Alfalfa seeds: Effects on cholesterol metabolism

Summary Plasma cholesterol concentrations were reduced in 3 human volunteers during ingestion of diets containing alfalfa seeds (AS) for 3 weeks. No signs of toxicity were detected through serum determinations of multiple parameters. The ingestion of AS in rats decreased the concentration of plasma cholesterol, reduced intestinal absorption of exogenous and endogenous cholesterol, and increased fecal biliary excretion.The work described in this article, Publication No. 1082 of the Oregon Regional Primate Research Center, was supported with grants RR-00163 and HL-16587 from the National Institutes of Health.     

Focusing on phosphomonohydrolases: a timely choice

Cellular and Molecular Life Sciences -     

Histone deacetylases: Focus on the nervous system

Neurodegenerative disease strikes millions worldwide and there is mounting evidence suggesting that underlying the onset and progression of these debilitating diseases is inappropriate neuronal apoptosis. Recent reports have implicated a family of proteins known as histone deacetylases (HDACs) in various neuronal processes including the neuronal death program. Initial headway in this field has been made largely through the use of broad-spectrum HDAC inhibitors. In fact, pharmacological inhibition of HDAC activity has been shown to protect neurons in several models of neurodegeneration. The observation that HDAC inhibitors can have opposing effects in different paradigms of neurodegeneration suggests that individual members of the HDAC protein family may play distinct roles that could depend on the specific cell type under study. The purpose of this review is to detail work involving the use of HDAC inhibitors within the context of neurodegeneration and examine the roles of individual HDAC members in the nervous system with specific focus on neuronal cell death. Received 25 January 2007; received after revision 3 April 2007; accepted 26 April 2007     

ACTH: Differential effects on avoidance and discrimination

Zusammenfassung Andauernde ACTH-Behandlung beeinflusst sowohl Vermeidungs- als auch Fehlerkomponenten im Zweiwahl-Y-Labyrinthtest. Die Einwirkungen waren von der Intensität des Elektroschocks wie auch von der Reaktionsfähigkeit der Tiere abhängig.

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This work was supported by Medical Research Council Grant No. MA 1746. Some of the work was done while the first author held a pre-doctoral terminal year grant from the USPHS and while the second author held a Research Career Award from the Canadian Association for Retarded Children. We are indebted toSusanna Kertesz for help in running the subjects in these studies. Requests for reprints should be sent to Dr.J. A. Corson, Allan Memorial Institute, 1033 Pine Avenue West, Montreal 112 (P.Q., Canada).     

Loperamide: novel effects on capacitative calcium influx

Loperamide is a widely used antidiarrheal that primarily acts at nanomolar concentrations through activation of opioid receptors in the gastrointestinal tract. At somewhat higher concentrations, loperamide blocks calmodulin activity, calcium channels, N-methyl-D-aspartate-receptor channels, and maitotoxin-elicited calcium influx. Loperamide at micromolar concentrations has now been shown to have a remarkable stimulatory effect on the capacitative calcium influx that is triggered in many cells by depletion of the inositol-trisphosphate-sensitive stores of calcium in the endoplasmic reticulum. The mechanism whereby loperamide enhances levels of intracellular calcium elevated by capacitative calcium influx is, as yet, undefined.     

Alpha-tocopherol: Its inhibition on human platelet aggregation

Summary Alpha-tocopherol inhibits human platelet aggregation induced by arachidonate sodium, collagen, epinephrine, adenosine diphosphate or thrombin — arachidonate sodium being the most susceptible. The second phase of the biphasic platelet aggregation induced by epinephrine or adenosine diphosphate is preferentially inhibited.This work was supported by the Medical Research Council of Canada, Quebec Medical Council, and a Fraser Scholarship, McGill University. I thank Drs.K. N. Drummond andS. O'Regan for their comments.     

