Structural and functional properties of rat liver mitochondria in hexachlorobenzene induced experimental porphyria

A possible link between changes in iron and porphyrin content in liver mitochondria, from rats treated with either hexachlorobenzene, iron, or hexachlorobenzene plus iron, as a function of treatment time and their structural-functional properties, has been investigated. Normal oxidative phosphorylation in mitochondria from rats treated with iron has been shown. By contrast a significant and constant uncoupling of the phosphorylative process, fully reversed by albumin, in mitochondria from rats treated with hexachlorobenzene and hexachlorobenzene plus iron has been presented. A possible involvement of pentachlorophenol in causing these abnormalities has been proposed.     

Inferring Cetacean Population Densities from the Absolute Dynamic Topography of the Ocean in a Hierarchical Bayesian Framework

We inferred the population densities of blue whales (Balaenoptera musculus) and short-beaked common dolphins (Delphinus delphis) in the Northeast Pacific Ocean as functions of the water-column’s physical structure by implementing hierarchical models in a Bayesian framework. This approach allowed us to propagate the uncertainty of the field observations into the inference of species-habitat relationships and to generate spatially explicit population density predictions with reduced effects of sampling heterogeneity. Our hypothesis was that the large-scale spatial distributions of these two cetacean species respond primarily to ecological processes resulting from shoaling and outcropping of the pycnocline in regions of wind-forced upwelling and eddy-like circulation. Physically, these processes affect the thermodynamic balance of the water column, decreasing its volume and thus the height of the absolute dynamic topography (ADT). Biologically, they lead to elevated primary productivity and persistent aggregation of low-trophic-level prey. Unlike other remotely sensed variables, ADT provides information about the structure of the entire water column and it is also routinely measured at high spatial-temporal resolution by satellite altimeters with uniform global coverage. Our models provide spatially explicit population density predictions for both species, even in areas where the pycnocline shoals but does not outcrop (e.g. the Costa Rica Dome and the North Equatorial Countercurrent thermocline ridge). Interannual variations in distribution during El Niño anomalies suggest that the population density of both species decreases dramatically in the Equatorial Cold Tongue and the Costa Rica Dome, and that their distributions retract to particular areas that remain productive, such as the more oceanic waters in the central California Current System, the northern Gulf of California, the North Equatorial Countercurrent thermocline ridge, and the more southern portion of the Humboldt Current System. We posit that such reductions in available foraging habitats during climatic disturbances could incur high energetic costs on these populations, ultimately affecting individual fitness and survival.     

LUMOS - A Sensitive and Reliable Optode System for Measuring Dissolved Oxygen in the Nanomolar Range

Most commercially available optical oxygen sensors target the measuring range of 300 to 2 μmol L^-1. However these are not suitable for investigating the nanomolar range which is relevant for many important environmental situations. We therefore developed a miniaturized phase fluorimeter based measurement system called the LUMOS (Luminescence Measuring Oxygen Sensor). It consists of a readout device and specialized “sensing chemistry” that relies on commercially available components. The sensor material is based on palladium(II)-5,10,15,20-tetrakis-(2,3,4,5,6-pentafluorphenyl)-porphyrin embedded in a Hyflon AD 60 polymer matrix and has a K_SV of 6.25 x 10^-3 ppmv^-1. The applicable measurement range is from 1000 nM down to a detection limit of 0.5 nM. A second sensor material based on the platinum(II) analogue of the porphyrin is spectrally compatible with the readout device and has a measurement range of 20 μM down to 10 nM. The LUMOS device is a dedicated system optimized for a high signal to noise ratio, but in principle any phase flourimeter can be adapted to act as a readout device for the highly sensitive and robust sensing chemistry. Vise versa, the LUMOS fluorimeter can be used for read out of less sensitive optical oxygen sensors based on the same or similar indicator dyes, for example for monitoring oxygen at physiological conditions. The presented sensor system exhibits lower noise, higher resolution and higher sensitivity than the electrochemical STOX sensor previously used to measure nanomolar oxygen concentrations. Oxygen contamination in common sample containers has been investigated and microbial or enzymatic oxygen consumption at nanomolar concentrations is presented.     

New enantiornithine bird (Aves, Ornithothoraces) from the Late Cretaceous of NW Argentina

A new enantiornithine bird, Intiornis inexpectatus gen. et sp. nov, is described here. It is based on a partial hind limb found in beds of the Upper Cretaceous Las Curtiembres Formation (Campanian), North-West Argentina. The new taxon is referred to the family Avisauridae on the basis of its cranially convex third metatarsal. Several features suggest close relationships between Intiornis and the avisaurid Soroavisaurus, from the Lecho Formation (Maastrichtian; North-West Argentina). Intiornis was the size of a sparrow, thus representing the smallest Enantiornithes known from South America. The new species shows adaptations for a perching mode of life. Moreover, the hypothesis suggesting that the flying pterosaur reptiles decrease in taxonomic diversity due to competitive interaction with birds is discussed. The new species shows adaptations for a perching mode of life. Moreover, the hypothesis suggesting that the flying pterosaur reptiles decrease in taxonomic diversity due to competitive interaction with birds is discussed.     

