Walking, Sedentary Time and Health-Related Quality Life Among Kidney Transplant Recipients: An Exploratory Study.

OBJECTIVES: The primary objectives of this study were to: 1) establish walking and physical activity prevalence and sedentary time estimates; and 2) determine associations of health-related quality of life (HRQoL) with objectively assessed walking, self-reported physical activity, and sedentary time among kidney transplant recipients. METHODS: Using a cross-sectional design, kidney transplant recipients received a survey package containing measures of sedentary time, moderate-to-vigorous physical activity, and HRQoL, and a step pedometer. RESULTS: Thirty-two participants returned a completed survey, for a response rate of 82% (32 of 39 interested participants). The average steps per day were 9752 steps (SD = 3685) and 59% achieved public health guidelines of at least 150 minutes of moderate-to-vigorous physical activity per week. Total sedentary time during the week was 11.6 h/d whereas total sedentary time during the weekend was 8.9 h/d. Compared to those not achieving at least 10,000 steps/d, respondents who were achieving at least 10,000 steps/d had a significantly higher physical component score for HRQoL (Mdiff = 7.8, P = .018). Similar patterns emerged for meeting physical activity guidelines and sedentary time. CONCLUSION: For kidney transplant recipients, greater participation in walking, overall physical activity, and lower engagement in sedentary activity, was associated with better HRQoL.

Use of response biomarkers in milk for assessing exposure to environmental contaminants: the case for dioxin-like compounds.

Screening for environmental contaminants in milk is generally conducted by chemical analysis, yet such an approach may be time-consuming and expensive, and is not indicative of the physiological consequences of such exposure. The focus of this review is to summarize those constituents of milk that may be altered by maternal exposure to one of the most biologically active environmental pollutants, 2,3,7,8-tetrachlorodibenzo-p-dioxin, and to develop the case for their use as biomarkers of response. Several chemical and/or cellular components of milk are potentially useful as biomarkers, and may be developed as convenient, biologically relevant indicators of maternal exposure to dioxin-like compounds.

Pathophysiology and implications for treatment of acute respiratory distress syndrome.

Acute respiratory distress syndrome is a complex group of signs and symptoms caused by direct or indirect lung injury. In spite of decades of research, it is still associated with a high mortality rate. Pathogenesis of this disease is related to alveolar endothelial and epithelial cell injury and associated release and sequestration of inflammatory mediators and cells, including cytokines and neutrophils, respectively. Pharmacologic interventions have been largely unsuccessful, and ventilation strategies to support oxygenation while limiting ventilator associated lung injury have not demonstrated any significant reductions in the mortality rate. However, novel therapies are in development, based on the knowledge of the pathologic processes of acute respiratory distress syndrome. In this article an overview of the disease process and mediator involvement is presented, followed by a review of pharmacologic and ventilation treatments currently in use or under study.

The Effects of Eicosanoid Biosynthesis Inhibitors On Prophenoloxidase Activation, Phagocytosis and Cell Spreading in Galleria mellonella.

The invertebrate immune system produces melanotic nodules in response to bacterial infections and this has previously been shown to be mediated by eicosanoids. Nodulation occurs in two phases: the first involves hemocyte degranulation and activation of the prophenoloxidase cascade; the second involves formation of a cellular capsule by attachment and spreading of hemocytes. We demonstrate that inhibitors of eicosanoid biosynthesis affect both of these phases of nodulation in Galleria mellonella. The phospholipase A(2) inhibitor, dexamethasone, as well as the cyclooxygenase inhibitor, indomethacin, significantly inhibit phagocytosis in vitro and prophenoloxidase activation in vivo. The inhibitory effects of dexamethasone were abolished by the addition of exogenous arachidonic acid. Furthermore, 5,8,11,14- eicosatetraynoic acid, dexamethasone and indomethacin inhibit hemocyte spreading in vitro. The findings support the idea that eicosanoid derivatives mediate both phases of the nodulation response and are consistent with previous studies which attribute roles for eicosanoids in other species as modulators of cell activity.

Imaging electrophoretic gels with a scanning beam laser macroscope.

A scanning beam laser macroscope has been developed which scans an area of 7.5 x 7.5 cm in 5 s. This new imaging system is examined as a potential tool for scanning electrophoretic gels. A specially-designed telecentric, f* theta laser scan lens is used in the instrument to achieve a linear scan and a flat focal plane. The laser scan lens focuses the incoming beam from a laser to a 10 microns spot inside the gel. A raster scan is performed across the gel and the signal is detected with a photomultiplier, forming a 512 x 512 digital image stored as a computer file. Silver-stained protein polyacrylamide gels have been imaged in transmission and double-transmission, while DNA agarose gels (stained with ethidium bromide) have been imaged in fluorescence with better than 25 pg sensitivity. The macroscope has the advantage that it is not tied to the electrophoresis system as are end-of-line scanners, and the scan is rapid, so that several gels can be scanned in a very short time.

In vitro exposure of a novel polyesterurethane graft to enzymes: a study of the biostability of the Vascugraft arterial prosthesis.