The buzz on caffeine in invertebrates: effects on behavior and molecular mechanisms

A number of recent studies from as diverse fields as plant–pollinator interactions, analyses of caffeine as an environmental pollutant, and the ability of caffeine to provide protection against neurodegenerative diseases have generated interest in understanding the actions of caffeine in invertebrates. This review summarizes what is currently known about the effects of caffeine on behavior and its molecular mechanisms in invertebrates. Caffeine appears to have similar effects on locomotion and sleep in both invertebrates and mammals. Furthermore, as in mammals, caffeine appears to have complex effects on learning and memory. However, the underlying mechanisms for these effects may differ between invertebrates and vertebrates. While caffeine’s ability to cause release of intracellular calcium stores via ryanodine receptors and its actions as a phosphodiesterase inhibitor have been clearly established in invertebrates, its ability to interact with invertebrate adenosine receptors remains an important open question. Initial studies in insects and mollusks suggest an interaction between caffeine and the dopamine signaling pathway; more work needs to be done to understand the mechanisms by which caffeine influences signaling via biogenic amines. As of yet, little is known about whether other actions of caffeine in vertebrates, such as its effects on GABA_A and glycine receptors, are conserved. Furthermore, the pharmacokinetics of caffeine remains to be elucidated. Overall behavioral responses to caffeine appear to be conserved amongst organisms; however, we are just beginning to understand the mechanisms underlying its effects across animal phyla.     

Flagellar hairs on zoospores ofPhytophthora species: Tip hairs on the whiplash flagellum

Résumé Des mastigonèmes de 460–500 nm de longueur et 11–12 nm de largeur existent à l'extrémité du flagelle whiplash des zoospores desPhytophthora cinnamomi, P.megasperma var.sojae, P. palmivora etP. parasitica. Des mastigonèmes latéraux existent aussi sur le flagelle whiplash des 4 espèces. C'est la première mention de mastigonèmes latéraux sur le flagelle whiplash deP. cinnamomi et deP. megasperma var.sojae.     

Alpha-tocopherol: its inhibition on human platelet aggregation.

Alpha-tocopherol inhibits human platelet aggregation induced by arachidonate sodium, collagen, epinephrine, adenosine diphosphate or thrombin - arachidonate sodium being the most susceptible. The second phase of the biphasic platelet aggregation induced by epinephrine or adenosine diphosphate is preferentially inhibited.     

Gaucher disease: Perspectives on a prototype lysosomal disease

Gaucher disease is an autosomal recessive trait and the most common lysosomal storage disease. The pathogenesis evolves from the diminished activity of the lysosomal hydrolase, acid beta-glucosidase and the resultant accumulation of glucosylceramide within lysosomes. The pathogenic mechanisms are poorly understood. During the past 2 decades, progress has been made in understanding the biochemical basis and molecular biology of the disease, but more fundamental knowledge is required to relate these advances to the cell and whole body phenotypes. Despite this lack of understanding, enzyme replacement therapy has proved a successful and effective management for Gaucher disease. However, basic details of this therapeutic efficacy require elucidation. Here, we review the current state of the molecular pathogenesis and provide our perspective of some major issues for continued advances in this prototype lysosomal storage disease.     

Actants and enframing: Heidegger and Latour on technology

A central issue in the philosophy of technology concerns the relationship between technology and the conditions under which technology develops. Traditionally, two main accounts are given of this relationship. The social constructivist approach considers technology to be largely determined by “social” factors (e.g. military interests, economic policy). By contrast, technological determinism describes technology as self-determinative, and as following its own independent aim of greater efficiency. This paper discusses two alternatives to these conceptions of technology, namely, the accounts offered by Bruno Latour and Martin Heidegger. It examines their common theses that our present misunderstanding of technology is due to a continued commitment to the subject–object distinction. The paper further compares their accounts, which attempt to overcome this distinction, and argues that ultimately both authors fail to find a role for human beings that is consistent with their contention that we need to develop a less anthropocentric understanding of the world.