Effects of thermal water inhalation in chronic upper respiratory tract infections in elderly and young patients

Background

Chronic upper respiratory tract infections (cURTI) are very frequent illnesses which occur at any age of life. In elderly, cURTI are complicated by immunosenescence, with involvement of lung immune responsiveness.

Results

In the present study, 51 elderly (age range: 66–86) and 51 young (age range 24–58) cURTI patients underwent a single cycle (two weeks) of inhalatory therapy with salt-bromide-iodine thermal water in the thermal station “Margherita di Savoia” (Margherita di Savoia, BAT, Italy). Peripheral blood serum cytokines and clinical assessment were performed before therapy (T0) and after six months (T1) and 12 months (T2) from inhalatory treatment. In both elderly and young patients, at baseline an increased release of T helper (h)1-related cytokines [interleukin (IL)-2 and interferon-γ] and of Th2-related cytokine (IL-4) was documented. Inhalatory treatment reduced the excessive secretion of all the above-cited cytokines. IL-10 values were above normality at all times considered in both groups of patients. In addition, an increase in IL-17 and IL-21 serum levels following therapy was observed in both groups of patients. Pro-inflammatory cytokine (IL-1β, IL-6, IL-8 and tumor necrosis factor-α) baseline values were lower than normal values at T0 in both elderly and young cURTI patients. Their levels increased following inhalatory treatment.Clinically, at T2 a dramatic reduction of frequency of upper respiratory tract infections was recorded in both groups of patients.

Conclusion

Thermal water inhalation is able to modulate systemic immune response in elderly and young cURTI patients, thus reducing excessive production of Th1 and Th2-related cytokines, on the one hand. On the other hand, increased levels of IL-21 (an inducer of Th17 cells) and of IL-17 may be interpreted as a protective mechanism, which likely leads to neutrophil recruitment in cURTI patients. Also restoration of pro-inflammatory cytokine release following inhalatory therapy may result in microbe eradication. Quite importantly, the maintenance of high levels of IL-10 during the follow-up would suggest a consistent regulatory role of this cytokine in attenuating the pro-inflammatory arm of the immune response.

     

Urate oxidase of Chlamydomonas reinhardii

Urate oxidase (EC 1.7.3.3) of Chlamydomonas reinhardii cells grown on purines and purine derivatives has been partially characterized. Crude enzyme preparations have a pH optimum of 9.0, require O₂ for activity, have an apparent K_m of 12 μ M for urate, and are inhibited by high concentrations of this substrate. Enzyme activity was particularly sensitive to metal ion chelating agents like cyanide, cupferron, diethyldithiocarbamate and o -phenanthroline, and to structural analogues of urate like hypoxanthine and xanthine. Chlamydomonas cells grow phototrophically on adenine, guanine, hypoxanthine, xanthine, urate, allantoin or allantoate as sole nitrogen source, indicating that in this alga the standard pathway of aerobic degradation of purines of higher plants, animals and many microorganisms operates. As deduced from experiments in vivo , urate oxidase from Chlamydomonas is repressed in the presence of ammonia or nitrate.     

Metabolic engineering of ketocarotenoids biosynthesis in the unicelullar microalga Chlamydomonas reinhardtii

Most higher plants and microalgae are not able to synthesize ketocarotenoids. In this study the unicellular chlorophyte Chlamydomonas reinhardtii has been genetically engineered with the beta-carotene ketolase cDNA from Haematococcus pluvialis, bkt1 (GeneBank accession no. X86782), involved in the synthesis of astaxanthin, to obtain a transgenic microalga able to synthesize ketocarotenoids. The expression of bkt1 was driven by the Chlamydomonas constitutive promoter of the rubisco small subunit (RbcS2) and the resulting protein was directed to the chloroplast by the Chlamydomonas transit peptide sequences of Rubisco small subunit (RbcS2) or Ferredoxin (Fd). In all transformants containing the bkt1 gene fused to the RbcS2 or the Fd transit peptides a new pigment with the typical ketocarotenoid spectrum was detected. Surprisingly this ketocarotenoid was not astaxanthin nor canthaxanthin. The ketocarotenoid was identified on the basis of its mass spectrum as 3,3'-dihydroxy-beta,varepsilon-carotene-4-one (4-keto-lutein) or its isomer ketozeaxanthin.     

Long-term study on symptomless human metapneumovirus infection in hematopoietic stem cell transplant recipients

From October 2004 through October 2006 a study was performed to evaluate the prevalence of human Metapneumovirus (hMPV) infection in adult hematopoietic stem cell transplant (HSCT) recipients. Sequential nasopharyngeal aspirates (NPA) were collected independently from respiratory symptoms and evaluated for hMPV-RNA by polymerase chain reaction (PCR) and sequence analysis. Results indicate epidemiological and molecular differences between the 2004-2005 and 2005-2006 periods and that hMPV seems not to symptomatically affect HSCT patients or cause late respiratory sequelae. In addition, data collected suggest a hospital origin of hMPV infection in most HSCT patients during the 2004-2005 period.