Differences in skeletal and muscle mass with aging in black and white women

Previous cross-sectional studies using delayed gamma neutron activation analysis and whole body counting suggested that the relationship of total body calcium (TBCa) to total body potassium (TBK) (muscle mass, body cell mass) remained constant with age. This led to the hypothesis that the muscle mass and skeletal mass compartments are integrated in their response to aging. It had also been hypothesized that loss of skeletal and muscle mass was similar between races. In the current study, delayed gamma neutron activation analysis and whole body counting were performed on 90 black and 143 white women 20-69 yr of age. Black women had higher TBCa and TBK values than white women, even when the data were adjusted for age, height, and weight. TBCa was correlated with height and TBK with weight. The estimated decline of skeletal mass (TBCa) from 20 to 70 yr was 18% in black women and 19% in white women. However, the lifetime decline of TBK was only 8% for black women, compared with 22% for white women. Black women may lose TBK more slowly than TBCa with aging, compared with white women. In particular, correlation of TBCa and age was similar for blacks and whites (r = -0.44 and r = -0.54, respectively). However, for TBK these correlations were r = -0.14 and r = -0.42. These data confirm a higher musculoskeletal mass in black women and suggest that the loss of muscle mass with age may be lower in black than in white women. These ethnic differences do not support the hypothesis of an integrated musculoskeletal system, so that these two components should be considered separately. A prospective study is needed to confirm these findings.     

Bioremediation of oil polluted aquatic systems and soils with novel preparation `Rhoder'

This paper summarises the experience accumulated duringthe field application of biopreparation `Rhoder' (solely or in a combinationwith preliminary mechanical collection of free oil) for remediation of oil polluted aquatic systems and soils in the Moscow region and Western Siberia during 1994–1999.It was demonstrated that `Rhoder' had a very high efficiency (>99%) for bioremediation of the open aquatic surfaces (100 m² bay of the River Chernaya, two 5,000 m² lakes in Vyngayakha) at initial level of oil pollution of 0.4–19.1 g/l. During remediation of the wetland (2,000 m²) in Urai (initial level of oil pollution of 10.5 g/l), a preliminary mechanical collection of oil was applied (75% removal) followed by a triple treatment with `Rhoder'. It resulted in an overall treatment efficiency of 94%. Relatively inferior results of bioremediation of the 10,000 m² wetland in Vyngayakha (65% removal) and the 1,000 m² marshy peat soil in Nizhnevartovsk (19% removal) can be attributed to the very high initial level of oil pollution (24.3 g/l and >750 g/g dry matter, respectively) aggravated by the fact that it was impossible to apply a preliminary mechanical collection of oil on these sites. A possible strategy for remediation of such heavily polluted sitesis discussed.     

Dihydro-resveratrol—A potent dietary polyphenol

Dihydro-resveratrol (dihydro-R), a prominent polyphenol component of red wine, has a profound proliferative effect on hormone-sensitive tumor cell lines such as breast cancer cell line MCF7. We found a significant increase in MCF7 tumor cells growth rates in the presence of picomolar concentrations of this compound. The proliferative effect of dihydro-R was not observed in cell lines that do not express hormone receptors (MDA-MB-231, BT-474, and К-562).     

Marine bacterioplankton can increase evaporation and gas transfer by metabolizing insoluble surfactants from the air–seawater interface

Hydrophobic surfactants at the air–sea interface can retard evaporative and gaseous exchange between the atmosphere and the ocean. While numerous studies have examined the metabolic role of bacterioneuston at the air–sea interface, the interactions between hydrophobic surfactants and bacterioplankton are not well constrained. A novel experimental design was developed, using Vibrio natriegens and ³H-labelled hexadecanoic acid tracer, to determine how the bacterial metabolism of fatty acids affects evaporative fluxes. In abiotic systems, >92% of the added hexadecanoic acid remained at the air–water interface. In contrast, the presence of V. natriegens cells draws down insoluble hexadecanoic acid from the air–water interface as an exponential function of time. The exponents characterizing the removal of hexadecanoic acid from the interface co-vary with the concentration of V. natriegens cells in the underlying water, with the largest exponent corresponding to the highest cell abundance. Radiochemical budgets show that evaporative fluxes from the system are linearly proportional to the quantity of hexadecanoic acid at the interface. Thus, bacterioplankton could influence the rate of evaporation and gas transfer in the ocean through the metabolism of otherwise insoluble surfactants.     