The biostability of the Vascugraft arterial prosthesis, a porous synthetic graft made by a novel spinning process from a unique poly(ester urethane) polymer, has been studied by means of an in vitro enzyme incubation technique. Samples of the Vascugraft were exposed to buffered solutions of collagenase and pancreatin, as well as the buffer solutions alone, for periods of up to 100 days at 37 +/- 1 degrees C. On removal and after cleaning, a number of different analytic methods, including X-ray photoelectron spectroscopy for chemical analysis (ESCA), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), differential scanning calorimetry (DSC), size exclusion chromatography (SEC), scanning electron microscopy (SEM), interference microscopy, moisture content and contact angle measurements, were used to examine the changes in chemical structure and surface morphology of the samples. During incubation in both enzymes the molecular weight of the polyurethane appeared to decrease in the presence of enzyme but increase in the presence of buffer. Further microphase separation in the polyurethane material developed during incubation in buffer solutions. Such changes in microstructure were associated with increased surface hydrophilicity, increased moisture content and a significant improvement in the extent of order and preferred orientation of the hard segment domains within the fibres. In the sampling depth of about 5 nm, both enzymes decreased the carbonate group content at the surface of the prosthesis to as little as 40% of their original values. The results from ATR-FTIR and DSC demonstrated that this phenomenon was limited primarily to the soft segment phase. While the Vascugraft prosthesis did exhibit some limited chemical modifications on exposure to concentrated enzyme solutions, nevertheless such changes were confined to the surface layer of the polyurethane microfibres. The importance and significance of those results will be more adequately determined by in vivo investigation.

Localization of vasa protein to the Drosophila pole plasm is independent of its RNA-binding and helicase activities.

The Drosophila gene vasa encodes a DEAD-box protein, which is localized during early oogenesis to the perinuclear region of the nurse cells and later to the pole plasm at the posterior end of the oocyte. Posterior localization of vasa protein depends upon the functions of four genes: capu, spir, osk and stau. We have found that localization of vasa to the perinuclear nuage is abolished in most vas alleles, but is unaffected by mutations in four genes required upstream for its pole plasm localization. Thus localization of vasa to the nuage particles is independent of the pole plasm assembly pathway. Furthermore, electron-dense nuage particles are less abundant in the cytoplasm of nurse cells from vas mutants that fail to exhibit perinuclear localization, suggesting that the formation of the nuage depends upon vas function. Eight of nine vas point mutations cause codon substitutions in a region conserved among DEAD-box genes. The proteins from two mutant alleles that retain the capacity to localize to the posterior pole of the oocyte, vasO14 and vasO11, are both severely reduced in RNA-binding and -unwinding activity as compared to the wild-type protein on a variety of RNA substrates including in vitro synthesized pole plasm RNAs. Initial recruitment of vasa to the pole plasm must consequently depend upon protein-protein interactions but, once localized, vasa must bind to RNA to mediate germ cell formation.

Ionic basis of bioelectric currents during oogenesis in an insect.

Transmembrane bioelectric currents around insect ovaries are well documented but as yet poorly understood. In the present study we describe the ionic basis of such currents around the telotrophic ovariole of Rhodnius prolixus using a two-dimensional vibrating probe and ion-substituted media and inhibitors. Current efflux from the base and apex of the terminal follicle is carried by electrogenic Na+ transport, and the return circuit over the middle of the terminal follicle is the result of Na+ influx/Cl- efflux. We further show that a transient inward current at the apex of midvitellogenic terminal follicles is carried by Ca2+ ions and broadly correlates both spatially and temporally with trophic cord closure. A distinct current loop over the tropharium arises at the base via electrogenic Na+ efflux and returns over the middle and apical regions of the tropharium via Na+ and Ca2+ influx. These findings serve as a basis for the further dissection of the physiological relevance of transcellular ion currents around developing insect ovarian follicles.

Spatial and temporal transcellular current patterns during oogenesis.

We have used the two-dimensional vibrating probe to examine spatial and temporal patterns in the transcellular current flow around telotrophic ovarioles of the insect Rhodnius prolixus. We demonstrate a dynamic pattern of currents which correlates with various stages of vitellogenesis. Asymmetries exist in the radial current pattern around intact ovarioles, particularly around the terminal follicle, and may correlate with early developmental axes. The extra-cellular current pattern is largely reflected by a similar, though weaker pattern of currents over the germ cell membranes, indicating that both germ cell and somatic cell membranes are involved in current generation. Current enters previtellogenic oocytes and leaves oocytes entering vitellogenesis. We speculate that current reversal and loss of trophic cord contact may represent an electrophysiological feedback control mechanism during oogenesis.

Pattern and Composition of Ionic Currents Around Ovarioles of the Hemipteran, Rhodnius prolixus (Stahl).

Two-dimensional vibrating probe analysis of extracellular currents around Rhodnius prolixus ovarioles correlated with an earlier one-dimensional analysis but revealed asymmetrical circumferential current patterns and large tangential currents. Na+, K+, and Ca+2 have been tentatively identified as the major ions involved in these currents, with Na+ being the major ion involved in current efflux.