A single point mutation in the VP7 major core protein of bluetongue virus prevents the formation of core-like particles.

To understand the assembly process of bluetongue virus (BTV), we have established a functional assay which allows us to produce and manipulate BTV core-like particles (CLPs) composed of the viral VP7 and VP3 proteins. A cDNA clone encoding the 349-amino-acid VP7 protein has been manipulated to generate deletion, extension, and site-specific mutants. Each mutant was coexpressed with the BTV VP3 protein to generate CLPs. Deletion and extension mutants involving the VP7 carboxy terminus prevented CLP formation, while an extension mutant involving an 11-amino-acid rabies virus sequence added to the amino terminus of VP7 allowed CLP formation. Substitution of either of two cysteine residues of VP7 (Cys-15 or Cys-65) by serine also did not prevent CLP formation; however, substitution of the single lysine residue of VP7 (Lys-255) by leucine abrogated CLP formation, indicating a critical role for this lysine.     

Desulphuring of natural gas and petroleum oil by autotrophic Thiobacillus ferrooxidans

Hydrogen sulphide is a common toxic contaminant in natural gas and oil. In this study, the strictly autotrophic bacterium Thiobacillus ferrooxidans , which oxidizes reduced sulphur compounds, was used to desulphur petroleum oil and gas. The reaction was carried out in a closed vessel containing substrate mixed with a bacterial suspension. The significance of the hydrogen sulphide oxidizing activity of T. ferrooxidans is discussed.     

Ibuprofen, a unique anti-inflammatory compound with antifungal activity against dermatophytes

Ibuprofen showed significant antifungal activity in vitro against dermatophytes at pH 5 (MIC: 5–40 μg ml^-1). In this respect it is comparatively more efficient than two well known and medically used antifungal compounds, benzoic and salicylic acids. This compound with anti-inflammatory activity which is not found in any other conventional antifungal organic acids, may have clinical prospects.     

Reversal of sexual impotence in male patients with chronic obstructive pulmonary disease and hypoxemia with long term oxygen therapy

Erectile impotence is commonly encountered in male patients with respiratory failure and hypoxia. In this study, 42% of the patients experienced reversal of sexual impotence during long term oxygen therapy (LTOT). We examine the association between sexual impotence, gonadal axis hormones, hypoxia, and oxygen therapy. Nineteen sexually impotent male patients eligible for LTOT (pO₂ < 7.3 kPa during stable disease) and with sexual impotence received oxygen therapy for 1 month (n = 12) or 24 h (n = 7). pO₂, LH, FSH, testosterone, and SHBG (sex hormone binding globulin) were monitored. Five of 12 patients receiving oxygen for 1 month regained sexual potency. The responders showed a significant increase in arterial pO₂ and serum testosterone, and a decline in SHBG compared to non-responders. None of the patients receiving oxygen for 24 h experienced reversal of sexual impotence, despite a significant increase in pO₂. In these patients, serum testosterone did not increase significantly. Reversal of sexual impotence may be achieved in some patients with respiratory failure. The oxygen therapy must, however be administered for an adequate length of time.     

Metabolic interdependence of obligate intracellular bacteria and their insect hosts.

Mutualistic associations of obligate intracellular bacteria and insects have attracted much interest in the past few years due to the evolutionary consequences for their genome structure. However, much less attention has been paid to the metabolic ramifications for these endosymbiotic microorganisms, which have to compete with but also to adapt to another metabolism--that of the host cell. This review attempts to provide insights into the complex physiological interactions and the evolution of metabolic pathways of several mutualistic bacteria of aphids, ants, and tsetse flies and their insect hosts.     

THE VISIBILITY AND INVISIBILITY OF PRODUCTION AMONG SENEGALESE CRAFTSMEN

This article examines three social contexts of the production and exchange of craft objects in Senegal. In each context, the extent to which the production of craft items is visible or invisible varies, and these variations in turn affect the ways in which value is construed. These examples are understood as different 'regimes of value' (Appadurai), in whose constitution the production of craft objects, whether this is visible or invisible, plays a crucial role. The argument is that the concept of 'regime of value' needs to address more than simply the 'flow' of commodities, and must have regard for the organization of the relations between production, distribution, and consumption of craft objects. The article also frames these West African examples within a broader argument about the importance of the concept of production in order to redress the over-reliance of contemporary social theories on notions of consumption.     

Evaluation of anti-inflammatory activity of Vernonia cinerea Less. extract in rats.

The methanol extract of the whole plant of Vernonia cinerea Less. was evaluated for its anti-inflammatory activity in acute (carrageenin, histamine and serotonin induced rat paw edema) and a chronic model (cotton pouch induced granuloma). The methanol extract (250 and 500 mg/kg(-1) p.o.) exhibited significant activity (p < 0.001) against all phlogistic agents used in a dose dependant manner. In the chronic model (cotton pouch granuloma method) the methanol extract exhibited significant anti-inflammatory activity. All these effects were compared with standard drug phenylbutazone (100 mg/kg(-1) p.o.).     

A biphasic model of limb venous compliance: a comparison with linear and exponential models.

Compliance is not linear within the physiological range of pressures, and linear modeling may not describe venous physiology adequately. Forearm and calf venous compliance were assessed in nine subjects. Venous compliance was modeled by using a biphasic model with high- and low-pressure linear phases separated by a breakpoint. This model was compared with a linear model and several exponential models. The biphasic, linear, and two-parameter exponential models best represented the data. The mean coefficient of determination for the biphasic model was greater than for the linear and exponential models in the calf (biphasic 0.94 +/- 0.04, exponential 0.81 +/- 0.16, P = not significant; and linear 0.54 +/- 0.05, P < 0.05) and forearm (biphasic 0.83 +/- 0.17, exponential 0.79 +/- 0.15, P = not significant; and linear 0.51 +/- 0.06, P < 0.05). The breakpoint pressure in the biphasic model was higher in the calf than the forearm, 34.4 +/- 3.9 vs. 29.1 +/- 4.5 mmHg, P < 0.05. A biphasic model can describe limb venous compliance and delineate differences in venous physiology at high and low pressures. The steep low-pressure phase of the compliance curve extends to higher pressures in the calf than in the forearm, thereby enlarging the range of pressures over which hemodynamic regulation by the calf venous circulation occurs.