Novel naphthoquinones from Conospermum incurvum

During the reisolation of the trimeric naphthoquinone derivative conocurvone [1] from an extract of the Australian shrub Conospermum incurvum, six monomeric naphthoquinones were isolated. These include three novel 1,4-naphthoquinone derivatives: 3-methyl-14,15-dihydro-15-hydroxyteretifolione B [3], 3-methyl-14,15-dihydro-15-hydroxyteretifolione B methyl ether [4], and 2,3-dimethyl-6-hydroxy-7-methoxy-1,4-naphthoquinone [5]. In addition, the previously reported compounds 3-methylteretifolione B [6], 3-methylteretifolione B methyl ether [7], and 8-geranyl-2,7-dihydroxy-3-methyl-1,4-naphthoquinone [8] were isolated and identified. The structures of the novel 1,4-naphthoquinones were elucidated by spectral methods. While conocurvone [1] is a potent inhibitor of HIV-1-induced cell killing, all of the monomeric naphthoquinone derivatives were inactive against HIV-1.     

Behavioral and neural approaches to the function of the mystacial vibrissae.

Reviews the behavioral functions of mystacial vibrissae through studies of (a) the activity of fibrissae during behavior, (b) single-unit responses to stimulation of vibrissae, and (c) the behavioral effects of removing vibrissae. Hypotheses for behavioral investigation are evaluated against older approaches. Neural and behavioral plasticity are discussed in the light of recent investigations of barrel formations in the somatosensory cortex and of locomotor behavior during exploration. (2 p ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An evidence-based approach to interactive health communication: a challenge to medicine in the information age. Science Panel on Interactive Communication and Health

OBJECTIVE: To examine the current status of interactive health communication (IHC) and propose evidence-based approaches to improve the quality of such applications. PARTICIPANTS: The Science Panel on Interactive Communication and Health, a 14-member, nonfederal panel with expertise in clinical medicine and nursing, public health, media and instructional design, health systems engineering, decision sciences, computer and communication technologies, and health communication, convened by the Office of Disease Prevention and Health Promotion, US Department of Health and Human Services. EVIDENCE: Published studies, online resources, expert panel opinions, and opinions from outside experts in fields related to IHC. CONSENSUS PROCESS: The panel met 9 times during more than 2 years. Government agencies and private-sector experts provided review and feedback on the panel's work. CONCLUSIONS: Interactive health communication applications have great potential to improve health, but they may also cause harm. To date, few applications have been adequately evaluated. Physicians and other health professionals should promote and participate in an evidence-based approach to the development and diffusion of IHC applications and endorse efforts to rigorously evaluate the safety, quality, and utility of these resources. A standardized reporting template is proposed to help developers and evaluators of IHC applications conduct evaluations and disclose their results and to help clinicians, purchasers, and consumers judge the quality of IHC applications.     

Calcium channel blockade inhibits platelet activating factor production by human umbilical vein endothelial cells

An increase in intracellular calcium level is an important signal in the regulation of cellular responses under normal and pathological conditions. Because two key enzymes in the synthetic pathway of platelet activating factor (PAF), phospholipase A₂ and acetyltransferase, are calcium dependent, we hypothesized that calcium channel blockade may inhibit agonist-induced PAF synthesis. Primary cultures of human umbilical vein endothelial cells (EC), pre-incubated with [³H]acetate, were exposed to thrombin (5 U/mL) and PAF production was quantitated by incorporation of radiolabel into the EC lipid fraction co-migrating with exogenous PAF in thin-layer chromatography. The effect of pre-incubation with calcium channel blockers (verapamil, diltiazem, 10⁻⁴ M) or buffer was determined. Results (triplicate experiments,^*P<0.05 vs buffer, † P<0.05 vs thrombin) demonstates that pre-incubation with calcium channel blocker markedly inhibits thrombin-induced PAF production (verapamil: buffer 273±122, thrombicin 10,735±1524^*, thrombin+verapamil 178±91 † cpm/plate; diltiazem: buffer 1097±581, thrombin 15,283±2661^*, thrombin+diltiazem 280±56 † cpm/plate). The effect of dialtiazem was dosedependent (% inhibition: 10⁻⁷ M, 46%; 10⁻⁵ M, 60%; 10⁻⁴ M, 98%). Diltiazem also inhibited bradykinin (10⁻⁸ M) induced PAF synthesis. In calcium-free medium or in the presence of LaCl₃ (10⁻³ M), the PAF response of EC to thrombin was blunted (buffer 582±360, thrombin 5394±1069, thrombin+calcium free medium 1055 ±571, thrombin+LaCl₃ 1271±58 cpm/plate). We conclude that calcium channel blockers present agonist-induced PAF synthesis, possibly by preventing cellular calcium influx and activation of PAF synthetic enzymes. We speculate that this mechanism may underlie, at least in part, the beneficial effect of calcium channel blockade under various pathological conditions. Based on a paper presented at the Third International Conference on Platelet-Activating Factor and structurally Related Alkyl Ether Lipids, Tokyo, Japan, May 1989.     

Acute poisoning with dextropropoxyphene. Clinical symptoms and plasma concentrations

Twenty-four undergraduate male volunteers participated in an experimental designed to assess the effect of voluntary control of heart rate deceleration on skin conductance level. One group of subjects received heart rate feedback training and a second group performed a tracking task. Because heart-rate feedback was presented via a visual display, the tracking task group was included to control for display monitoring influences on heart rate. Results demonstrated feedback mediated acquisition of learned control of heart rate slowing. More importantly, the heart-rate slowing performance was accompanied by increases in skin conductance level. This 'fractionation' of physiological responding suggests the presence of a physiological response pattern which may counter initial attempts to produce greater magnitude slowing effects.     

Contraindications to the repositioning of fractured or dislocated limbs in the fields

Supracondylar fractures of the femor or humerus and fractures of the radius, ulna, tibia or fibula, plus crush injuries of the limbs, most likely should not be manipulated in the field because of the potential for traumatizing adjacent nerves, veins and arteries. An emergency splinting system that allows immobilization without repositioning has been developed. Furthermore, fractures in or about the elbow, wrist, knee, or ankle should not be subjected to reduction in the field, unless there are compelling reasons to justify the risk of producing significant additional trauma. Conservative immobilization without repositioning may yield a more positive prognosis for the patient.     

A “Weighted Aggregate” Approach to R & D Project Selection

This article describes a general model for setting priorities on proposed R & D projects. It reports on research that evaluates methods for implementing the model. Specifically investigated were techniques for establishing criteria weights, assigning quantitative scales to qualitative criteria and modifying the model to improve its performance. Methods for solving the problem of criteria independence and for estimating probability of project success are proposed, but not tested.