Lentiviral vectors and antiretroviral intrinsic immunity

Multicellular organisms have evolved under relentless attacks from pathogens, and as a consequence have spiked their genomes with numerous genes that serve to thwart these threats, notably through the building of the innate and adaptive arms of the immune system. The innate immune system is by far the most ancient, being found as widely as in plants and Drosophila, while adaptive immunity arose with the emergence of cartilaginous fishes. Innate immunity enters rapidly into the game during the course of an infection and generally involves the recognition by specific cellular receptors of common pathogen-associated patterns to elicit broad defensive responses, mediated in humans by interferons, macrophages, and natural killer cells, amongst others. When innate immunity fails to eradicate the infection quickly, adaptive immune responses enter into play, to generate exquisitely specific defenses to virtually any pathogen, thanks to a quasi-infinite repertoire of nonself receptors and effectors. A specific form of innate immunity, coined "intrinsic immunity," completes this protection by providing a constant, always-on, line of defense, generally through intracellular obstacles to the replication of pathogens. This component of the immune system has gained much attention as it was discovered that it is a cornerstone of the resistance of mammals against retroviruses. One of these newly discovered intracellular molecular weapons, the APOBEC family of proteins, is active against several classes of retroelements. We present here the current state of knowledge on this rapidly evolving field and discuss implications for gene therapy.     

Human coronavirus NL63 infection in Canada

The isolation of human coronavirus NL63 (HCoV-NL63) in The Netherlands raised questions about its contribution to respiratory illness. In this study, a total of 525 respiratory specimens, collected in Canada primarily during the winter months of 2001-2002, were tested for HCoV-NL63; 19 tested positive for HCoV-NL63, demonstrating virus activity during January-March 2002. Patients with HCoV-NL63 were 1 month-100 years old (median age, 37 years). The main clinical presentations were fever (15/19), sore throat (5/19), and cough (9/19), and 4 patients were hospitalized. These results provide evidence for the worldwide distribution of HCoV-NL63.     

The interactions of amphiphilic antisense oligonucleotides with serum proteins and their effects on in vitro silencing activity

Antisense oligonucleotides (AONs) are a class of compounds with high therapeutic potential. One of the challenges facing this platform is the development of effective techniques to achieve cellular delivery. AON conjugates, in which traditional AONs are attached to certain biomolecules, can exhibit improved intracellular bioavailability in the absence of delivery systems. In this study, the lipophilic moieties docosahexaenoic acid, cholesterol, and docosanoic acid (DSA) were conjugated to various phosphorothioated DNA and chemically-modified 2'-fluoro-arabinonucleic acid AONs via an amino-hexanol-linker added to the 5'-end of the molecule. The gene silencing potential of these compounds was evaluated in vitro in the absence or presence of a transfecting agent (polyion complex micelle). Incubation with sub-micromolar concentration of DSA-conjugates could, in the absence of serum proteins, downregulate more than 60% of the targeted mRNA under carrier-free and carrier-loaded delivery methods. Gene silencing activity of carrier-free DSA-conjugates was, however, decreased in a dose-dependent fashion by adding albumin in the transfection medium. Supplementing the medium with free fatty acid prevented the interaction of the DSA-conjugate with albumin, and restored its silencing activity. These findings suggest that strategies aiming at preventing the association of hydrophobized AONs to serum proteins at the site of action may improve their activity.     

Comparison of hyperemic changes in carotid-radial pulse wave velocity by upper and lower arm cuff occlusion

Carotid-radial pulse wave velocity (PWV) normally decreases following release of upper arm cuff occlusion (hyperemia). Lower arm (LA) elicits less brachial artery dilation than upper arm (UA) occlusion but more closely reflects endothelial function. Using applanation tonometry, we compared changes (Δ) in PWV induced by UA and LA hyperemia in 65 healthy participants. Pulse wave velocity was measured serially. Both techniques decreased PWV maximally at 1 minute with gradual return to baseline by 9 minutes. ΔPWV(1min) was greater for UA than LA occlusion (-11.5% vs -6.8%, P = .02). Multivariate analysis showed arm location independently related to ΔPWV (P = .036). In participants with variable cardiovascular risk, PWV decline lessened with increasing Framingham risk for both techniques. In conclusion: UA and LA occlusion decrease PWV maximally at 1 minute after release of arterial occlusion. PWV(1min) decline are more marked after UA than LA occlusion and progressively lessens with increasing Framingham risk.     

