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S Barlow

Publications and source records attributed to S Barlow.

14 recordsLinked to original sources

Stable expression of heterologous microtubule-associated proteins (MAPs) in Chinese hamster ovary cells: evidence for differing roles of MAPs in microtubule organization.

To study the effects of microtubule-associated proteins (MAPs) on in vivo microtubule assembly, cDNAs containing the complete coding sequences of a Drosophila 205-kD heat stable MAP, human MAP 4, and human tau were stably transfected into CHO cells. Constitutive expression of the transfected genes was low in most cases and had no obvious effects on the viability of the transfected cell lines. High levels of expression, as judged by Western blots, immunofluorescence, and Northern blots, could be induced by treating cells with sodium butyrate. High levels of MAPs were maintained for at least 24-48 h after removal of the sodium butyrate. Immunofluorescence analysis indicated that all three MAPs bound to cellular microtubules, but only the transfected tau caused a rearrangement of microtubules into bundles. Despite high levels of expression of these exogenous MAPs and the bundling of microtubules in cells expressing tau, transfected cells had normal levels of assembled and unassembled tubulin. With the exception of the tau-induced bundles, microtubules in transfected cells showed the same sensitivity as control cells to microtubule depolymerization by Colcemid. Further, all three MAPs were ineffective in reversing the taxol-dependent phenotype of a CHO mutant cell line. The absence of a quantitative effect of any of these heterologous proteins on the assembly of tubulin suggests that these MAPs may have different roles in vivo from those inferred previously from in vitro experiments.

Animals

How should we define the caring role? Broadening the parameters of the concept of care.

There are many different interpretations of the dynamics of the nurse/patient relationship and the contrasting needs and priorities nurses and patients attach to it. This article outlines varying interpretations of the concept of care, and suggests the concept can be broadened to reflect the physical, emotional, cognitive and intuitive aspects of the caring role.

Humans

Synthesis of carbonic anhydrase in rabbit and chicken reticulocyte lysates.

The synthesis of carbonic anhydrase, the second most abundant soluble protein of red blood cells, is shown to occur in rabbit and chicken reticulocyte lysates. This translation product was identified by chloroform/ethanol extraction, polyacrylamide gel electrophoresis in sodium dodecylsulphate and peptide mapping. In rabbit retic-locyte lysates, predominantly one of the two red cell isozymes, carbonic anhydrase I, is synthesised. The proportion of carbonic anhydrase synthesis (0.2-0.8% of total protein synthesis) in vitro is comparable to that (0.2-1.0%) in vivo for both rabbit and chicken reticulocytes.

Amino Acids

Investigations into the mechanism of reduction of ethanol sleep by thyrotropin-releasing hormone (TRH).

Thyrotropin-releasing hormone (TRH), administered intraperitoneally, was found to antagonize ethanol-induced sleep and hypothermia in mice without affecting brain ethanol content. This reduction of the actions of ethanol was also apparent after oral or intracisternal administration of TRH. In addition, TRH reduced ethanol-induced sleep in rats, hamsters, gerbils and guinea pigs. Evidence that the pituitary-thyroid axis is not necessary for the effects of TRH was provided by observations that hypophysectomy did not reduce TRH antagonism of ethanol narcosis and findings that neither triiodothyronine nor thyrotropin mimicked its action. Certain analogs of TRH, which have little effect on the pituitary, were also found to antagonize ethanol-induced sleep and hypothermia. Pretreatment with the antiadrenergic drugs, alpha-methyltyrosine, phentolamine and propranolol did not antagonize the ability of TRH to reduce sleep induced by ethanol. However, after intracisternal administration of atropine methyl nitrate, TRH no longer caused a significant reduction of sleep, even though TRH antagonism of the ethanol-induced hypothermia was still apparent. In contrast, central administration of other anticholinergic drugs, such as delta-tobocurarine and hexamethonium, reduced ethanol-induced sleep and this effect was additive with TRH. Carbachol also reduced ethanol sleeping time and this effect was also blocked by atropine methyl nitrate. The antagonism of ethanol-induced sleep by dibutyryl cyclic adenosine 3', 5'-monophosphate was significantly reduced but not blocked by atropine methyl nitrate. Results provide evidence that TRH has a direct extrapituitary action on brain and that both TRH and ethanol may interact with central cholinergic systems.

Animals