Changes in distribution of an archaic moth, Micropterix calthella, in St Petersburg, Russia, between 1989 and 2005

Aim  This work aimed to assess changes in the number of suitable habitats and habitat occupancy by Micropterix calthella (L.) moths (Lepidoptera, Micropterigidae) in the city of St Petersburg between 1989 and 2005.
Location  The city of St Petersburg, Russia.
Methods  The study compares results of the survey conducted on 9–12 June 2005 with data collected in 1989 and is based on the assessment of the quality and occupancy of 103 habitats that were found potentially suitable for M. calthella in 1989. If habitats contained wet microsites with undisturbed litter and dense field layer vegetation with a high abundance of flowering Ranunculus sp., they were considered potentially suitable for M. calthella ; in these habitats, moths were searched for on flowers of Ranunculus – visually and/or by extensive sweep-netting.
Results  Both the number of habitats suitable for M. calthella and the number of habitats occupied by this species decreased since 1986 from 103 to 72 and from 58 to 34, respectively. The disappearance of habitats was primarily due to the building of residential blocks within the city (16 sites) and railway renovation (10 sites), while changes in habitat management, primarily in parks and recreation zones (five sites), were less important. The average distance from the city centre to the nearest population of M. calthella increased from 8.7 ± 1.5 to 12.9 ± 3.0 km (mean ± SE).
Main conclusion  The data for 2005 fit the prediction that M. calthella moths, which are unable to re-colonize potentially suitable habitats due to their low migratory ability, will disappear from the city. At the present rate of extinction, this process may take some 20–30 years to complete (or nearly complete).     

Inhibitors of the Candida albicans Major Facilitator Superfamily Transporter Mdr1p Responsible for Fluconazole Resistance

ObjectiveTo identify a novel class of inhibitors of fungal transporters involved in drug resistance.MethodsA series of structurally-related low molecular mass compounds was synthesized using combinatorial chemistry of a cyclobutene-dione (squarile) core. These compounds were screened for their inhibition of plasma membrane Major Facilitator Superfamily (MFS) and ATP-binding cassette (ABC) transporters responsible for efflux pump-mediated drug resistance in the fungal pathogen Candida albicans. Strains of Saccharomyces cerevisiae that specifically overexpress the MFS pump CaMdr1p or the ABC transporter CaCdr1p were used in primary screens and counterscreens, respectively, and to detect inhibition of glucose-dependent Nile Red efflux. Efflux pump inhibition, activity as pump substrates and antifungal activity against yeast and clinical isolates expressing efflux pumps were determined using agarose diffusion susceptibility assays and checkerboard liquid chemosensitization assays with fluconazole.ResultsThe screen identified five structurally-related compounds which inhibited CaMdr1p. Two compounds, A and B, specifically chemosensitized AD/CaMDR1 to FLC in a pH-dependent fashion and acted synergistically with FLC in checkerboard liquid MIC assays but compound B had limited solubility. Compound A chemosensitized to FLC the azole-resistant C. albicans strain FR2, which over-expresses CaMdr1p, inhibited Nile Red efflux mediated by CaMdr1p but not CaCdr1p and was not toxic to cultured human cells. A minor growth-inhibitory effect of B on AD/CaMDR1, but not on AD/CaCDR1 and AD/CaCDR2, indicated that compound B may be a substrate of these transporters. The related compound F was found to have antifungal activity against the three pump over-expressing strains used in the study.ConclusionsCompound A is a ‘first in class’ small molecule inhibitor of MFS efflux pump CaMdr1p.     

Forced Fusion in Multisensory Heading Estimation

It has been shown that the Central Nervous System (CNS) integrates visual and inertial information in heading estimation for congruent multisensory stimuli and stimuli with small discrepancies. Multisensory information should, however, only be integrated when the cues are redundant. Here, we investigated how the CNS constructs an estimate of heading for combinations of visual and inertial heading stimuli with a wide range of discrepancies. Participants were presented with 2s visual-only and inertial-only motion stimuli, and combinations thereof. Discrepancies between visual and inertial heading ranging between 0-90° were introduced for the combined stimuli. In the unisensory conditions, it was found that visual heading was generally biased towards the fore-aft axis, while inertial heading was biased away from the fore-aft axis. For multisensory stimuli, it was found that five out of nine participants integrated visual and inertial heading information regardless of the size of the discrepancy; for one participant, the data were best described by a model that explicitly performs causal inference. For the remaining three participants the evidence could not readily distinguish between these models. The finding that multisensory information is integrated is in line with earlier findings, but the finding that even large discrepancies are generally disregarded is surprising. Possibly, people are insensitive to discrepancies in visual-inertial heading angle because such discrepancies are only encountered in artificial environments, making a neural mechanism to account for them otiose. An alternative explanation is that detection of a discrepancy may depend on stimulus duration, where sensitivity to detect discrepancies differs between people.