Prediction of fluid responsiveness using respiratory variations in left ventricular stroke area by transoesophageal echocardiographic automated border detection in mechanically ventilated patients

Background  

Left ventricular stroke area by transoesophageal echocardiographic automated border detection has been shown to be strongly correlated to left ventricular stroke volume. Respiratory variations in left ventricular stroke volume or its surrogates are good predictors of fluid responsiveness in mechanically ventilated patients. We hypothesised that respiratory variations in left ventricular stroke area (ΔSA) can predict fluid responsiveness.     

Time estimation in chronic insomnia sufferers

STUDY OBJECTIVE: The objective of the present study is 2-fold: (1) compare the time-estimation performance of chronic insomnia sufferers to that of good sleepers and (2) evaluate the severity of the sleep complaint in order to assess its association with the time-estimation performance. DESIGN: Between subjects design. PARTICIPANTS: The sample included 11 individuals suffering from chronic primary insomnia (7 women and 4 men, mean age = 44.64 years, SD = 12.71) and 11 good sleepers (5 women and 6 men, mean age = 48.00 years, SD = 7.86). INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: All participants completed a time-estimation task, namely a finger-tapping task. The results indicate no significant between-group differences on time-estimation data, as well as no significant relationship between severity of insomnia complaint and estimation of time. CONCLUSION: These results suggest that the tendency to misestimate sleep difficulties is not linked to impaired time estimation-specific processes in insomnia sufferers, as measured with the present task.     

Pharmacological Survey of Medicinal Plants for Activity at Dopamine Receptor Subtypes. I. Activation of D1-Like Receptor Linked Adenylyl Cyclase

Nearly 100 aqueous, organic and alcoholic extracts of 46 Bolivian, Chinese and Indian medicinal plants were evaluated for their ability to stimulate adenylyl cyclase using Sf9 cells expressing rat D1a dopamine receptors in a broken cell assay. The aqueous extract of Cestrum parqui, a Bolivian plant of the Solanaceae, stimulated adenylyl cyclase in Sf9 cells expressing either rat D1a or rat D1b receptors, but no stimulation was observed in uninfected Sf9 cells. Flupenthixol, a nonselective dopaminergic antagonist, was found to attenuate both dopamine- and extract-dependent stimulation of adenylyl cyclase. The extract stimulated adenylyl cyclase in a concentration-dependent manner. However, adenylyl cyclase activity returned to basal levels at the highest concentration of extract that was tested. The extract was also evaluated for the ability to stimulate adenylyl cyclase in stably transfected HEK cells expressing human D1 receptors using a cAMP accumulation, whole cell assay. The extract stimulated HEK cells expressing human D1a dopamine receptors, but no enzyme stimulation was observed in untransfected HEK cells. Studies using transfected HEK cells expressing D2 receptors indicate that this extract also has intrinsic activity at D2 dopamine receptor. These studies suggest that this plant extract contains a component that is an agonist at dopamine receptors.     

Effect of speed on the energy cost of walking in unilateral traumatic lower limb amputees

In this work, the effect of walking speed on the energy expenditure in traumatic lower-limb amputees was studied. The oxygen consumption was measured in 10 transfemoral amputees, 9 transtibial amputees and 13 control subjects, while they stood and walked at different speeds from 0.3 m s(-1) to near their maximum sustainable speed. Standing energy expenditure rate was the same in lower-limb amputees and in control subjects (approximately 1.85 W kg(-1)). On the contrary, during walking, the net energy expenditure rate was 30-60% greater in transfemoral amputees and 0-15% greater in transtibial amputees than in control subjects. The maximal sustainable speed was about 1.2 m s(-1) in transfemoral amputees and 1.6 m s(-1) in transtibial amputees, whereas it was above 2 m s(-1) in control subjects. Among these three groups, the cost of transport versus speed presented a U-shaped curve; the minimum cost increased with the level of amputation, and the speed at which this minimum occurred decreased.