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Abstract: Agonist-induced tone oscillations (rhythmic contractions and relaxations) occur in vascular beds to allow acute regulation of volume flow and thus the delivery of oxygen and nutrients to the tissue. Mechanisms responsible for the control of human placental vasomotor tone and blood flow are poorly characterized. This study aimed to characterise thromboxane-induced tone oscillations in human placental and myometrial arteries. Chorionic plate and myometrial arteries obtained from biopsies at term were mounted for isometric tension measurement. Tone oscillations were observed in chorionic arteries only when exposed to sub-maximal (<1μM) concentrations of U46619. Slow (mean±SEM) frequency (2.6±0.5 per hour), large amplitude (39±7% of peak contraction) tone oscillations were elicited by 0.03μM U46619 (n =18). In the presence of the nitric oxide synthase (NOS) inhibitor l-NNA (100μM) the amplitude was significantly reduced (40±13% to 18±8%, P <0.05, n =6), frequency was unaltered and the bradykinin-dependent vasodilator response was reduced (68±13% to 40±19%, P <0.05, n =6). Myometrial arteries exposed to 1μM U46619 developed tone oscillations within 10min, which increased in amplitude over 30min occurring at relatively constant frequency. The mean amplitude of oscillations at 30min (31±7%, n =16) was similar to that in chorionic arteries but the occurrence more frequent (42.8±9.7 per hour, P <0.001). Inhibition of NOS did not alter tone oscillations in myometrial arteries. Tone oscillations in chorionic arteries from pre-eclamptic and growth restricted (FGR) pregnancies were reduced in amplitude whereas those in myometrial arteries had increased frequency. Inhibition of NOS further reduced oscillation amplitude in chorionic arteries from FGR pregnancies. The alterations may contribute to the vasculopathology of these conditions, or, may represent compensatory mechanisms to maintain a matching of materno-placental blood flow. [Copyright &y& Elsevier]

The ability of a blood vessel to develop tone is dependent upon morphological parameters of the smooth muscle cells (SMC), including density, relationship with the endothelium and subcellular distribution of myofilaments and intracellular organelles. Consequently, wall ultrastructure of isolated human placental chorionic plate arteries (n =12), fixed when pressurised to mimic their in vivo geometry, was examined qualitatively using electron microscopy, and compared with maternal arteries (omental, n =10, myometrial, n =6). Arteries from women with uncomplicated pregnancy were tested for contractile viability before fixing, with some vessels post-fixed in osmium-ferricyanide for sarcoplasmic reticulum (SR) identification. In contrast to maternal arteries, placental arteries had no internal elastic lamina but exhibited considerable extracellular matrix separating circularly orientated SMC. Human SMC contained tightly packed arrays of myofilaments running parallel to the plasma membrane, enveloping cellular organelles. Synthetic SMC, with few myofilaments and much rough SR, were observed in placental arteries only. SR in SMC from maternal arteries was located centrally, often encircling mitochondria, and also near the plasma membrane associated with caveolae. Positive SR staining was rarely observed in SMC of placental arteries. This study highlights ultrastructural differences between placental and maternal arteries that may underlie specialised mechanisms of regulating vascular tone in the placenta. [Copyright &y& Elsevier]

Objectives. The aim of this study was to estimate the amount of mercury released into both air and saliva from fresh and aged, abraded amalgam discs and then investigate neurotoxic effects of inorganic mercury upon sensory neuronal cultures.Methods. An air-tight chamber was constructed to allow the combined estimation of mercury species released from amalgam pellets. The level released into air and saliva from both freshly packed and aged-abraded amalgam pellets was assessed. Dorsal root ganglia cultures from male CBA mice were exposed to 1 and 10 μM mercuric chloride concentrations. The effects of this were assessed by means of morphology, adhesion, size and immunocytochemistry.Results. The mercury released into air from dry fresh amalgam was low and less than the recommended industrial exposure limit for mercury. However, covering the discs with saliva reduced air–mercury levels by 46–56% and there was a statistically significant difference in the air–mercury levels recorded (p=0.013–0.048). The mercury released into air from dry abraded amalgam was shown to be above the recommended industrial limit. Coating the abraded amalgam discs with saliva reduced the mercury by 66–72% with the levels recorded being significantly lower (p<0.001). The level of total mercury within the saliva was found to be highly variable. Little change was noted in the neuronal cultures treated with 1 μM mercuric chloride. However, the cultures exposed to high level (10 μM) mercuric chloride showed cells that became rounded and clumped together indicating pathological change.Conclusions. Amalgam placement appears to present minimal mercury exposure risk. To reduce the amount of mercury released into air, however, amalgam should be polished in a moist atmosphere with high volume aspiration. The neurotoxic effect of mercury appears to be related to concentration, as only in the cultures treated with 10 μM mercuric chloride showed striking qualitative and quantitative cellular changes. [Copyright &y& Elsevier]

Summary: Yeasts that are resistant to azole antifungal drugs are increasingly isolated from the mouths of cancer patients suffering from oral fungal infections. Tea tree oil is an agent possessing antimicrobial properties that may prove useful in the prevention and management of infections caused by these organisms. In this study, 301 yeasts isolated from the mouths of 199 patients suffering from advanced cancer were examined by an in vitro agar dilution assay for susceptibility to tea tree oil. All of the isolates tested were susceptible, including 41 that were known to be resistant to both fluconazole and itraconazole. Clinical studies of tea tree oil as an agent for the prevention and treatment of oral fungal infections in immunocompromised patients merit consideration. [Copyright &y& Elsevier]

