The Pharmacology and Therapeutic Utility of Sodium Hydroselenide

Metabolically active gasotransmitters (nitric oxide, carbon monoxide and hydrogen sulfide) are important signalling molecules that show therapeutic utility in oxidative pathologies. The reduced form of selenium, hydrogen selenide (HSe⁻/H₂Se), shares some characteristics with these molecules. The simple selenide salt, sodium hydroselenide (NaHSe) showed significant metabolic activity, dose-dependently decreasing ex vivo O₂ consumption (rat soleus muscle, liver) and transiently inhibiting mitochondrial cytochrome C oxidase (liver, heart). Pharmacological manipulation of selenoprotein expression in HepG2 human hepatocytes revealed that the oxidation status of selenium impacts on protein expression; reduced selenide (NaHSe) increased, whereas (oxidized) sodium selenite decreased the abundance of two ubiquitous selenoproteins. An inhibitor of endogenous sulfide production (DL-propargylglycine; PAG) also reduced selenoprotein expression; this was reversed by exogenous NaHSe, but not sodium hydrosulfide (NaHS). NaHSe also conferred cytoprotection against an oxidative challenge (H₂O₂), and this was associated with an increase in mitochondrial membrane potential. Anesthetized Wistar rats receiving intravenous NaHSe exhibited significant bradycardia, metabolic acidosis and hyperlactataemia. In summary, NaHSe modulates metabolism by inhibition of cytochrome C oxidase. Modification of selenoprotein expression revealed the importance of oxidation status of selenium therapies, with implications for current clinical practice. The utility of NaHSe as a research tool and putative therapeutic is discussed.     

The effect of early ambulation on hematoma formation and vascular complications following 7 French diagnostic cardiac catheterization

OBJECTIVE: To assess the feasibility and safety of early ambulation 3 to 4 h after diagnostic 7 French cardiac catheterization. DESIGN: Randomized, single-blind assignment to one of 3, 4 or 6 h ambulation postcardiac catheterization groups. SETTING: Tertiary care community hospital in an urban region. PATIENTS: Eight hundred and seventy-four consecutive inpatients and out-patients presenting for routine diagnostic cardiac catheterization. INTERVENTION: Hematoma formation and other vascular complications recorded at the time of discharge and 24 h later. MAIN RESULTS: No significant difference in hematoma formation rates was noted among patients mobilized at 3 h (3.6%), 4 h (4.8%) or 6 h (3.2%). Late hematoma formation occurred in 2.3% of patients. Other vascular complications were very rare. Reported rates of hematoma formation varied significantly (P < 0.05) among physicians, ranging from 0.9% to 8.0%. CONCLUSIONS: Early ambulation of patients 3 to 4 h after routine diagnostic 7 French cardiac catheterization is both safe and feasible. These findings could result in more efficient recovery bed utilization, reduced nursing costs and improved patient compliance with bed rest.     

Performance Comparison of Various Multicode Modulation Schemes for High-Rate Wireless Data Transmission

Multicode modulation is amodulation technique which can allowtransmission of high-speed data over wireless links.The basic idea behind this method is that high-rateinformation bits are converted to parallel low-ratebit streams in order to make the transmitted signal less sensitive to time delayspread.Each low-rate bits is then modulated by a code, whichis a combination of orthogonal codes and spreadingsequences, on a single carrier.In this paper, we investigate the use of variouscombination oforthogonal codes and signature sequences in multicodemodulation and propose a low-complexity receiver structure whichusesFast Walsh Transform or Fast Fourier Transform.To further improve system performance,we consider the use of antenna diversity,interleaving,and convolutional coding.Sample numerical results which illustrate thepotentialof multicode modulationover multipath Rayleigh fading links will also bepresented.