds were 2'-deoxy, 2'-hydroxy, 2'-methoxy, 2'-ribo-fluoro, and 2'-arabino-fluoro oligonucleotide phosphoramidates, as well as novel N3'-->P5' thio-phosphoramidates. The compounds demonstrated sequence specific and dose dependent activity with IC50 values in the sub-nM to pM concentration range.

Amides↗