: ObjectivesTo determine the minimal time to successful intercourse after taking sildenafil citrate for erectile dysfunction (ED).: MethodsMale patients with ED (mean age 60 years; mean ED duration 7.0 years) who were successfully treated with sildenafil (100 mg) for 2 months or longer were randomized to sildenafil (n = 115) or placebo (n = 113) for 4 weeks of double-blind treatment. Using a stopwatch, patients recorded the time needed to obtain an erection hard enough for sexual intercourse after taking the study drug at least 2 hours after eating.: ResultsWithin 14 and 20 minutes of sildenafil dosing, 35% and 51% of sildenafil-treated patients, respectively, versus 22% and 30% of placebo-treated patients, respectively, had an erection that led to successful intercourse (P <0.05 for both). The median time to erection leading to successful intercourse after sildenafil dosing was 36 minutes compared with 141 minutes for placebo.: ConclusionsIn this study, slightly more than one half of a population of prior sildenafil responders achieved an erection that led to successful sexual intercourse within 20 minutes of sildenafil administration, suggesting that the onset of action of sildenafil can be less than 30 minutes in men with ED. [Copyright &y& Elsevier]

A new device—the Portable In Situ Wind ERosion Lab (PI-SWERL)—for measuring the potential for wind erosion and dust emission from soil surfaces is described. The device uses an annular ring (inner diameter=39cm, outer diameter=51cm) that rotates 6cm above the soil test surface. Dust and sand are mobilized by the shear created by the rotating ring. Dust concentrations within the chamber that encloses the annular ring are measured by light scattering, used as a surrogate for particulate matter mass concentrations. While the PI-SWERL does not realistically simulate natural wind erosion processes that are often driven by saltation, measurements with the device provide a robust index of wind erosion/dust emission potential. Compared to traditional field wind tunnels used for the same purpose, the PI-SWERL offers significant economy in size, portability, and ease of use. [Copyright &y& Elsevier]

Abstract: Venus Express is the first European mission to the planet Venus. Its payload consists of seven instruments and will investigate the atmosphere, the plasma environment, and the surface of Venus from orbit. Science planning is a complex process that takes into account requests from all experiments and the operational constraints. The planning of the science operations is based on synergetic approach to provide good coverage of science themes derived from the main mission goals. Typical observations in a single orbit—so-called “science cases” are used to build the mission science activity plan. The nominal science mission (from June 4, 2006 till October 2, 2007) is divided in nine phases depending on observational conditions, occurrences of the solar and Earth occultation, and particular science goals. The observation timelines for each phase were developed in a coordinated way to optimize the payload activity, maximize the overall mission science return, and to fit into the available mission budgets. [Copyright &y& Elsevier]

Erectile dysfunction is a common condition in men with cardiovascular disease, probably as a result of shared factors that impair hemodynamic mechanisms in the penile and ischemic vasculature. Sildenafil citrate, an orally active, selective inhibitor of phosphodiesterase type 5 (PDE5), has demonstrated excellent efficacy and safety profiles in men with erectile dysfunction of various etiologies. Sildenafil administration is contraindicated in patients who are taking nitrates or nitric oxide donors. This retrospective subanalysis of data from double-blind, placebo-controlled studies assessed the efficacy (9 studies) and safety (11 studies) of sildenafil in patients with erectile dysfunction and ischemic heart disease who were not taking nitrates. Of 3,672 patients randomized to receive sildenafil (5-200 mg) or placebo for 4-24 weeks in 11 double-blind, placebo-controlled studies, 357 (10%) reported a history (past or present) of ischemic heart disease and were not taking nitrates. Efficacy was assessed using end-of-treatment responses to Question 3 (ability to achieve an erection) and Question 4 (ability to maintain an erection) of the International Index of Erectile Function (IIEF), scores for the 5 domains of male sexual function assessed by the IIEF (erectile function, orgasmic function, sexual desire, intercourse satisfaction, and overall satisfaction), and responses to a global efficacy question ("Did the treatment improve your erections?"). The responses to the 2 IIEF questions were graded on a scale of 1 (almost never or never) to 5 (almost always or always), with a score of 0 indicating no attempt at sexual intercourse. At the end of treatment, the mean scores for Question 3 and Question 4 of the IIEF for patients with erectile dysfunction and ischemic heart disease were significantly higher for the sildenafil group than for the placebo group (p <0.0001). Mean end-of-treatment scores for the IIEF domains also demonstrated significant increases for sildenafil-treated patients compared with those receiving placebo (p <0.05). At the end of treatment, improved erections were reported by 70% of patients who received sildenafil and by 20% of those in the placebo group p <0.0001). For the sildenafil group, the incidences of the most common adverse events (headache 25%, flushing 14%, and dyspepsia 12%) for patients with ischemic heart disease were similar to those in patients without this concomitant illness (21%, 15%, and 10%, respectively). Moreover, the overall incidence of cardiovascular adverse events other than flushing was comparable in patients with and without ischemic heart disease for both treatment groups. Since there is a degree of cardiac risk associated with sexual activity, clinicians should consider the patient's cardiovascular status before initiating any treatment for erectile dysfunction. Physicians should be aware that patients with underlying cardiovascular disease could be adversely affected by the vasodilator effects of sildenafil, especially in combination with sexual activity. The results of the present subanalysis indicate that oral sildenafil significantly improves erectile function and is well tolerated in patients with erectile dysfunction and ischemic heart disease who are not taking nitrate therapy. [ABSTRACT FROM AUTHOR]